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Biomedical subjects

S Murayama

Publications and source records attributed to S Murayama.

At least 163 records · Page 9Linked to original sources
PubMed1992

[Effects of the combination of new quinolones and a nonsteroidal anti-inflammatory drug, fenbufen, on the EEG of rabbits].

A combination of fenbufen, a non-steroidal anti-inflammatory drug and the new quinolone produces a central stimulating action. To confirm the action, we used 6 kinds of new quinolones: enoxacin, norfloxacin, ofloxacin, ciprofloxacin, lomefloxacin and tosufloxacin in this experiment. The convulsive effects of these drugs were tested on the EEG recorded from the neocortex and subcortical regions of the rabbits. Animals treated with fenbufen (50-200 mg/kg, p.o.) tended to have a high amplitude slow wave in their EEG. Rabbits treated with the new quinolones at the dose of 100 mg/kg, p.o., with the exception of tosufloxacin, also tended to show a high amplitude slow wave in their EEG. Each new quinolone given 30 min after fenbufen (50 mg/kg, p.o.) elicited characteristic spikes on the EEG. Then, high-frequency-spikes and epileptiform seizure waves appeared for a long experimental period with this combination. The combination of fenbufen and tosufloxacin (100-400 mg/kg, p.o.) caused no changes in EEG and behavior. The spike and epileptiform wave could be suppressed only temporarily with diazepam (1-4 mg/kg, i.v.). These results suggest that combined use of fenbufen and one of the new quinolones, except for tosufloxacin, produces the seizure. Not only GABA but also several other mechanisms in the central nervous system may be involved in the convulsion.

Administration, Oral↗
PubMed1992

Effects of naloxone and levallorphan on the spinal cord reflex potentials under the spinal ischemic condition in cats.

The spinal reflex potentials elicited by electrical stimulation of the tibial nerve were recorded from the lumbo-sacral ventral root in spinal cats. When the thoracic aorta and the bilateral internal mammary arteries were occluded for 10 min, the potentials were completely depressed. Reappearance of these potentials could be observed at about 10 min after removal of the occlusion and they gradually recovered. Intravenous injection of naloxone (1 or 10 mg/kg) or levallorphan (0.1 mg/kg) together with removal of occlusion significantly promoted the recovery of the polysynaptic reflex potential. Morphine (5 mg/kg) showed no particular effect on the recovery of potentials. Furthermore, pretreatment with morphine (5 mg/kg) did not influence the effects of these opioid antagonists. These results suggest that naloxone and levallorphan may preserve or potentiate the interneuronal activities of the lumbo-sacral spinal cord under the ischemic condition and that the effects may not be mediated through morphine-like opioid receptors.

Animals↗
PubMed1992

Differential diagnosis of hepatic tumors (hepatoma, hemangioma, and metastasis) with CT: value of two-phase incremental imaging.

Two-phase dynamic incremental CT is a technique in which CT scans are obtained 45 sec and 6 min after commencing the rapid bolus injection of contrast medium. We analyzed the contrast enhancement patterns of three types of hepatic tumors (72 hepatomas, 39 hemangiomas, and 28 metastases) in 139 patients to determine if any differences in the patterns are useful in the differential diagnosis of these lesions. Dynamic incremental CT scanning was performed after 100 ml of iodinated contrast material was administered i.v. with a power injector at a rate of 2 ml/sec. A 1-sec scanning time was used with a 1.6-sec inter-scan delay, which allowed table motion between scans. CT scans (eight to 16 sections) were obtained 45-110 sec (early phase) and 6-7 min (delayed phase) after commencing the injection of contrast medium. The enhancement patterns of hepatomas were as follows: 32% were totally hyperdense in the early phase and totally hypodense in the delayed phase, while 24% were totally hypodense in both phases. Most of the hepatomas (88%) appeared as totally hypodense lesions in the delayed phase. In the case of hemangiomas, 56% were peripherally hyperdense in the early phase; in the delayed phase, 36% were isodense and 31% were totally hyperdense. Most hemangiomas (85%) were not totally hypodense in the early phase, and no hemangioma was totally hypodense in both phases. In the early phase, 61% of metastases were hypodense. In the delayed phase, 57% were hypodense. Metastases most commonly were totally hypodense in both phases (43%). We conclude that contrast enhancement patterns of hepatomas, hemangiomas, and metastases seen on two-phase dynamic incremental CT scans are useful in the differential diagnosis of these tumors.

