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Biomedical subjects

M Takayanagi

Publications and source records attributed to M Takayanagi.

At least 145 records · Page 8Linked to original sources

Some factors affecting isolation of Clostridium tetani from human and animal stools.

Clostridium tetani was isolated from human and animal stools at the following rates [95% confidence interval (CI)]: Human, 0% (1.5-0); horse, 1% (5-0); cow in cowshed, 4% (10-1); cow in pasture, 8.3% (17-1), calf in pasture, 0% (7-0); dog, 2% (11-0) and sheep in pasture, 25% (44-14). Quantification of C. tetani in 16 animal stools positive for the bacillus was impossible in most cases, as the number of tetanus bacilli present was not large enough for this purpose. Contaminating anaerobic and facultative anaerobic bacteria in human and animal stools, i.e., C. perfringens and Streptococcus sp., Group G, inhibited isolation of C. tetani from these materials, particularly at the step of isolation employing its swarming character.

Adult↗

Ornithine transcarbamylase deficiency in spf and spf-ash mice: genes, mRNAs and mRNA precursors.

Two ornithine transcarbamylase-deficient mice are available, the spf with a variant enzyme and spf-ash with a markedly decreased enzyme protein. Genomic DNA, mRNA and the nuclear precursors for the enzyme in these mutants were analyzed. Southern blot analysis of genomic DNA showed no abnormality in the mutant mice. Blot analysis of hepatic mRNA revealed a slight decrease (67% of control) in spf and a marked decrease (12% of control) in spf-ash; no difference in size was found among the control and the mutant mice (about 1.8 kb). Blot analysis of nuclear mRNA precursors (greater than 25, approximately 9.0 and 4.0 kb) showed no significant difference in size and amount among the control, spf and spf-ash. These results suggest that ornithine transcarbamylase deficiency in the spf-ash results from a mutation, which to some extent affects mRNA processing.

Animals↗

DNA polymerase activities in human placenta.

Activities of DNA polymerase alpha and beta were assayed in crude extracts prepared from human placenta. Polymerase alpha activity was high in early pregnancy but low during the 2nd trimester. Polymerase beta activity did not change significantly with gestational weeks. The increase in polymerase alpha activity in early pregnancy may be closely related to mitosis at the time of placental formation; there might also be some type of accelerating factor for polymerase in early pregnancy.

Centrifugation, Density Gradient↗

Molecular aspects of urea cycle enzymes and related disorders.

Amino acid sequence of rat ornithine transcarbamylase (OTC) precursor containing an NH2-terminal presequence of 32 residues was deduced from the cDNA sequence. Comparison with the human and Escherichia coli enzymes indicated that regions containing the putative binding sites for the substrates are highly conserved among the three species. cDNA clones for rat and human liver arginase were isolated and predicted amino acid sequences were compared with that of the yeast enzyme. There are several regions highly conserved among the three species which may be important for catalysis. Several cases of carbamyl phosphate synthetase I and OTC deficiencies were analyzed for enzyme activity, enzyme amount and mRNA activity.

Amino Acid Metabolism, Inborn Errors↗

Colonization of the intestinal tract of mice with Clostridium tetani.

Colonization of intragastrically inoculated Clostridium tetani in intestinal tract of mice was investigated by cultivation of daily stool samples and quantification of the bacilli over a period of 3 weeks. We found that most of the inoculum was excreted in the stool during the first 24 hr. The amount of C. tetani recovered on the second day after inoculation was very small. C. tetani apparently thrived in the intestinal tract when more than 6 log colony forming units (CFU) of tetanus spores had been inoculated. Otherwise, C. tetani colonized poorly in intestinal tract. Tetanus toxin was not detected in the stool nor in the contents of the small and large intestines 24 hr after 6.23 log CFU of tetanus spores had been inoculated. We concluded that the intestinal cavity of mouse is not a favorable environment for colonization of C. tetani under natural conditions.

Animals↗

Density and distribution of Clostridium tetani in the soil.

Clostridium tetani or its toxin was recovered from a minute amount of soil samples collected on the surface of the ground of various places. C. tetani was recovered from 10% and tetanus toxin alone from another 1% of soil samples employing 1 mg of the soil. C. tetani or its toxin alone was recovered, employing 1 mg or more of soil, from the wet shores of ponds and rivers, fields and rice fields (85%), the yards of farmers and non-farmers (53%), school and hospital grounds (30%) and on the roadside (20%). Two tetanus patients were injured in their yards where 1 mg soil samples yielded C. tetani. 12 of 13 soil samples collected at the yard of one of these patients at 3 different times yielded C. tetani. C. tetani did not remain at the same place in the same quantity. It was isolated more readily from the soil samples collected on the surface of than deep in the ground.

Clostridium tetani↗

[Ultrasonographic studies on endometrial carcinoma].

Pre-operative ultrasonographic examinations on endometrial carcinoma were carried out in 34 cases in Tokushima University Hospital for 9 years since 1976. The results were compared with post-operative histological findings. The cancer mass was seen as higher echoic part than normal myometrium and its characteristic echo patterns were grouped into 5 types (4 cases of anechoic, 3 of linear, 4 of cystic, 14 of small mass and 9 of large mass). Small and large mass types were seen in 86% of the cases whose cervix, pelvic lymph nodes or parametrium were involved. The degree of myometrial invasion could be estimated by measuring the thickness of the myometrial echo uninvolved, and its coefficient correlation was 0.65. Depending on the increase in tumor echo size, myometrial invasion sometimes developed more deeply. Cervical involvements were estimated accurately in 86% by ultrasonography. Ultrasonographic estimation of the invasion on endometrial carcinoma was thought to be useful.

Adult↗

Effect of aggregation state of hard segment in segmented poly(urethaneureas) on their fatigue behavior after interaction with blood components.

Characterization of microphase separated structure, interaction with blood components, such as lipids, and fatigue behavior after immersion in blood components were carried out for segmented poly(urethaneureas). The materials studied were Biomer and segmented poly(urethaneurea) (TU-Mn) composed of hard segment with 4,4'-diphenylmethane diisocyanate (MDI)-ethylenediamine (EDA) or 4,4'-diaminodiphenylmethane (DAM) and soft segment with MDI-polytetramethylene glycol (PTMG) [Mn of 856, 1350, and 2000]. Small-angle x-ray scattering, wide-angle x-ray diffraction, and dynamic viscoelastic measurements revealed that these materials showed the state of microphase separation. TU-Mn with PtMG of Mn = 856 shows the partial phase mixing between hard and soft segments, and phase separation was improved with an increase of Mn of PTMG. Biomer has the characteristics of stronger aggregation of hard segment than that of TU-Mn. All the specimen showed lipid absorption, but the amount of absorption decreased remarkably after precoating on the specimen surface with serum albumin. Lipid absorption of the specimen was confirmed by dynamic viscoelastic and IR measurements. In the case of segmented poly(urethaneurea) which did not immersed in lipids solution, their fatigue strength are sufficient for application to artificial heart systems. However, fatigue strength of the TU-Mn series was decreased drastically after absorption of lipids. On the other hand, Biomer did not show a decrease of fatigue strength after lipid absorption. The reduction of fatigue strength in the TU-Mn series after lipid absorption will be attributed to the weak aggregation of hard segment domain. This reduction of fatigue strength in the TU-Mn series is characterized by formation of microcrack and mirror zone in fatigue fractured specimen. As the precoating of the specimen surface with serum albumin inhibits the absorption of lipids, the reduction of fatigue strength was not observed for the specimen precoated with serum albumin even after immersing the TU-Mn series in lipids solution for 96 days.

Absorption↗