Designing crossing and selection strategies to combine diagnostic markers and quantitative traits

Tese de doutoramento em Biociências, ramo de especialização em Toxicologia, apresentada à Faculdade de Ciências e Tecnologia da Universidade de CoimbraDoxorubicin (DOX) is one of the most potent antineoplastic drugs. Although possessing a superior anti-­‐‑cancer activity, a broader clinical use of DOX is limited by a dose-­‐‑dependent, constant and cumulative cardiomyopathy involving deterioration of mitochondrial function. Although acute effects of DOX treatment often disappear when treatment finishes, chronic effects often result in a persistent cardiotoxicity, including a progressive deterioration of mitochondrial metabolism, the development of cardiomyopathy and ultimately congestive heart failure. Important in the context of DOX-­‐‑induced cardiotoxicity, mitochondrial disruption has been observed in different models. This alteration of mitochondrial function is often sub-­‐‑clinical and is only manifested as cardiomyopathy when other factors are combined, including age or different types of cardiovascular stress. Also, metabolic alterations in the cardiac cell occur, which contribute to the ability of the heart to withstand increased workloads. Although mitochondrial disruption is an early and sensitive marker of DOX cardiotoxicity, how metabolic stress contributes to the development of cardiomyopathy remains to be determined. Because of this gap in knowledge, the objective of this work was to use of model of metabolic inhibition in perfused hearts from saline (SAL) and DOX-­‐‑ treated rats in order to identify metabolic alterations caused by an acute and sub-­‐‑ chronic treatment. Our assumption for this strategy is that a lower susceptibility to a determined inhibitor during perfusion, would be a sign of a more robust (i.e. more capacity) of the targeted pathway(s). XV For the acute treatment protocol, sixteen week-­‐‑old male Wistar rats were i.p. injected with 20mg/Kg DOX or 1mg/Kg 0.9%NaCl and sacrificed 24 hours later. For sub-­‐‑ chronic protocol, eight weeks-­‐‑old male Wistar rats received seven weekly s.c. injections with DOX(2mg/Kg) or equivalent SAL solution and sacrificed one week after the last injection. Following the protocol treatments, animals were sacrificed and hearts were removed and perfused using a Langendorff apparatus with distinct cardiac substrates (glucose, galactose plus glutamine -­‐‑ GG or octanoate plus malate – OM). Glycolytic (iodoacetate) and oxidative phosphorylation (rotenone-­‐‑ Rot or cyanide-­‐‑ KCN) inhibitors were separately added to the different metabolic perfusates, aiming to detect undercover mitochondrial defects in the DOX-­‐‑treated group. In non-­‐‑perfused hearts, or hearts perfused in the absence (time controls, TC) or presence of inhibitors, selected metabolic and mitochondrial proteins were semi-­‐‑ quantified by Western blotting, and mRNA levels were quantified by RT-­‐‑PCR. In the acute DOX treatment model, hearts perfused with glucose as substrate suffered a decline in the number of heart beat and rate pressure product (RPP) when iodoacetate was added, contrarily to Rot or KCN which had no effect. With GG, inhibitor titration decreased the heart rate, despite that the decrease in the RPP was more evident in SAL vs. DOX group with iodoacetate and KCN. Perfusion with OM resulted in decreased heart rate an RPP in the presence of the inhibitors, showing equal response between treatments. When glycolytic and mitochondrial proteins were semi-­‐‑quantified by Western blotting, alterations in proteins involved in mitochondrial biogenesis and autophagy were observed in DOX hearts perfused with inhibitors. The data from the acute protocol study, appears to suggest that hearts from DOX-­‐‑treated animals have improved function in the presence of XVI metabolic inhibitors, thus indicating that DOX triggers adaptations that allow the hearts to be less susceptible to mitochondrial and glycolytic inhibition. In the sub-­‐‑chronic model and using glucose as substrate, the DOX-­‐‑treated group showed again a better tolerability to inhibitors than SAL. With GG, titration with iodoacetate caused a decrease in heart beat and on RPP in DOX group, when rot or KCN was added the number of heart beat and RPP remains identical between the two groups. Glycolytic and mitochondrial proteins semi-­‐‑quantification suggested an impairment of autophagy in DOX perfused hearts perfused, more evident during GG perfusion. The presence of inhibitors in the perfusion also generally decreased the total amount of proteins detected by Western Blotting, although glycolytic proteins were increased when hearts were perfused with glucose, contrarily to GG perfusion. The results suggest that sub-­‐‑chronic DOX-­‐‑treated rats suffered a metabolic remodeling which is based on stronger glycolytic fluxes to maintain contractility, although no overt mitochondrial defect was uncovered. A surprising result is that regardless of the perfusion buffer used, no striking differences between SAL and DOX hearts in terms of hemodynamic parameters were found. The present work suggests that metabolic remodeling during DOX acute and sub-­‐‑ chronic treatment maintains cardiac function in the treated animals. This remodeling is apparently based in a stronger contribution of glycolysis to overall metabolism. Data from protein amount analyzed suggest that DOX treatment in both models affect important regulators of autophagy, mitochondrial biogenesis as well as the adenine nucleotide translocator. The results also suggest that a longer treatment XVII protocol or resting period should also be tested in order to uncover more profound differences.A doxorrubicina (DOX) é um dos fármacos antineoplásicos mais potentes. Apesar de possuir uma actividade anti-­‐‑cancro superior, uma mais ampla