Evolution of Sleep Complaints in Myotonic Dystrophy Type 1: A 9-Year Longitudinal Study.

The objective was to characterize the progression of sleep complaints in 115 dystrophy type 1 (DM1) patients who filled out a sleep questionnaire twice at a 9-year interval. Daytime napping (22.1% vs. 34.5%, p < 0.05), early awakenings (11.4% vs 21.1%, p < 0.05), nonrestorative sleep (39.5% vs 51.8%, p < 0.05), stimulant use (7.0% vs 19.3%, p < 0.01), breathing cessation (10.7% vs 23.2%, p < 0.01), and nighttime urination (42.5% vs 54.9%, p < 0.05) increased between Time 1 and Time 2. Sleep-related complaints are prominent and augment rapidly in DM1 patients. Physicians need to better identify and treat them to help alleviate the burden they impose on patients and their caregivers.

Évolution des troubles du sommeil dans la dystrophie myotonique de type 1 : une étude longitudinale de 9 ans.L'objectif était de caractériser l'évolution des plaintes liées au sommeil chez 115 patients atteints de dystrophie myotonique de type 1 (DM1) ayant rempli un questionnaire sur le sommeil à deux reprises à 9 ans d'intervalle. La prévalence des siestes (22,1 % vs 34,5 %, p < 0,05), des réveils matinaux précoces (11,4 % vs 21,1 %, p < 0,05), du sommeil non réparateur (39,5 % vs 51,8 %, p < 0,05), de la consommation de stimulants (7,0 % vs 19,3 %, p < 0,01), des arrêts respiratoires (10,7 % vs 23,2 %, p < 0,01) et des mictions nocturnes (42,5 % vs 54,9 %, p < 0,05) a augmenté entre le temps 1 et le temps 2. Les plaintes liées au sommeil sont fréquentes et augmentent rapidement dans la DM1. Les médecins doivent mieux les identifier et les traiter pour aider à alléger le fardeau qu'ils imposent aux patients et à leurs aidants.

A Blue-Enriched Light Intervention Counteracts the Alertness Decrement Among Mine Workers on Extended 12-Hour Night Shift Periods.

OBJECTIVE: The aim of the study is to assess whether a blue-enriched light intervention improves nocturnal alertness and daytime sleep of night workers. METHODS: Thirteen miners performing 12-hour night shifts for 12 consecutive nights were exposed to a baseline and a blue-enriched light condition. All subjects wore an actigraph and completed a Psychomotor Vigilance Task at the beginning and at the end of each shift. Data were analyzed with linear mixed models. RESULTS: In the blue-enriched light condition, the daily increase in median reaction time (RT), mean RT, slowest 10% of RT, and fastest 10% of RT was lower than that observed in the baseline condition between day 1 and 12 ( P ≤ 0.05). CONCLUSIONS: The addition of blue-enriched light during a long period of extended night shifts counteracts most of the daily decline in nocturnal alertness observed in the standard lighting condition, irrespectively of sleep duration and sleep efficiency.

Screening and Characterization of Some Lactobacillaceae for Detection of Cholesterol-Lowering Activities.

Dyslipidemia, specifically abnormal levels of low-density lipoprotein cholesterol (LDL-C), is an important risk factor of cardiovascular disease. Evidence showing the promising abilities of probiotics to lower total cholesterol or LDL-C has, however, not yet convinced experts to recommend probiotic bacteria as treatment for blood lipid management. Therefore, there are opportunities for the development of new efficient cholesterol-lowering probiotics. Bile salt hydrolase (BSH) and feruloyl esterase (FAE) are bacterial enzymes proposed to explain the cholesterol-lowering capacity of some bacteria and have both been shown to be responsible for lipid reduction in vivo. Here, in order to select for cholesterol-lowering bacteria, 70 strains related to Lactobacillaceae were screened for BSH and FAE activities. Based on this two-way screening approach, two bacteria were selected and assessed for their capacity to assimilate cholesterol in vitro, another suggested mechanism. Lactobacillus acidophilus CL1285 showed BSH and FAE activity as well as capacity to assimilate cholesterol in vitro. Lactiplantibacillus plantarum CHOL-200 exhibited BSH activity and ability to assimilate cholesterol. These properties observed in vitro make both strains good probiotic candidates for the management of dyslipidemia. Further investigation is needed to assess their ability to reduce blood cholesterol in human trial.

