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Biomedical subjects

H C Lane

Publications and source records attributed to H C Lane.

At least 19 recordsLinked to original sources

Participation of tyrosine phosphorylation in the cytopathic effect of human immunodeficiency virus-1.

Protein tyrosine phosphorylation is a common mechanism of signaling in pathways that regulate T cell receptor-mediated cell activation, cell proliferation, and the cell cycle. Because human immunodeficiency virus (HIV) is though to affect normal cell signaling, tyrosine phosphorylation may be associated with HIV cytopathicity. In both HIV-infected cells and transfected cells that stably express HIV envelope glycoproteins undergoing HIVgp41-induced cell fusion, a 30-kilodalton protein was phosphorylated on tyrosine with kinetics similar to those of syncytium formation and cell death. When tyrosine phosphorylation was inhibited by the protein tyrosine kinase inhibitor herbimycin A, envelope-mediated syncytium formation was coordinately reduced. These studies show that specific intracellular signals, which apparently participate in cytopathicity, are generated by HIV and suggest strategies by which the fusion process might be interrupted.

Benzoquinones

Sinusitis in HIV-1 infection.

PURPOSE: To determine the clinical and radiographic characteristics of sinusitis in patients with human immunodeficiency virus type 1 (HIV-1) infection. PATIENTS AND METHODS: A retrospective study was performed that identified all HIV-1-infected patients with sinus radiographs, sinus computed tomograms, or magnetic resonance imaging of the head between 1982 and 1989 (n = 145). Medical record review detailed the clinical course and laboratory parameters in all patients. RESULTS: Eighty-nine patients had radiographic evidence of sinusitis; 75 patients had adequate clinical data and comprise the study group. Acute sinusitis was seen in 10 patients (13%), while all 75 patients had mucosal thickening indicative of chronic sinusitis. Fifty patients (67%) were symptomatic with fever, nasal congestion or discharge, and headache being the most common symptoms; nineteen patients (25%) were asymptomatic when their radiographs showed active disease. The mean CD4 count for the group was 276 cells/mm3; 32 (43%) had CD4 counts less than or equal to 100 cells/mm3. Twenty-three patients (31%) received antibiotics orally, parenterally, or both. CONCLUSIONS: Sinusitis appears to occur frequently in HIV-infected patients, is often asymptomatic, may be recurrent or refractory, and may be associated with declining immunocompetence in HIV-infected patients.

Adult

Prevention of the spread of HIV-1 infection with nonnucleoside reverse transcriptase inhibitors.

Certain bisheteroarylpiperazines (BHAPs) directly inhibit the replication of human immunodeficiency virus type 1 (HIV-1) and block the spread of infection to susceptible populations of cells. At a 1 microM concentration three analogs, U-87201, U-88204, and U-89674, inhibited the replication of HIV-1 in MT-2 cells by 83, 100, and 93%, respectively. At the same concentration, U-88204 completely inhibited replication of primary HIV-1 isolates in peripheral blood mononuclear cells. Replication of 3'-azido-2',3'-dideoxythymidine (AZT)-resistant strains of HIV-1 was also inhibited by U-88204. When MT-2 cells that were lytically infected with HIV-1 were mixed with uninfected MT-2 cells, U-88204 provided complete protection to the uninfected cells. Integrated proviral DNA sequences were not detected by the polymerase chain reaction technique in this culture after 15 days in the presence of drug. The resultant healthy cell culture was subsequently maintained without drug with no evidence of latent proviral DNA. Serial passage of a laboratory strain and a primary isolate of HIV-1 in cell culture in the presence of increasing concentrations of U-88204 yielded virus populations which were at least 100-fold resistant to the drug. These resistant viruses also showed cross-resistance to the pyridinone class of nonnucleoside inhibitors but were sensitive to AZT. Analysis of the nucleotide sequence of resistant viruses revealed mutations at conserved regions of the reverse transcriptase (RT) gene. The results presented here suggest the therapeutic potential of U-88204 in the combination therapy for HIV-1 infection.

Cell Line

Current status of therapy for human immunodeficiency virus type 1.

The past year has been refinement in our ability to delay the progression of human immunodeficiency virus type 1 infection through the use of nucleoside analogues, singly or in combination. Progress has also been made in our ability to detect drug-resistant isolates of human immunodeficiency virus type 1 and to begin to put the laboratory observations of resistance into a clinical context.

CD4-CD8 Ratio

Isolation of HIV-1 from plasma of infected individuals: an analysis of experimental conditions affecting successful virus propagation.

