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Biomedical subjects

T Fukui

Publications and source records attributed to T Fukui.

At least 91 records · Page 5Linked to original sources

Effects of troglitazone on collagen accumulation and distensibility of aortic wall in prestage of non-insulin-dependent diabetes mellitus of Otsuka Long-Evans Tokushima Fatty rats.

We investigated the effect of troglitazone (TG) on aortic distensibility and histopathology at the preclinical stage in the non-insulin-dependent diabetes mellitus (NIDDM) model. Twenty male diabetic and 20 male nondiabetic rats were each divided into two groups: treated-DM, untreated-DM, treated-nonDM, and untreated-nonDM. TG (0.2%) was mixed in chow in the treated groups. From age 5 to 15 weeks, fast blood glucose and insulin were monitored. At 15 weeks, oral glucose tolerance test results, aortic wall histopathology, and collagen content were studied, and intravascular ultrasound images and aortic pressure were recorded. Aortic diameter was measured during the cardiac cycle, and the stiffness parameter beta was calculated. Blood glucose (mg/dl) 2 h after loading in treated-DM (139+/-20) was normalized (untreated-DM, 188+/-27; p<0.05). Insulin concentration (ng/ml) in treated-DM (3.2+/-0.4) was lower than that in untreated-DM (8.1+/-1.5; p<0.01). At 15 weeks, beta in untreated-DM (2.4+/-0.8) was larger than those in untreated-nonDM (1.5+/-0.4; p<0.0001) and in treated-DM (1.9+/-0.4, p = 0.0081). Aortic wall collagen (mg/g dry weight) increased in untreated-DM (32.8+/-3.3) as compared with treated-DM (28.1+/-3.8; p = 0.048). Histomorphometry showed decreased medial area (mm2) in treated-DM (0.55+/-0.05) compared with untreated-DM (0.78+/-0.12; p<0.0001). This study suggests that TG may prevent metabolic abnormalities and the deterioration of aortic distensibility at an early prediabetic stage.

Animals↗

Prevalence of Lyme disease Borrelia spp. in ticks from migratory birds on the Japanese mainland.

Borrelia sp. prevalence in ticks on migratory birds was surveyed in central Japan. In autumn, a total of 1,733 birds representing 40 species were examined for ticks. A total of 361 ticks were obtained from 173 birds of 15 species, and these ticks were immature Haemaphysalis flava (94.4%), Haemaphysalis longicornis, Ixodes columnae, Ixodes persulcatus, Ixodes turdus, and an unidentified Ixodes species. Of these, 27 juveniles of H. flava on Turdus pallidus, Turdus cardis, or Emberiza spodocephala, 2 juveniles of I. persulcatus on T. pallidus, and 1 female H. flava molted from a T. pallidus-derived nymph were positive for the presence of Borrelia by Barbour-Stoenner-Kelly culture passages. In spring, a total of 16 ticks obtained from 102 birds of 21 species were negative for the spirochete. Isolates from 15 ticks were characterized by 5S-23S rRNA intergenic spacer restriction fragment length polymorphism analysis; all isolates were identified as Borrelia garinii with pattern B/B' based on the previous patterning. According to the intergenic spacer sequences, 2 of 15 isolates, strains Fi14f and Fi24f, were highly similar to B. garinii strains 935T of Korea and ChY13p of Inner Mongolia, China, respectively. These findings indicate that Lyme disease-causing B. garinii may have been introduced to Japan by migratory birds from northeastern China via Korea. Additionally, a case of transstadial transmission of B. garinii from nymph to adult H. flava suggests that the infected H. flava may transmit Borrelia to large animals.

Animals↗

Real-time automated PCR for early diagnosis and monitoring of cytomegalovirus infection after bone marrow transplantation.

The purpose of this study was to assess the usefulness of real-time automated PCR as a quantitative, highly reproducible, and sensitive method to detect cytomegalovirus (CMV) DNA in blood specimens. Intra- and interassay precision rates were 0.89% (small number of copies [L]), 1.43% (middle number of copies [M]), and 1.12% (high number of copies [H]), and 4.46% (L), 1.51% (M), and 2.28% (H), respectively. The linearity of this assay was obtained between 10 and 10(7) copies/well, with a minimum detection limit of 20 copies/well. Specimens from 55 of 70 healthy subjects were found to be positive for CMV antibody, but CMV DNA was not detected in any of them. In the qualitative assessment of each specimen, the results of the CMV antigenemia assay and those of the real-time PCR assay agreed in 80% (plasma specimens), 79% (all nucleated cells), and 86% (blood) of the cases examined. For eight patients diagnosed as having CMV infection or disease, no sample was positive in the antigenemia assay earlier than in the real-time PCR assay. Furthermore, the results of this assay could be obtained within 8 h. We concluded that the real-time PCR assay is useful for rapid diagnosis of CMV infection and monitoring of clinical courses.

