Efficiency and safety of single anastomosis sleeve ileal (SASI) bypass in the treatment of obesity and associated comorbidities: a systematic review and meta-analysis.

INTRODUCTION: The Single Anastomosis Sleeve Ileal (SASI) bypass is a new bariatric surgery corresponding to an adaptation of the Santoro approach, consisting of a sleeve gastrectomy (SG) followed by loop gastroileostomy. Therefore, we aimed to systematically assess all the current literature on SASI bypass in terms of safety, weight loss, improvement in associated comorbidities, and complications. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) recommendations, we conducted a systematic review and meta-analysis by searching three databases (PubMed, Scopus, and Web of Science). We performed a meta-analysis of risk ratios and mean differences to compare surgical approaches for excessive weight loss, improvement/remission in type 2 diabetes mellitus (T2DM), hypertension (HT), dyslipidemia (DL), obstructive sleep apnea (OSA), and complications. Heterogeneity was assessed using the I2 statistic. RESULTS: Eighteen studies were included in the qualitative analysis and four in the quantitative analysis, comparing SASI bypass with SG and One-Anastomosis Gastric Bypass (OAGB). A comparison between Roux-en-Y Gastric Bypass (RYGB) and SASI bypass could not be performed. Compared to SG, the SASI bypass was associated with improved weight loss (MD = 11.32; 95% confidence interval (95%CI) [7.89;14.76]; p < 0.0001), and improvement or remission in T2DM (RR = 1.35; 95%CI [1.07;1.69]; p = 0.011), DL (RR = 1.41; 95%CI [1.00;1.99]; p = 0.048) and OSA (RR = 1.50; 95%CI [1.01;2.22]; p = 0.042). No statistically significant differences in any of the assessed outcomes were observed when compared with OAGB. When compared to both SG and OAGB, the complication rate of SASI was similar. CONCLUSION: Although studies with longer follow-up periods are needed, this systematic review and meta-analysis showed that SASI bypass has a significant effect on weight loss and metabolic variables. Variations in outcomes between studies reinforce the need for standardization.

Assessing Nutritional Deficiencies in Bariatric Surgery Patients: A Comparative Study of Roux-en-Y Gastric Bypass versus Sleeve Gastrectomy.

Obesity is a worldwide epidemic, and bariatric surgery is considered the primary treatment for long-term weight loss and managing obesity-related health issues. Sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) are the most performed procedures. Nutritional deficiencies are a significant concern following bariatric surgery and can have serious consequences. This study aims to compare the incidence of nutritional deficiencies in patients undergoing RYGB and SG. A retrospective analysis was conducted on the nutritional status of 505 consecutive patients who underwent either RYGB or SG between January and December 2019. Data were collected regarding vitamin B12, folic acid, vitamin D, calcium, PTH, magnesium, hemoglobin, iron, ferritin, and transferrin at preoperative, 6-month, and 12-month intervals post-surgery. The RYGB group showed significantly higher excess weight loss. Vitamin B12, hemoglobin, and ferritin levels were consistently higher in the SG group throughout the study. Vitamin D deficiency was prevalent, with no significant difference between the groups. Vitamin B12 deficiency was significantly more common in the RYGB group (6 months: 17.46% vs. 4.69%, p < 0.001; 12 months: 16.74% vs. 0.93%, p < 0.001). Despite differences in their mechanisms, bariatric surgeries were associated with nutritional deficiencies. It is crucial to efficiently assess, prevent, and manage these deficiencies tailored to each surgical procedure.

The Impact of Cholecystectomy in Patients with Post-Bariatric Surgery Hypoglycemia.

