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T Yamada

Publications and source records attributed to T Yamada.

At least 217 records · Page 12Linked to original sources
PubMed2001

Effects of glucose on formation of cytotoxic end-products and proteolytic activity of Prevotella intermedia, Prevotella nigrescens and Porphyromonas gingivalis.

Black-pigmented bacteria which produce cytotoxic metabolic end-products and cell membrane-associated proteases have been reported to play an important role in the pathogenesis of periodontal diseases. These bacterial virulence factors can be modified by the environmental conditions including nutrients supplied variously into the oral cavity. Although glucose is one of the most essential nutrients for oral bacteria, the exogenous supply of glucose may be discontinuous and the glucose concentration in a periodontal pocket may be influenced by the depth of the periodontal pocket. Therefore, effects of glucose as an environmental factor on the virulence factors of Prevotella intermedia, Prevotella nigrescens and Porphyromonas in the presence o glucose.,bo t P. intermedia and P. nigrescens markedly decreased the production of cytotoxic end-products including succinate.,isobutyrate,isovalerate and ammonia, although their growth was increased. Furthermore, the proteolytic activities such as immunoglobulin- albumin- and casein-degrading activities of these bacteria were decreased in the presence of glucose. On the other hand, no effect of glucose on the metabolic activity of P gingivalis was observed. These results suggest that pathogenicity of P. intermedia P. nigrescens may be decreased by the presence of glucose.

Ammonia↗
PubMed2001

Massive intravenous immunoglobulin treatment in women with four or more recurrent spontaneous abortions of unexplained etiology: down-regulation of NK cell activity and subsets.

PROBLEM: The aims of this study were to investigate the efficacy of massive intravenous immunoglobulin (MIVIg) treatment for women with recurrent spontaneous abortion (RSA) of unexplained etiology, and to investigate changes in peripheral natural killer (NK) cell activity and subsets. METHOD OF STUDY: MIVIg treatment was performed in 18 pregnancies from 15 women with 4 or more consecutive RSA of unexplained etiology. NK cell activity and subsets were assessed in 8 of the pregnancies. RESULTS: 14 pregnancies resulted in live births and 4 resulted in abortions with chromosome abnormality. The pre-infusion NK cell activity (mean + SD. 40.9 + 17.0%) at 4.4 +/- 0.5 weeks of gestation (GW) decreased to 15.0 +/- 7.90% at post-infusion status (5.4 +/- 0.5 GW). Pre-infusion percentages of CD56+ CD16- cells (3.5 +/- 2.1%) and CD56+ CD16- cells (16.8 +/- 8.8%) decreased to 3.0 +/- 2.2% and 11.1 +/- 6.9%, respectively, after MIVIg treatment. CONCLUSIONS: MIVIg treatment was effective in all 14 pregnancies from RSA women of unexplained etiology, excluding 4 abortions with chromosome abnormality. Peripheral NK cell activity and subsets were suppressed by MIVIg treatment.

Abortion, Habitual↗
PubMed2001

A novel differentiation-inducing therapy for acute promyelocytic leukemia with a combination of arsenic trioxide and GM-CSF.

Arsenic trioxide (As2O3) effectively induces clinical remission via apoptosis in relapsed acute promyelocytic leukemia (APL). However, because this new anti-leukemic drug is also considered to be a poison, its possible adverse effects are a highly important issue related to its clinical use. We here investigated, both in vitro and in vivo, the effects of a combination of As2O3 and GM-CSF as a novel therapeutic approach for the treatment of APL. Treatment of both retinoic acid (RA)-sensitive and -resistant APL cell lines (NB4 and UF-1 cells, respectively), as well as primary APL cells with a combination of As2O3 and GM-CSF for 4 days resulted in inducing differentiation, but not apoptosis, to mature granulocytes. In addition, a combination of both agents induced degradation of the PML/RARalpha protein. GM-CSF was found to be associated with increased tyrosine phosphorylation of Jak2 kinase in both NB4 and UF-1 cells, and a specific inhibitor of Jak2, AG490, completely blocked the ability of GM-CSF to prevent apoptosis and induce differentiation of As2O3-treated UF-1 cells. In in vivo analysis, As2O3 induced differentiation of APL cells in a RA-resistant APL model of human GM-CSF-producing transgenic SCID mice that had a high level of human GM-CSF in their sera. In contrast, As2O3 alone diminished tumors in UF-1 cells transplanted into NOD/SCID mice via induction of apoptosis. In conclusion, a combination of As2O3 and GM-CSF appears to be a novel differentiation-inducing therapy in patients with APL, including relapsed or RA-resistant cases.

