生殖腺及生殖腺外畸胎瘤的超声诊断

目的；探讨超声对各部位畸胎瘤的诊断价值。方法：对42例经手术及病理证实的畸胎瘤与超声检查结果对照，并回顾分析其声像特征。结果：畸胎瘤具有一些特征性声像图表现，其肿块检出率100％，诊断符合率89．8％，其中生殖腺畸瘤诊断符合率96．8％，生殖腺外畸胎瘤诊断符合率82．0％。结论：畸胎瘤的超声诊断符合率较高，应为目前首选检查方法。少见部位畸胎瘤因认识不足易造成误诊，良恶性的鉴别亦存在误差。     

One-year death rate in 270 patients with suspected acute myocardial infarction, initially treated with intravenous magnesium or placebo

In a double-blind, placebo-controlled study, 273 patients with suspected acute myocardial infarction (AMI) were randomized to receive either 48-h magnesium (Mg) or placebo therapy intravenously, initiated immediately on admission to hospital. We describe the results from a 1-year survey in 270 of the patients, who were available for follow-up. Patients were equally divided: 135 received Mg and 135 received placebo. Mg treatment was associated with a marked reduction in 1-year death rate from 32% in the placebo group to 20% in the Mg group (p = 0.018). If only death from ischemic heart disease is considered, the figures were 28% in the placebo group as opposed to 15% in the Mg group (p = 0.006). This reduction was mainly due to a reduction in mortality during the initial 30 days after inclusion in the study (17% vs. 7%), after which the difference in mortality between the two groups did not reach statistical significance (18% vs. 15%, p = 0.56). The beneficial effect of Mg on mortality was partly linked to a reduced incidence of arrhythmias (27% vs. 16%), and partly to a reduced incidence of infarction (63% vs. 48%) during the initial hospitalization. However, factors unknown to us were also involved, as revealed by a remaining statistically significant partial regression coefficient, when sex, age, cardiovascular history, development of AMI, and development of arrhythmias were considered. It is concluded that intravenous Mg treatment is beneficial to patients with acute ischemic heart disease and should be adopted as part of the routine treatment of these patients.     

The relationship between gallbladder dynamics and the migrating motor complex in fasting healthy subjects

The relationship between gallbladder dynamics and the interdigestive migrating motor complex (MMC) was investigated in 10 healthy male volunteers by a hepatobiliary scintigraphy and gastroduodenal pressure recordings. Filling of the gallbladder commenced in late phase II or in phase III of the MMC and continued in a linear fashion during the following phase I. Simultaneously, an abrupt decrease in delivery of activity into the duodenum was encountered. Emptying of the gallbladder always occurred in phase II and lasted 14-46 min (median, 30 min). The transformation from filling to emptying of the gallbladder was closely related to changes from phase I to II on the motility curve.     

GnRH release from the mediobasal hypothalamus: in vitro inhibition by corticotropin-releasing factor

The effects of corticotropin-releasing factor (CRF) on GnRH release from the adult male rat mediobasal hypothalamus (MBH) and median eminence (ME) were studied in an in vitro incubation system. CRF induced a dose-related inhibition of GnRH release from both the MBH and the isolated ME, and this inhibition was blocked by treatment with CRF receptor antagonist. Moreover, GHRF, a hypothalamic peptide similar in size to CRF, did not alter the ME release of GnRH. These results demonstrate that CRF can inhibit in vitro release of GnRH by a CRF receptor-mediated mechanism at the level of the neurosecretory terminals in the ME. Thus, increased hypothalamic CRF secretion associated with stress and adrenalectomy may inhibit hypothalamic GnRH release and produce the suppression of pituitary luteinizing hormone secretion which occurs under these conditions.     

