Does hyperbaric oxygenation have a protective effect on random skin flaps?: an immunohistochemical study of cellular apoptosis and vascular endothelial growth factor

BACKGROUND: Hyperbaric oxygenation (HBO) therapy aims to increase oxygen tissue pressure by at least 10 times and decrease the adverse effects of ischemia. The aim of this study was to investigate the effect of HBO on the immunohistochemical expressions of caspase 3 and vascular endothelial growth factor (VEGF) in random flaps in rats. METHODS: Thirty-two male Wistar rats were randomly divided into 4 groups: the sham group (GS), the N-acetylcysteine group (GNAC), the HBO group, and the HBO + N-acetylcysteine group. A rectangular skin flap (2 × 8 cm) was dissected from the dorsal muscle layer, and a cranial pedicle was preserved. A polyethylene film was placed on the muscle layer, and the flap was fixed in the original site. On the eighth day, biopsy samples (2 × 1 cm) of the entire thickness of the proximal, medial, and cranial areas as well as of the site outside the flap, which was used as a control, were collected. RESULTS: VEGF expression in the skin layers and vessels was not significantly different between the groups. The number of apoptotic cells was significantly increased in the area of the flap in all groups. The highest increase was noted in the GS and GNAC groups. HBO significantly reduced the number of caspase 3-positive cells in the skin layers and vessels of the 3 areas. CONCLUSIONS: HBO was associated with decreased apoptosis. VEGF expression in the skin layers and vessels did not differ significantly. The results suggest that oxygen diffusion through the interstitial space was the determining factor for the positive effect of HBO on the decrease in apoptosis.INTRODUÇÃO: A oxigenação hiperbárica (OHB) tem por objetivo aumentar em pelo menos 10 vezes a pressão tecidual de oxigênio, diminuindo os efeitos deletérios da isquemia. O objetivo deste estudo é investigar o papel da oxigenação hiperbárica na expressão imuno-histoquímica da caspase 3 e do fator de crescimento endotelial vascular (VEGF) em retalhos randômicos em ratos. MÉTODO: Trinta e dois ratos Wistar machos foram divididos aleatoriamente em quatro grupos: grupo sham (GS), grupo N-acetilcisteína (GNAC), grupo OHB (GOHB) e grupo OHB + N-acetilcisteína (GHN). Um retalho de pele retangular (2 cm x 8 cm) foi dissecado a partir da camada muscular dorsal, preservando um pedículo cranial. Uma lâmina de polietileno foi colocada sobre a camada muscular e fixou-se o retalho no local original. No 8º dia, foram coletadas biópsias (2 cm x 1 cm) de espessura total das áreas proximal, média e cranial e de um local fora do retalho, que serviu como área de controle. RESULTADOS: A expressão de VEGF nas camadas da pele e nos vasos não apresentou diferenças significativas entre os grupos. As células apoptóticas estavam significativamente aumentadas na área central do retalho em todos os grupos. O maior aumento ocorreu nos grupos GS e GNAC. A OHB diminuiu significativamente o número de células caspase 3 positivas nas camadas da pele e nos vasos das três áreas. CONCLUSÕES: A OHB foi associada a expressão reduzida de apoptose. A expressão de VEGF em camadas da pele e vasos não demonstrou diferença significativa. Os resultados sugerem que a difusão do oxigênio através do espaço intersticial foi o fator determinante para os resultados mais favoráveis da OHB na diminuição da expressão de apoptose.Sociedade Brasileira de Cirurgia PlásticaUniversidade Católica de Pelotas Departamento de CirurgiaUniversidade Federal de São Paulo (UNIFESP) Departamento de CirurgiaUniversidade Federal de PelotasUniversidade Federal de Pelotas Liga Acadêmica de Cirurgia PlásticaUNIFESP, Depto. de CirurgiaSciEL

Effects of hyperbaric oxygenation and N-acetylcysteine on the survival of random-pattern skin flaps in rats

