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Biomedical subjects

K Ohwada

Publications and source records attributed to K Ohwada.

At least 37 records · Page 2Linked to original sources
PubMed1997

16S rDNA genotyping using PCR/RFLP (restriction fragment length polymorphism) analysis among the family Vibrionaceae.

The 16S rDNA genotypes among the family Vibrionaceae were determined using PCR/RFLP analysis. Five tetrameric restriction enzymes (HhaI, DdeI, RsaI, Sau3AI and MspI) were used for RFLP analysis and adequate numbers of informative bands were obtained from each enzyme. Twenty-seven genotypes were obtained from 49 type and reference strains including 35 species. Nineteen species could be assigned to specific 16S rDNA genotypes, supporting the application of this analysis for identification. Trees constructed using five endonucleases resolved groups almost identical to those inferred from 16S rRNA gene sequencing. However, the branch lengths and detailed relationships among strains within a group differed from those inferred from sequence comparisons. The results of this study should be useful for genotyping, identification and approximate classification of natural isolates belonging to the family Vibrionaceae.

Base Sequence↗
PubMed1996

Suplatast tosilate, a new type of antiallergic agent, prevents the expression of airway hyperresponsiveness in guinea pigs.

Suplatast tosilate (suplatast) is an antiallergic agent capable of down-regulating the functions of CD4+ T cells. We now investigated the effects of suplatast on the antigen-induced airway hyperresponsiveness and the underlying allergic inflammatory response in sensitized guinea pigs. Animals that had been immunized twice by ovalbumin inhalation on day 0 and day 7 developed an increased airway responsiveness against inhaled acetylcholine 24 h after the ovalbumin challenge on day 14. Suplatast (10 and 100 mg/kg per day) and ketotifen (10 mg/kg per day) given orally from day 0 to day 14 effectively inhibited the expression of airway hyperresponsiveness. They also inhibited the infiltration of eosinophils and macrophages into broncho-bronchiolar walls and lumen. Interestingly, suplatast, but not ketotifen, inhibited the infiltration of lymphocytes including CD4+ T cells. Collectively, these results strongly suggest that suplatast prevents the expression of airway hyperresponsiveness due to the ability to suppress the infiltration of inflammatory cells into lung tissues.

Animals↗
PubMed1996

A biological method for the quantitative measurement of tetrodotoxin (TTX): tissue culture bioassay in combination with a water-soluble tetrazolium salt.

A tissue culture bioassay, using the mouse neuroblastoma cell line (Neuro2A), was improved to provide a simple and sensitive bioassay for TTX or sodium channel-blocking toxins (SCB). The water-soluble tetrazolium salt, 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetraz olium, monosodium salt (WST-1), was applied to replace the time-consuming and subjective cell-counting procedure of the cells with automatic measurement, using a microplate reader. It was also confirmed that this method is directly applicable to bacterial culture supernatants, with the precaution of possible interference.

Animals↗
PubMed1995

Microflora and tetrodotoxin-producing bacteria in a gastropod, Niotha clathrata.

Shellfish (Niotha clathrata) were collected in both July and November from three locations in Taiwan (Pingtung, Kaohsiung and Chiai Prefecture) and assayed for anatomical distribution of tetrodotoxin (TTX) and aerobic heterotrophic bacteria. Pingtung specimens showed higher toxicity than those from Kaohsiung and Chiai, and did not show much seasonal variation. At each site, the total aerobic bacterial counts in November samples were higher than in July. The predominant genera were Vibrio, Pseudomonas, Pasteurella, Aeromonas and Plesiomonas. Vibrio comprised more than 35% of the genera, with V. alginolyticus as the major species. The viable counts of Vibrio species were higher in November than in July. However, the results did not suggest any relationship between the total count or viable count and the toxicity of the shellfish. HPLC, UV and gas chromatographic-mass spectrometric analyses demonstrated that some of the bacteria isolated, such as V. alginolyticus, V. parahaemolyticus, Pseudomonas spp. Plesiomonas sp. and Aeromonas sp., produced TTX and/or related substances.

Animals↗
PubMed1993

Presence of tetrodotoxin and tetrodotoxin-producing bacteria in freshwater sediments.

