Isolation of total DNA from Placenta Samples, both Fresh and following Formalin and Paraffin Treatment.

The isolation of DNA from placental tissue suspected of infection is an important tool for identifying microorganisms such as bacteria, fungi, and viruses associated with complications during and after pregnancy. While experts primarily process placental tissue, the preservation methods employed pose challenges to extracting complete DNA. Therefore, selecting the appropriate protocol is paramount to achieving greater efficiency in obtaining genetic material.

New artificial hematophagy system with attractive polymeric biofilm for maintenance of Culex quinquefasciatus (Diptera: Culicidae) in the laboratory.

BACKGROUND: Maintaining mosquito colonies in the laboratory requires a blood supply so that females' oocytes can mature and oviposition can take place. In this study, a new artificial hematophagy system for colonization and maintenance of Culex quinquefasciatus in the laboratory was developed and tested. METHODS: We developed an attractive polymeric biofilm including 25% L-lactic acid for use as a membrane in an artificial hematophagy system and compared the feeding rate of females with Parafilm-M®. We also evaluated the oviposition rate, larval survival and adult emergence of females fed through the attractive biofilm. RESULTS: The average percentage of female Cx. quinquefasciatus fed through the attractive biofilm was 87%, while only 20% became engorged with Parafilm-M® (p < 0.0001). Feeding through the attractive biofilm developed in this study produced high levels of evaluated biological parameters; the percentage of egg laying by females that underwent artificial hematophagy through the biofilm was 90%, with an average of 158 eggs per raft. From these eggs, 97% of the larvae hatched, of which 95% reached the pupal stage. The adult emergence rate corresponded to 93% of pupae. CONCLUSIONS: Insects fed with attractant through the biofilm system had a higher engorgement rate compared to those fed through Parafilm-M®. Our study is preliminary and suggests that polymeric biofilm has great potential for artificially feeding mosquitoes in the laboratory. Based on this research, new studies will be carried out with biofilm and different systems.

Genotyping of dengue virus from infected tissue samples embedded in paraffin.

Dengue has become one of the vector-borne diseases that affect humans worldwide. In Latin American countries, Colombia is historically one of the most affected by epidemics of this flavivirus. The underreporting of signs and symptoms of probable cases of dengue, the lack of characterization of the serotypes of the infection, and the few detailed studies of postmortem necropsies of patients are among other conditions that have delayed progress in the knowledge of the pathogenesis of the disease. This study presents the results of fragment sequencing assays on paraffin-embedded tissue samples from fatal DENV cases during the 2010 epidemic in Colombia. We found that the predominant serotype was DENV-2, with the Asian/American genotype of lineages 1 and 2. This work is one of the few reports of the circulating genotypes of dengue during the 2010 epidemic in Colombia, one of the most lethal dates in the country's history.

Short- and medium-chain chlorinated paraffins in fish from an anthropized south-western Atlantic estuary, Bahía Blanca, Argentina.

Chlorinated paraffins (CPs) are synthetic organic compounds of growing environmental and social concern. Short-chain chlorinated paraffins (SCCPs) were listed under the Stockholm Convention on Persistent Organic Pollutants (POPs) in 2017. Further, in 2021, medium-chain chlorinated paraffins (MCCPs) were proposed to be listed as POPs. We investigated SCCP and MCCP amounts and homolog profiles in four wild fish species from Bahía Blanca Estuary, a South Atlantic Ocean coastal habitat in Argentina. SCCPs and MCCPs were detected in 41% and 36% of the samples, respectively. SCCP amounts ranged from <12 to 29 ng g-1 wet weight and <750-5887 ng g-1 lipid weight, whereas MCCP amounts ranged from <7 to 19 ng g-1 wet weight and <440-2848 ng g-1 lipid weight. Amounts were equivalent to those found in fish from the Arctic and Antarctic Oceans and from some North American and Tibetan Plateau lakes. We performed a human health risk assessment and found no direct risks to human health for SCCP or MCCP ingestion, according to present knowledge. Regarding their environmental behavior, no significant differences were observed among SCCP amounts, sampling locations, species, sizes, lipid content, and age of the specimens. However, there were significant differences in MCCP amounts across species, which could be attributed to fish size and feeding habits. Homolog profiles in all fish were dominated by the medium-chlorinated (Cl6 and Cl7) CPs and shorter chain length CPs were the most abundant, with C10Cl6 (12.8%) and C11Cl6 (10.1%) being the predominant SCCPs and C14Cl6 (19.2%) and C14Cl7 (12.4%) the predominant MCCPs. To the best of our knowledge, this is the first study on the presence of CPs in the environment in Argentina and the South Atlantic Ocean. CP occurrence in the environment, particularly in the food chain, promotes the need for further research on their occurrence and behavior, and the impact of CPs in marine ecosystems in Argentina.

