Surgical treatment of 61 consecutive patients with maxillary stage 3 medication-related osteonecrosis of the jaws using a pedicled buccal fat pad.

PURPOSE: Buccal fat pad (BFP) is used for the closure of large oroantral defects caused by surgical removal of the necrotic bone in patients with medication-related osteonecrosis of the jaw (MRONJ). This study aimed to evaluate the use of BFP for the closure of maxillary sinus defects in stage 3 MRONJ patients. METHODS: This study recruited 61patients with large oroantral defects caused by MRONJ, including 49 patients with cancer and 12 patients with osteoporosis. Lesions were evaluated clinically and radiographically. RESULTS: Among the 61 patients, 51 (83.6%) healed uneventfully, and 5 patients (8.2%) had local dehiscence and exposed bone; these 56 patients (91.8%) all healed after first or second operation. The Eastern Cooperative Oncology Group Performance Status was associated with being non-cured and might be an indicator for the healing process. All patients experienced a significant increase in body weight postoperatively. CONCLUSIONS: This study suggest that block resection with removal of the necrotic bone combined with radical sinusotomy and closure of the defect with BFP is a reliable method to cure MRONJ lesions with a high success rate, and successful operation and prosthetic rehabilitation may improve body weight and the quality of life. The study was approved by the appropriate ethical approval for the Copenhagen ONJ Cohort (protocol no. H-6-2013-010) November 20, 2013.

Stable Transfection of the Singlet Oxygen Photosensitizing Protein SOPP3: Examining Aspects of Intracellular Behavior.

Protein-encased chromophores that photosensitize the production of reactive oxygen species, ROS, have been the center of recent activity in studies of oxidative stress. One potential attribute of such systems is that the local environment surrounding the chromophore, and that determines the chromophore's photophysics, ideally remains constant and independent of the global environment into which the system is placed. Therefore, a protein-encased sensitizer localized in the mitochondria would arguably have the same photophysics as that protein-encased sensitizer at the plasma membrane, for example. One thus obtains a useful tool to study processes modulated by spatially localized ROS. One ROS of interest is singlet oxygen, O2 (a1 Δg ). We recently developed a singlet oxygen photosensitizing protein, SOPP, in which flavin mononucleotide, FMN, is encased in a re-engineered light-oxygen-voltage protein. One goal was to ascertain how a version of this system, SOPP3, which selectively makes O2 (a1 Δg ), in vitro, behaves in a cell. We now demonstrate that SOPP3 undergoes exacerbated irradiation-mediated bleaching when expressed at either the plasma membrane or mitochondria in stable cell lines. We find that the environment around the SOPP3 system affects the bleaching rate, which argues against one of the key suppositions in support of a protein-encased chromophore.

Phosphocholine-Decorated PPI-Dendrimers Mimic Cell Membrane Phosphocholine Clusters and Tune the Innate Immune Activity of C-Reactive Protein.

C-reactive protein (CRP) is widely used as biomarkers of infection and inflammation. It has a well-described ability to bind phosphocholine (PC), as well as PC-clusters from compromised and inflamed cell membranes and tissues. The binding of PC-clusters to CRP is of interest as this binding determines subsequent innate immune activity. We investigated PC-decorated dendrimers as mimics for PC-clusters. Five generations of poly(propylene imine) (PPI) dendrimers were modified with PC surface groups via a three-step synthetic sequence obtaining the PC-decorated dendrimers in high purity. The dendrimers were analyzed by NMR and infrared spectroscopy as well as HPLC. We developed immunoassays to show that dendrimer-PC binding to CRP was Ca2+-dependent with an apparent overall Kd of 11.9 nM for first generation (G1) PPI-PC, while G2-PPI-PC and G3-PPI-PC had slightly higher affinities, and G4-PPI-PC and G5-PPI-PC had slightly lower affinities. For all PC-dendrimers, the affinity was orders of magnitude higher than the affinity of free phosphocholine (PC), indicating a PC-cluster effect. Next, we investigated the binding of CRP:PPI-PC complexes to complement component C1q. C1q binding to CRP was dependent on the generation of PPI-PC bound to CRP, with second and third generation PPI-PCs leading to the highest affinity. The dendrimer-based approach to PC-cluster mimics and the simple binding assays presented here hold promise as tools to screen PC-compounds for their abilities to tune the innate immune activity of CRP.

A Fragment of Collagen Type VI alpha-3 chain is Elevated in Serum from Patients with Gastrointestinal Disorders.

Extracellular matrix (ECM) remodeling is a hallmark of the pathology of gastrointestinal disorders. Collagen type VI (COL6) is produced by fibroblasts, and the COL6 α3-chain has shown to be elevated in patients with ulcerative colitis (UC), Crohn's disease (CD) and colorectal cancer (CRC). Measuring COL6α3 in serum may therefore have potential as a biomarker for gastrointestinal disorders. The aims of this study were to develop and validate a competitive ELISA targeting a specific neo-epitope of COL6α3 and evaluate its associations with the gastrointestinal disorders UC, CD and CRC, in comparison to healthy controls. A monoclonal antibody was raised against a matrix metalloproteinase-2 and -9 specific cleavage site of COL6α3 (C6Mα3) and employed in a competitive enzyme-linked immunosorbent assay (ELISA). The assay was developed and technically validated. Levels of C6Mα3 were measured in serum from patients with UC (n = 58), CD (n = 44) and CRC (n = 39) and compared to healthy controls (n = 32). The levels of C6Mα3 were elevated in patients with UC, CD and CRC patients compared to healthy controls (all p < 0.0001). The area under the receiver operating characteristics (AUROC) curve for separation of patients with UC from healthy controls was 0.972 (95% CI: 0.925-1.020, p < 0.0001), with CD from healthy controls was 0.947 (95% CI: 0.885-1.009, p < 0.0001) and with CRC from healthy controls was 0.890 (95% CI: 0.809-0.972, p < 0.0001). We developed a technically robust assay targeting a fragment of COL6, which was elevated in serum from patients with UC, CD and CRC.

