Selection and adaptation of microorganisms in waste treatment.
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Adaptation, Physiological↗
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Results for “conservation physiology”
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Some aspects on death in the cold and concomitant frostbites.
The most important risk factors and findings of acute accidental hypothermia and concomitant local frostbites are reviewed. Both external and internal risk factors are usually present when exposure to cold is leading to death. The external factors are alcohol and psychic drugs, too light a clothing for the circumstances and wetness. Important internal factors are leanness, physical exhaustion and traumas in young persons and illnesses and degeneration of physiological heat conserving and production responses at old age. The signs caused by cold on the body are variable. In immersion hypothermia cases there are almost no changes, since the death occurs rapidly, most frequently from drowning. On the victims of dry frost first degree congelations, showing up as purple oedematic skin areas or spots, can be observed on the face and extremities. Stress ulcerations or haemorrhages in the stomach mucosa develop in ca. 70% of dry hypothermia cases. In long lasting exposures to cool temperature haemorrhagic pancreatitis, lung oedema and myxomatous skin oedema have been the characteristic signs. Frostbites developing concomitantly with fatal hypothermia show only oedema and hyperaemia, but no blisters or inflammation in the skin, which are the most conspicious vital reactions of frostbites after thawing.
Autopsy↗
[The human residential ecology: problems and future prospects].
The article deals with the scientific as well as ecological-and-hygienic foundations of shaping the dwelling environment; it focuses on the real, total loads of the chemical, physical and biological factors experienced by the man under the conditions of the urban residential environment in Moscow. The risk factors, which are present in the residential environment, are investigated alongside with positive factors. A concept of the social-and-hygienic monitoring, which is to be a scientific basis for working out a comprehensive program of the optimization of the population habitation conditions and of ensuring the healthy life mode, is offered. This makes it possible to promote the preventive and current sanitary supervision over the structure and maintenance of living quarters and to ensure a new qualitative level for such supervision involving a quantitative assessment of the whole range of both positive and negative factors of the habitant environment; it is important for determining the housing quality and its safety for the population health.
Adaptation, Physiological↗
[Conservative surgery in gynecology; its physiological bases and results].
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Female↗
A method of lens extraction for the injection of liquid intraocular lenses.
A method for the injection of liquid intraocular lenses into the capsular bag would offer many benefits in the treatment of cataracts. The corneoscleral incision could be made even smaller, the lens diaphragm would be conserved more physiologically, and a method of therapy for presbyopia might eventually be possible. As a prerequisite, a method of endocapsular lens removal is needed. We have developed such a method for our experiments on the injection of liquid intraocular lenses in the enucleated pig eye. We use a bimanual technique through two opposing 1-mm corneoscleral incisions and two openings measuring 1 mm in diameter in the peripheral anterior capsule. By using curved needles and suction tips, we could remove the capsular contents completely. The injected material was polymerized in situ by exposure to blue light and resulted in an optically clear cast of the lens capsule of surprisingly good optical quality.
Animals↗
[The diabetic foot].
The rise in the mean age and the increase in diabetes have frawn the surgeon's attention to gangrene of the lower limb which requires a multidisciplinary approach (doctor, surgeon, prosthesis specialist). Contrary to the concept of high thigh amputation, the possibility of carrying out a lumbar sympathectomy has encouraged the idea of a more distal amputation with conservation of physiological joints and an early recovery of function thus enabling patients who would otherwise have been condemned to permanent invalidity to return to social life.
Diabetic Angiopathies↗
[Metabolic changes induced with salmon calcitonin in post-menopausal osteoporosis].
10 patients suffering from post-menopausal osteoporosis were subjected to venous infusion of salmon calcitonine at a dose of 100 U.M.R.C. Essential inital biochemical data were hypocalcaemia associated with plasma increase in AMPc and, in the late phase, an increase in urinary excretion of phosphate and AMPc. In addition to conserving its physiological properties in osteoporotic disease also, the hormone is thus able to provoke a secondary secretion of parathormone. The use of CT in the treatment of post-menopausal osteoporosis is therefore recommended not only because of its evident action on bone reabsorption processes, which usually predominate in this dysmetabolic disease of the skeleton, but also in the indirect secretion of parathyroid hormone which is capable of positively affecting synthesis of 1-25 (OH)2 D3 and intestinal calcic absorption.
Aged↗
Scoliosis in familial dysautonomia.
Scoliosis is an almost constant finding in patients with familial dysautonomia who survive their first few years. Spinal deformity is frequently progressive and can add a serious problem to the complicated disease with its already high morbidity and mortality. Because of the associated physiological disturbances, conservative treatment frequently does not control the problem and surgery by spine fusion is indicated. Our experience suggests that the operative should be performed relatively early, before the appearance of a major curvature.
