Effects of backhand stroke styles on bone mineral content and density in postmenopausal recreational tennis players: a cross-sectional pilot investigation.

BACKGROUND: One-handed backhand (OB) and two-handed backhand (TB) styles are commonly used in tennis, but only TB generates loadings on the non-dominant arm and a greater extension torque on the rear leg, leading to a greater axial torque involving rotation of the hip and trunk. The current study investigated whether those effects can further affect bone area (BA), bone mineral content (BMC) and density (BMD) in postmenopausal recreational tennis players. METHODS: BA, BMC and BMD of the lumbar spine, hip and distal radius were assessed using dual-energy X-ray absorptiometry in TB, OB, and swimmers' group as a control (SG) (all participants self-reported for at least 5 years of exercise history, n = 14 per group). Muscular strength was assessed with a hand dynamometer. Among these three groups, the BA, BMC and BMD of distal radius and muscle strength were assessed using one-way ANOVA, and those of the lumbar region and the hip joint were tested by one-way ANCOVA. RESULTS: TB showed higher BMC and BMD for both lumbar spine and femoral neck than SG (all, p < 0.05). Both OB and TB showed greater BMD inter-trochanter than SG (both, p < 0.05). OB demonstrated greater inter-arm differences in the distal radius, which involved 1/3 distal for BMC and mid-distal radius for BMD compared to the TB and SG (all, p < 0.05). In addition, greater inter-arm asymmetry of grip strength was found in OB compared to TB and SG (both, p < 0.05). CONCLUSION: For postmenopausal women, performing two-handed backhand strokes, leads to higher BMC and BMD in the non-dominant arm, the lumbar region, and hips, indicating potential benefit to maintain bone health and strength. Whether this result leads to reducing the risk of osteoporosis needs to be investigated in further research.

RNA-dependent dynamic histone acetylation regulates MCL1 alternative splicing.

Histone deacetylases (HDACs) and lysine acetyltransferases (KATs) catalyze dynamic histone acetylation at regulatory and coding regions of transcribed genes. Highly phosphorylated HDAC2 is recruited within corepressor complexes to regulatory regions, while the nonphosphorylated form is associated with the gene body. In this study, we characterized the nonphosphorylated HDAC2 complexes recruited to the transcribed gene body and explored the function of HDAC-complex-mediated dynamic histone acetylation. HDAC1 and 2 were coimmunoprecipitated with several splicing factors, including serine/arginine-rich splicing factor 1 (SRSF1) which has roles in alternative splicing. The co-chromatin immunoprecipitation of HDAC1/2 and SRSF1 to the gene body was RNA-dependent. Inhibition of HDAC activity and knockdown of HDAC1, HDAC2 or SRSF1 showed that these proteins were involved in alternative splicing of MCL1. HDAC1/2 and KAT2B were associated with nascent pre-mRNA in general and with MCL1 pre-mRNA specifically. Inhibition of HDAC activity increased the occupancy of KAT2B and acetylation of H3 and H4 of the H3K4 methylated alternative MCL1 exon 2 nucleosome. Thus, nonphosphorylated HDAC1/2 is recruited to pre-mRNA by splicing factors to act at the RNA level with KAT2B and other KATs to catalyze dynamic histone acetylation of the MCL1 alternative exon and alter the splicing of MCL1 pre-mRNA.

Utility of fluorescence in situ hybridization for ploidy and p57 immunostaining in discriminating hydatidiform moles.

Discrimination between complete moles (CMs), partial moles (PMs), and hydropic abortions (HAs) is important as the risk of persistent gestational trophoblastic disease (GTD) differs for each condition. We evaluated whether ancillary fluorescence in situ hybridization (FISH) with a set of chromosome enumeration probes (CEP) for chromosomes X, Y, and 17 and p57 immunostaining could improve the clinical diagnosis. Forty-one products of conception (POC) were reclassified according to clinical performance, morphology, p57 immunostaining results, and FISH results. The accuracy of histological examination alone was 85% for the original diagnosis. FISH analysis showed diploidy in 19 of 20 CMs and triploidy in 4 of 6 PMs. The concordance rate was 92.5% on using the CEP probes. p57 Staining was negative in all CMs and positive in all PMs and HAs. Chromosomal abnormality was detected in 3 cases of HA by using FISH. In conclusion, combined p57 immunostaining and FISH with a set of 3 CEP probes for chromosomes X, Y, and 17 could be useful in the classification of hydatidiform moles.

