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Biomedical subjects

T Hayashi

Publications and source records attributed to T Hayashi.

At least 469 records · Page 26Linked to original sources
PubMed2000

Estriol (E3) replacement improves endothelial function and bone mineral density in very elderly women.

We investigated the effects of estriol (E3) on endothelial function and bone mineral density (BMD) in very elderly women. Twenty-four very elderly women (80 +/- 3.5 years old) were administered CaCl2 with or without estriol treatment (2 mg/day) for 30 weeks (hormone replacement treatment [HRT] group vs control group). Endothelium-dependent flow-mediated dilatation (FMD), endothelium-independent dilatation by nitroglycerin of the brachial artery, and BMD were assessed. Levels of plasma lipids and apoproteins were not changed; however, both plasma E3 and E2 were substantially increased (E2, 4.6 to 31.3 +/- 8.1; E3, <5 to 45.3 +/- 7.9 pg/mL) by HRT. The FMD value was also increased by HRT, as were the plasma nitrite/nitrate and cGMP values. The response to nitroglycerin was not changed. The BMD was increased by HRT, but decreased in the control group. There were significant differences between the HRT group and control group after 30 weeks' treatment in the levels of osteocalcin, P1CP, and urinary deoxypiridinoridine. E3 significantly improved BMD by inhibiting bone resorption. Endothelial function was improved in line with the antiatherosclerotic effects. E3 might be effective for use in HRT in elderly patients.

Aged↗
PubMed2000

Evaluation of (1R,2R)-1-(5'-methylfur-3'-yl)propane-1,2,3-triol, a sphydrofuran derivative isolated from a Streptomyces species, as an anti-herpesvirus drug.

(1R,2R)-1-(5'-Methylfur-3'-yl)propane-1,2,3-triol (MFPT), a stable anhydro derivative of sphydrofuran, was obtained from the culture broth of STREPTOMYCES: sp. strain FV60 as an inhibitor of herpes simplex virus type 1 (HSV-1). The compound showed antiherpetic activity with a 50% inhibitory concentration of 1.2 IM in an in vitro assay system. Although the binding of virus to host cells was not inhibited, the penetration of virus into cells was moderately blocked by MFPT. Some of the viruses, once they had penetrated cells, failed to form plaques in the presence of MFPT. When added to the late stages of HSV-1 replication, MFPT also inhibited virus production. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis of isotope-labelled HSV-specific proteins revealed that a protein or proteins with reduced molecular weight (about 120 kDa) was clearly detected in cells treated with MFPT. Western blot analysis with antibodies against three HSV-specific glycoproteins (gB, gC and gD) showed a significant difference in gC synthesis between untreated and MFPT-treated cells. Release of progeny viruses was suppressed by MFPT. Syncytium formation by HSV-1 strain HF was inhibited and small plaques with rounded cells were formed in MFPT-treated cell cultures. When wild-type HSV-1 was serially propagated under the selective pressure of MFPT, resistant virus emerged. MFPT-resistant progeny were accompanied by the formation of plaques with rounded cells. These results, taken together, suggest that MFPT might act by limiting the maturation of HSV-specific glycoproteins, particularly of HSV-1 gC.

Adsorption↗
PubMed2000

Preoperative concurrent chemoradiotherapy against muscle-invasive bladder cancer: results of partial cystectomy in elderly or high-risk patients.

BACKGROUND: Good local control has been reported in cases of muscle-invasive bladder cancer treated by chemoradiotherapy and transurethral resection (TUR). However, definitive irradiation or extensive chemotherapy is often intolerable for elderly or poor-risk patients. We report here benefits of partial cystectomy after concurrent low-dose chemoradiotherapy for high-risk patients. METHODS: Thirty-seven patients with localized muscle-invasive bladder cancer (T2-T4) were treated with concurrent cisplatin (50-100 mg/body x 2 courses) and pelvic irradiation (40 Gy) preoperatively. Among 17 patients (46%) who achieved complete response (CR), 10 were not suitable for radical cystectomy and underwent partial cystectomy. Radical cystectomy was performed in 24 cases [CR = 6, partial response (PR) = 18]. Two patients (one CR and one PR) rejected open surgery and were treated by TUR of the primary site. One no change (NC) patient received no further treatment because of mental disorder. RESULTS: Median follow-up was 12 months (range 2-37 months). Fifteen of 36 evaluable cases (42%) achieved a pathological T0 response (no residual tumor). Estimated 3-year disease-free survival was 56% for all patients and 100% for T0 responders. Seven of 21 patients with pathological persistent tumor developed local recurrence (three patients) or distant metastasis (four patients). All of the 10 patients (eight with T0 response and two with a small residual tumor nest) who underwent partial cystectomy were recurrence-free for an observation period of up to 3 years. CONCLUSIONS: Bladder preservation by partial cystectomy may be a choice for patients who show a good response to preoperative chemoradiotherapy and are not suitable for radical cystectomy.

