Variants in ABCG8 and TRAF3 genes confer risk for gallstone disease in admixed Latinos with Mapuche Native American ancestry.

Latin Americans and Chilean Amerindians have the highest prevalence of gallstone disease (GSD) and gallbladder cancer (GBC) in the world. A handful of loci have been associated with GSD in populations of predominantly European ancestry, however, they only explain a small portion of the genetic component of the disease. Here, we performed a genome-wide association study (GWAS) for GSD in 1,095 admixed Chilean Latinos with Mapuche Native American ancestry. Disease status was assessed by cholecystectomy or abdominal ultrasonography. Top-10 candidate variants surpassing the suggestive cutoff of P < 1 × 10-5 in the discovery cohort were genotyped in an independent replication sample composed of 1,643 individuals. Variants with positive replication were further examined in two European GSD populations and a Chilean GBC cohort. We consistently replicated the association of ABCG8 gene with GSD (rs11887534, P = 3.24 × 10-8, OR = 1.74) and identified TRAF3 (rs12882491, P = 1.11 × 10-7, OR = 1.40) as a novel candidate gene for the disease in admixed Chilean Latinos. ABCG8 and TRAF3 variants also conferred risk to GBC. Gene expression analyses indicated that TRAF3 was significantly decreased in gallbladder (P = 0.015) and duodenal mucosa (P = 0.001) of GSD individuals compared to healthy controls, where according to GTEx data in the small intestine, the presence of the risk allele contributes to the observed effect. We conclude that ABCG8 and TRAF3 genes are associated with GSD and GBC in admixed Latinos and that decreased TRAF3 levels could enhance gallbladder inflammation as is observed in GSD and GSD-associated GBC.

Is intestinal oxidative stress involved in patients with compensated liver cirrhosis?

BACKGROUND: Liver cirrhosis is associated with intestinal epithelial barrier dysfunction, which may be affected by oxidative stress. Studies in cirrhotic rats provided evidence for intestinal oxidative stress, but studies in cirrhotic patients are scarce. We have shown intestinal barrier dysfunction in patients with compensated cirrhosis. AIM: The present study aimed to investigate whether oxidative stress occurs in the intestinal mucosa of compensated cirrhotic patients and may contribute to barrier dysfunction. MATERIAL AND METHODS: Oxidative stress was studied in duodenal and sigmoid biopsies from 15 cirrhotic patients and 22 controls by analyzing transcription of genes involved in glutathione and uric acid metabolism using quantitative real-time polymerase chain reaction. Protein levels of glutathione and glutathione disulphide were measured and the glutathione/glutathione disulphide ratio was calculated as marker of oxidative stress. In addition, intestinal myeloperoxidase and fecal calprotectin were determined. RESULTS: Gene transcription of glutathione synthetase and glutathione reductase were significantly different in duodenal and sigmoid biopsies of cirrhotic patients vs. controls, but no alterations were found for other genes nor for glutathione, glutathione disulphide, glutathione/glutathione disulphide ratio and intestinal myeloperoxidase and fecal calprotectin concentrations. CONCLUSION: This study did not find indications for oxidative stress and low-grade inflammation in the small and large intestine of stable compensated cirrhotic patients. Although these preliminary findings need further validation, we found intestinal oxidative stress not to be a major mechanism contributing to epithelial barrier dysfunction in patients with compensated cirrhosis.

Intestinal mucosal proliferation, apoptosis and oxidative stress in patients with liver cirrhosis.

