Virus-induced neuronal apoptosis blocked by the herpes simplex virus latency-associated transcript

Latent infections with periodic reactivation are a common outcome after acute infection with many viruses. The latency-associated transcript (LAT) gene is required for wild-type reactivation of herpes simplex virus (HSV). However, the underlying mechanisms remain unclear. In rabbit trigeminal ganglia, extensive apoptosis occurred with LAT(-) virus but not with LAT(+) viruses. In addition, a plasmid expressing LAT blocked apoptosis in cultured cells. Thus, LAT promotes neuronal survival after HSV-1 infection by reducing apoptosis.

Chandra X-Ray Detection of the Radio Hot Spots of 3C 295

An observation of the radio galaxy 3C 295 during the calibration phase of the Chandra X-Ray Observatory reveals X-ray emission from the core of the galaxy, from each of the two prominent radio hot spots, and from the previously known cluster gas. We discuss the possible emission processes for the hot spots and argue that a synchrotron self-Compton (SSC) model is preferred for most or all of the observed X-ray emission. SSC models with near-equipartition fields thus explain the X-ray emission from the hot spots in the two highest surface brightness FR II radio galaxies, Cygnus A and 3C 295. This lends weight to the assumption of equipartition and suggests that relativistic protons do not dominate the particle energy density.

Inhibition of L-homocysteic acid and buthionine sulphoximine-mediated neurotoxicity in rat embryonic neuronal cultures with alpha-lipoic acid enantiomers

In the present report, we have set out to investigate the potential capacity of both the oxidised and reduced forms of RS-alpha-lipoic acid, and its separate R-(+) and S-(-)enantiomers, to prevent cell death induced with L-homocysteic acid (L-HCA) and buthionine sulphoximine (BSO) in rat primary cortical and hippocampal neurons. L-HCA induced a concentration-dependent neurotoxic effect, estimated by cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) reduction, in primary neurons, but was significantly more toxic for hippocampal (EC(50)=197 microM) compared with cortical neurons (EC(50)=1016 microM) whereas D-HCA demonstrated only moderate (<20%) toxicity. On the other hand, cortical and hippocampal cultures were equally susceptible (341 and 326 microM, respectively) to the neurotoxic action of BSO. Antioxidants including butylated hydroxyanisole, propyl gallate and vitamin E protected cells against the neurotoxic effect of L-HCA and BSO. However, N-acetyl-cysteine and tert-butylphenyl nitrone, although capable of abrogating L-HCA-mediated cell death showed no protective effect against BSO-mediated toxicity. RS-alpha-lipoic acid, RS-alpha-dihydrolipoic acid and the enantiomers R-alpha-lipoic acid and S-alpha-lipoic acid protected cells against L-HCA-mediated toxicity with EC(50) values between 3.1-8.3 microM in primary hippocampal neurons and 2.6-16.8 microM for cortical neurons. However, RS-alpha-lipoic acid, RS-alpha-dihydrolipoic acid, and S-alpha-lipoic acid failed to protect cells against the degeneration induced by prolonged exposure to BSO, whereas the natural form, R-alpha-lipoic, was partially active under the same conditions. The present results indicate a unique sensitivity of hippocampal neurons to the effect of L-HCA-mediated toxicity, and suggest that RS-alpha-lipoic acid, and in particular the R-alpha-enantiomeric form is capable of preventing oxidative stress-mediated neuronal cell death in primary cell culture.

