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Biomedical subjects

T Ishida

Publications and source records attributed to T Ishida.

At least 1,315 records · Page 73Linked to original sources

Endocrinological and biophysical responses to further reduction in oxygenation following sustained hypoxemia in fetal goats.

OBJECTIVE: The purpose of this study was to determine fetal endocrinological and biophysical responses to the further reduction in oxygenation following prolonged nonacidemic hypoxemia in fetal goats. METHODS: Seven further hypoxic experiments were performed after prolonged (24-h) nonacidemic hypoxemia, caused by an infusion of nitrogen into the maternal trachea and by reducing uterine arterial blood flow in four chronically instrumented goat fetuses at 123-131 days' gestation. We measured arginine vasopressin, adrenocorticotropic hormone, cortisol, and catecholamines as endocrinological parameters. Fetal heart rate, fetal blood pressure, and fetal breathing movement were observed as biophysical parameters. RESULTS: Fetal arterial pO2 was significantly decreased from 27.0 +/- 1.2 mmHg (control) to 18.0 +/- 0.7 mmHg and 11.3 +/- 1.3 mmHg at the end of the prolonged hypoxemia and the further hypoxia, respectively. The further hypoxia induced reductions in fetal heart rate, increases in fetal blood pressure, and a series of gasping. Arginine vasopressin and catecholamines were elevated significantly by the further hypoxia. Although adrenocorticotropic hormone and cortisol were increasingly elevated, they did not reach a significant level. CONCLUSIONS: Some specific fetal responses-excessive elevations of fetal catecholamines, arginine vasopressin, accompanied with fetal gasping-were observed during further severe hypoxia.

Adrenocorticotropic Hormone↗

Assessing response to therapy of spinal metastases with gadolinium-enhanced MR imaging.

The utility of gadolinium-enhanced magnetic resonance (MR) imaging in assessing the response of spinal metastases to therapy was evaluated. Fifteen patients (62 affected vertebral bodies) with spinal metastases were evaluated with gadopentetate dimeglumine-enhanced imaging before and after irradiation or chemotherapy. Signal intensities of the lesions and of adjacent normal vertebral bodies were compared. Before therapy, metastatic foci enhanced significantly more than did normal vertebral bodies. After therapy, the lesions were divided into 37 responding lesions (group 1) and 25 nonresponding lesions (group 2). In group 1, lesion enhancement diminished considerably and the patients with these lesions remained clinically asymptomatic for 2-6 months. In group 2, lesion enhancement did not diminish much, and the difference between the groups was significant. Gadolinium-enhanced MR imaging may thus be a useful method for assessing the effectiveness of therapy for spinal metastases.

Breast Neoplasms↗

Preoperative local staging of rectal carcinoma with MR imaging and a rectal balloon.

Magnetic resonance (MR) imaging for the preoperative assessment of rectal carcinoma was evaluated. Thirty-three patients underwent MR imaging with a 1.5-T unit. On the basis of results of barium enema studies and/or digital examination, a balloon catheter was inserted to the level of the lesion before MR imaging. Both T1- and T2-weighted axial spin-echo images were obtained in all patients. With the balloon catheter, the three layers of the normal bowel wall could be seen on T2-weighted images. Muscular invasion was detected with a sensitivity of 90%, a specificity of 84%, a positive predictive value of 90%, a negative predictive value of 84%, and an overall accuracy of 88%. False-positive results were related to chemical shift artifact and intramural lymph node metastases. Perirectal fat invasion was detected with a sensitivity of 64%, a specificity of 89%, a positive predictive value of 82%, a negative predictive value of 77%, and an overall accuracy of 79%. One of the false-positive results was related to intramural lymph node metastases and the other to perirectal vessels. Evaluation of adjacent organ invasion was accurate in all patients. Lymph node metastasis was correctly detected in six of nine patients. Absence of lymph node metastasis was correctly predicted in 23 of 24 patients. Thus, MR imaging with a balloon catheter was useful for detection of tumor invasion into muscularis propria and adjacent organs; however, its demonstration of perirectal fat and lymph node involvement was less accurate.

Adult↗

Contrast-enhanced MR imaging of intrahepatic cholangiocarcinoma: pathologic correlation study.

The authors describe the enhanced magnetic resonance (MR) imaging appearance of intrahepatic cholangiocarcinoma. The MR images of eight patients with intrahepatic cholangiocarcinoma who underwent MR examination within 3 weeks before partial hepatectomy were retrospectively studied. The MR images, including a dynamic study, were compared directly with pathologic and histologic findings. The peripheral region of the medullary subtype of cholangiocarcinoma, with many tumor cells, showed greater enhancement relative to liver parenchyma in the early phase. The peripheral region of the scirrhous subtype, with fewer tumor cells showed less enhancement in the early phase. In one patient, the thin rim of the medullary tumor showed less enhancement in the late phase, and this rim corresponded to the peripheral region of the medullary tumor with many tumor cells. The central region of tumors with a large amount of fibrous tissue showed prolonged enhancement in the late and delayed phases. The thin rim of liver parenchyma around the tumor showed less enhancement in the early phase and greater enhancement in the late phase; this rim corresponded to congestive liver parenchyma with dilated sinusoids. Intrahepatic cholangiocarcinoma shows various enhancement patterns, which depend on both the histologic subtype and the degree and distribution of fibrosis within the tumor.

