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Biomedical subjects

M Osawa

Publications and source records attributed to M Osawa.

At least 199 records · Page 11Linked to original sources
PubMed1994

Effects of sevoflurane on central nervous system electrical activity in cats.

We analyzed the effect of a new volatile anesthetic, sevoflurane (2%-5% in oxygen) on the electroencephalogram (EEG) of the neocortex, amygdala, and hippocampus, cortical somatosensory evoked potential (SEP), and brainstem reticular multiunit activity (R-MUA) in cats. Sevoflurane suppressed the background activity of the neocortex more than the amygdala and hippocampus. With increasing concentration of sevoflurane, the cortical EEG progressed from high-amplitude slow waves to a suppression-burst pattern, which was followed by an isoelectric pattern and then spikes with isoelectricity. The amplitude of the SEP was augmented and the R-MUA was suppressed by sevoflurane in a dose-related manner. Repetitive peripheral electrical stimulation induced generalized seizures at 5% sevoflurane in 2 of 13 cats. These results suggest that sevoflurane suppresses the background central nervous system electrical activities in a dose-related manner, leaving the reactive capabilities facilitated at deep anesthesia.

Anesthetics↗
PubMed1994

Soluble sperm extract triggers inositol 1,4,5-trisphosphate-induced Ca2+ release in the oocytes of the sea urchin, Anthocidaris crassispina.

The substance in sperm which induces the activation of eggs at fertilization has yet to be elucidated. Osawa et al. reported that the soluble extract of sperm (spex) causes inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release (IICR) in fertilized eggs of sea urchins when externally applied [Osawa et al., (1992). Zool. Sci. 9: 1206a]. This paper reports that spex also caused IICR in immature oocytes of Anthocidaris crassispina at their germinal vesicle stage and induced a transient increase in their intracellular Ca2+ concentration (Cai-transient). The peak value of this Cai-transient was 160 +/- 16 nM, a small increase by about 60 nM from the basal intracellular Ca2+ concentration, [Ca2+]i, of 96 +/- 12 nM. This reaction was completely blocked by heparin, an IICR inhibitor. Furthermore, the active factor in spex was resistant to pronase and did not show species specificity. It was found that Cai-transient can also be induced in oocytes by sperm. The peak value of the Cai-transient in this case was dependent on sperm concentration and was a maximum of approximately 250 nM, which was significantly lower than that at normal fertilization, i.e., 941 +/- 136 nM. The Cai-transient induced by sperm in oocytes was not suppressed, though its time course was delayed, by heparin.

Animals↗
PubMed1994

Sudden death of a cocaine abuser.

We report an autopsy case of a 28-year-old male who died after intravenous use of cocaine. Cocaine and ecgonine methyl ester, the major metabolite of cocaine, were detected in the blood with gas chromatography/mass spectrometry. Postmortem examination showed contraction band necrosis together with patchy fibrosis and inflammatory cell infiltration in the heart. The sudden death appeared to be caused by a cardiac disorder associated with arrhythmia or coronary vasoconstriction.

Adult↗
PubMed1994

Cloning and sequence analysis of cDNA encoding rabbit vitamin D-binding protein (Gc globulin).

The cDNA sequence of rabbit vitamin D-binding protein (DBP) was determined by sequencing clones isolated by immuno-screening and PCR amplification from a rabbit liver cDNA library. The 1641-nucleotide sequence included the 5' untranslated region and extended to the poly(A) tail. It encoded a protein of 460 amino acid residues in addition to a signal sequence of 16 residues, and had 84%, 79% and 78% sequence identities with human, rat and mouse DBP cDNA, respectively. In comparison with DBP amino acid sequences of other species, there are at least four heterogeneous regions. In contrast, a putative actin binding domain was conserved in the evolution process.

Amino Acid Sequence↗
PubMed1994

[Evaluation of oxygen insufflation to non-ventilated lung during one-lung anesthesia].

