Apoptosis induced by HIV-1 infection of the central nervous system

Apoptosis plays a role in AIDS pathogenesis in the immune system, but its role in HIV-1-induced neurological disease is unknown. In this study, we examine apoptosis induced by HIV-1 infection of the central nervous system (CNS) in an in vitro model and in brain tissue from AIDS patients. HIV-1 infection of primary brain cultures induced apoptosis in neurons and astrocytes in vitro as determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and propidium iodide staining and by electron microscopy. Apoptosis was not significantly induced until 1-2 wk after the time of peak virus production, suggesting induction by soluble factors rather than by direct viral infection. Apoptosis of neurons and astrocytes was also detected in brain tissue from 10/11 AIDS patients, including 5/5 patients with HIV-1 dementia and 4/5 nondemented patients. In addition, endothelial cell apoptosis was frequently detected in the brain of AIDS patients and was confirmed by electron microscopy. Most of the apoptotic cells were not localized adjacent to HIV-1-infected cells, providing further evidence for induction by soluble factors. In six non-AIDS control patients with normal brain, apoptotic cells were absent or limited to rare astrocytes. However, TUNEL-positive neurons and astrocytes were frequently detected in seven patients with Alzheimer's disease or abundant senile plaques. These studies suggest that apoptosis is a mechanism of CNS injury in AIDS which is likely to be induced by soluble factors. The apoptosis of endothelial cells in the CNS raises the possibility that some of these factors may be blood-derived.

Effect of migration and related environmental changes on serum lipid levels in southwestern Chinese men

To determine migration-related differences in serum lipid levels and to estimate the contribution of environmental factors to these differences, the authors conducted a cross-sectional study among 1,222 residents of southwestern China in 1988 and 1989: 521 Yi farmers living in a remote rural area, 340 Yi migrants to an urban setting, and 361 Han people living in the same urban setting. Serum total and high density lipoprotein cholesterol and serum triglyceride were measured after a 14-hour fast. Information on age, cigarette smoking, alcohol consumption, and physical activity was obtained by questionnaire. Diet was assessed by use of three 24-hour diet recalls. The Yi farmers had the lowest age-adjusted serum lipid levels among the three groups, white the Yi migrants and their Han counterparts had similar lipid levels. After adjustment for age, body mass index, cigarette smoking, alcohol drinking, and dietary nutrient intake, the difference in serum lipid profile between the Yi migrants and the Yi farmers was substantially reduced. These results indicate that rural-urban migration is associated with higher serum lipid levels. This migration-related difference in serum lipids can be partially explained by changes in lifestyle and dietary nutrient intake. The authors conclude that environmental factors are important determinants of population serum lipid levels in southwestern Chinese.

The role of blood pressure as a risk factor for renal disease: a review of the epidemiologic evidence

The aim of the paper is to examine the relationship between blood pressure (BP) and renal disease with an overview of observational and experimental investigations, with the emphasis on studies that provide data obtained in unselected population samples. We have found an increasing body of evidence from cross-sectional, case-control, prospective, and experimental studies that indicate BP is an important, independent predictor of both increased relative and attributable risk of renal insufficiency and end-stage renal disease. The relationship between BP and subsequent renal disease appears to be positive and continuous throughout the entire range of BP. Furthermore, the data indicate that elevations in systolic BP (SBP) are stronger predictors of risk compared to corresponding increases in diastolic BP (DBP). Clinical trials experience suggests that reduction in BP decreases the risk of subsequent renal disease. Ongoing trials should help to clarify issues related to choice of antihypertensive therapy and optimal goals for reduction of BP in order to prevent renal disease.

