Manganese blocks HIV replication; Lab finding points to potential new class of HIV treatments

Johns Hopkins scientists have found that simply increasing manganese in cells can halt HIV's unusual ability to process its genetic information backwards, providing a new way to target the process's key driver, an enzyme called reverse transcriptase.

By measuring DNA produced by a related reverse transcriptase in yeast, the Hopkins team discovered that higher than normal levels of manganese, caused by a defective gene, dramatically lowered the enzyme's activity. The scientists then proved that HIV's reverse transcriptase responds to manganese in the same way.

Hopkins graduate student Eric Bolton determined that the defective gene is PMR1, whose protein carries both manganese and calcium out of cells. Using special yeast developed by others at Hopkins, he discovered that manganese stops reverse transcriptase, the team reports in the April 26 issue of Molecular Cell.

"These results really point to a never-before-proposed way to try to stop HIV in its tracks -- that simply manipulating concentrations of a metal, manganese, can have a profound effect on reverse transcriptase," says Jef Boeke, Ph.D., professor of molecular biology and genetics at the school's Institute for Basic Biomedical Sciences. "We expect the human equivalent of PMR1 could be a good target for developing new drugs against HIV."

Retroviruses like HIV use reverse transcriptase to make copies of their DNA from RNA, the opposite of how genetic information is usually processed in cells. Each retrovirus has a distinct version of the enzyme, identical in function but different in form and sequence, says Boeke, also a professor of oncology.

The scientists found that each reverse transcriptase they studied has at least two places where manganese and the similar metal magnesium can "dock." Having these spots filled with the right metal is crucial for the enzyme's activity -- its ability to read a particular set of RNA, the scientists learned. When the metals' balance is out of whack, the enzyme doesn't work properly, they report.

"Most reverse transcriptases we studied prefer to bind magnesium. At the very least they were more active when magnesium was bound to them," says Boeke. "But a little extra manganese changes the activity of the enzyme."

Normally, charged magnesium ions outnumber those of manganese by the thousands inside cells. Having just three times more manganese than normal can cut the activity of HIV's reverse transcriptase in half, the scientists report, even though there's still much more magnesium.

HIV's ability to adapt and overcome drugs means that current treatments like AZT, which target reverse transcriptase directly, generally stop working over time. Using a combination of drugs helps block the virus on many fronts, but finding new drugs or a new class of drugs is needed to help keep the virus at bay. The new work suggests that targeting a cell's manganese transporter could be an effective way to stop HIV from replicating, without targeting HIV's reverse transcriptase directly.

"We've been working under the idea that studying reverse transcriptase in yeast may help improve understanding of retroviruses and lead to new ways to deal with HIV," says Boeke. "By studying yeast genetics we made an important discovery about how HIV works and have identified a target for a new class of anti-retroviral drug. It was completely unexpected, but very satisfying."

The yeast that were missing PMR1 appeared fine, suggesting that targeting the manganese transporter in humans may be relatively safe, the scientists suggest. It's not known whether targeting manganese levels will have a therapeutic benefit, but the mantra of HIV treatment is to reduce the number of copies of the virus.

The studies were funded by the National Institutes of Health. Albert Mildvan, M.D., professor of biological chemistry, is also an author of the report.

[link to www.eurekalert.org]




Lymph nodal prion replication and neuroinvasion in mice devoid of follicular dendritic cells

Prinz M, Montrasio F, Klein MA, Schwarz P, Priller J, Odermatt B, Pfeffer K, Aguzzi A. .

Proc Natl Acad Sci U S A. 2002 Jan 22;99(2):919-24.
Institute of Neuropathology, University Hospital of Zurich, Schmelzbergstrasse 12, CH-8091 Zurich, Switzerland.

