Interrogation of TERT promoter hotspot mutations in ameloblastoma and ameloblastic carcinoma.

BACKGROUND: TERT promoter mutations increase telomerase activity, conferring cell immortality. The coexistence of TERT promoter mutations with BRAFV600E is associated with aggressiveness. Ameloblastoma and ameloblastic carcinoma are infiltrative neoplasms that harbor BRAFV600E; however, it remains unknown if these odontogenic tumors also show TERT promoter mutations. METHODS: Genomic DNA of paraffin-embedded ameloblastomas (n = 6) and ameloblastic carcinomas (n = 3) were Sanger-sequenced to assess the hotspot TERT promoter mutations C228T and C250T. BRAFV600E status was screened by TaqMan allele-specific quantitative polymerase chain reaction. RESULTS: None of the samples harbored TERT promoter mutations. The BRAFV600E mutation was positive in 3 of 6 of ameloblastomas and in 1 of 3 of ameloblastic carcinomas. CONCLUSION: The absence of TERT promoter mutation in the samples indicates that this molecular event is not relevant to the tumors' pathogenesis. Further studies are necessary to explore undefined genetic or epigenetic mechanisms related to TERT-upregulation in ameloblastoma, and the telomerase activity in ameloblastic carcinoma.

Can SARS-CoV-2 screening in oral biopsies aid epidemiological surveillance?

BACKGROUND: Three years after the first confirmed COVID-19 case in Brazil, the outcomes of Federal government omissions in managing the crisis and anti-science stance heading into the pandemic have become even more evident. With over 36 million confirmed cases and nearly 700 000 deaths up to January 2023, the country is one of the hardest-hit places in the world. The lack of mass-testing programs was a critical broken pillar responsible for the quick and uncontrolled SARS-CoV-2 spread throughout the Brazilian population. Faced with this situation, we aimed to perform the routine SARS-CoV-2 screening through RT-qPCR of oral biopsies samples to aid in the asymptomatic epidemiological surveillance during the principal outbreak periods. METHODS: We analyzed 649 formalin-fixed paraffin-embedded oral tissue samples from five important oral and maxillofacial pathology laboratories from the north, northeast, and southeast geographic regions of Brazil. We also sequenced the whole viral genome of positive cases to investigate SARS-CoV-2 variants. RESULTS: The virus was detected in 9/649 analyzed samples, of which three harbored the Variant of Concern Alpha (B.1.1.7). CONCLUSION: Although our approach did not value aiding asymptomatic epidemiological surveillance, we could successfully identify a using FFPE tissue samples. Therefore, we suggest using FFPE tissue samples from patients who have confirmed diagnosis of SARS-CoV-2 infection for phylogenetic reconstruction and contraindicate the routine laboratory screening of these samples as a tool for asymptomatic epidemiological surveillance.

LipNanoCar Technology - A Versatile and Scalable Technology for the Production of Lipid Nanoparticles.

The extensive knowledge in the miniemulsion technique used in biocatalysis applications by the authors allowed the development of drug delivery systems that constitutes the LipNanoCar technology core for the production of lipid nanoemulsions and solid lipid nanoparticles. The LipNanoCar technology, together with adequate formulations of different oils, fatty acids, surfactants, and temperature, allows the entrapment of several bioactive and therapeutic compounds in lipid nanoparticles for cosmetic, nutrition, and pharmaceutical applications.The LIpNanoCar technology allowed lipid nanoparticles production with average sizes ranging from 100 to 300 nm and Zeta Potentials between -55 and -20 mV. Concomitantly, high entrapment or encapsulation efficiencies (%EE) were achieved, as illustrated in this work for ß-carotene and vitamins derivatives (>85%) for cosmetic application, and for antibiotics currently used in chemotherapy, like rifampicin (69-85%) and pyrazinamide (14-29%) against Mycobacterium tuberculosis (TB), and ciprofloxacin (>65%) and tobramycin (~100%) in Cystic Fibrosis (CF) respiratory infections therapy. Ciprofloxacin presented, for example, a quick-release from the lipid nanoparticles using a dialysis tubing (96% in the first 7 h), but slower than the free antibiotic (95% in the first 3 h). This result suggests that ciprofloxacin is loaded near the external surface of the lipid nanoparticles.The toxicity and validation of entrapment of antibiotics in lipid nanoparticles for Cystic Fibrosis therapy were assessed using Caenorhabditis elegans as an animal model of bacterial infection. Fluorescence microscopy of an entrapped fluorescent dye (DiOC) confirmed the uptake of the lipid nanoparticles by ingestion, and their efficacy was successfully tested in C. elegans. Burkholderia contaminans IST408 and Burkholderia cenocepacia K56-2 infections were tested as model bacterial pathogens difficult to eradicate in Cystic Fibrosis respiratory diseases.

