Transition from Propagating Polariton Solitons to a Standing Wave Condensate Induced by Interactions.

We explore phase transitions of polariton wave packets, first, to a soliton and then to a standing wave polariton condensate in a multimode microwire system, mediated by nonlinear polariton interactions. At low excitation density, we observe ballistic propagation of the multimode polariton wave packets arising from the interference between different transverse modes. With increasing excitation density, the wave packets transform into single-mode bright solitons due to effects of both intermodal and intramodal polariton-polariton scattering. Further increase of the excitation density increases thermalization speed, leading to relaxation of the polariton density from a solitonic spectrum distribution in momentum space down to low momenta, with the resultant formation of a nonequilibrium condensate manifested by a standing wave pattern across the whole sample.

Backward Cherenkov radiation emitted by polariton solitons in a microcavity wire.

Exciton-polaritons in semiconductor microcavities form a highly nonlinear platform to study a variety of effects interfacing optical, condensed matter, quantum and statistical physics. We show that the complex polariton patterns generated by picosecond pulses in microcavity wire waveguides can be understood as the Cherenkov radiation emitted by bright polariton solitons, which is enabled by the unique microcavity polariton dispersion, which has momentum intervals with positive and negative group velocities. Unlike in optical fibres and semiconductor waveguides, we observe that the microcavity wire Cherenkov radiation is predominantly emitted with negative group velocity and therefore propagates backwards relative to the propagation direction of the emitting soliton. We have developed a theory of the microcavity wire polariton solitons and of their Cherenkov radiation and conducted a series of experiments, where we have measured polariton-soliton pulse compression, pulse breaking and emission of the backward Cherenkov radiation.

Effective secondary fracture prevention: implementation of a global benchmarking of clinical quality using the IOF Capture the Fracture® Best Practice Framework tool.

UNLABELLED: Fracture Liaison Services are the best model to prevent secondary fractures. The International Osteoporosis Foundation developed a Best Practice Framework to provide a quality benchmark. After a year of implementation, we confirmed that a single framework with set criteria is able to benchmark services across healthcare systems worldwide. INTRODUCTION: Despite evidence for the clinical effectiveness of secondary fracture prevention, translation in the real-world setting remains disappointing. Where implemented, a wide variety of service models are used to deliver effective secondary fracture prevention. To support use of effective models of care across the globe, the International Osteoporosis Foundation's Capture the Fracture® programme developed a Best Practice Framework (BPF) tool of criteria and standards to provide a quality benchmark. We now report findings after the first 12 months of implementation. METHODS: A questionnaire for the BPF was created and made available to institutions on the Capture the Fracture website. Responses from institutions were used to assign gold, silver, bronze or black (insufficient) level of achievements mapped across five domains. Through an interactive process with the institution, a final score was determined and published on the Capture the Fracture website Fracture Liaison Service (FLS) map. RESULTS: Sixty hospitals across six continents submitted their questionnaires. The hospitals served populations from 20,000 to 15 million and were a mix of private and publicly funded. Each FLS managed 146 to 6200 fragility fracture patients per year with a total of 55,160 patients across all sites. Overall, 27 hospitals scored gold, 23 silver and 10 bronze. The pathway for the hip fracture patients had the highest proportion of gold grading while vertebral fracture the lowest. CONCLUSION: In the first 12 months, we have successfully tested the BPF tool in a range of health settings across the globe. Initial findings confirm a significant heterogeneity in service provision and highlight the importance of a global approach to ensure high quality secondary fracture prevention services.

The drain game: Abdominal drains for transverse rectus abdominis myocutaneous breast reconstruction.

