Feasibility of a novel exercise prehabilitation programme in patients scheduled for elective colorectal surgery: a feasibility randomised controlled trial.

BACKGROUND AND OBJECTIVES: To investigate the feasibility of delivering a functional exercise-based prehabilitation intervention and its effects on postoperative length of hospital stay, preoperative physical functioning and health-related quality of life in elective colorectal surgery. MATERIALS AND METHODS: In this randomised controlled feasibility trial, 22 elective colorectal surgery patients were randomly assigned to exercise prehabilitation (n = 11) or standard care (n = 11). Feasibility of delivering the intervention was assessed based on recruitment and compliance to the intervention. Impact on postoperative length of hospital stay and complications, preoperative physical functioning (timed up and go test, five times sit to stand, stair climb test, handgrip dynamometry and 6-min walk test) and health-related quality of life were also assessed. RESULTS: Over 42% of patients (84/198) screened were deemed ineligible for prehabilitation due to insufficient time existing prior to scheduled surgery. Of those who were eligible, approximately 18% consented to the trial. Median length of hospital stay was 8 [range 6-27] and 10 [range 5-12] days respectively for the standard care and prehabilitation groups. Patterns towards preoperative improvements for the timed up and go test, stair climb test and 6-min walk test were observed for all participants receiving prehabilitation but not standard care. CONCLUSIONS: Despite prehabilitation appearing to convey positive benefits on physical functioning, short surgical wait times and patient engagement represent major obstacles to implementing exercise prehabilitation programmes in colorectal cancer patients.

Reporting of Randomized Controlled Trials With Statistically Nonsignificant Primary Outcomes Published in High-impact Surgical Journals.

OBJECTIVE: To determine the nature and frequency of distorted presentation or "spin" (ie, specific reporting strategies which highlight that the experimental treatment is beneficial, despite a statistically nonsignificant difference for the primary outcome, or distract the reader from statistically nonsignificant results) in published reports of randomized controlled trials (RCTs) with statistically nonsignificant results for primary outcomes in surgical journals. BACKGROUND: Multiple reports have suggested that interpretation of RCT results in medical journals can be distorted by authors of published reports. METHODS: Using a defined search strategy, RCTs with clearly nonsignificant results for the primary outcome (P > 0.05) form 10 high-impact factor surgical journals (Annals of Surgery, Journal of Neurology, Neurosurgery and Psychiatry, Journal of Heart and Lung Transplantation, American Journal of Transplantation, British Journal of Surgery, Journal of Bone and Joint Surgery, Journal of the American College of Surgeons, Endoscopy, Archives of Surgery, and Liver transplantation), published between July 2013 to July 2015, were identified. Two reviewers independently appraised each selected article using a validated, standardized data abstraction form. RESULTS: In all, 110 eligible RCTs with nonsignificant primary outcomes were appraised. The title was reported with spin in 8 (7%) articles. Forty-four (40%) included abstracts and 39 (35%) main texts were classified as having spin in at least 1 section. The level of spin was high in 16 (14%) abstract and 19 (19%) main-text "Conclusions" sections. Twenty-five articles (23%) recommended the intervention of interest despite a nonsignificant primary outcome. There was no relationship between trial funding source, use of statistician and article section, and the presence of spin. CONCLUSIONS: In RCTs with statistically nonsignificant primary outcomes published in surgical journals, the reporting and interpretation of findings was frequently inconsistent with the results.

A Systematic Review of Outcomes After Transanal Mesorectal Resection for Rectal Cancer.

