A systematic review of the impact of postoperative aerobic exercise training in patients undergoing surgery for intra-abdominal cancers

INTRODUCTION

Enhanced recovery after surgery (ERAS) programmes which advocate early mobility after surgery have improved immediate clinical outcomes for patients undergoing abdominal cancer resections with curative intent. However, the impact of continued physical activity on patient-related outcomes and functional recovery is not well defined. The aim of this review was to assess the impact of postoperative aerobic exercise training, either alone or in conjunction with another exercise modality, on patients who have had surgery for intra-abdominal cancer.

METHODS

A literature search was performed of electronic journal databases. Eligible papers needed to report an outcome of aerobic capacity in patients older than 18 years of age, who underwent cancer surgery with curative intent and participated in an exercise programme (not solely ERAS) that included an aerobic exercise component starting at any point in the postoperative pathway up to 12 weeks.

RESULTS

Eleven studies were deemed eligible for inclusion consisting of two inpatient, one mixed inpatient/outpatient and eight outpatient studies. Meta-analysis of four outpatient studies, each reporting change in 6-min walk test (6MWT), showed a significant improvement in 6MWT with exercise (MD 74.92 m, 95% CI 48.52-101.31 m). The impact on health-related quality of life was variable across studies.

CONCLUSION

Postoperative exercise confers benefits in improving aerobic function post surgery and can be safely delivered in various formats (home-based or group/supervised).

Evaluation of acquisition modes for semi-quantitative analysis by targeted and untargeted mass spectrometry

RATIONALE

Analyte quantitation by mass spectrometry underpins a diverse range of scientific endeavors. The fast-growing field of mass spectrometer development has resulted in several targeted and untargeted acquisition modes suitable for these applications. By characterizing the acquisition methods available on an ion mobility (IM)-enabled orthogonal acceleration time-of-flight (oa-ToF) instrument, the optimum modes for analyte semi-quantitation can be deduced.

METHODS

Serial dilutions of commercial metabolite, peptide, or cross-linked peptide analytes were prepared in matrices of human urine or Escherichia coli digest. Each analyte dilution was introduced into an IM separation-enabled oa-ToF mass spectrometer by reversed-phase liquid chromatography and electrospray ionization. Data were acquired for each sample in duplicate using nine different acquisition modes, including four IM-enabled acquisitions modes, available on the mass spectrometer.

RESULTS

Five (metabolite) or seven (peptide/cross-linked peptide) point calibration curves were prepared for analytes across each of the acquisition modes. A nonlinear response was observed at high concentrations for some modes, attributed to saturation effects. Two correction methods, one MS1 isotope-correction and one MS2 ion intensity-correction, were applied to address this observation, resulting in an up to twofold increase in dynamic range. By averaging the semi-quantitative results across analyte classes, two parameters, linear dynamic range (LDR) and lower limit of quantification (LLOQ), were determined to evaluate each mode.

CONCLUSION

A comparison of the acquisition modes revealed that data-independent acquisition and parallel reaction monitoring methods are most robust for semi-quantitation when considering achievable LDR and LLOQ. IM-enabled modes exhibited sensitivity increases, but a simultaneous reduction in dynamic range required correction methods to recover. These findings will assist users in identifying the optimum acquisition mode for their analyte quantitation needs, supporting a diverse range of applications and providing guidance for future acquisition mode developments.

What's Race Got to Do With It? CRP Levels in Immune Mediated Skin Diseases: Considerations for Hidradenitis Suppurativa

Currently, there is a lack of racial/ethnic heterogeneity in research databases, exposing a systematic issue in studies exploring inflammation-mediated diseases, such as hidradenitis suppurativa (HS). HS is a chronic inflammatory skin condition that disrupts normal structure and functioning of terminal hair follicles, resulting in the formation of recurrent abscesses, nodules, and sinus tracts within intertriginous regions. Studies have described higher serum levels of inflammation-mediated C-reactive protein (CRP) in patients with HS, a disease that predominantly affects skin of color (SOC) populations. Herein, we explore the role of CRP levels in the context of HS disease presentation, management, and psychosocial implications in SOC patients to determine existing disparities in research studies.

Long-acting PGE2 and Lisinopril Mitigate H-ARS

Thrombocytopenia is a major complication in hematopoietic-acute radiation syndrome (H-ARS) that increases the risk of mortality from uncontrolled hemorrhage. There is a great demand for new therapies to improve survival and mitigate bleeding in H-ARS. Thrombopoiesis requires interactions between megakaryocytes (MKs) and endothelial cells. 16, 16-dimethyl prostaglandin E2 (dmPGE2), a longer-acting analogue of PGE2, promotes hematopoietic recovery after total-body irradiation (TBI), and various angiotensin-converting enzyme (ACE) inhibitors mitigate endothelial injury after radiation exposure. Here, we tested a combination therapy of dmPGE2 and lisinopril to mitigate thrombocytopenia in murine models of H-ARS following TBI. After 7.75 Gy TBI, dmPGE2 and lisinopril each increased survival relative to vehicle controls. Importantly, combined dmPGE2 and lisinopril therapy enhanced survival greater than either individual agent. Studies performed after 4 Gy TBI revealed reduced numbers of marrow MKs and circulating platelets. In addition, sublethal TBI induced abnormalities both in MK maturation and in in vitro and in vivo platelet function. dmPGE2, alone and in combination with lisinopril, improved recovery of marrow MKs and peripheral platelets. Finally, sublethal TBI transiently reduced the number of marrow Lin-CD45-CD31+Sca-1- sinusoidal endothelial cells, while combined dmPGE2 and lisinopril treatment, but not single-agent treatment, accelerated their recovery. Taken together, these data support the concept that combined dmPGE2 and lisinopril therapy improves thrombocytopenia and survival by promoting recovery of the MK lineage, as well as the MK niche, in the setting of H-ARS.

