Mycotoxins as human carcinogens—the IARC Monographs classification

Abstract

Humans are constantly exposed to mycotoxins (e.g. aflatoxins, ochratoxins), mainly via food intake of plant and animal origin. The health risks stemming from mycotoxins may result from their toxicity, in particular their carcinogenicity. In order to prevent these risks, the International Agency for Research on Cancer (IARC) in Lyon (France)—through its IARC Monographs programme—has performed the carcinogenic hazard assessment of some mycotoxins in humans, on the basis of epidemiological data, studies of cancer in experimental animals and mechanistic studies. The present article summarizes the carcinogenic hazard assessments of those mycotoxins, especially aflatoxins (aflatoxin B₁, B₂, G₁, G₂ and M₁), fumonisins (fumonisin B₁ and B₂) and ochratoxin A (OTA). New information regarding the genotoxicity of OTA (formation of OTA-DNA adducts), the role of OTA in oxidative stress and the identification of epigenetic factors involved in OTA carcinogenesis–should they indeed provide strong evidence that OTA carcinogenicity is mediated by a mechanism that also operates in humans–could lead to the reclassification of OTA.

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Anatomical Study and Clinical Application of Facial Artery Perforator Flaps (FAPFs) in Intraoral Reconstruction: focusing on venous system

Publication date: Available online 26 November 2016
Source:Journal of Oral and Maxillofacial Surgery
Author(s): Wei-na Zhou, Lin-zhong Wan, Ping Zhang, Hua Yuan, Hong-bing Jiang, Yi-fei Du
ObjectiveFacial artery perforator flaps (FAPFs) were favored to repair intraoral and perinasal defects with convenient procedure and minimal donor-site morbidity. The purpose of this study was to investigate the anatomic features of FAPFs and presented its clinical application in intraoral reconstruction.Materials and MethodsFive cadaver specimens (10 sides) of head and neck regions and 90 clinical cases (90 sides) of neck dissection were analyzed to explore the facial venous drainage system of FAPFs. In addition, the anatomical features of facial artery and vein as well as marginal mandibular branch of facial nerve were investigated in cadaver specimens. Furthermore, the authors reviewed a series of 33 intraoral reconstruction cases using our designed FAPFs focusing on the flap survival and the types of facial venous drainage system.ResultsBased on cadaveric and clinical observation, facial vein drainage system could be divided into three types: type A drained into internal jugular vein (47%); type B drained into external jugular vein (37%); and type C drained into anterior jugular vein (16%). The mean distances between facial artery and vein at the region of FAPFs pedicle and tip were 2.79±0.51 mm and 10.24±0.70 mm, respectively. Most of the cases with our designed FAPFs obtained satisfactory aesthetic and functional outcomes, while three cases presented with venous congestion, all of which were encountered with type C facial vein drainage.ConclusionThis study improved the understanding of FAPFs anatomic features and clinical application in intraoral reconstruction. Our designed FAPFs could achieve a preferable intraoral defect reconstruction and type C facial vein drainage might be a risk factor to the flap survival.



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Clinical and Three-Dimensional Radiographic Evaluation of Autogenous Iliac Block Bone Grafting and Guided Bone Regeneration in Patients with Atrophic Maxilla

Publication date: Available online 26 November 2016
Source:Journal of Oral and Maxillofacial Surgery
Author(s): B. Alper Gultekin, Erol Cansiz, M. Oguz Borahan
PurposeTo evaluate the rate of graft resorption in autogenous iliac bone grafting (IBG) and guided bone regeneration (GBR) in patients with atrophic maxilla.MethodsThe investigators performed a retrospective study involving patients requiring implant placement who underwent IBG or GBR. Volumetric changes of the graft sites were evaluated by imaging studies. The primary predictor and outcome variables were augmentation technique and rate of volumetric resorption, respectively. Secondary outcome variables included bone gain, success of grafting, insertion torque of implants, and requirement for vestibuloplasty.ResultsThe sample comprised 39 patients (GBR, 21; IBG, 18). One patient each in the IBG and GBR groups experienced temporary sensory disturbance at donor site and late exposure of non-resorbable membrane, respectively. The average values of percent volume reduction of the GBR and IBG groups were 12.26 ± 2.35 and 35.94 ± 7.94 after healing and 15.87 ± 1.99 and 41.62 ± 6.97 at last follow-up, respectively. The IBG group exhibited significantly higher reduction in bone volume than the GBR group at both time points (P = 0.001). The mean values of horizontal and vertical bone gain after healing in the IBG group were significantly higher compared to those in the GBR group (P = 0.006 and 0.001, respectively). The mean implant torque during implant placement in the GBR group was significantly higher compared to that in the IBG group (P = 0.024). The was no significant difference in the requirement for vestibuloplasty between the two groups (P > .05).ConclusionsAlthough both hard tissue augmentation approaches provide adequate volume of bone graft for implant insertion, IBG results in greater graft resorption at maxillary augmented sites than GBR. Clinicians should consider the differences in extent of graft resorption between the two methods while choosing the treatment approach.



