No description available.

No description available.

High lipid : low dextrose (HL:LD) parenteral admixture (PA) is high in polyunsaturated fatty acids (PUFA) that are sensitive to peroxidation. This study evaluated the antioxidative effect of vitamin E in both HL:LD PA and in obese cats given HL:LD PA. Natural d-α-tocopherol (Vital E-300) was added to HL:LD PA at seven concentrations (8, 12, 16, 24, 32, 48, or 64 IU/g of lipid). PA were exposed to fluorescent light for 24 hours at room temperature. Hydroperoxides were measured at baseline and 24 hours hang time. Significantly lower hydroperoxide concentrations were found with > 24 IU/g of lipid at baseline (P < 0.01). A higher d-α-tocopherol concentration was required (> 48 IU/g lipid) to lower hydroperoxides at 24 hours (P < 0.0001). HL:LD PA with 40 IU/g lipid/day d-α-tocopherol was delivered intravenously to obese cats (PA Toc⁺) over 48 hours. Control cats (PA Toc⁻) received HL:LD PA without a d-α-tocopherol supplementation. Oxidative status of cats was evaluated at baseline and 24, 48, and 96 hours. Cats in both groups exhibited an increase in MDA concentration (time effect; P < 0.0001). WBC-tGSH and WBC-GPx did not change in either group of cats. RBC-tGSH and RBC-GPx changed over time (time effects; P = 0.0005; P = 0.0016, respectively) with the PA Toc⁺ cats exhibiting a higher RBC-tGSH concentration (treatment x time interaction; P = 0.012). Serum α- and γ-tocopherol concentrations increased in PA Toc⁺ cats (treatment effect; P < 0.0001). These findings suggest that d-α-tocopherol significantly alters oxidative status in vivo. / Master of Science

Objective: To assess effects of bisection nephrotomy on renal function, size, and morphology in cats over a period of 12 weeks. Study Design: Controlled, randomized, blinded experiment. Sample Population: Ten adult female cats. Methods: Glomerular filtration rate (GFR), as determined by quantitative renal scintigraphy using 99mTc-DTPA, urinalysis, urine culture, and sonographic measurement of renal size were performed pre-operatively. A left or right nephrotomy (five randomly assigned cats in each group) was performed. Total and individual kidney GFRs were determined in each cat 2, 28 and 84 days post-operatively. Both kidneys were measured sonographically 28 and 86 days postoperatively and an ultrasound-guided biopsy of each kidney was obtained 86 days postoperatively. Results: No significant differences in mean GFR and kidney size of the operated versus un-operated kidneys were observed at any time period. Individual GFR and renal size of all except one of the cats remained within normal limits. Two additional cats had evidence of transient ureteral obstruction in the immediate post-operative period. No significant histologic abnormalities were observed in any biopsy. Conclusions: Bisection nephrotomy in normal cats did not adversely affect renal function or morphology over the three month post-operative period. Clinical Relevance: Bisection nephrotomy can be safely performed in normal feline kidneys without causing a significant deleterious effect on renal function. Studies in animals with pre-existing renal insufficiency are needed to insure no adverse effects would occur in clinical cases where this surgical procedure is warranted. / Master of Science

Hyperthyroidism is the most common feline endocrinopathy. 131I is the treatment of choice, and over 50,000 cats have been treated using an empirical fixed dose. Better treatment responses could be achieved by tailoring the dose based on the severity of disease. Scintigraphy is the best method to quantify the severity of the disease. Previously established scintigraphic quantitative methods, thyroid to salivary ratio (T:S ratio) and % dose uptake, are the most widely recognized measurements. Recently, the thyroid to background ratio (T:B ratio) has been proposed as an alternate method to assess function and predict 131I treatment response. The purpose of this study was to determine the best location of a background ROI, which should be reflective of blood pool activity. We also hypothesized that the T:B ratio using the determined background ROI would provide improved correlation to T4 when compared to T:S ratio and % dose uptake in hyperthyroid cats. Fifty-six hyperthyroid cats were enrolled. T4 was used as the standard measure of thyroid function and was obtained prior to thyroid scintigraphy and 131I therapy. Blood samples were collected at the time of scintigraphy and radioactivity within the sample was measured. The plasma radioactivity was compared to the background ROI count densities in 8 anatomic regions using linear regression analysis for 55 cats. One cat was excluded from the study because of an injection error during scintigraphy. T:B and T:S ratios, and % dose uptake on scintigraphy were then compared to serum T4 by linear regression analysis for 39 cats. Sixteen cats were excluded because of recent methimazole or Y/D diet use, or incomplete data. The heart ROI correlated best to plasma pertechnetate activity (r = 0.70). % dose uptake correlated best to serum T4 (r = 0.74), followed by T:S ratio (r = 0.66), followed by the T:B ratio using the heart ROI (r = 0.59). Placing an ROI over the heart is the best method of quantifying plasma radioactivity. T:B ratio using the heart ROI as the background is a good predictor T4 but percent dose uptake and T:S ratio proved to be better predictors of T4 than any of the T:B ratios. Therefore, our hypothesis was not supported. The T:B ratio may not provide the best scintigraphic measurement of thyroid function. Hence it is unlikely to accurately predict treatment response to 131I therapy. / Master of Science

