Inhibitory effect of deferoxamine on Paracoccidioides brasiliensis survival in human monocytes: reversal by holotransferrin not by apotransferrin

The mechanisms used by Paracoccidioides brasiliensis to survive into phagocytic cells are not clear. Cellular iron metabolism is of critical importance to the growth of several intracellular pathogens whose capacity to multiply in mononuclear phagocytes is dependent on the availability of intracellular iron. Thus, the objective of this paper was to investigate the role of intracellular iron in regulating the capacity of P. brasiliensis yeast cells to survive within human monocytes. Treatment of monocytes with deferoxamine, an iron chelator, suppressed the survival of yeasts in a concentration-dependent manner. The effect of deferoxamine was reversed by iron-saturated transferrin (holotransferrin) but not by nonsaturated transferrin (apotransferrin). These results strongly suggest that P. brasiliensis survival in human monocytes is iron dependent.

The inhibitory activity of synthetic compounds and ions against transporters of multi-drug resistant bacteria

RESUMO: Sessenta e três derivados de hidantoína foram utilizados para avaliar possíveis efeitos de modulação na actividade das bombas de efluxo (BE) na Salmonella NCTC 13349 utilizando um método fluorimétrico semi-automático. Nenhum dos compostos apresentaram actividade anti-bacteriana até concentrações de 240 mg/L. Entre todos os compostos, SZ-7 demonstrou possuir propriedades de modulação de effluxo na presença de glucose. Para testar esta actividade, estirpes de Salmonella resistentes à ciprofloxacina, induzidas a elevados níveis de resistência com sobre-expressão de BE, foram expostas ao SZ-7. Este derivado afectou a susceptibilidade das estirpes à ciprofloxacina. Uma vez que os 63 compostos estudados apresentaram pouco efeito inibitório /cumulativo, apesar de serem conhecidos pelos seus efeitos moduladores de BE-dependentes de iões em eucariotas, foi questionado o papel dos iões na regulação de BE bacterianas, que poderão influenciar a eficácia de novos compostos. Para este estudo, utilizamos a Escherichia coli AG100 como modelo, devido ao extenso conhecimento no que respeita a estrutura e actividade das BE. Devido à importância de iões de cálcio (Ca2+) nos canais de transporte membranar e na actividade de ATPases, a sua actividade na modulação do efluxo foi investigada. De resultados anteriormente obtidos concluiu-se que a pH 5 o efluxo é independente de energia metabólica; contudo, a pH 8 é absolutamente dependente, sendo que o Ca2+ é indispensável para manter a actividade das ATPases bacterianas. A acumulação/effluxo de EtBr pela E. coli AG100 foi determinada na presença/ausência de Ca2+, clorpromazina (inibidor de ligação de Ca2+ a proteínas), e ácido etilenodiamino tetra-acético (quelante de Ca2+). Acumulação/effluxo aumentou a pH 8, contudo o Ca2+ reverte estes efeitos evidenciando a sua importância no funcionamento das BE bacterianas. Em resumo este trabalho colocou em evidência que muitos aspectos bioquímicos e bioenergéticos devem ser tomados em consideração no estudo da resistência bacteriana mediada por BE.------- ABSTRACT: Sixty-three hydantoin derivatives were evaluated for their modulating effects on efflux pump (EP) activity of Salmonella NCTC 13349 utilizing a semi-automatic fluorometric method. None of the compounds presented antibacterial activities at concentrations as high as 240 mg/L. Among all compounds, SZ-7 showed possible efflux modulating activity in the presence of glucose, indicative of a potential EP inhibitor. To verify its potential effects, ciprofloxacin-resistant Salmonella strains, induced to high level resistance with over-expressing EPs, were exposed to SZ-7. This derivative affected the susceptibility of the ciprofloxacin-resistant strains. Since the 63 compounds studied had very low inhibitory/accumulative effects, even though their known for being efficient in modulating ion-driven eukaryotic EPs, we questioned whether ions had a leading role in regulating bacterial EPs, influencing the effectiveness of new compounds. For this study we used Escherichia coli AG100 as a model, due to the extensive knowledge on its EPs structure and activity. Owing the importance of calcium ions (Ca2+) for membrane transport channels and activity of ATPases, the role of Ca2+ was investigated. From previous results we concluded that at pH 5 efflux is independent of metabolic energy; however, at pH 8 it is entirely dependent of metabolic energy and the Ca2+ ions are essential to maintain the activity of bacterial ATPases. Accumulation and efflux of ethidium bromide (EtBr) by E. coli AG100 was determined in the presence and absence of Ca2+, chlorpromazine (inhibitor of Ca2+-binding to proteins), and ethylenediaminetetraacetic acid (Ca2+ chelator). Accumulation of EtBr increased at pH 8; however Ca2+ reversed these effects providing information as to the importance of this ion in the regulation of bacterial EP systems. Overall this work puts in evidence that many biochemical and bioenergetic aspects related to the strains physiology need to be taken into consideration in bacterial drug resistance mediated by EPs.

