A study on the role of the family and other risk factors in HCV transmission

Background/aims: To understand the intrafamilial transmission and the existing risk factors related to HCV infection in subjects confirmed anti-HCV positive, their sexual partners and household contacts in Friuli, North-East Italy. Methods: We enrolled all the subjects that were consecutively identified as HCV positive during routine laboratory testing in six health districts and their household contacts. From each subject we obtained a blood sample, demographic data and a medical history including the existence of risk factors for HCV. Antibodies to HCV were detected employing a commercially available second-generation enzyme immunoassay (EIA); positive serum specimens were retested using a second-generation recombinant immunoblot assay (RIBA-2). Results: We recruited 743 subjects, 229 first subjects identified as HCV positive and 514 household contacts. There were no statistically significant differences in positivity among household contacts. Analysing intracouple transmission we found no significant differences by gender in couples both with and without parenteral risk factors. We found, both with univariate and multivariate analysis, as statistically significant risk factors in all the subjects: age older than 60, blood transfusions (particularly those performed before 1984), surgical procedures such as abortion and/or uterine curettage, history of HBV infection, intravenous drug use, and tattooing. Conclusions: Our results stress the low relevance of sexual transmission in the intrafamilial context, the importance of abortion and/or uterine curettage, the important role of blood transfusions in the past, a higher prevalence of HCV infection within a household of a HCV positive member compared to all other existing data in the area.     

NMDA receptor-independent mechanisms responsible for the rate of rise of cumulative depolarization evoked by trains of dorsal root stimuli on rat spinal motoneurones

The mechanisms responsible for the rate of rise (RR) of cumulative depolarization induced by dorsal root stimulus trains were investigated with intracellular recordings from motoneurones of the rat isolated spinal cord. The NMDA receptor antagonists CPP or APV depressed the cumulative depolarization but not its RR which could still be fast enough to elicit action potential wind-up. RR size was correlated with a slow synaptic potential (detected in CPP or APV solution) with which it shared similar voltage dependence. The NK1 antagonist SR 140333 depressed cumulative depolarization, RR and slow synaptic potentials. It appears that the RR (and the ability to express wind-up) was determined by summation of slow synaptic potentials partly mediated via activation of NK1 receptors.     

Donor to host transmission of disease via corneal transplantation

A literature search was conducted to report all cases of documented transmission of infectious diseases from donors to recipients of corneal transplants. Fourteen such cases have been reported. There is no experimental or clinical evidence to suggest the transmissions of either hepatitis or syphilis via corneal grafting. Available evidence regarding a number of neurologic and other disorders in which a slow virus etiology has been implicated were reviewed. On the basis of this review, we are able to draw certain conclusions and guidelines for selection or rejection of donor material for transplant surgery.     

Sensory Excitatory Postsynaptic Potentials Mediated by NMDA and non-NMDA Receptors in the Thalamus in vivo

Excitatory amino acid neurotransmitters, such as l-glutamate, act at several receptors in the brain, which are sometimes referred to as N-methyl-d-aspartate (NMDA) and non-NMDA receptors. Extensive in vitro work indicates that both NMDA receptors and non-NMDA receptors contribute to excitatory postsynaptic potentials (epsps). The contribution of NMDA receptors to epsps in vivo under physiological conditions is, however, almost unknown. The receptors that mediate the epsps evoked in thalamic relay cells by natural stimulation of sensory afferents have been investigated in anaesthetized rats, and we report the first pharmacological characterization of an excitatory amino acid receptor-mediated epsp in vivo involving both non-NMDA receptors and, in particular, NMDA receptors.     

The extracellular matrix molecule tenascin-R and its HNK-1 carbohydrate modulate perisomatic inhibition and long-term potentiation in the CA1 region of the hippocampus

Perisomatic inhibition of pyramidal cells regulates efferent signalling from the hippocampus. The striking presence of HNK-1, a carbohydrate expressed by neural adhesion molecules, on perisomatic interneurons and around somata of CA1 pyramidal neurons led us to apply monoclonal HNK-1 antibodies to acute murine hippocampal slices. Injection of these antibodies decreased GABAA receptor-mediated perisomatic inhibitory postsynaptic currents (pIPSCs) but did not affect dendritic IPSCs or excitatory postsynaptic currents. The decrease in the mean amplitude of evoked pIPSCs by HNK-1 antibodies was accompanied by an increase in the coefficient of variation of pIPSC amplitude, number of failures and changes in frequency but not amplitude of miniature IPSCs, suggesting that HNK-1 antibodies reduced efficacy of evoked GABA release. HNK-1 antibodies did not affect pIPSCs in knock-out mice deficient in the extracellular matrix molecule tenascin-R which carries the HNK-1 carbohydrate as analysed by immunoblotting in synaptosomal fractions prepared from the CA1 region of the hippocampus. For control, HNK-1 antibody was applied to acute sections of mice deficient in the neural cell adhesion molecule NCAM, another potential carrier of HNK-1, and resulted in decrease of pIPSCs as observed in wild-type mice. Reduction in perisomatic inhibition is expected to promote induction of long-term potentiation (LTP) by increasing the level of depolarization during theta-burst stimulation. Indeed, LTP was increased by HNK-1 antibody applied before stimulation. Moreover, LTP was reduced by an HNK-1 peptide mimic, but not control peptide. These results provide first evidence that tenascin-R and its associated HNK-1 carbohydrate modulate perisomatic inhibition and synaptic plasticity in the hippocampus.     

