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)

One of the hallmarks of human immunodeficiency virus type 1 (HIV-1) infection is the decline in CD4+ T lymphocytes which precedes the progression from an asymptomatic state to AIDS. Apoptosis (programmed cell death) is one of the mechanisms proposed to mediate this depletion. Infectious and inactivated preparations of HIV-1LAI were compared for their potential to induce apoptosis. Analysis with fluorescence-activated cell sorting using the DNA intercalative compound propidium iodide demonstrated that apoptosis occurred only with infectious HIV-1, implying that cell surface binding and signalling by the virus alone were insufficient to trigger apoptosis. Apoptosis was further confirmed by the presence of characteristic digestion of host cell DNA and morphologically by nuclear condensation observed by transmission electron microscopy. HIV infection of CD4+ T cell lines generated an accumulation of the cells in G2/M phase of the cell cycle and cells undergoing apoptosis appeared to originate from the pool of cells in the G1 phase. Inhibitors of HIV replication were used to identify the point in the virus replicative cycle at which apoptosis is induced. The reverse transcriptase inhibitor, ddI, or the HIV protease inhibitor, RO31-8959 (Saquinavir), were added either 2 h before or 6 h after HIV inoculation. Only ddI inhibited HIV-induced apoptosis when added before inoculation; however, neither treatment was effective in preventing HIV-induced apoptosis when applied 6 h after inoculation. These data indicate that apoptosis requires a single round of reverse transcription and the expression of virion proteins, but not the maturation of progeny virions. Two agents which compete with HIV for binding to CD4+ T cells, dextran sulphate and the anti-CD4 MAb Leu3a, were effective at preventing apoptosis when added 6 h after infection, implying that a subsequent gp120-CD4 interaction at the surface of an infected cell was required to complete the apoptotic process.
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PMID:Productive infection and subsequent interaction of CD4-gp120 at the cellular membrane is required for HIV-induced apoptosis of CD4+ T cells. 789 56

Monotherapy with (-)2',3'-dideoxy-3'-thiacytidine (3TC) leads to the appearance of a drug-resistant variant of human immunodeficiency virus-type 1 (HIV-1) with the methionine-184 --> valine (M184V) substitution in the reverse transcriptase (RT). Despite resulting drug resistance, treatment for more than 48 weeks is associated with a lower plasma viral burden than that at baseline. Studies to investigate this apparent contradiction revealed the following. (i) Titers of HIV-neutralizing antibodies remained stable in 3TC-treated individuals in contrast to rapid declines in those treated with azidothymidine (AZT). (ii) Unlike wild-type HIV, growth of M184V HIV in cell culture in the presence of d4T, AZT, Nevirapine, Delavirdine, or Saquinavir did not select for variants displaying drug resistance. (iii) There was an increase in fidelity of nucleotide insertion by the M184V mutant compared with wild-type enzyme.
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PMID:Enhanced fidelity of 3TC-selected mutant HIV-1 reverse transcriptase. 899 51

We carried out a four-year prospective study in the rehabilitation and traumatology center of the Hospital La Paz, where a total of 5260 patients were included. The objective of the study was to know the main risk factors that could influence the development of an infection of surgical wound, and get a predictive equation of infection of surgical wound in our patients. We utilized logistic regression for it, following the patient by means of active epidemiological surveillance; the main risk factors found were: immunodeficiency (OR = 8.3) wrong scaring (OR = 14.4), more than one intervention (OR = 3.5), type of surgical intervention (OR = 4.8) and incorrect use of prophylaxis (OR = 6.3). We considered that this knowledge could permit us to diminish the incidence of infections, specially if there is some of these factors, like the antimicrobial prophylaxis, that could be easily modified. Finally, upon applying to our patients the gotten equation, we get a ROC curve with 85% of the area under it, and if we take the point of cut of greater sensibility and specificity in this situation of very low prevalence of illness, it determines we could use it better in order to mark patients that don't suffer infection (high negative predictive value), making this possible to improve the efficacy of our work.
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PMID:Four year study of the risk factors of surgical wound infection in 5260 traumatological patients. 870 Mar 44

