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Biomedical subjects

K Sakurai

Publications and source records attributed to K Sakurai.

At least 289 records · Page 16Linked to original sources

Separation of heparin on Sepharose CL-4B in the presence of high concentrations of ammonium sulphate.

Heparin was fractionated by chromatography on Sepharose CL-4B/3.8-2.0 M ammonium sulphate in 0.01 M hydrochloric acid at 4 degrees C based on a principle different from that of gel filtration--possibly due to multiple interaction mechanisms including those based on hydrophobic bonds. The results of the fractionation were very similar to those of chromatography on Phenyl-Sepharose CL-4B/3.8-2.0 M ammonium sulphate in 0.01 M hydrochloric acid at room temperature. That is, the separation was related to the molecular size distribution, N-acetyl content and anticoagulant activities. As the result of studies on a set of Sepharose 4B gels with different degrees of cross-linking, it has been shown that the introduction of the cross-linked structure, -O-CH2-CH(OH)-CH2-O-, into the gel matrix enhances the interaction between the Sepharose CL-4B gel and heparin, indicating that heparin retention by the highly cross-linked Sepharose 4B gel surpasses that by Phenyl-Sepharose CL-4B.

Ammonium Sulfate↗

Somatostatin-like immunoreactivity in rat thyroid. Age-associated S-cell hyperplasia.

Somatostatin-like immunoreactive cells of the rat thyroid gland at various ages were investigated immunohistochemically. The number of cells per lobe in 5 micron sections increased with age. Immunopositive cells were evident as small clusters in the older age group (8 to 24 months old) but not clustered in the younger age group (3 to 5 months old). This type of proliferation was termed S-cell hyperplasia in a manner similar to C-cell hyperplasia observed in the aged rat thyroid.

Aging↗

Diarrhea in neonatal piglets caused by K99+ST+ enterotoxigenic Escherichia coli.

Enterotoxigenic Escherichia coli strains were isolated from the feces of 34.4% of 64 diarrheaic neonatal piglets on seven farms. Of a total of 518 isolates, 86 (16.6%) were enterotoxigenic and grouped into four phenotypes: K99+ST+ (K99 pilus antigen and heat-stable enterotoxin producing, 36 strains), ST+ (37 strains), K88+LT+ (K88 pilus antigen and heat-labile enterotoxin producing, 11 strains), and K88+ST+ (2 strains). K99+ST+ and ST+ isolates showed multiple drug resistance and most of those (58.3% and 56.8%, respectively) belonged to O serogroup 101. A K99+ST+ isolate proved to be capable of inducing diarrhea and death in hysterectomy-produced colostrum-deprived piglets when orally inoculated.

Animals↗

Protection of hypoxic myocardium by intracoronary administration of verapamil in open-chest dogs.

Hypoxic perfusion of the regional myocardium was performed in 34 open-chest dogs. In eight dogs in which the myocardium was perfused with original hypoxic Krebs-Henseleit (K-H) solution for 5 min (group I) there was a marked decrease in adenosine triphosphate content (2.03 +/- 0.44 mumol/g) and an increase in lactate content (8.65 +/- 2.26 mumol/g). In myocardium of nine dogs (group II) perfused with verapamil-containing (1.3 mg/dl) K-H solution and in that of nine dogs (group III) receiving Ca2+-free solution, the degrees of reduction in adenosine triphosphate (2.99 +/- 0.73 and 3.25 +/- 0.48 mumol/g, respectively) and of lactate accumulation (5.16 +/- 0.59 and 4.79 +/- 1.02 mumol/g, respectively) at 5 min were significantly less than in group I. Absence of statistically significant differences in hemodynamic parameters among these three groups indicates that the metabolic preservation in group II probably resulted from a direct effect of verapamil on the regional myocardium related to Ca2+ metabolism. However, metabolic data in four dogs of group I and four dogs of group III killed at 40 sec of perfusion, in conjunction with results of the analysis of regional contraction, revealed that the time courses of segmental shortening in the three groups did not account for the metabolic differences among them.

Adenosine Diphosphate↗

Different effects of acute ischemia and anoxia on the canine myocardium.

We investigated differences between ischemic and anoxic myocardium with respect to early mechanical and metabolic changes. Ischemia and anoxia were induced in the area perfused by the distal left anterior descending artery in 32 mongrel dogs. Since both the ischemia and the anoxia in this preparation resulted in very little change in global cardiac hemodynamics, indirect mechanical and metabolic effects on the involved myocardium were minimal. However, regional anoxia caused a later development of a myocardial systolic bulge than did regional ischemia (44.8 +/- 13.6 vs 26.8 +/- 9.9 sec). Myocardial ATP content was reduced to the same level 5 min after the onset of ischemia and anoxia. Anoxia with high K+ did not result in an earlier myocardial systolic bulge time, but myocardial ATP was maintained at a higher level than during ischemia. Anoxia with low pH also did not affect the time for development of a myocardial systolic bulge. We concluded that neither acidosis nor hyperpotassemia are more causally related to the earlier development of a myocardial systolic bulge during regional ischemia than during regional anoxia. Also the absolute value of myocardial ATP content is unlikely to be causally related to the determination of myocardial contraction, as reflected by the development of a myocardial systolic bulge.

Acute Disease↗

Immunogenicity and safety of an attenuated Bordetella bronchiseptica vaccine in pigs.

The immunogenicity and safety of an attenuated Bordetella bronchiseptica vaccine for swine atrophic rhinitis (AR) was evaluated in 22 hysterectomy-produced, colostrum-deprived pigs and 18 conventional pigs. None of 8 pigs inoculated at 7 days of age intranasally with greater than or equal to 3 X 10(5) colony-forming units (CFU) of vaccinal strain/pig and 2 of 5 pigs inoculated at 7 days of age intranasally with 3 X 10(4) CFU of the vaccinal strain/pig developed AR after intranasal challenge exposure with a virulent strain at postinoculation week (PIW) 3. The remaining 3 vaccinated pigs and 4 nonvaccinated pigs developed AR. Thirteen pigs were inoculated intranasally with 3 X 10(6) to 3 X 10(9) CFU of the vaccinal strain at 7 days of age. At PIW 12, the pigs were killed and necropsied. None of the pigs had clinical signs of AR and/or pneumonia. Virulence was studied by transmission of vaccinal strain through 3 serial growing passages on the nasal mucosa of a litter of hysterectomy-produced colostrum-deprived pigs. Inoculum (nasal swab samples from 2 pigs 4 days after inoculation with 10(8) CFU of vaccinal strain at 5 days of age) was inoculated into the nasal cavity of 2 nonvaccinated pigs. This procedure was repeated 3 times. After the 1st passage, the vaccinal strain was recovered on postinoculation day 4, but after postinoculation day 4, the vaccinal strain was not recovered until the end of the 3rd passage. Turbinate atrophy or pneumonia was not recognized in these inoculated pigs. The vaccinal strain provided immunogenicity without ill effects.

Animals↗

[Radiation-induced breast cancer].

A 24-year-old woman with radiation-induced breast cancer is reported. At 9 years of age she had received 4,000 R irradiation to her chest to treat an eosinophilic granuloma of the rib. Fifteen years later, she suffered from breast cancer. We suggest that the irradiation-induced the breast cancer.

Adult↗