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Biomedical subjects

T Sugimoto

Publications and source records attributed to T Sugimoto.

At least 109 records · Page 6Linked to original sources

Determinants of bone mineral density and spinal fracture risk in postmenopausal Japanese women.

The present study analyzed the factors that determine bone mineral density (BMD) and predict spinal fracture risk in postmenopausal Japanese women. Two hundred and five postmenopausal Japanese women aged 48-84 years (mean age 64 years) were enrolled in the cross-sectional study. BMD of the lumbar spine, femoral neck and total body as well as body composition were measured by dual-energy X-ray absorptiometry (DXA). Mid-radial BMD was measured by single-photon absorptiometry. We also determined serum levels of insulin-like growth factor (IGF)-I, IGF binding protein-2, -3 and osteocalcin as well as urinary levels of pyridinoline (Pyr), deoxy-Pyr (D-Pyr) and growth hormone. Multiple regression analysis revealed that lean body mass (LBM) was positively correlated with BMD at all sites. In contrast, femoral neck BMD was highly related to fat mass as well as LBM, although fat mass was not an independent correlate of total body and mid-radial BMD. LBM and urinary D-Pyr were crucial determinants at all sites except the mid-radius in stepwise regression analysis. Fat mass and serum IGF-I were determinants of femoral neck and mid-radial BMD, respectively. In terms of reproductive history, parity affected lumbar BMD. Factors affecting BMD differed according to the site. On the other hand, lumbar BMD as well as serum levels of IGF-I and albumin were selected as predictors of spinal fracture risk in multiple logistic regression analysis. Lumbar BMD, serum IGF-I and LBM were selected in women with lumbar BMD above 0.727 g/cm2. In conclusion, the present study indicates that LBM is a more important determinant of BMD than fat mass at any site except the femoral neck. Age, serum IGF-I and urinary D-Pyr were also determinants of BMD, dependent on the regions measured. Lumbar BMD and LBM as well as serum levels of IGF-I and albumin were useful markers which predicted the risk of osteoporotic spinal fractures in postmenopausal Japanese women.

Absorptiometry, Photon↗

Intracystic carcinoma of the male breast: report of a case.

We experienced a very rare case of male intracystic breast carcinoma. A 66-year-old man presented at our hospital because of a palpable mass in his right breast. The imaging diagnosis was an intracystic carcinoma with hemorrhagic fluid and two mural nodules. Modified radical mastectomy was performed under general anesthesia. The pathological examination revealed the intracystic papillary carcinoma with foci of microinvasion. The findings of power Doppler ultrasonography and dynamic magnetic resonance imaging were very useful for the differential diagnosis of our case.

Aged↗

Expression and distribution of beta amyloid precursor protein and beta amyloid peptide in reactive astrocytes after transient middle cerebral artery occlusion.

BACKGROUND: In the brains of Alzheimer's disease patients, beta amyloid protein is the major component of senile plaque. In ischemic stress, beta amyloid precursor protein (APP) and beta amyloid peptide are reported to be upregulated. METHOD: Using Male Wistar-ST rats, expression and distribution of APP and beta amyloid peptide were examined immunohistochemically after transient ischemia induced by a 2-h middle cerebral artery occlusion (MCAO). After reperfusion for 3, 7, 14, 30 and 60 days, brains were removed and immunostaining was performed. FINDINGS: The reactive astrocytes with APP were observed in the periphery of infarct from 3 days to 60 days post-occlusion. The immunoreactivity of beta amyloid peptide was also localized in the reactive astrocytes in the peripheral zone of infarct at 7, 14, and 30 days post-occlusion. However, beta amyloid expression was not identified at 3 days or 60 days post MCAO. Transient ischemia temporarily induced beta amyloid peptide expression in reactive astrocytes, but this expression peaked at 30 days and disappeared at 60 days. INTERPRETATION: These findings suggested that beta amyloid peptide was derived from the processing of APP produced in the same reactive astrocytes and the production of the peptide stopped within 60 days after the ischemic stress.

Alzheimer Disease↗

Effect of sodium thiosulfate on cisplatin removal with complete hepatic venous isolation and extracorporeal charcoal hemoperfusion: a pharmacokinetic evaluation.

