Follicular fluid leptin as a marker for pregnancy outcomes in women undergoing IVF treatment: a systematic review and meta-analysis.

Leptin is a hormone secreted mainly by the adipocytes with an essential role in the regulation of body weight. It acts on the reproductive axis at different sites, with stimulatory effects at the hypothalamus and pituitary and inhibitory interactions at the gonads. To investigate the influence of leptin on pregnancy outcomes in women undergoing IVF, we undertook a systematic review. A search of PubMed from 1966 to 2018 identified ten studies meeting the inclusion criteria. Outcomes were BMI, serum leptin level at hCG injection, serum and follicular fluid leptin level at the oocyte pick up, and serum 17ß-oestradiol level at oocyte pick up time, oocytes retrieved and embryo transfer number. Results indicated that follicular fluid leptin concentrations at the oocyte pick up were significantly lower in women who became pregnant compared to those who did not (MD = -4.53 (ng/ml); 95% CI: -7.78, -1.78; p value < 0.006). In conclusion, elevated leptin concentrations in follicular fluid at oocyte pick up time is significantly associated with an adverse pregnancy outcome in women undergoing an IVF programme.

Architectural anatomy of the quadriceps and the relationship with muscle strength: An observational study utilising real-time ultrasound in healthy adults.

Quadriceps atrophy and morphological change is a known phenomenon that can impact significantly on strength and functional performance in patients with acute or chronic presentations conditions. Real-time ultrasound (RTUS) imaging is a noninvasive valid and reliable method of quantifying quadriceps muscle anatomy and architecture. To date, there is a paucity of normative data on the architectural properties of superficial and deep components of the quadriceps muscle group to inform assessment and evaluation of intervention programs. The aims of this study were to (1) quantify the anatomical architectural properties of the quadriceps muscle group (rectus femoris, vastus intermedius, and vastus lateralis) using RTUS in healthy older adults and (2) to determine the relationship between RTUS muscle parameters and measures of quadriceps muscle strength. Thirty middle aged to older males and females (age range 55-79 years; mean age =59.9 ± 7.08 years) were recruited. Quadriceps muscle thickness, cross-sectional area, pennation angle, and echogenicity were measured using RTUS. Quadriceps strength was measured using hand-held dynamometry. For the RTUS-derived quadriceps morphological data, rectus femoris mean results; circumference 9.3 cm; CSA 4.6 cm2 ; thickness 1.5 cm; echogenicity 100.2 pixels. Vastus intermedius mean results; thickness 1.8 cm; echogenicity 99.1 pixels. Vastus lateralis thickness 1.9 cm; pennation angle 17.3°; fascicle length 7.0 cm. Quadriceps force was significantly correlated only with rectus femoris circumference (r = 0.48, p = 0.007), RF echogenicity (r = 0.38, p = 0.037), VI echogenicity (r = 0.43, p = 0.018), and VL fascicle length (r = 0.43, p = 0.019). Quadriceps force was best predicted by a three-variable model (adjusted R2  = 0.46, p < 0.001) which included rectus femoris echogenicity (B = 0.43, p = 0.005), vastus lateralis fascicle length (B = 0.33, p = 0.025) and rectus femoris circumference (B = 0.31, p = 0.041). Thus respectively, rectus femoris echogenicity explains 43%, vastus lateralis fascicle length explains 33% and rectus femoris circumference explains 31% of the variance of quadriceps force. The study findings suggest that RTUS measures were reliable and further research is warranted to establish whether these could be used as surrogate measures for quadriceps strength in adults to inform exercise and rehabilitation programs.

Effect of methionine feeding on oxidative stress, intracellular calcium and contractility in cardiomyocytes isolated from male and female rats.

