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Biomedical subjects

H Muraki

Publications and source records attributed to H Muraki.

At least 19 recordsLinked to original sources
PubMed2004

Finite element contact stress analysis of the RPD abutment tooth and periodontal ligament.

OBJECTIVES: The purpose of this study was to determine the influence of the occlusal rest position in removable partial dentures on the displacement of the abutment tooth and the stress distribution in the periodontal ligament (PL). METHODS: We constructed three-dimensional finite element models of the mandibular first and second premolars. A layer of the PL and a mesial or distal occlusal rest were produced on the second premolar as an abutment. A zero displacement was prescribed on the outer surface of the PL and the first premolar. In each simulation, the rest was moved 0.05 mm vertically to the apical direction, with or without restriction of horizontal movements. We simulated the contact phenomena on the abutment surfaces, and calculated the movements of the abutment and stress distributions in the PL. RESULTS: We observed a maximum distal displacement of 42 microm at the buccal cusp of the abutment and a principal compressive stress of 0.35 MPa in the PL when the abutment was vertically loaded by a distal rest that was allowed to move horizontally. However, the displacements and stresses were relatively small, and were all within the physiological limitations of the tissues. The restriction of the horizontal movement of the rests was effective in reducing the horizontal displacements of the abutment, regardless of the rest position. CONCLUSIONS: The single vertical load exerted from either the mesial or distal rest on the abutment was unlikely to cause any mechanical damage to its supporting tissues.

Bicuspid↗
PubMed1999

New Prognostic Factors Associated with Long-term Survival in Node-Negative Breast Cancer Patients.

BACKGROUND: This study was undertaken to determine the absolute and relative value of angiogenesis, proliferating cell nuclear antigen (PCNA) and conventional prognostic factors in predicting relapse-free survival (RFS) and overall survival (OS) rates associated with long-term survival in Japanese patients with node-negative breast cancer. PATIENTS AND METHODS: Two hundred patients with histological node-negative breast cancer were studied. We investigated nine clinicopathological factors, including angiogenesis, PCNA using per-manent-section immunohistochemistry, clinicaltumor size, histological grade (HG), tumor necrosis, lymphatic vessel invasion (LVI), histological extension, histological classification, and infiltrating growth (INF), followed for a median of 10 years (range, 1 to 20). RESULTS: Twenty-one patients (10.5%) had recurrence and 15 patients (7.5%) died of breast cancer. Univariate analysis showed that PCNA, clinical tumor size, HG, angiogenesis, and LVI were significantly predictive of 20-year RFS or OS. Tumor necrosis was significantly predictive of OS, not of RFS. Multi-variate analysis showed that clinical tumor size (P = 0.0003), angiogenesis (P = 0.0003), PCNA (P = 0.0064), and HG (P = 0.0401) were significant independent prognostic factors for RFS. PCNA (P< 0.0001) and clinical tumor size (P = 0.0112) were significant independent prognostic factors for OS, while angiogenesis was a borderline significant factor. CONCLUSION: PCNA and angiogenesis were important new prognostic factors in node-negative breast cancer patients.

Journal Article↗
PubMed1995

[A clinicopathological study of angiogenesis in breast cancer].

To evaluate the clinicopathological significance and the objective methods for angiogenesis, we immunohistochemically stained all of the regions around the cancer nests with Factor VIII-related antigen staining. We also identified microvessels in the many areas all along the border between cancer nests and the stroma by 200 x power field. We then examined the relationship between the average microvessel count (AC/mm2) and clinicopathological factors and between a 10-year cumulative survival rate in 109 cases of primary breast cancer from 1971 to 1979. There were an average of 35 fields counted among all the cases, and AC was 39.1 +/- 16.1. AC without blood vessel invasion was 36.4 +/- 15.2, while AC with blood vessel invasion was 44.7 +/- 16.6 (p < 0.02). AC without node metastasis or with n1 alpha was 37.6 +/- 15.4, while AC with n1 beta or n2 or n3 was 45.2 +/- 17.4 (p < 0.05). There was no relationship between AC and clinical tumor size, histological classification, lymphatic invasion, nuclear grade, and histological extension. A 10-year cumulative survival rate in AC (> or = 39) was 62.4%, while that in AC (< 39) was 82.7% (p < 0.03). Thus AC was considered a useful prognostic factor.

Adult↗
PubMed1993

[Influences of 5'-deoxy-5-fluorouridine (5'-DFUR) on cell cycle in patients with breast cancer].