Altered expression of bcl-2 and bax mRNA in amyotrophic lateral sclerosis spinal cord motor neurons

One of the primary neurodegenerative events occurring in amyotrophic lateral sclerosis (ALS) is the selective loss of spinal cord alpha motor neurons. To study the potential role of apoptosis in the degeneration of these motor neurons, in situ hybridization was used to measure the expression of two apoptotic cell death genes, bcl-2 and bax, in control and ALS lumbar spinal cord sections. The strongest hybridization signal for bcl-2 mRNA in neurological and nonneurological control spinal cords was found primarily in lamina IX alpha motor neurons, while a weaker hybridization signal was found in neurons of Clarke's nucleus and the proper sensory nucleus of the dorsal horn. Surviving lamina IX motor neurons in ALS spinal cord sections also expressed bcl-2 mRNA, but at levels that were significantly and selectively decreased (4.7-fold) compared with controls. bax mRNA hybridization signal was detected in several cells throughout the gray matter in control and ALS lumbar spinal cord, but was significantly and selectively increased (2.8-fold) in ALS motor neurons. Given the proposed interactive roles of these genes in apoptosis, the present findings favor a scenario in which this mode of cell death would contribute to spinal cord motor neuron degeneration in ALS.

[Determination of copper and cadmium in water by continuous flow analysis]

A continuous flow analysis system for the preconcentration of Cu2+ and/or Cd2+ in water was developed. Trace copper or cadmium in water could be concentrated on activated carbon particles packed in micro column at pH > or = 9.0. The adsorbed analyte was eluted with 0.5 ml 2.5% nitric acid and determined by flame atomic absorption spectrometry. A sample size of 10-25 ml sufficed for the determination of copper2+ or cadmium at a level as low as microgram/L. The relative standard deviation of 6 parallel determinations was 4.3% for copper and 11% for cadmium. The proposed method was applied to the determination of copper and cadmium in natural water with a recovery of 84.4%-118%.

Fas ligand mutation in a patient with systemic lupus erythematosus and lymphoproliferative disease

The pathogenesis of systemic lupus erythematosus (SLE) is multifactorial and multigenetic. The apoptosis genes, fas and fas ligand (fasL), are candidate contributory genes in human SLE, as mutations of these genes result in autoimmunity in several murine models of this disease. In humans, fas mutations result in a familial autoimmune lymphoproliferative syndrome, but defects in FasL have not yet been identified. In this study, DNA from 75 patients with SLE was screened by single-stranded conformational polymorphism analysis for potential mutations of the extracellular domain of FasL. A heterozygous single-stranded conformational polymorphism for FasL, was identified in one SLE patient, who exhibited lymphadenopathy. Molecular cloning and sequencing indicated that the genomic DNA of this patient contained an 84-bp deletion within exon 4 of the fasL gene, resulting in a predicted 28 amino acid in-frame deletion. Analysis of PBMC from this patient revealed decreased FasL activity, decreased activation-induced cell death, and increased T cell proliferation after activation. This is the first report of defective FasL-mediated apoptosis related to a mutation of the human Fasl, gene in a patient with SLE and suggests that fasL mutations are an uncommon cause of the disease.

[Nested polymerase chain reaction (PCR) and multiple cloned antibody capture PCR for the examination of serum hepatitis B virus DNA in negative hepatitis B surface antigen patients suffering from liver diseases]

In order to find out rapidly the causes of the liver diseases suffered by patients with negative hepatitis B surface antigen (HBsAg), nested polymerase chain reaction (PCR) and multiple cloned antibody capture PCR techniques were established to examine serum hepatitis B virus (HBV) DNA. By using both techniques along with the examination of hepatitis C virus (HCV) infection, the causes of chronic liver diseases with negative HBsAg were studied. It is found that nested-PCR can increase the sensitivity of single PCR more than 1,000 fold and multiple cloned antibody capture-PCR can detect concentration of HBV DNA as low as 0.1-0.01 pg/L. HBV DNA positive patients were found in 45.5%, 30.8%, 13.3% and 100% respectively of the patients suffering from liver cirhosis with negative HBsAg (group A, 22 cases), chronic hepatitis with negative HBsAg (group B, 13 cases), normal subjects with negative HBsAg and positive hepatitis B core antibody (HBcAb, group C, 30 cases) and liver cirhosis with positive HBsAg and negative HBeAg (group D, 12 cases). HBV DNA can be also found in the serum of HBsAb positive patients and subjects supposed to be healthy, 81.8% and 53.8% of the patients were infected with HBV and/or HCV in group A and group B respectively. All these results suggest that nested-PCR and multiple cloned antibody capture-PCR are rapid and highly sensitive methods for detection of serum HBV DNA. HBV infection is an important cause of chronic liver diseases in patients with negative HBsAg. The causes of most of the HBsAg-negative chronic liver diseases are related with infection of viruses. The clinical significance of serum HBsAb in naturally infected patients should be reconsidered.

