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Biomedical subjects

H Shibata

Publications and source records attributed to H Shibata.

At least 55 records · Page 3Linked to original sources
PubMed2001

PKNbeta interacts with the SH3 domains of Graf and a novel Graf related protein, Graf2, which are GTPase activating proteins for Rho family.

PKNbeta is a novel isoform of PKNalpha, which is one of the target protein kinases for the small GTPase Rho. By yeast two-hybrid screening of a human embryonic kidney 293 cell cDNA library with the PKNbeta linker region containing proline-rich motifs as a bait, clones encoding Graf (GAP for Rho Associated with Focal adhesion kinase) and a novel Graf-related protein, termed Graf2, were isolated. The full length of Graf2 contains a putative PH domain, a RhoGAP domain, and an SH3 domain as well as Graf. Northern and Western blot analyses demonstrated that Graf2 is expressed in several tissues, with the highest expression in skeletal muscle. Recombinant Graf2 exhibited GTPase-activating activity toward the small GTPase RhoA and Cdc42Hs, but not toward Rac1, in vitro. The SH3 domains of Graf and Graf2 purified from Escherichia coli bound directly to PKNbeta. Graf or Graf2 was co-immunoprecipitated with PKNbeta in COS-7 cells transiently transfected with Graf or Graf2 and PKNbeta expression constructs. The catalytically active form of PKNbeta phosphorylated Graf and Graf2 in vitro. The interplay of PKNbeta and the GTPase-activating proteins, Graf and Graf2, may offer a novel mechanism regulating the Rho-mediated signaling.

Amino Acid Sequence↗
PubMed2001

Cytomorphometric parameters and the metastatic potential of cutaneous and uveal melanoma: a comparison with prognostic factors.

The Mean of the Ten Largest Nuclei (MTLN1) is one of the most important prognostic factors in uveal malignant melanoma. This study was performed to investigate the applicability of nuclear and nucleolar measurements as a prognostic factor for cutaneous melanoma. A routine light microscope (Carl Zeiss: Axiophot EL-Einnsatz; #451888) at 640 times magnification with a Micrometer Eye Piece (Carl Zeiss: #444034) was used to evaluate the correlation of MTLN1 and Mean of Ten Largest Nuclei (MTLN) with the occurrence of metastasis in 58 primary cutaneous melanoma. For uveal melanoma, cytologic classification was used for comparison. Prognostic value was determined by univariate and multivariate linear regression analysis. MTLN1 was the only significant factor for uveal melanoma (p = 0.05). For cutaneous melanoma, all factors were significantly associated with disease progression. MTLN1 was the only one to remain significant (p + 0.027) in multivariate linear regression analysis. Nuclear and nucleolar morphometry are significant prognostic factors for uveal and cutaneous melanoma.

Humans↗
PubMed2001

Association study of polymorphisms in the GluR5 kainate receptor gene (GRIK1) with schizophrenia.

The glutamatergic dysfunction hypothesis suggests genes involved in glutamatergic transmission as candidates for schizophrenia susceptibility genes. We screened single nucleotide polymorphisms (SNPs) in the entire coding sequence of the GluR5 kainate receptor gene, GRIK1, by polymerase chain reaction-single strand conformation polymorphism and direct sequencing. We identified six SNPs including three known ones, 522A/C (174T, synonymous), 1173C/T (391D, synonymous), and 2705C/T (902L/S), as well as three novel ones, 995C/T (332A/V), 2400C/T (800L, synonymous), and 2585A/G (862R/Q). We genotyped Japanese samples of schizophrenia (n = 193-203) and healthy controls (n = 199-215) for three SNPs those were commonly observed in our samples, 522A/C, 1173C/T, and 2705C/T. We observed no significant associations of the SNPs and their haplotypes with schizophrenia. Therefore, we conclude that GRIK1 does not play a major role in schizophrenia pathogenesis in the Japanese population.

Base Sequence↗
PubMed2001

Dynamin is involved in human epithelial cell vacuolation caused by the Helicobacter pylori-produced cytotoxin VacA.

