Effect of Depression Interventions in Patients Undergoing Total Joint Arthroplasty Without a Formal Diagnosis of Depression: A Systematic Review.

PURPOSE: Depression is a notable contributor to suboptimal outcomes after total joint arthroplasty (TJA). We conducted a systematic review of comparative studies to review the available evidence of interventions that affected depression scores and/or outcomes for patients undergoing TJA. METHODS: EMBASE, Ovid MEDLINE, PubMed, and Scopus were reviewed systematically from inception until November 15, 2022. Studies that were relevant for this review included comparative studies between patients who received an intervention within 3 months before or after their primary total hip or knee arthroplasty procedure. The interventions included a wide range of modalities, which were grouped into psychotherapy, enhanced perioperative support, and pharmacotherapy. Other interventions included physiotherapy techniques with a psychological focus, art/music-based therapy, occupational therapy support, and educational interventions. Meta-analysis was conducted for psychotherapy and enhanced support. RESULTS: The final systematic review consisted of 28 relevant studies, most of which were randomized controlled trials. A total of 3,702 patients, with a mean age of 66 years, were considered, of whom 59% were female. Most of the studies reported a notable reduction in depressive symptoms and/or scores based on the interventions being analyzed. At 3 months postoperatively, psychotherapy and enhanced support both resulted in markedly better depression and function scores compared with control subjects, with psychotherapy additionally improving pain scores. CONCLUSIONS: Overall, a wide range of interventions aimed at psychological optimization of patients undergoing TJA can improve depressive symptoms, pain, and function, even in the absence of a formal diagnosis of depression. Specifically, cognitive-based psychotherapy and enhanced perioperative support had the best evidence. Routine pharmacotherapy plays a limited role, if any, in the care of TJA. Additional efforts to develop pragmatic, evidence-based, and reproducible interventions are warranted to continue to optimize outcomes in TJA patients.

The Role of Preoperative Opioid Use in Foot and Ankle Surgery: A Systematic Review.

Prescription opioids, particularly for treating musculoskeletal pain, are a significant contributor to the opioid epidemic in North America. There is also evidence to suggest that chronic use of opioids is associated with poor outcomes after orthopedic surgery. However, whether this association is relevant in foot and ankle surgery is still unclear. Accordingly, a systematic review of the literature was undertaken to assess the impact of preoperative opioid use in patients undergoing foot and ankle surgery concerning postoperative pain, complications, and postoperative opioid dependence. Four databases, including EMBASE, MEDLINE, PubMed, and CINAHL, were searched to March 2022 for studies reporting preoperative opioid use and its effect on postoperative outcomes or opioid use after foot and ankle surgery. A total of 22,092 patients were included in the final synthesis of 8 studies. Most of which were level 3 evidence (5 studies). Around 18% of the patients used opioids preoperatively. Preoperative opioid use was associated with more quantities and prolonged use of opioids postoperatively. Two studies showed an increased risk of complications postoperatively in patients who used opioids preoperatively compared to the nonopioid group. Preoperative opioid use in patients undergoing foot and ankle surgeries is associated with increased and prolonged use of opioids postoperatively and may therefore predict the potential for misuse.

Treatment of Concurrent Depression and Its Effect on Outcomes After Total Joint Arthroplasty: A Systematic Review of Comparative Studies.

PURPOSE: There is a growing body of evidence suggesting that patients with a diagnosis of depression suffer worse outcomes after total joint arthroplasty (TJA) procedures. It is unclear whether depression treatment is a modifiable risk factor that can be targeted to improve suboptimal outcomes. We conducted a systematic review to understand the role that various interventions have on outcomes of TJA in patients with diagnosed depression (PDDs). METHODS: PubMed, Ovid MEDLINE, Scopus, and EMBASE were searched systematically from inception until November 2022. Studies of PDDs who underwent TJA that compared any intervention/treatment of depression with a control group and reported pain, functional outcomes, depression scores, and/or revision rates after TJA were relevant for this review. RESULTS: Ten relevant studies were included in the final systematic review, with a total of 33,501 patients included. Two studies reported lower revision rates for patients receiving selective serotonin reuptake inhibitor treatment and psychotherapy. Two studies showed no difference in functional outcomes for patients receiving pharmacologic treatment. One study reported improved functional outcomes for patients receiving cognitive behavioral therapy and another reported improved postoperative functional outcomes for patients receiving alprazolam. CONCLUSION: Interventions targeted at PDDs may improve short-term pain and functional outcomes, and there may be an association between selective serotonin reuptake inhibitor use and implant survival. The current literature is limited and inconclusive, with important gaps in understanding regarding the optimization and treatment of this modifiable risk factor. Surgeons should consider depression treatment as a method to improve outcomes in this cohort.

