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Biomedical subjects

R F Garry

Publications and source records attributed to R F Garry.

At least 37 records · Page 2Linked to original sources
PubMed1998

Detection of retroviral antibodies in primary biliary cirrhosis and other idiopathic biliary disorders.

BACKGROUND: Retroviruses have been implicated in the aetiology of various autoimmune diseases. We used immunoblots as a surrogate test to find out whether retroviruses play a part in the development of primary biliary cirrhosis. METHODS: We did western blot tests for HIV-1 and the human intracisternal A-type particle (HIAP), on serum samples from 77 patients with primary biliary cirrhosis, 126 patients with chronic liver disease, 48 patients with systemic lupus erythematosus, and 25 healthy volunteers. FINDINGS: HIV-1 p24 gag seroreactivity was found in 27 (35%) of 77 patients with primary biliary cirrhosis, 14 (29%) of 48 patients with systemic lupus erythematosus, 14 (50%) of 28 patients with chronic viral hepatitis, and nine (39%) of 23 patients with either primary sclerosing cholangitis or biliary atresia, compared with only one (4%) of 24 patients with alcohol-related liver disease or alpha1-antitrypsin-deficiency liver disease, and only one (4%) of 25 healthy volunteers (p=0.003). Western blot reactivity to more than two HIAP proteins was found in 37 (51%) of patients with primary biliary cirrhosis, in 28 (58%) of patients with systemic lupus erythematosus, in 15 (20%) of patients with chronic viral hepatitis, and in four (17%) of those with other biliary diseases. None of the 23 patients with either alcohol-related liver disease or alpha1-antitrypsin deficiency, and only one of the healthy controls showed the same reactivity to HIAP proteins (p<0.0001). Our results showed a strong association between HIAP seroreactivity and the detection of autoantibodies to double-stranded DNA. HIAP seroreactivity was also strongly associated with the detection of mitochondrial, nuclear, and extractable nuclear antigens. INTERPRETATION: The HIV-1 and HIAP antibody reactivity found in patients with primary biliary cirrhosis and other biliary disorders may be attributable either to an autoimmune response to antigenically related cellular proteins or to an immune response to uncharacterised viral proteins that share antigenic determinants with these retroviruses.

Autoantibodies↗
PubMed1998

Lupus erythematosus-like features in patients with cutaneous T-cell lymphoma.

BACKGROUND: The development of lupus erythematosus-like (LE-like) features in patients with cutaneous T-cell lymphoma (CTCL) has not been reported previously in the literature. Both diseases, however, have been etiologically linked to retroviruses. OBJECTIVE: Our purpose was to report four cases of patients with CTCL who developed LE-like features during the course of their disease, and to evaluate for evidence of antibodies to retroviruses in the sera of these patients. PATIENTS: Four patients with biopsy-proven CTCL with clinical or histologic features of systemic lupus erythematosus (SLE) were evaluated for clinical and laboratory criteria for SLE. Only one patient demonstrated four American Rheumatism Association (ARA) criteria sufficient for the diagnosis of SLE. The remaining three patients demonstrated one or two criteria for SLE. In addition, the sera of these patients were examined by Western blot analysis for evidence of human immunodeficiency virus type I (HIV-I), human T-cell lymphotrophic virus type I (HTLV-I), or human intracisternal A-type particle type I (HIAP-I) retroviral proteins. Each patient demonstrated antibodies to some of the retroviral proteins examined. The sera of two patients reacted to proteins for HIAP-I, and the sera of two patients reacted to p24 gag proteins of HIV-I. No patient reacted to HTLV-I proteins. CONCLUSIONS: Our report identifies four patients with CTCL who developed LE-like features during the course of their disease. Although the etiology of CTCL and SLE has not been well established, each has been linked to retroviruses. Evidence of antibodies to retroviral proteins was identified in each of our patients by Western blot analysis. Although the clinical and laboratory findings in these cases do not resolve the etiologic role of retroviruses in CTCL or SLE, they suggest that retroviruses may have a role in the pathogenesis of the clinical phenomenon reported in these four patients.

Aged↗
PubMed1998

Reactivity of sera from systemic lupus erythematosus and Sjögren's syndrome patients with peptides derived from human immunodeficiency virus p24 capsid antigen.

