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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A method is described for detection of nonoxynol in condoms, based on methanol-water extraction followed by reverse-phase high-performance liquid chromatography. Using this method, we found that approximately 50% of the nonionic surfactant lubricant nonoxynol migrated into elastomers (rubber latex), resulting in a concentration of nonoxynol insufficient to inhibit human immunodeficiency virus (HIV) (less than 0.05%). In order to minimize the risk of sexual transmission of HIV, and to ensure spermicidal effect and optimal rubber properties, the concentration of nonoxynol in condoms, therefore, should either be increased, or nonoxynol should be packed separately. Further studies are needed to clarify and determine the solubility and migration of nonoxynols into elastomers.
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PMID:Evaluation of the amount of nonoxynol available in condoms for the inhibition of HIV using a method based on HPLC. 196 70

A flow cytometric assay has been developed to detect and quantitate human immunodeficiency virus (HIV)-infected peripheral blood mononuclear cells obtained from HIV-seropositive patients. Peripheral blood was obtained from patients attending an acquired immune deficiency syndrome clinic, and mononuclear cells were separated by centrifugation onto Ficoll-Hypaque. The cell layer at the interface was removed, washed in phosphate-buffered saline without Ca2+ and Mg2+, and fixed with 90% methanol, and intracellular HIV antigens were detected by indirect immunofluorescence with monoclonal antibodies to HIV antigens as the primary antibody and fluorescein isothiocyanate-conjugated goat anti-mouse immunoglobulin G F(ab')2 antibody as the secondary antibody. DNA content was determined by propidium diiodide staining after RNase treatment. These fluorochrome-treated cells were analyzed for two-color fluorescence by flow cytometry. The results showed that HIV-infected cells in peripheral blood that have been treated with monoclonal antibodies to the p24 or nef antigens of HIV can be detected and quantitated by flow cytometry. The percentage of p24 antigen-positive mononuclear cells had a significant correlation (P = 0.0001) with the clinical status of the patient, i.e., those with a high percentage of p24 antigen-positive cells had a poorer prognosis than those with a lower percentage of p24 antigen-positive mononuclear cells. In addition, for those in Centers for Disease Control groups III and IV, there was an inverse correlation between the percentage of p24 antigen-positive mononuclear cells and the number of T4 cells. However, cell-associated antigen detection by flow cytometry did not correlate with detection of antigen in sera of HIV-seropositive patients by the standard antigen capture enzyme-linked immunosorbent assay. This lack of correlation was probably due to the presence of immune complexes in the sera of HIV-seropositive patients. These results suggest that flow cytometry can be used as a rapid, sensitive, and quantitative assay system for the determination of the antigen status of HIV-seropositive patients and that it may be more useful as an indicator of disease progression than the currently used antigen detection methods.
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PMID:Detection and quantitation of human immunodeficiency virus-infected peripheral blood mononuclear cells by flow cytometry. 197 May 76

Effects of cell fixation procedures appropriate for flow cytometric analysis on the infectivity of human T lymphoblastoid H9 cells infected with human immunodeficiency virus-1 (HIV-1) were evaluated to provide guidelines for choosing cell treatments for potentially infectious samples. H9 cells experimentally infected with HIV-1 were treated by the test fixation procedure, washed, and cocultured with equal numbers of live, uninfected H9 cells. To estimate the reduction in infectivity due to the fixation procedure, dilution series of live infected H9 cells in uninfected H9 cells were simultaneously established in culture. Cell cultures were incubated 8-10 d, harvested, and evaluated for evidence of HIV-1 infection by the presence of cell-associated HIV-1 antigens and/or by the presence of particle-associated reverse transcriptase activity in cell culture supernatants. Thirty-minute fixation with formaldehyde (1.85%), methanol (absolute), methanol:acetone (1:1), or paraformaldehyde (0.5%) reduced the infectivity of HIV-1-infected H9 cells by greater than 99.99%. To the same degree, a multi-step fixation procedure utilizing formaldehyde and ethanol was effective in reducing HIV-1 infectivity. Conversely, the erythrocyte fixative dimethylsuberimidate at 3 micrograms/ml was ineffective in reducing HIV-1 infectivity.
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PMID:Effects of cellular fixatives on human immunodeficiency virus production. 237 57

