• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 7
  • 5
  • 3
  • Tagged with
  • 35
  • 35
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

The metabolic cost of an intestinal parasite infection on amino acid kinetics in sheep fed fresh forages: a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, New Zealand

Bermingham, Emma Natasha January 2004 (has links)
There is mounting evidence that parasitic infections change nutrient utilisation within the tissues, and that this is responsible for the reduction in animal performance that has been observed. Feeding forages that contain condensed tannins (CT) are thought to alleviate the impact of parasite infection on amino acid (AA) and protein metabolism by improving protein supply post-ruminally. However, there has been no quantification of how nutrients are partitioned in the lamb fed fresh forages during a parasitic infection. Therefore, the objective of this study was to quantify the partitioning of AA between the gastrointestinal tract (GIT), liver and the hind limb tissues (muscle, skin, fat) in lambs during an established parasite infection. It was hypothesised that the feeding of CT would alter the partitioning of AA between the GIT, liver and hind limbs in lambs with an established parasite burden due to the increased availability of dietary AA to the small intestine. This hypothesis was tested in two separate experiments, which had a similar experimental design. In the first experiment (Experiment One; 1999) lambs were fed fresh Lucerne (Medicago sativa; contains no CT). In Experiment Two, which was conducted in 2000, the lambs were fed fresh Sulla (Hedysarum coronarium; 2.2% CT; Experiment Two). One week prior to infection, permanent indwelling catheters were placed in the mesenteric artery, and the mesenteric, portal and hepatic veins and vena cava for blood sampling. Additional permanent catheters were placed in the mesenteric vein (upstream from the sampling catheter) and abdominal aorta for infusion of para-aminohippuric acid (PAH) and indocyanin green (ICG) respectively, to measure plasma flow across the splanchnic tissues (PAH) and the hind limbs (ICG). A permanent Teflon cannula was fitted in the abomasum for the infusion of [1-13C]-valine and [35S]-cysteine (Chapters Five, Six and Seven only) on day 48 post infection to measure valine and cysteine kinetics across the mesenteric-drained viscera (MDV), portal-drained viscera (PDV), liver, total splanchnic tissues (TSP; PDV + liver) and hind limbs. A temporary catheter was inserted into the jugular vein two days before the start of blood sampling for the infusion of deuterium oxide (D2O), and [13C]-sodium bicarbonate and [35S]-sulfate (Chapters Five, Six and Seven only) on day 45 post infection, and [3,4-3H]-valine on day 48 post infection. Lambs were dosed with 6 000 L3 T. colubriformis larvae for 6 d (n=5) or kept as parasite free controls (n=6). Faecal egg production was monitored every second day from day 22 to day 48 post infection and total intestinal worm burdens were determined at slaughter. Blood was continuously collected from the mesenteric, portal and hepatic veins, the mesenteric artery and the vena cava in 2-hour aliquots. Plasma was harvested and AA and metabolite concentrations measured and the specific radioactivity (SRA) and isotopic enrichment (IE) of valine and cysteine were determined. After the completion of blood sampling, but while the [3, 4-3H]-valine infusate was still being administered, the sheep were euthanased by an intravenous overdose of sodium pentobarbitone. Tissue samples were rapidly collected from the sheep in the following order: skin, muscle (biceps femoris), liver, duodenum, ileum, spleen, mesenteric lymph nodes and thymus. Digesta was also sampled from the abomasum and ileum after slaughter in order for the apparent absorption of AA to be determined. The results from Experiment One (Lucerne-fed lambs) suggest that there is no re-partitioning of AA from the posterior hind limbs to the GIT and liver during an established infection- The changes that occurred within the PDV suggests that an established parasitic infection may trigger a localised alteration in AA metabolism and/or protein turnover without significantly changing the metabolism of AA and proteins in tissues peripheral to the TSP tissues and impacting negatively on the growth of the parasitised lambs. In Experiment Two (Sulla-fed lambs) a reduction in feed intake was likely to be the reason for the alterations in the first pass metabolism of AA in the TSP tissues due to the decreased apparent AA absorption by the MDV observed in the parasitised lambs. However, the results from this experiment are in agreement with those from Experiment One confirming that there is no increase in partitioning of AA from the hind limbs to the GIT or liver during an established parasite infection. Although a statistical comparison cannot be made between the data in Experiment One (Lucerne-fed) and Experiment Two (Sulla-fed), it appears that the beneficial effects of feeding CT during a parasitic infection is due to the reduction in larval establishment in the GIT of the lamb, rather than increased AA availability. In conclusion, an established infection imposes no measurable metabolic cost on the lamb, when feed intake is not reduced. When feed intake is reduced, there is no detectable mobilisation of protein from the hind limb. Therefore, localised or other sources of AA and/or energy substrates may be utilised.
32