The Helicobacter pylori-produced cytotoxin VacA induces intracellular vacuolation. To elucidate the molecular mechanism of vacuole formation by VacA, we examined the participation of dynamin, a GTPase functioning in intracellular vesicle formation, in human HeLa cells. Immunocytochemistry revealed that endogenous dynamin was localized to vacuoles induced by VacA. In cells transiently transfected with a GTPase-defective (dominant-negative) dynamin mutant, VacA failed to induce vacuolation. In contrast, VacA did induce vacuolation in cells transiently transfected with wild-type dynamin. Furthermore, under VacA treatment, neutral red dye uptake, a parameter of VacA-induced vacuolation, was inhibited in cells stably transfected with the dominant-negative dynamin mutant. In contrast, uptake was markedly enhanced in cells stably transfected with wild-type dynamin. Moreover, VacA cytopathic effects on the viability of HeLa cells were inhibited in cells stably transfected with dominant-negative dynamin-1. Sequential immunocytochemical observation confirmed that expression of dominant-negative dynamin did not affect VacA attachment to or internalization into HeLa cells. We suggest that dynamin is involved in the intracellular vacuolation induced by VacA.

Bacterial Proteins↗
PubMed2001

[Preparation of a gel-forming ointment base applicable to the recovery stage of bedsore and clinical evaluation of a treatment method with different ointment bases suitable to each stage of bedsore].

A novel ointment base suitable for the treatment of bedsore at the recovery stage was developed by the use of hydroxypropyl methylcellulose (HM-HPMC) modified on the basis of the hydrophobicity. A considerable sustained release of drug (minocycline hydrochloride) formulated to the ointment (T50 of 170 min) was attained with a macrogol ointment (MO) mixed with the HM-HPMC and Carbopol (CP) of the formulating ratio of 3:7. It was also found that a change in the formulating ratio of HM-HPMC and CP lead to a change in the drug release rate. The water absorption property of the ointment base, required to absorb on exudative solution in applying to the bedsore treatment, was as high as that of an ointment base containing hydroxypropyl cellulose (HPC) and CP reported in our previous paper. We clinically evaluated the effectiveness of the bedsore treatment, in which different ointment bases were applied to patients at different stages of the bedsore. A total of 22 cases were divided into two categories for applying to the different treatments. One category comprised of 11 subjects was treated with a povidone-iodine sugargel, which was the conventional method in our hospital, while the other 11 subjects were treated by the use of the newly developed ointment bases in consideration for the different stages of the bedsore. In comparison of the clinical results with the healing index, we ascertained that the latter method was significantly more efficacious (p < 0.01-0.05) than the conventional one. The effectiveness was emphasized in treating the intractable bedsore classified into the grades IV and V. Therefore, we confirmed that the newly developed ointment base formulation is useful in treating bedsore at each stage.

Acrylic Resins↗
PubMed2001

Efficient removal of sulfide following integration of multiple copies of the sulfide-quinone oxidoreductase gene (sqr) into the Escherichia coli chromosome.

For the oxidation and removal of hydrogen sulfide, which causes an offensive odor from the contents of animal intestines, recombinant strains of Escherichia coli were constructed. The sulfide-quinone oxidoreductase gene (sqr) from Rhodobacter capsulatus was integrated in low copy numbers into the chromosome of Escherichia coli W3110. Multiple copies of sqr on plasmids were also delivered into the cytoplasm of the same strain. The sqr genes were homologously transducted onto the chromosomal lacZ region and their existence there was verified by Southern blot analysis. Sulfide oxidation in a chemical medium effectively increased for the recombinant strains which carried 2 approximately 3 copies of sqr under the control of the lac or tac promoter in the chromosome, and also for strains which carried 10 copies of sqr under the control of the lac or tac promoter on plasmids. In both types of recombinant, the tac promoter was more effective for SQR expression than the lac promoter. Construction of a recombinant with 3 copies of sqr under the control of the tac promoter in the chromosome was unsuccessful. In recombinants with SQR activity lower than 700 nmol/mg cell protein/min, oxygen consumption increased proportionally to SQR activity. An elevation in SQR activity in this range resulted in an increase in oxygen consumption and a decrease in sulfide concentration. When the recombinant cells were cultured until the 160th generation, WL2, WL3 and WT2, which carried 2, 3 and 2 copies of sqr in the chromosome, respectively, retained SQR activity similar to that of the first generation. For WL300 and WT20 which carried multi-copies of sqr in plasmids SQR activity was undetectable. The recombinant with 2 copies of sqr in the chromosome regulated by the tac promoter was most suitable for sulfide oxidation and growth of the cells.

