| 1. |
- Madder, Ryan D, et al.
(författare)
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Confirmation of the Intracoronary Near-Infrared Spectroscopy Threshold of Lipid-Rich Plaques That Underlie ST-Segment-Elevation Myocardial Infarction.
- 2016
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - 1524-4636. ; 36:5, s. 1010-1015
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Tidskriftsartikel (refereegranskat)abstract
- In a previous exploratory analysis, intracoronary near-infrared spectroscopy (NIRS) found the majority of culprit lesions in ST-segment-elevation myocardial infarction (STEMI) to contain a maximum lipid core burden index in 4 mm (maxLCBI4mm) of >400. This initial study was limited by a small sample size, enrollment at a single center, and post hoc selection of the maxLCBI4mm ≥400 threshold. This study was designed a priori to substantiate the ability of NIRS to discriminate STEMI culprit from nonculprit segments and to confirm the performance of the maxLCBI4mm ≥400 threshold.
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| 2. |
- Andersson, Lotta, et al.
(författare)
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Characterization of Stimulus-Secretion Coupling in the Human Pancreatic EndoC-βH1 Beta Cell Line.
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:3
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Tidskriftsartikel (refereegranskat)abstract
- Studies on beta cell metabolism are often conducted in rodent beta cell lines due to the lack of stable human beta cell lines. Recently, a human cell line, EndoC-βH1, was generated. Here we investigate stimulus-secretion coupling in this cell line, and compare it with that in the rat beta cell line, INS-1 832/13, and human islets.
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| 3. |
- Fex, Malin, et al.
(författare)
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The pathogenetic role of β-cell mitochondria in type 2 diabetes
- 2018
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Ingår i: Journal of Endocrinology. - 0022-0795. ; 236:3, s. 145-149
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Forskningsöversikt (refereegranskat)abstract
- Mitochondrial metabolism is a major determinant of insulin secretion from pancreatic β-cells. Type 2 diabetes evolves when β-cells fail to release appropriate amounts of insulin in response to glucose. This results in hyperglycemia and metabolic dysregulation. Evidence has recently been mounting that mitochondrial dysfunction plays an important role in these processes. Monogenic dysfunction of mitochondria is a rare condition but causes a type 2 diabetes-like syndrome owing to β-cell failure. Here, we describe novel advances in research on mitochondrial dysfunction in the β-cell in type 2 diabetes, with a focus on human studies. Relevant studies in animal and cell models of the disease are described. Transcriptional and translational regulation in mitochondria are particularly emphasized. The role of metabolic enzymes and pathways and their impact on β-cell function in type 2 diabetes pathophysiology are discussed. The role of genetic variation in mitochondrial function leading to type 2 diabetes is highlighted. We argue that alterations in mitochondria may be a culprit in the pathogenetic processes culminating in type 2 diabetes.
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| 4. |
- Gerencser, Akos A, et al.
(författare)
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Calcium Modulation of Exocytosis-Linked Plasma Membrane Potential Oscillations in INS-1 832/13 Cells.
- 2015
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Ingår i: Biochemical Journal. - 0264-6021. ; 471:1, s. 111-122
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Tidskriftsartikel (refereegranskat)abstract
- In the presence of high glucose or pyruvate, INS-1 832/13 insulinoma cells undergo stochastic oscillations in plasma membrane potential (Δψp) leading to associated fluctuations in cytosolic free Ca(2+) concentration ([Ca(2+)]c). Oscillations are not driven by upstream metabolic fluctuations, but rather by autonomous ionic mechanisms, the details of which are unclear. We have investigated the nature of the oscillator, with simultaneous fluorescence monitoring of Δψp, [Ca(2+)]c and exocytosis at single cell resolution, combined with analysis of the occurrence, frequency and amplitude of Δψp oscillations. Oscillations were closely coupled to exocytosis, indicated by coincident synaptopHluorin fluorescence enhancement. L-type Ca(2+) channel inhibitors enhanced Δψp and [Ca(2+)]c oscillation frequency in the presence of pyruvate, but abolished the sustained [Ca(2+)]c response following KCl-depolarization. The L-type Ca(2+) channel inhibitor isradipine did not inhibit oscillation-linked exocytosis. The T-type Ca(2+) channel inhibitor NNC-55 0396 inhibited Δψp and [Ca(2+)]c oscillations, implying that T-channels trigger oscillations and consequent exocytosis.Since distinct ion channels operate in oscillating and non-oscillating cells, quantitative analysis of Δψp and [Ca(2+)]c oscillations in a β-cell population may help to improve our understanding of the link between metabolism and insulin secretion.
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| 5. |
- Nicholls, David G.
(författare)
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The pancreatic β-cell : A bioenergetic perspective
- 2016
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Ingår i: Physiological Reviews. - : American Physiological Society. - 0031-9333 .- 1522-1210. ; 96:4, s. 1385-1447
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Tidskriftsartikel (refereegranskat)abstract
- The pancreatic β-cell secretes insulin in response to elevated plasma glucose. This review applies an external bioenergetic critique to the central processes of glucose-stimulated insulin secretion, including glycolytic and mitochondrial metabolism, the cytosolic adenine nucleotide pool, and its interaction with plasma membrane ion channels. The control mechanisms responsible for the unique responsiveness of the cell to glucose availability are discussed from bioen-ergetic and metabolic control standpoints. The concept of coupling factor facilitation of secretion is critiqued, and an attempt is made to unravel the bioenergetic basis of the oscillatory mechanisms controlling secretion. The need to consider the physiological constraints operating in the intact cell is emphasized throughout. The aim is to provide a coherent pathway through an extensive, complex, and sometimes bewildering literature, particularly for those unfamiliar with the field.
