胶束电动毛细管色谱法分离和测定几种大黄含量

建立了胶束电动毛细管色谱法分离和测定几种大黄中大黄素、芦荟大黄素、大黄酸含量的测定方法。缓冲液为含0.025mol·L^-1十二烷基磺酸钠(简称SDS)的0.025mol,L-13-环己氨基-1-丙烷磺酸(简称CAPS)-乙腈(100:10),pH0.96。线性范围:芦荟大黄素为0.0025～0.0175mg·ml^-1(r=0.9999),大黄素为0.005～0.05mg·ml^-1(r=0.9999),大黄酸为0.005～0.035mg·ml^-1(r=0.9996)。回收率:芦荟大黄素为98.2%～101.8%,大黄素99.9%～101.9%,大黄酸99.2/～101.2%。此法简便、快速、重现性好。     

Prevalence of work-related respiratory symptoms in Iranian farmers

BACKGROUND:

Animal exposure may be an important trigger for work-related symptoms among farmers.

OBJECTIVE:

To estimate the prevalence of work-related respiratory symptoms (WRS) in sheep breeders and agricultural farmers and to determine work-related risk factors.

METHODS:

A family doctor used a questionnaire to interview a cohort of 173 farmers comprised of 127 sheep breeders and 46 agricultural farmers in the rural area of Rokh (northeast Iran). The questionnaire pertained to recurrent wheezing, cough, breathlessness or chronic phlegm while at work (these symptoms define WRS), flu-like illness and physician-diagnosed asthma.

RESULTS:

There were 71 subjects (41%) with WRS: 10 of 46 agricultural farmers (21.7%) and 61 of 127 sheep breeders (48.0%). The proportions of sheep breeders with wheezing (16.5%), asthma (14%), cough (29%), breathlessness (31.5%) and flu-like illness (38%) were higher than in agricultural farmers. A significant dose-response relationship among the daily hours worked with animals, the number of animals and the prevalence of symptoms was established for sheep farmers. Sheep shearing and the use of pesticide were associated with an increased risk of wheezing and phlegm.

CONCLUSIONS:

The results suggest that sheep farmers in general have higher rates of work-related symptoms than agricultural farmers. The severity of work-related symptoms will increase with an increase in frequency of animal contact; therefore, these results may underestimate the impact of this exposure.     

Generation of CFU-C/suppressor T cells in vitro: an experimental model for immune-mediated marrow failure

T cells were derived from the bone marrow of 8 healthy donors and fractionated, according to their receptors for the Fc fragment of IgG, into TG+ and TG- lymphocytes. These were then cocultured with autologous or allogeneic bone marrow cells in agar in the CFU-C assay. No significant suppresion of colony formation could be detected. Total T, TG+, and TG- cells were then incubated for 18 hr with PWM, washed, and cocultured with bone marrow cells. PWM-treated TG- cells showed no significant CFU-C suppressor activity, whereas PWM-treated total T and TG+ cells inhibited colony formation of both autologous and allogeneic marrow cells. The supernatant of PWM-treated total T and TG+ cells also inhibited colony formation. PWM alone enhanced colony formation. The results of this study indicate that normal T cells can be activated in vitro to become CFU-C/suppressor cells after PWM stimulation, and that this effect is mediated by T cells with the Fc receptor for IgG.