Biomedical subjects

K Ueda

Publications and source records attributed to K Ueda.

At least 199 records · Page 11Linked to original sources

PubMed1996

Erythropoietin in mouse avascular yolk sacs is increased by retinoic acid.

Erythropoiesis begins first in the visceral yolk sac (VYS) of the embryo; however, the involvement of erythropoietin (EPO) in yolk-sac erythropoiesis has not been studied adequately. This study reports the expression of EPO in normal and hypoxic VYSs and alterations in yolk sac components induced by retinoic acid (RA) in mice. Gravid mice (plug day = day 0 of gestation) were given one oral dose of 60 mg/kg of RA in olive oil on days 6, 6.5, 7, 7.5, or 8 of gestation and were sacrificed 2.5, 3, or 3.5 days later. Control mice received olive oil without RA. None of the dams developed anemia, but more than 80% of the embryos of the dams that received RA on day 6, 6.5, or 7 of gestation had avascular yolk sacs (AVYs) and anemia. In these AVYs, the adenosine triphosphate (ATP) level was as low as 18-59% of that in the control VYSs. Reverse transcription-polymerase chain reaction and Southern analysis of products demonstrated that mRNA for EPO receptor (EPR) was expressed in both VYSs and AVYs on days 9-11 of gestation, and EPO mRNA was present in VYSs and AVYs on days 9 and 10 of gestation and in vehicle-exposed VYSs on day 11 of gestation. Furthermore, enzyme immunoassay of EPO indicated that AVYs contained more EPO protein than control VYSs. Light microscopy revealed that, in AVYs, in addition to the defective hemopoietic cells, the endodermal layer was exclusively altered: The presence of focal proliferated regions and the separation from the mesenchyme led to a single layer from which some immature cells seemed to be migrating. Immunolocalization of EPO showed its presence in all components of VYSs with a characteristic distribution pattern: In the endodermal layer, cells with positive EPO staining decreased as gestation advanced, and erythroid precursor cells showed positive staining. In AVYs, the proliferated endodermal cells had EPO in abundance; in the separated regions, the distinction between positive and negative EPO staining became clearer than that in the control VYSs, and the immature cells in the lumens also had EPO. EPR was seen on the cell surface of the corresponding cells that reacted to EPO. These findings suggest that VYSs not only produce EPO temporarily but also respond to the oxygen content in situ. EPO and EPR appear to be synthesized in the endodermal cells of the VYSs that are likely to respond to the circumstances induced by RA.

Adenosine Triphosphate↗

PubMed1996

The effect of hydration upon the conformation and dynamics of neocarrabiose, a repeat unit of beta-carrageenan.

Molecular mechanics calculations have been performed for the disaccharide neocarrabiose, one of the repeat units of beta-carrageenan, as a general model for the (1-->3)-linkage in the carrageenans. An adiabatic conformational energy map for this molecule has been prepared by constrained energy minimization and compared to previously reported relaxed maps. Neither the experimentally determined crystal structure of neocarrabiose nor the fiber diffraction conformation of iota-carrageenan is a low energy conformation on the relaxed Ramachandran map. Molecular dynamics simulations in vacuum produced trajectories consistent with this relaxed vacuum surface. However, a simulation with explicitly included solvent water molecules produced a trajectory that remained in the region of the two experimental structures. This dramatic solvation effect is apparently the result of the breaking of an interring hydrogen bond between the O2 hydroxyl groups of neocarrabiose as both groups hydrogen bond to solvent.

Carbohydrate Conformation↗

PubMed1996

Secondary contour reconstruction of maxillectomy defects with a bone graft vascularized by flowthrough from radial vascular system.

We describe post-total maxillectomy secondary facial contour reconstruction using an osteocutaneous scapular flap nourished by flow-through vascularization from the radial vascular system. Scar contracture caused by either total or partial maxillectomy for maxillary cancer was completely released with exposure of the edge of the zygomatic arch, orbital floor, and nasal bone. The scapular skin flap was placed into the mucosal defect, and the orbital floor and zygomatic prominence were reconstructed with the scapular bone. The flap nutrient vessels were anastomosed to radial vessels and cephalic vein grafts. Two representative cases are illustrated to demonstrate the application and advantage of this operative method.

