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)

Interferon-alpha is an effective treatment for a subset of patients with AIDS-associated Kaposi's sarcoma. When given at high doses to patients who lack systemic signs, symptoms, and opportunistic infections associated with advanced HIV infection and who maintain some degree of cell-mediated immune function, tumor regression may be observed in a high proportion of patients. Although the addition of chemotherapy to IFN-alpha appears to confer no added benefits, the combination of IFN-alpha with zidovudine has induced high tumor response rates in preliminary studies, including responses in some patients considered unlikely to respond to IFN-alpha alone. IFN-alpha-induced tumor regression has also been associated with suppression of HIV, as measured by serum p24 antigen concentrations and peripheral blood virus cultures. Other biologic agents, including interferons beta and gamma, tumor necrosis factor, and IL-2, have also been tested, to a lesser extent, in patients with Kaposi's sarcoma. Although systemically administered IFN-beta and intralesional TNF injections have led to tumor regression in some cases, the role of these biologics has been incompletely defined. Additional studies of these agents in combination with nucleoside reverse transcriptase inhibitors such as zidovudine will be required to fully assess their role in the treatment of Kaposi's sarcoma and HIV infection. It can also be anticipated that newer biologic agents, which specifically inhibit the production or action of angiogenic factors believed to be involved in the genesis of Kaposi's sarcoma, will be studied in the near future.
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PMID:Interferon and other biologic agents for the treatment of Kaposi's sarcoma. 170 60

Interferon alpha was one of the first drugs tested for the treatment of patients with AIDS-related Kaposi's sarcoma based on its known antiviral properties and its abilities to modulate immune function and inhibit neoplastic cell proliferation. In vitro studies demonstrated defective production of interferon by blood cells of HIV-infected individuals and suppression of HIV replication by interferons alpha and beta. Interferons have also been shown to inhibit angiogenesis induced by tumour cells or by allogeneic lymphocytes in mice. The efficacy of recombinant interferon alpha for the treatment of AIDS-related Kaposi's sarcoma has been well documented with antitumour responses seen in approximately 30% of all patients treated in single agent efficacy trials with doses of at least 20 MU/m2. In several uncontrolled studies, response of Kaposi's sarcoma to treatment with interferon alpha was associated with longer survival and few opportunistic infections. Tumour response appears to be correlated with an absence of opportunistic infection and with CD4 cell numbers. Several studies using high interferon alpha doses have demonstrated decreases in serum HIV P24 core antigens which appear to be confined to patients whose tumours also regressed. The use of interferon alpha in HIV-infected patients with or without Kaposi's sarcoma have demonstrated in vivo anti-HIV activity. Studies have recently evaluated the tolerance and therapeutic potential of interferon alpha in combination with the reverse transcriptase inhibitor, zidovudine (azidothymidine AZT). Synergistic suppression of HIV replication in vitro has been demonstrated with the combination of interferon alpha and zidovudine. The description of HIV isolates with reduced sensitivity to zidovudine following prolonged treatment, and the finding that interferon alpha, but not zidovudine, prevents HIV expression in chronically infected cell lines, suggests that this combination might be useful in long-term treatment of patients with HIV infection.
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PMID:Interferon alpha in the treatment of AIDS-related Kaposi's sarcoma. 193 14

Therapy of AIDS comprises two aspects: (1) causative therapy, directed against HIV, and (2) symptomatic therapy of opportunistic infections and malignancies. The best results regarding antiretroviral therapy - both in vitro and in vivo - have been obtained, so far, with inhibitors of reverse transcriptase. We discuss the mechanism of action, the efficacy, and the side effects of AZT, a nucleoside analogue, and comment on combined therapies with acyclovir and immunomodulators. We report on the therapy of the most frequent opportunistic infection - i.e. Pneumocystis carinii pneumonia - with sulfamethoxazole/trimethoprim and pentamidine as well as the chemoprophylaxis of this disease. During the last few years, important progress has been made in the field of antiviral chemotherapy (HSV, CMV, VZV) and the therapy of gastrointestinal infections. Moreover, the therapy of Kaposi's sarcoma associated with AIDS and that of non-Hodgkin's lymphoma has been established by now.
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PMID:[AIDS therapy]. 220 64

