Digitalis in one of the most frequently prescribed drugs, especially to elderly people. The prescription of cardiac glucosides (1978) was studied by using statistics from Apoteksbolaget (the National Corpora­tion of Swedish Pharmacies). There was a threefold difference in the sales of cardiac glucosides per 1000 inhabitants in the different primary care areas. Digoxin was prescribed to 90-98 per cent of the patients, with considerable variations in the dosages. Many other factors besides the cardio-vascular morbidity were likely to cause these differences. Maintenance digitalis therapy has lately been questioned. In a retro­spective study, digitalis was discontinued in 141 geriatric patients without contraindications to digitalis withdrawal. Digoxin treatment seemed to be unnecessary in 108 patients (81 per cent), followed up two months after digoxin withdrawal. A long-term study (mean: 20,5 months) was carried out in these 108 patients. Digitalis therapy was reinstituted in 30 of 99 patients, equally distributed on the basis of clear, possible or uncertain indications. Significantly more patients (p&lt; 0,001) with atrial fibrillation compared with sinus rhythm were restarted. A prospective, randomized, double-blind placebo- controlled study in 39 out of 66 geriatric patients confirmed the results of the retrospective study. During a two-month period 32 of 37 patients (86 per cent) managed without digitalis. Eighteen out of 66 patients (27 per cent) presented contraindications to digoxin with­drawal. Those who needed digitalis were restarted mainly during the first nonth (mean: 18 days) following digoxin withdrawal. Digitalis intoxication has been studied earlier, mainly in hospitalized patients. A clinical examination and ECG of a random sample of out­patients treated with digoxin shewed that about 5 per cent were certainly intoxicated and about 2 per cent suspected of being intoxi­cated. Elderly patients are said to be more sensitive to digitalis. Eleven per cent of 66 geriatric patients were found, without doubt, to be digitalis intoxicated. The mean serum digoxin concentration was significantly higher in eight toxic patients compared with non-toxic patients, but 75 per cent of the toxic patients had serum digoxin con­centrations within or below therapeutic range. Five of these intoxi­cated patients did not need maintenance digitalis therapy. A questionnaire of 361 patients in Skellefteå and Uppsala revealed that about 45 per cent had taken digitalis for more than five years. Approximately 85 per cent took one tablet daily and stated compliance. About one fifth did not know why they were taking digoxin and about half of the patients were uncertain if they were improved, by digitalis therapy. Although digitalis intoxication is such an important clinical problem, some 55 per cent did not know about digitalis's side-effects and some 50 per cent stated that no or insufficient information had been given. Only 15 per cent were satisfied with the information they had received. A significant negative correlation between digoxin dosages and the age of the patients was found. / <p>Diss. Umeå : Umeå universitet, 1983, härtill 7 uppsatser</p> / digitalisering@umu

Background The potential dire consequences of iron deficiency (ID) and iron deficiency anaemia (IDA) on childhood development are of major public health concern. Many factors contribute to anaemia, ID being only one progressive factor. The prevalence of ID and IDA must be accurately determined before iron intervention strategies can be safely prescribed. There is continued uncertainty regarding the optimal approach to identifying and measuring ID, as indicators have different roles, explore different aspects of iron metabolism and cannot be directly compared. Furthermore, inflammation and infection have a confounding effect on the commonly applied indicator and acute phase reactant, serum ferritin (SF). In the public health setting, a suitable method to assess iron status in developing countries has to be inexpensive, standardised, established, easy to measure and its applications specific to identifying ID. Aim We conducted secondary analysis of screening data from three independent iron intervention studies to critically evaluate the indicators used to determine iron status in 6-11-year-old primary school children from three South African provinces. Study design and methods A cross-sectional descriptive analysis was performed on the screening data collected in 2009 and 2010 during iron intervention studies in KwaZulu-Natal (n=736), Northern Cape (n= 1045), and North West (n=546). The three distinct study sites were analysed independently and collectively. Children’s haemoglobin (Hb), SF, transferrin receptor (TfR), zinc protoporphyrin (ZPP), and C-reactive protein (CRP) concentrations were measured and body iron calculated. ID prevalence was compared using different methods (namely the single indicators SF, TfR and ZPP, body iron and the multiple criteria model), and the influence of inflammation on SF was considered. Literature suggests that the multiple criteria model provides a more complete assessment of iron status. The performance of single and body iron indicators were compared to the multiple