SH2-Containing protein tyrosine phosphatase-1 (SHP-1) association with Jak2 in UT-7/Epo cells

We have investigated the interaction of the SH2-containing protein tyrosine phosphatase-1 (SHP-1) and Jak2 in an erythropoietin (Epo)-dependent human leukemia cell line, UT-7/Epo, using reciprocal immunoprecipitation and immunoblotting. The Epo-induced kinetics and dose response on phosphorylated Jak2 in anti-SHP-1 precipitates of UT-7/Epo cell lysates were similar to those in direct anti-Jak2 precipitates, suggesting that Jak2 coprecipitated with SHP-1. Furthermore, immunoblotting with anti-Jak2 and anti-SHP-1 antibodies indicated that SHP-1 appeared to be constitutively associated with non-tyrosine-phosphorylated Jak2 in UT-7/Epo cells in the absence of Epo and without phosphorylation of the Epo receptor (EpoR). Competition studies with C-terminal SHP-1 and Jak2 peptides decreased the amounts of SHP-1 and Jak2 detected in immunoprecipitates supporting the specific coprecipitation of SHP-1 and Jak2. In the presence of a recombinant GST-fusion protein containing both the N-terminal and C-terminal SH2 domains of SHP-1, anti-GST precipitated the fusion protein but not cellular Jak2. These studies suggest that SHP-1 and Jak2 are constitutively associated in UT-7/EPO cells. The association is not dependent upon Epo and is not mediated via SHP-1 SH2 binding. Sequential double immunoprecipitation demonstrated that only a small portion of intracellular Jak2 and SHP-1 molecules are constitutively associated. This partial association pattern may allow a more flexible and diverse regulation of Jak2 and SHP-1 activities. Whether Jak2 and SHP-1 are directly associated with each other or are part of a larger complex needs further investigation.

Spontaneously relapsing clonal, mucosal cytotoxic T-cell lymphoproliferative disorder: case report and review of the literature

Primary T-cell lymphoma of the gastrointestinal tract is a rare and usually aggressive disorder that may be associated with celiac disease. The authors describe a unique case of a clonal proliferation of CD8+ T cells involving the oral mucosa, ileum, and colon of a 35-year-old man that has regressed spontaneously and recurred numerous times over a 9-year period without treatment. The patient's symptoms were limited to occasional rectal bleeding and recurring painful oral ulcers. Within the intestine, these collections of small T cells induced minimal architectural distortions and did not show extensive epitheliotrophism. Polymerase chain reaction and sequencing analyses revealed that the identical T-cell clone has been present for more than 9 years and in different mucosal locations in this patient. This may represent a unique T-cell lymphoproliferative process akin to a mucosal counterpart of lymphomatoid papulosis of the skin.

Instrumentally detected changes in motor functioning in patients with low levels of antipsychotic dopamine D2 blockade

Extrapyramidal side-effects (EPSE) of antipsychotic medication are related to the occupancy of dopamine D2 receptors and there appears to be a threshold of D2 occupancy below which clinically EPSE are unlikely to occur. It is unclear whether there are motor changes produced by 'subthreshold' levels of D2 occupancy that are not detectable by clinical examination. This study was designed to investigate whether a number of electromechanical instrumental techniques could detect 'subthreshold' motor changes and whether these changes correlate with dopamine D2 occupancy as measured by [11C]-raclopride PET scan. Twenty medication naïve patients were studied before and during treatment with low dose haloperidol. Instrumental techniques detected an asymmetrical worsening in motor function with drug treatment despite the failure of the group to experience significant EPSE. These changes did not correlate with D2 occupancy and measurements of rigidity, tremor, and bradykinesia did not closely inter-correlate.

Hepatorenal problems presented in an urban high dependancy unit in a user of ecstasy and cocaine

A case is presented of a young man aged 25 years who had an episode of jaundice and renal failure after using a small amount of ecstasy and cocaine. There is a discussion of the issues raised by the case as well as some points of interest for research and health education.

Unusual association of hypertrophic cardiomyopathy with complete atrioventricular canal defect and Down syndrome

Hypertrophic cardiomyopathy typically presents as an isolated cardiac lesion. Transient hypertrophic cardiomyopathy in infancy has been described as a result of exposure to maternal metabolic disorders or to corticosteroids. In addition, hypertrophic cardiomyopathy has been described in association with genetic syndromes and, in rare cases, as a primary lesion associated with other congenital heart defects. We describe the unusual association of hypertrophic cardiomyopathy and complete atrioventricular canal defect in an infant with trisomy 21.

