Biomedical subjects

T Chiba

Publications and source records attributed to T Chiba.

At least 451 records · Page 25Linked to original sources

PubMed1992

[The clinicopathological evaluation of automated cytochemical hematology system (Technicon H1) in patients with leukemia and myelodysplastic syndrome].

To determine the usefulness of the H1 system, we applied it to 14 patients with acute leukemia and 19 patients with myelodysplastic syndrome (MDS). We revealed interesting cytogram patterns in several patients with acute leukemia, ALL (L2), ALL (L3), and AML (M7). In the basophil and lobularity cytogram, their blast cells were clustered mainly in the blast box. However, a small cluster appeared in the basophil area and was expressed as pseudo-basophilia of 4.4%, 9.6%, and 21%, respectively. We speculated that not only normal basophils but also some type of leukemic blasts could be resistant to rupture of the cell membrane induced by a surfuctant at a low pH. Characteristics of H1 cytogram and histogram pattern have hardly been reported in patients with MDS. From the analysis of H1 pattern of 19 cases, we found that the (1) the values of RDW and HDW were high in comparison to those for aplastic anemia and normal controls and (2) the MPXI (mean peroxidase activity index) was significantly low at the time of diagnosis. MPXI had declined at the terminal stage in cases of death with bone marrow failure. These characteristics were concluded to be useful in clinicopathological diagnosis using the H1 automatic hematological system.

Adolescent↗

PubMed1992

Gastroesophageal reflux after endoscopic injection sclerotherapy.

The effect of sclerotherapy of esophageal varices on the gastroesophageal reflux was studied. Gastroesophageal reflux was monitored by a 24-h pH-monitoring catheter introduced into the distal esophagus. The results of pH monitoring of 16 patients who underwent sclerotherapy were compared with those of 21 patients with untreated varices. Seven of the 16 treated patients showed high occurrence rates of gastroesophageal reflux comparable to those observed in cases with severe reflux esophagitis. In the untreated group, only one patient showed pathological reflux (there was a significant difference between treated and untreated groups; p less than 0.01). When the level of reflux was compared with factors that might influence sclerotherapy-induced gastroesophageal reflux, there was a positive correlation between the magnitude of reflux and amount of sclerosant injected paravariceally in the submucosal tissue (p less than 0.05). The results indicate that the paravariceal injection of sclerosant for the treatment of esophageal varix may cause pathological gastroesophageal reflux after sclerotherapy is completed.

Analysis of Variance↗

PubMed1991

Growth signal erythropoietin activates the same tyrosine kinases as interleukin 3, but activates only one tyrosine kinase as differentiation signal.

By Western blotting with anti-phosphotyrosine-specific antibody, we demonstrated that both erythropoietin (Epo) and interleukin 3 (IL3) induce rapid and transient tyrosine phosphorylation of a common set of proteins of 45, 55, 69, 87, 90, 95 and 160 KDa as a growth signal in Epo- and IL3-dependent FD-M6 cells. In contrast, only two proteins of 87 and 90 KDa were transiently phosphorylated in Epo-induced erythroid differentiation of SKT6 cells. Furthermore, no tyrosine phosphorylation was observed in dimethyl sulfoxide-induced differentiation of SKT6 cells. Taken together with other observations, these results indicate that Epo, IL3 and GM-CSF activate the same tyrosine protein kinases as growth signal and that Epo-induced differentiation signal uses only a part of the tyrosine kinase pathway.

Animals↗

PubMed1991

Efferent projections of the infralimbic (area 25) region of the medial prefrontal cortex in the rat: an anterograde tracer PHA-L study.

The efferent projections of the infralimbic region (IL) of the medial prefrontal cortex of the rat were examined by using the anterograde transport of Phaseolus vulgaris leucoagglutinin (PHA-L). Major targets of the IL were found to include the agranular insular cortex, olfactory tubercle, perirhinal cortex, the whole amygdaloid complex, caudate putamen, accumbens nucleus, bed nucleus of the stria terminalis, midline thalamic nuclei, the lateral preoptic nucleus, paraventricular nucleus, supramammillary nucleus, medial mammillary nucleus, dorsal and posterior areas of the hypothalamus, ventral tegmental area, central gray, interpeduncular nucleus, dorsal raphe, lateral parabrachial nucleus and locus coeruleus. Previously unreported projections of the IL to the anterior olfactory nucleus, piriform cortex, anterior hypothalamic area and lateroanterior hypothalamic nucleus were observed. The density of labeled terminals was especially high in the agranular insular cortex, olfactory tubercle, medial division of the mediodorsal nucleus of the thalamus, dorsal hypothalamic area and the lateral division of the central amygdaloid nucleus. Several physiological and pharmacological studies have suggested that the IL functions as the 'visceral motor' cortex, involved in autonomic integration with behavioral and emotional events. The present investigation is the first comprehensive study of the IL efferent projections to support this concept.

