Metabolic types of muscle in the sheep: I. Myosin ATPase, glycolytic, and mitochondrial enzyme activities

The metabolic characteristics of 12 skeletal muscles of the sheep were studied. Glycolytic activities (hexokinase, glycogen synthetase I and D, phosphorylase a and b, phosphofructokinase) were measured. Myofibrillar ATPase activity was evaluated. Oxygen consumption, respiratory control and carnitine palmityl transferase, isocitrate dehydrogenase, succinate dehydrogenase and cytochrome oxidase activities were measured in isolated mitochondria. Three metabolic types could be distinguished; (1) essentially oxidative slow twitch muscles, typified by the supraspinatus and infraspinatus, having low ATPase activity, (2) fast twitch red muscles, typified by the longissimus dorsi and the semimembranosus, having a higher ATPase activity and both high oxidative and high glycolytic activity, and (3) essentially glycolytic fast twitch muscles, typified by the tensor fascia lata and the semitendinosus, having the highest ATPase activity.

Agricultural pesticide exposure and the molecular connection to lymphomagenesis

The t(14;18) translocation constitutes the initiating event of a causative cascade leading to follicular lymphoma (FL). t(14;18) translocations are present in blood from healthy individuals, but there is a trend of increased prevalence in farmers exposed to pesticides, a group recently associated with higher risk of t(14;18)⁺ non-Hodgkin's lymphoma development. A direct connection between agricultural pesticide use, t(14;18) in blood, and malignant progression, however, has not yet been demonstrated. We followed t(14;18) clonal evolution over 9 yr in a cohort of farmers exposed to pesticides. We show that exposed individuals bear particularly high t(14;18) frequencies in blood because of a dramatic clonal expansion of activated t(14;18)⁺ B cells. We further demonstrate that such t(14;18)⁺ clones recapitulate the hallmark features of developmentally blocked FL cells, with some displaying aberrant activation-induced cytidine deaminase activity linked to malignant progression. Collectively, our data establish that expanded t(14;18)⁺ clones constitute bona fide precursors at various stages of FL development, and provide a molecular connection between agricultural pesticide exposure, t(14;18) frequency in blood, and clonal progression.

Characterization of the t(14;18) BCL2-IGH Translocation in Farmers Occupationally Exposed to Pesticides

Increasing incidence of non-Hodgkin's lymphoma have been associated repeatedly with farming occupation and particular attention focused on the role of pesticide exposure to potentially explain part of this trend. A genetic hallmark of non-Hodgkin's lymphoma is the presence of recurrent chromosomal translocations involving the immunoglobulin heavy chain gene. Of these, the t(14;18), which deregulates BCL2 expression and inhibits apoptosis, is the most frequent in follicular lymphoma and has been detected consistently in peripheral blood lymphocytes of healthy individuals. As BCL2-IGH translocation represents an early step of the malignant process, we evaluated the occurrence and molecular characteristics of BCL2-IGH translocation in 56 individuals occupationally exposed to pesticides in open field farming They were selected from a representative cohort of farmers with a well-defined assessment of pesticide exposure taking into account potential confounding factors, smoking, sunlight, and age. Our results suggest that occupational exposure to pesticides would increase BCL2-IGH prevalence together with the frequency of BCL2-IGH-bearing cells especially during the high pesticide use period. Distribution of BCL2 or IGH breakpoint positions seemed to be independent of pesticide exposure and was similar to those found in other healthy populations or lymphoma patients. Finally, these results provide additional evidence that BCL2-IGH translocation measurements could be a measure of acquired genetic instability in relation to genotoxic exposure in a gene directly relevant in term of lymphomagenesis.

