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Biomedical subjects

J Hayashi

Publications and source records attributed to J Hayashi.

At least 127 records · Page 7Linked to original sources
PubMed1998

Identification of Cannabis pollens using an allergic patient's immunoglobulin E and purification and characterization of allergens in Cannabis pollens.

Cannabis pollen allergens were detected using the serum of an allergic patient. The allergens were then purified by sequential column chromatography (including DE52 cellulose and phenyl-Sepharose CL-4B) and preparative HPLC. The molecular weight of the allergens were determined as 10,050 and 13,706 by matrix-assisted laser desorption/ionization time of flight mass spectrometry. We utilised Western blotting and development of an enzyme-linked immunosorbent assay for the detection of Cannabis pollen allergens.

Allergens↗
PubMed1998

Regulation of arachidonic acid release and prostaglandin E2 production in thymic epithelial cells by ATPgammaS and transforming growth factor-alpha.

The arachidonic acid metabolites produced by thymic epithelial cells play a pivotal role in thymocyte development. We have discovered that ATP and TGF-alpha regulate the arachidonic acid metabolism in TEA3A1 rat thymic epithelial cells by activating phospholipase A2 enzymatic activity. Our present study demonstrates that ATP and its nonhydrolyzable analog ATPgammaS stimulate both prostaglandin E2 production and Ca2+ influx in TEA3A1 cells. The stimulation of prostaglandin E2 production and Ca2+ influx by ATP is inhibited by pertussis toxin treatment, indicating that ATP mediates its effect by binding to a G-protein-coupled purinergic receptor. Treatment of cells with ATPgammaS and transforming growth factor-alpha results in a synergistic activation of phospholipase A2 and stimulation of prostaglandin E2 production. Results from experiments using an inhibitor of receptor-mediated Ca2+ influx indicate that the synergistic stimulation of prostaglandin E2 production by ATPgammaS and transforming growth factor-alpha requires ATPgammaS-mediated Ca2+ influx. The inhibitor of tyrosine kinase genistein also blocked both ATPgammaS- and ATPgammaS plus transforming growth factor-alpha-mediated stimulation of prostaglandin E2 production, indicating that the activation of phospholipase A2 may involve a protein tyrosine phosphorylation step.

Adenosine Triphosphate↗
PubMed1998

Ethidium bromide-induced inhibition of mitochondrial gene transcription suppresses glucose-stimulated insulin release in the mouse pancreatic beta-cell line betaHC9.

Recently, a mitochondrial mutation was found to be associated with maternally inherited diabetes mellitus (Kadowaki, T., Kadowaki, H., Mori, Y., Tobe, K., Sakuta, R., Suzuki, Y., Tanabe, Y, Sakura, H., Awata, T., Goto, Y., Hayakawa, T., Matsuoka, K., Kawamori, R., Kamada, T., Horai, S., Nonaka, I., Hagura, R., Akanuma, Y., and Yazaki, Y. (1994) N. Engl. J. Med. 330, 962-968). In order to elucidate its etiology, we have investigated the involvement of mitochondrial function in insulin secretion. Culture of the pancreatic beta-cell line, betaHC9, with low dose ethidium bromide (EB) (0.4 microg/ml) for 2-6 days resulted in a substantial decrease in the transcription level of mitochondrial DNA (to 10-20% of the control cells) without changing its copy number, whereas the transcription of nuclear genes was grossly unaffected. Electron microscopic analysis revealed that treatment by EB caused morphological changes only in mitochondria and not in other organelles such as nuclei, endoplasmic reticula, Golgi bodies, or secretory granules. When the cells were treated with EB for 6 days, glucose (20 mM) could no longer stimulate insulin secretion, while glibenclamide (1 microM) still did. When EB was removed after 3- or 6-day treatment, mitochondrial gene transcription recovered within 2 days, and the profiles of insulin secretion returned to normal within 7 days. Studies with fura-2 indicated that in EB-treated cells, glucose (20 mM) failed to increase intracellular Ca2+, while the effect of glibenclamide (1 microM) was maintained. Our system provides a unique way to investigate the relationship between mitochondrial function and insulin secretion.

