58 research outputs found
Cuf2 Is a Novel Meiosis-Specific Regulatory Factor of Meiosis Maturation
Meiosis is the specialized form of the cell cycle by which diploid cells produce the haploid gametes required for sexual reproduction. Initiation and progression through meiosis requires that the expression of the meiotic genes is precisely controlled so as to provide the correct gene products at the correct times. During meiosis, four temporal gene clusters are either induced or repressed by a cascade of transcription factors
Isolation, characterization, and in vitro differentiation of ovine amniotic stem cells
Copper-Dependent Trafficking of the Ctr4-Ctr5 Copper Transporting Complex
In Schizosaccharomyces pombe, copper uptake is carried out by a heteromeric complex formed by the Ctr4 and Ctr5 proteins. Copper-induced differential subcellular localization may play a critical role with respect to fine tuning the number of Ctr4 and Ctr5 molecules at the cell surface.We have developed a bimolecular fluorescence complementation (BiFC) assay to analyze protein-protein interactions in vivo in S. pombe. The assay is based on the observation that N- and C-terminal subfragments of the Venus fluorescent protein can reconstitute a functional fluorophore only when they are brought into tight contact. Wild-type copies of the ctr4(+) and ctr5(+) genes were inserted downstream of and in-frame with the nonfluorescent C-terminal (VC) and N-terminal (VN) coding fragments of Venus, respectively. Co-expression of Ctr4-VC and Ctr5-VN fusion proteins allowed their detection at the plasma membrane of copper-limited cells. Similarly, cells co-expressing Ctr4-VN and Ctr4-VC in the presence of Ctr5-Myc(12) displayed a fluorescence signal at the plasma membrane. In contrast, Ctr5-VN and Ctr5-VC co-expressed in the presence of Ctr4-Flag(2) failed to be visualized at the plasma membrane, suggesting a requirement for a combination of two Ctr4 molecules with one Ctr5 molecule. We found that plasma membrane-located Ctr4-VC-Ctr5-VN fluorescent complexes were internalized when the cells were exposed to high levels of copper. The copper-induced internalization of Ctr4-VC-Ctr5-VN complexes was not dependent on de novo protein synthesis. When cells were transferred back from high to low copper levels, there was reappearance of the BiFC fluorescent signal at the plasma membrane.These findings reveal a copper-dependent internalization and recycling of the heteromeric Ctr4-Ctr5 complex as a function of copper availability
Effect of supplemental tocopherol in diet of laying hen on volatile compound content of egg yolk
A flow-chart for a critical appraisal of new technology. The experience of near-infrared spectroscopy.
Usefulness and limit of NIRS are discusse
The risk of mastication weakness after percutaneous balloon compression for the treatment of trigeminal neuralgia
Abstract not availabl
An ovine preimmune foetal model to study the effect of cellular therapies for myocardic diseases
The ovine foetus is an ideal model for preclinical medical studies of cell therapies. It allows us to follow the behaviour of repairing cells inserted into a favourable physiological microenvironment in an animal species more closely related to humans than the rat or rabbit. In addition, the preimmune foetus is able to support cell engraftment by eliminating the problems of tissue rejection. Labelled fibroblasts were transplanted into the myocardium of preimmune foetuses, injecting through a disposable bowed mouth pipette into the left ventricular apex. Two weeks later, foetuses were isolated by laparotomy and each heart was collected and morphologically analyzed. No cases of abortion or postoperative complications in mothers or foetuses occurred. Macroscopically, the isolated hearts did not display any abnormality apart from a small petechia at the injection site. Tissue sections did not show any sign of acute tissue inflammation and viable labelled cells were easily identified among myocardiocytes. This model system guarantees a reduced damage in the engrafted tissue, a high survival and easy retrieval of the injected cells. The direct injection of cells into the preimmune ovine foetus myocardium can be satisfactorily performed to control tissue delivery and to reduce the risk of cell loss and dispersion
Interactions with hemoglobin: A source of error in measurements of transketolase activity in hemolysates
Measurements of the activity of transketolase in human erythrocyte lysates by an assay coupled to NADH oxidation indicate that interactions of assay substrates with hemoglobin can give rise to overestimations of transketolase activity. Three potential sources of error are identified. Thus, in lysates containing methemoglobin, NADH oxidation can be due firstly to methemoglobin reductase activity or secondly to the monooxygenase activity of methemoglobin, for which the substrate can be ribose 5-phosphate, a substrate also of transketolase. Thirdly, the addition of high concentrations of the transketolase cofactor, TDP, to an insufficiently buffered reaction mixture can cause the aggregation and precipitation of hemoglobin: a phenomenon that may be misconstrued as an enhanced increase in absorbance at 340 nm and hence as additional transketolase activity. Although the present study concentrates on these potential artefacts in assays of transketolase activity, the findings may well be relevant to the measurement of other enzyme activities in hemolysates by procedures based ultimately on the rate of consumption or production of NAD(P)H
Microvascular decompression in patients with trigeminal neuralgia and multiple sclerosis: results and analysis of possible prognostic factors
We evaluated the results of microvascular decompression (MVD) in patients with trigeminal neuralgia (TN) and multiple sclerosis (MS) and we studied the role of several clinical and surgical factors as possible prognosticators of good outcome. To do this we performed, to our knowledge, the first literature review with a pooled analysis of data. A PubMed search of literature was conducted using the following terms: \u201cmicrovascular decompression\u201d, \u201ctrigeminal neuralgia\u201d and \u201cmultiple sclerosis\u201d. We screened 64 articles. Of them, 7 studies were eligible for this review. As outcome indicators we used the acute pain relief (APR) and the recurrence of pain. An APR was obtained in 71.42% and a recurrence of pain was reported in 26.00% of cases, respectively. At univariate analysis, younger age at surgery (p = 0.0419) and performing MVD as the first treatment (p = 0.0384) were associated to a higher probability of APR. The evidence of an MRI brainstem lesion related to the TN (p = 0.0482) was associated to a lower probability to obtain an APR after MVD. None of the evaluated factors affect the probability of recurrence of pain. At multivariate analysis the evidence of a brainstem MRI lesion related to the TN emerged as a negative prognosticator of APR (p = 0.0169). Our literature pooled analysis showed that MVD is effective in treating patients with MS-related TN. The evidence on MRI of a demyelinating plaque related to the TN is associated with a worse response to MVD. These data could suggest that MVD would be indicated mainly in patients without brainstem MRI lesions
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