Monitoring and modelling the dynamics of the cellular glycolysis pathway: A review and future perspectives

Background The dynamics of the cellular glycolysis pathway underpin cellular function and dysfunction, and therefore ultimately health, disease, diagnostic and therapeutic strategies. Evolving our understanding of this fundamental process and its dynamics remains critical. Scope of review This paper reviews the medical relevance of glycolytic pathway in depth and explores the current state of the art for monitoring and modelling the dynamics of the process. The future perspectives of label free, vibrational microspectroscopic techniques to overcome the limitations of the current approaches are considered. Major conclusions Vibrational microspectroscopic techniques can potentially operate in the niche area of limitations of other omics technologies for non-destructive, real-time, in vivo label-free monitoring of glycolysis dynamics at a cellular and subcellular level

The incidence of postoperative venous thrombosis among patients with ulcerative colitis

Background: Patients with Ulcerative Colitis (UC) have inherent prothrombotic tendencies. It is unknown whether this necessitates the use of additional perioperative anti-thrombotic prophylaxis when such patients require major surgery. Methods: The postoperative courses of 79 patients with UC undergoing 180 major abdominal and pelvic operations were examined for clinical and radiological evidence of venous thrombosis. Eighteen patients with Familial Adenomatous Polyposis (FAP) having surgery (35 operations) of similar magnitude were also studied. Standard anti-thrombosis prophylaxis was utilised in all patients. Results: Nine patients with UC were clinically suspected of developing postoperative venous thrombosis, but only three (3.8%) had their diagnosis confirmed radiologically (all had a pulmonary embolus). Therefore, the overall postoperative thrombosis rate, on an intention to treat basis, was 1.7% (3/180). No patient with FAP developed significant venous thrombosis. Conclusion: Standard perioperative antithrombotic modalities are sufficient to maintain any potential increase in postoperative thrombotic risk at an acceptable level in patients with UC undergoing operative intervention

Effect of electrospinning parameters on the mechanical and morphological characteristics of small diameter PCL tissue engineered blood vessel scaffolds having distinct micro and nano fibre populations – A DOE approach

Electrospinning is a widely used technique in tissue engineered blood vessel (TEBV) scaffold research. Successful TEBV scaffolds must be produced in a way that balances tissue-like mechanical characteristics with morphologies that promote cellularity by supporting cell attachment whilst also permitting cell infiltration. Electrospun tubular poly (ε-caprolactone) (PCL) scaffolds combining interspersed nano and micro fibre morphologies have shown promise in this regard. A comprehensive design of experiments (DOE) approach examines the effect of production parameters on the mechanical and morphological properties of small diameter PCL vascular scaffolds created using a single-step electrospinning process and comprised of multi-modal fibre populations. Mechanical properties of the vessels are assessed using a modified uniaxial ringlet tensile test method while morphological properties, including mean fibre diameter, degree of fibre alignment and porosity, are also captured. Regression analysis showed that a diverse range of mechanical properties could be achieved through the careful adjustment of processing conditions. Constructs with a broad range of ultimate tensile strengths (~4–10 MPa) and Young's moduli (~1.5–3 MPa) were prepared. The speed of the rotating collector system was found to be a dominant factor influencing both the mechanical and morphological attributes of the fabricated scaffolds. Several other main effects and interactions terms were found to influence the scaffold attributes, including degree of fibre orientation and mean fibre diameter. The potential applicability of particular tubular scaffolds for vascular applications were then evaluated by comparison with literature obtained mechanical property values for human coronary arteries and the great saphenous vein. This study demonstrates an important step towards a readily available and tailorable set of multi-modal PCL scaffold designs for further biological and clinical investigation

The Dichotomy of Vascular Smooth Muscle Differentiation/De- Differentiation in Health and Disease

