Safety and feasibility of irreversible electroporation for the pancreatic head in a porcine model.

BACKGROUND: Irreversible electroporation (IRE) is a local non-thermal ablative technique which has been suggested as a potential cancer therapy. However, the specific anatomic characteristics of the pancreatic head make it challenging to perform any local ablation in this region. Therefore, the safety and feasibility of IRE in the pancreatic head region should be further explored. AIM: To evaluate the safety of IRE in pancreatic head region including its effects on pancreatic ducts, vessels, and adjacent gastrointestinal organs. METHODS: Eight landrace miniature pigs underwent IRE of pancreatic head tissue successfully, with a total of 16 lesions created. Laboratory testing including white blood cell (WBC) count and serum amylase before IRE with follow-up laboratory analysis and pathological examination at 1, 7, 14, and 28 d postablation were performed. RESULTS: All pigs tolerated the ablation procedure without serious perioperative complications. Transiently elevated WBC count and amylase were observed at 24 h post-IRE, suggesting an acute pancreatic tissue damage which was confirmed by pathological observations. Vascular endothelial cells and pancreatic duct epithelial cells in ablation zone were also positive in terminal deoxynucleotidyl transferase dUTP nick end labeling staining. There was extensive duodenum mucosa damage with local hemorrhage 24 h after ablation, while regeneration of new villous structures were observed at 7 and 28 d post-IRE. Masson's trichromatic staining showed that the extracellular matrix was still intact in vessels and pancreatic ducts, and even in the duodenum. CONCLUSION: IRE ablation to the pancreatic head may be safe and feasible without long-term damage to the surrounding vital structures. However, risks of stress injuries in acute phase should be taken into consideration to prevent severe perioperative complications.

Evaluation of marginal adaptation of Co-Cr-Mo metal crowns fabricated by traditional method and computer-aided technologies.

BACKGROUND/PURPOSE: The purpose of this study was to evaluate the marginal gaps of dental restorations manufactured using conventional loss wax and casting, computer-aided design/computer-aided manufacturing (CAD/CAM), and 3D printing methods. MATERIALS AND METHODS: A zirconia master die model with an upper right first molar resin crown was prepared as a standardized model. A total of 30 resin master die models were duplicated from this standard model. Simultaneously, 10 Co-Cr-Mo metal crowns were individually obtained using the conventional loss wax and casting method (Group A), selective laser sintering (Group B), and CAD/CAM (Group C), respectively. The marginal gaps between the crowns fabricated conventional and digital methods with master die models were calculated using a 3D replica and mapping technique. RESULTS: Statistical analyses revealed there were significant differences in the marginal gaps in the group A with group B and C (p < 0.05). The mean marginal gaps between dental crowns with die models were 76 ±â€¯61 µm, 116 ±â€¯92 µm, and 121 ±â€¯98 µm for groups A, B, and C, respectively. CONCLUSION: Within the limitations of this study, the marginal gaps were clinical acceptable in conventional and digital techniques.

Low C6orf141 Expression is Significantly Associated with a Poor Prognosis in Patients with Oral Cancer.

C6orf141 (Chromosome 6 open reading frame 141) is a novel gene, and its role in oral cancer progression remains unclear. C6orf141 expression in oral squamous cell carcinoma (OSCC) and adjacent normal tissues from 428 patients was examined through immunohistochemistry (IHC). Our results revealed that C6orf141 expression was significantly reduced in OSCC compared with adjacent normal tissues. Low C6orf141 expression was significantly associated with a poor American Joint Committee on Cancer pathological stage (P < 0.001), T classification (P = 0.002), and pN stage (P = 0.032). Kaplan-Meier curves revealed that low C6orf141 expression was significantly associated with shorter disease-specific survival (DSS) in patients with OSCC (log-rank P = 0.007). Multivariate analysis indicated that low C6orf141 expression was an independent prognostic biomarker for DSS (adjusted hazard ratio = 1.34; 95% confidence interval = 1.10-1.81; P = 0.05). Additionally, ectopic C6orf141 expression could significantly suppress oral cancer cell proliferation, colony formation, and migratory and invasive abilities. Xenograft tumor growth assay revealed that C6orf141 could significantly suppress oral tumor growth in vivo. Our results suggest that C6orf141 plays a novel tumor-suppressive role in oral cancer cell growth and motility. Furthermore, C6orf141 dysfunction could be a potential prognostic biomarker for OSCC and provide new therapeutic strategies in the future.