BACKGROUND: Complete hepatic venous isolation and extracorporeal charcoal hemoperfusion (HVI.CHP) can limit systemic exposure to high-dose chemotherapeutic agents when given by hepatic arterial infusion (HAI). The purpose of this study was to determine if the concomitant use of sodium thiosulfate (STS) could further expand the advantages of pharmacologic delivery of HVI.CHP for cisplatin (CDDP) during HAI chemotherapy. METHODS: CDDP (4mg/kg) was administered over 20 minutes via HAI under conditions of HVI.CHP in 14 mongrel dogs. HVI.CHP was performed for 30 minutes after initiation of HAI. During CDDP infusion, 7 dogs each received 400 mg/kg STS (a 100-fold molar ratio to CDDP) over 20 minutes via the prefilter (STS group) circuit line, while the remaining 7 dogs (controls) received no STS. Blood samples were taken serially from the prefilter circuit line (hepatic venous blood), postfilter line, and the left carotid artery (systemic blood). The free and total CDDP concentrations in these samples were determined by flameless atomic absorption spectrophotometry. RESULTS: During 20 minutes HAI of CDDP, the mean CDDP extraction ratios (ER) by CHP filter were always higher in the STS group than in the control group, regardless of the form (free or total) of CDDP. The differences between the STS and control groups in the extraction ratios of free and total CDDP were significant at all time points measured (P < .05). Consequently, systemic exposure to CDDP, as assessed by area under the time-concentration curve of total CDDP, was significantly lower in the STS group than in the control group (P < .05). CONCLUSIONS: These results indicated that concomitant STS infusion could further increase the effect of HVI.CHP on CDDP removal after HAI.

Animals↗

A serine endopeptidase from cucumber leaves is inhibited by L-arginine, guanidino compounds and divalent cations.

An endopeptidase was purified and characterized from green leaves of cucumber (Cucumis sativus L. suyo). The purified enzyme, a basic amino acid-specific endopeptidase with a pI of 5.0, was a monomeric protein of 80 kDa whose pH optimum was 9.5. Inhibitor analysis suggested that it was a serine endopeptidase and contained sulfhydryl groups essential for catalytic activity. Analysis of internal amino acid sequences of the endopeptidase showed no significant similarity to other proteins. Its activity was inhibited by L-Arg and guanidino compounds having high hydrophobicity, as well as divalent cations such as Mg2+ and Ca2+. The K(i) values of L-Arg and Mg2+, which are also likely in vivo inhibitors, were 3.5 and 10 mM, respectively. Inhibition by L-Arg and Mg2+ was additive, and more than 70% of the activity was reversibly inhibited under their physiologically significant concentrations. These results suggest that the enzyme is possibly regulated by L-Arg and/or guanidino compounds, and by divalent cations in vivo.

Agmatine↗

Analysis of PTEN/MMAC1 alteration in neuroblastoma.

Neuroblastoma is the most common extracranial solid tumor in children. Although it has been reported that loss of heterozygosity at various loci, including 10q, frequently occurs in neuroblastoma, a bona fide tumor suppressor gene has not been identified. Recently, a gene mapped to chromosome 10q23, PTEN/MMAC1, was identified as a tumor suppressor gene that inhibits cell survival and cell proliferation by catalyzing the dephosphorylation of phosphatidylinositol 3,4,5-triphosphate. To screen for mutations of this gene in neuroblastoma, we analyzed 11 primary neuroblastoma tumors and 16 neuroblastoma cell lines for PTEN/MMAC1 mutations and deletions. All nine exons of the PTEN/MMAC1 gene were examined using the polymerase chain reaction-single strand conformational polymorphism assay and sequencing. Only one of the cell lines showed a mutation, a 1-bp frameshift deletion in exon 7, and an allelic loss in the opposite allele was revealed by a microsatellite analysis. Our results indicate that the disruption of the PTEN/MMAC1 gene is not a frequent event in neuroblastoma, and suggest that this disruption may be responsible for malignant progression in only a limited proportion of cases of neuroblastoma.

Alleles↗

LC determination of Z-338, novel gastroprokinetic agent in dog plasma by SCX solid phase extraction.

