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Biomedical subjects

H Sano

Publications and source records attributed to H Sano.

At least 109 records · Page 6Linked to original sources

Role of T cells in development of chronic pancreatitis in male Wistar Bonn/Kobori rats: effects of tacrolimus.

We assessed T cell association with acinar cell apoptosis and a preventive effect of tacrolimus, a T cell suppressant, on the development of chronic pancreatitis in male Wistar Bonn/Kobori rats. At 15 wk, cellular infiltrates composed of F4/80-positive cells (monocytes/macrophages), CD4-positive cells, and CD8-positive cells were extensive in the interlobular connective tissue and parenchyma. In particular, CD8-positive cells invaded pancreatic lobules and formed close associations with acinar cells, some of which demonstrated features of apoptosis. At 20 wk, CD8-positive cells were still abundant in the fibrotic tissue formed with loss of acinar cells. Repeated subcutaneous injection of 0.1 mg x kg(-1) x day(-1) but not 0.025 mg x kg(-1) x day(-1) of tacrolimus for 10 wk completely prevented the occurrence of acinar cell apoptosis, infiltration of CD4- and CD8-positive cells, and development of pancreatitis at the age of 20 wk, but these maneuvers did not recover the decreased plasma corticosterone levels, which may be responsible for the development of disease. We demonstrated that T cells, possibly CD8-positive cells, are involved in inducing apoptosis of acinar cells, raising the possibility that tacrolimus might find clinical application in the treatment of autoimmune chronic pancreatitis.

Animals↗

Regulation of eosinophil function by phosphatidylinositol-specific PLC and cytosolic PLA(2).

We examined the regulatory role of cytosolic phospholipase A(2) (cPLA(2)) and phosphatidylinositol (PI)-specific phospholipase C (PLC) in the degranulation of human eosinophils and leukotriene (LT) C(4) synthesis. Activation with formyl-Met-Leu-Phe + cytochalasin B (fMLP/B) caused a time-dependent release of eosinophil peroxidase (EPO) and LTC(4), which was inhibited by pertussis toxin. By immunoblotting, eosinophil PLC-beta2 and -gamma2 isoforms were identified, and PLC activation was measured as a function of inositol 1,4,5-trisphosphate concentration. Stimulated release of EPO and intracellular Ca(2+) concentration was inhibited by ET-18-OCH(3), a PI-PLC inhibitor, whereas trifluoromethylketone (TFMK), a cPLA(2) blocker, had no inhibitory effect. Both TFMK and ET-18-OCH(3) attenuated stimulated arachidonate release and LTC(4) secretion, suggesting that activation of both PLC and cPLA(2) is essential for LTC(4) synthesis caused by fMLP/B. The structurally unrelated protein kinase C inhibitors bisindolylmaleimide, Ro-31-8220, and Go-6976 all blocked fMLP/B-induced EPO release but not LTC(4) secretion. 1,2-bis(2-Aminophenoxy)ethane-N,N,N',N'- tetraacetic acid acetoxymethyl ester, an intracellular Ca(2+) chelator, suppressed both EPO release and LTC(4) secretion. We found that fMLP/B-induced LTC(4) secretion from human eosinophils is regulated by PI-PLC through calcium-mediated activation of cPLA(2). However, cPLA(2) does not regulate eosinophil degranulation.

Arachidonic Acid↗

Successful extracorporeal shock wave lithotripsy for sibling pancreatic duct stones.

We present a case of 2 brothers with idiopathic chronic pancreatitis associated with pancreatic duct stones which could be successfully disintegrated by extracorporeal shock wave lithotripsy (ESWL). An obvious etiology for the pancreatolithiasis, like alcohol or biliary disease, was lacking and point mutations of the cationic trypsinogen gene exons 2 and 3 were not detected in the long arm of the 7th chromosome. However, a hereditary etiology could not be precluded since pancreatolithiasis occurred in the siblings. There has been no recurrence of pancreatic stones during 42 months of follow-up periods, for both. ESWL, the least invasive therapy, appeared applicable and effective for pancreatolithiasis in the present cases.

Adult↗

The glass-ionomer phase in resin-based restorative materials.

Glass-ionomer (GI) fillers are added to restorative materials, but it is unclear if they truly react with these materials. This TEM study evaluated the existence of the GI phase in a conventional GIC (ChemFlex), a resin-modified GIC (Fuji II LC), a giomer (Reactmer Paste), a compomer (Dyract AP), and a composite (SpectrumTPH), before and after water uptake. Wafers were stored at 100% RH for 24 hrs, or in water for 7 or 84 days. ChemFlex glass particles were surrounded by 300-nm-thick silica gel layers. In Fuji II LC, we found thinner hydrogel layers (100 nm) that became thicker upon water storage. No appreciable change occurred in Reactmer Paste. Only a very thin hydrogel layer occurred in Dyract AP, and none was seen in SpectrumTPH after water storage for 84 days. We conclude that the variable extent of the GI phase is determined by differences in the resin composition of the restoratives.