Vascular smooth muscle cells (SMCs) are thought to display cellular plasticity by alternating between a quiescent ‘contractile’ differentiated phenotype and a proliferative ‘synthetic’ de-differentiated phenotype in response to induction of distinct developmental pathways or to local micro-environmental cues. This classic de-differentiation and re-programming process is associated with a significant loss in the expression of key SMC differentiation marker genes for a large number of proliferative vascular diseases in vivo and in sub-cultured cells in vitro. Regarded as essential for vascular regeneration and repair in vivo, phenotypic modulation represents a critical target for therapeutic intervention. However, recent evidence now suggests that this process of vascular regeneration may also involve differentiation of resident vascular stem cells and the accumulation of stem cell-derived myogenic, osteochondrogenic and macrophage-like phenotypes within vascular lesions in vivo and across sub-cultured SMC cell populations in vitro. This review summarises our current knowledge of vascular regeneration, de-differentiation and re-programming of vascular SMCs, and focuses on the accumulating evidence of a putative role for stem cell-derived progeny and the evolving dichotomy of the origin of SMC-like cells during intimal-medial thickening and the progression of arteriosclerotic disease

Native extracellular matrix orientation determines multipotent vascular stem cell proliferation in response to cyclic uniaxial tensile strain and simulated stent indentation

Cardiovascular disease is the leading cause of death worldwide, with multipotent vascular stem cells (MVSC) implicated in contributing to diseased vessels. MVSC are mechanosensitive cells which align perpendicular to cyclic uniaxial tensile strain. Within the blood vessel wall, collagen fibers constrain cells so that they are forced to align circumferentially, in the primary direction of tensile strain. In these experiments, MVSC were seeded onto the medial layer of decellularized porcine carotid arteries, then exposed to 10%, 1 Hz cyclic tensile strain for 10 days with the collagen fiber direction either parallel or perpendicular to the direction of strain. Cells aligned with the direction of the collagen fibers regardless of the orientation to strain. Cells aligned with the direction of strain showed an increased number of proliferative Ki67 positive cells, while those strained perpendicular to the direction of cell alignment showed no change in cell proliferation. A bioreactor system was designed to simulate the indentation of a single, wire stent strut. After 10 days of cyclic loading to 10% strain, MVSC showed regions of densely packed, highly proliferative cells. Therefore, MVSC may play a significant role in in-stent restenosis, and this proliferative response could potentially be controlled by controlling MVSC orientation relative to applied strain

Towards functional 3D-stacked electrospun composite scaffolds of PHBV, silk fibroin and nanohydroxyapatite: mechanical properties and surface osteogenic differentiation

Bone tissue engineering scaffolds have two challenging functional tasks to fulfil: to encourage cell proliferation, differentiation and matrix synthesis, and to provide suitable mechanical stability upon implantation. Composites of biopolymers and bioceramics combine the advantages of both types of materials, resulting in better processability, and enhanced mechanical and biological properties through matrix reinforcement. In the present study novel thick bone composite scaffolds were successfully fabricated using electrospun flat sheets of polyhydroxybutyrate - polyhydroxyvalerate (PHBV)/ nanohydroxyapatite (nHAp)/ silk fibroin essence (SF) (2% nHAp - 2% SF and 5% nHAp - 5% SF, respectively). Their potential as in vitro bone regeneration scaffolds was evaluated using mouse calvarian osteoblast cells (MC3T3-E1), in terms of morphology (SEM), cell attachment, cell proliferation, Col type I ( COL I), osteopontin (OSPN), and bone alkaline phosphatase (ALP) activity (Quantitative Real Time Polymerase Chain Reaction [qRT-PCR], enzyme linked immunosorbent assay, immunocytochemistry). Electrospun polyhydroxybutyrate–polyhydroxyvalerate scaffolds were used as reference constructs. The results showed that the compressive and tensile mechanical properties of the scaffolds are dependent on the change in their composition, and the treatment these underwent. Furthermore, methanol-treated and autoclaved P2 (2% nanohydroxyapatite, 2% silk fibroin essence) samples appeared to exhibit more promising tensile properties. Additionally, the compressive tests results confirmed that the methanol pre-treatment and the autoclaving step lead to an increase in the P2 secant modulus when compared to the non-methanol treated ones, P2 and P5 (5% nanohydroxyapatite, 5% silk fibroin essence), respectively. Both formulations of polyhydroxybutyrate–polyhydroxyvalerate/nanohydroxyapatite/silk fibroin essence composite promoted greater cell adhesion and proliferation than the corresponding polyhydroxybutyrate–polyhydroxyvalerate control ones. Cells seeded on the composite fibrous scaffolds were extensively expanded and elongated on the fibre surface after 1 day in culture, whereas those seeded on the polyhydroxybutyrate–polyhydroxyvalerate scaffolds were not completely elongated. In addition, cells grown on P2 and P5 scaffolds had higher ALP activity when compared to those containing no nanohydroxyapatite/silk fibroin