BACKGROUND: Intestinal mucosal barrier dysfunction in liver cirrhosis and its implicated mechanisms is of great clinical importance because it is associated with the development of serious complications from diverse organs through promotion of systemic endotoxemia. AIM: The present study was designed to investigate whether enterocytes' proliferation, apoptosis and intestinal oxidative stress are altered in the intestinal mucosa of patients with compensated and decompensated liver cirrhosis. MATERIAL AND METHODS: Twelve healthy controls (group A) and twenty four cirrhotic patients at a compensated (n = 12, group B) or decompensated condition (n = 12, group C) were subjected to duodenal biopsy. In intestinal specimens mucosal apoptotic and mitotic activity and their ratio were recorded by means of morphological assessment and mucosal lipid hydroperoxides were measured. Plasma endotoxin concentration, an index of gut barrier function, was also determined. RESULTS: Cirrhotic patients presented significantly higher serum endotoxin concentrations as compared to healthy controls (P < 0.001), whilst endotoxemia was higher in decompensated disease (P < 0.05 vs. compensated cirrhosis). Intestinal mucosal mitotic count was significantly lower in patients with compensated and decompensated cirrhosis compared to controls (P < 0.01, respectively), whilst a trend towards increased apoptosis was recorded. The mitotic/apoptotic ratio was significantly reduced in groups B (P < 0.05) and C (P < 0.01) as compared to controls. Intestinal lipid peroxidation was significantly increased in decompensated cirrhotics (P < 0.001 vs. groups A and B). CONCLUSIONS: The present study demonstrates for the first time that human liver cirrhosis is associated with decreased intestinal mucosal proliferation and proliferation/apoptosis ratio even at early stages of cirrhosis and increased intestinal oxidative stress in advanced liver disease.

Duodenal intraepithelial lymphocytes of children with cow milk allergy preferentially bind the glycan-binding protein galectin-3.

A breakdown in intestinal homeostasis results in inflammatory bowel diseases including coeliac disease and allergy. Galectins, evolutionarily conserved beta-galactoside-binding proteins, can modulate immune-epithelial cell interactions by influencing immune cell fate and cytokine secretion. In this study we investigated the glycosylation signature, as well as the regulated expression of galectin-1 and -3 in human duodenal samples of allergic and non-allergic children. Whereas galectin-1 was predominantly localized in the epithelial compartment (epithelial cells and intraepithelial lymphocytes) and the underlying lamina propria (T cells, macrophages and plasma cells), galectin-3 was mainly expressed by crypt epithelial cells and macrophages in the lamina propria. Remarkably, expression of these galectins was not significantly altered in allergic versus non-allergic patients. Investigation of the glycophenotype of the duodenal inflammatory microenvironment revealed substantial alpha2-6-linked sialic acid bound to galactose in lamina propria plasma cells, macrophages and intraepithelial lymphocytes and significant levels of asialo core 1 O-glycans in CD68+ macrophages and enterocytes. Galectin-1 preferentially bound to neutrophils, plasma cells and enterocytes, while galectin-3 binding sites were mainly distributed on macrophages and intraepithelial lymphocytes. Notably, galectin-3, but not galectin-1 binding, was substantially increased in intraepithelial gut lymphocytes of allergic patients compared to non-allergic subjects, suggesting a potential role of galectin-3-glycan interactions in shaping epithelial-immune cell connections during allergic inflammatory processes.

An immunocytochemical study of the endocrine cells in the stomach and duodenum of Zonotrichia capensis subtorquata (Passeriformes, Emberizidae).

The main purpose of this study was to evaluate the regional distribution pattern and relative frequency of some endocrine cells in the three portions of the gastrointestinal tract (GIT)--the proventriculus, gizzard and duodenum- of the rufous-collared sparrow (Zonotrichia capensis subtorquata), by immunohistochemical methods using six types of polyclonal antisera, specific for serotonin (5-HT), somatostatin (D cells), glucagon, motilin, polypeptide YY (PYY) and insulin. In the proventriculus, endocrine cells immunoreactive for all of these markers were observed. The somatostatin-immunoreactive cells were found with greater frequency, with the presence of cytoplasmic processes. In the gizzard, endocrine cells secreting somatostatin, 5-HT and PYY were detected, while those secreting glucagon and insulin were not. In the final part of the gizzard, endocrine cells secreting 5-HT were more frequent, and cells secreting somatostatin and insulin were not detected. All of the cell types studied were observed in the duodenum in different frequencies, except for cells immunoreactive for glucagon and insulin. The somatostatin-positive (D cells) were the most numerous, being more prevalent in the intestinal glands. The other endocrine cells were identified in smaller numbers, some of them located in the intestinal villi and Lieberkuhn glands. The finding of these cell types in the duodenum confirms their preferential location in the final portions of the principal segments of the digestive system and suggests control by feedback of its functions. In conclusion, some interesting distributional patterns of gastrointestinal endocrine cells were found in this species of sparrow.