Proteolytic activity of proteasome on myofibrillar structures

The physiologic function of proteasome remains unclear. Evidence suggests a role in degradation of ubiquitin-protein conjugates, MHC antigen presentation, and some specificity of substrate within certain cell types. To explore further the properties of proteasome we have examined its effect on a well defined structure, the myofibril. We find that despite its large size (20S) proteasome is able to degrade myofibrils and intact, permeabilized muscle fibrils. The proteins degraded showed some specificity because actin, myosin and desmin were degraded faster than alpha-actinin, troponin T and tropomyosin. Changes in ultrastructure were slow and included a general loss of structure with Z and I bands effected before the M band and costameres.

Changes in 20S proteasome activity during ageing of the LOU rat

Muscular functions decline and muscle mass decreases during ageing. In the rat, there is a 27% decrease in muscle protein between 18 and 34 months of age. We examined age-related changes in the proteasome-dependent proteolytic pathway in rats at 4, 18, 24, 29 and 34 months of age. The three best characterised activities of the proteasome (chymotrypsin-like, trypsin-like and peptidylglutamyl peptide hydrolase) increased to 29 months and then decreased in the senescent animal. These variations in activity were accompanied by an identical change in the quantity of 20S proteasome measured by Western blot, whereas the S4 subunit of the 19S regulator and the quantity of ubiquitin-linked proteins remained constant. mRNA of subunits C3, C5, C9, and S4 increased in the senescent animal, but ubiquitin mRNA levels were unchanged. These findings suggest that the 20S proteasome may be partly responsible for the muscular atrophy observed during ageing in the rat.

PI3K/mTOR dual inhibitor NVP-BEZ235 decreases Mcl-1 expression and sensitizes ovarian carcinoma cells to Bcl-xL-targeting strategies, provided that Bim expression is induced

We previously showed that Bcl-xL and Mcl-1 cooperatively protect platinum-resistant ovarian cancer cells from apoptosis. Here we assessed the anticancer potential of combining ABT-737-induced inhibition of Bcl-xL with Mcl-1 inhibition via PI3K/Akt/mTOR pathway disruption using NVP-BEZ235. NVP-BEZ235 inhibited cell proliferation without inducing apoptosis. It strongly repressed Mcl-1 expression and induced Puma expression in both cell lines tested while differentially modulating Bim between the two. Interestingly, NVP-BEZ235 efficiently sensitized ovarian carcinoma cells to ABT-737, provided that Bim expression was induced. Moreover, inhibiting the ERK1/2 pathway restored Bim expression and sensitized low Bim-expressing cancer cells to the BEZ235/ABT-737 treatment.

Effect of endurance training and/or fish oil supplemented diet on cytoplasmic fatty acid binding protein in rat skeletal muscles and heart

Endurance training and/or a fish oil supplemented diet affect cytoplasmic fatty acid binding protein (FABP(c)) content in rat skeletal muscles and heart. After 8 weeks of swimming, trained rats exhibited higher FABP(c) content in the extensor digitorum longus (EDL) and in the gastrocnemius than did control rats (30%). The FABP(c) increase was associated with an increase of citrate synthase activity (85% and 93%, respectively, in the two muscles), whereas lactate dehydrogenase activity decreased significantly. In contrast, in the soleus and in the heart we did not observe any effect of exercise either on FABP(c) or on the metabolic profile. Therefore, increasing oxidative capacities of muscle by exercise resulted in a concomitant increase of the FABP(c) content. Giving a polyunsaturated fatty acid (omega-3) supplemented diet for eight weeks induced a large rise of the FABP(c) in EDL (300%), gastrocnemius (250%), soleus (50%) and heart (15%) without a concurrent accumulation of intramuscular triglycerides or modification of the citrate synthase activity, suggesting that polyunsaturated fatty acids may increase FABP(c) content by up-regulating fatty acid metabolism genes via peroxisome proliferator-activated receptor alpha activation. Endurance trained rats fed with an omega-3 diet had similar FABP(c) content in the gastrocnemius muscle when compared to sedentary omega-3 fed rats, whereas an additive effect of exercise and diet was observed in the EDL. The FABP(c) in the soleus and in the heart of rats fed with omega-3 supplements remained constant whether rats performed exercise or not. As a result, both exercise and omega-3-enriched diet influenced FABP(c) content in muscle. These two physiological treatments presumably acted on FABP(c) content by increasing fatty acid flux within the cell.

