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T Hosoi

Publications and source records attributed to T Hosoi.

At least 19 recordsLinked to original sources
PubMed2003

Wear resistance of experimental Ti-Cu alloys.

After using cast titanium prostheses in clinical dental practice, severe wear of titanium teeth has been observed. This in vitro study evaluated the wear behavior of teeth made with several cast titanium alloys containing copper (CP Ti+3.0 wt% Cu; CP Ti+5.0 wt% Cu; Ti-6Al-4V +1.0 wt% Cu; Ti-6Al-4V+4.0 wt% Cu) and compared the results with those for commercially pure (CP) titanium, Ti-6Al-4V, and gold alloy. Wear testing was performed by repeatedly grinding upper and lower teeth under flowing water in an experimental testing apparatus. Wear resistance was assessed as volume loss (mm(3)) at 5kgf (grinding force) after 50,000 strokes. Greater wear was found for the six types of titanium than for the gold alloy. The wear resistance of the experimental CP Ti+Cu and Ti-6Al-4V+Cu alloys was better than that of CP titanium and Ti-6Al-4V, respectively. Although the gold alloy had the best wear property, the 4% Cu in Ti-6Al-4V alloy exhibited the best results among the titanium metals. Alloying with copper, which introduced the alpha Ti/Ti(2)Cu eutectoid, seemed to improve the wear resistance.

Alloys↗
PubMed2003

Effects of bezafibrate and pravastatin on remnant-like lipoprotein particles and lipoprotein subclasses in type 2 diabetes.

The effects of bezafibrate and pravastatin on remnant-like lipoprotein particles (RLPs) and lipoprotein subclasses were compared in type 2 diabetes. Bezafibrate (400 mg/day) and pravastatin (10 mg/day) were given to 27 Japanese diabetics in a randomized crossover design. RLP cholesterol (RLP-C) and RLP triglyceride (RLP-TG) were measured by an immunoseparation technique. LDL and HDL were separated each into three subclasses (large, medium, small) and their cholesterol (C) contents were measured by an HPLC method. RLP-C was reduced more effectively by pravastatin (bezafibrate -16.0% vs. pravastatin -40.6%, P < 0.05), whereas RLP-TG was reduced more effectively by bezafibrate (-55.2% vs. -35.0%, P < 0.05). Further, pravastatin decreased large and small LDL-C levels equally (large; -23.6%; medium; -17.2%, small; -21.0%), while bezafibrate produced a relatively larger reduction in small LDL-C (-12.1; -16.9; -21.5%). Whereas bezafibrate significantly decreased large HDL-C and increased medium and small HDL-C (-49.6; 34.1; 35.8%), pravastatin significantly increased only medium HDL-C (5.2; 9.4; 5.9%). Bezafibrate reduced RLP-C and RLP-TG more effectively in patients with high TG levels, whereas pravastatin's effect was not markedly influenced by the initial TG level. Thus measurements of RLP-C, RLP-TG, and HPLC subclasses revealed that bezafibrate and pravastatin differently influence the lipoprotein status in type 2 diabetes.

Aged↗
PubMed2003

Breast carcinoma in women over the age of 85: distinct histological pattern and androgen, oestrogen, and progesterone receptor status.

AIMS: The pathogenesis of breast carcinoma in very elderly women is of interest, because oestrogen levels are likely to be extremely low during the development of the disease. In an effort to understand the pathogenesis of breast carcinoma in these women, this study was undertaken to compare the histological patterns and hormone receptor status of breast carcinomas arising in very elderly and younger women. METHODS AND RESULTS: Thirty-seven breast carcinomas from women over the age of 85 years at the time of their operation were examined histologically and compared with those from a large group of premenopausal women. The proportions of mucinous carcinoma and apocrine carcinoma were significantly greater in older women. The expression of steroid hormone receptors was studied immunohistochemically. Androgen receptor-positive carcinomas were significantly more frequent among older women, whereas progesterone receptor-positive carcinomas were significantly less frequent. There was no statistically significant difference in oestrogen receptor-alpha or -beta expression between the tumours from both groups. CONCLUSION: Breast carcinomas in women over the age of 85 years have a different morphological spectrum from carcinomas in younger age groups and may have different pathogenesis mechanisms that may be more dependent on androgen and androgen receptor interaction. Differences from the results of the other studies are discussed.

