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T Itoh

Publications and source records attributed to T Itoh.

At least 505 records · Page 28Linked to original sources
PubMed1997

Periodontal parameters of osseointegrated dental implants. A 4-year controlled follow-up study.

The aim of this study was to evaluate the periodontal parameters of osseointegrated dental implants. The condition of the peri-implant mucosa was assessed using periodontal parameters, i.e., of plaque index, bleeding on probing, probing pocket depth, probing attachment level and Periotest scores as well as a radiographic parameter, over a 4-year follow-up period. 32 non-submerged ITI dental implants, all placed in the mandible, were studied in 12 patients who had good oral hygiene. All patients were regularly recalled at 6-month intervals. The overall implant success rate was 100%. None of the implants showed any signs of inflammation, radiographic bone loss or any detectable mobility during the follow-up period. Methods similar to those used to evaluate the natural dentition were effectively employed to assess the clinical status of the dental implants. The diagnostic value of these parameters could not, however, be determined from this study due to the absence of any peri-implant tissue complications. The results indicated that some periodontal parameters of healthy peri-implant mucosa might be slightly different from healthy periodontal tissue.

Alveolar Process↗
PubMed1997

Possible mechanisms underlying the midazolam-induced relaxation of the noradrenaline-contraction in rabbit mesenteric resistance artery.

1. The mechanisms underlying the midazolam-induced relaxation of the noradrenaline (NA)-contraction were studied by measuring membrane potential, isometric force and intracellular concentration of Ca2+ ([Ca2+]i) in endothelium-denuded muscle strips from the rabbit mesenteric resistance artery. The actions of midazolam were compared with those of nicardipine, an L-type Ca2+-channel blocker. 2. Midazolam (30 and 100 microM) did not modify either the resting membrane potential or the membrane depolarization induced by 10 microM NA. 3. NA (10 microM) produced a phasic, followed by a tonic increase in both [Ca2+]i and force. Midazolam (10-100 microM) did not modify the resting [Ca2+]i, but attenuated the NA-induced phasic and tonic increases in [Ca2+]i and force, in a concentration-dependent manner. In contrast, nicardipine (0.3 microM) attenuated the NA-induced tonic, but not phasic, increases in [Ca2+]i and force. 4. In Ca2+-free solution containing 2 mM EGTA, NA (10 microM) transiently increased [Ca2+]i and force. Midazolam (10-100 microM), but not nicardipine (0.3 microM), attenuated this NA-induced increase in [Ca2+]i and force, in a concentration-dependent manner. However, midazolam (10 and 30 microM), had no effect on the increases in [Ca2+]i and force induced by 10 mM caffeine. 5. In ryanodine-treated strips, which have functionally lost the NA-sensitive Ca2+ storage sites, NA slowly increased [Ca2+]i and force. Nicardipine (0.3 microM) did not modify the resting [Ca2+]i but partly attenuated the NA-induced increases in [Ca2+]i and force. In the presence of nicardipine, midazolam (100 microM) lowered the resting [Ca2+]i and further attenuated the remaining NA-induced increases in [Ca2+]i and force. 6. The [Ca2+]i-force relationship was obtained in ryanodine-treated strips by the application of ascending concentrations of Ca2+ (0.16-2.6 mM) in Ca2+-free solution containing 100 mM K+. NA (10 microM) shifted the [Ca2+]i-force relationship to the left and enhanced the maximum Ca2+-induced force. Under these conditions, whether in the presence or absence of 10 microM NA, midazolam (10 and 30 microM) attenuated the increases in [Ca2+]i and force induced by Ca2+ without changing the [Ca2+]i-force relationship. 7. It was concluded that, in smooth muscle of the rabbit mesenteric resistance artery, midazolam inhibits the NA-induced contraction through its inhibitory action on NA-induced Ca2+ mobilization. Midazolam attenuates NA-induced Ca2+ influx via its inhibition of both nicardipine-sensitive and -insensitive pathways. Furthermore, midazolam attenuates the NA-induced release of Ca2+ from the storage sites. This effect contributes to the midazolam-induced inhibition of the NA-induced phasic contraction.

Animals↗
PubMed1997

Role of endothelium in regulation of smooth muscle membrane potential and tone in the rabbit middle cerebral artery.