Adolescent↗

Bacillus Calmette-Guérin perfusion therapy for the treatment of transitional cell carcinoma in situ of the upper urinary tract.

OBJECTIVES: The aim of this study is to evaluate the efficacy and safety of intrarenal bacillus Calmette-Guérin (BCG) instillation as a treatment for transitional cell carcinoma in situ (CIS) of the upper urinary tract. METHODS: Diagnostic criteria of upper urinary tract CIS were (1) positive urinary cytology, (2) negative multiple random biopsy of the bladder and prostatic urethra, (3) negative radiographic findings in the upper urinary tract and (4) two serial positive cytologies in selective ipsilateral urine sampling from the pyeloureteral system. Eleven patients diagnosed as having upper urinary tract CIS were enrolled in this study. Thus, 11 renal units were treated with BCG instillation. After placing a 6-french Double-J stent, BCG (80 mg) in 40 ml saline was instilled into the bladder weekly, 6 times in total as one course. RESULTS: At the end of one course, 9 cases showed negative urinary cytology. Among these 9 cases, 2 showed recurrence in the upper urinary tract after 4 months and 8 months of disease-free interval, respectively. These 2 cases have received an additional course of BCG instillation, but the urinary cytology did not normalize. Mean recurrence-free time was 19.6 months. Of the other 7 cases who responded to the first course of instillation, 6 cases were alive with no evidence of the disease. The remaining patient died of rectal cancer with no evidence of transitional cell carcinoma (TCC). Of the 2 cases who showed positive urinary cytology even after the first course, 1 underwent nephroureterectomy. The other case was diagnosed as having malignant lymphoma 3 months after the end of this instillation therapy, and he died of malignant lymphoma. As side effects, 8 cases (72.7%) showed bladder irritability, and 4 presented fever higher than 38 degrees C. However, no patient needed antitubercular treatment. CONCLUSION: As for the short-term response, BCG instillation for the treatment of upper urinary tract CIS is considered to be effective and safe. Longer follow-up and further experience with this treatment are required.

Adjuvants, Immunologic↗

Induction of apoptosis in the human promyelocytic leukemia cell line HL60 by falconensone A and its derivatives, new polyenes.

Falconensones A and B are a new type of yellow pigment with structural similarity to retinoic acid isolated from the mycelial extract of ascomycetous fungi, Emericella falconensis or Emericella fruticulosa. In the present study we show that falconensone A alone induced apoptosis of HL60 human leukemia cells, while falconensone B, the 4'-nor-methyl derivative of falconensone A, had much lower activity. The synthetic derivatives of falconensone A, falconensone A p-bromophenylhydrazone and falconensone A dioxime, were more potent than natural falconensone A and B as far as the induction of apoptosis was concerned. The induction of apoptosis by the falconensones correlated with their inhibition of cell growth. In addition, falconensones A and B, and falconensone A dioxime, increased the generation of intracellular reactive oxygen species, while falconensone A p-bromophenylhydrazone was inactive. These results suggest that falconensone A, falconensone A p-bromophenylhydrazone and falconensone A dioxime are potential new apoptosis-inducing agents. The enhanced generation of reactive oxygen species in cells may be involved in apoptosis induced by falconensone A and falconensone A dioxime, but not by falconensone A p-bromophenylhydrazone. It is also suggested that the methyl residue at the 4' position of the falconensone A cyclopentenone ring may be essential for the induction of apoptosis. Based on these results, falconensone A and its derivatives may be clinically useful in the treatment of some leukemias.

Apoptosis↗

Antioxidant properties of a new type of polyene, falconensone A and its derivatives.

Falconensones A and B are new type of yellow compound extracted from ascomycetous fungi, Emericella falconensis. Falconensone A p-bromophenylhydrazone and falconensone A dioxime are derivatives of falconensone A which have also been synthesized recently. The structural similarity of the falconensones to alpha-tocopherol (vitamin E) led us to investigate whether falconensones exhibit antioxidant activity. These studies found that falconensone A p-bromophenylhydrazone and falconensone A dioxime scavenge alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radical in a 1 : 1 ratio in contrast to vitamin E, where a 1 : 2 ratio relative to DPPH radicals was observed. In addition, linoleic acid peroxidation initiated by hydroxyl radicals was diminished by falconensone A p-bromophenylhydrazone to a greater extent than by vitamin E, and lipid peroxidation in rat liver microsome was reduced by falconensone A dioxime and falconensone A p-bromophenylhydrazone. In contrast, falconensone A and falconensone B, the 4'-nor-methyl derivative of falconensone A, showed much lower activity or were inactive in scavenging radicals. These results suggest that falconensone A p-bromophenylhydrazone and falconensone A dioxime, may be useful new antioxidant agents, wherein the bromophenyl and hydroxy residues of falconensone A may be important for antioxidant activity. Based on these results, derivatives of falconensone A appear to be effective antioxidants that may have clinical utility for diseases treated with vitamin E.

