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Biomedical subjects

M A Jacobson

Publications and source records attributed to M A Jacobson.

At least 37 records · Page 2Linked to original sources

Guidelines for the treatment of cytomegalovirus diseases in patients with AIDS in the era of potent antiretroviral therapy: recommendations of an international panel. International AIDS Society-USA.

OBJECTIVE: To provide recommendations for the treatment of acquired immunodeficiency syndrome-related cytomegalovirus (CMV) end-organ diseases, including retinitis, colitis, pneumonitis, and neurologic diseases. PARTICIPANTS: A 17-member panel of physicians with expertise in clinical and virological research and inpatient care in the field of CMV diseases. EVIDENCE: Available clinical and virological study results. Recommendations are rated according to the quality and strength of available evidence. Recommendations were limited to the treatment of CMV diseases; prophylaxis recommendations are not included. PROCESS: The panel was convened in February 1997 and met regularly through November 1997. Subgroups of the panel summarized and presented available information on specific topics to the full panel; recommendations and ratings were determined by group consensus. CONCLUSIONS: Although the epidemiological features of CMV diseases are changing in the setting of potent, combination antiretroviral therapy, continued attention must be paid to CMV diseases in patients infected with the human immunodeficiency virus to prevent irreversible endorgan dysfunction. The initial and maintenance treatment of CMV retinitis must be individualized based on the characteristics of the lesions, including location and extent, specific patient factors, and characteristics of available therapies among others. Management of relapse or refractory retinitis must be likewise individualized. Ophthalmologic screening for patients at high risk for retinitis or who have a prior diagnosis of extraretinal disease is recommended. Recommendations for gastrointestinal, pulmonary, and neurologic manifestations are included.

AIDS-Related Opportunistic Infections↗

Filgrastim prevents severe neutropenia and reduces infective morbidity in patients with advanced HIV infection: results of a randomized, multicenter, controlled trial. G-CSF 930101 Study Group.

OBJECTIVE: To assess the effect of filgrastim treatment on the incidence of severe neutropenia in patients with advanced HIV infection, and the effect of initial filgrastim treatment on prevention of infectious morbidity. DESIGN: Randomized, controlled, open-label, multicenter study. SETTING: Outpatient centers and physician offices. PATIENTS: Men and women aged > 13 years, who were HIV antibody-positive, and had a CD4 cell count < 200 x 10(6)/l, absolute neutrophil count (ANC) 0.75-1.0 x 10(9)/l, and platelet count > or = 50 x 10(9)/l within 7 days of randomization were eligible. Two hundred and fifty-eight patients entered and 201 completed the study. INTERVENTION: Daily filgrastim (starting at 1 microg/kg daily, adjusted up to 10 microg/kg daily) or intermittent filgrastim (starting at 300 microg daily one to three times per week to a maximum of 600 microg daily 7 days weekly) was administered to maintain an ANC between 2 and 10 x 10(9)/l. Patients in the control group received filgrastim if severe neutropenia developed. MAIN OUTCOME MEASURES: Incidence of severe neutropenia (ANC < 0.5 x 10(9)/l) or death, incidence of bacterial and fungal infections, duration of hospitalization and intravenous antibacterial use, and safety. RESULTS: The primary endpoint of severe neutropenia or death was less frequent in patients who received daily (12.8%) or intermittent (8.2%) filgrastim compared with control patients (34.1%; P<0.002 and P<0.0001 for comparison with daily and intermittent groups, respectively). Filgrastim-treated patients developed 31% fewer bacterial infections and 54% fewer severe bacterial infections than control patients, required 26% less hospital days including 45% fewer hospital days for bacterial infections, and needed 28% fewer days of intravenous antibacterials. Filgrastim was not associated with an increase in HIV-1 plasma RNA level in a subset of patients in whom this was measured or any new or unexpected adverse events. CONCLUSION: Filgrastim was safe and effective in preventing severe neutropenia in patients with advanced HIV infection, and may reduce the incidence and duration of bacterial infections, incidence of severe bacterial infections, duration of hospital days for infections, and days of intravenous antibacterial agents.

Acquired Immunodeficiency Syndrome↗

Transient vitreous inflammatory reactions associated with combination antiretroviral therapy in patients with AIDS and cytomegalovirus retinitis.