Delay in Source Control in Perforated Peptic Ulcer Leads to 6% Increased Risk of Death Per Hour: A Nationwide Cohort Study

BACKGROUND

Delay to theatre for patients with intra-abdominal sepsis is cited as a particular risk factor for death. Our aim was to evaluate the potential relationship between hourly delay from admission to surgery and post-operative mortality in patients with perforated peptic ulcer (PPU).

METHODS

All patients entered in the National Emergency Laparotomy Audit who had an emergency laparotomy for PPU within 24 h of admission from December 2013 to November 2017 were included. Time to theatre from admission was modelled as a continuous variable in hours. Outcome was 90-day mortality. Logistic regression adjusting for confounding factors was performed.

RESULTS

3809 patients were included, and 90-day mortality rate was 10.61%. Median time to theatre was 7.5 h (IQR 5-11.6 h). The odds of death increased with time to operation once adjustment for confounding variables was performed (per hour after admission adjusted OR 1.04 95% CI 1.02-1.07). In patients who were physiologically shocked (N = 334), there was an increase of 6% in risk-adjusted odds of mortality for every hour Em Lap was delayed after admission (OR 1.06 95% CI 1.01-1.11).

CONCLUSION

Hourly delay to theatre in patients with PPU is independently associated with risk of death by 90 days. Therefore, we suggest that surgical source control should occur as soon as possible after admission regardless of time of day.

Trainee-led emergency laparotomy operating

Background

To achieve completion of training in general surgery, trainees are required to demonstrate competency in common procedures performed at emergency laparotomy. The aim of this study was to describe the patterns of trainee-led emergency laparotomy operating and the association between postoperative outcomes.

Methods

Data on all patients who had an emergency laparotomy between December 2013 and November 2017 were extracted from the National Emergency Laparotomy Audit database. Patients were grouped by grade of operating surgeon: trainee (specialty registrar) or consultant (including post-Certificate of Completion of Training fellows). Trends in trainee operating by deanery, hospital size and time of day of surgery were investigated. Univariable and adjusted regression analyses were performed for the outcomes 90-day mortality and return to theatre, with analysis of patients in operative subgroups segmental colectomy, Hartmann's procedure, adhesiolysis and repair of perforated peptic ulcer disease.

Results

The study cohort included 87 367 patients. The 90-day mortality rate was 15·1 per cent in the consultant group compared with 11·0 per cent in the trainee group. There were no increased odds of death by 90 days or of return to theatre across any of the operative groups when the operation was performed with a trainee listed as the most senior surgeon in theatre. Trainees were more likely to operate independently in high-volume centres (highest- versus lowest-volume centres: odds ratio (OR) 2·11, 95 per cent c.i. 1·91 to 2·33) and at night (00.00 to 07.59 versus 08.00 to 11.59 hours; OR 3·20, 2·95 to 3·48).

Conclusion

There is significant variation in trainee-led operating in emergency laparotomy by geographical area, hospital size and by time of day. However, this does not appear to influence mortality or return to theatre.

Top-Down Characterization of Denatured Proteins and Native Protein Complexes Using Electron Capture Dissociation Implemented within a Modified Ion Mobility-Mass Spectrometer

Electron-based fragmentation methods have revolutionized biomolecular mass spectrometry, in particular native and top-down protein analysis. Here, we report the use of a new electromagnetostatic cell to perform electron capture dissociation (ECD) within a quadrupole/ion mobility/time-of-flight mass spectrometer. This cell was installed between the ion mobility and time-of-flight regions of the instrument, and fragmentation was fast enough to be compatible with mobility separation. The instrument was already fitted with electron transfer dissociation (ETD) between the quadrupole and mobility regions prior to modification. We show excellent fragmentation efficiency for denatured peptides and proteins without the need to trap ions in the gas phase. Additionally, we demonstrate native top-down backbone fragmentation of noncovalent protein complexes, leading to comparable sequence coverage to what was achieved using the instrument's existing ETD capabilities. Limited collisional ion activation of the hemoglobin tetramer before ECD was reflected in the observed fragmentation pattern, and complementary ion mobility measurements prior to ECD provided orthogonal evidence of monomer unfolding within this complex. The approach demonstrated here provides a powerful platform for both top-down proteomics and mass spectrometry-based structural biology studies.

Long-term outcomes of biological mesh repair following extra levator abdominoperineal excision of the rectum: an observational study of 100 patients

Background

Current evidence suggests that pelvic floor reconstruction following extralevator abdominoperineal excision of rectum (ELAPER) may reduce the risk of perineal herniation of intra-abdominal contents. Options for reconstruction include mesh and myocutaneous flaps, for which long-term follow-up data is lacking. The aim of this study was to evaluate the long-term outcomes of biological mesh (Surgisis^®, Biodesign™) reconstruction following ELAPER.

Methods

A retrospective review of all patients having ELAPER in a single institution between 2008 and 2018 was perfomed. Clinic letters were scrutinised for wound complications and all available cross sectional imaging was reviewed to identify evidence of perineal herniation (defined as presence of intra-abdominal content below a line between the coccyx and the lower margin of the pubic symphysis on sagittal view).

