Jeffrey Clymer

Dr. Jeffrey Clymer

orcid

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 2008 in American Journal of Respiratory and Critical Care Medicine
Verified
Journal Article
Closed access
DPDavid Proud
David Proud
RTRonald B. Turner
Ronald B. Turner
BWBirgit Winther
Birgit Winther
SWShahina Wiehler
Shahina Wiehler
JTJay P. Tiesman
Jay P. Tiesman
JCJeffrey Clymer
Jeffrey Clymer
Rationale: Human rhinovirus infections cause colds and trigger exacerbations of lower airway diseases. Objectives: To define changes in gene expression profiles during in vivo rhinovirus infections. Methods: Nasal epithelial scrapings were obtained before and during experimental rhinovirus infection, and gene expression was evaluated by microarray. Naturally acquired rhinovirus infections, cultured human epithelial cells, and short interfering RNA knockdown were used to further evaluate the role of viperin in rhinovirus infections. Measurements and Main Results: Symptom scores and viral titers were measured in subjects inoculated with rhinovirus or sham control, and changes in gene expression were assessed 8 and 48 hours after inoculation. Real-time reverse transcription-polymerase chain reaction for viperin and rhinoviruses was used in naturally acquired infections, and viperin mRNA levels and viral titers were measured in cultured cells. Rhinovirus-induced changes in gene expression were not observed 8 hours after viral infection, but 11,887 gene transcripts were significantly altered in scrapings obtained 2 days postinoculation. Major groups of up-regulated genes included chemokines, signaling molecules, interferon-responsive genes, and antivirals. Viperin expression was further examined and also was increased in naturally acquired rhinovirus infections, as well as in cultured human epithelial cells infected with intact, but not replication-deficient, rhinovirus. Knockdown of viperin with short interfering RNA increased rhinovirus replication in infected epithelial cells. Conclusions: Rhinovirus infection significantly alters the expression of many genes associated with the immune response, including chemokines and antivirals. The data obtained provide insights into the host response to rhinovirus infection and identify potential novel targets for further evaluation.

1 August 2019 in OncoTargets and Therapy
Verified
Journal Article
Open access
MGMrudula B. Glassberg
Mrudula B. Glassberg
SGSudip Ghosh
Sudip Ghosh
JCJeffrey Clymer
Jeffrey Clymer
RQRana A. Qadeer
Rana A. Qadeer
NFNicole C. Ferko
Nicole C. Ferko
JAJoseph F. Amaral
Joseph F. Amaral
Percutaneous ablation techniques, including microwave ablation (MWA) and radiofrequency ablation (RFA), have become important minimally invasive treatment options for liver cancer. This systematic review compared MWA with RFA for treatment of liver cancer. The systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search of MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials was conducted for randomized and observational studies published from 2006 onwards. A random-effects model was used for meta-analyses and local tumor progression (LTP), technique efficacy, overall survival (OS), disease-free survival (DFS), intrahepatic de novo lesions (IDL), extrahepatic metastases (EHM), length of stay (LOS), and complications were analyzed. Subgroup and sensitivity analyses were also conducted. Of 1379 studies identified, 28 randomized and observational studies met inclusion criteria. The main analysis demonstrated that LTP was significantly reduced by 30% with MWA versus RFA (RR=0.70; P=0.02) (all studies) and by 45% with MWA versus RFA (RR=0.55; P=0.007) (randomized studies only). There were no significant differences between MWA and RFA for other efficacy and safety outcomes. Higher frequency (2450 MHz) and larger tumor size (≥2.5 cm) are amongst variables that may be associated with improved outcomes for MWA. Sensitivity analyses were generally congruent with the main results. MWA is at least as safe and effective as RFA for treating liver cancer and demonstrated significantly reduced LTP rates. Future studies should assess time and costs associated with these two treatment modalities.

