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Biomedical subjects

H Ono

Publications and source records attributed to H Ono.

At least 469 records · Page 26Linked to original sources
PubMed1989

Study of anionic sites on the mesangium in aminonucleoside nephrosis.

In recent years, various reports have appeared concerning anionic sites in glomerular lesions. However, no detailed results for anionic sites in the mesangium have been reported. The authors therefore prepared nephrotic rats by the administration of puromycin aminonucleoside (PA) and investigated the anionic sites in various mesangial regions, using polyethyleneimine (PEI) as a cationic probe. In the mesangium of the control group as well as the experimental groups, PEI particles were most numerous in the subendothelial regions, followed by the central region and paramesangial region, in that order. In the group treated with PA, the numbers of PEI particles in each mesangial region decreased as compared with those in the control group. Among the three mesangial regions considered, this decrease was most pronounced in the paramesangial region. In the group which received elastase, no significant decrease in numbers of PEI particles was observed in subgroups I and II, indicating maintenance of the anionic sites. The results obtained suggested that regional investigations of the mesangial matrix may be of considerable significance for elucidating the etiologic factors in glomerular sclerosis, and that negative charge impairment in the mesangial matrix plays an important role in the development of glomerular sclerotic lesions.

Animals↗
PubMed1989

[Analysis of pancreatic enzymes in the bile of congenital choledochal cyst with anomalous pancreaticobiliary ductal union].

Pancreatic enzymes in the bile of congenital choledochal cyst with anomalous pancreaticobiliary ductal union were analyzed. Almost all pancreatic proteases were already activated in the bile aspirated immediately after insertion of PTCD tube. However, inactive proteases gradually increased after continuation of drainage by PTCD. Pancreatic protease activities appeared again after clamping the PTCD tube. In vitro study of trypsin activities in the bile containing no initial trypsin activity, active type of trypsin did not appear throughout the experimental period. It is suggested that continuous reflux of pancreatic juice into the bile and certain incubation time are necessary for activation of pancreatic protease in bile of congenital choledochal cyst.

Adult↗
PubMed1989

[A case of huge duodenal leiomyosarcoma].

A case of duodenal leiomyosarcoma with large central necrosis was reported. Tumor was 15 X 10 X 10 cm in size. Ultrasonography showed a cystic tumor with thick wall in the right upper abdomen. CT scan revealed a gas formation in the central cystic cavity of the tumor. The gas formation was probably caused by bacterial infection. The diagnosis was confirmed histologically.

Aged↗
PubMed1989

[Pathomorphological studies on arterial cushion. 1. Rat normal kidney].

The present studies are an attempt to elucidate the vulnerability of focal glomerular sclerosis (FGS). The distribution and morphology of the arterial cushions were studied in rat renal arteries by light microscopy, transmission electron microscopy and scanning electron microscopy (SEM) using of the renal vascular casts. The arterial cushions were observed at a region of the branching arteries from the arcuate arteries and the interlobular arteries. They were extensively demonstrated mainly in the mid cortex and juxtamedullary cortex by the serial sections, but not in the subcapsular cortex. The arterial cushions showed valve-like protrusions and consisted of three components, such as the endothelial cells, the smooth muscular cells and the interstitial ground substances, electron microscopically. The cushions are covered by the endothelial cells which often showed various variation in thickness. Also these had deep processes which elongate into the interior of the cushions. The cells of interior portions of the cushions were modified smooth muscular cells. These cells contained numerous myofibrils and a large number of scattered glycogen granules. No nerve fibers were seen within the cushions. The modified smooth muscular cells were embedded in a loose matrix (probably acid mucopolysaccharides) which contained strands of basement membrane like material. The cushions were observed on the wall of the arcuate and interlobular arteries in the cortex except for subcapsular cortex by SEM. They showed elongated indentation surrounding lumen of their arteries. These results of the observation, the cushion may be important factor for the regulation of blood flow in small arteries and arterioles. The disorder of autoregulation of interlobular arteries due to dysfunction of the cushions with anionic loss were assumed to be one of the important factor in progress to the glomerular sclerosis.

