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Y Nakazawa

Publications and source records attributed to Y Nakazawa.

At least 55 records · Page 3Linked to original sources
PubMed1999

Microhardness evaluations of resin-dentin bonding areas by nano-indentation.

The purpose of this experiment was to determine the hardness values of the hybrid layer and its surroundings through the continuous use of a microhardness measuring device. Black's Class V cavities were prepared in nine dog teeth. The cavities were divided into four groups according to the dentin adhesive system applied. The adhesive systems were: "Bond One System", "Liner Bond II sigma System", "One Step System", and "Single Bond System". The treated teeth were observed at seven days post-application. Specimens were cross-sectioned perpendicularly or horizontally to the resin-dentin interface and embedded in epoxy resin. Their surfaces were polished. The microhardness of the resin-dentin bonding area was measured with a nano-indentation tester. The hardness values at a point of 10 microns distant from the interface in the direction of the dentin differed between systems. It appeared that this was influenced by the presence of the decalcified dentin not impregnated by resin, differences in the chemistry forming the hybrid layer, and the composition of the bonding resin. The hardness of the dentin-bonding interface and its surroundings was determined, and these areas were observed using SEM. Three layers were confirmed the healthy dentin layer, the composite resin layer, and the hybrid layer, (in which decalcified dentin impregnated by resin and that not impregnated by resin are considered to be mix). In the hybrid layer, no impression was found by SEM although the hardness in the bonding interface was significantly different. These layers appear to be more elastic and softer than the healthy dentin.

Animals↗
PubMed1999

Platelet glycoprotein Ib: a zinc-dependent binding protein for the heavy chain of high-molecular-weight kininogen.

Domains 3 and 5 of high-molecular-weight kininogen (HK) have been shown to bind to platelets in a zinc-dependent reaction. However, the platelet-binding proteins responsible for this interaction have not been identified. We have focused on the platelet-binding site for the heavy chain (domain 3), which we approached using a domain 3-derived peptide ligand and isolated binding proteins by affinity chromatography. The domain 3-derived peptide, thrombin, HK, factor XII, as well as antibody to glycocalicin (the N-terminal portion of the alpha chain of GPIb) recognized a protein at 74 kD. We also isolated the thrombin receptor (PAR 1) at 45 kD, however, none of the above-mentioned ligands bound to this protein. Isolation of platelet membrane proteins using a monoclonal anti-glycocalicin antibody column revealed the same HK binding protein at 74 kD, which was reactive with anti-GPIb and represents a GPIb fragment. By photoaffinity labeling, HK interacted with membrane GPIb, which was then isolated in native form (135 kD) along with gC1qR, a ligand for the HK light chain. Finally, (125)I-HK binding to platelets was significantly inhibited by the anti-GPIb antibody. These results suggest that the GPIb alpha chain, a known thrombin binding protein, is also one of the zinc-dependent platelet membrane binding sites for HK domain 3.

Antibodies↗
PubMed1998

Relationship between in vivo FK506 clearance and in vitro 13-demethylation activity in living-related liver transplantation.

BACKGROUND: Although it is important to maintain an appropriate blood concentration of FK506 after liver transplantation, significant interindividual variability in the actual FK506 dosage has been observed, presumably due to the wide variability of cytochrome P450 3A4 activity in liver microsomes. METHODS: A study was conducted in patients undergoing living-related liver transplantation and their donors to investigate the relationship between the in vitro FK506 demethylation activity in graft liver microsomes and the in vivo blood clearance of FK506. Liver biopsy tissue was obtained from 17 living donors to measure the in vitro formation rate of 13-demethyl derivative (M-I: the major metabolite of FK506). Erythromycin N-demethylation activity in vitro was also assessed in 11 cases. The FK506 blood clearance (CLss) was calculated from its constant infusion rate and steady-state blood concentration on day 4 after transplantation in 17 recipients. RESULTS: The FK506 infusion rate varied 4.6-fold from 8.3 to 38.4 ng/min/kg. The mean CLss of FK506 was 22.1+/-10.8 ml/min (10.1-45.2 ml/min). The M-I formation rate showed a wide variability, ranging from 0.098 to 0.571 nmol/min/mg protein. A significant correlation was observed between the in vitro estimated total metabolic ability of the graft for FK506 (M-I formation rate x graft weight) and the in vivo CLss of FK506 (r=0.770, P<0.001). Erythromycin N-demethylation (0.066-0.443 nmol/min/mg protein) showed a strong correlation with the M-I formation rate (r=0.891, P<0.01). CONCLUSIONS: The in vivo FK506 clearance can mainly reflect in vitro FK506 demethylation activity.