Aged↗
PubMed2000

Microstructures in CoPtC magnetic thin films studied by superpositioning of micro-electron diffraction

Cross-sectional transmission electron microscopy observation of CoPtC thin films showed that 10 nm sized ultrafine particles of CoPt typically were elongated along the substrate normal. Analysis of the superposition of 40 micro-electron diffraction patterns showed that there was no preferred crystal orientation of CoPt particles. This superpositioning technique can be applied to thin films, whose X-ray diffraction analysis is difficult due to the small size of the crystals.

Journal Article↗
PubMed2000

Isolation and characterization of a 60 kDa 2,4-D-binding protein from the shoot apices of peach trees (Prunus persica L.); it is a homologue of protein disulfide isomerase.

To obtain a candidate auxin-binding protein (ABP), a soluble 60 kDa protein was isolated from an extract of shoot apices of peach trees (Prunus persica L.) by affinity chromatography on a 2,4-dichlorophenoxyacetic acid (2,4-D)-linked Sepharose4B column. The 60 kDa polypeptide, designated Pp60, was purified as a single band on SDS-PAGE by column chromatography. Its dissociation constant (Kd) for [14C]-2,4-D was calculated to be 3.5 x 10(-5) M. The binding of Pp60 for [14C]-2,4-D was inhibited by naphthalene-1-acetic acid (NAA) and p-chlorophenoxyisobutyric acid (PCIB) as well as 2,4-D. Indole-3-acetic acid (IAA) had little effect on the binding. These results suggested that Pp60 is a protein that has an affinity for 2,4-D, NAA, and PCIB in vitro. The partial amino acid sequences of Pp60 showed high homology to those of protein disulfide isomerase (EC 5.3.4.1). Immunoblot analysis demonstrated that Pp60 exists ubiquitously in shoots and leaves. In fruit, expression of Pp60 is restricted at an early stage of development.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2000

Sexual dimorphism in the regulation of meiotic process in the rabbit.

Meiosis, mitosis, and apoptosis during fetal and postnatal periods were investigated in order to explore mechanisms of sexual dimorphism in initiation of germ cell meiosis. Gonads were obtained from Japanese white rabbits from 23 to 51 days postcoitum (dpc). Gonadal thin sections were stained with hematoxylin and eosin. Germ cell alkaline phosphatase and apoptosis were detected with histochemical and immunohistochemical methods, respectively. In the ovary, meiotic germ cells were initially recognized at 29 dpc and arrested after enclosure within follicles. Similarly, meiotic germ cells were recognized outside seminiferous tubules at 29 dpc, but no meiotic figures were identified in intratubular spaces. Apoptotic germ cells were not recognized in the intratubular spaces before 35 dpc, and no apoptotic figures were recognized in the ovary during the period studied. In conclusion, the initiation of meiosis in testicular interstitial tissue at the time comparable to that in the ovary indicates that germ cells of both sexes have the ability to enter meiosis during the same stage of fetal development; and it appears most likely that delayed initiation of meiosis in the intratubular space is attributable to meiosis-inhibiting substance(s) present in seminiferous tubules.

Animals↗
PubMed2000

Idiopathic adrenal hemorrhage.

A case of idiopathic adrenal hemorrhage is reported. A 76-year-old woman exhibited a left adrenal tumor, 3 cm in diameter, on abdominal computed tomography. The patient was receiving aspirin medication for atrial fibrillation. There was no evidence of increased adrenal hormones. The mass enlarged to 6 cm in diameter within 18 months, and malignancy was suspected. The mass was diagnosed as adrenal hematoma by operative findings.

