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Biomedical subjects

M Kagawa

Publications and source records attributed to M Kagawa.

At least 127 records · Page 7Linked to original sources

[Arteriovenous malformation. 3. Dynamic CT of arteriovenous malformation].

Various methods have been reported for the purpose of measurement of hemodynamics of the cerebral arteriovenous malformations. In this paper, using a TCT-60A-30 scanner, dynamic computed tomography was performed on 18 cases with arteriovenous malformations. The initial scan of the dynamic CT was started simultaneously with the start of an intravenous injection of uniodinated contrast medium (8 ml/sec.), serial 4.5 sec. scan repeated 8 times. The data for each scan were segmented into three, and a series of 24 rapid-sequence scan images (CT-angiography) was generated. The time-density curve by use of Thompson's methods was analyzed with multiple ROIs which were bilaterally set up for the nidus and its surrounding areas considering each arterial supply. And the flow parameters, such as the peak concentration (PC), the mean transit time (MTT) and the PC/MTT were calculated. We thought that under the condition of normal state of blood-brain-barrier and fixed standards of multiple factors such as the cardio-pulmonary function, systemic blood volume, viscosity of the blood and many others, PC manifested vascular beds of ROIs, MTT brain circulating time, PC/MTT blood flow respectively. In the ROIs of the nidus, high values of PC (115.7 +/- 51.9 CT number) and PC/MTT (14.8 +/- 6.28 CT number/sec.), and reduction of MTT (8.47 +/- 2.28 sec.) were revealed in comparison with surrounding areas. The ROIs of the nidus showed enlargement of vascular beds and blood flow and reduction of brain circulating time. On the other hand, in the ROIs surrounding the nidus, MTT of affected areas (10.33 +/- 2.78 sec.) was slow compared with it nonaffected areas (9.33 +/- 2.09 sec.), however PC and PC/MTT were equal in both areas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[A case report of cerebral venous dysgenesis].

A case classified to "cerebral venous dysgenesis" (Kagawa et al 1972) is reported. A 16-year-old girl was admitted complaining of psychomotor seizure which began seven years before. At the first admission (seven years ago) she was diagnosed as psychomotor seizure and cerebral venous dysgenesis by CT scan, EEG and cerebral angiography. Then she was treated by medication (anticonvulsants) for seven years. At the second admission (this time) left temporal lobectomy was performed by means of monitoring the cortical EEG. CT scan showed atrophy of the left temporal lobe. Spike and wave complex was seen in EEG. Carotid angiography disclosed the abnormal networks among the fine venules and their connection to tortuous and coiling veins. The abnormality was seen in the frontal, parietal, and temporal area. After operation psychomotor seizure has been controlled by medication. Pathologically tortuous vessels, gliosis and arachnoidal fibrosis were shown. This case should be classified to "cerebral venous dysgenesis" differentiated from the venous angioma. Classification of venous malformation, clinical signs, angiographical findings, and genesis were discussed.

Adolescent↗

[Cerebral arteriovenous malformations. 2. A study of cerebral hemodynamics].

Regional cerebral blood flow (rCBF) in 16 patients with cerebral AVM was measured using 133-Xe inhalation cerebrograph, and in 3 patients rCBF was measured using stable xenon enhanced CT. Neurological status and angiographical findings were studied in the connection with rCBF measurement. RCBF in almost patients with hemorrhagic episodes was low in the frontal area (frontal depression). The larger the size of nidus is, the higher the shunt flow through nidus is, therefore, there were no significant difference of mean rCBF between the affected and non-affected hemisphere independently of the size of nidus. But in the area adjacent to AVM nidus, particularly the nidus over 20 cm3 of volume, surrounding ischemic focus was noticed. And it was thought that brain swelling due to the normal perfusion pressure break through may occur when the nidus over 20 cm3 was removed. The reduction of rCBF of the non-affected cerebral hemisphere was noticed in the cases with nearly medical seated AVM and the rCBF reduction of the non-affected or affected hemisphere was noticed in the cases with posterior fossa AVM. There was similarity between the results concerning the hemodynamic status obtained by 133-Xe inhalation cerebrograph and stable xenon enhanced CT. But 133-Xe inhalation cerebrograph was less useful for estimation of cerebral hemodynamics than the stable xenon enhanced CT, because overestimation of rCBF was noticed in 133-Xe inhalation cerebrograph.

Adolescent↗

[A study of cefoperazone levels in the cerebrospinal fluid of patients with hydrocephalus].

