We developed new sandwich cup method to assay the penetration of various antimicrobial agents through Pseudomonas exopolysaccharides. Using alginate extracted from mucoid‐type Pseudomonas aeruginosa and gellan gum from Pseudomonas elodea, the role of exopolysaccharides as a barrier against drug penetration was examined. The penetration of positively charged hydrophilic drugs such as aminoglycosides and polypeptides was markedly inhibited by the gels tested, but that of β‐lactams, quinolones, and macrolides was not inhibited. The penetration of gentamicin was strongly influenced by the gel concentration, the solution to be used, and the presence of Ca2+. These results suggest that the microenvironment at the infection site could greatly influence drug penetration through biofilms in vivo.
We studied the heat resistance and the range of growth temperature 0 gram-negative rods to find one of the bacterial factors governing their infectivity in exogenous and endogenous infections in predisposed patients.Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa, and Acinetobacter calcoaceticus grew equally well at 25, 30, 37, and 42 C. Among other sugar non-fermenting gram-negative rods, six species showed suppressed growth at either or both ends of the incubation temperature range. All the bacterial species tested were killed within 30 min at 60 or 70 C. At 10 C, none of the bacterial strains multiplied, but all survived for 6 hr.Of 17 bacterial species tested, E. coli had the widest range of growth temperature (18-47 C), and also the shortest time necessary for growth to a certain population. Among the sugar non-fermenting rods, A. calcoaceticus had the widest range of growth temperature (20-45 C) and also multiplied rapidly. Pseudomonas strains exhibited slower growth at all temperatures and also had a narrower range of growth temperature than Enterobacteriaceae. Among Pseudomonas species, P. aeruginosa had the widest range of growth temperature (25-42 C) and also showed rapid growth. Pseudomonas cepacia, Achromobacter xylosoxidans, and ALcaligenes faecalis had a narrow range of growth temperature (28-37 C), and Pseudomonas fluorescens, Flavobacterium meningosepticum, and Moraxella grew most rapidly at 30 C.The above results are correlated fairly well with the incidence of clinical cases of infection. The growth attitude of a species of bacteria in response to temperature was considered to be one of the factors affecting the establishment of infection.
Rapid and slow inactivators of isoniazid are homozygotes, and intermediate inactivators are heterozygotes. There is no dominance between the two alleles. The chasm between Eskimos and Caucasians in isoniazid metabolism is bridged by our investigation of the races in the Far East.
Excessive dietary phosphorus (P) has been speculated to be a risk factor for cardiovascular disease (CVD). Here, we performed a double-blinded crossover study to investigate the time- and dose-dependent effects of dietary P intake on endothelial function in healthy subjects. Sixteen healthy male volunteers were given meals containing 400, 800, and 1,200 mg P (P400, P800, and P1200 meals, respectively) with at least 7 days between doses. There were no differences in nutritional composition among the experimental diets except for P content. Blood biochemistry data and flow-mediated dilation (%FMD) of the brachial artery were measured while fasted, at 0 h, 1 h, 2 h, and 4 h after meal ingestion, and the next morning while fasted. The P800 and P1200 meals significantly increased serum P levels at 1-4 h after ingestion. A significant decrease in %FMD was observed between 1-4 h,while the P400 meal did not affect %FMD. We observed no differences among meals in serum P levels or %FMD the next morning. A significant negative correlation was observed between %FMD and serum P. These results indicate that excessive dietary P intake can acutely impair endothelial function in healthy people.
The Gallyas method is a silver impregnation technique that is essential in the field of neuropathology because of its high sensitivity for the detection of argentophilic inclusion bodies in the central nervous system. In Japan, the Gallyas method has improved and is widely used as the “modified Gallyas method”. However, this method is not popularly used in general pathology laboratories because of the need for special reagents, several staining processes, and skilled techniques. The objective of the current study was to provide a simplified Gallyas method. We omitted the lanthanum nitrate step from the staining process and verified the adequacy in comparison with the original method as well as immunohistochemistry, using specimens from patients of Alzheimer's disease, argyrophilic grain disease, multiple system atrophy, Pick's disease, and Lewy body disease. The simplified method provided good staining to all the structures in archival tissues, compared with the modified Gallyas method in a significantly shorter staining time. The lanthanum nitrate step can be omitted from the modified Gallyas method, resulting in reduction in the number of reagents required and shortening of the staining time.
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