Longitudinal Study of Performance on the Ruff Figural Fluency Test in Persons Aged 35 Years or Older

The Ruff Figural Fluency Test (RFFT) is a cognitive test to measure executive function. Longitudinal studies have shown that repeated testing improves performance on the RFFT. Such a practice effect may hinder the interpretation of test results in a clinical setting. Therefore, we investigated the longitudinal performance on the RFFT in persons aged 35–82 years. Performance on the RFFT was measured three times over an average follow-up period of six years in 2,515 participants of the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) study in Groningen, the Netherlands: 53% men; mean age (SD), 53 (10) years. The effect of consecutive measurements on performance on the RFFT was investigated with linear multilevel regression models that also included age, gender, educational level and the interaction term consecutive measurement number x age as independent variables. It was found that the mean (SD) number of unique designs on the RFFT increased from 73 (26) at the first measurement to 79 (27) at the second measurement and to 83 (26) at the third measurement (p<0.001). However, the increase per consecutive measurement number was negatively associated with age and decreased with 0.23 per one-year increment of age (p<0.001). The increase per consecutive measurement number was not dependent on educational level. Similar results were found for the median (IQR) number of perseverative errors which showed a small but statistically significant increase with repeating testing: 7 (3–13) at the first measurement, 7 (4–14) at the second measurement and 8 (4–15) at the third measurement (p _trend = 0.002). In conclusion, the performance on the RFFT improved by repeating the test over an average follow-up period of three to six years. This practice effect was the largest in young adults and not dependent on educational level.     

Development of platelet inhibition by cAMP during megakaryocytopoiesis

Prostacyclin is a potent inhibitor of agonist-induced Ca2+ increases in platelets, but in the megakaryocytic cell line MEG-01 this inhibition is absent. Using human megakaryocytic cell lines representing different stages in megakaryocyte (Mk) maturation as well as stem cells and immature and mature megakaryocytes, we show that the inhibition by prostacyclin develops at a late maturation stage shortly before platelets are formed. This late appearance is not caused by insufficient cAMP formation or absent protein kinase A (PKA) activity in immature cells. Instead, the appearance of Ca2+ inhibition by prostacyclin is accompanied by a sharp increase in the expression of the catalytic subunit of PKA (PKA-C) but not by changes in the expression of the PKA-regulatory subunits Ialpha/beta, IIalpha, and IIbeta. Overexpression of PKA-C in the megakaryocytic cell line CHRF-288-11 potentiates the Ca2+ inhibition by prostacyclin. Thus, up-regulation of PKA-C appears to be a key step in the development of Ca2+ inhibition by prostacyclin in platelets.     

Physical Warmth and Perceptual Focus: A Replication of IJzerman and Semin (2009)

With the changing of modal research practices in psychology, the grounded cognition perspective (sometimes categorized under the more popular term of “social priming”) has become heavily criticized. Specifically, LeBel and Campbell (2013) reported a failed replication of a study involving what some would call “social priming.” We sought to replicate a study from our own lab (IJzerman & Semin, 2009), to investigate the reproducibility of the reported effect that physical warmth leads to a greater focus on perceptual relations. We also improved our methods to reduce potential experimenter''s bias (cf. Doyen, Klein, Pichon, & Cleeremans, 2012). We successfully replicated the finding that a simple cue of physical warmth makes people more likely to adopt a relational focus.     

No Evidence of Complementary Water Use along a Plant Species Richness Gradient in Temperate Experimental Grasslands

Niche complementarity in resource use has been proposed as a key mechanism to explain the positive effects of increasing plant species richness on ecosystem processes, in particular on primary productivity. Since hardly any information is available for niche complementarity in water use, we tested the effects of plant diversity on spatial and temporal complementarity in water uptake in experimental grasslands by using stable water isotopes. We hypothesized that water uptake from deeper soil depths increases in more diverse compared to low diverse plant species mixtures. We labeled soil water in 8 cm (with ¹⁸O) and 28 cm depth (with ²H) three times during the 2011 growing season in 40 temperate grassland communities of varying species richness (2, 4, 8 and 16 species) and functional group number and composition (legumes, grasses, tall herbs, small herbs). Stable isotope analyses of xylem and soil water allowed identifying the preferential depth of water uptake. Higher enrichment in ¹⁸O of xylem water than in ²H suggested that the main water uptake was in the upper soil layer. Furthermore, our results revealed no differences in root water uptake among communities with different species richness, different number of functional groups or with time. Thus, our results do not support the hypothesis of increased complementarity in water use in more diverse than in less diverse communities of temperate grassland species.     

Whole-body vibration improves cognitive functions of an adult with ADHD

Adult attention deficit hyperactivity disorder (ADHD) is associated with a variety of cognitive impairments, which were shown to affect academic achievement and quality of life. Current treatment strategies, such as stimulant drug treatment, were demonstrated to effectively improve cognitive functions of patients with ADHD. However, most treatment strategies are associated with a number of disadvantages in a considerable proportion of patients, such as unsatisfactory effects, adverse clinical side effects or high financial costs. In order to address limitations of current treatment strategies, whole-body vibration (WBV) might represent a novel approach to treat cognitive dysfunctions of patients with ADHD. WBV refers to the exposure of the whole body of an individual to vibration and was found to affect physiology and cognition. In the present study, WBV was applied on 10 consecutive days to an adult diagnosed with ADHD. Neuropsychological assessments were performed repeatedly at three different times, i.e., the day before the start of the treatment, on the day following completion of treatment and 14 days after the treatment have been completed (follow-up). An improved neuropsychological test performance following WBV treatment points to the high clinical value of WBV in treating patients with neuropsychological impairments such as ADHD.     

