| 5081. |
- Petrini, Johan, et al.
(författare)
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Circumferential strain by velocity vector imaging and speckle-tracking echocardiography : validation against sonomicrometry in an aortic phantom
- 2018
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Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 38:2, s. 269-277
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Tidskriftsartikel (refereegranskat)abstract
- Background: Evaluation of arterial deformation and mechanics using strain analysis on ultrasound greyscale images has gained increasing scientific interest. The aim of this study was to validate in vitro measurements of circumferential strain by velocity vector imaging (VVI) and speckle-tracking echocardiography (STE) against sonomicrometry as a reference method. Method: Two polyvinyl alcohol phantoms sized to mimic the descending aorta were constructed and connected to a pulsatile flow pump to obtain high-resistance flow profiles. The ultrasound images of the phantom used for strain analyses were acquired with a transesophageal probe. Global and regional circumferential strains were estimated using VVI and STE and were compared with the strain acquired by sonomicrometry. Results: Global circumferential peak strain estimated by VVI and STE correlated well to sonomicrometry (r = 0·90, P≤0·001; and r = 0·97, P≤0·01) with a systematic bias of −0·78% and +0·63%, respectively. The reference strain levels were 1·07–2·54%. Circumferential strain values obtained by VVI were significantly lower than those obtained by STE (bias −1·41%, P≤0·001). Conclusion: Global circumferential strain measured by VVI and STE correlates well with sonomicrometry. However, strain values obtained by VVI and STE differ significantly, which should be taken into consideration when comparing results from studies using different software for aortic strain measurements.
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| 5082. |
- Petter, Hedelin, et al.
(författare)
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Measurement of cardiac output with non-invasive Aesculon impedance versus thermodilution.
- 2011
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961. ; 31:1, s. 39-47
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Tidskriftsartikel (refereegranskat)abstract
- This study compared the non-invasive thoracic electrical bioimpedance Aesculon technique (TEB(Aesculon) ) with thermodilution (TD) to evaluate whether TEB(Aesculon) may offer a reliable means for estimating cardiac output (CO) in humans.
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| 5083. |
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| 5084. |
- Pettersson, Ulrika, et al.
(författare)
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Female Mice are Protected against High-Fat Diet Induced Metabolic Syndrome and Increase the Regulatory T Cell Population in Adipose Tissue
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:9, s. e46057-
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Tidskriftsartikel (refereegranskat)abstract
- Sex differences in obesity-induced complications such as type 2 diabetes have been reported. The aim of the study was to pinpoint the mechanisms resulting in different outcome of female and male mice on a high-fat diet (HFD). Mice fed control or HFD were monitored for weight, blood glucose, and insulin for 14 weeks. Circulating chemokines, islet endocrine function and blood flow, as well as adipose tissue populations of macrophages and regulatory T-lymphocytes (T-reg) were thereafter assessed. Despite similar weight (43.8 +/- 1.0 and 40.2 +/- 1.5 g, respectively), male but not female mice developed hyperinsulinemia on HFD as previously described (2.5 +/- 0.7 and 0.5 +/- 0.1 pmol/l, respectively) consistent with glucose intolerance. Male mice also exhibited hypertrophic islets with intact function in terms of insulin release and blood perfusion. Low-grade, systemic inflammation was absent in obese female but present in obese male mice (IL-6 and mKC, males: 77.4 +/- 17 and 1795 +/- 563; females: 14.6 +/- 4.9 and 240 +/- 22 pg/ml), and the population of inflammatory macrophages was increased in intra-abdominal adipose tissues of high-fat-fed male but not female mice. In contrast, the anti-inflammatory T-reg cell population increased in the adipose tissue of female mice in response to weight gain, while the number decreased in high-fat-fed male mice. In conclusion, female mice are protected against HFD-induced metabolic changes while maintaining an anti-inflammatory environment in the intra-abdominal adipose tissue with expanded T-reg cell population, whereas HFD-fed male mice develop adipose tissue inflammation, glucose intolerance, hyperinsulinemia, and islet hypertrophy.
