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H Kitagawa

Publications and source records attributed to H Kitagawa.

At least 145 records · Page 8Linked to original sources
PubMed1998

Norepinephrine efflux evoked by potassium chloride in cat sympathetic nerves: dual mechanism of action.

Using a dialysis technique, prominent efflux of norepinephrine (NE) from cardiac sympathetic nerve endings was observed under local administration of potassium chloride (KCl, 100 mM). KCl induced NE efflux was suppressed by omega-conotoxin GVIA or desipramine but residual efflux of NE was still detectable. In the presence of omega-conotoxin GVIA, KCl induced efflux of NE was augmented by pretreatment with reserpine, indicating that this efflux of NE was derived from axoplasma with neurotransporter. These data suggest that a KCl induced brisk increase in dialysate NE levels might occur as a consequence of exocytotic NE release and carrier mediated outward NE transport from nerve endings.

Adrenergic Uptake Inhibitors↗
PubMed1998

Molecular cloning and expression of glucuronyltransferase I involved in the biosynthesis of the glycosaminoglycan-protein linkage region of proteoglycans.

We isolated a cDNA encoding a novel glucuronyltransferase from human placenta cDNA with the use of the degenerate reverse transcriptase-polymerase chain reaction method. Degenerate primers were designed based upon the amino acid sequence alignment of rat glucuronyltransferase (GlcAT-P) involved in the biosynthesis of the carbohydrate epitope HNK-1 with putative proteins in Caenorhabditis elegans and Schistosoma mansoni. The new cDNA sequence revealed an open reading frame coding for a protein of 335 amino acids with a type II transmembrane protein topology. The amino acid sequence displayed 43% identity to the rat GlcAT-P, and the highest sequence identity was found in the COOH-terminal catalytic domain. The expression of a soluble recombinant form of the protein in COS-1 cells produced an active glucuronyltransferase with marked specificity for a glycoserine Galbeta1-3Galbeta1-4Xylbeta1-O-Ser. In contrast, asialoorosomucoid, which contains the Galbeta1-4GlcNAc sequence and is a good acceptor substrate for the GlcAT-P, did not serve as an acceptor. The reaction product was sensitive to beta-glucuronidase digestion and co-chromatographed with authentic GlcAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser in high-performance liquid chromatography, suggesting that the enzyme is a beta1, 3-glucuronyltransferase. These results indicate that this new member of the glucuronyltransferase gene family is the enzyme previously described as glucuronyltransferase I that forms the glycosaminoglycan-protein linkage region, GlcAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser, of proteoglycans.

Amino Acid Sequence↗
PubMed1998

Atmospheric radiocarbon calibration to 45,000 yr B.P.: late glacial fluctuations and cosmogenic isotope production

More than 250 carbon-14 accelerator mass spectrometry dates of terrestrial macrofossils from annually laminated sediments from Lake Suigetsu (Japan) provide a first atmospheric calibration for almost the total range of the radiocarbon method (45,000 years before the present). The results confirm the (recently revised) floating German pine chronology and are consistent with data from European and marine varved sediments, and combined uranium-thorium and carbon-14 dating of corals up to the Last Glacial Maximum. The data during the Glacial show large fluctuations in the atmospheric carbon-14 content, related to changes in global environment and in cosmogenic isotope production.

Journal Article↗
PubMed1998

Trypsinogen expression and early detection for peritoneal dissemination in gastric cancer.

