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H Oka

Publications and source records attributed to H Oka.

At least 289 records · Page 16Linked to original sources
PubMed1990

Cortical laminar distribution of rat thalamic ventrolateral fibers demonstrated by the PHA-L anterograde labeling method.

The cortical innervation pattern of rat thalamic ventrolateral (VL) fibers was investigated with the Phaseolus vulgaris-leukoagglutinin (PHA-L) anterograde labeling method. The PHA-L-labeled terminals were distributed in the sensorimotor cortex where the cerebello-cerebral (C-C) evoked responses were recognized. The labeled terminals were detected in all layers except layer VI. In the upper part of layer I, the most densely packed terminals were formed and moderately labeled terminals were seen in layers IV and V. Such a laminar distribution of PHA-L-labeled VL terminals is consistent with the profiles of the C-C responses according to laminar field potential analysis.

Animals↗
PubMed1990

Characterization of nascent lipoproteins produced by perfused rat liver: evidence of hepatic secretion and post-secretory modification of nascent lipoproteins.

We characterized the lipoproteins produced by perfused rat liver in recirculating and non-recirculating systems. The apolipoprotein (apo) B of the perfusate very low density lipoprotein (VLDL) and low density lipoprotein (LDL) were labeled with a radioactive precursor amino acid in both systems, suggesting that newly synthesized apo B was secreted in association with VLDL and LDL. When the lipoproteins obtained from the non-recirculating perfusate were injected into rats in vivo, the half life of the VLDL was 13 min and most of it was converted to LDL, while that of the LDL was 5.2 h, indicating that the perfusate LDL was different from the VLDL with respect to its metabolic fate. These observations suggest that both VLDL and LDL are produced as independent primary products in the liver, although the majority of LDL is derived from VLDL in vivo. The nascent lipoproteins in the non-recirculating perfusate were richer in apo E than those in the recirculating perfusate, and a part of the apo E disappeared when the VLDL was added to the recirculating perfusate. The particle sizes of the VLDL and LDL were examined by electron microscopy, which revealed that those in the non-recirculating perfusate were more homogeneous and smaller than the plasma counterparts, while those in the recirculating perfusate were more heterogeneous and their mean diameter was closer to that of the plasma lipoproteins, than in the case of non-recirculating perfusate. These observations suggest that apo E secreted with the nascent lipoproteins may be picked up by the liver just after secretion, causing the heterogeneity in size, as observed in the case of plasma lipoproteins.

Animals↗
PubMed1990

Production of angiotensin-converting enzyme inhibitors from baker's yeast glyceraldehyde-3-phosphate dehydrogenase.

Angiotensin-converting enzyme (ACE) inhibitors were excised from the molecule of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) preparation of baker's yeast by heating at 120 degrees C in 1 M AcOH-20 mM HCl. Three inhibitors were then purified by gel-permeation and reverse-phase chromatographies. One of the yeast ACE inhibitors, YG-3, was GAPDH peptide 79-89 (Pro-Ala-Asn-Leu-Pro-Trp-Gly-Ser-Ser-Asn-Val, IC50:18 microM), and contained the sequence homologous to vertebrate ACE inhibitors (GAPDH peptides 79-86 or 81-88). Other inhibitors, YG-1 (Gly-His-Lys-Ile-Ala-Thr-Phe-Gln-Glu-Arg, IC50: 0.4 microM) and YG-2 (Gly-Lys-Lys-Ile-Ala-Thr-Tyr-Gln-Glu-Arg, IC50: 2 microM), corresponded to amino acid residues 68-77 in two different forms of yeast GAPDH, respectively. Their sequences were quite different from those of the venom peptide family. YG-1 was the most potent ACE inhibitor among yeast and vertebrate GAPDH peptides excised by acid-limited proteolysis. Thus, yeast GAPDH seems to be an excellent source of naturally occurring ACE inhibitors.

Amino Acid Sequence↗
PubMed1990

Intracranial and intraspinal dissemination from pineal yolk sac tumor treated by PVB therapy--case report.