Roles of early events in the modifications undergone by bovine corneal endothelial cells during wound healing.

A mechanical injury in bovine corneal endothelial (BCE) cells in culture induces: (1) a fast calcium wave (FCW); (2) slow increases in cytosolic sodium and calcium, critical for the healing process, and (3) a rise in the apoptotic rate with respect to quiescent cells. In order to investigate the nature of the stimuli that determine the ionic changes and apoptotic response, we performed here studies on a non-injury model of tissue restitution in BCE monolayers. For this, we employed cell cultures grown to confluence in the presence of a Parafilm strip. We observed that, previously to strip removal, most of the border cells had already developed the slow ionic modifications, while in the scratch wounds these changes gradually occur after several hours of healing. This finding suggests that, in BCE cells, the presence of a free edge is sufficient to trigger ionic modifications necessary for wound healing and to elicit an augmented apoptotic response. The apoptotic index of the migrating cells in the Parafilm model (PF) was determined to be approximately two-fold the one of scratch wounds, a result that, in agreement with our previous observations, we attributed to the absence of the FCW in the PF experiments. The findings of this work further contribute to the understanding of epithelial wound healing, a crucial adaptive, and homeostatic response.

Effects of therapeutic ultrasound and paraffin with or without vacuum massage on biomechanical properties of grafted skin after burn: a randomized controlled trial.

OBJECTIVE: This study aimed to compare the effects of therapeutic ultrasound and paraffin with or without vacuum massage on the biomechanical properties of grafted skin after a burn. METHODS: A total of 44 patients with deep second- and third-degree burns, with a mean age of 35.89 (±11.53) years, who visited the Hospital Burn Unity, were included in the study. The therapeutic interventions were randomly defined by drawing lots, with a crossover design (crossover), and a minimum interval of 7 days (washout) between interventions. Skin biomechanical parameters such as distensibility (R0) and viscoelasticity (R6) were noninvasively evaluated by Cutometer before and after 0, 10, 20, and 30 min of intervention with therapeutic ultrasound and paraffin alone, as well as associated with negative pressure therapy of the skin (vacuum therapy). In this study, all groups showed increased distensibility (R0) in the period immediately after the application of the resources and a progressive reduction in the effects in the consecutive tests. Participants with skin grafts showed a decrease in viscoelasticity (R6) in all groups, except therapeutic paraffin and therapeutic ultrasound and vacuum massage. CONCLUSION: The biomechanical properties of grafted skin after a burn are altered after therapeutic intervention with ultrasound alone or associated with vacuum massage, such as intervention with paraffin associated with vacuum massage, for both parameters evaluated, skin distensibility (R0) and skin viscoelasticity (R6). However, the same did not occur for the intervention with isolated paraffin. There was no significant difference between the interventions therapeutic ultrasound and therapeutic paraffin.

Virulence Genes of Helicobacter pylori Increase the Risk of Premalignant Gastric Lesions in a Colombian Population.

