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Biomedical subjects

S Nakatsu

Publications and source records attributed to S Nakatsu.

At least 19 recordsLinked to original sources
PubMed1992

Analysis of the close relationship between human astrocytoma-specific antigens detected by murine monoclonal antibodies and c-kit proto-oncogene product.

Tyrosine-specific phosphorylated proteins found exclusively on the cell surface of human astrocytomas were previously identified with murine monoclonal antibodies, designated as GA-17, GB-4 and GC-3. The purpose of this study was to further characterize the antigens and investigate the relationship between them and c-kit protooncogene product. We demonstrated that the antigens had protein kinase activity. Moreover, GA-17 reacted with c-kit protein expressed on the membrane of A172 human glioblastoma cells.

Antibodies, Monoclonal↗
PubMed1992

Post-translational modification of protein by tyrosine sulfation: active sulfate PAPS is the essential substrate for this modification.

In vitro tyrosine sulfation of recombinant proteins would be a valuable tool in converting those proteins expressed in prokaryotic vectors to their natural form. For this purpose tyrosylprotein sulfotransferase (TPST), the enzyme responsible for tyrosine sulfation of proteins, was characterized from a bovine liver Golgi preparation. TPST was active in a acidic environment with a pH optimum of 6.25, and displayed a stimulation by the Mn2+, with the optimum activity in the presence of 5mM MnCl2. TPST was able to sulfate recombinant hirudin variant 1 (rHV-1) expressed in Escherichia coli and the C-terminal hirudin fragment 54-65 but not the N-terminal hirudin fragment 1-15 by using 3'-phosphoadenosine 5'-phosphosulfate (PAPS), indicating its specificity for the naturally sulfated tyrosine 63. Comparison of the reaction kinetics on synthetic peptides showed that the bovine liver TPST has a higher affinity and reaction rates for those peptides with a aspartyl residue on the N-terminal side of the tyrosine when compared with a glutamyl residue.

Amino Acid Sequence↗
PubMed1991

Malignant meningioma with repeated multiple recurrence. A case report.

A case of malignant meningioma with repeated multiple recurrence was reported. A 22 year-old male first underwent the total removal of left parieto-occipital convexity meningioma in 1965. Although he had lived an uneventful life after the operation, he recognized motor weakness of the left lower limb in April 1985 when he was 41 years old and CT revealed a large tumor in the parieto-occipital parasagittal region. He underwent the total removal of the tumor and cranioplasty on May 23, 1985. After the second operation, repeated recurrence of multiple tumors was seen, which were in the frontal, parietal and occipital convexities, parasagittal regions and falx. He underwent further operations on January 23, 1986, December 11, 1986, March 30, 1987 and July 20, 1987 in addition to the first and second ones. Histological study on every operation indicated malignant meningioma with mitosis, hypercellularity and necrosis. Though radiotherapy (56 Gy whole brain irradiation) was conducted after the sixth operation, multiple tumors recurred and clinical symptoms and signs deteriorated gradually and he finally died September 9, 1989. In malignant meningioma such as our case, early aggressive radiotherapy and chemotherapy should be considered besides radical operations.

Adult↗
PubMed1991

[A case of pregnancy-induced lymphocytic adenohypophysitis complicated by postpartum painless thyroiditis].

We report a patient with pregnancy-induced lymphocytic adenohypophysitis complicated by postpartum painless thyroiditis. A 27-year-old female noticed visual field defect in the 36th week of pregnancy. After delivery in the 39th week by cesarean section, she was admitted for close examination. Goiter was not palpable, and postpartum galactorrhea was not observed. Routine examination revealed no abnormal findings. On October 8, 1989, magnetic resonance imaging (MRI) revealed a tumor image (height 22.4mm) from the sella turcia to suprasellar cistern with a lower signal intensity than that of the white matter on T1 weighted images and a high signal intensity on T2 weighted images. Gd-DTPA contrast images showed a symmetrical and homogeneous tumor image at the same site. However, the posterior lobe of the pituitary gland appeared normal. These findings suggested lymphocytic adenohypophysitis. The LH was less than 0.3mIU/ml. The FSH (7.8mIU/ml), PRL (12ng/ml), GH (1.6ng/ml) and cortisol (10 micrograms/dl) levels were normal. T4 was 5.3 micrograms/dl, T3 67ng/dl, fT4 0.53ng/dl, which indicated mild hypothyroidism, but the TSH was normal. TRH test showed a slight increase in TSH and no response of PRL. Insulin tolerance test showed delayed response of GH and normal response of cortisol. LHRH test revealed no response of LH and delayed response of FSH. Anti-GH3 cell antibody and anti-thyroglobulin antibody were positive, but the anti-AtT20 cell antibody was negative. Since visual disturbance improved, and slight reduction in the mass (height 20.1mm) was confirmed by MRI after delivery on October 21, her course was observed without treatment. After 1 month, the LH became detectable, but the PRL and cortisol decreased to 2.5ng/ml and 6.0 micrograms/dl, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Study on cases with posterior fossa epidural hematoma--clinical features and indications for operation.

