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Biomedical subjects

K Sano

Publications and source records attributed to K Sano.

At least 523 records · Page 29Linked to original sources
PubMed1989

[Changes in xanthine and uric acid in rat brain after middle cerebral artery occlusion].

Xanthine and uric acid, products of purine metabolism, were measured by reversed-phase high-performance liquid chromatography (HPLC) with electrochemical detection in rat forebrain following focal cerebral ischemia. Focal cerebral ischemia was induced in the rat by permanent occlusion of the left middle cerebral artery (MCA). Sprague-Dawley rats were anesthetized with halothane inhalation and left MCA was occluded via trans-retro-orbital approach. Normal and sham-operated rats were used as control animals. The animals were decapitated 2 (MCA = 5, Sham = 5), 4 (MCA = 7, Sham = 6), 8 (MCA = 5, Sham = 5), and 16 (MCA = 6, Sham = 6) hours or 1 (MCA = 5, Sham = 5), 2 (MCA = 6, Sham = 6), 7 (MCA = 7, Sham = 6), 14 (MCA = 6, Sham = 5), and 28 (MCA = 7, Sham = 5) days after the operation. The brains were removed and divided into right and left hemisphere. Each hemisphere was homogenized and centrifuged. The supernates were filtered with membrane filter. An aliquot of the filtrate was used for measurement of xanthine and uric acid in both of the ischemic and contralateral hemisphere by a HPLC system. In the normal group, xanthine and uric acid in the brain was 12.4 +/- 0.4 and 2.2 +/- 0.1 nmol/g tissue (mean +/- SEM), respectively. In the ischemic hemisphere, xanthine increased up to 57.7 +/- 5.2 nmol/g tissue 2 hours after MCA occlusion and reached a maximum value of 59.42 +/- 4.91 nmol/g tissue 4 hours following the induction of ischemia. Xanthine level was still high 8 hours after ischemia and then rapidly decreased to the normal value at day 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Clinico-pathological studies of cytochrome P-450 on human hepatic disorders].

Immunohistochemical examinations were carried out for the study of cytochrome P-450 implication in the human hepatic disorders. An isozyme of human hepatic P-450 (P-450-HM1) with the m.w. of 51,000 was purified from human autopsied liver. Antibody against P-450-HM1 was prepared in rabbits, of which specificity was confirmed by Western blot. Eighty-three livers (27 autopsies and 56 biopsies, M:F = 63:20), which were either normal or of various hepatic disorders such as acute or chronic hepatitis, cirrhosis and hepatocellular carcinomas, were examined by the method of avidin-biotin-complex technique. It was revealed that immunoreactive hepatocytes were diffused throughout the lobule of the fetal liver. In the normal livers as well as those of acute and chronic hepatitis, positive hepatocytes were found in the centrilobular zone. Three of the 4 cases treated with beta-interferon showed faint staining; and the presence of positive individual hepatocytes was considered to be induced by steroid therapy. In the livers with chronic hepatitis and cirrhosis, hepatocytes near the perifibrous region and those trapped in the portal triad by thin fibrous connective tissue, as well as in the regenerating nodules, were strongly stained, which indicate that P-450-HM1 is expressed in the regenerating hepatocytes. Hepatocellular carcinomas, however, were devoid of immunohistochemistry. From these results, the antibody might be a useful tool for differentiating regenerating nodule from hepatocellular carcinoma.

Adult↗
PubMed1989

[A case of acute spinal epidural hematoma in a patient with antiplatelet therapy].

