Biomedical subjects
Publications and source records attributed to H Nakata.
We report a case of giant perineurial cell tumor, probably benign, with extensive degenerative changes. The secondary changes were reminiscent of those in giant ancient neurilemomas. To our knowledge, there has been no documentation of the imaging features in perineurioma. The MR findings of the present tumor, especially on T2-weighted images, correlated well with the histologic appearance.
A high-performance liquid chromatographic method using the column-switching technique was developed for the simultaneous determination of E3810 and its metabolites (M1-M4). An avidin column was used for in-line pretreatment to exclude plasma proteins, allowing direct injection of a large volume of plasma. A flavoprotein-conjugated chiral stationary phase in a gradient elution mode then gave baseline separation of E3810 and the four metabolites. The enantiomers of E3810 and M3 were also separated. The method is simple, rapid, accurate, and precise. Since no extraction procedure is employed, which might involve different recoveries of different metabolites, no internal standard is necessary. The method was applied to analyze E3810 and its metabolites in plasma after intravenous injection of the drug in beagle dogs.
RATIONALE AND OBJECTIVES: Optimal x-ray beam quality for chest computed radiography (CR) has not been determined. To investigate the optimal beam quality for chest CR, the authors measured the radiographic contrasts and compared the image quality of chest CR and screen-film (SF) radiographs using various x-ray tube voltages. METHODS: Chest CR and SF radiographs were obtained on a phantom lung and human volunteers with or without a variety of simulated lung opacities using various x-ray tube voltage levels. Exposures were set to maintain identical patient exposure doses for all images. The contrast between peripheral lung and rib or heart was measured on these images and the differences were compared. The quality of the images of each simulated opacity was evaluated by five radiologists using a five-point grading scale. RESULTS: Contrast between peripheral lung and rib or heart increased on CR images obtained by lowering the tube voltage from 140 to 80 kV, but the degree of increase was less than half the increase on SF images. The CR images of the simulated opacities obtained using a lower tube voltage were judged to be superior to those obtained with a higher tube voltage. Scattered radiation was reduced on CR images with a lower tube voltage. CONCLUSION: The image quality of chest CR was improved by using a lower tube voltage than that used for conventional SF chest radiography. Considering the problem of tube loading in clinical applications, a tube voltage of 100 kV is recommended for chest CR.
To investigate the therapeutic effect and incidence of side effects of recombinant interferon-alpha 2a (IFN-alpha) in chronic aggressive hepatitis C under stratification by administration mode, a study was conducted by assigning patients to either group A (daily consecutive administration of 9 million units (MU) IFN-alpha for 2 weeks and, thereafter, 3 MU intermittently 3 times weekly for 22 weeks) or group B (exclusively intermittent administration; 9 MU IFN-alpha twice weekly or 6 MU IFN-alpha thrice weekly for 24 weeks). The 28 patients in group A received IFN-alpha for 24 weeks up to a total dose of 324 MU and the 53 patients in group B received the same for 24 weeks up to a total dose of 432 MU. When recovery was defined as the absence of hepatitis C virus (HCV)-RNA 6 months after the completion of treatment, the rate of recovery for group A was 32.1% and that for group B was 37.7%, the latter being higher but without significance. Side effects in groups A and B consisted of leucopenia occupying 14.3 and 7.5%, respectively, and thrombocytopenia occupying 42.9 and 11.3%, respectively; group B exhibited lower values for both side effects. No difference was detected between these groups in other side effects, including pyrexia, generalized malaise, arthralgia or psilosis. Intermittent administration from the outset permitted shortened duration of hospitalization and earlier rehabilitation. Intermittent administration of INF-alpha is required when treating patients with chronic hepatitis C showing lower leucocyte or platelet counts.
RGM-1 is an epithelial cell line established from gastric mucosa of adult Wistar rats. In this study, we characterized this newly established cell line by Northern blot analysis. We also investigated deoxyribonucleic acid (DNA) synthesis and hexosamine production in RGM-1 by PGE2. Northern blot analysis did not detect any transcript of proton pump, gastrin receptor, histidine decarboxylase, somatostatin and pepsinogen 1, indicating the absence of characteristics of parietal, ECL, D and chief cells in RGM-1 cells. However, this periodic acid-Schiff (PAS)-positive cell line expressed prostaglandin EP4 receptor mRNA but not EP1 and EP3 receptor mRNAs. [3H]-thymidine incorporation into DNA of the cells was not increased by PGE2. In contrast, PGE2 increased hexosamine content in RGM-1 cells. These results suggest that RGM-1 may be a useful model of gastric mucosal cells and that PGE2 plays a role on mucin synthesis in RGM-1 cells possibly via EP4 receptors.
