Search PubMed⌕ Search

Biomedical subjects

M A Jacobson

Publications and source records attributed to M A Jacobson.

At least 55 records · Page 3Linked to original sources
PubMed1996

Zidovudine side effects as reported by black, Hispanic, and white/non-Hispanic patients with early HIV disease: combined analysis of two multicenter placebo-controlled trials.

The objective of this study was to determine whether HIV patients' subjective tolerance of zidovudine differs by racial or ethnic grouping by conducting a post hoc analysis of reported symptoms in two multicenter, placebo-controlled trials of zidovudine monotherapy for early HIV disease. Ratios of rates of developing new or worsening symptoms as reported by patients assigned to active drug or placebo were compared in groups of white/non-Hispanic, black, or Hispanic origin. Patients were included in the study if they had asymptomatic HIV disease and entry absolute CD4 lymphocyte counts below 500 cells/microL and were enrolled in National Institute of Allergy and Infectious Diseases AIDS Clinical Trials Group (ACTG) protocol 019 or had mild symptoms of HIV disease, were enrolled in ACTG protocol 016, met protocol eligibility criteria for the respective trial, and were categorized at entry as white/non-Hispanic (N = 1801), black (N = 195), or Hispanic (n = 214). The primary outcome measure was development of a new or worsening symptom of any severity. Among patients treated with zidovudine compared with placebo, the estimated risk for developing a new or worsening symptom was not significantly greater for blacks or Hispanics than for white/non-Hispanics for any of the most frequently reported symptoms (p > 0.05 after adjustment for the multiple comparisons performed). Our analysis of 195 black and 214 Hispanic patients did not reveal a significantly increased risk of subjective zidovudine intolerance compared with white/non-Hispanic subjects. If there is an increased risk of such intolerance in minority groups compared with white/non-Hispanics, it is not likely to be clinically important.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Diagnosis of neurosyphilis in patients infected with human immunodeficiency virus type 1.

Establishing the diagnosis of neurosyphilis may be particularly difficult in human immunodeficiency virus type 1 (HIV)-infected persons. Polymerase chain reaction (PCR) was used to detect Treponema pallidum DNA in cerebrospinal fluid (CSF) from 81 HIV-infected patients. On the basis of reactive serum and CSF-VDRL tests, 2 patients were diagnosed as having neurosyphilis. T. pallidum DNA was not consistently detected in any sample, even when the CSF-VDRL was reactive. CSF pleocytosis, elevated protein, or depressed glucose concentration was not significantly associated with a history of exposure to or infection with T. pallidum. On the basis of results of routine CSF measurements and T. pallidum PCR results, no evidence was found for undiagnosed neurosyphilis in HIV-infected patients. T. pallidum DNA PCR on CSF did not provide more information than conventional CSF analysis. Further study is needed to determine the utility of this test in the diagnosis and treatment of neurosyphilis.

DNA, Bacterial↗
PubMed1996

Interleukin-12 administered in vivo decreases human NK cell cytotoxicity and antibody-dependent cellular cytotoxicity to human immunodeficiency virus-infected cells.

Persons infected with human immunodeficiency virus (HIV) have cellular cytotoxicity defects. Interleukin (IL)-12 is a potent stimulator of cytotoxicity. Fifteen HIV-infected patients were studied in a phase 1, single-dose escalation trial of human recombinant IL-12. One day after subjects received an IL-12 dose of 300 or 1000 ng/kg, they had a reduction in absolute lymphocyte count and peripheral blood mononuclear cell recovery. In evaluable patients 24 h after IL-12 administration, there was a 31% reduction overall in NK cell cytotoxicity (NKC) to HIV-infected cells at all doses and a 52% reduction in antibody-dependent cellular cytotoxicity (ADCC) at doses of 300 and 1000 ng/kg. In vitro incubation of patients' cells with IL-12 (before IL-12 administration) for 24 h increased NKC but had no effect on ADCC. The paradoxic acute reduction in cell number and cytotoxicity in vivo may be due to NK cell trafficking or regulatory cytokine mechanisms not apparent in vitro.

Adolescent↗
PubMed1995

Stimulation by alkylxanthines of chloride efflux in CFPAC-1 cells does not involve A1 adenosine receptors.

