Exercise fatigue injury under sport resistance / Lesão de fadiga causada por exercício sob resistência esportiva / Lesión por fatiga causada por ejercicio bajo resistencia deportiva

ABSTRACT Introduction Athletes are prone to local muscle fatigue due to high-intensity training and to long-term accumulation of musculoskeletal injuries. Musculoskeletal complications represent a large proportion of occupational health problems and, for this reason, have received increased attention from the sports industry. In this sense, studies on muscle fatigue should be intensified. Objective Verify muscle fatigue and injury involving the strain characteristics of lower limb joints in the eccentric and centripetal contraction of the jump. Methods A total of 691 individuals aged 20 to 40 years were selected. Fatigue was caused by active muscle contraction. The characteristic curves of active muscle contraction in different isometric, isotonic, and isokinetic training were analyzed. The degree of fatigue caused by three different sports states was tested by experimentation. The corresponding active muscle contraction characteristics were also analyzed. The potential for homeostasis at different ages was compared. Results The delay in recovery to fatigue is directly proportional to the athlete's age. The return to post-exercise relief proportion from fatigue gradually decreases. Conclusion The experimental results showed that active muscle contraction could reduce exercise fatigue to some extent. This beneficial biochemical property of active muscle contraction is not found in people with advanced age. The findings have a guiding potential for the relief of sports fatigue. Evidence Level II; Therapeutic Studies - Investigating the result.

RESUMO Introdução Os esportistas estão propensos à fadiga muscular local devido ao treinamento de alta intensidade, e ao acúmulo de lesões musculoesqueléticas a longo prazo. As complicações musculoesqueléticas representam uma grande fatia dos problemas de saúde ocupacional e por isso têm recebido maior atenção da indústria esportiva. Nesse sentido, os estudos sobre a fadiga muscular devem ser aprofundados. Objetivo Verificar a fadiga e lesão muscular envolvendo as características de esforço das articulações dos membros inferiores na contração excêntrica e contração centrípeta do salto. Métodos Foram selecionados 691 indivíduos com idade entre 20 a 40 anos. A fadiga foi ocasionada por contração muscular ativa. Foram analisadas as curvas características da contração muscular ativa em diferentes estados nos treinos isométrico, isotônico e isocinético. O grau de fadiga causado por três estados esportivos diferentes foi testado através de experimentos. Também foram analisadas as características de contração muscular ativa correspondentes. O potencial de homeostase em diferentes idades foi comparado. Resultados O retardo na recuperação à fadiga é diretamente proporcional a idade do esportista. A proporção de retorno ao alívio pós-exercício sobre a fadiga diminui gradualmente. Conclusão Os resultados experimentais mostram que a contração muscular ativa pode reduzir até certo ponto a fadiga ao exercício. Os efeitos dessas propriedades bioquímicas benéficas da contração muscular ativa não são encontrados em pessoas com idade avançada. Os achados tem um potencial orientador para o alívio da fadiga esportiva. Nível de evidência II; Estudos Terapêuticos - Investigação de Resultados.

RESUMEN Introducción Los deportistas son propensos a la fatiga muscular local debido al entrenamiento de alta intensidad, y a la acumulación de lesiones musculoesqueléticas a largo plazo. Las complicaciones musculoesqueléticas representan una gran parte de los problemas de salud laboral y por ello han recibido una mayor atención por parte de la industria del deporte. En este sentido, hay que profundizar en los estudios sobre la fatiga muscular. Objetivo Verificar la fatiga muscular y las lesiones que implican las características de esfuerzo de las articulaciones de los miembros inferiores en la contracción excéntrica y centrípeta del salto. Métodos Se seleccionaron 691 individuos de entre 20 y 40 años. La fatiga fue causada por la contracción muscular activa. Fueron analizadas las curvas características de la contracción muscular activa en diferentes estados en el entrenamiento isométrico, isotónico e isocinético. El grado de fatiga provocado por tres estados deportivos diferentes se comprobó mediante experimentos. También se analizaron las correspondientes características de la contracción muscular activa. Se comparó el potencial de homeostasis a diferentes edades. Resultados El retraso en la recuperación a la fatiga es directamente proporcional a la edad del deportista. La proporción de retorno al alivio de la fatiga después del ejercicio disminuye gradualmente. Conclusión Los resultados experimentales muestran que la contracción muscular activa puede reducir la fatiga del ejercicio en cierta medida. Los efectos de estas propiedades bioquímicas beneficiosas de la contracción muscular activa no se encuentran en las personas mayores. Los hallazgos tienen un potencial orientador para el alivio de la fatiga deportiva. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados.

