Gene/Protein Disease Symptom Drug Enzyme Compound
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 28,634 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the effects of sublobar atelectasis on regional blood flow in anesthetized paralyzed pigs. Following the washout of nitrogen from the lung with oxygen, a sublobar airway was obstructed and a peripheral segment of lung allowed to collapse. Blood flow to the atelectatic region fell from a control of 140.0 +/- 20.5 to 16.6 +/- 2.9 ml/(min . g). Basilar regions that became atelectatic spontaneously during the course of the studies had similar decreases in blood flow. Inflation of the surrounding lung by the application of positive end-expiratory pressure failed to increase blood flow and vascular conductance within the atelectatic regions. These results indicate that mechanical and hypoxic effects on vessels perfusing sublobar atelectatic regions limit the effects of interdependence from the surrounding lung. Furthermore, with inflation of the surrounding lung, increases in pulmonary shunting of blood are small.
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PMID:Sublobar atelectasis and regional pulmonary blood flow. 39 42

Intramuscular nitrogen tensions in Tursiops truncatus after a schedule of repetitive ocean dives suggest a lung collapse depth of about 70 meters and suggest that intramuscular circulation is maintained during unrestrained diving in the open ocean. Therefore, the bottle-nosed dolphin is not protected by lung collapse from the decompression hazards of dives to depths shallower than 70 meters.
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PMID:Dolphin lung collapse and intramuscular circulation during free diving: evidence from nitrogen washout. 50 1

The effect of ventilation on movement of surfactant in airways was studied in rat lungs. Male albino rats were anesthetized and sacrificed by exsanguination. The trachea was cannulated and the diaphragm opened to allow the lungs to collapse. The lungs were left in chest and kept at minimal volume, or at constant inflation with air, or were ventilated with air, nitrogen or oxygen. At the end of 3 hr the extrapulmonary airways (EPA), i.e. trachea and bronchi, were separated from the lungs and flushed with 40 ml isotonic saline. The surface tension and lecithin content of the saline wash was then measured. The surface activity and lecithin content of the EPA wash did not change if the lungs were kept at minimal volume or at constant inflation, but increased following ventilation. This increase was directly related to the duration of ventilation and to the tidal volume and inversely related to the end-expiratory pressure. It was independent of O2 concentration of the gas used for ventilation. The results suggest that ventilation enhances the movement of surfactant in airways and that positive end-expiratory pressure prevents this effect of ventilation.
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PMID:Effect of ventilation on movement of surfactant in airways. 98 9

Four species of Phocidae, or true seals, inhabit the waters surrounding the Antarctic continent. These animals are thought to have different diving capabilities. The Weddell seal, Leptonychotes weddelli, is known to be capable of attaining depths up to 600 meters. The respiratiory system of the Weddell seal shows the usual adaptations to an aquatic environment characteristic of other marine. These include lungs that undergo compression acollapse at depths greater than 70 meters; hyaline cartilage in the tracheo-bronchial tree as far as the terminal bronchioles; and large amounts of smooth muscle surrounding the distal-most bronchioles. The collapsible lungs provide a mechanism by which air is forced from the alveoli adjacent to the pulmonary capillary beds thereby preventing the absorption of nitrogen gas into the bloodsteam. The presence of hyaline cartilage throughout most of the tracheo-bronchial tree increases the effective dead air space that accommodates most of the air forced from the collapsed lungs. The smooth muscle surrounding the respiratory bronchioles prevents their collapse while under the pressures of a deep dive. Collapse of the respiratory bronchioles not supported by cartilage would trap air in the lung alveoli during a dive. In addition, large- sac-like "diverticulae" are found in the submucosa throughout the tracheo-bronchial tree. These diverticulae, which open directly into the lumen of the tree, appear to be modified glands whose cells, in most cases, do not appear to be specialized for secretory function. They are most numerous in the more distal bronchi and terminal bronchioles where they are situated on both the luminal and adventitial sides of the hyaline cartilage supporting the walls of the air passages. Diverticulae are not found in the respiratory bronchioles or in the respiratory portion of the lungs.
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PMID:A gross and microscopic study of the respiratory anatomy of the Antarctic Weddell seal, Leptonychotes weddelli. 118 90