Experimental conditions affecting the successful propagation of HIV-1 from the plasma of seropositive individuals were examined. It was determined that whole blood samples collected with lithium heparin as the anticoagulant, immediate plasma separation, and immediate culturing were best suited for obtaining viable virus from plasma. Virus was isolated by infecting fresh phytohemagglutinin-stimulated normal donor peripheral blood mononuclear cells (PBMCs) with plasma followed by weekly cocultivation with new target cells. The plasma virus isolation rate was the greatest and HIV-1 titers were the highest for those individuals with less than 200 CD4+ cells/mm3 and decreased as the level of CD4+ cells approached normal values. We were able to obtain positive cultures from 29.5% of those patients with CD4+ counts greater than 500/mm3. HIV-1 titers in plasma also correlated with high serum p24 antigen levels when serum was treated with glycine to dissociate antigen-antibody complexes.

Adult

Envelope-specific antibodies in the saliva of individuals vaccinated with recombinant HIV-1 gp160.

HIV-1-specific antibodies have been detected in the saliva of seropositive individuals and may play a role in preventing oral transmission of the virus. We have analyzed saliva samples obtained from HIV-1-seronegative individuals who were immunized with various dosages of a recombinant HIV-1 envelope glycoprotein (gp160) vaccine for the presence of antibodies to HIV-1. Antibodies specific for envelope glycoproteins were detected in saliva from all of the volunteers, with those vaccinated with the higher doses of 640 and 1,280 micrograms showing the strongest responses. Peak salivary antibody titers were obtained 4-14 weeks after vaccination; they then gradually dropped in parallel with serum antibody titers. These envelope-specific antibodies were detected in whole saliva and in submandibular saliva but not in parotid saliva, suggesting that the source of antibodies in saliva is from serum transudation. The class of reactive antibodies was found to be IgG. The HIV-1-specific antibodies in the saliva of vaccinated individuals may offer local protection against HIV-1 infection.

AIDS Vaccines

Immunoregulation, immune defects, and clinical strategies in HIV infection.

In summary, patients with HIV infection have a variety of immunologic defects. The hallmark defect is a decrease in the number and function of helper-inducer or CD4 T lymphocytes. A decrease in CD4 count to less than 200 is associated with the development of opportunistic infections. The earliest functional defect is in soluble antigen recognition. Although there is an increase in the number of suppressor cytotoxic or CD8 T lymphocytes, there is a decrease in their function, presumably due to a lack of inductive signals from the CD4 T cells. Decreases in natural killer cell function occur, as does polyclonal B cell activation, which makes serologic diagnosis of opportunistic infections somewhat unreliable. Finally, there are also variable decreases in the function of the reticuloendothelial system.

Acquired Immunodeficiency Syndrome

Frequent detection of HIV-1-specific mRNAs in infected individuals suggests ongoing active viral expression in all stages of disease.

It has been shown that only a small fraction of CD4+ T cells are infected with human immunodeficiency virus type 1 (HIV-1) in vivo, particularly early in the course of infection. An even smaller proportion of cells have been shown to be expressing virus. Recent studies suggest that plasma viremia in asymptomatic HIV-infected individuals, representing active viral replication, is more common than was previously believed (range 23-100% of patients). To determine the in vivo state of HIV expression, samples of peripheral blood of 49 HIV-infected individuals at all stages of disease were examined. All subjects were positive for viral DNA by standard polymerase chain reaction (PCR), and a modified PCR was utilized to detect HIV-specific mRNAs (gag, major splice junction, env, and tat/rev). Patient's plasma was also assayed for p24 antigen and viremia. The results were as follows: (formula: see text) Overall, the findings suggest that active viral expression occurs at all stages of HIV infection. In particular, the presence of gag mRNA was determined in only 2 of 14 patients with T4% greater than 30% but in 20 of 35 patients with T4% less than or equal to 30% (p less than 0.05), demonstrating a direct association between the presence of message for a structural protein, and more advanced immunosuppression. Determination of the expression of certain HIV-specific messages from within a patient's cells adds a new dimension to understanding the pathogenesis of HIV infection. The presence of HIV-specific mRNAs, and in particular gag message, in many healthy seropositives may further argue for early initiation of antiviral therapy.

Acquired Immunodeficiency Syndrome

A phase I/II trial of zidovudine, interferon-alpha, and granulocyte-macrophage colony-stimulating factor in the treatment of human immunodeficiency virus type 1 infection.

