Evidence for negative control in protein kinase C substrate specificity

The peptide Leu-Asp-Asp-Ser-Lys-Arg-Val-Ala-Lys-Arg-Lys-Leu-Ile-Glu, which corresponds to sequence 124 to 137 of c-erb-A protein, was synthesized and tested as substrate for protein kinase C (PKC). Although a typical recognition sequence for PKC, consisting of a cluster of basic residues, is found on the C-terminus side of serine, its phosphorylation was totally prevented by the presence of the two acidic residues on the amino-terminus side. Three analogs in which aspartyl residues were successively replaced with alanine were studied and the influence of the acidic side chain in modulating phosphorylation by PKC was thus possible to determine. The results show that the presence of a single aspartyl residue located in positions i-1 or i-2 with respect to the phosphorylable residue can almost totally abolish the positive effect of a highly favorable cluster of basic residues. These observations highlight the role of negative substrate specificity determinants in settling the protein substrate profile of protein kinase C.     

Clinical and immunological effects of azithromycin in Behçet''s disease

Background: The aim of this study was to evaluate the effects of azithromycin on mucocutaneous manifestations, oral health and immune response in Behçet's disease (BD). Methods: Eight BD patients with active mucocutaneous symptoms were treated with azithromycin for 4 weeks. Oral health, clinical manifestations and in vitro interleukin (IL)‐12, interferon (IFN)‐γ, IL‐10 and monocyte chemotactic protein (MCP)‐1 responses were evaluated before and after treatment. Results: The number of folliculitic lesions, healing time of oral ulcers and scores of plaque indexes (PLIs) were lower after azithromycin treatment (P < 0.05). Scores of PLIs correlated positively with the healing time of oral ulcers (P = 0.02). Although a trend towards increased stimulated IL‐10 responses with azithromycin was observed, no statistically significant difference was found. Stimulated and unstimulated MCP‐1, IFN‐γ and IL‐12 responses were similar before and after treatment (P > 0.05). Conclusion: Azithromycin was observed to be effective in decreasing folliculitic lesions and fastening the healing time of oral ulcers in BD.     

Changes in blood pressure and vasoactive hormones during volume expansion in stable patients on chronic haemodialysis

Summary: We studied changes in blood pressure (BP) and plasma hormones (atrial natriuretic peptide [ANP], brain natriuretic peptide [BNP], endothelin [ET], angiotensin [AII] and renin [PRA]) in four stable haemodialysis patients 48 h after a routine dialysis (basal stat), after volume expansion (4–7% above dry bodyweight) for 4 days then 48 h later following ultrafiltration. Blood pressure rose and plasma AII and PRA values fell with volume expansion and returned to baseline at the end of the study. Endothelin values were unchanged. Plasma ANP and BNP rose similarly in three patients and returned to near baseline levels after ultrafiltration. Sustained volume expansion over 4 days in dialysis patients is associated with an increase in BP, a marked elevation in plasma ANP and BNP but without change in ET.     

心房颤动犬心房肌细胞2型理阿诺受体的分布和表达

目的探讨心房颤动(房颤)时心房肌细胞2型理阿诺受体表达和分布的改变。方法杂种犬10只,分为正常对照组和单纯房颤组,每组5只。单纯房颤组用起搏器进行房颤式快速起搏,起搏频率(500±20)次/min,正常对照组不植入起搏器。24周后取出心脏,用逆转录聚合酶链反应、免疫荧光染色技术检测犬心房肌细胞2型理阿诺受体在mRNA水平的表达和蛋白水平的表达和分布。结果与正常对照组比较,单纯房颤组犬2型理阿诺受体在mRNA和蛋白水平的表达明显低于正常对照组(P<0.05);在细胞质、细胞膜2型理阿诺受体分布均显著减少。结论房颤时心房肌细胞2型理阿诺受体表达下调,2型理阿诺受体可能不是心房肌细胞主要的钙信号调控的受体。     

聚乙烯醇水凝胶髓核的生物力学特性

目的 对一种新型水凝胶人工髓核的生物力学特性进行研究,为将来临床开展人工髓核置换手术提供科学依据。方法 采用7具新鲜标本的L_(4-5)脊柱功能单元进行生物力学实验,在轴向压缩、前屈后伸和左右侧弯等运动工况下,观察正常椎间盘、髓核摘除以及人工髓核植入3种状态下椎间盘高度、应变和位移的变化。结果 与正常椎间盘相比较,髓核摘除后椎间盘的高度和刚度降低,应变和位移加大(P<0.05)。而人工髓核植入后各项指标恢复正常(P>0.05)。结论 这种新型水凝胶人工髓核置换可纠正髓核摘除后的生物力学紊乱,有望进行临床应用。     

