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Biomedical subjects

H Shimizu

Publications and source records attributed to H Shimizu.

At least 199 records · Page 11Linked to original sources
PubMed2001

An immunohistological study on cyclooxygenase-2 in human dental pulp.

Characteristics of cyclooxygenase-2 (COX-2) expressing cells in human dental pulp were immunohistologically studied. Extirpated pulpal tissues from extracted teeth were examined to elucidate the localization and distribution of COX-2. Pulpal tissues were examined by the labeled streptavidin biotin method using specific mouse monoclonal antibodies for COX-2. Cell types of the COX-2 expressing cells were also investigated by the double stain technique using both monoclonal antibodies for CD68/macrophage and anti-COX-2. COX-2 expressing cells could be found in all of the inflamed pulps, and these cells were mostly distributed close to the area of accumulation of inflammatory cells. COX-2 was mainly expressed in fibroblasts rather than macrophages. In contrast, COX-2 expressing cells were scarcely found in the normal pulps. These findings indicate that pulpal fibroblasts, as well as macrophages, may participate in the production of prostaglandin through COX-2 expression in pulpal inflammation, and might be involved in the pathogenesis of irreversible pulpitis.

Adult↗
PubMed2001

Tyrosine hydroxylase antisense gene therapy causes hypotensive effects in the spontaneously hypertensive rats.

We investigated the effect of antisense oligodeoxynucleotides (AS ODN) against tyrosine hydroxylase (TH) on hypertension and sympathetic nervous system activity in spontaneously hypertensive rats (SHR). Systolic blood pressure (SBP) in SHR treated with TH AS ODN (50, 200 microg/rat, i.v.) was significantly lower than that of control SHR. Epinephrine and norepinephrine levels, TH activity, and TH protein levels in the adrenal medulla of SHR were reduced concomitant with TH AS ODN treatment-induced changes in SBP. In contrast, TH AS ODN (200 microg/rat) had no effect on SBP in Wistar-Kyoto rats (WKY), despite significantly decreased catecholamine levels, TH activity, and TH protein levels. These findings suggest that peripheral systemic injection of TH AS ODN may be effective as hypotensive therapy in SHR.

Adrenal Medulla↗
PubMed2001

Automatic scoliosis detection based on local centroids evaluation on moiré topographic images of human backs.

This paper presents a technique for automating human scoliosis detection by computer based on moiré topographic images of human backs. Scoliosis is a serious disease often suffered by teenagers. For prevention, screening is performed at schools in Japan employing a moiré method in which doctors inspect moiré images of subjects' backs visually. The inspection of a large number of moiré images collected by the school screening causes exhaustion of doctors and leads to misjudgment. Computer-aided diagnosis of scoliosis has, therefore, been requested eagerly by orthopedists. To automate the inspection process, unlike existent three-dimensional techniques, displacement of local centroids is evaluated two-dimensionally between the left-hand side and the right-hand side of the moiré images in the present technique. The technique was applied to real moiré images to draw a distinction between normal and abnormal cases. According to the leave-out method, the entire 120 image data (60 normal and 60 abnormal) were separated into three data sets. The linear discriminant function based on Mahalanobis distance was defined on the two-dimensional feature space employing one of the data sets containing 40 moiré images and classified 80 images in the remaining two sets. The technique finally achieved the average classification rate of 88.3%.

Algorithms↗
PubMed2001

Desmosomes: structure and function in normal and diseased epidermis.

Desmosomes are important epidermal adhesion complexes that are characterized by a cell-specific expression of transmembrane cadherins and plaque-associated molecules. Desmosomes have so far, been implicated in three main disease types: autoimmune diseases that involve desmosome components (such as pemphigus vulgaris and pemphigus foliaceus), congenital diseases that affect intracellular calcium channels (such as Hailey-Hailey disease and Darier disease) and congenital diseases that directly affect desmosomal structural components. The identification of the first congenital defect affecting a desmosome component was in the gene for plakophilin I which caused an autosomal recessive skin fragility-ectodermal dysplasia syndrome with skin, hair and nail defects. Subsequently, either a haploinsufficiency of desmoplakin or a defect in desmoglein 1 was found to underlie the autosomal dominant condition Striate Palmoplantar Keratoderma. In addition, plakoglobin has been shown to be defective in Naxos disease, which results in a cardiomyopathy and growth of abnormal hair. These findings pave the way for the discovery of further cell cohesion-related diseases and will help to greatly increase our understanding of the specific function of desmosome and other epithelial junction components.

