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Biomedical subjects

Y Hata

Publications and source records attributed to Y Hata.

At least 433 records · Page 24Linked to original sources
PubMed1986

Crystal structures of modified myoglobins. I. Heme orientation and structural changes around heme in myoglobins reconstituted with isopemptoheme, pemptoheme, 2-ethyldeuteroheme, and 4-ethyldeuteroheme.

The crystal structures of sperm whale metmyoglobins reconstituted with four modified hemes, isopemptoheme, pemptoheme, 2-ethyldeuteroheme, and 4-ethyldeuteroheme, have been determined and refined at 2.2 A resolution to R = 0.217, 0.218, 0.213, and 0.222, respectively. All the crystals of these myoglobins are isomorphous with that of native metmyoglobin. The structural changes of the modified myoglobin from the native myoglobin were examined on difference Fourier maps; the orientation of 4-ethyldeuteroheme in the heme pocket is such that the heme is rotated by 180 degrees about an axis through the alpha-gamma-meso carbons, whereas the orientations of the other three hemes are the same as that of the protoheme in the native myoglobin. The changes of the structures around the heme become greater in the order of isopemptoheme, 2-ethyldeuteroheme less than pemptoheme less than 4-ethyldeuteroheme. The magnitudes of the changes seem to be related to the oxygen affinities of these four reconstituted myoglobins.

Animals↗
PubMed1986

Application of Friedewald's LDL-cholesterol estimation formula to serum lipids in the Japanese population.

When direct measurement of serum low density lipoprotein cholesterol (LDL-c) is not available, it can be estimated from total cholesterol (TC), triglycerides (TG) and high density lipoprotein cholesterol (HDL-c) by using the formula proposed by Friedewald: LDL-c = TC-[HDL-c + TG/k], k = 5 This formula assumes the triglyceride/cholesterol ratio in VLDL to be 5:1. However, it is changeable with serum triglyceride levels, and averaged as 4 among Japanese with triglycerides less than 400 mg/dl. The formula provides a better fit for Japanese people, when k = 4, rather than original k = 5. In addition, a better estimation is gained, if k is rotated according to the triglyceride levels of individual subjects; i.e. 3 for those with triglycerides less than 150 mg/dl, 4 for those with triglycerides from 150 to 299 mg/dl, 5 for those with triglycerides from 300 to 400 mg/dl. The percent error of estimation is less than 5% when k = 4, and about 1% when variable k is employed for populations of about 1,000 subjects in number.

Adult↗
PubMed1986

[The statistical evaluation of the female breast cancer detected by mass screening in Hokkaido].

In Hokkaido, 113, 612 women were subjected to mass screening of breast cancer from 1973 to 1983. Out of them, 74, 285 (56.3%) were examined once and the remainder twice or more: 4,798 (4.2%) were advised to receive further precise examinations and 99.8% of them underwent the second examination. Breast cancer was detected in 377, in which 291 (77.2%) were detected by the first examination and 33 (3.8%) were so-called "interval cancer" with the mean interval of 19.3 months. The detection rate was 0.3%. Histologically non-invasive cancer was seen in 26 (6.9% of 377). Despite a recent significant increase in detection rate of the earlier stage of breast cancer, the present study showed no evidence of a decrease in advanced cancer. The prognosis of the patients who had curable operation revealed 86.9% in 5 year survival rate and 40% in 10 year survival rate.

Breast Neoplasms↗
PubMed1986

[Surgical treatment of chronic constipation with megarectum in children].

In this paper, a new operative procedure for patients with chronic constipation with megarectum and its results are presented. Nine cases of idiopathic chronic constipation and one case of short aganglionosis showing megarectum underwent this operation. An incision was placed on the dentate line at 6 o'clock and the internal sphincter muscle was identified. The incision was extended to this muscle. The blunt division between the internal and external sphincter muscles was orally advanced 5 cm from the dentate line. The all layers of anus and lower part of rectum in length of 5 cm were clamped by 2 forceps in width of 1 cm. The mucosal and muscular layers were bilaterally cut in the outer side of the forceps. The rectum on the top of the forceps was pulled through to the dentate line and was anastomosed there; i.e. the posterior part of the anus was replaced by the rectal wall. Bowel habits of operated patients were evaluated at 1 to 3 years after the operation. Complete cure was obtained in 7 cases (including 1 case with aganglionosis). Three cases improved but needed sometimes suppositories. This procedure, sphinctero-myectomy and-plasty may be an operation of choice for chronic constipation with megarectum.