Adolescent↗
Do mammals, birds, reptiles and fish have similar nitrogen conserving systems?
Comparative physiological studies are a powerful tool for revealing common animal adaptations. Amino acid catabolism produces ammonia which is detoxified through the synthesis of urea (mammals, some fish), uric acid (birds), or urea and uric acid (reptiles). In mammalian herbivores and omnivores, urea nitrogen is salvaged by a series of steps involving urea transfer into the intestine, microbial mediated urea hydrolysis with synthesis of amino acids utilizing the liberated ammonia and transfer of the amino acids back to the host. A similar series of steps occur in omnivorous/granivorous and herbivorous birds, although in this case urine, containing uric acid, is refluxed directly into the intestine where microbes degrade the uric acid and utilize the liberated ammonia for amino acid synthesis. These amino acids are transferred back to the host. In reptiles and ureotelic fish not all of these steps have been experimentally confirmed. Reptiles like birds, reflux urine into the intestine where it is exposed to the microflora. However, the capacity of these microbes to breakdown the uric acid and urea and utilize ammonia for amino acid synthesis has not been documented. Ureotelic fish transfer urea into the intestine where urease (presumably of bacterial origin) hydrolyzes the urea. However, the amino acid synthesizing capacity of the intestinal microflora has not been studied. The series of steps, as outlined, would define the prevailing nitrogen conservation system for herbivores and omnivores at least. However, it would appear that some animals, in particular the fruit-eating bat and perhaps the fruit-eating bird, may have evolved alternative, as yet uncharacterized, adaptations to a very limited nitrogen intake.
Ammonia↗
[Clinico-physiological characteristics of the effectiveness of conservative therapy in traumatic neuropathies].
The effect of electroneuromyostimulation (ENMS) combined with Nootropil administration for trauma neuropathies was assessed using clinical and physiological tests in 58 patients. The combined intervention considerably accelerated the restoration of motor and sensory functions after the reconstructive neurosurgery on the extremities. Sensory functions substantially improved in 78% of the patients receiving ENMS and Nootropil and in 23% of those receiving the conventional treatment. The ENMS plus Nootropil treatment has been found to have advantages as compared with the conventional one.
Adolescent↗
Bradycardia during human diving.
The bradycardial response to the diving reflex, which occurs in man and in diving animals, is thought to be a physiologically protective oxygen-conserving mechanism whereby the animal is kept alive during submergence. The physiology and nervous pathways are not yet fully understood, but several investigators have pointed out the potentially fatal outcome of an accentuated diving reflex. the CO2 content of the peripheral venous blood has been proved variable and unpredictable during the hyperventilation-breath-hold dive cycle in man. A group of 8 male divers (average age 34 years) was investigated during breathhold dives to 3,3 m in a swimming pool. Heart rates were recorded and compared at various stages during breath-hold and SCUBA (self-contained underwater breathing apparatus) dives, viz. when resting on the surface, breath-holding, hyperventilating and swimming underwater. Two divers performed extreme breathhold endurance tests lasting 135 seconds underwater. All divers had a tachycardia after hyperventilation and a bradycardia after breathhold diving, lasting 80-100 seconds. Extrasystoles were recorded during some of the breathhold dives. Prolonged submergence caused extreme bradycardia (24/min) with central cyanosis. Bradycardia during diving may be a physiological )2-conserving reflex or the start of a pathophysiological asphyxial response.
Adult↗
High sodium-low potassium environment and hypertension.
