New Syntheses with Oils and Fats as Renewable Raw Materials for the Chemical Industry

Oils and fats are the most important renewable raw materials for the chemical industry. Hitherto, industrial oleochemistry has concentrated predominantly on the carboxy functionality of fatty acids but, more recently, modern synthetic methods have been applied extensively to fatty compounds for the selective functionalization of the alkyl chain. Radical, electrophilic, nucleophilic, and pericyclic as well as transition metal catalyzed additions to the C-C double bond of, for example, oleic acid as the prototype of a readily accessible, unsaturated fatty acid have led to a large number of novel fatty compounds from which interesting properties are expected. Functionalization of C-H bonds in the alkyl chain is also feasible with remarkable selectivity. Effective and highly versatile catalysts for the metathesis of esters of unsaturated fatty acids have been developed, which lead to new and interesting omega-unsaturated fatty acids. The epoxidation of unsaturated fatty acids has been developed extensively. Enzymatic reactions allow syntheses with high selectivity and yield of mono- and diglycerides and esters of carbohydrates with a variety of surfactant properties. Regio- and enantioselective microbial hydrations and hydroxylations widen the spectrum of selective reactions. Of considerable significance is that, with the use of gene technology, natural oils and fats have been improved significantly and will be improved still further, insofar as they show a more uniform and often unusual fatty acid spectrum. Numerous fatty acids are now available in a purity which makes them attractive for synthesis and as raw materials for the chemical industry.

Prevention of atrial fibrillation by Renin-Angiotensin system inhibition a meta-analysis

OBJECTIVES

The authors reviewed published clinical trial data on the effects of renin-angiotensin system (RAS) inhibition for the prevention of atrial fibrillation (AF), aiming to define when RAS inhibition is most effective.

BACKGROUND

Individual studies examining the effects of RAS inhibition on AF prevention have reported controversial results.

METHODS

All published randomized controlled trials reporting the effects of treatment with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in the primary or secondary prevention of AF were included.

RESULTS

A total of 23 randomized controlled trials with 87,048 patients were analyzed. In primary prevention, 6 trials in hypertension, 2 trials in myocardial infarction, and 3 trials in heart failure were included (some being post-hoc analyses of randomized controlled trials). In secondary prevention, 8 trials after cardioversion and 4 trials assessing the medical prevention of recurrence were included. Overall, RAS inhibition reduced the odds ratio for AF by 33% (p < 0.00001), but there was substantial heterogeneity among trials. In primary prevention, RAS inhibition was effective in patients with heart failure and those with hypertension and left ventricular hypertrophy but not in post-myocardial infarction patients overall. In secondary prevention, RAS inhibition was often administered in addition to antiarrhythmic drugs, including amiodarone, further reducing the odds for AF recurrence after cardioversion by 45% (p = 0.01) and in patients on medical therapy by 63% (p < 0.00001).

CONCLUSIONS

This analysis supports the concept of RAS inhibition as an emerging treatment for the primary and secondary prevention of AF but acknowledges the fact that some of the primary prevention trials were post-hoc analyses. Further areas of uncertainty include potential differences among specific RAS inhibitors and possible interactions or synergistic effects with antiarrhythmic drugs.

Contrasting actions of endothelin ET(A) and ET(B) receptors in cardiovascular disease

First identified as a powerful vasoconstrictor, endothelin has an extremely diverse set of actions that influence homeostatic mechanisms throughout the body. Two receptor subtypes, ET(A) and ET(B), which usually have opposing actions, mediate the actions of endothelin. ET(A) receptors function to promote vasoconstriction, growth, and inflammation, whereas ET(B) receptors produce vasodilation, increases in sodium excretion, and inhibit growth and inflammation. Potent and selective receptor antagonists have been developed and have shown promising results in the treatment of cardiovascular diseases such as pulmonary arterial hypertension, acute and chronic heart failure, hypertension, renal failure, and atherosclerosis. However, results are often contradictory and complicated because of the tissue-specific vasoconstrictor actions of ET(B) receptors and the fact that endothelin is an autocrine and paracrine factor whose activity is difficult to measure in vivo. Considerable questions remain regarding whether ET(A)-selective or nonselective ET(A)/ET(B) receptor antagonists would be useful in a range of clinical settings.

Electronic compliance monitoring in resistant hypertension: the basis for rational therapeutic decisions

OBJECTIVE

Incomplete compliance is one of several possible causes of uncontrolled hypertension. Yet, non-compliance remains largely unrecognized and is falsely interpreted as treatment resistance, because it is difficult to confirm or exclude objectively. The goal of this study was to evaluate the potential benefits of electronic monitoring of drug compliance in the management of patients with resistant hypertension.

METHODS

Forty-one hypertensive patients resistant to a three-drug regimen (average blood pressure 156/ 106 +/- 23/11 mmHg, mean +/- SD) were studied prospectively. They were informed that for the next 2 months, their presently prescribed drugs would be provided in electronic monitors, without any change in treatment, so as to provide the treating physician with a measure of their compliance. Thereafter, patients were offered the possibility of prolonging the monitoring of compliance for another 2 month period, during which treatment was adapted if necessary.

