用微机对青霉素皮试作辅助判断的临床应用的探讨

目的探讨微机对青霉素皮试结果作辅助判断的准确性。方法我们根据青霉素皮试常规观察指标设计了青霉素皮试观察记录单,分三个时段观察青霉素皮试的结果。计算机程序判断青霉素皮试的结果是对观察记录经过综合分析得出的。结果应用计算机对376例青霉素皮试的结果进行辅助判定,其结果表明计算机程序对青霉素皮试结果的判断正确性不低于人工判定,经χ2检验P>0.05,说明两者判断结果无显著性。     

Reduced susceptibility to penicillin of viridans group streptococci in the oral cavity of patients with haematological disease

The occurrence of oral penicillin-resistant viridans group streptococci (VGS) was studied in 50 patients with either newly diagnosed acute leukaemia or autologous peripheral stem cell transplants. One patient was excluded because of Staphylococcus aureus growth in the stem cell harvest. VGS were isolated from the oral cavity of 48 of the remaining 49 patients. Of these 48 patients, 12 (25%) yielded VGS resistant (MIC > 2 mg/L) to penicillin. These 12 patients had a higher frequency of septicaemia (p 0.04) and more days of treatment with trimethoprim-sulphamethoxazole (p 0.04) than patients who harboured susceptible or intermediately resistant VGS (MIC 2 mg/L). There were no other statistically significant differences between the two groups. It is important to be aware of the high level of penicillin resistance in oral VGS in patients with haematological disease, and this parameter should be considered when selecting antibiotic therapy for cases of septicaemia caused by VGS in immunocompromised patients.     

Antimicrobial susceptibility profile of Neisseria gonorrhoeae at STI clinic

A total of 100 consecutive patients who attended a sexually transmitted infections clinic were studied. Thirteen had gonococcal urethritis, of which 10 showed growth of Neisseria gonorrhoeae on culture. All the isolates were tested for antimicrobial susceptibility by Australian Gonococcal Surveillance Programme (AGSP) method and beta lactamase production by chromogenic cephalosporin test. Four patients were co-infected with each of the following: HIV, HBV and Chlamydia trachomatis . Gonococcal urethritis (13%) was found more in male patients. Ten percent gonococcal isolates were penicillinase-producing N. gonorrhoeae , and another 10% were tetracycline-resistant N. gonorrhoeae .     

叶酸偶联的青霉素G酰化酶对叶酸受体阳性肿瘤细胞的靶向作用

目的 研究叶酸偶联的青霉素G酰化酶(F-PGA)对叶酸受体阳性肿瘤细胞的靶向作用.方法 用激光共聚焦显微镜观察宫颈癌HeLa、卵巢癌SKOV3和肺癌A549细胞对F-PGA以及游离叶酸(F-A)的摄取,并进一步用同位素示踪法加以验证和定量检测.结果 F-PGA与F-A相似,均能被叶酸受体阳性的HeLa和SKOV3肿瘤细胞选择性摄取,且有饱和性、可逆性、温度依赖性和高亲和性的特点,但不能被叶酸受体阴性的A549细胞摄取.结论 F-PGA与F-A都是通过叶酸受体介导,从而特异性地靶向于叶酸受体阳性肿瘤细胞的.     

苯乙酸月桂醇酯在青霉素发酵中的应用研究

目的:研究苯乙酸月桂醇酯作为前体对青霉素发酵过程中菌体本身和发酵单位的影响。方法:在摇瓶试验中用苯己酸月桂醇酯代替原工艺所用苯乙酸钠作为前体及补料用,在相同条件下与原工艺对照比较,进行考察研究。结果:苯乙酸月桂醇酯部分代替笨乙酸钠更有利于菌体的生长及提高发酵单位。结论:苯乙酸月桂醇酯可作为青霉素发酵的前体应用,效果更好。     

工程菌Ec108（pPAHD1）青霉素酰化酶表达水平的研究

用2 L 全自动发酵罐观察 Ec 108(pPAHD 1)青霉素酰化酶基因的表达,发现对数前期生物量扩增时,溶解氧以相对饱和度≥80%为宜,而产酶阶段则要求相对饱和度约为5%。应根据溶氧曲线变化特征指导诱导剂苯乙酸的补加时机和剂量,以每次补加0.03～0.05%为佳。在罐压29 kPa、通气比1:0.5的恒温条件下,借助上述手段,可使最高酶活水平达342u/100 ml(NIPAB 法),比摇瓶发酵提高1.8倍。     

Visuocortical epileptiform discharges in rabbits: Differential effects on neuronal development in the lateral geniculate nucleus and superior colliculus

We have studied the effects of interictal epileptiform discharges originating from the striate cortex on the development of the receptive field characteristics of neurons in the lateral geniculate nucleus (LGNd) and superior colliculus (SC) in neonatal rabbits. The paroxysmal discharges were generated by twice-daily injections of penicillin into an implanted cannula. Control injections of penicillin + penicillinase were given to the other striate cortex of the same animal. Similar experimental procedures were used to study the effect of such projected discharges on the LGNd neurons in adult rabbit.The results of the first experiment show that cortical epileptiform discharges, initiated in neonatal rabbits 7–9 days of age and continuing to 20–25 days of age, retard the normal development of LGNd cells. There was an abnormal increase of indefinite cells, cells failing to respond to any light stimulation, and a concurrent decrease of cells with concentric or uniform receptive fields. The second experiment shows that the effect of such interictal discharges is age-dependent; they did not cause any changes on the receptive fields of LGNd cells in adult rabbit. That these epileptiform discharges, occuring early in life, had long-lasting effects is demonstrated in the third experiment. An abnormal increase of uniform cells and a concurrent decrease of concentric cells was still present in adult rabbits which had interictal discharges in the striate cortex limited to the period of 7–9 dats to 21–25 days of age. The fourth experiment shows that the interictal discharges in neonatal rabbits do not affect the normal receptive field development of neurons in the SC.The present results demonstrate that asymptomatic interictal epileptiform discharges, produced without focal structural damages in immature brain, can affect the development of neuronal connectivity. These results may have some clinical implications in relation to our understanding about the learning and developmental disabilities exhibited in children who had episodic seizure discharges.     

EEG monitoring of focal lesions of the blood-brain barrier

This paper presents a modified method for the EEG detection and monitoring of small focal blood-brain barrier (BBB) lesions. The method uses high dose IV penicillin (1.2 x 10⁶μ/kg) to produce a spike focus at BBB lesions, penicillin encephalopathy. The EEG is recorded and the epileptic spikes are counted by an automatic computer program. The computer counting produces an objective quantitative result. The method is verified empirically on traumatic and radiation BBB lesions.     

Antibiotic granules for reconstitution as syrups: product uniformity and stability dependent upon reconstitution procedure

The penicillin content and stability of diluted antibiotic syrups, prepared according to the manufacturers' recommendations and other, non-approved, methods have been investigated. Methods which involve portioning the granules before reconstitution are hazardous and may result in preparations which range from very little antibiotic content to a double strength preparation. The choice of diluent controls the stability of the preparation. Phenoxymethylpenicillin syrups become less stable as the sucrose content increases. This is not always true with ampicillin syrups where the system is more complex. Although syrups prepared according to the manufacturers' instructions are not always the most stable, the effect of different diluents on the stability of syrups, especially suspensions, suggests that syrups should always be reconstituted and diluted according to the directions provided with the product.