Spelling suggestions: "subject:"veterinary""
41 |
Resposta inflamatória em éguas após inoculação intrauterina de três diferentes cepas de Escherichia coli / Endometritis in mares experimentally infected with three different strains of E. coliCamozzato, Giovani Casanova January 2014 (has links)
A endometrite é a causa mais importante de infertilidade em éguas falhadas e inflige grandes perdas na indústria de criação de equinos. Infecções uterinas bacterianas podem ocorrer em 25 % a 60 % das éguas estéreis e os agentes patogênicos mais frequentemente isolados são Streptococcus zooepidemicus e Escherichia coli. A endometrite causada por Streptococcus sp tem sido amplamente estudada, no entanto, pouco se sabe sobre a resposta endometrial da égua à E. Coli. Infecção focal induzida por E. coli foi associada com resposta inflamatória uterina menos exsudativa do que infecção por Streptococcus zooepidemicus. Em contrapartida, alguns estudos têm mostrado que as infecções uterinas por E. coli foram menos propensos a ter evidência citológica de inflamação. O objetivo deste estudo foi descrever a resposta inflamatória após a inoculação intra-uterina com três diferentes cepas de E. coli na égua. Nove éguas cíclicas , com idades entre 7 e 20 anos, foram selecionadas e seu estro detectado por palpação transretal e ultrassom. Somente éguas clinicamente normais com citologia negativa e bacteriologia foram utilizadas no experimento. Três diferentes cepas de E. coli obtidas a partir de: (UT) swab uterino de uma égua com endometrite, (VE) swab do vestíbulo de uma égua saudável e (FE) a partir de fezes de égua, foram utlizadas. Subsequentemente , as éguas foram submetidas a inoculação intrauterina com 3x109de bactérias de uma das três diferentes cepas E. coli. Todas as éguas foram desafiadas com as três cepas de E. coli de forma aleatória nos ciclos subseqüentes. Um dia após a infecção, foram realizados exame clínico do trato genital por espéculo, ultrassonografia, citologia endometrial e cultura bacteriológica. Estes procedimentos foram repetidos diariamente até ser diagnosticado cultura bacteriana e citologia negativa. Todas as éguas tiveram leve (<10/campo ) a grave (> 20/campo) neutrofilia endometrial 24h após a inoculação de E. coli. Em 25 das 27 infecções ( 92,6 %), sinais clínicos vaginais e líquido intra-uterino (LIU) foram detectados. Sinais clínicos vaginais graves como aspecto purulento e mucosa hiperêmica foram observadas em 17 infecções e 8 apresentaram sinais leves. Apenas 59,2% das infecções experimentais (16/27) foram positivas à cultura para E. coli 24h após a infecção. O tempo necessário para a eliminação das bactérias foi, em média de 2,8 dias ( ± 1,0 ). O tempo para o desaparecimento da inflamação (presença de leucócitos polimorfonucleares) foi em média 3,4 dias (±0.8). Em conclusão, a endometrite causada por E. coli provocou citologia positiva e a maioria das éguas desenvolveram sinais clínicos vaginais de endometrite e acúmulo de liquido intrauterino, não havendo diferença entre as cepas de E. coli. / Endometritis is the most important cause of infertility in barren mares and inflicts major losses on the equine breeding industry. Bacterial uterine infections occur in 25% to 60% of barren mares and the most frequently isolated pathogens are Streptococcus zooepidemicus and Escherichia coli. Endometritis caused by Streptococcus sp has been widely studied. However, little is known about the mare’s endometrial response to E. coli. Focal infection induced by E. coli was associated with less exudative uterine inflammatory response than by Streptococcus zooepidemicus. In contrast some studies have shown that uterine infections by E coli were less likely to have cytological evidence of inflammation. Treatment of mares with persistent uterine infections needs to be directed towards the underlying breakdown of the uterine defense and against the microbial agent. The aim of this study was to describe the inflammatory response after intrauterine inoculation with three different strains of E. coli in the mare. Nine cyclic mares aged between 7 and 20 years old were selected and their estrous detected by transrectal palpation and ultrasound. Only clinically normal mares with negative cytology and bacteriology were used. Three different strains of E. coli obtained from: (UT) uterine swab of a mare with endometritis, (VE) vestibular swab from a healthy mare and (MA) from mare manure, were used. Subsequently, the mares were submitted to intrauterine inoculation with 3x109 E. coli of one of the three different strains. All mares were challenged with each strain of E. coli in a randomized order in the subsequent different cycles. One day after infection, clinical examination of the genital tract by speculum, ultrasound, endometrial cytology and bacteriological cultures were performed. These procedures were repeated daily until negative culture and negative cytology were diagnosed. All mares had slight (<10/field) to severe (> 20/field) endometrial neutrophilia 24h after E. coli inoculation. In 25 of 27 infections (92.6%), vaginal clinical signs and intrauterine fluid (IUF) were detected. Severe vaginal signs with purulent aspect and hyperemic mucosa were observed in 17 infections and 8 presented mild signs. Only 59.2% of the examinations (16/27) were E. coli positive 24h after the infection. The time needed for elimination of bacteria in mares treated with leukocytes and mares of control group was in average 2.8 days and the cytology remained positive 3.4 days in average. In conclusion, E. coli endometritis provoke a positive cytology and most of the mares developed vaginal clinical signs of endometritis and IUF, with no difference among E. coli strains.
