RESUMEN
BACKGROUND: Although risk factors for HIV infection are known, it is important for blood centres to understand local epidemiology and disease transmission patterns. Current risk factors for HIV infection in blood donors in Brazil were assessed. METHODS: A case-control study was conducted at large public blood centres located in four major cities between April 2009 and March 2011. Cases were persons whose donations were confirmed positive by enzyme immunoassays followed by Western blot confirmation. Audio computer-assisted structured interviews (ACASI) were completed by all cases and controls. Multivariable logistic regression was used to estimate adjusted odds ratios (AORs) and associated 95% confidence intervals (CIs). RESULTS: There were 341 cases, including 47 with recently acquired infection, and 791 controls. Disclosed risk factors for both females and males were sex with an HIV-positive person AOR 11.3, 95% CI (4.1, 31.7) and being an IVDU or sexual partner of an IVDU [AOR 4.65 (1.8, 11.7)]. For female blood donors, additional risk factors were having male sex partners who also are MSM [AOR 13.5 (3.1, 59.8)] and having unprotected sex with multiple sexual partners [AOR 5.19 (2.1, 12.9)]. The primary risk factor for male blood donors was MSM activity [AOR 21.6 (8.8, 52.9)]. Behaviours associated with recently acquired HIV were being a MSM or sex partner of MSM [13.82, (4.7, 40.3)] and IVDU [11.47, (3.0, 43.2)]. CONCLUSION: Risk factors in blood donors parallel those in the general population in Brazil. Identified risk factors suggest that donor compliance with selection procedures at the participating blood centres is inadequate.
Asunto(s)
Donantes de Sangre , Infecciones por VIH/sangre , Infecciones por VIH/epidemiología , VIH-1 , Auditoría Médica , Adolescente , Brasil/epidemiología , Estudios de Casos y Controles , Femenino , Infecciones por VIH/prevención & control , Humanos , Masculino , Factores de Riesgo , Asunción de Riesgos , Sexo InseguroRESUMEN
Uroguanylin and guanylin are newly discovered endogenous heat-stable peptides that bind to and activate a membrane bound guanylyl cyclase signaling receptor (termed guanylyl cyclase C; GC-C). These peptides are not only found in blood but are secreted into the lumen of the intestine and effect a net secretion of electrolytes (Na+, K+, Cl-, HCO3-) and fluid into the intestine via a cyclic guanosine-3', 5'-monophosphate (cGMP) mechanism. GC-C is also the receptor for Escherichia coli heat-stable enterotoxin (STa) and activation by STa results in a diarrheal illness. Employing mouse renal in vivo models, we have demonstrated that uroguanylin, guanylin, and STa elicit natriuretic, kaliuretic, and diuretic effects. These biological responses are time- and dose-dependent. Maximum natriuretic and kaliuretic effects are observed within 30-40 min following infusion with pharmacological doses of the peptides in a sealed-urethra mouse model. Our mouse renal clearance model confirms these results and shows significant natriuresis following a constant infusion of uroguanylin for 30 min, while the glomerular filtration rate, plasma creatinine, urine osmolality, heart rate, and blood pressure remain constant. These data suggest the peptides act through tubular transport mechanisms. Consistent with a tubular mechanism, messenger RNA-differential display PCR of kidney RNA extracted from vehicle- and uroguanylin-treated mice show the message for the Na+/K+ ATPase gamma-subunit is down-regulated. Interestingly, GC-C knockout mice (Gucy2c -/-) also exhibit significant uroguanylin-induced natriuresis and kaliuresis in vivo, suggesting the presence of an alternate receptor signaling mechanism in the kidney. Thus, uroguanylin and guanylin seem to serve as intestinal and renal natriuretic peptide-hormones influencing salt and water transport in the kidney through GC-C dependent and independent pathways. Furthermore, our recent clinical probe study has revealed a 70-fold increase in levels of urinary uroguanylin in patients with congestive heart failure. In conclusion, our studies support the concept that uroguanylin and guanylin are endogenous effector peptides involved in regulating body salt and water homeostasis.
