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Biomedical subjects

Y Ohtani

Publications and source records attributed to Y Ohtani.

At least 73 records · Page 4Linked to original sources
PubMed1997

Distribution and ultrastructure of the stomata connecting the pleural cavity with lymphatics in the rat costal pleura.

We investigated the detailed distribution and ultrastructure of the stomata connecting the pleural cavity and the lymphatics in the rat costal pleura by scanning electron, transmission electron and light microscopy. The mesothelial cells lining the costal pleura appeared as both flattened and thick cell bodies. The thick cells possessed more rough endoplasmic reticula, Golgi complexes, mitochondria, and free ribosomes than the flattened cells. The thick cells were distributed in the intercostal regions each cephalic to the junction of the costal cartilage and bone, and in the band-like regions along the cephalic and caudal sides of each rib in the lateral and dorsal thoracic walls. In the regions lined with thick cells, there were stomata [12.9 +/- 10.3 microns2 (mean +/- SD) in area] consisting of prolongations of thick mesothelial cells and funnel-like projections of lymphatic endothelial cells that came up along the rims of the pores (5.9 +/- 3.2 microns2 in average area) in the submesothelial collagen fiber network. At the stomata, the basal lamina of the mesothelium was continuous with that of the endothelium. The mesothelial cells forming the stomata were mostly in close contact with the endothelial cells, but some gaps also existed between them. Valve-like endothelial flaps were frequently observed wherever endothelial cells constituting the stomata merged into the submesothelial lymphatics. Also present were lymphatic bulges that were either in close contact with the base of the thick mesothelial cells or exposed through the mesothelial pores. The lymphatic network was especially well developed in the submesothelial layer at and around the thick-cell regions. The initial lymphatics drained into the intercostal collecting lymphatics, which in turn led into either the parasternal or paravertebral lymphatic trunk. Our results suggest that the stomata play a major role in absorbing fluids and particulates in the pleural cavity. The thick mesothelial cells appear to secrete chemotactic substances to the endothelial cells. Understanding the heterogeneous distribution of the stomata could prove to be important clinically in inflammatory diseases and tumors in the chest.

Animals↗
PubMed1997

Obliteration of the lymphatic trunks draining diaphragmatic lymph causes peritoneal fluid to enter the pleural cavity.

Pathways of peritoneal fluids to the pleural cavity in the rat were investigated by light microscopy and transmission electron microscopy (TEM). Intraperitoneally injected India ink was demonstrated to enter the subperitoneal lymphatics through lymphatic stomata, and to drain through the subpleural collecting lymphatics, into the parasternal, paravertebral and mediastinal lymphatic trunks as well as the thoracic duct. Five to 10 min after the intraperitoneal injection of India ink, the parasternal lymphatic trunk was ligated at the third intercostal space. Thirty minutes, 1 h, or 2 h after the ligation of either the right or the left trunk, India ink was macroscopically recognized only around the ligated trunk. When the right and left trunks were simultaneously ligated, India ink leaked around both trunks. Five hours after the ligation of both trunks, a massive amount of ink was located in the interstitium of the anterior thoracic wall. TEM revealed carbon particles passing through gaps of the lymphatic endothelial cells into the interstitial space, and partly reaching the mesothelial surface lining the anterior thoracic wall. Results show that obstruction or narrowing of the lymphatic trunks draining the diaphragmatic lymph causes a hydrothorax, indicating that this is at least one mechanism causing this during continuous ambulatory peritoneal dialysis and diseases with ascites.

Animals↗
PubMed1997

[Relations of "self-oriented perfectionism" to depression and hopelessness].

