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V Daniel

Publications and source records attributed to V Daniel.

At least 91 records · Page 5Linked to original sources
PubMed1992

Two adjacent AP-1-like binding sites form the electrophile-responsive element of the murine glutathione S-transferase Ya subunit gene.

An electrophile-responsive element (EpRE) in the 5' flanking region of the mouse glutathione S-transferase Ya subunit gene was recently found to be responsible for the induction of gene expression by xenobiotics that contain or acquire by metabolism an electrophilic center. We now find that this EpRE is composed of two adjacent 9-base-pair motifs related in sequence to the AP-1 binding site, a transcriptional enhancer originally identified as the phorbol 12-myristate 13-acetate (PMA) response element and known to be regulated by the binding of protein products of c-jun and c-fos genes. Synthetic oligonucleotides representing each of the AP-1-like binding sites of the EpRE and the AP-1 site consensus sequence were prepared and assayed for their enhancer activity and inducibility by tert-butylhydroquinone, beta-naphthoflavone, and PMA. Single AP-1-like sequences showed a lower enhancer activity than an AP-1 consensus sequence and no inducibility. Two adjacent AP-1-like sites were found to act synergistically and to confer inducibility beyond that observed for a single AP-1 consensus sequence. Examination of the PMA-responsive region of a number of genes shows the presence of adjacent AP-1-like sites and indicates that the structure of the EpRE found in the Ya gene may occur more generally and may be important in regulating the magnitude of the electrophilic response. The present study demonstrates the binding and transactivation of the EpRE by Jun and Fos and indicates that the AP-1 site is part of the EpRE. The induction by PMA or tert-butylhydroquinone appears to be independent of protein kinase C activity since it is not affected by inhibitors of this enzyme.

Animals↗
PubMed1992

T4+ cell numbers are correlated with plasma glutamate and cystine levels: association of hyperglutamataemia with immunodeficiency in diseases with different aetiologies.

Human immunodeficiency virus type 1 (HIV-1) seropositive individuals suffer from a depletion of T4+ T cells and have elevated plasma glutamate levels. Glutamate is also elevated in cancer patients, and several authors have shown that elevated extracellular glutamate levels inhibit competitively the membrane transport of cystine and cause a decrease of intracellular cystine. We, therefore, tested the hypothesis that high glutamate and/or low cystine levels may generally be associated with low lymphocyte reactivity or low T4+ counts. In three independent studies we tested (i) serum amino acid levels (AAL) versus T4+ counts in healthy individuals, (ii) plasma AAL versus lymphocyte responses in healthy individuals, and (iii) plasma AAL versus T4+ counts in HIV-1 seropositive individuals. When the individuals in each study were divided into four subgroups as defined by median glutamate and cystine levels, the results showed that persons with a combination of low glutamate and high cystine level (LGHC subgroups) had the highest mean T4+ count or highest lymphocyte reactivity. Moreover, the LGHC subgroup in a study of lung cancer patients had a much longer mean survival time than the other three subgroups. In HIV-1 infected patients, hyperglutamataemia is associated with hypocystinaemia and hypocysteinaemia. Azidodeoxythymidine (AZT) treated HIV patients had, on average, lower glutamate levels than patients without AZT.(ABSTRACT TRUNCATED AT 250 WORDS)

CD4-Positive T-Lymphocytes↗
PubMed1992

Soluble IL-2 receptor and tumour necrosis factor-alpha in plasma of haemophilia patients infected with HIV.

We measured plasma concentrations of soluble receptors for IL-2 (sIL-2R) and tumour necrosis factor-alpha (TNF-alpha) in 149 haemophilia patients. Soluble IL-2R levels were elevated in 37% of 62 HIV-seronegative patients (mean 570 +/- 27 U/ml versus 361 +/- 17 U/ml in the control group, P less than 0.0001), in 78% of 68 HIV-seropositive patients (928 +/- 49 U/ml, P less than 0.0001), and in 95% of 19 AIDS/ARC patients (1578 +/- 199 U/ml, P less than 0.0001 compared with controls and with HIV-seronegative patients; P less than 0.005 compared with HIV-seropositive asymptomatic patients). A negative correlation was observed between sIL-2R, relative and absolute numbers of CD4+ cells (P less than 0.0001), and CD4/CD8 ratios (P less than 0.0001). There was also a negative correlation between sIL-2R in plasma and the cellular expression of IL-2R (P less than 0.001). We found a significant association of sIL-2R and plasma neopterin (P less than 0.0001). With progression of the disease from HIV-seronegative to seropositive without symptoms and to full manifestation of AIDS/ARC, sIL-2R plasma levels increased. The highest levels were found at the time of diagnosis of AIDS/ARC, but the levels decreased again during the following 18 months. Eight per cent of HIV-seronegative patients, 32% of HIV-seropositive patients, and 24% of patients with AIDS/ARC had increased plasma TNF-alpha. We conclude that sIL-2R and TNF-alpha plasma levels are elevated in HIV-infected haemophilia patients and that sIL-2R is a marker for disease progression from asymptomatic HIV-seropositive to AIDS/ARC.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Autoantibodies in HIV-infected hemophilia patients against different epitopes on CD4+ lymphocytes and recombinant CD4.

