Sequence variation and haplotype structure at the putative flowering-time locus COL1 of Brassica nigra

Motivated by a previous study indicating that polymorphism at an indel, Ind2, within the Brassica nigra COL1 gene is significantly associated with flowering time, we searched for evidence of selection in a sample of 41 complete sequences of B. nigra COL1. The within-gene population recombination rate is moderate, and all neutrality tests used in the present study failed to detect departure from the standard neutral model or evidence of selection. The haplotype structure of the 5'-half of the gene is primarily associated with the demographic history of the species and more specifically with the split between European and Ethiopian populations, whereas the structure of the 3'-half reflects the polymorphism at Ind2. This could be the result of selection or a combination of recombination and migration during the history of the sample of sequences. Without additional information on polymorphism in flanking areas, these two alternatives are difficult to tell apart. If selection acted on the gene, we suggest that if the indel itself is not the target of selection, among the polymorphic sites cosegregating with the polymorphism at Ind2, replacement polymorphisms around sites 890 and 1260 are the most likely quantitative trait nucleotides within the gene.     

Interventions led by nurse continence advisers in the management of urinary incontinence: a randomized controlled trial

Background

The short-term efficacy of combined lifestyle and behavioural interventions led by nurses in the management of urinary incontinence has not been rigorously evaluated by randomized controlled trial. We conducted a 6-month randomized controlled trial to determine whether a model of service delivery that included lifestyle and behavioural interventions led by “nurse continence advisers” in collaboration with a physician with expertise in continence management could reduce urinary incontinence and pad use in an outpatient population. We also aimed to evaluate the impact of this approach on subjects'' knowledge about incontinence and their quality of life.

Methods

We used advertising in the mainstream media, newsletters to family physicians and community information sessions in 1991 to invite volunteers who were 26 years of age or older and suffered from incontinence to participate in a randomized controlled trial. Men and women who met the eligibility criteria were randomly allocated to receive either counselling from specialized nurses to manage incontinence using behavioural and lifestyle modification sessions every 4 weeks for 25 weeks or usual care. Symptoms of incontinence and the use of incontinence pads were the primary outcome measures.

Results

Using sealed envelopes, 421 patients were randomly allocated to the treatment or control groups. On average, patients in the treatment group experienced 2.1 “incontinent events” per 24 hours before treatment and 1.0 incontinent event per 24 hours at the end of the study. Control patients had an average of 2.4 incontinent events per 24 hours before the study and 2.2 incontinent events per 24 hours at the end of the study. The mean decrease in events in the treatment group was 1.2 and in the control group 0.2 (p = 0.001). Pad use declined from a mean of 2.2 per 24 hours before randomization in the treatment group to 1.2 per 24 hours at the end of the study, compared with 2.6 pads per 24 hours in the control group at the start of the study and 2.4 per 24 hours at the end. Pad use per 24 hours decreased on average by 0.9 pads in the treatment group and 0.1 in the control group (p = 0.021).

Interpretation

Behavioural and lifestyle counselling provided by specialized nurses with training in managing incontinence reduces incontinent events and incontinence pad use.Urinary incontinence primarily affects young-to-middle-aged women and elderly men and women. The prevalence of urinary incontinence in people aged 65 years and older living in the community ranges from 8% to 30%.^1,2,3,4,5,6 Urinary incontinence is underrecognized and those affected are often embarrassed and ashamed, thus, the problem frequently remains hidden.^1,2North American and Canadian practice guidelines for the effective management of adult urinary incontinence have advocated thorough initial assessment, then staged multidisciplinary approaches beginning with the least invasive and reversible (lifestyle and behavioural) interventions, before drug therapy (reversible) and surgery (invasive and irreversible).^1,2,3 The role of continence advisers in the management of urinary incontinence has evolved from its early beginnings in the United Kingdom^7,8,9,10,11 and is now increasingly recognized in North America.^12,13,14 There has been some evaluation of the short-term efficacy of multidisciplinary incontinence management by nurse practitioners or “nurse continence advisers” in community and outpatient settings.^{15,16,17,18,19,20} However, the short-term efficacy of combined lifestyle and behavioural interventions led by nurse continence advisers has not been rigorously evaluated using randomized controlled trials.Urinary incontinence has many causes, particularly in elderly people,²¹ and the potential for overall clinical improvement is greater when multiple interventions target several factors. Each intervention effects a small positive change, and these small changes cumulatively have a large positive outcome.²¹ Individual components of lifestyle and behavioural interventions are increasingly being shown to be effective. For example, behavioural training, including pelvic muscle exercises, has reduced urinary incontinence significantly,^22,23,24 in some cases up to 57%.²⁵ A combined approach consisting of both bladder training and pelvic muscle exercises, provided by trained registered nurses, has resulted in significantly fewer incontinent episodes than either approach alone.²⁶ Pelvic floor exercises have been shown to be equally effective in women with stress, urge and mixed urinary incontinence.²⁷ Adherence to pelvic floor muscle exercises has been shown to be sustained for up to 5 years in 70% of women who have intensive exercise training.²⁸ Decreasing caffeine intake has also been shown to reduce episodes of incontinence.²⁹ Reducing fluid intake in people with detrusor instability, but not those with genuine stress incontinence, reduces the number of “incontinent events.” Increasing fluid intake makes the urinary incontinence worse.³⁰Our 6-month randomized controlled trial was conducted to determine whether a model of service delivery that included lifestyle and behavioural interventions led by nurse continence advisers in collaboration with a physician with expertise in continence management could reduce urinary incontinence and pad use. Our secondary aim was to investigate the impact of incontinence management led by nurse continence advisers on subjects'' knowledge about incontinence and their quality of life.     