Adrenal Gland Diseases↗
PubMed2000

A clinicopathologic study of 100 cases of pulmonary sclerosing hemangioma with immunohistochemical studies: TTF-1 is expressed in both round and surface cells, suggesting an origin from primitive respiratory epithelium.

Pulmonary sclerosing hemangioma (SH) is a lung neoplasm of uncertain histogenesis that is composed of two major cell types: surface and round cells. The authors studied 100 cases of pulmonary SH that presented as a peripheral (95%), solitary (96%) mass of less than 3 cm in diameter (74%) in asymptomatic patients who were mostly women (83%) with a mean age of 46.2 years. Immunohistochemistry of multiple epithelial, mesothelial, pneumocyte, neuroendocrine, and mesenchymal markers was performed on 47 cases to investigate the histogenesis of this neoplasm. Both surface and round cells stained with epithelial membrane antigen (EMA) and thyroid transcription factor-1 (TTF-1) in more than 90% of cases; however, the round cells were uniformly negative for pancytokeratin and positive for cytokeratin-7 and CAM 5.2 in only 31% and 17% of cases, respectively. Surfactant proteins A and B as well as Clara cell antigen were positive in varying numbers of surface cells but they were negative in the round cells. Neuroendocrine cells either as isolated scattered cells or as a tumorlet within the center of SH were detected (chromogranin, Leu-7, synaptophysin positive) in three cases. The expression of TTF-1 in the absence of surfactant proteins A and B and Clara cell antigens in the round cells of SH suggests that they are derived from primitive respiratory epithelium. The alveolar pneumocytes and neuroendocrine cells may either represent phenotypic differentiation of a primitive respiratory epithelial component or they may correspond to non-neoplastic entrapped or hyperplastic elements. The concomitant positivity of both cell types in SH for TTF-1 and EMA, and the negativity of round cells for pancytokeratin and neuroendocrine markers, provide useful clues not only for histogenesis but also for the diagnosis of this lung neoplasm.

Adolescent↗
PubMed2000

Pulmonary and mediastinal glomus tumors--report of five cases including a pulmonary glomangiosarcoma: a clinicopathologic study with literature review.

Pulmonary and mediastinal glomus tumors are rare lesions, with four previously reported primary pulmonary cases and three mediastinal cases. The authors report one mediastinal glomus tumor, a locally infiltrative type, and four pulmonary glomus tumors, including the first case of primary pulmonary glomangiosarcoma. These tumors show a variety of clinical and pathologic differences from the more common cutaneous variety, including later age at presentation, larger size, and more frequent atypical/malignant features. Mediastinal and pulmonary glomus tumors both have an average patient age at presentation of 45 years. However, compared with their pulmonary counterparts, mediastinal glomus tumors are less common, more often symptomatic, and are larger (average size, 5.4 cm). Additionally, mediastinal glomus tumors more often demonstrate malignant or atypical features. Pulmonary glomus tumors average 3.3 cm in greatest dimension, with the majority measuring less than 2.5 cm. The pulmonary glomangiosarcoma presented was large, measuring 9.5 cm, and showed increased mitotic count (9 mitoses/10 high-power fields), necrosis, cytologic atypia, and was associated with disseminated disease. Regardless of clinical symptoms, histologic features, and even metastases, the vast majority of all benign and malignant glomus tumors are indolent and cured surgically, with adjuvant therapy needed only for occasional patients with more advanced disease. The four patients with glomus tumors reported are currently alive and free of disease as of last follow up. The patient with the glomangiosarcoma developed widespread metastases and died of disease 68 weeks after initial therapy.

Adult↗
PubMed2000

A case of dermatomyositis associated with mechanic's hand.