criteria model (by assessing sensitivity, specificity and predictive values). Results Significant positive correlations between CRP (indicator of inflammation) and SF existed in all study sites and the combined sample (p < 0.01). The mean SF concentration was substantially higher in subjects with inflammation than those without. A different SF cut-off to identify ID was applied to subjects with inflammation. The percentage of ID subjects varied using different indicators (4.2 – 26.5% in KwaZulu-Natal; 4.1 – 13.4% in Northern Cape; 7.0 – 24.4% in North West; and 5.4 – 15.2% in the combined sample). The sensitivity, specificity and predictive values of alternate ID indicators varied within and between study sites, compared to the multiple criteria model. Conclusion Simply using Hb as an ID indicator is inaccurate. The vast differences between percentages identified as ID by different indicators is reason for concern. No consistent agreement appeared between single ID indicators, body iron and the multiple criteria model for ID identification after correcting for inflammation in primary school children. The global view of the multiple criteria model as the gold standard for estimating ID is debatable and potentially impractical at a public health level. Current evidence cautions against overestimating the prevalence of ID, as there is more associated harm than deficiency underestimation. This critical analysis has confirmed a need for research to identify a suitable, accurate and precise alternative to Hb as a tool in the South African public health setting. Furthermore, the impact of inflammation on iron status indicators, in particular SF, should be assessed in context to clearly set parameters for its use in nationally-representative nutrition surveys, the cornerstone of iron intervention strategies. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2015

Background The potential dire consequences of iron deficiency (ID) and iron deficiency anaemia (IDA) on childhood development are of major public health concern. Many factors contribute to anaemia, ID being only one progressive factor. The prevalence of ID and IDA must be accurately determined before iron intervention strategies can be safely prescribed. There is continued uncertainty regarding the optimal approach to identifying and measuring ID, as indicators have different roles, explore different aspects of iron metabolism and cannot be directly compared. Furthermore, inflammation and infection have a confounding effect on the commonly applied indicator and acute phase reactant, serum ferritin (SF). In the public health setting, a suitable method to assess iron status in developing countries has to be inexpensive, standardised, established, easy to measure and its applications specific to identifying ID. Aim We conducted secondary analysis of screening data from three independent iron intervention studies to critically evaluate the indicators used to determine iron status in 6-11-year-old primary school children from three South African provinces. Study design and methods A cross-sectional descriptive analysis was performed on the screening data collected in 2009 and 2010 during iron intervention studies in KwaZulu-Natal (n=736), Northern Cape (n= 1045), and North West (n=546). The three distinct study sites were analysed independently and collectively. Children’s haemoglobin (Hb), SF, transferrin receptor (TfR), zinc protoporphyrin (ZPP), and C-reactive protein (CRP) concentrations were measured and body iron calculated. ID prevalence was compared using different methods (namely the single indicators SF, TfR and ZPP, body iron and the multiple criteria model), and the influence of inflammation on SF was considered. Literature suggests that the multiple criteria model provides a more complete assessment of iron status. The performance of single and body iron indicators were compared to the multiple criteria model (by assessing sensitivity, specificity and predictive values). Results Significant positive correlations between CRP (indicator of inflammation) and SF existed in all study sites and the combined sample (p < 0.01). The mean SF concentration was substantially higher in subjects with inflammation than those without. A different SF cut-off to identify ID was applied to subjects with inflammation. The percentage of ID subjects varied using different indicators (4.2 – 26.5% in KwaZulu-Natal; 4.1 – 13.4% in Northern Cape; 7.0 – 24.4% in North West; and 5.4 – 15.2% in the combined sample). The sensitivity, specificity and predictive values of alternate ID indicators varied within and between study sites, compared to the multiple criteria model. Conclusion Simply using Hb as an ID indicator is inaccurate. The vast differences between percentages identified as ID by different indicators is reason for concern. No consistent agreement appeared between single ID indicators, body iron and the multiple criteria model for ID identification after correcting for inflammation in primary school children. The global view of the multiple criteria model as the gold standard for estimating ID is debatable and potentially impractical at a public health level. Current evidence cautions against overestimating the prevalence of ID, as there is more associated harm than deficiency underestimation. This critical analysis has confirmed a need for research to identify a suitable, accurate and precise alternative to Hb as a tool in the South African public health setting. Furthermore, the impact of inflammation on iron status indicators, in particular SF, should be assessed in context to clearly set parameters for its use in nationally-representative nutrition surveys, the cornerstone of iron intervention strategies. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2015

