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1.
Sex-based differences in serum leptin concentrations have been reported in adolescence and adulthood. To discover when such differences were generated, serum leptin concentrations were measured in umbilical cord blood from 46 healthy infants and in the mother's blood at delivery. Considering the respective body weights of the mothers and infants (68.5 +/- 1.3 kg and 3.3 +/- 0.0 kg), umbilical cord concentrations of leptin were disproportionately high in the infants (9.4 +/- 1.2 micrograms/l) compared with those in the mothers (18.7 +/- 1.3 micrograms/l). There was a wide variation in the infants leptin values (1.2 +/- 56.8 micrograms/l) that did not correlate with height, weight, cephalic circumference, or any other growth-related parameter. The most striking differences emerged when results were analysed by sex: umbilical cord concentrations of leptin in the girls (12.9 +/- 2.2 micrograms/l) were significantly (P < 0.01) greater than those in the boys (6.8 +/- 0.9 micrograms/l), although no differences in leptin concentrations were observed between the mothers who gave birth to a girl (19.5 +/- 2.2 micrograms/l) and those who gave birth to a boy (18.1 +/- 1.7 micrograms/l). The sex-based differences were not attributable to any growth-related differences between the sexes, except heavier placental weights in the girls (P < 0.007) than in the boys. These differences in leptin concentrations may reflect a sex-based difference in the regulation of leptin production by the fetal adipose tissue.  相似文献   

2.
Guan-fu base A (GFA) is a terpenoid alkaloid isolated from the tuber of Aconitum coreanum in our institute. GFA (20-30 mg.L-1) reduced the ventricular tachycardia (VT) and ventricular fibrillation (VF) rate induced by K(+)-free and high Ca2+ solution in Langendorf heart of rats. Pretreatment of conscious rats with GFA 2.5-10 mg.kg-1 iv, increased the amount of beiwutine necessary to produce arrhythmias. Ouabain-induced VT in conscious dogs was reverted to sinus rhythm in 1-2 min by iv GFA 9-10 mg.kg-1. GFA 10-20 mg.kg-1 iv was also found to be effective in protecting anesthetized dogs from atrial fibrillation induced by topical application of ACh. GFA 10 mg.kg-1 iv obviously decreased heart rate and prolonged the P-R interval, but slightly affected the myocardial contractility in anesthetized dogs. GFA showed no obvious effect on stroke volume and cardiac output in conscious dogs. In conclusion, GFA showed therapeutic and prophylactic effect on different models of experimental arrhythmias without causing marked effect on myocardial contractility.  相似文献   

3.
In a sample of 34 study subjects, Cook and Jamshidi intraosseous (IO) needles were compared for ease of insertion into turkey bones. The averaged lapsed time of insertion was significantly shorter using the Jamshidi needle (25.5 v 56.2 seconds, P < .0001). The mean difficulty of insertion score was lower using the Jamshidi needle (3.0 v 7.1 on a 10-cm visual analog scale, P < .0001). The less costly Jamshidi needle is easier to use in IO insertion in this turkey bone model.  相似文献   

4.
The optimal temperature of blood cardioplegia remains controversial. Interstitial myocardial pH was monitored online with a probe that was inserted in the anterior wall of the left ventricle. Venous pH, lactate production, and creatine kinase and troponin T release were measured in coronary sinus blood obtained in 14 dogs after ischemic arrest periods of 5, 10, 20, and 40 minutes with warm (n = 7; mean myocardial temperature, 35 degrees +/- 2 degrees C) and cold (n = 7; mean myocardial temperature, 12 degrees +/- 1 degree C) blood cardioplegic protection. Blood cardioplegic solution was delivered at a rate of 100 mL/min during the 10 minutes between each ischemic arrest. The interstitial myocardial pH decreased significantly (p < 0.05) from 7.1 +/- 0.3 to 6.53 +/- 0.3 after ischemia in animals perfused with warm blood cardioplegia and from 7.04 +/- 0.3 to 6.64 +/- 0.1 in those receiving cold blood cardioplegic protection; however, the difference between the groups was not significant (p > 0.05). Lactate production and creatine kinase and troponin T release increased significantly after ischemia, but there was no difference in the changes between the warm and cold blood cardioplegia groups. In conclusion, ischemia caused significant changes in all variables measured, and these changes were directly proportional to the duration of ischemia. However, there was no significant difference (p > 0.05) in the myocardial metabolic changes between the warm and cold blood cardioplegia groups in terms of the duration of ischemic arrest studied.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
Dobutamine echocardiography has gradually acquired a place among the currently available techniques to evaluate myocardial viability. It is a very efficient technique, easily accessible and inexpensive. It detects preservation of the myocyte contractile apparatus, which unlike other tests best assesses myocardial viability. Its value in stunned and hibernating myocardium is herein described.  相似文献   

