Most of us have taken, or at least interacted with, medicine at some point or another in our lives. This can range from more “simple” over-the-counter drugs to more complex medicines specifically designed for exact illnesses. Considering the Covid-19 era we are going through and as search for a vaccine is at the highest possible speed, it is important to have at least a general idea on how medicines are developed for our use. This article aims to explore how a complicated mix of chemical compounds in a laboratory end up as pills on a shelf in your local pharmacy. We will also explore a brief history of pharmacology, where drugs get their names, how drugs come into fruition, the various affects that drugs can have on our bodies, along with the discrepancies that exist between them in regard to when, how, and why they should be taken.

Pharmacology is the study of the interactions that occur between a living organism and the chemicals that affect normal or abnormal biochemical functions. It includes the study of how a drugs can affect our biological systems, such as individual organs or an entire part of the body, and how the body overall responds to the drug. The discipline encompasses the sources, chemical properties, biological effects and, therapeutic uses of drugs. Substances with medicinal properties are considered pharmaceuticals, whereas drugs given for therapeutic purposes are usually called medications. Drug therapy, which is also called pharmacotherapy, is the use of drugs to prevent, diagnose, and treat signs, symptoms, and disease processes. When prevention or cure is not a reasonable goal, relief of symptoms can greatly improve quality of life and the ability to function properly on a day-to-day basis. Developing an understanding of this craft can allow us to better appreciate how molecules interact to form the drugs and medicines that can change our lives, and perhaps even allow us to contemplate their complex creation and existence.

In its most simplistic definition, a medication is a substance that is ingested or placed onto the body in order to cure a disease or condition (antibiotics are given to cure an infection), treat a medical condition (anti-depressants are given to treat depression), relieve symptoms of an illness (pain relievers are given to reduce pain), given to prevent diseases (flu vaccine helps to prevent the person from complications of having the flu).

Source of drugs

Historically, drugs were mainly derived from plants, animals, and minerals. Morphine, insulin, and iron are all commonly used examples of their respective sources. Belief in the curative powers of plants and certain substances rested exclusively upon traditional knowledge. But empirical information was not subjected to critical examination. Until the end of the 19th century, medicines were made by natural organic or inorganic products including mostly dried or fresh plants and their parts. These compounds might contain substances that possess healing properties or reactions that exert a toxic effect. It is important to remember that many fruits, vegetables, and plants still possess great power despite not having a “modern” origin.

Most drugs used nowadays are synthetic chemical compounds manufactured in laboratories which are synthesized by altering the chemical structure of an existing drug. The first drug of a particular group of drugs are called prototypes. For example, morphine is the prototype of opioid analgesics, and penicillin is the prototype of antibacterial drugs. Drug classifications and prototypes are defined and most new drugs can be assigned to a group. We must be hopeful and continue to search far and wide for cures for all  diseases, whether they be organic or synthetic, since our world is full of an infinite amount of possibilities and discoveries.

Drug names

The systematic naming of pharmaceutical drugs is called “drug nomenclature.” Drugs primarily have three types of names: chemical names, generic names, and trade names. The chemical names are the scientific names that often sound complex and are based upon the molecular structure of a drug. During development, the company will apply for regulatory approval of the drug by the relevant national regulatory agency, such as the U.S. Food and Drug Administration (FDA), and will be granted a generic name for it. Generic names usually indicate, via their stems, what drug class the drug belongs to. For example, oseltamivir is an antiviral drug because its name ends in the -vir suffix.

After development, testing, and regulatory acceptance of a drug, the pharmaceutical company gives the drug a trade name, which is a standard term in the pharmaceutical industry for a brand name or trademark name. Many drugs have multiple trade names which can reflect separate marketing strategies in different countries, manufactured by different companies, or both.

Drug investigation

A new drug investigation is the beginning of the journey of a chemical compound to a drug that will be used in clinics. The testing process of a chemical compound begins with animal studies to determine potential beneficial uses and also potential toxic side effects of the candidate compound.  The results from these animal studies are reviewed, and if the results are satisfactory, the compound then undergoes clinical trials in humans that people can voluntarily sign up for. Most clinical trials use a randomized, controlled experimental design that involves selection of subjects according to established criteria, random assignment of subjects to experimental groups, and administration of the test drug to one group and a control substance to another group.

Patent protection

New drugs that are developed by pharmaceutical companies will be covered under patent protection. This means that only the pharmaceutical company that holds the patent is allowed to manufacture, market, and eventually profit from the drug. This is seen as a return on the company’s investment that it took to develop the drug, which may require years of work and millions of dollars, along with an incentive for developing other drugs. Other pharmaceutical companies cannot manufacture and market the drug during the patent period.

Usually, the drug patent is awarded for around twenty years in the United States, however the number of years varies across countries and drugs. Pharmaceutical companies apply for a patent long before the clinical trial period even begins. The effective patent period after the drug has finally received approval is often around seven to twelve years. After the patented period expires the drug can be manufactured and sold by other companies. The drug is referred to as a generic drug at this point, and they are required to be therapeutically equivalent and much less expensive than trade name drugs.

Pharmacoeconomics

Pharmacoeconomics involves all of the costs that are accrued due to drug therapy and experimentation including those related to purchasing supplies, dispensing the drug, storing it, administrative fees, laboratory and other tests that are used to monitor patient responses, and losses from expiration. The length of a patient’s illness or hospitalization is also considered. While the most important factor is the health of the patient the costs for treatment are increasingly being considered as a major factor when choosing medications, and research projects that compare costs have greatly increased in recent years. The goal is to make it easier for patients to choose the most cost-effective drugs that combine high quality treatment at an affordable price. For drugs or regimens of similar efficacy and toxicity, there is considerable pressure upon doctors and pharmacies to prescribe less costly drugs for shorter duration.

Prescription and non-prescription drugs

In many countries, consumers have two legal routes of access to therapeutic drugs. One route involves a prescription or order from a licensed health care provider, such as a physician, dentist, or nurse practitioner. The other route is by over-the-counter (OTC) purchase of drugs that do not require a prescription. Both of these routes are regulated by various drug laws that change from country to country. Acquiring and using prescription drugs for non-therapeutic purposes, by persons who are not authorized to have the drugs or for whom they are not prescribed, is illegal.

The rejection of drugs in modern society

Nowadays, there are some people who deny various kinds of treatments because of their religious beliefs. This category of people is only a minority, as the majority of religions advocate for people to be healthy and to take care of their health as much as they can. In almost all belief traditions, the human body is believed to be a trust, and in case of any disease, the most appropriate and fastest treatment methods should be used. Even substances that are not normally permitted are allowed by scholars to be used if the person’s safety is concerned. For believers, the most important goal in life is to worship God, and for this to be possible the body must be healthy.

One day, people asked Prophet Muhammad, peace be upon him:

“Should we make use of medical treatment?”

He replied: “Make use of medical treatment, for God has not made a disease without appointing a remedy for it, with the exception of one disease, namely old age.”

People are encouraged to seek out those remedies and to use them with skill and kindness. Let us also remember that Jesus, peace be upon him, too, was very active in his ministry of healing. He showed by God’s permission miracles like curing the blind and the deaf, and bringing the dead back to life. Thus, religions do not refuse treatment with any available methods, and they even strongly encourage treatment and prevention of diseases.

Religions are also well known to treat stress, which wreaks havoc on the mind and body. It is still not known exactly how stress harms our health, but researchers have found that chronic psychological stress is associated with body’s losing its ability to regulate the inflammatory response. It has been shown that the effects of psychological stress on the body’s ability to regulate inflammation can promote the development and progression of disease. We know that religions and beliefs give people hope and significantly decrease the stress.

Human beings are the most precious creation, and health is necessary for us to achieve the purpose of our existence. Using scientific medicine together with faith and religion can help people to protect their health. Being the science of drugs and by investigating new drug therapies, pharmacology helps us exactly with that.

History of Pharmacology

Claudius Galen (129–200 A.D.) was the first person who attempted to consider the theoretical background of pharmacology.

Ali al-Tabari (838 A.D.) Medieval Islamic physicians used natural substances such as Papaver somniferum Linnaeus, poppy, and Cannabis sativa Linnaeus, hemp as a source of medicinal drugs. Although poppy had medicinal benefits, Ali al-Tabari explained that the extract of poppy leaves was lethal, and the extracts and opium should be considered poisons (4).

