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Biomedical subjects

Y Hirashima

Publications and source records attributed to Y Hirashima.

At least 109 records · Page 6Linked to original sources
PubMed1989

Fluorimetric coupled enzyme assay for lysoplasmalogenase activity in liver.

We developed a continuous spectrofluorimetric assay of lysoplasmalogenase activity with the use of horse liver alcohol dehydrogenase as a coupling enzyme. In this method the disappearance of NADH is measured spectrofluorimetrically. The excitation and emission monochromators were set at 340 and 460 nm respectively. The assay is 10 times as sensitive as the previous u.v. spectrophotometric method. We could detect approx. 0.02 nmol of aldehyde produced/min per ml.

Alcohol Dehydrogenase↗
PubMed1989

Activities of enzymes metabolizing phospholipids in rat cerebral ischemia.

Ischemic rat brains were prepared by decapitation followed by incubation in an artificial cerebrospinal fluid at various times at 37 degrees C, and the levels of phospholipids, free fatty acids, and enzymes involved in their metabolism were studied. Activities of phospholipase A, phospholipase C, and di- and monoglyceride lipase, assayed with optimal concentrations of Ca2+ and lysophospholipase, did not significantly change by 60 min of ischemia, whereas acylation enzymes of lysophospholipid decreased in activity to an extent of 70% of control at 15 min after the ischemic treatment. The maximal activities were found at 8 x 10(-3)M, 1 x 10(-3) M, and 2 x 10(-2) M Ca2+ for phospholipase A, phospholipase C, and di- and monoglyceride lipases, respectively in microsomal fractions of both control and ischemic brain. Furthermore, the sensitivity of microsomal enzymes to endogenous Ca2+ was estimated in control and ischemic brain. The sensitivity of phospholipase C was found to be increased after 1 min of ischemic treatment, but those of phospholipase A and di- and monoglyceride lipase were not increased.

Animals↗
PubMed1989

Continuous spectrophotometric assay of phospholipase A2 activity hydrolyzing plasmalogens using coupling enzymes.

We developed a continuous spectrophotometric assay of the phospholipase A2 activity specific for choline plasmalogen using rat liver lysoplasmalogenase and horse liver alcohol dehydrogenase as coupling enzymes and Naja naja venom phospholipase A2 as a source of the phospholipase A2 activity. In these coupling reactions, choline lysoplasmalogen is hydrolyzed by lysoplasmalogenase to glycerophosphocholine and free aldehyde. The free aldehyde is quantitatively converted to alcohol by alcohol dehydrogenase with the oxidation of NADH. The disappearance of NADH is measured spectrophotometrically at 340 nm. The assay is sensitive to about 0.2 nmol aldehyde produced/ml/min and also is rapid, convenient, and continuous.

Animals↗
PubMed1989

Posterior inferior cerebellar artery aneurysm associated with fenestration of the vertebral artery--case report.

A 72-year-old male hospitalized for disturbance of consciousness and vomiting was found to have a left vertebral artery fenestration and a left posterior inferior cerebellar artery aneurysm. The aneurysm was successfully clipped through the lateral suboccipital approach and he recovered with minimal deficits. The association of vertebral artery fenestration and posterior inferior cerebellar artery aneurysm is rare, and their etiologies and relationship are discussed.

Aged↗
PubMed1989

[Preventive effect of urinastatin on cisplatin-induced nephrotoxicity].

Anticancer chemotherapy with cisplatin (CDD) as the main drug (combined with adriamycin (ADM) and cyclophosphamide (CPM), PAC therapy) was performed on patients with ovarian cancer. Urinastatin (US) was concurrently administered to assess its effectiveness in preventing CDDP-induced nephrotoxicity. Twenty-two patients with gynecological malignant tumor were treated with PAC therapy, and of these, twelve concurrently received US. The ten who did not receive US served as the control. As a rule, one course of PAC therapy consisted of 50mg/m2 CDDP, 50mg/m2 ADM and 500mg/m2 CPM. Before the administration of CDDP, US 100,000 units was administered by I.V. drip infusion and after the administration, US 400,000 units was again administered by I.V. drip infusion at a speed of 100,000 to 200,000 units/hour. A total of approximately 3,500ml of fluids was administered I.V.. Each course of PAC therapy took 7 to 14 hours to complete. The control group underwent PAC therapy in a regimen not including US. As indexes of nephrotoxicity, serum levels of BUN, creatinine (Cr), and creatinine clearance (Ccr), and N-acetyl-beta-glucosaminidase (NAG), gamma-glutamyl transpeptidase (gamma-GTP), and arylamidase (AA) activity in the urine was determined before treatment and at days 1, 2, 3, 7, 14, and 21 after the initiation of PAC therapy. Changes in serum BUN, Cr, and Ccr levels after CDDP administration in the group with and the group without concurrent US were similar. Urinary gamma-GTP, AA, and NAG activity remained unchanged after CDDP administration in the group with concurrent US. In contrast, in the group without US, this urinary enzyme activity was transiently increased after CDDP administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Deep sylvian meningioma: case report and review of the literature].

