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Experiments conducted with albino rats have evidenced that under the effect of an atherogenic ration the level of lipids and cholesterol in the blood plasma and hepatic tissue and of sillac acids in the blood plasma increased. In the aortic intima the content of acid mucopolysaccharides was rising, this being attended by a concurrent swelling of the main interstitial substance and of the collagen fibers in the subendothelial layer. An addition of apple pectin or of cellulose to the atherogenic ration deferred the development of the mentioned changes.  相似文献   

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Isotope labelled microspheres were used to study the capillary blood perfusion of the rabbit tracheal mucosa. Under resting conditions the perfusion was about 0.3 ml/min - g (i.e. about 60% of the relative cerebral blood flow). Irritation of the tracheal mucosa by an endotracheal tube caused a steep rise in blood flow, tenfold or more. This was probably due to relaxation of the arterioles caused by a release of histamine-like substances. When an endotracheal tube is equipped with a small cuff (small resting diameter, low residual volume), the part of the mucosa in contact with the cuff, i.e. the mucosa covering the surface and edges of the cartilages, will be ischaemic at a cuff to tracheal wall pressure (C-T pressure) of greater than 30 millimeters of mercury. This abrupt ischaemia threshold contributes to the risk of deep mucosal damage with subsequent tracheal scarring, possibly proceeding to stenosis. Our present studies indicate that the ideal large cuff, with properties resembling those of an air cushion, will allow the major part of the arterial pressure to be propagated as far down as the capillaries. Under these conditions the cuff would permit some of the capillary blood perfusion of the tracheal mucosa covering the cartilages also at C-T pressures exceeding 30 mmHg. Although this investigation supports the concept that the ideal thin-walled large cuff interferes much less with the mucosal blood perfusion than the small cuff, we recommend that the cuff pressure be monitored and kept below 20 mmHg.  相似文献   

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Portal hypertension was induced in rats by progressive occlusion of the portal vein or by dimethylnitrosamine (DMNA) cirrhosis. Portasystemic venous connections did not develop in relation to the spleen when this organ was intraperitoneal, but after subcutaneous transposition most of the collaterals were parasplenic and the portal venous pressure fell.  相似文献   

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Little is known about the effects of the pathological process associated with idiopathic portal hypertension (IPH) on hepatic lymph vessels or lymph flow. We used morphometric analysis to examine IPH-associated changes in lymph vessels and branches of the portal vein, with use of immunohistochemical staining for alpha smooth muscle actin. We also quantitated these changes using an image analysis system. The study was conducted with use of liver wedge biopsy material from 10 patients with advanced IPH and 10 control samples from patients with gastric carcinoma without liver disease. The number of lymph vessels, identified by a lack of smooth muscle layer in the wall, and the ratio of the total area of these vessels to that of the portal tract were higher in IPH samples than in the control samples, but the ratio of the area of a single lymph vessel to that of the portal tract in IPH samples was not different from control samples. The number of portal vein branches, characterized by hypertrophy of the smooth muscle layer in IPH samples was not different from control samples. The ratio of the total area of these branches to that of the portal tract, and the ratio of a single portal vein branch to that of the portal tract, were lower in IPH samples than in the control samples. Our results suggest that these morphometric changes in IPH may be associated with a reduction in portal blood flow and increased lymph flow, and that the latter may in turn reduce the high portal vein pressure in idiopathic portal hypertension.  相似文献   