Theophrastus von Hohenheim (1493–1541), also known as “Paracelsus”, began to question doctrines from antiquity. He prescribed chemically defined substances with such success that professional enemies had him prosecuted as a poisoner. Against such accusations, he defended himself with the thesis that has become an axiom of pharmacology:

“If you want to explain any poison properly, what then isn‘t a poison? All things are poison, nothing is without poison; the dose alone causes a thing not to be poison.”

Johann Jakob Wepfer (1620–1695) was the first to use animal experimentation for pharmacological or toxicological actions.

Rudolf Buchheim (1820–1879) founded the first institute of pharmacology at the University of Dorpat (Tartu, Estonia) in 1847, which firstly made pharmacology as an independent scientific discipline. In addition to a description of effects, he strove to explain the chemical properties of drugs.

Oswald Schmiedeberg (1838–1921), together with his many disciples, helped to establish the high  reputation of pharmacology. He partnered with pathologist Bernhard Naunyn (1839–1925) to found the first journal of pharmacology, which has since been published without interruption.

After 1920, the pharmacological industry had their own pharmacology laboratories outside established university institutes. After 1960, departments of clinical pharmacology were set up at many universities and in industry.

References

1. Clinical Drug Therapy: Rationales for Nursing Practice – Seventh 7th Edition, Lippincott Williams &Wilkins.
2. Basic&Clinical Pharmacology, 12^th Edition, McGrawHill Lange.
3. Modern Pharmacology with Clinical Applications, Sixth Edition, Charles R. Craig and Robert E. Stitzel, Lippincott Williams &Wilkins.

Sometimes, your back itches slightly and scratching it at that perfect spot fills you with an odd sense of happiness. Other times, you notice a biting itch on your arm and a chickpea-like redness shows up there. Oh, those mosquitoes! It is rarely likely to catch a mosquito in the act, and sometimes it even feels as if their bites just appear out of thin air. As you scratch the blister to soothe the itchiness, your eyes scan the room to locate its infamous proboscis. You see it on a wall, plump with the blood it sucked from you. You cannot help thinking: Why do their bites always leave so much itching? Or even, what is the purpose of itching at all?

Itching is an unpleasant feeling we perceive by our skin and mucous membranes, and an occasionally uncomfortable and sometimes very excruciating feeling.

Itching, just like pain, is a sensation intrinsic to our body to protect itself [1].  It is the way our skin “talks” to us. Indeed animals, even fish, itch too. When itched, our skin instinctively and in its own tongue tells us, “There is something that bothers me and I want you to push it away from me immediately!” If it was not for itching, we would not notice a spider walking on our arm. We would not be disturbed by lice and scabies mites or even fungi that settled on our skin, and we would not try to protect ourselves from these pests either.

An ordinary scabies patient has an average number of about 15-20 adult scabies mites on their skin. In the case of Norwegian or crusted scabies, which is most commonly observed among the elderly, the bedridden, people with seriously weakened immune systems, or those who are unable to itch themselves sufficiently, there are thousands of parasites under the thick crusts of the skin [2]. Itching accelerates the blood circulation on the itched parts, and tissues virtually prepare to fight infection by the rushing blood cells and substances [3]. Yet, millions of people also suffer from chronic itching and scratch their itches much more than usual. To understand this, we need to set on a journey from our skin to our brain.

Human skin consists of three layers: epidermis, dermis and subcutis (also known as hypodermis). The dermis layer in the middle makes glove-like protrusions upward into the epidermis. At the top of these protrusions are mechanoreceptors and nerve endings that allow our skin to sense stimulus (such as temperature, sharpness, pressure, vibration, pain, or itching) [3]. With these receptors, our skin functions as one of our five sensory organs and more like an “alarm system” of our body against changing conditions outside. This alarm system has been created so perfectly that each component knows exactly what stimulus to detect.

Previously, it was thought that pain and itching were sensed by the same receptors (nociceptors) and that mild stimuli were responsible for itching while strong stimuli were responsible for pain [4]. Yet, a contradiction existed because while pain triggered an avoidance reflex, itching activated the scratching reflex. In recent years, it was discovered that the receptors (pruriceptors) that perceive the itching sensation on the skin are the free boundary terminations of C-fibers with myelin-free, slow conduction velocity extending in the form of tree branches toward the upper layer of the skin. Furthermore, it was found that the skin cells themselves behave like itch receptors [3, 4]. When we receive a stimulus that induces itching, such as a mosquito bite which leaves anticoagulant substances on our skin, the mast cells in the skin tissue spring to defense against those alien substances. This ensues the secretion of the bodily defense system called mediators, substances that are produced and stored by mast cells as precursor for emergency conditions. Histamine is the most known of these substances and is the most important mediator in itching conditions [5]. Histamine binds to receptors found for itself in myelin-free C fibers that are tasked for detecting itching on the skin. If we consider histamine as a key, the lock that it fits into is on the nerve that senses itching. Thus, the itching nerve is stimulated by histamine.

The nerves receiving this stimulus connect to the spinal cord at their respective levels and transfer the message to another nerve. Each of these transfer processes is mediated neurotransmitters. The last message transmitted to the brain through these nerves is assessed by the brain and labeled as “itching” [6]. The brain determines the coordinates of the itching location and orders the scratching action to the related muscle system. A new journey that conveys messages from the brain to the arm muscles ends with scratching. Considering the swift rubbing action when we feel an ant walking on our face and scratch to push it away, we may value how fast and perfect our brain and transmission system work.

It is also rather odd how soothing itching can be despite its initially uncomfortable feeling, almost as if our body is rewarding us for saving it from a threat. There are several reasons for this contradiction. Scratching causes a low-intensity pain on the skin. Pain and itch are positioned on the skin alternately. The transmission of the sensation of pain is prioritized while the transmission of itching is prevented [7]. Consequently, our brain senses the pain and, in response, secretes the hormone called serotonin to soothe the body. Although this makes us feel relaxed for a short time, the brain continues to transmit virtual sense of itching by connecting to the receptors that are located on the spinal cord along the same nerve path with the receptors for serotonin [8]. This condition, which may be termed as a vicious cycle of itching-scratching, unsurprisingly infuriates patients. Scratching the same area on the skin continuously causes the production of new mediators and oversensitivity of itching nerves, which can thus turn itching into a chronic distress. Chronic itching can often result as a complication from skin diseases such as scabies, lice, eczema, fungal diseases, or drug allergies. It can also result from a systemic disease such as chronic renal failure, cholestatic liver diseases, thyroid problems, iron deficiency anemia, blood diseases and, rarely, cancers [7]. Itching in systemic diseases can be triggered by mediators on the skin but also by neurotransmitters in the intermediate pathway. This kind of itching cannot be controlled by drugs called antihistamines which block the histamine pathway. Sometimes the brain will receive false itching alarms due to post-shingles contraindications or nerve damage in the vertebrae. Such episodes of itching need to be addressed to prevent adverse outcomes. At times, the reason an itch can occur can even be psychological when there seems to be no need for an itch. According to research, scratching activates the brain’s reward center which triggers the addiction mechanism. Patients in that case are thrilled as they itch constantly [9].

As doors in this mysterious journey of science are opened one after another, we discover that nothing has been created without a purpose, including apparently discomforting sensations such as itching, which, it turns out, is how our skin communicates with us!

References

1. Arıcan O. Kasintinin patofizyolojisi, klinigi ve tedavisi Turkderm 2005;39(2):88-97
2. Jonston G, Sladden M. 2005 Scabies: diagnosis and treatment BMJ;17;331(7517):619-22
3. Guyton AC, Hall JE. Tıbbi Fizyoloji 10. Baski 2001.p815-42
4. Schmelz M. Itch and pain. Neurosci Biobehav Rev 2010;34(2):171-6
5. Arck P, Raus R. From the Brain-skin connection. Neuroimmunomodulation 2006;13(5-6)347-56
6. Metz M, Stander S. Chronic pruritus pathogenesis clinical aspects and treatment. J Eur Acad Dermatol Veneral 2010;24(11)1249-60
7. Metz M, Grundman S, Stander S. Pruritus: an overview of current concepts. Vet Dermatol 2011;22(2):121-31
8. Chen ZF et all. Descending control of itching transmission by Serotonergic System via 5-HT1A-facilitated GRP-GRPR signaling. Neuron Vol.84(4) Nov.19-2014

9. Chan YH et all. Brain’s Reward Circuits Mediate Itch Relief. A functional MRI Study of Active Scratching. Dec. 2013

Organic substances in the soil go through oxidative decomposition depending on factors such as temperature, air, humidity, and pH balance. This is a slow burning (oxidation) event of organic substances. However, oxidative decay is hindered if one of the aforementioned factors is lacking. Then, a slow decay of organic materials in soil called humification takes place.