The gonococcal transferrin binding proteins (Tbps) are two surface-exposed outer membrane proteins, TbpA and TbpB, which together function to remove and internalized iron from human transferrin. Iron is an essential nutrient to the gonococcus, without which it cannot survive. The Tbps have been established as virulence factors, demonstrating their importance in establishing infection. Both TbpA and TbpB are well conserved among gonococcal isolates, and have been considered potential vaccine targets. Vaccine studies with the closely related species Neisseria meningitidis, have demonstrated these proteins to be protective in murine challenge studies. Though the meningococcal Tbps have demonstrated promise, no similar gonococcal vaccine experiments have been conducted prior to the current studies. Here we demonstrate purification of recombinant TbpA and TbpB. These recombinant proteins were utilized to evaluate the human immune response to these proteins during natural infections, and their immunogenicity in murine vaccine studies. Our results demonstrate a paucity of antibodies elicited to these proteins during natural infections in serum and mucosal secretions from infected individuals. From this study we hypothesized the induction of both serum and genital antibodies to these proteins could serve to protect an individual from infection. To begin testing this hypothesis, we immunized mice both intranasally (IN) and subcutaneously (s.c.) with full-length Tbps in conjunction with the B subunit of cholera toxin (Ctb) as an adjuvant. We also performed another vaccine study using domains from both proteins in genetic fusions with Ctb and E. coli heat labile toxin IIb (LtbIIb). Both studies demonstrated that these antigens were immunogenic, as Tbp-specific antibodies were elicited in the serum and vaginal washes of female Balb/C mice. Intranasal immunization however was the only route with which we were able to elicit vaginal Tbp-specific IgA, and IgG, whereas subcutaneous immunization only elicited vaginal IgG. Furthermore, we found the full-length Tbps and the Ctb/LtbIIb chimeras were able to elicit bactericidal antibodies, which were also effective in killing heterologous gonococcal strains. This body of work comprises the first published study using the gonococcal transferrin binding proteins as vaccine antigens, and highlights their potential as vaccine antigens in the development of an efficacious gonococcal vaccine.

Neuronal plasticity deficits underlie many of the neurobehavioral problems seen in Fetal Alcohol Spectrum Disorders (FASD). Recently, we showed that third trimester alcohol exposure lead to a persistent disruption in ocular dominance (OD) plasticity. For instance, few days of monocular deprivation results in a robust reduction of cortical regions responsive to the deprived eye in normal animals, but not in ferrets exposed early to alcohol. This plasticity deficit can be reversed if alcohol-exposed animals are treated with a phosphodiesterase type 1 (PDE1) inhibitor during the period of monocular deprivation. PDE1 inhibition can increase cAMP and cGMP levels, activating transcription factors such as the cAMP response element binding protein (CREB) and the Serum response factor (SRF). SRF is important for many plasticity processes such as LTP, LTD, spine motility and axonal pathfinding. Here we attempt to rescue OD plasticity in alcohol-treated ferrets using a Sindbis viral vector to express a constitutively active form of SRF during the period of monocular deprivation. Using optical imaging of intrinsic signals and single unit recordings we observed that overexpression of a constitutively active form of SRF (Sindbis SRF+), but neither its dominant negative (SRF-) nor GFP, restored OD plasticity in alcohol-treated animals. Surprisingly, this restoration was observed throughout the extent of the primary visual cortex and most cells infected by the virus were positive for GFAP rather than NeuN. Hence, we further tested whether overexpression of SRF exclusively in astrocytes is sufficient to restore OD plasticity in alcohol-exposed ferrets. To accomplish that, first we exposed cultured astrocytes to the SRF+, SRF- or control GFP viruses. After 24h, these astrocytes were implanted in the visual cortex of alcohol-exposed animals or saline controls one day before MD. Optical imaging of intrinsic signals showed that alcohol-exposed animals that were implanted with astrocytes expressing SRF, but not SRF- or GFP, showed robust restoration of OD plasticity in all visual cortex. These findings suggest that overexpression of SRF exclusively in astrocytes can improve neuronal plasticity in FASD.

