胰腺外科学分段的解剖学基础及其意义

目的：为胰腺外科学分段提供解剖学基础。方法：在６４具灌注标本和４具铸型标本上观察胰内动脉分布、吻合。结果：头由胰十二指肠上动脉和胰十二指肠下动脉供血；颈为一乏血管区；体和尾由胰背动脉、胰支、胰大动脉和胰尾动脉供血。结论：全部胰腺可分为左侧段和右侧段     

Tyrosine kinase inhibition reduces i f in rabbit sinoatrial node myocytes

 We studied pacemaker current (i _f), the inward current activated by hyperpolarization in rabbit sinoatrial (SA) node myocytes, with the permeabilized-patch-clamp technique. The tyrosine kinase inhibitors genistein (50 μM) or herbimycin A (35 μM) reduced the amplitude of i _f in response to step hyperpolarizations in the diastolic range of potentials. A two-step voltage-clamp protocol revealed that the reduction in i _f is due to a decrease in maximal i _f conductance. The observed effects are due to tyrosine kinase inhibition since an inactive analog of genistein did not reduce i _f. To further examine the mechanism of action, we added 2 mM chlorophenylthio cAMP (CPTcAMP, a membrane-permeant cAMP analog) to the bathing Tyrode, which increased i _f. Genistein still reduced i _f in the presence of CPTcAMP. This suggests that the pathway mediating the actions of tyrosine kinase inhibition on i _f is independent of cAMP- or protein-kinase-A-mediated phosphorylation. Received: 28 January 1997 / Received after revision: 21 April 1997 / Accepted: 22 April 1997     

小鼠胸腺基质细胞株中细胞多核化现象探讨

在建立小鼠胸腺基质细胞株时发现小鼠胸腺基质细胞株ＭＴＳＣＢ和ＭＴＳＣＣ自发产生多核细胞及单核巨细胞，对上述细胞进行了非特异性酯酶（ＮＳＥ）、酸性磷酸酶（ＡｃＰ）和琥珀酸脱氢酶（ＳＤＨ）反应，多核细胞及单核巨细胞的ＮＳＥ、ＡｃＰ和ＳＤＨ活性均强于单核小细胞。在ＭＴＳＣＢ中多核细胞的百分数为１．１％；ＭＴＳＣＣ中多核细胞为０．６％，实验中对一核细胞和多核细胞出现的百分数与Ｐｏｉｓｓｏｎ分布的理论频率进     

鼻腔外侧壁的应用解剖

在60个头颅(男34,女26)120侧鼻腔外侧壁上观察测量了以下诸结构,结果:上鼻甲长15.9±2.9mm,宽4.7±1.1mm;中鼻甲长36.5±3.3mm,宽10.4±3.4mm;下鼻甲长42.7±3.6mm,宽12.3±1.7mm;半月裂长16.6±2.3mm;钩突长20.7±3.1mm,宽4.3±1.7mm;筛泡长19.2±4.1mm,高6.5±2.1mm,另外还测量了前鼻棘距上述各结构的距离.     

Two cis-acting elements in negative RNA strand of Hepatitis C virus involved in synthesis of positive RNA strand in vitro

Sequences at the 3'-ends of both positive and negative strands of Hepatitis C virus (HCV) RNA harbor cis-acting elements required for RNA replication. However, little is known about the properties of the negative RNA strand as a template for the synthesis of positive RNA strand. In this study, a purified recombinant HCV RNA-dependent RNA polymerase (RdRp) was used to investigate the synthesis of positive RNA strand using the 3'-terminal region of negative RNA strand ((-)3'T RNA) as template. A mutagenesis analysis was performed to evaluate the role of the 3'-proximal stem-loop and the first 3'-cytidylate (3'C) of the negative RNA strand in the synthesis of the positive RNA strand. A negative RNA strand of wild type (wt) HCV as template was able to direct the synthesis of a full-length positive RNA strand. Deletion of the 3'-proximal stem-loop resulted in an approximately 90% decrease in RNA synthesis. Disruption of the 3'-proximal stem-loop structure by nucleotide substitutions led to a 70-80% decrease in RNA synthesis. However, the restoration of the stem-loop by compensatory mutations in the stem region restored also the RNA synthesis. Likewise, the deletion or substitution of the first 3'C by guanylate (G) led to a 90% decrease in the RNA synthesis; while the substitution by adenylate (A) or uridylate (U) resulted in a 60-80% decrease in the RNA synthesis only. These findings demonstrate that the 3'-proximal stem-loop and the first 3'C of the negative RNA strand of HCV are two cis-acting elements involved in the synthesis of the positive RNA strand.     