Biocompatible Materials↗

Urocortin expression in synovium of patients with rheumatoid arthritis and osteoarthritis: relation to inflammatory activity.

Peripherally produced CRH acts as a local auto/paracrine proinflammatory agent. Urocortin is a new member of the CRH family that acts through the family of CRH receptors. In this study, we demonstrated that the expression of urocortin mRNA in synovia of patients with rheumatoid arthritis was greater than that of patients with osteoarthritis. Also, we detected urocortin and CRH receptor immunoreactivity in the synovial lining cell layer, subsynovial stromal cells, blood vessel endothelial cells, and mononuclear inflammatory cells from the joints of rheumatoid arthritis and osteoarthritis patients. The expression of immunoreactive urocortin was significantly greater in rheumatoid arthritis than osteoarthritis (P < 0.0001) and correlated with the extent of inflammatory infiltrate. CRH receptor immunoreactivity was strong in mononuclear inflammatory cells of rheumatoid arthritis synovia. Urocortin stimulated IL-1beta and IL-6 secretion by human peripheral blood mononuclear cells in vitro. These findings suggest that, like CRH, urocortin is present in peripheral inflammatory sites, such as rheumatoid synovium, and acts as an immune-inflammatory mediator.

Aged↗

Identity of Cypripedium calceolus (Orchidaceae) in Rebun Island: comparative DNA analysis of related species.

Cypripedium calceolus was found in 1980 in Rebun Island off the north coast of Hokkaido, Japan, but the origin of this plant has been a controversial issue. In this study, we have made a comparative study by chloroplast DNA sequencing analysis among C. calceolus which occurs in Rebun Island and populations of C. calceolus from western Europe, China and far eastern Russia (Nakhodka), and also as references, C. macranthos in Japan and other Cypripedium species in North America. A Cypripedium cf. "calceolus", found recently in eastern Hokkaido, was also included in this analysis. The C. calceolus samples analyzed were categorized into three groups, i.e., those from Western Europe, from China and far eastern Russia, and from Rebun Island. The C. calceolus in Rebun Island was clearly different from the others in terms of DNA sequence and morphological features. The C. cf. calceolus from eastern Hokkaido and one sample from Nadhodka, Russia, were also classified into the same group as those from Rebun Island, although some differences in their morphological features were observed. It is concluded that the C. calceolus found in Rebun Island is not identical with those growing in Europe and China. In addition, it was found that it may be possible to classify C. macranthos into two groups, namely groups which include or do not include var. rebunense. An unidentified Cypripedium species found in Rebun Island falls into the same group as var. rebunense.

Base Sequence↗

Comparison of the activity of four chitosan derivatives in reducing initial adherence of oral bacteria onto tooth surfaces.

We examined the effects of four kinds of chitosan derivatives on initial adherence of oral bacteria onto human anterior teeth surfaces. The buccal surfaces of anterior teeth were used as the experimental surfaces. They were divided into five rectangle areas with outer dimensions of about 2 mm x 4 mm. After applying two ml of a sample solution onto the tooth surfaces, an examiner wiped each rectangle area with a sterilized plastic swab one, three and six hours later. Then we measured bacterial counts in sterilized swabs with mitis salivarius agar. We found that the order of magnitude of the inhibitory effect on the adherence of oral bacteria was low molecular chitosan > phosphorylated chitosan > amorphous chitosan > carboxymethyl chitosan. The solution containing 0.5% low molecular chitosan depressed the bacterial adherence to the same extent as a 50 ppm chlorhexidine digluconate solution for three hours, and 0.1% phosphorylated chitosan also exhibited an inhibitory effect in bacterial adherence for one hour. Amorphous chitosan had a moderate inhibitory effect, but no clear inhibitory activity was found with 0.1% carboxymethyl chitosan. These results suggest that low molecular chitosan and phosphorylated chitosan have the potential to effectively inhibit the initial adherence of oral bacteria onto human tooth surfaces.

Adult↗

Effect of rinsing with phosphorylated chitosan on four-day plaque regrowth.

