Gingival neoplasms: a multicenter collaborative study of 888 patients in Brazil.

BACKGROUND: To evaluate the prevalence and clinicopathological features of a large series of gingival neoplasms in Brazil. MATERIAL AND METHODS:  All gingival benign and malignant neoplasms were retrieved from the records of six Oral Pathology Services in Brazil, during a 41-year period. Clinical and demographic data, clinical diagnosis, and histopathological data were collected from the patients' clinical charts. For statistical analysis, the chi-square, median test of independent samples and the U Mann-Whitney tests were used, considering a significance of 5%. RESULTS:  From 100,026 oral lesions, 888 (0.9%) were gingival neoplasms. There were 496 (55.9%) males, with a mean age of 54.2 years. Most cases (70.3%) were malignant neoplasms. Nodules (46.2%) and ulcers (38.9%) were the most common clinical appearance for benign and malignant neoplasms, respectively. Squamous cell carcinoma (55.6%) was the most common gingival neoplasm, followed by squamous cell papilloma (19.6%). In 69 (11.1%) malignant neoplasms, the lesions were clinically considered to be inflammatory or of infectious origin. Malignant neoplasms were more common in older men, appeared with larger size, and with a time of complaint shorter than benign neoplasms (p<0.001). CONCLUSIONS:  Benign and malignant tumors may appear as nodules in gingival tissue. In addition, malignant neoplasms, especially squamous cell carcinoma, should be considered in the differential diagnosis of persistent single gingival ulcers.

Genome-wide association study identifies novel risk loci for apical periodontitis.

Apical periodontitis (AP) is a common consequence of root canal infection leading to periapical bone resorption. Microbial and host genetic factors, and their interactions, have been shown to play a role in AP development and progression. Variations in a few genes have been reported in association with AP, however, the lack of genome-wide studies has hindered progress in understanding the mechanisms involved in AP. Here, we report the first genome-wide association study of AP in a well-characterized population. Male and female adults (n=932) presenting with deep caries with AP (cases) or without AP (controls) were included. Genotyping was performed using the Illumina Expanded Multi-Ethnic Genotyping Array. Single-variant association testing was performed adjusting for sex and five principal components. Subphenotype association testing, analyses of genetically regulated gene expression, polygenic risk score and phenome-wide association (PheWAS) analyses were also performed. Eight loci reached near-genome-wide significant association with AP (p < 5 x 10-6); gene-focused analyses replicated three previously reported associations (p < 8.9 x 10-5). Sex-specific and subphenotype analyses revealed additional significant associations with variants genome-wide. Functionally oriented gene-based analyses revealed eight genes significantly associated with AP (p < 5 x 10-5), and PheWAS analysis revealed 33 phecodes associated with AP risk score (p < 3.08 x 10-5). This study identified novel genes/loci contributing to AP and revealed specific contributions to AP risk in males and females. Importantly, we identified additional systemic conditions significantly associated with AP risk. Our findings provide strong evidence for host-mediated effects on AP susceptibility.

Quantitative MRI evaluation of bone marrow in sickle cell disease: relationship with haemolysis and clinical severity.

AIM: To evaluate bone marrow fat fraction using the Dixon technique (FFDix) of magnetic resonance imaging (MRI) as a potential biomarker of haemolysis and clinical severity in the overall assessment and follow-up of sickle cell disease (SCD) patients. MATERIAL AND METHODS: The present study was a cross-sectional study in which healthy individuals and SCD patients (matched for age, sex, and weight) were subjected to MRI of the lumbar spine and pelvis to quantify FFDix in the bone marrow using the Dixon technique. SCD severity was analysed by clinical and laboratory data, and an online calculator. A high degree of haemolysis was defined using the cut-off values haemoglobin (Hb) ≤10 g/dl, lactate dehydrogenase (LDH) ≥325 U/l, reticulocytes ≥3% and total bilirubin (TB) ≥1.2 mg/dl. Pearson's correlation, receiver operating characteristic (ROC) curve and binary logistic regression analysis were performed. RESULTS: Forty-eight SCD patients (26 homozygous: HbSS and 22 compound heterozygous: HbSC) and 48 healthy individuals participated in the study. FFDix was lower in SCD patients than in the control group, showing even lower values in the HbSS subtype and patients with a higher degree of haemolysis. HbSC patients with a higher degree of haemolysis using hydroxyurea (medium dosage 9.8 mg/kg/day) had lower FFDix. ROC curves and odds ratios for detecting patients with a higher degree of haemolysis at the different FFDix measurement sites demonstrated excellent performance: iliac bones (cut-off ≤16.75%, AUC = 0.824, p<0.001), femoral heads (cut-off ≤46.7%, AUC = 0.775, p=0.001), lumbar vertebrae (cut-off ≤7.8%, AUC = 0.755, p=0.002). CONCLUSION: Decreased FFDix is indicative of higher degree of haemolysis and SCD severity with great potential as a non-invasive biomarker contributing to the overall assessment and follow-up of SCD patients.

