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Biomedical subjects

H Mitani

Publications and source records attributed to H Mitani.

At least 145 records · Page 8Linked to original sources
PubMed1993

Inhibitory effect of 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB-8) on germination of Bacillus cereus T spores.

Effect of 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB-8), a calcium antagonist, on germination of Bacillus cereus T spores induced by L-alanine and inosine was investigated. TMB-8 had no effect on the germination of heat-activated spores, whereas it inhibited that of nonactivated spores. The TMB-8 inhibitory effect was antagonized competitively by inosine, but not by L-alanine. Addition of Ca2+ reversed the inhibitory effect of TMB-8 in a dose-related fashion. Based on the results, a role of inosine and a site(s) for inhibitory action of TMB-8 in the process leading to the germination of nonactivated spores were discussed.

Alanine↗
PubMed1993

A novel renal cell carcinoma susceptibility gene maps on chromosome 10 in the Eker rat.

Hereditary renal cell carcinoma (RC) in the rat, originally reported by Eker in 1954, is an example of Mendelian dominant predisposition to a specific cancer in an experimental animal. We previously reported that this predisposing inherited gene is a tumor suppressor gene fitting Knudson's "two-hit" model. This study was designed to map the RC susceptibility gene in the Eker rat using backcross animals. Our present data clearly show that the RC gene is genetically linked to the protamine-1 gene (Lod score = 11.65) and the interleukin-3 gene (Lod score = 4.13), both of which are located on the proximal part of rat chromosome 10. Rat chromosome 10 is currently believed to have no syntenic relationship to human chromosome 3p, the presumed site of the putative tumor suppressor gene for human RC and the locus of von Hippel Lindau disease (affected patients develop multiple RCs). Thus, the Eker rat might have a mutation of a novel tumor suppressor gene related to renal carcinogenesis.

Animals↗
PubMed1993

[Influence of urine pH and cations on antimicrobial activities of penems].

We compared the antimicrobial activities of penems in human urine with those in Mueller-Hinton broth in order to clarify the usefulness of penems for urinary tract infections. Furthermore, we also investigated the influence of urine components, such as pH, magnesium concentration and calcium concentration, on the antimicrobial activities of penems. Three penems, i.e., imipenem, panipenem and meropenem were employed. And two bacterial strains, i.e., Escherichia coli NIHJ JC-2 and Pseudomonas aeruginosa 18s, were tested. There was no significant difference in MBCs between human urine and Mueller-Hinton broth against E. coli. However, MBCs of penems in human urine was lower than those in Mueller-Hinton broth against P. aeruginosa. On the other hand, MBCs of penems against these two strains were low when urine pH was high or urine calcium concentration was low. No influence of urine magnesium concentration on MBCs of penems was seen. From these results, it was suggested that we should measure the antimicrobial activities of penems not only in Mueller-Hinton broth, but also in human urine, when we administer penems to patients with urinary tract infections. And we should foresee the clinical effects of penems against urinary tract infections paying attention to urine pH of the patients.

Cations, Divalent↗
PubMed1993

[Three cases with pelvic dead space infection after total cystectomy caused by methicillin-resistant Staphylococcus aureus (MRSA)--local injection of vancomycin].

We recently had three patients with pelvic dead space infection caused by methicillin-resistant Staphylococcus aureus (MRSA) after total cystectomy for urothelial cancer. All were male and aged from 67 to 74 years old. As for underlying diseases, two of them had bladder cancer and one of them had bladder cancer and right ureteral cancer. Total cystectomy and ileal conduit were performed for two patients with bladder cancer, and total cystectomy, nephroureterectomy and ureterocutaneoustomy were performed for a patient with bladder cancer and ureteral cancer. Pelvic dead space infections caused by MRSA appeared after 15-30 days postoperatively. All patients were cured after we locally administered 0.5 g of vancomycin twice a day for 10-11 days from the drains to the pelvic dead spaces. All patients had preoperative antitumor chemotherapy and the postoperative administrations of beta-lactams in common. From these results, we suggest that local administration of vancomycin is effective for the pelvic dead space infection caused by MRSA after total cystectomy.

Aged↗
PubMed1993

Response to transcatheter oily chemoembolization in hepatocellular carcinoma 3 cm or less: a study in 50 patients who underwent surgery.