1alpha,25(OH)(2)-Vitamin D(3) stimulates intestinal cell p38 MAPK activity and increases c-Fos expression.

In intestinal cells, as in other target cells, the steroid hormone 1alpha,25(OH)(2)-Vitamin D(3) (1alpha,25(OH)(2)D(3)) regulates gene expression via the specific intracellular Vitamin D receptor and induces fast non-transcriptional responses involving stimulation of transmembrane signal transduction pathways. We have previously shown that the hormone activates the extracellular signal-regulated mitogen-activated protein (MAP) kinase isoforms ERK1 and ERK2 in rat intestinal cells. In the present study, we have demonstrated that 1alpha,25(OH)(2)D(3) also induces the phosphorylation and activation of p38 MAPK in these cells. The hormone effects were time and dose-dependent, with maximal stimulation at 2min (+3-fold) and 1nM. 1alpha,25(OH)(2)D(3)-dependent p38 phosphorylation was suppressed by SB 203580, a selective inhibitor of p38 MAPK. Ca(2+) chelation with EGTA, inhibition of the c-Src-tyrosine kinase family with PP1 or protein kinase A (PKA) with Rp-cAMP, attenuated hormone activation of p38 MAPK. The physiological significance of 1alpha,25(OH)(2)D(3)-dependent activation of ERK1/2 and p38 MAP kinases was addressed by monitoring c-Fos expression. Incubation of intestinal cells with the hormone was followed by a rapid induction of c-Fos expression which was blocked by SB 203580 and partially suppressed by the ERK1/2 inhibitor PD 98059. Our results suggest that 1alpha,25(OH)(2)D(3) activates p38 MAPK, involving Ca(2+), c-Src and PKA as upstream regulators, and that p38 MAPK has a central role in hormone-induction of the oncoprotein c-Fos in rat intestinal cells.

The use of secondary ion mass spectrometry (SIMS) to evaluate internal contamination.

Secondary ion mass spectrometry (SIMS) permits the detection of stable and radioactive elements in microvolume. Based on the ablation of specimens by ion bombardment, this mass spectrometry method allows a rapid assessment of trace elements in biological samples and enables accurate isotopic ratio determination. In this work, an application of SIMS in studies involving element microdistribution is illustrated on the basis of analyses of duodenal tissue sections from rats contaminated with either cerium or thorium. For this purpose, tests are performed with SIMS to analyze tissue sections obtained 12, 24 and 48 hr after contamination. In this report, strengths and limitations of SIMS are pointed out as an important tool in biological research.

Arrangement of the collagen and elastic fibers in the upper human duodenum.

The arrangement of the elastic and collagen fibers in the upper human duodenum was examined. These fibers lie parallel to the muscle fibers in the tunica muscularis. In the submucosa they form a pantographic network arrangement, the cross-over angles of which increase in the oro-aboral direction. The collagen and elastic fibers show a polar orientation among the muscle fibers.

