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Biomedical subjects

Y Murashima

Publications and source records attributed to Y Murashima.

At least 19 recordsLinked to original sources
PubMed2002

Guided bone regeneration (GBR) using membranes and calcium sulphate after apicectomy: a comparative histomorphometrical study.

AIM: The purpose of the present study was to evaluate the effects of resorbable and non-resorbable membranes, and calcium sulphate on bone regeneration in osseous defects in conjunction with apicectomy. METHODOLOGY: The mandibular third and fourth premolars of 12 beagle dogs were root treated, and apicectomies were performed. The osseous defects were divided randomly into five groups. In groups A, B and C the osseous defects were covered with e-PTFE membranes, PLGA membranes, and collagen membranes, respectively. In group D, defects were filled with calcium sulphate. Nothing was used in group E, which served as controls. The dogs were sacrificed 4, 8, and 16 weeks after the surgery. Undemineralized sections were obtained and evaluated histomorphometrically. RESULTS: Newly formed cortical bone had closed the defect in the cortical plate in all groups at 16 weeks. The degree of concavity of the new cortical bone at 16 weeks in groups A and D was significantly less than in group B (P < 0.01). The percentage of regenerated bone in group A was significantly greater than in groups B (P < 0.01), C (P < 0.05) and E (P < 0.05). In group D, it was significantly greater than in groups B (P < 0.01) and E (P < 0.05). CONCLUSIONS: The data suggests that e-PTFE membrane is more effective compared to resorbable membranes and controls for bone regeneration after apicectomy, and that calcium sulphate could be substituted for e-PTFE membrane.

Absorbable Implants↗
PubMed2002

Calcium sulphate as a bone substitute for various osseous defects in conjunction with apicectomy.

AIM: The purpose of this study was to investigate the effect of calcium sulphate on various osseous defects when used in conjunction with apicectomy. METHODOLOGY: Mandibular third and fourth premolars of 11 beagle dogs were used. After root-canal treatment and apicectomy, three types of osseous defects were prepared on both sides of the mandible as follows: type 1, osseous defect communicating with the gingival sulcus: type 2, large osseous defect including two roots; type 3, 'through and through' osseous defect. The experimental side was allocated randomly, and the osseous defects were filled with medical grade calcium sulphate. The defects on the opposite side were left unfilled as controls. The dogs were sacrificed at 8 and 16 weeks postoperatively. Undemineralized sections were obtained and examined histomorphometrically. RESULTS: In type 1 defects, bone was not observed on the buccal side of the root on either experimental or control side at 8 and 16 weeks. In both type 2 and 3 defects, bone volume/tissue volume (BV/TV) values on the experimental side were significantly higher than those on the control side (P < 0.01), and mineral apposition rate (MAR) values on the experimental side were significantly higher than those on the control side (P < 0.01). CONCLUSIONS: The use of calcium sulphate was effective in bone regeneration on both large osseous defects and 'through and through' osseous defects. It was less effective in osseous defects communicating with the gingival sulcus.

Alveolar Bone Loss↗
PubMed1997

Age-related appearance of dystrophic axon terminals in cerebellar and vestibular nuclei of Mongolian gerbils.

In the brains of 360-day-old Mongolian gerbils, numerous swellings immunoreactive to anti-neurofilament antibody were observed in cerebellar and vestibular nuclei. The number of these swellings was the same in two gerbil strains with different susceptibility to spontaneous motor seizures by various stimuli, but much more numerous in gerbils as compared with the 360-day-old Slc:Wistar rats. Such swellings were only occasionally found before 60 days of age in gerbils, but they increased in number about fivefold from 60 to 180 days of age and about quadruple from 180 to 360 days of age. Electron microscopic observation showed that these swellings were dystrophic axon terminals (DATs) whose cytoplasms were occupied with large bundles of neurofilaments, numerous vesicular structures containing membranous and/or granular materials, and many rod-shaped mitochondria. Additionally, other types of DATs displaying degenerative changes of cytoplasmic organelles were observed. ACPase cytochemistry showed that the vesicular structures in the DATs contained ACPase and released it into the cytoplasm.

Aging↗
PubMed1996

Altered axon terminals containing concentric lamellar bodies of cerebellar Purkinje cells in Mongolian gerbil.

Altered axon terminals containing concentric lamellar bodies were observed in cerebellar and vestibular nuclei of the Mongolian gerbil. The terminals increased in number from 30 days of age onward, and reached about tenfold at 360 days. The numbers were the same in two gerbil strains with different susceptibility to spontaneous motor seizures by various stimuli, but about threefold those in Slc:Wistar rat.

