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Biomedical subjects

N Ishihara

Publications and source records attributed to N Ishihara.

At least 55 records · Page 3Linked to original sources
PubMed1994

Characterization of the promoters of the guinea pig neutrophil cationic peptide-1 and -2 genes.

Guinea pig neutrophils contain the antimicrobial cationic peptides GNCP-1 and GNCP-2 in the granules. To understand the regulation of the gene expression, the promoters for the GNCP-1 and GNCP-2 genes were characterized. Sequencing analysis of the genomic clones showed that the nucleotide sequences of the 5'-upstream regions (1.7 kb) from exon 1 were homologous (90-93%) between the GNCP-1 and GNCP-2 genes. However, transient transfection assays using luciferase reporter gene constructs revealed that the promoter activity of GNCP-1 was 2-fold greater than that of GNCP-2. Furthermore, DNase I footprint analysis demonstrated that three regions (I, II and III) were protected on the GNCP-1 promoter, whereas only two protected regions (II and III) were identified on the GNCP-2 promoter. Together these observations indicate that GNCP-1 and GNCP-2 are encoded by homologous genes, but the expression of the GNCP-1 and GNCP-2 genes is likely to be different at the level of transcription.

Amino Acid Sequence↗
PubMed1994

Double ventricular responses during extrastimulation of atrioventricular nodal reentrant tachycardia.

In patients with dual atrioventricular (AV) nodal pathways, double ventricular responses to a single atrial depolarization have been shown to occur, but virtually only during atrial pacing in sinus rhythm. We report on a patient with a slow-fast form of AV nodal reentrant tachycardia who exhibited double ventricular responses following extrastimulation during AV nodal reentrant tachycardia. The phenomenon of double ventricular responses during the tachycardia was demonstrated by extrastimulation from the proximal coronary sinus. Retrograde unidirectional block in the slow pathway, and an anterograde effective refractory period that was shorter in the fast pathway than that in the slow pathway, are suggested.

Atrioventricular Node↗
PubMed1994

Longitudinal study of workers exposed to mercury vapour at low concentrations: time course of inorganic and organic mercury concentrations in urine, blood, and hair.

Seven Japanese female workers exposed to mercury vapour at a concentration of < 0.02 mg Hg/m3 (8 h/day, 44 h/week) were examined for inorganic (I-Hg) and organic (O-Hg) mercury concentrations in urine, blood, and hair after 0, 4, 8, 17, and 23 months of exposure. Both I-Hg and O-Hg concentrations in urine and hair did not increase significantly even after 23 months of exposure. The concentration of I-Hg and O-Hg in plasma and O-Hg in erythrocytes, however, increased significantly after four months of exposure, and the high concentrations were maintained until the end of the study (23 months of exposure). Absence of a significant increase in the concentration of O-Hg in hair indicates that changes in concentrations of I-Hg and O-Hg in blood could be caused by the occupational exposure to mercury vapour. These results show clearly that mercury concentration in blood indicates the uptake of mercury compared with data from before employment with mercury. Even after 23 months of exposure to mercury vapour, however, urinary mercury concentration was not affected.

Adult↗
PubMed1994

Spastic paraplegia with amyotrophy of the legs: a rare case of motor and sensory neuropathy.

A 36-year-old man who suffers from gait disturbance is reported. He noticed deformity of his feet at the age of 15. When he was 32 years old, he complained of heaviness in his lower extremities. Since then his legs have been always stiff. He had no previous illness or familial neuromuscular diseases. Neurological examination revealed no impairment of mental function or cranial nerves. Marked weakness and wasting of the feet were noted. The legs showed an inverted champagne bottle shape and pes cavus deformity was evident. Deep tendon reflexes were normal in the arms but abnormally brisk in the legs. Bilateral Babinski sign and ankle clonus were elicited. The patient tended to walk on his toes and the legs scissored. The motor nerve velocities were less than normal. Sural nerve biopsy showed reduced myelinated fiber density and increased endoneurial connective tissue. Electron microscopy showed axonal swellings filled with neurofilaments. Distal wasting and weakness involving the legs more than the arms resembled that of Charcot-Marie-Tooth disease. According to the classification by Dyck, this disorder could be referred to as hereditary motor and sensory neuropathy type V. Spastic paraplegia with amyotrophy is rare, but should be identified as a distinct disorder. Recognition of this disorder would imply the clinical and genetic heterogeneity of Charcot-Marie-Tooth disease.