Adolescent↗
PubMed1998

Immunochemical quantification of crossline as a fluorescent advanced glycation endproduct in erythrocyte membrane proteins from diabetic patients with or without retinopathy.

Crossline is a novel advanced glycation endproduct (AGE) which has both a crosslink and fluorescence similar to AGE-protein in vivo. To assess the association of AGEs to the development of diabetic retinopathy we developed a sensitive and specific enzyme-linked immunosorbent assay (ELISA) for crossline in blood samples and investigated the association of the development of retinopathy and erythrocyte membrane protein (EMP)-crossline concentrations in patients with Type 2 diabetes mellitus (Type 2 DM). Crossline formation in EMP exceeded that in haemoglobin and was detectable in normal EMP samples without pretreatment by this ELISA system. Mean (+/-SE) EMP crossline levels were elevated 1.6-fold in diabetic patients without retinopathy (7.6 +/- 0.5 pmol mg(-1), p < 0.005), 2.2-fold in diabetic patients with non-proliferative retinopathy (10.5 +/- 0.6 pmol mg(-1), p < 0.001) and 2.6-fold in diabetic patients with proliferative retinopathy (12.0 +/- 0.6 pmol mg(-1), p < 0.001) compared with healthy control subjects (4.7 +/- 0.5 pmol mg(-1)). Type 2 DM patients with retinopathy had significantly higher EMP-crossline levels than those without retinopathy (p < 0.005). Our data suggest that elevated EMP-crossline concentrations are associated with the presence of retinopathy in patients with Type 2 DM and EMP-crossline measured by our ELISA may provide a useful marker for assessing the role of glycation in the development of diabetic retinopathy.

Aged↗
PubMed1998

Living related liver transplantation in adults.

OBJECTIVE: To evaluate the outcome of living related liver transplantation (LRLT) in adult patients and to assess graft size disparity and graft regeneration. SUMMARY BACKGROUND DATA: Although LRLT has been accepted as an optional life-saving procedure for pediatric patients with end-stage liver disease, the feasibility of LRLT for adult patients has not been reported with reference to a clinical series. METHODS: Adult-to-adult LRLT was performed using whole left lobar grafts in 13 patients (5 with primary biliary cirrhosis, 6 with familial amyloid polyneuropathy, 1 with biliary atresia, and 1 with citrullinemia). The 13 donors comprised 5 husbands, 3 sons, 2 sisters, 2 fathers, and 1 mother. The ratio of the graft volume to standard liver volume (GV/SV ratio) was calculated for use as a parameter of graft size disparity. RESULTS: Although the liver graft was markedly small for size (GV/SV ratio 32%-59% at the time of LRLT), none of the 13 patients developed postoperative liver failure. Eleven of the patients are still alive and well with satisfactory graft function 2 to 35 months after LRLT. Graft liver volume increased rapidly after LRLT and approximated the standard liver volume with time. CONCLUSIONS: Our LRLT program for adult patients has produced good results. LRLT in adults can be indicated for selected donor-recipient combinations.

Adult↗
PubMed1998

Efficacy of L-846 in patients with insomnia: evaluation by polysomnography.

The effects of L-846, an ultra-short-acting pyrazolopyrimidine hypnotic, on sleep were studied in nine insomniacs and two neurotic patients with insomnia. The patients were randomly assigned to receive 5 mg (n=6) or 10 mg (n=5) L-846. The study schedule comprised of one adaptation night, two baseline nights, three drug nights, and two withdrawal nights. Sleep latency and slow wave sleep (SWS) latency was largely shortened and %SWS increased in the early phase of sleep. No clear evidence of rebound insomnia was noted.

Acetamides↗
PubMed1998

[A clinical investigation of bacteremia for the past ten years at the Second Department of Internal Medicine, Jikei University Hospital].