BACKGROUND: Metabolic surgery is the foremost treatment for obesity and its associated medical conditions. Nonetheless, post-bariatric hypoglycemia (PBH) emerges as a prevalent complication. PBH pathophysiology implicates heightened insulin and glucagon-like peptide 1 (GLP-1) levels, with bile acids (BA) contributing to GLP-1 release. A plausible association exists between cholecystectomy and PBH, which is attributed to alterations in BA metabolism and ensuing hormonal responses. The objective of this retrospective cohort study was to evaluate the impact of cholecystectomy on PBH pharmacological treatment, diagnostic timelines and metabolic parameters. MATERIALS AND METHODS: Patients diagnosed with PBH after bariatric surgery were evaluated based on their history of cholecystectomy. Demographic, anthropometric and clinical data were collected. Mixed meal tolerance tests (MMTT) results were compiled to assess metabolic responses. RESULTS: Of the 131 patients with PBH included in the study, 29 had prior cholecystectomy. The time to PBH diagnosis was similar across groups. Patients with prior cholecystectomy required higher doses of acarbose (p = 0.046), compared to those without prior cholecystectomy. Additionally, MMTT revealed higher insulin (t = 60 min: p = 0.010 and t = 90 min: p = 0.034) and c-peptide levels (t = 60 min: p = 0.008) and greater glycemic variability in patients with prior cholecystectomy (p = 0.049), highlighting the impact of cholecystectomy on glucose metabolism. CONCLUSION: Our study offers novel insights into PBH pharmacotherapy, indicating that PBH patients with a history of cholecystectomy require elevated doses of acarbose for symptom control than PBH patients without such surgical history. Furthermore, our findings underscore the pivotal role of hyperinsulinism in PBH aetiology, emphasizing the significance of the BA-GLP-1-insulin axis.

Preoperative risk factors for early postoperative bleeding after Roux-en-Y gastric bypass surgery: a systematic review and meta-analysis.

PURPOSE: Although bariatric surgery is an effective intervention for obesity, it comes with risks such as early postoperative bleeding (EPB). Identifying preoperative risk factors for this complication can help patients' risk stratification and optimization. We performed a systematic review and meta-analysis to find predictors for early postoperative bleeding after Roux-en-Y gastric bypass (RYGB). METHODS: We conducted a systematic review, searching PubMed, Cochrane Library, and Web of Science until November 2023. We performed a random-effects meta-analysis to explore preoperative risk factors associated with early postoperative bleeding after RYGB. Sources of heterogeneity were explored by leave-one-out analyses. RESULTS: 23 studies were included, comprising 232,488 patients. Male gender (meta-analytical RR = 1.42, 95%CI = 1.21-1.66, I2 = 18%, Q Cochran test p-value = 0.29) and revisional surgery (meta-analytical RR = 1.35, 95%CI = 1.12-1.62, I2 = 22%, Q Cochran test p = 0.21) were associated with higher risk of EPB. On average, patients with EPB were older than the remainder (MD for the mean age = 2.82 years, 95%CI = 0.97-4.67, I2 = 0.00%, Q Cochran test p = 0.46). Except for hypertension (meta-analytical RR = 1.33, 95%CI = 1.02-1.73, I2 = 66%, Q Cochran test p < 0.0001), comorbidities were not associated with a higher risk of EPB. CONCLUSION: Preoperative risk factors, including age, gender, hypertension, and revisional bariatric surgery, are associated with early postoperative bleeding after RYGB. Further primary studies, with higher methodological quality, are required to detail more risk factors.

Primary EGIST of the greater omentum - a rare presentation.

Extragastrointestinal stromal tumors (EGISTs) are rare mesenchymal neoplasms, which develop in the retroperitoneum, mesentery, and omentum, lacking continuity to the stomach or intestines. Authors hereby present a female patient with a large heterogeneous abdominal mass as a case of an omental EGIST. A 46-year-old woman was referred to our hospital due to an insidious enlargement and colicky pain in the right iliac fossa. Abdominal palpation revealed a voluminous, freely mobile, and non-pulsatile mesoabdominal bulge expanding to the hypogastrium. On exploratory midline laparotomy, the tumor was densely fused to the greater omentum, not connected to the stomach, without gross involvement of adjacent structures. The large mass was completely excised after adequate mobilization. Immunohistochemical techniques showed strong and diffuse expression of WT1, actin and DOG-1, as well as multifocal c-KIT marking. Mutational study concluded a double mutation of KIT exon 9 and a mutation of PDGFRA exon 18. The patient was submitted to adjuvant treatment with imatinib mesylate 800 mg/day. Despite an extremely diverse presentation, omental EGISTs often remain clinically silent for a long time having enough space to grow before becoming symptomatic. These tumors have a consistent pattern of metastasis that typically spares lymph nodes unlike epithelial gut neoplasms. Surgery remains the preferred treatment for non-metastatic EGISTs of the greater omentum. It is possible that DOG-1 will supplant KIT as the leading marker in the future. The scarcity of knowledge on omental EGISTs implies a close monitoring of these patients to detect local relapse or distant metastasis.

