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Biomedical subjects

R Fox

Publications and source records attributed to R Fox.

At least 163 records · Page 9Linked to original sources
PubMed1994

Identification, localization, and distribution of the PilT protein in Neisseria gonorrhoeae.

A monoclonal antibody (MAb) directed against a highly conserved protein of Neisseria gonorrhoeae with a molecular size of 40 kDa was isolated and characterized. The protein antigen detected by this MAb was detected by enzyme-linked immunosorbent assay and immunoblotting in all strains of N. gonorrhoeae tested across a wide range of serovars. The 40-kDa protein was found to be expressed at relatively low levels and localized to both the cytosolic and cytoplasmic membrane fractions. Screening of a lambda gt11 expression library derived from gonococcal genomic DNA with the anti-40-kDa MAb and DNA sequence analysis suggested that the 40-kDa protein and the product of the gonococcal pilT gene were identical. Immunoblotting analysis of gonococcal mutants carrying defined mutations in the pilT gene confirmed that the 40-kDa protein was indeed PilT. The N-terminal sequence derived by microsequencing of the protein purified from gonococci led to the correction of the previously published pilT gene sequence. Sequencing of the pilT gene from three different strains revealed an extremely high degree of conservation at both the amino acid and DNA levels.

Adenosine Triphosphatases↗
PubMed1993

Ultrasound diagnosis of polycystic ovaries.

Ultrasound characterization of ovarian morphology has become an important aspect of gynecological endocrinology. The classic ultrasound features of polycystic ovaries are an increased number of small follicles together with abundant stroma. The exact criteria vary according to the ultrasound technique used. The method, however, has been validated both laparoscopically and histologically. Using laparoscopic inspection as a reference test, ultrasonography was calculated to have a sensitivity of 91% and a specificity of 100%. As a group, anovulatory women with PCO have the classic endocrine features of polycystic ovarian syndrome, but in a proportion of cases the finding of PCO at scan appears to be irrelevant to the presenting disorder. Ultrasound diagnosis of PCO is also limited by its inability to display either ovary in about 16% of women.

Female↗
PubMed1993

Early bactericidal and sterilizing activities of ciprofloxacin in pulmonary tuberculosis.

The early bactericidal and sterilizing activities of ciprofloxacin were evaluated in the treatment of adult patients with smear positive pulmonary tuberculosis. Two randomized prospective studies were performed in Northern Tanzania. In study 1, ten patients received either 750 mg ciprofloxacin or 300 ng isoniazid daily for 7 days. Counts of colony-forming units (cfu) of Mycobacterium tuberculosis in early morning sputum were performed. In study 2, twenty patients received either a standard regimen of rifampin (R), isoniazid (H), pyrazinamide (Z), and ethambutol (E) (regimen HRZE) or a trial regimen of ciprofloxacin (C), isoniazid (H), and rifampin (R) (regimen HRC). Sputum colony counts were performed for 8 wk. Patients were tested for antibodies to human immunodeficiency virus (HIV)-1. The results demonstrate that ciprofloxacin alone has useful early bactericidal activity, resulting in a mean daily fall of 0.20 log10cfu/ml/day during 7 days compared with 0.25 log10cfu/ml/day for isoniazid. When HRZE and HRC regimens were compared, the HRC regimen appeared to be inferior in its sterilizing ability, with a culture conversion rate of 67% at 2 months compared with 100% for HRZE. The difference in outcome was most marked in HIV-1 positive patients. The role of ciprofloxacin in combination regimens may be as a bactericidal rather than a sterilizing agent.

Adult↗
PubMed1993

Paederus (Nairobi fly) vesicular dermatitis in Tanzania.

Four cases of dermatitis following contact with insects of the genus Paederus are described. The insects are known in East Africa as Nairobi fly and cause an acute, painful toxic epidermolysis when crushed on skin. Local clinicians are familiar with the condition, but it should also be borne in mind as a cause of unusual skin lesions in visitors returning from East Africa.

Adult↗
PubMed1993

The effect of parenteral lipid emulsion-induced hyperlipidemia on prostaglandin E1 modulation of platelet function.

The purpose of this study is to better understand how hyperlipidemia alters the modulating action of prostaglandin E1 (PGE1) on platelet function. Using our previously characterized rat model of atherogenesis, we demonstrate that the parenteral lipid emulsions, Lipofundin-S and Liposyn, significantly (p < or = 0.05) enhance baseline platelet aggregation. In addition, dose response curves show that in all animals, PGE1 substantially inhibits platelet aggregation at 10(-7) to 10(-6) M, while significantly stimulating platelet function at lower doses. However, at all PGE1 concentrations, aggregation values are higher in platelets from lipid-treated vs. control rats, showing that hyperlipidemia significantly reduces the ability of high concentrations of PGE1 to inhibit platelet activity, based on the absolute values of the controls. Also, dose response curves for PGE1 on platelet aggregation show a marked similarity in shape for control ratsvs. normal humans. Thus, this study demonstrates that hyperlipidemia significantly alters the platelet modulating action of prostaglandin E1, and it shows that PGE1 can either inhibit or stimulate platelet activity in both rat and human platelets.

Adenosine Diphosphate↗
PubMed1992

Predictors of the risk of development of acquired immunodeficiency syndrome within 24 months among gay men seropositive for human immunodeficiency virus type 1: a report from the Multicenter AIDS Cohort Study.