The authors report a case of acute spinal epidural hematoma occurring in a patient receiving antiplatelet drugs. A 76-year-old man with a history of cerebral infarction had been taking antiplatelet agents for one year. He suddenly developed severe back pain which woke him from sleep, and numbness of his lower extremities was then noted. He was hospitalized 15 hours later. Neurological examination revealed flaccid paralysis of both lower extremities with negative Babinski's reflex, and sensory disturbance below the level of L1. The bleeding time and prothrombin time were prolonged. Computed tomographic (CT) scan revealed a biconvex, relatively hyperdense mass in the posterior spinal canal at the level of T12. Metrizamide myelography disclosed an incomplete blockage caused by an epidural mass at the level of T11. Post-myelographic CT scan demonstrated a sharply demarcated extradural filling defect at the level of T11. Seventeen hours after the onset of symptoms, an emergency laminectomy was performed extending from T12 to L3, and the epidural clot was totally evacuated. Histological examination of the capsule of the hematoma revealed no vascular anomalies. The patient made a good postoperative recovery. To the authors' knowledge, this is the first reported case of spontaneous intraspinal hemorrhage in a patient taking antiplatelet drugs. Acute onset of persistent pain anywhere along the spinal axis and the development of spinal neurological deficits in a patient on antiplatelet therapy should raise the suspicion of a spinal epidural hematoma. It should be stressed that prompt neuroradiological diagnosis and rapid surgical decompression are essential to allow good recovery. The present case illustrates that neurological emergencies can occur in patients receiving antiplatelet therapy.

Acute Disease↗
PubMed1988

Rat pulmonary surfactant protein A is expressed as two differently sized mRNA species which arise from differential polyadenylation of one transcript.

In rat, the surfactant-associated glycoprotein A, SP-A, is encoded by two mRNA species of 0.9 and 1.6 kb. Each transcript is polyadenylated and is found in approximately the same ratio in total cellular RNA isolated from either alveolar type II cells or from whole lung. The two mRNA species have identical coding regions and differ only in the length of the 3' untranslated sequences. Restriction analysis and partial sequence analysis of rat genomic clones indicate that each mRNA species arises from one gene, with the difference in size most easily accounted for by differential polyadenylation. During fetal development, the accumulation of mRNA encoding SP-A is detectable by day 18 but increases many-fold on day 19. However, there are no apparent alterations in the prevalence of either mRNA species during fetal development or in the early postnatal period.

Amino Acid Sequence↗
PubMed1988

Behavioral changes after focal cerebral ischemia by left middle cerebral artery occlusion in rats.

Behavioral changes after occlusion of the left middle cerebral artery (MCA) in rats were investigated for 16 weeks. Impairment of motor coordination and incidence of neurological deficits including hemiplegia and abnormal posture were present for the first 2 and 4 weeks after MCA occlusion, respectively. Learning behavior in one-trial passive avoidance task was disturbed for the entire 16-week period when rats were trained at days 3 after MCA occlusion. Reacquisition was also impaired when rats were retrained on 8 weeks after MCA occlusion. Except for synchronized EEG at days 2 after MCA occlusion, significant changes in spontaneous movement and EEG were not observed in the MCA-occluded group. These results suggest that this rat model of MCA-occlusion is useful for quantitatively measuring functional changes in chronic phase of focal cerebral ischemia.

Animals↗
PubMed1988

The Na+/H+ antiporter in rat alveolar type II cells and its role in stimulated surfactant secretion.

We used the pH-sensitive fluorescent probe 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF) to identify Na+/H+ exchange in freshly isolated rat alveolar type II cells and alveolar type II cells in primary culture. The intracellular pH (pHi) of freshly isolated alveolar type II cells was 7.36 +/- 0.05 (n = 3). When freshly isolated alveolar type II cells were acid loaded with nigericin in sodium-free buffer, the pHi dropped to 6.59 +/- 0.04 and remained low in sodium-free buffer. When acid-loaded cells were subsequently incubated with NaCl, pHi increased in a dose-dependent manner. Amiloride (0.1 mM) inhibited the sodium-induced increase in pHi. When the acid-loaded cells were resuspended in an unbuffered choline chloride solution, the cells secreted H+ in a sodium-dependent and amiloride-inhibitable manner. Alveolar type II cell monolayers, which were cultured for 22 h on glass coverslips and then loaded with BCECF, had a resting pHi of 7.48 +/- 0.05 (n = 4). Nigericin acidified these cultured cells in the absence of sodium and NaCl increased the pHi of these acid loaded cells as observed in freshly isolated cells. Secretagogues of pulmonary surfactant, 12-O-tetradecanoylphorbol 13-acetate (TPA) and terbutaline, did not change pHi. Inhibition of the Na+/H+ antiporter by the addition of amiloride to a Na+ containing medium or the substitution of choline for Na+ did not inhibit stimulated phosphatidylcholine secretion. We conclude that pHi regulation in rat alveolar type II cells is in part mediated by an amiloride-sensitive Na+/H+ antiporter, but this system appears not to be involved in TPA- or terbutaline-induced pulmonary surfactant secretion in primary culture.