Roux-en-Y gastric bypass and sleeve gastrectomy as revisional bariatric procedures after adjustable gastric banding: a retrospective cohort study.

INTRODUCTION: The frequency of revisional bariatric surgery is increasing, but its effectiveness and safety are not yet fully established. The aim of our study was to compare short-term outcomes of primary (pRYGB and pSG) and revisional bariatric surgeries (rRYGB and rSG). METHODS: We performed a retrospective cohort study assessing all patients submitted to primary and revisional (after a failed AGB) RYGB and SG in 2019. Each patient was followed-up at 6 months and 12 months after surgery. We compared pRYGB vs. rRYGB, pSG vs. rSG and rRYGB vs. rSG on weight loss, surgical complications, and resolution of comorbidities. RESULTS: We assessed 494 patients, of which 18.8% had undergone a revisional procedure. Higher weight loss at 6 and 12 months was observed in patients undergoing primary vs. revisional procedures. Patients submitted to rRYGB lost more weight than those with rSG (%EWL 12 months = 82.6% vs. 69.0%, p < 0.001). Regarding the resolution of obesity-related comorbidities, diabetes resolution was more frequent in pRYGB than rRYGB (54.2% vs. 25.0%; p = 0.038). Also, 41.7% of the patients who underwent rRYGB had dyslipidemia resolution vs. 0% from the rSG group (p = 0.035). Dyslipidemia resolution was also more common in pSG vs. rSG (68.6% vs. 0.0%; p = 0.001). No significant differences in surgical complications were found. CONCLUSION: Revisional bariatric surgery is effective and safe treating obesity and related comorbidities after AGB. Primary procedures appear to be associated with better weight loss outcomes. Further prospective studies are needed to better understand the role of revisional bariatric surgery.

Incidence of symptomatic gallstones after bariatric surgery: the impact of expectant management.

BACKGROUND: Bariatric surgery is the most effective treatment for sustained weight reduction and obesity-related comorbidities. The development of gallstones as a result of rapid weight loss is a well-known consequence of bariatric procedures. It remains unclear, if there is an increased risk of these gallstones becoming symptomatic. METHODS: A retrospective analysis of 505 consecutive patients submitted to either Roux-en-Y Gastric Bypass or Sleeve Gastrectomy between January and December 2019 was performed. The aim of our study was to determine the incidence of symptomatic cholelithiasis in asymptomatic patients with their gallbladder in situ after bariatric surgery and to identify potential risk factors for its development. RESULTS: Of the 505 patients included, 79 (15.6%) underwent either previous cholecystectomy. (n = 67, 84.8%) or concomitant cholecystectomy during bariatric surgery (n = 12, 15.2%). Among the remaining 426 (84.4%) patients, only 8 (1.9%) became symptomatic during the 12-month follow-up period. When compared with patients who remained asymptomatic, they had a higher median preoperative BMI (47.0 vs. 42.8, p = 0.046) and prevalence of cholelithiasis on preoperative ultrasound (62.5% vs. 10.7%, p = 0.001). Multivariate analysis revealed preoperative BMI and cholelithiasis on preoperative ultrasound as independent risk factors for symptomatic biliary disease (OR 1.187, 95%CI 1.025-1.376, p = 0.022 and OR 10.720, 95%CI 1.613-71.246, p = 0.014, respectively). CONCLUSION: Considering a low incidence of symptomatic gallstones after bariatric surgery, concomitant cholecystectomy should only be performed in symptomatic patients undergoing bariatric surgery. Preoperative factors, such as a higher BMI and positive ultrasound for cholelithiasis, may be related to the development of symptomatic gallstones.

Risk and Prophylactic Management of Gallstone Disease in Bariatric Surgery: a Systematic Review and A Bayesian meta-analysis.

