Neural network models for the gaze shift system in the superior colliculus and cerebellum.

We investigate the role that the superior colliculus (SC) and the cerebellum might play in generating gaze shifts. The discharge of cells in the intermediate layers of the SC is tightly linked to the occurrence of saccades. Many studies have demonstrated that the cerebellum is involved in both eye and head movements. When the head is unrestrained, large amplitude gaze shifts are composed of coordinated eye and head movements. In this study, we propose that the gaze saccades system is controlled by a feedback loop between the SC and the cerebellum. The SC only encodes retinal coordinates and controls the eye displacement (to move the fovea to the target), while the cerebellum deals with the gaze programming and controls the head displacement. When a target appears in space, the buildup cells within the SC decode the target signal in the retina before the saccade onset, and input the signal of the gaze displacement to the cerebellum. The cells in the cerebellum vermis encode the initial position of the eye in the orbit. The gaze displacement is decomposed into the head amplitude and the eye amplitude within the cerebellum. There are two output signals from the cerebellum. One signal controls the head movement. The other is projected back to the SC, and forms a component of the saccade vector to control the eye movement. The sum of the vectors provided by the cerebellum and the vector provided by the burst cells in the SC indicates the direction and the amplitude of the desired movement of the eye during the saccade. We propose a cerebellum model to predict the displacements of the eye and head under the condition that the position of the target signal in the retina and the initial position of the eye in the orbit are known. The results from the model are close to that observed physiologically. We conclude that before gaze shift onset, the cerebellum may play an important role in decomposing the gaze displacement into an eye amplitude and head amplitude signal.     

149例围产儿死亡原因分析

目的：探讨围产儿死亡原因及降低围产儿死亡率的措施。方法：对1994年1月－2001年12月在我院住院分娩的149例死亡围产儿的临床资料进行回顾性分析。结果：围产儿死亡率为22．74‰，死胎率为9．77‰，死产率为3．36‰，早期新生儿死亡率为9．62‰，占42．28％。围产儿死亡原因：缺氧占47．65％，早产占21．15％，出生缺陷占12．08％。结论：加强孕期保健、规范系统产前检查及监护、积极预防治疗妊娠并发症、防治早产、实施正确的新生儿窒息复苏方法、建立NICU等是降低围产儿死亡率的重要环节。     

北京市城乡乳母的营养状况、乳成分和婴儿摄入母乳量及生长发育的关系——Ⅲ母乳的脂质分析

本文报导了1983～1984年北京市城区(宣武区),近郊区(西红门)和远郊区(大皮营)母乳脂质成分的测定结果,并结合乳母营养状况给予评价。 共测定了207例母乳比重,平均范围在1.018～1.023之间;测定了216例母乳的脂肪含量(g/100g乳),城区平均值为3.78,近郊区为3.31,远郊区为3.08,城区的显著较高;测定了194例母乳胆固醇含量,初乳的最高(23.4mg/100g乳),以后逐渐减低,到第三个月后达稳定水平(约10mg/100g乳),三个调查点的情况相同,测定了221例母乳的脂肪酸组成,其主要成分为油酸(29～37％),棕榈酸(17～25％)和亚油酸(12～25％),远郊区母乳中所含的必需脂肪酸显著较高。 统计分析证明三个地区的乳脂含量(％)与乳胆固醇含量(mg/100g乳)间有显著性相关(P<0.01);188例乳母的膳食脂肪摄入量(g/日或％kcal)与乳脂含量间也有显著性相关(P<0.05),此结果表明,北京城乡母乳的乳脂含量可能受膳食脂质与量的影响,其脂肪酸组成的特点是亚油酸含量高,反映了我国人民以素食为主的饮食习惯。乳中的必需脂肪酸供给量可满足婴儿所需,胆固醇供给量为70～85mg/d,可作为同龄婴儿自母乳摄入量的参考。     

中枢神经系统白血病血清神经元特异性烯醇酶测定的临床意义

目的 探讨血清神经元特异性烯醇酶与中枢神经系统白血病之间的关系。方法 对确诊的30例急性白血病患者及匹配的正常人的血清神经元特异性烯醇酶进行测定。结果 中枢神经系统白血病组血清神经元特异性烯醇酶含量21．92 7．5μg/L均明显高于白血病组、对照组，差异有显著性。结论 血清神经元特异性烯醇酶可作为反映中枢神经系统白血病病情的生化指标。     

