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Y Oshima

Publications and source records attributed to Y Oshima.

At least 37 records · Page 2Linked to original sources
PubMed2001

Two-generation reproductive toxicity study of tributyltin chloride in female rats.

A two-generation reproductive toxicity study of the effects of tributyltin chloride (TBTCl) was conducted in female rats using dietary concentrations of 5, 25, and 125 ppm TBTCl. Reproductive outcomes of dams (number and body weight of pups and the percentage of live pups) and the growth of female pups (the day of eye opening and body weight gain) were significantly decreased in the 125 ppm TBTCl group. A delay in vaginal opening and impaired estrous cyclicity were also observed in the 125 ppm TBTCl group. However, an increase in anogenital distance was found in all TBTCl groups on postnatal d 1. A dose-effect relationship was observed in TBTCl-induced changes in anogenital distance. These results indicate that the whole-life exposure to TBTCl affects the sexual development and reproductive function of female rats. In addition, the TBTCl-induced increase in anogenital distance seems to suggest it may exert a masculinizing effect on female neonates. However, the concentrations of TBTCl used in this study are not environmentally relevant.

Analysis of Variance↗
PubMed2001

Molecular cloning of tenomodulin, a novel chondromodulin-I related gene.

Murine expressed sequence tags (EST) showing homology with chondromodulin-I (ChM-I) were identified. Cloning of the full-length cDNA revealed a novel protein (317 amino acid residues) having a domain homologous to ChM-I, and we termed it tenodmoulin (TeM). The predicted amino acid sequence revealed 33% overall identity with mouse ChM-I precursor. Overall structural features were conserved well in TeM, including a single transmembrane domain at the N-terminal region and the putative antiangiogenic domain with eight cysteine residues. However, TeM lacked a hormone-processing signal present in the ChM-I precursor, suggesting that it may function as a type II transmembrane protein on cell surface. TeM transcript (1.4 kb in size) was detected in skeletal muscle by Northern blot analysis. In situ hybridization analysis revealed that the expression of TeM mRNA was not associated with muscle fibers, but was tightly associated with epimysium and tendon, both of which are classified as dense connective tissue having little vascularity.

Amino Acid Sequence↗
PubMed2001

Characterization of a powerful high affinity antagonist that inhibits biological activities of human interleukin-13.

Interleukin-13 (IL-13), a predominantly Th2-derived cytokine, appears to play a central pathological role in asthma, atopic dermatitis, allergic rhinitis, some parasitic infections, and cancer. We hypothesized that an IL-13 antagonist may have profound therapeutic utility in these conditions. We, therefore, mutagenized human IL-13 in which Glu at position 13 was substituted by a Lys residue. This highly purified recombinant IL-13 variant, IL-13E13K, bound with 4-fold higher affinity to the IL-13 receptor than wild-type IL-13 but retained no detectable proliferative activity on the TF-1 hematopoietic cell line. IL-13E13K competitively inhibited IL-13- and IL-4-dependent TF-1 proliferation. It also inhibited IL-13-induced STAT-6 (signal transduction and activator of transducer-6) activation in immune cells and cancer cells and reversed IL-13-induced inhibition of CD14 expression on human primary monocytes. These results demonstrate that high affinity binding and signal generation can be uncoupled efficiently in a ligand receptor interaction. These results also suggest that IL-13E13K may be a useful antagonist for the treatment of allergic, inflammatory, and parasitic diseases or even malignancies in which IL-13 plays a central role.

Amino Acid Sequence↗
PubMed2001

Virol A, a toxic trans-polyacetylenic alcohol of Cicuta virosa, selectively inhibits the GABA-induced Cl(-) current in acutely dissociated rat hippocampal CA1 neurons.

The effects of virol A (VA), a toxic component of Cicuta virosa (water hemlock), on the GABA-induced Cl(-) current (I(GABA)) in acutely dissociated rat hippocampal CA1 neurons were investigated using whole-cell patch-clamp techniques. VA reversibly reduced I(GABA) and the muscimol (Mus)-induced current (I(Mus)) in a concentration-dependent manner. The IC(50) values for VA against I(GABA) and I(Mus) were 9.6x10(-7) and 9.8x10(-7) M, respectively. VA shifted the EC(50) value of I(GABA) from 6.5x10(-6) to 2.1x10(-5) M, whereas it had no effect on the maximum response, thereby suggesting that VA inhibited I(GABA) in a competitive manner. VA had no apparent effect on current-voltage relationships for I(GABA), thus indicating the lack of voltage-dependency. On the other hand, application of VA (10(-6) M) did not additionally reduce the I(GABA) suppressed by >10(-5) M picrotoxin. VA but not bicuculline accelerated the decay phase of I(GABA), as was seen with picrotoxin. Moreover, pre-application of 10(-5) M VA reduced I(GABA). VA did not inhibit that induced by glycine (10(-4) M). These results indicate that VA inhibits I(GABA) by acting both on the GABA agonist site and on the Cl(-) channel of the GABA(A) receptor-channel complex. VA is a structurally novel type of compound that selectively inhibits the GABA(A) receptor-Cl(-) channel complexes in mammalian central nervous system neurons.

