28 research outputs found
Dorsoventral Patterning of the Mouse Coat by Tbx15
Many members of the animal kingdom display coat or skin color differences along their dorsoventral axis. To determine the mechanisms that control regional differences in pigmentation, we have studied how a classical mouse mutation, droopy ear (de(H)), affects dorsoventral skin characteristics, especially those under control of the Agouti gene. Mice carrying the Agouti allele black-and-tan (a(t)) normally have a sharp boundary between dorsal black hair and yellow ventral hair; the de(H) mutation raises the pigmentation boundary, producing an apparent dorsal-to-ventral transformation. We identify a 216 kb deletion in de(H) that removes all but the first exon of the Tbx15 gene, whose embryonic expression in developing mesenchyme correlates with pigmentary and skeletal malformations observed in de(H)/de(H) animals. Construction of a targeted allele of Tbx15 confirmed that the de(H) phenotype was caused by Tbx15 loss of function. Early embryonic expression of Tbx15 in dorsal mesenchyme is complementary to Agouti expression in ventral mesenchyme; in the absence of Tbx15, expression of Agouti in both embryos and postnatal animals is displaced dorsally. Transplantation experiments demonstrate that positional identity of the skin with regard to dorsoventral pigmentation differences is acquired by E12.5, which is shortly after early embryonic expression of Tbx15. Fate-mapping studies show that the dorsoventral pigmentation boundary is not in register with a previously identified dermal cell lineage boundary, but rather with the limb dorsoventral boundary. Embryonic expression of Tbx15 in dorsolateral mesenchyme provides an instructional cue required to establish the future positional identity of dorsal dermis. These findings represent a novel role for T-box gene action in embryonic development, identify a previously unappreciated aspect of dorsoventral patterning that is widely represented in furred mammals, and provide insight into the mechanisms that underlie region-specific differences in body morphology
Measurement of the Ratio of b Quark Production Cross Sections in Antiproton-Proton Collisions at 630 GeV and 1800 GeV
We report a measurement of the ratio of the bottom quark production cross
section in antiproton-proton collisions at 630 GeV to 1800 GeV using bottom
quarks with transverse momenta greater than 10.75 GeV identified through their
semileptonic decays and long lifetimes. The measured ratio
sigma(630)/sigma(1800) = 0.171 +/- .024 +/- .012 is in good agreement with
next-to-leading order (NLO) quantum chromodynamics (QCD)
A fish protein hydrolysate alters fatty acid composition in liver and adipose tissue and increases plasma carnitine levels in a mouse model of chronic inflammation
Background: There is growing evidence that fish protein hydrolysate (FPH) diets affect mitochondrial fatty acid metabolism in animals. The aim of the study was to determine if FPH could influence fatty acid metabolism and inflammation in transgene mice expressing human tumor necrosis factor alpha (hTNFα). Methods: hTNFα mice (C57BL/6 hTNFα) were given a high-fat (23%, w/w) diet containing 20% casein (control group) or 15% FPH and 5% casein (FPH group) for two weeks. After an overnight fast, blood, adipose tissue, and liver samples were collected. Gene expression and enzyme activity was analysed in liver, fatty acid composition was analyzed in liver and ovarian white adipose tissue, and inflammatory parameters, carnitine, and acylcarnitines were analyzed in plasma. Results: The n-3/n-6 fatty acid ratio was higher in mice fed the FPH diet than in mice fed the control diet in both adipose tissue and liver, and the FPH diet affected the gene expression of Δ6 and Δ9 desaturases. Mice fed this diet also demonstrated lower hepatic activity of fatty acid synthase. Concomitantly, a lower plasma INF-γ level was observed. Plasma carnitine and the carnitine precursor γ-butyrobetaine was higher in the FPH-group compared to control, as was plasma short-chained and medium-chained acylcarnitine esters. The higher level of plasma acetylcarnitine may reflect a stimulated mitochondrial and peroxisomal β-oxidation of fatty acids, as the hepatic activities of peroxisomal acyl-CoA oxidase 1 and mitochondrial carnitine palmitoyltransferase-II were higher in the FPH-fed mice. Conclusions: The FPH diet was shown to influence hepatic fatty acid metabolism and fatty acid composition. This indicates that effects on fatty acid metabolism are important for the bioactivity of protein hydrolysates of marine origin
Long-term treatment with the pan-PPAR agonist tetradecylthioacetic acid or fish oil is associated with increased cardiac content of n-3 fatty acids in rat
Background: Excess peroxisome proliferator-activated receptor (PPAR) stimulation has been associated with detrimental health effects including impaired myocardial function. Recently, supplementation with n-3 polyunsaturated fatty acids (PUFA) has been associated with improved left ventricular function and functional capacity in patients with dilated cardiomyopathy. We investigated the long-term effects of the pan-PPAR agonist tetradecylthioacetic acid (TTA) and/or high-dose fish oil (FO) on cardiac fatty acid (FA) composition and lipid metabolism. Male Wistar rats were given one out of four different 25% (w/v) fat diets: control diet; TTA diet; FO diet; or diet containing both TTA and FO. Results: After 50 weeks n-3 PUFA levels were increased by TTA and FO in the heart, whereas liver levels were reduced following TTA administration. TTA was associated with a decrease in arachidonic acid, increased activities of carnitine palmitoyltransferase II, fatty acyl-CoA oxidase, glycerol-3-phosphate acyltransferase, and fatty acid synthase in the heart. Furthermore, cardiac Ucp3 and Cact mRNA was upregulated. Conclusions: Long-term treatment with the pan-PPAR agonist TTA or high-dose FO induced marked changes in PUFA composition and enzymatic activity involved in FA metabolism in the heart, different from liver. Changes included increased FA oxidation and a selective increase in cardiac n-3 PUFA
