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[Prostaglandins - selected clinical problems].
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[Specific dynamic action of food, the intestinal hormonal system and the theory of adequate nutrition].
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Prostaglandins; their biological and pharmacological role.
The biological and pharmacological roles of prostaglandin system are reviewed. The most recent and important finding is the isolation and characterization of endoperoxides, thromboxanes and prostacyclin. In many respect they seem to be even more effective than the original prostaglandins and could explain many actions previously attributed to prostaglandins. Prostaglandins, endoperoxides, thromboxanes, and prostacyclin seem to have important physiological and pathophysiological roles, e.g. in the cardiovascular, gastro-intestinal and reproductive systems, the skin, and the central nervous system, as well as in inflammatory, immunological and metabolic reactions. Thus, prostaglandin-like substances, their analogues, prostaglandin antagonists, and the drugs that affect prostaglandin synthesis present good prospects for the treatment of many diseases affecting these systems. The mode of action of most anti-inflammatory and analgesic drugs can be explained by actions on the prostaglandin system. New potent and selective regulators of the prostaglandin system are being investigated and more indications are being found for using existing drugs. Although the field is generally promising, there are many contradictory findings. This calls for a cautious interpretation of the many interesting observations.
[Prostaglandins. Various clinical, physiological and chemical aspects].
The prostaglandins (PTGs) are compounds derived of the essential lipids of diet. The name was received by isolation of the prostate, however, subsequent investigations demonstrate its existence in all tissues investigated, in every species of animals studied and in the mariner choral Plexaura homamalla, that is important fountain of PTGs for investigation. For its localization, action's mechanisms and diverse effects in apparatus and systems they promise to be potent therapeutic arms in diverse diseases. The literature relationed to PTGs is extense, there exist excellent reviews about it.
Gastrointestinal microflora in mammalian nutrition.
A mammal is a complex organism consisting of eukaryotic animal cells and eukaryotic and prokaryotic microbial cells. Most of the microorganisms reside in communities in the gastrointestinal tract. These gastrointestinal microfloras are known to serve nutritional functions in ruminants, pseudoruminants, and monogastric mammals with only modest or no foregut fermentations but with extensive hindgut fermentations in blind cecal pouches. In adult animals, the microflora hydrolyzes exogenous (dietary) and endogenous polymers, and provides the adult with all or at least a significant proportion of its carbon, energy, vitamins, and macromolecular building blocks. The flora also functions as a conservator of nitrogen that would otherwise be excreted as urea. In exchange, the flora competes directly with the host tissues for nutrients ingested in the diet, and also competes indirectly by somewhat repressing the absorptive capacities of the animal tissues. When the synergism is in balance, the animal tissues and the microflora operate in harmony for the health and nutritional welfare of the host as a whole. The system may be unbalanced by antibacterial drugs that destroy the microflora and by diseases of the animal tissues that destroy the controls regulating where indigenous communities localize in the tract, their microbial composition, and their biochemical activities. At such times, the nutrition of the animal tissues can be adversely affected to the extreme. Humans living in developed and developing countries have extensive microfloras in their hindguts. Humans living in developing countries may also have extensive microfloras in their small bowels. Those floras may function in nutrition of the animal tissues of man much the same as do floras in similar locations in the gastrointestinal tracts of mammals other than man. However, animals of some species other than human gain much of the nutritional benefit from their microflora through the practice of coprophagy. Since adult humans do not normally practice coprophagy, any nutritional benefit from the microflora depends upon the capacity of the bowel mucosa, principally that of the large bowel, to absorb bacterial products, e.g. short-chain volatile fatty acids. Such absorption undoubtedly occurs, but is surely not a major source of carbon and energy for the animal tissues of man.
Bacterial contributions to mammalian gut development.
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5-HT4 receptor ligands: applications and new prospects.
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Associations and physiological interactions of indigenous microorganisms and gastrointestinal epithelia.
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The emerging multifaceted roles of nitric oxide.
Nitric oxide (NO) is a highly reactive free radical with a multitude of organ specific regulatory functions. Since 1985, NO has been the subject of numerous research efforts and as a result, has been found to play a major role in the cardiovascular, pulmonary, gastrointestinal, immune, and central nervous systems. In addition, deranged NO synthesis is the basis for a number of pathophysiologic states, such as atherosclerosis, pulmonary hypertension, pyloric stenosis, and the hypertension associated with renal failure. Traditional NO donors such as sodium nitroprusside and new pharmacologic NO adducts such as S-nitrosothiols may serve as exogenous sources of NO for the treatment of NO-deficient pathologic states. This review is an attempt to acquaint the surgical community with the fundamentals of NO biochemistry and physiology. Increased knowledge of its functions in normal homeostasis and pathologic states will enable physicians to better understand these disease processes and utilize new pharmacologic therapies.
Physiological adaptations during pregnancy.
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Effect of diet on mucin kinetics and composition: nutrition and health implications.
The mucus gel covering the gut epithelium is in dynamic balance between synthesis and secretion of mucin from goblet cells and proteolytic and physical erosion that releases mucin into the lumen. In the lumen, mucin is partially protected from proteolysis by carbohydrate chains, and it contributes to endogenous protein reaching the ileum. Dietary components modulate the contribution of mucin to endogenous protein components and their qualitative composition. In addition, mucin plays a key role in gastrointestinal protection in association with the microflora. In this review, we will attempt to evaluate the consequences of dietary manipulation of mucin on gut health.
Nitric oxide: a molecule of the millennium.
Recognition of Nitric oxide (NO) as the chemical entity of endothelium-derived relaxing factor (EDRF) has renewed the interest of the scientific community in the last decade. The outcome of research the world over is that the dreaded environmental pollutant is found to be a fundamental physiological mediator and effector. NO is synthesized endogenously by enzymes nitric oxide synthase (NOS) in specialized tissues from its precursor L-arginine. The L-arginine-NO biosynthetic pathway is involved in physiological processes such as vasodilation, memory, neuroprotection, peristalsis, penile erection, immune defense, various endocrine and exocrine secretions in various systems such as cardiovascular, CNS, reproductive and immune system. Small quantities of NO produced by constitutive enzymes mediate these physiological effects. The expression of inducible enzyme or overstimulation of constitutive enzymes leading to production of large quantities of NO is implicated in the cytotoxic effects observed in various disorders like AIDS, cancer, Alzheimer's, arthritis etc. In conclusion, NO is a 'double edged sword' and the challenge before the scientific community is to develop strategies for using it to our advantage.
[Hygienic evaluation of the effect of coffee on the body (review of the literature)].
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The physiology of aging.
A knowledge of the physiology of aging is necessary in understanding the medical problems of the elderly. Far-reaching effects results from such diverse changes as increased density and decreased water content of connective tissue, reduced estrogen production, reduced respiratory ciliary function, diminished efficiency of the pulmonary macrophages and decreases in brain and renal mass.
[Physiology of extradural analgesia].
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The medical examination of commercial divers.
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[Cumulative effects of cecectomy and the axenic state on apparent digestive utilization of rations and fatty acids in rats].
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