Synuclein Family Members Prevent Membrane Damage by Counteracting α-Synuclein Aggregation.

The 140 amino acid protein α-synuclein (αS) is an intrinsically disordered protein (IDP) with various roles and locations in healthy neurons that plays a key role in Parkinson's disease (PD). Contact with biomembranes can lead to α-helical conformations, but can also act as s seeding event for aggregation and a predominant ß-sheet conformation. In PD patients, αS is found to aggregate in various fibrillary structures, and the shift in aggregation and localization is associated with disease progression. Besides full-length αS, several related polypeptides are present in neurons. The role of many αS-related proteins in the aggregation of αS itself is not fully understood Two of these potential aggregation modifiers are the αS splicing variant αS Δexon3 (Δ3) and the paralog ß-synuclein (ßS). Here, polarized ATR-FTIR spectroscopy was used to study the membrane interaction of these proteins individually and in various combinations. The method allowed a continuous monitoring of both the lipid structure of biomimetic membranes and the aggregation state of αS and related proteins. The use of polarized light also revealed the orientation of secondary structure elements. While αS led to a destruction of the lipid membrane upon membrane-catalyzed aggregation, ßS and Δ3 aggregated significantly less, and they did not harm the membrane. Moreover, the latter proteins reduced the membrane damage triggered by αS. There were no major differences in the membrane interaction for the different synuclein variants. In combination, these observations suggest that the formation of particular protein aggregates is the major driving force for αS-driven membrane damage. The misbalance of αS, ßS, and Δ3 might therefore play a crucial role in neurodegenerative disease.

Weight loss and adherence to postoperative follow-up after vertical gastrectomy for obesity treatment.

PURPOSE: To analyze the effectiveness of vertical gastrectomy in the treatment of obese patients, adherence to clinical follow-up and the influence of factors such as gender and age. METHODS: This is a retrospective, observational and descriptive study, conducted with patients undergoing vertical gastrectomy, operated at Hospital São Domingos, between January 2016 and July 2018. RESULTS: Most patients undergoing vertical gastrectomy were female (n = 193, 72.28%) and had a mean age of37.11 ± 8.96 years old. The loss of follow-up was 56.18%. Among adherent patients (n = 117; 43.82%), most patients were female (n = 89; 76.07%) and had a mean age of 37.92 ± 9.85 years old. The mean body mass index (BMI) of the adherents in the preoperative was 37.85 ± 3.72 kg/m2. Both BMI and excess weight (EW) showed a statistically significant difference between pre- and postoperative period. Percentage of excess weight loss (% EWL) was satisfactory for 96.6% of adherent patients. Older patients had a statistically significant lower % EWL compared to the other groups. CONCLUSIONS: Vertical gastrectomy was effective in the treatment of obese patients, with significant weight loss.

Weight loss and adherence to postoperative follow-up after vertical gastrectomy for obesity treatment

ABSTRACT Purpose To analyze the effectiveness of vertical gastrectomy in the treatment of obese patients, adherence to clinical follow-up and the influence of factors such as gender and age. Methods This is a retrospective, observational and descriptive study, conducted with patients undergoing vertical gastrectomy, operated at Hospital São Domingos, between January 2016 and July 2018. Results Most patients undergoing vertical gastrectomy were female (n = 193, 72.28%) and had a mean age of37.11 ± 8.96 years old. The loss of follow-up was 56.18%. Among adherent patients (n = 117; 43.82%), most patients were female (n = 89; 76.07%) and had a mean age of 37.92 ± 9.85 years old. The mean body mass index (BMI) of the adherents in the preoperative was 37.85 ± 3.72 kg/m2. Both BMI and excess weight (EW) showed a statistically significant difference between pre- and postoperative period. Percentage of excess weight loss (% EWL) was satisfactory for 96.6% of adherent patients. Older patients had a statistically significant lower % EWL compared to the other groups. Conclusions Vertical gastrectomy was effective in the treatment of obese patients, with significant weight loss.

A Prospective Single-Arm Trial of Modified Long Biliopancreatic and Short Alimentary Limbs Roux-En-Y Gastric Bypass in Type 2 Diabetes Patients with Mild Obesity.