Humification occurs in an open system in contact with air. For example, early chemical processes start with leaves changing color in autumn. The break down and partial ingestion of leaves by soil organisms follows. During this time, water soluble carbohydrates and proteins leave the leaf tissue. What remains behind are plant structures like cellulose and lignin, which are not broken down yet. Since leaf shapes are not completely deformed, species identification can still be possible at this stage. In the decay step, however, the cellulose and lignin are decomposed by various fungi species and converted to humus.

Humic substances and their properties

Humic substances are intermediate products that occur as the result of organic materials going through a series of chemical reactions. These intermediate products are humic acid, fulvic acid, and humate. Their molecular weights are around 1.000-10.000 gr/mol, 10.000-100.000 gr/mol, and 100.000-10.000.000 gr/mol, respectively. Humic acids contain weak aliphatic (carbon chains) and aromatic (carbon rings) organic acids that are soluble in water when it has a base medium but insoluble under acidic conditions.

Fulvic acids with smaller size molecular structures can reach plant roots, branches, and leaves easily because they are soluble in water under all pH conditions (acidic, neutral, and basic). Thus, trace elements such as iron, zinc, copper, manganese, and boron can be easily transported to plant tissues via fulvic acid.

Humates, however, are insoluble in water. Only the portion of a humate called ulmic acid can dissolve in alcohol.

Major functions have been assigned to humic matter in the nutrient and carbon cycle, as they are inseparable members of the ecosystem. Plants capture significantly more nutrients from humic matter than from clay minerals. Even though they can be depleted from soil by certain agricultural practices in less than 50 years, they can still remain in natural soils, outside human activity, for hundreds or even thousands of years without being degraded. This very long presence in soil enables them to continue their functions longer. According to radiocarbon dating, humates can last approximately 1140 years; and humic acid and fulvic acid last for 1235 and 870 years, respectively, in natural soils.

Positively charged nutritious elements (cations) remain in the soil by binding to negatively charged (anions) in humic matter. Because this bond is weak, useful elements for the plant can easily be exchanged with another cation, becoming free and getting absorbed by the plant. On the other side, cations such as iron, copper, zinc, magnesium, manganese, and calcium, which are hazardous to plants when taken excessively, are held in the soil, bound to humic matter and thus not causing toxicity.

Another significant feature of humic and fulvic acid is their ability to form water bridges. Water bridges facilitate the movement of nutrient ions towards roots via soil solutions.

Aside from agriculture, humic matter, with its aforementioned properties, serve humankind in the industrial, environmental, and biomedical fields.

Industrial and environmental applications

Humic matter is utilized in the staining of leather works, as wood lining paint (natural blue color), as well as water based stripping material for furniture stains. Humic matter is also used in the production of durable, resistant papers in the paper industry, to provide mechanical strength to processed ceramics, and as an additive. It is also applied as a coloring, hardening, and plasticizing agent in plastic fabrication.

Humic and fulvic acids gain significance regarding their ability to form water soluble substances with many metal compounds containing radioactive elements in their structure.

In environmental chemistry, the main role of the humic matter is to remove toxic substances, human sourced organic chemical matter, and other pollutants from water. Calcium humate, obtained from humic matter, can bind and remove nickel, iron, cadmium, and copper in addition to radioactive elements produced at nuclear power plants from water.

Humus based filters are designed to treat sewage water and mud waste. Oils, stains, poisonous phenolic substances, and pesticides are removed from sewage via these materials. In poultry, humic substances are employed to absorb and eliminate the odor of waste gases.

Biomedical applications

Drugs for the treatment of human and animal diseases are developed from humic matter. These can be used for the treatment of viral and bacterial illnesses, in the prevention of blood clots, to cure infections, and to remedy estrogen deficiencies. Clinical studies have shown that common viral diseases of children’s respiratory tracks can be treated with fulvic acid supplements. A lot of medical research has shown that humic matter, especially fulvic acids, have the ability to provide protection against cancer causing viruses. In a study, laboratory mice were given ethanol to trigger gastritis and it was determined that humic acids supplied to mice led to a significant reduction in the harm gastritis caused. The fact that humic acids can form compounds with heavy metals, such as cadmium, enables the excretion of heavy metals from organisms.

In our universe there is no place for waste. Once every particle completes its task, it is returned in a different fashion to be assigned another job. Humification is a good example to this reassignment as a complex recycling event in the soil. It is amazing to observe everything being generated from one thing and everything converted into one thing so easily and in such a crafty, balanced, and organized fashion. In fact, the power and wisdom behind the conversion of the remains of millions of different organisms into a few similar substances to be employed in different tasks are no less amazing.

Though less known than drug addictions, status addiction can cause serious harm to individuals and society.

One of the essential mistakes some people who attain a certain status in our time make is their failure to see how transitory worldly positions are; they act as if this world is permanent. Why do some people’s characters change when they are promoted to a certain position? Why do some character flaws surface after gaining a certain status? It is known that the human carnal soul has different forms of weakness, and is inclined to develop certain forms of worldly addictions, and love of status is one of them. When a person comes to a high position, he or she often gains a different mood with the new power and means they’ve obtained. Sometimes, this means maintaining one’s internal balance – and sometimes it means losing that balance. The latter situation might stem from negative feelings that had, until then, been suppressed.

Some people develop an addiction to substances that stimulate their sense of reward. In time, psychological addiction is accompanied by the biological addiction, and the dose demanded for satisfaction increases. If it is not achieved, feelings of deprivation can arise, and from this, crises surface. . Consequently, the person becomes totally addicted. Addiction for status develops in the same pattern. The only difference is that what causes the addiction is not a chemical substance, but the status itself.

The person is virtually drugged with the effects of power and the opportunities in hand, along with the respect and interest shown by others. Therefore, one does not only fear losing the opportunities, but also this respect and interest. The person does whatever one can in order to make things continue as they are. Similar to a drug addict who resorts to illegal means for the sake of finding drugs, the person will use any means to retain power. What matters is only the continuity of the position and the status possessed.

After one chair, the status-addict looks for the next chair like a drug addict craving drugs. As the body develops a tolerance for narcotic substances, and the person seeks higher doses, the status-addict looks for an increase in interest and respect from others. The least degree of indifference or being normal treatment makes the status-lover lose their temper. For this reason, he does not like to keep around those who fail to show excessive respect and who make occasional warnings about his behavior. He continually looks for people to behave like servants at his beck and call. In the end, the status-lover will be surrounded by flatterers instead of sound advisers, who might bring him to his senses. This only adds to his pleasure more, as he needs higher doses for satisfaction.

People with good qualifications, whom appear to be potential rivals, evoke a great disturbance in status-addicts. Such individuals are quickly destroyed, before they can prove themselves. Therefore, both the addict’s position is retained and the ones who might discover their mistakes are handled. Status-addicts sometimes make unjust decisions and enforce them for the sake of intimidation. He is the most successful and rightful person, because his own potential and intelligence come before everything. Consultation and meetings are routine tasks to let pass. The status-addict does not accept anybody’s opinion but his own, does not listen to different ideas, and uses meetings as shows of power to satisfy his ego. After some time, this dizzying mood causes serious mistakes. However, as nobody to bring them to their senses remains, the consequences are grim.

The treatment process for status-addicts requires balancing the heart and mind, and also activating the spiritual dynamics. Otherwise, the person totally goes astray, both materially and spiritually. The egotistic behavior of the status-addict harms the addict, first of all, and also harms those around them.

All worldly positions are temporary, and being aware of this might be helpful in treating status-addiction. God Almighty will call people to account for all of the blessings He gave. There are other people who are more talented, or who have better capacities, than we do. Graveyards are full of people who once assumed that everything depended on them. When one is dismissed from a certain position, the extremeness of that person’s reaction is in direct proportion with the degree of addiction. All that matters here is a person’s continuing one’s relation with God, not upsetting the balance of the heart, not forgetting that this world is temporary, and giving this world and the next as much value as they deserve.

