[Specificity of antiviral reactions of human immunodeficiency in heroin addicts].
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Antibody Specificity↗
Biomedical subjects
F Merino
Publications and source records attributed to F Merino.
[Absence of HTLV-1 infection in drug addicts in Vizcaya].
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HTLV-I Infections↗
Regulation of natural killer cytotoxicity by 1,25-dihydroxyvitamin D3.
The steroid hormone 1 alpha, 25-dihydroxyvitamin D3, calcitriol, is crucial in calcium homeostasis. Calcium plays a central role in T, B, and NK cell functions, and calcitriol is a known inhibitor of T cell proliferation and immunoglobulin production. We have analyzed here the immunoregulatory effects of calcitriol on NK cell function. We show that calcitriol specifically specifically inhibits, in a time- and dose-dependent fashion, the generation of cytotoxic activity from cultured CD16+ peripheral blood NK cells. It also suppresses, at similar molar concentrations (1-10 nM), interleukin 2 (IL-2) production by PHA-activated peripheral blood lymphocytes. Calcitriol does not interfere with the cytotoxic function of NK cells, whether fresh or generated in vitro, placing the inhibition at the level of NK cell activation. Interestingly enough, exogenous IL-2 can completely reverse the suppressive effect. These findings suggest that modulation of NK cell activation by control of the internal level of IL-2 may reflect an additional paracrine calcitriol-dependent circuit with immunoregulatory consequences.
Antigens, Differentiation↗
[Human immunodeficiency virus (HIV) infection in País Vasco, Spain].
An analysis of the epidemiology of the human immunodeficiency virus infection in the Basque Country, Spain is presented. The infection by this virus is mainly detected in intravenous drug addicts. In homosexuals the seropositivity frequency detected was moderate, and infection was also detected in sexual partners of drug addicts.
Acquired Immunodeficiency Syndrome↗
[Diseases in heroin addiction].
An analysis of the medical pathologies seen in heroin addicts heroin addicts hospitalized in the Provincia de Vizcaya, Basque Country, Spain, from 1982 to 1987, and its possible association to the infection by the human immunodeficiency virus, HIV, is presented. An increasing of hospitalized addicts per year was observed, being infectious diseases the main pathology detected. HIV infection was present in more than 90% of individuals with non opportunistic acquired infections. Significant annual increase in the number of tuberculosis and candida infections was present. The possible association of HIV infection with increased susceptibility to commonly acquired non opportunistic infections is discussed.
Follow-Up Studies↗
[Epidemiologic aspects of acquired immunodeficiency syndrome (AIDS). Review].
A revision of the World current epidemiological aspects of the acquired immunodeficiency syndrome is presented. It was observed that near 70% of all the world cases occurred in the United States of America and 12% in Europe. There is an increase tendency of the number of cases. However, the analysis of the inter-annual percentage increase showed a tendency to stabilization in Europe and in the United States of North America.
Acquired Immunodeficiency Syndrome↗
Interleukin-2 induces cytotoxic activity in lymphocytes from regional axillary nodes of breast cancer patients.
Natural killer (NK) cells and lymphokine-activated killer (LAK) cells have been involved in immunosurveillance against tumors. A normal NK activity was observed in peripheral blood (PB) mononuclear cells (MNC) from women with breast cancer, but a very low or absent NK cytotoxicity was found in the regional lymph node (RLN) MNC. However, strong cytotoxic activity against NK-resistant and NK-sensitive target cells can be induced in RLN MNC by long-term (5-day) incubation with recombinant interleukin-2 (rIL-2). This cytotoxic inducer effect of rIL-2, not observed with recombinant interferon gamma, was dose and time-dependent and was not associated with modifications in the low number of Leu 11+ or Leu 7+ cells present in the population. Both the lack of NK activity and the generation of rIL-2-activated killer cells can be readily demonstrated in either histologically affected or unaffected RLN. These results stress the value of the immunomodulators inducing cytotoxic activity in RLN MNC of patients with tumors, and are discussed in association with their possible therapeutical role.
Breast Neoplasms↗
Decreased TcR-CD3+ T cell numbers in healthy aged humans. Evidence that T cell defects are masked by a reciprocal increase of TcR-CD3- CD2+ natural killer cells.