BACKGROUND: Advances in plastic surgery techniques have enabled reconstruction of extensive wound damage, especially through the use of random flaps. However, the limiting factor for the use of these flaps is the unpredictable blood supply, which may produce irreversible damage to the microcirculation and result in partial or complete flap necrosis, making the wound more susceptible to infection. Therefore, improvement of random flaps, especially in the distal extremity, has been an essential goal for the success of this technique. The objective of this study was to investigate the effects of hyperbaric oxygenation (HBO), N-acetylcysteine (NAC), and the combination of both (HBO + NAC) on the degree of necrosis in modified McFarlane random skin flaps on Wistar rats. METHODS: A total of 32 male Wistar rats were randomly divided into a sham treatment group (SG, n = 8), N-acetylcysteine group (NACG, n = 8), hyperbaric oxygenation group (HBOG, n = 8), and hyperbaric oxygenation plus N-acetylcysteine group (HNG, n = 8). Modified McFarlane random flaps were created in the dorsal region of the rats. RESULTS: The average area of the flaps exhibiting necrosis was 18.3%, 24.3%, 12.6%, and 14.9%, in the SG, NACG, HBOG, and HNG, respectively. The necrotic areas in the HBOG and HNG were significantly smaller than that in the NACG. CONCLUSIONS: HBO treatment was associated with a reduction in the area of necrosis in the skin flaps. NAC treatment alone gave poor results. The use of HBO and NAC in combination did not improve the outcome compared with the use of HBO alone. The findings suggest that oxygen diffusion through the interstitial space was the factor responsible for the favorable results of HBO.INTRODUÇÃO: Os avanços das técnicas em cirurgia plástica permitiram a reconstrução de extensos defeitos causados por ferimentos, entre as quais destaca-se a utilização dos retalhos randômicos. No entanto, o fator limitante para a utilização desses retalhos é a imprevisibilidade de sua vascularização distal, o que poderá ocasionar danos irreversíveis à microcirculação, resultando em necrose parcial ou completa do retalho, tornando a ferida mais suscetível a infecção. Portanto, melhorar a viabilidade do retalho randômico, principalmente em sua extremidade distal, tem sido uma meta importante para o sucesso dessa técnica. O objetivo deste estudo foi investigar o papel da oxigenação hiperbárica (OHB), da N-acetilcisteína (NAC) e da associação de ambas (OHB + NAC) na área de necrose em retalhos randômicos modificados de McFarlane em pele de ratos Wistar. MÉTODO: No total, 32 ratos Wistar machos foram divididos aleatoriamente em grupo Sham (GS, n = 8), grupo N-acetilcisteína (GNAC, n = 8), grupo oxigênio hiperbárico (GOHB, n = 8) e grupo oxigênio hiperbárico + N-acetilcisteína (GHN, n = 8). Sob anestesia geral, foi executado um retalho randômico modificado de McFarlane na região dorsal dos ratos. RESULTADOS: A necrose média foi de 18,3%, 24,3%, 12,6% e 14,9%, respectivamente, nos grupos GS, GNAC, GOHB e GHN. Os grupos GOHB e GHN apresentaram diferença significativa quando comparados ao grupo GNAC. CONCLUSÕES: A OHB está associada a redução da área de necrose do retalho cutâneo. A NAC foi associada a maus resultados quando usada isoladamente. A associação dos dois procedimentos, OHB e NAC, não potencializou os resultados favoráveis observados com o uso da OHB isoladamente. As descobertas sugerem que a difusão de oxigênio através do espaço intersticial foi o fator determinante de resultados mais favoráveis da OHB.Universidade Federal de São Paulo (UNIFESP) Departamento de CirurgiaUNIFESP, Depto. de CirurgiaSciEL

Tratamento da ptose mamária bilateral e do pectus excavatum através da mesma incisão no mesmo tempo cirúrgico

