962 resultados para screw-worm
Resumo:
Dioctophymosis is a worldwide renal parasitosis caused by the Dioctophyma renale nematode, which results in progressive destruction of renal tissue. Aquatics annelids are considered the main intermediate hosts and the literature refers as permanent hosts of dogs, wild mammals and even humans. During procedures for population control of coatis (Nasua nasua) in the Ecological Park of Tietê (PET), was noticed the presence of parasitosis by D. renale. From 68 animals, males and females, young and adults, submitted to exploratory laparotomy, 51 were positive for the presence of worms, 9 were found only in the right kidney. In 10 cases, in addition to right kidney parasitism, worms were also observed in the abdominal cavity. In 24 cases D. renale was found only in the abdominal cavity and in 8 animals the right kidney was reduced to a small rigid structure. The study showed that the preferred site for parasitism of the worm, considered erratic, was the abdominal cavity in 66.66% of the cases.
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This study aimed to evaluate the variability in the fecal egg count (FEC) and the parasitic burden of naive hair sheep after grazing in nematode infected paddocks. The research was carried out in Tabasco, Mexico, during two periods (August and December). In each period 32 lambs were grazed for one month on African star grass (Cynodon plectostachyus) contaminated with gastrointestinal parasitic nematodes. FEC, packed cell volume (PCV) and body weight (BW) were recorded. Gastrointestinal worms were recovered at necropsy. Data were analyzed with the MIXED procedure of SAS using a model of repeated measurements over time. A higher number of Haemonchus contortus worms was found in December (2814±838) than in August (1166±305). The opposite occurred with Cooperia curticei (2167±393 and 3638±441, respectively). The FEC and correlation coefficient in respect to the worm burden were higher in December (6516 ± 1599, r=0.83, respectively) than in August (4364±771, r=0.44, respectively). A high variability in resistance-susceptibility to gastrointestinal nematodes (GIN) occurred in Katahdin × Pelibuey lambs after grazing.
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Abstract:Trematodes belonging to the family Eucotylidae, including Tanaisia(Paratanaisia)bragaiSantos, 1934are parasites of the kidney and ureter that affect several species of domestic and wild birds. Tanaisia bragaiis considered a low pathogenic parasite, but high worm burdens may determine clinical complications, including signs of apathy, weight loss, diarrhea and death. This paper describes the first report of infection by T. bragai in peacocks (Pavo cristatus), which constitutes a new host record and offers data on the lesions associated to this parasitism, although the degree of pathogenicity and parasite load may be considered mild. These birds did not exhibit clinical signs of parasitism. The macroscopic exam revealed discreet yellow spots on the liver. In the histological sections of the kidney, specimens of T. bragai were found in the collecting ducts, which were markedly dilated, with a thickened wall. Other findings included a mild inflammatory reaction in the wall of the ducts (but sometimes absent), flattening of lining epithelial cells and small, multifocal points of calcification around the collecting ducts. The microscopic examination of the parasites revealed trematodes with an elongated body, well-developed sub terminal oral sucker, pharynx present, short esophagus, cecum somewhat undulating or not, with blind end, testes symmetrical, equatorial, irregular in shape or slightly lobed, vitelline fields extending in both pre-ovarian and post ovarian fields, uterus very long, intercecal or sometimes overlapping the cecum and containing large quantities of eggs. The present findings suggest the need for further diagnostic studies on the prevalence of this trematode in peacocks as well as pathologic studies for the determination of the potential pathogenicity of this parasite in this species of bird. Moreover, infected peacocks could serve as carriers of T. bragai to be transferred to other bird species, thereby contributing to the dispersion of the parasite.