RESULTS

Monitoring of compliance alone was associated with a significant improvement of blood pressure at 2 months (145/97 +/- 20/15 mmHg, P < 0.01). During monitoring, blood pressure was normalized (systolic < 140 mmHg or diastolic < 90 mmHg) in one-third of the patients and insufficient compliance was unmasked in another 20%. When analysed according to tertiles of compliance, patients with the lowest compliance exhibited significantly higher achieved diastolic blood pressures (P = 0.04). In 30 patients, compliance was monitored up to 4 months and drug therapy was adapted whenever necessary. In these patients, a further significant decrease in blood pressure was obtained (from 150/100 +/- 18/15 to 143/94 +/- 22/11 mmHg, P = 0.04/0.02).

CONCLUSIONS

These results suggest that objective monitoring of compliance using electronic devices may be a useful step in the management of patients with refractory hypertension, as it enables physicians to take rational decisions based on reliable and objective data of drug compliance and hence to improve blood pressure control.

Molecular phylogeny of the New World monkeys (Platyrrhini, primates)

Phylogenetic relationships among the 16 extant genera of Ceboidea (the New World monkeys) were examined using aligned epsilon-globin gene sequences from 19 New World monkeys (representing all 16 extant ceboid genera), and seven catarrhines (one Old World monkey and six hominoids) and tarsier as the outgroups. The consensus maximum parsimony tree found for these epsilon-globin sequences and the levels of support from parsimony and bootstrap analyses, for the clades in this tree, provided strong evidence for a cladistic classification with the following clusters. Subtribes Callitrichina (Callithrix, Cebuella), Callimiconina (Callimico), Leontopithecina (Leontopithecus), and Saguina (Saguinus) constitute subfamily Callitrichinae, and subfamilies Callitrichinae, Aotinae (Aotus), Saimiriinae (Saimiri), and Cebinae (Cebus) constitute family Cebidae. In turn, subtribes Chiropotina (Chiropotes, Cacajao) and Pitheciina (Pithecia) constitute tribe Pithecini, tribes Pitheciini and Callicebini (Callicebus) constitute subfamily Pitheciinae, tribes Atelini (Brachyteles, Lagothrix, Ateles) and Alouattini (Alouatta) constitute subfamily Atelinae, and subfamilies Pitheciinae and Atelinae constitute family Atelidae. The two families (Cebidae and Atelidae) constitute the Ceboidea, the only extant superfamily of infraorder Platyrrhini. The sister-group relationships of Brachyteles and Lagothrix, Saguinus and Leontopithecus, and Callimico with a Cebuella/Callithrix clade is not as well supported by the parsimony and bootstrap analyses. Therefore, these relationships are not incorporated in the proposed cladistic classification. On determining branch lengths for the ceboid phylogenetic tree from only the more freely evolving noncoding sequences at the epsilon-globin locus and taking the reference age of 35 million years ago (MYA) for the New World monkey-catarrhine branch point, we estimated the age of the atelid-cebid branch point as about 20 MYA, and the ages of the next branch points, those between the subfamilies in each family, as 19-16 MYA.

Skin Sodium Concentration Correlates with Left Ventricular Hypertrophy in CKD

The pathogenesis of left ventricular hypertrophy in patients with CKD is incompletely understood. Sodium intake, which is usually assessed by measuring urinary sodium excretion, has been inconsistently linked with left ventricular hypertrophy. However, tissues such as skin and muscle may store sodium. Using ²³sodium-magnetic resonance imaging, a technique recently developed for the assessment of tissue sodium content in humans, we determined skin sodium content at the level of the calf in 99 patients with mild to moderate CKD (42 women; median [range] age, 65 [23-78] years). We also assessed total body overhydration (bioimpedance spectroscopy), 24-hour BP, and left ventricular mass (cardiac magnetic resonance imaging). Skin sodium content, but not total body overhydration, correlated with systolic BP (r=0.33, P=0.002). Moreover, skin sodium content correlated more strongly than total body overhydration did with left ventricular mass (r=0.56, P<0.001 versus r=0.35, P<0.001; P<0.01 between the two correlations). Linear regression analysis demonstrated that skin sodium content is a strong explanatory variable for left ventricular mass, unaffected by BP and total body overhydration. In conclusion, we found skin sodium content to be closely linked to left ventricular mass in patients with CKD. Interventions that reduce skin sodium content might improve cardiovascular outcomes in these patients.

SGLT-2-inhibition with dapagliflozin reduces tissue sodium content: a randomised controlled trial

Background and aims

Sodium tissue content by ²³Na magnetic resonance imaging (Na-MRI) has been validated in experimental and human studies. SGLT-2 inhibition blocks the reabsorption of glucose and of sodium in the proximal tubular cells in a 1:1 fashion. We hypothesized that SGLT-2 inhibition in patients with type 2 diabetes characterized by sodium retention leads to decreased tissue sodium content due to its pharmacological action.

Materials and methods

In a prospective double blind, placebo controlled, cross-over trial 59 patients (61 ± 7.6 years) with type 2 diabetes were randomized to either dapagliflozin 10 mg or placebo once daily for 6 weeks each. In addition to metabolic parameters and ambulatory blood pressure (BP) we analysed the sodium content in the skin and muscles of the lower leg by Na-MRI.

