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Biomedical subjects

Shuichi Sato

Publications and source records attributed to Shuichi Sato.

At least 19 recordsLinked to original sources
PubMed2007

Effects of ipriflavone on augmented bone using a guided bone regeneration procedure.

: This study investigated the effects of ipriflavone (IP) on augmented bone using a guided bone regeneration (GBR) procedure. In 15 rabbits, two titanium caps were placed into calvarial bone for GBR. The animals were divided into three groups: the No-IP (no intake of IP), Post-IP (IP orally, 10 mg/kg/day after GBR), and Pre-IP (IP intake beginning before GBR) groups. One cap was removed from each rabbit after 3 months, and the remaining site was a control. One month after one cap removal, all the animals were euthanized, and histologic and histomorphometric analyses were performed. In all of the groups, the newly generated tissue was of varying size, and it consisted of thin pieces of mineralized bone and large marrow spaces with fat cells and some hematopoietic cells. In all of the control sites, the newly generated tissue was noted and almost filled the space under the cap. There was a significant difference between groups No-IP and Pre-IP (93.8+/-4.6% vs. 98.5+/-0.8%, P<0.05). The tissue generated at the test sites in all of the groups was resorbed, and its original shape and volume were not maintained 1 month after one cap removal. In particular, the greatest percentage, approximately 20% of the newly generated tissue, was resorbed in the No-IP group (93.8+/-4.6% vs. 73.9+/-3.7%, P<0.05), and approximately 11% and 15% in groups Post-IP and Pre-IP, respectively. The relative amount of mineralized bone generated at the control and test sites was significantly larger in groups Post-IP and Pre-IP when compared with group No-IP, except for the test site between groups No-IP and Post-IP (P<0.05). Therefore, the amount of mineralized tissue generated appeared to increase with an increase in the total IP dose. Within the limitations of this rabbit experimental model, we conclude that the daily intake of IP before or after GBR inhibits the resorption of augmented tissue and would be useful for improving the quality of newly generated bone beyond the skeletal envelope.

Adipose Tissue↗
PubMed2007

Pharmacological characterization of a new antimuscarinic agent, solifenacin succinate, in comparison with other antimuscarinic agents.

Solifenacin succinate [YM905; (3R)-1-azabicyclo[2.2.2]oct-3-yl(1S)-1-phenyl-3,4-dihydroisoquinoline-2(1H)-carboxylate monosuccinate] is a new muscarinic receptor antagonist developed for the treatment of overactive bladder. The aim of the present study was to evaluate the antimuscarinic properties of solifenacin and to compare the results with those obtained for tolterodine, oxybutynin, darifenacin, propiverine and atropine. In radioligand receptor binding assay, Ki values of solifenacin for human muscarinic M1, M2, M3, M4 and M5 receptors were 26, 170, 12, 110 and 31 nM, respectively. In isolated rat urinary bladder, solifenacin competitively antagonized carbachol-induced contractions, with a pA2 value of 7.44+/-0.09. In these in vitro studies, the antimuscarinic action of solifenacin was more potent than that of propiverine and less potent than those of tolterodine, oxybutynin, darifenacin and atropine. In anesthetized rats, solifenacin and oxybutynin increased the maximum bladder capacity in a dose-dependent manner and also decreased the maximum intravesical pressure. The dosages required to produce a 30% increase in maximum bladder capacity (ED30 values) of solifenacin and oxybutynin were 0.35 and 0.30 mg/kg i.v., respectively, indicating approximately equal efficacies. These results support the fact that solifenacin, similarly to currently used antimuscarinic agents, is an effective agent in the treatment of overactive bladder symptoms such as urinary frequency and urge incontinence.

Animals↗
PubMed2006

Interferometers for displacement-noise-free gravitational-wave detection.

We propose a class of displacement- and laser-noise-free gravitational-wave-interferometer configurations, which does not sense nongeodesic mirror motion and laser noise, but provides a nonvanishing gravitational-wave signal. Our interferometers consist of four mirrors and two beam splitters, which form four Mach-Zehnder interferometers. By contrast to previous works, no composite mirrors with multiple reflective surfaces are required. Each mirror in our configuration is sensed redundantly, by at least two pairs of incident and reflected beams. Displacement- and laser-noise-free detection is achieved when output signals from these four interferometers are combined appropriately. Our 3-dimensional interferometer configuration has a low-frequency response proportional to f2, which is better than the f3 achievable by previous 2-dimensional configurations.

