The purpose of this study was to report the scintigraphic and sonographic appearance of the thyroid gland in clinically normal horses so these modalities could be used to assess the thyroid gland in this species. Horses were divided into two age groups. Group A consisted of 8 horses between 3 and 10 years of age and Group B of 7 horses between 11 and 20 years of age. Total T4 concentrations were within the laboratory reference interval. Thyroid to salivary (T/S) ratio, percent dose uptake of pertechnetate and thyroid lobe volume were calculated. Echogenicity of thyroid lobes and presence of nodules were documented. The two groups were compared using appropriate parametric and nonparametic tests. Total T4 concentrations were significantly lower in the older group. Sixty minute mean ± standard deviation (SD) T/S ratios for older versus younger horses were 5.8 ± 3.0 and 5.3 ± 2.2, respectively. Sixty minute median and interquartile ranges for percent dose uptake of pertechnetate for older versus younger horses were 3.64% (1.5 to 3.98%) and 2.55% (2.33 to 2.90%), respectively. Mean ± SD thyroid lobe volumes for older versus younger horses were 18.93 ± 5.16 cm3 and 13.55 ± 3.56 cm3, respectively. Most thyroid lobes were hyper or isoechoic to the sternocephalicus muscle. Prevalence of thyroid nodules did not differ between groups. Older horses had trends for greater T/S ratios, percent dose uptakes and thyroid lobe volumes but had lower total T4 concentrations. Further studies using scintigraphy and ultrasound in horses with thyroid disease are planned. / 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

No description available.

No description available.

This thesis deals with the diffusion of ions in compactedbentonite clay. Laboratory experiments were performed toexamine in detail different processes that affect thediffusion. To demonstrate that the results obtained from thelaboratory investigations are valid under in situ conditions,two different kinds of in situ experiments were performed. Laboratory experiments were performed to better understandthe impact of ionic strength on the diffusion of Sr2+ and Cs+ions, which sorb to mineral surfaces primarily by ion exchange.Furthermore, surface related diffusion was examined anddemonstrated to take place for Sr2+ and Cs+ but not for Co2+,which sorbs on mineral surfaces by complexation. The diffusion of anions in bentonite clay compacted todifferent dry densities was also investigated. The resultsindicate that anion diffusion in bentonite clay consists of twoprocesses, one fast and another slower. We ascribe the fastdiffusive process to intralayer diffusion and the slow processto diffusion in interparticle water, where anions are to someextent sorbed to edge sites of the montmorillonite. Two different types of in situ experiments were performed,CHEMLAB and LOT. CHEMLAB is a borehole laboratory, where cation(Cs+, Sr2+ and Co2+) and anion (I- and TcO4-) diffusionexperiments were performed using groundwater from a fracture inthe borehole. In the LOT experiments cylindrical bentoniteblocks surrounding a central copper rod were placed in a 4 mdeep vertical borehole. The borehole was then sealed and theblocks are left for 1, 5 or>>5 years. When the bentonitewas water saturated the central copper rod is heated tosimulate the temperature increase due to radioactive decay ofthe spent fuel. Bentonite doped with radioactive Cs and Co wasplaced in one of the lower blocks. Interestingly, the redox-sensitive pertechnetate ion (TcO4-)which thermodynamically should be reduced and precipitate asTcO2·nH2O, travelled unreduced through the bentonite.However, at some spots in the clay, the Tc activity wasconsiderably higher. We ascribe these activity peaks toiron-containing minerals in the bentonite, by which Tc(VII) hasbeen reduced to Tc(IV) and precipitated. The cations Sr2+, Cs+and Co2+, as well as the anion I-, behaved in the CHEMLABexperiments as expected from laboratory studies. Three experiments in the LOT series are completed. The firsttwo diffusion experiments in LOT were less successful, thefirst due to the fact that saturation of the bentonite was notobtained during the experimental period and the radionuclidesdid not move at all. In the second, the uptake of the bentoniteparcel was less successful. Water from the drilling flushedaway large pieces of the top part of the bentonite and thelower part of the test parcel was super-saturated with waterand expanded when released from the rock. The activity distribution in the second experiment wasanalysed. The Co2+ profile looked as we had expected, while Cs+had spread more than our calculations indicated. However, thethird experiment was successful from emplacement, watersaturation and heating to uptake. The activity distribution forboth cations was as expected from laboratory studies. Altogether the three different types of experiments give auniform picture of radionuclide diffusion in bentonite clay forthe ions investigated. / QC 20100621

No description available.

