Midgut epithelium formation in Thermobia domestica (Packard) (Insecta, Zygentoma)

The origin of midgut epithelium may begin either from yolk cells (energids), tips of stomo- and proctodaeum (ectoderm), inner layer (endoderm) or from both kinds of the above mentioned cells. The origin of the midgut epithelium in wingless insects (Apterygota) has still not been determined. In Thermobia domestica the formation of midgut is much delayed, and it completes in the post-embryonic stage, while the stomo- and the proctodaeum are well-developed in the embryonic period. The energids, which remain inside the yolk, start to migrate to its periphery, where they arrange singly close to cell membrane. The yolk mass with the energids at the 14th day of embryogenesis are referred to as the primary midgut. During the first instar larval stage more and more energids migrate to the yolk periphery and the cell membrane starts to form numerous foldings surrounding the groups of energids, which in turn lead to formation of isolated regenerative cell groups. Eventually the cell membrane invaginations reach the center of the yolk mass. Large cells of the primary epithelium, surrounding the newly formed midgut lumen are formed. The cells of the primary epithelium are filled with yolk and are equipped with microvilli pointing to the midgut lumen. As the yolk is being digested, the process of the primary epithelium cells degeneration begins. The cells are getting shorter and start to degenerate. The definitive midgut epithelium is formed from proliferating regenerative cells. It consists of regularly spaced regenerative cell groups as well as the epithelial cells. The ultrastructure of both these cell groups has been described.     

Environmental origins of sexually selected variation and a critique of the fluctuating asymmetry-sexual selection hypothesis

Identifying sources of phenotypic variability in secondary sexual traits is critical for understanding their signaling properties, role in sexual selection, and for predicting their evolutionary dynamics. The present study tests for the effects of genotype, developmental temperature, and their interaction, on size and fluctuating asymmetry of the male sex comb, a secondary sexual character, in Drosophila bipectinata Duda. Both the size and symmetry of elements of the sex comb have been shown previously to be under sexual selection in a natural population in northeastern Australia. Two independent reciprocal crosses were conducted at 25 degrees and 29 degrees C between genetic lines extracted from this population that differed in the size of the first (TC1) and third (TC3) comb segments. These temperatures are within the documented range experienced by the species in nature. Additive and dominance genetic effects were detected for TC1, whereas additive genetic, and Y-chromosomal effects were detected for TC3. TC2 and TC3 decreased sharply with increasing temperature, by 10% and 22%, respectively. In contrast, positional fluctuating asymmetry (PFA) significantly increased with temperature, by up to 38%. The results (1) document an important source of environmental variance in a sexual ornament expected to reduce trait heritability in field populations, and thus act to attenuate response to sexual selection, (2) suggest that variation in ornament size reflects differences in male condition; and (3) support the general hypothesis that asymmetry in a sexual ornament is indicative of developmental instability arising from environmental stress. The "environmental heterogeneity" (EH) hypothesis is proposed, and supportive evidence for it presented, to explain negative size-FA correlations in natural populations. Data and theory challenge the use of negative size-FA correlations observed in nature to support the FA-sexual selection hypothesis, which posits that such correlations are driven by differences in genetic quality among individuals.     

Airway cellularity, lipid laden macrophages and microbiology of gastric juice and airways in children with reflux oesophagitis

Background and methods

Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR.

Results

We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 × 10⁵ viral copies/ml in nasal lavage and 1.88 × 10⁵ viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD.

Conclusion

HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely.     

Reliability of computerized image analysis for the evaluation of serial synovial biopsies in randomized controlled trials in rheumatoid arthritis

Analysis of biomarkers in synovial tissue is increasingly used in the evaluation of new targeted therapies for patients with rheumatoid arthritis (RA). This study determined the intrarater and inter-rater reliability of digital image analysis (DIA) of synovial biopsies from RA patients participating in clinical trials. Arthroscopic synovial biopsies were obtained before and after treatment from 19 RA patients participating in a randomized controlled trial with prednisolone. Immunohistochemistry was used to detect CD3⁺ T cells, CD38⁺ plasma cells and CD68⁺ macrophages. The mean change in positive cells per square millimetre for each marker was determined by different operators and at different times using DIA. Nonparametric tests were used to determine differences between observers and assessments, and to determine changes after treatment. The intraclass correlations (ICCs) were calculated to determine the intrarater and inter-rater reliability. Intrarater ICCs showed good reliability for measuring changes in T lymphocytes (R = 0.87), plasma cells (R = 0.62) and macrophages (R = 0.73). Analysis by Bland–Altman plots showed no systemic differences between measurements. The smallest detectable changes were calculated and their discriminatory power revealed good response in the prednisolone group compared with the placebo group. Similarly, inter-rater ICCs also revealed good reliability for measuring T lymphocytes (R = 0.68), plasma cells (R = 0.69) and macrophages (R = 0.72). All measurements identified the same cell types as changing significantly in the treated patients compared with the placebo group. The measurement of change in total positive cell numbers in synovial tissue can be determined reproducibly for various cell types by DIA in RA clinical trials.     

