Although estradiol (E2) has been believed to be the most critical factor in the menopause-associated decrease in bone mineral density (BMD), the role of increasing follicle stimulating hormone (FSH) during menopause is relatively unclear. We determined the extent to which hip and lumbar spine BMD differ among the stages of menopause in healthy women, and whether BMD is associated with FSH and E2 levels. A cross-sectional study of 141 healthy women classified as premenopausal (Pre; 38 ± 6 yrs; mean ± SD, n = 30), early perimenopausal (EPeri; 50 ± 3yrs, n = 31), late perimenopausal (LPeri; 50 ± 4yrs, n = 30), early postmenopausal (EPost; 55 ± 3yrs, n = 24), or late postmenopausal (LPost; 62 ± 4 yrs, n = 26), was conducted. Spine/hip BMD and sex hormones were measured using dual-energy X-ray absorptiometry and enzymatic/colorimetric methods, respectively. Compared to EPeri, spine BMD was lower (p < 0.05) in LPeri, EPost, and LPost and hip BMD was lower (p < 0.05) in EPost and LPost. BMD was inversely associated with FSH (spine: r = −0.341; hip: r = −0.271, p < 0.05) and directly associated with E2 (spine: r = 0.274; hip: r = 0.256, p < 0.05). The menopause-related loss of spine and hip BMD is associated not only with low E2 but also higher FSH. Future studies are essential to delineating the mechanisms by which FSH regulates bone health in aging women.
24 June 2024 in Progress in Neuro-Psychopharmacology and Biological Psychiatry
The effects of the manufacturing process and the regeneration of Shirasu porous glass (SPG) membranes were investigated on the reproducibility of protein precipitants, termed protein microbeads. Intravenous immunoglobulin (IVIG) was selected as a model protein to produce its microbeads in seven different cases. The results showed that the hydrophobically modified SPG membrane produced finer microbeads than the hydrophilic SPG membrane, but this was inconsistent when using the general regeneration method. Its reproducibility was determined to be mostly dependent on rinsing the SPG membrane prior to the modification and on the protein concentration used for emulsification. The higher concentration could foul and plug the membrane during protein release and thus the membrane must be washed thoroughly before hydrophobic modification. Moreover, the membrane regenerated by silicone resin dissolved in ethanol had better reproducibility than silicone resin dissolved in water. On the other hand, rinsing the protein precipitant with cold ethanol after the emulsification was not favorable and induced protein aggregation. With the addition of trehalose, the purity of the IVIG microbeads was almost the same as before microbeadification. Therefore, the regeneration method, protein concentration, and its stabilizer are key to the success of protein emulsification and precipitation using the SPG membrane.
PURPOSE: Genes had selectively evolved to enhance the motivation for physical movement in human during the Paleolithic era. To prepare for a potential forthcoming food deficiency, high physical activity was essential for survival in the environment where hunting wild animals and gathering plants. In modern society, however, developing technology and engineering has made human life easier to accomplish tasks with not much movement and effort, resulting in a profound deficiency in physical activity (i.e., physical inactivity).METHODS: In this review, the authors summarized previous studies searched by the PubMed, Google Scholar, and Science Direct databases.RESULTS: Reduced physical activity is significantly associated with the high prevalence of various diseases including metabolic syndrome, obesity, sarcopenia, and cancer. Unfortunately, in women, menopause negatively impacts their body and physiology mainly due to the loss of estrogens, which also contributes to behavioral changes such as a significant reduction of physical activity levels during menopausal transition. In this review, the author focused to describe the underlying brain mechanism by which menopause results in reduced levels of physical activity through estrogens, estrogen receptors, and dopamine signaling in the nucleus accumbens, the main controller for exercise motivation.CONCLUSIONS: Estrogen receptor, specifically ERα, and dopamine receptors are the main controllers for voluntary physical activity. Furthermore, high running motivation is associated with enhanced dopamine activity. More studies are needed to verify whether enhanced dopamine activity can protect against menopause-associated reduction in physical activity.