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IL-15 plays a major role in the persistence of Tax-specific CD8 cells in HAM/TSP patients

Azimi, Nazli; Nagai, Masahiro; Jacobson, Steven; Waldmann, Thomas A.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: text
Português
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IL-15 is a critical cytokine for the maintenance of memory-phenotype CD8 cells in mice. Here, we investigated the role of IL-15 in the neurological disease termed human T cell lymphotropic virus I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The high number of viral-specific CD8 cells in these patients is associated with inflammatory responses in the central nervous system. Because IL-15 is overexpressed in these patients, we asked whether IL-15 contributes to the persistence of human T cell lymphotropic virus I viral-specific CD8 cells. Using ex vivo cultures of HAM/TSP peripheral blood mononuclear cells, we demonstrated that in the majority of patients examined here blocking IL-15 action resulted in a decrease in the number of viral-specific CD8 cells. This decrease was caused by both inhibition of proliferation and induction of apoptosis in these cells. The data indicate that IL-15 plays a major role in the maintenance of viral-specific CD8 cells in HAM/TSP.

Genetic Regulation of Acquired Immune Responses to Antigens of Mycobacterium tuberculosis: a Study of Twins in West Africa

Jepson, Annette; Fowler, Amanda; Banya, Winston; Singh, Mahavir; Bennett, Steve; Whittle, Hilton; Hill, Adrian V. S.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: text
Publicado em /06/2001 Português
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The role of genetic factors in clinical tuberculosis is increasingly recognized; how such factors regulate the immune response to Mycobacterium tuberculosis in healthy individuals is unclear. In this study of 255 adult twin pairs residing in The Gambia, West Africa, it is apparent that memory T-cell responses to secreted mycobacterial antigens (85-kDa antigen complex, “short-term culture filtrate,” and peptides from the ESAT-6 protein), as well as to the 65-kDa heat shock protein, are subject to effective genetic regulation. The delayed hypersensitivity response to intradermal tuberculin also demonstrates significant genetic variance, while quantitative T-cell and antibody responses to the 38-kDa cell membrane protein appear to be determined largely by environmental factors. Such findings have implications for vaccine development.

Expression of CD40 identifies a unique pathogenic T cell population in type 1 diabetes

Wagner, David H.; Vaitaitis, Gisela; Sanderson, Richard; Poulin, Michelle; Dobbs, Cathleen; Haskins, Kathryn
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: text
Português
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Juvenile diabetes (type 1) is an autoimmune disease in which CD4+ T cells play a major role in pathogenesis characterized by insulitis and β cell destruction leading to clinical hyperglycemia. To date, no marker for autoimmune T cells has been described, although it was previously demonstrated that autoimmune mice have a large population of CD4+ cells that express CD40. We show here that established, diabetogenic T cell clones of either the Th1 or Th2 phenotype are CD40-positive, whereas nondiabetogenic clones are CD40-negative. CD40 functionally signals T cell clones, inducing rapid activation of the transcription factor NFκB. We show that autoimmune diabetes-prone nonobese diabetic mice have high levels of CD40+CD4+ T cells in the thymus, spleen, and importantly, in the pancreas. Finally, as demonstrated by adoptive transfers, CD4+CD40+ cells infiltrate the pancreatic islets causing β-cell degranulation and ultimately diabetes.

Bacterial adhesion: modulation by antibiotics which perturb protein synthesis.

Schifferli, D M; Beachey, E H
Tipo: text
Publicado em /11/1988 Português
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Variation in Nitrogen Utilization in Acremonium coenophialum Isolates †

Ferguson, N. H.; Rice, J. S.; Allgood, N. G.
Tipo: text
Publicado em /11/1993 Português
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Acremonium coenophialum, a fungal endosymbiont in tall fescue, is responsible for the production of alkaloid toxins. Animals grazing endophyte-infected tall fescue often show toxicosis. In marginal environments, the endophyte is important for long-term survival of tall fescue. Few differences in endophyte isolates from individual tall fescue plants have been reported. To aid development of a toxicosis-free tall fescue, it is important to identify differences in endophyte isolates. This report describes variation in nitrogen utilization in a defined culture medium by endophyte isolates from Kentucky-31 tall fescue. Overall, the best nitrogen sources for dry weight production of mycelium were proline and potassium nitrate. Thirty-four isolates grown on agar-solidified defined media with single nitrogen sources showed variation in nitrogen utilization. Fifty percent of the isolates were unable to utilize two or more amino acids. Manipulation of endophyte variation could lead to development of a toxicosis-free tall fescue cultivar.

