Intraepithelial lymphocyte immunophenotype: a useful tool in the diagnosis of celiac disease

According to new ESPGHAN guidelines, gluten challenge is considered necessary when there is doubt about the initial diagnosis of celiac disease (CD). The main aim of this study was to quantify intraepithelial lymphocyte (IEL) immunophenotype on celiac patients on gluten-containing diet (GCD) compared to those on gluten-free diet (GFD). Another aim was to evaluate the clinical utility of IELs in the CD diagnosis, especially in selected patients on GFD where diagnostic uncertainty remains. IEL immunophenotype (TCRγδ and NK-like IELs) were studied by flow cytometry in 111 children with CD (81 children with CD on GCD and 30 celiac patients on GFD) and a control group (10 children). Duration of GFD was 5.4 ± 1.6 years. TCRγδ IELs in celiac patients receiving a GCD or GFD were significantly higher (p < 0.001) than in the control group. NK-like IELs in patients receiving a GCD or GFD were significantly lower than in the control group (p < 0.001). We observed a permanent decrease of NK-like IELs and an increment of TCRγδ IELs after following an adequate establishment and compliance of a long-term GFD in celiac patients. Recognition of IELs changes in the intestinal mucosa on celiac patients after long-term establishment of a GFD could constitute a useful tool for CD diagnosis in various situations: in which there is doubt about the initial diagnosis and repeat biopsy is necessary (avoiding the need of gluten challenges), and in those patients with symptoms/signs suggestive of CD who maintain a low gluten diet.     

Complex behaviour by coral-reef fish larvae in open-water and near-reef pelagic environments

We present the first in situ observations of the pelagic larvae of coral-reef fishes feeding, schooling and being preyed upon. In addition, we report on their behavioural interactions with adult and juvenile fishes. Observations on over 500 larvae of over 50 species (mostly from four families) near the end of their pelagic interval were made in both open water (> 1 km offshore) and near-reef environments. Nearly 10% of larvae were seen to feed in open water, but < 1% fed near the reef. Presettlement schooling was observed in five species of four families. We observed no predation upon larvae in open water except near the bottom. Near the reef, 8.5% of larvae were eaten. The main predators near and on the reef were a species of wrasse and lizardfishes. Rates of predation seem to differ among genera of pomacentrids, perhaps related to differences in behaviour when settling. When confronted with adult fishes, which happened largely near the reef, larvae reacted with a limited range of behaviours, including sheltering near the observer, swimming to the surface, slowing or stopping, or swimming offshore. The frequency of these behaviours differed among larvae of three pomacentrid genera. Interactions with reef residents, particularly pomacentrids, were common, and usually involved aggression by the resident toward settling larvae. This may act to discourage settlement during the day when such residents are active. These data show that behaviour of late larvae of coral-reef fishes is complex and can greatly influence survival and recruitment. Further, behaviour differs among taxa, showing that not only are larvae not passive, but also that a generalised behaviour of larvae does not exist.     

Larval development of the Indo-Pacific perciform fish,Centrogenys vaigiensis (Pisces: Centrogeniidae)

Based on seven larvae from northern Australia, development ofCentrogenys vaigiensis—a species of uncertain phylogenetic affinities—is described for the first time. Identification was established from meristic and osteological characters. Development is characterized by few morphological specializations and is apparently completed at a small size (ca 5 mm standard length). Larvae are deep-bodied and compressed, with very limited head spination (small spines on preopercle, subopercle, opercle and supracleithrum). Fin development takes place at about the time of notochord flexion, and is complete at about 4.3 mm, with the exception of anal spine three, which does not fully transform from a soft ray until after settlement. Fin spines are short, smooth and weak. Larvae are apparently limited to near-shore, shallow marine waters, and based on the size of what are apparently settlement-stage larvae, the pelagic period may be short.     

Immunoglobulin G galactosylation and sialylation are associated with pregnancy-induced improvement of rheumatoid arthritis and the postpartum flare: results from a large prospective cohort study

Introduction  

Improvement of rheumatoid arthritis (RA) during pregnancy has been causatively associated with increased galactosylation of immunoglobulin G (IgG) N-glycans. Since previous studies were small, did not include the postpartum flare and did not study sialylation, these issues were addressed in the present study.     