INTRODUCTION: We recently published data for the duration of donor site drain use in latissimus dorsi and deep inferior epigastric perforator breast reconstruction, due to a reported requirement in the literature; evidence is still required for transverse rectus abdominis myocutaneous (TRAM) reconstruction. AIM: To compare inpatient hospital stay, drainage parameters and donor-site complications associated with closed suction abdominal drain removal by post-operative day (POD) 3 regardless of output (early group), versus after POD 3 where instructions were by drainage volume/24 h ± output consistency (late group), in post-mastectomy TRAM breast reconstruction. METHOD: A retrospective review of TRAM breast reconstructions, between June 2008-2013, was undertaken with a minimum 1 year follow-up per patient. RESULTS: Of 65 patients who underwent TRAM breast reconstruction, 56 hospital records contained complete documentation. Both the late (n = 35) and early (n = 21) drain removal group were matched for age and number of donor site drains (2 per patient). Mean drain removal day (5.34 ± 0.20 days vs. 2.67 ± 0.14 days; p < 0.0001), total drainage (797.86 ± 77.15 mls vs. 295.71 ± 29.72 mls; p < 0.0001) and hospital inpatient stay (7.46 ± 0.29 days vs. 6.09 ± 0.32 days; p = 0.003) were greater for patients in the late versus early group. There were no differences in total complications (5.71% (2/35) vs. 14.29% (3/21); p = 0.28), including seroma (2.86% (1/35) vs. 4.76% (1/21); p = 0.71) rates between the late and early groups. DISCUSSION: These data suggest significant advantages for patients who have abdominal drains removed early by POD 3, without increased post-operative complications including seroma rates; these data are in keeping with our LD data. We recommend drain removal by POD 3.

Spatial Patterns of Dissipative Polariton Solitons in Semiconductor Microcavities.

We report propagating bound microcavity polariton soliton arrays consisting of multipeak structures either along (x) or perpendicular (y) to the direction of propagation. Soliton arrays of up to five solitons are observed, with the number of solitons controlled by the size and power of the triggering laser pulse. The breakup along the x direction occurs when the effective area of the trigger pulse exceeds the characteristic soliton size determined by polariton-polariton interactions. Narrowing of soliton emission in energy-momentum space indicates phase locking between adjacent solitons, consistent with numerical modeling which predicts stable multihump soliton solutions. In the y direction, the breakup originates from inhomogeneity across the wave front in the transverse direction which develops into a stable array only in the solitonic regime via phase-dependent interactions of propagating fronts.

Describing variation in the delivery of secondary fracture prevention after hip fracture: an overview of 11 hospitals within one regional area in England.

SUMMARY: There is variation in how services to prevent second fractures after hip fracture are organised. We explored this in more detail at 11 hospitals. Results showed that there was unwarranted variation across a number of aspects of care. This information can be used to inform service delivery in the future. INTRODUCTION: Hip fractures are usually the result of low impact falls and underlying osteoporosis. Since the risk of further fractures in osteoporotic patients can be reduced by between 20 and 70 % with bone protection therapy, the NHS is under an obligation to provide effective fracture prevention services for hip fracture patients to reduce risk of further fractures. Evidence suggests there is variation in service organisation. The objective of the study was to explore this variation in more detail by looking at the services provided in one region in England. METHODS: A questionnaire was designed which included questions around staffing, models of care and how the four components of fracture prevention (case finding, osteoporosis assessment, treatment initiation and adherence (monitoring) were undertaken. We also examined falls prevention services. Clinicians involved in the delivery of osteoporosis services at 11 hospitals in one region in England completed the questionnaire. RESULTS: The service overview showed significant variation in service organisation across all aspects of care examined. All sites provided some form of case finding and assessment. However, interesting differences arose when we examined how these components were structured. Eight sites generally initiated treatment in an inpatient setting, two in outpatients and one in primary care. Monitoring was undertaken by secondary care at seven sites and the remainder conducted by GPs. CONCLUSIONS: The variability in service provision was not explained by local variations in care need. Further work is now needed to establish how the variability in service provision affects key patient, clinical and health economic outcomes.

The drain game: abdominal drains for deep inferior epigastric perforator breast reconstruction.