Postoperative Sensitivity of Composite Replacement of Amalgam Restoration: A Randomized Clinical Trial.

PURPOSE: This randomized clinical trial aimed to evaluate the postoperative sensitivity of different resin composite/adhesive materials, placed either by an incremental or bulk-fill technique in posterior resin composite replacement of amalgam restorations. METHODS AND MATERIALS: A total of 47 patients with good overall health and at least four class I or class II amalgam restorations to be replaced participated in this study. The characteristics of 188 cavities were registered and randomly restored using incremental (Z350XT, 3M) or bulk-fill (Filtek Bulk Fill, 3M; Sonic Fill, Kerr; and Opus Bulk Fill, FGM) technique. The postoperative sensitivity was assessed using a Visual Analog Scale (0-100) after 24 hours, 7 days, and 30 days. Pain scores were temporally analyzed using Friedman test followed by Dunn post hoc test (α=0.05). The frequency of tests was calculated according to the frequency and percentage of the McNemar test. RESULTS: The restorative technique and the bulk-fill system used did not affect the postoperative sensitivity, except for Filtek Bulk Fill group, which presented less postoperative sensitivity after 24 hours (p=0.037). Regardless of the restorative material, the postoperative sensitivity decreased after 24 hours, and no differences were found after 7 and 30 days. CONCLUSIONS: After 1 week, the filling technique and the bulk-fill system have no influence on the postoperative sensitivity.

Perivascular mast cells and expression of vascular endothelial growth factor, laminin-332 and matrix metalloproteinase-9 in human colorectal neoplasms.

INTRODUCTION AND AIMS: Colorectal cancer (CRC) is one of the most prevalent cancers worldwide, and significantly contributes to cancer-related deaths. Most cases arise from adenomatous polyps. Biomarkers currently play an important role in tumor progression. Our aim was to identify perivascular mast cells and analyze the expression of laminin-332, MMP-9, and VEGF in cases of adenoma and CRC in humans. MATERIALS AND METHODS: Patients were selected at the Coloproctology Service and samples were obtained through biopsies. Adenoma and CRC slides were examined, utilizing immunohistochemistry to detect molecules, and were processed, using 1% Alcian Blue (pH 0.5) for mast cell staining. RESULTS: Higher density of perivascular mast cells was observed in adenomas. Laminin-332 expression revealed basement membrane discontinuity associated with tumor invasion in CRC. MMP-9 immunostaining in adenoma was detected in glandular epithelium and lining epithelium, in areas close to the basement membrane, whereas in CRC, the enzyme was found in the cytoplasm of invasive clusters. VEGF expression was associated with cell atypia in adenoma and in areas of disorganization of the epithelium-connective tissue interface in CRC. VEGF has also been detected in endothelial cells from microvessels. CONCLUSIONS: We demonstrated the different patterns of perivascular mast cells and molecular expression in colorectal neoplasms. Those analyses favor the recognition of the predisposition to the disease, or its early stage, and have the potential to define the molecular profile of the lesions.

A DFT investigation of lithium adsorption on graphenes as a potential anode material in lithium-ion batteries.