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The aim of this thesis was to research how slurry’s viscosity and rheology affect to pumping in peristaltic hose pump and in eccentric progressive cavity pump. In addition, it was researched the formed pressure pulsation in hose pump. Pressure pulsation was studied by pumping different slurries and by using different pipe materials. Pressure and power curves were determined for both used pumps. It was also determined NPSHR curve for the progressive cavity pump. Literature part of the thesis considered to distribute fluids to different rheology types, as well as theories and models to identify different rheology types. Special attention was paid to non-Newtonian fluids, which were also used in experimental part of this thesis. In addition, the literature part discusses about pumps, parameters for pump sizing, and pressure pulsation in hose pump. Starch, bentonite, and carboxymethyl cellulose slurries were used in the experimental part of this thesis. The slurries were pumped with Flowrox peristaltic hose pump (LPP-T32) and eccentric progressive cavity pump (C10/10). From the each slurry was taken a sample, and the samples were analyzed for concentration, viscosity and rheology type. The used pipe materials in pressure pulsation experiments were steel and elastic, and it was also used a prototype of pulsation dampener. The pulsation experiments indicated that the elastic pipe and the prototype of pulsation dampener attenuated pressure pulsation better than the steel pipe at low pressure levels. The differences between different materials disappeared when pressure level and pump rotation speed increased. In slurry experiments, pulsation was different depending on rheology and viscosity of the slurry. According to experiments, the rheology did not significantly affect to pump power consumption or efficiency.
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The role of different cytokines in the peripheral blood mononuclear cell (PBMC) proliferative response and in in vitro granuloma formation was evaluated in a cross-sectional study with patients with the different clinical forms and phases of Schistosoma mansoni infection, as well as a group of individuals "naturally" resistant to infection named normal endemic (NE). The blockage of IL-4 and IL-5 using anti-IL-4 and anti-IL-5 antibodies significantly reduced the PBMC proliferative response to soluble egg (SEA) and adult worm (SWAP) antigens in acute (ACT), chronic intestinal (INT) and hepatosplenic (HS) patients. Similar results were obtained in the in vitro granuloma formation. Blockage of IL-10 had no significant effect on either assay using PBMC from ACT or HS. In contrast, the addition of anti-IL-10 antibodies to PBMC cultures from INT patients significantly increased the proliferative response to SEA and SWAP as well as the in vitro granuloma formation. Interestingly, association of anti-IL-4 and anti-IL-10 antibodies did not increase the PBMC proliferative response of these patients, suggesting that IL-10 may act by modulating IL-4 and IL-5 secretion. Addition of recombinant IL-10 decreased the proliferative response to undetectable levels when PBMC from patients with the different clinical forms were used. Analysis of IFN-g in the supernatants showed that PBMC from INT patients secreted low levels of IFN-g upon antigenic stimulation. In contrast, PBMC from NE secreted high levels of IFN-g. These data suggest that IL-10 is an important cytokine in regulating the immune response and possibly controlling morbidity in human schistosomiasis mansoni, and that the production of IFN-g may be associated with resistance to infection.
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Voimansiirtolinjojen ristikkopylväiden rakentamisessa on tyypillisesti käytetty osittaiskierteisiä ruuveja, mutta työmaatyöskentelyä helpottaisi siirtyminen täyskierteisten ruuvien käyttöön. Tämä mm. vähentäisi käytettävien ruuvinimikkeiden määrää. Tämän diplomityön tarkoituksena on selvittää laskemalla ja Ftower -laskentaohjelmaa käyttämällä, onko siirtyminen täyskierteisten ruuvien käyttöön mahdollista. Tarkastelua suoritetaan lisäksi myös FEM -analyysilla. Lisäksi tarkastellaan myös muita voimansiirtolinjojen ruuviliitoksiin liittyviä ongelmia, ja pyritään löytämään näihin ratkaisuehdotuksia.
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Ascaris suum allergenic components (PIII) separated by gel filtration chromatography of an adult worm extract were used to immunize BALB/c mice. Popliteal lymph node cells taken from the immunized animals were fused with SP2/O myeloma cells using polyethylene glycol (MW 1450) as fusogen. The hybridomas were cultured in HAT-containing medium and cloned at limiting dilutions. Supernatants from the growing hybrids were screened by ELISA using plates coated with PIII or the A. suum crude extract. The monoclonal antibody obtained, named MAC-3 (mouse anti-A. suum allergenic component), is an IgG1 kappa mouse immunoglobulin that specifically recognizes a 29,000 molecular weight protein (called allergenic protein) with an affinity constant of 1.7 x 10(9) M-1. The A. suum components recognized by MAC-3 induce specific IgE antibody production in immunized BALB/c mice. Ascitic fluid induced in Swiss mice by injecting ip the hybridoma cells and incomplete Freund's adjuvant was purified by affinity chromatography using a protein A-Sepharose column. The purified monoclonal antibody was then coupled to activated Sepharose beads in order to isolate the A. suum allergenic component from the whole extract by affinity chromatography.
