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Biomedical subjects

J Hayashi

Publications and source records attributed to J Hayashi.

At least 181 records · Page 10Linked to original sources
PubMed1997

Prevalence of liver abnormalities in the general population of Okinawa, Japan.

A total of 2,825 Japanese over 20 years of age living in the Yaeyama District of Okinawa, Japan were investigated in 1983 and 1984 to determine the prevalence and risk factors of liver abnormalities. Obesity index, hepatitis B virus markers, hepatitis C virus marker and serum transaminase were measured and the history of alcohol intake was recorded. People with elevated transaminase levels were assumed to have abnormalities of the liver. The overall prevalence of liver abnormalities was 3.6% and was significantly higher in men than in women (p < 0.001). Logistic regression analysis showed that the strongest predictors of liver abnormalities were alcohol for the men and obesity for the women. Hepatitis B virus was the second most prevalent risk factor in both sexes.

Adult↗
PubMed1997

Large dose natural interferon alpha therapy for patients with chronic hepatitis C.

To evaluate the efficacy of large dose interferon treatment for patients with chronic hepatitis C virus (HCV) infection, we studied 99 Japanese patients treated with either 6 million units (MU) or 9 MU natural interferon alpha. Serum samples were tested for HCV RNA by polymerase chain reaction (PCR). HCV RNA genotypes were determined by PCR with type-specific preimers, and the HCV RNA level was measured by competitive PCR. HCV RNA was detected in all patients, prior to the initiation of treatment. We examined interleukin-1 receptor antagonist (IL-1 Ra) by enzyme-linked immunosorbent assay. Forty-four patients were treated with 9 MU natural interferon alpha for 24 weeks (group A), and fifty-five patients were treated with 6 MU natural interferon alpha for 24 weeks (group B). There were no significant differences in HCV RNA levels, HCV RNA genotype or histological activity index (HAI) score between the two groups. Of the 94 patients who completed this treatment, nine (23.1%) in group A and 14 (25.5%) in group B sustained elimination of HCV RNA throughout a 6-month follow-up. There were no differences in the rate of complete response when comparing HCV RNA genotype, levels and HAI score and no significant differences in elevation of IL-1 Ra levels between the two groups. Five of group A patients refused further treatment because of severe side effects such as retinal hemorrhage, while no patient in group B had severe side effects. Thus, large dose natural interferon alpha treatment confers no additional benefit to the patient, compared with the current use of a lower dose.

Adult↗
PubMed1996

Preparation of primary cultures and acute slices of the nervous system of the moth Manduca sexta.

Interactions among receptor neurons, glial cells and neurons intrinsic to the antennal lobe of the moth underlie the formation of olfactory glomeruli. To isolate these interactions, as well as to understand the effect of a variety of humoral agents on differentiation of the neurons and glia, we generate primary cultures of neurons or glia. These methods are described. In addition. we describe a protocol for producing slice preparations of the developing moth brain that we are using to study the biophysical and morphological development of glial cells. This technique allows us to examine a class of glial cells associated with the glomeruli that otherwise are nearly inaccessible using standard intracellular recording techniques. It also preserves the 3-dimensional arrangement of glia that may strongly influence the development of glomeruli.

Animals↗
PubMed1996

Mutant mtDNA at 1555 A to G in 12S rRNA gene and hypersusceptibility of mitochondrial translation to streptomycin can be co-transferred to rho 0 HeLa cells.

Human skin fibroblast line 95-119, which had been isolated from the mother of a Japanese patient with aminoglycoside-induced deafness and a 1555 A to G mutation at 12S rRNA gene in mitochondrial DNA (mtDNA), was used to investigate the relationship between the 1555 mtDNA mutation and its pathogenicity. By the intercellular transfer of mtDNA with or without the 1555 mutation to mtDNA-less (rho 0) HeLa cells, we isolated cybrid clones and found that the mitochondrial translation in a cybrid clone repopulated with the homoplasmic 1555 mutation showed the highest susceptibility to streptomycin. These observations suggest that the genotype of the mutant mtDNA and the phenotype of hypersusceptibility to streptomycin observed in 95-119 fibroblasts were co-transferred simultaneously to rho 0 HeLa cells, supporting the idea that the homoplasmic 1555 mtDNA mutation is involved in the pathogenesis leading to aminoglycoside-induced hearing loss.

