RESUMO
The purpose of this article is to report on the development and initial use of a pesticide knowledge test (PKT) specifically designed to evaluate agricultural workers' knowledge of the content mandated by the federal Worker Protection Standard (WPS). The PKT is a 20-item, true-false test, used in a sample of 414 adult and adolescent migrant farmworkers in Oregon. The overall mean score, i.e., number correct, was 15.67(78.4%), with both adults and adolescents demonstrating the most difficulty with questions related to the overall health effects of pesticides. The internal consistency was 0.73, when estimated using a method to correct for small sample sizes. Only six items had less than 70% correct answers. Content validity was achieved by basing the items directly on the Worker Protection Standard; face validity was obtained by having the final version of the test reviewed by a bilingual (English-Spanish) educator familiar with the requirements of the WPS. Overall, adult participants scored better than adolescents, and those with previous pesticide training scored better than those without. There were no differences in scores based on gender or whether the test was taken in English or Spanish; however, participants who spoke indigenous languages scored significantly lower than those who did not. These results indicate that the PKT is a valid, reliable measure of worker knowledge of the content of the WPS, although it does not measure the extent to which that knowledge is actually used in the work setting.
Assuntos
Doenças dos Trabalhadores Agrícolas/prevenção & controle , Exposição Ambiental/efeitos adversos , Conhecimentos, Atitudes e Prática em Saúde , Hispânico ou Latino/psicologia , Saúde Ocupacional , Praguicidas/efeitos adversos , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , México/etnologia , Oregon , Medição de Risco , Inquéritos e Questionários , Migrantes , Estados Unidos , United States Environmental Protection AgencyRESUMO
Several reports have demonstrated that radiofrequency catheter ablation provides effective control of a variety of supraventricular and ventricular tachycardias. This report details the results of radiofrequency catheter ablation in 1500 consecutive patients with a wide variety of supraventricular and ventricular tachycardias treated in the Instituto Nacional de Cardiología "Ignacio Chavez", between April 22, 1992 until December of 1999. Tachycardias were associated with the presence of an accessory pathway in 987 patients (65.8%). Dual accessory pathways were present in 24 patients giving a total of 1,012 accessory pathways. The mechanism of the arrhythmia was atrioventricular nodal reentrant tachycardia in 321 patients (21.4%). Ablation of the reentrant circuit of atrial flutter within the right atrium was attempted in 109 (7.2%) patients and a primary atrial tachycardia in 13 patients (0.8%). Atrioventricular node ablation and permanent pacemaker implantation were performed in 26 patients (1.7%). Finally we performed radiofrequency catheter ablation in 37 (2.4%) patients with ventricular tachycardia. Radiofrequency catheter ablation was successful in 908 of 1012 (89.7%) patients with accessory pathways with a complication rate of 10 (0.98%) and a recurrence rate of 92 (9%). AV nodal reentry was successfully abolished in 319 of 321 patients by selective ablation of the slow pathway in 297/321 (92.5%) patients and the fast pathway in 22/24 (92%) patients. The complication rate of this group was 8/321 (2.4%) with a recurrence rate of 34 patients (10.5%). The reentrant circuit of atrial flutter was ablated successfully in 86 of 109 (76.8%) patients with a recurrence flutter in 14 (12.8%) patients. Five of 13 (38.4%) cases of primary atrial tachycardia were successfully ablated. Complete AV block was achieved in 26 of 26 (100%) patients with atrial fibrillation or flutter treated by AV nodal ablation. The procedure was successful in 28 of 37 (75.6%) patients with fascicular ventricular tachycardia. The results of this series of patients demonstrates the safety and efficacy of radiofrequency ablation for the treatment of a wide variety of taquicardias with high rate of success 1375 of 1500 patients (91.6%), with 142 recurrences (9.4%), 15 complications (1%), and no mortality.
Assuntos
Ablação por Cateter/métodos , Taquicardia/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Flutter Atrial/cirurgia , Nó Atrioventricular/cirurgia , Criança , Pré-Escolar , Eletrocardiografia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Taquicardia/fisiopatologia , Taquicardia Supraventricular/cirurgia , Taquicardia Ventricular/cirurgiaRESUMO
To obtain information on the route(s) of ammonium assimilation in Streptomyces venezuelae, cell suspensions transferred to fresh medium lacking nitrogen were pulsed with [15N2]ammonium sulphate. Cells and extracellular fluids were examined by nuclear magnetic resonance and amino acid analysis to assess changes in amino acid pools and the disposition of [15N]ammonium. Following addition of [15N]ammonium, glutamate--glutamine pools of low cell density replacement cultures expanded rapidly and became progressively labelled with 15N, whereas the alanine pool size increased much more slowly and became labelled with 15N to a much lesser extent. These results are consistent with the assimilation of ammonium via glutamate dehydrogenase or glutamine synthetase--glutamate synthase rather than alanine dehydrogenase. Under anaerobic conditions, S. venezuelae assimilates ammonium into alanine rather than glutamate--glutamine. Alanine dehydrogenase may thus function as a vehicle to regenerate NAD+ to maintain substrate-level phosphorylation during periods of anaerobiosis.