Responsiveness of Daytime Sleepiness and Fatigue Scales in Myotonic Dystrophy Type 1.

Daytime sleepiness and fatigue are prominent symptoms of myotonic dystrophy type 1 (DM1) that can be amenable to treatment in the context of randomized controlled trials. No study has yet documented whether self-reported measures of daytime sleepiness and fatigue can detect change over time and the meaning of this change. The aim was to explore indicators of responsiveness to change and interpretability for the Daytime Sleepiness Scale and the Fatigue Severity Scale in 115 DM1 prospectively followed patients. Results suggest that these two self-reported questionnaires are sufficiently sensitive to detect changes beyond expected measurement error over time in this population.

Survival in the Three Common Variants of Primary Progressive Aphasia: A Retrospective Study in a Tertiary Memory Clinic.

Knowledge on the natural history of the three main variants of primary progressive aphasia (PPA) is lacking, particularly regarding mortality. Moreover, advanced stages and end of life issues are rarely discussed with caregivers and families at diagnosis, which can cause more psychological distress. We analyzed data from 83 deceased patients with a diagnosis of PPA. We studied survival in patients with a diagnosis of logopenic variant (lvPPA), semantic variant (svPPA), or non-fluent variant (nfvPPA) and examined causes of death. From medical records, we retrospectively collected data for each patient at several time points spanning five years before the first visit to death. When possible, interviews were performed with proxies of patients to complete missing data. Results showed that survival from symptom onset and diagnosis was significantly longer in svPPA than in lvPPA (p = 0.002) and nfvPPA (p < 0.001). No relevant confounders were associated with survival. Mean survival from symptom onset was 7.6 years for lvPPA, 7.1 years for nfvPPA, and 12 years for svPPA. The most common causes of death were natural cardio-pulmonary arrest and pneumonia. Aspiration pneumonia represented 23% of deaths in nfvPPA. In conclusion, this pilot study found significant differences in survival between the three variants of PPA with svPPA showing the longest and nfvPPA showing more neurologically-related causes of death.

Good Sleep Quality and Progressive Increments in Vigilance During Extended Night Shifts: A 14-Day Actigraphic Study in Underground Miners.

OBJECTIVE: Assess the change in sleep and vigilance of underground miners during long periods of extended shifts. METHODS: Seventy miners worked 14 consecutive 12-hour day and/or night shifts. Also, they wore an actigraph and completed a visual analog scale for vigilance four times per shift. Linear regression models with mixed effects were used. RESULTS: Sleep efficiency was higher during day shifts than during night shifts (86,5 vs 85.5, P < 0.05) but sleep duration did not differ (6:34 vs 6:44, n.s.). Mean vigilance level at Time 3 (02h00) was significantly lower than that at Time 1 (19h00) during the first 10 night shifts whereas mean vigilance level at Time 4 (05h30) remained significantly lower for the 14 night shifts. CONCLUSIONS: Underground miners exhibit good sleep quality despite evidence of limited circadian adaptation in terms of nighttime vigilance.

Appearance Esteem Trajectory According to Three Different Sources of Support Among Adolescents Over a School Year.

Although social support has been linked to body satisfaction, there has been little research on the effect of differential sources of support on the trajectory of appearance esteem over time. To address this gap, this study explored changes in adolescents' appearance esteem to perceived social support over one year. Data were collected from 339 Canadian adolescents (54.57% females) in Grade 7 (Mage = 12.05) and Grade 10 (Mage = 15.14). Multilevel growth modeling revealed that perceived social support from fathers was not associated with appearance esteem, whereas mothers' support had the strongest effect on appearance esteem, consistently over time. Friends' support was also related to an increase in the appearance esteem trajectory, but only for older students. Overall, this prospective study provides a better understanding of the unique contribution of three different sources of social support during adolescence for preventing negative appearance esteem, beyond the effects of other related variables.

Predicting daytime sleepiness and fatigue: a 9-year prospective study in myotonic dystrophy type 1.