Eleven neurosurgical patients without intracranial infection were given 4 g cefoperazone (CPZ) intravenously for 30 minutes. Ventricular drainage was performed in 10 cases, and 1 case with cisternal drainage. Eight of 11 cases showed moderate to severe ventricular dilatation. Serum and ventricular cerebrospinal fluid (CSF) concentrations of CPZ were measured for 8 hours after injection. Average peak serum concentration of CPZ was 476 micrograms/ml and the half-life was 150 minutes. Patients with obstructive hydrocephalus showed relative good penetration of CPZ in CSF (2.74 approximately 5.29 micrograms/ml). Especially, those who had severe dilatation of ventricles demonstrated sequential increased concentration (5.48 approximately 6.25 micrograms/ml at 8 hours). In poor risk patient and intracerebral hemorrhage with ventricular hemorrhage cases, who had normal range of CSF cell counts and protein, CPZ level was low, less than 2 micrograms/ml. In cases with severe subarachnoid hemorrhage, sufficient concentration (11 micrograms/ml) of CPZ was observed in cisternal CSF. The CPZ concentrations in CSF after 4 g administration did not seem to exceed comparing to 2 g dosing.

Aged↗

[Penetration of cefotaxime into human cerebrospinal fluid].

The penetration of cefotaxime (CTX) into the cerebrospinal fluid (CSF) was monitored to evaluate the prophylactic efficacy of the drug against post-craniotomy infections. Doses ranged from 1 to 2 g were administered to patients with subarachnoid hemorrhage due to the rupture of cerebral aneurysm, traumatic cerebral contusion, or subdural edema accompanied by intracerebral hemorrhage, by intravenous drip infusion over a period of 30 or 60 minutes. CTX readily entered the CSF with concentrations exceeding MICs against the major pathogens occurring after craniotomy. CTX proved to be effective in the prevention of post-craniotomy infections in noninflammatory situations, especially after surgery in the case of cerebral traumas or subarachnoid hemorrhage.

Adult↗

[The effect of large dose dexamethasone on local cerebral blood flow (L-CBF) in ischemic rat brain].

Changes of local cerebral blood flow (l-CBF) were estimated by autoradiographic techniques in middle cerebral artery occlusion rats given a large dose of (3 mg/kg) dexamethasone. The sensory-motor, parietal, auditory and olfactory cortices showed a significant reduction (greater than 25%) of l-CBF. In MCA occlusion with large dose dexamethasone group, ischemic cortices showed significant reduction from the only MCA occlusion group (highest 36%). There was no significant reduction of l-CBF in the deep structures. The effects of dexamethasone on drains with various pathologies have been studied both clinically and experimentally with many kinds of techniques. These effects are now being reevaluated. Still controversial however, is the mechanism that determines whether dexamethasone has beneficial, non-beneficial, or harmful effect. This study may help us to unravel the mechanism of steroid effects, as well as the relationship between corticosteroid and central nervous system.

Animals↗

In vivo and in vitro studies on cocaine metabolism: ecgonine methyl ester as a major metabolite of cocaine.

The levels of cocaine, benzoylecgonine and ecgonine methyl ester were measured periodically in the urine of dogs and rabbits by gas chromatography-chemical ionization selected ion monitoring mass spectrometry after subcutaneous injection of 2.9 mumol/kg (1.0 mg/kg) cocaine--HCl. Ecgonine methyl ester persisted much longer than benzoylecgonine. Urinary ecgonine methyl ester could be identified for 72 h in all the experimental dogs. The ester accounted for 6.6-27.1% of a dose of cocaine in dogs and 8.8-31.9% in rabbits 24 h after administration. Excretion of benzoylecgonine in urine was 6.3-19.2% in dogs and 7.5-32.9% in rabbits. This confirms that ecgonine methyl ester is one of the major metabolites of cocaine as well as benzoylecgonine. Excretion of the parent drug and its two hydrolyzed metabolites in faeces was very small, less than 1% of administered dose. Tri-o-tolylphosphate and eserine significantly inhibited cocaine hydrolysis to benzoylecgonine and ecgonine methyl ester, respectively. Parathion and EDTA, however, had no effects on cocaine hydrolysis in vivo. In vitro demethylation of cocaine to benzoylecgonine was demonstrated in the plasma from dogs and this production of benzoylecgonine was much more than that of non-enzymatic formation in buffer at physiological pH. It was concluded that a large part of the benzoylecgonine excreted in urine is an in vivo enzymatic product of cocaine. On the other hand, plasma cholinesterase and liver esterase mediated ecgonine methyl ester formation. This liver esterase was abundant in the soluble fraction and could be found in both of microsomal and mitochondrial fractions.

