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Biomedical subjects

H Oka

Publications and source records attributed to H Oka.

At least 253 records · Page 14Linked to original sources

[A case of dural sarcoidosis].

A 26 year-old man, who was treated for meningitis in our hospital previously, was rehospitalized 1 year later because he developed disturbance of consciousness, gait disturbance and urinary incontinence. Blood examination revealed accelerated ESR, elevated GPT, slight elevation of serum Ca, strong positive CRP, and a decrease in PHA and Con A. ACE was within normal range and tuberculin reaction was negative. Lumbar puncture revealed that the initial pressure was 310 mmH2O, cells were 152/3, and protein was 343 mg/dl. Bilateral hilar lymphadenopathy was absent in chest X ray film. Head CT revealed enlarged lateral ventricles and irregularly enhancing nodular lesions in the anterior half of the falx cerebri, and abnormally strong enhancement of the choroid plexus. Ventriculoperitoneal shunt was performed. As a diagnosis was difficult to obtain from the clinical data, biopsy of the nodular lesions was performed. The histopathologic diagnosis was sarcoidosis. Steroid hormone was administered thereafter, and the nodular lesions of the falx disappeared in the follow-up. In the literature, only 8 cases of sarcoidosis of the dura mater have been reported. Since intracranial sarcoidosis is a part of systemic sarcoidosis, its diagnosis is not difficult in most cases. However, in cases difficult to diagnose as in our case, biopsy may be necessary. When nodular lesion occurs in the dura mater, sarcoidosis must be included as a possibility in the differential diagnosis in addition to the usual meningioma, lymphoma, and metastatic brain tumor.

Adult↗

Direct interfacing of high-speed countercurrent chromatography to frit electron ionization, chemical ionization, and fast atom bombardment mass spectrometry.

Direct interfacing of analytical high-speed countercurrent chromatography (HSCCC) to mass spectrometry (MS) was demonstrated for the first time, and its performance was evaluated in terms of chromatography and mass spectrometry. HSCCC/MS interface was based upon Frit electron ionization (EI), chemical ionization (CI), and fast atom bombardment (FAB). Separations were conducted by newly developed HSCCC-4000 with a 2.5-cm revolutional radius and 0.3 mm or 0.55 mm i.d. multilayer coiled column which is capable of operating at a maximum speed of 4000 rpm. To demonstrate the potential capability of HSCCC/frit MS, three indole auxin mixtures, two mycinamicin (macrolide antibiotics) mixtures, and a colistin complex (peptide antibiotics) were analyzed under HSCCC/frit EI, CI, and FABMS conditions, respectively. The data obtained indicated that interfacing to frit/MS does not adversely affect the chromatographic resolution and mass spectra provide structural information. The HSCCC system interfaced with a frit-equipped mass spectrometer will offer a new dimension in the separation of biologically important substances.

Chromatography↗

H(+)-ATP synthase from rat liver mitochondria. A simple, rapid purification method of the functional complex and its characterization.

A novel, simple, and rapid preparative method for purification of rat liver H(+)-ATP synthase by anion-exchange HPLC was developed. The H(+)-ATP synthase purified had higher ATPase activity in the absence of added phospholipids than any preparation reported previously, and this activity was completely inhibited by oligomycin. When reconstituted into proteoliposomes, the H(+)-ATP synthase showed an ATP-dependent 8-anilinonaphthalene-1-sulfonate response and ATP-Pi exchange activity, both of which were also completely inhibited by oligomycin and an uncoupler, indicating the intactness of the H(+)-ATP synthase. An immunochemical study and a labeling experiment with N,N'-[14C]dicyclohexylcarbodiimide ([14C]DCCD) demonstrated the presence of chargerin II ( a product of mitochondrial A6L DNA) and DCCD-binding protein (subunit c) in the complex. The subunits of the complex were separated into 11 main fractions by reverse-phase HPLC, and 3 of them and the delta subunit in F1 were partially sequenced. A search for sequence homologies indicated that these components were subunit b, coupling factor 6, subunit delta, and subunit epsilon. This is the first report of the existence of subunit b, factor 6, and chargerin II in H(+)-ATP synthase purified from rat liver mitochondria.

Affinity Labels↗

Improvement of chemical analysis of antibiotics. XVII. Application of an amino cartridge to the determination of residual sulphonamide antibacterials in meat, fish and egg.