Anastomosis, Surgical↗

PubMed1996

Comparison of end-to-end and end-to-side venous anastomosis in free-tissue transfer following resection of head and neck tumors.

A comparative study was conducted of the results of venous end-to-end and end-to-side anastomosis in 948 clinical cases of microvascular free-tissue transfers for head and neck reconstruction following tumor resection. End-to-side anastomosis to the internal jugular vein was achieved uneventfully in the present series, while a variety of recipient veins was used for end-to-end anastomosis. The incidence of thrombosis was 1.8% (15/835) in the end-to-end anastomosis group and 2.7% (3/113) in end-to-side venous anastomosis. No statistical difference was observed between the two groups. One may hesitate to perform end-to-side anastomosis because of unfamiliarity, concern over technical difficulty, and unreliability. As a result of our statistical analysis, we are convinced that end-to-side anastomosis directly to the internal jugular vein, whenever available, is the preferred procedure in microvascular free-tissue transfers for reconstruction of the head and neck following tumor resection.

Adolescent↗

PubMed1996

Experience of a new surgical procedure for the treatment of unilateral obstructive lymphedema of the lower extremity: adipo-lymphatico venous transfer.

We report five cases of adipo-lymphatico venous transfer (ALVT) performed to treat unilateral obstructive lymphedema of the lower extremity. ALVT is a surgical procedure that utilizes the long saphenous vein and its surrounding lymphatic tissue from the unaffected limb for the treatment of lymphedema. Since ALVT does not necessitate anastomoses of lymphatic vessels, it can be performed regardless of the severity and duration of lymphedema, and stable long-term results can be obtained when the transferred lymphatic tissue shows viability.

Adipose Tissue↗

PubMed1996

Magnetoencephalographic analysis of rolandic discharges in benign childhood epilepsy.

We report the detailed analysis of the generator and propagation of rolandic discharges in benign childhood epilepsy with centrotemporal spikes by means of 37-channel magnetoencephalography with neuromagnetic three-dimensional dipole localization. Equivalent current dipoles of prominent negative sharp waves of rolandic discharges appeared as tangential dipoles in the rolandic region, positive poles being situated anteriorly. These equivalent current dipoles showed a relatively limited localization and regular directions compared with other components. Equivalent current dipoles of preceding small positive waves, positive waves following negative sharp waves, and negative slow waves appeared in the vicinity of negative sharp waves. Equivalent current dipoles of rolandic discharges were located around the generator of somatosensory evoked magnetic fields stimulated at the lower lip. These findings suggest that rolandic discharges are generated through basically a mechanism similar to that for the middle-latency components of somatosensory evoked responses.

Child↗

PubMed1996

Localization of DNA in the condensed interphase chromosomes of Euglena.

The localization of DNA in the condensed interphase chromosomes of Euglena was determined by immunoelectron microscopy. Deposits of gold particles that coincided with the localization of DNA followed threads that corresponded to the chromatin fibers. The threads were 55-80nm in diameter and were assumed to be supersolenoids. The localization of gold deposits on chromosomes that had been sectioned in various directions suggested that the chromatin fibers coiled around the surface of chromosomes, with a wide central axial region of the chromosomes remaining free of DNA. These findings are discussed in relation to current models of chromosomal structure.

Animals↗

PubMed1996

A human pancreatic islet inwardly rectifying potassium channel: cDNA cloning, determination of the genomic structure and genetic variations in Japanese NIDDM patients.