CONTEXT: Congenital deformities of the anterior thoracic wall are characterized by unusual development of the costal cartilages. All these medical conditions are frequently associated with a variety of breast deformities. Several surgical techniques have been described for correcting them, going from sternochondroplasty to, nowadays, minimally invasive techniques and silicone prosthesis implantation. CASE REPORT: The present article reports the case of a young female patient who presented bilateral mammary ptosis and moderate pectus excavatum that caused a protrusion between the eighth and the tenth ribs and consequent esthetic disharmony. The proposed surgical treatment included not only subglandular breast implants of polyurethane, but also resection of part of the rib cartilage and a bone segment from the eighth, ninth and tenth ribs by means of a single submammary incision in order to make the scar minimally visible. Correction through a single incision benefited the patient and provided an excellent esthetic result. CONCLUSIONS: The techniques used to repair bilateral mammary ptosis and pectus excavatum by plastic and thoracic surgery teams, respectively, have been shown to be efficient for correcting both deformities. An excellent esthetic and functional result was obtained, with consequent reestablishment of the patient's self-esteem.CONTEXTO: Deformidades congênitas da parede torácica anterior são caracterizadas pelo desenvolvimento anormal das cartilagens costais. Todas essas afecções são frequentemente associadas com as mais diferentes deformidades da mama. Várias técnicas cirúrgicas têm sido utilizadas para a correção desde as esternocondroplastias até, atualmente, técnicas minimamente invasivas e próteses de silicone. RELATO DE CASO: O presente artigo relata o caso de uma paciente jovem que apresentava ptose mamária bilateral e uma forma moderada de pectus excavatum que ocasionava uma protrusão entre a oitava e a décima costelas, tendo como consequencia a desarmonia estética. O tratamento cirúrgico proposto incluiu, além de implantes mamários sub-glandulares de poliuretano, ressecção de parte da cartilagem da costela e parte do segmento ósseo da oitava, nona e décima costelas por uma única incisão sub-mamária para tornar a cicatriz minimamente visível. A correção por meio de uma única incisão beneficiou a paciente, proporcionando excelente resultado estético. CONCLUSÕES: As técnicas utilizadas para reparação da ptose mamária bilateral e do pectus excavatum pelas equipes de cirurgia plástica e torácica, respectivamente, demonstraram-se eficazes para correção de ambas as deformidades. Foi obtido ótimo resultado estético e funcional com consequente retomada da auto-estima da paciente.Universidade Católica de PelotasUniversidade Federal de PelotasUniversidade Federal de São Paulo (UNIFESP) Department of Surgery Division of Operative Technique and Experimental SurgeryUNIFESP, Department of Surgery Division of Operative Technique and Experimental SurgerySciEL

Especificidade e sensibilidade de rastreamento para lesões cutâneas pré-malignas e malignas

OBJECTIVE: The incidence of melanoma is increasing worldwide, prevalence of malignant epithelial tumors is high and early diagnosis reduces significantly the morbi-mortality of these diseases. The purpose of the study is to estimate the prevalence of pre-malignant and malignant skin lesions and to determine the sensitivity and specificity of screening tests. METHODS: A cross-sectional population-based study was carried out using 48 census tracts randomly selected from urban zone of southern, Brazil. A total of 2,112 dwellings were visited and 1,292 individuals aged 50 years or more were interviewed. The questionnaire consisted of specific questions about new skin lesions in the last six months and/or the presence of lesions on exposed areas. Those who answered affirmatively were referred to the university's outpatient clinic for medical skin examination (gold standard). For assessing specificity the same doctors investigated a sub-sample of those who replied negatively to the questionnaire. RESULTS: The prevalence of pre-malignant and malignant skin lesions was 20.7%. The screening sensitivity was 20.1%, specificity 86.9%, positive predictive value 29%, negative predictive value 80.4%, and accuracy 72.9%. Using different cut-off points, the maximum sensitivity value was 38.8% and specificity remained almost the same. CONCLUSIONS: The study showed a high prevalence of skin lesions both pre-malignant and malignant in adults. Skin lesion screening revealed low sensitivity and unsatisfactory specificity, regardless the cut-off points set.OBJETIVO: O melanoma tem incidência crescente, sendo que a prevalência dos tumores malignos epiteliais é alta, e o diagnóstico precoce contribui significativamente para a redução da morbimortalidade dessas doenças. O objetivo da pesquisa é medir a prevalência das lesões cutâneas pré-malignas e malignas e determinar a sensibilidade e a especificidade de um rastreamento para essas lesões. MÉTODOS: Foi realizado um estudo transversal de base populacional com escolha aleatória de 48 setores censitários da zona urbana de Pelotas, RS, Brasil. Um total de 2.112 domicílios foram visitados, sendo entrevistadas 1.292 pessoas de 50 anos de idade ou mais. O rastreamento possuía questões específicas sobre o surgimento de lesões de pele nos últimos seis meses e/ou a presença de lesões em áreas expostas. Os que responderam afirmativamente foram encaminhados ao exame médico. Também foi examinada uma subamostra daqueles que haviam respondido negativamente às questões do rastreamento. RESULTADOS: A prevalência corrigida das lesões cutâneas pré-malignas e malignas foi de 20,7%. A sensibilidade do rastreamento foi de 20,1%, a especificidade, de 86,9%, o valor preditivo positivo, de 29%, o valor preditivo negativo, de 80,4%, e acurácia, de 72,9%. Com diferentes pontos de corte, o valor máximo da sensibilidade atingiu 38,8%, e a especificidade não se alterou significativamente. CONCLUSÕES: O estudo demonstrou alta prevalência de lesões cutâneas pré-malignas e malignas em adultos. O rastreamento para essas lesões mostrou baixa sensibilidade e especificidade inferior ao desejado, independentemente dos pontos de corte

