Function In Cohort Research Articles

Coenzyme Q10 supplementation and diastolic heart functions in hemodialysis patients: A randomized double‐blind placebo‐controlled trial

Coenzyme Q10 (CoQ10) supplementation has been shown to improve diastolic heart function in various patient cohorts. Systolic and diastolic dysfunctions are common in patients with end-stage renal disease. Favorable effects of CoQ10 on cardiac functions are yet to be seen in hemodialysis patients. We aimed to evaluate effect of CoQ10 supplementation on diastolic function in a cohort of maintenance hemodialysis patients. This was a prospective, double-blind, placebo-controlled, crossover study in which all patients received placebo and oral CoQ10 200 mg/d during the 8 weeks in each phase, with a 4-week washout period. Participants underwent conventional and tissue Doppler echocardiography before and after each study phase. Parameters characterizing left ventricle diastolic function and other standard echocardiographic measurements were recorded. Twenty-eight patients were randomized, but 22 patients completed study protocol. Intraventricular septum (IVS) thickness and left ventricle mass were significantly decreased in CoQ10 group (P = 0.03 and P = 0.01, respectively). Myocardial peak systolic and early diastolic velocities derived from IVS were significantly increased (P = 0.048 and P = 0.04, respectively). Isovolumetric relaxation time and E/Em ratio calculated for IVS also significantly reduced in CoQ10 group (p = 0.02 and p = 0.04, respectively). There was no significant difference in any of the studied echocardiographic parameters in placebo group. The results of this study showed that CoQ10 supplementation did not significantly improved diastolic heart functions compared with placebo in maintenance hemodialysis patients.

Bariatric surgery-mediated weight loss and its metabolic consequences for type-2 diabetes

The worldwide epidemic of obesity and its medical complications are being dealt with a combination of life style changes (e.g., healthier diet and exercise), medications and a variety of surgical interventions. The Roux-en Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) are two of the most common weight loss surgeries for morbid obesity-associated metabolic syndrome and insulin resistance. A vast majority of patients that undergo RYGB and LAGB are known to experience marked weight loss and attenuation of diabetes. A number of recent studies have indicated that the rates of remission in glycemic control and insulin sensitivity are significantly greater in patients that have undergone RYGB. A plausible hypothesis to explain this observation is that the gastric bypass surgery as opposed to the gastric banding procedure impinges on glucose homeostasis by a weight loss-independent mechanism. In a recent paper, Bradley et al have experimentally explored this hypothesis. The authors compared several clinical and laboratory parameters of insulin sensitivity and β-cell function in cohorts of RYGB and LAGB patients before and after they lost approximately 20% of their body mass. After weight loss, both groups of patients underwent similar changes in their intra-abdominal and total adipose tissue volume, hepatic triglyceride and circulating leptin levels. The RYGB patients who lost 20% body mass, manifested higher postprandial output of glucose, insulin and glucagon-like peptide-1; these laboratory parameters remained unchanged in LABG patients. Irrespective of the observed differences in transient responses of RYGB and LAGB patients to mixed meal, the overall glycemic control as judged by glucose tolerance, multi-organ insulin sensitivity and β-cell function were nearly identical in the two groups. Both RYGB and LAGB patient cohorts also experienced similar changes in the expression of a number of pro- and anti-inflammatory markers. Based on these analyses, Bradley et al concluded that similar restoration of insulin sensitivity and b-cell function in non-diabetic obese patients that have undergone RYGB and LAGB were directly due to marked weight loss. These data have important implications for the risk/benefit analysis of weight loss therapy by bariatric procedures.

Changes in the prevalence of child sexual abuse, its risk factors, and their associations as a function of age cohort in a Finnish population sample

Objective We examined (1) the prevalence of childhood sexual abuse (CSA) experiences as a function of cohort and gender, (2) the prevalence of factors associated with CSA as a function of cohort and whether the association of these factors with CSA remained the same irrespective of cohort, and (3) whether any cohort differences could be explainable by cohort differences in reporting bias. Method We used the responses of 4,561 men ( M = 29, SD = 7 years) and 8,361 female ( M = 29, SD = 7 years) Finnish participants who responded to the Childhood Trauma Questionnaire-Short Form as well as questions regarding family structure. Results The prevalence of CSA experiences varied between 0.7–4.6% for men and 1.8–7.5% for women depending on the item. Younger cohorts reported less CSA as well as less of the risk factors (physical neglect and abuse, emotional neglect and abuse, parental substances abuse, not growing up with both biological parents) that were positively associated with the likelihood of CSA. The effects of these risk factors did not vary as a function of the cohort. Also, the declining trend was not explainable by social desirability being higher in the younger cohorts. Conclusions The results suggest that there is a real decline in the prevalence of CSA and it is associated with a simultaneous decline in factors associated with CSA.