Journal Article↗
PubMed2001

Effects of chicken essence tablets on resting metabolic rate.

Resting energy expenditure (REE) values after consuming chicken essence tablets were significantly higher than those observed after consuming skim milk protein tablets (control trial). The increased thermogenic effects continued at least for a period of one hour and gradually decreased towards the baseline. The REE values during control treatment did not show such an augmented response.

Administration, Oral↗
PubMed2001

CDNA cloning of feline leptin and its mRNA expression in adipose tissue.

Leptin, the product of the obese (ob) gene, is an adipocyte-derived hormone involved in regulating food intake and energy expenditure in humans and rodents. To determine the primary structure of feline leptin, we cloned the feline leptin cDNA using reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of complementary DNA (cDNA) ends (RACE) methods. The full-length feline leptin cDNA was 2935 bp with a 501 bp open reading frame encoding the precursor peptide of 167 amino acids including 21 residues of signal peptide. The sequence of a 146-amino acid mature leptin was 81.5-91.8% homologous to those of other species. RT-PCR analysis revealed that the leptin mRNA was expressed in adipose tissues and not detected in liver, heart, kidney, lung, pancreas. brain and skeletal muscle. These data show that feline leptin is highly homologous to leptins of other species, and expressed in adipose tissues in cats.

Adipose Tissue↗
PubMed2001

Estrogen therapy in a male patient with chronic hepatitis C and irradiation-induced testicular dysfunction.

We report an 18-year-old male patient who developed chronic hepatitis C after blood transfusion and had testicular dysfunction after irradiation for a testicular relapse of childhood acute lymphocytic leukemia after cessation of maintenance therapy, and the initiation of testosterone replacement therapy at puberty. Concomitant administration of estradiol resulted in a reduction in serum alanine aminotransferase and ferritin levels and hepatic iron concentration and staining after 2 years of estrogen therapy, although interferon therapy was withdrawn because of adverse effects. This observation suggests that endogenous estradiol may play a beneficial role in male patients with chronic hepatitis C.

Adolescent↗
PubMed2001

Effect of oligofucose derivatives on acetic acid-induced gastric ulcer in rats.

This study attempted to enhance the anti-ulcer activity of fucoidan from Cladosiphon okamuranus TOKIDA by chemical modification with a hydrophobic group. The suitable number of fucose residues in the effective compound was also clarified to obtain a compound of constant quality. Degraded fucoidans were coupled with several hydrophobic groups via Schiff bases, and their anti-ulcer activities were determined by acetic acid-induced ulcer models in rats. Size-fractionated oligofucose was also modified and assayed for anti-ulcer activity. Among the modified oligofucoses, only the oligofucose-dodecylaniline combination (OFDA) significantly promoted ulcer healing. The effective dose was 0.2 mg/kg/d. The most suitable number of fucose residues in the compound for the anti-ulcer activity was determined to be around 12. We succeeded in enhancing the anti-ulcer activity of Cladosiphon fucoidan by modification with dodecylaniline. The activity of this compound was comparable or greater than that of typical anti-ulcer agents. By determination of the optimal OF chain length for the anti-ulcer activity of OFDA, it became possible to obtain OFDA of constant quality.

Acetic Acid↗
PubMed2001

Specific gravity of whole blood in cynomolgus monkeys (Macaca fascicularis), squirrel monkeys (Saimiri sciureus), and tamarins (Saguinus labiatus) and total blood volume in cynomolgus monkeys.

