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1430 citation(s) found for "Qi, Nathan".

Physical Resilience as a Determinant of Healthspan and Lifespan in Mice
LeBrasseur, Nathan K.

Innovation in Aging | December 18, 2020 | Volume: 4 | Issue: Supplement_1 | Pages: 829-829

10.1093/geroni/igaa057.3031 Get It

Abstract Dynamic measures of physical resilience—the ability to resist and recover from a challenge—may be informative of biological age far prior to overt manifestations such as age-related diseases and geriatric syndromes (i.e., frailty). If true, physical resilience at younger or middle ages may be predictive of future healthspan and lifespan, and provide a unique paradigm in which interventions targeting the fundamental biology of aging can be tested. This seminar will discuss research on the development of clinically-relevant measures of physical resilience in mice, including anesthesia, surgery, and cytotoxic drugs. It will further highlight how these measures compare between young, middle-aged, and older mice, and how mid-life resilience relates to later-life healthspan. Finally, it will provide insight into whether interventions targeting the biology of aging can modify physical resilience in mice. Part of a symposium sponsored by Epidemiology of Aging Interest Group.
HIP MUSCLE INHIBITION AFTER HIP ARTHROSCOPY: A ROLE FOR NEUROMUSCULAR ELECTRICAL STIMULATION
Mumbleau, Allison M., Schilaty, Nathan D. , Schilaty, Nathan D , Hewett, Timothy E.

International Journal of Sports Physical Therapy | December 18, 2020 | Volume: 15 | Issue: 6 | Pages: 1222-1228

10.26603/ijspt20201222 | PMID 33344037 Get It

Spontaneous Formation of Melanin from Dopamine in the Presence of Iron
Hedges, David M. , Yorgason, Jordan T. , Perez, Andrew W., Schilaty, Nathan D. , Williams, Benjamin M. , Watt, Richard K. , Steffensen, Scott C. , Schilaty, Nathan D , Yorgason, Jordan T , Steffensen, Scott C , Perez, Andrew W.

Antioxidants | December 16, 2020 | Volume: 9 | Issue: 12 | Pages: 1285

10.3390/antiox9121285 | PMID 33339254 Get It

Parkinson’s disease is associated with degeneration of neuromelanin (NM)-containing substantia nigra dopamine (DA) neurons and subsequent decreases in striatal DA transmission. Dopamine spontaneously forms a melanin through a process called melanogenesis. The present study examines conditions that promote/prevent DA melanogenesis. The kinetics, intermediates, and products of DA conversion to melanin in vitro, and DA melanogenesis under varying levels of Fe3+, pro-oxidants, and antioxidants were examined. The rate of melanogenesis for DA was substantially greater than related catecholamines norepinephrine and epinephrine and their precursor amino acids tyrosine and l-Dopa as measured by UV-IR spectrophotometry. Dopamine melanogenesis was concentration dependent on the pro-oxidant species and Fe3+. Melanogenesis was enhanced by the pro-oxidant hydrogen peroxide (EC50 = 500 μM) and decreased by the antioxidants ascorbate (IC50 = 10 μM) and glutathione (GSH; IC50 = 5 μM). Spectrophotometric results were corroborated by tuning a fast-scan cyclic voltammetry system to monitor DA melanogenesis. Evoked DA release in striatal brain slices resulted in NM formation that was prevented by GSH. These findings suggest that DA melanogenesis occurs spontaneously under physiologically-relevant conditions of oxidative stress and that NM may act as a marker of past exposure to oxidative stress.
Nelarabine-Induced Myelotoxicity
Carr, Carrie M. , Staff, Nathan P. , Naddaf, Elie , Madhavan, Ajay A. , Carr, Carrie M , Naddaf, Elie , Staff, Nathan P , Alkhateeb, Hassan B.