CT Metrics of Airway Disease and Emphysema in Severe COPD

CT scan measures of emphysema and airway disease have been correlated with lung function in cohorts of subjects with a range of COPD severity. The contribution of CT scan-assessed airway disease to objective measures of lung function and respiratory symptoms such as dyspnea in severe emphysema is less clear. Using data from 338 subjects in the National Emphysema Treatment Trial (NETT) Genetics Ancillary Study, densitometric measures of emphysema using a threshold of -950 Hounsfield units (%LAA-950) and airway wall phenotypes of the wall thickness (WT) and the square root of wall area (SRWA) of a 10-mm luminal perimeter airway were calculated for each subject. Linear regression analysis was performed for outcome variables FEV(1) and percent predicted value of FEV(1) with CT scan measures of emphysema and airway disease. In univariate analysis, there were significant negative correlations between %LAA-950 and both the WT (r = -0.28, p = 0.0001) and SRWA (r = -0.19, p = 0.0008). Airway wall thickness was weakly but significantly correlated with postbronchodilator FEV(1)% predicted (R = -0.12, p = 0.02). Multivariate analysis showed significant associations between either WT or SRWA (beta = -5.2, p = 0.009; beta = -2.6, p = 0.008, respectively) and %LAA-950 (beta = -10.6, p = 0.03) with the postbronchodilator FEV(1)% predicted. Male subjects exhibited significantly thicker airway wall phenotypes (p = 0.007 for WT and p = 0.0006 for SRWA). Airway disease and emphysema detected by CT scanning are inversely related in patients with severe COPD. Airway wall phenotypes were influenced by gender and associated with lung function in subjects with severe emphysema.

Bactericidal activity of neutrophils with reduced oxidative burst from adults with bronchiectasis

Recent work has shown that the most common abnormality on screening of immune function in cohort of adult subjects with bronchiectasis was a low neutrophil oxidative burst. To assess the functional significance of a low oxidative burst in subjects with idiopathic bronchiectasis. Neutrophils with a low oxidative burst were obtained from six bronchiectasis patients and assessed for their ability to kill Staphylococcus aureus. The results were compared with those obtained using neutrophils from 12 healthy controls subjects and control neutrophils treated with dimethylthiourea (DMTU), an inhibitor of the oxidative burst. The results showed that the bronchiectasis subjects had significantly reduced killing of bacteria compared with controls (p<0.001). The addition of DMTU to neutrophils of control subjects significantly impaired both the oxidative burst and bactericidal activity. The addition of interferon-gamma enhanced oxidative burst in both groups. Abnormal neutrophil function in some subjects with bronchiectasis may account for their high rate of infection.

Characterization of ion channel and transporter mRNA expressions in isolated gill chloride and pavement cells of seawater acclimating eels

Ion channels and transporters (i.e. cystic fibrosis transmembrane regulator (CFTR), inward rectifier potassium channel (eKir), Na/K-ATPase, Na/K/Cl 2 co-transporter (NKCC), aquaporin-3 (AQP-3), and Na/H exchanger-1 (NHE-1)) are known to be expressed in gill epithelia of teleost fish. Owing to the anatomical complexity of gill structures, their temporal expression profile in seawater acclimating gill pavement (PVCs) and chloride cells (CCs) are limited. In this study, we isolated the gill PVCs and CCs from seawater acclimating Japanese eels to address the issue. In the gill epithelia of freshwater adapted eels, CCs expressed the highest mRNA and/or protein levels of Na/K-ATPase, NKCC, and eKir as demonstrated by real-time PCR and/or immunohistochemical staining. AQP-3 mRNA was highly expressed in freshwater PVCs and its protein was in general expressed in all gill cells. The NHE-1 transcripts were expressed in similar levels in both PVCs and CCs. CFTR mRNA transcript was almost undetectable in all the freshwater gill cell samples. Seawater acclimation induced the transcript and/or protein levels of Na/K-ATPase, NKCC, CFTR, and eKir in CCs. The upregulation and the coexpression of these transporters in CCs suggested their cohort function in mediating Na +, K +, and Cl − transport. The expression of CFTR was found to be tightly regulated as its expression was restricted only in “seawater CCs”. AQP-3 transcript and protein levels in PVCs reduced significantly during the acclimation. Interestingly immunocytochemical (ICC) staining of seawater gill epithelia revealed that AQP-3 immunoreactivities were mainly localized in seawater CCs. In the acclimation, there was no significant reduction of NHE-1 mRNA in both PVCs and CCs, however its protein level dropped significantly in the seawater condition. The present study is the first to demonstrate the activation of the mRNA transcripts for the ion channels and transporters in isolated gill CCs during seawater acclimation. The activating mechanism is found to be confined primarily in CCs. These results indicated that in addition to the increase in size and number of CCs, the molecular remodeling and the functional plasticity of CCs were essential in the ion transport process during seawater acclimation.