Variant Creutzfeldt-Jakob disease and scrapie are typically initiated by extracerebral exposure to prions, and exhibit early prion accumulation in germinal centers. Follicular dendritic cells (FDCs), whose development and maintenance in germinal centers depends on tumor necrosis factor (TNF) and lymphotoxin (LT) signaling, are thought to be indispensable for extraneural prion pathogenesis. Here, we administered prions intraperitoneally to mice deficient for TNF and LT signaling components. LT alpha(-/-), LT beta(-/-), LT betaR(-/-), and LT alpha(-/-) x TNFalpha(-/-) mice resisted infection and contained no infectivity in spleens and lymph nodes (when present). However, TNFR1(-/-), TNFR2(-/-), and some TNFalpha(-/-) mice developed scrapie similarly to wild-type mice. High prion titers were detected in lymph nodes, but not spleens, of TNFR1(-/-) and TNF alpha(-/-) mice despite absence of FDCs and germinal centers. Transfer of TNFR1(-/-) fetal liver cells into lethally irradiated Prnp(0/0) mice restored infectivity mainly in lymph nodes. Prion protein (PrP) colocalized with a minority of macrophages in tumor necrosis factor receptor (TNFR) 1(-/-) lymph nodes. Therefore, prion pathogenesis can be restricted to lymphoreticular subcompartments, and mature follicular dendritic cells are dispensable for this process. Macrophage subsets are plausible candidates for lymphoreticular prion pathogenesis and neuroinvasion in the absence of FDCs, and may represent a novel target for postexposure prophylaxis. [link to www.priondata.org]



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Spontaneous Regression of Advanced Cancer in Mice

Researchers at Wake Forest University School of Medicine, led by the Pathology Department's Zheng Cui (pictured below, left) and Mark Willingham (right), have bred a colony of mice that successfully fight off cancer.

Occasional, though rare, cases of spontaneous regression in human cancers have been seen and documented in the past, but no satisfactory explanations for this phenomenon have ever been put forward. While conducting a series of experiments with mouse sarcoma 180 (S180) cells, which form highly aggressive cancers in all normal mice, Dr. Cui and his colleagues happened upon a single mouse that surprised them with its ability to resist several forms of cancer, despite repeated injections of the sarcoma cells. Breeding the mouse produced offspring that also exhibited cancer resistance, suggesting a likely genetic link.

The cancer-fighting trait appeared to decline as the mice aged; six-week-old mice appeared to resist the cancer completely when injected with S180 cells, while the older mice were more likely to first develop cancer and only thereafter experience spontaneous regression. Further experiments showed that in these cases it was a massive infiltration of white blood cells that destroyed cancer cells in these mice without damaging normal, healthy cells.

Based on these results, Drs. Cui and Willingham and their colleagues suggest that a previously unknown immune response may be responsible for spontaneous regression. Click on the links below to learn more about this project.

[link to www.wfubmc.edu]
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AlFx: the useful tool in laboratory investigations, but potential danger for humans.

Anna Strunecká, Charles University Prague, Faculty of Sciences, Department of Physiology and Developmental Biology, Czech Republic.
Jirí Patocka, Military Medical Academy, Department of Toxicology, Hradec Kralove, Czech Republic.
Andreas Schuld, Parents of Fluoride Poisoned Children, Vancouver, Canada.

Summary
Aluminofluoride complexes (AlFx) have been widely used in laboratory investigations for stimulation of various guanine nucleotide-binding proteins. These complexes are able to simulate phosphate groups in many biochemical reactions. They are formed in water solutions containing fluoride and traces of aluminum. Reflecting on many studies, which utilize AlFx in laboratory investigations, a new view of fluoride and aluminum toxicity can be suggested. Moreover, many ecological studies bring evidence about the detrimental effects of fluoride and aluminum ions in humans. The hidden danger of their long-term action is not fully recognized at this point.

Introduction
Transfer of phosphate groups is the basic mechanism in the regulation of the activity of numerous enzymes, energy metabolism, cell signaling, and regulation of cell growth. Phosphate is an important component of phospholipids in the cell membranes. In view of the ubiquity of phosphate in cell metabolism, a phosphoryl transfer transition state analog might represent a useful tool for laboratory investigations, but also a strong potential danger for living organisms including humans. Such compound has been already found, described, and opted for molecule of the month March 1997 1,2,3. Moreover, the new phosphate analog has been used in experimental work in numerous laboratories.

Scientists need not buy this powerful compound through any catalog or drug store. Fluoride anions, generally introduced as NaF solutions, have long been known to influence the activity of various enzymes and the GTP binding proteins (G proteins). These proteins are part of a three-component transmembrane signaling system that serve as intermediaries carrying signals from numerous receptors to the cell interior. It has been later demonstrated that the effects primarily attributed to fluoride are caused by aluminofluoride complexes (AlFx) because experiments were performed in the presence of trace amounts of aluminum. This fact had at first been ignored because aluminum is a normal component of glass from which it is etched by a solution with fluoride 4.

However, the exact structure of the activatory complexes able to simulate PO43- group in many biochemical reactions, were disputed. AlFx (where x = 1-6) forms in aqueous solutions of fluoride and aluminum. The different coordination numbers of aluminum originate mainly from the difference of pH 3, 5. The bound AlFx occurs as AlF3 at pH 8.5 but as AlF4 at pH 4.5.

