The relationship between sarcopenia and survival at 1 year in patients undergoing elective colorectal cancer surgery

Background: Colorectal cancer remains a common cause of cancer death in the UK, with surgery being the mainstay of treatment. An objective measurement of the suitability of each patient for surgery, and their risk–benefit calculation, would be of great utility. We postulate that sarcopenia (low muscle mass) could fulfil this role as a prognostic indicator. The aim of this study was to determine the relationship between sarcopenia and long-term outcomes in patients undergoing elective bowel resection for colorectal cancer. Methods: One hundred and sixty-three consecutive patients who had elective curative colorectal resection for cancer were eligible for inclusion in the study. Psoas muscle mass was assessed on preoperative computed tomography scan at the level of the L3 vertebra and standardised for patient height (total psoas index, TPI). Sarcopenia (low muscle mass) was defined as < 524 mm2/m2 in males and 385 mm2/m2 in females. In addition to clinical–pathological parameters, postoperative complications were recorded and patients were followed up for mortality for 1 year after surgery. Results: Sarcopenia was present in 19.6% of the study participants and was significantly related to body mass index (p = 0.007), 30-day mortality (p = 0.042) and 1-year mortality (p = 0.046). In univariate analysis, American Society of Anesthesiologists grade (p = 0.016), tumour stage (p = 0.018) and sarcopenia (p = 0.043) were found to be significant independent predictors of 1-year mortality. Conclusions: This study has found sarcopenia to be prevalent in patients with colorectal cancer having elective surgery. Independent of age, sarcopenia was associated with poorer 30-day mortality and survival at 1 year. Measurement of muscle mass preoperatively could be used to stratify a patient’s risk, allowing targeted strategies such as prehabilitation, to be implemented to modify sarcopenia and improve long-term outcomes for patients

Toward sustainable nitrogen management in vegetable production: balancing yield and nitrogen use efficiency

Non-Peer ReviewedCover crops (CC) have the potential to immobilize nutrients, especially nitrogen (N), that would otherwise be lost during post- or pre-harvest periods, leading to improved N management. However, information on how CCs influence N management for vegetable production are scarce. This study aims to determine agronomic responses (yield and N use efficiency, NUE) of three common prairie vegetable crops when produced with and without an overwintering rye CC. In 2017 and repeated in 2018, trials were initiated on a Sutherland clay soil (Dark Brown Chernozem) in Saskatoon for a fully phased broccoli-sweet corn-carrot sequence, with each crop type receiving five N fertilizer treatments (ranging from 0 to 300 kg N ha-1) arranged in a randomized complete block design with three replicates. After harvest, sub-plots were established with vs without a shoulder-season rye CC, and the effect followed into the subsequent growing season. Compared with zero N control, N fertilizer rate did not affect vegetable crop yields in either year, demonstrating the N-rich nature of the soil at this site. Depending on the crop, moderate to high application rates of N significantly reduced crop NUE; N rates above zero N control reduced NUE for sweet corn, rates above 75 kg N ha-1 reduced NUE for broccoli, all rates above 55 kg N ha-1 reduced NUE for the root crop in 2018. Subsequent to the CC in 2018, we found no N fertilizer by CC interaction for crop yields or NUE. The rye CC had no effect on crop yield or NUE for sweet corn or carrot, but significantly reduced broccoli yield and NUE. Regression analysis showed a decreasing trend in NUE with increasing N rates for all three vegetables, regardless of the CC. Our results suggest that the repetition of this experiment for a number of years is necessary to avoid excessive N application and improvement of productivity with cover crops