L'objectif de cette thèse est d’étudier temporellement des phénomènes évolutifs à l'aide de la tomographie d'émission monophotonique (TEMP). La première partie de cette thèse traite le problème du mouvement respiratoire dans les images TEMP de souris. Nous présentons ici une méthode permettant de détecter ce mouvement respiratoire dans les images TEMP 4D, d'extraire un signal respiratoire intrinsèque, et de déterminer la phase du cycle respiratoire sans mouvement la plus large possible. Les données enregistrées durant ces phases sans mouvement sont alors utilisées pour reconstruire une seule image TEMP 3D sans artefact de mouvement par acquisition. Les images ainsi reconstruites présentent un bon compromis en terme de statistiques et de précision des mesures par rapport aux images TEMP 3D de base et TEMP 4D. Dans la deuxième partie, nous étudions la cinétique d'incorporation de l'iode dans l'estomac de souris à partir d'images TEMP 4D. Afin de comprendre le rôle biologique de cette accumulation dans l'estomac, nous avons modélisé le phénomène par une approche d'analyse compartimentale avec un modèle simplifiée à deux compartiments (paroi et cavité stomacale) et une entrée (sang). Les courbes temps-activité (TAC) de chaque compartiment sont déduites des observations et une première estimation des paramètres a été obtenue. / The aim of this thesis is to investigate temporally evolving phenomena with the use of single photon emission computed tomography (SPECT).The first part of this thesis addresses the problem of respiratory motion in SPECT images of mice. The presented method permits us to detect the respiratory motion in 4D SPECT images, to extract an intrinsic respiratory signal and to determine the widest possible phase of the respiratory cycle without movement. The data recorded during these motionless phases are then used to reconstruct a single 3D SPECT image without motion artefacts per acquisition. Reconstructed motionless SPECT images present a good compromise in terms of statistics and accuracy of the measurements with respect to basic 3D SPECT and 4D SPECT images. In the second part, we study the iodide uptake kinetics in the stomach 99mTc-pertechnetate biodistribution with the of mice through the study of use of 4D SPECT images. To understand the biological role of the iodide accumulation in the stomach, we modelled the phenomenon with a compartmental analysis approach using a simplified two-compartment (stomach wall and cavity) model with one input (blood). Time activity curves (TAC) of each compartment are deduced from observations and a first estimation of the parameters was obtained.