Functional Meta-Analysis of the Proteomic Responses of Arabidopsis Seedlings to the Spaceflight Environment Reveals Multi-Dimensional Sources of Variability across Spaceflight Experiments.

The human quest for sustainable habitation of extraterrestrial environments necessitates a robust understanding of life's adaptability to the unique conditions of spaceflight. This study provides a comprehensive proteomic dissection of the Arabidopsis plant's responses to the spaceflight environment through a meta-analysis of proteomics data from four separate spaceflight experiments conducted on the International Space Station (ISS) in different hardware configurations. Raw proteomics LC/MS spectra were analyzed for differential expression in MaxQuant and Perseus software. The analysis of dissimilarities among the datasets reveals the multidimensional nature of plant proteomic responses to spaceflight, impacted by variables such as spaceflight hardware, seedling age, lighting conditions, and proteomic quantification techniques. By contrasting datasets that varied in light exposure, we elucidated proteins involved in photomorphogenesis and skotomorphogenesis in plant spaceflight responses. Additionally, with data from an onboard 1 g control experiment, we isolated proteins that specifically respond to the microgravity environment and those that respond to other spaceflight conditions. This study identified proteins and associated metabolic pathways that are consistently impacted across the datasets. Notably, these shared proteins were associated with critical metabolic functions, including carbon metabolism, glycolysis, gluconeogenesis, and amino acid biosynthesis, underscoring their potential significance in Arabidopsis' spaceflight adaptation mechanisms and informing strategies for successful space farming.

Meta-analysis of the space flight and microgravity response of the Arabidopsis plant transcriptome.

Spaceflight presents a multifaceted environment for plants, combining the effects on growth of many stressors and factors including altered gravity, the influence of experiment hardware, and increased radiation exposure. To help understand the plant response to this complex suite of factors this study compared transcriptomic analysis of 15 Arabidopsis thaliana spaceflight experiments deposited in the National Aeronautics and Space Administration's GeneLab data repository. These data were reanalyzed for genes showing significant differential expression in spaceflight versus ground controls using a single common computational pipeline for either the microarray or the RNA-seq datasets. Such a standardized approach to analysis should greatly increase the robustness of comparisons made between datasets. This analysis was coupled with extensive cross-referencing to a curated matrix of metadata associated with these experiments. Our study reveals that factors such as analysis type (i.e., microarray versus RNA-seq) or environmental and hardware conditions have important confounding effects on comparisons seeking to define plant reactions to spaceflight. The metadata matrix allows selection of studies with high similarity scores, i.e., that share multiple elements of experimental design, such as plant age or flight hardware. Comparisons between these studies then helps reduce the complexity in drawing conclusions arising from comparisons made between experiments with very different designs.

Management of Very Distal Ulna Fractures: A Systematic Review.