The purpose of this study was to construct a new multidimensional self-oriented perfectionism scale (MSPS) and to examine the relationship of self-oriented perfectionism to depression and hopelessness in college students. In Study 1, 26 original items of a new MSPS were administered to 132 students and factor analysis revealed 4 solutions: desire for perfectionism (DP), personal standard (PS), concern over mistakes (CM), and doubting of actions (D). Twenty items of the final MSPS had high reliability and validity as an instrument of measuring self-oriented perfectionism (Hewitt & Flett, 1991). In Study 2, 178 students completed a questionnaire consisting of MSPS, stressor scale, depression scale, and hopelessness scale. PS was negatively related to hopelessness, and CM and D were positively related to both depression and hopelessness. Students with high CM scores had higher depression than those with low CM scores, unrelated to the degree of stress.

Adult↗
PubMed1997

[T4 lung cancer: surgical indications based on results of surgical treatment].

During the period of 1981 and 1995, 54 patients with T4 lung cancer underwent pulmonary resection in our institutes. The actuarial survival rate of them was 30% at three years and 12% at five years. The five-year survival rate of 12 patients with complete resection was 33%. On the other hand, the five-year survival rate of 30 patients with incomplete resection was 9%. The five-year survival rates of 17 patients with N0 disease, 9 patients with N1 disease, and 22 patients with N2 disease were 13%, 40%, and 5%, respectively. There was a significant difference in survival between patients with N1 and N2 disease. Four patients survived for more than five years after the operation : two patients had invasion to the left atrium and two had a slight degree of pleural dissemination. Radical pulmonary resection may yield long-term survival in T4 lung cancer patients having invasion to the left atrium.

Adenocarcinoma↗
PubMed1997

[Usefulness of 99mTc-MIBI SPECT in the metastatic lesions of thyroid cancer].

99mTc-MIBI is widely used as a tumor-seeking agent for parathyroid tumor, lung cancer, etc. We tried to detect the metastatic lesions of thyroid cancer by 99mTc-MIBI SPECT and evaluated 131I-uptake in the region of 99mTc-MIBI accumulation. Twenty-seven cases of thyroid cancer (23 papillary adenocarcinoma, 3 follicular adenocarcinoma, 1 unknown) were examined by 99mTc-MIBI. All cases were confirmed by surgery. Thyroglobulin was measured in all cases before 99mTc-MIBI SPECT. 131I-therapy (4.5-5.5 GBq) was performed on 24 patients and whole body scintigram was taken 7-10 days after. Thirty minutes after an injection of 99mTc-MIBI (740 MBq), SPECT with a three-head gamma camera was performed. Abnormal accumulation of 99mTc-MIBI was noted in 14 patients, all cases detected on CT or MRI. In 11 of the 13 cases in which accumulation was not visualized, no metastasis was detected. Most cases of abnormal accumulation on 99mTc-MIBI showed a high level of thyroglobulin. Metastatic lesions of follicular adenocarcinoma in three patients (right humerus, axillary region and sternum) showed strong accumulation of 99mTc-MIBI, and 131I was strongly taken up in these lesions. 131I was also taken up in the metastatic lesions of papillary adenocarcinoma with marked accumulation of 99mTc-MIBI. 99mTc-MIBI did not accumulate in a case with diffuse pulmonary uptake of 131I. 99mTc-MIBI SPECT could detect occult metastatic lesions in the soft tissue more clearly than CT or MRI. In conclusion, 99mTc-MIBI study might be useful as a follow-up study of patients after surgery for thyroid cancer.

Adenocarcinoma, Follicular↗
PubMed1996

Ganglioside alterations in the central and peripheral nervous systems of patients with Creutzfeldt-Jakob disease.

We have examined the distribution and composition of gangliosides in central and peripheral nervous tissues from two patients with Creutzfeldt-Jakob disease (CJD). There were marked decreases in total ganglioside levels in CJD, with reductions in the cerebral cortex and cerebellum in the order of 20-30% and 50% of control values, respectively, though in spinal cord and sciatic nerve total gangliosides were not significantly altered. The percentage distribution of individual gangliosides was characterized by marked increases in GD3 and GD2, contrasting with severe decreases in GD1a, GD1b, GT1b and GQ1b; such changes were found throughout the patients' nervous tissues. An abnormal long-chain base composition was detected with the d20:1 component being decreased to less than 50% of control values, in the cerebrum, cerebellum and spinal cord. Changes in gangliosides occurred even in those tissues not severely affected neuropathologically. These ganglioside abnormalities are discussed in relationship to the pathogenesis of CJD.

