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Biomedical subjects

H Shimura

Publications and source records attributed to H Shimura.

At least 163 records · Page 9Linked to original sources
PubMed1984

Decline in infectivity of simian virus 40 by sodium deoxycholate and its restoration with the extract of monkey kidney cells.

Plaque-forming activity and T-antigen-synthesizing activity in the crude preparation of simian virus 40 (SV40) decreased to 1/20-27 after treatment with 0.5% sodium deoxycholate (DOC) for 30 min at 37 degrees C. A full restoration of the activity occurred after incubation of DOC-treated virions with the extract of monkey CV-1 cells, host cells for productive infection with SV40. Analysis by sedimentation through 15% sucrose to CsCl cushion (rho = 1.327 g/cm3) revealed that virions in the [35S]methionine-labeled crude virus preparation sedimented to the interface between CsCl and sucrose, and that treatment with DOC resulted in the loss of infectivity and the appearance of virions sedimentable into CsCl cushion. The [35S]methionine-labeled purified virions (prepared after treatment with DOC and sedimentable into CsCl cushion) sedimented to the CsCl-sucrose interface after incubation with the cell extract, with restoration of infectivity. The infectivity-restoring activity of the cell extract was sensitive to ethyl ether, partially sensitive to heating at 75 degrees-97 degrees for 30 min, but resistant to treatment with DNase (50 micrograms/ml), RNase (40 micrograms/ml), or trypsin (0.05%) for 30 min at 37 degrees. These results suggest that lipid-related cellular components bind stably to virions of SV40 and facilitate an efficient infection.

Animals↗
PubMed1984

Abortive transformation of rat 3Y1 cells by simian virus 40: viral function overcoming inhibition of cellular proliferation under various conditions of culture.

Resting cultures of nonpermissive rat 3Y1 cells were infected with simian and T antigen expression and entry into S phase were examined under various conditions of culture. In the complete absence of serum from the medium or at an extremely high cell density, the cells delayed T antigen expression and entry into S phase, leaving the interval between the two events constant. Results using the viral mutants deleted in the coding region for the small t antigen ruled out the role of this antigen in induction of S phase. From these and other results presented, we conclude that the large T antigen induces S phase with the same efficiency under different conditions of cultures. We also present the evidence that the large T antigen function is required and is sufficient for entry into S phase in the second as well as in the first generation.

Animals↗
PubMed1984

Directional preponderance of optokinetic nystagmus. Study of 30 cases of unilateral cerebral lesions.

Analysis of the optokinetic nystagmus has been one of the most important means to examine the function of the vestibulo-oculomotor system. Especially in Japan, it has been used as a mean to analyze the function of the brain stem. We investigated directional preponderance of the optokinetic nystagmus in supratentorial lesions especially unilateral lesions, in the cerebral hemisphere which had been nearly neglected as an object for investigation of the vestibular system. We examined 30 cases of unilateral lesion in the cerebral hemisphere. In all cases CT-scan confirmed that these lesions have no mass effect which might affect the function of the surrounding brain. It was also confirmed that these cases had no spontaneous nystagmus. These cases consisted of 11 cerebral infarctions, 9 cerebral thrombosis, 6 cerebral hemorrhages and 4 cerebral contusions. In the result, 27 cases showed directional preponderance of the optokinetic nystagmus to the ipsilateral side, while there was none to the contralateral side. Three cases showed no directional preponderance. Some cases showed marked inhibition of optokinetic nystagmus of the contralateral side. These markedly inhibited cases are very similar to cases of pontine lesion which usually manifest marked inhibition of the optokinetic nystagmus to the ipsilateral side.

Aged↗
PubMed1983

Liquid crystal formation in ursodeoxycholate-rich human gallbladder bile.

