RESUMEN
Secreted proteins are transported along intracellular route from the endoplasmic reticulum through the Golgi before reaching the plasma membrane. Small GTPase Rab and their effectors play a key role in membrane trafficking. Using confocal microscopy, we showed that MICAL-L1 was associated with tubulo-vesicular structures and exhibited a significant colocalization with markers of the Golgi apparatus and recycling endosomes. Super resolution STORM microscopy suggested at the molecular level, a very close association of MICAL-L1 and microdomains in the Golgi cisternae. Using a synchronized secretion assay, we report that the shRNA-mediated depletion of MICAL-L1 impaired the delivery of a subset of cargo proteins to the cell surface. The process of membrane tubulation was monitored in vitro, and we observe that recombinant MICAL-L1-RBD domain may contribute to promote PACSINs-mediated membrane tubulation. Interestingly, two hydrophobic residues at the C-terminus of MICAL-L1 appeared to be important for phosphatidic acid binding, and for association with membrane tubules. Our results reveal a new role for MICAL-L1 in cargo delivery to the plasma membrane.
Asunto(s)
Membrana Celular/metabolismo , Proteínas de Microfilamentos/metabolismo , Oxigenasas de Función Mixta/metabolismo , Aminoácidos , Sitios de Unión , Línea Celular , Técnica del Anticuerpo Fluorescente , Células HeLa , Humanos , Inmunohistoquímica , Proteínas de Microfilamentos/química , Proteínas de Microfilamentos/genética , Oxigenasas de Función Mixta/química , Oxigenasas de Función Mixta/genética , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Transporte de ProteínasRESUMEN
This paper describes an imaging microscopic technique based on heterodyne digital holography where subwavelength-sized gold colloids can be imaged in cell environments. Surface cellular receptors of 3T3 mouse fibroblasts are labeled with 40 nm gold nanoparticles, and the biological specimen is imaged in a total internal reflection configuration with holographic microscopy. Due to a higher scattering efficiency of the gold nanoparticles versus that of cellular structures, accurate localization of a gold marker is obtained within a 3D mapping of the entire sample's scattered field, with a lateral precision of 5 nm and 100 nm in the x,y and in the z directions respectively, demonstrating the ability of holographic microscopy to locate nanoparticles in living cell environments.
Asunto(s)
Oro/análisis , Holografía/métodos , Microscopía/métodos , Nanopartículas/ultraestructura , Procesamiento de Señales Asistido por Computador , Animales , Ratones , Células 3T3 NIHRESUMEN
INTRODUCTION: Childhood injuries are the leading cause of death for children between 5 to 14 years of age in Singapore. However, there is no information or data on childhood injuries in the community in Singapore. There was a need to conduct a nationwide study on childhood injuries in Singapore in order to estimate the prevalence rate, types of injuries, and to identify the hazards in the homes of the children. METHODS: A cross-sectional nationwide study with a two-stage stratified random sampling was conducted to obtain a representative sample of the Singapore population. Families that had children younger than 15 years of age were selected for the study. Parents and caregivers were interviewed at their homes. RESULTS: There were 2322 children in the study, of which 452 had one or more injuries in the past one year, giving an overall prevalence rate of 19.5 percent. Of the children who had injuries, the home was the commonest place where injuries occurred (45 percent) and falls were the leading cause of injuries (77 percent). There were many hazards identified in the homes studied and it was found that the more hazards present in the homes, the more likely it is for the child to get injuries. CONCLUSION: There is a need for educational and interventional programmes to help Singaporeans understand the need to make the home environment safe for children and to prevent home injuries.
Asunto(s)
Accidentes/estadística & datos numéricos , Heridas y Lesiones/epidemiología , Accidentes Domésticos/estadística & datos numéricos , Adolescente , Niño , Preescolar , Estudios Transversales , Seguridad de Equipos , Composición Familiar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Intoxicación/epidemiología , Prevalencia , Modelos de Riesgos Proporcionales , Singapur/epidemiologíaRESUMEN
INTRODUCTION: Childhood injuries are the leading cause of death for children between 5 to 14 years of age in Singapore. There have been no studies done on primary caregivers' knowledge, attitude and practices on childhood injuries and its prevention in Singapore. Thus there is a need to conduct this type of study in order to develop appropriate educational programmes. METHODS: A cross-sectional nationwide study with a two-stage stratified random sampling was conducted to obtain a representative sample of the Singapore population. Families that had children younger than 15 years of age were selected for the study. Parents and caregivers were interviewed at their homes. RESULTS: The primary caregivers had good knowledge of road safety but poor knowledge on home safety and first aid. The higher the education of the mother, the more likely it is that she would possess the correct knowledge and practice on childhood injuries and its prevention. The media plays an important role on information on child safety of the caregivers. Only 38 percent said they obtained information from doctors and other health personnel. CONCLUSION: There is a need to educate parents and caregivers on home safety and first aid. Doctors and nurses should take a more active role in giving advice on child safety.
Asunto(s)
Prevención de Accidentes/estadística & datos numéricos , Accidentes/estadística & datos numéricos , Cuidadores/educación , Conocimientos, Actitudes y Práctica en Salud , Heridas y Lesiones/prevención & control , Accidentes/mortalidad , Accidentes Domésticos/mortalidad , Accidentes Domésticos/estadística & datos numéricos , Adolescente , Adulto , Anciano , Cuidadores/clasificación , Cuidadores/psicología , Niño , Preescolar , Estudios Transversales , Femenino , Vivienda , Humanos , Lactante , Masculino , Persona de Mediana Edad , Singapur/epidemiología , Encuestas y Cuestionarios , Heridas y Lesiones/epidemiología , Heridas y Lesiones/mortalidadRESUMEN
A 66-year-old man with chronic idiopathic intestinal pseudoobstruction was admitted for pneumatosis cystoides intestinalis, complicated by pneumoperitoneum. The latter conditions resolved after treatment with metronidazole. There was no favorable effect of the prokinetic agents cisapride and erythromycin. To the authors' knowledge, this is the first reported case of successful treatment of pneumatosis cystoides intestinalis with metronidazole in primary chronic intestinal pseudoobstruction.