Peri‑medical old news

{"translated_text":"Learn topology!\nFor assessing this news it is important that it presents not common jokes but actual news of operative surgery.\nThe human body is an object with a very complex topology. Recall how compartmentalized (divided into many compartments) a typical eukaryotic cell is! Cells are organized into tissues in a non‑trivial way, tissues into organs and organ systems. The most important characteristic of the organism as a whole is its structural plan – architectonics, the general principles of spatial arrangement of parts. Do you know how children are tormented in school biology, being forced to memorize that roundworms have a primary body cavity and annelids a secondary one? Yet even similarly organized organisms can be topologically quite different.\nDid you know that in males the body cavity is closed, while in females it is not? Oocytes fall from the ovary into the body cavity and then, via the fallopian tubes, reach the uterus, which is connected to the external environment. In our distant ancestors sperm traveled a similar route, but later male gametes obtained an independent tunnel and the body cavity became closed.\nHow to untangle the topological puzzle that is the human body? Computerization helps somewhat. At the University of Calgary a digital 4D model of the human body, called Caveman, has been created. Its fourth dimension is temporal; the model itself was prepared within the joint project with Sun Microsystems, Cave, for visualizing three‑dimensional environments. All details of the various “gears” of the human organism can be examined in a special pavilion with 3D glasses, and the installation’s size allows demonstration of any organs and sections far larger than life size. What is this for? For training doctors. For showing patients what is planned for them. For planning surgeries – both traditional ones with wide incisions for access to the operative field and modern, tissue‑sparing ones.\n[IMG_1]\nThe traditional surgery approach is simple: cut everything that hinders access to the target point and conveniently do the job. In the postoperative period the wounds will heal one way or another. Endoscopic surgery has reduced incisions thanks to microsurgical instruments. The next step is to abandon cutting the body’s coverings. This paradigm is called transluminal endoscopic surgery through natural orifices. It uses insertion of endoscopic tools through existing body openings – usually the mouth or vagina. The body cavity can be entered via a small internal puncture. In the case of a female organism, inserting an endoscope through the fallopian tubes would also be incorrect – the opening is small and there is a serious risk of damaging a vulnerable organ. Fortunately, internal punctures can heal faster than skin incisions. The new technology is already in use. For example, gallbladder removal through the vagina is performed in the USA and France. Indian surgeons have reported a series of appendectomies performed through the mouth!\nSuch operations are advantageous because of a short postoperative period, low pain level, low risk of wound infection and consequently no scars. There are also drawbacks: possible hidden internal bleeding, technical complexity, unpleasant taste in the patient’s mouth… And, of course, the need to study topology.\n\nMan – the measure of all things?\nScientists at the Pasteur Institute in France announced the discovery of a new analgesic six times more effective than morphine. The new substance, which prevents the breakdown of natural analgesics – enkephalins, has been named opiorphin. Fortunately, its structure is simple, and it is hoped that it will eventually be produced synthetically. Research on opiorphin has just begun, and only rats have so far been tested on it.\nThe most surprising aspect of this discovery is that opiorphin was not found in some exotic substance (for example, in a rare tropical plant delivered to the laboratory thanks to the wisdom of healers and the heroism of tropical researchers…) but in human saliva. And is this result really that astonishing? Probably few people have never heard of the healing properties of saliva. Everyone knows that a scratch or abrasion should be licked: it hurts less and heals faster. In fact, doctors recommend medicinal products containing antiseptics for such situations. They know best, of course. However, saliva contains not only sacraments‑producing bacteria that cause caries, but also natural antiseptics.\nThe mundane origin of this new miracle substance should not be surprising. Our body is an extremely complex system capable of self‑regulation over a wide range. What is strange that the most effective regulators are found within it rather than being sought in exotic sources? Rather, one should be amazed that foreign‑origin keys fit our own locks!\n\nCrocodile blood\nBlood transfusion not only saves countless lives but also creates many problems. By delivering oxygen to tissues, blood supports the function of all human organs. The ability of blood to transport oxygen is linked to the activity of the iron‑containing protein hemoglobin, located in red blood cells (erythrocytes). In essence, an erythrocyte is merely a cell remnant, as it lacks a nucleus that controls its metabolism. It is a hemoglobin‑filled machine designed for a limited lifespan. Unfortunately, the erythrocyte surface carries many immune and signaling molecules that determine blood group. Their incompatibility between donor and recipient is the cause of the aforementioned problems. Blood transmits many diseases, including HIV, hepatitis B and C. Natural blood is difficult to store, and its collection involves many logistical concerns.