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171.
Chung JY Yi JM Xie R Brown V Lee O Ahuja N Braunschweig T Hewitt SM 《Analytical biochemistry》2012,425(2):128-134
As emerging novel DNA-based methodologies are adopted, nucleic acid-based assays depend critically on the quality and quantity of extracted DNA. Formalin-fixed, paraffin embedded (FFPE) tissue samples provide an invaluable resource for subsequent molecular studies of clinical phenotypes, but high-quality DNA extraction from archival FFPE tissue specimens remains complex and time-consuming. To address this challenge, we have developed a reliable rapid DNA extraction method for FFPE tissue specimens. It is based on deparaffinization at high temperature coupled with relieving crosslink in a pressure cooker. The DNA yield by this rapid method resulted in an average 1.8-fold increase in comparison with the commercial kit and OD 260/280 ratios between 1.87 and 1.95. The DNA obtained by the rapid method was suitable for methylation analyses in colon cancer patients. These data suggest that this new DNA extraction method coupled with methylation-specific polymerase chain reaction can be used for epigenetic studies with the advantages of rapidity and high quality and may contribute to the development of biomarkers in clinical studies. 相似文献
172.
Progesterone is an endogenous immunomodulator that is able to suppress T cell activation during pregnancy. An increased intracellular free calcium concentration ([Ca(2+)](i)), acidification, and an inhibition of Na(+)/H(+)-exchange 1 (NHE1) are associated with this progesterone rapid non-genomic response that involves plasma membrane sites. Such acidification, when induced by phytohemagglutinin, is calcium dependent in PKC down-regulated T cells. We investigated the relationship between this rapid response involving the [Ca(2+)](i) increase and various membrane progesterone receptors (mPRs). In addition, we explored whether the induction of acidification in T cells by progesterone is a direct result of the [Ca(2+)](i) increase. The results show that the intracellular calcium elevation caused by progesterone is inhibited by SKF96365, U73122, and 2-APB, but not by pertussis toxin or U73343. The elevation is enhanced by the protein tyrosine kinase inhibitor staurosporine and the protein kinase C inhibitors Ro318220 and Go6983. These findings suggest that progesterone does not stimulate the [Ca(2+)](i) increase via the Gi coupled mPR(α). Furthermore, progesterone-induced acidification was found to be dependent on Ca(2+) entry and blocked by the inorganic channel blocker, Ni(2+). However, BAPTA, an intracellular calcium chelator, was found to prevent progesterone-induced acidification but not the inhibition of NHE1. This implies that acidification by progesterone is a direct result of the [Ca(2+)](i) increase and does not directly involve NHE1. Taken together, further investigations are needed to explore whether one or more mPRs or PGRMC1 are involved in bringing about the T cell rapid response that results in the [Ca(2+)](i) increase and inhibition of NHE1. 相似文献
173.
174.
Obesity has been associated with altered cerebral functions including cognitive control. The stop signal task (SST) has been widely used to study cognitive control by producing high conflict stop trials among many low conflict go trials. Contrasting these stop trials with go trials provides a measure of saliency processing and response inhibition. By comparing functional magnetic resonance images of obese (BMI >30) and lean (BMI <22) females performing the SST, we observed differences in regional brain activations despite similar behavioral performance between groups. Specifically, lean females had greater activations in the insula, inferior parietal cortex, cuneus, and supplementary motor area than obese females during stop as compared to go trials. This difference was caused by diminished brain activations in obese females in stop as compared to go trials. Furthermore, the brain activations in these regions inversely correlated to BMI across subjects. These preliminary findings suggest altered neural processes of cognitive control in obesity. 相似文献
175.
176.
