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Biomedical subjects

Y Abe

Publications and source records attributed to Y Abe.

At least 37 records · Page 2Linked to original sources

Local ordering in the pseudogap state of the high-Tc superconductor Bi2Sr2CaCu2O(8+delta).

We report atomic-scale characterization of the pseudogap state in a high-Tc superconductor, Bi2Sr2CaCu2O(8+delta). The electronic states at low energies within the pseudogap exhibit spatial modulations having an energy-independent incommensurate periodicity. These patterns, which are oriented along the copper-oxygen bond directions, appear to be a consequence of an electronic ordering phenomenon, the observation of which correlates with the pseudogap in the density of electronic states. Our results provide a stringent test for various ordering scenarios in the cuprates, which have been central in the debate on the nature of the pseudogap and the complex electronic phase diagram of these compounds.

Journal Article↗

Surgery for Dupuytren's disease in Japanese patients and a new preoperative classification.

The surgical outcome of Dupuytren's disease was evaluated in 73 hands of 57 patients in a Japanese population. Subtotal fasciectomy was performed in all cases. Surgical results were evaluated using the percentage improvement of extension in each finger joint. Statistical analyses were performed on the risk factors associated with recurrence and extension. The surgical outcome depended on the degree of contracture of the proximal interphalangeal joint. Recurrence of disease occurred in eight patients (14%) and extension occurred in nine (16%). Recurrence and extension frequently occurred in those who had ectopic lesions or involvement of the radial side of the hand. The present results suggested that the Dupuytren's diathesis had an influence on recurrence and extension. We proposed a new classification of Dupuytren's disease that might help to predict the surgical outcome and facilitate surgical planning.

Adult↗

Dupuytren's disease on the radial aspect of the hand: report on 135 hands in Japanese patients.

We studied 135 hands in 77 Japanese patients to assess the frequency of radial involvement and its association with recurrence and the Dupuytren's diathesis. The radial aspect of the hand was affected in 22% of the hands. Diseased cords were observed in ten patients who underwent surgery on the radial aspect of the hand. Longitudinal cords on the radial side of thenar eminence and distal transverse interdigital cords were common. The radial aspect of the hand was the most common site of disease extension, though recurrence never occurred after excision of a radial lesion. Ectopic lesions, bilateral hand involvement, and recurrence were significantly more frequent in patients with the radial side involvement. Thus the results of this study suggest that radial side disease is associated with the Dupuytren's diathesis and is a risk factor of recurrence.

Adult↗

An objective method to evaluate the risk of recurrence and extension of Dupuytren's disease.

This study was undertaken to assess the influence of the factors related to Dupuytren's diathesis on the rates of recurrence and extension of Dupuytren's disease after surgery. The records of 65 patients who underwent surgery for Dupuytren's disease were retrospectively studied and the presence of factors related to diathesis were recorded. The sensitivity and specificity of each factor for predicting recurrence and extension were calculated. Odds ratios and 95% confidence intervals were also calculated and a discriminant analysis was performed to explore correlations between recurrence and extension and the significant variables. Our results confirmed the prognostic value of diathesis. The results have been used to develop a new scoring system for evaluating the risk of recurrence and extension.

Adult↗

Urinary leukotriene E4 in Henoch-Schonlein purpura.

BACKGROUND: Children with Henoch-Schonlein purpura (HSP) occasionally have allergic disease. We have previously shown that pranlukast hydrate was effective for purpura in HSP. Pranlukast hydrate is a leukotriene (LT) receptor antagonist; therefore, it is likely that LTs take part in the cause of HSP. Urinary leukotriene E4 (LTE4u) levels are a useful index of whole-body cysteinyl LT production in vivo. In this study, LTE4u was examined in children with HSP. OBJECTIVE: The purpose of this study was to examine the relation between the level of LTE4u and the cause of HSP. METHODS: Eighteen HSP children (six boys and 12 girls) and six healthy children were enrolled. RESULTS: LTE4u levels in patients with HSP were significantly higher (P< 0.05) at the onset than those in healthy children. Four weeks therapy with pranlukast hydrate lowers LTE4u levels in patients with HSP (P< 0.05). There were no differences in LTE4u between the group of HSP patients with purpura nephritis and the group of HSP patients without purpura nephritis. CONCLUSION: These results indicate that csyteinyl LTs may play a role in the pathophysiology of purpura in HSP.

Adolescent↗

Excision of pseudotumour in a patient with haemophilia A and inhibitor managed with recombinant factor VIIa.

We describe a patient with haemophilia A and factor VIII inhibitor who underwent surgical excision of a large pseudotumour in the left femoral region. Haemostasis was successfully maintained with bolus doses of recombinant factor VIIa at 2-h intervals and anti-fibrinolytic therapy, and the pseudotumour was removed. Subsequently, the dose interval was gradually prolonged to 8 h for a total of 18 days. Although a spontaneous haemorrhage was observed on postoperative day 8, haemostasis was achieved by reducing the dosage interval. No adverse event occurred during the course of treatment.