Aminoglycosides↗
PubMed1996

Surgical implication of aortic dissection on long-term outcome in Marfan patients.

We herein review our 17-year surgical experience for the treatment of ascending aortic aneurysm in patients with Marfan syndrome to clarify the risks of increased mortality and reoperation. The subjects consisted of 15 patients who had all undergone surgery for the aortic root and ascending aorta at Niigata University Hospital between July 1978 and January 1995. Aortic valve replacement and ascending aortic wrapping were performed in 5 patients, Bentall or Cabrol operation in 6, and combined aortic arch reconstruction and Cabrol operation in 2, as the initial surgery. Patients who had an aortic dissection (Stanford type A) at initial surgery were assigned to group I (n = 7), while those with an aortic root aneurysm were assigned to group II (n = 8). In group I, 3 patients required a second operation for the remaining aortic arch aneurysm, and 1 died due to a late rupture of the distal aneurysm. In group II, no patient needed a reoperation; however, 1 died due to an intracranial hemorrhage and another due to composite valve graft failure and distal dissection. The results thus indicate that aortic dissection seems to affect long-term outcome, and therefore the combined repair of the aortic root and transverse arch is recommended in Marfan patients with aortic dissection involving the transverse aortic arch.

Adolescent↗
PubMed1996

IL-1 beta and TNF-alpha produced by peripheral blood mononuclear cells before and during interferon therapy in patients with chronic hepatitis C.

We investigated the spontaneous and phytohemagglutinin-stimulated production of interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) by peripheral blood mononuclear cells in patients with chronic hepatitis C during treatment with interferon-alpha (IFN-alpha). Spontaneous productions of these were significantly higher in patients with chronic hepatitis C than in healthy subjects. For patients prescribed interferon, stimulated production of TNF-alpha was significantly higher in complete responders than in partial responders, but the differences were small between the other cytokine levels and outcome of IFN treatment. Spontaneous production of these cytokines was higher in patients with genotype III with complete response than in genotype III patients with a partial response, but this was not the case in patients with genotype II. There was a negative correlation between these cytokines and histological activity index. Spontaneous production of cytokines was decreased only in complete responders after the administration of interferon. These data suggest that the elevated production of cytokines in patients with chronic hepatitis C may be due to host response to the virus, and monitoring cytokines along with alanine aminotransferase and hepatitis C virus RNA during treatment may provide more precise information of the effectiveness of therapy.

Adult↗
PubMed1996

Evaluation of quantitative assay for antibody to hepatitis C virus core in patients treated with interferon.

We titrated antibody to hepatitis C virus (anti-HCV) core of serum samples from 57 patients with chronic HCV infection, in an attempt to clarify the relationship between the level of HCV RNA and the outcome of interferon treatment. The patients studied were positive for both anti-HCV, by second-generation assay, and HCV RNA, by polymerase chain reaction, and had been treated with interferon for six months. Of the 57 patients, HCV RNA was eliminated in 16 by the time of discontinuation of interferon treatment (CR); in 19 this elimination was transient (PR) and for 22 elimination was nil (NR). The low HCV RNA level was accompanied by high titers of anti-HCV core while high HCV RNA levels were accompanied by low titers of anti-HCV core, with an inverse correlation (r = -0.322, P < 0.05). The mean titer of anti-HCV core before interferon treatment was 324 units in CR, 205 in PR, and 168 in NR, with a correlation ratio of 0.382 (P < 0.05). A decreased titer (more than 50%) was found in 68% of the CR. At the time of six-month follow-up, the anti-HCV core titers of CR had decreased by more than 50%, compared to pretreatment titers, while in PR and NR, there was an increase to above the pretreatment titers, without increases in HCV RNA levels or worsening of the hepatitis. In conclusion, quantitative assay for anti-HCV core is useful to assess the status of HCV replication.