Differentiation of pathogenic Entamoeba histolytica infections from nonpathogenic infections by detection of galactose-inhibitable adherence protein antigen in sera and feces.

Abd-Alla, M D; Jackson, T F; Gathiram, V; el-Hawey, A M; Ravdin, J I
Tipo: text
Publicado em /11/1993 Português
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We determined whether epitope-specific monoclonal antibodies to the galactose-inhibitable adherence protein (GIAP) of Entamoeba histolytica could be used in an enzyme-linked immunosorbent assay (ELISA) to detect antigen in serum and feces and differentiate between nonpathogenic zymodemes and the potentially invasive pathogenic organisms that require treatment. Overall, 57% of subjects from Cairo, Egypt, with symptomatic intestinal amebiasis and 42% with asymptomatic infection possessed GIAP antigen in their sera, whereas 4% of uninfected controls or subjects with other parasitic infections possessed GIAP antigen in their sera (P < 0.001). In subjects from Durban, South Africa, only 6% of uninfected controls or those with nonpathogenic E. histolytica infection were positive for GIAP in serum, whereas 3 of 4 with asymptomatic pathogenic intestinal infection and 75% with amebic liver abscess were positive for GIAP in serum. Fifteen stool samples from patients with intestinal amebiasis were available for study; all had a positive ELISA result for fecal GIAP antigen. Epitope-specific monoclonal antibodies identified 8 of 15 subjects with fecal antigen from pathogenic strains. Seven of those eight subjects had adherence protein antigen in their sera...

Control of aldosterone secretion during sodium restriction: Adrenal receptor regulation and increased adrenal sensitivity to angiotensin II

Aguilera, G.; Hauger, R. L.; Catt, K. J.
Tipo: text
Publicado em /02/1978 Português
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The mechanism of increased adrenal sensitivity to angiotensin II during the aldosterone response to sodium restriction was investigated in the rat. Sodium restriction for 36 hr markedly increased the aldosterone-stimulating effect of low-dose (1 ng/min) infusion of angiotensin II and caused enhanced binding of 125I-labeled angiotensin II to the zona glomerulosa in vivo. Conversely, in vivo binding of 125I-labeled angiotensin II was significantly decreased after 36 hr of high-sodium intake. In isolated glomerulosa cells, the increased binding of angiotensin II after sodium restriction was shown to result from a significant increase in receptor affinity (+80%) and a smaller increase in receptor concentration (+25%). The corresponding aldosterone responses in dispersed cells showed an increase in sensitivity to angiotensin II, commensurate with the increased receptor affinity. More prolonged sodium restriction (4 days) caused a further increase in angiotensin receptor concentration (+70%) and maximal aldosterone response (+50%), whereas the binding affinity of adrenal receptors and the sensitivity of the in vitro aldosterone response had returned to normal. During sodium loading for 36 hr and 4 days, the converse effects on adrenal angiotensin II receptors and aldosterone production were observed. Also...

Haemodynamic effects of terbutaline in chronic obstructive airways disease.

Teule, G J; Majid, P A
Tipo: text
Publicado em /07/1980 Português
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Terbutaline, a cardioselective beta-adrenoceptor agonist, administered intravenously (250 micrograms) to seven patients with chronic obstructive airways disease (mean FEV1 0.99 l) resulted in reduction of mean pulmonary artery pressure (resting 23 +/- 2 to 19 +/- 2 mmHg, p < 0.05; exercise 43 +/- 3 to 35 +/- 3 mmHg, p < 0.05) and calculated pulmonary vascular resistance (resting 168 +/- 27 to 109 +/- 17 dyne s cm-5, p < 0.01; exercise 170 +/- 30 to 119 +/- 18 dyne s cm-5, p < 0.01) accompanied by an increase in heart rate (resting 86 +/- 5 to 96 +/- 4 per min, p < 0.01; exercise 108 +/- 2 to 114 +/- 2 per min, p < 0.01) and cardiac output (resting 3.7 +/- 0.4 to 4.1 +/- 0.4, p < 0.05; exercise 4.9 +/- 0.06 to 6.1 +/- 6 l, min-1 m-2, p < 0.05). The haemodynamic changes were associated with an increase in resting peak expiratory flow rate (184 +/- 20 to 216 +/- 25 l/min, p < 0.01), while the calculated indices of ventilation/perfusion relationship remained essentially unchanged. The reduction in mean pulmonary artery pressure after terbutaline observed in the present studies was probably the result of a combination of simple vasodilator effect, the reduction in airways resistance, and increase in the ventilation.