OBJECTIVE: Daytime sleepiness and fatigue are prominent symptoms of myotonic dystrophy type I (DM1) that exact a heavy toll on patients' quality of life, but information is scarce on their predictive factors. This study aimed to determine factors that may influence levels of daytime sleepiness and fatigue in a large cohort of DM1 patients followed for 9 years. METHODS: This study included 115 patients with DM1 at baseline (Time 1, T1) and at Time 2 (T2) who were questioned for daytime sleepiness, fatigue, history of depression, psychological distress, pain, hypothyroidism, and sleep habits. Also, their muscular impairment and intellectual quotient were evaluated. Regression models were used to identify correlates of daytime sleepiness and fatigue while controlling for time effect. RESULTS: Both daytime sleepiness and fatigue increased between T1 and T2, but their rate of change are higher when CTG repeat number is higher (p < 0.05). Also, higher psychological distress level is associated with higher daytime sleepiness and fatigue levels both at T1 and T2 (p < 0.01). Moreover, patients with a history of depression report higher daytime sleepiness levels both at T1 and T2 (p < 0.05). In addition, patients with higher fatigue levels both at T1 and T2 have more severe muscular impairment (p < 0.01) and report a longer habitual sleep duration (p < 0.05). Finally, a higher BMI and a history of hypothyroidism predict higher daytime sleepiness levels at T2 (p < 0.05). CONCLUSION: This study identified potentially modifiable risk factors of future daytime sleepiness and fatigue in DM1 patients, including BMI, psychological distress, hypothyroidism, and sleep habits.

Importance of Molecular Methods to Determine Whether a Probiotic is the Source of Lactobacillus Bacteremia.

There has been an increasing interest in the use of probiotic products for the prevention of Clostridium difficile infection (CDI). Bio-K+(®) is a commercial probiotic product comprising three strains of lactobacilli--Lactobacillus acidophilus CL1285(®), Lact. casei LBC80R(®) and Lact. rhamnosus CLR2(®)--that have been applied to prevent CDI. Generally considered as safe, lactobacilli have potential to cause bacteremia, endocarditis and other infections. The source of Lactobacillus bacteremia can be normal human flora or lactobacilli-containing probiotic. The aim of this study was to assess whether probiotic lactobacilli caused bacteremia and to show the value of molecular identification and typing techniques to determine probiotic and patient strain relatedness. We report an episode of Lactobacillus bacteremia in a 69-year-old man admitted to a hospital with severe congestive heart failure. During his hospitalization, he required long-term antibiotic therapy. Additionally, the patient received Bio-K+(®) probiotic as part of a quality improvement project to prevent CDI. Subsequently, Lactobacillus bacteremia occurred. Two independent blinded laboratory evaluations, using pulse field gel electrophoresis, 16S rRNA gene sequencing and DNA fingerprint analysis (rep-PCR), were performed to determine whether the recovered Lact. acidophilus originated from the probiotic product. Ultimately, the patient strain was identified as Lact. casei and both laboratories found no genetic relation between the patient's strain and any of the probiotic lactobacilli. This clinical case of lactobacillus bacteremia in the setting of probiotic exposure demonstrates the value of using discriminatory molecular methods to clearly determine whether there were a link between the patient's isolate and the probiotic strains.

A prospective study of the impact of child maltreatment and friend support on psychological distress trajectory: From adolescence to emerging adulthood.

BACKGROUND: Transition into adulthood is a critical developmental period that may be influenced by adverse life events as well as by protective factors. This study aimed at investigating the effect of different forms of child maltreatment experienced prior to age 14 (i.e., sexual abuse, physical abuse and exposure to intimate partner violence), and of friend support at age 14 on the psychological distress trajectory from age 14 to 24. METHODS: Participants were 605 adolescents from the general population involved in a 10-year longitudinal study. Psychological distress was evaluated at ages 14, 16, 18 and 24. Child maltreatment prior to 14 years was retrospectively assessed at 14 and 24 years while perception of support from friends was evaluated at age 14. RESULTS: Multilevel growth modeling indicated that psychological distress followed a significant decreasing curvilinear trajectory, with participants reporting fewer distressing psychological symptoms after 18 years. All three forms of child maltreatment, as well as their cumulative effect, predicted more psychological distress over 10 years above and beyond the protective effect of support from friends. Higher support from friends at age 14 was related to lower distress at baseline andover 10 years, beyond the effect of child maltreatment. LIMITATIONS: Self-report nature of all measures, attrition, and measures of child maltreatment forms. CONCLUSIONS: Psychological distress decreased during the transition from adolescence to emerging adulthood. Results also revealed the detrimental impact of child maltreatment and the promotive role of friend support, which underscore the importance of early intervention.