Neurology | December 11, 2020 | Volume: 96 | Issue: 4 | Pages: 175-176

10.1212/wnl.0000000000011343 | PMID 33310877 Get It

Stereotactic radiosurgery with versus without prior Onyx embolization for brain arteriovenous malformations
Ding, Dale , Lee, Cheng‐Chia , Kearns, Kathryn N. , Pomeraniec, I. Jonathan , Cifarelli, Christopher P. , Arsanious, David, Liščák, Roman , Hanuška, Jaromír, Woo, Shiao Y. , Ironside, Natasha , Burke, Rebecca M. , Warnick, Ronald E. , Mathieu, David , Mureb, Monica , Benjamin, Carolina , Feliciano, Caleb , Rodríguez‐Mercado, Rafael, Cockroft, Kevin M. , Simon, Scott D. , Mackley, Heath B., Zammar, Samer G. , Patel, Neel, Padmanaban, Varun , Beatson, Nathan, Saylany, Anissa , Lee, John Y. K. , Sheehan, Jason P. , _, _, May, Jaromír , Ding, Dale , Mathieu, David , Chen, Ching‐Jen , Williams, Brian J. , Yusuf, Mehran Behruj , Trifiletti, Daniel M. , Kondziolka, Douglas , _, _

Journal of Neurosurgery | December 11, 2020 | Volume: 135 | Issue: 3 | Pages: 742-750

10.3171/2020.7.jns201731 | PMID 33307527 Get It

OBJECTIVE Investigations of the combined effects of neoadjuvant Onyx embolization and stereotactic radiosurgery (SRS) on brain arteriovenous malformations (AVMs) have not accounted for initial angioarchitectural features prior to neuroendovascular intervention. The aim of this retrospective, multicenter matched cohort study is to compare the outcomes of SRS with versus without upfront Onyx embolization for AVMs using de novo characteristics of the preembolized nidus. METHODS The International Radiosurgery Research Foundation AVM databases from 1987 to 2018 were retrospectively reviewed. Patients were categorized based on AVM treatment approach into Onyx embolization (OE) and SRS (OE+SRS) or SRS alone (SRS-only) cohorts and then propensity score matched in a 1:1 ratio. The primary outcome was AVM obliteration. Secondary outcomes were post-SRS hemorrhage, all-cause mortality, radiological and symptomatic radiation-induced changes (RICs), and cyst formation. Comparisons were analyzed using crude rates and cumulative probabilities adjusted for competing risk of death. RESULTS The matched OE+SRS and SRS-only cohorts each comprised 53 patients. Crude rates (37.7% vs 47.2% for the OE+SRS vs SRS-only cohorts, respectively; OR 0.679, p = 0.327) and cumulative probabilities at 3, 4, 5, and 6 years (33.7%, 44.1%, 57.5%, and 65.7% for the OE+SRS cohort vs 34.8%, 45.5%, 59.0%, and 67.1% for the SRS-only cohort, respectively; subhazard ratio 0.961, p = 0.896) of AVM obliteration were similar between the matched cohorts. The secondary outcomes of the matched cohorts were also similar. Asymptomatic and symptomatic embolization-related complication rates in the matched OE+SRS cohort were 18.9% and 9.4%, respectively. CONCLUSIONS Pre-SRS AVM embolization with Onyx does not appear to negatively influence outcomes after SRS. These analyses, based on de novo nidal characteristics, thereby refute previous studies that found detrimental effects of Onyx embolization on SRS-induced AVM obliteration. However, given the risks incurred by nidal embolization using Onyx, this neoadjuvant intervention should be used judiciously in multimodal treatment strategies involving SRS for appropriately selected large-volume or angioarchitecturally high-risk AVMs.
American Society of Clinical Oncology Road to Recovery Report: Learning From the COVID-19 Experience to Improve Clinical Research and Cancer Care
Dillmon, Melissa S., Levit, Laura A. , Moushey, E. Allyn, Alva, Ajjai , Blau, Sibel , Dickson, Natalie R. , Gönen, Mithat , González, Maria Magdalena, Hensold, Jack O. , Hinyard, Leslie , King, Tari A. , Lindsey, Stacie , Magnuson, Allison , Marron, Jonathan M. , Mcaneny, Barbara , McDonnell, Theresa Margaret, Nasso, S, Nowakowski, Grzegorz S. , Oettel, Kurt R., Patel, Manali I. , Patt, Debra A. , Perlmutter, Jane , Pickard, Todd , Rodriguez, Gladys , Rosenberg, Abby R. , Russo, Barry, Szczepanek, Connie M. , Smith, Cardinale B. , Teplinsky, Eleonora , Thota, Ramya , Zoň, Robin , Bourbeau, Brian , Foster, Shelagh E., Grubbs, Stephen, Hagerty, Karen L., Hurley, Patricia A. , Kamin, Deborah Y., Phillips, Jonathan , Schilsky, Richard L. , Burris, Howard A. , Hurley, Patricia , Rosenberg, Abby R , Pennell, Nathan A , Cannon, Timothy Lewis , Diehn, Maximilian , Mileham, Kathryn Finch , Srivastava, Piyush, Traina, Tiffany A , Bruinooge, Suanna S. , Schenkel, Caroline

