962 resultados para Chromosome number variation
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Background and Objectives: A number of familial temporal lobe epilepsies (TLE) have been recently recognized. Mutations in LGI1 (leucine-rich, glioma-inactivated 1 gene) have been found in a few families with the syndrome of autosomal dominant partial epilepsy with auditory features (ADPEAF). The authors aimed to determine the spectrum of TLE phenotypes with LGI1 mutations, to study the frequency of mutations in ADPEAF, and to examine the role of LGI1 paralogs in ADPEAF without LGI1 mutations. Methods: The authors performed a clinical and molecular analysis on 75 pedigrees comprising 54 with a variety of familial epilepsies associated with TLE and 21 sporadic TLE cases. All were studied for mutations in LGI1. ADPEAF families negative for LGI1 mutations were screened for mutations in LGI2, LGI3, and LGI4. Results: Four families had ADPEAF, 22 had mesial TLE, 11 had TLE with febrile seizures, two had TLE with developmental abnormalities, and 15 had various other TLE syndromes. LGI1 mutations were found in two of four ADPEAF families, but in none of the other 50 families nor in the 21 individuals with sporadic TLE. The mutations were novel missense mutations in exons 1 (c. 124T --> G; C42G) and 8 (c. 1418C --> T; S473L). No mutations in LGI2, LGI3, or LGI4 were found in the other two ADPEAF families. Conclusion: In TLE, mutations in LGI1 are specific for ADPEAF but do not occur in all families. ADPEAF is genetically heterogeneous, but mutations in LGI2, LGI3, or LGI4 did not account for families without LGI1 mutations.
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Fragile sites appear visually as nonstaining gaps on chromosomes that are inducible by specific cell culture conditions. Expansion of CGG/ CCG repeats has been shown to be the molecular basis of all five folate-sensitive fragile sites characterized molecularly so far, i.e., FRAXA, FRAXE, FRAXF, FRA11B, and FRA16A. In the present study we have refined the localization of the FRA10A folate-sensitive fragile site by fluorescence in situ hybridization. Sequence analysis of a BAC clone spanning FRA10A identified a single, imperfect, but polymorphic CGG repeat that is part of a CpG island in the 5'UTR of a novel gene named FRA10ACl. The number of CGG repeats varied in the population from 8 to 13. Expansions exceeding 200 repeat units were methylated in all FRA10A fragile site carriers tested. The FRA10ACl gene consists of 19 exons and is transcribed in the centromeric direction from the FRA10A repeat. The major transcript of similar to 1450 nt is ubiquitously expressed and codes for a highly conserved protein, FRA10ACl, of unknown function. Several splice variants leading to alternative 3' ends were identified (particularly in testis). These give rise to FRA10ACl proteins with altered COOH-termini. Immunofluorescence analysis of full-length, recombinant EGFP-tagged FRA10ACl protein showed that it was present exclusively in the nucleoplasm. We show that the expression of FRA10A, in parallel to the other cloned folate-sensitive fragile sites, is caused by an expansion and subsequent methylation of an unstable CGG trinucleotide repeat. Taking advantage of three cSNPs within the FRA10ACl gene we demonstrate that one allele of the gene is not transcribed in a FRA10A carrier. Our data also suggest that in the heterozygous state FRA10A is likely a benign folate-sensitive fragile site. (C) 2004 Elsevier Inc. All rights reserved.
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Among marine invertebrates, the overall biomass invested in egg production varies widely within populations, which can result from the interaction of endogenous and exogenous factors. Species that have constant reproduction throughout the year can be good models to study the influence of environmental factors on reproductive processes. We conducted a seasonal comparison of egg production in the intertidal snapping shrimp Alpheus nuttingi, which shows a continuous reproductive pattern, to examine the hypothesis that differences in egg production are driven by environmental conditions and population features. This population showed an uncommon strategy, characterized by females that produce eggs of varying sizes within their clutches, with reduced egg volume when the number of eggs is higher (Spring-Summer). In these seasons, higher temperatures and greater food availability may allow the production of more eggs compared to the Autumn-Winter seasons. Compared to other alpheid shrimps, this population produces small eggs, but in larger numbers. Despite the higher fecundity, the reproductive output is relatively low, this production being supported by the large size of females from the southern Atlantic region. Our findings showed that the egg production of A. nuttingi was greatly influenced by environmental factors. Therefore, this shrimp, and probably other decapods that possess continuous reproduction, adopt different reproductive strategies during the year. (C) Koninklijke Brill NV, Leiden, 2010.