BACKGROUND: Type-2 diabetes (T2D) patients with body mass index (BMI) below 35 kg/m2 carry lower remission rates than severely obese T2D individuals submitted to "standard limb lengths" Roux-en-Y gastric bypass (RYGB). Mild-obese patients appear to have more severe forms of T2D, where the mechanisms of glycemic control after a standard-RYGB may be insufficient. The elongation of the biliopancreatic limb may lead to greater stimulation of the distal intestine, alterations in bile acids and intestinal microbiota, among other mechanisms, leading to better metabolic outcomes. The aim of this study is to evaluate the safety and efficacy of the RYGB with a biliopancreatic limb of 200 cm in the control of T2D in patients with BMI 30-35 kg/m2. METHODS: From January 2011 to May 2015, 102 T2D patients with BMI from 30 to 34.9 kg/m2 underwent laparoscopic RYGB with the biliopancreatic-limb of 200 cm and the alimentary-limb of 50 cm. RESULTS: There were no deaths or reoperations. The mean follow-up was 28.1 months. The mean BMI dropped from 32.5 to 25.1 kg/m2, while the mean fasting glucose decreased from 182.9 to 89.8 mg/dl and the mean glycated hemoglobin (HbA1c) went from 8.7 to 5.2%. During follow-up, 92.2% had their T2D under complete control (HbA1c < 6%, no anti-diabetic medications), while 7.8% were under partial control. Control of hypertension and dyslipidemia were 89.4 and 85.5%, respectively. No patient developed hypoalbuminemia, and there were mild micronutrient deficiencies. CONCLUSIONS: RYGB with long-biliopancreatic and short-alimentary limbs is safe and seems effective in achieving complete control of T2D in patients with BMIs between 30 and 35 kg/m2.

Simultaneous IR-Spectroscopic Observation of α-Synuclein, Lipids, and Solvent Reveals an Alternative Membrane-Induced Oligomerization Pathway.

The intrinsically disordered protein α-synuclein (αS), a known pathogenic factor for Parkinson's disease, can adopt defined secondary structures when interacting with membranes or during fibrillation. The αS-lipid interaction and the implications of this process for aggregation and damage to membranes are still poorly understood. Therefore, we established a label-free infrared (IR) spectroscopic approach to allow simultaneous monitoring of αS conformation and membrane integrity. IR showed its unique sensitivity for identifying distinct ß-structured aggregates. A comparative study of wild-type αS and the naturally occurring splicing variant αS Δexon3 yielded new insights into the membrane's capability for altering aggregation pathways.

Schinus terebinthifolius raddi (Aroeira) and Orbignya phalerata mart. (Babassu) effect in cecorrahphy healing in rats.

PURPOSE: To evaluate the effect of Schinus terebinthifolius Raddi (aroeira) and Orbignya phalerata Mart. (babassu) in the healing process of cecorrhaphy in rats. METHODS: : Fifty four rats were used, distributed into three groups randomly: aroeira, babassu and control, which were divided into three subgroups (six animals) according to the time of the deaths (7, 14, 21 days). All underwent the same surgical procedure, cecotomy and cecorrhaphy. The animals in group aroeira and babassu received daily dose of 100 mg/kg of hydroalcoholic extract and 50 mg/kg of aquous extract respectively, by gavage. The control group received only saline solution. The parameters evaluated were: macroscopic changes, ,resistance test to air insufflations and histological changes. RESULTS: : All animals showed good healing without infection. All groups presented adhesions between cecum and neighboring organs. The resistance test insufflating of atmospheric air showed progressive increase of pressure according to the days in the aroeira group, and decrease in babassu group, without significant difference. Microscopy showed significant difference in the polymorphonuclear, hyperemia, angiogenesis, fibroblast proliferation and collagen histological variables in the 14th day. CONCLUSION: : Hydroalcoholic extract of aroeira and the aqueous extract of babassu favored the healing process in cecorrhaphy in rats.

Schinus terebinthifolius raddi (Aroeira) and Orbignya phalerata mart. (Babassu) effect in cecorrahphy healing in rats

ABSTRACT PURPOSE: To evaluate the effect of Schinus terebinthifolius Raddi (aroeira) and Orbignya phalerata Mart. (babassu) in the healing process of cecorrhaphy in rats. METHODS : Fifty four rats were used, distributed into three groups randomly: aroeira, babassu and control, which were divided into three subgroups (six animals) according to the time of the deaths (7, 14, 21 days). All underwent the same surgical procedure, cecotomy and cecorrhaphy. The animals in group aroeira and babassu received daily dose of 100 mg/kg of hydroalcoholic extract and 50 mg/kg of aquous extract respectively, by gavage. The control group received only saline solution. The parameters evaluated were: macroscopic changes, ,resistance test to air insufflations and histological changes. RESULTS : All animals showed good healing without infection. All groups presented adhesions between cecum and neighboring organs. The resistance test insufflating of atmospheric air showed progressive increase of pressure according to the days in the aroeira group, and decrease in babassu group, without significant difference. Microscopy showed significant difference in the polymorphonuclear, hyperemia, angiogenesis, fibroblast proliferation and collagen histological variables in the 14th day. CONCLUSION : Hydroalcoholic extract of aroeira and the aqueous extract of babassu favored the healing process in cecorrhaphy in rats.