Results

One hundred patients were identified (median age 66, IQR 59–72 years, 70% male). Median length of follow-up was 4.9 years (IQR 2.3–6.7 years). One, 2- and 5-year mortality rates were 3, 8 and 12%, respectively. Thirty three perineal wounds had not healed by 1 month, but no mesh was infected and no mesh needed to be removed. Only one patient developed a symptomatic perineal hernia requiring repair. On review of imaging a further 7 asymptomatic perineal hernias were detected. At 4 years the cumulative radiologically detected perineal hernia rate was 8%.

Conclusions

This study demonstrates that pelvic floor reconstruction using biological mesh following ELAPER is both safe and effective as a long-term solution, with low major complication rates. Symptomatic perineal herniation is rare following mesh reconstruction, but may develop sub clinically and be detectable on cross-sectional imaging.

Aquaporin-4 and MOG autoantibody discovery in idiopathic transverse myelitis epidemiology

OBJECTIVE

Diagnostic criteria from 2002 classify transverse myelitis (TM) as idiopathic or disease associated but predate the discovery of aquaporin-4 (AQP4)-immunoglobulin G (IgG) and myelin oligodendrocyte glycoprotein (MOG)-IgG, which associate with TM. Prior incidence estimates of idiopathic TM (ITM) range from 1 to 6.2 per 1 million. We sought to determine whether the population-based incidence and prevalence of ITM were reduced by testing patients with ITM for AQP4/MOG-IgG and reclassifying seropositive cases as having disease-associated TM.

METHODS

For this observational study, we retrospectively identified all cases of incident (January 1, 2003-December 31, 2016) and prevalent (December 31, 2016) ITM in Olmsted County (85% white) by using the Rochester Epidemiology Project medical records linkage system. ITM was defined by the 2002 Transverse MyelitisConsortium Working Group diagnostic criteria. Available sera were tested for AQP4-IgG and MOG-IgG.

RESULTS

Twenty-four patients (incident 22, prevalent 17) initially met 2002 ITM criteria (longitudinally extensive TM [LETM] 6). Sera were tested for AQP4-IgG in 22 of 24 (92%) and MOG-IgG in 21 of 24 (88%). Three seropositive cases (AQP4-IgG 2, MOG-IgG 1) were identified and reclassified as having disease-associated TM, accounting for 14% of total incident and 12% of total prevalent cases. AQP4-IgG and MOG-IgG seropositive cases represented 50% (3 of 6) of idiopathic LETM. After reclassification of seropositive patients, the final ITM incidence was 8.6 per 1,000,000 and prevalence was 7.9 per 100,000. Three cases of ITM (14%) subsequently fulfilled multiple sclerosis criteria within the study period.

CONCLUSIONS

The availability of AQP4-IgG and MOG-IgG modestly reduced ITM incidence and prevalence, which remained higher than previously reported in this predominantly white population. Incorporation of these biomarkers into future revisions of TM diagnostic criteria should be considered.

Association between surgeon special interest and mortality after emergency laparotomy

Background

Approximately 30 000 emergency laparotomies are performed each year in England and Wales. Patients with pathology of the gastrointestinal tract requiring emergency laparotomy are managed by general surgeons with an elective special interest focused on either the upper or lower gastrointestinal tract. This study investigated the impact of special interest on mortality after emergency laparotomy.

Methods

Adult patients having emergency laparotomy with either colorectal or gastroduodenal pathology were identified from the National Emergency Laparotomy Audit database and grouped according to operative procedure. Outcomes included all-cause 30-day mortality, length of hospital stay and return to theatre. Logistic and Poisson regression were used to analyse the association between consultant special interest and the three outcomes.

Results

A total of 33 819 patients (28 546 colorectal, 5273 upper gastrointestinal (UGI)) were included. Patients who had colorectal procedures performed by a consultant without a special interest in colorectal surgery had an increased adjusted 30-day mortality risk (odds ratio (OR) 1·23, 95 per cent c.i. 1·13 to 1·33). Return to theatre also increased in this group (OR 1·13, 1·05 to 1·20). UGI procedures performed by non-UGI special interest surgeons carried an increased adjusted risk of 30-day mortality (OR 1·24, 1·02 to 1·53). The risk of return to theatre was not increased (OR 0·89, 0·70 to 1·12).

Conclusion

Emergency laparotomy performed by a surgeon whose special interest is not in the area of the pathology carries an increased risk of death at 30 days. This finding potentially has significant implications for emergency service configuration, training and workforce provision, and should stimulate discussion among all stakeholders.

Reliability of frailty assessment in the critically ill: a multicentre prospective observational study

Demand for critical care among older patients is increasing in many countries. Assessment of frailty may inform discussions and decision making, but acute illness and reliance on proxies for history-taking pose particular challenges in patients who are critically ill. Our aim was to investigate the inter-rater reliability of the Clinical Frailty Scale for assessing frailty in patients admitted to critical care. We conducted a prospective, multi-centre study comparing assessments of frailty by staff from medical, nursing and physiotherapy backgrounds. Each assessment was made independently by two assessors after review of clinical notes and interview with an individual who maintained close contact with the patient. Frailty was defined as a Clinical Frailty Scale rating > 4. We made 202 assessments in 101 patients (median (IQR [range]) age 69 (65-75 [60-80]) years, median (IQR [range]) Acute Physiology and Chronic Health Evaluation II score 19 (15-23 [7-33])). Fifty-two (51%) of the included patients were able to participate in the interview; 35 patients (35%) were considered frail. Linear weighted kappa was 0.74 (95%CI 0.67-0.80) indicating a good level of agreement between assessors. However, frailty rating differed by at least one category in 47 (47%) cases. Factors independently associated with higher frailty ratings were: female sex; higher Acute Physiology and Chronic Health Evaluation II score; higher category of pre-hospital dependence; and the assessor having a medical background. We identified a good level of agreement in frailty assessment using the Clinical Frailty Scale, supporting its use in clinical care, but identified factors independently associated with higher ratings which could indicate personal bias.

