Spontaneous Ca2+ transients in rat pulmonary vein cardiomyocytes are increased in frequency and become more synchronous following electrical stimulation.

The pulmonary veins have an external sleeve of cardiomyocytes that are a widely recognised source of ectopic electrical activity that can lead to atrial fibrillation. Although the mechanisms behind this activity are currently unknown, changes in intracellular calcium (Ca2+) signalling are purported to play a role. Therefore, the intracellular Ca2+ concentration was monitored in the pulmonary vein using fluo-4 and epifluorescence microscopy. Electrical field stimulation evoked a synchronous rise in Ca2+ in neighbouring cardiomyocytes; asynchronous spontaneous Ca2+ transients between electrical stimuli were also present. Immediately following termination of electrical field stimulation at 3 Hz or greater, the frequency of the spontaneous Ca2+ transients was increased from 0.45 ± 0.06 Hz under basal conditions to between 0.59 ± 0.05 and 0.65 ± 0.06 Hz (P < 0.001). Increasing the extracellular Ca2+ concentration enhanced this effect, with the frequency of spontaneous Ca2+ transients increasing from 0.45 ± 0.05 Hz to between 0.75 ± 0.06 and 0.94 ± 0.09 Hz after electrical stimulation at 3 to 9 Hz (P < 0.001), and this was accompanied by a significant increase in the velocity of Ca2+ transients that manifested as waves. Moreover, in the presence of high extracellular Ca2+, the spontaneous Ca2+ transients occurred more synchronously in the initial few seconds following electrical stimulation. The ryanodine receptors, which are the source of spontaneous Ca2+ transients in pulmonary vein cardiomyocytes, were found to be arranged in a striated pattern in the cell interior, as well as along the periphery of cell. Furthermore, labelling the sarcolemma with di-4-ANEPPS showed that over 90% of pulmonary vein cardiomyocytes possessed T-tubules. These findings demonstrate that the frequency of spontaneous Ca2+ transients in the rat pulmonary vein are increased following higher rates of electrical stimulation and increasing the extracellular Ca2+ concentration.

Routine pre- and post-neoadjuvant chemotherapy fitness testing is not indicated for oesophagogastric cancer surgery.

Introduction There is a known correlation between anaerobic threshold (AT) during cardiopulmonary exercise testing and development of cardiopulmonary complications in high-risk patients undergoing oesophagogastric cancer surgery. This study aimed to assess the value of routine retesting following neoadjuvant chemotherapy. Methods Patients undergoing neoadjuvant chemotherapy with subsequent oesophagogastric cancer surgery with pre- and post-neoadjuvant chemotherapy cardiopulmonary exercise data were identified from a prospectively maintained database. Measured cardiopulmonary exercise variables included AT and maximum oxygen uptake at peak exercise (VO2 peak). Anaerobic threshold values within 1 ml/kg/minute were considered static. Patients were grouped into AT ranges of less than 9 ml/kg/minute, 9-11 ml/kg/minute and greater than 11 ml/kg/minute. Outcome measures were unplanned intensive care stay, postoperative cardiovascular morbidity and mortality. Results Between May 2008 and August 2017, 42 patients from 675 total resections were identified, with a mean age of 65 years (range 49-84 years). Mean pre-neoadjuvant chemotherapy AT was 11.07 ml/kg/minute (standard deviation, SD, 3.24 ml/kg/minute, range 4.6-19.3 ml/kg/minute) while post-neoadjuvant chemotherapy AT was 11.19 ml/kg/minute (SD 3.05 ml/kg/minute, range 5.2-18.1 ml/kg/minute). Mean pre-neoadjuvant chemotherapy VO2 peak was 17.13 ml/kg/minute, while post-chemotherapy this mean fell to 16.59 ml/kg/minute. Some 44.4% of patients with a pre-chemotherapy AT less than 9 ml/kg/minute developed cardiorespiratory complications compared with 42.2% of those whose AT was greater than 9 ml/kg/minute (P = 0.914); 63.6% of patients in the post-neoadjuvant chemotherapy group with an AT less than 9 ml/kg/minute developed cardiorespiratory complications. There was no correlation between direction of change in AT and outcome. Conclusion In our patient population, neoadjuvant chemotherapy does not appear to result in a significant mean reduction in cardiorespiratory fitness. Routine pre- and post-neoadjuvant chemotherapy cardiopulmonary exercise testing is currently not indicated; however, larger studies are required to demonstrate this conclusively.