The response of 50 patients who underwent hepatectomy for hepatocellular carcinoma measuring 3 cm or less (at the time of surgery) to transcatheter oily chemoembolization was evaluated. The response was assessed in 5 categories, A: complete necrosis (100%), B: necrosis of at least 95%, C: at least 80%, but less than 95%, D: at least 50% but less than 80%, and E: less than 50% of the tumor cells. Response A was observed in 19 patients (38%), B in 7 (14%), C in 9 (18%), D in 7 (14%), and E in 8 (16%). These results were classified with respect to the histological degree of tumor differentiation, the WHO histological classification, the microscopic patterns of tumor growth, and macroscopic classification. The response was evaluated in relation to the histological grade of tumor differentiation and the WHO histological classification in all categories of response except response A, and there was no significant difference between the categories. The response was obviously better with the expansive type than with the replacing type. Single nodular type lesions were more responsive than the single nodular type lesions with extranodular growth and the contiguous multinodular type. Pretreatment estimation of the microscopic patterns of tumor growth and macroscopic classification appears to be valuable in predicting prognosis.

Adult↗
PubMed1992

A highly repetitive interspersed sequence isolated from genomic DNA of the Medaka, Oryzias latipes, is conserved in three other related species within the genus Oryzias.

A highly repeated interspersed sequence (OLR1) was isolated from a genomic DNA library of the Medaka, Oryzias latipes. The OLR1 was about 160 base pairs (bp) in length. As judged from the results of colony hybridization experiments, OLR1 is one of the major repeated DNA sequences in the Medaka genome and is present in every 136 kb on average. Results of Southern and colony-hybridization analyses indicate that OLR1 is a small interspersed repetitive element (SINE). OLR1-related sequences were conserved in other three species (O. luzonensis, O. curvinotus, and O. mekongnensis) within the genus Oryzias as a repetitive sequence. These results lend support at the DNA level to the hypothesis that these four species form one group in the genus Oryzias, as has been suggested from an analysis of their karyotypes (Magtoon and Uwa, '85, Proc. Jpn. Acad., Ser. B, 61:157-160).

Animals↗
PubMed1992

The Dynamic Dento-palatography System: a new approach for evaluating speech.

The assessment of speech in patients with craniofacial anomalies is important to develop appropriate treatment strategies to optimize this aspect of oropharyngeal function. The Dynamic Dento-palatography System which uses multi-electrode array sensors to detect tongue position during articulation is described. Three levels of the speech chain, articulatory, auditory and acoustic, may be analysed in an integrated fashion using this instrument; preliminary results are described. These studies suggest that the quality of speech sounds such as 's' and 't' improve post-operatively.

Dental Arch↗
PubMed1992

Comparison of mandibular growth with other variables during puberty.

The purpose of this investigation was to compare growth characteristics of the mandible during puberty with growth characteristics of the hyoid bone, cervical vertebrae, hand bones and standing height. Data were compiled from serial lateral cephalometric roentgenograms, hand-wrist roentgenograms and body height records of 33 Japanese girls between 9 and 14 years old. Records were updated annually. The mandibular growth rate differed from the other growth rates. The timing of maximum growth velocity of the mandible varied more widely than the timing of maximum growth velocity of the other parameters measured, and the total amount of mandibular growth did not correlate to any other measurement. The timing and magnitude of circumpubertal growth acceleration of various components of the body vary within a certain range of difference. However, the amount and timing of mandibular growth seems to be more variable than the other areas studied.

Adolescent↗
PubMed1992

Enhancement of photorepair of ultraviolet-induced pyrimidine dimers by preillumination with fluorescent light in the goldfish cell line. The relationship between survival and yield of pyrimidine dimers.

The enhancement of photorepair of UV-induced pyrimidine dimers by preillumination with fluorescent light, previously reported with RBCF-1 cells derived from caudal fin of a goldfish, was studied in terms of clonogenic ability and yields of dimers. In the logarithmic growth phase, the ability of photorepair increased with the time after preillumination, reached a maximum at 8 h, and gradually declined. At 8 h, the dose decrement with the photorepair-treatment for 20 min at 7.5 J/m2 UV increased by preillumination for 1 h from 1.6 to 3.1 J/m2 in terms of restoration of survival and from 1.2 to 4.3 J/m2 in terms of the disappearance of dimers. Incubation of the preilluminated cells in the medium containing cycloheximide (0.5 microgram/mL) after preillumination until UV-irradiation diminished their enhancement of photorepair. In the density-inhibited state, the ability of photorepair was higher than in the log phase, and it was hardly enhanced by preillumination.