FIXING JEJUNAL MANEUVER TO PREVENT PETERSEN HERNIA IN GASTRIC BYPASS.

BACKGROUND: Among Roux-en-Y gastric bypass complications is the occurrence of intestinal obstruction by the appearance of internal hernias, which may occur in Petersen space or the opening in mesenteric enteroenteroanastomosis. AIM: To evaluate the efficiency and safety in performing a fixing jejunal maneuver in the transverse mesocolon to prevent internal hernia formation in Petersen space. METHOD: Two surgical points between the jejunum and the transverse mesocolon, being 5 cm and 10 cm from duodenojejunal angle are made. In all patients was left Petersen space open and closing the opening of the mesenteric enteroenteroanastomosis. RESULTS: Among 52 operated patients, 35 were women (67.3%). The age ranged 18-63 years, mean 39.2 years. BMI ranged from 35 to 56 kg/m2 (mean 40.5 kg/m2). Mean follow-up was 15.1 months (12-18 months). The operative time ranged from 68-138 min. There were no intraoperative complications, and there were no major postoperative complications and no reoperations. The hospital stay ranged from 2-3 days. During the follow-up, no one patient developed suspect clinical presentation of internal hernia. Follow-up in nine patients (17.3%) showed asymptomatic cholelithiasis and underwent elective laparoscopic cholecystectomy. During these procedures were verified the Petersen space and jejunal fixation. In all nine, there was no herniation of the jejunum to the right side in Petersen space. CONCLUSION: The fixation of the first part of the jejunum to left side of the transverse mesocolon is safe and effective to prevent internal Petersen hernia in RYGB postoperatively in the short and medium term. It may be interesting alternative to closing the Petersen space.

Cleaning of biomaterial surfaces: protein removal by different solvents.

The removal of biofilms or protein films from biomaterials is still a challenging task. In particular, for research investigations on real (applied) surfaces the reuse of samples is of high importance, because reuse allows the comparison of the same sample in different experiments. The aim of the present study was to evaluate the cleaning efficiency of different solvents (SDS, water, acetone, isopropanol, RIPA-buffer and Tween-20) on five different biomaterials (titanium, gold, PMMA (no acetone used), ceramic, and PTFE) with different wettability which were covered by layers of two different adsorbed proteins (BSA and lysozyme). The presence of a protein film after adsorption was confirmed by transmission electron microscopy (TEM). After treatment of the surfaces with the different solvents, the residual proteins on the surface were determined by BCA-assay (bicinchoninic acid assay). Data of the present study indicate that SDS is an effective solvent, but for several protein-substrate combinations it does not show the cleaning efficiency often mentioned in literature. RIPA-buffer and Tween-20 were more effective. They showed very low residual protein amounts after cleaning on all examined material surfaces and for both proteins, however, with small differences for the respective substrate-protein combinations. RIPA-buffer in combination with ultrasonication completely removed the protein layer as confirmed by TEM.

Cleaning of titanium substrates after application in a bioreactor.

Plain and microstructured cp-titanium samples were studied as possible biofilm reactor substrates. The biofilms were grown by exposition of the titanium samples to bacteria in a flow cell. As bacteria the rod shaped gram negative Pseudomonas fluorescens and the spherical gram negative Paracoccus seriniphilus were chosen. Afterward, the samples were cleaned in subsequent steps: First, with a standard solvent based cleaning procedure with acetone, isopropanol, and ultrapure water and second by oxygen plasma sputtering. It will be demonstrated by means of x-ray photoelectron spectroscopy, fluorescence microscopy, and confocal laser scanning microscopy that oxygen plasma cleaning is a necessary and reliant tool to fully clean and restore titanium surfaces contaminated with a biofilm. The microstructured surfaces act beneficial to biofilm growth, while still being fully restorable after biofilm contamination. Scanning electron microscopy images additionally show, that the plasma process does not affect the microstructures. The presented data show the importance of the cleaning procedure. Just using solvents does not remove the biofilm and all its components reliably while a cleaning process by oxygen plasma regenerates the surfaces.

FIXING JEJUNAL MANEUVER TO PREVENT PETERSEN HERNIA IN GASTRIC BYPASS / MANOBRA DE FIXAÇÃO JEJUNAL PARA PREVENÇÃO DE HÉRNIA DE PETERSEN EM BYPASS GÁSTRICO