We present a detailed study of the Li+ ion adsorption on two different hydrogenated carbon nanostructures, namely as pristine graphene (PG) and topologic Stone-Wales defective graphene (SWG) using the density functional theory (DFT). The studies are focused to analyze the structure-stability relationship with the estimated electronic and electrical properties for lithium-ion batteries (LIB) formed with an anode based on the Li/Li+#PG and Li/Li+#SWG systems. In addition, the electronic effects induced due to Li+ adsorption and the presence of SW defect on the graphene models were analyzed by the frontier molecular orbitals, ChelpG charges, Raman and UV-Vis spectra. It was verified that Li+ is more stably adsorbed on the edges on both graphene structures through an electrostatic interaction between cation and more negatively charged edges of nanostructures. TD-DFT calculations showed that the metallic nature of isolated graphene is disturbed after the adsorption of Li+, and this was demonstrated from the calculated HOMO-LUMO gap. The same Li+-Graphene geometries were optimized by introducing neutral charge in order to enable the calculation of ionization potentials. I was also found that such systems potentially contributed to the modeling of graphene-based anodes with reasonable electrical voltage responses estimated for a LIB. The simulation of Raman and UV-Vis spectra revealed significant variations in intensity and shifts the typical bands of graphene due to the presence of the Li+ ion that can contribute to point out new experiments to the spectroscopic characterization of these systems. Our results suggest that these carbon nanostructures are potential candidates for efficient applications in electrochemical systems, mainly dealing with LIB.

The efficacy of 8-hydroxyquinoline derivatives in controlling the fungus Ilyonectria liriodendri, the causative agent of black foot disease in grapevines.

AIM: The purpose of this study was to evaluate the in vitro and in vivo efficiency of derivatives of 8-Hydroxyquinoline (8HQ) in controlling the fungus Ilyonectria liriodendri. METHODS AND RESULTS: The in vitro tests consisted of assessing its susceptibility to the minimal inhibitory concentration (MIC) and the inhibition of mycelial growth. While the in vivo tests consisted of applying and assessing the most effective products for the protection of wounds, in both preventive + curative and curative forms. The MIC values for PH 151 (6·25 µg ml-1 ) showed better results when compared to the fungicides tebuconazole (>50 µg ml-1 ) and mancozeb (12·5 µg ml-1 for strain 176 and 25 µg ml-1 for strain 1117). PH 151 significantly inhibited mycelial growth, while mancozeb did not differ from the control. In in vivo tests, PH 151 again demonstrated excellent results in vitro, especially when applied preventively. CONCLUSIONS: The derivative of 8HQ PH 151 was effective in controlling the fungus I. liriodendri in vitro and proved to be a promising option for protecting wounds. SIGNIFICANCE AND IMPACT OF THE STUDY: This study points to the prospect of an effective and safe preventive antifungal product, which would enable the use of pesticides in vine culture to be reduced.

Sinonasal melanoma: a systematic review of the prognostic factors.

The objective was to evaluate the available published data on sinonasal melanoma and analyse its clinical features, treatment modalities, and prognostic factors. An electronic search was undertaken in March 2018 in multiple databases. Eligibility criteria included publications with sufficient clinical, histological, and immunohistochemical information to confirm the diagnosis. Seventy-three publications (439 cases) were included. The lesion was more prevalent in females than in males. There was a higher prevalence in the seventh and eighth decades of life. The lesions mainly presented as epistaxis and commonly involved the nasal cavity. Age (>67.6 years; P=0.0012), primary location (middle turbinate; P=0.0112), disease stage (advanced disease stage; P=0.0026), treatment (radiotherapy; P=0.0111), recurrence (recurrence presented; P=0.0137), and distant metastasis (distant metastasis presented; P=0.0011) were independently associated with a lower survival rate. Recurrence was significantly correlated with age (>67.6 years; P=0.0021), sex (males tended to present a higher recurrence rate than females; P=0.0051), disease stage (stages III and IV presented a higher recurrence rate than stages I and II; P=0.0331), and histological type (amelanotic lesions presented a higher index of recurrence than melanotic lesions; P=0.0095). In conclusion, sinonasal melanoma is a neoplasm with a poor prognosis, presenting a 30.69% possibility of survival after 5 years.

In vitro anthelmintic activity of Siparuna guianensis extract and essential oil against Strongyloides venezuelensis.