Adult↗
PubMed1996

Prevalence of hepatitis C virus infection among female prostitutes in Fukuoka, Japan.

To assess the risk of sexual transmission of hepatitis C virus (HCV), we surveyed female prostitutes to determine the prevalence of antibody to HCV (anti-HCV) and HCV RNA. Anti-HCV was examined with a second generation anti-HCV test employing a passive hemagglutination assay. HCV RNA was detected by two-stage polymerase chain reaction with primers deduced from the 5'-noncoding region of the HCV genome. All studies were performed in Fukuoka, Japan, from 1989 through 1992 and all subjects were Japanese and had no history of intravenous drug abuse. The prevalence of anti-HCV was significantly higher in the prostitutes (10.1%; 61/604) than in the controls (female blood donors; 0.8%; 52/6632) (P < 0.001). HCV RNA was found in 73.2% of the anti-HCV-positive prostitutes. The prevalence of anti-HCV among prostitutes increased with the number of years spent in prostitution (P < 0.05). Prostitutes with a history of syphilis had a higher prevalence of anti-HCV than those with no history of syphilis, irrespective of the number of years in prostitution. In a longitudinal study of 244 prostitutes, 2 of the 218 initially seronegative subjects showed anti-HCV and HCV RNA over the study period of 3 years. These two persons had no history of percutaneous exposure. Sexual transmission of HCV presents a risk for female prostitutes.

Adolescent↗
PubMed1996

Fringed valve prosthesis for aortic root abscess.

Two patients with aortic root abscess were successfully treated with a fringed valve prosthesis, in which a fringe material was secured to the sewing cuff of a bileaflet prosthetic valve using a 4-0 running suture. This fringed valve technique provides dual security for annular attachment of the prosthesis without coronary reimplantation. Good late outcome suggests it would be a useful alternative for aortic root abscess.

Abscess↗
PubMed1996

Histologic findings of long-term cryolesions in a patient with ventricular tachycardia.

This report describes cardiac morphologic alterations in a patient who died 14 months following cryoablation. Histologic examination of the long-term cryolesion revealed a homogeneous fibrous scar with surrounding sinusoid capillary proliferation. The border between the fibrosis and the normal myocardium was sharply defined. Cryothermia is an excellent technique for the surgical correction of arrhythmias because it provides sharply demarcated lesions which lack arrhythmogenic potential.

Bundle-Branch Block↗
PubMed1996

Long-term outcome of patients who received Starr-Edwards valves between 1965 and 1977.

To determine the risk factors relating to long-term outcomes of the Starr-Edwards ball valve, data from 150 patients (75 males, 75 females; age range 9-67 years); who underwent valve replacement (44 aortic, 106 mitral) between 1965 and 1977 at Niigata University were reviewed retrospectively. Valve models 6120/6320 and 1260/2320 were mainly used in mitral and aortic positions, respectively. The cumulative follow-up period was 2227.4 patient-years. Using the Kaplan-Meier life-table method, actuarial probability of freedom from valve-related mortality, morbidity and thromboembolism were analysed. Thirteen patients died from various causes during hospitalization. Some 80 patients suffered 97 instances of valve-related morbidity and 58 died during follow-up (up to 28 years). Patient age > 50 years affected the actuarial probability of freedom from valve-related mortality in the entire group (P < 0.05). Valve type and the year of operation were discriminative predictors of thromboembolic complications in the entire group (both P < 0.05) and in the mitral valve replacement group (P < 0.01 and P < 0.001). However, only the year of operation affected the actuarial probability of freedom from all valve-related morbidity in the entire group and in the mitral valve replacement group (both P < 0.05). Univariate analysis revealed that age at surgery, valve type, and the year of operation were related to late postoperative outcome in patients who received a Starr-Edwards ball valve between 1965 and 1977.

Actuarial Analysis↗
PubMed1996

A comparative study of the effect of autologous platelet-rich plasma and fresh autologous whole blood on haemostasis after cardiac surgery.