A simple high-performance liquid chromatographic assay with using UV detection (266 nm) was developed to determine a novel gastroprokinetic agent, Z-338 in dog plasma. The extraction procedure using solid-phase extraction with a Isolute SCX column produces extremely clean eluates and a high recovery. Intra- and inter-day variabilities were lower than 5%. The limit of quantitation of the method was 2.5 ng/ml. This assay was applied to the monitoring of Z-338 concentrations in dogs after oral administration. The method also appeared rapid, simple and suitable for therapeutic Z-338 monitoring.

Animals↗

2'-O,4'-C-Methylene bridged nucleic acid (2',4'-BNA): synthesis and triplex-forming properties.

For development of ideal antisense and antigene molecules, various chemical modifications of oligonucleotides have been studied. However, despite their importance, there is only limited information available on the triplex-forming ability of the conformationally restricted or locked oligonucleotides. We report herein that 2'-O,4'-C-methylene bridged nucleic acid (2',4'-BNA) modification of triplex-forming oligonucleotide (TFO) significantly enhances the binding affinity towards target dsDNA. On Tm measurements, the triplex with the 2',4'-BNA oligonucleotides were found to be stabilized with deltaTm/modification of +4.3 to +5 degrees C at pH 6.6 compared to the triplexes with the unmodified oligonucleotide. By means of gel-retardation assay, the binding constant of the 2',4'-BNA oligonucleotide at pH 7.0 was at least 300-fold higher than that of the natural oligonucleotide. In addition, the 2',4'-BNA oligonucleotide clearly showed the inhibition of the NF-kappaB transcription factor (p50)-target dsDNA binding by forming a stable triplex at pH 7.0.

Bridged Bicyclo Compounds, Heterocyclic↗

Primary leptomeningeal lymphoma.

Primary leptomeningeal lymphoma is a rare disorder, and the neuroradiological characteristics or the complication of this rare disorder have not been well reported. We reported herein a patient with a primary leptomeningeal lymphoma who has complication with subdural hematoma. The patient complained of headache and vomiting. Neurological examination revealed progressive cranial nerve palsy. Cerebrospinal fluid examination disclosed monoclonal proliferation of atypical B-lymphocytes. Cranial computed tomographic scans showed a left frontal mass with convex form to the brain parenchyma. T1-weighted magnetic resonance (MR) images disclosed subacute subdural hematoma. However, proton-weighted MR images showed high signal intensity in subarachnoid space, which suggested leptomeningeal lymphoma. He underwent craniotomy, and the diagnosis of leptomeningeal lymphoma complicated with subdural hematoma was confirmed. Systemic examinations disclosed no lymphomatous lesions except for leptomeningus, and the diagnosis of primary leptomeningeal lymphoma was established. We suggested that subdural hematoma was associated with primary leptomeningeal lymphoma in this patient. Cerebrospinal fluid examination and proton-weighted MR imaging should be performed when progressive neurological abnormalities are found in patients with subdural hematoma.

Aged↗

Kinetic analysis of cytokine gene expression in patients with GVHD after donor lymphocyte infusion.

Patients who receive a donor lymphocyte infusion (DLI) for the treatment of relapsed leukemia after allogeneic BMT (alloBMT) often developed GVHD. To determine whether cytokines might have a role in GVHD, an intensive kinetic analysis of in vivo cytokine gene expression was performed on PBMC from three such patients. Expression of IL-1beta, IL-2, IFN-gamma, IL-4, IL-5, IL-8, IL-10, IL-12, TNF-alpha, and IL-2Ralpha was examined using a sensitive semi-quantitative reverse transcription (RT)-PCR assay system. Six normal controls were also analyzed for comparison. Expression of type 1 T helper (Th1) cytokines, IL-2 and IFN-gamma was greatly increased in all three patients. In particular, the changes in IL-2 gene expression correlated well with disease progression, suggesting that IL-2 has a critical role in the development of GVHD. Although the pattern of type 2 T helper (Th2) cytokine gene expression differed in each patient, the expression of IL-4 was inversely related to expression of Th1 cytokines. These results suggest that Th1 dominates in the development of human clinical GVHD.

Adult↗

Bone metabolism and body composition in Japanese patients with active acromegaly.

