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Biomedical subjects

H Suda

Publications and source records attributed to H Suda.

At least 127 records · Page 7Linked to original sources
PubMed1996

Age-related changes in the immunoreactivity of the monocyte/macrophage system in rat molar pulp.

Defence reactions of the dental pulp potentially involve a variety of immunocompetent cells, particularly class II major histocompatibility complex (MHC)-expressing cells and macrophages. In order to examine how the immunodefence potential of the pulp changes as a function of age, phenotypic distribution of pulpal cells expressing immunoreactivity to monoclonal antibody ED1 (reactive with nearly all macrophages and dendritic cells) was examined immunohistochemically in the lower first molars of developing (new-born to 10-week-old), adult (14-24-week-old) and aged (1-1.5-yr-old) Wistar rats. During tooth development, increasing numbers of ED1+ cells in the pulp also expressed immunoreactivity to ED2 (reactive with a differentiation-related antigen present on resident macrophages). ED1+ and ED2+ cells were distributed throughout the pulp before the tooth formation was completed. OX6+ (class II MHC-expressing) cells started to increase in number shortly after the eruption of the tooth and the increase continued even after the tooth formation had been completed. In aged rats, the density of the pulpal ED1+ cells was maintained at a relatively high level, whereas a significant decrease in the density of OX6+ cells was observed. These results indicate that the density and composition of pulpal cells expressing macrophage-associated antigens vary with increasing age, which most probably is related to changes in the immunological defence potential of the pulp against infection.

Aging↗
PubMed1996

Surgical treatment for acute aortic arch dissection.

Between March 1983 and December 1993, 24 consecutive patients with acute aortic dissection resulting from a tear located in the aortic arch or at the base of the innominate artery underwent surgical treatment. Before 1988, 11 patients (group 1) underwent either isolated ascending aorta replacement (eight cases) or composite graft replacement (three) by the conventional method. In this group, the hospital mortality rate was 36.4%; two of seven surviving patients required reoperation for aortic arch. After 1989, 13 patients (group 2) underwent either hemiarch replacement (five cases), total arch replacement (three), extended ascending aortic replacement or composite graft replacement with hemiarch replacement (one) under a brief period of circulatory arrest (mean 33.3 min) at a mean(range) rectal temperature of 20.8(18-23) degrees C by open distal anastomosis. The operative mortality rate in group 2 was 15.4%. Ten of 13 surviving patients are free from reoperation (mean follow-up 40 months). In most patients with acute type A dissection in which the tear is located at the proximal aortic arch or at the base of the innominate artery, the use of an open technique during a brief period of hypothermic circulatory arrest is advocated to: (1) perform a more secure distal anastomosis; (2) provide a more accurate assessment and resection of intimal disruption; and (3) avoid further aortic injury from the cross-clamp.

Acute Disease↗
PubMed1996

A new ultrasonic canal preparation system with electronic monitoring of file tip position.

A new ultrasonic root canal preparation system has been developed that electronically monitors the location of the file tip during all instrumentation procedures. The Root ZX has been adapted for this purpose, and its filter circuit effectively cuts out the large spike noise of the ultrasonic unit. During enlargement of the canal, the ultrasonic vibration of the file can be stopped at any desired position on the meter. Extracted human tooth models with electronically measurable canals were used to test the device. Pre- and postoperative shapes of the root canals were evaluated using contact microradiography. The autostop mechanism worked correctly. Using a weak power and fine files, straightening, ledge formation, and file breakage were minimal. It seems that this system minimized the danger of overinstrumentation and could be safely applied in clinical practice.

Dental Instruments↗
PubMed1996

Kinetics of macrophages and lymphoid cells during the development of experimentally induced periapical lesions in rat molars: a quantitative immunohistochemical study.

Quantitative phenotypical analysis for macrophages and lymphoid cells was made on periapical lesions induced by making unsealed pulp exposures in rat molars. Exudative macrophages of diverse morphology were the most dominating immunocompetent cells during all experimental periods. They exhibited almost complete distribution through the periapical lesions by the onset of active lesion expansion, and their kinetics and morphology were considerably similar to Ia+ non-lymphoid cells. Lymphoid cells started to show a notable increase shortly before the onset of active lesion expansion. CD4+ lymphocytes dominated at first, whereas CD8+ lymphocytes and plasma cells were dominant when the lesion size was stabilized. These findings suggest that macrophages of heterogenous populations play essential roles in the lesion pathogenesis by acting, depending on their functional heterogeneity, as effector cells or as antigen-presenting cells that stimulate CD4+ lymphocytes to induce an immune response. Interactions between plasma cells and CD8+ lymphocytes may be related to lesion chronicity.

Animals↗
PubMed1996

Pulpal blood flow assessed by laser Doppler flowmetry in a tooth with a horizontal root fracture.

