Genetic structure of Argentinean hexaploid wheat germplasm.

The identification of genetically homogeneous groups of individuals is an ancient issue in population genetics and in the case of crops like wheat, it can be valuable information for breeding programs, genetic mapping and germplasm resources. In this work we determined the genetic structure of a set of 102 Argentinean bread wheat (Triticum aestivum L.) elite cultivars using 38 biochemical and molecular markers (functional, closely linked to genes and neutral ones) distributed throughout 18 wheat chromosomes. Genetic relationships among these lines were examined using model-based clustering methods. In the analysis three subpopulations were identified which correspond largely to the origin of the germplasm used by the main breeding programs in Argentina.

Identification of leaf rust resistance genes in selected Argentinean bread wheat cultivars by gene postulation and molecular markers

Leaf rust, caused by Puccinia triticina Eriks. is a common and widespread disease of bread wheat (Triticum aestivum L.), in Argentina. Host resistance is the most economical, effective and ecologically sustainable method of controlling the disease. Gene postulation helps to determine leaf rust resistance genes (Lr genes) that may be present in a large group of wheat germplasm. Additionally presence of Lr genes can be determined using associated molecular markers. The objective of this study was to identify Lr genes that condition leaf rust resistance in 66 wheat cultivars from Argentina. Twenty four differential lines with individual known leaf rust resistance genes were tested with 17 different pathotypes of leaf rust collected from Argentina. Leaf rust infection types produced on seedling plants of the 66 local cultivars were compared with the infection types produced by the same pathotypes on Lr differentials to postulate which seedling leaf rust genes were present. Presence of Lr9, Lr10, Lr19, Lr20, Lr21, Lr24, Lr25, Lr26, Lr29, Lr34, Lr35, Lr37, Lr47 and Lr51 was also determined using molecular markers. Eleven different Lr genes were postulated in the material: Lr1, Lr3a, Lr3ka, Lr9, Lr10, Lr16, Lr17, Lr19, Lr24, Lr26, Lr41. Presence of Lr21, Lr25, Lr29, and Lr47 could not be determined with the seventeen pathotypes used in the study because all were avirulent to these genes. Eleven cultivars (16.7 percent) were resistant to all pathotypes used in the study and the remaining 55 (83.3 percent) showed virulent reaction against one or more local pathotypes. Cultivars with seedling resistance gene combinations including Lr16 or single genes Lr47 (detected with molecular marker), Lr19 and Lr41, showed high levels of resistance against all pathotypes or most of them. On the opposite side, cultivars with seedling resistance genes Lr1, Lr3a, Lr3a + Lr24, Lr10, Lr3a + Lr10, Lr3a + Lr10 + Lr24 showed the highest number of virulent reactions against local...

Prevalence of atrophic gastritis in dyspeptic patients in Piedmont. A survey using the GastroPanel test.

BACKGROUND: Chronic atrophic gastritis (CAG) is a precursor of the intestinal type of gastric cancer, the second leading cause of cancer-related death worldwide. GastroPanel is a recently marketed serological kit for the non-invasive diagnosis of CAG, defined by some authors "even more reliable than biopsy histology". The goal of this study was 1) to evaluate the agreement between the serum gastric profile provided by GastroPanel (PGI, PGII, G-17, AbHp) and histology over CAG diagnosis, and 2) to evaluate the prevalence of CAG by means of GastroPanel in a Northern Italian dyspeptic population. METHODS: Basal blood samples for GastroPanel parameters evaluation (Biohit Plc, Finland) were collected after an overnight fast from 1387 dyspeptic patients (age range: 18-80 years; F 704). Gastroscopy with two biopsies each of the antrum and corpus was offered to a group of the first 400 consecutive patients (age 18-80 years, F 214) to compare the results of histology and GastroPanel in CAG. RESULTS: Agreement between GastroPanel and histology for corpus-prevalent CAG was 94%, with a sensitivity and specificity of 80% and 96%, respectively. In our series of 1387 dyspeptic patients, the prevalence of corpus-prevalent CAG, of antral-prevalent CAG and of multifocal CAG (antrum+ corpus) was 10.7%, 3.6% and 2.4%, respectively. Out of the 34 patients with multifocal atrophic gastritis, 12% were under 30 years of age. CONCLUSIONS: GastroPanel is a reliable non-invasive test for diagnosis of CAG and deserves consideration for current use in clinical practice as a valuable diagnostic tool.

Increased incidence of small intestinal bacterial overgrowth during proton pump inhibitor therapy.