Le rôle de l'inflammation dans le développement et la progression des maladies rénales chroniques (MRC) chez le chat a été peu étudié. L'hepcidine est une protéine de la phase aigue (PPA) de l'inflammation qui contribue au développement des anémies lors de MRC chez l'homme. Les objectifs de cette étude sont de comparer les concentrations en PPAs, en erythropoietine (EPO) ainsi que le statut en fer entre un groupe de chats sains et en MRC. 18 chats sains et 38 chats en MRC ont été recrutés de façon prospective. Les examens réalisés incluaient hématologie, biochimie, analyse d'urine, Serum amyloid A (SAA), haptoglobine (HAP), EPO, hepcidine,fer, TIBC et ferritinne. Nous avons observé une augmentation significative des concentrations en SAA et en hepcidine ainsi qu'une diminution significative du fer et du TIBC dans le groupe MRC (P < .05). Une corrélation positive entre la créatinine et certaines PPAs (SAA and hepcidin; P < .05) était présente. L'augmentation de SAA et hepcidine était significativement associé avec une diminution du TIBC et de l'hématocrite dans le groupe MRC. Les 14 (37%) chats anémiques du groupe MRC avaient une concentration significativement plus basse en fer et en TIBC (P < .05), changements compatibles avec une déficience fonctionelle en fer. Aucun chat n'avait un panel de fer compatible avec une carence en fer absolue. En conclusion, les résultats de cette étude suggèrent que les MRC chez le chat sont des conditions pro-inflammatoires, ayant un impact sur le métabolisme du fer. / The role of inflammation in the development and progression of feline chronic kidney disease (CKD) is not well characterized. Hepcidin, a recently discovered acute phase protein (APP) contributes to the development of anemia in human patients with CKD. The objectives of our study was to compare plasma APP including hepcidin, iron status, and erythropoietin (EPO) concentrations between healthy and cats with naturally occurring CKD. Eighteen healthy control cats and 38 cats with CKD were prospectively recruited. Complete physical examination along with hematology, biochemistry, plasma amyloid A (SAA), haptoglobine (HAP), EPO, iron, TIBC and ferritin were performed using routine laboratory analyses and commercially available feline ELISA-assays. Hepcidin-25 concentration was assessed with a human ELISA kit (DRG® Diagnostics). We found that mean SAA and hepcidin concentration were significantly higher and mean total iron and TIBC were significantly lower in the CKD group (P < .05). There was a significant positive correlation between creatinine and APPs (SAA and hepcidin; P < .05). Increase in SAA and hepcidin was also significantly associated with decrease of TIBC and PCV in the CKD group. The 14 (37%) anaemic cats with CKD had significantly and lower iron, TIBC, consistent with functional iron deficiency (P < .05). There were no patients with an iron profile suggestive of a true iron deficiency. There was no association with survival. In conclusion, our data suggest that feline CKD is a pro-inflammatory state, having significant impact on iron metabolism. With further validation, hepcidin may help better characterize these interactions.