Impact of the calcium form of β-hydroxy-β-methylbutyrate upon human skeletal muscle protein metabolism

BACKGROUND & AIMS

β-hydroxy-β-methylbutyrate (HMB) is purported as a key nutritional supplement for the preservation of muscle mass in health, disease and as an ergogenic aid in exercise. Of the two available forms of HMB (calcium (Ca-HMB) salt or free acid (FA-HMB)) - differences in plasma bioavailability have been reported. We previously reported that ∼3 g oral FA-HMB increased muscle protein synthesis (MPS) and reduced muscle protein breakdown (MPB). The objective of the present study was to quantify muscle protein metabolism responses to oral Ca-HMB.

METHODS

Eight healthy young males received a primed constant infusion of 1,2 ¹³C₂ leucine and ²H₅ phenylalanine to assess MPS (by tracer incorporation in myofibrils) and MPB (via arterio-venous (A-V) dilution) at baseline and following provision of ∼3 g of Ca-HMB; muscle anabolic (MPS) and catabolic (MPB) signalling was assessed via immunoblotting.

RESULTS

Ca-HMB led a significant and rapid (<60 min) peak in plasma HMB concentrations (483.6 ± 14.2 μM, p < 0.0001). This rise in plasma HMB was accompanied by increases in MPS (PA: 0.046 ± 0.004%/h, CaHMB: 0.072 ± 0.004%/h, p < 0001) and suppressions in MPB (PA: 7.6 ± 1.2 μmol Phe per leg min^-1, Ca-HMB: 5.2 ± 0.8 μmol Phe per leg min^-1, p < 0.01). Increases in the phosphorylation of mTORc1 substrates i.e. p70S6K1 and RPS6 were also observed, with no changes detected in the MPB targets measured.

CONCLUSIONS

These findings support the pro-anabolic properties of HMB via mTORc1, and show that despite proposed differences in bioavailability, Ca-HMB provides a comparable stimulation to MPS and suppression of MPB, to FA-HMB, further supporting its use as a pharmaconutrient in the modulation of muscle mass.

Size, growth, and density data for shallow-water sea urchins from Mexico to the Aleutian Islands, Alaska, 1956-2016

Size, growth, and density have been studied for North American Pacific coast sea urchins Strongylocentrotus purpuratus, S. droebachiensis, S. polyacanthus, Mesocentrotus (Strongylocentrotus) franciscanus, Lytechinus pictus, Centrostephanus coronatus, and Arbacia stellata by various workers at diverse sites and for varying lengths of time from 1956 to present. Numerous peer-reviewed publications have used some of these data but some data have appeared only in graduate theses or the gray literature. There also are data that have never appeared outside original data sheets. Motivation for studies has included fisheries management and environmental monitoring of sewer and power plant outfalls as well as changes associated with disease epidemics. Studies also have focused on kelp restoration, community effects of sea otters, basic sea urchin biology, and monitoring. The data sets presented here are a historical record of size, density, and growth for a common group of marine invertebrates in intertidal and nearshore environments that can be used to test hypotheses concerning future changes associated with fisheries practices, shifts of predator distributions, climate and ecosystem changes, and ocean acidification along the Pacific Coast of North America and islands of the north Pacific. No copyright restrictions apply. Please credit this paper when using the data.

Simulation fails to replicate stress in trainees performing a technical procedure in the clinical environment

INTRODUCTION

Simulation-based training (SBT) has become an increasingly important method by which doctors learn. Stress has an impact upon learning, performance, technical, and non-technical skills. However, there are currently no studies that compare stress in the clinical and simulated environment. We aimed to compare objective (heart rate variability, HRV) and subjective (state trait anxiety inventory, STAI) measures of stress theatre with a simulated environment.

METHODS

HRV recordings were obtained from eight anesthetic trainees performing an uncomplicated rapid sequence induction at pre-determined procedural steps using a wireless Polar RS800CX monitor © in an emergency theatre setting. This was repeated in the simulated environment. Participants completed an STAI before and after the procedure.

RESULTS

Eight trainees completed the study. The theatre environment caused an increase in objective stress vs baseline (p = .004). There was no significant difference between average objective stress levels across all time points (p = .20) between environments. However, there was a significant interaction between the variables of objective stress and environment (p = .045). There was no significant difference in subjective stress (p = .27) between environments.

DISCUSSION

Simulation was unable to accurately replicate the stress of the technical procedure. This is the first study that compares the stress during SBT with the theatre environment and has implications for the assessment of simulated environments for use in examinations, rating of technical and non-technical skills, and stress management training.

