Effect of Swimming at Low Temperature on Uncoupling Protein Gene Expression in Skeletal Muscle of Wistar Rats / Efecto de la Natación a Baja Temperatura sobre la Expresión del Gen de la Proteína de Desacoplamiento en el Músculo Esquelético de Ratas Wistar

SUMMARY: As the economy develops and living standards improve, overweight and obesity are increasingly prevalent. Currently, weight-loss medications are primarily administered orally or intravenously, which can result in poor targeting, low bioavailability, frequent administration, and high toxicity and side effects. The study aimed to address these challenges by preparing polylactic acid- polyethylene glycol staple fibers that carry the browning drug pioglitazone hydrochloride using electrostatic spinning and freeze-cutting techniques. Animal experiments were conducted to test the effectiveness of these fibers. Additionally, the study investigated the expression of uncoupling protein genes in rats exposed to different water temperatures by measuring changes in serum urea nitrogen and mRNA expression levels of skeletal muscle uncoupling protein genes. The physiological and genetic effects of low-temperature swimming exercise on changes in energy metabolism in rats were also analyzed at both the individual and molecular levels. The results revealed that serum urea nitrogen remained more stable in hypothermic swimming rats compared to rats in the swimming group. Furthermore, the study observed an induced up-regulation of uncoupling proteins in the skeletal muscle of Wistar rats in response to external temperature stimulation, and the expression of mRNA for skeletal muscle uncoupling proteins significantly increased as the temperature decreased. And the prepared short nanofibers also had a significant promotive effect on uncoupling protein gene, COX7A1, while suppressing the expression of lipogenic gene.

A medida que la economía se desarrolla y los niveles de vida mejoran, el sobrepeso y la obesidad son cada vez más frecuentes. Actualmente, los medicamentos para bajar de peso se administran principalmente por vía oral o intravenosa, lo que puede resultar en una mala focalización, baja biodisponibilidad, administración frecuente y alta toxicidad y efectos secundarios. El estudio tuvo como objetivo abordar estos desafíos mediante la preparación de fibras cortadas de ácido poliláctico y polietilenglicol que transportan el fármaco pardo clorhidrato de pioglitazona mediante técnicas de hilado electrostático y liofilización. Se realizaron experimentos con animales para probar la eficacia de estas fibras. Además, el estudio investigó la expresión de genes de proteínas desacopladoras en ratas expuestas a diferentes temperaturas del agua midiendo los cambios en el nitrógeno ureico sérico y los niveles de expresión de ARNm de genes de proteínas desacopladoras del músculo esquelético. También se analizaron los efectos fisiológicos y genéticos del ejercicio de natación a baja temperatura sobre los cambios en el metabolismo energético en ratas, tanto a nivel individual como molecular. Los resultados revelaron que el nitrógeno ureico sérico permaneció más estable en ratas nadadoras hipotérmicas en comparación con las ratas del grupo de natación. Además, el estudio observó una regulación positiva inducida de las proteínas desacopladoras en el músculo esquelético de ratas Wistar en respuesta a la estimulación de la temperatura externa, y la expresión de ARNm para las proteínas desacopladoras del músculo esquelético aumentó significativamente a medida que disminuía la temperatura. Además, las nanofibras cortas preparadas también tuvieron un efecto promotor significativo sobre el gen de la proteína de desacoplamiento, COX7A1, al tiempo que suprimieron la expresión del gen lipogénico.

Modulation of Phospholipase A2 Membrane Activity by Anti-inflammatory Drugs.

The phospholipase A2 (PLA2) superfamily consists of lipolytic enzymes that hydrolyze specific cell membrane phospholipids and have long been considered a central hub of biosynthetic pathways, where their lipid metabolites exert a variety of physiological roles. A misregulated PLA2 activity is associated with mainly inflammatory-derived pathologies and thus has shown relevant therapeutic potential. Many natural and synthetic anti-inflammatory drugs (AIDs) have been proposed as direct modulators of PLA2 activity. However, despite the specific chemical properties that these drugs share in common, little is known about the indirect modulation able to finely tune membrane structural changes at the precise lipid-binding site. Here, we use a novel experimental strategy based on differential scanning calorimetry to systematically study the structural properties of lipid membrane systems during PLA2 cleavage and under the influence of several AIDs. For a better understanding of the AIDs-membrane interaction, we present a comprehensive and comparative set of molecular dynamics (MD) simulations. Our thermodynamic results clearly demonstrate that PLA2 cleavage is hindered by those AIDs that significantly reduce the lipid membrane cooperativity, while the rest of the AIDs oppositely tend to catalyze PLA2 activity to different extents. On the other hand, our MD simulations support experimental results by providing atomistic details on the binding, insertion, and dynamics of each AID on a pure lipid system; the drug efficacy to impact membrane cooperativity is related to the lipid order perturbation. This work suggests a membrane-based mechanism of action for diverse AIDs against PLA2 activity and provides relevant clues that must be considered in its modulation.