BACKGROUND: The frequency and management of gallstone disease (GD) in bariatric patients, including the role of routine prophylactic concomitant cholecystectomy (CCY), are still a matter of debate. This study aims to assess the risk of de novo GD in patients undergoing bariatric surgery (BS) and their predictive factors, as well as mortality and morbidity in prophylactic CCY compared to BS alone. METHODS: We performed a systematic review, searching PubMed, EMBASE, and Web of Science until April 2021. We performed a Bayesian meta-analysis to estimate the risk of GD development after BS and the morbidity and mortality associated with BS alone versus BS + prophylactic CCY. Sources of heterogeneity were explored by meta-regression analysis. RESULTS: The risk of de novo post bariatric GD was 20.7% (95% credible interval [95% CrI] = 13.0-29.7%; I2 = 75.4%), and that of symptomatic GD was 8.2% ([95% CrI] = 5.9-11.1%; I2 = 66.9%). Pre-operative average BMI (OR = 1.04; 95% CrI = 0.92-1.17) and female patients' proportion (OR = 1.00; 95% CrI = 0.98-1.04) were not associated with increased risk of symptomatic GD. BS + prophylactic CCY was associated with a 97% probability of a higher number of postoperative major complications compared to BS alone (OR = 1.74, 95% CrI = 0.97-3.55; I2 = 56.5%). Mortality was not substantially different between the two approaches (OR = 0.79; 95% CrI = 0.03-3.02; I2 = 20.7%). CONCLUSION: The risk of de novo symptomatic GD after BS is not substantially high. Although mortality is similar between groups, odds of major postoperative complications were higher in patients submitted to BS + prophylactic CCY. It is still arguable if prophylactic CCY is a fitting approach for patients with a preoperative lithiasic gallbladder.

A New Differential Diagnosis of Dysphagia: A Case Report of Lymphocytic Esophagitis.

Lymphocytic esophagitis is a rare but increasingly recognized cause of chronic esophagitis. The pathogenesis, prognosis, and treatment are undefined. We report the diagnostic workup of an unusual cause of dysphagia. We present a case report of a 71-year-old female who presented with dysphagia for solid foods. The endoscopic appearance showed stenosis at the cricopharyngeus and trachealization of the proximal esophagus. Biopsies were taken to exclude eosinophilic esophagitis. The pathology showed lymphocytic infiltrate with peripapillary distribution with no granulocytes and spongiosis suggestive of lymphocytic esophagitis. Esomeprazol was started with symptomatic improvement. The symptoms and endoscopic appearance of lymphocytic esophagitis may be indistinguishable from other forms of chronic esophagitis. A high index of suspicion and mucosal sampling are essential to establish the diagnosis. Lymphocytic esophagitis seems to be a chronic and benign form of esophagitis. It should be included in the differential diagnosis of dysphagia. Further research and case reporting are essential to better define its pathogenesis, prognosis, and treatment.

Microwave-assisted catalytic fast pyrolysis of rice husk over a hierarchical HZSM-5/MCM-41 catalyst prepared by organic base alkaline solutions.

This paper reports the results obtained for microwave-assisted catalytic fast pyrolysis (MACFP) of rice husk. The MACFP process employed a hierarchical catalyst prepared via a combination of organic alkali treatment (TPAOH) and the generation of an external layer of MCM-41-type mesoporous channels. We propose this catalyst which is used for the first time for pyrolysis of lignocellulosic biomass, as a tool to reduce coke agglomeration and increase hydrocarbon yields. Our results indicate that during catalyst preparation the mass fraction of cetyltrimethylammonium bromide (CTAB) has a direct effect on the content of MCM-41 formed on top of the HZSM-5 core. For MACFP, we hypothesize that the small molecules generated from thermal decomposition of rice husk react further to form aromatic and aliphatic hydrocarbons by decarbonylation, decarboxylation, oligomerization and aromatization. The highest hydrocarbon yield (60.5%) was obtained for a catalyst modified by a 2.0 mol/L TPAOH solution, with 10 wt% of CTAB (template for producing MCM-41), as well as with digestion and crystallization at 110 °C for 24 h. In addition, the highest liquid yield (47.6 wt%) was obtained at 550 °C. The relative content of hydrocarbons goes through a maximum of 60.5% with CTAB mass fraction which was higher than values obtained with MCM-41 (3.2%) and HZSM-5 (36.0%). Characterization and catalytic testing results suggest that the digestion temperature plays a more important role in the catalyst synthesis than the crystallization temperature. High digestion temperature (120 °C) decreases the overall hydrocarbon selectivity from 60.5% (110 °C) to 39.2%. The relative content of oxygenates reached the lowest value of 35.9% at the digestion and crystallization temperature of 110 °C. The synergistic effect of the MCM-41 shell and the HZSM-5 core promotes the catalytic activity, leading to outstanding deoxygenation capabilities and excellent selectivity to BTEX (52.7%).

Catalytic fast co-pyrolysis of waste greenhouse plastic films and rice husk using hierarchical micro-mesoporous composite molecular sieve.