\nAll these difficulties could be avoided by creating a universal blood substitute. The potential market volume for such a product is billions of dollars per year. It would be wonderful if, instead of cellular blood, a hemoglobin solution could be used. Unfortunately, human erythrocytes chemically regulate oxygen binding and release. Free hemoglobin in blood is toxic to the kidneys.\nIn search of a solution, scientists have turned to other organisms. Crocodiles are especially interesting from this perspective – highly organized animals, the closest relatives of dinosaurs and birds. Already in the dinosaur era crocodiles adapted to long periods of ambush at the bottom of water bodies, awaiting unwary prey coming to drink. Crocodile blood can efficiently transport oxygen both at high concentrations (when the crocodile is on the surface and active) and at very low concentrations (when it lies on the bottom). In crocodiles, oxygen binding and release is regulated not by the erythrocyte itself but by the chemistry of surrounding tissues. Moreover, crocodile hemoglobin appears to be safe in a free state in blood.\nAustralian biologists have decoded the amino‑acid sequence of crocodile hemoglobin and the nucleotide sequence of its gene. Their idea is to use genetically modified bacteria to produce crocodile (or crocodile‑human hybrid) hemoglobin for use in blood substitutes. This promising concept may lead to artificial blood that can carry oxygen more efficiently than natural blood!\nHowever, even human‑to‑human transfusion faces ethical and religious objections. For example, Jehovah’s Witnesses oppose the procedure. Orthodox Jews believe that the soul of humans and animals resides in the blood (hence only meat from animals whose blood has been removed can be kosher). Now imagine a person whose veins carry crocodile blood produced by genetically modified bacteria!\n\nBeing deceived gladly\nWe are accustomed to thinking that the mentally ill are those whose psyche copes less well with the diverse tasks life presents. Steven Dakin and other staff of University College London discovered an unusual psychological phenomenon. Everyone knows various “tricky” images that provoke erroneous judgments based on optical (more precisely, mental, related to visual information processing) illusions. English psychologists proposed a task that healthy people cannot solve, but which is manageable for patients with schizophrenia. From a set of small circles placed on the periphery, one must select the circle that matches the central one in optical contrast (see figure). Schizophrenics may perform this task more easily because their brain does not compare the model circle with the large surrounding circle. In this case the task tests how the contextual information‑processing block works in the subject’s mind.\n[IMG_2]\nHow important is illusion recognition for mental health? One should look at the activity of our psyche from the standpoint of its purpose. All brain activity serves adaptation to a changing ecological and social environment. A successfully adapting person can be considered healthy, even if his psyche works differently from that of most citizens. If he “falls out” of the surrounding world and feels bad, something must change.\nThe same action can be neutral, offensive or friendly for us depending on the relational context and the person from whom it originates. Schizophrenics cannot correctly interpret context, become offended or frightened, suffer themselves and cause suffering to others. And you say – spotted circles…\n\nSoap instead of condoms\nA curious discovery was made by scientists at the University of California, San Francisco: it turns out that soap kills HIV (human immunodeficiency virus, the cause of AIDS). According to data published in the journal Antimicrobial Agents and Chemotherapy, a soap solution (1 g of soap per 200–400 ml of tap water) reduces viral concentration thirtyfold and also decreases the number of infected immune cells by 57–87 %.\nResearchers aimed to obtain a cheap yet effective AIDS prophylaxis, urgently needed in under‑developed countries. The clue was that soap solubilizes fats, and the viral envelope consists of lipids.\nNevertheless, a microbiologist would not be surprised by HIV’s vulnerability in a soap solution – viruses are generally rather unstable structures. Isolated HIV is destroyed by anything: light, ultrasound, various chemicals. The problem is not how to destroy an isolated virus, but how to act on it in the body without harming the person (for example, introducing soap into the bloodstream would, before disrupting viral lipid envelopes, bind essential host lipids, which would be worse than AIDS). As one of the authors, Jonathan Li, said: “Only laboratory studies have been conducted, and we do not yet know how it will work in reality.”\nThe experiments used Ivory soap, one of the cheapest and most widespread brands. Interesting whether television will soon start airing ads for soap that protects against AIDS.\n\nDoes your cat like hunting birds?\nIt is hard to imagine a more intimate relationship than that of a parasite and its host. Throughout evolution the parasite’s ability to overcome host defenses is honed to a fine art. But what does a parasite species achieve by exterminating its host species? Evolutionarily “old” infections usually run almost asymptomatically. The most frightening diseases, whose epidemics can wipe out large portions of the population, are most often caused by parasites that have jumped to new or atypical hosts.