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Biomedical subjects

R Morita

Publications and source records attributed to R Morita.

At least 19 recordsLinked to original sources
PubMed1992

[Evaluation of aortic distensibility using cine MR imaging].

Regional aortic distensibility was measured noninvasively using cine MR imaging to determine whether it correlates with aging or risk of coronary artery disease (CAD). Twenty-two patients with CAD confirmed by angiography and 33 without CAD underwent cine MR imaging. Thirty-two sequential images were obtained in one cardiac cycle. The cross sectional area of the descending thoracic aorta was measured on both diastolic (A) and systolic (A') images. Aortic distensibility (A.D.) was calculated from the following equation: A.D. = (A'-A)/A/delta P. (delta P represents pulse pressure). Results of a simple regression analysis showed that decreased regional aortic distensibility was significantly correlated with the age of the patients (r = -0.762, p less than 0.005). In addition, the parameter was lower in patients with CAD than those without CAD (p less than 0.05). In conclusion, regional aortic distensibility derived from cine MR imaging is a useful parameter to evaluate not only aging but also pathological atherosclerosis of the aorta. In addition, this parameter might have some potential to evaluate the prediction of CAD in patients with normal serum cholesterol.

Adolescent↗
PubMed1992

[Determination of vertebral fracture threshold by measuring bone mineral content in the lumbar vertebrae].

Bone mineral density (BMD) in the lumbar vertebrae (L2-L4) was assessed by dual energy X-ray absorptiometry (DEXA: QDR-1000), and the values obtained were compared with the frequency of vertebral fracture as assessed by spinal X-ray photographs. Patients with spondylosis or scoliosis, which affect BMD values, were excluded from the study. An essentially linear correlation was observed between the frequency of vertebral fracture and lumbar BMD values: no vertebral fractures were observed in those whose BMD more than 0.8 g/cm2, whereas the frequency of fracture was 100% in patients whose BMD was less than 0.45 g/cm2. Thus, measurement of lumbar vertebrae by DEXA would be very useful in predicting vertebral fractures.

Absorptiometry, Photon↗
PubMed1992

Angiographic demonstration of no-flow anatomical patency of internal thoracic-coronary artery bypass grafts.

To clarify the no-flow situation of the stringlike internal thoracic artery graft, we angiographically examined such grafts by temporarily occluding the recipient coronary artery with a percutaneous transluminal coronary angioplasty balloon and were able to reveal anatomical patency of the internal thoracic artery graft in 2 patients 1 year and 3 years after the operations. Thus, there is a possibility that internal thoracic artery grafts may continuously maintain anatomical patency even under no-flow situations just like nonfunctioning collateral vessels and may function properly later as a graft when the native coronary flow decreases. Also, this angiographic technique can be a new method for detecting anatomical patency of no-flow and functionally closed internal thoracic artery grafts.

Anastomosis, Surgical↗
PubMed1992

Pulmonary metastatic nodules: CT-pathologic correlation.

To elucidate the characteristics of pulmonary metastatic nodules on high-resolution computed tomographic (HRCT) scans, a correlative computed tomographic (CT)-pathologic study was performed with five human lungs after autopsy. The relationship of metastatic nodules to pulmonary vessels was studied with HRCT scans, radiographs of the specimen, and stereomicroscopic study in 264 nodules 0.6-9.0 mm in diameter. On radiographs and stereomicroscopic images, 190 small nodules (less than 3 mm in diameter) were in contact with the pulmonary lobule on the central bronchovascular bundles (n = 33 [17.4%]), located between the central bronchovascular bundle and the perilobular structure (n = 127 [66.8%]), or attached to perilobular structures (n = 30 [15.8%]). On HRCT scans, 21 small nodules (11.1%) were located on the central bronchovascular bundle; 130 small nodules (68.4%), between the central bronchovascular bundle and the perilobular structure; and 39 small nodules (20.5%), on the perilobular structure. On radiographs and stereomicroscopic images, 43 of 74 large nodules (greater than 3 mm in diameter) (58%) compressed both bronchovascular bundles and perilobular structures. The central bronchovascular bundle was invaded in only 13 large nodules (18%).

Humans↗
PubMed1992

Formation of a transfer product from stevioside by the cultures of Actinomycete.