We clinically investigated a total of 288 cases of bacteremia for the past ten years, from January 1986 to December 1995, at the Second Department of Internal Medicine in the jikei University Hospital. All of the subjects who had a positive reaction to blood culture or catheter tip culture were investigated for their basic disease, complications, and detected bacteria. Malignant tumors, chronic renal failure, diabetes mellitus, and hematologic disease were frequent by noted. The cases due to primary infection were mainly respiratory organ infection or urinary tract infection, which were 47.8% of the total. In 31.3% of the total, catheter tip cultures were positive. Except for catheter related infection, Gram-positive coccus were detected in 40.3%, which was most frequent. Methicillin resistant Staphylococcus aureus (MRSA) were 8.1% and Staphylococcus epidermidis were 11.2%. In catheter related infection, Gram-positive coccus were detected in 59.9%, which was most frequent amongst them, MRSA was 17.2%, S. epidermidis was 16.2%. The mortality of bacteremia was 12.5%, mainly from hematologic diseases, immunodeficiency due to long term steroid administration etc. Accordingly, the more the advance of chemotherapy, the better the prognosis of septicemia is. Appearance of catheter related infection was unexpected frequent. Increase of immunocompromised host is thought to be one of the main factors in the outbreak of bacteremia.

Adolescent↗
PubMed1998

[An analysis of sclerodermatous graft-versus-host-disease after allogeneic bone marrow transplantation: CD8+CD57+T-cell proliferation and increased production of TGF-beta].

A 19-year-old woman with acute lymphoblastic leukemia received an allogeneic bone marrow transplantation (BMT) from an HLA-identical sibling during the second remission, on September 28, 1993. The conditioning regimen consisted of total body irradiation and cyclophosphamide. Short term methotrexate and cyclosporin A were given for prophylaxis of graft-versus-host disease (GVHD). On day 771 after BMT, she complained of bilateral forearm pain, and developed sclerotic lesions on the skin of the abdominal wall, forearms and legs. The diagnosis of sclerodermatous GVHD was established by skin biopsy on day 834. The values of CRP and IgG were elevated, and both antinuclear antibody and anti-DNA antibody became positive. Flow cytometric analysis showed a significant increase in the number of CD57+ cells after appearance of sclerotic change. In addition, 65% of CD8+ cells were positive for CD57. Circulating level of transforming growth factor (TGF)-beta 1 was high. These results suggest that overproduction of CD8+ CD57+ T cells and high level of circulating TGF-beta are related to the development of sclerodermatous GVHD.

Adult↗
PubMed1997

Urgent living-related liver transplantation using a graft with multiple intrahepatic arterioportal fistulae.

BACKGROUND: We describe the case of a man with intrahepatic arterioportal fistulae located in the left lobe, whose left lateral segment was transplanted into his son who was suffering from severe acute hepatitis B. METHODS: A male infant with severe acute hepatitis B was considered to be a candidate for liver transplantation. The father was willing to be the donor. Preoperative evaluation of the donor revealed intrahepatic arterioportal fistulae, however, duplex ultrasonography showed normograde portal blood flow. A living-related liver transplantation was performed. RESULTS: The postoperative course for both the donor and recipient was uneventful. The recipient is free of recurrent hepatitis B and has normograde portal blood flow. CONCLUSIONS: The present case suggests that there may be a symptomless population with intrahepatic arterioportal fistulae, which cause various degrees of disruption of the portal blood flow. Duplex ultrasonography might be helpful in the evaluation of candidates for liver donation.

Adult↗
PubMed1997

Efficacy of quantitative analysis of Epstein-Barr virus-infected peripheral blood lymphocytes by in situ hybridization of EBER1 after living-related liver transplantation: a case report.

BACKGROUND: We describe a 1-year-old female who underwent living-related liver transplantation for biliary atresia and developed Epstein-Barr virus (EBV)-related posttransplant lymphoproliferative disorder. This disorder was resolved after withdrawal of immunosuppression therapy and administration of a high dose of acyclovir. METHODS: To quantify the extent of EBV activation and EBV load in peripheral blood, we measured the levels of EBV-infected peripheral lymphocytes by in situ hybridization (ISH) of EBV-encoded small mRNA 1 (EBER1). RESULTS: The decline in the number of EBER1-positive lymphocytes (from 362/50,000 mononuclear cells to 0/50,000) after treatment was in accord with the patient's clinical improvement. CONCLUSIONS: This finding showed that quantitative analysis of EBV-infected peripheral lymphocytes by ISH of EBER1 is very useful for monitoring the EBV load and response to treatment of patients with EBV-related disorders. Furthermore, ISH may become an important tool for the early diagnosis and prevention of life-threatening posttransplant lymphoproliferative disorder in posttransplant patients.

