Publications by authors named "C W Montgomery"

658 Publications

Bumblebee electric charge stimulates floral volatile emissions in Petunia integrifolia but not in Antirrhinum majus.

Naturwissenschaften 2021 Sep 14;108(5):44. Epub 2021 Sep 14.

School of Biological Sciences, Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK.

The timing of volatile organic compound (VOC) emission by flowering plants often coincides with pollinator foraging activity. Volatile emission is often considered to be paced by environmental variables, such as light intensity, and/or by circadian rhythmicity. The question arises as to what extent pollinators themselves provide information about their presence, in keeping with their long co-evolution with flowering plants. Bumblebees are electrically charged and provide electrical stimulation when visiting plants, as measured via the depolarisation of electric potential in the stem of flowers. Here we test the hypothesis that the electric charge of foraging bumblebees increases the floral volatile emissions of bee pollinated plants. We investigate the change in VOC emissions of two bee-pollinated plants (Petunia integrifolia and Antirrhinum majus) exposed to the electric charge typical of foraging bumblebees. P. integrifolia slightly increases its emissions of a behaviorally and physiologically active compound in response to visits by foraging bumblebees, presenting on average 121 pC of electric charge. We show that for P. integrifolia, strong electrical stimulation (600-700 pC) promotes increased volatile emissions, but this is not found when using weaker electrical charges more representative of flying pollinators (100 pC). Floral volatile emissions of A. majus were not affected by either strong (600-700 pC) or weak electric charges (100 pC). This study opens a new area of research whereby the electrical charge of flying insects may provide information to plants on the presence and phenology of their pollinators. As a form of electroreception, this sensory process would bear adaptive value, enabling plants to better ensure that their attractive chemical messages are released when a potential recipient is present.
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http://dx.doi.org/10.1007/s00114-021-01740-2DOI Listing
September 2021

Arthroscopic Bankart Repair Versus Open Latarjet for First-Time Dislocators in Athletes.

Orthop J Sports Med 2021 Aug 31;9(8):23259671211023803. Epub 2021 Aug 31.

Sports Surgery Clinic, Dublin, Ireland.

Background: In athletes with a first-time shoulder dislocation, arthroscopic Bankart repair (ABR) and the open Latarjet procedure (OL) are the most commonly utilized surgical procedures to restore stability and allow them to return to play (RTP).

Purpose: To compare the outcomes of ABR and OL in athletes with a first-time shoulder dislocation.

Study Design: Cohort study; Level of evidence, 3.

Methods: We performed a retrospective review of patients with first-time shoulder dislocation who underwent primary ABR and OL and had a minimum 24-month follow-up. Indications for OL over ABR in this population were those considered at high risk for recurrence, including patients with glenohumeral bone loss. Patients who underwent ABR were pair-matched in a 2:1 ratio with patients who underwent OL by age, sex, sport, and level of preoperative play. The rate, level, and timing of RTP, as well as the Shoulder Instability-Return to Sport after Injury (SIRSI) score were evaluated. Additionally, we compared recurrence, visual analog scale pain score, Subjective Shoulder Value, Rowe score, satisfaction, and whether patients would undergo the surgery again.

Results: Overall, 80 athletes who underwent ABR and 40 who underwent OL were included, with a mean follow-up of 50.3 months. There was no significant difference between ABR and OL in rate of RTP, return to preinjury level, time to return, or recurrent dislocation rate. There were also no differences between ABR and OL in patient-reported outcome scores or patient satisfaction. When collision athletes were compared between ABR and OL, there were no differences in RTP, SIRSI score, or redislocation rate.

Conclusion: ABR and OL resulted in excellent clinical outcomes, with high rates of RTP and low recurrence rates. Additionally, there were no differences between the procedures in athletes participating in collision sports.
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http://dx.doi.org/10.1177/23259671211023803DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8414621PMC
August 2021

Population sequencing data reveal a compendium of mutational processes in the human germ line.

Science 2021 08 12;373(6558):1030-1035. Epub 2021 Aug 12.

Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA.