A 15-year-old male was admitted because of diplopia and persistent headache. Postcontrast computed tomography (CT) revealed a homogeneously enhanced large mass, 3 x 4 cm in size, in the pineal region and moderate obstructive hydrocephalus. A right ventriculoperitoneal shunt was installed. At that time, the serum alpha-fetoprotein (AFP) level increased to 23,036 ng/ml, but the level of serum beta-subunit of human chorionic gonadotropin was less than 0.2 ng/ml. These data indicated the tumor to be a pure yolk sac tumor. Following cisplatin-vinblastine-bleomycin (PVB) therapy and whole-brain irradiation (50 Gy), the tumor disappeared on CT, although the AFP level did not return to normal. Eight months after the completion of initial therapy, he had lumbago. Spinal magnetic resonance imaging revealed a metastatic mass at the L5-S2 levels, which was subtotally removed and histologically diagnosed as yolk sac tumor. Postoperative local irradiation (30 Gy) was performed. Seven months after the operation, spinal dissemination at the Th7 level occurred and, 1 month later, intracranial dissemination in the left cerebellopontine angle was detected. He died 25 months after the first admission. PVB therapy did not prevent spinal dissemination in this case.

Adolescent↗
PubMed1990

Bacillus stearothermophilus glyceraldehyde-3-phosphate dehydrogenase as a source of angiotensin-converting enzyme inhibitors.

The more potent inhibitory activity against angiotensin-converting enzyme (ACE) was excised from a glyceraldehyde-3-phosphate dehydrogenase (GAPDH) preparation of Bacillus stearothermophilus by heating at 120 degrees C in 1 M AcOH-20 mM HCl, as compared with GAPDH preparations of yeast and pig. Sufficient excision of B. stearothermophilus ACE inhibitors required a longer proteolysis time of 60 min. Two inhibitors were then purified by gel-permeation and reverse-phase chromatographies. One of the B. stearothermophilus ACE inhibitors BG-1, was the GAPDH peptide 68-77 (Gly-Lys-Glu-Ile-Ile-Val-Lys-Ala-Glu-Arg, IC50: 32 microM). Another inhibitor, BG-2 (Gly-Lys-Met-Val-Lys-Val-Val-Ser-Trp-Tyr, IC50: 6 microM), correspond to GAPDH peptide 304-313. These sequences were quite different from those of vertebrate GAPDH peptides and the venom peptide family with ACE inhibitory activity. BG-2 was found to be a non-competitive type inhibitor, differing from many natural peptide inhibitors. Thus, B. stearothermophilus GAPDH seemed to be a good source of new type ACE inhibitors, in addition to the advantages due to its thermophilic property.

Amino Acid Sequence↗
PubMed1990

[Evaluation of plasma tissue plasminogen activator (I-PA) levels in patients with liver diseases].

Previous studies have demonstrated that plasma tissue plasminogen activator (t-PA) level was elevated in patients with liver disease. In this study, t-PA antigen levels were investigated in patients with acute hepatitis (AH; N = 12), chronic hepatitis (CH; N = 8), compensated liver cirrhosis (CLC; N = 40), decompensated liver cirrhosis (DLC; N = 23) and hepatocellular carcinoma (HCC; N = 35). The increased t-PA levels (higher than 14 ng/ml) were found in 33% (4/12) of AH on the early hospital days, 25% (2/8) of CH, 45% (18/40) of CLC and 91% (21/23) of DLC, and 60% (21/35) of Hcc cases. In patient with LC, the correlations between t-PA levels and serum total bilirubin (T.Bill) and hepatic synthetic functions were investigated. The results were that the t-PA levels correlated positively with T. Bil and negatively with liver synthetic functions such as albumin, protein C and choline-esterase, indicating that t-PA increased almost in proportion to the deterioration of hepatic function. Serial determination of t-PA in patients with HCC treated by transcatheter arterial embolization (TAE) revealed that TAE failed to normalize the t-PA levels. In one case of HCC complicated with disseminated intravascular coagulation (DIC), t-PA showed a marked increase at acute phase of DIC and subsequent decrease after the successful treatment for DIC by gabexate mesilate (FOY) infusion. These results suggest that increased t-PA in liver disease is due mainly to deterioration of hepatic function, and that secondary fibrinolytic state, such as DIC, is also a contributing factor.

Adult↗
PubMed1990

Automatic diagnosis system of tooth mobility for clinical use.

