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Biomedical subjects

T Misawa

Publications and source records attributed to T Misawa.

At least 19 recordsLinked to original sources
PubMed2001

Experimental observation of vertically polarized transverse dust-lattice wave propagating in a one-dimensional strongly coupled dust chain.

Externally driven, vertically polarized transverse dust-lattice waves were observed in a one-dimensional strongly coupled dust chain levitated in the plasma-sheath boundary of a dc argon plasma at low gas pressure around 5 mtorr. Real and imaginary parts of the complex wave number were measured in the experiments. The experimental result clearly shows that the observed transverse dust-lattice wave propagates as a backward wave, which is in good agreement with the theoretical prediction.

Journal Article↗
PubMed2001

Evaluation of thoracic myelopathy by transcranial magnetic stimulation.

It is sometimes difficult to determine the appropriate surgical site in patients with thoracic myelopathy with diffuse or multisegmental lesions. To solve this problem, a magnetic stimulation study was carried out. Seven patients with myelopathy and 10 healthy control subjects were examined. Transcranial magnetic stimulation was applied and the motor evoked potentials (MEPs) of the intercostal muscles were recorded. The MEP latencies for the two groups were then compared. In patients with thoracic myelopathy, the MEP latencies caudal to the lesion were more extended than those of the control subjects. This method could identify the levels at which myelopathy originates in patients with a radiologically visible lesion. This method has the potential to be used for deciding the surgical site at the level responsible for myelopathy in cases with multiple or diffused compression.

Adult↗
PubMed2001

Biventricular hypertrophic cardiomyopathy with right ventricular outflow tract obstruction associated with Noonan syndrome in an adult.

This report describes an adult patient with Noonan syndrome accompanied by biventricular hypertrophic cardiomyopathy causing isolated right ventricular outflow tract obstruction. Biventricular hypertrophic cardiomyopathy causing right- and/or left-side outflow tract obstruction, as well as valvular pulmonary stenosis, is relatively common in infants with Noonan syndrome. However, this condition without a dysplastic pulmonary valve, or indeed any polyvalvular dysplasia, is rare in adults with Noonan syndrome. Treatment with a beta-adrenergic receptor blocking agent improved the patient's symptoms. Because neither the etiologic and prognostic relationship nor the genetic linkage between hypertrophic cardiomyopathy associated with Noonan syndrome and non-syndromic hypertrophic cardiomyopathy is clearly defined, clinicopathological findings and further follow-up may provide important evidence for the pathogenesis of hypertrophic cardiomyopathy.

Adult↗
PubMed2000

Recurrent Wegener's granulomatosis with subglottic granulation.

While following the course of patients with Wegener's granulomatosis (WG) in which it had been possible to achieve a remission, we encountered a patient in whom we observed granuloma formation in the subglottis. A tracheotomy was performed because of the risk of respiratory distress, and after that there was a recrudescence of the patient's WG. During the course of the above, the patient remained cANCA (anti-neutrophil cytoplasmis antibody with cytoplasmic pattern)-negative. When these facts were considered, it appeared that when the lesions are localized and progressing gradually, cANCA positivity does not develop. While cANCA test has gradually become a powerful tool for the diagnosis of WG, a comprehensive physical examination to identify localized lesions, together with biopsy and histopathological examination, should allow the diagnosis of WG.

Adult↗
PubMed1999

Peroneal nerve palsy caused by intraneural ganglion.

A case of peroneal nerve palsy caused by an intraneural ganglion is presented. The cystic mass was located posterolateral to the lateral femoral condyle and extended along the common peroneal nerve distal to the origin of the peroneus longus muscle. The nerve was compressed in the narrow fibro-osseous tunnel against the fibula neck and the tight origin of the peroneus longus muscle. The nerve was decompressed by complete tumor excision and transection of the origin of the peroneus longus muscle. Full recovery of nerve function was obtained in 6 months.

Cysts↗
PubMed1999

Ultrasonographic assessment of the risk of injury to branches of the middle hepatic vein during laparoscopic cholecystectomy.