Animals↗
PubMed2001

Five-day proton pump inhibitor-based quadruple therapy regimen is more effective than 7-day triple therapy regimen for Helicobacter pylori infection.

BACKGROUND: There have been no reports that describe whether 5-day quadruple therapy (rabeprazole + amoxicillin + clarithromycin + metronidazole; RACM) could substitute for standard 7-day triple therapy as a first-line therapy for Helicobacter pylori. PATIENTS AND METHODS: This study was designed as a randomized prospective single centre study. A total of 160 H. pylori-positive patients who had not received therapy were given either a 5-day RACM regimen (n=80, rabeprazole 20 mg b.d., amoxicillin 750 mg b.d., clarithromycin 200 mg b.d. and metronidazole 250 mg b.d.) or a 7-day RAC regimen (n=80, rabeprazole 20 mg b.d., amoxicillin 750 mg b.d. and clarithromycin 200 mg b.d.). Cure of the infection was assessed by a (13)C urea breath test 1 month after the completion of therapy. RESULTS: The eradication rates of the 5-day RACM regimen and the 7-day RAC regimen were 93% (95% CI: 84--97%) and 81% (95% CI: 71--89%) by intention-to-treat analysis, 94% (95% CI: 86--98%) and 83% (95% CI: 73--91%) by all-patients-treated analysis analysis and 95% (95% CI: 87--98%; P < 0.05) and 82% (95% CI: 72--90%) by per protocol analysis, respectively. No serious adverse effect was observed, and 99% of the patients reported complete compliance. CONCLUSIONS: The cure rate of the 5-day RACM regimen was more effective than the 7-day RAC regimen, suggesting that this regimen could be preferable as a first-line therapy for H. pylori infection.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2001

Analysis of expressed sequence tags from a cDNA library of somatic nuclear transfer-derived cloned bovine whole foetus.

The expression profile of genes in specific tissues is studied through analysing expressed sequence tags (ESTs) and provides useful information for characterizing gene function and tissue physiology. Analysis of ESTs is achieved by partial sequencing and characterization of clones isolated randomly from cDNA libraries. In the present study, we analysed the genes expressed in the somatic nuclear transfer-derived cloned bovine foetus in the early period of foetal development. To this aim, we constructed a directionally cloned cDNA library from somatic nuclear transfer-derived cloned 60 day-old whole foetus of cattle and sequenced 3' end of 510 randomly isolated clones. By BLASTN analysis, we identified 403 unique clones: 186 showed homology to previously identified genes, 123 matched uncharacterized ESTs and 94 showed no significant matches to sequences already present in DNA databases. Analysis of these cDNA clones revealed that this library contained a variety of functional genes, while foetuin, insulin-like growth factor 2, collagen type I alpha I and maternal G10 transcript genes were the most abundant transcripts. Our study allowed the establishment of a first list of genes expressed in bovine whole foetus. In future, the list of genes might help facilitate the understanding of physiology of foetal development in somatic nuclear transfer-derived cloned bovine foetus.

Animals↗
PubMed2001

Molecular cloning, expression analysis, promoter characterization, and chromosomal localization of the bovine PREF1 gene.