Made available in DSpace on 2014-12-17T14:13:33Z (GMT). No. of bitstreams: 1 MonicaOB.pdf: 219560 bytes, checksum: 3e717232b47facd68d9fede60401e898 (MD5) Previous issue date: 2007-12-05 / Radiobiocomplexes are used to obtain images in nuclear medicine and employed in basic research. Blood constituents labeled with technetium-99m (99mTc) have also been employed as radiobiocomplexes and used also experimental model for evaluation of the biological effects of natural or synthetic drugs. The analysis of the morphology and the morphometrics parameters (perimeter/?rea ratio) can be used to evaluate the effects of drugs upon the structure of the membrane of red blood cells. Cinnamomum zeylanicum (cinnamon) is a spice used as herbal medicine to treat diseases. The aim of this study was to evaluate the effect of in vitro and in vivo treatment with an aqueous cinnamon extract on the labeling of blood constituents with 99mTc and on the morphology of red blood cells from Wistar rats. In the in vitro treatment, isolated blood sample from animals were incubated with cinnamon extract. In the in vivo treatment, blood samples were also withdrawn from animals treated with cinnamon extract. In both cases, the radiolabeling of blood constituents was done. The morphological analysis of red blood cells was also done. As control, blood or animals treated with NaCl 0.9%. The data obtained on the labeling of blood constituents with 99mTc experiments indicated that the in vitro treatment with cinnamon extract was capable to decrease signiicantly (p<0.05) the percentage of radioactivity in cellular compartments and on the fixation of cellular and plasma proteins. These effects were not observed on the in vivo treatment. The results obtained for the morphology of red blood cells suggest that the in vitro and in vivo treatments did not alter the morphology and the perimeter/area ratio. The in vitro treatment with aqueous cinnamon extract could affect the membrane structures related with the oxidation status of the stannous ion pertechnetate ion, altering the labeling of blood constituentes with 99mTc. This study was a multidisciplinary experimental research. It was developed with the contribution of the different Departments and Services of the Hospital Universit?rio Pedro Ernesto of the Universidade do Estado do Rio de Janeiro / Radiobiocomplexos s?o utilizados para obten??o de imagens em medicina nuclear e empregados na pesquisa b?sica. Constituintes sang??neos marcados com tecn?cio-99m t?m sido empregados como radiobiocomplexos e utilizados como modelo experimental para avalia??o de efeitos biol?gicos de drogas naturais ou sint?ticas. A an?lise da forma e de par?metros morfom?tricos (rela??o per?metro/?rea) pode ser usada para avaliar os efeitos de drogas sobre a estrutura da membrana de hem?cias. Cinnamomum zeylanicum (canela) ? uma especiaria usada como planta medicinal para tratar doen?as. O objetivo desse estudo foi avaliar efeitos de um extrato aquoso de Cinnamomum zeylanicum na marca??o de constituintes sangu?neos com tecn?cio-99m e na morfologia de hem?cias de ratos Wistar. No tratamento in vitro, amostras de sangue de animais foram isoladas e incubadas com um extrato de canela. No tratamento in vivo, animais foram tratados com um extrato de canela e amostras de sangue foram isoladas. Em ambas as situa??es foram realizadas a radiomarca??o de constituintes sangu?neos e a an?lise morfol?gica. Como controle, o sangue ou os animais foram tratados com cloreto de s?dio 0,9%. Os dados obtidos nos experimentos de marca??o de constituintes sang??neos com tecn?cio-99m indicaram que o tratamento in vitro com extrato de canela foi capaz de diminuir significativamente (p<0,05) a porcentagem de radioatividade nos compartimentos celulares e na fixa??o das prote?nas celulares e plasm?ticas. Esses efeitos n?o foram observados no tratamento in vivo. Os resultados obtidos na morfologia de hem?cias sugerem que os tratamentos in vitro e in vivo n?o alteram a forma nem a raz?o per?metro/?rea. O tratamento in vitro com o extrato aquoso de canela poderia afetar estruturas da membrana celular relacionadas ao transporte de ?ons ou ao estado de oxida??o do ?on estanoso ou do ?on pertecnetato, alterando a marca??o de constituintes sang??neos com tecn?cio-99m. Esse estudo ? uma pesquisa experimental com car?ter multidisciplinar. Foi desenvolvido em colabora??o com diferentes Departamentos e Servi?os da ?rea biom?dica do Hospital Universit?rio Pedro Ernesto, UERJ, atestando o car?ter multidisciplinar da pesquisa