Results

Compared to baseline 6 weeks treatment with the SGLT-2 inhibitor dapagliflozin decreased fasting (132 ± 28 vs. 114 ± 19 mg/dl, p < 0.001), postprandial blood glucose (178 ± 66 mg/dl vs. 153 ± 46 mg/dl, p < 0.001), body weight (87.6 vs. 86.6 kg, p < 0.001) and systolic (129 ± 12 vs. 126 ± 11 mmHg, p = 0.010), and diastolic (77.4 ± 9 vs. 75.6 ± 8 mmHg, p = 0.024), 24-h ambulatory BP. Tissue sodium content in the skin was reduced after 6 weeks treatment with dapagliflozin compared to baseline [24.1 ± 6.6 vs. 22.7 ± 6.4 A.U.(arbitrary unit) p = 0.013]. No significant reduction of tissue sodium content was observed in the muscle (M. triceps surae: 20.5 ± 3.5 vs. 20.4 ± 3.7 A.U. p = 0.801). No clear significant difference in tissue water content of muscle and skin was observed after 6 weeks of treatment with dapagliflozin, compared to baseline.

Conclusion

SGLT-2 inhibition with dapagliflozin resulted in a significant decrease in tissue sodium content of the skin after 6 weeks. This observation point to a decrease of total sodium content in patients with type 2 diabetes prone to cardiovascular complications, that might be mitigated by SGLT-2 inhibition.

Trial registration The study was registered at http://www.clinicaltrials.gov (NCT02383238) retrospectively registered

Angiotensin converting enzyme inhibition and angiotensin II AT1-receptor blockade reduce the levels of asymmetrical N(G), N(G)-dimethylarginine in human essential hypertension

BACKGROUND

Asymmetrical N(G), N(G)-dimethylarginine (ADMA) is associated with impaired endothelium-dependent vasodilation in humans.

METHODS

Twenty young, male, mildly hypertensive subjects were included in a randomized, double-blind, fourfold cross-over study with placebo, enalapril (20 mg/day), eprosartan (600 mg/day), or a combination of both drugs (10 and 300 mg/day, respectively) each over 1 week, followed by a 2-week wash-out phase. After each treatment phase, ADMA concentration was measured.

RESULTS

ADMA concentration was 1.69+/-0.59 micromol/L in the placebo phase, and was significantly lower in the enalapril, eprosartan, and combination phases (1.41+/-0.29, 1.42+/-0.43, and 1.38+/-0.30 micromol/L, respectively; all P < 0.05 v placebo). Changes in ADMA levels were independent of the drugs' action on blood pressure (BP).

CONCLUSIONS

Levels of ADMA were reduced with enalapril and eprosartan therapy. Our results suggest a specific action of these drugs on ADMA levels that is independent of BP.

Molecular phylogeny of the New World monkeys (Platyrrhini, primates) based on two unlinked nuclear genes: IRBP intron 1 and epsilon-globin sequences

Nuclear sequences of the 1.8 kilobase (kb) long intron 1 of the interstitial retinol-binding protein gene (IRBP), previously determined for 11 of the 16 extant genera of New World monkeys (superfamily Ceboidea, infraorder Platyrrhini), have now been determined for the remaining 5 genera. The maximum parsimony trees found, first with IRBP sequences alone and then with tandemly combined IRBP and epsilon-globin gene sequences from the same species, supported a provisional cladistic classification with the following clusters. Subtribes Callitrichina (Callithrix, Cebuella), Callimiconina (Callimico), Leontopithecina (Leontopithecus) and Saguina (Saguinus) constitute subfamily Callitrichinae, and subfamilies Callitrichinae, Aotinae (Aotus), and Cebinae (Cebus, Saimiri) constitute family Cebidae. Subtribes Chiropotina (Chiropotes, Cacajao) and Pitheciina (Pithecia) constitute tribe Pitheciini; and tribes Pitheciini and Callicebini (Callicebus) constitute subfamily Pitheciinae. Subtribes Brachytelina (Brachyteles, Lagothrix) and Atelina (Ateles) constitute tribe Atelini, and tribes Atelini and Alouattini (Alouatta) constitute subfamily Atelinae. The parsimony results were equivocal as to whether Pitheciinae should be grouped with Atelinae in family Atelidae or have its own family Pitheciidae. The cladistic groupings of extant ceboids were also examined by different stochastic evolutionary models that employed the same stochastic process of nucleotide substitutions but alternative putative phylogenetic trees on which the nucleotide substitutions occurred. Each model, i.e., each different tree, predicted a different multinomial distribution of nucleotide character patterns for the contemporary sequences. The predicted distributions that were closest to the actual observed distributions identified the best fitting trees. The cladistic relationships depicted in these best fitting trees agreed in almost all cases with those depicted in the maximum parsimony trees.

Rapid nongenomic effects of aldosterone on human forearm vasculature

The impact of aldosterone in cardiovascular disease and hypertension has recently gained new interest. Aldosterone is now suggested to be a more common cause of hypertension than previously believed and has been linked to myocardial fibrosis, independent of its hypertensive effects. Finally, rapid nongenomic aldosterone effects have been proposed to be important in hypertension, in addition to its genomic effects. Forty-eight healthy male volunteers were examined in a randomized, placebo-controlled, double-blind crossover trial to elucidate the rapid nongenomic, vascular effects of aldosterone in humans. Forearm blood flow was measured by venous occlusion plethysmography. First, aldosterone (500 ng/min) and placebo were infused into the brachial artery for 8 minutes. The volunteers then received ascending doses of acetylcholine, NG-monomethyl-L-arginine (L-NMMA), sodium nitroprusside, or phenylephrine. Aldosterone increased forearm blood flow (P<0.001, ANOVA). The maximum effect was an increase in forearm blood flow with aldosterone of 7.9+/-2.6% compared with 0.1+/-1.9% with placebo treatment after 8 minutes. With aldosterone, L-NMMA induced a greater vasoconstriction (P<0.05, ANOVA), sodium nitroprusside induced an attenuated vasoconstriction (P<0.01, ANOVA), and phenylephrine induced an exaggerated vasoconstriction (P<0.01, ANOVA) within minutes as compared with placebo. These data suggest that aldosterone acts through rapid nongenomic effects at the endothelium by increasing NO release and at the vascular smooth muscle cells by promoting vasoconstriction. This is consistent with in vitro data showing an increase in intracellular calcium in both cell types. Disturbances of these aldosterone effects on both levels might be important in promoting hypertension.

