Plus de 20 % des cancers sont dus à une infection virale, bactérienne ou parasitaire. En effet, le parasite Cryptosporidium parvum (C. parvum) qui est capable d’induire, chez des souris immunodéprimées, le développement d'adénocarcinomes invasifs au niveau gastro-intestinal. Cependant, la compréhension de la pathogénicité de Cryptosporidium a été limitée par l'absence d'un système de culture en continu et à long terme. Il est donc indispensable d’améliorer les systèmes de culture in vitro en mimant le plus possible les conditions de l’in vivo. J’ai participé tout d’abord à la réalisation d’une étude épidémiologique sur des patients Libanais atteints ou non de néoplasies/adénocarcinomes digestifs. Le taux d’infection à Cryptosporidium était significativement plus élevé chez les patients atteints de cancers coliques comparativement aux autres groupes de patients. Offrant ainsi de nouveaux arguments en faveur d’un lien entre l’infection à Cryptosporidium et la pathologie cancéreuse chez l’homme. Ensuite, j’ai développé un modèle de culture tridimensionnelle (3D) à partir d’un côlon murin adulte. Ce système a permis le maintien de l’infection pendant 35 jours et il a mis en évidence le développement in vitro de lésions néoplasiques 27 jours post infection. Il s’agit, de la première description d'une induction de néoplasies intraépithéliales de bas grade dans un système de culture 3D, par un parasite. Afin d’automatiser ce système, j’y ai associé un dispositif de microfluidique. Ce dernier a permis le maintien de la culture pendant 8 jours. Il s’agit de la première description d'une culture tissulaire d’intestin sur un dispositif microfluidique viable pour 8 jours. / Almost 20% of cancers are due to a viral, bacterial or parasitic infection. For instance, Cryptosporidium parvum (C. parvum) was found to induce the development of an invasive digestive adenocarcinomas in an experimental model of SCID mice.However, the understanding of the pathogenesis of Cryptosporidium has been limited by the lack of a long-term culture system. It is therefore essential to improve the in vitro culture systems by trying to mimic the in vivo conditions. Firstly, the association between Cryptosporidium infection and cancer development was investigated through an epidemiological study among cohorts of Lebanese patients with or without recent diagnosis of digestive cancer before any treatment. A high rate of Cryptosporidium was detected in biopsies from Lebanese patients with digestive neoplasia/adenocarcinoma. These results showed that Cryptosporidium is associated with human colon cancer being maybe a potential etiological agent of this disease. In the second part, a three dimensional (3D) Cryptosporidium culture model was developed from adult murine colon. This system allowed the reproduction of neoplasic lesions at 27 days post-infection, providing new evidence of the role of the parasite in the induction of carcinogenesis. This is the first description of a low-grade intraepithelial neoplasia induction after parasite infection in a 3D culture. Finally, in order to automatize the culture, a microfluidics device for explant culture was designed. An explant culture was maintained for almost 8 days using this microfluidic device. To our knowledge, this is the first description of a gut tissue culture on a microfluidic device that was viable for 8 days.

Uterine inflammation is one of the causes of a poor uterine environment. This can result in early embryonic loss in the mare due to an inhibition of or an increased secretion of prostaglandin F2α (PGF2α ). Oxytocin binds to endometrial cell receptors to activate prostaglandin synthesis. Increased secretion or accumulation of PGF2α within the uterus due to uterine inflammation can cause luteolysis and result in early embryonic loss. Supplementation with polyunsaturated fatty acids (PUFAs) has been shown to influence prostaglandin production in many species, although the effects on the mare remain unknown. Equine endometrial biopsies were collected and used to establish endometrial epithelial cell and explant cultures to determine the release of PGF2α and PGFM in response to oxytocin stimulation. Endometrial explant cultures were used to determine the inhibitory effects of Atosiban, an oxytocin receptor antagonist, and Indomethacin, a cyclooxygenase –2 inhibitor, on PGF2α secretion. Endometrial explant cultures were challenged with oxytocin (250 nM) and PGF2α concentrations were measured over time. The effects of PUFAs on equine endometrial prostaglandin production were determined using endometrial biopsies harvested on day two of behavioral estrus. Equine endometrial cells were established and shown to replicate in culture and on a basement membrane matrix. Equine endometrial explants stimulated with oxytocin had increased secretion of PGF2α and PGE2 and the secretion of PGF2α was inhibited through an oxytocin receptor antagonist and Cox inhibition. Endometrial explants stimulated with lipopolysaccharide had increased secretion of PGF2α and PGE2, however oxytocin stimulated to a greater extent than LPS. Supplementation with PUFAs, specifically DHA, decreased the secretion of PGF2α and PGE2, however AA and EPA failed to influence this response. Expression of mRNA was not influenced by fatty acid supplementation, however was altered by stimulus. Therefore DHA influences the inflammatory response in vitro through mechanisms other than enzyme expression. Decreased PGF2α production associated with PUFA supplementation in vivo, creates a likely approach for decreasing early embryonic loss associated with post breeding inflammation commonly seen in the equine industry.

