Lymphaticovenous anastomosis in rabbits: A novel live experimental animal model for supermicrosurgical training.

BACKGROUND: Lymphaticovenous anastomosis is widely used in lymphedema management. Although its effectiveness in reducing edema in patients can be clinically observed, evaluating the long-term outcomes of this technique can be complex. This study established an animal model to assess the outcomes of lymphaticovenous anastomosis technique at 15 and 30-days post-surgery using indocyanine green lymphography, Patent Blue V dye injection, and histopathological examination. METHODS: An experimental model was established in the hindlimbs of 10 rabbits using the popliteal vein and afferent lymphatic vessels in the popliteal area. The subjects were divided into two groups: the first group (n = 5) underwent patency assessment at 0 and 15 days, and the second group (n = 5) at 0 and 30-days, resulting in 20 anastomoses. Patency was verified at 0, 15, and 30-days using indocyanine green lymphography and Patent Blue V injection. Histopathological examinations were performed on the collected anastomosis samples. RESULTS: The patency rate was 90% (19/20) initially, 60% (6/10) at 15 days post-surgery, and 80% (8/10) at 30-days. The average diameter of lymphatic vessels and veins was 1.0 mm and 0.8 mm, respectively. The median number of collateral veins was 3; the median surgical time was 65.8 min. Histopathology revealed minimal endothelial damage and inflammatory responses due to the surgical sutures, with vascular inflammation and thrombosis in a single case. Local vascular neoformations were observed. CONCLUSION: This study highlights the reliability and reproducibility of using rabbits as experimental models for training in lymphaticovenous anastomosis technique owing to the accessibility of the surgical site and dimensions of their popliteal vasculature.

Popliteal Vascular Lymph Node Resection in the Rabbit Hindlimb for Secondary Lymphedema Induction.

Lymphedema is a common condition often associated with cancer and its treatment, which leads to damage to the lymphatic system, and current treatments are mostly palliative rather than curative. Its high incidence among oncologic patients indicates the need to study both normal lymphatic function and pathologic dysfunction. To reproduce chronic lymphedema, it is necessary to choose a suitable experimental animal. Attempts to establish animal models are limited by the regenerative capacity of the lymphatic system. Among the potential candidates, the rabbit hindlimb is easy to handle and extrapolate to the human clinical scenario, making it advantageous. In addition, the size of this species allows for better selection of lymphatic vessels for vascularized lymph node resection. In this study, we present a procedure of vascular lymph node resection in the rabbit hindlimb for inducing secondary lymphedema. Anesthetized animals were subjected to circumferential measurement, patent blue V infiltration, and indocyanine green lymphography (ICG-L) using real-time near-infrared fluorescence, a technique that allows the identification of single popliteal nodes and lymphatic channels. Access to the identified structures is achieved by excising the popliteal node and ligating the medial and lateral afferent lymphatics. Special care must be taken to ensure that any lymphatic vessel that joins the femoral lymphatic system within the thigh without entering the popliteal node can be identified and ligated. Postoperative evaluation was performed at 3, 6, and 12 months after induction using circumferential measurements of the hindlimb and ICG-L. As demonstrated during follow-up, the animals developed dermal backflow that was maintained until the 12th month, making this experimental animal useful for novel long-term evaluations in the management of lymphedema. In conclusion, the approach described here is feasible and reproducible. Additionally, during the time window presented, it can be representative of human lymphedema, thus providing a useful research tool.

New Polymeric Composites Based on Two-Dimensional Nanomaterials for Biomedical Applications.

The constant evolution and advancement of the biomedical field requires robust and innovative research. Two-dimensional nanomaterials are an emerging class of materials that have risen the attention of the scientific community. Their unique properties, such as high surface-to-volume ratio, easy functionalization, photothermal conversion, among others, make them highly versatile for a plethora of applications ranging from energy storage, optoelectronics, to biomedical applications. Recent works have proven the efficiency of 2D nanomaterials for cancer photothermal therapy (PTT), drug delivery, tissue engineering, and biosensing. Combining these materials with hydrogels and scaffolds can enhance their biocompatibility and improve treatment for a variety of diseases/injuries. However, given that the use of two-dimensional nanomaterials-based polymeric composites for biomedical applications is a very recent subject, there is a lot of scattered information. Hence, this review gathers the most recent works employing these polymeric composites for biomedical applications, providing the reader with a general overview of their potential.

Serological survey for IgG antibodies against SARS-CoV-2 from newborns and their mothers / Inquérito sorológico para anticorpos IgG contra SARS-CoV-2 de recém-nascidos e suas mães / Encuesta serológica de anticuerpos IgG contra el SARS-CoV-2 de recién nacidos y sus madres

This serological survey, conducted in five Brazilian municipalities, evaluated the use of dried blood spots (DBS), obtained from newborns and their mothers, to detect SARS-CoV-2 IgG antibodies. DBS were obtained from 4,803 neonates aged up to seven days and their mothers, both asymptomatic, at public health care clinics during newborn screening. DBS were processed by ELISA to detect IgG antibodies against SARS-CoV-2 nucleocapsid antigen. Mothers of seropositive neonates were interviewed about sociodemographic characteristics and clinical and laboratory antecedents. Non-satisfactory samples, dyads with incomplete data, and vaccinated mothers were excluded. Of the 1,917 DBS dyads samples analyzed, 14.7% of neonates showed IgG antibodies against SARS-CoV-2. Among seropositive neonates, 73.2% of their mothers were also seropositive. More than half of the mothers with seropositive neonates denied clinical or laboratory suspicion of COVID-19 during pregnancy. Suspicion occurred in the third trimester for 24.6% of the mothers. This study tested an innovative strategy to improve the understanding of COVID-19 antibody dynamics during pregnancy and suggests the feasibility of a universal serological survey in puerperal women and neonates.