Long-term oral administration of L-arginine enhances endothelium-dependent vasorelaxation and inhibits neointimal thickening after endothelial denudation in rats

OBJECTIVE

To further prove the hypothesis that local decrease of nitric oxide (NO) synthesis and/or its activity might be critically important in the disturbance of vascular homeostasis after vascular injuries.

METHODS

Intimal thickening model induced by air-drying denudation of rat right common carotid artery was performed to evaluate the effects of long-term oral administration of L-arginine on neointimal thickening and acetylcholine-induced endothelium-dependent vasorelaxation (EDR) by histomorphometric and functional studies.

RESULTS

Reductions in EDR function persisted and simultaneously developed prominent neointimal thickening by 14 days after denudation. Long-term oral supplementation of L-arginine (1 g/kg/day) significantly enhanced EDR from 43.5% +/- 12.35% to 68.8% +/- 9.0% (n = 10, P < 0.001) and reduced neointimal thickening from 62.45 microns +/- 11.26 microns to 21.45 microns +/- 6.34 microns (n = 10, P < 0.001) as compared with each control animals.

CONCLUSIONS

This study shows that oral administration of L-arginine significantly inhibits neointimal thickening and preserves NO-mediated EDR in experimental endothelial denudation, suggesting an important role for L-arginine, NO pathway in the regulation of vascular homeostasis after endothelial injury which might be salutary in prevention restenosis after coronary angioplasty.

Comparative Studies on the Diagnosis of Hepatitis E Virus Antibodies with ORF-2 and ORF-3 Proteins Expressed in Insect Cells

Hepatitis E is a worldwide health problem, especially in developing countries. The virus genome contains three different open reading frames (ORFs): ORF-1, which is believed to encode nonstructural proteins, and ORF-2 and ORF-3, which are believed to encode structural proteins. Presently, serologic tests for the detection of human antibodies to hepatitis E virus (HEV) infection are primarily based on the ORF-2 structural protein expressed in Escherichia coli, insect cells or synthetic peptides. We report here the comparative studies on the diagnosis of HEV infection with full-length ORF-2 and ORF-3 proteins expressed in insect cells. We found that 31 of 74 (42%) sera were positive for IgM antibody to HEV (anti-HEV) using the ORF-2 protein as an antigen, as compared to 6 of 74 sera (8%) using the ORF-3 protein as an antigen (p < 0.001). Similarly, 49 of 74 sera (66% were positive for IgG anti-HEV utilizing the ORF-2 protein versus 12 of 74 sera (16%) when the ORF-3 protein was used (p < 0.001). These results suggest that the recombinant ORF-2 protein is more sensitive as a diagnostic antigen for detecting antibodies to HEV in both acute-phase and convalescent-phase sera than ORF-3 protein. Copyright 1996 S. Karger AG, Basel

Quantitative assessment of stenotic aortic valve area by using intracardiac echocardiography: in vitro validation and initial in vivo illustration

Quantitative assessment of aortic stenosis (AS) is subject to the limitations of all current noninvasive and invasive methods. The ability to obtain a direct measure of aortic valve area with high resolution by intracardiac echocardiography (ICE) could be of great benefit to catheterized patients. To provide a fixed AS area as an ideal standard for comparison, we performed ICE in 12 sheep hearts with experimentally created AS and five human AS hearts from autopsies. ICE catheters were passed retrograde across the aortic valve, and the minimal orifice area on pullback was planimetered and compared with calibrated video imaging. The entire orifice circumference could be successfully recorded in 16 (94%) hearts. Orifice area from ICE correlated well with actual values (r=0.98; standard error of the estimate [SEE] = 0.06 cm2). To illustrate the applicability in vivo, two canine models and 10 patients with AS were studied. The limiting orifice could be imaged in both animals and in 8 of 10 patients, in whom values agreed well with invasive data (r= 0.95; SEE = 0.04 cm2). ICE can therefore accurately measure AS orifice area in vitro; it can be applied in vivo as well. These validation studies laid the foundation for subsequent clinical studies and applications.

