11 results on '"J. Christopher Fenno"'
Search Results
2. Increased Variance in Oral and Gastric Microbiome Correlates With Esophagectomy Anastomotic Leak
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J. Christopher Fenno, Brendan T. Heiden, Shari Barnett, Yvonne L. Kapila, Mark B. Orringer, William B. Weir, Andrew C. Chang, Philip W. Carrott, William R. Lynch, David G. Beer, Jules Lin, and Rishindra M. Reddy
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Male ,0301 basic medicine ,Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Leak ,Esophageal Mucosa ,Esophageal Neoplasms ,medicine.medical_treatment ,030106 microbiology ,Anastomotic Leak ,Adenocarcinoma ,Anastomosis ,Gastroenterology ,03 medical and health sciences ,Internal medicine ,medicine ,Carcinoma ,Humans ,Prospective Studies ,Prospective cohort study ,Aged ,Mouth ,business.industry ,Gastrointestinal Microbiome ,Middle Aged ,Esophageal cancer ,medicine.disease ,Esophagectomy ,030104 developmental biology ,Gastric Mucosa ,Carcinoma, Squamous Cell ,Female ,Surgery ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background Anastomotic leak after esophagectomy remains a significant source of morbidity and mortality. The gastrointestinal (GI) microbiome has been found to play a significant role in tumor oncogenesis and postoperative bowel anastomotic leak. We hypothesized that the GI microbiome could differentiate between esophageal cancer histologies and predict postoperative anastomotic leak. Methods A prospective study of esophagectomy patients was performed from May 2013 to August 2014, with the collection of oral saliva, intraoperative esophageal and gastric mucosa, and samples of postoperative infections (neck swab or sputum). The presence and level for each bacterial probe as end points were used to analyze correlations with tumor histology, tumor stage, and presence of postoperative complications by unequal variances t tests for multiple comparisons and principal coordinate analysis. Results Esophagectomy was successful in 55 of 66 patients who were enrolled. Among those, the diagnosis was adenocarcinoma in 44 (80%) squamous cell carcinoma in (13%), and benign disease in 4 (7%). The 30-day mortality was 1.8% (1 of 55). Complications included anastomotic leak requiring local drainage in 18% (10 of 55) and postoperative pneumonia in 2% (1 of 55). No correlation was noted between GI microbiome flora and tumor histology or tumor stage. A significant difference ( p = 0.015) was found when the variance in bacterial composition between the preoperative oral flora was compared with intraoperative gastric flora in patients who had a leak but not in patients with pneumonia. Conclusions Patients with anastomotic leaks had increased variance in their preoperative oral and gastric flora. Microbiome analysis could help identify patients at higher risk for leak after esophagectomy.
- Published
- 2018
3. High-purity Nisin Alone or in Combination with Sodium Hypochlorite Is Effective against Planktonic and Biofilm Populations of Enterococcus faecalis
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Guo-Hao Lin, J. Christopher Fenno, Jae M. Shin, Ruma Kajwadkar, Alexander H. Rickard, and Yvonne L. Kapila
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0301 basic medicine ,Sodium Hypochlorite ,030106 microbiology ,Enterococcus faecalis ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Bacteriocin ,Disk Diffusion Antimicrobial Tests ,polycyclic compounds ,General Dentistry ,Nisin ,Volume concentration ,Dose-Response Relationship, Drug ,biology ,Low dose ,Biofilm ,food and beverages ,030206 dentistry ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,Antimicrobial ,Anti-Bacterial Agents ,chemistry ,Biofilms ,Sodium hypochlorite ,bacteria ,Drug Therapy, Combination ,lipids (amino acids, peptides, and proteins) - Abstract
Introduction Nisin, a broad-spectrum bacteriocin, has recently been highlighted for its biomedical applications. To date, no studies have examined the antimicrobial and antibiofilm properties of high-purity (>95%) nisin (nisin ZP) on Enterococcus faecalis and biofilms formed by this species. We hypothesize that nisin can inhibit E. faecalis and reduce biofilm biomass, and combinations of nisin and sodium hypochlorite (NaOCl) will enhance the antibiofilm properties against E. faecalis biofilms. Methods Using broth cultures, disc diffusion assays, and biofilm assays, we examined the effects of nisin on various E. faecalis growth parameters and biofilm properties (biovolume, thickness, and roughness). Confocal microscopy was used in conjunction with Imaris and Comstat2 software (Kongens Lyngby, Copenhagen, Denmark) to measure and analyze the biofilm properties. Results Nisin significantly decreased the growth of planktonic E. faecalis dose dependently. The minimum inhibitory concentrations against E. faecalis strains OG-1 and ATCC 29212 were 15 and 50 μg/mL, and the minimum bactericidal concentrations were 150 and 200 μg/mL, respectively. A reduction in biofilm biovolume and thickness was observed for biofilms treated with nisin at ≥10 μg/mL for 10 minutes. In addition, the combination of nisin with low doses of NaOCl enhanced the antibiofilm properties of both antimicrobial agents. Conclusions Nisin alone or in combination with low concentrations of NaOCl reduces the planktonic growth of E. faecalis and disrupts E. faecalis biofilm structure. Our results suggest that nisin has potential as an adjunctive endodontic therapeutic agent and as an alternative to conventional NaOCl irrigation.