While there is accumulating evidence to indicate the presence of functional abnormalities in T cells from aged healthy humans, their cellular basis remains unclear. By using two-color immunofluorescence and multiparameter flow cytometry we show that (a) the number of peripheral blood antigen receptor-positive (TcR-CD3+) T cells is significantly lower in aged than in young adults; (b) the numbers of E-rosette-forming (CD2+) cells are maintained in the elderly due to a reciprocal increase in the frequency of TcR-CD3- cells, which constitute only a minor lymphocyte subpopulation in young adults, and (c) TcR-CD3-CD2+5- lymphocytes exhibit the phenotypic features of natural killer (NK) cells. By using functional assays we show the TcR-CD3-CD2+16+ lymphocytes are indeed NK cells because they are activated by and lyse NK targets. In contrast, they are unresponsive to either phytohemagglutinin or mitogenic CD2 monoclonal antibody stimulation, which in turn activates TcR-CD3+CD2+16- T cells. We conclude that the increase in TcR-CD3-CD2+ NK cells masks the T cell reduction in aged humans by normalizing CD2+ cell frequencies. However, NK cells cannot functionally substitute the thymus-derived lymphocytes they replace.
Aged↗
Antibodies to HTLV-III/LAV in Venezuelan patients with acute malarial infections.
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Acute Disease↗
Chronic active Epstein-Barr virus infection in patients with Chediak-Higashi syndrome.
The results of clinical and Epstein-Barr virus (EBV) serological studies on nine Chediak-Higashi syndrome (CHS) patients are reported. Persistently elevated antibodies to the viral capsid antigen (VCA) and the restricted component of the early antigen complex (EA-R) developed in six patients who experienced primary EBV infection which either remained silent or were accompanied by clinical signs of infectious mononucleosis (IM). Hepatosplenomegaly and moderate lymphadenopathy, both clinical signs of the accelerated phase, remained detectable in the six patients for a long period of time after seroconversion. The clinical, serological, and histopathological observations are suggestive of a nonmalignant lymphoproliferative disease and consistent with an immunodeficiency to EBV. The abnormal serological responses to EBV in CHS are therefore considered manifestations of a chronic active EBV infection which may result in lethal lymphoproliferation. The three as yet seronegative CHS patients revealed no signs of the accelerated lymphoproliferative phase of the syndrome.
Adolescent↗
Chediak-Higashi syndrome: immunological responses to Epstein-Barr virus studies in gene heterozygotes.
Immunologic studies were performed in five fathers and nine mothers of patients with Chediak-Higashi Syndrome (CHS). Antibody response to Epstein-Barr virus capsid antigen was higher than in normal controls. Antibodies to diffuse component of the early antigen were not detected and serum antibodies to the restricted component of the early antigen were observed in 64% of the subjects studied. Low natural killer activity and increased proportions of OKT8 positive cells were increased. These data indicate that immunologic alterations similar to those seen in CHS patients can be observed in their asymptomatic parents.
Antibodies, Viral↗
Anti-Epstein-Barr virus memory T-cell response in Chediak-Higashi syndrome patients.
Memory cytotoxic T-cell responses to Epstein-Barr virus transformed B cells were studied in two EBV seropositive Chediak-Higashi syndrome patients who were manifesting the terminal lymphoproliferative stage of the syndrome. The number of cells required for 50% regression of EBV-infected autologous lymphoblastoid cell lines was similar to that in the parents and healthy subjects. This indicates adequate memory cytotoxic T-cell control of EBV-infected B lymphocytes. Defective mechanisms other than those mediated by circulating cytotoxic cells, might be responsible for the chronic active EBV infection observed in these patients.
B-Lymphocytes↗
Antibodies to AIDS-associated retrovirus (HTLV-III/LAV) in drug addicts from Vizcaya, northern Spain.
Serum samples from 313 asymptomatic intravenous (IV) drug users from Bilbao (Vizcaya, Vasque Country, Spain) were tested for antibodies to HTLV-III/LAV virus, the probable etiologic agent of the acquired immune deficiency syndrome (AIDS). Viral antibodies were assayed by ELISA test. 41.9% of the sera gave positive reactions. No seropositivity was detected among 22 normal blood donors, 58 chronic alcoholics, or 20 members of the Drug Control Center personnel. Virus specific reactions were confirmed by indirect immunofluorescence using an HTLV-III/LAV producer cell line, and by Western blotting. 55% of the ELISA-positive sera were also positive in Western blot assay. No differences in seropositivity by age or sex were observed but it increased with the period of parenteral drug use. Presence of antibody statistically correlated with the frequency of syringe sharing, confirming the transmission of viral infection by blood products. Altered T4/T8 ratios and lower number of T4 positive lymphocytes were detected among HTLV-III/LAV positive drug addicts.