A series of 8-substituted derivatives of 1,3,7-alkylxanthines was synthesized as potential activators of chloride efflux from a human epithelial cell line (CFPAC) expressing the cystic fibrosis transmembrane regulator (CFTR) delta F508 mutation. Their interactions with rat brain A1 and A2a receptors were also studied in radioligand binding experiments. Substitution was varied at the xanthine 1-, 3-, 7- and 8-positions. 1,3-Dipropyl-8-cyclopentylxanthine (CPX) stimulated Cl- efflux in the 10(-8) M range, with a maximal effect reaching 200% of control and diminishing at higher concentrations. The potent adenosine antagonist 8-[4-[[[[(2-aminoethyl)amino]carbonyl]methyl]oxy]phenyl]- 1,3-dipropylxanthine, nonselective at human A1 and A2a receptors, was inactive in Cl- efflux. 1,3-Diallyl-8-cyclohexylxanthine (DAX) was highly efficacious in stimulating chloride efflux with levels reaching > 300% of control, although micromolar concentrations were required. 1,3,7-Trimethyl-8-(3-chlorostyryl)xanthine, an A2a-selective adenosine antagonist, was only weakly active. Caffeine, which acts as an nonselective adenosine antagonist in the range of 10(-5) M, was active in Cl- efflux in the low nanomolar range but with low efficacy. Thus, among the xanthine derivatives of diverse structure, there was no correlation between potency in Cl- efflux and adenosine antagonism. Poly(A)+ RNA isolated from CFPAC-1 cells showed no hybridization to a human A1 receptor cDNA probe, excluding this receptor as a mediator of CPX-elicited Cl- efflux. Thus, this action of xanthines in stimulating Cl- efflux in CFPAC cells, which express a defective CFTR, represents a novel site of action apparently unrelated to adenosine receptors.

Animals↗
PubMed1995

Cloning and chromosomal localization of the human A2b adenosine receptor gene (ADORA2B) and its pseudogene.

To determine the chromosomal localization of the human A2b adenosine receptor, the corresponding genomic clone was isolated and used as a probe for fluorescence in situ hybridization to metaphase chromosomes. Partial sequence analysis of the A2b gene (AD-ORA2B) revealed an intron that interrupted the coding region corresponding to the second intracellular loop similar to that reported for A1 and A2a adenosine receptor genes. A pseudogene for the A2b receptor was also identified; it exhibited 79% identity to the A2b adenosine receptor cDNA coding sequence and contained multiple deletions, point mutations, and frame shifts and two in-frame stops. These changes would result in the inability to encode a functional receptor. The genomic clones were utilized to localize the A2b receptor to chromosome 17p12 and the A2b pseudogene to chromosome 1q32.

Chromosome Mapping↗
PubMed1995

Foscarnet and ganciclovir pharmacokinetics during concomitant or alternating maintenance therapy for AIDS-related cytomegalovirus retinitis.

INTRODUCTION: The use of foscarnet and ganciclovir as a combination treatment for cytomegalovirus retinitis is increasing because of limitations associated with single agent therapy. METHODS: The pharmacokinetics of foscarnet and ganciclovir were determined in 13 patients receiving either concomitant therapy (regimen A) or daily alternating therapy (regimen B) for maintenance of cytomegalovirus disease. For regimen A, 60 mg/kg intravenous foscarnet and 3.75 mg/kg ganciclovir were sequentially administered daily; for regimen B, 120 mg/kg foscarnet and 6 mg/kg ganciclovir were administered on alternating days. For both regimens, serial blood sampling for pharmacokinetic analysis was performed for each drug alone (day 1 or 2) and after 2 weeks of combination therapy. Plasma samples for foscarnet and ganciclovir analysis were performed by means of high-performance liquid chromatography. Pharmacokinetic analysis was performed with noncompartmental methods. RESULTS: For regimen A, the plasma clearance (CL) of foscarnet did not change in the presence of ganciclovir, averaging 0.12 +/- 0.08 and 0.11 +/- 0.02 L/hr/kg on study days 2 and 14, respectively (p = 0.34). The volume of distribution (VSS) and mean residence time (MRT) also did not change significantly. CL and MRT of foscarnet did not change for regimen B, although a slight increase in VSS was observed before (0.38 +/- 0.05 L/kg) and after (0.46 +/- 0.07 L/kg) alternating therapy (p = 0.03). Ganciclovir CL did not change for either regimen, with mean values of 0.21 +/- 0.10 and 0.25 +/- 0.10 L/hr/kg (regimen A, p = 0.17) and 0.32 +/- 0.10 and 0.34 +/- 0.11 L/hr/kg (regimen B, p = 0.24). MRT and VSS were also not significantly different. CONCLUSION: These plasma data suggest that further dosage adjustments are unnecessary for or alternating maintenance therapy.