Genetic alterations in 'normal' luminal and myoepithelial cells of the breast

Chromosomal loci exhibiting loss of heterozygosity (LOH) at high frequency in invasive breast cancer have been investigated in 'normal' breast tissue from patients with carcinoma and from reduction mammoplasty specimens. Duct-lobular units dissected from paraffin-embedded tissues and 485 'normal' luminal and myoepithelial cell clones were studied. Overall, LOH was found in normal cells in 5/10 breast cancer cases and 1/3 reduction mammoplasty specimens. LOH was identified in normal cells adjacent to and distant from the tumour. In one case, all luminal and myoepithelial samples exhibited loss of the same allele on chromosome 13q. One case in which the patient had a germline truncating mutation in the BRCA1 gene exhibited LOH on 17q in 3/33 normal clones. One of these clones showed loss of wild-type allele indicating gene inactivation. This sample also had LOH at markers on chromosomes 11p and 13q. One of 93 clones from three reduction mammoplasties showed allele loss at a locus on chromosome 13q. The identification of LOH in breast lobules suggests that they may be clonal. The demonstration of genetic alteration in luminal and myoepithelial cells provides evidence for the presence of a common stem cell for the two epithelial cell types. LOH has been demonstrated in normal tissues near and away from the carcinoma, suggesting that genetic alterations are likely to be more heterogeneous and widespread than is currently envisaged, and probably occur very early in breast development. Homozygous deletion of BRCA1 per se does not appear to provide clonal advantage.

Retinoic acid and CO2 laser resurfacing

The purpose of this study was to analyze the effect of retinoic acid on wound healing and depth of injury in an animal skin model resurfaced with a CO2 laser. The dorsal skin of 21 Hartley guinea pigs was divided into halves. One-half received a daily application of 0.05% retinoic acid for 28 days, whereas the other half served as the control. The animals were divided into three treatment groups of seven animals. Group A was laser resurfaced with one pass of the Coherent UltraPulse CO2 laser (300 mJ, 60 W, density 40 percent). Group B received two passes, and group C received three passes. Histologic studies were obtained before laser resurfacing and days 1, 4, and 7 after resurfacing. Depth of injury, thickness, number of squamous cell and granular cell layers, and epithelialization rates were measured. We found that the depth of injury was statistically less in animals pretreated with retinoic acid. Granular cells were thicker and more numerous at day 4 in pretreated animals but similar to controls by day 7. Animals pre-treated with retinoic acid overall seemed to heal wounds earlier. In conclusion, pretreatment with retinoic acid may reduce the depth of injury in laser resurfacing and speed healing rates.

The latency-related gene of bovine herpesvirus 1 inhibits programmed cell death

Although viral gene expression occurs in the peripheral nervous system during acute infection, bovine herpesvirus 1 (BHV-1) gene expression is extinguished, many neurons survive, and latency ensues. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA, which is alternatively spliced in trigeminal ganglia during acute infection (L. Devireddy and C. Jones, J. Virol. 72:7294-7301, 1998). A subset of neurons express a protein encoded by the LR gene and the LR protein (LRP) is associated with cyclin-dependent kinase 2 (Cdk2)/cyclin complexes during productive infection (Y. Jiang, A. Hossain, M. T. Winkler, T. Holt, A. Doster, and C. Jones, J. Virol. 72:8133-8142, 1998). LR gene products inhibit cell cycle progression, perhaps as a result of LRP interacting with Cdk2/cyclin complexes. During acute infection, expression of cyclin A occurs in trigeminal ganglionic neurons (L. M. Schang, A. Hossain, and C. Jones, J. Virol. 70:3807-3814, 1996). Inappropriate expression of G(1)- and S-phase cyclins can initiate programmed cell death (PCD), apoptosis, in neurons, suggesting that LR gene products inhibit PCD. To test this hypothesis, we modified an assay to measure PCD frequency in transiently transfected cells. C(6)-ceramide, fumonisin B(1) (FB(1)), or etoposide was used to initiate PCD following transfection of cells with plasmids expressing LR gene products and the beta-galactosidase gene. Transfected cells that survived were quantified by counting beta-galactosidase-positive cells. Plasmids that expressed LR gene products promoted survival of monkey kidney (CV-1), human lung (IMR-90), or mouse neuroblastoma (neuro-2A) cells after induction of PCD. Plasmids with termination codons at the beginning of LR open reading frames or deletion of sequences that mediate splicing of LR RNA did not promote cell survival following PCD induction. We hypothesize that LR gene products play a role in promoting survival of postmitotic neurons during acute infection or reactivation.