Sound localization: the relevance of interaural differences in auditory thresholds

OBJETIVO: Esclarecer a relação das diferenças entre os limiares auditivos das orelhas direita e esquerda com o percentual de erros e acertos na localização de fontes sonoras em ambientes reverberantes. MÉTODOS: Foram examinados 56 voluntários, sendo 33 homens e 23 mulheres, média de idade de 26,6 anos, submetidos aos seguintes testes: otoscopia, audiometria tonal, imitanciometria e emissões otoacústicas. Todos os voluntários apresentaram audição dentro dos padrões de normalidade. Posteriormente, os indivíduos foram submetidos ao teste de localização sonora espacial, onde foram utilizadas ondas quadradas com freqüências fundamentais centradas em 500 Hz, 2000 Hz e 4000 Hz. Os estímulos foram apresentados quinze vezes em cada uma das treze posições espaciais do aparelho utilizado, em cada uma das freqüências escolhidas. Assim, foram apresentados 585 estímulos, no total, por pessoa. RESULTADOS: Na amostra estudada, encontrou-se como resultado, idade entre 18 e 50 anos, média da diferença dos limiares auditivos entre as orelhas de 6,81 dB e percentual de acertos na localização sonora dentro dos padrões normais. A correlação entre as diferenças interaurais e os acertos na localização, no entanto, não foi significativa. CONCLUSÕES: O presente estudo demonstrou que, em pessoas com audição normal, as variações dos limiares auditivos e as diferenças entre as orelhas até 10 dB não interferem na localização de fontes sonoras. _________________________________________________________________________________________ ABSTRACT: PURPOSE: To relate the differences between left and right ears' auditory thresholds and rate of correct/incorrect responses in sound localization tasks placed in reverberant environments. METHODS: The following tests were carried out: otoscopy, pure tone audiometry, impedanciometry and otoacoustic emissions. All 56 volunteers presented normal hearing results in all tests. After that, the volunteers were submitted to a sound localization test, in which square waves of 500 Hz, 2000 Hz and 4000 Hz were used. Stimuli were presented fifteen times in each one of the thirteen space positions of the device used, for each frequency tested. Therefore, a total number of 585 stimuli were presented for each subject. RESULTS: Data analysis showed that the sample had subjects with ages between 18 and 50 years, the average difference between right and left ears' auditory thresholds was 6,81 dB, and percentage of correct answers on the sound localization test was within normal values. No significant correlations were found between interaural differences and localization abilities. CONCLUSIONS: The present study showed that, for people with normal hearing, the auditory thresholds variations and interaural differences until 10 dB do not interfere on sound localization

A risk calculator to predict adult Attention-deficit/Hyperactivity disorder::Generation and external validation in three birth cohorts and one clinical sample.

