Fetal Microchimeric Cells in Blood of Women with an Autoimmune Thyroid Disease

CONTEXT: Hashimoto's thyroiditis (HT) and Graves' disease (GD), two autoimmune thyroid diseases (AITD), occur more frequently in women than in men and show an increased incidence in the years following parturition. Persisting fetal cells could play a role in the development of these diseases. OBJECTIVE: Aim of this study was to detect and characterize fetal cells in blood of postpartum women with and without an AITD. PARTICIPANTS: Eleven patients with an AITD and ten healthy volunteers, all given birth to a son maximum 5 years before analysis, and three women who never had been pregnant, were included. None of them had any other disease of the thyroid which could interfere with the results obtained. METHODS: Fluorescence in situ hybridization (FISH) and repeated FISH were used to count the number of male fetal cells. Furthermore, the fetal cells were further characterized. RESULTS: In patients with HT, 7 to 11 fetal cells per 1.000.000 maternal cells were detected, compared to 14 to 29 fetal cells in patients with GD (p=0.0061). In patients with HT, mainly fetal CD8(+) T cells were found, while in patients with GD, fetal B and CD4(+) T cells were detected. In healthy volunteers with son, 0 to 5 fetal cells were observed, which was significantly less than the number observed in patients (p<0,05). In women who never had been pregnant, no male cells were detected. CONCLUSION: This study shows a clear association between fetal microchimeric cells and autoimmune thyroid diseases

The effects of multiple features of alternatively spliced exons on the K(A)/K(S )ratio test

BACKGROUND: The evolution of alternatively spliced exons (ASEs) is of primary interest because these exons are suggested to be a major source of functional diversity of proteins. Many exon features have been suggested to affect the evolution of ASEs. However, previous studies have relied on the K(A)/K(S )ratio test without taking into consideration information sufficiency (i.e., exon length > 75 bp, cross-species divergence > 5%) of the studied exons, leading to potentially biased interpretations. Furthermore, which exon feature dominates the results of the K(A)/K(S )ratio test and whether multiple exon features have additive effects have remained unexplored. RESULTS: In this study, we collect two different datasets for analysis – the ASE dataset (which includes lineage-specific ASEs and conserved ASEs) and the ACE dataset (which includes only conserved ASEs). We first show that information sufficiency can significantly affect the interpretation of relationship between exons features and the K(A)/K(S )ratio test results. After discarding exons with insufficient information, we use a Boolean method to analyze the relationship between test results and four exon features (namely length, protein domain overlapping, inclusion level, and exonic splicing enhancer (ESE) frequency) for the ASE dataset. We demonstrate that length and protein domain overlapping are dominant factors, and they have similar impacts on test results of ASEs. In addition, despite the weak impacts of inclusion level and ESE motif frequency when considered individually, combination of these two factors still have minor additive effects on test results. However, the ACE dataset shows a slightly different result in that inclusion level has a marginally significant effect on test results. Lineage-specific ASEs may have contributed to the difference. Overall, in both ASEs and ACEs, protein domain overlapping is the most dominant exon feature while ESE frequency is the weakest one in affecting test results. CONCLUSION: The proposed method can easily find additive effects of individual or multiple factors on the K(A)/K(S )ratio test results of exons. Therefore, the system can analyze complex conditions in evolution where multiple features are involved. More factors can also be added into the system to extend the scope of evolutionary analysis of exons. In addition, our method may be useful when orthologous exons can not be found for the K(A)/K(S )ratio test

Examining the effects of social media in co-located classrooms: A case study based on SpeakUp

The broad availability of mobile computing devices has prompted the apparition of social media applications that support teaching and learning. However, so far, there is conflicting evidence as to whether the benefits such applications provide in terms of engagement and interaction, outweigh their potential cost as a source of distraction. To help in clarifying these issues, the present paper presents a case study on the impact of using SpeakUp (an app aimed at promoting student participation through anonymous chatrooms) in an authentic face-to-face learning scenario. Concretely, we focus on the connection between SpeakUp and the student engagement, distraction, social interaction, and the influence of the teachers' style. Our findings highlight that SpeakUp favored students' engagement and social interaction, but they also point towards its limitations in keeping students communicating about content relevant to the course

Comparative Genomics of the Apicomplexan Parasites Toxoplasma gondii and Neospora caninum: Coccidia Differing in Host Range and Transmission Strategy

Toxoplasma gondii is a zoonotic protozoan parasite which infects nearly one third of the human population and is found in an extraordinary range of vertebrate hosts. Its epidemiology depends heavily on horizontal transmission, especially between rodents and its definitive host, the cat. Neospora caninum is a recently discovered close relative of Toxoplasma, whose definitive host is the dog. Both species are tissue-dwelling Coccidia and members of the phylum Apicomplexa; they share many common features, but Neospora neither infects humans nor shares the same wide host range as Toxoplasma, rather it shows a striking preference for highly efficient vertical transmission in cattle. These species therefore provide a remarkable opportunity to investigate mechanisms of host restriction, transmission strategies, virulence and zoonotic potential. We sequenced the genome of N. caninum and transcriptomes of the invasive stage of both species, undertaking an extensive comparative genomics and transcriptomics analysis. We estimate that these organisms diverged from their common ancestor around 28 million years ago and find that both genomes and gene expression are remarkably conserved. However, in N. caninum we identified an unexpected expansion of surface antigen gene families and the divergence of secreted virulence factors, including rhoptry kinases. Specifically we show that the rhoptry kinase ROP18 is pseudogenised in N. caninum and that, as a possible consequence, Neospora is unable to phosphorylate host immunity-related GTPases, as Toxoplasma does. This defense strategy is thought to be key to virulence in Toxoplasma. We conclude that the ecological niches occupied by these species are influenced by a relatively small number of gene products which operate at the host-parasite interface and that the dominance of vertical transmission in N. caninum may be associated with the evolution of reduced virulence in this species

Polymorphism in the lipase genes of Geotrichum candidum strains

The fungus Geotrichum candidum produces extracellular lipases. Purification and characterization of different lipase isoforms from various G. candidum strains is difficult due to the close physical and biochemical properties of the isoforms. Consequently, the characterization of these enzymes and their substrate specificites has been difficult. We have determined the lipase genes present in four strains of G. candidum (ATCC 34614, NRCC 205002, NRRL Y-552 and NRRL Y-553) by molecular cloning and DNA sequencing. Each strain contains two genes similar to the previously identified lipase I and lipase II cDNAs. Our data suggest that no other related lipase genes are present in these strains. Each lipase-gene family shows sequence variation (polymorphism) that is confirmed by Southern-blot analysis. This polymorphism and the sequence differences between lipase I and lipase II have been localized within the previously determined three-dimensional structure of lipase II. Although most of the amino acid substitutions are located on the protein surface, some are present in structural features possibly involved in determining substrate specificity.NRC publication: Ye