Olivier Phan

Uremia Accelerates both Atherosclerosis and Arterial Calcification in Apolipoprotein E Knockout Mice

Chronic renal failure (CRF) favors the development of atherosclerosis and excessive calcification of atheromatous lesions. CRF was induced in apolipoprotein E knockout (apoE(-/-)) mice to study (1) a possible acceleration of aortic atherosclerosis, (2) the degree and type of vascular calcification, and (3) factors involved in the calcification process. For creating CRF, 8-wk-old apolipoprotein E gene knockout (apoE(-/-)) mice underwent partial kidney ablation. Control animals underwent sham operation. Aortic atherosclerotic plaques and calcification were evaluated using quantitative morphologic image processing. At 6 wk after nephrectomy, CRF mice had significantly higher serum urea, cholesterol, and triglyceride concentrations than non-CRF controls. The serum levels of advanced oxidation protein products were elevated in the uremic group and were correlated with serum urea levels. Atherosclerotic lesions in thoracic aorta were significantly larger in uremic apoE(-/-) mice than in nonuremic controls. The relative proportion of calcified area to total surface area of both atherosclerotic lesions and lesion-free vascular tissue was increased in aortic root of uremic apoE(-/-) mice when compared with controls. The calcium deposits were made of hydroxyapatite and calcite crystals. In addition, plaques from uremic animals showed a significant increase in collagen content, whereas the degree of macrophage infiltration was comparable in both groups. There was no difference in mean arterial BP. These findings demonstrate that CRF aggravates atherosclerosis in apoE(-/-) mice. Moreover, CRF enhances arterial calcification at both atheromatous intimal sites and atheroma-free medial sites. We anticipate that this experimental model will be useful to test treatment strategies aimed at decreasing the accelerated atherosclerosis and arterial calcification in uremia.

Sevelamer Prevents Uremia-Enhanced Atherosclerosis Progression in Apolipoprotein E–Deficient Mice

Background— The novel phosphate binder sevelamer has been shown to prevent the progression of aortic and coronary calcification in uremic patients. Whether it also decreases the progression of atheromatous plaques is unknown. The aim of our study was to examine the effect of sevelamer administration on the development of atherosclerosis and aortic calcification in the uremic apolipoprotein E–deficient mouse as an established model of accelerated atherosclerosis. Methods and Results— Female mice were randomly assigned to 4 groups: 2 groups of nonuremic mice (sevelamer versus control) and 2 groups of uremic mice (sevelamer versus control). Sevelamer was given at 3% with chow. The increases in serum phosphorus concentration and calcium-phosphorus product observed in uremic control mice were prevented by sevelamer. Serum total cholesterol was increased in the 2 uremic mouse groups and remained unchanged in response to sevelamer. After 8 weeks of sevelamer treatment, uremic mice exhibited a significantly lower degree of atherosclerosis (P<0.001) and vascular calcification than uremic control mice. Of interest, sevelamer exerted an effect on both intima and media calcification (P=0.005) in uremic mice. Among possible mechanisms involved, we found no evidence for the modulation by sevelamer of inflammation or selected uremic toxins. In contrast, nitrotyrosine staining as a measure of oxidative damage was significantly decreased in response to sevelamer treatment in control and uremic mice (P<0.005). Conclusions— Sevelamer delays not only vascular calcification but also atherosclerotic lesion progression in uremic apolipoprotein E–deficient mice. It opens the possibility of a cholesterol-independent action of sevelamer on atheroma formation via effects on mineral metabolism, oxidative stress, or both.

