Oxidation reaction of steroid alcohols by ruthenium tetroxide.
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Alcohols↗
Biomedical subjects
H Nakata
Publications and source records attributed to H Nakata.
Renal angiomyolipoma: evolutional changes of its internal structure on CT.
BACKGROUND: We evaluated interval changes of the internal structure of renal angiomyolipomas in relation to the doubling time on computed tomography (CT). METHODS: A retrospective review of 42 renal angiomyolipomas in 10 patients who had been followed up for more than 5 months with CT was performed. The doubling time of each tumor was estimated. We classified the internal structures of the tumors into five types, based on the fat component percentage. We compared changes between initial and follow-up CT, and the relationship with the doubling time was evaluated. RESULTS: The fat component increased more than the soft tissue component in 15 tumors (36%). The soft tissue component increased more than the fat component in only one tumor, in which an intratumoral hemorrhage occurred during the follow-up period. Twenty-six tumors (62%) showed no change. Most tumors with relatively long doubling times did not show a change in their internal structures. CONCLUSION: The growth of renal angiomyolipoma is due mainly to an increase in its fat component. An increase in the soft tissue component suggests the development of an intratumoral hemorrhage.
Adult↗
High-resolution computed tomography of Japanese summer-type hypersensitivity pneumonitis.
The high-resolution computed tomographic (CT) manifestations of Japanese summer-type hypersensitivity pneumonitis in eight patients were correlated with those of their chest radiography and with their histological findings. Histologically proven small granulomas were clearly demonstrated on CT as miliary opacities in five patients whose chest radiographic findings were normal. In two patients, these abnormalities were observed both by CT and chest radiography. High-resolution CT provides detailed morphological information about the lung parenchyma; it is an excellent means of following the clinical courses of hypersensitivity pneumonitis. CT is particularly useful for detecting persistent granulomas when symptoms subside and chest radiography becomes normal or nearly so.
Adult↗
Bamboo foreign bodies in lung parenchyma: CT features.
The computed tomography (CT) findings in two cases of posttraumatic bamboo foreign bodies imbedded for many years in lung parenchyma are presented. These foreign bodies consisted of relatively cylindrical structures of high density, and were highly suggestive of bamboo.
Accidental Falls↗
CT and MRI manifestations of primary pulmonary plasmacytoma.
Primary pulmonary plasmacytoma (PPP) is rare and its radiographic appearances have been seldom described. We report on a patient with PPP presenting with a hilar mass on chest radiograph. The diagnosis was confirmed by immunohistochemical study of the resected specimen. The computed tomographic and magnetic resonance imaging findings are presented.
Contrast Media↗
Expression of Ras GTPase-activating protein (GAP) in human normal chorionic villi and hydatidiform mole.
Ras GTPase-activating protein (GAP), an important downregulator of Ras activity, has previously been shown to be abundant in human placenta. The expression of p120 and p100 isoforms of GAP in human normal chorionic villi (n=5) and hydatidiform mole (n=5) was investigated to clarify the involvement of Ras GAP in the growth of chorionic villi in the first trimester of pregnancy. Immunoblot analysis revealed that both p120- and p100-GAP isoforms were remarkably less expressed in mole villi than in normal chorionic villi. The expression of p100-GAP significantly reduced in comparison with that of pl20-GAP in mole villi. Northern blot analysis showed that the amount of GAP mRNA reduced in hydatidiform mole less than one-third of that in normal chorionic villi. The GAP activity, measured by the effect of tissue extract on the hydrolysis of Ras-bound GTP, was significantly lower in hydatidiform mole than in normal chorionic villi. These results suggest that Ras GAP may play an important role in the normal growth and differentiation of human chorionic villi in the first trimester.
Animals↗
Bronchogenic cyst with high CT number: analysis of contents.
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Adult↗
Computed tomography of residual hepatomas following transcatheter arterial embolization.
Computed tomography and angiography following transcatheter arterial embolization (TAE) was performed for 29 patients with hepatomas. In three cases crescent-shaped isodense regions were observed posterior to the necrotic tumor after TAE. They were located in the superior posterior segments of the right hepatic lobes and were consistent with residual tumor supplied by the right inferior phrenic artery. Recognition of this CT finding after TAE is important for evaluating the extent of embolization of the tumor.
Aged↗
MRI of bronchogenic cysts.
The MR appearance of eight bronchogenic cysts is reported. All the cysts appeared homogeneous and were of very high signal intensity, approximating that of CSF on spin-echo T2-weighted imaging, and of relatively high intensity, between that of muscle and subcutaneous fat on T1-weighted imaging. The cysts were round or ovoid and were well demarcated. These findings are consistent with the fluid-containing properties of cysts.