AlFx - phosphoryl transfer transition state analog
Analogies between a phosphate group and aluminofluoride complexes consist in atomic and molecular similarities. The fluorine atom has the same size and the same valence orbitals as oxygen. Of course, fluorine is more electronegative than oxygen and has greater capacity for forming hydrogen bonds. Aluminum is close to phosphorus, their valence electrons are in the same shell. An Al-F bond is the same length as a P-O bond in phosphate, i.e.1.5 to1.6 Å. Like phosphorus, aluminum has possible coordination numbers of 1 - 6, due to the possible hybridization of its outer shell 3p electrons with the 3d orbitals. AlFx are not permanent, equilibria exist between the various possible complexes, depend on the excess concentration of free F- ions and on the pH of the solution 1, 3, 5. These complexes can bind to proteins by hydrogen bonds to the fluorine atoms just as to oxygen atoms of a phosphate ion. So can arise an aluminofluoride analog of pyrophosphate, R-O-PO2-O-AlF3, which may be bound at the site for the (-phosphate. Thus, for instance, in a GTP-binding protein whose nucleotide site already contains a GDP, an aluminofluoride complex can form hydrogen bonds with the donor groups of the (-phosphate site and bind ionically to the terminal oxygen of the (-phosphate of the GDP. Enzyme-bound ADP or GDP could therefore form a complex with the AlFx that imitated ATP or GTP.

However, an important functional difference between a phosphate group and the structurally analogous AlFx complexes exists 1,6. In phosphate, oxygen is covalently bound to the phosphorus and does not exchange with oxygen from solvent. In AlFx, ionic bonds are formed between the electropositive aluminum and the highly electronegative fluorine. While the reaction of a bound phosphate compound with orthophosphate is endergonic and slow, the corresponding reaction with AlFx is rapid and spontaneous. AlFx bind ionically to the terminal oxygen of GDP (-phosphate. Enzyme-bound GDP or ADP could therefore form a complex with AlFx that imitates ATP or GTP in its effect on protein conformation. This effect often causes a structural change that locks the site and prevents the dissociation of the trisphosphate.

AlFx in laboratory studies
Low cost and availability of these fluorometallic complexes contributed probably to the fact that their use as a useful tool in laboratory studies of G proteins widely spread 1,7. The heterotrimeric G proteins mediate the transfer of information from receptor to effector molecules. These studies brought a great deal of knowledge about the involvement of G proteins in cell signaling. Numerous papers bring evidence that AlFx influence various functions and biochemical reactions of all cells and tissues of the animal or human organisms with powerful pharmacological efficacy. Fluoride in the presence of trace amounts of aluminum affects all blood elements, endothelial cells and blood circulation, the function of lymphocytes and cells of the immune system, bone cells, fibroblasts and keratinocytes, ion transport, calcium influx and mobilization, processes of neurotransmission, growth and differentiation of cells, protein phosphorylation, and cytoskeletal proteins 7. It is not surprising in respect to the role of G proteins in signal transduction. Physiological agonists of G protein-coupled receptors include neurotransmitters and hormones, such as dopamine, epinephrine, norepinephrine, serotonin, acetylcholine, glucagon, vasopressin, melatonin, TSH, neuropeptides, opioids, excitatory amino acids, prostanoids, purines, photons and odorants 8. It has been demonstrated that AlFx may clone or potentiate the action of numerous extracellular signals. The principle of amplification of the initial signal during its conversion into the functional response has been a widely accepted tenet in cell physiology. AlFx therefore affects the levels of second messenger molecules, including c AMP, phosphoinositide signaling system, and cytosolic calcium homeostasis. Biological signaling pathways interact with one another to form complex networks 9. The discoveries of receptor diversity, numerous G proteins, and phospholipase C families, broadens enormously the possibilities of interactions of signal transduction events. The question as to how cells manage to make the right responses at the right times is still disputed. The phosphate-analog models of AlFx action have been accepted for G-proteins but may be extended to all enzymes that bind phosphate or nucleoside-polyphosphate. AlFx mimicks a phosphoryl group being transferred. Phosphoryl transfer reactions are involved in processes such as energy transduction, regulation of cell growth, activation of metabolites, and cytoskeletal proteins assembly.

