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Biomedical subjects

Keisuke Kato

Publications and source records attributed to Keisuke Kato.

At least 19 recordsLinked to original sources

Concurrent Ewing sarcoma family of tumors and fibrous dysplasia: possible diagnostic pitfall.

We present 2 patients with synchronous Ewing sarcoma family of tumors (ESFTs) and fibro-osseous lesion in the independent sites, possibly causing misjudgment in staging. Each patient showed another activity apart from the primary ESFT lesion on gallium and/or thallium scintigraphy at initial presentation. Of note is that such lesions showed no obvious radiologic change even though the primary ESFT lesions were mildly shrunken during chemotherapy. The biopsies confirmed fibrous dysplasia (FD) in the first patient and fibro-osseous lesion, possibly FD in the second patient. As far as we know, concurrent ESFT and FD in independent sites have never been described. However, this unusual combination emphasized the possibility of concurrent FD mimicking metastasis in a patient with malignancy and the view that exploratory biopsy should be performed in a critical case to make staging. Further investigation will be required about whether the co-occurrence of ESFD and FD in our patients is coincidence or genetic linkage.

Adolescent↗

Dyspnoea at 6-min walk test in idiopathic pulmonary fibrosis: comparison with COPD.

The characteristics of dyspnoea in idiopathic pulmonary fibrosis (IPF) during a 6-min walk test are not clear. This study was designed to evaluate dyspnoea and desaturation during the 6-min walk test in IPF in comparison with that in chronic obstructive pulmonary disease (COPD), which is one of the most studied chronic lung diseases. The 41 consecutive patients with IPF included in this study were assessed by a 6-min walk test and concurrent measures of disease severity. Forty-one age-matched and resting PaO(2) value-matched COPD patients who had undertaken the test during the same period were selected as the control. Only O(2) saturation at the end of the test was an independent predictor of dyspnoea in IPF (r(2)=0.27, P=0.0005), whereas forced expiratory volume in 1s (FEV(1)) was the only predictor in COPD (r(2)=0.16, P=0.0096). Desaturation was significantly more severe in IPF (83.6+/-9.1% in IPF versus 88.0+/-5.9% in COPD, P<0.001). In contrast, dyspnoea assessed with the Borg scale was significantly more severe in COPD (3.6+/-2.1 in IPF versus 4.6+/-1.9 in COPD, P<0.05). O(2) saturation is an independent predictor of dyspnoea at the end of a 6-min walk test in IPF. In comparison with COPD, desaturation is more severe, although dyspnoea is milder.

Aged↗

Biodegradable network elastomeric polyesters from multifunctional aliphatic carboxylic acids and poly(epsilon-caprolactone) diols.

Biodegradable elastomeric network polyesters were prepared from multifunctional aliphatic carboxylic acids such as tricarballylic acid (Yt) or meso-1,2,3,4-butanetetracarboxylic acid (Xb) and poly(epsilon-caprolactone) (PCL) diols with molecular weights of 530, 1,250 and 2,000 g.mol-1. Prepolymers prepared by a melt polycondensation were cast from DMF solution and postpolymerized at 280 degrees C for various periods of times to form a network. The resultant films were transparent, flexible and insoluble in organic solvents. The network polyesters obtained were characterized by IR absorption spectra, WAXS, density measurement, DSC, and tensile test. YtPCL1250, and XbPCL1250 network polyester films showed good elastomeric properties with high ultimate elongation (540-590%), and low Young's modulus (2.5-3.3 MPa). The enzymatic degradation was estimated by the weight loss of network films in a buffer solution with Rhizopus delemar lipase at 37 degrees C. The degree and rate of degradation were significantly affected by the molecular weight of PCL diol, chemical structures of multifunctional aliphatic carboxylic acids and the morphology of network films. The changes in the solid states of network films during the degradation were also estimated by the results of DSC and WAXS. [see text]

Biocompatible Materials↗

Acute exacerbation of interstitial pneumonia following surgical lung biopsy.

