[Role of microtubules in automorphic curvatures of rice coleoptiles under simulated microgravity conditions].
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Cotyledon↗
Biomedical subjects
M Saiki
Publications and source records attributed to M Saiki.
Adenovirus-mediated gene transfer of basic fibroblast growth factor promotes the survival of primary-cultured rat neuronal cells.
We constructed two replication-deficient recombinant adenovirus vectors coding human basic fibroblast growth factor (bFGF), one with and one without the interleukin-2 (IL-2) secretory signal sequence and examined their neurotrophic effects on primary neuronal cells in vitro. The primary neuronal cells were successfully infected at a high efficiency with the adenovirus vectors. bFGF protein was detected in the culture medium of the neurons infected with both these vectors. The cells infected with the bFGF-expressing adenovirus containing the IL-2 signal sequence showed 2- to 10-fold higher levels of secretion levels than cells infected with the native bFGF-expressing adenovirus alone. Both bFGF-expressing vectors augmented the survival of primary neuronal cells in an in vitro culture, compared with a mock infection or control virus infection. Notably, the cells infected with the bFGF-expressing adenovirus containing the IL-2 signal sequence were markedly enhanced cell survival in the early phase of the culture, compared with the control cells and even those infected with the bFGF-expressing adenovirus without the IL-2 signal sequence. However, in the late phase of neuronal culture, neither viral vector could support the cell survival. In contrast the co-infection of the bFGF-expressing vector with a Bcl-xL-expressing vector was extremely effective on neuronal survival.
Adenoviridae↗
Cytotoxicity due to corrosion of ear piercing studs.
It is well known that allergic and/or inflammatory reactions can be elicited from the use of gold-coated studs, particularly the type used for piercing ears, since they are left in contact with body fluids until the puncture heals. Inasmuch as gold is known as a non-toxic element, other elements of the substrate material may be responsible for some allergies. Therefore, characteristics of the coating, such as defects that expose the substrate to the human skin or body fluids, play an important role in the development of skin sensitization. In this study, the cytotoxicity of commercial studs used for ear piercing and laboratory-made studs was determined in a culture of mammalian cells. The corrosion performance of the studs was investigated by means of weight loss measurements and electrochemical impedance spectroscopy. The elements that leached out into the medium were also analysed by instrumental neutron activation analysis. Further, the surfaces of the studs were examined by scanning electron microscopy and analysed by energy dispersive spectroscopy to identify defects and reaction products on the surface, both before and after their exposure to the culture medium. The stud which showed lower corrosion performance resulted in higher cytotoxicity. Ti showed no cytotoxicity and high corrosion resistance, proving to be a potential material for the manufacture of ear piercing studs.
Alloys↗
Adenoviral gene transfer of basic fibroblast growth factor promotes angiogenesis in rat brain.
Cerebral ischemic disease often causes morbidity and mortality, while the induction of new blood vessels is expected to provide a therapeutic effect in this occlusive cerebrovascular disease. In this study, we utilized two replication-deficient adenoviral vectors containing cDNA from basic fibroblast growth factor (bFGF), a well-known angiogenic factor, and examined whether biological angiogenic activity of adenovirally gene-transferred bFGF could be observed in the rat brain. One vector contained native cDNA from bFGF without the secretory signal sequence and the other contained the same cDNA fused with an interleukin-2 secretory signal sequence. After ventricular administration of these viral vectors, gene-transferred cells demonstrated a high immunoreactivity against the anti-bFGF antibody and a remarkably high concentration of bFGF was detected in the cerebrospinal fluid. A semiquantitative analysis of angiogenic activity revealed that bFGF gene transfer induced angiogenesis in normal rat brains, with a more pronounced angiogenic effect seen with the vector of a secreted form than with the vector without a secretory signal sequence. These results suggest that bFGF gene transfer using these adenoviral vectors might be useful for the treatment of ischemic cerebrovascular disease.
Adenoviridae↗
Selenium and glutathione peroxidase mRNA in rat glioma.