Common alternative gene alterations in adult malignant astrocytomas, but not in childhood primitive neuroectodermal tumors: P 16ink4 homozygous deletions and CDK4 gene amplifications

Alterations in P16ink4 or in the gene encoding one of its ligands, cyclin-dependent kinase 4 (CDK4), have been reported in human glioma cell lines and primary tumors but not in primitive neuroectodermal tumors (PNETs), the most common malignant brain tumor of childhood. In this study the authors have examined DNA from 20 primary PNETs in children and from 20 malignant astrocytomas to assess the frequency of P16ink4 and CDK4 gene alterations associated with each type of tumor. Southern hybridization analysis revealed homozygous P16ink4 deletions in one (5%) of 20 PNETs and in seven (35%) of 20 malignant astrocytomas. The CDK4 gene amplification was evident in two additional astrocytomas, but not in any of the PNETs. In total, nine astrocytomas (45%) exhibited homozygous P16ink4 deletion or CDK4 gene amplification, but only one PNET (5%) demonstrated either gene alteration. These results indicate that the incidence of P16ink4 and CDK4 gene alterations in these two groups of tumors is different and suggest distinct pathogenetic etiologies may be associated with each neoplasm.

A waterborne outbreak of hepatitis E virus transmission in southwestern Vietnam

A hepatitis outbreak affecting primarily adults occurred in southwestern Vietnam, along the Hau river bordering Cambodia, in June and July 1994. One month after the outbreak, sera and epidemiologic information were collected from 150 subjects: 50 patient cases, 50 matched, healthy community controls, and 50 geographic controls living 50 km upriver. The prevalence of immunoglobulin G (IgG) to hepatitis E virus (HEV) was significantly (P < 0.001) higher (76%) among cases than among the matched (38%) and geographic (38%) control populations. Immunoglobulin M to HEV was detected by enzyme-linked immunosorbent assay and Western blot in 16% of sera collected from patients one month after the outbreak. Hepatitis E virus RNA was detected with the polymerase chain reaction in 6% of sera from patients; RNA was not detected in either control group. These results indicate that HEV was the etiologic agent responsible for the outbreak. Children were under-represented among clinical cases. River water served as the principal source for drinking and bathing among most (96%) of the case and control study populations. Boiling of drinking water was negatively associated (P < 0.05) with IgG anti-HEV seropositivity. Unusually heavy rainfall likely contributed to conditions that favored the outbreak. This is the first recognized outbreak of epidemic HEV transmission in Indo-China.

Influence of dynamic contact of hard contact lens materials on corneal epithelial cells examined by rose bengal staining

PURPOSE

To establish a method for evaluation of less irritating contact lens materials by dynamic contact with cornea, we examined epithelial and endothelial cell injury to the porcine cornea caused by rotatory rubbing with four kinds of hard contact lenses (HCL).

METHODS

The HCLs used were (1) polymethylmethacrylate (PMMA) HCL, (2) gas-permeable HCL composed of a graft co-polymer of dextran derivative and methylmethacrylate (MMA) (Suncon Mild II(TM), 12 Dk), (3) gas-permeable HCL composed of a graft co-polymer of dextran derivative, a monomer containing silicone, a monomer containing fluorine and MMA (New Dx HCL-136, 32 Dk), and (4) gas-permeable HCL composed of a monomer containing silicone, a monomer containing fluorine and MMA(RGPL-A, 216 Dk). Using a specially designed apparatus, we produced a standardized injury to the epithelium or endothelium of porcine corneas by holding the HCL against the corneal surface while rotating the lens rapidly.

RESULTS

After rotatory rubbing of the HCL on the epithelium, the degree of rose bengal staining of the epithelial cells, indicating degeneration of the cells and mucin detachment, were significantly different among these HCLs (New Dx HCL-136 < Suncon Mild II(TM), PPMA < RGPL-A), and the cell injury rates of the endothelium were also significantly different among them (Suncon Mild II(TM) < New Dx HCL-136, PMMA < RGPL-A). The water-wettability of HCLs was not directly correlated with cell injury rates on epithelial and endothelial cells.

