Association Between Heart Rate Resting State Entropy and Heart Rate Dynamics Among Healthy Adults and Patients with Aortic Stenosis

Introduction: Aortic Stenosis (AS) is a cardiovascular disease that restricts the blood flow from the left ventricle to the aorta and leads to a decline in physical activities in people with such conditions. Heart rate (HR) complexity has been implemented as a standard method to assess cardiac autonomic dysfunction in cardiovascular diseases. The HR complexity is derived from the electrocardiogram (ECG) signals while the participant rests for a minimum of five minutes. The focus of this study is to compare the HR complexity during a 5-minute resting period and the HR dynamics, which is a novel approach to measure HR changes during a 20-second physical activity among healthy young adults and older adults with AS.Methods: Healthy young adults (controls) aged 18-30 years and older adults (>60 years) with AS were recruited for this study. HR complexity was assessed by asking the participants to sit still with no interaction or movement, and HR was recorded for 5 minutes. HR dynamics were assessed when participants performed a physical task (20 seconds baseline, 20 seconds of rapid elbow flexion with the right arm, and 30 seconds recovery). HR was recorded using an ECG sensor attached to the left side of the chest and upper rib. The multiscale entropy (MSE) method with a selected scale factor of 20 was used to measure complexity during the 20 seconds physical task using time series of intervals between the heartbeats. HR dynamics parameters included percent change in HR during the activity and the recovery period after the arm flexion task. ANOVA models were used with the groups, age, BMI, and sex as independent and HR dynamics and the MSE values as dependent variables. Pearson correlations between MSE and HR dynamics were calculated. Results & Discussion: A total of 70 participants were recruited for this study, including 30 healthy controls (age=21±6 years) and 40 AS patients (age=71±11 years). There was a significant difference between HR dynamics (HR increase and decrease) between controls and AS patients, mean values of 41.46% and 15.70% for HR increase (p=0.0055) and mean values of -27.04% and -13.15% for HR decrease (p=0.0007), for controls and AS patients, respectively. The Pearson correlation between the HR dynamics and the MSE data among the two groups combined showed significant associations. Results suggest that the proposed HR dynamics can provide a quicker measure of autonomic control deficits in AS. Significance: Current findings suggest that HR outcomes obtained from a quick 20s test during physical activity can provide information on cardiac autonomic dysfunction in AS patients. AS is mainly associated with an increased risk of frailty in older adults. Frailty is a syndrome associated with low physiological reserve, which leads to muscle loss and autonomic dysfunction. Currently, there is no specific device or assessment tool available to detect frailty in AS patients. Hence, our current findings suggest that the HR dynamics outcomes obtained could provide information for assessing frailty in AS. For future investigations, we will develop an easy-to-use app on a smartwatch for identifying frailty with the use of simultaneous measures of HR dynamics and motor performance

the role of head teacher supervision

Thesis(Master) --KDI School:Master of Development Policy,2014masterpublishedBOHAM, Joyce Ewura Adwoa

Isolation and antioxidant activity of 5-methyldihydroflavasperone from ethanol leaf extract of Guiera senegalensis JF Gmel

BACKGROUND: Guiera senegalensis (Ghibaish) is a medicinal plant extensively used in central and west Africa for the management of various diseases. AIM: This study aimed to determine the antioxidant activity of the ethanol leaf extract of the plant. METHOD: The ethanol leaf extract was sequentially sub-fractionated using liquid–liquid extraction, vacuum-liquid chromatography and preparative thin layer chromatography. Ultraperformance liquid chromatography with accurate mass spectrometry and nuclear magnetic resonance were employed to isolate and confirm the identity of the most abundant compound. The antioxidant activity of the fractions and isolated compound was assessed by bioautography analysis and the 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) radical scavenging assay. RESULTS: The dichloromethane subfraction contained the most promising antioxidant activity (IC50 = 3.18 µg/mL). Purification of this subfraction led to the isolation of a brown crystalline compound, which was identified as 5-methyldihydroflavasperone (IC50 > 4000 µg/mL). CONCLUSION: This is the first report of the isolation of 5-methyldihydroflavasperone from the ethanol leaf extracts of G. senegalensis. This compound was not found to be responsible for the antioxidant activity observed. Further research is warranted to identify the compound responsible for the antioxidant activity.The Sudan Ministry of Higher Education in the form of a scholarship to undertake this study.https://jomped.org/index.php/jompedChemistryPharmacolog

