Biomedical subjects

H Sato

Publications and source records attributed to H Sato.

At least 73 records · Page 4Linked to original sources

PubMed2004

Characterization of a point mutation in the parC gene of Mycoplasma bovirhinis associated with fluoroquinolone resistance.

Quinolone-resistant (QR) mutants of Mycoplasma bovirhinis strain PG43 (type strain) were generated by stepwise selection in increasing concentrations of enrofloxacin (ENR). An alteration was found in the quinolone resistance-determining region (QRDR) of the parC gene coding for the ParC subunit of topoisomerase IV from these mutants, but not in the gyrA, gyrB, and parE gene coding for the GyrA and GyrB subunits of DNA gyrase and the ParE subunit of topoisomerase IV. Similarly, such an alteration in QRDR of parC was found in the field isolates of M. bovirhinis, which possessed various levels of QR. The substitution of leucine (Leu) by serine (Ser) at position 80 of QRDR of ParC was observed in both QR-mutants and QR-isolates. This is the first report of QR based on a point mutation of the parC gene in M. bovirhinis.

Animals↗

PubMed2004

KL-6 levels are elevated in plasma from patients with acute respiratory distress syndrome.

The acute respiratory distress syndrome (ARDS) is an extreme form of lung injury characterised by disruption to the alveolar epithelium. KL-6 is a mucin-like glycoprotein expressed on type II pneumocytes. Circulating levels of KL-6 have diagnostic and prognostic significance in a number of interstitial lung diseases, and when elevated are thought to indicate disruption of the alveolar epithelial lining. In this study, the authors sought to determine whether plasma KL-6 levels were elevated in patients with ARDS and whether these were associated with aetiology, disease severity, outcome or ventilatory strategy. Plasma samples were collected from 28 patients with ARDS, nine ventilated controls of matched illness severity and 10 healthy individuals. KL-6 concentrations were measured by enzyme-linked immunosorbent assay. Patients with ARDS had higher plasma levels of KL-6 (median 537 U x mL(-1), interquartile range (IQR) 383-1,119), as compared to ventilated controls (median 255 U x mL(-1), IQR 83-338) and normal individuals (median 215 U x mL(-1), IQR 149-307). In patients with ARDS, plasma KL-6 levels were higher in nonsurvivors than survivors, and correlated positively with oxygenation index and negatively with arterial oxygen tension:inspiratory oxygen fraction ratio. There were also significant positive correlations with mean and peak airway pressures. Elevated levels of plasma KL-6 may provide a useful marker for acute respiratory distress syndrome in ventilated patients and have possible prognostic significance. Alveolar epithelial cell damage may be influenced by the nature of mechanical ventilatory support.

Adult↗

PubMed2004

[Mycobacteria other than tuberculosis combined primary lung cancer].

From January 1997 to June 1999, we performed surgery in 17 patients with mycobacteria other than tuberculosis (MOTT), and 2 patients with lung cancer among them. Both patients had the diagnosis of MOTT by sputa bacterial cultures preoperatively, but no diagnosis of lung cancer. By computed tomography (CT) scanning, lung cancer was suspected in both patients, therefore they were performed video-assisted thoracoscopic resection of the lung. The diagnosis of malignancy was made by intraoperative frozen section of resected tissue, the patients were performed lobectomy with systematic mediiastinal lymph nodes dissection. According to increment of detection of the small peripheral lesion, infectious disease such as MOTT can be detected as small abnormal shadow by CT. However, it is difficult to distinguish malignancy from infectious disease preoperatively. Even if a preoperative diagnosis, of MOTT was made like present cases, diagnostic video-assisted thoracoscopic surgery must be performed, considering that lung cancer could combined with MOTT.

Aged↗

PubMed2004

[Prostacyclin oral internal therapy for severe pulmonary hypertension after total correction of cor triatriatum with partial anomalous pulmonary venous return; report of a case].

