Current Understanding of Human Polymorphism in Selenoprotein Genes: A Review of Its Significance as a Risk Biomarker

Selenium has been proven to influence several biological functions, showing to be an essential micronutrient. The functional studies demonstrated the benefits of a balanced selenium diet and how its deficiency is associated with diverse diseases, especially cancer and viral diseases. Selenium is an antioxidant, protecting the cells from damage, enhancing the immune system response, preventing cardiovascular diseases, and decreasing inflammation. Selenium can be found in its inorganic and organic forms, and its main form in the cells is the selenocysteine incorporated into selenoproteins. Twenty-five selenoproteins are currently known in the human genome: glutathione peroxidases, iodothyronine deiodinases, thioredoxin reductases, selenophosphate synthetase, and other selenoproteins. These proteins lead to the transport of selenium in the tissues, protect against oxidative damage, contribute to the stress of the endoplasmic reticulum, and control inflammation. Due to these functions, there has been growing interest in the influence of polymorphisms in selenoproteins in the last two decades. Selenoproteins' gene polymorphisms may influence protein structure and selenium concentration in plasma and its absorption and even impact the development and progression of certain diseases. This review aims to elucidate the role of selenoproteins and understand how their gene polymorphisms can influence the balance of physiological conditions. In this polymorphism review, we focused on the PubMed database, with only articles published in English between 2003 and 2023. The keywords used were "selenoprotein" and "polymorphism". Articles that did not approach the theme subject were excluded. Selenium and selenoproteins still have a long way to go in molecular studies, and several works demonstrated the importance of their polymorphisms as a risk biomarker for some diseases, especially cardiovascular and thyroid diseases, diabetes, and cancer.

Comparison between two methods to evaluate temperature changes produced by composite light curing units and polymerization techniques

AIM

This study evaluated the temperature change into the pulp chamber during the light curing of composite resin by direct (bovine tooth) and indirect (matrix) methods.

METHODS

Direct method: fifty standardized cavities (2x2x2 mm) were prepared in bovine incisors, which were randomly assigned to evaluation of the temperature changes in the pulp chamber. Indirect method: temperature changes were evaluated through a dentine slice of 1.0 mm thickness in a elastomer cubic mold (2x2x2 mm). Filtek Z250 composite resin (3M/ESPE) was photo-activated using three light curing units: quartz-tungsten-halogen (QTH) by continuous, soft-start or intermittent light modulations; light emitting diode (LED); and plasma arc-curing (PAC). Ten groups (N.=10) were established according to technique evaluation and photo-activation methods. All experiments were carried out in a controlled environment (37 °C and 50 ± 10% relative humidity). The temperature changes were recorded using a digital thermometer attached to a type-K thermocouple in contact with the dentin slice (indirect method) or in contact with the axial wall (dentin) of pulp chamber (direct method). The results were submitted to ANOVA and Tukey's test (α=0.05).

RESULTS

Temperature changes were statistically higher for the matrix indirect method (2.56 ºC) than bovine teeth direct method (1.17ºC). The change temperature was statistically higher for the PAC (1.77 ºC) when compared to other photo-activation modes in bovine teeth direct method.

CONCLUSION

The two methods of temperature evaluation were different, however indirect method detected the higher temperature increase. Higher energy density arising from the light curing units and polymerization techniques promoted higher temperature increase.

Hemangioma esplênico e Síndrome de Kasabach-Merritt como diagnóstico diferencial de massa abdominal do recém-nascido

Apresentamos um caso raro de hemangioma esplênico em um recém-nascido do sexo feminino, apresentando-se como massa abdominal, coagulopatia e trombocitopenia. No ato operatório observou-se uma massa tumoral vascular do pólo inferior do baço. A paciente encontra-se em acompanhamento ambulatorial. O diagnóstico e as opções de tratamento foram revistas e discutidas. Os autores revisaram a literatura sobre hemangioma esplênico em recém-nascidos e observaram ser este o terceiro caso de associação entre hemangioma esplênico e síndrome de Kasabach-Merritt. O hemangioma esplênico é uma doença rara no diagnóstico diferencial das massas abdominais em recémnascidos. O hemangioma é a neoplasia benigna mais freqüente do baço. A anemia, a trombocitopenia e a coagulopatia são vistos com freqüência em hemangiomas cavernosos grandes associados à Síndrome de Kasabach-Merritt (KMS). O hemangioma cavernoso esplênico associado com esta síndrome é extremamente raro.

Survival rates and sex ratio of bovine IVE embryos frozen at different developmental stages on day 7

Two experiments were designed to determine the effects of stage of development on Day 7 of in vitro-produced bovine embryos on survival after deep freezing and on sex ratio. Bovine IVF embryos and bovine oviductal epithelial cells (BOEC) were co-cultured in TCM-199 and, on Day 7 after insemination (Day 0), were morphologically evaluated and divided into groups by developmental stage. In Experiment 1, embryos classified as early blastocysts, blastocysts and full-expanding blastocysts were randomly subdivided into 2 groups by replicate: 50% of the embryos were placed immediately in a new BOEC co-culture (fresh group), while the other 50% were frozen, thawed and placed in a new BOEC co-culture (frozen/thawed group). Embryos were frozen in 1.5 M glycerol using a standard slow cooling technique. Fresh and frozen/thawed embryos were compared for survival rate (embryos hatching/hatched) in BOEC co-culture over the following 3 d (i.e., Days 7 to 10). The overall survival of the 425 embryos (early to full-expanding blastocysts) was 33% and was not different between fresh (35%) and frozen/thawed (30%) embryos. Survival of embryos cultured fresh or after freezing/thawing was higher for full-expanding blastocysts than for early blastocysts or for blastocysts, both of which were not different. In Experiment 2, all frozen/thawed embryos used in Experiment 1 plus all morulae and hatched blastocysts collected and frozen on Day 7 without regard to survival were sexed utilizing the polymerase chain reaction (PCR) technique. Sex of the embryos, by stage of development on Day 7, was determined in order to compare the rate of development in BOEC co-culture with the sex ratio (percentage of males). A total of 235 embryos was sex-determined with an overall percentage of males of 51%, which was not different from the expected 1:1 sex ratio. Both full-expanding blastocysts and hatched blastocysts had a significantly higher (P < 0.05) proportion of males (68 and 100%, respectively), while morulae had a significantly lower proportion of males (24%). Early blastocysts and blastocysts did not differ from a 1:1 sex ratio. The results indicate that male embryos develop faster in vitro than female embryos. The higher survival rate of full-expanding blastocysts after freezing/thawing, and the production of a higher number of males than females among embryos of this developmental stage suggest that a greater number of male fetuses may result from the successful freezing and transfer of in vitro-produced bovine embryos.