DNAH17 is associated with asthenozoospermia and multiple morphological abnormalities of sperm flagella.

BACKGROUND(#br)Multiple morphological abnormalities of the sperm flagella (MMAF) is one kind of severe asthenozoospermia, which is caused by dysplastic development of sperm flagella. In our study, we sought to investigate the novel gene mutations leading to severe asthenozoospermia and MMAF.(#br)METHODS AND MATERIALS(#br)The patient’s spermatozoa were tested by Papanicolaou staining and transmission electron microscopy. Whole exome sequencing was performed on the patient with severe asthenozoospermia and MMAF. Sanger sequencing verified the mutations in the family. The expression of DNAH17 was detected by immunofluorescence and Western blot.(#br)RESULTS(#br)Spermatozoa sample from the patient showed severe asthenozoospermia and MMAF. We detected biallelic mutations (c.C4445T, p.A1482V and c.C6857T, and p.S2286L) in DNAH17 (MIM:610063). The protein expression of DNAH17 was almost undetectable in spermatozoa from the patient with the biallelic mutations.(#br)CONCLUSION(#br)These results demonstrated that DNAH17 may be involved in severe asthenozoospermia and MMAF

Neurochemical changes in patients with chronic low back pain detected by proton magnetic resonance spectroscopy: A systematic review

Background: Low back pain is a highly prevalent health problem around the world, affecting 50% to 85% of people at some point in life. The purpose of this systematic review is to summarize the previous proton magnetic resonance spectroscopy studies on brain chemical changes in patients with chronic low back pain (CLBP). Methods: We identified relevant studies from a literature search of PubMed and EMBASE from 1980 to March 2016. Data extraction was performed on the subjects' characteristics, MRS methods, spectral analyses, cerebral metabolites and perceptual measurements. Results: The review identified 9 studies that met the inclusion criteria, comprised of data on 135 CLBP subjects and 137 healthy controls. Seven of these studies reported statistically different neurochemical alterations in patients with CLBP. The results showed that compared to controls, CLBP patients showed reductions of 1) N-acetyl-aspartate (NAA) in the dorsolateral prefrontal cortex (DLPFC), right primary motor cortex, left somatosensory cortex (SSC), left anterior insula and anterior cingulate cortex (ACC); 2) glutamate in the ACC; 3) myo-inositol in the ACC and thalamus; 4) choline in the right SSC; and 5) glucose in the DLPFC. Conclusion: This review provides evidence for alterations in the biochemical profile of the brain in patients with CLBP, which suggests that biochemical changes may play a significant role in the development and pathophysiology of CLBP and shed light on the development of new treatments for CLBP

Strength behaviors of CH₄ hydrate-bearing silty sediments during thermal decomposition

Predicting the mechanical response of methane hydrate-bearing sediments prior to and during gas production enable appropriate design and anticipate risk due to extraction process of methane from deep-ocean and permafrost setting. In this study, a series of triaxial drained shear tests followed by hydrate dissociation were performed on artificial hydrate-bearing silty sediments at given porosity and stress conditions. The peak strength of HBSS increases exponentially with hydrate saturation, which signifies proportional loss of strength due to hydrate dissociation by thermal decomposition. The peak strength of partially dissociated sediments is slightly lower than the strength of sediments with similar hydrate saturation freshly formed. The enhancement effect of CH4 hydrate on the strength behaviors of HBSS would be more obvious under higher effective confining pressures. The peak strength increase of HBSS was not only due to the increase in cohesion component but also frictional component for a given hydrate saturation and porosity. Thermal decomposition of HBSS is governed directly by its hydrate saturation rather than the confining stress, although with higher confining stress the dissipation of the released gas is affected by the permeability of the sediments thus slightly prolonging the dissociation process.</p