INTRODUCTION: The deep inferior epigastric perforator (DIEP) flap is often preferred for breast reconstruction as it allows for autologous reconstruction with less donor site morbidity versus transverse rectus abdominis myocutaneous (TRAM) flap reconstruction. Our group has presented and published data for the duration of donor site back drain use in latissimus dorsi (LD) flap breast reconstruction due to insufficient evidence and a requirement for further investigation in the literature; this evidence is still lacking for DIEP reconstruction. AIM: To compare inpatient hospital stay, drainage parameters and donor-site complications associated with closed suction abdominal drain removal by post-operative day (POD) 3 regardless of output (early group), with removal after POD 3 where instructions were by drainage volume/24 h±output consistency (late group), in post-mastectomy DIEP reconstruction donor sites. METHOD: A retrospective review of DIEP breast reconstructions, between January 2011 and July 2012, was undertaken to facilitate 1 year minimum follow-up per patient. RESULTS: Of 78 patients who underwent DIEP breast reconstructions, 74 hospital records contained complete documentation. There were 41 patients in the late, and 33 in the early removal group; both groups were matched for age and number of donor site drains (2 per patient). Mean drain removal day (4.32±0.10 days vs. 2.87±0.06 days, p<0.0001), total drainage (518.90±41.53 mls vs. 283.79±18.06 mls; p<0.0001) and hospital inpatient stay were greater for patients in the late versus early group. There were no differences in total complications (21.95% (9/41) vs. 12.12% (5/33); p=0.46), seroma (4.88% (2/41) vs. 0% (0/33); p=0.20), dehiscence (4.88% (2/41) vs. 9.09% (3/33); p=0.47) or haematoma (7.32% (3/41) vs. 3.0% (1/33); p=0.42) rates between the late and early groups. DISCUSSION: These data suggest significant advantages for patients who have abdominal drains removed early by POD 3, without increased post-operative complications including seroma rates; these data are in keeping with our LD data. We recommend drain removal and patient discharge by POD 3.

Effects of spin-dependent interactions on polarization of bright polariton solitons.

We report on the spin properties of bright polariton solitons supported by an external pump to compensate losses. We observe robust circularly polarized solitons when a circularly polarized pump is applied, a result attributed to phase synchronization between nondegenerate TE and TM polarized polariton modes at high momenta. For the case of a linearly polarized pump, either σ+ or σ- circularly polarized bright solitons can be switched on in a controlled way by a σ+ or σ- writing beam, respectively. This feature arises directly from the widely differing interaction strengths between co- and cross-circularly polarized polaritons. In the case of orthogonally linearly polarized pump and writing beams, the soliton emission on average is found to be unpolarized, suggesting strong spatial evolution of the soliton polarization. The observed results are in agreement with theory, which predicts stable circularly polarized solitons and unstable linearly polarized solitons.

The drain game: back drains for latissimus dorsi breast reconstruction.