STUDY OBJECTIVES: Surgical lung biopsy (SLB) plays an important role in the diagnosis of interstitial pneumonia, however, the occurrence of acute respiratory failure following SLB remains largely unreported. We evaluated the incidence, clinical features, therapy and prognosis of acute exacerbation of interstitial pneumonia following SLB. DESIGN: Retrospective study of consecutive patients who underwent SLB to establish a diagnosis of diffuse lung disease between May 1989 and April 2000. Patients with an acute exacerbation following lung biopsy were studied, and the HRCT images of the chest before and after surgery were reviewed. MEASUREMENTS AND RESULTS: Among the 236 consecutive patients with interstitial pneumonia who underwent a surgical lung biopsy, five (2.1%) (IPF, 3; NSIP, 1; COP, 1) developed acute exacerbation of the diffuse lung disease in the course of 1-18 days after SLB. The extent of parenchymal involvement on HRCT before surgery was not significantly different between operated and contralateral nonoperated lung. Significantly increased regions of parenchymal involvement on HRCT were seen postoperatively compared with the preoperative CT in both the operated (20.7+/-12.5% versus 38.2+/-10.8%, P = 0.0431) and nonoperated lung (22.7+/-13.8% versus 70.5+/-24.4%, P = 0.0431), but the extent of the parenchymal involvement was significantly greater on the nonoperated side (P = 0.0251). Two of the 3 IPF patients died from the acute exacerbation. CONCLUSIONS: It is important to be aware of the possibility of acute exacerbation of interstitial pneumonia following SLB even after an apparently uneventful immediate postoperative course. The asymmetric image findings suggest that intraoperative respiratory management is a possible etiologic factor.

Acute Disease↗

Congenital neuroblastoma in a patient with partial trisomy of 2p.

We report the fourth example of a patient with germline partial trisomy of 2p21-pter and congenital neuroblastoma. The male infant had a dysmorphic facial expression and presented with congenital heart disease, supernumerary nipples, hypospadias, shawl scrotum, hemilateral persistent hyperplastic primary vitreous, and neuroblastoma. His germline karyotype of 46,XY,der(8)t(2;8)(p21;p23.2) was inherited from a maternal-balanced translocation, which indicates that the proto-oncogene MYCN region of 2p24.3 is tripicated in germline cells. A cytogenetic study of the biopsied tumor cells did not show MYCN amplification, but the DNA index was 2.4 and histologic fluorescent in situ hybridization analysis indicated somatic mutation with near-pentaploidy of the tumor cells. This could be an alternative mechanism of MYCN activation in the process of the tumorigenesis of neuroblastoma.

Abnormalities, Multiple↗

Comparison of the effects of tulobuterol patch and salmeterol in moderate to severe asthma.

1. Although the clinical effects of the tulobuterol patch have been reported to include an increase in morning peak expiratory flow (PEF) values and a decrease of symptoms and the frequency of the rescue use of inhaled short-acting beta2-adrenoceptor agonists, no trials comparing the efficacy of the tulobuterol patch to other standard inhaled long-acting beta2-adrenoceptor agonists have yet been conducted. The aim of the present study was to compare the clinical effects of the patch formulation of tulobuterol with those of inhaled salmeterol in moderate to severe asthma. 2. Fifty-four patients with moderate to severe asthma, whose conditions were suboptimally controlled despite receiving inhaled corticosteroids, were recruited. The study was a prospective, randomized trial of cross-over design comparing the effects of 4 weeks treatment with tulobuterol patch, 2 mg once daily, and salmeterol, 50 mg twice daily. The mean prebronchodilator morning PEF during the last 14 days of each treatment period and health-related quality of life (HRQoL) were the primary outcome variables. The HRQoL was assessed using the St George's Respiratory Questionnaire. 3. Forty-four patients (81.5%) completed the trial and were included in the analysis. The mean morning PEF and HRQoL score were significantly improved in both the salmeterol (P < 0.0001 and P < 0.05, respectively) and the tulobuterol patch (P < 0.01 and P < 0.05, respectively) treatment periods compared with the run-in period. Although the mean morning PEF was significantly higher in the salmeterol-treated group than in the tulobuterol-treated group (P < 0.001), the HRQoL scores were comparable. 4. The tulobuterol patch may be useful as a controller medication in addition to inhaled corticosteroids in moderate to severe asthma.

