Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phosphonoformate (PFA; a pyrophosphate analogue) is an effective inhibitor of the reverse transcriptase enzyme in many animal retroviruses. In vitro studies have shown that PFA is also an effective inhibitor of HIV (HTLV III/LAV) at doses readily attainable in vitro. A pilot study was therefore performed with a 3-week intravenous infusion of PFA in 11 patients with AIDS and AIDS-related complex (ARC). Viral isolations were performed before and at regular intervals up to 3 months post-infusion on treated patients, as well as on four untreated control patients. Virus isolation was negative after therapy in eight patients, six of whom were negative throughout the follow-up period. Virus was isolated on 70% of attempts from the four control subjects and on 20% of attempts from treated subjects. Three patients showed an improvement in delayed hypersensitivity responses. No obvious improvement was seen in patients' OKT4 positive lymphocyte counts. Treatment was not limited by side-effects with the exception of one patient who developed an axillary vein thrombosis within 4 days of treatment via a subclavian line. Treatment was therefore discontinued following administration of only one dose and the patient was excluded from further study. A further patient had reversible renal dysfunction. Other side-effects were minor, consisting of headache or thrombophlebitis at the site of infusion. These results suggest that a further trial with PFA administered over a longer period and with a longer follow-up period in AIDS and ARC patients may be warranted, particularly if an oral preparation becomes available.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Phosphonoformate (foscarnet): a pilot study in AIDS and AIDS related complex. 296 89

It has been recently established that AIDS is a virus infectious disease. HTLV-I essentially makes T4 lymphocytes malignant and induces their abnormal proliferation. However, on the way, when HTLV-I induces a decrease in the function of T4 lymphocytes, the symptoms of ARC or AIDS take place on occasion. HTLV-III/LAV possesses a central function to destroy T4 lymphocytes, but, when this function is blocked, it increases T4 lymphocyte proliferation. Accordingly, the concept of carriers of the AIDS virus and patients with AIDS-related complex or AIDS has been clarified. Simultaneously, it has been discovered that a multiplicity of amino acids exists on the envelope of isolated AIDS viruses, resulting in a variety of viral envelope antigenicities. This may support the presence of antigenic modulation, which might make the development of a vaccine more difficult. Therapy has been approached from the following points of view; blockers of reverse transcriptase, drugs for destroying the virus itself through the viral envelope, vaccination, replacement of patient's T4 lymphocytes with healthy bone marrow, and use of immunopotentiators.
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PMID:[AIDS--a further development]. 301 Aug 82

The possibility of using oligodeoxynucleotides complementary to viral RNA or proviral DNA to inhibit the replication of human T-cell lymphotropic virus type III (HTLV-III) [the etiological agent of acquired immunodeficiency syndrome (AIDS)] in cultured human cells was addressed by studying the association of 32P-labeled oligodeoxynucleotides with mammalian cellular components. The results indicated that exogenous oligodeoxynucleotides at 20 microM became associated with the membrane/cytosol fractions of the cell in amounts approximating 1.5 microM. Oligodeoxynucleotides complementary to a region close to the tRNALys primer binding site on HTLV-III RNA and others complementary to HTLV-III mRNA donor or acceptor splice sites inhibited viral replication (assayed as reverse transcriptase) and gene expression (assayed as virus-encoded proteins p15 and p24) by as much as 95%. Use of control (random) oligodeoxynucleotides suggests that the antiviral effects were specific. Although these results pertain to HTLV-III-infected cells in tissue culture, rather than to AIDS patients, they nevertheless point to a therapeutic potential of the complementary oligodeoxynucleotide ("hybridization competition" or "hybridon") approach in the treatment of patients with AIDS and AIDS-related complex.
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PMID:Inhibition of replication and expression of human T-cell lymphotropic virus type III in cultured cells by exogenous synthetic oligonucleotides complementary to viral RNA. 301 55

The glycosylation inhibitors 2-deoxy-D-glucose (2-dGlc) and, to a lesser extent, beta-hydroxynorvaline blocked the formation of syncytia in HIV (LAV/HTLV-III)-infected cells. Using monospecific polyclonal antibodies against recombinant envelope proteins gp110 and gp41 or monoclonal antibodies against env gp110, we could demonstrate a marked reduction in the immunoreactivity of these antigens in HIV-infected cells exposed to the glycosylation inhibitors. There was concomitant accumulation of core proteins p15 and p24, as shown by a solid phase radio-immunoassay, and a decreased oligosaccharide synthesis of env proteins, as monitored by the incorporation of [6-3H]GlcNAc. The reverse transcriptase was not affected by the compounds. Glycosylation inhibitors may be considered for the chemotherapy of AIDS or AIDS-related complex, or chemoprophylaxis of HIV-positive individuals.
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PMID:Glycosylation inhibitors block the expression of LAV/HTLV-III (HIV) glycoproteins. 309 81

