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Biomedical subjects

J Yamada

Publications and source records attributed to J Yamada.

At least 415 records · Page 23Linked to original sources
PubMed1985

High-performance liquid chromatographic assay of antiinflammatory drugs incorporated in gel ointments. Separation and stability testing.

High-performance liquid chromatographic determinations of gabexate mesilate (FOY), prostaglandin E1 (PGE1), PGE1-alpha-cyclodextrin (PGE1-CD), prednisolone (PD) and butyl flufenamate (BF) incorporated in gel ointment were investigated. The gel ointment is composed of a carboxy vinyl polymer (1.3%, w/w) and a large amount of an aqueous organic solvent. A methanol extraction system offered simultaneous advantages of the removal of the polymer and the recovery of active ingredients from the gel phase. The recoveries of the drugs were 100%. The stabilities of PGE1, PGE1-CD, FOY, PD and BF incorporated in gel ointment, stored at 5, 25 and 40 degrees C for up to 90 days, were investigated.

Alprostadil↗
PubMed1985

Inhibition of platelet aggregation by synthetic phosphatidylcholines: possible involvement of vesiculation of platelet plasma membranes.

Synthetic phosphatidylcholines inhibited thrombin-induced aggregation of rabbit platelets. The inhibitory effect of the phosphatidylcholines increased with an increase in the chain-length of the constituent fatty acids up to 12, and then decreased, and C14:0PC and C16:0PC did not inhibit platelet aggregation. The activity of synthetic phosphatidylcholines as to induction of vesiculation of platelet plasma membranes (Kobayashi, T., Okamoto, H., Yamada, J.-I., Setaka, M. and Kwan, T. (1984) Biochim. Biophys. Acta 778, 210-218) and the inhibitory effect of these phosphatidylcholines on platelet aggregation showed the same dependence on the constituent fatty acids of the phosphatidylcholines. The amounts of phosphatidylcholines required for 50% inhibition of platelet aggregation correspond very well to those required for 15% exfoliation of acetylcholinesterase activity, suggesting that there is a close relationship between platelet aggregation and vesiculation of the platelet plasma membrane. The possible mechanism of inhibition of platelet aggregation by synthetic phosphatidylcholines is discussed.

Acetylcholinesterase↗
PubMed1985

Cells of origin of spinopontine fibers in the rat.

When wheat germ agglutinin-horseradish peroxidase conjugate was injected into the caudal part of the medial, lateral, ventral and peduncular pontine nuclei in the rat, retrogradely labeled spinal neurons were found contralaterally in the intermediate basilar nucleus (IBN) in the upper two cervical cord segments, and in laminae VI and VII in the lumbar cord segments. The IBN appeared to send fibers mainly to the caudomedial part of the pontine nuclei, while laminae VI and VII of the lumbar cord segments of the caudolateral part of the pontine nuclei.

Animals↗
PubMed1985

Indoleacetic acid-induced hypothermia and changes in serotonin metabolism in mice.

The effects of the tryptamine metabolite, indoleacetic acid (IAA) on body temperature and serotonin (5-HT) metabolism in mice were investigated. IAA at 300 mg/kg i.p. induced significant hypothermia in mice. It caused a remarkable decrease in concentration of total tryptophan (TRP) and a considerable increase in free TRP in serum. IAA increased 5-HT, 5-hydroxyindoleacetic acid and TRP in the brain, but decreased 5-HT synthesis in the brain. The 5-HT antagonist, methysergide and the 5-HT depleter, p-chlorophenylalanine did not affect IAA-induced hypothermia.

Animals↗
PubMed1985

Elevation of serum indoleacetic acid levels in rats with experimental liver failure.

Changes in the serum levels of indoleacetic acid (IAA) of liver-injured rats induced with an injection of carbontetrachloride (CCl4) or D-galactosamine (GalN) were investigated. IAA showed a marked increase of 61.8% and 102.6% in CCl4 and GalN treated rats, respectively. The elevation of IAA was observed only in the early stages of hepatic failure.

Alanine Transaminase↗
PubMed1985

Rats with congenital tremor and curled whiskers and hair.

In a colony of Kyo: Wistar strain of rats, we found animals with curled whiskers and hair. These rats exhibited tremor when they moved. There were no sex differences in phenotype and behavior, and the affected animals of both sexes were sterile. Among pairs that produced at least one tremulous offspring, 21.8% of the females and 21.7% of the males were affected; these proportions suggest that the anomaly is caused by an autosomal recessive gene. When the presumed heterozygous males were crossed with WAG/Rij females, about half of their female F1 hybrids were heterozygous, and they produced 26.1% (43/165) of the affected offspring when backcrossed to the sires. Again these results suggested that the disorder is caused by an autosomal recessive gene. We tentatively designated the gene as tremor (tm). The main pathological changes were seen in the gonad and central nervous system. The gonads of both sexes were aplastic even in adult animals. Vacuole formation was seen widely in the central nervous system and sometimes exhibited a spongy appearance. After administration of alpha-methyl-p-tyrosine, the norepinephrine content of the cerebellum was high, indicating that some anomalies of catecholamine release were present. The mutation is being maintained by random mating of the littermates of affected animals. Detailed pathological, endocrinological, neuropharmacological, and genetical studies are proceeding.

