Cation-exchange solid-phase and liquid-liquid extraction for the determination of khat alkaloids by reversed phase HPLC-DAD

Leaves of khat (Catha edulis) are masticated to elicit their psycho-stimulating properties, resulting from the presence of the phenylpropylamino alkaloids. The determination of these alkaloids is important in pharmacological, phytochemical, forensic and law enforcement environments. In this study, the use of strong cation exchange-solid phase extraction (SCX-SPE) was investigated as an alternative means of sample purification prior to the determination of cathinone, cathine and norephedrine by reversed phase (C18) high performance liquid chromatography (HPLC). Extraction parameters for SCX, including loading capacity and washing solvents, were established. An existing liquid-liquid extraction (LLE) method was improved in terms of recoveries obtained, by using ethyl acetate as extractant. For pure standards of the khat alkaloids, recoveries ranged from 83 to 97%. Preconcentration, using a Genevac evaporator after the addition of acidified water to the sample, restricted analyte losses when compared to concentration under nitrogen. Although comparable recoveries were obtained when preconcentration was achieved in the presence of acidified water by rotary evaporation, this method is not suitable for large sample numbers. Best recoveries, ranging from 94 to 102%, were obtained by SCX from spiked samples. Although the extraction efficiencies of LLE were lower (87-90%), LLE yielded less complex chromatograms, indicating a purer extract. KEY WORDS: Khat alkaloids, Solid phase extraction, Liquid-liquid extraction, HPLC, Genevac Bull. Chem. Soc. Ethiop. 2015, 29(3), 331-339.DOI: http://dx.doi.org/10.4314/bcse.v29i3.

Assessment of the concentration of Cr, Mn and Fe in sediment using laser-induced breakdown spectroscopy

In the present study, laser-induced breakdown spectroscopy (LIBS) has been applied for the determination of levels of Cr, Mn and Fe in sediment samples and the results have been compared with that of flame-atomic absorption spectroscopy (F-AAS). Fourteen sediment samples were collected from Tinishu Akaki River (TAR), Addis Ababa, Ethiopia. Pellets of 24 mm in diameter and 3-5 mm in thickness were prepared using a manual hydraulic press under a pressure of 8000 psi by mixing finely ground sediment samples with boric acid. The concentrations of Cr, Mn and Fe were successfully determined by Q-switched Nd:YAG laser at 1064 nm. Quantification of these metals was conducted against certified reference materials of sediments and soils. The LIBS results for the elements varied from 0.060–0.707 mg/g for Cr, 0.895–3.64 mg/g for Mn and 26.9–71.8 mg/g for Fe. The F-AAS results varied from 0.061–1.37 mg/g for Cr, 1.24–4.46 mg/g for Mn and 49.0–83.3 mg/g for Fe. TAR was found to be heavily polluted with Cr. KEY WORDS: Laser-induced breakdown spectroscopy, Chromium, Manganese, Iron, Sediment, Tinishu Akaki River, Ethiopia Bull. Chem. Soc. Ethiop. 2013, 27(1), 1-13.DOI: http://dx.doi.org/10.4314/bcse.v27i1.

Self-reflection and academic performance: is there a relationship?

The purposes of the present study were two-fold: first, to evaluate whether reflection journal writing was effective in promoting self-reflection and learning, and whether students become better at self-reflection if they engage continuously in reflection journal writing. To that end, the reflection journals of 690 first-year applied science students at a local polytechnic were studied by means of an automated coding procedures using software. Data was collected twice, once at the beginning and again towards the end of an academic year. Outcomes of the textual content analyses revealed that students reflected on both the process and contents of their learning: critical review of past learning experiences, learning strategies and summaries of what was learned. Correlational analyses showed weak to moderate inter-relationship

Stabilization and reversal of child obesity in Andalusia using objective anthropometric measures by socioeconomic status

Background: Childhood obesity continues to be a significant public health issue worldwide. Recent national studies in Spain show a stable picture. However, prevalence and trends differ by socio-economic status, age, and region. We present the trend in childhood excess weight prevalence, aged 8–15 years, in Andalusia from 2011-2012 to 2015–2016 by socio-economic status. Results: Overall prevalence of excess weight decreased from 42.0% in 2011–2012 to 35.4% in 2015–2016. Overweight decreased from 28.2 to 24.2% and obesity from 13.8 to 11.2%. In 2011–2012 the prevalence of excess weight in boys was 46.0%and 37.9% in girls; in 2015–2016 the difference became significant with 41% of boys with excess weight compared with 30% in girls. Conclusions: Childhood excess weight prevalence in Andalusia has decreased slightly between 2011-2012 and 2015–2016. Notably, a decrease in obesity prevalence in girls aged 8–15 years was recorded. In 2011–2012 a social gradient for excess weight prevalence across three SES indicators was observed: in 2015–2016 this gradient disappeared. Nonetheless, prevalence remains too high

Motivational Interviewing as an intervention to increase adolescent self-efficacy and promote weight loss: Methodology and design