|
42 |
Estudo epidemiológico e genético dos vírus da imunodeficiência felina identificados no Estado de São Paulo /Lara, Valéria Maria. January 2004 (has links)
Orientador : João Pessoa Araújo Júnior / Resumo: O presente trabalho objetivou determinar a freqüência do vírus da imunodeficiência felina, correlacioná-la a dados epidemiológicos, identificar os diferentes sorotipos das amostras positivas e realizar a análise filogenética das mesmas. Para tanto, foram colhidas 519 amostras de sangue total de gatos domésticos oriundos de diferentes cidades do estado de São Paulo submetidas à técnica de PCR-nested para identificação do vírus. Dessas amostras, 81 (15,6%) apresentaram-se positivas ao teste, das quais 45 (55,5%) pertenciam a gatos com sinais clínicos de alguma enfermidade, sendo 21 fêmeas e 24 machos. Vinte e duas amostras (27,2%) foram provenientes de animais aparentemente normais, com duas fêmeas e 20 machos, e outras 14 (17,3%) a gatos sem histórico clínico definido, com três fêmeas e 11 machos. Foram submetidas ao seqüenciamento genético 50 (61,7%) amostras positivas. Entretanto, em somente 32 destas (64%) realizou-se a inferência filogenética. A análise genética foi baseada em um segmento do gene gag de 459 pb. As relações genealógicas foram realizadas através dos métodos da máxima parcimônia, da evolução mínima e de agrupamento de vizinhos. Os resultados obtidos revelaram uma ampla similaridade entre as três árvores construídas e em todas elas, as 32 amostras estudadas foram agrupadas dentro do mesmo sorotipo, que foi o sorotipo B. / Abstract: The present work aimed to determine the feline immunodeficiency virus frequency, to correlate it to epidemiologic data, to identify different FIV subtypes of positive samples and also to accomplish its phylogenetic analysis. For that, it was collected 519 blood samples of domestic cats from different cities of the São Paulo state, submitting them by PCR-nested for virus identification. Eighty one samples (15.6%) were positive to the test, which 45 (55.5%) of them were from animals with clinical signs of some illness. Those samples, 21 were from female and 24 from male cats. Twenty-two of the positive samples (27.2%) were from healthy cats (2 females and 20 males), and 14 of them (17.3%) from cats without clinical history (3 females and 11 males). Fifty positive samples (61.7%) were submitted to DNA sequencing, but only in 32 of them the phylogenetic inference was done. The genetic analysis was based on a segment of the gag gene with 459pb. The genealogical relationships were established through maximum parcimony, minimum evolution and neighbor-joining methods. The results revealed a wide similarity among the three built trees and, in all of them, the 32 studied samples were allocated inside of the same subtype, that was the subtype B. / Doutor
|
43 |
Diagnóstico de procesos patológicos en ungulados domésticos sacrificados en matadero en el Sureste de España.Sánchez Martínez, Pedro 20 September 2013 (has links)
La Inspección Veterinaria en los mataderos es necesaria para el control de los peligros asociados al consumo de carnes y para la vigilancia epidemiológica de las enfermedades que afectan a los animales de una explotación o región. El objeto de este estudio fue estimar la prevalencia de los procesos patológicos que motivan la declaración de no aptitud para consumo de canales de ungulados domésticos de cebo procedentes del sureste de España y clasificarlos en base a la fiabilidad de su diagnóstico en matadero, determinando en que procesos las lesiones macroscópicas detectadas mediante la inspección post mórtem son suficientes para comunicar con garantía la detección de una enfermedad o si precisan de diagnósticos laboratoriales externos y en cuales el examen histopatológico sería el método de elección. Para ello se procedió a clasificar los procesos patológicos que motivaron el dictamen de no aptitud para consumo de 137 bovinos, 973 ovinos, 337 caprinos y 545 porcinos de los 123.627, 1.846.435, 250.718 y 484.016 animales de cebo de cada especie, respectivamente, sacrificados durante diez años en un matadero del sureste de España. Además de las inspecciones ante y post mórtem y exámenes suplementarios realizados in situ, se tomaron muestras de tejidos de 200 de estos animales para la realización de exámenes histopatológicos. Se consideraron procesos con un nivel máximo