Recently, the effectiveness of preoperative chemotherapy for cancer treatment has attracted much attention. The authors conducted a study to investigate the influence of 5'-DFUR administration on the cell cycle, based on DNA analysis using FCM in patients with breast cancer. A total of 53 patients with breast cancer (Stages I, II and III) were investigated concerning tumor PyNPase activity and cell cycle phase. Subjects were stratified according to tumor diameter, histologic type and ER in the group receiving preoperative 5'-DFUR administration (25 patients) and the group not receiving 5'-DFUR (28 patients). The subjects in the group on 5'-DFUR preoperative administration were classified into three sub-groups according to total dosages of 400 mg (8 patients), under 4,800 mg (8 patients) and 4,800 mg or over (9 patients). In terms of tumor diameter, significant increases (p = 0.027) of S-phase were observed in patients with the diameters of 5 cm or more in the sub-group of under 4,800 mg dosage. Similar tendencies were seen in all drug administration groups (p = 0.05). However, no influence was observed on S-phase in the group without 5'-DFUR administration. In terms of ER stratification, ER(-) patients in the dosing groups showed increasing tendencies in S-phase and significant differences of G1- as well as G2+M phases. No differences in PyNPase activity were noted in each stratified group. Preoperative administration of 5'-DFUR resulted in alterations of cell cycle in breast cancers. In patients with a total drug dosage of under 4,800 mg and with tumor diameters of 5 cm or more, increases of S-phase and decreases of G1-phase were observed. It was suggested that 5'-DFUR acted in DNA synthesizing stage to accumulate S-phase inhibiting cell cycles. Consequently, this drug is considered useful for neoadjuvant chemotherapy.

Antineoplastic Agents↗
PubMed1992

[A case report of aorto-pulmonary window associated with atrial septal defect].

The patient was a one-year-old boy, who underwent surgery with a diagnosis of atrial septal defect (ASD). During operation, aorto-pulmonary window (A-P window) which had not been detected by the preoperative examinations, was found. Therefore, the A-P window was divided prior to closing ASD. The patient is in good condition six months after the operation. The causes of the inaccurate preoperative diagnosis were discussed.

Aortopulmonary Septal Defect↗
PubMed1992

[Clinical report of cimetidine therapy for the prevention of the gastro-duodenal bleeding after the open heart surgery].

The efficacy of cimetidine administration after the open heart surgery was studied using the cimetidine concentration examination in the twenty five consecutive cases. Cimetidine was administered intravenously. The cases were divided into five groups for the infusion period. There was no case which developed the gastro-duodenal bleeding after the surgery. The concentration of cimetidine has showed more than 0.5 microgram/ml in each group. It was concluded that the administration of 800 mg cimetidine infused more than three hours, repeated every twelve hours was the possible treatment for the prevention of the gastro-duodenal bleeding after the open heart surgery.

Adolescent↗
PubMed1989

[Effects on flow volume curve accompanied by aging--with emphasis on the relation between the change and FEV1.0%].

Changes in respiratory function were compared. The results obtained were as follows. Subjects selected were 462 normal healthy male adults with no disorders in respiratory and circulatory systems, of whom forced expiratory volume in 1 second (FEV1.0%) and peak flow (PF), forced expiratory volume in 75% (V75), forced expiratory volume in 50% (V50) and forced expiratory volume in 25% (V25) were determined. 1. Results of each measured value FEV1.0%, PF, V75, V50 and V25 decreased with age. But V50/V25 increased with age Minimum and maximum values were 6.86 and 36.46 in FEV1.0% and V25. 2. Relationship between FEV1.0% and V50/V25. Both FEV1.0% and V50/V25 did not show marked relation till 34 years. Individual variation occurs in 35 to 39 year old group. This current was famous in 40 to 49 year old group. But no individual variations were found over 50 year old. This suggested that aging affects not only large airways but also small airways, and which is accompanied with enlarged peripheral air way resistance and decreased expiratory flow volume

Adult↗
PubMed1987

A novel fibrinolytic enzyme (nattokinase) in the vegetable cheese Natto; a typical and popular soybean food in the Japanese diet.

A strong fibrinolytic activity was demonstrated in the vegetable cheese Natto, which is a typical soybean food eaten in Japan. The average activity was calculated at about 40 CU (plasmin units)/g wet weight. This novel fibrinolytic enzyme, named nattokinase, was easily extracted with saline. The mol. wt and pI were about 20,000 and 8.6, respectively. Nattokinase not only digested fibrin but also the plasmin substrate H-D-Val-Leu-Lys-pNA (S-2251), which was more sensitive to the enzyme than other substrates tried. Diisopropyl fluorophosphate and 2,2,2-trichloro-1-hydroxyethyl-o,o-dimethylphosphate strongly inhibited this fibrinolytic enzyme.

Chromatography, Gel↗
PubMed1987

[Fundamental studies on thyroid stimulating hormone immunoradiometric assay kit (TSH RIABEAD II)].

We have reported fundamental studies on the TSH immunoradiometric assay, using TSH RIABEAD II kit (Dainabot). The sensitivity of the assay was 0.03 mu IU/ml and its C.V. was 27.2%. Intra- and inter-assay C.V. were less than 5%. Dilution test and recovery test were good. Serum TSH level was 0.3-4.0 mu IU/ml in normal subjects, less than 0.03 mu IU/ml in untreated Graves' disease and subacute thyroiditis. Therefore, it was found that the clear difference exist in serum TSH levels between normal subjects and patients with untreated Graves' disease. There was a well correlation on the serum TSH levels between this method and TSH radioimmunoassay kit (Amerlex TSH, r = 0.983). Especially, the measurement of serum TSH levels, using immunoradiometric assay kit, was useful for the diagnosis of patients with Graves' disease.

Evaluation Studies as Topic↗