Homocysteine (Hcy) is a breakdown product of methionine metabolism. The risk of cardiovascular disease (CVD) correlates with an increase in plasma Hcy levels. The aim of this study was to investigate whether 1% methionine supplementation of adult rats altered intracellular reactive oxygen species (ROS) generation, intracellular Ca2+ content, and contractile activity in freshly isolated cardiomyocytes. This was measured under normal conditions and during oxidative stress in freshly isolated cardiomyocytes. Single rat cardiomyocytes from both sexes were isolated by enzymatic and mechanical dispersion techniques. Fluorescence microscopy was used to measure ROS production and intracellular Ca2+ concentration. Cell contraction was measured using a video camera. During exposure to 200 µM, H2O2 female cardiomyocytes produced significantly fewer ROS and had a higher intracellular Ca2+ concentration compared to male cardiomyocytes in control and methionine-fed conditions. The contractility of cardiomyocytes isolated from male rats was insignificantly decreased after methionine feeding compared to control, while the contractility of cardiomyocytes from female rats insignificantly reduced after methionine feeding and acute exposure to oxidative stress. These findings provide evidence that during exposure to 200 µM H2O2, cardiomyocytes from female rats produce less ROS and have higher intracellular Ca2+ levels. There were no significant effects on contractility in cardiomyocytes from either gender and under any of the different conditions.

A low protein maternal diet during gestation has negative effects on male fertility markers in rats - A Systematic Review and Meta-analysis.

Research indicates that some adult diseases including reproductive pathologies are programmed in utero during foetal development. In particular, maternal low dietary protein, during the most critical developmental periods of male foetal development, may have a detrimental impact on male fertility through direct and epigenetic mechanisms. The aim of our study was to evaluate the impact of a gestational low protein diet on fertility markers in male offspring in rats through a systematic review and meta-analysis. A systematic search using PubMed, and EMBASE databases was performed and two investigators independently screened the 1,703 prospective articles. Eleven articles met the eligibility criteria. Outcome measures were pooled using random-effects models and expressed as mean differences (MDs) at 95% CIs for each study. The results reveal significant reduction in testis weight (MD (mean difference) -0.08 g; -0.12, -0.42; p = .0001), epididymal sperm count (MD -35.34 × 106 cells; -52.15, -18.53; p = .0001), number of Sertoli cells (MD -7.27 × 106 (-13.92, -0.62; p = .03), testosterone (T) concentration (MD -0.29 ng/ml; -0.48, -0.09; p = .004) and luteinising hormone (LH) concentration (MD of -0.24 ng/ml; -0.45, 0.04; p = .02) in comparison with controls. In contrast, follicle-stimulating hormone (FSH) concentration (MD of 0.07 ng/ml; -0.16, 0.29; p = .56) was not significantly different from controls. We conclude that low gestational dietary protein maternal intake potentially negatively impacts fertility in male progeny later in life. The mechanisms of action responsible for these phenomena remain unclear.

The effect of dietary protein intake on factors associated with male infertility: A systematic literature review and meta-analysis of animal clinical trials in rats.

BACKGROUND: Studies have shown that the amount of protein in the diet affects the hypothalamic-pituitary-testis axis and sub-optimal quantity reduces male fertility potential in both animals and humans. However, individual research reports on the factors associated with male infertility are collectively uncharacterized. AIM: We systematically reviewed, and meta-analysed animal (rats) studies on the effect of low protein diet on factors associated with male infertility. METHODS: PubMed Central, EMBASE and Scopus databases were searched from inception to 30 March 2019 for the study concepts and related keywords in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Data on the outcome measures were extracted and pooled across trials using random-effects model and expressed as mean differences (MD) at a 95% confidence interval (CI). RESULTS: Twelve trials identified from 3327 studies, met our inclusion criteria in the comparison of a low protein diet (2-10% protein) vs control protein diet (17-23% protein). The results showed that a low protein diet caused a significant reduction in the body weight (P = 0.0001) testis weight (P = 0.0001), seminal vesicle weight (P = 0.0003), epididymis weight P = 0.02), serum testosterone (P = 0.001) and follicle-stimulating hormone (FSH) concentrations (P = 0.04) compared with the control treatments. No effect on luteinizing hormone (LH) plasma concentration (P = 0.13) was observed. CONCLUSION: This study revealed that low protein diet caused significant reductions in body weight, testis, epididymis and seminal vesicle weights, serum testosterone and FSH concentration in rats. We infer that sub-optimal protein consumption reduces the gonadal and endocrine function, and consequently male infertility.