A 37-day-old girl having cor triatriatum with partial anomalous pulmonary venous return was found on emergent admission. Echocardiography and angiography revealed severe pulmonary hypertension with anomalous pulmonary venous return to inominate vein. She still was in respiratory failure after emergent surgical repair because of severe pulmonary hypertension following pulmonary venous obstruction. Prostacyclin is the first Food and Drug Administration (FDA)-approved treatment for advanced primary pulmonary hypertension, which has antithrombotic properties related to its effect on platelets and is a potent vasodilator of both the systemic and pulmonary arteries, and has positive inotropic properties. We started prostacyclin oral internal therapy for her and she recovered from respiratory problems very quickly. Prostacyclin might be effective for pulmonary hypertension before and after surgical repair as primary pulmonary hypertension.

Administration, Oral↗

PubMed2004

Detection and quantification of circulating tumor cells in patients with esophageal cancer by real-time polymerase chain reaction.

Polymerase chain reaction (PCR) amplification was used for detecting circulating tumor cells. However, PCR was so sensitive that it detected a very low level of mRNA with no relevance to tumor cells. We analyzed the degree of micro-tumor spread in esophageal cancer patients using quantitative PCR. Samples were collected from 28 patients and 35 controls. Real-time quantitative PCR (LightCycler) was employed for the detection of carcinoembryonic antigen (CEA) and cytokeratin 20 (CK-20). In the CEA and CK-20 mRNA assays, 7 and 3 out of 28 patients, respectively, showed higher mRNA levels in peripheral blood than the normal range based on values of controls (mean+/-2SD). Eleven out of 19, 4 out of 14, and 2 out of 5 patients showed higher CEA mRNA levels in the samples from tumor drainage vein, costal bone marrow, and thoracic duct lymph, respectively. One of the 7 patients who showed higher CEA mRNA levels in pretreatment peripheral blood is currently free from disease. These findings reveal that quantitative PCR can discriminate high levels of cancer-specific expression from low levels of illegitimate expression in blood. They also suggest that the identification of circulating tumor cells by the CEA mRNA assay is a reliable means of predicting early recurrence.

Aged↗

PubMed2003

Probing the superconducting gap symmetry of PrOs4Sb12: a penetration depth study.

We report measurements of the magnetic penetration depth lambda in single crystals of PrOs4Sb12 down to 0.1 K, with the ac field applied along the a, b, and c directions. In all three field orientations, lambda approximately T2 and superfluid density rho(s) approximately T2 for T<0.3T(c). Data are best fit by the 3He A-phase-like gap with multidomains, each having two point nodes along a cube axis, and parameter Delta(0)(0)/k(B)T(c)=2.6, suggesting that PrOs4Sb12 is a strong-coupling superconductor with two point nodes on the Fermi surface. We also confirm the double transitions at 1.75 and 1.85 K seen in other measurements.

Journal Article↗

PubMed2003

Transformation of the monocotyledonous Alstroemeria by Agrobacterium tumefaciens.

An efficient procedure is described for the transformation of the monocotyledonous Alstroemeria by Agrobacterium tumefaciens via callus regeneration. Calli derived from ovules were co-cultivated with A. tumefaciens strains EHA101 and LBA4404, which harbored the binary vector plasmids pIG121Hm and pTOK233, respectively. These plasmids contain the beta-glucuronidase gene ( gusA) as a reporter gene and the hygromycin phosphotransferase and neomycin phosphotransferase II ( nptII) genes as selective markers. Inoculated calli were first plated for 4 weeks on medium containing cefotaxime to eliminate bacteria, following which time transformed cells were selected on medium that contained 20 mg/l hygromycin. A histochemical assay for GUS activity revealed that hygromycin-based selection was completed after 8 weeks. The integration of the T-DNA of pIG121Hm and pTOK233 into the genome of the cells was confirmed by PCR analysis. Efficient shoot regeneration from the transformed calli was observed on half-strength MS medium supplemented with 0.5 mg/l naphthaleneacetic acid and 0.5 mg/l benzyladenine after about 5 months of culture. The presence of the gusA and nptII genes in the genomic DNA of regenerated plants was detected by means of PCR and PCR-Southern hybridization, and the expression of these transgenes was verified by reverse transcription-PCR.