AimFew personalised medicine investigations have been conducted for mental health. We aimed to generate and validate a risk tool that predicts adult attention-deficit/hyperactivity disorder (ADHD).MethodsUsing logistic regression models, we generated a risk tool in a representative population cohort (ALSPAC - UK, 5113 participants, followed from birth to age 17) using childhood clinical and sociodemographic data with internal validation. Predictors included sex, socioeconomic status, single-parent family, ADHD symptoms, comorbid disruptive disorders, childhood maltreatment, ADHD symptoms, depressive symptoms, mother's depression and intelligence quotient. The outcome was defined as a categorical diagnosis of ADHD in young adulthood without requiring age at onset criteria. We also tested Machine Learning approaches for developing the risk models: Random Forest, Stochastic Gradient Boosting and Artificial Neural Network. The risk tool was externally validated in the E-Risk cohort (UK, 2040 participants, birth to age 18), the 1993 Pelotas Birth Cohort (Brazil, 3911 participants, birth to age 18) and the MTA clinical sample (USA, 476 children with ADHD and 241 controls followed for 16 years from a minimum of 8 and a maximum of 26 years old).ResultsThe overall prevalence of adult ADHD ranged from 8.1 to 12% in the population-based samples, and was 28.6% in the clinical sample. The internal performance of the model in the generating sample was good, with an area under the curve (AUC) for predicting adult ADHD of 0.82 (95% confidence interval (CI) 0.79-0.83). Calibration plots showed good agreement between predicted and observed event frequencies from 0 to 60% probability. In the UK birth cohort test sample, the AUC was 0.75 (95% CI 0.71-0.78). In the Brazilian birth cohort test sample, the AUC was significantly lower -0.57 (95% CI 0.54-0.60). In the clinical trial test sample, the AUC was 0.76 (95% CI 0.73-0.80). The risk model did not predict adult anxiety or major depressive disorder. Machine Learning approaches did not outperform logistic regression models. An open-source and free risk calculator was generated for clinical use and is available online at https://ufrgs.br/prodah/adhd-calculator/.ConclusionsThe risk tool based on childhood characteristics specifically predicts adult ADHD in European and North-American population-based and clinical samples with comparable discrimination to commonly used clinical tools in internal medicine and higher than most previous attempts for mental and neurological disorders. However, its use in middle-income settings requires caution

Water’s quality and environmental conditions of the hydric resources in Grajaú-MA

Water is the essential element to develop and maintaining life, that is why the adoption of means of conservation of this essential resource is necessary. In Brazil, the ordinance No. 2914, from December 12th, 2011, of the Ministry Of Health establishes microbiological parameters, which determinate its quality, verifying its potability in order not to offer health risks. The research analyzed five samples from two different wells, placed in the same district of Grajaú-MA. The physical-chemical conditions were analyzed by the following parameters: total alkalinity, chlorides, total hardness, pH, iron, ammonia, chlorine, oxygen consumed, water turbidity by quick tests with the potability kit ALFAKIT and the microbiological conditions by the methodology of the multiple tubes based on the most probable number (MPN), besides seedlings on selective culture means. The results obtained in this research show that the samples of groundwater from five analyzed spots do not match the legislation, because they do not fit to the potability standards. This way, new analysis must be made, mainly microbiological and biochemical tests, to, this time on, adopt means that allow a proper treatment to this water that is used by the local communities.

SEROLOGICAL DETECTION OF HEPATITIS A VIRUS IN FREE-RANGING NEOTROPICAL PRIMATES (Sapajus spp., Alouatta caraya) FROM THE PARANÁ RIVER BASIN, BRAZIL

Nonhuman primates are considered as the natural hosts of Hepatitis A virus (HAV), as well as other pathogens, and can serve as natural sentinels to investigate epizootics and endemic diseases that are of public health importance. During this study, blood samples were collected from 112 Neotropical primates (NTPs) (Sapajus nigritus and S. cay, n = 75; Alouatta caraya, n = 37) trap-captured at the Paraná River basin, Brazil, located between the States of Paraná and Mato Grosso do Sul. Anti-HAV IgG antibodies were detected in 4.5% (5/112) of NTPs, specifically in 6.7% (5/75) of Sapajus spp. and 0% (0/37) of A. caraya. In addition, all samples were negative for the presence of IgM anti-HAV antibodies. These results suggest that free-ranging NTPs were exposed to HAV within the geographical regions evaluated