β Subunits of Voltage-gated Sodium Channels Are Novel Substrates of β-Site Amyloid Precursor Protein-cleaving Enzyme (BACE1) and γ-Secretase

Sequential processing of amyloid precursor protein (APP) by membrane-bound proteases, BACE1 and gamma-secretase, plays a crucial role in the pathogenesis of Alzheimer disease. Much has been discovered on the properties of these proteases; however, regulatory mechanisms of enzyme-substrate interaction in neurons and their involvement in pathological changes are still not fully understood. It is mainly because of the membrane-associated cleavage of these proteases and the lack of information on new substrates processed in a similar way to APP. Here, using RNA interference-mediated BACE1 knockdown, mouse embryonic fibroblasts that are deficient in either BACE1 or presenilins, and BACE1-deficient mouse brain, we show clear evidence that beta subunits of voltage-gated sodium channels are sequentially processed by BACE1 and gamma-secretase. These results may provide new insights into the underlying pathology of Alzheimer disease.

Key Factors in the Development of Asthma: Atopy

One approach to unraveling the role of the multiple risk factors that contribute to the development of asthma is to track the process in cohorts of children from birth until age(s) at which the disease manifests. In relation to atopy, this involves the prospective and cross-sectional study of allergen-specific T cell function in cohorts of children, focusing particularly on responses to the major inhalant allergens that have been identified as asthma triggers in later life. The key issues in this context are ( 1 ) what factor(s) are responsible for the polarization of allergen-specific helper T cell memory toward the atopyassociated helper T cell type 2 (Th2) cytokine phenotype, and ( 2 ) why does the development of this form of helper T cell memory lead to the development of asthma in some but not all individuals with atopic asthma.

Quality of life: Perceptions of residential care

Byrne H & MacLean D. International Journal of Nursing Practice 1997; 3: 21–28 Quality of life: Perceptions of residential care Residents in selected aged care facilities in Australia (n=185) and New Zealand (n=44) completed a 56 item quality of life instrument derived and refined through grounded theory. Ten scales were developed from the items. Analysis of variance (ANOVA) indicated that there were no main differences as a function of cohort (Alzheimer’s or non-Alzheimer’s) or country of residence (Australia or New Zealand). Significant differences emerged as a function of the source of help in completing the instrument. Where nursing staff assisted residents complete the instrument, scoring indicated that residents enjoyed a better quality of life than if the instrument was completed by the resident alone, or with assistance from non-nursing staff and others, including relatives, welfare students and diversional therapists. Nursing staff rather than non-professional nursing staff tended to work more with non-Alzheimer residents when completing the questionnaire. Significant differences were also discovered in the ranking of concerns on the basis of cohort and country of residence.

Quality of life: Perceptions of residential care

Residents in selected aged care facilities in Australia (n = 185) and New Zealand (n = 44) completed a 56 item quality of life instrument derived and refined through grounded theory. Ten scales were developed from the items. Analysis of variance (ANOVA) indicated that there were no main differences as a function of cohort (Alzheimer's or non-Alzheimer's) or country of residence (Australia or New Zealand). Significant differences emerged as a function of the source of help in completing the instrument. Where nursing staff assisted residents complete the instrument, scoring indicated that residents enjoyed a better quality of life than if the instrument was completed by the resident alone, or with assistance from non-nursing staff and others, including relatives, welfare students and diversional therapists. Nursing staff rather than non-professional nursing staff tended to work more with non-Alzheimer residents when completing the questionnaire. Significant differences were also discovered in the ranking of concerns on the basis of cohort and country of residence.

Adolescent sexual behavior.

What is known about adolescent sexual behavior is reviewed. First, the onset of sexual behavior in the teenage years is considered as a function of cohort, gender, and ethnic differences. Omissions in the research on sexual behavior other than intercourse are highlighted. Possible biological, social, and social cognitive processes underlying teenage sexual behavior are then considered. Next, demographic trends in the use of contraceptives and antecedents of regular birth control use are reviewed. Finally, some of the successful program initiatives directed toward altering sexual and contraceptive practices are discussed, keeping in mind the importance and relative lack of well-designed and carefully evaluated programs.