Pre-adipocyte factor-1 (pref-1), originally identified in mouse 3T3-L1 pre-adipocytes, is known to play a key role in inhibiting the adipose conversion. As a first step to study the involvement of the PREF1 gene in intramuscular adipose tissue development in cattle, which has an economic importance for beef cattle, we have isolated the bovine PREF1 cDNA and genomic clones and characterized expression in abdominal adipose and promoter region of the bovine PREF1 gene. We have detected two bovine PREF1 splice-isoforms, PREF1C2 and PREF1A, in abdominal fat tissue. The RT-PCR experiment revealed that the two isoforms are identified in neonatal, but no in adult abdominal fat tissue, suggesting age-dependent suppression of the bovine PREF1 gene expression in the form of PREF1C2 and PREF1A in abdominal fat tissue. By mapping the regulatory region of this gene, we have shown that at least two regions within 1121 bp upstream of putative transcription start site are sufficient to confer promoter activity, when accompanied by a short region including the transcription start site. The chromosomal location of the PREF1 gene was determined by fluorescence in situ hybridization (FISH). The PREF1 gene locates on bovine chromosome 21q24.

3T3 Cells↗
PubMed2001

Extinction of expression of the genes encoding haematopoietic cell-restricted transcription factors in T-lymphoma x fibroblast cell hybrids.

We previously reported that expression of the T-cell receptor (TCR) alpha and lck genes is extinguished in hybrids between mouse T-lymphoma EL4 cells and mouse fibroblast B82 cells. In the present study, we found that the activities of the TCRalpha minimum enhancer and the lck promoter monitored by the luciferase or chloramphenicol acetyltransferase (CAT) assays were markedly inhibited in the hybrids. Expression of the TCF-1, LEF-1, GATA-3, Ikaros, c-myb and Fli-1 genes, which encode the haematopoietic cell-restricted transcription factors that appear to be responsible for the activities of the enhancer and the promoter, was fully extinguished or markedly suppressed in the hybrids. On the other hand, expression of the transcription factor genes observed in both parental cells, such as the AML1 and c-ets-1 genes, and that of the genes encoding ubiquitously expressed transcription factors, such as the E2A, CREB and c-ets-2 genes, was not significantly suppressed in the hybrids. These results suggest that the genes encoding haematopoietic cell-restricted transcription factors are targets for negative regulation in fibroblastic background and that the repression of these genes may consequently lead to suppression of the promoter and/or enhancer activities of several T-cell-specific structural genes in T-lymphoma x fibroblast cell hybrids.

Animals↗
PubMed2001

The dynamic behaviour of a lower complete denture during unilateral loads: analysis using the finite element method.

The purpose of this study was to analyse the correlation between the location and/or direction of unilateral load and the dynamic behaviour of a mandibular complete denture using the three-dimensional finite element method (FEM). The FE model consisted of the body of mandible, alveolar mucosa, and a complete denture, and it could simulate the condition of contact between the surface of the mucosa and mucosal surface of a denture. Load vectors, which simulated premature contacts, were calculated on the supposition that a premature contact on an occlusal facet causes a vertical load on it. Load-A, a load vertical to the anterior occlusal facet, caused the least displacement of the denture and less concentrated stress distribution. Load-P, a load vertical to the posterior occlusal facet, was characterized by the stress distributed in the lingual area of the pre-molar lesion on the contra-lateral side of the load. Load-B, a load vertical to the balancing occlusal facet, caused the largest displacement of the denture. The relationship between loads and stress distribution was agreed approximately with the observations previously reported, and lead to some suggestions about occlusion for complete dentures.

Alveolar Process↗
PubMed2001

Relationship between the stress distribution and the shape of the alveolar residual ridge--three-dimensional behaviour of a lower complete denture.

PURPOSE: For a complete denture to function effectively, the denture must be stabilized during mastication. The alveolar ridge has various forms, and we must choose the artificial tooth arrangement that is most suitable to the form of the alveolar ridge. The purpose of this study was twofold: (i) to examine the relationship between the alveolar ridge form and the stress distribution on the mucosa, and (ii) to model the contact condition between the denture base surface and mucosa. MATERIALS AND METHODS: In this study, the three-dimensional finite element method was used for the analysis. Four types of alveolar ridge were prepared. As a loading condition, three load places were prepared: the mesial position, the central position and the distal position. We utilized the 'contact option (MARC)' to simulate the true behaviour of the denture. RESULTS: We were able to model the contact condition by using the 'contact option'. Maximum stresses were distributed on the alveolar ridge in which the absorption is severe. And, the distal load produced large compressive stresses on the inclined plane of posterior alveolar ridge in which alveolar form.