EGFR-Stat3 signalling in nerve glial cells modifies neurofibroma initiation

Neurofibromatosis type 1 (NF1) is an inherited disease in which affected patients are predisposed to develop benign Schwann cell (SC) tumours called neurofibromas. In the mouse, loss of Nf1 in the SC lineage causes neurofibroma formation. The tyrosine kinase receptor EGFR is expressed in Schwann cell precursors (SCP), which have been implicated in plexiform neurofibroma initiation. To test if EGFR activity affects neurofibroma initiation, size, and/or number, we studied mice expressing human EGFR in SCs and SCP in the context of mice that form neurofibromas. Neurofibroma number increased in homozygous CNP-hEGFR mice versus heterozygous littermates, and neurofibroma number and size increased when CNP-hEGFR was crossed to Nf1^fl/fl;DhhCre mice. Conversely, diminished EGFR signalling in Nf1^fl/fl;DhhCre;Wa2/+ mice decreased neurofibroma number. In vivo transplantation verified the correlation between EGFR activity and neurofibroma formation. Mechanistically, expression of CNP-hEGFR increased SCP/neurofibroma-initiating cell self-renewal, a surrogate for tumour initiation, and activated P-Stat3. Further, Il-6 reinforced Jak2/Stat3 activation in SCPs and SCs. These gain- and loss-of function assays show that levels of tyrosine kinase expression in SCPs modify neurofibroma initiation.

A 31-day time to surgery compliant exercise training programme improves aerobic health in the elderly

BACKGROUND

Over 41,000 people were diagnosed with colorectal cancer (CRC) in the UK in 2011. The incidence of CRC increases with age. Many elderly patients undergo surgery for CRC, the only curative treatment. Such patients are exposed to risks, which increase with age and reduced physical fitness. Endurance-based exercise training programmes can improve physical fitness, but such programmes do not comply with the UK, National Cancer Action Team 31-day time-to-treatment target. High-intensity interval training (HIT) can improve physical performance within 2-4 weeks, but few studies have shown HIT to be effective in elderly individuals, and those who do employ programmes longer than 31 days. Therefore, we investigated whether HIT could improve cardiorespiratory fitness in elderly volunteers, age-matched to a CRC population, within 31 days.

METHODS

This observational cohort study recruited 21 healthy elderly participants (8 male and 13 female; age 67 years (range 62-73 years)) who undertook cardiopulmonary exercise testing before and after completing 12 sessions of HIT within a 31-day period.

RESULTS

Peak oxygen consumption (VO2 peak) (23.9 ± 4.7 vs. 26.2 ± 5.4 ml/kg/min, p = 0.0014) and oxygen consumption at anaerobic threshold (17.86 ± 4.45 vs. 20.21 ± 4.11 ml/kg/min, p = 0.008) increased after HIT.

CONCLUSIONS

It is possible to improve cardiorespiratory fitness in 31 days in individuals of comparable age to those presenting for CRC surgery.

Combining density functional theory (DFT) and collision cross-section (CCS) calculations to analyze the gas-phase behaviour of small molecules and their protonation site isomers

Computational methods are employed to study the protomers in ESI-IM-MS.

Systematic review of pre-operative exercise in colorectal cancer patients

The aim of this systematic review was to evaluate the evidence for exercise interventions prior to surgery for colorectal cancer resection. The evidence for use of exercise to improve physical fitness and surgical outcomes is as yet unknown. A systematic search was performed of MEDLINE, EMBASE, CINAHL, AMED and BNI databases for studies involving pre-operative exercise in colorectal cancer patients. Eight studies were included in the review. There is evidence that pre-operative exercise improves functional fitness, and to a lesser extent objectively measurable cardio-respiratory fitness prior to colorectal cancer resection. There is no clear evidence at present that this improvement in fitness translates into reduced peri-operative risk or improved post-operative outcomes. Current studies are limited by risk of bias. This review highlights the common difficulty in transferring promising results in a research setting, into significant improvements in the clinical arena. Future research should focus on which type of exercise is most likely to maximise patient adherence and improvements in cardio-respiratory fitness. Ultimately, adequately powered, randomised controlled trials are needed to investigate whether pre-operative exercise improves post-operative morbidity and mortality.

Day-case closure of ileostomy: feasible, safe and efficient

AIM

Over 5000 loop ileostomy closures were performed in the UK in 2013 with a median inpatient stay of 5 days. Previously we have successfully implemented a 23-h protocol for loop ileostomy closure which was modified for same-day discharge. We present our early experience of day-case loop ileostomy closure.

METHOD

A specific patient pathway for day-case discharge following loop ileostomy closure was implemented with inclusion criteria to conform with British Association of Day Surgery guidelines. Exclusion criteria included postoperative chemoradiotherapy, multiple comorbidities and social care needs. Follow-up consisted of telephone contact (24 and 72 h after discharge) and a routine outpatient appointment. Patients were provided with a 24-h contact point in case of emergency.

RESULTS

Fifteen (12 male) patients were enrolled of median age 67 (39-80) years. The median operating time was 41 (23-80) min. The indication for ileostomy formation was to cover a low anterior resection for adenocarcinoma (13), reversal of Hartmann's procedure (1) and functional bowel disorder (1). The median interval from the primary procedure to day-case loop ileostomy closure was 8 (3-14) months. Every patient was discharged on the day of surgery. There were no complications related to the surgery and there was one readmission due to a urinary tract infection. The median length of follow-up was 4 (2-16) months.

CONCLUSION

Our early experience shows that day-case loop ileostomy closure is feasible, safe and efficient. This protocol will become standard within our institution for suitable patients, saving on average five inpatient bed days per patient.

