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H Ihara

Publications and source records attributed to H Ihara.

At least 19 recordsLinked to original sources
PubMed1998

Cancer cells overexpress mRNA of urokinase-type plasminogen activator, its receptor and inhibitors in human non-small-cell lung cancer tissue: analysis by Northern blotting and in situ hybridization.

The transcriptional localizations of urokinase-type plasminogen activator (uPA), its receptor (uPAR) and its inhibitors (PAI-1 and PAI-2), which are possibly involved in cancer metastasis, have not been determined in human lung cancer. To identify their regulation in primary non-small-cell lung cancer, we assayed mRNA levels by Northern blot analysis in 25 cases and determined the localizations of mRNA by in situ hybridization in 10 cases. The amounts of uPA and PAI-2 mRNA were significantly higher in cancerous relative to normal lung tissues. However, no significant difference was observed in uPAR and PAI-1 mRNA levels. All transcripts were present in cancer cells and were predominantly located in tumor edges in several cases. In addition, PAI-1 transcripts were more abundant in poorly and moderately differentiated carcinomas relative to well-differentiated carcinomas and PAI-2 transcripts were more abundant in squamous cell carcinomas than in adenocarcinomas. Thus, PAIs may be involved in modulation of malignant potency. Our results indicate that human non-small-cell lung cancer cells can autonomously express the mRNAs of uPA, uPAR and PAIs, which are possibly involved in metastasis.

Adenocarcinoma↗
PubMed1998

Proteolysis of highly polysialylated NCAM by the tissue plasminogen activator-plasmin system in rats.

Tissue-type plasminogen activator (tPA), a serine protease which converts the zymogen plasminogen to the active protease plasmin, is believed to regulate neurite extension and neural cell migration by modulating extracellular metabolism. The highly polysialylated form of the neural cell adhesion molecule (NCAM-H) is strongly expressed in the developing brain and is believed to play a role in organizing the neural network. In this report, we incubated neonatal rat brain homogenates with human tPA and rat plasminogen in order to determine whether NCAM-H would be degraded. NCAM-H was degraded by plasmin which was formed from rat plasminogen by human tPA. The degradation was inhibited by the addition of plasminogen activator inhibitor type 1 (PAI-1) or aprotinin. These results suggest a possible contribution of the tPA-plasmin system to NCAM-H turnover in the developing brain.

Aging↗
PubMed1998

Purification and partial amino acid sequences of the binding protein from Bombyx mori for CryIAa delta-endotoxin of Bacillus thuringiensis.

The binding protein for Bacillus thuringiensis delta-endotoxin, CryIAa, from the brush border membrane of the midgut of Bombyx mori was purified by the dot blot method and delta-endotoxin affinity chromatography. The binding protein was purified to 235-fold enrichment from cholic acid extracts of brush border membranes from B. mori midgut by activated CryIAa-affinity chromatography and DEAE ion-exchange chromatography. The purified binding protein showed a single band of 180 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and this band specifically reacted to 125I-labeled CryIAa on Immobilon membrane. The affinity of the binding protein for CryIAa was equivalent to that of the brush border membrane vesicles and solubilized membrane proteins. Partial amino acid sequences of the binding protein showed sequence similarity to the cadherin-like binding protein for CryIAb from Manduca sexta, but not for CryIAc binding protein from M. sexta and Heliothis virescens.

Amino Acid Sequence↗
PubMed1998

Decline in plasma retinol in unconjugated hyperbilirubinemia treated with bilirubin adsorption using an anion-exchange resin.