Evidence about the action of AlFx in humans
The interpretation of laboratory investigations using isolated animal and human cells or tissues on the intact human organism could be discussed. Nevertheless, many ecological and clinical studies bring evidence about the detrimental effects of synergistic action of fluoride and aluminum ions in humans.

Most of the ill effects caused by fluoride were first recognized among workers in aluminum factories, where fluoride and aluminum are present in high concentrations. The levels of fluoride in serum, urine, and hair of these workers are higher than in the control subjects 10. Osteoarthritis and related disorders in such workers have been reported since the 1930 s 11. Observation of industrial fluorosis (osteosclerosis) led to the use of fluoride as a treatment to increase bone mass in osteoporosis patients. Psychiatric disturbances were also reported in aluminum smelter workers 12 - 14. The study of persons living near an enamel factory reports a distinct decline in mental activity, poorer memory, inability to coordinate thoughts and reduced ability to write. Those living further away from the factory were less affected and had lower urinary fluoride content (14). Chronic effects of fluorides on the pituitary-thyroid gland system in industrial workers engaged in fluorine production showed also moderate functional changes 15.

Fluoride intoxication with multiple nonspecific symptoms has been observed in chronic hemodialysis patients 16. In some regions, the water used for the dialysate also contained a lot of aluminum. Some patients used aluminum-containing medications. Moreover, patients with renal failure cannot remove aluminum from the blood. Elevated aluminum levels have been also implicated as the cause of dialysis encephalopathy or dementia 17. Dialysis dementia can arise after three to seven years of hemodialysis treatment. Speech disorders precede dementia and convulsions.

Fluoride has been used in the prevention of tooth decay for over 50 years. While official medicine is convinced that the epidemiological evidence that fluoride protects against dental caries is overwhelming 18 many studies reporting and evaluating the risks and adverse effects of fluoride on human organism were published during the same period 19 - 21. Some of them demonstrate the positive correlation between the higher intake of fluoride and osteoarthritis, changes in bone structure, and various non- specific symptoms. Reduction of children intelligence 22, 23, various psychiatric symptoms in adults, such as memory impairment, and difficulties with concentration and thinking were reported 19 - 21. Elevated fluoride content was found in embryonic brain tissues obtained from required abortions in areas where fluorosis was prevalent. These studies showed poor differentiation of brain nerve cells and delayed brain development 24.

Understanding the role of phosphate and G proteins in cell signaling allows to accept the fact that fluoride in the environment, water, and food chains followed by aluminum, can evoke various and multiple pathological symptoms 19, 25. The endocrine glands such as the parathyroid gland, the thyroid, the pituitary gland, and the pineal gland, are extremely sensitive to fluoride (25, 26). Of particular importance relating to G protein activation is the ability of fluorides to clone the role of thyroid-stimulating-hormone (TSH). Fluoride is used in laboratory animals specifically to substitute for TSH. The synergistic action of thyroid on fluoride toxicity has been reported since 1940. Fluorides effects on thyroid hormone synthesis can be observed on many different levels. There is a direct dose-response relationship with iodine: the higher the fluoride intake - the lower the iodine in the system. The major areas of iodine deficiency are identical to endemic fluorosis areas. The comparison of fluoride toxicity symptoms and symptoms of thyroid disorders has been reviewed 25. The functional changes of the hypophysis-thyroid gland system caused by disorders of the regulatory chain and fluorine impact on thyroid hormones metabolism at the level of target cells were reported 15. Moreover, the melatonin concentrations were positively correlated with TSH levels in hypothyroidism, and negatively correlated with T3 in hyperthyroidism 27. Regarding the crucial role of the thyroid in regulation of growth, development, and metabolism of many tissues, AlFx might influence the proper function of the entire human body.

Chronic exposure of humans to AlFx begins in the foetus 21, 24. Every minute at least one child is dying due to excess fluoride exposure dressed up as iodine deficiency. High fluoride exposure appears to weaken mental function among children, as well as adults. In respect to the etiology of Alzheimer s disease, the long term action of AlFx also represents a serious and powerful risk factor for the development of this new threat of human civilization epidemy (28). AlFx may affect all pathological hallmarks of this disease: processes of neurotransmission, ( amyloid generation, plaque formation, metabolism of apolipoprotein E, protein tau phosphorylation, cytoskeletal protein organization, transport of ions, energy metabolism, and calcium homeostasis 29,30. In light of the published findings, the AlFx s harm to intelligence would not be neglected by responsible scientists and physicians. AlFx represent serious hidden danger for homeostasis, metabolism, growth, and differentiation of the living organism including humans.

