Objective.So far,it has not been established a satisfactory method for early diagnosis and studying on epidemiology for leprosy,we want to develop a molecular biological method for solving this point.Materials and methods.Based on the M.leprae gene coding groEL,65kD and 16S rRNA,three polymerase chain reactions were developed by using plikaytis',Woods' and Pattyn's procedures.It was optimized that the experimental parameters for each PCR,and a comparative study on practivity among three PCRs was also conducted for practical purpose.Results and conclusion.For detecting infection with M.leprae,all of PCRs established by us were highly sensitive and specific,but for practicl purpose,the woods'PCR optimized by us ought to be chosen firstly.

A sero-epidemiological survey on 1 833 healthy residents was carried out in 6 villages of a leprosy high-endemic area in Wenshan and Guangnan counties, Yunnan Province. The part of the residents with initially antibody-positive as well as the part of residents with initially antibody-negative have been followed up for 3 consecutive years by serology and clinical examination for studying kinetic changes of antibody to M.leprae and its relation with clinical disease. The results showed that the rates of subclinical infection of leprosy in a high-endemic area are different from village to village, and the risk of developing clinical disease does not associate with subclinical infection rate. It correlates with the number of cured accumulative leprosy cases and active cases within the village. The authors consider that in leprosy high-endemic villages, especially those cropped up new multi-bacillary leprosy cases frequently in recent years, it may be helpful to use serology to detect early leprosy cases.

OBJECTIVETo determine the prevalence, cause and distributions of blindness and poor vision in patients with leprosy.

METHODSAn epidemiological survey of blindness and poor vision among 1045 cases of leprosy was carried out in Taixing City of Jiangsu Province, China.

RESULTSThe prevalence of bilateral blindness was 7.67%, unilateral blindness 4.4%, bilateral poor vision of various degrees 9.28% and unilateral poor vision 5.84%. The prevalence of eye complications varied significantly among different groups of patients; females had a higher prevalence than males, multibacillary patients higher than paucibacillary patients, and in-patients higher than out-patients. Corneal disease was the most common cause of blindness in study groups, followed by iritic disease and cataract; while the main cause of poor vision was cataract, then corneal and iritic diseases. Treatable blindness accounted for 62.7% of the cases and treatable poor vision for 88.6% of the patients studied. 56.62% of cases with eye complications expressed their willingness to be treated.

CONCLUSIONSAlthough prevention and treatment of low vision and blindness in leprosy patients is very hard, it is necessary for doctors and medical workers to make clear of the factors to cause low vision and blindness, especially those in leprosy patients so that some measures for prevention and treatment of the disease could be taken accordingly.

Adult ; Aged ; Aged, 80 and over ; Blindness ; epidemiology ; etiology ; China ; epidemiology ; Female ; Humans ; Leprosy ; complications ; Male ; Middle Aged ; Prevalence ; Vision, Low ; epidemiology ; etiology

OBJECTIVETo observe the lung injury in rats induced by SiO₂ nanoparticles.

METHODSOne hundred and fifty SD rats were divided into five groups: the control group, the nanosized SiO₂ groups of 6.25, 12.5, 25 mg/ml, and the microsized SiO₂ group of 25 mg/ml, 30 rats each group. On the 7th, 15th, 30th, 60th and 90th day after exposure, six rats were sacrificed at each time point and the lung viscera coefficient, the pathological morphology and ultrastructure of lung were observed.

RESULTSAt each time point, the rat lung viscera coefficient of 25 mg/ml microsized SiO₂ and nanosized SiO₂ group were higher than the physiological saline group (P < 0.05), 25 mg/ml microsized SiO₂ group was higher than the same dose of nanosized SiO₂ group (P < 0.05); With longer duration of dye dust, lung viscera coefficient of 25 mg/ml microsized SiO₂ group and each dose of nanosized SiO₂ group were in time-effect relationship. Under light microscope we can see microsized SiO₂ group gradually formed cellularity nodules, and fused into fibrous nodules; At the early stage 25 mg/ml nanosized SiO₂ group occured focal alveolar macrophages and fibroblast proliferation and later fibrous connective tissue proliferated. Under TEM osmium lamellar corpuscle of type II alveolar epithelial cells were abnormal, and collagen and elastic fiber proliferated in mesenchyme of microsized and nanosized SiO₂ group.

CONCLUSIONNanosized SiO₂ particles after exposure can cause lung tissue injury in rat, and at the early stage it is showed inflammation, and later mainly characterized by pulmonary interstitial fibrosis differing from nodular lung fibrosis caused by microsized SiO₂, its ability to fibrosis is weaker compared with the same concentration of microsized SiO₂.

Animals ; Lung ; drug effects ; pathology ; ultrastructure ; Lung Injury ; chemically induced ; Male ; Nanoparticles ; toxicity ; Pulmonary Fibrosis ; chemically induced ; pathology ; Rats ; Rats, Sprague-Dawley ; Silicon Dioxide ; toxicity