Animals↗
PubMed1992

[Influence of new quinolones on superoxide anion generation of polymorphonuclear leukocytes].

We investigated the influence of the new quinolones for the ability to kill on polymorphonuclear leukocytes (PMNs) in phosphate buffer solution (PBS) and in the urine in order to clarify the in vivo effects of the new quinolones. Four new quinolones, i.e., norfloxacin, enoxacin, ofloxacin and ciprofloxacin were employed. PMNs derived from peripheral blood in PBS and in hypotonic urine were stimulated with phorbol myristate acetate or opsonized zymosan, and superoxide anion generation of PMNs was measured by means of the chemiluminescence method. The superoxide anion generation of PMNs was significantly enhanced in the presence of 10 micrograms/ml of all new quinolones and significantly suppressed in the presence of 100 micrograms/ml of all new quinolones in PBS and in hypotonic urine. From these results, it was suggested that no influence of new quinolones on the ability to kill the PMNs might be seen in human blood, however, a great influence might be expected in the urine in the human urinary tract.

Ciprofloxacin↗
PubMed1992

A comparison of the immunohistochemical localization of type I and type II collagens in craniofacial cartilages of the rat.

The immunohistochemical localization of types I and II collagen was examined in the following 4 cartilaginous tissues of the rat craniofacial region: the nasal septal cartilage and the spheno-occipital synchondrosis (primary cartilages), and the mandibular condylar cartilage and the cartilage at the intermaxillary suture (secondary cartilages). In both primary cartilages, type II collagen was present in the extracellular matrix (ECM) of the whole cartilaginous area, but type I collagen was completely absent from the ECM. In the secondary cartilages, type I collagen was present throughout the cartilaginous cell layers, and type II collagen was restricted to the ECM of the mature and hypertrophic cell layers. These observations indicate differences in the ECM components between primary and secondary craniofacial cartilages, and that these differences may contribute to their modes of chondrogenesis.

Animals↗
PubMed1992

[Human body volume measurement by sulfur hexafluorde-dilution method and its application to human body composition assessment].

The absolutely accurate measurement of adiposity in a living organism is undoubtedly difficult. Although a number of methods have been developed, none has been proven to be both theoretically and empirically an unquestioned validating criterion method for the estimation of human body composition. In the present study, a new method was introduced that is rapid, safe, and relatively simple to administer and has the added advantage of not requiring a measurement of the underwater weight. The procedure involves the direct measurement of body volume by applying a sulfur hexafluoride (SH)-dilution method with the subject only standing in a 375-1 closed chamber (Shimazu BSF-100) that is filled with air and 0.26 liters of SH. Results indicate that body volume (r = 0.998) and body density (r = 0.819) measured by the SH method were highly correlated to those determined by underwater weighing. Reproducibility of body volume was found to be almost perfect (i.e., 0.995) with the regression coefficient of 1.03 and the intercept of -1.5. Variability (CV = 0.7%) in body volume of a 45-year-old reference man measured by SH method was very similar to variation (CV = 0.6%) in mass volume of the 60-1 prototype. The calculated percent body fat (r = 0.851) and fat-free mass (0.962) with some correction of body density were also highly correlated to those determined by underwater weighing. We suggest that SH method may be useful for assessment of human body composition.

Anthropometry↗
PubMed1991

Enhancement of repair of UV-irradiated plasmids in cultured fish cells by fluorescent light preillumination and growth arrest.

The UV-irradiated plasmid pBSCATSV, which could express chloramphenicol acetyltransferase (CAT) in the presence of SV40 early promoter, was transfected into RBCF-1 cells derived from the goldfish (Carassius auratus). The cells were incubated in the dark for 24 h and then the CAT activity was measured. CAT expression relative to non-irradiated control was calculated. The CAT expression of the exponentially growing cells transfected with UV-irradiated plasmid was enhanced by fluorescent light (FL) preillumination of the cells 8 h before transfection. The efficiency of photorepair (PR) measured by CAT expression was also enhanced by the same FL preillumination. This suggests that FL preillumination enhances both photorepair and dark repair of RBCF-1 cells for UV-damaged plasmid transfected into the cells. The enhancement of repair of UV damage by FL preillumination was also observed in survival assays. When the UV-irradiated pBSCATSV was transfected into growth-arrested cells in confluent culture, CAT expression was less sensitive to UV irradiation, and FL preillumination was much less effective in enhancing photorepair and dark repair.