OBJECTIVES: To synthesize all-cause complications and reoperations data, and secondary clinical, functional, and radiographic outcomes after the management of very distal ulna fractures (VDUFs) either nonoperatively or operatively. DATA SOURCES: MEDLINE, Embase, and Web of Science were searched for English-language articles from inception to February 17, 2022. STUDY SELECTION: Studies reporting the nonoperative or operative management of VDUFs were eligible for inclusion. VDUFs were defined as either being Q2-Q5 distal ulna fractures using the OTA/AO Comprehensive Classification of Fractures for distal ulna fractures associated with distal radius fractures or being amenable to characterization by the classification system for ulnar head, neck and metaphyseal fractures by Biyani et al. DATA EXTRACTION: Two reviewers independently extracted data from included studies. Study validity was assessed using the methodological index for nonrandomized studies. DATA SYNTHESIS: Seventeen studies (512 VDUFs) were included for analysis. There were 209, 237, and 66 fractures in the nonoperative, open reduction internal fixation (ORIF), and distal ulna resection groups, respectively. Descriptive statistics including weighted mean values, standard deviations, and 95% confidence intervals were calculated. CONCLUSIONS: The treatment of VDUFs with nonoperative management, ORIF, or distal ulna resection may all be acceptable treatment options in specific patient populations. Nonoperative management of VDUFs is a promising treatment strategy even for complex fracture patterns in patients 65 years of age or older. Despite higher reoperation rates, ORIF may be considered for the younger, high-demand patient. Distal ulna resection presents with very favorable functional outcomes in patients 65 years of age or older presenting with a complex VDUF with the lowest reoperation rate across all groups. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Effect of Local Antibiotic Prophylaxis on Postoperative Deep Infection in Fracture Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVES: Despite the use of systemic antibiotic prophylaxis, postoperative infection after fracture surgery remains an issue. The purpose of this systematic review and meta-analysis was to evaluate the effect of locally applied antibiotics on deep infection in fracture surgery in both the open and closed fractures. DATA SOURCES: A comprehensive search of MEDLINE, Embase, and PubMed was performed from the date of inception to April 15, 2021, and included studies in all languages. STUDY SELECTION: Cohort studies were eligible if they investigated the effect on the infection rate of local antibiotic prophylaxis on deep infection after fracture surgery. DATA EXTRACTION: This study was conducted according to the Cochrane Handbook for Systematic Reviews and reported as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Risk of bias was assessed using version 2 of the Cochrane risk-of-bias tool for randomized trials and the Methodological Index for Nonrandomized Studies tool where applicable. DATA SYNTHESIS: An inverse variance random-effects model was the primary analysis model because of the anticipated diversity in the evaluated populations. Univariate models were used when a single outcome was of interest. CONCLUSIONS: The risk of deep infection was significantly reduced when local antibiotics were applied compared with the control group receiving systemic prophylaxis only. This beneficial effect was observed in open fractures but failed to reach statistical significance in closed fractures. This meta-analysis suggests that there may be a significant risk reduction in deep infection rate after fracture surgery when local antibiotics are added to standard systemic prophylaxis, particularly in open fractures. Further high-powered Level I studies are needed to support these findings. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Video-based coaching for surgical residents: a systematic review and meta-analysis.

BACKGROUND: Video-based coaching (VBC) is used to supplement current teaching methods in surgical education and may be useful in competency-based frameworks. Whether VBC can effectively improve surgical skill in surgical residents has yet to be fully elucidated. The objective of this study is to compare surgical residents receiving and not receiving VBC in terms of technical surgical skill. METHODS: The following databases were searched from database inception to October 2021: Medline, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and PubMed. Articles were included if they were randomized controlled trials (RCTs) comparing surgical residents receiving and not receiving VBC. The primary outcome, as defined prior to data collection, was change in objective measures of technical surgical skill following implementation of either VBC or control. A pairwise meta-analyses using inverse variance random effects was performed. Standardized mean differences (SMD) were used as the primary outcome measure to account for differences in objective surgical skill evaluation tools. RESULTS: From 2734 citations, 11 RCTs with 157 residents receiving VBC and 141 residents receiving standard surgical teaching without VBC were included. There was no significant difference in post-coaching scores on objective surgical skill evaluation tools between groups (SMD 0.53, 95% CI 0.00 to 1.01, p = 0.05, I2 = 74%). The improvement in scores pre- and post-intervention was significantly greater in residents receiving VBC compared to those not receiving VBC (SMD 1.62, 95% CI 0.62 to 2.63, p = 0.002, I2 = 85%). These results were unchanged with leave-one-out sensitivity analysis and subgroup analysis according to operative setting. CONCLUSION: VBC can improve objective surgical skills in surgical residents of various levels. The benefit may be most substantial for trainees with lower baseline levels of objective skill. Further studies are required to determine the impact of VBC on competency-based frameworks.

Metabolism of Scenedesmus obliquus cultivated with raw plant substrates.

The potential benefits of adding raw, non-food, lignocellulosic plant material as a carbon source for mixotrophic growth of microalgae have previously been demonstrated. This approach has advantages over using traditional carbon sources like glucose or acetate due to wide-spread plant biomass availability and substrate recalcitrance to bacterial contamination. Here, we report the overall growth characteristics and explore the metabolic patterns of Scenedesmus obliquus cultured in the presence raw plant substrate. An initial screen of plant substrate candidates showed an increase in specific growth rate and biomass accumulation when S. obliquus was cultured in the presence of switchgrass or yard waste compared to media alone. We observed a near doubling of microalgal dry weight when S. obliquus was grown with 0.2% (w/v) switchgrass under ambient CO2. Scanning electron microscopy (SEM) of corn stem after S. obliquus cultivation exhibited substantial phloem degradation. Transcriptomic analyses of S. obliquus during mid- and late-log phase growth revealed a dynamic metabolic landscape within many KEGG pathways. Notably, differential expression was observed for several potential glycosyl hydrolases. We also investigated the influence of switchgrass on the growth of S. obliquus at 50 L volume in mini raceway ponds to determine the scalability of this approach.

