A Pig Model of the Human Gastro-intestinal Tract

As part of a mini-symposium highlighting collaborative research opportunities with the Tufts Cummings School of Veterinary Medicine, this presentation discusses the development of a clinically relevant pig model of the human gastro-intestinal tract for studying Clostridium difficile infection and human adult and infant fecal microbiome

A comparison of the Giardia lamblia trophozoite and cyst transcriptome using microarrays

<p>Abstract</p> <p>Background</p> <p>Compared with many protists, <it>Giardia lamblia </it>has a simple life cycle alternating between cyst and trophozoite. Most research on the molecular biology of <it>Giardia </it>parasites has focused on trophozoites and the processes of excystation and encystation, whereas cysts have attracted less interest. The striking morphological differences between the dormant cyst and the rapidly dividing and motile trophozoite implies profound changes in the metabolism as the parasite encysts in the host's intestine and excysts upon ingestion by a new host.</p> <p>Results</p> <p>To investigate the magnitude of the transcriptional changes occurring during the <it>G. lamblia </it>life cycle we compared the transcriptome of <it>G. lamblia </it>trophozoites and cysts using single-color oligonucleotide microarrays. Cysts were found to possess a much smaller transcriptome, both in terms of mRNA diversity and abundance. Genes encoding proteins related to ribosomal functions are highly over-represented. The comparison of the transcriptome of cysts generated in culture or extracted from feces revealed little overlap, raising the possibility of significant biological differences between the two types of cysts.</p> <p>Conclusions</p> <p>The comparison of the <it>G. lamblia </it>cyst and trophozoite transcriptome showed that transcripts of most genes are present at a lower level in cysts. This global view of the cyst and trophozoite transcriptome complements studies focused on the expression of selected genes during trophozoite multiplication, encystation and excystation.</p

Polymorphism of postmating reproductive isolation within plant species

Speciation can be viewed as the evolution of reproductive isolation between formerly interbreeding populations. Recent years have seen great advances in our understanding of the genetic mechanisms underlying postmating reproductive isolation during plant speciation. Nevertheless, little is known about the early stages of species divergence and the evolution of reproductive isolation at the within species level. Direct or indirect evidence indicates that intrinsic postzygotic mechanisms are prevalent and often polymorphic among allopatric conspecific populations of plants. We review studies that report direct or indirect evidence for polymorphism of genic (i.e., gene-based) postmating reproductive isolation within species' ranges. Specifically, we focus on three genic mechanisms often held responsible for reproductive isolation between species: Bateson-Dobzhansky-Muller (BDM) incompatibilities and two widespread types of genomic conflict, transmission ratio distortion and cytonuclear interactions. We further highlight the close similarity between reported cases of outbreeding depression among conspecific populations, especially those that correspond to the intrinsic co-adaptation model, and the origin of genetic incompatibilities. This association holds great promise to help improve our understanding of the processes involved in the initial stage of speciation, and it highlights the close (and often overlooked) relationship between evolutionary and conservation biology

Protein Coding Gene Nucleotide Substitution Pattern in the Apicomplexan Protozoa Cryptosporidium parvum and Cryptosporidium hominis

Cryptosporidium parvum and C. hominis are related protozoan pathogens which infect the intestinal epithelium of humans and other vertebrates. To explore the evolution of these parasites, and identify genes under positive selection, we performed a pairwise whole-genome comparison between all orthologous protein coding genes in C. parvum and C. hominis. Genome-wide calculation of the ratio of nonsynonymous versus synonymous nucleotide substitutions (dN/dS) was performed to detect the impact of positive and purifying selection. Of 2465 pairs of orthologous genes, a total of 27 (1.1%) showed a high ratio of nonsynonymous substitutions, consistent with positive selection. A majority of these genes were annotated as hypothetical proteins. In addition, proteins with transmembrane and signal peptide domains are significantly more frequent in the high dN/dS group

Drug concentration prediction and delivery

In medical practice, the decision-making process regarding drug dose is critical to patients’ health and recovery. For drugs with narrow therapeutic ranges, the medical doctor decides the quantity (dose amount) and frequency (dose interval) on the basis of a set of patients’ parameters. Computer-aided tools for drug dose administration makes the prescription procedure faster, more accurate, more objective, and less expensive. We describe an advanced integrated Drug Administration Decision Support System (DADSS) to help clinicians/patients with the dose/frequency computing. Based on a support vector machine (SVM) algorithm, enhanced with the random sample consensus technique, this system is able to predict the drug concentration values and computes the ideal dose amount and dose interval for a new patient. With an extension to combine the SVM method and the explicit analytical model, the advanced integrated DADSS system is able to compute drug concentration-to-time curves for a patient under different conditions