New methods for the characterisation of biopharmaceuticals: conjugate vaccines against Haemophilus influenzae type b

Modern physicochemical methods allow biological pharmaceuticals, particularly those arising from recombinant DNA technology, to be characterised with a degree of precision not previously possible. These techniques, which tell us what a material is (rather than what it does) provide an approach complementary to traditional bioassays for the control of biological pharmaceuticals. As we come to understand the mechanisms by which structural variation modulates the various biological activities of a product, structure-based assays will be able to replace biological identity and potency assays, although replacement of safety tests to find trace impurities (such as endotoxin) may be more difficult.

Ocular findings in HIV-1 positive and HIV-1 negative participants in a rural population-based cohort in Uganda

PURPOSE

To report the ocular findings in HIV-1 seropositive individuals and HIV-negative controls in a population-based cohort in rural Uganda.

METHODS

Participants were examined by an ophthalmologist, who was unaware of their HIV-status.

RESULTS

238 participants were examined, 43 were HIV-1 prevalent cases (infected prior to 1990); 62 were HIV-1 incident cases and 133 were HIV-negative controls. Eleven of the HIV-positive participants had AIDS, and a further 8 had a CD4 count of less than 200 cells/mm3. Bilateral low vision was recorded in 9 participants and cataracts were the main cause of bilateral low vision. The mean intra-ocular pressure (IOP) was 12.6 mm Hg, and no association was found between IOP and CD4 lymphocyte count. Although significantly more HIV positives had some sign of intraocular inflammation compared to the negatives (p = 0.02) there was no significant linear trend in the HIV positives with decreasing CD4 count. Overall, 11 (26%) prevalent, 6 (10%) incident cases and 8 (6%) HIV-negatives controls had some evidence of intraocular inflammation, however, only one person had reduced visual acuity attributable to these lesions. Punctate epithelial erosions and keratic precipitates in the anterior chamber were seen significantly more frequently in HIV-positives compared to the HIV-negative controls. Cotton wool spots were not seen.

CONCLUSIONS

A substantial proportion of HIV-infected persons had ocular findings which may have been attributable to their infection, however in only one case did this result in reduced visual acuity. Although the ocular complications of AIDS seem to comprise a large extra element in the work load of tertiary care hospitals dealing with eye problems, on a population basis such cases are infrequent.

Contribution of bradykinin B(1) and B(2) receptors in allergen-induced bronchial hyperresponsiveness