Broad Spectrum Functional Activity of Structurally Related Monoanionic Au(III) Bis(Dithiolene) Complexes.

The biological properties of sixteen structurally related monoanionic gold (III) bis(dithiolene/ diselenolene) complexes were evaluated. The complexes differ in the nature of the heteroatom connected to the gold atom (AuS for dithiolene, AuSe for diselenolene), the substituent on the nitrogen atom of the thiazoline ring (Me, Et, Pr, iPr and Bu), the nature of the exocyclic atom or group of atoms (O, S, Se, C(CN)2) and the counter-ion (Ph4P+ or Et4N+). The anticancer and antimicrobial activities of all the complexes were investigated, while the anti-HIV activity was evaluated only for selected complexes. Most complexes showed relevant anticancer activities against Cisplatin-sensitive and Cisplatin-resistant ovarian cancer cells A2780 and OVCAR8, respectively. After 48 h of incubation, the IC50 values ranged from 0.1-8 µM (A2780) and 0.8-29 µM (OVCAR8). The complexes with the Ph4P+ ([P]) counter-ion are in general more active than their Et4N+ ([N]) analogues, presenting IC50 values in the same order of magnitude or even lower than Auranofin. Studies in the zebrafish embryo model further showed that, despite their marked anticancer effect, the complexes with [P] counter-ion exhibited low in vivo toxicity. In general, the exocyclic exchange of sulfur by oxygen or ylidenemalononitrile (C(CN)2) enhanced the compounds toxicity. Most complexes containing the [P] counter ion exhibited exceptional antiplasmodial activity against the Plasmodium berghei parasite liver stages, with submicromolar IC50 values ranging from 400-700 nM. In contrast, antibacterial/fungi activities were highest for most complexes with the [N] counter-ion. Auranofin and two selected complexes [P][AuSBu(=S)] and [P][AuSEt(=S)] did not present anti-HIV activity in TZM-bl cells. Mechanistic studies for selected complexes support the idea that thioredoxin reductase, but not DNA, is a possible target for some of these complexes. The complexes [P] [AuSBu(=S)], [P] [AuSEt(=S)], [P] [AuSEt(=Se)] and [P] [AuSeiPr(=S)] displayed a strong quenching of the fluorescence intensity of human serum albumin (HSA), which indicates a strong interaction with this protein. Overall, the results highlight the promising biological activities of these complexes, warranting their further evaluation as future drug candidates with clinical applicability.

Whole-exome sequencing reveals novel vacuolar ATPase genes' variants and variants in genes involved in lysosomal biology and autophagosomal formation in oral granular cell tumors.

BACKGROUND: Granular cell tumors (GCTs) are rare neuroectodermal soft tissue neoplasms that mainly affect the skin of the upper limbs and trunks and the oral cavity. GCTs are derived from Schwann cells and, ultrastructurally, their intracytoplasmic granules are considered autophagosomes or autophagolysosomes and are consistent with myelin accumulation. METHODS: In this study, a convenience set of 22 formalin-fixed, paraffin-embedded samples of oral GCTs, all but one sample located at the tongue, was screened for mutations by whole-exome (WES) or targeted sequencing. RESULTS: WES revealed two novel variants in genes of the vacuolar ATPase (V-ATPase) complex: ATP6AP1 frameshift c.746_749del, leading to p.P249Hfs*4, and ATP6V1A non-synonymous c.G868A, leading to p.D290N. Each of these mutations occurred in one case. With regard to the samples that were wild type for these V-ATPase variants, at least two samples presented variants in genes that are part of endosomal/lysosomal/autophagosomal networks including ABCA8, ABCC6, AGAP3, ATG9A, CTSB, DNAJC13, GALC, NPC1, SLC15A3, SLC31A2, and TMEM104. CONCLUSION: Although the mechanisms involved in oral GCT initiation and progression remain unclear, our results suggest that oral GCTs have V-ATPase variants similarly to GCTs from other tissues/organs, and additionally show variants in lysosomes/endosomes/autophagosomal genes.