Congenital lactic acidosis: evaluation of the properties of the a199t natural variant of human pyruvate dehydrogenase e1alpha by in vitro mutation

One cause of congenital lactic acidosis is a mutation in the E1 alpha-subunit of the pyruvate dehydrogenase multienzyme complex. Little is known about the consequences of these mutations at the enzymatic level. Here we study the A199T mutation by expressing the protein in Escherichia coli. The specific activity is 25% of normal and the K(m) for pyruvate is elevated by 10-fold. Inhibitors of lactate dehydrogenase might be a useful therapy for patients with such mutations.     

肝素酶与肿瘤转移

肿瘤细胞实现扩散、转移 ,与免疫细胞趋向炎症反应区一样 ,必须首先穿越由细胞外基质和基底膜组成的屏障。该屏障主要由两种成分构成 :一是结构蛋白 ,包括胶原、层粘素、纤维结合素和玻璃体结合素等 ;二是糖氨聚糖 ,其主要成分是硫酸乙酰肝素蛋白多糖 (ｈｅｐａｒａｎｓｕｌｆａｔｅｐｒｏｔｏｇｌｙｃａｎ ,ＨＳＰＧ)。ＨＳＰＧ主要由一个蛋白核心和数个与之共价连接的线性硫酸乙酰肝素 (ｈｅｐａｒａｎｓｕｌｆａｔｅ ,ＨＳ)侧链组成[1] 。起初认为 ,结构蛋白的破坏是肿瘤细胞转移的决定性步骤 ,因此 ,在过去的 10多年中 ,研究兴趣大多集…     

Multicenter analytical evaluation of an automated immunoassay for total plasma homocysteine

A fully automated immunoassay for total plasma homocysteine assay was evaluated at four centers. To measure total homocysteine, oxidized forms of homocysteine in serum and plasma were reduced by dithiothreitol and assayed by a competitive fluorescence polarization technique. The assay had within-run precision from 0.9 to 3.0% and total precision from 2.8 to 4.1% for control materials with homocysteine concentrations of approximately 7, 12.5, and 25 micromol/L, a sensitivity of 0.35 micromol/L, good parallelism upon dilution, and analytical recovery ranging from 97.4 to 103.8%. The immunoassay correlated with four different HPLC assays for homocysteine, yielding a slope of 0.98, an intercept of -0.19 micromol/L, and a correlation coefficient of 0.966 for 440 paired samples. The reference range, determined with plasma samples from 609 males and 600 females, yielded a mean of 9.17+/-2.86 micromol/L, with a central 95% range of 4.78-15.43 micromol/L. The immunoassay is a suitable alternative to HPLC and may be useful in screening persons with high risk of coronary artery disease.     

The selachian terminal nerve]

In order to clarify morphology and function(s) of the terminal nerve, gross examinations of the nerve were carried out in 9 species of selachians. The terminal ganglion was observed light- and electron-microscopically. FMRF-amide immunoreactivity of the terminal nerve was also examined in some species. The results were as follows: 1) The terminal nerve was divided into peripheral and central branches by interposed ganglion(s). Macroscopically, the peripheral branch appeared from an area between the nasal sac and the olfactory bulb. The central branch entered the telencephalon from either the rostral, dorsal, or ventral surface. The position seemed to differ from species to species. 2) The terminal nerve showed great species differences and individual variations in the macroscopic morphology, such as number and course of the peripheral branch, position, size and number of ganglia, and telencephalic areas where the central branch entered. Even in the same individual, there was a difference in left and right sides. 3) According to general histology, the ganglion was encapsulated and had no direct connection with the telencephalon through the capsule, even when the ganglion was situated on the telencephalon. The Bodian preparations showed that most ganglion cells were unipolar, and a few were bipolar or pseudounipolar. 4) All ganglion cells and the processes were FMRF-amide immunoreactive. Immunoreactive fibers of the central branch terminated in the septal and preoptic areas. FMRF-amide immunoreactive cells were also found in the olfactory nerves or the septal area of the telencephalon in some species. These neurons were thought to be ectopic ganglion cells. 5) Neuronal somata and the axons in the ganglion contained large dense cored vesicles.(ABSTRACT TRUNCATED AT 250 WORDS)     

Recessive inheritance of a high number of sodium pump sites

The number of sodium pump sites on erythrocytes was measured on 1,847 individuals in 80 Utah kindreds ascertained through probands with cardiovascular disease. Likelihood analysis supported recessive inheritance of high pump number. The major locus explained 14.0% of the variance in pump number; polygenic inheritance explained another 63.4%. Homozygotes for the recessive allele occurred with a frequency of 1.74% and had a mean pump number estimated as 566.0 sites/red blood cell (RBC) versus a mean of 312.2 sites/RBC for the other genotypes. Young individuals with the high pump number genotype were leaner, and older adults with the high pump number genotype were heavier. Diabetes and early hypertension were more prevalent in women with the high pump number genotype. Although not significant, obesity in adults of both sexes and early coronary heart disease in men were more prevalent in individuals with the high pump number genotype.