PubMed Health⌕ Search

Biomedical subjects

M Onodera

Publications and source records attributed to M Onodera.

At least 37 records · Page 2Linked to original sources
PubMed2000

Regulation of angiogenesis by controlling VEGF receptor.

The endothelial cells cultured in collagen gel caused upregulation of KDR expression, which resulted in an increase in tube formation. Endothelial cells exposed to high glucose (33 mmol/l) for 30 days increased the tube formation induced by VEGF, but not by serum and bFGF. Immunohistochemical study showed that KDR expression was upregulated by the high-glucose treatment. The endothelial cells treated with 0.5-5 micrograms/ml eicosapentaenoic acid (EPA, 20:5, n-3) for 48 h displayed a dose-dependent suppression of tube formation, VEGF-induced proliferation, and activation of p42/p44 MAP kinase but not bFGF-induced ones. Pretreatment with arachidonic acid (20:4, n-6) and docosahexaenoic acid (22:6, n-3) did not show such effects. The expression of KDR was downregulated by the EPA pretreatment. The bone is the richest tissue in microvessel networks except for the liver. Osteoblasts produced VEGF and some factor(s) that could induce KDR upregulation in endothelial cells and could enhance tube formation. These results lead to the speculation that the regulation of KDR expression as well as VEGF production is deeply involved in angiogenesis under various conditions.

Animals↗
PubMed2000

Adenosine deaminase deficiency as the first target disorder in gene therapy.

In the past decade, the advent of gene therapy has been acclaimed as a revolutionary medical intervention, embraced with great enthusiasm. However, recent disappointing results of the considerable clinical trials have also clearly demonstrated that such an initial expectation was an overestimation of gene therapy. There are only a few successful cases despite the 3000 patients who have been treated with various forms of gene therapy. Gene therapy for severe combined immunodeficiency (SCID) caused by adenosine deaminase (ADA) deficiency is one of the few such cases where results have been promising. In particular, peripheral T-lymphocytes-directed gene therapy provides further immunological improvements for patients with ADA-SCID receiving the PEG-ADA treatment whereas gene therapy targeting haematopoietic stem cell has so far proved insufficient for clinical benefits. This report will review crucial problems elucidated in the past five clinical trials for ADA-SCID and gives an outline of the next generation of stem cell gene therapy in Japan.

Adenosine Deaminase↗
PubMed1999

Endothelin in the central control of cardiovascular and respiratory functions.

1. Exogenously administered endothelin (ET) modulates the activity of cardiovascular and respiratory neurons in the central nervous system (CNS) and, thus, affects arterial blood pressure (ABP) and ventilation. However, a physiological role(s) for endogenous ET in the CNS has not been elucidated. To address this question, we examined ABP and ventilation in mutant mice deficient in ET-1, ETA and ETB receptors and endothelin-converting enzyme-1, which were made by gene targeting. 2. Respiratory frequency and volume was measured in mice by whole body plethysmography when animals breathed normal room air and hypoxic and hypercapnic gas mixtures. A few days after respiratory measurements, a catheter was implanted into the femoral artery under halothane anaesthesia. On the following day, the ABP of awake mice was measured through the indwelling catheter and heart rate was calculated from the ABP signal. After 2 h ABP measurement, arterial blood was collected through the catheter and pH and the partial pressures of O2 and CO2 were measured by a blood gas analyser. 3. Compared with corresponding controls, the mean (+/- SEM) ABP in ET-1+/- and ETB-deficient mice was significantly higher (118 +/- 2 vs 106 +/- 3 mmHg for ET-1+/- (n = 22) and ET-1+/+ (n = 17) mice, respectively; 127 +/- 3 vs 109 +/- 4 mmHg for ETB-/s (n = 9) and ETB+/s (n = 9) mice, respectively; P < 0.05 for both). In ET-1+/- mice, PCO2 tended to be higher and PO2 was significantly lower than corresponding values in ET-1+/+ mice. Under resting conditions, there was no significant difference in respiratory parameters between mutants and their corresponding controls. However, reflex increases of ventilation to hypoxia and hypercapnia were significantly attenuated in ET-1+/-, ET-1-/- and ETA-/- mice. 4. In another series of experiments in ET-1+/- mice, we found that sympathetic nerve activity (SNA) was augmented and reflex excitation of phrenic nerve activity (PNA) in response to hypoxia and hypercapnia was blunted. Attenuation of the reflex PNA response to hypercapnia was also observed in the medulla-spinal cord preparation from ET-1-/- mice. 5. Elevation of ABP in ETB-deficient mice was most likely due to a peripheral mechanism, because SNA and respiratory reflexes were not different from those in control animals. 6. We conclude that endogenous ET-1 plays an important role in the central neural control of circulation and respiration and that ETA receptors mediate this mechanism.