Immunosenescence of brain accelerates Alzheimer's disease progression.

Most of Alzheimer's disease (AD) cases are sporadic and occur after age 65. With prolonged life expectancy and general population aging, AD is becoming a significant public health concern. The immune system supports brain development, plasticity, and homeostasis, yet it is particularly vulnerable to aging-related changes. Aging of the immune system, called immunosenescence, is the multifaceted remodeling of the immune system during aging. Immunosenescence is a contributing factor to various age-related diseases, including AD. Age-related changes in brain immune cell phenotype and function, crosstalk between immune cells and neural cells, and neuroinflammation work together to promote neurodegeneration and age-related cognitive impairment. Although numerous studies have confirmed the correlation between systemic immune changes and AD, few studies focus on the immune state of brain microenvironment in aging and AD. This review mainly addresses the changes of brain immune microenvironment in aging and AD. Specifically, we delineate how various aspects of the brain immune microenvironment, including immune gateways, immune cells, and molecules, and the interplay between immune cells and neural cells, accelerate AD pathogenesis during aging. We also propose a theoretical framework of therapeutic strategies selectively targeting the different mechanisms to restore brain immune homeostasis.

Breath Acetone Sensing Based on Single-Walled Carbon Nanotube-Titanium Dioxide Hybrids Enabled by a Custom-Built Dehumidifier.

Acetone is a metabolic byproduct found in the exhaled breath and can be measured to monitor the metabolic degree of ketosis. In this state, the body uses free fatty acids as its main source of fuel because there is limited access to glucose. Monitoring ketosis is important for type I diabetes patients to prevent ketoacidosis, a potentially fatal condition, and individuals adjusting to a low-carbohydrate diet. Here, we demonstrate that a chemiresistor fabricated from oxidized single-walled carbon nanotubes functionalized with titanium dioxide (SWCNT@TiO2) can be used to detect acetone in dried breath samples. Initially, due to the high cross sensitivity of the acetone sensor to water vapor, the acetone sensor was unable to detect acetone in humid gas samples. To resolve this cross-sensitivity issue, a dehumidifier was designed and fabricated to dehydrate the breath samples. Sensor response to the acetone in dried breath samples from three volunteers was shown to be linearly correlated with the two other ketone bodies, acetoacetic acid in urine and ß-hydroxybutyric acid in the blood. The breath sampling and analysis methodology had a calculated acetone detection limit of 1.6 ppm and capable of detecting up to at least 100 ppm of acetone, which is the dynamic range of breath acetone for someone with ketosis. Finally, the application of the sensor as a breath acetone detector was studied by incorporating the sensor into a handheld prototype breathalyzer.

Phosphorylated serine 28 of histone H3 is associated with destabilized nucleosomes in transcribed chromatin.

Histone modifications and variants have key roles in the activation and silencing of genes. Phosphorylation of histone H3 at serine 10 and serine 28 is involved in transcriptional activation of genes responding to stress or mitogen-stimulated signaling pathways. The distribution of H3-modified isoforms in G0 phase chicken erythrocyte chromatin was investigated. H3 phosphorylated at serine 28 was found highly enriched in the active/competent gene fractions, as was H3 di- and trimethylated at lysine 4. The H3 variant H3.3 in this chromatin fraction was preferentially phosphorylated at serine 28. Conversely, H3 phosphorylated at serine 10 was present in all chromatin fractions, while H3 dimethylated at lysine 9 was associated with the chromatin-containing repressed genes. H3 phosphorylated at serine 28 was located at the promoter region of the transcriptionally active, but not competent, histone H5 and beta-globin genes. We provide evidence that H3.3 phosphorylated at serine 28 was present in labile nucleosomes. We propose that destabilized nucleosomes containing H3.3 phosphorylated at serine 28 aid in the dynamic disassembly-assembly of nucleosomes in active promoters.

Effects of caffeine and sex on muscle performance and delayed-onset muscle soreness after exercise-induced muscle damage: a double-blind randomized trial.

