Isolation and characterization of a penicillinase from Pseudomonas cepacia 249.

Pseudomonas cepacia has an inducible beta-lactamase which is responsible for its novel ability to catabolize beta-lactam compounds. The gene encoding this enzyme, penA, was cloned from a genomic library of P. cepacia 249 on the broad-host-range cosmid pLAFR. This separated the penA gene from the gene encoding a second beta-lactamase in P. cepacia 249. Expression of penA was inducible in an Escherichia coli host strain by low levels of penicillin. The 33,500-molecular-weight enzyme had penicillinase activity not inhibited by clavulanic acid or sulbactam and was highly active against piperacillin and azlocillin. In comparison with other inducible beta-lactamases produced by gram-negative organisms, the penA enzyme had many properties which were similar to those of the penicillinase produced by Alcaligenes faecalis. It was unlike the ampC-type cephalosporinase produced by Pseudomonas aeruginosa.     

Childhood convulsive status epilepticus: epidemiology, management and outcome

Convulsive status epilepticus (CSE) in childhood is a medical emergency and its aetiology and outcome mean that it should be studied separately from adult CSE. The incidence in developed countries is between 17 and 23/100,000 with a higher incidence in younger children. Febrile CSE is the commonest single group with a good prognosis in sharp distinction to CSE related to central nervous system infections which have a high mortality. The aim of treatment is to intervene at 5 min and studies indicate that intravenous (i.v.) lorazepam may be a better first-line treatment than rectal diazepam and i.v. phenytoin a better second-line treatment than rectal paraldehyde. An epidemiological study strongly supports the development of prehospital treatment with buccal midazolam becoming a widely used but unlicensed option in the community. More than two doses of benzodiazepines increase the rate of respiratory depression without obvious benefit. The 1 year recurrence rate is 17% and the hospital mortality is about 3%.     

Chinese nutrition educational materials for renal patients.

Nutrition resources in Chinese have been developed for the patients in St. Paul's Hospital's Renal Program. The goal was to support this patient subgroup to understand and practice the complicated diet guidelines within their own language and cultural contexts.     

Retinopathy in hepatitis C patients due to combination therapy with pegylated interferon and ribavirin

Background  

To assess the nature, incidence, and risk factors of retinopathy associated with pegylated interferon and ribavirin combination therapy in chronic hepatitis C patients.     

Idiopathic hypereosinophilic syndrome with polymyositis

We have reported a case of idiopathic hypereosinophilic syndrome (HES) with polymyositis, in which there was marked eosinophilic leukocytic infiltration of the myocardium and striated skeletal muscles, particularly of the diaphragm, with foci of necrosis and areas of fibrosis. We believe this to be the first detailed report of the involvement of the diaphragm in HES.     

Flow Cytometric Analysis of Cellular Changes in Mice after Intradermal Inoculation with a Liposome–Iscom Adjuvanted Vaccine

As it is not known what changes to leucocyte homeostasis are mandatory for effective adjuvant action, the biological relevance of systemic changes elicited by different vaccine formulations can only be interpreted in the context of the immunological outcomes. We used flow cytometry to quantify the changes in leucocyte subsets induced in mice intradermally immunized with SAMA4 (adjuvant group), outer membrane proteins (OMP) purified from Actinobacillus pleuropneumoniae (OMP antigen group), SAMA4 adjuvanted OMP (OMP vaccine group), or phosphate-buffered saline (PBS: control group). This approach allowed direct comparisons to be made between the effects of antigen, adjuvant or antigen–adjuvant complexes on immune effector cell populations. Antigens complexed with the liposome–iscom hybrid adjuvant, SAMA4, generated strong antibody responses and cytotoxic T-cell activity in animals immunized intradermally, reflecting remobilization and recruitment of specific cell populations. Splenomegaly, due to granulocytosis, monocytosis and megakaryocytosis, was most prominent in the OMP vaccine group. Histological examination of spleen sections confirmed that these changes were due primarily to splenic haematopoiesis. Circulating numbers of granulocytes and monocytes increased significantly (P < 0.05) in the blood of the OMP vaccine group, as did granulocyte numbers in the lungs (P < 0.05). No changes in T- and B-cell numbers were detected by flow cytometry in the spleens, lungs or blood over the 28-day period in any treatment group. Thymocyte numbers (predominantly CD4⁺CD8⁺ cells) in the OMP vaccine group fell by 95% within 3 days of immunization. Identical cellular responses were obtained when an innocuous antigen, ovalbumin, was complexed with SAMA4 instead of OMP, thus demonstrating that the adjuvant effects of SAMA4 were due to synergistic interaction between antigen and adjuvant and not due to the presence of toxic components. The association of strong adaptive immune responses with such complex changes in leucocyte homeostasis induced by complexing adjuvant and antigen suggested that the changes were important for effective vaccination and were not purely circumstantial.     

