Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of the study was to assess regression of Kaposi's sarcoma (KS) in AIDS patients in Argentina. Eighteen male AIDS patients with human immunodeficiency virus (HIV)-associated Kaposi's sarcoma at different clinical stages received KS specific treatment and/or anti-retroviral therapy. Triple anti-retroviral therapy was given to most of the patients with the exception of four who received zidovudine (ZDV) in combination with another nucleoside analogue but no protease inhibitors. Plasma viral load and CD4+ T lymphocyte number were measured in two blood samples (before and after treatment). Complete remission was found in all patients (five) at KS stage I, three out of eight patients at stage II but in none at stages III and IV. Two out of three patients at KS stage IV did not respond to treatments at all. Three patients at KS stages I and II showed complete remission of sarcoma with only anti-retroviral therapy suggesting that anti-retroviral therapy and non-KS specific chemotherapy can successfully control KS.
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PMID:Regression of AIDS-related Kaposi's sarcoma following combined antiretroviral treatment. 1114 54

Kaposi's sarcoma (KS) is an angioproliferative disease occurring in several clinical-epidemio-logic forms but all associated with infection by the human herpesvirus-8 (HHV-8). At least in early stages, KS is a reactive disease associated with a state of immune dysregulation characterized by CD8+ T-cell activation and production of Th1-type inflammatory cytokines (IC) that precedes lesion development. In fact, evidence indicates that IC can trigger lesion formation by inducing the activation of endothelial cells that leads to adhesion and tissue extravasation of lymphomonocytes, spindle cell formation, and angiogenesis, and HHV-8 reactivation that, in turn, leads to virus spread to all circulating cell types and virus dissemination into tissues. Due to virus escape mechanisms and deficient immune responses toward HHV-8, virus reactivation and spread are not controlled by the immune system but induce immune responses that may paradoxically exacerbate the reactive process. The virus is recruited into "activated" tissue sites where it finds an optimal environment for growth. In fact, viral load is very low in early lesions, whereas almost all spindle cells are infected in late-stage lesions. Although early KS is a reactive process of polyclonal nature that can regress, in time and in the presence of immunodeficiency, it can progress to a true sarcoma. This is likely due to the long-lasting expression of HHV-8 latency genes in spindle cells associated with the deregulated expression of oncogenes and oncosuppressor genes and, for AIDS-KS, with the effects of the HIV-1 Tat protein.
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PMID:Reactivation and role of HHV-8 in Kaposi's sarcoma initiation. 1143 May 95

Soft tissue sarcomas account for about 1% of all malignancies. The increase in incidence of soft tissue sarcomas during the recent decades may predominantly be attributed to AIDS-related Kaposi's sarcoma; when this tumor is excluded, conclusive evidence for an age-adjusted increase is lacking. Beside the well investigated role of the human immunodeficiency virus 1 (HIV-1) and the human herpesvirus 8 (HHV-8) in the tumorigenesis of AIDS-related Kaposi's sarcoma and several inherited disorders, considerable evidence support a relationship between occupational chemicals as vinyl chloride, phenoxyacetic acid herbicides, chlorphenols, dioxin, medicinal measures as Thorotrast exposure and therapeutic irradiation, and the development of soft tissue sarcoma. Hormones and chronic repair processes are further probably sarcoma-promoting factors. Considering the rarity of soft tissue sarcomas despite the vast portion that soft tissues comprise in the human body, additional knowledge on the tumorigenesis of soft tissue sarcomas might considerably contribute to the understanding of the etiologic pathways of malignant tumors in humans.
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PMID:Etiologic factors in soft tissue sarcomas. 1144 Dec 93

We are using avian leukosis-sarcoma virus (ALSV) vectors to generate mouse tumor models in transgenic mice expressing TVA, the receptor for subgroup A ALSV. Like other classical retroviruses, ALSV requires cell division to establish a provirus after infection of host cells. In contrast, lentiviral vectors are capable of integrating their viral DNA into the genomes of nondividing cells. With the intention of initiating tumorigenesis in resting, TVA-positive cells, we have developed a system for the preparation of a human immunodeficiency virus type 1 (HIV-1)-based lentiviral vector, pseudotyped with the envelope protein of ALSV subgroup A (EnvA). The HIV(ALSV-A) vector retains the requirement for TVA on the surface of target cells and can be produced at titers of 5 x 10(3) infectious units (IU)/ml. By inserting the central polypurine tract (cPPT) from the HIV-1 pol gene and removing the cytoplasmic tail of EnvA, the pseudotype can be produced at titers approaching 10(5) IU/ml and can be concentrated by ultracentrifugation to titers of 10(7) IU/ml. HIV(ALSV-A) also infects embryonic fibroblasts derived from transgenic mice in which TVA expression is driven by the beta-actin promoter. In addition, this lentivirus pseudotype efficiently infects these fibroblasts after cell cycle arrest, when they are resistant to infection by ALSV vectors. This system may be useful for introducing genes into somatic cells in adult TVA transgenic animals and allows evaluation of the effects of altered gene expression in differentiated cell types in vivo.
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PMID:Development of an avian leukosis-sarcoma virus subgroup A pseudotyped lentiviral vector. 1153 97

