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Biomedical subjects

M Date

Publications and source records attributed to M Date.

At least 37 records · Page 2Linked to original sources
PubMed1993

Orientation of erythrocytes in a strong static magnetic field.

The frequency of exposure to strong magnetic fields has increased as the magnetic-resonance image-diagnostic technique (MRI) and passenger transport systems based on the principle of magnetic levitation have come into wider use. Accordingly, it has become necessary to more systematically assess their influence on the body and set strict guidelines on acceptable limits of magnetism exposure. Therefore, we have assessed the influence of an uniform static magnetic field (8 T in maximum) on normal erythrocytes. The erythrocytes were oriented with their disk plane parallel to the magnetic field direction. These erythrocytes were influenced even by 1 T and almost 100% of them were oriented when exposed to 4 T. Furthermore, the degree of orientation was not influenced by the state of hemoglobin (oxy: diamagnetic, deoxy and met: paramagnetic). The dependence of the measured degree of orientation on the intensity of the magnetic field was in good agreement with the theoretical equation for the magnetic orientation of diamagnetic substances. As a result of a numerical analysis based on the equation, the anisotropic diamagnetic susceptibility of erythrocytes was found to be delta chi = 8 x 10(-22) electromagnetic units/erythrocyte. It was almost in agreement with the calculated value delta chi = 6 x 10(-22) emu/erythrocyte estimated from the diamagnetism of the membrane constituents of erythrocyte.

Cell Polarity↗
PubMed1993

11q trisomy detected by fluorescence in situ hybridization.

A patient with psychomotor developmental delay, multiple minor anomalies, congenital heart disease and left inguinal hernia is reported. His karyotype was 45,X/46,X,+mar (3:37 cells), and the marker chromosome was identified as t(Y;11)(q12;q14?) using fluorescence in situ hybridization and fluorescent chromosome painting. He was diagnosed as mosaic for de novo 11q trisomy.

Abnormalities, Multiple↗
PubMed1993

Collagen production and maturation at the experimental ligament defect stimulated by pulsing electromagnetic fields in rabbits.

Eighty rabbits receiving the square resection (4 x 4 mm) of both patellar ligaments in full thickness at their center were divided into 4 groups, and each group (20 rabbits) were electromagnetically stimulated with different magnetic intensities, 0 (control group), 2, 10, or 50 gauss (G), for 6 hr daily. Pulse frequency and pulse width were 10 Hz and 25 microseconds, respectively. Five animals of each group were sacrificed weekly from 1st to 4th week after operation and the defect tissue was collected for biochemical and ultrastructural evaluations. Before sacrificing, the blood flow of the central portion of patellar defects were measured. Significant increases in blood flow at the defect were observed in 50 G group compared to those of other groups from 2 to 4 weeks after operation. The collagen content in PEMFs groups showed a significant increase compared to that of control group. Furthermore, those increases were higher according to the increase in magnetic intensity. Electronmicroscopically, massive developmental rough endoplasmic reticulum was seen in the fibroblasts at 2 weeks after operation in 50 G group compared to other groups, which suggests the more active collagen production in this group. These results suggest that PEMFs enhanced the blood flow and increased the fibroblasts at the defect. At the same time, PEMFs directly stimulated the collagen production from the fibroblasts, thus accelerate the healing process of the ligament.

Animals↗
PubMed1993

Ultrastructural localization of myeloperoxidase activity in acute monoblastic leukemia.

In five patients with acute monoblastic leukemia (AMoL), the ultrastructural localization of myeloperoxidase (MPO) activity was investigated by two methods, one generally used for the detection of MPO and the other for the detection of platelet peroxidase. The MPO-positive rate achieved was lower with the former method than with the later, indicating that MPO is degraded during the fixation of AMoL cells for electron microscopy. If the ultrastructural MPO positivity of leukemic cells varies when different detection methods are used, the possibility of monocytic leukemia should be considered.

Adult↗
PubMed1992

Effects of pulsing electromagnetic fields on the ligament healing in rabbits.

Effects of pulsing electromagnetic fields (PEMFs) on ligament healing were investigated using 80 rabbits. All animals received square resection (4 mm x 4 mm) of both patellar ligaments in full thickness at their center. They were divided into 4 groups of 20 rabbits each and stimulated with different electromagnetic intensity of 0 (control), 2, 10, and 50 gauss (G) for 6 hr daily. Pulse frequency and pulse width were 10 Hz and 25 microseconds, respectively. After PEMFs stimulations for 1, 2, 3 and 4 weeks, 5 animals of each group were euthanized and the regenerated tissue at the defective portion was investigated histologically and biomechanically. Histologically, the tissue stimulated by PEMFs showed an earlier increase in capillaries and fibroblasts and more matured, prominent longitudinal orientation of collagen fibers than those of control groups. Among the rabbits stimulated electromagnetically, those stimulated at 50 G revealed the earliest ligament healing. Tensile strength of regenerated ligament tissues of any PEMFs groups increased significantly at 1 and 2 weeks after operation, however, at 3 and 4 weeks after operation, there were no significant differences between groups. Among these values, those of 50 G group were the highest consistently during most of the experimental period. From the above results, PEMFs enhanced the earlier stage of ligament healings and 50 G gauss seemed to be the most effective among the 3 field intensities used. This promoting effect may potentiate the earlier recovery of the function after the ligament injury.

Animals↗
PubMed1992

[Clinical study of synchronous multiple primary cancer involving the lung].

