ABSTRACT Purpose: Enterocutaneous fistula (ECF) is a condition in which there is an abnormal connection between the intestinal tract and the skin. It can lead to high morbidity and mortality rates despite the availability of therapeutic options. Stem cells have emerged as a potential strategy to treat ECF. This study aimed to evaluate the effect of adipose tissue-derived stem cells (ASC) on ECF in an experimental model. Methods: ECF was induced in 21 Wistar rats, and after one month, they were divided into three groups: control group (C), culture medium without ASC group (CM), and allogeneic ASC group (ASC). After 30 days, the animals underwent macroscopic analysis of ECF diameter and histopathological analysis of inflammatory cells, tissue fibrosis, and vascular density. Results: The study found a 55% decrease in the ECF diameter in the ASC group (4.5 ± 1.4 mm) compared to the control group (10.0 ± 2.1 mm, p = 0.001) and a 59.1% decrease in the CM group (11.0 ± 4.3 mm, p = 0.003). The fibrosis score in the ASC group was 20.9% lower than the control group (p = 0.03). There were no significant differences in inflammation scores among the three groups. Conclusions: This study suggests that ASC treatment can reduce ECF diameter, and reduction in tissue fibrosis may be a related mechanism. Further studies are needed to understand the underlying mechanisms fully.

ABSTRACT Purpose: Palpebral congenital melanocytic nevi (PCMN) is a rare congenital skin lesion affecting the eyelids that can lead to cosmetic and psychological concerns and potential health risks such as malignancy. Several authors have analyzed therapeutical strategies to treat PCMN. However, there was no consensus in the literature. This systematic review aimed to evaluate the effectiveness, safety, and success of treatments of PCMN. Methods: We conducted a systematic review following PRISMA guidelines from October 2022 to April 2023. We included all types of study designs that described or compared PCMN treatments and interventions, as well as histology, recurrence, adverse events, patient satisfaction, and malignant transformation. The search strategy was based on specific search words through the following databases: PubMed, Embase, Latin American and Caribbean Health Sciences Literature (Lilacs), Web of Science, and Scopus. Ongoing studies and gray literature studies were included. Results: We analyzed 25 case reports with 148 participants. The effectiveness, success, and satisfaction with various treatments for PCMN depend on the specific treatment method and the individual patient’s case. Conclusions: Most of the studies showed that surgical procedures (exeresis) are able to treat PCMN in the eyelid. The variability in outcomes emphasizes the importance of further research to better understand the most effective and safe approaches for treating congenital melanocytic nevi.

ABSTRACT Purpose: To compare the effect of vein conduit filled with adipose tissue stem cells (ASC) on peripheral nerve injury regeneration. Methods: We analyzed 30 male Wistar rats surgically submitted to a 5-mm gap on the sciatic nerve. Then, the animals were divided into three groups: nerve autografting (AG, n=10), autogenous inverted glycerol-conserved vein (VG, n=10), and autogenous inverted glycerol-conserved vein + ASC (VASCG, n=10). The study endpoints were neuromotor functional analysis, gastrocnemius muscle weight, and sciatic nerve graft histomorphometry analysis. In the histologic analysis, we added a control group (naïve nerve). Results: Regarding functional analysis (Walking tract- score), the findings at week 3 showed a difference between the AG and the VG (-96.6 vs. -59.6, p=0.01, respectively) and between the VG and the inverted vein + VASCG (-59.9 vs. -88.92, p=0.02). At week 12, this study showed a difference between the AG and the VG (-64.8 vs. -47.3, p=0.004, respectively), and also a difference between the VG and the VASCG (-47.3 vs. -57.4, p=0.02, respectively). There was no difference in the histomorphometry analysis (nerve diameter, Schwann cells counting). The gastrocnemius muscles on the intervention side were more atrophic when compared to the gastrocnemius muscles on the control side. Conclusions: Our results suggested better functional recovery in the inverted vein group when compared to control group, and inverted vein + ASC group.

