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Biomedical subjects

S Miyazaki

Publications and source records attributed to S Miyazaki.

At least 523 records · Page 29Linked to original sources
PubMed1991

Morphologic changes in detrusor muscles of patients with chronic obstruction of lower urinary tract. Electronmicroscopic and immunohistochemical findings.

The anterior bladder wall and actin- and myosin-like immunoreactivities within the detrusor muscles in patients with chronic obstruction of the lower urinary tract were examined by means of a MOP Videoplan image-processing system, electronmicroscopy, and light microscopic immunohistochemistry. The image-processing system demonstrated an excess of connective tissue elements between smooth muscle bundles in the anterior wall of the bladder similar to the results of previous studies dealing with the trabeculated posterior wall. Under electronmicroscopy, myofilaments were shown to be multidirectionally arranged in the smooth muscle cells in contrast to the regular arrangement in controls. Dense areas in the cytoplasm of the detrusor muscle also appeared to be abnormally distorted and/or elongated in the electronmicrographs. In support of these findings, actin- and myosin-like immunoreactivities in the muscle layer of the bladder were significantly less intense than in the controls. These results suggest that chronic obstruction of the lower urinary tract causes histopathologic alterations in both the intervening connective tissue and the detrusor muscle. This study raises the possibility that the aforementioned morphologic abnormalities are involved in the occurrence of uninhibited detrusor contraction and abnormal detrusor reflex in patients with lower urinary tract obstruction.

Actin Cytoskeleton↗
PubMed1991

Setleis bitemporal "forceps marks" syndrome and its pathogenesis: a case report.

Setleis bitemporal "forceps marks" syndrome is characterized by "forceps marks" and a peculiar facies. The syndrome has previously been reported mainly in the Puerto Rican population. We describe here a Japanese boy with the syndrome. In addition, the hypothesis is presented that the Setleis syndrome may result from an insufficient migration of neural crest cells into the frontonasal process and the first branchial arch.

Abnormalities, Multiple↗
PubMed1991

Late effects of childhood acute leukemia and its treatment.

Late effects of childhood acute leukemia and its treatment were studied in 776 patients (684 ALL, 73 ANLL, and 9 others) in Japan who had remained in remission for more than 1 year after their first complete remission. Delayed adverse sequelae involve a wide variety of organs and their functions. Short stature was present in 2.61%, obesity in 3.79%, abnormalities of growth hormone secretion in 1.5%, delayed secondary sex characteristics in 1.5% of males and 0.6% of females, motor disturbances in 1.17%, sensory disturbances in 0.91%, intellectual and learning disabilities in 2.48%, abnormal findings in routine neurologic examinations in 1.31%, EEG abnormalities in 4.30%, brain CT abnormalities in 5.09% and cardiac dysfunction in 1.07%. Various other disorders were seen in 20 patients. Many of these delayed adverse sequelae are caused by or related to central nervous system prophylaxis and systemic combination chemotherapy. The results suggest that it is needed to improve therapeutic methods through the stratification of patients by risk factors and detailed analysis of prognostic factors. Moreover it is important to render medical and psychosocial support to long-term survivors of childhood leukemia through interactions between the patient, parents and medical staff.

Adolescent↗
PubMed1991

Leukotriene B4 and Kawasaki disease.

The role of LTB4 in Kawasaki disease as a chemo-attractant and immunomodulator is reviewed through our own experience and reports by other investigators. In our experiment using 19 patients, we measured calcium ionophore-stimulated LTB4 synthesis in PMNs obtained in three different stages of the illness (acute, convalescent and recovered phases). LTB4 synthesis was significantly increased in the convalescent phase of the illness. Other investigators showed increased serum-LTB4 concentration in acute as well as convalescent phases, suggesting that LTB4 participated in the inflammatory process of Kawasaki disease as an inflammatory mediator and immunomodulator. However, no difference was found in LTB4 synthetic activity in PMNs in any phases of the illness between the patients with and without coronary lesions, which indicated that LTB4 was not a parameter of coronary aneurysm formation. Therapeutic use of high-dose gamma-globulin showed a tendency to decreased LTB4 synthesis in PMNs, although it is not conclusive.

Child↗
PubMed1991

Characterization and modification of brain activity with deep brain stimulation in patients in a persistent vegetative state: pain-related late positive component of cerebral evoked potential.