Animals↗
PubMed2001

Absolute configuration at C14 and C85 in prymnesin-2, a potent hemolytic and ichthyotoxic glycoside isolated from the red tide alga Prymnesium parvum.

Prymnesin-2 is a potent red tide toxin characterized by a highly oxidized C(90) carbon chain and multiple functional groups. Succeeding the assignment of the relative stereochemistry in the polycyclic-ether segment, the absolute configurations of two chiral centers in linear chain parts were elucidated. The configuration at C14 bearing an amino group was determined to be S by using a chiral anisotropic reagent and that at chlorinated C85 to be S by fluorimetric chiral HPLC comparison between a degradation product and synthetic references.

Animals↗
PubMed2001

Indocyanine green and fluorescein hyperfluorescence at the site of occlusion in branch retinal vein occlusion.

BACKGROUND: In patients with branch retinal vein occlusion (BRVO), we investigated the presence of indocyanine green (ICG) and fluorescein hyperfluorescence at the site of occlusion. We also assessed the association of this feature with the clinical outcome of these patients. METHODS: Both indocyanine green (ICG) videoangiography and fluorescein angiography (FAG) were performed in 21 eyes with BRVO of less than 1 month duration. Deterioration of the disease was defined clinically as an increase in retinal hemorrhages or retinal edema. Capillary nonperfusion was quantified with computer image analysis from the FAG pictures. RESULTS: ICG videoangiography showed focal hyperfluorescence along the venous wall at the site of the affected A-V crossing in 9 of the 21 eyes, and FAG showed this feature in 10 eyes. The ICG hyperfluorescence was more prominently and focally detected than the hyperfluorescence on FAG, which was sometimes diffusely seen throughout the whole occluded area. Eight of the nine eyes showing ICG hyperfluorescence had clinical deterioration with an increase in retinal hemorrhage or edema. This deterioration occurred more frequently in eyes with hyperfluorescence and/or late leakage than in ones without these features. The mean nonperfused area was significantly larger in eyes with hyperfluorescence than in eyes without these features. CONCLUSION: The ICG hyperfluorescence at the site of A-V crossing is associated with disease deterioration in patients with fresh BRVO. The ICG hyperfluorescence was more easily detectable than the hyperfluorescence on FAG, although the difference in sensitivity between the two methods is not great.

Adult↗
PubMed2001

Relocalization of apoptosis-inducing factor in photoreceptor apoptosis induced by retinal detachment in vivo.

Apoptosis-inducing factor (AIF) is a novel mediator in apoptosis. AIF is a flavoprotein that is normally confined to the mitochondrial intermembrane space, yet translocates to the nucleus in several in vitro models of apoptosis. To investigate the role of AIF in the apoptotic process in vivo, we induced retinal detachment (RD) by subretinal injection of sodium hyaluronate, either in Brown Norway rats or in C3H mice. Apoptotic DNA fragmentation, as determined by terminal nick-end labeling, was most prominent 3 days after RD. The subcellular localization of AIF was examined by immunohistochemistry and immunoelectron microscopy. In normal photoreceptor cells, AIF was present in the mitochondrion-rich inner segment. However, AIF was found in the nucleus after RD. Photoreceptor apoptosis developed similarly in C3H control mice, and in mice bearing the gld or lpr mutations, indicating that cell death occurs independently from the CD95/CD95 ligand system. Both the mitochondrio-nuclear transition of AIF localization and the nuclear DNA fragmentation were inhibited by subretinal application of brain-derived neurotrophic factor. To our knowledge, this is the first description of AIF relocalization occurring in a clinically relevant, in vivo model of apoptosis.

Animals↗
PubMed2001

Pulmonary root translocation for biventricular repair of double-outlet left ventricle.

Double-outlet left ventricle is conventionally repaired with an extracardiac conduit when pulmonary stenosis is present. We report the use of pulmonary root translocation to the right ventricle to construct the posterior wall with autologous tissue and a porcine pericardial monocusp ventricular outflow patch anteriorly for 2 patients with double-outlet left ventricle. This technique allows minimization of pulmonary insufficiency, avoids coronary artery ligation with infundibulotomy, and has a major theoretical advantage for growth potential.