New therapeutic approaches are necessary to control strongyloidiasis due to the side effects of, and resistance to, currently available drugs thiabendazole, albendazole, and ivermectin. This study examined the anthelmintic properties of extracts and isolated compounds from Siparuna guianensis against Strongyloides venezuelensis eggs and larvae, using the egg hatching test (EHT) and larval motility test (LMT). Albendazole (0.025 mg/ml) and ivermectin (0.316 mg/ml) were used as the positive controls for the EHT and LMT assays, respectively. Strongyloides venezuelensis eggs or larvae (±50 specimens) were treated with ethanol extract (0.05-1.0 mg/ml), ethyl acetate and aqueous fractions (0.05-0.8 mg/ml), essential oil (0.2-1.0 mg/ml) and α-bisabolol (0.2-1.0 mg/ml) from S. guianensis, and analysed by optical microscopy after 48 h (EHT), or after 24, 48 and 72 h (LMT). All the tested compounds exhibited ovicidal activity equivalent to the positive control and changed the morphology of the eggs. The S. guianensis ethanol extract and aqueous fraction were as effective as the positive control. Phytochemical analysis of the ethanol extract and fractions revealed the presence of phenolic compounds, tannins and flavonoids. Therefore, S. guianensis is effective against S. venezuelensis eggs and larvae in vitro, and can be considered as a potential alternative treatment for strongyloidiasis.

Phenotype comparison among individuals with developmental delay/intellectual disability with or without genomic imbalances.

BACKGROUND: The chromosomal microarray analysis (CMA) is recommended as a first-tier test for individuals with developmental delay (DD)/intellectual disability (ID) and/or multiple congenital anomalies. However, owing to high costs, this technique is not widely performed for diagnostic purposes in several countries. The aim of this study was to identify clinical features that could favour the hypothesis of genomic imbalances (GIs) in individuals with DD/ID. METHODS: The sample consisted of 63 individuals, and all of them underwent a detailed evaluation by a clinical geneticist and were investigated by the CMA. They were divided into two groups. Group A composed of 20 individuals with pathogenic copy number variants (CNVs); and group B composed of 43 individuals with normal CMA results or variants of uncertain clinical significance (VUS). RESULTS: Pathogenic GIs were found in 20 cases (32%), including 11 individuals with an abnormal karyotype, VUS was found in five individuals (8%) and the results were normal in 38 individuals (60%). Major anomalies were found in 15/20 (75%) individuals in group A against 35/43 (81%) in group B. Dysmorphisms (≥5) were found in 17/20 (85%) in group A and 41/43 (95%) in group B. The most frequent major anomalies detected in group A were congenital heart disease, epilepsy and renal malformation; and in group B, they were malformations of central nervous system, congenital heart disease, microcephaly, epilepsy and hearing impairment. There was no significant statistical difference among the frequencies in groups A and B. CONCLUSIONS: Evidences point that every individual with DD/ID, with no specific clinical suspicion, should have screening for GIs as a first-tier test, regardless of the presence or absence of additional major anomalies or dysmorphisms. Future studies with a similar design would be helpful, especially in countries where the access to new technologies is still limited.

Virulence factors of Candida spp. obtained from blood cultures of patients with candidemia attended at tertiary hospitals in Northeast Brazil.

BACKGROUND: Yeasts of the Candida genus are one of the most common causes of bloodstream infections associated with high rates of morbidity and mortality, mainly affecting immunocompromised patients. We aimed to identify yeasts obtained from blood cultures of patients interned at tertiary hospitals in Brazil. METHODS: We evaluated some of the major virulence factors of Candida spp., including the ability to adhere to human buccal epithelial cells, biofilm formation, hemolytic and phospholipase activity. RESULTS: We analyzed 70 isolates of Candida spp. obtained from March 2011 and March 2015. Candida spp. showed different peculiarities in terms of expression of virulence factors evaluated in vitro. C. albicans strains were more adherent to HBEC than all the other Candida species. C. tropicalis strains were considered strong biofilm producers. Strains belonging to the C. parapsilosis species complex were able to produce hemolysins, while C. glabrata was also able to lyse erythrocytes and to produce phospholipase. CONCLUSION: These results suggest that Non-Candida albicans Candida species are also able to express virulence factors which play an important role in bloodstream infectious caused by these yeasts.