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Rats infected with the helminth Capillaria hepatica regularly develop septal fibrosis of the liver similar to that induced by repeated ip injections of pig serum. Fibrosis starts when the focal parasitic lesions begin to show signs of resorption, thus suggesting an immunologically mediated pathogenesis of this fibrosis. To explore this possibility, the development of C. hepatica-related hepatic fibrosis was observed in rats exposed to worm antigens from the first neonatal day onward. Wistar rats (150 g) were either injected ip with an extract of C. hepatica eggs (protein concentration: 1 mg/ml) or received immature eggs by gavage from the first neonatal day until adult life and were then infected with 500 embryonated eggs. Changes were monitored on the basis of serum levels of anti-worm antibodies and hepatic histopathology. Rats submitted to immunological oral tolerance markedly suppressed C. hepatica-related serum antibodies and septal fibrosis of the liver when infected with the helminth later on. Tolerance trials with ip injections of worm antigens gave essentially negative results. The partial suppression of septal fibrosis of the liver after the induction of immunological tolerance to C. hepatica antigens in rats indicates an immunological basis for the fibrosis and emphasizes the importance of immunological factors in the pathogenesis of hepatic fibrosis.
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Kylmälaitekoneikot ovat kylmäkomponentteja sisältäviä rakenteita, joiden avulla toteutetaan suurten tilojen, kuten elintarvikemyymälöiden sisäilman jäähdytys. Lisäksi koneikkojen avulla jäähdytetään matalampiin lämpötiloihin pienempiä kylmähuoneita. Osa koneikoista ottaa talteen kylmäprosessissa syntyvän lämmön, jota hyödynnetään tilojen lämmityksessä. Tämän diplomityön tavoitteena oli suunnitella ja mitoittaa kahdeksalle eri kylmälaitekoneikolle entistä kustannustehokkaammat runkorakenteet, jotka ovat niin kestäviä, että koneikkoja on mahdollista pinota tilan säästämiseksi kolme päällekkäin. Lisäksi runkorakenteilta vaadittiin helppoa kuljetettavuutta, hyviä kiinnitysominaisuuksia ja korroosionkestävyyttä. Aluksi työssä selvitettiin runkorakenteisiin kohdistuvat vaatimukset, jonka jälkeen materiaalin valinta tehtiin materiaaliin kohdistuvien vaatimusten perusteella. Rakenteiden palkit mitoitettiin tarvittavan taivutusvastuksen ja kiepahduksen mukaan. Pilarit puolestaan mitoitettiin nurjahduksen ja kaksiaksiaalisen taivutustilan perusteella. Tämän jälkeen mitoitettiin eri sauvojen väliset hitsi- ja ruuviliitokset siten, että rakenne hajoaa ylikuormitustilanteessa mahdollisimman turvallisesti. Työssä tehdyt laskelmat varmennettiin elementtimenetelmän avulla ja lopullisille rakenteille tehtiin elementtimenetelmällä vielä ominaistaajuusanalyysejä. Lopuksi työssä suunniteltiin runkorakenteille sopiva korroosionsuojaus.
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Maatalouden lietelannasta saatavien ravinteiden talteenotto ja kierrätys ovat viime aikoina nousseet yhä tärkeämmäksi tavoitteeksi. Ravinteiden tehokas kierrätystapa saadaan ai-kaiseksi käsittelemällä lietelantaa. Lannan käsittelyketjuja on monenlaisia; tässä työssä naudan lannan käsittelyketju muodostuu separoinnista ja mädätyksestä. Tämän diplomityön tarkoituksena oli selvittää naudan lannan mekaanisen separoinnin ja logistiikan kannattavuus märkämädätys- ja kuivamädätyskäsittelyketjussa. Käsittelyketju-jen kannattavuus tai kannattamattomuus on esitetty eri skenaarioissa muodostettujen kus-tannuslaskentojen perusteella. Skenaarioiden kustannuslaskelmat ovat toisiinsa verratta-vissa, jolloin ne voidaan asettaa niin ikään paremmuusjärjestykseen. Viides skenaario ei ole suoraan verrattavissa muihin skenaarioihin, koska siinä lannankäsittelyketjua on tar-kasteltu eri näkökulmasta, keskittämällä suurimmalle maatilalle. Mekaanisista separaattoreista tarkasteltiin työssä ruuvipuristinta, dekantterilinkoa ja ul-koistettua separointipalvelua. Lannan logistiikkakustannuksissa huomioitiin lannan kulje-tusta traktori- ja säiliöautolla tai traktorilla. Separoinnin kustannus liitettiin osaksi logis-tiikkakustannusta. Työn tuloksien perusteella voidaan todeta dekantterilingon separointi-kustannuksen olevan taloudellisesti kannattamattomin johtuen pienestä lantakapasiteetista ja separaattorin korkeasta investointihinnasta. Ravinteiden osalta linko osoittautui tehok-kaimmaksi menetelmäksi erottamaan ravinteet eri jakeisiin. Lannan käsittely separointipalvelulla oli edullisin skenaario, jonka vuosittaiseksi kustan-nukseksi saatiin säiliö- ja kuorma-autolla lantaa kuljetettaessa 58 700 € ja traktorilla kul-jetettaessa 60 400 €. Kallein lannan käsittely oli dekantterilingolla, jonka vuosittaiseksi kustannukseksi saatiin lantaa säiliö- ja kuorma-autolla kuljetettaessa 121 000 € ja trakto-rilla kuljetettaessa 123 300 €. Lannan separointi maatilalla osoittautui kannattavammaksi kuin käsittelemättömän lietteen kuljetus biokaasulaitokselle.
