Biomedical subjects

B Foresman

Publications and source records attributed to B Foresman.

6 recordsLinked to original sources

PubMed2000

Type V collagen modulates alloantigen-induced pathology and immunology in the lung.

Perivascular and peribronchiolar tissues are targets of the immune response during lung allograft rejection. Collagen type V (col[V]) is located within these tissues. Col(V) may be major histocompatibility complex (MHC)-like, and MHC-derived peptides have been used to induce immunologic tolerance and prevent rejection in allografts other than the lung. The current study tests the hypothesis that col(V) could be used to downregulate immune responses to lung alloantigen in vivo. We developed a murine model in which instillations of allogeneic bronchoalveolar lavage (BAL) cells (C57BL/6, I-a(b), H-2(b)) into lungs of BALB/c mice (I-a(d), H-2(d)) induce histology similar to grades 1 and 2 acute lung allograft rejection, apoptosis of airway epithelium and vascular endothelium, and upregulate tumor necrosis factor (TNF)-alpha production locally. The current study reports that instillations of col(V) into lungs before allogeneic BAL cells prevent development of rejection pathology and apoptosis, downregulate alloantigen-induced T-lymphocyte proliferation, and abrogate local TNF-alpha production. In addition, instillation of col(V)-pulsed autologous BAL cells into lungs of mice primed with allogeneic BAL cells perpetuates rejection pathology. Collectively, these data show that col(V) is a novel antigen involved in the rejection process, and suggest that col(V) could be used to modulate the rejection response to lung allografts.

Animals↗

PubMed2000

Instillation of allogeneic lung antigen-presenting cells deficient in expression of major histocompatibility complex class I or II antigens have differential effects on local cellular and humoral immunity and on pathology in recipient murine lungs.

Recognition of allogeneic major histocompatibility complex (MHC) molecules expressed on donor lung antigen-presenting cells (APCs) by host T lymphocytes is believed to stimulate lung allograft rejection. However, the specific roles of donor MHC molecules in the rejection response is unknown. We report a murine model in which instilling allogeneic lung APCs into recipient lungs induces pathology analogous to acute rejection, and the production of interferon (IFN)-gamma, immunoglobulin (Ig) G2a, and alloantibodies in recipient lungs. Using allogeneic lung APCs (C57BL/6, I-a(b), H-2(b)) deficient in MHC class I, II, or both for instillation into lungs of BALB/c mice (I-a(d), H-2(d)), the purpose of the current study was to determine the specific roles of donor MHC molecules in stimulating local alloimmune responses. The data show that MHC class I or II on donor APCs induced IFN-gamma and IgG2a synthesis locally, though less than that induced by wild-type cells. Both MHC class I and II were required to induce alloantibody production. Instillation of wild-type or class I- or class II-deficient APCs induced comparable pathologic lesions in recipient lungs, and more severe than that induced by MHC-deficient cells. These data show that donor MHC class I and II molecules have differential effects in the stimulation of local alloimmune responses.

Animals↗

PubMed1999

Universal HIV screening at a major metropolitan TB clinic: HIV prevalence and high-risk behaviors among TB patients.

OBJECTIVES: This study assessed the outcome of implementing a policy of universal screening of patients with tuberculosis (TB) for HIV infection at a major metropolitan public health TB clinic. METHODS: HIV serologic testing was completed on 768 (93%) of 825 eligible patients. Ninety-eight HIV-positive cases (13%) were compared with 670 HIV-negative cases. The presence of adult HIV risk factors was determined by structured interview and review of medical records. RESULTS: One or more HIV risk factors were present in 93% of HIV-positive cases and 42% of HIV-negative cases. CONCLUSIONS: The metropolitan TB clinic is well suited for HIV screening, and HIV-antibody testing and counseling should be provided to all TB patients.

Adolescent↗

PubMed1999

Treatment costs of directly observed therapy and traditional therapy for Mycobacterium tuberculosis: a comparative analysis.

OBJECTIVE: Treatment of tuberculosis is a time-consuming and expensive process, often complicated by patient non-adherence. Directly observed therapy (DOT), an out-patient management strategy designed to ensure adherence, is not widely used because it is perceived to be too expensive. This study compared costs of tuberculosis treatment in DOT to the same factors in traditional therapy. DESIGN: A retrospective economic evaluation of 659 tuberculosis cases was reported to a major metropolitan county public health department between 1980 and 1994. Out-patient costs, in-patient costs and the cost impact of relapse and acquired resistance were estimated in 1995 dollars. RESULTS: Treatment costs were lower with DOT: $15,670 per case for in-patient care and $700 per case for out-patient care (P < 0.001). These cost differences resulted from shorter therapy duration (334 vs 550 days), fewer patient hospitalizations (58 vs 75%) and shorter hospital stays (26 vs 55 days per hospitalized patient). Relapse or acquired resistance occurred in 10.9% of patients and accounted for 35.7% of cost with traditional therapy, as compared to 1.2% of patients and 6.0% of cost with observed therapy. CONCLUSIONS: Directly observed therapy is less costly than traditional therapy.

Adolescent↗

PubMed1994

Chronic sympathectomy of canine cardiac ventricles affects Gs-adenylyl cyclase coupling and muscarinic receptor density.

The effect of chronic ventricular sympathectomy on sarcolemmal muscarinic receptor (MR) and beta-adrenoceptor densities and coupling of these receptors to adenylyl cyclase was examined. Microsomal membranes were isolated from right and left ventricles of control dogs (sham- and nonoperated) and dogs with ventricles sympathectomized 4 weeks earlier. Relative to control membranes, MR density was decreased in left but not right ventricular (LV, RV) membranes from sympathectomized hearts. Relative carbachol inhibition of adenylyl cyclase was similar in RV and LV membranes from both heart groups, however, Although beta-adrenoceptor densities and ratio of beta 1- and beta 2-adrenoceptor subtypes did not change, basal adenylyl cyclase activity was 40% less in sympathectomized membranes as compared with control membranes. Furthermore, relative stimulation of adenylyl cyclase by isoproterenol was twofold greater in sympathectomized heart membranes. Because maximally stimulated adenylyl cyclase activity by NaF or MnCl2 was identical in sympathectomized and control membranes, the reduction in basal activity may not be related to a decrease in Gs and adenylyl cyclase. In support of this hypothesis, Gs alpha content as estimated from optimal cholera toxin-catalyzed ADP-ribosylation was similar in control and sympathectomized membranes. Therefore, an alteration in Gs interaction with adenylyl cyclase may account for the reduction in basal adenylyl cyclase activity and the increased relative responsiveness of adenylyl cyclase to isoproterenol in chronically sympathectomized ventricular membranes.

Adenylyl Cyclases↗

PubMed1991

Oxygen supply and utilization relationships. A reevaluation.

The relationship between oxygen transport (TO2) and oxygen consumption (VO2) has been studied in patients with a number of acute and chronic disorders. Many of these patients have been shown to have a linear relationship between these two variables over a wide range of TO2, which has been considered as evidence of pathologic supply dependency. This supply dependency contrasts with animal studies that have clearly demonstrated a biphasic relationship between TO2 and VO2. This review of the available data concerning the relationship between oxygen transport and supply under conditions of increased oxygen requirements and reduced oxygen transport suggests the possibility that the observed interaction in patients may, in many cases, represent the normal physiologic behavior of the system rather than an abnormal manifestation of impaired oxygen extraction.

Biological Transport↗