Background: Hyperthyroid cats are predisposed to thrombus formation. The mechanism for thrombogenesis is currently unknown, but could be associated with altered hemostasis as seen in hyperthyroid humans. Objective: The purpose of this study was to evaluate markers of hemostasis in hyperthyroid cats compared to healthy cats, and in hyperthyroid cats before and after treatments with radioactive iodine (RIT). Methods: Twenty-five cats with hyperthyroidism and 13 healthy euthyroid cats > 8 years of age were studied. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, antithrombin (AT), D-dimers, thrombin-antithrombin complexes (TAT), von Willebrand Factor antigen (vWF:Ag), and activity of factors VIII and IX were measured. An echocardiogram was performed in all cats and healthy cats with abnormal echocardiograms were excluded. Measurements of hemostasis were evaluated again in 7 cats > 6 months after RIT and deemed to have restored euthyroid status. Results: There is a significant likelihood of being in hypercoagulable state based on hyperthyroid state (P = 0.019) and serum T4 level is significantly associated with predicating hypercoagulability (P = 0.043). Hyperthyroidism is associated with significantly higher median fibrinogen concentration (P < 0.0001), higher median AT activity (P < 0.0001), and higher median vWF:Ag level (P = 0.01) with all values decreasing significantly post-RIT. Fibrinogen and AT had a strong positive correlation with serum T4 value (r = 0.79; 95% CI 0.63 - 0.89 and r = 0.70; 95% CI 0.50 - 0.84, respectively). Presence of an abnormal echocardiogram in hyperthyroid cats was associated with a significantly higher median fibrinogen concentration (P = 0.03). Echocardiographic status did not have a significant impact on the remaining hemostatic markers in hyperthyroid cats. Conclusions: These results provide evidence of altered hemostasis and hypercoagulability in hyperthyroid cats that do not appear to be solely attributed to cardiac abnormalities. These differences of altered hemostasis resolved after radioiodine therapy, but further studies are warranted to determine if hypercoagulable state resolves. / Master of Science / In feline hyperthyroidism, there is a predisposition for thrombus formation. An alteration of hemostasis has been documented in hyperthyroid humans, but despite reports of thrombus formation in hyperthyroid cats, the underlying mechanism is currently unknown. Hyperthyroidism can lead to cardiac abnormalities that could possibly contribute thrombus formation, although thrombus formation has occurred in hyperthyroid cats without detected abnormalities. The goal of this study was to evaluate markers of hemostasis in hyperthyroid cats presenting for radioiodine therapy to evaluate for presence of hypercoagulability. Twenty-five hyperthyroid cats were evaluated with hemostasis panels and echocardiograms. The results were compared to a group of 13 healthy cats. Markers of hemostasis and echocardiograms in 7 hyperthyroid cats were also compared to results 6 months or greater post-radioiodine therapy. There was evidence of altered hemostasis and hypercoagulability in hyperthyroid cats. The alterations noted resolved after radioiodine therapy and do not appear to be solely attributed to cardiac abnormalities seen in hyperthyroid cats.