Animals↗
PubMed1989

[A case of schwannoma of intrathoracic right phrenic nerve].

A 22-year old man was admitted because of an abnormal shadow on his chest X-ray film. Radiographic findings revealed that the tumor was located in the right middle mediastinum. At operation a smooth round tumor was found arising from the right phrenic nerve. The tumor was removed with phrenic nerve. Pathohistological examination revealed this tumor was benign schwannoma. Intrathoracic schwannoma usually arise from intercostal and sympathetic nerve and that arising from phrenic nerve is very rare. We removed the tumor by means of cutting his right phrenic nerve because of complete resection. Postoperatively he did well without any respiratory distress. And his respiratory function studies recovered normal 9 months after the operation. We think that schwannoma arising from phrenic nerve should be removed completely and in such a case cutting of the one side phrenic nerve is at ease if the patient have normal respiratory function.

Adult↗
PubMed1988

Glucose inhibits prostacyclin production by cultured aortic endothelial cells.

A reduction in production of prostacyclin (PGI2) by the cells in the vascular wall may play a role in the pathogenesis of atherosclerosis in diabetic patients. The present study was undertaken to evaluate the effect of glucose on PGI2 production by endothelial cells in vitro. It was shown that PGI2 production by cultured bovine aortic endothelial cells was significantly reduced in the presence of a high concentration of glucose (300 mg/dl) compared with physiological concentrations of glucose (100 mg/dl). In contrast, no reduction in PGI2 production was observed in cells cultured with equimolar mannitol, suggesting that glucose itself, rather than the effect of osmolality, inhibited PGI2 production by cultured endothelial cells. In addition, a high concentration of glucose also inhibited the proliferation of cultured endothelial cells.

Animals↗
PubMed1988

Unit activity of ventral horn cells in spinal cord slices isolated from adult rats.

Using spinal cord slices isolated from adult rats, unitary action potentials were recorded extracellularly in the motor nuclei of the ventral horn following local stimulation of the adjacent site. Generation of these spikes was blocked by perfusion with artificial cerebrospinal fluid containing low Ca2+ and high Mg2+ and by increasing the frequency of electrical stimulation. Generation of unitary action potentials was very sensitive to hypoxia or anesthesia. In some cells, burst spikes similar to those of Renshaw cells were also observed. Physostigmine increased the firing rate of spike discharges, whereas mecamylamine decreased it. These results suggest that the former unitary action potentials were evoked transsynaptically in motoneurons by excitation of adjacent afferent fibers and that the latter burst potentials were evoked in Renshaw cells.

Action Potentials↗
PubMed1988

cDNA cloning and sequence analysis of a chicken gene expressed during the gonadal development and homologous to mammalian cytochrome P-450c17.

A cDNA clone, pLOA0511, was isolated from the cDNA library prepared from the left ovaries of one- to three-day-old chickens. The transcript corresponding to this cDNA clone is approx. 1.9 kb in length and is present in steroidogenic tissues (ovary, testis and adrenal gland) but is undetectable in non-steroidogenic tissues. Relative abundance of the transcript in the ovary and testis is high and developmentally regulated but is much lower in the adrenal gland. Relative levels of this transcript in the developing left ovary and the regressing right ovary of the one- to three-day-old chicken are similar. The nucleotide sequence of this cDNA clone shows significant homology to some mammalian cytochromes P-450. Out of the 508 amino acids (aa) coded, 244 and 243 aa residues are identical with those of the bovine and human cytochrome P-450c17 (steroid 17 alpha-hydroxylase/17,20 lyase), respectively. There are three highly conserved regions among the bovine, human and chicken sequences, one of which is unique to P-450c17. These data suggest strongly that this cDNA corresponds to the mRNA of a chicken cytochrome P-450c17.

Amino Acid Sequence↗
PubMed1988

The spinal reflex of chronic spinal rats is supersensitive to 5-HTP but not to TRH or 5-HT agonists.