The impact of routine open nonsuction drainage on fluid accumulation after thyroid surgery: a prospective randomised clinical trial.

Background: Thyroid drains following thyroid surgery are routinely used despite minimal supportive evidence. Our aim in this study is to determine the impact of routine open drainage of the thyroid bed postoperatively on ultrasound-determined fluid accumulation at 24 hours. Methods: We conducted a prospective randomised clinical trial on patients undergoing thyroid surgery. Patients were randomly assigned to a drain group (n = 49) or a no-drain group (n = 44) immediately prior to wound closure. Patients underwent a neck ultrasound on day 1 and day 2 postoperatively. After surgery, we evaluated visual analogue scale pain scores, postoperative analgesic requirements, self-reported scar satisfaction at 6 weeks and complications. Results: There was significantly less mean fluid accumulated in the drain group on both day 1, 16.4 versus 25.1 ml (P-value = 0.005), and day 2, 18.4 versus 25.7 ml (P-value = 0.026), following surgery. We found no significant differences between the groups with regard to length of stay, scar satisfaction, visual analogue scale pain score and analgesic requirements. There were four versus one wound infections in the drain versus no-drain groups. This finding was not statistically significant (P = 0.154). No life-threatening bleeds occurred in either group. Conclusions: Fluid accumulation after thyroid surgery was significantly lessened by drainage. However, this study did not show any clinical benefit associated with this finding in the non-emergent setting. Drains themselves showed a trend indicating that they may augment infection rates. The results of this study suggest that the frequency of acute life-threatening bleeds remains extremely low following abandoning drains. We advocate abandoning routine use of thyroid drains. Trial registration: ISRCTN94715414

Differential effects of alcohol and its metabolite acetaldehyde on vascular smooth muscle cell Notch signaling and growth

Alcohol (EtOH) consumption can variously affect cardiovascular disease. Our aim was to compare the effects of EtOH and its primary metabolite acetaldehyde (ACT) on vascular smooth muscle Notch signaling and cell growth, which are important for atherogenesis. Human coronary artery smooth muscle cells (HCASMCs) were treated with EtOH (25 mM) or ACT (10 or 25 μM). As previously reported, EtOH inhibited Notch signaling and growth of HCASMCs. In contrast, ACT treatment stimulated HCASMC proliferation (cell counts) and increased proliferating cell nuclear antigen expression, concomitant with stimulation of Notch signaling, as determined by increased Notch receptor (N1 and N3) and target gene (Hairy-related transcription factor 1–3) mRNA levels. Interaction of the ligand with the Notch receptor initiates proteolytic cleavage by α- and γ-secretase, resulting in the release of the active Notch intracellular domain. Neither EtOH nor ACT had any significant effect on α-secretase activity. A fluorogenic peptide cleavage assay demonstrated almost complete inhibition by EtOH of Delta-like ligand 4-stimulated γ-secretase activity in solubilized HCASMCs (similar to the effect of the control inhibitor DAPT) but no effect of ACT treatment. EtOH, but not ACT, affected the association and distribution of the γ-secretase catalytic subunit presenilin-1 with lipid rafts, as determined by dual fluorescent labeling and confocal microscopic visualization. In conclusion, ACT stimulates vascular smooth muscle cell Notch signaling and growth, effects opposite to those of EtOH. These differential actions on vascular smooth muscle cells of EtOH and its metabolite ACT may be important in mediating the ultimate effects of drinking on cardiovascular disease