Adenocarcinoma↗
PubMed2002

Association of klotho gene polymorphism with bone density and spondylosis of the lumbar spine in postmenopausal women.

Based on the fact that the klotho-deficient mouse exhibits multiple aging phenotypes, including osteopenia and subchondral sclerosis of joints, we explored the possibility of whether human klotho gene polymorphism is associated with two major age-related skeletal disorders: osteoporosis and spondylosis. Analysis of the CA repeat sequence downstream of the final exon of the klotho gene identified ten types of alleles in Japanese postmenopausal women (n = 377). We investigated the association of this microsatellite polymorphism with bone density and spondylosis score of the lumbar spine. None of the genotypes was associated with bone density in the overall population (n = 377; 754 alleles) nor in the subpopulation at not more than 10 years after menopause ( 20 years after menopause (n = 102; 204 alleles, p = 0.024). The type 7 allele was associated with high bone density in women more than 20 years after menopause (p = 0.042). The association study with spondylosis of postmenopausal women (n = 221) revealed that another distinct allele, type 8, was significantly associated with low spondylosis score at L-4/5 (p = 0.019) and L-5/S-1 (p = 0.048) levels in the subpopulation equal to or younger than the average age (<or=63 years old, n = 119; 238 alleles), but not in the older subpopulation. These findings indicate that the klotho gene may be a candidate for the genetic regulation of common age-related diseases like osteoporosis and spondylosis, and we provide the first evidence suggesting that this gene may be involved in the etiology of human diseases.

Adult↗
PubMed2002

Gastrin and Helicobacter pylori in low-grade MALT lymphoma patients.

BACKGROUND: This study of patients with Helicobacter pylori infection and low-grade MALT lymphoma aimed to investigate: 1) the effect of H. pylori eradication therapy on the serum gastrin level, 2) whether changes of the serum gastrin level after therapy could predict the prognosis of patients with this tumour, and 3) the relationship between the gastric H. pylori load, the serum gastrin level and the status of MALT lymphoma. METHODS: Thirteen patients with documented low-grade MALT lymphoma and H. pylori infection were enrolled and received H. pylori eradication therapy as the sole initial treatment. The presence of H. pylori, the serum gastrin level, the endoscopic findings, the pathologic features of the biopsies and resected specimens, and the endoscopic ultrasonography findings were evaluated before and after therapy. Follow-up was carried out every 3-6 months. RESULTS: H. pylori eradication was eventually achieved in all 13 patients. The pretreatment fasting serum gastrin level decreased from 177.1 +/- 107.4 pg/ml to 129.2 +/- 78.1, 96.4 +/- 66.6 and 80.1 +/- 42.7 pg/ml after 0-3, 3-6 and 6-9 months, respectively (all P < 0.05). Successful eradication of H. pylori was followed by a decrease of the fasting serum gastrin level and complete regression of initial low-grade MALT lymphoma was observed in all patients. However, two patients subsequently developed recurrent high-grade MALT lymphoma or high-grade lymphoma. In one of them, the serum gastrin level rose again above the pretreatment value. In the other, however, the fasting gastrin level fell throughout the study period. The median fasting serum gastrin level before H. pylori eradication therapy was higher in the patients with tumours of the gastric body (203.4 +/- 108.9 pg/ml) than in those with tumours of the antrum and angulus (89.3 +/- 28.0 pg/ml) (P = 0.06). CONCLUSIONS: Hypergastrinaemia may be associated with an increased risk of gastric MALT lymphoma.

Adult↗
PubMed2001

Calcium requirement estimated by balance study in elderly Japanese people.