\nThe natural hosts of influenza, whose pandemics affect all humanity, are Asian water‑fowl. For them infection is usually asymptomatic. In bird populations, “ordinary” influenza viruses evolve and exchange structural blocks. The virus replicates in the bird’s intestine, is shed with feces and infects new hosts via contaminated water. New viral forms are transmitted relatively easily from birds to humans, causing the familiar epidemics.\nThe so‑called “bird flu” is close to “ordinary” flu but more tightly linked to birds. Its transmission from wild birds to humans usually requires “bridges” – species more susceptible to it (including domestic poultry, pigs and horses). In recent years highly active forms of bird flu have spread, sometimes transmitting directly from birds to humans. First discovered in Asia, the disease has reached Western Europe. It is especially dangerous for children, in whom it often proves fatal.\nMigratory Asian birds spread the new virus across a large part of our continent. The rarity of the disease is due to the virus’s current difficulty crossing the species barrier. In this context, the discovery by researchers at the Erasmus Medical Center (Rotterdam, Netherlands) that domestic cats can participate in the transmission of bird‑flu viruses is alarming. Cats become infected with bird flu and can transmit it to other cats (and possibly to humans). It is not excluded that viral spread in cats could lead to virus strains better adapted to mammalian hosts. Because of their interest in birds and proximity to humans, domestic pets are suitable candidates for a “bridge” of viral infection.\nSo what to do? Be more careful with cats, do not let them catch birds and hope for the best…\n\n* * *\n[IMG_3]\nIn the line of non‑alcoholic beer, nicotine‑free cigarettes, cholesterol‑free eggs and thornless roses, the addition is opium poppy without morphine. In Tasmania (where 40 % of the world’s pharmaceutical‑grade opium poppy harvest is grown) mutants have been found that do not produce morphine. In such poppies the morphine precursors – thebaine and oripavine – accumulate, from which, just as from narcotic raw material, analgesic drugs can be produced. However, neither heroin nor opium can be obtained from them. The mutant flower is easy to distinguish: its sap is red or orange, not white. Waiting for a toothless white shark?\n\nMimivirus: a new addition to our zoo\nThe reality surrounding us repeatedly proves more complex than the schemes we use to describe it. What are viruses (biological, not computer)? Particles of nucleic acid and protein that, upon entering a cell, hijack its synthetic systems for their own replication. In school biology they are somehow classified as living organisms, although they lack most characteristic features of life. Viruses vary greatly in complexity. There are also simpler infectious agents – viroids (consisting only of nucleic acid) and prions (single protein molecules). To call them organisms as well? Absurd.\nWhat is more complex than viruses? Between a complex virus and a simple bacterium there seemed to be a gulf. A bacterium is already a cell, a super‑complex system. Even the simplest bacteria (mycoplasmas, chlamydiae), having lost some cellular functions due to deep adaptation to parasitism, occupy a different level of complexity.\nIn 1992 British bacteriologists were searching for the habitat of Legionella – a water bacterium causing severe human disease, legionellosis. In a cooling tower they found amoebae infected with parasites resembling bacteria. By size (400 nm) these parasites corresponded to mycoplasmas. Further study showed they were giant viruses, named mimiviruses. Recently the genome sequences of these monsters have been published.\nThe main conclusion of the researchers is that the mimivirus is “alive”. Typical viruses have up to 300 genes; the mimivirus has 1 260, i.e., at the bacterial level (humans, for example, have about 20 000 genes, see p. 24). About 50 of these genes encode functions not typical for viruses and produce proteins responsible for the parasite’s own metabolism. Finally, 7 genes are common to the mimivirus and cellular organisms! Unlike other viruses, the mimivirus contains almost no “junk” DNA lacking functional information. It is a unique object – the only known organism whose genome is simultaneously recorded on DNA and RNA. The information keeper in most organisms is DNA, and in retroviruses (such as HIV, the AIDS agent) – RNA, which a special enzyme uses to reproduce DNA.\nThe discovery can be interpreted in two ways. Even if the mimivirus is a result of cellular simplification during evolution, it will require its own systematic category of the highest rank. But perhaps organisms like it were involved in the origin of cells, which is even more intriguing.\nAn important detail: in a special study antibodies corresponding to characteristic mimivirus proteins were found in humans. This is indirect evidence of the mysterious object’s ability to parasitize not only amoebae but also humans! What other interesting things can be found inside us?\n\nD. Shabanov. Learn topology! // Kompyutera, M., 2007. – No. 21 (689). – p. 13\nD. Shabanov. Man – the measure of all things? // Kompyutera, M., 2006. – No. 43 (663)\nD. Shabanov. Crocodile blood // Kompyutera, M., 2004. – No. 35 (559). – pp. 15–16\nD. Shabanov. Being deceived gladly // Kompyutera, M., 2005. – No. 43 (615)\nD. Impolitov, D. Shabanov. Soap instead of condoms // Kompyutera, M., 2004. – No. 22 (546). – pp. 17–18\nD. Shabanov. Does your cat like hunting birds? // Kompyutera, M., 2004. – No. 36 (560). – pp. 16–17\nD. Shabanov. Untitled (In the line of non‑alcoholic beer…) // Kompyutera, M., 2004. – No. 38 (562). – p. 12\nD. Shabanov. Mimivirus: a new addition to our zoo // Kompyutera, M., 2004. – No. 41 (565). – pp. 20–21"}