RESUMO Introdução: o nariz é o ponto central da face e vulnerável à ocorrência de câncer de pele não-melanoma (CPNM), com impacto potencial na aparência. O retalho frontal paramediano (RFPM) é considerado a melhor opção para o tratamento de defeitos extensos no nariz. O objetivo deste estudo é apresentar a experiência de um centro oncológico de referência no uso de RFPM para reconstrução nasal no tratamento do CPNM. Métodos: estudo retrospectivo foi desenvolvido através do levantamento de dados de prontuário de pacientes submetidos à reconstrução nasal com RFPM devido à CPNM no Instituto do Câncer do Estado de São Paulo (ICESP). Resultados: 111 pacientes foram identificados, a maioria idosos, com comorbidades e portadores de tumores iniciais (T1 e T2). O carcinoma basocelular (CBC) foi o tipo histológico predominante. Dorso e ponta foram as subunidades mais acometidas. Além da cobertura cutânea, em metade dos casos foi realizada também a reconstrução do forro ou arcabouço do nariz. Cicatrização por segunda intenção foi a técnica de escolha no fechamento da área doadora. A liberação do pedículo foi realizada predominantemente no segundo tempo cirúrgico e o tempo para finalização do tratamento teve mediana de 6 meses. Houve baixa taxa de complicações. Conclusões: o RFPM é seguro e eficaz no tratamento do CPNM nasal, mesmo em casos de elevada complexidade. O tempo total de tratamento pode ser prolongado e impactar na qualidade de vida, sendo fundamental enfatizar e discutir este aspecto com o paciente antes da cirurgia.

ABSTRACT Introduction: nose is the central point of the face and vulnerable to the occurence of non-melanoma skin cancer (NMSC), impacting on appearance. The paramedian forehead flap (PMFF) is considered the best option to treat extensive nasal defects. The objective of this study is to present the experience on PMFF for nasal reconstruction in the treatment of NMSC of a cancer referral center. Methods: retrospective study was carried out through data from medical records of patients who underwent nasal reconstruction with PMFF due to NMSC at the Cancer Institute of the State of São Paulo (ICESP). Results: 111 patients were identified, mostly ederly, with comorbidities and on initial tumors (T1 and T2). Basal cell carcinoma (BCC) was the predominant histological type. Dorsum and tip were the most affected subunitis. In addition to skin coverage, reconstruction of the lining and structural framework was also performed in half of the cases. Second intention healing was the technique of choice in closing the donor area. Pedicle division ocurred predominantly in the second operation and the median time to complete reconstruction was 6 months. There were low complication rates. Conclusions: the PMFF is safe and effective to treat nose NMSC, even in cases of high complexity. Since the treatment time can be prolonged and impact on quality of life, it is essential to emphasize and discuss this aspect with the patients before surgery.

ABSTRACT Purpose: To analyze the cytotoxicity and cell in porcine-derived decellularized skin matrix. Methods: We analyzed the effect of multiple decellularization processes by histological analysis, DNA quantification, and flow cytometry. Subsequently, we analyzed the most appropriate hydrogel concentration to minimize cytotoxicity on fibroblast culture and to maximize cell proliferation. Results: After the fourth decellularization, the DNA quantification showed the lowest DNA concentration (< 50 ng/mg). Histological analysis showed no cell components in the hydrogel. Moreover, hematoxylin and eosin showed a heterogeneous structure of collagen fibers. The best hydrogel concentration ranged from 3 to 25%, and there was no significant difference between the 24 hours and seven days. Conclusions: The process of hydrogel production was effective for removing cells and DNA elements. The best hydrogel concentration ranged from 3 to 25%.

RESUMO Introdução: 40% dos pacientes submetidos à radioterapia após reconstrução de mama por implante de prótese de silicone podem desenvolver encapsulamento da prótese. Diversas estratégias já foram testadas para prevenir a contratura da cápsula com resultados insatisfatórios. Este estudo analisou o efeito do antileucotrieno (AL) tópico na formação de contratura capsular em ratos com implantes de silicone associados à irradiação. Métodos: Foram implantados blocos de silicone na região dorsal em 20 ratas fêmeas, espécie Wistar com peso variando de 200-250g. Os animais foram divididos em dois grupos: controle (injeção de solução fisiológica 0,9% no tecido ao redor do implante) e grupo intervenção (injeção de 10mg de AL no tecido ao redor do implante). Imediatamente após a cirurgia os animais foram irradiados com dose única de 10Gy. Após dois meses, coletamos amostras de cápsulas para análise histológica e análise da expressão gênica dos seguintes biomarcadores: iNOS, VEGF-a e MMP-9. Resultados: A densidade vascular foi menor no grupo AL quando comparado ao grupo controle (55,4±30,0 vs. 81,8±26,7, p=0,05, respectivamente). Da mesma forma, o VEGF-a teve o mesmo comportamento (grupo controle - 0,34±0,1 vs. grupo Al - 0,02±0,001, p=0,04). Conclusão: Este estudo sugeriu que o tratamento com AL diminui a angiogênese em animais submetidos a implantes de silicone e submetidos à radioterapia