Sialolipomas of minor salivary glands: A multi-institutional study and literature review.

BACKGROUND: Sialolipoma is a rare histological variant of lipoma commonly misdiagnosed and composed of a proliferation of mature adipocytes with secondary entrapment of normal salivary gland tissue. The purpose of the present study is to report the clinicopathologic and immunohistochemical features of 10 new cases of sialolipomas in conjunction with a review of the literature. METHODS: A retrospective descriptive cross-sectional study was performed. A total of 54,190 biopsy records of oral and maxillofacial lesions from four oral and maxillofacial pathology services in Brazil were analysed. All cases of lipomas were reviewed, and clinical, demographic and histopathological data were collected of all cases compatible with sialolipomas. In addition, immunohistochemistry stains (AE1/AE3, CK7, 34ßE12, S-100, HHF35, α-SMA and Ki-67) and a literature review based on a search of three electronic databases (PubMed, Web of Science and Scopus) were performed. RESULTS: Among all lipomas reviewed, there were 10 cases of sialolipomas. The series comprised of 7 females (70.0%) and 3 males (30.0%), with a mean age of 46.1 ± 21.5 years (range: 11-71 years) and a 2.3:1 female-to-male ratio. The lower lip (n = 3, 30.0%) and tongue (n = 2, 20.0%) were the most common locations, presenting clinically as a nodule of slow growth and normal colour. Conservative surgical excision was the treatment in all cases. No recurrence was observed. CONCLUSION: Sialolipomas are a rare histological variant of lipoma, affecting the salivary glands, mainly in the parotid gland and palate of female adults. Pathologists must recognise sialolipomas to avoid misdiagnoses with other lipomatous tumours that can affect salivary glands.

Odontogenic myxomas lack PDGFRB mutations reported in myofibromas.

BACKGROUND: The molecular pathogenesis of odontogenic myxoma has not been established yet. Considering that odontogenic myxoma may show myofibroblastic differentiation and myxoid areas can be observed in intra-osseous myofibromas, we tested the hypothesis whether both tumors share a common molecular profile. As recent studies have reported PDGFRB recurrent driver mutations in myofibroma, we evaluated PDGFRB mutations in odontogenic myxomas. METHODS: A convenience sample of 15 odontogenic myxomas cases was selected. We direct sequenced PDGFRB exons 12 and 14, where p.R561C (c.1681C>T) and p.N666K (c.1998C>G) hotspot mutations have been reported among others in single and/or multiple myofibromas. RESULTS: All 15 odontogenic myxoma samples were successfully sequenced, and all 15 had wild-type sequences for the PDGFRB mutations investigated. CONCLUSION: Our findings suggest that PDGFRB mutations do not play a role in odontogenic myxoma pathogenesis, which might be helpful in the differential diagnosis of challenging cases.

Solitary fibrous tumour of the oral cavity: An update.

BACKGROUND: Solitary fibrous tumour is an unusual neoplasm of the oral cavity that is sometimes not clinically distinguishable from other lesions. The purpose of the present study was to review the clinical, microscopic and molecular aspects of malignant and benign solitary fibrous tumour of the oral cavity currently available in literature. METHODS: For our review, an electronic search was performed using PubMed, Scopus, Ovid/MedLine, Web of science and ProQuest Dissertations and Theses Global database. RESULTS: A total of 74 publications reporting 150 cases were included. Oral solitary fibrous tumours are most frequently described as submucosal, well-circumscribed, asymptomatic nodule, more prevalent in females in their fourth to fifth decades of life. Buccal mucosa is the most commonly affected site by the benign tumour variant, whereas the tongue is the most common location affected by the malignant form of the neoplasm. Most of the lesions were treated by conservative surgery. One recurrent malignant tumour and one metastasis are reported. CONCLUSION: Asymptomatic normal-coloured submucosal nodules located in the buccal mucosa and tongue in adult patients are suggestive of oral solitary fibrous tumour, but only a careful microscopic examination can differentiate benign from malignant variants and the use of immunohistochemistry (CD34, Bcl-2, CD99 and STAT6), and cytogenetic studies (NAB2-STAT6) contribute significantly to confirm the diagnosis of solitary fibrous tumour in difficult cases.