Asunto(s)
Activadores de Enzimas/farmacología , Hormonas Gastrointestinales , Riñón/efectos de los fármacos , Péptidos/farmacología , Animales , Animales Recién Nacidos , Células Cultivadas , GMP Cíclico/metabolismo , Relación Dosis-Respuesta a Droga , Guanilato Ciclasa/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/efectos de los fármacos , Riñón/fisiología , Masculino , Ratones , Ratones Endogámicos ICR , Ratones Noqueados , Natriuresis/efectos de los fármacos , Péptidos Natriuréticos , Péptidos/fisiología , ARN Mensajero/metabolismo , Receptores de Enterotoxina , Receptores Acoplados a la Guanilato-Ciclasa , Receptores de Péptidos/metabolismo , OrinaRESUMEN
Uroguanylin and guanylin are newly discovered endogenous heat-stable peptides that bind to and activate a membrane bound guanylyl cyclase signaling receptor (termed guanylyl cyclase C; GC-C). These peptides are not only found in blood but are secreted into the lumen of the intestine and effect a net secretion of electrolytes (Na+, K+, Cl-, HCO3-) and fluid into the intestine via a cyclic guanosine-3',5'-monophosphate (cGMP) mechanism. GC-C is also the receptor for Escherichia coli heat-stable enterotoxin (STa) and activation by STa results in a diarrheal illness. Employing mouse renal in vivo models, we have demonstrated that uroguanylin, guanylin, and STa elicit natriuretic, kaliuretic, and diuretic effects. These biological responses are time- and dose-dependent. Maximum natriuretic and kaliuretic effects are observed within 30-40 min following infusion with pharmacological doses of the peptides in a sealed-urethra mouse model. Our mouse renal clearance model confirms these results and shows significant natriuresis following a constant infusion of uroguanylin for 30 min, while the glomerular filtration rate, plasma creatinine, urine osmolality, heart rate, and blood pressure remain constant. These data suggest the peptides act through tubular transport mechanisms. Consistent with a tubular mechanism, messenger RNA-differential display PCR of kidney RNA extracted from vehicle- and uroguanylin-treated mice show the message for the Na+/K+ ATPase g-subunit is down-regulated. Interestingly, GC-C knockout mice (Gucy2c -/-) also exhibit significant uroguanylin-induced natriuresis and kaliuresis in vivo, suggesting the presence of an alternate receptor signaling mechanism in the kidney. Thus, uroguanylin and guanylin seem to serve as intestinal and renal natriuretic peptide-hormones influencing salt and water transport in the kidney through GC-C dependent and independent pathways. Furthermore, our recent clinical probe study has revealed a 70-fold increase in levels of urinary uroguanylin in patients with congestive heart failure. In conclusion, our studies support the concept that uroguanylin and guanylin are endogenous effector peptides involved in regulating body salt and water homeostasis.
Asunto(s)
Animales , Masculino , Ratones , Activadores de Enzimas/farmacología , Riñón/efectos de los fármacos , Péptidos/farmacología , GMP Cíclico , Guanilato Ciclasa , Intestinos , Natriuresis/efectos de los fármacos , Péptidos/fisiología , ARN MensajeroRESUMEN
In much of the developing world, sharp curettage (SC) is the most commonly used technique for treating incomplete abortion. The procedure is usually performed in a hospital setting where physicians and operating theatres are available; it often involves light to heavy sedation for pain control and an overnight hospital stay for patient recuperation and monitoring. This study examined the hypothesis that use of manual vacuum aspiration (MVA)--a variation of vacuum aspiration (VA)--would be less costly than SC and thus be advantageous to healthcare systems with limited resources. The purpose of the study was to identify and, where possible, to explain the factors that contributed to cost differences between MVA and SC for treatment of incomplete abortion. To achieve this objective, researchers observed patient management and documented resource use at hospital sites in Kenya and Mexico. The results of the study support the researchers' hypothesis that, in most cases, treatment with MVA required a shorter patient stay and fewer hospital resources than SC, as the two techniques were practiced at the various study sites. The policy decision to adopt MVA, supported by procurement of instruments and incorporation of training in its use, is the basic prerequisite to achieving reduced levels of resource use. The study results also suggest that the full advantages of MVA can be realized only if it is introduced in conjunction with certain changes in patient management, such as offering outpatient treatment for incomplete abortion.