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- 2017
4. Collagen/fibrin microbeads as a delivery system for Ag-doped bioactive glass and DPSCs for potential applications in dentistry
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Blake McAlpin, Rameshwar R. Rao, Alexis W. Peterson, Li Zheng, Jan P. Stegemann, Petros Papagerakis, David J. Caldwell, Xanthippi Chatzistavrou, Yuanyuan Wang, and J. Christopher Fenno
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Materials science ,biology ,0206 medical engineering ,02 engineering and technology ,Microbead (research) ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,biology.organism_classification ,020601 biomedical engineering ,Streptococcus mutans ,Fibrin ,Enterococcus faecalis ,Electronic, Optical and Magnetic Materials ,law.invention ,Cell biology ,stomatognathic system ,law ,In vivo ,Dental pulp stem cells ,Bioactive glass ,Materials Chemistry ,Ceramics and Composites ,biology.protein ,Viability assay ,0210 nano-technology - Abstract
Silver doped bioactive glass (Ag-BG) and Dental Pulp Stem Cells (DPSCs) have shown promising properties for dental tissue regeneration. This study presents the fabrication and characterization of composite collagen/fibrin microbeads that aimed to incorporate and successfully deliver both Ag-BG and DPSC. Cell viability, cell differentiation in vitro and in vivo, and antibacterial properties of the systems against Escherichia coli ( E. coli ), Streptococcus mutans ( S. mutans ) and Enterococcus faecalis ( E. faecalis ) were evaluated. Cell viability and proliferation of DPSCs within the delivery system were found unaltered in both combinations (Beads/DPSCs and Beads/DPSCs/Ag-BG). Our results show that Ag-BG and DPSCs were successfully incorporated and proliferated within the collagen/fibrin microbeads. DPSCs continued to proliferate up to 6-weeks in cell culture but cell differentiation into odontoblast-like cells was observed only in vivo. The beads containing Ag-BG strongly inhibit bacterial growth in the experimental groups (beads alone, Beads/Ag-BG and Beads/DPSCs/Ag-BG). Our data suggests that collagen/fibrin microbead paste could have clinical applicability in the regenerative dentistry field.
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- 2016
5. Designing dental composites with bioactive and bactericidal properties
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Anna Lefkelidou, Toshihiro Kasuga, Kyle DiRenzo, Petros Papagerakis, Xanthippi Chatzistavrou, Aldo R. Boccaccini, J. Christopher Fenno, and Saalini Velamakanni
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Dental composite ,Ceramics ,Materials science ,Nanocomposite ,biology ,Bond strength ,Simulated body fluid ,Bioengineering ,biology.organism_classification ,Streptococcus mutans ,Apatite ,Anti-Bacterial Agents ,Nanocomposites ,law.invention ,Biomaterials ,Dental Materials ,Mechanics of Materials ,law ,Bioactive glass ,visual_art ,Escherichia coli ,visual_art.visual_art_medium ,Composite material ,Antibacterial activity - Abstract
Objectives The aim of this work was to fabricate and evaluate new antibacterial and bioactive composites capable of strictly controlling oral bacteria, enhancing apatite layer formation and retaining their mechanical properties. Methods A new Ag-doped bioactive glass (Ag-BG) was incorporated into flowable dental composite (COMP) in different concentrations (1, 5, and 15 wt.%) in order to fabricate new combined bioactive and antibacterial composite materials (Ag-BGCOMPs). The antibacterial properties, bioactivity, and total bond strength of the Ag-BGCOMPs were evaluated. Results The bioactivity of the Ag-BG was confirmed after its immersion in simulated body fluid (SBF). The total bond strength between the surrounding tooth tissue and the new composites or the control (dental composite alone) has not shown any statistically significant difference in the performed pilot study. Antibacterial activity was observed against Escherichia coli ( E. coli ) and Streptococcus mutans ( S. mutans ) for the Ag-BGCOMP 5 wt.% and 15 wt.% but not for the Ag-BGCOMP 1 wt.% or the control. Conclusions This work contributes to our long term aim which is the fabrication of dental materials capable of reducing bacteria invasion and enhancing remineralization of the surrounding dental tissues. Significance We anticipate that these new composites could ultimately prevent restoration failure by inhibiting the formation of secondary caries and by remineralizing the hard tissues surrounding tooth lesions.