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In some insects, the finding of oviposition substrate triggers the uptake into oocytes of yolk proteins that are stored in the fat body during post-embryonic development. The main host of the bean weevil Zabrotes subfasciatus (Coleoptera; Chrysomelidae; Bruchinae; Amblycerini), in which larval resources are the sole source for future egg maturation, is Phaseolus vulgaris. Despite not feeding as adults, females of this species are able to lay eggs after encountering host seeds but it is not known how females react to changes in the availability of bean seeds. In the present study, the behaviour of Z. subfasciatus facing two very different environments for oviposition is investigated, as well as how this influences offspring fitness. The results obtained show that females of Z. subfasciatus react to variations in the availability of seeds belonging to the same host species by adjusting egg size and number. Females on low bean seed density lay larger and fewer eggs than those on high bean seed density, demonstrating a trade-off between these reproductive traits. Moreover, females can adjust egg size to changing levels of host availability during the first 4 days of their oviposition period. Although no difference in offspring weight is found, those from small eggs (low competition environment) result in larger adults. No response to selection on these traits after rearing beetles on the same host for 40 generations is observed. This unresponsiveness may indicate that beetle populations behave according to their reaction norm that already allows rapid adaptation to a varying amount of host-seed availability and better exploitation of the environments of this widespread stored-seed pest.
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The family Alpheidae, composed by shrimps of relatively small size, popularly known as snapping shrimps, is the one of the most diverse decapod groups. These shrimps are found worldwide and Occur in tropical and subtropical waters, from the intertidal zone to great depths. We investigated reproductive aspects of Alpheus armillatus, in order to gather information on egg production, aiming to enhance knowledge of its reproductive strategies in a population in an intertidal area of the South Atlantic. Ovigerous females were collected under rocks, in May and July 2006 (dry season) and in November 2006 and March 2007 (rainy season). Egg production and reproductive output were analyzed and compared seasonally and during the period of embryonic development. Females measured on average 11.28 mm CL with a mean of 763 eggs and 0.11 mm(3) egg volume. The egg volume of this population was smaller than previous estimates for other species of snapping shrimps, but the mean egg number was higher. The volume of eggs doubled during the incubation period, but despite this increase, no significant loss of eggs was observed. Alpheus armillatus invests oil average about 12% of body weight in reproduction. The proportional investment in egg production IS Significantly higher in the rainy season when compared with the dry season (17.9% vs 4.8%), correlated with higher temperatures and increased food availability at this time. Our results corroborated the hypothesis of a pattern of egg production influenced by environmental conditions and intraspecific variability among the family Alpheidae, as a function of the biogeographic region.
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Background: Familial partial epilepsy with variable foci (FPEVF) is an autosomal dominant syndrome characterized by partial seizures originating from different brain regions in different family members in the absence of detectable structural abnormalities. A gene for FPEVF was mapped to chromosome 22q12 in two distantly related French-Canadian families. Methods: We describe the clinical features and performed a linkage analysis in a Spanish kindred and in a third French-Canadian family distantly related to the original pedigrees. Results: Onset of seizures was typically in middle childhood, and attacks were usually easy to control. Seizure semiology varied among family members but was constant for each individual. In some, a pattern of nocturnal frontal lobe seizures led to consideration of the diagnosis of autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). The Spanish family was mapped to chromosome 22q (multipoint lod score, 3.4), and the new French-Canadian family had a multipoint lod score of 2.97 and shared the haplotype of the original French-Canadian families. Conclusions: Identification of the various forms of familial partial epilepsy is challenging, particularly in small families, in which insufficient individuals exist to identify a specific pattern. We provide clinical guidelines for this task, which will eventually be supplanted by specific molecular diagnosis. We confirmed linkage of FPEVF to chromosome 22q 12 and redefined the region to a 5.2-Mb segment of DNA.
