Characterization of Stem-Like Cells in Mucoepidermoid Tracheal Paediatric Tumor

Stem cells contribute to regeneration of tissues and organs. Cells with stem cell-like properties have been identified in tumors from a variety of origins, but to our knowledge there are yet no reports on tumor-related stem cells in the human upper respiratory tract. In the present study, we show that a tracheal mucoepidermoid tumor biopsy obtained from a 6 year-old patient contained a subpopulation of cells with morphology, clonogenicity and surface markers that overlapped with bone marrow mesenchymal stromal cells (BM-MSCs). These cells, designated as MEi (mesenchymal stem cell-like mucoepidermoid tumor) cells, could be differentiated towards mesenchymal lineages both with and without induction, and formed spheroids in vitro. The MEi cells shared several multipotent characteristics with BM-MSCs. However, they displayed differences to BM-MSCs in growth kinectics and gene expression profiles relating to cancer pathways and tube development. Despite this, the MEi cells did not possess in vivo tumor-initiating capacity, as proven by the absence of growth in situ after localized injection in immunocompromised mice. Our results provide an initial characterization of benign tracheal cancer-derived niche cells. We believe that this report could be of importance to further understand tracheal cancer initiation and progression as well as therapeutic development

Self-Mating in the Definitive Host Potentiates Clonal Outbreaks of the Apicomplexan Parasites Sarcocystis neurona and Toxoplasma gondii

Tissue-encysting coccidia, including Toxoplasma gondii and Sarcocystis neurona, are heterogamous parasites with sexual and asexual life stages in definitive and intermediate hosts, respectively. During its sexual life stage, T. gondii reproduces either by genetic out-crossing or via clonal amplification of a single strain through self-mating. Out-crossing has been experimentally verified as a potent mechanism capable of producing offspring possessing a range of adaptive and virulence potentials. In contrast, selfing and other life history traits, such as asexual expansion of tissue-cysts by oral transmission among intermediate hosts, have been proposed to explain the genetic basis for the clonal population structure of T. gondii. In this study, we investigated the contributing roles self-mating and sexual recombination play in nature to maintain clonal population structures and produce or expand parasite clones capable of causing disease epidemics for two tissue encysting parasites. We applied high-resolution genotyping against strains isolated from a T. gondii waterborne outbreak that caused symptomatic disease in 155 immune-competent people in Brazil and a S. neurona outbreak that resulted in a mass mortality event in Southern sea otters. In both cases, a single, genetically distinct clone was found infecting outbreak-exposed individuals. Furthermore, the T. gondii outbreak clone was one of several apparently recombinant progeny recovered from the local environment. Since oocysts or sporocysts were the infectious form implicated in each outbreak, the expansion of the epidemic clone can be explained by self-mating. The results also show that out-crossing preceded selfing to produce the virulent T. gondii clone. For the tissue encysting coccidia, self-mating exists as a key adaptation potentiating the epidemic expansion and transmission of newly emerged parasite clones that can profoundly shape parasite population genetic structures or cause devastating disease outbreaks

Population-level deficit of homozygosity unveils CPSF3 as an intellectual disability syndrome gene.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadPredicting the pathogenicity of biallelic missense variants can be challenging. Here, we use a deficit of observed homozygous carriers of missense variants, versus an expected number in a set of 153,054 chip-genotyped Icelanders, to identify potentially pathogenic genotypes. We follow three missense variants with a complete deficit of homozygosity and find that their pathogenic effect in homozygous state ranges from severe childhood disease to early embryonic lethality. One of these variants is in CPSF3, a gene not previously linked to disease. From a set of clinically sequenced Icelanders, and by sequencing archival samples targeted through the Icelandic genealogy, we find four homozygous carriers. Additionally, we find two homozygous carriers of Mexican descent of another missense variant in CPSF3. All six homozygous carriers of missense variants in CPSF3 show severe intellectual disability, seizures, microcephaly, and abnormal muscle tone. Here, we show how the absence of certain homozygous genotypes from a large population set can elucidate causes of previously unexplained recessive diseases and early miscarriage.Sacchi Foundatio