COVID-19 and the transition to virtual teaching sessions in an orthopaedic surgery training program: a survey of resident perspectives.

BACKGROUND: COVID-19 has had a tremendous impact on medical education. Due to concerns of the virus spreading through gatherings of health professionals, in-person conferences and rounds were largely cancelled. The purpose of this study is the evaluate the implementation of an online educational curriculum by a major Canadian orthopaedic surgery residency program in response to COVID-19. METHODS: A survey was distributed to residents of a major Canadian orthopaedic surgery residency program from July 10th to October 24th, 2020. The survey aimed to assess residents' response to this change and to examine the effect that the transition has had on their participation, engagement, and overall educational experience. RESULTS: Altogether, 25 of 28 (89%) residents responded. Respondents generally felt the quality of education was superior (72%), their level of engagement improved (64%), and they were able to acquire more knowledge (68%) with the virtual format. Furthermore, 88% felt there was a greater diversity of topics, and 96% felt there was an increased variety of presenters. Overall, 76% of respondents felt that virtual seminars better met their personal learning objectives. Advantages reported were increased accessibility, greater convenience, and a wider breadth of teaching faculty. Disadvantages included that the virtual sessions felt less personal and lacked dynamic feedback to the presenter. CONCLUSIONS: Results of this survey reveal generally positive attitudes of orthopaedic surgery residents about the transition to virtual learning in the setting of an ongoing pandemic. This early evaluation and feedback provides valuable guidance on how to grow this novel curriculum and bring the frontier of virtual teaching to orthopaedic education long-term.

Reverse Total Shoulder Arthroplasty Is the Most Cost-effective Treatment Strategy for Proximal Humerus Fractures in Older Adults: A Cost-utility Analysis.

BACKGROUND: Proximal humerus fractures are the second-most common fragility fracture in older adults. Although reverse total shoulder arthroplasty (RTSA) is a promising treatment strategy for proximal humerus fractures with favorable clinical and quality of life outcomes, it is associated with much higher, and possibly prohibitive, upfront costs relative to nonoperative treatment and other surgical alternatives. QUESTIONS/PURPOSES: (1) What is the cost-effectiveness of open reduction internal fixation (ORIF), hemiarthroplasty, and RTSA compared with the nonoperative treatment of complex proximal humerus fractures in adults older than 65 years from the perspective of a single-payer Canadian healthcare system? (2) Which factors, if any, affect the cost-effectiveness of ORIF, hemiarthroplasty, and RTSA compared with nonoperative treatment of proximal humerus fractures including quality of life outcomes, cost, and complication rates after each treatment? METHODS: This cost-utility analysis compared RTSA, hemiarthroplasty, and ORIF with the nonoperative management of complex proximal humerus fractures in adults older than 65 years over a lifetime time horizon from the perspective of a single-payer healthcare system. Short-term and intermediate-term complications in the 2-year postoperative period were modeled using a decision tree, with long-term outcomes estimated through a Markov model. The model was initiated with a cohort of 75-year-old patients who had a diagnosis of a comminuted (three- or four-part) proximal humerus fractures; 90% of the patients were women. The mean age and gender composition of the model's cohort was based on a systematic review conducted as part of this analysis. Patients were managed nonoperatively or surgically with either ORIF, hemiarthroplasty, or RTSA. The three initial surgical treatment options of ORIF, hemiarthroplasty, and RTSA resulted in uncomplicated healing or the development of a complication that would result in a subsequent surgical intervention. The model reflects the complications that result in repeat surgery and that are assumed to have the greatest impact on clinical outcomes and costs. Transition probabilities and health utilities were derived from published sources, with costs (2020 CAD) sourced from regional costing databases. The primary outcome was the incremental cost-utility ratio, which was calculated using expected quality-adjusted life years (QALYs) gained and costs. Sensitivity analyses were conducted to explore the impact of changing key model parameters. RESULTS: Based on both pairwise and sequential analysis, RTSA was found to be the most cost-effective strategy for managing complex proximal humerus fractures in adults older than 65 years. Compared with nonoperative management, the pairwise incremental cost-utility ratios of hemiarthroplasty and RTSA were CAD 25,759/QALY and CAD 7476/QALY, respectively. ORIF was dominated by nonoperative management, meaning that it was both more costly and less effective. Sequential analysis, wherein interventions are compared from least to most expensive in a pairwise manner, demonstrated ORIF to be dominated by hemiarthroplasty, and hemiarthroplasty to be extendedly dominated by RTSA. Further, at a willingness-to-pay threshold of CAD 50,000/QALY, RTSA had 66% probability of being the most cost-effective treatment option. The results were sensitive to changes in the parameters for the probability of revision RTSA after RTSA, the treatment cost of RTSA, and the health utilities associated with the well state for all treatment options except ORIF, although none of these changes were found to be clinically realistic based on the existing evidence. CONCLUSION: Based on this economic analysis, RTSA is the preferred treatment strategy for complex proximal humerus fractures in adults older than 65 years, despite high upfront costs. Based on the evidence to date, it is unlikely that the parameters this model was sensitive to would change to the degree necessary to alter the model's outcome. A major strength of this model is that it reflects the most recent randomized controlled trials evaluating the management of this condition. Therefore, clinicians should feel confident recommending RTSA for the management of proximal humerus fractures in adults older than 65 years, and they are encouraged to advocate for this intervention as being a cost-effective practice, especially in publicly funded healthcare systems wherein resource stewardship is a core principle. Future high-quality trials should continue to collect both clinical and quality of life outcomes using validated tools such as the EuroQOL-5D to reduce parameter uncertainty and support decision makers in understanding relevant interventions' value for money. LEVEL OF EVIDENCE: Level III, economic and decision analysis.