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Poly(pyrrole) (PPY) coating was prepared on a stainless-steel (SS) wire for solid-phase microextraction (SPME) by electrochemical deposition (cyclic voltammetric). The PPY was evaluated by analyzing new-generation antidepressants (mirtazapine, citalopram, paroxetine, duloxetine, fluoxetine, and sertraline) in plasma sample by SPME and liquid chromatography with UV detection (LC-UV). The effect of electrolyte Solution (lithium perchlorate or tetrabutylammonium perchlorate) and the number of cycles (50, 100 or 200) applied during the polymerization process on the SPME performance was evaluated. Important factors in the optimization of SPME efficiency such as extraction time, temperature, pH, influence of plasma proteins on sorption mechanisms, and desorption conditions are discussed. The SPME-PPY/LC method showed to be linear in concentrations ranging from the limit of quantification (LOQ) to 1200 ng mL(-1). The LOQ values range from 16 to 25 ng mL-1. The inter-day precision of the SPME-PPY/LC method presented coefficient of variation (CV) lower than 15%. Based on analytical validation results, the SPME-PPY/LC methodology showed to be adequate for antidepressant analysis, from therapeutic to toxic levels. In order to evaluate the proposed method for clinical use, the SPME-PPY/LC method was applied to the analysis of plasma samples from elderly depressed patients. (c) 2009 Elsevier B.V. All rights reserved,
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Objective: The purpose of this study was to evaluate the inflammatory cell subset proportions in the upper gingival connective tissue, including mature dendritic cells (DC) in elderly and younger patients with generalized chronic periodontitis in order to further understand the effect of aging on gingival inflammatory phenomenon. Methods: Gingival tissue specimens presenting chronic periodontitis from 8 elderly patients aged >75 (test group, group T) and from 8 younger patients aged 50-60 (considered as controls, group C) were analysed by immunohistochemistry using monoclonal antibodies against CD45RB, CD4, CD8, CD19, CD68, DC-SIGN, DC-LAMP molecules. The number of each immunolabelled cells subset was counted using image analysis. Results: The difference in the number of CD45RB + leucocytes in the upper gingival connective tissue between groups was not significant permitting to use it as reference. As compared. to group C, the lymphocyte subsets/CD45RB + leucocytes ratios tended to decrease in group T but the decrease was significant only for CD4 + T lymphocytes/ CD45RB + cells ratio (p < 0.03). On the opposite, the ratios of antigen-presenting cells DC-SIGN + cells/CD45RB + cells and DC-LAMP + cells/CD45RB + cells were significantly increased;(p < 0.03 and <0.0001, respectively) in group T. Moreover, in group T the DC-LAMP + cells/DC-SIGN + cells ratio was significantly increased (p < 0.05) showing an increased number of matured dendritic cells. Conclusion: During chronic periodontitis in elderly patients, our results show a decrease in the ratio of gingival CD4 + lymphocyte subset associated with an increase in the ratios of antigen-presenting cells subsets and more particularly maturated DC-LAMP + dendritic cells. (C) 2008 Elsevier Ltd. All rights reserved.
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A sensitive and reproducible stir bar-sorptive extraction and high-performance liquid chromatography-UV detection (SBSE/HPLC-UV) method for therapeutic drug monitoring of carbamazepine, carbamazepine-10,11-epoxide, phenytoin and phenobarbital in plasma samples is described and compared with a liquid:liquid extraction (LLE/HPLC-UV) method. Important factors in the optimization of SBSE efficiency such as pH, extraction time and desorption conditions (solvents, mode magnetic stir, mode ultrasonic stir, time and number of steps) assured recoveries ranging from 72 to 86%, except for phenytoin (62%). Separation was obtained using a reverse phase C-18 column with UV detection (210 nm). The mobile phase consisted of water: acetonitrile (78:22, v/v). The SBSE/HPLC-UV method was linear over a working range of 0.08-40.0 mu g mL(-1) for carbamazepine, carbamazepine-10,11-epoxide and phenobarbital and 0.125-40.0 mu g mL(-1) for phenytoin, The intra-assay and inter-assay precision and accuracy were studied at three concentrations (1.0, 4.0 and 20.0 mu g mL(-1)). The intra-assay coefficients of variation (CVs) for all compounds were less than 8.8% and all inter-CVs were less than 10%. Limits of quantification were 0.08 mu g mL(-1) for carbamazepine, carbamazepine-10,11-epoxide and phenobarbital and 0.125 mu g mL(-1) for phenytoin. No interference of the drugs normally associated with antiepileptic drugs was observed. Based on figures of merit results, the SBSE/HPLC-UV proved adequate for antiepileptic drugs analyses from therapeutic levels. This method was successfully applied to the analysis of real samples and was as effective as the LLE/HPLC-UV method. (c) 2008 Elsevier B.V. All rights reserved.
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We generalize a proposal for detecting single-phonon transitions in a single nanoelectromechanical system (NEMS) to include the intrinsic anharmonicity of each mechanical oscillator. In this scheme two NEMS oscillators are coupled via a term quadratic in the amplitude of oscillation for each oscillator. One NEMS oscillator is driven and strongly damped and becomes a transducer for phonon number in the other measured oscillator. We derive the conditions for this measurement scheme to be quantum limited and find a condition on the size of the anharmonicity. We also derive the relation between the phase diffusion back-action noise due to number measurement and the localization time for the measured system to enter a phonon-number eigenstate. We relate both these time scales to the strength of the measured signal, which is an induced current proportional to the position of the read-out oscillator.
