A cyclic nucleotide and calcium-independent protein kinase of chick brain: Activation by a heat-stable protein

A heat-stable trichloracetic acid-stable protein fraction stimulates protein kinase activity in chick brain cytosol. This protein kinase (tentatively referred to as protein kinase S) can be partially purified by chromatography on DEAE-cellulose and Sepharose G-100. The partially purified protein kinase has an absolute requirement for magnesium and the heat-stable protein for the phosphotransferase activity and is not influenced by cyclic nucleotides, calcium or ethylenediaminetetraacetic acid. The substrate specificity of protein kinase S indicates that it is not a casein kinase and prefers histones over the substrates tested. The specific activity of this protein kinase changes with chick brain development and the activity increased by two-fold by the second post-hatch week, suggesting a role of this protein kinase in chick brain development.     

CAPD腹膜炎的中性粒细胞移行导致蛋白质渗出

目的 :通过CAPD腹膜炎动物模型 ,研究中性粒细胞 (PMNs)移行与蛋白质渗出的关系。方法 :给兔腹腔内注射大肠杆菌 (E .coli) 4× 10 6CFU ,做成急性腹膜炎动物模型。实验前 3d静脉注射氮介 (mustine) ,耗尽循环血中的PMNs(系列一 ) ,或实验前 5min静脉注射单克隆抗体 (mAb 6 0 .3) ,该抗体能与粘附分子CD18结合阻滞PMNs粘附 ,从而抑制PMNs向腹腔移行 (系列二 )。测定两个系列实验中腹透液PMNs计数及蛋白质渗出情况。结果 :系列一 ,mustine将循环血中PMNs降低了 (93 9) % (mean±s) ,此时即使腹腔内注射细菌 ,PMNs向腹腔的移行及腹腔蛋白质的渗出均较未注射mustine的腹膜炎组明显降低 ,而与无腹膜炎的正常对照组结果相近。系列二 ,静脉注射mAb6 0 .3同样也明显降低PMNs向腹腔的移行及腹腔蛋白质渗出。结论 :CAPD中的急性细菌性腹膜炎时PMNs向腹腔移行导致了蛋白质的渗出。     

Protein kinase C and Gi-protein mediated modulation of cAMP production in different stages of the rat seminiferous epithelium

The modulatory role of protein kinase C (PK-C)- and G_i-protein-mediated signal transduction systems was studied in the cyclic variation of follicle-stimulating hormone (FSH)-stimulated cAMP production of rat seminiferous tubules. FSH (Metrodin, Serono, 30 mg/1) stimulated cAMP production 10-fold (p < 0.01) in a 3 h incubation of 5 mm segments of seminiferous tubules of stages II–VI of the epithelial cycle, but only 2-fold (p < 0.01) in stages VII–VIII. The PK-C activator 12-O-tetradecanoylphorbol 13-acetate (TPA, 100 nmol/1) suppressed the FSH effect on cAMP output by 50–70% (p < 0.01) in stages II–VI, but had no effect in stages VII–VIII. If the tubular segments were preincubated for 3 h in the presence of pertussis toxin (PT, 100 μg/1), the FSH-stimulated cAMP production of stages VII-VIII increased by 100–200% (p < 0.01), and now they also became responsive to the TPA suppression. Conversely, no effect of PT was observed in stages II–VI. Cholera toxin (CT, 100 μg/1) and forskolin (Fk, 100 μmol/1) nearly similarly stimulated the cAMP production in both stages studied (about 10-fold, p < 0.01), and TPA and PT potentiated the effects in a non-additive fashion. In conclusion, both G_i-protein and PK-C-mediated mechanisms modulate cAMP production of rat seminiferous tubules. A clear cyclic variation can only be demonstrated in FSH-stimulated cAMP production, but not if the G_s-protein or adenylate cyclase are directly stimulated. Upon FSH stimulation, the low cAMP production in stages VII–VIII is mainly due to the G_i-protein-mediated inhibition. In contrast, the absence (or non-function) of this inhibition mechanism explains the brisk cAMP response to FSH in stages II–VI. PK-C activation suppresses FSH-stimulated cAMP production only if it is not inhibited by the G_i-protein-mediated mechanism (stages II–VI), probably by inhibiting the FSH-receptor-G_s-protein association. It also increases CT and Fk-stimulated cAMP production, in this case inactivating the G_i-protein.     