CONCLUSIONS

Both the New Dx HCL-136 and Suncon Mild II(TM), which have a common composition of graft co-polymer of dextran derivative, are less irritating to the epithelium and to the endothelium. Also a very few patients complaints regarding Suncon Mild II(TM) wearing in individuals with dry eyes have been reported. Therefore, we would expect that the New Dx HCL-136 should be satisfactory for wear by individuals with dry eyes.

Longitudinal studies of viral sequence, viral phenotype, and immunologic parameters of human immunodeficiency virus type 1 infection in perinatally infected twins with discordant disease courses

Perinatal human immunodeficiency virus type 1 (HIV-1) infections cause a broad spectrum of clinical disease and are variable in both the age of the patient at onset of serious disease and the progression of the clinical course. Heterozygotic perinatally infected twins with a marked difference in their clinical courses were monitored during the first 2 years of life. Twin B, the second-born twin, developed AIDS by 6 months of age and died at 22 months of age, while twin A remained minimally symptomatic through the first 2 years. Sequential blood specimens were obtained from the twins in order to characterize the immunologic properties of the children and the phenotypes and genotypes of the HIV-1 isolates at various times. Twin A developed neutralizing antibodies and a high-level antibody-mediated cellular cytotoxicity (ADCC) response, while twin B had no neutralizing antibody and a much lower ADCC response. The virus isolates obtained from the two children at various time points proliferated equally well in peripheral blood mononuclear cells, were nonsyncytium inducing, and could not infect established T-cell lines. They differed in their ability to infect primary macrophages. In parallel to the biological studies, the HIV-1 tat and part of the env gene sequences of the longitudinal isolates at four time points were determined. Sequences of virus from both twins at different time points were highly conserved; the viruses evolved at a similar rate until the last analyzed time point, at which there was a dramatic increase in sequence diversity for the sicker child, especially in the tat gene. Our results show that the viruses isolated at different times do not have significant changes in growth properties. The absence or low levels of neutralizing antibodies may correlate with disease progression in the twins.

Analysis of determinants of binding and transcriptional activation of the pisatin-responsive DNA binding factor of Nectria haematococca

Pisatin is a fungistatic isoflavonoid produced by garden pea. Field isolates of the ascomycete Nectria haematococca mating population VI (anamorph: Fusarium solani) that are highly virulent on pea have been found to possess the PDA1 gene encoding a pisatin detoxifying activity. Expression of PDA1 is specifically and highly induced by exposure of mycelia to pisatin. A pisatin-responsive DNA-binding activity has previously been identified with properties suggestive of a transcriptional regulator of PDA1. In this study, the sequence determinants for binding this pisatin-responsive factor (PRF) were localized to a 14-bp region through analysis of sequence alterations that reduced PRF binding. Using a homologous in vitro transcription system, a transcriptional activator of PDA1 was shown to be present in mycelial extracts that shared the sequence specificity characteristic of the PRF, indicating function of the DNA-binding protein in transcriptional control. A 70-kDa protein was shown to be a DNA-binding component of PRF by three independent assays for DNA-binding proteins: Southwestern (DNA-protein) blotting, UV-crosslinking, and binding to immobilized DNA. These results characterize a transcriptional activator acting on the PDA1 promoter that is responsive to a host-specific compound and provide insight into the regulation of fungal genes in response to plant flavonoids.

Quantitative three-dimensional reconstruction of left ventricular volume with complete borders detected by acoustic quantification underestimates volume