Le carcinome hépatocellulaire (CHC) est la 3ème cause de mortalité par cancer dans le monde. L'identification de nouveaux marqueurs sériques est cruciale pour améliorer le pronostic. Dans ce travail, nous avons évalué l'intérêt de la spectroscopie vibrationnelle, infrarouge et Raman, appliquée au sérum pour le diagnostic du CHC. Dans un premier temps, nous avons réalisé 2 études pilotes pour évaluer le potentiel de ces deux approches. L'intérêt de la spectroscopie Raman appliquée au sérum a été évalué chez 37 patients cirrhotiques avec CHC et 34 patients cirrhotiques sans CHC. L'analyse des données spectrales a permis de classer les patients avec un taux d'exactitude diagnostique de 85 à 91%. Nous avons également démontré l'intérêt diagnostique de la spectroscopie IRTF dans une population de 40 patients avec CHC et 39 patients sans CHC. Dans cette étude, le taux d'exactitude diagnostique était de 82 à 86%. Dans un deuxième temps, nous avons mené une étude sur un plus grand nombre de patients afin de valider les résultats obtenus dans l'étude pilote IRTF. Les caractéristiques spectrales IRTF du sérum de 308 patients cirrhotiques avec CHC ont été comparées à celles du serum de 509 patients cirrhotiques sans CHC. L'analyse des données spectrales par deux méthodes de classification supervisée, SVM et PLS-DA, n'a pas permis de confirmer les résultats obtenus dans cette étude pilote. Avec un taux d'exactitude diagnostique entre 50 et 60 %, l'analyse spectrale IRTF du sérum entier n'apparait pas discriminante pour distinguer les patients cirrhotiques avec et sans CHC. Ce résultat souligne la nécessité de confirmer sur un grand nombre de patients les résultats obtenus dans des études pilotes. L'analyse spectrale ciblée sur des fractions du sérum pourrait permettre d'identifier plus efficacement des marqueurs diagnostiques en évitant la superposition des informations spectrales liées aux multiples molécules présentes dans le sérum entier. / Hepatocellular carcinoma (HCC) is the third cause of cancer death in the world. The identification of novel serum markers is crucial to improve the prognosis. In this work, we evaluated the potentiels of vibrational spectroscopy, infrared and Raman spectroscopy, applied to serum to diagnose HCC. On a first step, two pilot studies were conducted to evaluate these two approaches. Raman spectroscopy applied to the serum was tested in 37 cirrhotic patients with HCC and 34 cirrhotic patients without HCC. Analysis of spectral data showed that it was possible to classify patients with a diagnostic accuracy rate of 85 to 91%. We also demonstrated the diagnostic performance of FTIR spectroscopy in a population of 40 patients with HCC and 39 patients without HCC. In this study, the diagnostic accuracy rate was 82 to 86%. In a second step, an FTIR study on a larger number of patients was performed to validate the results obtained in the pilot studiey. FTIR spectral characteristics of 308 serum from cirrhotic patients with HCC were compared with those of 509 cirrhotic patients without HCC. The supervised classification methods, SVM and PLS -DA were applied but did not confirm the results obtained in the pilot study. The diagnostic accuracy was between 50 and 60%, FTIR spectral analysis of whole serum does not appear discriminant enough to differentiate cirrhotic patients with and without HCC. This result highlights the need to confirm on a large number of patients results in pilot studies. Spectral analysis of serum fractions could be an alternative to more effectively identify diagnostic markers avoiding overlapping spectral information related to the complex composition of whole serum.