ABSTRACT Introduction: 40% of patients undergoing radiotherapy after breast reconstruction by silicone prosthesis implant may develop prosthesis encapsulation. Several strategies have already been tested to prevent capsule contracture with unsatisfactory results. This study analyzed the effect of topical antileukotriene (AL) on capsular contracture formation in rats with silicone implants associated with irradiation. Methods: Silicone blocks were implanted in the dorsal region in 20 female rats Wistar with weights ranging from 200-250g. The animals were divided into two groups: control (injection of 0.9% saline solution into the tissue around the implant) and intervention group (injection of 10mg of AL into the tissue around the implant). Immediately after surgery, the animals were irradiated with a single dose of 10Gy. After two months, we collected capsule samples for histological analysis and gene expression analysis of the following biomarkers: iNOS, VEGF-a and MMP-9. Results: Vascular density was lower in the AL group when compared to the control group (55.4±30.0 vs. 81.8±26.7, p=0.05, respectively). Similarly, VEGF-a had the same behavior (control group - 0.34±0.1 vs. group Al - 0.02±0.001, p=0.04). Conclusion: This study suggested that treatment with AL decreases angiogenesis in animals submitted to silicone implants and underwent radiotherapy.

ABSTRACT Purpose: To assess the effects of adipocyte-derived stem cell (ASC)-injection on the survival of surgical flaps under ischemia in diabetic rats. Methods: Diabetes was induced in 30 male Wistar rats using streptozotocin (55 mg/kg). After eight weeks, epigastric flap (EF) surgery was performed. The animals were divided into control (CG), medium-solution (MG), and ASC groups. The outcomes were: the survival area (SA), the survival/total area rate (S/TR), and expression levels (EL) of genes: C5ar1, Icam1, Nos2, Vegf-a. Results: In the ASC group, compared to CG, we observed improved flap SA (CG-420 mm2 vs. ASC-720 mm2; p=0.003) was observed. The S/TR analysis was larger in the ASC group (78%) than the CG (45%). This study showed an increase in the Vegf-a EL in the ASC group (2.3) vs. CG (0.93, p=0.0008). The Nos2 EL increased four-fold in the ASC group compared to CG, and C5ar1 EL decreased almost two-fold in the ASC group vs. the CG (p=0.02). There was no difference among the groups regarding Icam1 EL. Compared to the MG, the ASC group had a bigger flap SA (720 mm2 vs. 301 mm2, respectively), a bigger S/TR (78% vs. 32%, p=0.06, respectively) and increased EL of Vegf-a (2.3 vs. 1.3, respectively). No difference between ASC-group and MG was seen regarding Nos2 (p=0.08) and C5ar1 (p=0.05). Conclusions: This study suggests that ASCs increase the survival of EF under IR in diabetic rats.

ABSTRACT Purpose To evaluate the effect of light-emitting diode (LED) in an experimental model of radiodermatitis. Methods Ten male Wistar rats weighing 200–250 g were analyzed. Radiation was delivered in a single dose (20 Gy with Strontium-90 dermatological plaques), two areas per animal. After 15 days, they were divided into two groups: control group (n = 5) and LED group (n = 5), which was treated during 21 days later (LED 660 nm, 10 min in alternate days). The endpoints were radiodermatitis scale, histological analysis HE, Picrius Sirius and the gene expression of interleukin-10 (IL-10) and matrix metalloproteinase-9 (MMP-9). Results The LED group showed a higher number of dermal appendages (p = 0.04) and angiogenesis(p = 0.007), a tendency towards higher IL-10 (p = 0.06) and an increase in MMP-9 (p = 0.004) when compared to the control group. Conclusions This study suggested that the use of LED for radiodermatitis increased skin regeneration.

The COVID-19 pandemic demanded a quick shift from presential to e-learning processes. Unlike planned e-learning programs, medical schools have had to quickly deliver the entire medical curriculum using remote strategies. This study aimed to perform a meta-synthesis of previous pandemic situations and describe the experience of the São Paulo University School of Medicine. We searched the Cochrane Central Register of Controlled Trials, Medline, EMBASE, Lilacs, Scopus, Web of Science, and ERIC, using the following keywords: (“SARS” OR “severe acute respiratory syndrome” OR “severe acute respiratory syndrome” OR “Middle East Respiratory Syndrome Coronavirus” OR “middle east respiratory syndrome*” OR “MERS-CoV” OR “Mers” OR “Middle Eastern Respiratory Syndrome*” OR “MERS-CoV*” OR “coronavirus” OR “Coronavirus Infections” OR “coronavirus*” OR “COVID-19” OR “2019-nCoV” OR “SARS-CoV-2”) AND (“online education” OR “Education, Distance” OR “e-learning” OR “course online” OR “flipped classroom”) AND (“lockdown” OR “social distance” OR “quarantine”). The endpoints were the online platforms used for online learning, the model of class, recorded versus online interaction, duration of online lectures, and students' and teachers' perceptions of online learning. We retrieved 38 records; only seven articles studied online education methods related to the pandemic and social distancing rules. The most frequently used online platform was Zoom®. The studies examined both synchronous and asynchronous approaches. There was no evidence regarding duration and students’ and teachers' attitude. This study suggests that the online learning shift was feasible; however, because of the nature of the education shift (pandemic), future studies must further analyze the educational structure.