Acyclovir↗
PubMed1997

Acid-stable fluorescent advanced glycation end products: vesperlysines A, B, and C are formed as crosslinked products in the Maillard reaction between lysine or proteins with glucose.

Vesperlysines A and B, 6-hydroxy-1,4-di{6-(L-norleucyl)}-1H-pyrrolo[3,2-b]pyridinium and its 5-methyl derivative, respectively, and Vesperlysine C, 5-hydroxy-methyl-1,6-di{6-(L-norleucyl)}-1H-pyrrolo[3,4-b] pyridinium, are isolated as major fluorescent advanced glycation end products (AGEs) from hydrochloric acid hydrolysis of AGE-BSA, bovine serum albumin (BSA) modified by the Maillard reaction with glucose. These fluorophores are glycation products and not artifacts of hydrolysis, since they are also detected in the reaction mixture of lysine and glucose prior to hydrolysis. Vesperlysines are crosslinked products from two lysine side-chains in proteins and are considered to be generated from lysines and the oxidative degradation of glucose, because the six carbon skeleton of glucose in its original form was not incorporated into each structure. These compounds are most likely glycoxidation products like pentosidine. This reasoning is supported by the formation of the same compounds in the Maillard reactions in which ascorbic acid or other sugars with shorter carbon chains are used.

Chromatography, High Pressure Liquid↗
PubMed1997

Antimutagenicity of Tochu tea (an aqueous extract of Eucommia ulmoides leaves): 1. The clastogen-suppressing effects of Tochu tea in CHO cells and mice.

The suppressing effect of crude extracts of Tochu tea, an aqueous extract of Eucommia ulmoides leaves and a popular beverage in Japan, on the induction of chromosome aberrations in CHO cells and mice was studied. When CHO cells were treated with Tochu tea crude extract after MMC treatment, the frequency of chromosome aberrations was reduced. Out of 17 Tochu tea components, 5 irridoids (geniposidic acid, geniposide, asperulosidic acid, deacetyl asperulosidic acid, and asperuloside) and 3 phenols (pyrogallol, protocatechuic acid, and p-trans-coumaric acid) were found to have anticlastogenic activity. Since the anticlastogenic irridoids had an alpha-unsaturated carbonyl group, this structure was considered to play an important role in the anticlastogenicity. The anticlastogenic effect of Tochu tea extracts was examined in mice using a micronucleus assay. When mice received 1.0 ml 4% Tochu tea extract by oral gavage 6 h before intraperitoneal injection of MMC, a decrease in the frequency of micronuclei was observed. This decrease was not due to a delay in the maturation of micronucleated reticulocytes.

Animals↗
PubMed1997

Hepatic artery reconstruction in living donor liver transplantation from the microsurgeon's point of view.

Microvascular surgery for the reconstruction of the hepatic artery in living donor liver transplantation is discussed from the microsurgeon's point of view. A refined operative procedure to improve the safety of the anastomosis is described. In living donor liver transplantation, the hepatic artery of the graft is short and small, the operative site is deep and mobile, and the anatomic arrangement of the graft left hepatic artery may differ from that of the recipient's dilated hepatic artery. To create a safe anastomosis under these conditions, recipient arteries that were slightly smaller than the graft artery were dissected. Without the size discrepancy, and end-to-end anastomosis could be created. Some refinements to create a good operative field made the anastomosis easy. The apparatus and techniques used in free-flap transfer facilitated a clean anastomosis. We anastomosed 44 arteries in 40 patients undergoing living donor liver transplantation using microsurgical techniques. Neither a decrease in the arterial blood flow nor hepatic artery thrombosis was noted. The refined operative procedure we describe in this report can be used to overcome the problems associated with the hepatic artery anastomosis in living donor liver transplantation.

Adolescent↗