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Evaluation of the oropharynx in class I and II skeletal patterns by CBCT

Abstract

Purpose

This study aimed to evaluate the dimensions of the oropharynx and its shape in the minimum cross-sectional area, in individuals with Class I and Class II skeletal patterns, using three-dimensional CBCT images.

Methods

Forty-two cone-beam computed tomography images of grown individuals were evaluated. The images were divided according to the patient's skeletal patterns. The dimensions of the oropharyngeal airway space were determined using the Dolphin Imaging software.

Results

The volume and the minimum cross-sectional area were greater in patients with a Class I skeletal pattern, with a median difference of 5379 mm³ and 86.8 mm², respectively. The anteroposterior and lateral diameters in the minimum cross-sectional area were also higher in Class I individuals (2.3 and 6.0 mm, respectively), but the ratio between them was not different.

Conclusions

The volume and the minimum cross-sectional area of the oropharynx, as well as the anteroposterior and lateral diameters, are lower in individuals with a class II skeletal pattern than in individuals with a class I skeletal pattern. There was no difference in the shape of the oropharynx in healthy individuals with different skeletal patterns.

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The origin of DCs and capacity for immunologic tolerance in central and peripheral tissues

Abstract

Dendritic cells (DCs) are specialized immune sentinels that play key role in maintaining immune homeostasis by efficiently regulating the delicate balance between protective immunity and tolerance to self. Although DCs respond to maturation signals present in the surrounding milieu, multiple layers of suppression also co-exist that reduce the infringement of tolerance against self-antigens. These tolerance inducing properties of DCs are governed by their origin and a range of other factors including distribution, cytokines, growth factors, and transcriptional programing, that collectively impart suppressive functions to these cells. DCs directing tolerance secrete anti-inflammatory cytokines and induce naïve T cells or B cells to differentiate into regulatory T cells (Tregs) or B cells. In this review, we provide a detailed outlook on the molecular mechanisms that induce functional specialization to govern central or peripheral tolerance. The tolerance-inducing nature of DCs can be exploited to overcome autoimmunity and rejection in graft transplantation.

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Dendritic cells in central nervous system autoimmunity

Abstract

Dendritic cells (DCs) operate at the intersection of the innate and adaptive immune systems. DCs can promote or inhibit adaptive immune responses against neuroantigens. While DC intrinsic properties, i.e., their maturation state or the subset they belong to, are important determinants of the outcome of an autoimmune reaction, tissue-specific cues might also be relevant for the function of DCs. Thus, a better understanding of the performance of distinct DC subsets in specific anatomical niches, not only in lymphoid tissue but also in non-lymphoid tissues such as the meninges, the choroid plexus, and the inflamed CNS parenchyma, will be instrumental for the design of immune intervention strategies to chronic inflammatory diseases that do not put at risk basic surveillance functions of the immune system in the CNS. Here, we will review modern concepts of DC biology in steady state and during autoimmune neuroinflammation.

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Repair of complex pharyngocutaneous fistula using a staged temporoparietal fascial flap

Publication date: Available online 25 November 2016
Source:American Journal of Otolaryngology
Author(s): Nicholas B. Abt, Priya Srikanth, Sidharth V. Puram, Daniel G. Deschler
IntroductionPCF is the most common major complication after salvage total laryngectomy (TL), especially for previously irradiated patients with laryngeal or hypopharyngeal cancer.Methods/resultsA 65-year-old woman presented with recurrent bilateral supraglottic SCC requiring salvage TL 5.5years after initial T1N0M0 epiglottic SCC resection. Her post-operative course was complicated by PCF development one month post-operatively and surgical fistula closure was delayed for adjuvant chemoradiotherapy. The fistula persisted despite local wound therapy, several primary closures, pectoralis flap reconstruction with multiple revisions, and extensive hyperbaric oxygen treatments. Given her prior history, she underwent a staged right temporoparietal fascial flap reconstruction for persistent complex fistula, with second-stage flap takedown and complete inset of the TPFF skin island into the PCF.ConclusionThis case demonstrates the utility of staged TPFF in complex PCF repair, with minimal morbidity, especially in a patient with prior irradiation and flap use that complicates tissue availability.



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