Made available in DSpace on 2014-12-17T14:13:35Z (GMT). No. of bitstreams: 1 RosaneFN.pdf: 281954 bytes, checksum: efc3b9461d551e53306fba9f9fa21a9d (MD5) Previous issue date: 2008-03-25 / Radionuclides have been used in Nuclear Medicine for diagnostic and treatment. In basic research, cellular and molecular structures are labeled with technetium-99m (99mTc) and used as radiobiocomplexes. Some natural or synthetic drugs are capable to alter the labeling of blood constituents with 99mTc, as well as in the biodistribution of radiobiocomplexes. Arctium lappa (Bardana) has been used to treat inflammatory processes. The aim of this work was to evaluate the effects of an extract of Bardana on the labeling of blood constituents with 99mTc, on the morphology of red blood cells, on the perimeter/area ratio of red blood cells and on the biodistribution of radiophamaceutical sodium pertechnetate in Wistar rats. Extract of Bardana was capable to alter the labeling of cellular compartment with 99mTc. Plasma and cellular proteins did not present alteration on the percentage of radioactivity (%ATI). Extract of Bardana was also capable to alter the morphology and the perimeter/area ratio of red blood cells. On the biodistribution of sodium pertechnetate in animals treated with the extract of Bardana, it was observed a small and significant uptake in liver, tooth and tongue, and a high and a significant uptake in stomach, lung and testis (p<0.05). In conclusion, these findings could be justified due to the effects of some chemical compounds in the Bardana extract. This study was a multidisciplinary experimental research. It was developed with the contribution of the different Departments and Services of the Hospital Universit?rio Pedro Ernesto of the Universidade Estadual do Rio de Janeiro / Radionucl?deos t?m sido utilizados em Medicina Nuclear para diagn?stico e tratamento de doen?as. Estruturas moleculares e celulares marcadas com tecn?cio-99m (99mTc) s?o utilizados como radiobiocomplexos, como acontece com alguns constituintes sang??neos. Algumas drogas naturais ou sint?ticas s?o capazes de alterar a marca??o de constituintes sang??neos com 99mTc, bem como a disponibilidade de radiobiocomplexos. Arctium lappa (Bardana) tem sido empregada para tratar processos inflamat?rios. O objetivo deste estudo foi avaliar efeitos de um extrato de Bardana na marca??o dos constituintes sang??neos marcados com 99mTc, na morfologia e na rela??o per?metro/?rea das hem?cias e na biodistribui??o do radiof?rmaco pertecnetato de s?dio (Na99mTcO4). O extrato de Bardana foi capaz de alterar a distribui??o 99mTc no compartimento celular. As prote?nas plasm?ticas e celulares n?o apresentaram nenhuma altera??o na fixa??o de radioatividade (%ATI). O extrato de Bardana tamb?m foi capaz de alterar a morfologia e a rela??o per?metro/?rea das hem?cias. Na biodistribui??o do pertecnetato de s?dio em animais tratados com o extrato de Bardana, foi observada uma redu??o significante na capta??o do f?gado, dente e l?ngua, e uma alta capta??o no est?mago, pulm?o e test?culo (p<0,05). Em conclus?o, o extrato de Bardana parece possuir subst?ncias em sua composi??o que podem ser respons?veis pelos achados experimentais. Desenvolvido em diferentes Departamentos e Servi?os da ?rea biom?dica do Hospital Universit?rio Pedro Ernesto, UERJ, atestando o car?ter multidisciplinar da pesquisa

Made available in DSpace on 2014-12-17T14:13:59Z (GMT). No. of bitstreams: 1 DamasoAC.pdf: 717706 bytes, checksum: 9c84ebd8275bbc840147cc908c45f621 (MD5) Previous issue date: 2007-08-15 / Massive resection of the small intestine results in short bowel syndrome with anti-absorptive effect and repercussions on the metabolism. Morphologic and functional evaluation may be necessary in order to control wrapped organs. Scintigraphy an examination with little invading and no biologic damage can be used. The purpose were to assess the biodistribution of sodium pertecnetate in organs of rats subjected to massive resection of the small intestine, the intestinal adaptation of the remnant intestinal mucosa