Aged↗

Neurilemmoma of the diaphragm mimicking a liver tumor: case report.

A 47-year-old male with a solid, previously cystic tumor in the subphrenic part of the liver consulted for surgery. Laparotomy showed a well-circumscribed tumor originating from the diaphragm, which made a significant depression in the liver. Complete removal of the tumor was achieved. Pathologic examination led to a diagnosis of neurilemmoma originating from the diaphragm.

Diagnosis, Differential↗

Heterotopic gastric mucosa in the gallbladder: sonographic and CT findings.

We present computed tomographic (CT) and sonographic findings of heterotopic gastric mucosa incidentally found in a 63-year-old male. CT showed a slightly high density area in the gallbladder, which was intermediately enhanced early after bolus injection of contrast medium. Ultrasonography showed an echogenic sessile polyp. Histologically, the tumor consisted of gastric fundic glands containing parietal cells and chief cells.

Choristoma↗

Lymphocyte subsets in lung tissues of non-specific interstitial pneumonia and pulmonary fibrosis associated with collagen vascular disorders: correlation with CD4/CD8 ratio in bronchoalveolar lavage.

This study was designed to evaluate the distribution of lymphocyte subsets in lung specimens that were obtained by open-lung biopsy from 8 patients with idiopathic nonspecific interstitial pneumonia/fibrosis (NSIP) and 10 patients with pulmonary fibrosis associated with collagen vascular disorders (PF-CVD). Distributions of B lymphocytes, CD4-positive T lymphocytes, and CD8-positive T lymphocytes were evaluated immunohistochemically and compared with the cell composition in BALF. Correlation between CD4/CD8 ratios in bronchoalveolar lavage fluids (BALF) and CD4/CD8 ratios in lung tissues was also examined. B lymphocytes were mostly restricted in lymphoid follicles. CD4-positive T lymphocytes were observed inside and around lymphoid follicles and in the thick fibrotic wall of reconstructed alveoli with fibrosis. In contrast, CD8-positive T lymphocytes were diffusely distributed, especially in relatively thin alveoli. Correlation was weak between CD4/CD8 ratios in lung tissue and CD4/CD8 ratios in BALF. However, even in patients with very low CD4/CD8 ratios in BALF, many CD4 lymphocytes were observed in lung tissues, suggesting that CD8-positive lymphocytes diffusely distributed in thin alveolar architecture were more easily recovered in BALF than CD4-positive lymphocytes. Therefore, a low CD4/CD8 ratio in BALF may indicate that the alveolar structure was not severely reconstructed by fibrosis. This is the first report that compared lymphocyte subsets in lung tissues and in BALF.

Aged↗

Fibrinogen degradation products influence PGI2 synthesis by cultured porcine aortic endothelial and smooth muscle cells.

The synthesis of prostaglandin I2 (PGI2) was found to decrease with age in cultured, porcine aortic endothelial cells. Arachidonic acid (AA)-induced PGI2 synthesis per cell at low cell density was higher than that at high cell density. PGI2 synthesis by cultured porcine aortic smooth muscle cells, without exogenous AA, was higher than that by cultured porcine aortic endothelial cells, while AA-induced PGI2 synthesis by cultured porcine aortic medial smooth muscle cells was lower than that by cultured endothelial cells. PGI2 synthesis by cultured smooth muscle cells incubated with fibrinogen degradation products (FDPs) for 24 h decreased. After incubation with FDPs for 24 h, AA-induced PGI2 synthesis by endothelial cells also diminished. These data suggest that PGI2 synthesis in the vascular wall is affected by FDPs, and that FDPs probably play an important role in the initiation of atherosclerosis.

Animals↗

Nonsurgical treatment of posterior fossa epidural hematoma.

The recommended treatment for posterior fossa epidural hematoma has been prompt surgical evacuation. We report 2 patients who were treated conservatively. Both patients were younger than 10 years of age and developed subacute symptoms and signs. Serial computed tomography demonstrated complete resolution of the hematomas and no development of hydrocephalus during nonsurgical treatment. They recovered well without any neurologic deficits. In order to evaluate an indicative factor for nonsurgical treatment in young children with posterior fossa epidural hematoma, we review both of our patients and 36 well-documented patients from the literature, all of whom were younger than 10 years of age. The results demonstrate that the development of hydrocephalus is a critical factor in clinical progression. Nonsurgical management can be applied in these circumstances until spontaneous resolution of the hematoma unless early signs of medullary compression appear acutely after head trauma or serial computed tomography demonstrates the development of hydrocephalus followed by medullary compression.

Child↗