Catalytic fast co-pyrolysis of waste greenhouse plastic films and rice husk over a hierarchical HZSM-5/MCM-41 catalyst was performed in an analytical Py-GC/MS. We evaluated the effect of pyrolysis temperature and the ratio of rice husk to waste greenhouse plastic films on the total peak area of condensable organic products and CO2. In order to evaluate synergy possibilities among the two feedstocks, we performed non-catalytic pyrolysis and catalytic fast pyrolysis of rice husk and waste greenhouse plastic films separately. In addition, we report results for the catalytic fast co-pyrolysis of the mixture rice husk and waste greenhouse plastic films. The maximum relative content of hydrocarbons from catalytic fast co-pyrolysis of rice husk and waste greenhouse plastic films is obtained at 600 °C. When the mass ratio of rice husk to waste greenhouse plastic films is 1:1.5, the relative content of hydrocarbons reaches a maximum (71.1%). The hierarchical micro-mesoporous composite molecular sieve used in this work has outstanding catalytic activity and increases the relative content of hydrocarbons.

Effect of alkali-treated HZSM-5 zeolite on the production of aromatic hydrocarbons from microwave assisted catalytic fast pyrolysis (MACFP) of rice husk.

We performed microwave-assisted catalytic fast pyrolysis (MACFP) of rice husk (RH) over an alkali-treated HZSM-5 zeolite, for production of hydrocarbons. The treatment consisted in the modification of the HZSM-5 by the organic base tetrapropylammonium hydroxide (TPAOH) solution at several concentrations. We characterized the resulting catalysts by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption, and temperature-programmed sorption of ammonia (NH3-TPD). The results suggest that the TPAOH treatment generated mesoporous structures in the HZSM-5, while preserving its microporous structure and crystallinity. We obtained the highest yield (45.9%) of hydrocarbons from MACFP of rice husk (RH) at 550 °C. As the TPAOH concentration increases, the relative content of BTEX hydrocarbons (benzene, toluene, ethylbenzene, and xylene) reaches a maximum value of 22.9% at 2.0 mol/L. A comparison of results obtained over the organic base TPAOH (HZSM-5 modified by 2.0 mol/L TPAOH solution) with those obtained over an inorganic base (HZSM-5 modified by 2.0 mol/L NaOH solution) shows a 4.3% increase in the relative content of monocyclic aromatic hydrocarbons for the TPAOH. In addition, the TPAOH-treated catalyst shows excellent selectivity of BTEX (58.5%), which is higher than the selectivity obtained with the parent HZSM-5 (51.2%) and NaOH-treated HZSM-5 (53.9%). The TPAOH-modified HZSM-5 catalyst effectively reduced coke formation by 4.6% compared to MACFP over the parent HZSM-5, most likely because TPAOH decreases the concentration of strong acidic sites on the outer surface of the catalyst, creating a mesoporous structure while retaining the weak acidic sites on the HZSM-5 inner surface. The new catalyst generated in this work contains a moderate amount of mesopores structures, which allows for effective upgrading of pyrolysis vapors while simultaneously reducing coke formation, thereby addressing a significant problem in the development of the catalytic fast pyrolysis process.

A conceptual model to assess the impact of anthropogenic drivers on water-related ecosystem services in the Brazilian Cerrado / Um modelo conceitual para avaliar o impacto de fatores antropogênicos nos serviços ecossistêmicos relacionados à água no Cerrado

Abstract: The development of strategies that conciliate anthropogenic activities with nature conservation is becoming increasingly urgent, particularly in regions facing rapid conversion of native vegetation to agriculture. Conceptual modelling enables assessment of how anthropogenic drivers (e.g. land use/land cover change and climate change) modify natural processes, being a useful tool to support strategic decision-making. The present work describes a conceptual model to evaluate water-related ecosystem service provision under different land use scenarios in the Matopiba region of the Brazilian Cerrado, the world's most biodiverse savanna and an agricultural frontier. Model variables were determined (direct drivers, indirect drivers, focal components and responses) and the Nature Futures Framework was consulted to incorporate socio-ecological components and feedbacks. Future scenarios were developed considering potential trajectories of drivers and governance responses that may impact land use in the region, including the possibility of full compliance with Forest Code and implementation of the Soy Moratorium in the region. The conceptual model and scenarios developed in the present study may be useful to improve understanding of the complex interactions among anthropogenic drivers, water-related ecosystem services and their potential repercussions for natural and social systems of the region. Governance decisions will be critical to maintaining the ecosystems of the region, the services it provides and the culture and tradition of the people historically embedded in the landscape. In acknowledgment of humanity's dependence on nature, the importance of inverting the way scenarios are used is highlighted. Rather than using scenarios to measure the impacts of different policy options on nature, scenarios representing the desired outcomes for biodiversity and ecosystem services can be used to inform how policies can guarantee ecosystem integrity into the future.