The Use of Rifampin in Total Joint Arthroplasty: A Systematic Review and Meta-Analysis of Comparative Studies.

BACKGROUND: Periprosthetic joint infection (PJI) is a devastating complication of total joint arthroplasty (TJA). Rifampin is an antibiotic with the ability to penetrate bacterial biofilms, and thus has been considered as a potentially important adjunct in the prevention and treatment of PJI. The aim of this systematic review is to evaluate and summarize the use of rifampin in TJA, particularly in the context of PJI. METHODS: A literature search of all relevant electronic databases was performed. All comparative studies assessing the use of rifampin in the context of TJA were included. Descriptive data are reported, and a meta-analysis was performed using all studies which compared the addition of rifampin to standard care in treating PJI. RESULTS: A total of 33 studies met inclusion criteria. A meta-analysis of 22 studies comparing the addition of rifampin to standard care for treating PJI found a significant reduction in failure rates (26.0% vs 35.9%; odds ratio 0.61, 95% confidence interval 0.43-0.86). The protective effect of rifampin was maintained in studies which included exchange arthroplasty as a treatment strategy, but not in studies only using an implant retention strategy. Among studies reporting adverse events of rifampin, there was a 20.5% adverse event rate. CONCLUSION: Overall, rifampin appears to confer a protective effect against treatment failure following PJI. This treatment effect is particularly pronounced in the context of exchange arthroplasty. Further high-level evidence is needed to clarify the exact indications and doses of rifampin which can most effectively act as an adjunct in the treatment of PJI. LEVEL OF EVIDENCE: Level III, Systematic Review and Meta-Analysis of Level I-III Studies.

Nitric oxide, gravity response, and a unified schematic of plant signaling.

Plant signaling components are often involved in numerous processes. Calcium, reactive oxygen species, and other signaling molecules are essential to normal biotic and abiotic responses. Yet, the summation of these components is integrated to produce a specific response despite their involvement in a myriad of response cascades. In the response to gravity, the role of many of these individual components has been studied, but a specific sequence of signals has not yet been assembled into a cohesive schematic of gravity response signaling. Herein, we provide a review of existing knowledge of gravity response and differential protein and gene regulation induced by the absence of gravity stimulus aboard the International Space Station and propose an integrated theoretical schematic of gravity response incorporating that information. Recent developments in the role of nitric oxide in gravity signaling provided some of the final contextual pillars for the assembly of the model, where nitric oxide and the role of cysteine S-nitrosation may be central to the gravity response. The proposed schematic accounts for the known responses to reorientation with respect to gravity in roots-the most well studied gravitropic plant tissue-and is supported by the extensive evolutionary conservation of regulatory amino acids within protein components of the signaling schematic. The identification of a role of nitric oxide in regulating the TIR1 auxin receptor is indicative of the broader relevance of the schematic in studying a multitude of environmental and stress responses. Finally, there are several experimental approaches that are highlighted as essential to the further study and validation of this schematic.