Generations, intergenerational relationships, generational policy:A multilingual compendium

Generationenbeziehungen gewinnen in gegenwärtigen Gesellschaften in allen Lebensbereichen an Bedeutung. Wenn wir uns mit diesen Beziehungen in der Forschung, der Lehre, der Praxis und der Politik beschäftigen, brauchen wir tragfähige Schlüsselkonzepte. Das ist insbesondere der Fall, wenn Texte in verschiedenen Kulturen und Sprachen verwendet und übersetzt werden. Das ist der Ausgangspunkt einer mehrsprachigen Publikation verfasst vom internationalen Netzwerk GENERATIONES. Mit diesem Kompendium schlagen wir eine synchronisierte und differenzierte Terminologie in fünf Sprachen vor: Deutsch, English, Französisch, Spanisch und Italienisch

Comparative genome analysis of two Cryptosporidium parvum isolates with different host range

Parasites of the genus Cryptosporidium infect the intestinal and gastric epithelium of different vertebrate species. Some of the many Cryptosporidium species described to date differ with respect to host range; whereas some species’ host range appears to be narrow, others have been isolated from taxonomically unrelated vertebrates. To begin to investigate the genetic basis of Cryptosporidium host specificity, the genome of a C. parvum isolate belonging to a sub-specific group found exclusively in humans was sequenced and compared to the reference C. parvum genome representative of the zoonotic group. Over 12,000 single-nucleotide polymorphisms (SNPs), or 1.4 SNP per kilobase, were identified. The genome distribution of SNPs was highly heterogeneous, but non-synonymous and silent SNPs were similarly distributed. On many chromosomes, the most highly divergent regions were located near the ends. Genes in the most diverged regions were almost twice as large as the genome-wide average. Transporters, and ABC transporters in particular, were over-represented among these genes, as were proteins with predicted signal peptide. Possibly reflecting the presence of regulatory sequences, the distribution of intergenic SNPs differed according to the function of the downstream open reading frame. A 3-way comparison of the newly sequenced anthroponotic C. parvum, the reference zoonotic C. parvum and the human parasite C. hominis identified genetic loci where the anthroponotic C. parvum sequence is more similar to C. hominis than to the zoonotic C. parvum reference. Because C. hominis and anthroponotic C. parvum share a similar host range, this unexpected observation suggests that proteins encoded by these genes may influence the host range

Caracterização molecular de Cryptosporidium em bezerros de assentamentos rurais da região Noroeste do estado de São Paulo, Brasil

