Publications by authors named "Stephen Parsons"

Thoracic splenosis is a rare condition referring to the auto-transplantation of splenic tissue into the thoracic cavity following splenic trauma. We present a case of thoracic splenosis in a 62-year-old man who at the age of 17 suffered three gunshot wounds to the posterior thorax and abdomen, requiring a splenectomy and intercostal catheter insertion. In 2007, he underwent a thoracotomy and biopsy of a left sided pulmonary mass which was complicated by a haemothorax requiring an emergent return to theatre and rib resection to achieve haemostasis.

View Article and Find Full Text PDF

Endoscopic resection of tarsal coalitions is technically feasible for both talocalcaneal and calcaneonavicular coalitions. Careful consideration of each individual patient is necessary before proceeding with endoscopic resection. Endoscopic resection of these coalitions may offer benefits in terms of faster recovery and less wound problems, but this has not been proven.

View Article and Find Full Text PDF

Mechanisms driving resistance to cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) in hormone receptor-positive (HR) breast cancer have not been clearly defined. Whole-exome sequencing of 59 tumors with CDK4/6i exposure revealed multiple candidate resistance mechanisms including loss, activating alterations in , and , and loss of estrogen receptor expression. experiments confirmed that these alterations conferred CDK4/6i resistance.

View Article and Find Full Text PDF

Fatigue has been proposed to increase the risk of knee injury. This study tracked countermovement jump, knee isometric strength, and kinetics and kinematics in 8 female soccer players (experimental group) during an anticipated sidestep maneuver before and after two matches played over a 43-h period. Time points were: Before and after match 1 (T0 and T1), 12 h after the first match (T2), and immediately after the second match (T3).

View Article and Find Full Text PDF

The noninvasive digital restoration of ancient texts written in carbon black ink and hidden inside artifacts has proven elusive, even with advanced imaging techniques like x-ray-based micro-computed tomography (micro-CT). This paper identifies a crucial mistaken assumption: that micro-CT data fails to capture any information representing the presence of carbon ink. Instead, we show new experiments indicating a subtle but detectable signature from carbon ink in micro-CT.

View Article and Find Full Text PDF

Loss-of-function mutations in the retinoblastoma gene are common in several treatment-refractory cancers such as small-cell lung cancer and triple-negative breast cancer. To identify drugs synthetic lethal with mutation ( ), we tested 36 cell-cycle inhibitors using a cancer cell panel profiling approach optimized to discern cytotoxic from cytostatic effects. Inhibitors of the Aurora kinases AURKA and AURKB showed the strongest association in this assay.

View Article and Find Full Text PDF

Objectives: Gastro-oesophageal reflux disease (GORD) is both common and troubling with a prevalence of 20-40%. We assessed the utility of a scintigraphic reflux study to evaluate the oesophageal and extra-oesophageal manifestation of disease compared to the standard tests such as pH monitoring and manometry.

Methods: Patients were recruited into a prospective database of referrals to a tertiary referral center for either resistance to maximal medical therapy or extra-oesophageal symptoms of GORD.

View Article and Find Full Text PDF

Introduction: Lateral malleolus non-union can cause pain and loss of function. Standard treatment involves open approach with debridement, bone-grafting and plate stabilisation, with published surgical site infection rates to 17%. To minimise the risk of soft tissue complications and allow early mobilisation, we describe a technique for percutaneous cannulated screw stabilisation.

View Article and Find Full Text PDF

The generation of cultured red blood cells from stem cell sources may fill an unmet clinical need for transfusion-dependent patients, particularly in countries that lack a sufficient and safe blood supply. Cultured red blood cells were generated from human CD34 cells from adult peripheral blood or cord blood by expansion, and a comprehensive survival comparison with standard red cell concentrates was undertaken. Significant amplification (>10-fold) was achieved using CD34 cells from both cord blood and peripheral blood, generating high yields of enucleated cultured red blood cells.

View Article and Find Full Text PDF

Arthroscopic approaches to subtalar, double, and triple arthrodesis allow relative preservation of the soft tissue envelope compared with traditional open approaches. The surgical technique involving the use of a 4.5-mm 30° arthroscope via sinus tarsi portals is described.

View Article and Find Full Text PDF

Objectives: Stroke rehabilitation best practices recommend interventions to address individual deficits, guided by a comprehensive assessment to identify specific impairments. The relationship of motor impairments to balance has been well investigated, but the role of impaired plantar cutaneous sensation is less understood, despite the fact that 41% of individuals post-stroke have this deficit. The study objectives were to (1) characterize the relationship between plantar sensation and measures of standing balance control and (2) determine the threshold of sensory impairment related to balance impairment post-stroke.

View Article and Find Full Text PDF

This paper describes the background to the development, implementation, and subsequent management of a programme of peer review of Pediatric Diabetes Centres belonging to the SWEET Group The paper summarizes the overall purpose of the programme, lists the principles upon which the programme is founded, and sets out the intended outcomes of the programme Details are given of the way in which the programme is delivered and summarizes the key findings from the 16 centres reviewed to date Finally the paper highlights the feedback that has been received from those who have been reviewed and those who have acted as reviewers and discusses ways in which the programme can be further developed in the future.