A case of intrasylvian meningioma is presented with some considerations to the clinical, radiological, and pathological features of the tumor. A 34-year-old Japanese woman, who had experienced several episodes of fainting attacks since 19 years old, was admitted to our hospital on March 22, 1983. Her plain skull roentgenogram showed abnormal calcification in her left fronto-temporal region. CT scan demonstrated clear-marginal high density mass in the left sylvian fissure which was homogeneously enhanced after administration of contrast medium. Left carotid angiogram showed intrasylvian mass with small tumor stain in late arterial phase, but external carotid artery had no concern with this tumor. On March 30, left fronto-temporal craniotomy was performed. The tumor was located in the extra-axial space of the sylvian fissure without any attachment to the dura mater or to the choroid plexus of the ventricles. This hard tumor, 70 grams in its weight, was successfully removed. It was histologically diagnosed fibroblastic meningioma. The patient was discharged without any neurological deficits. Twenty-four cases of meningiomas not attached to the dura mater or to choroid plexus could be reviewed from the literature. This type of meningioma is occasionally called "deep sylvian meningioma", but in some reports the tumors developed far from sylvian fissure. And even in the cases in which the tumors were reported to be located in the sylvian fissure, macroscopic space where tumors developed was various. The clinical features, diagnosis, and surgical management of this tumor were also discussed in the report.

Adult↗
PubMed1985

[The activities of phospholipase A, PI-specific phospholipase C, lipase, lysophospholipase and acylCoA: lysophospholipid acyltransferase in ischemic brain microsomal fraction].

It has been well recognized that acyl groups of phospholipids play an important role for structure and function of biomembrane. The turnover of these acyl groups in normal brain biomembrane is also well known. Some types of enzymic system related to this turnover has been investigated. Phospholipase A, PI-specific phospholipase C, lipase, lysophospholipase and acylCoA: lysophospholipid acyltransferase belong to these enzymic systems. In this report, the sequential changes of phospholipase A, PI-specific phospholipase C, lipase, lysophospholipase and acylCoA: lysophospholipid acyltransferase activities in ischemic rat brain were examined. The purpose of this study was to examine the enzymic changes of deacylation-reacylation cycle of biomembrane phospholipid in ischemic brain. Ischemic brain were produced by decapitation and activities of 5 enzymes were assayed in microsomal fraction. The activities of phospholipase A, PI-specific phospholipase C, lipase showed high value during early stage of ischemia for 15 or 30 min and then decreased gradually. Lysophospholipase activity was not changed for 120 min. On the other hand, acylCoA: lysophospholipid acyltransferase activity showed gradual decrease from the beginning of ischemia. There are some reports that in early ischemic stage, the concent of free fatty acids increase, while that of phospholipid decrease. The present results may suggest that the changes of free fatty acid and phospholipid in ischemic brain are related to these enzymic system.

1-Acylglycerophosphocholine O-Acyltransferase↗
PubMed1983

Measurement of the area of the anterior horn of the right lateral ventricle for the diagnosis of brain atrophy by CT. Correlation with several ventricular indices.

The area of the anterior horn of the right lateral ventricle and five ventricular indices: (1) maximum width of the anterior horns, (2) minimum width of the anterior horns, (3) sum of these maximum and minimum widths, (4) ventricular index, and (5) cella media index were measured from the CT scans of 198 cases considered to be "normal". The area of the right anterior horn and indices 1-4 were measured on the slice which most clearly showed Monro's foramina and index 5 was measured on the slice 2 cm above. The size of the ventricular system increased steadily with age. The sum of the maximum and minimum widths of the anterior horns was most highly correlated with the area of the right anterior horn. Using this ventricular index, we graded brain "atrophy" in each age group.

Adolescent↗
PubMed1983

[Subdural hematoma due to metastatic dural carcinomatosis associated with DIC--a case report].