Estrogen regulation of the biological activity of the avian oviduct progesterone receptor and its ability to induce avidin

During primary estrogen stimulation of chick oviduct development, estrogen withdrawal, or secondary estrogen treatment, changes in the oviduct progesterone receptor (PR) occur. The presence of estrogen appears to regulate not only PR concentration but also its biochemical activity, i.e. its capacity to bind to nuclear acceptor sites and alter RNA synthesis. This study reports that estrogen regulates the nuclear binding capacity of the PR even more rapidly than previously reported in fully developed oviducts of chicks that have been injected daily for 4 weeks with diethylstilbestrol (DES). Further, the nuclear binding capacity of the PR correlates with the ability of progesterone (P) to induce avidin protein concentrations in the oviducts in vivo. The PR concentration in the oviducts increases 2-fold within 8 h of the last injection and the decreases to a minimal value by 24 h. Injection of [3H]P into the chicks shows that the in vivo nuclear localization of the steroid increases almost 4-fold at 8 h, followed by a similar decrease to minimal values by 24 h. Cell-free nuclear binding assays, using PR isolated at various times after the last DES injection and oviduct nucleoprotein complexes, indicate that the capacity of the receptors to bind to nuclear acceptor sites is regulated by the estrogen. The enhanced nuclear binding capacity of the isolated PR increases to maximal values by 12-14 h after the last estrogen treatment and then begins to decrease to minimal values by 24 h. Similarly, the ability of P to induce in vivo avidin protein concentrations and to alter general RNA synthesis in the oviducts is reduced by 70% (of the estrogen non-withdrawn chick levels) by 24 h after the last estrogen injection. These changes over the 24-h period after the last DES treatment are not due to changes in the serum DES concentrations. The following 10-day period of estrogen withdrawal reveals a cyclic decaying pattern in the capacity of the PR for nuclear binding. The P induction of avidin and alteration of RNA polymerase II activity, using nuclear run-off experiments, also show a similar cyclic decaying pattern. By 6 days of estrogen withdrawal, the PR is incapable of any nuclear binding, and P cannot induce avidin protein concentrations in the oviducts. Serum DES concentrations over this 10-day period display only a gradual decay.(ABSTRACT TRUNCATED AT 400 WORDS)     

Differential glycaemic effects of potato,rice and spaghetti in Type 1 (insulin-dependent) diabetic patients at constant insulinaemia

Summary The blood glucose responses to cooked potato, rice and spaghetti were studied in six Type 1 (insulin-dependent) diabetic patients who had attained euglycaemia by the artificial pancreas prior to the meal intake. The amount of potato (raw weight 200 g), parboiled rice (raw weight 50 g), and spaghetti (raw weight 50 g) had approximately identical caloric content (range 203–225 kcal) and amount of available carbohydrate (range 39.4–43.4g). The postprandial blood glucose response areas after cooked potato and cooked parboiled rice were similar (180 min values: cooked potato: 1190 ±110 mmol/l x min, cooked rice: 1160 ± 140 mmol/l x min and 240min values: cooked potato: 1690 ± 140 mmol/l x min, cooked rice: 1740 ± 210 mmol/l x min). In contrast, the response after cooked spaghetti was slower and less pronounced (180 min value: 830 ± 80 mmol/1 x min and 240 min value: 1320 ± 120 mmol/1 x min), and was significantly smaller than those of cooked potato (180 min: 2p < 0.01 and 240 min: 2p < 0.01) as well as cooked rice (180 min: 2p < 0.01 and 240 min: 2p < 0.02). Our study emphasizes the importance of determining the glycaemic response of foodstuffs under conditions of isoinsulinaemia.     