BACKGROUND: Transanal mesorectal resection has been developed to facilitate minimally invasive proctectomy for rectal cancer. OBJECTIVE: The purpose of this study was to evaluate the evidence regarding technical parameters, oncological outcomes, morbidity, and mortality after transanal mesorectal resection. DATA SOURCES: The Cochrane Library, PubMed, and MEDLINE databases were reviewed. STUDY SELECTION: Systematic review of the literature from January 2005 to September 2015 was used for study selection. INTERVENTION: Intervention included transanal mesorectal resection for rectal cancer. MAIN OUTCOME MEASURES: Technical parameters, histological outcomes, morbidity, and mortality were the outcomes measured. RESULTS: Fifteen predominately retrospective studies involving 449 patients were included (mean age, 64.3 years; 64.1% men). Different platforms were used. The operative mortality rate was 0.4% and the cumulative morbidity rate 35.5%. Circumferential resection margins were clear in 98%, and the resected mesorectum was grade III in 87% of patients. Median follow-up was 14.7 months. There were 4 local recurrences (1.5%) and 12 patients (5.6%) with metastatic disease. No study followed patients long enough to report on 5-year overall and disease-free survival rates. Functional outcome was only reported in 3 studies. LIMITATIONS: A low number of procedures were performed by expert early adopters. There are no comparative or randomized data included in this study and inconsistent reporting of outcome variables. CONCLUSIONS: Transanal mesorectal resection for rectal cancer may enhance negative circumferential margin rates with a reasonable safety profile. Contemporary randomized, controlled studies are required before there can be universal recommendation.

Methane and carbon dioxide emissions from inland waters in India - implications for large scale greenhouse gas balances.

Inland waters were recently recognized to be important sources of methane (CH4 ) and carbon dioxide (CO2 ) to the atmosphere, and including inland water emissions in large scale greenhouse gas (GHG) budgets may potentially offset the estimated carbon sink in many areas. However, the lack of GHG flux measurements and well-defined inland water areas for extrapolation, make the magnitude of the potential offset unclear. This study presents coordinated flux measurements of CH4 and CO2 in multiple lakes, ponds, rivers, open wells, reservoirs, springs, and canals in India. All these inland water types, representative of common aquatic ecosystems in India, emitted substantial amounts of CH4 and a major fraction also emitted CO2 . The total CH4 flux (including ebullition and diffusion) from all the 45 systems ranged from 0.01 to 52.1 mmol m(-2)  d(-1) , with a mean of 7.8 ± 12.7 (mean ± 1 SD) mmol m(-2)  d(-1) . The mean surface water CH4 concentration was 3.8 ± 14.5 µm (range 0.03-92.1 µm). The CO2 fluxes ranged from -28.2 to 262.4 mmol m(-2)  d(-1) and the mean flux was 51.9 ± 71.1 mmol m(-2)  d(-1) . The mean partial pressure of CO2 was 2927 ± 3269 µatm (range: 400-11 467 µatm). Conservative extrapolation to whole India, considering the specific area of the different water types studied, yielded average emissions of 2.1 Tg CH4  yr(-1) and 22.0 Tg CO2  yr(-1) from India's inland waters. When expressed as CO2 equivalents, this amounts to 75 Tg CO2 equivalents yr(-1) (53-98 Tg CO2 equivalents yr(-1) ; ± 1 SD), with CH4 contributing 71%. Hence, average inland water GHG emissions, which were not previously considered, correspond to 42% (30-55%) of the estimated land carbon sink of India. Thereby this study illustrates the importance of considering inland water GHG exchange in large scale assessments.

Munc18-1 is critical for plasma membrane localization of syntaxin1 but not of SNAP-25 in PC12 cells.

Although Munc18-1 was originally identified as a syntaxin1-interacting protein, the physiological significance of this interaction remains unclear. In fact, recent studies of Munc18-1 mutants have suggested that Munc18-1 plays a critical role for docking of secretory vesicles, independent of syntaxin1 regulation. Here we investigated the role of Munc18-1 in syntaxin1 localization by generating stable neuroendocrine cell lines in which Munc18-1 was strongly down-regulated. In these cells, the secretion capability, as well as the docking of dense-core vesicles, was significantly reduced. More importantly, not only was the expression level of syntaxin1 reduced, but the localization of syntaxin1 at the plasma membrane was also severely perturbed. The mislocalized syntaxin1 resided primarily in the perinuclear region of the cells, in which it was highly colocalized with Secretogranin II, a marker protein for dense-core vesicles. In contrast, the expression level and the plasma membrane localization of SNAP-25 were not affected. Furthermore, the syntaxin1 localization and the secretion capability were restored upon transfection-mediated reintroduction of Munc18-1. Our results indicate that endogenous Munc18-1 plays a critical role for the plasma membrane localization of syntaxin1 in neuroendocrine cells and therefore necessitates the interpretation of Munc18-1 mutant phenotypes to be in terms of mislocalized syntaxin1.