Ionizing radiation induces myofibroblast differentiation via lactate dehydrogenase

Pulmonary fibrosis is a common and dose-limiting side-effect of ionizing radiation used to treat cancers of the thoracic region. Few effective therapies are available for this disease. Pulmonary fibrosis is characterized by an accumulation of myofibroblasts and excess deposition of extracellular matrix proteins. Although prior studies have reported that ionizing radiation induces fibroblast to myofibroblast differentiation and collagen production, the mechanism remains unclear. Transforming growth factor-β (TGF-β) is a key profibrotic cytokine that drives myofibroblast differentiation and extracellular matrix production. However, its activation and precise role in radiation-induced fibrosis are poorly understood. Recently, we reported that lactate activates latent TGF-β through a pH-dependent mechanism. Here, we wanted to test the hypothesis that ionizing radiation leads to excessive lactate production via expression of the enzyme lactate dehydrogenase-A (LDHA) to promote myofibroblast differentiation. We found that LDHA expression is increased in human and animal lung tissue exposed to ionizing radiation. We demonstrate that ionizing radiation induces LDHA, lactate production, and extracellular acidification in primary human lung fibroblasts in a dose-dependent manner. We also demonstrate that genetic and pharmacologic inhibition of LDHA protects against radiation-induced myofibroblast differentiation. Furthermore, LDHA inhibition protects from radiation-induced activation of TGF-β. We propose a profibrotic feed forward loop, in which radiation induces LDHA expression and lactate production, which can lead to further activation of TGF-β to drive the fibrotic process. These studies support the concept of LDHA as an important therapeutic target in radiation-induced pulmonary fibrosis.

Extensive Charge Reduction and Dissociation of Intact Protein Complexes Following Electron Transfer on a Quadrupole-Ion Mobility-Time-of-Flight MS

Non-dissociative charge reduction, typically considered to be an unwanted side reaction in electron transfer dissociation (ETD) experiments, can be enhanced significantly in order to reduce the charge state of intact protein complexes to as low as 1+ on a commercially available Q-IM-TOF instrument. This allows for the detection of large complexes beyond 100,000 m/z, while at the same time generating top-down ETD fragments, which provide sequence information from surface-exposed parts of the folded structure. Optimization of the supplemental activation has proven to be crucial in these experiments and the charge-reduced species are most likely the product of both proton transfer (PTR) and non-dissociative electron transfer (ETnoD) reactions that occur prior to the ion mobility cell. Applications of this approach range from deconvolution of complex spectra to the manipulation of charge states of gas-phase ions.

Assessing surgeon stress when operating using heart rate variability and the State Trait Anxiety Inventory: will surgery be the death of us?

AIM

Performance in the operating room is affected by a combination of individual, patient and environmental factors amongst others. Stress has a potential negative impact on performance with the quality of surgical practice and patient safety being affected as a result. In order to appreciate the level of stress encountered during surgical procedures both objective and subjective methods can be used. This study reports the use of a combined objective (physiological) and subjective (psychological) method for evaluating stress experienced by the operating surgeon.

METHOD

Six consultant colorectal surgeons were evaluated performing eighteen anterior resections. Heart rate was recorded using a wireless chest strap at eight pre-determined operative steps. Heart Rate Variability indices were calculated offline using computerized software. Surgeon reported stress was collected using the State Trait Anxiety Inventory, a validated clinical stress scale.

RESULTS

A significant increase in stress was demonstrated in all surgeons whilst operating as indicated by sympathetic tone (control: 4.02 ± 2.28 vs operative: 11.42 ± 4.63; P < 0.0001). Peaks in stress according to operative step were comparable across procedures and surgeons. There was a significant positive correlation with subjective reporting of stress across procedures (r = 0.766; P = 0.0005).

CONCLUSION

This study demonstrates a significant increase in sympathetic tone in consultant surgeons measured using heart rate variability during elective colorectal resections. A significant correlation can be demonstrated between HRV measurements and perceived stress using the State Trait Anxiety Inventory. A combined approach to assessing operative stress is required to evaluate any effect on performance and outcomes.

Ion mobility-derived collision cross section as an additional measure for lipid fingerprinting and identification

Despite recent advances in analytical and computational chemistry, lipid identification remains a significant challenge in lipidomics. Ion-mobility spectrometry provides an accurate measure of the molecules' rotationally averaged collision cross-section (CCS) in the gas phase and is thus related to ionic shape. Here, we investigate the use of CCS as a highly specific molecular descriptor for identifying lipids in biological samples. Using traveling wave ion mobility mass spectrometry (MS), we measured the CCS values of over 200 lipids within multiple chemical classes. CCS values derived from ion mobility were not affected by instrument settings or chromatographic conditions, and they were highly reproducible on instruments located in independent laboratories (interlaboratory RSD < 3% for 98% of molecules). CCS values were used as additional molecular descriptors to identify brain lipids using a variety of traditional lipidomic approaches. The addition of CCS improved the reproducibility of analysis in a liquid chromatography-MS workflow and maximized the separation of isobaric species and the signal-to-noise ratio in direct-MS analyses (e.g., "shotgun" lipidomics and MS imaging). These results indicate that adding CCS to databases and lipidomics workflows increases the specificity and selectivity of analysis, thus improving the confidence in lipid identification compared to traditional analytical approaches. The CCS/accurate-mass database described here is made publicly available.

Simple psoas cross-sectional area measurement is a quick and easy method to assess sarcopenia and predicts major surgical complications

AIM

Radiologically assessed muscle mass has been suggested as a surrogate marker of functional status and frailty and may predict patients at risk of postoperative complications. We hypothesize that sarcopenia negatively impacts on postoperative recovery and is predictive of complications.