When an anion-exchange resin column (Plasorba BR-350) was used for the treatment of unconjugated hyperbilirubinemia, we found an unexpected decrease in plasma retinol (vitamin A) concentrations in a patient with type I Crigler-Najjar syndrome. The purpose of our study was to investigate the mechanism of this decrease in plasma retinol. When the patient's serum bilirubin exceeded the bilirubin binding capacity of 14.7 mumol bilirubin/g serum albumin (i.e., 720 mumol/L of bilirubin), abrupt deterioration of the patient's neurologic status (suppression in his gait and speech) occurred, so the need to apply plasmapheresis to reduce the unconjugated bilirubin was indicated. Blood was drawn from the radial artery at a flow rate of 160 mL/min and pumped into a membrane plasma separator at a rate of 40 mL/min. The plasma was passed through the bilirubin adsorbent column and returned to the venous blood line of the plasma separator. Plasma samples were taken at the inlet and outlet of the bilirubin adsorbent column before and after treatment. The concentration of unconjugated bilirubin in plasma was effectively reduced by the perfusion, but plasma retinol was coincidentally decreased by the perfusion to vitamin A deficiency levels. The patient's plasma retinol was 2,127 nmol/L at the beginning of therapy and decreased to 1,492 nmol/L after repeated adsorption treatments. As the amounts of decrease in retinol (912 +/- 123 nmol/L) after the perfusion were almost equal to those in retinol-binding protein (1,010 +/- 192 nmol/L), retinol may have been removed as a form of holo retinol-binding protein. Decreases in retinol and retinol-binding protein levels were also observed in low-density lipoprotein (LDL) apheresis with a dextran sulfate column (i.e., a cation-exchange resin column). In the patient with Crigler-Najjar syndrome, retinol taken dietarily was removed by plasmapheresis. However, the patient manifested no clinical symptoms associated with vitamin A deficiency, since his liver storage of retinol could supply the loss caused by plasmapheresis treatment. We should measure plasma retinol concentrations to evaluate the loss of retinol during plasmapheresis treatment coupled with an anion-exchange resin column.

Adolescent↗
PubMed1998

Human thrombin and calcium bound factor Xa significantly shorten tPA-induced fibrin clot lysis time via neutralization of plasminogen activator inhibitor type 1 activity.

Employing a fibrin clot lysis assay, we reassessed the significance of the neutralization of plasminogen activator inhibitor type 1 (PAI-1) activity by thrombin and factor-Xa in fibrinolysis. When PAI-1 enriched fibrin clots were formed using increasing concentrations of thrombin (0.1, 0.5, 1.0 IU/ml), their lysis times became shorter (43.8 +/- 4.9, 25.7 +/- 3.7, 13.9 +/- 0.8 h respectively). Times were shortened further by either heparin (43.9 +/- 11.0, 12.1 +/- 2.6, 3.6 +/- 0.2 h respectively) or vitronectin (17.0 +/- 1.6, 1.9 +/- 0.7, 0.9 +/- 0.0 h respectively). Factor-Xa together with Ca++ shortened the clot lysis time further. Fibrin autography revealed that both enzymes dose dependently interfered with complex formation between tPA and PAI-1, making large amounts of tPA remaining to be free form. The mechanism seems to play a role in the coagulation associated enhancement of fibrinolysis.

Anticoagulants↗
PubMed1998

[High signal intensity of globus pallidus on T1-weighted MRI in liver cirrhosis patients: clinical and pathological study].

In some patients with liver cirrhosis, the globus pallidus shows high signal intensity on T1-weighted MRI. The relationship was examined between high signal intensity on T1-weighted images and pathological conditions such as liver function, portal venous pressure and metal concentrations in brain. The signal of the globus pallidus on T1-weighted imaging became highly enhanced in accordance with prolongation of prothrombin time, deterioration of ICG R15, or decrease in choline esterase and the Fisher ratio. Furthermore, the high signal intensity was also seen in patients with high portal pressure and large varices. In histopathological study, remarkable atrophy and loss of nerve cells were observed in globus pallidus with high signal intensity on T1-weighted imaging, changes that were similar to those in with patients with manganese poisoning. The manganese concentration in autopsied globus pallidus with high signal intensity on T1-weighted imaging showed a 9.5-fold increase compared with that with normal intensity. In conclusion, the deposition of manganese in the globus pallidus, which is accompanied with the nerve cell deciduation, brings about the high signal intensity of the globus pallidus on T1-weighted MRI in patients with liver cirrhosis.

Adolescent↗
PubMed1997

Nocturnal melatonin profiles before and one year after beginning shift-work.