Adolescent↗
PubMed1986

[New surgical technic in megarectum].

The sphinctero-myectomy as a surgical treatment of megarectum has been generally advocated, but its results are not always satisfactory. In this paper, a new surgical treatment will be presented. Ten cases with idiopathic chronic constipation presenting megarectum in barium enema underwent this operation. After anal dilatation, incision was made in width of 2 cm at 6 o'clock on the dentate line. The blunt split between internal and external sphincter muscles was advanced to 6 cm orally. The all layers of superior part of anus and lower part of rectum in length of 5 cm were clumped by two forceps in width of 1 cm. Then the all layers in outer side of forceps were cut bilaterally. The rectum on the top of the forceps was pulled through to the dentate line and was anastomosed there. The operative results were evaluated more than one year after the operation. Complete cure was noticed in 7 cases and marked improvement in 3 cases. Our procedure, named as sphinctero-myectomy and plasty can be operation of choice for chronic constipation with megarectum.

Adolescent↗
PubMed1985

Revision of porto-enterostomy in congenital biliary atresia.

For the patients with insufficient bile flow following porto-enterostomy for congenital biliary atresia, removal or resection of granulation or scar tissue at the porta hepatis has been performed. Of 11 reoperations, constant bile excretion was obtained in four. Sufficient resection of scar tissue at the porta hepatis was most important for revision of porto-enterostomy. For resection of scar tissue, a special scissors devised by us was used.

Bile↗
PubMed1985

Preliminary X-ray studies on Serratia protease.

Preliminary X-ray studies on Serratia protease have been carried out using crystallographic and small angle scattering techniques. The enzyme has been crystallized in three different crystalline forms by microdialysis and vapor diffusion methods using 50 mM phosphate buffer, pH 6.0, at 24 degrees C. They have orthorhombic space groups: C222(1) for one form and P2(1)2(1)2(1) for the other two forms. A small angle X-ray scattering study showed that the radius of gyration and the maximal dimension of the molecule in aqueous solution are 26.6 A and 94.5 A, respectively. The molecular weight of the enzyme was determined to be 45,000-48,000 by various physical methods.

Crystallography↗
PubMed1985

Enzymatic responses and adaptations to swimming training and hypobaric hypoxia in postnatal rats.

Twenty four male Sprague-Dawley rats, 35 days old, were randomly assigned to one of four groups: 2 resting control groups and 2 swimming groups. The sea level-control and the sea level-swimming groups were housed 5 weeks at 1,011 hPa (760 mmHg) while the hypoxic control and swimming groups were housed for 1 week at 678 hPa, followed by 4 weeks at 611 hPa. The swimming rats were subjected to a swimming program of 30 min, 6 days/week for 5 weeks. Both hypoxia groups developed significantly higher Hb and Hct levels than the sea level groups. The glycogen content in the extensor digitorum longus (EDL) and the deep portion of the vastus lateralis (DVL) muscles of the sea level-swimming group were significantly greater as compared to the hypoxia swimming group. The succinate dehydrogenase (SDH) activity in the sea level-control group was significantly lower in the EDL muscle than in the 3 other groups, and in the DVL muscle lower than that of the sea level-swimming group. Histochemically, hypoxia and swimming training induced significant increases in the fast-twitch-oxidative-glycolytic (FOG) fibers (6-11%) in soleus muscle, and decreases in the slow-twitch-oxidative (SO) fibers. The EDL muscles had significantly higher percentages of FOG fibers in the hypoxia and swimming groups than in the sea level-control group. On the basis of the present study it seems probable that hypoxia is a triggering factor for the conversions of muscle fiber types and the increase in oxidative capacity.

Acclimatization↗