Amygdala↗

PubMed1991

GATA-1 transactivates erythropoietin receptor gene, and erythropoietin receptor-mediated signals enhance GATA-1 gene expression.

Erythropoietin is a cytokine which specifically regulates the proliferation and differentiation of erythroid progenitor cells. The expression of erythropoietin receptor on the cell membrane of the progenitor cells is a critical event during the erythroid differentiation process. In order to clarify the tissue-specific and differentiation stage-specific expression of the erythropoietin receptor gene, its transcriptional regulation was examined by transient expression assay, gel mobility shift assay and DNase I footprinting. The results clearly showed that GATA-1 transactivates the gene expression through a single GATA motif located around -200 bp upstream from the ATG codon in a dose dependent manner. Furthermore, Northern blot analysis revealed that erythropoietin receptor-mediated signals strongly enhanced GATA-1 gene expression in accordance with the appearance of hemoglobin-positive cells. Taken together with other observations, these results suggested the following scheme of erythroid differentiation: 1)GATA-1 is expressed in the early stage of blood cell development; 2) GATA-1 transactivates the erythropoietin receptor gene; 3) erythropoietin binds its receptor and the receptor-mediated signals enhance GATA-1 gene expression in erythroid progenitor cells; and 4) GATA-1 finally transactivates hemoglobin synthesis-related genes and globin genes in relatively matured erythroid cells.

Animals↗

PubMed1991

Receptors for gastrin on gastric carcinoid tumor membrane of Mastomys natalensis.

Specific binding sites for human gastrin I (gastrin) were identified in a crude membrane preparation from the gastric carcinoid tumor of Mastomys (Praomys) natalensis. The binding of 125I-gastrin to the carcinoid tumor membrane was saturable, and Scatchard analysis of the data revealed a single class of binding site with a dissociation constant of 139.2 pM and a maximal binding capacity of 23.5 fmol/mg protein. Gastrin and CCK8 equipotently and dose-dependently displaced the binding of 125I-gastrin to the membrane. GTP but not ATP decreased 125I-gastrin binding to the membrane, and removal of Mg2+ attenuated this inhibitory action of GTP. The GTP-induced reduction of 125I-gastrin binding was found to be due to a decrease in binding affinity without a change in binding capacity. These results clearly indicate the presence of specific binding sites for gastrin, probably coupled to guanine nucleotide-binding protein, in the carcinoid tumor membrane of Mastomys, and suggest that gastrin has possible biological actions on these tumors.

Adenosine Triphosphate↗

PubMed1991

Presence of histamine H2-receptors on human gastric carcinoma cell line MKN-45 and their increase by retinoic acid treatment.

Histamine dose-dependently stimulated cyclic AMP production in human gastric carcinoma cell line MKN-45, and this effect was inhibited by cimetidine but not by pyrilamine. Moreover, not only histamine but also cimetidine displaced the specific binding of [3H]tiotidine to these cells, whereas pyrilamine had no effect. On the other hand, pretreatment of MKN-45 cells with retinoic acid (RA) significantly enhanced histamine-induced increase of cyclic AMP production, although the cyclic AMP response to either forskolin or NaF was not affected. Finally, RA treatment increased the number of histamine receptor without altering its affinity. Thus, it appears that histamine H2-receptors are present on MKN-45 cells, and that RA treatment enhances the action of histamine on these cells by increasing the number of H2-receptors.

Binding, Competitive↗

PubMed1991

Human alpha-calcitonin gene-related peptide-(8-37) as an antagonist of exogenous and endogenous calcitonin gene-related peptide.

The C-terminal fragment of the human alpha-calcitonin gene-related peptide (hCGRP), hCGRP-(8-37) competitively antagonized both the positive inotropic effect of hCGRP in the guinea-pig isolated left atria (pA2 6.89) and the smooth muscle relaxant effect of hCGRP in the rat isolated vas deferens (pA2 6.55) but left the response to isoprenaline unaffected in both preparations. In addition, hCGRP-(8-37) reduced the responses produced by activation of the 'efferent' function of capsaicin-sensitive primary afferents in both preparations thus providing pharmacological evidence for the involvement of endogenous CGRP. hCGRP-(8-37) appears a useful tool to establish the physiological role of CGRP in peripheral preparations from different species.

Animals↗

PubMed1991

Two cases of bizarre rib anomalies associated with intestinal malformation.