Abstract Purpose Given the high prevalence of diabetes (D), several animal models have been analyzed. In the literature, most of the animal models have studied severe D. However, in clinical practice, most patients have moderate disease. Therefore, the present study aimed to describe a moderate D condition. Methods We analyzed 20 Wistar rats, age eight-weeks, weight between 200g-250g. All animals received an intravenous injection of Streptozotocin (55mg/kg weight). On the 15th day after D induction, the animals were divided into two groups: Group I – animals receiving a single daily dose of fast-acting insulin (FAIG) NPH (1UI,SC) for partial glycemic control, and Group II - animals receiving slow-acting insulin(SAIG) twice a week. We measured glycemia, weight, and adverse events every week during two months. Results Of the total of animals analyzed in the study, three animals died in the FAIG and two animals died in the SAIG. Regarding the glycemic level, results were 339.5 ± 125.4mg/dL (95CI 302.3402 to 376.6842) in the FAIG, and 367.8 ± 66.1mg/dL (95IC 333.7607 to 401.8978) in the SAIG. There was no difference between groups as to weight during the study. Conclusion The use of slow-acting-insulin is not inferior to the use of fast-acting-insulin in the management of partially insulin-controlled moderate diabetes in rats.

Abstract Purpose: To evaluate the hyaluronic acid (HA) inflammatory reaction, fibroblasts, fibrosis and duration of effect in the dorsal region of tobacco-exposed rats. Methods: Ten Wistar rats were divided into two groups: tobacco-exposed-group (TEG;n=5) and air-control-group (CG;n=5). The TEG animals were tobacco-exposed twice a day, 30-minutes/session, during 60 days. After this period, all animals received 0.1 mL HA subcutaneous injection in the dorsal area. The volume of HA was measured immediately after HA injection and weekly using a hand-caliper in nine weeks. After this period, all the animals were euthanized, and a specimen of was collected to evaluate inflammatory cells, fibroblasts, and fibrosis by HE. Results: This study showed a higher inflammatory reaction in TEG than CG: inflammatory cell-count (CG: 1.07±0.9; TEG: 8.61±0.36, p<0.001); fibroblast count (CG: 2.92±0.17; TEG: 19.14±0.62, p<0.001), and fibrosis quantification (CG: 2.0; TEG: 3.75, p<0.001). The analysis of the HA volume in nine weeks in the dorsal region did not show a difference between groups (p=0.39). Conclusions: This study suggested that the HA injection in the TEG caused an increase in inflammatory cell count, fibroblast, and fibrosis quantification when compared to the CG. There was no difference in the duration of effect of HA between the groups.

Abstract Purpose: To evaluate the serum variations of Interleukins (Il) and CPR of abdominoplasties in post-bariatric patients and, to equate the homeostasis (HOMA) from the variations of glycemia and insulin to evolute the metabolic modifications. Methods: Fourteen women were submitted to abdominoplasties with weight loss after a gastroplasty. Levels of IL4, IL6, IL10, CRP, glycemia and insulin were obtained during the pre-operative, trans-operative, 24 hours post, 7th and 14th postoperative days. Results: The IL4 was higher at 24 hours post-surgery, and after a moderate decrease, it remained high until the 14th day. The IL6 and CRP had an expressive increase during the trans-operative period. The CRP remained high, and the IL6 decreased on the 7th and 14th days. The IL10 increased during the transoperative period, and it posteriorly decreased to lower levels in comparison to the pre-operative period. The already increased glycemia during the pre-operative period was even higher during the trans-operative and then, returned to preliminary values on the 7th and 14th days after surgery. The HOMA accompanied the insulin. Conclusion: The inflammatory and glycemic serum levels decrease after abdominiplasty in obese post-bariatric patients.