Ligand gated potassium channels, such as the ATP-regulated potassium channel, play crucial roles in coupling of stimuli to insulin secretion in pancreatic beta cells. Mutations in the genes might lead to the insulin secretory defects observed in patients with non-insulin-dependent diabetes mellitus (NIDDM). We isolated a cDNA encoding a putative subunit of a ligand gated potassium channel from a human islet cDNA library. The channel, which we designated hiGIRK2, appeared to be an alternative spliced variant and a human homologue of recently reported mbGIRK2, KATP-2/BIR1. Transcripts were detected in human brain and pancreas, but not in other tissues including cardiac muscle. The sizes of transcripts in the pancreas differed from those in the brain, suggesting tissue-specific alternative splicing and possible isoforms. We then isolated human genomic clones, determined the complete genomic structure and localized the gene to chromosome 21 (21q22). The gene was comprised of four exons and the protein was encoded by three exons. The entire coding region of the hiGIRK2 gene was scanned by polymerase chain reaction-single strand conformation polymorphism analysis in 80 Japanese NIDDM patients. We found five nucleotide substitutions; three were silent mutations of the third base of codons, one in the first intron, 9 bases upstream of exon 2, and one in the 3'-untranslated region. We conclude that mutations in the gene encoding hiGIRK2, a (subunit of) ligand gated potassium channel, is not a major determinant of the susceptibility to NIDDM in Japanese.

Alternative Splicing↗

PubMed1996

Interferon-alpha therapy for multiple hemangiomas associated with coarctation of the aorta.

We report a rare combination of multiple hemangiomas and coarctation of the aorta in a 2-month-old female infant who responded to interferon-alpha (IFN-alpha) therapy. The coarctation was repaired successfully with the use of an artificial graft. In patients with symptomatic hemangiomas that do not respond to steroid therapy, IFN-alpha therapy should be considered.

Antineoplastic Agents↗

PubMed1996

IS431mec-mediated integration of a bleomycin-resistance gene into the chromosome of a methicillin-resistant Staphylococcus aureus strain isolated in Japan.

A methicillin-resistant Staphylococcus aureus (MRSA) strain B-26, isolated clinically in Hiroshima University Hospital, is resistant to bleomycin together with kanamycin. In the present study, we analysed the nucleotide sequence of the 5.1-kb HindIII fragment containing the bleomycin- and kanamycin-resistance genes, which were previously cloned [Bhuiyan et al. (1995) Appl Microbiol Biotechnol 43: 65-69] from the chromosomal DNA of MRSA B-26. The present study found that the DNA sequence contains the duplicated target sequence (GATTAGAT) consisting of 8 bp for transposase and the entire nucleotide sequence of the plasmid pUB110, together with the sequence of inverted repeats (16 bp), designated IR-r and IR-1 in IS431 mec. The 8-bp duplication sequence, produced by the transposable element, was first found by us. We proposed that bleomycin resistance in MRSA B-26 is attributed to the IS431 mec-mediated integration of pUB110 into the chromosome.

Bacterial Proteins↗

PubMed1996

Disadvantages of muscle-sparing thoracotomy in patients with lung cancer.

At our institute patients with lung cancer had traditionally undergone lobectomy with mediastinal lymph node dissection using a standard posterolateral approach. The considerable morbidity associated with the standard posterolateral thoracotomy led us to investigate an alternative muscle-sparing approach. A prospective, randomized study of 30 patients with primary lung cancer (stage I or II) was performed to compare the following: operative field size, number of dissected lymph nodes, surgery time, postoperative pain, shoulder range of motion, and pulmonary function test results between patients who underwent either standard thoracotomy (SP group, n = 15) or the muscle-sparing thoracotomy (MS group, n = 15). The procedure should provide enough operative field size to access to mediastinum. Compared with the standard posterior thoracotomy, the muscle-sparing thoracotomy supplied a smaller operative field (218 +/- 31 versus 165 +/- 41 cm2) and required more surgery time (87 +/- 13 minutes) than the standard posterior thoracotomy (66 +/- 12 minutes). There were no significant differences in the number of dissected mediastinal lymph nodes. During the early postoperative days, pain and restriction of shoulder flexion were significantly less in the MS group than in the SP group. There were no significant differences in pulmonary function between the two groups. In terms of the operative field there is a marked disadvantage with the muscle-sparing incision compared with standard thoracotomy. The operative field is significantly smaller than with a standard thoracotomy, requiring more time to dissect the mediastinum; however, the pain is less and shoulder range of motion is superior to what is seen after standard thoracotomy during the early postoperative period. We conclude that there is no overall advantage to using the muscle-sparing incision in patients with lung cancer.