Use of loop diuretics is associated with increased mortality in patients with suspected coronary artery disease, but without systolic heart failure or renal impairment: an observational study using propensity score matching
Background Loop diuretics are widely used in patients with heart and renal failure, as well as to treat hypertension and peripheral edema. However, there are no randomized, controlled trials (RCT) evaluating their long term safety, and several observational reports have indicated adverse effects. We sought to evaluate the impact of loop diuretics on long term survival in patients with suspected coronary artery disease, but without clinical heart failure, reduced left ventricular ejection fraction or impaired renal function. Method and Findings From 3101 patients undergoing coronary angiography for suspected stable angina pectoris, subjects taking loop diuretics (n=109) were matched with controls (n=198) in an attempted 1:2 ratio, using propensity scores based on 59 baseline variables. During median follow-up of 10.1 years, 37.6% in the loop diuretics group and 23.7% in the control group died (log-rank p-value 0.005). Treatment with loop diuretics was associated with a hazard ratio (95% confidence interval) of 1.82 (1.20, 2.76), and the number needed to harm was 7.2 (4.1, 30.3). Inclusion of all 3101 patients using propensity score weighting and adjustment for numerous covariates provided similar estimates. The main limitation is the potential of confounding from unmeasured patient characteristics. Conclusions The use of loop diuretics in patients with suspected coronary artery disease, but without systolic heart failure or renal impairment, is associated with increased risk of all-cause mortality. Considering the lack of randomized controlled trials to evaluate long term safety of loop diuretics, our data suggest caution when prescribing these drugs to patients without a clear indication
Loss of statin treatment years during pregnancy and breastfeeding periods in women with familial hypercholesterolemia
Background and aims Women with heterozygous familial hypercholesterolemia (FH) are recommended to initiate statin treatment at the same age as men (from 8 to 10 years of age). However, statins are contraindicated when pregnancy is planned, during pregnancy and breastfeeding. The aim of the study was to determine the duration of pregnancy-related off-statin periods and breastfeeding in FH women. Methods A cross-sectional study using an anonymous online self-administered questionnaire was conducted. Women with FH were recruited through Lipid Clinics in Norway and Netherlands and national FH patient organizations. Results 102 women with FH (n = 70 Norwegian and n = 32 Dutch) were included in the analysis. Total length of pregnancy-related off-statin periods was estimated for 80 women where data were available, and was median (min-max) 2.3 (0–14.2) years. Lost statin treatment time was estimated for 67 women where data were available, and was median (min-max) 18 (0–100)% at mean (SD) age of 31 (4.3) years at last pregnancy. More women breastfed in Norway (83%) and for longer time [8.5 [1-42] months] compared to the Netherlands [63%, p = 0.03; 3.6 (0–14) months, p < 0.001]. Eighty-six percent of the women reported need for more information on pregnancy and breastfeeding in relation to FH. Conclusions Young FH women lose years of treatment when discontinuing statins in relation to pregnancy and breastfeeding periods and should be closely followed up to minimize the duration of these off-statin periods. Whether these periods of interrupted treatment increase the cardiovascular risk in FH women needs to be further elucidated
Public Investment in University Distance Learning Programs: Some Performance-Based Evidence
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Long-term treatment with the pan-PPAR agonist tetradecylthioacetic acid or fish oil is associated with increased cardiac content of n-3 fatty acids in rat
Diagnostic accuracy of transabdominal ultrasound in detecting prenatal cleft lip and palate: a systematic review.
Item does not contain fulltextOBJECTIVES: To systematically review the diagnostic accuracy of second-trimester transabdominal ultrasound in detecting orofacial clefts in low- and high-risk populations and to compare two-dimensional (2D) with three-dimensional (3D) ultrasound techniques. METHODS: MEDLINE and EMBASE were searched for articles published in English, Dutch, French or German using the keywords 'cleft' and 'ultrasound' or 'screening' or 'sonogram' and 'prenatal' or 'antenatal' or 'fetus' to identify cohort studies and randomized trials in order to assess the detection rate by prenatal ultrasound of cleft lip and palate in high-risk and low-risk pregnant women. RESULTS: Of 451 citations identified, 27 met the criteria for the systematic review, 21 involving unselected low-risk populations and six involving high-risk populations. In the selected studies there was diversity in the gestational age at which the ultrasound examination was performed and there was considerable variety in the diagnostic accuracy of 2D ultrasound in the low-risk women, with prenatal detection rates ranging from 9% to 100% for cleft lip with or without cleft palate, 0% to 22% for cleft palate only and 0% to 73% for all types of cleft. 3D ultrasound in high-risk women resulted in a detection rate of 100% for cleft lip, 86% to 90% for cleft lip with palate and 0% to 89% for cleft palate only. CONCLUSIONS: 2D ultrasound screening for cleft lip and palate in a low-risk population has a relatively low detection rate but is associated with few false-positive results. 3D ultrasound can achieve a reliable diagnosis, but not of cleft palate only.1 april 201