Assuntos
Síndrome da Alça Aferente/diagnóstico por imagem , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/cirurgia , Síndrome da Alça Aferente/cirurgia , Idoso , Gastrectomia/métodos , Gastroenterostomia/efeitos adversos , Humanos , Masculino , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/cirurgia , Tomografia Computadorizada por Raios XRESUMO
The mechanism by which heparin and antithrombotic agents, including a cyclic octaphenolsulfonic acid (compound Y), stimulate the synthesis of an antithrombotic heparan sulfate by endothelial cells in culture was investigated. Compound Y increases the amount of heparan sulfate from the cell surface and secreted to the medium by endothelial cells by three-fold. Binding experiments have shown saturation of the endothelial cell receptors at a concentration of 0.16 microM for heparin and 2.7 microM for compound Y. The kinetic binding constants (Ks) for compound Y and heparin were 1,333 nM and 42 nM, respectively. It was also shown that both compounds bind to the same receptors. The Scatchard plots indicated that 1,319 nmoles compound Y and 35 nmoles heparin bound per microgram cell protein, indicating that 40-fold more molecules of compound Y bound to the receptors when compared to heparin. No significant internalization of the compounds was observed.
Assuntos
Endotélio Vascular/metabolismo , Heparina/metabolismo , Heparitina Sulfato/biossíntese , Proteoglicanas/biossíntese , Ácidos Sulfônicos/metabolismo , Animais , Células Cultivadas , Endotélio Vascular/citologia , Cobaias , Proteoglicanas de Heparan Sulfato , Ligação Proteica , Coelhos , Fatores de TempoRESUMO
The mechanism by which heparin and antithrombotic agents, including a cyclic octaphenolsufonic acid (compound Y), stimulate the synthesis of an antithrombotic heparan sulfate by endothelial cells in culture was investigated. Compound Y increases the amount of heparan sulfate from the cell surface and secreted to the endothelial cell receptors at a concentration of 0.16µM for heparin and 2.7µM for compound Y. The kinetic binding constants (Ks) for compound Y and heparin were 1,333 nM and 42 nM, respectively. It was also shown that both compounds bind to the same receptors. The Scatchard plots indicated that 1,319 nmoles compound Y and 35 nmoles heparin bound per microgram cell protein, indicating that 40-fold more molecules of compound Y bound to the receptors when compared to heparin. No significant internalization of the compounds was observed
Assuntos
Cobaias , Coelhos , Animais , Endotélio Vascular/metabolismo , Heparina/farmacologia , Heparitina Sulfato/biossíntese , Proteoglicanas/biossíntese , Linhagem Celular , Células Cultivadas , Endotélio Vascular/citologia , Temperatura Alta , Ligação Proteica , Fatores de TempoRESUMO
OBJECTIVES: To elucidate the epidemiology of widespread ciprofloxacin resistance in our Veterans Affairs medical center using whole cell DNA analysis. DESIGN: In vitro study of ciprofloxacin resistant and susceptible Enterobacteriaceae isolated during the course of a clinical epidemiologic study of quinolone resistance. SETTING: Veterans Affairs Medical Center with acute care and long-term care divisions. RESULTS: We examined 40 ciprofloxacin-resistant strains of Serratia marcescens, Proteus mirabilis, and Providencia stuartii using restriction endonuclease analysis of whole cell DNA and compared them with concomitantly isolated ciprofloxacin sensitive strains. We sought to determine whether resistant strains were identical to susceptible strains, indicating in vivo emergence of resistant strains from susceptible strains, and whether resistant strains were shared among patients. All 26 ciprofloxacin-resistant S marcescens isolates shared a single ecoRI restriction pattern. Multiple patterns were seen in the ciprofloxacin-susceptible S marcescens isolates; however, several isolates had a pattern matching that of the resistant isolates. Similar results were seen among the P mirabilis isolates. Three different ecoRI patterns were found among the ciprofloxacin-resistant P stuartii isolates; none matched those found among the susceptible isolates. The frequency of spontaneous emergence of ciprofloxacin resistance in susceptible S marcescens strains with restriction pattern matching that of the resistant strains was significantly higher than that of nonmatching strains. CONCLUSIONS: Ciprofloxacin-resistant strains of Enterobacteriaceae became widespread within a short period of time. Resistant strains of S marcescens and P mirabilis arose from endemic susceptible strains. The resistant strain of S marcescens appeared to arise from a susceptible strain with a relatively high frequency of spontaneous ciprofloxacin resistance.
Assuntos
Ciprofloxacina/farmacologia , DNA Bacteriano/genética , Enterobacteriaceae/efeitos dos fármacos , Estudos de Casos e Controles , Enzimas de Restrição do DNA/genética , Resistência Microbiana a Medicamentos , Enterobacteriaceae/genética , Hospitais de Veteranos , Humanos , Testes de Sensibilidade Microbiana , Serratia marcescens/efeitos dos fármacos , Serratia marcescens/genéticaRESUMO
Although cases of community-acquired Legionnaires' disease have been epidemiologically linked to residential water supplies, the risk of acquiring Legionnaires' disease from exposure to Legionella pneumophila in residential water systems is uncertain. The residential water supplies of 218 members of the American Legion in six different geographical areas in Pittsburgh were cultured for L. pneumophila. Residents of the homes provided a recent medical history and a blood sample for detection of antibodies to legionella. A urine sample for legionella urinary antigen testing was also requested from individuals residing in legionella-positive homes and individuals with a positive antibody test. Six percent (14/218) of the homes yielded L. pneumophila (range within six areas 0-22%). Lower hot water tank temperature was significantly associated with legionella positivity (P less than 0.01). Analysis of water samples for mineral content showed no association between legionella positivity and concentrations of calcium and magnesium. Water samples from the area where 22% of the homes surveyed were positive for legionella had a higher iron content than water samples from the other areas tested. None of the individuals residing in legionella-positive homes showed elevated antibody titres to legionella or the presence of legionella antigen in urine. For the immunocompetent hosts, the risk of contracting Legionnaires' disease from exposure to contaminated household water supplies in the Pittsburgh area appears to be low.
Assuntos
Legionella pneumophila/isolamento & purificação , Doença dos Legionários/epidemiologia , Microbiologia da Água , Abastecimento de Água , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/urina , Temperatura Alta , Humanos , Legionella pneumophila/imunologia , Pessoa de Meia-Idade , Minerais/análise , Análise Multivariada , Prevalência , Abastecimento de Água/análiseRESUMO
A sanitary microbiological survey of fresh and processed fish on sale in Guatemalan markets and supermarkets was carried out. Samples of tables, floor and freezer surfaces, and of the water, ice and liquid drippings of the different stands were also taken and analyzed. Aerobic counts exceeded 10(6)/g in 72% of the samples, and 16% had more than 40 fecal coliforms/g. Coagulase-positive Staphylococcus aureus were never higher than 100/g in fish. The bacterial counts were higher in the ice and liquid drippings.