INTRODUCTION: The pedicled latissimus dorsi myocutaneous (LD) flap is a popular breast reconstruction choice, representing approximately 50% of procedures undertaken in the UK. Donor site drain use may reduce complication rates, however no evidence exists regarding the duration of back drain use for LD flap breast reconstruction and calls have been made in the literature to investigate this further. AIM: To compare inpatient hospital stay, drainage parameters and donor-site complications associated with closed suction back drain removal by post-operative day (POD) 3 regardless of output (early group), with removal after POD 3 where instructions were documented by drainage volume/24 h ± output consistency (late group), in post-mastectomy LD reconstruction donor sites. METHOD: A retrospective review of LD breast reconstruction procedures, performed between January 2010 and July 2011, was undertaken to ensure 1 year minimum follow-up per patient. RESULTS: There were 81 patients who underwent unilateral LD breast reconstructions; 78 hospital records contained complete documentation. There were 48 patients in the late removal group and 30 patients in the early removal group. The mean drain removal day (5.42 ± 0.17 days vs. 2.87 ± 0.06 days, p < 0.001), total drainage (907.71 ± 76.07 ml vs. 492.67 ± 35.15 ml, p < 0.0001) and hospital inpatient stay (4.60 ± 0.19 days vs. 3.63 ± 0.17 days, p < 0.001) were greater for patients in the late group, versus the early group. There were no differences in total complications (16.67%(8/48) vs. 10%(3/30), p = 0.41), seroma (6.25%(3/48) vs. 6.67%(2/30), p = 0.94), dehiscence (4.17%(2/48) vs. 3.33%(1/30), p = 0.85) or haematoma rates (10.42%(5/48) vs. 0%(0/30), p = 0.07) between patients in the late and early groups; seroma sub-analysis also indicated no differences in number of seroma aspirations, duration of drainage (months) and mean total drainage (ml) prior to resolution. DISCUSSION: These data suggest significant advantages for patients who have back drains removed by POD 3, without increased post-operative complications including seroma rates, and we recommend drain removal and patient discharge by POD 3.

Survival of a pedicled latissimus dorsi flap in breast reconstruction without a thoracodorsal pedicle.

The latissimus dorsi flap, first performed by Tansini in 1892, was popularised for use by Olivari in 1976. The successful transfer of a latissimus dorsi flap during breast reconstruction has previously been thought to be dependent on having an intact thoracodorsal pedicle to ensure flap survival. It is well documented that the flap may also survive on the serratus branch in thoracodorsal pedicle division. We report a case of a 52-year-old female patient who underwent successful delayed breast reconstruction with a latissimus dorsi flap following previous mastectomy and axillary node clearance. Intraoperatively, the thoracodorsal pedicle and serratus branch were found to have been previously divided. On postoperative computer tomographic angiography the thoracodorsal pedicle was shown to be divided together with the serratus branch. The flap was seen to be supplied by the lateral thoracic artery. To our knowledge survival of a pedicled latissimus dorsi flap in breast reconstruction with a vascular supply from this vessel following thoracodorsal pedicle division has not previously been described. Previous thoracodorsal pedicle and serratus branch division may not be an absolute contraindication for the use of the latissimus dorsi flap in breast reconstruction, depending on the results of preoperative Doppler or computer tomographic angiography studies.

Bedside testing for myasthenia gravis: the ice-test.

A 67-year-old man presented to the acute medical take with a history of droopy eyelids and difficulty swallowing. A diagnosis of myasthenia gravis was suspected from the clinical history. The patient's symptoms were progressive, raising concerns of aspiration pneumonia or respiratory compromise if untreated. Definitive diagnosis of myasthenia gravis relies upon a combination of serological and electrophysiological investigations, the results of which are not immediately available in an acute situation. Bedside tests are therefore of practical clinical importance to enable prompt and effective initiation of treatment, particularly where critical symptoms are present. The ice-test is a straightforward and non-invasive investigation with a high sensitivity for myasthenia gravis and is a useful alternative to edrophonium testing. It is especially helpful in patients with cardiac and respiratory co-morbidities for whom acetylcholinesterase inhibitors are contraindicated. We describe a case where this simple bedside test successfully expedited the correct treatment and improved patient care.

Intercostal adipofascial perforator flap for reconstruction of overcorrected gynaecomastia deformity.

The intercostal perforator fasciocutaneous flap has previously been described in addressing defects in the breast, trunk and arm 1,2,. We describe the first case of an inter-costal artery perforator adipofascial flap in the reconstruction of the male chest following overcorrection of gynaecomastia.

Bedside testing for myasthenia gravis: the ice-test.