Cardiac Catheterization↗
PubMed2001

Repair of total anomalous pulmonary venous connection without cardiopulmonary bypass.

Two infants with asplenia syndrome and pulmonary venous obstruction underwent repair of total anomalous pulmonary venous connection without cardiopulmonary bypass in 1988. Using a side-biting clamp, an anastomosis between the left upper pulmonary vein and left superior vena cava-atrial junction was satisfactorily created without undue instability. Furthermore, both cases had the advantage of efficient growth in the anastomotic site postoperatively.

Anastomosis, Surgical↗
PubMed2001

Reoperation for interrupted aortic arch with the use of retrograde cerebral perfusion.

We treated 2 patients with recurrent coarctation after repair of interrupted aortic arch. Because they had been operated on with the use of vascular prostheses, severe scarring was considered prohibitive for safe dissection. We successfully carried out anatomic repair with the use of retrograde cerebral perfusion through a left thoracotomy in both cases.

Adolescent↗
PubMed2001

Pulmonary agenesis with interrupted aortic arch.

This report describes a unique case of an infant with right pulmonary agenesis associated with interrupted aortic arch, ventricular septal defect, and aortic valvular stenosis. Blalock-Park arterial anastomosis and pulmonary arterial banding were performed without incidence. These techniques were useful for this complicated heart defect with pulmonary agenesis. The postoperative course of the patient was uneventful.

Abnormalities, Multiple↗
PubMed2001

Anatomically corrective repair of complete atrioventricular septal defects and major cardiac anomalies.

BACKGROUND: Although satisfactory results of corrective surgery for atrioventricular septal defects (AVSDs) with complex lesions such as double-outlet right ventricle (DORV) or atrial isomerism have been reported in recent years, the optimal surgical options for isomerism hearts is still a controversial issue. METHODS: We performed anatomically corrective repair on 13 children with balanced forms of complete AVSDs and associated major cardiac anomalies. Eight of the 13 patients had atrial isomerism (right in 1, left in 7), 5 of whom had DORV. Four others had DORV with trisomy 21, and 1 had tetralogy of Fallot. Atrial septation for isomerism with the placement of an additional prosthesis was performed on 4 patients. RESULTS: Two hospital deaths and one late death occurred only in the isomerism group. Three reoperations were required solely in the left isomerism group: one replacement of the valved external conduit concomitantly with reconstruction of the left ventricular outflow obstruction, one mitral valve replacement for severe regurgitation of left atrioventricular valve, and one relief of progressing left ventricular outflow obstruction. CONCLUSIONS: The results of anatomically corrective surgery for AVSDs with major associated cardiac anomalies in the nonisomerism group were excellent. The optimal surgical options for isomerism heart, however, remain a controversial issue.

Double Outlet Right Ventricle↗
PubMed2001

Repair of atrial septal defect through a right posterolateral thoracotomy: a cosmetic approach for female patients.

BACKGROUND: Because the operation for atrial septal defect is considered a low-risk procedure, the cosmetic result has become an important issue. Principally for cosmetic reasons, anterolateral thoracotomy is frequently used for closure of atrial septal defect in young female patients. However, in anterolateral thoracotomy, the skin incision frequently crosses the future breast line, which may cause breast and pectoral muscle maldevelopment. METHODS: We review the long-term results of a consecutive series of 126 patients in whom the atrial septal defect was closed through a right posterolateral thoracotomy. The mean age at operation was 7.1 years (range, 1 to 15 years), and the mean body weight was 23.9 kg (range, 6.9 to 56 kg). Defects repaired included 121 ostium secundum (central type), 3 sinus venosus, and 2 ostium secundum without inferior margin. RESULTS: The average cardiopulmonary bypass time was 65 minutes (range, 37 to 130 minutes), with an average fibrillation time of 41 minutes (range, 23 to 70 minutes). There was no operative or late mortality. A majority of patients were pleased with their cosmetic results. There were no other late complications. CONCLUSIONS: Atrial septal defect can be safely repaired through a right posterolateral thoracotomy approach. This approach offers the benefit of a total absence of scarring and cosmetic disfigurement of the anterior chest wall.

Adolescent↗
PubMed2001

Quantitative high-resolution microscopy on a suspended chain of gold atoms.