Lipid-independent effects of statins on endothelial function and bioavailability of nitric oxide in hypercholesterolemic patients

BACKGROUND

Experimental evidence suggests a lipid-independent effect of statins on endothelial function and nitric oxide (NO) availability in humans. We investigated whether improvement in NO availability in hypercholesterolemia can be achieved rapidly with statins before lipid-lowering therapy is complete.

METHODS

We studied 41 patients (52 +/- 11 years) with low-density lipoprotein (LDL) cholesterol > or = 130 mg/dL (179 +/- 45 mg/dL) randomly assigned to treatment either with atorvastatin (20 mg/day) or cerivastatin (0.4 mg/day). Endothelium-dependent vasodilation of the forearm vasculature was measured by plethysmography and intra-arterial infusion of acetylcholine (ACh) after 3 days (n = 18) and 14 days (n = 39) of treatment. NO availability and oxidative stress were assessed by coinfusion of l-NMMA and vitamin C.

RESULTS

After 3 days of treatment, LDL-cholesterol decreased by 11.9% with a further decrease to 29.6% after 14 days ( P < .001). Endothelium-dependent vasodilation improved by +46.7% after 3 days of statin therapy compared with before therapy (ACh 48 microg/min: +15.7 +/- 10.6 vs +10.7 +/- 10.8 mL/min per 100 mL, P < .05). No further improvement in endothelium-dependent vasodilation (+42.7% compared with before therapy) could be demonstrated after 14 days of treatment (ACh 48 microg/min: +17.7 +/- 10.3 vs +12.4 +/- 9.3 mL/min per 100 mL before therapy, P < .001). Coinfusion of ACh plus vitamin C was able to improve endothelium-dependent vasodilation before but not after 3 or 14 days of statin therapy either. The improvement in endothelium-dependent vasodilation after therapy was no longer observed when the NO-synthase inhibitor l-NMMA was coinfused together with ACh.

CONCLUSIONS

Short-term lipid-lowering therapy with statins is able to improve endothelial function and NO availability almost completely after 3 days in hypercholesterolemic patients probably by decreasing oxidative stress. This improvement seems to be more rapid than the accompanying decline in LDL-cholesterol and not related to these lipid changes. This finding can support the concept of lipid-independent effects of statins in humans.

Effect of AT1 receptor blockade on endothelial function in essential hypertension

BACKGROUND

Angiotensin II adversely affects endothelial function and NO availability. We analyzed the effect of AT(1) receptor blockade on endothelium-dependent vasodilation and basal nitric oxide (NO) production and release in hypertensive patients.

METHODS AND RESULTS

Sixty patients (53 +/- 10 years) with essential hypertension were randomized to 6 weeks of double-blind therapy with either valsartan (80 mg), hydrochlorothiazide (HCTZ) (25 mg), or placebo once daily. Basal NO production and release was assessed by measuring forearm blood flow (FBF) in response to intra-arterial infusion of N(G)-monomethyl-L-arginine (L-NMMA), and endothelium-dependent vasodilation by measuring FBF in response to intra-arterial administration of acetylcholine, respectively. Intra-arterial infusion of noradrenaline and sodium nitroprusside was used to assess endothelium-independent changes in FBF. Blood pressure (BP) similarly decreased with active treatments (P < .001). After valsartan treatment, the decrease of FBF in response to L-NMMA was augmented (4 micromol/min L-NMMA, -1.3 +/- 1.2 after v -0.5 +/- 1.1 mL/min/100 mL before therapy, P < .02; 8 micromol/min L-NMMA: -1.7 +/- 1.3 after v -1.1 +/- 1.2 mL/min 100 mL before therapy, P < .05). No improvement was found after placebo or HCTZ treatment. Changes in L-NMMA-induced decrease of FBF with valsartan treatment were not related to BP changes. Neither drug substantially modified the response of FBF induced by intra-arterial infusion of acetylcholine, noradrenaline, and sodium nitroprusside.

CONCLUSIONS

The AT(1) receptor blockade with valsartan improved basal NO production and release. The effect seems to be BP independent, as BP reduction with HCTZ failed to increase NO availability.