To prevent hypoxemia during one-lung anesthesia, we have devised an oxygen insufflation machine which can insufflate oxygen (0.2-10 l.min-1) and apply CPAP (0-30 cmH2O) selectively to the non-ventilated lung. In all the 8 patients, arterial oxygen tension was maintained above 100 mmHg by using this machine, and was increased significantly from 76.2 +/- 11.2 mmHg (mean +/- SD) during one-lung anesthesia to 118.9 +/- 25.2 mmHg during the use of this machine. In conclusion, the machine prevents hypoxemia effectively during one-lung anesthesia without hindering surgical manipulations.

Aged↗
PubMed1994

[Postnephrectomy arteriovenous fistula--surgical experience of a complicated case by renal dysfunction and congestive heart failure].

Postnephrectomy arteriovenous fistula is a rare complication. Twenty nine years after the left nephrectomy due to renal tuberculosis, a 71-year-old male who had suffered from heart and renal failure was diagnosed as postnephrectomy arteriovenous fistula. Ligation of left renal artery and division of left renal vein were performed. Although CVP improved from 30 to 14 cmH2O after operation, cardiac function did not show remarkable improvement, and we were necessitated to introduce hemodialysis from the third week after operation. It is important to bear in mind this complication in order to make early diagnosis and treatment.

Aged↗
PubMed1994

[A case of congenital muscular dystrophy associated with hydrocephalus--CSF dynamics and surgical treatment].

A case of Fukuyama-type congenital muscular dystrophy (FCMD) associated with hydrocephalus was reported. A 15-month-old male, diagnosed as FCMD at 4 months old, revealed progressing large head. CT scan and MRI indicated not only lissencephaly II classified by Dobyn, but dilated ventricular system and subarachnoid space, and these findings radiologically resembled those of brain atrophy. Intracranial pressure and CSF dynamics monitoring revealed high intracranial pressure and high CSF outflow resistance, indicating a high pressure hydrocephalus. V-P shunt made the patient improved not only symptomatically, but physiologically (increased CBF and decreased intracranial pressure and CSF outflow resistance). We concluded that the early diagnosis and treatment of hydrocephalus superimposing the organic disease may prevent secondary damage of the brain, and the intracranial pressure and CSF dynamics monitoring is essential for its diagnosis.

Cerebrovascular Circulation↗
PubMed1993

Human erythrocyte band 3 (EPB3) polymorphism: analysis of blood and bloodstains by an immunodetection method and frequency of the EPB3* Memphis variant.

The erythrocyte band 3 (EPB3) variant, band 3 Memphis (EPB3*Memphis), was detected by immunoblotting with a monoclonal antibody to the 41 kDa cytoplasmic N-terminal domain of band 3 without protease treatment of erythrocytes. EPB3*Memphis was also detected by immunoblotting from 3-month-old bloodstains subjected to alpha-chymotrypsin treatment. A population genetic study using this method indicated that the EPB3 variant would be useful for forensic work in Japan, since the frequency of this variant in Japanese (Wakayama prefecture) is relatively high (0.159).

Anion Exchange Protein 1, Erythrocyte↗
PubMed1993

ABO blood grouping of bloodstains by sandwich ELISA using monoclonal antibody specific for human red cell band 3.

ABO blood grouping of human bloodstains was performed by a sandwich ELISA using a species-specific monoclonal antibody to the amino-terminal cytoplasmic domain of human red cell membrane band 3. In a blind trial, all A, B and O bloodstains (a 1 cm long thread) and AB bloodstains (a 1.5 cm long thread) were accurately typed by this method. Even when bloodstains were contaminated by other body fluids (e.g., semen and saliva), only the ABO blood group epitopes on band 3 of the red cell membrane were detected. Thus, identification of human blood and ABO blood grouping of bloodstains which were contaminated by other body fluids could be simultaneously performed by this method.

ABO Blood-Group System↗
PubMed1993

Comparison of CNS effects of propofol and thiopentone in cats.