Animals↗
PubMed1999

Ultrastructural features of goat oviductal secretory cells at follicular and luteal phases of the oestrous cycle.

The aim of the present study was to investigate the ultrastructure of secretory cells in the various regions of the goat oviduct during the follicular and luteal phases of the oestrous cycle. During the follicular phase in the fimbriae, the secretory cells contained small secretory granules with electron-dense matrices. In the luteal phase, the secretory granules disappeared and cytoplasmic protrusions, extending beyond the luminal border of the ciliated cells and often containing the nucleus, were predominant. During the follicular phase in ampullary secretory cells, numerous secretory granules with moderately electron-dense matrices were present in the supranuclear cytoplasm and exocytosis of secretory granules was observed. The number of secretory granules was dramatically reduced in the ampullary secretory cells at the luteal phase. Conspicuous cytoplasmic protrusions of secretory cells were observed similar to those of the fimbrial epithelium. Isthmic cells were almost free of secretory granules and lysosome-like bodies were found both at the follicular and luteal phases. In conclusion, our ultrastructural observations of goat oviduct revealed marked cyclic changes in the ultrastructural features of secretory cells and the ultrastructural features and the numbers of secretory granules were distinctive for each particular segment.

Animals↗
PubMed1999

Synthesis and properties of oligodeoxynucleotides containing a C-2 polyamine-bearing deoxyguanosine residue as artificial ribonuclease.

Oligodeoxynucleotides containing a 2-fluoro-2'-deoxyinosine residue substituting normal 2'-deoxyguanosine residue were synthesized. Upon treating with ethanol solution of polyamine, the fluorine atom in the oligomers were readily substituted with the polyamine. The thermal stabilities of the duplexes consisted of the polyamine-bearing oligomers and their cDNAs as well as their RNA cleaving activity were investigated.

Base Sequence↗
PubMed1999

Elevation of blood pressure by genetic and pharmacological disruption of the ETB receptor in mice.

Exogenously administered endothelin (ET) elicits both pressor and depressor responses through the ETA and/or the ETB receptor on vascular smooth muscle cells and ETB on endothelial cells. To test whether ETB has pressor or depressor effects under basal physiological conditions, we determined arterial blood pressure (BP) in ETB-deficient mice obtained by crossing inbred mice heterozygous for targeted disruption of the ETB gene with mice homozygous for the piebald (s) mutation of the ETB gene (ETBs/s). F1 ETB-/s and ETB+/s progeny share an identical genetic background but have ETB levels that are approximately (1)/(8) and (5)/(8), respectively, of wild-type mice (ETB+/+). BP in ETB-/s mice was significantly higher, by approximately 20 mmHg, than that in ETB+/s or ETB+/+ mice. Immunoreactive ET-1 concentration in plasma as well as respiratory parameters was not different between ETB-/s and ETB+/s mice. A selective ETB antagonist, BQ-788, increased BP in ETB+/s and ETB+/+ but not in ETB-/s mice. Pretreatment with indomethacin, but not with NG-monomethyl-L-arginine, can attenuate the observed pressor response to BQ-788. The selective ETA antagonist BQ-123 did not ameliorate the increased BP in ETB-/s mice. Moreover, BP in mice heterozygous for targeted disruption of the ETA gene was not different from that in wild-type controls. These results suggest that endogenous ET elicits a depressor effect through ETB under basal conditions, in part through tonic production of prostaglandins, and not through secondary mechanisms involving respiratory control or clearance of circulating ET.

Animals↗
PubMed1999

Gene therapy for severe combined immunodeficiency caused by adenosine deaminase deficiency: improved retroviral vectors for clinical trials.