The effects of thyrotropin-releasing hormone (TRH), 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) and L-5-hydroxytryptophan (5-HTP) were studied on the monosynaptic reflex (MSR) and the polysynaptic reflex (PSR) in acute and chronic spinal rats. Radioimmunoassay showed that while chronic spinal transection (for 2 weeks) caused the complete depletion of TRH in the ventral lumbar enlargement a certain level of TRH was maintained in the dorsal lumbar enlargement. This result suggested the existence of TRH-containing neurons in the dorsal horn other than the medullary raphe neurons descending to the spinal cord. The latency to the start of the MSR was shortened in chronic spinal rats and the amplitudes of the MSR and PSR were significantly greater than those in acute spinal rats. There was no obvious difference in the effects of TRH and 5-MeODMT on spinal reflexes of acute and of chronic spinal rats although marked supersensitivity to 5-HTP was observed in both the MSR and the PSR in chronic spinal rats. The supersensitivity to 5-HTP was considered to be due to a lack of 5-hydroxytryptamine (5-HT) uptake into 5-HT-containing nerve terminals rather than to a change in 5-HT receptors. It is suggested that TRH and 5-HT do not show any mutual requirement for each other in their effects on the spinal reflex since co-depletion of TRH and 5-HT did not change the effects of TRH and 5-MeODMT in chronic spinal rats. The coexistence of 5-HT and TRH in the descending spinal pathway is not considered to be significant for the control of spinal reflexes at the postsynaptic level.

5-Hydroxytryptophan↗
PubMed1988

Sensitive serum markers for detecting pancreatic cancer.

Serum amylase, immunoreactive elastase (IRE), carcinoembryonic antigen (CEA), and carbohydrate antigen (CA 19-9) were measured in 40 patients with pancreatic cancer. IRE and CA 19-9 were further assayed in nonpancreatic malignancies (n = 98) and chronic nonmalignant disease (n = 194). In pancreatic cancer, elevated values were observed for amylase in 30% of the patients, for IRE in 70%, for CEA in 28%, and for CA 19-9 in 68%. Elevation of IRE and/or CA 19-9 was found in 95% of the 40 patients. Elevated serum IRE was observed more frequently in head cancer and resectable cancer, whereas elevation in CA 19-9 occurred more often in body-tail cancer and unresectable cancer. Elevation of serum IRE tends to occur at earlier stages of pancreatic cancer. No one test is adequate for the accurate diagnosis of pancreatic cancer. However, the two assays complement each other, and their combined use would provide a sensitive clue for tentative diagnosis of pancreatic cancer.

Adenocarcinoma↗
PubMed1988

Leukemic involvement of the optic nerve.

We studied five cases of leukemia with invasion of the optic disk and optic nerve. Two patients had acute lymphoblastic leukemia and three had acute myelogenous leukemia. All patients received intrathecal injections of chemotherapeutic drugs including methotrexate, cytarabine, and prednisolone. Three patients underwent irradiation therapy of the whole brain and optic nerve. While initial improvement in the ophthalmic abnormalities, such as optic disk edema, flame-shaped retinal hemorrhages, and dilation of the retinal vein, was noted, optic atrophy was later found in all eyes.

Adolescent↗
PubMed1988

The cytosolic factor required for import of precursors of mitochondrial proteins into mitochondria.

The mechanism of import of proteins into mitochondria was studied by using the peptide of the presequence of ornithine aminotransferase (the extrapeptide), which was chemically synthesized and is composed of 34 amino acids. When the extrapeptide was incubated with isolated mitochondria in the presence of a rabbit reticulocyte lysate at 25 degrees C, it was imported into the mitochondrial matrix, and the import depended on the inner membrane potential, but not added ATP. The import of several precursors of mitochondrial proteins was competitively inhibited by the presence of excess extrapeptide in the reaction system, indicating that the extrapeptide and mitochondrial proteins were imported by the same machinery. Import of the extrapeptide was significantly stimulated by addition of a rabbit reticulocyte lysate, and a component of the lysate (the cytosolic factor) stimulating import of the extrapeptide was purified about 20,000 times by successive column chromatography on DEAE-cellulose and aminopentyl-Sepharose 4B. The binding of the extrapeptide to liposomes composed of egg lecithin and partially purified receptor of the precursor of mitochondrial protein (Ono, H., and Tuboi, S., (1985) Biochem. Int. 10, 351-357) required the cytosolic factor when the concentration of the peptide was less than 1.5 X 10(-8) M, suggesting that the physiological binding of the precursors of mitochondrial proteins to the receptor is dependent on the cytosolic factor. The extrapeptide and the cytosolic factor were shown to form a complex. From these results, the mechanism of binding of the extrapeptide to the receptor of the mitochondrial outer membrane is suggested to be as follows: the peptide (the precursor of mitochondrial protein) and the cytosolic factor form a complex, and then the complex is recognized by and bound to the receptor.