Ten cases of synchronous multiple primary cancer involving the lung were experienced in our hospital during the period from January 1962 to May 1987. The incidence rate was 1.3% of all hospitalized cases of primary lung cancer. The counterpart organs were thyroid gland (4 cases), stomach (2 cases), colorectum (2 cases) and lung (2 cases). Three of four thyroid cancer cases were resected at the same time of pulmonary resection, whereas the stomach and colorectal cancer cases underwent two stage operation. Lung perfusion scintigraphy was very useful in determining the operative method for synchronous multiple primary lung cancer. The 5-year survival rate of all cases of synchronous multiple primary cancer involving the lung was 26.3%, with no hospital death. Surgical treatment is recommended for such cases when both cancers are expected to be resected completely.

Adult↗
PubMed1991

Influence of peripheral nerve stimulation on the responses in small hand muscles to transcranial magnetic cortex stimulation.

The influence of afferent median nerve stimulation on the responses of small hand muscles (CMAPs) to cortical stimulation (CortStim) was investigated by applying short stimulus trains to the median nerve at the wrist and slightly suprathreshold magnetic stimuli to the scalp. Train stimulus frequency (TSF), train stimulus intensity (TSI), and train onset (TO) in relation to the CortStim were varied. Amplitudes and latencies of CMAPs were compared with those obtained by CortStim alone. When applying short trains of 10 msec duration, of 300/sec-400/sec TSF, and of threshold or supramaximal intensity for motor fibers, both facilitatory and inhibitory effects on the responses to CortStim were achieved depending on the timing of the train onset. With a TO of 8-10 msec before CortStim, mean amplitudes of CMAPs were enhanced 3-10 times; mean amplitudes reached up to 20 times the baseline values when the TO was greater than 45 msec before CortStim. With a TO of 15-35 msec before CortStim, amplitudes were diminished below control values. No systematic changes in latency were noted with TO of 8-10 msec, but when the TO was 45-60 msec before CortStim the latencies of CMAPs were 1.5-3 msec shorter than baseline latencies. With afferent stimuli that were subthreshold for motor fibers facilitation only occurred when the TO was about 45 msec before CortStim. The differences were statistically significant (Wilcoxon-Mann-Whitney Test). This biphasic pattern of facilitation and inhibition probably reflects spinal and supraspinal reflex phenomena mediated by spindle receptor and various cutaneous afferents.

Action Potentials↗
PubMed1990

[Experimental studies on canine tracheal preservation].

Thirty-five adult mongrel dogs were anesthetized and a five-ring segment of cervical trachea was excised. The tracheal defect was restored by end-to-end anastomosis. The autografts were divided into 4 groups as follows; no preservation (control) group (n = 4), graft preserved in Collins solution (n = 11), graft preserved in phosphate buffered extracellular solution (Ep4) (n = 11), and graft preserved in physiological saline solution (n = 11) for 24 or 48 hours at 4 degrees C. After preservation, laparotomy was performed on the animals and the tracheal autograft was wrapped in the distal portion of the omentum. After 21 days all grafts were excised and examined by macroscopically, microscopically and scanning electron microscopically (SEM). The changes of the epithelia glands, and cilia were evaluated, with each item being rated on a point scale (1-3) according to the degree of regeneration and summed to form a total score. The total score of the Collins group was significantly higher than those of the Ep4 and saline groups. The present data suggest that tracheal autografts can be preserved for up to 48 hours in each of the solutions and that Collins solution is preferable for use in canine tracheal preservation.

Animals↗
PubMed1990

[A case report of widely recurrent carcinoid tumor of the thymus].

We performed wide resection of recurrent carcinoid tumor of thymus. A 62-year-old male patient admitted to our department because of swelling of anterior chest wall. He had received extirpation of thymic carcinoid tumor 5 years ago and he was pointed out large mass formation in anterior mediastinum before admission. Wide resection of tumor including pericardium, chest wall, left lung and left brachiocephalic vein was performed. Left brachiocephalic vein was reconstructed and pericardium was replaced with Gore-Tex patch. The carcinoid tumor of thymus sometimes invade to adjacent organs and is apt to recur long time after first operation.

Carcinoid Tumor↗
PubMed1989

[Three cases of endobronchial hamartoma].

We reported three cases of endobronchial hamartoma. There were some difficulties in diagnosis of the disease by bronchoscopic examination, because the tumors were covered with normal bronchial epithelium. But X ray film and CT film contributed to the diagnosis when calcification of intra-bronchial tumor was observed. Three different modes of operation were performed as extirpation of tumor by wedge resection of upper lobe bronchus, sleeve resection of left S6 segmental bronchus, and right middle lobectomy.

Adult↗
PubMed1989

[Application of omental pedicle to tracheal allotransplantation: an experimental study using adult mongrel dogs].

Methods and results of experimental tracheal allotransplantation using adult mongrel dogs are described in this paper. Omental pedicle flap was used to reconstruct the vascularity of ischemic tracheal allograft. Twenty out of 22 allografts were found to be viable with almost normal tracheal structure and no granulation or stricture. The allografts were proved to be well revascularized from the omental pedicle flap by injection of Indian ink from the right gastroepiploic artery.

Animals↗
PubMed1989

[A case of mediastinal cystic lymphangioma--case reports and review of the literature in Japan].

A 15-year-old woman was admitted to our hospital with complaints of left anterior chest pain and an abnormal shadow on her chest X-ray film. At the left thoracotomy, a large cyst (20.5 x 15 x 3 cm) was located in the left anterior mediastinum and contained translucent yellow fluid. Histological diagnosis was cystic lymphangioma. Mediastinal cystic lymphangioma is very rare among mediastinal tumors. Altogether 32 cases of mediastinal cystic lymphangioma including our case were collected from the Japanese literature and reviewed.

Adolescent↗