医院感染流行病学监测分析

介绍了我院１９９３年７月１日～１９９３年１２月２０日出院的１０３１例病人医院感染病率的监测分析，半年中感染率为８．４％，妇产科疗区发病率高于外科疗区，感染部位以泌尿道、下呼吸道、手术伤口为最多，侵袭性操作及易感因素引起的感染在感染病例中分别占４０．２％和５９．８％。     

Pancreas divisum with early pancreatic cancer--presenting as chronic obstructive pancreatitis.

A 61-year-old man experienced four bouts of pancreatitis in 1 year. Detailed history taking and a series of examinations, including sonography, computed tomography scan, and endoscopic retrograde cholangiopancreatography (ERCP), revealed pancreas divisum on the first admission. He was treated conservatively. However, repeated ERCP on the fourth admission, 1 year later, showed a small filling defect in the tail of the pancreatic duct. A distal pancreatectomy was carried out. Pathological studies revealed a small papillary adenocarcinoma (1.5 x 1.0 x 0.5 cm) confined to the pancreatic duct grossly with minimal parenchymal invasion microscopically. He has been free from cancer and pancreatitis for 13 months since the operation.     

ICR 小白鼠脏器中铜,锌锰含量

对40只正常成年远交系 ICR 小白鼠的主要脏器,用 WFX—Ⅱ型双光束原子吸收分光光度计测定了各脏器中铜、锌、锰含量.结果表明,主要脏器中铜、锌、锰含量大小顺序不一,铜含量最多的脏器是心,锌、锰含量最多的脏器是肝,在雌雄之间均无显著性差异.     

急性苯中毒对小鼠末梢血象和骨髓细胞构成的影响

取３２只２～３个月的ＢＡＬＢ／Ｃ小白鼠，随机分为４组，每组８只，第１组为对照组，其余３个组为实验组，实验组小白鼠左腿皮下注射苯０．３ｍｌ（１５ｍｌ／ｋｇ体重）．注射后分别于２４ｈ，４８ｈ，７２ｈ脱颈处死。观察中毒前、后末梢血象、骨髓细胞、骨髓细胞构成的变化。结果表明，苯中毒时骨髓变化先于末梢血象的变化，骨髓的病变为造血细胞变性、坏死，大量毛细血管扩张、充血，骨髓细胞构成降低，而且骨髓细胞构成中细胞成分降低早于外周血粒细胞减少。     

Thrombopoietin in postoperative thrombocytopenia following living donor hepatectomy.

Thrombocytopenia is a frequent finding following living donor hepatectomy. It appears more pronounced in right graft donors than in left graft donors. This study analyzed postoperative thrombocytopenia in 20 living liver donors and examined the change of endogenous thrombopoietin (TPO) in its recovery. Platelet count, TPO level, fibrinogen degradation product (FDP), and D-Dimer were measured before surgery and on postoperative days (PODs) 1, 2, 3, 5, 7, and 14. Concurrently, liver and spleen volumes were calculated by computed tomography. Platelet count on POD 3 was significantly lower in right graft donors than in left graft donors (13.0 +/- 3.7 x 10(4)/microL vs. 16.8 +/- 4.0 x 10(4)/microL, P = 0.039) but recovered by POD 7 in all donors. Postoperative elevations of FDP and D-Dimer were significantly higher in right graft donors than in left graft donors. TPO level rose immediately after surgery, peaked on POD 5 in left graft donors and on POD 7 in right graft donors, and fell nearly to preoperative levels by POD 14. Postoperative TPO level per liver volume was significantly higher in right graft donors than in left graft donors. In conclusion, thrombocytopenia following living donor hepatectomy resolved within the first week regardless of graft type and was mainly associated with increasing consumption of circulating platelets, possibly due to intrahepatic and splenic congestion. With a reduced number of circulating platelets, TPO level rapidly increases. Also, with reduced consumption of platelets related to recovery from surgery, thrombocytopenia should resolve. As a consequence, TPO level would be expected to fall.