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Assessed latency and redundancy deficit, which reliably show impairment in process schizophrenics, using 20 normal Ss (mean age 30.4 yrs) with no psychiatric history. Ss were tested under standard/optimal and drug-impaired conditions to evaluate whether an expected increase in latency would be accompanied by a correlated increase in redundancy deficit. Ss completed RT trials in which they depressed and released a key in response to slides and a buzzer. Meprobamate was administered for the 2nd series of trials. In other research, the redundancy deficit index has been found to be independent of latency and has shown promise as a marker of schizophrenic information processing difficulty. The present findings confirm the independence of these 2 markers in that no increased redundancy deficit was observed despite a significant increase in latency. Findings also reveal a greater degree of redundancy deficit in normals under the optimal conditions than had been expected. A methodological problem with trial arrangements is discussed, and a review of studies that tested redundancy deficit in normal Ss is presented. (French abstract) (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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BACKGROUND/AIMS: Diminished postprandial portal hyperemia has been demonstrated by echo-Doppler flowmetry in patients with liver cirrhosis, but its diagnostic role is unclear. This prospective study was therefore undertaken in patients with varying severity of portal hypertension and degree of liver cirrhosis. METHODS: Portal flowmetry was performed in 66 patients with cirrhosis and 20 healthy volunteers during fasting and 30 min after ingestion of a standardized meal. Hemodynamic parameters were related to the degree of esophageal varices, variceal bleeding, portal hypertensive gastropathy and Child-Pugh score. RESULTS: The postprandial portal blood velocity increment was low in patients with esophageal varices of any degree (22-24%), compared to patients without varices (49%, p<0.01) and healthy controls (65%, p<0.001), but was not different in patients with or without variceal bleeding (22% vs. 20%). In contrast, the congestion index (CI; ratio of portal vein cross-sectional area and portal blood velocity) pre-/postprandial decreased in the bleeding group only (CI pre/ CI post 1.30+/-0.23 (no bleeding) vs. 0.86+/-0.29 (bleeding); p<0.01). Portal hypertensive gastropathy was not related to any of the portal flow parameters. The portal blood velocity increment was comparable in controls (65%) and patients with Child-Pugh class A cirrhosis (56%), but lower in patients with class B (32%) and class C cirrhosis (15%, p<0.05 vs. class A). Also, there was no postprandial decrease in congestion index in patients with the most severe cirrhosis (p<0.01 class C vs. class A and B). CONCLUSIONS: The postprandial rise in portal flow is inversely related to the severity of portal hypertension and liver cirrhosis, and may be a valuable parameter with respect to the risk of variceal bleeding.  相似文献   

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When ascites develops in a patient with cirrhosis his probability to survive the following 2 years amounts to 50%. It is determined essentially by the residual functional capacity of the liver. In 80 to 90% of patients ascites due to portal hypertension can be managed by salt restriction and diuretics. Aldosterone-antagonists are more efficient and have fewer side effects than loop diuretics. They may lower portal tension by an additional direct effect on the vasculature. A daily reduction of body weight of 0.5 to 0.75 kg should not be exceeded because (prerenal) renal failure may become a threat. If diuretics are insufficient or when a rapid therapeutic success is needed paracentesis of 4-6.1 is a safe option if intravascular volume is substituted simultaneously. Albumin has proven superior to other plasma expanders (protection of renal function, survival). Only in the few patients whose ascites is intractable by the forementioned measures should alternatives such as peritoneo-, venous or porto-systemic shunts (nowadays mostly by interventional techniques via a transjugular catheter) be evaluated. The only treatment which not only attacks ascites symptomatically but also corrects the underlying disease is liver transplantation.  相似文献   

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The authors present the results of study of the blood histamine content in intact rabbits and in the animals to which commercial vaccines with a different degree of reactogenic property for man were administered. The blood histamine level was also studied in practically healthy individuals and in those vaccinated with inactivated tick-borne encephalitis vaccine. The blood histamine content varied in intact rabbits from 4 to 10 microgram/ml, averaging 6.4 +/- 0.09 microgram/ml. Animal immunization caused elevation of the blood histamine content correlating with the reactogenic properties of the preparations for man: vaccines with low reactogenic properties--inactivated encephalitis and live measles vaccine produced no significant changes in the index under study; as to the typhoid vaccine with sextatoxoid, and smallpox vaccine with marked reactogenic properties--they stimulated significant histaminemia in rabbits. Revaccination of man against tick-borne encephalitis with the inactivated cultural vaccine caused an increase in the blood histamine content.  相似文献   

