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140 citation(s) found for "Luther, E".

Efficacy of bevacizumab-based treatment in early-onset treatment-naïve metastatic colorectal cancer patients: An ARCAD database analysis.
Fiskum, Jack, Hurwitz, Herbert I. , Fuchs, Charles S. , Hecht, J. Randolph, Punt, Cornelis J.A. , Heinemann, Volker , Gramont, Aimery de , Jin, Zhaohui , Dixon, Jesse G. , Hubbard, Joleen M. , Eng, Cathy , Lieu, Christopher H. , Saltz, Leonard B. , Venook, Alan P. , Schmoll, Hans‐Joachim , Cremolini, Chiara , Díaz‐Rubio, Eduardo , Tebbutt, Niall C. , Yoshino, Takayuki , Shi, Qian

Journal of Clinical Oncology | January 19, 2022 | Volume: 40 | Issue: 4_suppl | Pages: 101-101

10.1200/jco.2022.40.4_suppl.101 Get It

101 Background: Colorectal cancer (CRC) incidence and mortality have decreased since the 1970s, but the incidence in young adults (20-49 years, named early-onset CRC, eoCRC) has been increasing. eoCRC patients with metastatic disease are treated with the same standard regimens as late-onset CRC (loCRC, age ≥ 50 years) although detailed response data for eoCRC are largely missing. Methods: Individual patient data on 7,604 subjects with metastatic eoCRC from 11 first line randomized bevacizumab studies between 2000 and 2012 in the ARCAD advanced colorectal cancer database were pooled. The distributions of demographics, clinicopathological features, biomarkers, and outcome data were summarized by age groups. Progression-free survival (PFS) and overall survival (OS) were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for potential confounders. Predictive value of age group was evaluated by testing interaction effect between treatment and age variables. Results: Female eoCRC are more commonly seen compared to loCRC (46.8% vs. 38.7%, p<0.0001). Patients with eoCRC (n=1,289) were significantly more likely to have had prior metastasectomy (17.5% vs. 13.5%, p=0.043) and lung metastatic disease (67% vs. 59.8%, p<0.001), but less likely to have distant lymph node metastatic disease (58.8 vs. 62.9%, p=0.036) or KRAS mutation (29.2% vs. 34.4%, p=0.042) compared to those with loCRC (n=6,315). eoCRC and loCRC patients had similar distributions according to PS, primary tumor sidedness, prior primary tumor resection, liver involvement, peritoneal involvement, number of metastatic sites, NRAS and BRAF. Age of disease onset was not a statistically significant prognostic factor for PFS in univariate and multivariate analysis (seen in table). Bevacizumab in addition to chemo improved PFS in eoCRC population (9.9 vs. 6.8 months, HR = 0.66, p<0.001), which was similar to the findings in loCRC population (9.4 vs. 7.3 months, HR= 0.73, p<0.001, interaction p=0.54). By multivariate analysis, a greater improvement in PFS was noted for the addition of bevacizumab in eoCRC relative to LoCRC patients (HR = 0.62 vs. HR = 0.82). Conclusions: Treatment naive eoCRC patients with metastatic disease derive similar benefit from bevacizumab relative to their average age counterparts.[Table: see text]
Clinical Trial Endpoints in Metastatic Cancer: Using Individual Participant Data to Inform Future Trials Methodology
Goldberg, Richard M. , Adams, Richard , Buyse, Marc , Eng, Cathy , Grothey, Axel , André, Thierry , Sobrero, Alberto , Lichtman, Stuart M. , Benson, Al B. , Punt, Cornelis J.A. , Maughan, Tim , Sommeijer, Dirkje W. , Saad, Everardo D. , Shi, Qian , Coart, Elisabeth , Chibaudel, Benoist , Koopman, Miriam , Schmoll, Hans‐Joachim , Taı̈eb, Julien , Matheson, Alastair , Gramont, Aimery de , Burzykowski, Tomasz , Saad, Everardo D , Shi, Qian , Koopman, Miriam , Schmoll, Hans-Joachim , Taieb, Julien , Tebbutt, Niall C , Zalcberg, John , Tabernero, Josep , Van Cutsem, Eric , De Gramont, Aimery , André, Thierry , Maughan, Timothy S , Lichtman, Stuart M , Adams, Richard , Buyse, Marc E , Eng, Cathy , Chibaudel, Benoist , Burzykowski, Tomasz , Yoshino, Takayuki , Tebbutt, Niall C. , Zalcberg, John , Tabernero, Josep , Cutsem, Eric Van