Alveolar Bone Loss↗
PubMed2001

Strategy for retreatment of therapeutic failure of eradication of Helicobacter pylori infection.

BACKGROUND AND AIM: A proton pump inhibitor (PPI)-based triple therapy consisting of a PPI, amoxicillin (A) and clarithromycin (C) or metronidazole (M) provides an eradication rate ranging from 80 to 90%. However, there have been few controlled studies with regard to the most effective regimen to re-treat patients after failure of the first-line therapy. Accordingly, we retrospectively reviewed our experiences and compared regimens with different combinations of antimicrobials to determine the optimal retreatment regimen. METHODS: Out of 133 patients who had received second-line therapy after failure of first-line PPI/AC therapy, we selected, for review, patients who took the prescribed drugs for first-line therapy equal to, or more than 80%. As a result, data on 114 patients (83 males and 31 females; mean age 49.1 +/- 13.0 years; peptic ulcer n = 89; non-ulcer dyspepsia, n = 25) were eligible for evaluation. They had either repeated the PPI/AC regimen (n = 34; 5-14 days), or had been administered the PPI/AM regimen (n = 80; 10 days). The cure rates of the two regimens were compared. RESULTS: The eradication rates for second-line therapy with the PPI/AC regimen versus the PPI/AM regimen were 52.9% (95% CI, 35-70) versus 81.3% (95% CI, 71-89) by intention-to-treat analysis (P < 0.01), and 62.1% (95% CI, 42-79) versus 91.4% (95% CI, 81-97) by per-protocol analysis (P < 0.01). CONCLUSION: The eradication rate for the PPI/AM retreatment regimen was significantly higher than for the repeated PPI/AC regimen, suggesting that a 10-day PPI/AM regimen can be recommended as a retreatment regimen for patients who had first-line eradication therapy by PPI/AC regimens.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2001

Prevalence of Alzheimer's disease, vascular dementia and dementia with Lewy bodies in a Japanese population.

We studied the prevalence of dementing disorders in a rural town of Japan (Amino-cho), using a door-to-door two-phase design. Of the 170 persons screened as having cognitive impairment, 142 cases were diagnosed as having dementia. The prevalence (cases/100 aged 65 years older) was 3.8 for all types of dementia, 2.1 for Alzheimer's disease (AD), 1.0 for vascular dementia (VD) and 0.7 for other types of dementia. Among other types of dementia, there were four male patients with dementia with Lewy bodies (prevalence: 0.1), but no patients with frontotemporal lobar degeneration. The overall prevalence was higher in women for AD, while that of VD was the same in both sexes. With results similar to many previous studies in Western countries and some recent surveys in Japan, the present sudy clearly showed that AD is more prevalent than VD.

Aged↗
PubMed2001

Deep vein thrombosis during chemotherapy in a patient with advanced testicular cancer: successful percutaneous thrombectomy under temporary placement of retrievable inferior vena cava filter.

A 27-year-old man with advanced testicular cancer experienced two events of deep vein thrombosis (DVT) during three cycles of cisplatin-based combination chemotherapy; the first thrombotic event occurred in the inferior vena cava (IVC) following the initial two cycles of chemotherapy and the second thrombotic event occurred in the right iliac vein following the third cycle. For both thrombotic events, he was successfully managed with thrombolytic therapy and percutaneous thrombectomy using a transcatheter hydraulic thrombectomy device under temporary placement of a retrievable IVC filter. Stasis of the IVC due to compression by a retroperitoneal lymphadenopathy of 7 cm in diameter, which was demonstrated on computed tomographic scans at presentation, was considered a major cause of DVT during chemotherapy. Patients with bulky retroperitoneal disease causing stasis of major veins are at high risk of DVT associated with chemotherapy and thromboprophylaxis should be strongly considered during their chemotherapy.