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| 6. |
- Pitts, Reynaria, et al.
(författare)
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Aldosterone Does Not Predict Cardiovascular Events Following Acute Coronary Syndrome in Patients Initially Without Heart Failure
- 2017
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Ingår i: Journal of the American Heart Association. - : WILEY-BLACKWELL. - 2047-9980. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Background- Aldosterone may have adverse effects in the myocardium and vasculature. Treatment with an aldosterone antagonist reduces cardiovascular risk in patients with acute myocardial infarction complicated by heart failure (HF) and left ventricular systolic dysfunction. However, most patients with acute coronary syndrome do not have advanced HF. Among such patients, it is unknown whether aldosterone predicts cardiovascular risk. Methods and Results- To address this question, we examined data from the dal-OUTCOMES trial that compared the cholesteryl ester transfer protein inhibitor dalcetrapib with placebo, beginning 4 to 12 weeks after an index acute coronary syndrome. Patients with New York Heart Association class II (with LVEF amp;lt; 40%), III, or IV HF were excluded. Aldosterone was measured at randomization in 4073 patients. The primary outcome was a composite of coronary heart disease death, nonfatal myocardial infarction, stroke, hospitalization for unstable angina, or resuscitated cardiac arrest. Hospitalization for HF was a secondary endpoint. Over a median follow-up of 37 months, the primary outcome occurred in 366 patients (9.0%), and hospitalization for HF occurred in 72 patients (1.8%). There was no association between aldosterone and either the time to first occurrence of a primary outcome (hazard ratio for doubling of aldosterone 0.92, 95% confidence interval 0.78-1.09, P=0.34) or hospitalization for HF (hazard ratio 1.38, 95% CI 0.96-1.99, P=0.08) in Cox regression models adjusted for covariates. Conclusions- In patients with recent acute coronary syndrome but without advanced HF, aldosterone does not predict major cardiovascular events.
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| 7. |
- Schwartz, Gregory G., et al.
(författare)
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Association of Lipoprotein(a) With Risk of Recurrent Ischemic Events Following Acute Coronary Syndrome Analysis of the dal-Outcomes Randomized Clinical Trial
- 2018
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Ingår i: JAMA cardiology. - : AMER MEDICAL ASSOC. - 2380-6583 .- 2380-6591. ; 3:2, s. 164-168
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Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE It is uncertain whether lipoprotein(a) [Lp(a)], which is associated with incident cardiovascular disease, is an independent risk factor for recurrent cardiovascular events after acute coronary syndrome (ACS). OBJECTIVE To determine the association of Lp(a) concentration measured after ACS with the subsequent risk of ischemic cardiovascular events. DESIGN, SETTING, AND PARTICIPANTS This nested case-cohort analysis was performed as an ad hoc analysis of the dal-Outcomes randomized clinical trial. This trial compared dalcetrapib, the cholesteryl ester transfer protein inhibitor, with placebo in patients with recent ACS and was performed between April 2008 and September 2012 at 935 sites in 27 countries. There were 969 case patients who experienced a primary cardiovascular outcome, and there were 3170 control patients who were event free at the time of a case event and had the same type of index ACS (unstable angina ormyocardial infarction) as that of the respective case patients. Concentration of Lp(a) was measured by immunoturbidimetric assay. Data analysis for this present study was conducted from June 8, 2016, to April 21, 2017. INTERVENTIONS Patients were randomly assigned to receive treatment with dalcetrapib, 600 mg daily, or matching placebo, beginning 4 to 12 weeks after ACS. MAIN OUTCOMES AND MEASURES Death due to coronary heart disease, a major nonfatal coronary event (myocardial infarction, hospitalization for unstable angina, or resuscitated cardiac arrest), or fatal or nonfatal ischemic stroke. RESULTS The mean (SD) age was 63 (10) years for the 969 case patients and 60 (9) years for the 3170 control patients, and both cohorts were composed of predominantly male (770 case patients [79%] and 2558 control patients [81%]; P = .40) and white patients (858 case patients [89%] and 2825 control patients [89%]; P = .62). At baseline, the median (interquartile range) Lp(a) level was 12.3 (4.7-50.9) mg/dL. There was broad application of evidence-based secondary prevention strategies after ACS, including use of statins in 4030 patients (97%). The cumulative distribution of baseline Lp(a) levels did not differ between cases and controls at P = .16. Case-cohort regression analysis showed no association of baseline Lp(a) level with risk of cardiovascular events. For a doubling of Lp(a) concentration, the hazard ratio (case to control) was 1.01 (95% CI, 0.96-1.06; P = .66) after adjustment for 16 baseline variables, including assigned study treatment. CONCLUSIONS AND RELEVANCE For patients with recent ACS who are treated with statins, Lp(a) concentration was not associated with adverse cardiovascular outcomes. These findings call into question whether treatment specifically targeted to reduce Lp(a) levels would thereby lower the risk for ischemic cardiovascular events after ACS.
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