We have previously demonstrated that about one-third of patients with either Sjögren's syndrome (SS) or systemic lupus erythematosus (SLE) react to human immunodeficiency virus (HIV) p24 core protein antigen without any evidence of exposure to, or infection with, HIV itself. Herein, we further characterize the specificity of this reaction using enzyme-linked immunosorbent assay to peptides representing fragments of p24. Characteristic epitope-specific profiles were seen for SS and SLE patients. SS patients had significantly increased responses to peptides F (p24 amino acids 69 to 86) and H (amino acids 101 to 111) and diminished reactivity to peptides A (amino acids 1 to 16) and P (amino acids 214 to 228). SLE patients had increased reactivity to peptides E (amino acids 61 to 76), H, and P. Utilization of peptide P hyporeactivity as the criterion to select for SS patients results in a screen that is moderately sensitive (64%) and specific (79.3%). Adding hyperreactivity to one other peptide (F or H) as an additional criterion yields an expected decrease in sensitivity (to 41%) while increasing specificity (to 93.1%). All sera-reactive peptides from regions of known structure of HIV p24 were located in the apex of the p24 molecule. Thus, the specificity of the peptide reactivities described here indicates a specific pattern of a nonrandom cross-reactivity between HIV type 1 p24 and autoimmune sera which may be partially syndrome specific. The future focus of our work will be to optimize assays of the peptide as diagnostic tools.

Amino Acid Sequence↗
PubMed1997

A synthetic peptide corresponding to the carboxy terminus of human immunodeficiency virus type 1 transmembrane glycoprotein induces alterations in the ionic permeability of Xenopus laevis oocytes.

The carboxy-terminal 29 amino acids of the human immunodeficiency virus type 1 transmembrane glycoprotein (HIV-1 TM) are referred to as lentivirus lytic peptide 1 (LLP-1). Synthetic peptides corresponding to LLP-1 have been shown to induce cytolysis and to alter the permeability of cultured cells to various small molecules. To address the mechanisms by which LLP-1 induces cytolysis and membrane permeability changes, various concentrations of LLP-1 were incubated with Xenopus laevis oocytes, and two-electrode, voltage-clamp recording measurements were performed. LLP-1 at concentrations of 75 nM and above induced dramatic alterations in the resting membrane potential and ionic permeability of Xenopus oocytes. These concentrations of LLP-1 appeared to induce a major disruption of plasma membrane electrophysiological integrity. In contrast, concentrations of LLP-1 of 20-50 nM induced changes in membrane ionic permeability that mimic changes induced by compounds, such as the bee venom peptide melittin, that are known to form channel-like structures in biological membranes at sublytic concentrations. An analog of LLP-1 with greatly reduced cytolytic activity failed to alter the electrophysiological properties of Xenopus oocytes. Thus, by altering plasma membrane ionic permeability, the carboxy terminus of TM may contribute to cytolysis of HIV-1-infected CD4+ cells.

Animals↗
PubMed1997

Interaction of erythropoietin RNA binding protein with erythropoietin RNA requires an association with heat shock protein 70.

Synthesis of erythropoietin (Epo), the glycoprotein hormone that regulates red blood cell formation, is induced in response to low oxygen stress (hypoxia), and is regulated at both transcriptional and post-transcriptional levels. We have previously described an Epo RNA binding protein (ERBP) which specifically binds to the 3'-untranslated region of Epo mRNA and is likely involved in the regulation of Epo mRNA stability. Since heat shock proteins (hsps) are induced in response to a variety of stresses, including hypoxia, we tested the possibility that hsps are involved in ERBP-Epo RNA complex formation. When human anti-hsp70 antibody was added to ERBP-containing human hepatoma cell (Hep3B) lysates, the ERBP-Epo RNA complex was inhibited in an electrophoretic mobility band shift assay. In addition, the anti-hsp70 antibody-inhibited complex could be rescued if lysates were pretreated with purified inducible hsp70, but not with bovine serum albumin (BSA). In vivo studies using quercetin to inhibit hsp70 induction support the notion that hsp70 is involved in ERBP-Epo RNA complex formation. Taken together, these findings suggest involvement of hsp70 in ERBP-Epo mRNA complex formation, and our model suggests a novel role for hsps in the regulation of EPO mRNA stability.

Animals↗
PubMed1996

Biochemical characterization of the reverse transcriptase of a human intracisternal A-type particle (HIAP).

The discovery of novel human intracisternal A-type particle (HIAP) that may be associated with the autoimmune disease Sjŏgren's syndrome has been previously reported. Although the HIAP retrovirus has been shown to be antigenically related to HIV-1, the viruses were distinguishable by different hydrodynamic mobilities through a sucrose gradient by morphology and intracellular location, and by differing divalent cation requirements for their in vitro reverse transcriptase (RT) reactions. In this report, additional biochemical characteristics are provide that further differentiate the HIAP RT from HIV-1 RT. Data are also presented that distinguish the HIAP RT from the known cellular DNA polymerases.