Skin is composed of two main interwoven layers of dermis, on the inside, and epidermis, on the outside. The epidermis, which is composed of five sub units, possesses the most important sign of our identity. Each thin layer is arranged in a way to carry out different tasks. A significant amount of elasticity and flexibility is provided to skin via these five layers. These layers can glide on each other slightly and can also be compressed under pressure. They are compressed when we sit on a hard surface. This situation can be similar to the compression of the spring in a click pen, or the suspension of a vehicle under a load. They regain their previous state upon termination of the pressure, like standing up. This elasticity is crucial for skin’s integrity.

The thin construct of our skin contains sweat glands that are embedded in the fibrous connective tissue. There are sensory receptors, hair roots, and hair muscles connected to them, and also loose nerve endings, and a network of capillary vessels. Free nerve endings are created to specialize in various functions so as to sense hot, cold, pressure, and pain. Likewise, the continuation of blood flow relies on very intricate calculations that are hard to explain. When blood vessels arrive at the skin, they are dispersed like a net in the form of capillaries.

The blood pressure of the arteries located at lower section of the skin is higher than the pressure of pulmonary veins. If pressure is applied to skin for a long duration from outside, the pressure in the pulmonary veins builds up and regional blood flow is disrupted. Therefore oxygen, glucose, and other nutritional substances cannot be delivered to these areas; along with inhibition of waste product removal, it leads to a nutritional abnormality in the tissue.

Sensory cells within our skin detect and report nutritional abnormalities of tissue to our brain via various chemical substances (like acetylcholine, bradykinin, and histamine). Thus we change our position consciously or subconsciously with the intervention of our brain to avoid the danger of a nutritional abnormality, and therefore the area regains normal circulation. In this stage, the process is still reversible; however, should the pressure continue, skin cells will start to die from, from the outside in. These systems do work well in healthy persons but in cases of stroke or coma, the intervention system does not work.

This critical picture can be understood better with an example. Just like roads need to be used in order to carry goods and remove trash, the transportation of minerals, vitamins, and many other life saving substances to the distant parts of the body and removal of waste products requires blood vessels to remain open. This must continue in a perfect balance without any interruption throughout our lives.

If a pressure ulcer occurs, it is like being exposed to external dangers in a house if a door or window breaks. It is like a free entrance visa is granted to germs that were blocked. Our back and pointy areas, like, thighs knees, heels, and shoulders are under more pressure, and therefore at more risk when we lie down. Two to six hours of pressure to one of these areas is enough time to disrupt skin integrity. Our daily sleep requirement is around 6-8 hours, therefore we need to switch positions a couple of times during our sleep. Therefore we face this risk everyday in our sleep; however, thanks to the perfectly functioning protective systems, without noticing during our sleep, our position is changed and this dangerous situation is avoided. Intensive care doctors and staff know better what a great blessing that is are since intensive care patients are mostly unable to move. Despite the use of many preventive efforts, like turning the patients in certain periods or the use of air beds, pressure ulcers still occur and a significant portion of patients die of the microbial infections caused by these wounds.

The story of sleepers

“The Seven Sleepers” story in the Christian tradition is retold in the Qur’an as “the People of the Cave.” The story is about a group of young believers who took refuge in a cave fleeing the oppression of the pagan Roman emperor. Both traditions narrate that they fell asleep in the cave, where they stayed asleep for hundreds of years. The Qur’anic account, however, mentions that they were made to change position during their centuries-long sleep: “You would have thought them awake though they were asleep. We caused them to turn over to the right and the left…” (18:18). It is an interesting nuance that they were made to change position, for it sounds rather irrelevant to the rest of the story. However, with the medical conditions of our skin that were explained above, this nuance makes perfect sense as advice to us on how we should treat patients who are unable to move.

Some medications are effective directly over the area they are applied to. Some however are transported to distant regions via blood flow and that is where they are most effective. Medication is either taken orally or through injection. When medicine passes into the blood stream from the place of administration, it is considered to be absorbed. A good example is the transportation of medicine into the blood stream of capillary vessels between the muscle cells when injected into muscle tissue. A drug taken orally however is absorbed through the blood vessels in the gastro-intestinal system.

For orally-taken medication to be absorbed, it should be able to dissolve in gastro-intestinal fluids. First, it is broken into smaller units due to the corroding effects of stomach acid and various enzymes are secreted, then chemicals in the drug composition pass into the gastro-intestinal fluid in a molecular form. This event resembles the dissolving of a sugar cube inside a glass of hot tea. First, the sugar cube gets broken into pieces and then dissolves. A mix with a tea spoon makes this event happen a little faster. In a similar fashion gastro-intestinal movements help with the absorption of medicine. Liquid drugs like syrups dissolve in the gastro-intestinal fluid faster since they are already in smaller units; therefore they get absorbed faster.

Drugs mostly get absorbed through the small intestine. The most important task of this organ is to enable the absorption of nutrients. It is approximately 10 meters long and 4 centimeters wide. The inner lining of the small intestine has finger-like projections called villus and even smaller projections that are located on these villi are called microvillus. One of the reasons, maybe the most important reason, why the our intestines are created in this way is that as a result, the inner surface area of intestines increases multifold. Such that the inner surface area of a human beings small intestine can increase up to 200 m2 and this greatly facilitates the absorption. These projections are made of intestinal cells.

The molecules carrying the medication reach the capillary vessels by passing through these cells and then join the blood stream by crossing through capillary vessel cells. Furthermore, intestinal cell membranes host a special protein that filters unwanted substances for the cell and returns them back to intestinal lumen. Thus these unwanted substances are excreted out of the body along with other unabsorbed matter. In the same way, some drugs are held by this protein and released back into the lumen thus decreasing absorption rate for drugs experiencing this reaction.

Liver: The organ responsible for eliminating the harmful effects of medication

As soon as medication joins the bloodstream after absorption, it is first transported to the liver. This is because pulmonary veins that collect blood from the intestines are connected primarily to the liver. One of the many functions of the liver is the elimination of harmful substances entering the body. For this reason, absorbed substances are directly sent to the liver. The liver is employed with the task of chemical conversion with these substances that are transported to it. One of the wisdoms behind liver metabolism is to reduce the effects of these harmful substances via these events and to convert them into an excretal material. In the same way, drugs are metabolized in the liver, lose their efficacy and prepare for excretion.

Many drugs interfere with each other’s metabolism. If one drug’s metabolism is inhibited, blood concentration of such chemicals increase and adverse effects of drugs become more frequent. Irresponsible drug use must be avoided for this reason. Drug interactions may lead to major damage in addition to the drug’s individual adverse effects. Moreover different nutrients also affect drug metabolism. For instance, grapefruit inhibits metabolism of certain medicines, as a result blood concentration of these medicines increase and adverse effects can be observed. On the other hand, some nutrients like broccoli, cabbage, and charcoal roasted meat speed up the metabolism of certain medicines. In this case, the blood concentration of the affected drug drops and may lead to reduced benefits from intended use. Because of this reason, patients on long-term medicine treatment should not consume these types of food.

The rest of the drug molecules that escape these metabolisms is directed towards blood vessels feeding other organs. Some drug metabolisms in the liver present individual differences as metabolic levels change from person to person. Thus, a drug with the same dosage develops desired blood concentrations for some people, fails to meet this level for others or can even cause high blood concentrations enough to generate adverse effects in other individuals. That is why a medicine that has benefited a patient should never be used by somebody else without consulting a doctor.

The function of bile

Bile secretion originating from the liver and gall bladder has critical importance in the digestion and absorption of fats. Bile breaks apart fats into small pieces so that digestive enzymes can affect them. As a result of this, absorption is provided for fats and vitamins like A, D, E, K that are soluble in fats. In a similar fashion bile improves solubility and absorption of some drugs that does not dissolve in gastro-intestinal fluid. Another task of bile secretion is the removal of certain substances from the body. Waste materials in the bile that is dumped into duodenum are excreted through the digestive track. Some drugs are excreted in this way.

Drug intake before or after meals

It is a well known practice that medications are advised either to be taken after or before meals. When medications are taken after a meal, they cause less of the possible unwanted disturbances such as stomach sickness, aches or indigestion.