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

6-Hydroxypyrimidines substituted at positions 2 and 4 by hydrogen, methyl, amino, cyclopropylamino, dimethylamino, methylsulfanyl, or hydroxyl group afford by the reaction with diisopropyl 2-(chloroethoxy)methylphosphonate in the presence of NaH, Cs(2)CO(3), or DBU a mixture of N(1)- and O(6)-[2-(diisopropylphosphorylmethoxy)ethyl] isomers which were converted to the free phosphonic acids by treatment with bromotrimethylsilane followed by hydrolysis. Analogously, 2,4-diamino-6-hydroxypyrimidine gave on reaction with [(R)- and (S)-2-(diisopropylphosphorylmethoxy)propyl] tosylate, followed by deprotection, the enantiomeric 6-[2-(phosphonomethoxy)propoxy]pyrimidines. 2,4-Diamino-6-sulfanylpyrimidine gave, on treatment with diisopropyl 2-(chloroethoxy)methylphosphonate in the presence of NaH and subsequent deprotection, 2,4-diamino-6-[[2-(phosphonomethoxy)ethyl]sulfanyl]pyrimidine. 2-Amino-4-hydroxy-6-[2-(phosphonomethoxy)ethyl]pyrimidine was obtained from the appropriate 2-amino-4-chloropyrimidine derivative by alkaline hydrolysis and ester cleavage. Direct alkylation of 2-amino-4,6-dihydroxypyrimidine afforded a mixture of 2-amino-4,6-bis[2-(phosphonomethoxy)ethyl]- and 2-amino-1,4-bis[2-(phosphonomethoxy)ethyl]pyrimidine. None of the N(1)-[2-(phosphonomethoxy)ethyl] isomers exhibited any antiviral activity against DNA viruses or RNA viruses tested in vitro. On the contrary, the O(6)-isomers, namely the compounds derived from 2,4-diamino-, 2-amino-4-hydroxy-, or 2-amino-4-[2-(phosphonomethoxy)ethoxy]-6-hydroxypyrimidine, inhibited the replication of herpes viruses [herpes simplex type 1 (HSV-1) and type 2 (HSV-2), varicella-zoster virus (VZV), and cytomegalovirus (CMV)] and retroviruses [Moloney sarcoma virus (MSV) and human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2)], their activity being most pronounced against the latter. The antiviral activity was lower if the oxygen at the position 6 was replaced by a sulfur atom, as in 2,4-diamino-6-[2-(phosphonomethoxy)ethylsulfanyl]pyrimidine. In analogy to N(9)-[2-(phosphonomethoxy)propyl]-2,6-diaminopurine (PMPDAP), solely the (R)-2,4-diamino-6-[2-(phosphonomethoxy)propoxy]pyrimidine exerted antiviral activity, whereas its (S)-enantiomer was essentially inactive.
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PMID:6-[2-(Phosphonomethoxy)alkoxy]pyrimidines with antiviral activity. 1196 May 2

Kaposi s sarcoma (KS) is a angioformative lesion that classically occurs in elderly Eastern European and Mediterranean males but is also common in immunosuppressed individuals particularly human immunodeficiency virus (HIV)-infected patients. This study investigates the clinical and histopathological features of 47 patients with Kaposi s sarcoma from a teaching hospital in Sydney, Australia, in which 44 cases had adequate clinical follow-up information over a 10-year period. Most of the lesions were of late stage (37/47 cases; 79%), consisting of 11 cases of plaque stage KS and 26 cases of nodular stage KS with only 10 cases of early or patch stage KS. The majority of the HIV-positive cases (23/33; 70%) and all of the HIV-negative (14/14; 100%) cases had late stage lesions (p=0.020; X 2 -test). The histopathological features that were more common in the KS lesions of HIV-negative patients were lesional cell mitosis (p=0.0002), single cell necrosis (p=0.001), apoptosis (p=0.0001) and single cell anaplasia (p=0.0001). The KS lesions in HIV-positive patients tended to have dissecting blood vessels (14/33 cases; 42%) unlike those seen in HIV-negative patients (0/14 cases; 0%) (p=0.004). Most HIV-positive cases (30/33; 90%) were males (p=0.0068); and all these patients (33/33 cases; 100%) were <60 years old, in contrast to HIV-negative patients (1/11 cases; 9%) (p=0.0001). HIV status does not affect the occurrence of multiplicity of KS lesions. However, extracutaneous or visceral KS lesions were more likely to occur in HIV-positive patients (p=0.027). The number of cases of histologically proven KS cases has decreased markedly over the recent 5 year period of 1995-1999 (n=14), which was less than half of the number of the preceding 5 year period, 1990-1994 (n=33). In summary, there are distinct differences in the clinical and histopathological features of Kaposi s sarcoma lesions in HIV-positive and HIV-negative patients. Despite the recent discovery of the HHV8 virus as the initiating and promoting factor of most of the KS lesions, these differences indicated that there might be different mechanisms that occur in HIV-positive and HIV-negative patients in the development of this lesion.
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PMID:Kaposi's sarcoma: clinico-pathological analysis of human immunodeficiency virus (HIV) and non-HIV associated cases. 1199 60