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A sensitive, selective, and reproducible in-tube solid-phase microextraction and liquid chromatographic (in-tube SPME/LC-UV) method for simultaneous determination of mirrazapine, citalopram, paroxetine, duloxetine, fluoxetine, and sertraline in human plasma was developed, validated and further applied to the analysis of plasma samples from elderly patients undergoing therapy with antidepressants. Important factors in the optimization of in-tube SPME efficiency are discussed, including the sample draw/eject volume, draw/eject cycle number, draw/eject flow-rate, sample pH, and influence of plasma proteins. The quantification limits of the in-tube SPME/LC method varied between 20 and 50 ng/mL, with a coefficient of variation lower than 10%. The response of the in-tube SPME/LC method for most of the drugs was linear over a dynamic range from 50 to 500 ng/mL, with correlation coefficients higher than 0.9985. The in-tube SPME/LC can be successfully used to analyze plasma samples from ageing patients undergoing therapy with nontricyclic antidepressants. (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
A sensitive and reproducible method by microextraction packed sorbent and liquid chromatography with UV detection (MEPS/LC-UV) is described for the determination of new generation antidepressants (sertraline, mirtazapine, fluoxetine, citalopram and paroxetine) in human plasma samples. The MEPS variables, such as sample volume, pH, number of extraction cycles (draw-eject), and desorption conditions (solvent and solvent volume of elution) influenced the MEPS/LC efficiency significantly. Important factors in the optimization of MEPS efficiency, as well as washing steps and carryover effect are discussed. The analyses were carried out using small sample volumes (400 mu L.), and in a short time period (3 min for the entire sample preparation step). The MEPS/LC-UV method was shown to be linear at concentrations ranging from the limit of quantification (LOQ) to 1000 ng mL(-1). The LOQ values ranged from 10 to 25 ng mL(-1). The inter-day precision of the method presented coefficient of the variation ranging from 1.3% to 8.7%. On the basis of analytical validation, it is shown that the MEPS/LC-UV methodology is adequate for antidepressant analysis, from therapeutic to toxic levels. In order to evaluate the proposed method for clinical use, the MEPS/LC-UV method was applied to analysis of plasma samples from elderly depressed patients. (C) 2010 Elsevier B.V. All rights reserved.
Resumo:
A sensitive and reproducible stir bar-sorptive extraction and high performance liquid chromatography-UV detection (SBSE/HPLC-UV) method for therapeutic drug monitoring of rifampicin in plasma samples is described and compared with a liquid:liquid extraction (LLE/HPLC-UV) method. This miniaturized method can result in faster analysis, higher sample throughput, lower solvent consumption and less workload per sample while maintaining or even improving sensitivity. Important factors in the optimization of SBSE efficiency such as pH, temperature, extraction time and desorption conditions (solvents, mode magnetic stir, mode ultrasonic stir, time and number of steps) were optimized recoveries ranging from 75 to 80%. Separation was obtained using a reverse phase C(8) column with UV detection (254 nm). The mobile phase consisted of methanol:0.25 N sodium acetate buffer, pH 5.0 (58:42, v/v). The SBSE/HPLC-UV method was linear over a working range of 0.125-50.0 mu g mL(-1). The intra-assay and inter-assay precision and accuracy were studied at three concentrations (1.25, 6.25 and 25.0 mu g mL(-1)). The intra-assay coefficients of variation (CVs) for all compounds were less than 10% and all inter-CVs were less than 10%. Limits of quantification were 0.125 mu g mL(-1). Stability studies showed rifampicin was stable in plasma for 12 h after thawing; the samples were also stable for 24 h after preparation. Based on the figures of merit results, the SBSE/HPLC-UV proved to be adequate to the rifampicin analyses from therapeutic to toxic levels. This method was successfully applied to the analysis of real samples and was as effective as the LLE/HPLC-UV method. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
A sensitive, selective, and reproducible in-tube polypyrrole-coated capillary (PPY) solid-phase microextraction and liquid chromatographic method for fluoxetine and norfluoxetine enantiomers analysis in plasma samples has been developed, validated, and further applied to the analysis of plasma samples from elderly patients undergoing therapy with antidepressants. Important factors in the optimization of in-tube SPME efficiency are discussed, including the sample draw/eject volume, draw/eject cycle number, draw/eject flow-rate, sample pH, and influence of plasma proteins. Separation of the analytes was achieved with a Chiralcel OD-R column and a mobile phase consisting of potassium hexafluorophosphate 7.5 mM and sodium phosphate 0.25 M solution, pH 3.0, and acetonitrile (75:25, v/v) in the isocratic mode, at a flow rate of 1.0 mL/min. Detection was carried out by fluorescence absorbance at Ex/Em 230/290 nm. The multifunctional porous surface structure of the PPY-coated film provided high precision and accuracy for enantiomers. Compared with other commercial capillaries, PPY-coated capillary showed better extraction efficiency for all the analytes. The quantification limits of the proposed method were 10 ng/mL for R- and S-fluoxetine, and 15 ng/mL for R- and S-norfluoxetine, with a coefficient of variation lower than 13%. The response of the method for enantiomers is linear over a dynamic range, from the limit of quantification to 700ng/mL, with correlation coefficients higher than 0.9940. The in-tube SPME/LC method can therefore be successfully used to analyze plasma samples from ageing patients undergoing therapy with fluoxetine. (C) 2009 Elsevier B.V. All rights reserved.