Seven New species of \u3ci\u3eEimeria\u3c/i\u3e Schneider, 1875 (Apicomplexa: Eimeriidae) from Colubrid Snakes of Guatemala and a Discussion of What to Call Ellipsoid Tetrasporocystic, Dizoic Coccidia of Reptiles

During a survey of Guatemalan herpetofauna in the summers of 1998–2000, 29 presumed new species of Eimeria Schneider, 1875 were found, seven of which have a distinct elongate-ellipsoidal shape (L/W ratio ≥ 1.7) and are described herein. Six of the seven new species are similar in oöcyst length, width and L/W ratio and sporocyst length, width and L/W ratio, lack a micropyle, oöcyst residuum, Stieda body, sub- and parastieda bodies, have a polar granule and sporocyst residuum, and their sporocysts appear to have dehiscence sutures. The seventh is slightly smaller and has sporocysts with a Stieda body. The new species are: E. coniophanes n. sp – whose sporulated oöcysts from Coniophanes fissidens are 29.2 × 14.9 (27-31 × 13-16) μm, with sporocysts 10.0 × 7.8 μm; E. coniophis n. sp. – from Conophis lineatus are 32.0 × 16.5 (30-34 × 14-18) μm, with sporocysts 10.2 × 8.9 μm; E. dryomarchoni n. sp. – from Drymarchon corais are 32.2 × 17.7 (31-34 × 17-19) μm, with sporocysts 10.7 × 8.6 μm; E. leptophis n. sp. – from Leptophis mexicanus are 29.5 × 17.0 (28-31 × 16-18) μm, with sporocysts 10.0 × 9.1 μm; E. oxybelis n. sp. – from Oxybelis aeneus are 31.8 × 16.5 (29-33 × 15-18) μm, with sporocysts 10.3 × 8.8 μm; and E. scaphiodontophis n. sp. – from Scaphiodontophis annulatus are 30.0 × 15.3 (28-33 × 14-16) μm, with sporocysts 9.9 × 7.9 μm. Sporulated oöcysts of E. siboni n. sp. from Sibon nebulata are 24.3 × 14.2 (21-27 × 13-16) μm, with sporocysts 10.0 × 7.1 μm and with a Stieda body. We conclude that until all aspects of each life-cycle are known, it is prudent at this time to name all tetrasporocystic dizoic coccidia from snakes as members of Eimeria rather than place some of them in Choleoeimeria Paperna & Landsberg, 1989

Determination of NO adsorption sites on Pd(100) using core level photoemission and low energy electron diffraction

The adsorption of NO on Pd(1 0 0) is investigated with high resolution core level spectroscopy and low energy electron diffraction (LEED). Several ordered NO overlayers were observed, in agreement with earlier Studies. Our data clearly show that NO adsorbs in fourfold hollow sites at coverages tip to 0.25 -0.30 monolayer (ML) whereas at 0.5 ML only bridge sites are occupied. By a reinterpretation of previous electron energy loss spectroscopy (EELS) investigations we show that the new site assignments are in agreement the EELS data, Based on the photoemission results for the N 1s and the Pd 3d core levels we propose new structure models for the (2root2 x 2root2)R45degrees and the p(4 x 2) LEED patterns found at coverages of 0.5 and 0.25 ML, respectively. In the latter case, it is suggested that the p(4 x 2) LEED pattern is formed from domains having p(2 x 2)-NO and c(4 x 2)-2NO unit cells

Icelandic families with autosomal dominant polycystic kidney disease: families unlinked to chromosome 16p13.3 revealed by linkage analysis

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldWe have mainly used 3 highly polymorphic DNA markers, 3'HVR (D16S85), 16AC2.5 (D16S291) and SM7 (D16S283), flanking the PKD1 region on chromosome 16p13.3 to establish linkage status in seven Icelandic families with autosomal dominant polycystic kidney disease (ADPKD). In four families, the disease locus is in the PKD1 region, and three families are "unlinked" to chromosome 16p13.3. In one of the "unlinked" families, the disease locus is excluded from a part of the long arm of chromosome 2, and we support a theory of more than 2 loci being responsible for ADPKD. Our data confirm the location of the locus YNH24 (D2S44) to chromosome 2q13-q24