Animals↗
PubMed1991

Clinical efficacy of sucralfate in the treatment of gastric ulcer.

We performed a randomized, single-blind study in Japan to investigate the efficacy and safety of two dosage regimens of sucralfate granules, 2 g, twice daily (b.i.d. group, n = 30) and 1 g, 4 times daily (q.i.d. group, n = 27), on ulcer healing in 57 patients with endoscopically proven gastric ulcer. Endoscopy was performed after 4 weeks and, if complete healing was not achieved, again after an additional 4 weeks. Of 57 patients, 11 were excluded from the statistical analysis because of protocol violation (six in b.i.d. group, five in q.i.d. group). Of 46 patients eligible for the analysis of healing rates, four patients in the b.i.d. group (all at 8 weeks) and five patients in the q.i.d. group (two at 4 weeks and three at 8 weeks) were withdrawn due to patients' inconvenience. As the possibility that the withdrawals were due to the treatment failures could not be denied, we used the Kaplan-Meier method and generalized Wilcoxon test/logrank test for the calculation and evaluation of healing rates in this study, respectively. Healing rates at 4 and 8 weeks were 50% and 94% in the b.i.d. group and 35% and 68% in the q.i.d. group. There was no significant difference in healing rates between the groups. No serious adverse effect was observed in either group. These results suggest that the 2 g b.i.d. dose of sucralfate in granule form is at least as effective as the conventional dose of 1 g q.i.d. in the treatment of active gastric ulcers and could lead to better patient compliance.

Administration, Oral↗
PubMed1990

Evaluation of cardiac tissue from two-dimensional echocardiogram: analysis of gray level and its distribution.

Two-dimensional echocardiograms of parasternal long-axis view were recorded and the mean echo intensity and its distribution in the interventricular septum were examined for the purpose of inferring myocardial tissue. Six healthy subjects (N), 29 with left ventricular hypertrophy (LVH), and 12 with old anteroseptal myocardial infarctions (MI) were used in the study. Settings for gain control were adjusted in the constant manner. Data were recorded on a Video tape recorder, with analog data converted to digital signals, subjected to a low-pass filtering, and then analyzed by a Computer tomography image processor. The region of interest was set within the interventricular septum, and a mean relative echo intensity and its histogram (number of pixels showing different echo intensity) was evaluated. The histogram patterns were examined and the parameter for skewness, which shows asymmetrical characteristics, and the parameter for kurtosis, which shows degree of peakedness of distribution, were calculated. Relative echo intensity was found to increase in the order MI greater than LVH greater than N. Histograms showed the majority of pixels were concentrated at the low echo intensity level in the normal group, while pixels were distributed in a relatively gentle slope around the mean value in the LVH group. Many pixels were in the high intensity levels in the MI group, although the rest were dispersed throughout various intensities including low level. The differences are thought to be related to the extent and density of fibrosis. Analysis of two-dimensional echocardiographic echo intensity and distribution may be useful in characterizing myocardial tissues.

Adult↗
PubMed1990

[Peroral endoscopical diagnosis for the early stage of cancer in bilio-pancreatic system].

PCPS (peroral cholangio-pancreatoscopy), a modality of mother and baby scope systems, was very useful for the diagnoses of bile duct tumors. The endoscopical findings and pathological findings obtained on the biopsy specimen collected under the direct view were valuable. For the diagnosis of pancreatic diseases, PMPS (peroral micro-pancreatoscopy), in which ultrathin quartz fibers are used for the baby scope, was useful. By this method, we could observe the inside of the pancreatic duct through an untreated normal papilla. This is very helpful for endoscopical diagnosis of small pancreatic cancers. EUS (endoscopic ultrasonography) was also a useful method for the diagnosis of small pancreatic cancers. EUS could draw the three layers of the common bile duct and gall bladder walls, and could distinguish a cholesterol polyp from a non-cholesterolic one. Combined application of these methods will aid in the discovery of early stages of cancers in the bilio-pancreatic system.

Biliary Tract Neoplasms↗
PubMed1988

[Analysis of myocardial texture in two-dimensional echocardiographic images].