Development and aetiology of body dissatisfaction in adolescent boys and girls.

This longitudinal study aims to describe the development of body dissatisfaction (BD), measured with the Contour Drawing Rating Scale, between the ages of 14 and 18, and to identify factors associated with BD at age 18, among 413 adolescents. Between the ages of 14 and 18, the proportion of girls wanting to be thinner increased, although it remained unchanged among boys. A ratio of 1:2 girls and 1:5 boys reported having seriously tried to lose weight. Factors associated with BD in girls at age 18 were (1) wanting to be thinner, (2) body mass index (BMI), (3) weight control behaviours and (4) negative comments about weight. Factors associated with BD in boys at age 18 were (1) wanting to be thinner or bigger, (2) BMI, (3) having experienced sexual intercourse and (4) negative comments about weight. The high prevalence of BD and weight-related concerns suggest a need for early interventions.

Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): Characterization, Manufacture, Mechanisms of Action, and Quality Control of a Specific Probiotic Combination for Primary Prevention of Clostridium difficile Infection.

A specific probiotic formulation composed of Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+) has been marketed in North America since 1996. The strains and the commercial products have been evaluated for safety, identity, gastrointestinal survival, and stability throughout shelf life. The capacity of both the fermented beverages and the capsules to reduce incidences of antibiotic-associated diarrhea and Clostridium difficile infection (CDI) has been demonstrated in human clinical trials. Individual strains and the finished products have shown antimicrobial activity against C. difficile and toxin A/B neutralization capacity in vitro. The use of this specific probiotic formulation as part of a bundle of preventive measures to control CDI in healthcare settings is discussed.

Prefrontal tetanic stimulation, following fear reconditioning, facilitates expression of previously acquired extinction.

We have recently shown that post-extinction retraining of rats, with a shock intensity that is too weak to induce by itself significant fear acquisition, impairs the recall of fear extinction memory. Tetanic stimulation (TS) of the medial prefrontal cortex (mPFC), applied before or following this retraining, facilitates extinction recall. Here we investigated whether mPFC TS can also facilitate expression of fear extinction when rats are retrained with the same shock intensity as during the initial fear acquisition. Rats were implanted with stimulating electrodes in the mPFC and were trained to acquire freezing to a conditioning chamber, in which they had to enter freely. In Experiment 1, extinction of this response was followed by reconditioning and then another extinction training. Acquired freezing was extinguished successfully, while reacquired freezing, which was associated with increased chamber entry latencies, was resistant to subsequent extinction. Both reacquired freezing and increased chamber entry latencies were absent in rats that received post-reconditioning mPFC TS. In Experiment 2, post-conditioning mPFC TS had no effect on initially acquired freezing. In Experiment 3, rats were submitted to reconditioning without experiencing extinction training. In this condition, both reacquired freezing and increased chamber entry latencies were still present in rats that received post-reconditioning mPFC TS. These findings provide additional evidence for the fundamental role of the mPFC in maintaining expression of fear extinction.

Clinical, psychosocial, and central correlates of quality of life in myotonic dystrophy type 1 patients.

AIMS: To identify sociodemographic, clinical, and central correlates of health-related quality of life (HRQoL) in DM1 patients. METHODS: 200 DM1 patients had assessments of muscular impairment, CTG repeats, and intelligence. Validated instruments were used to assess sociodemographic and clinical factors as well as social support, social participation, daytime sleepiness, fatigue, personality, mood, and quality of life. Regression analysis was used to identify correlates of SF-36 physical and mental component summary scores. RESULTS: Patients scored lower on all SF-36 physical health subscales compared with normative data but did not differ with respect to mental health function. Regression analysis revealed that psychological distress, fatigue, severe muscular impairment, emotional stability, not having worked within the last 12 months, and lower intellectual quotient were associated with lower scores in physical health function. Moreover, neuroticism, daytime sleepiness, dissatisfaction with social participation, and lower conscientiousness were associated with lower scores in mental health function. CONCLUSION: DM1 has an impact on SF-36 physical summary scores but not on mental summary scores. Factors such as fatigue, daytime sleepiness, psychological distress, unemployment, and social participation dissatisfaction that significantly affect HRQoL in DM1 are amenable to treatment and psychosocial interventions, namely by providing care that integrate health, social, and community services.