Over an eight-year peroid at NCBH, 33 patients were operated for ruptured abdominal aortic aneurysm. Factors associated with an increased mortality included preoperative blood urea nitrogen levels of more than 20 mg per cent, severe preoperative hypotension, duration of symptoms of less than 24 hours, free peritoneal rupture and blood transfusions of greater than 19 units. Preoperative hypotension was the most selective preoperative prognostic parameter. From a review of this and other reported series, it was concluded that reduced mortality from ruptured abdominal aortic aneurysm can best be achieved by prompt diagnosis followed by surgical treatment before cardiovascular collapse can occur.
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PMID:Ruptured abdominal aortic aneurysms: review of 33 cases treated surgically and discussion of prognostic indicators. 126 83

Administration of 2,3,5-(triglutathion-S-yl)hydroquinone [2,3,5-(triGSyl)HQ] to rats causes severe renal proximal tubular necrosis. Although the cellular target(s) for 2,3,5-(triGSyl)HQ is not known, substantial evidence implicates mitochondria as the primary cellular target for aliphatic S-conjugates. To determine whether mitochondria are targets for 2,3,5-(triGSyl)HQ, the in vivo and in vitro effects of this conjugate on rat renal mitochondria (RRM) were investigated. In vitro exposure of RRM to 2,3,5-(triGSyl)HQ inhibited site I-supported respiration to a much greater extent than site II-supported respiration. Inhibition of mitochondrial function, as manifested by decreases in the respiratory control ratios, were a consequence of significant elevations in state 4 respiration. Inhibition of constitutive gamma-GT activity with AT-125 had no effect on the ability of 2,3,5-(triGSyl)HQ to decrease mitochondrial function. The effects of 2,3,5-(triGSyl)HQ on mitochondrial function in vivo were subsequently assessed. Shortly (0.5-2.0 hr) following administration of 2,3,5-(triGSyl)HQ (20 mumol/kg, iv) to rats, a significant elevation of state 4 respiration was observed. Thereafter (4-16 hr) state 4 respiration returned to control values and state 3 respiration became significantly depressed. A total collapse in RRM function occurred by 24 hr. The effects of 2,3,5-(triGSyl)HQ on state 4 respiration preceded significant elevations in blood urea nitrogen, which occurred at 8 hr. However, pretreatment of animals with probenecid, an inhibitor of organic anion transport, caused a significant decrease in the 2,3,5-(triGSyl)HQ-mediated elevations in state 4 respiration at 1 hr, without preventing the subsequent development of renal necrosis. In contrast, AT-125, which protected animals from 2,3,5-(triGSyl)HQ-mediated nephrotoxicity, had no effect on the early (1 hr) elevations in state 4 respiration but did prevent the later (8 hr) decreases in state 3 respiration. The data suggest that the early elevation in state 4 respiration observed in vivo is unlikely to contribute to 2,3,5-(triGSyl)HQ-mediated nephrotoxicity. The relationship between the decrease in state 3 respiration seen at later time points and the subsequent development of toxicity require further study before a cause and effect relationship can be determined.
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PMID:The effects of 2,3,5-(triglutathion-S-yl)hydroquinone on renal mitochondrial respiratory function in vivo and in vitro: possible role in cytotoxicity. 136 89

One of the most important nutritional goals amongst athletes is to maintain adequate energy and fluid balance, since these are subject to relatively rapid changes and are directly related to performance and health. This may especially be the case when exercise intensity is high. Furthermore, when due to exercise and environmental stress food and fluid intake become depressed. In such conditions there may be a dramatic increase in the utilization of carbohydrate (CHO), fluid, and in some instances protein. These increased requirements may then not be covered. Insufficient replacement of CHO may lead to hypoglycemia, altered protein metabolism, central fatigue and exhaustion. Large sweat losses may pose a risk to health by inducing severe dehydration, impaired blood circulation and heat transfer, leading to heat exhaustion and collapse. Inadequate CHO and protein intake leads to a negative nitrogen balance, which over the long term will lead to a loss of muscle mass. In the scope of this presentation we will refer to the most important nutritional factors which are known to affect performance over a short term, at sea level and altitude.
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PMID:Nutritional aspects of health and performance at lowland and altitude. 148 43