Fluoride and aluminum in ecosystems
Aluminum, the metal of the earth's lithosphere, is everywhere: in water sources, in nourishment, in different food additives and also in air in the form of dust particles. Aluminum is present in all living organisms including human 31. It has, until relatively recently, existed in forms not generally available to living organisms, and was therefore regarded as non-toxic. With the appearance of acid rains and the use of aluminum in industry, there has been a dramatic increase in the amount of uncomplexed aluminum in ecosystems. The water supply industry uses aluminum salts to produce a less turbid drinking water. In the UK, concentrations of between 0.01 and 3.5 mg/l have been found in potable waters 32. Toxic effects of increased aluminum concentration have already been observed in some animal and plant species living in lakes with aluminum concentrations of between 0.1 and 0. 8 mg/l 31.

Fluoride comes from fluoridated water, from crops grown with fluoridated water, from medicines, dental products, pesticides, fertilizers, fuels. About 143, 000 tons are pumped yearly into drinking water supplies in the U.S.A. 500, 000 tons a year goes into fresh waters and the sea, 155, 000 tons of fluoride are released annually into America s air 21. Industrial fertilizers and pesticides increase the amount of this element in agricultural products and food sources 21, 33. Several studies reported a high content of fluoride and aluminum in all tested Chinese, Indian and herbal teas (34). A cup of green tea can contain up to 22 mg of fluoride, as much as 22 l of fluoridated water, a cup of black tea 17.25 mg. Tea is the second most-consumed beverage after water in the world. That the aluminum present in tea is indeed resorbed in the simultaneous presence of fluoride was demonstrated in healthy male volunteers after drinking equal volumes (1.2 l) of tea, coffee or tap water on separate days. In every case the amount of the urinary excreted aluminum increased on the day when tea was taken. The results indicated that tea consumption must be considered in any assessment of the total dietary intake of aluminum in human beings 35.

Reports of fluorosis popped up in the 1970's when phosphate fertilizer plants dramatically increased production. For more than one hundred years, Florida has been a major producer of superphosphate fertilizer. Residents have complained at different times of difficulty in breathing, sore throats, and various nonspecific health problems due to excessive emissions from phosphate fertilizer plants. Spills from toxic waste water ponds dump hundreds of millions of gallons of highly acidic water laced with toxic fluorides, into rivers and streams. People living near phosphate fertilizer plants are twice as likely to develop lung cancer and osteoblastic leukemia 36.

No one can predict what happens in the human body after a truly chronic exposure to an increased content of fluoride and aluminum in body fluids and in various tissues. The severity and the development of the symptoms depend on a person s age, genetic background, nutrition status, kidney function, and many other factors. The natural barrier systems for aluminum such as low absorption in the gastro-intestinal tract, and various physiological ligands, such as citrate, phosphate, and silicic acid, were efficient buffers preventing the increased intake of this metal in natural conditions. The population is now exposed to soluble aluminum, which is more bioavailable. The presence of fluoride caused more aluminum to cross the blood-brain barrier and be deposited in the brain of rat 37. This study compared behavior, body weight, plasma, and brain fluoride levels after NaF exposures during late gestation, at weaning or in adults. Rats exposed as adults displayed behavior-specific changes typical of cognitive deficits, whereas rats exposed prenatally had dispersed behaviors typical of hyperactivity. Aluminum-induced neural degeneration in rats is greatly enhanced when the animals were fed low doses of fluoride 38.

Conclusions
The discovery of AlFx as a new class of phosphate analog brought numerous demonstrations of their powerful pharmacological efficacy. It is not surprising in respect to the role of G proteins in signal transduction. G proteins take part in an enormous variety of biological signaling systems, helping control almost all important life processes 39. It might seem difficult to decide if numerous laboratory experiments demonstrate a potential toxicological risk of fluoride and aluminum for the human population. The origins of many human diseases are in the functioning (and malfunctioning) of signaling components 9. Pharmacologists estimate that up to 60% of all medicines used today exert their effects through G protein signaling pathways (39). However, it is evident that AlFx is a molecule giving the false information amplified by processes of signal transmission.

The understanding of mechanism of action of these fluorometallic complexes could allow us to explain numerous observations about the effects of increased amount of fluoride and aluminum in the environment, drinks, and food. Fluoridation of public water treated with aluminum salts together with the wide use of fluoride and aluminum in medicine, industry, and agriculture, started the era of supplementation of human bodies with these ions as never before in the history of human race. Science has already accumulated evidence about their detrimental effects on the living organism. It seems that scientists still need more significant data to be sure about the causal relationship between the action of AlFx and disturbances of human health. However, numerous published reports bring us at least strong warning.