Adenosine Triphosphate↗
PubMed1988

Effect of 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8), an inhibitor of intracellular Ca2+ release, on autoregulation of renal blood flow in the dog.

To examine whether Ca2+ release from intracellular Ca2+ store sites contributes to autoregulation of renal blood flow, experiments were performed on perfused kidneys of anesthetized dogs. Control observations showed excellent autoregulation of renal blood flow over the perfusion pressure range of 120-200 mm Hg. This autoregulatory response was not influenced by the intra-arterial infusion of 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB-8, 1.0 mg/min), an inhibitor of intracellular Ca2+ release. However, TMB-8 (0.3 and 1.0 mg/min i.a.) suppressed the renal vasoconstriction induced by intra-arterial injection of noradrenaline (0.5-2.0 micrograms). On the other hand, TMB-8 (0.3 and 1.0 mg/min) had no effect on the renal vasoconstriction induced by the Ca channel activator, BAY K 8644 (0.5-2.0 micrograms). These results show that TMB-8 has no effect on renal vasoconstriction induced by the activation of voltage-dependent Ca channels, and does not influence autoregulation of renal blood flow. Thus, Ca2+ release from intracellular stores does not appear to contribute the processes of autoregulation of renal blood flow.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1988

Effects of L-threo-dihydroxyphenylserine on spinal reflexes and decerebrate rigidity in rats.

1. The effects of a noradrenaline precursor, L-threo-3,4-dihydroxyphenylserine (L-DOPS), on spinal mono-(MSR) and polysynaptic reflexes (PSR) and decerebrate rigidity, were studied. 2. Although a low dose of L-DOPS (10 mg/kg, i.v.) did not affect MSR or PSR in C1 spinal rats, high doses of L-DOPS (50 and 100 mg/kg, i.v.) moderately enhanced the amplitudes of both MSR and PSR. 3. Clorgyline-HCl (1 mg/kg, i.v.), an MAO inhibitor, enhanced the excitatory effects of low-dose L-DOPS (10 mg/kg, i.v.) on both reflexes. 4. Benserazide-HCl (1 mg/kg, i.v.), an L-aromatic amino acid decarboxylase inhibitor, decreased the pressor effect, but not the stimulatory effects, of L-DOPS (100 mg/kg, i.v.) on MSR and PSR. 5. L-DOPS (300 mg/kg, i.p. or i.d.) did not affect the muscle tone of rigid hindlimbs caused by radio frequency lesioning of the midbrain. 6. These results suggest that the moderate enhancing effects of L-DOPS on MSR and PSR are due to conversion of L-DOPS to noradrenaline in the spinal cord.

Animals↗
PubMed1988

Different effects of norepinephrine and serotonin on the electrical toe stimulation-induced reflexes in the rat spinal cord.

1. Electrical toe stimulation was shown to elicit reflex potentials in the ipsilateral common peroneal nerve in the rat. 2. This reflex consisted of the spinal reflex and the spino-bulbo-spinal reflex (SBS reflex). 3. Administration of norepinephrine into the subarachnoid space enhanced the spinal reflex but depressed the SBS reflex. On the other hand, serotonin enhanced both reflexes. 4. These different effects of norepinephrine and serotonin suggest different control of nociceptive reactions by these biogenic amines.

Animals↗