BACKGROUND AND OBJECTIVES: The most reliable method for the diagnosis of peritoneal dissemination of gastric cancer at the present time is cytological examination of ascitic fluid, which is unavailable to patients without ascites or may be inadequate for those with ascites containing few cancer cells. It has been reported recently that human gastric cancer immunoreacted with a monoclonal antibody against pancreatic trypsinogen. We therefore examined the expression of trypsinogen as a new marker for the early diagnosis of peritoneal dissemination of gastric cancer. METHODS: Pancreatic trypsinogen protein was immunohistochemically stained with a three-step indirect immunoperoxidase method and cationic trypsinogen (trypsinogen-1) mRNA expression was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in gastric cancer. Twenty-nine of 30 primary tumors (97%) and all 12 tumors (100%) of the peritoneal seedings immunohistochemically reacted with trypsinogen. Preliminary study for early diagnosis of peritoneal dissemination was carried out for eight more recent patients who showed positive immunoreactivity to trypsinogen protein and expressed trypsinogen- mRNA in the primary tumor. The expression of trypsinogen-1 mRNA was detected by using peritoneal lavage fluid preoperatively collected in these patients. RESULTS: All three patients in whom peritoneal dissemination was diagnosed at the time of their operation(s) expressed trypsinogen-1 mRNA. One patient, who did not show peritoneal dissemination at the operation but was positive for trypsinogen-1 mRNA detection, later died of the recurrence of peritoneal dissemination. CONCLUSIONS: These results indicated that trypsinogen protein and trypsinogen-1 mRNA frequently expressed in peritoneal dissemination as well as primary tumors in gastric cancer and detection of trypsinogen-1 mRNA expression was a useful method for early diagnosis in peritoneal dissemination of gastric cancer.

Adenocarcinoma↗
PubMed1998

Bafilomycin A1 induces apoptosis in the human pancreatic cancer cell line Capan-1.

Bafilomycin A1, a specific inhibitor of vacuolar type H(+)-ATPase, can inhibit the growth of a variety of cultured cells in a dose-dependent manner, but its mechanism is unclear. The aim of this study was to examine whether bafilomycin A1 inhibits the growth of Capan-1 human pancreatic cancer cells through apoptosis. The effect of bafilomycin A1 on tumour growth in vitro and in vivo was examined using an MTT assay and an in vivo tumour model. The presence or absence of apoptosis was determined by morphology and DNA analysis of tumour cells. The concentration of bafilomycin A1 for 50 per cent inhibition of cell viability during 72 h by the MTT assay was 5 nm. In DNA analysis, a ladder of fragmented DNA was detected in Capan-1 cells treated with bafilomycin A1 at concentrations greater than 10 nm for 24 h. Nude mice bearing a xenografted Capan-1 cell line tumour received 4 weeks of bafilomycin A1 (1.0 mg/kg per day). This treatment significantly inhibited tumour growth compared with controls after 21 days (P < 0.05). Histopathological examination of tumour cells in the treated group demonstrated signs of apoptosis with chromatin condensation and cell shrinkage. These observations suggest that bafilomycin A1 inhibits the growth of Capan-1 human pancreatic cancer cells through apoptosis.

Adenocarcinoma↗
PubMed1998

Effects of coil orientation and magnetic field shield on transcranial magnetic stimulation in cats.

To obtain suitable stimulus conditions for transcranial magnetic stimulation, the evoked compound muscle action potential (ECMAP), evoked spinal cord potential (ESCP), and magnetic and electric fields were analyzed in cats with and without the use of a magnetic field shield. Cats were stimulated using a figure 8 magnetic coil placed on the cranium above the motor cortex. The maximum ECMAP amplitude was recorded when the electric current in the coil was in the mediolateral direction, regardless of whether a magnetic shield with a 5 x 5 cm window was used. ECMAP and ESCP thresholds were reduced when magnetic shielding was in place. Due to the edge effect, the strengths of the magnetic and electric fields were highest in the brainstem area, which is an inhomogeneous volume conductor of the cat's cranium. A large induced electric field directed caudally elicited ECMAP and ESCP responses effectively when a magnetic shield with a 5 x 5 cm window was in place.

Action Potentials↗
PubMed1998

Involvement of interleukin-1 in the development of ulcerative colitis induced by dextran sulfate sodium in mice.