Short-term outcomes vary by surgical approach in total hip arthroplasty: a network meta-analysis.

BACKGROUND: The direct anterior approach (DAA) has increased in popularity in recent years. Proponents cite its muscle-sparing approach and purported reduction in pain and improvement in function when compared to the traditional surgical approaches. There remains controversy surrounding the validity of these claims. The objective of this study was to compare the common total hip surgical approaches in terms of pain scores, functional outcomes, opioid use and complications within the first 12 weeks postoperatively. METHODS: A network meta-analysis of randomized controlled trials (RCT) comparing postoperative outcomes of different surgical approaches in primary THA up to 12 weeks was performed. PubMed, MEDLINE, Embase, Web of Science and SCOPUS were systematically searched from inception to May 2020. Outcomes included pain scores, functional outcome scores, length of stay (LOS), complications and opioid consumption. RESULTS: Twenty-five RCTs (n = 2339) were included. The DAA demonstrated statistically significant improvement in Harris Hip Scores at 6 weeks when compared to the posterior and direct lateral approaches. The DAA reduced pain scores on postoperative day 2 and at 2 weeks compared to the direct lateral approach. The anterolateral approach was found to have a significantly shorter LOS compared to the other major surgical approaches. The differences in functional outcomes or pain scores did not surpass conventional cutoffs for a minimal clinically important difference. CONCLUSION: The DAA led to functional improvements at 6 weeks compared to the posterior and direct lateral approaches and reduced postoperative pain compared to the direct lateral approach. However, these improvements failed to reach clinical significance. All major surgical approaches led to large improvements in function by 12 weeks with relatively low complication rates. Whether a short-term statistically significant improvement in function is sufficiently patient important to recommend DAA as a standard remains uncertain.

Posterior mesorectal thickness as a predictor of increased operative time in rectal cancer surgery: a retrospective cohort study.

BACKGROUND: In rectal cancer surgery, larger mesorectal fat area has been shown to correlate with increased intraoperative difficulty. Prior studies were mostly in Asian populations with average body mass indices (BMIs) less than 25 kg/m2. This study aimed to define the relationship between radiological variables on pelvic magnetic resonance imaging (MRI) and intraoperative difficulty in a North American population. METHODS: This is a single-center retrospective cohort study analyzing all patients who underwent low anterior resection (LAR) or transanal total mesorectal excision (TaTME) for stage I-III rectal adenocarcinoma from January 2015 until December 2019. Eleven pelvic magnetic resonance imaging measures were defined a priori according to previous literature and measured in each of the included patients. Operative time in minutes and intraoperative blood loss in milliliters were utilized as the primary indicators of intraoperative difficulty. RESULTS: Eighty-three patients (39.8% female, mean age: 62.4 ± 11.6 years) met inclusion criteria. The mean BMI of included patients was 29.4 ± 6.2 kg/m2. Mean operative times were 227.2 ± 65.1 min and 340.6 ± 78.7 min for LARs and TaTMEs, respectively. On multivariable analysis including patient, tumor, and MRI factors, increasing posterior mesorectal thickness was significantly associated with increased operative time (p = 0.04). Every 1 cm increase in posterior mesorectal thickness correlated with a 26 min and 6 s increase in operative time. None of the MRI measurements correlated strongly with BMI. CONCLUSION: As the number of obese rectal cancer patients continues to expand, strategies aimed at optimizing their surgical management are paramount. While increasing BMI is an important preoperative risk factor, the present study identifies posterior mesorectal thickness on MRI as a reliable and easily measurable parameter to help predict operative difficulty. Ultimately, this may in turn serve as an indicator of which patients would benefit most from pre-operative resources aimed at optimizing operative conditions and postoperative recovery.

Plant Proteomic Data Acquisition and Data Analyses: Lessons from Spaceflight.