The study was conducted on 25 properties of the settlements Sao Jose I and Salvador, located in the municipalities of Brejo Alegre and Birigui, in the State of Sao Paulo, Brazil. A record of variables was elaborated and included data such as gender, breed and age of the animals. A total of 231 stool samples were collected from bovines aged one to six months, 128 being females and 103 males, 131 crossbred and 100 Holstein. Among the 231 samples, 17 (7.36%) were positive for Crvptosporidium spp. both by malachite green negative staining and by nested-PCR. Of the 17 positive samples, 14 were sequenced in agarose gel. These sequences were detected between 99% and 100% of genetic similarity for the following species. One sequence was similar to C. parvum (AB513880.1), one to C. bovis (MF074602.1), two to C. ryanae (KT922233.1), one to C. felis (KM977642.1) and nine were similar for C. andersoni reference MF350628. C. andersoni was found in animals aged 2-6 months, an age group which is different from those described by several authors. The presence of C. parvum indicates that the calves in the studied region should be considered a potential source for zoonotic transmission. For the first time to our knowledge, C. felis was identified in cattle in America401491496FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2012/13733-3O estudo foi realizado num total de 25 propriedades localizadas nos assentamentos São José I e Salvador, situados nos municípios de Brejo Alegre e Birigui, no estado de São Paulo. Um registro de variáveis foi elaborado, incluindo dados como sexo, raça e idade dos animais. Foram colhidas 231 amostras de fezes de bovinos de um a seis meses de idade, sendo 128 fêmeas e 103 machos, 131 mestiços e 100 da raça Holandesa. Entre os 231 bovinos examinados, 17 (7,36%) foram positivos para Cryptosporidium spp. tanto pela coloração negativa de verde malaquita como pela nested-PCR. Das 17 amostras positivas, 14 apresentaram amplificação pela eletroforese em gel de agarose suficiente para fazer o sequenciamento de DNA. Essas sequências foram detectadas similaridade genética entre 99% e 100% com as seguintes espécies. Uma sequência foi semelhante com C. parvum (referência: AB513880.1), uma com C. bovis(MF074602.1), duas com C. ryanae (KT922233.1), uma com C. felis (KM977642.1) e nove foram semelhantes com C. andersoni (MF350628). O estudo caracteriza a presença do Cryptosporidiumspp. em bovinos oriundos de propriedades produtoras de leite na região Noroeste do estado de São Paulo, sendo o C. andersoni a espécie mais prevalente nesses animais, principalmente em uma faixa etária diferente das descritas por diversos autores. A presença de C. parvum indica que os bezerros da região estudada devem ser considerados como uma fonte potencial de oocistos de espécies zoonóticas.Identificamos com ineditismo o C. felis em bovinos na América, o que corrobora outros estudos realizados na Polônia e Espanha e evidencia a presença de espécies de Cryptosporidium em fezes em hospedeiros não naturais. Palavras-chave: Bezerros. Caracterização molecular. Criptosporidiose. Nested-PCR.Protozoan of the genus Cryptosporidium are obligate intracellular coccidia with a cosmopolitan distribution. Biological data and various molecular genotyping tools indicate that the genus Cryptosporidium comprises about 30 valid species and more than 70 genotypes that can infect fishes, amphibians, reptiles, birds, and mammals (NAKAMURA; MEIRELES, 2015).Among the named species, 13 have been described in cattle. Of these, nine present zoonotic potential, being more prevalent in humans: Cryptosporidium hominis, Cryptosporidium parvum, Cryptosporidium meleagridis, Cryptosporidium cuniculus and, occasionally,Cryptosporidium muris, Cryptosporidium suis, Cryptosporidium ubiquitum, Cryptosporidium felis(BORNAY-LLINARES et al. 1999; CARDONA et al., 2015) and Cryptosporidium canis (KVÁČ et al., 2016).Cattle are mainly infected with C. parvum, Cryptosporidium bovis, Cryptosporidium ryanaeand Cryptosporidium andersoni (XIAO, 2010). Of these, only the first is of zoonotic importance, being a concern for public health, since human cryptosporidiosis can be acquired from infected calves (LEARMONTH et al., 2004; SOPWITH et al., 2005; DEL COCO et al., 2014). These four species of Cryptosporidium are frequently diagnosed in cattle of different ages. Among these, C. parvumis the most prevalent in young pre-weaning calves (less than two months old) and shows low host specificity, and some genotypes are considered to have high zoonotic potential (DIXON et al., 2011).During the post-weaning phase (three to 11 months of age) a reduction in the prevalence of C. parvum is observed, however, in this stage an increase of C. bovis and C. ryanae infections is noticed. The latter two species are not considered zoonotic and show high specificity for bovine. C. andersoni is the species that mainly infects post-weaned calves and adult cattle. These parasitic species can infect other ruminants and rarely humans (DIXON et al., 2011).Due to the ability of this protozoan to infect different hosts and its constant presence in the environment, humans can acquire the infection in several ways, such as through ingestion of food and water contaminated with oocysts, direct contact with infected people (anthroponotic) or animals (zoonotic). Increases in environmental contamination and infected reservoirs assist in zoonotic transmission, as human cryptosporidiosis is also caused by certain species that also affect ruminants. The contact of humans with the feces of these animals that contains oocysts or contaminated water constitutes routes of transmission to humans (DEL COCO et al., 2014

Generations, intergenerational relationships, generational policy: a multilingual compendium (edition 2014/15)

The members of the International Network for the Analysis of Intergenerational Relations (Generationes) proudly present the most recent issue of the jointly produced compendium “Generations, Intergenerational Relations and Generational Policy”. This new version includes seven languages (English, French, German, Italian, Spanish, Polish (New) and Portuguese (New)). Its layout is designed for using it to translate the specific concepts and terminology of research into generations and intergenerational relations from one language into another