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The defects on rote learning performance of adding positive or negative verbal reinforcers to the information provided by presentation of the correct response was studied in normals and in remitted and nonremitted schizophrenics. On a verbal discrimination task, the reinforcers facilitated the performance of all groups (p  相似文献   

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OBJECTIVES: To assess the effectiveness of two school based smoking education projects in delaying onset of smoking behaviour and in improving health knowledge, beliefs, and values. DESIGN: Cluster randomised controlled trial of two projects taught under normal classroom conditions. Schools were allocated to one of four groups to receive the family smoking education project (FSE); the smoking and me project (SAM); both projects in sequence (FSE/SAM); or no intervention at all. SETTING: 39 schools in Wales and England matched for size and catchment profile. SUBJECTS: All first year pupils in the schools were included and were assessed on three occasions (4538 before teaching (1988), 3930 immediately after teaching (1989), 3786 at one year follow up (1990)). MAIN OUTCOME MEASURES: Self reported smoking behaviour (backed by saliva sample) and change in relevant health knowledge, beliefs, and values. RESULTS: No consistent significant differences in smoking behaviour, health knowledge, beliefs, or values were found between the four groups. For never smokers at baseline the rate of remaining never smokers in 1990 was 74% (594/804) in the control group, 65% (455/704) in the FSE group, 70% (440/625) in the SAM group, and 69% (549/791) in the FSE/SAM group (chi 2adj = 6.1, df = 3, p = 0.1). Knowledge about effects of smoking rose in all groups from a mean score of 5.4 in 1988 to 6.4 in 1989 and 6.5 in 1990. CONCLUSIONS: More comprehensive interventions than school health education alone will be needed to reduce teenage smoking. Other measures including further restrictions on access to cigarettes and on the promotion of tobacco products need to be considered. Further research will be needed to develop effective school based health education projects, which should be formally field tested under normal conditions before widespread dissemination.  相似文献   

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This investigation was designed to determine the role of echocardiography in the assessment of left ventricular function in patients with significant coronary arterial disease. Satisfactory echocardiograms were obtained in 43 patients with coronary arterial disease. The ventriculographic ejection fraction was determined by the area length method. The echocardiographic left ventricular end-diastolic dimension was increased to more than 5-4 cm in 17 patients. Fifteen of these patients had an ejection fraction of 0-45 or less. Three patients had a normal left ventricular end-diastolic dimension but an ejection fraction of less than 0-45. Twenty-three patients had an ejection fraction of more than 0-45 and a normal left ventricular end-diastolic dimension. The left ventricular end-diastolic dimension index was increased (greater than 3 cm/m2) in 15 patients, all of whom had ejection fraction of less than 0-45. Three patients had a normal left ventricular end-diastolic dimension index and an ejection fraction of less than 0-45. Twenty-five patients had a left ventricular end-diastolic dimension index of less than 3 cm/m2 or less and an ejection fraction of more than 0-45. The percentage fractional shortening of the echocardiographic left ventricular dimension was reduced in 25 patients. In 18 of these the ejection fraction was 0-45 or less. The percentage fractional shortening of the left ventricle was normal in 18 patients. In 2 of them the ejection fraction was less than 0-45. In summary, increase of the left ventricular end-diastolic dimension or left ventricular end-diastolic dimension index is usually associated with a critical reduction of the ejection fraction as determined by ventriculography. Since the ejection fraction is an important determinant of mortality related to bypass graft surgery, echocardiography should be useful in the detection of patients with a poor prognosis.  相似文献   

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Selected 64 middle-class, White, 2nd-grade males on the basis of teacher ratings to form highly active and normally active groups. Ss were tested on a 48-min vigilance task in which the critical stimulus was a change in the color of a star located on a cut-out of a jet. Four conditions were used: a control, a feedback about signal occurrence, an extraneous auditory stimulation, and a verbal reminder to pay attention. The highly active group made fewer correct detections than did the control group. Detection efficiency was inversely related to interval length, and this effect was more pronounced for the highly active group. There were no effects of any of the experimental conditions. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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