Effect of low- and high-protein maternal diets during gestation on reproductive outcomes in the rat: a systematic review and meta-analysis.

Studies with animal models have consistently demonstrated adverse health outcomes in offspring born following nutritional manipulation during gestation. However, the effects of gestational dietary protein modification on reproductive outcomes at birth are less clear. We, therefore, conducted a systematic review and meta-analysis of controlled trials to determine whether high- or low-protein diets are associated with altered reproductive outcomes in a commonly studied species, the rat. Included studies were identified through a systematic search using electronic databases and manual literature review to identify randomized studies published between June 1972 and March 2019. Thirty-two studies were identified and used to analyze the effects of low- and high-protein gestational diets on litter size, litter weight, gestational weight gain, and gestational feed intake. The results indicate that low-protein diets significantly reduced litter weight (P < 0.00001) and gestational weight gain (P < 0.0006), but did not influence litter size (P = 0.62) or gestational feed intake (P = 0.25). In contrast, high-protein diets were found to reduce gestational feed intake (P = 0.004) but did not influence litter size (P = 0.56), litter weight (P = 0.22), or gestational weight gain (P = 0.35). The results suggest that low but not high-protein gestational diets alter reproductive outcomes at birth in rats.

Pan-specific and partially selective dye-labeled peptidic inhibitors of the polycomb paralog proteins.

Epigenetic regulation of gene expression is in part controlled by post-translational modifications on histone proteins. Histone methylation is a key epigenetic mark that controls gene transcription and repression. There are five human polycomb paralog proteins (Cbx2/4/6/7/8) that use their chromodomains to recognize trimethylated lysine 27 on histone 3 (H3K27me3). Recognition of the methyllysine side chain is achieved through multiple cation-pi interactions within an 'aromatic cage' motif. Despite high structural similarity within the chromodomains of this protein family, they each have unique functional roles and are linked to different cancers. Selective inhibition of different CBX proteins is desirable for both fundamental studies and potential therapeutic applications. We report here on a series of peptidic inhibitors that target certain polycomb paralogs. We have identified peptidic scaffolds with sub-micromolar potency, and will report examples that are pan-specific and that are partially selective for individual members within the family. These results highlight important structure-activity relationships that allow for differential binding to be achieved through interactions outside of the methyllysine-binding aromatic cage motif.

Optimization of Ligands Using Focused DNA-Encoded Libraries To Develop a Selective, Cell-Permeable CBX8 Chromodomain Inhibitor.

Polycomb repressive complex 1 (PRC1) is critical for mediating gene expression during development. Five chromobox (CBX) homolog proteins, CBX2, CBX4, CBX6, CBX7, and CBX8, are incorporated into PRC1 complexes, where they mediate targeting to trimethylated lysine 27 of histone H3 (H3K27me3) via the N-terminal chromodomain (ChD). Individual CBX paralogs have been implicated as drug targets in cancer; however, high similarities in sequence and structure among the CBX ChDs provide a major obstacle in developing selective CBX ChD inhibitors. Here we report the selection of small, focused, DNA-encoded libraries (DELs) against multiple homologous ChDs to identify modifications to a parental ligand that confer both selectivity and potency for the ChD of CBX8. This on-DNA, medicinal chemistry approach enabled the development of SW2_110A, a selective, cell-permeable inhibitor of the CBX8 ChD. SW2_110A binds CBX8 ChD with a Kd of 800 nM, with minimal 5-fold selectivity for CBX8 ChD over all other CBX paralogs in vitro. SW2_110A specifically inhibits the association of CBX8 with chromatin in cells and inhibits the proliferation of THP1 leukemia cells driven by the MLL-AF9 translocation. In THP1 cells, SW2_110A treatment results in a significant decrease in the expression of MLL-AF9 target genes, including HOXA9, validating the previously established role for CBX8 in MLL-AF9 transcriptional activation, and defining the ChD as necessary for this function. The success of SW2_110A provides great promise for the development of highly selective and cell-permeable probes for the full CBX family. In addition, the approach taken provides a proof-of-principle demonstration of how DELs can be used iteratively for optimization of both ligand potency and selectivity.