A simple, rapid and reliable method for the determination of residual sulphonamide antibacterials (SAs) (sulphathiazole, sulphisozole, sulphamethoxazole, sulphadiazine, sulphamerazine, sulphadimidine, sulphamonomethoxine, sulphadimethoxine, sulphamethoxypyridazine and sulphaquinoxaline) in meat, fish and egg was developed using a combination of high-performance liquid chromatography (HPLC) and clean-up with an amino-type prepacked cartridge. SAs were extracted with ethyl acetate and applied to a Baker 10 amino cartridge. After elution from the cartridge, SAs were determined by HPLC. The recoveries at the level of 0.5 ppm were 73.7-99.1% and the detection limits were 0.05 ppm. The analysis time per sample was about 45 min.

Anti-Bacterial Agents↗

Systematic search for suitable two-phase solvent systems for high-speed counter-current chromatography.

We have introduced two series of two-phase solvent systems which facilitate the systematic search for the solvent systems suitable for high-speed counter-current chromatography. The n-hexane-ethyl acetate-n-butanol-methanol-water systems provide a broad range of hydrophobicity, while the chloroform-methanol-water systems are extremely useful for separations of various natural products with moderate hydrophobicity. The practical use of these solvent series was demonstrated with several test samples which include dinitrophenyl amino acids, S-triazine herbicides, indole auxins, and non-ionic organic solvents.

1-Butanol↗

Purification of Food Color Red No. 106 (acid red) using high-speed counter-current chromatography.

High-speed counter-current chromatography (HSCCC) has been successfully applied to the separation of the components of Food Color Red No. 106 (R-106). The separation was performed using 25 mg of the sample with a two-phase solvent system composed of n-butanol and 0.01 M trifluoroacetic acid (1:1, v/v). Analyses by thin-layer chromatography, high-performance liquid chromatography and fast atom bombardment mass spectrometry confirmed that HSCCC was effective in the purification of the components of R-106. The separation gave 21 mg of a 99.9% pure main component (Acid Red) and 0.9 mg of 98.0% pure subsidiary dye which is probably a des-ethyl derivative.

Azo Compounds↗

Isolation of bacitracins A and F by high-speed counter-current chromatography.

The major components of bacitracin were separated and purified using high-speed counter-current chromatography (HSCCC). A systematic search for optimum two-phase solvent systems resulted in two systems: chloroform-ethanol-methanol-water (5:3:3:4) and chloroform-ethanol-water (5:4:3). These were selected based on the determination of the partition coefficients of all the components and the settling time of the phases. HSCCC with these solvent systems separated two components, bacitracins A and F. Improvements in the flow-cell arrangement eliminated noise in detection, making in-line monitoring possible. A tandem mass spectrometric technique was used to characterize the isolated components.

Bacitracin↗

Foam counter-current chromatography of bacitracin. II. Continuous removal and concentration of hydrophobic components with nitrogen gas and distilled water free of surfactants or other additives.

Foam counter-current chromatography has been successfully applied to continuous removal and concentration of hydrophobic bacitracin (BC) components from a large volume solution using nitrogen gas and distilled water free of surfactants or other additives. The experiment was initiated by introducing nitrogen at the head inlet of the coil rotated at 500 rpm. Then, a 2.5-1 volume of the sample solution containing BC at 50 ppm was continuously introduced into the middle portion of the coil at 1.5 ml/min. The hydrophobic components produced a thick foam which was carried with the gas phase and collected from the tail end of the coil while other components stayed in the liquid stream and eluted from the head outlet of the coil. High-performance liquid chromatographic analysis of the foam fraction revealed that the degree of enrichment increased with hydrophobicity of the BC components. BC-A and -F were enriched 1400 and 2260 times, respectively, compared with the original concentration in the sample solution. These results clearly indicate that the present method will be quite effective for detection and/or isolation of a small amount of natural products present in a large volume of aqueous solution.

Bacitracin↗

Intracellular recordings from rat thalamic VL neurons: a study combined with intracellular staining.

Intracellular recordings from thalamic neurons receiving cerebellar inputs were performed under urethane anesthesia in the rat. A total of 64 neurons were recorded intracellularly with micropipettes filled with 4% biocytin solution (dissolved in 0.5 M K-acetate), and cerebellar-induced EPSPs (CN-EPSPs), the membrane resistance and firing properties were analyzed with intracellular current injections. The mean latency of CN-EPSPs was 1.9 +/- 0.8 ms and the mean input resistance measured in 10 neurons was 17.6 +/- 5.0 M omega. Thirty-two out of 35 stained neurons were analysed morphologically; 28 of these neurons were located in the VL, and 26 received CN-EPSPs. Their somata were round or polygonal in shape and the mean size was 22.5 x 15.2 microns. They had radially extending spinous dendrites, and the mean radii of the dendritic fields were 214.7 microns in the frontal and 171.4 microns in the sagittal planes. These morphological features were similar to those observed in the sensory relay nucleus of the thalamus.