Bradyrhizobium and Pseudomonas strains obtained from coal-mining areas nodulate and promote the growth of Calopogonium muconoides plants used in the reclamation of degraded areas.

AIMS: The objective of this work was to isolate and characterize indigenous rhizobia from coal-mining areas able to efficiently nodulate and fix nitrogen in association with Calopogonium mucunoides (calopo). METHODS AND RESULTS: Isolation, authentication and morphological, biochemical and molecular characterization of the autochthonous rhizobia were performed and their symbiotic efficiency (SE) evaluated. Efficient rhizobial isolates suitable for the inoculation of calopo in coal-mining regions were obtained. A total of 30 isolates were obtained after nodulation authentication, of which five presented high SE with plant-growth promoting traits such as indole-3-acetic acid production, phosphate solubilization and biofilm formation. These isolates were identified as belonging to Bradyrhizobium, Pseudomonas and Rhizobium. CONCLUSIONS: Bradyrhizobium sp. A2-10 and Pseudomonas sp. A6-05 were able to promote calopo plant growth using soil obtained from coal-mining degraded areas, thus indicating their potential as inoculants aiming at land reclamation. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first report of Pseudomonas nodule formation in calopo. Furthermore, the results demonstrated that autochthonous rhizobia obtained from degraded soils presented high SE in calopo and possess a wide range of plant-growth promoting traits. Ultimately, they may all contribute to an increased leguminous plant growth under stress conditions. The selected rhizobia strains may be used as inoculants and present a valuable role in the development of strategies aiming to recover coal-mining degraded areas. Bacterial inoculants would greatly reduce the use of often harmful nitrogen fertilizers vastly employed in revegetation programmes of degraded areas.

A randomized clinical trial evaluating maxillary sinus augmentation with different particle sizes of demineralized bovine bone mineral: histological and immunohistochemical analysis.

This study was performed to investigate sinus floor augmentation with two different particle sizes of demineralized bovine bone mineral (DBBM) by means of histological and immunohistochemical (IHC) analysis. A randomized clinical trial was conducted involving 10 individuals requiring two-stage bilateral maxillary sinus augmentation for implant installation. The patients were randomly divided into two groups following a split-mouth design: the maxillary sinus on one side was filled with small-sized particles (0.25-1mm) and on the contralateral side with large-sized particles (1-2mm). After a healing period of 8 months, 25 implants were placed. During implant site preparation, bone biopsies were obtained from each sinus, perpendicular to the long axis of the implant (buccal-palatal direction), for descriptive and histomorphometric analyses. IHC staining for protein expression of osteocalcin (OCN), vascular endothelial growth factor (VEGF), and tartrate-resistant acid phosphatase (TRAP) was also performed. Histomorphometric analysis revealed no statistically significant difference in the percentage of biomaterial (32.4±8.56% and 38.0±6.92%), newly formed bone (36.1±9.60% and 36.7±5.79%), or connective tissue (30.4±8.63% and 23.8±6.16%) between the small- and large-sized particle groups, respectively. IHC analysis did not reveal differences in the expression of OCN, VEGF, or TRAP. These findings suggest that both particle sizes of DBBM are effective for bone augmentation in the maxillary sinus.

Chondrosarcoma of the jaw bones: a review of 224 cases reported to date and an analysis of prognostic factors.

The objective was to integrate the available published data on chondrosarcoma (CHS) of the jaw bones into a comprehensive analysis of its clinical and histological features, treatment, and prognostic factors. An electronic search was undertaken in October 2017. To be eligible, the publication had to provide sufficient clinical/histological data to confirm the diagnosis. One hundred and ten publications (224 cases of CHS) were identified and included. There was a slightly higher prevalence of CHS in males than in females. Most subjects with CHS were in the second to fifth decades of life. The most common symptom was swelling and the most commonly observed location was the maxilla. Histologically, most tumours were of the conventional type and were low grade tumours. The treatment of choice was tumour resection. Histological grade, treatment with chemotherapy alone, and the presentation of recurrence or metastasis were found to be significant independent prognostic factors: patients who presented high-grade tumours, who received chemotherapy alone as the treatment of choice, and those who presented recurrence or metastasis were more likely to have a worse prognosis. In addition, radical surgery associated with radiotherapy as the treatment protocol showed a better prognosis.