JNCI: Journal of the National Cancer Institute | November 30, 2021 | Volume: 114 | Issue: 6 | Pages: 819-828

10.1093/jnci/djab218 | PMID 34865086 Get It

Abstract Meta-analysis based on individual participant data (IPD) is a powerful methodology for synthesizing evidence by combining information drawn from multiple trials. Hitherto, its principal application has been in questions of clinical management, but an increasingly important use is in clarifying trials methodology, for instance in the selection of endpoints, as discussed in this review. In oncology, the Aide et Recherche en Cancérologie Digestive (ARCAD) Metastatic Colorectal Cancer Database is a leader in the use of IPD-based meta-analysis in methodological research. The ARCAD database contains IPD from more than 38 000 patients enrolled in 46 studies and continues to collect phase III trial data. Here, we review the principal findings of the ARCAD project in respect of endpoint selection and examine their implications for cancer trials. Analysis of the database has confirmed that progression-free survival (PFS) is no longer a valid surrogate endpoint predictive of overall survival in the first-line treatment of colorectal cancer. Nonetheless, PFS remains an endpoint of choice for most first-line trials in metastatic colorectal cancer and other solid tumors. Only substantial PFS effects are likely to translate into clinically meaningful benefits, and accordingly, we advocate an oncology research model designed to identify highly effective treatments in carefully defined patient groups. We also review the use of the ARCAD database in assessing clinical response including novel response metrics and prognostic markers. These studies demonstrate the value of IPD as a tool for methodological studies and provide a reference point for the expansion of this approach within clinical cancer research.
Reevaluating Disease-Free Survival as an Endpoint vs Overall Survival in Stage III Adjuvant Colon Cancer Trials
Yin, Jun , Salem, Mohamed E. , Dixon, Jesse G. , Jin, Zhaohui , Cohen, Romain , DeGramont, Aimery, Taı̈eb, Julien , Alberts, Steven R. , Schmoll, Hans‐Joachim , George, Thomas J. , Goldberg, Richard M. , Lonardi, Sara , Shi, Qian , Taieb, Julien , Alberts, Steven R , George, Thomas J , Goldberg, Richard M , Kerr, Rachel , Lonardi, Sara , Yothers, Greg , André, Thierry , Shi, Qian , Schmoll, Hans-Joachim , Jin, Zhaohui , Cohen, Romain , Dixon, Jesse G , Gramont, Aimery de , Cutsem, Eric Van , Wolmark, Norman , Saltz, Leonard B. , Kerr, Rachel , Yoshino, Takayuki , Yothers, Greg , Grothey, Axel , André, Thierry

JNCI: Journal of the National Cancer Institute | September 8, 2021 | Volume: 114 | Issue: 1 | Pages: 60-67