Carcinoma, Hepatocellular↗
PubMed1992

[Left ventricular diastolic function in apical hypertrophic cardiomyopathy].

To investigate left ventricular (LV) diastolic function in patients with apical hypertrophic cardiomyopathy (AHCM), we analyzed the LV cineangiograms (RAO 30 degrees) and pressures (tip manometer) in 11 patients with AHCM who had giant negative T waves on their electrocardiograms and "ace of spades" configurations on the LV angiograms. Ten patients with non-obstructive HCM (HNCM) and 10 normal subjects served as controls. LV volumes and instantaneous rates of LV volume changes were derived from frame-by-frame analyses of their LV angiograms. LV isovolumic relaxation was assessed according to the time constant (T) of LV pressure decay. LV diastolic distensibility was evaluated by plotting diastolic pressure-volume curves. There was no significant change in the LV systolic functions among these 3 groups. Compared with normals, LV end-diastolic pressure was equally elevated in AHCM and HNCM. The T of isovolumic pressure decay was significantly prolonged in AHCM and HNCM. LV early diastolic filling was maintained at the normal level in AHCM as assessed by the peak filling rate (PFR) during the rapid filling period and the time from end-systole to PFR. The LV diastolic pressure-volume relation shifted upwards in both AHCM and HNCM. In conclusion, impaired LV isovolumic relaxation and decreased diastolic distensibility, which are associated with HNCM, may also be present in AHCM.

Adult↗
PubMed1992

[The effect of heart rate on the time constant of isovolumic relaxation of the left ventricle].

A time constant (T) of the left ventricular isovolumic relaxation, which expresses the relaxation rate of the left ventricle, may be affected by change of the heart rate. There are few clinical reports concerning the relationship between T and heart rate. We studied the relationship between T and heart rate in 10 patients with normal coronary arteries and left ventricular function. Left ventricular pressure was measured using a catheter-tip manometer during right atrial pacing, which was performed at the rate of 10, 20, 40 beats/min in addition to the baseline rate, and finished at 140 or 150 beats/min. Two measurements were made for T.1) Tw from the slope of In (pressure) against time, and 2) Tb by exponential analysis which also estimated the asymptote. As the heart rate increased, both Tw and Tb gradually shortened (Tw: from 38.5 +/- 4.9 msec at the control heart rate to 28.9 +/- 5.6 msec at 140 or 150 beats/min; Tb: from 54.7 +/- 11.4 msec at the control heart rate to 34.9 +/- 5.7 msec at 140 or 150 beats/min). These findings suggest that left ventricular isovolumic relaxation is strongly affected by change of the heart rate in man.

Adult↗
PubMed1992

Clinical assessment of tumor clearance during radiotherapy as a prognostic factor of early glottic carcinoma.

From 1967 through 1985, 358 cases of early glottic carcinoma were treated with telecobalt therapy at the Department of Radiology, Osaka University Medical School. Among 278 cases treated with 2 Gy a day, the tumor response of 262 cases at 40, 50 and 60 Gy were evaluated by direct or indirect laryngoscope. The five-year local control rates of these evaluable cases of T1 and T2 glottic carcinoma were 79% and 70%, respectively. The local control rates of T1 glottic carcinoma with tumor clearance and persistence at 40 Gy were 83% (119/143) and 64% (43/67), and those of T2 cases were 86% (18/21) and 58% (18/31), respectively. The local control rates of the cases with tumor clearance and persistence at 40 Gy were same between T1 and T2 cases. The tumor clearance rates of T1 cases were significantly higher than those of T2 cases (p < 0.005). T2 glottic carcinoma had larger tumor volumes and slower tumor regression and resulted in lower control rates compared with T1 glottic carcinoma. The difference in the radiation dose of T1 and T2 glottic carcinoma with the same clearance rate was estimated as 15 Gy using logit analysis.