Journal of Clinical Oncology | December 8, 2020 | Volume: 39 | Issue: 2 | Pages: 155-169

10.1200/jco.20.02953 | PMID 33290128 Get It

This report presents the American Society of Clinical Oncology’s (ASCO’s) evaluation of the adaptations in care delivery, research operations, and regulatory oversight made in response to the coronavirus pandemic and presents recommendations for moving forward as the pandemic recedes. ASCO organized its recommendations for clinical research around five goals to ensure lessons learned from the COVID-19 experience are used to craft a more equitable, accessible, and efficient clinical research system that protects patient safety, ensures scientific integrity, and maintains data quality. The specific goals are: (1) ensure that clinical research is accessible, affordable, and equitable; (2) design more pragmatic and efficient clinical trials; (3) minimize administrative and regulatory burdens on research sites; (4) recruit, retain, and support a well-trained clinical research workforce; and (5) promote appropriate oversight and review of clinical trial conduct and results. Similarly, ASCO also organized its recommendations regarding cancer care delivery around five goals: (1) promote and protect equitable access to high-quality cancer care; (2) support safe delivery of high-quality cancer care; (3) advance policies to ensure oncology providers have sufficient resources to provide high-quality patient care; (4) recognize and address threats to clinician, provider, and patient well-being; and (5) improve patient access to high-quality cancer care via telemedicine. ASCO will work at all levels to advance the recommendations made in this report.
NCMP-28. BEVACIZUMAB ASSOCIATED INTRACEREBRAL HEMORRHAGE IN PATIENTS WITH PRIMARY CNS MALIGNANCY
Clarke, Nathan, Clarke, Nathan

Neuro-Oncology | December 4, 2020 | Volume: 22 | Issue: Supplement_2 | Pages: ii128-ii129