The effects of fresh autologous platelet-rich plasma and autologous whole blood on haemostasis after cardiopulmonary bypass were examined in adult cardiac surgery patients. Platelet count, adenosine diphosphate 10 microM maximum aggregation rate and clotting Factor VIII were greater in the platelet-rich plasma group (n = 11) than in the whole blood group (n = 8) after platelet-rich plasma or whole blood reinfusion. Blood loss after heparin neutralization was less in the platelet-rich plasma group than in the whole blood group. Blood loss from heparin neutralization to 12h after surgery was correlated with platelet count, fibrinogen and ADP aggregation rate. The number of patients who required homologous blood transfusion was less in the platelet-rich plasma group. In conclusion, the reinfusion of autologous platelet-rich plasma improves haemostasis after cardiopulmonary bypass, and may enable surgery to be performed without homologous blood transfusion.

Adenosine Diphosphate↗
PubMed1996

Is a bioprosthesis preferable in tricuspid valve replacement?

We reviewed clinical data on 29 patients (17 acquired disease and 12 congenital disease) who underwent tricuspid valve replacement using a Carpentier-Edwards porcine valve or a St. Jude Medical valve at Niigata University Hospital between January 1978 and October 1995, and analyzed risks related to the outcome. Age ranged from 8 to 62 years, and 17 females were included. New York Heart Association functional class was IV in 9 patients (31%). Previous valve surgery had been performed in 10 patients (34%). An urgent surgery was required in 4 patients and simultaneous mitral (with aortic) valve replacement in 13 (45%). Mean follow-up period was 6.7 years. Hospital mortality occurred in 5 patients (17.2%) and all of them had acquired valvular diseases with functional class IV. There were 6 late deaths and none of them related to the tricuspid prosthesis. Nonfatal morbidity occurred in 2 patients (a thrombosed valve and a chronic hemolytic anemia) with a St. Jude valve. Late functional class was I or II in all patients except 3 with severe left-ventricular dysfunction or bioprosthetic failure. Late postoperative echocardiographic examination showed moderate tricuspid stenosis or regurgitation in 3 patients with a Carpentier-Edwards valve. By the Kaplan-Meier method, functional class (P < 0.01) and baseline diseases (p < 0.05) were found to affect probability of freedom from cardiac- and/or valve-related mortality including hospital death. In conclusion, the present study indicates that similarly good outcome would be expected whether using a St. Jude Medical valve or a Carpentier-Edwards porcine valve, and that both functional class IV and combined acquired valvular disease are risk factors for mortality after tricuspid valve replacement. Patient-specific selection of the prosthesis would be preferable in tricuspid valve replacement.

Adolescent↗
PubMed1996

Scanning electron microscopic analysis of acute photodynamic therapy for atherosclerotic plaques of rabbit aorta by using a pheophorbide derivative.

The aim of this study was to demonstrate acute efficacy of photodynamic therapy on atheromas by using a pheophorbide derivative, PH-1126. Cholesterol-fed atherosclerotic rabbits were injected intravenously with 1 mg/kg of PH-1126. Twenty-four hours later, PH-1126 selectively accumulated in atherosclerotic plaques. Then, atherosclerotic lesions in the upper thoracic aorta were treated by irradiation with a krypton ion laser at a wave-length of 647 nm. At 6 h after photodynamic therapy, the treated aorta was examined by scanning electron microscopy. Numerous teardrop-shaped cells were observed on the endothelial surface of the plaque irradiated at a total energy of 100 J/cm2. These cells were larger than monocytes and macrophages, and resembled foam cells in size and shape. The body of the teardrop-shaped cell resembled pumice stone, mainly because of the presence of globular elements in the cytoplasm. A part of the cell appeared to remain in the subendothelial space. These findings suggest that the cells may be foam cells from the intimal layer of atherosclerotic plaque that were expelled into the aortic lumen. It may become possible to flatten atheroma in a long-term period after photodynamic therapy using PH-1126 as a potent photosensitizer.

Animals↗
PubMed1996

Expression of the apoptosis-mediator Fas is enhanced by dysfunctional mitochondria.