High prevalence of dna from non-H. pylori helicobacters in the gastric mucosa of venezuelan pet dogs and its histological alterations

Non-H. pylori helicobacters (NHPH) have been demonstrated as gastric spiral-shaped bacteria in specimens obtained from dogs; however, their roles in the pathogenesis of upper gastrointestinal disease have not yet been clearly established. The purpose of this study was to evaluate the prevalence of NHPH DNA in the gastric mucosa of dogs and its association with histopathology. Helicobacter was detected through histopathological techniques, PCR, and FISH analysis from fundic biopsies of twenty dogs with or without signs of gastrointestinal disease. PCR and FISH were based on partial 16S rRNA gene sequences. Nineteen dogs showed mild to marked gastritis in the fundus, and only one dog had a healthy gastric mucosa. NHPH DNA was detected in 18 dogs with gastritis and one with normal gastric mucosa. However, there was no significant correlation between the presence of NHPH DNA and the degree of gastritis. These results show a high prevalence of NHPH DNA in the gastric mucosa of dogs from Venezuela. Further studies are necessary to determine a possible association between a specific NHPH species and the degree of gastritis.

Gastric Outlet Obstruction in a Patient with Bouveret's Syndrome: a Case Report

BACKGROUND: Gallstone ileus accounts for 1% to 4% of cases of mechanical bowel obstruction, but may be responsible for up to 25% of cases in older age groups. In non-iatrogenic cases, gallstone migration occurs after formation of a biliary-enteric fistula. In fewer than 10% of patients with gallstone ileus, the impacted gallstones are located in the pylorus or duodenum, resulting in gastric outlet obstruction, known as Bouveret's syndrome. CASE PRESENTATION: We report an 86-year-old female who was admitted to hospital with a 10-day history of persistent vomiting and prostration. She was in hypovolemic shock at the time of arrival in the emergency department. Investigations revealed a gallstone in the duodenal bulb and a cholecystoduodenal fistula. She underwent surgical gastrolithotomy. Unfortunately, she died of aspiration pneumonia on the fourth postoperative day. CONCLUSION: This case shows the importance of considering Bouveret's syndrome in the differential diagnosis of gastric outlet obstruction, especially in the elderly, even in patients with no previous history of gallbladder disease.

One Anastomosis Gastric Bypass versus Roux en Y Gastric Bypass as Salvage Technique after Failed Gastric Band: a Retrospective Analysis of 80 Cases

The classical “Roux en Y Gastric Bypass” (RYGBP) is still the standard technique between all the ones being used nowadays. The “One anastomosis gastric bypass” (OAGBP), is an evolution of the “Minigastic bypass” described by Robert Rutledge in 2001, is a well known and progressively frequent but still controversial technique. In our group, after an experience of 10 years using the RYGBP as a salvage surgery after failed gastric banding, in 132 cases, we decided to adopt the OAGBP as our preferential bariatric technique also in this situation. The theoretical main reasons for that shift are related to the increased safety, maximized weight loss, long term weight loss maintenance and reversibility of the operation. Method: Retrospectively we evaluated data of the surgical management of revisional cases for conversion, after failed or complicated gastric bands to gastric bypass. We selected the last 40 cases of each technique since May 2010. Results: All cases were performed by laparoscopy without any conversion. In both groups the conversion has been performed in one single step (17 cases, 42,5%). Data showed lower morbidity with OAGBP (2,5% against 7,5%) and better weight loss in theOAGBP cohort after a median follow up of 16months (67%against 55%) in patients revised after gastric band failure or complications. None had statistic significance (p>0,1) by the chi-square contingency table analysis.Conclusion: It seems to there is a difference in favour of OAGBP for conversion of complicated gastric bands. In this study we didn’t found statistic significance probably because of the short numbers. Prospective and more powerful studies are necessary to evaluate the benefit of the studied procedure.