METHOD

One hundred patients undergoing elective resection for colorectal carcinoma were included in this study. Lean muscle mass was estimated by measuring the cross-sectional area of the psoas muscle at the level of the third lumbar vertebra identified on a preoperative CT scan, normalizing for patient height. Perioperative morbidity was scored according to the Clavien-Dindo classification. All statistical data analyses were carried out using the Statistical Package for the Social Sciences (SPSS) version 20.0.

RESULTS

Fifteen per cent of patients were identified as sarcopenic. There were no deaths in the study group. Sarcopenia was associated with a significantly increased risk of developing major complications (Grade 3 or greater, OR = 5.41, 95% CI: 1.45-20.15, P = 0.01). Sarcopenia did not predict length of stay, critical care dependency or time to mobilization.

CONCLUSION

Sarcopenia, as a marker of frailty, is an important risk factor in surgical patients but difficult to estimate using bedside testing. CT scans, performed for preoperative staging, provide an opportunity to quantify lean muscle mass without additional cost or exposure to radiation and eliminate the inconvenience of further investigations.

Comparison of magnetic resonance urography to dimercaptosuccinic acid scan for the identification of renal parenchyma defects in children with vesicoureteral reflux

OBJECTIVE

The objective of this study was to compare the accuracy of dimercaptosuccinic acid (DMSA) renal scan to magnetic resonance urography (MRU) in the identification of renal parenchyma defects (RPD).

MATERIALS AND METHODS

Twenty-five children with history of acute pyelonephritis and vesicoureteral reflux underwent DMSA scan and MRU to determine the presence of RPD. DMSA scans and MRUs were each evaluated by two radiologists and agreement achieved by consensus. Discordant DMSA-MRU findings were re-evaluated in a side-by-side comparison and an ultimate consensus reached.

RESULTS

The ultimate consensus diagnosis was 18 kidneys with RPDs in 15 patients, of which five were classified as mild RPDs, six as moderate RPDs, and seven as severe RPDs. Although DMSA scan and MRU were similar in their ability to diagnose RPDs, MRU was considered to represent the true diagnosis in 11 of the 12 discordant cases in consensus review by four pediatric radiologists. MRU showed a much higher inter-observer agreement with a weighted kappa of 0.96 for both kidneys compared to 0.71 for the right kidney and 0.86 for the left kidney by DMSA scan.

CONCLUSIONS

Our results suggest that MRU is superior to DMSA scan in the identification of renal parenchyma defects.

Ion mobility derived collision cross sections to support metabolomics applications

Metabolomics is a rapidly evolving analytical approach in life and health sciences. The structural elucidation of the metabolites of interest remains a major analytical challenge in the metabolomics workflow. Here, we investigate the use of ion mobility as a tool to aid metabolite identification. Ion mobility allows for the measurement of the rotationally averaged collision cross-section (CCS), which gives information about the ionic shape of a molecule in the gas phase. We measured the CCSs of 125 common metabolites using traveling-wave ion mobility-mass spectrometry (TW-IM-MS). CCS measurements were highly reproducible on instruments located in three independent laboratories (RSD < 5% for 99%). We also determined the reproducibility of CCS measurements in various biological matrixes including urine, plasma, platelets, and red blood cells using ultra performance liquid chromatography (UPLC) coupled with TW-IM-MS. The mean RSD was < 2% for 97% of the CCS values, compared to 80% of retention times. Finally, as proof of concept, we used UPLC-TW-IM-MS to compare the cellular metabolome of epithelial and mesenchymal cells, an in vitro model used to study cancer development. Experimentally determined and computationally derived CCS values were used as orthogonal analytical parameters in combination with retention time and accurate mass information to confirm the identity of key metabolites potentially involved in cancer. Thus, our results indicate that adding CCS data to searchable databases and to routine metabolomics workflows will increase the identification confidence compared to traditional analytical approaches.

ETD allows for native surface mapping of a 150 kDa noncovalent complex on a commercial Q-TWIMS-TOF instrument

Top-down approaches for the characterization of intact proteins and macromolecular complexes are becoming increasingly popular, since they potentially simplify and speed up the assignment process. Here we demonstrate how, on a commercially available Q-TWIMS-TOF instrument, we performed top-down ETD of the native form of tetrameric alcohol dehydrogenase. We achieved good sequence coverage throughout the first 81 N-terminal amino acids of ADH, with the exception of a loop located on the inside of the protein. This is in agreement with the exposed parts of the natively folded protein according to the crystal structure. Choosing the right precursor charge state and applying supplemental activation were found to be key to obtaining a high ETD fragmentation efficiency. Finally, we briefly discuss opportunities to further increase the performance of ETD based on our results.

Surgical resection of primary tumour improves aerobic performance in colorectal cancer

BACKGROUND

Colorectal cancer is the third most common cancer in the UK, with patients suffering declines in muscle mass and aerobic function. We hypothesised that tumour removal in non-metastatic colorectal cancer would lead to a restoration of lean muscle mass and increases in objective and subjective measures of aerobic performance.

METHODS

We recruited two groups: patients with colorectal cancer (n = 30, 65.3 (51-77) y, body mass index 27.67 (4.83) kg m(-2)) and matched controls (n = 30, 64.6 (42-77) y, BMI 27.14 (3.51) kg m(-2)). Controls underwent a single study while colorectal cancer patients were studied before and 10 months after tumour resection. Aerobic performance was assessed via cardiopulmonary exercise testing and activity questionnaires. Lean muscle mass was measured via dual-energy X-ray absorptiometry.