A series of eight patients in a persistent vegetative state (PVS) were subjected to chronic deep brain stimulation (DBS) for the purpose of promoting recovery from the PVS. The characteristics of the brain activity in these patients were evaluated from the late positive component of the cerebral evoked potential in response to painful stimuli (pain-related P250). While any neurological scoring system for the comatose state includes evaluations of motor reactions to painful stimuli, the pain-related P250 is unique in terms of its ability to assess the cortical responsiveness to painful stimuli directly and quantitatively without involving functions of the motor system. It was found that the pain-related P250 was more or less depressed in patients in a PVS. It was repeatedly demonstrated in four patients, however, that the pain-related P250 could be transiently increased by preceding stimulation of the mesencephalic reticular formation. Furthermore, a persistent increase in the pain-related P250 was produced in these four patients following chronic DBS of the mesencephalic reticular formation or nonspecific thalamic nuclei for more than 6 months, and this was correlated with the clinical improvements. These results imply that responsiveness at the cortical level to pain is depressed in the PVS. It also appears that some fraction of the depression may, however, be functionally produced and potentially reversible.

Brain↗
PubMed1991

External control of drug release and penetration: enhancement of the transdermal absorption of indomethacin by ultrasound irradiation.

The effect of ultrasound (1 MHz) on transdermal absorption of indomethacin from an ointment has been studied in rats. Ultrasound energy was supplied for 10 min at a range of intensities (0.25, 0.5 and 0.75 W cm-2), energy levels commonly used for therapeutic purposes. The pronounced effect of ultrasound on transdermal absorption of indomethacin was observed for all three intensities studied. The mean AUC value (33.22 micrograms h mL-1) after irradiation at 0.75 W cm-2 was 3.4 times the control value (9.70 micrograms h mL-1).

Administration, Cutaneous↗
PubMed1991

New mathematical definition and calculation of axial rotation of anatomical joints.

In the field of joint kinematics, clinical terms such as internal-external, or medical-lateral, rotations are commonly used to express the rotation of a body segment about its own long axis. However, these terms are not defined in a strict mathematical sense. In this paper, a new mathematical definition of axial rotation is proposed and methods to calculate it from the measured Euler angles are given. The definition and methods to calculate it from the measured Euler angles are given. The definition is based on the integration of the component of the angular velocity vector projected onto the long axis of the body segment. First, the absolute axial rotation of a body segment with respect to the stationary coordinate system is defined. This definition is then generalized to give the relative axial rotation of one body segment with respect to the other body segment where the two segments are moving in the three-dimensional space. The well-known Codman's paradox is cited as an example to make clear the difference between the definition so far proposed by other researchers and the new one.

Biomechanical Phenomena↗
PubMed1991

[Effect of macrolide antibiotics on human serum-bactericidal sensitivity of Pseudomonas aeruginosa S-6].

It is well known that long-term administration of erythromycin (EM) at a small dose is effective for persistent infections with Pseudomonas aeruginosa in diffuse panbronchiolitis or chronic bronchitis patients. Since EM is less active against P. aeruginosa in vitro, we have been interested in the mechanisms of clinical efficacy of EM in these patients. This study examines the effect of macrolide antibiotics on human serum-bactericidal sensitivity of P. aeruginosa S-6, clinically isolated from the patient with respiratory tract infection. A significant increase in serum-bactericidal sensitivity of P. aeruginosa S-6 was observed on agar containing EM of 10 micrograms/ml after incubation for 36-60 hours (p less than 0.05). The enhancement of serum sensitivity of P. aeruginosa S-6 was apparently observed even at a concentration of EM 1.5 micrograms/ml after the 48 hours incubation (p less than 0.01). Of other macrolide antibiotics used, clarithromycin (CAM) also increased the serum-bactericidal sensitivity of P. aeruginosa S-6 as well as EM, however no change in the sensitivity was found with kitasamycin, josamycin, rokitamycin and oleandomycin. The results suggest that the change of serum-bactericidal sensitivity of P. aeruginosa induced by EM or CAM may, in part, contribute to the clinical efficacy of these antibiotics against persistent pulmonary P. aeruginosa infections.

Anti-Bacterial Agents↗
PubMed1991

[Hepatosplenic candidiasis in acute non-lymphocytic leukemia].

Eleven patients with acute non-lymphocytic leukemia developed hepatosplenic candidiasis following the termination of chemotherapy. Five who did not receive amphoteicin B (AMPH) died of liver failure, whereas the other six who received AMPH and/or miconazole or fluconazole were cured. The features of hepatosplenic candidiasis included prolonged high fever not responsive to antibiotics and hepatomegaly with right-sided hypochondrial pain developing after severe neutropenia. Even if the neutropenia recovered, these symptoms did not subside. In addition, elevation of the serum alkaline phosphatase and total bilirubin levels were observed at onset. CT scan revealed multiple low-density areas of varying size that showed no contrast enhancement. Ultrasonography also demonstrated hypoechoic or hyperechoic lesions, and a so-called "target sign appearance" in the liver and spleen. The clinical diagnosis for hepatosplenic candidiasis is not so difficult because of the uniform symptoms, signs and laboratory abnormalities. The importance of the early administration of antifungal agents to obtain a cure is discussed in this article.