Animals↗
PubMed2001

Suicide gene therapy for chemically induced rat bladder tumor entailing instillation of adenoviral vectors.

The efficacy of an in vivo gene therapy protocol making use of an adenoviral vector in the treatment of bladder cancer was examined. Bladder tumors were induced in rats by oral administration of BBN (N-butyl-N-(4-hydroxybutyl)nitrosamine). Histologically, such tumors resemble those seen in human bladder cancer, and the cells can be selectively transduced using adenoviral vectors. The therapeutic protocol thus entailed instillation of an adenoviral vector containing the HSV-tk suicide gene into rat bladder followed by a regimen of intraperitoneal ganciclovir (GCV) injections. Histological examination after a short-term GCV regimen (3 days) revealed marked vacuolization of the tumor cells. Moreover, TUNEL assays showed that the cytotoxic reaction was mediated by apoptosis. Following a long-term GCV regimen (14 days), tumor growth was significantly inhibited and glandular metaplasia was observed. This is the first report demonstrating the efficacy of in vivo suicide gene therapy in a chemically induced transitional cell carcinoma like that seen in most human bladder cancer. Intravesical instillation is already a well established clinical technique. Our findings indicate that now there is a strong potential for its incorporation into new and useful gene therapies aimed at the treatment of human bladder cancer.

Adenoviridae↗
PubMed2001

Nonsurgical management of ruptured pseudoaneurysm in patients with hepatobiliary pancreatic diseases.

OBJECTIVE: Rupture of a pseudoaneurysm is an unusual complication after surgical and interventional treatments in patients with hepatobiliary pancreatic diseases. However, it occurs abruptly and often results in a lethal outcome. The aim of this study was to retrospectively analyze our experiences of cases of rupture of pseudoaneurysms for providing appropriate therapeutic planning. METHODS: Between 1985 and 1998, we observed ruptures of pseudoaneurysms in 14 of 910 patients with hepatobiliary pancreatic diseases--six after pancreaticoduodenectomy, three after hepatic resection, two after hepatopancreaticoduodenectomy, two after percutaneous transhepatic biliary drainage, and one after gastrojejunostomy. Thirteen of the 14 patients underwent emergency angiography and transcatheter arterial embolization (TAE) or infusion therapies, and one of the 13 patients underwent surgical hemostasis because of incomplete hemostasis with TAE. The other patient, who did not undergo emergency angiography, had surgical hemostasis initially. RESULTS: TAE achieved hemostasis in 11 of 13 patients (85%), but only incomplete hemostasis in the remaining two patients. Of these two patients, one underwent laparotomy, but died of multiple organ failure (MOF) at 6 days after surgical hemostasis. The other died at 1 day after emergency angiography. Ten of 11 patients who obtained complete hemostasis by means of TAE could later be discharged, but one patient died of liver failure, and/or MOF. One patient who underwent laparotomy initially without angiography died of MOF at 43 days after the operation. The onset of rupture of a pseudoaneurysm was a mean of 35.4 days (range 12-76) after surgical or interventional procedures. The warning prodromal symptoms were upper abdominal oppression, nausea, and backache before the rupture of pseudoaneurysms. Fever, leukocytosis. hyperbilirubinemia, anastomotic leak, and intraabdominal abscess were frequent persistent signs in these patients. CONCLUSIONS: If the warning prodromal symptoms appear in patients along with these persistent signs, the impending rupture of pseudoaneurysms should be suspected. Thereafter, a diagnostic angiography should be performed immediately to enable early diagnosis and embolization therapy for rupture of pseudoaneurysms when hemorrhagic episodes appear in these patients. Early detection and immediate embolization might bring about a favorable outcome in patients with hepatobiliary pancreatic diseases who encounter rupture of pseudoaneurysms after surgical and interventional treatments.