Most anemic patients with chronic renal failure have gastric mucosal lesions. However, these gastric lesions are often improved after the administration of recombinant human erythropoietin (rHuEPO). We have used the rat gastric mucosal cell line RGM-1, to examine the possibility that rHuEPO might directly stimulate the growth of gastric mucosal cells in vitro. Our results show that rHuEPO dose-dependently increased [3H]thymidine incorporation into RGM-1 cells and their expression of c-myc gene. In addition, 125I-rHuEPO specifically bound to RGM-1 cells, and moreover, erythropoietin receptor gene expression was detected by RT-PCR. We conclude that rHuEPO has a direct growth-promoting effect on RGM-1 cells, suggesting possible usefulness of rHuEPO administration for the treatment of gastric mucosal damage in patients with chronic renal failure.
PURPOSE: To test the clinical usefulness of computed radiography (CR) with a storage phosphor plate in upper gastrointestinal radiographic examinations, a newly devised phantom gastric mucosa was used. MATERIAL AND METHODS: Simulated small elevated and depressed lesions were created on a phantom gastric mucosa made from a styrofoam "plate". Twenty-four sets of each CR and screen-film radiographs (SR) were obtained using phototimed exposures. Receiver operating characteristic (ROC) study and visual ranking using these images were performed. RESULTS: There was no significant difference between the ROC curves of CR and SR. By visual ranking, CR was equal to or better than SR in most cases. In no case was SR definitely superior to CR. CONCLUSION: CR can be safely applied to upper gastrointestinal roentgenologic examinations.
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A female patient with idiopathic interstitial pneumonia (IIP) was admitted again 40 months after the diagnosis due to progression of clinical findings and increased activity of serum lactic dehydrogenase (LDH). Analysis of LDH isoenzyme disclosed a broad band between LDH4 and LDH5. Gel filtration and immunoelectrophoresis showed that immunoglobulin (Ig) G (kappa type) bound the LDH. With prednisolone and azathioprine, her symptoms and radiological findings improved concomitant with a decrease in the serum LDH activity. The LDH-IgG kappa complex disappeared in the circulation 14 months after initiation of the therapy. We report circulating LDH-Ig complex in a patient with IIP, which may be related to the disease progression of IIP.
BACKGROUND: Three-dimensional (3D) anatomic analysis was carried out, using helical computed tomography (helical CT), to evaluate its usefulness in two cases of large intrahepatic portosystemic venous shunt (IPSVS). METHODS: Case 1, a 74-year-old man with type-C hepatitis, underwent hepatic angiography to confirm suggested IPSVS of the left hepatic lobe in 1994. Case 2, a 62-year-old woman with liver cirrhosis associated with type-B hepatitis, was hospitalized for evaluation of suspected hepatocellular carcinoma in 1994. Hepatic angiography disclosed a large IPSVS in the right hepatic lobe. Retrospective evaluation of CT showed that the size of this shunt had increased over the 5 years 3D anatomic analysis was carried out, and the shunt vessels were clearly demonstrated. CONCLUSION: 3D anatomic analysis using helical CT was less invasive and useful for evaluating large IPSVS.
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To study the relationship between diaphragm weight and body composition, we measured fat body mass and lean body mass by dual-energy X-ray absorptiometry (XR-26, Norland), and weighed the diaphragms of patients at autopsy. The subjects were 22 patients with various diseases (13 men and 9 women, aged 72.6 +/- 9.5 years). In 8 of the patients, respiratory muscle strength was assessed with maximal pressure at the mouth. The diaphragm weight was 185.2 +/- 58.2 g and it correlated significantly with lean body mass (r = 0.77, r = 0.73, p < 0.01). Maximal inspiratory pressure at TLC correlated significantly with diaphragm weight. These results show that respiratory muscle strength is related to diaphragm weight and that analysis of body composition may be useful in assessing changes in the mass of the diaphragm.