Agrobacterium tumefaciens↗

PubMed2003

Time-reversal symmetry-breaking superconductivity in heavy-fermion PrOs4Sb12 detected by muon-spin relaxation.

We report on muon-spin relaxation measurements of the 4f(2)-based heavy-fermion superconductor filled-skutterudite Pr(Os4Sb12. The results reveal the spontaneous appearance of static internal magnetic fields below the superconducting transition temperature, providing unambiguous evidence for the breaking of time-reversal symmetry in the superconducting state. A discussion is made on which of the spin or orbital component of Cooper pairs carries a nonzero momentum.

Journal Article↗

PubMed2003

Influence of metallic chlorides on the formation of PCDD/Fs during low-temperature oxidation of carbon.

Experimental study was conducted to clarify the formation behavior of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from carbonaceous materials through a de novo synthesis route. Samples were prepared by changing mixing method and composite state of metallic chloride in graphite powder in order to simulate the texture of "unburned carbonaceous particles", i.e., soot, formed in thermal processes. Reagents of KCl, CaCl2. 2H2O, FeCl3 x 6H2O, and CuCl2 x 2H2O were used as chlorine sources and were added to graphite powder with different methods. The composite state of metallic chloride was varied by preliminary treatments: hand-mixing, mixed-grinding using a high-intensity ball mill, and preheating at different temperatures between 500 and 1100 degrees C. In the de novo experiment, reaction temperature and oxygen concentration of flowed gas were set at 300 degrees C and 2.5 mol %, respectively. During the experiment, formation rates of CO and CO2 and the formed amounts of organic chlorine and PCDD/Fs were measured. The results show a reasonable relation between the amount of formed organic chlorine and oxidation rate of carbon, and the order of the activity of metallic chlorines was obtained as KCl < CaCl2 < FeCl3 << CuCl2. Furthermore, it was found that the effect of the composite state of metallic chloride on the formation of PCDD/Fs significantly depends on the kind of metal. The results will give useful information to examine the formation mechanism of PCDD/Fs from unburned carbon particles in thermal processes.

Benzofurans↗

PubMed2003

Analysis of long-chain polyprenols using supercritical fluid chromatography and matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

The separation of long-chain polyprenols was successfully achieved using supercritical fluid chromatography (SFC). Each 100-mer greater component was separated using tetrahydrofuran as a mobile phase modifier. The molecular mass distributions derived from SFC analyses agreed with the results of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analyses. The number-average molecular mass calculated by MALDI-TOF-MS data were also in accord with the results of quantitative 1H-NMR analysis of terminal groups. A combination of SFC and MALDI-TOF-MS analyses is a powerful tool for the elucidation of the complicated structures of natural polyprenols.

Chromatography, Supercritical Fluid↗

PubMed2003

Role of cystine transport in intracellular glutathione level and cisplatin resistance in human ovarian cancer cell lines.

Transport system x(c)(-) is a member of plasma membrane heterodimeric amino-acid transporters and consists of two protein components, xCT and 4F2hc. This system mediates cystine entry coupled with the exodus of intracellular glutamate and regulates the intracellular glutathione (GSH) levels in most mammalian cultured cells. We studied the activity of system x(c)(-) and GSH content in human ovarian cancer cell line (A2780) and its cisplatin (CDDP)-resistant variant (A2780DDP). The rate of cystine uptake was approximately 4.5-fold higher in A2780DDP cells than in A2780 cells and the cystine uptake in A2780DDP cells was mediated by system x(c)(-). Intracellular GSH content was much higher in A2780DDP cells but it fell drastically in the presence of excess glutamate, which inhibited the cystine uptake competitively. xCT and 4F2hc mRNAs were definitely expressed in A2780DDP cells, but far less in A2780 cells. Expression of system x(c)(-) activity by transfection with cDNAs for xCT and 4F2hc made A2780 cells more resistant to CDDP. Similar results on the cystine uptake were obtained in human colonic cancer cell lines. These findings suggest that the system x(c)(-) plays an important role in maintaining the higher levels of GSH and consequently in CDDP resistance in cancer cell lines.