The examination of tooth mobility gives valuable clinical findings on pathological change in the periodontium. An automatic diagnosis system has been developed for the quantitative evaluation of tooth mobility. Tooth mobility was determined from the vibration characteristics of the periodontium and expressed in terms of such objective biomechanical parameters as stiffness and two damping coefficients. These were displayed on a monitor CRT as a triangular figure. This system is composed of a probe, which comprises a vibrator and acceleration transducers, and a data analysis unit using a personal computer. A dentist can measure the tooth mobility without assistance with a foot-switch to trigger the computer operation. The reliability and the operational facility of the system are considered to be sufficient that it may be used in daily clinical practice. Data were collected from healthy and pathological teeth. The tooth mobility of the pathological tooth and the time course of the change in the mechanical parameters after implantation of the tooth were measured by this system. The advantages of this system compared with previous one, which was also developed by the authors, are discussed.

Adult↗
PubMed1990

[An autopsy case of primary intracranial squamous cell carcinoma].

An autopsied case of primary intracranial squamous cell carcinoma (PISCC) is reported, and 25 previously reported cases of PISCC, followed by the Garcia's criteria, are reviewed. A 72-year-old female was admitted to our service with chief complaints of headache and nausea on March 30, 1988. She had no neurological deficits on admission. However, CT examination revealed a round mass lesion in the left hypothalamus with dislocation of the brain stem. The cerebrospinal fluid (CSF) examination showed squamous cell carcinoma cytologically, and slightly higher levels of beta-HCG (13.0 ng/ml) and CEA (14.2 ng/ml). Because of progressive worsening in the level of her consciousness, total removal of a suprasellar tumor was performed on April 19, 1988. Gross appearance of the tumor was yellowish, soft and encapsulated. Histologically, it was squamous cell carcinoma. She did well for several days after the operation, then deteriorated. Finally she expired because of dissemination of the carcinoma on May 14, 1988. Postmortem examination revealed a large mass of squamous cell carcinoma in her right cerebellopontine angle. Except for that in the brain, no cancer was found in her body. Immunohistological study of the tumor specimen demonstrated positive for HCG in some of the large-sized neoplastic cells. Twenty-six cases of PISCC have been reported previously, so far. However, 21 cases out of the 26 PISCC were thought to have originated from intracranial epidermoid, one from the dermoid and the other one from craniopharyngioma. In the other three cases of PISCC, including the present case, the origin of the tumor was not able to be identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Unfolded map of coronary artery territories by myocardial SPECT].

Coronary artery territories were evaluated precisely by Bull's-eye and unfolded map generated from myocardial SPECT. In addition, unfolded maps including apical information were also developed. The coronary artery territories were determined by 54 cases of typical single vessel disease (more than 75% stenosis) with myocardial infarction and angina pectoris. There were 12 of right coronary artery disease, 24 of left anterior descending coronary artery disease, 5 of diagonal coronary artery disease, and 13 of left circumflex artery disease. Each diseased region was summed and normalized using the standard pattern (21 cases of normal male and 13 cases of normal female). Apical information was simply obtained using the anterior and posterior count from short and long axial image. Then, their data were added to the unfolded map. In conclusion, unfolded map was proven to be useful for the determination of coronary artery territory, since this map expressed the extent and site of myocardial damage precisely compared to Bull's-eye. The unfolded map to contain the apical information was also useful for the evaluation of left anterior descending coronary artery involvement.

Coronary Disease↗
PubMed1990

[A case of chronic subdural hematoma associated with idiopathic thrombocytopenic purpura (ITP)].

A 41-year-old male was admitted to our service with right occipital pain as his chief complaint. CT and MRI examinations revealed bilateral chronic subdural hematomas. The patient had also been affected with ITP since the age of 28. Since emergency operation was thought to be dangerous, he was transferred to Tokushima University Hospital, and treated preoperatively by administration of steroids and a large dose of immunoglobulin. When his platelet count had returned to 146,000/mm3, evacuation of the hematoma through burr holes was performed successfully under local anesthesia. The postoperative course was uneventful. So far as we have been able to find in the literature, only 3 cases of ITP complicated by chronic subdural hematoma have been reported. The characteristic clinical feature of these 4 cases including our own case was noted as the absence of a history of trauma. However, the etiological relationship between ITP and chronic subdural hematoma was controversial. Occurrence of chronic subdural hematoma in patients with ITP and in patients under hemodialyzer treatment is very rare. However, intracerebral hemorrhages are rather common among such patients. So it was suggested that the tendency to bleeding among patients with ITP, and among hemodialyzer patients may contribute little as an etiological factor in the evolution of chronic subdural hematoma.