de fiabilidad de diagnóstico en matadero aquellos que se diagnosticaron sin necesidad de recurrir a exámenes laboratoriales externos o éstos confirmaron el diagnóstico macroscópico en el 100 % de los casos. Fueron la tuberculosis bovina generalizada, la forma cutánea de mal rojo y síndrome dermatitis-nefropatía porcinos, la forma crónica de pseudotuberculosis ovina y la aguda de pleuroneumonía porcina, la enteropatía proliferativa porcina, las distomatosis hepatobiliares, la leucosis, las úlceras gástricas, la melanosis, la miositis eosinofílica y la urolitiasis. La cisticercosis bovina sólo se consideró cuando se detectan cisticercos viables. Se determinó que el examen histopatológico sería el método laboratorial de elección en procesos de etiología incierta como las miositis y las degeneraciones musculares, en neoplasias como la leucosis y para establecer el diagnóstico diferencial entre procesos que cursan con inflamaciones granulomatosas. De no realizarse podrían declararse un 3,70 % de falsos positivos de formas localizadas de tuberculosis bovina. De los resultados obtenidos se deduce que la prevalencia de los procesos patológicos diagnosticados está condicionada por los factores ambientales y los hábitos de consumo de esta área geográfica. La mayor tasa de muertes previas al sacrificio correspondió al ganado caprino (11,41 ‰0), con un incremento significativo (p<0,01) de bajas durante el transporte en los meses de invierno. Esta misma especie fue en la que se obtuvo un porcentaje más alto de canales no aptas por desnutrición (41,54 %). La prevalencia en el bovino de cebo de la tuberculosis generalizada y de la miositis eosinofílica fue de 2,59 ‰0 y 0.40 ‰0 respectivamente. Se observó una mayor incidencia de casos de mal rojo porcino en los meses de octubre-noviembre y mayo-junio obteniéndose una correlación significativa (p<0,01) entre el número de casos y el aumento de pluviometría. No se detectaron casos de fascioliasis en animales nacidos y criados en esta región peninsular. La anemia pronunciada fue la alteración fisiopatológica con mayor porcentaje (8,44 %) de canales de porcino no aptas para consumo debido a las hemorragias por úlceras gastroesofágicas y enteropatías. Finalmente, se propone un sistema de clasificación de los procesos patológicos en tres niveles 0, 1 y 2 basados en la fiabilidad de su diagnóstico para facilitar la comunicación de las enfermedades animales detectadas en matadero. / Diagnosis of pathological processes in slaughter-domestic ungulates in South-East of Spain Abattoir Veterinary Inspection is necessary not only for the control of hazards associated with the consumption of meat but also by epidemiological surveillance of diseases affecting animals in a certain region. The purpose of this investigation was to estimate the prevalence of pathological processes which motivate the condemnation of carcasses from animals reared in farms being located in the South-East of Spain. These processes have also been classified concerning the reliability of post mortem diagnosis at abattoir level in order to decide in which cases the macroscopic lesions are specifically enough to guarantee the diagnostic of a disorder or if an external laboratory diagnosis is necessary and to see in which the histopathological examination would be the proper method of choice. A technical survey was conducted in a red meat abattoir located in the South-East of Spain over a period of ten years (from January 2002 to December 2011). Pathological processes led to the condemnation of 137 cattle, 973 lambs, 337 kids and 545 pigs carcasses out of 123,627, 1,846,435, 250,718 and 484,016 animals slaughtered of each respective species were classified. After ante and post mortem examination, if a specific pathological process was suspected, additional tests were performed on site and also tissue samples from 200 of these animals were collected for histopathological examination. The pathological processes diagnosed without resorting to external laboratory tests agree definetily to the macroscopic diagnosis in 100 % of cases (maximum level of diagnostic reliability in abattoir) that were: generalized bovine tuberculosis, skin lesions in swine erysipelas, porcine dermatitis-nephropathy syndrome, chronic pseudotuberculosis, acute porcine pleuropneumonia, porcine proliferative enteropathy, hepatobiliary distomatosis, leukosis, gastric