Assessing the Relationship between Lung Density and Function with Oxygen-Enhanced Magnetic Resonance Imaging in a Mouse Model of Emphysema

Purpose

A magnetic resonance imaging method is presented that allows for the simultaneous assessment of oxygen delivery, oxygen uptake, and parenchymal density. The technique is applied to a mouse model of porcine pancreatic elastase (PPE) induced lung emphysema in order to investigate how structural changes affect lung function.

Method

Nine-week-old female C57BL6 mice were instilled with saline or PPE at days 0 and 7. At day 19, oxygen delivery, oxygen uptake, and lung density were quantified from T1 and proton-density measurements obtained via oxygen-enhanced magnetic resonance imaging (OE-MRI) using an ultrashort echo-time imaging sequence. Subsequently, the lungs were sectioned for histological observation. Blood-gas analyses and pulmonary functional tests via FlexiVent were performed in separate cohorts.

Principal Findings

PPE-challenged mice had reduced density when assessed via MRI, consistent with the parenchyma loss observed in the histology sections, and an increased lung compliance was detected via FlexiVent. The oxygenation levels, as assessed via the blood-gas analysis, showed no difference between PPE-challenged animals and control. This finding was mirrored in the global MRI assessments of oxygen delivery and uptake, where the changes in relaxation time indices were matched between the groups. The heterogeneity of the same parameters however, were increased in PPE-challenged animals. When the oxygenation status was investigated in regions of varying density, a reduced oxygen-uptake was found in low-density regions of PPE-challenged mice. In high-density regions the uptake was higher than that of regions of corresponding density in control animals. The oxygen delivery was proportional to the oxygen uptake in both groups.

Conclusions

The proposed method allowed for the regional assessment of the relationship between lung density and two aspects of lung function, the oxygen delivery and uptake. When compared to global indices of lung function, an increased sensitivity for detecting heterogeneous lung disorders was found. This indicated that the technique has potential for early detection of lung dysfunction–before global changes occur.     

Malaria‐derived hemozoin exerts early modulatory effects on the phenotype and maturation of human dendritic cells

Plasmodium falciparum (P. falciparum)‐induced effects on the phenotype of human dendritic cells (DC) could contribute to poor induction of long‐lasting protective immunity against malaria. DC ability to present antigens to naïve T cells, thus initiating adaptive immune responses depends on complex switches in chemokine receptors, production of soluble mediators and expression of molecules enabling antigen‐presentation and maturation. To examine the cellular basis of these processes in the context of malaria, we performed detailed analysis of early events following exposure of human monocyte‐derived DC to natural hemozoin (nHZ) and the synthetic analog of its heme core, β‐hematin. DC exposed to either molecule produced high levels of the inflammatory chemokine MCP‐1, showed continuous high expression of the inflammatory chemokine receptor CCR5, no upregulation of the lymphoid homing receptor CCR7 and no cytoskeletal actin redistribution with loss of podosomes. DC partially matured as indicated by increased expression of major histocompatibility complex (MHC) class II and CD86 following nHZ and β‐hematin exposure, however there was a lack in expression of the maturation marker CD83 following nHZ but not β‐hematin exposure. Overall our data demonstrate that exposure to nHZ partially impairs the capacity of DC to mature, an effect in part differential to β‐hematin.     