Protein sparing and protein replacement in acutely injured patients during TPN with and without amino acid supply

The metabolic effects of TPN were studied in a selected group of trauma patients. Nineteen patients were randomly divided into two groups: the first was treated with glucose and insulin, the second with glucose, insulin and amino acids. Each patient in both groups received TPN isocaloric with respect to daily energy output and the treatment lasted five days. Each group was further divided into two subsets (severe or moderate catabolism) according to fasting energy output with respect to the expected energy expenditure. During the acute flow phase, both in moderate as well as in severe catabolism, glucose and insulin were effective for protein sparing; the maximum protein sparing effect was reached when giving a caloric intake equal to 130% of daily energy output. Glucose, insulin and amino acids were effective in replacement of nitrogen losses. In moderately catabolic patients nitrogen balance was significantly better than in severely catabolic patients. This study shows that early and short-term TPN is effective in controlling the flow phase of trauma. Glucose and insulin appear to be the determinants of the protein sparing effect when given in amounts equal to those needed; amino acids provided protein replacement when given in amounts equal to about 20% of energy output. Energy supply higher than 120–130% of daily energy output does not increase protein sparing and protein replacement, the only effect being a further increase in metabolism, which is possibly dangerous in critically ill patients.     

Ultrasonic absorption in the human breast cyst liquids.

The ultrasonic absorption of samples of cyst liquids (CL) of the human breast has been measured as a function of frequency (1.67–115 MHz), pH (1–13), dilution and temperature (25 and 37°C). The absorption behavior of these liquids is very similar to that of protein solutions. It is shown that the absorption of CL at physiological pH arises essentially from the protein contained in these liquids and, in fact, can be evaluated to within a factor 1.5, from that of serum albumin in similar condition. The origin of this absorption is discussed.     

镁钙离子诱导的人凝血因子Ⅸ、蛋白C的构象变化及其与相应特异单抗的连接状态

用圆二色光谱、荧光光谱及紫外差光谱研究镁钙离子诱导的ＦⅨ、ＰＣ的构象变化并通过蛋白负染电镜及荧光偏振实验观察了各构象与ＦⅨ、ＰＣ特异单抗的连接状况。ＦⅨ、ＰＣ在镁钙离子诱导下，其３种光谱均发生显著变化，并且与缓冲液中的金属离子浓度有关。ＦⅨ、ＰＣ的特异单抗仅与ＦⅨ、ＰＣ的某种特定构象发生连接反应。     

ABC免疫电泳对膀胱癌P21蛋白表达的观察

用ＡＢＣ免疫电泳检测了２９例膀胱移行细胞癌、６例癌旁粘膜、３例膀胱炎和３例正常膀胱粘膜的Ｐ２１蛋白表达，发现２５例（８６．２％）膀胱癌、３例癌旁组织、１例正常膀胱膜、２例胶胱炎组织有Ｐ２１蛋白表达。随肿瘤分级增高，Ｐ２１蛋白条带的光密度积分增加；肿瘤组织Ｐ２１蛋白光密度积分高于癌旁组织，癌旁组织又高于正常膀胱粘膜。     

Protein and amino acid metabolism after severe cerebral trauma

Fourteen patients (20–48 years) suffering from severe head injury were followed for changes in amino acid and protein metabolism during the first 8 days after trauma. All patients received a standardized intravenous nutrition containing 15.7 g of nitrogen per day and additional carbohydrates. Electrolytes, free water, and blood constitutuents were given as needed. Additional treatment included surgical decompression of space-occupying hematomas, high dose dexamethasone therapy, and controlled hyperventilation for at least 5 days. Gross changes of protein metabolism were observed particularly on the days 5 and 6. The duration and chronological sequence of these changes are different from those usually found in patients with multiple injuries.