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- 2015
6. Treponema denticola upregulates MMP-2 activation in periodontal ligament cells: Interplay between epigenetics and periodontal infection
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Xu Qian, Yvonne L. Kapila, Valentina Godovikova, Di Miao, Suchithra Seshadrinathan, and J. Christopher Fenno
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Matrix metalloproteinase ,Epigenesis, Genetic ,2.1 Biological and endogenous factors ,Aetiology ,Internalization ,Cells, Cultured ,Tissue homeostasis ,media_common ,Microscopy ,Cultured ,MMP-2 ,biology ,Blotting ,Treponema denticola ,Proteases ,General Medicine ,Up-Regulation ,Infectious Diseases ,DNA methylation ,Matrix Metalloproteinase 2 ,Epigenetics ,medicine.symptom ,Infection ,Western ,Biotechnology ,Transcriptional Activation ,Periodontal Ligament ,Cells ,media_common.quotation_subject ,Blotting, Western ,Inflammation ,Article ,Fluorescence ,Microbiology ,MT1/MMP ,TIMP-2 ,Genetic ,stomatognathic system ,Genetics ,medicine ,Humans ,Periodontal fiber ,Treponema ,Dental/Oral and Craniofacial Disease ,Periodontitis ,General Dentistry ,Tissue Inhibitor of Metalloproteinase-2 ,Cell Biology ,DNA Methylation ,medicine.disease ,biology.organism_classification ,stomatognathic diseases ,Microscopy, Fluorescence ,Otorhinolaryngology ,Dentistry ,Zoology ,Epigenesis - Abstract
Objective Periodontal pathogens initiate chronic dysregulation of inflammation and tissue homeostasis that characterize periodontal disease. To better understand oral microbe–host tissue interactions, we investigated expression and activation of MMP-2 in periodontal ligament cells following Treponema denticola challenge. Design Cultured PDL cells were challenged with T. denticola , and bacterial adherence, internalization and survival were assayed by immunofluorescence microscopy and antibiotic protection assays, respectively. MMP-2 activation was detected by zymography. MMP-2, MT1/MMP and TIMP-2 expression following T. denticola challenge was determined by qRT-PCR. Promoter methylation of MMP-2 and MT1/MMP was screened by methylation-sensitive restriction analysis and by bisulfite DNA sequencing. Results T. denticola adhered to and was internalized by PDL cells but did not survive intracellularly beyond 24 h. Importantly, while dentilisin activity in PDL culture supernatants gradually decreased following T. denticola challenge, MMP-2 activation persisted for up to 5 days, suggesting involvement of other regulatory mechanisms. Transcription and expression of MT1/MMP and TIMP-2 increased in response to T. denticola challenge. However, consistent with previously reported constitutive pro-MMP-2 expression in PDL cells, the MMP-2 promoter was hypomethylated, independent of T. denticola challenge. Conclusions MMP-2 promoter hypomethylation is consistent with constitutive pro-MMP-2 expression in PDL cells. This, coupled with T. denticola -mediated upregulation of MMP-2-related genes and chronic activation of pro-MMP-2, mimics key in vivo mechanisms of periodontal disease chronicity, in particular MMP-2-dependent matrix degradation and bone resorption. Adherence and/or internalization of T. denticola may contribute to these processes by one or more regulatory mechanisms, including contact-dependent signal transduction or other epigenetic mechanisms.