Affect dysregulation in cannabis abusers

Psychiatric comorbidity and impaired emotional functioning have been previously reported in adult substance abusers but have been less well documented in adolescents. Thus, we investigated mental health problems and emotion regulation abilities in adolescents and young adults with cannabis dependence. Moreover, we explored the relationships between consumption modalities and affective style. Therefore, 32 cannabis abusers (CA) and 30 healthy controls completed a battery of self-reports measuring depression (BDI-13), anxiety (STAI-Y), alexithymia (TAS20; BVAQ-B), anhedonia (PAS; SAS), and sensation seeking (SSS). The MINI was administered to evaluate cannabis dependence and axis I DSM-IV comorbid diagnoses. A semi-structured clinical interview was given to determine psychoactive substance use. Statistical analyses revealed that more than half of the CA reported at least one other non-drug or alcohol comorbid diagnosis. The most common were mood and anxiety disorders. CA subjects scored significantly higher on all affective dimensions except alexithymia total scores; however, they had greater scores for the two subscales measuring the difficulties in identifying feelings. Logistic regressions demonstrated that CA subjects were more likely to experience high levels of trait anxiety, physical anhedonia and sensation seeking than the controls. Various correlations were observed between the affective scores and the substance considered. The amount of substance use and, particularly, the prevalence of polydrug use we observed are alarming. This study demonstrates that cannabis dependence in adolescents and young adults is related to a great psychological distress and specific emotional dimensions and puts emphasis on the importance of substance use prevention as early as middle school.

The calcimimetic R-568 retards uremia-enhanced vascular calcification and atherosclerosis in apolipoprotein E deficient (apoE―/―) mice

OBJECTIVE Secondary hyperparathyroidism of chronic kidney disease promotes vascular calcification. Calcimimetics reduce serum parathyroid hormone, calcium (Ca), and phosphorus by calcium-sensing receptor (CaR) activation. Here we examined possible effects of the calcimimetic R-568 (R-568) on the progression of aortic calcification and atherosclerosis in apoE(-/-) mice with chronic renal failure (CRF) and the potential implication of aortic smooth muscle cell CaR. METHODS AND RESULTS ApoE(-/-) mice were assigned to 3 CRF groups and 1 non-CRF group receiving daily gavage with R-568, calcitriol, or vehicle. Serum Ca and phosphorus and parathyroid gland volume of CRF mice were decreased by R-568, whereas elevated serum FGF23 and total cholesterol remained unchanged. Both aortic plaque and non-plaque calcification was lower in R-568 mice, and so was atherosclerotic plaque area fraction. In vitro, R-568 induced a decrease in smooth muscle cell calcification when cultured in high phosphate medium. This decrease was abolished in CaR-SiRNA-transfected cells. CONCLUSIONS The calcimimetic R-568 delayed the progression of both aortic calcification and atherosclerosis in uremic apoE(-/-) mice. This effect was mediated via a better control of hyperparathyroidism including serum Ca and phosphorus. Direct vascular CaR activation also could have played a role in the observed effects.

Vitamin D: a review on its effects on muscle strength, the risk of fall, and frailty

Vitamin D is the main hormone of bone metabolism. However, the ubiquitary nature of vitamin D receptor (VDR) suggests potential for widespread effects, which has led to new research exploring the effects of vitamin D on a variety of tissues, especially in the skeletal muscle. In vitro studies have shown that the active form of vitamin D, calcitriol, acts in myocytes through genomic effects involving VDR activation in the cell nucleus to drive cellular differentiation and proliferation. A putative transmembrane receptor may be responsible for nongenomic effects leading to rapid influx of calcium within muscle cells. Hypovitaminosis D is consistently associated with decrease in muscle function and performance and increase in disability. On the contrary, vitamin D supplementation has been shown to improve muscle strength and gait in different settings, especially in elderly patients. Despite some controversies in the interpretation of meta-analysis, a reduced risk of falls has been attributed to vitamin D supplementation due to direct effects on muscle cells. Finally, a low vitamin D status is consistently associated with the frail phenotype. This is why many authorities recommend vitamin D supplementation in the frail patient.

Multidimensional family therapy lowers the rate of cannabis dependence in adolescents: A randomised controlled trial in Western European outpatient settings