Nocturnal serum melatonin profiles were determined twice for seven single women, during their time of employment as nurses (baseline), and after one year (follow up), in order to investigate the effects of shift-work on nocturnal melatonin secretion. All subjects were working in the same hospital under an irregularly rotating three-shift system. Five (5) mL blood samples were drawn six times at 2 h intervals between 20:00-06:00 hours under dim light conditions (< 50 lux). The same sampling procedures were repeated the following year. The results showed pronounced inter-individual differences in melatonin concentrations. There was a trend towards increasing maximum melatonin concentration (MAX melatonin) at follow up, with a similar tendency seen in summed melatonin (the sum of six measured melatonin concentrations). A trend was also seen towards increasing melatonin ratio at 06:00 hours (the percentage of melatonin concentration at 06:00 hours by summed melatonin) at follow up. Melatonin concentration at 06:00 hours was significantly higher at follow up, and a significant correlation between Morningness-Eveningness score (M-E score) at baseline and increased summed melatonin at follow up was also seen. These results suggest that: nocturnal melatonin secretion does not significantly increase after beginning shift-work; and that greater increases in melatonin secretion at follow up are found in subjects with higher M-E scones (increased morning type). With more subjects, however, there may be significant increase in MAX melatonin and/or summed melatonin in the follow-up study.

Adult↗
PubMed1997

[Ocular complications after renal transplantation].

Seventy-two post-renal transplant patients were studied for ocular complications. Of 72 patients, 56 (77.8%) showed some ocular abnormality. Steroid cataract was the most common complication, occurring in 45 patients (62.5%). Eleven patients (18 eyes) had undergone operations for cataract. The average of their ages was 39.7 years and the period from renal transplantation to cataract operation was 3.3 years. Postoperative visual acuity was over 20/20 in most cases. Increased intraocular pressure was encountered in 9 patients (12.5%), cytomegalovirus ocular infection in 2 (2.8%), hypertensive retinopathy in 2 (2.8%), branch retinal vein occlusion in 1 (1.4%), and subconjunctival hemorrhage in 15 (20.8%). A new immunosuppressant, cyclosporine, increased renal graft survival more than azathioprine. However, ocular complications such as steroid cataract occurred frequently in spite of the use of cyclosporine, as in the azathioprine era. In conclusion, it is necessary for renal transplant patients to receive a periodical ophthalmological check-up.

Adolescent↗
PubMed1997

[Blood amino acid levels in sarin poisoning patients].

Since plasma is generally employed for amino acid analysis, we compared amino acid levels in plasma with those in serum for healthy individuals and examined the influence of separation and storage conditions on the stability of the samples. Then, we determined the amino acid levels of frozen serum samples obtained from sarin poisoned patients. A. Comparison of Amino Acid Levels in Plasma and Those in Serum Blood was collected from 5 healthy individuals. Then, heparinated plasma and serum were separated by centrifugation immediately after blood collection. Serum was also separated by centrifugation after standing whole blood at room temperature for 1 hour. Frozen plasma and serum were store at -40 degrees C for 5 months. All were subjected to analysis in an amino acid analyzer. It was found that the cystine (Cys) and 3-methyl-histidine (3-M-His) levels in serum and plasma were affected when stored in a frozen state, that the aspartate (Asp) level was changed according to the method of collecting serum, and that the taurine (Tau) and ornithine (Orn) levels were affected by standing blood. B. Analysis of Blood Taken from Sarin Poisoned Patients Twelve sarin poisoned patients were selected as subjects, and serum cholinesterase (Ch-E) and serum albumin (Alb) levels were determined. Amino acid analysis was conducted using an amino acid analyzer. Serum samples which had been obtained from the 6 patients and frozen and stored at -40 degrees C from 5 months were used for amino acid analysis. As a result, the serum Ch-E level decreased and the Alb level tended to rise. Since the Ch-E/Alb ratio was reduced in the sarin poisoned patients, it is considered useful for discrimination from liver cirrhosis in which both Ch-E and Alb levels decreased. Amino acid levels in the serum obtained from the sarin poisoned patients were compared with those of healthy individuals, both of which had been stored under the same conditions. There were significant differences in Asp, glutamate (Glu), phenylalanine (Phe), 3-M-His, glutamine (Gln), and Cys levels. The Glu, Phe, and Gln levels were not affected by storage of serum in a frozen state, while the Glu and Phe levels were elevated and the Gln level was reduced. Although Cys exhibited lower values in frozen serum samples, the Cys level was elevated with a rise in the serum Ch-E levels. Therefore, we deduced that Cys metabolism disorders also occur in sarin poisoning. As stated above, the Glu and Phe levels were elevated and the Gln and Cys levels were reduced, suggesting the presence of abnormal amino acid metabolism, in patients with sarin-poisoning.