Directed Evolution of an Enantioselective Bacillus subtilis Lipase

Chiral compounds are of steadily increasing importance to the chemical industry, in particular for the production of pharmaceuticals. Where do these compounds come from? Apart from natural resources, two synthetic strategies are available: asymmetric chemical catalysis using transition metal catalysts and biocatalysis using enzymes. In the latter case, screening programs have identified a number of enzymes. However, their enantioselectivity is often not high enough for a desired reaction. This problem can be solved by applying directed evolution to create enantioselective enzymes as shown here for a lipase from Bacillus subtilis. The reaction studied was the asymmetric hydrolysis of meso-1,4-diacetoxy-2-cyclopentene with the formation of chiral alcohols which were detected by electrospray ionization mass spectrometry. Iterative cycles of random mutagenesis and screening allowed the identification of several variants with improved enantioselectivities. In parallel, we have started to use X-ray structural data to simulate the Bacillus subtilis lipase A-catalyzed substrate hydrolysis by using quantum mechanical and molecular mechanical calculations. This combined approach should finally enable us to devise more efficient strategies for the directed evolution of enantioselective enzymes.     

Ancient and essential: the assembly of iron-sulfur clusters in plants

In plants iron-sulfur (Fe-S) proteins are found in the plastids, mitochondria, cytosol and nucleus, where they are essential for numerous physiological and developmental processes. Recent mutant studies, mostly in Arabidopsis thaliana, have identified three pathways for the assembly of Fe-S clusters. The plastids harbor the SUF (sulfur mobilization) pathway and operate independently, whereas cluster assembly in the cytosol depends on the emerging CIA (cytosolic iron-sulfur cluster assembly) pathway and mitochondria. The latter organelles use the ISC (iron-sulfur cluster) assembly pathway. In all three pathways the assembly process can be divided into a first stage where S and Fe are combined on a scaffold protein, and a second stage in which the Fe-S cluster is transferred to a target protein. The second stage might involve different carrier proteins with specialized functions.     

Intravaginal practices, bacterial vaginosis, and HIV infection in women: individual participant data meta-analysis

Background

Identifying modifiable factors that increase women''s vulnerability to HIV is a critical step in developing effective female-initiated prevention interventions. The primary objective of this study was to pool individual participant data from prospective longitudinal studies to investigate the association between intravaginal practices and acquisition of HIV infection among women in sub-Saharan Africa. Secondary objectives were to investigate associations between intravaginal practices and disrupted vaginal flora; and between disrupted vaginal flora and HIV acquisition.

Methods and Findings

We conducted a meta-analysis of individual participant data from 13 prospective cohort studies involving 14,874 women, of whom 791 acquired HIV infection during 21,218 woman years of follow-up. Data were pooled using random-effects meta-analysis. The level of between-study heterogeneity was low in all analyses (I ² values 0.0%–16.1%). Intravaginal use of cloth or paper (pooled adjusted hazard ratio [aHR] 1.47, 95% confidence interval [CI] 1.18–1.83), insertion of products to dry or tighten the vagina (aHR 1.31, 95% CI 1.00–1.71), and intravaginal cleaning with soap (aHR 1.24, 95% CI 1.01–1.53) remained associated with HIV acquisition after controlling for age, marital status, and number of sex partners in the past 3 months. Intravaginal cleaning with soap was also associated with the development of intermediate vaginal flora and bacterial vaginosis in women with normal vaginal flora at baseline (pooled adjusted odds ratio [OR] 1.24, 95% CI 1.04–1.47). Use of cloth or paper was not associated with the development of disrupted vaginal flora. Intermediate vaginal flora and bacterial vaginosis were each associated with HIV acquisition in multivariable models when measured at baseline (aHR 1.54 and 1.69, p<0.001) or at the visit before the estimated date of HIV infection (aHR 1.41 and 1.53, p<0.001), respectively.

Conclusions

This study provides evidence to suggest that some intravaginal practices increase the risk of HIV acquisition but a direct causal pathway linking intravaginal cleaning with soap, disruption of vaginal flora, and HIV acquisition has not yet been demonstrated. More consistency in the definition and measurement of specific intravaginal practices is warranted so that the effects of specific intravaginal practices and products can be further elucidated. Please see later in the article for the Editors'' Summary     

Coordinated multidisciplinary care for ambulatory Huntington's disease patients. Evaluation of 18 months of implementation

Background

terminal deletions of the distal portion of the short arm of chromosome 3 cause a rare contiguous gene disorder characterized by growth retardation, developmental delay, mental retardation, dysmorphisms, microcephaly and ptosis. The phenotype of individuals with deletions varies from normal to severe. It was suggested that a 1,5 Mb minimal terminal deletion including the two genes CRBN and CNTN4 is sufficient to cause the syndrome. In addition the CHL1 gene, mapping at 3p26.3 distally to CRBN and CNTN4, was proposed as candidate gene for a non specific mental retardation because of its high level of expression in the brain.

Methods and Results

we describe two affected siblings in which array-CGH analysis disclosed an identical discontinuous terminal 3p26.3 deletion spanning less than 1 Mb. The deletion was transmitted from their normal father and included only the CHL1 gene. The two brothers present microcephaly, light mental retardation, learning and language difficulties but not the typical phenotype manifestations described in 3p- syndrome.

Conclusion

a terminal 3p26.3 deletion including only the CHL1 gene is a very rare finding previously reported only in one family. The phenotype of the affected individuals in the two families is very similar and the deletion has been inherited from an apparently normal parent. As already described for others recurrent syndromes with variable phenotype, these findings are challenging in genetic counselling because of an evident variable penetrance.