On the other hand, nutrients may reduce intake of certain drugs, therefore they need to be taken before meals. However medications taken right before a meal does not apply in this case since the food will still mix with the medication in the stomach. When taking these medicines, it should at least be an hour before meals. Generally consumption of a medicine before or after a meal does not really change its absorption level. But medications taken before meals pass the stomach into the intestines without delay and therefore get absorbed faster. This practice is important in cases where an immediate effect is desired such as pain relief. Plentiful water intake also helps with faster and improved absorption of drugs.

Some medications are packed into capsules made of gelatin-like substances. Medicines with undesirable taste and smell can be offered in this form for consumption. Moreover, if a drug is harmful to the stomach or gets degraded in stomach acid, then this drug can be prepared in capsules that are durable to stomach acid but soluble in the intestines. That is why consumption of medication without its intended capsule should be avoided. In a similar fashion, some medicinal tablets are designed to deliver its molecular contents particularly to the intestines. These types of medication must be taken as a whole unit. Otherwise it can be ineffective or may lead to harmful reactions.

Delivery of drugs to targeted regions

The molecules carrying medication that join the blood via absorption get dispersed by blood circulation throughout the body. These molecules reach various parts of the system via blood vessels, and then diffuse into organs via capillary vessels. However, their entry to the brain is difficult because this vital organ of the body has a special protection to guard itself from possible harmful effects of various substances that enter the body from the outside. Capillary vessels in the brain are different from other capillary structures in the rest of the body as they are created without an intercellular space in between vessel cells. Furthermore, these cells are bound to each other with their tight connective regions.

These capillaries are surrounded by a thicker membrane compared to other capillary vessels. This membrane is also host to various cells that wrap around the vessel. Therefore, because of these factors and other similar ones, some medications can enter the brain in very limited amounts. Drug molecules can display their targeted effects when they bind to target proteins, called receptors, in the organs. These proteins, which are very unique to each drug, exist on the cell membrane or in the cell. In addition, drug molecules also bind to other receptors that are not specific for them, and this causes adverse effects as a result.

Excretion of drugs from the body

Drugs are excreted from the body via the liver and kidneys. One function of these organs is to filter the blood from foreign substances. It was previously mentioned that absorbed substances from intestines are transported to the liver first where some amount gets metabolized and the remaining amount rejoins blood circulation that feeds other organs. Drug molecules that pass through the liver return back to it repeatedly many times because of continual blood circulation. In each of these arrivals, some amount is again metabolized. Molecules of metabolized drugs are excreted out of the body via the kidneys and through the bile at a limited level.

Only some portion of drug molecules get excreted via the kidneys without being metabolized. This ratio is higher with some medications. These types of medications are considered to be removed only by the kidneys, whereas some other drug types cannot be excreted without getting metabolized through the liver. As previously mentioned, the purpose of drug metabolism is to convert drugs into easily removable forms. If these types of drugs are not metabolized, they are rejoined to the blood circulation after filtration by the kidneys without joining the urine. It is impossible for the liver to sense these happening within the kidneys if it was not that the liver and every cell in it were employed by one authority who created them in the first place. Drug molecules concentrate in the liver and kidneys since these organs are employed with drug removal. As a result harmful effects of drugs are often experienced in these organs. Therefore unnecessary drug use should be avoided, otherwise the health of these organs deteriorate and eventually fail to carry out their basic functions.

As noted above, events that are taking place within many of our organs, stomach and elsewhere like kidneys impact on the journey of drugs in our body, therefore changing its effect. The harmonious creation of our organs that are home to many miraculous events is the major component of the entire process in which causations have their due role only as much as they are allowed by their Creator. As a test for humankind, both illness and the cure is provided by God, the All-Healer. Therefore it is the duty of a patient to see a doctor, take the medication properly and never forget that cure is only provided by the Almighty, without obsessing over causational chains.

References

• Guyton, Arthur C., John E. Hall. 1991. Textbook of Medical Physiology, Saunders.
• Patton, Kevin T., Gary A. Thibodeau. 1993. Anatomy & Physiology, Mosby.
• Rang, Humphrey P., Maureen B. Dale, James M. Ritter. 1999. Pharmacology, Churchill Livingstone.
• Brunton, Laurence, John Lazo, Keith Parker. 2006. The Pharmacological Basis of Therapeutics. McGraw-Hill Professional

Today, more than 1 billion people are suffering from the lack of potable water. About 2.3 billion people (41 percent of the earth’s population) live in regions with water scarcity; this number is estimated to be 3.5 billion by 2025.1

96.5 percent of the world’s water is found in seas and oceans, and the remainder is found as ice caps, brackish water, and fresh water sources (e.g. lakes, rivers, and ground waters). To overcome water shortage problems, methods such as water conservation and dam construction have been applied for several years, but they are not enough against increasing water demand and decreasing fresh water sources.2

Water is also very important for generating energy, and vice versa. The largest portion of U.S. electric production is provided by thermoelectric power generation, where steam-driven turbine generators are used to generate electricity. In 2000, thermoelectric power plants used 39 percent of all fresh water sources in the United States.3 All these reasons make the production of drinking water a worldwide issue.

Desalination

Since most of world’s water supply is found in oceans and seas, desalination is the process of removing salts and minerals from either ocean or brackish water to make it safe for human consumption and use. The most widely applied desalination processes are divided into two main categories, thermal distillation processes and membrane processes.

Desalination via thermal distillation methods, which separate liquid mixtures based on their boiling points, mainly fall into three categories: multi-stage flash (MSF), multi-effect distillation (MED), and mechanical vapor compression (MVC). Thermal distillation processes require the evaporation of water while leaving the salt in a concentrated brine. Middle Eastern countries mainly use thermal-based desalination plants to produce fresh water because of their easily accessible fossil fuel sources.2, 4

Membrane-based separations are the main choice of producing potable water in countries outside the Middle East. More than 50 percent of the newly installed desalination plants have been using reverse osmosis (RO) membrane technology (since 2001).2

Membrane separations

A membrane is an interphase between two adjacent phases acting as a selective barrier, regulating the transport of substances between the two compartments. It is a very thin film that allows passage of some types of substances while preventing the passage of other substances, depending on their sizes. Membranes used for separation technology gave rise to an interdisciplinary area including many fields of science and engineering such as chemistry, chemical engineering, material science, process engineering, environmental science, ecology, and economics.5, 6 Today, the membrane industry is impressively large. The membrane separation technology market is quite diverse and ranges from medicine to the chemical industry, and the most important markets are medical devices and water treatment. There was a $2 billion sale of synthetic membranes worldwide in 2003.6

Water purification membranes

Water treatment processes employ several types of membranes. They include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes. They are designed to remove materials of increasing sizes. MF membranes have the largest pore size and typically reject large particles and various microorganisms. UF membranes have smaller pores than MF membranes and, therefore, in addition to large particles and microorganisms, they can reject bacteria and soluble macromolecules such as proteins. RO membranes are effectively nonporous and therefore exclude particles and even many low molar mass species such as salt ions, organic substances, etc.7 NF membranes are relatively new and are sometimes called “loose” RO membranes. They are porous membranes, but since the pores are ten of angstroms or less, they exhibit performance between that of RO and UF membranes.8 Of these membranes, NF and RO membranes constitute the dominant technology for desalination of water.9

2.1 Nanofiltration Membranes

Membranes for nanofiltration (NF) are usually comprised of cellulose acetate or aromatic polyamides. NF allows diffusion of organic compounds, and rejects some salts with low pressures being applied. NF itself cannot purify seawater to drinking water standards, but it is a process that can be used to produce mildly salty water, or as a water-softening technique.2, 4 When NF is coupled with RO, then it can be used to turn seawater into drinking water.10

Nanofiltration membranes usually have negative charges (e.g., carboxylate groups, sulfonate groups, etc.), and as a result, ion repulsion is a major factor in determining salt rejection. More highly charged ions, such as sulfate, are more highly rejected than monovalent ions, such as chloride, by a negatively charged nanofiltration membrane. In particular, NF membranes are used to remove divalent ions such as calcium and magnesium, which are mainly responsible for water hardness. These membranes also usually display good rejection of organic compounds with molecular weights above 200 to 500 grams.2,11,12

2.2 Reverse osmosis membranes

Osmosis is a natural process in which water molecules move across a semipermeable membrane from a lower solute concentration area to the higher solute concentration area. Water flows until a chemical potential equilibrium of water is established. When equilibrium is reached, the pressure difference between the two sides of the membrane is equal to the osmotic pressure of the solution.12

Reverse osmosis (RO) is the process of forcing water from a region of high solute concentration through a membrane to a region of low solute concentration by applying a pressure that is greater than the osmotic pressure. As a result, separation of water from the solution occurs as pure water from the high concentration side to the low concentration side. The RO process includes a feed water source, feed pre-treatment, a high-pressure pump, RO membrane modules and post-treatment steps.