Female↗

PubMed1996

Malignant neoplasms in the Japanese community of Hisayama: mortality and changing pattern during a 30-year observation period based on a consecutive autopsy series.

To obtain a relatively true mortality from malignant neoplasms, we studied the frequency of cancers in the different sites and the changing patterns of the frequency and sites over time among residents of the community of Hisayama, where an autopsy-based population survey (autopsy rate, 80%) has been conducted since 191. During the 30-year period from 1962 to 1991, we found 438 malignant neoplasms in 407 cases among 1,250 consecutive autopsies. Stomach cancer was not frequent in type of cancer, with 123 cases (9.8%), followed by lung cancer in 62 (5.0%), colorectal cancer in 42 (3.4%), liver cancer in 37 (3.0%), and pancreatic cancer in 30 (2.4%). We compared the mortality from cancers for both autopsy and nonautopsy cases (the proportional mortality) among three 10-year periods. The proportional mortality from all cancers, as well as for lung, colorectal, and liver cancers, showed an increase in recent years, while stomach and pancreatic cancer showed a decrease. These figures were nearly similar to the mortality statistics for the Japanese population as a whole except for the observed decreasing trend in mortality from pancreatic cancer.

Adolescent↗

PubMed1996

Attenuation of cardiotoxicity of daunomycin using a complex with heparin.

Daunomycin (DM) is one of the most important antitumor agents. However, the cardiotoxicity of DM limits it's clinical use. We have made an ionic complex with heparin to decrease the cardiotoxicity. Cardiotoxicities of DM and DM-heparin complex were compared in hamsters. On the electrocardiogram (ECG), two of the four hamsters given DM showed the serious abnormality, bidirectional ventricular premature contraction, while the hamsters given DM-heparin or saline had no abnormalities. On pathological examination, cardiac tissue in hamsters given DM showed deposition of basophilic materials, mild eosinophilic change of myofibrils and microvascuolization, whereas no change was observed in hamsters given DM-heparin complex or saline. Acute toxic effects on survival rates and body weights were more profound in DM-infused mice than in DM-heparin-infused mice. DM and DM-heparin complex showed similar anticancer activity both in vivo and in vitro. Thus, the present study suggests that the DM-heparin complex may attenuate the cardiotoxicity of DM without affecting it's antitumor effect in humans.

Animals↗

PubMed1996

Mass screening for neuroblastoma: quo vadis? A 9-year experience from the Pediatric Oncology Study Group of the Kyushu area in Japan.

Since 1985, a nationwide program of mass screening for neuroblastoma has been available for 6-month-old infants throughout Japan. From 1985 to 1993, the authors studied 285 patients with neuroblastoma among their regional population of 15 million. There was an increase in the total number of patients per year in comparison to the previous 6-year period (1979 to 1984). However, no significant difference was noted in the number of patients older than 1 year or in the incidence of advanced-stage (stages III and IV) unscreened cases. The majority of neuroblastomas in the screened group showed favorable biological factors, even in the advanced stages. However, there was a small group with histologically and/or biologically unfavorable factors; five of 115 had amplified N-myc oncogene, four of 74 showed unfavorable Shimada histological findings, and three of 33 had an unfavorable DNA ploidy pattern. One case from this group with unfavorable factors died of the tumor. 3) Thirty-eight cases were negative at the time of mass screening, but later presented with neuroblastoma. Most of them were diagnosed between 1 and 3 years of age, and 30 of the 38 cases (78.9%) were advanced stage with unfavorable prognostic factors. Thus, the authors conclude that mass screening at 6 months can detect a selected population of infants with neuroblastoma; some of the tumors may represent subclinical masses destined for spontaneous regression. However, some tumors with unfavorable factors have been detected by mass screening before progression and/or dissemination. Infants in this group are considered to benefit most from early diagnosis and treatment.

Adolescent↗

PubMed1996

Reference intervals for serum granulocyte colony-stimulating factor levels in children.