Adult↗
PubMed2001

[Evaluation of immunochromatography based rapid detection kit of rotavirus and adenovirus].

We investigated the usefulness of Rapidtesta Rota-Adeno (Daiichi Pure Chemicals Co., Ltd., Japan) for rapid detection of group A rotavirus and adenovirus simultaneously using immunochromatography with clinical samples. In investigation of the reaction of the kit to 5 strains of group A rotavirus, 13 strains of adenovirus and other intestinal viruses, specific lines were formed in red to group A rotavirus and blue to adenovirus. No cross reaction was observed with other intestinal virus. In measurement of detection limit, group A rotavirus (SA11) was detected at 10(4.4)TCID50/ml, serotype 3 adenovirus at 10(4.45)TCID50/ml. The detection limit of the kit was similar to other immunochromatographic assay or enzyme immnoassay kits and approximately 10 times higher than that of kits using latex agglutination test. In comparison with other testing kits in clinical samples, the concordance with other immunochromatographic assay was 99.2% (121/122) in group A rotavirus and 98.6% (138/140) in adenovirus. The rate of concordance with latex agglutination test kit was 94.5% (69/73) in group A rotavirus and 92.3% (84/91) in adenovirus. The kit had high rates of concordance with other immunochromatographic assay kits and higher virus detection rates than those of latex agglutination test kits. Rapidtesta Rota-Adeno is able to detect group A rotavirus and adenovirus simply and rapidly. In addition, the two kinds of virus can be easily differentiated by color difference in reaction lines, suggesting that the kit is useful in clinical diagnosis.

Adenoviridae↗
PubMed2001

[Clinical evaluation of an immunochromatography test for rapid diagnosis of influenza].

We evaluated a rapid diagnostic kit that detects influenza type A and B viral antigens by immunochromatography, Quick Vue Influenza Test (Quidel Corp., San Diego, CA, USA), with 425 specimens collected from patients with influenza-like symptoms at three hospitals between January and March 2001. The specimens included 184 nasal aspirates, 140 nasal swabs, and 101 throat swabs. The test correctly identified 179 of the 204 culture positive specimens and 203 of the 221 culture negative specimens; the sensitivity and specificity compared with the culture were 87.7% and 91.9%, respectively. The sensitivity of the test was 92.6% (112/121) for nasal aspirates, 83.7% (41/49) for nasal swabs, and 76.5% (26/34) for throat swabs, which is similar to the results for conventional rapid enzyme immunoassay kits for influenza virus infection. The sensitivity and specificity of the QuickVue Influenza Test were equivalent to those of Flu OIA (BioStar, Inc., Boulder, CO, USA), with the agreement of 84.2%. Although the QuickVue Influenza Test does not differentiate between influenza A and B viruses, the easy-to-use kit detects both types in the physician's office, allowing physicians to make a decision on prescription of neuraminidase inhibitor therapy during the initial visit.

Evaluation Studies as Topic↗
PubMed2001

[Evaluation of immunochromatography method for rapid detection of influenza A and B viruses].