Animals↗

A new method of hernioplasty for adult groin hernias centering on repair of the transversalis fascia.

A new method of hernioplasty for adult groin hernias centering on repair of the transversalis fascia was assessed by a questionnaire conducted every five years on adult patients who had received the above operation. The efficacy of this method was evaluated in terms of the postoperative quality of life and prevention of recurrence of groin hernias. Over the last 9 years, 834 adult patients with 921 groin hernias, including bilateral lesions, have undergone the above procedure and overall, favorable results were obtained, with only one case of recurrence (0.1 per cent) being reported. Contralateral herniation, which has been often reported following Bassini's or Hatakoshi's method, was found in only one of our patients although the number of patients who complained of pain in the operated region was comparatively high, being 51 cases or 11.4 per cent.

Adult↗

Hemorrhagic venous infarction after excision of an arteriovenous malformation: case report.

A case of arteriovenous malformation (AVM) in which postoperative hemorrhagic infarction developed, probably because of occlusion of the former draining veins, is reported. The hemorrhage developed in the temporal lobe 3 days after the initial operation and was located in the immediate vicinity of the site of the AVM. The following findings suggest that the postsurgical hemorrhage probably resulted from a venous thrombosis: 1) no evidence of residual AVM; 2) delayed onset of the hemorrhage, inconsistent with the time course of a hemorrhage developing according to the breakthrough theory or with insufficient hemostasis with a high-pressure afterload; 3) good correlation between the location of the hemorrhage and the occlusion of the draining veins; and 4) multifocal hemorrhage affecting both the gray matter and the subcortical white matter. Postoperative hemorrhagic infarction caused by thrombosis in the draining veins is rare, but it should be considered as a distinct postoperative complication after removal of an AVM.

Cerebral Hemorrhage↗

Halothane increases epinephrine threshold for the development of slow responses in isolated canine trabeculae.

We studied halothane/epinephrine interaction in isolated canine trabeculae using the doses of epinephrine necessary to produce slow responses (epinephrine threshold for the development of slow responses, ETSR) as an indicator. The preparations were depolarized in Tyrode's solution containing 26 mmol/L of KCl, then epinephrine concentrations in the solution were increased in a stepwise manner. Halothane (1%) had no significant effect, whereas 2% and 4% halothane significantly increased the ETSR. alpha 1-Blockade with either 4, 8, or 16 ng/mL of prazosin or 20, 40, or 80 ng/mL of droperidol did not alter the ETSR, whereas beta 1-adrenergic blockade with 8, 17, or 34 ng/mL of metoprolol significantly increased the ETSR. The same trend was observed when either 8 ng/mL of prazosin or 17 ng/mL of metoprolol was given in combination with 2% halothane. Verapamil (5, 10, or 20 ng/mL) increased the ETSR in a dose-dependent manner. These results indicate that halothane decreases rather than increases the sensitivity of slow calcium channels to epinephrine and that any increase above the baseline ETSR after halothane administration cannot be ascribed to halothane/adrenoceptor interaction but rather to calcium entry-blocking effects of halothane. As slow responses are induced by the activation of slow calcium channels, our findings are consistent with known data that halothane can interfere with slow calcium channel conductance.

Animals↗

[Aging and exocrine pancreatic function evaluated by the recently standardized secretin test].

The authors studied the relationship between aging and exocrine pancreatic function by the secretin test which was recently standardized by the Japanese Society of Gastroenterology. Pancreatic juice was collected at 10 min intervals for 60 minutes after a bolus intravenous injection of secretin (Secrepan, Eisai Co., Ltd., 100 U/body) through a quadruple-lumen doudenal tube equipped with double balloons. Exocrine pancreatic function was evaluated by three parameters: secretory volume, maximal bicarbonate concentration or bicarbonate output, and enzyme (amylase and lipase) output. Control subjects consisted of 65 outpatients presenting with mild vague abdominal symptoms who fulfilled the following three criteria: 1) good general condition with no known diseases; 2) no abnormality in the liver, bile duct, pancreas, kidney and metabolism judged from blood chemistry, urine and stool analysis, upper GI series, abdominal ultrasonography (US), and endoscopic retrograde cholangiopancreatography (ERCP); 3) alcohol consumption less than 25 g/day. Control subjects were divided into three groups: 15 subjects below 40 years of age (group A), 32 subjects from 40 to 65 years (group B), and 18 subjects of 65 years and above (group C). Nineteen patient with chronic pancreatitis were also studied. The group C showed significantly lower values in secretory volume, bicarbonate output, and enzyme output than group A and B. Enzyme output showed a gradual decrease with aging. However, secretory volume and bicarbonate output showed a gentle convex curve with a peak around age 40 and a rather steep down-slope after late 50s. The degree of the decrease was significantly more marked in volume and bicarbonate output than in enzyme output in group C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

A new topoisomerase-II inhibitor, BE-10988, produced by a streptomycete. I. Taxonomy, fermentation, isolation and characterization.