Twenty-four patients infected with human immunodeficiency virus type 1 (HIV-1) who had CD4+ counts of 0.2-0.5 x 10(9) cells/l received granulocyte-macrophage colony-stimulating factor (GM-CSF) in combination with zidovudine plus escalating doses of daily subcutaneous interferon-alpha. Mean neutropenia-inducing doses of interferon-alpha were 9.4 x 10(6) and 10.6 x 10(6) IU/day for groups receiving 100 or 200 mg zidovudine every 4 h, respectively. Mean GM-CSF doses used to reverse neutropenia were 0.64 and 0.63 microgram/kg/day for these two groups, respectively, although the mean minimum effective GM-CSF dose for both was only 0.30 microgram/kg/day. Serum p24 antigen declined greater than 70% in all 5 antigenemic patients. Toxicities included a dose-dependent increase in lymphokine-like side effects (100%), anorexia and weight loss (42%), fatigue (42%), and anemia (50%). While toxicities of the combination can be significant, low-dose GM-CSF readily ameliorated neutropenia associated with zidovudine and interferon-alpha therapy without adversely affecting the antiviral properties of the combination.

Administration, Oral

Effect of aerosolized pentamidine prophylaxis on the diagnosis of Pneumocystis carinii pneumonia by induced sputum examination in patients infected with the human immunodeficiency virus.

This study assessed the effect of aerosolized pentamidine prophylaxis on the clinical presentation and diagnostic sensitivity of induced sputum examination for Pneumocystis carinii pneumonia. Between January 1, 1988 and October 27, 1990, 348 induced sputum examinations were performed as the initial diagnostic procedure for P. carinii pneumonia in patients infected with the human immunodeficiency virus (HIV). Medical records were reviewed for all induced sputum examinations, and the study group consisted of patients who either had not received prophylactic therapy (n = 193) or had received aerosolized pentamidine prophylaxis (n = 126). A total of 29 induced sputum examinations in patients receiving either other prophylactic regimens or ongoing therapy for previously documented P. carinii pneumonia were excluded from the study group. A total of 72 consecutive episodes of P. carinii pneumonia were subsequently documented by induced sputum examination (n = 54), bronchoalveolar lavage (n = 16), thoracocentesis (n = 1), or autopsy (n = 1). A total of 44 episodes occurred in patients who had not received antipneumocystis prophylaxis, and 28 episodes occurred in patients who had received aerosolized pentamidine. Of patients capable of producing a sputum specimen for analysis, induced sputum examination had a significantly lower diagnostic yield of 64.3% in patients who had received aerosolized pentamidine prophylaxis compared with 92.3% in patients who did not receive prophylaxis (p less than 0.02, Fisher's exact test). When the data were analyzed on an intention to treat basis, although there was a trend suggesting a lower overall yield in the aerosolized pentamidine patients, the difference was not statistically significant (64.3 versus 81.8%, p = 0.17, Fisher's exact test).(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols

The role of alpha-interferon in patients with human immunodeficiency virus infection.

alpha-Interferon (IFN alpha) blocks replication of human immunodeficiency virus (HIV)-1 in vitro by interfering with the release of mature virions. Clinical trials have addressed the in vivo effects of IFN alpha, both alone and in combination with other agents, in a variety of patients at all stages of HIV-1 infection. Patients with late stages of HIV-1 infection (CD4 counts under 100) show few positive results following treatment with IFN alpha. Patients with earlier stages of HIV infection, however, may benefit from treatment with this agent. Several clinical trials have demonstrated the activity of interferon in the treatment of patients with acquired immunodeficiency syndrome, Kaposi's sarcoma, and CD4 counts over 200. In these trials, response rates of approximately 40% have been reported, with the probability of response directly correlated with the level of CD4 cells. These antitumor effects have been associated with declines in the circulating levels of the HIV-1 core antigen p24. alpha-Interferon activity has also been studied in patients concomitantly receiving zidovudine. In these studies, neutropenia, reversible with the concomitant administration of granulocyte macrophage colony-stimulating factor, has been the most common dose-limiting toxicity. Both the antitumor and antiviral activities of combination therapy appear to be at least as good as those observed when single agents are used. Controlled clinical trials are currently under way to evaluate the role of interferon therapy, both alone and in combination with zidovudine, in patients with early HIV infection.

Animals

Immunologic abnormalities in HIV infection.