10.1093/jnci/djab187 | PMID 34505880 Get It

Abstract Background Disease-free survival (DFS) with a 3-year median follow-up (3-year DFS) was validated as a surrogate for overall survival (OS) with a 5-year median follow-up (5-year OS) in adjuvant chemotherapy colon cancer (CC) trials. Recent data show further improvements in OS and survival after recurrence in patients who received adjuvant FOLFOX. Hence, reevaluation of the association between DFS and OS and determination of the optimal follow-up duration of OS to aid its utility in future adjuvant trials are needed. Methods Individual patient data from 9 randomized studies conducted between 1998 and 2009 were included; 3 trials tested biologics. Trial-level surrogacy examining the correlation of treatment effect estimates of 3-year DFS with 5 to 6.5-year OS was evaluated using both linear regression (RWLS2) and Copula bivariate (RCopula2) models and reported with 95% confidence intervals (CIs). For R2, a value closer to 1 indicates a stronger correlation. Results Data from a total of 18 396 patients were analyzed (median age = 59 years; 54.0% male), with 54.1% having low-risk tumors (T1-3 and N1), 31.6% KRAS mutated, 12.3% BRAF mutated, and 12.4% microsatellite instability high or deficient mismatch repair tumors. Trial-level correlation between 3-year DFS and 5-year OS remained strong (RWLS2 = 0.82, 95% CI = 0.67 to 0.98; RCopula2 = 0.92, 95% CI = 0.83 to 1.00) and increased as the median follow-up of OS extended. Analyses limited to trials that tested biologics showed consistent results. Conclusions Three-year DFS remains a validated surrogate endpoint for 5-year OS in adjuvant CC trials. The correlation was likely strengthened with 6 years of follow-up for OS.
Social and Behavioral Determinants of Health in the Era of Artificial Intelligence with Electronic Health Records: A Scoping Review
Bompelli, Anusha , Wang, Yanshan , Wan, Ruyuan , Singh, Esha, Zhou, Yuqi, Xu, Lin , Oniani, David , Kshatriya, Bhavani Singh Agnikula, Balls‐Berry, Joyce E. , Zhang, Rui , Balls-Berry, Joyce Joy E , Wang, Yanshan , Bompelli, Anusha , Wan, Ruyuan , Singh, Esha, Zhou, Yuqi, Xu, Lin , Oniani, David , Kshatriya, Bhavani Singh Agnikula, Zhang, Rui

Health Data Science | August 24, 2021 | Volume: 2021 | Issue: No issue available | Pages: No page available

10.34133/2021/9759016 | PMID 38487504 Get It

Background . There is growing evidence that social and behavioral determinants of health (SBDH) play a substantial effect in a wide range of health outcomes. Electronic health records (EHRs) have been widely employed to conduct observational studies in the age of artificial intelligence (AI). However, there has been limited review into how to make the most of SBDH information from EHRs using AI approaches. Methods . A systematic search was conducted in six databases to find relevant peer-reviewed publications that had recently been published. Relevance was determined by screening and evaluating the articles. Based on selected relevant studies, a methodological analysis of AI algorithms leveraging SBDH information in EHR data was provided. Results . Our synthesis was driven by an analysis of SBDH categories, the relationship between SBDH and healthcare-related statuses, natural language processing (NLP) approaches for extracting SBDH from clinical notes, and predictive models using SBDH for health outcomes. Discussion . The associations between SBDH and health outcomes are complicated and diverse; several pathways may be involved. Using NLP technology to support the extraction of SBDH and other clinical ideas simplifies the identification and extraction of essential concepts from clinical data, efficiently unlocks unstructured data, and aids in the resolution of unstructured data-related issues. Conclusion . Despite known associations between SBDH and diseases, SBDH factors are rarely investigated as interventions to improve patient outcomes. Gaining knowledge about SBDH and how SBDH data can be collected from EHRs using NLP approaches and predictive models improves the chances of influencing health policy change for patient wellness, ultimately promoting health and health equity.
Virtual Recruitment Is Here to Stay: A Survey of ID Fellowship Program Directors and Matched Applicants Regarding Their 2020 Virtual Recruitment Experiences
Rockney, Danica, Benson, Constance A. , Blackburn, Brian G. , Chirch, Lisa M , Konold, Victoria , Luther, Vera , Razonable, Raymund R. , Tackett, Sean , Melia, Michael T. , Razonable, Raymund R , Luther, Vera P

Open Forum Infectious Diseases | August 2, 2021 | Volume: 8 | Issue: 8 | Pages: No page available