The high sodium-low potassium environment of civilized people, operating on a genetic substrate of susceptibility, is the cardinal factor in the genesis and perpetuation of "essential" hypertension. The noxious effects begin in childhood, when habits of excess salt consumption are acquired at the family table, and are perpetuated by continuing habit and by increasing use of convenience and snack foods with artificially high concentrations of sodium and low levels of potassium. Present methods of food preparation leach out the protective potassium. Extradietary sodium chloride is a condiment not a requirement. Some primitive populations clearly preferred potassium chloride to sodium chloride. Chronic expansion of extracellular fluid volume induced by excess salt consumption causes the central and peripheral circulatory regulatory mechanisms to work at cross purposes, resulting in increased arterial pressure. The protective effect of potassium is dramatic and easily demonstrable in animals and man but its mechanism is not known. It cannot be entirely a direct effect on blood pressure because rats protected with extra potassium against a moderately high salt intake live much longer than control rats but have the same elevated blood pressures. In hypertension with a demonstrable "cause," the high sodium-low potassium environment makes a bad matter worse. In nature, feral man and his forebears were not confronted with excessive sodium and deficient potassium; indeed, the reverse was the case. Evolution has provided powerful mechanisms for conserving sodium and eliminating potassium, but no efficient physiologic mechanisms for conserving potassium and eliminating excess sodium. Most laboratory animal "control" diets contain an amount of sodium that fully suppresses aldosterone secretion, and the same is true of the "average" diet of the American people. Inadequate attention to dietary sodium and potassium makes many studies in both animals and man of uncertain validity. Internally, essential hypertension is an exceedingly complex mosaic of physiologic interactions. Viewed from outside, it is a disorder for which genetic material sets the stage; excessive sodium precipitates it and perpetuates it. Extra salt makes all forms more rapidly progressive and accelerates the onset of terminal events; extra potassium is everywhere protective. When an entire population eats excessively of salt, hypertension will develop among those genetically susceptible, but epidemiologic studies of salt versus blood pressure will not show a relation of salt to hypertension. This is the saturation effect. Low sodium diets are therapeutically effective but generally regarded as an impossible or an unnecessary nuisance. Effective prevention programs must be instituted at as early an age as possible. The efficacy of a prophylactic/therapeutic low sodium-high potassium diet should be weighed against the uncertain hazards of a lifetime of pill taking.
Adolescent↗
Nitric oxide is consumed, rather than conserved, by reaction with oxyhemoglobin under physiological conditions.
Although irreversible reaction of NO with the oxyheme of hemoglobin (producing nitrate and methemoglobin) is extremely rapid, it has been proposed that, under normoxic conditions, NO binds preferentially to the minority deoxyheme to subsequently form S-nitrosohemoglobin (SNOHb). Thus, the primary reaction would be conservation, rather than consumption, of nitrogen oxide. Data supporting this conclusion were generated by using addition of a small volume of a concentrated aqueous solution of NO to a normoxic hemoglobin solution. Under these conditions, however, extremely rapid reactions can occur before mixing. We have thus compared bolus NO addition to NO generated homogeneously throughout solution by using NO donors, a more physiologically relevant condition. With bolus addition, multiple hemoglobin species are formed (as judged by visible spectroscopy) as well as both nitrite and nitrate. With donor, only nitrate and methemoglobin are formed, stoichiometric with the amount of NO liberated from the donor. Studies with increasing hemoglobin concentrations reveal that the nitrite-forming reaction (which may be NO autoxidation under these conditions) competes with reaction with hemoglobin. SNOHb formation is detectable with either bolus or donor; however, the amounts formed are much smaller than the amount of NO added (less than 1%). We conclude that the reaction of NO with hemoglobin under normoxic conditions results in consumption, rather than conservation, of NO.
Hemoglobins↗
Skin reactions after breast-conserving therapy and prediction of late complications using physiological functions.
BACKGROUND: The temperature of the skin remains elevated long after breast-conserving treatment with irradiation, perhaps because evaporative cooling is impaired. We investigated physiological changes of the irradiated skin and reevaluated the radiosensitivity of sweat glands on a functional basis to determine whether severe complications can be predicted. METHODS: Breast and axillary skin temperatures were measured with thermography and sweat production in response to local thermal stimuli was measured on the basis of changes in electrical skin resistance with a bridge circuit in 45 women before, during, and after breast irradiation for breast cancer. RESULTS: Breast and axillary skin temperatures were significantly increased after irradiation. In response to cutaneous thermal stimuli, the electric skin resistance of nonirradiated areas decreased significantly because of sweating, but that of irradiated areas was unchanged. CONCLUSION: Impairment of sweating may play an important role in skin damage after irradiation. Although glandular tissue is not usually radiosensitive, the results of our functional assessment suggest that sweat glands are more radiosensitive than expected.
Adult↗
Conserved P-loop GTPases of unknown function in bacteria: an emerging and vital ensemble in bacterial physiology.
Establishing the roles of conserved gene products in bacteria is of fundamental importance to our understanding of the core protein complement necessary to sustain cellular life. P-loop GTPases and related ATPases represent an abundant and remarkable group of proteins in bacteria that, in many cases, have evaded characterization. Here, efforts aimed at understanding the cellular function of a group of 8 conserved, poorly characterized genes encoding P-loop GTPases, era, obg, trmE, yjeQ, engA, yihA, hflX, ychF, and a related ATPase, yjeE, are reviewed in considerable detail. While concrete cellular roles remain elusive for all of these genes and considerable pleiotropy has plagued their study, experiments to date have frequently implicated the ribosome. In the case of era, obg, yjeQ, and engA, the evidence is most consistent with roles in ribosome biogenesis, though the prediction is necessarily putative. While the protein encoded in trmE clearly has a catalytic function in tRNA modification, the participation of its GTPase domain remains obscure, as do the functions of the remaining proteins. A full understanding of the cellular functions of all of these important proteins remains the goal of ongoing studies of cellular phenotype and protein biochemistry.
