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Biomedical subjects

J Fleischmann

Publications and source records attributed to J Fleischmann.

At least 19 recordsLinked to original sources

Identification of a gp63 surface glycoprotein in Leishmania tarentolae.

The promastigote stage of most if not all Leishmania species possesses an abundant surface glycoprotein of 63 kDa (gp63) that has protease activity. We show that the lizard parasite Leishmania tarentolae appears to lack the surface protease activity. L. tarentolae does, however, possess an approximately 63-kDa molecule that is antigenically cross-reactive with the L. major gp63. Additionally, the genome of L. tarentolae contains sequences that hybridise at high stringency to a L. major gp63 gene probe.

Animals

Marketing CT and MR imaging services in a large urban teaching hospital.

A three-phase marketing program was implemented to increase referrals for examination with computed tomographic (CT) or magnetic resonance (MR) imaging and improve services in an academic radiology department. In the research phase, a data base of 135 referring physicians was developed, and a questionnaire was mailed to 130 physicians. The market research identified three key issues: waiting time to get an appointment, scheduling procedures, and communication of findings. In the implementation phase, additional equipment was installed and a program of expanded appointments, service improvements, and public relations was introduced. In the evaluation phase, 1 year after the completion of phase 2, the effect of the marketing program was measured. The average number of physicians who made referrals per month increased from 609 to 653 (an increase of 7.2% over baseline); the average number of CT and MR examinations performed each month increased by 57.3% and 45.2%, respectively. Referrers' ratings of 10 imaging services improved significantly (P = .02). It is concluded that a well-designed marketing program can boost the productivity of a teaching hospital department.

Appointments and Schedules

Benign fibrous tumor of the tunica vaginalis testis. Report of a case with light, electron microscopic, and immunocytochemical study, and review of the literature.

Benign fibrous tumor of the tunica vaginalis testis is an uncommon lesion of unknown pathogenesis and histogenesis, frequently described as fibrous pseudotumor. We describe a case of a fibrous tumor of the tunica vaginalis testis studied with light, immunocytochemical, and electron microscopy in a 64-year-old man who also developed a metachronous renal cell carcinoma. To our knowledge, this is the first such case to be presented. We describe the cell of origin of this rare entity and its similarity to fibrous tumors of pleura and extrapleural sites, with a review of the English-language literature and emphasize that not all intrascrotal tumors are malignant.

Fibroma

Human immunodeficiency virus causes mononuclear phagocyte dysfunction.

There is compelling clinical evidence for dysfunction of the mononuclear phagocyte system in patients with AIDS, which is believed due in part to loss of T-cell cooperativity. The direct consequences of human immunodeficiency virus infection on macrophage function are unknown. To address this question we infected normal human macrophages in vitro with a monocytotropic strain of human immunodeficiency virus and performed assays to quantify their extra- and intracellular killing ability. Human immunodeficiency virus-infected macrophages were significantly less effective than control cells in mediating antibody-dependent cell-mediated cytotoxicity against leukemic cell targets and intracellular killing of Candida pseudotropicalis. The functional defects were profound, related temporarily to active virus production by the macrophages, and could not be overcome by granulocyte-macrophage colony-stimulating factor. Treatment of macrophages with 3'-azido-3'-deoxythymidine (AZT) 6 days after infection caused a marked decrease in virus production and prevented development of the intracellular killing functional defect. The results suggest that early antiviral therapy may be useful in preventing or mitigating some virus-induced mononuclear phagocyte dysfunction.

Antibody-Dependent Cell Cytotoxicity

The intracellular fate of Histoplasma capsulatum in human macrophages is unaffected by recombinant human interferon-gamma.

Human alveolar, peritoneal, and cultured macrophages were exposed in vitro to human recombinant interferon-gamma (rHuIFN-gamma) and were tested for their ability to inhibit intracellular replication of yeast-phase Histoplasma capsulatum. Exposure at various concentrations, and for different time periods, failed to activate the macrophages to inhibit multiplication of intracellular yeast. Macrophages were, however, activated by rHuIFN-gamma as shown by their ability to inhibit intracellular replication of Trypanosoma cruzi and by their enhanced production of superoxide when stimulated by phorbol myristate acetate. These data indicate that rHuIFN-gamma by itself does not activate human macrophages to inhibit intracellular proliferation of yeast-phase H. capsulatum.

Cells, Cultured

Seasonal rhythm of platelet 3H-imipramine binding in normal controls.

The densities of platelet 3H-imipramine sites were determined by repetitive measures of 11 normal controls over the course of 1 year. A significant seasonal variation was found, with a circannual peak on February 17 and a nadir on August 18. The estimated amplitude of this rhythm was +/- 599.54 fmol/mg, which fluctuated about a yearly mean of 2647.5 fmol/mg. The present results underscore the importance of including seasonally matched controls in the evaluation of potential patient differences in platelet binding.