Comparison of endoscopic laser therapy and self expanding metal stents for palliation in patients with non-resectable oesophageal carcinoma.

BACKGROUND: There are currently limited data on the comparative success of endoscopic laser therapy (NLT) and self expanding metal stents (SEMS) as palliative measures in patients with non-resectable oesophageal cancer. This study aims to assess and compare the outcomes of these methods of endoscopic palliation. METHODS: Patients with non-curative oesophageal/gastro-oesophageal cancers with dysphagia were identified prospectively and consented to swallow assessment and follow-up. Patients underwent SEMS or NLT at the discretion of the treating endoscopist. Initial standardised swallow scores (0-4) were assessed. All subsequent interventions were recorded as well as survival. RESULTS: 31 patients were recruited (30M vs 8F, mean age 70.8). There was no significant difference in age, sex or chemotherapy treatment between groups. 19(61%)patients underwent NLT as primary procedure. 20(64.5%) patients required subsequent intervention(s) (median 1, range 0-8). Primary NLT patients were more likely to require subsequent therapy (p = 0.004) and multiple procedures (p = 0.001). 8(42.1%)patients initially undergoing NLT subsequently required SEMS, while no SEMS patients underwent subsequent NLT. Swallow scores of 1 or 2 were more likely to be maintained with NLT while scores of 3 or 4 were more likely to progress to SEMS (p = 0.039). Time to repeat procedure was greater in the SEMS group (p = 0.001). Median survival was 133 days for NLT vs 60 days for SEMS (p = 0.412). CONCLUSION: In this series, patients selected for NLT had a trend towards longer survival, but were more likely to require repeated procedures. Those with lower early initial dysphagia scores were more likely to be maintained by NLT alone.

A comparison of the left thoracoabdominal and Ivor-Lewis esophagectomy.

The purpose of this study was to assess the oncological outcomes of a large multicenter series of left thoracoabdominal esophagectomies, and compare these to the more widely utilized Ivor-Lewis esophagectomy. With ethics approval and an established study protocol, anonymized data from five centers were merged into a structured database. The study exposure was operative approach (ILE or LTE). The primary outcome measure was time to death. Secondary outcome measures included time to tumor recurrence, positive surgical resection margins, lymph node yield, postoperative death, and hospital length of stay. Cox proportional hazards models provided hazard ratios (HR) with 95% confidence intervals (CI) adjusting for age, pathological tumor stage, tumor grade, lymphovascular invasion, and neoadjuvant treatment. Among 1228 patients (598 ILE; 630 LTE), most (86%) had adenocarcinoma (AC) and were male (81%). Comparing ILE and LTE for AC patients, no difference was seen in terms of time to death (HR 0.904 95%CI 0.749-1.1090) or time to recurrence (HR 0.973 95%CI 0.768-1.232). The risk of a positive resection margin was also similar (OR 1.022 95%CI 0.731-1.429). Median lymph node yield did not differ between approaches (LTE 21; ILE 21; P = 0.426). In-hospital mortality was 2.4%, significantly lower in the LTE group (LTE 1.3%; ILE 3.6%; P = 0.004). Median hospital stay was 11 days in the LTE group and 14 days in the ILE group (P < 0.0001). In conclusion, this is the largest series of left thoracoabdominal esophagectomies to be submitted for publication and the only one to compare two different transthoracic esophagectomy strategies. It demonstrates oncological equivalence between operative approaches but possible short- term advantages to the left thoracoabdominal esophagectomy.

The relationship between adiposity, bone density and microarchitecture is maintained in young women irrespective of diabetes status.