<p>Abstract</p> <p>Background</p> <p>Childhood obesity is associated with serious physiological and psychological consequences including type 2 diabetes, higher rates of depression and low self-esteem. With the population of overweight and obese youth increasing, appropriate interventions are needed that speak to the issue of readiness to change and motivation to maintain adherence to healthy behavior changes. Motivational Interviewing (MI) is a method of therapy found to resolve ambivalence, enhance intrinsic motivation and promote confidence in a person's ability to make behavior changes. While MI has shown promise in the adult obesity literature as effecting positive lifestyle change, little is known about the effectiveness of MI with overweight and obese youth. This study aims to: 1) demonstrate that MI is an effective intervention for increasing a person's self-efficacy; 2) demonstrate that exposure to MI will facilitate healthy behavior changes; 3) explore psychological changes related to participation in MI and 4) compare physiological and anthropometric outcomes before and after intervention.</p> <p>Methods/Design</p> <p>The current investigation is a prospective study conducted with ongoing participants who regularly attend an outpatient pediatric care center for weight-loss. Overweight youth (BMI > 85^th%ile) between the ages of 10 and 18 who meet eligibility criteria will be recruited. Participants will be randomly assigned to a control group (social skills training) or a treatment group (MI). Participants will meet with the therapist for approximately 30 minutes prior to seeing the dietician, over the course of 6 months. Participants will also undergo a full day assessment at the beginning and end of psychology intervention to evaluate body fat, and metabolic risk (screening for diabetes, high cholesterol, high blood pressure and fitness level). The paper and pencil portions of the assessments as well as the clinical testing will occur at baseline and at the conclusion of the intervention (6 months) with a repeat assessment 6 months following the completion of the intervention.</p> <p>Discussion</p> <p>Results from this study are expected to enhance our understanding of the efficacy of MI with children and adolescents who are overweight or obese.</p> <p>Trial registration</p> <p>Current Controlled Trials #<a href="http://www.clinicaltrials.gov/ct2/show/NCT00326404">NCT00326404</a>.</p

Effect of garlic on blood pressure: A systematic review and meta-analysis

The electronic version of this article is the complete one and can be found online at the publisher's website.Background: Non-pharmacological treatment options for hypertension have the potential to reduce the risk of cardiovascular disease at a population level. Animal studies have suggested that garlic reduces blood pressure, but primary studies in humans and non-systematic reviews have reported mixed results. With interest in complementary medicine for hypertension increasing, it is timely to update a systematic review and meta-analysis from 1994 of studies investigating the effect of garlic preparations on blood pressure. Methods: We searched the Medline and Embase databases for studies published between 1955 and October 2007. Randomised controlled trials with true placebo groups, using garlic-only preparations, and reporting mean systolic and/or diastolic blood pressure (SBP/DBP) and standard deviations were included in the meta-analysis. We also conducted subgroup meta-analysis by baseline blood pressure (hypertensive/normotensive), for the first time. Meta-regression analysis was performed to test the associations between blood pressure outcomes and duration of treatment, dosage, and blood pressure at start of treatment. Results: Eleven of 25 studies included in the systematic review were suitable for meta-analysis. Meta-analysis of all studies showed a mean decrease of 4.6 ± 2.8 mm Hg for SBP in the garlic group compared to placebo (n = 10; p = 0.001), while the mean decrease in the hypertensive subgroup was 8.4 ± 2.8 mm Hg for SBP (n = 4; p < 0.001), and 7.3 ± 1.5 mm Hg for DBP (n = 3; p < 0.001). Regression analysis revealed a significant association between blood pressure at the start of the intervention and the level of blood pressure reduction (SBP: R = 0.057; p = 0.03; DBP: R = -0.315; p = 0.02). Conclusion: Our meta-analysis suggests that garlic preparations are superior to placebo in reducing blood pressure in individuals with hypertension.Karin Ried, Oliver R. Frank, Nigel P. Stocks, Peter Fakler and Thomas Sulliva

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8–13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05–6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50–75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life. Funding Pfizer, Amgen, Merck Sharp & Dohme, Sanofi–Aventis, Daiichi Sankyo, and Regeneron

Intelligent Identification of Childhood Musical Murmurs

Heart murmurs are often the first signs of heart valvular disorders. However, most heart murmurs detected in children are innocent musical murmurs (also called Still's murmurs), which should be distinguished from other murmur types that are mostly pathological, such as regurgitant, obstructive, and flow murmurs. In order to reduce both unnecessary healthcare expenditures and parental anxiety, this study aims to develop algorithms for intelligently identifying musical murmurs in children. Discrete wavelet transform was applied to phonocardiographic signals to extract features. Singular value decomposition was applied on the matrix derived from continuous wavelet transform to extract extra features. The sequential forward feature selection algorithm was then utilized to select significant features. Musical murmurs were subsequently differentiated via a classification procedure consisting of three classification techniques: discriminant analysis, support vector machine, and artificial neural network. The results of 89.02% sensitivity, 84.76% specificity and 87.36% classification accuracy were achieved

Association between sleep duration and blood pressure in adolescents

In adults, sleep has an important role in the development of cardiovascular diseases. However, in young adolescents, the effect is unclear. The purpose of this cross-sectional study was to evaluate the association between sleep duration and blood pressure (BP) in subjects of 13 years of age. We evaluated 1771 adolescents as part of a population-based cohort (Epidemiological Health Investigation of Teenagers). Sleep duration was estimated based on the difference between self-reported usual bedtimes and wake-up times, and adolescents were classified into three categories: 8.5 h (reference class), >8.5 h and 8.5 and <9.5 h: OR=1.56, 95% CI 1.07–2.27; 9.5 h: OR=1.83, 95% CI 1.23–2.70). Among males, no significant association was found between sleep duration and BP. Sleep duration was positively associated with BP in both sexes, although after adjustment for potential confounders, this association was significant only for female adolescents

Ischaemic conditioning and targeting reperfusion injury: a 30 year voyage of discovery

To commemorate the auspicious occasion of the 30th anniversary of IPC, leading pioneers in the field of cardioprotection gathered in Barcelona in May 2016 to review and discuss the history of IPC, its evolution to IPost and RIC, myocardial reperfusion injury as a therapeutic target, and future targets and strategies for cardioprotection. This article provides an overview of the major topics discussed at this special meeting and underscores the huge importance and impact, the discovery of IPC has made in the field of cardiovascular research