The occurrence of tetrodotoxin (TTX) in sediment from Lake Suwa, Japan, was confirmed by a tissue culture assay, high-performance liquid chromatography, and gas chromatography-mass spectrometry. Altogether, 17 TTX-producing bacteria belonging to five genera were isolated from Lake Suwa and Pond Inokasira. Our results indicate that TTX and TTX-producing bacteria occur even in freshwater environments.

Journal Article↗
PubMed1993

Reference values for organ weight, hematology and serum chemistry in the female ferret (Mustela putrius furo).

Organ Weight, hematologic and blood chemistry values were determined to establish reference values in the female ferret. Organ weight per kg body weight was calculated for various organs. Body surface area (BSA) was also determined by the direct method, and K values (constant) were calculated. The K value was 3.48 in the Dubois and Dubois equation, and 9.69 in the Meeh-Rubner equation. Blood samples were used to record 10 hematologic and 57 serum (plasma) chemistry values, and 7 immunological parameters. Among hematologic values, values whose coefficient of variation (cv) exceeded 30% were RBC, WBC and PLT. In blood chemistry, the CV of gamma-G, UA, ZTT, GPT, gamma-GTP, MAO, ALD and IgG exceeded 30%. In the total amino acid analysis, only the CV of TAU exceeded 30%. Electrophoretograms of amylase and CPK isozyme were quite different from those of humans. Although 1-MEHIS, 3-MEHIS and CAR have not been detected or are present in trace amounts in human plasma, concrete values were detected in female ferret plasma. Hematologic and serum chemistry values were in general agreement with normal values seen in cats and dogs. However, the alpha 1-G percentage, and ALP and amylase activities were lower than the corresponding values in cats and dogs. The RBC count, RET-C percentage and LDH activities were higher than in cats and dogs. Since there have been no comprehensive articles on reference values for the female ferret, the present report contributes to studies that involve this animal as an experimental model.

Alanine Transaminase↗
PubMed1993

Usefulness of alpha 1 acid glycoprotein (alpha 1-AG) values in screening pound dogs acquired from animal shelters for experimental use.

The usefulness of alpha 1 acid glycoprotein (alpha 1-AG) levels in selecting pound dogs from animal shelters for experimental use, was assessed in 1,013 dogs. The mean (+/- SD), minimum, and maximum alpha 1-AG values were 375.9 (+/- 244.8), 20, and 1,650 micrograms/ml. The alpha 1-AG value exceeded 500 micrograms/ml, the cut-off value for the normal range, in 219 dogs. There was little correlation between alpha 1-AG values and any of 15 blood chemistry parameters or with hematocrit values. Of the 176 dogs that died within 2 weeks after arrival at our institution, the alpha 1-AG concentration was abnormal in one-third. These findings confirm that measurement of alpha 1-AG is extremely useful in identifying desperate dogs and in confirming of the prognosis.

Animal Husbandry↗
PubMed1993

Indirect measurement for body surface area of cotton rats.

The body surface areas (BSAs) of 42 cotton rats (21 females weighing 29.08 to 169.60 g, and 21 males weighing 18.93 to 168.03 g) were measured. From these areas and body weights (BW), the equation, BSA (cm2) = 47.66 + 2.476 x BW (g) -0.006 x BW (g)2, was derived. To verify the applicability of the equation, the BSAs of another 19 animals (12 females weighing 29.08 to 169.60 g, and 7 males weighing 19.27 to 167.32 g) were calculated and the values compared with the measured BSAs. The correlation between calculated and measured BSAs was significant (r = 0.995, P < 0.01). Therefore, this equation can be used to calculate cotton rat BSA.

Animals↗
PubMed1993

Hematological standard values in the cotton rat (Sigmodon hispidus).

The purpose of this study is to establish reference data on several hematological parameters in the cotton rat. Eight hematological values were measured in 28 males and 29 females at 16 to 18 weeks of age. Females showed significantly lower RBC, Ht and MCV values than males. Female Hb and PLT values tended to be lower than male values, although differences did not reach a conventional level of significance. WBC and PLT values varied widely in both sexes.

Animals↗
PubMed1992

Isolation and characterization of Shewanella alga from human clinical specimens and emendation of the description of S. alga Simidu et al., 1990, 335.