We studied 684 sera obtained from 20 hemophilia patients with AIDS/AIDS-related complex (ARC), 89 asymptomatic HIV+, 76 HIV- hemophilia patients and 151 healthy controls for antibodies against recombinant CD4 (rCD4). Twenty-two percent of AIDS/ARC patients, 10% of asymptomatic HIV+ patients, 17% of HIV-patients, and 1% of healthy controls had anti-rCD4 antibodies. Purified anti-rCD4 antibodies did not react with human CD4+ lymphocytes. This may explain why formation of anti-rCD4 antibodies correlated neither with the occurrence of autoantibodies against CD4+ lymphocytes nor with a decrease in CD4+ cell counts. Antibodies that were eluted from CD4+ lymphocytes after sequential adsorption and elution with separated CD8+ and CD4+ cells reacted with CD4+ lymphocytes of only some healthy individuals, suggesting diversity of CD4 expression.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Anti-IgG autoantibodies in HIV-infected hemophilia patients.

Sera of 76 HIV-negative hemophilia patients, 103 HIV-positive (HIV+) hemophilia patients free of AIDS or AIDS related complex (ARC), and 32 HIV+ hemophilia patients with AIDS/ARC were tested for four different anti-IgG activities. IgG-anti-F(ab')2 gamma, IgM-anti-F(ab')2 gamma, and IgG-anti-Fc gamma serum activities were significantly associated with the clinical stage of HIV infection, whereas IgM-anti-Fc gamma was not. IgG-anti-F(ab')2 gamma activity was found to be caused by cross-reaction of anti-HIV antibody with an epitope within the constant CH1 domain of human IgG. HIV+ hemophilia patients with severe thrombocytopenia (less than 50,000/microliters platelet counts) had significantly higher IgM-anti-IgG activity than patients with greater than 50,000/microliters platelets. Because anti-IgG antibodies possess immunoregulatory properties, our results may serve as a possible explanation for the frequent B cell disorders encountered in HIV-infected patients.

AIDS-Related Complex↗
PubMed1992

Characterization of in vitro translated human mineralocorticoid receptor. Structure and activation.

The structures of the unactivated and activated mineralocorticoid receptors have been difficult to characterize because of receptor lability and steroid dissociation. Therefore, human mineralocorticoid receptor mRNA was translated in rabbit reticulocyte lysate in the presence and absence of [35S]methionine to compare the structure of [3H]aldosterone-bound and [35S]labeled receptor. In vitro synthesized receptor was able to specifically bind [3H]aldosterone. Unactivated [3H]aldosterone-bound and 60% of unactivated [35S]labeled receptor eluted from DEAE-cellulose with 250 mM salt and had a Rs of 72A. Forty percent of unactivated [35S]labeled receptor eluted from DEAE-cellulose with 100 mM salt and had a Rs of 54A. SDSPAGE showed intact hMR was present in both DEAE-cellulose eluates as three bands between M(r) 110,000-120,000. However, the low salt eluate contained less intact receptor and more lower MW bands. Neither [3H]aldosterone-bound nor [35S]labeled receptor was activated by incubation at 25 degrees C as readily as glucocorticoid receptor studied under identical conditions. Activated [3H]aldosterone-bound receptor eluted from DEAE-cellulose at 100 mM salt and had a Rs of 37A. After activation, 60% of [35S]labeled receptor eluted from DEAE-cellulose with 100 mM salt and had a Rs of 91A. SDS-PAGE of the high and low salt DEAE-cellulose eluates showed that 50% of intact receptor eluted in the low salt peak after activation. These data indicate that: 1. Some in vitro synthesized mineralocorticoid receptor assembles into the heteromeric unactivated form; 2. The remaining intact receptor remains monomeric and unable to bind steroid; 3. Activation causes dissociation of intact receptor from a larger complex; and 4. Activated receptor tends to aggregate.