Ontogeny of behaviour in larvae of marine demersal fishes

The development of behaviours that are relevant to larval dispersal of marine, demersal fishes is poorly understood. This review focuses on recent work that attempts to quantify the development of swimming, orientation, vertical distribution and sensory abilities. These behaviours are developed enough to influence dispersal outcomes during most of the pelagic larval stage. Larvae swim in the ocean at speeds similar to the currents found in many locations and at 3–15 body lengths per second (BL s⁻¹), although, based on laboratory measurements, species from cold environments swim slower than those from warm environments. At least in warm-water species, larvae swim in an inertial hydrodynamic environment for most of their pelagic period. Unfed swimming endurance is >10 km from about 8–10 mm, and reaches more than 50 km before settlement in several species. Larval fishes are efficient swimmers. In most species, a large majority of larvae have orientated swimming in the ocean, but the precision of orientation does not improve with growth. Swimming direction of the larvae frequently changes ontogenetically. Vertical distribution changes ontogenetically in most species, and both ontogenetic ascents and descents are found. Development of schooling is poorly understood, but it may influence speed, orientation and vertical distribution. Sensory abilities (hearing, olfaction, vision) form early, are well developed and are able to detect cues relevant to orientation for most of the pelagic larval stage. All this indicates that the passive portion of the pelagic larval duration will be short, at least in most warm-water species, and that behaviour must be taken into account when considering dispersal, and in particular in dispersal models. Although quantitative information on the ontogeny of some behaviours is available for a relatively small number of species, more research in this field is required, especially on species from colder waters.     

Multispectral fingerprinting for improved in vivo cell dynamics analysis

Background  

Tracing cell dynamics in the embryo becomes tremendously difficult when cell trajectories cross in space and time and tissue density obscure individual cell borders. Here, we used the chick neural crest (NC) as a model to test multicolor cell labeling and multispectral confocal imaging strategies to overcome these roadblocks.     

Mechanism of inhibition of retrovirus release from cells by interferon-induced gene ISG15

Budding of retroviruses from cell membranes requires ubiquitination of Gag and recruitment of cellular proteins involved in endosome sorting, including endosome sorting complex required for transport III (ESCRT-III) protein complex and vacuolar protein sorting 4 (VPS4) and its ATPase. In response to infection, a cellular mechanism has evolved that blocks virus replication early and late in the budding process through expression of interferon-stimulated gene 15 (ISG15), a dimer homologue of ubiquitin. Interferon treatment of DF-1 cells blocks avian sarcoma/leukosis virus release, demonstrating that this mechanism is functional under physiological conditions. The late block to release is caused in part by a loss in interaction between VPS4 and its coactivator protein LIP5, which is required to promote the formation of the ESCRT III-VPS4 double-hexamer complex to activate its ATPase. ISG15 is conjugated to two different LIP5-ESCRT-III-binding charged multivesicular body proteins, CHMP2A and CHMP5. Upon ISGylation of each, interaction with LIP5 is no longer detected. Two other ESCRT-III proteins, CHMP4B and CHMP6, are also conjugated to ISG15. ISGylation of CHMP2A, CHMP4B, and CHMP6 weakens their binding directly to VPS4, thereby facilitating the release of this protein from the membrane into the cytosol. The remaining budding complex fails to release particles from the cell membrane. Introducing a mutant of ISG15 into cells that cannot be conjugated to proteins prevents the ISG15-dependent mechanism from blocking virus release. CHMP5 is the primary switch to initiate the antiviral mechanism, because removal of CHMP5 from cells prevents ISGylation of CHMP2A and CHMP6.     

Comparing genomic prediction accuracy from purebred,crossbred and combined purebred and crossbred reference populations in sheep

Background

The accuracy of genomic prediction depends largely on the number of animals with phenotypes and genotypes. In some industries, such as sheep and beef cattle, data are often available from a mixture of breeds, multiple strains within a breed or from crossbred animals. The objective of this study was to compare the accuracy of genomic prediction for several economically important traits in sheep when using data from purebreds, crossbreds or a combination of those in a reference population.

Methods

The reference populations were purebred Merinos, crossbreds of Border Leicester (BL), Poll Dorset (PD) or White Suffolk (WS) with Merinos and combinations of purebred and crossbred animals. Genomic breeding values (GBV) were calculated based on genomic best linear unbiased prediction (GBLUP), using a genomic relationship matrix calculated based on 48 599 Ovine SNP (single nucleotide polymorphisms) genotypes. The accuracy of GBV was assessed in a group of purebred industry sires based on the correlation coefficient between GBV and accurate estimated breeding values based on progeny records.

Results

The accuracy of GBV for Merino sires increased with a larger purebred Merino reference population, but decreased when a large purebred Merino reference population was augmented with records from crossbred animals. The GBV accuracy for BL, PD and WS breeds based on crossbred data was the same or tended to decrease when more purebred Merinos were added to the crossbred reference population. The prediction accuracy for a particular breed was close to zero when the reference population did not contain any haplotypes of the target breed, except for some low accuracies that were obtained when predicting PD from WS and vice versa.

Conclusions

This study demonstrates that crossbred animals can be used for genomic prediction of purebred animals using 50 k SNP marker density and GBLUP, but crossbred data provided lower accuracy than purebred data. Including data from distant breeds in a reference population had a neutral to slightly negative effect on the accuracy of genomic prediction. Accounting for differences in marker allele frequencies between breeds had only a small effect on the accuracy of genomic prediction from crossbred or combined crossbred and purebred reference populations.