Epidemiology and Prevention of Hepatitis B Virus Infection

Hou, Jinlin; Liu, Zhihua; Gu, Fan
Fonte: Ivyspring International Publisher Publicador: Ivyspring International Publisher
Tipo: text
Publicado em 05/01/2005 Português
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Hepatitis B is one of the most common infectious diseases globally. It has been estimated that there are 350 million chronic hepatitis B virus (HBV) carriers worldwide. The prevalence of chronic HBV infection varies geographically, from high (>8%), intermediate (2-7%) to low (

Diplomatosis.

Brown, N
Tipo: text
Publicado em /03/1991 Português
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David John Woolford

Woolford, Marcus
Fonte: BMJ Publishing Group Ltd. Publicador: BMJ Publishing Group Ltd.
Tipo: text
Publicado em 18/03/2006 Português
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Employment problems of diabetics1

Engel, H O
Tipo: text
Publicado em /12/1984 Português
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Myocardial lesions in pheochromocytoma.

Silver, M D
Tipo: text
Publicado em 15/01/1990 Português
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The Week

Tipo: text
Publicado em 30/04/1983 Português
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Skin grafts for burns

Nanchahal, Jagdeep; Davies, Dai
Tipo: text
Publicado em 16/02/1991 Português
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Radiology as a Career

Davidson, J. W.
Tipo: text
Publicado em 12/02/1972 Português
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Cerebral Palsy in Childhood and Adolescence

Tipo: text
Publicado em /08/1962 Português
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Limitations of immunofluorescence tests in the diagnosis of infectious mononucleosis *

Joncas, J. H.; Gilker, J. C.; Chagnon, A.
Tipo: text
Publicado em 06/04/1974 Português
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The relative value of heterophil agglutinins (HA) and of specific EBV antibodies in the diagnosis of infectious mononucleosis (IM) was assessed in 108 cases of the disease and in 280 controls. Among the 108 cases 93 were HA-positive by sheep cells in at least one of their sera, while 15 were HA-negative by the same test. Among the 280 controls false-positive HA tests were not encountered except in eight cases with the horse cell microtitre tests. With one of the two slide tests at least two false-positive tests and 12 false-negative tests were also found but these sera had low titres in microtitre tests. The HA life-span was found to be unexpectedly long in a few cases, sheep cell HA lasting up to 8 to 10 months and horse cell HA up to 21 to 23 months.

Clinic Doctors

Lynn, C. R.
Tipo: text
Publicado em 25/02/1961 Português
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THE INFLUENCE OF SEXUAL MATURITY UPON THE REACTIVITY OF RABBITS TO HORSE SERUM

Schultz, Mark P.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: text
Publicado em 31/08/1934 Português
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1. Normal rabbits in the course of their development, after infancy, vary in their responses to minute doses of horse serum given intracutaneously. 2. There is increased reactivity in males as they mature, beginning, in the stock employed in these experiments, at about the age of 13 weeks when a weight of 1,700 gm. has been attained. 3. The reactivity of normal females remains at a constant level and the increase demonstrated in males does not take place. 4. The divergence in degree of reactivity between males and females, beginning with the establishment of estrus, indicates that factors associated with sexual maturity in females are responsible for their low reactivity. 5. The suppression of estrus by operative removal of the ovaries results in an increase of reactivity which, however, in the experiments reported here is probably not great enough to account entirely for the difference in reactivity between mature males and females.