Genotoxic and cytotoxic effects of mobile phone use on the oral epithelium: a systematic review with meta-analysis.

The use of mobile phones is based on radiofrequency (RF) waves, and the devices act as transmitters and receivers of non-ionizing energy. The micronucleus test was developed to identify increases in the occurrence of mutations in cells exposed to various agents. This systematic review with meta-analysis adhered to the following protocol: defining the objective, outlining the search method (PICO model), conducting the search, identifying literature, selecting articles, and extracting data. The study aimed to answer the following research question: Does non-ionizing radiation emitted by mobile phones have genotoxic and/or cytotoxic effects on the oral epithelium? The search for evidence published 2009-2019 was conducted in the MEDLINE, PubMed, Scopus, LILACS, Google Scholar, PROSPERO, and Cochrane Library databases. The following inclusion criteria were defined: investigations of effects on the oral mucosa related to RF; investigations of cytotoxic and/or genotoxic effects; investigations involving humans; and investigations using cells exfoliated from the oral epithelium. Investigations related to the parotid gland were excluded. The search strategy found 464 articles; after application of the eligibility criteria, 358 abstracts were analyzed and 351 abstracts excluded. After 7 full texts were reviewed, 1 study was excluded. The 6 included studies were classified as level 5 quality of evidence (observational studies). The meta-analysis included 2 studies that compared the frequency of micronuclei on the side exposed to RF electromagnetic fields (RF-EMFs) to that on the unexposed side. The studies evaluated presented a low degree of evidence, but the meta- analysis indicated that no genotoxic effects are associated with mobile phone use. However, observations of other nuclear abnormalities in some studies suggest the occurrence of cytotoxic effects caused by exposure to the RF-EMFs emitted by mobile phones. More studies are necessary to prove or refute this association.

KRAS mutations drive adenomatoid odontogenic tumor and are independent of clinicopathological features.

Adenomatoid odontogenic tumor is a benign encapsulated epithelial odontogenic tumor that shows an indolent clinical behavior. We have reported in a few adenomatoid odontogenic tumors mutations in KRAS, which is a proto-oncogene frequently mutated in cancer such as lung, pancreas, and colorectal adenocarcinomas. We aimed to assess KRAS mutations in the hotspot codons 12, 13, and 61 in a large cohort of adenomatoid odontogenic tumors and to test the association of these mutations with clinical (age, site, tumor size, follicular/extrafollicular subtypes) and histopathological parameters. Thirty eight central cases were studied. KRAS codon 12 mutations were assessed by TaqMan allele-specific qPCR (p.G12V/R) and/or Sanger sequencing, and codon 13 and 61 mutations were screened by Sanger. Histological tumor capsule thickness was evaluated by morphometric analysis. Additionally, the phosphorylated form of the MAPK downstream effector ERK1/2 was investigated. Statistical analysis was carried out to test the association of KRAS mutations with clinicopathological parameters. KRAS c.35 G >T mutation, leading to p.G12V, was detected in 15 cases. A novel mutation in adenomatoid odontogenic tumor, c.34 G >C, leading to p.G12R, was detected in 12 cases and the other 11 were wild-type. Codon 12 mutations were not associated with the clinicopathological parameters tested. RAS mutations are known to activate the MAPK pathway, and we show that adenomatoid odontogenic tumors express phosphorylated ERK1/2. In conclusion, a high proportion of adenomatoid odontogenic tumors (27/38, 71%) have KRAS codon 12 mutations, which occur independently of the clinicopathological features evaluated. Collectively, these findings indicate that KRAS mutations and MAPK pathway activation are the common features of this tumor and some cancer types. Although it is unclear why different codon 12 alleles occur in different disease contexts and the complex interactions between tumor genotype and phenotype need clarification, on the basis of our results the presence of KRAS p.G12V/R favors the adenomatoid odontogenic tumor diagnosis in challenging oral neoplasm cases.