View Article and Find Full Text PDF

Disorders of the hallux sesamoids can be a source of considerable pain and disability. Inappropriate or inept removal can lead to further disability and pain. Surgical intervention should only follow careful accurate assessment, appropriate investigation, and failure of conservative treatments.

View Article and Find Full Text PDF

p38α mitogen-activated protein kinase (MAPK) is activated in cancer cells in response to environmental factors, oncogenic stress, radiation, and chemotherapy. p38α MAPK phosphorylates a number of substrates, including MAPKAP-K2 (MK2), and regulates the production of cytokines in the tumor microenvironment, such as TNF-α, interleukin-1β (IL-1β), IL-6, and CXCL8 (IL-8). p38α MAPK is highly expressed in human cancers and may play a role in tumor growth, invasion, metastasis, and drug resistance.

View Article and Find Full Text PDF

The proliferation and terminal differentiation of erythroid progenitors occurs in human bone marrow within erythroblastic islands, specialised structures consisting of a central macrophage surrounded by developing erythroid cells. Many cell-cell and cell-matrix adhesive interactions maintain and regulate the co-ordinated daily production of reticulocytes. Erythroid cells express only one integrin, α4β1, throughout differentiation, and its interactions with both macrophage Vascular Cell Adhesion Molecule-1 and with extracellular matrix fibronectin are critical for erythropoiesis.

View Article and Find Full Text PDF

Background: Symptomatic tarsal coalitions failing conservative treatment are traditionally managed by open resection. We describe an arthroscopic technique for excising talocalcaneal coalitions and present a retrospective two-surgeon case series of the first eight patients (nine feet).

Methods: Outcome measures include restoration of subtalar movements, return to work and sports, visual analogue pain scales and Sports Athlete Foot and Ankle Scores (SAFAS).

View Article and Find Full Text PDF

Wholesale depletion of membrane organelles and extrusion of the nucleus are hallmarks of mammalian erythropoiesis. Using quantitative EM and fluorescence imaging we have investigated how autophagy contributes to organelle removal in an ex vivo model of human erythroid differentiation. We found that autophagy is induced at the polychromatic erythroid stage, and that autophagosomes remain abundant until enucleation.

View Article and Find Full Text PDF

Background: Calcaneonavicular coalition represents abnormal coalescence between calcaneus and navicular bone. It is a congenital anomaly, sometimes becoming symptomatic in young adolescent. This is managed conservatively initially, failing which surgical excision, open or arthroscopic, is considered.

View Article and Find Full Text PDF

Background: Self-assembling peptides that form nanostructured hydrogels are important biomaterials for tissue engineering scaffolds. The P₁₁-family of peptides includes, P₁₁-4 (QQRFEWEFEQQ) and the complementary peptides P₁₁-13 (EQEFEWEFEQE) and P₁₁-14 (QQOrnFOrnWOrnFOrnQQ). These form self-supporting hydrogels under physiological conditions (pH 7.

View Article and Find Full Text PDF

The maturation of reticulocytes into functional erythrocytes is a complex process requiring extensive cytoplasmic and plasma membrane remodeling, cytoskeletal rearrangements and changes to cellular architecture. Autophagy is implicated in the sequential removal of erythroid organelles during erythropoiesis, although how this is regulated during late stages of erythroid differentiation, and the potential contribution of autophagy during reticulocyte maturation, remain unclear. Using an optimized ex vivo differentiation system for human erythropoiesis, we have observed that maturing reticulocytes are characterized by the presence of one or few large vacuolar compartments.

View Article and Find Full Text PDF

The erythrocyte is one of the best characterized human cells. However, studies of the process whereby human reticulocytes mature to erythrocytes have been hampered by the difficulty of obtaining sufficient numbers of cells for analysis. In the present study, we describe an in vitro culture system producing milliliter quantities of functional mature human adult reticulocytes from peripheral blood CD34(+) cells.

View Article and Find Full Text PDF

The Atg4 cysteine proteases play crucial roles in the processing of Atg8 proteins during autophagy, but their regulation during cellular stress and differentiation remains poorly understood. We have found that two Atg4 family members--Atg4C and Atg4D--contain cryptic mitochondrial targeting sequences immediately downstream of their canonical (DEVD) caspase cleavage sites. Consequently, caspase-cleaved Atg4D (ΔN63 Atg4D) localizes to the mitochondrial matrix when expressed in mammalian cells, where it undergoes further processing to a ~42 kDa mitochondrial form.

View Article and Find Full Text PDF

Activation of the translation initiation factor 4E (eIF4E) promotes malignant transformation and metastasis. Signaling through the AKT-mTOR pathway activates eIF4E by phosphorylating the inhibitory 4E binding proteins (4E-BP). This liberates eIF4E and allows binding to eIF4G.

View Article and Find Full Text PDF