ulcers, melanosis, eosinophilic myositis and urolithiasis. As a fact of bovine cysticercosis post-mortem inspection is enough only when viable cysticerci are detected. The histopathological examination would be the method of choice to establish the differential diagnosis of pathological processes showing granulomatous inflammations such as tuberculosis and granulomatous pneumonia in small ruminants, uncertain etiology processes such as myositis and muscle degeneration and neoplastic processes as leukosis. If the histopathological diagnosis was not performed a 3.70 % of false positives of bovine tuberculosis would be declared. The final results show that the climatic factors and social conditions in this geographic area are influencing the animal production systems, impacting on the prevalence of the diagnosed pathological processes. The higher rates of pre-slaughter deaths were observed in kids (11.41 ‰0) with a statistically significant (p<0.01) increase in transport during the winter months. In the same species the higher percentage of carcass condemnation was malnutrition (41.54 %). The prevalence in cattle of generalized tuberculosis and eosinophilic myositis was 2.59 ‰0 and 0.40 ‰0, respectively. A higher incidence of swine erysipelas in the months of October-November and May-June was observed with a statistically significant correlation (p<0.01) between the number cases and the increase of the pluviometry. No cases of fascioliasis were detected in the animals that were born on farms in this region. The most important pathophysiological alteration of carcasses swine was anemia (8.44 %) due to gastroesophageal ulcers and hemorraghic enteropathy. Finally, we put forward a classification system into three levels (0, 1 and 2) for the declaration of the pathological processes based on the reliability of diagnosis in abattoir, in order to facilitate the official communication of animal diseases detected by meat inspectors.
|
44 |
Valores hematológicos de la tortuga motelo (Geochelone denticulata), mantenidos en cautiverio en la ciudad de Iquitos-PerúCabrera Pérez, Miguel Angel January 2008 (has links)
No description available.
|
45 |
Effect of antioxidant supplementation on pig and horse gamete storageGiaretta, Elisa <1985> 24 April 2015 (has links)
According to recent studies, antioxidant supplementation on gamete processing and/or storage solutions improvesgamete quality parameters, after cooling or storage at sub zero temperature. The aim of the present study was to investigate the effects of antioxidant supplementation on pig and horse gamete storage.
The first study aimed to determine the effects of resveratrol (RESV) on the apoptotic status of porcine oocytes vitrified by Cryotop method, evaluating phosphatidylserine (PS) exteriorization and caspases activation. RESV(2µM) was added during: IVM (A); 2 h post-warming incubation (B); vitrification/warming and 2 h post-warming incubation (C); all previous phases (D). The obtained data demonstrate that RESV supplementation in the various steps of IVM and vitrification/warming procedure can modulate the apoptotic process, improving the resistance of porcine oocytes to cryopreservation-induced damage.
In the second work different concentrations of RESV (10, 20, 40, and 80µM) were added during liquid storage of stallion sperm for 24 hours at either 10°C or 4°C, under anaerobic conditions. Our findings demonstrate that RESV supplementation does not enhance sperm quality of stallion semen after 24 hours of storage. Moreover, the highest RESV concentrations tested (40 and 80µM) could damage sperm functional status, probably acting as pro-oxidant.
Finally, in the third work other two antioxidants, ascorbic acid (AA) (100 µM) and glutathione (GSH) (5mM) were added on boar freezing and/or thawing solutions. In our study different sperm parameters were evaluated before freezing and at 30 and 240 minutes after thawing. Our results showed that GSH and AA significantly improved boar sperm cryotolerance, especially when supplemented together to both freezing and thawing media. This improvement was observed in sperm viability and acrosome integrity, sperm motility, and nucleoprotein structure. Although ROS levels were not much increased by freeze-thawing procedures, the addition of GSH and AA to both freezing and thawing extenders significantly decreased intracellular peroxide levels.