Medpor义眼座置入同期放置钛钉治疗眼眶凹陷畸形

目的探讨Medpor义眼座植入同期放置钛钉治疗眼球摘除术后眼眶凹陷畸形的有效性和可行性。方法眼球摘除同期置入Medpor义眼座患者80例，随机分为钛钉Ⅰ期置入组和Ⅱ期置入组，每组各40例。比较两组患者术中、术后出现的并发症和患者对义眼活动度和外观的满意程度。结果40例Ⅰ期置入患者术中有37例在术后2～6周时钛钉尾端自发性暴露，只有3例患者需要剪开结膜使钛钉尾端暴露。术后出现并发症者共37例，占46％：其中Ⅰ期置入组17例，Ⅱ期置入组加例，两者差异无统计学意义（P=0．501）。所有患者对其外观和活动度满意，其中Ⅰ期置入组非常满意36例，比较满意4例；Ⅱ期置入组非常满意34例，比较满意6例，两者差异无统计学意义（P=0．502）。结论Medpor义眼座置入同期放置钛钉治疗眼球摘除术后眼眶凹陷畸形，是一种安全有效的手术方法，同时患者避免了再次手术的痛苦。     

Antimicrobial susceptibility of respiratory Haemophilus influenzae strains isolated from pediatric respiratory tract infections

BACKGROUND: Haemophilus influenzae (H. influenzae) is the most frequent bacterial pathogen of respiratory tract infections in children. Detection of antimicrobial susceptibility of H. influenzae is necessary for institution of appropriate antibiotic treatments. METHODS: A total of 281 strains of H. influenzae isolated from sputum samples of 281 pediatric patients with respiratory tract infections were recruited for study. Antibiotic susceptibility was determined by assessing minimum inhibitory concentrations (MIC) of antimicrobial agents. MIC were measured by utility of Agar dilution susceptibility test. RESULTS: Of the total, 38 (13.5%) strains produced beta-lactamase (BLP), 56 (19.9%) strains were beta-lactamase non-producing, ampicillin resistant (BLNAR). The overall resistant proportion to ampicillin was 33.4%. The data indicated that sulbactam/ampicillin, cefotaxime, ceftriaxone and cefditoren are effective against BLP strains. In addition, a high prevalence of BLNAR H. influenzae strains was identified, with an overall isolation rate of 19.9%. Those strains mainly demonstrated intermediate level to ampicillin (ampicillin-MIC 相似文献   

医院感染常见细菌分布与耐药性分析

目的了解细菌分布及常见细菌的耐药性。方法回顾性分析某院2000—2004年临床标本分离的细菌及其耐药性监测结果。结果1439株细菌中，革兰阳性菌456株（31．69％），以凝固酶阴性表皮葡萄球菌为多，达206株（45．18％），其次为金黄色葡萄球菌92株（20．18％）；两种葡萄球菌的耐药率相似，对万古霉素耐药率均为0。革兰阴性菌983株，前5位依次为肠杆菌属346株（35．20％），克雷伯菌属164株（16，68％），铜绿假单胞菌155株（15．77％），埃希菌属101株（10．27％），变形杆菌属94株（9．56％）；前5位革兰阴性菌对常用抗菌药物的耐药性以半合成青霉索较明显，铜绿假单胞菌的耐药性较突出。结论应高度重视细菌变迁和耐药性监测，提高抗菌药物合理应用水平。     

钛种植体－羟基磷灰石早期修复犬下颌骨缺损与骨结合的实验研究

本研究对钛种植体－羟基磷灰石（Ｔｉ－ＨＡ）在早期修复下颌骨缺损中与骨结合的界面形态进行了扫描电镜和Ｘ线能谱观察分析。通过对９只健康狗下颌骨缺损区植入Ｔｉ－ＨＡ２、６及１２周后Ｔｉ－ＨＡ／宿主骨界面及Ｔｉ／ＨＡ界面的扫描电镜观察和Ｘ线能谱分析，结果表明Ｔｉ－ＨＡ植入骨缺损区，不引起正常的骨矿化过程改变，与宿主骨形成骨性结合；Ｔｉ／ＨＡ界面有新骨形成；扫描电镜观察和Ｘ线能谱分析在研究骨缺损修复过程中不同阶段的组织成份的变化是一个重要手段。     

Paucity of glutaminase-immunoreactive nonpyramidal neurons in the rat cerebral cortex.

Glutaminase has been considered to be a synthesizing enzyme of transmitter glutamate in pyramidal neurons of the cerebral cortex. In the present study, an attempt was made to examine with a double immunofluorescence method whether or not nonpyramidal neurons of the cerebral cortex are immunoreactive for glutaminase. Glutaminase was stained with mouse anti-glutaminase IgM and FITC-labeled anti-[mouse IgM] antibody. In the same section, parvalbumin (PA), calbindin (CB), choline acetyltransferase (CAT), vasoactive intestinal polypeptide (VIP), corticotropin releasing factor (CRF), cholecystokinin (CCK), somatostatin (SS), or neuropeptide Y (NPY) was visualized as a marker for nonpyramidal neurons with an antibody to each substance, biotinylated secondary antibody and Texas Red-labeled avidin. Virtually no glutaminase immunoreactivity was seen in PA-, CB-, CAT-, VIP-, CRF-, CCK-, SS-, or NPY-immunoreactive neuronal perikarya in the neocortex and mesocortex (cingulate and retrosplenial cortices), although it was detected in a few PA-, CB-, VIP-, CCK-, SS-, or NPY-immunoreactive nonpyramidal neurons in the piriform, entorhinal, and hippocampal cortices. PA- and CB-positive neurons have been reported to constitute the major population of GABAergic neurons in the cerebral cortex. Thus, the present results, together with the previous reports, suggest that most GABAergic, cholinergic and peptidergic nonpyramidal neurons in the neo- and mesocortex do not contain glutaminase.