Bradykinin (BK) is a peptide mediator generated at sites of inflammation and its effects are mediated through constitutively expressed B(2) receptor or through induction of B(1) receptors. We examined the role of these receptors in bronchial hyperresponsiveness (BHR). Brown-Norway rats sensitized with ovalbumin (OA) and Al(OH)(3) intraperitoneally, were exposed 3 wk later to either saline or OA aerosol. B(1) receptor antagonist desArg(10)[Hoe140] (200 nmol/kg or 1 micromol/kg, intraperitoneally) or B(2) receptor antagonist Hoe140 (200 nmol/kg, intraperitoneally) was administered 30 min before allergen exposure. Hoe140 had no effect on OA-induced BHR to acetylcholine (ACh) and bronchoalveolar lavage fluid (BALF) cellular profiles, but inhibited bronchoconstriction to BK (p < 0.04). At both doses, desArg(10)[Hoe140] dose-dependently inhibited allergen-induced BHR to ACh (p < 0.01), but had no effect on bronchoconstriction to BK or baseline ACh responsiveness. The inflammatory cells in BALF were not affected apart from reduced lymphocyte numbers at the highest dose. B(1) receptor mRNA expression measured by Northern analysis was increased after allergen exposure in sensitized lungs, with a peak at 2 to 6 h after exposure, whereas B(2) receptor mRNA expression remained unchanged. Newly induced BK B(1) receptors may be involved in allergen-induced BHR to ACh, whereas constitutive B(2) receptors mediate BK-induced bronchoconstriction.

Hemodynamic abnormalities in fetuses with congenital heart disease

The purpose of this investigation was to assess left and right ventricular function, volume ejection fraction, combined stroke volume, and combined ventricular output in the human fetus with congenital heart disease compared to the normal healthy fetus. Seventy-two fetuses with a variety of in utero diagnosed congenital cardiac defects were compared with a control group of fetuses with structurally normal hearts matched for race, maternal age, and gestational age. We demonstrated significant hemodynamic changes in the fetus with congenital heart disease. There was a significant (p < 0.0001) decrease in the volume ejection fractions, biventricular stroke volume, and cardiac output in the congenital heart disease group compared to matched controls. Our findings suggest that hemodynamic abnormalities in the fetus with congenital heart disease are present before birth and we speculate that myocardial reserve may not be adequate to respond to hemodynamic stressors such as birth or heart surgery.

Real-time t(11;14) and t(14;18) PCR assays provide sensitive and quantitative assessments of minimal residual disease (MRD)

Non-Hodgkin's lymphoma (NHL) arises as a clonal transformation of normal B and T cell differentiation and is often characterized by a higher incidence of specific chromosomal translocations. We have developed real-time TaqMan PCR assays directed toward two of these tumor-associated DNA markers, the t(14;18)(q32;q21.3) at the major breakpoint region of the bcl-2 gene and the t(11;14)(q13;q32) at the bcl-1 major translocation cluster. During analysis of serial dilutions of t(14;18)-positive DNA, the t(14;18) real-time PCR was at least as sensitive as nested PCR and demonstrated enhanced quantitative potential. Moreover, in a blinded comparison of the t(14;18) real-time PCR and a clinically validated nested PCR protocol using 134 cell line and patient DNA samples, the real-time PCR detected the translocation in 30.0% more cases than nested PCR. Both the t(14;18) and t(11;14) real-time PCR assays were used to quantitate minimal residual disease (MRD) in an NHL clinical trial assessing the safety and efficacy of a tumor-purging protocol in autologous stem cell transplantation. The assays were also used to evaluate disease depletion in an ex vivo tumor spiking model in which normal peripheral blood was spiked with tumor cell lines and processed according to the clinical purging method. PCR data from both the clinical trial and the ex vivo model demonstrated a 4 to 6 log reduction in tumor cells during CD34+ and CD34+ Thy-1+ enrichment. Because the t(14;18) and t(11;14) real-time PCR assays are very sensitive, quantitative, rapid, and require no post-PCR manipulation, they may serve as practical alternatives to nested PCR.

