Role of tyrosine kinase signaling for beta-cell replication and survival

Diabetes mellitus is commonly considered as a disease of a scant beta-cell mass that fails to respond adequately to the functional demand. Tyrosine kinases may play a role for beta-cell replication, differentiation (neoformation) and survival. Transfection of beta-cells with DNA constructs coding for tyrosine kinase receptors yields a ligand-dependent increase of DNA synthesis in beta-cells. A PCR-based technique was adopted to assess the repertoire of tyrosine kinases expressed in fetal islet-like structures, adult islets or RINm5F cells. Several tyrosine kinase receptors, such as the VEGFR-2 (vascular endothelial growth factor receptor 2) and c-Kit, were found to be present in pancreatic duct cells. Because ducts are thought to harbor beta-cell precursor cells, these receptors may play a role for the neoformation of beta-cells. The Src-like tyrosine kinase mouse Gtk (previously named Bsk/Iyk) is expressed in islet cells, and was found to inhibit cell proliferation. Furthermore, it conferred decreased viability in response to cytokine exposure. Shb is a Src homology 2 domain adaptor protein which participates in tyrosine kinase signaling. Transgenic mice overexpressing Shb in beta-cells exhibit an increase in the neonatal beta-cell mass, an improved glucose homeostasis, but also decreased survival in response to cytokines and streptozotocin. It is concluded that tyrosine kinase signaling may generate multiple responses in beta-cells, involving proliferation, survival and differentiation.     

Octreotide in the treatment of thoracic duct injuries

Anecdotal reports support the use of octreotide in the treatment of traumatic thoracic duct injuries and chylothorax, but no prospective studies have proved its efficacy. We evaluated the effects of octreotide in treating thoracic duct transection in a canine model. Eight mongrel dogs (27.8+/-5.1 kg) were fed one pint of 10.5 per cent milkfat 2 hours before operation. Through a left supraclavicular neck incision, the thoracic duct was identified and transected, producing free flow of chyle. A quarter-inch drain was tunneled subcutaneously from the wound and attached to closed suction. After wound closure dogs were randomized to a control group (n = 4) receiving sham injections of saline subcutaneously three times per day, or a treatment group (n = 4) given 3 microg/kg octreotide three times per day. Postoperatively all dogs were fed a standard low-fat (5-7%) crude fat diet. Drain output was measured each day, and on odd-numbered postoperative days the drainage was analyzed for cholesterol, triglycerides, albumin, and total protein. Fistula closure was defined as drainage <10 ml/24-hour period. Treated dogs achieved fistula closure significantly faster than controls: 3.5+/-1.3 days versus 7.8+/-1.0 days (P = 0.0037). Whereas equivalent amounts of drainage occurred on the day of surgery and on postoperative day one in both groups, by postoperative day 2 the treatment group had significantly less drainage over 24 hours: 63+/-69 ml versus 195+/-79 ml (P = 0.046); this significant difference persisted through postoperative day 5 when drainage began to decrease in the control group. No significant differences between groups were seen in levels of cholesterol, triglycerides, albumin, or protein in the drainage at any time point. We conclude that octreotide is effective in treating thoracic duct injury, leading to an early decrease in drainage and early fistula closure. The mechanism for this effect remains to be clarified.     

The future of criminal violence: juveniles tried as adults

Juveniles tried as adults (JTA) represent a select and small subsample of juvenile offenders. This study seeks to provide a profile of habitually violent JTAs transferred to the adult penal system and to compare them with their adult counterparts. Twenty-nine incarcerated violent male juveniles tried as adults were compared with a sample of 27 incarcerated violent male offenders across demographic, neuropsychological, criminal history, psychopathy, and substance abuse variables. The JTAs were characterized by a high rate of gang membership (96%), substance abuse (alcohol, marijuana, and phenylcyclidene), and use of guns. In the juvenile sample, 65 percent used guns in violence not leading to arrest, and 93 percent used guns in a violent crime leading to arrest. Juvenile offenders were similar to their adult counterparts in patterns of criminality, although adult offenders had higher psychopathy scores. Both groups revealed generally intact neuropsychological functioning with the exception of a higher rate of perseverative responses in the adult sample. The results are discussed in terms of the implication of the degree of violence in a young offender population.     

早产儿瘦素质量浓度与早期静脉营养及生长发育相关性探讨

目的探讨瘦素质量浓度与早期静脉营养及生长发育的关系。方法新疆医科大学第一 附属医院新生儿科于2005 01—2006 02，将收治的86例早产适于胎龄儿用随机数字表法分为观察组(早期微量喂养同时辅助胃肠外营养组)45 例和对照组(单纯早期微量喂养组)47例，分别测定脐血及第7天血清瘦素质量浓度，同时监测营养状况和生长发育指标，并作对比分析。结果 (1)观察组与对照组脐血瘦素质量浓度分别为(4.6±3.7)ng/mL、(4.8±2.2)ng/mL，生后第7天两组瘦素质量浓度分别为(4.3±2.2)ng/mL、(3.1 ±1.7)ng/mL。对照组第7天血清瘦素质量浓度明显低于脐血(P<0.05)，而观察组其差异无统计学意义(P>0.05)。(2)脐血瘦素质量浓度与出生体 重、胎龄成正相关(r=0.56、r=0.67)。(3)观察组第7天热卡及蛋白质摄入量、血清瘦素质量浓度、皮褶厚度变化值与对照组相比，差异有统计 学意义(P<0.05)。结论对早产儿应尽早喂养，同时需要胃肠外营养作为肠内营养的补充。瘦素可作为新生儿营养效果判定的实验室指标之一。     

针刺足三里对对乙酰氨基酚诱发大鼠肝损伤的影响

目的：观察针刺足三里对对乙酰氨基酚（ APAP）多次给药诱发大鼠肝损伤血清转氨酶和肝脏病理学变化的影响,探讨针刺对药源性肝脏损伤的保护作用。方法75只SD大鼠随机分为正常对照组（ NC组）、APAP模型1组（ APAP1组）、针刺＋APAP 模型1组（ ZC＋APAP1组）、 APAP模型2组（ APAP2组）、针刺＋APAP模型2组（ ZC＋APAP2组）。 APAP1组和APAP2组大鼠每天分别按体重灌胃给予APAP 300、600 mg／kg;APAP1组和APAP2组大鼠每天分别按体重灌胃给予 APAP 300、600 mg／kg后即刻针刺其后肢足三里穴20 min;NC组灌胃给予相同体积剂量的生理盐水。各组大鼠连续给药或针刺14 d后,检测血清转氨酶活性和检查肝脏病理学变化情况。结果与NC组相比,ZC＋APAP1组、APAP2组和ZC＋APAP2组大鼠血清AST和ALT活性均显著升高（P＜0．05或P＜0．01）;与APAP1组、APAP2组相比, ZC＋APAP1组、ZC＋APAP2组大鼠血清AST、ALT活性均显著性升高（P＜0．05或P＜0．01）。 APAP1组和ZC＋APAP1组间肝脏病理学改变,差异无统计学意义（P＞0．05）,而APAP2组与ZC＋APAP2组肝脏病理学改变显著（P＜0．05）。结论针刺足三里促进APAP诱导大鼠血清AST和ALT活性的升高;但肝脏病理组织学检查结果显示,针刺足三里对APAP多次给药诱发大鼠肝损伤具有一定的保护作用。