Antibiotics in surgical treatment of acute abscesses.

A four-way, double-blind, prospective trial of treatment of abscesses by incision, curettage, and primary closure with and without antibiotic cover (clindamycin injection before operation or capsules after operation, or both) was conducted. There was no appreciable difference in mean healing time between the patients given both the antibiotic injection and the antibiotic capsules and those given the injection and placebo capsules, whereas healing times in those given the placebo injection and antibiotic capsules or placebo only were appreciably longer. Four of the patients who were not given the antibiotic injection developed bacteraemia; one patient who was given the antibiotic injection also developed a bacteraemia, but this was caused by clindamycin-resistant bacteria. These results show that a single injection of an effective antibiotic before operation is sufficient to protect the patient against bacteraemia and permit optimum healing.     

Presence of a small plasmid in clinical isolates of Streptococcus pneumoniae

Twenty-four of 63 enteric Gram-negative organisms (38.1%) which were isolated from 35 apparently healthy Nigerian students were found to have low trimethoprim resistance (MIC less than 1000 mg/l). These isolates were also found to be resistant to several other antibiotics and trimethoprim resistance was found to be transferable from 15 (62.5%) of the trimethoprim resistant organisms into E. coli EC 1005. It is likely that the high percentage of trimethoprim resistance encountered in this study is related to the high rate of resistance transfer which was observed.     

Metabolism of caffeine by mouse liver microsomes: GSH or cytosol causes a shift in products from 1, 3, 7-trimethylurate to a substituted diaminouracil

Incubation of [¹⁴C] caffeine with hepatic microsomes from male AKR/J mice resulted in the formation of several metabolites including 1, 3, 7-trimethylurate and 6-amino-5-(N-formylmethyl-amino)-1, 3-dimethyluracil. These two compounds comprised about 60% of products and are major urinary metabolites in several animals. When cytosol was included during incubation, there was a 14-fold increase in yield of the uracil at the expense of the urate; the combination of the two metabolites remained about 60% of total products. Cytosol alone was catalytically inert. Glutathione and other sulfhydryl compounds reproduced the effect of cytosol, and the action of cytosol was accounted for quantitatively by its sulfhydryl content. We propose that an oxidized intermediate of caffeine en route to trimethylurate is reduced by glutathione to the ring-opened uracil derivative.     

Type I Antifreeze Proteins Enhance Ice Nucleation above Certain Concentrations

In this study, we examined the effects that antifreeze proteins have on the supercooling and ice-nucleating abilities of aqueous solutions. Very little information on such nucleation currently exists. Using an automated lag time apparatus and a new analysis, we show several dilution series of Type I antifreeze proteins. Our results indicate that, above a concentration of ∼8 mg/ml, ice nucleation is enhanced rather than hindered. We discuss this unexpected result and present a new hypothesis outlining three components of polar fish blood that we believe affect its solution properties in certain situations.