Reduction in the formation of carcinogen-induced transformed foci by pencillin G sodium in the C3H/10T1/2 CL8 cell lines.

The C3H/10T1/2 CL8 cell line is being widely used to study mechanisms of malignant transformation in vitro. As currently employed, the standard assay system uses a combination of penicillin (100 I.U./ml) and streptomycin (50 micrograms/ml) to reduce the occurrence of bacterial contamination. The penicillin component of this mixture has been discovered to cause a reduction in the number of transformed foci which develop after exposure of cells to MCA, DMBA and X-rays. This reduction is dose dependent; 500 I.U./ml virtually eliminates transformation, while 100 I.U./ml causes an approximate 50% decrease in the number of foci. This effect does not appear to be due to overt toxicity and is largely reversible on removal of the antibiotic. Gentamicin (25 micrograms/ml) causes no reduction in the formation of transformed foci when compared to cultures maintained in antibiotic-free medium and offers the advantages of chemical stability, a wider spectrum of antibacterial activity in comparison with penicillin/streptomycin and, in addition, is active against many mycoplasma. It is suggested that future studies with this cell line should ideally be performed without antibiotics or should employ Gentamicin for antibacterial protection.     

Obstetrical care in future pregnancies after fetal loss in group B streptococcal septicemia. A prevention program based on bacteriological and immunological follow-up

Among 22 mothers of infants infected with group B streptococci (GBS), 19 showed markedly low levels of antibodies against the infecting type. Three of the patients with low antibody levels went through a new pregnancy within 1 yr after they had lost an infant (2 patients) or experienced fetal death due to GBS (1 patient). They were still urogenital carriers of the type of GBS causing the previous infection, and their serum levels of type-specific antibodies remained low. All three went through a successful pregnancy following a prevention program comprising antibiotic treatment from the 28th wk of pregnancy.     

平喘冲剂治疗小儿哮喘临床观察

为观察平喘冲剂治疗小儿哮喘的临床疗效,将196例患儿随机分为治疗组100例口服中药平喘冲剂,对照组96例静脉滴注青霉素、氨茶碱,疗程1周,观察治疗前后喘憋、咳嗽、紫绀、哮鸣音、肺功能、肺阻抗血流的变化。结果：治疗组总有效率为98．00％,对照组总有效率为93．75％,各项检测指标治疗组均优于对照组。提示平喘冲剂具有平喘止咳、化痰通瘀的作用。     

Bacterial resistance to penicillin G by decreased affinity of penicillin-binding proteins: a mathematical model

Streptococcus pneumoniae and Neisseria meningitidis have very similar mechanisms of resistance to penicillin G. Although penicillin resistance is now common in S. pneumoniae, it is still rare in N. meningitidis. Using a mathematical model, we studied determinants of this difference and attempted to anticipate trends in meningococcal resistance to penicillin G. The model predicted that pneumococcal resistance in a population similar to that of France might emerge after 20 years of widespread use of beta-lactam antibiotics; this period may vary from 10 to 30 years. The distribution of resistance levels became bimodal with time, a pattern that has been observed worldwide. The model suggests that simple differences in the natural history of colonization, interhuman contact, and exposure to beta-lactam antibiotics explain major differences in the epidemiology of resistance of S. pneumoniae and N. meningitidis.     

Using hospital antibiogram data to assess regional pneumococcal resistance to antibiotics

Antimicrobial resistance to penicillin and macrolides in Streptococcus pneumoniae has increased in the United States over the past decade. Considerable geographic variation in susceptibility necessitates regional resistance tracking. Traditional active surveillance is labor intensive and costly. We collected antibiogram reports from North Carolina hospitals and assessed pneumococcal susceptibility to multiple agents from 1996 through 2000. Susceptibility in North Carolina was consistently lower than the national average. Aggregating antibiogram data is a feasible and timely method of monitoring regional susceptibility patterns and may also prove beneficial in measuring the effects of interventions to decrease antimicrobial resistance.     

The Development of β-Lactam Antibiotics in Response to the Evolution of β-Lactamases

beta-Lactam antibiotics, viz., penicillin, penicillin derivatives, cephalosporins, cephamycins, carbapenems, monobactams. and monocarbams, are the most widely used of all antimicrobial classes by virtue of their high efficacy and specificity and the availability of several derivatives. The expression of one or several beta-lactamases (beta-lactam antibiotic-inactivating enzymes) represents the most widespread and the most clinically relevant resistance mechanism to these antibiotics. The development of beta-lactam antibiotics has thus been a continuous battle of the design of new compounds to withstand inactivation by the ever-increasing diversity of beta-lactamases. This article traces antibiotic development in response to the evolution of beta-lactamases.     

Do post-splenectomy patients take prophylactic penicillin?

Splenectomized patients are at risk of overwhelming infection and are advised to take life-long prophylactic oral penicillin. Compliance studies have not been published for adults in this situation. We used a standard biological assay to detect penicillin in the urine of 58 splenectomized patients. 24 (42%) patients had evidence of penicillin in their urine. Patients' sex, age, years from splenectomy and underlying diagnosis were not important factors in identifying good or poor compliance. Since 58% of patients did not take their penicillin on the day studied, we need to consider alternative strategies of antibiotic use and patient education.     

淋球菌引起新生儿结膜炎的临床分析

本文对我院1994－1998年收治的20例新生儿淋菌性结膜炎的发病情况进行了分析,结果表明：新生儿淋菌性结膜炎发病多由患有淋菌性阴道炎的母亲分娩时感染所至。本病的确诊是将结膜囊分泌物采用PCR方法检出淋球菌,应用青霉素作为本病的首选药物进行治疗,可使本病得以治愈。     

利用无机载体固定化青霉素酰化酶的研究

以无机材料６２０１型担体作载体,进行青霉素酰化酶固定化的研究。考察了ＡＰＴＳ和戊二醛浓度、给酶量以ｐＨ等因素对固定化酶酶活的影响。结果表明,以６２０１型担体为载体制备得到的固定化酶具有较高的酶活回收,达４２．８％;操作稳定性良好;用其连续水解３０批青霉素Ｇ的钾盐溶液,酶活未见明显下降;该固定化酶与游离酶相比,可在较宽的ｐＨ范围保持高酶活。     

THE GASTROINTESTINAL ABSORPTION OF PENICILLIN V IN CHILDREN WITH SUSPECTED COELIAC DISEASE

Abstract. The gastrointestinal absorption of penicillin V (pc-V) was investigated in 6 children, 6–12 months old, with suspected coeliac disease. The diagnosis was set after small bowel biopsy and absorption tests of vitamin A and d -xylose. As control groups served 7 children with diarrhoea but with normal small bowel biopsy and/or absorption tests and a group of 9 children with upper respiratory tract infection of the same ages as the children in the test group. The absorption of calcium pc-V in oil suspension (Penicals®) was impaired in the patients with suspected coeliac disease compared to that of the control groups. There was no significantly different absorption of pc-V between the control children with diarrhoea and those with upper respiratory tract infection. After 6–8 months of gluten free diet in the children with suspected coeliac disease their absorptive ability of oral calcium pc-V in suspension form was equal with that of a control group.