Dextran sulfate sodium (DSS)-induced colitis in mice has been recognized as a model for human ulcerative colitis. Using this model, the effects of anti-murine interleukin 1beta (IL-1beta) antibodies (anti-muIL-1beta) and recombinant murine IL-1 receptor type I (rmuIL-1R) on the development of colitis were examined to determine whether IL-1 plays a role in colitis. Furthermore, RT-PCR amplification was used to examine for the presence of mRNAs for IL-1alpha and IL-1beta in the large intestine. In mice with colitis induced by DSS, administration of anti-muIL-1beta (5 mg/kg, once/week, i.p.) significantly suppressed body weight loss and shortening of the large intestine. Administration of rmuIL-1R (0.2 mg/kg or 1.0 mg/kg, once/day, i.v.) significantly suppressed shortening of the large intestine. Expression of mRNAs for IL-1alpha and IL-1beta was observed in the large intestine of mice which received distilled water containing 3% DSS for 5 days. The expression tended to increase in mice which received DSS for 11 days. In contrast, mRNA expression was not observed in mice which received distilled water without DSS. These results clearly demonstrate that IL-1 is involved in the development of DSS-induced colitis in mice and suggest that downregulation of IL-1 might be useful for the treatment of patients with ulcerative colitis.

Animals↗
PubMed1998

Developmental study on reduction and kinks of the tail in a new mutant knotty-tail mouse.

The knotty-tail (knt/knt) mouse has a short and knotty tail. The tail deformity is caused by a decrease in the number of caudal vertebrae and a deformity of them in the distal part of the tail. The objective of the study was to determine how reduction and kinks of the tail region were formed during secondary body formation. By day 12.0 pc, the somitogenesis of knt/knt embryos was completed; the number of caudal somites more or less agreed with those of the caudal vertebrae in knt/knt mice and were similar to those of knt/+ embryos. On the other hand, the somitogenesis of knt/+ embryos continued up to day 12.5 pc. The somites below about the sixth caudal somite were wedge-shaped with a dorsal apex in knt/knt embryos. The location of abnormal somites also corresponded well to that of deformed caudal vertebrae. Abnormal somitogenesis was always preceded by abnormalities in the presomitic region. Under gross observation, this could be seen to become markedly thickened, and histologically its dorsoventral diameter increased in the transverse plane on days 10.5-12.0 pc. In the mesenchyme there was often obvious cell death at the boundary of the unsegmented area and the tail bud after day 10.5 pc. These results suggested that the shortness of tail was primarily caused by the agenesis of distal caudal vertebrae following the agenesis of distal caudal somites, and partly by the disappearance of the presomitic part due to cell death, while the tail kinks were caused by the deformation of each caudal vertebra following disturbances of the caudal somites. Also, it is highly probable that the prominent cell death at the boundary of the unsegmented area and the tail bud may involve a defect or deformity of somites in this mutant.

Animals↗
PubMed1998

Efficacy of exogenous fibronectin in wound healing in malnourished rats.

BACKGROUND/PURPOSE: Fibronectin (FN) plays an important role in fibrin matrix formation during the wound healing process. The authors investigated whether exogenous FN increases the bursting strength (BS) of surgical wounds in malnourished rats. METHODS: Ninety rats were grouped according to three nutritional conditions (n = 30 in each group). All animals underwent a transverse celiotomy after 3 weeks of feeding, and FN (2 mg/body/day) was given postoperatively to 15 rats in each of the three groups. Wound BS was measured on postoperative days (PODs) 3, 5, and 7 after removal of the sutures. RESULTS: BS in normally nourished rats (group N; 142.6+/-23.4 mmHg) was significantly higher than that in protein malnourished rats (group PM, 110.2+/-11.2 mm Hg) and protein/ calorie (Cal)-malnourished rats (group PCM, 76.5+/-10.7 mm Hg) on POD 7 (P<.01). However, BS values for groups PM + FN (147.0+/-21.1 mmHg) and PCM + FN (115.1+/-28.9 mm Hg) were intensified significantly in comparison with groups PM and PCM (P<.01). Plasma FN levels in rats of the three FN nontreated groups were similarly decreased on POD 3 or 5, but returned to the preoperative level on POD 7, whereas those for the other three FN-treated groups increased after POD 3. CONCLUSION: Intravenous administration of FN might strengthen the weakened wounds of malnourished animals.

Abdominal Injuries↗
PubMed1998

A sensitometric comparison of Kodak Ektavision and Fuji Super HR-S panoramic radiographic films.