Background: Genetic variability of Helicobacter pylori is associated with various gastrointestinal diseases; however, little is known about interaction with sociodemographic in the development of premalignant lesions in Colombian patients. Methods: An analytical study was conducted including cases (patients with gastric atrophy, intestinal metaplasia, and gastric dysplasia) and controls (patients with nonatrophic gastritis). Sociodemographic information was obtained using a questionnaire. Histopathological diagnosis was performed according to the Sydney System. The cagA and vacA genotypes were established using polymerase chain reaction in paraffin blocks. The effect of each variable on the study outcome (premalignant lesion) is presented as odds ratio (OR) and 95% CI. A p value of <0.05 was considered as statistically significant. Results: The vacA/s1m1 genotype increases the risk of developing premalignant lesions of the stomach (OR: 3.05, 95% IC: 1.57-5.91, p=0.001). Age and educational level showed a positive interaction with the s1m1 genotype (adjusted OR: 3.68, 95% CI: 1.73-7.82, p=0.001). The cagA genotype was not correlated to the development of premalignant lesions of the stomach (OR: 1.32, 95% CI: 0.90-1.94, p=0.151). Conclusions: The vacA genotype, age, and educational level are indicators of the risk of developing premalignant lesions of the stomach in the study population. Significance Statement. Genetic variability of H. pylori and sociodemographic information could be used to predict the risk of premalignant lesions in stomach in Colombian population.

Boid Inclusion Body Disease Is Also a Disease of Wild Boa Constrictors.

Reptarenaviruses cause boid inclusion body disease (BIBD), a potentially fatal disease, occurring in captive constrictor snakes boas and pythons worldwide. Classical BIBD, characterized by the formation of pathognomonic cytoplasmic inclusion bodies (IBs), occurs mainly in boas, whereas in pythons, for example, reptarenavirus infection most often manifests as central nervous system signs with limited IB formation. The natural hosts of reptarenaviruses are unknown, although free-ranging/wild constrictor snakes are among the suspects. Here, we report BIBD with reptarenavirus infection in indigenous captive and wild boid snakes in Costa Rica using histology, immunohistology, transmission electron microscopy, and next-generation sequencing (NGS). The snakes studied represented diagnostic postmortem cases of captive and wild-caught snakes since 1989. The results from NGS on archival paraffin blocks confirm that reptarenaviruses were already present in wild boa constrictors in Costa Rica in the 1980s. Continuous sequences that were de novo assembled from the low-quality RNA obtained from paraffin-embedded tissue allowed the identification of a distinct pair of reptarenavirus S and L segments in all studied animals; in most cases, reference assembly could recover almost complete segments. Sampling of three prospective cases in 2018 allowed an examination of fresh blood or tissues and resulted in the identification of additional reptarenavirus segments and hartmanivirus coinfection. Our results show that BIBD is not only a disease of captive snakes but also occurs in indigenous wild constrictor snakes in Costa Rica, suggesting boa constrictors to play a role in natural reptarenavirus circulation. IMPORTANCE The literature describes cases of boid inclusion body disease (BIBD) in captive snakes since the 1970s, and in the 2010s, others and ourselves identified reptarenaviruses as the causative agent. BIBD affects captive snakes globally, but the origin and the natural host of reptarenaviruses remain unknown. In this report, we show BIBD and reptarenavirus infections in two native Costa Rican constrictor snake species, and by studying archival samples, we show that both the viruses and the disease have been present in free-ranging/wild snakes in Costa Rica at least since the 1980s. The diagnosis of BIBD in wild boa constrictors suggests that this species plays a role in the circulation of reptarenaviruses. Additional sample collection and analysis would help to clarify this role further and the possibility of, e.g., vector transmission from an arthropod host.

Automated bone healing evaluation: New approach to histomorphometric analysis.

This study aimed to assess different approaches for bone healing evaluation on histological images and to introduce a new automatic evaluation method based on segmentation with distinct thresholds. We evaluated the hyperbaric oxygen therapy (HBO) effects on bone repair in type 1 diabetes mellitus rats. Twelve animals were divided into four groups (n = 3): non-diabetic, non-diabetic + HBO, diabetic, and diabetic + HBO. Diabetes was induced by intravenous administration of streptozotocin (50 mg/kg). Bone defects were created in femurs and HBO was immediately started at one session/day. After 7 days, the animals were euthanized, femurs were removed, demineralized, and embedded in paraffin. Histological sections were stained with hematoxylin and eosin (HE) and Mallory's trichrome (MT), and evaluated using three approaches: (1) conventional histomorphometric analysis (HE images) using a 144-point grid to quantify the bone matrix; (2) a semi-automatic method based on bone matrix segmentation to assess the bone matrix percentage (MT images); and (3) automatic approach, with the creation of a plug-in for ImageJ software. The time required to perform the analysis in each method was measured and subjected to Bland-Altman statistical analysis. All three methods were satisfactory for measuring bone formation and were not statistically different. The automatic approach reduced the working time compared to visual grid and semi-automated method (p < .01). Although histological evaluation of bone healing was performed successfully using all three methods, the novel automatic approach significantly shortened the time required for analysis and had high accuracy.