OBJECTIVE: To determine age-adjusted reference intervals for children for serum granulocyte colony-stimulating factor (G-CSF) levels. DESIGN: We determined the serum G-CSF levels of 168 disease-free children who were term neonates to 15 years of age with a highly sensitive chemiluminescent enzyme immunoassay. RESULTS: The lowest values (5 ng/L) exceeded the detectable limit (1 ng/L) of this assay technique. The G-CSF levels were highest on the day of birth (mean +/- SD 147 +/- 146 ng/L); thereafter values decreased to 46 +/- 33 ng/L in the early neonatal period and to 23 +/- 10 ng/L in the late neonatal period. The G-CSF levels both on the day of birth and in the early neonatal period were significantly higher than in all older age groups. No significant differences were found among any of the age groups after 4 weeks of age. The G-CSF values were correlated with both blood leukocyte counts (r = 0.496, p < 0.0001) and neutrophil counts (r = 0.547, p < 0.0001). In children older than 4 weeks of age (n = 128), the 95% reference interval for G-CSF values was 5 to 42 ng/L. CONCLUSIONS: Our study in disease-free children revealed that change in serum G-CSF levels are age dependent and are correlated with neutrophil counts. Determination of reference intervals for the neonatal period requires further study.

Adolescent↗

PubMed1996

Effect of cyclosporin analogues and FK506 on transcellular transport of daunorubicin and vinblastine via P-glycoprotein.

PURPOSE: P-glycoprotein-mediated transcellular transport of anticancer agents and the inhibitory effect of cyclosporin analogs and FK506 were investigated. METHODS: The transcellular transport of daunorubicin and vinblastine by monolayers of LLC-GA5-COL150 cells which overexpressed P-glycoprotein was measured in the presence and absence of cyclosporins or FK506. RESULTS: Cyclosporins and FK506 inhibited P-glycoprotein-mediated transport of daunorubicin and vinblastine in the order of cyclosporin D, dihydrocyclosporin D > cyclosporin A > FK506 > cyclosporin C, dihydrocyclosporin C. The intracellular accumulation of the anticancer agents was highly associated with the transporting function of P-glycoprotein. The inhibitory effect of cyclosporin D was concentration-dependent. The inhibitory effect of the modulators on P-glycoprotein was not correlated with the immunosuppressive activity, but was correlated with their lipophilicity. CONCLUSIONS: In the transcellular transport system, lipophilicity may be one of the determinants for the inhibitory effect of various multidrug resistance modulators on the P-glycoprotein-mediated transport.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1996

Chronic myelomonocytic leukaemia with t(8;9)(p11;q34) in childhood: an example of the 8p11 myeloproliferative disorder?

We describe the case of a 10-year-old girl with chronic myelomonocytic leukaemia with the chromosomal translocation t(8;9)(p11;q34), who had developed tonsillar lymphoma as extramedullary involvement at the initial presentation. The cytogenetic study of the cells in both bone marrow and tonsils demonstrated t(8;9)(p11;q34), despite no malignant features in the bone marrow specimens. She developed acute leukaemic transformation 8 months after diagnosis during chemotherapy for lymphoma. Although etoposide reduced the number of blasts, t(8;9)(p11;q34)-bearing cells were not eradicated. Complete remission was obtained following an unrelated bone marrow transplantation. The clinical characteristics of this patient are similar to those of the patients with t(8;9)(p11;q34 or q32) or t(8;13)(p11;q11 or q12) reported previously. The unusual progression of the disease might be associated with the presence of (8;9)(p11;q34), suggesting a part in the 8p11 myeloproliferative syndrome.

Child↗

PubMed1996

Temporoparietal sandwich technique in acute avulsion injury of the hand.

In degloving injuries of the hand, rehabilitation can be delayed due to poor wound healing and partial flap necrosis, if the avulsed tissue is sutured back primarily. By sandwiching a temoroparietal fascial flap between the avulsed flap and the tendons, rehabilitation can be started immediately, even if flap necrosis is present.

Accidents, Occupational↗