The genome of the HTLV-III/LAV retrovirus, the etiologic agent of the acquired immunodeficiency syndrome (AIDS), encodes the viral structural proteins (envelope and core proteins), the reverse transcriptase, a transactivation protein (tat-III), as well as two other proteins (3'orf, sor) of unknown function. We studied the prevalence of natural antibodies against envelope, gag, 3'orf, sor, and tat-III in the sera of HTLV-III infected individuals in an attempt to correlate clinical status with seropositivity to specific HTLV-III antigens. We selected 101 sera; 16 were obtained from normal donors with no known risk factors, and 85 were from patients with full-fledged AIDS (28 cases), AIDS-related complex (ARC, 22 cases), and healthy people at risk (homosexuals, intravenous [IV] drug users, relatives of AIDS patients; 35 cases). Seropositivity for antibodies against the envelope (gp41) and gag antigens (p15, p24) was determined by Western blot using disrupted HTLV-III virions. Of the 101 sera, all 16 from nonrisk donors and 3/35 from healthy at-risk donors were negative for antibodies against either the gp41 or p15 and p24. The remaining 82 sera were seropositive for either the gp41 and/or the p15 and p24. All sera were then tested against the three known HTLV-III antigens (3'orf, sor, and tat-III) that have been synthesized in bacteria. Our data indicate that all the HTLV-III antigens tested are immunogenic in vivo. No significant difference in antibody prevalence to gp41 (close to 100%) and to the 3'orf, sor, and tat-III proteins (approximately 50%) was observed with regard to stage of the disease. In contrast, the prevalence of antibodies against the core antigens decreased from approximately 100% in infected people with no clinical signs of disease to 50% in ARC and AIDS patients. The percentage of patients seropositive for all five antigens tested was increased in the AIDS group. These results indicate that the greatest antibody prevalence was obtained using viral envelope antigen and further suggest that screening with the newly identified 3'orf, sor, and tat-III proteins as antigens would confer no further diagnostic advantage. The pattern of natural antibodies observed during disease progression did not suggest any pathogenetic mechanism.
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PMID:Spectrum of natural antibodies against five HTLV-III antigens in infected individuals: correlation of antibody prevalence with clinical status. 346 97

Suramin sodium is a reverse transcriptase inhibitor with in vitro activity against the human immunodeficiency virus (HIV), the causative agent of acquired immunodeficiency syndrome (AIDS). Ninety-eight patients with AIDS manifest as opportunistic infections (n = 38), AIDS with Kaposi's sarcoma (n = 38), AIDS-related complex (n = 20), or AIDS-associated non-Hodgkin's lymphoma (NHL) (n = 2) were treated with suramin sodium at 0.5, 1.0, or 1.5 g/wk for six weeks followed by maintenance therapy with 0.5 or 1.0 g/wk. Of 72 patients who were HIV culture positive before therapy and were assessable for subsequent HIV culture 40% became culture negative during treatment, with no apparent correlation between virus recovery and serum suramin concentration. No immunologic improvement was noted. One complete clinical remission was noted in a patient with Kaposi's sarcoma and stage IV NHL. Seven minor clinical responses were also noted. Toxic reactions were generally reversible, and included fever (78%), rash (48%), malaise (43%), nausea (34%), neurologic symptoms (33%), and vomiting (20%). Suramin-induced neutropenia was noted in 26%, thrombocytopenia in 12%, a serum creatinine level of 180 mumol/L or higher (greater than or equal to 2.1 mg/dL) in 12%, liver dysfunction in 14%, and clinical and/or laboratory evidence of adrenal insufficiency in 23%. Sixteen patients died while receiving suramin or within three weeks of discontinuation of drug therapy due to infection (n = 6), hepatic failure (n = 3), pulmonary Kaposi's sarcoma (n = 2), AIDS encephalitis (n = 2), AIDS-associated NHL (n = 1), iatrogenic hemo-pneumothorax (n = 1), or pulmonary disease of uncertain etiology. Suramin as currently administered cannot be recommended as effective therapy for AIDS.
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PMID:Suramin therapy in AIDS and related disorders. Report of the US Suramin Working Group. 365 Mar 39

LAV/HTLV-III has been closely linked to the acquired immunodeficiency syndrome (AIDS). We have studied and correlated the prevalence of AIDS-associated retrovirus and retroviral antibodies in several groups of male homosexuals from Greenwich Village. Retrovirus was detected in cultured peripheral blood lymphocytes by testing for reverse transcriptase (RT) and confirmed by establishment of virus-producer cell lines, and electron microscopy. Seventy-six percent of patients with AIDS, 93% with AIDS-related complex (ARC), 69% with generalized lymphadenopathy (LAS), and 35% of asymptomatic homosexuals were positive for virus in the RT assay. Transmission of the virus from RT-positive lymphocytes into the CEM cell line was successful in 10 of 11 randomly chosen cases. No virus isolates were obtained from lymphocytes of 8 heterosexual individuals. Serum antibodies against AIDS-associated virus were detected by indirect immunofluorescence assay and confirmed by Western blotting, using an LAV/HTLV-III-producer cell line, LAV-N1, which we established. LAV/N1 virus was purified by ultracentrifugation through sucrose gradient and the pattern of its proteins was determined by SDS-gel electrophoresis and Western blotting using sera from an AIDS patient. The major polypeptides of LAV/HTLV-III (19, 25-27, 32, 42 and 54 kilodalton) were present. These proteins did not react in Western blots with sera positive for Adult T cell leukemia virus (ATLV). thus, LAV-N1 and ATLV were not antigenically related. In our assay for LAV/HTLV-III antibodies, 18 (100%) of patients with AIDS, 13 (100%) of patients with ARC, 24 (69%) of 35 patients with LAS and 9 (39%) of 23 asymptomatic homosexuals were sero-positive. Heterosexual controls were negative. All IF-positive sera tested by Western blot contained antibodies against specific viral proteins. High titers (greater than or equal to 1:1280) of serum antibodies against LAV/HTLV-III virus were detected in 71% of AIDS patients, 62% with ARC, 38% LAS and 13% among asymptomatic homosexuals. Our data show that the presence of LAV/HTLV-III antibodies correlates with the presence of infectious virus. Antibody titers may also correlate with progression toward AIDS.
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PMID:Prevalence of AIDS-associated retrovirus and antibodies among male homosexuals at risk for AIDS in Greenwich Village. 608 26

