Studies on transmission of hepatitis C virus from mother-to-child in the perinatal period

Summary To elucidate whether breast milk, vaginal discharge and contamination with maternal blood at birth are possible routes of mother-to-child transmission of hepatitis C virus (HCV), we examined HCV RNA in the cord and peripheral blood of infants, and in the blood, vaginal discharge, and breast milk of anti-HCV seropositive mothers. From July 1991 to July 1992, we studied 20 healthy pregnant women, who were seropositive with the Ortho anti-HCV EIA, and their infants. Using a sensitive nested polymerase chain reaction (nested PCR), we investigated the presence or absence of hepatitis C virus in the above-mentioned specimens. Moderate elevation of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was observed in only one woman in the first and third trimesters. The nested PCR and subsequent Southern hybridization detected 0.5–5.5 copies of HCV c-DNA. HCV RNA was detected in 17/20 blood samples (85%), 7/14 vaginal discharge samples (50%) and 4/10 cord blood samples (40%). However, no HCV RNA was identified in the peripheral blood of infants or breast milk. The mother-to-child transmission of HCV at delivery or via breast milk does not appear to contribute much to maintaining the global HCV reservoir.     

Vertical human immunodeficiency virus-1 infection: Involvement of the central nervous system and treatment

Involvement of the central nervous system (CNS) contributes substantially to morbidity and mortality of vertical infection with the human immunodeficiency virus (HIV)-1. The clinical spectrum ranges from minor developmental disabilities to severe and progressive encephalopathy. Progression of the disease varies considerably. Both direct viral and indirect host-related pathogenic mechanisms have been proposed. The diagnosis depends on neurological and neurodevelopmental assessments. So far, HIV-1-specific antiviral treatment has shown limited effects on neurological manifestations in symptomatic children. Thus, efforts are needed to improve prevention and treatment of CNS involvement. It is still unclear whether early use of antiretroviral agents is of benefit. Conclusion Since experience of treatment of HIV-1 infections in adults cannot easily be translated to children, paediatric clinical trials are needed to answer questions specific to the unique characteristics of children. Received: 10 March 1996ƒAccepted: 10 May 1996     

Effect of some cholinergic drugs on the conditioned pole jump response in rats

Rats were trained to pole jump to a buzzer as the conditioned response. Cholinergic agents, oxotremorine and physostigmine significantly depressed this response. The effect was blocked by atropine. Nicotine and carbachol failed to modify the conditioned pole jump response. It is suggested that the central muscarinic inhibitory receptors are involved in the action of these drugs.     

Managing the sexually transmitted disease pandemic: a time for reevaluation

The serious implications of the sexually transmitted disease (STD) pandemic that currently challenges educators, medical practitioners and governments suggest that prevention strategies, which primarily focus on barrier protection and the management of infection, must be reevaluated and that initiatives focusing on primary prevention of behaviors predisposing individuals to STD risk must be adopted. Human immunodeficiency virus/acquired immunodeficiency syndrome, human papillomavirus, genital herpes, and Chlamydia are used to illustrate the pervasive presence of STDs and their serious consequences for individuals and national infrastructures. Long-term sequelae are discussed, including the emerging link between various sexually transmitted infections and cancer, and the psychosexual and psychosocial factors which impact infected individuals. Although risk reduction and treatment of existing infection is critical, the promotion of optimal life-long health can be achieved most effectively through delayed sexual debut, partner reduction, and the avoidance of risky sexual behaviors.     

Effective binocular integration at the midline requires the corpus callosum

To study the role of the corpus callosum (CC) in midline binocular integration, the effects of late callosotomy and congenital CC agenesis on the ability to perceive dichoptic plaid motion was assessed. Coherent motion was well perceived at all locations in the visual field under dioptic viewing but not along the vertical meridian (VM) when the components were dichoptically presented. This deficit was totally abolished in the agenesis subject and reduced in the callosotomized individual when stimulus size was increased beyond the VM. Electrophysiological correlates were also examined by recording visual evoked potentials and these showed that the P1/N2 components were abnormal for small dichoptic stimuli presented on the midline. These findings attest to the importance of the contribution of CC to midline binocular integration and the effects of cerebral plasticity.     

The misclassification of blinks as saccades: implications for investigations of eye movement dysfunction in schizophrenia

It is important to have a simple. accurate method for recording eye movements. Of the two popular approaches commonly adopted, electro-oculography (EOG) and infrared oculography (IROG), IROG is often accepted as the more accurate, and it is the method that is currently used most frequently to examine eye movements in schizophrenia. This study investigated whether the misclassification of blinks as saccades affects saccade rates when the presence of a blink is determined using only IROG recordings of eye position. Both vertical electro-oculography (VEOG), which can be used to objectively identify blinks, and IROG were recorded while 17 schizophrenia patients and 19 healthy controls were presented with sinusoidal stimuli. Of the blinks identified with the VEOG for the total group of participants, a substantial number (37%) were misclassified as catch-up and anticipatory saccades when only the IROG was used. Furthermore, in the schizophrenia group, but not in the healthy control group, the use of the IROG led to a significant misclassification of blinks as anticipatory saccades. Therefore, when IROG alone is used to identify blinks, the misclassification of blinks as saccades is likely to introduce measurement error into estimates of saccade rates, particularly estimates of anticipatory saccade rates in schizophrenia patients.     

下颌骨自动旋转中心与上颌骨上抬量的相关性研究

目的： 探讨Le Fort I型截骨术上抬上颌骨时下颌骨自动旋转中心的位置,下颌骨自动旋转中心与上颌骨上抬量、下颌骨长度和下颌平面角的关系。方法：选取25例单纯采用Le Fort I型截骨术上抬上颌骨矫治垂直向发育过度的患者,测量其术前、术后头颅定位侧位片。利用Reuleaux法测量实际下颌骨旋转中心。采用SPSS13.0软件包对ANS、PNS上抬量、下颌骨长度、MP-SN角度与下颌骨自动旋转中心进行Pearson相关和线性回归分析。结果：下颌骨自动旋转中心平均位于髁突中点下方15.64 mm,后方0.82 mm处。ANS点和PNS点上抬量、下颌骨长度与下颌骨自动旋转中心位置相关,MP-SN角度与下颌骨旋转中心垂直向位置相关。结论：下颌骨自动旋转中心位于髁突外,其与上颌骨上抬量、下颌骨长度和下颌平面角相关。