Adult↗
PubMed2001

Need for sling surgery in patients with large cystoceles and masked stress urinary incontinence.

BACKGROUND: We studied the need for sling surgery in patients who suffered from large cystoceles and masked stress urinary incontinence. METHODS: Twenty patients who had large cystoceles but neither evidence nor history of stress incontinence were enrolled in this study. The cystocele was reduced using a reducing device. Masked urinary incontinence was identified by a 60 m pad weighing test and a stress test. The cystocele was reduced using a pessary ring in 14 patients, or a vaginal pack formed of two rolls of ordinary 28 x 28 cm gauze in six patients. Ten of 20 patients were diagnosed with masked stress urinary incontinence and were treated with anterior colporrhaphy and a suburethral sling procedure. The other 10 patients were continent after use of a cystocele reducing device and were treated with anterior colporrhaphy alone. Average follow-up periods of the patients with or without masked stress urinary incontinence were 51.2 months (range, 24.0-72.0 months) or 57.6 months (range, 27.0-70.0 months), respectively. RESULTS: One of the 10 patients diagnosed with masked stress incontinence had mild stress urinary incontinence postoperatively. None of the 10 continent patients had stress incontinence after anterior colporrhaphy alone. CONCLUSIONS: Reducing devices of protruding cystocele were clinically useful in the detection of masked stress incontinence. Sling surgery was effective to prevent emerging stress urinary incontinence for patients who suffered from cystocele and masked stress incontinence.

Aged↗
PubMed2001

Prognosis of conservative therapy of advanced interstitial cystitis: experience of five cases.

BACKGROUND: It is generally believed that surgical procedures, particularly the more invasive ones, should be reserved for patients who fail to respond to conservative therapy by several established modalities. We studied whether conservative therapy was applicable to patients with interstitial cystitis (IC) in which an individual's awake bladder capacity decreases to 100 mL or less with vesicoureteral reflux (VUR). METHODS: Five cases that satisfied the criteria proposed by the National Institutes of Health were examined. The maximum awake bladder capacity was 50-100 mL (average, 74 mL). The bladder capacity under anesthesia was 70-300 mL (average, 199 mL). Only conservative treatments were carried out. RESULTS: The observation period ranged from 3 to 16 years with an average of 9 years. The awake bladder capacity ranged from 200 to 300 mL (average, 250 mL). The symptom index total score, which was previously 18.5, decreased to 5.5 and the problem index total score, which was previously 14.3, decreased to 3.5. Symptoms of bladder irritation improved. In four cases, VUR disappeared as the bladder capacity increased. Vesicoureteral reflux persisted in one case although its severity decreased and there was no fever. CONCLUSION: The patients treated with conservative therapy were able to maintain an awake bladder capacity that was sufficient for acceptable quality of life and their symptoms of bladder irritation improved. This suggests that we should regenerate the original remaining bladder using conservative therapy, even if IC is in a late stage.

Administration, Intravesical↗
PubMed2001

Polytetrafluoroethylene patch sling for type 2 or type 3 stress urinary incontinence.

BACKGROUND: Surgical success rates and complications of anti-incontinence surgery were evaluated according to the type of stress incontinence and the type of surgery. METHODS: From 1989 to 1998, we treated 137 women for stress urinary incontinence with anti-incontinence surgery. Of the 137 patients, 110 had type 2 stress urinary incontinence and 27 had type 3 stress urinary incontinence. Of 110 patients with type 2 stress urinary incontinence, 57 underwent pubovaginal sling procedure and 53 were treated with the Gittes procedure. All of the patients with type 3 stress urinary incontinence underwent the pubovaginal sling procedure. RESULTS: Cure rates with the pubovaginal sling procedure were 82% in type 2 incontinence and 70% in type 3 incontinence. Cure rates with the Gittes procedure were 56%. The occurrence of de novo urge symptom and pelvic pain was low and bore no relation to either operative method or type of stress incontinence. CONCLUSIONS: The pubovaginal sling procedure using the polytetrafluoroethylene patch was effective for type 2 or 3 stress urinary incontinence.

Female↗