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Biomedical subjects

S Takuma

Publications and source records attributed to S Takuma.

At least 37 records · Page 2Linked to original sources
PubMed1999

Changes in colonic mucosal permeability in mouse colitis induced with dextran sulfate sodium.

In this study we examined changes in colonic mucosal permeability induced by dextran sulfate sodium (DSS) during the acute phase of mouse colitis. To induce colitis, the mice were given drinking water containing 5% (w/v) DSS (MW = 40,000) ad libitum. Colonic mucosal permeability was evaluated by the permeation of Evans blue (EB) from the lumen into the wall of the colon on 1, 2, 3 and 7 days postadministration of DSS. Mucosal changes were also histologically examined daily for 7 days postadministration. The permeation of EB increased significantly by days 3 and 7 postadministration. Histological analysis showed that crypt loss was the initial change, with no inflammatory process and the surface mucosal epithelial cells remained morphologically intact. These histological changes developed on 2 to 3 days postadministration. Erosion was first recognized at 5 days postadministration. These findings indicated that the increase in colonic mucosal permeability may have occurred in 3 days postadministration, and the increase in mucosal permeability occurred before the appearance of the inflammatory process. This suggests that an increase in colonic mucosal permeability, leading to the destruction of mucosal barrier function, may play an important role in the induction of DSS-induced murine colitis.

Animals↗
PubMed1999

Lipoprotein(a) levels and apolipoprotein(a) isoforms related to life style risk factors.

Lipoprotein(a) [Lp(a)] has been considered to be a predictor of premature coronary heart disease and other cardiovascular diseases. Lp(a) levels are largely genetically determined, but the detailed mechanism of Lp(a) elevation is uncertain. We examined the association between Lp(a) levels and apolipoprotein(a) [apo(a)] phenotypes as well as that of Lp(a) level and other various conditions. The subjects were 280 healthy Japanese (102 males and 178 females) aged 39 to 70 years who were living in a rural community in 1992. We obtained apo(a) phenotypes determined by SDS-PAGE as well as Lp(a) levels and other cardiovascular risk factors. We combined apo(a) phenotypes form 4 groups according to molecular weights (from high apo(a) molecular weight to low: I, II, III and IV). Lp(a) levels were associated with apo(a) phenotype-groups, that is, they were inversely associated with apo(a) molecular weight. Small apo(a) phenotypes were less frequent than large ones. The median Lp(a) level was higher in smoking (29.2 mg/dL) than in non-smoking subjects (18.5 mg/dL) in phenotype-group III. Adjusted means of total cholesterol and fibrinogen levels in apo(a) phenotype-group IV were the highest of all phenotype-groups. Age, apo(a) phenotype, smoking status, total cholesterol and fibrinogen were positively correlated with Lp(a) levels by multiple regression analysis. Lp(a) levels were found to be mainly associated with apo(a) phenotype, but varied broadly within the same apo(a) phenotype at various conditions, such as smoking status and high total cholesterol.

Adult↗
PubMed1998

Evaluation of mitral valve disease using transesophageal echocardiography.

In the past 10 years, clinical application of transesophageal echocardiography (TE) has grown explosively. Intraoperative TE offers a powerful diagnostic and monitoring tool for the physicians in the cardiac operating room. The use of TE revolutionizes the assessment of patients with mitral valve disease. Surgical decisions are often altered based on the information obtained from TE. This review describes the basic features of TE as well as its uses in the intraoperative setting for evaluation of the mitral valve.

Echocardiography, Transesophageal↗
PubMed1997

[New surgical procedure for patients with dilated heart and end-stage cardiac failure (Batista procedure)].

A 53-year-old man with dilated cardiomyopathy underwent left ventriculoplasty (Batista procedure), a new surgical procedure, which reduces ventricular volume to improve left ventricular function. Left ventricular ejection fraction increased from 19.7% to 43.7%. Unfortunately, he died of pneumonia 12 days after surgery. This is the first such procedure in a human in Japan.

Cardiac Surgical Procedures↗
PubMed1994

[Surgical treatment of acute Stanford Type-A aortic dissection].

Twelve cases of Stanford Type-A aortic dissection were operated in an acute phase. The male vs female ratio was 3:9, and their ages ranged from 47 to 79 (mean 61.3) years old. Most of them complained of chest and/or back pain, and four of them complained of syncope. Eight patients had the history of hypertension. As to the complications of aortic dissection, cardiac tamponade was seen in two cases, myocardial infarction in one, and transient hemiplegia and paraplegia in one case each. In five cases, moderate to severe aortic regurgitation was also noted. All but one case were operated within twenty-four hours after admission. The replacement of the ascending aorta with a tube graft was performed in all cases including the two cases whose entries were located in the aortic arch. CABG was done concomitantly in three cases, and aortic valve replacement and CABG in one case. The open distal anastomosis was carried out under the systemic circulatory arrest combined with the retrograde cerebral perfusion. The systemic perfusion was reinstituted after the distal anastomosis was completed. In cases whose dissecting pseudo-lumen of the distal aorta was not thrombosed, the arterial cannulation site was shifted from the femoral artery to the tube graft. All but two cases were discharged from the hospital in good condition. One case, who had been transferred to the operating room under cardiac massage due to myocardial infarction, was lost by severe LOS three weeks postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

[Development of a perceived social support scale: for a Japanese population].