Genetic and phenotypic studies on the strains biochemically identified as Shewanella putrefaciens, which had a G+C content ranging from 52 to 54 mol% were conducted. The moles percent G+C of the type strain of S. putrefaciens is 46. Surprisingly, DNA homology experiments revealed that all these strains are genetically related to Shewanella alga (which was reported to produce tetrodotoxin), not to the type strain of S. putrefaciens. In this study, we reidentified clinical strains of S. putrefaciens which have a high range of moles percent G+C, as does S. alga. We also characterized the reidentified strains and found that the original description of S. alga (U. Simidu, K. Kita-Tsukamoto, T. Yasumoto, and M. Yotsu, Int. J. Syst. Bacteriol. 40:331-336, 1990) is insufficient to identify this strain. An emended description of S. alga is given.

Animals↗
PubMed1992

Body surface area of the golden Syrian hamster.

The body surface areas (BSAs) of 30 Syrian hamsters were actually measured. From these areas, the Mass Coefficients (K values) for the Dubois and Dubois equation (5.31) and for the Meeh-Rubner equation (11.89), were computed. These values were independent of weight and sex. To verify the applicability of the Mass Coefficients, the BSAs of another 20 animals were calculated and compared with the actually measured BSAs. The difference between measured and calculated BSAs was not significant. Therefore, these values can be used with their respective equations to compute BSA in Golden Syrian hamsters.

Animals↗
PubMed1991

X-ray photography quality control of auto-watering nozzles.

X-ray photographs were used to analyze auto-watering nozzles for structural defects. Defects were observed in 58% of the nozzles by a water pressure test, and in the majority of these, X-ray films showed that the combined length of the core section spring and packing (L) was greater than 1.81cm, and the spring (S) was Y-shaped. Among those nozzles for which the water pressure test demonstrated no defects, (L) was less than 1.80cm and (S) was in the form of an isosceles triangle. Accordingly, it became evident that there is a close relationship between water leakage and defects in the internal structure and that it is possible to assess the quality of auto-watering nozzles by X-ray photography.

Animal Husbandry↗
PubMed1991

Permanent marking of colored mice using dry ice.

Freeze marking, using dry ice, was successfully applied to colored mice for permanent, individual, identification. By this method, a 5-8 mm piece of dry ice is pressed against the skin of mice for 10 seconds. About 3 weeks after this treatment, spots of white hair growing at the site of treatment became recognizable to the naked eye, and allowed permanent identification of individual animals thereafter. The white spots were very clear in colored mice, and greatly facilitated animal identification as compared to conventional marking methods. Treatment of the animals with dry ice for 10 seconds has no discernible effects on the site of the treatment or the general condition of the animals.

Animal Identification Systems↗
PubMed1989

[Residual coronary artery stenosis: its shapes immediately after thrombolysis and subsequent time courses].

Changes in shape and the time course of residual coronary artery stenoses following thrombolysis were studied in 36 patients with acute myocardial infarction. The following results were obtained: 1. Residual stenoses after thrombolysis were categorized morphologically in three groups; long segment type (group L, eight patients), segmental type (group S, 18 patients) and filling defect type (group FD, 10 patients). 2. Residual stenoses in group L did not change either as to morphology or severity one month later. Group S did not show morphological change, but 11 of the 18 patients showed slight regression of residual stenoses. In group FD, filling defect images on repeated angiography resolved in all cases within one month. However, characteristic irregularity at the infarct-related coronary arteries were often observed at the same time. 3. Twelve of the 36 patients underwent angiography during three consecutive days to study sequential changes in residual stenoses. Intracoronary thrombi were resolved before the second day, which was compatible with a plasminogen-plasmin system change. 4. Severe coronary artery atherosclerosis may be an important factor in the pathogenesis in group L, while thrombus formation based on ulcerative lesions without significant stenoses may be an important factor in group FD. 5. Mechanical revascularization for the groups L and S patients, and an additional thrombolytic agent for the group FD patients are recommended as further therapy after thrombolysis.

Adult↗
PubMed1988

Magnetic urokinase: targeting of urokinase to fibrin clot.

A plasminogen activator of human origin, urokinase, was endowed with magnetic property. The magnetic urokinase was composed of magnetite, polyethylene glycol derivative and urokinase, and dispersed in saline. Its particle size of magnetite was approximately 30-60 nm. It was selectively delivered to fibrin clot by magnetic force in continuously circulating plasma and exerted fibrinolytic activity without degrading fibrinogen.

Blood Coagulation Tests↗