In this retrospective study, 11 cases of posterior fossa epidural hematoma were analyzed in terms of clinical and radiological features, treatment, and outcome. Posterior fossa epidural hematomas accounted for 11.8% of all epidural hematomas encountered during the 7-year period studied. There were eight males and three females ranging in age from 2 to 53 years (mean, 20.7 years). Glasgow Coma Scale scores on admission were relatively good in many cases. Headache and/or vomiting were common symptoms on admission, whereas cerebellar signs were rare. As all 11 cases involved trauma, occipital fractures were present in eight (72.7%). Six patients underwent surgery. The indications for surgery, in terms of computed tomography findings, were: 1) the maximum thickness of the epidural hematoma was more than 15 mm; 2) the posterior fossa cisterns (e.g., the quadrigeminal and ambient cisterns) were poorly visualized; 3) there was marked deformity and/or displacement of the fourth ventricle; and 4) the hematoma extended to the supratentorial region and severely compressed the brain. At discharge, eight patients showed good recovery and one was moderately disabled. Two patients died. The prognosis for posterior fossa epidural hematoma appears relatively good, if it is not accompanied by severe primary brainstem injury and is diagnosed early, and appropriately and promptly treated.

Adolescent↗
PubMed1990

[Three cases of carotid anterior cerebral anastomosis].

Three cases are presented with rare carotid-anterior cerebral anastomosis (anomalous ACA) originating from the internal carotid artery at the level of the origin of the ophthalmic artery, running first underneath and then between both optic nerves, and finally joining the anterior communicating artery. Case 1 (47 year-old woman) and case 2 (56 year-old man) were both admitted with subarachnoid hemorrhage from a ruptured aneurysm, which was located at the anomalous ACA (carotid-ACA anastomosis). Case (61 year-old man) was diagnosed as having left occipital intracerebral hematoma on CT, and bilateral anomalous ACA was found on angiograms. This anomalous ACA is very rare; only 21 cases have been reported in the literature. Several synonyms have been proposed as follows: 1) interoptic course of the anterior cerebral artery (ACA), 2) interoptic course of ACA, 3) an anomalous branch of the internal carotid artery (ICA) and 4) an anastomosis between the ICA and the ACA (carotid-ACA anastomosis). In cases with this carotid-ACA anastomosis, coexisting intracranial aneurysm has been reported. However, this is the first report of ruptured aneurysm located at the anomalous ACA itself. Case 1 and 2 were operated on through the ipsilateral pterional approach and the aneurysm was successfully clipped. Postoperative course was uneventful in each case. Case 3 was treated conservatively. From the angiographical and operative findings, we prefer to use "carotid-anterior cerebral artery anastomosis" as the medical terminology best suited to describe this condition.

Carotid Artery, Internal↗
PubMed1989

Epidermoid tumor presenting with trigeminal neuralgia and ipsilateral hemifacial spasm: a case report.

A case of epidermoid tumor presenting with a painful tic convulsif was reported. A 35-year old male with trigeminal neuralgia and ipsilateral hemifacial spasm was diagnosed as having an epidermoid by CT and metrizamide CT cisternography and the symptoms were completely eliminated after the operation. In this case, metrizamide CT cisternography was very useful for preoperative diagnosis by demonstrating the characteristic findings of the epidermoid. It should be taken into consideration that there are some cases with trigeminal neuralgia and/or hemifacial spasm whose symptoms are due to brain tumors.

Adult↗
PubMed1989

[Brain tumors associated with hemorrhage from tumors as their first manifestation].

Four cases of brain tumors associated with hemorrhage from tumors as their first manifestation were reported. These were malignant astrocytoma in two cases, brain metastasis of hepatocellular carcinoma in one case and skull metastasis of hepatocellular carcinoma in one case. Clinical symptoms and sings were generalized convulsion, sudden onset of headache, vomiting and hemiparesis. It was difficult to confirm the diagnosis of brain tumors in such cases. Therefore it is important to perform follow-up plain and enhanced CT repeatedly and it is also important to make adequate biopsy of hematoma wall and surrounding tissue during operation.

Adult↗
PubMed1989

Monostotic fibrous dysplasia of the left parietal bone--case report.

A 14-year-old female presented with a hard, painless mass, 5 x 5 cm, in the left parietal region. Skull x-rays showed a radiolucent skull tumor with a sclerotic margin in the parietal region. Computed tomography revealed an intradiploic multilocular mass separated by bony trabeculae. The outer table had thinned and protruded outward. The inner table was also thin and protruded inward slightly. External carotid angiography revealed a faint tumor stain and feeding from the middle meningeal artery. Bone scintigraphy revealed abnormal uptake in the lesion. Total removal of the skull tumor and cranioplasty were performed. The histological diagnosis was fibrous dysplasia. Fibrous dysplasia within the cranial vault is often expressed as painless bulging without neurological symptoms. Surgery is recommended when neurological symptoms and/or cosmetic problems are present. Histological confirmation of the diagnosis is also important.

Adolescent↗