39 research outputs found
Effect of an exercise training intervention with resistance bands on blood cell counts during chemotherapy for lung cancer: a pilot randomized controlled trial
PURPOSE: Chemotherapy for lung cancer can have a detrimental effect on white blood cell (WBC) and red blood cell (RBC) counts. Physical exercise may have a role in improving WBCs and RBCs, although few studies have examined cancer patients receiving adjuvant therapies. The purpose of this pilot trial was to examine the effects of an exercise intervention utilizing resistance bands on WBCs and RBCs in lung cancer patients receiving curative intent chemotherapy. METHODS: A sample of lung cancer patients scheduled for curative intent chemotherapy was randomly assigned to the exercise intervention (EX) condition or usual care (UC) condition. The EX condition participated in a three times weekly exercise program using resistance bands for the duration of chemotherapy. RESULTS: A total of 14 lung cancer patients completed the trial. EX condition participants completed 79% of planned exercise sessions. The EX condition was able to maintain WBCs over the course of the intervention compared to declines in the UC condition (p = .008; d = 1.68). There were no significant differences in change scores in RBCs. CONCLUSIONS: Exercise with resistance bands may help attenuate declines in WBCs in lung cancer patients receiving curative intent chemotherapy. Larger trials are warranted to validate these findings. Ultimately these findings could be informative for the development of supportive care strategies for lung cancer patients receiving chemotherapy. TRIAL REGISTRATION: Clinical Trials Registration #: NCT01130714
Transthyretin Aggregation Pathway toward the Formation of Distinct Cytotoxic Oligomers
Characterization of small oligomers formed at an early stage of amyloid formation is critical to
understanding molecular mechanism of pathogenic aggregation process. Here we identifed and
characterized cytotoxic oligomeric intermediates populated during transthyretin (TTR) aggregation
process. Under the amyloid-forming conditions, TTR initially forms a dimer through interactions
between outer strands. The dimers are then associated to form a hexamer with a spherical shape, which
serves as a building block to self-assemble into cytotoxic oligomers. Notably, wild-type (WT) TTR tends
to form linear oligomers, while aTTR variant(G53A) prefers forming annular oligomers with pore-like
structures. Structural analyses of the amyloidogenic intermediates using circular dichroism (CD) and
solid-state NMR revealthatthe dimer and oligomers have a signifcant degree of native-like β-sheet
structures (35–38%), but with more disordered regions (~60%)than those of nativeTTR.TheTTR variant
oligomers are also less structured than WT oligomers. The partially folded nature of the oligomeric
intermediates might be a common structural property of cytotoxic oligomers.The higher fexibility of
the dimer and oligomers may also compensate for the entropic loss due to the oligomerization of the
monomers
Positive Evolutionary Selection of an HD Motif on Alzheimer Precursor Protein Orthologues Suggests a Functional Role
HD amino acid duplex has been found in the active center of many different enzymes. The dyad plays remarkably different roles in their catalytic processes that usually involve metal coordination. An HD motif is positioned directly on the amyloid beta fragment (Aβ) and on the carboxy-terminal region of the extracellular domain (CAED) of the human amyloid precursor protein (APP) and a taxonomically well defined group of APP orthologues (APPOs). In human Aβ HD is part of a presumed, RGD-like integrin-binding motif RHD; however, neither RHD nor RXD demonstrates reasonable conservation in APPOs. The sequences of CAEDs and the position of the HD are not particularly conserved either, yet we show with a novel statistical method using evolutionary modeling that the presence of HD on CAEDs cannot be the result of neutral evolutionary forces (p<0.0001). The motif is positively selected along the evolutionary process in the majority of APPOs, despite the fact that HD motif is underrepresented in the proteomes of all species of the animal kingdom. Position migration can be explained by high probability occurrence of multiple copies of HD on intermediate sequences, from which only one is kept by selective evolutionary forces, in a similar way as in the case of the “transcription binding site turnover.” CAED of all APP orthologues and homologues are predicted to bind metal ions including Amyloid-like protein 1 (APLP1) and Amyloid-like protein 2 (APLP2). Our results suggest that HDs on the CAEDs are most probably key components of metal-binding domains, which facilitate and/or regulate inter- or intra-molecular interactions in a metal ion-dependent or metal ion concentration-dependent manner. The involvement of naturally occurring mutations of HD (Tottori (D7N) and English (H6R) mutations) in early onset Alzheimer's disease gives additional support to our finding that HD has an evolutionary preserved function on APPOs