Journal Article↗
PubMed2006

Effect of tamsulosin on spontaneous bladder contraction in conscious rats with bladder outlet obstruction: comparison with effect on intraurethral pressure.

We investigated the effect of tamsulosin, an alpha(1)-adrenoceptor antagonist, on bladder function, especially spontaneous bladder contractions before micturition (premicturition contraction), in conscious rats with bladder outlet obstruction induced by partial urethral ligation, and compared the results with the effect on intraurethral pressure response in anesthetized rats. In obstructed rats, the alpha(1)-adrenoceptor antagonists tamsulosin, naftopidil and urapidil and non-selective alpha-adrenoceptor antagonist phentolamine inhibited premicturition contractions in a dose-dependent fashion. In contrast, yohimbine, an alpha(2)-adrenoceptor antagonist, and atropine, a muscarinic receptor antagonist, hardly inhibited them. Tamsulosin and urapidil showed clearly inhibitory effects on increases in intraurethral pressure induced by phenylephrine, an alpha(1)-adrenoceptor agonist, in the same dose range as that at which they inhibited premicturition contractions, whereas naftopidil required somewhat higher doses to inhibit increases in intraurethral pressure than those at which it inhibited premicturition contractions. In conclusion, premicturition contractions observed in obstructed rats were sensitive to alpha(1)-adrenoceptor antagonists, but not to alpha(2)-adrenoceptor or muscarinic receptor antagonists. Tamsulosin was shown to be effective against both premicturition contraction and intraurethral pressure response in the same dose range in rats. These results partly support the fact that tamsulosin has improved storage symptoms as well as voiding symptoms in patients with lower urinary tract symptoms associated with bladder outlet obstruction by blocking alpha(1)-adrenoceptors.

Animals↗
PubMed2006

Participation of endogenous endothelin and ETA receptor in premicturition contractions in rats with bladder outlet obstruction.

A relationship between endogenous endothelins and bladder overactivity has recently been suggested, but the related endothelin receptor subtype has not been identified. Here, to evaluate the involvement of endothelin-1 and its receptors in bladder overactivity, we investigated endothelin-1 levels and the expression of its receptors in the bladder of rats with bladder outlet obstruction (BOO), a model for bladder overactivity. We also investigated the effects of a selective endothelin ET(A) receptor antagonist, (E)-N-[6-methoxy-5-(2-methoxyphenoxy)[2,2'-bipyrimidin]-4-yl]-2-phenylethenesulfonamide monopotassium salt (YM598), on bladder functions in conscious BOO rats. Partial obstruction of the urethra led to a progressive increase in bladder weight from weeks 1 to 6. Binding assays performed using plasma membranes prepared from these bladders to estimate endothelin receptor density from the maximum [(125)I]endothelin-1 binding showed increased endothelin receptor density (about double) at 1, 2, and 6 weeks after the operation in the BOO bladder. The densities of endothelin ET(A) receptors in the bladder of sham-operated and BOO rats at 2 weeks after operation were about 3.5 and 5 times those of endothelin ET(B) receptors respectively. Furthermore, the endothelin-1 level was also increased in the BOO bladder. Two weeks after operation, BOO rats showed an increase in maximum bladder capacity and micturition volume and the generation of premicturition contractions. The frequency of premicturition contractions was dose-dependently reduced by YM598 (0.1-3 mg/kg, i.v.) without any effect on other voiding parameters in BOO rats. These data suggest that endothelin-1 and endothelin ET(A) receptors might be involved in the generation of premicturition contractions in BOO rats, and that endothelin ET(A) receptor antagonists such as YM598 may have ameliorating effects in patients with bladder overactivity associated with BOO.

Animals↗
PubMed2006

Bite force and occlusal contact area changes following mandibular widening using distraction osteogenesis.