10.1093/ofid/ofab383 | PMID 34395715 Get It

Abstract Background Graduate Medical Education training programs transitioned to all-virtual recruitment in 2020. Limited data have been published regarding the consequences of this transition. We aimed to understand (1) infectious diseases (ID) fellowship programs’ recruitment efforts and the effect of virtual recruitment on application and interview numbers and (2) the number of programs to which matched applicants applied and interviewed and applicants’ perspectives on virtual recruitment. Methods In 2020–2021, we surveyed all US ID fellowship program directors (PDs) and matched applicants. Descriptive data analysis was performed on quantitative survey items. Free-text responses were analyzed through a quantitative content analysis approach. Results The PD response rate was 68/158 (43%); the applicant response rate was at least 23% (85/365). PDs reported a 27% increase in mean number of applications received and a 45% increase in mean number of applicants interviewed compared with the previous year. Applicants especially valued the online program structure information, PD program overview videos, didactic and curriculum content, and fellow testimonials and profiles. Most applicants preferred interviews lasting no more than 40 minutes and interview days lasting no more than 5 hours. Nearly all (60/64, 94%) PDs adequately learned about candidates; most (48/64, 75%) felt unable to showcase their program as well as when in-person. Most PDs (54/64, 84%) and applicants (56/73, 77%) want an option for virtual recruitment. Conclusions Virtual recruitment enabled programs to accommodate more applicants and highlighted applicants’ preferences for programs’ augmented online presences and time-limited interview days. Most programs and applicants want an option for virtual interviews.
Impact of geography on prognostic outcomes of 21,509 patients with metastatic colorectal cancer enrolled in clinical trials: an ARCAD database analysis
Yin, Jun , Dawood, Shaheenah , Cohen, Romain , Meyers, Jeff, Zalcberg, John , Seymour, Michel , Maughan, Tim , Schmoll, Hans‐Joachim , Goldberg, Richard M. , Hoff, Paulo M. , Hecht, J. Randolph , Hurwitz, Herbert I. , Punt, Cornelis J.A. , Rubio, Eduard Diaz, Koopman, Miriam , Cremolini, Chiara , Heinemann, Volker , Tournigard, Christophe, Bokemeyer, Carsten , Fuchs, Charles S. , Souglakos, John , Doulliard, Jean-Yves, Kabbinavar, Fairooz F. , Chibaudel, Benoist , Gramont, Aimery de , Shi, Qian , Adams, Richard , Adams, Richard , Shi, Qian , Maughan, Timothy S , Seymour, Matthew T , Zalcberg, John , Schmoll, Hans-Joachim , Cremolini, Chiara , Chibaudel, Benoist , Cohen, Romain , Yoshino, Takayuki , Saltz, Leonard B. , Cutsem, Eric Van , Venook, Alan P. , Rubio, Eduard Diaz, Tebbutt, Niall C. , Grothey, Axel

Therapeutic Advances in Medical Oncology | June 30, 2021 | Volume: 13 | Issue: No issue available | Pages: No page available