Blood collection is a common laboratory procedure in animal experiments. The purpose of this study is to establish baseline data for two essential hematologic parameters, total blood volume (TBV) and specific gravity of blood (SGB), of nonhuman primates. The SGB was determined by dropping samples of whole blood into cupric sulfate solution. The values for the mean SGB +/- 1 standard deviation are: cynomolgus monkeys, 1.0526 +/- 0.0019 [males (n = 39), 1.0531 +/- 0.0017; females (n = 48), 1.0522 +/- 0.001]; squirrel monkeys, 1.0555 +/- 0.0037 [males (n = 56), 1.0581 +/- 0.0027; females (n = 76), 1.0536 +/- 0.0032]; and tamarins, 1.0582 +/- 0.0020 [males (n = 13), 1.0582 +/- 0.0023; females (n = 17), 1.0581 +/- 0.0018]. To determine the TBV, blood was collected in tubes containing 1.5 mg EDTA after intravenous injection of Evans Blue solution. The TBV was obtained after correcting for the hematocrit and the dilution factor of the Evans Blue solution. The formulae were established to estimate TBV by referring to body weight (BW). There was no significance between TBV and BW in male monkeys weighing more than 6 kg.

Animals↗
PubMed2001

Nutritional factors on longevity and quality of life in Japan.

The relationship of nutrient intakes to life expectancies in Japan since the Second World War has demonstrated that sufficient intakes of animal protein and fat are crucial for attaining longevity. In the community dwelling elderly, the higher the serum albumin was, the longer the further life expectancy in the elderly. Serum total cholesterol showed a U-shape relationship to further life expectancies in the elderly. Low serum cholesterol was deleterious for higher levels of functional capacity. Low serum cholesterol and low serum alpha-tochopherol accelerated depressive status in the community dwelling elderly. For reducing malnutrition and for improving nutritional status in undernourished elders, we carried out intervention trials. Instructions on how to prepare ideal daily meals were useful in functionally independent elders because a certain group of Japanese elderly has been stigmatized for eating meat. In frail elders provided with daily meals in a nursing home, a digestive enzyme drug was helpful for enhancing serum albumin levels.

Aged↗
PubMed2001

[Incidence and prognosis of, and risk factors for the home-bound in a community elderly population].

This longitudinal study examined numbers of homebound and bed bound individuals over time, and risk factors in a rural community elderly populations. A total of 731 older persons who needed no assistance of another person in traveling from their homes participated in the baseline survey in 1992 and were assessed annually for their ability to travel for subsequent six-years. We defined operationally a homebound status as the necessity for assistance of another person to be able to leave home, but without being bedbound. During the follow-up period, 86 homebound (23.7 per 1,000 person-years) and 32 bedbound cases (8.4 per 1,000 person-years) were noted, the former being 2.8 times more likely to occur. Of the newly bound cases 26% returned to a state capable of leaving home by themselves one year later, and maintained this independent living level even two years later. Of the other cases who remained as homebound or bedbound one year later, only one (1/31) had returned to independent living after two years; most of them became bedbound at home, hospital admitted or deceased. Stepwise multiple logistic regression analysis showed that independent risk factors for the homebound include older age, male gender, slower walking speed, history of hospital admission in the previous year, lower masticatory ability, and higher level of serum beta 2-microglobin. These results indicate that health promotion programs for prevention of becoming homebound among community elderly people should target more intensively assistance to maintaining walking and masticatory ability. In addition, public health professionals should pay more attention to elderly people shortly after hospital discharge.

Activities of Daily Living↗
PubMed2001

Sulfide oxidation in gram-negative bacteria by expression of the sulfide-quinone reductase gene of Rhodobacter capsulatus and by electron transport to ubiquinone.

The oxidation of sulfide was studied in recombinant bacteria expressing the sulfide-quinone reductase gene (sqr) from Rhodobacter capsulatus. Sulfide was oxidized by the Escherichia coli strain W3110 harboring the sqr construct (pKKSQ) under anaerobic conditions and nitrate was utilized as a terminal electron acceptor. Following the oxidation, elemental sulfur and nitrite were produced as the final reaction products. This activity was retained in the membrane preparation and was sensitive towards antimycin A, stigmatellin, and azide. As a consequence of the ubiquinone deficiency, this activity was markedly decreased. In additon, by recovery of ubiquinone, the oxidation was also restored to rates similar to those of the wild-type strain. These results indicate that sulfide oxidation in this strain occurs via the quinone pool in vivo, and that this sulfide-quinone reductase (SQR) in particular utilizes ubiquinone as a more appropriate electron acceptor than menaquinone or demetylmenaquinone. To our knowledge, this is the first study to show a direct interaction between SQR and ubiquinone in cells. When expressed in Pseudomonas putida and Rhizobium meliloti, the SQR conferred on these organisms the ability to oxidize sulfide as well as E. coli in vivo.