Actuarial Analysis↗
PubMed1992

Phase I/II study of high-dose rate interstitial radiotherapy for head and neck cancer.

From July 1991 through December 1991, a phase I/II study of high-dose rate interstitial radiotherapy for head and neck cancer was performed to determine any acute adverse effects and mucosal reaction as well as the feasibility of this therapy. A total of seven patients with head and neck cancer (tongue: four cases; mouth floor: one case; buccal mucosa: one case; oral mucosa of lower lip: one case) were entered into this study. The dose schedule of high-dose rate interstitial radiotherapy ranged from 35 Gy/ten fractions (bid)/week to 60 Gy/ten fractions/week. No major or minor early complication was observed. Spotted mucositis appeared starting three days after the end of high-dose rate interstitial radiotherapy while confluent mucositis developed and approached a peak at ten days but disappeared by the fourth to eighth week. Early tumor responses of all patients were complete.

Adult↗
PubMed1992

Incidence of other primary cancers in 1,569 patients with pharyngolaryngeal cancer and treated with radiation therapy.

From January 1977 through December 1989, a total of 1,569 patients with pharyngolaryngeal cancer (oropharynx: 240, nasopharynx: 221, hypopharynx: 246, and larynx: 862) were treated at the Department of Radiology, Osaka University Hospital and the Department of Radiation Therapy, The Center for Adult Diseases, Osaka. The incidence of other primary cancers in these patients was investigated using the data base of radiation therapy combined with information from hospital-based and Osaka prefectural cancer registries. One hundred and seventy-six of the 1,569 patients (11%) had other primary cancers (oropharynx: 21%, nasopharynx: 7%, hypopharynx: 13%, and larynx: 9%). The time of development of other primary cancers in more than 50% of the cases ranged between one year before and one year after the diagnosis of primary pharyngolaryngeal cancer. The expected number of the second primary cancer was estimated by multiplying the age-sex specific incidence rates for Osaka residents with person-years at risk based on Osaka prefectural cancer registry data. The observed/expected (O/E) ratios were 3.17 (p less than 0.01) for oropharyngeal, 2.01 (p less than 0.01) for nasopharyngeal, 2.16 (p less than 0.01) for hypopharyngeal and 1.10 (n.s.) for laryngeal cancer. The most common sites of the second primary cancer in order of frequency were: the oral cavity and pharynx, esophagus and lung for oropharyngeal cancer, the oral cavity and pharynx for nasopharyngeal cancer, the oral cavity and pharynx and the esophagus for hypopharyngeal cancer and the oral cavity and pharynx, esophagus and lung for laryngeal cancer.

Age Factors↗
PubMed1992

[An autopsy case of Degos disease with neurological symptoms--neuropathological observations and increased platelet aggregation].

We reported clinical and neuropathological observations of a 41-year-old man with Degos disease. He first noted painless skin lesions over the upper extremities in January, 1982. Three years later he was diagnosed as Degos disease by skin biopsy, and treatment with aspirin was started. In September, 1985, he complained of paresthesia on his right arm, followed by a series of new neurological manifestations suggesting multifocal spinal cord lesions. On October 28, examination of admission showed papules with central umblication over the whole body except the head, face, palms, soles and scrotum. Neurological examination revealed no weakness, diminished right biceps reflex, exaggerated patellar reflexes and Achilles reflexes, left extensor plantar reflex, hypesthesia and hypalgesia to the level of Th8, mild left spastic gait, and retention of urine. In November, he had paraparesis, loss of vibration sense of lower extremities, hypesthesia and hypalgesia to the level of TH4, and weakness of right upper extremity. In December, he showed tetraplegia, left-sided facial palsy, and hypesthesia and hypalgesia to the level of C5. In January, 1986, he showed right facial palsy, left facial hypesthesia, pseudobulbar palsy. In February, he had bilateral abducens nerve palsy and hiccups. On February 18, he died of intracranial hemorrhages. He had episodic abdominal pain several times during admission. His condition deteriorated progressively in four months after the first manifestation of neurological symptoms, despite the therapy with heparin, urokinase, ticlopidine, dipyridamole, and prednisolone. Laboratory studies showed gradual increase of CSF proteins (from 156 mg/dl to 602 mg/dl) and extremely increased platelet aggregation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

A unique pattern of astrocytosis in the primary motor area in amyotrophic lateral sclerosis.