Investigaciones de los neurotransmisores 5-hidroxitriptamina, noradrenalina y dopamina, en mucosa gastroduodenal: correlación clínica e histológica / Determination of the neurotransmitters 5-hydroxytryptamine, noradrenaline, and dopamine in gastroduodenal mucosa: clinical and histologic correlation

Se estudiaron las concentraciones (pg/mg de tejido de los neurotransmisores (NT) 5-Hidroxitriptamina (5HT), Noradrenalina (NA) y Dopamina (DA) en mucosa del fundus gástrico (F), antro (A) y bulbo duodenal (D) de 21 paciente con mucosa normal y con diversos grados de inflamación crónica. Se correlacionaron las concentraciones de los NT entre sí, en conjuntos en cada región y con parámetros clínicos, de motilidad indirectos e histológicos. Los valores promedios hallados en cada región fueron para 5HT: F=940+/-457, en A=787+/-407 y en D=601+/-272; para NA en F=217+/-138, en A=228+/-126 y en D=245+/-118; y para DA en F=50+/-32, en A=46+/-31 y en D=53+/-45. Se observó que a mayores infiltrados inflamatorios en bulbo duodenal se encontraron mayores concentraciones de DA (r=0,94). Ningún otro parámetro tuvo relación significativa con las variaciones de los NT. Se pudo establecer que las variaciones de las concentraciones de los NT de la mucosa del antro gástrico están más asociadas a las del bulbo duodenal que a las del fundus gástrico (AU)

Investigaciones de los neurotransmisores 5-hidroxitriptamina, noradrenalina y dopamina, en mucosa gastroduodenal: correlación clínica e histológica / Determination of the neurotransmitters 5-hydroxytryptamine, noradrenaline, and dopamine in gastroduodenal mucosa: clinical and histologic correlation

Se estudiaron las concentraciones (pg/mg de tejido de los neurotransmisores (NT) 5-Hidroxitriptamina (5HT), Noradrenalina (NA) y Dopamina (DA) en mucosa del fundus gástrico (F), antro (A) y bulbo duodenal (D) de 21 paciente con mucosa normal y con diversos grados de inflamación crónica. Se correlacionaron las concentraciones de los NT entre sí, en conjuntos en cada región y con parámetros clínicos, de motilidad indirectos e histológicos. Los valores promedios hallados en cada región fueron para 5HT: F=940+/-457, en A=787+/-407 y en D=601+/-272; para NA en F=217+/-138, en A=228+/-126 y en D=245+/-118; y para DA en F=50+/-32, en A=46+/-31 y en D=53+/-45. Se observó que a mayores infiltrados inflamatorios en bulbo duodenal se encontraron mayores concentraciones de DA (r=0,94). Ningún otro parámetro tuvo relación significativa con las variaciones de los NT. Se pudo establecer que las variaciones de las concentraciones de los NT de la mucosa del antro gástrico están más asociadas a las del bulbo duodenal que a las del fundus gástrico

[Determination of the neurotransmitters 5-hydroxytryptamine, noradrenaline, and dopamine in gastroduodenal mucosa. Clinical and histologic correlation]. / Investigaciones de los neurotransmisores 5-hidroxitriptamina, noradrenalina y dopamina, en mucosa gastroduodenal. Correlación clínica e histológica.

We have studied the concentrations (pg/mg) of Neurotransmitters 5-hydroxytryptamine (5HT), Noradrenaline (NA) and Dopamine (DA) at mucosa normal and with different degrees of chronic inflammation mucosa of fundus (F), antrum (A) and duodenum (D) in 21 patients. We correlated the concentration of the neurotransmitters with each other, all of them in each region and with clinics, indirect of motility and histologic parameters. The average for 5HT in F: 940.2 +/- 457.4; in A: 787.5 +/- 407.0; in D: 601.6 +/- 272.0; for NA in F: 217.5 +/- 138.7; in A: 228.4 +/- 126.5; in D: 245.7 +/- 118.6 for DA in F: 50.7 +/- 32.2; in A: 46.3 +/- 31.5; in D: 53.0 +/- 45.6. The statistical analysis showed a significant correlation of DA concentration with lymphoplasmocytic infiltrated in Duodenum (r = 0,94). not any other parameter had significative relation with the neurotransmitters variations. We established that the variations of the neurotransmitter concentrations of the antrum mucosa are more associated with the duodenum than with the gastric fundus.