10 June 2019 in World Journal of Surgical Oncology
Verified
Journal Article
Open access
PDF file
MGMrudula B. Glassberg
Mrudula B. Glassberg
SGSudip Ghosh
Sudip Ghosh
JCJeffrey Clymer
Jeffrey Clymer
GWGeorge W. J. Wright
George W. J. Wright
NFNicole Ferko
Nicole Ferko
JAJoseph F. Amaral
Joseph F. Amaral
Hepatic resection (HR) is the gold standard liver cancer treatment, but few patients are eligible due to comorbidities or tumor location. Microwave ablation (MWA) is an important complementary liver cancer treatment to HR. This systematic review compared MWA with HR for liver cancer treatment. A systematic search of MEDLINE, EMBASE, and CENTRAL was conducted for randomized and observational studies published from 2006 onwards. The primary outcome was local tumor recurrence (LTR), and a random effects model was used for meta-analyses. Of the 1845 studies identified, 1 randomized and 15 observational studies met the inclusion criteria. LTR was significantly increased with MWA versus HR (risk ratio (RR) = 2.49; P = 0.016). In secondary measures, HR provided significantly higher 3- and 5-year overall survival (RR = 0.94; P = 0.03 and RR = 0.88; P = 0.01, respectively) and 3-year disease-free survival (RR = 0.78; P = 0.009). MWA exhibited significantly shorter length of stay (weighted mean difference (WMD) = − 6.16 days; P < 0.001) and operative time (WMD = − 58.69 min; P < 0.001), less intraoperative blood loss (WMD = − 189.09 mL; P = 0.006), and fewer complications than HR (RR = 0.31; P < 0.001). When MWA was combined with HR and compared with either modality alone, complications and blood loss were significantly lower with the combination treatment; however, there were no differences in other outcomes. Subgroup and sensitivity analyses were generally aligned with the main results. MWA can be an effective and safe alternative to HR in patients/tumors that are not amenable to resection. More randomized and economic studies should be performed that compare the two treatments, especially to determine the target population that benefits most from MWA.

1 November 2017 in Medical Devices: Evidence and Research
Verified
Journal Article
Open access
PDF file
MMMelinda H MacDonald
Melinda H MacDonald
AWAllen Y Wang
Allen Y Wang
JCJeffrey Clymer
Jeffrey Clymer
RHRichard W Hutchinson
Richard W Hutchinson
RKRichard Kocharian
Richard Kocharian
Background: Usage of topical hemostatic agents in surgery is increasing, including use during minimally invasive procedures, and even for surgeries that have a low risk of bleeding complications. A novel product, Surgicel® Powder – Absorbable Hemostatic Powder (SP), made from oxidized regenerated cellulose (ORC) fabric, has been developed for adjunctive use in surgical procedures to assist in control of oozing bleeding over broad areas and where access could be difficult with a fabric ORC product. This study compares the new SP to other commercially available hemostatic powder products in two in vivo models. Methods: Hemostatic efficacy of SP was compared to two polysaccharide-based hemostats in a porcine liver punch biopsy model and to three polysaccharide-based hemostats and one non-regenerated oxidized cellulose hemostat in a porcine liver abrasion model. Primary outcomes measured were hemostatic efficacy, defined as hemostasis within 10 minutes of application, and time-to-hemostasis (TTH). Results: In the punch biopsy model, SP displayed significantly higher effective hemostasis rates than one of the polysaccharide hemostats (p=0.047) and faster TTH than both (p<0.001). In the liver abrasion model, SP had significantly higher effective hemostasis rates (p≤0.002) and faster TTH (p<0.001) than the other four hemostatic agents. The amount of powder applied within the ranges used did not appear to affect hemostatic efficacy. Conclusion: In both the liver punch biopsy model of mild to moderate bleeding and the liver abrasion model of mild but diffuse oozing, SP provided more effective hemostasis and faster TTH than other marketed hemostatic powders. The results from this in vivo study suggest that Surgicel Powder may be useful in clinical applications where control of oozing capillary, mild venous, and small arterial hemorrhage is required including bleeding in difficult-to-access locations.