10.1177/17588359211020547 | PMID 34262614 Get It

Background: Benchmarking international cancer survival differences is necessary to evaluate and improve healthcare systems. Our aim was to assess the potential regional differences in outcomes among patients with metastatic colorectal cancer (mCRC) participating in international randomized clinical trials (RCTs). Design: Countries were grouped into 11 regions according to the World Health Organization and the EUROCARE model. Meta-analyses based on individual patient data were used to synthesize data across studies and regions and to conduct comparisons for outcomes in a two-stage random-effects model after adjusting for age, sex, performance status, and time period. We used mCRC patients enrolled in the first-line RCTs from the ARCAD database, which provided enrolling country information. There were 21,509 patients in 27 RCTs included across the 11 regions. Results: Main outcomes were overall survival (OS) and progression-free survival (PFS). Compared with other regions, patients from the United Kingdom (UK) and Ireland were proportionaly over-represented, older, with higher performance status, more frequently male, and more commonly not treated with biological therapies. Cohorts from central Europe and the United States (USA) had significantly longer OS compared with those from UK and Ireland ( p = 0.0034 and p < 0.001, respectively), with median difference of 3–4 months. The survival deficits in the UK and Ireland cohorts were, at most, 15% at 1 year. No evidence of a regional disparity was observed for PFS. Among those treated without biological therapies, patients from the UK and Ireland had shorter OS than central Europe patients ( p < 0.001). Conclusions: Significant international disparities in the OS of cohorts of mCRC patients enrolled in RCTs were found. Survival of mCRC patients included in RCTs was consistently lower in the UK and Ireland regions than in central Europe, southern Europe, and the USA, potentially attributed to greater overall population representation, delayed diagnosis, and reduced availability of therapies.
The alternative serotonin transporter promoter P2 impacts gene function in females with irritable bowel syndrome
Mohr, Sandra , Fritz, Nikola, Hammer, Christian , Martínez, Cristina , Berens, Sabrina , Schmitteckert, Stefanie , Wahl, Verena, Schmidt, Målin , Houghton, Lesley A. , Goebel‐Stengel, Miriam , Kabisch, Maria, Götze, Dorothea, Milovač, Irina , D’Amato, Mauro , Röth, Ralph , Mönnikes, Hubert, Engel, Felicitas , Gauss, Annika , Tesarz, Jonas , Raithel, Martin , Andresen, Viola , Frieling, Thomas , Pehl, Christian, Stein‐Thöringer, Christoph, Clarke, Gerard , Kennedy, Paul J. , Cryan, John F. , Spiller, Robert E. , Beltrán, Caroll J. , Madrid, Ana María , Torres, Verónica , Arce, Edith Pérez de , Herzog, Wolfgang , Sayuk, Gregory S. , Karamanolis, George, Pojskić, Lejla , Bustamante, Mariona , Rabionet, Raquel , Estivil, Xavier, Wouters, Mira M. , Rappold, Gudrun , Santos, Javier , Schaefert, Rainer , Niesler, Beate , Zheng, Tenghao , Engel, Felicitas , Gauss, Annika , Tesarz, Jonas , Raithel, Martin , Andresen, Viola , Frieling, Thomas , Keller, Jutta , Stein-Thöringer, Christoph , Clarke, Gerard , Kennedy, Paul J , Cryan, John F , Dinan, Timothy G , Quigley, Eamonn M M , Spiller, Robin , Madrid, Ana María , Pérez de Arce, Edith , Herzog, Wolfgang , Mayer, Emeran A , Sayuk, Gregory , Gazouli, Maria , Karamanolis, George , Kapur-Pojskič, Lejla , Bustamante, Mariona , Rabionet, Raquel , Estivil, Xavier , Franke, André , Lieb, Wolfgang , Boeckxstaens, Guy , Wouters, Mira M , Simrén, Magnus , Rappold, Gudrun A , Vicario, Maria , Santos, Javier , Schaefert, Rainer , Lorenzo-Bermejo, Justo , Niesler, Beate , D'Amato, Mauro , Houghton, L A , Martínez, Cristina , Zheng, Tenghao , Stein-Thöringer, Christoph K., Quigley, Eamonn M.M. , Torres, Verónica, Boeckxstaens, Guy E. , Simrén, Magnus , Bermejo, Justo Lorenzo

Journal of Cellular and Molecular Medicine | June 24, 2021 | Volume: 25 | Issue: 16 | Pages: 8047-8061

