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Biomedical subjects

T Hamada

Publications and source records attributed to T Hamada.

At least 19 recordsLinked to original sources
PubMed1995

Antioxidant and prooxidant roles of copper in Tween 20-induced hemolysis of hamster and pig erythrocytes containing marginal vitamin E.

The concentration-dependent effects of copper acting either as an antioxidant or as a prooxidant were examined in vitro using Tween 20-induced hemolysis. When cupric ion concentration was more than 10 microM, free copper(II) acted as a prooxidant; both extensive hemolysis and production of unknown thiobarbituric acid-reactive substance occurred in hamster and pig erythrocytes irrespective of vitamin E status. However, when cupric ion concentration was 2-4 microM in the incubation medium, copper showed a clear antioxidant activity, reducing both hemolysis and malondialdehyde production induced either by diluted peroxide-containing Tween 20 with ascorbic acid and sodium azide in vitamin E-deficient hamster erythrocytes, or by peroxide-containing Tween 20 in pig erythrocytes containing marginal amounts of vitamin E. Copper(II) is taken up by the erythrocytes, where copper(I)-complexes may contribute to the protection of cells with membrane vitamin E against oxidative radical attack.

Animals↗
PubMed1995

Serum pyridinolines as specific markers of bone resorption in hemodialyzed patients.

Serum levels of hydroxylysyl pyridinoline and lysyl pyridinoline were quantified in uremic patients undergoing maintenance hemodialysis and in healthy subjects. Pre-hemodialysis serum levels of hydroxylysyl pyridinoline and lysyl pyridinoline in the hemodialyzed patients were significantly higher than those in healthy subjects. Serum levels of hydroxylysyl pyridinoline and lysyl pyridinoline decreased significantly after hemodialysis with reduction rates of about 40%. Pre-hemodialysis serum levels of hydroxylysyl pyridinoline and lysyl pyridinoline correlated significantly with intact parathyroid hormone, osteocalcin and bone-specific alkaline phosphatase. Lysyl pyridinoline showed better correlations with these parameters than hydroxylysyl pyridinoline. Parathyroidectomy markedly decreased serum levels of hydroxylysyl pyridinoline and lysyl pyridinoline. These results indicate that serum pyridinolines, especially lysyl pyridinoline, may be used as specific biochemical markers of bone resorption in hemodialyzed patients.

Acid Phosphatase↗
PubMed1995

Ovarian mucinous cystadenocarcinoma with sarcoma-like mural nodules.

A rare case of ovarian mucinous cystadenocarcinoma with sarcoma-like mural nodules is reported. Macroscopically, nodular or granular lesions were scattered over the inner surface of a huge, multilocular tumor in the left ovary. The histopathological features were consistent with those of previously documented cases, except significant squamous metaplasia in the present case. The pleomorphic sarcoma-like cells showed a positive reaction for vimentin and alpha-antichymotrypsin but were negative for carcinoembryonic antigen and common epithelial membrane antigen by immunohistochemistry. Electron microscopically, the tumor cells had neither desmosomes nor secretory granules, but they possessed abundant intermediate filaments. Both immunostaining and ultrastructure suggested that the sarcoma-like nodules were derived from reactive proliferation of fibrohistiocytic cells. The fibrohistiocytic reaction seemed to occur in response to hemorrhage, because hemorrhage was reported to be associated with the mural nodules in most of the previous cases as well as ours.

Cystadenocarcinoma, Mucinous↗
PubMed1995

Mild emphysema: a novel method using formalin-fixed lungs for computed tomography and pathological analyses.

We evaluated a novel method of computed tomography (CT) analysis using formalin-fixed lungs of autopsy cases with mild emphysema. Eight formalin-inflated lungs (FILs) obtained at autopsy were examined using CT after draining off the formalin and air inflation with an air pump, and subjected to pathological study including pathological scoring of emphysema and microscopic image analysis (MIA). Satisfactory CT examination was carried out within 5 h of lung fixation. The mean alveolar area determined by MIA correlated highly with the lung volume (r = 0.845) and CT score (r = 0.722). This method is simple compared with conventional polyethylene glycol fixation for CT and enables CT examination of resected lungs without anxiety about biohazards, Mild emphysema can be detected by MIA.

Aged↗
PubMed1995

Modulation of the anti-Candida activity of apo-lactoferrin by dietary sucrose and tunicamycin in vitro.