Anaerobiosis↗
PubMed2001

[What characteristics have the elderly who contact friends at hospitals?].

PURPOSES: The purposes of this study are to examine two points; 1) What effects do regular visits to hospitals have on the existence of friend?. and 2) Do the elderly use hospitals as substitutes for other meeting places or independent of other places?. METHODS: Data concerning 2,447 older adults were obtained from a national survey for the elderly aged 60 and over, conducted in 1996. 1) To examine effects of regular visits to hospitals on friends, friendships as a dependent variable, regular visits to hospitals as a confounding variable, and some two way-interaction terms as independent variables were entered in logistic regression analysis. 2) To analyze relationships between hospitals and other meeting places, correspondence analyses and logistic regression were used. 3) Existence of friends whom the elderly contact at hospitals as a dependent variable, existence of friends whom they meet at other places as a confounding variable, and some two way-interaction terms as independent variables were entered in logistic regression analysis. 3) Relationships between clinics and other meeting places were also analyzed using correspondence analyses and logistic regression. RESULTS: 1. Although regular visits to hospitals did not have a significant direct impact on existence of friends, the respondents with low activities of daily living who regularly visits hospitals were more likely to have friends than ones did not visits hospitals. 2. The respondents who meet friends at hospitals were also more likely to have contacts with friends at community centers for the elderly or community organization. 3. The respondents who meet friends at clinics had similar characteristics to those who meet friends at hospitals. CONCLUSIONS: Regular visits to hospitals may contribute to maintain contacts with friends, especially in the elderly with low ADL. The elderly may use hospitals as meeting places with friends independent of other places. Hospitals may have similar functions to what clinics as meeting places with friends.

Activities of Daily Living↗
PubMed2001

Sentinel lymph-node biopsy for melanoma of the trunk and extremities: the McGill experience.

OBJECTIVE: To determine the effectiveness of sentinel lymph-node (SLN) biopsy for melanoma of the trunk and extremities. DESIGN: Case series review. SETTING: Royal Victoria Hospital, a Canadian university hospital. PATIENTS: Thirty-six patients (18 women and 18 men) seen between October 1996 and December 1998 with melanoma 1 mm or more in thickness with clinically negative lymph-node basins. Follow-up was 396 days. INTERVENTIONS: SLN biopsy. Technetium-99m filtered sulfur colloid (0.5 mCi) was injected intradermally around the melanoma or the excision scar 10 to 15 minutes before the surgical skin preparation. The identification of the SLN(s) was done with a hand-held gamma probe. Local anesthesia was used mostly for inguinal SLN biopsy whereas general anesthesia was usually required for axillary SLN biopsy. Preoperative lymphoscintigraphy was used only for trunk melanomas. OUTCOME MEASURES: Morbidity, successful identification of the sentinel node and locoregional recurrence. RESULTS: The mean age of patients at diagnosis was 53.4 years (range from 22-76 yr). The melanomas were distributed between the lower extremities (20 patients), upper extremities (8 patients) and trunk (8 patients). The mean Breslow thickness was 2.35 mm (range from 1-8 mm). Lymphoscintigraphy accurately localized the lymph-node drainage basin for trunk melanomas. In 1 patient the SLN could not be identified because the radiocolloid failed to migrate (failure rate 2.8%). The average number of SLNs removed was 1.97. Eight patients (22%) had sentinel nodes positive for malignant disease. The postoperative complication rate was 8.5%. Seven of 8 patients with positive SLNs underwent a complete node dissection (1 patient refused). Of the completion dissections only 2 patients had positive non-SLNs. All patients with positive nodes received interferon alpha-2b as adjuvant treatment. At follow-up, 34 patients are alive with no evidence of disease, 1 patient with a positive SLN is alive with distant metastatic disease and 1 patient with a negative SLN is dead of disseminated disease. CONCLUSION: SLN biopsy is a feasible technique with an acceptable failure rate and is thus a useful tool in the surgical management of melanoma.

Adult↗