The purpose of current study was to determine the step at which dietary selenium (Se) regulates the transcriptional expression of the gene for Se-glutathione peroxidase (Se-GPx) in rat brain and transplanted glioma tissue. Wistar rats were fed a Se-free diet or the same diet supplemented with 0.5, 2.0, and 4.0 mg Se/kg as sodium selenite for at least 3 wk. Then, the rats were transplanted with C6 rat glioma cells into the right frontal lobe parenchyma. All rats were observed for 30 d, then tumor and contralateral brain tissue were excised and divided into three portions for purification of selenium content, for the assay of Se concentration, Se-GPx activity, and for Se-GPx mRNA. Se concentration and Se-GPx activity are increased with Se supplementation both in tumor tissue and contralateral brain tissue, and Se concentration in tumor is higher than that in contralateral brain tissue at each dietary Se content. Se-GPx mRNA of brain and tumor were probed with fragments from a rat Se-GPx cDNA in Northern blot analysis. There was significant differences of Se-GPx mRNA transcription in brain tumor tissue among each dietary group of the Se content, and the steady-state level of Se-GPx mRNA was markedly reduced by Se deficiency. These results suggest that dietary Se exerts its augmenting effect on Se-GPx gene transcription.
Animals↗
[Plasma cell leukemia presenting with circulating villous lymphocytes and an indolent clinical course].
A 73-year-old man was admitted to our hospital in July 1996 because of lymphoctyosis and lumbago. Physical examination revealed hepatomegaly and anemia. Hematologic examination showed a hemoglobin concentration of 9.6 g/dl and a leukocyte count of 32,700/microliter with 74% abnormal mononuclear cells. In Wright-Giemsa stained blood films, these cells had short villi arising from 1 or 2 poles. Immunophenotyping of peripheral mononuclear cells showed moderate to strong expression of CD10, CD24, CD38, and sIg lambda, but not of CD19, CD20, or CD25. Southern blot analysis of the peripheral mononuclear cells demonstrated rearranged monoclonal bands in the C lambda. Urine immunoelectrophoresis detected a monoclonal band identifiable as lambda-type Bence Jones protein. In addition, bone X-ray studies disclosed multiple osteolytic lesions. A diagnosis of plasma cell leukemia was made, and the patient was placed on chemotherapy consisting of cyclophosphamide and prednisolone. No notable improvement in laboratory findings was seen but the patient experienced an indolent clinical course. He died of pneumonia in January 1998. The morphological and clinical findings were unusual for a case of plasma cell leukemia. This case study suggested that signs of lymphocytosis require immunophenotypic and electron microscopic studies for the differential diagnosis of plasma cell leukemia.
Aged↗
[Changes in the mechanical and chemical properties of rice coleoptile cell walls under microgravity conditions].
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Cell Wall↗
[Mechanism of automorphic curvature in rice coleoptiles under simulated microgravity conditions].
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Cell Wall↗
Instrumental neutron activation analysis of rib bone samples and of bone reference materials.
The instrumental neutron activation analysis method was used for the determination of trace elements in rib bone samples taken from autopsies of accident victims. The elements Br, Ca, Cl, Cr, Fe, Mg, Mn, Na, P, Sr, Rb, and Zn were determined in cortical tissues by using short and long irradiations with thermal neutron flux of the IEA-R1m nuclear reactor. The reference materials NIST SRM 1400 Bone Ash and NIST SRM 1486 Bone Meal were also analyzed in order to evaluate the precision and the accuracy of the results. It was verified that lyophilization is the most convenient process for drying bone samples because it does not cause any element losses. Comparisons were made between the results obtained for rib samples and the literature values as well as between the results obtained for different ribs from a single individual and for bones from different individuals.
Neutron Activation Analysis↗
Evaluation of trace elements in lung samples from coal miners using neutron activation analysis.
In this study, instrumental neutron activation analysis was applied to the determination of Sc, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Hf, Th, and U in lung samples from miners working in coal mines located in the state of Santa Catarina, Brazil. These results were compared to those from a control group constituted of healthy individuals. The results showed that the elements determined exhibit considerable intersubject variability within a single group of individuals and the mean values of concentrations in miners' lungs were higher than those of normal individuals. Lung samples presented U concentrations varying from 11 to 890 micrograms/kg. Therefore, for some samples, the contribution of the uranium fission products in the analysis of La, Ce, Nd, and Sm was considered by determining the interference correction factors. The accuracy of the results was evaluated by analyzing certified reference materials.
Coal Mining↗
Morphogenesis of rice and Arabidopsis seedlings in space.