Adipose Tissue↗
Signal intensity characteristics of mediastinal cystic masses on T1-weighted MRI.
OBJECTIVE: We evaluated the intracystic MR signal intensity of mediastinal cystic masses to identify characteristic intensity patterns according to histologic type. MATERIALS AND METHODS: Magnetic resonance imaging was performed on 26 cystic mediastinal masses consisting of 8 thymic cysts, 5 bronchogenic cysts, 4 pericardial cysts, 5 cystic teratomas, and 4 cystic neurogenic tumors. Signal intensity ratios of each cyst to muscle were calculated on T1-weighted imaging. Surgical records were reviewed to document the presence of intracystic hemorrhage. Chemical analysis of intracystic fluid was performed in three cases. RESULTS: Bronchogenic cysts, cystic teratomas, and cystic neurogenic tumors had relatively high levels of signal intensities. Each pericardial cyst had a lower signal intensity than muscle. The signal intensities of thymic cysts were variable. Intracystic hemorrhage was present in 1 bronchogenic cyst, 2 cystic neurogenic tumors, 4 cystic teratomas, and 3 thymic cysts. No hemorrhage was found in any of the pericardial cysts. Sebaceous fluid was present in 1 cystic teratoma. CONCLUSION: The varying intensities of different cysts were considered to reflect the nature of the intracystic fluid. Since the nature of the fluid can reflect the histology to some extent, T1-weighted MRI will help to differentiate cystic mediastinal masses.
Bronchogenic Cyst↗
Pulmonary adenocarcinoma with micropapillary component: an immunohistochemical study. Case report.
Micropapillary carcinoma has been described in various organs, including the breast, urinary bladder, ovary and lung. We here present a case of pulmonary micropapillary carcinoma in a 72-year-old Japanese man who died of respiratory failure and septic shock, following which autopsy was performed. A mass measuring 2.5 x 2.5 x 2.5 cm was observed in the left lower lobe of the lung. The tumor showed moderately differentiated papillary adenocarcinoma with a focal micropapillary component. Carcinomatous lymphangiosis was also observed in the left lung and metastatic lesions were observed in the bilateral lung, liver, vertebra, muscle layer of the urinary bladder, right adrenal gland, spleen and lymph nodes. The micropapillary component was predominant at some metastatic sites. Immunohistochemically, both the adenocarcinoma and micropapillary components were positive for cytokeratin (CK) 7, CK19, TTF (thyroid transcription factor)-1, carcinoembryonic antigen (CEA) and surfactant apoprotein A (SP-A), and negative for CK20, estrogen receptor, progesterone receptor, uroplakin III, and CA125. The invasive area of the conventional adenocarcinoma component contained a large number of myofibroblasts, whereas the stroma of the micropapillary component contained a small number of myofibroblasts. However, no myofibroblasts were observed in the stroma of the central core of the non-invasive micropapillary carcinoma. Several lymphatic invasions by neoplastic cells were identified in the peripheral area of the micropapillary component using D2-40 antibody. The immunohistochemical profile may be helpful in determining the primary location of the neoplasm containing micropapillary features. Myofibroblasts are present in the stroma of the invasive neoplastic nests in the micropapillary component as well as the conventional adenocarcinoma component, and D2-40 monoclonal antibody may be useful for evaluating the lymphatic invasion of pulmonary micropapillary carcinoma.
Adenocarcinoma, Papillary↗
Involvement of beta-adrenergic receptor kinase-1 in homologous desensitization of histamine H2 receptors in human gastric carcinoma cell line MKN-45.
The poorly differentiated human gastric carcinoma cell line MKN-45 possesses histamine H2 receptors which are homologously desensitized by histamine. In order to clone the cDNA of a receptor kinase specific for H2 receptors, we performed RT-PCR at a low annealing temperature using oligo-DNA primers bearing the conserved sequences of the kinase domain of the G protein-coupled receptor kinase (GRK) family. However, we were able to isolate only cDNAs for beta-adrenergic receptor kinase 1 (beta ARK1) and GRK6. Interestingly, treatment of MKN-45 cells with beta ARK1 antisense phosphorothioate oligo-DNA (PON) resulted in significant loss of desensitization of H2 receptors by histamine, whereas GRK6 antisense PON had no effect. Thus, beta ARK1 appears to be involved in the homologous desensitization of H2 receptors in MKN-45 cells.
Blotting, Northern↗
Pancoast tumour treated with combined radiotherapy and hyperthermia--a preliminary study.