Animals↗
PubMed1985

The relative frequency and topographical distribution of somatostatin-, GRP-, APP-, glucagon-, 5-HT-, and neurotensin-immunoreactive cells in the proventriculus of seven species of birds.

The relative frequency and topographical distribution of proventricular endocrine cells were examined immunohistochemically in seven species of birds: common finch, pigeon, quail, chicken, duck, gull and kite. Gastrin releasing peptide (GRP), somatostatin-, avian pancreatic polypeptide (APP)-, glucagon-, 5-hydroxytryptamine (5-HT)- and neurotensin-immunoreactive cells were observed in this study. GRP- and somatostatin-immunoreactive cells were found in all species examined. All six kinds of immunoreactive cells were found with varying frequency in the pigeon, quail and gull, but not all immunoreactives were found in the other species examined. Species differences with regard to the relative frequency and topographical distribution of proventricular endocrine cells were observed.

Animals↗
PubMed1985

Histological and immunohistochemical studies of the Segi's cap, a large aggregation of endocrine cells on the intestinal villi of porcine fetuses and neonates.

Segi's cap, a large aggregation of endocrine cells on the top of intestinal villi, was studied in porcine fetuses and neonates by histological and immunohistochemical methods. The following observations were made: 1) Segi's caps were found in the proximal small intestine in all fetuses larger than 17 cm (beyond 10 weeks of gestation), in neonates before suckling and in 1-4 day-old piglets (suckling neonates); they were not found in a 1 week-old animal. 2) Segi's caps were seen more frequently in the distal duodenum and proximal jejunum than in the proximal and middle duodenum. 3) The Segi's cap consisted mainly of numerous argyrophil cells as demonstrated by Grimelius' method and a few argentaffin cells as identified by a modified Masson-Hamperl's method. 4) Immunohistochemically, ten kinds of immunoreactive cells were dispersed in the mucosal epithelium, outside of Segi's caps, in the proximal small intestine of fetuses: 5-hydroxytryptamine (5-HT)-, gastrin-, bovine pancreatic polypeptide (BPP)-, secretin-, somatostatin-, cholecystokinin-, gastric inhibitory polypeptide (GIP)-, motilin-, leucine-enkephalin- and neurotensin-immunoreactive cells. Except for neurotensin-immunoreactive cells, all of these cells were detected also in the caps. 5) Regional differences were noted in the distribution of cells in the caps; gastrin-, BPP- and secretin-immunoreactive cells were dominant in the caps in the proximal duodenum, while 5-HT-immunoreactive cells were most numerous in those in the proximal jejunum.

Animals↗
PubMed1985

Histologic and immunocytochemical study of endocrine cells in the gastrointestinal tract of the cow and calf.

The regional distribution and relative frequency of argyrophil cells, and of cells immunoreactive for 5-hydroxytryptamine (5-HT), substance P (SP), somatostatin, glicentin, glucagon, bovine pancreatic polypeptide (BPP), gastrin, leucine-enkephalin, gastric inhibitory polypeptide (GIP), cholecystokinin, secretin, motilin, and neurotensin were studied in 9 segments from the gastrointestinal tract of cows (greater than 1 year old) and calves (less than 3 months old). Argyrophil cells, 5-HT-immunoreactive cells, and somatostatin-immunoreactive cells were distributed throughout the gastrointestinal tract, whereas the other immunoreactive cells were more restricted in distribution. Most endocrine cells were more numerous in the calf than in the cow. This feature was most conspicuous in the abomasum. In the abomasum, argyrophil cells in the cow and calf and 5-HT-immunoreactive cells in the calf were found predominantly in the fundic region, whereas somatostatin-immunoreactive cells and gastrin-immunoreactive cells in the cow and calf and 5-HT-immunoreactive cells in the cow were most numerous in the pyloric region. Substance P-, glucagon-, BPP-, and leucine-enkephalin-immunoreactive cells were rarely detected. In the small intestine, argyrophil cells, 5-HT-, SP-, somatostatin-, gastrin-, GIP-, cholecystokinin-, secretin-, and motilin-immunoreactive cells were most numerous in the duodenum. Neurotensin-, glicentin-, glucagon-, and BPP-immunoreactive cells were detected with the highest frequency in the ileum. In the large intestine, argyrophil cells and 5-HT-, glicentin-, BPP-, somatostatin-, glucagon-, and SP-immunoreactive cells occurred with the highest frequency in the rectum.

Abomasum↗
PubMed1985

[Clinical experience with cefmenoxime (CMX) in complicated urinary tract infections].