1. The characteristic features of the endothelium-mediated regulation of the electrical and mechanical activity of the smooth muscle cells of cerebral arteries were studied by measuring membrane potential and isometric force in endothelium-intact and -denuded strips taken from the rabbit middle cerebral artery (MCA). 2. In endothelium-intact strips, histamine (His, 3-10 microM) and high K+ (20-80 mM) concentration-dependently produced a transient contraction followed by a sustained contraction. Noradrenaline (10 microM), 5-hydroxytryptamine (10 microM) and 9,11-epithio-11, 12-methano-thromboxane A2 (10 nM) each produced only a small contraction (less than 5% of the maximum K+-induced contraction). 3. N(G)-nitro-L-arginine (L-NOARG, 100 microM), but not indomethacin (10 microM), greatly enhanced the phasic and the tonic contractions induced by His (1-10 microM) in endothelium-intact, but not in endothelium-denuded strips, suggesting that spontaneous or basal release of nitric oxide (NO) from endothelial cells potently attenuates the His-induced contractions. Acetylcholine (ACh, 0.3-3 microM) caused concentration-dependent relaxation (maximum relaxation by 89.7 +/- 7.5%, n=4, P<0.05) when applied to endothelium-intact strips precontracted with His. L-NOARG had little effect on this ACh-induced relaxation (n=4; P<0.05). Apamin (0.1 microM), but not glibenclamide (3 microM), abolished the relaxation induced by ACh (0.3-3 microM) in L-NOARG-treated strips (n=4, P<0.05). 4. In endothelium-intact tissues, His (3 microM) depolarized the smooth muscle membrane potential (by 4.4 +/- 1.8 mV, n = 12, P < 0.05) whereas ACh (3 microM) caused membrane hyperpolarization (-20.9 +/- 3.0 mV, n = 25, P< 0.05). The ACh-induced membrane hypepolarization persisted after application of L-NOARG (-23.5 +/- 5.9 mV, n=8, P<0.05) or glibenclamide (-20.6 +/- 5.4 mV, n=5, P<0.05) but was greatly diminished by apamin (reduced to - 5.8 +/- 3.2 mV, n = 3, P< 0.05). 5. Sodium nitroprusside (0.1-10 microM) did not hyperpolarize the smooth muscle cell membrane potential (0.2 +/- 0.3 mV, n=4, P>0.05) but it greatly attenuated the His-induced contraction in endothelium-denuded strips (n-4, P<0.05). 6. These results suggest that, under the present experimental conditions: (i) spontaneous or basal release of NO from endothelial cells exerts a significant negative effect on agonist-induced contractions in rabbit MCA, and (ii) ACh primarily activates the release of endothelium-derived hyperpolarizing factor (EDHF) in rabbit MCA.

Animals↗
PubMed1997

Contamination of microbial foreign bodies in bottled mineral water in Tokyo, Japan.

A total of 292 imported and domestic bottled mineral waters (90 brands) obtained from consumers and retailers were examined, by eye, for observable microbial foreign bodies. Fungal and bacterial foreign contaminants were found in 45 samples of water (20 brands) and in 14 samples of water (10 brands), respectively. Of the samples of water found to be contaminated, 41 (22 brands) were imported and 18 (8 brands) were produced domestically. Of 22 brands that were contaminated, 20 (91%) had been sterilized by at least one method. Forty-eight (98%) of 49 samples confirmed with foreign bodies were less than 1 year old. Among the moulds isolated the most predominant genus was Penicillium, followed by Acremonium and Cladosporium. The samples that contained fungi were less contaminated by bacteria than those that contained observable bacterial foreign bodies.

Bacteria↗
PubMed1997

An updated report of a case of lung cancer resected using cardiopulmonary bypass.

Although surgical intervention for advanced lung cancer invading the aortic wall is challenging, we successfully carried out such radical surgery under cardiopulmonary bypass as previously reported in this journal. One patient has now been followed for more than 5 years after the operation, so that we conclude if there is no evidence of metastatic cancer in selected patients then complete resection should be attempted using circulatory support, with the hope of an occasional cure.

Aorta, Thoracic↗
PubMed1997

Substances in the aqueous fraction of cigarette smoke inhibit lipid peroxidation in synaptosomes of rat cerebral cortex.

