RESUMO
To assess the drug-behavior interaction effects with an 8-year-old boy wih attention deficit hyperactivity disorder, common classroom antecedent (e.g., seating arrangement) and consequent (e.g., peer prompts) stimuli were alternated within a school day while drug conditions (methylphenidate vs. placebo) were alternated across days. The results suggested that peer attention maintained disruptive behavior when methylphenidate was absent but not when it was present.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/terapia , Terapia Comportamental/métodos , Estimulantes do Sistema Nervoso Central/administração & dosagem , Metilfenidato/administração & dosagem , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Estimulantes do Sistema Nervoso Central/efeitos adversos , Criança , Terapia Combinada , Humanos , Masculino , Metilfenidato/efeitos adversos , Grupo Associado , Reforço Social , Meio SocialRESUMO
This study evaluated the potential for gene transfer of a large catabolic plasmid from an introduced organism to indigenous soil recipients. The donor organism Alcaligenes eutrophus JMP134 contained the 80-kb plasmid pJP4, which contains genes that code for mercury resistance. Genes on this plasmid plus chromosomal genes also allow degradation of 2,4-dichloruphenoxyacetic acid (2,4-D). When JMP134 was inoculated into a nonsterile soil microcosm amended with 1,000 micrograms of 2,4-D g-1, significant (10(6) g of soil-1) populations of indigenous recipients or transconjugants arose. These transconjugants all contained an 80-kb plasmid similar in size to pJP4, and all degraded 2,4-D. In addition, all transconjugants were resistant to mercury and contained the tfdB gene of pJP4 as detected by PCR. No mercury-resistant, 2,4-D-degrading organisms with large plasmids or the tfdB gene were found in the 2,4-D-amended but uninoculated control microcosm. These data clearly show that the plasmid pJP4 was transferred to indigenous soil recipients. Even more striking is the fact that not only did the indigenous transconjugant population survive and proliferate but also enhanced rates of 2,4-D degradation occurred relative to microcosms in which no such gene transfer occurred. Overall, these data indicate that gene transfer from introduced organisms is an effective means of bioaugmentation and that survival of the introduced organism is not a prerequisite for biodegradation that utilizes introduced biodegradative genes.
Assuntos
Alcaligenes/genética , Técnicas de Transferência de Genes , Plasmídeos/genética , Microbiologia do Solo , Ácido 2,4-Diclorofenoxiacético/metabolismo , Alcaligenes/efeitos dos fármacos , Alcaligenes/metabolismo , Biodegradação Ambiental , Conjugação Genética , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Concentração de Íons de Hidrogênio , Mercúrio/farmacologiaRESUMO
Using radioimmunoassay methods, the blood of patients with pancreatic tumors was screened for circulating polypeptide hormones. This screening discovered pancreatic polypeptide in abnormally high concentration in the serum of six of seven patients with adenocarcinomas of the bile duct. The assay appears to be very sensitive finding excessive residual pancreatic polypeptide production after palliative resections. Serum pancreatic polypeptide assays warrant evaluation as an aid in the diagnosis and management of patients with bile duct tumors.