Genomewide linkage analysis for internal carotid artery intimal medial thickness: evidence for linkage to chromosome 12

Carotid intimal medial thickness (IMT) is a heritable quantitative measure of atherosclerosis. A genomewide linkage analysis was conducted to localize a quantitative-trait locus (QTL) influencing carotid IMT. Carotid IMT was measured in 596 men and 629 women from 311 extended families (1,242 sib pairs) in the Framingham Heart Study Offspring cohort. B-mode carotid ultrasonography was used to define mean IMT of the carotid artery segments. Multipoint variance-component linkage analysis was performed. Evidence for significant linkage to internal carotid artery (ICA) IMT (two-point log odds [LOD] score 4.1, multipoint LOD score 3.4) was found 161 cM from the tip of the short arm of chromosome 12; these results were confirmed using the GENEHUNTER package (multipoint LOD score 4.3). No LOD scores >2.0 were observed for common carotid artery (CCA) IMT. Association analysis of a single-nucleotide-polymorphism variant of SCARB1 (minor allele frequency 0.13), a gene in close proximity to the region of peak linkage, revealed a protective association of the missense variant allele in exon 1 of SCARB1, with decreased ICA IMT compared with subjects homozygous for the common allele. Although the exon 1 variant contributed 2% to overall variation in ICA IMT, there was no significant change in the peak LOD score after adjustment in the linkage analyses. These data provide substantial evidence for a QTL on chromosome 12 influencing ICA IMT and for association of a rare variant of SCARB1, or a nearby locus, with ICA IMT. Because this rare SCARB1 variant does not account for our observed linkage, further investigations are warranted to identify additional candidate-gene variants on chromosome 12 predisposing to atherosclerosis phenotypes and clinical vascular disease.     

Screening of MAMLD1 mutations in 70 children with 46,XY DSD: identification and functional analysis of two new mutations

More than 50% of children with severe 46,XY disorders of sex development (DSD) do not have a definitive etiological diagnosis. Besides gonadal dysgenesis, defects in androgen biosynthesis, and abnormalities in androgen sensitivity, the Mastermind-like domain containing 1 (MAMLD1) gene, which was identified as critical for the development of male genitalia, may be implicated. The present study investigated whether MAMLD1 is implicated in cases of severe 46,XY DSD and whether routine sequencing of MAMLD1 should be performed in these patients.Seventy children with severe non-syndromic 46,XY DSD of unknown etiology were studied. One hundred and fifty healthy individuals were included as controls. Direct sequencing of the MAMLD1, AR, SRD5A2 and NR5A1 genes was performed. The transactivation function of the variant MAMLD1 proteins was quantified by the luciferase method.TWO NEW MUTATIONS WERE IDENTIFIED: p.S143X (c.428C>A) in a patient with scrotal hypospadias with microphallus and p.P384L (c.1151C>T) in a patient with penile hypospadias with microphallus. The in vitro functional study confirmed no residual transactivating function of the p.S143X mutant and a significantly reduced transactivation function of the p.P384L protein (p = 0.0032). The p.P359S, p.N662S and p.H347Q variants are also reported with particularly high frequency of the p.359T- p.662G haplotype in the DSD patients.Severe undervirilization in XY newborns can reveal mutations of MAMLD1. MAMLD1 should be routinely sequenced in these patients with otherwise normal AR, SRD5A2 and NR5A1genes.     

Valid and reliable instruments for arm-hand assessment at ICF activity level in persons with hemiplegia: a systematic review

Background

Loss of arm-hand performance due to a hemiparesis as a result of stroke or cerebral palsy (CP), leads to large problems in daily life of these patients. Assessment of arm-hand performance is important in both clinical practice and research. To gain more insight in e.g. effectiveness of common therapies for different patient populations with similar clinical characteristics, consensus regarding the choice and use of outcome measures is paramount. To guide this choice, an overview of available instruments is necessary. The aim of this systematic review is to identify, evaluate and categorize instruments, reported to be valid and reliable, assessing arm-hand performance at the ICF activity level in patients with stroke or cerebral palsy.

Methods

A systematic literature search was performed to identify articles containing instruments assessing arm-hand skilled performance in patients with stroke or cerebral palsy. Instruments were identified and divided into the categories capacity, perceived performance and actual performance. A second search was performed to obtain information on their content and psychometrics.

Results

Regarding capacity, perceived performance and actual performance, 18, 9 and 3 instruments were included respectively. Only 3 of all included instruments were used and tested in both patient populations. The content of the instruments differed widely regarding the ICF levels measured, assessment of the amount of use versus the quality of use, the inclusion of unimanual and/or bimanual tasks and the inclusion of basic and/or extended tasks.

Conclusions

Although many instruments assess capacity and perceived performance, a dearth exists of instruments assessing actual performance. In addition, instruments appropriate for more than one patient population are sparse. For actual performance, new instruments have to be developed, with specific focus on the usability in different patient populations and the assessment of quality of use as well as amount of use. Also, consensus about the choice and use of instruments within and across populations is needed.     

Elevated levels of fibrinogen-derived endogenous citrullinated peptides in synovial fluid of rheumatoid arthritis patients

Introduction

Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammation of the joints and the presence of autoantibodies directed against proteins containing the non-standard arginine-derived amino acid citrulline. The protein fibrinogen, which has an essential role in blood clotting, is one of the most prominent citrullinated autoantigens in RA, particularly because it can be found in the inflamed tissue of affected joints. Here, we set out to analyze the presence of citrullinated endogenous peptides in the synovial fluid of RA and arthritic control patients.

Methods

Endogenous peptides were isolated from the synovial fluid of RA patients and controls by filtration and solid phase extraction. The peptides were identified and quantified using high-resolution liquid chromatography-mass spectrometry.

Results

Our data reveal that the synovial fluid of RA patients contains soluble endogenous peptides, derived from fibrinogen, containing significant amounts of citrulline residues and, in some cases, also phosphorylated serine. Several citrullinated peptides are found to be more abundantly present in the synovial fluid of RA patients compared to patients suffering from other inflammatory diseases affecting the joints.

Conclusions

The increased presence of citrullinated peptides in RA patients points toward a possible specific role of these peptides in the immune response at the basis of the recognition of citrullinated peptides and proteins by RA patient autoantibodies.