The effects of water-soluble substances in cigarette smoke on lipid peroxidation were investigated using nerve terminals prepared from the rat cerebral cortex. The prepared smoke-substances significantly reduced the spontaneous increase in thiobarbituric acid-reactive substances in synaptosomes in a dilution factor-dependent manner. Furthermore, the aqueous extract also inhibited the elevation of lipid peroxidation induced by 2,2'-azobis (2-amidinopropane) dihydrochloride, a peroxyl radical generator. Smoke-substances scavenged superoxide radicals generated from stimulated human leukocytes and from the xanthine/xanthine oxidase system. These effects were not mimicked by nicotine. The antioxidant effects of smoke-substances were preserved for several days at 5 degrees or -80 degrees C. The results suggest that the smoke-substances may possess long half-lives and scavenge the radicals which cause lipid-peroxidation in synaptosome membranes.

Animals↗
PubMed1997

Effects of daily alcohol intake on the blood pressure differ depending on an individual's sensitivity to alcohol: oriental flushing as a sign to stop drinking for health reasons.

OBJECTIVE: To determine whether flushing of the facial skin in response to alcohol consumption (alcohol flushing) is a warning sign of hypertension. We also sought the relationship between alcohol flushing and other risk factors that may contribute to the development of hypertension. METHODS: We first investigated the relationship of the aldehyde dehydrogenase 2 (ALDH2) genotype to alcohol flushing for 53 normal volunteers. We evaluated the relationships among hypertension, alcohol consumption, and facial flushing for 1011 middle-aged Japanese men (aged 40-68 years; mean 51.6 +/- 5.5 years), on the basis of their responses to questionnaires and health records. RESULTS: The first examination of 53 normal volunteers showed that there were differences in the degree of alcohol flushing between the ALDH2 genotypes (P < 0.01). Hypertension was observed in 27.4% of the study population (277 of 1011), and was correlated positively to alcohol consumption (P < 0.01). The prevalence of hypertension differed significantly among these four groups: there was a 22.4% prevalence (70 of 312) among subjects with no flushing, a 33.8% prevalence (113 of 334) among those with slight flushing, a 27% prevalence (84 of 311) among those with visible flushing, and an 18.5% prevalence (10 of 54) among subjects who were almost completely intolerant to alcohol (P < 0.05). In particular, heavy drinkers who consumed > or = 1.5 Go (a traditional Japanese unit equivalent to 27 g ethanol) a day had a high prevalence of hypertension with slight and visible skin flushing [42% (63 of 150) and 40.7% (24 of 59), respectively]. That a family history of hypertension, greater age, heavy alcohol consumption, obesity, and symptoms of intoxication including flushing were correlated significantly to the prevalence of hypertension for all groups was demonstrated by multiple logistic regression analysis (P < 0.05). CONCLUSIONS: A repeated heavy alcohol intake could increase the risk of hypertension for Japanese subjects who exhibit skin flushing in response to alcohol consumption. Chronic alcohol intake by subjects with alcohol flushing might bring about a significant increase in blood acetaldehyde levels and cause an additional rise in the blood pressure.

Adult↗
PubMed1997

Cystic pulmonary metastases of endometrial stromal sarcoma of the uterus, mimicking lymphangiomyomatosis: a case report with immunohistochemistry of HMB45.

A case of endometrial stromal sarcoma (ESS) showed cystic pulmonary metastases mimicking lymphangiomyomatosis (LAM). A 58-year-old female, who had undergone total hysterectomy for low-grade ESS 16 years previously, had repeated bouts of pneumothorax. Multiple thin-walled cysts in the peripheral lung were revealed by radiological examinations. In an open-lung biopsy specimen, cystic lesions were surrounded by layers of spindle-shaped cells of varying thickness that resembled LAM. However, in addition to subtle histologic differences from LAM, HMB45 (antimelanoma antibody) showed positive in LAM (n = 3), but was negative in ESS (n = 2) and the cystic lesions of this case. Using myogenic markers (desmin and alpha-smooth muscle actin), metastatic ESS could be immunohistochemically differentiated from mesenchymal cystic hamartoma (n = 1). HMB45 immunohistochemistry is useful in the differential diagnosis of cystic pulmonary lesions.

Actins↗
PubMed1997

Acquired pure red cell aplasia in Japan.

