Real-time PCR detection chemistry

Real-time PCR is the method of choice in many laboratories for diagnostic and food applications. This technology merges the polymerase chain reaction chemistry with the use of fluorescent reporter molecules in order to monitor the production of amplification products during each cycle of the PCR reaction. Thus, the combination of excellent sensitivity and specificity, reproducible data, low contamination risk and reduced hand-on time, which make it a post-PCR analysis unnecessary, has made real-time PCR technology an appealing alternative to conventional PCR. The present paper attempts to provide a rigorous overview of fluorescent-based methods for nucleic acid analysis in real-time PCR described in the literature so far. Herein, different real-time PCR chemistries have been classified into two main groups; the first group comprises double-stranded DNA intercalating molecules, such as SYBR Green I and EvaGreen, whereas the second includes fluorophore-labeled oligonucleotides. The latter, in turn, has been divided into three subgroups according to the type of fluorescent molecules used in the PCR reaction: (i) primer-probes (Scorpions, Amplifluor, LUX, Cyclicons, Angler); (ii) probes; hydrolysis (TaqMan, MGB-TaqMan, Snake assay) and hybridization (Hybprobe or FRET, Molecular Beacons, HyBeacon, MGB-Pleiades, MGB-Eclipse, ResonSense, Yin-Yang or displacing); and (iii) analogues of nucleic acids (PNA, LNA, ZNA, non-natural bases: Plexor primer, Tiny-Molecular Beacon). In addition, structures, mechanisms of action, advantages and applications of such real-time PCR probes and analogues are depicted in this review.

Differences Between Elderly Women and Men in Cognitive Functioning and Quality of Life

Today, there is still some controversy about the influence of the variable sex on cognitive functioning and quality of life in old age. The main objective of the study presented is to analyze possible differences between older men and women in relation to their cognitive abilities and quality of life. The study sample consists of 264 persons aged between 65 and 95 years from the provinces of Jaen and Granada who were assessed with a cognitive screening test, a verbal fluency test, a task of sustained attention, a task to assess learning potential, a working memory task, and of quality of life questionnaire. The results show that, once the educational level and age of participants is controlled, men show superior performance on cognitive screening tasks, working memory, sustained attention and verbal fluency; while women performance above men in verbal memory tasks and verbal learning. In quality of life, men show better health and greater independence, while women scored higher than men on social integration and use of social services.

Study of a measles outbreak in Granada with preventive measures applied by the courts, Spain, 2010 to 2011

Binary file ES_Abstracts_Final_ECDC.txt matches

Abstract 2213: Influence of genetic polymorphism in UGT1A1, UGT1A7 and UGT1A9 on irinotecan, SN-38 and SN-38G pharmacokinetics

Background and objective: SN-38 is the active metabolite of irinotecan (CPT-11) and mainly responsible of hematological and intestinal toxicity after CPT-11 treatments. SN-38 is inactivated into SN-38G by uridine diphosphate glucuronosyltransferase (UGT) enzymes. Some polymorphism of these enzymes leads lower clearance (CL) of SN-38 and therefore bigger exposition and bigger risk of hematological and/or intestinal toxicity (1). Therefore, the goal of this study has been to evaluate the influence of genetic polymorphism in UGT1A1, UGT1A7 and UGT1A9 on the population pharmacokinetics of CPT-11 and its metabolites, SN-38 and SN-38G on Caucassian cancer population.

Methods: Plasma concentrations of CPT-11, SN-38 and SN-38G from 72 patients were pooled to develop a joint population pharmacokinetic model using NONMEM 7. The effect of age, sex, body surface area, total bilirubin, co-medication, tumor type, and UGT1A1, UGT1A7 and UGT1A9 genotypes on the model parameters was evaluated.

Results: The typical values (between-subject variability; %) of the irinotecan, SN-38 and SN-38G clearances were 42,9 L/h (56,4%), 1340 L/h (76,8%) and 188 L/h (70,1%), respectively. Clearance in patients with some allele (heterozygous or homozygous) associated with low enzymatic activity of UGT1A1*28 was a 35,7% lower (CI 95%: 6,7 - 64,7; p=0,003) than in wild-type patients. Additionally, linkage dissequilibrium indicates a strong interaction between functional UGT1A1, UGT1A7 and UGT1A9 polymorphisms related to the alteration of the UGT enzyme activity.

Conclusion: The impact of UGT1A1*28 genotype on the systemic exposure of SN-38 justifies its routine determination in patients receiving CPT-11 and subsequent dose adjustment.