Flow cytometric detection of human immunodeficiency virus (HIV)-infected lymphoid cells at low frequencies is described. Infected cells from human T lymphoid cell lines H9 and A3.01 were detected at frequencies as low as 10(-4) following indirect immunofluorescence labeling. For labeling, cells were treated with an HIV-inactivating, permeabilizing fixative followed by binding of a monoclonal antibody specific for the HIV major core protein p24, and then by binding of fluorescein isothiocyanate-conjugated F(ab')2 fragments of goat anti-mouse immunoglobulin antibody. We compared two fixation procedures, one using a mixture of methanol and acetone, the other a three-step fixation using methanol, paraformaldehyde and Triton X-100. The latter fixation protocol was found to be superior in its ability to resolve mixtures of infected and uninfected cells. The method allowed determination of the percentage of the cell population that was infected and the relative amount of p24 antigen per cell. At analysis rates of several thousand cells/s, detection of HIV-infected cells as rare events was possible. Excellent agreement was obtained between flow cytometric evaluation and reverse transcriptase (RT) assay of infected H9 cells cocultured with uninfected H9 cells in various proportions for 7 days. In time course of infection experiments, cultures infected by small numbers of viral particles were positive by flow cytometry up to 3 days earlier than by RT assay.
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PMID:Detection of human immunodeficiency virus-infected lymphoid cells at low frequency by flow cytometry. 244 28

Four cell fixation procedures were investigated for their abilities to inactivate human immunodeficiency virus (HIV) and preserve its antigenicity for antibody detection by immunofluorescence in MOLT-4-T4 cells. Air-dried cell smears were fixed in cold acetone, in acetone-methanol (1:1), in acetone-methanol (1:1) followed by 70% ethanol and then methanol, or in paraformaldehyde-acetone. Acetone alone did not inactivate cell-associated HIV, but the other three procedures did. HIV inactivation was achieved by storage of acetone-fixed cells at -70 degrees for 40 days. Antigenicity was measured by immunofluorescence assay titrations of selected human sera, a cerebrospinal fluid, and a gp41 monoclonal antibody. Acetone provided the best fixation as measured by fluorescence intensity and antibody titers. The other fixation methods all yielded weaker fluorescence signals and/or decreased titers. Acetone fixation and storage for 40 days at -70 degrees C provides safe and accurate immunofluorescence assay reagents.
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PMID:Immunofluorescence assay for human immunodeficiency virus antibody: investigation of cell fixation for virus inactivation and antigen preservation. 267 Oct 31

Carbovir is a novel carbocyclic guanosine derivative that has potent in vitro activity against human immunodeficiency virus, the causative agent of acquired immunodeficiency syndrome (AIDS). Two methods of sample preparation were developed for the analysis of carbovir in rat blood. Solid-phase extraction on C18 extraction columns proved to be the most effective. Whole rat blood (200 microliters) was diluted with 0.8 ml of distilled water containing the internal standard. After two freeze-thaw cycles to lyse the red blood cells and subsequent centrifugation at 13,000 g, the supernatant was loaded on the C18 extraction columns. Carbovir and the internal standard were eluted with methanol-water (60:40). The extract was evaporated and reconstituted in mobile phase and the samples were injected onto a high-capacity reversed-phase column. The compounds were detected at 252 nm. Other nucleosides that could be used in the treatment of AIDS such as zidovudine and acyclovir did not interfere. Standard curves were linear over the concentration range 0.156-28.0 micrograms/ml (r2 greater than 0.99). The within-day coefficient of variation was less than 7.6% at all concentrations (n = 4). The between-day coefficient of variation ranged from 16.7 to 2.0% (n = 14). The limit of sensitivity was 0.05 micrograms/ml with a 200-microliters blood sample and the average extraction recovery was 74%. Carbovir was stable in rat blood for at least 4 h at 37 degrees C. The assay was used to determine the blood levels of carbovir in a rat after a 20 mg/kg intravenous dose.
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PMID:Liquid chromatographic assay of carbovir, a carbocyclic nucleoside active against human immunodeficiency virus. 275 56