PURPOSE: To report the observation that a transient vitreous inflammatory reaction may develop in the eyes of patients with acquired immunodeficiency syndrome (AIDS), cytomegalovirus retinitis, and an increased CD4+ T-lymphocyte count during treatment with antiretroviral therapy including a protease inhibitor. METHODS: We reviewed the medical records of eight patients with AIDS and cytomegalovirus retinitis who developed vitreous inflammatory reactions greater than those usually seen with this disease. RESULTS: Vitreous inflammatory reactions obscured the view of the posterior pole in all patients. No iris nodules, synechiae, glaucoma, or cystoid macular edema were observed. Six patients had unilateral cytomegalovirus retinitis, and, in each, the inflammation occurred only in the eye with cytomegalovirus retinitis. The vitreous inflammatory reactions were associated with clinically inactive cytomegalovirus retinitis in six patients, with disease reactivation in one patient, and were present at diagnosis of active disease in one patient. Cytomegalovirus retinitis has not recurred in any of these patients since their episodes of vitreous inflammation. Vitreous inflammation developed in all eight patients after a substantial increase in CD4+ T-lymphocyte counts caused by combination antiretroviral therapy. Five patients had CD4+ T-lymphocyte counts of greater than 100 cells per microl at the time the vitreous inflammatory reaction developed. No other causes of uveitis were found. CONCLUSIONS: Patients with AIDS and cytomegalovirus retinitis may develop transient intraocular inflammation associated with combination antiretroviral therapy. We believe that this inflammation reflects an improved immune response against cytomegalovirus.

AIDS-Related Opportunistic Infections↗

Restoration of cytomegalovirus-specific CD4+ T-lymphocyte responses after ganciclovir and highly active antiretroviral therapy in individuals infected with HIV-1.

Recent studies of subjects infected with human immunodeficiency virus (HIV-1) have produced conflicting results about the extent of reconstitution possible in the CD4+ lymphocyte repertoire after highly active antiretroviral therapy (HAART). The effect of HAART on the incidence of opportunistic infections will probably depend on reconstitution of antigen-specific CD4+ lymphocyte responses to important pathogens, including cytomegalovirus (CMV), the leading cause of blindness in AIDS. Several studies have demonstrated an important role for CD4+ lymphocytes in controlling CMV replication in vitro and in clinical studies. It is now possible to quantitate antigen-specific CD4+ lymphocyte responses by flow cytometry. Using this method, we studied CMV-specific CD4+ lymphocyte responses in individuals infected with HIV-1 with and without a history of active CMV-associated end organ disease (EOD), and in those with quiescent CMV EOD after ganciclovir therapy and HAART. The presence of active CMV-associated EOD strongly correlated with loss of CMV-specific lymphocyte responses (P = 0.0004). In contrast, patients with no history of CMV-associated EOD and most patients with quiescent EOD after HAART demonstrated strong CMV-specific CD4+ lymphocyte responses. These data indicate that the loss of CMV-specific CD4+ lymphocyte responses in individuals infected with HIV-1 who have active CMV EOD may be restored after ganciclovir therapy and HAART, which provides evidence for functional immune reconstitution to an important pathogen.

AIDS-Related Opportunistic Infections↗

Eradication of AIDS-related disseminated mycobacterium avium complex infection after 12 months of antimycobacterial therapy combined with highly active antiretroviral therapy.

To determine if microbiologic cure of AIDS-related disseminated Mycobacterium avium complex (MAC) is possible in patients receiving highly active antiretroviral therapy (HAART), 4 patients with a history of disseminated MAC received >/=12 months of macrolide-based antimycobacterial therapy. All were asymptomatic and had absolute CD4 cell count >100/microL (range, 137-301) and <10,000 copies/mL of human immunodeficiency virus RNA (range, <500-1250). A bone marrow aspirate and peripheral blood were obtained for mycobacterial culture. Follow-up blood cultures were obtained routinely at 4 weeks and every 8 weeks thereafter. All 4 patients had negative bone marrow and blood cultures and then discontinued antimycobacterial therapy. All patients' subsequent cultures remain sterile and all are clinically asymptomatic (range, 8-13 months follow-up). It appears that disseminated MAC infection can be cured by prolonged antimycobacterial therapy in some persons who experience sustained CD4 lymphocyte increases while receiving HAART.

AIDS-Related Opportunistic Infections↗

A randomized, double-blind trial of valaciclovir prophylaxis for cytomegalovirus disease in patients with advanced human immunodeficiency virus infection. AIDS Clinical Trials Group Protocol 204/Glaxo Wellcome 123-014 International CMV Prophylaxis Study Group.