Citation Format: Belen Valenzuela, Mario González-Sales, Vanessa Escudero, Elena Navarro, Carlos Perez-Ruixo, Joseba Rebollo, Ramon González-Manzano, Juan José Pérez-Ruixo. Influence of genetic polymorphism in UGT1A1, UGT1A7 and UGT1A9 on irinotecan, SN-38 and SN-38G pharmacokinetics. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2213. doi:10.1158/1538-7445.AM2013-2213

Training-induced changes in drag-flick technique in female field hockey players

The penalty corner is one of the most important goal plays in field hockey. The drag-flick is used less by women than men in a penalty corner. The aim of this study was to describe training-induced changes in the drag-flick technique in female field hockey players. Four female players participated in the study. The VICON optoelectronic system (Oxford Metrics, Oxford, UK) measured the kinematic parameters of the drag-flick with six cameras sampling at 250 Hz, prior to and after training. Fifteen shots were captured for each subject. A Wilcoxon test assessed the differences between pre-training and post-training parameters. Two players received specific training twice a week for 8 weeks; the other two players did not train. The proposed drills improved the position of the stick at the beginning of the shot (p < 0.05), the total distance of the shot (p < 0.05) and the rotation radius at ball release (p < 0.01). It was noted that all players had lost speed of the previous run. Further studies should include a larger sample, in order to provide more information on field hockey performance.

Protein kinase A regulatory subunit isoforms regulate growth and differentiation in Mucor circinelloides: essential role of PKAR4

The protein kinase A (PKA) signaling pathway plays a role in regulating growth and differentiation in the dimorphic fungus Mucor circinelloides. PKA holoenzyme is comprised of two catalytic (C) and two regulatory (R) subunits. In M. circinelloides, four genes encode the PKAR1, PKAR2, PKAR3, and PKAR4 isoforms of R subunits. We have constructed null mutants and demonstrate that each isoform has a different role in growth and differentiation. The most striking finding is that pkaR4 is an essential gene, because only heterokaryons were obtained in knockout experiments. Heterokaryons with low levels of wild-type nuclei showed an impediment in the emission of the germ tube, suggesting a pivotal role of this gene in germ tube emergence. The remaining null strains showed different alterations in germ tube emergence, sporulation, and volume of the mother cell. The pkaR2 null mutant showed an accelerated germ tube emission and was the only mutant that germinated under anaerobic conditions when glycine was used as a nitrogen source, suggesting that pkaR2 participates in germ tube emergence by repressing it. From the measurement of the mRNA and protein levels of each isoform in the wild-type and knockout strains, it can be concluded that the expression of each subunit has its own mechanism of differential regulation. The PKAR1 and PKAR2 isoforms are posttranslationally modified by ubiquitylation, suggesting another regulation point in the specificity of the signal transduction. The results indicate that each R isoform has a different role in M. circinelloides physiology, controlling the dimorphism and contributing to the specificity of cyclic AMP (cAMP)-PKA pathway.

Kinematic analysis of kicking in young top-class soccer players

AIM

The aim of this study was to describe the kinematic pattern of the kicking movement of young top-class soccer players focusing in examining the linear joint markers velocity of the leg kick and the segments angular position.

METHODS

Maximal in step kicks performed by 21 young top-class soccer players (16.1 ± 0.2 years) were analyzed using a three dimensional motion capture system.

RESULTS

The ball was released at a mean velocity of 30.6 ± 1.54 m/s. The maximum linear velocity of the hip (5.49 ± 0.53 m/s), knee (10.89 ± 0.63 m/s), ankle (19.36 ± 0.96 m/s) and toe (24.59 ± 1.33 m/s) joint markers were achieved consecutively during the kick, representing a typical proximal to distal kinetic chain. Significant (P<0.01) differences in the arms, trunk, thigh, shank and foot segments angular positions were found among the instant times in which the key events took place, determined by the maximum velocity of the hip (T1), knee (T2), ankle (T3) and toe (T4) joint markers (except between T3 and T4). This fact indicates that the instant time when each joint marker reached its maximum velocity implied different positions of the body segments.

CONCLUSION

The results of this study provide additional data about the kicking biomechanics of young top-class soccer players. This information should be taken in consideration by coaches that train young soccer players.

Prediction of preterm birth using the cervical consistency index

OBJECTIVES

To assess the diagnostic power of a new cervical consistency index (CCI) obtained using transvaginal sonography for the prediction of spontaneous preterm birth (PTB) and to establish reference ranges for this new variable.

METHODS

Included in this prospective cross-sectional study were 1115 singleton pregnancies at 5-36 weeks of gestation. Anteroposterior cervical diameter was measured before (AP) and after (AP') application of pressure on the cervix using the transvaginal probe. The index was calculated using the formula: CCI=((AP'/AP) × 100). Cervical length was also measured. The outcomes evaluated were spontaneous PTB before 32, 34 and 37 weeks. Logistic regression and analysis of receiver-operating characteristics (ROC) curves were performed to evaluate the diagnostic power of CCI and cervical length (adjusted for gestational age). Intraclass correlation coefficients (ICCs) and Bland-Altman analysis were used to evaluate intra- and interobserver variability.