The natural history of infection with human immunodeficiency virus type 1 (HIV-1) is characterized by a relentless decline in CD4-positive lymphocytes and the ultimate development of acquired immunodeficiency syndrome (AIDS). However, variables other than the CD4-positive lymphocyte level contribute to the measurement of risk for AIDS and can be used as predictors of AIDS onset. This study was undertaken to identify factors that, independently of the CD4-positive lymphocyte level, would predict the risk of AIDS over 24 months in a cohort of HIV-1 seropositive homosexual men receiving no antiretroviral therapy. Demographic, clinical, and laboratory data from 1,325 white, HIV-1 seropositive participants in the Multicenter AIDS Cohort Study who have been studied for 4 years were analyzed with univariate and multivariate methods. To control for stage of infection, the baseline percentage of CD4-positive lymphocytes (a known marker of disease progression), and the decline of CD4-positive cells during the first 6 months of observation were used as continuous variables. The variables that were independently associated with an increased risk of developing AIDS were: low baseline CD4 percentage, decline in the CD4 percentage during the first 6 months of follow-up, the presence of serum immunoglobulin A at baseline, decrease in hemoglobin during the first 6 months of follow-up, incident fatigue, and the interaction of decline in the CD4 percentage and incident thrush. While low CD4 percentage and other variables have been previously described as prognostic markers, decline in the CD4 percentage and the interaction of that decline and incident thrush have not previously been described as being of prognostic importance. These variables and the analytic method for estimating prognosis may prove useful for selecting and evaluating antiretroviral therapy, instituting prophylactic measures against certain opportunistic infections, and recruitment into clinical trials. Because study participants received no antiretroviral prophylaxis during the period under analysis, the method could be used to estimate the prognosis for those receiving investigational treatment were they to remain untreated, effectively making any participant in a clinical trial his own untreated control.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Effect of HIV posttest counseling on STD incidence.

OBJECTIVE: To evaluate the effectiveness of human immunodeficiency virus (HIV) testing and posttest counseling in reducing subsequent high-risk behavior. METHODS: The incidence of sexually transmitted diseases (STDs) in the Baltimore, Md, public STD clinic population after HIV testing and counseling was determined by chart review and was compared in two groups, 868 HIV-seropositive patients and 1104 HIV-seronegative patients, matched by age, sex, and month in which HIV test was conducted. Patients were observed for incident STDs at intervals of 6 through 23 months. Patients with incident STDs were classified hierarchically after being notified of the HIV test result and receiving posttest counseling. RESULTS: Of HIV-seropositive patients, 615 (71%) returned for their test results and received posttest counseling; 694 HIV-seronegative patients (63%) returned. Of all those who returned for results and posttest counseling, 60 (9.7%) of 615 HIV-seropositive patients and 61 (8.8%) of 694 HIV-seronegative patients were diagnosed at least once with definite STD (syphilis, gonorrhea, or trichomoniasis) (P, not significant). Twenty-four HIV-seropositive patients (3.9%) and 71 HIV-seronegative patients (10.2%) returned with probable STD (nongonococcal urethritis or pelvic inflammatory disease) (P less than .001). Nine HIV-seropositive patients (1.5%) and 23 HIV-seronegative patients (3.3%) returned having had an STD-infected sexual partner (P less than .03). Age, sexual orientation, and drug use behavior did not predict return with STD. CONCLUSIONS: Both HIV-seropositive and HIV-seronegative patients showed high rates of repeat STDs after posttest counseling, an important public health challenge in creating effective high-risk behavior prevention strategies.

Counseling↗
PubMed1992

Basic fibroblast growth factor in cells derived from Dupuytren's contracture: synthesis, presence, and implications for treatment of the disease.

Dupuytren's contracture (DC) is associated with fibroblast and endothelial cell proliferation. We have identified a fibroblast and endothelial cell mitogen, basic fibroblast growth factor (FGF), in cells derived from this tissue and characterized the effects of this growth factor on DC cells. Northern blot analysis of DC cells reveals the presence of basic FGF mRNA species, and the DC cells coexpress multiple forms of basic FGF. Radioreceptor assays establish that the DC cells have high-affinity binding sites for basic FGF and proliferate in response to exogenous recombinant basic FGF. Furthermore, a conjugate between saporin (a ribosome-inactivating protein) and basic FGF, which is cytotoxic to cells possessing the basic FGF receptor, is also cytotoxic to DC cells. The possibility that basic FGF-saporin could be a potential therapeutic agent for prevention of recurrence of the disease after surgery is discussed.

Cell Division↗
PubMed1992

Absorption of human calcitonin across the rat colon in vivo.

1. We studied the absorption of human calcitonin across the colon of juvenile female rats in vivo. Both pharmacokinetic and pharmacodynamic parameters were monitored to measure absorption. 2. Intracolonically administered human calcitonin at doses of 0.1-5.0 mg/kg resulted in a dose-dependent reduction in plasma calcium levels. 3. The bioavailability of intracolonically administered human calcitonin at doses of 5.0, 1.0 and 0.1 mg/kg was 0.5%, 0.9% and 0.2%, respectively. 4. Immunohistochemistry showed that human calcitonin transport across the rat colon was rapid and that a significant amount was via a transcellular pathway. 5. We conclude that human calcitonin crosses the gastrointestinal tract of rats in significant amounts and that this demonstrates the feasibility of an oral form for clinical use.

Animals↗