Adult↗
PubMed1991

[A novel approach to the detection of Neisseria gonorrhoeae employing DNA probe method].

The present study was undertaken to establish a novel detection method for Neisseria gonorrhoeae (N. gonorrhoeae). DNA probe obtained from Gen-probe Inc. was employed and clinically isolated strains (18 species, 81 strains) were applied to verify the quality and quantity of the method. The present data revealed that the method is specific to detect N. gonorrhoeae (30/30): neither gram positive nor negative oraganisms were detectable by the method (0/51). It has been shown, further more, that there exists a significant correlation between the number of the bacteria and the relative light units (r = 0.96). The threshold of cell numbers, on the other hand, was found to be 5 X 10(3) cfu/tube. The detection sensitivity for N. gonorrhoeae was not influenced by the presence of other bacteria, and not decreased by using heat-treated or drug-treated N. gonorrhoeae organisms. The present study also provides some experimental evidences that the method can also be applicable for the detection of bacteriolytic action of drugs.

Bacteriological Techniques↗
PubMed1991

In vitro antibacterial activity of ME1207, a new oral cephalosporin.

ME1207 is the prodrug of ME1206. Its in vitro antibacterial activity was compared with that of cefteram, cefpodoxime, cefixime, and cefaclor against various clinical isolates. ME1206 was more active than the other cephems tested against staphylococci, streptococci, Morganella morganii, Pseudomonas cepacia, and Flavobacterium meningosepticum and had the most potent activity against Haemophilus influenzae and Neiserria gonorrhoeae. The drug also showed a wide spectrum of activity against other gram-positive and gram-negative bacteria, except methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, Citrobacter freundii, Pseudomonas aeruginosa, Xanthomonas maltophilia, and Alcaligenes xylosoxydans.

Administration, Oral↗
PubMed1991

Heart rate reduction improves myocardial ischemia in swine: role of interventricular blood flow redistribution.

Regional myocardial blood flow (MBF) distribution and function upon slowing the heart rate (HR) during ischemia were studied in anesthetized swine, a species without coronary collaterals. Perfusion of the left anterior descending artery by a pump allowed controlled production of regional ischemia. Slowing tachycardia by electrical pacing (127 to 87 beats/min) caused marked improvement of regional dysfunction [% wall thickening (WTh) from 9 to 27%] and increased subendocardial MBF [from 0.31 to 0.55 ml.min-1.g-1 (P less than 0.001)] without change of subepicardial MBF. Total left ventricular (LV) MBF increased, whereas right ventricular (RV) MBF fell by 18% (P less than 0.02). The mechanism of MBF changes during slowed HR was assessed by surgically excluding the RV and comparing findings with previous experiments with RV intact when HR was slowed from 96 to 60 beats/min. A similar improvement of regional LV function occurred (8% vs. 30% WTh) with the RV excluded, but without a change in total flow to the LV bed, whereas subendocardial MBF increased and subepicardial MBF fell, indicating transmural redistribution only. These findings show that the RV vascular bed can contribute to LV perfusion in swine during ischemia, and they document the potential for "reverse RV steal" during slowed heart rate in this setting.

Animals↗
PubMed1991

Matrix vesicles in bone tumors. Ultrastructural analysis and their significance in neoplastic bone formation.

Bone tumors were categorized into alkaline phosphatase (ALPase)-positive (2 ossifying fibromas, 1 benign osteoblastoma and 16 osteosarcomas) and negative (2 chondromas, 2 chondrosarcomas, 3 non-ossifying fibromas, 2 malignant fibrous histiocytomas and 6 giant cell tumors of bone) groups. Production and distribution of matrix vesicles (MVs) in the tumor tissues were examined to clarify their role in neoplastic bone formation. Four distinct types of MV were isolated primarily in ALPase positive bone tumors: empty, amorphous, crystalline and ruptured MVs. They were formed by budding off from the cytoplasmic projections of the osteoblastic tumor cells. The significance of differences in the production rate of MVs between ALPase-positive and negative bone tumors was investigated in view of the predominantly high production of MVs in ALPase-positive bone tumors. Many more mature MVs (crystalline and ruptured) were observed in the osteoblastic lesions of osteosarcoma than in the fibroblastic and MFH-like lesions, suggesting an intimate relationship with maturation and differentiation of the osteoblastic tumor cells. The above findings indicate that production of MVs is one of the diagnostic parameters for osteoblast-derived bone tumors, as well as ALPase activity, and that vesicle-induced mineralization is a major mineralization mechanism in neoplastic bone formation.