OBJECTIVES: The purpose of this study was to compare the combination of Ektavision film and Ektavision intensifying screen with the combination Super HR-S panoramic radiographic film and HR-4 intensifying screen with respect to sensitometric properties and the visualization of anatomic structures. METHODS: The density response and resolution of both panoramic radiographic film/intensifying screen combinations were evaluated through use of the generated characteristic curves and the modulation transfer function. The diagnostic clarity was evaluated by five oral and maxillofacial radiologists who used a rating scale to evaluate the image clarity of selected anatomic structures. RESULTS: The film speed and radiographic contrast, respectively, were 1.3 and 1.2 times higher for Ektavision than for Super HR-S. The image resolution with Ektavision was similar to that with Super HR-S. Ektavision was perceived to provide clearer images of the selected anatomic details than did Super HR-S. CONCLUSION: With respect to the clarity of anatomic structures, Ektavision film, with its higher speed and higher contrast, proved superior to Super HR-S film.

Absorptiometry, Photon↗
PubMed1998

DNA fragmentation and HSP72 gene expression by adenovirus-mediated gene transfer in postischemic gerbil hippocampus and ventricle.

A replication defective adenoviral vector containing the E. coli lacZ gene (AdCMVnLacZ) was directly injected into right hippocampus and lateral ventricle immediately after 5 min of transient global ischemia in gerbils. The relations between the lacZ gene expression and DNA fragmentation or heat shock protein 72 (HSP72) immunoreactivity were examined up to 21 days post ischemia. The lacZ gene was transiently expressed at 1 day in the hippocampus except around the CA1 region, while a large number of the periventricular cells strongly expressed the lacZ gene from 8 h to 7 days. In CA1 layer, terminal deoxynucleotidyl dUTP nick end labeling (TUNEL) positive cells, which were present only adjacent to the needle track at 8 h to 1 day, became more extensive in the whole CA1 layer at 3 to 7 days. TUNEL-positive cells were also detected around the DG at 1 day, around the needle track at 8 h to 3 days, and in the choroid plexus cells at 7 days. HSP72 staining was detected in the subiculum at 1 to 3 days, the dentate granule cells at 8 h to 1 day, and in the CA3 or CA4 pyramidal cells at 1 to 3 days. Some lacZ expressing cells were double-positive with HSP72 in DG, while the majority of those were distinguished from the TUNEL-positive cells. Pyramidal neurons were almost completely lost in the CA1 sector at 7 days after the ischemia. The present study demonstrates the successful LacZ gene transfer into the hippocampus and ventricle of postischemic gerbil brain except in the vulnerable CA1 layer by adenoviral vector injection. However, adenovirus-mediated gene transfer may induce indirect apoptotic cell death in the DG and ventricle, in addition to direct traumatic injury around the needle track.

Adenoviridae↗
PubMed1998

Myocardial interstitial noradrenaline monitoring during occlusion of inferior vena cava in cats.

To investigate myocardial interstitial noradrenaline (NA) kinetics during activation of systemic sympathetic nerves, we applied a dialysis technique to the left ventricle of anaesthetised cats and monitored myocardial interstitial NA levels during 6-min occlusion of the inferior vena cava (IVC). Dialysis probes were implanted in the left ventricular wall, and dialysate NA levels as an index of myocardial interstitial NA levels, were measured with high-performance liquid chromatographic-electrochemical detection. During IVC occlusion, dialysate NA levels progressively increased from 110 +/- 17 pmol L-1 in the control and reached 620 +/- 160 pmol L-1 at 4-6 min of IVC occlusion. Local administration of omega-conotoxin GVIA at 10 microM decreased the control dialysate NA level to 35 +/- 0.2 pmol L-1. The IVC occlusion induced increase in dialysate NA was suppressed only at 0-2 min of IVC occlusion. Intravenous injection of omega-conotoxin GVIA (10 micrograms kg-1) did not increase the dialysate NA levels during IVC occlusion. Local administration of desipramine at 100 microM increased the control dialysate NA level to 900 +/- 73 pmol L-1. The IVC occlusion induced progressive increase in dialysate NA was augmented at 2-6 min of IVC occlusion. These results suggest that the early increase in myocardial interstitial NA levels is mainly caused by neuronal release of NA from cardiac sympathetic nerve terminals, and that extraction from the circulation and neuronal NA uptake contribute to changes in myocardial interstitial NA levels after a delay of several minutes.