DNA evidence on the phylogenetic systematics of New World monkeys: support for the sister-grouping of Cebus and Saimiri from two unlinked nuclear genes

Previous inferences from epsilon-globin gene sequences on cladistic relationships among the 16 extant genera of Ceboidea (the New World monkeys) were tested by strength of grouping and bootstrap values for the clades in the most parsimonious trees found: for this epsilon data set enlarged with additional Cebus and Saimiri orthologues; for another nuclear DNA sequence data set consisting of IRBP (interstitial retinol-binding protein gene) intron 1 orthologues; and for tandemly combined epsilon and IRBP sequences. Different ceboid species of the same genus always grouped strongly together as demonstrated by results on Cebus (capuchin monkeys), Saimiri (squirrel monkeys), Callicebus (titi monkeys), Aotus (night monkeys), Ateles (spider monkeys), and Alouatta (howler monkeys). Other strong groupings that could be represented as monophyletic taxa in a cladistic classification were: Cebuella (pygmy marmoset) and Callithrix (marmoset) into subtribe Callitrichina; Callitrichina, Callimico (Goeldi's monkey), Leontopithecus (lion tamarin), and Saguinus (tamarin) into subfamily Callitrichinae; Callitrichinae, Aotus, Cebus, and Saimiri into family Cebidae; Cacajao (uakari monkey) and Chiropotes (saki) into subtribe Chiropotina; Chiropotina and Pithecia (bearded saki) into tribe Pitheciini; Pitheciini and Callicebus into subfamily Pitheciinae; Brachyteles (woolly spider monkey), Lagothrix (woolly monkey), and Ateles into tribe Atelini; and Atelini and Alouatta into subfamily Atelinae. In addition the epsilon and IRBP results congruently grouped (but at lesser strengths) Brachyteles and Lagothrix into subtribe Brachytelina within Atelini, and also Cebus and Saimiri into subfamily Cebinae within Cebidae. Because the IRBP results weakly grouped Pitheciinae with Cebidae, whereas the epsilon results weakly grouped Pitheciinae with Atelinae, the present evidence is best represented in an interim cladistic classification of ceboids by dividing the superfamily Ceboidea into three families: Atelidae, Pitheciidae, and Cebidae.

Collecting duct-derived endothelin regulates arterial pressure and Na excretion via nitric oxide

Mice with a collecting duct-specific deletion of endothelin-1 are hypertensive and have impaired Na excretion. Because endothelin-1 activates NO synthase (NOS) in the collecting duct, we hypothesized that impaired renal NO production in knockout mice exacerbates the hypertensive state. Control and knockout mice were treated chronically with N(G)-nitro-l-arginine methyl ester, and blood pressure (BP) and urinary nitrate/nitrite excretion were assessed. On a normal Na diet, knockout systolic BP was 18 mm Hg greater than in controls. N(G)-nitro-l-arginine methyl ester increased BP in control mice by 30 mm Hg and 10 mm Hg in collecting duct-specific deletion of endothelin-1 knockout mice, thereby abolishing the difference in systolic BP between the groups. A high-Na diet increased BP similarly in both groups. Urinary nitrate/nitrite excretion was lower in knockout mice than in controls on normal or high Na intake. In separate experiments, renal perfusion pressure was adjusted in anesthetized mice, and urinary nitrate/nitrite and Na excretion were determined. Similar elevations of BP increased urinary Na and nitrate/nitrite excretion in control mice but to a significantly lesser extent in knockout mice. Isoform-specific NOS activity and expression were determined in renal inner medulla homogenates from control and knockout mice. NOS1 and NOS3 activities were lower in knockout than in control mice given normal or high-Na diets. However, NOS1 or NOS3 protein expressions were similar in both groups on normal or high-Na intake. These data demonstrate that collecting duct-derived endothelin-1 is important in the following: (1) chronic N(G)-nitro-l-arginine methyl ester-induced hypertension; (2) full expression of pressure-dependent changes in sodium excretion; and (3) control of inner medullary NOS1 and NOS3 activity.

Incorporating kidney disease measures into cardiovascular risk prediction: Development and validation in 9 million adults from 72 datasets

BACKGROUND

Chronic kidney disease (CKD) measures (estimated glomerular filtration rate [eGFR] and albuminuria) are frequently assessed in clinical practice and improve the prediction of incident cardiovascular disease (CVD), yet most major clinical guidelines do not have a standardized approach for incorporating these measures into CVD risk prediction. "CKD Patch" is a validated method to calibrate and improve the predicted risk from established equations according to CKD measures.

METHODS

Utilizing data from 4,143,535 adults from 35 datasets, we developed several "CKD Patches" incorporating eGFR and albuminuria, to enhance prediction of risk of atherosclerotic CVD (ASCVD) by the Pooled Cohort Equation (PCE) and CVD mortality by Systematic COronary Risk Evaluation (SCORE). The risk enhancement by CKD Patch was determined by the deviation between individual CKD measures and the values expected from their traditional CVD risk factors and the hazard ratios for eGFR and albuminuria. We then validated this approach among 4,932,824 adults from 37 independent datasets, comparing the original PCE and SCORE equations (recalibrated in each dataset) to those with addition of CKD Patch.

FINDINGS

We confirmed the prediction improvement with the CKD Patch for CVD mortality beyond SCORE and ASCVD beyond PCE in validation datasets (Δc-statistic 0.027 [95% CI 0.018-0.036] and 0.010 [0.007-0.013] and categorical net reclassification improvement 0.080 [0.032-0.127] and 0.056 [0.044-0.067], respectively). The median (IQI) of the ratio of predicted risk for CVD mortality with CKD Patch vs. the original prediction with SCORE was 2.64 (1.89-3.40) in very high-risk CKD (e.g., eGFR 30-44 ml/min/1.73m² with albuminuria ≥30 mg/g), 1.86 (1.48-2.44) in high-risk CKD (e.g., eGFR 45-59 ml/min/1.73m² with albuminuria 30-299 mg/g), and 1.37 (1.14-1.69) in moderate risk CKD (e.g., eGFR 60-89 ml/min/1.73m² with albuminuria 30-299 mg/g), indicating considerable risk underestimation in CKD with SCORE. The corresponding estimates for ASCVD with PCE were 1.55 (1.37-1.81), 1.24 (1.10-1.54), and 1.21 (0.98-1.46).