RO membranes are capable of rejecting monovalent ions such as sodium and chloride, which makes the RO process a valuable method for desalination. Membranes used for RO processes have salt rejections of more than 99 percent. RO membranes do not have distinct pores, but rather rely on free volume within the polymer film.

RO membrane separations depend highly on the properties of the polymer film such as the chemical and physical structure of the membrane material. Desired RO membranes should be resistant to chemical substances and microbial organisms, stable over a long time both mechanically and structurally, and have ideal separation properties such as high water flux, high salt rejection, chlorine, and fouling (clogging of membrane pores) resistance.

Approximately one billion of six billion people in the world live in water-stressed areas, and RO membrane technology is the leading desalination technology to overcome the problem of insufficient clean water and estimated to continue its leadership in the near future.13 Scientists and engineers are extensively investigating the development of the most efficient membrane desalination technology to produce the cheapest potable water.

On the other hand, cells use membranes, though scientists do not try to further develop them, since they were already designed in a perfect manner. Cellular membranes have a phospholipid structure with embedded proteins. They control many different kinds of transportations of substances in and out of cells (e.g. sugar, drugs, ions). They are so well designed that they know which substances are helpful or harmful for the cell, and decide on the passage of substances based on that. Many researchers have tried countless times for many years to produce an equally wonderful membrane technology for making clean water. But cellular membranes, consisting of hundreds of functions in living organisms, do not form spontaneously.

REFERENCES

1) R.F. Service, Freshwater resources, desalination freshens up. Science, (2006). 313, 1088- 1090.

2) L.F. Greenlee, D.F.Lawler, B.D. Freeman, B. Marrot, P. Moulin, Reverse osmosis desalination: Water sources, technology and today’s challenges. Water Research (2009), 43, 2317-2348.

3) T.J. Feeley, T.J. Skone, G.J.Stiegel, A. McNemar, M.Nemeth, B. Schimmoller, J.T. Murphy, L. Manfredo, Water: A critical resource in the thermoelectric power industry.Energy (2008), 33, 1-11.

4) G. A. Tularam, M. Ilahee, Environmental concerns of desalinating seawater using reverse osmosis. J. Environ. Monit.(2007), 9, 805–813.

5) P. Vandezande, L. E. M. Gevers, I. F. J. Vankelecom, Solvent resistant nanofiltration: separating on a molecular level. Chem. Soc. Rev.(2008), 37, 365–405.

6) M. Ulbricht, Advanced functional polymer membranes. Polymer (2006), 47, 2217–2262.

7) R.H. Perry, D.W.Green, Eds., Perry’s Chemical Engineers’ Handbook, 7th ed., McGraw-Hill: New York, 1997.

8) Sagle, A., and B. Freeman, “Fundamentals of Membranes for Water Treatment,” in The Future of Desalination in Texas: Volume 2, Report Number 363, Texas Water Development Board, Austin, TX, pp. 137-154 (2004).

9) H.B.Park, B.D.Freeman, Z.Zhang, M.Sankir, J.E.McGrath, Highly Chlorine-Tolerant Polymers for Desalination, Angew. Chem. Int. Ed. (2008), 47, 6019-6024.

10) N. Hilal, H. Al-Zoubi, N. A. Darwish, A. W. Mohammad, M. Abu Arabi, A comprehensive review of nanofiltration membranes: Treatment, pretreatment, modelling, and atomic force microscopy, Desalination (2004), 170, 281-308.

11) A. Gorenflo, D. Velazquez-Padron, F.H. Frimmel, Nanofiltration of a German groundwater of high hardness and NOM content: performance and costs. Desalination (2002), 151, 253-265.

12) M.E.Williams, A Brief Review of Reverse Osmosis Membrane Technology,EET Corporation and Williams Engineering Services Company, Inc., Harriman, TN, 2003.

13) K. P. Lee, T. C. Arnot, D. Mattia, A Review of Reverse Osmosis Membrane Materials for Desalination – Development to Date and Future Potential. J. Membr. Sci. 370 (2011) 1-22.

We agreed with the other organs to explain the splendid art inherent in us to you; we have patiently waited our turn. Our aim is to remind you to look after yourself so you will continue to live a healthy life and consciously perform your duty of servitude to our Lord Who created us. In addition to your perfections, as human beings you also have certain faults, such as being negligent, deceptive, or forgetting easily. Even if you realize that these are your faults, each bears a distinct wisdom in terms of Creation. If from time to time you can succeed in avoiding this negligence and escaping these experiences by using these shortcomings as a springboard or platform from which to depart, you will be able to reflect and contemplate on the attributes of God with greater admiration.

Indeed, we are just inside the gateway of the body that opens to the outer world, the mouth, an area through which the various substances you eat to stay alive pass through the mechanic process we implement before actually entering the body.

When food first enters the mouth, it is passed through a grinding process that carries out a mechanical breakdown before the chemical breakdown in the stomach and intestines. We teeth are aligned along on your lower and upper jawbone. When you were only a two-month old fetus, the Creator Who is aware of the importance of our tasks began to prepare us, and we were planted, just like a seed sown in the earth, in the crevices in your jawbone, and concealed by your gums. But still, we do not appear immediately after birth, because we may hurt your mother when she is nursing you. Initially, it is necessary for you to be fed with that unique nourishment, your mother’s milk. However, we begin to gradually emerge in the form of tiny stumps while you are still being nursed by your mother, when you are around six or seven months old.

We were created to cut, chew, and grind food of various textures and hardness. The number and mechanical functions of my colleagues, who have names such as incisors (cutting teeth), canines, premolars, and molars vary. The incisors, which are at the front, begin to appear when you are still only 6–8 months old, the ones immediately beside them erupt when you are 8–12 months, the premolars appear when you are 12–16 months, the canines at 16–20 months and second premolars when you are between 20–24 months old.

During this period, we are known as the milk teeth. When you are 6–7 years old, the molars emerge and then when you are 7–8 years old the central incisors appear; between 8 and 9 years of age the lateral incisors, between 9 and 11 the first premolars, between 11 and 13 years the second premolars and the canines, and finally between 12 and 14 years of age the second molars erupt; the third molars, known as the wisdom teeth, usually appear any time between the ages of 17 and 40, although sometimes they do not come through at all. The two front incisors, the canine beside them, and the two premolars and three molars, that is, a total of eight teeth, constitute half of the jaw, but all the teeth work as a team of 32. Sometimes you may hear about humans who perform various experiments regarding our strength. My strongest chewing force was recorded as 1900 Newton. In a demonstration of strength, a human was capable of lifting a weight of 620 lb as high as 7 inches from the ground. Although each of us has different functions and appearances, in terms of where we are situated, in general our anatomic structures are the same. The enamel layer covering me is very hard and shiny. My enamel layer is even stronger than bone. My sections, which cut hard substances you put in your mouths like knives without bending, are in fact covered in enamel. Beneath the enamel surface is a solid, bone-like substance known as dentin, which has a slightly different composition than that of the bone found in other parts of the body. The space in the center of this layer (known as pulp chamber) is filled with blood cells and nerves that nourish me. The section of each of us that is buried beneath the jaw bone is called the root, while the part that is visible and which you brush daily is called the crown. Throughout your lives, everything you put in your mouths, whether it is hard, soft, corrosive or acidic, comes into contact with the crown. Some substances can damage us. Even stone or steel would not be able to withstand the conditions that we teeth are exposed to. Although made of metal, a carpenter’s saw becomes blunt, and even a blacksmith’s grinder looses it effect after a while. But if you take good care of us, we will serve you throughout your entire life. Unfortunately, I have noticed that you do not take care of us at all. You eat sweet things, but you do not clean us, you eat meat, but you do not brush us, you relentlessly use us to crack open nuts, and pour anything you find, whether hot or cold, over us. We can withstand this for now because we are still young, but it is impossible to say how long we can carry on like this. If any of us cracks and bacteria begins to eat away at us, eventually causing us to decay, you will start to complain, but it will be too late.