Background: Among Roux-en-Y gastric bypass complications is the occurrence of intestinal obstruction by the appearance of internal hernias, which may occur in Petersen space or the opening in mesenteric enteroenteroanastomosis.Aim: To evaluate the efficiency and safety in performing a fixing jejunal maneuver in the transverse mesocolon to prevent internal hernia formation in Petersen space.Method: Two surgical points between the jejunum and the transverse mesocolon, being 5 cm and 10 cm from duodenojejunal angle are made. In all patients was left Petersen space open and closing the opening of the mesenteric enteroenteroanastomosis.Results: Among 52 operated patients, 35 were women (67.3%). The age ranged 18-63 years, mean 39.2 years. BMI ranged from 35 to 56 kg/m2 (mean 40.5 kg/m2). Mean follow-up was 15.1 months (12-18 months). The operative time ranged from 68-138 min. There were no intraoperative complications, and there were no major postoperative complications and no reoperations. The hospital stay ranged from 2-3 days. During the follow-up, no one patient developed suspect clinical presentation of internal hernia. Follow-up in nine patients (17.3%) showed asymptomatic cholelithiasis and underwent elective laparoscopic cholecystectomy. During these procedures were verified the Petersen space and jejunal fixation. In all nine, there was no herniation of the jejunum to the right side in Petersen space.Conclusion: The fixation of the first part of the jejunum to left side of the transverse mesocolon is safe and effective to prevent internal Petersen hernia in RYGB postoperatively in the short and medium term. It may be interesting alternative to closing the Petersen space.

Racional: Entre outras complicações do bypass gástrico em Y-de-Roux está a ocorrência de obstrução intestinal pelo aparecimento de hérnias internas, que podem ocorrer no espaço de Petersen ou na abertura mesentérica da enteroenteroanastomose.Objetivo: Avaliar a eficiência e a segurança da realização de uma manobra de fixação do jejuno no mesocólon transverso para evitar formação de hérnia interna no espaço de Petersen.Método: Realizam-se dois pontos de fixação entre o jejuno e o mesocólon transverso, sendo um a 5 cm e outro a 10 cm do ângulo duodenojejunal. Em todos os pacientes foi deixado o espaço de Petersen aberto e realizado o fechamento da abertura mesentérica da enteroenteroanastomose.Resultados: Entre 52 pacientes estudados, 35 eram do sexo feminino (67,3%). A idade variou de 18 a 63 anos, com média de 39,2 anos. O IMC variou de 35 a 56 kg/m2 (média de 40,5 kg/m2). O seguimento médio foi de 15,1 meses (de 12 a 18 meses). O tempo operatório variou de 68-138 min. Não ocorreram intercorrências intra-operatórias, assim como não houve complicações pós-operatórias maiores e nem reoperações. O período de internação hospitalar variou de 2-3 dias. Durante o seguimento, nenhum paciente desenvolveu quadro suspeito de hérnia interna. Neste período, nove pacientes (17,3%) apresentaram quadro de colecistolitíase (por microcálculos) assintomática, e foram submetidos à colecistectomia videolaparoscópica eletiva. Durante estes procedimentos foram verificados o espaço de Petersen e a fixação jejunal. Em todos os nove, não havia herniação do jejuno para o lado direito do espaço de Petersen.Conclusão: A fixação da primeira parte do jejuno ao lado esquerdo do mesocólon transverso é segura e eficiente para evitar hérnia interna de Petersen em pós-operatório de BGYR no curto e médio prazo. Pode ser interessante alternativa ao fechamento do espaço de Petersen.

Carbohydrate-PNA and aptamer-PNA conjugates for the spatial screening of lectins and lectin assemblies.

Nucleic acid architectures offer intriguing opportunities for the interrogation of structural properties of protein receptors. In this study, we performed a DNA-programmed spatial screening to characterize two functionally distinct receptor systems: 1) structurally well-defined Ricinus communis agglutinin (RCA(120)), and 2) rather ill-defined assemblies of L-selectin on nanoparticles and leukocytes. A robust synthesis route that allowed the attachment both of carbohydrate ligands-such as N-acetyllactosamine (LacNAc), sialyl-Lewis-X (sLe(X)), and mannose-and of a DNA aptamer to PNAs was developed. A systematically assembled series of different PNA-DNA complexes served as multivalent scaffolds to control the spatial alignments of appended lectin ligands. The spatial screening of the binding sites of RCA(120) was in agreement with the crystal structure analysis. The study revealed that two appropriately presented LacNAc ligands suffice to provide unprecedented RCA(120) affinity (K(D) = 4 µM). In addition, a potential secondary binding site was identified. Less dramatic binding enhancements were obtained when the more flexible L-selectin assemblies were probed. This study involved the bivalent display both of the weak-affinity sLe(X) ligand and of a high-affinity DNA aptamer. Bivalent presentation led to rather modest (sixfold or less) enhancements of binding when the self-assemblies were targeted against L-selectin on gold nanoparticles. Spatial screening of L-selectin on the surfaces of leukocytes showed higher affinity enhancements (25-fold). This and the distance-activity relationships indicated that leukocytes permit dense clustering of L-selectin.