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Biomedical subjects

K Yasuda

Publications and source records attributed to K Yasuda.

At least 361 records · Page 20Linked to original sources
PubMed1999

Ruptured abdominal aortic aneurysms: analysis of factors influencing surgical results in 184 patients.

BACKGROUND: Rupture is often the first manifestation in patients with abdominal aortic aneurysms. Although elective surgery for non-ruptured abdominal aortic aneurysms has provided satisfactory surgical results, operative mortality of ruptured abdominal aortic aneurysms (rAAA) has not improved. The purpose of this study was to identify predictors for early hospital death in patients with rAAA. METHODS DESIGN: A retrospective study. SETTING: A university hospital and 20 affiliated hospitals. PATIENTS: PATIENTS undergoing surgical treatment for rAAA (n=183) between 1968 and 1997. INTERVENTIONS: All patients were surgically treated and divided into operative survivors (n=119) and non-survivors (n=64). MEASURES: The patient-related, procedure-related, and postoperative factors were compared between the two groups. A multivariate analysis was also conducted to determine predictors for hospital deaths. RESULTS: In univariate analysis, age at operation (p=0.004), preoperative hemodynamic conditions (p<0.0001), extent of hematoma (p<0.0001), preexistent renal dysfunction (p=0.001), and volumes of blood loss at operation (p=0.001) were significantly different between the two groups. The morbidity of postoperative renal failure (p<0.0001), gut ischemia (p=0.003), heart failure or ischemic heart disease (p<0.0001), and multiple organ dysfunction syndrome (p<0.0001) was higher in the non-survivors' group. Multivariate analysis also identified preoperative hemodynamic conditions, blood loss volume at operation, pre-existent renal dysfunction, postoperative renal failure, heart failure, and multiple organ dysfunction syndrome as incremental risk factors for hospital deaths. CONCLUSIONS: Every effort to maintain preoperative hemodynamic conditions, to reduce volumes of blood loss at operation, and to minimize deterioration of organ functions postoperatively is all essential to improve patient survival.

Adult↗
PubMed1999

American Academy of Pediatrics. Committee on Practice and Ambulatory Medicine and Committee on Medical Liability. Pediatric physician profiling.

Employers, insurers, and other purchasers of health care services collect data to profile the practice habits of pediatricians and other physicians. This policy statement delineates a series of recommendations that should be adopted by health care purchasers to guide the development and implementation of physician profiling systems.

Benchmarking↗
PubMed1999

[Antidepressants].

Explore the source record for details and available documents.

Antidepressive Agents↗
PubMed1999

[Modified Bentall's operation necessitating coronary artery bypass grafting: a case report].

A 67-year-old man was admitted to our hospital for the treatment of the aortic root aneurysm. Preoperative chest computed tomography revealed that the aneurysm was located mainly at the right and noncoronary Valsalva sinus with calcification around the right coronary ostia. Modified Bentall's operation was performed. The right coronary ostia was patent. However, atherosclerotic change was severe around the ostia showing intimal thickness, calcification, and partial defect of intima. Coronary artery bypass grafting (CABG) using saphenous vein was performed for the reconstruction of the right coronary artery. Piehler technique was used for the left coronary artery. The postoperative course was uneventful. When the preoperative examination shows calcification around the coronary ostia, CABG may be necessary for the reconstruction of the coronary artery in modified Bentall's operation.

Aged↗
PubMed1999

[Treatment of cancer ascites by combined intraperitoneal administration of low-dose CDDP and reinfusion of ultra-filtrated and concentrated ascitic fluid in patients].

Ascites due to carcinomatous dissemination is a severe problem for end-stage cancer patients. We attempted treating patients on an outpatient basis with the administration of low-dose CDDP-i.p. and reinfusion of ultrafiltrated and concentrated ascites. From 1995, we performed this therapy on 16 patients with concentrated ascites 6-8 fold and reinfusion, combined with low-dose CDDP-i.p. and drip infusion of 5-FU intravenously. The ascitic fluid was significantly decreased after treatment in 8 patients, and 2 patients had lasting low concentrations of CA 125. CA 125 decreased in 83.3% of patients, who tended to have extended survival times after remarkable ascites pooling and treatment with low-dose CDDP-i.p. and reinfusion therapy. This treatment is a useful cant method for decreasing ascites and improving QOL.

Adult↗
PubMed1999

Complement activation by mycoloyl glycolipids from Mycobacterium tuberculosis and Rhodococcus ruber.

In this study, we examined complement activation by mycoloyl glycolipids (MGL) such as trehalose-6,6'-dimycolate (TDM), often termed cord factor, and trehalose-6-monomycolate from Mycobacterium tuberculosis and Rhodococcus ruber, and also examined the effect of complement binding to MGL on phagocytosis by human monocytes. TDM and TMM, but not glucose mycolate, mannose mycolate or fructose mycolate which differ from TMM only in carbohydrate moiety, exhibited complement activation. TDM and TMM of M.tuberculosis exhibited stronger complement activation than those of R.ruber, the mycolic acids of which are much shorter than those of M.tuberculosis. Neither mycolic acids nor trehalose, which are products of TDM and TMM by hydrolytic cleavage, exhibited no complement activation. TDM activated complement through the alternative pathway, since supplementation with C4-deficient serum completely restored classical pathway-mediated hemolytic activity of complement which had been previously consumed by TDM. Next, we examined the effects of TDM and TMM on phagocytosis by human monocytes. Coating of heat-killed Staphylococcus aureus cells with TDM or TMM did not enhance their phagocytosis by monocytes, while, in the presence of complement, phagocytosis of these cells increased significantly. These findings suggest that TDM and TMM act as virulence factors that enhance the entry of mycobacteria into phagocytes via binding of C3 through activation of the alternative complement pathway.