Amiloride↗
PubMed1988

Glucose metabolism via the Embden-Meyerhof pathway is not involved in ATP production during spore germination of bacillus megaterium QM B1551. A study with a mutant lacking hexokinase.

In order to investigate contributions by glucose metabolism via the Embden-Meyerhof pathway and that via the direct oxidation route to gluconate to initial ATP production during spore germination, respiratory activity and RNA synthesis were compared between the mutant lacking hexokinase and the parent spores of Bacillus megaterium QM B1551. We found that time courses of those metabolic events were almost identical between those spores, thus clearly indicating that NADH formed by a spore-specific enzyme glucose dehydrogenase (EC 1.1.1.47) is solely responsible for aerobic production of ATP at this stage.

Adenosine Triphosphate↗
PubMed1988

Posteromedial hypothalamotomy in the treatment of violent, aggressive behaviour.

Although emotion in the human is largely modified by the frontal association areas (software) and may better be called affect, it is still very much influenced by the balance of the ergotropic and the trophotropic circuits in the prosencephalon (hardware) especially in patients with organic brain lesions. Violent, aggressive, restless behaviours or rage can be regarded as an unbalanced state of these two circuits with dominance of the ergotropic circuit. In order to restore the balance of these two circuits, small stereotactic lesions were made in the ergotropic portion of the posterior hypothalamus (posteromedial hypothalamotomy) with good results in the follow-up of 10-25 years. Postoperatively there was no disturbance in endocrine activities and growth.

Aggression↗
PubMed1988

Buccal hemangioma with phleboliths. Report of two cases.

Two cases of buccal hemangioma with phleboliths were reported. Angiography, angioxerography, and computerized tomography were carried out before the procedures were planned. One patient was treated by means of surgical excision of the tumor after ligation of the left external carotid artery. The second patient was treated by means of surgical excision alone. Histologic examinations suggested that the thrombi in the blood vessels of hemangiomas might become the core of the phleboliths. Analysis of the phleboliths by means of x-ray diffraction and infrared spectrometry confirmed calcium phosphate and calcium carbonate as the main components of the phleboliths.

Adolescent↗
PubMed1988

Primary role of NADH formed by glucose dehydrogenase in ATP provision at the early stage of spore germination in Bacillus megaterium QM B1551.

Metabolic events involved in energy metabolism were studied in order to evaluate the ATP-forming ability of Bacillus megaterium QM B1551 spores at the very early stage of germination. When heat-activated spores were germinated on glucose as a sole substrate, its oxidation into gluconate (catalyzed by glucose dehydrogenase, EC 1.1.1.47), the accompanying NADH formation, oxygen uptake, and RNA synthesis were initiated immediately after germination, even when anaerobic breakdown of 3-phosphoglycerate (an ATP source for spores) and the subsequent glucose metabolism via the phosphorylating pathway were impaired by potassium fluoride (KF). In contrast, fructose metabolism and the accompanying metabolic events did not begin until a few minutes after triggering of germination, and those events were entirely abolished by KF, indicating that fructose metabolism is initiated exclusively via its phosphorylation by the ATP derived from endogenous 3-phosphoglycerate. Thus those results provided further evidence for our previous proposal (Otani et al (1987) Microbiol. Immunol. 31: 967-974; Sano et al (1988) Biochem. Biophys. Res. Commun. 151: 48-52) that the first molecules of ATP in germinating spores can be efficiently generated via aerobic oxidation of NADH, which is formed by glucose dehydrogenase. Fluorescence monitoring of NADH in germinating spores also supported this conclusion.

