Tension-dependent RHGF-1 recruitment to stress fibers drives robust spermathecal tissue contraction.

Contractile epithelial tubes are found in various organs, such as lung airways and blood capillaries. Their ability to sense luminal pressure and respond with adequate contractility is essential for their physiology, and its mis-regulation results in diseases such as asthma and hypertension. Here, we describe a mechanoresponsive regulatory pathway downstream of tissue stretching that controls contraction of the C. elegans spermatheca, a tubular structure where fertilization occurs. Using live-imaging, we show that ovulation-induced stretching of spermathecal cells leads to recruitment of the RhoGEF RHGF-1 to stress fibers, which activates RHO-1 and myosin II in a positive feedback loop. Through deletion analysis, we identified the PDZ domain of RHGF-1 as responsible for F-actin binding, and genetic epistasis analysis with the RhoGAP spv-1 demonstrated that tension-dependent recruitment of RHGF-1 to F-actin is required for robust spermathecal contractility. Our study illustrates how mechanosensitive regulators of Rho GTPases provide epithelial tubes the ability to tune their contractility in response to internal pressure.

miR-515-5p inhibits the proliferation, migration and invasion of human breast cancer cells by targeting CBX4.

microRNA (miR)-515-5p has been previously suggested to function as a tumor suppressor in various types of human cancer. Therefore, the role of miR-515-5p in breast cancer (BC) was explored in the present study. A series of assays were performed to study the function of miR-515-p in BC cells, including Cell Counting Kit-8, TUNEL, flow cytometric and colony formation to detect cell viability and apoptosis, wound healing and Transwell assays to measure cell motility. In addition, reverse transcription quantitative PCR and western blot analysis were used to assess miR-515-5p, CBX4, Cox-2, MMP2, MMP9, CDK2, p21 and Cyclin D1 respectively. Bioinformatics and dual-luciferase reporter assays were used to analyze the target genes of miR-515-5p, which confirmed the direct binding between miR-515-5p and polycomb chromobox 4 (CBX4). It was found that the expression of miR-515-5p is lower in BC cells compared with that in normal breast cells (MCF10A). Overexpression of miR-515-5p using the miR-515 mimic was found to reduce cell viability, facilitate cell apoptosis, inhibit cell proliferation and arrest cell cycle progressio at G1 phase. In addition, miR-515-5p overexpression could inhibit cell migration and invasion, whilst decreasing the expression levels of prostaglandin-endoperoxide synthase 2, MMP2 and MMP9 proteins. In addition, miR-515-5p overexpression could reduce the expression levels of CBX4 in MCF7 and ZR-75-30 cells. By contrast, overexpression of CBX4 reversed the effects of the miR-515-5p mimic transfection on cell proliferation, migration and invasion in MCF7 and ZR-75-30 cells. In combination, these results suggest that miR-515-5p inhibits BC cell proliferation, migration and invasion by directly targeting CBX4.

Time to intubation with McGrath™ videolaryngoscope versus direct laryngoscope in powered air-purifying respirator: a randomised controlled trial.

INTRODUCTION: During the COVID-19 pandemic, multiple guidelines have recommended the videolaryngoscope for tracheal intubation. However, there is no evidence that videolaryngoscope reduces time to tracheal intubation, which is important for COVID-19 patients with respiratory failure. METHODS: To simulate intubation of COVID-19 patients, we randomised 28 elective surgical patients to be intubated with either the McGrath™ MAC videolaryngoscope or the direct laryngoscope by specialist anaesthetists donning 3M™ Jupiter™ powered air-purifying respirators (PAPR) and N95 masks. Primary outcome was time to intubation. RESULTS: The median (IQR) times to intubation were 61s (37-63 s) and 41.5s (37-56 s) in the videolaryngoscope and direct laryngoscope groups respectively (p = 0.35). The closest mean (SD) distances between the anaesthetist and the patient during intubation were 21.6 cm (4.8 cm) and 17.6 cm (5.3 cm) in the videolaryngoscope and direct laryngoscope groups, respectively (p = 0.045). There were no significant differences in the median intubation difficulty scale scores, proportion of successful intubation at first laryngoscopic attempt and proportion of intubations requiring adjuncts. Intubations for all the patients were successful with no adverse event. CONCLUSION: There was no significant difference in the time to intubation by specialist anaesthetists who were donned in PAPR and N95 masks on elective surgical patients with either the McGrath™ videolaryngoscope or direct laryngoscope. The distance between the anaesthetist and patient was significantly further with the videolaryngoscope. The direct laryngoscope could be an equal alternative to videolaryngoscope for specialist anaesthetists when resources are limited or disrupted due to the pandemic.

Postoperative delirium following total joint arthroplasties in a multi-ethnic population - A prospective observational study.