10.1093/neuonc/noaa215.539 Get It

Abstract The risk of intracranial hemorrhage (ICH) associated with the use of bevacizumab (BEV) has been a topic of several reviews in the literature, and is considered to be a potential adverse effect of BEV when used in patients with malignant glioma. We performed a single-center retrospective chart-review identifying glioma patients treated with BEV at our institution. 595 unique patients who received BEV with documented follow up were identified. Of these patients, 23 (3.9%) developed ICH within 12 weeks (five half-lives) of a BEV infusion (median 9 days post infusion, 1-24 days IQR). There was a trend towards statistical significance between dose administered and the incidence of hemorrhage (P=0.06), with all 23 hemorrhages occurring in patients treated with 10 mg/kg (n=21/490) per infusion or 15 mg/kg per infusion (n=2/35) (n=525, 88.2% of cohort). No patient on dosing regimens of 7.5 mg/kg (n=72) or 5 mg/kg per infusion (n=16) (n=88, 14.7% of cohort) developed ICH. Therapeutic anticoagulation and concomitant BEV therapy was observed in 103 (17%) patients with 10 patients (10/93, 9.7%) developing an ICH (n=10), at a rate significantly higher than in patients treated with bevacizumab alone (13/479, 2.6%) (p=0.0025). When hemorrhages occurred (with or without concomitant anticoagulation) they were associated with high morbidity and mortality (ECOG 3.54 versus 1.26, p = < 0.0001), with 12 patients (52%) suffering severe debility (n=2) or death (n=10). CONCLUSION: Bevacizumab associated intracerebral hemorrhages remain uncommon events, similar to the baseline rate of spontaneous hemorrhage associated with malignant glioma. We observed a trend towards significance with higher doses per infusion associated with an increased rate of intracerebral hemorrhage. The combination of anticoagulation and BEV appears to confer a greater risk of hemorrhage than BEV alone.
Precision Radiotherapy: Reduction in Radiation for Oropharyngeal Cancer in the 30 ROC Trial
Sherman, Eric J. , Pei, Xin , Grkovski, Milan , Paudyal, Ramesh , Katabi, Nora , Yamaguchi, Takafumi N. , Daniel, J. , Lee, Simon , Shah, Rachna , Ratnakumar, Abhirami , Salcedo, Adriana , Tsai, C. Jillian , McBride, Sean M. , Boyle, Jay, Singh, Bhuvanesh , Damerla, Rama Rao , Paula, Arnaud Da Cruz , Price, Katharine A. , Moore, Eric J. , García, Joaquín J. , Foote, Robert L. , Humm, John L. , Shukla‐Dave, Amita , Pfister, David G. , Lee, Nancy Y. , Pei, Xin , Grkovski, Milan , Paudyal, Ramesh , Yamaguchi, Takafumi N , Ma, Daniel , Shah, Rachna , Kumar, Rahul , Kuo, Fengshen , Ratnakumar, Abhirami , Tsai, Chiaojung J , Morris, Luc G T , Higginson, Daniel S , Price, Katharine, Moore, Eric J , Foote, Robert , Boutros, Paul C , Shukla-Dave, Amita , Riaz, Nadeem , Schöder, Heiko , Selenica, Pier , Kumar, Rahul , Kuo, Fengshen , Aleynick, Nathan , Brown, David N. , Zhang, Zhigang , Hatzoglou, Vaios , Liu, Lydia , Higginson, Daniel S. , Ho, Alan L. , Wong, Richard J. , Chan, Timothy An-thy , Powell, Simon N. , Boutros, Paul C. , Reis‐Filho, Jorge S. , Tsai, CJillian

JNCI: Journal of the National Cancer Institute | November 11, 2020 | Volume: 113 | Issue: 6 | Pages: 742-751

10.1093/jnci/djaa184 | PMID 33429428 Get It

Abstract Background Patients with human papillomavirus–related oropharyngeal cancers have excellent outcomes but experience clinically significant toxicities when treated with standard chemoradiotherapy (70 Gy). We hypothesized that functional imaging could identify patients who could be safely deescalated to 30 Gy of radiotherapy. Methods In 19 patients, pre- and intratreatment dynamic fluorine-18-labeled fluoromisonidazole positron emission tomography (PET) was used to assess tumor hypoxia. Patients without hypoxia at baseline or intratreatment received 30 Gy; patients with persistent hypoxia received 70 Gy. Neck dissection was performed at 4 months in deescalated patients to assess pathologic response. Magnetic resonance imaging (weekly), circulating plasma cell-free DNA, RNA-sequencing, and whole-genome sequencing (WGS) were performed to identify potential molecular determinants of response. Samples from an independent prospective study were obtained to reproduce molecular findings. All statistical tests were 2-sided. Results Fifteen of 19 patients had no hypoxia on baseline PET or resolution on intratreatment PET and were deescalated to 30 Gy. Of these 15 patients, 11 had a pathologic complete response. Two-year locoregional control and overall survival were 94.4% (95% confidence interval = 84.4% to 100%) and 94.7% (95% confidence interval = 85.2% to 100%), respectively. No acute grade 3 radiation–related toxicities were observed. Microenvironmental features on serial imaging correlated better with pathologic response than tumor burden metrics or circulating plasma cell-free DNA. A WGS-based DNA repair defect was associated with response (P = .02) and was reproduced in an independent cohort (P = .03). Conclusions Deescalation of radiotherapy to 30 Gy on the basis of intratreatment hypoxia imaging was feasible, safe, and associated with minimal toxicity. A DNA repair defect identified by WGS was predictive of response. Intratherapy personalization of chemoradiotherapy may facilitate marked deescalation of radiotherapy.
Intraoperative Hypotension Is Associated With Adverse Clinical Outcomes After Noncardiac Surgery
Gregory, Anne, Stapelfeldt, Wolf H. , Boero, Isabel J., Chen, Qinyu , Stevens, Mitali, Smischney, Nathan J. , Khanna, Ashish K. , Shaw, Andrew