Hemodynamic performance during maximum exercise in adult patients with the ross operation and comparison with normal controls and patients with aortic bioprostheses

This study examines the resting and exercise hemodynamic performance of the pulmonary autografts in the aortic position as well as of the homografts used for right ventricular outflow reconstruction in patients undergoing the Ross operation. Previous studies have reported excellent resting hemodynamics in patients who underwent aortic valve replacement with a pulmonary autograft. However, there are very few studies of their hemodynamic performance during exercise. Twenty adult subjects who underwent the Ross operation and 12 normal control subjects were submitted to maximum romp bicycle exercise. The valve effective orifice areas and transvalvular gradients of both aortic (autograft) and pulmonary (homograft) valves were measured at rest and at peak of maximum exercise using Doppler echocardiography. Valve areas were indexed for body surface area. The hemodynamics of the aortic valve were very similar in Ross subjects and in control subjects at rest and during exercise. However, the indexed valve area of the pulmonary valve at rest was significantly (p < 0.001) lower in the Ross subjects (1.10 +/- 0.46 cm2/ m2) than in the control subjects (1.95 +/- 0.41 cm2/m2), resulting in higher (p = 0.004) mean gradients at rest (Ross: 9 +/- 7 mm Hg vs control: 2 +/- 1 mm Hg) and at peak exercise (Ross: 21 +/- 14 mm Hg vs control: 7 +/- 2 mm Hg). The pulmonary autograft provided excellent hemodynamics in the aortic position either at rest or during maximum exercise, whereas moderately high gradients were found during exercise across the homograft implanted in the pulmonary valve position. Future improvement of the Ross procedure should be oriented toward the search of new methods to prevent the deterioration of the homografts.

Ethylene glycol poisoning in a child treated with 4-methylpyrazole

OBJECTIVE

The alcohol dehydrogenase inhibitor 4-methylpyrazole (4-MP) is a new antidote of ethylene glycol (EG) intoxication. The purpose of the present case report was to demonstrate 4-MP efficiency in EG poisoning in a 4-year-old child.

METHOD AND RESULTS

4-MP Treatment was performed 7 hours after EG ingestion. Plasma EG and 4-MP concentrations were measured 2 hours after each infusion of 4-MP. Plasma 4-MP concentrations were in the range of the values reported to block EG metabolism. The efficiency of 4-MP treatment was confirmed by the rapid correction of metabolic acidosis without alkalization and by the increase in EG half-life. No adverse effect of 4-MP was observed.

CONCLUSION

This child ingested a potentially lethal dose of EG despite a high concentration of bittering agent in antifreeze. EG poisoning was treated efficiently by 4-MP without recourse to hemodialysis.

BMP-2, hypoxia, and COL1A1/HtrA1 siRNAs favor neo-cartilage hyaline matrix formation in chondrocytes

Osteoarthritis (OA) is an irreversible pathology that causes a decrease in articular cartilage thickness, leading finally to the complete degradation of the affected joint. The low spontaneous repair capacity of cartilage prevents any restoration of the joint surface, making OA a major public health issue. Here, we developed an innovative combination of treatment conditions to improve the human chondrocyte phenotype before autologous chondrocyte implantation. First, we seeded human dedifferentiated chondrocytes into a collagen sponge as a scaffold, cultured them in hypoxia in the presence of a bone morphogenetic protein (BMP), BMP-2, and transfected them with small interfering RNAs targeting two markers overexpressed in OA dedifferentiated chondrocytes, that is, type I collagen and/or HtrA1 serine protease. This strategy significantly decreased mRNA and protein expression of type I collagen and HtrA1, and led to an improvement in the chondrocyte phenotype index of differentiation. The effectiveness of our in vitro culture process was also demonstrated in the nude mouse model in vivo after subcutaneous implantation. We, thus, provide here a new protocol able to favor human hyaline chondrocyte phenotype in primarily dedifferentiated cells, both in vitro and in vivo. Our study also offers an innovative strategy for chondrocyte redifferentiation and opens new opportunities for developing therapeutic targets.