Parasitoses intestinais, estado nutricional e diversidade genética de Giardia duodenalis em crianças atendidas em centro de educação infantil de Itapetininga, São Paulo.

Corrêa, Claudia Rosana Trevisani January 2018 (has links)
Orientador: Semiramis Guimarães Ferraz Viana / Resumo: Os centros de educação infantil destacam-se como ambientes para a promoção do desenvolvimento social e cultural da criança em idade pré-escolar, garantindo a oportunidade de uma vida mais saudável, inclusive pela possibilidade de uma alimentação adequada na infância. Entretanto, esses ambientes apresentam características epidemiológicas que favorecem a transmissão de patógenos incluindo os parasitas intestinais. O presente estudo transversal foi conduzido com crianças com idade variando de nove a 71 meses atendidas em EMEI do município de Itapetininga, SP, e teve como objetivos: (1) estimar a frequência de parasitas intestinais, (2) avaliar a diversidade genética de isolados de Giardia duodenalis e (3) avaliar o estado nutricional das crianças, segundo parâmetros antropométricos e dietéticos. De 140 crianças formalmente autorizadas a participar do estudo, 105 forneceram amostra de fezes, 108 tiveram os questionários preenchidos e 131 foram submetidas à avaliação antropométrica. Para a pesquisa de enteroparasitas, as amostras de fezes foram processadas pelos métodos de centrifugo-sedimentação e flutuação com sulfato de zinco. A avaliação do perfil nutricional incluiu parâmetros antropométricos (escore -Z para os índices peso/idade, peso/estatura, estatura/peso e IMC) e dietéticos (análise do cardápio quanto aos valores de macronutrientes). Para a detecção e caracterização moleculares de isolados de Giardia, o DNA extraído das amostras de fezes (oito amostras positivas e 97 amo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The centers of early childhood education stand out as environments to promote the social and cultural development of pre-school children, providing the opportunity for a healthy life, including the possibility of an adequate diet in childhood. In contrast, these environments present epidemiological characteristics that favor the transmission of pathogens including intestinal parasites. The present cross-sectional study was conducted with children ranging in age from 9 to 71 months attending the EMEI in the city of Itapetininga, State of São Paulo, and had the following objectives: (1) to estimate the frequency of intestinal parasites; (2) to evaluate the genetic diversity of isolates of Giardia duodenalis and (3) to evaluate the nutritional status of children according to anthropometric and dietary parameters. Out of 140 children who were formally authorized to participate in the study, 105 provided a stool sample, 108 had completed questionnaires and for 131, weight and height measurements were obtained for anthropometric evaluation. For the study of enteroparasites, the stool samples were processed by centrifugation-sedimentation and zinc sulfate flotation methods. Nutrition profile evaluation included anthropometric parameters (Z-score for weight /age, weight/height, height/weight and BMI) and dietary (macronutrient values). For the detection and molecular characterization of Giardia duodenalis isolates, DNA extracted from faeces samples (eight positive samples and 97 samp... (Complete abstract click electronic access below) / Mestre
33