Social support is increasingly attracting interest in as a factor in epidemiological research of disease risks. However, at present, few methods for measuring social support that can be credited as having reliability and validity exist in Japan. Therefore a perceived social support scale was developed in relation to a population study of a town in Fukuoka prefecture. A method for measuring functional support from several external sources was designed consisting of a self-administered test provided with only two available response options--yes & no. Pretests were conducted twice in order to evaluate content validity and adjust the number of determinants and resulted in spouse, family members, and friends being selected to be primary sources of support. A factor analysis was applied to select 10 conditions with high internal consistency for each of the sources. Responses were scored 0 or 1, for 'no' or 'yes,' respectively. Subsequently each set of 10 variables was summed into an index ranking social support conditions for each of the three sources. The three highest ranking indicators from each of the respective sources were then integrated into a single comprehensive total social support score of the individuals. The inquiry method was applied on 277 adults, aged from 40 to 69 years, in the town. Intercorrelation between the indicators of support derived from the three sources was low and coefficients of reliability ranged from 0.892 to 0.978. The score of each set of the 10 variables were incorporated into a principal components analysis in order to determine factorial validity. All of the first factor loadings of the items measuring support from both spouse and family were greater than 0.7 and high eigenvalues were obtained. Therefore the methods applied to spouse and family were considered adequate to measure a given construct. The items measuring support from friends were divided into two factors, emotional support and tangible support.

Adult↗
PubMed1994

[A case of bronchial rupture and pulmonary laceration caused by blunt chest trauma].

A 37-year-old female was crushed by a traffic accident. She was in severe respiratory distress. A chest X-ray revealed right pneumothorax and multiple rib fractures. Shortly after the initiation of the positive pressure ventilation, severe subcutaneous emphysema developed and she became shock. The bronchoscopy showed the rupture of the right main bronchus which was repaired through a right posterolateral thoracotomy using interrupted monofilament PPP sutures. Pulmonary lacerations were also repaired by the same sutures. Postoperative bronchoscopic examination showed good healing without any stricture. It cannot be overemphasized that accurate diagnosis and urgent surgical management is mandatory in patients with bronchial rupture.

Accidents, Traffic↗
PubMed1994

[A case of acute aortic dissection associated with myxedema].

A 53-year-old female, who had been severe hypothyroidism for about ten years, was admitted Stanford type A acute aortic dissection. The replacement of ascending aorta with a composite graft and coronary artery bypass grafting were performed immediately. During the post operative period, many complications occurred including delayed awakening from anesthesia, paralytic ileus, colon perforation, hyperbilirubinemia, pulmonary edema, cerebral hemorrhage and bacterial endocarditis. In this case, intravenous administration of steroid and thyroid hormone was effective to keep hormone level in the normal range although enteral administration was ineffective. It was suggested that early active supplement therapy is mandatory to prevent postoperative complications.

Acute Disease↗
PubMed1992

Presence of multinucleate cells in the papillary layer of the Macaca fuscata enamel organ.

The enamel organ of Macaca fuscata from post-secretory transition to the early maturation stage of was investigated by means of light and electron microscopy. Unusual, large multinucleated cells were observed in the papillary layer. These cells contained organelles characteristic of the maturation stage ameloblast and often extended to the enamel surface, suggesting a possible origin from the ameloblast layer.

Ameloblasts↗
PubMed1991

Isolation of xylose reductase gene of Pichia stipitis and its expression in Saccharomyces cerevisiae.

A NADPH/NADH-dependent xylose reductase gene was isolated from the xylose-assimilating yeast, Pichia stipitis. DNA sequence analysis showed that the gene consists of 951 bp. The gene introduced in Saccharomyces cerevisiae was transcribed to mRNA, and a considerable amount of enzyme activity was observed constitutively, whereas transcription and translation in P stipitis were inducible. S. cerevisiae carrying the xylose reductase gene could not, however, grow on xylose medium, and could not produce ethanol from xylose. Since xylose uptake and accumulation of xylitol by S. cerevisiae were observed, the conversion of xylitol to xylulose seemed to be limited.

Aldehyde Reductase↗
PubMed1990

Electron-immunocytochemistry of laminin and type-IV collagen in the junctional epithelium of rat molar gingiva.

The present study was carried out to examine the ultrastructural localization of laminin and type-IV collagen in the junctional epithelium of rat molar gingiva by means of the indirect immunoperoxidase method. Intense laminin reaction occurred in both the internal and the external basal laminae. Laminin reaction products were observed within the cisternae of the rough endoplasmic reticulum of junctional epithelium cells and in concavities formed at the distal plasma membranes adjacent to the basal lamina. Small spherical bodies occurring in the concavities also reacted positively to laminin. Type-IV collagen reaction was intense in the external basal lamina. The internal basal lamina, however, showed no reaction for type-IV collagen. These results indicate that the internal basal lamina contains laminin but no type-IV collagen and that junctional epithelium cells seem very likely to be involved in the production of laminin.