Fingernail cortisol as a marker of chronic stress exposure in Indigenous and non-Indigenous young adults.

Cumulative exposure to stress over a long period can negatively impact an individual's health. Significant advancements in biomarkers of chronic stress have been made, with the use of fingernails recently explored. Cross sectional data from the Australian Aboriginal Birth Cohort (Indigenous) and Top End Cohort (non-Indigenous) were used to investigate the associations (sociodemographic and emotional) of fingernail cortisol in Indigenous and non-Indigenous young adults. Details on sociodemographic (age, gender, and Indigenous identification), smoking and alcohol use, emotional wellbeing, and emotional stress (perceived stress and stressful events), and fingernail samples were obtained face-to-face. Fingernail samples were analyzed for 179 Indigenous and 66 non-Indigenous participants (21-28 years). Indigenous participants were subjected to higher rates of stressful events compared to non-Indigenous (Median 6.0; interquartile range (IQR) 4, 9 vs. 1.0; IQR 0, 2; p < .001). Median cortisol levels were similar between Indigenous and non-Indigenous participants (4.36 pg/mg; IQR 2.2, 10.0 vs. 3.87 pg/mg: IQR 2.0, 9.7; p = .68). However, Indigenous participants had a higher cortisol level on adjustment for emotional distress and exposure to stressful events (Geometric Mean 1.82; 95CI: 1.07-3.09), with a negative association with increasing number of stressful events (Geometric Mean 0.94; 95CI 0.90, 0.99). Collection of fingernails was an easily conducted, well-tolerated method to measure stress markers in this multicultural cohort. Indigenous young adults experienced a high number of stressful events which was associated with a lowering of fingernail cortisol levels.Lay abstractChronic stress can impact negatively on health and emotional wellbeing. A fingernail sample provided a culturally acceptable, noninvasive method of measuring chronic stress in Indigenous and non-Indigenous young adults. Cortisol levels, a marker of chronic stress, were different between Indigenous and non-Indigenous young adults and were influenced by emotional status and occurrence of multiple stressful events.

Accelerated Structural Prediction of Flexible Protein-Ligand Complexes: The SLICE Method.

Using existing and academically available software, we present a new method for the structural prediction of binding events containing flexible protein targets. SLICE (Selective Ligand-Induced Conformational Ensemble) combines opportunistic stochastic jumps of ligand position with standard molecular dynamics to model the induced-fit binding of ligands starting with unbound host coordinates. To induce the structural adaptations of the complex at the binding site, conformational jumps in ligand position are selected in SLICE from structures generated by a docking software. Multiple binding trajectories from the docking set are followed using molecular dynamics for a set time to relax the host structure and generate new host poses. A new configurational jump is made on the set of newly generated host poses. The process is then repeated. The method was implemented with AutoDock Vina as the docking method, Vina scores as the selection criterion, and Amber code for molecular dynamics and applied to several test systems. A system consisting of Chromobox protein homologue 8 (CBX8) and its small peptide ligand, H3K9Me3, for which the final (bound) configuration is known, is used for verifying SLICE in the present setup. The setup was also applied to several nonpeptide molecules on known difficult flexible targets exhibiting a large disparity between apo and holo host states. The SLICE simulations provide a promising approach to generate induced-fit configurations compared to existing long (microsecond) classical and accelerated dynamics approaches in all the test systems considered here. However, further optimization of SLICE parameters is required for replicating crystal structure coordinates for some systems. We discuss in the following pages the various SLICE parameters and how they can be optimized for the system at hand.