Administration, Cutaneous↗

Gene mutation analysis and immunohistochemical study of beta-catenin in odontogenic tumors.

In the present study the significance of nuclear/cytoplasmic expression of beta-catenin (CTNNB1) and mutation of the CTNNB1 gene (CTNNB1) in odontogenic tumors was examined. Six ameloblastomas (five follicular ameloblastomas and one plexiform ameloblastoma) and three malignant odontogenic tumors (one metastasizing ameloblastoma, one ameloblastic carcinoma, and one primary intraosseous odontogenic carcinoma) were investigated for CTNNB1 expression and CTNNB1 mutation. Immunohistochemically, all follicular ameloblastomas and one primary intraosseous odontogenic carcinoma exhibited focal and moderate nuclear/cytoplasmic expression of CTNNB1, whereas the plexiform ameloblastoma and the remaining two malignant odontogenic tumors had entirely membranous expression. CTNNB1 mutation at codon 40 of exon 3 was found in one of the six follicular ameloblastomas. The other five follicular ameloblastomas, the plexiform ameloblastoma, and the three malignant odontogenic tumors did not show mutation in exon 3 of CTNNB1. These findings further confirmed that CTNNB1 mutation is not frequent in ameloblastoma and malignant odontogenic tumors, although the abnormality of Wnt signaling may be associated with some of these tumors.

Adolescent↗

[A case of Langerhans cell histiocytosis which resolved only on smoking cessation].

We report a case with Langerhans cell histiocytosis appearing as an extra-pleural tumor. A 20-year-old man was transferred to our hospital because of right chest pain and fever. His chest X-ray showed an extra-pleural mass and chest CT scan showed a mass lesion with right 7th rib fracture. 67Gallium and bone scintigram showed uptake at the same site. We performed a CT-guided puncture biopsy. Pathological findings of the specimen showed diffuse proliferation of histiocytoid cells with some eosinophils. The histiocytes were positive for S-100 protein and CD1a on immunohistochemical stain. Langerhans cell histiocytosis was diagnosed. There was no other involvement of the disease except the rib. The tumor resolved only with smoking cessation and no recurrence was observed during the follow-up period. An association between smoking and progressions of the rib disease was suggested.

Adult↗

[Quality of life as an independent prognostic factor in advanced non-small-cell lung cancer in general practice].

Although quality of life (QOL) has become an important aspect of lung cancer trials, it has rarely been evaluated in general practice. We have been assessing QOL in patients with advanced non-small-cell lung cancer in general practice. In this study, we retrospectively analyzed factors of the baseline QOL score in relation to response to chemotherapy and survival in 43 consecutive advanced non-small-cell lung cancer patients who received chemotherapy. QOL was evaluated with the QLQ-C30 of The European Organization for Research and Treatment of Cancer. In multivariate analysis, the cognitive functioning score was the only significant factor in both response to treatment and survival. In conclusion, the QOL score is an independent factor in both response to chemotherapy and survival even in general practice; and cognitive functioning is the most important factor.

Adult↗

[Surgical lung biopsy for interstital lung diseases: complications, diagnostic yield and mortality].

We retrospectively reviewed 110 consecutive patients with interstitial lung diseases (ILDs) who underwent surgical lung biopsy over 13 years from 1989-2002. Surgical procedures, medical records, surgical complications and outcome including post-operative exacerbation of ILDs were assessed in order to clarify the safety and efficacy of surgical lung biopsy. Forty-one patients underwent open lung biopsy (OLB), while 69 patients received videothoracoscopic lung biopsy (VTLB). There was no significant difference in patient characteristics, pulmonary function, arterial oxygen pressure and therapy prior to surgery between the two groups. The mean number of biopsy specimens was 2.5. Left side was selected as the site of biopsy in 70 cases. Duration of surgery was not significantly different between 2 groups. Bleeding during operation was less in the VTLB group than in the OLB group, although the mean bleeding amount was only 16.5mL. The duration of thoracic drainage and length of hospital stay were shorter in the VTLB group. The overall rate of surgical complications was 10.9%, with no difference between the two groups. The overall 30-day post-SLB mortality was 6.4% and majority of these had a very poor prognosis pathologically. The diagnostic yield of all 110 cases was 98.2%. SLB is a relatively safe and efficient diagnostic method in the diagnosis of ILDs.