BACKGROUND Noticing a lack of evidence-based programmes for treating adolescents heavily using cannabis in Europe, government representatives from Belgium, France, Germany, The Netherlands, and Switzerland decided to have U.S.-developed multidimensional family therapy (MDFT) tested in their countries in a trans-national trial, called the International Need for Cannabis Treatment (INCANT) study. METHODS INCANT was a 2 (treatment condition)×5 (time) repeated measures intent-to-treat randomised effectiveness trial comparing MDFT to Individual Psychotherapy (IP). Data were gathered at baseline and 3, 6, 9 and 12 months thereafter. Study participants were recruited at outpatient secondary level addiction, youth, and forensic care clinics in Brussels, Berlin, Paris, The Hague, and Geneva. Participants were adolescents from 13 through 18 years of age with a recent cannabis use disorder. 85% were boys; 40% were of foreign descent. One-third had been arrested for a criminal offence in the past 3 months. Three primary outcomes were assessed: (1) treatment retention, (2) prevalence of cannabis use disorder and (3) 90-day frequency of cannabis consumption. RESULTS Positive outcomes were found in both the MDFT and IP conditions. MDFT outperformed IP on the measures of treatment retention (p<0.001) and prevalence of cannabis dependence (p=0.015). MDFT reduced the number of cannabis consumption days more than IP in a subgroup of adolescents reporting more frequent cannabis use (p=0.002). CONCLUSIONS Cannabis use disorder was responsive to treatment. MDFT exceeded IP in decreasing the prevalence of cannabis dependence. MDFT is applicable in Western European outpatient settings, and may show moderately greater benefits than IP in youth with more severe substance use.

INCANT: A transnational randomized trial of Multidimensional Family Therapy versus treatment as usual for adolescents with cannabis use disorder

BackgroundIn 2003, the governments of Belgium, France, Germany, the Netherlands and Switzerland agreed that there was a need in Europe for a treatment programme for adolescents with cannabis use disorders and other behavioural problems. Based on an exhaustive literature review of evidence-based treatments and an international experts meeting, Multidimensional Family Therapy (MDFT) was selected for a pilot study first, which was successful, and then for a joint, transnational randomized controlled trial named INCANT (INternational CAnnabis Need for Treatment).Methods/designINCANT is a randomized controlled trial (RCT) with an open-label, parallel group design. This study compares MDFT with treatment as usual (TAU) at and across sites in Brussels, Berlin, Paris, The Hague and Geneva. Assessments are at baseline and at 3, 6, 9 and 12 months after randomization. A minimum of 450 cases in total is required; sites will recruit 60 cases each in Belgium and Switzerland, and a maximum of 120 each in France, Germany and the Netherlands.Eligible for INCANT are adolescents from 13 through 18 years of age with a cannabis use disorder (dependence or abuse), with at least one parent willing to take part in the treatment. Randomization is concealed to, and therefore beyond control by, the researcher/site requesting it. Randomization is stratified as to gender, age and level of cannabis consumption.Assessments focus on substance use; mental function; behavioural problems; and functioning regarding family, school, peers and leisure time.For outcome analyses, the study will use state of the art latent growth curve modelling techniques, including all randomized participants according to the intention-to-treat principle.INCANT has been approved by the appropriate ethical boards in Belgium, France, Germany, the Netherlands, Switzerland, and the University of Miami Miller School of Medicine. INCANT is funded by the (federal) Ministries of Health of Belgium, Germany, the Netherlands, Switzerland, and by MILDT: the Mission Interministerielle de Lutte Contra la Drogue et de Toximanie, France.DiscussionUntil recently, cannabis use disorders in adolescents were not viewed in Europe as requiring treatment, and the co-occurrence of such disorders with other mental and behavioural problems was underestimated. This has changed now.Initially, there was doubt that a RCT would be feasible in treatment sectors and countries with no experience in this type of study. INCANT has proven that such doubts are unjustified. Governments and treatment sites from the five participating countries agreed on a sound study protocol, and the INCANT trial is now underway as planned.Trial registrationISRCTN51014277

Chronic kidney disease bone and mineral disorder (CKD–MBD) in apolipoprotein E-deficient mice with chronic renal failure