We studied liquid crystal formation in bile samples obtained from the patients with radiolucent gallstones who had been administered either ursodeoxycholic acid (UDCA) at a dose of 600 mg/day or chenodeoxycholic acid (CDCA) at 400 mg/day for one week preoperatively. The UDCA/total bile acids ratio was found to range from 50 to 60% and the CDCA/total bile acids ratio ranged from 70 to 80%. Cholesterol molar percent was 5 in UDCA-rich bile and 6 in CDCA-rich bile. Phospholipid molar percentage was about the same in both groups. Liquid crystal formation was confirmed only in the UDCA-rich bile samples but not in the CDCA-rich bile samples. This result suggests that cholesterol in the UDCA-rich bile samples is not solubilized by the bile salt and phospholipid mixed micelles but also consumed to form liquid crystals.

Bile↗
PubMed1983

Gingival salivary gland choristoma: an extremely rare phenomenon.

An unusual case of a gingival salivary gland choristoma in a 9-year-old girl is presented. Clinically, the lesion appeared as a tumorlike mass of the maxillary incisor region. Histologic examination of the lesion revealed the presence of pure mucous glandular elements within the connective tissue. The possible mechanisms of its development in this unusual location and the nature of this lesion are discussed.

Child↗
PubMed1983

The developmental process from micelle to liquid crystal in the ursodeoxycholate, phosphatidylcholine and cholesterol solution.

The developmental process from micelle to liquid crystal via the bilayer membrane is described based on electron microscopic observations using the freeze fracture method in solutions containing ursodeoxycholate, phosphatidylcholine and cholesterol. Comparisons of sodium tauroursodeoxycholate and sodium taurochenodeoxycholate solutions were performed and this developmental process was confirmed only in the sodium tauroursodeoxycholate, phosphatidylcholine and cholesterol solution under physiological conditions.

Chemical Phenomena↗
PubMed1983

[Study on the correlation between tissue uptake of anticancer agents and prognosis -- with special reference to Tegafur].

Advanced gastric cancer cases (42 cases) undergone gastrectomy were studied on the correlation between tissue uptakes and prognosis. The patients were administrated Tegafur preoperatively and tissue samples were obtained intraoperatively, 5-FU levels in tumor and lymph node were measured by GCMF. The patients, being measured 5-FU uptake by tissue and received Tegafur over 60 g as postoperative adjuvant chemotherapy, were divided into two groups; namely, one with 5-FU up take by tumor tissue and lymph node was higher than 0.05 mcg/g and the other with lower than 0.05 mcg/g. Both groups showed no significant difference in background factors. Each survival rate was calculated by Kaplan-Meier method and examined by generalized Wilcoxon method. As the result, there was no significant correlation in the 5-FU uptake by tumor and prognosis, but prolongation of survival rate in the group of 5-FU uptake by lymph node over 0.05 mcg/g was suggested.

Adult↗
PubMed1983

[A new direct solubilizer for bilirubinate calcium stones].

Hepatobiliary surgeons must have faced difficulty in treating patients with intrahepatic gallstones. In spite of considerable progress in operative methods or mechanical techniques, it is very difficult to remove intrahepatic gallstones completely. Under such circumstances, the development of a solubilizer that can dissolve intrahepatic bilirubinate calcium stones by means of injecting it through a postoperative catheter or PTCD catheter has been awaited. Up to now, a chelating agent, so-called hexametaphosphate (HMP) has been used for removing the calcium from calcium bilirubinate. But this chelating agent, in itself, cannot dissolve the bilirubin. The authors found a direct solubilizer for bilirubin, dimethyl sulfoxide (DMSO) which is a well known bi-polar non protonic solvent and used as an accelerator for bilirubin determination. After the purification of DMSO to 99.98%, toxicity was examined by oral administration, intravenous administration and infusion into biliary tract. But no remarkable toxicity or side effects were detected on biochemical and pathological examinations. Clinical application of 90% DMSO together with 5% HMP was performed and a satisfactory effect was obtained as a direct solubilizer for bilirubinate calcium stones.

Aged↗
PubMed1981

An ultrastructural and immunohistochemical study on mandibular lesion of Letterer-Siwe disease.