Aged↗
PubMed1996

Apoptosis of colon cancers assessed by in situ DNA nick end-labeling method.

Apoptosis in colon cancers was investigated using in situ DNA nick end-labeling. Seventy-six colon cancer cases were divided according to histologically defined malignant grading, degree of invasion and other pathologic indicators. The apoptotic labeling index (ALI) was highest in cases with invasion limited to the submucosa, the difference as compared to other stages being statistically significant, while no correlation was noted between ALI and histological type. ALI significantly decreased with lymph node involvement of cancers. In contrast, there appeared to be no link with vessel invasion. ALI was significantly higher in lesions smaller than 2 cm in diameter. These results indicate that apoptosis in colon cancers is more frequent at a relatively early stage when the lesions are small, and suggest that the apoptotic phenomenon may play some role in regulating the size and progression of such tumors.

Adenocarcinoma↗
PubMed1996

Acute emphysematous cholecystitis associated with pneumobilia: a case report.

This report describes a rare case of acute emphysematous cholecystitis with pneumobilia in the common bile duct. The patient was a 66-year-old woman with a part history of diabetes mellitus, and operations for gastric and breast carcinoma. The chief complaint was pain in the right hypochondrium with severe right hypochondrial tenderness and distention of the gallbladder detected on examination. Laboratory tests showed leukocytosis, marked elevation of CRP, jaundice, liver dysfunction, and hyperglycemia. Gas was detected in the gallbladder on plain abdominal X-rays and CT scans of the abdomen, and a small amount of gas was also observed in the common bile duct. On the day of admission, percutaneous transhepatic gallbladder drainage (PTGBD) was carried out under ultrasound guidance, and Clostridium perfingens and E. coli were detected in the bile. Imaging after PTGBD showed no cystic duct obstruction. On the 12th day after PTGBD, cholecystectomy and choledochotomy with primary closure were performed. The postoperative course was good and the patient was discharged on the 15th day after surgery.

Acute Disease↗
PubMed1995

Isolation and characterization of a kettin-like protein from crayfish claw muscle.

A 540 kDa protein was isolated from crayfish claw muscle (closer). The secondary structure mainly consisted of beta-sheet (70%). The rotary shadowed images were long filaments, 300-360 nm long. It is localized in the sides of the Z-lines extending to the I band and elongatable upon stretch of muscle. Immunological crossreactivities strongly suggested that this protein corresponds to kettin (500-700 kDa) of insect striated muscle. In view of molecular shape and secondary structure, and immunological crossreactivities, it is suggested that this kettin-like protein belongs to connectin/titin family of striated muscle.

Actins↗
PubMed1995

Effects of exercise on plasma level of brain natriuretic peptide in congestive heart failure with and without left ventricular dysfunction.

This study was designed to determine whether plasma brain natriuretic peptide (BNP) increases in response to exercise in patients with congestive heart failure and to show what kind of hemodynamic abnormalities induce increased secretion of BNP during exercise. Plasma levels of atrial natriuretic peptide (ANP) and BNP and hemodynamic parameters were measured during upright bicycle exercise tests in seven patients with dilated cardiomyopathy and nine with mitral stenosis. At rest, there were no intergroup differences in cardiac output or pulmonary capillary wedge pressure; however, the group with dilated cardiomyopathy had higher left ventricular end-diastolic pressures and lower left ventricular ejection fractions than did the group with mitral stenosis. Plasma ANP levels were comparable between the dilated cardiomyopathy group (170 +/- 77 [SE] pg/ml) and the mitral stenosis group (106 +/- 33 pg/ml) (p, not significant), whereas BNP was significantly higher in the dilated cardiomyopathy group (221 +/- 80 pg/ml) than in the other group (37 +/- 10 pg/ml) (p < 0.05). The plasma concentration of BNP but not of ANP significantly correlated with left ventricular end-diastolic pressure and volume. Exercise increased plasma ANP and BNP in the two groups. The dilated cardiomyopathy group had a larger increment in BNP (+157 +/- 79 pg/ml) than did the mitral stenosis group (+17 +/- 5 pg/ml) (p < 0.05), although the increase in pulmonary capillary wedge pressure was greater in the mitral stenosis group. Thus exercise increases plasma levels of BNP, and impaired left ventricular function may be a main factor in the greater increment in BNP during exercise in patients with congestive heart failure.