Whole-saliva samples were collected from 45 asymptomatic carriers, 18 patients with AIDS-related complex (ARC) or AIDS, and 76 medical students by simple spitting with no stimulation and tested by an ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for anti-HIV-1 IgG using recombinant reverse transcriptase as antigen and beta-D-galactosidase as label. With as little as 1 microliter of whole saliva, the lowest signals among the 45 asymptomatic carriers, 8 patients with ARC, and 10 patients with AIDS were 38-, 78-, and 3-fold, respectively, higher than the highest signal among the medical students. When the volume of whole saliva for test was increased up to 100 microliters, no significant effect was observed on signals for seropositive cases and signals for the medical students increased only very slightly. Therefore, whole-saliva samples containing extremely low levels of anti-HIV-1 IgG, even 2,000-fold lower than the lowest level among the 45 asymptomatic carriers tested, were considered to be discriminated from those of seronegative individuals. Thus, the sensitivity and specificity were expected to be both 100% with whole saliva even for a larger number of samples, although the number of samples tested was limited.
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PMID:Diagnosis of HIV-1 infection with whole saliva by detection of antibody IgG to HIV-1 with ultrasensitive enzyme immunoassay using recombinant reverse transcriptase as antigen. 764 83

Since the discovery of the acquired immunodeficiency syndrome (AIDS) in 1981, considerable progress has been made in the development of agents with anti-HIV activity. Zidovudine was one of the first 2'-3'-dideoxynucleosides to cause inhibition of human immunodeficiency virus (HIV) replication in vitro, by inhibiting the viral reverse transcriptase. Early trials showed that zidovudine results in clinical and immunological improvements and prolonged life in patients with AIDS or AIDS-related complex. However, haematological toxicity is the main drawback associated with zidovudine therapy. The initial recommended dose of zidovudine was 1500 mg per day, but recent studies have shown that dosages as low as 300 mg per day could be just as effective, without the severe haematological toxicity. Because zidovudine readily crosses the blood-brain barrier, it is used for the treatment of neurological diseases associated with HIV disease with some success. However, Kaposi's sarcoma does not respond to therapy with the drug. Apart from haematological toxicity, patients on long-term therapy with zidovudine may also develop resistance. Zidovudine use has also been associated with improvements in neurodevelopmental and growth velocity in HIV-infected children. The use of zidovudine as a prophylaxis has also been suggested, but the value of this is questionable. The combination of zidovudine with other agents, such as acyclovir and interferon, has a synergistic effect on the anti-HIV activity, with reduced drug toxicity. Other 2',3'-dideoxynucleoside analogues, such as dideoxycytidine (ddC) and dideoxyinosine (ddI) are effective anti-HIV agents and their use is also associated with both clinical and immunological improvements.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical pharmacology of zidovudine and other 2',3'-dideoxynucleoside analogues. 768 14

2',3'-didehydro-3'-deoxythymidine (d4T) is a pyrimidine analogue and inhibitor of reverse transcriptase with potent in vitro activity against human immunodeficiency virus (HIV). A phase I trial of d4T was conducted in 41 HIV-infected patients, 12 with AIDS and 29 with AIDS-related complex (ARC). Thirty-six patients were evaluatable. The maximum tolerated dose was 2 mg/kg/day. The dose-limiting toxicity was sensory peripheral neuropathy, which occurred in 20 patients (55%). Four patients (11%) developed hepatotoxicity. Five (14%) developed anemia requiring a transfusion but not discontinuation of drug. The mean +/- SE plasma elimination half-life at all dose levels was 1.2 +/- 0.09 h. Increased or stable absolute CD4 counts were seen in most patients. The majority of patients with detectable serum p24 antigen levels had a persistent decrease by 6 months. d4T is a promising drug for patients with AIDS or ARC. This clinical trial is continuing to determine the minimal effective dose.
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PMID:2',3'-didehydro-3'-deoxythymidine (d4T) in patients with AIDS or AIDS-related complex: a phase I trial. 809 63


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