A 67-year-old man was referred to the Department of Internal Medicine at Tokyo Medical University with interstitial pneumonia in July 1999. He presented with keratotic plaques on both palsm and on the ventral and lateral sides of his fingers. Erythematous keratosis was observed on the dosal aspect of his fingers and metatarsophalangeal (MP) joints. Edematous erythema was seen on the patient's chest, back, and the extensor surfaces of his arms. Electromyography revealed a myogenic pattern and an increased level of myogenic enzymes was found in the blood. Histological findings of the ventral sides of his fingers showed hyperkeratosis and parakeratosis of the dermal tissue and liquefaction degeneration of the basal layer at the papilla. Based on these findings, the patient was given a diagnosis of dermatomyositis associated with mechanic's hand. A systemic examination confirmed interstitial pneumonia and carcinoma of the duodenal papilla. Mechanic's hand is a type of dermatitis associated with myopathy first reported by Stahl et al. in patients with collagen disease. We report herein the first documented case of mechanic's hand in Asians.

Adenocarcinoma↗
PubMed2000

Molecular analysis of the folC gene of Pseudomonas aeruginosa.

We have cloned the Pseudomonas aeruginosa folC gene coding for folylpolyglutamate synthetase-dihydrofolate synthetase, which was located between the trpF and purF loci, and determined the nucleotide sequence of the folC gene and its flanking region. The deduced amino acid sequence of P. aeruginosa FolC was highly homologous to that of Escherichia coli FolC. The cloned gene complemented E. coli folC mutations and was found to encode both folylpolyglutamate synthetase and dihydrofolate synthetase activities. The gene organization around the folC gene in P. aeruginosa was completely conserved with that in E. coli; the accD gene was located upstream of the folC gene, and dedD, cvpA and purF genes followed the folC gene in this order. The gene arrangement and the result of the promoter activity assay suggested that the P. aeruginosa accD and folC genes were co-transcribed.

Acetyl-CoA Carboxylase↗
PubMed2000

Direct discrimination and full-day disclosure of ventricular parasystole on new heart rate tachograms.

INTRODUCTION: To discriminate ventricular parasystole from fixed coupling interval ventricular premature complexes (VPCs), we developed a new diagnostic method using a dot distribution pattern corresponding to VPCs recorded on a heart rate tachogram using ambulatory ECG monitoring data. We tested our hypothesis that widely scattered VPC dots on instantaneous heart rate tachograms indicate a constant VPC-VPC interval compatible with parasystole. METHODS AND RESULTS: Patients with frequent VPCs > 5,000/day) were divided into two groups depending on the tachogram dot distribution patterns: group S (n = 10, aged 61 +/- 16 years) showed widely scattered VPC dot distribution, whereas group F (n = 10, 60 +/- 17 years) showed fixed VPC dot distribution limited to a narrow zone. Using digitized R-R interval data, full-day heart rate tachograms and VPC-VPC intervals were depicted simultaneously. Group S demonstrated constant basic VPC-VPC intervals (1,285 to 2,052 msec, mean 1,738 +/- 219), with a coefficient of variation (CV) of 0.061 +/- 0.018. Their VPC coupling intervals were markedly variable (651 +/- 113 msec; CV = 0.193 +/- 0.034). Each patient's basic VPC-VPC intervals showed small diurnal alterations (minimum -13% +/- 3% to maximum +15% +/- 6%). VPC-VPC intervals in group F were not constant and showed marked variation. Group F VPC coupling intervals were shorter and constant (480 +/- 30 msec, P = 0.0002; with CV = 0.076 +/- 0.013, P < 0.0001). CONCLUSION: Ventricular parasystole with constant VPC-VPC intervals consistently became evident based on VPC dot patterns recorded on heart rate tachograms.

Adolescent↗
PubMed2000

Release of monocyte chemoattractant protein (MCP)-1 by a human alveolar epithelial cell line in response to mycobacterium avium.

Clinical strains of Mycobacterium avium isolated from patients with acquired immunodeficiency syndrome, but not a non-clinical laboratory strain (ATCC 25291), were found to stimulate the human alveolar epithelial cell line A549, to produce monocyte chemoattractant protein (MCP)-1. A549 cells were also found to produce elevated levels of MCP-1 in response to sonicates of the clinical strains of M. avium, and surprisingly, the non-clinical strain as well. However, sonic extracts of the clinical strains were found to induce significantly higher levels of MCP-1 production compared to extracts of the non-clinical strain (P < 0.001). These data suggest the existence of strain-related differences in antigen expression by M. avium. The clinical and non-clinical strains of M. avium were found to attach and invade, but not replicate in A549 cells indicating that MCP-1 production by A549 cells does require the presence of viable, replicating organisms. Activation of alveolar epithelial cells by exposure to M. avium resulting in the production of chemokines which recruit inflammatory cells to the site of infection may be an important regulatory pathway for the activation of pulmonary host defense.

