An Acylase from Shewanella Putrefaciens Presents a Vibrio Parahaemolyticus Acylhomoserine Lactone-Degrading Activity and Exhibits Temperature-, Ph- and Metal-Dependences

Shewanella putrefaciens supernatant was found to increase the virulence factors of Vibrio parahaemolyticus by efficiently degrading its acylhomoserine lactone (AHL). To further reveal the regulation mechanism and its key degrading enzyme, a potential AHL-degrading enzyme acylase (Aac) from S. putrefaciens was cloned, and the influences of temperature, pH, protein modifiers, and metals on Aac were tested. Aac was significantly influenced by temperature and pH, and exhibited the highest AHL-degrading activity at temperatures of 37 °C and pH of 8. Mg2+ and Fe2+ can further increase the AHL-degrading activity. 10 mM EDTA inhibited its activity possibly by chelating the co-factors (metals) required for Aac activity. Tryptophan and arginine were identified as key components for Aac activity that are critical to its AHL-degrading activity. This study provides useful information on Aac and for V. parahaemolyticus control.

Mindfulness-based stress reduction alters brain activity for breast cancer survivors with chronic neuropathic pain: preliminary evidence from resting-state fMRI

PURPOSE

Breast cancer continues to be the most commonly diagnosed cancer among Canadian women, with as many as 25-60% of women suffering from chronic neuropathic pain (CNP) as a pervasive consequence of treatment. While pharmacological interventions have shown limited efficacy for the management of CNP to date, psychological interventions, such as mindfulness-based stress reduction (MBSR), may be a promising alterative for improving pain-related problems. The purpose of this study was to use brain imaging methods to investigate this potential.

METHODS

Resting-state fMRI was used in female breast cancer survivors with CNP before and after an 8-week MBSR course (n = 13) and compared with a waitlist control group (n = 10).

RESULTS

Focusing on the default mode network, the most significant results show greater posterior cingulate connectivity with medial prefrontal regions post-MBSR intervention. Moreover, this change in connectivity correlated with reduced pain severity for the MBSR group.

CONCLUSIONS

These results provide empirical evidence of a change in the brain following MBSR intervention associated with changes in the subjective experience of pain.

IMPLICATIONS FOR CANCER SURVIVORS

This study gives hope for a non-invasive method of easing the struggle of CNP in women following breast cancer treatment.

Phononic Helical Nodal Lines with PT Protection in MoB_{2}

While condensed matter systems host both fermionic and bosonic quasiparticles, reliably predicting and empirically verifying topological states is only mature for Fermionic electronic structures, leaving topological Bosonic excitations sporadically explored. This is unfortunate, as Bosonic systems such as phonons offer the opportunity to assess spinless band structures where nodal lines can be realized without invoking special additional symetries to protect against spin-orbit coupling. Here we combine first-principles calculations and meV-resolution inelastic x-ray scattering to demonstrate the first realization of parity-time reversal symmetry protected helical nodal lines in the phonon spectrum of MoB_{2}. This structure is unique to phononic systems as the spin-orbit coupling present in electronic systems tends to lift the degeneracy away from high-symmetry locations. Our study establishes a protocol to accurately identify topological Bosonic excitations, opening a new route to explore exotic topological states in crystalline materials.

MiRNA-616 aggravates the progression of bladder cancer by regulating cell proliferation, migration and apoptosis through downregulating SOX7

OBJECTIVE

To investigate the regulatory effect of microRNA-616 (miRNA-616) on cellular behaviors of bladder cancer and the potential mechanism.

PATIENTS AND METHODS

The expressions of miRNA-616 and SOX7 in bladder cancer tissues and cell lines were examined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between miRNA-616 and SOX7 was assessed through Dual-Luciferase Reporter Gene Assay. The regulatory effects of miRNA-616 and SOX7 on cellular behaviors of bladder cancer were evaluated through cell counting kit-8 (CCK-8), colony formation, transwell migration assay, and flow cytometry.