Seedlings of rice (Oryza saliva L.) and Arabidopsis (A. thaliana L.) were cultivated for 68.5 hr in the RICE experiment on board during Space Shuttle STS 95 mission, and changes in their growth and morphology were analyzed. Microgravity in space stimulated elongation growth of both rice coleoptiles and Arabidopsis hypocotyls by making their cell walls extensible. In space, rice coleoptiles showed an inclination toward the caryopsis in the basal region and also a spontaneous curvature in the same direction in the elongating region. These inclinations and curvatures were more prominent in the Koshihikari cultivar compared to a dwarf cultivar, Tan-ginbozu. Rice roots elongated in various directions including into the air on orbit, but two thirds of the roots formed a constant angle with the axis of the caryopsis. In space, Arabidopsis hypocotyls also elongated in a variety of directions and about 10% of the hypocotyls grew into the agar medium. No clear curvatures were observed in the elongating region of Arabidopsis hypocotyls. Such a morphology of both types of seedlings was fundamentally similar to that observed on a 3 D clinostat. Thus, it was confirmed by the RICE experiment that rice and Arabidopsis seedlings perform an automorphogenesis under not only simulated but also true microgravity conditions.
Arabidopsis↗
Comparison of the biological activities in venoms from three subspecies of the South American rattlesnake (Crotalus durissus terrificus, C. durissus cascavella and C. durissus collilineatus)
The subspecies of the South American rattlesnake, Crotalus durissus are classified according to their external morphological features and geographical distribution. We have determined some biological activities of C. durissus cascavella, C. durissus collilineatus and C. durissus terrificus venoms. C. durissus terrificus had a significantly higher clotting activity on bovine plasma and fibrinogen, human fibrinogen and rabbit plasma. C. durissus cascavella presented a statistically higher phospholipase A2 (PLA2) activity in regard to C. durissus collilineatus. Their myotoxic and proteolytic activity, median lethal doses, or median platelet aggregating doses (on rabbit and human platelets) could not differentiate the three subspecies examined. However, the electrophoretic profile and the dose-response curve for edematogenic activity for C.d. cascavella venom were different from the others. With regard to the inorganic element content of the venoms, higher levels of Br, Cl and Mg, and a lower level of Zn, were found in C.d. cascavella venom. Crotamine-like activity could not be detected in C.d. cascavella venom. Furthermore, equine antivenom specific for C. durissus terrificus venom cross-reacted equally with the antigens of the three venom pools by ELISA and Western blotting. These results indicate that the venoms from the three studied subspecies of C. durissus were very similar, except for minor differences in paw edema-inducing activity, electrophoretic profile, phospholipase A2 activity, crotamine-like activity and inorganic element contents of C.d. cascavella venom.
Animals↗
Adenovirus-mediated gene transfer of a truncated form of fibroblast growth factor receptor inhibits growth of glioma cells both in vitro and in vivo.
Basic fibroblast growth factor (FGF-2) and high affinity FGF receptor (FGFR) have been detected in the nucleus as well as the cytoplasm of many human gliomas, and are known to stimulate cellular proliferation and angiogenesis in the tumors. To investigate the effects of inactivation of FGFR on the growth of malignant gliomas, we constructed a replication-deficient recombinant adenovirus vector encoding a truncated form of chicken FGFR1 (AxCA delta FR). AxCA delta FR-infected cells were confirmed to express truncated FGFR protein by immunoblotting and FGF-2-dependent clonogenicity of NIH3T3 cells was suppressed by infection with this virus vector. Then human malignant glioma cell lines U-251MG and T98G, both of which have been reported to express FGF-2 and FGFR, were infected with AxCA delta FR. These infected cells showed nuclear as well as cytoplasmic expression of a truncated FGFR protein. Proliferation rate and the ability to form colonies in soft agar of the cells infected with this virus vector were significantly suppressed compared with those of uninfected and lacZ-expressing adenovirus-infected cells. Moreover, intratumoral injection of AxCA delta FR significantly suppressed the subcutaneous tumor growth of the glioma cells in nude mice. We concluded that inactivation of the cytoplasmic and nuclear FGFR using this truncated FGFR-expressing adenovirus vector can inhibit the growth of malignant gliomas both in vitro and in vivo.
3T3 Cells↗
Therapy-related megakaryoblastic leukemia with pituitary involvement following treatment for non-Hodgkin's lymphoma.
A case of a 66-year-old Japanese man developed therapy-related megakaryoblastic leukemia with pituitary involvement after chemotherapy for non-Hodgkin's lymphoma. Alkylating agents had been administered for the treatment of non-Hodgkin's lymphoma and 6 years later, megakaryoblastic leukemia with myelofibrosis and myelodysplasia developed. The blast cells expressed CD41, and immature antigens also. These findings were compatible with therapy-related megakaryoblastic leukemia. An autopsy revealed blast-cell infiltration into multiple organs including the posterior pituitary lobe. Therapy-related megakaryoblastic leukemia is very rare, and pituitary involvement may be associated with immaturity of blast cells.