Anesthesia & Analgesia | November 11, 2020 | Volume: 132 | Issue: 6 | Pages: 1654-1665

10.1213/ane.0000000000005250 | PMID 33177322 Get It

BACKGROUND: Intraoperative hypotension (IOH) occurs frequently during surgery and may be associated with organ ischemia; however, few multicenter studies report data regarding its associations with adverse postoperative outcomes across varying hemodynamic thresholds. Additionally, no study has evaluated the association between IOH exposure and adverse outcomes among patients by various age groups. METHODS: A multicenter retrospective cohort study was conducted between 2008 and 2017 using intraoperative blood pressure data from the US electronic health records database to examine postoperative outcomes. IOH was assessed in 368,222 noncardiac surgical procedures using 5 methods: (a) absolute maximum decrease in mean arterial pressure (MAP) during surgery, (b) time under each absolute threshold, (c) total area under each threshold, (d) time-weighted average MAP under each threshold, and (e) cumulative time under the prespecified relative MAP thresholds. MAP thresholds were defined by absolute limits (≤75, ≤65, ≤55 mm Hg) and by relative limits (20% and 40% lower than baseline). The primary outcome was major adverse cardiac or cerebrovascular events; secondary outcomes were all-cause 30- and 90-day mortality, 30-day acute myocardial injury, and 30-day acute ischemic stroke. Residual confounding was minimized by controlling for observable patient and surgical factors. In addition, we stratified patients into age subgroups (18–40, 41–50, 51–60, 61–70, 71–80, >80) to investigate how the association between hypotension and the likelihood of major adverse cardiac or cerebrovascular events and acute kidney injury differs in these age subgroups. RESULTS: IOH was common with at least 1 reading of MAP ≤75 mm Hg occurring in 39.5% (145,743) of cases; ≤65 mm Hg in 19.3% (70,938) of cases, and ≤55 mm Hg in 7.5% (27,473) of cases. IOH was significantly associated with the primary outcome for all age groups. For an absolute maximum decrease, the estimated odds of a major adverse cardiac or cerebrovascular events in the 30-day postsurgery was increased by 12% (95% confidence interval [CI], 11-14) for ≤75 mm Hg; 17.0% (95% CI, 15-19) for ≤65 mm Hg; and by 26.0% (95% CI, 22-29) for ≤55 mm Hg. CONCLUSIONS: IOH during noncardiac surgery is common and associated with increased 30-day major adverse cardiac or cerebrovascular events. This observation is magnified with increasing hypotension severity. The potentially avoidable nature of the hazard, and the extent of the exposed population, makes hypotension in the operating room a serious public health issue that should not be ignored for any age group.
Radiotherapy for malignant melanoma of the lacrimal sac
Cheng, Tiffany , Yu, Nathan Y. , Seetharam, ­Mahesh , Patel, Samir H. , Cheng, Tiffany W , Yu, Nathan

Rare Tumors | November 11, 2020 | Volume: 12 | Issue: No issue available | Pages: No page available

10.1177/2036361320971943 | PMID 33240474 Get It

Malignant melanoma of the lacrimal sac is an exceptionally rare tumor with a poor prognosis. We report two cases of malignant melanoma of the lacrimal sac: a 73 year-old female treated with primary surgical resection and a 75 year-old male treated with surgical resection, adjuvant proton beam radiotherapy, and adjuvant immunotherapy. We discuss the role of post-operative proton beam therapy and recent advancements in immunotherapy. These cases highlight the importance of early diagnosis and multi-modality treatment in this aggressive malignancy.