Resumo: O desenvolvimento de estratégias que conciliem atividades antropogênicas com a conservação da natureza tem se tornado cada vez mais urgente, principalmente em regiões que enfrentam uma rápida conversão da vegetação nativa em agricultura. Modelos conceituais permitem avaliar como fatores antropogênicos (por exemplo, mudança de uso e cobertura do solo e mudanças climáticas) modificam os processos naturais, sendo uma ferramenta útil para apoiar a tomada de decisões estratégicas. O presente trabalho descreve um modelo conceitual para avaliar a provisão de serviços ecossistêmicos relacionados à água sob diferentes cenários de uso do solo na região de Matopiba, no Cerrado, a savana com maior biodiversidade do mundo e uma fronteira agrícola. Foram determinadas as variáveis do modelo (fatores diretos, fatores indiretos, componentes focais e respostas) e o Nature Futures Framework foi consultado para incorporar componentes socioeconômicos e feedbacks. Cenários futuros foram desenvolvidos considerando possíveis trajetórias de fatores antropogênicos e respostas de governança que podem impactar o uso do solo na região, incluindo a possibilidade de cumprimento total do Código Florestal e a implementação da Moratória da Soja na região. O modelo conceitual e os cenários apresentados no presente trabalho podem ser úteis para melhorar a compreensão das complexas interações entre fatores antropogênicos, serviços ecossistêmicos relacionados à água e suas possíveis implicações para os sistemas naturais e sociais da região. Decisões de governança serão críticas para manter os ecossistemas da região, os serviços fornecidos por eles, a cultura e tradição das pessoas historicamente inseridas na paisagem. Em reconhecimento da dependência da humanidade em relação à natureza, destaca-se a importância de inverter a maneira como os cenários são usualmente usados. Em vez de mensurar os impactos de diferentes políticas na natureza, cenários representando os resultados desejados para biodiversidade e serviços ecossistêmicos podem ser usados para informar como políticas podem garantir a integridade dos ecossistemas no futuro.

Leucine Supplementation Improves Effort Tolerance of Rats With Hyperthyroidism.

Leucine is a regulator of protein metabolism in vivo and information on its action on effort tolerance of both animals and humans with hyperthyroidism is scarce. The objective of the present study was to verify the influence of leucine supplementation on the effort tolerance of Wistar rats with experimental hyperthyroidism. 40 animals were divided into four groups of ten: control (C), hormone (H), leucine (L), and hormone + leucine (HL). Hyperthyroidism was induced by daily administration of 20 µâ‹…g100 g-1 of levothyroxine sodium in aqueous suspension by gavage. Leucine was supplemented by adding 5% of the amino acid to the conventional feed. The animals' blood was collected by cardiac puncture to analyze TSH, T4, and T3 levels. The effort tolerance was determined by the swimming test with a 7% load attached to animals' tails. Statistical analysis was performed using the Shapiro-Wilk normality test, followed by the analysis of variance (ANOVA) of repeated measures of two factors (treatment × time) and Tukey post hoc, with a significance level of p < 0.05. Administering thyroid hormone increased the swimming performance of rats after 14 and 21 days, but with a drop in performance at 28 days. The HL group, on the other hand, had a significantly higher swimming performance compared to the other groups after 28 days of treatment. Leucine supplementation associated with the experimental model of hyperthyroidism improved the performance of rats in a swimming test after 28 days of treatment.

Function of neuronal nitric oxide synthase enzyme in temozolomide-induced damage of astrocytic tumor cells.