A 67-year-old man presented to the acute medical take with a history of droopy eyelids and difficulty swallowing. A diagnosis of myasthenia gravis was suspected from the clinical history. The patient's symptoms were progressive, raising concerns of aspiration pneumonia or respiratory compromise if untreated. Definitive diagnosis of myasthenia gravis relies upon a combination of serological and electrophysiological investigations, the results of which are not immediately available in an acute situation. Bedside tests are therefore of practical clinical importance to enable prompt and effective initiation of treatment, particularly where critical symptoms are present. The ice-test is a straightforward and non-invasive investigation with a high sensitivity for myasthenia gravis and is a useful alternative to edrophonium testing. It is especially helpful in patients with cardiac and respiratory co-morbidities for whom acetylcholinesterase inhibitors are contraindicated. We describe a case where this simple bedside test successfully expedited the correct treatment and improved patient care.

Muscle herniation: a complication at the anterolateral thigh perforator flap donor site.

The anterolateral perforator flap is becoming the flap of choice for a wide variety of complex defects. It has been known to provide excellent donor site morbidity even in cases where vastus lateralis is included within the flap. We report a case of herniation of the vastus lateralis and rectus femoris muscles through the overlying fascia, following ALT perforator flap harvest. In this case muscle herniation at the donor site required surgical repair.

A prospective analysis of c-myc oncoprotein levels as a prognostic marker in malignant melanoma.

BACKGROUND: Previous studies from our group had identified c-myc oncoprotein expression as an important prognostic parameter in a series of retrospective studies of primary and metastatic melanoma and other variants of this disease. This study set out to prospectively evaluate the prognostic significance of c-myc positivity in a consecutive series of primary melanomas presenting at Mount Vernon Hospital Regional Plastic Surgery and Burns Centre. METHODS: A consecutive series of 117 primary melanomas underwent flow cytometric analysis for c-myc expression at diagnosis. Routine clinical and histological parameters were collected from each patient's clinical records and survival assessed. The mean follow up was 45 months. RESULTS: Kaplan-Meier survival analysis demonstrated that Breslow depth, histogenic subtype, ulceration, age and sex had prognostic significance. Survival analysis revealed high c-myc positivity to be significantly associated with poorer outcome (P<0.043). Each of the main prognostic parameters were assessed for their independent significance using Cox Proportional Hazards; only c-myc retained independent significance (P<0.039). CONCLUSIONS: The strength of this study is that it was performed in a consecutive series of patients followed up in a longitudinal prospective study. c-myc was not the strongest predictor of survival in univariate analysis, but was the only parameter that retained significance in multivariate analysis.

Normalization of factor VIII levels in a patient with mild haemophilia A during a 35-year period.

We report the case of a 45-year-old man who was diagnosed in June 1969 9 years old as having mild haemophilia A following a traumatic left shoulder bleed when his factor VIII (FVIII) activity was 11 IU dL(-1) based on a two-stage assay. The bleed resolved following treatment with intravenous cryoprecipitate. There was no family history of haemophilia. Cryoprecipitate infusions were required to treat further traumatic bleeds between 1971 and 1981. During this time, his FVIII activity was confirmed at 14 IU dL(-1). He defaulted many hospital appointments until 1991 when his FVIII activity had risen to 42 IU dL(-1). There was no evidence of infection, inflammatory or liver disease to account for this change. By 2005 he had a normal FVIII activity of 62 IU dL(-1) based on a one-stage assay. FVIII gene analysis confirmed a codon 531 mutation. It appeared that the discrepant FVIII results related to whether a two-stage or one-stage assay was used that has been previously reported for other patients with these mutations. We felt it important to raise awareness that this phenomenon may lead to apparent correction of haemophilia A.

An unusual complication of ice skating and the emergence of a previously undiagnosed bleeding disorder.