10.1111/jcmm.16736 | PMID 34165249 Get It

AbstractIrritable bowel syndrome (IBS) is a gut‐brain disorder in which symptoms are shaped by serotonin acting centrally and peripherally. The serotonin transporter gene SLC6A4 has been implicated in IBS pathophysiology, but the underlying genetic mechanisms remain unclear. We sequenced the alternative P2 promoter driving intestinal SLC6A4 expression and identified single nucleotide polymorphisms (SNPs) that were associated with IBS in a discovery sample. Identified SNPs built different haplotypes, and the tagging SNP rs2020938 seems to associate with constipation‐predominant IBS (IBS‐C) in females. rs2020938 validation was performed in 1978 additional IBS patients and 6,038 controls from eight countries. Meta‐analysis on data from 2,175 IBS patients and 6,128 controls confirmed the association with female IBS‐C. Expression analyses revealed that the P2 promoter drives SLC6A4 expression primarily in the small intestine. Gene reporter assays showed a functional impact of SNPs in the P2 region. In silico analysis of the polymorphic promoter indicated differential expression regulation. Further follow‐up revealed that the major allele of the tagging SNP rs2020938 correlates with differential SLC6A4 expression in the jejunum and with stool consistency, indicating functional relevance. Our data consolidate rs2020938 as a functional SNP associated with IBS‐C risk in females, underlining the relevance of SLC6A4 in IBS pathogenesis.
Clinicopathological and Molecular Characteristics of Early-Onset Stage III Colon Adenocarcinoma: An Analysis of the ACCENT Database
Jin, Zhaohui , Dixon, Jesse G. , Fiskum, Jack, Yothers, Greg , Allegra, Carmen J. , Haller, Daniel G. , Gramont, Aimery de , Taı̈eb, Julien , Tweleves, Christopher, Sadahiro, Sotaro , Blanke, Charles D. , Tomita, Naohiro , Seitz, Jean‐François, Erlichman, Charles , Yamanaka, Takeharu , Goldberg, Richard M. , George, Thomas J. , Fiskum, Jack M, Yothers, Greg , Haller, Daniel , Kerr, Rachel , Taieb, Julien , Twelves, Christopher , O'Connell, Michael, Saltz, Leonard , Marsoni, Silvia , André, Thierry , Mahipal, Amit , Goldberg, Richard M , George, Thomas J , Shi, Qian , Jin, Zhaohui , Dixon, Jesse G , Parekh, Hiral D. , Sinicrope, Frank A. , Wolmark, Norman , Schmoll, Hans‐Joachim , Kerr, Rachel , Cutsem, Eric Van , Twelves, Chris , O’Connell, Michael J. , Saltz, Leonard B. , Yoshino, Takayuki , Marsoni, Silvia , André, Thierry , Mahipal, Amit , Shi, Qian

JNCI: Journal of the National Cancer Institute | June 21, 2021 | Volume: 113 | Issue: 12 | Pages: 1693-1704

10.1093/jnci/djab123 | PMID 34405233 Get It

Abstract Background Colon cancer (CC) incidence in young adults (age 20-49 years), termed early-onset CC (EO-CC), is increasing. Methods Individual patient data on 35 713 subjects with stage III colon cancer from 25 randomized studies in the Adjuvant Colon Cancer ENdpoint database were pooled. The distributions of demographics, clinicopathological features, biomarker status, and outcome data were summarized by age group. Overall survival, disease-free survival, time to recurrence, and survival after recurrence were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for sex, race, body mass index, performance status, disease stage, grade, risk group, number of lymph nodes examined, disease sidedness, and molecular markers. All statistical tests were 2-sided. Results Using a 5% difference between age groups as the clinically meaningful cutoff, patients with stage III EO-CC had similar sex, race, performance status, risk group, tumor sidedness, and T stage compared with patients with late-onset CC (age 50 years and older). EO-CC patients were less likely to be overweight (30.2% vs 36.2%) and more commonly had 12 or more lymph nodes resected (69.5% vs 58.7%). EO-CC tumors were more frequently mismatch repair deficient (16.4% vs 11.5%) and less likely to have BRAFV600E (5.6% vs 14.0%), suggesting a higher rate of Lynch syndrome in EO-CC. Patients with EO-CC had statistically significantly better overall survival (hazard ratio [HR] = 0.81, 95% confidence interval [CI] = 0.74 to 0.89; P &lt; .001), disease-free survival (HR = 0.91, 95% CI = 0.84 to 0.98; P = .01), and survival after recurrence (HR = 0.88, 95% CI = 0.80 to 0.97; P = .008) in the analysis without molecular markers; however, age at onset of CC lost its prognostic value when outcome was adjusted for molecular markers. Conclusion Tumor biology was found to be a more important prognostic factor than age of onset among stage III colon cancer patients in the Adjuvant Colon Cancer ENdpoint database.
Unilateral Denervation of the Diaphragm Muscle Increases Central Drive Only During Ventilatory Behaviors
Gill, Luther, Mantilla, Carlos B. , Sieck, Gary C.