The present study aims to investigate effects of caffeine ingestion and sex difference on muscle performance, delayed-onset muscle soreness (DOMS), and various biomarkers under exercise-induced muscle damage (EIMD). Twenty (10 male and 10 female) healthy elite college athletes were recruited. Participants ingested either caffeine (6 mg/kg) or a placebo in a randomized, double-blind, and counterbalanced fashion at 24 and 48 h following EIMD. Muscle performance, DOMS, and blood samples were taken an hour before and an hour after supplementation. Caffeine ingestion restored impaired maximal voluntary isometric contractions (MVIC: 10.2%; MVICpost: 7.2%, both P < 0.05) during EIMD across both sexes. Following caffeine ingestion during MVIC, while affected by EIMD, an interaction was found in DOMS and serum K+ (both P < 0.05), with males showing greater attenuation (21.5 and 16.9%, respectively) compared with females (4.6 and 1.3%, respectively). DOMS demonstrated an inverse correlation with MVIC after caffeine ingestion both overall and among male athletes (r = -0.34 and -0.54, respectively; P < 0.05) but not among female athletes (r = -0.11; P > 0.05) under EIMD. In addition, caffeine ingestion increased postexercise serum glucose and lactate concentrations across both sexes (both P < 0.05). This is the first study to show that male athletes, compared with female athletes, experience a greater reduction in DOMS during enhanced MVIC when caffeine was consumed, suggesting men might receive greater ergogenic effects from caffeine when affected by EIMD. Furthermore, caffeine ingestion was able to restore impaired muscle power among elite collegiate athletes across both sexes.NEW & NOTEWORTHY Exercise-induced muscle damage (EIMD) reduces anaerobic/aerobic performance and increases delayed-onset muscle soreness (DOMS) during exercise. We show that acute caffeine supplementation at a dosage of 6 mg/kg seems to facilitate recovery of anaerobic muscle power and attenuate DOMS after EIMD across both sexes. Furthermore, male athletes, compared with female athletes, when caffeine was prescribed, experience a greater reduction in DOMS with better restoration of impaired maximal voluntary isometric contractions. This suggests that male athletes might benefit from the ergogenic effect of acute caffeine supplementation after the onset of EIMD.

Chromatin organization and nuclear microenvironments in cancer cells.

Nuclear morphometric descriptors such as nuclear size, shape, DNA content and chromatin organization are used by pathologists as diagnostic markers for cancer. However, our knowledge of events resulting in changes in nuclear shape and chromatin organization in cancer cells is limited. Nuclear matrix proteins, which include lamins, transcription factors (Sp1) and histone modifying enzymes (histone deacetylases), and histone modifications (histone H3 phosphorylation) have roles in organizing chromatin in the interphase nucleus, regulating gene expression programs and determining nuclear shape. Histone H3 phosphorylation, a downstream target of the Ras-mitogen activated protein kinase pathway, is involved in neoplastic transformation. This article will review genetic and epigenetic events that alter chromatin organization in cancer cells and the role of the nuclear matrix in determining nuclear morphology.

Comprehensive assessment of coastal eutrophication in Taiwan and its implications for management strategy.

Due to the rapid population growth, anthropogenic activities result in agricultural, industrial, and urban diffuse runoffs that elevate the level of nutrients such as nitrogen and phosphorus in coastal waters. Currently there is no integrated analysis for coastal eutrophication in Taiwan. A comprehensive analysis of the coastal eutrophic status was performed in this study based on decade-long coastal water quality monitoring data from Taiwan's Environmental Protection Administration. A 3-tiered monitoring strategy is recommended based on the severity of the current eutrophication state. Results indicate that the most problematic area of coastal eutrophication is located in the estuary of the Donggang River (DGR) and its adjacent coastal waters, i.e., the Kao-Ping mouth (KPM) and Dapeng Bay (DPB) in south-western Taiwan. With a worsening eutrophic status, these areas demand intensive monitoring and research with higher spatial and temporal resolutions to evaluate the stresses of nutrient forcing and predict possible future responses.

Differential distribution of unmodified and phosphorylated histone deacetylase 2 in chromatin.