FSH receptor binding inhibitor up-regulates ARID1A and PTEN genes associated with ovarian cancers in mice

Experiments were conducted to determine if the follicle-stimulating hormone (FSH) receptor binding inhibitor (FRBI) impacts the expression levels of AT-rich interactive domain-containing protein 1A (ARID1A) and phosphatase and tensin homolog (PTEN) in ovaries and blood, as well as expressions of follicle-stimulating hormone cognate receptor (FSHR) gene and proteins. Mice in FRBI-10, FRBI-20, FRBI-30, and FRBI-40 groups were intramuscularly injected with 10, 20, 30, and 40 mg FRBI/kg, respectively, for five consecutive days. Western blotting and qRT-PCR were utilized to determine expression levels of ARID1A and PTEN proteins and mRNAs. Serum ARID1A and PTEN concentrations of the FRBI-40 group were higher than the control group (CG) and FSH group (P<0.05). FSHR mRNA levels of FRBI-20, FRBI-30, and FRBI-40 groups were lower than that of CG and FSH groups on day 15 (P<0.05 or P<0.01). Expression levels of FSHR proteins of FRBI-30 and FRBI-40 groups were lower than those of CG and FSH groups (P<0.05). Levels of ARID1A and PTEN proteins of the FRBI-30 group were greater than CG on days 20 and 30 (P<0.05). FRBI doses had significant positive correlations to levels of ARID1A and PTEN proteins. Additionally, ARID1A and PTEN had negative correlations to FSHR mRNAs and proteins. A high dose of FRBI could promote the expression levels of ARID1A and PTEN proteins in ovarian tissues. FRBI increased serum concentrations of ARID1A and PTEN. However, FRBI depressed expression levels of FSHR mRNAs and proteins in mouse ovaries.

FSH receptor binding inhibitor restrains ovarian cancer through down-regulating expression levels of FSHR and ERβ in mice

Follicle stimulating hormone receptor is used as an imaging biomarker for the detection of ovarian cancer (OC). Inhibiton of FSHR may attenuate the carcinogenesis particularly epithelial ovarian cancer. Here we investigated FSH receptor binding inhibitor (FRBI) effects on the follicular development, to explore their impact on expressions of FSH receptor (FSHR) and estrogen receptor b (ERβ) proteins in the ovaries. 150 female mice were assigned to FRBI+FSH (COM) group, FSH group, and control group (CG). Mice in COM-1, COM-2, and COM-3 groups were intramuscularly injected with 500, 750 and 1000 μg FRBI combined with 10 IU FSH for five consecutive days. The results showed that the numbers of secondary follicles (SF) in FSH group were increased. SF numbers of three COM groups were gradually declined as the FRBI doses rose. SF numbers of COM-2 and COM-3 groups were less than the FSH group on day 20 (P <0.05). Ovarian cortex thicknesses (OCT) of COM-3 group was less than that FSH group (P <0.05). Maximum longitudinal diameter (MLD) and transverse diameter (MTD) of SFs in three COM groups were dose-dependently decreased. FSHR protein levels of COM groups were significantly decreased as compared to FSH group (P <0.05). ERβ protein levels of COM-1 and COM-2 were less than the FSH group (P <0.05). Summarily, FRBI could reduce OCT and follicle numbers, suppress follicular development, decrease expression of ovarian ERβ and FSHR protein.

Correlations of Four Genetic Single Nucleotide Polymorphisms in Brain-Derived Neurotrophic Factor with Posttraumatic Stress Disorder

OBJECTIVE: To investigate the correlations of four genetic single nucleotide polymorphisms (SNPs) of brain-derived neurotrophic factor (BDNF) with posttraumatic stress disorder (PTSD). METHODS: A total of 300 patients with sporadic PTSD and 150 healthy subjects (the control group) were selected according to the diagnostic criteria of PTSD (DSM-IV), and the genotypes of the BDNF SNPs G-712A, C270T, rs6265, and rs7103411 were detected by polymerase chain reaction and direct DNA sequencing to determine intergroup differences in the genotypes and allele frequencies; the p values were corrected with the permutation test. RESULTS: The genotypes and allele frequencies of the SNPs G-712A, rs6265, and rs7103411 of BDNF showed no significant intergroup differences (p>0.05). However, the genotype and allele frequencies of C270T showed significant differences between the PTSD group and the control group (p<0.05). CONCLUSION: The SNP C270T of BDNF may be associated with PTSD. Individuals carrying the polymorphic T allele of C270T may be more likely to suffer from PTSD.