The recommended dietary allowance (RDA) for calcium (Ca) of Japanese adults is proposed to be 600 mg/day, which is lower than those of other countries. In this report we estimated the Ca requirement and the RDA for Ca in elderly Japanese utilizing a Ca balance method. Subjects were 10 men aged 65-72 years and 10 women aged 62-77 years. Following a 14 day adaptation period, each participant was subjected to a low Ca diet (Ca 250 mg as a meal) for 6 days. After an interval of 2 weeks or more, another 14 day adaptation period was set and then a high Ca diet (Ca 250 mg as a meal and 600 mg as CaCO3) was served to the subjects for 6 days. Ca balance was calculated at each dose of Ca intake. Ca requirement was estimated by the intersection of the average Ca intake-retention diagram. Daily Ca requirement was 702 mg in the men and 788 mg in the women. The Ca requirement values were multiplied by 1.2 to obtain the RDA for Ca. As a result, RDA for Ca was 842 mg/day for men and 946 mg/day for women. When these values were normalized with the body weight, the RDA for Ca of Japanese and Caucasian women was similar (18.1 and 18.5 mg/kg body weight per day, respectively). Our results suggest the difference in Ca balance between the genders and among populations may be ascribed at least partly to differences in body size. In addition, body weight should be considered when comparing the RDAs among different populations.

Aged↗
PubMed2001

A polymorphic variant at the Werner helicase (WRN) gene is associated with bone density, but not spondylosis, in postmenopausal women.

Werner syndrome (WS) is a rare autosomal recessive progeroid syndrome characterized by the premature onset of multiple age-related disorders. The gene responsible for WS has been identified as WRN, a member of the RecQ family of helicase genes. Based on the fact that patients with WS exhibit osteoporosis and osteoarthritis, the present study was undertaken to clarify the contribution of the WRN gene to the etiology of these two common age-related disorders in normal postmenopausal women. We investigated the association of a WRN gene polymorphism, namely c.4330 T --> C leading to an amino acid substitution from Cys to Arg, with bone density and lumbar spondylosis score in unrelated Japanese postmenopausal women (n = 377). Genotypic frequencies of T/T, T/C, and C/C were 87.5%, 12.2%, and 0.3%, respectively. Bone density of the lumbar spine (L2-4) was significantly lower in women carrying the minor C allele than in non-carriers (P = 0.037). When bone density was expressed by the Z score after being adjusted by age and weight, carriers of the C allele showed lower values not only in the lumbar spine, but also in the total body (P = 0.015 and 0.042, respectively). The association study with spondylosis in postmenopausal women (n = 221) revealed that this polymorphism was not related to the severity of spondylosis expressed by the Kellgren-Lawrence score at any disk level of the lumbar spine (L2/3-L5/S1). These findings indicate that the WRN gene may be a candidate for the genetic regulation of osteoporosis, but not spondylosis, in normal Japanese postmenopausal women.

Aged↗
PubMed2001

A nucleotide variant in the promoter region of the interleukin-6 gene associated with decreased bone mineral density.

Interleukin-6 (IL6) has come to be regarded as a potential osteoporotic factor because it has stimulatory effects on cells of the osteoclast lineage, and, thus, may play a role in the pathogenesis of bone loss associated with estrogen deficiency. We previously described association of the IL6 microsatellite with bone mineral density (BMD), as well as genetic linkage of the IL6 locus to human osteoporosis, by means of sib-pair analysis. However, the molecular mechanism by which this locus regulates BMD remains unknown. Accordingly, we searched for polymorphisms in the 5' and 3' flanking regions and in all five exons of the IL6 gene in a Japanese population sample. We identified three single-nucleotide sequence variations: a C/G substitution at nucleotide (nt) -634 in the promoter region, a G/A substitution at nt 4391 in the 3' noncoding region, and a variation in the AnTn tract around nt -447. The last of these had already been observed in Caucasians, as well as in Japanese. The single-nucleotide polymorphism at -634 created a restriction site for the BsrBI endonuclease, and the frequency of the minor (G) allele was 0.184. Five haplotypes were constructed among three variations examined in the population. Linkage disequilibrium was observed between the variation at -634 and the variation at 4391, as well as between the variation at -634 and the AnTn tract variation. We found a significant correlation, in 470 subjects, between the presence of the G allele and decreased BMD, by analysis of variance. When BMD values were compared among the three genotypic groups (G/G, G/C, C/C) at nt -634, BMD was lowest among the G/G homozygotes (mean +/- SD; 0.284 +/- 0.062g/cm2), highest among the C/C homozygotes (0.314 +/- 0.059g/cm2), and intermediate among the heterozygotes (0.303 +/- 0.066g/cm2; P < 0.05). Given the several lines of evidence from different genetic studies, we suggest that IL6 is, indeed, one of the genes affecting bone metabolism, in which variations can lead to osteoporosis.