|
46 |
Studio, mediante applicazioni biotecnologiche, di tre diversi modelli spontanei o indotti di patologie del sistema nervosoTurba, Maria Elena <1978> 21 May 2007 (has links)
No description available.
|
47 |
Validación de la enteroscopia de doble balón (EDB) en el perro (Canis lupus familiaris, L).Sarriá Cabrera, Ricardo 25 October 2013 (has links)
Tesis por compendio de publicaciones / BJETIVOS 1. Evaluar de forma detallada la morfología del intestino delgado en el perro y su relación con las condiciones de seguridad necesarias para la aplicación de la EDB (artículo 1). 2. Contribuir a la caracterización de la histología normal del intestino del perro mediante la cuantificación sistemática del grosor de sus túnicas (artículo 2). 3. Evaluar la eficacia y seguridad de la técnica de EDB en el perro tanto vía oral (artículo 3) como vía anal (artículo 4). METODOLOGÍA El diseño de la tesis se fundamenta en 2 fases experimentales, la primera en cadáveres de perro, y la segunda in vivo. Un total de 55 cadáveres de perro fueron empleados para el estudio anatómico/morfométrico del intestino delgado (objetivo 1, artículo 1). De esos 55 animales, 41 también fueron utilizados para el estudio histológico/morfométrico del intestino delgado (objetivo 2, artículo 2). Para la fase experimental in vivo, se emplearon un total de 21 perros sin historial de enfermedad digestiva. Las exploraciones enteroscópicas se realizaron con un enteroscopio terapéutico de doble balón (EN-450T5, Fujinón®) tanto por vía oral (objetivo 3, artículo 3), como anal (objetivo 4, artículo 4). Los dos balones del equipo son inflados y desinflados alternativamente para permitir el progreso del endoscopio (maniobra de empuje) o plegamiento del intestino detrás de los balones (maniobra de rectificación). CONCLUSIONES 1. El estudio anatómico del intestino delgado ha permitido validar la especie canina como adecuada para la EDB siempre que se respeten las posibles limitaciones impuestas por el diámetro del lumen intestinal en animales de pequeño tamaño. La longitud del antebrazo fue el parámetro corporal con mayor asociación con el diámetro del intestino, y por ende el mejor estimador del tamaño mínimo requerido para la EDB en el perro. 2. Los resultados obtenidos sobre el rango de grosor normal de las diferentes túnicas a lo largo de todo el intestino delgado del perro constituyen la primera referencia publicada de estas características, con lo que ello puede suponer para el diagnóstico de patologías del intestino delgado a partir de de biopsias endoscópicas, ultrasonidos, muestras obtenidas por laparoscopia o postmortem. El sexo debe ser tenido en cuenta como fuente de variación del grosor de las túnicas intestinales. 3. Se ha demostrado que la EDB tanto por vía oral como anal es factible y segura en la especie canina. Los resultados aportados sobre la dinámica de exploración son importantes pues aportan valores de referencia para el empleo futuro de la EDB con fines diagnósticos o de tratamiento de enfermedades en porciones profundas del intestino delgado. 4. La exploración completa del intestino delgado del perro mediante EDB no ha sido posible ni por vía oral ni anal. Sin embargo, dado el interés que ello puede tener en el diagnóstico de algunas enfermedades del intestino delgado, serían necesarios nuevos estudios en los que se plantee la combinación de ambas vías. / OBJETIVES 1. To study in detail the morphology of the small intestine in the dog so as to evaluate whether it accomplishes the security conditions required for the double balloon enteroscopy. 2. To contribute to characterize the normal histology of the dog´s small intestine by quantifying the thickness of its layers. 3. To characterize the efficiency and safety of the double balloon enteroscopy in the dog by both the oral and anal approaches. METHODS This work was carried out in two experimental phases. The first one in cadavers and the second in vivo. 55 dog cadavers were used for anatomical (morphometric) study (objective 1, article 1), while 41 of them were used for histological (morphometric) study of the small intestine (objective 2, article 2). For the in vivo experimental phase (DBE), 21 dogs without history of digestive diseases were used. DBE were carried out with a therapeutic enteroscope (EN-450T5, Fujinon®) either by the oral (objective 3, article 3) and the anal approaches (objective 4, article 4). Two balloons are inflated and deflated in an alternating sequence to allow the endoscope to progress (pushing phase) or fold the explored intestine behind the balloons (pulling phase). CONCLUSIONS 1. Validation of the dog as a candidate for DBE has been obtained after a thorough anatomical study of the small intestine. However, when planning DBE caution should be taken in small dogs due to potential limitations imposed by the width of the intestine. The length of the forearm showed the highest association with the diameter of the intestine so that it is the best body parameter to define the minimum body size necessary for a secure DBE in the dog. 2. The results for the thicknesses of the different layers of the small intestine given in this study are a novelty and might serve to assist the diagnosis of enteropathies by endoscopic biopsies, ultrasounds, laparoscopy and postmortem sampling. The sex should be considered as a major source of variation in intestinal thickness in the dog. 3. It has been demonstrated that both the oral and anal DBE is feasible and safe in the dog. The results for the exploration dynamics of the procedure might serve as reference values for future diagnosis and treatment of diseases in deep portions of the small intestine. 4. The complete exploration of the small intestine by DBE has not been achieved yet in the dog. Further studies with a combination of the oral and anal approaches might facilitate this goal, which could be useful for a accurate diagnosis of some enteropathies.