An Actinomycete, strain K-128, which was isolated from soil, formed a transfer product when the strain was cultured in a medium containing both stevioside and curdlan. The transfer product in culture broth was separated by DIAION HP-20 column and TOYOPEARL HW-40F column chromatographies. From structural studies, the transfer product was identified as C13-O-beta-6(2)-beta-glucosylsophorosyl-C19-O-beta-glucopyranosyl steviol. This product was the first to be obtained by a culture of an Actinomycete.

Actinomyces↗
PubMed1992

[Gianturco expandable metallic stents in the treatment of superior vena cava syndrome caused by lung cancer].

Treatment of superior vena cava syndrome (SVCS) caused by advanced lung cancer is still controversial. We inserted Gianturco expandable metallic stents (GEMS) in 5 patients with SVCS due to the extension of lung cancer. GEMSs were introduced intravenously through the catheter after intraluminal balloon dilation of the stenotic sites. SVCS was successfully and easily relieved by this method without any significant complication. GEMS placement seems to be a useful alternative to bypass grafting procedure for the treatment of SVCS.

Adult↗
PubMed1992

[Effect of long-term administration of antisecretary drugs on rat gastric histamine synthesis and acid secretion--compare with omeprazole and cimetidine].

To investigate the effect of 6 weeks administration of proton pump inhibitor (omeprazole) and H2-receptor antagonist (cimetidine) on gastric histamine synthesis and acid secretion, we studied experimentally in the rat stomach. Then gastric mucosal histamine concentration, histidine decarboxylase (HDC) activity and serum gastrin concentration, and HDC positive cell number were examined in time-course. The 6 weeks administration of omeprazole caused more increase of HDC positive cells than cimetidine. After cessation of administration with omeprazole, high plasma gastrin level immediately reduced. However the increase of gastric mucosal HDC activity and histamine concentration were prolonged, compared with cimetidine. These findings suggest to affect differently between omeprazole and cimetidine on gastric acid secretion after cessation of long-term treatment.

Animals↗
PubMed1992

[Late results of coronary artery bypass grafting with the internal thoracic artery].

Between November 1981 and December 1991, 755 patients underwent isolated coronary artery bypass grafting. We compared postoperative events, graft patency and survival rates of the patients who received at least one internal thoracic artery graft (n = 517) with those of the patients who had only saphenous vein bypass grafts (n = 238). No significant difference was found between the 2 groups in patient's age at the operation, female ratio and the incidence of emergency operation. The operative mortality was not significantly different in either group. Graft patency was better for internal thoracic artery grafts than for SVG (ITA grafts 97.1%, SVG 85.6% p less than 0.0001). Graft-LAD patency rate was also better for ITA grafts than for SVG (ITA grafts 97.7%, SVG 86.8%, p less than 0.0001). The incidence of late cardiac events (late cardiac death, reoperation, myocardial infarction) is lower in patients with ITA. Furthermore, patients who received ITA grafts had a better survival rate at 8 years (91.1% versus 85.3%, p = 0.048) than those who had vein bypass grafts alone. We conclude that the use of ITA grafts enhances the long-term benefits including long-term survival rate. This is the first observation in Japanese population.

Adult↗
PubMed1992

A quantitative study of postoperative luminal narrowing of the internal thoracic artery graft in coronary artery bypass surgery.

We used quantitative angiography to determine the postoperative diameter of the internal thoracic artery graft at the point close to the anastomosed site in 147 patients who received the graft for the left anterior descending coronary artery. We performed generalized multiple linear regression analysis (Type I quantification method) to assess the effects of the following factors on the internal thoracic artery graft diameter: age, gender, time of angiography, laterality of the internal thoracic artery used, presence of an undivided major side branch of the internal thoracic artery, presence of a saphenous vein graft having blood flow competition with an internal thoracic artery graft, presence of distal stenosis of the recipient left anterior descending coronary artery, severity of postoperative left anterior descending coronary artery stenosis, and presence of coronary risk factors. The standardized category scores for 25% left anterior descending coronary artery stenosis, 50% left anterior descending coronary artery stenosis, and presence of a saphenous vein graft having blood flow competition with an internal thoracic artery graft were -1.418, -0.767 and -0.622, respectively. Thus, the internal thoracic artery diameter was smaller in patients with well-preserved flow of the recipient coronary artery. The internal thoracic artery diameter had a particularly strong correlation with the degree of left anterior descending coronary artery stenosis (partial correlation coefficient: 0.670). The other factors seemed to have little or no correlation with the postoperative internal thoracic artery diameter. With the criterion that the internal thoracic artery diameter below 1.0 mm represents the "string sign" of internal thoracic artery graft, this phenomenon was observed in nine patients (6.1%). In all of these patients, left anterior descending coronary artery flow was well-preserved, and no ischemia was disclosed in the left anterior descending coronary artery-perfused area. These results indicate that internal thoracic artery grafts have flow adaptability responding to the flow demand of the recipient coronary artery and that the string sign of internal thoracic artery grafts is mainly an outcome of its physiologic characteristics.