We have evaluated a new rapid detection kit for influenza A and B viruses, known as the QuickVue Influenza test (Quidel Coporation, USA); which is based on immunochromatography using virus isolates and clinical specimens. Twelve strains of influenza A and B were tested for evaluate the reactivity and detection limits of this test. The QuickVue Influenza test showed a positive result for all twelve strains of influenza virus and a negative result for fourteen different kinds of other respiratory viruses. The detection limits for six strains were 5 to 30 pfu/ml for a cell culture, 1.0 x 10(3) to 6.0 x 10(4) pfu/ml for 1st PCR, 1 to 50 pfu/ml for nested PCR, 3.0 x 10(5) to 6.0 x 10(5) pfu/ml for the QuickVue Influenza test, 1.5 x 10(5) to 1.0 x 10(6) pfu/ml for the Directigen Flu A, and 7.5 x 10(5) to 5.0 x 10(6) pfu/ml for the FLU OIA. Furthermore, the QuickVue Influenza test were clinically evaluated using 92 throat swab specimens collected from patients with influenza-like illnesses. By cell culture, influenza viruses were detected in 49 of the 92 specimens (AH1N1: 20, AH3N2: 7, B: 22); the titers of the influenza viruses were between 2.5 pfu/ml and 7.0 x 10(5) pfu/ml. Compared to cell culture, the QuickVue Influenza test showed a sensitivity of 75.5%, a specificity of 93.0%, a positive predictive value of 92.5%, a negative predictive value of 76.9%, and an efficiency value of 83.7%. On the other hand, influenza viruses were detected in 54 of the 92 specimens (AH1N1: 19, AH 3N2: 10, B: 25) by RT-PCR. Compared to RT-PCR, the QuickVue Influenza test showed a sensitivity of 72.2%, a specificity of 97.4%, a positive predictive value of 97.5%, a negative predictive value of 71.2%, and an efficiency value of 82.6%. Overall, only one throat swab specimen produced a false positive result using the QuickVue Influenza test; thus, this test appears to have a high specificity. We conclude that the QuickVue Influenza test is a simple one-step test with a sensitivity and specificity equivalent to those of other conventional diagnostic kits. The test is useful and suitable for the diagnosis of influenza and for identifying influenza patients requiring antiviral therapy.

Influenza A virus↗
PubMed2001

Overexpression of yccL (gnsA) and ydfY (gnsB) increases levels of unsaturated fatty acids and suppresses both the temperature-sensitive fabA6 mutation and cold-sensitive secG null mutation of Escherichia coli.

A multicopy suppressor of the cold-sensitive secG null mutation was isolated. The suppressor contained sfa and yccL, the former of which has been reported to be a multicopy suppressor of the fabA6 mutation carried by a temperature-sensitive unsaturated fatty acid auxotroph. Subcloning of the suppressor gene revealed that yccL, renamed gnsA (secG null mutant suppressor), was responsible for the suppression of both the secG null mutation and the fabA6 mutation. In contrast, the sfa gene did not suppress the fabA6 mutation. The ydfY (gnsB) gene, encoding a protein which is highly similar to GnsA, also suppressed both the secG null mutation and the fabA6 mutation. Although both gnsA and gnsB are linked to cold shock genes, the levels of GnsA and GnsB did not exhibit a cold shock response. A gnsA-gnsB double null mutant grew normally under all conditions examined; thus, the in vivo functions of gnsA and gnsB remain unresolved. However, overexpression of gnsA and gnsB stimulated proOmpA translocation of the secG null mutant at low temperature and caused a significant increase in the unsaturated fatty acid content of phospholipids. Taken together, these results suggest that an increase in membrane fluidity due to the increase in unsaturated fatty acids compensates for the absence of the SecG function, especially at low temperature.

Bacterial Outer Membrane Proteins↗
PubMed2001

Effects of estrogen on serum leptin levels and leptin mRNA expression in adipose tissue in rats.

OBJECTIVE: In this study, we examined changes in serum leptin levels during the estrus cycle and the role of estrogen in these changes. METHODS: We measured serum leptin levels during normal estrus cycles in intact rats and estradiol-17beta (E2)-induced artificial estrus cycles in ovariectomized rats. RESULTS: Serum leptin levels increased 1.6-fold from 4.2 +/- 0.2 ng/ml during diestrus stage 2 to 6.7 +/- 0.9 ng/ml during proestrus stage during the 4-day estrus cycle. During the E2-induced estrus cycle, serum leptin levels increased 2.3-fold from 2.3 +/- 0.1 ng/ml at estrus to 5.4 +/- 1.2 ng/ml at proestrus. E2 also increased serum leptin concentrations and leptin mRNA expression in adipose tissue of immature rats. DISCUSSION: These findings suggest that increased serum leptin induced by estrogen during proestrus may trigger the preovulatory release of luteinizing hormone. Furthermore, our findings indicate that estrogen has a positive effect on leptin production in adipose tissue.