We applied an antibody against an apoptosis mediator, Fas/APO-1/CD95, to HeLa-derived cells that completely lack mitochondrial DNA (mtDNA) or have mutant mtDNAs. The anti-Fas antibody killed the cells completely lacking mtDNA (EB8), at concentrations as low as 1 ng/ml, but not control cells harboring wild-type mtDNA (Ft2-11). TUNEL (terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end-labeling) and analysis of fragmented DNA indicated that the cell death of EB8 was due to apoptosis. The antibody was cytotoxic to other two cell lines harboring mutant mtDNA with a point mutation or a large-scale deletion. RT-PCR (reverse transcriptase-polymerase chain reaction) showed that the mRNA content of the Fas gene was 2 to 19-fold higher in the cells with deficient mtDNA than in the control cells. In addition, the expressed Fas protein was detected by immunohistochemical staining in the cells without mtDNA but not in the control cells. Incubating the cells containing wild-type mtDNA with the respiratory inhibitors rotenone and antimycin A enhanced the content of mRNA of the Fas gene 2 to 4-fold and sensitized cells to the antibody. Thus, defects in mitochondria caused apoptotic cell death by anti-Fas antibody and enhanced Fas gene expression.

Antimycin A↗
PubMed1996

Effect of beraprost, a stable prostacyclin analogue, on red blood cell deformability impairment in the presence of hypercholesterolemia in rabbits.

We evaluated the effects of orally administered beraprost, a stable prostacyclin analogue, on the rheological behavior of red blood cells (RBC) in the presence of hypercholesterolemia. Rabbits fed a cholesterolrich diet were administered various doses of beraprost or pravastatin. We evaluated rheological behavior of RBC by assessing RBC deformability, using a positive-pressure filtration method. The maximum pressure generated by passing a suspension of RBC through a membrane filter was used as an index of RBC deformability. After animals were fed cholesterol for 16 weeks, the maximum pressure increased significantly from 172 +/- 15 mm Hg at baseline to 261 +/- 18 mm Hg (p < 0.01, n = 24). The reduction in RBC deformability associated with hypercholesterolemia improved dose dependently during 1-h incubation with various doses of beraprost. In ex vivo study, beraprost markedly restored RBC deformability 3 h after its oral administration to 218 +/- 17 mm Hg (n = 9) at a low dose and to 215 +/- 20 mm Hg (n = 9) at a high dose. The effect persisted for at least 2 h. Pravastatin failed to reduce the increased maximum pressure. Findings suggest that beraprost treatment may improve the microcirculation by restoring RBC deformability in the presence of hypercholesterolemia.

Animals↗
PubMed1996

Therapeutic effects of continuous intraarterial antibiotic infusion in preventing pancreatic infection in experimental acute necrotizing pancreatitis.

To determine the efficacy of antibiotics in the prevention of pancreatic infection and the process of aggravation after induction of acute pancreatitis, antibiotic was administrated intravenously or intraarterially, starting 6 h after acute pancreatitis was induced in dogs by injecting autologous gallbladder bile into the main pancreatic duct. Flomoxef, recognized as an antibiotic able to penetrate well into pancreas tissue, was selected for the present study. Animals were divided into three groups: no antibiotic given (Group A), antibiotic given intravenously as a bolus injection of 25 mg/kg every 6 h (Group B), and antibiotic infused continuously into the celiac trunk (4 mg/kg/h) (Group C). Compared with Group A, continuous intraarterial infusion of antibiotic (Group C) significantly improved the survival rate and decreased the serum levels of phospholipase A2(PLA2) activity and endotoxin. Furthermore, it completely prevented the occurrence of pancreatic infection, not only ameliorating the severity of pancreatic necrosis but also reducing the activity levels of amidase, trypsin-like enzyme, and PLA2 in pancreas tissue. Group B showed little beneficial effect. Antibiotic concentration in peripheral blood and pancreas tissue was significantly higher in Group C than in Group B. These results suggest that continuous arterial infusion of antibiotics into the feeding artery of the pancreas is an effective modality for preventing pancreatic infection and aggravation of severe acute pancreatitis.

Amidohydrolases↗