The progressive decline in the number and function of circulating CD4+ T lymphocytes remains the most characteristic immunologic abnormality found in persons infected with HIV. With the CD4+ cell as the central element in the immunologic cascade of events involved in antigen recognition and host defense, loss of normal CD4 number and function results in impairment of many immune functions that require induction signals by CD4 lymphocytes, including CD8 function, B lymphocyte production of immunoglobulin, NK cell function, and monocyte/macrophage function. Although CD4 cell depletion is a major factor in the pathogenesis of HIV infection, immunologic abnormalities such as impairment of responses to soluble protein antigens appear even before detectable loss of circulating CD4 cells. Progression of clinical disease occurs despite the development of antibodies to HIV proteins. Cellular immune responses have been described in a limited number of individuals, but their exact role is not yet understood. Delineation of the precise nature of the immunologic defects in HIV infection should provide the basis for the continued development of better therapeutic strategies.

B-Lymphocytes

Risk for occupational transmission of human immunodeficiency virus type 1 (HIV-1) associated with clinical exposures. A prospective evaluation.

OBJECTIVES: To summarize the results of a 6-year, ongoing, prospective study of the risk for human immunodeficiency virus type 1 (HIV-1) transmission among health care workers, and to estimate the magnitude of the risk for HIV-1 infection associated with different types of occupational exposures. DESIGN: Prospective cohort study; the median follow-up for employees sustaining parenteral exposures was 30.2 months (range, 6 to 69 months). SUBJECTS: Health care workers at the Clinical Center, National Institutes of Health, including those reporting parenteral and nonparenteral occupational exposures to HIV-1. MEASUREMENTS AND MAIN RESULTS: One thousand three hundred and forty-four clinical health care workers reported 179 percutaneous and 346 mucous membrane exposures to fluids from HIV-1-infected patients during a 6-year period. Responding to a supplementary questionnaire, 559 of these workers reported 2712 cutaneous exposures to blood from HIV-1-infected patients and more than 10,000 cutaneous exposures to blood from all patients during a 12-month period. Occupational transmission of HIV-1 occurred in a single worker after a parenteral exposure to blood from an HIV-1-infected patient. No infections occurred after either mucous membrane or cutaneous exposures to blood from HIV-1-infected patients. Use of newer diagnostic technologies (for example, antigen detection, gene amplification) has not resulted in the identification of occupationally transmitted seronegative infections. CONCLUSIONS: Combining our results with those of other prospective studies, the risk for HIV-1 transmission associated with a percutaneous exposure to blood from an HIV-1-infected patient is approximately 0.3% per exposure (95% CI, 0.13% to 0.70%); the risks associated with occupational mucous membrane and cutaneous exposures are likely to be substantially smaller. These data support the use of barrier precautions and suggest a need for strategies that change health care providers' attitudes and behaviors.

Accidents, Occupational

Syngeneic bone marrow transplantation and adoptive transfer of peripheral blood lymphocytes combined with zidovudine in human immunodeficiency virus (HIV) infection.

OBJECTIVE: To examine the role of syngeneic bone marrow transplantation and peripheral blood lymphocyte infusions combined with zidovudine in the treatment of patients with human immunodeficiency virus (HIV) infection. DESIGN: A partially randomized outpatient trial. SETTING: Outpatient and inpatient facility of the Clinical Center of the National Institutes of Health, a research-based referral facility. PATIENTS: Sixteen patients with HIV infection (15 symptomatic, 1 asymptomatic). INTERVENTIONS: Symptomatic patients were treated with zidovudine, 500 mg orally every 4 hours for 12 weeks, combined with six peripheral blood lymphocyte infusions (four at week 10, two at week 12) and bone marrow transplantation (at week 12) using HIV-seronegative identical twins as donors. After transplantation, patients were randomly assigned to receive either zidovudine, 100 mg every 4 hours, or placebo for 12 months. The asymptomatic patient received zidovudine for the first 12 weeks, discontinuing therapy after transplantation. Immunologic and virologic monitoring were done monthly. MEASUREMENTS AND MAIN RESULTS: Immediately after lymphocyte infusions and bone marrow transplantation, there was an increase in the mean (+/- SE) CD4 cell percent (19.1% +/- 3.1% to 28.1% +/- 3.0%), an increase in the fraction of patients with delayed-type hypersensitivity responses to tetanus toxoid (4 of 13 to 11 of 13) and the development of delayed-type hypersensitivity to keyhole-limpet hemocyanin (a primary immunogen to which only the donor had been immunized) in 8 of 12 patients tested. No significant clinical improvement was noted, however, and there was no overall sustained immunologic improvement. No differences in CD4 cell percents, delayed-hypersensitivity skin tests, HIV cultures, or p24 antigenemia were seen between patients treated with zidovudine or placebo after transplantation. CONCLUSIONS: Although they establish the feasibility of combining zidovudine with cellular immune reconstitution in treating patients with HIV infection, our results show that any benefits from such combination therapy are at best transient. Future attempts at cellular immune reconstitution may need to use improved antiretroviral regimens as well as immunization of donors with HIV-specific antigens.