Animals↗

Do taught courses on community medicine change knowledge status regarding clinical epidemiology and biostatistics in medical students?

This study aimed to explore the changes in medical student's knowledge and attitudes regarding clinical epidemiology and biostatistics (CEB) after community medicine (CM) taught courses. All the 3rd (before CM-taught courses) and 4th year (after CM-taught courses) undergraduate students of Dhaka Medical College, Bangladesh, were given a questionnaire concerning some introductory level problems on CEB and attitudes towards them. Mean knowledge scores were not statistically different between these two groups: 3.70 and 3.85 (out of 9) on clinical epidemiology; 0.20 and 0.18 (out of 4) on biostatistics; and 3.91 and 4.04 as a total (out of 13) among them, respectively. Most of the 3rd and 4th year students agreed that CEB is essential for smooth understanding of clinical medicine and journals, and asserted to include it in CM-taught courses. Since the current CM-curriculum does not offer any improvement of knowledge among them, well-planned taught courses on it should be included as a component of CM.

Adult↗

Suppressive effect of curcumin on trichloroethylene-induced oxidative stress.

In vivo antioxidative effects of curcumin were investigated using a trichloroethylene (TCE)-induced oxidative stress model in mouse liver. Increases in the contents of peroxisome and thiobarbituric acid reactive substances (TBARS) and decreases in GSH content of mouse liver by the TCE administration were suppressed by the pre-administration of curcumin. TCE-induced changes in the activities of antioxidative enzyme, such as Cu/Zn-SOD, catalase, glutathione reductase. glutathione peroxidase (GPx) and D-glucose-6-phosphate dehydrogenase (G6PD), were also diminished by curcumin. These results indicate that curcumin significantly suppresses TCE-induced oxidative stress by scavenging various free radicals, and its antioxidative activity seems to be derived from its suppressive effects on the increase in peroxisome content and decrease in GPx and G6PD activities.

Animals↗

[A case of left ventricular rupture and left ventricular-right atrial communication after mitral valve re-replacement].

We report a case of left ventricular rupture and left ventricular-right atrial communication after mitral valve re-replacement. A 53-year-old man was admitted to our hospital for a primary tissue failure of mitral xenograft. On June 4, 1997, he underwent mitral valve re-replacement. At 12 post operative day, he was suffered from unexpected dyspnea. The transesophageal echocardiography showed floated mitral valve and left ventricular-right atrial communication. The emergent operation was done. At the operation, posterior mitral annulus was disrupted and the disruption reached to a membranous septum. A communication was directly closed, mitral annulus was repaired with perigard and one size smaller mitral valve was implanted. The patient was discharged and returned to social life.

Fistula↗

Factors affecting the freeze-fracture morphology of in vivo polyhydroxyalkanoate granules.

Interesting morphologies were observed when Comamonas acidovorans containing polyhydroxyalkanoates (PHA) of various compositions was freeze-fractured at temperatures far below the glass transition temperatures of PHA. In vivo granules of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) comparatively showed the most ductility, and could be stretched extensively. Contrary to the uniform needle-type deformation shown by the poly(3-hydroxybutyrate) homopolymer when fractured at -110 degrees C, copolymers containing 3-hydroxyvalerate units showed various deformation structures. Similar observations were made when in vivo granules of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) were freeze-fractured, although the ductility of the latter was much reduced. In addition, it was found that fracturing at -160 degrees C resulted in decreased ductility of the PHA granules with the concomitant increase in the number of mushroom-type deformation structures. Our results suggest that PHA granules with higher resistance to freeze-fracture deformation show less ductility, and therefore produce the mushroom-type morphology. This is the first report on the freeze-fracture morphology of PHA copolymers containing short-chain-length monomers.

Cupriavidus necator↗

Renal interstitial concentration of adenosine during endotoxin shock.

The present experiments were designed to measure the renal interstitial concentration of adenosine in an attempt to determine whether adenosine participates in the regulation of renal hemodynamics during endotoxin shock. The renal concentration of adenosine in response to lipopolysaccharide (LPS) administration was measured in anesthetized dogs using a microdialysis method. Renal hemodynamic responses to LPS were also determined with and without the adenosine A(1) receptor antagonist, (E)-(R)-1-[3-(2-phenylpyrazolo[1, 5-a]pyridin-3-yl)acryloyl]pyperidin-2-ylacetic acid (FK352). Intravenous administration of LPS (0.5 mg/kg) significantly decreased renal blood flow and mean arterial pressure. These parameters reached the minimum level at 5-10 min after the LPS administration and then returned to their respective preinjection levels. The renal interstitial concentration of adenosine increased from 118+/-18 to 381+/-46 nM. During treatment with FK352, LPS decreased renal blood flow and mean arterial pressure, however, these reductions were significantly attenuated. LPS also increased adenosine concentration, but its rise was reduced along with the attenuation of LPS-induced renal blood flow reduction. These results suggest that adenosine was involved in LPS-induced renal hemodynamic changes and that FK352 has a protective effect against renal dysfunction during endotoxin shock. Since the adenosine concentration was inversely proportional to renal blood flow levels, it can be assumed that adenosine plays an important role as a mediator, but not as an initiator of renal hemodynamic changes during endotoxin shock.