Bovine herpesvirus 1 can infect CD4(+) T lymphocytes and induce programmed cell death during acute infection of cattle

Acute infection of cattle with bovine herpesvirus 1 (BHV-1) represses cell-mediated immunity, which can lead to secondary bacterial infections. Since BHV-1 can induce apoptosis of cultured lymphocytes, we hypothesized that these virus-host interactions occur in cattle. To test this hypothesis, we analyzed lymph nodes and peripheral blood mononuclear cells (PBMC) after calves were infected with BHV-1. In situ terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling (TUNEL) staining of lymphoid tissues (pharyngeal tonsil, cervical, retropharyngeal, and inguinal) was used to detect apoptotic cells. Calves infected with BHV-1 for 7 days revealed increased apoptotic cells near the corticomedullary junction in lymphoid follicles and in the subcapsular region. Increased frequency of apoptotic cells was also observed in the mucosa-associated lymphoid tissue lining the trachea and turbinate. Immunohistochemistry of consecutive sections from pharyngeal tonsil revealed that CD2(+) T lymphocytes were positive for the BHV-1 envelope glycoprotein gD. The location of these CD2(+) T lymphocytes in the germinal center suggested that they were CD4(+) T cells. Electron microscopy and TUNEL also revealed apoptotic and herpesvirus-infected lymphocytes from this area. Fluorescence-activated cell sorting analyses demonstrated that CD4(+) and CD8(+) T cells decreased in lymph nodes and PBMC after infection. The decrease in CD4(+) T cells correlated with an increase in apoptosis. CD4(+) but not CD8(+) lymphocytes were infected by BHV-1 as judged by in situ hybridization and PCR, respectively. Immediate-early (bovine ICP0) and early (ribonucleotide reductase) transcripts were detected in PBMC and CD4(+) lymphocytes prepared from infected calves. In contrast, a late transcript (glycoprotein C) was not consistently detected suggesting productive infection was not efficient. Taken together, these results indicate that BHV-1 can infect CD4(+) T cells in cattle, leading to apoptosis and suppression of cell-mediated immunity.

A case of Capgras delusion following critical illness

Hallucinations and paranoid delusions are recognised complications of critical illness. However, the occurrence of Capgras syndrome, in response to critical illness, where patients are convinced that doubles have replaced close family has not been described in the literature. There have been isolated case histories in the literature in response to medical procedures or illness but mostly in patients suffering from schizophrenia. A 42 year old woman was admitted to the intensive care unit (ICU) with pneumonia, following extensive surgery for a squamous cell carcinoma, secondary to Crohns disease. She had no history of previous head injury, cerebro-vascular problems or psychiatric disorder. She reported having memories of all her family, with the exception of her mother, being replaced by aliens while she was on the ICU. The delusion was only diagnosed once it had resolved and the patient was able to talk, and this highlights the difficulty of diagnosing delusions while patients are still intubated and unable to verbalise their concerns. It has been suggested that a defect in the ability to recognise the emotional significance of the face lies at the root of Capgras syndrome.

Reduction of severe aggressive behaviour in acquired brain injury: case studies illustrating clinical use of the OAS-MNR in the management of challenging behaviours

Challenging behaviour, especially when this takes the form of aggression, may impede or prevent progress in neurorehabilitation. Despite its prevalence, the literature on management of aggression after brain injury is not extensive. It has been suggested that the 'Overt Aggression Scale-Modified for Neurorehabilitation' (OAS-MNR) could be used to help standardize future studies of aggressive behaviour. It was also suggested that this scale has sufficient properties to be useful in clinical work. In this paper, three case studies are described which attempt to illustrate the potential value of the OAS-MNR in neurorehabilitation. The use of the scale also provides evidence relating to the continued efficacy of the neurobehavioural model. In the first study, two cases are described in which reduction in aggression occurred through participation in individualized, needs-led holistic treatment programmes, which incorporated multiple interventions. These were based on neurobehavioural principles. In the second study, a further single case was presented which illustrated how the scale may be used to generate hypotheses regarding aggressive behaviour and to drive treatment. Causation and maintenance of aggression are discussed, especially with regard to cognitive impairment. Finally, practical points relating to the use of the OAS-MNR in clinical practice are reviewed.