Adult↗
PubMed1994

Influence of partially hydrolyzed guar gum on constipation in women.

A partially hydrolyzed guar gum preparation (PHGG, average molecular weight: 20,000), obtained as a water-soluble dietary fiber by digestion of guar gum with beta-D-endomannanase, was administered as a beverage (11 g a day, bid) to 15 constipated women for 3 weeks. Defecating frequency, pH, weight, moisture, and bacterial flora of the feces were investigated and compared with the control periods. Average total dietary fiber taken from food was 9.7 +/- 0.1 g/day during the experiment. PHGG caused an increase in the defecating frequency from 0.46 +/- 0.05 (frequency/day, M +/- SE) to 0.63 +/- 0.05. Fecal moisture significantly increased from 69.1% in the control period to 73.8% by ingestion of PHGG. Fecal moisture content also increased consistent with lowering the pH of feces (r = -0.478). The frequency of Lactobacillus spp. occurrence in feces significantly increased (p < 0.05) compared with the control period. These results clearly indicate that PHGG softens and improves the output of feces.

Adolescent↗
PubMed1993

Simple colorimetric cell-cell adhesion assay using MTT-stained leukemia cells.

A new and simple method for quantitating adhesion of leukemia cells, HL60, to endothelial cells was developed. HL60 cells were incubated with MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) which forms a blue dye of formazan in the cells. MTT did not inhibit shape change of HL60 cells induced on activated endothelial cells at 90 min. The expression of a cell adhesion molecule, LFA-1, in HL60 cells at 21 h was not inhibited by MTT. After incubation of the MTT-labeled cells and endothelial cells, non-adhered cells were washed out. Adhered cells were lysed with dimethylsulfoxide, and quantitated by measuring absorbance at 540 nm. The absorbance was well correlated with the adherent cell numbers measured by direct counting or by 51Cr-labeling method. U937 and Ramos cells were also quantitatively labeled by MTT. The method has the advantage of being easy, simple and applicable to various cell-cell adhesion assays.

Cell Adhesion↗
PubMed1993

Characterization of four new cell lines derived from small-cell gastrointestinal carcinoma.

Four human small-cell gastrointestinal carcinoma cell lines were established from tumor tissues of patients with esophageal, gastric or rectal cancer, and were studied morphologically and biochemically in comparison with small-cell lung carcinoma (SCLC) cell lines and common gastric cancer cell lines. Cells from all the small-cell gastrointestinal carcinoma lines were as small as classic SCLC cells and had characteristic neurosecretory granules. Cells from only one line grew as tightly packed spherical aggregates of floating cells, and those of the other 3 grew attached to substrate. Although high levels of creatine kinase brain isoenzyme (CK-BB) were detected in all 4 cell lines, 2 of them showed low levels of aromatic L-amino-acid decarboxylase and 3 had low levels of neuron-specific enolase (NSE). None of the lines showed simultaneous elevation of enzymes. C-myc, N-myc, and L-myc were not amplified in any of the cell lines, but c-myc mRNA was expressed in 2 lines. Our findings indicate that all small-cell gastrointestinal carcinoma cells examined belong to the variant type which is used in the classification of SCLC. Furthermore, the ECC18 line, derived from esophageal cancer, seemed to be of true endocrine cell origin, while the 3 other small-cell gastrointestinal carcinoma lines seemed to arise via neoplastic neometaplasia from adenocarcinoma cells to endocrine cells.

Aged↗
PubMed1993

[Effects of KW-3635 on the diuretic action of furosemide in rats].