Adolescent↗
Antibodies to acquired immune deficiency syndrome (AIDS)-associated virus (HTLV-III/LAV) in Venezuelan populations.
Serum samples from 850 individuals from Venezuela were tested for the presence of antibodies to HTLV-III/LAV virus, the probable etiological agent of acquired immune deficiency syndrome (AIDS). At the time of the study, none of the individuals tested had symptoms indicative of AIDS or related disorders. Viral antibodies were assayed by indirect immunofluorescence (IF) assay, using a chronically infected, HTLV-III/LAV producer cell line CEM/LAV-NIT established in our laboratory. Twenty individuals (2.5%), 8 of them (40%) female, were seropositive by IF and by confirmatory Western blotting and radioimmunoprecipitation assays. The seropositivity rate ranged from 2.4% (11 of 465) in the general healthy population, 4% (2 of 50) among patients with Chagas' disease, and up to 29.2% (7 of 24) among patients with acute malaria infection. The titers of HTLV-III/LAV antibodies ranged from 1:40 to 1:640. In addition, 2 of 36 patients with hemophilia A (5.5%) also had antibodies to HTLV-III/LAV. Two of 7 patients with acute malaria had specific antibodies both to HTLV-III/LAV and HTLV-I, as determined by IF and Western blotting. None of over 169 randomly chosen, healthy blood donors from seven major Venezuelan cities, as well as none of 99 patients with leukemia/lymphoma, had antibodies to HTLV-III/LAV. The presence of specific antibodies among various Venezuelan populations indicates that HTLV-III/LAV, or a closely related cross-reactive virus, is indigenous in Latin American subjects as was previously indicated for tropical populations of central Africa. Isolation and characterization of this virus will help to understand the origin and etiology of AIDS.
Acquired Immunodeficiency Syndrome↗
Immunoregulatory alterations in Plasmodium falciparum and Plasmodium vivax infections.
Studies on the immune function of patients with acute Plasmodium vivax or P. falciparum infections were performed. All subjects were residing in recent malaria endemic areas of Venezuela. Lymphopenia, reduction of peripheral blood T-lymphocytes positive for monoclonal antibody OKT4 (T helper) a decrease of in vitro mitogenic proliferative response and natural killer cell activity were observed. Serum lymphocytotoxic antibodies reactive at 37 degrees C were detected in both groups of patients as well as serum autoantibodies. The possible role of lymphocytotoxic autoantibodies in the etiology of the T-lymphocyte depletion and acquired immunological perturbations in human malaria is discussed.
Antilymphocyte Serum↗
Antibodies to HTLV-III/LAV among aboriginal Amazonian Indians in Venezuela.
Serum samples from 224 aboriginal Amazonian Indians were tested for antibodies to HTLV-III/LAV by an indirect immunofluorescence (IF) assay. 9 individuals (4%), 5 of them female, were seropositive by IF and by confirmatory western blotting and radioimmunoprecipitation tests. 3 of the positive sera were collected in 1968. HTLV-III/LAV seropositivity rates varied among the ethnic groups and ranged from 13.3% among the Pemon Indians to 3.3% among the Yanoama tribe. The titres of HTLV-III/LAV antibodies ranged from 1/40 to 1/320. All individuals tested were apparently healthy at the time of the study. None of 211 randomly chosen, healthy blood donors from Venezuelan cities had antibodies to HTLV-III/LAV. The prevalence of specific antibodies among Amazonian Indians suggests the HTLV-III/LAV or a closely related cross-reactive virus may be endemic in this area. The findings also indicate that this virus is indigenous in non-negroid Latin American and negroid tropical populations.
Antibodies, Viral↗
Immunodeficiency and stomach cancer.
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Humans↗
Chédiak-Higashi syndrome in a Venezuelan black child.
One case of Chédiak-Higashi syndrome (CHS) in a black male child, born to a consanguineous couple from a rural village in the State of Falcón, is described. At birth the child had marked skin depigmentation and ash-gray hair. A few months later he developed an almost normal black skin color. The diagnosis of CHS was established by the presence of large peroxidase-positive granules in his leukocytes. Neutrophils showed decreased chemotaxis and lack of digestive capacity against Candida albicans. Unusual features included extreme rarity of CHS in blacks, progressive repigmentation of the skin, and an early benign evolution. A high consanguinity index in the village from which this patient originated raised the possibility of the presence of a new cluster of this disease in Venezuela.
Black or African American↗