Severe combined immunodeficiency (SCID) caused by adenosine deaminase deficiency (ADA-) is the first genetic disorder to be treated with gene therapy. Since 1990 when the first trial started for 2 patients with ADA- SCID, five clinical trials enrolling 11 patients have been conducted with different clinical approaches and the results obtained from these trials have recently been reported. According to these reports, T cell-directed gene transfer was useful in the treatment of ADA- SCID whereas the retroviral-mediated gene transfer to hematopoietic stem cells was insufficient for achievement of clinical benefits. This chapter reviews several crucial problems inherent in the current retroviral technology based on the clinical data observed in these pioneering ADA gene therapy trials and presents our new retroviral vector system for the next stem cell gene therapy.

Adenosine Deaminase↗
PubMed1999

Retroviral-mediated transfer and expression of the common gamma chain into human hematopoietic progenitors.

The common gamma chain (gammac) of cytokine receptors is mutated in X-linked severe combined immunodeficiency, a lethal disorder characterized by the absence of both humoral and cellular immune defenses. Allogeneic bone marrow transplantation from HLA-identical siblings usually results in complete reconstitution of the immune system and is the current treatment of choice. Genetic correction and reinfusion of autologous hematopoietic stem cells represents an alternative therapeutic approach for those patients who lack suitable marrow donors. In this study, we show that retroviral-mediated transfer of the gammac gene results in efficient expression in CD34+ cells and high transduction rate of colony-forming progenitors.

Antigens, CD34↗
PubMed1998

Characterization of diverse viral vector preparations, using a simple and rapid whole-virion dot-blot method.

A number of different viruses have been adapted as gene transfer vectors, including retroviruses, adenoviruses, adenoassociated viruses (AAVs), herpes simplex virus, SV40 viruses, and alphaviruses (both Semliki Forest and Sindbis viruses). One of the major rate-limiting and time-consuming steps in the characterization of these vectors is the process of determining the viral vector titers. In addition, there is no "universal" method that can be used to rapidly estimate the titer and the utility of viral vector preparations. We demonstrate here that supernatant from diverse classes of viral vectors, with either RNA or DNA genomes, can be rapidly evaluated by a simple virus dot-blot hybridization without prior extraction of nucleic acids. This system can provide a reliable screen for physical titer of viral vector supernatants in 1 day.

Adenoviridae↗
PubMed1998

Renal sympathetic nerve activity in mice: comparison between mice and rats and between normal and endothelin-1 deficient mice.

Recently generated knockout mice with disrupted genes encoding endothelin (ET)-1 showed an elevation of arterial blood pressure (AP) and supplied an evidence for intrinsic ET-1 as one of the physiological regulators of systemic AP. Little is yet known, however, why deficiency of ET-1, which was originally found as a potent vasoconstrictor, led to higher AP in these mice. To address this apparent paradox, we first developed a method to measure renal sympathetic nerve activity (RSNA) in mice using rats as reference and successively compared it between normal and ET-1 deficient mice. RSNA was successfully recorded in urethane-anesthetized and artificially ventilated mice by a slight modification of the method used for rats. At basal condition, mean AP (MAP) and RSNA in ET-1 deficient mice (105+/-2 mmHg and 9.71+/-1.49 muVs, n=20) were significantly higher than those in wild-type mice (96+/-2 mmHg and 5. 07+/-0.70 muVs, n=25). Basal heart rate (HR) and baroreflex-control of HR was not significantly different between the two. On the other hand, resting RSNA, RSNA range, and maximum RSNA were significantly greater in ET-1 deficient mice, and thus MAP-RSNA relationship was upwards reset. Hypoxia-induced increase in RSNA was not different between ET-1 deficient (73.4+/-9.4%) and wild-type mice (91.2+/-12.0%), while hypercapnia-induced one was significantly attenuated in ET-1 deficient mice (18.8+/-3.6 vs. 39.1+/-5.2% at 10% CO2). These results indicate that endogenous ET-1 participates in the central chemoreception of CO2 and reflex control of the RSNA. Baroreceptor resetting and normally preserved hypoxia-induced chemoreflex may explain a part of the elevation of AP in ET-1 deficient mice.

Animals↗
PubMed1998

Successful peripheral T-lymphocyte-directed gene transfer for a patient with severe combined immune deficiency caused by adenosine deaminase deficiency.