Amino Acid Transport Systems↗

PubMed2003

Multiple superconducting phases in new heavy fermion superconductor PrOs4Sb12.

The superconducting gap structure of recently discovered heavy fermion superconductor PrOs4Sb12 was investigated by using thermal transport measurements in magnetic field rotated relative to the crystal axes. We demonstrate that a novel change in the symmetry of the superconducting gap function occurs deep inside the superconducting state, giving a clear indication of the presence of two distinct superconducting phases with twofold and fourfold symmetries. We infer that the gap functions in both phases have a point node singularity, in contrast to the familiar line node singularity observed in almost all unconventional superconductors.

Journal Article↗

PubMed2003

Evidence for unconventional strong-coupling superconductivity in PrOs4Sb12: an Sb nuclear quadrupole resonance study.

We report Sb-NQR results which evidence a heavy-fermion (HF) behavior and an unconventional superconducting (SC) property in Pr(Os4Sb12 with T(c)=1.85 K. The temperature (T) dependence of nuclear-spin-lattice-relaxation rate, 1/T(1), and NQR frequency unravel a low-lying crystal-electric-field splitting below T0 approximately 10 K, associated with Pr3+(4f(2))-derived ground state. In the SC state, 1/T(1) shows neither a coherence peak just below T(c) K nor a T3-like power-law behavior observed for anisotropic HF superconductors with the line-node gap. The isotropic energy gap with its size Delta/k(B)=4.8 K seems to open up across T(c) below T(*) approximately 2.3 K. It is surprising that Pr(Os4Sb12 looks like an isotropic HF superconductor-it may indeed argue for Cooper pairing via quadrupolar fluctuations.

Journal Article↗

PubMed2003

Infection of macaques with an R5-tropic SHIV bearing a chimeric envelope carrying subtype E V3 loop among subtype B framework.

To establish simian/human immunodeficiency virus (SHIV) clones bearing a chimeric envelope carrying subtype E V3 loop among subtype B envelope, four subtype E V3 sequences were substituted into SHIV(MD14), a SHIV clone bearing an envelope derived from a CXCR4 (X4)/CCR5 (R5)-dual tropic subtype B HIV-1 strain. SHIV-TH09V3, an only V3-chimera clone capable of replicating in human and macaque peripheral blood mononuclear cells (PBMCs), was propagated in pig-tailed macaque PBMCs and in cynomolgus macaque splenic mononuclear cells. The propagated virus stocks were intravenously inoculated into respective macaque species. SHIV-TH09V3 infected both macaque species as shown by plasma RNA viremia, isolated viruses from PBMCs and plasma, and antibody production against viral proteins. To assess how the substituted V3 sequence affected coreceptor usage, SHIV-TH09V3 stocks propagated in vitro and after isolation from macaques were verified for their corecepor usage by GHOST cells assay. SHIV-TH09V3 maintained R5-tropic phenotype both in vitro and after isolation from macaques, in contrast to the X4/R5-dual tropic SHIV(MD14). This indicates the substituted V3 sequence among the backbone of SHIV(MD14) governs coreceptor usage. Future study of infecting macaques with SHIV-TH09V3 and SHIV(MD14) will focus on differences of the outcome caused by the different V3 sequences in connection with coreceptor usage.

Amino Acid Sequence↗

PubMed2003

Sequence and genetic arrangement of the UL region of the monkey B virus (Cercopithecine herpesvirus 1) genome and comparison with the UL region of other primate herpesviruses.

The complete DNA sequence of the unique long (U(L)) region of monkey B virus (BV) was determined. Based on sequence homology and the presence of transcriptional control element motifs, homologues of every open reading frame present in the U(L) region of the Human herpesvirus 1 (herpes simplex virus 1, HSV-1) and Human herpesvirus 2 (herpes simplex virus 2, HSV-2) genomes were identified in BV. The BV genes are arranged in the same order and orientation as in HSV. These results demonstrate that the BV U(L) region is entirely co-linear with that of HSV-1 and HSV-2.