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| 5085. |
- Pettersson, Ulrika, et al.
(författare)
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Two-week treatment with the β3-adrenoceptor antagonist SR59230A normalizes the increased pancreatic islet blood flow in type 2 diabetic GK rats
- 2012
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Ingår i: Diabetes, obesity and metabolism. - : Wiley. - 1462-8902 .- 1463-1326. ; 14:10, s. 960-962
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Tidskriftsartikel (refereegranskat)abstract
- The Goto-Kakizaki (GK) rat, a type 2 diabetes model, has increased pancreatic islet and white adipose tissue (WAT) blood flow, and this can be normalized by acute administration of SR59230A, a beta(3)-adrenoceptor antagonist. We now implanted osmotic pumps which allowed a constant release of saline or SR59230A (0.6 mg/kg x day) for 2 weeks. A decrease in islet blood flow was seen also after 2 weeks of continuous SR59230A treatment in the GK rat. However, no improvement in glucose tolerance was seen in the GK rats. Neither did SR59230A affect insulin secretion from isolated islets in vitro. WAT blood flow was not affected by the 2-week SR59230A treatment. Thus, the increased islet blood flow seen in the GK rat can be normalized for up to 2 weeks, which opens the possibilities for further studies on the long-term functional role on the islet blood flow increase in this type 2 diabetes model.
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| 5086. |
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| 5087. |
- Phillipson, Mia, et al.
(författare)
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Inducible nitric oxide synthase is involved in acid-induced gastric hyperemia in rats and mice
- 2003
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Ingår i: American Journal of Physiology - Gastrointestinal and Liver Physiology. - : American Physiological Society. - 0193-1857 .- 1522-1547. ; 285:1, s. G154-G162
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Tidskriftsartikel (refereegranskat)abstract
- The role of different isoforms of nitric oxide synthase (NOS) in the gastric mucosal hyperemia, induced by 155 mM luminal hydrochloric acid (pH approximately 0.8) without a barrier breaker, was investigated. Rats were anesthetized with Inactin (120 mg/kg ip), and mice were anesthetized with Forene (2.2% in 40% oxygen gas at 150 ml/min); the gastric mucosa was exteriorized. Gastric mucosal blood flow was measured with laser-Doppler flowmetry (LDF) in rats treated with Nomega-nitro-l-arginine (l-NNA; unspecific NOS inhibitor), l-N6-(1-iminoethyl)lysine [l-NIL; inducible (i) NOS inhibitor], or S-methyl-l-thiocitrulline [SMTC; neuronal (n) NOS inhibitor], 10 mg/kg, followed by 3 mg. kg-1. h-1 iv, in iNOS-deficient (-/-) and nNOS(-/-) mice. mRNA was isolated from the gastric mucosa in iNOS(-/-) and wild-type (wt) mice, and real-time RT-PCR was performed. The effect of 155 mM acid on gastric mucosal permeability was determined by measuring the clearance of 51Cr-EDTA from blood to lumen. LDF increased by 48 +/- 13% during 155 mM HCl luminally, an increase that was abolished by l-NNA, SMTC, or l-NIL. In iNOS wt mice, LDF increased by 33 +/- 8% during luminal acid. The blood flow increase was attenuated substantially in iNOS(-/-) mice. RT-PCR revealed iNOS mRNA expression in the gastric mucosa in the iNOS wt groups. The blood flow increase in response to acid was not abolished in nNOS(-/-) mice (nNOS-sufficient mice, 39 +/- 18%; heterozygous mice, 25 +/- 19%; -/- mice, 19 +/- 7%). Mucosal permeability was transiently increased during 155 mM HCl. The results suggest that iNOS is constitutively expressed in the gastric mucosa and is involved in acid-induced hyperemia, suggesting a novel role for iNOS in gastric mucosal protection.