Adjuvants, Immunologic↗
PubMed1999

Takayasu's aortitis treated surgically by extensive aortic replacement. A case report.

A case report of Takayasu's arteritis with aneurysmal involvement of the ascending aorta, aortic arch and descending thoracic aorta is presented. The patient underwent successful two-stage operation by use of Elephant trunk technique. During the first operation, replacement of ascending aorta and aortic arch was done under selective cerebral perfusion. During the second-stage operation, replacement of the descending thoracic aorta was performed under partial cardiopulmonary bypass. The postoperative course was uneventful and one year after surgery the patient is doing well. Specific conditions and operative strategy required in case of extensive aortic involvement in Takayasu's arteritis are discussed.

Aortography↗
PubMed1998

Transcriptional repressors are increased in pancreatic islets of type 2 diabetic rats.

To further clarify the mechanism of impaired insulin gene transcription in the diabetic state, we investigated the expression and function of the transcriptional repressor CREM (CRE modulator) in rat pancreatic islets. The CREM gene generates both transcriptional activators and repressors by alternative splicing and an intronic promoter. We isolated a novel alternatively spliced CREM isoform, CREM-17X, which efficiently represses insulin gene transcription, in addition to the three previously reported repressors. We also compared mRNA levels of insulin and the CREM repressors in pancreatic islets of Wistar and GK (Goto-Kakizaki) rats, the well-characterized spontaneous animal model of type 2 diabetes. The CREM repressor levels are increased, and the expression of insulin mRNA is decreased in GK rats, suggesting that increased CREM repressor expression in pancreatic islets could contribute to the decreased insulin gene transcription that results in impaired insulin secretion in type 2 diabetes.

Animals↗
PubMed1998

Effect of the Pro12Ala variant of the human peroxisome proliferator-activated receptor gamma 2 gene on adiposity, fat distribution, and insulin sensitivity in Japanese men.

To examine the role of the Pro12Ala variant of the human PPARgamma2 gene on adiposity and insulin resistance, we studied the effect of the variant on fat distribution assessed by CT scan, plasma glucose, and insulin levels during a 75g oral glucose load in 215 non-diabetic Japanese men. The allele frequency of the variant was 0. 03 in this population. There were no differences in body mass index (BMI), subcutaneous fat area (S), visceral fat area (V), V/S ratio, fasting plasma insulin levels, or insulin resistance index in homeostatic model assessment between 203 subjects who were homozygous for the wild-type Pro12 allele and 12 subjects with the variant Ala12 allele (11 heterozygotes and one homozygote). These data suggest that the Pro12Ala variant is not a major contributor to adiposity, fat distribution, or insulin resistance in Japanese men.

Adipose Tissue↗
PubMed1998

A mutation in succinate dehydrogenase cytochrome b causes oxidative stress and ageing in nematodes.

Much attention has focused on the aetiology of oxidative damage in cellular and organismal ageing. Especially toxic are the reactive oxygen byproducts of respiration and other biological processes. A mev-1(kn1) mutant of Caenorhabditis elegans has been found to be hypersensitive to raised oxygen concentrations. Unlike the wild type, its lifespan decreases dramatically as oxygen concentrations are increased from 1 to 60%. Strains bearing this mutation accumulate markers of ageing (such as fluorescent materials and protein carbonyls) faster than the wild type. We show here that mev-1 encodes a subunit of the enzyme succinate dehydrogenase cytochrome b, which is a component of complex II of the mitochondrial electron transport chain. We found that the ability of complex II to catalyse electron transport from succinate to ubiquinone is compromised in mev-1 animals. This may cause an indirect increase in superoxide levels, which in turn leads to oxygen hypersensitivity and premature ageing. Our results indicate that mev-1 governs the rate of ageing by modulating the cellular response to oxidative stress.

Aging↗
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

Association of HSP105 with HSC70 in high molecular mass complexes in mouse FM3A cells.

The 105-kDa stress proteins HSP105alpha and HSP105beta belong to a high molecular mass heat shock protein family which has been found in organisms from yeast to mammals. Here we demonstrated the interaction of HSP105 with HSP70 family proteins in mouse FM3A cells. The association of HSP105 with HSC70 was shown by immunoprecipitation using anti-HSP105 antibody. Furthermore, when cell extracts or partially purified HSP105 fractions from nonstressed or heat-shocked cells were analyzed by size exclusion chromatography, density gradient centrifugation or cross-linking, HSP105 was detected as HSP105/HSC70 complexes with molecular masses of approximately 300-500-kDa, 160-kDa or 200-kDa, respectively. Since the 160-200-kDa complexes must be HSP105/HSC70 heterodimers, the 300-500-kDa complexes seemed to consist of HSP105/HSC70 heterotetramers possibly with other proteins. Our finding that HSP105 is complexed with HSC70 suggests that HSP105 may function cooperatively with HSC70, that HSP105 regulates the function of HSC70 or that HSC70 reversibly regulates the function of HSP105 in cells under both nonstressed and stressed conditions.

Adenosine Triphosphate↗