Inventory approach for short-chain chlorinated paraffins for the Stockholm Convention implementation in Brazil.

Chlorinated paraffins (CPs) are chemicals with multipurpose applications. Their global production has increased despite their adverse impacts on the environment and human health. In 2017, short-chain chlorinated paraffins (SCCPs) were listed as persistent organic pollutants (POPs) in the Stockholm Convention. Yet, specific exemptions were granted for their applications despite the recycling prohibition for products containing SCCPs. Therefore, we aimed to produce the first Brazilian inventory of SCCPs following its respective guidance to evaluate the applicability of the SCCP inventory guidance and to provide technical insights regarding SCCPs in the update of the Brazilian National Implementation Plan (NIP). Moreover, we performed a review of SCCP occurrence in Brazil to fulfil data gaps in the inventory development. We identified and consulted nationwide stakeholders and assessed foreign trade data of CPs and products that might contain CPs in relevant amounts. The Brazilian production of CPs was discontinued in 1994. However, CPs are still imported and used in the country. CPs have been mostly applied as plasticizers, flame retardants and lubricants in Brazil. The import of products containing CPs also pose a significant route of CP entrance into Brazil. Thus, the current end-of-life management of CP-containing products is a bottleneck towards the Convention implementation. The guidance application was feasible and useful despite the low engagement of stakeholders. To assess foreign trade of CPs and CP-containing products, we recommend the use of more specific tracking codes. Besides, the review of SCCP occurrence is not a demanded part for an inventory but was a useful complementation.

Meningoencephalitis caused by Bovine alphaherpesvirus 5 in Pernambuco, Brazil / [Meningoencefalite causada pelo Bovine alphaherpesvirus 5 em Pernambuco, Brasil]

Objetivou-se descrever a ocorrência do Bovine alphaherpesvirus 5 (BoHV5) como causa de meningoencefalite não supurativa em bovinos do estado de Pernambuco, Brasil. Para tanto, 32 amostras de sistema nervoso embebidas em parafina foram obtidas de animais acometidos por doenças neurológicas atendidos na Clínica de Bovinos de Garanhuns da Universidade Federal Rural de Pernambuco (CBG-UFRPE), entre 2012 e 2016. As amostras foram analisadas quanto à presença do gene da glicoproteína C do BoHV5 por reação em cadeia da polimerase (PCR). Dois animais (6,25%) tiveram resultado positivo à PCR, e sua análise de sequenciamento indicou 100% de similaridade para o BoHV5. Os resultados histopatológicos desses dois animais revelaram lesões multifocais de meningoencefalite não supurativa associada à polioencefalomalácia, presença de corpúsculos de inclusão basofílicos, infiltração de células de Gitter e presença de manguitos perivasculares. A PCR se mostra uma importante ferramenta para diferenciação das infecções por BoHV5 de outras enfermidades neurológicas de bovinos, especialmente a raiva.(AU)

Evaluación de la metilación del DNA en tejidos de cáncer colorrectal fijados en formalina y embebidos en parafina (FFPE) / Evaluation of DNA methylation in formalin-fixed, paraffin embedded colorectal cancer tissues (FFPE)