|
48 |
Angiogenesis and angioregression gene expression analyses in swine corpus luteumDe Andrea Ribeiro, Luciana <1971> 28 May 2007 (has links)
The corpus luteum (CL) lifespan is characterized by a rapid growth,
differentiation and controlled regression of the luteal tissue, accompanied by
an intense angiogenesis and angioregression. Indeed, the CL is one of the
most highly vascularised tissue in the body with a proliferation rate of the
endothelial cells 4- to 20-fold more intense than in some of the most
malignant human tumours. This angiogenic process should be rigorously
controlled to allow the repeated opportunities of fertilization. After a first
period of rapid growth, the tissue becomes stably organized and prepares
itself to switch to the phenotype required for its next apoptotic regression. In
pregnant swine, the lifespan of the CLs must be extended to support
embryonic and foetal development and vascularisation is necessary for the
maintenance of luteal function. Among the molecules involved in the
angiogenesis, Vascular Endothelial Growth Factor (VEGF) is the main
regulator, promoting endothelial cells proliferation, differentiation and survival
as well as vascular permeability and vessel lumen formation. During vascular
invasion and apoptosis process, the remodelling of the extracellular matrix is
essential for the correct evolution of the CL, particularly by the action of
specific class of proteolytic enzymes known as matrix metalloproteinases
(MMPs). Another important factor that plays a role in the processes of
angiogenesis and angioregression during the CL formation and luteolysis is the isopeptide Endothelin-1 (ET-1), which is well-known to be a potent
vasoconstrictor and mitogen for endothelial cells. The goal of the present
thesis was to study the role and regulation of vascularisation in an adult
vascular bed. For this purpose, using a precisely controlled in vivo model of
swine CL development and regression, we determined the levels of
expression of the members of VEGF system (VEGF total and specific
isoforms; VEGF receptor-1, VEGFR-1; VEGF receptor-2, VEGFR-2) and ET-
1 system (ET-1; endothelin converting enzyme-1, ECE-1; endothelin receptor
type A, ET-A) as well as the activity of the Ca++/Mg++-dependent
endonucleases and gelatinases (MMP-2 and MMP-9). Three experiments
were conducted to reach such objectives in CLs isolated from ovaries of
cyclic, pregnant or fasted gilts.
In the Experiment I, we evaluated the influence of acute fasting on VEGF
production and VEGF, VEGFR-2, ET-1, ECE-1 and ET-A mRNA expressions
in CLs collected on day 6 after ovulation (midluteal phase). The results
indicated a down-regulation of VEGF, VEGFR-2, ET-1 and ECE-1 mRNA
expression, although no change was observed for VEGF protein.
Furthermore, we observed that fasting stimulated steroidogenesis by luteal
cells. On the basis of the main effects of VEGF (stimulation of vessel growth
and endothelial permeability) and ET-1 (stimulation of endothelial cell
proliferation and vasoconstriction, as well as VEGF stimulation), we
concluded that feed restriction possibly inhibited luteal vessel development.
This could be, at least in part, compensated by a decrease of vasal tone due
to a diminution of ET-1, thus ensuring an adequate blood flow and the
production of steroids by the luteal cells.
In the Experiment II, we investigated the relationship between VEGF,
gelatinases and Ca++/Mg++-dependent endonucleases activities with the
functional CL stage throughout the oestrous cycle and at pregnancy. The
results demonstrated differential patterns of expression of those molecules in
correspondence to the different phases of the oestrous cycle. Immediately
after ovulation, VEGF mRNA/protein levels and MMP-9 activity are maximal.