utilização clínica da DOX é limitada por uma dose-­‐‑dependente, constante e cumulativa cardiomiopatia que envolve a deterioração da função mitocondrial. Embora os efeitos agudos do tratamento DOX normalmente desaparece quando se conclui o tratamento, os efeitos crónicos resultam muitas vezes numa cardiotoxicidade persistente, incluindo a deterioração progressiva do metabolismo mitocondrial, o desenvolvimento de cardiomiopatia e por fim insuficiência cardíaca congestiva. Importante no contexto da cardiotoxicidade induzida pela DOX, perturbação mitocondrial foi observada em diferentes modelos. Esta alteração da função mitocondrial é muitas vezes sub-­‐‑clínica e só se manifesta como cardiomiopatia quando outros factores são combinados, incluindo a idade ou diferentes tipos de estresse cardiovascular. Além disso, ocorrem alterações metabólicas na célula cardíaca, o que contribui para a capacidade do coração resistir a maior demanda. Embora a perturbação mitocondrial seja um marcador precoce e sensível de DOX cardiotoxicidade, como o stress metabólico contribui para o desenvolvimento de cardiomiopatia permanece por determinar. Devido a essa lacuna no conhecimento, o objetivo deste trabalho foi a utilização de um modelo de inibição metabólica em corações perfundidos de ratos tratados com uma solução salina (SAL) e ratos tratados com DOX, a fim de identificar alterações metabólicas causadas por um tratamento agudo e sub-­‐‑crônico. XIX O nosso pressuposto para esta estratégia é que uma menor susceptibilidade a um determinado inibidor durante a perfusão, seria um sinal de uma forma mais robusta (ou seja, mais de capacidade) da via-­‐‑alvo (s). Para o protocolo de tratamento agudo, ratos machos Wistar de 16 semanas de idade foram injectados i.p. com 20 mg / kg de DOX ou de 1 mg / kg a 0,9% de NaCl e sacrificados 24 horas mais tarde. Para o protocolo sub-­‐‑crônico, ratos machos Wistar de oito semanas de idade, receberam sete injecções s.c. semanais com DOX (2 mg / kg) ou uma equivalente da solução SAL sendo sacrificados uma semana após a última injecção. Após o protocolo de tratamentos, os animais foram sacrificados e os corações foram perfundidos com um aparelho de Langendorff com substratos cardíacos distintos (glucose, galactose mais glutamina -­‐‑ GG ou octanoato mais malato -­‐‑ OM). Inibidores glicolíticos (iodoacetato) e inibidores da fosforilação oxidativa (Rot-­‐‑ rotenona ou KCN-­‐‑ cianeto) foram adicionados separadamente nos diferentes substratos metabólicos, com o objetivo de detectar defeitos mitocondriais no grupo tratado com DOX. Em corações não perfundidos, ou corações perfundidos na ausência (controlos de tempo, TC) ou na presença de inibidores, algumas proteínas metabólicas e proteínas mitocondriais foram semi-­‐‑quantificadas por Western blotting, e os níveis de mRNA foram quantificados por RT-­‐‑PCR. No modelo de tratamento agudo DOX, corações perfundidos com glucose como substrato sofreram um declínio no número de batimentos cardíacos e produto da taxa de pressão (RPP), quando iodoacetato foi adicionado, ao contrário da Rot ou KCN, que não teve nenhum efeito. Com GG, a titulação com o inibidor diminuiu a frequência cardíaca, apesar de que a diminuição da RPP foi mais evidente no grupo SAL vs. DOX com iodoacetato e KCN. Perfusão com OM resultou em diminuição da XX frequência cardíaca e do RPP na presença dos inibidores, mostrando uma resposta igual entre os tratamentos. Quando proteínas glicolíticas e mitocondriais foram semi-­‐‑ quantificadas por Western blotting, alterações de proteínas envolvidas na biogênese mitocondrial e autofagia foram observados em corações DOX perfundidos com inibidores. Os dados do protocolo de estudo agudo, parecem sugerir que os corações provenientes de animais tratados com DOX na presença de inibidores, têm a função metabólica melhorada, indicando assim que a DOX desencadeia adaptações que permitem que os corações sejam menos susceptíveis à inibição mitocondrial e glicolítica. No modelo sub-­‐‑crónica e utilizando glucose como substrato, o grupo tratado com DOX mostrou novamente um melhor tolerabilidade para inibidores que SAL. Com GG, a titulação com iodoacetato causou uma diminuição no batimento cardíaco e no RPP em grupo DOX, quando rot ou KCN foi adicionado o número de batimentos cardíacos e RPP permaneceram idênticos entre os dois grupos. A semi-­‐‑quantificação de proteínas glicolíticas e mitocondriais sugerem uma deficiência da autofagia em corações DOX perfundidos, mais evidente durante a perfusão com GG. A presença de inibidores da perfusão geralmente também reduziu a quantidade total de proteínas detectadas através de Western Blot, embora proteínas glicolíticas aumentaram quando os corações foram perfundidos com glucose, ao contrário da perfusão com GG. Os resultados sugerem que ratos tratados sub-­‐‑cronicamente com DOX sofreram uma remodelação metabólica, que é baseado em fluxos glicolíticos mais fortes para manter a contratilidade, embora nenhum defeito mitocondrial ostensivo foi descoberto. XXI Um resultado surpreendente é que, independentemente do tampão de perfusão utilizado, não foram encontradas diferenças marcantes entre SAL e DOX corações em termos de parâmetros hemodinâmicos. O presente trabalho sugere que o remodelação metabólica durante o tratamento agudo e sub-­‐‑crônico com DOX, mantém a função cardíaca nos animais tratados. Esta remodelação é, aparentemente, baseado numa contribuição mais forte da glicólise ao metabolismo geral. Os resultados de quantidade de proteína analisados sugerem que o tratamento com DOX em ambos os modelos afectam importantes reguladores da autofagia e biogénese mitocondrial, bem como o translocador de nucleótidos de adenina. Os resultados também sugerem que um protocolo de tratamento mais longo ou com um período de repouso também devem ser testados a fim de descobrir diferenças mais profundas