Horizontal root fractures of both maxillary central incisors were diagnosed radiographically; neither responded to electric pulp testing nor to cold testing. The pulp of the right incisor was necrotic, whereas the pulpal status of the left incisor was uncertain. Pulpal blood flow of the teeth was measured with laser Doppler flowmetry. The blood flow of the left central incisor was 4.0. Eight months after the injury, a local anesthetic with a vasoconstrictor was administered to confirm pulp vitality. The blood flow of the tooth was decreased to 51% of the preanesthesia value after the local anesthesia. At 19 months after the injury, it responded to both the electric pulp test and cold test. Laser Doppler flowmetry is a noninvasive method of evaluating the blood flow status in human teeth, and it may provide a clinically reliable method of assessing pulpal vitality.

Adolescent↗
PubMed1996

Application of a new perchloric acid treatment method to measure endotoxin in both amniotic fluid and cord blood by an endotoxin-specific chromogenic Limulus test in intra-amniotic infection.

Endotoxin in both amniotic fluid and cord blood was measured to detect intra-amniotic fetal infection. Both amniotic fluid and cord blood plasma were pretreated by a perchloric acid treatment, and the endotoxin level was measured by Endospecy test. Cut off values for endotoxin in amniotic fluid and cord blood were 8.5 pg/mL and 7.6 pg/mL, respectively. Escherichia coli intra-amniotic infection caused respiratory distress syndrome (RDS)-mimicking pneumonia. Abnormally high values of endotoxin in both amniotic fluid and cord blood were detected. Intra-amniotic infection caused by Gram-positive bacteria (group B streptococci, Enterococcus fecalis) was shown to be endotoxin negative in both amniotic fluid and cord blood. In cases of negative amniotic fluid culture, measurement of the value of endotoxin in the amniotic fluid is useful in identifying intra-amniotic fetal infection.

Amniotic Fluid↗
PubMed1996

Correction of background noise in direct digital dental radiography.

OBJECTIVES: To clarify the source of noise in direct digital intra-oral radiography with RVG-S (Trophy Radiologie, Vincennes, France) and to use these to develop a method for correction of background noise. METHODS: Sensor temperature, image acquisition time and X-ray dose were independently analysed with the IPLab Spectrum (Signal Analytics, Vienna, VA) software. RESULTS: The decrease in pixel value due to the dark current was linearly related to the image acquisition time. Although a variation in sensitivity was observed when the sensor was exposed to X-rays, the mean pixel value of the entire image was linearly related to the exposure time. The image showing only the signal due to X-ray dose was derived from the original RVG-S image by correcting for the dark current and the pixel-by-pixel sensitivity variation of the CCD sensor. CONCLUSION: The image formed only by X-ray dose distribution can be derived by correcting for the background noise.

Algorithms↗
PubMed1996

[A case report of mitral valve plasty for traumatic mitral regurgitation].

A 64-year-old man was admitted to our hospital with a chief complaint of general fatigue on June 24, 1993. He had no history of rheumatic fever but bruised in the chest in September 1990. After that, his systolic murmur was noticed at the apex and echocardiogram showed the posterior chordal rupture of mitral valve. Mitral valve plasty was performed successfully.

Chordae Tendineae↗
PubMed1996

[Experience with 2 cases of traumatic diaphragmatic hernia occurred at the same time].

Two cases of traumatic diaphragmatic hernia (TDH) which occurred at the same traffic accident, are reported. The first case, a plain chest X-P was diagnostic of TDH. With thoracotomy and additional laparotomy, lacerated diaphragm was repaired. The second case, continual observation on plain chest X-P was useful to suspect TDH, and thoracoscopy was diagnostic. With thoracotomy diaphragm was repaired. Two patients recovered well. It has not been reported that two cases of TDH occurred at same trauma. For diagnosis of TDH, chest X-P is useful for suspicion, and thoracoscopy is useful for correct diagnosis. Surgical approach should be decided in consideration of phase, location, and complicated injuries.

Accidents, Traffic↗
PubMed1996

[Surgery for acute type A aortic dissection associated with Marfan syndrome].

Recently, extended operation has been recommended for aortic dissection associated with Marfan syndrome. However, the operation for acute type A aortic dissection associated with Marfan syndrome is controversial. Between May 1985 and July 1994, 5 patients associated with acute type A aortic dissection and Marfan syndrome underwent surgical repair. CT examination on all patients, the survivors of the initial operation, revealed a gradually enlarged residual pseudolumen. 2 patients who underwent aortic root reconstruction and ascending aortic replacement for the initial operation eventually had to undergo aortic arch repair. From the results of this study and the improvements of intraoperative cerebral protection, we recommend aortic arch repair with aortic root reconstruction and ascending aortic replacement on initial emergency operation for acute type A aortic dissection associated with Marfan syndrome.

Acute Disease↗
PubMed1996

[An aortic valve-sparing operation (David's operation) for a patient with annulo-aortic ectasia (AAE) and aortic regurgitation (AR)--evaluation by intraoperative endoscopy].