Adult

Increasing viral burden in CD4+ T cells from patients with human immunodeficiency virus (HIV) infection reflects rapidly progressive immunosuppression and clinical disease.

OBJECTIVE: To determine over time the relation between viral burden and immunologic decline in patients with asymptomatic human immunodeficiency virus (HIV) infection. DESIGN: Blind analysis of cell samples from matched cohorts for HIV proviral DNA by polymerase chain reaction, retrospective analysis of clinical data on patients, and prospective follow-up of patients seropositive for the human immunodeficiency virus type 1 (HIV-1). SETTING: National research clinic and academic medical centers. PATIENTS: Cohort 1 included 12 healthy HIV-1-seropositive patients (average follow-up, 14 months): Six patients had stable disease and 6 developed rapidly progressive disease. Cohort 2 included 15 healthy HIV-1-seropositive patients from the Multi-center AIDS Cohort Study (average follow-up, 32 months): Eight patients had stable disease and 7 developed rapidly progressive disease. LABORATORY STUDIES: Quantitative polymerase chain reaction was done to determine the HIV-1 viral burden in sort-purified CD4+ T cells obtained from patients at various timepoints. MEASUREMENTS AND MAIN RESULTS: In patients who remained asymptomatic, frequencies of HIV-infected CD4+ T cells were low (less than 1/10,000 to 1/1000) at study entry and increased only minimally (none higher than 1/1000). In contrast, among patients who developed HIV-related symptoms including the acquired immunodeficiency syndrome (AIDS) despite having similar CD4 counts, frequencies of HIV-infected CD4+ T cells were higher at entry (greater than 1/1000) and increased substantially (greater than 1/100) in most within 3 months of developing progressive disease. This increase in HIV burden coincided with a significant decline over time in the percent of T4 cells (31% to 16%), whereas the percent of T4 cells was unchanged in persons who remained asymptomatic (33% to 34%). CONCLUSIONS: Increasing viral burden in peripheral blood CD4+ T-cells is directly associated with a progressive decline in CD4+ T cells and deteriorating clinical course in HIV-infected patients.

CD4-Positive T-Lymphocytes

Interferon-alpha in patients with asymptomatic human immunodeficiency virus (HIV) infection. A randomized, placebo-controlled trial.

STUDY OBJECTIVE: To evaluate the toxicity and clinical efficacy of interferon-alpha 2b (IFN-alpha) in patients with asymptomatic human immunodeficiency virus (HIV) infection. DESIGN: Randomized, placebo-controlled, and double-blind study. SETTING: Outpatient clinic of a government referral-based research hospital. PATIENTS: Volunteer sample of 34 patients with asymptomatic HIV infection who had CD4 counts of 400 cells/mm3 or more, positive peripheral blood mononuclear cell cultures for HIV, or p24 antigenemia. INTERVENTIONS: Patients were randomly assigned to receive either IFN-alpha or placebo, 35 x 10(6) units per day subcutaneously. Doses of IFN-alpha or placebo were modified according to predefined laboratory and clinical criteria. Therapy lasted at least 12 weeks. MEASUREMENTS AND MAIN RESULTS: Seventeen patients were randomly assigned to each group. The two groups had similar mean CD4 counts at study entry. Thirty-five percent of patients assigned to receive IFN-alpha withdrew from the study because of toxicity. The average daily dose of IFN-alpha was 17.5 x 10(6) units. All patients receiving IFN-alpha reported flu-like symptoms; other toxicities included granulocytopenia (55%) and elevated liver enzyme levels (45%). While receiving IFN-alpha, 7 patients (41%) became HIV culture negative (three or more consecutive negative peripheral blood mononuclear cell cultures taken at least 2 weeks apart). In contrast, 2 patients in the placebo group (13%) became culture negative while on study (P = 0.05). During the treatment period, CD4 lymphocyte percentages were sustained at or above the baseline level in patients receiving IFN-alpha and declined slightly in patients receiving placebo. Of the 32 study patients followed after study (range, 5 to 33 months), no patients in the IFN-alpha group developed an acquired immunodeficiency syndrome (AIDS)-defining opportunistic infection, compared with 5 patients in the placebo group (P = 0.02). CONCLUSIONS: Treatment of early-stage HIV infection with IFN-alpha can result in a decrease in frequency of viral isolation. Although its use may be accompanied by dose-dependent toxicities, IFN-alpha may have a role in slowing progression of HIV disease.

Adolescent