INTERPRETATION

The "CKD Patch" can be used to quantitatively enhance ASCVD and CVD mortality risk prediction equations recommended in major US and European guidelines according to CKD measures, when available.

FUNDING

US National Kidney Foundation and the NIDDK.

Measurement of kidney perfusion by magnetic resonance imaging: comparison of MRI with arterial spin labeling to para-aminohippuric acid plasma clearance in male subjects with metabolic syndrome

BACKGROUND

Magnetic resonance imaging with arterial spin labeling (MRI-ASL) is a non-invasive approach to measure organ perfusion. We aimed to examine whether MRI-ASL kidney perfusion measurements are related to measurements of renal plasma flow (RPF) by para-aminohippuric acid (PAH) plasma clearance and whether changes of kidney perfusion in response to treatment with telmisartan can be detected by MRI-ASL.

METHODS

Twenty-four patients with metabolic syndrome and an estimated creatinine clearance according to Cockroft and Gault of > or =60 ml/min were included in the study. Kidney perfusion was assessed by MRI-ASL measurements of a single coronal kidney slice (with flow-sensitive alternating inversion recovery and true fast imaging with steady-state processing sequence) and by measurements of RPF using PAH plasma clearance before and after 2 weeks of treatment with the angiotensin receptor blocker telmisartan. All MRI-ASL examinations were performed on a 1.5 T scanner.

RESULTS

Two weeks of therapy with telmisartan led to a significant increase of RPF (from 313 +/- 47 to 348 +/- 69 ml/min/m, P = 0.007) and MRI-ASL kidney perfusion measurements (from 253 +/- 20 to 268 +/- 25 ml/min/100 g, P = 0.020). RPF measurements were related with MRI-ASL kidney perfusion measurements (r = 0.575, P < 0.001). Changes of RPF measurements and changes of MRI-ASL kidney perfusion measurements in response to treatment with telmisartan revealed a close relationship when expressed in absolute terms (r = 0.548, P = 0.015) and in percentage changes (r = 0.514, P = 0.025).

CONCLUSIONS

Perfusion measurement of a single coronal kidney slice by MRI-ASL is able to approximate kidney perfusion and to approximate changes in kidney perfusion due to pharmacological intervention.

Marmoset phylogenetics, conservation perspectives, and evolution of the mtDNA control region

Marmosets (genus Callithrix) are a diverse group of platyrrhine primates with 13-15 purported taxa, many of them considered endangered. Morphological analyses constitute most of the basis for recognition of these forms as distinct taxa. The purpose of this study was to provide a molecular view, based on mitochondrial control region sequences, of the evolutionary history of the marmosets, concomitant with a molecular phylogenetic perspective on species diversity within the group. An additional purpose was to provide the first comparative examination of a complete New World monkey control region sequence with those of other mammals. The phylogenetic analyses provide convincing support for a split between the Atlantic forest and Amazonian marmosets, with the inclusion of the pygmy marmoset (Cebuella pygmaea) at the base of the Amazonian clade. The earliest branch of the Atlantic forest group was C. aurita. In the Amazonian group, the analyses do not support the recognition of C. humeralifer and the recently described C mauesi as distinct taxa. They do, however, support a clear distinction between C. argentata and a strongly supported mixed clade of C. humeralifer and C. mauesi. In the Atlantic forest group, the phylogenetic tree suggests mixing between C. penicillata, C. kuhli, and possibly C. jacchus. Most of the sequence features characteristic of other mammal control regions were also evident in marmosets, with the exception that conserved sequence blocks (CSBs) 2 and 3 were not clearly identifiable. Tandem repeat units often associated with heteroplasmy in a variety of other mammals were not evident in the marmoset sequences.

Functional gene testing of the Glu298Asp polymorphism of the endothelial NO synthase

OBJECTIVES

To test whether the Glu298Asp polymorphism of the endothelial nitric oxide synthase (eNOS) gene is of functional relevance in humans by altering endothelium-dependent vasodilation.

BACKGROUND

The Asp298 variant of the eNOS gene product has been associated with arterial hypertension, coronary artery disease and myocardial infarction. The pathogenetic mechanism has not yet been elucidated. Since endothelium-dependent vasodilation has been shown to be impaired in these disorders, we hypothesized that the Glu298Asp polymorphism of the eNOS gene influences endothelium-dependent vasodilation.

METHODS

In 80 patients with normal or elevated cholesterol, endothelium-dependent and -independent vasodilation was assessed. Forearm blood flow was measured by plethysmography in response to intra-arterial (i.a.) infusion of 12 and 48 microg/min acetylcholine and 3.2 and 12.8 microg/min nitroprusside, respectively. NG-monomethyl-L-arginine (L-NMMA) in doses of 4, 8 and 16 micromol/min was infused to test basal nitric oxide (NO) production and release. Genomic DNA was extracted from blood samples to determine the Glu298Asp polymorphism of the eNOS gene at position 1917 G/T after BanII restriction.