Cytomegalovirus (CMV) disease is a common complication of advanced human immunodeficiency virus (HIV) infection. Administration of oral valaciclovir, a valine ester of acyclovir, achieves sufficient plasma acyclovir levels to inhibit many clinical isolates. Acyclovir has been associated with enhanced survival in AIDS but not with CMV disease prevention. CMV-seropositive patients (1227) with CD4 cell counts <100/mm3 were enrolled in a randomized, double-blind trial. Valaciclovir, 8 g/day, was compared with acyclovir, 3.2 or 0.8 g/day, for CMV prevention; all three arms were compared for survival. The confirmed CMV disease rate was 11.7% among valaciclovir recipients and 17.5% in the pooled acyclovir arms, a 33% reduction in risk. Time to confirmed CMV disease was significantly longer for the valaciclovir group (P = .03). A trend toward earlier mortality for valaciclovir recipients was seen (P = .06). Toxicity and earlier medication discontinuation were more common in this group. Valaciclovir significantly reduces the risk of CMV disease. Further exploration of a better-tolerated dose is warranted.

AIDS-Related Opportunistic Infections↗

AIDS-related cytomegalovirus retinitis.

Until recently, chronic daily intravenous infusions of ganciclovir or foscarnet were the only available treatment regimens for cytomegalovirus (CMV) retinitis, a sight-threatening complication that has historically affected approximately one-third of all AIDS patients in industrialized countries. In recent years, results of many randomized clinical trials of new treatments for AIDS-related CMV retinitis have been disseminated. These trials have involved four novel treatment modalities (i.e., an oral formulation of ganciclovir, a ganciclovir intraocular device, a combined intravenous ganciclovir/foscarnet regimen and a new agent, cidofovir) that offer better efficacy and/or less inconvenience than standard daily intravenous therapy with either ganciclovir or foscarnet. This review summarizes the main points clinicians should know about the available treatments for CMV disease.

Journal Article↗

Cloning and expression of the rhesus monkey oxytocin receptor.

The oxytocin receptor belongs to the family of G-protein-coupled receptors (GPCRs) characterized by seven transmembrane spanning domains and mediates numerous neurotransmitter and hormonal functions. The cloning of this receptor was initiated to validate the use of the rhesus monkey (Macaca mulatta) as a viable animal model for therapeutic development of oxytocin receptor antagonists by ruling out potential species variations that are sometimes present among GPCRs. The rhesus monkey oxytocin receptor was cloned by the polymerase chain reaction (PCR) and expressed transiently in 293/EBNA cells. The cDNA encodes a protein of 389 amino acids and is highly homologous to that from other species, especially the human receptor which exhibits 97% identity to the rhesus protein. The cloned receptor shows a very similar pharmacological profile to the human oxytocin receptor for a variety of agonists and antagonists from various structural classes. These results substantiate the validity of the rhesus monkey as a useful model for the evaluation of human therapeutics.

Amino Acid Sequence↗

Altered natural history of AIDS-related opportunistic infections in the era of potent combination antiretroviral therapy.

Since potent HIV protease inhibitor drugs became widely available in early 1996, many HIV clinical specialists have noted a marked decrease in the occurrence of AIDS-related opportunistic infections, and some specialists have reported unusual clinical presentations and manifestations of previously common opportunistic infections. In this article, we will review (1) the available data regarding recent trends in AIDS-related opportunistic infections incidence and manifestations, (2) clinical and immunologic evidence that potent combination antiretroviral therapy can alter the natural history of these opportunistic infections, and (3) the implications of these findings for current patient management practice and future clinical and immunologic research. As a preface to this review, however, it is important to acknowledge that any evaluation of the potential benefit of potent combination antiretroviral therapy in reducing the risk of serious opportunistic infections can be confounded by the concomitant use of prophylactic antimicrobial agents co-administered to prevent specific opportunistic infections. For example, it is standard clinical practice to administer trimethoprim-sulfamethoxazole (or another agent if trimethoprim-sulfamethoxazole cannot be tolerated) to patients with an absolute CD4 lymphocyte count < 200 cells/microliters, unexplained chronic fever or a history of oropharyngeal candidiasis. Similarly, specific antimicrobial prophylaxis to prevent disseminated Mycobacterium avium complex (MAC) infection in patients with absolute CD4 counts < 50 cells/microliters is also a widely recommended guideline. Although the relative efficacies of specific antimicrobial prophylaxis regimens in preventing the most common life- and sight-threatening opportunistic infectious complications of AIDS [Pneumocystis carinii pneumonia (PCP), disseminated MAC infection, and cytomegalovirus (CMV) retinitis] are now well established, these relative efficacies were established in the era before potent combination antiretroviral therapies became available and may not be generalizable to the current era. Nevertheless, for perspective, the reported efficacies of prophylaxis for PCP, disseminated MAC infection, and CMV end-organ disease are summarized in Table 1.