Absorptiometry, Photon↗
PubMed2001

Japanese fermented soybean food as the major determinant of the large geographic difference in circulating levels of vitamin K2: possible implications for hip-fracture risk.

Increasing evidence indicates a significant role for vitamin K in bone metabolism and osteoporosis. In this study, we found a large geographic difference in serum vitamin K2 (menaquinone-7; MK-7) levels in postmenopausal women. Serum MK-7 concentrations were 5.26 +/- 6.13 ng/mL (mean +/- SD) in Japanese women in Tokyo, 1.22 +/- 1.85 in Japanese women in Hiroshima, and 0.37 +/- 0.20 in British women. We investigated the effect of Japanese fermented soybean food, natto, on serum vitamin K levels. Natto contains a large amount of MK-7 and is eaten frequently in eastern (Tokyo) but seldom in western (Hiroshima) Japan. Serum concentrations of MK-7 were significantly higher in frequent natto eaters, and natto intake resulted in a marked, sustained increase in serum MK-7 concentration. We analyzed the relation between the regional difference in natto intake and fracture incidence. A statistically significant inverse correlation was found between incidence of hip fractures in women and natto consumption in each prefecture throughout Japan. These findings indicate that the large geographic difference in MK-7 levels may be ascribed, at least in part, to natto intake and suggest the possibility that higher MK-7 level resulting from natto consumption may contribute to the relatively lower fracture risk in Japanese women.

Aged↗
PubMed2001

Comparison of patient dose from imaging protocols for dental implant planning using conventional radiography and computed tomography.

OBJECTIVES: To compare the radiation doses from imaging protocols for dental implant planning either using conventional radiography only (dental panoramic radiography (DPR), cephalometry and linear cross-sectional tomography) or involving computed tomography (CT). METHODS: Organ absorbed doses were measured using a female Rando anthropomorphic phantom loaded with lithium fluoride thermoluminescent dosemeters (TLD). Standard mandibular protocols for dental implant planning were followed using either a conventional dental radiographic unit (PM 2002 CC Planmeca, Helsinki, Finland) or CT scanner (Excel Twin Elscint, Haifa, Israel). Organ absorbed and effective doses were calculated. Effective dose was calculated using two approaches, one based on the ICRP method which excludes the salivary tissue from the remainder organs (designated E(exc)), and the other with its inclusion (E(inc)). RESULTS: The greatest individual organ doses for any examination were measured in the salivary tissue. E(exc) for panoramic, cephalometric and cross-sectional tomography using DPR was 0.004 mSv, 0.002 mSv and 0.002 mSv, respectively, whereas with CT it was 0.314 mSv. The value of E(inc) calculated using these data was between two and five times E(exc). CONCLUSIONS: E(inc) greatly increases the apparent radiation burden, especially with high dose procedures. CT techniques can provide excellent images, but at the cost of increased radiation detriment. DPR with a cross-sectional tomography facility may give adequate clinical information at a greatly reduced dose.

Absorption↗
PubMed2001

Comparative study of maxillary complete dentures constructed of metal base and metal structure framework.

A removable denture designed using a three-dimensional cast metal framework (hereafter referred to as the 'structurally designed' denture) could extend denture longevity because it is unbreakable and easy to adjust. The aim of the present clinical study was to compare two types of maxillary removable dentures: conventional dentures and structurally designed denture. One edentulous and five partially dentate patients were fitted with two maxillary dentures made from the same impression and same occlusal relationship. About 20 days after delivery of the denture, masticatory analysis was conducted chewing phase (open, closed, and occluded); coefficients of variation and average variation were calculated. Denture vibration during tapping was then measured using an accelerometer. The patients were also interviewed about comfort, ease of chewing, speech, stability, aesthetics and preference for regular use. For both masticatory movements and denture vibration, there were no significant differences (P>0.1) between the conventional denture and the structural design denture. In evaluating the dentures according to each criteria, the significant superiority of one denture over the other could not be determined. However, all patients subjectively preferred the structurally designed dentures for regular use. According to these findings, structurally designed dentures do not appear to have any particular physiological problems as compared with the conventional dentures.