Aldosterone↗
PubMed1991

Cell-free synthesis of rat glucocorticoid receptor in rabbit reticulocyte lysate. In vitro synthesis of receptor in Mr 90,000 heat shock protein-depleted lysate.

The glucocorticoid receptor is present in the cytosol of cell extracts as a large nonactivated (i.e. non-DNA-binding) approximately 9 S (Mr 300,000) complex. Experimental evidence indicates that the purified nonactivated glucocorticoid receptor contains a single steroid-binding protein and two approximately 90-kDa nonsteroid-binding subunits identified as heat shock protein (hsp) 90. Translation of the glucocorticoid receptor mRNA in vitro in reticulocyte lysates produces a large nonactivated glucocorticoid receptor complex similar to that found in cytosols. The cell-free synthesized glucocorticoid receptor is able to bind steroid and can be activated further to the DNA-binding form. To test the hypothesis of an active role played by hsp90 in the stabilization of a competent steroid-binding conformation of the glucocorticoid receptor, we have synthesized the receptor in a reticulocyte lysate that has been depleted of hsp90 by immunoadsorption with AC88 anti-hsp90. Although the translation capacity of the reticulocyte system was reduced considerably upon hsp90 removal, the glucocorticoid receptor was synthesized, and a significant number of molecules were found to bind [3H]triamcinolone acetonide. Chromatography on DEAE-cellulose showed that most of the receptor molecules synthesized in hsp90-depleted lysate had lost the capacity to form an oligomeric receptor complex. Addition of purified rat liver hsp90 to the hsp90-depleted lysate before translation did not increase steroid binding nor did it restore formation of the heteromeric receptor complex. Analysis of [35S] methionine-labeled glucocorticoid receptor molecules synthesized in the hsp90-depleted lysate showed the production of polypeptides differing from the expected chromatographic pattern on DEAE-cellulose. Upon addition of purified hsp90 to the hsp90-depleted lysate, before translation, the 35S-labeled synthesized receptor fractionated on DEAE-cellulose as an intermediate peak between activated and nonactivated receptor forms. The data suggest that hsp90 alone may not be sufficient for the formation of the nonactivated steroid receptor complex.

Animals↗
PubMed1991

Autoantibodies against CD4 cells are associated with CD4 helper defects in human immunodeficiency virus-infected patients.

To investigate whether autoantibodies against CD4-positive lymphocytes might induce helper dysfunction, autoantibody formation and T-cell function was examined simultaneously in 61 hemophilia patients. Twenty patients were human immunodeficiency virus (HIV)-negative, 26 HIV-positive stage CDC II or III, and 15 were HIV-positive stage CDC IV. T lymphocytes, CD4-positive, or CD8-positive T subsets were cocultured with B lymphocytes and pokeweed mitogen (PWM) for 6 days and Ig-secreting cells were assessed in a reverse hemolytic plaque assay. The presence of IgM, IgG, C3d, or gp120 on the surface of T cells or T subsets was analyzed by flow cytometry. Autoantibodies against CD4-positive T cells were not detected in controls or HIV-negative patients, but were common in HIV-positive patients (20 of 41 patients). In patients with autoantibodies we found an increased incidence of CD4 helper defects (P less than .0001 in CDC II or III patients; P less than .02 in CDC IV patients). 12 of 13 patients with IgM autoantibodies and 4 of 4 with IgG autoantibodies showed CD4 helper defects. Complement fixation had no relevance. Autoantibody formation against CD4 cells was not due to increased in vivo B-cell stimulation (spontaneous plaque formation: 611 +/- 204 PFC/10(6) B cells in autoantibody-negative patients v 650 +/- 202 PFC/10(6) B cells in autoantibody-positive patients; not significant). Thus, our results suggest that autoantibody formation is not caused by a general state of in vivo B-cell activation. Rather, the production of autoantibodies appears to coincide with defects in B-cell proliferation or differentiation, as shown by reduced mitogen-stimulated B-cell responses in CDC II and III patients (P less than .05). Autoantibodies against CD4 cells appear to be involved in the pathogenesis of CD4 helper defects of HIV-infected patients.

Antigens, CD↗
PubMed1991

Improving CD4+ lymphocyte counts in HIV-infected hemophilia patients. A favorable prognostic indicator?