BACKGROUND: The relationship between bone health and adiposity and how it may be affected in people with chronic metabolic conditions is complex. METHODS: Seventeen women with type 1 diabetes mellitus (T1DM) and nine age-matched healthy women with a median age of 22.6 years (range, 17.4, 23.8) were studied by 3T MRI and MR spectroscopy to assess abdominal adiposity, tibial bone microarchitecture and vertebral bone marrow adiposity (BMA). Additional measures included DXA-based assessments of total body (TB), femoral neck (FN) and lumbar spine (LS) bone mineral density (BMD) and fat mass (FM). RESULTS: Although women with T1DM had similar BMI and BMA to the controls, they had higher visceral and subcutaneous adiposity on MRI (P<.05) and total body FM by DXA (P=.03). Overall, in the whole cohort, a clear inverse association was evident between BMA and BMD at all sites (P<.05). These associations remained significant after adjusting for age, BMI, FM and abdominal adiposity. In addition, visceral adiposity, but not subcutaneous adiposity, showed a positive association with BMA (r, .4, P=.03), and a negative association with total body BMD (r, .5, P=.02). Apparent trabecular separation as assessed by MRI showed an inverse association to total body BMD by DXA (r, -.4, P=.04). CONCLUSION: Irrespective of the presence of an underlying metabolic condition, young women display a negative relationship between MRI-measured BMA and DXA-based assessment of BMD. Furthermore, an association between BMA and visceral adiposity supports the notion of a common origin of these two fat depots.

Optical and radiometric models of the NOMAD instrument part II: the infrared channels - SO and LNO.

NOMAD is a suite of three spectrometers that will be launched in 2016 as part of the joint ESA-Roscosmos ExoMars Trace Gas Orbiter mission. The instrument contains three channels that cover the IR and UV spectral ranges and can perform solar occultation, nadir and limb observations, to detect and map a wide variety of Martian atmospheric gases and trace species. Part I of this work described the models of the UVIS channel; in this second part, we present the optical models representing the two IR channels, SO (Solar Occultation) and LNO (Limb, Nadir and Occultation), and use them to determine signal to noise ratios (SNRs) for many expected observational cases. In solar occultation mode, both the SO and LNO channel exhibit very high SNRs >5000. SNRs of around 100 were found for the LNO channel in nadir mode, depending on the atmospheric conditions, Martian surface properties, and observation geometry.

CD4(+) T-cell survival in the GI tract requires dectin-1 during fungal infection.

Dectin-1 is an innate antifungal C-type lectin receptor necessary for protective antifungal immunity. We recently discovered that Dectin-1 is involved in controlling fungal infections of the gastrointestinal (GI) tract, but how this C-type lectin receptor mediates these activities is unknown. Here, we show that Dectin-1 is essential for driving fungal-specific CD4(+) T-cell responses in the GI tract. Loss of Dectin-1 resulted in abrogated dendritic cell responses in the mesenteric lymph nodes (mLNs) and defective T-cell co-stimulation, causing substantial increases in CD4(+) T-cell apoptosis and reductions in the cellularity of GI-associated lymphoid tissues. CD8(+) T-cell responses were unaffected by Dectin-1 deficiency. These functions of Dectin-1 have significant implications for our understanding of intestinal immunity and susceptibility to fungal infections.

Inactivating mutations in GNA13 and RHOA in Burkitt's lymphoma and diffuse large B-cell lymphoma: a tumor suppressor function for the Gα13/RhoA axis in B cells.

G proteins and their cognate G protein-coupled receptors (GPCRs) function as critical signal transduction molecules that regulate cell survival, proliferation, motility and differentiation. The aberrant expression and/or function of these molecules have been linked to the growth, progression and metastasis of various cancers. As such, the analysis of mutations in the genes encoding GPCRs, G proteins and their downstream targets provides important clues regarding how these signaling cascades contribute to malignancy. Recent genome-wide sequencing efforts have unveiled the presence of frequent mutations in GNA13, the gene encoding the G protein Gα13, in Burkitt's lymphoma and diffuse large B-cell lymphoma (DLBCL). We found that mutations in the downstream target of Gα13, RhoA, are also present in Burkitt's lymphoma and DLBCL. By multiple complementary approaches, we now show that that these cancer-specific GNA13 and RHOA mutations are inhibitory in nature, and that the expression of wild-type Gα13 in B-cell lymphoma cells with mutant GNA13 has limited impact in vitro but results in a remarkable growth inhibition in vivo. Thus, although Gα13 and RhoA activity has previously been linked to cellular transformation and metastatic potential of epithelial cancers, our findings support a tumor suppressive role for Gα13 and RhoA in Burkitt's lymphoma and DLBCL.