Adult↗
PubMed1992

[Aortic valve replacement with fresh or cryopreserved aortic allograft--initial experience in Japan].

Aortic allograft valves were harvested from non-infected (bacterial or viral) cadavers within 24 hours of death with a family consent, and were sterilized by 4 degrees C antibiotic solution for 48 hours. Then, the allograft was preserved in the 4 degrees C nutrient medium (fresh; TC-199, calf serum and HEPES buffer) or in liquid nitrogen (-196 degrees C) after freezing to -80 degrees C by a programmed freezer. 10% dimethylsulfoxide (DMSO) was used for cryopreservation. Following germ-free confirmation, aortic allograft valves were implanted in 5 patients having aortic regurgitation with good results. Three fresh and two cryopreserved allograft valves were used. Although the follow-up term is very short (maximum 1 year) at the present time, the valve function is quite satisfactory, confirmed by cardiac catheterization and echocardiography. This is the first report in Japan with regard to cryopreservation of allograft valves and clinical use of fresh or cryopreserved valves. We believe that realization and progress of allograft preservation by cryo-technique and establishment of the tissue bank are important for the development of cardiovascular surgery in Japan.

Adult↗
PubMed1992

[Tumor suppressor genes associated with development of human renal cell carcinoma].

Several rodent studies based on molecular biology have suggested that accumulation of genetic alterations in cancer-associated genes is required to convert a normal cell into a malignant cell. Activation of oncogenes and inactivation of tumor suppressor genes appear to be involved in carcinogenesis. In renal cell carcinomas, we have recently implied that the presence of tumor suppressor genes at chromosome 3p13-14.3 and 21.3, the regions where are also commonly deleted in adenocarcinoma of the lung; at chromosome 5q21, the region where the MCC (mutated in colorectal cancer) gene and APC (adenomatous polyposis coli) gene are located; at chromosome 6q27; and at 10q 21-23. We have also indicated that genes on 3p is probably important for development of RCCs and genes on 5q, 6q, and 10q may be associated with progression of RCCs.

Carcinoma, Renal Cell↗
PubMed1992

[A case of traumatic rupture of the pericardium].

A 59-year-old man was admitted to our hospital because of compression fracture of the lumbar spine and pubic bone fracture following fall from a ladder. On admission the only a little left pleural effusion in the thorax was noted. Two days later, x-ray film of the chest revealed massive left pleural effusion. Under the diagnosis of left hemothorax, left thoracotomy was performed. Then we found incidentally that the left pericardium had ruptured longitudinally over the length. Herniation of the heart was not developed. The ruptured pericardium was repaired using Teflon mesh.

Humans↗
PubMed1992

[Use of airway stent subsequent to endoscopic Nd-YAG laser treatment in central airway obstruction].

Ten cases of central airway obstruction mainly caused by extrinsic compression due to the growth of extratracheal malignant tumors or longitudinal extension of tracheal adenoid cystic carcinomas, underwent palliative intubation subsequent to endoscopic Nd-YAG laser treatment. Mean length of the severe stenosis in these cases was 4.4 cm (3-7 cm). Sole application of endoscopic Nd-YAG laser to the stenosis failed relief of the symptom and an immediate palliative intubation was recommended. Mean time of the temporary intubation was 7 days (4-11 days). Airway was maintained by this intubation and also retained enough after extubation. Therefore, it seemed that, in a palliative treatment of the central airway severe stenosis, usefulness of the combination management of Nd-YAG laser with following temporary intubation was revealed. However, in order to maintain the airway for recurrence of the obstruction, use of indwelling airway stents seemed a better application. The longest period of follow-up in the cases treated by indwelling airway stents was 6 months and one of the cases is a now in comfortable state.

Adult↗
PubMed1991

Common regions of deletion on chromosomes 5q, 6q, and 10q in renal cell carcinoma.