The effect of three Ghanaian plants on fibroblast migration, inflammation and bacterial growth in vitro

Medical conditions which cause morbidity and mortality, such as chronic wounds and infection, lead to significant medical costs. Much of the world's population is dependent on alternative medicine, of which herbal medicine forms a crucial part. In Ghana and other countries around the world, an estimated 70% of the population rely on alternative treatments like herbs for management of various forms of disease. However, even though medicinal plants are widely used for treatment, most have not been scientifically proven to be safe and efficacious. Hence there is need to assess the biological activity of these plants which may be a potential lead in drug development. This study assessed the wound-related biological activities of three commonly used medicinal plants in Ghana (Aspilia africana, Boerhavia diffusa, and Erythrina senegalensis). Sequential extracts were prepared from the three plants using hexane, ethyl acetate, methanol, and water as solvents, in increasing polarity. Also, ethnomedicinal extracts were obtained with water as solvent, in accordance with the method used by traditional healers. Extracts were screened for phytochemical components using thin layer chromatography (TLC), and phytochemical fingerprinting performed with ultra performance liquid chromatography in tandem with time-of-flight mass spectrometry (UPLC-qTOF-MS). Cytotoxic potential of the extracts in SC-1 fibroblasts, C2C12-myoblasts, and differentiated THP-1-macrophages was determined using the sulforhodamine B staining assay, and cells morphologically assessed with phase contrast, PlasDIC, and live/dead staining microscopy. Acellular antioxidant activity was conducted by exploring the 2,2'-azino-bis[3-ethylbenzothiazoline-6-sulphonic acid] (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, whilst ability to protect against cellular oxidative stress was assessed using 2',7'-dichlorofluorescin diacetate as marker. Anti-inflammatory potential of extracts was evaluated using xanthine oxidase activity. Also, the ability of extracts to alter closure of artificially generated wounds in fibroblast and myoblast monocultures was determined using the scratch assay. The extracts were also assessed for their antibacterial effect using the disk diffusion and microdilution assays. Extracts with a minimum inhibitory concentration (MIC) above or equal to 1 mg/mL were evaluated for their ability to inhibit bacterial biofilms. Analysis using TLC indicated that alkaloids, flavonoids, and phenols were the major groups present. The UPLC-qTOF-MS analysis led to the verification of previously identified, as well as tentative identification of already-described phytochemical compounds or their derivatives in the plants. In addition to the already reported ascorbic acid, quercetin was also identified in A. africana. Furthermore, kaempferol, quercetin, and rutin were identified in the extracts of B. diffusa, the latter compound being identified for the first time in this plant. Also, for the first time, kaempferol, rotenone and rutin, were identified in extracts of E. senegalensis. Apart from these three compounds, neobavaisoflavone was also detected. All the extracts recorded a half maximal inhibitory concentration (IC50) above 100 _g/mL in all three cell-lines. The most cytotoxic extracts to the myoblasts, fibroblasts, and macrophages, were the methanol and ethnomedicinal extracts of A. africana, and the hexane extract of E. senegalensis, with a maximum of 38.8% reduction in cell density respectively. The