Gatos infectados naturalmente pelo vírus da imunodeficiência felina (FIV) desenvolvem uma síndrome semelhante à causada pela infecção pelo vírus da imunodeficiência humana (HIV), sendo a espécie felina um modelo promissor de estudo da infecção pelo HIV. Em humanos a nefropatia associada à infecção pelo HIV é uma causa comum e preocupante de complicação por resultar em insuficiência renal progressiva nos pacientes acometidos. Achados clínico-patológicos identificados em gatos naturalmente infectados pelo FIV também sugerem um envolvimento renal. Com o intuito de determinar a ocorrência de doença renal crônica (DRC) em gatos infectados pelo FIV e uma possível associação entre essas doenças, foi estudada uma população de 44 gatos, sendo 20 animais naturalmente infectados e 24 animais não-infectados, submetidos às mesmas condições higiênico-sanitárias, de dieta e quanto à exposição a agentes infecciosos. Os animais foram acompanhados durante um período de 18 meses, durante o qual foram realizadas dosagens periódicas de creatinina sérica e mensuração da relação proteína:creatinina urinária (RPC-U). A ocorrência de DRC em gatos infectados pelo FIV foi de 45%, maior em comparação aos 25% referentes ao grupo não-infectado, embora não tenha havido diferença estatisticamente significativa entre esses grupos. A proteinúria em pelo menos um momento foi observada em 60% dos gatos infectados pelo FIV e em 26,1% dos gatos não infectados (p= 0,037). Considerando proteinúria persistente como aquela observada em pelo menos 3 momentos consecutivos, os gatos infectados tiveram ocorrência de 30,8% em comparação a 6,7% referente ao grupo não infectado (p> 0,05). Houve associação entre o óbito e a DRC apenas nos gatos infectados (p= 0,02). Concluiu-se que, apesar de a ocorrência de doença renal crônica e de proteinúria não ter sido estatisticamente maior diante da infecção pelo FIV, a associação entre o óbito e a DRC nos animais infectados sugere que o FIV pode contribuir para o agravamento da DRC, levando a rápida deterioração do organismo e considerável diminuição da sobrevida. / Cats naturally infected with the feline immunodeficiency virus (FIV) develop a syndrome that share common characteristics with the human immunodeficiency virus (HIV) infection. For this reason, felines are considered a promising model for the study of HIV infection. HIV associated nephropathy is a common and concerning complication in human beings, resulting in progressive renal insufficiency. Likewise clinico-pathological findings in naturally infected cats suggest a renal involvement. To evaluate the occurrence of chronic kidney disease (CKD) in cats infected with FIV and to verify a possible association between both diseases, a population of 44 cats submitted to the same sanitary handling, diet and exposure to infectious agents was studied. Of these cats, 20 were naturally infected with FIV and 24 were free of FIV infection. Animals were periodically accompanied for a 18-month period through serum creatinine and urinary protein:creatinine ratio measures. The occurrence of CKD in cats infected with FIV was 45%, a value higher than the observed in non-infected cats (25%), but no statistical difference was found. Proteinuria in at least one moment of evaluation was observed in 60% of infected cats and in 26,1% of non-infected cats (p=0,037). Considering the criterion of persistent proteinuria as the observation of urinary protein excretion in at least 3 consecutive moments, infected cats exhibited occurrence of 30,8% compared with 6,7% in the non-infected group (p>0,05). It was observed an association between death and CKD only in the cats infected with FIV (p=0,02). In conclusion, despite occurrence of CKD and proteinuria have not been statistically higher in infected cats than in non-infected one, the association between death and CKD in FIV-infected cats suggests FIV may contribute for the worsening of CKD, resulting in a quicker organic dysfunction and marked reduction of survival.

