Search Results - (Author, Cooperation:M. Hatori)

2011-10-01

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

ARNTL Transcription Factors/*metabolism ; Acetylation ; Animals ; CLOCK Proteins/*metabolism ; *Circadian Clocks ; DNA-Binding Proteins ; Drosophila/genetics/physiology ; Drosophila Proteins/genetics/metabolism ; Gene Expression Regulation ; HEK293 Cells ; Histone Deacetylase Inhibitors ; Histone Deacetylases/metabolism ; Histone Demethylases ; Histone-Lysine N-Methyltransferase/genetics/metabolism ; Histones/metabolism ; Humans ; Jumonji Domain-Containing Histone Demethylases ; Male ; Mice ; Mice, Knockout ; Period Circadian Proteins/genetics ; Promoter Regions, Genetic ; Retinoblastoma-Binding Protein 2/*metabolism ; Transcription, Genetic ; Transfection

2012-03-31

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Biological Clocks/drug effects/genetics ; Circadian Rhythm/genetics/*physiology ; Cryptochromes/deficiency/genetics/metabolism ; *Energy Metabolism/genetics ; Feedback, Physiological ; Gene Expression Regulation ; Gene Regulatory Networks/genetics ; Homeostasis/genetics ; *Lipid Metabolism/genetics ; Liver/metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Molecular Sequence Data ; Motor Activity/genetics/physiology ; Nuclear Receptor Subfamily 1, Group D, Member 1/deficiency/genetics/*metabolism ; Period Circadian Proteins/deficiency/genetics/metabolism ; Receptors, Cytoplasmic and Nuclear/deficiency/genetics/*metabolism ; Repressor Proteins/deficiency/genetics/*metabolism ; Transcriptome/genetics

0378-4363

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

1399-3054

Blackwell Publishing Journal Backfiles 1879-2005

Biology

An in vitro bioassay system for floral bud formation has been established using Nicotiana tabacum L. cv. MC, explants excised from floral stalks cultured on modified Murashige-Skoog medium containing excess auxin and antiauxin. Three auxins. indolyl-3-acetic acid (IAA), 4-chloroindolyl-3-acetic acid and 5,6-dichloroindolyl-3-acetic acid, were tested for floral bud-forming activity; IAA was most efficient. Three antiauxins. 5,7-dichlorindolyl-3-isobutyric acid (5,7-Cl2-HBA), p-chlorophenoxyiso butyric acid and 2,3,5-triiodobenzoic acid, were tested for the ability to reverse the inhibition of floral bud formation caused by excess IAA. Only 5,7-Cl2-HBA was very effective. Leaf exudates from short day- and long day-treated tobacco plants were added to the bioassay system which contained 1 µM 6-benzylaminopurine, 5 µM IAA and 5 µM 5, 7-Cl2-HBA, Interestingly, only the leaf exudate from short day-treated plants stimulated floral bud formation. Moreover, the buds produced grew into large. well-developed ones with shapes similar to those of the natural floral buds of intact tobacco plants.

Electronic Resource

0040-4039

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1434-3916

Springer Online Journal Archives 1860-2000

Medicine

Abstract Multiple epiphyseal dysplasia (MED) is a relatively uncommon inherited disorder of epiphyseal maturation. Affected individuals may have a degree of short-limbed dwarfism, short stubby digits, and stiff or painful joints. We report two families of MED and emphasize the variations of joint involvement. Ten out of 34 members in family A and 13 out of 39 members in family B were suspected of having MED by questionnaire. Radiological examination was done for 3 out of the 10 members in family A and 6 out of the 13 members in family B. In both families, the epiphyseal disturbances in the skeleton were bilaterally symmetric and involved several joints. Apparent dwarfism, short stubby digits and spinal involvement were not observed. The degree and the pattern of affected joints were different in the two families and even among members of the same family. In family A, the knee joint was commonly affected, followed by the ankle joint. The deformity of the joints was mild and caused only slight disability. No apparent hip lesion was present. In family B, the hip joint was predominantly affected, followed by the knee and ankle joints, and the deformity was severer than that in family A. These observations suggest that MED is a group of heterogeneous disorders.

Electronic Resource

1432-0827

Hoechst dye ; Chondrocytes ; DNA analysis ; Mineralization ; Alkaline phosphatase

Springer Online Journal Archives 1860-2000

Biology

Medicine

Physics

Abstract Most investigators are cognizant of the problems inherent in counting cells embedded in a complex and abundant extracellular matrix. To overcome these obstacles, we developed a new method of isolating nucleic acids from chondrocytes which facilitates measurement of cell number by DNA analysis. Chondrocytes were isolated from chick embryo sterna and grown continuously without subculturing for 2–3 weeks in monolayer. The cells were treated with triton X-100 and the nucleic acid content of the extract was determined by measuring DNA fluorescence in the presence of Hoechst dye 33258. To minimize background fluorescence due to the triton, we precipitated the DNA with alcohol and then solubilized the nucleic acids in EDTA. This simple procedure removed the detergent and substantially increased the sensitivity of the method. Thus, we could measure with high precision and high recovery, the DNA content of cultures of 10,000–50,000 cells. In a single well containing 0.5–1.0 million cells, sufficient material remained for subsequent measurements of alkaline phosphatase activity and protein and calcium content. As the mineral present in the triton-treated samples was soluble in EDTA, we experienced no problems in measuring the calcium content of the culture. In addition, as triton X-100 is a nonionic detergent, we were able to measure cell and matrix proteins; moreover, the presence of the triton maintained the catalytic state of alkaline phosphatase. We conclude that this procedure provides a simple and rapid approach to measuring major indicators of chondrocyte maturation and function.