D. Tech. (Food Service Management, Dept. of Hospitality, Faculty of Human Sciences)|cVaal University of Technology / Main Purpose of the study: To evaluate the impact of soy protein feeding intervention over a period of six months on the nutritional status of an elderly (≥60 years old) community of Sharpeville, in which poverty, household food security and malnutrition were prevalent. Methods: An experimental design that had no control group but a comparison between hypercholesterolaemic (HC) and normocholesterolaemic (NC) groups was used with 134 randomly selected elderly respondents. The first stage involved a baseline survey which determined the prevalence of risk factors for cardiovascular disease (CVD) and nutritional status among participants. Measurements included biochemical indices (serum lipids, vitamin B12, folate and homocysteine), anthropometry (weight, height and waist circumference) and dietary intake using 24h-recall and 7-day dietary diversity questionnaire. Socio-demographic information gathered from previous studies on the same subjects was used. The second stage was the preparation, formulation, and implementation of a nutrition education programme to assess its impact on nutrition knowledge after the nutrition education intervention. The nutrition education was conducted in two sections, namely an exploratory study and an experimental study. An exploratory study was conducted to assess the nutrition education needs of the elderly and was followed by the experimental study, which assessed nutrition knowledge before and after the intervention. The third stage was the implementation of the 10 grams soy protein daily feeding intervention for a period of six months and evaluation of its impact on risk factors for cardiovascular disease and on nutritional status. Sensory tests, compliance and the same measurements conducted at baseline were used at follow-up (feeding intervention). A comparison of the findings of the baseline study and follow-up study was conducted. Also to provide deeper insight into the effect of soy on the risk factors for CVD and nutritional status, respondents were further stratified into HC and NC groups based on their LDL-C levels at baseline study and results were also presented as such. The data analyses included descriptive statistics and t-tests on SPSS version 21.0. Results: From the baseline study, the dietary intake results revealed a poor dietary intake which contributed to inadequate estimated average requirements (EAR) and adequate intakes (AI) of nutrients. A mainly carbohydrate-based diet was consumed with minimal intake of dairy and legumes despite a medium dietary diversity score. The anthropometric indices at baseline indicated over-nutrition based on the reported waist circumference 97.32±10.32 (80.6%) above substantial risk of CDL, obesity (75.3%) and hypertension (56.7%), with the highest percentages for both waist circumference of substantial risk and overweight/obesity found among the women (80.9% and 79.9% respectively) and for hypertension among the men (79.1%). For the biochemical results at baseline, the prevalence of risk factors for CVD was observed as abnormal mean serum lipids such as LDL-cholesterol (3.6±1.1), HDL-cholesterol (0.73±0.4), total cholesterol:HDL-cholesterol ratio (7.9±2.9), triglyceride:HDL-cholesterol ratio (2.7±2.1) and homocysteine (17.1±9.2) in the total group. The women had high TC (5.2±1.1) indicating borderline risk of CVD as compared with men who had lower TC (4.5±0.8) and this was significantly different (p=0.049). The nutrition education programme was effective in increasing knowledge with an improvement of 14.5 percent from pre- (62.3%) to post-test (76.8%) for the total group which was statistically significant (p=0.000). The results for the soy protein feeding intervention, the dietary intake for the total group indicated a statistically significant decrease in energy intake (p=0.001), by about 20.4 percent form baseline to follow-up, while energy intake at baseline was already below the EAR. Also a statistically significant decrease was seen from baseline to follow-up for total dietary fat (p=0.004), cholesterol (p=0.008) and animal protein (p=0.000), with a statistically significant increase only on dietary folate (p=0.001) and iron (0.001). These dietary changes were also observed for the HC and NC groups after the intervention with only fat not decreasing significantly for the HC group. For the anthropometry indices, and hypertension no significant impact after the intervention for the total group and also for the HC and NC groups was observed. The biochemical results indicated a beneficial effect of the soy-based products on the following serum lipids: a significant improvement in LDL-C (p=0.000), HDL-C (p=0.000) and TC:HDL ratio (p=0.000) for the HC group while only TC:HDL ratio showed a significant improvement for the NC group after the intervention. However, high risk factors for CVD in this elderly group were still observed, with a significant decrease after the intervention of serum folate (p=0.000) below the recommended level and a significant increase in homocysteine (p=0.000) above the recommended level. Significant differences between the HC and NC groups were seen in TC, LDL-C, LDL:HDL-C ratio and TC:HDL-C ratio at the beginning of the intervention (baseline). However, at the end of the intervention (follow-up), significant differences were observed only in TC, LDL-C and homocysteine. Conclusion: Although the energy intake reduced significantly, only three of the micro-nutrients (pantothenate, Niacin and selenium) had a significant decrease between baseline and follow-up. Therefore the nutritional status of these elderly was not affected as it was also observed that there was no significant impact on anthropometric indices that took place. However this intervention had a significant impact on iron intake, which was one of the deficiencies identified amongst this elderly people from previous study. Also the nutrition education and a daily consumption of at least 10g of soy had a significant beneficial effect on LDL-C, HDL-C and TC:HDL ratio for the HC groups, thus reducing risk of CVD. Although soy had a beneficial effect on blood lipid profile no effect on hypertension was observed. The guideline of a 25g intake of soy should be encouraged as recommended by FDA as an effective cholesterol-lowering food item.