The sensitivity to apo-lactoferrin (apo-LF) of two oral isolates each of Candida albicans and C. krusei preincubated in either sucrose- or tunicamycin-supplemented media was investigated. Known apo-LF-sensitive isolates of both C. albicans and C. krusei demonstrated significantly increased resistance to apo-LF when preincubated in sucrose-supplemented media, but such preincubation had no effect on an apo-LF-resistant isolate of C. albicans, irrespective of the sugar concentration in the medium. Surprisingly, an apo-LF-resistant isolate of C. krusei demonstrated increased susceptibility to apo-LF when preincubated in sucrose. Further, when preincubated with tunicamycin, a chemical that interferes with candidal cell-wall formation, the susceptibility to apo-LF of the resistant isolates increased significantly. These results, when extrapolated in vivo, imply that dietary sucrose may diminish the anticandidal potency of salivary lactoferrin. However, the aberrant behaviour of a single isolate of C. krusei under these circumstances is possibly due to the different cell-wall structure of this yeast and needs to be further investigated.

Apoproteins↗
PubMed1995

Properties of highly cross-linked autopolymerizing reline acrylic resins.

Transverse bend strength tests and water sorption and solubility tests were done to compare the properties of highly cross-linked autopolymerizing reline resin with those of conventional non-cross-linked autopolymerizing reline resins. The relationship between composition and properties of autopolymerizing reline resins was also investigated. Highly cross-linked reline resins and the one that contained mainly poly(methyl methacrylate) and methyl methacrylate had a higher transverse bend strength and modulus of elasticity than the other reline resins (p < 0.01). The highly cross-linked reline resins also had significantly lower water sorption than the other reline resins (p < 0.01). Reline resins, except for one, had significantly higher solubility than heat-polymerizing denture base acrylic resins (p < 0.01).

Acrylic Resins↗
PubMed1995

Asymmetry of masticatory muscle activity during intercuspal maximal clenching in healthy subjects and subjects with stomatognathic dysfunction syndrome.

The present study investigated the asymmetry of masticatory muscle activity during maximal intercuspal clenching in healthy subjects and subjects with stomatognathic dysfunction syndrome. Stomatognathic dysfunction syndrome, unilateral mastication and the asymmetry of masticatory muscle activity appear to be related to each other. The asymmetry of masseter muscle activity was greater as stomatognathic dysfunction became increasingly severe. Because fatigue and pain are produced more quickly by unilateral clenching than bilateral clenching, clenching under conditions of left and right muscular imbalance can further aggravate stomatognathic dysfunction. It is suggested the asymmetry of masseter muscle activity during maximal clenching correlates with the onset of the stomatognathic dysfunction syndrome. Stomatognathic dysfunction syndrome is closely related to the asymmetry of masseter muscle activity and only slightly related to the asymmetry of temporal muscle activity. The asymmetry of anterior temporal muscle activity appears to have little clinical significance.

Adolescent↗
PubMed1995

Spinocerebellar ataxia 1 (SCA1) in the Japanese in Hokkaido may derive from a single common ancestry.

Spinocerebellar ataxia 1 (SCA1) is caused by expansion of an unstable CAG triplet repeat located on the short arm of chromosome 6. Precise mapping has shown a positional relationship to closely linked markers in the order of D6S109-D6S274-D6S288-SCA1-AM10GA-D6S89+ ++-EDN1 from centromere to telomere. The haplotype which cosegregated with the disease was determined in 12 Japanese pedigrees with SCA1. Although the alleles of the SCA1 haplotype varied from pedigree to pedigree, depending on the distance from the SCA1 locus, the affected and presymptomatic subjects carried the same alleles at D6S288 and D6S274. All the families with SCA1 had migrated from either Miyagi or Yamagata Prefectures, neighbouring areas in the Tohoku District, the northern part of Honshu which is the main island of Japan. It seems highly likely that SCA1 in the Japanese, at least those residing in Hokkaido, derives from a single common ancestry.

Chromosome Mapping↗
PubMed1995

The effects of cross-linking agents on some properties of HEMA-based resins.

The use of 2-hydroxyethyl methacrylate (HEMA)-based polymer as a biocompatible material has been well-established. HEMA-based resins containing cross-linking agents have several potential clinical applications. It is hypothesized that the incorporation of cross-linking agent will improve the mechanical properties of HEMA-based polymers while reducing water absorption and solubility. The purpose of the work reported here was to test this hypothesis and to determine the most effective cross-linking agent. A relationship among flexural strength, modulus, water absorption and solubility, and concentration of cross-linking agent was demonstrated. Strength and modulus tend to increase as the cross-linking agent concentration is increased, up to about 50%, after which the values level out or begin to fall. Water absorption drops with increasing cross-linking agent over the whole range of concentrations. Solubility tends to show a small decrease initially (up to 40%), followed by a noticeable increase as cross-linking agent concentration is increased. The trends were similar for all cross-linking agents, although there were differences in the absolute values in all properties depending upon the type of cross-linking agent used.