Antiviral Agents↗
PubMed1996

Antibodies against retroviral proteins and nuclear antigens in a subset of idiopathic CD4+ T lymphocytopenia patients.

Idiopathic CD4+ T lymphocytopenia (ICL) is an immunodeficiency syndrome characterized by severe depletion of CD4+ T lymphocytes, but in which human immunodeficiency virus cannot be detected. Peripheral blood mononuclear cells (BPMCs) from an ICL patient were cocultured with HUT78 T-lymphoblastoid cells, and an acute cytopathic effect and formation of multinucleated cells were observed. A human intracisternal A-type retroviral particle designated HIAP-II was detected in cells surviving the acute cytopathic effect. Eight of 13 ICL patients in a blinded screen of a serological panel provided by the National Centers for Disease Control and Prevention (CDC) had serum antibodies that specifically reacted with HIAP-II associated proteins by Western immunoblotting. None of 19 control sera in the panel that were unreactive with HIV Gag proteins produced a positive result on HIAP-II immunoblots. Comparable results were obtained in a blinded screen of a second CDC serological panel. Sera from 8 of 14 ICL patients in the second serological panel were positive for antinuclear autoantibodies (ANAs) commonly observed in patients with systemic autoimmune diseases. These results suggest the possible involvement of an A-type retrovirus or autoimmunity in development of ICL in a subset of patients.

Adult↗
PubMed1996

Reduction of human immunodeficiency virus production and cytopathic effects by inhibitors of the Na+/K+/2Cl- cotransporter.

Infection of CD4+ T-lymphoblastoid cells by cytopathic strains of HIV-1 results in an increase in cell volume that leads to lysis and cell death. The increase in volume is attributable in part to an HIV-induced increase in intracellular monovalent ion concentrations mediated by the plasma membrane-associated Na+/K+/2 Cl- cotransporter. Loop diuretics, which inhibit cotransporter activity, blocked HIV-induced HIV production and cytopathic effects at physiologically employed concentrations.

Antiviral Agents↗
PubMed1996

Inhibition of Na+K+ATPase activity in membranes of Sindbis virus-infected chick cells.

Alterations in intracellular concentrations of Na+ and K+ in Sindbis virus-infected cells result largely from inhibition of ouabain-sensitive Na+K+ATPase (Na+ pump) activity. Here we report that membrane preparations derived from Sindbis virus-infected chick cells exhibit reduced Na+K+ATPase activity, indicating that limitation of cellular factors is not responsible for inhibition of ion transport. In vitro phosphorylation of the Na+K+ATPase by [32P]orthophosphate or [gamma 32P]ATP is unaltered in membranes of Sindbis virus-infected cells, indicating that a loss of specific enzymatic functions unrelated to formation of Na+ pump phosphoenzyme intermediates occurs during the course of viral infection. However, phosphoenzyme intermediates of the Na+K+ATPase prepared from membranes of Sindbis virus-infected cells are inherently less stable than those prepared with membranes of uninfected cells. The instability of these intermediates in vitro is correlated with an altered capacity of the Na+ pump to transport monovalent cations into virus-infected cells. 22Na+ transport studies reveal enhanced ouabain-sensitive Na+ uptake by Sindbis virus-infected cells, suggesting that the Na+ pump may catalyze enhanced Na+-Na+ exchange in the infected cells. These results indicate that the capacity of the Na+K+ATPase to discriminate between binding of extracellular Na+ and K+ is specifically altered during the course of infection by Sindbis virus.

Cell Membrane↗
PubMed1996

Activity of granzyme A, a serine protease in the killing granules of cytotoxic T lymphocytes, is reduced in cells from HIV-infected hemophiliacs.

Cytotoxic CD8+ lymphocytes (CTLs) kill virally infected target cells by releasing cytotoxic granules. The primary objective of this study was to determine whether the activity of granzyme A, a serine protease in the killing granules of CTLs is altered in HIV-infected hemophiliacs. A sensitive colorimetric assay that measures cleavage of a synthetic substrate, N alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester (BLT), was used to quantitate granzyme A activity. Granzyme A activities from hemophiliacs were normalized to to granzyme A activities of healthy donors run concurrently. Granzyme A activity in CD8+ T cells from HIV-seropositive hemophiliacs was significantly lower than granzyme A activity in cells from HIV-seronegative hemophiliacs (0.48 units +/- 0.086/CD8+ T cell and 1.573 +/- 0.434 units/CD8+ T cell, respectively; p < 0.005). These results indicate that cytotoxic cells in HIV-infected hemophiliacs have reduced granzyme A activity, which may result in a defect in CTL-mediated cell killing in these patients.