BACKGROUND: Although hemorrhage from the gallbladder bed during laparoscopic cholecystectomy is one of main reasons for conversion to open cholecystectomy, the cause of this life-threatening complication is unclear. PATIENTS AND METHODS: Color Doppler ultrasound was used to examine the cause of venous hemorrhage from the gallbladder bed during laparoscopic cholecystectomy in 4 patients postoperatively and to examine the anatomic relationship between the gallbladder bed and branches of the middle hepatic vein in 50 healthy volunteers. RESULTS: Injury to a large branch of the middle hepatic vein adjacent to the gallbladder bed was diagnosed in all 4 patients. One patient required conversion to open cholecystectomy while the bleeding in 2 patients was immediately controlled by direct pressure with the gallbladder. The branch of the middle hepatic vein was completely adherent to the gallbladder bed in 5 of the 50 volunteers, and in 1 the diameter of the branch was as large as 3.5 mm. In 3 volunteers branches 3.0 to 3.8 mm in diameter traversed as close as 1.0 mm from the gallbladder bed. CONCLUSIONS: Patients with large branches of the middle hepatic vein close to the gallbladder bed are at risk of hemorrhage during laparoscopic cholecystectomy and should be identified preoperatively with ultrasound.

Adult↗
PubMed1999

Intrauterine growth retardation as a cause of perinatal mortality in Japanese black beef calves.

Perinatal death is one of the major causes of calf mortality in Japanese Black beef herds. A series of experiments were carried out to determine causes of perinatal calf mortality in a region of northern Japan. An aetiological survey revealed that the incidence of perinatal mortality in 6475 calves was 4.5% and the majority of neonatal deaths were caused by weak calf syndrome. The weak calves delivered after a normal gestation period had a significantly lower body weight at birth than normal calves (P < 0.01), indicating growth retardation in the uterus during pregnancy. Haematological and histopathological examinations showed that the weak calves had anaemia characterized by a significant decrease of blood cell values and bone marrow hypofunction. The anaemia due to bone marrow hypofunction presumably caused intrauterine growth retardation of the foetus. Dams delivering the weak calves showed significantly lower serum concentrations of estrone sulphate during late pregnancy than those with normal calves (P < 0.01), indicating foeto-placental dysfunction as a possible cause of growth retardation. Effects of sires as well as the maternal family on the incidence of neonatal death and on the rate of weak calves in dead neonates were found in the survey. Intrauterine growth retardation associated with anaemia may be the most important cause of weak calf syndrome in Japanese Black beef calves. The bull and maternal family may also have an influence on the incidence of neonatal death.

Anemia↗
PubMed1998

Abdominal incision tumor implantation following pneumoperitoneum laparoscopic procedure vs. standard open incision in a syngeneic rat model.

INTRODUCTION: A recent hamster model study suggests that the abdominal wall wound implantation rate increases following laparoscopic colon cancer surgery compared with the traditional open technique. However, results of that study were confounded by several factors, including a midline incision in the laparoscopy group, an unclear definition of wound implantation, significant age variations in study subjects, and cell line use with low viability. The aim of this study was to compare the abdominal incision implantation rates following a pneumoperitoneum-laparoscopic-type procedure with a standard open incision using a syngeneic host/colon cancer rat model. METHODS: Viable DHD/K12 rat colon carcinoma cells (2 x 10(5) cells/rat) were injected intraperitoneally via 18G angiocath into anesthetized, immunocompetent BD-IX rats (syngeneic host rats). Rats were then randomly divided into open incision and laparoscopy groups. At three weeks post-operatively, tumor growth at the injection, incision, and port sites was measured. RESULTS: Following standard midline incision, 50 percent of rats (26/50 rats) developed wound implantations, whereas only 25 percent of rats (14/57 rats) developed at least one trocar site wound implantation after laparoscopy with pneumoperitoneum. Fourteen percent of trocar sites (16/114 port sites) developed wound implantations. No tumor growth was noted on the peritoneal surfaces other than in the incisional sites. CONCLUSION: Laparoscopic-type procedure with pneumoperitoneum did not increase wound implantation in a syngeneic host/colon carcinoma rat model compared with the standard open incision technique.