Developing a soil health assessment protocol for Saskatchewan producers

Non-Peer ReviewedMaintaining and building soil health is an essential component of long-term sustainable agriculture. Soil health can be defined as the capacity of a soil to function, which reflects sustained biological productivity, environmental quality, and plant health. Farmers need appropriate tools or methods for assessing and interpreting the soil health status of their soils, however, there is no standardized and prairie-based soil health test available. Thus, research is needed to address this gap. We currently have a project underway to assess soil health across Saskatchewan, which will contribute to developing a Saskatchewan Soil Health Assessment Protocol (SSHAP). Soil samples from the 0-15, 15-30, and 30-60 cm depth were collected from 56 fields across 26 sites in Sept and Oct 2018. The selected sites represented various Agri-Arm sites, producer fields, and AAFC long-term sites. The selected sites were representative of Saskatchewan agriculture as most sites were previously cropped with wheat or canola; other sites had barley, chickpea, lentil, field pea, soybean, potato, and green manure. Native prairie samples were also collected. Soil samples were air dried and sieved (2mm) prior to analyses. Lab-work in currently underway to characterize soil health attributes, such as wet aggregate stability, active carbon, texture, pH, EC, organic matter, nutrient composition, mineralizable nitrogen, etc. The dataset will enable descriptive statistics for each soil health attribute, form which soil health scoring functions will be explored (similar to the Cornell Soil Health Assessment, but based on Saskatchewan soils). Maintaining soil health is an essential constituent of sustainable agriculture and having an appropriate and standardized method for quantifying and interpreting soil health status a logical first-step

Spectrum of antibacterial activity and mode of action of a novel tris-stilbene bacteriostatic compound

The spectrum of activity and mode of action of a novel antibacterial agent, 135C, was investigated using a range of microbiological and genomic approaches. Compound 135C was active against Gram-positive bacteria with MICs for Staphylococcus aureus ranging from 0.12–0.5 μg/ml. It was largely inactive against Gram-negative bacteria. The compound showed bacteriostatic activity in time-kill studies and did not elicit bacterial cell leakage or cell lysis. Checkerboard assays showed no synergy or antagonism when 135C was combined with a range of other antibacterials. Multi-step serial passage of four S. aureus isolates with increasing concentrations of 135C showed that resistance developed rapidly and was stable after drug-free passages. Minor differences in the fitness of 135C-resistant strains and parent wildtypes were evident by growth curves, but 135C-resistant strains did not show cross-resistance to other antibacterial agents. Genomic comparison of resistant and wildtype parent strains showed changes in genes encoding cell wall teichoic acids. 135C shows promising activity against Gram-positive bacteria but is currently limited by the rapid resistance development. Further studies are required to investigate the effects on cell wall teichoic acids and to determine whether the issue of resistance development can be overcome

The local structure of SO2 and SO3 on Ni(1 1 1): a scanned-energy mode photoelectron diffraction study

O 1s and S 2p scanned-energy mode photoelectron diffraction (PhD) data, combined with multiple-scattering simulations, have been used to determine the local adsorption geometry of the SO2 and SO3 species on a Ni(1 1 1) surface. For SO2, the application of reasonable constraints on the molecular conformation used in the simulations leads to the conclusion that the molecule is centred over hollow sites on the surface, with the molecular plane essentially parallel to the surface, and with both S and O atoms offset from atop sites by almost the same distance of 0.65 Å. For SO3, the results are consistent with earlier work which concluded that surface bonding is through the O atoms, with the S atom higher above the surface and the molecular symmetry axis almost perpendicular to the surface. Based on the O 1s PhD data alone, three local adsorption geometries are comparably acceptable, but only one of these is consistent with the results of an earlier normal-incidence X-ray standing wave (NIXSW) study. This optimised structural model differs somewhat from that originally proposed in the NIXSW investigation

The relationship between aortic calcification and anastomotic leak following gastrointestinal resection: a systematic review

Anastomotic leak (AL) is a significant complication of gastrointestinal (GI) surgery. Impaired perfusion of the anastomosis is thought to play an important role. The degree of aortic calcification (AC) visible on preoperative CT imaging may be associated with an increased risk of AL following GI resection. This review assessed the relationship between AC and AL in patients undergoing GI resection. MEDLINE, EMBASE and the Cochrane library were systematically searched between 1946 and 2019. Relevant keywords were grouped to form a sensitive search strategy: surgical procedure (e.g. digestive system surgical procedure), calcification (e.g. vascular calcification, calcium score) and outcome (e.g. anastomotic leak). Studies assessing the degree of AC on preoperative imaging in relation to AL in adult patients requiring resection and anastomosis were included. The quality of each study was assessed using the Newcastle-Ottawa scale. Bias was assessed using the RevMan risk of bias tool. Nine observational studies were included: four in patients undergoing oesophageal resection (n=1446) and five in patients undergoing colorectal resection (n=556). AL occurred in 20% of patients following oesophagectomy and 14% of patients following colorectal resection. Adjustment for relevant confounders was limited in most studies. Two studies reported a relationship between the degree of AC and AL in patients undergoing oesophagectomy, independent of age and comorbidity. One study reported an association between AC and AL following colorectal resection, while three studies reported higher calcium scores in the iliac arteries of patients who developed colorectal AL. Overall study quality was moderate to good using the Newcastle-Ottawa scale. Detection and reporting bias was evident in the studies examining AL following colorectal resection. The current evidence suggests that the degree of AC may be associated with the development of AL, in particular in patients undergoing oesophagectomy. Further prospective data with adequate adjustment for confounders is required