Recently a new acoustic-quantification (AQ) technique has been developed to provide on-line automated border detection with an integrated backscatter analysis. Prior studies have largely correlated AQ areas with volumes without direct comparison of volumes for agreement. By using complete AQ-detected borders as the input to a validated method for three-dimensional echocardiographic (3DE) reconstruction, we can compare an entire cavity volume measured with the aid of AQ against a directly measured volume. This would also explore the possibility of applying AQ to 3DE reconstruction to reduce tracing time and enhance routine applicability. To compare reconstructed volumes with actual values in a stable standard allowing direct volume measurement, the left ventricles of 13 excised animal hearts were studied with a 3DE system that automatically combines two-dimensional (2D) images and their locations. Intersecting 2D views were obtained with conventional scanning and AQ imaging, with gains optimized to permit 3D reconstruction by detecting the most continuous AQ borders for each view, with maximal cavity size. Reconstruction was performed with manually traced central endocardial reflections and AQ-detected borders visually reproduced the left ventricular shapes; the AQ reconstructions, however, were consistently smaller. The reconstructed left ventricular (LV) volumes correlated well with actual values by both manual and AQ techniques (r = 0.93 and 0.88, with standard errors of 2.3 cc and 2.0 cc, p = not significant [NS]). Agreement with actual values was relatively close for the manually traced borders (y = 0.93x + 0.68, mean difference = -0.8 +/-2.2 cc). AQ-derived reconstructions consistently underestimated LV volume by 39 +/- 10% (y = 0.62x-0.09, mean difference = -7.8 +/- 3.0 cc, different from manually traced and actual volumes by analysis of variance [ANOVA], F = 69, p<0.00001). The AQ-detected threshold signal was displaced into the cavity, and volume between walls and false tendons was excluded, leading to underestimation, which increased with increasing cavity volume (r = 0.76). The AQ technique can therefore be applied to 3DE reconstruction, providing volumes that correlate well with directly measured values in a stable in vitro standard, minimizing observer decisions regarding manual border placement after image acquisition. However, when the complete borders needed for 3D reconstruction are used, absolute volumes are underestimated with current algorithms that integrate backscatter and displace the detected threshold into the ventricular cavity.

Infection of primary human fetal astrocytes by human herpesvirus 6

Human herpesvirus 6 (HHV-6) is a lymphotropic betaherpesvirus which productively infects human CD4+ T cells and monocytes. HHV-6 is the etiologic agent for exanthem subitum (roseola), and it is well-known that central nervous system complications occur frequently during the course of HHV-6-associated disease. In addition, HHV-6 has been associated with encephalitis or encephalopathy. However, very little is known about its tropism for neural cells. There are reports that HHV-6 may infect some glial cell lines, but whether it can infect any primary neural cells is not known. Our studies show that both HHV-6A (GS) and HHV-6B (Z-29) can infect highly purified primary fetal astrocytes in vitro. Infected cells showed cytopathic effects, forming giant syncytia. In dual immunofluorescence assays, the infected cells were detected by antibodies against the HHV-6 p41 nuclear antigen and glial fibrillary acidic protein, indicating that the infected cells are indeed astrocytes. PCR and Northern (RNA) blot analyses also confirmed that the astrocytes are infected by HHV-6. The progeny virus did not alter its host range and could reinfect T cells as well as primary astrocytes. These findings suggest that infection of primary human astrocytes may play a role in the neuropathogenesis of HHV-6.

[230 cases of video-assisted thoracoscopic surgery]

We performed video-assisted thoracoscopic surgery (VATS) in 230 cases. As traditional technique is used in VATS, the operetive cost is lower, and more and more patients may accept VATS.

[Lobectomy by video-assisted thoracoscopic surgery]

Lobectomy by video-assisted thoracoscopic surgery (VATS) has been marked by decrease in pain, morbility, hospital stay, bleeding, and transfusion. This new way approach was performed on 10 dogs and 21 patients. In this paper we discuss how to deal with pulmonary vessels, bronchus and fissure. We suggested that Stage I lung cancer and lung disease were indicated of lobectomy by VATS.

Screening for dialysis access graft malfunction: comparison of physical examination with US

PURPOSE

To test the reliability and performance of two physical diagnosis algorithms for use in physical examination of vascular access grafts.

MATERIALS AND METHODS

Grafts were assessed in 39 patients by means of physical examination performed by four observers. Grafts were characterized as having a thrill, pulse, or indeterminate examination at three locations (arterial, midpoint, venous). Findings with this algorithm were compared with those from ultrasound (US) with volume flow measurements.

RESULTS

Patients with a thrill at all three locations of the graft all had volume flows greater than 450 mL/min (negative predictive value = 100%). Of patients with a pulse at any of three locations, only 28% (positive predictive value) had a volume flow of 450 mL/min or less.

CONCLUSION

Physical examination is a good screening test for ruling out the low flows associated with impending access graft failure, thereby eliminating the need for routine US for many patients.