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

Alteration of the p53 gene is the most frequent event reported in human cancer, and p53 mutations have been observed in various neoplasms, including certain forms of skin cancer. Therefore, we postulated that p53 may also be involved in Kaposi's sarcoma associated with AIDS (AIDS-KS). Expression of the p53 gene was examined in freshly isolated tumor biopsy specimens from 15 patients with AIDS-KS. p53 mRNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in both the AIDS-KS tumors and in normal skin control samples. p53 protein was detected in 4 of the 15 AIDS-KS specimens by immunohistochemical staining. Single-strand conformation polymorphism analysis PCR-products (PCR-SSCP) was used for detection of mutations of the p53 gene. One of the p53 positive AIDS-KS samples showed mobilized shifts in exon 6 suggestive of a mutation. Sequencing data showed the mutation to be located in codon 210. We examined other mechanisms that could stabilize p53 protein. SV40 large T antigen and adenovirus E1B protein were not found in the AIDS-KS specimens. MDM2, a p53-binding protein, was also detected in five of the AIDS-KS specimens, two of which also contained p53-positive cells. These observations suggest that the tumor suppressor gene p53 may be involved in the pathogenesis of AIDS-KS.
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PMID:Expression and mutation of the tumor suppressor gene p53 in AIDS-associated Kaposi's sarcoma. 965 Jul 11

The clinical response of AIDS-related Kaposi's sarcoma (KS) to highly active antiretroviral therapy (HAART), a combination of human immunodeficiency virus type 1 (HIV-1) protease and reverse transcriptase inhibitors, was studied in 11 patients, all but one with progressive KS. CD4+ cell counts, plasma HIV-1 RNA levels, and antibody titres to lytic ORF65 and latency-associated human herpes virus type 8 (HHV-8) proteins were determined in sequential samples. Six complete and three partial clinical responses were achieved in a median time of 6 and 3 months, respectively, and confirmed after a median time of 16 months on HAART. 2 patients showed disease progression. A consistent decrease in HIV-1 RNA levels, paralleled by an increase in CD4+ cell counts, was observed in all patients who showed complete or partial clinical response; HIV-1 RNA levels remained persistently high in the two patients who progressed, despite a change in HAART. HHV-8 antibody titres were generally higher in patients with mucosal/visceral involvement compared with patients with limited disease; a decrease in ORF65 antibody titre was significantly associated with a clinical response. These results indicate that HAART is effective for AIDS-related KS; the clinical response correlates with a decrease in plasma HIV-1 RNA levels, an increase in CD4+ lymphocytes, and a decrease in antibodies to ORF65 HHV-8 protein.
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PMID:Regression of AIDS-related Kaposi's sarcoma following antiretroviral therapy with protease inhibitors: biological correlates of clinical outcome. 1067 96

The purpose of the work was to assess the predictive value of biologic factors on the efficacy of highly active antiretroviral therapy alone or combined with chemotherapy on AIDS-associated Kaposi's sarcoma. Twenty-six AIDS-Kaposi's sarcoma patients who started therapy with protease inhibitors were investigated. No baseline chemotherapy was associated with less severe initial clinical status. Median follow-up was 652 d. The main outcome measures were as follows: best Kaposi's sarcoma clinical response; Kaposi's-sarcoma-associated herpesviral load in peripheral blood mononuclear cells using real-time quantitative polymerase chain reaction (non-detectable if less than 100 copies per microg); human immunodeficiency viral charge in plasma (non-detectable if less than 200 copies per ml); and CD4 lymphocyte count. Time to undetectable Kaposi's-sarcoma-associated herpesviral load, time to undetectable human immunodeficiency viral charge, and time to CD4 >or= 150 per microl were also recorded over time, from 2 mo measurements. Patients were staged according to the AIDS Clinical Trials Group-based tumor, immune, systemic staging system criteria. At baseline, Kaposi's sarcoma was progressive for 25 (96%) of the 26 enrolled patients. Complete or partial response to highly active antiretroviral therapy alone or combined with chemotherapy was achieved in 22 patients (85%). Median time to clinical response was estimated at 251 d. Clinical response was faster in patients without chemotherapy at baseline (p = 0.003) as well as in patients not previously treated with reverse transcriptase inhibitors (p = 0.0012). Using univariable analyses, predictive factors of clinical response were undetectable Kaposi's-sarcoma-associated herpesviremia (p = 0.013), undetectable human immunodeficiency viremia (p = 0.03), and relative variation of CD4 lymphocytes (p = 0.004). Using multivariable analysis, undetectable Kaposi's-sarcoma-associated herpesviremia (p = 0.009) and relative variation of CD4 (p = 0.005) were independently selected as having a predictive value for clinical response. Occurrence of nondetection of either Kaposi's-sarcoma-associated herpesvirus or human immunodeficiency virus was not associated with baseline CD4 value. Kaposi's-sarcoma-associated herpesvirus quantitative viral charge is an independent predictive factor of the efficacy of highly active antiretroviral therapy on AIDS-Kaposi's sarcoma. Our results support immune reconstitution as a mechanism of response of Kaposi's sarcoma to highly active antiretroviral therapy.
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PMID:Virologic and immunologic parameters that predict clinical response of AIDS-associated Kaposi's sarcoma to highly active antiretroviral therapy. 1167 23