Animals↗
PubMed1998

Long-term postmortem survival of mitochondrial genomes in mouse synaptosomes and their rescue in a mitochondrial DNA-less mouse cell line.

Mitochondrial DNA (mtDNA) transfer was carried out from postmortem mouse tissues to mouse mtDNA-less (rho0) cells to determine how long it takes for autolysis of mtDNA after death and whether mtDNA in postmortem tissues can recover its function in rho0 cells. The results showed that mtDNA was stable in postmitotic tissues stored at 4 degreesC. Moreover, mtDNA in postmortem brain tissues stored for up to 1 month still retained functional properties, causing complete recovery of mitochondrial respiratory function, when it was transferred to rho0 cells. These observations suggest that mtDNA in brain tissue can survive for 1 month after death and can start replication and gene expression in rho0 cells without showing any functional defects. This procedure might be applied to human autopsy brain tissues for examination of the influence of accumulated somatic mutations in mtDNA from aged subjects.

Aging↗
PubMed1998

Age-related response to interferon alfa treatment in women vs men with chronic hepatitis C virus infection.

BACKGROUND: Interferon alfa is used widely for patients with chronic hepatitis C virus (HCV) infection. Little is known, however, of the relationship between patients' sex and the effectiveness of interferon alfa treatment in these patients. METHODS: We treated 311 patients (199 men and 112 women) with human lymphoblastoid interferon (6 million units subcutaneously every day for 2 weeks and 3 times a week for 22 weeks) and observed them for an additional 6 months. Serum HCV RNA levels and genotype were tested by polymerase chain reaction before treatment. A liver biopsy was also done. For the purposes of this study, a complete response was defined as the elimination of HCV RNA for at least 6 months after the termination of treatment. RESULTS: The rate of complete response was 27.1% for men and 24.1% for women. With multiple logistic regression analysis, the HCV RNA level (P < .001), genotype (P < .001), patients' sex (P < .05), and the interaction between sex and age were associated with a complete response to interferon alfa. The rate of complete response was 33.3% in men aged 39 years and younger, 25.0% in men aged 40 years and older. 75.0% in women aged 39 years and younger, and 15.6% in women aged 40 years and older. The odds ratio by group was 1.00, 0.72, 4.38, and 0.21, respectively. CONCLUSIONS: Our finding that women aged 39 years and younger are responsive to interferon alfa treatment suggests that hormonal activity, in particular the level of estrogen, may be associated with the sustained elimination of HCV.

Adult↗
PubMed1998

Intradermal administration of viral vaccines.

Intradermal administration maybe useful in lowering the cost of vaccination against hepatitis B significantly, and may also be helpful for the rapid induction of antibodies, reversing non-responsiveness, improving postexposure prophylaxis and immunising immunocompromised people. In addition, delayed type hypersensitivity skin reaction to the vaccine could serve as a useful marker for the acquisition of T helper type 1 immunoreactivity in vivo. However, there are some disadvantages when using intradermal vaccinations, including the requirement for skilful administration, the absence of approval from licensing authorities, the development of local skin reactions and a lower antibody response when 1/10 of the standard vaccine dose is used. This requires that appropriate vaccination regimens, including the correct vaccine dosage, and vaccination schedule are followed. In the future, a similar vaccination strategy might also be applied for the prevention and control of other infectious diseases. Copyright 1998 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1998

The long-term survival rates of patients after repair of abdominal aortic aneurysms.

This study was undertaken to examine the long-term survival rates of patients following abdominal aortic aneurysm (AAA) repair in comparison with an age-matched normal population, and to determine by multivariate analysis the factors influencing long-term survival. Of 125 patients who underwent AAA repair prior to July 1986, 13 died during hospitalization. Of these 13 patients, 6 who suffered aneurysmal rupture all died within 30 days. The survival rate of patients with ruptured aortic aneurysms was significantly lower than that of those with nonruptured aneurysms. Of the 112 patients surviving hospitalization, 85 died within 0.48 to 24 years after their operation. The long-term survival rate of patients who had suffered a preoperative cardiovascular event was significantly lower than that of those who had not suffered a preoperative cardiovascular event. The actual survival rate was significantly lower than the expected survival rate. According to a multivariate analysis, the significant predictors of late survival were age, aneurysmal rupture, and chronic renal failure in all the patients, and age, chronic renal failure, and pre- and postoperative cardiovascular events in patients who did not die in hospital. These findings indicate the importance of improving immediate perioperative management of ruptured AAA and that cardiovascular events should be prevented, or treated during long-term follow-up.