Affecting tissue cultures with precursors is one of methods that increases the production of secondary metabolites in vitro. This thesis deals with precursors affecting production of mescaline in suspension tissue cultures of Trichocereus pachanoi. As precursors dopamine, D, L-tyrosine, casein hydrolysate and shikimic acid were used. Three concentrations of these precursors were prepared. Suspension cultures with different concentrations of precursors were analysed by HPLC method after 48 and 168 hours. Murashige and Skoog medium was used for cultivation. Mescaline biosynthesis was most affected by dopamine. The largest amount of mescaline was produced in suspension culture with the highest concentration of dopamine 50 mg/100 ml.The culture was cultivated for 168 hours. Suspension cultures that were cultivated for 48 hours produced the highest amount of mescaline with the highest concentration of dopamin 50 mg/100 ml. The biosynthesis of mescaline was inhibited by other precursores (D, L-tyrosine, casein hydrolysate, shikimic acid).

The objective was to compare the effects of three corticosteroids at various equimolar concentrations on equine articular explant co-cultures in an inflammatory environment. Synovial and osteochondral explant co-cultures from 6 equine cadavers were exposed to IL-1β (10 ng/mL) and various concentrations (10-4, 10-7, or 10-10 M) of MPA, TA, IPA. Concentrations of PGE2, MMP-13, LDH, and GAG in media were determined at 48 and 96 hours. Results indicated wells with low concentrations of MPA (10-7 and 10-10 M at 48 and 96 hours), TA (10-7 M at 48 hours and 10-7 and 10-10 M at 48 and 96 hours), and IPA (10-10 M at 48 hours) had significantly less PGE2 than positive control samples. Groups with low concentrations (10-7 and 10-10 M) of MPA and TA had significantly less PGE2 than the highest concentration (10-4 M) at 48 hours. Significantly less MMP-13 was detected for all concentrations of MPA, TA, and IPA at 96 hours. The LDH assay results indicated cytotoxicity only for samples treated with IPA at 10-4 M at 48 and 96 hours. GAG was significantly lower for samples treated with TA 10-7 M at 48 hours and MPA 10-10 M at 96 hours versus positive controls. These findings suggest corticosteroids at low concentrations mitigated the inflammatory and catabolic effects of IL-1β to a greater extent than high concentrations. Effects of IPA and MPA were similar to TA at clinically relevant low equimolar concentrations. / Master of Science / Recent data suggest that isoflupredone acetate is commonly administered intra-articularly for treatment of joint disease (osteoarthritis) in horses. Although much data has been published regarding effects of other corticosteroids on cartilage, to our knowledge there have been no similar studies of the effects of isoflupredone acetate. With increased scrutiny from the general public and more stringent control of medication use by regulatory agencies, determination of information regarding such common intra-articular therapies is imperative. In addition, prior studies have only evaluated the effects of corticosteroids on cartilage, whereas other joint tissues (subchondral bone and synovium) have been shown to be important to the biological responses of joints. Therefore, to more closely simulate the natural joint environment, this study was conducted with a co-culture model incorporating synovial tissue, articular cartilage, and subchondral bone within an inflammatory environment (via stimulation with interleukin-1β). The effects of various concentrations of methylprednisolone acetate, triamcinolone acetonide, and isoflupredone acetate on joint tissues were determined via measurement of selected biomarkers. This study provided the first data regarding biological effects of IPA on joint tissues of horses, and the first comparison of such effects with those of other corticosteroids commonly used intra-articularly for the treatment of joint disease in horses.

Master of Science / Department of Animal Sciences and Industry / Duane L. Davis / Cell isolation method may have effects on the characteristics of the cells isolated from porcine umbilical cords. As stem cells age or approach senescence, it is hypothesized that their properties change. We expect that isolation method and age of cells will have effects on the phenotype of porcine umbilical cord (PUC) cells during in vitro expansion. We investigated the effects of three isolation methods on PUC population doublings, ability to produce colony forming units (CFU), and amount of ganglioside GD2 (GD2) expression over eleven passages. Isolation methods were explant (Exp) in which the Wharton's Jelly was removed from cords, minced and plated, enzyme digest (Dig), and stomacher assisted enzyme digestion (Stom). Cell isolates were analyzed for GD2 expression, CFU, and population doublings at early (3), middle (7), and late (11) passage. The Exp method produced greater (P<0.05) population doublings and more (P<0.05) CFU at passage 7. Explant isolates also were numerically more likely to survive to passage 11 (9/9 isolates vs 5/9 for Dig and 7/9 for Stom). In contrast, the percent cells expressing GD2 was greater (P<0.05) for Stom isolates than Exp isolates at passage 11. There were no trends for increased passage number to decreased population doubling, CFU formation, or percent GD2 positive cells. In summary, our results indicate that the Exp isolation method produced the greatest number of population doublings over 11 passages and there were minimal effects of isolation method on CFU and GD2 expression. Although Exp may be more difficult to scale up to isolate all of the PUCs in a cord, it provided greater in vitro expansion than the enzyme methods in our experiment and may provide the most cells for biotechnological and biomedical applications.