Oxide layer characteristics and interfacial analysis of porcelain fused to high-gold alloy using multitechnique analysis methods.

BACKGROUND/PURPOSE: In a previous fractural study, high-gold crowns possessed the second highest fracture force. The objective of this study is to analyze the interface of porcelain fused to high-gold alloy using different observation devices. MATERIALS AND METHODS: High-gold crowns specimens with the morphology of a maxillary second premolar were compressed vertically in the center of the occlusal surface until fracture using a universal testing machine. The fractured surfaces were examined using scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM/EDX) to determine the failure mode. The ceramic-metal interface of the crown was examined with electron probe microanalysis (EPMA). In addition, sheet specimens with dimensions of 10 × 9 × 4 mm3 were prepared to examine the surface morphology and composition of high-gold alloy after oxidation using X-ray photoelectron spectrometer (XPS). RESULTS: The average fracture force was 1368 ± 312 N. Photograph of fractured crown and SEM/EDX analyses reveal that the crown initially suffered from cohesive failure in the upper and middle regions, with the fracture occurring mostly within the ceramic. XPS results and both EPMA color photomicrographs of crown and sheet specimens show that indium was observed along the porcelain-metal interface with a 1- to 2-µm disrupted zone of oxide layer. CONCLUSION: In2O3 and Au were found along the interface from the multitechnique analysis methods; the presence of this oxide at the boundary promotes ceramic-metal adhesion. In2O3 is suggested to be beneficial for the second highest fracture resistance in a previous fractural study of implant-supported crowns.

Jaw osteoradionecrosis and dental extraction after head and neck radiotherapy: A nationwide population-based retrospective study in Taiwan.

OBJECTIVES: Osteoradionecrosis of the jaws (ORNJ) is painful for patients and relatively difficult to treat clinically. The high risk of ORNJ for post radiotherapy R/T dental extraction is known; however, many patients still have to have teeth extracted after head and neck R/T. The objective of the present study is to review post R/T dental extraction and determine the ORNJ risk. MATERIALS AND METHODS: We preformed a retrospective cohort study of 1759 patients with head and neck cancer s/p R/T from a random sample of 1,000,000 insurants in the National Health Insurance Research Database during 2000-2013 in Taiwan. Statistical methods included two-proportion Z-test. RESULTS: We evaluated two cohorts: 522 patients with post R/T dental extraction and 1237 patients without post R/T extraction. Overall moderate-to-severe ORNJ after R/T was 2.22% (39/1759), and a total of 39 ORNJ cases were noted during an average of 3.02years (range: 0.62-8.89years, ±2.07). ORNJ prevalence in the overall post R/T extraction-exposed cohort (5.17%, 27/522) was significantly greater than that in the unexposed cohort (0.97%, 12/1237). In a group of patients with ⩽5 post R/T dental extractions (n=373), the ORNJ risk was 2.4% (ORNJ case n=9); in a group of patients with >5 dental extractions (n=149), the ORNJ risk was 12.1% (ORNJ case n=18) (Z-score=4.5062; p-value<0.0001). In the extraction-exposed cohort, the ORNJ risk is higher if the index day to first extraction day was ⩽0.5year (n=103) compared with the group with the index day to first extraction day >0.5year (n=419) (Z-score=-2.1506; p-value=0.0315). CONCLUSION: A tooth extraction time less than half a year after R/T or during the head and neck R/T period, and extraction tooth number ⩽5 would significant lower the ORNJ prevalence.

Therapeutic role of ultrasound-guided intranodal lymphangiography in refractory cervical chylous leakage after neck dissection: Report of a case and review of the literature.

BACKGROUND: Chylous leakage is a well-recognized but rare complication of head and neck surgery, affecting approximately 1% to 2.5% of head and neck dissections. It is a potentially life-threatening condition characterized by electrolyte imbalance, immunosuppression, delayed wound healing, risk of infection, and generalized sepsis. Management can be problematic and prolonged. METHODS: We present a case of refractory cervical chylous leakage after neck dissection treated with ultrasound-guided intranodal lymphangiography. RESULTS: Ultrasound-guided intranodal lymphangiography alone resulted in rapid and complete resolution of chylous leakage with minimal morbidity. CONCLUSION: Based on our clinical experience and after a thorough literature review, we propose that ultrasound-guided intranodal lymphangiography with contrast agent could be considered a viable therapeutic option for persistent chylous leakages in selected patients.