Adult↗
PubMed1998

Successful surgery for an acute type A aortic dissection following repair of a descending thoracic aortic aneurysm.

Acute type A aortic dissection in the presence of a previously repaired atherosclerotic descending thoracic aortic aneurysm is rarely reported. We experienced a patient who underwent an ascending aortic replacement with reconstruction of the aortic arch 16 months after repair of a descending thoracic aortic aneurysm. We succeeded in the redo operation with comprehensive techniques involving selective cerebral perfusion, deep hypothermia, early antegrade systemic circulation for cerebral protection, and femoro-femoral bypass with occlusion of the descending aorta for lower systemic perfusion as well as renal perfusion. The patient recovered and is doing well one year after the redo operation.

Acute Disease↗
PubMed1998

Left atrial ball thrombi without mitral valve disease treated by surgical removal.

We describe two patients with free-floating left atrial ball thrombi with no evidence of cardiac disease except atrial fibrillation. One patient had experienced an embolic stroke, and the second patient had a history of stroke and peripheral thromboembolism. In each patient, the thrombi, which were not visible on transthoracic echocardiography, were detected by transesophageal echocardiography. Each patient underwent successful surgical removal using cardiopulmonary bypass.

Aged↗
PubMed1998

Mycotic abdominal aortic aneurysm associated with myelodysplastic syndrome (MDS): report of a case.

A 59-year-old man, who manifested lower back pain, was admitted with sepsis and disseminated intravascular coagulation (DIC). A computed tomographic scan showed a slight thickening of the abdominal aortic wall. A blood examination revealed pancytopenia. Myelodysplastic syndrome was diagnosed after bone marrow aspiration and a chromosome analysis. Sepsis due to a Staphylococcus aureus infection and DIC subsided after medical treatment; however, an aortobifemoral bypass was performed upon the detection of a localized rupture of a mycotic abdominal aortic aneurysm 1 month later. The patient is still alive 2 years after operation despite the presence of a hematological disorder.

Aneurysm, Infected↗
PubMed1998

Successful removal of massive cardiac neurilemoma with cardiopulmonary bypass.

A 46-year-old woman was referred to our hospital because of cardiac enlargement seen on a chest radiograph. Imaging studies showed a massive intrapericardial tumor with a size of 12x8x7 cm. Tumor dissection included inspection of the inner aspect of the superior vena cava with use of cardiopulmonary bypass, because the mass was tightly adherent to both superior vena cava and right atrium. The pathologic diagnosis was neurilemoma.

Cardiopulmonary Bypass↗
PubMed1998

Surgery for giant popliteal artery aneurysm with a modified Sims' position.

A 73-year-old man with a giant popliteal artery aneurysm extending from the mid-thigh to the popliteal fossa underwent exclusion, bypass, and obliterative endoaneurysmorrhaphy while in a modified Sims' position. The use of this position allowed for exposure of the saphenous vein and the entire popliteal artery in the same operative field. No muscle division was required. Moreover, this position provided easy access to the superficial femoral and distal below-knee popliteal arteries.

Aged↗
PubMed1998

Comparison of HCV RNA levels by branched DNA probe assay and by competitive polymerase chain reaction to predict effectiveness of interferon treatment for patients with chronic hepatitis C virus.

To compare hepatitis C virus (HCV) RNA levels determined by branched DNA probe assay and by competitive polymerase chain reaction (PCR) as predictive markers of the response to interferon for treatment of patients with chronic HCV infection, we studied data on 140 patients treated for six months with natural interferon-alpha. Serum samples were tested for HCV RNA by PCR. HCV RNA was grouped into four genotypes by PCR with type-specific primers, and HCV RNA level was measured by branched DNA probe assay and by competitive PCR. HCV RNA was detected in all patients prior to initiation of the treatment. A complete response, sustained elimination of HCV RNA, occurred in 51 patients (36.4%). With multiple logistic regression analysis assessment, when using competitive PCR, a low level of HCV RNA (P < 0.0001), younger age (P = 0.0054) and genotype 2a and 2b (P < 0.0158) were significant predictive markers for a complete response to interferon treatment. When using branched DNA probe assay, a low level of HCV RNA (P < 0.0001) and age (P = 0.0089) were predictive markers, but genotype was not. The branched DNA probe assay had a narrower linear range for quantitation of HCV RNA level than competitive PCR. In conclusion, HCV RNA level determined by branched DNA probe assay proved to be useful for prediction of effects of interferon and it is cost effective as a marker of complete response to interferon treatment for patients with chronic HCV infection.