minimal cytotoxic potential of the extracts was further confirmed by the absence of morphological differences between treated and untreated cells. Most of the extracts exhibited good ABTS radical scavenging activity (IC50 < 100 _g/mL). The strongest effect against the free radical was observed with the ethyl acetate extract of B. diffusa (IC50 = 21.23 _g/mL). On the contrary, most of the extracts recorded poor ability to scavenge the DPPH free radical. Only the methanol extracts of A. africana (IC50 = 278 _g/mL) and E. senegalensis (IC50 = 291 _g/mL) yielded IC50 values below the maximum tested concentration (320 _g/mL). This could possibly be ascribed to the differences in the stereoselectivity between the two free radicals, and the poor DPPH scavenging ability of hydrophilic antioxidants. The effect of the extracts against AAPH-induced oxidation in the cells correlated with the antioxidant potential of the extracts. Whilst most of the extracts with good antioxidant potential suppressed AAPH-induced oxidative stress, the most profound effect was observed with pre-treatment of macrophages with the ethyl acetate extract of A. africana. The extract caused a 1.74-fold decrease in intracellular reactive oxygen species (ROS) concentration after 120 min following pre-treatment with 100 _g/mL, when compared with the AAPH control. This was comparable to the 1.89-fold reduction caused by the positive control compound, 5 _g/mL Trolox. The ethnomedicinal extracts of B. diffusa and E. senegalensis exhibited a dose-dependent increase in intracellular ROS in fibroblasts, with intracellular ROS concentration upon treatment with the extracts at 100 _g/mL being at least 23% higher than the negative controls. This suggest that the extracts could exhibit a possible pro-oxidant effect at higher concentrations. Quercetin, a compound with pro-oxidant effects at higher concentrations, was detected in the ethyl acetate extract of B. diffusa, which may describe this effect. However, none of the extracts used in the current study demonstrated the ability to significantly inhibit xanthine oxidase activity. The strongest activity against the enzyme (maximum of 15% inhibition) was exhibited by extracts of E. senegalensis. The hexane extract of A. africana and the water extracts of B. diffusa increased migration of myoblast cells by 44.4% and 39.4%, respectively. This indicates a possible role of the extracts in enhancing collagen deposition and wound remodelling, two processes with myoblast involvement. On the other hand, six of the extracts decreased fibroblast migration, and therefore could have negative effects on wound healing processes such as collagen and matrix metalloproteinase synthesis. Further analysis would be required to ascertain the extent to which the extracts could impact activity of the cells. Also, the methanol extract of E. senegalensis (MIC = 0.5 mg/mL in E. coli) was the most effective against the micro-organisms tested. All the other extracts had MICs above 1 mg/mL. None of the extracts showed activity against Pseudomonas aeruginosa, Staphylococcus epidermidis and bacterial biofilms. In conclusion, this study has scientifically demonstrated that the three plants may assist wound healing at different stages in the healing process. This could be achieved through their antioxidant effects, ability to suppress oxidative stress, antibacterial activity, and ability to enhance activity of fibroblasts and myoblasts. Practitioners should be cautioned against using high concentrations because of possible cytotoxicity.Thesis (PhD)--University of Pretoria, 2018.PharmacologyPhDUnrestricte