Animals↗
PubMed1990

Evidence for uptake of basement membrane by differentiating ameloblasts in the rat incisor enamel organ.

Demonstration of type-IV collagen and acid phosphatase (ACPase) was carried out in the rat incisor enamel organ after the animals were fixed by perfusion with periodate-lysine-paraformaldehyde. Their incisors were dissected out, demineralized with EDTA, and prepared into 6-microns-thick frozen sections. The sections, which had been treated by means of antibody incubation for type-IV collagen, were washed with a Trismaleate buffer, incubated in Novikoff's medium for acid phosphatase (ACPase), and then incubated in a 3, 3'-diaminobenzidine solution. After osmification, the sections were embedded in epoxy resin for electron microscopy. The plasma membranes of the distal ends of the inner-enamel-epithelial cells were relatively even and were lined with a basement membrane. Type-IV collagen was localized both in the lamina densa and in the filaments attached to the lamina densa. In differentiating ameloblasts, the remarkably undulating distal plasma membranes formed irregular shallow and deep invaginations, and small cytoplasmic processes that penetrated the basement membrane. Coated pits occurred in various parts of these undulating plasma membranes. Positive reaction to type-IV collagen was observed in the invaginations and coated pits. ACPase-positive granules, present in inner-enamel-epithelial cells, increased in number and sometimes appeared close to both shallow and deep invaginations of differentiating ameloblasts. These results indicate that type-IV collagen in the basement membrane of the enamel organ is removed and degraded by differentiating ameloblasts by means of their engulfing system.

Acid Phosphatase↗
PubMed1989

Ultrastructure and composition of enamel in human dental fluorosis.

Materials used in this work were 13 permanent molars exhibiting dental fluorosis (between 5 and 9 on the Thylstrup-Fejerskov scale, 1978) obtained from adults (aged 20-40 years) living in regions with 3.5 ppm fluoride in the water supplies. Small but deep occlusal caries lesions necessitated extraction. Light and polarized microscopic, microradiographic, electron microscopic, and electron-probe- and ion-micro-analytical studies were made. Enamel surfaces were generally cloudy to opaque, with several pits or defects of various sizes and degrees of brown-staining. An extensively hypomineralized area extended from the inner enamel to the surface layer, which was mineralized to a high degree. The hypomineralized area contained sparsely arranged, flattened, hexagonal crystals with either perforated centers or defects extending from the perimeter and indicating either no or low fluoride content. The highly mineralized surface layer, however, was composed of many large, flattened, hexagonal crystals and extremely small, irregularly shaped crystals. Both types were free of central perforations and defects. A high fluoride concentration was determined in the highly mineralized surface layer. These findings suggest that the hypomineralized area undergoes caries-like changes in terms of crystal dissolution and that the highly mineralized surface layer contains hydroxyapatite and fluoridated-hydroxyapatite, or fluorapatite, or both.

Adult↗
PubMed1989

High resolution electron microscopy of enamel crystals in cases of human dental fluorosis.

Surface enamel from human subjects with dental fluorosis was studied by means of high-resolution transmission electron microscopy. Immediately below the relatively highly mineralized outermost surface enamel layer was an extensive hypomineralized area. The highly mineralized layer was composed of many large elongated hexagonal crystals and extremely small hexagonal crystals. Frequently the small crystals were attached to the periphery of the large crystals. In the hypomineralized area, large crystals were sparsely arranged; and a few small crystals were seen. Some large crystals showed either perforated centers or defects on their peripheries. These findings suggest that the hypomineralized area undergoes caries-like changes in terms of crystal dissolution and that the highly mineralized surface layer is either formed or modified by remineralization.

Adult↗
PubMed1989

Ultrastructural changes in rat-molar cementoblasts after administration of puromycin.

Ultrastructural changes in rat-molar cementoblasts after administration of puromycin were observed. Young Wistar male rats were injected with 200 mg/kg of puromycin dihydrochloride. At 10, 30, 60, and 180 minutes after the injection, the animals were fixed by perfusion with 2.5% glutaraldehyde-2.0% paraformaldehyde. After perfusion, the lower first molars were dissected out of the mandibles, and their cementoblast were observed in an electron microscope. Striking changes were seen in the Golgi apparatus and the rough endoplasmic reticulum after puromycin administration. The Golgi saccules were dilated and devoid of content. Golgi vacuoles and secretion granules were reduced in number. Numerous small, smooth-walled vesicles, 45-70 nm in diameter and a large number of coated vesicles were present in the Golgi area. The rough endoplasmic reticulum showed unusual shapes and arrangement. Ribosomes attached to the reticulum lost polysomal arrangement. These changes progressed following the time elapsed after experiment, and a great number of large vacuoles which contain fine flocculent material came to predominate the supranuclear areas of the cementoblasts.

Animals↗