Platinum compounds sensitize ovarian carcinoma cells to ABT-737 by modulation of the Mcl-1/Noxa axis

Ovarian cancer is the leading cause of death from gynecological cancer. The anti-apoptotic protein Bcl-x(L) is frequently overexpressed in ovarian carcinoma which correlates with chemotherapy resistance. It has been demonstrated that Bcl-x(L) cooperates with another anti-apoptotic protein, Mcl-1, to protect ovarian cancer cells against apoptosis, and that their concomitant inhibition induces massive cell death. Here, we examined the interest of ABT-737, a potent BH3-mimetic molecule targeting Bcl-x(L), both alone and in combination with Mcl-1 modulators, in ovarian cancer cell lines. As a single agent, ABT-737 was ineffective at promoting cell death in the four cell lines we tested in vitro. However, the specific inhibition of Mcl-1 by siRNA dramatically increased the sensitivity of chemoresistant cells to ABT-737. Platinum compounds also sensitize to ABT-737 by dose-dependently decreasing Mcl-1 expression or by increasing the expression of pro-apoptotic BH3-only proteins Noxa and, to a lower extent, Bim. Furthermore, we demonstrated that Noxa accumulation was involved in apoptosis occurring in response to the combination of ABT-737 and platinum compounds, since cells were protected from apoptosis by its silencing. Moreover, the combination was also highly cytotoxic ex vivo in sliced SKOV3 tumor nodes. However we observed in these slices a strong basal expression of Noxa and apoptotic cell death in response to ABT-737 alone. Therefore, we have revealed that the modulation of the Mcl-1/Noxa axis by platinum compounds results in a strong sensitization of chemoresistant ovarian carcinoma cells to ABT-737, which could constitute a promising therapeutic in these cancers.

The effect of proteasome on myofibrillar structures in bovine skeletal muscle

When bovine myofibrils are incubated with the 20S proteasome their structure is rapidly damaged with loss of material, particularly from the Z discs and I bands. After 24 hr of incubation the myofibrils rupture and debris appears. Certain myofibrillar proteins, including nebulin, myosin, actin and tropomyosin, are hydrolysed during the incubation; others are solubilised (α-actinin). The 20S proteasome completely and rapidly hydrolyses purified myofibrillar proteins in an energy-independent manner. This shows that the 20S proteasome probably plays a role in the postmortem transformation of muscle and more generally in the hydrolysis of cellular proteins.(1).

Distribution of proteasomes and of the five proteolytic activities in rat tissues

Five peptidase activities (ChT-L, T-L, PGPH, BrAAP, and SNAAP) of the proteasome, and its caseinolytic activity, were measured in crude extracts of 10 rat tissues under experimental conditions simulating those found in vivo, thereby eliminating the alterations observed with the purified enzyme. The total and individual peptidase activities varied considerably from one tissue to another, whereas the proteolytic activity measured with [(14)C]methylcasein varied no more than twofold. The tissue-specific variations in individual peptidase activities may reflect tissue-specific differences in proteasome subunit composition, or the presence of regulators. Immunological assay using an antibody directed against the iota (alpha1) subunit showed that there was no correlation between protein abundance and peptidase activity. The results also show that the different peptidase activities are not representative of proteasome distribution in the different tissues.