DNA Probes↗
PubMed1998

Hepatitis G virus in the general population and in patients on hemodialysis.

To determine the routes of transmission of hepatitis G virus (HGV) and the relationship between HGV and hepatitis C virus (HCV) infections, we tested for HGV RNA by polymerase chain reaction and antibody to HCV (anti-HCV) in 494 hemodialysis patients, 638 inhabitants of two HCV endemic areas, and in 400 blood donors in Japan. HGV RNA was detected in 6.9% of hemodialysis patients, in 1.4% of inhabitants, and in 0.8% of donors, and anti-HCV was detected in 39.3%, 12.4%, and 1.8%, respectively. Of HGV RNA-positive hemodialysis patients, and HGV RNA-positive inhabitants, 64.7% and 11.1%, respectively, had been given blood transfusions. The prevalences of HGV RNA and anti-HCV significantly increased with the duration of hemodialysis. Of all HGV RNA positives, 74.4% were coinfected with HCV and subjects with HGV RNA alone had normal liver function. In conclusion, HGV is transmitted by blood transfusion and within the hemodialysis unit itself. HGV does not seem to injure hepatocytes.

Adolescent↗
PubMed1998

Hepatitis C viral RNA status at two weeks of therapy predicts the eventual response.

We investigated the timing of the disappearance and reappearance of serum hepatitis C viral (HCV) RNA in patients with chronic hepatitis C during interferon treatment and follow-up. Serum samples were tested for HCV RNA by polymerase chain reaction in 62 patients with chronic hepatitis C treated with interferon-alpha for 24 weeks. We found that 17 patients obtained complete response, with absence of serum HCV RNA for 6 months after the treatment. Twenty-nine patients had a partial response, with reappearance of serum HCV RNA within 6 months of follow-up, and 16 patients were nonresponders who were positive for serum HCV RNA throughout the observation period. HCV RNA disappeared within 2 weeks of treatment in 31 patients, including all 17 (100%) complete responders and 14 (48.3%) of the 29 partial responders. The patients remaining positive for HCV RNA at the second week were 15 (51.7%) of the 29 partial responders and the 16 nonresponders. In all of the 29 partial responders, viremia recurred within 1 month after the treatment. These results indicate that the status of HCV RNA at the second week of treatment is a useful predictor of effective treatment, whereas status at the first month after cessation of treatment is useful for assessing the effectiveness of interferon itself.

Adult↗
PubMed1998

Aneurysm of a subclavian-vertebral artery saphenous vein bypass graft: case report.

OBJECTIVE AND IMPORTANCE: Although an autogenous saphenous vein is frequently used as a bypass graft, an aneurysm of a venous graft is a rare complication, especially in the case of cerebrovascular revascularization. We report a case of a successfully treated aneurysmal change in a venous graft after short vein bypass grafting. CLINICAL PRESENTATION: A 60-year-old man underwent a left subclavian-to-vertebral artery bypass operation with an interposed saphenous vein graft because of severe stenosis of the vertebral artery bilaterally. Angiograms of the left subclavian artery, obtained 4 months later, showed good patency of the graft without any dilation or stenosis. One year after the bypass surgery, the patient became aware of a pulsating mass in the left supraclavicular region, which was regarded as the grafted vein itself. A giant aneurysm of the vein graft, which developed at the nonanastomotic site, was shown in the angiogram 4 years later. INTERVENTION: The aneurysm was resected, and patch grafting of the orifice of the aneurysmal neck covered with an artificial vessel as a reinforcement was performed. CONCLUSION: The aneurysm seemed to have developed in a curved segment because of hemodynamic stress.

Anastomosis, Surgical↗