OBJECTIVE: Skeletal involvement is a common clinical feature in acromegalic patients. Although several recent reports are available concerning bone mineral density (BMD) in acromegaly, the controversy still exists as to whether BMD of acromegalic patients is increased or not. The present study was performed to examine biochemical bone metabolic indices and BMD as well as body composition in 26 Japanese patients with active acromegaly and 26 control subjects matched for age, sex, race and height in a cross-sectional study. MEASUREMENTS: BMD of the lumbar spine and femoral neck, as well as body composition, was measured by dual-energy X-ray absorptiometry. Mid-radial BMD was measured by single-photon absorptiometry. We also determined serum levels of IGF-I, IGFBP-3 and osteocalcin (OC) as well as urinary levels of deoxy-pyridinoline (D-Pyr) and CrossLaps. RESULTS: Percent lean body mass was increased and percent fat mass was decreased in the acromegalic patients compared to control subjects. Serum levels of OC, as well as urinary levels of D-Pyr and CrossLaps, were significantly higher in acromegalic patients compared to control subjects (9.8 +/- 1.2 vs. 5.7 +/- 0.77 for OC; 11.8 +/- 1.66 vs. 5.0 +/- 0.49 for D-Pyr; 437.6 +/- 68.4 vs. 156.5 +/- 39.6 for CrossLaps). Z scores of BMD at mid-radius as well as lumbar spine and femoral neck were significantly higher in acromegalic patients compared to control subjects (1.086 +/- 0.311 vs. -0.060 +/- 0.274 for mid-radius; 1.022 +/- 0.280 vs. 0.319 +/- 0.165 for lumbar spine; 1.292 +/- 0.347 vs. 0.232 +/- 0.264 for femoral neck). CONCLUSIONS: The present study revealed that a decrease in percent fat mass and an increase in percent lean body mass were observed in Japanese patients with active acromegaly. Bone mineral density at all sites and bone metabolic markers were also increased in acromegaly. The present findings provide additional evidence that the GH/IGF-I axis might play an important role in the maintenance of bone mass as well as the regulation of body composition in Japanese adults.

Absorptiometry, Photon↗

Association of polymorphic alleles of the calcium-sensing receptor gene with the clinical severity of primary hyperparathyroidism.

OBJECTIVE: Primary hyperparathyroidism (pHPT) is a heterogeneous disease in its clinical course and severity. Previous studies have suggested an association between the clinical severity of pHPT and the genotypes of vitamin D receptor, oestrogen receptors and PTH molecules. The Ca-sensing receptor (CaR) is activated by an extracellular calcium ion and controls PTH secretion, and thus polymorphisms of CaR might be associated with the magnitude of PTH secretion and the clinical severity of pHPT. In this study, we examined the relationship between CaR polymorphisms and biochemical markers in pHPT patients. METHODS: We analysed 105 Japanese pHPT patients (85 females and 20 males; mean age 55.6 +/- 14.0 years). We determined the CaR genotypes of G990R and intron 5 polymorphisms with genomic DNA extracted from peripheral lymphocytes. The intron 5 polymorphism was defined as T/T, T/C and C/C. RESULTS: In the G990R polymorphism, serum levels of both intact PTH and alkaline phosphatase (ALP) were significantly higher and the serum level of phosphorus was significantly lower in the RR group than in the GG group. In the intron 5 polymorphism, the T/T group showed significantly lower serum levels of intact PTH and Ca. Furthermore, patients with both the codon 990 RR and the intron 5 C allele (the RRC(+) group) had significantly higher serum levels of intact PTH and ALP than did the other patients. CONCLUSIONS: The present study is the first to show that CaR polymorphisms of G990R and intron 5 were closely associated with the magnitude of PTH secretion and/or PTH degradation as well as the clinical severity in pHPT patients.

Adolescent↗

Plasma leptin concentrations are associated with bone mineral density and the presence of vertebral fractures in postmenopausal women.