Production of secondary metabolites in the explant cultures of Trichocereus pachanoi (Cactaceae) Lucie Urbanová Diploma thesis Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Pharmacy Key words: Trichocereus pachanoi, the explant cultures, mescaline, secondary metabolites, prodrugs, elicitation, cinnamic acid, sodium cinnamate, tryptophan, ozone, methylene blue The aim of this thesis was the research of effect of selected precursors and elicitors for secondary metabolite production of mescaline in explant cultures Trichocereus pachanoi. Suspension cultures were cultivated on the Murashige and Skoog medium with addition of the growth regulators 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine. To observe changes in production these precursors: cinnamic acid, sodium cinnamate and tryptophan, and these elicitors: ozone and methylene blue, were selected. Precursors were prepared and used in concentrations of 50, 100 and 500 mg·l-1. Ozone was added in two time slots, 5 and 10 seconds. Methylene blue has been used in concentrations of 1, 10 and 100 mg·l-1. Cultivation with added compounds lasted for 24 and 168 hours. The content of mescaline was determined by HPLC analysis. A statistically significant effect on the production of mescaline in vitro culture was proved only with...

The mammary explant culture model has been a major experimental tool for studying hormonal requirements for milk protein gene expression as markers of secretory differentiation. Experiments with mammary explants from pregnant animals from many species have established that insulin, prolactin, and glucocorticoid are the minimal set of hormones required for the induction of maximal milk protein gene expression. However, the extent to which mammary explants mimic the response of the mammary gland in vivo is not clear. Recent studies have used microarray technology to study the transcriptome of mouse lactation cycle. It was demonstrated that the each phase of mouse lactation has a distinct transcriptional profile but making sense of microarray results requires analysis of large amounts of biological information which is increasingly difficult to access as the amount of literature increases. / The first objective is to examine the possibility of combining literature and genomic analysis to elucidate potentially novel hypotheses for further research into lactation biology. The second objective is to evaluate the strengths and limitations of the murine mammary explant culture for the study and understanding of murine lactogenesis. The underlying question to this objective is whether the mouse mammary explant culture is a good model or representation to study mouse lactogenesis. / The exponential increase in publication rate of new articles is limiting access of researchers to relevant literature. This has prompted the use of text mining tools to extract key biological information. Previous studies have reported extensive modification of existing generic text processors to process biological text. However, this requirement for modification had not been examined. We have constructed Muscorian, using MontyLingua, a generic text processor. It uses a two-layered generalizationspecialization paradigm previously proposed where text was generically processed to a suitable intermediate format before domain-specific data extraction techniques are applied at the specialization layer. Evaluation using a corpus and experts indicated 86-90% precision and approximately 30% recall in extracting protein-protein interactions, which was comparable to previous studies using either specialized biological text processing tools or modified existing tools. This study also demonstrated the flexibility of the two-layered generalization-specialization paradigm by using the same generalization layer for two specialized information extraction tasks. / The performance of Muscorian was unexpected since potential errors from a series of text analysis processes is likely to adversely affect the outcome of the entire process. Most biomedical entity relationship extraction tools have used biomedical-specific parts-of-speech (POS) tagger as errors in POS tagging and are likely to affect subsequent semantic analysis of the text, such as shallow parsing. A comparative study between MontyTagger, a generic POS tagger, and MedPost, a tagger trained in biomedical text, was carried out. Our results demonstrated that MontyTagger, Muscorian's POS tagger, has a POS tagging accuracy of 83.1% when tested on biomedical text. Replacing MontyTagger with MedPost did not result in a significant improvement in entity relationship extraction from text; precision of 55.6% from MontyTagger versus 56.8% from MedPost on directional relationships and 86.1% from MontyTagger compared to 81.8% from MedPost on un-directional relationships. This is unexpected as the potential for poor POS tagging by MontyTagger is likely to affect the outcome of the information extraction. An analysis of POS tagging errors demonstrated that 78.5% of tagging errors are being compensated by shallow parsing. Thus, despite 83.1% tagging accuracy, MontyTagger has a functional tagging accuracy of 94.6%. This suggests that POS tagging error does not adversely affect the information extraction task if the errors were resolved in shallow parsing through alternative POS tag use. / Microarrays had been used to examine the transcriptome of mouse lactation and a simple method for microarray analysis is correlation studies where functionally related genes exhibit similar expression profiles. However, there has been no study to date using text mining to sieve microarray analysis to generate new hypotheses for further research in the field of lactational biology. Our results demonstrated that a previously reported protein name co-occurrence method (5-mention PubGene) which was not based on a hypothesis testing framework, is generally more stringent than the 99th percentile of Poisson distribution-based method of calculating co-occurrence. It agrees with previous methods using natural language processing to extract protein-protein interaction from text as more than 96% of the interactions found by natural language processing methods coincide with the results from 5-mention PubGene method. However, less than 2% of the gene co-expressions analyzed by microarray were found from direct co-occurrence or interaction information extraction from the literature. At the same time, combining microarray and literature analyses, we derive a novel set of 7 potential functional protein-protein interactions that had not been previously described in the literature. We conclude that the 5-mention PubGene method is more stringent than the 99th percentile of Poisson distribution method for extracting protein-protein interactions by co-occurrence of entity names and literature analysis may be a potential filter for microarray analysis to isolate potentially novel hypotheses for further research. / The availability of transcriptomics data from time-course experiments on mouse mammary glands examined during the lactation cycle and hormone-induced lactogenesis in mammary explants has permitted an assessment of similarity of gene expression at the transcriptional level. Global transcriptome analysis using exact Wilconox signed-rank test with continuity correction and hierarchical clustering of Spearman coefficient demonstrated that hormone-induced mammary explants behave differently to mammary glands at secretory differentiation. Our results demonstrated that the mammary explant culture model mimics in vivo glands in immediate responses, such as hormone-responsive gene transcription, but generally did not mimic responses to prolonged hormonal stimulus, such as the extensive development of secretory pathways and immune responses normally associated with lactating mammary tissue. Hence, although the explant model is useful to study the immediate effects of stimulating secretory differentiation in mammary glands, it is unlikely to be suitable for the study of secretory activation.