Adrenergic Uptake Inhibitors↗
PubMed1998

Distribution of lymphoid tissue in the caecal mucosa of chickens.

In order to clarify the fundamental structure of the host defence mechanism in chicken caeca, a detailed analysis of the distribution of lymphoid nodules (LNs) was carried out on longitudinal sections of both the mesenteric (side of the ileocaecal ligament) and the antimesenteric mucosa. An overwhelming majority of solitary or aggregated LNs were located in the mesenteric mucosa, although a few were also found in the antimesenteric mucosa. Of the total LNs, 45.7% were detected at the proximal 7.8% section in the caecal tonsil. LNs (21.4%) were also concentrated in the distal 22.0% section corresponding to the apex. A moderate concentration of LNs (13.1%) was found at the transitional 20.0% region between the base and body. Approximately 80.2% of total LNs were found at the above 3 regions in the mesenteric mucosa. In many cases, the frequency of LNs in the caecal tonsils was opposite to that at the apices. Aggregated LNs were mainly found in the caecal tonsils, transitional region and apex. Almost all aggregated LNs consisted of fundamental nodular units possessing M cells in their follicle associated epithelia. The aggregated LNs in the above 3 regions therefore could provide immunological surveillance against caecal luminal contents. In particular, the cooperative function between LNs of the caecal tonsil and apex might be highly important in maintaining the caecal microenvironment.

Animals↗
PubMed1998

Proliferation and cellular kinetics of villous epithelial cells and M cells in the chicken caecum.

The proliferation sites and cellular kinetics of villous epithelial cells and M cells in the intestine of the adult chicken have never been clarified. In this study, we determined the proliferation sites in the chicken caecum using colchicine treatment and detection of proliferative cell nuclear antigen (PCNA). The cellular kinetics of these cells were also studied using bromodeoxyuridine (BrdU) as a tracer. Enterocytes in their mitotic period were observed along the entire length of the intestinal crypt of the caecum, with a denser distribution in the middle portion of the crypt, except for the caecal tonsil. The centres of distributions were at 49% of the distance from the bottom of the crypt in the base and 41% in the apex of the caecum. In the caecal tonsil, the centres of distributions were at 64% in the long type of crypt from the bottom of the crypt and at 44% in the short type of crypt. On the other hand, the PCNA-positive enterocytes were distributed more densely at the bottom of the crypt, except for the caecal tonsil. The centres of distributions were at 36% in the base from the bottom of the crypt, 37% in the body, and 34% in the apex. In the caecal tonsil, they were at 54% in the long type of crypt and 44% in the short type. The BrdU-labelled enterocytes reached to the basement of the intestinal villi in all caecal portions at 1 d after the BrdU administration. The leading edge of the labelled enterocytes disappeared from the villous tips at 4 d in the base and the body and 3 d in the apex. In the caecal tonsil, the BrdU-labelled microvillous epithelial cells and the M cells appeared near the orifice of the crypt at 1 d, and BrdU-labelled M cells were not observed in the crypt. Thereafter, almost all of these cells disappeared at 5 d from the follicle associated epithelium (FAE). These results suggest that M cells are transformed from their precursors within 1 d, and the turnover time for M cells occurs within 4 d after the cell division of the precursors.

Animals↗
PubMed1998

Ameliorative effect of glial cell line-derived neurotrophic factor on brain edema formation after permanent middle cerebral artery occlusion in rats.