The development of resistance mutations and human immunodeficiency virus (HIV) RNA levels were compared in lymph nodes and plasma of patients receiving antiretroviral therapy. Ten HIV-positive patients receiving high-dose saquinavir monotherapy (3600 or 7200 mg/day) underwent 14 lymph node biopsies before and during therapy. HIV RNA levels and appearance of resistance mutations to saquinavir were determined in simultaneous lymph node and plasma samples. HIV RNA levels were found to be consistently higher (mean, 3.16 log RNA copies; SD, 1.04; range, 2.23-5.59) in lymph nodes than in simultaneous plasma samples. Saquinavir therapy resulted in a reduction in HIV RNA levels in both plasma and lymph nodes. The presence or absence of a resistance mutation to saquinavir at codons 48 or 90 of the HIV-1 protease gene was identical in 13 of 14 biopsies, suggesting that resistance mutations to saquinavir appear within close temporal proximity in lymph nodes and plasma.
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PMID:Lymph node human immunodeficiency virus RNA levels and resistance mutations in patients receiving high-dose saquinavir. 946 42

The pharmacology, pharmacokinetics, efficacy, adverse effects, drug interactions, and dosage and administration of protease inhibitors are reviewed. Protease inhibitors are a novel class of drugs used for the treatment of human immunodeficiency virus (HIV) infection. Saquinavir, ritonavir, indinavir, and nelfinavir have been approved in the United States; several other agents are under development. Protease inhibitors selectively block HIV protease, an enzyme involved in the later stages of HIV replication. Various pharmacokinetic differences exist among these agents, including differences in bioavailability, protein binding, and drug interactions. The drugs undergo extensive hepatic metabolism; dosage adjustments should be considered for patients with hepatic dysfunction. Clinical trials have shown protease inhibitors to be effective in reducing HIV RNA levels and increasing CD4+ lymphocyte counts. When protease inhibitors are used in combination with other antiretroviral agents, an additional beneficial effect on these markers occurs. Adverse effects of saquinavir and nelfinavir include mild gastrointestinal disturbances such as diarrhea. Ritonavir is less well tolerated because of gastrointestinal disturbances and circumoral and peripheral paresthesia. Indinavir has been associated with nephrolithiasis and asymptomatic hyperbilirubinemia. The development of resistance to protease inhibitors may be related to suboptimal dosages, noncompliance, or partial compliance. Protease inhibitors are potent and highly selective agents that block a critical step in HIV replication. They are effective and relatively well tolerated, but they are expensive, have extensive drug interaction profiles, and require careful compliance with the prescribed regimen.
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PMID:Protease inhibitors for the treatment of human immunodeficiency virus infection. 949 54

Protease inhibitors are an important new class of agents for the treatment of human immunodeficiency virus (HIV) infection. The purpose of our trial was to determine the feasibility of combining the protease inhibitor saquinavir with a 96-hour continuous intravenous infusion of cyclophosphamide (800 mg/M2), doxorubicin (50 mg/M2, and etoposide (240 mg/M2) (CDE) plus filgrastim in patients with non-Hodgkin's lymphoma associated with HIV infection. The effect of saquinavir on CDE-induced myelosuppression, CD4 lymphopenia, and non-hematologic toxicity was also sought. Twelve patients with HIV-related lymphoma received CDE every 28 or more days. All patients received saquinavir (600mg PO TID), filgrastim and Pneumocystis carinii and fungal prophylaxis. Patients also received either stavudine (n = 2) or both stavudine and didanosine (n = 10). Toxicity was analyzed using the NCI Common Toxicity Criteria for each cycle and the data were compared with the data from our prior study of CDE plus didanosine. An interim analysis was performed after accrual of the first 12 patients in order to assess toxicity. Severe (grade 3 or 4) mucositis occurred in eight of 12 patients (67%) treated with CDE plus saquinavir compared with three of 25 patients (12%) in our prior study treated with CDE without saquinavir (P < 0.001). In logistic regression analysis, saquinavir use was the only factor associated with a significantly greater risk of severe mucositis (relative risk 7.9; P = 0.03). Saquinavir use was not associated with a significant difference in the incidence of febrile neutropenia, prolonged neutropenia, chemotherapy dose reduction, or in the degree of myelosuppression. The decrease in CD4 lymphocytes for patients treated with saquinavir (absolute decrease of 23/microL, or a 26% decrease from baseline) was significantly less than for patients treated without saquinavir in the prior study (absolute decrease of 91/microL, or 42% decrease from baseline; P = 0.05). Four of 10 patients (40%) treated with saquinavir had an increase in CD4 lymphocytes of > or = 10/microL compared with none of 25 patients (0%) treated without saquinavir (P < 0.001). Combination of the protease inhibitor saquinavir with infusional CDE in patients with HIV-associated lymphoma was associated with a significant increase in the incidence of severe mucositis. This finding suggests that saquinavir may alter the metabolism of one of more of the cytotoxic agents in the CDE regimen, and underscores the need for careful investigation regarding the use of the protease inhibitors in patients receiving chemotherapy.
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PMID:Saquinavir enhances the mucosal toxicity of infusional cyclophosphamide, doxorubicin, and etoposide in patients with HIV-associated non-Hodgkin's lymphoma. 964 31