Genetic improvement of wheat for dry environments - a trait based approach

Item does not contain fulltext23 januari 201

Labrador retrievers under primary veterinary care in the UK: demography, mortality and disorders

Abstract Background Labrador retrievers are reportedly predisposed to many disorders but accurate prevalence information relating to the general population are lacking. This study aimed to describe demography, mortality and commonly recorded diseases in Labrador retrievers under UK veterinary care. Methods The VetCompass™ programme collects electronic patient record data on dogs attending UK primary-care veterinary practices. Demographic analysis covered all33,320 Labrador retrievers in the VetCompass™ database under veterinary care during 2013 while disorder and mortality data were extracted from a random sample of 2074 (6.2%) of these dogs. Results Of the Labrador retrievers with information available, 15,427 (46.4%) were female and 15,252 (53.6%) were male. Females were more likely to be neutered than males (59.7% versus 54.8%, P <  0.001). The overall mean adult bodyweight was 33.0 kg (SD 6.1). Adult males were heavier (35.2 kg, SD 5.9 kg) than adult females (30.4 kg, SD 5.2 kg) (P <  0.001). The median longevity of Labrador retrievers overall was 12.0 years (IQR 9.9–13.8, range 0.0–16.0). The most common recorded colours were black (44.6%), yellow (27.8%) and liver/chocolate (reported from hereon as chocolate) (23.8%). The median longevity of non-chocolate coloured dogs (n = 139, 12.1 years, IQR 10.2–13.9, range 0.0–16.0) was longer than for chocolate coloured animals (n = 34, 10.7 years, IQR 9.0–12.4, range 3.8–15.5) (P = 0.028). Of a random sample of 2074 (6.2%) Labrador retrievers under care in 2013 that had full disorder data extracted, 1277 (61.6%) had at least one disorder recorded. The total number of dogs who died at any date during the study was 176. The most prevalent disorders recorded were otitis externa (n = 215, prevalence 10.4%, 95% CI: 9.1–11.8), overweight/obesity (183, 8.8%, 95% CI: 7.6–10.1) and degenerative joint disease (115, 5.5%, 95% CI: 4.6–6.6). Overweight/obesity was not statistically significantly associated with neutering in females (8.3% of entire versus 12.5% of neutered, P = 0.065) but was associated with neutering in males (4.1% of entire versus 11.4% of neutered, P < 0.001). The prevalence of otitis externa in black dogs was 12.8%, in yellow dogs it was 17.0% but, in chocolate dogs, it rose to 23.4% (P < 0.001). Similarly, the prevalence of pyo-traumatic dermatitis in black dogs was 1.1%, in yellow dogs it was 1.6% but in chocolate dogs it rose to 4.0% (P = 0.011). Conclusions The current study assists prioritisation of health issues within Labrador retrievers. The most common disorders were overweight/obesity, otitis externa and degenerative joint disease. Males were significantly heavier females. These results can alert prospective owners to potential health issues and inform breed-specific wellness checks