Bhandari V Kulshrestha A Deep DK Stark O Prajapati VK Ramesh V Sundar S Schonian G Dujardin JC Salotra P 《PLoS neglected tropical diseases》2012,6(5):e1657
Background
With widespread resistance to antimonials in Visceral Leishmaniasis (VL) in the Indian subcontinent, Miltefosine (MIL) has been introduced as the first line therapy. Surveillance of MIL susceptibility in natural populations of Leishmania donovani is vital to preserve it and support the VL elimination program.Methodology and Principal Findings
We measured in vitro susceptibility towards MIL and paromomycin (PMM) in L. donovani isolated from VL and PKDL, pre- and post-treatment cases, using an amastigote-macrophage model. MIL susceptibility of post-treatment isolates from cured VL cases (n = 13, mean IC50±SD = 2.43±1.44 µM), was comparable (p>0.05) whereas that from relapses (n = 3, mean IC50 = 4.72±1.99 µM) was significantly higher (p = 0.04) to that of the pre-treatment group (n = 6, mean IC50 = 1.86±0.75 µM). In PKDL, post-treatment isolates (n = 3, mean IC50 = 16.13±2.64 µM) exhibited significantly lower susceptibility (p = 0.03) than pre-treatment isolates (n = 5, mean IC50 = 8.63±0.94 µM). Overall, PKDL isolates (n = 8, mean IC50 = 11.45±4.19 µM) exhibited significantly higher tolerance (p<0.0001) to MIL than VL isolates (n = 22, mean IC50 = 2.58±1.58 µM). Point mutations in the miltefosine transporter (LdMT) and its beta subunit (LdRos3) genes previously reported in parasites with experimentally induced MIL resistance were not present in the clinical isolates. Further, the mRNA expression profile of these genes was comparable in the pre- and post-treatment isolates. Parasite isolates from VL and PKDL cases were uniformly susceptible to PMM with respective mean IC50 = 7.05±2.24 µM and 6.18±1.51 µM.Conclusion
The in vitro susceptibility of VL isolates remained unchanged at the end of MIL treatment; however, isolates from relapsed VL and PKDL cases had lower susceptibility than the pre-treatment isolates. PKDL isolates were more tolerant towards MIL in comparison with VL isolates. All parasite isolates were uniformly susceptible to PMM. Mutations in the LdMT and LdRos3 genes as well as changes in the expression of these genes previously correlated with experimental resistance to MIL could not be verified for the field isolates. 相似文献177.
Purkinje cells are an attractive model system for studying dendritic development, because they have an impressive dendritic tree which is strictly oriented in the sagittal plane and develops mostly in the postnatal period in small rodents 3. Furthermore, several antibodies are available which selectively and intensively label Purkinje cells including all processes, with anti-Calbindin D28K being the most widely used. For viewing of dendrites in living cells, mice expressing EGFP selectively in Purkinje cells 11 are available through Jackson labs. Organotypic cerebellar slice cultures cells allow easy experimental manipulation of Purkinje cell dendritic development because most of the dendritic expansion of the Purkinje cell dendritic tree is actually taking place during the culture period 4. We present here a short, reliable and easy protocol for viewing and analyzing the dendritic morphology of Purkinje cells grown in organotypic cerebellar slice cultures. For many purposes, a quantitative evaluation of the Purkinje cell dendritic tree is desirable. We focus here on two parameters, dendritic tree size and branch point numbers, which can be rapidly and easily determined from anti-calbindin stained cerebellar slice cultures. These two parameters yield a reliable and sensitive measure of changes of the Purkinje cell dendritic tree. Using the example of treatments with the protein kinase C (PKC) activator PMA and the metabotropic glutamate receptor 1 (mGluR1) we demonstrate how differences in the dendritic development are visualized and quantitatively assessed. The combination of the presence of an extensive dendritic tree, selective and intense immunostaining methods, organotypic slice cultures which cover the period of dendritic growth and a mouse model with Purkinje cell specific EGFP expression make Purkinje cells a powerful model system for revealing the mechanisms of dendritic development. 相似文献
178.
Olivia L. Conner Greg J. Siegle Ashley M. McFarland Jennifer S. Silk Cecile D. Ladouceur Ronald E. Dahl James A. Coan Neal D. Ryan 《PloS one》2012,7(12)
Close proximity to an attachment figure, such as a caregiver, has been shown to attenuate threat-related activity in limbic regions such as the hypothalamus in healthy individuals. We hypothesized that such features might be similarly attenuated by proximity during a potentially stressful situation in a clinically anxious population of youths. Confirmation of this hypothesis could support the role of attachment figures in the management of anxiety among children and adolescents. Three groups were analyzed: anxious children and adolescents who requested that their caregiver accompany them in the scanner room, anxious children and adolescents without their caregiver in the scanner room and healthy controls (each of N = 10). The groups were matched for age and, among the two anxious groups, for diagnosis (mean age 9.5). The children and adolescents were exposed to physical threat words during an fMRI assessment. Results indicate that activity in the hypothalamus, ventromedial, and ventrolateral prefrontal cortex were significantly reduced in anxious children and adolescents who requested that their caregiver accompany them in the scanner room compared to those without their caregiver in the scanner room. Mean activity in these regions in anxious children and adolescents with their caregiver in the scanner room was comparable to that of healthy controls. These data suggest links between social contact and neural mechanisms of emotional reactivity; specifically, presence of caregivers moderates the increase in anxiety seen with stressful stimuli. Capitalizing on the ability of anxious youths to manifest low levels of anxiety-like information processing in the presence of a caregiver could help in modeling adaptive function in behavioral treatments. 相似文献
179.