This clinical investigation examined the effect of phosphorylated chitosan rinsing on plaque development and on the buffering capacity of plaque suspension. Three male adult subjects participated in the trial that was designed as a single blind study. Participants refrained from mechanical oral hygiene procedures during a four-day study and rinsed three times a day with 20 ml of test solutions. A wash-out period of three days was instituted between the placebo and phosphorylated chitosan rinsing period. Clinical evaluation and plaque sampling were performed at the end of each test period. We disclosed plaque accumulations on the buccal upper front teeth with a two-tone disclosing agent to distinguish between newly formed plaque and old plaque. After taking color slides, we then used a computerized image analysis. Tooth areas covered by plaque on the color slides were digitized and expressed as percentages of the tooth area. The buffering capacity of the collected plaque fluid was determined by using a beta-titrator. A mouth rinse containing 0.5% phosphorylated chitosan significantly reduced both newly formed plaque areas (red disclosed; p < 0.001) and old plaque areas (blue disclosed; p < 0.01) compared to a placebo rinsing. However there was no significant difference in the plaque buffering capacity (p > 0.05) between the mouth rinse containing 0.5% phosphorylated chitosan and placebo. These findings might suggest that mouth rinse containing phosphorylated chitosan would be effective in reducing plaque formation and have a slight ability to enhance plaque buffering capacity.

Adult↗

Novel macrolactins as antibiotic lactones from a marine bacterium.

Seven new macrolactins (named G~M) and known macrolactins A and F were isolated from a culture broth of Bacillus sp. PP19-H3. The strain had been isolated from the macroalga, Schizymenia dubyi. Macrolactin A, which was 24-membered lactone, had previously been reported to show antibacterial, cytotoxic and antiviral activities. The new macrolactins include 22-membered ring or dicyclic lactone in addition to geometric isomers of known macrolactins A and F. The antibacterial activities of all the macrolactins examined in this study were relatively weak.

Anti-Bacterial Agents↗

Expression of basic helix-loop-helix proteins in the glomeruli.

BACKGROUND: Basic helix loop helix (bHLH) proteins play a critical role in the differentiation of not only striated muscle cells but also adipocytes, neuron cells and smooth muscle cells. Previous studies have established in vitro mouse mesangial cells (MCs) to maintain the differentiated smooth muscle phenotype. MATERIALS AND METHODS: The purpose of the present study was to clone bHLH proteins from these MCs using the primers designed from a homologous sequence specific to bHLH, and to analyze the presence of bHLH proteins in normal kidney in vivo. From the cloning of MCs in vitro, we identified myf5 and herculin mRNA but not myoD. The expression of bHLH proteins in vivo was examined by immunohistochemistry with each specific antibody. RESULTS: The MCs in newborn mice possessed Id but did not express either protein herculin or myoD. On the other hand, mature MCs expressed both myf5 and herculin. The Id protein disappeared in mature glomeruli. CONCLUSION: These results suggest that bHLH proteins are an important factor for mature MCs in vivo.

Aging↗

[Lung cancer metastasis to the gingiva].

A 70-year-old man was referred to our hospital complaining of left gingival tumors with bleeding, halitosis and impediments to eating and speaking. Tumors were also found in both lungs, the stomach, the intestines and the right adrenal gland. Biopsies of the gingiva and the stomach pointed to undifferentiated carcinoma. Although the patient was treated with carboplatin plus 5-fluorouracil, the gingival tumors did not change in size. Subsequently, the gingival tumors were irradiated with a total dose of 39 Gy, and disappeared completely. The patient died 78 days later of hemorrhage of the digestive tract. Postmortem examination revealed that the primary tumor was in the left lung. Nineteen cases of lung cancer metastatic to the gingiva have been reported. The prognosis in all was very poor, and the QOL was compromised. However, several cases have improved with therapy to the gingiva. We believe that initial therapy should be directed at metastatic gingival tumors of the lung.

Adenocarcinoma↗

Expression of cyclooxygenase-2 in patients with bladder carcinoma.

PURPOSE: Cyclooxygenase-2 is considered to have an important role in the development of metastasis in cancer due to angiogenesis function. The expression of cyclooxygenase-2 was found to be up-regulated in colorectal carcinoma and other cancers. We investigated cyclooxygenase-1 and 2 expressions in patients with bladder cancer, chronic cystitis and normal bladder. MATERIALS AND METHODS: A total of 118 specimens were obtained from patients treated at Osaka City University Hospital for bladder cancer, including 10 with chronic cystitis and 8 with normal bladder tissue. Immunohistochemistry, with affinity purified antibodies against human cyclooxygenase-1 and 2 that did not have cross-reactivity with each other, and reverse transcriptase polymerase chain reaction to study the messenger RNA expression were performed. RESULTS: Although no marked expression of cyclooxygenase-2 was observed in the normal bladder, it was slightly seen in infiltrative inflammatory cells of chronic cystitis, and a higher expression was found in cancer cells. The extent and intensity of immunoreactive cyclooxygenase-2 polypeptides in cancer cells was statistically much greater than those in cells from normal bladder tissue. Moreover, correlation between cyclooxygenase-2 expression and tissue type or progression of bladder cancer was observed. Cyclooxygenase-2 expression was higher in grade 3 bladder cancer than in grade 1, and was higher in advanced than in early stage cancer. CONCLUSIONS: These results demonstrate that generated cyclooxygenase-2 in the cells of patients with bladder cancer might be significant in the proliferation of bladder malignant cells and development of invasions.