Comparação de técnicas coproparasitológicas para o diagnóstico de protozoários e helmintos intestinais de importância médica

Ribeiro, Steveen Rios 18 March 2011 (has links)
Made available in DSpace on 2016-12-23T13:56:08Z (GMT). No. of bitstreams: 1 Dissertacao de Steveen Rios Ribeiro.pdf: 4201771 bytes, checksum: 56acf4462c81abd472caf4c84eb8dd80 (MD5) Previous issue date: 2011-03-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Introduction. The diagnosis of intestinal parasites can be accomplished by different techniques of parasitological stool examinations (EPF), each with advantages and disadvantages according to the parasite to be identified. Aims. The aim of the present study was to compare traditional techniques of EPF (Spontaneous Sedimentation in Tube, Kato-Katz and Baermann-Moraes) with more sophisticated techniques (stool culture, detection of coproantigen and PCR) and two commercially available kits in Brazil (Paratest® and TF-Test ®). Material and Methods. Faecal samples from 160 individuals, a total of 356 samples, were analyzed by traditional techniques of EPF (Spontaneous Sedimentation in Tube, Kato-Katz and Baermann-Moraes), culture of fresh faeces and sediment of feces, detection of coproantigen, PCR for detection and differentiation of the complex Entamoeba histolytica/Entamoeba dispar and two commercially available kits in Brazil (Paratest® and TF-Test®). Results. The technique of Spontaneous Sedimentation in Tube had better sensitivity (80.43% of occurrences) for the diagnosis of eggs and larvae of helminths in feces. The Kato-Katz was better for identification of eggs of S. mansoni (100% of cases). The method of Baermann-Moraes found larvae of Strongyloides stercoralis detected similarly to spontaneous sedimentation. For the diagnosis of G. lamblia, C. parvum and E. histolytica, kits for detection of coproantigen showed better sensitivity. The stool culture showed excellent results for identification of Blastocystis hominis. The PCR was able to identify and differentiate the amoebas of the complex E. histolytica/ E. dispar. Both commercial kits showed lower sensitivity than the spontaneous sedimentation for the diagnosis of helminths, but Paratest® was the technique that has shown better sensitivity for protozoa (66.66% of cases). Conclusion. For the diagnosis of helminths, the Spontaneous Sedimentation Method in Tube showed better results, except for detection of eggs of S. mansoni, best detected by Kato-Katz. For the diagnosis of G. lamblia, E. histolytica and Cryptosporidium parvum, kits for detection of coproantigen were better. However, the kit for the diagnosis of E. histolytica does not detect the species E. dispar, best identified by the ABSTRACT PCR. The commercial kits (Paratest® and TF-Test ®), while facilitating the collection and preservation of the sample, have lower sensitivity than the Spontaneous Sedimentation method in Tube / O diagnóstico de parasitoses intestinais pode ser realizado por diferentes técnicas de Exame Parasitológico de Fezes (EPF), cada uma com vantagens e desvantagens de acordo com o parasito a ser identificado. Objetivos. Comparar técnicas tradicionais de EPF (Sedimentação Espontânea em Tubo, Kato-Katz e Baermann-Moraes) com técnicas mais sofisticadas (cultura de fezes, detecção de coproantígenos e PCR) e dois kits comerciais disponíveis no Brasil (Paratest® e TF-Test®). Material e Métodos. Amostras de fezes de 160 indivíduos, totalizando 356 amostras, foram analisadas por técnicas tradicionais de EPF (Sedimentação Espontânea em Tubo, Kato-Katz e Baermann-Moraes), cultura de fezes frescas e de sedimento de fezes, técnicas para detecção de coproantígenos nas fezes, PCR para detecção e diferenciação de Entamoeba do complexo histolytica/dispar e dois kits comerciais disponíveis no Brasil (Paratest® e TF-Test®). Resultados. A técnica de Sedimentação Espontânea em Tubo demonstrou melhor sensibilidade (80,43% das o corrências) para o diagnóstico de ovos e larvas de helmintos nas fezes. O Kato-Katz foi melhor para identificação de ovos do S. mansoni (100% das ocorrências). Já o método de Baermann-Moraes detectou larvas de Strongyloides stercoralis de modo semelhante à sedimentação espontânea. Para o diagnóstico de G. lamblia, C. parvum e E. histolytica, os kits de coproantígenos demonstraram melhor sensibilidade. A cultura de fezes mostrou excelentes resultados para identificação de Blastocystis hominis. O PCR conseguiu identificar e diferenciar as amebas do complexo E. histolytica/E. dispar. Os dois kits comerciais apresentaram sensibilidade mais baixa do que a Sedimentação Espontânea em Tubo para o diagnóstico de helmintos, mas o Paratest® foi a técnica que demonstrou melhor sensibilidade para protozoários (66,66% das ocorrências). Conclusão. Para o diagnóstico de helmintos o método de Sedimentação Espontânea em Tubo foi o que mostrou melhor resultado, exceto para detecção de ovos de S. mansoni, melhor detectados pelo Kato-Katz. Os kits de detecção de coproantígenos foram melhores para diagnóstico de G. lamblia, Cryptosporidium parvum e E. histolytica. Entretanto, o kit para diagnóstico de E. histolytica não detecta a espécie E. dispar, melhor identificada pelo PCR. Os kits comerciais (Paratest® RESUMO e TF-Test®), apesar de facilitarem a coleta e conservação da amostra, têm menor sensibilidade do que a Sedimentação Espontânea em Tubo
34