29 June 2012 in British Journal Of Neurosurgery
Verified
Journal Article
Closed access
PDF file
CCChaoyang Chen
Chaoyang Chen
SKSrinivasu Kallakuri
Srinivasu Kallakuri
AVAnuja Vedpathak
Anuja Vedpathak
CCChandrasekhar Chimakurthy
Chandrasekhar Chimakurthy
JCJohn M. Cavanaugh
John M. Cavanaugh
PMPrasanna Malaviya
Prasanna Malaviya
Background. While the risks associated with the use of electrosurgery near nerves are well known, few studies have examined the neurophysiologic effects of application of the Harmonic Blade, an ultrasonic scalpel, in the vicinity of nerve fibres. This study sought to compare the sub-acute neurophysiologic effects of the Harmonic Blade and electrosurgery after incisions close to the sciatic nerve. Methods. Incisions were made in rats with the Harmonic Blade and electrosurgery at distances of 1, 2, 3 and 4 mm from the sciatic nerve. Sham surgery was also performed. The compound action potential, conduction velocity and calibrated nylon filament (von Frey hair, VFH) stimulating force were monitored for up to 3 hours after surgery. The sciatic nerve was assessed for inflammation via H&E staining and impaired axonal transport by β-APP immunohistochemistry. Results. Electrosurgery incisions produced a significantly greater decrease in compound action potential and conduction velocity, and increase in the VFH force than the Harmonic Blade over all time points and distances from the sciatic nerve. The Harmonic Blade was similar to sham surgery for the compound action potential and VFH force. Electrosurgery yielded significantly greater leukocyte infiltration than the Harmonic Blade and produced the highest levels of β-APP immunoreactive swellings. Conclusions. Incisions with electrosurgery in the range of 1–4 mm of the sciatic nerve caused substantial changes in neurophysiologic functioning and inflammation. In contrast, the Harmonic Blade was similar to sham surgery in the vicinity of the nerve, producing little observable acute trauma.

1 October 2015 in Thyroid Research
Verified
Journal Article
Open access
PDF file
HCHang Cheng
Hang Cheng
ISIreena Soleas
Ireena Soleas
NFNicole C. Ferko
Nicole C. Ferko
JCJeffrey Clymer
Jeffrey Clymer
JAJoseph F. Amaral
Joseph F. Amaral
Several meta-analyses have been performed comparing the use of a variety of ultrasonic devices in thyroidectomy to conventional procedures. These studies have shown the superiority of ultrasonic devices for most outcomes studied including faster operative time and less blood loss, and equivalent or better safety for recurrent laryngeal nerve paresis and hypocalcemia. The current work is the first to examine a single ultrasonic device specifically designed for thyroid surgery, the Harmonic Focus, in order to confirm its efficacy and safety in thyroidectomy. A comprehensive literature search without language restrictions was performed for randomized clinical trials comparing Harmonic Focus and conventional clamp, cut and tie in thyroidectomy. Outcome measures included operating time, blood loss, post-operative pain, length of hospital stay, hypocalcemia and recurrent laryngeal nerve paresis. Risk of bias was analyzed for all studies. Meta-analysis was performed using random effects models with the inverse-variance method for mean differences of continuous variables and the Mantel-Haenszel method for risk ratios of dichotomous variables. A total of 14 studies met the inclusion criteria. Harmonic Focus reduced operative time by 29 min, a 31 % decrease (p < 0.001), intra-operative blood loss by 45 ml (p < 0.001), post-operative pain (p < 0.001), length of hospital stay by 0.68 days (p = 0.005), drainage volume by 29 ml (p = 0.01), and occurrence of transient hypocalcemia by 40 % (p = 0.001). There were no significant differences between Harmonic Focus and conventional procedures in rate of persistent hypocalcemia, or rates of transient and persistent recurrent laryngeal nerve paresis. This is the first meta-analysis of Harmonic Focus in thyroid surgery. In agreement with meta-analyses previously performed on ultrasonic devices, use of the Harmonic Focus has been shown to be a more effective surgical procedure compared to conventional methods in thyroidectomy. The low occurrence of hypocalcemia and recurrent laryngeal nerve paresis confirms that Harmonic Focus can improve thyroidectomy efficiency without increasing the risk of complications.