Electronic Resource

1432-0827

Thalassemia ; Mineralization ; Alkaline phosphatase ; Deferoximine ; Chondrocytes ; Free radicals ; Ascorbate

Springer Online Journal Archives 1860-2000

Biology

Medicine

Physics

Abstract The homozygous form of β-thalassemia, the most common single gene disorder, is treated by red cell transfusion therapy. Following transfusion, the chelator, deferoximine, is administered to patients to remove excess iron. However, when this drug is given to young children, metaphyseal dysplasia and abnormalities of linear growth are frequently observed. To explore the notion that deferoximine mine interferes with endochondral growth by chelating zinc, we examined the effect of the drug on chondrocytes maintained in long-term culture. We found that deferoximine caused a dose-dependent inhibition of a wide range of functions including cell proliferation, protein synthesis (and possibly under-hydroxylation of type X collagen), and mineral deposition. Directly relevant to the mineralization process was the observation that the drug dramatically lowered the activity of alkaline phosphatase, a zinc-requiring enzyme. To test the hypothesis that enzyme inhibition was due to chelation of zinc by deferoximine, the cell culture medium was supplemented with excess zinc. However, this treatment did not overcome the deferoximine-dependent change in enzyme activity. We next examined the possibility that deferoximine, in the presence of ascorbate, could form a free radical system that would serve to inactivate the enzyme. Using alkaline phosphatase extracted from chick cartilage, we noted that the activity of the phosphatase was markedly reduced in the presence of deferoximine and ascorbate. These effects were consistant with the notion that deferoximine and ascorbate can act as a prooxidant couple. This conclusion was confirmed when we measured the oxidative activities of the system using nitroblue tetrazolium and cytochrome c. Indeed, we noted that deferoximine markedly activates the autocatalytic oxidation of ascorbate. We next investigated the possibility that the change in alkaline phosphatase activity was due to the formation of reactive oxygen radicals. Though oxygen radical scavengers and disproportionating agents did not change the activity of the enzyme, α-tocopherol provided complete protection. In conclusion, the deferoximine-ascorbate couple inactivates chondrocyte alkaline phosphatase probably by generation of free radicals. As free radicals can damage cartilage as well as other tissues, clinical regimens that are directed at elevating ascorbate levels in thalassemia need to be carefully reviewed.

Electronic Resource

1432-2277

Key words Non-episode biopsy ; Arteriolopathy ; Cyclosporine ; Tacrolimus ; Renal transplantation

Springer Online Journal Archives 1860-2000

Medicine

Abstract Histopathological findings in renal allograft with stable function remain unclear. We therefore performed non-episode biopsy in the long-surviving renal allograft to investigate the histopathological changes. Our data show that, although arteriolopathy is characteristic of drug-induced nephropathy, it is unrelated to dosage and concentration of cyclosporine or tacrolimus in non-episode biopsy. We evaluated therefore the clinicopathological findings of arteriolopathy in this study. Non-episode biopsy was defined as follows: as serum creatinine level lower than, 2.0 mg/dl and a urinary protein level lower than 500 mg/day. A total of 65 biopsy specimens were enrolled in this study as non-episode biopsy. Twenty-nine specimens revealed arteriolopathy. There were no statistically significant differences between arteriolopathy and dosage or concentration of cyclosporine or tacrolimus. Arteriolopathy in non-episode biopsy was related to time of biopsy, kidney age, hypertension, and hyperlipidemia, suggesting that it is important for graft survival to strictly control blood pressure and blood lipid level.

Electronic Resource

1432-5195

Springer Online Journal Archives 1860-2000

Medicine

Résumé. Nous rapportons ici le cas d’un nourrisson âgé de neuf mois présentant une hyperostose corticale infantile associée à une fibrose kystique. Un épaississement périosté a été observé symétriquement dans les clavicules, les côtes, les fémurs, les humérus, les cubitus et les radius. Les hyperostoses périostées de l’humérus sont survenues en association avec une augmentation du taux des phosphatases alcalines un mois avant l’apparition d’hyper-irritabilité et de gonflement des tissus mous aux alentours des articulations coxo-fémorales. Un retour graduel à la normale a été observé dans les huit mois.

Summary. We describe a boy aged nine months with infantile cortical hyperostosis in association with cystic fibrosis. Symmetrical periosteal thickening was present in the clavicles, ribs, femora, humeri, ulnae and radii. Periosteal hyperostosis of the humerus developed in association with an increase in the levels of serum alkaline phosphatase a month before the appearance of hyperirritability and soft tissue swelling about the hip joints. The condition gradually resolved during the following eight months.

Electronic Resource