Differential effects of Th17 cytokines during the response of neutrophils to Burkholderia cenocepacia outer membrane protein A.

T helper 17 cells are involved in the immunopathology of cystic fibrosis. They play a key role in recruitment of neutrophils, which is the first line of defence against bacteria. Additionally, Burkholderia cenocepacia outer membrane protein A (OmpA) BCAL2958 is considered a potential protective epitope for vaccine development. The present study aimed to investigate the neutrophil response to OmpA in the presence of Th17 cytokines, IL-17 and IL-22 at different times of activation. Neutrophils were isolated from whole blood of healthy volunteers and activated with OmpA in the presence of IL-17, IL-22 or both cytokines together. Supernatant was collected after 1 h, 2 h, 4 h, 8 h, and 12 h. Neutrophil activation was assessed by measuring MPO, TNF-α, elastase, hydrogen peroxide, catalase and NO. The results revealed that the combination of IL-17 and IL-22 cytokines induced the release of NE, catalase, H2O2 and TNF-α from neutrophils activated with Burkholderia OmpA at late stages of activation. However, IL-22 alone or IL-17 alone decreased the myeloperoxidase (MPO), catalase and NE levels at early stages of neutrophil activation. The presence of IL-17 alone led to a significant increase in TNF-α level after 1 h and 12 h. However, the presence of IL-22 alone led to a significant increase in TNF-α level after only 1 h but a significant decrease after 8 h of activation was observed as compared to OmpA stimulated neutrophils. In conclusion, Th17 cytokines IL-17 and IL-22, have differential effects during the neutrophil response to Burkholderia OmpA.

Burkholderia puraquae sp. nov., a novel species of the Burkholderia cepacia complex isolated from hospital settings and agricultural soils.

Bacteria from the Burkholderia cepacia complex (Bcc) are capable of causing severe infections in patients with cystic fibrosis (CF). These opportunistic pathogens are also widely distributed in natural and man-made environments. After a 12-year epidemiological surveillance involving Bcc bacteria from respiratory secretions of Argentinean patients with CF and from hospital settings, we found six isolates of the Bcc with a concatenated species-specific allele sequence that differed by more than 3 % from those of the Bcc with validly published names. According to the multilocus sequence analysis (MLSA), these isolates clustered with the agricultural soil strain, Burkholderia sp. PBP 78, which was already deposited in the PubMLST database. The isolates were examined using a polyphasic approach, which included 16S rRNA, recA, Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), DNA base composition, average nucleotide identities (ANIs), fatty acid profiles, and biochemical characterizations. The results of the present study demonstrate that the seven isolates represent a single novel species within the Bcc, for which the name Burkholderia puraquae sp. nov. is proposed. Burkholderia puraquae sp. nov. CAMPA 1040T (=LMG 29660T=DSM 103137T) was designated the type strain of the novel species, which can be differentiated from other species of the Bcc mainly from recA gene sequence analysis, MLSA, ANIb, MALDI-TOF MS analysis, and some biochemical tests, including the ability to grow at 42 °C, aesculin hydrolysis, and lysine decarboxylase and ß-galactosidase activities.

Absence of BRAFV600E mutation in odontogenic keratocysts.

BACKGROUND: Mutations in the patched 1 (PTCH1) gene are the main genetic alteration reported in sporadic and nevoid basal cell carcinoma-associated odontogenic keratocyst (OKC). Oncogenic mutations, including BRAFV600E, previously considered exclusive of malignant neoplasms have been reported in odontogenic tumors. Recently, a high frequency of BRAFV600E mutation has been reported in OKC. Because of the considerable recurrence rate of OKC, the identification of druggable genetic mutations can be relevant in the management of extensive lesions. METHODS: A set of 28 OKCs was included in this work. Initially, 10 sporadic and eight OKC samples from four NBCCS patients (a pair of lesions from each syndromic patient) were submitted to targeted next-generation sequencing (NGS) of 2800 different mutations in 50 oncogenes and tumor suppressor genes, including BRAF. Ten extra sporadic OKC samples were included to assess BRAFV600E mutation using TaqMan allele-specific qPCR. RESULTS: The following missense mutations occurred in one case each: ATM p.Ser333Phe, SMO p.Gly416Glu, PIK3CA p.Ser326Phe, FBXW7 p.Ser438Phe, JAK2 p.Ser605Phe, PTEN p.Arg173His, ATM p.Cys353Arg, PTEN p.Ser294Arg, MET p.His1112Tyr. None of the 18 samples showed the BRAFV600E (or any other V600) mutation in the NGS. BRAFV600E mutation was detected by qPCR in one of the 10 OKC. Collectively, our results show BRAFV600E mutation in 1 of 28 OKC cases. CONCLUSION: On the basis of our results, OKCs do not present recurrent hotspot mutations in these 50 genes commonly mutated in cancer. In addition, BRAFV600E does not play a central role in OKC pathogenesis.