AIDS-Related Opportunistic Infections↗
PubMed1995

Dose-related difference in progression rates of cytomegalovirus retinopathy during foscarnet maintenance therapy. AIDS Clinical Trials Group Protocol 915 Team.

PURPOSE: A previous dose-ranging study of foscarnet maintenance therapy for cytomegalovirus retinopathy showed a positive relationship between dose and survival but could not confirm a relationship between dose and time to first progression. This retrospective analysis of data from that study was undertaken to determine whether there was a relationship between dose and progression rates, which reflects the amount of retina destroyed when progression occurs. METHODS: Patients were randomly given one of two foscarnet maintenance therapy doses (90 mg/kg of body weight/day [FOS-90 group] or 120 mg/kg of body weight/day [FOS-120 group] after induction therapy. Using baseline and follow-up photographs and pre-established definitions and methodology in a masked analysis, posterior progression rates and foveal proximity rates for individual lesions, selected by prospectively defined criteria, were calculated in each patient. Rates were compared between groups. RESULTS: The following median rates were greater for the FOS-90 group (N = 8) than for the FOS-120 group (N = 10): greatest maximum rate at which lesions enlarged in a posterior direction (43.5 vs 12.5 microns/day; P = .002); posterior progression rate for lesions closest to the fovea (42.8 vs 5.5 microns/day; P = .010); and maximum foveal proximity rate for either eye (32.3 vs 3.4 microns/day; P = .031). CONCLUSION: Patients receiving higher doses of foscarnet have slower rates of progression and therefore less retinal tissue damage during maintenance therapy. A foscarnet maintenance therapy dose of 120 mg/kg of body weight/day instead of 90 mg/kg of body weight/day may help to preserve vision in patients with cytomegalovirus retinopathy.

AIDS-Related Opportunistic Infections↗
PubMed1995

Pharmacokinetic, safety, and antiviral profiles of oral ganciclovir in persons infected with human immunodeficiency virus: a phase I/II study. AIDS Clinical Trials Group, and Cytomegalovirus Cooperative Study Group.

A phase I/II study evaluated the pharmacokinetics, tolerability, and antiviral activity of oral ganciclovir in persons infected with human immunodeficiency virus (HIV). Oral bioavailability ranged from 2.6% to 7.3%. The mean maximum serum concentration achieved at 1000 mg every 8 h was 1.11 micrograms/mL, and mean trough level was 0.54 microgram/mL. The time to maximum serum drug concentration was 1.0-2.9 h, with a serum half-life of 3.0-7.3 h, suggesting prolonged oral absorption. Serious adverse events were uncommon. Decreased cytomegalovirus (CMV) shedding was observed from all sites. The median days (by dosage) to retinitis progression assessed by retinal examination after initiation of oral ganciclovir were 62 (1000 mg every 8 h), 148 (500 mg every 3 h), 75 (750 mg every 3 h), 148 (1000 mg every 3 h), and 139 (2000 mg every 8 h). Thus, oral ganciclovir has pharmacokinetic, toxicity, and antiviral profiles that may prove beneficial for both maintenance therapy of CMV retinitis and prevention of CMV disease in HIV-infected persons.

Administration, Oral↗
PubMed1995

The predictive value of changes in serologic and cell markers of HIV activity for subsequent clinical outcome in patients with asymptomatic HIV disease treated with zidovudine.

OBJECTIVE: To determine if serologic marker responses to zidovudine treatment during the first year of antiretroviral therapy could predict subsequent HIV disease progression independently of absolute CD4 lymphocyte responses. METHODS: We conducted a case-control study in patients with asymptomatic HIV disease, who were initiating zidovudine therapy in a randomized, prospective trial. A total of 102 patients who progressed to AIDS or advanced AIDS-related complex and 177 randomly selected controls matched by baseline CD4 cell count and duration of follow-up had serum samples (from prior to and at 8, 16, 32 and 48 weeks of zidovudine treatment) assayed for acid-disassociated HIV p24 antigen, beta 2-microglobulin (beta 2M), neopterin, soluble interleukin (IL)-2 receptor, soluble CD4 protein and soluble CD8 protein. RESULTS: Median time to event for cases was 20.2 months; median follow-up on study was 35.4 months for controls. After controlling for absolute CD4 count at baseline, increased baseline serum concentrations of HIV p24 antigen, beta 2M, neopterin, and soluble IL-2 receptor were highly predictive of increased risk of HIV disease progression. In a multiple logistic regression model, controlling for baseline marker values, change in beta 2M consistently added independent value to change in CD4 count in predicting subsequent risk of disease progression. CONCLUSIONS: Monitoring serum immunologic markers, in particular beta 2M, in addition to absolute CD4 lymphocyte counts prior to and within the first 4 months after initiating dideoxynucleoside therapy can increase the accuracy of estimations of subsequent long-term risk of clinical HIV disease progression. This information may be useful to clinicians and patients who are making decisions about initiating or changing antiretroviral therapy.