Identification of predictive factors of response to the BH3-mimetic molecule ABT-737: an ex vivo experiment in human serous ovarian carcinoma

Ovarian cancers are addicted to Bcl-xL and Mcl-1, antiapoptotic members of the Bcl-2 family. Bcl-xL can be inhibited by the BH3-mimetic ABT-737. In vitro, ABT-737 can induce apoptosis of cancer cells, and its activity is potentiated by Mcl-1 inactivation. Herein, we assessed the sensitivity of human ovarian tumor nodes to ABT-737 when combined with carboplatin, which can indirectly inhibit Mcl-1. Fresh samples from 25 patients with high-grade serous ovarian cancer (HGSOC) who were chemo-naïve and had undergone surgery were prospectively exposed ex vivo to ABT-737 ± carboplatin. The treatment effect was studied on sliced tumor nodes by assessment of cleaved-caspase 3 immunostaining. We also studied the association between baseline Bcl-2 family protein expression (via immunohistochemistry) and the response of nodes to treatment. ABT-737 induced apoptosis as a single agent but its efficacy was not improved by the addition of carboplatin. Bim was frequently expressed (20/25) and its absence or low expression was associated with the absence of response to ABT-737, p value = 0.019 by Fisher's test and sensitivity = 93%, (95% confidence interval, 66-100). Moreover, we observed that in tumors in which Bim was expressed, a low expression of phospho-Erk1/2 or Mcl-1 improved the proportion of responses. This pilot study showed that ABT-737 has promise as monotherapy for HGSOC in a specific subgroup of tumors. Bim, Mcl-1, and phospho-Erk1/2 appeared to be relevant biomarkers that could be used for the selection of patients in the design of clinical trials using Navitoclax (an orally available compound related to ABT-737).

Metabolic types of muscle in the sheep: II. Lactate dehydrogenase activity and LDH isoenzyme distribution

Lactate dehydrogenase activity and isoenzyme distribution were measured in fast-twitch red, slow-twitch red and fast-twitch white muscles in the sheep. Total enzyme activity is higher in fast-twitch muscles irrespective of their colour type. Isoenzymes M4 and H4 bear an inverse relationship, M4 being predominant in fast-twitch red and white muscles, and H4 in heart muscle and slow-twitch red muscles.

Genotoxicant accumulation and cellular defence activation in bivalves chronically exposed to waterborne contaminants from the Seine River

The aim of the present work was to investigate genotoxicant accumulation and biological responses of zebra mussels and blue mussels collected along a pollution gradient in the Seine estuary and in the Seine Bay. The sampling area included three contaminated and one reference sites for each species. The study focused on polyaromatic hydrocarbons (PAH), lindane, polychlorobiphenyls (PCB) and metals known to be potential genotoxicants and/or reactive oxygen species (ROS) inducers. Enzymatic activities related to cellular defence systems including the phase II enzyme glutathione S-transferase (GST) and three antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were measured in gills. DNA adducts and DNA strand breaks (Comet assay) were measured in digestive gland and hemocytes, respectively. Species differences were observed in metal accumulation (As and Pb), GPx activity and DNA adduct formation. A marked upstream-downstream gradient was reported for PAH body burden and to a lesser extent for PCB and metals with the highest values measured just downstream the industrialized area of Rouen. GST and SOD activities in gills of bivalves were positively related to PAH and metals body burden, respectively. Activation of those cellular defences may prevent accumulation of electrophilic metabolites and free radicals and thus may protect DNA and others macromolecules against oxidation and adduction. Although DNA strand breaks and bulky adducts were detected in both species, levels were relatively low and no significant site differences were observed in June 2003. Our results indicate a clear relationship between genotoxicant accumulation and positive activation of detoxification and antioxidant systems but poor consequences in term of DNA damage for wild population of mussels inhabiting the Seine estuary.