This 74-year-old female suddenly complained of severe headache, nausea, vomiting and dizziness on June 19, 1981. She was brought to nearby hospital. During the following six days, the state of consciousness gradually worsened and left-sided hemiparesis and convulsion attack arose and she was admitted to our clinic on June 25, 1981. Cerebral angiograms revealed an aneurysm of the right middle cerebral artery. Diagnosis of subarachnoid hemorrhage due to the rupture of an aneurysm was tentatively made and conservative therapy was done. On the second hospital day, she had nasal bleeding and began to excrete tar-like stool. Laboratory examination revealed thrombocytopenia, increase of FDP and prolongation of prothrombin time. Her liver and renal functions gradually worsened after this episode. On the 13th hospital day, she expired. General autopsy showed wide spread adenocarcinoma with metastases to the lung, lymph nodes and bones. Examination of the head revealed an unruptured aneurysm and bilateral diffuse subdural clotted hemorrhage. The dura was tightly adherent to the skull and partially thickened. No abnormal findings were found in the brain. On microscopical examination of the dura, there were fresh hemorrhage and many of the innumerable dilated small vessels contained tumor in the inner dural layer. Even by extensive examination, the origin of the malignancy could not be identified. We concluded that the initial symptoms just like of subarachnoid hemorrhage were due to the dural metastasis and subdural hematoma. Sixteen cases of subdural hematoma secondary to metastatic neoplasm were reported previously. We made some discussion about the pathogenesis and symptomatology of this type of subdural hematoma.

Adenocarcinoma↗
PubMed1983

[Simplified microdetermination of cerebral phospholipase A1, A2 and lysophopholipase].

The purpose of our study was to examine the ischemia induced enzymatic changes of decaylation-reacylation cycle of membrane phospholipids in dog brain. In this study, we developed new modified method for assay of phospholipase A1, A2 and lysophospholipase which is simpler and needs only a smaller amount of materials. For the first report, we introduced this new method and demonstrated some properties of phospholipase A1, A2 and lysophospholipase in dog brain. Crude enzyme solution for assays of phospholipase A1, A2 and lysophospholipase was gained from extraction of frozen brain with aceton, butanol and saline. The level of phosphorus in the enzyme extract was determined and only those extracts which had a level of phosphorus within a certain range were used. The substrates for assays were L-alpha-[beta-palmitoyl-1-14C] phosphatidylcholine, dipalmitoyl for phospholipase A1 and A2 and L-lysophosphatidylcholine-1-[1-14C] palmitoyl for lysophospolipase respectively. Each radioactive substrates was diluted with cold carrier lipid to give the proper specific activity. Reaction system including substrate, buffer [pH 7.0] and enzyme extract was incubated for 10 hours at 38 degrees C. But for the assay of phospholipase A1 and A2, enzyme solution was pre-incubated at 70 degrees C for 5 minutes. In our new method, reaction mixture was directly separated by TLC without extracting lipids. Enzyme activities were calculated from radio thin-layer chromatograms. Furthermore, we made a comparison between our method and the former one. The value of each enzyme activity was slightly higher in our method than in the former one. However, it was revealed that the results were reproducible in both methods.

Animals↗
PubMed1983

[Activities of phospholipase A1, A2, lysophospholipase and acylCoA: lysophospholipid acyltransferase in ischemic brain of the dog].

In this report, the sequential changes of phospholipase A1, A2, lysophospholipase and acylCoA: lysophospholipid acyltransferase activities in ischemic dog brain were investigated. The purpose of this study was to examine the enzymic changes of deacylation-reacylation cycle of biomembrane phospholipid in ischemia. Hemispheric non-blood supply models were produced by occlusion of main intracranial trunk arteries in dogs according to Suzuki's method. The sample was spooned out and frozen immediately with liquid nitrogen at the predetermined time. The assay of phospholipase A1, A2 and lysophospholipase activities was done by our method and acylCoA: lysophospholipid acyltransferase activity was according to Corbin and Sun's method. The activities of phospholipase A1, A2 and lysophospholipase did not show significant changes within 60 minutes after arterial occlusion. However these activities showed significant high value at 120 minutes and decreased gradually after then. On the other hand, acylCoA: lysophospholipid acyltransferase activity showed gradual decrease. These findings show that enzymic degradiation of acyl group of phospholipid in the brain is highest at about 120 minutes after complete ischemia. The importance of acyl groups of phospholipids for biomembrane structure and the function is well recognized. The turnover of these acyl groups in normal brain biomembrane is also well known. Some types of enzymic system related to this turnover has been investigated. Phospholipase A1, A2, lysophospholipase and acylCoA: lysophospholipid acyltransferase belong to these enzymic systems. There have been some reports that the content of free fatty acids in the ischemic brain increases in early stage.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Acylglycerophosphocholine O-Acyltransferase↗
PubMed1981

CT findings in a case of neonatal acute subdural hematoma.