A liquid chromatography - mass spectrometry method to measure ¹³C-isotope enrichment for DNA stable-isotope probing.

DNA stable-isotope probing (DNA-SIP) is a cultivation-independent technique that makes it possible to associate metabolic function and taxonomic identity in a wide range of terrestrial and aquatic environments. In DNA-SIP, DNA is labeled via the assimilation of a labeled growth substrate that is subsequently used to identify microorganisms involved in assimilation of the substrate. However, the labeling time has to be sufficient to obtain labeled DNA but not so long such that cross-feeding of ¹³C-labeled metabolites from the primary consumers to nontarget species can occur. Confirmation that the DNA is isotopically labeled in DNA-SIP assays can be achieved using an isotope ratio mass spectrometer. In this study, we describe the development of a method using liquid chromatography (HPLC) coupled to a quadrupole mass spectrometer (QMS) to measure the ¹³C enrichment of thymine incorporated into DNA in Escherichia coli cultures fed with [¹³C]acetate. The method involved the hydrolysis of DNA extracted from the cultures that released the nucleotides, followed by the separation of the thymine by HPLC on a reverse-phase C8 column in isocratic elution mode and the detection and quantification of ¹³C-labeled thymine by QMS. To mimic a DNA-SIP assay, a DNA mixture was made using ¹³C-labeled E. coli DNA with DNA extracted from five bacterial species. The HPLC-MS method was able to measure the correct proportion of ¹³C-DNA in the mix. This method can then be used as an alternative to the use of isotope ratio mass spectrometry in DNA-SIP assays.

Functional diversity in the denitrifying biofilm of the methanol-fed marine denitrification system at the Montreal Biodome.

Nitrate is a serious problem in closed-circuit public aquariums because its accumulation rapidly becomes toxic to many lifeforms. A moving bed biofilm denitrification reactor was installed at the Montreal Biodome to treat its 3,250-m(3) seawater system. Naturally occurring microorganisms from the seawater affluent colonized the reactor carriers to form a denitrifying biofilm. Here, we investigated the functional diversity of this biofilm by retrieving gene sequences related to narG, napA, nirK, nirS, cnorB, and nosZ. A total of 25 sequences related to these genes were retrieved from the biofilm. Among them, the corresponding napA1, nirK1, cnorB9, and nosZ3 sequences were identical to the corresponding genes found in Hyphomicrobium sp. NL23 while the narG1 and narG2 sequences were identical to the two corresponding narG genes found in Methylophaga sp. JAM1. These two bacterial strains were previously isolated from the denitrifying biofilm. To assess the abundance of denitrifiers and nitrate respirers in the biofilm, the gene copy number of all the narG, napA, nirS, and nirK sequences found in biofilm was determined by quantitative PCR. napA1, nirK1, narG1, and narG2, which were all associated with either Methylophaga sp. JAM1 or Hyphomicrobium sp. NL23, were the most abundant genes. The other genes were 10 to 10,000 times less abundant. nirK, cnorB, and nosZ but not napA transcripts from Hyphomicrobium sp. NL23 were detected in the biofilm, and only the narG1 transcripts from Methylophaga sp. JAM1 were detected in the biofilm. Among the 19 other genes, the transcripts of only two genes were detected in the biofilm. Our results show the predominance of Methylophaga sp. JAM1 and Hyphomicrobium sp. NL23 among the denitrifiers detected in the biofilm. The results suggest that Hyphomicrobium sp. NL23 could use the nitrite present in the biofilm generated by nitrate respirers such as Methylophaga sp. JAM1.

Risk factors for work-related fatigue in students with school-year employment.