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| 5088. |
- Pialoux, V., et al.
(författare)
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Effects of exercise and training in hypoxia on antioxidant/pro-oxidant balance
- 2006
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Ingår i: European Journal of Clinical Nutrition. - London, United Kingdom : Nature Publishing Group. - 0954-3007 .- 1476-5640. ; 60:12, s. 1345-54
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim was to investigate the effects of acute exercise under hypoxic condition and the repetition of such exercise in a 'living low-training high' training on the antioxidant/prooxidant balance.Design: Randomized, repeated measures design.Setting: Faculté de Médecine, Clermont-Ferrand, France.Subjects: Fourteen runners were randomly divided into two groups. A 6-week endurance training protocol integrated two running sessions per week at the second ventilatory threshold into the usual training.Intervention: A 6-week endurance training protocol integrated two running sessions per week at the second ventilatory threshold into the usual training. The first hypoxic group (HG, n=8) carried out these sessions under hypoxia (3000 m simulated altitude) and the second normoxic group (NG, n=6) in normoxia. In control period, the runners were submitted to two incremental cycling tests performed in normoxia and under hypoxia (simulated altitude of 3000 m). Plasma levels of advanced oxidation protein products (AOPP), malondialdehydes (MDA) and lipid oxidizability, ferric-reducing antioxidant power (FRAP), lipid-soluble antioxidants (alpha-tocopherol and beta-carotene) normalized for triacyglycerols and cholesterol were measured before and after the two incremental tests and at rest before and after training.Results: No significant changes of MDA and AOPP level were observed after normoxic exercise, whereas hypoxic exercise induced a 56% rise of MDA and a 44% rise of AOPP. Plasma level of MDA and arterial oxygen hemoglobin desaturations after the acute both exercises were highly correlated (r=0.73). alpha-Tocopherol normalized for cholesterol and triacyglycerols increased only after hypoxic exercise (10-12%, P<0.01). After training, FRAP resting values (-21%, P<0.05) and alpha-tocopherol/triacyglycerols ratio (-24%, P<0.05) were diminished for HG, whereas NG values remained unchanged.Conclusions: Intense exercise and hypoxia exposure may have a cumulative effect on oxidative stress. As a consequence, the repetition of such exercise characterizing the 'living low-training high' model has weakened the antioxidant capacities of the athletes.Sponsorship: International Olympic Committee and the Direction Régionale de la Jeunesse et des Sports de la Région Auvergne.
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| 5089. |
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| 5090. |
- Pierzynowski, Stefan G., et al.
(författare)
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Experiments suggesting extra-digestive effects of enteral pancreatic amylase and its peptides on glucose homeostasis in a pig model
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- The studies presented were designed to highlight the impact of pancreatic enzymes on glycemic control and insulin response. Blood glucose and plasma insulin levels were monitored after intravenous, oral or direct gut glucose tolerance tests (GTT) in 6 pigs with an intact gastrointestinal tract and in 12 pigs following duodenal-jejunal bypass (DJB) surgery. In the intact pigs, pancreatic enzymes (Creon®) given orally 1 h prior to the GTT, lowered the blood glucose levels during the oral and meal GTT and reduced the plasma insulin response during the intravenous and meal GTT. In DJB pigs, blood glucose and plasma insulin levels were higher following glucose loading into the by-passed biliopancreatic limb as compared to that following glucose loading orally or into the common intestinal limb. Infusion of amylase or amylase peptides together with glucose into the biliopancreatic limb lowered blood glucose levels in DJB pigs. These preliminary data suggest new, extra-digestive, actions of enteral pancreatic enzymes - probably amylase or its peptides - on glucose homeostasis, with an reduction in net glucose absorption into the blood and in insulin response. This ability of digestive enzymes (amylase) to reduce post-prandial hyperglycaemia in an insulin-independent manner could aid in preventing the development of obesity and diabetes.
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