Histone deacetylase 2 (HDAC2) is one of the histone-modifying enzymes that regulate gene expression by remodeling chromatin structure. Along with HDAC1, HDAC2 is found in the Sin3 and NuRD multiprotein complexes, which are recruited to promoters by DNA-binding proteins. In this study, we show that the majority of HDAC2 in human breast cancer cells is not phosphorylated. However, the minor population of HDAC2, preferentially cross-linked to DNA by cisplatin, is mono-, di-, or tri-phosphorylated. Furthermore, HDAC2 phosphorylation is required for formation of Sin3 and NuRD complexes and recruitment to promoters by transcription factors including p53, Rb, YY1, NF-kappaB, Sp1, and Sp3. Unmodified HDAC2 requires linker DNA to associate with chromatin but is not cross-linked to DNA by formaldehyde. We provide evidence that unmodified HDAC2 is associated with the coding region of transcribed genes, whereas phosphorylated HDAC2 is primarily recruited to promoters.

Isolation of transcriptionally active chromatin from human breast cancer cells using Sulfolink coupling gel chromatography.

The process of transcription unfolds the nucleosome. The unfolded nucleosome structure will be maintained as long as the histones are in a highly acetylated state. Typically the cysteine residue at position 110 of histone H3 is buried in the interior of the nucleosome. However, the transcribed unfolded nucleosome has its H3 cysteine exposed, offering a tag to isolate and study transcribed nucleosomes. In this study, we applied Sulfolink Coupling Gel chromatography to isolate unfolded nucleosomes from estrogen dependent human cancer T5 cells. Inhibition of histone deacetylase activity did not enhance the yield of unfolded nucleosomes from these cells. We show that the estrogen receptor and c-myc transcribed DNA sequences are associated with unfolded nucleosomes. In chromatin immunoprecipitation (ChIPs) assays, we found that the coding regions of the estrogen receptor and c-myc genes are bound to highly acetylated H3 and H4 in cultured T5 Cells. We conclude that in cultured T5 breast cancer cells H3 and H4 are in highly acetylated states maintaining the unfolded structure of the transcribed nucleosome and facilitating subsequent rounds of elongation.

Measurement of histone acetyltransferase and histone deacetylase activities and kinetics of histone acetylation.

Dynamic histone acetylation has a role in chromatin remodeling and in the regulation of transcription. Histone deacetylases (HDACs) and histone acetyltransferases (HATs) catalyze reversible histone acetylation. HATs and HDACs exist as multiprotein complexes that have coactivator and corepressor activities, respectively. The steady-state level of acetylation at a chromatin site is determined by the local net activities of these enzymes. Here we describe methods to isolate different subcellular fractions (cytosol, nuclei, tightly bound nuclear, loosely bound nuclear, immunoprecipitated multiprotein complexes, and nuclear matrix) to determine the subcellular distribution of HAT and HDAC activities. Procedures to assay the activities of these enzymes and to measure the kinetics of histone acetylation and deacetylation are presented.

The transcriptional repressor Sp3 is associated with CK2-phosphorylated histone deacetylase 2.

Sp1 and Sp3 are ubiquitously expressed mammalian transcription factors that function as activators or repressors. Although both transcription factors share a common domain involved in forming multimers, we demonstrate that Sp1 and Sp3 form separate complexes in estrogen-dependent human breast cancer cells. Sp1 and Sp3 complexes associate with histone deacetylases (HDACs) 1 and 2. Although most HDAC2 is not phosphorylated in the breast cancer cells, HDAC2 bound to Sp1 and Sp3 and cross-linked to chromatin in situ is highly enriched in a phosphorylated form that has a reduced mobility in SDS-polyacrylamide gels. We show that protein kinase CK2 is associated with and phosphorylates HDAC2. Alkaline phosphatase treatment of HDAC2 and Sp1 and Sp3 complexes reduced the associated HDAC activity. Protein kinase CK2 is up-regulated in several cancers including breast cancer, and Sp1 and Sp3 have key roles in estrogen-induced proliferation and gene expression in estrogen-dependent breast cancer cells. CK2 phosphorylation of HDAC2 recruited by Sp1 or Sp3 could regulate HDAC activity and alter the balance of histone deacetylase and histone acetyltransferase activities and dynamic chromatin remodeling of estrogen-regulated genes.