Effects of a single administration of prostaglandin F2alpha, or a combination of prostaglandin F2alpha and prostaglandin E2, or placebo on fertility variables in dairy cows 3–5 weeks post partum, a randomized, double-blind clinical trial

BACKGROUND: Delayed uterine involution has negative effects on the fertility of cows; use of prostaglandin F2alpha alone as a single treatment has not been shown to consistently improve fertility. Combined administration of PGF2alpha and PGE2 increased uterine pressure in healthy cows. We hypothesized, that the combination of both prostaglandins would accelerate uterine involution and have, therefore, a positive effect on fertility variables. In commercial dairy farming, the benefit of a single post partum combined prostaglandin treatment should be demonstrated. METHODS: 383 cows from commercial dairy farms were included in this study. Uterine size and secretion were evaluated at treatment 21–35 days post partum and 14 days later. Cows were randomly allocated to one of three treatment groups: PGF2alpha and PGE2, PGF2alpha or placebo. For every animal participating in the study, the following reproduction variables were recorded: Interval from calving to first insemination, days open, number of artificial inseminations (AI) to conception; subsequent treatment of uterus, subsequent treatment of ovaries. Plasma progesterone level at time of treatment was used as a covariable. For continuous measurements, analysis of variance was performed. Fisher's exact test for categorical non-ordered data and exact Kruskal-Wallis test for ordered data were used; pairwise group comparisons with Bonferroni adjustment of significance level were performed. RESULTS: There was no significant difference among treatment groups in uterine size. Furthermore, there was no significant difference among treatments concerning days open, number of AI, and subsequent treatment of uterus and ovaries. Days from calving to first insemination tended to be shorter for cows with low progesterone level given PGF2alpha and PGE2 in combination than for the placebo-group (P = 0.024). CONCLUSION: The results of this study indicate that the administration of PGF2alpha or a combination of PGF2alpha and PGE2 21 to 35 days post partum had no beneficial effect upon measured fertility variables. The exception was a tendency for a shorter interval from calving to first insemination after administration of the combination of PGF2alpha and PGE2, as compared to the placebo group. Further research should be done in herds with reduced fertility and/or an increased incidence of postpartum vaginal discharge

Sugarcane (Saccharum X officinarum): A Reference Study for the Regulation of Genetically Modified Cultivars in Brazil

Global interest in sugarcane has increased significantly in recent years due to its economic impact on sustainable energy production. Sugarcane breeding and better agronomic practices have contributed to a huge increase in sugarcane yield in the last 30 years. Additional increases in sugarcane yield are expected to result from the use of biotechnology tools in the near future. Genetically modified (GM) sugarcane that incorporates genes to increase resistance to biotic and abiotic stresses could play a major role in achieving this goal. However, to bring GM sugarcane to the market, it is necessary to follow a regulatory process that will evaluate the environmental and health impacts of this crop. The regulatory review process is usually accomplished through a comparison of the biology and composition of the GM cultivar and a non-GM counterpart. This review intends to provide information on non-GM sugarcane biology, genetics, breeding, agronomic management, processing, products and byproducts, as well as the current technologies used to develop GM sugarcane, with the aim of assisting regulators in the decision-making process regarding the commercial release of GM sugarcane cultivars