Adipose Tissue↗
PubMed2001

Doppler echocardiography-derived index of myocardial performance (TEI index): comparison with brain natriuretic peptide levels in various heart disease.

Plasma brain natriuretic peptide (BNP) has diagnostic and prognostic value in heart failure. Cardiac dysfunction varies from systolic or diastolic dysfunction alone to the combination of both. In the present study, Doppler echocardiographic parameters, including the Doppler echocardiography-derived index (TEI index), were compared with plasma BNP levels in 74 patients with various heart diseases. Blood sampling was performed before an echocardiographic examination was conducted. The TEI index was defined as the summation of isovolumic contraction and relaxation time divided by ejection time. In patients with left ventricular (LV) systolic dysfunction (ejection fraction <50%), the TEI index and BNP were increased significantly compared with patients with normal LV systolic function (p<0.05). Patients with a TEI index > or =0.45 showed significantly increased BNP levels compared with patients with a TEI index <0.45, irrespective of LV systolic function (241.4+/-451.2 vs 65.9+/-81.8pg/ml; p<0.05). The TEI index was significantly higher in patients with a BNP > or =73pg/ml than in patients with BNP <73pg/ml (0.57+/-0.24 vs 0.46+/-0.17; p<0.05). Other echocardiographic parameters did not correlate significantly with levels of plasma BNP. Of the echocardiographic parameters, a simple Doppler index (TEI index) that combines systolic and diastolic function can detect LV dysfunction in patients with high levels of plasma BNP in various heart diseases.

Adolescent↗
PubMed2001

Involvement of tyrosine hydroxylase upregulation in cyclosporine-induced hypertension.

To identify the mechanism of cyclosporine-induced hypertension, we studied the effect of cyclosporine on the catecholamine synthetic pathway in rats. We administered cyclosporine (10 mg/kg per day, s.c.) for 3 days to 10-week-old male Wistar rats. Systolic blood pressure increased significantly in the cyclosporine-treated group in comparison to that in the control group. Norepinephrine and epinephrine levels in the adrenal medulla and plasma of cyclosporine-treated rats were also significantly higher than levels in the control rats. Moreover, tyrosine hydroxylase (TH) activity and TH mRNA expression in the adrenal medulla of cyclosporine-treated rats were significantly elevated. Administration of the TH inhibitor alphamethyl-p-tyrosine (200 mg/kg, b.i.d., s.c.) for 3 days significantly suppressed cyclosporine-induced increases in systolic blood pressure. Phosphorylation of cyclic AMP responsive element-binding protein (CREB) and its binding activity to DNA in the nuclear fraction from the adrenal medulla of cyclosporine-treated rats were much higher than that of the control rats. Calcineurin protein expression of cyclosporine-treated rats was less than that of the control rats. These results suggest that cyclosporine increased blood pressure via activation of the catecholamine synthetic pathway due to the activation of transcription factor CREB.

Adrenal Medulla↗
PubMed2001

Improvement of freezing tolerance in transgenic tobacco leaves by expressing the hiC6 gene.

