维生素K3粉末降解动力学

在温度为50～90℃,相对湿度为50～93%范围内,维生素K₃的变色速率方程为—dR/dt=k_RR,降解速率方程为d(C_o—c)/dt=k_C(c_o—c)^1/2,光解速率方程为—dR/dt=k_P(R_o—R)^-1。k_R和_C与热力学温度T和相对湿度RH的关系通式为k=k′exp(—E_A/RT)exp(m′RH)。在实验温度和湿度范围内,变色和降解的表观活化能平均值分别为105.51和130.72 kJ/mol。     

指数程序升温药物稳定性试验

介绍了一种新的程序升温(指数程序升温)药物稳定性预测加速试验方法及计算方法。在这一新的程序升温方法中,温度每升高10℃,升温速率将增大2～4倍:dT/dt=a^(T-T₀)/10·(dT/dt)₀,使药物在高温和低温范围内的降解程度尽可能一致,提高了试验准确度。采用单因素优选法和数值积分法处理试验数据,避免了任何近似处理,使计算结果准确可靠。与线性升温、倒数升温和对数升温加速试验进行了对比,结果表明,指数程序升温法的准确性优于其它3种升温法。     

Cryptosporidium Spp., a frequent cause of diarrhea among children at the Korle-Bu Teaching Hospital, Accra, Ghana

This report presents the results of a study conducted at the Child Health Department, Korle-Bu Teaching Hospital, Accra, Ghana, between the months of October 2001 and June 2002. Stool samples from 227 children with diarrhea and 77 children without diarrhea, aged less than 5 years, were tested for Cryptosporidium spp. Prevalence rates were 27.8 and 15.6% in children with and without diarrhea, respectively. Cryptosporidium infection was found to be high in children between the ages of 6 and 24 months. Cryptosporidium spp. was more common in malnourished children, but was not isolated in children under 6 months of age who were exclusively breastfed. Neither the presence of domestic animals, abdominal pain, blood in stool, nausea, vomiting, nor the consumption of untreated water was associated with Cryptosporidium spp. infection. Shigella, Salmonella, and yeast-like organisms were the most frequently identified enteropathogenic bacteria. In summary, this study demonstrates the prevalence of Cryptosporidium spp. among Ghanaian children.     

Paradoxically elevated efavirenz concentrations in HIV/tuberculosis-coinfected patients with CYP2B6 516TT genotype on rifampin-containing antituberculous therapy

Some individuals have higher efavirenz plasma concentrations during rifampin-containing tuberculosis (TB) therapy, contrary to the expected induction effect of rifampin. Among HIV-infected patients without (n = 38) and with TB on rifampin-containing therapy (n = 18), we tested the hypothesis that drug-gene interaction may explain the highly variable drug interactions. Two-way analysis of variance revealed a significant interaction between CYP2B6 516G→T polymorphism and rifampin-containing therapy, suggesting that efavirenz dose adjustment may need to be individualized on the basis of the patient's genotype.     

Relationship of Psychosocial Risk Factors, Certain Personality Traits and Myocardial Infarction in Indians: A Case�Ccontrol Study

Objective:

To investigate the relationship of psychosocial factors (lack of social support, stress and subjective well-being) and personality traits with myocardial infarction (MI).

Materials and Methods:

A case–control study involving 100 cases and 100 matched controls was conducted in Lok Nayak Hospital, New Delhi.

Results:

Stress over 1 year was significantly higher in cases (P < 0.001). However, difference was not significant when scores of social support (P = 0.2), Presumptive Stressful Life Event (PSLE) over lifetime (P = 0.058) and subjective well-being (P = 0.987) were compared. MI was significantly associated with hyperactive (P < 0.001), dominant (P = 0.03), egoistic (P < 0.001) and introvert (P < 0.001) personalities.

Conclusion:

Certain personality traits and recent stress may be important risk factors of MI, especially in Indians. The finding may have implications on the preventive strategies planned for MI patients.