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Dynamic brain scintigraphy was performed on seven patients with documented hydrocephalus of various aetiologies. The patients had a characteristic abnormality consisting of lateral displacement of the proximal middle cerebral activity associated with a paracentral lucent zone. No focal areas of increased activity were identified on the static brain images. A proposed mechanism for these findings is discussed.  相似文献   

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BACKGROUND: Incubating blood with phosphoenolpyruvate decreases hemoglobin oxygen affinity (HOA). This study compared transfusion with phosphoenolpyruvate-treated blood and conventionally stored blood on oxygen consumption in acutely anemic dogs. METHODS: Dogs underwent isovolemic hemodilution (hematocrit = 10%). After 1 hour they were transfused to a hematocrit of 18% with control or phosphoenolpyruvate treated blood. Cardiac output, co-oxymetry, and hemoglobin P50 measurements allowed calculation of oxygen consumption during anemia, and posttransfusion. RESULTS: Hemodilution doubled cardiac output. Transfusion with phosphoenolpyruvate-treated blood allowed greater O2 consumption than control (8.31+/-2.1 and 3.73+/-0.11 cc/kg/mm). There were no differences in arterial or venous PO2 or pH; there were marked differences in HOA, measured by posttransfusion P50 (21+/-3 versus 47+/-4), and mixed venous O2 saturation. CONCLUSIONS: Decreased HOA results in increased O2 consumption in dogs subjected to anemic hypoxia. Phosphoenolpyruvate-treated blood provides increased oxygen consumption at a similar hematocrit when compared with untreated banked blood.  相似文献   

11.
The aim of this study was to assess the value of low dose dobutamine (5 and 10 gammas/Kg/min) echocardiography for the detection of hibernating myocardium in an infarcted zone three weeks after the initial infarction. The authors studied 23 patients (18 men, 15 women) with an average age of 59 +/- 8 years before and 3 months after angioplasty of the culprit artery. Segmental wall motion was assessed semi-quantitatively by the criteria of the American Society of Echocardiography. All patients had regional contractile abnormalities under basal conditions and all underwent control coronary angiography at 3 months. Improvement of segmental wall motion with dobutamine predicted improvement after revascularisation with positive and negative predictive values of 95% and 85% respectively. The sensitivity and specificity of the test calculated in the usual manner were 83% and 96% respectively. In addition, assessment of diastolic function showed reduction of the isovolumic relaxation time with dobutamine only in patients with hibernating myocardium (120 +/- 30 ms decreasing to 114 +/- 29 ms with dobutamine, p < 0.02). Low dose dobutamine echocardiography therefore allows reliable non-invasive prediction of hibernating myocardium three weeks after infarction. The reduction of isovolumic relaxation time with dobutamine could be an additional argument in favour of the diagnosis.  相似文献   

12.
OBJECTIVES: The purpose of this study ws to assess whether a community program begun in March 1988 that organized multiple city departments and private citizens could reduce alcohol-impaired driving, related driving risks, and traffic deaths and injuries. METHODS: Trends in fatal crashes and injuries per 100 crashes were compared in Saving Lives Program cities and the rest of Massachusetts from March 1984 through February 1993. In annual roadside surveys conducted at randomly selected locations, safety belt use among occupants of 54577 vehicles and travel speeds of 118442 vehicles were observed. Four statewide telephone surveys (n = 15188) monitored self-reported driving after drinking. RESULTS: In program cities relative to the rest of Massachusetts during the 5 program years in comparison with the previous 5 years, fatal crashes declined 25%, from 178 to 120, and fatal crashes involving alcohol decreased 42%, from 69 to 36. Visible injuries per 100 crashes declined 5%, from 21.1 to 16.6. The proportions of vehicles observed speeding and teenagers who drove after drinking were cut in half. CONCLUSIONS: Interventions organized by multiple city departments and private citizens can reduce driving after drinking, related driving risks, and traffic deaths and injuries.  相似文献   