RESULTS

Baseline parameters (age, gender, blood pressure, body mass index, cholesterol level) were similar across the genotypes. Genotype frequencies did not deviate from the Hardy-Weinberg equilibrium. No differences in forearm blood flow to i.a. acetylcholine (average increase: + 554 +/- 371%), nitroprusside or L-NMMA infusion were found across the eNOS genotypes, neither for endothelium-dependent or endothelium-independent vasodilation, nor for basal NO production and release. Our sample size of n = 80 had a power of > 80% (beta = 0.20) with a P value < 0.05 (alpha = 0.05) to detect a 200% difference in forearm blood flow response to 48 microg/min acetylcholine.

CONCLUSIONS

At a power of 80%, we can exclude a relevant effect on endothelium-dependent vasodilation due to the eNOS Glu298Asp polymorphism. Thus, our functional genetic study does not suggest any biological effect of the eNOS Glu298Asp genotype on the cardiovascular system via an influence on endothelium-dependent vasodilation.

A randomized controlled trial of the effect of spironolactone on left ventricular mass in hemodialysis patients

Mineralocorticoid receptor antagonists have beneficial effects on left ventricular remodeling, cardiac fibrosis, and arrhythmia in heart failure, but efficacy and safety in dialysis patients is less clear. We evaluated the effect of spironolactone on left ventricular mass (LVM), an independent predictor of all-cause and cardiovascular mortality, in hemodialysis patients. In this placebo-controlled, parallel-group trial, 97 hemodialysis patients (23% female; mean age 60.3 years) were randomized to spironolactone 50 mg once daily (n=50) or placebo (n=47). The primary efficacy endpoint was change in LVM index (LVMi) from baseline to 40 weeks as determined by cardiac magnetic resonance imaging. Safety endpoints were development of hyperkalemia and change in residual renal function. There was no significant change in LVMi in participants randomized to spironolactone compared to placebo (-2.86±11.87 vs. 0.41±10.84 g/m²). There was also no difference in the secondary outcomes of mean 24-hour systolic or diastolic ambulatory blood pressure, left ventricular ejection fraction, 6-minute walk test distance, or New York Heart Association functional class. Moderate hyperkalemia (pre-dialysis potassium levels of 6.0-6.5 mmol/L) was more frequent with spironolactone treatment (155 vs. 80 events), but severe hyperkalemia (≥6.5 mmol/L) was not (14 vs. 24 events). Changes in residual urine volume and measured glomerular filtration rate did not differ between groups. There were no deaths in the spironolactone group and 4 deaths in the placebo group. Thus, treatment with 50 mg spironolactone did not change left ventricular mass index, cardiac function, or blood pressure in hemodialysis patients. Spironolactone increased the frequency of moderate hyperkalemia, but did not increase severe hyperkalemia.

Evaluation of nurses' errors associated in the preparation and administration of medication in a pediatric intensive care unit

The objectives of this study were to determine the frequency and the types of errors which occur regarding the preparation and the administration of medication and to identify the main causes of these errors in a pediatric intensive care unit (PICU) at the University Hospital in Lausanne (Switzerland). In this prospective study, based on the observation of nurses' activities, the data were collected over a period of 10 weeks. The error classification was based on the American Society of Hospital Pharmacy (ASHP) definitions. The frequency of errors was calculated as the sum of all noted errors divided by the total administered drugs, plus the sum of all omitted drugs, multiplied by 100. The sum of all given doses plus all omitted doses gives the 'total opportunity for errors'. This total was 275 and the total frequency of errors was 26.9%. The most frequent errors were wrong-time errors (32.4%), wrong-administration-technique errors (32.4%) and preparation errors (23.0%). In relation with other studies conducted under comparable conditions, a lesser number of omissions and wrong-time errors were observed. On the contrary, administration-technique and dose-preparation errors were more frequent at our hospital. A program of systematic assistance and survey by professional pharmacists could improve the quality of the preparation and administration of medication in the PICU.

Evidence on primate phylogeny from epsilon-globin gene sequences and flanking regions

Phylogenetic relationships among various primate groups were examined based on sequences of epsilon-globin genes. epsilon-globin genes were sequenced from five species of strepsirhine primates. These sequences were aligned and compared with other known primate epsilon-globin sequences, including data from two additional strepsirhine species, one species of tarsier, 19 species of New World monkeys (representing all extant genera), and five species of catarrhines. In addition, a 2-kb segment upstream of the epsilon-globin gene was sequenced in two of the five strepsirhines examined. This upstream sequence was aligned with five other species of primates for which data are available in this segment. Domestic rabbit and goat were used as outgroups. This analysis supports the monophyly of order Primates but does not support the traditional prosimian grouping of tarsiers, lorisoids, and lemuroids; rather it supports the sister grouping of tarsiers and anthropoids into Haplorhini and the sister grouping of lorisoids and lemuroids into Strepsirhini. The mouse lemur (Microcebus murinus) and dwarf lemur (Cheirogaleus medius) appear to be most closely related to each other, forming a clade with the lemuroids, and are probably not closely related to the lorisoids, as suggested by some morphological studies. Analysis of the epsilon-globin data supports the hypothesis that the aye-aye (Daubentonia madagascariensis) shares a sister-group relationship with other Malagasy strepsirhines (all being classified as lemuroids). Relationships among ceboids agree with findings from a previous epsilon-globin study in which fewer outgroup taxa were employed. Rates of molecular evolution were higher in lorisoids than in lemuroids.