Now, the standard operation for a case with AAE and AR is the composite graft replacement. In this case, an aortic valve sparing aortic root reconstruction, the so-called David's operation, and the intraoperative endoscopic study were performed. In the case of 68-year-old male with AAE and AR, the aortic valve was reimplanted in a tubular Dacron graft and coronary arteries were reconstructed with the Carrel patch technique. After the completion of the aortic root reconstruction, intraoperative endoscopic study revealed the disappearance of AR. Postoperative aortography revealed trivial AR and at present, seven months postoperatively, this patient have been uneventful. In this paper, we discuss the merits and demerits of the David's operation and the effectiveness of intraoperative endoscopic study for the aortic valve sparing operation.

Aged↗
PubMed1996

[Re-operation for Budd-Chiari syndrome].

A 42-year-old man, who underwent a radical operation for Budd-Chiari syndrome under femoro-femoral bypass in our hospital 5 years ago, was re-admitted for evaluation of progressive liver dysfunction and dilatation of superficial veins of scrotum and lower extremities. Cavography revealed complete obstruction at the portion of previous patch dilatation. We performed re-do operation by the same method except we chose this time the heparin-coated circulatory system including centrifugal pump and ringed ePTFE graft as a material of patch dilatation. Cavography after the re-do operation revealed widely patent IVC-RA junction and he has been doing well.

Adult↗
PubMed1996

[Chest wall Castleman's disease with massive pleural effusion].

A 38-year-old woman was admitted to our hospital due to dyspnea. A chest X-ray film showed a right-sided chest wall tumor and a massive pleural effusion. A sharply defined round tumor, 5 cm in diameter, was seen on a chest CT scan; this tumor was strongly stained by contrast medium. Angiography showed a feeding artery and strong tumor staining. Gallium scintigraphy showed no accumulation. The tumor was resected, after which the retention of pleural fluid stopped. The pathological diagnosis was hyaline vascular type Castleman's disease. In this case, hyaline vascular type Castleman's disease manifested on the chest wall as a vessel-rich tumor; can cause retention of pleural fluid without the syndrome of polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes.

Adult↗
PubMed1996

Comparative hemolysis study of clinically available centrifugal pumps.

Centrifugal pumps have become important devices for cardiopulmonary bypass and circulatory assistance. Five types of centrifugal pumps are clinically available in Japan. To evaluate the blood trauma caused by centrifugal pumps, a comparative hemolysis study was performed under identical conditions. In vitro hemolysis test circuits were constructed to operate the BioMedicus BP-80 (Medtronic, BioMedicus), Sarns Delphin (Sarns/3M Healthcare), Isoflow (St. Jude Medical [SJM]), HPM-15 (Nikkiso), and Capiox CX-SP45 (Terumo). The hemolysis test loop consisted of two 1.5 m lengths of polyvinyl chloride tubing with a 3/8-inch internal diameter, a reservoir with a sampling port, and a pump head. All pumps were set to flow at 6 L/min against the total pressure head of 120 mm Hg. Experiments were conducted simultaneously for 6 h at room temperature (21 degrees C) with fresh bovine blood. Blood samples for plasma-free hemoglobin testing were taken, and the change in temperature at the pump outlet port was measured during the experiment. The mean pump rotational speeds were 1,570, 1,374, 1,438, 1,944, and 1,296 rpm, and the normalized indexes of hemolysis were 0.00070, 0.00745, 0.00096, 0.00066, 0.00090 g/100 L for the BP-80, Sarns, SJM, Nikkiso, and Terumo pumps, respectively. The change in temperature at the pump outlet port was the least for the Nikkiso pump (1.8 degrees C) and the most with the SJM pump (3.8 degrees C). This study showed that there is no relationship between the pump rotational speed (rpm) and the normalized index of hemolysis in 5 types of centrifugal pumps. The pump design and number of impellers could be more notable factors in blood damage.

Blood Flow Velocity↗
PubMed1996

[Surgical results of elderly patients with valvular heart disease in acute surgical stage and late follow-up].

Surgical and late follow-up results were compared between 40 elderly patients over 70-years-old (group I) and 43 patients aged from 65 to 69-years-old (group II) with acquired valvular heart disease. There was one hospital death in group I, and two hospital deaths in group II. There was no difference between group I and group II in the rate of hospital mortality of the occurrence of the surgical complications. Postoperative respiratory failure did not occur even in the elderly patients with preoperatively impaired vital capacity (%VC below 60%). Postoperative cardiac function after aortic valve replacement for aortic stenosis in elderly patients more significantly improved in comparison with preoperative function. Survival rate was 62% in group I and 78% in group II from actual survival curve at 9 year after surgery by Kaplan-Meier method. Late survival rate and cardiac event free rate were not significantly different between group I and II. Surgical results in elderly patients with valvular heart disease were satisfactory.

Age of Onset↗
PubMed1996

[A case of mediastinal chordoma with Horner's syndrome].

Mediastinal chordoma is a very rare disease. A 32-year-old man was admitted for chest abnormal shadow on the left upper mediastinum. He had left Horner's syndrome on admission. T2 weighted MR image showed heterogeneous tumor shadow. Angiographically, the tumor had feeding arteries. Gallium scintigraphy indicated no abnormal accumulation. Operation was performed and the resected tumor was found to be a chordoma pathologically. He lives well without recurrence and metastasis for 2 years.

Adult↗