The UK risk assessment scheme for all non-native species

1. A pest risk assessment scheme, adapted from the EPPO (European and Mediterranean Plant Protection Organisation) scheme, was developed to assess the risks posed to UK species, habitats and ecosystems by non-native taxa. 2. The scheme provides a structured framework for evaluating the potential for non-native organisms, whether intentional or unintentional introductions, to enter, establish, spread and cause significant impacts in all or part of the UK. Specialist modules permit the relative importance of entry pathways, the vulnerability of receptors and the consequences of policies to be assessed and appropriate risk management options to be selected. Spreadsheets for summarising the level of risk and uncertainty, invasive attributes and economic impact were created. In addition, new methods for quantifying economic impact and summarising risk and uncertainty were explored. 3. Although designed for the UK, the scheme can readily be applied elsewhere

The local structure of OH species on the V2O3(0 0 0 1) surface: a scanned-energy mode photoelectron diffraction study

Scanned-energy mode photoelectron diffraction (PhD), using O 1s photoemission, together with multiple-scattering simulations, have been used to investigate the structure of the hydroxyl species, OH, adsorbed on a V2O3(0 0 0 1) surface. Surface OH species were obtained by two alternative methods; reaction with molecular water and exposure to atomic H resulted in closely similar PhD spectra. Both qualitative assessment and the results of multiple-scattering calculations are consistent with a model in which only the O atoms of outermost layer of the oxide surface are hydroxylated. These results specifically exclude significant coverage of OH species atop the outermost V atoms, i.e. in vanadyl O atom sites. Ab initio density-functional theory cluster calculations provide partial rationalisation of this result, which is discussed the context of the general understanding of this system

The pandemic brain: Neuroinflammation in non-infected individuals during the COVID-19 pandemic

While COVID-19 research has seen an explosion in the literature, the impact of pandemic-related societal and lifestyle disruptions on brain health among the uninfected remains underexplored. However, a global increase in the prevalence of fatigue, brain fog, depression and other “sickness behavior”-like symptoms implicates a possible dysregulation in neuroimmune mechanisms even among those never infected by the virus. We compared fifty-seven ‘Pre-Pandemic’ and fifteen ‘Pandemic’ datasets from individuals originally enrolled as control subjects for various completed, or ongoing, research studies available in our records, with a confirmed negative test for SARS-CoV-2 antibodies. We used a combination of multimodal molecular brain imaging (simultaneous positron emission tomography / magnetic resonance spectroscopy), behavioral measurements, imaging transcriptomics and serum testing to uncover links between pandemic-related stressors and neuroinflammation. Healthy individuals examined after the enforcement of 2020 lockdown/stay-at-home measures demonstrated elevated brain levels of two independent neuroinflammatory markers (the 18 kDa translocator protein, TSPO, and myoinositol) compared to pre-lockdown subjects. The serum levels of two inflammatory markers (interleukin-16 and monocyte chemoattractant protein-1) were also elevated, although these effects did not reach statistical significance after correcting for multiple comparisons. Subjects endorsing higher symptom burden showed higher TSPO signal in the hippocampus (mood alteration, mental fatigue), intraparietal sulcus and precuneus (physical fatigue), compared to those reporting little/no symptoms. Post-lockdown TSPO signal changes were spatially aligned with the constitutive expression of several genes involved in immune/neuroimmune functions. This work implicates neuroimmune activation as a possible mechanism underlying the non-virally-mediated symptoms experienced by many during the COVID-19 pandemic. Future studies will be needed to corroborate and further interpret these preliminary findings