Animals↗
PubMed1991

Preferential excision repair and non-preferential photoreactivation of pyrimidine dimers in the c-ras sequence of cultured goldfish cells.

The time courses of excision repair and photoreactivation of pyrimidine dimers induced by 254-nm UV were examined in the genome overall and in the c-ras sequence of RBCF-1 cells derived from a goldfish, by the use of UV endonuclease of Micrococcus luteus and alkaline agarose gel electrophoresis. Excision repair was more efficient in the ras sequence than in the genome overall, whereas no differences in efficiency of photoreactivation were detected. These results suggest that excision repair is affected by the accessibility of chromatin, while photoreactivation is not.

Animals↗
PubMed1991

Enhancement of photorepair of ultraviolet-damage by preillumination with fluorescent light in cultured fish cells.

Fluorescent light (FL) illumination of RBCF-1 cells, derived from a goldfish, prior to 254 nm UV-irradiation enhanced their ability to photorepair. The cells were illuminated with FL for 1 h (29 W/M2) and incubated for 8 h in the dark before being irradiated with 10 J/m2 UV. The surviving fraction of FL-treated cells after UV-irradiation rose about 7-fold (from 3 to 20%) by 20 min photorepair treatment with the same FL source, whereas 4-fold (from 1.6 to 6%) in the FL non-treated cells. Flow cytometric analysis showed that FL treatment did not affect the distribution of cell cycle phase at the time of UV-irradiation (8 h after FL treatment). Pyrimidine dimers induced by UV were measured by the use of UV endonuclease of Micrococcus luteus and alkaline agarose gel electrophoresis. Initial yields of dimers after exposure to 10 J/m2 UV were almost the same (about 0.11 dimer/kb) between FL treated and non-treated cells. But after 20 min photorepair treatment, about 70% of dimers were removed in the FL treated samples, while less than 20% were removed in the non FL-treated ones.

Animals↗
PubMed1990

An immunohistochemical study of localization of type I and type II collagens in mandibular condylar cartilage compared with tibial growth plate.

Immunohistochemical localization of type I and type II collagens was examined in the rat mandibular condylar cartilage (as the secondary cartilage) and compared with that in the tibial growth plate (as the primary cartilage) using plastic embedded tissues. In the condylar cartilage, type I collagen was present not only in the extracellular matrix (ECM) of the fibrous, proliferative, and transitional cell layers, but also in the ECM of the maturative and hypertrophic cell layers. Type II collagen was present in the ECM of the maturative and hypertrophic cell layers. In the growth plate, type II collagen was present in the ECM of whole cartilaginous layers; type I collagen was not present in the cartilage but in the perichondrium and the bone matrices. These results indicate that differences exist in the components of the ECM between the primary and secondary cartilages. It is suggested that these two tissues differ in the developmental processes and/or in the reactions to their own local functional needs.

Animals↗
PubMed1990

Long-term effects of chincap therapy on skeletal profile in mandibular prognathism.

The purpose of this study was to investigate the long-term changes in the skeletal Class III profile subsequent to chincap therapy. The sample consisted of 63 Japanese girls who had skeletal Class III malocclusions before treatment. All underwent chincap therapy from the beginning of treatment. The duration of chincap therapy varied but averaged 4 1/2 years. The samples were divided into the following three groups according to their ages when chincap therapy was started: A group that started at 7 years of age (n = 23), a group that started at 9 years of age (n = 20), and one that started at 11 years of age (n = 20). The data were derived from lateral cephalometric head films, taken serially at the ages of 7, 9, 11, 14, and 17 years. Skeletal facial diagrams were constructed by X-Y coordinates of representative cephalometric landmarks. The data were analyzed statistically. The results of the present study were as follows: (1) The mandible showed no forward growth during the initial stages of chincap treatment in all three groups. (2) Patients who had entered treatment at 7 and 9 years of age appeared to show a catch-up manner of mandibular displacement in a forward and downward direction before growth was completed. (3) There was no statistical difference in the final skeletal profile between the group that had entered treatment at age 7 and the one that had entered at age 11. In conclusion, the skeletal profile was greatly improved during the initial stages of chincap therapy, but such changes were often not maintained thereafter. This finding indicated that chincap therapy did not necessarily guarantee positive correction of skeletal profile after complete growth.

Cephalometry↗