Atrial Natriuretic Factor↗
PubMed1995

Dentatorubral-pallidoluysian atrophy (DRPLA): clinical, genetic, and neuroradiologic studies in a family.

The clinical, genetic, and neuroradiologic characteristics of dentatorubral-pallidoluysian atrophy (DRPLA) are delineated in six patients from three generations of a Japanese family. The clinical characteristics of the disease varied, the age at onset depending on patients with juvenile-onset were characterized by myoclonus, epilepsy, and mental retardation whereas cerebellar ataxia, choreoathetosis, and dementia were typical of adult- and senile-onset patients. All affected individuals showed one expanded allele with the repeat number of CAG at the DRPLA locus, ranging from 58 to 82, and a normal allele, ranging from 10 to 21. The most severely affected patient, a case of maternal transmission and with the largest allele, became bedridden in a vegetative state by age 12. On the CT and MRI, varying degrees of brain atrophy were present in all patients. T2-weighted MRI in patients with senile-onset showed symmetric high-signal lesions in the cerebral white matter, globus pallidus, thalamus, midbrain, and pons. However, MRI in younger patients revealed no such lesions and CT failed to demonstrate lesions in the globus pallidus and brain stem. Thus, intrafamilial heterogeneity of DRPLA was also evident on MRI. High-signal lesions involving both, subcortical white matter and thalamus may be characteristics of senile-onset patients and may correlate with their dementia.

Adult↗
PubMed1995

Effects of luminance contrast and phase difference on motion assimilation for sinusoidal gratings.

When a sinusoidal (test) grating is displaced horizontally by a phase angle of 180 deg in a two-frame apparent motion display, the perceived direction of motion is ambiguous; the test grating appears to move either to the left or to the right (or to both directions). On the other hand, when the test grating is displaced by 180 deg synchronously with the inducing gratings which, presented above and below the test grating, jump unambiguously in one direction (e.g. displaced by 90 deg), the test grating always appears to move in the same direction as the inducing gratings (motion assimilation). In the present study, the effects of luminance contrast and phase difference on motion assimilation were examined. The proportion of perceived direction of motion (left or right) was measured as a function of phase difference between the test grating in the first and the second frame. The magnitude of motion assimilation was evaluated as the change in the phase difference for which the proportions of observers' response were equal (50%) for both directions. The magnitude of motion assimilation increased with increase in the contrast of the inducing gratings or with decrease in the contrast of the test grating. Also, the magnitude increased as the phase difference of the inducing gratings departed from 180 deg. Based on these results, a quantitative formulation between the magnitude of motion assimilation, and the contrast and the phase difference of the stimulus gratings was derived. Further, a model was proposed which explains the stimulus dependences of motion assimilation in terms of response-integration among local motion detectors.

Contrast Sensitivity↗
PubMed1995

Establishment of functional imprinting of the H19 gene in human developing placentae.

We have found that the imprinted H19 gene can be expressed either biallelically or monoallelically in the developing human placentae. H19 biallelic expression is confined to the placenta until 10 weeks of gestation, after which it becomes exclusively maternal, and does not affect allele-specificity or levels of IGF2 expression. The promoter region of H19 is hypomethylated at all stages of placental development, while the 3' portion shows progressive methylation of the paternal allele with gestation. Our observations demonstrate that the establishment of functional H19 imprinting occurs during the early development of the placenta and provide an opportunity to understand the mechanism by which the H19 primary imprint is manifested in somatic cells.