Clinicopathological analysis of odontogenic tumors over 22 years period: Experience of a single center in northeastern Brazil.

BACKGROUND: Odontogenic tumors (OTs) are uncommon neoplastic lesions of the maxilla and mandible, which present difficult diagnosis and therapeutics. This paper aims to determine the frequency and distribution of OTs, over a period of 22 years, at a public university in Northeastern Brazil. MATERIAL AND METHODS: We reviewed all cases of OTs from oral pathology laboratory of Federal University of Rio Grande do Norte (UFRN), from 1996 to 2017. The tumors were classified according to the latest (2017) World Health Organization Classification of Tumors. Data on age, gender, anatomic site, symptomatology, radiographic findings and tumor size were analyzed. RESULTS: In the analyzed period, 247 cases of OTs were diagnosed. Epithelial tumors were more common with 127 cases (51.8%). The most common tumors were ameloblastoma (n = 112 / 45.4%), odontoma (n = 89 / 36.1%) and odontogenic myxoma (n = 17 / 6.9%). Malignant odontogenic tumors were extremely rare in the studied population with only 2 cases (0.8%) of diagnosed carcinomas. These tumors were diagnosed in a wide age range, from 5 to 81 years, being more common in the second and third decades of life. In general, the mandible was the most affected anatomic site (n = 162/66%) and the mandible:maxilla ratio was of 2:1. Ameloblastoma was the tumor with the highest number of symptomatic cases (n = 26) and with the highest mean size (cm) with 4.5cm. CONCLUSIONS: Odontogenic tumors were rare in the sample studied (2.2%), with ameloblastoma and odontoma being the most common tumors. Continuous studies that show the characteristics of these lesions are fundamental, especially after modifications in the international classification.

Clinicopathological evaluation and survival of patients with squamous cell carcinoma of the tongue.

BACKGROUND: Early detection of oral cancer is the most effective means of reducing morbidity, complexity, and extent of treatment. This study evaluated the clinicopathological profile of epidermoid carcinoma of the tongue, including treatment and survival. MATERIAL AND METHODS: This observational, retrospective cross-sectional study evaluated patients with squamous cell carcinoma of the tongue treated at the Dr. Luiz Antônio Hospital, Natal, Brazil, from January 2001 to December 2011. Survival variables were calculated using the Kaplan-Meier method and compared by log rank tests. RESULTS: Of the 412 patients diagnosed in this period, 298 (72.3%) were men; their mean age was 60.5 years, and 69.2% were diagnosed with stage III/IV tumours. Improved survival was associated with early stage diagnosis, absence of affected lymph nodes at diagnosis, and treatment with surgery alone. CONCLUSIONS: Late stage diagnosis of oral cancer negatively affects patient survival. In addition, the general public should be made aware of the prognostic factors for oral SCC of the tongue and of the importance of periodic examinations of the oral cavity.

High irisin levels in overweight/obese children and its positive correlation with metabolic profile, blood pressure, and endothelial progenitor cells.

BACKGROUND AND AIMS: Irisin is involved in the compensatory mechanisms for metabolic regulation and appears to be associated with glucose homeostasis and lipid profile. However, it's possible implications on obesity-associated cardiometabolic complications have not been completely elucidated. This study aimed to investigate the association between irisin level and anthropometric data, metabolic parameters, blood pressure, and endothelial progenitor cells (EPCs) level among children with overweight/obesity. METHODS AND RESULTS: This study included 24 children with overweight/obesity (9 girls and 15 boys) and 63 children with normal weight (25 girls and 38 boys). The anthropometric data, blood pressure, blood biochemistry, EPCs and irisin levels were evaluated. Children with overweight/obesity had significantly higher circulating irisin and EPCs levels than those with normal weight (P < 0.001). Additionally, we found that irisin level was positively correlated with BMI (rho = 0.407), waist circumference (rho = 0.449), triglycerides (rho = .334), glucose (rho = 0.226), insulin (rho = 0.533), HOMA (rho = 0.545), and negatively correlated with HDL cholesterol level (rho = -0.218). Importantly, we also found that irisin levels were significantly correlated with systolic (rho = 0.420), diastolic (rho = 0.331) blood pressure and circulating EPCs level (rho = 0.391). CONCLUSION: Our study provides evidence that overweight/obese children had elevated circulating levels of both irisin and EPCs and address the gap in the literature with regard to the understanding of the implications of irisin on obesity-related cardiometabolic complications among these children and also highlight the possible involvement of irisin regulation on insulin resistance and endothelial function in childhood overweight and obesity.

