Experimental model of smoking and simulation of reflux with acid and pepsin in rats / Modelo experimental de tabagismo e simulação de refluxo com ácido e pepsina em ratos

PURPOSE: To develop experimental models to evaluate the effects of hydrochloric acid associated with the pepsin instilled in the mucosa of the upper esophagus and the esophagogastric junction of young male rats Wistar, simulating injury caused by gastroesophageal reflux on the mucosa of aero-digestive tract in humans as well as the action of the risk exposure of mucosa to cigarette smoke. METHODS: Fifty young male Wistar rats divided in 5 groups with 10 animals each one, respectively simulating pharyngo-laryngeal reflux and gastroesophageal reflux, pharyngo-laryngeal reflux and smoking, smoking only, gastroesophageal reflux and control group. RESULTS: The histopathologic studies no recorded neoplasias, only mild changes and no significant alterations. The hemo-oximetry (carboxyhemoglobin and methemoglobim) and CO2 concentration confirm that the animals were submitted to high intensity of exposure to carcinogens in tobacco and its derivatives. CONCLUSION: The experimental models were highly efficient, practical, easy to use and economical and can be employed in other similar studies to determine the harmful effects by smoking and reflux.

OBJETIVO: Desenvolver modelos experimentais para avaliar os efeitos do ácido clorídrico associado a pepsina, instilados na mucosa da parte superior do esôfago e da junção esofagogástrica de jovens ratos Wistar, simulando lesão causada por refluxo gastroesofágico na mucosa do trato aero-digestivo em humanos, bem como a ação da exposição ao risco de mucosa, como a fumaça de cigarro. MÉTODOS: Cinqüenta jovens ratos Wistar divididos em cinco grupos com 10 animais cada um, respectivamente, simulando o refluxo faringo-laríngeo e refluxo gastroesofágico, refluxo faringo-laríngeo e tabagismo, tabagismo só, refluxo gastroesofágico e grupo controle. RESULTADOS: os estudos histopatológicos não registraram neoplasias, apenas leves alterações e não significativas. O hemo-oximetria (carboxiemoglobina e metemoglobina) e concentração de CO2 corroboram que os animais foram submetidos a alta intensidade de exposição a substâncias cancerígenas do tabaco e seus derivados. CONCLUSÃO: os modelos experimentais desenvolvidos foram altamente eficientes, práticos, fáceis de usar e econômicos podendo ser empregados em outros estudos semelhantes para determinar os efeitos prejudiciais causados pelo tabagismo e refluxo.

Introduction of routine zinc therapy for children with diarrhoea: evaluation of safety.

On 8 May 2004, the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) recommended routine administration of zinc in the management of children, aged less than five years, with acute diarrhoea. In making the recommendation, WHO and UNICEF also suggested careful monitoring for adverse events associated with routine administration of zinc, particularly unusual or excess vomiting. The study assessed, in a phase IV trial, i.e. post-marketing surveillance of zinc, the occurrence of adverse events during the first hour after the administration of the first dose of zinc in children with acute or persistent diarrhoea. The study was conducted at the Dhaka Hospital of ICDDR,B and at an outpatient clinic operated by a local health NGO-Progoti Samaj Kallyan Protisthan (PSKP), Dhaka, Bangladesh. Eligible children, aged 3-59 months, were treated with 20 mg of zinc sulphate provided in a dispersible tablet formulation. The children were observed for 60 minutes following the initial treatment with zinc for adverse events, with particular attention given to vomiting or regurgitation. During the one-year observation period, 42,440 children (male 57% and female 43%) received zinc, and 20,246 (47.8%) of them were observed. Regurgitation and/or vomiting occurred in 4,392 (21.8%) of the children; 90.8% of these children had vomiting only once, 8.7% twice, and 0.5% more than twice. No children revisited the hospital for recurrent vomiting following their discharge. A significant proportion of infants and children may experience vomiting or regurgitation, usually once, following the administration of the first dose of zinc. This is a transient phenomenon that did not impact on continuation of treatment with zinc.