Two cases of bizarre skeletal anomalies associated with intestinal malformation are presented. One patient had ileal atresia and Hirschsprung's disease, and the other anorectal malformation. Abnormalities in the number and morphology of ribs and vertebrae were present. Esophageal atresia often is associated with skeletal abnormalities, including supernumerary ribs, but these usually are not severe. Despite their severe costal malformations, neither patient had any complication after surgery to correct their intestinal malformation.

Abnormalities, Multiple↗

PubMed1991

Intraganglionic portal sinus located between small intensely fluorescent (SIF) cells and principal ganglionic neurons in the inferior mesenteric ganglion of the guinea pig.

The vascular system in the inferior mesenteric ganglion of the guinea pig was studied to clarify the transport pathway of transmitters released by the small intensely fluorescent (SIF) cells to the principal ganglionic neurons. Reconstruction of about 1500 1-micron-thick serial sections of the ganglion demonstrated its portal system. SIF cells were tightly packed and formed two or three clusters under the capsule of the ganglion. Branches from the inferior mesenteric artery ran directly toward these clusters and broke up into a number of coiled and looped sinusoid capillaries among the SIF cells. They then drained into a large sinus surrounding the clusters in the ganglion. Capillaries were derived from this sinus and ramified among the principal ganglionic neurons. After supplying the neurons, these vessels drained into veins surrounding the ganglion. Therefore, as we observed two distinct groups of capillaries, we call this sinus the "intraganglionic portal sinus". All the transmitters secreted from the SIF cells are collected into this intraganglionic portal sinus and are then conveyed through the capillaries to the principal ganglionic neurons.

Animals↗

PubMed1991

Mechanism of inhibitory action of prostaglandins on the growth of human gastric carcinoma cell line KATO III.

Prostaglandins (PGs) play important roles in the regulation of various gastric functions. In this study, the effects of various PGs on the growth of the human gastric carcinoma cell line KATO III were investigated. All the PGs tested inhibited KATO III cell growth with a relative potency order of PGE2 greater than PGE1 greater than 17S,20-dimethyl-6-oxo PGE1-methyl ester (ornoprostil) greater than PGF2 alpha. This inhibition was accompanied by an increase of cyclic adenosine monophosphate production. Furthermore, in the presence of guanosine triphosphate, these PGs stimulated adenylate cyclase activity in the plasma membrane of KATO III cells, followed by enhancement of membrane guanosine triphosphatase activity. The relative potencies of these PGs for increasing cyclic adenosine monophosphate levels, activating adenylate cyclase, and enhancing guanosine triphosphatase activity were all comparable to those for inhibiting cell growth. On the other hand, the proliferation of KATO III cells was also inhibited by forskolin as well as dibutyryl cyclic adenosine monophosphate, whereas none of the agents that did not increase cyclic adenosine monophosphate levels had any effect. These results suggest that PGs inhibit KATO III cell growth by stimulating cyclic adenosine monophosphate production via a guanosine triphosphate-dependent process, suggesting the involvement of guanosine triphosphate-binding stimulatory protein, probably coupled to PGE2 receptors, in the action of PGs.

Adenylyl Cyclases↗

PubMed1991

Immuno-electronmicroscopic studies on the gamma-aminobutyric acid and glycine receptor in the intermediolateral nucleus of the thoracic spinal cord of rats and guinea pigs.

Gamma-aminobutyric acid (GABA) and glycine are known as major inhibitory neurotransmitters in the intermediolateral nucleus of the spinal cord. Distribution and density of GABA immunoreactive axon varicosities and glycine receptor immunoreactive dendrites and somata in the intermediolateral nucleus were examined by immuno-electronmicroscopy. GABA immunoreaction was observed in the axon varicosities of axo-dendritic and axo-somatic synapses. Glycine receptor immunoreaction was seen in association with the postsynaptic membrane of dendrites and soma. GABA immunoreactive axon varicosities were larger (1.01 +/- 0.49 x 1.20 +/- 0.38 microns) than axon varicosities presynaptic to glycine receptors (0.72 +/- 0.22 x 0.98 +/- 0.33 microns). The density of GABA immunoreactive axon varicosities was 3.65/100 microns 2 and that of glycine receptor immunoreactive synapses was 4.78/100 microns 2. A subpopulation of GABA immunoreactive axons (42%) made synaptic contact with glycine receptor immunoreactive dendrites or soma, indicating the coexistence of GABA and glycine.

Animals↗

PubMed1991

Target-specific projections of intrinsic ganglionic neurons with different chemical codes in the canine larynx.