Peripheral blood lymphocytes (PBL) from patients with various forms of primary and secondary immunodeficiencies and from 30 healthy control persons were examined for their capacity to show terminal B-cell maturation and immunoglobulin (Ig) synthesis in vitro following pokeweed mitogen (PWM) stimulation. PBL were cultured for 9 days with or without PWM and the percentages of B-cells or plasma cells with strongly positive cytoplasmic Ig (CIg+) were determined by indirect immunofluorescence on methanol fixed cytocentrifuged lymphocyte smears. In addition, newly synthesized IgA, IgG and IgM was measured in the cell free culture supernatant by means of a sensitive microplate ELISA. In 29 out of 30 control cultures the proportion of CIg+-cells increased markedly following 9-day stimulation with PWM. CIg+-cells and newly synthesized Ig were significantly correlated. In a group of 18 patients with common variable immunodeficiency (CVID) maturation to CIg+-cells was greatly impaired and the in vitro production of IgA and IgG was reduced. Two infants with severe combined immunodeficiency (SCID) failed to produce Ig prior to and following haplo-identical bone marrow transplantation despite the presence of immature B-cells. A heterogeneous group of secondary immunodeficiencies showed different forms of an impaired terminal B-cell maturation and a reduced capacity to synthesize Ig in vitro. The described PWM culture techniques in combination with the evaluation of CIg+-cells and the measurement of newly synthesized Ig in the culture supernatant proved to be a reliable in vitro correlate for terminal B-cell maturation and represent an important tool for the classification of humoral immunodeficiencies.
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PMID:[Terminal B-cell maturation and immunoglobulin synthesis in vitro in primary and secondary immune deficiencies]. 639 94

A high-performance liquid chromatographic (HPLC) assay has been developed for the determination of the antifungal drug fluconazole in saliva and plasma of patients infected with the human immunodeficiency virus (HIV). Samples can be heated at 60 degrees C for 30 min to inactivate the virus without loss of the analyte. The sample pretreatment involves a liquid-liquid extraction with chloroform-1-propanol (4:1, v/v). The chromatographic analysis is performed on a Lichrosorb RP-18 (5 microns) column by isocratic elution with a mobile phase of 0.01 M acetate buffer (pH 5.0)-methanol (70:30, v/v) and ultraviolet (UV) detection at 261 nm. The lower limit of is 100 ng/ml in plasma (using 500-microliters samples) and 1 microgram/ml in saliva (using 250-microliters samples) and the method is linear up to 100 micrograms/ml in plasma and saliva. At a concentration of 5 micrograms/ml the within-day and between-day precision in plasma are 7.1 and 5.7%, respectively. In saliva the within-day and between-day precision is 10.8% (at 5 micrograms/ml). The methodology is now being used in pharmacokinetic studies in HIV-infected patients in our hospital.
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PMID:High-performance liquid chromatographic determination of the antifungal drug fluconazole in plasma and saliva of human immunodeficiency virus-infected patients. 773 82

Groups of 5'-phosphonates of natural 2'-deoxynucleosides and ribonucleosides were synthesized by condensation of 3'-acetylated 2'-deoxynucleosides or 2',3'-substituted (2',3'-O-isopropylidene, 2',3'-O-methoxymethylene, or 2',3'-O-ethoxymethylene) ribonucleosides. As condensing agents, either N,N'-dicyclohexylcarbodiimide or 2,4,6-triisopropylbenzenesulphonyl chloride were used. Nucleoside 5'-ethoxycarbonyl-phosphonates were converted into corresponding nucleoside 5'-aminocarbonylphosphonates by the action of ammonia in methanol. All compounds were tested for inhibition of several viruses, including human herpes simplex virus type 2 and cytomegalovirus, but showed no activity. A few compounds insignificantly inhibited human immunodeficiency virus type 1 reproduction. Thymidine 5'-hydrogenphosphonate neutralized the anti HIV action of 3'-azido-3'-deoxythymidine, thus indirectly showing that it could be partly hydrolyzed in cell culture to corresponding thymidine.
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PMID:[Ribonucleoside and 2'-deoxyribonucleoside 5'-phosphonates: synthesis and antiviral activity]. 814 53

Using immunofluorescence microscopy we found that gp120 binds to the surface of rat dorsal root ganglia neurons and human neuroblastoma cells but not to rat fibroblasts or glial cells. The binding of gp120 to neurons was eliminated by pretreatment with trypsin, which removes cell-surface proteins, but not with chloroform: methanol, which removes glycolipids. As control, neuronal staining by antisulfatide antibodies was eliminated by pretreatment with chloroform: methanol but not with trypsin. The gp120 binding to neurons was also inhibited by the mouse monoclonal antibody 01, which binds to galactocerebroside and cross-reactive glycoproteins. These studies suggest that the receptor for gp120 on the surface of the dorsal root ganglia neurons is a glycoprotein. This interaction may mediate the effects of human immunodeficiency virus type 1 in sensory neuropathy.
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PMID:The gp120 glycoprotein of human immunodeficiency virus type 1 binds to sensory ganglion neurons. 825 May 36


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