The Prophet Muhammad, peace be upon him, gave utmost importance to us in his daily life. Whenever the opportunity arose, after eating, before prayer, in the morning when he woke up, the Prophet constantly used a miswak, a cleaning twig, and cleansed us with affection. This is why we sparkled like pearls when he opened his mouth or smiled, and those close to him never sensed an offensive odor from his breath. But many people today do have bad breath because they neglect us. Not only does the smell of bad breath make others uncomfortable, but you are also causing harm to yourselves. After the bacteria that hides in the crevices on and between us makes a hole through the enamel and the bone beneath it, this bacteria then begins to spread to your entire body through the blood cells in the pulp chamber, causing damage to other organs of your body. These bacteria can damage vital organs, such as the heart or the kidneys. At first, you do not notice this, because this occurs over a long period. But these bacteria can gradually destroy many of your organs. When you do finally realize what has happened, it could be too late; your cardiac valves may have stopped working properly, or the filtering function of your kidneys may begin to fail.

If you begin to lose us one by one, initially you will notice the change in the taste of your food, then defects in your speech, and eventually you will notice facial deformities and sunken cheeks. You will have to make dentures at great expense, and only in this way will you be able to restore your appearance; but in terms of function, you will never be able to substitute us with those artificial dentures!

You know that one of the main characteristics that distinguish us from animals is speech. Although the focal point of speech is in the brain, speech actually emerges as a sound or words with the collective assistance of many other organs. These are mainly the lungs, the larynx (voice box), the ears and the tongue; but we too play a big role in the correct pronunciation of many letters and words.

In addition, the mechanoreceptors in us and the cell network in our roots display such perfect precision that when we chew, we do not bite your tongue or cheek. Therefore, you can adjust the force of biting pressure for substances of various textures. If these receptors and cell network did not exist, you would use an identical chewing strategy for eating substances as hard as an apple or as soft as pudding. In which case you could not bite an apple or you would attempt to eat pudding with excessive pressure, causing us to grind together with unnecessary force, even breaking us.

So you can see that nothing has been created without a purpose. Are there any unnecessary details in creation? Of course not! This is impossible; as the eternal wisdom and power of He who created us would never permit something which is deficient or of no purpose..!

Dear Peter! I think this should be sufficient in describing ourselves to you. Naturally, the food we breakdown is not in a condition to be swallowed immediately. Therefore, our neighbors, the salivary glands can explain what happens next…

Irfan Yilmaz is a professor of biology in Dokuz Eylul University, Izmir.

Dear Peter, in your body, which is built like a well-functioning factory, I am the most essential sanitary device. As the heart pumps blood to take food and oxygen to all your organs, you obtain the energy you need. But do you ever think about the disposal after so splendid activities are carried out in your body? If you burn a stove, you need to dispose of the smoke and the ashes if you want to keep it working. Likewise, as you burn your calorie intake, you dispose of the smoke (carbon dioxide) with your lungs and the waste with nitrate-poisonous after a certain level of intensity-thanks to my quietly and perfectly working filters. That is, I am an organ which saves your life by removing the poisonous substances in your blood. I do not only filter your blood, but also play a role at controlling the balances of the sensitive levels of water, sugar, amino acids and different minerals in your body. In short, I am a tiny but strategic laboratory.

The acid-base balance in your body and the amount of water and different salts are significant values which concern all of your bodily activities. When their balance is upset, different troubles arise in different units of your bodily mechanism. I am such a blessing, which works so sensitively to adjust the levels of water and mineral salts in your body while you don’t even realize it.

A watery environment is needed for the thousands of biochemical activities taking place in your body. In addition, activities like the contracting of the muscles and transmission of electrical stimuli between your neurons are realized with the presence of a pinch of mineral salt you don’t even give a thought about. Sometimes you sweat due to running or hot weather. The white stains on your shirt are the salts you lose after the water evaporates. When you suffer from diarrhea, you lose salt again, for the salt in the nutrients are thrown out without being absorbed. Especially when little children are concerned, this loss is of vital importance. The transfer between the blood and the liquid in the tissues is mainly realized through the concentration differences which are kept in a certain balance. If your body holds too much water, your tissues swell. You particularly feel it when you press your finger over the flesh near your shins.

Dear Peter, I will not list all of my duties in detail in order not to confuse you. However, let me tell you one more. Since not everyone knows this duty of mine, they just see me as an organ of liquid disposal. But I also take part in controlling the blood production! Surprised? Well, I also have the duty of secreting the hormone which stimulates blood production in the bones. I must always stay alert and maintain this balance in the best way; if you start losing blood, for instance, I must increase the hormone and accelerate blood production.

Yes Peter, I’ve told you about a few of my basic duties, but haven’t told you about how wonderfully designed I am. I am a bean-shaped organ and a single kidney like me weighs 130-160 grams on average. We are approximately 10 grams lighter in female bodies. I am surrounded by a soft but protective membrane. I need 35 grams of daily oxygen supply to survive and I use 13 % of your total body energy.

As an army is made up of individual soldiers, I am like a complex army, and a single soldier of mine is called a “nephron,” which does the real job. Thus, you can see me as a body of nephrons. Millions of these nephrons are brought together to make up one kidney.

A single nephron is a thin tubular structure with closed ends, and its length is about 3-4 cm. So the total length of my nephrons is about 50 km. The cup-like sac at the beginning of a nephron is named the “Bowman’s capsule.” The main artery bringing blood to the kidneys branch into smaller units, and one road leads to every nephron. The knot of capillaries (glomerulus) inside this double-walled capsule is more complicated than any road map you might have seen. The total length of the capillaries is nearly 25 km. The unwelcome substances in the blood are passed to the capsule thanks to blood pressure, and they proceed through the tubule. The total surface area of my tubules is about 20 m2. Within five minutes the whole of your blood passes through us. That is to say, an average of 1.2 liters of blood per minute, and 1800 liters a day are filtered by my nephrons, leaving the toxic substances in me. As this amount of blood (nearly 400 times the normal amount in your body) pass through my tubules and return to the veins they leave behind an average of 180 liters of liquid in me. In this case, you could be supposed to throw out 180 liters of urine a day. However, if you really did that, you would neither be able to find a sufficient supply of water nor salt. Fortunately, Providence granted you the mechanism to absorb back nearly 178.5 liters of this filtered substance. This way, the thickened urine throws out the toxic nitrogen-containing byproducts together with a little amount of water. Therefore, I give you back the substances you need with an amount of 1.5 liters of liquid disposal a day. This reabsorbing is realized in what you call the Henle loop. The cells in the walls of my tubules have neither intellect, nor consciousness, nor any knowledge of physiology; in spite of this, they work as if they were perfectly aware of their duty to adjust the amounts and types the substances to be kept or released. To give you an idea, you can think about the huge dialysis machines your engineers design to fulfill the job my tiny tubules do. You decide which one of us is the perfect work of engineering.

A rich network of veins surround the Heinle loop and the reabsorbed substances are released into the bloodstream. The drops to be disposed of are collected and then passed to your bladder. When the liquid in your bladder amounts to a certain value it tightens the bladder walls. The muscles blocking the way out give way and the urine is disposed of. However, know that the bladder has the capacity to expand as large as 1.5 liters when you cannot find the proper time and place.

Peter, most people take for granted the blessings they enjoy. If you visit the nephrology service in a hospital and talk to the patients waiting to be dialyzed, you understand what I mean better. Do not forget that many people who suffer from kidney failure need that huge machine to filter the whole of their blood and they pray for a kidney suitable for transplantation to be found at once.

Incidentally, thinking of chronic kidney failure recalled various reasons which ruin me: long lasting infections, long-term use of certain medicine, different chemicals like ethylene and mercury, heavy loss of blood, high blood pressure, serious burns, and wrong blood transfers etc. In such cases I can receive irreparable damage.