A new topoisomerase inhibitor, BE-10988, was isolated from the culture broth of a strain of actinomycetes. The producing strain had a close resemblance to Streptomyces fimicarius and Streptomyces xanthocidicus. The active principle was extracted from the whole broth of strain BA10988 with ethyl acetate and purified by silica gel chromatography and by HPLC. BE-10988 increased DNA-topoisomerase complex formation and inhibited the growth of both doxorubicin-resistant and vincristine-resistant P388 murine leukemia cell lines, as well as sensitive P388 cell lines.

Animals↗

Expression of immunoreactive E-cadherin adhesion molecules in human cancers.

E-cadherin (E-CD), a Ca(2+)-dependent adhesion molecule, plays a major role in the maintenance of intercellular junctions in normal epithelial cells in most organs. The expression of E-CD in human carcinoma samples (esophagus, stomach, and breast) was investigated using immunohistochemical staining, which was performed on surgical specimens using a monoclonal antibody for human E-CD. E-cadherin was strongly expressed in all normal epithelium examined. However E-CD expression in primary tumors of esophagus (11 of 15: 73%), stomach (5 of 20: 25%), and breast (9 of 20: 45%) was reduced, and 68% of these (esophagus: 8 of 11, stomach: 4 of 5, breast: 5 of 9) displayed heterogeneous E-CD expression. In some tumor cells with reduced E-CD expression, E-CD molecules were located in the cell cytoplasm. These results indicate that there are human cancer cells in which E-CD-related intercellular adhesion is impaired.

Adenocarcinoma↗

[A resected case of renal cell carcinoma with metastasis to pancreas].

We report a case of renal cell carcinoma with metastasis to the pancreas, treated by radical nephrectomy and total pancreatectomy. A 56-year-old man visited our hospital because of macrohematuria and right low backache. An intravenous pyelography, ultrasonography and a CT scan of the abdomen revealed right renal tumor at the upper portion, about 11 cm in diameter, but no abnormal findings of the pancreas. Aortic and celiac angiograms demonstrated multifocal lesions, 1 or 2 cm in size, compatible with a metastatic tumor in the region of the pancreas. The patient underwent right radical nephrectomy and open biopsy of the pancreas. The right renal tumor was histologically revealed to be renal cell carcinoma without nodal or venous extension. Histological examination of the pancreas biopsy specimen confirmed it to be a renal cell carcinoma metastatic to the pancreas. Therefore, he underwent total pancreatectomy 1 month after the previous surgery. Three months after the second surgery, a CT scan of the brain revealed metastasis to the pituitary gland. He is still under therapy.

Carcinoma, Renal Cell↗

[Temporal profile of the superoxide dismutase and the ascorbic acid in focal cerebral ischemia].

It has been proposed that free radical reactions are involved in ischemic brain damage. Since irreversible pathological changes occurs very early phase of the focal ischemia and the ischemic brain edema reaches its peak at about 2 days of ischemia, the free radical reactions must take place before these changes. Superoxide dismutase is a famous enzyme that dismutase superoxide anion, which is believed to be one of the initiator of the free radical reactions. If superoxide anion plays a pivotal role in the genesis of pathological ischemic brain damage and edema, the activity of the enzyme may decrease in the early phase of ischemia. Ascorbic acid is also known to be a scavenger of superoxide anion, and brain tissue contains it in a high concentration. We investigated the changes in superoxide dismutase activity and concentration of reduced ascorbate in focal ischemia. Focal ischemia was produced in rats by permanent occlusion of the left middle cerebral artery. The animals were decapitated 30 minutes, 4, 24, and 48 hours after the operation. Middle cerebral artery territory of each cerebral hemisphere was homogenized and centrifuged with phosphate buffer. The supernatant was divided into two aliquots; one was dialyzed to remove ascorbate and the other was not. The SOD activity was measured by electron-spin-resonance (ESR) spin trapping method, and the ascorbic acid concentration was measured by high performance liquid chromatography with electrochemical detection (HPLC-ECD). Protein concentration was measured by Lowry's method. The enzyme activity was expressed as unit/mg protein, and the ascorbic acid concentration was expressed as microgram/g tissue. The SOD activity decreased markedly by dialysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