13.
This study compares side-by-side exercise electrocardiography and dobutamine echocardiography with an invasively assessed index of myocardial flow (pressure-derived myocardial fractional flow reserve). The data show that ST-segment depression > or = 0.1 mV and the occurrence of new wall motion abnormalities during dobutamine infusion reflect a similar impairment of myocardial blood flow.  相似文献   

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Reduction of the splenic volume by partial resection and collateral development after transposition are of potential value in the elective treatment of esophageal varices, hypersplenism and ascites. A study was performed on young Wistar rats. A simple animal model of extrahepatic portal hypertension was used, narrowing the portal vein to an outer diameter of one millimeter (PVS). One day, three weeks and seven weeks after this operation the portal venous pressure was elevated as compared with the sham-operated controls. The portal hypertension was statistically significant at week three (1.31 +/- 0.04 vs. 0.72 +/- 0.18 kPa, p = 0.01). Portocaval pressure gradient after partial resection of the spleen (SR) and intramuscular transposition (IMTrans) was compared with the pressure gradient after graded portal vein stenosis. Three weeks after intramuscular transposition portocaval pressure gradient was reduced (1.46 +/- 0.38 vs. 1.74 +/- 0.13 kPa, n.s.). This data supports the hypothesis that the portal venous high-pressure compartment and the systemic venous low-pressure compartment are maintained after development of natural shunts to the systemic circulation. In the following experiment different types of splenic transposition were tested and compared to each other and a normal control group or to rats with protal vein stenosis (PVS), respectively. After PVS, the animals were reoperated, an SR was performed and the wound surface of the spleen was transposed into the left abdominal wall subcutaneously (SCTrans) or intramuscularly (IMTrans) or to the left liver lobe (splenohepatoplasty, SHP), respectively. After three weeks the animals underwent measurements of organ weights, collections of blood samples and the spleen was investigated histologically. Blood cell counts were nearly normal but total serum protein, albumin and the colloid osmotic pressure were slightly diminished or significantly reduced (COP in the groups PVS + SR + IMTrans or SCTrans, p < 0.05) compared to the controls. Differences to the group with portal vein stenosis (PVS) were not significant. Serum protein electrophoresis after splenic transposition revealed an unobtrusive distribution pattern. Animals after SHP had the best increase in weight and high protein levels, but splenohepatic collateral development seemed sparse. Differences of plasma ammonium levels were statistically not significant, but some animals had elevated levels after transposition. Morphometry of routine-stained spleen specimens showed an intact immunoarchitecture of the transposed spleens.  相似文献   

16.
Previous research has supported theoretical claims that dichotomous thinking may be a risk factor for suicide. However, the concept of dichotomous thinking is vague, and thus far, no measures of it have been developed. This study developed a coding scheme useful on Thematic Aperception Test (TAT; Murray, 1943) protocols and applicable to other verbal productions to refine the concept of dichotomous thinking and to assess its utility as a predictor of suicidality. Suicidal patients had a significantly elevated rate of a narrowly defined type of dichotomous thinking involving diametric or polarized possibilities. However, suicidal and nonsuicidal patients did not differ on weaker forms of dichotomous thinking involving nonexclusive or nonbinary alternatives. Suicidal patients produced shorter TAT stories than nonsuicidal patients, supporting other findings in the literature that suicidal patients tend to be cognitively and affectively "shut down." Traditionally designated "suicide cards" also yielded shorter stories but did not elicit higher rates of dichotomous thinking.  相似文献   

17.
This study compared flow-sensitive magnetic resonance imaging with biplane transoesophageal echocardiography in combination with continuous wave Doppler from the suprasternal notch in patients with native coarctation or after surgical repair. Twenty patients (mean age 33 years, range 17-60) were investigated, of whom 15 had undergone surgery at mean age 13 years, range 5-43. Peak and mean flow in the ascending and descending aorta as well as coarctation peak velocity were determined with the magnetic resonance imaging phase contrast technique. Coarctation peak velocity was also measured by Doppler from the jugulum. Magnetic resonance imaging axial sections as well as biplane transoesophageal echocardiography were used to measure the smallest diameter of the constricted segment. Sixteen healthy volunteers, mean age 36 years, range 22-63, provided reference values for magnetic resonance imaging determined volume of flow in the aorta. Peak flow in the descending aorta was 9.2 +/- 3.7 l. min-1 (reference 13.0 +/- 2.5, P < 0.01) and mean flow 3.1 +/- 0.9 l. min-1 (reference 3.4 +/- 0.8, P > 0.05). The ratio of descending-to-ascending peak flow was 0.54 +/- 0.17 (reference 0.69 +/- 0.10, P < 0.01) and mean flow 0.68 +/- 0.15 (reference 0.69 +/- 0.08, P > 0.05). The coarctation velocity was slightly higher with Doppler than with magnetic resonance imaging (+0.24 +/- 0.44 m. s-1, 95% confidence interval +0.45 to +0.02 m. s-1, P = 0.05). The coarctation diameter was slightly larger with magnetic resonance imaging than with transoesophageal echocardiography (1.4 +/- 3.5 mm, 95% confidence interval +3.1 to -0.3 mm, P = 0.11). Both methods are suitable for the assessment and follow-up of coarctation of the aorta. Flow assessment with magnetic resonance imaging provides a hitherto unavailable measure with which to assess the severity of obstruction.  相似文献   