Cell toxicity by ricin and elucidation of mechanism of Ricin inactivation.

Castor cake is a by-product of the extraction of oil from from seeds of castor plants (Ricinus communis). This by-product contains high levels of proteins, but a toxic protein, ricin, limits its use as an animal feed. Ricin can be efficiently inactivated by treatment with calcium oxide (CaO), which can be evaluated by a cytotoxicity assay using LLC-MK2 cells. The mechanism by which the CaO treatment inactivates ricin, however, is unclear. We report the structural changes responsible for ricin inactivation. Purified ricin was treated with 0.6% CaO and then analyzed by mass spectrometry. This treatment degraded the ricin at preferential sites. The aqueous CaO solution had a pH >12, which preferentially cleaved asparagine residues, followed by glutamine, serine and glycine residues. The alkaline pH affected the tertiary structure of the ricin, cleaving its polypeptide chains and thereby eliminating its cytotoxic activity.

Clinicopathological analysis of head and neck rhabdomyosarcoma: A series of 10 cases and literature review.

BACKGROUND: To describe the clinicopathological characteristics of a series of head and neck rhabdomyosarcoma (RMS) and to review the literature. MATERIAL AND METHODS: Cases diagnosed as RMS affecting the head and neck region were retrospectively retrieved from the files of two Brazilian institutions from January 2006 to January 2017. Data on clinical features (sex, age and affected site), microscopic subtype, immunohistochemical results, treatment employed and follow-up status were obtained from the patient's medical charts. RESULTS: During the period considered, 10 cases of RMS were identified. Females predominated (4M:6F), the mean age at diagnosis was 16.5 years-old and the orbit was the most affected site (4 cases). Microscopically, most cases were classified as embryonal RMS (6 cases) and the Desmin/Myogenin/Myo-D1 immunohistochemical positivity was useful to confirm the diagnosis. Chemotherapy and radiotherapy were applied to 9 and 8 patients respectively, whereas 2 patients were treated by surgery. Recurrences occurred in 3 patients and distant metastasis in 2 cases. Nine patients were alive in their last follow-up, 3 of them with disease, whereas 1 patient died due to the disease. CONCLUSION: Head and neck RMS is an aggressive malignant neoplasm which demands especial concern to achieve early diagnosis and successful treatment.

Epidemiologic study of odontogenic and non-odontogenic cysts in children and adolescents of a Brazilian population.

BACKGROUND: the objective of this study was to describe the frequency of cystic lesions in a Brazilian population of patients histopathologically diagnosed in the first and second decade of life. MATERIAL AND METHODS: Retrospective descriptive cross-sectional study was performed. Biopsy records were obtained from the archives of a Brazilian referral center between 1980 and 2016. RESULTS: A total of 2.114 biopsy records of pediatric patients were analyzed with oral and maxillofacial lesions. Data such as gender, age, anatomical location, and histopathological diagnosis were collected and categorized. Among all oral and maxillofacial lesions (n=2.114), were diagnosed 294 cases of odontogenic cysts (13.9%) and 16 cases of non-odontogenic cysts (0.8%). The most frequent lesions in each group were, respectively: radicular cyst (n=145) and epidermoid cyst (n=4). These lesions were most common in female (n=158), with a mean age of 14 years. For intraosseous lesions, the mandible (n=148) was the most affected anatomic site; moreover, the floor of the mouth (n=6) was most affected by cysts in soft tissues. CONCLUSIONS: Odontogenic cysts were relatively common in population studied, but non-odontogenic cysts were rare in these patients.