We reviewed the clinical features of 150 patients with acquired pure red cell aplasia (PRCA) in Japan. There were 35 patients with acute type and 115 with chronic type PRCA. Of the acute PRCA patients, 17 had human parvovirus B19 infection. Drug-induced PRCA was demonstrated in 7 patients. Of the 115 patients with chronic PRCA, 51 patients were classified as primary and 64 cases were associated with miscellaneous diseases such as thymoma, a variety of hematological disorders and collagen diseases. Among the hematological disorders, PRCA was most frequently seen in granular lymphocyte proliferative disorders (GLPD). The erythroid colony growth patterns from bone marrow were variable. The serum erythropoietin level was high in most patients. Various kinds of treatment were tried for the chronic PRCA cases. Cyclosporin A (CyA) was the most effective form of treatment and the response rate was 82% (31/38). Twenty-three of 37 patients (62%) responded to bolus methylprednisolone therapy. The largest number of patients were treated with oral prednisolone, and the therapy was effective in 27 of the 55 (49%). The response rate to cyclophosphamide was only 29% (5/17), but in combination with prednisolone, half of the patients (7/14) responded to the therapy. CyA is recommended as the first-line therapy for acquired chronic PRCA.

Adolescent↗
PubMed1997

Intratumoral heterogeneity in prostate cancer demonstrated by volume-weighted mean nuclear volume.

This study was conducted to investigate the degree of heterogeneity of the volume-weighted mean nuclear volume (MNV) calculated from radical prostatectomy specimens, and to evaluate how closely the MNV calculated from transrectal biopsy specimens reflected the overall malignancy. MNV was evaluated using 77 sections of histological specimens from 9 patients who underwent radical prostatectomy at Shizuoka City Hospital between January 1990 and December 1995. The MNV values calculated from radical prostatectomy specimens were compared with those calculated from preoperative transrectal biopsy specimens. MNV was judged to be homogeneous in six cases and heterogeneous in three cases. Of the heterogeneous cases, MNV calculated from the transrectal biopsy specimens was judged to be underestimated in 2 of 3 cases. This study shows that intratumoral heterogeneity of prostate cancer may affect clinical estimates of the grade of malignancy based on the MNV, and indicates the need for a sufficient number of specimens in order to evaluate the MNV by transrectal biopsy.

Adenocarcinoma↗
PubMed1997

Effect of plaunotol on gastric injury induced by ischaemia-reperfusion in rats.

Plaunatol, an anti-ulcer drug, increases prostaglandin content in gastric tissue but its effect on radical-mediated gastric damage or activity against reactive oxygen species is unknown. We examined the effects of oral administration of plaunotol (Kelnac) on the acute gastric mucosal lesion and its progression to ulcer lesion induced by ischaemia-reperfusion in rats. Plaunotol (30 and 100 mg kg-1, 15 min before ischaemia) significantly reduced the total erosion area observed immediately after ischaemia-reperfusion. When plaunotol (30 and 100 mg kg-1, once a day) was administrated orally 60 min after reperfusion, it prevented the progression from erosion to ulcer. At 72 h after ischaemia-reperfusion, the total area of ulcers lesions was significantly reduced compared with that without plaunotol administration. Furthermore, treatment with plaunotol (100 mg kg-1) significantly increased prostaglandin E2 content in gastric tissues of both acute gastric mucosal lesion and gastric ulcer lesion. In in-vitro experiments, plaunotol (1-3 mg mL-1) reduced the superoxide radicals generated by leucocytes, but not by xanthine oxidase. These results indicate that plaunotol has protective effects on both the onset of acute gastric mucosal injury and its progression to ulcer lesion induced by ischaemia-reperfusion. Both effects of plaunotol on increase in prostaglandin content in gastric tissues and inhibition of superoxide radical from leucocytes may play important roles on the protection against gastric mucosal injury.

Animals↗
PubMed1997

[Evaluation of a latex agglutination method for detecting and characterizing verotoxin (VT) produced by Escherichia coli].