BACKGROUND Chronic kidney disease (CKD) is associated with disorders of mineral and bone metabolism (MBD) which include renal osteodystrophy and vascular calcifications. This is of clinical concern because the high risk of cardiovascular (CVD) complications observed in uremic patients may be linked with bone disease. In this context, our aim was to characterize the bone lesions in CKD-apolipoprotein E-deficient mice (apoE(-/-)) and analyze their relationships with the vascular calcifications which these animals develop rapidly in this model. With ApoE being also involved in bone metabolism, we compared the effects of CRF on the bone of apoE(-/-) mice to those observed in wild type mice (WT) of the same genetic background, C57/BL6. METHODS After CRF creation or sham surgery, 10 week-old female apoE(-/-) and WT mice were randomized to 4 groups (n=10-14/group) and fed with standard diet. Eight weeks later, animals were euthanized. Serum, aorta and femur were sampled. Femurs were imaged with 3-dimensional microtomography (microCT) and processed for bone histomorphometry (BHM). Additional quantitative histology was performed on atherosclerotic and calcified lesions in the aortas of apoE(-/-) mice. RESULTS First, apoE(-/-) mice exhibited higher cortical (10%) and trabecular (31%) bone mass than WT. CRF led to a further increase in trabecular BV/TV in WT and in apoE(-/-) mice (10.2% and 77.2%, respectively). We observed a similar increase in osteoid surface and osteoblastic parameters in CRF mice of both genotypes while resorption parameters were less augmented by CRF in apoE(-/-) mice. Finally, based on either BHM or microCT we found positive correlations between the extent of atherosclerotic lesions and bone volume parameters, and between the size of plaque calcification and osteoclast parameters in apoE(-/-) mice. CONCLUSION ApoE deficiency is associated with an increase in bone mass and volumetric mineral density in 20 week-old female mice. Bone mass is further increased, whereas bone mineral density is decreased, in response to CRF in association with histological features of osteitis fibrosa. Finally, our findings of correlations between changes in bone and aortic lesions in apoE(-/-) mice, are compatible with the hypothesis of a link between bone and vascular disease and require further study.

Implementation fidelity of Multidimensional Family Therapy in an international trial

Implementation fidelity, a critical aspect of clinical trials research that establishes adequate delivery of the treatment as prescribed in treatment manuals and protocols, is also essential to the successful implementation of effective programs into new practice settings. Although infrequently studied in the drug abuse field, stronger implementation fidelity has been linked to better outcomes in practice but appears to be more difficult to achieve with greater distance from model developers. In the INternational CAnnabis Need for Treatment (INCANT) multi-national randomized clinical trial, investigators tested the effectiveness of Multidimensional Family Therapy (MDFT) in comparison to individual psychotherapy (IP) in Brussels, Berlin, Paris, The Hague, and Geneva with 450 adolescents with a cannabis use disorder and their parents. This study reports on the implementation fidelity of MDFT across these five Western European sites in terms of treatment adherence, dose and program differentiation, and discusses possible implications for international implementation efforts.

PA21, a New Iron-Based Noncalcium Phosphate Binder, Prevents Vascular Calcification in Chronic Renal Failure Rats

Chronic renal failure (CRF) is associated with the development of secondary hyperparathyroidism and vascular calcifications. We evaluated the efficacy of PA21, a new iron-based noncalcium phosphate binder, in controlling phosphocalcic disorders and preventing vascular calcifications in uremic rats. Rats with adenine-diet-induced CRF were randomized to receive either PA21 0.5, 1.5, or 5% or CaCO3 3% in the diet for 4 weeks, and were compared with uremic and nonuremic control groups. After 4 weeks of phosphate binder treatment, serum calcium, creatinine, and body weight were similar between all CRF groups. Serum phosphorus was reduced with CaCO3 3% (2.06 mM; P ≤ 0.001), PA21 1.5% (2.29 mM; P < 0.05), and PA21 5% (2.21 mM; P ≤ 0.001) versus CRF controls (2.91 mM). Intact parathyroid hormone was strongly reduced in the PA21 5% and CaCO3 3% CRF groups to a similar extent (1138 and 1299 pg/ml, respectively) versus CRF controls (3261 pg/ml; both P ≤ 0.001). A lower serum fibroblast growth factor 23 concentration was observed in the PA21 5%, compared with CaCO3 3% and CRF, control groups. PA21 5% CRF rats had a lower vascular calcification score compared with CaCO3 3% CRF rats and CRF controls. In conclusion, PA21 was as effective as CaCO3 at controlling phosphocalcic disorders but superior in preventing the development of vascular calcifications in uremic rats. Thus, PA21 represents a possible alternative to calcium-based phosphate binders in CRF patients.