AIDS-Related Complex↗
PubMed1995

Update (1995) on clinical trials of antiviral therapy and prophylaxis for AIDS-related cytomegalovirus disease.

An overview of the current state of antiviral therapy and prophylaxis for opportunistic cytomegalovirus (CMV) disease in 1995 is provided, focusing primarily on therapeutic trials for AIDS-related CMV retinitis. Retinitis is the most common serious CMV end-organ disease in AIDS; and it is the one for which clinical end-points can be measured most objectively and precisely. Standard antiviral chemotherapy for CMV retinitis consists of chronic intravenous treatment with either ganciclovir or foscarnet, each of which significantly delays loss of vision compared to no treatment. New agents such as HPMPC and new treatment strategies such as intravitreal ganciclovir may be more effective than standard treatment in delaying time to retinitis progression but are associated with serious toxicity problems. Preliminary data from a placebo-controlled trial of oral ganciclovir suggest that this agent reduces the risk of developing CMV end-organ disease by 50%; however, the implications of oral ganciclovir prophylaxis for development of antiviral drug resistance are unknown.

AIDS-Related Opportunistic Infections↗
PubMed1994

Microbiology of community-acquired bacterial pneumonia in persons with and at risk for human immunodeficiency virus type 1 infection. Implications for rational empiric antibiotic therapy.

BACKGROUND: Bacterial pneumonia is a very common cause of morbidity and mortality among persons with human immunodeficiency virus; however, the microbiologic characteristics (including antibiotic resistance) of bacterial pathogens causing community-acquired pneumonia in this population have not been well characterized or correlated with potentially predictive clinical presentation characteristics. METHODS: We conducted a retrospective cohort study of all adults known to have or to be at high risk for human immunodeficiency virus infection and hospitalized at San Francisco (Calif) General Hospital from May 1990 through April 1991, with a hospital discharge diagnosis of community-acquired bacterial pneumonia and for whom a medical records review confirmed that this diagnosis met a uniform case definition. RESULTS: Two hundred sixteen eligible patients had one or more hospital admissions meeting the case definition. One or more etiologic pathogens were definitively identified in 75% of cases, with Streptococcus pneumoniae, Haemophilus species, Staphylococcus aureus, and gram-negative bacilli most frequently identified. In patients who had a bacteriologic diagnosis made, 18.6%, 6.8%, and 4.3% had pneumonia caused by pathogens resistant to ampicillin sodium, cefuroxime sodium, or trimethoprim-sulfamethoxazole, respectively. One hundred percent of pathogens isolated were susceptible to ceftazidime. Anemia and use of antibacterial medication at the time of hospital admission were the only independent predictors of ampicillin and cefuroxime resistance. CONCLUSION: Nearly one fifth of human immunodeficiency virus-associated community-acquired bacterial pneumonias requiring hospitalization were caused by ampicillin-resistant pathogens, and presenting clinical characteristics did not consistently define a subset of patients at lower risk for resistance. In the absence of a diagnostic sputum Gram's stain and pending definitive microbiologic diagnosis, initial empiric therapy should be with a second- or third-generation cephalosporin or possibly trimethoprim-sulfamethoxazole.

AIDS-Related Opportunistic Infections↗
PubMed1994

Current management of cytomegalovirus disease in patients with AIDS.

Cytomegalovirus (CMV) infection is common in both homosexual and heterosexual HIV-infected patients, and causes disease in a substantial proportion of patients with AIDS and very low CD4+ cell counts. Both ganciclovir, an analog of the nucleoside guanosine, and foscarnet, an analog of pyrophosphate, are licensed for treatment of CMV retinitis. They may also have a role in the treatment of gastrointestinal disease caused by CMV. In the Studies of Ocular Complications of AIDS comparative trial the two agents were equally effective against CMV retinitis, but patients receiving foscarnet had significantly longer survival, even after adjusting for covariates including antiretroviral therapy. Ongoing studies are evaluating higher dosages of foscarnet for maintenance therapy and combined therapy with ganciclovir and foscarnet. Tolerance of ganciclovir therapy has been facilitated by adjunctive therapy with colony-stimulating factors. Because both ganciclovir and foscarnet must be administered by intravenous infusion and are associated with significant toxicities, other anti-CMV agents are under active development, including HPMPC and an oral formulation of ganciclovir. Management of CMV retinitis involves individualizing therapy, balancing side effects and administration requirements, and, in many clinical settings, the overall cost of treatment.