Host–parasite interactions of boreal forest grouse and their intestinal helminth parasites

Isomursu, M. (Marja) 29 January 2014 (has links)
Abstract Parasites are an inseparable part of the life of wild birds. They may cause morbidity, mortality or reduction in fecundity. Parasite distribution in hosts is typically not uniform and many host factors (e.g. age) may affect the pattern of distribution. Under certain conditions, parasites even have the potential to regulate the host population. The grouse species of Finnish forests — the capercaillie Tetrao urogallus , the black grouse Lyrurus tetrix and the hazel grouse Tetrastes bonasia — harbour several species of intestinal helminth parasites. The populations have fluctuated in cyclic manner but the mechanisms behind the cycles are largely unknown. I studied the interactions of forest grouse and their intestinal helminth parasites by using intestinal samples collected by hunters in five game management districts during eight years (1995–2002). The most common parasite species in the samples was the nematode Ascaridia compar. Also, three species of cestodes (Skrjabinia cesticillus, Paroniella urogalli and Hymenolepis sp.) were found. Large size, male gender and age over 1 year were connected with an increased probability and intensity of A. compar infection. Juvenile grouse were commonly infected with cestodes while in adults infections were quite rare. The influence of inbreeding on the susceptibility to parasite infections was studied in the capercaillie by analysing microsatellite heterozygosity. The less heterozygous birds were more likely to be infected with A. compar and were more intensely infected suggesting negative influence of inbreeding on parasite resistance. An indirect negative effect of parasites was found by comparing bags hunted with a trained dog or without a dog. Grouse infected by cestodes were significantly more common in the dog-assisted bag. Thus, cestode infection seemed to make grouse more vulnerable to canine predation. The interaction between grouse population dynamics and parasites was studied by analyzing the grouse densities obtained from annual wildlife counts and parasite indices. A. compar was most common and most abundant in the years of grouse population decline. The grouse population growth rate was negatively correlated with the annual mean abundance of A. compar. Relative survival but not breeding success decreased as the abundance of A. compar increased. The findings suggest that A. compar influences the dynamics of Finnish grouse even though regular cyclic dynamics are no longer evident. / Tiivistelmä Loiset kuuluvat erottamattomana osana luonnonvaraisten lintujen elämään. Ne voivat aiheuttaa sairautta, kuolleisuutta tai hedelmällisyyden alentumista. Tyypillisesti loiset ovat levinneet isäntäpopulaatioon epätasaisesti ja monet isännän ominaisuudet (esim. ikä) vaikuttavat