RESUMO Objetivo: descrever a presença de linfonodos e suas relações com características demográficas e antropométricas em uma região específica ainda não descrita pelos compêndios de anatomia, por nós denominada de Recesso Carotídeo Recorrencial (RCR), localizada entre o nervo laríngeo recorrente direito, a artéria carótida comum direita e a artéria tireoidea inferior direita. Métodos: foram dissecadas 32 regiões cervicais à direita de cadáveres com até 24 horas de post mortem. O tecido fibrogorduroso do RCR foi ressecado e preparado com fixação em formol. Em seguida, foi submetido a uma sequência crescente de álcoois (70%, 80% e 90%), posteriormente a uma solução de Xilol e, por fim, a uma solução de Salicilato de Metila, respeitando o tempo necessário de cada etapa. O estudo macroscópico foi realizado na peça diafanizada, observando a presença ou não de linfonodos. Quando presentes, foram fotografados e suas medidas foram aferidas com um paquímetro digital. No estudo microscópico, foi utilizada a coloração hematoxilina-eosina para confirmação do linfonodo. Resultados: observou-se a presença de linfonodos em 22 dos 32 espécimes (68,75%), com o número de linfonodos por cadáver variando de zero a seis (média de 1,56±0,29) e tamanho com média de 7,82mmx3,86mm (diâmetros longitudinal x transversal). Conclusão: a relação entre dados antropométricos e presença de linfonodos no RCR (teste exato de Fischer) foi significante para indivíduos normolíneos (p=0,03) e também significante entre a etnia branca (p=0,04).

ABSTRACT Objective: to describe the presence of lymph nodes and their relationships with demographic and anthropometric characteristics in a specific region, not yet described in anatomy compendiums, called by us Recurrent Carotid Recess (RCR) and located among the right recurrent laryngeal nerve, the right common carotid artery, and the right inferior thyroid artery. Methods: 32 right cervical regions were harvested from cadavers within 24 hours post-mortem. The fibro-fatty tissue of the RCR was resected and prepared with formalin fixation. It was then subjected to an increasing sequence of alcohols (70%, 80%, and 90%), subsequently to a solution of Xylol, and finally to a solution of Methyl Salicylate, respecting the time required for each step. The macroscopic study was carried out on the diaphanized piece, observing the presence or not of lymph nodes. When present, they were photographed and their measurements were gauged with a digital caliper. In the microscopic study, hematoxylin-eosin staining was used to confirm the lymph node. Results: the presence of lymph nodes was observed in 22 (68.75%) of the 32 specimens. The number of lymph nodes ranged from zero to six (mean of 1.56±0.29), per cadaver, and their mean size was 7.82mmx3.86mm (longitudinal x transversal diameters). Conclusion: the relationship between anthropometric data and presence of lymph nodes in the RCR (Fisher’s exact test) was significant for medium-height individuals (p=0.03) and also white ones (p=0.04).

Abstract Purpose: To introduce a nonliving microvascular training model based on vessels diameter and feasibility. Methods: We dissected ten oxen tongues, and divided the pedicles into three-thirds: proximal, middle and distal. We measured the external vessels diameter in all regions. We performed a descriptive statistical analysis. Three students (two beginner level and one intermediate level) performed this training. We evaluated the confidence, according Likert scale. Results: We dissected all oxen tongues, each tongue showed two parallel pedicles. Each pedicle was located at 1.5 - 2.0 cm from the midline. Proximal median artery and vein diameter were 3.9 ± 0.7, and 5.04 ± 1.44mm, respectively. In the middle third, the mean artery diameter was 3.3 ± 0.4mm, and the vein diameter was 3.5 ± 0.9mm. The distal third showed a mean artery diameter of 2.0 ± 0.42mm, and a vein diameter of 2.4 ± 0.82mm. The students performed ten anastomoses. This study showed a higher confidence level (CL) (p=0.03) than the pre training CL assessment. Conclusion: This study suggested a feasible non-animal model for microsurgical training process for beginners and intermediate trainees.

ABSTRACT PURPOSE: To evaluate the effect of Botulinum Toxin A in different time of tobacco exposure. METHODS: 60 male, Wistar rats were divided into two tobacco exposure groups: a 2- month or a 4-month regimen. After this period, these two groups were subdivided as two: saline solution(SS) or botulinum toxin A(Bonta), at the time of the surgery. Seven days before the SS or Bonta injection, the animals were submitted to a random flap (3x10cm). On the seventh postoperative day, all animals were assessed for total flap area, viable area, and the viable/ total area ratio. RESULTS: This study showed a difference between groups 2-month saline vs. BontA injection (p=0.04); groups 4-month saline vs. BontA injection (p=0.001); groups 2-month saline vs. 4-month BontA (p=0.003), and, between groups 2- month BontA vs. 4-month saline(p=0.03). CONCLUSIONS: Botulinum Toxin A increased random flap viability in tobacco-exposed rats. Two months of tobacco exposure had the same effect as exposure for four months.