Biological mechanisms underlying human germline mutations remain largely unknown. We statistically decompose variation in the rate and spectra of mutations along the genome using volume-regularized nonnegative matrix factorization. The analysis of a sequencing dataset (TOPMed) reveals nine processes that explain the variation in mutation properties between loci. We provide a biological interpretation for seven of these processes. We associate one process with bulky DNA lesions that are resolved asymmetrically with respect to transcription and replication. Two processes track direction of replication fork and replication timing, respectively. We identify a mutagenic effect of active demethylation primarily acting in regulatory regions and a mutagenic effect of long interspersed nuclear elements. We localize a mutagenic process specific to oocytes from population sequencing data. This process appears transcriptionally asymmetric.
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http://dx.doi.org/10.1126/science.aba7408DOI Listing
August 2021

Shc inhibitor idebenone ameliorates liver injury and fibrosis in dietary NASH in mice.

J Biochem Mol Toxicol 2021 Aug 8:e22876. Epub 2021 Aug 8.

Department of Molecular Biosciences, School of Veterinary Medicine, Davis, California, USA.

Shc expression rises in human nonalcoholic steatohepatitis (NASH) livers, and Shc-deficient mice are protected from NASH-thus Shc inhibition could be a novel therapeutic strategy for NASH. Idebenone was recently identified as the first small-molecule Shc inhibitor drug. We tested idebenone in the fibrotic methionine-choline deficient (MCD) diet and the metabolic fast food diet (FFD) mouse models of NASH. In the fibrotic MCD NASH model, idebenone reduced Shc expression and phosphorylation in peripheral blood mononuclear cells and Shc expression in the liver; decreased serum alanine aminotransferase and aspartate aminotransferase; and attenuated liver fibrosis as observed by quantitative polymerase chain reaction (qPCR) and hydroxyproline quantification. In the metabolic FFD model, idebenone administration improved insulin resistance, and reduced inflammation and fibrosis shown with qPCR, hydroxyproline measurement, and histology. Thus, idebenone ameliorates NASH in two mouse models. As an approved drug with a benign safety profile, Idebenone could be a reasonable human NASH therapy.
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http://dx.doi.org/10.1002/jbt.22876DOI Listing
August 2021

Analysis of patients unable to return to play following arthroscopic Bankart repair.

Surgeon 2021 Aug 5. Epub 2021 Aug 5.

Sports Surgery Clinic, Dublin, Ireland.

Purpose: The purpose of this study was to analyze patients that did not return to play (RTP) following arthroscopic Bankart repair (ABR) compared to those who did RTP, and analyze factors associated with not returning to play.

Methods: A retrospective review of patients who underwent ABR, and subsequently did not RTP after a minimum of 24-month follow-up was performed. Additionally, these were pair matched in a 3:1 ratio for age, gender, sport and level of pre-operative play with a control group who RTP. Patients were evaluated for their psychological readiness to return to sport using the SIRSI score. Multivariate regression models were used to evaluate factors affecting RTP.

Results: The study included a total of 52 patients who were unable to RTP and 156 who returned to play. Ten patients (19.2 %) who did not RTP passed the SIRSI benchmark of 56 with a mean overall score of 39.8 ± 24.6, in those who returned 73.0 % passed the SIRSI benchmark of 56 with a mean overall score of 68.9 ± 22.0 (p < 0.0001 for both). The most common primary reasons for not returning were 27 felt physically unable to return, whilst 21 felt it was a natural end to their career or their lifestyle had changed. Multi-logistic regression revealed that 4 of the 12 components of the SIRSI score (p < 0.05 for all) and SSV (p = 0.0049), were the factors that were associated with RTP.

Conclusion: Following ABR, those that do not return to play exhibit poor psychological readiness to return to play, with multi-linear regression revealing the SIRSI questions associated with fear of re-injury were associated with a lower rate of RTP. Additionally, functional limitations were found to be associated with a lower rate of RTP.

Level Of Evidence: Level III; Retrospective Comparative Cohort Study.
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http://dx.doi.org/10.1016/j.surge.2021.06.005DOI Listing
August 2021
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