RESUMEN
As a novel antibiotic resistance determinant, investigation of the occurrence and characteristics of class 1 integron was performed on nosocomial methicillin-resistant Staphylococcus aureus (MRSA) strains sampled during 2001-2006. Seventy-six out of 179 (42.5%) of the tested strains were found to carry class 1 integrons, with four unique arrays of gene cassettes detected. This is the first report of the comprehensive identification and typing of class 1 integrons in clinical MRSA isolates over a 6-year period, representing the first evidence for class 1 integrons as possible antibiotic resistance determinants in clinical MRSA strains.
Asunto(s)
Integrones , Staphylococcus aureus Resistente a Meticilina/genética , Infecciones Estafilocócicas/microbiología , Técnicas de Tipificación Bacteriana , China , Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana , Humanos , Resistencia a la Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Infecciones Estafilocócicas/epidemiologíaRESUMEN
A morphologically distinct Fijian sponge, Plakortis sp., has yielded two new peroxides, plakortolide E [5] and plakoric acid [12]. After standing for approximately one year, plakortolide E rearranged to plakortolide ether [10]. The structures of plakortolide E [5] and plakortolide ether [10] were established from 2D nmr data and by analogy to a known compound, plakortolide [3]. The stereochemistry of the bicyclic ring substituents of 5 was established using nOe and NOESY nmr data along with comparisons to 3. The absolute stereochemistry at the three chiral sites of 5 was assigned by preparing acyclic compounds 6-9, and both 8 and 9 were investigated using the modified Mosher's method. This represents the first absolute stereochemistry determination for a sponge-derived polyketide peroxide. The characterization of plakoric acid [12] was based on spectral analogies to known polyketides such as plakortin. Plakortolide E [5] exhibited selective potency against the melanoma and breast tumor cell lines in the in vitro 60-cell line panel of the National Cancer Institute.
Asunto(s)
4-Butirolactona/análogos & derivados , Antineoplásicos/química , Dioxanos/química , Poríferos/química , Propionatos/química , 4-Butirolactona/química , 4-Butirolactona/aislamiento & purificación , 4-Butirolactona/farmacología , Animales , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Dioxanos/aislamiento & purificación , Dioxanos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Espectroscopía de Resonancia Magnética , Estructura Molecular , Propionatos/aislamiento & purificación , Propionatos/farmacología , Estereoisomerismo , Células Tumorales CultivadasRESUMEN
In today's increasingly competitive medical practice environment, legal challenges to credentialing decisions abound. To minimize the risk of liability, hospitals and their medical staffs must be especially careful when adopting and applying the criteria for medical staff membership.
Asunto(s)
Competencia Clínica/legislación & jurisprudencia , Habilitación Profesional/legislación & jurisprudencia , Responsabilidad Legal , Privilegios del Cuerpo Médico/legislación & jurisprudencia , Relaciones Interpersonales , Estados UnidosRESUMEN
Glucans, called elicitors, isolated from cell walls of Phytophthora infestans, caused rapid agglutination and death of protoplasts isolated from potato leaf tissue. Cells incubated with high concentrations of elicitor were rapidly killed, but did not agglutinate. Agglutination and cell death did not occur with any of several commercial polysaccharides including laminarin, but laminarin did inhibit elicitor-mediated agglutination. The results are consistent with the existence of specific elicitor receptor sites on the outer surface of potato leaf plasma membranes.