Antigens, CD↗
[Automorphogenesis of rice and Arabidopsis seedlings under microgravity conditions].
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Arabidopsis↗
Adenovirally expressed basic fibroblast growth factor rescues photoreceptor cells in RCS rats.
PURPOSE: To evaluate the abilities of recombinant adenovirus carrying the basic fibroblast growth factor (bFGF) gene to (1) produce bFGF protein in vitro and (2) rescue retinal photoreceptors in Royal College of Surgeons (RCS) rats in vivo. METHODS: Cultured human retinal pigment epithelial cells were infected with one of the following two replication-deficient adenoviral vectors that drive inserted genes by beta-actin promoter with cytomegalovirus enhancer: AxCAJSbFGF, which expresses the human bFGF gene, and AxCAlacZ, carrying the cDNA of bacterial beta-galactosidase as a viral control. These viruses and recombinant bFGF protein were also injected into the subretinal space of RCS rats at the age of 21 days. The production of bFGF was evaluated by an immunohistochemical method in vitro and in vivo. The secretion of bFGF produced in vitro was quantified by an enzyme-linked immunosorbent assay. The thickness of the outer nuclear layer (ONL) as a marker of photoreceptor cell rescue was estimated at 2, 28, and 56 days after the injections. RESULTS: AxCAJSbFGF produced human bFGF protein effectively both in vitro and in vivo. The semiquantitative analysis of ONL thickness revealed a significant protective effect of AxCAJSbFGF and the recombinant bFGF protein injection up to 56 days after injection. CONCLUSIONS: These results demonstrate that a recombinant adenoviral vector can achieve the transfer of bFGF gene in vitro and have a protective effect for photoreceptor cells in vivo. Gene therapy with a bFGF-expressing recombinant adenoviral vector may provide a new strategy with which to target retinal degenerative diseases.
Adenoviridae↗
In vitro growth suppression of vascular smooth muscle cells using adenovirus-mediated gene transfer of a truncated form of fibroblast growth factor receptor.
Vascular smooth muscle cell (VSMC) proliferation associated with arterial injury causes restenosis, which remains to be resolved in cardiovascular and ischemic cerebrovascular disease, especially after balloon angioplasty. Fibroblast growth factor (FGF) is a potent mitogen and a trophic factor for a variety of cells, including VSMCs. We constructed a replication-deficient adenovirus vector, designated AxCA delta FR, coding a truncated form of fibroblast growth factor receptor-1 (FGFR-1) gene lacking the intracellular domain to interrupt receptor-mediated FGF signaling, and examined its effect on the proliferation of primary-cultured rat VSMCs. We transferred the truncated form of the FGFR-1 gene to the VSMCs and confirmed its expression and localization in infected cells by Western blotting and immunofluorescence study. The VSMCs infected with AxCA delta FR degenerated and the proliferation of these cells was suppressed markedly by the infection with this virus in vitro. Our results suggest that the receptor-mediated signal of FGFs has an important role in VSMC proliferation and gene transfer of a truncated form of FGFR using adenoviral vector may be useful for the treatment of the diseases caused by excessive proliferation of VSMCs like restenosis after percutaneous transluminal angioplasty or carotid endoarterectomy.
Adenoviridae↗
Adenovirus-mediated gene transfer of basic fibroblast growth factor induces in vitro angiogenesis.
To investigate the possibility of adenovirus-mediated gene transfer in the treatment of vascular occlusive diseases, we constructed a replication-deficient recombinant adenovirus vector coding for human basic fibroblast growth factor (bFGF) and examined its effect on the proliferation and differentiation of vascular endothelial cells in vitro. Human umbilical vein endothelial cells (HUVECs) were successfully infected with high efficiency and expressed 18 kD protein which is immunoreactive to anti-bFGF monoclonal antibody. This protein was accumulated mainly in the nuclei of the cells, but was also detected in the culture medium although the complimentary DNA (cDNA) did not contain the classical secreting signal sequence. The proliferation assay of HUVECs infected with bFGF-expressing adenovirus revealed a significant increase in cell number over control. Infection with this virus also enhanced tubular formation of HUVECs on reconstituted basement membrane. Neovascularization and the formation of collateral vessels play important roles in minimizing tissue damage in ischemic disorders. These results imply that the use of bFGF-expressing recombinant adenovirus may be a suitable in vivo gene therapy for ischemic diseases.
Adenoviridae↗