18.
The role of transoesophageal echocardiography (TOE) in anaesthesia remains controversial because it is a rapidly evolving technique with few proven benefits and considerable cost. Recently, the Society of Cardiovascular Anaesthesiologists has published practice guidelines for the use of peri-operative TOE. To determine the current role of transoesophageal echocardiography and the relative impact of category-based transoesophageal echocardiographic indications the present study investigated its use in seven Western European countries. The study sample was taken from a prospective cohort of 224 patients with acute or chronic haemodynamic disturbances or at risk of myocardial ischaemia. All patients were monitored with two-lead electrocardiography and radial and pulmonary artery catheters, as well as biplane or multiplane transoesophageal echocardiography. A total of 2232 clinical interventions were made in these patients. The most frequently observed intervention was the administration of a fluid bolus (45% of all interventions). Overall, transoesophageal echocardiography was the most important guiding factor in 560 (25%) interventions. It was the most important monitor in guiding the following therapeutic interventions: anti-ischaemic therapy--207 of 372 interventions (56%); fluid administration--275 of 996 (28%) interventions; vasopressor or inotrope administration--56 of 316 (16%) interventions; vasodilator therapy--six of 142 (4%) interventions and depth of anaesthesia--four of 211 (2%) interventions. We found that transoesophageal echocardiography is frequently influential in guiding clinical decision making and is used most frequently for category II indications but category I indications were associated with more frequent change in management.  相似文献   

19.
The aim of this study was to evaluate the relation between myocardial perfusion and ST-segment changes in patients with acute myocardial infarction treated with successful direct angioplasty. Thirty-seven patients, successfully treated with direct angioplasty, underwent myocardial contrast echocardiography before and after angioplasty. The sum of ST-segment elevation divided by the number of the leads involved (ST-segment elevation index) was calculated at 1, 5, 10, 20, and 30 minutes after restoration of a Thrombolysis In Myocardial Infarction trial grade 3 flow. After recanalization, myocardial reperfusion within the risk area was observed in 26 patients, whereas a no-reflow phenomenon occurred in 11. In patients with myocardial reperfusion, the ST-segment elevation index progressively declined, whereas in patients with no reflow, no significant change was observed. Reduction of > or = 50% in the ST-segment elevation index occurred in 20 of the 26 patients with reflow and in 1 of the 11 with no reflow (p = 0.0002). An additional increase of > or = 30% in the ST-segment elevation index occurred in 3 patients with reflow and in 7 with no reflow (p = 0.003). Sensitivity, specificity, positive and negative predictive values, and accuracy of the reduction in the ST-segment elevation index for predicting microvascular reflow were 77%, 91%, 95%, 62%, and 81%, respectively. The corresponding values of the increase in ST-segment elevation index for predicting no reflow were 64%, 88%, 70%, 85%, and 81%, respectively. In conclusion, after successful angioplasty, different patterns of myocardial perfusion are associated with different ST-segment changes. Analysis of ST-segment changes predicts the degree of myocardial reperfusion.  相似文献   

20.
Adhesion-dependent cell signaling is known to be important in carcinogenesis. It is postulated that several types of adhesion molecules act as tumor suppressor genes by enforcing cell-substrate and cell-cell adhesion thereby preventing the migration of cells and their invasion into surrounding tissues. Recent evidence, however, suggests that disruption of adhesion systems can both initiate neoplastic transformation and contribute a rate-limiting step to progression. Adhesion may modulate neoplastic processes by altering pathways that control genomic stability. Analysis of the adhesion-controlled inactivation of the p53 protein and the concomitant relaxation of cell cycle checkpoint control could identify the critical contributions of adhesion-mediated influences to carcinogenesis.  相似文献   

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