Using cats with chronically implanted brain electrodes, we have compared the effects of propofol on CNS electrical activities with those of thiopentone. Ten cats were allocated to receive either propofol (n = 5) or thiopentone (n = 5). Cats were anaesthetized initially with 4% halothane in oxygen. The trachea was intubated and the lungs ventilated mechanically. A femoral artery and a vein in a forepaw were cannulated for arterial pressure monitoring and fluid infusion. After the inspired concentration of halothane was maintained at 0.5%, EEG in the cortex, the amygdala and the hippocampus, somatosensory evoked potential (SEP) and reticular multi-unit activity (R-MUA) were recorded. Incremental doses of propofol or thiopentone were administered i.v. at 5-min intervals during 0.5% halothane anaesthesia. The cumulative doses of propofol and thiopentone were 2, 5, 10 and 20 mg kg-1, and 4, 10, 20 and 40 mg kg-1, respectively. Arterial pressure was maintained in excess of 100 mm Hg systolic by infusion of phenylephrine. All cats in the propofol group survived, but two in the thiopentone group died after the administration of thiopentone 40 mg kg-1. Changes observed in CNS activity were dose-related in all cases. The EEG changed with the increments of doses of propofol or thiopentone, from fast, small amplitude to complexes of fast and slow, large amplitude activities, burst suppression and flat EEG. SEP latency was prolonged by both agents: the peak latency of N1 changed from 15 (SD 2) ms to 20 (5) ms with propofol 20 mg kg-1, and from 14 (1) ms to 27 (2) ms with thiopentone 40 mg kg-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1993

Ependymal abnormalities in lissencephaly/pachygyria.

The ependyma was examined in eight children with neuroblast migratory disorders of diverse origin: three cases of lissencephaly type 1 with severe to mild degrees of agyria/pachygyria, four cases of lissencephaly type 2 in Fukuyama muscular dystrophy and the Walker-Warburg syndrome, and one case of hemimegalencephalic pachygyria. Morphological and immunohistochemical abnormalities of the ependyma were strikingly similar in all. Discontinuities were disproportionate to the degree of ventriculomegaly. In some regions, the ependyma remained a pseudostratified columnar epithelium, though basal processes were absent. The poles of the horns of the lateral ventricles were replaced by extensive heterotopic ependymal rosettes. Rosettes and rows of ependyma also were in other subventricular sites. Subependymal nodules of large astrocytes and their processes bulged into the ventricular lumen after infancy. Ependymal cells did not express glial fibrillary acidic protein, but showed persistent expression of S-100 protein, cytokeratin CK-904 and sometimes vimentin long after these proteins normally disappear. An abnormal ependyma in lissencephaly/pachygyria may contribute to disturbances in neuronogenesis, guidance of axonal projections and neuroblast migrations; it may be a primary factor in pathogenesis.

Brain↗
PubMed1993

Functional image of dynamic computed tomography in diagnostic and prognostic evaluation of ischemic stroke within the first 6 hours.

BACKGROUND AND PURPOSE: It is important to make a diagnosis before a low-density area appears on computed tomography for appropriate management of acute ischemic stroke. We report the diagnostic and prognostic usefulness of functional image of dynamic computed tomography for acute ischemic stroke. METHODS: Forty-seven patients with ischemic strokes within 6 hours of ictus underwent dynamic computed tomography in which functional images were obtained. These findings were compared with angiographic findings, follow-up computed tomography, and clinical outcome. RESULTS: The functional images were categorized into three groups: (1) cortical type: abnormalities on time to peak image and/or corrected mean transit time image involving mainly cortical structures (29 cases); (2) noncortical type: abnormalities on either or both images limited to noncortical structures (7 cases); and (3) normal type: no abnormalities on both images (11 cases). Cortical type as a diagnostic test for arterial trunk occlusion had a good sensitivity (100%), specificity (95%), and accuracy (98%). Infarction volume on follow-up computed tomography correlated with extension of prolonged time-to-peak area (r = .80, P < .01) and that of prolonged corrected mean transit time area (r = .81, P < .01). Cortical type was associated with significantly unfavorable outcome (P < .01). CONCLUSIONS: Functional image of dynamic computed tomography findings predicted arterial trunk occlusion, infarction volume, and clinical outcome. Therefore, this technique would be useful not only for indicating definitive angiography and subsequent therapy but for evaluating the effectiveness of surgical or medical recanalization.