Next-generation sequencing of oncogenes and tumor suppressor genes in odontogenic myxomas.

BACKGROUND: Mutations previously considered drivers of malignant neoplasms also occur in benign tumors. From the biological perspective, the study of malignant and benign neoplasms is equally relevant. The study of rare tumors contributes to the understanding of the more common ones, as both could share the same hallmark genetic drivers. The identification of driver mutations in benign tumors is facilitated by the fact that they harbor quiet genomes. Pathogenic mutations have being described in benign epithelial odontogenic tumors, such as ameloblastomas and adenomatoid odontogenic tumors. However, the molecular pathogenesis of odontogenic myxoma (OM), a benign aggressive ectomesenchymal tumor, is still poorly characterized, precluding the development of personalized therapy. Aiming to find druggable genetic mutations, we investigated in OM mutations in 50 genes commonly mutated in cancer. METHODS: We used targeted next-generation sequencing to interrogate over 2,800 COSMIC mutations in OM. RESULTS: Missense single nucleotide variants were detected in KDR, TP53, PIK3CA, KIT, JAK3; however, these did not include pathogenic mutations. CONCLUSION: These aggressive tumors do not harbor pathogenic mutations in genes commonly mutated in human cancers or if they do, these mutations probably occur in a low proportion of cases.

Association between histopathological features of dysplasia in oral leukoplakia and loss of heterozygosity.

AIMS: Oral leukoplakia (OL) dysplasia is graded on the basis of architectural and cytological features, and grade does not correlate well with malignant transformation. Loss of heterozygosity (LOH) profiles have been validated as risk predictors of OL malignant transformation. We aimed to assess whether the histological parameters used to grade dysplasia show different LOH profiles. METHODS AND RESULTS: Areas of epithelial dysplasia of 29 OL samples were microdissected, and LOH was assessed by use of a panel of 11 microsatellite markers located on chromosomes 3, 9, 11, and 17. Dysplasia was graded, and the cytological and architectural parameters were scored. Dysplasia was graded as mild in 18 samples, moderate in nine, and severe in two. The moderate/severe dysplasias and the mild dysplasias did not show different frequencies of allelic loss. Irregular epithelial stratification was associated with LOH at marker D3S1234 (3p14.2). In addition, the presence of drop-shaped rete ridges and premature keratinization in single cells showed associations with LOH at D9S162 (9p22) and P53 (17p13.1), respectively. CONCLUSIONS: We provide evidence that architectural and cellular changes in OL have different LOH patterns.

Human Milk Composition and Preservation: Evaluation of High-pressure Processing as a Nonthermal Pasteurization Technology.

Human milk is seen not only as a food, but as a functional and dynamic biologic system. It provides nutrients, bioactive components, and immune factors, promoting adequate and healthy growth of newborn infants. When mothers cannot supply their children, donated breast milk is the nutrition recommended by the World Health Organization, as it is a better alternative than infant formula. However, because of the manner in which donor milk is handled in human milk banks (HMB) many of the properties ascribed to mother's own milk are diminished or destroyed. The major process responsible for these losses is Holder pasteurization. High-pressure processing (HPP) is a novel nonthermal pasteurization technology that is being increasingly applied in food industries worldwide, primarily as an alternative to thermal treatment. This is due to its capacity to inactivate microorganisms while preserving both nutritional and bioactive components of foods. This review describes human milk composition and preservation, and critically discusses HMB importance and practices, highlighting HPP as a potential nonthermal pasteurization technology for human milk preservation. HPP technology is described and the few currently existing studies of its effects in human milk are presented.