Diagnostic value of ascitic fluid cholesterol levels in the prediction of malignancy

In a prospective study abdominal paracentesis with ascitic fluid aspiration was performed in 54 consecutive patients with ascites of unknown cause. The ascitic fluid was examined cytologically and bacteriologically. The total cholesterol concentration was measured with an enzymatic colorimetric method. Malignant disease was diagnosed in 34 patients. Two of them had both malignant disease and liver cirrhosis and were excluded. Seventeen patients had liver cirrhosis, one had acute pancreatitis, and two had decompensated heart disease. The diagnostic value of an ascitic cholesterol concentration greater than 1.2 mmol/l in terms of predicting malignant disease was 87.5% (95% confidence limits, 71.0-96.5). The predictive value of an ascitic cholesterol concentration less than or equal to 1.2 mmol/l in terms of benign disease was 80.0% (95% confidence limits, 56.3-94.3). It is concluded that ascitic cholesterol measurement is a valuable supplement to cytologic examination in distinguishing between ascites of malignant and benign origin.     

Protein phosphorylation changes in bovine carotid artery smooth muscle during contraction and relaxation

The protein phosphorylation changes associated with the contraction and relaxation of bovine carotid artery smooth muscle were studied using two-dimensional gel electrophoresis of labeled phosphoproteins. Muscle was stimulated with histamine, angiotensin II, 12-deoxyphorbol 13-isobutyrate (DPB) or high extracellular K+. Histamine induced a rapid and sustained contraction which was associated with an early (2 min) phosphorylation of 20 kDa myosin light chain (MLC) and two cytosolic proteins, Nos. 1 and 2, and with the late (60 min) phosphorylation of MLC, two isoelectric variants of desmin and ten other cytosolic proteins. Additionally, there was a decrease in the extent of phosphorylation of two cytosolic proteins, Nos. 9 and 10. Angiotensin II induced a rapid but transient contraction which was associated with the same early (2 min) phosphorylation changes, but with none of the late (60 min) changes. Elevation of the extracellular K+ concentration to 110 mM led to a sustained contraction which was associated with the phosphorylation of MLC and proteins Nos. 1 and 2 at both 2 and 60 min, but none of the other late phase phosphoproteins were seen. Addition of DPB, an activator of protein kinase C, induced a slowly developing but sustained contractile response which was associated with none of the early (5 min) phosphorylation changes. However, nearly all of late (60 min) protein phosphorylation changes were the same as those seen after histamine action. Addition of forskolin to either control or histamine-treated muscle led to an increase in the phosphorylation of three cytosolic proteins (Nos. 3, 8 and 13), and in the histamine-contracted muscle the dephosphorylation of MLC and proteins Nos. 4, 9, 10, 15 and 16. Similarly, forskolin induced a relaxation of DPB-treated muscle and the dephosphorylation of proteins Nos. 4, 9, 10, 15 and 16. These results suggest that there are two pathways by which histamine activates contraction: a Ca2+-calmodulin pathway which initiates the response, and a protein kinase C pathway which, along with the Ca2+-calmodulin pathway, sustains contraction.     

Classical conditioning induces long-term translocation of protein kinase C in rabbit hippocampal CA1 cells.

The role of the Ca2+/phospholipid-dependent, diacylglycerol-activated enzyme protein kinase C (PKC) in rabbit eyelid conditioning was examined. PKC was partially purified from the CA1 region of hippocampal slices from naive, pseudoconditioned, and conditioned rabbits 24 hr after the rabbits were well conditioned. Crude membrane and cytosol fractions were prepared. In conditioned rabbits, significantly more PKC activity (63.3%) was associated with the membrane fraction (and significantly less with the cytosol fraction) compared to naive (42.0%) and pseudoconditioned (44.7%) animals. These differences in distribution of enzyme activity were paralleled by differences in stimulation of enzyme activity by Ca2+, phospholipid, and diacylglycerol. There were no between-group differences in basal protein kinase activity. These results suggest that there is a long-term translocation of PKC from cytosol to membrane as a result of conditioning. Autoradiographic binding of radioactive phorbol 12,13-dibutyrate to PKC demonstrated that almost all specific binding was in the stratum radiatum, a region containing the proximal apical dendrites of CA1 pyramidal neurons. Therefore, this may be the site of the conditioning-specific PKC translocation, a locus well-suited to underlie the biophysical effects of conditioning.