RESULTS

MiRNA-616 was upregulated, whereas SOX7 was downregulated in bladder cancer tissues and cell lines. The silence of miRNA-616 attenuated the proliferative and migratory abilities, arrested cell cycle progression in the G2 phase, and stimulated apoptosis in UMUC3 and T24 cells. SOX7 was the target gene of miRNA-616, and its level was negatively regulated by miRNA-616. The knockdown of SOX7 enhanced the proliferative and migratory abilities, and attenuated apoptosis of bladder cancer cells.

CONCLUSIONS

MiRNA-616 accelerates bladder cancer cells to proliferate and migrate and inhibits apoptosis by downregulating SOX7. MiRNA-616/SOX7 may be potential therapeutic targets for bladder cancer.

Protective effect of resveratrol on kidney in rats with diabetic nephropathy and its effect on endoplasmic reticulum stress

OBJECTIVE

Diabetic nephropathy (DN) can cause chronic renal insufficiency and significantly reduce the life quality of patients with diabetes mellitus, and may eventually lead to death. The study investigated the expression of endoplasmic reticulum stress-related factors, which have important roles in the progress of DN and to explore effects of resveratrol on DN and the possible mechanism.

MATERIALS AND METHODS

Specific pathogen free (SPF) grade healthy male Sprague Dawley (SD) rats were divided into different groups for different treatments. The diabetic rat model was established by intraperitoneal injection of low-dose streptozotocin (STZ) (40 mg/kg). The normal rats and diabetes model rats were divided into four groups including normal control group (N), normal control + resveratrol (N+R), model group (M), and model + resveratrol group (M+R) for different treatments. The changes of renal histology were observed by immunohistochemistry. Glucose oxidase/peroxidase method was used to measure FPG, UP 24 h content was measured by bicinchoninic acid (BCA) assay, BUN, Scr and Cys C content were measured by automatic biochemical analyzer. The expressions of 78 kDa glucose-regulated protein (GRP78), protein kinase RNA-like endoplasmic reticulum kinase (PERK), and activating transcription factor 4 (ATF4) and C/EBP-homologous protein (CHOP) were analyzed by Western blot.

RESULTS

Resveratrol treatment significantly reduced the fasting blood glucose level, urinary protein level and renal pathological damage. The phosphorylation of PERK in the kidney of rats with diabetes was up-regulated, while resveratrol treatment reduced this change. The expression of p- PERK, GRP78, ATF4, and CHOP was significantly increased in rats with diabetes, while resveratrol treatment can reduce the increased level of those endoplasmic reticulum stress related factors.

CONCLUSIONS

Resveratrol has a good therapeutic effect on DN in rats without side effect. The mechanism may be related to the regulation of endoplasmic reticulum stress response.

B-09 Cerebral Grey Matter After Out-Of-Hospital Cardiac Arrest In Good Outcome Survivors

Objective

The purpose of this study was to evaluate the impact of out-of-hospital cardiac arrest (OHCA) on cognitive functioning and brain volumes, in good outcome survivors.

Method

Participants were medically stable OHCA survivors. Two control groups were also recruited: patients who experienced myocardial infarction (MI), and healthy controls (HC) with no history of cardiovascular disease. Neuropsychological assessment was conducted using the Neuropsychological Assessment Battery (NAB). Imaging was performed on a 3T Siemens Trio MRI scanner. Cerebral grey matter volume (GM; measured by voxel-based morphometry in SPM12) results are presented.

Results

Participants (nOHCA = 9, nMI = 19, nHC = 13) ranged in age from 30 to 85 years. When controlling for age, whole-brain analyses revealed decreased GM in anterior cingulate cortex, bilateral hippocampus in the OHCA and in the MI group compared to the HC group. In addition, the MI group had decreased GM compared to the HC in the thalamus and the right dorsolateral prefrontal cortex (p < .001). No significant differences in GM were observed between the MI and OHCA groups. The hippocampus was selected as a region-of-interest for further analyses. The Total NAB Index was correlated with hippocampal GM in the OHCA group but not in the MI group (rOHCA = .78, p = .014).