Astrocytic tumors, including astrocytomas and glioblastomas, are the most common type of primary brain tumors. Treatment for glioblastomas includes radiotherapy, chemotherapy with temozolomide (TMZ) and surgical ablation. Despite certain therapeutic advances, the survival time of patients is no longer than 12-14 months. Cancer cells overexpress the neuronal isoform of nitric oxide synthase (nNOS). In the present study, it was examined whether the nNOS enzyme serves a role in the damage of astrocytoma (U251MG and U138MG) and glioblastoma (U87MG) cells caused by TMZ. First, TMZ (250 µM) triggered an increase in oxidative stress at 2, 48 and 72 h in the U87MG, U251MG and U138MG cell lines, as revealed by 2',7'-dichlorofluorescin-diacetate assay. The drug also reduced cell viability, as measured by MTT assay. U87MG cells presented a more linear decline in cell viability at time-points 2, 48 and 72 h, compared with the U251MG and U138MG cell lines. The peak of oxidative stress occurred at 48 h. To examine the role of NOS enzymes in the cell damage caused by TMZ, N(ω)-nitro-L-arginine methyl ester (L-NAME) and 7-nitroindazole (7-NI) were used. L-NAME increased the cell damage caused by TMZ while reducing the oxidative stress at 48 h. The preferential nNOS inhibitor 7-NI also improved the TMZ effects. It caused a 12.8% decrease in the viability of TMZ-injured cells. Indeed, 7-NI was more effective than L-NAME in restraining the increase in oxidative stress triggered by TMZ. Silencing nNOS with a synthetic small interfering (si)RNA (siRNAnNOShum_4400) increased by 20% the effects of 250 µM of TMZ on cell viability (P<0.05). Hoechst 33342 nuclear staining confirmed that nNOS knock-down enhanced TMZ injury. In conclusion, our data reveal that nNOS enzymes serve a role in the damage produced by TMZ on astrocytoma and glioblastoma cells. RNA interference with nNOS merits further studies in animal models to disclose its potential use in brain tumor anticancer therapy.

The Presence of the Neuronal Nitric Oxide Synthase Isoform in the Intervertebral Disk.

Intervertebral disk degeneration is a progressive and debilitating disease with multifactorial causes. Nitric oxide (NO) might contribute to the cell death pathway. We evaluated the presence of the constitutive form of the neuronal NOS (nNOS) in both health and degenerated intervertebral disk through qPCR and immunohistochemistry. We also analyzed the potential role of nNOS modulation in the tail needle puncture model of intervertebral disk degeneration. Male Wistar rats were submitted to percutaneous disk puncture with a 21-gauge needle of coccygeal vertebras. The selective nNOS pharmacological inhibitor N (ω)-propyl-L-arginine (NPLA) or a nNOS-target siRNA (siRNAnNOShum_4400) was injected immediately after the intervertebral disk puncture with a 30-gauge needle. Signs of disk degeneration were analyzed by in vivo magnetic resonance imaging and histological score. We found that intact intervertebral disks express low levels of nNOS mRNA. Disk injury caused a 4 fold increase in nNOS mRNA content at 5 h post disk lesion. However, NPLA or nNOS-target siRNA slight mitigate the intervertebral disk degenerative progress. Our data show evidence of the nNOS presence in the intervertebral disk and its upregulation during degeneration. Further studies would disclose the nNOS role and its potential therapeutical value in the intervertebral disk degeneration.

Suppression of the Eag1 potassium channel sensitizes glioblastoma cells to injury caused by temozolomide.

Glioblastoma multiforme (GBM) is the most aggressive type of human primary brain tumor. The standard treatment protocol includes radiotherapy in combination with temozolomide (TMZ). Despite advances in GBM treatment, the survival time of patients diagnosed with glioma is 14.5 months. Regarding tumor biology, various types of cancer cell overexpress the ether à go-go 1 (Eag1) potassium channel. Therefore, the present study examined the role of Eag1 in the cell damage caused by TMZ on the U87MG glioblastoma cell line. Eag1 was inhibited using a channel blocker (astemizole) or silenced by a short-hairpin RNA expression vector (pKv10.1-3). pKv10.1-3 (0.2 µg) improved the Eag1 silencing caused by 250 µM TMZ, as determined by reverse transcription-quantitative polymerase chain reaction and immunocytochemistry. Additionally, inhibiting Eag1 with the vector or astemizole (5 µM) reduced glioblastoma cell viability and sensitized cells to TMZ. Cell viability decreased by 63% for pKv10.1-3 + TMZ compared with 34% for TMZ alone, and by 77% for astemizole + TMZ compared with 46% for TMZ alone, as determined by MTT assay. In addition, both the vector and astemizole increased the apoptosis rate of glioblastoma cells triggered by TMZ, as determined by an Annexin V apoptosis assay. Collectively, the current data reveal that Eag1 has a role in the damage caused to glioblastoma by TMZ. Furthermore, suppression of this channel can improve the action of TMZ on U87MG glioblastoma cells. Thus, silencing Eag1 is a promising strategy to improve GBM treatment and merits additional studies in animal models of glioma.