AIDS-Related Opportunistic Infections↗

Human immunodeficiency virus disease-related neutropenia and the risk of hospitalization for bacterial infection.

BACKGROUND: Neutropenia is common in patients with human immunodeficiency virus (HIV) disease. However, the degree of risk for serious bacterial infections associated with various levels of neutropenia in patients with HIV disease is not well defined. METHODS: A retrospective analysis of databases containing demographic information for patients attending the San Francisco General Hospital HIV outpatient clinic, test results reported by the hospital's clinical laboratory, and the San Francisco General Hospital inpatient International Classification of Diseases, Ninth Revision (ICD-9) hospital discharge diagnosis codes from October 1, 1992, through November 30, 1993. Risk window time periods were defined, encompassing dates that consecutive absolute neutrophil counts (ANCs) occurred in a single ANC stratum. One risk window at the lowest ANC stratum for each patient was analyzed for hospitalizations with ICD-9 codes indicating bacterial infections. A 5% random sample of medical records was reviewed for end point validation. RESULTS: Codes from ICD-9 had 98% and 96% positive and negative predictive values, respectively, for meeting National Institute of Allergy and Infectious Diseases Division of AIDS [acquired immunodeficiency syndrome] clinical trial end point definitions for bacterial infections. Among 2047 evaluable patients, a significant increase in the incidence of hospitalization for serious bacterial infections was observed for those in the ANC strata of 500 to 749 X 10(6)/L and below. The 95% confidence intervals for the incidence of hospitalization associated with each ANC stratum below 500 X 10(6)/L did not overlap with that for any stratum of 750 X 10(6)/L or higher (22-117 vs 0.4-19 patient hospitalizations per 10000 days at risk, respectively). A multivariate analysis revealed only the severity and duration of neutropenia and black race to be significant end point predictors. CONCLUSION: Among 2047 patients with HIV disease, significantly higher risks of hospitalization for bacterial infections were associated with ANCs lower than 750 X 10(6)/L, especially for ANCs lower than 500 X 10(6)/L.

AIDS-Related Opportunistic Infections↗

Cytomegalovirus retinitis after initiation of highly active antiretroviral therapy.

BACKGROUND: In previous natural history studies and clinical trials, AIDS-related cytomegalovirus (CMV) retinitis has occurred primarily in patients with absolute CD4 counts of 50 cells/microL or less (0.05 x 10(9)/L) at the time of diagnosis. METHODS: We report five patients identified from our clinical practices who were diagnosed with CMV retinitis while their CD4 counts were above 195 cells/microL. We also analysed, based on CD4 counts, 76 AIDS patients with newly diagnosed CMV retinitis whose CD4 lymphocyte enumerations were done in laboratories that maintained certification in a common external quality control programme. FINDINGS: 5-24 weeks before retinitis was diagnosed, all five patients had had absolute CD4 lymphocyte counts of less than 85 cells/microL, and 4-7 weeks before diagnosis, all five patients had started taking highly active antiretroviral treatment (HAART) regimens. Only one (4%) of 27 patients enrolled in the trial between July, 1995, and February, 1996, had an absolute CD4 count of more than 50 cells/microL, and none of 27 had an absolute CD4 count of more than 100/microL on entry to the trial. However, from March, 1996 (when indinavir and ritonavir were approved by the FDA for marketing in the USA), to August, 1996, 14 (29%) of 49 patients had CD4 counts of more than 50/microL and seven (14%) of 49 had a CD4 count of more than 100 cells/microL on entry. INTERPRETATION: These findings suggest that the early immunological effects of HAART may not provide sufficient protection to prevent CMV retinitis in patients who have very low CD4 counts when therapy is started. Clinicians should note that CMV retinitis may now occur in patients who have CD4 counts of more than 100 cells/microL.

AIDS-Related Opportunistic Infections↗

Adenosine A2a receptor activation delays apoptosis in human neutrophils.