Gatos infectados naturalmente pelo vírus da imunodeficiência felina (FIV) desenvolvem uma síndrome semelhante à causada pela infecção pelo vírus da imunodeficiência humana (HIV), sendo a espécie felina um modelo promissor de estudo da infecção pelo HIV. Em humanos a nefropatia associada à infecção pelo HIV é uma causa comum e preocupante de complicação por resultar em insuficiência renal progressiva nos pacientes acometidos. Achados clínico-patológicos identificados em gatos naturalmente infectados pelo FIV também sugerem um envolvimento renal. Com o intuito de determinar a ocorrência de doença renal crônica (DRC) em gatos infectados pelo FIV e uma possível associação entre essas doenças, foi estudada uma população de 44 gatos, sendo 20 animais naturalmente infectados e 24 animais não-infectados, submetidos às mesmas condições higiênico-sanitárias, de dieta e quanto à exposição a agentes infecciosos. Os animais foram acompanhados durante um período de 18 meses, durante o qual foram realizadas dosagens periódicas de creatinina sérica e mensuração da relação proteína:creatinina urinária (RPC-U). A ocorrência de DRC em gatos infectados pelo FIV foi de 45%, maior em comparação aos 25% referentes ao grupo não-infectado, embora não tenha havido diferença estatisticamente significativa entre esses grupos. A proteinúria em pelo menos um momento foi observada em 60% dos gatos infectados pelo FIV e em 26,1% dos gatos não infectados (p= 0,037). Considerando proteinúria persistente como aquela observada em pelo menos 3 momentos consecutivos, os gatos infectados tiveram ocorrência de 30,8% em comparação a 6,7% referente ao grupo não infectado (p> 0,05). Houve associação entre o óbito e a DRC apenas nos gatos infectados (p= 0,02). Concluiu-se que, apesar de a ocorrência de doença renal crônica e de proteinúria não ter sido estatisticamente maior diante da infecção pelo FIV, a associação entre o óbito e a DRC nos animais infectados sugere que o FIV pode contribuir para o agravamento da DRC, levando a rápida deterioração do organismo e considerável diminuição da sobrevida. / Cats naturally infected with the feline immunodeficiency virus (FIV) develop a syndrome that share common characteristics with the human immunodeficiency virus (HIV) infection. For this reason, felines are considered a promising model for the study of HIV infection. HIV associated nephropathy is a common and concerning complication in human beings, resulting in progressive renal insufficiency. Likewise clinico-pathological findings in naturally infected cats suggest a renal involvement. To evaluate the occurrence of chronic kidney disease (CKD) in cats infected with FIV and to verify a possible association between both diseases, a population of 44 cats submitted to the same sanitary handling, diet and exposure to infectious agents was studied. Of these cats, 20 were naturally infected with FIV and 24 were free of FIV infection. Animals were periodically accompanied for a 18-month period through serum creatinine and urinary protein:creatinine ratio measures. The occurrence of CKD in cats infected with FIV was 45%, a value higher than the observed in non-infected cats (25%), but no statistical difference was found. Proteinuria in at least one moment of evaluation was observed in 60% of infected cats and in 26,1% of non-infected cats (p=0,037). Considering the criterion of persistent proteinuria as the observation of urinary protein excretion in at least 3 consecutive moments, infected cats exhibited occurrence of 30,8% compared with 6,7% in the non-infected group (p>0,05). It was observed an association between death and CKD only in the cats infected with FIV (p=0,02). In conclusion, despite occurrence of CKD and proteinuria have not been statistically higher in infected cats than in non-infected one, the association between death and CKD in FIV-infected cats suggests FIV may contribute for the worsening of CKD, resulting in a quicker organic dysfunction and marked reduction of survival.

O Sarcoma de Aplicação Felino (SAF) possui características específicas pouco estudadas. A agressividade, com invasão profusa de tecidos adjacentes, bem como a presença de células anaplásicas em sua composição fazem do SAF um obstáculo a ser transposto, para obtenção do melhor tratamento. Sua etiologia e etiopatogenia ainda permanecem obscuras. O objetivo deste estudo consistiu em determinar fatores prognósticos para o paciente portador de SAF, caracterizando-o quanto ao seu peso e escore de condição corporal (ECC), à origem e diferenciação da neoplasia por ele apresentada, bem como caracterizar o microambiente perineoplásico quanto à presença de células inflamatórias. Foram selecionados 46 casos de SAF, sendo 31 casos novos de pacientes e 22 casos reavaliados. Foi encontrada diferença significativa entre o ECC (p=0,001) e peso (p<0,001) de pacientes que apresentaram SAF e os do grupo controle. Não foram encontradas diferenças entre gênero e raça. A localização mais comumente acometida foi a tóraco-abdominal (78%). Quanto à origem, a maioria dos SAF apresentou-se como originada em células fibroblastos. Enquanto não houve marcação para componentes inflamatórios (CD3 e CD68), houve para receptor de quinase (c-kit), para Cox-2 e FelV. Não houve influencia dos parâmetros avaliados com as variáveis clínicas e com a sobrevida total. Houve influencia estatisticamente significante quando comparamos a invasão observada no exame de tomografia computadorizada e a escolha do tratamento instituído (p=0,019). / The feline injection-site sarcoma (FISS) has specific characteristics which are little studied. FISS treatment is a hurdle to getting because of their aggressiveness, with profuse invasion of adjacent tissue, as well as the presence of anaplastic cells in its composition. Its etiology and pathogenesis remain obscure. This research aims to determine prognostic factors for patients with FISS, characterizing it as their weight and body condition score (BCS) and by the origin and differentiation of the tumor presented, along with characterizing the microenvironment peri-neoplastic for the presence of inflammatory cells. 46 cases of cats that presented FISS were assisted, with 31 new cases and 22 cases of patients reassessed. Statistical difference was found between the BCS (p=0,001) and weight (p<0,001) of FISS group and control group. No differences were found between gender and race. The region most commonly affected was the toraco-abdominal (78%). The FISS majority presented as fibroblasts origin, while no marking for inflammatory components (CD3 and CD68). There was marking for kinases cascade (c-KIT), for COX-2, and for FelV. There was no influence of the parameters evaluated with clinical variables and overall survival. There was a statistically significant influence when comparing the invasion observed in computerized tomographic examination and choice of the treatment (p = 0.019).