The FASEB Journal | June 21, 2021 | Volume: 29 | Issue: S1 | Pages: No page available

10.1096/fasebj.29.1_supplement.1013.5 Get It

Compensatory respiratory plasticity is critical to preserve breathing capacity after phrenic denervation (DNV), when the contribution of the ipsilateral phrenic motor neuron (PhrMn) pool is abolished and the force generating capacity of the diaphragm muscle (DIAm) is compromised. In rats, ventilation is maintained after DNV, and this is most likely mediated by an increase in central drive to the contralateral PhrMn pool. The extent of central drive to PhrMns was estimated by measuring the root mean square (RMS) of DIAm EMG at 75ms (RMS 75 ) after the onset of activity. Transdiaphragmatic pressure (Pdi) was measured to estimate DIAm force. We hypothesized that after unilateral DNV central drive to the contralateral PhrMn pool increases across motor behaviors. Immediately following DNV, there was a significant increase in RMS 75 during ventilatory behaviors (eupnea, and hypoxia‐hypercapnia). RMS 75 did not change during non‐ventilatory behaviors (airway occlusion). These results indicate that after DNV there is: 1) an increase in central drive to the contralateral PhrMn pool during ventilatory behaviors such that Pdi was maintained; 2) central drive to the contralateral PhrMn pool was unchanged during more forceful (greater than ~50% Pdi max ) non‐ventilatory behaviors, suggesting that central drive was near maximum. These results highlight the compensatory plasticity in the neural control of the DIAm and the importance of measuring multiple motor behaviors.
Unilateral diaphragm muscle paralysis minimally impacts ventilation in rodents (871.5)
Gill, Luther, Jorgenson, Amy J., Medina, Juan Manuel Shiguetomi, Alvarez‐Argote, Juliana, Sieck, Gary C. , Gransee, Heather M. , Medina, Juan, Mantilla, Carlos B.

The FASEB Journal | June 16, 2021 | Volume: 28 | Issue: S1 | Pages: No page available

10.1096/fasebj.28.1_supplement.871.5 Get It

Ventilatory behaviors across a range of species including humans require less than 50% of maximal force‐generating capacity by the diaphragm muscle, the main inspiratory muscle in mammals. Near maximal forces are only generated during expulsive behaviors usually associated with airway clearance. There is ongoing controversy regarding the impact of unilateral lesions (e.g., spinal cord injury, denervation) on ventilatory outcomes. We hypothesized that unilateral denervation of the diaphragm muscle in rats and mice would minimally impact ventilation. Transdiaphragmatic pressure (Pdi) measurements were used to estimate diaphragm muscle force in adult male rats and mice. Following acute, unilateral phrenic nerve transection in the neck, there was no change in Pdi during eupnea or hypoxia‐hypercapnia in rats or mice. Reduced Pdi was evident during deep breaths and tracheal occlusion (behaviors associated with ~70% of maximal Pdi elicited by bilateral phrenic nerve stimulation) in both species. These results are also consistent with the lack of changes in tidal volume or respiratory pattern during eupnea measured by whole body plethysmography in unrestrained, spontaneously breathing rats after mid‐cervical contusion or hemisection injuries. These results highlight the large reserve capacity for force generation by the diaphragm muscle in rodents and the importance of measuring multiple motor behaviors. Grant Funding Source : Supported by HL096750, AG044615, HL105355 and Mayo Center for Regenerative Medicine