Randomized, phase III study results of clobazam in Lennox-Gastaut syndrome.

OBJECTIVE: To evaluate efficacy and safety of clobazam, a 1,5-benzodiazepine, as adjunctive therapy for Lennox-Gastaut syndrome (LGS). METHODS: Patients aged 2-60 years were randomized to placebo or clobazam 0.25, 0.5, or 1.0 mg/kg/day. Study consisted of 4-week baseline, 3-week titration, and 12-week maintenance phases, followed by a 2- or 3-week taper or continuation in an open-label extension. Primary endpoint was percentage decrease in mean weekly drop seizure rates during maintenance vs baseline phases for modified intention-to-treat (mITT) population. Secondary outcomes included other seizure types, responder rates, and physicians' and caregivers' global assessments. RESULTS: A total of 305 patients were screened, 238 were randomized, and 217 composed the mITT population. Of patients enrolled after a protocol amendment, 125/157 (79.6%) completed. Average weekly drop seizure rates decreased 12.1% for placebo vs 41.2% (p = 0.0120), 49.4% (p = 0.0015), and 68.3% (p < 0.0001) for the clobazam 0.25-, 0.5-, and 1.0-mg/kg/day groups. Responder rates (≥50%) were 31.6% (placebo) vs 43.4% (p = 0.3383), 58.6% (p = 0.0159), and 77.6% (p < 0.0001) for clobazam 0.25-, 0.5-, and 1.0-mg/kg/day groups. Physicians' and caregivers' assessments indicated clobazam significantly improved symptoms. Somnolence, pyrexia, upper respiratory infections, and lethargy were the most frequent adverse events reported for clobazam. CONCLUSIONS: Clobazam significantly decreased weekly drop seizure rates in LGS. No new safety signals were identified. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that clobazam as adjunctive therapy is efficacious, in a dosage-dependent manner, in reducing mean weekly drop seizure rates of patients with LGS over 12 weeks.

Current practice in bowel preparation for colorectal surgery: a survey of the members of the Association of Coloproctology of GB & Ireland.

AIM: Recent meta-analyses have suggested that mechanical bowel preparation is not beneficial in patients undergoing colorectal resection. This study aimed to assess current surgical practice in the UK. METHOD: Three hundred and ninety-eight members of the Association of Coloproctology of GB & Ireland were invited to complete an online survey to ascertain their current practice for bowel preparation. RESULTS: One hundred and ninety-nine surgeons completed the survey, of whom 95 (48%) routinely performed laparoscopic resection. The proportions using full bowel preparation for open vs laparoscopic surgery were, respectively, 9.5%vs 16.8% for right hemicolectomy, 43.4%vs 40.2% for left hemicolectomy, 20.5%vs 22.5% for an abdominoperineal resection and 72.2%vs 63.6% for low anterior resection. Among the surgeons who participated, 13.6% changed their practice between doing the same procedure open and laparoscopically, 76% of surgeons routinely defunctioned a low anterior resection. Of these, 22% did not feel that full bowel preparation was necessary before formation of an ileostomy. CONCLUSION: The study demonstrates that a large proportion of patients still receive full bowel preparation despite recent advice to the contrary.

Identification and validation of reference genes for normalization of transcripts from virus-infected Arabidopsis thaliana.

Real-time quantitative polymerase chain reaction (qPCR) of complementary DNA is now a standard method for studies of gene expression. However, qPCR can identify genuine variation only when transcript quantities are accurately normalized to an appropriate reference. To identify the most reliable reference genes for transcript quantification by qPCR, we describe a systematic evaluation of candidate reference genes of Arabidopsis thaliana ecotype Columbia-0 (Col-0). Twelve genes were selected for transcript stability studies by qPCR of complementary DNA prepared from Arabidopsis leaf tissue infected with one of five plant viruses (Cauliflower mosaic virus, Tobacco mosaic virus, Tomato spotted wilt virus, Turnip mosaic virus, and Turnip yellow mosaic virus). The F-box family protein, elongation factor 1-α, sand family protein, and protodermal factor 2 gene transcripts showed the most stable accumulation, whereas a traditionally used reference gene, Actin8, showed the least stable accumulation as measured by the geNorm algorithm. The data furnish plant virologists with reference genes for normalization of qPCR-derived gene expression in virus-infected Arabidopsis and will be beneficial to the selection and design of primers targeting orthologous genes in other plant species.