Interfacial analysis of porcelain fused to high-palladium alloy with different observation methods.

BACKGROUND/PURPOSE: In a previous fractural study of implant-supported crowns, it was found that the palladium-silver crowns possessed the highest fracture force. The ceramic-metal interface was examined to explain its high resistance to fracture. MATERIALS AND METHODS: Palladium-silver crowns with the morphology of a maxillary second premolar were prepared following standard dental laboratory procedures. Crown specimens were compressed vertically in the center of the occlusal surface until fracture, using a universal testing machine. The fractured surfaces were examined using scanning electron microscopy combined with energy dispersive X-ray spectroscopy to determine the failure mode. The ceramic-metal interface of the crown was examined with electron probe microanalysis. Additionally, sheet specimens with a dimension of 10 × 9 × 4 mm3 were prepared to examine the surface morphology and composition of palladium-silver alloy after oxidation and porcelain-fused-to-metal firing cycles. RESULTS: The average fracture force was 1425 ± 392N. Analyses with scanning electron microscopy combined with energy dispersive X-ray spectroscopy revealed that the failure mode was cohesive within the ceramic layer. Electron probe microanalysis micrographs indicated that Sn and In were found to distribute only on the alloy side of the ceramometal crown. Energy dispersive X-ray spectroscopy analysis and electron probe microanalysis micrographs confirmed that ZnO had diffused into the ceramic phase. CONCLUSION: In2O3, SnO2, and ZnO were found along the interface; the presence of these oxides at the boundary promotes ceramic-metal adhesion, and this resulted in cohesive failure of the ceramic layer. ZnO was found to diffuse into the ceramic phase, and it is suggested to be beneficial for high fracture resistance in the present study.

The Sternocleidomastoid Flap for Oral Cavity Reconstruction: Extended Indications and Technical Modifications.

PURPOSE: Several investigators have found that preserving the superior thyroid artery flap can considerably increase the survival rate of the sternocleidomastoid (SCM) flap. Nevertheless, they have recommended not cleaning the lymph nodes above level II for occipital artery preservation, which can leave risky metastatic lymph nodes and restrict the application of the SCM flap in patients with at least stage N1. The authors propose that preserving only the superior thyroid arteriovenous system is sufficient to ensure survival of the SCM flap and preserving the occipital artery is not necessary. They also propose preserving the cranial portion of the external jugular vein for improved venous return of the skin paddle. PATIENTS AND METHODS: This study retrospectively examined 20 patients with oral cancer (18 male, 2 female; 33 to 92 yr old; median age, 57.5 yr) who underwent SCM flap reconstruction from September 2011 to September 2014. All patients underwent surgical resection and immediate reconstruction with the SCM flap. The primary sites included the oral tongue border (n = 10), the base of the tongue (n = 3), the mandibular gingiva (n = 3), the floor of the mouth (n = 2), the buccal mucosa (n = 1), and the anterior neck skin (n = 1). RESULTS: The dimensions of the skin paddle ranged from 5 × 4 to 8 × 5 cm (length × width; mean, 6.7 × 4.2 cm). Arteriovenous type 1A1V of the superior thyroid arteriovenous system accounted for 30% of cases, 1A2V accounted for 30% of cases, 2A2V accounted for 25% of cases, 2A1V accounted for 5% of cases, 2A3V accounted for 5% of cases, and 3A2V accounted for 5% of cases. The mean number was 10.7 lymph nodes (standard deviation, 4.1 lymph nodes) per dissection above level II and 2 cases had level II lymph nodes metastasis. Only 1 case (5%) exhibited marginal loss of the skin paddle. The average operative time was 6.8 ± 0.9 hours and hospitalization was 12 ± 2.2 days. Follow-up ranged from 2 to 36 months. Two patients died of metastatic disease and 2 patients developed neck recurrences. CONCLUSIONS: Using the SCM flap with modifications is a reliable and convenient technique with wide application in the reconstruction of head and neck defects.