The CT findings in a case of neonatal acute subdural hematoma are presented. CT demonstrated a crescentic high density area in the subdural space over the left cerebral hemisphere and an oval high density area in the left occipital region. The latter was suspected of being an intracerebral hematoma. Emergency craniotomy revealed that the high density area was due to a subdural hematoma between the occipital lobe and the tentorium cerebelli.

Cerebral Hemorrhage↗
PubMed1981

[A case of acute subdural hematoma in one-day-old baby--with special reference to its CT findings (author's transl)].

The authors describe and discuss a case of acute subdural hematoma originating from the lacerated tentorium of 22 hour-old newborn. CT scan revealed crescent high density area in the subdural space between the left frontal area and the occipital area. Another high density area was seen in the left occipital area which was suspected as intracerebral hematoma preoperatively because of its rather intramedullar location. Large craniotomy was performed 22 hours after delivery, evacuating 70 gm subdural hematoma. Bleeding point was determined as lacerated tentarium about 1 cm length. No intracerebral hematoma was found. Postoperative course was uneventful and he is showing normal development. It is now concluded that supratentorial subdural hematoma originating from tentorial laceration at delivery could be misdiagnosed as intracerebral hematoma on CT scan. Anatomical structure should be always compared when CT scan study is performed.

Acute Disease↗
PubMed1981

[A case of trapped fourth ventricle which developed after a surgery of AVM (author's transl)].

We represent a case of cystic dilatation of the fourth ventricle resulted from obstruction of the foramina of Luschka and Magendie and of the aqueduct of Sylvius which developed after a surgery of AVM. A 42-year-old woman was admitted to our clinic for the operation of AVM located at the trigone of lateral ventricle and the lateral wall of midbrain. VPS had been performed previously because of acute hydrocephalus resulted from several attacks of ventricular hemorrhage. Total removal of the AVM was performed. The patient was stuporous after the surgery, and CT scan showed marked distension of the fourth ventricle with shifted third ventricle and slightly dilated supra-tentorial ventricular system. Although a revision of the abdominal side of VPs performed and the lateral and the third ventricles were shunted effectively, the fourth ventricle continued to show remarkable distension. Since it was considered that the occlusion of the foramina of Luschka and magendie due to previous episodes of ventricular hemorrhage and the blockage of the aqueduct of Sylvius 'trapped' the fourth ventricle, suboccipital craniotomy and re-opening of the foramen of Magendie was performed. The arachnoid membrane around the cisterna magna was strongly adhered to the dura mater. When incision was made on the arachnoid membrane between the cerebellar tonsils, slightly turbid and xanthochromic CSF spurted out and some old clots were also aspirated from the opened fourth ventricle. The size of the fourth ventricle returned normal on CT scan ten days after the operation, and the patient recovered progressively afterwards.

Adult↗
PubMed1981

[An anterior communicating artery aneurysm complicated by chronic subdural hematoma--a case report (author's transl)].

A 53-year-old housewife was admitted to the Department of Neurosurgery, Toyama Medical and Pharmaceutical University on June 6, 1980, because of disorientation, urinary incontinence and left hemiparesis. She had experienced "a fit of severe headache" many times for five years. On May 12, 1980, she experienced an abrupt, severe headache in a lavatory and was immediately brought to a nearby hospital. Her symptom was recovered gradually for a week but she experienced sudden onset of severe headache again on May 20. Subsequently, her state of consciousness gradually worsened and left sided hemiparesis arose. On admission, cerebral angiograms revealed an aneurysm of an anterior communicating artery and a subdural hematoma over the right hemisphere. On the third hospital day, radical operation was performed by bifrontal craniotomy. Neck of aneurysm was ligated and clipped successfully and dark brownish semiliquid contents of chronic subdural hematoma was evacuated. The lacerated portion of arachnoid with some distance from the aneurysm was observed and subarachnoid hemorrhage was thought to enter subdural space through this portion. Post-operative course was uneventful. Nine cases of intracranial aneurysms complicated by chronic subdural hematoma were reported previously, but an anterior communicating artery aneurysm case was not in these cases. We have some discussion about cerebral aneurysms complicated by chronic subdural hematoma, especially about the pathogenesis of chronic subdural hematoma.

Chronic Disease↗