Adolescent↗
PubMed1996

The inhibition of human factor Xa by plasminogen activator inhibitor type 1 in the presence of calcium ion, and its enhancement by heparin and vitronectin.

Plasminogen activator inhibitor type 1 (PAI-1), a member of serine proteinase inhibitor superfamily, is known to inhibit thrombin in the presence of either heparin or vitronectin. We analyzed possible inhibitory activity of PAI-1 on human factor Xa. PAI-1 inhibited factor Xa in the presence of calcium ion (Ca2+), whereas no inhibition was observed in the absence of Ca2+. Half maximal enhancement by Ca2+ was obtained at 0.8 mM. An equimolar complex formation between factor Xa and PAI-1 in the presence of Ca2+ was observed by SDS polyacrylamide gel electrophoresis. Both unfractionated heparin and vitronectin enhanced the inhibition only in the presence of Ca2+. Apparent second-order rate constant (ki) for the inhibition of factor Xa by PAI-1 at 5 mM Ca2+ was 1.6 x 10(4) M-1 s-1, and was enhanced 3-fold by 2 u/ml of heparin (4.6 x 10(4) M-1 s-1) and 10-fold by 100 nM vitronectin (1.6 x 10(5) M-1 s-1), respectively. The interaction between Ca(2+)-bound factor Xa and PAI-1 could be important from the view of PAI-1 neutralization and enhancement of fibrinolysis.

Calcium↗
PubMed1996

Conformational change in DNA induced by cationic bilayer membranes.

The effect of synthetic cationic lipids on the structure of DNA was studied. The fluorescence enhancement of ethidium bromide on intercalation into DNA was suppressed by the addition of bilayer-forming lipids, but not by micellar ones. Results on the fluorescence depolarization index suggest that ethidium bromide is not released from DNA by lipids intercalated into DNA. CD spectra of the DNA-lipid complexes revealed that the structure of DNA was changed only by bilayer-forming lipids at temperatures lower than their Tc values. Thus, the conformation of DNA is forced to change by cationic lipids forming the rigid bilayer membrane so that ethidium bromide fluorescence might be reduced, and the conformation can be controlled by selection of the appropriate lipid and temperature.

Cations↗
PubMed1996

The significant effect of HLA-DRB1 matching on acute rejection in kidney transplants.

The object of the present study was to confirm the HLA-DRB1 matching effect on rejection crisis, its severity, and kidney graft survival based on genotyping. Ninety-four renal allografts were included in this study. DNA typing of HLA-DRB1 was performed by the polymerase chain reaction sequence-specific oligonucleotide method. The incidence of acute rejection within 6 months following transplantation, the frequency of OKT3 administration for steroid-resistant rejection, histopathological findings, and graft survival rate were compared between the DRB1-matched (n = 23) and DRB1-mismatched (n = 71) groups. Four acute rejections occurred in the DRB1-matched group (incidence; 17%) and 40 in the DRB1-mismatched group (56%). In the DRB1-matched group, the incidence of acute rejection was significantly less frequent than that of the DRB1-mismatched group (P < 0.005). In the DRB1-matched group, only one patient received OKT3 administration (4%), in contrast to 16 of 71 patients in the DRB1-mismatched group (23%). The use of OKT3 was significantly less frequent in the DRB1-matched group (P < 0.05). Histopathological findings from biopsy specimens showed no constant distribution of pathological grades of acute rejection according to DRB1 matching in the present study. The graft survival rate in the two groups did not differ significantly, but the graft survival rate in the DRB1-mismatched group had a tendency to decrease as the grafts survived longer. In conclusion, the results of the present study confirm that HLA-DRB1 matching has marked beneficial effects on kidney transplants through reduction of the acute rejection rate and decrease of the severity of rejection, and suggest that improvement of graft survival will be obtained through kidney allocation to a DRB1-matched recipient.