Curcumin Inhibits Gastric Inflammation Induced by Helicobacter Pylori Infection in a Mouse Model

Helicobacter pylori (H. pylori) infection triggers a sequence of gastric alterations starting with an inflammation of the gastric mucosa that, in some cases, evolves to gastric cancer. Efficient vaccination has not been achieved, thus it is essential to find alternative therapies, particularly in the nutritional field. The current study evaluated whether curcumin could attenuate inflammation of the gastric mucosa due to H. pylori infection. Twenty-eight C57BL/6 mice, were inoculated with the H. pylori SS1 strain; ten non-infected mice were used as controls. H. pylori infection in live mice was followed-up using a modified 13C-Urea Breath Test (13C-UBT) and quantitative real-time polymerase chain reaction (PCR). Histologically confirmed, gastritis was observed in 42% of infected non-treated mice at both 6 and 18 weeks post-infection. These mice showed an up-regulation of the expression of inflammatory cytokines and chemokines, as well as of toll-like receptors (TLRs) and MyD88, at both time points. Treatment with curcumin decreased the expression of all these mediators. No inflammation was observed by histology in this group. Curcumin treatment exerted a significant anti-inflammatory effect in H. pylori-infected mucosa, pointing to the promising role of a nutritional approach in the prevention of H. pylori induced deleterious inflammation while the eradication or prevention of colonization by effective vaccine is not available.

Gastric adenocarcinoma: contribute of computed tomography in preoperative T nad N staging

RESUMO:Os recentes progressos na imagiologia médica possibilitaram um papel de destaque para a Tomografia Axial Computorizada Multicorte no estadiamento do carcinoma do estômago (GA). Foi objetivo deste estudo avaliar a acuidade desta técnica no estadiamento T (invasão mural) e N (ganglionar) e avaliar fatores de prognóstico como fatores de representação/substituição para melhorar a referida acuidade. Sessenta e nove pacientes operados a carcinoma gástrico (GA) entre Janeiro de 2010 e Julho de 2012 e avaliados por Tomografia Computorizada, a maioria recorrendo a técnica de multicorte com distensão gástrica, foram estadiados retrospetivamente por três imagiologistas. Utilizaram-se critérios de avaliação referidos na literatura especializada e fatores de substituição/representação nos estadios menos eficazes. O estadiamento T revelou acuidade de 66,7% e sensibilidade de 92% e a acuidade, sensibilidade e especificidade obtidas para o estadiamento N foram respetivamente 49%, 40,9% e 64%. Usando um fator de substituição de estadiamento diagnóstico T4/N2 para mudar o estadiamento N2 obtido por MDCT para estadiamento N3A aumentaria a acuidade do estadiamento N para 59% e a sensibilidade para 58,1% e baixaria a especificidade para 61,5%, embora essa mudança não fosse estatisticamente significativa (Teste exato de Fisher 0,159). Em conclusão a acuidade de uma técnica simples de MDCT com distensão gástrica no estadiamento T e N do GA está dentro dos valores citados na literatura e fatores de substituição/representação como o estadiamento T4 e o tipo Difuso da classificação de Lauren podem melhorar a acuidade do estadiamento N.-------------- ABSTRACT: Recent innovations in medical sectional imaging have allowed a major role of multi-detector computed tomography (MDCT) in staging of gastric adenocarcinoma (GA). The purpose of this study was to evaluate the accuracy of this technique in depth of mural invasion (T) and nodal (N) staging of GA and to evaluate prognostic factors as surrogate factors to improve such accuracy. Sixty nine patients operated to GA between January 2010 and July 2012 that underwent Computed Tomography, the majority through Multidetector Computed Tomography (MDCT) with gastric distention, were staged retrospectively by three imagiologists with state-of-the-art criteria and surrogate prognostic factors were analyzed for less accurate stages. MDCT T-staging was 66,7 % accurate with a sensibility of 92 % and there was a 49 % accuracy, 40,9 % sensibility and 64 % specificity for N Staging. Using a surrogate factor of T4/N2 diagnostic staging to change diagnostic MDCT N2 disease to N3A disease would increase accuracy of N staging to 59% and sensibility to 58,1% and would decrease specificity to 61,5 %, although that change was not statistically significant (Fisher´s Exact Test 0,159)In conclusion the accuracy of a simple hydro-MDCT technique in T and N staging of GA is in the range of values cited in the literature and surrogate factors as diagnostic T4 disease and diffuse type of Lauren´s Classification may improve the accuracy of N staging.

