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Biomedical subjects

K Hanada

Publications and source records attributed to K Hanada.

At least 307 records · Page 17Linked to original sources
PubMed1988

An ultrastructural study of changes in the tendinous attachment of the deep layer of masseter muscle to the rat mandible during bite raising.

To elucidate the ultrastructural changes in the attachment of masticatory muscles during changes in the functions of masticatory muscles, rats ranging in age from 50 to 80 d, were used. 2 d after bite-raising, the fibrocartilage cells in the tendinous attachment of the deep layer of masseter muscle were characterized by ill-developed cell organelles. Undifferentiated cells around blood vessels degenerated. 4 d after bite raising, however, fibrocartilage cells exhibited well-developed cell organelles, cell division and intercellular contacts. After 10 d of bite raising, the morphologic features of the fibrocartilage cells were the same as those observed in the control. These results suggest that the mechanical stress created by the change in muscle function during bite raising caused the degeneration of the fibrocartilage cell. From 4 d after bite raising, cell proliferation and active formation of new extracellular matrix occurred in response to environmental changes. 10 d after bite raising, the remodeling of collagen fiber and the formation of bone tissue had returned to normal by the adaptation of muscle function.

Animals↗
PubMed1987

Construction and properties of bifunctionally active membrane-bound fusion proteins. Escherichia coli proline carrier linked with beta-galactosidase.

For construction of bifunctionally active membrane-bound fusion proteins, we designed plasmids encoding fusion proteins in which the carboxyl terminus of Escherichia coli proline carrier was joined to the amino terminus of E. coli beta-galactosidase directly or with a collagen linker inserted between the two. The expressions of these fusion proteins complemented deficiencies in both proline transport and beta-galactosidase activity in E. coli cells. The fusion proteins were stable and mostly localized in the cytoplasmic membrane. The proline transport activities of the fusion proteins were kinetically similar to that of the wild type proline carrier. The beta-galactosidase moiety of the collagen-linked fusion protein was liberated from membrane vesicles by collagenase treatment. The Km value of released beta-galactosidase for o-nitrophenyl beta-D-galactopyranoside hydrolysis was similar to that of membrane-bound beta-galactosidase in the fusion protein. These results indicated that the fusion proteins are bifunctionally active and exhibit normal proline transport and beta-galactosidase activities. The crypticity of the beta-galactosidase activity associated with the fusion proteins indicated that the carboxyl terminus of the proline carrier was located on the cytoplasmic side of the membrane.

Amino Acid Transport Systems, Neutral↗
PubMed1987

Characterization of E. coli-derived recombinant human interferon-beta as compared with fibroblast human interferon-beta.

Homogeneous E. coli-derived recombinant human interferon-beta (E. coli-rHuIFN-beta) was characterized in order to elucidate its physicochemical properties, as compared with those of fibroblast human interferon-beta (fibroblast HuIFN-beta). Purified E. coli-rHuIFN-beta and fibroblast HuIFN-beta exhibited a single band of Mr 19,000 and 23,000, respectively, on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The primary structure of E. coli-rHuIFN-beta was identical to the prediction from the cDNA sequence. Furthermore, both the circular dichroism (CD) spectra and the 1H nuclear magnetic resonance (NMR) spectra of E. coli-rHuIFN-beta and fibroblast HuIFN-beta at pH 6.8 were closely similar to each other. On the other hand, on reverse-phase high-performance liquid chromatography (HPLC) using a C18 column, the retention time of E. coli-rHuIFN-beta was longer than that of fibroblast HuIFN-beta. Moreover, although the isoelectric point of E. coli-rHuIFN-beta was pH 8.9, purified fibroblast HuIFN-beta exhibited multiple isoelectric points, probably due to heterogeneity of the carbohydrate moiety. These results indicate that the E. coli-rHuIFN-beta polypeptide folds similarly to fibroblast HuIFN-beta, and the carbohydrate moiety of natural HuIFN-beta has little influence on higher-order structure but does influence the hydrophobic and the electrostatic properties of the molecule.

Amino Acid Sequence↗
PubMed1987

Prolongation of life span of dystrophic hamster by cysteine proteinase inhibitor, loxistation (EST).

We studied the effect of loxistation (EST), an orally applicable cysteine proteinase inhibitor, on dystrophic hamsters, UM-X7.1.E-64-c, an active form of EST, was continuously found in plasma when the feed containing EST was given ad libitum. The drug concentration in plasma of dystrophic hamsters receiving EST feed showed distinct dose dependency. A diet containing EST from weaning to death significantly prolonged the survival period of the dystrophic hamsters.

Animals↗
PubMed1987

Radiologic findings in xanthogranulomatous cholecystitis.

Xanthogranulomatous cholecystitis is rare, and information on its radiologic diagnosis is limited. Radiologic findings of seven patients with histologically proven xanthogranulomatous cholecystitis were reviewed retrospectively. Sonography showed a calculus or calculi of the gallbladder with moderate thickening of the wall in all. IV cholangiography was performed in six cases. Findings were nonspecific. Four had nonopacified gallbladder, and one had stenosis of the proximal part of the common bile duct. Marked thickening of the gallbladder wall was seen in six of seven cases on CT. In one case the thickened wall was lobulated and irregular. The border between the gallbladder and the adjacent liver was unclear in two and relatively clear in five. Four patients underwent angiography to evaluate the possibility of tumor. Two of them had irregularity and stenosis of the cystic artery highly suggestive of carcinoma. The other two showed only dilatation of the cystic artery. On the basis of all radiologic studies, carcinoma was diagnosed preoperatively in two of the seven cases. Radiologically, xanthogranulomatous cholecystitis may best be regarded as a tumor-like condition and should be included in the differential diagnosis of gallbladder cancer.