ZAP-70 intron1 DNA methylation status: determination by pyrosequencing in B chronic lymphocytic leukemia

ZAP-70 expression is a strong prognostic indicator in chronic lymphocytic leukemia. However, ZAP-70 quantification by flow cytometry lacks sufficient standardization. Based upon the correlation between ZAP-70 expression and its gene methylation status, we have developed a quantitative pyrosequencing assay for the determination of ZAP-70 methylation adapted for routine use. Methylation in four CpG pairs (C-223, C-243, C-254, and C-267) in the first intron of ZAP-70 is associated with repression of ZAP-70. Moreover, it correlates with CD38 expression (n=111, p<.0001), IgHv mutation status (n=106, p<.0001), time to treatment (p<.0001), and overall survival (p=.0014). Pyrosequencing of ZAP-70 provides a good alternative to flow cytometry.

Predictive Relevance of Circulating miR-622 in Patients with Newly Diagnosed and Recurrent High-Grade Serous Ovarian Carcinoma

BACKGROUND

Identifying patients with high-grade serous ovarian cancer (HGSOC) who will respond to treatment remains a clinical challenge. We focused on miR-622, a miRNA involved in the homologous recombination repair (HRR) pathway, and we assessed its predictive value in serum prior to first-line chemotherapy and at relapse.

METHODS

Serum miR-622 expression was assessed in serum prior to first-line platinum-based chemotherapy in a prospective multicenter study (miRNA Serum Analysis, miRSA, NCT01391351) and a retrospective cohort (Biological Resource Center, BRC), and was also studied at relapse. Progression-free survival (PFS) and overall survival (OS) were used as primary and secondary endpoints prior to first-line chemotherapy and OS as a primary endpoint at relapse.

RESULTS

The group with high serum miR-622 expression was associated with a significantly lower PFS (15.4 versus 24.4 months; adjusted HR 2.11, 95% CI 1.2 3.8, P = 0.015) and OS (29.7 versus 40.6 months; adjusted HR 7.68, 95% CI 2.2-26.2, P = 0.0011) in the miRSA cohort. In the BRC cohort, a high expression of miR-622 was also associated with a significantly lower OS (22.8 versus 35.9 months; adjusted HR 1.98, 95% CI 1.1-3.6, P = 0.026). At relapse, high serum miR-622 was associated with a significantly lower OS (7.9 versus 20.6 months; adjusted HR 3.15, 95% CI 1.4-7.2, P = 0.0062). Serum miR-622 expression is a predictive independent biomarker of response to platinum-based chemotherapy for newly diagnosed and recurrent HGSOC.

CONCLUSIONS

These results may open new perspectives for HGSOC patient stratification and monitoring of resistance to platinum-based and poly(ADP-ribose)-polymerase-inhibitor-maintenance therapies, facilitating better and personalized treatment decisions.

Anticancer and chemosensitizing effects of 2,3-DCPE in ovarian carcinoma cell lines: link with ERK activation and modulation of p21WAF1/CIP1, Bcl-2 and Bcl-xL expression

OBJECTIVE

Emergence of chemoresistance in the course of treatments with platinum drugs remains a major hurdle to ovarian carcinoma therapy. We have previously shown that acquisition of cisplatin resistance by OAW42-R ovarian carcinoma cells was associated with the loss of ERK activation in response to cisplatin. To try to sensitize this cell line by restoring ERK activation, we tested a new synthetic compound, 2[[3-(2,3-dichlorophenoxy)propyl]amino]ethanol (2,3-DCPE), which was described to induce ERK activation and to display anticancer properties.

METHODS

We treated four ovarian carcinoma cell lines with 2,3-DCPE, alone or combined with cisplatin. We characterized its effects on apoptosis induction and proliferation and correlated them with molecular modulations.

RESULTS

We showed that 2,3-DCPE induced cell death and ERK phosphorylation in a time- and concentration-dependent manner in OAW42-R cells. 2,3-DCPE-triggered apoptosis was also associated with the inhibition of Bcl-2 expression and, to a less extent, with that of Bcl-xL. Treatment with 2,3-DCPE also elicited a strong G0/G1 cell cycle arrest, accompanied with p21WAF1/CIP1 up-regulation. All of these effects revealed to be irreversible. Moreover, 2,3-DCPE exerted a cytostatic effect on OAW42, IGROV1-R10 and SKOV3 ovarian carcinoma cells, the sensitivity to 2,3-DCPE appearing in particular linked with a low basal level of P-ERK. Finally, we showed that 2,3-DCPE increased the cytotoxic effect of cisplatin in OAW42-R resistant cells.