OBJECTIVE: Although total fat body mass (FM) is considered to be one of the major determinants of bone mass, the mechanism by which FM and bone mass are positively correlated remains unclear. Leptin, the product of the obese (ob) gene, is secreted from adipocytes and its plasma levels are known to be positively correlated with %fat (FM divided by total body weight). There is recent evidence suggesting that leptin directly stimulates osteoblastic differentiation. Thus it is possible that the anabolic action of this hormone on bone may participate in the positive correlation between FM and bone mass. In this study, we analysed the relationships between either plasma leptin levels or %fat vs. bone mineral density (BMD) values as well as the presence of vertebral compression fractures, and evaluated whether or not plasma leptin levels were associated with BMD or bone fragility in a manner independent of FM. PATIENTS: One hundred and thirty-nine postmenopausal women (age 48-78 years, mean 62.5), who visited our outpatient clinic for the evaluation of osteoporosis. DESIGN AND MEASUREMENTS: Plasma concentrations of leptin after an overnight fast were measured by radioimmunoassay. BMD values were measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine, femoral neck and whole body. Distal one-third of radius BMD was measured by single photon absorptiometry (SPA). Vertebral fractures were assessed by lateral thoracic and lumbar spine radiographs. RESULTS: Although neither plasma leptin levels nor %fat correlated with age, there was a significant positive correlation between plasma leptin levels and %fat (r = 0.563, P < 0.001). Plasma leptin levels were significantly and positively correlated with BMD values at all skeleton sites measured, and multiple regression analysis revealed that this positive relationship was still observed with BMD values of the femoral neck and of the whole body, even after %fat and age were taken into account. Moreover, plasma leptin levels but not %fat were significantly lower in women with vertebral fractures than in those without fractures. When multiple logistic regression analysis was performed with either plasma leptin value or %fat employed as independent variables, plasma leptin values but not %fat were selected as an index affecting the presence of vertebral fractures. CONCLUSION: Our study showed that plasma leptin levels but not %fat are associated with BMD and the presence of vertebral fractures in postmenopausal women, suggesting that circulating leptin might play a physiological role in maintaining bone mass as well as better bone quality.

Adipose Tissue↗

Effect of temperature on serum protein binding characteristics of phenytoin in monotherapy paediatric patients with epilepsy.

OBJECTIVES: To determine the effects of temperature on binding characteristics of phenytoin to serum proteins in paediatric patients with epilepsy. METHOD: Serum samples examined in the study were obtained from 41 paediatric patients (23 male, 18 female) with epilepsy on phenytoin monotherapy. Their age ranged from 1 to 15 years (mean +/- SD, 10;2 +/- 4;0 years). Protein binding of phenytoin was evaluated by ultrafiltration under current laboratory routine conditions (25 +/- 3 degrees C) or at a temperature of 37 degrees C. The in vivo binding parameters of phenytoin to serum proteins were determined using a binding equation derived from the Scatchard equation for a one-site binding model. RESULTS: Significant differences were observed in serum concentrations of unbound phenytoin at the two temperatures (P < 0;05). The mean association constant L/micromol (K) of phenytoin to serum proteins is 0.016 L/micromol at 25 +/- 3 degrees C and 0;009 L/micromol at 37 degrees C, while mean total concentration of binding sites (n(Pt)) seems to be similar between the two temperatures (682 micromol/L for 25 +/- 3 degrees C and 746 micromol/L for 37 degrees C). Significant differences were observed in binding characteristics of phenytoin to serum proteins for the different temperature conditions of ultrafiltration (P < 0;05). CONCLUSION: Our study confirms that binding affinity for phenytoin-serum protein interaction is approximately 44% lower at 37 degrees C than at 25 +/- 3 degrees C and consequently, binding potential (K.n(Pt)) is approximately 38% lower at 37 degrees C than at 25 +/- 3 degrees C.

Adolescent↗

Accelerated DNA fragmentation of the denture-bearing mucosal epithelium in an animal model of diabetes.

This study examined the effect of masticatory pressure transmitted directly to the hard palate mucosa on the final stage of terminal differentiation of keratinizing system of rats with and without streptozotocin-induced diabetes mellitus. In the nondiabetic rats with masticatory pressure, the number of terminal-deoxynucleotidyl-transferase-mediated deoxyuridine-triphospate-biotin nick end labelling (TUNEL) positive cells tended to increase about twice as much as in the nondiabetic rats without pressure with and without denture. A similar tendency of increase was observed in the diabetic rats without pressure. The synergy of the mechanical pressure and diabetic condition for 2 weeks greatly accelerated the DNA fragmentation, showing 8-fold increase in TUNEL positive cells over the normal control, and caused exfoliation of the stratum corneum. A 4-week exposure of diabetics to the masticatory pressure induced laminar splitting in the midst of the spinosum. Some cells in the stratum granulosum exhibited a sign of DNA fragmentation when laminar splitting took place in the vital cell layer. Premature DNA fragmentation may disturb the adhesion between spinosum cells and prevent the maturation of stratum corneum. Increase in Bax protein-like immunoreactivity in these epithelial cells as revealed by immunocytochemistry may underlie the premature DNA fragmentation in the oral masticatory epithelium under pressure in diabetic patients.