Ca2+-dependent activator protein for secretion 1 is critical for constitutive and regulated exocytosis but not for loading of transmitters into dense core vesicles.

Although CAPS1 was originally identified as a soluble factor that reconstitutes Ca(2+)-dependent secretion from permeabilized neuroendocrine cells, its exact function in intact mammalian cells remains controversial. Here we investigate the role for CAPS1 by generating stable cell lines in which CAPS1 is strongly down-regulated. In these cells, Ca(2+)-dependent secretion was strongly reduced not only of catecholamine but also of a transfected neuropeptide. These secretion defects were rescued by infusion of CAPS1-containing brain cytosol or by transfection-mediated expression of CAPS1. Whole cell patch clamp recording revealed significant reductions in slow burst and sustained release components of exocytosis in the knockdown cells. Unexpectedly, they also accumulated higher amounts of endogenous and exogenous transmitters, which were attributable to reductions in constitutive secretion. Electron microscopy did not reveal abnormalities in the number or docking of dense core vesicles. Our results indicate that CAPS1 plays critical roles not only in Ca(2+)-dependent, regulated exocytosis but also in constitutive exocytosis downstream of vesicle docking. However, they do not support the role for CAPS1 in loading transmitters into dense core vesicles.

RalA and RalB function as the critical GTP sensors for GTP-dependent exocytosis.

Although it has been established that the activation of GTPases by non-hydrolyzable GTP stimulates neurotransmitter release from many different secretory cell types, the underlying mechanisms remain unclear. In the present study we aimed to elucidate the functional role(s) for endogenous Ras-like protein A (RalA) and RalB GTPases in GTP-dependent exocytosis. For this purpose stable neuroendocrine pheochromocytoma 12 (PC12) cell lines were generated in which the expressions of both RalA and RalB were strongly downregulated. In these double knock-down cells GTP-dependent exocytosis was reduced severely and was restored after the expression of RalA or RalB was reintroduced by transfection. In contrast, Ca2+-dependent exocytosis and the docking of dense core vesicles analyzed by electron microscopy remained unchanged in the double knock-down cells. Furthermore, the transfected RalA and RalB appeared to be localized primarily on the dense core vesicles in undifferentiated and nerve growth factor-differentiated PC12 cells. Our results indicate that endogenous RalA and RalB function specifically as GTP sensors for the GTP-dependent exocytosis of dense core vesicles, but they are not required for the general secretory pathways, including tethering of vesicles to the plasma membrane and Ca2+-dependent exocytosis.

N-terminal insertion and C-terminal ankyrin-like repeats of alpha-latrotoxin are critical for Ca2+-dependent exocytosis.

Alpha-latrotoxin, a potent stimulator of exocytosis from neurons and neuroendocrine cells, has been studied intensively, but the mechanisms of its actions are poorly understood. Here, we developed a new method to generate active recombinant alpha-latrotoxin and conducted a structure/function analysis of the toxin in stimulating Ca2+-dependent exocytosis. alpha-Latrotoxin consists of a conserved N-terminal domain and C-terminal ankyrin-like repeats. After cleavage of an N-terminally fused purification tag of glutathione S-transferase (GST), the recombinant toxin strongly stimulated exocytosis, whereas the GST-fused toxin was much less potent. The GST-fused toxin bound to the receptors [neurexin 1alpha; CL1 (CIRL/latrophilin 1)] as efficiently as did the GST-cleaved toxin but was much less effective in inserting into the plasma membrane and inducing cation conductance. The toxin with deletion of the last two ankyrin-like repeats still bound the receptors but could neither stimulate exocytosis nor induce cation conductance efficiently. The abilities of the mutated toxins to stimulate exocytosis correlated well with their abilities to induce cation conductance, but not their binding to the receptors. Our results indicate that (1) C-terminal ankyrin-like repeats and a free (unfused) N terminus are both required for the toxin to form pores, which is essential for Ca2+-dependent exocytosis, and (2) receptor binding alone is not sufficient to stimulate Ca2+-dependent exocytosis.