Cohort Studies↗
PubMed1996

On the crisis in biomedical education: is there an overproduction of biomedical PhDs?

The United States is the world leader in biomedical science (BMS) education and research. This preeminence is reflected in superior medical education, the attraction of U.S. educational institutions to foreign visitors seeking advanced training, and a high rate of transfer of knowledge between basic biomedical research and the delivery of health care at the bedside. The foundation for this excellence and leadership has been the research carried out by MD and PhD biomedical scientists. It has been suggested that there is now an oversupply of BMS PhDs, and thus that BMS PhD programs should be downsized. Full examination of the issues involved, including a case study of doctoral graduates and postdoctoral fellows at Tulane Medical Center, leads the authors to conclude that a biomedical PhD "glut" does not exist at the present time, that downsizing training programs would have a serious, long-term negative impact on biomedical research, and that medical school administrators and faculty should resist attempts to reduce biomedical research and training at the local and national level. However, times have changed and training programs must evolve to adapt to the technologic changes occurring in the workplace. Alternatives, such as new alliances with industry, must be sought to compensate for decreased resources at federal and institutional levels; new and innovative curricula must be developed to prepare biomedical scientists for nonacademic, as well as academic, job opportunities in the twenty-first century; and medical center administrators and faculties must work together to increase the visibility of BMS and stress its critical relationship to the research base of the nation.

Academic Medical Centers↗
PubMed1996

Human immunodeficiency virus infection of T-lymphoblastoid cells reduces intracellular pH.

Alterations in plasma membrane function are induced by many cytopathic viruses, including human immunodeficiency virus type 1 (HIV-1). These alterations can result in changes in the intracellular content of ions and other small molecules and can contribute to cytolysis and death of the infected cell. The pH-sensitive fluorescent probe 2',7'-bis(2-carboxyethyl)-5,6-carboxyfluorescein-acetoxymethyl ester was used to quantitate intracellular pH (pHi) in HIV-1-infected T cells. Infection of cells from the CD4+ T-lymphoblastoid line HUT-78 (RH9 subclone) with HIV-1 strain LAI resulted in a significant decrease of pHi, from approximately 7.2 in mock-infected cells to below 6.7 by day 4 after infection, when cells were undergoing acute cytopathic effects. The pHi in persistently infected cells that survived the acute cytopathic effects of HIV-1 was approximately 6.8 to 7.0. Studies with amiloride, an inhibitor of the Na+/H+ exchange system, suggest that HIV-1-induced intracellular acidification in lymphocytes is due, in part, to dysfunction of this plasma membrane ion transport system. The alterations in pHi may mediate certain cytopathic effects of HIV-1, thereby contributing to depletion of CD4+ T lymphocytes in patients with AIDS.

CD4-Positive T-Lymphocytes↗
PubMed1996

Alteration of intracellular potassium and sodium concentrations correlates with induction of cytopathic effects by human immunodeficiency virus.

Increases in intracellular concentrations of potassium ([K+]i) and sodium ([Na+]i) occur concomitantly with cytopathic effects induced in a CD4+ T-lymphoblastoid cell line acutely infected by human immunodeficiency virus (HIV). This [K+]i increase was greater in cells infected by cytopathic HIV strains than in cells infected by less cytopathic strains. T cells persistently infected by HIV had an increased [K+]i but displayed an [Na+]i similar to that of mock-infected cells. HIV induced increases in [K+]i and [Na+]i after cytopathic infection of human peripheral blood mononuclear cells, but the magnitude of the Na+ changes did not correlate with the extent of the cytopathic effect. Enhanced movement of cations may osmotically drive water entry, resulting in balloon degeneration and lysis of HIV-infected cells. These observations offer potential approaches for antiviral therapies.

CD4-Positive T-Lymphocytes↗
PubMed1996

The interaction of a type A retroviral particle and class II human leukocyte antigen susceptibility genes in the pathogenesis of Graves' disease.