High-resolution electron microscope images of a suspended gold chain were analyzed quantitatively. The images of the suspended gold chain were recorded on videotapes, during in situ observation in an ultra-high-vacuum electron microscope. The chain consisted of four gold atoms free from any substrate. Image simulation verified that the gold chain has a center-top geometry. The simulation also showed that the chain has no glue atoms spinning around the axis of the chain. A spinning gold atom was shown to give 50% of the stationary atom in gray scale. By comparing the noise level of the observed image and the gray scale of single atoms such as C, Si, S, Cu, and Au, we verified that the Si and S atoms have almost twice as large contrast as the noise (peak-to-peak), and C atoms have almost the same contrast as the noise level. The analysis showed it critical to detect a single Si and S atoms.

Journal Article↗
PubMed2001

Sequence analysis of zebrafish chondromodulin-1 and expression profile in the notochord and chondrogenic regions during cartilage morphogenesis.

Chondromodulin-I (ChM-I) is suggested in higher vertebrate systems to function as a key regulatory protein for cartilage development. To further understand the process of chondrogenesis and the function of ChM-I, we have cloned the zebrafish cDNA for chondromodulin-1 (chm1) and have mapped the chm1 gene locus. The expression profile of chm1 was determined during zebrafish embryonic development and compared to that of type II collagen (col2a1). Maternal chm1 transcripts were detected before midblastula transition and zygotic expression of chm1 was first observed in the notochord at the 10-somite stage. At later developmental stages, chm1 expression was detected in areas surrounding the otic vesicles, in the developing craniofacial cartilage elements, and in the chondrogenic region of the pectoral fins.

Amino Acid Sequence↗
PubMed2001

Risk factors influencing early and late mortality after total cavopulmonary connection.

OBJECTIVE: Among the later modifications of the Fontan type procedure, a significant alteration was introduced by de Leval and associates when they described the total cavopulmonary connection (TCPC). Although current results of TCPC have encouraged us to extend this procedure to high risk patients, risk factors influencing surgical outcome after TCPC have not been evaluated. We review our experiences with TCPC to identify which risk factors may have had a considerable impact on the outcome of patients undergoing TCPC and to clarify selection criteria of high-risk Fontan candidates for TCPC. PATIENTS AND METHODS: We retrospectively reviewed the medical and surgical records of all 76 patients who underwent TCPC between July 1988 and August 2000. A cross-sectional review of these patients was undertaken. RESULTS: There were eight early deaths and four late deaths. In a Fisher's exact test, the following variables were associated with an increased early mortality after TCPC: systemic ventricular morphology (right ventricle), ejection fraction of the systemic ventricle less than 60%, and prolonged cardiopulmonary bypass time (240 min or longer). The log-rank test demonstrated that heterotaxy syndrome, moderate to severe atrioventricular valve regurgitation, prolonged cardiopulmonary bypass time (240 min or longer), and prolonged aortic cross clamp time (70 min or longer) were associated with late mortality after TCPC. Six deaths occurred in eight (75%) patients who had six or more risk factors, whereas six deaths (9%) occurred in those who had five or fewer. CONCLUSIONS: Patients with complex cardiac anomalies who have six or more risk factors should be excluded from TCPC candidates.

Adolescent↗
PubMed2001

Two-generation reproductive toxicity study of tributyltin chloride in male rats.

A 2-generation reproductive toxicity study of tributyltin chloride (TBTCl) was conducted in male rats using dietary concentrations of 5, 25, and 125 ppm TBTCl to evaluate its effect on sexual development and the reproductive system. F1 males were killed on postnatal day 119 and F2 males were killed on postnatal day 91. TBTCl affected the male reproductive system of rats. The weights of the testis and epididymis were decreased and homogenization-resistant spermatid and sperm count were reduced mainly in the 125 ppm TBTCl group. Histopathologic changes were also observed in the testis of this group and included vacuolization of the seminiferous epithelium, spermatid retention, and delayed spermiation. However, the changes were minimal in nature. The weight of the ventral prostate was decreased to 84% of the control value in the 125 ppm group in the F1 generation and decreased to 84 and 69% of the control value in the 25 ppm and 125 ppm TBTCl groups, respectively, in the F2 generation. The serum 17beta-estradiol concentration was also decreased to 55% of the control value in the 125 ppm group in the F1 generation and decreased to 78 and 57% of the control value in the 25 ppm and 125 ppm TBTCl groups, respectively, in the F2 generation. However, the serum concentrations of luteinizing hormone (LH) and testosterone were not decreased in these groups. These changes corresponded with those caused by aromatase inhibition and therefore TBTCl might be a weak aromatase inhibitor in male rats.

Animals↗