To evaluate the organ specificity of pancreatic phospholipase A2 (PLA2) and the diagnostic value of the elevation of serum PLA2 levels in patients with serious diseases not involving the pancreas, we studied the organ distribution of PLA2 in autopsy specimens and serum level of PLA2 in patients who required admission to an intensive care unit (ICU). PLA2 was measured by a specific radioimmunoassay (RIA), using monoclonal antibody against human pancreatic PLA2. Organ distribution of PLA2 revealed that the pancreas showed a much higher content of pancreatic PLA2 immunoreactivity than any other organ. An abnormally high value of serum PLA2 was observed in 18 of 30 patients (60%) at ICU. Both serum PLA2 and pancreatic isoamylase were elevated in 11 patients (37%). Of 11 patients with hyperphospholipasemia and hyperamylasemia, serum creatinine was elevated in five patients and blood urea nitrogen in nine patients. Serum PLA2 levels did not always rise comparably to serum creatinine and blood urea nitrogen levels. Serum PLA2 values showed the best correlation with serum lactate dehydrogenase levels among routine blood-chemistry tests. The elevation of serum PLA2 was ascribable to renal dysfunction or ischemic pancreatic damage secondary to circulatory collapse with multiple organ failure.
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PMID:Elevation of serum phospholipase A2 in patients at an intensive care unit. 178 39

A homologous series of chiral (R) ether-amide phosphonolipid analogs of naturally occurring (R) glycerophospholipids were synthesized and characterized for their interfacial behaviors. The phosphonolipids possess isoteric ether, amide, and phosphonate functions at positions corresponding to the sn-1, sn-2, and sn-3 ester functions, respectively, of naturally occurring glycerophospholipids. All compounds were synthesized with disaturated C16:0 alkyl/acyl moieties to give structural analogy with dipalmitoyl phosphatidylcholine (DPPC), the major glycerophospholipid component of lung surfactant. Further substitutions at the headgroup nitrogen were also used to generate differences in headgroup size and polarity in the synthetic compounds. The surface activity of the ether-amide phospholipids was investigated in terms of adsorption to the air-water interface, together with studies of dynamic respreading after monolayer collapse and surface tension lowering in dynamically compressed spread films and dispersions. Results showed that several ether-amide phosphonolipids had more rapid adsorption and improved dynamic respreading behavior compared to DPPC, plus the ability to lower surface tension into the range of less than 1 to 4 mN/m in spread films and in dispersions under dynamic conditions. In combination with a series of diether phosphonolipids synthetized in a companion study [1], these ether-amide compounds are useful in the development of molecular structure-surface activity correlates for lung surfactant-related materials, and should assist in investigating the specificity of interactions between phospholipids and other pulmonary biological molecules.
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PMID:Chemical synthesis and surface activity of lung surfactant phospholipid analogs. III. Chiral N-substituted ether-amide phosphonolipids. 193 96

Effects of betaxolol, a cardioselective beta-adrenoceptor antagonist, on blood pressure and hypertensive complications in stroke-prone spontaneously hypertensive rats (SHRSP) were investigated. Betaxolol was provided in a dose of 33 +/- 1.8 mg/kg/day, orally in drinking water, throughout the experimental period. The chronic treatment with betaxolol inhibited the development of hypertension in SHRSP and reduced values of blood urea nitrogen, creatinine, total cholesterol, free cholesterol, triglyceride, phospholipid and HDL-cholesterol in serum. Treatment with betaxolol apparently inhibited the incidence of hypertensive lesions such as cardiac fibrosis, mesenteric vasculitis, proliferative and/or necrotic vasculitis and glomeruli showing collapse or vasculitis in the kidneys. To shorten the time before the onset of hypertension and the subsequent stroke, SHRSP were kept on a SP diet containing 0.39% Na instead of the F-2 diet. When the SHRSP were kept on the SP diet, all of the control SHRSP had cerebral apoplexy and severe hypertensive lesions in the heart and kidney. When betaxolol was chronically administered to SHRSP, cerebral apoplexy and hypertensive lesions in the heart and kidney were inhibited, but the effect on blood pressure was slight. Treatment with betaxolol reduced serum creatinine levels. Our observations show that betaxolol reduces blood pressure and potently inhibits hypertensive complications in SHRSP.
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PMID:[Antihypertensive effects of betaxolol, a cardioselective beta-adrenoceptor antagonist, in stroke-prone spontaneously hypertensive rats (SHRSP)]. 197 70


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