A Lactobacillus rhamnosus strain induces protection in different sites after Salmonella enterica subsp. enterica serovar Typhimurium challenge in gnotobiotic and conventional mice / Uma cepa de Lactobacillus rhamnosus induz proteção em diferentes sítios em camundongos gnotobióticos e convencionais após desafio com Salmonella enterica subsp. enterica sorovar Typhimurium

The ability of a Lactobacillus rhamnosus strain isolated from a healthy breast-fed human newborn to reduce the pathological consequences for the host due to an experimental oral infection with Salmonella enterica subsp. enterica serov. Typhimurium in vivo was determined using gnotobiotic and conventional mice. Conventional mice received 0.1mL probiotic milk (8.0 log colony-forming unit) daily for 10 days before the oral pathogenic challenge (5.0 log colony-forming unit). Then probiotic treatment was continued until the end of the experiment. Probiotic treatment in germ-free mice consisted of a single dose of the probiotic milk at the beginning of the experiment and a challenge with S. Typhimurium 10 days later (3.0 log colony-forming unit). A protective effect was observed in both gnotobiotic and conventional animals in terms of histopathologic and morphometric data, but in different anatomical sites. This protection was observed in liver and intestines, respectively, for gnotobiotic and conventional mice. However, S. Typhimurium populations were similar in the feces of both treated and control gnotobiotic mice. We conclude that a protective effect of L. rhamnosus against experimental S. Typhimurium was observed. This protection was not due to the reduction of the population of pathogenic bacteria in the intestine...

A habilidade de uma cepa de Lactobacillus rhamnosus isolada de um recém-nascido saudável de reduzir as consequências patológicas para o hospedeiro após infecção experimental por Salmonella enterica subsp. enterica sorov. Typhimurium foi avaliada em camundongos gnotobióticos e convencionais. Os camundongos convencionais receberam 0,1mL de leite probiótico por dia (0,8 log unidade formadora de colônia), 10 dias antes do desafio oral com S. Typhimurium (5,0 log unidade formadora de colônia), e continuaram recebendo probiótico até o término do experimento. O tratamento com probiótico nos camundongos gnotobióticos consistiu em uma única dose de leite probiótico no início do experimento e desafio oral após 10 dias (3,0 log unidade formadora de colônia). Em termos histopatológicos e morfométricos, a proteção foi observada no fígado e nos intestinos nos animais gnotobióticos e convencionais, respectivamente. No entanto, a população de S. Typhimurium foi similar em ambos os grupos tratado e controle de animais gnotobióticos. Desta forma, conclui-se que a proteção conferida pela cepa de L. rhamnosus contra o desafio experimental S. Typhimurium foi observada em diferentes sítios anatômicos nos animais convencionais e gnotobióticos e que essa proteção não foi devido à redução da população de S. Typhimurium nos intestinos...

The radiological accident in Goiânia: the initial remedial actions.

The removal of a 50.9-TBq 137Cs source from a radiation therapy facility in Goiânia gave rise to a radiological accident in September 1987 whose proportions were aggravated by the 16-d interval from the beginning of a series of acts that resulted in the contamination of people and areas, to the moment of identification and seeking of aid. Data gathered from the declarations of persons involved in the accident, matched with the medical assessment and radiation monitoring of areas affected, made it possible to determine procedures for care of victims and for decontaminating operations of these areas. The priorities of these procedures were to provide care to victims and eliminate critical paths by which other persons might be affected by exposure to radiation or contamination. This paper presents (1) remedial actions taken during the first weeks, (2) management problems associated with the accident, and (3) lessons learned from this episode that are of benefit to us and, hopefully, to others.

Pre-operational environmental survey at the uranium mine and mill site, Poços de Caldas, Minas Gerais, Brazil.

The first Brazilian uranium mine and mill are located on the Pocos de Caldas plateau, in the Central State of Minas Gerais. The pre-operational environmental survey was carried out over a period of two years by the Brazilian Nuclear Energy Commission (CNEN), through the Instituto de Radioprotecão e Dosimetria (IRD). The selection of the materials to be monitored, the sampling points and the radionuclides to be analysed were based on critical parameters taking into account the meteorological and hydrological characteristics of the site as well as land use. The results obtained are sufficient to characterize the environmental background of the area, and will allow an assessment of the environmental impact due to the operation of the facility and an evaluation of the adequacy of the effluent emission control measures. In relation to their contribution to the population dose, the results indicated that 226Ra and 210Pb will be the important radionuclides.