Resumen Las alteraciones en la metilación de dinucleótidos CpG en regiones promotoras es uno de los mecanismos epigenéticos implicados en cáncer que tiene uso potencial como biomarcador. Su evaluación, a partir de tejidos fijados en formalina y embebidos en parafina (FFPE), representa un gran desafío dadas la degradación parcial, el entrecruzamiento y las bajas cantidades del DNA obtenido. En esta nota técnica, describimos un protocolo para el estudio del estado de metilación del promotor distal del proto-oncogén K-RAS, a partir de varias muestras obtenidas de dos tejidos FFPE de cáncer colorrectal con antigüedad de 11 años. Se empleó un protocolo de conversión con bisulfito alternativo al usual; se usó una DNA polimerasa modificada y una PCR anidada y se optimizó la secuenciación directa del DNA convertido con bisulfito. Este protocolo podría ser aplicado para determinar estados de metilación en otros genes y tipos de cáncer en tejidos FFPE.

Abstract Alterations in the methylation of CpG dinucleotides in promoter regions is one of the epigenetic mechanisms involved in cancer that has potential use as a biomarker. Its evaluation from formalin-fixed and paraffin-embedded (FFPE) tissues represents a great challenge given the partial degradation, crosslinking, and low amounts of the obtained DNA. In this technical note we describe a protocol for the study of the methylation status of the distal promoter of the K-RAS proto-oncogene from several samples obtained from two 11-years old FFPE tissues of colorectal cancer. An alternative bisulfite conversion protocol to the usual one was used; a modified DNA polymerase and a nested PCR were used and the direct sequencing of the converted DNA with bisulfite was optimized. This protocol could be applied to determine methylation states in other genes and types of cancer.

Pyrolysis of oil sludge from the offshore petroleum industry: influence of different mesoporous zeolites catalysts to obtain paraffinic products.

Pyrolysis of oil sludge from the petroleum industry in contact with three mesoporous zeolite catalysts (CBV 720, 760 and 780) was carried out at 450°C to obtain oil rich in paraffin. The properties of the catalysts were characterized by XRD, XRF, NH3-TPD, FT-IR, TGA and nitrogen ad/desorption isotherms, while the pyrolysis oil was analysed by GC-MS. The products obtained in the presence of mesoporous zeolites showed selectivity for conversion of light hydrocarbons with decreased content of aromatic compounds. The homogeneous porosity distribution of the CBV 780 was the determining factor in catalytic pyrolysis. The residue could be treated by pyrolysis using mesoporous zeolite. The use of this catalyst produced 56% oil fraction with the highest yield of light hydrocarbons (96%). Compared with the thermal pyrolysis of this waste, the use of mesoporous zeolitic catalysts increased the production of light hydrocarbons and reduced the production of aromatic compounds in the pyrolysis oil from sludge.

The modified method of luxol fast blue for paraffin-embedded myelin sheath staining / El método modificado de luxol fast blue para la tinción de mielina fijada en parafina

SUMMARY: Histological techniques are the study of animal and human tissues through staining and examining them under a microscope. To demonstrate the axonal degeneration and demyelination in histological studies, the Luxol Fast Blue staining is gold standard techniques. In this study, a new histochemical method based on modified Luxol Fast Blue for the staining of the myelin sheath in sciatic nerve tissues described. The sciatic nerves of rats were removed and then the sciatic nerve was immersed in 10 % formaldehyde for one week and embedded in paraffin block. Next, thin sections (5 µm) were cut, using a microtome and stained with conventional and modified Luxol Fast Blue. Our results showed that a new method of modified Luxol Fast Blue staining can accurately identify the myelin in the sciatic nerve fibers. The current study showed that the Luxol Fast Blue combination with Light Green has a good effect on myelin coloration, and the results of this study are comparable to LFB combination with Sirius red.

RESUMEN: Las técnicas histológicas son el estudio de tejidos animales y humanos mediante tinción y examen bajo un microscopio. Para demostrar la degeneración axonal y la desmielinización en estudios histológicos, la tinción Luxol Fast Blue es una técnica estándar de oro. En este estudio, se describe un nuevo método histoquímico basado en Luxol Fast Blue modificado para la tinción de mielina en los tejidos del nervio ciático. Se seccionaron los nervios ciáticos de ratas y luego el nervio ciático se sumergió en formaldehído al 10 % durante una semana y se fijó en bloque de parafina. Posteriormente, se cortaron secciones delgadas (5 µm) usando un microtomo y se tiñeron con Luxol Fast Blue convencional y modificado. Nuestros resultados mostraron que un nuevo método de tinción Luxol Fast Blue modificado puede identificar con precisión la mielina en las fibras del nervio ciático. El estudio actual mostró que la combinación Luxol Fast Blue con Light Green es un buen efecto sobre la coloración de mielina, y los resultados de este estudio son comparables a la combinación LFB con Sirius red.