BACKGROUND: Postoperative delirium (POD) is a cause of poorer patient outcomes following total joint arthroplasties (TJA). However, it often goes undiagnosed. Although various risk factors have been documented, study heterogeneity leads to poor understanding within a South East Asian population. This study aims to evaluate POD within this demographic and elucidate its risk factors. METHODS: This was a single-centre prospective observational study comprising 462 patients. Inclusion criteria was patients 65-90 years old undergoing elective TJA. Exclusion criteria was patients unable to personally provide consent for TJA. Preoperative, intraoperative, and postoperative data was recorded to analyse treatment pathway factors. Patients were assessed for POD twice daily for 3 days after TJA using the Confusion Assessment Method (CAM). RESULTS: Mean age of the study cohort was 72 ± 5 years; 70.1% were female; and mean MMSE score preoperatively was 27.3 ± 3.3. 419 patients underwent total knee arthroplasty (TKA) and 43 patients underwent total hip arthroplasty (THA). 164 patients received general anaesthesia, and 298 patients received regional anaesthesia. Overall, 0% (0/462) of patients tested positive for POD at any postoperative timepoint. While various CAM components were met, no patients were positive for the complete requisite criteria for POD diagnosis. CONCLUSION: We report zero incidence of POD in 462 patients who underwent elective TJA in our institution. We believe that our streamlined care process including pre-operative assessment, patient-specific anaesthesia regime as well as a strictly administered inpatient clinical care pathway with opioid-reducing strategy and early mobilization are protective factors against POD.

MiR-548c-3p inhibits the proliferation, migration and invasion of human breast cancer cell by targeting E2F3.

MiR-548 has been reported to be involved in a variety of tumor processes, but its function in breast cancer remains unclear. In this study, we found that miR-548 was low expressed in breast cancer tissues and cells compared with normal control. We then examined whether up-regulation of miR-548 could improve the progression of breast cancer. Our results indicate that up-regulation of miR-548 significantly inhibits cell proliferation, migration andinvasion, and induces apoptosis in breast cancer cells. Further studies showed that miR-548 could specifically inhibit E2F3 expression. Moreover, rescue test showed that up-regulation of E2F2 could reverse the effect of miR-548 on proliferation, migration, invasion and apoptosis of breast cancer cells. In general, miR-548 could improve the progression of breast cancer. By targeting E2F2, which may make a potential target for the treatment of breast cancer.

The AP-2 Transcription Factor APTF-2 Is Required for Neuroblast and Epidermal Morphogenesis in Caenorhabditis elegans Embryogenesis.

The evolutionarily conserved family of AP-2 transcription factors (TF) regulates proliferation, differentiation, and apoptosis. Mutations in human AP-2 TF have been linked with bronchio-occular-facial syndrome and Char Syndrome, congenital birth defects characterized by craniofacial deformities and patent ductus arteriosus, respectively. How mutations in AP-2 TF cause the disease phenotypes is not well understood. Here, we characterize the aptf-2(qm27) allele in Caenorhabditis elegans, which carries a point mutation in the conserved DNA binding region of AP-2 TF. We show that compromised APTF-2 activity leads to defects in dorsal intercalation, aberrant ventral enclosure and elongation defects, ultimately culminating in the formation of morphologically deformed larvae or complete arrest during epidermal morphogenesis. Using cell lineaging, we demonstrate that APTF-2 regulates the timing of cell division, primarily in ABarp, D and C cell lineages to control the number of neuroblasts, muscle and epidermal cells. Live imaging revealed nuclear enrichment of APTF-2 in lineages affected by the qm27 mutation preceding the relevant morphogenetic events. Finally, we found that another AP-2 TF, APTF-4, is also essential for epidermal morphogenesis, in a similar yet independent manner. Thus, our study provides novel insight on the cellular-level functions of an AP-2 transcription factor in development.

Living With Cancer Alone? The Experiences of Singles Diagnosed With Colorectal Cancer.

This paper seeks to understand the experiences of single colorectal cancer patients. This study consisted of 12 semi-structured interviews that were digitally voice-recorded, transcribed, and analyzed. Six main themes emerged: (a) gradual shift in view of cancer diagnosis from fatalistic to normalized, (b) perception of cancer as a nadir experience, (c) concerns of singlehood, (d) factors influencing cancer experiences, (e) factors influencing coping with cancer, and (f) range of responses towards cancer diagnosis. Singles with colorectal cancer require short- to long-term individualized care plans, and psycho-emotional support. This may help enhance their individual coping and adjustment to the diagnosis.

Transient membrane localization of SPV-1 drives cyclical actomyosin contractions in the C. elegans spermatheca.