Hair cortisol and cortisone as markers of stress in Indigenous and non-Indigenous young adults.

Chronic, ongoing stress can impact negatively on health and wellbeing. Indigenous Australians are at an increased risk of experiencing multiple stressors. Hair glucocorticoids have been used as a marker for chronic stress. This study aimed to assess the associations of hair cortisol and cortisone with sociodemographic (age, gender, Indigenous Identification), substance use, emotional wellbeing, and emotional stress, in a cohort at increased risk of stressful events and psychological distress. Cross-sectional data (age 21-28 years) are presented from two Australian longitudinal studies; the Aboriginal Birth Cohort (n = 253) and non-Indigenous Top End Cohort (n = 72). A third of the cohort reported psychological distress, with Indigenous participants reporting higher rates of stressful events compared to non-Indigenous (6 vs. 1; p < .001). Significantly higher levels of cortisone were seen in Indigenous women compared to non-Indigenous women (ß 0.21; p = .003). A positive association with age was present in hair cortisol and cortisone in Indigenous young adults (ß 0.29 and ß 0.41; p < .001, respectively). No association with substance use, emotional wellbeing or emotional stress was seen. Sub-analysis in women suggested a possible curvilinear relationship between hair cortisone and the number of stressful events. In this culturally diverse cohort, hair sampling provides a noninvasive, easily conducted and generally well tolerated mechanism to measure stress markers. The association with age, even in this narrow age range, likely represents the manifold changes in circumstances (financial independence, becoming parents, increased risk of substance use and mental illness) that occur during this transitional period of life, particularly for young Indigenous women. LAY ABSTRACT Chronic stress can impact negatively on health and emotional wellbeing. A hair sample is an easy way to measure chronic stress in Indigenous and non-Indigenous young people. The markers of chronic stress, cortisol and cortisone, were different between Indigenous and non-Indigenous, men and women and increased with age in Indigenous young adults.

Blood pressure measurements in research: suitability of auscultatory, beat-to-beat, and ambulatory blood pressure measurements.

OBJECTIVE: The objective of this study was to validate the accuracy of beat-to-beat measurements with those taken with an aneroid sphygmomanometer by auscultatory method. A secondary aim was to explore differences between auscultatory and beat-to-beat blood pressure (BP) with daytime ambulatory BP measurements. PARTICIPANTS AND METHODS: A total of 46 participants, comprising 21 males, aged 47±13 years, height 171±8.5 cm and weight 82±16.8 kg attended the Exercise Physiology Laboratory at the University of New England (Armidale, New South Wales, Australia). During the visit, participants had their BP - systolic BP (SBP) and diastolic BP (DBP) - measured using auscultatory methods and a Finometer. An ambulatory BP monitor was fitted during the same visit and worn for a minimum of 12 h. RESULTS: Auscultatory measurements were slightly higher than beat-to-beat for both SBP and DBP. There was no difference between auscultatory and beat-to-beat SBP with a mean difference of 0.23 mmHg (P=0.87). There were disparities between auscultatory and beat-to-beat DBP, with a mean difference of 4.82 mmHg (P<0.01). Daytime ambulatory BP was higher than both auscultatory and beat-to-beat measurements for both SBP and DBP, with P less than 0.001 for all measures. CONCLUSION: There was a high level of reliability in the beat-to-beat SBP with that seen by auscultatory; however, there were disparities in DBP measurements using the same devices, which raise concerns over the accuracy of beat-to-beat DBP. Ambulatory systolic and diastolic measures were higher than beat-to-beat and auscultatory; however, they may be more suitable for monitoring diurnal changes in BP, depending upon the research model.