Adult

Biologic response modifiers and urologic malignancies.

Biologic response modifiers represent a new generation of immunotherapeutic agents. Although biologic response modifiers such as interferon have been moderately successful in treating B-cell malignancies, they have not been as successful for the management of advanced genitourinary malignancies. The measurement of biologic response modifiers in the urine may prove useful for directing intravesical BCG therapy for the treatment of superficial bladder cancer or for directing the use of prophylactic antibiotics for the management of urinary tract infections.

BCG Vaccine

Granulocyte-macrophage colony-stimulating factor enhances neutrophil function in acquired immunodeficiency syndrome patients.

We conducted a clinical trial of human recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) in leukopenic patients with acquired immunodeficiency syndrome (AIDS) and analyzed neutrophil function before, during, and after in vivo administration of rGM-CSF. Prior to GM-CSF infusion, AIDS patients' neutrophil superoxide generation and neutrophil antibody-dependent cell-mediated cytotoxicity were enhanced normally by in vitro exposure to GM-CSF. Neutrophil phagocytosis and intracellular killing of Staphylococcus aureus were also normal in the majority of these patients. Two patients, however, had discrete neutrophil functional defects: one in phagocytosis and one in intracellular killing. During the period of GM-CSF infusion, these abnormalities were corrected. The number of circulating neutrophils increased in all patients treated with GM-CSF in a dose-dependent manner. Neutrophils produced in vivo in response to GM-CSF administration functioned normally and there was evidence for neutrophil priming and activation in vivo. We conclude that GM-CSF treatment of AIDS patients leads to the production of functionally active neutrophils, suggesting therapeutic potential for GM-CSF in the treatment of patients with impaired host defense.

Acquired Immunodeficiency Syndrome

Clinicopathologic correlation of lipidization and detachment of the retinal pigment epithelium.

A 49-year-old woman had a few small drusen-like lesions and one larger area of depigmentation in the right fundus. The pin-point lesions corresponded to single enlarged retinal pigment epithelial cells with lipid accumulation and the larger area represented a small, localized retinal pigment epithelial detachment (soft druse). Lipoidal degeneration of individual retinal pigment epithelial cells may be a mechanism of nodular drusen formation. The soft druse was associated with thickening of the basement membrane of the retinal pigment epithelium.

Female

Primary Candida meningitis and chronic granulomatous disease.

The occurrence of two rare entities in a single patient can be fortuitous or may signify some deeper relationship. A young boy was recently treated for primary Candida meningitis. Autopsy findings suggested to an experienced pathologist the presence of chronic granulomatous disease (CGD), unrecognized during his life. The patient's identical twin brother was tested and found to have the typical laboratory features of CGD. The literature on Candida meningitis was reviewed and 15 cases were discovered that apparently arose in the absence of recognized predisposing causes. All but one of these cases occurred in males, and most occurred during the first three decades of life. The case reports and literature review presented herein suggest that CGD should be suspected when a case of "primary" Candida meningitis is encountered.

Candidiasis

Granulocyte-macrophage colony-stimulating factor enhances phagocytosis of bacteria by human neutrophils.

In order to determine whether human granulocyte-macrophage colony-stimulating factor (GM-CSF) can enhance phagocytosis, neutrophils were combined with Staphylococcus aureus (S aureus), and both the number of bacteria per neutrophil and the percent of neutrophils phagocytizing were assessed in the absence and presence of GM-CSF. Exposure to GM-CSF did not enable neutrophils to ingest unopsonized bacteria. When bacteria were opsonized with serum, both the number of bacteria per neutrophil and the percent of cells phagocytizing were increased by treatment with GM-CSF. Digestion of extracellular organisms by lysostaphin was used to substantiate phagocytosis. These results indicate that another effect of GM-CSF on the mature neutrophil is the enhancement of phagocytosis.

Blood Bactericidal Activity

Opsonic activity of MCP-1 and MCP-2, cationic peptides from rabbit alveolar macrophages.

MCP-1 and MCP-2, cationic peptides derived from rabbit alveolar macrophages, enhanced the ability of these cells to ingest Staphylococcus aureus, Klebsiella pneumoniae, Bordetella bronchiseptica, and Candida albicans in vitro. The opsonic effect of MCP-1 was potentiated by Ca++ and Mg++ and was associated with binding of the peptide to alveolar macrophages and microorganisms. MCP-1 and MCP-2 may contribute to the ability of alveolar macrophage to ingest microorganisms that gain entry to the lower respiratory tract.

Animals