The detection of VT produced by Escherichia coli is very important for the identification of verotoxin-producing Escherichia coli (VTEC). The latex agglutination reagents (Denka Seiken Co. Ltd, Tokyo) which was developed to detect VT was compared with the vero cell bioassay or polymerase chain reaction method. A total 147 VT-positive strains (109 serotype O157:H 7/- and 38 non-O157 serotype) and 31 VT-negative strains which were isolated from human were investigated. In addition, a total of 79 VT-positive strains (14 serotype O157:H7/- and 65 non-O157 serotype) and 79 VT-negative strains which were isolated from animals were also examined. The latex agglutination assay for the human isolates showed the 100% sensitivity, specificity and agreement. The assay for the animal isolates showed 94.9% sensitivity, 100% specificity and 97.5% agreement. Although 4 of 8 strains isolated from swine which produce VT2 variant toxin (VT2e) failed in detecting verotoxin by latex agglutination assay, VT2e was not related to human infections. We conclude that this latex agglutination reagent is highly sensitive and specific for detecting and characterizing VT of E. coli. The method is reliable, easy to perform at any laboratories.

Animals↗
PubMed1997

[Biochemical and molecular characterization of Salmonella serovar enteritidis phage type 4 isolated from food poisoning outbreaks in Tokyo].

Since 1989, outbreaks of Salmonella ser. Enteritidis (S. Enteritidis) food poisoning have dramatically increased in Tokyo, and a total of 31 outbreaks has been reported in 1989. Twenty-one of these 31 outbreaks were caused by S. Enteritidis PT34, but 8 outbreaks were caused by S. Enteritidis PT4. After 1990 instead of SE PT34, food poisoning due to PT4, which was a very common phage type in the UK, has increased in Tokyo. Between 1989 and 1995, there were 144 food poisoning outbreaks caused by S. Enteritidis, and 64 of these outbreaks were by due to S. Enteritidis PT4, which was one of the main phage types in Tokyo. To characterize these strains of phage type (PT) 4,293 isolates from patients, and vehicle foods, eggs and environment in Tokyo were examined for plasmid DNA profiles, acid productivity from glycols (propylene and ethylene) and antimicrobial resistance patterns. Plasmid DNA was extracted by Kado's method, and analyzed by agarose gel electrophoresis. The acid productivity from propylene glycol or ethylene glycol were tested using Barsicow medium with 1% propylene glycol or ethylene glycol. Antimicrobial susceptibility to AM, CP, TC, SM, KM, NA, ST, FOM and NFLX was tested by the K-B disc method. The strains of PT4 were further subdivided into 9 types by those epidemiologic marker analysis. The prevalent pattern of PT4 strains was type A plasmid profile carrying only one plasmid (60 kb) and there were 2 kinds of antibiograms. One was SM resistant, while the other was susceptible. A total of 56 (87.5%) of 64 outbreaks was found to have been caused by these types of S. Enteritidis. Several kinds of egg-related foods were suspected as the vehicles of transmission among 24 outbreaks. Especially, in 5 outbreaks, S. Enteritidis strains were isolated both from patients and suspected food which were cooked with egg. This strongly suggests that these foods may be the potential source of infection in S. Enteritidis PT4 outbreaks.

Anti-Bacterial Agents↗
PubMed1997

[A case of primary HIV-1 infection].

A previously healthy 28 year old Japanese man came to us with a genital ulcer which appeared 13 days before admission to our hospital. He had subsequently fever (40 degrees C), arthralgia, a sore throat and oral aphtha 6 days before admission. He had a history of sexual contact with a female commercial sex worker one week before his illness. On the day of admission, he had shallow ulcers on the lip, tongue and penis. Initial laboratory test included leukopenia and thrombocytopenia. His fever abated 3 days after admission. His condition and bicytopenia recovered completely after 12 days of admission. Although, his serum HIV-1 antibody was negative when he was admitted, 3 months later the antibody was seroconverted. And p24 antigen and HIV-1 RNA of stocked serum were positive. Diagnosis of primary HIV-1 infection was made. Recently, HIV-1 infection has been increasing in Japan. Consideration of this disease in differential diagnosis of acute febrile illness is necessary.

Adult↗
PubMed1997

Phosphatidylinositol 4,5-bisphosphate phosphatase regulates the rearrangement of actin filaments.