Endoscopic Treatment of Early Gastric Obstruction After Sleeve Gastrectomy: Report of Two Cases

Morbid obesity is an epidemic and complex disease which imposes a multidisciplinary approach. Laparoscopic sleeve gastrectomy has become a frequent procedure given its effi- cacy and safety compared to other surgical options. However, it isn’t free from complications. Lax gastric fixation or incorrect positioning of the stomach during surgery can result in early gastric outlet obstruction caused by a volvulus-like mechanism by rotation of the stomach around its anatomic axes. This report refers to two cases of post sleeve gastric torsion resulting in persisting vomiting after initiating oral intake. The diagnosis was confirmed by upper gastrointestinal-contrast study and gastroscopy. In both cases, a fully covered self-expandable metallic stentwas insertedwhich prompted the gastric lumen to become permeable resulting in symptomatic resolution. The stents were removed endoscopically aftertwo and three months. Beyond more than three years offollow-up,the patients remain asymptomatic and no recurring ‘‘stenosis’’ was noticed.In these cases the use offully covered self-expandable metallic stents demonstrated to be effective and safe in the treatment of post sleeve gastric torsion.

Epstein-Barr virus-positive gastric cancer: a distinct molecular subtype of the disease?

Abstract: Approximately 90% of the world population is infected by Epstein-Barr virus (EBV). Usually, it infects B lymphocytes, predisposing them to malignant transformation. Infection of epithelial cells occurs rarely, and it is estimated that about to 10% of gastric cancer patients harbor EBV in their malignant cells. Given that gastric cancer is the third leading cause of cancer-related mortality worldwide, with a global annual incidence of over 950,000 cases, EBV-positive gastric cancer is the largest group of EBV-associated malignancies. Based on gene expression profile studies, gastric cancer was recently categorized into four subtypes; EBV-positive, microsatellite unstable, genomically stable and chromosomal instability. Together with previous studies, this report provided a more detailed molecular characterization of gastric cancer, demonstrating that EBV-positive gastric cancer is a distinct molecular subtype of the disease, with unique genetic and epigenetic abnormalities, reflected in a specific phenotype. The recognition of characteristic molecular alterations in gastric cancer allows the identification of molecular pathways involved in cell proliferation and survival, with the potential to identify therapeutic targets. These findings highlight the enormous heterogeneity of gastric cancer, and the complex interplay between genetic and epigenetic alterations in the disease, and provide a roadmap to implementation of genome-guided personalized therapy in gastric cancer. The present review discusses the initial studies describing EBV-positive gastric cancer as a distinct clinical entity, presents recently described genetic and epigenetic alterations, and considers potential therapeutic insights derived from the recognition of this new molecular subtype of gastric adenocarcinoma.

Fatal pulmonary thromboembolism in gastrectomy intraoperative procedures by gastric adenocarcinoma: case report

The case of a patient with gastric adenocarcinoma with indication for gastrectomy is reported. The surgery took place without complications. A palliative, subtotal gastrectomy was performed after para-aortic lymph nodes compromised by neoplasm were found, which was confirmed by pathological exam of frozen sections carried out during the intervention. At the end of the gastroenteroanastomosis procedure, the patient began to show intense bradycardia: 38 beats per minute (bpm), arterial hypotension, changes in the electrocardiogram's waveform (upper unlevelling of segment ST), and cardiac arrest. Resuscitation maneuvers were performed with temporary success. Subsequently, the patient had another circulatory breakdown and again was recovered. Finally, the third cardiac arrest proved to be irreversible, and the intra-operative death occurred. Necropsy showed massive pulmonary embolism. The medical literature has recommended heparinization of patients, in an attempt to avoid pulmonary thromboembolism following major surgical interventions. However, in the present case, heparinization would have been insufficient to prevent death. This case indicates that it is necessary to develop preoperative propedeutics for diagnosing the presence of venous thrombi with potential to migrate, causing pulmonary thromboembolism (PTE). If such thrombi could be detected, preventative measures, such as filter installation in the Cava vein could be undertaken.