Abdominal Muscles↗
PubMed1998

Mitral valve prolapse and autonomic function in panic disorder.

We investigated the significance of mitral valve prolapse (MVP) and autonomic function in 121 patients diagnosed with panic disorder (PD). The incidence of MVP was higher in these patients (32.2%) than in the healthy controls (16.7%), but the difference was not significant. In the group with PD accompanied by depression, the MVP rate was 58.1%, significantly higher than the value of 25.7% observed in the PD patients without depression. The severity of MVP was mild; nearly all of the cases were silent, without cardiac murmur, and there was no problem with the left ventricular function. The coefficient of variation for R-R intervals on electrocardiograms (CV R-R) was smaller in patients with PD than in healthy controls. The CV R-R of PD patients was significantly lower in the group with MVP than in the group without MVP, suggesting a strong association with the parasympathetic nervous system. Since the CV R-R tended to decrease in the presence of depression, involvement of the parasympathetic nervous system was inferred.

Adolescent↗
PubMed1998

Echocardiographic evaluation of cardiac valvular abnormalities in adults with Down's syndrome.

It is well known that congenital heart abnormalities are common in children with Down's syndrome. However there are few studies on cardiac abnormalities in adults with Down's syndrome. Therefore, we estimated cardiac abnormalities by means of echocardiography in 30 institutionalized Japanese adults with Down's syndrome, but without cardiac symptoms. Two-dimensional echocardiography showed an incidence of 26.7% in mitral valve prolapse and 20% increase of echo brightness in the mitral valve. Doppler echocardiography revealed an incidence of 16.7% in mitral valve regurgitation, and 13.3% in aortic valve regurgitation. Thus, even adults with Down's syndrome who are apparently free of cardiac symptoms may be at risk for valvular disease.

Adult↗
PubMed1998

First sporadic cases of non-pneumonic legionellosis, Pontiac fever in Japan.

Pontiac fever has rarely been found in sporadic cases. Here, we report the first sporadic cases of non-pneumonic legionellosis, Pontiac fever in Japan. Case 1. A 53-year-old man with spinocerebellar degeneration was presented to our hospital. He had an acute onset of high fever and consciousness disturbance. A chest X-ray film on admission was normal, but transient bilateral pleural effusions were revealed on hospital day 14. Case 2. A 77-year-old woman with gastric ulcer was presented to our hospital. She had an acute onset of high fever. A chest X-ray film on admission was normal, but transient bilateral pleural effusions were revealed on hospital day 7. High fever, resistant to beta-lactam antibiotics, continued in both cases. Both had serologic confirmation of legionellosis by indirect fluorescent antibody assay for Legionella pneumophila without seroconversion for Mycoplasma pneumoniae, and Chlamydia pneumoniae, and had a good prognosis. Both were thought to be sporadic community-acquired cases rather than epidemics.

Acute Disease↗
PubMed1997

Aminoglycoside-induced viability in cultured PtK1 proximal tubular cell lines.

The cell viability after aminoglycoside administration was evaluated by the determination of adenosine triphosphate (ATP) level and trypan blue exclusion of cultured PtK1 tubular cells. The assay in tubular cells was performed using luciferin-luciferase determined by a chemiluminator. The data are expressed as relative light units per milligram tissue protein. The standard curve of ATP showed a linearity from 0.5 to 2.5 mg/ml ATP as determined by the chemiluminator. The incubation time was steady for ATP production during 90 min after addition of ligand. The optimal incubation time was 60 min. The ATP production in PtK1 cells showed linearity within 10(3) to 5 x 10(6) cells in 200 microliters buffer. Although the magnitude of ATP production in Ptk1 cells was correlated with the cell viability as defined by trypan blue exclusion, the reproducibility of the former was better than that of the latter. The cell viability after application of aminoglycoside showed a decrement in a dose-dependent fashion. Our ATP assay is an excellent tool for determining the cell viability of renal proximal tubules in cases with tubular damage after administration of aminoglycoside antibiotics.