Chronic exposure of humans to AlFx begins during the first trimester in the womb. It is evident that children are at highest risk. It therefore follows that the sources of fluoride available to children must get addressed first, prioritizing on sources with highest content. For many this is not only water. For some it is fluoride in formula and prepared cereals, for others it is exposure to coal smoke during cooking. For others yet it is close vicinity to power plants with high fluoride emissions, or exposure to other fluoride-emitting industries. Then there are fruit juices and iced tea products, the first beverages introduced to toddlers, as well as toothpaste and other dental products. Vaccines, allergy skin tests, 25% human serum albumin, baby skin creams, baby diaper wipes, and antacids, which are frequently given to infants, are extremely high in aluminum. For adults, the accumulation continues from suntan lotion, cookware, aluminum cans and skin moisturizers. Such items as deodorants, vaginal douches and baby wipe not only have high aluminum content, but are applied to areas wherethere is far greater tendency to absorption through the skin.

The increasing content of fluorides and aluminum in food chains has raised the possibility that the near future will supply us with much more data about the danger of AlFx for humans, if it has not already done so. How long shall we wait to obtain evidence about the destructive actions of AlFx on the human race? How many subjects including ourselves, our children and our friends, shall we need for an overwhelming study?

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Information about the authors:
Anna Strunecká, Professor of Physiology, Charles University, Faculty of Sciences, Department of Physiology and Developmental Biology, Vinieckná 7, 128 00 Prague, Czech Republic.
Email: [email protected]
Faculty of Sciences, biology and chemistry, graduated in 1966, Ph.D. in normal and pathological physiology 197O, DSc in physiology 1988 Charles University, Professor of physiology 1988.
1981 - 199O Head of the Department of Physiology, Faculty of Sciences, Charles University.
pa: New York Academy of Science, International Union of Physiological Science, International Union of Biochemical Science. Her previous research was focused on the role of phospholipids, phosphoinositides, and calcium ions in the regulation of cell metabolism. She addressed her work to the implications in the development of pathological states of cells in blood diseases, schizophrenia, and Alzheimer s disease. The interactions of phosphoinositide signaling system with cytoskeletal proteins in red blood cells and the effect of aluminofluoride complexes were studied. In the past research the insect flight muscle, rat hepatocytes, human red blood cells, and platelets were used. She has published more than 15O scientific papers, four textbooks, and numerous articles in the lay press. She has 3O years experience teaching biologists, biochemists, and biophysicists. Her biography is included in, e.g., Who s Who of Women, Who s Who in Science in Europe, Who s Who of Professional and Business Women, etc. She is the Associate Editor of the News in Physiological Sciences and a member of the American Biographical Institute s Research Board of Advisors.

Jirí Patocka, Professor of toxicology, Department of Toxicology, Military Academy, Vimkova 870, 500 01 Hradec Králové, Czech Republic email: [email protected]
Faculty of Sciences, chemistry and physics, graduated in 1962, PhD in biochemistry 1974, DSc in toxicology 1992. Head research worker and Professor of toxicology at the Department of Toxicology, Military Academy, Hradec Králové. Member of the Czech Chemical Society, Czech Society for Biochemistry and Molecular Biology, Czech histo- and Cytochemical Society, Czech Society of Industrial Toxicology, Czech Society of Biological Psychiatry, Czech Psychopharmacological Society, The European Peptide Society and IBRO. He has published more than 250 scientific papers and presented more than 200 lectures and posters on scientific meetings. Co-autor of 8 books and/or textbooks. Almost 400 citations to SCI. His scientific work focuses on the biochemical mechanisms of toxic action of different biologically active compounds, mainly on inhibition of cholinesterases, include their application as Alzheimer s disease drugs and on the function of centrally active anticholinesterases and different peptides in teaching and memory processes.

Andreas Schuld is head of Parents of Fluoride Poisoned Children, an organization of parents whose children have been poisoned by excessive fluoride ingestion. The group includes educators, artists, scientists, journalists and authors, lawyers, researchers and nutritionists. It is active in worldwide efforts to have the toxicity of fluoride properly assessed. PFPC, 78 Malta Place,Vancouver, B.C.V5M-4C4, CANADA email: [email protected]

[link to members.aol.com]