Conclusions

Results revealed select areas of GM reduction in OHCA and MI groups, suggesting a contribution of cardiovascular disease to observed atrophy. Reductions are related to cognitive performance only in the cardiac arrest group which may suggest that these volume losses represent clinically meaningful changes.

Magnetic-Competition-Induced Colossal Magnetoresistance in n-Type HgCr_{2}Se_{4} under High Pressure

The n-type HgCr_{2}Se_{4} exhibits a sharp semiconductor-to-metal transition (SMT) in resistivity accompanying the ferromagnetic order at T_{C}=106  K. Here, we investigate the effects of pressure and magnetic field on the concomitant SMT and ferromagnetic order by measuring resistivity, dc and ac magnetic susceptibility, as well as single-crystal neutron diffraction under various pressures up to 8 GPa and magnetic fields up to 8 T. Our results demonstrate that the ferromagnetic metallic ground state of n-type HgCr_{2}Se_{4} is destabilized and gradually replaced by an antiferromagnetic, most likely a spiral magnetic, and insulating ground state upon the application of high pressure. On the other hand, the application of external magnetic fields can restore the ferromagnetic metallic state again at high pressures, resulting in a colossal magnetoresistance (CMR) as high as ∼ 3×10^{11}% under 5 T and 2 K at 4 GPa. The present study demonstrates that n-type HgCr_{2}Se_{4} is located at a peculiar critical point where the balance of competition between ferromagnetic and antiferromagnetic interactions can be easily tipped by external stimuli, providing a new platform for achieving CMR in a single-valent system.

Observation of Double Weyl Phonons in Parity-Breaking FeSi

Condensed matter systems have now become a fertile ground to discover emerging topological quasiparticles with symmetry protected modes. While many studies have focused on fermionic excitations, the same conceptual framework can also be applied to bosons yielding new types of topological states. Motivated by Zhang et al.'s recent theoretical prediction of double Weyl phonons in transition metal monosilicides [Phys. Rev. Lett. 120, 016401 (2018)PRLTAO0031-900710.1103/PhysRevLett.120.016401], we directly measure the phonon dispersion in parity-breaking FeSi using inelastic x-ray scattering. By comparing the experimental data with theoretical calculations, we make the first observation of double Weyl points in FeSi, which will be an ideal material to explore emerging bosonic excitations and its topologically nontrivial properties.

Visual preconditioning reduces emergence delirium in children undergoing ophthalmic surgery: a randomised controlled trial

BACKGROUND

Emergence delirium is a common complication in children, especially in preschool children undergoing ophthalmic surgery. The aim of the study was to investigate the effects of visual preconditioning (application of an eyepatch over the eye to be operated for ≥3 h the day before surgery) on emergence delirium after ophthalmic surgery under sevoflurane anaesthesia.

METHODS

One hundred and seventy-nine children undergoing unilateral cataract surgery, aged 3-7 yr, were involved in this prospective, blinded, randomised study. Subjects were randomised to receive visual preconditioning (Group P, n=89) or to receive programmed explanation the day before surgery (Group C, n=90). The primary outcome was incidence of emergence delirium evaluated by the paediatric anaesthesia emergence delirium (PAED) scale. The secondary outcomes included emergence time and post-anaesthesia care unit (PACU) stay time.

RESULTS

Children in Group P had a significantly lower incidence of emergence delirium than those in Group C [16.9% vs 44.4%, odds ratio (OR) 4.0, 95% confidence interval (CI) 2.0 to 8.0]. The maximal PAED score was lower in Group P than in Group C [4 (0-20) vs 9 (0-20), median difference -3.0, 95% CI -5.0 to -1.0]. Visual preconditioning prolonged emergence time (P<0.001) and PACU stay time (P=0.002).

CONCLUSION

Visual disturbance contributes to emergence delirium in preschool children undergoing ophthalmic surgery with sevoflurane, and prophylactic eyepatch treatment can reduce emergence delirium.

CLINICAL TRIALS REGISTRATION

NCT02590744.