以酶解法从中药及药渣制备β—葡萄糖的研究

本实验首次将工业纤维素酶应用于中药及药渣中，探讨利用工业纤维素酶使中药及药渣的纤维素酶解为β－葡萄糖；实验结果表明：在５０℃，ｐＨ４．５，底物浓度为１５％的条件下，４８小时可酶解得５％以上的β－葡萄糖。     

Increases in plasma beta-endorphin concentrations during exercise do not contribute to increases in heart rate following autonomic blockade in man.

1. Intrinsic heart rate (IHR: heart rate following autonomic blockade with atropine and propranolol) increases with exercise. The opioid antagonist naloxone has been shown to decrease IHR at rest, raising the possibility that increases in IHR with exercise are beta-endorphin related, since beta-endorphin concentrations have also been shown to rise during exercise. 2. We examined the effects of naloxone (10 mg) on IHR and plasma beta-endorphin levels during aerobic exercise in eight healthy, male subjects in a single blind, crossover study. 3. IHR increased with 25 min bicycling from 97.1 +/- 1.4 to 129.7 +/- 1.2 beats min-1 (mean +/- s.e. mean). This rise was not affected by administration of naloxone. 4. Plasma beta-endorphin concentration rose from 31.1 +/- 3.8 to 94.9 +/- 23.9 pg ml-1 after 25 min exercise. This exercise-induced rise in beta-endorphin concentration was further increased (P less than 0.05) in the presence of naloxone. 5. Our results confirm a rise in IHR and beta-endorphin concentrations with acute exercise but indicate that the changes in IHR are not endorphin-related.     

早期自体角膜缘移植术治疗碱烧伤

目的探讨角膜缘移植术在眼碱烧伤中的治疗意义。方法新西兰兔１４只，１．０ｍｏｌ／ＬＮａＯＨ溶液眼前节烧伤１分钟。其中７只兔于烧伤后即实施自体角膜缘移植术，另７只兔为对照。术后观察１个月，取其角膜进行光镜及扫描电镜观察。结果手术组角膜上皮愈合快，角膜新生血管及角膜炎细胞浸润均较对照组轻。结论早期自体角膜缘移植术治疗碱烧伤可加速角膜上皮愈合、抑制角膜新生血管形成、减轻角膜炎症反应及预防角膜溃疡的发生。     

Oral immunization of mice with attenuated Salmonella typhimurium aroA expressing a recombinant Mycoplasma hyopneumoniae antigen (NrdF).

Mycoplasma hyopneumoniae is the etiological agent of porcine enzootic pneumonia, a commercially expensive respiratory disease of swine. Salmonella typhimurium SL3261 was used as a live carrier of plasmid pKF1, which encodes a 15-kDa recombinant M. hyopneumoniae protein. This expressed recombinant protein consists of the carboxy-terminal 11 kDa of a 42-kDa M. hyopneumoniae NrdF ribonucleotide reductase R2 subunit protein. Rabbit anti-15-kDa serum was able to inhibit the growth of viable M. hyopneumoniae J in vitro. When used as a live oral vaccine, S. typhimurium SL3261(pKF1) induced a significant secretory immunoglobulin A immune response in the lungs of mice orally immunized against the M. hyopneumoniae antigen. Utilization of live oral vaccines expressing potentially protective M. hyopneumoniae proteins, such as the NrdF antigen, which can stimulate a lung mucosal response against surface-accessible proteins may provide a cost-effective alternative to the present control strategies used for porcine enzootic pneumonia.