Lip cancer and pre-cancerous lesions harbor TP53 mutations, exhibit allelic loss at 9p, 9q, and 17p, but no BRAFV600E mutations.

Molecular mechanisms of lip squamous cell carcinoma (LSCC) and actinic cheilitis (AC) are unclear. We aimed at assessing loss of heterozygosity (LOH) and TP53 and BRAF V600E mutations in these lesions. Formalin-fixed paraffin-embedded (FFPE) samples of 17 LSCC and 16 AC were included, with additional 5 fresh LSCC genotyped for TP53 mutations. LOH was assessed by six polymorphic markers located at 9p22, 9q22, and 17p13 and correlated with cell proliferation (Ki-67) and P53 immunostaining. Direct sequencing of TP53 exons 2-11 (fresh samples), and exons 5-9 (FFPE samples) was carried out. BRAF V600E mutation was genotyped in eight LSCC. LOH occurred in at least one marker in 15/17 LSCC and in 9/16 AC. The marker exhibiting the highest frequency of allelic loss (FAL) in LSCC was D9S157 (8/12 informative cases) and D9S287 in AC (4/11 informative cases). Cell proliferation was not correlated with LOH or with the FAL and no correlation between P53 IHC and 17p LOH was observed. We found TP53 missense mutations in both lesions and nonsense in LSCC, including CC>TT transition, which is a marker of UV damage. BRAF V600E mutation was not detected. LOH and TP53 mutations detected in LSCC and AC may be associated with tumorigenesis, whereas BRAF V600E mutation does not seem to significantly contribute to LSCC pathogenesis.

Effect of maternal skin-to-skin contact on decolonization of Methicillin-Oxacillin-Resistant Staphylococcus in neonatal intensive care units: a randomized controlled trial.

BACKGROUND: Decolonization with topical antibiotics is necessary to control outbreaks of multidrug-resistant bacterial infection in the Neonatal Intensive Care Unit (NICU), but can trigger bacterial resistance. The objective of this study was to determine whether skin-to-skin contact of newborns colonized with Methicillin-Oxacillin Resistant Staphylococcus aureus or Methicillin-Oxacillin-Resistant Coagulase-Negative Staphylococcus aureus (MRSA/MRSE) with their mothers could be an effective alternative to promote bacterial decolonization of newborns' nostrils. METHODS: We performed a randomized clinical trial with 102 newborns admitted to the NICU in three hospitals in São Luís, Brazil. Inclusion criteria were birth weight of 1300 to 1800 g, more than 4 days of hospitalization, newborns with positive nostril cultures for MRSA and/or multidrug-resistant coagulase-negative Staphylococcus and mothers not colonized by these bacteria. We used a random number algorithm for randomization. Allocation was performed using sealed opaque envelopes. Skin-to-skin contact was given twice a day for 60 minutes for seven consecutive days. The control group received routine care without skin-to-skin contact. There was no masking of newborn's mothers or researchers but the individuals who carried out bacterial cultures and assessed results were kept blind to group allocation. The primary outcome was colonization status of newborns' nostrils after 7 days of intervention. The directional hypothesis was that more newborns who receive skin-to-skin holding 2 hours/day for 7 days than newborns who receive normal care will be decolonized. RESULTS: Decolonization of MRSA/MRSE was greater in the intervention group (Risk Ratio = 2.27; 95% CI 1.27-4.07, p-value = 0.003). Number Needed to Treat (NNT) was 4.0 (95% CI 2.2 - 9.4). After adjustment for the possible confounding effects of small for gestational age birth, antibiotic use, need for resuscitation, sex and cesarean delivery, skin-to-skin contact remained strongly associated with decolonization of newborns' nostrils from MRSA/MRSE bacteria (p = 0.007). There was no need to interrupt the trial for safety reasons. CONCLUSION: Skin-to-skin contact might be an effective and safe method for promoting decolonization of newborns' nostrils colonized by MRSA/MRSE. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov ( NCT01498133 , November 21, 2011).