We examined the primary motor area (PMA, Brodmann area 4) from 23 cases of adult-onset sporadic amyotrophic lateral sclerosis (ALS) with immunocytochemistry using anti-glial fibrillary acidic protein antibody. There was astrocytosis in the middle of the pyramidal cell layer in all cases except for one that did not present any upper motor neuron signs clinically. The astrocytosis was characterized by multiple clusters of astrocytes, some of which showed a close association with macrophages. In about a half of the cases, these multiple clusters of astrocytes became confluent and presented as a laminar astrocytosis in the middle of the pyramidal cell layer. Our studies demonstrate a unique pattern of astrocytosis in the PMA in ALS. This pattern of astrocytosis may be useful not only for diagnostic purposes, but also for a better understanding of the pathological process involving the PMA in ALS.

Amyotrophic Lateral Sclerosis↗
PubMed1991

Onion bulb formation in the initial complex of neurons in human dorsal root ganglion: their significance and alterations in amyotrophic lateral sclerosis.

We have demonstrated onion bulb-like structures in human dorsal root ganglia (DRG). These onion bulbs morphologically consist of non-continuous layers of supporting-cell cytoplasms that encase thinly myelinated axons and are immunocytochemically recognized by anti-S-100 protein and anti-glial fibrillary acidic protein antibodies. These structures are present in normal controls and preferentially involve the initial complex of the large, light, neurofilament-rich neurons. The number of onion bulbs and their average number of lamellae reach a peak in the third decade and then decline. In three cases of amyotrophic lateral sclerosis (ALS), the onion bulbs involve non-myelinated axons as well as the thinly myelinated portion of the initial complex and are increased both in frequency and in average number of lamellae. Our studies suggest that these onion bulbs represent a normal biological process of DRG neurons that may be accentuated in ALS.

Amyotrophic Lateral Sclerosis↗
PubMed1991

Immunocytochemical and ultrastructural studies of Werdnig-Hoffmann disease.

Neuronal alterations in two cases of Werdnig-Hoffmann disease (WH) were investigated immunocytochemically and ultrastructurally. Ballooned neurons (BNs) were found in anterior horn, Clarke's column, dorsal root ganglion and thalamus. Anti-phosphorylated neurofilament antibodies preferentially stained the peripheral perikarya and proximal neuronal processes of BNs, whereas anti-ubiquitin antibodies preferentially stained the central perikarya of BNs. Ultrastructurally, BNs showed degenerative changes ranging from a diffuse increase of neurofilaments to a centrally accentuated accumulation of mitochondria and vesicular or membranous profiles. Our studies suggest that ubiquitinated degradation products accumulate in the center of the BN's perikaryon and displace aberrantly phosphorylated neurofilaments to the periphery. BNs in WH probably reflect an intrinsic alteration in the metabolism of neurofilaments that is associated with regressive changes in the neuron and eventually neuronal death.

Brain↗
PubMed1991

High-level secretion of human apolipoprotein E produced in Escherichia coli: use of a secretion plasmid containing tandemly polymerized ompF-hybrid gene.

A gene encoding the mature form of human apolipoprotein E (h-apoE) was fused to the secretion signal coding sequence of the Escherichia coli major outer membrane protein F (ompF) which was preceded by a consensus Shine-Dalgarno sequence. Two copies of this hybrid gene were inserted tandemly into an expression vector and expressed in E. coli under the transcriptional control of two tac promoters regulated by lac repressors. By the addition of isopropyl-beta-D-thiogalactopyranoside (IPTG) to the growth media, cells synthesized h-apoE at the level of 27.2 micrograms per A600 and up to 22% of the total cellular protein. The h-apoE produced by E. coli was processed precisely, secreted into the periplasmic space and formed protein aggregates there. However, despite aggregation, they were easily dissolved in water and actively formed protein-lipid complexes with dimyristoyl phosphatidyl choline (DMPC). These results demonstrated that E. coli cells are able to synthesize and secrete a large amount of active h-apoE using a prokaryotic signal sequence.

