Nodal-dependent Cripto signaling promotes cardiomyogenesis and redirects the neural fate of embryonic stem cells

The molecular mechanisms controlling inductive events leading to the specification and terminal differentiation of cardiomyocytes are still largely unknown. We have investigated the role of Cripto, an EGF-CFC factor, in the earliest stages of cardiomyogenesis. We find that both the timing of initiation and the duration of Cripto signaling are crucial for priming differentiation of embryonic stem (ES) cells into cardiomyocytes, indicating that Cripto acts early to determine the cardiac fate. Furthermore, we show that failure to activate Cripto signaling in this early window of time results in a direct conversion of ES cells into a neural fate. Moreover, the induction of Cripto activates the Smad2 pathway, and overexpression of activated forms of type I receptor ActRIB compensates for the lack of Cripto signaling in promoting cardiomyogenesis. Finally, we show that Nodal antagonists inhibit Cripto-regulated cardiomyocyte induction and differentiation in ES cells. All together our findings provide evidence for a novel role of the Nodal/Cripto/Alk4 pathway in this process.     

Accuracy and consistency in application of a probabilistic approach to reporting breast fine needle aspiration

OBJECTIVE: To determine the application of a probabilistic/categorical approach for reporting breast fine needle aspiration (FNA) and its dependence on the cytopathologist's level of experience. STUDY DESIGN: All breast surgical specimens that had preoperative breast FNA at our institution during a 3-year period were identified. The cytologic results were reported as 1 of 6 categories: positive, suspicious, atypical, epithelial proliferative, unremarkable and nondiagnostic, according to well-defined criteria. Five cytopathologists were responsible for all cytology sing-out during the study period. The histologic and cytologic diagnoses were correlated. RESULTS: A total of 297 cases were identified. Overall, there were no false positive cases (positive predictive value [PPV] = 100%). Two false negative cases (negative predictive value [NPV] = 96%) were due to sampling error. This indicates that the PPV and NPV for each of the 5 pathologists were also all 100% except for the 1 pathologist who had two false negative cases due to sampling errors. The probability of finding carcinoma on histology for suspicious and atypical cytologic categories ranged from 67% to 100% and 8% to 31%, respectively, for the individual pathologists. Fifteen cases were signed out by > or = 2 pathologists. The involvement of consultants was significantly associated with diagnosis (P = .02). Ten of the 15 cases were in the suspicious (5) or atypical (5) category. CONCLUSION: The probabilistic approach with defined diagnostic criteria is an accurate method and can be consistently applied in reporting breast FNA. Although use of the indeterminate (suspicious and atypical) categories is variable, a definite and considerable difference in the probability of carcinoma between these 2 categories was observed for all pathologists. The involvement of consultants did not move the cases out of these indeterminate categories.     

Transfer of microorganisms,including Listeria monocytogenes,from various materials to beef

The quantity of microorganisms that may be transferred to a food that comes into contact with a contaminated surface depends on the density of microorganisms on the surface and on the attachment strengths of the microorganisms on the materials. We made repeated contacts between pieces of meat and various surfaces (stainless steel and conveyor belt materials [polyvinyl chloride and polyurethane]), which were conditioned with meat exudate and then were contaminated with Listeria monocytogenes, Staphylococcus sciuri, Pseudomonas putida, or Comamonas sp. Attachment strengths were assessed by the slopes of the two-phase curves obtained by plotting the logarithm of the number of microorganisms transferred against the order number of the contact. These curves were also used to estimate the microbial population on the surface by using the equation of A. Veulemans, E. Jacqmain, and D. Jacqmain (Rev. Ferment. Ind. Aliment. 25:58-65, 1970). The biofilms were characterized according to their physicochemical surface properties and structures. Their exopolysaccharide-producing capacities were assessed from biofilms grown on polystyrene. The L. monocytogenes biofilms attached more strongly to polymers than did the other strains, and attachment strength proved to be weaker on stainless steel than on the two polymers. However, in most cases, it was the population of the biofilms that had the strongest influence on the total number of CFU detached. Although attachment strengths were weaker on stainless steel, this material, carrying a smaller population of bacteria, had a weaker contaminating capacity. In most cases the equation of Veulemans et al. revealed more bacteria than did swabbing the biofilms, and it provided a better assessment of the contaminating potential of the polymeric materials studied here.     