Hormonal changes, semen quality and variance in reproductive activity outcomes of post pubertal rabbits fed Moringa oleifera Lam. leaf powder.

ETHNOPHARMACOLOGICAL RELEVANCE: Moringa oleifera Lam. (Moringaceae) is an important plant based staple food, known for its nutritional and medicinal value and is usually prescribed by herbal practitioners in Nigeria and in other tropical countries for the treatment of male infertility problems and reproductive diseases in females. Although the aphrodisiac properties and fertility enhancement potential in males have been reported, the underlying mechanisms for the activity remain unclear. In this study, we investigated the influence of supplementing the diet with M. oleifera Lam. leaf powder on reproductive hormones and semen quality of New Zealand White (NZW) rabbits. MATERIALS AND METHODS: Thirty-two (32) NZW rabbits of 50:50 ratio bucks to does, were randomly distributed to four treatment groups (n = 4 bucks, n = 4 does per group). Graded levels (0, 5, 10 and 15 g/kg) of M. oleifera Lam. leaf powder was incorporated into rabbit growers pellet. The does and bucks were housed separately in hutches and sheltered under the same environmental conditions with free access to their respective treatment diets for a period of 12 weeks. RESULTS: In female rabbits, treatment revealed significant (P < 0.05) dose-dependent reduction in the concentration of serum FSH, LH and oestrogen. While in contrast the highest dose of leaf powder significantly (P < 0.05) increased progesterone and prolactin concentrations remained unaffected. On the other hand, the concentration of FSH and LH in bucks was significantly (P < 0.05) increased in treatment groups compared to the control group. Serum testosterone concentrations were significantly lower in the 5 and 10 g/kg treatment groups. Semen volume, sperm count and motility were significantly improved in a dose dependent manner with increasing amounts of M. oleifera Lam. leaf powder in the diet. CONCLUSIONS: We conclude that M. oleifera Lam. leaf powder supplementation to the diet was more beneficial to male rabbit fertility than the female, where it tended to have a negative impact through the hypothalamic-pituitary-gonadal axis. However, with the varying impact of M. oleifera Lam. leaf powder on the hypothalamic-pituitary-gonadal axis of male and female animals, further investigation is necessary to determine the mechanism through which it operates.

Diagnostic utility of an age-specific cut-off for d-dimer for pulmonary embolism assessment when used with various pulmonary embolism risk scores.

This retrospective cohort study compared the diagnostic utility (sensitivity, specificity and negative predictive value (NPV)) of the age-times-10 adjusted d-dimer cut-off used in combination with the original and simplified Well's pulmonary embolism (PE) scores and the original and simplified revised Geneva scores to identify patients in whom PE is classified as unlikely according to each score. The PE risk scores performed similarly with high sensitivity (97.6, 97.1, 96.9 and 97.1% respectively) and NPV (99.3, 99.3, 99.2 and 99.2% respectively). Each missed only one PE. The age-times-10 age-adjusted d-dimer assay cut-off performed similarly with each of the clinical risk scores tested with high sensitivity and NPV.

Can the sensitivity of the histopathological diagnosis of coeliac disease be increased and can treatment progression be monitored using mathematical modelling of histological sections? - A pilot study.

PURPOSE: The aim of this pilot study was to attempt to define a set of equations from histological observations of tissue affected with coeliac disease (CD) to predict Marsh score. MATERIAL/METHODS: Tissue from 15 patients with untreated CD, 6 patients with treated CD and 9 healthy control patients were stained using the standard H&E, Giemsa's staining for tissue sections and Alcian Blue protocols. A number of histological measures were then taken from each section and the data was used to ultimately design a set of linear predictive algorithms to calculate Marsh score. RESULTS: Using MANOVA and discriminant analysis, two linear functions were defined which could accurately predict the Marsh score of patients 62.5% (full Marsh score) to 79.2% (simplified Marsh score) of the time. CONCLUSIONS: This pilot study has shown that a set of objective histological measures can be used to define algorithms to predict Marsh score in CD patients and also monitor treatment compliance and progression.