Animals↗

Statistical studies on evaluation of mild disturbance of consciousness. Study of a simpler scale for clinical use.

In an effort to express the grades of mild disturbance of consciousness (MDOC), or clouding of consciousness, 25 items were selected for application in clinical examination. Factor analysis of the 25 items revealed that MDOC has a two-factor structure; namely, the performance factor (F1) and the verbal factor (F2). This structure was maintained in the sequential examinations. Guttman's scale analysis showed that the scale using the 25 items may be considered to approximate a unidimensional scale. By item selection according to communality, the 25 items could be reduced to 12 items without losing the two-factor structure or the usefulness and reliability of the examination. The principal component analysis (PCA) score, the F1 score, and the F2 score, calculated from the 12 items, were found to be good scales to describe an overall picture and characteristics of the F1 and the F2 of MDOC, respectively. Furthermore, by means of the characteristic curve (ogive) method, it was revealed that MDOC consisted of four clusters of items, the F2 factor (mild), F1 factor (mild), F2 factor (moderate), and F1 factor (moderate), according to the MDOC severity, so that a simpler scale composed of a representative item from each cluster could be constructed which exhibited a high correlation coefficient with the original PCA score.

Brain Diseases↗

Brain abscess in congenital cyanotic heart disease.

Sixty-two cases of brain abscess with congenital cyanotic heart disease are reviewed. A sharp peak in the age distribution was seen at 4 to 7 years of age. Of 62 cases, 38 (61.2%) had a tetralogy of Fallot, and six had a transposition of the great vessels. The majority of these abscesses were supratentorial and 76% of abscesses were found in the frontal, temporal, and parietal lobes. Multiple abscesses were present in 19.4% of cases. Sterile cultures were obtained in 61% of the abscesses, and the increasing percentage of sterile cultures seems to be the result of broad-spectrum antibiotic therapy. The overall mortality rate was 37% but there were no deaths after surgical excision secondary to aspiration. Since the introduction of computerized tomography, aspiration without total excision has produced good results, and therefore it is believed that the number of cases which are cured with aspiration therapy alone will gradually increase in the future.

Adolescent↗

Paraventricular cerebral cyst in an infant.

The case of a paraventricular cerebral cyst with a partial defect of the corpus callosum is reported. The cyst wall was studied using light and electron microscopy. Electron microscopy revealed that the lining of the cyst consisted by a single layer of epithelial cells. The cells of the cyst wall, which rested on a basement membrane, had microvilli and abnormal cilia, and there were desmosomes between the cells, In accordance with the pathological findings, the cyst was classified as a type transitional between a choroidal epithelial cyst and an ependymal cyst.

Agenesis of Corpus Callosum↗

[Cerebral arterial occlusive disease in children -- clinical aspects and surgical treatment (author's transl)].

In the present study the pathology and treatment of occlusion of cerebral arteries in children were investigated in an attempt to find out an approach to the surgical treatment of cerebral arterial occlusive disease of childhood. We had a total of 55 children with cerebrovascular disorders seen at our Institute during the past 11 years. In this series there were 19 cases of cerebral arterial occlusive disease. The causes in 15 cases of cerebral arterial occlusive disease except for moyamoya disease were heart disease in 7 cases, trauma in 2 cases and unknown in 6 cases. The cerebral arterial occlusive disease had its onset at the age of less than 6 years in 12 of 15 cases. The disease began with hemiplegia of sudden onset. The disease onset was also attended frequently by a convulsive seizure, which distinguishes the condition from that in adults. In 10 of all 15 lesions the site of occlusion was in the distribution of the middle cerebral artery. One case in which there was occlusion of the basilar artery occurring in association with trauma was described in detail. In one instance the treatment consisted of STA-MCA anastomosis. Paroxysmal black out attacks, which had been of frequent occurrence in addition to hemiplegia were relieved postoperatively. In our opinion, STA-MCA anastomosis for cerebral arterial occlusive disease in children should be considered to be indicated only when 1) cerebral angiographic evidence of occlusion or stenosis of a trunk of cerebral artery is still present after the acute stage or 2) no extensive low density area is demonstrable on CT scan. Surgery is generally less indicated in those instances in which the occlusion is due to embolism. However since abscess may arise from such an arterial lesion, surgery should be considered, or at least its feasibility be evaluated, whenever 1) the underlying cardiac pathology well permits surgical intervention and 2) half a year has passed since an initial attack.

Adolescent↗