Bacteria↗
Mechanism and evolution of hypoxia-tolerance in humans.
To physiologists, the term 'adaptation' usually refers to any trait that is considered advantageous; evolutionary biologists require a more rigorous definition (restricting it to traits arising and maintained under selection). By their definition, many physiological traits may merely reflect inheritance passed on through lineage. In considering the evolution of tolerance to reduced oxygen availability, we examined the issue (of true adaptations versus simple inheritance) in pinnipeds (the two dominant groups, phocids and otariids, with varying diving capacities) and in human lineages exposed for varying generational periods to hypobaric hypoxia. Basic principles of the evolution of complex physiological systems first emerged from an analysis of the diving response. We then analyzed human responses to hypobaric hypoxia in three different lineages: lowlanders, Andean natives (Quechuas) and Himalayan natives (Sherpas). As in the pinniped example, we found 'conservative' and 'adaptable' physiological characters involved in human responses to hypoxia. Conservative characters are clearly dominant and are too numerous to outline in detail; three examples are haemoglobin oxygen-affinities, the organization of muscle into different fibre types and the brain's almost exclusive preference for glucose as a fuel. Most notably, we also found evidence for 'adaptable' characters at all levels of organization examined. At the whole-body level in Quechuas and Sherpas, we found (i) that maximum aerobic and anaerobic exercise capacities were down-regulated, (ii) that the acute effect of hypoxia (making up the energy deficit due to oxygen lack; i.e. the Pasteur effect) expected from lowlanders was blunted, and (iii) that acclimation effects were also attenuated. The biochemical behaviour of skeletal muscles was consistent with lowered reliance on glycolytic contributions to energy supply, thus improving the yield of ATP per mole of carbon fuel utilized. Heart adaptations also seemed to rely upon stoichiometric efficiency adjustments, improving the yield of ATP per mole of oxygen consumed (by using glucose in preference to fatty acids). Most of the biochemical and physiological adaptations we noted (both as acute and as acclimation responses) were similar in Sherpas and Quechuas. These two lineages have not shared a common ancestor for approximately one-third of the history of our species, so it is possible that their similar physiological traits arose independently as hypoxia defence adaptations in two different times and places in our history. As in the evolution of exquisite capacities for management of oxygen down to vanishingly low levels in diving animals, the evolution of human hypoxia-tolerance can be described in terms of how two (conservative versus adaptable) categories of physiological characters are assembled in different human lineages and how the assembly changes through generational time. More recent evidence indicating that our species evolved under 'colder, drier and higher' conditions suggests that these adaptations may represent the 'ancestral' physiological condition for humans.
Adaptation, Physiological↗
Physiological responses to intermittent methohexitone for conservative dentistry.
Intermittent methohexitone for conservative dentistry has been shown to cause clinically undetectable respiratory obstruction, depression of the laryngeal reflex, and arterial hypoxaemia. Because of the pronounced decrease in total peripheral resistance, the blood pressure was maintained only by large increases in cardiac output. Furthermore, the output of the heart could not increase when challenged by hypoxia.
Adolescent↗
Merriam's kangaroo rats (Dipodomys merriami) voluntarily select temperatures that conserve energy rather than water.
Desert endotherms such as Merriam's kangaroo rat (Dipodomys merriami) use both behavioral and physiological means to conserve energy and water. The energy and water needs of kangaroo rats are affected by their thermal environment. Animals that choose temperatures within their thermoneutral zone (TNZ) minimize energy expenditure but may impair water balance because the ratio of water loss to water gain is high. At temperatures below the TNZ, water balance may be improved because animals generate more oxidative water and reduce evaporative water loss; however, they must also increase energy expenditure to maintain a normal body temperature. Hence, it is not possible for kangaroo rats to choose thermal environments that simultaneously minimize energy expenditure and increase water conservation. I used a thermal gradient to test whether water stress, energy stress, simultaneous water and energy stress, or no water/energy stress affected the thermal environment selected by D. merriami. During the night (i.e., active phase), animals in all four treatments chose temperatures near the bottom of their TNZ. During the day (i.e., inactive phase), animals in all four treatments settled at temperatures near the top of their TNZ. Thus, kangaroo rats chose thermal environments that minimized energy requirements, not water requirements. Because kangaroo rats have evolved high water use efficiency, energy conservation may be more important than water conservation to the fitness of extant kangaroo rats.
Animals↗