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排序方式: 共有875条查询结果,搜索用时 359 毫秒
821.
García-Vielma C de la Fuente-Cortez B Méndez-Ramírez CA González LR Moreira-Flores R Cerda-Flores RM 《Journal of the Association of Genetic Technologists》2010,36(3):102-106
Throughout the world, chromosome alterations are one of the main causes of major malformations in newborns and of multiple clinical characteristics in patients of other ages. The present study had as its principle objective to determine the distribution of chromosome alterations obtained from 1999-2009 at a private laboratory located in Monterrey, Nuevo Leon state, Mexico, and that received samples from other northeastern Mexican states. We studied 1,652 cases of peripheral blood karyotypes. Samples were obtained from patients in whom there was a suspicion of some chromosome alteration based on the clinical history. Of the karyotypes evaluated, 1,250 (76.0%) had normal karyotype, 320 (19.0%) presented chromosome alterations, among which 270 (84%) were numerical, 50 (16%) were structural, and 82 (5.0%) were polymorphisms. Chromosome alteration frequency and type found in the present study is similar to that found in studies conducted in other countries and to that reported in the literature. 相似文献
822.
Antonio Nieto Jesús Avila Manuel Martínez Valdivia 《Molecular and cellular biochemistry》1981,37(3):185-189
Summary The presence of the microtubule-associated protein (MAP2) in the brain of several species has been investigated by SDS-gel electrophoresis and by radioimmunoassay. This assay had
a sensitivity of approx. 10 ng and it was capable of measuring the protein either in purified microtubules or in crude brain
extracts. As determined with this radioimmunoassay, MAP2 accounted for about 10% of the porcine brain microtubule protein and 1% of the protein from a brain extract. Taking porcine
MAP2 as a reference, we have detected polypeptides with the same electrophoretic mobility in brain microtubules from cow, sheep,
rat and chicken. Nevertheless, the MAP2 from these species showed a variable degree of immunoreactivity. Bovine MAP2 appeared closely related to the porcine protein whereas the rat antigen showed low cross-reaction and chicken MAP2 appeared immunologically unrelated to porcine MAP2. Our results suggest a higher variability of the MAP2 sequences as compared to that reported by other authors for the brain microtubule protein, tubulin. 相似文献
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825.
Ana-Maria OpreaLenuta Profire Catalina Elena LupusoruCristina Mihaela Ghiciuc Diana CiolacuCornelia Vasile 《Carbohydrate polymers》2012,87(1):721-729
Mixed hydrogels based on natural, biodegradable and biocompatible polysaccharides, such as cellulose (C) and chondroitin sulphate (CS) in various mixing ratios were prepared by a crosslinking technique and characterized by swelling behaviour, FTIR spectroscopy, scanning electron microscopy, toxicity and biocompatibility tests.The mixed cellulose/chondroitin sulphate hydrogels have been loaded with 7-[2-nitroxiacetyl-oxy-3-(4-acetyl-amino-phenoxy)-propyl]-8-morpholino-1,3-dimethyl-xanthine, a novel nitric oxide donor compound with a lower toxicity and a higher anti-inflammatory activity than its parent molecules, paracetamol and theophylline. Swelling and release kinetics have been also studied. It has been established that an increase of CS content in hydrogels composition leads to a higher swelling ratio for all formulations and to a decreased released amount of nitric oxide donor compound. It has been found that the swelling occurs by an anomalous swelling mechanism, while the release of nitric oxide donor compound follows a diffusion controlled mechanism. 相似文献
826.
Ariana A. Huerta‐Heredia Ricardo Marín‐López Teresa Ponce‐Noyola Carlos M. Cerda‐García‐Rojas Gabriela Trejo‐Tapia Ana C. Ramos‐Valdivia 《Engineering in Life Science》2009,9(3):211-218
The effect of oxidative stress on indole alkaloids accumulation by cell suspensions and root cultures of Uncaria tomentosa in bioreactors was investigated. Hydrogen peroxide (H2O2, 200 μM) added to U. tomentosa cell suspension cultures in shaken flasks induced the production of monoterpenoid oxindole alkaloids (MOA) up to 40.0 μg/L. In a stirred tank bioreactor, MOA were enhanced by exogenous H2O2 (200 μM) from no detection up to 59.3 μg/L. Root cultures grew linearly in shaken flasks with a μ=0.045 days?1 and maximum biomass of 12.08±1.24 g DW/L (at day 30). Roots accumulated 3α‐dihydrocadambine (DHC) 2354.3±244.8 μg/g DW (at day 40) and MOA 348.2±32.1 μg/g DW (at day 18). Exogenous addition of H2O2 had a differential effect on DHC and MOA production in shaken flasks. At 200 μM H2O2, MOA were enhanced by 56% and DHC by 30%; while addition of 800 and 1000 μM H2O2, reduced by 30–40% DHC accumulation without change in MOA. Root cultures in the airlift reactor produced extracellular H2O2 with a characteristic biphasic profile after changing aeration. Maximum MOA was 9.06 mg/L at day 60 while at this time roots reached ca. 1 mg/L of DHC. Intracellular H2O2 in root cultures growing in the bioreactor was 0.87 μmol/g DW compared to 0.26 μmol/g DW of shaken flasks cultures. These results were in agreement with a higher activity of the antioxidant enzymes superoxide dismutase and peroxidase by 6‐ and 2‐times, respectively. U. tomentosa roots growing in the airlift bioreactor were exposed to an oxidative stress and their antioxidant system was active allowing them to produce oxindole alkaloids. 相似文献
827.
Background
With the biomedical literature continually expanding, searching PubMed for information about specific genes becomes increasingly difficult. Not only can thousands of results be returned, but gene name ambiguity leads to many irrelevant hits. As a result, it is difficult for life scientists and gene curators to rapidly get an overall picture about a specific gene from documents that mention its names and synonyms. 相似文献828.
Jose M. Irimia Vincent S. Tagliabracci Catalina M. Meyer Dyann M. Segvich Anna A. DePaoli-Roach Peter J. Roach 《The Journal of biological chemistry》2015,290(37):22686-22698
Glycogen, the repository of glucose in many cell types, contains small amounts of covalent phosphate, of uncertain function and poorly understood metabolism. Loss-of-function mutations in the laforin gene cause the fatal neurodegenerative disorder, Lafora disease, characterized by increased glycogen phosphorylation and the formation of abnormal deposits of glycogen-like material called Lafora bodies. It is generally accepted that the phosphate is removed by the laforin phosphatase. To study the dynamics of skeletal muscle glycogen phosphorylation in vivo under physiological conditions, mice were subjected to glycogen-depleting exercise and then monitored while they resynthesized glycogen. Depletion of glycogen by exercise was associated with a substantial reduction in total glycogen phosphate and the newly resynthesized glycogen was less branched and less phosphorylated. Branching returned to normal on a time frame of days, whereas phosphorylation remained suppressed over a longer period of time. We observed no change in markers of autophagy. Exercise of 3-month-old laforin knock-out mice caused a similar depletion of glycogen but no loss of glycogen phosphate. Furthermore, remodeling of glycogen to restore the basal branching pattern was delayed in the knock-out animals. From these results, we infer that 1) laforin is responsible for glycogen dephosphorylation during exercise and acts during the cytosolic degradation of glycogen, 2) excess glycogen phosphorylation in the absence of laforin delays the normal remodeling of the branching structure, and 3) the accumulation of glycogen phosphate is a relatively slow process involving multiple cycles of glycogen synthesis-degradation, consistent with the slow onset of the symptoms of Lafora disease. 相似文献
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