Amino Acid Sequence↗
PubMed1991

Post-mortem diagnosis of human T lymphotrophic virus type-1 (HTLV-1) associated myelopathy by detection of HTLV-1 DNA in the spinal cord of a patient with post-transfusional myelopathy.

Human T lymphotrophic virus type-1(HTLV-1) is thought to be an etiological agent of HTLV-1 associated myelopathy (HAM). Therefore, a definitive diagnosis of HAM can not be made if information on the presence of antibody against HTLV-1 is not available, even though clinical and histopathological features strongly indicate the disease. In this study, HTLV-1 DNA was detected in the formalin-fixed, paraffin-embedded spinal cord of an autopsy case with post-transfusional myelopathy using the polymerase chain reaction (PCR). Ante-mortem HAM was not suspected of and the antibody has not been examined. Neuropathological examination of the sequential sections revealed a loss of axons and myelin sheaths in the white matter, resembling the histopathology of HAM. The post-mortem detection of HTLV-1 DNA by PCR may be useful for the confirmation of HAM in cases which were not provided with appropriate clinical data.

Autopsy↗
PubMed1991

Posterior fossa epithelial cyst of ectodermal origin.

The case of a large ventral cyst of the posterior fossa of probable ectodermal origin in a 33-year-old patient is presented. Intracranial epithelial cysts are rare, and their histogenesis is a subject of controversy. Previous reports have hypothesized either a neuroepithelial or endodermal origin for the majority of these cysts. This case is unusual because it is the first case, to our knowledge, where melanocytes and melanin have been demonstrated within the cyst wall. These findings suggest an ectodermal origin for this cyst.

Adult↗
PubMed1991

[Analysis of left ventricular pulsus alternans in hypertrophic cardiomyopathy].

We analyzed left ventricular (LV) pulsus alternans in 49 patients with hypertrophic cardiomyopathy during cardiac catheterization. LV pulsus alternans was noted in 6 of 17 patients with hypertrophic obstructive cardiomyopathy, 5 of whom already showed intraventricular pressure gradient at rest. No patient with hypertrophic non-obstructive cardiomyopathy had LV pulsus alternans. Pulsus alternans was neither observed in the right ventricle nor in the pulmonary artery. There was little, if any, pulsus alternans in a low pressure LV chamber (subaortic portion) and peripheral artery during LV pulsus alternans in a high pressure chamber. LV end-diastolic pressure also remained unchanged during LV pulsus alternans, except in one case. It is suggested that LV pulsus alternans in hypertrophic obstructive cardiomyopathy may imply LV dysfunction associated with increased afterload.

Adult↗
PubMed1991

[Correlations between redistribution areas observed on exercise thallium-201 myocardial SPECT images and the coronary collateral circulations in patients with myocardial infarction].

The significance of coronary collateral circulation for redistribution in the infarcted zone was evaluated in 16 patients with history of myocardial infarction and severe stenosis (> or = 90%) of the coronary artery. Redistribution areas were quantitatively measured using the redistribution ratios and redistribution indices on the infarction-redistribution map obtained by thallium-201 scintigraphy with single photon emission computed tomography. Coronary collateral findings were categorized in 4 classes according to the Rentrop's grading. There was good, positive linear correlation between the redistribution ratio (Y) and collateral grading (X) (Y = 0.21X + 0.10, r = 0.92, p < 0.01). The redistribution index (X) also correlated well with the collateral grading (Y) using a good, positive quadratic equation (Y = 0.32X2 + 0.24X + 0.04, r = 0.89, p < 0.01). These results suggest that the measurements of the redistribution areas in the ischemic zone in myocardial infarction correlated well with collateral perfusion. Collateral perfusion severer than Rentrop's grade 2 markedly reduces the severity of ischemia and increases redistribution areas.

Collateral Circulation↗