Adenosine Triphosphate↗
PubMed1988

Experimental amyloidosis induced by saponin.

White male rabbits, weighing about 3 kg, were injected intravenously with 5 ml of 0.1% saponin solution dissolved in physiological saline once a week for six months. The sequential histological changes in the kidneys were observed by repeated biopsies and, in addition, the animals were subjected to necropsy for light and electron microscopic examinations. Amyloid protein was purified from the animal tissues, estimated at approximately 6,300 daltons in molecular weight by SDS-PAGE and considered as an AA type protein based on its amino acid sequence study. The antibody against the purified amyloid protein was produced in guinea pigs and was used for immunohistochemical studies. The deposition of amyloid started initially in mesangial matrices and subendothelial regions of the glomeruli, but at the end the spleen, kidney and bowels were found to be frequent sites of deposition. The amyloid deposited in the tissues was specifically positive by the indirect immunohistochemistry using the prepared antibody. This antibody also reacted positively to human materials with secondary amyloidosis. These results indicate that amyloidosis induced by saponin is a good model of secondary amyloidosis.

Amino Acid Sequence↗
PubMed1988

Xanthine and uric acid levels in rat brain following focal ischemia.

Changes of the xanthine and uric acid (UA) levels in rat forebrain following focal cerebral ischemia were studied by reversed-phase HPLC with electrochemical detection. Focal ischemia was induced by occluding the left middle cerebral artery in the rat. The xanthine level in the normal group was 11.50 nmol/g tissue. In the ischemic group, the xanthine concentration in the ischemic hemisphere progressively increased after occlusion and reached a maximum value of 59.42 nmol/g tissue 4 h after operation. The UA level in the normal group was 2.20 nmol/g tissue, whereas in the ischemic group the UA concentration in the ischemic hemisphere gradually increased after occlusion, reaching a value of 38.53 nmol/g tissue 24 h after ischemia. The concentration of UA remained elevated in the ischemic hemisphere until 48 h after occlusion, and reached a maximum value of 38.98 nmol/g tissue. The xanthine and UA levels in the contralateral hemisphere remained unchanged. The xanthine and UA concentrations in the sham-operated group did not show a significant increase after operation. The time course of xanthine and UA levels suggests that in ischemic forebrain UA is formed from xanthine as a product of purine metabolism.

Animals↗
PubMed1988

Comparable sensitivities for detection of human immunodeficiency virus by sensitive reverse transcriptase and antigen capture enzyme-linked immunosorbent assays.

The sensitive overnight reverse transcriptase and the antigen capture enzyme-linked immunosorbent assays were tested for their ability to detect human immunodeficiency virus. The two assays were able to quantitate as few as 75 to 130 virus particles. Thus, both tests offer similar sensitivities for determining the presence of the virus.

Antibodies, Viral↗
PubMed1988

Impairment of superoxide release by alveolar macrophage in rats exposed to oxygen and vitamin E.

We examined the digitonin-stimulated release of superoxide by alveolar macrophages (AMs) from young rats exposed to greater than 95% oxygen for 24-168 h. AMS were obtained by lung lavages, and the release of superoxide stimulated by digitonin was measured by using cytochrome C reduction. The total cell count of lung lavages decreased at 24 and 168 h of oxygen exposure (p less than 0.05 for both). The contamination of polymorphonuclear cells (PMNs) was less than 1% up to 120 h of oxygen exposure, and at 168 h PMNs increased to 5% of total cells in lung lavages. The viability of AMs was greater than 95% up to 72 h and then decreased to 90% at 120 h of oxygen exposure and 87% at 168 h. Digitonin-stimulated superoxide release by AMs recovered from lung lavages in rats exposed to hyperoxia showed a slight increase during the first 48 h. However, oxygen exposure for 72 h or more caused a significant decrease of the stimulated superoxide release of AMs compared to AMs from control rats. This decline in stimulated superoxide release of AMs resulting from hyperoxia was not prevented by vitamin E treatment.

Animals↗