Adolescent↗
PubMed1991

Inactive renin release from the human arm vascular wall during upper arm occlusion: relation to beta-adrenoceptors.

To investigate the extrarenal release of renin, plasma active renin (PAR) and plasma trypsin activatable or inactive renin (PIR) in blood taken simultaneously from bilateral median cubital veins were measured in seven normal men before and after occlusion of the right upper arm with a standard cuff inflated halfway between systolic and diastolic blood pressures for 15 min. After 15 min, both PAR (P less than 0.05) with PIR (P less than 0.01) increased significantly in occluded arms compared with 0 min. PIR rose significantly (P less than 0.01) in occluded arms compared with controls at 15 min, but PAR was unchanged. The same studies were repeated after pretreatment with oral doses of either 1 mg prazosin or 10 mg propranolol at 1600 h and 2400 h on the previous day and 1 hour before the experiment. After prazosin, both PAR (P less than 0.05) and PIR (P less than 0.01) in occluded arms increased significantly at 15 min compared with those at 0 min and PIR rose significantly (P less than 0.01) in occluded arms compared with controls at 15 min, as observed in the control studies. On the other hand, after propranolol, the significant increment of PAR in the occluded arms was abolished. Moreover, the significant difference of PIR between the occluded and the control arms at 15 min was also abolished. These results indicate that inactive renin may be present in the vascular wall of the arm and released into circulation by a stimulus such as arm occlusion by mechanisms related to beta-adrenoceptors.

Administration, Oral↗
PubMed1991

[Requirements of diagnostic criteria for aplastic anemia in children].

As a general rule, diagnostic criteria of aplastic anemia in children are the same as adult criteria. However, blood counts of normal children show wide age-related variation, therefore we must establish a system of adjustment for diagnosis of aplastic anemia in children. The data of children with aplastic anemia visiting our institutes from 1966 to 1990 were evaluated for this study. RBC below 350 x 10(4)/microliters, WBC below 4,000/microliters or neutrophils below 1,500/microliters, platelets below 8 x 10(4)/microliters, reticulocytes below 4 x 10(4)/microliters and lymphocytes over 60% were seemed to satisfy the diagnostic criteria of aplastic anemia proposed by the Study Group of hemopoietic Disorders sponsored by the Ministry of Health and Welfare of Japan. Fifteen children (4.6%) did not meet these criteria and as such were diagnosed as atypical aplastic anemia. Thirteen of them were in a pre-aplastic state and developed typical aplastic anemia within 6 months to 8 years after the initial diagnosis. Clinical findings of these patients showed the decrease in number of megakaryocytes and committed stem cells in bone marrow. Three of these patients developed acute non-lymphocytic leukemia, and 2 of them were diagnosed as Fanconi's anemias.

Adolescent↗
PubMed1991

[Medical therapy in patients with left main coronary artery stenosis].

To elucidate the long-term prognosis of medically-treated patients with left main coronary artery (LMCA) lesions, 119 consecutive patients with LMCA lesions undergoing coronary angiography were analyzed retrospectively. Among these, 3 patients died soon after angiography and were excluded from this study. Among the remaining 116 patients, 22 were treated medically (Group M) for the following reasons: profound left ventricular (LV) dysfunction (3 patients), effective pharmacological treatment (10), and patients' refusal of surgical therapy (9). Among 94 patients who underwent coronary artery bypass graft (CABG), 83 patients survived (Group S). During the follow-up period, cardiac events occurred in 5 patients in Group M; cardiac deaths in 3, non-fatal myocardial infarction (MI) in one and late application of CABG in one. Two-year cardiac event-free rate after diagnosis was 77%, which remained unchanged thereafter. The cumulative survival rate was 83%. The incidence of cardiac events in Group M was higher than that in Group S (p < 0.01). However, cardiac event rates were similar between these 2 groups for patients with good collateral circulations to the left coronary arteries, no preceding MI and LV end-diastolic pressure less than 15 mmHg. We concluded that the Japanese patients with severe LMCA lesions who respond favorably to pharmacological intervention have unexpectedly good prognoses, however, obstructed collateral circulation to the left coronary system, the presence of preceding MI and high LV end-diastolic pressure were all high-risk factors for medically-treated patients.

Adult↗