Orientador: José Antônio Dell'aqua Junior / Resumo: Tem sido relatado que altas concentrações de osteopontina (OPN) no plasma seminal de diversar espécies esta correlacionada com animais de alta fertilidade, identificando-a como bio marcador reprodutivo. De igual maneira estudos mostram uma maior taxa de fertilização in vitro quando é implementada nos meios para fertilização. Visto que a OPN pode ter funções antagônicas, o presente estudo visou identificar se suas funções são dose dependente, adicionando 4 diferentes concentrações de OPN sobre o sêmen sexado bovino por 30 minutos e avaliar por (i) citometria de fluxo a viabilidade, integridade de membrana e capacitação espermática; (ii) teste de ligação a células epiteliais da tuba uterina bovina (BOECs), para quantificar o numero de espermatozoides ligados às células epiteliais, formando o que seria in vivo o reservatório espermático e (iii) avaliar a produção de embriões in vitro. Na avaliação por citometria não foi observada uma interação da adição de OPN com os espermatozoides sexados e não sexados, diferente dos outros dois testes onde se evidenciou que independente da dose a OPN diminuiu a ligação dos espermatozoides às BOECs e a concentração de 0.5g/1x106 espermatozoides aumento a taxa de clivagem e formação de blastocistos. Isto ratifica o poder capacitante da OPN de 60KDa sobre os espermatozoides e confirma que esta, pode ter associações diretas com ambos gametos, gerando melhores taxas de fertilização in vitro e, por tanto, melhor desenvolvimento embrionário nos bovi... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: It has been reported that high concentrations of osteopontin (OPN) in the seminal plasma of diverse species is correlated with high fertility animals, identifying it as a bio-reproductive marker. Likewise studies show a higher rate of in vitro fertilization when it´s implemented in fertilization media. Since OPN may have antagonistic functions, the present study aimed to identify if its functions are dose-dependent, adding four different concentrations of OPN on the sex-sorted and non-sorted bovine sperm for 30 minutes. The samples were evaluated by means of (i) flow cytometry the viability, membrane integrity and sperm capacitation; (ii) sperm-binding assay to BOECs, to quantify the number of sperm attached to the epithelial cells, forming what would be in vivo the spermatic reservoir and (iii) to evaluate the in vitro embryo production. In flow cytometry an interaction of the addition of OPN with the sex-sorted and non-sorted sperm was not observed, different from the other two tests where it was evidenced that regardless of the dose, the OPN decreased the sperm binding to the BOECs and the concentration of 0.5 µg /1 x 106 spermatozoa increased the rate of cleavage and formation of blastocysts. This corroborates the capacitive power of the OPN of 60KDa on the spermatozoa, and confirm that it can have direct associations with both gametes, generating better rates of in vitro fertilization and, therefore, better embryonic development in cattle. However, from the results obtai... (Complete abstract click electronic access below) / Doutor

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