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- 2014
7. Fabrication and characterization of bioactive and antibacterial composites for dental applications
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Petros Papagerakis, Denver M. Faulk, J. Christopher Fenno, Toshihiro Kasuga, Stephen F. Badylak, Xanthippi Chatzistavrou, and Aldo R. Boccaccini
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Ceramics ,Silver ,Fabrication ,Materials science ,Cell Survival ,Swine ,Composite number ,Biomedical Engineering ,Bacterial Physiological Phenomena ,Biochemistry ,Enterococcus faecalis ,Buffer (optical fiber) ,law.invention ,Biomaterials ,Dental Materials ,law ,Materials Testing ,Zeta potential ,Animals ,Humans ,Ceramic ,Composite material ,Molecular Biology ,Cells, Cultured ,Dental Pulp ,Drug Implants ,Tooth regeneration ,biology ,General Medicine ,biology.organism_classification ,Anti-Bacterial Agents ,Extracellular Matrix ,Bioactive glass ,visual_art ,visual_art.visual_art_medium ,Biotechnology - Abstract
There is an increasing clinical need to design novel dental materials that combine regenerative and antibacterial properties. In this work the characterization of a recently developed sol-gel-derived bioactive glass ceramic containing silver ions (Ag-BG) is presented. The microstructural characteristics, ion release profile, zeta potential value and changes in weight loss and pH value as a function of the immersion time of Ag-BG in Tris buffer are evaluated. Ag-BG is also incorporated into natural extracellular matrix (ECM) hydrogel to further enhance its regenerative properties. Then, the micro and macro architectures of these new composites (ECM/Ag-BG) are characterized. In addition, the antibacterial properties of these new composites are tested against Escherichia coli and Enterococcus faecalis, a bacterium commonly implicated in the pathogenesis of dental pulp infections. Cell-material interaction is also monitored in a primary culture of dental pulp cells. Our study highlights the benefits of the successful incorporation of Ag in the bioactive glass, resulting in a stable antibacterial material with long-lasting bactericidal activity. Furthermore, this work presents for the first time the fabrication of new Ag-doped composite materials, with inductive pulp-cell proliferation and antibacterial properties (ECM/Ag-BG). This advanced composite made of Ag-BG incorporated into natural ECM possesses improved properties that may facilitate potential applications in tooth regeneration approaches.
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- 2014
8. A simplified erythromycin resistance cassette for Treponema denticola mutagenesis
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J. Christopher Fenno and M. Paula Goetting-Minesky
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Microbiology (medical) ,Mutagenesis (molecular biology technique) ,Erythromycin ,medicine.disease_cause ,Microbiology ,Article ,Bacterial Proteins ,stomatognathic system ,Drug Resistance, Bacterial ,medicine ,Molecular Biology ,Gene ,Escherichia coli ,Selectable marker ,Antibacterial agent ,Genetics ,biology ,Treponema denticola ,biology.organism_classification ,Anti-Bacterial Agents ,Mutagenesis, Insertional ,stomatognathic diseases ,Mutagenesis ,Bacteria ,medicine.drug - Abstract
The primary selectable marker for the genetic studies of Treponema denticola is a hybrid gene cassette containing both ermF and ermAM (ermB) genes. ErmB functions in Escherichia coli, while ErmF has been assumed to confer resistance in T. denticola. We demonstrate here that ErmB is sufficient for erythromycin selection in T. denticola and that the native ermB promoter drives ErmB expression.
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- 2010
9. Virulence Factors of Oral Treponemes
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J. Christopher Fenno and Barry C. McBride
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Genetics ,Infectious Diseases ,Virulence ,Biology ,Microbiology - Published
- 1998
10. Characterization of the unique complement resistance mechanisms of the periodontal pathogen, Treponema denticola: Insight into the survival strategies within the periodontal pocket
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M. Paula Goetting-Minesky, Richard T. Marconi, Daniel P. Miller, J. Christopher Fenno, John V. McDowel, and Jesse Frederick
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biology ,Gingival and periodontal pocket ,business.industry ,Complement resistance ,Immunology ,Survival strategy ,Medicine ,Treponema denticola ,biology.organism_classification ,business ,Molecular Biology ,Microbiology ,Periodontal pathogen - Published
- 2010
11. Analysis of the unique interaction of factor H with the periopathogen Treponema denticola: The paradox of factor H cleavage
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Richard T. Marconi, Daniel P. Miller, Jessica K. Bell, J. Christopher Fenno, and John J. McDowell
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biology ,Chemistry ,Stereochemistry ,Immunology ,Immunology and Allergy ,Treponema denticola ,Hematology ,Cleavage (embryo) ,biology.organism_classification - Published
- 2012
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