Chemokine CCL2↗
PubMed2000

[Investigation of a new HIV-1 p24 antigen detection kit based on the enzyme-linked fluorescent immunoassay].

We investigated the performance of the new p24 antigen detection kit (VIDAS HIV p24) with the conventional antigen kit (HIV-1 Ag monoclonal; Abbott). The new kit is an enzyme-linked fluorescent immunoassay (ELFA) and all of the assay steps are performed automatically by the VIDAS instrument within 100 minutes. With the seven HIV-1 seroconversion panels, three seroconversions were detected on an average of 6.8 days earlier with ELFA than the conventional EIA kit. ELFA showed negative results for all of the 11 false positive samples by the combined (p24, anti-HIV) detection kit (VIDAS HIV DUO). The results obtained suggest that ELFA are very useful for an earlier diagnosis of HIV infection and re-test for false positive samples by other HIV diagnosis kits.

Enzyme-Linked Immunosorbent Assay↗
PubMed2000

Comparison of the pattern of atrophy of the corpus callosum in frontotemporal dementia, progressive supranuclear palsy, and Alzheimer's disease.

OBJECTIVES: The loss of the neurons in layer 3, one of the groups of cortical neurons most vulnerable in various degenerative brain diseases, results in axonal degeneration leading to atrophy of the corpus callosum. Previous studies showed callosal atrophy in three degenerative dementias: frontotemporal dementia (FTD), progressive supranuclear palsy (PSP), and Alzheimer's disease (AD). However, it is unclear whether a characteristic pattern of atrophy is present in each. The objective of this study was to investigate whether the pattern of the callosal atrophy was different among patients with FTD, PSP, or early onset AD. METHODS: Eleven patients with FTD, nine patients with PSP, 16 patients with early onset AD, and 23 normal controls, all age and sex matched, were studied using MRI. The ratios of midsagittal corpus callosum areas to the midline internal skull surface area on T1 weighted images were analyzed. The corpus callosum was divided into quarters: the anterior, middle-anterior, middle-posterior, and posterior portions. RESULTS: Compared with controls, all three patient groups had significantly decreased total callosal/skull area ratio. An analysis of covariance adjusted for the total callosal area/skull area ratio showed that the anterior quarter callosal/skull area ratio in FTD, the middle-anterior quarter area ratio in PSP, and the posterior quarter area ratio in AD were significantly smaller than those in the other three groups. CONCLUSION: Although atrophy of the corpus callosum is not specific to any degenerative dementia, the patterns of the atrophy are different among patients with FTD, PSP, or early onset AD. Differential patterns of callosal atrophy might reflect characteristic patterns of neocortical involvement in each degenerative dementia.

Aged↗
PubMed2000

Job strain, social support in the workplace, and haemoglobin A1c in Japanese men.

OBJECTIVES: To examine the association between job strain (defined in the model of job demands and job control) and social support at the workplace with levels of glycosylated haemoglobin A1c (HbA1c) METHODS: All male employees aged 40-60 in a manufacturing firm, Japan, were invited to take part in the study. A blood sample was taken from the participants and HbA1c (%) was measured. Job strain and social support at the workplace were assessed with the job content questionnaire (JCQ). After excluding those who had a history of diabetes mellitus or other chronic diseases, data from 268 male day workers were analyzed. RESULTS: Age adjusted average concentrations of HbA1c were significantly higher in the highest quartile group of job strain or the lowest quartile group of social support at the workplace (p<0.05). Multiple linear regression analysis indicated that job strain was significantly and positively related to HbA1c (p<0.05), whereas social support at the workplace was significantly and negatively related to HbA1c (p<0.05), both after controlling for other covariates. CONCLUSIONS: Greater job strain and lower social support at the workplace may be associated with increased concentrations of HbA1c. Increased blood glucose may be a physiological mediator between job strain or social support at the workplace and coronary heart disease.

Adult↗