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Biomedical subjects

K Tsuji

Publications and source records attributed to K Tsuji.

At least 811 records · Page 45Linked to original sources
PubMed1978

Dry-heat destruction of lipopolysaccharide: design and construction of dry-heat destruction apparatus.

A dry-heat oven with automatic, multiple-sample introduction and withdrawal has been constructed to achieve instantaneous heating and cooling of samples. The oven temperature fluctuation at set points of 170 to 250 degrees C was +/- 0.1 degrees C, with temperature variation between the replicate samples of +/- 0.2 degrees C. Correction required for a sample come-up time was minimal, i.e., less than 0.25 min of the dry-heat destruction time.

Hot Temperature↗
PubMed1978

Dry-heat destruction of lipopolysaccharide: dry-heat destruction kinetics.

Dry-heat destruction kinetics of lipopolysaccharides from Escherichia coli, Serratia marcescens, and Salmonella typhosa at 170 to 250 degrees C are described. The destruction rate seems to follow the second order and can be linearized by the equation, log y = a + b . -10cx. Because c is the slope, 1/c = D3. Both a and b are constant at a given temperature and are linear functions of temperature. The D(3)170, D(3)190, D(3)210, D(3)230, and D(3)250 values for E. coli lipopolysaccharide are 251, 99.4, 33.3, 12.3, and 4.99 min, respectively, with a z value of 46.4 min. The D values for lipopolysaccharides from S. marcescens and S. typhosa are not significantly different from those from E. coli lipopolysaccharide.

Escherichia coli↗
PubMed1978

Dry-heat destruction of lipopolysaccharide: mathematical approach to process evaluation.

A mathematical model was developed to estimate the number of logarithmic cycles (LDec) of lipopolysaccharide concentration destroyed by a dry-heat sterilization process. The LDec values calculated from the mathematical model agreed well with those obtained from the destruction of lipopolysaccharide by a dry-heat treatment. A discussion of how the mathematical model may be used to evaluate a dry-heat sterilization cycle is presented. This mathematical model and the dry-heat destruction curves indicated existence of a maximum LDec value at each temperature. The implications of this finding are discussed.

Escherichia coli↗
PubMed1978

HPLC as a rapid means of monitoring erythromycin and tetracycline fermentation processes.

Reverse phase high performance liquid chromatography (HPLC) was used as a rapid means of monitoring the erythromycin and the tetracycline fermentation processes. The sample preparation process for tetracycline in the fermentation broth includes simple dilution and filtration through a Millipore filter prior to injection into the HPLC column. Fermentation growth samples showed no interference, and excellent separation for selective determination of tetracycline, 4-epitetracycline, anhydrotetracycline, chlortetracycline, and 4-epianhydrotetracycline was obtained. The relative standard deviation for the HPLC analysis for tetracycline is about one percent and the correlation coefficient between the HPLC and the spectrophotometric assay methods is better than 0.994. The sample preparation procedure for erythromycin determination in fermentation broth requires solvent cleanup and extraction processes. The chromatographic analysis takes approximately 25 minutes, and the HPLC method is capable of separating and quantifying erythromycins A, B, C, and various epimers and degradation compounds. The correlation coefficient between the HPLC and the microbiological assay method is 0.970.

Biological Assay↗
PubMed1978

Chromosome studies of embryos from induced abortions in pregnant women age 35 and over.

Chromosome studies of embryos were done in abortions induced at the early stage of pregnancy in women 35 years of age and older who had no signs of threatened or spontaneous abortions and were considered to have oocytes of an advanced age. Karyotypes were successfully determined in 256 cases and the results were as follows: a) 2 of 123 cases in 35- to 39-year-old women showed an incidence of chromosomal anomalies as high as 1.6%; 7 of 117 cases in 40- to 44-year-old mothers an incidence of 6.0%; and 4 of 16 mothers in the 45- to 49-year-old age group an incidence of 25.0%; b) all chromosomal anomalies were trisomies, mainly trisomy 21 and 18. These results suggest that the incidence of chromosomal anomalies increases in older pregnant women, especially in premenopausal pregnancies, and that non-disjunction may occur during meiosis.

Abortion, Induced↗
PubMed1978

HLA antigens in Kawasaki disease.

Two hundred five patients with Kawasaki disease and 500 normal controls were HLA-typed, using a standard microcytotoxicity test of tissue typing. HLA-BW22 was more common in patients with Kawasaki disease than in normal controls (25.4% instead of 11.8%, corrected P less than .0005). Among subtypes of HLA-BW22 antigen, Kawasaki disease was associated with HLA-BW22J2, which was found specifically in Japanese and not in Caucasians. These facts may suggest that there is a gene controlling the susceptibility to Kawasaki disease and linked with a Japanese-specific HLA antigen.

Child↗