<p>Rapporten laddas upp av lärare om detta godkänns av handledare.</p>

Estudos anteriores mostram que o polímero Nafion® pode causar deslocamento do equilíbrio conformacional de proteínas em valores de pH que não o fisiológico. Nesse sentido, o Nafion® não só pode ser utilizado como uma sonda interessante para estudos estruturais de proteínas, mas, também, é importante entender seu papel na conformação da proteína. Portanto, a Albunina do Soro Bovino (BSA) foi escolhida como modelo para o estudo dos efeitos do Nafion® na conformação helicoidal de proteínas. A finalidade deste trabalho é entender as alterações na conformação e vizinhanças aromáticas da BSA, na faixa de pH de 2 a 12, na presença e ausência de Nafion®, que pode também revelar o papel do polímero na exposição dos aromáticos e nos processos de transferência de energia. As alterações da estrutura secundária foram medidas por Dicroísmo Circular e os espectros de fluorescência no estado estacionário foram usados para analisar as mudanças nas vizinhanças dos aromáticos. Os resultados mostraram a diminuição discreta do conteúdo helicoidal da conformação da BSA na região extremamente básica, pH 11 em relação à conformação em pH 7. Já na região ácida, pH 2, embora haja considerável diminuição do conteúdo helicoidal, a BSA ainda mantém quase 50% de sua conformação secundária regular. Em relação aos ambientes dos aromáticos triptofano e tirosina, a eficiência quântica da emissão de fluorescência diminui em regiões ácidas e básicas, indicando que, nessas estruturas, os aromáticos encontram-se em restrição conformacional em relação ao observado na proteína nativa. Estes resultados apontam para a mudanças na conformação da BSA em ambas as regiões: ácidas e básicas, incluindo mudanças das estruturas secundárias e nas vizinhanças dos aromáticos. A adição do Nafion®, por outro lado, acentua o deslocamento para o azul e diminuição da exposição dos aminoácidos, tanto em solução quanto em estado sólido. A estrutura secundária da proteína é completamente modificada pelo polímero na região ácida, e esta conformação é mantida nas regiões neutra e básica, sugerindo que o Nafion® não estabiliza estruturas helicoidais / Previous studies have shown that Nafion® can disturb the conformational equilibrium of some proteins when at pH other than physiological ones. In this sense, Nafion® can used to study protein conformation, but is also important to understand its interaction with the proteins. In this work, Bovine Serum Albimun (BSA) was chosen as a model to understand the modifications caused by Nafion® at helicoidal proteins conformation. More specifically, the aim encloses the understanding of changes in BSA secondary conformation and aromatic vicinities, at pH range from 2 to 12, in the Nafion®s presence and absence. Secondary changes were measured by Circular Dichroism and steady-state fluorescence was used to study the aromatic vicinities. Results have shown small differences at helix content in the extremely basic pH (pH 11) when compared to BSA conformation at pH 7 (native one). At pH 2, on the other hand, although a decreasing in helical content was observed, BSA was able to keep almost 50% of secondary regular conformation. Regarding the aromatic vicinities (tryptophans and tyrosines) the fluorescence emission quantum eficience decreased in both regions (acid and basic), suggesting that the aromatics in these conformations are found in a more restrict environment. Nafion®, when added, promoted a decreasing in aromatic exposition, both in solution and solid state, while the secondary structure is completelu modified by its presence in all pH range, suggesting that helical conformations are not stabilized by Nafion®