Evaluation of TgH(CX3CR1-EGFP) mice implanted with mCherry-GL261 cells as an in vivo model for morphometrical analysis of glioma-microglia interaction.

BACKGROUND: Glioblastoma multiforme is the most aggressive brain tumor. Microglia are prominent cells within glioma tissue and play important roles in tumor biology. This work presents an animal model designed for the study of microglial cell morphology in situ during gliomagenesis. It also allows a quantitative morphometrical analysis of microglial cells during their activation by glioma cells. METHODS: The animal model associates the following cell types: 1- mCherry red fluorescent GL261 glioma cells and; 2- EGFP fluorescent microglia, present in the TgH(CX3CR1-EGFP) mouse line. First, mCherry-GL261 glioma cells were implanted in the brain cortex of TgH(CX3CR1-EGFP) mice. Epifluorescence - and confocal laser-scanning microscopy were employed for analysis of fixed tissue sections, whereas two-photon laser-scanning microscopy (2P-LSM) was used to track tumor cells and microglia in the brain of living animals. RESULTS: Implanted mCherry-GL261 cells successfully developed brain tumors. They mimic the aggressive behavior found in human disease, with a rapid increase in size and the presence of secondary tumors apart from the injection site. As tumor grows, mCherry-GL261 cells progressively lost their original shape, adopting a heterogeneous and diffuse morphology at 14-18 d. Soma size increased from 10-52 µm. At this point, we focused on the kinetics of microglial access to glioma tissues. 2P-LSM revealed an intense microgliosis in brain areas already shortly after tumor implantation, i.e. at 30 min. By confocal microscopy, we found clusters of microglial cells around the tumor mass in the first 3 days. Then cells infiltrated the tumor area, where they remained during all the time points studied, from 6-18 days. Microglia in contact with glioma cells also present changes in cell morphology, from a ramified to an amoeboid shape. Cell bodies enlarged from 366 ± 0.0 µm(2), in quiescent microglia, to 1310 ± 146.0 µm(2), and the cell processes became shortened. CONCLUSIONS: The GL261/CX3CR1 mouse model reported here is a valuable tool for imaging of microglial cells during glioma growth, either in fixed tissue sections or living animals. Remarkable advantages are the use of immunocompetent animals and the simplified imaging method without the need of immunohistochemical procedures.

Efficacy of several vaccination programmes in commercial layer and broiler breeder hens against experimental challenge with Salmonella enterica serovar Enteritidis.

Two experiments were performed to evaluate the protective effect of various vaccination combinations given at 5 and 9 weeks of age against experimental challenge with Salmonella enterica serovar Enteritidis (SE) phage type 4 at 12 weeks of age. In Experiment 1, groups of commercial layers were vaccinated by one of the following programmes: Group 1, two doses of a SE bacterin (Layermune SE); Group 2, one dose of a live Salmonella enterica serovar Gallinarum vaccine (Cevac SG9R) followed by one dose of the SE bacterin; Group 3, one dose of each of two different multivalent inactivated vaccines containing SE cells (Corymune 4K and Corymune 7K; and Group 4, unvaccinated, challenged controls. In Experiment 2, groups of broiler breeders were vaccinated by the same programmes as Groups 1 and 2 above while Group 3 was an unvaccinated, challenged control group. All vaccination programmes and the challenge induced significant (P < 0.05) seroconversion as measured by enzyme-linked immunosorbent assay. Overall, in both experiments, all vaccination schemes were significantly effective in reducing organ (spleen, liver and caeca) colonization by the challenge strain as well as reducing faecal excretion for at least 3 weeks. Vaccinated layers in Groups 1 and 2 and broiler breeders in Group 2 showed the greatest reduction in organ colonization and the least faecal excretion. In Experiment 1, layers vaccinated with multivalent inactivated vaccines containing a SE component (Group 3) were only moderately protected, indicating that such a vaccination programme may be useful in farms with good husbandry and housing conditions and low environmental infectious pressure by Salmonella.