BACKGROUND: Actomyosin contractility is the major cellular force driving changes in cell and tissue shape. A principal regulator of contractility is the small GTPase RhoA. External mechanical forces have been shown to impact RhoA activity and cellular contractility. However, the mechanotransduction pathway from external forces to actomyosin contractility is poorly understood. RESULTS: Here, we show that actomyosin contractility in the C. elegans spermatheca is under control of RHO-1/RhoA, which, in turn, is regulated by the F-BAR and RhoGAP protein SPV-1. In the relaxed spermatheca, SPV-1 localizes through its F-BAR domain to the apical membrane, where it inhibits RHO-1/RhoA activity through its RhoGAP domain. Oocyte entry forces the spermatheca cells to stretch, and subsequently SPV-1 detaches from the membrane, permitting RHO-1 activity to increase. The increase in RHO-1 activity facilitates spermatheca contraction and expulsion of the newly fertilized embryo into the uterus, leading to relaxation of the spermatheca, SPV-1 membrane localization, and initiation of a new cycle. CONCLUSIONS: Our results demonstrate how transient membrane localization of a novel F-BAR domain, likely via specific binding to curved membranes, coupled to a RhoGAP domain, can provide feedback between a mechanical signal (membrane stretching) and actomyosin contractility. We anticipate this to be a widely utilized feedback mechanism used to balance actomyosin forces in the face of externally applied forces, as well as intrinsic processes involving cell deformation, from single-cell migration to tissue morphogenesis.

A computational and experimental study of the regulatory mechanisms of the complement system.

The complement system is key to innate immunity and its activation is necessary for the clearance of bacteria and apoptotic cells. However, insufficient or excessive complement activation will lead to immune-related diseases. It is so far unknown how the complement activity is up- or down- regulated and what the associated pathophysiological mechanisms are. To quantitatively understand the modulatory mechanisms of the complement system, we built a computational model involving the enhancement and suppression mechanisms that regulate complement activity. Our model consists of a large system of Ordinary Differential Equations (ODEs) accompanied by a dynamic Bayesian network as a probabilistic approximation of the ODE dynamics. Applying Bayesian inference techniques, this approximation was used to perform parameter estimation and sensitivity analysis. Our combined computational and experimental study showed that the antimicrobial response is sensitive to changes in pH and calcium levels, which determines the strength of the crosstalk between CRP and L-ficolin. Our study also revealed differential regulatory effects of C4BP. While C4BP delays but does not decrease the classical complement activation, it attenuates but does not significantly delay the lectin pathway activation. We also found that the major inhibitory role of C4BP is to facilitate the decay of C3 convertase. In summary, the present work elucidates the regulatory mechanisms of the complement system and demonstrates how the bio-pathway machinery maintains the balance between activation and inhibition. The insights we have gained could contribute to the development of therapies targeting the complement system.

Generalizable mass spectrometry mining used to identify disease state biomarkers from blood serum.

We bring a "spectrum" of classical data mining and statistical analysis methods to bear on discrimination of two groups of spectra from 24 diseased and 17 normal patients. Our primary goal is to accurately estimate the generalizability of this small dataset. After an aggressive preprocessing step that reduces consideration to only 55 peaks, we conduct over 35 out-of-sample cross-validation simulations of logistic regression, binary decision trees, and linear discriminant analysis. Misclassification rates grow worse as the size of the holdout sample increases, with many exceeding 30 percent. The ability to generalize is clearly tempered by the statistical, instrumentation, and biophysical characteristics of the study.

[Evolution of fibrinolysis status with D-dimer level and the rate of plasminogen activator inhibitor type-1/D-dimer in acute coronary syndrome patients complicated with impaired glucose tolerance].

OBJECTIVE: To study the status of fibrinolytic inhibition in patients with acute coronary syndrome (ACS) complicated with impaired glucose tolerance (IGT) and to evaluate the effect of fibrinolytic inhibition on treatment and prognosis. METHODS: The subjects were divided into three groups included 39 patients with ACS without diabetes mellitus, 37 patients with IGT+ACS and 36 patients with ACS+noninsulin-dependent diabetes mellitus (NIDDM). Twenty healthy people were randomized to be control group. The plasma levels of tissue type plasminogen activator (t-PA), plasminogen activator inhibitor type-1 (PAI-1) and plasma D-dimer were detected by enzyme linked immunoadsorbent assay (ELISA) technique. The index of status of fibrinolysis was detected with the plasma levels of PAI-1, D-dimer and the ratio of PAI-1/D-dimer. This index was used to evaluate the status of fibrinolytic inhibition and the clinical out come in patients with AMI. RESULTS: Plasma level of PAI-1 was significantly higher in IGT+ACS patients and NIDDM +ACS patients than that in ACS(P<0.05), but the plasma level of D-dimer raised from basic level was significantly lower in IGT+ ACS patients and NIDDM+ACS patients than that in ACS (P<0.05). The ratio of PAI-1/D-dimer was significantly higher in IGT+ACS patients and NIDDM +ACS patients than that in ACS or in control group (P<0.01). For AMI patients in treatment groups, the rate of reperfusion after the thrombolytic was significantly lower and the rate of incidences in pump failure was significantly higher in IGT+ACS patients and NIDDM+ACS patients than that in ACS, too (P<0.01 and P<0.05). The incidences of serious arrhythmia, re-infarction and death were also higher in IGT+ACS patients and NIDDM +ACS patients. CONCLUSION: The fibrinolytic inhibition is existed in IGT+ACS group patients. The plasma level of D-dimer combined with the ratio of PAI-1/D-dimer could be used to be the evidence and to be the index to evaluate the status of fibrinolytic inhibition and prognosis.