Blood Coagulation Factor Inhibitors↗

Effect of saliva on an antimicrobial tissue conditioner containing silver-zeolite.

The purpose of this study was to evaluate the influence of human saliva on the antimicrobial effect of a tissue conditioner containing an antibiotic agent, silver-zeolite. Samples of each tissue conditioner with or without silver-zeolite were prepared and a plastic disk was used as a control. Candida albicans and nosocomial respiratory infection-causing bacteria, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa and the Streptococcus milleri group (S. constellatus and S. intermedius), were selected as test microorganisms. Antimicrobial effects of samples after water or saliva immersion for 28 days were evaluated by counting the number of viable cells [colony forming unit (CFU)] in each microbial suspension (100 microL). All data were statistically analysed by one-way anova and Bonferroni's test (P < 0.05). The antimicrobial effects of samples with silver-zeolite immersed in saliva against C. albicans, S. aureus and MRSA were observed while CFU of P. aeruginosa indicated no significant difference from that of the control. As for the S. milleri group, its CFU after saliva immersion showed the significantly smaller value than that of the control. It is concluded that the antimicrobial effects of samples containing silver-zeolite against all tested microbes except for P. aeruginosa and the S. milleri group are not influenced by saliva immersion for 28 days.

Anti-Bacterial Agents↗

Flexor tendon sheath ganglion: analysis of 128 cases.

A 30-year analysis of 128 patients with flexor tendon sheath ganglion was investigated. The majority of patients were females with sex ratio of 2.6 : 1. Most of the patients are in their third to fifth decade of life. Hand dominance, previous trauma as well as other illnesses involving the hand did not show any correlation to the formation of ganglion. The middle finger was most commonly affected and 69% of the ganglion were located on A1 and A2 pulley. Recurrence was high (89%) after multiple percutaneous puncture and treatment was successful with no cases of recurrence after surgical excision.

Adolescent↗

IL-1alpha stimulates cathepsin K expression in osteoclasts via the tyrosine kinase-NF-kappaB pathway.

Interleukin-1alpha (IL-1alpha) is a powerful activator of osteoclast cells. However, the underlying mechanism for this activation is unknown. In this study, we reveal that IL-1alpha up-regulates the expression of cathepsin K protein, a key protease in bone resorption, by five-fold. Northern blot analysis and promoter analysis show that this induction occurs at the transcriptional level, in a dose-responsive and time-dependent manner. No increase in expression occurs in the presence of either pyrrolidine dithiocarbamate (PDTC), a selective inhibitor of NF-kappaB, or Genistein, a protein tyrosine kinase inhibitor, suggesting that IL-1alpha up-regulation may be via the tyrosine kinase-NF-kappaB pathway to regulate cathepsin K expression. Antisense oligonucleotides to p65, but not the p50 subunit of NF-kappaB, suppress the IL-1alpha-induced expression of cathepsin K. We therefore conclude that IL-1alpha up-regulates cathepsin K gene expression at the transcription level, and this regulation may be via the tyrosine-kinase-NF-kappaB pathway.

Animals↗

[Esophageal leiomyoma enucleated under the thoracoscopy; report of a case].

We report a case of a 40-year-old male with a posterior mediastinal mass that was 8 cm in size and located behind the trachea. The thoracoscopic surgery was performed. The tumor was located from the level of left brachiocephalic vein to the carina. The mediastinal pleura over the tumor was longitudinally opened by cautery-scissors. The azygos vein lying over the tumor was divided by means of an endoscopic stapler. The muscular layer of the esophagus was also longitudinally opened. The tumor was enucleated. Then, the dissected proper muscle layer of the esophagus was suture-closed. The postoperative course was uneventful. On the first postoperative day Gastrografin was swallowed, showing the absence of leaks. The patient was discharged on the fourth postoperative day. The advantages of the thoracoscopic surgery are as follows: rapid, full recovery of the patient; decreased postoperative pain; short postoperative hospital stay. Esophageal leiomyoma in selected patient was suitable for thoracoscopic enucleation.

Adult↗

A chitinase with high activity toward partially N-acetylated chitosan from a new, moderately thermophilic, chitin-degrading bacterium, Ralstonia sp. A-471.