Proteomics has the capacity to identify and quantify the proteins present in a sample. The technique has been used extensively across all model organisms to study various physiological processes and signaling pathways. In addition to providing a global view of regulatory processes inside a cell, proteomics can also be used to identify candidate genes and retrieve information on alternative isoforms of known proteins. Here, we provide protocols for protein extraction from Arabidopsis thaliana seedlings and describe analysis techniques used after data collection. This approach was originally used for the Biological Research in Canisters (BRIC) 20 spaceflight experiment but is valid for any ground-based or flight experiment. Extraction protocols for soluble and membrane proteins and basic analysis and quality metrics for MS/MS data are provided. Avenues for data analysis post-MS/MS data acquisition and details of software that can be used in gathering structural data on proteins of interest are also included. Use of differential abundance and network-based approaches for proteomics data analyses can reveal regulatory patterns not apparent through differential abundance or transcriptomic data alone.

Evidence for phloem loading via the abaxial bundle sheath cells in maize leaves.

Leaves are asymmetric, with different functions for adaxial and abaxial tissue. The bundle sheath (BS) of C3 barley (Hordeum vulgare) is dorsoventrally differentiated into three types of cells: adaxial structural, lateral S-type, and abaxial L-type BS cells. Based on plasmodesmatal connections between S-type cells and mestome sheath (parenchymatous cell layer below bundle sheath), S-type cells likely transfer assimilates toward the phloem. Here, we used single-cell RNA sequencing to investigate BS differentiation in C4 maize (Zea mays L.) plants. Abaxial BS (abBS) cells of rank-2 intermediate veins specifically expressed three SWEET sucrose uniporters (SWEET13a, b, and c) and UmamiT amino acid efflux transporters. SWEET13a, b, c mRNAs were also detected in the phloem parenchyma (PP). We show that maize has acquired a mechanism for phloem loading in which abBS cells provide the main route for apoplasmic sucrose transfer toward the phloem. This putative route predominates in veins responsible for phloem loading (rank-2 intermediate), whereas rank-1 intermediate and major veins export sucrose from the PP adjacent to the sieve element companion cell complex, as in Arabidopsis thaliana. We surmise that abBS identity is subject to dorsoventral patterning and has components of PP identity. These observations provide insights into the unique transport-specific properties of abBS cells and support a modification to the canonical phloem loading pathway in maize.

NASA GeneLab RNA-seq consensus pipeline: standardized processing of short-read RNA-seq data.

With the development of transcriptomic technologies, we are able to quantify precise changes in gene expression profiles from astronauts and other organisms exposed to spaceflight. Members of NASA GeneLab and GeneLab-associated analysis working groups (AWGs) have developed a consensus pipeline for analyzing short-read RNA-sequencing data from spaceflight-associated experiments. The pipeline includes quality control, read trimming, mapping, and gene quantification steps, culminating in the detection of differentially expressed genes. This data analysis pipeline and the results of its execution using data submitted to GeneLab are now all publicly available through the GeneLab database. We present here the full details and rationale for the construction of this pipeline in order to promote transparency, reproducibility, and reusability of pipeline data; to provide a template for data processing of future spaceflight-relevant datasets; and to encourage cross-analysis of data from other databases with the data available in GeneLab.

Transcriptome profiling of insulin sensitive tissues from GH deficient mice following GH treatment.

PURPOSE: Most studies that have examined the transcriptional response to GH have been performed with a single tissue. Thus, the current study performed RNASeq across three insulin-sensitive tissues of GH-treated GH deficient (GHKO) mice. METHODS: GHKO mice were injected with recombinant human GH (hGH) or vehicle daily for 5 days and adipose, liver, and muscle tissues were collected 4 h after the final injection. RNA was isolated from the tissues and sequenced. Genes that were differentially expressed between GH and vehicle treatments were further analyzed. Enrichment analysis and topology-aware pathway analysis were performed. RESULTS: GHKO mice treated with hGH had expected phenotypic alterations, with increased body, fat, fluid, liver, and muscle mass, and increased serum IGF-1 and insulin. 55 Genes were differentially expressed in all three tissues, including the canonical GH targets Igf1, Igfals, and Cish. Enrichment analysis confirmed the canonical GH response in select tissues, such as cell proliferation, metabolism, and fibrosis. The JAK/STAT pathway was the only pathway significantly altered in all three tissues. CONCLUSIONS: As expected, GH caused expression changes of many known target genes, although new candidate GH targets were identified. Liver and muscle appear to be more GH sensitive than adipose tissue due to the larger number of DEG and pathways significantly altered, but adipose still has a characteristic GH response. The diversity of changes uncovered in all three tissues after 5 days of GH treatment highlights the multiplicity of GH's effects in its target tissues.