and weight curve evaluation in the postoperative period. Twenty-one Wistar rats were randomly allocated into three groups (n = 7). The operated group named short bowel (SB) after anesthetized was subjected to massive resection of the small intestine; the control group (C), and sham group (SHAM). On the 30th postoperative day, 0.l mL of sodium pertechnetate was injected into the venous orbital plexus. After 30 minutes, the rats were killed with an overdose of anesthetic, and fragments of the liver, spleen, pancreas, stomach, duodenum, small intestine, thyroid, lung, heart, kidney, bladder, muscle, femur and brain were harvested. The percentage of radioactivity per gram of tissue (%ATI/g) was determined using Gama Counter WizardTM 1470, PerkinElmer to all samples. Biopsies of 3 cm remaining jejunum were removed to histological analyses. Analysis of variance (ANOVA) and the Tukey test for multiple comparisons were used, considering p<0.05 as significant. The study had the participation of some departments and laboratories, as Nucleus of Experimental Surgery, Department of Surgery, Laboratory of Radiobiology, Department of Pathology and Service of Nuclear Medicine, certifying the character of a multidisciplinary research. The results were no significant differences in %ATI/g of the sodium pertechnetate in the organs of the groups studied (p>0.05). An increase in the weight of the SB rats was observed after the second postoperative week. The jejunal mucosal thickness of the SB rats was significantly greater than that of C and sham rats (p<0.05. The biodistribution of sodium pertechnetate was not affected by massive intestinal resection in rats. An adaptive response by the intestinal mucosa probably contributed to the reversion of weight loss and the biodistribution of sodium pertechnetate was not affected by the surgery / A ressec??o extensa do intestino delgado resulta na s?ndrome do intestino curto com repercuss?o desabsortiva importante. Uma avalia??o morfofuncional poder? ser necess?ria aos ?rg?os envolvidos no processo. O objetivo desse estudo foi avaliar a biodistribui??o do pertecnetato de s?dio em ?rg?os de ratos submetidos a ressec??o extensa do intestino delgado, a capacidade adaptativa da mucosa intestinal remanescente e o comportamento da curva ponderal p?s-operat?ria. Foram utilizados 21 ratos Wistar alocados aleatoriamente em tr?s grupos (n=7). O grupo tratado, denominado intestino curto (IC), foi submetido a anestesia e ressec??o ampla do intestino delgado, o grupo controle (C) e o grupo sham que submeteu-se ? leve manipula??o cir?rgica das al?as intestinais. Ap?s observa??o por trinta dias administrou-se, em todos os grupos, 0,l mL de pertecnetato de s?dio via plexo venoso orbital. Decorridos trinta minutos os animais foram sacrificados com superdose de anest?sico para retirada de fragmentos do f?gado, ba?o, p?ncreas, est?mago, duodeno, intestino delgado, tire?ide, pulm?o, cora??o, rim, bexiga, m?sculo, f?mur, e c?rebro. As amostras foram levadas ao Contador Gama Autom?tico 1470, WizardTM, Perkin-Elmer para contagem da radioatividade e posterior c?lculo do percentual de atividade radioativa por grama (%ATI/g) em cada ?rg?o. Segmentos de 3cm do jejuno foram retirados para an?lise histol?gica da mucosa. Utilizou-se avalia??o estat?stica param?trica (ANOVA) e teste de Tukey, considerando p<0,05 como significante. N?o houve diferen?as significantes da %ATI/g nos ?rg?os dos grupos estudados. Verificou-se acentuada redu??o inicial de peso, em seguida um aumento do peso dos animais tratados a partir da segunda semana de observa??o e aumento da espessura da mucosa jejunal do grupo IC, comparado com os demais. Em conclus?o, a ressec??o ampla do intestino delgado n?o alterou a biodistribui??o do radiof?rmaco nos ?rg?os avaliados entre os animais estudados. A adapta??o da espessura da mucosa pode ter contribuido para revers?o na perda de peso p?s-operat?ria e para que a biodistribui??o do pertecnetato de s?dio n?o fosse afetada pela interven??o cir?rgica. O trabalho teve um car?ter multidisciplinar com a participa??o de v?rios departamentos e laborat?rios, como N?cleo de Cirurgia, Departamento de Cirurgia, Laborat?rio de Radiobiologia, Departamento de Patologia e Servi?o de Medicina Nuclear, atestando o car?ter multidisciplinar da pesquisa