Adenosine↗

Ribulose bisphosphate carboxylase/oxygenase from the hyperthermophilic archaeon Pyrococcus kodakaraensis KOD1 is composed solely of large subunits and forms a pentagonal structure.

We previously reported the presence of a highly active, carboxylase-specific ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in a hyperthermophilic archaeon, Pyrococcus kodakaraensis KOD1. In this study, structural analysis of Pk -Rubisco has been performed. Phylogenetic analysis of Rubiscos indicated that archaeal Rubiscos, including Pk -Rubisco, were distinct from previously reported type I and type II enzymes in terms of primary structure. In order to investigate the existence of small subunits in native Pk -Rubisco, immunoprecipitation and native-PAGE experiments were performed. No specific protein other than the expected large subunit of Pk -Rubisco was detected when the cell-free extracts of P. kodakaraensis KOD1 were immunoprecipitated with polyclonal antibodies against the recombinant enzyme. Furthermore, native and recombinant Pk -Rubiscos exhibited identical mobilities on native-PAGE. These results indicated that native Pk -Rubisco consisted solely of large subunits. Electron micrographs of purified recombinant Pk -Rubisco displayed pentagonal ring-like assemblies of the molecules. Crystals of Pk -Rubisco obtained from ammonium sulfate solutions diffracted X-rays beyond 2.8 A resolution. The self-rotation function of the diffraction data showed the existence of 5-fold and 2-fold axes, which are located perpendicularly to each other. These results, along with the molecular mass of Pk -Rubisco estimated from gel filtration, strongly suggest that Pk -Rubisco is a decamer composed only of large subunits, with pentagonal ring-like structure. This is the first report of a decameric assembly of Rubisco, which is thought to belong to neither type I nor type II Rubiscos.

Archaeal Proteins↗

Co-expression of 3-ketoacyl-ACP reductase and polyhydroxyalkanoate synthase genes induces PHA production in Escherichia coli HB101 strain.

The Escherichia coli 3-ketoacyl-ACP reductase gene (fabGEc) was cloned using a PCR technique to investigate the metabolic link between fatty acid metabolism and polyhydroxyalkanoate (PHA) production. Three plasmids respectively harboring fabGEc and the poly-3-hydroxyalkanoate synthesis genes phaCAc and phaC1Ps from Aeromonas caviae and Pseudomonas sp. 61-3 respectively were constructed and introduced into E. coli HB101 strain. On a two-stage cultivation using dodecanoate as the sole carbon source, recombinant E. coli HB101 strains harboring fabGEc and phaC genes accumulated PHA copolymers (about 8 wt% of dry cell weight) consisting of several (R)-3-hydroxyalkanoate units of C4, C6, C8, and C10. It has been suggested that overexpression of the fabGEc gene leads to the supply of (R)-3-hydroxyacyl-CoA for PHA synthesis via fatty acid degradation.

3-Oxoacyl-(Acyl-Carrier-Protein) Reductase↗

Effects of halothane on renal hemodynamics and interstitial nitric oxide in rabbits.

The effects of halothane on renal hemodynamics and the nitric oxide (NO)-guanylate cyclase signaling pathway were examined in anesthetized rabbits using a renal microdialysis method. Halothane (0.5 and 2 vol%) caused dose-dependent decreases in blood pressure, renal blood flow and the renal interstitial concentrations of guanosine 3',5'-cyclic monophosphate (cGMP) or nitrate (NO2)/nitrite (NO3). Sodium nitroprusside (20 microg kg(-1) min(-1), i.v.) under the inhalation of halothane (2 vol%) increased the renal interstitial concentration of cGMP. L-Arginine (priming dose, 300 mg kg(-1) 10 min(-1); sustaining dose, 50 mg kg(-1) min(-1), i.v.) did not reverse halothane-induced reductions of cGMP and NO2/NO3. These findings demonstrate that halothane caused a renal vasoconstriction and inhibited the NO-guanylate cyclase signaling pathway in the kidney. Moreover, it is possible that the renal hemodynamic responses to halothane might have been induced, in part, through this inhibition. Finally, it can be assumed that halothane did not interfere with the activation process of guanylate cyclase by NO.

Anesthetics, Inhalation↗