Wpływ społecznej odpowiedzialności przedsiębiorstw (CSR) na atrakcyjność pracy, zaangażowanie pracowników i retencję pracowników. Na przykładzie Ghany.

Ta praca magisterska prezentuje ocenę wpływu społecznej odpowiedzialności przedsiębiorstw (CSR) na atrakcyjność pracy, zaangażowanie pracowników i retencję w Ghanie. Badanie skupia się na pięciu firmach, które aktywnie prowadzą działania CSR w różnych branżach. Badanie przyjmuje podejście ilościowe i obejmuje próbkę 160 pracowników tych firm.Oprócz zbierania pierwotnych danych, badanie uwzględnia dane wtórne w postaci raportów i publikacji mediów oraz stron informacyjnych firm. Analiza wykazuje, że najczęstszymi obszarami priorytetowymi działań CSR w badanych organizacjach są edukacja i zdrowie.Wnioski wskazują na pozytywną zależność między wewnętrznym CSR a retencją pracowników, potwierdzając, że wewnętrzne działania CSR pozytywnie wpływają na decyzję pracowników o pozostaniu w organizacji. Podobnie badanie ujawnia pozytywny związek między CSR a zaangażowaniem pracowników, co oznacza, że inicjatywy CSR wzmacniają oddanie pracowników wobec pracy. Ponadto badanie wykazuje pozytywny związek między CSR a atrakcyjnością pracy. Badanie ujawnia również, że praktyki CSR i postrzeganie pracowników nie różnią się istotnie w zależności od branży firmy.Wnioski dostarczają cennych spostrzeżeń i podkreślają znaczenie zarówno wewnętrznych, jak i zewnętrznych inicjatyw CSR dla osiągnięcia pozytywnych rezultatów pracowniczych. Te wnioski mają praktyczne implikacje dla organizacji w Ghanie i przyczyniają się do istniejącego dorobku wiedzy na temat CSR i jego wpływu na zachowanie pracowników oraz sukces organizacyjny.This thesis presents an evaluation of the impact of Corporate Social Responsibility (CSR) on employees' attraction to a job, their commitment, and retention in Ghana. The study focuses on five companies heavy on CSR and operating in different industries. The research adopts a quantitative approach, to sample 160 employees from these companies.In addition to primary data collection, the study incorporates secondary data in the form of reports and publications from media houses and the companies' news pages. The analysis reveals that the most common priority focus areas for CSR practices among the sampled organizations are education and health. The findings indicate a positive relationship between internal CSR and employee retention, affirming that internal CSR practices positively influence employees' decision to stay with the organization. Similarly, the study reveals a positive relationship between CSR and employee commitment, implying that CSR initiatives enhance employees' dedication to their work. Moreover, the research demonstrates a positive relationship between CSR and job attractiveness. The study also reveals that CSR practices and employee perception do not vary significantly based on the industry of the company.The findings provide valuable insights and highlight the importance of both internal and external CSR initiatives in fostering positive employee outcomes. These findings have practical implications for organizations in Ghana and contribute to the existing body of knowledge on CSR and its effects on employee behavior and organizational success

African Herbal Remedies with Antioxidant Activity: A Potential Resource Base for Wound Treatment

The use of traditional herbal remedies as alternative medicine plays an important role in Africa since it forms part of primary health care for treatment of various medical conditions, including wounds. Although physiological levels of free radicals are essential to the healing process, they are known to partly contribute to wound chronicity when in excess. Consequently, antioxidant therapy has been shown to facilitate healing of such wounds. Also, a growing body of evidence suggests that, at least, part of the therapeutic value of herbals may be explained by their antioxidant activity. This paper reviews African herbal remedies with antioxidant activity with the aim of indicating potential resources for wound treatment. Firstly, herbals with identified antioxidant compounds and, secondly, herbals with proven antioxidant activity, but where the compound(s) responsible for the activity has not yet been identified, are listed. In the latter case it has been attempted to ascribe the activity to a compound known to be present in the plant family and/or species, where related activity has previously been documented for another genus of the species. Also, the tests employed to assess antioxidant activity and the potential caveats thereof during assessment are briefly commented on

Effect of ethnomedicinal extracts used for wound healing on cellular migration and intracellular reactive oxygen species release in SC-1 fibroblasts