Este inquérito sorológico, realizado em cinco municípios brasileiros, avaliou o uso de sangue seco em papel filtro (DBS), obtidas de recém-nascidos e suas mães, para detectar anticorpos IgG SARS-CoV-2. DBS foram obtidas de 4.803 neonatos com até sete dias de vida e suas mães, ambos assintomáticos, em unidades de saúde pública durante a triagem neonatal. DBS foram processadas ​​por ELISA para detectar anticorpos IgG contra o antígeno do nucleocapsídeo SARS-CoV-2. As mães de neonatos soropositivos foram entrevistadas quanto às características sociodemográficas e antecedentes clínicos e laboratoriais. Foram excluídas amostras insatisfatórias, díades com dados incompletos e mães vacinadas. Das 1.917 amostras analisadas, 14,7% dos neonatos apresentaram anticorpos IgG contra SARS-CoV-2. Entre os recém-nascidos soropositivos, 73,2% era filho de mulheres também soropositivas. Mais da metade das mães com recém-nascidos soropositivos negaram suspeita clínica ou laboratorial de COVID-19 durante a gravidez. A suspeita de COVID-19 ocorreu no terceiro trimestre para 24,6% das mães. Este estudo testou uma estratégia inovadora para melhorar a compreensão da dinâmica de anticorpos contra SARS-CoV-2 durante a gravidez e sugere a viabilidade de realização de um inquérito sorológico universal em puérperas e neonatos.

Esta encuesta serológica, realizada en cinco municipios brasileños, evaluó el uso de manchas de sangre seca (DBS), obtenidas de recién nacidos y sus madres, para detectar anticuerpos IgG contra el SARS-CoV-2. Se obtuvieron DBS de 4.803 recién nacidos de hasta siete días de edad y sus madres, ambos asintomáticos, en clínicas de salud pública durante el cribado neonatal. Las DBS se procesaron mediante ELISA para detectar anticuerpos IgG contra el antígeno de la nucleocápside del SARS-CoV-2. Se entrevistó a madres de recién nacidos seropositivos sobre características sociodemográficas y antecedentes clínicos y de laboratorio. Se excluyeron muestras no satisfactorias, díadas con datos incompletos y madres vacunadas. De las 1.917 muestras de díadas DBS analizadas, el 14,7 % de los recién nacidos mostró anticuerpos IgG contra el SARS-CoV-2. Entre los recién nacidos seropositivos, el 73,2% de sus madres también eran seropositivas. Más de la mitad de las madres con recién nacidos seropositivos negaron sospecha clínica o de laboratorio de COVID-19 durante el embarazo. La sospecha ocurrió en el tercer trimestre para el 24,6% de las madres. Este estudio probó una estrategia innovadora para mejorar la comprensión de la dinámica de anticuerpos de COVID-19 durante el embarazo y sugiere la viabilidad de una encuesta serológica universal en mujeres puérperas y recién nacidos.

Efeito da criolipólise na região abdominal / Effects of cryolipolysis in the abdominal region

O tecido adiposo forma uma camada abaixo da pele, na hipoderme, no qual se encontra o predomínio de adipócitos, um tipo de célula que acumula gotículas de lipídios em seu citoplasma. A técnica de criolipólise foi desenvolvida por pesquisadores da Universidade de Harvard, nos Estados Unidos, é um método não invasivo, que utiliza baixas temperaturas para eliminar a gordura localizada, assim não necessitando de anestesia ou qualquer substância injetável, indicado para pessoas que tenham gordura localizada, não sobrepeso. O objetivo desse trabalho foi verificar os resultados da criolipólise na região abdominal. Para realização do procedimento foram selecionadas três voluntarias do sexo feminino, com idades entre 26 e 34 anos, sendo as três com adiposidade localizada na região abdominal inferior e superior. Foi aplicado o procedimento de criolipólise no abdome, com duração de 60 minutos. Através da aplicação do procedimento podem-se observar resultados satisfatórios com a redução de medida. Assim conclui-se que o método de criolipólise foi eficaz na adiposidade localizada na região abdominal. (AU)

The adipose tissue forms a layer beneath the skin in the hypodermis, in which is the predominance of adipocytes, a type of cell that accumulates lipid droplets in its cytoplasm. The technique of cryolipolysis, developed at Harvard University in the United States, is a noninvasive method that uses low temperatures to eliminate localized fat, thus not requiring anesthesia or any injectable substance, indicated for people with localized fat, not for overweight. The aim of this study was to verify the results of cryolipolysis in the abdominal region. Three volunteers were selected to perform the procedure, with ages ranging from 26 to 34 years old, and three with adiposity located in the lower and upper abdominal regions. The cryolipolysis procedure was applied to the abdomen, with duration of 60 minutes. Through the application of the procedure satisfactory results could be observed with the measurement reduction. Thus, it was concluded that the cryolipolysis method was effective in localized adiposity in the abdominal region. (AU)