RESULTS

In the 1031 women with follow-up, the rate of spontaneous PTB before 32 weeks was 0.87%, before 34 weeks was 2.13% and before 37 weeks was 7.76% (n=80). There were 31 (3.01%) iatrogenic PTBs before 37 weeks. An inverse linear correlation between gestational age and CCI was observed, with regression equation: CCI (in %)=89.8 - 1.35 × (GA in weeks); r(2)=0.66, P<0.001. Cervical length showed an inverse quadratic, though non-significant, relationship with gestational age: CL (in mm)=31.084 - 0.0278× (GA in weeks)(2) + 1.0772× (GA in weeks); r(2)=0.076, P<0.14. The intra- and interobserver ICCs for CCI were 0.99 (95% CI, 0.988-0.994) and 0.98 (95% CI, 0.973-0.987), respectively. The area under the ROC curve for CCI in the prediction of spontaneous PTB before 32 weeks was 0.947, for spontaneous PTB before 34 weeks it was 0.943 and for spontaneous PTB before 37 weeks it was 0.907. For a 5% screen-positive rate, CCI had a sensitivity of 67%, 64% and 45% for prediction of spontaneous PTB before 32, 34 and 37 weeks, respectively, with equivalent values of 11%, 9% and 11% for cervical length.

CONCLUSIONS

CCI shows a clear inverse linear relationship with GA. Assessment of CCI is reproducible and is effective in the prediction of spontaneous PTB. This new variable appears to provide better prediction of spontaneous PTB than does cervical length.

Differences in cognitive performance, level of dependency and quality of life (QoL), related to age and cognitive status in a sample of Spanish old adults under and over 80 years of age

The main objective of this study was to analyze the similarities and differences in cognitive performance, level of dependency, cognitive plasticity and QoL in a sample of young-old adults and old-old adults, bearing in mind both the age-group (under or over 80 years) and the cognitive status of the participants. The study population consisted of 220 people living in sheltered accommodation for elderly people in the South of Spain, with an average age of 80.75 years. Participants were evaluated by means of cognitive performance tests, a QoL questionnaire, a depression scale and a dependency assessment scale. The results indicate that the main differences in the variables analyzed are due to the cognitive status of the sample and not to the fact that the participants are under or over 80 years of age. The findings show that major inter-individual differences in this stage of life depend not only on age but also on cognitive status, which is thus an important factor to take into account when working with this sector of the population.

Morphology Analysis of Si Island Arrays on Si(001)

The formation of nanometer-scale islands is an important issue for bottom-up-based schemes in novel electronic, optoelectronic and magnetoelectronic devices technology. In this work, we present a detailed atomic force microscopy analysis of Si island arrays grown by molecular beam epitaxy. Recent reports have shown that self-assembled distributions of fourfold pyramid-like islands develop in 5-nm thick Si layers grown at substrate temperatures of 650 and 750°C on HF-prepared Si(001) substrates. Looking for wielding control and understanding the phenomena involved in this surface nanostructuring, we develop and apply a formalism that allows for processing large area AFM topographic images in a shot, obtaining surface orientation maps with specific information on facets population. The procedure reveals some noticeable features of these Si island arrays, e.g. a clear anisotropy of the in-plane local slope distributions. Total island volume analysis also indicates mass transport from the substrate surface to the 3D islands, a process presumably related to the presence of trenches around some of the pyramids. Results are discussed within the framework of similar island arrays in homoepitaxial and heteroepitaxial semiconductor systems.

[Spanish version of the CAM-ICU (Confusion Assessment Method for the Intensive Care Unit). Pilot study of validation]

OBJECTIVE

To validate the Spanish version of the CAM-ICU.

DESIGN

Validation study. The inter-rater reliability and validity were evaluated using a blind comparison with the DSM-IVTR criteria (reference standard) in a group of patients hospitalized in an Intensive Care Unit (ICU).

SETTING

Medical-surgical ICU.

PATIENTS

129 adults with RASS >-4 score, within the 24-48 h of ICU admission. Independent application of the CAM-ICU by two intensive care specialists and evaluation by a psychiatrist using the DSM-IVTR criteria for delirium.

RESULTS

Prevalence of delirium in the sample was 26.4%, this being and 48.3% in the 29 patients who received mechanical ventilation. Inter-rater reliability in the whole sample according to the Kappa index was 0.792 (95% CI 0.662-0.922, p<0.001) and in those who received mechanical ventilation was 0.726 (95% CI 0.487-0.965, p<0.001). The sensitivity, specificity, positive predicted value (PPV), negative predicted value (NPV), positive likelihood ratio (+LR), and negative likelihood ratio (-LR) were 79.4% (95% CI 63.2-89.7%); 97.9% (95% CI 92.6-99.4%); 93.1% (95% CI 78.0-98.1%); 93.0% (95% CI 86.3-96.6%); 37.72 (95% CI 9.47-150.20) and 0.21(95% CI 0.11-0.41), respectively, in the whole sample. In mechanically-ventilated patients, sensitivity, specificity, PPV, NPV, +LR and -LR were 92.9% (95% CI 68.5-98.7%); 86.7% (95% CI 62.1-96.3%); 86.7% (95% CI 62.1-96.3%); 92.9% (95% CI 68.5-98.7%); 6.96(95% CI 1.90-25.51) and 0.08 (95% CI 0.01-0.55), respectively.

CONCLUSION

The Spanish version of the CAM-ICU is reliable. Its sensitivity, specificity and predictive values should be considered good.