To evaluate tissue changes, we studied myocardial texture using two-dimensional echocardiographic images. We investigated 19 normal subjects, 28 patients with left ventricular hypertrophy, and 12 patients with old anteroseptal myocardial infarction of longer than one year duration. Using 2.5, 3.5, and 5.0 MHz transducers, two-dimensional echocardiograms in the parasternal long-axis view were obtained, and the textures of the interventricular septal images were classified in three types; type I, with a nearly uniformly speckled or echolucent appearances; type II, with multiple, discrete, small (2 to 4 mm) highly refractile echoes; type III, with larger highly refractile echoes (greater than 4 mm) appearing as a cluster of broad patches or band-like echoes. Normal subjects belonged to the type I texture, while many with left ventricular hypertrophy belonged to the type II category. Type III was often observed in patients with old anteroseptal infarction. Using a transducer of higher frequency, there tended to be a shift from type II to I or type III to II. In phantom experiments using carbolandam granules instead of the myocardium, the echocardiographic texture became rough when the phantom was farther from the transducer or the transducer was of low frequency. We suggest that the texture in two-dimensional images may reflect myocardial tissue changes, when other factors including the apparatus and technique remain stable.

Adult↗
PubMed1988

[Endoscopic treatment of early upper gastrointestinal carcinoma--high-frequency-current polypectomy, laser, and microwave coagulation procedures].

The authors have been treating early gastric carcinoma endoscopically by high-frequency-current polypectomy since 1976, by microwave coagulation since 1982, and by laser coagulation since 1983. In order to achieve absolute curability of early carcinoma, we recommend that polypectomy be performed first, whenever possible. The reason for this is that the resected polypectomised tissue enables a decision to be made as to whether further treatment is necessary, after histopathological examination of the specimen. Otherwise, cases in which snaring is impossible, such as flat or depressed carcinomas of markedly small or large size, should be treated by microwave and/or laser coagulation. In total, we have experienced 92 lesions (83 cases) of early gastric carcinoma treated by all of above 3 methods, and we currently have 5 cases showing more than 5-year survival. Among these, type II a early carcinomas less than 10mm in diameter accounted for the majority; on the other hand, there were 11 type II c cases, also with tumors less than 10mm in diameter. Referring to our surgical data, type II c (without ulcer nor lymph node metastases) less than 5mm in size is limited to the mucosa in 100% of cases, and of 6-10mm in size in 85%. We therefore propose that type II c tumors less than 10mm in size should be treated endoscopically, as well as type II a tumors of the same size. In order to determine the depth of carcinomatous invasion, endoscopic ultrasonography (EUS) is effective. The diagnostic accuracy for Ul(-) early carcinoma is almost 100%, but for Ul(+) cases EUS is not so accurate. Further studies and improvements of EUS are thus needed.

Gastroscopy↗
PubMed1987

[Two-dimensional echocardiographic echo intensity distribution by histographic analysis].

To assess myocardial tissue changes, the distribution of echo intensities of two-dimensional echocardiograms was analyzed using a histogram. The materials were obtained from six normal subjects (N), 29 patients with left ventricular hypertrophy (LVH), and 12 patients one year or more after the onset of anteroseptal myocardial infarction (MI). A transducer with a central frequency of 2.3 MHz was used. Scanner receiver settings, including sensitivity-time control, were kept constant for all subjects. The parasternal long-axis image was digitized and computer-processed. The region of interest was located within the interventricular septum. The mean echo intensity and its distribution were studied. The shape of the histogram was evaluated for skewness and kurtosis. Relative echo intensity: N = 0.23 +/- 0.07 (mean +/- SD) less than LVH = 0.58 +/- 0.18 less than MI = 1.07 +/- 0.25 (p less than 0.01). Skewness: N = 1.58 +/- 0.63 greater than LVH = 0.60 +/- 0.61 greater than MI = -0.14 +/- 0.43 (p less than 0.01). Kurtosis: N = 18.0 +/- 7.3 greater than LVH = 10.5 +/- 3.3 greater than MI = 7.7 +/- 0.9 (p less than 0.01). These differences may closely relate to an increase in collagen fiber content. Consequently, analysis of the myocardial echo intensity distribution, in addition to mean echo intensities, may become a clinically useful approach for identifying myocardial tissue changes.

Adult↗
PubMed1987

[Ultrasonic tissue characterization in diagnosing myocardial infarction].