Walleye dermal sarcoma virus (WDSV) is a piscine retrovirus that replicates naturally in fish at temperatures near 4 degrees C. The reverse transcriptase (RT) protein from virus particles isolated from walleye tumours was purified and biochemically characterized. Like the RT of the distantly related murine leukaemia virus, WDSV RT sediments as a monomer in the absence of template. It exhibits a K(m) of 22 microM for TTP in an assay with poly(rA) as a template and oligo(dT) as a primer. The enzyme is rapidly inactivated at temperatures greater than 15 degrees C. The ratio of RT activity at 15 degrees C to that at 4 degrees C is similar for WDSV and recombinant human immunodeficiency virus type 1, suggesting that, at least with this template, the fish enzyme is not specially adapted to function more efficiently in the cold.
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PMID:Walleye dermal sarcoma virus reverse transcriptase is temperature sensitive. 1202 51

A novel class of acyclic nucleoside phosphonates has been discovered in which the base consists of a pyrimidine preferably containing an amino group at C-2 and C-4 and a 2-(phosphonomethoxy)ethoxy (PMEO) or a 2-(phosphonomethoxy)propoxy (PMPO) group at C-6. The 6-PMEO 2,4-diaminopyrimidine (compound 1) and 6-PMPO 2,4-diaminopyrimidine (compound 11) derivatives showed potent activity against human immunodeficiency virus (HIV) in the laboratory (i.e., CEM and MT-4 cells) and in primary (i.e., peripheral blood lymphocyte and monocyte/macrophage) cell cultures and pronounced activity against Moloney murine sarcoma virus in newborn NMRI mice. Their in vitro and in vivo antiretroviral activity was comparable to that of reference compounds 9-[(2-phosphonomethoxy)ethyl]adenine (adefovir) and (R)-9-[(2-phosphonomethoxy)-propyl]adenine (tenofovir), and the enantiospecificity of (R)- and (S)-PMPO pyrimidine derivatives as regards their antiretroviral activity was identical to that of the classical (R)- and (S)-9-(2-phosphonomethoxy)propyl purine derivatives. The prototype PMEO and PMPO pyrimidine analogues were relatively nontoxic in cell culture and did not markedly interfere with host cell macromolecular (i.e., DNA, RNA, or protein) synthesis. Compounds 1 and 11 should be considered attractive novel pyrimidine nucleotide phosphonate analogues to be further pursued for their potential as antiretroviral agents in the clinical setting.
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PMID:Antiretrovirus activity of a novel class of acyclic pyrimidine nucleoside phosphonates. 1206 73

Retroviral integrase (IN) is the viral enzyme responsible for the integration of viral DNA into host cellular DNA. In vitro, recombinant IN protein is able to catalyze the 3'-processing, strand transfer and disintegration activities. In order to analyze the importance of specific residues of ALSV (Avian leukemia and sarcoma viruses) IN protein, we introduced 31 amino acid substitutions either in residues previously shown by others to be involved in IN oligomerization or in selected conserved and non-conserved residues through the IN sequence. We tested, in vitro, the three catalytic activities of these mutants as well as their capacity to bind DNA. We found that (i) 88% of the substitutions occurring on well-conserved residues have an effect on IN activities (ii) two mutants (S85T in the central catalytic domain and N197C in the C-terminal domain) present a reduced efficiency of DNA binding compared to the wild type protein. Moreover, all mutations made on the dimer interface of C-terminal domain present reduced activities, suggesting an important role of this part of the protein. Finally, for some mutations, we observed differences between the ALSV and HIV (Human immunodeficiency virus) IN corresponding residues.
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PMID:Analysis of conserved and non-conserved amino acids critical for ALSV (Avian leukemia and sarcoma viruses) integrase functions in vitro. 1220 15


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