Adult↗

[Case of acute respiratory distress syndrome in which high-frequency oscillatory ventilation (HFOV) was effective for the management of severe hypoxemia].

A 69-year-old man was admitted to our hospital because of acute prostatitis. After admission he produced bloody sputum and chest radiograph showed bilateral infiltration of the upper lung fields. The fraction of neutrophils in the bronchoalveolar lavage fluid was 15.6%, lymphocytes were 33.6%, eosinophils were 26.6% and macrophages were 23.6%. No special findings were observed in the lung tissue obtained by transbronchial lung biopsy. After admission, he displayed acute respiratory distress syndrome with severe hypoxemia as dyspnea gradually progressed. We commenced treatment with high-dose pulse methylprednisolone and neutrophil elastase inhibitor under mechanical ventilation. Because severe hypoxemia was unresolved, HFOV was initiated on the 8th hospital day. His respiratory condition rapidly improved during HFOV. On the 17th hospital day, he was weaned from mechanical ventilation. HFOV seem to be safe and effective for patients with severe ARDS who failed conventional ventilation support.

Aged↗

Identification of the reptilian prolactin and its receptor cDNAs in the leopard gecko, Eublepharis macularius.

In spite of their physiological significance, there is no available information about the nucleotide sequences of prolactin (PRL) and its receptor in reptilian species. In order to fill this gap, PRL and its receptor cDNAs were identified in a reptilian species, the leopard gecko Eublepharis macularius. The deduced leopard gecko PRL polypeptide showed high identities with the corresponding polypeptides of other reptiles. The leopard gecko PRL receptor (PRLR) was estimated to have tandem repeated regions in its extracellular domain, which had been originally found in avian PRLR. Molecular phylogenetic analysis suggests that these tandem repeated regions were generated by the duplication of the extracellular region in the latest common ancestor among reptiles and birds. In addition, tissue distributions of PRL and PRLR in the leopard gecko were examined by the reverse transcription-polymerase chain reaction (RT-PCR). PRLR mRNA was detected in all tissues examined and highly expressed in the whole brain, pituitary, intestine, kidney, ovary, oviduct and testis. Whereas, PRL mRNA was expressed in the whole brain, pituitary, ovary and testis. The co-expressions of PRL and its receptor in some extrapituitary organs suggest that PRL acts as an autocrine/paracrine factor in such organs of the leopard gecko.

Amino Acid Sequence↗

Synthesis of (+/-)-4'-ethynyl and 4'-cyano carbocyclic analogues of stavudine (d4T).

The synthesis of (+/-)-4'-ethynyl (8) and 4'-cyano (9) carbocyclic analogues of the anti-HIV agent stavudine (5, d4T) is reported. The carbocyclic unit (16) was constructed from readily available beta-keto ester 10. The ethynyl or cyano group of 8 and 9 were prepared, after the introduction of thymine base to 16, by manipulation of the ester function. Evaluation of the anti-HIV activity of 8 and 9 was also carried out.

Molecular Structure↗

Expression pattern of keratin subclasses in pancreatoblastoma with special emphasis on squamoid corpuscles.