Fluorescence spectroscopy on paraffin-preserved human liver samples to classify several grades of fibrosis.

Nowadays, it is well established that biopsy is the gold standard for medical diagnosis of liver disease; however, recent studies have shown numerous discrepancies in biopsy assessment, even when it is evaluated by senior pathologists. Fluorescence spectroscopy is a tool that has been of utility in the diagnosis of different diseases based on biopsy analysis. Thus, fluorescence study of liver samples with five different degrees of fibrosis is presented. Paraffin-preserved human liver tissue was provided on white plastic cassettes by the Hospital General de Mexico "Dr. Eduardo Liceaga". Specimens were diagnosed by two independent-senior pathologists in a double-blind test and classified into five different groups: F0, F1, F2, F3, and F4, according to the METAVIR scale for liver fibrosis. Fluorescence spectroscopy measurements were performed using three different excitation wavelengths: 385, 405, and 450 nm. Besides, diffuse reflectance spectroscopy (DRS) measurements were taken with white light to determine morphological changes in the tissue and to compare the results with medical diagnosis. The spectral analysis at excitation wavelengths of 385 nm and 405 nm showed poor correlation with medical diagnosis. Likewise, in order to discard all possible error-sources involved in the measurements, an exhaustive study was carried out; it included the determination of the fluorescence noise produced by paraffin, cassette, and the tissue itself. At 450 nm excitation wavelength, no fluorescence by the cassette was detected and noise-subtraction methods were not required, this allows a high correlation of hepatic fibrosis stages between pathological diagnosis and spectroscopic analysis. For this excitation wavelength, 89.87% correlation with DRS measurements and 82.00% with medical diagnosis were obtained. This work demonstrates that fluorescence spectroscopy using 450 nm excitation wavelength might work as a complementary tool to grade hepatic fibrosis in human liver specimens.

O uso da técnica de avaliação intra-operatória de margens cirúrgicas por congelação "en face" no manejo de carcinomas cutâneos: resultados oncológicos e relação com os resultados da avaliação em parafina / The use of the intra-operative evaluation technique of surgical margins by "en face" frozen section in the management of skin carcinomas: oncological results and its correlation with the results of the evaluation in paraffin

Introdução: Os carcinomas cutâneos basocelular e espinocelular são os tipos mais comuns de câncer no mundo. A avaliação intra-operatória de margens cirúrgicas por exame de congelação vem sendo largamente utilizada para assegurar margem livre de doença e reconstrução primária satisfatória. A técnica de congelação intra-operatória "en face" avalia todas as margens periféricas e profunda durante a ressecção de carcinomas cutâneos, sendo uma técnica de baixo tempo de execução, com rápida curva de aprendizado, de fácil execução e baixo custo. Objetivo: demonstrar a rotina de avaliação intra-operatória de margens de ressecção de lesões cutâneas através da congelação "en face", com ênfase em sua execução, segurança e relação com o resultado final do exame anatomopatológico. Avaliar a taxa de recorrência de carcinomas cutâneos após a excisão da lesão pela técnica "en face". Métodos: Análise retrospectiva dos pacientes submetidos a exérese cirúrgica de carcinomas cutâneos pelo Núcleo de Câncer de Pele do AC Camargo Câncer Center, entre janeiro a dezembro de 2013. Foram avaliados dados clínicos, epidemiológicos, de anatomia patológica e de tratamento. Os resultados do exame intra-operatório de congelação "en face" foram comparados com o resultado final anatomopatológico após processamento histopatológico convencional com confecção de blocos de parafina. Resultados: o número de pacientes foi de 397, com exérese de 542 tumores cutâneos. Em relação ao gênero; 201 masculino e 196 feminino. A idade média foi de 64 anos. Os tumores foram localizados em 87,8 % na cabeça e pescoço, 9,4 % em membros e 2,8 % no tronco. O carcinoma basocelular correspondeu a 79,7 % dos casos (432 lesões) e o carcinoma espinocelular correspondeu a 20,3 % (110 lesões). Apenas 6,7% das lesões apresentaram complicação cirúrgica (infecção do sítio cirúrgico e deiscência da ferida operatória foram as mais comuns). O seguimento mediano dos pacientes foi de 38 meses. A recidiva tumoral total ocorreu em 1,4% dos pacientes. O resultado da congelação intra-operatória "en face" foi concordante com o resultado final do exame anatomopatológico (exame de parafina) em 98% das lesões. Conclusão: A técnica de congelação intra-operatória "en face" é uma técnica rápida, confiável e segura para garantir margens cirúrgicas negativas de tumor para carcinomas cutâneos. Além, constitui-se em uma técnica com baixa recidiva tumoral