Phosphatidylinositol 4,5-bisphosphate (PIP2) reorganizes actin filaments by modulating the functions of a variety of actin-regulatory proteins. Until now, it was thought that bound PIP2 is hydrolyzed only by tyrosine-phosphorylated phospholipase Cgamma (PLCgamma) after the activation of tyrosine kinases. Here, we show a new mechanism for the hydrolysis of bound PIP2 and the regulation of actin filaments by PIP2 phosphatase (synaptojanin). We isolated a 150-kDa protein (p150) from brains that binds the SH3 domains of Ash/Grb2. The sequence of this protein was found to be homologous to that of synaptojanin. The expression of p150 in COS 7 cells produces a decrease in the number of actin stress fibers in the center of the cells and causes the cells to become multinuclear. On the other hand, the expression of a PIP2 phosphatase-negative mutant does not disrupt actin stress fibers or produce the multinuclear phenotype. We have also shown that p150 forms the complexes with Ash/Grb2 and epidermal growth factor (EGF) receptors only when the cells are treated with EGF and that it reorganizes actin filaments in an EGF-dependent manner. Moreover, the PIP2 phosphatase activity of native p150 purified from bovine brains is not inhibited by profilin, cofilin, or alpha-actinin, although PLCdelta1 activity is markedly inhibited by these proteins. Furthermore, p150 suppresses actin gelation, which is induced by smooth muscle alpha-actinin. All these data suggest that p150 (synaptojanin) hydrolyzes PIP2 bound to actin regulatory proteins, resulting in the rearrangement of actin filaments downstream of tyrosine kinase and Ash/Grb2.

Actin Cytoskeleton↗
PubMed1997

Pancreatitis: evaluation with MR cholangiopancreatography in children.

PURPOSE: To determine the usefulness of magnetic resonance (MR) cholangiopancreatography in assessing the cause of pancreatitis in children. MATERIALS AND METHODS: Twenty healthy volunteers (aged 2-11 years) and 10 patients with acute pancreatitis (aged 3-12 years) who underwent MR cholangiopancreatography between December 1993 and February 1996 were studied retrospectively. The rate of visualization of the common bile duct and main pancreatic duct with MR cholangiopancreatography was assessed in the volunteer group. Depiction of pancreaticobiliary disease at MR cholangiopancreatography was assessed in the patient group. RESULTS: MR cholangiopancreatography clearly showed the common bile duct in 20 of 20 volunteers (100%) and the main pancreatic duct in 13 of 20 volunteers (65%). MR cholangiopancreatography depicted a dilated common bile duct in six of 10 patients (60%) and an abnormal arrangement of the pancreaticobiliary duct in five of the six patients (83%) in whom this structural abnormality was proved at surgery. In the four patients without structural abnormality, MR cholangiopancreatography depicted a pseudocyst in one patient who had traumatic pancreatitis; the other three patients had normal findings. In one of these three patients, familial pancreatitis was considered to be the underlying disorder, and in the other two patients no cause was identified. CONCLUSION: MR cholangiopancreatography may be helpful in diagnosing the cause of pancreatitis in children, especially in those with an abnormal pancreaticobiliary ductal junction.

Acute Disease↗
PubMed1997

A monoclonal antibody recognizing nestin and the phosphorylated form of neurofilament-M.

In the course of an immunohistochemical screening of antibodies raised against a postnatal day 7 rat brain membrane fraction, we obtained a monoclonal antibody that recognizes both neurofilament-M, a type VI intermediate filament protein, and nestin, a type IV intermediate filament protein. In newborn rat cerebellum, the 5A7 antibody stained Bergmann glial fibers and subsets of axons simultaneously, but in adult cerebellum it only stained neuronal elements. Upon immunoblot analysis of neonatal rat cerebellum, 5A7 gave two prominent bands corresponding to 140 and > 200 kDa. The former was identified as neurofilament-M and the latter as nestin. Dephosphorylation of neurofilament-M resulted in a dramatic reduction in the immunoreactivity, indicating that 5A7 recognized the phosphorylated form of neurofilament-M. Immunoblot analysis of V8 protease digests of neurofilament-M revealed that the epitope on neurofilament-M is located on the carboxy-half of the tail domain of neurofilament-M. These results indicate that 5A7 is the first monoclonal antibody which recognizes a common or similar epitope on different classes of intermediate filament proteins other than the conserved rod domain. The presence of a common or similar epitope on both nestin and neurofilament-M recognized by 5A7 may suggest the possibility that nestin and neurofilament-M have a common functional motif.

Animals↗