Selective modifications in the nucleus accumbens of dopamine synaptic transmission in rats exposed to chronic stress

Stressful events are accompanied by modifications in dopaminergic transmission in distinct brain regions. As the activity of the neuronal dopamine (DA) transporter (DAT) is considered to be a critical mechanism for determining the extent of DA receptor activation, we investigated whether a 3-week exposure to unavoidable stress, which produces a reduction in DA output in the nucleus accumbens shell (NAcS) and medial prefrontal cortex (mPFC), would affect DAT density and DA D1 receptor complex activity in the NAcS, mPFC and caudate-putamen (CPu). Rats exposed to unavoidable stress showed a decreased DA output in the NAcS accompanied by a decrease in the number of DAT binding sites, and an increase in the number of DA D1 binding sites and Vmax of SKF 38393-stimulated adenylyl cyclase. In the mPFC, stress exposure produced a decrease in DA output with no modification in DAT binding or in DA D1 receptor complex activity. Moreover, in the CPu stress exposure induced no changes in DA output or in the other neurochemical variables examined. This study shows that exposure to a chronic unavoidable stress that produces a decrease in DA output in frontomesolimbic areas induced several adaptive neurochemical modifications selectively in the nucleus accumbens.     

Enhanced activity of the plasma membrane oxidoreductase in circulating lymphocytes from insulin-dependent diabetes mellitus patients

Circulating human lymphocytes contain a transmembrane oxidoreductase (PMOR) capable of reducing dichlorophenol indophenol (DCIP) by endogenous reductants, presumably NADH. Membranes from lymphocytes obtained from buffy coats contain a NADH DCIP reductase having a K(m) of about 1 microM and almost insensible to dicoumarol. The PMOR of lymphocytes from insulin-dependent diabetic patients is higher than that from age-matched controls and, in addition, has a dicoumarol-sensitive component, lacking in most controls, presumably due to membrane association of DT-diaphorase. The increase of PMOR in diabetes is likely due to overexpression of the enzyme, in view of the very low K(m) for NADH indicating that, in intact cells, the enzyme is practically saturated with the reductant substrate.     

Glutamate synthesis in barley roots: the role of the plastidic glucose-6-phosphate dehydrogenase

Evidence is provided for a close link between glutamate (Glu) synthesis and the production of reducing power by the oxidative pentose phosphate pathway (OPPP) in barley ( Hordeum vulgare L. var. Alfeo) root plastids. A rapid procedure for isolating organelles gave yields of plastids of over 30%, 60% of which were intact. The formation of Glu by intact plastids fed with glutamine and 2-oxoglutarate, both substrates of glutamate synthase (GOGAT), depends on glucose-6-phosphate (Glc-6-P) supply. The whole process exhibited an apparent K(m Glc-6-P) of 0.45 mM and is abolished by azaserine, a specific inhibitor of GOGAT; ATP caused a decrease in the rate of Glu formation. Glucose and other sugar phosphates were not as effective in supporting Glu synthesis with respect to Glc-6-P; only ribose-5-phosphate, an intermediate of OPPP, supported rates equivalent to Glc-6-P. Glucose-6-phosphate dehydrogenase (Glc6PDH) rapidly purified from root plastids showed an apparent K(m Glc-6-P) of 0.96 mM and an apparent K(m NADP)(+) of 9 micro M. The enzyme demonstrated high tolerance to NADPH, exhibiting a K(i) (NADPH) of 58.6 micro M and selectively reacted with antibodies against potato plastidic, but not chloroplastic, Glc6PDH isoform. The data support the hypothesis that plastidic OPPP is the main site of reducing power supply for GOGAT within the plastids, and suggest that the plastidic OPPP would be able to sustain Glu synthesis under high NADPH:NADP(+) ratios even if the plastidic Glc6PDH may not be functioning at its highest rates.     

A Modular Flat Panel Photobioreactor (MFPP) for indoor mass cultivation of Nannochloropsis sp. under artificial illumination

Nannochloropsis sp. was grown in a Modular FlatPanel Photobioreactor (MFPP) consisting of sixalveolar panels each with 20.5 L culture volume and3.4 m² illuminated surface area. The panelsformed a closely-packed unit with illuminationprovided by banks of fluorescent tubes placed betweenthe panels. The whole unit was contained in athermoregulated cabinet. Continuous illumination ofone side of the panels with 115 molphoton m^-2 s^-1 attained a mean volumetricproductivity of 0.61 g (d. wt) L^-1 24 h^-1,increasing to 0.97 g (d. wt) L^-1 24 h^-1 whenthe same irradiance was provided on both sides of thepanels. With 230 mol photon m^-2 s^-1 onone side of the panel, a mean productivity of 0.85 g(d. wt) L^-1 24 h^-1 was achieved, whichreached 1.45 g (d. wt) L^-1 24 h^-1 when bothsides were illuminated. Increasing the amount of lightprovided to the culture (either by increasingirradiance or the illuminated surface area) decreasedpigment and enhanced the total fatty acid content, butdid not change significantly the content ofeicosapentaenoic acid. A MFPP of the presentdimensions could produce sufficient microalgae tosupport a hatchery producing 6 million sea breamfingerlings annually.     