O sarcoma de aplicação em felinos (SAF) é uma neoplasia rara de origem mesenquimal e com prognóstico desfavorável que se desenvolve em local previamente utilizado para aplicações de medicamentos injetáveis ou submetido a traumas. Poucos estudos foram encontrados na literatura descrevendo os aspectos imaginológicos do SAF. O objetivo dessa pesquisa foi descrever os aspectos das imagens de tomografia computadorizada e ultrassonografia do SAF (modo B e Doppler colorido e amplitude), verificando características comuns, particularidades da formação recidivante e correlações com variáveis clínicas. A pesquisa contemplou uma fase prospectiva e outra retrospectiva, totalizando 32 felinos. Ao exame tomográfico, observou-se com maior frequência formas neoplásicas irregulares (62,5%), com prolongamentos digitiformes (100%), realce periférico e heterogêneo (67,7%), borramento dos planos adiposos (68,8%) e áreas sugerindo necrose intratumoral (68,8%). Ao exame ultrassonográfico observou-se contornos irregulares, presença de halo hiperecogênico, ecotextura heterogênea, tecido hiperecogênico contíguo à formação e espessamento hipoecogênico do subcutâneo adjacente, além de ecogenicidade mista, devido à presença de áreas sugerindo necrose intratumoral (83,3%). Ao estudo Doppler, observou-se distribuição vascular mais evidente na região periférica (83,3%), com calibre homogêneo (83,3%), fluxo regular (50%) e misto (50%). A quantidade de vasos neoplásicos detectados pela TC foi maior do que por US Doppler (p=0,024). O volume e o tempo de evolução da formação apresentaram alta correlação nos casos não recidivantes (p<0,001). A presença de metástase salteada foi mais comum em formações recidivantes (p=0,001). O uso de meio de contraste intravenoso e do recurso MPR permitiu melhor delimitação das margens da formação pela TC e uma mensuração neoplásica mais criteriosa. Os histogramas revelaram uma quantidade representativa de gordura na composição do SAF, e foi observada quantidades superiores de músculos acometidos na presença de um espessamento da gordura adjacente à formação (p=0,003). Os exames de diagnóstico por imagem foram importantes para caracterização do SAF, especialmente no que se refere a delimitação de suas margens e na avaliação dos tecidos adjacentes, além de fornecerem informações relevantes para o estadiamento neoplásico e para terapêutica. / The feline injection-site sarcoma (FIIS) is a rare mesenchymal neoplasm and has poor prognosis. It develops in a site previously used for intravenous applications or undergone trauma. Few studies were found in the literature describing the imaging features of FIIS. The aim of this research was to describe computed tomographic (CT) and ultrasonographic (B mode, color and power Doppler) images of FIIS to find common characteristics, particularities of disease recurrence and correlations with clinical variables. The study had a prospective and a retrospective phases, totaling 32 cats. At the CT scan it was observed more frequently an irregular neoplastic forms (62,5%) with fingerlike projections (100%), peripheral and heterogeneous enhancements (67,7%), blurring of the adjacent fat (68,8%) and areas suggesting intratumoral necrosis (68,8%). At the ultrasound it was observed irregular outlines, with hyperechoic halo, heterogeneous echotexture, hyperechogenic tissue adjacent at the tumor and thickening of the adjacent hypoechogenic subcutaneous tissue. Mixed echogenicity with areas suggesting intratumoral necrosis was generally observed (83,3%). Doppler study showed more evident vascular distribution in the peripheral region (83,3%) with homogeneous diameter (83,3%), smooth (50%) and mixed (50%) flow. The quantity of tumor vessels was higher at CT than Doppler ultrasound (p=0,024). The presence of a vessel tumor coming from vessels of the abdominal cavity on CT may be an important finding for surgical planning. Tumor volume and time of presentation were correlated with non-recurrent cases (p<0,001). Skip metastasis showed high correlation with recurrent cases (p=0,001). The use of postcontrast phase at CT scans and MPR allowed better delineation of tumor margins and a more carreful measurement. Histograms revealed a representative amount of fat in tumor composition. A tendency of higher amounts of muscles being involved was observed with fat thickening near the tumor (p=0,003). Diagnostic imaging was important to characterization of FIIS, especially to delimitate tumor extension, evaluate compromised adjacent tissues providing relevant information for tumor staging and therapeutic planning.