A moderately thermophilic bacterium, strain A-471, capable of degrading chitin was isolated from a composting system of chitin-containing waste. Analysis of the 16S rDNA sequence revealed that the bacterium belongs to the genus Ralstonia. A thermostable chitinase A ( Ra-ChiA) was purified from culture fluid of the bacterium grown in colloidal chitin medium. Purification of the enzyme was achieved mainly by exploiting its binding to the colloidal chitin. The molecular mass of the enzyme was estimated to be 70 kDa and the isoelectric point approximately 4.7. N-terminal amino acid sequencing revealed a sequence of ADPYLKVAYYP, which had high homology (66% identity) with that of chitinase A1 from Bacillus circulans WL-12. The pH and temperature optima were determined to be 5.0 and 70 degrees C, respectively. The enzyme was classified as a retaining glycosyl hydrolase and was most active against partially N-acetylated chitosans. Its activities towards the partially N-acetylated chitosans, i.e. chitosan 7B, chitosan 8B, and chitosan 9B, were about 11-fold, 9-fold, and 5-fold higher than towards colloidal chitin, respectively. Ra-ChiA cleaved (GlcNAc)6 almost exclusively into (GlcNAc)2. Activation of Ra-ChiA was observed by the addition of 1 mM Cu2+, Mn2+, Ca2+, or Mg2+. Degradation of the partially N-acetylated chitosan produced oligosaccharides with a degree of polymerization ranging from 1-8; these are products that offer potential application for functional oligosaccharide production.

Chitin↗

Characterization of pNI10 plasmid in Pseudomonas, and the construction of an improved Escherichia and Pseudomonas shuttle vector, pNUK73.

The complete nucleotide sequence of pNI10 (3.75 kb), from which pNI105 and pNI107 were constructed as medium-host-range vectors for Gram-negative bacteria, was determined. A fragment of about 2.1 kb of pNI10 was essential for replication in Escherichia coli and Pseudomonas fluorescens. This fragment encodes a putative origin of replication ( ori) and one putative replication-controlling protein (Rep). An improved version of the medium-host-range plasmid vector pNUK73 (5.13 kb) was constructed with the basic-replicon of pNI10 and pHSG298 (2.68 kb). We show that expression in pseudomonads of the bromoperoxidase gene ( bpo) of Pseudomonas putida, inserted downstream of the lac promoter in pNUK73, resulted in about 30% (13.6 U/l culture) of the enzyme level obtained in E. coli.

Amino Acid Sequence↗

Acid pretreatment of titanium implants.

The purpose of this study was to evaluate the effectiveness of several methods of cleaning titanium surfaces as pretreatment for surface modifications by analyzing the chemical interaction of three acids, such as Na(2)S(2)O(8),H(2)SO(4) and HCl, followed by rinsing with acetone or ultrapure water. Chemical evaluation, using X-ray photoelectron spectroscopy (XPS), and mechanical evaluation, using nanoindentation, were employed. XPS revealed that an untreated Ti surface consisted of carbon- and nitrogen-containing contaminant and titanium oxide layer on metallic titanium substrate. The method involving the combination of 10 N HCl and acetone was the most effective of all the methods investigated. Such a combination most effectively reduced values of contamination parameters C/Ti and N/Ti, as well as the intensity of the titanium oxide component in Ti 2p spectra. Chlorine was barely detected from the surface treated with HCl in any concentration. Sulfur from the residual S(2)O(8)(2-) or SO(4)(2-), however, was detected from the samples treated with either Na(2)S(2)O(8) or H(2)SO(4). The S/Ti values depended on concentration of the acidic solution. In addition, nanoindentation measurements revealed that Young's modulus of the surface treated with 0.1-10 N HCl was not significantly different from that of an untreated surface (p > 0.05). Consequently, the HCl/acetone treatment is proposed as an excellent decontamination method for the surface preparation process of Ti.

Acids↗

Miniature vibrating flow blood pump using a cross-slider mechanism for external shunt catheter.

The prototype of the miniature vibrating flow pump (VFP) is developed for the external shunt catheter. The cross-slider mechanism is applied to vibrate the tube, which causes the pumping effect. This mechanism results in successful development of the miniature and lightweight VFP. By the use of the prototype VFP, the experiment of the basic pump performance is made in detail based on the authorized procedure in the research field of fluids engineering. The typical H-Q curve of VFP, which is the relationship between the pump head and the flow rate, can be obtained. This result suggests that the miniature VFP developed here can be expected to be used as the booster pump for the external shunt catheter in clinical applications.

Arteriovenous Shunt, Surgical↗

Development of an implantable high-energy and compact battery system for artificial heart.

The purpose of this study was to demonstrate the feasibility of the use of an implantable, high-energy, and compact battery system for an undulation pump total artificial heart (UPTAH). The implantable battery system tested consists of six lithium-ion batteries in series, a charge unit, and a charge/discharge control unit. A lithium-ion battery is currently the best energy-storage device because it has more energy density, a better life cycle, and a smaller temperature rise than those of other secondary batteries. The performance of the implantable battery system was evaluated in an in vitro experiment using an electric load that simulated the UPTAH. Also, sufficiently reliable operation of a system for supplying energy to a UPTAH consisting of a transcutaneous energy transmission system (TETS) and an implantable battery system was confirmed in three experiments using goats. The results of the in vitro and in vivo experiments showed that the implantable battery system supplied sufficient current to the UPTAH for maintenance of physiological conditions in the goat with maximum rise in temperature to less than 43 degrees C.

Animals↗