Relatively frequent losses of heterozygosity on chromosomes 5q, 6q, and 10q, in addition to loss of heterozygosity on the short arm of chromosome 3, have been observed in renal cell carcinomas. As the first step toward isolation of tumor suppressor genes on these three chromosomal arms, we used six restriction fragment length polymorphism markers for 5q, nine for 6q, and eight for 10q to identify regions commonly deleted in a panel of 64 renal cell carcinomas. Allelic losses were common at chromosome 5q21, the region where the MCC (mutated in colorectal cancer) gene was recently identified; at chromosome 6q27; and at chromosome 10q21-23. Furthermore, as association was observed between accumulation of allelic losses on these three chromosomal arms and progression of tumors. Loss of heterozygosity on chromosome 5 showed a correlation with the histopathological grade of a given tumor and the incidence of distant metastasis.

Blotting, Southern↗
PubMed1991

Allelotype of human ovarian cancer.

In order to determine which chromosome(s) carries a tumor suppressor gene(s) for human ovarian cancer, we examined loss of heterozygosity in 37 tumors with a set of polymorphic DNA markers which cover each autosomal chromosome arm partially. Frequent losses were observed in chromosomes 4p (42%), 6p (50%), 7p (43%), 8q (31%), 12p (38%), 12q (33%), 16p (33%), 16q (38%), 17p (46%), 17q (39%), and 19p (34%). In addition to these chromosomes, frequent losses of alleles on chromosomes 6q, 13q, and 19q were observed uniquely in serous and serous papillary cystadenocarcinomas; loss of heterozygosity was detected only rarely on these chromosomal arms in nonserous types of tumors. The average (0.12) of fractional allelic loss seen in mucinous cystadenocarcinoma, which usually has a better prognosis than other types, was much lower than that of other tumor phenotypes including serous cystadenocarcinoma (0.31) and clear cell carcinoma (0.20). These results suggested that (a) a large number of tumor suppressor genes might play a role in ovarian cancer, (b) losses of alleles in different chromosomal regions could account for differences in histopathological features and/or prognoses among patients, and (c) this kind of analysis can contribute to an improved understanding of tumor development and/or progression in human ovarian cancer.

Adenocarcinoma↗
PubMed1991

A detailed deletion mapping of the short arm of chromosome 3 in sporadic renal cell carcinoma.

A detailed analysis of loss of heterozygosity in 40 sporadic renal cell carcinomas was performed by using 30 restriction fragment length polymorphism markers which were mapped on the short arm of chromosome 3. A total of 30 of 38 informative cases (79%) showed loss of heterozygosity at one or more loci. Two commonly deleted regions have been identified at 3p13-14.3 and 3p21.3. One of them (at 3p13-14.3) spans the breakpoint of the (3;8) translocation in hereditary renal cell carcinoma previously reported (A. J. Cohen et al., N. Engl. J. Med., 301:592-595, 1979). The second common region of deletion at chromosome 3p21.3 encompasses D3F15S2, at which a high incidence of loss of heterzygosity in renal cell carcinoma has been reported. In addition to the gene at 3p25 being responsible for the hereditary type of renal cell carcinoma in patients with von Hippel-Lindau disease, our results suggest that at least two tumor suppressor genes for sporadic renal cell carcinoma exist on the short arm of chromosome 3.

Carcinoma, Renal Cell↗
PubMed1991

Allelotype of renal cell carcinoma.

Several recent studies based on restriction fragment length polymorphism analysis have supported the concept that the accumulation of multiple genetic alterations converts a normal cell to a malignant cell. Activation of oncogenes and/or inactivation of tumor suppressor genes have been observed during tumor progression in colorectal cancer, lung cancer, and breast cancer. To investigate the possibility that multiple genes are altered during the progression of renal cell carcinoma, we have used restriction fragment length polymorphism markers throughout the genome to test for loss of heterozygosity in 38 renal cell carcinomas. Nearly 64% of the tumors had lost heterozygosity on the short arm of chromosome 3. We also observed loss of heterozygosity averaging about 30% at informative loci on six other chromosomal arms (chromosomes 5q, 6q, 10q, 11q, 17p, and 19p). These results lead us to suspect the existence of several tumor suppressor genes associated with carcinogenesis of renal cell carcinoma.

Carcinoma, Renal Cell↗