Animals↗

PubMed2003

Pathophysiology and prevention of loop stomal prolapse in the transverse colon.

We investigated both pathogenesis and prevention of loop transverse stomal prolapse. Seven patients with reducible prolapsed stoma were studied under fluoroscopy after staining the prolapsed stoma and the colon by barium medium while prolapsing or reducing the stoma with or without the stomal wall pressed on to the abdominal wall of fascial plane. All prolapses occurred in the distal limbs of the loop stoma with the distal transverse colons redundant. The prolapse started around the mucocutaneous suture with the stoma inflated and the colon in it depressed and proceeded in accordance with an addition of abdominal pressure, but did not occur by pressing of the stomal wall. Prolapse of transverse loop stoma occurs when redundant colon invades the stoma with an abdominal pressure. Stomal prolapse might be prevented by fixation of the colon to the fascia.

Aged↗

PubMed2003

Transvaginal anterior levatorplasty with posterior colporrhaphy for symptomatic rectocele.

BACKGROUND: We evaluated functional and morphological outcomes of transvaginal anterior levatorplasty with posterior colporrhaphy for symptomatic rectocele. METHODS: Ten women (median 68 years) underwent transvaginal anterior levatorplasty with posterior colporrhaphy for symptomatic rectocele. Symptoms and continence were monitored before and after surgery. Manovolumetric study and defecography were performed in 9 of 10 patients before and 3-6 months after surgery. Twenty-one females without anorectal diseases were used as controls in manovolumetric study. The patients were followed up after a median of 89 months (range, 3-103). RESULTS: Main symptoms (defecatory disorders in 9 patients, vaginal mass in 6, perineal discomfort in 2) disappeared after surgery. Six patients performed digitation preoperatively and gave up digitation on defecation after surgery. Stool incontinence disappeared in 4 of 5 preoperatively incontinent patients (Cleveland clinic score, 5-12) and continence score improved from 5 to 2 in the remaining patient. Three patients with urinary cough incontinence preoperatively did not experience incontinence after surgery but cough incontinence occurred occasionally in an 81-year-old patient postoperatively. Rectocele demonstrated on defecography disappeared postoperatively in all 9 patients who underwent defecography. High threshold volume and maximum tolerable volume, which were observed preoperatively, decreased to control levels after surgery. CONCLUSION: Transvaginal anterior levatorplasty with posterior colporrhaphy might be an option for symptomatic rectocele to improve anorectal and urinary dysfunctions with morphological disorders.

Aged↗

PubMed2003

Bladder and male sexual functions after autonomic nerve-sparing TME with or without lateral node dissection for rectal cancer.

BACKGROUND: We evaluated to what extent lateral lymph node dissection (LND) interferes with bladder and male sexual functions after radical rectal excision with adoption of careful total autonomic nerve preservation. METHODS: The study comprised 77 patients resected for mid-rectal or lower rectal cancer. Bladder and male sexual functions were studied by means of a questionnaire more than one year after surgery. Outcomes were compared between patients who received lateral LND (group 1, 65 patients) and those who did not (group 2, 12 patients). RESULTS: Only minor disturbances of bladder function were reported in 10 patients (15%) of group 1, and in 3 patients (25%) of group 2. Ten out of 37 preoperatively sexually active patients (27%) in group 1 males and one of 5 patients (20%) in group 2 males had partial or total impotency after surgery and retrograde ejaculation occurred in 3 of 27 patients (11%) and one of 4 patients (25%), respectively. Erectile impotency occurred less frequently when patients were operated during the period 1993-1996 than during 1988-1992 (11% vs. 42%, p<0.05). The age was significantly greater among patients who had loss of ejaculation. CONCLUSIONS: If lateral lymph node dissection should be used with the aim of improving radicality in rectal excision for cancer, it should be combined with careful nerve-preserving technique--which may reduce the risk of bladder and male sexual dysfunctions.

Adult↗