Six patients with Pancoast (superior sulcus) tumours were treated with combined radiotherapy and hyperthermia from April 1986 to December 1989. Radiotherapy was performed using 10 MV X-ray, and all patients received total doses of 60-74 Gy, in five fractions per week, during 5.5-15 weeks. Hyperthermia was performed once or twice a week within 30 min after each irradiation, using 8 MHz RF capacitive heating equipment (Thermotron RF-8). Partial response, defined as 50% or more regression of the tumour, was observed in four of the six patients. Three patients are alive 30, 28, and 14 months after their treatments. Radiotherapy combined with hyperthermia appears to be a promising and effective means for treating Pancoast tumours.
Adenocarcinoma↗
MR imaging in uterine cervical cancer after radiotherapy.
The usefulness of MR imaging (MRI) in uterine cervical cancer after radiotherapy was evaluated in 18 patients. MRI was performed before and within one month after radiotherapy. In eight patients the uterus assumed a nearly normal appearance with resolution of the tumor on MRI. In another eight patients the tumors resolved, but an area of high signal intensity remained at the cervix. In these patients the tumors were well controlled at clinical examinations and during the mean follow-up period of 15-18 months. Therefore a persistent area of high signal intensity alone at the cervix on MRI is not itself indicative of residual tumor. An area of high signal intensity and a residual cervical mass persisted in two cases, and they were histologically proven to be due to residual tumor. Both patients died of recurrent disease at seven and 11 months after their radiotherapy. We conclude that MRI is useful for evaluating patients with cervical cancer at the completion of radiotherapy, and that MRI complements conventional clinical examinations.
Brachytherapy↗
Chronic liver disease: value of volumetry of liver and spleen with computed tomography.
Volumetric comparisons of portions of liver and spleen were performed in patients with chronic liver diseases to determine their diagnostic value. Volumetric ratios of liver and spleen were determined by CT examination in 34 normal subjects and 125 consecutive patients with histologically proved liver cirrhosis, chronic active hepatitis, chronic persistent hepatitis, acute hepatitis, or fatty liver. Ratios of caudate lobe, spleen, and lateral segment of the left lobe of the liver to the remainder of the liver, right lobe and medial segment of the left lobe (RL+LM), were calculated. The product of caudate lobe/RL+LM and spleen/RL+LM was of value in differentiating liver cirrhosis from other liver disease, with a sensitivity of 60%, specificity of 98%, and accuracy of 86%. The same ratios differentiated liver cirrhosis and chronic active hepatitis from other liver diseases with a sensitivity of 79%, specificity of 100%, and accuracy of 90%. Volumetric ratio measurements are useful in the diagnosis of cirrhosis and chronic active hepatitis.
Acute Disease↗
Computed tomography of adrenal metastases in hepatocellular carcinoma. Report of four cases.
Four patients with adrenal metastases from hepatocellular carcinoma (HCC) diagnosed with computed tomography are described. In three, the metastases showed a central area of low density due to tumor necrosis, irregular contrast enhancement, and a well-defined margin. They measured 8 cm or more in diameter. In one, the adrenal metastasis was at first a relatively small homogeneously solid mass, but later, when it grew larger, a central low density developed. Since the adrenal gland is the second most common site of metastasis from HCC at autopsy, a combination of an adrenal tumor and a liver tumor should suggest this possibility.
Adrenal Gland Neoplasms↗
Radiotherapy of dural arteriovenous malformation in the cavernous sinus.
Six patients with dural arteriovenous malformation (DAVM) in the cavernous sinus were treated by irradiation. The region of the abnormal vascular network was irradiated with a 10 MV linear accelerator; the total dose given ranged from 3,200 to 5,100 cGy (150-200 cGy per day, 750-1,000 cGy per week). All patients responded favorably to the treatment, with three of the six having no residual symptoms or signs of disease. Postradiotherapy angiography confirmed the complete disappearance of the shunts in two of the three patients. No significant side effects were observed during the follow-up period, which ranged from 10 months to four years. Radiotherapy is considered to be a useful treatment method for DAVM, especially for those patients having shunts from the meningeal branches of the internal carotid artery.
Aged↗
Aging factors and cardiovascular dimensions: a longitudinal study.
The effects of selected aging factors including body weight, blood pressure, and radiation dose on the cardiac and aortic arch transverse diameters, based on posteroanterior and lateral radiographs obtained 17 to 22 years apart were evaluated for 200 normal subjects. Increases in body weight and blood pressure caused increases in transverse cardiac diameter of 26% and 2%, respectively, but no appreciable effect on aortic arch transverse diameter. Radiation dose caused no significant effects. Effects of increases in body weight and blood pressure on cardiac and aortic arch transverse diameters with age ought not be overestimated in healthy adults.
Adult↗