Adenosine has both pro- and anti-inflammatory effects on neutrophils. Exposure of cultured neutrophils to 2-chloroadenosine or 5'-N-ethylcarboxamidoadenosine (NECA) decreased apoptosis after 16 h, with half-maximal responses for NECA and 2-chloroadenosine of 7.1 +/- 7.7 and 59.0 +/- 32.0 nM, respectively. Adenosine receptor agonists exhibited a rank order of potency for decreasing apoptosis of 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamidoadenosine (CGS 21680) > NECA > or = 2-chloro-N6-cyclopentyladenosine >> 2-chloro-N6-(3-iodobenzyl)adenosine-5'-N-methyluronamide, which is consistent with the affinity order profile established for human A2a receptors. The reduction in apoptosis in cultured neutrophils at 16 h by CGS 21680 was due to a delay in apoptosis. The addition of CGS 21680 (100 nM) increased the half-life for the appearance of apoptosis from 10.9 +/- 3.1 to 21.0 +/- 1.0 h. Addition of the non-xanthine phosphodiesterase inhibitor 4-(3-butoxy-4-methoxybenzyl)-2-imidazalidinone (Ro-20-1724; 1 microM) enhanced the effects of CGS 21680 at all agonist concentrations. PGE1 (10 microM), PGE2 (0.1-10 microM), and dibutyryl cAMP (5-500 microM) all decreased apoptosis in cultured neutrophils. The enhancement of the effect of adenosine by a phosphodiesterase inhibitor and the similar actions of PGE2, PGE1, and dibutyryl cAMP suggest that this decrease in apoptosis may be mediated by a cAMP-dependent pathway.

Adenosine↗

Adenosine A3 receptor expression and function in eosinophils.

The A3 adenosine receptor is widely expressed in human tissues with the most abundant expression in the lung and liver, but the predominant cellular localization and functions of this receptor in humans are unknown. Since adenosine influences the activation of circulating and resident inflammatory cells within the lung and leads to exaggerated airway narrowing in individuals with inflammatory airway disorders, we hypothesized that A3 receptor gene expression is localized to inflammatory cells and that gene expression is upregulated in airway inflammation. Lung and airway tissue were obtained at thoracotomy from nonsmoking subjects and subjects with inflammatory airway disorders associated with tobacco smoke or asthma. In situ hybridization identified A3 receptors in mesenchymal cells and eosinophils within the lamina propria of the airways and the adventitia of blood vessels, but not in mast cells. A3 receptor transcripts were highly expressed in peripheral blood eosinophils purified from atopic donors (6.36 +/- 0.60 pg/microg total RNA) in comparison with neutrophils (0.26 +/- 0.06 pg/microg) or mononuclear cells (0.9 +/- 0.15 pg/microg). Mean A3 receptor transcript abundance was greater in lung tissue from subjects with airway inflammation (0.33 +/- 0.04 pg/microg total RNA) than in normal lung (0.24 +/- 0.03 pg/microg total RNA, P = 0.035). The A3 receptor agonist N6-(4-amino-3-iodobenzyl)adenosine dose-dependently inhibited platelet activating factor-induced eosinophil chemotaxis to a maximum of 41%. This inhibitory effect was completely abolished by addition of the A3 receptor selective antagonist 3-(3-iodo-4-aminobenzyl)-8-(4-oxyacetate)phenyl-1-propylxanthine. We conclude that A3 receptors are primarily expressed on eosinophils in human lung, where they mediate inhibition of eosinophil chemotaxis. Specific A3 receptor ligands may be useful agents in the treatment of eosinophil-dependent diseases such as asthma and rhinitis.

Adenosine↗

AIDS-related disseminated histoplasmosis in San Francisco, California.

The published reports of patients with the acquired immunodeficiency syndrome (AIDS) with disseminated histoplasmosis come mostly from institutions located in endemic areas for histoplasmosis, where disease is thought to occur by either primary infection or reactivation. The characteristics of reactivation disease are not well delineated. We describe the clinical features of reactivation disseminated histoplasmosis in 46 residents of San Francisco, California, with AIDS who did not report recent travel to an area endemic for histoplasmosis. Patients presented with illness lasting days to months, manifested most frequently by fever, chills, sweats, cough or dyspnea, gastrointestinal complaints, malaise, and weight loss. Physical examination and imaging studies were notable for hepatosplenomegaly, lymphadenopathy, or abnormal pulmonary findings in more than half of patients. Laboratory studies revealed a high rate of cytopenia, elevated serum lactate dehydrogenase levels, abnormal liver function test values, respiratory alkalosis with hypoxemia, and a median CD4 lymphocyte count of 36 x 10(9) per liter. The clinical presentation of reactivation disseminated histoplasmosis in patients with AIDS living in San Francisco is similar to that of disseminated histoplasmosis reported in patients with AIDS living in endemic areas. Reactivation disseminated histoplasmosis should be considered in any AIDS patient with a low CD4 lymphocyte count, a febrile illness, and a history of travel or residence in an endemic area.

AIDS-Related Opportunistic Infections↗