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Leber's hereditary optic neuropathy (LHON) is a maternally inherited form of retinal ganglion cell degeneration leading to optic atrophy in young adults. Several mutations in different genes can cause LHON (heterogeneity). The ND6 gene is one of the mitochondrial genes that encodes subunit 6 of complex I of the respiratory chain. This gene is a hot spot gene. Fourteen Persian LHON patients were analyzed with single-strand conformational polymorphism and DNA sequencing techniques. None of these patients had four primary mutations, G3460A, G11788A, T14484C, and G14459A, related to this disease. We identified twelve nucleotide substitutions, G13702C, T13879C, T14110C, C14167T, G14199T, A14233G, G14272C, A14290G, G14365C, G14368C, T14766C, and T14798C. Eleven of twelve nucleotide substitutions had already been reported as polymorphism. One of the nucleotide substitutions (A14290G) has not been reported. The A14290G nucleotide substitution does not change its amino acid (glutamic acid). We looked for base conservation using DNA star software (MEGALIGN program) as a criterion for pathogenic or nonpathogenic nucleotide substitution in A14290G. The results of ND6 gene alignment in humans and in other species (mouse, cow, elegans worm, and Neurospora crassa mold) revealed that the 14290th base was not conserved. Fifty normal controls were also investigated for this polymorphism in the Iranian population and two had A14290G polymorphism (4%). This study provides evidence that the mtDNA A14290G allele is a new nonpathogenic polymorphism. We suggest follow-up studies regarding this polymorphism in different populations.
Resumo:
The effects of H2O2 were evaluated in the estuarine worm Laeonereis acuta (Polychaeta, Nereididae) collected at the Patos Lagoon estuary (Southern Brazil) and maintained in the laboratory under controlled salinity (10 psu diluted seawater) and temperature (20°C). The worms were exposed to H2O2 (10 and 50 µM) for 4, 7, and 10 days and the following variables were determined: oxygen consumption, catalase (CAT) and glutathione peroxidase activity in both the supernatant and pellet fractions of whole body homogenates. The concentrations of non-protein sulfhydryl and lipid peroxides (LPO) were also measured. The oxygen consumption response was biphasic, decreasing after 4 days and increasing after 7 and 10 days of exposure to 50 µM H2O2 (P < 0.05). At the same H2O2 concentration, CAT activity was lower (P < 0.05) in the pellet fraction of worms exposed for 10 days compared to control. Non-protein sulfhydryl concentration and glutathione peroxidase activity were not affected by H2O2 exposure. After 10 days, LPO levels were higher (P < 0.05) in worms exposed to 50 µM H2O2 compared to control. The reduction in the antioxidant defense was paralleled by oxidative stress as indicated by higher LPO values (441% compared to control). The reduction of CAT activity in the pellet fraction may be related to protein oxidation. These results, taken together with previous findings, suggest that the worms were not able to cope with this H2O2 concentration.