Ten patients with adenosine deaminase deficiency (ADA-) have been enrolled in gene therapy clinical trials since the first patient was treated in September 1990. We describe a Japanese ADA- severe combined immune deficiency (SCID) patient who has received periodic infusions of genetically modified autologous T lymphocytes transduced with the human ADA cDNA containing retroviral vector LASN. The percentage of peripheral blood lymphocytes carrying the transduced ADA gene has remained stable at 10% to 20% during the 12 months since the fourth infusion. ADA enzyme activity in the patient's circulating T cells, which was only marginally detected before gene transfer, increased to levels comparable to those of a heterozygous carrier individual and was associated with increased T-lymphocyte counts and improvement of the patient's immune function. The results obtained in this trial are in agreement with previously published observations and support the usefulness of T lymphocyte-directed gene transfer in the treatment of ADA-SCID.

Adenosine Deaminase↗
PubMed1998

Development of improved adenosine deaminase retroviral vectors.

A series of adenosine deaminase (ADA) retroviral vectors were designed and constructed with the goal of improved performance over the PA317/LASN vector currently used in clinical trials. First, the bacterial selectable-marker neomycin phosphotransferase (neo) gene was removed to create a "simplified" vector. Second, the Moloney murine leukemia virus long terminal repeat (LTR) promoter used for ADA expression was replaced with either the myeloproliferative sarcoma virus (MPSV) or SL3-3 LTR. Supernatant from each ADA vector was used to transduce ADA-deficient (ADA-) B- and T-cell lines as well as primary peripheral blood mononuclear cells (PBMC) from an ADA- severe combined immunodeficiency patient. Total ADA enzyme activity and ADA activity per integrant in the transduced cells demonstrated that the MPSV LTR splicing vector design provided the highest level of ADA expression per cell. This ADA(MPSV) vector was then tested in packaging cell lines containing either the gibbon ape leukemia virus envelope (PG13 cells), the murine amphotropic envelope (FLYA13 cells), or the feline endogenous virus RD114 envelope (FLYRD18 cells). The results indicate that FLYRD18/ADA(MPSV), a simplified ADA retroviral vector with the MPSV LTR, provides a 17-fold-higher level of ADA expression in human lymphohematopoietic cells than the PA317/LASN vector currently in use.

Adenosine Deaminase↗
PubMed1998

Bifid ribs observed in the third and the fourth ribs.

Three cases of bifid ribs were found in two cadavers during routine dissections at the Iwate Medical University School of Dentistry. All of the cases were found in the third or the fourth rib. The distal parts of the osseous rib bifurcated with an angle of 60 degrees and both of the branches had their own costal cartilage. The costal cartilage fused again to form the trunk which was connected to the sternum. The space between the two branches was filled with presumably normal intercostal muscles. Blood supply was maintained by a small branch from the interthoracic artery to the upper branches. However, the intercostal nerves did not branch toward the upper branch but only ran along the lower margins of the lower branches of the bifid ribs.

Aged↗
PubMed1997

A simple and reliable method for screening retroviral producer clones without selectable markers.

Simplified retroviral vectors that lack dominant selectable markers are being used with increasing frequency. These simplified vectors may offer a number of advantages over selectable marker-containing constructs, including potentially higher titers and less immunogenicity. However, the use of these vectors has been limited by the cumbersome experimental approaches in establishing and characterizing useful producer cell clones. To address this issue, a simple and reliable assay was developed to identify retroviral producer cell lines with or without dominant selectable markers. Producer cells were first generated by standard transfection/transduction and clones isolated by limiting dilution. Supernatant from each clone was then screened by RNA dot blot to identify the best producer clone candidates. The semiquantitative nature of the RNA dot blot assay was validated using a retroviral vector containing neomycin phosphotransferase (neo). Titers obtained by conventional G418-resistant colony forming units/ml (G418(R) cfu/ml) assays strongly correlated with the values by RNA dot blot procedure. RNA dot blot results also correlated well with titers estimated by Southern analysis of HeLa cells transduced with supernatant from each clone. The RNA dot blot technique is a rapid (2 days) and reliable method to screen retroviral producer cells, thereby facilitating the generation and characterization of simplified retroviral producer cell clones.

Animals↗
PubMed1997

Determination of ventilatory volume in mice by whole body plethysmography.