Animals↗

Malignant phyllodes tumor of the breast with expression of osteonectin and vinculin.

Phyllodes tumor is a very rare neoplasm which accounts for 2.5% of all fibroepithelial lesions of the breast. The mesenchymal component of a malignant phyllodes tumor frequently contains heterologous components. We report a case of malignant phyllodes tumor. The patient was a 40-year-old woman with a lump on the left breast. Histological examination revealed the lump to be a malignant phyllodes tumor with foci of liposarcomatous differentiation. The mesenchymal tumor cells, including those in the liposarcomatous components, were found to express vimentin, osteonectin and vinculin. However, they showed no immunoreaction to CAM 5.2, desmin, alpha-smooth muscle actin (ASMA), neuron-specific enolase (NSE) nor S-100. Ultrastructurally, the mesenchymal tumor cells were found to have abundant cytoplasmic organelles, but there was no evidence showing their differentiation to myofibroblasts. Further studies will be necessary to elucidate the significance of vinculin and osteonectin expression in malignant phyllodes tumor.

Adult↗

Dinucleotide repeat polymorphism of matrix metalloproteinase-9 gene is associated with diabetic nephropathy.

BACKGROUND: Although genetic susceptibility has been proposed as an important factor for the development and progression of diabetic nephropathy, the definitive gene has not been identified. To identify the genetic marker for diabetic nephropathy, we examined the association between the (A-C)n dinucleotide repeat polymorphism upstream of the matrix metalloproteinase-9 (MMP-9) gene and diabetic nephropathy in a group of Japanese patients with type 2 diabetes. METHODS: Patients were divided into three groups based on their urinary albumin excretion rate (AER) and the stage of diabetic retinopathy as follows: uncomplicated group (U), normal albuminuria (AER <20 microg/min) without proliferative retinopathy and with the duration of diabetes more than 20 years (N = 32); microalbuminuria group (M), 20 < or = AER < 200 microg/min (N = 155); overt nephropathy group (O), AER > or = 200 microg/min (N = 63). The region containing the dinucleotide repeat upstream of MMP-9 gene was amplified by polymerase chain reaction (PCR). The amplified products were analyzed with 7% formamide/urea acrylamide gel electrophoresis. The promoter constructs of the MMP-9 gene were transfected with the CMV-beta-galactosidase construct into 293 cells using the liposome method. Twenty-four hours after transfection, cells were harvested, and luciferase and beta-galactosidase activities were measured. RESULTS: Nine alleles of the dinucleotide repeat polymorphism (17 to 25 repeats) were identified, and the frequency of each allele in diabetic subjects was not different from that in nondiabetic controls. The frequency of the allele containing 21 repeats (A21) was most abundant (42.4% in control and 45.6% in diabetic subjects), followed by the allele with 23 repeats (A23; 35.4% in control and 27.6% in diabetic subjects). The A21 allele was less frequent in M and O than U (O, 38.9%; M, 45.5%; U, 59.3%, chi2 = 7.18; P < 0.05, O vs. U), while the frequency of the alleles other than A21 was not different among each group. The calculated odds ratio for nephropathy in the noncarrier, heterozygote, or homozygote of A21 allele was 3.38, 1.97, and 0.2, respectively. Furthermore, the promoter assay for the MMP-9 gene revealed that the A21 allele had a higher promoter activity compared with other alleles. No significant correlation was observed between serum MMP-9 concentrations and the MMP-9 gene polymorphism. CONCLUSION: These results indicate that the patients with A21 allele of the MMP-9 gene may be protected from the development and progression of diabetic nephropathy. Thus, the microsatellite polymorphism upstream of the MMP-9 gene could be a useful genetic marker for diabetic nephropathy.

Aged↗