AIDS-Related Opportunistic Infections↗
PubMed1994

Mycobacterium avium complex in the respiratory or gastrointestinal tract and the risk of M. avium complex bacteremia in patients with human immunodeficiency virus infection.

Mycobacterium avium complex (MAC) is frequently isolated from the respiratory or gastrointestinal tract of patients with advanced human immunodeficiency virus (HIV) infection. Whether they are at increased risk of MAC bacteremia and whether culture of respiratory tract or stool specimens is useful for predicting bacteremia are unclear. HIV-infected patients with < or = 50 CD4+ cells/microL were prospectively studied. The risk of MAC bacteremia was approximately 60% within 1 year for patients with MAC in either the respiratory or gastrointestinal tract and was greater than for those without MAC in these sites (relative hazards for respiratory and gastrointestinal tract, 2.3 and 6.0; 95% confidence intervals, 1.1-4.6 and 2.5-14.6, respectively). Both respiratory tract specimen and stool culture had poor sensitivities (22% and 20%, respectively) but good positive predictive values (approximately 60%) for bacteremia. Symptomatic HIV-infected patients with MAC in the respiratory or gastrointestinal tract are at a substantial risk for developing MAC bacteremia; culture of these sites has limited usefulness as a screening test.

Adult↗
PubMed1994

Primary prophylaxis with pyrimethamine for toxoplasmic encephalitis in patients with advanced human immunodeficiency virus disease: results of a randomized trial. Terry Beirn Community Programs for Clinical Research on AIDS.

Pyrimethamine, 25 mg thrice weekly, was evaluated as primary prophylaxis for toxoplasmic encephalitis (TE) in a double-blind, randomized clinical trial in patients with human immunodeficiency virus (HIV) disease, absolute CD4 lymphocyte count of < 200/microL (or prior AIDS-defining opportunistic infection), and the presence of serum IgG to Toxoplasma gondii. Leucovorin was coadministered only for hematologic toxicity. There was a significantly higher death rate among patients receiving pyrimethamine (relative risk [RR], 2.5; 95% confidence interval [CI], 1.3-4.8; P = .006), even after adjusting for factors predictive of survival. The TE event rate was low in both treatment groups (not significant). Only 1 of 218 patients taking trimethoprim-sulfamethoxazole but 7 of 117 taking aerosolized pentamidine for prophylaxis against Pneumocystis carinii pneumonia developed TE (adjusted RR for the trimethoprim-sulfamethoxazole group, 0.16; 95% CI, 0.01-1.79; P = .14). Thus, for HIV-infected patients receiving trimethoprim-sulfamethoxazole, additional prophylaxis for TE appears unnecessary.

AIDS-Related Opportunistic Infections↗
PubMed1994

Randomized phase I trial of two different combination foscarnet and ganciclovir chronic maintenance therapy regimens for AIDS patients with cytomegalovirus retinitis: AIDS clinical Trials Group Protocol 151.

AIDS patients with newly diagnosed cytomegalovirus (CMV) retinitis who had just completed a 14-day course of ganciclovir induction therapy were randomly assigned to an alternating or concurrent combination regimen of chronic ganciclovir-foscarnet therapy for CMV retinitis. Each regimen used lower weekly cumulative doses of each drug than standard monotherapy maintenance treatment regimens. Dose-limiting toxicity attributable to foscarnet occurred in only 2 (7%) of 29 evaluatable patients, and no patients experienced dose-limiting nephrotoxicity. Although absolute neutrophil counts < 500 cells/microL occurred in 11 (38%) of 29 patients, all who subsequently used adjunctive granulocyte colony-stimulating factor had severe neutropenia prevented. Severe toxicity of any type and neutropenia, in particular, occurred significantly more frequently in patients assigned to the concurrent treatment regimen. CMV was isolated from none of 21 patients who had urine cultured and from only 1 of 24 who had blood cultured while being treated during the study (median evaluation, 12 weeks). This suggests that combination therapy provides better in vivo antiviral activity in suppressing CMV replication than previously reported with monotherapy regimens.

AIDS-Related Opportunistic Infections↗