人结直肠癌平滑肌组织毒蕈碱受体特性的变化

随着受体理论和研究技术的发展 ,人们开始从受体的变化去探寻疾病发生和发展的根源 ,并从受体水平诊治疾病。最近人们发现ＭＡＣｈ Ｒ与肿瘤之间关系密切。一方面 ,ＭＡＣｈ Ｒ过度活化可导致细胞增殖、恶性转化及肿瘤发生[1] ;另一方面 ,在肿瘤状态下ＭＡＣｈ Ｒ的特性也发生变化。本文主要探讨肿瘤状态下ＭＡＣｈ Ｒ特性的变化。1　材料与方法1.1　临床资料　结直肠癌病人 10例 ,男 6例 ,女 4例。中国医科大学附属第一医院肿瘤科提供。1.2　标本采集　结直肠癌患者手术切除的标本 ,分别取癌、癌旁及正常组织各一块。癌旁组织取距癌灶约 2…     

妊娠晚期人类小DNA病毒B19感染情况,母婴传播及与早产或小于胎龄儿关系的研究

为了解妊娠晚期人类小ＤＮＡ病毒Ｂ１９（ＨＰＶＢ１９）感染情况、母婴传播及与早产或小于胎龄儿的关系，将１０４例母亲及其新生儿分成两组，试验组包括１９例早产儿、３２例小于胎龄儿及其母亲；对照组包括５３例正常新生儿及其母亲。采用聚合酶链反应技术（ＰＣＲ）检测母血、脐血和胎盘组织ＨＰＶＢ１９ＤＮＡ；用鼠抗Ｂ１９单克隆抗体和Ｂ１９联合抗原（ＶＰ１＋ＶＰ２）建立了捕获式ＥＬＩＳＡ法检测母血和脐血ＨＰＶＢ１９特异性ＩｇＭ抗体。结果：１０４例母血中，ＨＰＶＢ１９ＩｇＭ阳性２例（１．９％），１０４例脐血中阳性３例（２．９％）。在母血、脐血及胎盘组织各１０４例中检出ＨＰＶＢ１９ＤＮＡ阳性分别为６例、４例、６例。因此试验组５１对母婴共１０２例中６例有ＨＰＶＢ１９感染（５．９％）；对照组５３对母婴共１０６例中２例有ＨＰＶＢ１９感染（１．９％）。两组Ｂ１９感染率差异无显著意义。提示：在北京地区，妊娠晚期存在Ｂ１９急性感染，应引起重视；Ｂ１９感染与早产或小于胎龄儿的发生可能不相关；新生儿Ｂ１９感染是通过胎盘传播的。对有Ｂ１９感染证据的新生儿进行随访及研究如何阻止胎盘传播很重要。     

我对SCSI的认识

简要地描述了SCSI的性能、用途以及使用的注意事项     

Multiple representations of information in the primary auditory cortex of cats. II. Stability and change in early (<32 ms), rapid components of activity after conditioning with a click conditioned stimulus

Activity was recorded from single units of the A(I) cortex of awake animals to identify early (<32 ms) components of the population response to a 70 dB click and establish if they changed after using the click as a CS for conditioning. A 70 dB hiss was used as a discriminative stimulus. Responses to these stimuli were compared before and after a forward order of pairing that produced conditioning and a backward order of pairing that produced weak sensitization (backward conditioning). Averages of discharges in 2 and 4 ms bins distinguished primary (8-12 ms) from secondary (12-16 ms) temporal components of response to the click, and confirmed that the onset of the response was shorter in A(I) (8 ms, mean of 647 units) than in the adjacent, A(II) cortex (16 ms, mean of 95 units). (All times include a 1.6 ms transmission delay in sound arrival.) Primary and secondary components of A(I) responses to click did not change uniformly after changes in behavioral state, and were affected differently by both conditioning and backward conditioning. The percentage of cells with onsets of response to the click at secondary latencies (and to the hiss at tertiary latencies) increased after backward conditioning but not after conditioning, as did the magnitude of activity in response to the click. (The latter had a lesser degree of increase after conditioning.) The primary response to the click did not show these increases. The non-uniform changes suggested that temporal processing of the click was conducted differently in the 8-12 ms post stimulus period than in the 12-16 ms period. Within the total population of cells, it was possible to identify a small subgroup (13%) of highly auditory-responsive units that showed an increased primary response to the click as a CS selectively after conditioning and not after backward conditioning. The secondary component of response in these cells increased after both conditioning and backward conditioning. The percentages of cells responding to the click and hiss at primary latencies did not change significantly after conditioning, even in the subgroup of highly responsive cells. The results characterize differently timed components of rapid responses to acoustic stimuli in the A(I) cortex, disclose significant temporal differences in primary, secondary and tertiary information processing that affect the representations of the transmitted acoustic message across different behavioral states, and find one representation in a small subgroup of cells that supports the hypothesis that cells of the A(I) cortex have a selectively potentiated response to the CS after conditioning.