We developed a radiology diagnostic reporting system compatible with a local area networked personal computer. A commercial package with a client-server database application was used for this customized program. With this system all diagnostic reports can be input from a client personal computer and saved on a server computer. This makes the retrieval of past diagnostic reports extremely easy. Use of this system in our department during the past 10 months, has simplified the management of diagnostic reports, reduced clerical work and saved storage space. It offers easy access for collecting clinical cases of interest since a database function for research purposes is also incorporated. This system using a personal computer and commercial application program is cheaper and more flexible than those that use a workstation base.
We investigated the prevalence of Helicobacter pylori infection by isolation of H. pylori and by antibody detection in the serum of Japanese children. The children were distributed into four groups by age: group I, under 1 year; group II, 1-5 years; group III, 6-11 years; and group IV, 12-15 years. For the isolation of H. pylori, gastric juice was obtained from 115 children from middle class families. In the 103 samples obtained from asymptomatic children, H. pylori was not isolated in any from group I. The isolation rate in groups II, III, and IV was 3% (1/32), 20% (5/25), and 75% (3/4), respectively. In symptomatic children, H. pylori was isolated only in group IV (66.7%). The antibody positive rate in group I, II, III, and IV was 13% (6/47), 10% (11/112), 18% (16/89), and 26% (11/43), respectively, in asymptomatic children. In group I, however, 4 of 25 samples (18%) were obtained from babies under 3 months of age; this result was regarded as reflecting maternal antibodies. Nineteen samples were obtained from children with hepatitis A who lived in Nanki hospital for handicapped children, where hygiere was poor. The antibody positive rate in this population was 60% (3/5) in group III and 90% (9/10) in group IV. These results suggest that H. pylori infection in Japanese children is related to age and hygiene conditions. The antibody positive rate was similar to that reported in other countries.
A 43-year-old woman with a history of Sjögren's syndrome was admitted to our hospital because of dyspnea due to anemia. Her chest X ray film on admission revealed an anterior mediastinal tumor. We diagnosed this tumor as a thymoma based on a chest CT scan and magnetic resonance imaging. Because the latter indicated that the thymoma may have involved the mediastinal great vessels, preoperative chemotherapy with cisplatin, doxorubicin hydrochloride, vincristine sulfate and cyclophosphamide. Thereafter the tumor was successfully resected along with part of the right pleura. Thymoma as a complication of Sjögren's syndrome is rare. Here we also discuss the treatment of thymoma and the combination of these two diseases.
An enantioselective high-performance liquid chromatographic method for the determination of E3810, a new anti-ulcer agent, in Beagle dog plasma and rat plasma has been developed. After extraction from plasma with ethyl acetate, E3810 enantiomers were measured by reversed-phase high-performance liquid chromatography on a Chiralcel OD-R column. The enantiomers were detected by ultraviolet absorbance detection at 290 nm. The recoveries of E3810 enantiomers and internal standard were greater than 91%. The calibration curves were linear from 0.03 to 20 micrograms/ml for Beagle dog plasma and from 0.1 to 100 micrograms/ml for rat plasma. The limits of quantification of both enantiomers were 0.03 micrograms/ml for Beagle dog plasma and 0.1 micrograms/ml for rat plasma. The intra- and inter-day accuracy and precision data showed good reproducibility of the method. The assay was applied for the analysis of E3810 enantiomers in plasma after intravenous administration of racemic E3810 to Beagle dogs and rats. This method should be very useful for enantioselective pharmacokinetic studies of E3810.
The effect of wortmannin, which inhibits phosphatidylinositol 3-kinase (PI 3-kinase), on adipocytic differentiation of 3T3-L1 cells was examined. The extent of differentiation was evaluated by the staining of adipocytes with Oil Red O and measurement of glycerol 3-phosphate dehydrogenase (GPDH) activity. Wortmannin, at over 100 nM, significantly inhibited adipogenesis of cells treated with isobutyl-methylxanthine, dexamethasone, and insulin with an IC50 value about 50 nM. These results suggest that PI 3-kinase plays a role in adipocytic differentiation of 3T3-L1 cells.
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.