Introduction: Basal cell and squamous cell carcinomas are the most common types of cancer in the world. The intraoperative evaluation of surgical margins by frozen section exam has been widely used to ensure a disease-free margin and satisfactory primary reconstruction. The "en face" intraoperative frozen section technique assesses all peripheral and deep margins during the resection of skin carcinomas, being a technique with a low execution time, with a fast learning curve, easy to perform and low cost. Objective: Demonstrate the routine of intraoperative evaluation of skin lesion resection margins through "en face" frozen section technique, with emphasis on its execution, safety and correlation with the result of the anatomopathological exam. Evaluate the rate of recurrence of skin carcinomas after excision of the lesion using the "en face" technique. Methods: Retrospective analysis of patients undergoing surgical excision of skin carcinomas by the Skin Cancer Center of the AC Camargo Cancer Center, between January 2013 and December 2013. Clinical, epidemiological, pathological anatomy and treatment data were evaluated. The results of the intraoperative "en face" frozen section exam were compared with the final anatomopathological result that were obtained after conventional histopathological processing with the manufacture of paraffin blocks. Results: 397 patients were included in this study, with a total of 542 skin tumors excisions. Regarding gender: 201 male and 196 female. The average age was 64 years. Tumors were found in 87, 8% of the head and neck, 9,4% in the limbs and 2,8% in the trunk. Basal cell carcinoma corresponded to 79,7% of cases (432 lesions) and squamous cell carcinoma corresponded to 20,3% (110 lesions). Only 6,7% of the lesions had surgical complications (surgical site infection and surgical wound dehiscence were the most common). The median follow-up of patients was 38 months. Tumor recurrence occurred in 1,4% of patients. The result of intraoperative "en face" frozen section was in agreement with the result of the anatomopathological examination (paraffin examination) in 98% of the lesions. Conclusion: The intraoperative "en face" frozen section technique is a fast, reliable and safe technique to ensure negative tumor surgical margins for skin carcinomas. In addition, it is a technique with low tumor recurrence

Chlorinated paraffins (CPs) in salmon sold in southern Germany: Concentrations, homologue patterns and relation to other persistent organic pollutants.

Chlorinated paraffins (CPs) are complex mixtures of persistent contaminants present throughout the aquatic food web. In this study 122 farmed and 11 wild salmon samples were collected over the course of four years (2014-2017). The ratio of short-chain CP and medium-chain CP and the corresponding homologue patterns were determined by means of gas chromatography (GC) with high resolution, accurate mass Orbitrap mass spectrometry (MS) technology. Characteristic patterns were observed, enabling differentiation between European and non-European (Chilean) samples. Concentration ranges of short-chain CPs (0.97-170 ng/g ww) and medium-chain CPs (1.1-79 ng/g ww) were similarly widespread over three orders of magnitude. Yet, both the mean and median concentrations of MCCPs were usually higher than those of the SCCP. CP levels were generally higher than those of marker polychlorinated biphenyls (PCBs) and hexabromocyclododecanes (HBCDDs). An age- and gender-dependent estimated intake range of 4.6-35 ng/kg bw/week for short and medium-chain CPs via the consumption of salmon was calculated for adults in Germany.