Identification of human satellite DNA sequences associated with chemically resistant nonhistone polypeptide adducts

A fraction of DNA fragments of highly purified and completely unfolded eukaryotic DNA inevitably remains associated with chemically resistant nonhistone DNA-polypeptide complexes. This fraction can be isolated by nitrocellulose filtration because the polypeptide-associated DNA fragments are retained on nitrocellulose filters while bulk DNA passes through the filters. The fraction of AluI-fragmented DNA from human placenta retained on filters as a result of the binding factors (R-DNA, 12%) represents a subset of genomic sequences with a sequence complexity different from unfractionated DNA and DNA recovered in the filtrate (F-DNA). DNA sequences prevalent in the retained fraction were detected by differential plaque hybridization of a recombinant gt10 library with radiolabeled F- and R-DNA fractions. Several recombinant phages showing much stronger hybridization signals with the R-DNA probe than with the F-DNA probe were selected, plaque-purified and analyzed. Analysis of the inserts of such clones showed that repetitive DNA sequences of the alphoid dimeric and tetrameric family, satellite III and satellite III-like sequences are highly enriched in the retained fraction, which indicates that these sequences specifically attract the polypeptides involved in the tightly bound and resistant complexes. This property of repetitive sequences is of interest since tandemly repetitive sequences have been suggested to code for locus-specific fixation and stabilization of the chromatin fiber in the cell nucleus.by L. ManuelidisThis work contains parts of the Ph.D. thesis of M.P. (University of Giessen).     

Chromosome ends in Chironomus pallidivittatus contain different subfamilies of telomere-associated repeats

Tandemly repeated 340 bp sequences, TA repeats, are present in seven of the eight pairs of chromosome ends in Chironomus pallidivittatus, being absent from the telocentric left end of chromosome four. We have previously shown that the family of TA repeats consists of four main subfamilies. One subfamily is composed of a master unit and the other three contain derived units, each of which has a small region where the master sequence is highly mutated. Here we find that there are considerable variations in numbers of TA repeats between animals and for the same telomere in different animals. We also show that the seven telomere pairs containing TA repeats differ with regard to the content of derived subfamilies. The master unit is probably present in all seven pairs. Two of the derived units are exclusively present in two telomere pairs. The third derived unit shows a more irregular distribution. Some of the telomeres have highly variable contents of such units among animals. Subfamilies thus have different behaviour as reflected in their stable and variable patterns of distribution between individual telomeres.W. Hennig     

Affinity labeling of rabbit skeletal muscle phosphorylase kinase by 5′-(p-fluorosulfonylbenzoyl)adenosine

Simple mixing of acid purified histones H₃ and H₄ in equimolar quantities at low ionic strength near pH 7 does not yield the tetramer but rather a high M_r aggregate. Dialysis of acid extracted total or core histones into 2 M NaCl 150 mM phosphate (pH 7.4) followed by fractionation of the histone complexes at lower ionic strength (150 mM NaCl) results in an H₃H₄ tetramer of a structure identical to that derived from salt-extracted histones. Dialysis of acid extracted total or core histones directly into the lower ionic strength buffer with subsequent fractionation, results in H₃H₄ tetramer of closely similar structure.     

Reduced neuron-specific expression of the TAF1 gene is associated with X-linked dystonia-parkinsonism

X-linked dystonia-parkinsonism (XDP) is a movement disorder endemic to the Philippines. The disease locus, DYT3, has been mapped to Xq13.1. In a search for the causative gene, we performed genomic sequencing analysis, followed by expression analysis of XDP brain tissues. We found a disease-specific SVA (short interspersed nuclear element, variable number of tandem repeats, and Alu composite) retrotransposon insertion in an intron of the TATA-binding protein-associated factor 1 gene (TAF1), which encodes the largest component of the TFIID complex, and significantly decreased expression levels of TAF1 and the dopamine receptor D2 gene (DRD2) in the caudate nucleus. We also identified an abnormal pattern of DNA methylation in the retrotransposon in the genome from the patient's caudate, which could account for decreased expression of TAF1. Our findings suggest that the reduced neuron-specific expression of the TAF1 gene is associated with XDP.     

Associations between the IL-4 -590 T allele and Plasmodium falciparum infection prevalence in asymptomatic Fulani of Mali

In this study, we compared the genotype and allele frequencies of the IL-10 -1087 A/G and IL-4 -590 C/T single nucleotide polymorphisms in asymptomatic subjects of two sympatric ethnic tribes differing in susceptibility to malaria, the Fulani and the Dogon in Mali. The genotype data was correlated with ethnicity and malariometric indexes. A statistically significant inter-ethnic difference in allele and genotype frequency for both loci was noted (P<0.0001). Within the Fulani, the prevalence of Plasmodium falciparum infection, as detected by both microscopy and PCR, was associated with the IL-4 -590 T allele (P=0.005 and P=0.0005, respectively), whereas, no such associations were seen in the Dogon. Inter-ethnic differences in spleen rates, higher in the Fulani than the Dogon, were seen between T carriers (TT and CT) of both groups (P<0.0001). Parasite densities and number of concurrent clones did not vary between IL-4 genotypes within any of the studied groups. These results suggest an association between the IL-4 -590 T allele and P. falciparum prevalence within the Fulani but not the Dogon. No associations between IL-10 genotypes and studied malariometric indexes were observed in any of the two communities.