Assuntos
Sulfato de Amônio/metabolismo , Streptomyces/metabolismo , Alanina/metabolismo , Anaerobiose , Glutamatos/metabolismo , Ácido Glutâmico , Glutamina/metabolismo , Ácidos Cetoglutáricos/metabolismo , Espectroscopia de Ressonância Magnética , Radioisótopos de Nitrogênio , Piruvatos/metabolismo , Ácido Pirúvico , Especificidade da Espécie , Streptomyces/crescimento & desenvolvimentoRESUMO
Cultures of Streptomyces venezuelae presented with a mixture of ammonium and an amino acid as nitrogen sources used both compounds together. Absence of ammonium repression of alternative nitrogen assimilation pathways was also observed when ammonium was added to cultures already growing on proline. The presence of ammonium in the medium ab initio depressed the yield of chloramphenicol. However, its addition to a culture growing on proline caused only a temporary inhibition of antibiotic synthesis, even when sufficient ammonium was added to create an excess. Continuous cultures supplied with ammonium as the growth-limiting nutrient showed no significant change in specific antibiotic production at different specific growth rates. The overall results indicate that in S. venezuelae neither nitrogen utilization pathways nor chloramphenicol biosynthesis is controlled by nitrogen repression.
Assuntos
Cloranfenicol/biossíntese , Compostos de Amônio Quaternário/metabolismo , Streptomyces/metabolismo , Técnicas Bacteriológicas , Meios de Cultura , Streptomyces/crescimento & desenvolvimentoRESUMO
Bilateral hearing loss occurred in 9.7% of infants who survived despite very low birth weight (less than or equal to 1500 gm), 16.7% of infants who survived neonatal seizures, and 28.6% of infants who survived both low birth weight and neonatal seizures. All neonates received treatment in a single neonatal intensive care unit between 1976 and 1980. Twenty-two of 36 hearing-impaired children were normal physically and mentally, with IQ scores of greater than or equal to 85. Significant neonatal predictors of hearing loss in high-risk premature infants (less than or equal to 36 weeks gestation), as determined by multivariable testing, were prolonged respirator care, high serum bilirubin concentration, and hyponatremia. Exchange transfusions were associated with a decreased risk of hearing loss.
Assuntos
Perda Auditiva Neurossensorial/etiologia , Recém-Nascido de Baixo Peso , Audiometria de Resposta Evocada , Peso ao Nascer , Desenvolvimento Infantil , Feminino , Seguimentos , Idade Gestacional , Perda Auditiva Neurossensorial/diagnóstico , Humanos , Lactente , Recém-Nascido , Doenças do Prematuro , Unidades de Terapia Intensiva Neonatal , Masculino , Estudos Prospectivos , Risco , Convulsões/complicações , Fatores Sexuais , Estatística como AssuntoRESUMO
Cultures of Streptomyces venezuelae released acidic metabolites during nitrogen-limited growth on glucose. The main products were pyruvic acid and alpha-ketoglutaric acid. Variation in the extent of acid production was observed; spores of the parental strain 13s gave approximately 10% of low-producing colonies when plated on acid-base indicator medium. Examination of one low producer, strain PC 51-5, showed that differences in acid production became apparent only in low-glucose media containing manganese. In both strains PC 51-5 and 13s, uptake of alpha-keto-[5-14C]glutaric acid occurred by diffusion and no marked differences in permeability to alpha-ketoglutarate were detected. However, differences were observed in the activity of alpha-ketoglutarate dehydrogenase. In cultures of strain PC 51-5, the specific activity of the enzyme increased throughout growth, whereas in the parental strain activity decreased and could not be detected in older mycelium. Loss of enzyme activity was accompanied by excretion of alpha-ketoglutaric acid and failure to assimilate the product after glucose exhaustion. The results suggest that accumulation of pyruvic and alpha-ketoglutaric acids in S. venezuelae cultures grown in glucose-containing media may be due to regulatory suppression of the dehydrogenases by this carbon source.
Assuntos
Ácidos Cetoglutáricos/biossíntese , Piruvatos/biossíntese , Streptomyces/metabolismo , Permeabilidade da Membrana Celular , Cloranfenicol/metabolismo , Meios de Cultura , Difusão , Glucose/farmacologia , Complexo Cetoglutarato Desidrogenase/metabolismo , Complexo Piruvato Desidrogenase/metabolismo , Ácido Pirúvico , Streptomyces/efeitos dos fármacos , Streptomyces/enzimologia , Streptomyces/genéticaRESUMO
Cultures of Streptomyces venezuelae grown in a medium containing glucose with mixtures of ammonium and nitrate as the nitrogen source produced chloramphenicol in a distinct idiophase that followed biomass accumulation. Analysis of fermentation broths showed that ammonium and nitrate were taken up consecutively by the organism. Measurements of nitrate reductase in the mycelium established that the enzyme was constitutive and that its specific activity did not increase during the period when ammonium was exhausted from the medium and nitrate was assimilated. The enzyme was neither repressed nor inhibited by ammonium. Production of chloramphenicol was also delayed until ammonium had been consumed and remained slow until subsequent depletion of nitrate. Arylamine synthetase, the initial enzyme in the pathway of antibiotic biosynthesis, showed no marked change in specific activity during utilization of the two nitrogen sources. The result suggests that the mechanism causing preferential utilization of ammonium does not simultaneously control the onset of chloramphenicol biosynthesis.