BACKGROUND & AIMS: Proton pump inhibitors (PPIs) can cause diarrhea, enteric infections, and alter the gastrointestinal bacterial population by suppressing the gastric acid barrier. Among patients that received long term PPI treatment, we evaluated the incidence of small intestinal bacterial overgrowth (SIBO; assessed by glucose hydrogen breath test [GHBT]), the risk factors for development of PPI-related SIBO and its clinical manifestations, and the eradication rate of SIBO after treatment with rifaximin. METHODS: GHBTs were given to 450 consecutive patients (200 with gastroesophageal reflux disease who received PPIs for a median of 36 months; 200 with irritable bowel syndrome [IBS], in absence of PPI treatment for at least 3 years; and 50 healthy control subjects that had not received PPI for at least 10 years). Each subject was given a symptoms questionnaire. RESULTS: SIBO was detected in 50% of patients using PPIs, 24.5% of patients with IBS, and 6% of healthy control subjects; there was a statistically significant difference between patients using PPIs and those with IBS or healthy control subjects (P < .001). The prevalence of SIBO increased after 1 year of treatment with PPI. The eradication rate of SIBO was 87% in the PPI group and 91% in the IBS group. CONCLUSIONS: SIBO, assessed by GHBT, occurs significantly more frequently among long term PPI users than patients with IBS or control subjects. High dose therapy with rifaximin eradicated 87%-91% of cases of SIBO in patients who continued PPI therapy.

Exocrine pancreatic cancer, cigarette smoking, and diabetes mellitus: a case-control study in northern Italy.

The role of cigarette smoking and diabetes mellitus as risk factors for exocrine pancreatic cancer (PC) was investigated in a hospital based case-control study. Current smokers were at increased risk for PC (OR = 2.36, 95% CI 1.53-3.63): the magnitude of the risk was related to the lifetime amount of smoking (chi2(trend) = 17.00; P < 0.0001). Among former smokers, after 15 years from ceasing smoking, the risk for PC dropped to the level of a lifetime non-smoker, whichever the lifetime smoking amount. Diabetes was associated with a 2.89-fold increased risk for PC (95% CI 1.71-4.86): the risk was 4.76 (95% CI 1.99-11.53) for diabetes diagnosed up to 2 years before the diagnosis of PC and dropped to 2.07 (95% CI 1.02-4.20) for diabetes diagnosed more than 5 years before PC. The risk for PC was estimated according to the treatment used to control diabetes: it was 6.49 (95% CI 2.28-18.48) for insulin treated diabetes and 2.12 (95% CI 1.16-3.87) for diabetes treated with oral hypoglycemic drugs. The risk of PC for diabetes treated for more than 5 years before the diagnosis of PC was 6.21 (95% CI 1.61-23.96) for patients treated with insulin and 1.21 (95% CI 0.50-2.92) for those treated with oral hypoglycemic drugs: the type of treatment needed to control the disease may discriminate between the diabetes that represents a consequence of cancer from the diabetes that could represent an etiological co-factor. More studies are needed to clarify whether long-lasting insulin-treated diabetes is an etiological co-factor in PC.

Helicobacter pylori infection and gastric function in primary autonomic neuropathy.

Helicobacter pylori (Hp) infection in diabetic patients has been related to impaired gastric clearance of bacteria due to autonomic neuropathy. Gastrointestinal dysfunction has been described in primary autonomic failure (AF). The aim of the study was to evaluate, for the first time, the presence of Hp infection and gastric function in patients with primary AF Twelve patients with primary AF (aged 58-78), 31 healthy controls (aged 48-75) and 31 patients affected by type 2 diabetes (aged 46-75) were studied. A 13C-urea breath test was performed to assess the presence of Hp infection. To evaluate gastric function, AF patients underwent two non-invasive tests: 1) 13C-octanoic acid breath test (OBT) to evaluate gastric emptying, and 2) electrogastrogram (EGG) to evaluate gastric electrical activity. Hp infection was found in 100% of AF patients, in 48% of controls and in 71% of diabetic patients (p = 0.02 between groups). Electrical or mechanical gastric function was altered in 50% of AF patients. In particular, 1) after OBT, half-time gastric emptying was delayed in 6 out of 12 patients, and 2) EGG showed the presence of gastric dysrhythmias in 6 out of 12 patients. In conclusion, Hp infection was detected in all AF patients studied; as previously demonstrated in diabetes, such a finding might be related to autonomic neuropathy causing mechanical or electrical gastric dysfunction. Hp detection might be important for the gastrointestinal and extradigestive complications of such infection.