Glial cell line-derived neurotrophic factor (GDNF) was applied topically on the brain surface immediately after permanent middle cerebral artery (MCA) occlusion in rats. In contrast to the cases treated with vehicle, a formation of brain edema was significantly reduced at one day by the treatment with GDNF. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end labeling (TUNEL) staining was markedly reduced in the cases with GDNF treatment at 12 h after MCA occlusion. However, the induction of immunoreactive 70-kd heat shock protein (HSP70) was slightly ameliorated by the GDNF treatment. The present results suggest that the treatment with GDNF has a significant effect on ameliorating brain edema formation after continuous brain ischemia, and the effect is greatly associated with the reduction of apoptotic changes, but slightly with that of stress response of cells.

Administration, Topical↗
PubMed1998

Temporal profile of adenovirus-mediated E. coli lacZ gene expression in normal and post-ischemic gerbil hippocampus and ventricle.

A replication-defective adenoviral vector containing the E. coli lacZ gene was directly injected into normal and post-ischemic gerbil right hippocampus and lateral ventricle, and temporal profiles of the exogenous gene expression were compared. In case of ischemia, common carotid arteries (CCA) were transiently occluded for 5 min, and the adenoviral vector was administered just after the reperfusion. The animals were recovered for 8 h, 1, 3, 7 or 21 days. A small to moderate number of neural cells in the normal hippocampus expressed the gene from 1-3 days except for the cells around dentate gyrus (DG) and the needle route that began to express from 8 h of injection. Some normal hippocampal cells persisted the expression until 7 days. A moderate to large number of ventricular cells expressed the lacZ gene from 8 h to 7 days in the normal brain. On the other hand, no expression of the lacZ gene was observed in the post-ischemic hippocampus at 8 h including cells at DG and the needle route. Hippocampal CA1 neurons, that were selectively lost at 7 days of reperfusion, never expressed the gene throughout the post-ischemic course. The other hippocampal cells such as CA3 and dentate granule cells that survived ischemia expressed the gene only transiently at 1 day. A robust expression of the gene persisted in the ventricular cells from 8 h to 7 days. The majority of brain cells in the hippocampus that expressed the lacZ gene was not the pyramidal neurons, but small neurons at around the pyramidal layers of DG. Some astroglial, but no microglial, cells expressed the lacZ gene in the hippocampus. The present study shows that an expression of the lacZ gene was limited in the post-ischemic gerbil hippocampus especially at the vulnerable CA1 layer in contrast to the strong and persistent expression in the ventricular cells, and that the majority of beta-gal positive cells were not the pyramidal neurons but small neurons at around the cell layer both in the control and post-ischemic gerbil hippocampus.

Adenoviridae↗
PubMed1998

Reduction of ischemic brain injury by topical application of glial cell line-derived neurotrophic factor after permanent middle cerebral artery occlusion in rats.

BACKGROUND AND PURPOSE: Glial cell line-derived neurotrophic factor (GDNF) plays important roles in the survival and recovery of some mature neurons under pathological conditions. However, the effect of GDNF in ameliorating ischemic brain injury has not been well documented. Therefore, we investigated a possible effect of GDNF on the changes of infarct size, brain edema, DNA fragmentation, and immunoreactivities for caspases after permanent middle cerebral artery occlusion (MCAO) in rats. METHODS: For the estimation of ischemic brain injury, we calculated the infarct size of MCA region and also measured the brain water content as edema formation at 24 hours after the MCAO. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick labeling (TUNEL) staining was performed for the detection of DNA fragmentation. Immunoreactivities for caspase-1 (ICE), caspase-2 (Nedd-2), and caspase-3 (CPP32) were stained. RESULTS: Both infarct size and brain edema after permanent MCAO were significantly reduced by topical application of GDNF (48% and 30% decreases, P=0.01). TUNEL staining and immunoreactivities for caspases were markedly induced at 12 hours after permanent MCAO in the vehicle-treated animals. However, the spatial distribution of those immunohistochemically positive cells was dissociative in each caspase. Induction of TUNEL staining and immunoreactivities for caspases-1 and -3 was greatly reduced with GDNF treatment, whereas the reduction of caspase-2 staining was only minimum. CONCLUSIONS: These data suggest that the reduction of infarct size and brain edema by GDNF was greatly associated with the reduction of DNA fragmentation and apoptotic signals predominantly through caspases-1 and -3 cascades.

Administration, Topical↗