OBJECTIVE: To examine changes in bite force and occlusal contact area after mandibular widening by distraction osteogenesis using pressure-sensitive sheet (Dental-Prescale; Fuji Photo Film, Tokyo, Japan). STUDY DESIGN: Fifteen patients with transverse mandibular deficiency (6 to 9 mm, mean distraction interval: 8 mm) were examined. They were measured just before the operation and at 1 week, 1 month, 3 months, 6 months, and 1 year after the operation. Ten control subjects with normal occlusion were also measured. RESULTS: Both bite force and occlusal contact area were lowest at 1 month postoperatively. The values of bite force and occlusal contact area steadily increased thereafter. The bite force and occlusal contact area reached to the preoperative levels at 6 months after operation and slightly above the preoperative level at 12 months after operation. There were no statistically significant differences between 12 months and the control values for bite force measurements (P > .05). CONCLUSION: Although statistically not significant, this study suggests that mandibular symphyseal distraction osteogenesis increases the bite force and occlusal contact area in patients with transverse mandibular deficiency.

Adolescent↗
PubMed2006

Quantitative measurement of hepatitis B virus DNA in different areas of hepatic lobules in patients with chronic hepatitis B.

Liver histology in chronic hepatitis B is marked by inflammatory infiltration involving the peripheral zones. The cause of such cellular infiltration remains unknown. The aim of the present study was to investigate the amounts of intrahepatic hepatitis B virus (HBV) DNA separately in the peripheral and central zones, using laser capture microdissection coupled with real-time quantitative polymerase chain reaction. Fourteen patients with chronic hepatitis B were included in the study. Liver biopsy samples were taken and hepatocytes were microdissected separately from peripheral and central zones. DNA was extracted from hepatocytes in each zone and evaluated the amounts of HBV-DNA. Immunohistochemical study for hepatitis B core antigen (HBcAg) was also performed. The amounts of total intrahepatic HBV-DNA in patients positive for hepatitis Be antigen (HBeAg) were greater than those in HBeAg-negative patients. There was no difference in HBV-DNA between the peripheral and central zones. Immunohistochemistry also showed that HBcAg-positive cells were distributed homogeneously in the hepatic lobules. In patients with peripherally predominant HBV-DNA, the serum alanine aminotransferase (ALT) level was lower than in patients with centrally predominant HBV-DNA. HBV-DNA was distributed homogeneously in the hepatic lobules. In patients with lower amounts of HBV-DNA in the peripheral zone, the serum ALT level tended to be higher than in other patients.

Adult↗
PubMed2006

A Japanese case of eosinophilic esophagitis.

Eosinophilic esophagitis (EE) is a rarely diagnosed condition involving eosinophilic infiltration of the esophageal mucosa. Here we present a case of EE in a 69-year-old Japanese man, who presented with abdominal pain, appetite loss, and a history of bronchial asthma. Laboratory findings included peripheral eosinophilia and an increased serum immunoglobulin E level. Computed tomography showed diffuse severe thickening of the esophageal wall, and a barium esophagogram revealed a small caliber of the middle and lower portion of the esophagus, without normal peristaltic contractions. Endoscopy of the esophagus showed a pale mucosa, with adherent whitish exudates resembling fungal infection, and prominent ring-like contractions. Histologic examination of a biopsy specimen revealed marked eosinophil infiltration into the esophageal mucosa. Endoscopic ultrasonography (EUS) demonstrated marked circumferential thickening of the esophageal submucosal layer, and an esophageal manometry study showed a high percentage of ineffective esophageal peristalsis and high-amplitude esophageal body contractions. EUS findings showed no change even after oral corticosteroid therapy, although the histological findings were improved. This is thought to be the first documented Japanese case of EE. EE should be considered in the differential diagnosis in cases of esophageal motility disturbance, even if the patients do not complain of dysphagia.

Aged↗
PubMed2006

Influence of acid suppressants on gastric emptying: cross-over analysis in healthy volunteers.

