Effects of breathing maneuver and sitting posture on muscle activity in inspiratory accessory muscles in patients with chronic obstructive pulmonary disease

BACKGROUND: To determine the influence of breathing maneuver and sitting posture on tidal volume (TV), respiratory rate (RR), and muscle activity of the inspiratory accessory muscles in patients with chronic obstructive pulmonary disease (COPD). METHODS: Twelve men with COPD participated in the study. Inductive respiratory plethysmography and surface electromyography were used to simultaneously measure TV, RR, and muscle activity of the inspiratory accessory muscles [the scalenus (SM), sternocleidomastoid (SCM), and pectoralis major (PM) muscles] during quiet natural breathing (QB) and pursed-lips breathing (PLB) in three sitting postures: neutral position (NP), with armm support (WAS), and with arm and head support (WAHS). RESULTS: Two-way repeated-measures analysis of variance was employed. In a comparison of breathing patterns, PLB significantly increased TV and decreased RR compared to QB. Muscle activity in the SM and SCM increased significantly in PLB compared to QB. In a comparison of sitting postures, the muscle activity of the SM, SCM, and PM increased in the forward-leaning position. CONCLUSIONS: The results suggest that in COPD, PLB induced a favorable breathing pattern (increased TV and reduced RR) compared to QB. Additionally, WAS and WAHS positions increased muscle activity of the inspiratory accessory muscles during inspiration versus NP. Differential involvement of accessory respiratory muscles can be readily studied in COPD patients, allowing monitoring of respiratory load during pulmonary rehabilitation

Evolution of MicroRNAs and the Diversification of Species

MicroRNAs (miRNAs) are ancient, short noncoding RNA molecules that regulate the transcriptome through post-transcriptional mechanisms. miRNA riboregulation is involved in a diverse range of biological processes, and misregulation is implicated in disease. It is generally thought that miRNAs function to canalize cellular outputs, for instance as “fail-safe” repressors of gene misexpression. Genomic surveys in humans have revealed reduced genetic polymorphism and the signature of negative selection for both miRNAs themselves and the target sequences to which they are predicted to bind. We investigated the evolution of miRNAs and their binding sites across cichlid fishes from Lake Malawi (East Africa), where hundreds of diverse species have evolved in the last million years. Using low-coverage genome sequence data, we identified 100 cichlid miRNA genes with mature regions that are highly conserved in other animal species. We computationally predicted target sites on the 3′-untranslated regions (3′-UTRs) of cichlid genes to which miRNAs may bind and found that these sites possessed elevated single nucleotide polymorphism (SNP) densities. Furthermore, polymorphic sites in predicted miRNA targets showed higher minor allele frequencies on average and greater genetic differentiation between Malawi lineages when compared with a neutral expectation and nontarget 3′-UTR SNPs. Our data suggest that divergent selection on miRNA riboregulation may have contributed to the diversification of cichlid species and may similarly play a role in rapid phenotypic evolution of other natural systems

Biological Aging Modulates Cell Migration via Lamin A/C-Dependent Nuclear Motion

Aging is a progressive functional decline in organs and tissues over time and typically represents the accumulation of psychological and social changes in a human being. Diverse diseases, such as cardiovascular, musculoskeletal, and neurodegenerative disorders, are now understood to be caused by aging. While biological assessment of aging mainly focuses on the gradual changes that occur either on the molecular scale, for example, alteration of gene expression and epigenetic modification, or on larger scales, for example, changes in muscle strength and cardiac function, the mechanics that regulates the behavior of individual cells and interactions between the internal elements of cells, are largely missing. In this study, we show that the dynamic features of migrating cells across different human ages could help to establish the underlying mechanism of biological age-dependent cellular functional decline. To determine the relationship between cellular dynamics and human age, we identify the characteristic relationship between cell migration and nuclear motion which is tightly regulated by nucleus-bound cytoskeletal organization. This analysis demonstrates that actomyosin contractility-dependent nuclear motion plays a key role in cell migration. We anticipate this study to provide noble biophysical insights on biological aging in order to precisely diagnose age-related chronic diseases

Calcite Nanocrystals Investigated Using X-ray Absorption Spectroscopy

For the present work, calcite nanocrystals were grown by annealing precursors at 500 °C. These precursors were obtained by three different thermal schemes. Among these schemes, two involve heating at 100 °C for 16 h and 16 + 24 h, respectively. In the third scheme, heating was performed at 100 °C for 16 h, followed by annealing at 300 °C for 24 h. X-ray diffraction studies, followed by Fourier transform infrared and Raman spectroscopic studies, exhibited the formation of calcite phase of calcium carbonate. Transmission electron microscopy showed that particle sizes of synthesized calcite nanocrystals were in the range of 25–40 nm. Onsets of shape change were also observed with different thermal schemes, using these measurements. X-ray absorption spectroscopy envisaged that the coordination numbers of Ca-O and Ca-Ca shell were not influenced by the thermal schemes; however, bond lengths of these shells were modified. This study in the near edge region evidenced the manifestation of a local electronic structure of calcite when kept in an open environment, depending upon different thermal schemes

Identification of a Systemic Lupus Erythematosus Risk Locus Spanning ATG16L2, FCHSD2, and P2RY2 in Koreans

OBJECTIVE: Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder whose etiology is incompletely understood, but likely involves environmental triggers in genetically susceptible individuals. We sought to identify the genetic loci associated with SLE in a Korean population by performing an unbiased genome-wide association scan. METHODS: A total of 1,174 Korean SLE cases and 4,248 population controls were genotyped with strict quality control measures and analyzed for association. For select variants, replication was tested in an independent set of 1,412 SLE cases and 1,163 population controls of Korean and Chinese ancestries. RESULTS: Eleven regions outside the HLA exceeded genome-wide significance (P<5×10(−8)). A novel SNP-SLE association was identified between FCHSD2 and P2RY2 peaking at rs11235667 (P = 1.0×10(−8), odds ratio (OR) = 0.59) on a 33kb haplotype upstream to ATG16L2. Replication for rs11235667 resulted in P(meta-rep)=0.001 and P(meta-overall)=6.67×10(−11) (OR=0.63). Within the HLA region, association peaked in the Class II region at rs116727542 with multiple independent effects. Classical HLA allele imputation identified HLA-DRB1*1501 and HLA-DQB1*0602, both highly correlated, as most strongly associated with SLE. We replicated ten previously established SLE risk loci: STAT1-STAT4, TNFSF4, TNFAIP3, IKZF1, HIP1, IRF5, BLK, WDFY4, ETS1 and IRAK1-MECP2. Of these loci, we identified previously unreported independent second effects in TNFAIP3 and TNFSF4 as well as differences in the association for a putative causal variant in the WDFY4 region. CONCLUSIONS: Further studies are needed to identify true SLE risk effects in other suggestive loci and to identify the causal variant(s) in the regions of ATG16L2, FCHSD2, and P2RY2