Acute Disease↗
PubMed1993

Extramedullary plasmacytoma producing biclonal gammopathy.

A case of extramedullary plasmacytoma presenting with biclonal gammopathy is reported. The patient was an 82-year-old man in whom monoclonal-protein (M-protein) was not noted during his first hospitalization. On his second hospitalization generalized lymph node swelling and biclonal gammopathy (IgG-kappa, IgA-kappa) were observed. Histological findings were compatible with those of extramedullary plasmacytoma. In the terminal stages, the patient became cachexic. The autopsy disclosed dissemination of the plasmacytoma. Only two other cases have been reported in the literature, and a review of these previous reports is included.

Aged↗
PubMed1993

Heterogeneity of CD7+ 4- 8- 1- leukemia: usefulness of cytoplasmic antigen detection for subclassification.

We identified CD3 and myeloperoxidase (MPO) antigens in the cytoplasm of leukemic cells from 15 patients with CD7+ 4- 8- 1- leukemia. Seven patients, five of whom had a mediastinal mass, had only cytoplasmic CD3 (cCD3) antigen; these seven were regarded as possibly being of T-lineage type. Six patients, one of whom had a mediastinal mass, showed both cCD3 and MPO; they were considered to have mixed lineage type. Two patients had neither cCD3 nor cytoplasmic myeloid antigens; they were therefore considered to have stem cell type. These two latter types were considered as the subgroups: mixed lineage or stem cell type. Patients with T-lineage type were good responders to L-17M therapy; four out of five who received L-17M therapy achieved complete remission. There were significant differences between the two subgroups in relapse-free survival, patients with T-lineage type exhibiting better prognosis than other types (p < 0.05).

Adult↗
PubMed1993

[Tetralogy of Fallot with aortopulmonary window: report of a successful repair].

Tetralogy of Fallot is rarely associated with aortopulmonary window. A 6-month-old boy with tetralogy of Fallot, aortopulmonary window, pulmonary atresia, patent left superior vena cava and right aortic arch was operated successfully. Both great arteries were divided, the defect in the aortic wall was closed directly, and the defect in the pulmonary arterial wall was connected with a valved external conduit which was used for right ventricular outflow tract reconstruction. Although oliguria had been prolonged for 3 weeks post operatively, he recovered completely and RV/LV pressure ratio was less than 0.6 estimated by two-dimensional echocardiography at one month after operation.

Aortopulmonary Septal Defect↗
PubMed1993

[Movement disorders in HTLV-I associated myelopathy (HAM)].

Periodic movements in sleep (nocturnal myoclonus) are characterized by a triple flexion of the ankle, knee and hip, which are particularly evident during 1-2 and 2-3 sleep stages. Iijima et al (1991) reported these movements in 5 out of 7 HAM patients, suggesting that nocturnal myoclonus is not rare in HAM. L-dopa and bromocriptine are reported to be the most effective. Spinal myoclonus (SM) is characterized by symmetric, rhythmic involuntary contractions of muscle groups supplied by one or several contiguous segments of the spinal cord. There has been only one case report of SM by Kanda et al (1988). Clonazepam and tetrabenazine are reported to be the most effective. Tremor is characterized by a sinusoidal oscillatory movement produced by synchronous or alternating contractions of reciprocally innervated antagonist muscles. Postural finger tremor was seen in about 40% of HAM patients (Suwazono et al, 1989). Painful, paroxysmal muscle contractions of the lower limbs were reported in only one patient with HAM by Ikeda et al in 1990. Based on electrophysiological findings, they were thought to be caused by reciprocal excitation in the spinal cord.

Clonazepam↗