Interactions Between Thiopurine Metabolites, Adalimumab, and Antibodies Against Adalimumab in Previously Infliximab-Treated Patients with Inflammatory Bowel Disease.

BACKGROUND: Interactions between thiopurines and infliximab presumably contribute to superior effect of infliximab-thiopurine combination therapy in patients with inflammatory bowel disease (IBD). We examined whether principal cytotoxic thiopurine metabolites influence adalimumab (ADL) and anti-ADL antibodies (Abs). METHODS: Ninety-eight IBD patients previously treated with infliximab (96%) in whom trough ADL and anti-ADL Abs had been assessed as part of their clinical care were included. Thiopurine metabolites [6-thioguanine nucleotides (6-TGN) and methylated mercaptopurine metabolites (6-MeMP)] were determined at similar time points. RESULTS: ADL-thiopurine combination therapy was not associated with reduced anti-ADL Ab positivity compared to ADL monotherapy: 8/31 (26%) versus 19/67 (28%), p = 1.00. Concentrations of thiopurine metabolites were similar in anti-ADL Ab-positive and negative patients (6-TGN median 109 pmol/8 × 108 RBC vs. 112, p = 0.80; 6-MeMP 448 RBC vs. 720, p = 0.94). ADL trough levels did not differ between anti-ADL Ab-negative patients on ADL-thiopurine combination therapy and those on monotherapy (9.5 µg/mL vs. 7.6, p = 0.31). ADL levels were also comparable between patients on ADL mono- and combination therapy after stratification for 6-TGN/6-MeMP quartiles. There were no correlations between levels of 6-TGN and ADL (rP = - 0.17, p = 0.45; rS = - 0.38, p = 0.08), or 6-MeMP and ADL (rP = - 0.23, p = 0.31; rS = - 0.35, p = 0.11). Anti-ADL Ab positivity was associated with ADL treatment failure (OR 6 [2-20], p < 0.01). Higher trough ADL (9.6 µg/mL vs. 7.3, p < 0.05), but not concomitant thiopurine treatment, metabolite levels, or dosage, was associated with clinical remission. CONCLUSION: Effectiveness of ADL therapy associated with circulating ADL levels and anti-ADL Ab formation. In this study, there appeared no direct interactions between thiopurine metabolites and ADL or anti-ADL Abs.

A Role for Thiopurine Metabolites in the Synergism Between Thiopurines and Infliximab in Inflammatory Bowel Disease.

BACKGROUND: Interactions between principal cytotoxic thiopurine metabolites, that is 6-thioguanine nucleotides [6-TGN], and infliximab [IFX] and anti-IFX antibodies [Abs] may contribute to higher effectiveness of IFX-thiopurine combination therapy than monotherapies in inflammatory bowel disease. METHODS: To examine if thiopurine metabolites influenced trough IFX and anti-IFX Abs, 89 patients previously assessed for anti-IFX Abs were included. To assess if IFX influenced thiopurine metabolites, eight patients who had responded to 12 weeks of intensified IFX at a constant thiopurine dosing were included. RESULTS: In the first cohort, IFX-thiopurine combination therapy reduced anti-IFX Ab detection [8/40; 20%] as compared with IFX monotherapy [22/49; 45%], odds ratio [OR] 0.31 [0.12-0.80], p < 0.05. 6-TGN was significantly lower in anti-IFX Ab-positive patients (50 pmol/8 × 108 red blood cells [RBC] vs 105, p < 0.01). All anti-IFX Ab-positive patients had 6-TGN < 117 pmol/8 × 108 RBC (sensitivity 100% [63-100], specificity 47% [29-65], area under the curveROC = 0.82, p < 0.01). Trough IFX was similar between anti-IFX Ab-negative patients in IFX monotherapy and IFX-thiopurine combination therapy [5.1 µg/mL vs 4.9, p = 0.76]. 6-TGN and IFX did not correlate [rP = 0.04, p = 0.83; rS = 0.02, p = 0.89, respectively]. In the second cohort, trough IFX increased during IFX intensification [ΔIFX median 6.5 µg/mL, p = 0.02], but 6-TGN was stable [6-TGN at Weeks 0, 4, 8, 12: 90 pmol/8 × 108 RBC, 93, 101, 90; p > 0.05]. Methylated mercaptopurine metabolite associations were consistently negative. CONCLUSIONS: Superior effect of IFX-thiopurine combination therapy over monotherapies partly relates to decrease in anti-IFX Abs, which associates with 6-TGN levels and has a lower therapeutic threshold than during thiopurine monotherapy. Additional benefit likely ascribes to synergy between different anti-inflammatory modes of action rather than direct drug interactions.