Feeding Strategies and Trophic Niche Divergence of Three Groups of Dosidicus gigas off Peru: Based on Stable Carbon and Nitrogen Isotopes and Morphology of Feeding Apparatuses.

Dosidicus gigas (D. gigas) is a pelagic cephalopod of ecological and economic importance widely distributed in the eastern Pacific Ocean. Generally, small-, medium-, and large-sized groups of the squids have been respectively identified on the basis of the mantle length (ML) of adults. Intraspecific feeding variability maximizes the utilization of available food resources by D. gigas. However, the coexistence mechanism of three groups has not been fully understood yet. In our study, based on the analyses of beak morphology and stable carbon and nitrogen isotopes, the feeding strategies and coexistence patterns of large-, medium-, and small-sized groups of D. gigas were investigated. D. gigas had a wide range of 13C/12C (δ13C) and 15N/14N (δ15N) values in muscle tissue, variable feeding behaviors, and wide food sources. The δ13C or δ15N values showed no significant difference between the small- and medium-sized groups, which shared the same habitats and fed on preys with the similar trophic level. Compared to small- and medium-sized groups, the large-sized group had a smaller range of habitats and consumed more nearshore foods. Both isotopes and feeding apparatus morphology indicated a high degree of niche overlap between the small- and medium-sized groups, whereas the large-sized group differed significantly from other groups. In addition, the niche width of the female was larger than that of the male in all three groups. We inferred that the sex differences in body length and reproductive behavior led to the difference in niche width. The isotopic niche overlap between female and male samples was the most significant in large-sized group and the least significant in the small-sized group, indicating that different feeding strategies were adopted by the three groups. These findings proved that the three groups of D. gigas off Peruvian waters adopted a feeding strategy with inter- and intra-group regulation. This feeding strategy maximizes the use of food and habitat resources and ensures that different size groups can coexist in the same waters.

Analysis of a vector-bias malaria transmission model with application to Mexico, Sudan and Democratic Republic of the Congo.

Malaria is a deadly disease transmitted to human through the bite of infected female mosquitoes. The aim of this paper is to study the different vector-bias values between low and high transmission areas with the examples of Mexico (low) and Sudan, Democratic Republic of the Congo (Congo, DR) (high) during malaria transmission. We develop a malaria transmission model with vector-bias and investigate the basic reproduction number, the existence of equilibria and the corresponding globally asymptotically stable. Then, we simulate the reported cases of Mexico and Sudan, Democratic Republic of the Congo by World Health Organization (WHO) (WHO, 0000) and predict the direction of the disease. Our simulation results show that the most endemic country is Congo, DR with the highest vector-bias and R0 values, followed by Sudan and Mexico with less, respectively and that the disease will die out in Mexico and persist in Sudan and Congo, DR. Furthermore, we perform sensitivity analysis of R0 and give some useful comments on reducing the cases of the disease.

Waste electrical and electronic equipment management and Basel Convention compliance in Brazil, Russia, India, China and South Africa (BRICS) nations.

Brazil, Russia, India, China and South Africa (BRICS) nations account for one-quarter of the world's land area, having more than 40% of the world's population, and only one-quarter of the world gross national income. Hence the study and review of waste electrical and electronic equipment management systems in BRICS nations is of relevance. It has been observed from the literature that there are studies available comparing two or three country's waste electrical and electronic equipment status, while the study encompassing the BRICS nations considering in a single framework is scant. The purpose of this study is to analyse the existing waste electrical and electronic equipment management systems and status of compliance to Basel convention in the BRICS nations, noting possible lessons from matured systems, such as those in the European Union EU) and USA. The study introduced a novel framework for a waste electrical and electronic equipment management system that may be adopted in BRICS nations and revealed that BRICS countries have many similar types of challenges. The study also identified some significant gaps with respect to the management systems and trans-boundary movement of waste electrical and electronic equipment, which may attract researchers for further research.