Accuracy of quantitative polymerase chain reaction in samples of frozen and paraffin-embedded healthy skin for the diagnosis of canine visceral leishmaniasis / Acurácia da reação em cadeia da polimerase quantitativa em amostras de pele íntegra congelada e parafinada no diagnóstico da leishmaniose visceral canina

The purpose of the present work was to evaluate the accuracy of quantitative polymerase chain reaction (qPCR) performed on samples of fresh frozen tissue (FT) and formalin-fixed, paraffin-embedded (FFPE) healthy skin. This is a validation study conducted with samples from 46 dogs from an endemic area in Brazil. After sample collection, DNA extractions were conducted using commercial kits and qPCR was oriented to kinetoplast DNA (kDNA) targets of the Leishmania infantum species. The results obtained for the FFPE samples showed 63.6% sensitivity and 77.1% specificity, whereas those obtained for the FT samples showed 100% and 48.6%, respectively. Poor agreement was observed for the results of the qPCR technique with FT and FFPE samples. Our results suggest freezing as the most suitable conservation method for the formation of sample databases considering DNA recovery.(AU)

O objetivo deste trabalho foi avaliar a acurácia da PCR quantitativa (qPCR) realizada em amostras de pele íntegra congelada (FT) e parafinada (FFPE). Trata-se de um estudo de validação, com amostras provenientes de 46 cães de uma área endêmica no Brasil. Após as coletas de amostras, as extrações de DNA foram realizadas utilizando-se kits comerciais, e a qPCR foi orientada para alvos do kDNA da espécie Leishmania infantum. Os resultados obtidos para as amostras FFPE foram 63,6% de sensibilidade e 77,1% de especificidade; para as amostras FT, 100% e 48,6%, respectivamente. A concordância dos resultados da técnica de qPCR com amostras FT e FFPE foi pobre. Os resultados sugerem que o congelamento é o método mais adequado de conservação para banco de amostras para recuperação de DNA.(AU)

Accuracy of quantitative polymerase chain reaction in samples of frozen and paraffin-embedded healthy skin for the diagnosis of canine visceral leishmaniasis / Acurácia da reação em cadeia da polimerase quantitativa em amostras de pele íntegra congelada e parafinada no diagnóstico da leishmaniose visceral canina

The purpose of the present work was to evaluate the accuracy of quantitative polymerase chain reaction (qPCR) performed on samples of fresh frozen tissue (FT) and formalin-fixed, paraffin-embedded (FFPE) healthy skin. This is a validation study conducted with samples from 46 dogs from an endemic area in Brazil. After sample collection, DNA extractions were conducted using commercial kits and qPCR was oriented to kinetoplast DNA (kDNA) targets of the Leishmania infantum species. The results obtained for the FFPE samples showed 63.6% sensitivity and 77.1% specificity, whereas those obtained for the FT samples showed 100% and 48.6%, respectively. Poor agreement was observed for the results of the qPCR technique with FT and FFPE samples. Our results suggest freezing as the most suitable conservation method for the formation of sample databases considering DNA recovery.(AU)

O objetivo deste trabalho foi avaliar a acurácia da PCR quantitativa (qPCR) realizada em amostras de pele íntegra congelada (FT) e parafinada (FFPE). Trata-se de um estudo de validação, com amostras provenientes de 46 cães de uma área endêmica no Brasil. Após as coletas de amostras, as extrações de DNA foram realizadas utilizando-se kits comerciais, e a qPCR foi orientada para alvos do kDNA da espécie Leishmania infantum. Os resultados obtidos para as amostras FFPE foram 63,6% de sensibilidade e 77,1% de especificidade; para as amostras FT, 100% e 48,6%, respectivamente. A concordância dos resultados da técnica de qPCR com amostras FT e FFPE foi pobre. Os resultados sugerem que o congelamento é o método mais adequado de conservação para banco de amostras para recuperação de DNA.(AU)