A mandibular lesion from an infant with Letterer-Siwe disease was studied by electron microscopy and immunohistochemistry. Ultrastructurally, two types of cells were identified; clear and dark cells. Clear cells had indented nuclei and langerhans cell granules, while dark cells were characterized by the occasional presence of a large number of lysosomes. Lysozyme was usually not detectable in proliferating cells with indented nuclei, but it was strongly positive in cells without indented nuclei. The latter also usually contained IgG, although the occurrence of cytoplasmic IgM, A, D and E seemed to be negative in both types of cells. Thus clear cells showed a close resemblance to Langerhans cells and dark cells had features of ordinary histiocytes. Although the intimate relationship between these two types of cells remains obscure, our findings suggest that Letterer-Siwe disease may be a reactive or tumorous condition of a cellular subpopulation of Langerhans cells with a proliferation of differentiated histiocytes.

Antigen-Antibody Reactions↗
PubMed1981

Antiserum to SV40 T antigens from a rabbit inoculated with autochthonous cells transformed in vitro by SV40.

A morphologically transformed cell line was established after infection with SV40 of the primary culture derived from a kidney removed surgically from a rabbit. The transformed cells were free of detectable infectious SV40 particles but produced them upon fusion with permissive monkey cells, and produced SV40-specific large and small T antigens. Repeated subcutaneous inoculations of the transformed cells into the animal from which the parental kidney cells had been derived failed to result in tumor formation but raised a substantial level of antibodies to the SV40-specific large and small T antigens as well as to the 58,000 dalton molecular weight cellular protein (middle T antigen).

Animals↗
PubMed1978

In vitro studies on mechanism for concentrating function of gallbladder.

The mechanism for concentrating function of gallbladder was studied in vitro, turning and attention to changes in the gallbladder bile composition, especially a marked increase of Na+ and a marked decrease of Cl- in the concentrating process of hepatic bile to gallbladder one. The following results were obtained by the present investigations: 1) bile acids present in bile regulate the rate of Na+ and Cl- transport: 2) the epithelial membrane of the gallbladder can be regarded as being a simple semi-permeable membrane.

Animals↗
PubMed1978

A new approach to absorptive function of gallbladder.

To investigate the mechanism of concentration of bile, the normal canine gallbladders were cannulated through the cystic duct into the gallbladder neck with polyethylene tube, and hypotonic, isotonic and hypertonic salines as well as hepatic and gallbladder biles were placed in the gallbladder. Low molecular electrolytes such as Na+ and Cl- were transported across the epithelial membrane against water flux. The hepatic bile was decreased markedly in volume and each level of electrolytes including bile acids approached that in the gallbladder bile. The different results were obtained by concentration of the hepatic bile in the gallbladder with chemically induced cholecystitis.

Absorption↗
PubMed1978

Clinicopathological study on 100 early gastric cancer cases.

Clinicopathological study was given to 100 early gastric cancer cases. The cases included 50 intramucosal lesions (m-group) and 62 submucosal lesions (sm-group), and the share is 17% of whole cases treated surgically. The sex ratio is about 2:1 (male : female). According to the classification by location, the occurrence rate of lesion on anterior wall is 18.8%. This fact suggests the impotance of roentgenscopy by compression technique and double contrast in a prone position focussed on anterior wall. In addition, endoscopy is essential in order to detect minute cancers. The rates of metastasis of early gastric cancers is 2.4% of m-group and 16.1% of sm-group. No metastasis occurs in protruded or elevated type as far as cancer cells remain within the mucosa. Once cancer cells infiltrate into the submucosa, metastasis is observed in 36%. In the present cases, 9 (9%) out of 100 cases of early gastric cancers are the multiple cases. In order to avoid oversight of cancer foci, the portion of stomach to be remained after surgery should be throughly examined prior to operation and again under direct vision after gastric incision.

Adenocarcinoma↗