Leptin pharmacokinetics in male mice.

Pharmacokinetics of leptin in mammals has not been studied in detail and only one study has examined more than one time point in non-mutant mice and this was in a female mice. This is the first study to describe leptin distribution over a detailed time course in normal male mice. A physiologic dose (12 ng) of radiolabelled leptin was injected into adult male mice via the lateral tail vein and tissues were dissected out and measured for radioactivity over a time course of up to two hours. Major targets were the digestive tract, kidneys, skin and lungs. The brain was not a major target, and 0.15% of the total dose was recovered from the brain 5 min after administration. Major differences appear to exist in the distribution of leptin between the male and female mice, indicating a high degree of sexual dimorphism. Although the half-lives were similar between male and female mice, almost twice the proportion of leptin was recovered from the digestive tract of male mice in comparison to that reported previously for females. This would seem to indicate a major difference in leptin distribution and possibly function between males and females.

The efficacy of isometric resistance training utilizing handgrip exercise for blood pressure management: A randomized trial.

INTRODUCTION: Hypertension is a major risk factor contributing to cardiovascular disease, which is the number one cause of deaths worldwide. Although antihypertensive medications are effective at controlling blood pressure, current first-line treatment for hypertension is nonpharmacological lifestyle modifications. Recent studies indicate that isometric resistance training (IRT) may also be effective for assisting with blood pressure management. The aim of this study was to determine the efficacy of IRT for blood pressure management and the suitability of a low-intensity working control group. METHODS: Forty hypertensive individuals, aged between 36 and 65 years, conducted IRT for 8 weeks. Participants were randomized into 2 groups, working at an intensity of either 5% or 30% of their maximum voluntary contraction. Participants performed 4 × 2 minute isometric handgrip exercises with their nondominant hand, each separated by a 3-minute rest period, 3 days a week. RESULTS: Blood pressure measurements were conducted at baseline and at the end of the protocol using a Finometer. Eight weeks of isometric resistance training resulted in a 7-mmHg reduction of resting systolic blood pressure (SBP) (136 ±â€Š12 to 129 ±â€Š15; P = 0.04) in the 30% group. Reductions of 4 mmHg were also seen in mean arterial pressure (MAP) (100 ±â€Š8 to 96 ±â€Š11; P = 0.04) in the 30% group. There were no statistically significant reductions in diastolic blood pressure for the 30% group, or any of the data for the 5% group. CONCLUSION: Isometric resistance training conducted using handgrip exercise at 30% of maximum voluntary contraction significantly reduced SBP and MAP. A lack of reduction in blood pressure in the 5% group indicates that a low-intensity group may be suitable as a working control for future studies.

The relationship between positive psychological characteristics and longer telomeres.

OBJECTIVE: Longer telomeres are associated with better health and longevity. This research investigated the relationship between positive psychological dispositional traits and telomere length. Positive traits examined were typical high positive affect, typical low negative affect, life satisfaction, trait mindfulness, trait emotional intelligence, general self-efficacy and optimism. DESIGN AND MEASURES: One hundred and twenty women and men, with a mean age of 40.92, completed measures of positive characteristics and provided samples for telomere length analysis. RESULTS: Together the positive dispositional characteristics explained significant variance in telomere length, R = .40. Among the individual characteristics, greater optimism and higher emotional intelligence were associated with longer telomeres after adjustment for age and gender and the association between optimism and telomere length remained significant after adjusting for age and gender as well as the other positive characteristics, with a partial correlation r of .30. CONCLUSION: These results in conjunction with previous research findings provide a platform for further exploration of biological pathways connecting positive characteristics such as optimism to telomere length and investigation of the impact of increasing a characteristic such as optimism on telomere functioning.