TNFA Haplotype Genetic Testing Improves HLA in Estimating the Risk of Celiac Disease in Children

Background

TNF-α and IFN-γ play a role in the development of mucosal damage in celiac disease (CD). Polymorphisms of TNFA and IFNG genes, as well as of the TNFRSF1A gene, encoding the TNF-α receptor 1, might underlie different inter-individual disease susceptibility over a common HLA risk background. The aims of this study were to ascertain whether five SNPs in the TNFA promoter (-1031T>C,-857C>T,-376G>A,-308G>A,-238G>A), sequence variants of the TNFRSF1A gene and IFNG +874A>T polymorphism are associated with CD in a HLA independent manner.

Methods

511 children (244 CD, 267 controls) were genotyped for HLA, TNFA and INFG (Real Time PCR). TNFRSF1A variants were studied (DHPLC and sequence).

Results

Only the rare TNFA-1031C (OR=0.65, 95% CI:0.44-0.95), -857T (OR=0.42, 95% CI:0.27-0.65), -376A (OR=2.25, 95% CI:1.12-4.51) and -308A (OR=4.76, 95% CI:3.12-7.26) alleles were significantly associated with CD. One TNFRSF1A variant was identified (c.625+10A>G, rs1800693), but not associated with CD. The CD-correlated TNFA SNPs resulted in six haplotypes. Two haplotypes were control-associated (CCGG and TTGG) and three were CD-associated (CCAG, TCGA and CCGA). The seventeen inferred haplotype combinations were grouped (A to E) based on their frequencies among CD. Binary logistic regression analysis documented a strong association between CD and HLA (OR for intermediate risk haplotypes=178; 95% CI:24-1317; OR for high risk haplotypes=2752; 95% CI:287-26387), but also an HLA-independent correlation between CD and TNFA haplotype combination groups. The CD risk for patients carrying an intermediate risk HLA haplotype could be sub-stratified by TNFA haplotype combinations.

Conclusion

TNFA promoter haplotypes associate with CD independently from HLA. We suggest that their evaluation might enhance the accuracy in estimating the CD genetic risk.     

Dietary Total Antioxidant Capacity and Colorectal Cancer in the Italian EPIC Cohort

Background

Colorectal cancer is the third most common cancer worldwide. Diet has been hypothesized as involved in colorectal cancer etiology, but few studies on the influence of total dietary antioxidant intake on colorectal cancer risk have been performed.

Methods

We investigated the association between colorectal cancer risk and the total antioxidant capacity (TAC) of the diet, and also of intake of selected antioxidants, in 45,194 persons enrolled in 5 centers (Florence, Naples, Ragusa, Turin and Varese) of the European Prospective Investigation into Cancer and Nutrition (EPIC) Italy study. TAC was estimated by the Trolox equivalent antioxidant capacity (TEAC) assay. Hazard ratios (HRs) for developing colorectal cancer, and colon and rectal cancers separately, adjusted for confounders, were estimated for tertiles of TAC by Cox modeling, stratifying by center.

Results

Four hundred thirty-six colorectal cancers were diagnosed over a mean follow-up of 11.28 years. No significant association between dietary TAC and colorectal cancer incidence was found. However for the highest category of TAC compared to the lowest, risk of developing colon cancer was lower (HR: 0.63; 95% CI: 0.44–0.89, P trend: 0.008). By contrast, increasing TAC intake was associated with significantly increasing risks of rectal cancer (2nd tertile HR: 2.09; 95%CI: 1.19–3.66; 3rd tertile 2.48 95%CI: 1.32–4.66; P trend 0.007). Intakes of vitamin C, vitamin E, and ß-carotene were not significantly associated with colorectal cancer risk.

Conclusions

Further prospective studies are needed to confirm the contrasting effects of high total antioxidant intake on risk of colon and rectal cancers.     

Between Andes and Amazon: The genetic profile of the Arawak‐speaking Yanesha

The Yanesha are a Peruvian population who inhabit an environment transitional between the Andes and Amazonia. They present cultural traits characteristic of both regions, including in the language they speak: Yanesha belongs to the Arawak language family (which very likely originated in the Amazon/Orinoco lowlands), but has been strongly influenced by Quechua, the most widespread language family of the Andes. Given their location and cultural make‐up, the Yanesha make for an ideal case study for investigating language and population dynamics across the Andes‐Amazonia divide. In this study, we analyze data from high and mid‐altitude Yanesha villages, both Y chromosome (17 STRs and 16 SNPs diagnostic for assigning haplogroups) and mtDNA data (control region sequences and 3 SNPs and one INDEL diagnostic for assigning haplogroups). We uncover sex‐biased genetic trends that probably arose in different stages: first, a male‐biased gene flow from Andean regions, genetically consistent with highland Quechua‐speakers and probably dating back to Inca expansion; and second, traces of European contact consistent with Y chromosome lineages from Italy and Tyrol, in line with historically documented migrations. Most research in the history, archaeology and linguistics of South America has long been characterized by perceptions of a sharp divide between the Andes and Amazonia; our results serve as a clear case‐study confirming demographic flows across that ‘divide’. Am J Phys Anthropol 155:600–609, 2014. © 2014 The Authors. American journal of physical Anthropology published by Wiley Periodocals, Inc.