Adult↗

Relationship between bond strengths and nanoleakage: evaluation of a new assessment method.

PURPOSE: To test if there was a correlation between resin-dentin bond strengths and nanoleakage of total etch and self-etching primer bonding systems. MATERIALS AND METHODS: Ten extracted third molars were ground flat with 600 grit SIC paper under running water to expose middle dentin. Clearfil Liner Bond 2V or Single Bond was applied to the dentin surface according to the manufacturers' instructions. A crown was built-up with Clearfil AP-X resin-based composite, and the specimens stored in water for 24 hrs at 37 degrees C. The bonded assemblies were cut mesiodistally perpendicular to the interface into approximately 0.7 mm thick slabs, and trimmed for microtensile bond strength testing. Alternate slices from each tooth were either entirely double-coated with nail varnish leaving a 0.5 mm window around the interface, or left uncoated to be immersed in water for 13 hrs as the control. The varnished (experimental) slabs were immersed in 50% AgNO3 for 1 hr, and then immersed in a photo developing solution for 12 hrs. All specimens were subjected to microtensile bond test at a crosshead speed of 1 mm/min. After debonding, the specimens were embedded in epoxy resin and observed under a confocal laser scanning microscope for determination of lateral silver penetration within the interface. Silver penetration was further analyzed under the SEM. Data were analyzed with one- and two-way ANOVA, Fisher's PLSD test (P < 0.05), and regression analysis. RESULTS: The bond strengths of Clearfil Liner Bond 2V and Single Bond were not significantly different (P > 0.05); however the bond strengths of the specimens that were soaked in 50% AgNO3 for 1 hr significantly increased (P < 0.01). No correlation was observed between bond strengths and nanoleakage.

Acid Etching, Dental↗

Microtensile bond strength of two single-step adhesive systems to bur-prepared dentin.

PURPOSE: To compare the microtensile bond strength (MTBS) of two single-step adhesive systems to two types of bur-prepared dentin. MATERIALS AND METHODS: Using either of two adhesives, the experimental MZ-2000 (MZ) and the commercial One-Up Bond F (OUB), resin composite was bonded to flat buccal and root dentin surfaces of eight extracted human premolars. These surfaces were produced by grinding with either regular-grit or superfine-grit diamond burs in a high-speed handpiece. After storage overnight in 37 degrees C water, the bonded specimens were sectioned into ten slices approximately 0.7 mm thick, perpendicular to the bonded surface. They were then subjected to microtensile testing. The surfaces of the fractured specimens were observed both visually and microscopically to determine the failure mode. In addition, to observe the effect of conditioning, the two types of bur-ground dentin surfaces were conditioned with the adhesives, rinsed with acetone, and observed under SEM. RESULTS: When MZ was bonded to dentin prepared with a regular-grit diamond bur, MTBS was the lowest and failures occurred adhesively at the interface, whereas other groups revealed primarily mixed failures. MZ-conditioned dentin surfaces ground with a regular-grit diamond bur were covered with a residual smear layer. However, the smear layers on the surface of MZ-conditioned dentin ground with a superfine-grit diamond bur and on OUB-conditioned dentin prepared either with a regular-grit or superfine-grit diamond bur were mostly or partially dissolved. CONCLUSION: Some of the single-step adhesive systems may produce low bond strengths to smear layers created by regular-grit diamond burs.

Acetone↗

Resin-tooth adhesive interfaces after long-term function.

PURPOSE: To characterize with scanning electron microscopy (SEM), the morphology of adhesive interfaces that had been functioning in an oral cavity for several years. MATERIALS AND METHODS: Cavities were prepared in vivo in caries-affected primary molars under local anesthesia. After removal of the entire carious lesion, the cavity was restored with a dentin adhesive system (Scotchbond Multi-Purpose). After several yrs, as the successor permanent teeth erupted, the resin-filled teeth were extracted. Then, the extracted resin-restored primary molars were cross-sectioned perpendicular to the adhesive interface using a low speed diamond saw and then polished for SEM examination. RESULTS: Morphological changes, such as digestion of the collagen fibrils and deterioration of the bonding resin and hybrid layer, were observed at the interface of the oral environment specimens. The results of this study demonstrated that degradation of resin-dentin bond structures appeared to occur in the human oral environment over time.

Child↗