Adult↗
PubMed1990

[Serial assessment of denervated but viable myocardium following acute myocardial infarction by using 123I-MIBG and 201TlCl myocardial SPECT].

123I-MIBG is taken up by sympathetic nerve ending and provides a scintigraphic image of myocardial sympathetic innervation. We investigated the scintigraphic detection of denervated but viable myocardium following acute myocardial infarction by serial 123I-MIBG and 201TlCl myocardial SPECT. Fourteen patients were studied at acute (10 +/- 2 days) and chronic stage (86 +/- 10 days). Simultaneous dual SPECT was carried out after IV administration of 111 MBq (3 mCi) of 201TlCl and 123I-MIBG. The defect size of 123I-MIBG and 201TlCl were compared visually by using Bull's eye display generated from each myocardial SPECT. In all patients, 123I-MIBG defect showed larger compared to 201T1Cl defect at acute stage, which suggest the existence of denervated but viable myocardium. Of these patients, seven showed significant improvement of both defects, though 123I-MIBG defect showed slightly larger compared to 201TlCl defect, even at chronic stage. These patients had exercise induced thallium transient defect at infarcted area. The remaining 7 patients had no improvement of both defects at chronic stage, which suggest the complete scar at infarcted area. In addition to above study, 4 patients of old myocardial infarction demonstrated larger 123I-MIBG defect compared to 201TlCl defect even at old stage, which thought to be pathogenesis of ventricular tachycardia. In conclusion, 123I-MIBG could evaluate sympathetic denervation and reinnervation noninvasively in the patients with acute myocardial infarction.

3-Iodobenzylguanidine↗
PubMed1990

[A case of systemic lupus erythematosus showing abnormal lipoproteins due to accompanied drug induced hepatitis].

We describe here a 28-years-male with AIHA and SLE who had lipid and lipoprotein abnormalities during cholestasis induced by PGE1 administration. High free cholesterol level, 792 mg/dl was found in his serum, and markedly elevated, phospholipid level 1,614 mg/dl. But, LCAT activity was within normal range in this case. An agarose gel electrophoresis of lipoproteins showed abnormal bands which were located in slow alpha 2, pre beta and slow beta, and between beta and origin point. Moreover, it was detected formation of Lp-X from serum of the patient. Serum levels of apoprotein B, C-II, C-III, and E were higher, while apoprotein A-I, A-II were very lower than reference value. From these results, it was suspected that the patient might occur transient abnormal lipid metabolism according to the drug induced hepatic injury.

Adult↗
PubMed1990

Heterogeneity in lectin-binding characteristics of human lymphokine-activated killer cells.

The binding of various lectins to human lymphokine-activated killer (LAK) cells was investigated. Human peripheral blood lymphocytes were cultured for 3 days with recombinant interleukin-2 (rIL-2), and then stained with 20 kinds of lectins. There were four types of lectin-binding patterns: (a) negative staining; (b) weakly positive staining; (c) strongly positive staining; and (d) two populations, one weakly and one strongly positive staining. Among the 20 kinds of lectins, both Lens culinaris agglutinin (LCA) and Pisum sativum agglutinin (PSA) showed two peaks in the staining patterns on LAK cells (type 4). We separated these two populations of LAK cells by using a cell sorter, and assayed them for cytotoxic activity against 51Cr-labeled Hela cells. The LAK cells that were strongly stained by LCA or PSA [LCA (or PSA)-bright LAK cells] showed stronger cytotoxic activity than the LAK cells that were weakly stained by LCA or PSA [LCA (or PSA)-dull LAK cells]. Furthermore, we separated lymphocytes with LCA or PSA before culturing them with rIL-2 (LAK precursor), and we found that both LCA-bright and PSA-bright lymphocytes can develop into LAK cells with higher cytolytic activity. LCA-bright lymphocytes kept their ability to be stained strongly with LCA even after culture with rIL-2 for 3 days. Similarly, LCA-dull lymphocytes were still stained weakly after culture with rIL-2. Two-color assay of LAK cells revealed that 78% of NK (CD16+)-LAK cells and 46% of T (CD3+)-LAK cells were LCA-bright cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