Monobactam antibiotics in subinhibitory concentrations enhance opsonophagocytosis and serum bacteriolysis in certain Escherichia coli strains

Capsular polysaccharides are known to protect Gram-negative bacteria from complement-mediated killing and opsonophagocytosis. Monobactam antibiotics selectively inhibit penicillin-binding protein 3 (PBP3), resulting in abnormally structured peptidoglycan, causing defective cell surface structures. The authors studied the influence of subinhibitory concentrations of the monobactam antibiotics aztreonam and carumonam on serum bacteriolysis and opsonophagocytosis of four K-encapsulated and five non-K-encapsulated Escherichia coli strains. It was observed that monobactam antibiotics in subinhibitory concentrations enhanced opsonophagocytosis of the four K-encapsulated and one non-K-encapsulated E. coli strains tested. Opsonophagocytosis of the other four non-K-encapsulated E. coli strains was not enhanced. Serum bacteriolysis studies revealed that of the four K-encapsulated strains tested only one strain showed a significant enhancement of bacteriolysis after treatment with subinhibitory concentrations of monobactam antibiotics. None of the unencapsulated strains showed a significant change in percentage lysis after treatment with either aztreonam or carumonam.     

高能重离子的生物学效应初探

为研究高能重离子对高等植物种子的影响，用核径迹探测器与药用植物干种子复合制成生物叠的方法，在卫星搭载实验中，初步探查了空间环境对莨菪和藿香的生物学效应，发现单纯失重因素对当年栽培的植株无显著影响，但被高能重离子击中的种子经３个月储存后，其栽培的植株长势有明显增快，开花和结实时间也早于对照组，但染色体凶有损伤或变异。确认这种方法能较精细地鉴别空间环境中持续失重和高能重离子击中两个因素的生物学效应，是     

MM 14201, a new epoxyquinone derivative with antibacterial activity produced by a species of Streptomyces

A new antibiotic designated MM 14201 has been detected in a culture of Streptomyces sp. NCIB 11813. Methods for the production and purification of MM 14201 are described. Biological evaluation has shown it has broad spectrum antibacterial activity being most effective against Serratia and Pseudomonas sp. Structural studies are reported which have demonstrated MM 14201 is a new epoxyquinone derivative.     

Haemoccult compliance rates and reasons fornon-compliance

Bowel cancer is the second commonest malignancy in England and Wales. Mortality fromthis condition has remained constant over the last 30 years. At present there is the suggestion that screening will result in fewer deaths. The only practicable method is by use of the Haemoccult test, but compliance to this test is a major problem.This study looked at compliance rates in two G.P. practices. Use of the kit and return of specimens was higher when the kit was sent through the post than when individuals were invited to collect it themselves. Women and individuals in the younger age group were more likely to comply.When non-compliers were interviewed the most frequent reasons given for not usingthe test related to the unpleasant nature of faeces or the lack of time needed to complete the test. Many people also gave reasons which could be described as having little understanding of the principles or value of pre-symptomatic screening.     

The effect of ablating the habenular nucleus of rats recovered from lesions of the lateral hypothalamus

Four to six weeks after recovery of feeding following lateral hypothalamic lesions, bilateral lesions were made in the habenular nuclei of rats. Although a transient hypophagia was observed in some animals, none showed aphagia or adipsia. This study indicates that the habenular nucleus is not a crucial part of the feeding system which mediates the recovery from aphagia shown by rats with lateral hypothalamic lesions.     

Properties of MM 13902 and other carbapenem antibiotics in vitro and in vivo

The carbapenem antibiotics, which include the olivanic acids and the thienamycins, have a broad-spectrum of antibacterial activity but only thienamycin itself shows appreciable activity against Pseudomonas aeruginosa. The zwitterionic nature of thienamycin was reproduced in the olivanic acid series by preparing the deacetyl derivatives of MM 17880 and MM 22380--compounds NA 26975 and NA 26978. The latter derivative showed antipseudomonas activity and had an antibacterial spectrum similar to thienamycin itself. In contrast the O-sulfated analogue, NA 26975, was no more active than the parent compound against P. aeruginosa. Both deacetyl compounds were more stable than the parent natural products to a mouse kidney enzyme preparation and gave higher urinary recoveries in the mouse. Pharmacokinetic studies with MM 13902 in various animal species showed that the compound was rapidly eliminated from the blood and gave only low urinary recoveries. Similar findings were observed also in human volunteers given MM 13902. The nephrotoxicity reported for thienamycin/MK 0787 in the rabbit was not seen with the olivanic acids MM 13902, MM 17880, MM 22382 and MM 22383 when tested under the same conditions.