To evaluate myocardial tissue changes using two-dimensional (2D) echocardiography, several approaches were attempted. 1. Quantitative evaluation of the myocardial echo intensity by computerized image processing in patients with old anteroseptal myocardial infarction: 2D echocardiograms of the parasternal long-axis view were converted to digital images to measure the echo intensity of the regions of interest (ROI) placed in the interventricular septum (IVS), the left ventricular posterior wall (LVPW), the left ventricular cavity, and the pericardium. The mean value of the echo intensity was compared with that of the pericardium (maximum echo intensity) and of the left ventricular cavity as the minimum. In 12 normal subjects, the relative echo intensity of the IVS was 0.40 +/- 0.05 (mean +/- SE), whereas it was 0.71 +/- 0.06 in 11 patients with old MI (p less than 0.001). Color display facilitated the visual recognition of the numerical differences in echo intensities. 2. Evaluation of the myocardial echo intensity in acute phase of myocardial infarction: In nine normal elderly persons, the relative echo intensity of IVS was 0.29 +/- 0.14, and there was no significant change in the early stage (three to seven days) of acute infarction (0.31 +/- 0.14). Two weeks later, however, a significant increase was noted (0.61 +/- 0.10) (p less than 0.01), probably due to an increase in collagen fibers. 3. Changes of the myocardial echo intensity in acute myocardial ischemia: Two-dimensional echocardiograms were recorded in nine open-chest dogs using 3 and 5 MHz transducers before and 10 min, 1 hr, 3 hrs, and 6 hrs after coronary artery ligation. With the 5 MHz transducer, the echo intensity of the ischemic myocardium was decreased after 10 min and was remarkable after 1 hr (0.24 +/- 0.08), and restored in six hrs. These changes could not be detected using the 3 MHz transducer. 4. An in vitro study for assessment of ultrasonic attenuation in the canine infarcted myocardium: The frequency dependency of ultrasonic attenuation of the resected canine myocardium in the frequency region of 2 MHz to 7 MHz was estimated one and two weeks after coronary artery ligation. The distributions of attenuation characteristics were nearly consistent with those of collagen contents determined histologically. In conclusion, we demonstrated that acute and chronic ischemia of the myocardium influences the transmission and reflection of ultrasound. By applying this property, ultrasonic tissue characterization may become a useful tool for detecting myocardial ischemia in the near future.

Adult↗
PubMed1987

[A report on the epidemiology and the clinical features of the patients with chronic pancreatitis in Hokkaido District].

We carried out through questionnaires the second survey on the epidemiology and the clinical features of chronic pancreatitis in Hokkaido district. Chronic pancreatitis was diagnosed in 258 patients in 19 hospitals during the period April 1977 to December 1984. The ratio of male cases to females was 2.7:1.0 and the average age was 53.9. Alcoholic abuse, observed in 55% of the patients, was a main causative factor. A half of the patients was diagnosed on the basis of pancreatogram and/or image of the pancreas (ultrasonogram and computed tomogram). The incidence of chronic pancreatitis in the second survey was about fourfold over that diagnosed during the period January 1970 to March 1977 in the first survey. Such an increasing number of the patients with chronic pancreatitis in Hokkaido district was considered to be resulted from the difference between two surveys in epidemiological aspects and diagnostic criteria. The proportion of female patients and alcoholic patients was calculated to be increasing. The frequency of the patients diagnosed in a relatively early stage was supposed to be also increasing, because in the second survey a new item (pancreatogram, ultrasonogram and computed tomogram) was added to the diagnostic criteria (histological evidence, pancreatic calcification and definitive disturbance of exocrine pancreatic function) in the first survey. Based on whether alcoholic abuse was causative factor or not, the patients were divided into two groups and the clinical manifestations of both groups were compared.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Quantitative evaluation and color display of echo intensity by two-dimensional echocardiography].

To assess myocardial tissue changes by two-dimensional echocardiography, quantitative evaluation and color display of the echo intensity were attempted using computerized image processing. The materials consisted of 11 patients with old anteroseptal myocardial infarction one year or more after the onset (OMI), and 12 normal subjects. Two-dimensional echocardiograms in the parasternal long-axis view were obtained using a commercially-available phased-array sector scanner. Scanner receiver settings including sensitivity-time control were maintained constant in all subjects. Images were recorded on the U-matic tape using a video tape recorder, then stop-frame end-diastolic images were converted to digital images. To measure echo intensity, regions of interest (ROI) were placed in the interventricular septum (IVS), the left ventricular posterior wall (LVPW), the left ventricular cavity, and the pericardium. The mean value of the echo intensities was determined for each ROI. Then, the relative echo intensity of the IVS or LVPW was calculated using the mean value of the pericardium as the maximum echo intensity, and the mean value of the left ventricular cavity as the minimum echo intensity. In normal subjects, the relative echo intensity of the IVS was 0.40 +/- 0.05 (mean +/- SE) and that of the LVPW was 0.31 +/- 0.02. By contrast, in patients with OMI, there was a significant increase (p less than 0.001) in the relative echo intensity of the IVS (0.71 +/- 0.06). The relative echo intensity of the LVPW was less than normal, but the difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