Alleles↗
PubMed1995

Immune responsiveness to inhaled antigens: local antibody production in the respiratory tract in health and lung diseases.

The pulmonary defence mechanism in summer type hypersensitivity pneumonitis induced by Trichosporon cutaneum was investigated. We have studied the antibody response to fungal antigens in sera and bronchoalveolar lavage (BAL) fluids from patients with summer type hypersensitivity pneumonitis, bird fancier's lung, interstitial pneumonia associated with collagen vascular disease (INT-PNE), and from normal volunteers. Antigens extracted from fungi frequently isolated from home environments were used in ELISA to detect IgG and IgA antibodies in sera and BAL fluids. The results of the present study show that antibody titre in the respiratory tract to a variety of fungi from home environments is modulated by ongoing pulmonary inflammation, and that antibody production against inhaled antigens is altered by pulmonary inflammation resulting from diverse pathogenesis. This study concludes that the preexisting pulmonary inflammatory disease alters antibody production in the respiratory tract in response to inhaled fungi, and that the type of alteration depends in part on the etiology of the preexisting disease.

Aerosols↗
PubMed1995

[Relationship of perfectionism to depression and hopelessness in college students].

The purpose of this study was to construct a Japanese version of Hewitt and Flett's (1991b) Multidimensional Perfectionism Scale (MPS), and examine the relationship of perfectionism to depression and hopelessness in college students. In Study 1, a translated version of MPS was administered to 414 college students. Sixty-seven of them also completed seven personality scales in order to examine validity of the new scale. The self-oriented, other-oriented, and socially-prescribed perfectionism subscales have high reliability and validity. In Study 2, 163 college students completed a questionnaire of stressor, depression, and hopelessness scales, in addition to the Japanese MPS. Self-oriented perfectionism was negatively correlated with hopelessness, and socially-prescribed perfectionism positively with depression and hopelessness regardless of the degree of stressor. These results were different from those of Hewitt and Flett (1991b), and it was found that part of the self-oriented subscale correlated positively with hopelessness, and other part negatively. In the present study, the negative part appeared to have been dominant.

Adult↗
PubMed1995

Microanatomy of the rat diaphragm with special reference to the lymphatics and mesothelial stomata.

The three-dimensional microstructure of the rat diaphragm was studied in order to reveal morphological bases which permit peritoneal fluids to pass across the diaphragm to enter the pleural cavity. The methods used include scanning electron microscopy of either intact or alkali-treated tissues, enzyme-histochemistry, and confocal laser scanning microscopy (CLSM). The peritoneal and pleural surfaces of the diaphragm are covered with mesothelial cells studded with numerous microvilli. There are many round gaps between mesothelial cells on the peritoneal side of the diaphragm. The subperitoneal connective tissue contains voluminous, irregularly shaped lymphatics which extended many funnel-shaped projections of the endothelia towards the pored region of the mesothelium. On coming into contact with the mesothelium, many of the lymphatic projections are perforated at their ends, thus giving rise to stomata connecting the peritoneal cavity and lymphatic lumen. Some projections ended blindly while plugging the mesothelial pores, thereby making visible some intercellular gaps in this contact. The subperitoneal sheet of collagen fiber network possesses clusters of pores which tightly fit the passage of the lymphatic projections. CLSM of the diaphragm after intraperitoneal injection of FITC-dextran has demonstrated the tracer both in the lymphatic lumen and in the connective tissue spaces. The tracer has also been detected in the lymphatics located in the subpleural connective tissue space. These results indicate that peritoneal fluid is allowed to flow into the lymphatics directly through the stomata and indirectly through the intercellular gaps between endothelia and mesothelial cells, and then drain into the subpleural lymphatics. Discussions were made on the probable mechanisms by which a hydrothorax may occur during continuous ambulatory peritoneal dialysis.

Animals↗