Aged↗
PubMed1987

Immune responses in newly developed short-lived SAM mice. Selectively impaired T-helper cell activity in in vitro antibody response.

New short-lived strains of mice (SAM-P), which have been developed by Takeda et al. (1981), shows a defective antibody response to T dependent (TD) antigen in vitro, as demonstrated in the accompanying paper (see page 419). In the present study, we investigated the cellular site of the defect, using a cell culture system. In this paper, it is demonstrated that T-helper (Th) cell activity for the antibody response to TD antigen is impaired, while other cellular immune responses, e.g. mixed leucocyte reaction, cytotoxic T-lymphocyte response, and delayed-type hypersensitivity reaction, are normal. These results suggest that the defect in T-helper subset is limited in helper function for the antibody response, and that the helper function for the cell-mediated immune responses is intact. These two functions of the T-helper subset are apparently regulated in a different manner. The SAM-P strains of mice may thus serve as an appropriate model for studying functional heterogeneity in T-helper/inducer cell subsets.

Aging↗
PubMed1987

A molecular-pathologic approach to murine senile amyloidosis. Serum precursor-apolipoprotein A-II variant (Pro5----Gln) presents only in the senile amyloidosis-prone SAM-P/1 and SAM-P/2 mice.

Murine apolipoprotein (apo) A-II is a serum precursor of murine senile amyloid protein. We determined the primary structures of apo A-II in accelerated senescence-prone mice (SAM-P) characterized by a high frequency of age-associated systemic amyloidosis and accelerated senescence-resistance mice (SAM-R) in which senile amyloidosis occurred with a low incidence. Apo-A-II variant (Pro5----Gln) was found to be present only in the serum of SAM-P and not in that of SAM-R or other random bred slc:ICR mice. The apo A-II variant in the serum of SAM-P is identical to the murine senile amyloid fibril protein (ASSAM) derived from amyloid-deposited tissues of SAM-P. These findings proved that apo A-II deposits in tissues without degradation and this mutation (Pro5----Gln) probably have significant effects on the structure and function of apo A-II and would play a critical role in murine senile amyloidogenesis.

Aging↗
PubMed1986

Periodic exposure to mother is potent zeitgeber of rat pups' rhythm.

To study the possibility and potency of periodic maternal deprivation (PMD) in entraining the circadian rhythm of rat pups, access to the natural mother of which pups were optically enucleated on the day of birth (day 1) was restricted to either light phase (L-group) or dark phase (D-group) for various durations beginning on various days during the nursing period. Drinking rhythm of both groups was determined once per one or two weeks between the 4th and 8th postnatal week. The corticosterone rhythm was determined to confirm the results obtained by the measurement of water intake. Both rhythms were clearly observed by 5 weeks of age, and a reversed phase relationship was observed even when PMD was performed for a short period during days 1-4 or days 15-21. On the other hand, no phase angle difference was observed between L- and D-groups, when pups were periodically exposed to their original mother either during days 1-2 or days 18-21. These facts indicate that periodic exposure to mother can set the phase of the blinded pups' rhythm and that the period required for entrainment of the rhythm is as short as 4 or 7 days in the early or late times during the nursing period respectively, showing the high potency of PMD in entraining the circadian rhythm of blinded pups.

Aging↗
PubMed1986

Three-dimensional prediction of mandibular movement in the treatment of prognathism.

The three-dimensional movements of the mandible that might occur during surgical correction of mandibular prognathism were analyzed preoperatively in 40 patients. Direct measurements were made on the dental models used to predict postoperative occlusion, and the results were transferred to the cephalometric tracings using three-dimensional coordinate transformation. Menton, gonion, and two bony points on the posterior borders of the ascending rami were chosen on the frontal and lateral cephalograms for prediction of the antero-posterior, vertical, and lateral movements. In most cases a reasonable amount of movement without much lateral shift at the posterior border of the mandible was predicted to occur when the postoperative position of the mandible was established to provide a stable occlusion. However, there were five cases in which predicted lateral movement at one of the posterior borders exceeded 5 mm, and, in four of them, protrusion of the mandible was not accompanied by lateral deviation. It was concluded that careful preoperative planning and postoperative treatment are necessary in these cases because a large amount of lateral movement at the site of operation might lead to postoperative relapse following ramus osteotomy.

Cephalometry↗
PubMed1986

Satisfaction of patients following surgical-orthodontic correction of skeletal Class III malocclusions.

To assess whether patients were satisfied with the results of treatment, questionnaires were sent to 65 patients who had undergone either the extraoral curved oblique osteotomy or the sagittal split osteotomy for correction of skeletal Class III malocclusions. Seventy-eight per cent of the patients answered that they were satisfied with the results in regard to their chief problems and 75% had improved masticatory function. A favorable change in appearance was recognized by 33 patients, whereas 30 patients noticed no major changes. Factors affecting satisfaction with the results are discussed.

Adolescent↗