CD4+ lymphocyte counts of 91 HIV+ hemophilia patients were monitored for a mean of 4 years (range: 15-69 months). CD4+ lymphocytes decreased in 55 but increased in 36 patients over time. The CD4+ cell increases were persistent in 5 patients, whereas they fluctuated in 31. Of the 36 patients with increasing CD4+ counts 3 developed AIDS and 1 LAS. The other 32 patients were clinically asymptomatic (CDC II), but had immunological abnormalities, such as increased serum neopterin (N = 18) and impaired in vitro T cell responses to pooled allogenic stimulator cells (N = 15) or mitogens (N = 18). In contrast, of the 55 patients whose CD4+ cells decreased, 24 developed AIDS and 5 ARC (P less than 0.0005). Only 2 of these 55 patients had normal mitogen stimulation in vitro and normal serum neopterin levels.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Diagnosis of "excited skin syndrome" from blood. An aid in plastic surgery].

The relevance of hyperergic responsiveness in type IV allergies (synonyms: angry back, excited skin syndrome) for the postoperative course of wound healing and the tolerance against grafts, especially against synthetic materials, is discussed. The common non-specific prophylactic administration of drugs must be re-evaluated. The possibility of improving the diagnosis of the phenomenon by determining T-lymphocyte subpopulations, a method that is not well known, is discussed.

Adult↗
PubMed1991

[Hepatitis C virus antibodies in patients following blood transfusion and kidney transplantation].

The prevalence of anti-HCV in patients after kidney transplantation was tested by HCV-Antibody-ELISA (Ortho Diagnostics). In addition, reactive samples were tested by HCV-EIA (Abbott Laboratories), neutralization, anti-HBc (Corzyme, Abbott) and by HBs-Ag (Auszyme, Abbott). 27 of 271 patients (10%) were anti-HCV positive. Receiving more than one kidney graft (TPL) or the transfusion of more than four blood units (BU) increases the risk of HCV infection four times (OR: 4.1; p less than 0.01) or 2.5 times (OR: 2.5; p less than 0.05), respectively, compared with one TPL or less than 4 BU. Receiving more than one kidney graft and transfusion of more than four BU raises the risk of HCV infection 6.8 times. 52% of anti-HCV positive patients were anti-HBc positive, 48% were anti-HBc negative as well as HBs-Ag negative.

Blood Transfusion↗
PubMed1990

Xenobiotic-inducible expression of murine glutathione S-transferase Ya subunit gene is controlled by an electrophile-responsive element.

Glutathione S-transferase (GST) Ya subunit gene expression is induced in mammalian tissues by two types of chemical agents: (i) planar aromatic compounds (e.g., 3-methylcholanthrene, beta-naphthoflavone, and 2,3,7,8-tetrachlorodibenzo-p- dioxin) and (ii) electrophiles (e.g., trans-4-phenyl-3-buten-2-one and dimethyl fumarate) or compounds easily oxidized to electrophiles (e.g., tert-butylhydroquinone). To study the mechanism of this induction, we have introduced deletions in the 5' flanking region of a mouse GST Ya subunit gene, fused it to the coding sequence for chloramphenicol acetyltransferase (CAT) activity, and transfected the Ya-CAT genes for expression into hepatoma cells. We show that a single cis-regulatory element, between nucleotides -754 and -713 from the start of transcription, is responsible for the induction by both planar aromatic and electrophilic compounds. Using murine hepatoma cell mutants defective in either the Ah-encoded aryl hydrocarbon receptor (BPrc1 mutant) or in cytochrome P1-450 gene (c1 mutant), we show that induction by planar aromatic but not by electrophilic inducers requires a functional Ah receptor and cytochrome P1-450 activity. From this it is concluded that Ya gene activation by planar aromatic compounds involves metabolism of these inducers by the phase I xenobiotic-metabolizing cytochrome P1-450 system into electrophilic compounds, which is consistent with a recently proposed model [Prochaska, H. J. & Talalay, P. (1988) Cancer Res. 48, 4776-4782]. Therefore, the regulatory sequence of the Ya gene should be considered an electrophile-responsive element (EpRE) activated exclusively by inducers containing an electrophilic center. An EpRE-containing 41-bp oligonucleotide ligated at the -187 site of the Ya gene promoter confers upon it an increase in basal activity and xenobiotic inducibility. The basal activity augments with the number of EpRE copies. DNase I protection patterns show the protection of the EpRE domain by a nuclear factor(s) that becomes more abundant upon exposure of Hepa 1c1c7 cells to tert-butylhydroquinone.

Animals↗