We have previously reported that over 85% of patients with Graves' disease have detectable serum antibodies against a human intracisternal type A retroviral particle (HIAP), which are not present in age- and gender-matched controls, suggesting a role for HIAP in triggering the autoimmune process leading to Graves' disease. To investigate the interaction of this viral particle with genetic factors, 35 members of 3 kindreds, selected because of a high family prevalence of Graves' disease (a total of 11 members affected), were examined for clinical signs of thyroid dysfunction, goiter, and opthalmopathy. Thyroid function tests and autoimmune serological profiles were also obtained. In addition, subjects were tested for the presence of antibodies against HIAP by means of immunoblot analysis of their sera, and their human leukocyte antigen (HLA) class II alleles were determined by DNA methodology. Molecular genetic analyses enabled the detection of postulated HLA susceptibility haplotypes in each family. These families had 8, 4, and 5 members, respectively, with such apparent susceptibility genes and 11, 5, and 9 members, respectively, with immunological evidence of retroviral exposure. In the presence of both factors (codetected in a total of 15 members of the 3 kindreds), the incidence of Graves' disease was 100%, 67%, and 80%, respectively. One additional member of family B and 3 in family C with both viral and genetic susceptibility factors were found to have serological abnormalities and/or goiter and ocular signs consistent with evolving or preclinical Graves' disease. In families A and C, tight linkage between HLA haplotypes and Graves' disease was demonstrated in a manner consistent with recessive inheritance. The association between the occurrence of both anti-HIAP-I antibody positivity and HLA susceptibility and the presence of Graves' disease was highly significant (P < 0.001). The pathogenesis of Graves' disease in these families appears to be attributable to the interaction between the immune response to an intracisternal type A retroviral particle and immunogenetic susceptibility, leading to the autoimmune processes that underlie Graves' disease, with subsequent development of the characteristic features of the illness. Data from these families suggest that both of these factors are necessary for final disease expression. These results imply that serological evidence of retroviral exposure together with genetic HLA susceptibility are the two major predisposing factors underlying the pathogenesis of Graves' disease. Further studies will establish whether prospective identification of persons at risk for Graves' disease is possible by this means.

Adult↗
PubMed1995

A general model for the surface glycoproteins of HIV and other retroviruses.

A hypothetical model of the surface (SU) glycoproteins of human immunodeficiency virus (HIV) and other retroviruses is proposed. The model is based on repetition of a limited number of sequence motifs conserved within the virus family; similarities in biological, immunological, or genetic properties; as well as the tendency for regions of dissimilar sequence to share protein structures predicted by computer algorithms. It is proposed that the protein consists of three structural and functional domains interspersed by relatively conserved interdomain regions. For each retrovirus, these amino-terminal, central, and carboxy-terminal domains may play different roles in binding, postbinding events, and the immune response to viral infection.

Amino Acid Sequence↗
PubMed1995

Evidence for a retroviral trigger in Graves' disease.

An apparently high frequency of Graves' disease encountered in New Orleans, Louisiana, prompted an investigation for a possible infectious agent that might be triggering the disease in genetically susceptible individuals. We studied 40 patients with Graves' disease, and compared them to the following groups of controls: age and gender matched healthy subjects; patients with multinodular goiter (non-autoimmune thyroid controls); patients with chronic lymphocytic thyroiditis (autoimmune thyroid disease controls) and additional organ or tissue specific autoimmune controls exclusive of thyroid autoimmunity, including patients with Type I diabetes and other endocrine autoimmune complex disorders. Serum antibodies against a prototypic strain of a human intracisternal A-type retroviral particle type 1 (HIAP-1) were detected by a sensitive and specific immunoblotting assay. In 87.5% (35/40) of the Graves' disease patients there was a positive reaction against several HIAP-1-associated proteins, predominantly 97 Kd and 80 Kd, with only 5 showing no reactivity to any. In contrast, 2% (2/105) of sera from normal controls showed positive reactivity. Furthermore, only 10% (1/10) of sera from multinodular goiter control patients and 10% (1/10) of Hashimoto's patients showed reactivity (p < 0.0005). Sera from 3 of 20 (15%) of Type I diabetic patients none of whom had Graves' disease, showed reactivity but there was no reactivity in 9 other patients with one or more of the endocrine autoimmune complex disorders, including Addison's disease, vitiligo, myasthenia gravis and pernicious anemia. In addition we studied two individuals with Graves' disease from each of two families residing outside Louisiana, all of whom were positive for these antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Comparison of DNA fragmentation and color thresholding for objective quantitation of apoptotic cells.

Apoptosis is a process of cell death characterized by distinctive morphological changes and fragmentation of cellular DNA. Using video imaging and color thresholding techniques, we objectively quantitated the number of cultured CD4+ T-lymphoblastoid cells (HUT78 cells, RH9 subclone) displaying morphological signs of apoptosis before and after exposure to gamma-irradiation. The numbers of apoptotic cells measured by objective video imaging techniques were compared to numbers of apoptotic cells measured in the same samples by sensitive apoptotic assays that quantitate DNA fragmentation. DNA fragmentation assays gave consistently higher values compared with the video imaging assays that measured morphological changes associated with apoptosis. These results suggest that substantial DNA fragmentation can precede or occur in the absence of the morphological changes which are associated with apoptosis in gamma-irradiated RH9 cells.

Apoptosis↗