Sophie Perrin Jonathan Cremer Olivia Faucher Jacques Reynes Pierre Dellamonica Jo?lle Micallef Caroline Solas Bruno Lacarelle Charlotte Stretti Elise Kaspi Andrée Robaglia-Schlupp Corine Nicolino-Brunet Catherine Tamalet Nicolas Lévy Isabelle Poizot-Martin Pierre Cau Patrice Roll 《PloS one》2012,7(12)
Background
The ANRS EP45 “Aging” study investigates the cellular mechanisms involved in the accelerated aging of HIV-1 infected and treated patients. The present report focuses on lamin A processing, a pathway known to be altered in systemic genetic progeroid syndromes.Methods
35 HIV-1 infected patients being treated with first line antiretroviral therapy (ART, mean duration at inclusion: 2.7±1.3 years) containing boosted protease inhibitors (PI/r) (comprising lopinavir/ritonavir in 65% of patients) were recruited together with 49 seronegative age- and sex-matched control subjects (http://clinicaltrials.gov/, ). In more than 88% of patients, the viral load was <40 copies/ml and the CD4+ cell count was >500/mm3. Prelamin A processing in peripheral blood mononuclear cells (PBMCs) from patients and controls was analysed by western blotting at inclusion. PBMCs from patients were also investigated at 12 and 24 months after enrolment in the study. PBMCs from healthy controls were also incubated with boosted lopinavir in culture medium containing various concentrations of proteins (4 to 80 g/L). NCT01038999Results
Lamin A precursor was not observed in cohort patient PBMC regardless of the PI/r used, the dose and the plasma concentration. Prelamin A was detected in PBMC incubated in culture medium containing a low protein concentration (4 g/L) but not in plasma (60–80 g/L) or in medium supplemented with BSA (40 g/L), both of which contain a high protein concentration.Conclusions
Prelamin A processing abnormalities were not observed in PBMCs from patients under the PI/r first line regimen. Therefore, PI/r do not appear to contribute to lamin A-related aging in PBMCs. In cultured PBMCs from healthy donors, prelamin A processing abnormalities were only observed when the protein concentration in the culture medium was low, thus increasing the amount of PI available to enter cells.ClinicalTrials.gov http://clinicaltrials.gov/ct2/show/ NCT01038999. NCT01038999相似文献180.
GJ Hermann E Scavarda AM Weis DS Saxton LL Thomas R Salesky H Somhegyi TP Curtin A Barrett OK Foster A Vine K Erlich E Kwan BM Rabbitts K Warren 《PloS one》2012,7(8):e43043
The human disease Hermansky-Pudlak syndrome results from defective biogenesis of lysosome-related organelles (LROs) and can be caused by mutations in subunits of the BLOC-1 complex. Here we show that C. elegans glo-2 and snpn-1, despite relatively low levels of amino acid identity, encode Pallidin and Snapin BLOC-1 subunit homologues, respectively. BLOC-1 subunit interactions involving Pallidin and Snapin were conserved for GLO-2 and SNPN-1. Mutations in glo-2 and snpn-1,or RNAi targeting 5 other BLOC-1 subunit homologues in a genetic background sensitized for glo-2 function, led to defects in the biogenesis of lysosome-related gut granules. These results indicate that the BLOC-1 complex is conserved in C. elegans. To address the function of C. elegans BLOC-1, we assessed the intracellular sorting of CDF-2::GFP, LMP-1, and PGP-2 to gut granules. We validated their utility by analyzing their mislocalization in intestinal cells lacking the function of AP-3, which participates in an evolutionarily conserved sorting pathway to LROs. BLOC-1(-) intestinal cells missorted gut granule cargo to the plasma membrane and conventional lysosomes and did not have obviously altered function or morphology of organelles composing the conventional lysosome protein sorting pathway. Double mutant analysis and comparison of AP-3(-) and BLOC-1(-) phenotypes revealed that BLOC-1 has some functions independent of the AP-3 adaptor complex in trafficking to gut granules. We discuss similarities and differences of BLOC-1 activity in the biogenesis of gut granules as compared to mammalian melanosomes, where BLOC-1 has been most extensively studied for its role in sorting to LROs. Our work opens up the opportunity to address the function of this poorly understood complex in cell and organismal physiology using the genetic approaches available in C. elegans. 相似文献