Acute Disease↗
PubMed1996

Partially-hydrophobized polymer particles derived from N,N-dimethylaminopropylacrylamide for endotoxin removal from acidic protein solution.

Novel copolymeric adsorbents for the selective removal of endotoxin from an acidic protein solution were prepared. The adsorbents comprise spherical copolymers derived from N,N-dimethylaminopropylacrylamide (DMAPAA) and divinylbenzene (DVB). When the molar ratio of DMAPAA to DVB was 80/20 (amino-group content: 5.1 meq/g) and the pore size (molecular mass exclusion of polysaccharide, Mlim) was 4000 to 10000, DMAPAA/DVB showed high endotoxin-adsorbing activity at pH 5.0 to 9.0 and ionic strengths of mu = 0.05 to 0.4. The capacity of the adsorbent (Mlim: 4000) was 390 micrograms of endotoxin (lipopolysaccharide purified from E. coli O111:B4) per ml of the adsorbent using the batchwise method. The apparent dissociation constant between endotoxin and the adsorbent was 2.2 x 10(-12) M. On the other hand, the adsorption of bovine serum albumin, an acidic protein, by the adsorbent increased with an increase in Mlim from 4000 to 10000, but decreased with an increase in ionic strength (mu) from 0.05 to 0.2. As a result, DMAPAA/DVB (80/20) (Mlim: 4000) selectively removed endotoxin from various acidic protein solutions at pH 7.0 and mu = 0.05. The residual concentration of endotoxin in the protein solution always decreased to a concentration lower than 0.1 ng/ml, and recovery of the protein was more than 97%.

Acrylamides↗
PubMed1996

Three extracellular chitinases in suspension-cultured rice cells elicited by N-acetylchitooligosaccharides.

In rice suspension culture, a large part (about 90% of total activity in the culture) of the chitinase activity was found in the medium. Two extracellular chitinases (which we named RCH-A and -B) were separated from the cell suspension by DEAE-cellulofine column chromatography. When cells were treated with N-acetylchitooligosaccharides (chitin oligosaccharides) for 3 days, extracellular chitinase activity increased about 3-fold over the control culture. After the treatment, another extracellular chitinase (named RCH-C) appeared in addition to increases in the levels of RCH-A and -B. Partial amino acid sequences of these enzymes indicated that RCH-A (33.5 kDa) and -B (34 kDa) were class Ib chitinases but RCH-C (27 kDa) was a class III chitinase. RCH-A and -B were capable of actively degrading water-insoluble chitin with high affinities, while RCH-C had less affinity for the substrate. However, when a water-soluble chitin derivative, 6-O-hydroxyethylchitin (glycolchitin) was used, RCH-C as well as RCH-A and -B degraded actively with a high affinity. A synergistic effect was observed when these three chitinases acted simultaneously in the hydrolysis of chitin.

Amino Acid Sequence↗
PubMed1996

[Clinical study of pediatric kidney transplantation at Kansai].

BACKGROUND: The clinical study of pediatric kidney transplantation in Kansai area is reported in this paper. METHODS: Seventy six children, 0-15 years old, received renal transplants at 8 transplant centers of Kansai area up to December, 1993. Clinical study was carried out about the etiology of renal failure causes, the graft survival and the complications. RESULTS: End-stage renal failure was due to a variety of diseases. The 3 most common causes were chronic glomerulonephritis, chronic pyelonephritis including of reflux nephropathy and focal segmental glomerulosclerosis (FSGS). The graft rates at 3, 5 and 8 years were 75%, 71% and 53% for children receiving azathioprine (AZ), compared to 77%, 59% and 52% for ones receiving ciclosporin (Cs). Cs has led no improvement of the graft survival. Adult had the better graft survival rate than children in Cs immunosuppressive protocol. In 12 children transplanted kidneys for FSGS, only 3 cases had recurrent FSGS. Neoplasia was found in two case. They were acute leukemia and liposarcoma. CONCLUSION: Kidney transplantation is recommended as the treatment for end-stage FSGS. Even the children should be carefully followed up after transplantation for malignant tumors.

Adolescent↗