Publications by authors named "Tyler K"

Antidepressant effects of acute or chronic nicotine treatments in swim test immobility of Flinders sensitive line (FSL) rats, an animal model of depression, were recently demonstrated (Tizabi et al. Psychopharmacology 142:193, 1999). In the present study we sought to determine whether the antidepressant effects of nicotine could be blocked by the nicotinic antagonist, mecamylamine (MEC).

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Reovirus infection induces apoptosis in cultured cells and in vivo. To identify host cell factors that mediate this response, we investigated whether reovirus infection alters the activation state of the transcription factor nuclear factor kappa B (NF-kappaB). As determined in electrophoretic mobility shift assays, reovirus infection of HeLa cells leads to nuclear translocation of NF-kappaB complexes containing Rel family members p50 and p65.

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Objective: To provide clinicoanatomical correlation for a small pontine tegmental ischemic stroke producing the one and one-half syndrome associated with supranuclear facial weakness.

Design: Case report.

Setting: Tertiary care center.

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Polymerase chain reaction (PCR) is a broadly applied laboratory test for the diagnosis of a wide variety of central nervous system (CNS) diseases, including genetic and autoimmune diseases, malignant neoplasms, and infections. With its ability to detect minute amounts of DNA or RNA contained in tissues or fluids, PCR has improved the rapidity and accuracy of diagnosis, enhanced understanding of pathogenesis, and helped identify infectious causes for diseases previously considered idiopathic. In addition, PCR can be performed on a variety of tissues preserved in different ways--even archival specimens can be used to provide important epidemiological information.

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The goal of this study was to compare the stool-softening effects of olestra and wheat bran and to determine if changes in patterns of propagating colonic motility were associated with the observed stool softening. Mini-pigs were fed chow (control) or chow supplemented with olestra (80 g/day) or wheat bran (80 g/day) for four days. Proximal colonic motility was monitored continuously, stool viscosity and fecal output measured daily, and cecal-to-anal transit time determined.

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We describe a family with two marriages of first cousins and a total of five children with opsismodysplasia. The diagnosis was based on clinical, radiological, and immunhistochemical findings. Helpful to the diagnosis was the testing with type I collagen antibodies, showing abnormally high levels in the hypertrophic area of growth cartilage.

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Introduction of highly active antiretroviral therapy (HAART) has been associated with many changes in the complications of human immunodeficiency virus (HIV) infection. A cohort of 25 HIV patients with progressive multifocal leukoencephalopathy (PML) treated with HAART experienced a median survival of >46 weeks. This is an improvement in prognosis compared with recent historic experience and correlated with HIV RNA viral load reductions.

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Background: Seirogan is a beechwood extract composed of guaiacol, creosol and other related phenolic compounds which is widely used as an anti-diarrhoeal agent in Asia. Abnormalities in water and electrolyte transport are often the cause of diarrhoea, but the mechanism of action of seirogan on small intestinal and colonic mucosal ion transport is unknown.

Aim: To examine the effect of seirogan on electrogenic ion transport in vitro.

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Herpes simplex virus can infect the mammalian brain causing lethal encephalitis (neurovirulence). Previously, herpes simplex virus mutants that are attenuated for neurovirulence have exhibited defects in replication in brain and/or blocks to replication in neuronal cells. We investigated the attenuation of neurovirulence of mutant PAAr5, which exhibits resistance to antiviral drugs due to altered viral DNA polymerase.

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The cellular pathways of apoptosis have not been fully characterized; however, calpain, a cytosolic calcium-activated cysteine protease, has been implicated in several forms of programmed cell death. Reoviruses induce apoptosis both in vitro and in vivo and serve as a model for studying virus-induced cell death. We investigated the potential role of calpain in reovirus-induced apoptosis in vitro by measuring calpain activity as well as evaluating the effects of calpain inhibitors.

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A 23-year-old primigravida with Lemierre's syndrome developed pericardial tamponade secondary to mediastinal infection and anticoagulant therapy. Intrathoracic echocardiographic diagnosis during a period of cardiac arrest led to urgent pericardiocentesis and successful resuscitation.

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Thirty-seven Vibrio cholerae and four non-cholera Vibrio isolates from Ukraine, including strains from the epidemic of 1994-5, were analysed by molecular methods. Results from PFGE and ribotyping indicated that all Ukrainian toxigenic V. cholerae were closely related to each other and to an isolate from a patient from Pakistan.

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Demonstration of the direct involvement of cranial blood vessels by varicella zoster virus (VZV) is facilitated by immunohistochemistry (IHC), in situ hybridization (ISH) and polymerase chain reaction (PCR) techniques. The extent to which an inflammatory vasculitis serves as the pathogenic mechanism for VZV encephalomyelitis (VZVE) is still, however, debated. Most VZVE patients are immunocompromised and show little inflammation, either pre-mortem in cerebrospinal fluid (CSF) or at autopsy.

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Objective: To determine the frequency of mild/atypical herpes simplex virus encephalitis (HSVE) among patients with CSF specimens submitted to a university diagnostic virology laboratory for HSV PCR.

Background: HSVE is the most commonly recognized cause of acute sporadic encephalitis in the United States. Recognized clinical features are based on autopsy- or brain biopsy-confirmed cases.

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This study examines the use of coercive sexual strategies by men and the outcomes of these behaviour for women. Using a sample of 541 college undergraduates, data were gathered from men on their use of three types of coercive sexual strategies and from women on their experiences with these same forms of behaviors. For women, there is a positive association between being sexually active, having sexually permissive attitudes, drinking alcohol and being a victim of certain types of sexual coercive strategies.

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Extrahepatic biliary atresia (EHBA) and choledochal cysts (CDC) are important causes of obstructive jaundice in pediatric patients. Viruses in general, and reoviruses in particular, have long been considered as possible etiologic agents responsible for inciting the inflammatory process that leads to these infantile obstructive cholangiopathies. In an effort to determine whether reovirus infection is associated with these disorders, we used a sensitive and specific reverse-transcriptase polymerase chain reaction (RT-PCR) technique designed to amplify a portion of the reovirus L1 gene segment from extracts of liver and/or biliary tissues.

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In the bloodstream of its mammalian host, the African trypanosome Trypanosoma brucei undergoes a life cycle stage differentiation from a long, slender form to a short, stumpy form. This involves three known major events: exit from a proliferative cell cycle, morphological change and mitochondrial biogenesis. Previously, models have been proposed accounting for these events (Matthews & Gull 1994a).

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In this study, we investigated the relationship between reovirus-induced apoptosis and viral growth. Madin-Darby canine kidney (MDCK) epithelial cells infected with prototype reovirus strains type 1 Lang (T1L) or type 3 Dearing (T3D) were found to undergo apoptosis, and T3D induced apoptosis of MDCK cells to a substantially greater extent than T1L. By using T1L x T3D reassortant viruses, we found that differences in the capacities of these strains to induce apoptosis are determined by the viral S1 and M2 gene segments.

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Reovirus serotype 3 strains infect neurons within specific regions of the neonatal mouse brain and produce a lethal meningoencephalitis. Viral replication and pathology colocalize and have a predilection for the cortex, hippocampus, and thalamus. We have shown previously that infection of cultured fibroblasts and epithelial cells with reovirus type 3 Dearing (T3D) and other type 3 reovirus strains results in apoptotic cell death, suggesting that apoptosis is a mechanism of cell death in vivo.

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