Cefmenoxime (CMX) was intravenously administered to 106 patients with complicated urinary tract infection at a daily dose of 2-4 g for 5 days. An excellent response in overall clinical efficacy was seen in 15 cases (18.3%), a moderate response in 46 cases (56.1%) and poor response in 21 cases (25.6%). Pyuria was cleared in 20 cases (24.4%), decreased in 22 cases (26.8%) and unchanged in 40 cases (48.8%). Bacteriuria was eliminated in 41 cases (50.0%), decreased in 17 cases (20.7%), relapsed in 7 cases (8.5%) and unchanged in 17 cases (20.7%). Bacteriologically, 74 (76.8%) of the 95 strains isolated were eradicated by CMX, and 22 (23.2%) persisted. Side effects were observed in 3 (abdominal pain, diarrhea and elevation of trans amylase) of the 106 cases. Judging from the above results, CMX is considered to be a useful drug in the treatment of complicated urinary tract infections.

Adolescent↗
PubMed1985

[Effect of human recombinant beta-interferon on natural killer activity of peripheral lymphocytes in cancer patients].

After human recombinant beta-interferon (ReIFN-beta) was administered to 13 cancer patients intrathoracoperitoneally and by intravenous drip infusion every day or 3 times a week, the effect of peripheral lymphocytes on natural killer (NK) activity was studied. When ReIFN-beta was given every day or 3 times a week, the NK activity was notably enforced, and was maintained throughout the period of administration. NK activity was also enforced regardless of whether ReIFN-beta was given intravenously on intrathoracoperitoneally. By the administration of ReIFN-beta, pleural effusion and ascites in three patients were depleted, and in one patient, Douglas' cul-de-sac tumor disappeared. It was therefore suggested that ReIFN-beta was effective against the cavity of carcinomatosis.

Adult↗
PubMed1985

Quantitative distribution of enteroendocrine cells in the gastrointestinal tract of the adult opossum, Didelphis virginiana.

The distribution and quantification of enteroendocrine cells exhibiting immunoreactivities to nine peptides and one amine were examined in the gastrointestinal mucosa of the adult opossum using specific immunocytochemical methods. In the stomach, 90% of the enteroendocrine cells are confined to the pyloric glands and this region contained 73% of the gastrin-containing cells, 60% of the somatostatin-containing cells and 9% of cells reactive for 5-HT. Enteroendocrine cells showing immunoreactivities to glucagon, pancreatic polypeptide, somatostatin and 5-HT were observed scattered within the oxyntic glands. Only somatostatin and 5-HT positive cells were found in the cardiac glands. Immunoreactivities to CCK, glucagon, gastrin, BPP, somatostatin, secretin, motilin, neurotensin, GIP and 5-HT were observed in the epithelium of the small intestine. Although considerable variation exists in the distribution of individual enteroendocrine cell types along the intestinal tract, nearly equal numbers of enteroendocrine cells were observed in each segment. The percentage of enteroendocrine cells increases distally in the colon. Of the three enteroendocrine cell types present, somatostatin- and 5-HT-immunoreactive cells are evenly distributed, whereas neurotensin-immunoreactive cells increase in numbers distally, resulting in an increase in total number.

Animals↗
PubMed1984

Participation of peroxisomal beta-oxidation system in the chain-shortening of a xenobiotic acyl compound.

A drug, (E)-3-[4-(1-imidazolylmethyl)phenyl]-2-propenoic acid, was metabolized to 4-(1-imidazolylmethyl)benzoic acid in isolated hepatocytes of rats, which was enhanced markedly by the pretreatment of rats with clofibrate. With liver homogenates, the formation of the CoA-ester of this drug and its subsequent chain-shortening were demonstrated. In the series of these reactions, acyl-CoA synthetase, CoA, ATP and NAD were required, whereas cyanide did not inhibit the reaction. These results indicate that peroxisomes are capable of shortening the acyl side-chains of drugs by the beta-oxidation, giving an additional suggestion on the functions of peroxisomes.

Acrylates↗
PubMed1984

Vesiculation of platelet plasma membranes. Dilauroylglycerophosphocholine-induced shedding of a platelet plasma membrane fraction enriched in acetylcholinesterase activity.

Incubation of washed rabbit platelets with suspensions of dilauroylglycerophosphocholine resulted in the shedding of vesicles without causing any appreciable leakage of cytoplasmic marker (lactate dehydrogenase) or organelle marker [( 14C]serotonin). The response was dependent on incubation time, concentration of dilauroylglycerophosphocholine and reaction temperature. Vesicles were separated from platelets and exogenous dilauroylglycerophosphocholine by a series of centrifugation steps. An average diameter of vesicles was 100-200 nm on scanning electron microscopy. Vesicles were enriched 5-fold in plasma membrane marker enzyme, acetylcholinesterase, whereas specific activities of lactate dehydrogenase and intracellular membrane marker enzyme, NADH-cytochrome c reductase were decreased in vesicles. Protein analysis by SDS-polyacrylamide gel electrophoresis showed that actin and actin-binding protein were present, while myosin was barely detectable in vesicles. Vesicles contained all phospholipid species of intact platelets and cholesterol but almost 50% of phospholipids in vesicles was dilauroylglycerophosphocholine. The phospholipid to protein ratio in vesicles was about 6.5-times higher than in intact platelets.

Acetylcholinesterase↗