RESULTS

Lean muscle mass was not different between groups (control: 47.82 (8.23); pre-resection: 52.41 (10.59); post-resection: 52.38 (10.52), kg). Anaerobic threshold was lower in pre-operative patients compared to controls (14.40 (3.23) vs. 19.67 (5.81) ml kg(-1) min(-1), p < 0.0001), increasing significantly post-resection (17.00 (3.56) ml kg(-1) min(-1)p < 0.0001). Self reported maximal physical activity was lower after resection compared to preoperatively (pre-resection 6.0 (6.5-5 IQR), post-resection 3.75 (4-3 IQR), p < 0.0001).

CONCLUSION

In colorectal cancer, anaerobic threshold is reached more rapidly than in matched controls, returning toward normal with tumour resection. Self-reported measures of activity do not mirror this objective change, cardiopulmonary exercise testing may therefore allow for a more accurate evaluation of pre and postoperative performance capability. The variance between objective and subjective measures of exercise capacity may be important in determining return to normal activities.

Characterisation of glycoproteins using a quadrupole time-of-flight mass spectrometer configured for electron transfer dissociation

RATIONALE

Electron transfer dissociation (ETD) within ion trapping mass spectrometers has proven to be a useful tool for the characterisation of post-translational modifications. In this study, we describe the implementation of ETD upon a modified quadrupole time-of-flight (Q-ToF) system and methods for the analysis of glycoproteins.

METHODS

Liquid chromatography electrospray ionisation mass spectrometry (LC/ESI-MS) was performed using a hybrid quadrupole/ion mobility/oa-ToF mass spectrometer equipped with ETD functionality. 1,4-Dicyanobenzene reagent anions necessary for the ETD reaction were generated from a glow discharge region located within the ESI source block. ETD reactions occurred in the stacked ring travelling wave ion guide (located after the quadrupole mass filter and prior to the oa-ToF mass analyser). LC/ETD was performed upon 'super-charged' tryptic glycopeptide ions produced from the recombinant monoclonal antibody trastuzumab. LC/ETD was also performed on ions from the smaller glycopeptides obtained from erythropoietin.

RESULTS

ETD performed upon the quadruply 'super-charged' N-linked glycopeptide ions of trastuzumab and the triply charged O-linked glycopeptide ions of erythropoietin provided both glycosylation site assignments and full sequence information, respectively. Tandem mass (MS/MS) spectra employing collision-induced dissociation (CID) were dominated by oxonium product ions hampering full peptide sequence characterisation.

CONCLUSIONS

LC/ETD on the Q-ToF system proved effective at characterising a number of different N-linked glyco-forms of the tryptic peptide, EEQYNSTYR, from trastuzumab as well as glyco-forms from the O-linked tryptic peptide, EASIPPDAASAAPLR, from erythropoietin. The data demonstrates that the glycopeptide site heterogeneity of trastuzumab and erythropoietin can be accurately characterised. In addition, the post-column mixing of the super-charging reagent, m-NBA, is an effective method to increase the precursor ion charge state and to improve ETD reaction efficiency.

Should laparoscopic reversal of Hartmann's procedure be the first line approach in all patients?

BACKGROUND/AIMS

To assess if the laparoscopic reversal of Hartmann's can be attempted in all patients, without detriment to short or long-term outcomes if the patient is subsequently converted to open.

METHODS

Retrospective review of a prospectively collected database of all reversals under 8 surgeons at a single unit over 105 months, two surgeons attempting laparoscopic reversal in all patients, two pre-selecting for the laparoscopic approach and four utilising the open approach. Long-term follow-up data for re-admissions, re-operations and incisional hernia rate obtained from a postal questionnaire.

RESULTS

45 laparoscopic and 50 primary open reversals were identified. There was no difference in the mean age or previous peritonitis rate in either group. Laparoscopic conversion rate was 29% (13 patients). On intention to treat analysis, a significant difference was identified in the overall 30-day post-operative surgical morbidity (8.9% Laparoscopic-attempted vs 26.0% Open, p = 0.030). There was no difference in operating times (mean 164 vs 172 min, p = 0.896) despite the 13 patients converted to an open procedure. Mean length of stay was significantly lower in the laparoscopic-attempted group at 6.8 days (5.2-8.4) vs 14.9 days (6.4-23.7) in the open group (p = 0.001). Anastomotic leak rates were not statistically different. The median follow up was 27 months (range 6-105); 60% of patients completed a postal follow-up questionnaire. There was no difference in short-term or long-term re-admission or reoperation rates.

CONCLUSIONS

Laparoscopic reversal of Hartamann's is associated with shorter hospital stay and lower morbidity even in unselected patients. Long-term outcomes are similar.

Could Telephone Reviews Reduce Read Mission Rates After Laparoscopic Colorectal Surgery?

Significant advances have been made recently in the management of patients undergoing colorectal surgery. demonstration of the advantages of laparoscopic colorectal surgery over the open approach in terms of faster patient recovery, shorter length of hospital stay, less pain and fewer wound problems with identical oncological outcome has led to the widespread adoption of the technique. Simultaneously, based on the original work of Kehlet, enhanced recovery after surgery (ERAS) programmes that capitalise on the reduced physiological insult stimulated by laparoscopic surgery have gained in popularity. Coupled, laparoscopic surgery and ERAS allow many patients undergoing major colorectal resections to be discharged from hospital on the first to third post-operative day.