On days 5–14 after ovulation, VEGF expression and MMP-2 and -9 activities
are at basal levels, while Ca++/Mg++-dependent endonuclease levels
increased significantly in relation to day 1. Only at luteolysis (day 17),
Ca++/Mg++-dependent endonuclease and MMP-2 spontaneous activity
increased significantly. At pregnancy, high levels of MMP-9 and VEGF were
observed. These results suggested that during the very early luteal phase,
high MMPs activities coupled with high VEGF levels drive the tissue to an
angiogenic phenotype, allowing CL growth under LH (Luteinising Hormone)
stimulus, while during the late luteal phase, low VEGF and elevate MMPs
levels may play a role in the apoptotic tissue and extracellular matrix
remodelling during structural luteolysis.
In the Experiment III, we described the expression patterns of all distinct
VEGF isoforms throughout the oestrous cycle. Furthermore, the mRNA expression and protein levels of both VEGF receptors were also evaluated.
Four novel VEGF isoforms (VEGF144, VEGF147, VEGF182, and
VEGF164b) were found for the first time in swine and the seven identified
isoforms presented four different patterns of expression. All isoforms showed
their highest mRNA levels in newly formed CLs (day 1), followed by a
decrease during mid-late luteal phase (days 10–17), except for VEGF182,
VEGF188 and VEGF144 that showed a differential regulation during late
luteal phase (day 14) or at luteolysis (day 17). VEGF protein levels paralleled
the most expressed and secreted VEGF120 and VEGF164 isoforms. The
VEGF receptors mRNAs showed a different pattern of expression in relation
to their ligands, increasing between day 1 and 3 and gradually decreasing
during the mid-late luteal phase. The differential regulation of some VEGF
isoforms principally during the late luteal phase and luteolysis suggested a
specific role of VEGF during tissue remodelling process that occurs either for
CL maintenance in case of pregnancy or for noncapillary vessel development
essential for tissue removal during structural luteolysis.
In summary, our findings allow us to determine relationships among factors
involved in the angiogenesis and angioregression mechanisms that take
place during the formation and regression of the CL. Thus, CL provides a
very interesting model for studying such factors in different fields of the basic
research.
|
49 |
Il 2-metossiestradiolo: un potenziale inibitore fisiologico dell'angiogenesi follicolareSantini, Sujen Eleonora <1979> 16 May 2008 (has links)
No description available.
|
50 |
La determinazione del cortisolo nel pelo per la valutazione del benessere animaleViggiani, Roberta <1974> 16 May 2008 (has links)
La definizione di “benessere animale” e le modalità di determinazione di tale parametro
sono ancora ampiamente dibattute. C’è, però, una generale concordanza sul fatto che una
condizione di malessere dia origine a variazioni fisiologiche e comportamentali che possono essere
rilevate e misurate. Tra i parametri endocrini, il più studiato è, senza dubbio, il cortisolo, in quanto
connesso con l’attivazione dell’asse ipotalamico-pituitario-surrenale in condizioni di stress e quindi
ritenuto indicatore ideale di benessere, benché debba essere utilizzato con cautela in quanto un
aumento dei livelli di questo ormone non si verifica con ogni tipo di stressor. Inoltre, si deve
considerare che la raccolta del campione per effettuare le analisi, spesso implica il confinamento ed
il contenimento degli animali e può essere, quindi, essa stessa un fattore stressante andando ad
alterare i risultati.
Alla luce delle suddette conoscenze gli obiettivi scientifici di questa ricerca, condotta sul
gatto e sul cane, sono stati innanzitutto validare il metodo di dosaggio di cortisolo dal pelo e
stabilire se tale dosaggio può rappresentare un indicatore, non invasivo, di benessere dell’animale
(indice di “stress cronico”). In seguito, abbiamo voluto individuare i fattori di stress psico-sociale in
gatti che vivono in gattile, in condizioni di alta densità, analizzando i correlati comportamentali
ed ormonali dello stress e del benessere in questa condizione socio-ecologica, ricercando, in
particolare, l’evidenza ormonale di uno stato di stress prolungato e la messa in atto di strategie
comportamentali di contenimento dello stesso e il ruolo della marcatura visivo-feromonale,
inoltre abbiamo effettuato un confronto tra oasi feline di diversa estensione spaziale per valutare
come varia lo stress in rapporto allo spazio disponibile.
