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.

Inhibitory Effect of Pentose on Biofilm Formation by Oral Bacteria

A number of bacterial species coexist in oral cavities as a biofilm rather than a planktonic arrangement. By forming an oral biofilm with quorum sensing properties, microorganisms can develop a higher pathogenic potential and stronger resistance to the host immune system and antibiotics. Hence, the inhibition of biofilm formation has become a major research issue for the future prevention and treatment of oral diseases. In this study, we investigated the effects of pentose on biofilm formation and phenotypic changes using wild type oral bacteria obtained from healthy human saliva. D-ribose and D-arabinose were found to inhibit biofilm formation, but have no effects on the growth of each oral bacterium tested. Pentoses may thus be good candidate biofilm inhibitors without growth-inhibition activity and be employed for the future prevention or treatment of oral diseases.

Improved spectrophotometric determination of disaccharides, hexoses and pentoses using aniline and its alkyl derivatives

Aniline and its alkyl derivatives in acetic acid media react with hexoses and pentoses to form colored products with characteristic absorption spectra. The spectral for individual hexoses, pentoses and their dehydration products and tend to vary with a given aniline derivative. The chromogen formed showed absorption at wavelength 530, 470 and 330mm. The method was improved and used to determine quantitatively glucoses, fructose, maltose, sucrose and ribose and the result obtained was found to obey Beer's law for a concentration range of [0.4-30mg mL-1] for glucose [0.2-2.2 mg.mL-1] for invert sugar [sucrose], [1-3,4mg.mL-1] for maltose under the specific condition that chosen for determination of each sugar

Pentose synthesis in glucose-grown cells of Lactobacillus casei.

The pathway of pentose synthesis in glucose-grown cells of Lactobacillus casei was ascertained. Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were present in glucose-grown cells, while transaldolase and transketolase were present only in traces. This suggested that only the oxidative arm of this pathway was operative in glucose-grown cells. On the other hand, in ribose-grown cells, transaldolase was induced with a concomitant suppression of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. These results were confirmed by the detection of labelled CO2 produced by L. casei grown on [1-14C]glucose. The activities of the enzymes of the oxidative pentose phosphate pathway as also the rate of CO2 formation were higher in the exponential phase of growth as compared to the stationary phase, when the requirement of the cells for pentoses for the formation of DNA and RNA was higher.

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