A cryoprotective protein, HIC6, was expressed transgenically in tobacco, a cold-sensitive plant, and the localization of the protein within the cell as well as freezing tolerance of the transgenic tobacco was investigated. For constitutive expression of HIC6 in tobacco, its corresponding gene was subcloned into pBI121. Through the transformation with pBI121/hiC6, fifteen transgenic tobacco lines were acquired, out of which twelve lines expressed the HIC6 protein. None of the transgenic tobacco lines, however, showed significant differences in freezing tolerance from the control plants (wild-type and transformed with pBI121) at -1, -3, and -4 degrees C, with the exception that their freezing temperature was -2 degrees C. In order to increase the accumulation level of HIC6, pBE2113 with a stronger promoter was used. Eight lines expressed the protein out of thirteen lines transformed with pBE2113/hiC6. The accumulation levels of the protein were clearly higher in the tobacco plants transformed with pBE2113/hiC6 than in those with pBI121/hiC6. The HIC6 protein seemed to be localized in mitochondria of the transgenic tobacco plants. Freezing-tolerance tests at -1 - -4 degrees C showed that the degree of electrolyte leakage was significantly lower in the plants with pBE2113/hiC6 than in the control plants. A leaf browning observation also showed that high accumulation of HIC6 significantly suppressed injury caused by freezing to the transgenic tobacco at -3 degrees C.

Algal Proteins↗
PubMed2001

Detection and identification of subcutaneous adipose tissue protein related to obesity in New Zealand obese mouse.

New Zealand obese (NZO) mouse, a genetic model of obesity, shows hyperphagia, hyperinsulinemia and leptin resistance. We analyzed subcutaneous adipose tissue proteins in NZO mice with a two-dimensional gel electrophoresis technique followed by protein sequence analysis. NZO mice showed hyperinsulinemia and hyperleptinemia. Abdominal subcutaneous adipose tissue was inspected in NZO and C57BL/6J lean mice. Two-dimensional gel electrophoresis detected 4 spots which were obviously reduced in NZO mice. Those spots were p26, p19, p18 and p15. Internal sequences of the p26 and p15 protein were homologous with those of carbonic anhydrase III, p19 was cytochrome b5, p18 was superoxide dismutase. Serum arachidonic acid level in NZO mice was lower by 80% of C57BL/6J mice. The present study demonstrated the reduction of several enzymes related to lipid metabolism in NZO mice. These data raises the hypothesis that the supposed changes of membrane fluidity caused by altered membrane lipid content may involve central leptin resistance of this model of obesity.

Adipose Tissue↗
PubMed2001

Effects of family-togetherness on the food selection by primary and junior high school students: family-togetherness means better food.

To see how different foods were selected depending on family-togetherness at breakfast and dinner, we investigated the meals of eight thousand primary and four thousand junior high school students by questionnaire. About 70% of primary school children but less than 50% of junior high school children ate breakfast with their family. The food, eaten by children who ate meals together with their family, took more time for cooking and was more traditional with rice as the staple. Food eaten by children who did not eat with their family lacked both preparation time and staple base. Family-togetherness affects the foods of primary school children more than those of junior high school students.

Child↗
PubMed2001

Cellular localization of the diazepam binding inhibitor (DBI) in the gastrointestinal tract of mice and its coexistence with the fatty acid binding protein (FABP).

The diazepam binding inhibitor (DBI), initially isolated as an endogenous 10-kDa polypeptide from the brain, has the ability to displace ligands from benzodiazepine binding sites on gamma-aminobutyric acid (GABA) receptors. However, DBI is widely distributed outside the brain, with the highest expression in the intestine. The present in situ hybridization study revealed the cellular expression of DBI mRNA throughout the gastrointestinal tract of mice, showing it to be intensely expressed in the spinous layer in the stratified squamous epithelium of the oral cavity, esophagus and forestomach, in surface mucous cells in the glandular stomach, and in columnar (absorptive) cells of the intestinal villi. A precise identification of DBI-expressing cell types was confirmed immunohistochemically, although the expressing cells detectable by the two histochemical methods differed slightly in their extension. Noteworthily, DBI always coexisted with the fatty acid binding protein (FABP), which participates in the uptake and metabolic processing of long chain fatty acids. In addition to the biochemical finding that DBI is identical with the acyl-CoA binding protein (ACBP), the distributional patterns of DBI and its colocalization with FABPs suggests its involvement in the absorption and metabolism of lipid in the epithelia of the digestive tract.

Animals↗