Another issue which troubles me is the formation of kidney stones. The stones which form owing to failures in different metabolic processes really hurt. When excessive decrease of liquids or increases of salts in the body upset my sensitive balance, some dissolved substances remain, begin to collect, and form stones. These stones hinder urine flow and might cause infections. You may drink water abundantly to prevent these stones. Most importantly do not wait too much before going to the toilet. If you excuse me, I also strongly recommend you to urinate in sitting position; this helps emptying your bladder completely and reduces the risk of kidney stones.

I do my job properly until I lose 90 % of my working capacity. When a considerable part of me loses its capacity, the remaining good part boosts its activity to make up for the loss. When one of our twins are taken out with an operation, the other one does not complain at all; it grows a bit bigger and keeps working.

As the nature of honey depends on the nectars bees collect, the ingredients of the urine I produce depend on what’s in your body. Therefore, a urine analysis tells much in the case of illness. For example, I normally do not release valuable substances like glucose and protein in your blood into the urine, but return them to the bloodstream. As my friends cannot fulfill this function in diabetic patients, their urine analyses reveal glucose. As for medicines, I throw them out right away since they are alien substances to me.

Peter! You are young and healthy but be careful and do not get cold around the waist, otherwise I might trouble you. There’s a lot to tell you Peter, but I do not want to confuse you. Like any other organ, I do not like being taken for granted and I just wish for you to appreciate what a blessing I am. Let me note that my perfect cooperation with the rest of your body is another wonder in itself. Anyway, the urea in your blood is increasing, so I must go help my twin now. Goodbye Peter!

Irfan Yilmaz is a professor of biology at Dokuz Eylul University, Izmir.

The conservation of soil is also important. But as its value has not been properly appreciated until recently, soil has become seriously polluted with chemical substances which can hurt the living species in it. These poisonous chemical substances include cadmium, arsenic, chrome, and mercury at excessive levels, lead, nickel, molybdenum and fluorine at medium levels and boron, copper, manganese and zinc at low levels.

There are a number of sources of these substances which accumulate in subsoil. Tones of such substances are dispersed into the atmosphere as a result of the burning of fossil fuels, the casting of minerals and other industrial activities. Atmospheric processes cause these substances to disperse and mix with the soil first and penetrate into plants later; polluted water and soil consequently cause disastrous problems for construction, the environment, and health.

The level of borax which is available in soil, for instance, is becoming overwhelming due to the extensive use of detergents and fertilizers. Super phosphate, which is a kind of fertilizer, and limestone, which is found in soil, are generally composed of small quantities of cadmium, copper, manganese, nickel and zinc. Cadmium and chrome are utilized in producing metal coatings; cadmium is also used in battery production; and arsenic is utilized in cotton, tobacco and fruit plantations as an insect and weed killer. As products in which these substances are found have been increasingly used in recent years, these substances have been consumed by human beings in higher proportions in their daily air, water and food intakes.

Although presently a partial solution, a method of improving soil by the use of plants has recently been developed and introduced as a clean and permanent solution. Research conducted has proved that plants have important functions in cleaning chemically polluted soil, and significant scientific findings have been obtained about how plants survive in an environment replete with poisonous chemicals.

Plants: The volunteer soil cleaners

The use of plants to eliminate substances which are unfriendly to the environment or to diminish their negative effects on the environment is called “phytoremediation.” Cleaning polluted soil with techniques that necessitate engineering processes is a rather costly operation. On the other hand, certain plant species have been granted the ability to concentrate heavy metals such as zinc, cadmium and nickel, which they take up from the soil, in their stems, shoots and leaves. The parts of these plants containing the concentrations of heavy metals are collected, reduced in volume and are stored for future use.

Plants which are capable of storing metals in themselves are used for soil-cleaning purposes in the mining industry. Bio-mining is defined as obtaining minerals by way of growing plants in polluted or mineralized soils and then harvesting them as soon as they have concentrated a sufficient amount of minerals in their tissues. Plants are burned after being baled and their residual ashes are being sold as mineral ores. Zinc has been produced at a rate of 30–40 % from ashes of the plant thlaspi caerulescens which was grown in a plantation rich in zinc in Pennsylvania.

How plants are employed in soil cleaning

Lately, a number of research projects have initiated on the plant thlaspi caerulescens, which is seen as useful in terms of soil cleaning. Thlaspi is a member of the broccoli and cabbage family and it grows in soils containing high rates of zinc and cadmium. These plants develop wide root formations in soils containing heavy metals; they transfer these heavy metals via their hair-like roots first to their stems and later to other parts, and store those heavy metals in their leaves. Storers like thlaspi are a good model of the mechanism of metal-storing and even shed light onto the biological system which plays a role in this process. The biological composition of these plants has been enriched with genes so that they assume a role in increasing the solubility of heavy metals in soil, in the transfer of metals to their roots, and in producing proteins to play the intermediary in such transfers.

While a typical plant is equipped with a storage capacity of 100ppm (gr per ton) zinc and 1ppm cadmium, thlaspi is created with a storage capacity of up to 30,000 ppm of zinc and up to 1,500ppm of cadmium, without any signs of being poisoned, whereas an ordinary plant may be poisoned with a zinc level of only 1,000ppm or cadmium between 20 and 50ppm. What would it have meant for living beings which are nourished by plants, if all plants had been created with as high a storage capability for heavy metals as that of thlaspi?

It has been noted, while researching the zinc-storage mechanism of thlaspi, that certain parts of the plant have been stimulated for the purpose of transferring zinc. While in ordinary plants gene-decoding of proteins which are charged with zinc transfer is regulated according to their zinc contents, in thlaspi synthesizing of the carrier proteins continues until the zinc contents of its tissues reaches very high levels.

How radioactive cesium is cleaned

It has been found, as a result of research into soils polluted with radioactive cesium-134 and cesium-137, that the area polluted by cesium-137 is under the threat of radioactive pollution, even if the effects of pollution that it caused over the soil surface would be lessened. One of the most important reasons for this is that cesium-137 is a long-lasting radioactive isotope with a half-life of 32.2 years.

Phytoremediation is preferable to alternative cleaning methods, which cost much more due to high energy inputs. However, cesium, in the form it is found in soil, is not absorbed by most plants, and ammonium ions cause the dissolution of cesium-137 in soil.

However, amaranthus retroflexus, which is a member of the goose-foot plant family, has been found to be forty times more efficient than other plants tested in cleaning the soil of radioactive cesium. Thus, polluted lands are expected to be cleaned within fifteen years if this plant is grown and harvested two or three times annually.

A plant fed by arsenic

Arsenic is utilized in the production of agro-chemicals that are used to kill weeds and insects in the sub-soil. The fern named pteris vittata has been found to be created with the capacity to store arsenic. When this plant fern was discovered to contain two hundred times more arsenic than the surrounding soil, it was understood that it is fed by arsenic. This discovery is expected to open new horizons in cleaning the agricultural land, especially in industrial and mining areas.

How damage caused by aluminum can be decreased

Aluminum, which is one of the most abundantly available elements (among oxygen, silicon, iron, magnesium, sodium, potassium, aluminum and calcium) in the earth, is among the main components of clay in sub-soil. It does not pose a threat to plants when it has a basic or neuter pH value. However, Al+3 which is a kind of aluminum dissolvable in acidic soils, is poisonous to the extent that it threatens plant roots.

How some plant species, among which are wheat, corn and barley, can be cultivated in acidic soils in spite of high metal rates is being researched. Studies in this context are being conducted on arabidopsis thaliana (the mustard family) whose gene map is prepared and which constitutes a model. A mutated arabidopsis, for instance, has been discovered to have been equipped with the capacity to render aluminum harmless. If the genes which play their role in this process can be determined, then gene transplantation will be possible to increase the resistance of plants which are sensitive to aluminum, such as barley, and barley production will accordingly be increased.

All these facts clearly indicate that the earth is like a great and continuously working factory or a guest house continuously becoming full and empty. The pollution which is an inevitable result of the activities of living creatures is kept under control by micro organisms, plants and animals which are the mirror-bearers of Almighty God’s attribute, al-Quddus, “the All-Pure.” The relations between these living creatures and the universe have been so perfectly programmed that all of them beautifully perform their duties.

References

• Brady, N.C. The Nature and Properties of Soils, 1990, 10th Edition.
• http://www.agclassroom.org/teen/ars_pdf/9earth/2000/06phytoremedation.pdf
• Altunay, Bedirhan. “Biotechnology of the Environment,” 2006, Sizinti, No: 335, p.526–528.