The activity of three human immunodeficiency virus (HIV) protease inhibitors was investigated in human primary monocytes/macrophages (M/M) chronically infected by HIV-1. Saquinavir, KNI-272, and ritonavir inhibited the replication of HIV-1 in vitro, with EC50s of approximately 0.5-3.3 microM. However, only partial inhibition was achievable, even at the highest concentrations tested. Also, the activity of these drugs in chronically infected M/M was approximately 7- to 26-fold lower than in acutely infected M/M and approximately 2- to 10-fold lower than in chronically infected H9 lymphocytes. When protease inhibitors were removed from cultures of chronically infected M/M, production of virus rapidly returned to the levels found in untreated M/M. Therefore, relatively high concentrations of protease inhibitors are required to suppress HIV-1 production in chronically infected macrophages, and such cells may be a vulnerable point for the escape of virus in patients taking these drugs.
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PMID:Relative potency of protease inhibitors in monocytes/macrophages acutely and chronically infected with human immunodeficiency virus. 969 21

Saquinavir (Ro 31-8959; SQV) has been demonstrated to be a potent inhibitor of human immunodeficiency virus (HIV) proteinases and acts synergistically with dideoxynucleoside analogues. The aim of this study was to investigate the in vitro immunomodulatory effects of SQV on normal human peripheral blood mononuclear cells (PBMC) and on lamina propria mononuclear cells (LPMC). We used the drug either alone or in double and triple combination with AZT and ddC to assess whether SQV enhances the immunomodulatory effects induced by AZT and ddC that we previously observed. We demonstrated that SQV did not induce any modulation of the proliferative response either in PBMC or in LPMC. Similarly, NK cell-mediated cytotoxic activity and cytokine production were not modified by SQV. More importantly, SQV/AZT, SQV/ddC, and SQV/AZT/ddC combinations did not strengthen neither the inhibition of PBMC and LPMC proliferative response or the modulation of cytokine production induced by AZT, ddC, and AZT/ddC. On the other hand, the increased IL-2 production induced by AZT and ddC was not observed adding SQV to the dideoxynucleoside analogues. In conclusion, we demonstrated that SQV used in combination with AZT and ddC did not add any further immunotoxicity.
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PMID:Lack of immunotoxicity of saquinavir (Ro 31-8959) used alone or in double or triple combination with AZT and ddC. 979 27

The human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs)-saquinavir, ritonavir, nelfinavir, and indinavir-interact with the ABC-type multidrug transporter proteins MDR1 and MRP1 in CEM T-lymphocytic cell lines. Calcein fluorescence was significantly enhanced in MDR1(+) CEM/VBL100 and MRP1(+) CEM/VM-1-5 cells incubated in the presence of various HIV PIs and calcein acetoxymethyl ester. HIV PIs also enhanced the cytotoxic activity of doxorubicin, a known substrate for MDR1 and MRP1, in both VBL100 and VM-1-5 CEM lines. Saquinavir, ritonavir, and nelfinavir enhanced doxorubicin toxicity in CEM/VBL100 cells by approximately three- to sevenfold. Saquinavir and ritonavir also enhanced doxorubicin toxicity in CEM/VM-1-5 cells. HIV-1 replication was effectively inhibited by the various PIs in all of the cell lines, and the 90% inhibitory concentration for a given compound was comparable between the different cell types. Therefore, overexpression of MDR1 or MRP1 by T lymphocytes is not likely to limit the antiviral efficacy of HIV PI therapy.
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PMID:Human immunodeficiency virus protease inhibitors serve as substrates for multidrug transporter proteins MDR1 and MRP1 but retain antiviral efficacy in cell lines expressing these transporters. 1073 63

The goal of this study was to develop a fast, inexpensive and quantitative method for serum determination of the human immunodeficiency virus protease inhibitors Crixivan (C), Viracept (V), Invirase (I) or Fortovase (F), and Norvir (N), using common conditions for isolation and analysis. The best separation procedure developed thus far involves uncoated silica capillary and a buffer containing formic acid and acetonitrile. This procedure allows us to analyze three drugs (C, V and I or F) in 15 min. Norvir requires different analytical conditions. These four drugs are isolated from patient sera with a mixture of ethyl acetate and hexane. Sensitivity of the capillary zone electrophoresis protocols is sufficient for the detection of these pharmacological agents at the lowest clinically relevant concentrations (0.1 microgram/ml).
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PMID:Determination of human immunodeficiency virus-1 protease inhibitors in patient serum using free solution capillary zone electrophoresis. 1048 50


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