Absorption↗
PubMed1995

The prozone phenomenon in secondary syphilis.

We describe a 37-year-old woman with secondary syphilis, in whom the prozone phenomenon (false-negative test in undiluted specimens) occurred. The patient had been maintained on cyclosporine and prednisolone after renal transplantation. B-cell dysfunction induced by continuous immunosuppression may lead to higher non-treponemal serological titers. Non-treponemal testing should be repeated using serum dilutions to prevent missing the diagnosis of syphilis.

Adult↗
PubMed1995

Blood flow velocity waveforms of the fetal middle cerebral artery in pregnancies complicated by diabetes mellitus.

Fetal blood flow velocity waveforms of the middle cerebral artery were measured by pulsed Doppler ultrasound in 43 pregnant women with diabetes mellitus (33 class B, 3 class C, 6 class D and 1 class R). The recordings were performed between 24 and 38 weeks of gestation. A total of 122 recordings were analyzed prior to establishing the resistance index (RI = peak systolic velocity minus diastolic velocity/peak systolic velocity). The mean maternal serum glucose was 124.3 mg/dl (range: 72.7 to 281.5 mg/dl), the mean hemoglobin A1c was 6.03% (range: 3.3 to 11.0%) and the mean fructosamine level was 255.97 mumol/L (range: 205 to 397 mumol/L). The resistance index did not differ between the fetuses of the diabetic mothers in our study population. Additionally, no significant correlation was noted between RI values and serum glucose levels (r = 0.03), hemoglobin A1c levels (r = 0.13) or fructosamine levels (r = 0.04) during the period of 26 to 34 gestational weeks. These data indicate that the RI within the fetal cerebral artery is unaffected by the maternal glycemic control when mean serum glucose levels are below 280 mg/dl.

Blood Flow Velocity↗
PubMed1995

[Combination therapy with arbekacin and fosfomycin against postoperative severe mixed-pneumonia of MRSA in primary lung cancer patients].

We experienced successful treatment of postoperative severe pneumonia of Methicillin-resistant Staphylococcus aureus (MRSA) with combination therapy of Arbekacin (ABK) and Fosfomycin (FOM) in three lung cancer patients. Case 1 was a advanced age of seventy-nine man who had had right upper lobectomy. Case 2 was a 61-year-old man who had had left lower lobectomy and extended bilateral mediastinal lymph-node dissection through the median sternotomy. And case 3 was a 59-year-old man who had suffered from pulmonary embolism after right pneumonectomy and partial resection of left atrium and superior vena cava. All cases were immuno-compromised patients and super-infected with Gram-negative rods, and Pseudomonas aeruginosa in case 1 and case 3. Clinical symptoms were improved after the start of administration of ABK and FOM inspite of ineffectiveness of prior treatment with other antibiotics. We added staggered chemotherapy of Sulbactam/Cefoperazone (SBT/CPZ) and Ceftazidime (CAZ) for case 1 and case 3 respectively. Thus, the combination therapy of ABK and FOM might be useful for severe pneumonia of MRSA in the immunocompromised patients, and the combined staggered chemotherapy of beta-lactum agents and above would be the first choice in the treatment for the case involving Pseudomonas aeruginosa.

Aged↗
PubMed1995

[A case of systemic arterial supply to the normal left basal segments with anomalous return of the left inferior pulmonary vein].

A 38-year-old man was admitted to Yatsushiro General Hospital because of an abnormal shadow on chest X-ray film. Chest X-ray film showed a tumorous shadow in the left posterior basal segment (S10). Chest CT scan showed that this shadow was consisted of torutuous vessels and was connected to the descending thoracic aorta. Angiographic examinations showed that there was no normal left basal trunk of the pulmonary artery, and revealed an anomalous arterial supply to the basal segments from the descending thoracic aorta, with an anomalous left inferior pulmonary vein. The left bronchial tree appeared normal during fibroptic bronchoscopy (confirmed by post-operative bronchography). From these findings, we determined that this patient had an systemic arterial supply to the normal basal segments. Furthermore, this patient had an anomalous left inferior pulmonary vein, which took a peculiar route to the left atrium. The left lower lobe and the anomalous systemic artery were resected. In the resected specimen, the bronchi of the left lower lobe had a normal structure and showed a normal pattern of distribution. This anomalous systemic artery had an elastic component.

Adult↗