Adenosine Triphosphate↗
PubMed1997

How to decrease false-positive cases of ovarian cancer screening by transvaginal sonography.

Screening for ovarian cancer is an important step in improving ovarian cancer mortality. This is a report of screening for ovarian cancer using transvaginal sonography (TVS) on 2,095 asymptomatic women during the past four years. Ovarian tumors over 30 mm in diameter were detected in 87 women (4.2%). Fourteen tumors were morphologically classified as complex type and 73 as cystic type. Only 12 tumors were palpable on bimanual vaginal examination. Seven women with complex type tumors underwent laparotomy and their pathological diagnoses revealed 3 dermoid cysts, 3 endometrioid cysts and 1 ovarian cancer. Two women with cystic type tumors underwent laparotomy and their pathological diagnoses revealed 1 paraovarian cyst and 1 endometrioid cyst. Many ovarian tumors were detected at prolonged cycle of menstruation and 69% of them disappeared in repeated TVS. Sixty percent of ovarian cystic tumors under 50 mm in diameter also disappeared in repeated TVS. Close attention to menstrual cycle and morphologic findings is needed to decrease false-positive cases in TVS screening for ovarian cancer.

Adult↗
PubMed1996

Significance of serum lipase in patients undergoing hemodialysis.

Serum levels of lipase (Lp) during the end of the dialysis showed a significant increase after the administration of heparin in hemodialysis patients. However, serum Lp levels were not increased after the administration of the anti-coagulant nafamostat mesylate in hemodialysis patients. Serum levels of Lp were significantly correlated with serum levels of lipoprotein lipase (LPL), hepatic triglyceride lipase (H-TGL) and nonesterified fatty acid (NEFA) 20 min after the administration of heparin during maintenance hemodialysis. Lp activity did not appear with the NEFA ligand for determining the NEFA activity. Inhibitors of LPL and H-TGL reduced the measured Lp activity in vitro. The main mechanism of elevated measured serum Lp activity in hemodialysis patients was determined to be cross-reactivity with LPL or H-TGL. Furthermore, measurement of Lp may be a method for determining optimal coagulation time in patients with hemodialysis.

Adult↗
PubMed1996

Hyper-adrenocorticotropinemia in a patient with Addison's disease after treatment with corticosteroids.

A 40-year-old man with Addison's disease due to adrenal tuberculosis retained high levels of adrenocorticotropic hormone (ACTH) after conventional hydrocortisone replacement. Plasma ACTH levels were completely suppressed by usual replacement with hydrocortisone (20 mg at 8:00 and 10 mg at 21:00) but rebounded to abnormally high levels the following morning. Administration of 2 mg or 8 mg of dexamethasone suppressed ACTH and cortisol. Magnetic resonance imaging of the brain showed a low-intensity lesion of the pituitary gland. Pituitary hyperplasia or microadenoma with preserved regulation of ACTH was considered to be the cause of the high plasma ACTH levels. The combination of hydrocortisone and dexamethasone reduced plasma ACTH levels.

Addison Disease↗
PubMed1995

Natural killing activity is associated with progression of gastric cancer.

Previously, we proposed a new analysis of natural killing activity, in which an individual effector/target cell ratio was employed for comparison according to the peripheral number of effector cells. In 51 patients with gastric cancer, the activity was studied using that modified analysis. Natural killing activity was activated in patients with early cancer, where tumor-cell invasion was restricted to the mucosa or the submucosa, even though in well-differentiated adenocarcinoma with invasion of the mucosa alone, the activity remained at the level of controls. In contrast, the activity in advanced cancer, where tumor cells infiltrated beyond the submucosa, came to be inactivated as the cancer progressed. These facts suggest that natural killing activity in patients with gastric cancer is closely associated with tumor invasion and that reactive activation of the activity against tumor is induced, at least, in some patients with early stage.

Adenocarcinoma↗