BACKGROUND: Gastric emptying plays an important role in gastroesophageal reflux disease. Acid suppressants such as H2 receptor antagonists and/or proton pump inhibitors are often used in patients with gastroesophageal reflux disease. However, it remains controversial whether H2 receptor antagonists and proton pump inhibitors delay or accelerate gastric emptying. Here, the influence of acid suppressants on gastric emptying was evaluated via a cross-over study using the [13C]-labeled acetate breath test. METHODS: Twenty normal male subjects without gastroesophageal reflux disease symptoms were enrolled. Gastric emptying was investigated five times in every subject by the [13C]-labeled acetate breath test with oral administration of the vehicle, domperidone, and three acid suppressants: ranitidine, famotidine and rabeprazole. Gastric emptying was estimated by the values of T(max-calc), T(1/2) and %dose/2 h calculated from the 13CO2 breath excretion curve. RESULTS: Using the T(max-calc) values, rabeprazole, ranitidine and famotidine did not influence gastric emptying time in comparison with vehicle administration. Using the T(1/2) and %dose/2 h values, rabeprazole tended to delay gastric emptying. Domperidone produced a statistically significant acceleration of gastric emptying for all three variables (P < 0.05). CONCLUSION: Oral dosage of the H2 receptor antagonists, ranitidine and famotidine, has no significant effect on gastric emptying. However, rabeprazole may delay gastric emptying more strongly than H2 receptor antagonists.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2006

Kinetics of indocyanine green removal from blood can be used to predict the size of the area removed by radiofrequency ablation of hepatic nodules.

BACKGROUND AND AIM: The size of radiofrequency ablation (RFA) in the liver can be negatively influenced by the surrounding blood flow. The indocyanine green (ICG) test can be used to evaluate the effective blood flow in the liver, and distance from the hilus can affect local blood flow. The aim of this study was to assess whether the ICG test or distance from the hilus could be used to predict the size of the ablated area in liver by RFA treatment of hepatocellular carcinoma (HCC) nodules. METHODS: The RFA measurements of 44 HCC nodules in 39 patients were retrospectively studied. Cases were included if they met the following criteria: (i) no catheter treatment before RFA; (ii) no movement of the RFA device; (iii) strict ablation time; and (iv) only one ablation. In all patients, ICG-R15 testing was done immediately before RFA and the initial therapeutic efficacy was evaluated by dynamic computed tomography scanning 2-5 days after RFA. The correlation between the maximum size of the RFA area and the ICG test results or the distance of the target area from the hilus (site of first portal vein divergence) were analyzed statistically. RESULTS: The ICG-R15 result was significantly correlated with the maximum diameter of the ablated area both in 2 cm-electrode tip length (R2 = 0.35, P = 0.0012), and in 3 cm-tip length (R2 = 0.26, P = 0.0377). Multiple-regression analysis showed that the electrode tip length (P = 0.0010) and ICG-R15 (P = 0.0046) were independent factors that could predict the maximum diameter of the RFA area. CONCLUSION: The results of ICG testing can be used to predict the size of the area that will be ablated at a target liver site before RFA treatment.

Aged↗
PubMed2006

Effects of tamsulosin on resting urethral pressure and arterial blood pressure in anaesthetized female dogs.

The purposes of the present study were to investigate the effects of the alpha1-adrenoceptor antagonists tamsulosin, prazosin and urapidil on resting urethral pressure in anaesthetized female dogs, and to compare the results with their effects on arterial blood pressure. Tamsulosin decreased resting maximal urethral pressure in the urethral pressure profile in a dose-dependent fashion, whereas it had almost no effect on mean arterial blood pressure. Prazosin and urapidil also dose-dependently decreased resting maximal urethral pressure, but these effects were accompanied by decreases in mean arterial blood pressure. Thus, of these three compounds, tamsulosin dose-dependently decreased resting maximal urethral pressure with negligible effect on mean arterial blood pressure in female dogs. These results suggest that tamsulosin will be useful in the treatment of voiding dysfunction associated with bladder outlet obstruction in women, with little hypotensive effect.

Adrenergic alpha-Antagonists↗
PubMed2006

The effect of periodontal surgery on bite force, occlusal contact area and bite pressure.