Acceleration↗
PubMed2001

Effective fluconazole therapy for liver transplant recipients during continuous hemodiafiltration.

Fungal infections are still one of the main causes of death and complications after solid organ and bone marrow transplants. The authors evaluated the effect of continuous hemodiafiltration (CHDF) on the pharmacokinetics of fluconazole in liver transplant recipients. Six liver transplant patients (primary biliary cirrhosis, n = 2; fulminant hepatitis, n = 2; viral hepatitis, n = 2) were enrolled in this study. In one patient not receiving CHDF, the fluconazole levels increased with increasing dosages. In contrast, in patients undergoing CHDF, the dosage of fluconazole was increased from 100 mg/d to 200 mg/d, but fluconazole did not reach the targeted levels. It appears that the targeted trough level cannot be achieved by administration of fluconazole at a dosage of 100 to 200 mg/d during CHDF. A higher dosage (600-1000 mg/d) of fluconazole may be required to achieve the therapeutic drug level in patients undergoing CHDF. In patients undergoing CHDF, fluconazole was given at a dosage of 800 mg/d and reached the targeted levels. In addition, after CHDF, the dosage of fluconazole was decreased to 100 mg/d, and fluconazole reached the near-targeted trough level. These results demonstrate that CHDF removes fluconazole from the blood at an efficiently high rate, resulting in its ineffective blood level. To guarantee safe and effective fluconazole therapy, the trough levels should be monitored routinely during CHDF.

Adult↗
PubMed2001

[The relationship between fall-related activity restriction and functional fitness in elderly women].

The purpose of this study was to assess the relationship between experiences of falls or fear of falling and functional fitness in the elderly. A total of 41 women, aged 66-88, who visited Fall Prevention Clinic in Tokyo Metropolitan Geriatric Hospital, underwent an interview and functional assessment. We used a questionnaire about falls, fear of falling, activity restriction, and twelve variables were used to assess functional fitness. Data were collected from June 2000 to November 2001. The subjects were classified into four subgroups: the faller group (n = 29) were subjects who had at least one or more experiences of falling accidents in the past one year; the non-faller group (n = 12) were subjects who did not have any falling accidents in the past one year; the activity restricted group (n = 12) were subjects who were restricted from going out because of fear of falling; the activity non-restricted group (n = 23) consisted of subjects who did not have any restriction concerning going out because of fear of falling. The results were: 1) Among all subjects, 85.4% had fear of falling. Among the subjects who had fear of falling. 34.3% had restricted outdoor activities due to the fear of falling. 2) Where 86.2% of the faller group responded that they had fear of falling. 83.3% of the non-faller group also responded as having fear of falling. Of the faller group, 44.0% had some restriction concerning going out because of fear of falling. In the non-faller group, 10.0% of them showed some restriction concerning going out because of fear of falling. The rate of activity restriction in the faller group was significantly higher (p < 0.05) than in the non-faller group. 3) The faller group had significantly reduced LNG with eyes open and closed, one-leg balance with eyes open, tandem walking, grip strength, and leg extension than the non-faller group. 4) The activity-restricted group exhibited significantly reduced one-leg balance with eyes open, Up & Go test, grip strength, and leg extension than the activity non-restricted group. In conclusion, lower leg strength and walking ability as well as history of falls are significant predictors of activity restriction in elderly women related to fear of falling.

Accidental Falls↗
PubMed2001

[Perspectives of post-genomic medical care in osteoporosis].

Osteoporosis is a multifactorial disease for which genetic and environmental factors are determinants. Recently, polymorphisms of many bone metabolism-related genes have been examined in the association study with bone mineral density and fracture incidence. Some showed significant correlation and others not. In addition, genome-wide QTL analysis was done using genome-wide random markers and showed some hot loci. However, the statistical power of each gene and locus are low and the genes to determine human bone mineral density have not been obtained. The accumulating information of genome science will help understand the pathogenesis of osteoporosis and find the useful ways for the prevention and the treatment of this disease.

Bone Density↗