We report the case of an 8-year-old boy with no prior abnormal bleeding history who presented with severe central abdominal pain following a freak accident at a local ice rink. Clinical examination confirmed a tender periumbilical mass. An ultrasound scan confirmed a large haemorrhagic fluid collection adjacent to the second part of his duodenum that was causing a subacute small-bowel obstruction. He was found to have a persistently prolonged prothrombin time between 17.3 and 18.1 s but normal liver function tests. There was no suggestion of dietary vitamin K deficiency. Further investigations confirmed factor VII deficiency with levels between 30.4 and 33.6 IU dL-1. His prothrombin time did not normalize with intravenous vitamin K. He was subsequently treated with three 30 microg kg-1 body weight doses of novoseven at 4-h interval and made an excellent recovery. The haematoma virtually resolved completely confirmed by a follow-up ultrasound scan 3 months after the initial event.

The relation between c-myc expression and interferon sensitivity in uveal melanoma.

BACKGROUND/AIM: Interferons (IFN) are currently being used to treat melanoma, including some patients with uveal melanoma. IFN is thought to inhibit tumour growth through downregulation of the c-myc oncogene; the overexpression of which has been shown to be associated with resistance in cell lines. The aim of this study was to investigate the relation between c-myc gene expression and IFN sensitivity in a series of uveal melanomas in a short term chemosensitivity assay. METHODS: Tumours from 45 patients with uveal melanoma who had undergone enucleation were studied. The ATP chemosensitivity assay was used to study sensitivity to IFN-alpha-2b in freshly isolated cells from each tumour. Flow cytometry was used to assess c-myc expression in formalin fixed material from the primary specimens. RESULTS: There was a wide range of IFN sensitivity between the specimens whereas c-myc expression was universal and present in 80% of the tumour cells in 80% of the specimens. Higher c-myc expression was associated with IFN-alpha resistance as measured by the maximum percentage of inhibition (p = 0.05) and there was a trend with the IFN sensitivity index (p = 0.07). CONCLUSIONS: These results demonstrate that tumours with high c-myc expression are also associated with IFN resistance. Future research is required to explore the potential of c-myc gene manipulation combined with IFN therapy.

A new incision for surgery on tendo Achillis using a distally-based fasciocutaneous flap.

The consequences of breakdown of the wound after surgery to tendo Achillis are considerable. Complex surgery is often required to reconstruct the tendon and to provide soft-tissue cover. We describe a new incision which approaches the tendon by using a distally-based fasciocutaneous flap. This reduces the risk of breakdown of the wound since it avoids making an incision directly over the tendon, provides good exposure, and maintains the vascularity of the skin overlying the tendon.

The c-myc oncogene: use of a biological prognostic marker as a potential target for gene therapy in melanoma.

The c-myc oncogene has been shown to be overexpressed in a number of malignancies, and may play an important role in the pathogenesis of malignant melanoma. Previous prognostic studies have demonstrated c-myc overexpression in a range of cutaneous melanomas, and levels of c-myc oncoprotein expression have been shown to correlate with clinical outcome in both primary and secondary disease. The purpose of this study was to investigate the in vitro manipulation of c-myc expression using antisense oligonucleotides. The human melanoma cell lines A375M, Be11 and WM115 were treated with c-myc antisense oligonucleotides, and the cellular growth was compared with controls. Antisense oligonucleotides reduced the growth rate of all three cell lines, and produced a reduction in c-myc gene expression as measured by flow cytometry. The growth inhibitions in the A375M, Be11 and WM115 cell lines at 72 h were 36.6%, 35.8% and 29.3%, respectively. Each of these was significantly different from control cultures (P<0.01). The c-myc antisense produced a mean 75% reduction in c-myc oncoprotein expression when compared with controls in the A375M cells (P<0.001), a 49% reduction in the Be11 cells (P<0.001) and a 28% reduction in the WM115 cells (P=0.005). This study demonstrates the importance of the c-myc oncogene in controlling melanoma growth. It suggests that blocking the expression of this gene, using an antisense approach, reduces melanoma cell growth, and may potentially provide a novel gene-therapy strategy for the treatment of advanced melanoma.