Prevalence of undiagnosed stage 3 chronic kidney disease in France, Germany, Italy, Japan and the USA: results from the multinational observational REVEAL-CKD study

OBJECTIVES

REVEAL-CKD aims to estimate the prevalence of, and factors associated with, undiagnosed stage 3 chronic kidney disease (CKD).

DESIGN

Multinational, observational study.

SETTING

Data from six country-specific electronic medical records and/or insurance claims databases from five countries (France, Germany, Italy, Japan and the USA [two databases]).

PARTICIPANTS

Eligible participants (≥18 years old) had ≥2 consecutive estimated glomerular filtration rate (eGFR) measurements (calculated from serum creatinine values, sex and age) taken from 2015 onwards that were indicative of stage 3 CKD (≥30 and <60 mL/min/1.73 m²). Undiagnosed cases lacked an International Classification of Diseases 9/10 diagnosis code for CKD (any stage) any time before, and up to 6 months after, the second qualifying eGFR measurement (study index).

MAIN OUTCOME MEASURES

The primary outcome was point prevalence of undiagnosed stage 3 CKD. Time to diagnosis was assessed using the Kaplan-Meier approach. Factors associated with lacking a CKD diagnosis and risk of diagnostic delay were assessed using logistic regression adjusted for baseline covariates.

RESULTS

The prevalence of undiagnosed stage 3 CKD was 95.5% (19 120/20 012 patients) in France, 84.3% (22 557/26 767) in Germany, 77.0% (50 547/65 676) in Italy, 92.1% (83 693/90 902) in Japan, 61.6% (13 845/22 470) in the US Explorys Linked Claims and Electronic Medical Records Data database and 64.3% (161 254/250 879) in the US TriNetX database. The prevalence of undiagnosed CKD increased with age. Factors associated with undiagnosed CKD were female sex (vs male, range of odds ratios across countries: 1.29-1.77), stage 3a CKD (vs 3b, 1.81-3.66), no medical history (vs a history) of diabetes (1.26-2.77) or hypertension (1.35-1.78).

CONCLUSIONS

There are substantial opportunities to improve stage 3 CKD diagnosis, particularly in female patients and older patients. The low diagnosis rates in patients with comorbidities that put them at risk of disease progression and complications require attention.

TRIAL REGISTRATION

NCT04847531.

Sequences of the primate epsilon-globin gene: implications for systematics of the marmosets and other New World primates

Sequences of the epsilon-globin gene were determined for five species of marmosets, along with approximately 2 kb of 5' flanking sequence. An analysis of these data, compared with those of other primates strongly supports the classification of Callithrix jacchus and C. geoffroyi into the jacchus group, and C. argentata and C. mauesi into the argentata group. The pygmy marmoset, formerly identified as Cebuella pygmaea joined strongly to the argentata group, indicating that without the pygmy marmoset the genus Callithrix would be paraphyletic. Our data support recent studies which indicate that C. pygmaea should be included in the genus Callithrix. Relationships among other primates were as indicated by previous studies of epsilon-globin sequences. Divergence times were estimated according to a local molecular clock. These calculations indicated the divergence of C. mauesi and C. argentata to be approximately 1.6-1.9 Myr (million years ago), and the most recent common ancestor of the marmosets to be between 4.5 and 4.7 Myr. The latter estimate corresponds well to the date of 4.6 Myr calculated from an independent data set.

Circulating uromodulin inhibits vascular calcification by interfering with pro-inflammatory cytokine signalling

AIMS

Uromodulin is produced exclusively in the kidney and secreted into both urine and blood. Serum levels of uromodulin are correlated with kidney function and reduced in chronic kidney disease (CKD) patients, but physiological functions of serum uromodulin are still elusive. This study investigated the role of uromodulin in medial vascular calcification, a key factor associated with cardiovascular events and mortality in CKD patients.

METHODS AND RESULTS

Experiments were performed in primary human (HAoSMCs) and mouse (MOVAS) aortic smooth muscle cells, cholecalciferol overload and subtotal nephrectomy mouse models and serum from CKD patients. In three independent cohorts of CKD patients, serum uromodulin concentrations were inversely correlated with serum calcification propensity. Uromodulin supplementation reduced phosphate-induced osteo-/chondrogenic transdifferentiation and calcification of HAoSMCs. In human serum, pro-inflammatory cytokines tumour necrosis factor α (TNFα) and interleukin-1β (IL-1β) co-immunoprecipitated with uromodulin. Uromodulin inhibited TNFα and IL-1β-induced osteo-/chondrogenic signalling and activation of the transcription factor nuclear factor kappa-light-chain-enhancer of activated β cells (NF-kB) as well as phosphate-induced NF-kB-dependent transcriptional activity in HAoSMCs. In vivo, adeno-associated virus (AAV)-mediated overexpression of uromodulin ameliorated vascular calcification in mice with cholecalciferol overload. Conversely, cholecalciferol overload-induced vascular calcification was aggravated in uromodulin-deficient mice. In contrast, uromodulin overexpression failed to reduce vascular calcification during renal failure in mice. Carbamylated uromodulin was detected in serum of CKD patients and uromodulin carbamylation inhibited its anti-calcific properties in vitro.

CONCLUSIONS

Uromodulin counteracts vascular osteo-/chondrogenic transdifferentiation and calcification, at least in part, through interference with cytokine-dependent pro-calcific signalling. In CKD, reduction and carbamylation of uromodulin may contribute to vascular pathology.