We examined the reliability of whole-body plethysmography (WBP) for determining the ventilatory volume in mice. The degree of agreement of tidal volume (VT) determined consecutively by WBP with that by direct plethysmography (DP) or pneumotachography (PT) was analyzed using urethane-anesthetized young male 129/Sv mice. Between WBP and DP, the mean difference of VT was 0.000 ml with a 95% confidence interval of -0.003 to 0.002, whereas that between WBP and PT was 0.000 ml (-0.004 to 0.003). The limits of agreement, or mean +/- 2SD of the difference, were -0.008 and 0.008 ml in WBP vs. DP, and -0.011 and 0.010 ml in WBP vs. PT. These values were 5.1-6.6% of the average VT (0.157 ml in WBP and DP, and 0.165 ml in WBP and PT). Thus, VT can be determined by WBP without any bias and with a systemic error of less than 7% of that measured by the other direct methods examined. Through applying WBP to conscious 129/Sv and 129/SvJ-ICR hybrid mice, we further studied the effects of differences in mouse strain, age and sex on respiratory rate (f) and minute volume (V = VT.f), and their reflex changes in responses to systemic hypoxia and hypercapnia. V was significantly greater in young (10-16 weeks old) male 129/Sv than in young male 129/SvJ-ICR hybrids (139 +/- 11 and 73 +/- 8 ml/min/100 g, respectively), while the pattern of reflex responses was similar. In aged (32-44 weeks old) male 129/Sv, the basal level of V and its reflex increases were all diminished as compared to those in their young counter parts. However, we were unable to find significant differences between aged male and female 129/Sv mice. In conclusion, WBP is a useful and reliable method to determine ventilatory parameters in conscious and anesthetized mice. Furthermore, there are considerable strain- and age-related differences in baseline ventilation and reflex responses to hypoxia and hypercapnia.

Age Factors↗
PubMed1996

Impaired ventilatory responses to hypoxia and hypercapnia in mutant mice deficient in endothelin-1.

We studied respiratory functions in mutant mice deficient in endothelin-1 (ET-1) generated by gene targeting. In conscious adult mice heterozygous for ET-1 gene mutation (ET+/- heterozygous mice), arterial PO2 was significantly lower, PCO2 tended to be higher, and pH tended to be lower than in wild-type littermates. When these conscious mice breathed room air, respiratory minute volume and rate, determined by body plethysmography, were not significantly different between the two groups. However, when ET+/- heterozygous mice were subjected to systemic hypoxia (1:1 air-N2) or hypercapnia (5% CO2-95% O2), increases in respiratory minute volume were significantly attenuated. In conscious newborn ET-/- homozygous mice delivered by cesarean section and tracheotomized, ventilatory responses to systemic hypoxia and hypercapnia, regularly observed in newborn wild-type mice, were almost totally absent. In urethan-anesthetized adult ET+/- heterozygous mice, increases in phrenic nerve discharges in response to hypoxia and hypercapnia were significantly attenuated. Our results demonstrate that ventilatory responses to hypoxia and hypercapnia are impaired in ET-1-deficient mice and suggest that endogenous ET-1 participates in the physiological control of ventilation.

Animals↗
PubMed1995

Overexpression of retinoic acid receptor alpha suppresses myeloid cell differentiation at the promyelocyte stage.

Retinoic acid receptor (RAR) alpha is required to heterodimerize with retinoid X receptor (RXRs) in order to regulate myeloid differentiation. If so, it is expected that overexpression of normal RAR alpha may perturb the RAR alpha/RXR heterodimer formation and also the differentiation of myeloid cells. We have described here the morphology and the RA response of human RAR alpha cDNA transduced murine bone marrow cells using a retroviral vector. Most of RAR alpha transduced cells displayed promyelocyte like morphology and their proportion of c-kit expressing population was increased remarkably compared with the control (Neor gene transduced cells). Furthermore, this morphology was observed even after these cells were brought into the semisolid culture containing IL-3 alone. Interestingly, immature RAR alpha transduced cells differentiated into mature granulocytes under the condition of the high concentration of RA(10(-6) M). We did not observe any effect of RAR alpha on monocytes. These results indicate that overexpression of normal RAR alpha is sufficient for inducing maturation arrest of myeloid cell lineage that is similar to the phenotype found in the acute promyelocytic leukemia bearing PML-RAR alpha translocation.

3T3 Cells↗