The inhibition of reactive oxygen species (ROS) and the migration of fibroblasts are key processes involved in wound healing. In this study, the ability of aqueous ethnomedicinal plant extracts prepared from Aspilia africana CD Adams, Boerhavia diffusa L. and Erythrina senegalensis DC. to mediate fibroblast migration and ROS release was determined. Phytochemical composition was assessed using thin-layer chromatography (TLC), whereas phytochemical markers were detected using ultra-performance liquid chromatography coupled to time of flight mass spectrometry (UPLC-TOF-MS). Sulforhodamine B staining and morphological examination via microscopy was conducted to determine cytotoxic effects on SC-1 fibroblasts. The effect on AAPH-induced oxidative stress was assessed by measuring ROS release using dichlorofluorescein diacetate activation. The scratch wound assay was used to estimate the rate of cellular migration. Alkaloids, flavonoids and phenols were detected in all three extracts using TLC, whilst UPLC-TOF-MS revealed the presence of neobavaisoflavone in E. senegalensis. None of the extracts was cytotoxic to the SC-1 cells at the highest in-well concentration tested (100 μg/mL). E. senegalensis extract reduced intracellular ROS and cellular migration by 35% and 32.5%, respectively. Although these plant extracts have the potential to minimise oxidation, they do not facilitate fibroblast migration. Further investigation into their mechanism of wound healing is required.The National Research Foundation of South Africa (NRF-TWAS grant number 100000 , 2016).http://www.elsevier.com/locate/sajb2019-09-01hj2018Pharmacolog

The role of tryptophan derivatives as anti-kinetoplastid agents

Kinetoplastids are the causative agents for a spectrum of vector-borne diseases including Leishmaniasis, Chagas disease and Trypanosomiasis that affect millions of people worldwide. In the absence of safe and effective vaccines, chemotherapy, in conjunction with vector control, remain the most significant control approach for kinetoplastid diseases. However, commercially available treatment for these neglected tropical diseases frequently ends up with toxic side effects and increasing resistance. To meet the rising need for innovative medications, alternative chemotherapeutic agents are required. Moreover, insights into target-based mode of action of chemotherapeutic agents are required if novel drugs that may outwit resistance to commercially available drugs are to be developed. Tryptophan has been implicated in a variety of diseases and disorders due to its fundamental role as a precursor to several bioactive metabolites, as well as its importance in the improvement of health and nutrition, diagnostics, and therapeutics. The regulation of tryptophan metabolism plays a fundamental role in the growth of kinetoplastids. Moreover, the levels of tryptophan may serve as a biomarker to distinguish between the stages of kinetoplastids making it an important amino acid to explore for drug targets. The main aim of this review is thus to provide a comprehensive literature synthesis of tryptophan derivatives to explore as potential anti-kinetoplastids. Here we highlight the role of tryptophan derivatives as chemotherapeutic agents against kinetoplastids. The reviewed compounds provide insights into potential new drug interventions that may combat the increasing problem of anti-kinetoplastid resistance

Turning up the volume for precision herbal medicine in Africa in an era of COVID-19 and planetary biodiversity loss

CITATION: Thomford, N. E. et al. 2020. Turning up the volume for precision herbal medicine in Africa in an era of COVID-19 and planetary biodiversity loss. OMICS, 24, doi:10.1089/omi.2020.0150.The original publication is available at https://www.liebertpub.comWhat would it take in terms of the structural reforms in science, technology, and culture to cultivate sustainable therapeutic and preventive medicine innovations against zoonotic infections such as coronavirus disease 2019 (COVID-19) in the 21st century? In May 2019, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services warned that “around one million animal and plant species are now threatened with extinction.” Biodiversity is essential for drug discovery and development. We are currently facing a dual challenge in therapeutics innovation with COVID-19 and loss in planetary biodiversity. Hence, there is an urgent need for new ideas and strategies for drug discovery as well as repurposed drugs for the COVID-19 pandemic. To these ends, the existing scholarship in, and the field of precision herbal medicine provide an alternative source for discovery of novel therapeutics against the novel coronavirus. We propose that the application of precision herbal medicine in Africa could usefully contribute to current efforts for therapeutics innovation for the COVID-19 pandemic, and beyond. The pandemic calls for interdisciplinary dialogue and turning up the volume for precision herbal medicine in Africa, and importantly, in ways informed by robust systems science as well as broad public engagement to codesign medicines in the 21st century.National Research Foundation (NRF)https://www.liebertpub.com/doi/full/10.1089/omi.2020.0150Pre-prin