What proportion of basic surgical trainees continue in a surgical career? A survey of the factors which are important in influencing career decisions.

INTRODUCTION: Since the launch of Modernising Medical Careers, trainees are selected for a run-through training programme in a single surgical specialty. The surgical training bodies are currently considering the recommendations of the Tooke report as they review the policy for selection into surgical training in the UK. There is little information available on the factors involved in career choices amongst surgical trainees and this study aimed to address this issue. METHOD: Trainees appointed to the Basic Surgical Training Programmes in the west and south-east of Scotland (1996-2006) were contacted by email and invited to participate in an online survey. RESULTS: Of 467 trainees identified, valid email addresses were available for 299 of which 191 (64%) responded to the survey. One hundred and forty-nine (78%) trainees were still working in surgery but 38 (20%) had moved to a non-surgical specialty and 4 (2%) had left the medical profession. Of those who had obtained a NTN at the time of the survey (n = 138), 62 (45%) had a NTN in the specialty they chose at the start of the BST but 34 (25%) had changed to a different surgical specialty and 42 (30%) had left surgery altogether. For those still working in surgery, enjoyment of the specialty was the most important factor affecting career choice. Achieving an acceptable work/life balance was the most significant factor influencing trainees who left surgery. CONCLUSION: The majority of trainees recruited to surgery at an early stage change specialty or leave surgery altogether. Both social and professional factors are important in career choices. The findings of this study support a period of core surgical training to provide flexibility prior to further training in a surgical specialty.

A new method for determining the transfer function of an acousto optical tunable filter.

The current study describes the determination of the transfer function of an Acousto Optical Tunable Filter from the in-flight solar observations of the SOIR instrument on board Venus Express. An approach is proposed in order to reconstruct the transfer function profile from the analysis of various solar lines. Moreover this technique allows the determination of the evolution of the transfer function as a function of the AOTF radio frequency.

The effect of protective headgear on head injuries and concussions in adolescent football (soccer) players.

OBJECTIVE: To examine the effects of protective headgear in adolescent football (soccer) players. DESIGN: Cross-sectional study. SETTING: Oakville Soccer Club, Oakville, Canada. PARTICIPANTS: Football players aged 12-17 years. INTERVENTION: A questionnaire examining the 2006 football season using self-reported symptoms. MAIN OUTCOME MEASURES: The number of concussions experienced during the current football season, the duration of symptoms, injuries to the head and face and any associated risk factors for these injuries. RESULTS: In the population studied, 47.8% had experienced symptoms of a concussion during the current football year. 26.9% of athletes who wore headgear (HG) and 52.8% of those who did not wear headgear (No-HG) had concussions. Approximately 4 out of 5 athletes in each group did not realize they had suffered a concussion. More than one concussion was experienced by 50.0% of the concussed HG athletes and 69.3% of the concussed No-HG group. 23.9% of all concussed players experienced symptoms for at least 1 day or longer. Variables that increased the risk of suffering a concussion during the 2006 football year included being female and not wearing headgear. Being female and not wearing football headgear increased the risk of suffering an abrasion, laceration or contusion on areas of the head covered by football headgear. CONCLUSION: Adolescent football players experience a significant number of concussions. Being female may increase the risk of suffering a concussion and injuries on the head and face, while the use of football headgear may decrease the risk of sustaining these injuries.

Cytokine upregulation of proteinase-activated-receptors 2 and 4 expression mediated by p38 MAP kinase and inhibitory kappa B kinase beta in human endothelial cells.