The effects of KW-3635 (sodium (E)-11-[2-(5,6-dimethyl-1-benzimidazolyl) ethylidene]-6,11-dihydrodibenz-[b,e]oxepine-2-carboxylate monohydrate, CAS 127166-41-0), a novel thromboxane A2 (TxA2) receptor antagonist, on furosemide diuresis were examined in rats. After an overnight fast, the rats received either saline or drugs, and 6-hr urine samples were collected. Urine volume, urinary excretion of electrolytes and urine TxB2 were measured. The administration of KW-3635 (10, 30 mg/kg, p.o.) or BM-13505 (10, 30 mg/kg) significantly increased the diuretic effect of furosemide (10 mg/kg, p.o.). Neither drug had any effect on urinary excretion of TxB2. These results demonstrated that the diuretic effect of furosemide was potentiated by TxA2 receptor blockade with KW-3635 or BM-13505. It is suggested that the diuretic effect of furosemide might be modulated by renal production of TxA2 elicited by this drug.

Administration, Oral↗
PubMed1993

[Transient pure red cell aplasia in an adult with acute parvovirus B19 infection: observation of PVB19 DNA by polymerase chain reaction, viral antibody and erythroid cells in the bone marrow].

A 35-year-old female was referred to our hospital for fever and anemia. Physical examination was unremarkable. Complete blood count revealed microcytic hypochromic anemia and reticulocytopenia. The bone marrow cellularity was normal. Some giant pronormoblasts were seen but other erythroid cells were absent. No stainable iron was seen. Parvovirus B19 (PVB19) DNA was detectable by polymerase chain reaction. Anti-PVB19 IgM-antibody was also positive in the serum on admission. Antibodies against rubella, measles, mumps, EB virus and HBs were negative and HBs antigen was also negative. Thus the diagnosis of iron deficiency anemia complicated with pure red cell aplasia secondary to PVB19 infection was made. The PVB19 DNA was still positive on days 6 and 11, suggesting that PVB19 virus persists as long as 3 weeks after the onset of PVB19 infection. However, the erythroid cells had recovered by day 6 after admission suggesting that the development of IgM antibody successfully protected the erythroid cells from infection by the residual PVB19. Hence, careful observation for PVB19 DNA and the antibody may be necessary if immunodeficient patients developed anemia of unknown etiology.

Acute Disease↗
PubMed1992

Carcinoids and endocrine cell micronests of the minor and major duodenal papillae. Their incidence and characteristics.

BACKGROUND: There have been no reports about the incidence and characteristics of carcinoids and endocrine cell micronests (ECM) of the minor and major duodenal papillae. METHODS AND RESULTS: The minor and major duodenal papillae of 78 consecutive autopsy and 117 surgical specimens were examined histologically using mirror-image paraffin-embedded tissue samples. ECM were found frequently in these areas in hematoxylin and eosin-stained sections, and their aggregation patterns were classified into four types: nodular type (Type 1, 2 of 167 in the minor papilla and 1 of 145 in the major papilla), scattered type (Type 2, 39 of 167 and 6 of 145), orifice type (Type 3, 7 of 167 and 0 of 145), and islet-like type (Type 4, 14 of 145 and 0 of 145, respectively). Criteria of neoplastic or nonneoplastic ECM were defined tentatively by histologic and immunohistochemical analyses of the ECM. Type 4 was regarded to be atrophic or regenerating islets of Langerhans. Distinct carcinoids (Type 1), neoplastic ECM (39% of all Type 2 and 3), and nonneoplastic ECM (61% of all Type 2 and 3) were found in 1.2%, 9.0%, and 16.2% of 167 samples of the minor papilla and 0.7%, 1.4%, and 2.8% of 145 specimens of the major papilla, respectively. The endocrine cells composing the carcinoids and the ECM usually were immunoreactive for somatostatin and/or pancreatic polypeptide (PP). They were negative for S-100 beta. CONCLUSION: In duodenal papillae, especially in the minor duodenal papilla, carcinoids and ECM seem to occur more frequently than generally thought, and predominantly consist of somatostatin and/or PP containing cells.

Adolescent↗
PubMed1992

Cluster of fibronectin type III repeats found in the human major histocompatibility complex class III region shows the highest homology with the repeats in an extracellular matrix protein, tenascin.