levinneisyyteen. Tietyissä oloissa loiset voivat jopa säädellä isäntäpopulaatiotaan. Suomalaiset metsäkanalinnut — metso Tetrao urogallus, teeri Lyrurus tetrix ja pyy Tetrastes bonasia — ovat useiden suolistoloismatolajien isäntiä. Metsäkanapopulaatiot ovat vaihdelleet syklisesti, mutta syklejä aiheuttavat mekanismit ovat yhä tuntemattomia. Tutkin metsäkanalintujen ja niiden suolistoloisten välisiä vuorovaikutuksia käyttäen metsästäjien vuosina 1995–2002 viidestä eri riistanhoitopiiristä keräämiä suolistonäytteitä. Yleisin loislaji näytteissä oli kanalintusuolinkainen, Ascaridia compar. Myös kolme heisimatolajia (Skrjabinia cesticillus, Paroniella urogalli ja Hymenolepis sp.) todettiin. Suuri koko, koirassukupuoli ja yli yhden vuoden ikä olivat yhteydessä suurempaan kanalintusuolinkaistartunnan todennäköisyyteen ja voimakkuuteen. Nuorilla (alle 1 v.) linnuilla heisimadot olivat yleisiä, kun taas aikuisilla tartunnat olivat varsin harvinaisia. Sisäsiittoisuuden vaikutusta loistartuntaherkkyyteen tutkittiin metsolla mikrosatelliittiheterotsygotian perusteella. Vähemmän heterotsygoottiset metsot olivat todennäköisemmin ja voimakkaammin suolinkaisten infektoimia, mikä viittaa sisäsiittoisuuden negatiiviseen vaikutukseen loisten vastustuskykyyn. Loisten epäsuora haitallinen vaikutus havaittiin, kun verrattiin koiran kanssa ja ilman koiraa metsästettyä lintusaalista. Heisimadot olivat selvästi yleisempiä linnuilla, jotka oli metsästetty koiran kanssa kuin ilman koiraa metsästetyillä. Heisimatotartunta näytti siis altistavan metsäkanoja koiraeläinten saalistukselle. Metsäkanalintu- ja loispopulaatioiden välistä vuorovaikutusta tutkittiin analysoimalla vuosittaisia metsäkanatiheyksiä ja loisten runsautta. Kanalintusuolinkainen oli yleisimmillään ja runsaimmillaan metsäkanatiheyden laskuvuosina. Metsäkanapopulaation vuosittainen kasvuvauhti korreloi negatiivisesti kanalintusuolinkaisen vuosittaisen runsauden kanssa. Suhteellinen elossasäilyvyys laski kanalintusuolinkaisen runsauden lisääntyessä, mutta lisääntymistuloksen suhteen ei ollut samaa ilmiötä. Löydökset viittaavat siihen, että kanalintusuolinkaisella on vaikutusta suomalaisten metsäkanalintukantojen vaihteluihin, vaikka syklisiä kannanvaihteluja ei enää havaitakaan.
35

Výskyt a sezónní dynamika parazitů střev u dostihových koní / The occurrence and the seasonal dynamic of the intestinal parasites by racing horses

WAGENKNECHTOVÁ, Adéla January 2009 (has links)
The diploma work The occurrence and the seasonal dynamic of the intestinal parasite by racing horses deals with the occurrence of intestinal parasites by individual horse-age categories, parasites{\crq} prevalence in comparison to annual seasons. The helminthes with highest prevalence {--} small and large Strongylus, Strongyloides westeri, Parascaris equorum, Oxiuris Equi {--} are described in the work.

Page generated in 0.0985 seconds