CONCLUSION

Our results emphasized the potential interest of 2,3-DCPE, used alone or combined with cisplatin, for ovarian carcinoma treatment. The absence of basal P-ERK may constitute a predictive marker of response to this novel therapy.

BCL-2/JH translocation in peripheral blood lymphocytes of unexposed individuals: lack of seasonal variations in frequency and molecular features

BCL-2/J(H) rearrangement has been proposed as a biomarker for evaluating the genotoxicity of occupational and environmental exposures. Available data on time-related modification of this rearrangement in peripheral blood lymphocytes in unexposed healthy individuals is scarce. We investigated the characteristics of BCL-2/J(H) rearrangements in 33 adults unexposed to genotoxins at 2 seasonal time points: winter and spring. BCL-2/J(H) rearrangement was detected in 79% of individuals (detection limit = 8.48 x 10(-8)). Its frequency ranged from <1 to 40 translocations per million lymphocytes with a significant (p = 0.04) positive correlation with age. No significant modifications of BCL-2/J(H) rearrangement frequency or in the number of clones harboring this rearrangement were observed according the 2 time points. No obvious influence of season-related environmental factors on frequency or molecular features of BCL-2/J(H) rearrangements was found in this population suggesting that this would not be a confounding factor.

Metabolic and contractile differentiation of rabbit muscles during growth

1. A study was carried out of post-natal evolution of the oxidative, glycolytic and contractile capacities in various types of rabbit muscle. 2. At birth, muscles are non-differentiated and present very limited metabolic and contractile activity, metabolism is mainly oxidative in all muscles. 3. Although muscular discrimination is manifest from the sixth week after birth, the glycolytic metabolism reaches its maximum capacity only after six to eight weeks. 4. Subsequently, oxidative metabolic capacity steadily decreases until adulthood.

How to talk so kids will listen & listen so kids will talk: a randomized controlled trial evaluating the efficacy of the how-to parenting program on children's mental health compared to a wait-list control group

BACKGROUND

Basic parenting research reveals that child mental health is associated with optimal parenting, which is composed of three key dimensions (structure, affiliation and autonomy support). The present study aims to test the efficacy of the parenting program "How to talk so kids will listen & listen so kids will talk" (French version), thought to address all of these dimensions, in promoting children's mental health. We predict that the How-to Parenting Program will promote child mental health by fostering optimal parenting.

METHODS

In this randomized controlled trial (RCT), the seven-week parenting group was offered to parents of 5- to 12-year-old children, in their local grade school. Children's mental health assessments were questionnaire-based (parent, child and teacher reports) and took place at pre- (T1) and post- (T2) intervention as well as at 6-month (T3) and 1-year (T4) follow-ups. We compared children whose parents took part in the program with children whose parents did not take part in it until the completion of the trial (i.e., 1 year wait-list control groups). The primary outcome is children's psychological problems (externalizing and internalizing). Secondary outcomes include parenting, the putative mediator of the expected benefits of the program on child mental health, as well as positive indicators of child mental health (strengths and subjective well-being) and parents' own mental health.

DISCUSSION

To our knowledge, this is the first RCT to test the efficacy of the "How to talk so kids will listen & listen so kids will talk" program in promoting child mental health. In addition to the close correspondence between basic parenting research and the selected program, strengths of this study include its feasibility, monitoring of potentially confounding variables, ecological validity and inclusion of positive indicators of mental health.

TRIAL REGISTRATION

Current clinical trial number is NCT03030352 . Ongoing study, retrospectively registered on January 2017. No amendment to initial protocol.