Expression patterns of keratins (K), both simple epithelia-type (K7, K8, K18, K19) and complex/stratified epithelia-type (K1, K4, K5/6, K10, K13, K14, K15, K16, K17), and epithelial membrane antigen (EMA) were immunohistochemically studied in six pancreatoblastomas (PBL). In all six tumors, areas with overt acinar differentiation (AA), solid areas without any specific differentiation (SO), and squamoid corpuscles (SC) were diffusely positive for K8, K18, and K19. The AA and SO in all the tumors were diffusely positive for K7, but the SC were negative or displayed only scattered reactivity for K7. In three tumors, the AA and the SC showed scattered reactivity for K5/6. No reactivity for other complex/stratified epithelia-type K was found in any of the examined tumor. All tumors were reactive for EMA with consistent predominancy in the SC. Ultrastructurally, well-developed desmosome-tonofilament complexes were only partially observed in tumor cells comprising the SC. These results implied that (i) the SC usually lack a character of complete squamous metaplasia; and (ii) the SC have a characteristic phenotype (K8/K18/K19/EMA-positive, K7-negative or scatteredly positive) that can potentially be useful to delineate the SC in PBL.

Child↗

Chemoenzymatic synthesis of naturally occurring benzyl 6-O-glycosyl-beta-D-glucopyranosides.

Direct beta-glucosidation between benzyl alcohol and D-glucose (5) using the immobilized beta-glucosidase from almonds with the synthetic prepolymer ENTP-4000 gave a benzyl beta-D-glucoside (1) in 53% yield. The coupling of the benzyl beta-D-glucopyranoside congener (8) derived from 1 with phenyl 2,3,4-tri-O-acetyl-1-thio-beta-D-xylopyranoside (9), ethyl 2,3,4-tri-O-acetyl-1-thio-alpha-L-rhamnopyranoside (13), and 2,3,4-tri-O-acetyl-alpha-L-arabinopyranosyl bromide (15) afforded 10, 14, and 16, respectively, as coupled products. Deprotection of 10, 14, and 16 provided the synthetic benzyl beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranoside (2), benzyl alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (3), and benzyl alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside (4), respectively.

Carbohydrate Sequence↗

Pericardial hemangioma presenting fetal cardiac tamponade and postnatal bronchostenosis.

A case of pericardial hemangioma is described which was resected in the neonatal period due to its effect on the cardiopulmonary system. Preoperative differential diagnosis of a teratoma was difficult. Surgical extirpation resulted in massive bleeding and postoperative bronchomalacia. These complications suggest that we should choose a conservative therapy as often as possible.

Bronchi↗

Mechanistic studies of 1-aminocyclopropane-1-carboxylic acid oxidase: single turnover reaction.

The final step in the biosynthesis of the plant hormone ethylene is catalyzed by the non-heme iron-containing enzyme 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACCO). ACC is oxidized at the expense of O(2) to yield ethylene, HCN, CO(2), and two waters. Continuous turnover of ACCO requires the presence of ascorbate and HCO(3)(-) (or an alternative form), but the roles played by these reagents, the order of substrate addition, and the mechanism of oxygen activation are controversial. Here these issues are addressed by development of the first functional single turnover system for ACCO. It is shown that 0.35 mol ethylene/mol Fe(II)ACCO is produced when the enzyme is combined with ACC and O(2) in the presence of HCO(3)(-) but in the absence of ascorbate. Thus, ascorbate is not required for O(2) activation or product formation. Little product is observed in the absence of HCO(3)(-), demonstrating the essential role of this reagent. By monitoring the EPR spectrum of the sample during single turnover, it is shown that the active site Fe(II) oxidizes to Fe(III) during the single turnover. This suggests that the electrons needed for catalysis can be derived from a fraction of the initial Fe(II)ACCO instead of ascorbate. Addition of ascorbate at 10% of its K(m) value significantly accelerates both iron oxidation and ethylene formation, suggesting a novel high-affinity effector role for this reagent. This role can be partially mimicked by a non-redox-active ascorbate analog. A mechanism is proposed that begins with ACC and O(2) binding, iron oxidation, and one-electron reduction to form a peroxy intermediate. Breakdown of this intermediate, perhaps by HCO(3)(-)-mediated proton transfer, is proposed to yield a high-valent iron species, which is the true oxidizing reagent for the bound ACC.

Amino Acid Oxidoreductases↗