PURPOSE: To explore potential risk factors for acute and chronic work-related fatigue in students working at a paid job while pursuing school studies. Although work-related fatigue was identified as a potential hazard for youth health, academic achievement, and occupational safety, very few studies have specifically addressed its correlates and possible predictors. METHODS: Cross-sectional data from an ongoing prospective cohort study of health risk behaviors in adolescents was used to identify factors associated with increased levels of acute and chronic fatigue in 209 students aged 17-18 years working during the school year. Multiple stepwise regression analyses were performed with acute and chronic fatigue levels as dependent variables, and demographic, work, and health factors as potential explanatory variables. RESULTS: Average hours worked per week by students was 14.7 hours. It was observed that higher psychological distress, poorer health perception, greater sleep debt, and higher exposure to physical work factors were associated with higher levels of acute fatigue. Also, it was observed that higher psychological distress, poorer health perception, higher exposure to physical work factors, and holding multiple jobs were associated with higher levels of chronic fatigue. The number of hours worked weekly was associated with neither acute nor chronic work-related fatigue. CONCLUSIONS: Findings suggest that prevention strategies devised to minimize work-related fatigue in students should consider exposure to physical work factors. Results also re-emphasize the importance of obtaining sufficient sleep so as to prevent high levels of acute work-related fatigue.

Dissimilatory reduction of nitrate in seawater by a Methylophaga strain containing two highly divergent narG sequences.

Methylophaga spp. are methylotrophs commonly associated with marine environments and have been defined as strict aerobic methylotrophs. They have been shown previously to represent 50-70% of the bacterial population in the biofilm of the methanol-fed denitrification reactor treating a large seawater aquarium at the Montreal Biodome. It was therefore surprising to find such a high concentration of Methylophaga spp. in anoxic conditions. In this study, we showed by cultivation-independent and -dependent approaches that one Methylophaga strain present in the anoxic biofilm is involved in the denitrification process. DNA stable-isotope probing (SIP) experiments in which the biofilm was cultured under denitrifying conditions with (13)C-methanol have revealed the enrichment of one particular taxon. By screening a 16S ribosomal RNA gene library derived from a (13)C-DNA fraction of the SIP gradients, 62% of the library was composed of one sequence affiliated with the genus Methylophaga. One strain, named JAM1, representing this Methylophaga species was isolated. It grows aerobically but also under denitrifying conditions by reducing nitrate into nitrite. The nitrate-reducing activity was correlated with the presence and the expression of two highly divergent narG genes (narG1 and narG2). narG1 showed a high percentage of identity with the corresponding part of narG found in Thiobacillus denitrificans, which suggests a recent acquisition of narG in strain JAM1 by horizontal gene transfer. This study provides the first direct evidence of the adaptation of a Methylophaga species to an oxygen-limited environment.

Psychosocial impact of predictive testing for myotonic dystrophy type 1.

In the Saguenay-Lac-Saint-Jean region (Quebec, Canada), a predictive DNA-testing program for myotonic dystrophy type 1 (DM1) has been available as a clinical service since 1988. From 1 to 12 years (median, 5 years) after receiving predictive testing, a total of 308 participants (44 carriers and 264 non-carriers) answered a questionnaire to determine the psychosocial impact of this genetic testing. The main reasons for wanting to be tested were to learn if children are at risk for DM1 or for reproductive decision making (75%) and to relieve the uncertainty for themselves (17%). The majority of participants (96.1%) remembered correctly their test result. At the time of the survey, the perception of the general well-being, the psychological distress (Psychiatric Symptom Index), and the self-esteem (Rosenberg Self-Esteem Scale) were similar in carriers, in non-carriers, and in the reference (Quebec) population. When participants indicated a change in different aspects of their lives following predictive testing, it was perceived as a change for the better by non-carriers and as a change for the worse by carriers. Nevertheless, for a majority of carriers and of non-carriers, the test result did not bring changes in their lives. All respondents believed that predictive testing should be available for the at-risk population and the vast majority of carrier and of non-carriers would recommend the use of predictive testing to their family members. Predictive testing for individuals at-risk of DM1 can be offered safely within a well-organized clinical and genetic counseling program that includes careful pre-test counseling, pre-test clinical assessment, post-test psychological support, and follow-up for those identified as carriers.