Invece, nel cane abbiamo voluto evidenziare eventuali differenze dei livelli ormonali tra cani
di proprietà e cani di canili, tra cani ospitati in diversi canili e tra cani che vivono in diverse realtà
familiari; abbiamo voluto valutare gli effetti di alcuni arricchimenti sui cani di canile ed, infine,
abbiamo analizzato cani sottoposti a specifici programmi si addestramento.
Il primo importante ed originale risultato raggiunto, che risponde al primo obiettivo della
ricerca, è stato la validazione del dosaggio radioimmunologico di cortisolo in campioni di pelo.
Questo risultato, a nostro avviso, apre una nuova finestra sul campo della diagnostica
endocrinologica metabolica. Attualmente, infatti, il monitoraggio ormonale viene effettuato su
campioni ematici la cui raccolta prevede un elevato stress (stress da prelievo) per l’animale data
l'invasività dell'operazione che modifica l’attività di ipotalamo-ipofisi-surrene e, dunque, provoca
repentine alterazioni delle concentrazioni ormonali. Questa metodica offre, quindi, il vantaggio
dell’estrema semplicità di raccolta del campione e, in più, il bassissimo costo del materiale
utilizzato.
Dalle ricerche condotte sui gatti di gattile sono scaturite preziose indicazioni per future
indagini sullo stress e sul comportamento sociale felino. I risultati dell’analisi congiunta del
comportamento e delle concentrazioni ormonali hanno evidenziato che la disponibilità di
postazioni di marcatura visivo-feromonale ha un effetto positivo sia sugli indicatori
comportamentali, sia su quelli ormonali di stress.
I risultati dell’analisi delle concentrazioni di cortisolo, derivanti dal confronto tra sette oasi
feline di diversa estensione spaziale hanno permesso di evidenziare un aumento dei livelli
dell’ormone inversamente proporzionale allo spazio disponibile.
Lo spazio disponibile, però, non è l’unico fattore da prendere in considerazione al fine di
assicurare il benessere dell’animale infatti, nelle colonie che presentavano instabilità sociale e
variabilità territoriale il cortisolo aveva valori elevati nonostante le notevoli disponibilità di spazio.
Infine, si è potuto costatare come anche lo stare appartati, aumenti proporzionalmente con
l’aumentare dello spazio. Questo comportamento risulta essere molto importante in quanto mitiga lo
stress ed è da prendere in considerazione nell’allestimento di colonie feline. Infatti, nelle colonie di
dimensioni ridotte dove lo stress è già alto, l’impossibilità dei soggetti di appartarsi può contribuire
a peggiorare la situazione; ecco perché si dovrebbero creare luoghi artificiali per fornire ai gatti la
possibilità di appartarsi, magari sfruttando gli spazi sopraelevati (tetti, alberi, ecc.).
Per quanto riguarda il confronto tra cani di proprietà e cani di canile non sono state
evidenziate differenze significative nei livelli di cortisolo nel pelo mentre abbiamo rilevato che
quest’ultimi sono influenzati dalla disponibilità di spazio: infatti sia i cani di proprietà che vivevano
in giardino, sia i cani dei canili che praticavano lo sgambamento presentavano livelli di cortisolo nel
pelo più bassi rispetto, rispettivamente, ai cani di proprietà che vivevano in appartamento o
appartamento/giardino e a quelli di canile che non praticavano lo sgambamento.
L’arricchimento ambientale fornito ai cani di canile ha esercitato un’influenza positiva
riducendo i livelli di cortisolo e migliorando la docilità dei soggetti, favorendone un’eventuale
adozione.
Si è inoltre messo in luce che i programmi di addestramento, eseguiti con tecniche “gentili”,
non comportano situazioni stressanti per l’animale e aiutano i cani ad esprimere doti di equilibrio
che rimarrebbero altrimenti celate dagli aspetti più istintivi del carattere. D’altra parte, l’impegno
agonistico prima di una competizione e il livello di addestramento raggiunto dai cani, influenzano le
concentrazioni di cortisolo a riposo e durante l’esercizio fisico.
Questi risultati possono sicuramente dare utili suggerimenti per la gestione e la cura di
gatti e cani al fine di migliorarne le condizioni di benessere.
|
Page generated in 0.1106 seconds