Walking and sequencing a genome portion centromeric of CYP21B in the human MHC class III region disclosed a cluster of fibronectin type III repeats in an approximately 50-kb DNA segment. Fibronectin type III repeats are known to consist of ca. 90 amino acid residues and exist in a wide range of protein species. Homology searches in protein databases showed that the repeats found had the highest homology with the repeats of human tenascin, an extracellular matrix protein. One cDNA sequence located immediately centromeric of CYP21B, the 3' portion of which is transcribed by the opposite strand of CYP21B, was found also to have six type III repeats followed by a fibrinogen domain. Pairwise homology comparison of these repeats in the MHC locus with those of human tenascin showed a general parallelism in their gene organization, indicating that the newly found repeats are elements of certain tenascin-like genea.

Amino Acid Sequence↗
PubMed1991

Inhibitory effects of activated protein C and heparin on thrombotic arterial occlusion in rat mesenteric arteries.

Effects of human activated protein C (APC) and heparin on thrombus formation were examined using small mesenteric arteries of rats and video-recording system attached to a microscope. To induce thrombosis we damaged the vessel wall over a short segment by compression and exposed the damaged media to the blood stream. Platelet-rich thrombus enlarged gradually at the damaged site, occluded the vascular lumen for a short period and then flowed away. Such thrombus formation was observed several times after a compression damage. An intravenous administration of APC significantly decreased the total occlusion time from 6.4 +/- 0.7 min at control to 2.2 +/- 0.4 min at 0.9 mg/kg given over 1 min (mean +/- SEM, n = 6, p less than 0.01), and from 6.5 +/- 1.0 min to 1.0 +/- 0.3 min at 3.0 mg/kg (n = 6, p less than 0.01). An intravenous heparin (300 and 1000 U/kg) also decreased the total occlusion time significantly from 6.2 +/- 0.8 to 2.2 +/- 0.8 min (n = 6, p less than 0.05) and from 5.4 +/- 0.8 to 0.8 +/- 0.7 min (n = 6, p less than 0.01), respectively. APC prolonged APTT from 11 +/- 1 sec (n = 5) at control to 50 +/- 5 sec (n = 5) at 0.9 mg/kg and to 87 +/- 8 sec (n = 5) at 3.0 mg/kg, while heparin prolonged APTT to more than 120 sec in all 5 rats at both doses. APTT prolongation by APC was significantly attenuated by inhibiting its residual activity in the plasma samples using monoclonal antibody.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effects of lesioning of the substantia innominata on autoregulation of local cerebral blood flow in rats.

Recently, accumulated data have suggested that the nucleus basalis magnocellularis, i.e., the substantia innominata (SI), may represent the primary source of central cholinergic innervation in the rat cortical vasculature. We therefore examined the effects of unilateral lesion of the SI on the autoregulation of local CBF (lCBF) during induced hypotension in rats. Male Wistar rats were divided into three groups. The animals of groups 1 and 2 received an injection of 5 micrograms of ibotenate into the right SI stereotaxically. At 7 days after the injection, the lCBF was measured by the [14C]iodoantipyrine technique in the awake state. Group 1 was used as the normotensive group (MABP = 113.1 +/- 12.2 mm Hg). Group 2 formed the hypotensive group, and the lCBF was measured during hypotension (MABP = 80.0 +/- 5.5 mm Hg) induced by hemorrhage. Group 3, the sham-operated normotensive group, received vehicle injection into the right SI at 7 days prior to the lCBF measurement. In group 1, lCBF was significantly lower in the frontal, parietal, temporal, and striate cortices on the lesioned side compared to that on the contralateral side. In group 2, lCBF was significantly decreased in the cortices on the lesioned side, but there was no significant difference in magnitude of the lCBF reduction between groups 1 and 2. Group 3 exhibited no hemispheric asymmetries in lCBF. These findings suggest that the SI exerts an influence on cortical lCBF, but does not play a role in the autoregulation of lCBF during hypotension.

Animals↗