BACKGROUND AND PURPOSE: Up-regulation of proteinase-activated receptor-2 (PAR2) is a factor in a number of disease states and we have therefore examined the signalling pathways involved in the expression of the receptor. EXPERIMENTAL APPROACH: We investigated the effects of tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), trypsin and the PAR2 activating peptide, 2-furoyl(2f)-LIGKV-OH on both mRNA and functional expression of PAR2 in human umbilical vein endothelial cells (HUVECs). The effect of specific chemical inhibitors and dominant negative adenovirus constructs of the mitogen-activated protein kinase (MAPK) cascade and the nuclear factor kappa B (NF-kappaB) signalling pathway was assessed. Methods included semi-quantitative and quantitative RT-PCR, [(3)H]inositol phosphate (IP) accumulation and Ca(2+)-dependent fluorescence. KEY RESULTS: The above agonists induced both mRNA and functional expression of PAR2; PAR4 mRNA, but not that for PAR1 or PAR-3, also increased following TNFalpha treatment. Inhibition of p38 MAP kinase reduced PAR2 and PAR4 expression, whilst inhibition of MEK1/ERK/JNK was without effect. A similar dependency upon p38 MAP kinase was observed for the expression of PAR4. TNFalpha -induced enhancement of PAR2 stimulated [(3)H]-inositol phosphate accumulation (IP) and Ca(2+) signalling was abolished following SB203580 pre-treatment. Infection with adenovirus encoding dominant-negative IKKbeta (Ad.IKKbeta(+/-)) and to a lesser extent dominant-negative IKKalpha (Ad.IKKalpha(+/-)), substantially reduced both control and IL-1beta- induced expression of both PAR2 and PAR4 mRNA and enhancement of PAR2-stimulated IP accumulation and Ca(2+) mobilisation. CONCLUSIONS AND IMPLICATIONS: These data reveal for the first time the signalling events involved in the upregulation of both PAR2 and PAR4 during pro-inflammatory challenge.

Orthodontic status and treatment need of 12-year-old children in South Africa using the Dental Aesthetic Index.

OBJECTIVE: The aim of this study was to determine the prevalence and severity of malocclusion and orthodontic treatment needs in a sample of 12-year-old South African school children using the Dental Aesthetic Index (DAI), and to assess the relationship between malocclusion and certain socio-demographic variables. METHODOLOGY: The sample comprised 6142, 12-year-old children attending school in seven of the nine provinces of South Africa. For each subject the standard demographic information such as gender, population group, location type and employment status of the parents was collected, after which an intra-oral examination for occlusal status using the DAI was performed. Before the survey, the examiners were calibrated and trained and only examiners with an agreement score greater or equal to 80 per cent were included in the final study. RESULTS: The results showed that 47.7 per cent of the children in the sample presented with good occlusion or minor malocclusion, just over 52.3 per cent presented with identifiable malocclusion, a DAI score larger than 26. Of these, 21.2 per cent had definite malocclusion, 14.1 per cent had severe malocclusion and 16.9 per cent had very severe or handicapping malocclusion. Malocclusion as defined in this study was found to be significantly associated with the different population groups in South Africa, with gender and with dentition stage, but not with the location type or the employment status of parents. CONCLUSIONS: The results of this study show a high prevalence of malocclusion in 12-year-old South African children. The findings provide reliable base-line data regarding the prevalence, distribution and severity of malocclusion as well as useful epidemiological data on the orthodontic treatment needs of 12-year-old children in South Africa.

ISER: selection of differentially expressed genes from DNA array data by non-linear data transformations and local fitting.

SUMMARY: This report describes an algorithm (intensity-dependent selection of expression ratios or ISER) developed to analyse DNA array data by optimizing the selection of genes with the most significant variations in expression amongst two RNA samples. The algorithm is designed for use when little or no replication of array hybridizations is available.

Changes in practice of breast cancer radiotherapy 1998-2002: an Australasian survey.

In order to assess the impact on radiation oncology practice of the publication of evidence-based guidelines for technical aspects of therapeutic radiation for breast cancer, the Radiation Oncology Expert Advisory Group of the National Breast Cancer Centre conducted two postal surveys of radiation oncologists practising in Australia and New Zealand. Results from a survey conducted in 1998, prior to distribution of the guidelines, have been published previously. This article reports on results from a survey undertaken in 2002 and contains data from 102 respondents who manage women with breast cancer. The results show several important changes in practice since 1998, including increased use of CT scanning in breast cancer treatment planning and increased use of immobilization devices for patient treatment. There is also evidence of increased attention to technical aspects of treatment planning that reduce the potential risk of treatment toxicity. The influence of the guidelines, the wider availability of modern equipment and results from landmark clinical trials on change in radiation therapy practice is discussed.