The distribution and origin of peptide-containing intrinsic nerve fibers within the larynx were examined by immunohistochemistry and denervation experiments in the dog. In the normal larynx, a dense network of vasoactive intestinal polypeptide (VIP)-immunoreactive (IR) fibers was seen around the acini of submucosal glands. VIP-, substance P (SP)-, or calcitonin gene-related peptide (CGRP)-IR fibers were seen in the walls of submucosal arteries, and VIP-, neuropeptide Y (NPY)-, or enkephalin (ENK)-IR fibers were seen around the arteries in the muscle tissue. Most of these peptide-IR fibers remained after bilateral denervation of the superior and inferior laryngeal nerves. Several small intrinsic ganglia were found along the peripheral branches of the laryngeal nerves. About 97% of the ganglionic neurons were VIP-IR; of these, 44% were immunoreactive to VIP alone, 22% to VIP and NPY, 13% to VIP and SP, 7% to VIP and ENK, and 14% to VIP, NPY and SP. These results reveal that the exocrine glands and blood vessels are innervated by the intrinsic ganglionic neurons and that subpopulations of ganglionic neurons with different chemical codes innervate specific target organs in the canine larynx.

Animals↗

PubMed1991

Detection of human leucocytes by cyclic voltammetry and its application to monitoring of allergic reaction.

Cyclic voltammetry was applied to the detection of human leucocytes and the monitoring of allergic reactions. A basal plane pyrolytic graphite electrode with attached leucocytes on a porous nitrocellulose membrane filter was employed as a working electrode. An anodic peak current appeared at 0.33 V versus the saturated calomel electrode (SCE) when the potential of the working electrode was scanned in the range of 0-1.0 V versus SCE. This peak current was attributed to the electrochemical oxidation of serotonin. When egg white was added to leucocytes obtained from patients who were allergic to egg, the peak current decreased owing to degranulation of leucocytes leading to serotonin release. The peak current decreased with increasing allergen concentration in the range of 5-50 micrograms ml-1. Leucocytes did not respond to other allergens such as soybean, milk and dinitrophenylated bovine serum albumin (DNP-BSA).

Adult↗

PubMed1991

Three-D muscular arrangement at the ureteropelvic junction and its changes in congenital hydronephrosis: a stereo-morphometric study.

Ureteral walls were obtained from twelve autopsies without urological diseases and from surgical material of twelve patients operated for congenital hydronephrosis. The specimens were submitted to computer-assisted analysis of 3-D muscular architecture at the ureteropelvic junction (UPJ). Serial histologic sections in parallel with the wall were prepared. A geometric model was introduced to simplify the muscular layer, replacing bundles with vectors of corresponding size and direction. The vector distribution visualized that normally, the ureteral muscles change their arrangement with age, from a circular pattern in neonates to an oblique mesh in adults. In addition, longitudinal muscles emerged at the age of two years in the subepithelial layer. In patients with congenital hydronephrosis, not only were such growth-related changes ambiguous or lacking, but there also were various abnormalities; segmental muscular hypoplasia, disarrangement of bundles or lack of longitudinal fibers. These were considered to closely correlate with the urinary obstruction in patients with this disease.

Adolescent↗

PubMed1991

Ileal atresia with perforation in siblings.

Two siblings with ileal atresia are described; one boy presented with ileal perforation and the other with meconium peritonitis, diagnosed by antenatal ultrasonography. The site and type of atresia, complications and associated anomalies of reported cases among siblings also are discussed.

Humans↗

PubMed1991

Arterial oxygen saturation, blood pressure, and pulse rate during upper gastrointestinal endoscopy--influence of sedation and age.

We studied the effect of sedation by I.V. meperidine on blood pressure, pulse rate, and arterial oxygen saturation during upper gastrointestinal endoscopy. Meperidine increased the tolerance of the patients and attenuated the endoscopy-induced rise in blood pressure and pulse rate. Arterial oxygen saturation was transiently depressed in the first few minutes of the endoscopic procedure even without sedation, and meperidine administration did not aggravate this oxygen desaturation. Therefore, meperidine may be a favorable sedative for upper gastrointestinal endoscopy because its treatment increases the tolerance of patients and decreases cardiac oxygen demand without decreasing arterial oxygen saturation.

Age Factors↗

PubMed1991

Angiotensin-induced hypertension chemotherapy in children with advanced solid tumors.

Angiotensin-induced hypertension chemotherapy (IHC) was investigated in six children with the following advanced malignancies: hepatocellular carcinoma, extraskeletal Ewing's sarcoma, sacrococcygeal malignant teratoma, small round cell tumor of the chest wall, hepatoblastoma and osteogenic sarcoma. Partial response was achieved in three of these patients, two showed no change, and in one IHC was used as adjuvant chemotherapy. The side effects of IHC were minimal and tolerable. Angiotensin-IHC may provide a new approach to pediatric cancer chemotherapy.

Adolescent↗