BACKGROUND: Tooth mobility resulting from the loss of periodontal support or trauma induced by periodontal surgery may change the amount of bite force (BF) and bite pressure (BP) and number of occlusal contact areas (OCAs). The aim of the authors' study was to compare BF, BP and OCA of teeth with periodontal disease before and after periodontal surgery with similar values of healthy teeth. METHODS: The authors performed quantitative analysis of BF, BP and OCA using a pressure measurement film. Ten patients with periodontitis who needed periodontal surgery served as the test group. The authors took measurements of BF, BP, OCA and mobility (using Miller's Mobility Index) just before surgery and at one, four and 12 weeks after surgery. They also measured clinical attachment levels (CAL) before surgery and 12 weeks after surgery. Ten subjects without periodontitis served as the control group. RESULTS: Although BF and OCA increased the first week after periodontal surgery, analysis of variance (ANOVA) showed no statistically significant differences at a 95 percent confidence interval. There were statistically significant differences between first-week mobility and that at four and 12 weeks (P = .001). A factorial ANOVA showed significant interaction between BF and mobility (P < .05). CONCLUSIONS: The authors' findings suggest that changes in BF, BP and OCA were not affected by periodontal surgery. However, mean mobility values and BF are correlated. Further investigations of this measurement method involving larger study populations and a longer follow-up period are needed. CLINICAL IMPLICATIONS: It seems to be helpful to follow occlusal changes after periodontal surgery using a pressure measurement film. It also may be suggested that this measurement method could be used to evaluate the treatment prognosis.

Adult↗
PubMed2006

Right pleural effusion in Fitz-Hugh-Curtis syndrome.

Right pleural effusion was diagnosed in a 36-year-old woman with right upper quadrant pain and fever. Enhanced pelvic computed tomography performed because of irregular genital bleeding revealed the pelvic inflammatory disease. Upon further questioning, the patient confirmed that she had recently undergone therapy for Chlamydia trachomatis infection. Therefore she was given an injection of tetracycline because we suspected Fitz-Hugh-Curtis syndrome (FHCS), a pelvic inflammatory disease characterized by perihepatitis associated with chlamydial infection. A remarkable clinical response to antibiotics was noted. The right upper quadrant pain was due to perihepatitis, and the final diagnosis was FHCS. Right pleural effusion may be caused by inflammation of the diaphragm associated with perihepatitis. Once chlamydial infection reaches the subphrenic liver, conditions in the closed space between the liver and diaphragm due to inflammatory adhesion may be conductive to chlamydial proliferation. The possibility of FHCS should be considered in patients and carefully distinguished from other abdominal diseases.

Adult↗
PubMed2006

The effect of periodontitis on biting abilities.

BACKGROUND: The aim of this study was to compare the biting abilities (bite force [BF] and occlusal contact area [OCA]) of chronic periodontitis patients with those of control patients with healthy periodontia by using pressure-sensitive sheets. METHODS: The study population consisted of 20 patients with chronic periodontitis whose initial periodontal therapy was completed and 20 control subjects with healthy periodontia. Periodontitis was diagnosed by radiographs and measurements of probing depth and clinical attachment level. Pressure-sensitive sheets were used for the quantitative analysis of BF and OCA. RESULTS: Both mean BF and OCA values were greater in the healthy control group compared to those of the study group. The differences between the groups were statistically significant at the 95% confidence level. CONCLUSION: Reduced periodontal support in the absence of inflammation negatively affected biting abilities.

Adult↗
PubMed2006

Effects of different sizes of beta-tricalcium phosphate particles on bone augmentation within a titanium cap in rabbit calvarium.

This study evaluated the effects of different sizes of beta-TCP particles on bone augmentation within a titanium cap. In 20 rabbits, the calvarium was exposed and a circular groove was prepared. After marrow penetration, a standardized hemispherical titanium cap was placed in the circular grove. The cap was filled with small-sized (100-250 microm) or medium-sized (250-500 microm) beta-TCP particles for the experimental site and without beta-TCP for the control site. After one and three months of healing, the animals were euthanized and examined histologically. There was a statistically significant difference in the amount of mineralized bone generated between the experimental and control groups in the three-month specimens. Furthermore, the medium-sized particles showed significantly more mineralized bone than did the small-sized particles. Based on these findings, we suggested that beta-TCP might be effective for bone formation and that medium-sized particles are more useful than small-sized particles in bone maturation.

Animals↗
PubMed2006

Treatment of Miller Class III recessions with enamel matrix derivative (Emdogain) in combination with subepithelial connective tissue grafting.

This report examines the clinical parameters and radiographic characteristics of two patients with Class III gingival recession who were treated with combined connective tissue grafting and root coverage with enamel matrix derivative. Both patients presented with multiple Class III recessions in the mandibular central incisors. Root coverage was achieved by connective tissue grafting in conjunction with the application of enamel matrix derivative. Soft tissue coverage of the root surfaces was achieved clinically, and radiographs showed improvement in the interproximal vertical bone defects.

Adult↗