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Permanent bilateral occlusion of the common carotid arteries (2VO) in the rat has been established as a valid experimental model to investigate the effects of chronic cerebral hypoperfusion on cognitive function and neurodegenerative processes. Our aim was to compare the cognitive and morphological outcomes following the standard 2VO procedure, in which there is concomitant artery ligation, with those of a modified protocol, with a 1-week interval between artery occlusions to avoid an abrupt reduction of cerebral blood flow, as assessed by animal performance in the water maze and damage extension to the hippocampus and striatum. Male Wistar rats (N = 47) aged 3 months were subjected to chronic hypoperfusion by permanent bilateral ligation of the common carotid arteries using either the standard or the modified protocol, with the right carotid being the first to be occluded. Three months after the surgical procedure, rat performance in the water maze was assessed to investigate long-term effects on spatial learning and memory and their brains were processed in order to estimate hippocampal volume and striatal area. Both groups of hypoperfused rats showed deficits in reference (F(8,172) = 7.0951, P < 0.00001) and working spatial memory [2nd (F(2,44) = 7.6884, P < 0.001), 3rd (F(2,44) = 21.481, P < 0.00001) and 4th trials (F(2,44) = 28.620, P < 0.0001)]; however, no evidence of tissue atrophy was found in the brain structures studied. Despite similar behavioral and morphological outcomes, the rats submitted to the modified protocol showed a significant increase in survival rate, during the 3 months of the experiment (P < 0.02).
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The antischistosomal activity of the sulfated polysaccharide α-D-glucan (Glu.SO4) extracted from Ramalina celastri was evaluated after encapsulation into liposomes (Glu.SO4-LIPO) in Schistosoma mansoni-infected mice. The effect of treatment with Glu.SO4 and Glu.SO4-LIPO (10 mg/kg) on egg elimination, worm burden and hepatic granuloma formation was assessed using female albino Swiss mice, 35-40 days of age, weighing 25 ± 2 g, infected with 150 cercariae/animal (Biomphalaria glabrata, BH strain). Four groups (N = 10) were studied, two controls (empty liposomes and NaCl) and two treated groups (Glu.SO4-LIPO and Glu.SO4) using a single dose. Parasitological analysis revealed that Glu.SO4-LIPO was as efficient as Glu.SO4 in reducing egg elimination and worm burden. Treatment with free Glu.SO4 and Glu.SO4-LIPO induced a statistically significant reduction in the number of granulomas (62 and 63%, respectively). Lectin histochemistry showed that wheat germ agglutinin intensely stained the egg-granuloma system in all treated groups. On the other hand, peanut agglutinin stained cells in the control groups, but not in the treated groups. The present results suggest a correlation between the decreasing number of hepatic egg-granulomas and the glycosylation profile of the egg-granuloma system in animals treated with free Glu.SO4 or Glu.SO4-LIPO.
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Major histocompatibility complex class I chain-related A (MICA) is a highly polymorphic gene located within the MHC class I region of the human genome. Expressed as a cell surface glycoprotein, MICA modulates immune surveillance by binding to its cognate receptor on natural killer cells, NKG2D, and its genetic polymorphisms have been recently associated with susceptibility to some infectious diseases. We determined whether MICA polymorphisms were associated with the high rate of Schistosoma parasitic worm infection or severity of disease outcome in the Dongting Lake region of Hunan Province, China. Polymerase chain reaction-sequence specific priming (PCR-SSP) and sequencing-based typing (SBT) were applied for high-resolution allele typing of schistosomiasis cases (N = 103, age range = 36.2-80.5 years, 64 males and 39 females) and healthy controls (N = 141, age range = 28.6-73.3 years, 73 males and 68 females). Fourteen MICA alleles and five short-tandem repeat (STR) alleles were identified among the two populations. Three (MICA*012:01/02, MICA*017 and MICA*027) showed a higher frequency in healthy controls than in schistosomiasis patients, but the difference was not significantly correlated with susceptibility to S. japonicum infection (Pc > 0.05). In contrast, higher MICA*A5 allele frequency was significantly correlated with advanced liver fibrosis (Pc < 0.05). Furthermore, the distribution profile of MICA alleles in this Hunan Han population was significantly different from those published for Korean, Thai, American-Caucasian, and Afro-American populations (P < 0.01), but similar to other Han populations within China (P > 0.05). This study provides the initial evidence that MICA genetic polymorphisms may underlie the severity of liver fibrosis occurring in schistosomiasis patients from the Dongting Lake region.