An early stage in T4-induced hyperthyroidism is related to systemic oxidative stress but does not influence the pentose cycle in erythrocytes and systemic inflammatory status

ABSTRACT Objective Hyperthyroidism causes many injuries in its target organs and the consequences are reflected systemically. As systemic alterations in hyperthyroidism at earlier stages have received partial attention, this study aimed to investigate systemic redox and inflammatory status at an early stage of T4-induced hyperthyroidism. Materials and methods Male Wistar rats were assigned to control and hyperthyroid groups (n = 7/group). The hyperthyroid group received L-thyroxine (12 mg/L) in their drinking water for 14 days whereas control group received only the vehicle. Body weight was measured on the 1st and 14th day of the protocol. On the 14th day, animals were anaesthetized. Blood was then collected from the retro-orbital venous plexus and then the animals were euthanised. The blood was separated into plasma and erythrocytes. Plasma was used to measure ROS levels, sulfhydryl compounds, IL-10, TNF-α and LDH levels; erythrocytes were used for the analysis of thioredoxin reductase activity, glutaredoxin content, and pentose cycle enzymes (total G6PD, G6PD and 6PGD). Results Hyperthyroid animals presented body weight gain and final body weight reduction, which was associated with increased ROS levels and decreased sulfhydryl content in plasma. Thioredoxin reductase activity, glutaredoxin content, and pentose cycle enzymes levels in erythrocytes, as well as IL-10, TNF-α and LDH plasma levels were unaltered. Conclusion Taken together, our results suggest an impairment in corporal mass associated with systemic oxidative stress at this stage of hyperthyroidism. Meanwhile, the pentose cycle was not influenced and systemic inflammation and tissue damage seem to be absent at this stage of hyperthyroidism.

The isolation of pentose-assimilating yeasts and their xylose fermentation potential

ABSTRACT For the implementation of cellulosic ethanol technology, the maximum use of lignocellulosic materials is important to increase efficiency and to reduce costs. In this context, appropriate use of the pentose released by hemicellulose hydrolysis could improve de economic viability of this process. Since the Saccharomyces cerevisiae is unable to ferment the pentose, the search for pentose-fermenting microorganisms could be an alternative. In this work, the isolation of yeast strains from decaying vegetal materials, flowers, fruits and insects and their application for assimilation and alcoholic fermentation of xylose were carried out. From a total of 30 isolated strains, 12 were able to assimilate 30 g L-1 of xylose in 120 h. The strain Candida tropicalis S4 produced 6 g L-1 of ethanol from 56 g L-1 of xylose, while the strain C. tropicalis E2 produced 22 g L-1 of xylitol. The strains Candida oleophila G10.1 and Metschnikowia koreensis G18 consumed significant amount of xylose in aerobic cultivation releasing non-identified metabolites. The different materials in environment were source for pentose-assimilating yeast with variable metabolic profile.

Perfil histoenzimológico do carcionoma mamário e sua correlaçäo com o percentual da cromatina sexual tumoral: I.Histoquímica do metabolismo das pentoses e da glicólise nos tecidos mamários näo neoplásico e neoplásico / Histoenzymologic profile of mammary carcinoma and its correlation with the percentual of tumor sex chromatin: I.Histochemistry of pentoses metabolism and glycosis of non-neoplastic and neoplastic mammary tissue

Estudaram-se em 15 biópsias mamárias (seis biópsias provenientes de mamas com hipertrofia, uma com displasia e oito de mamas carcinomatosas) as atividades enzimáticas relacionadas com os metabolismos das pentoses e da glicólise. No que diz respeito ao tecido näo neoplásico (com exclusäo do caso displásico), observou-se pouca atividade das vias das pentoses e da glicólise tanto no epitélio, quanto no estroma. Nos tecidos provenientes de mamas carcinomatosas, detectamos forte atividade da via das pentoses no epitélio, com tendência a aumentar de intensidade à medida que a neoplasia tornava-se mais indiferenciada e forte atividade da via glicolítica, comportamento assemelhado ao da via das pentoses. Näo foram observadas diferenças do ponto de vista histoenzimológico quer os casos fossem cromatina-positivos (corpúsculos de Barr > ou = 15%) ou negativos