Potentials of leaves of Aspilia africana (Compositae) in wound care: an experimental evaluation

<p>Abstract</p> <p>Background</p> <p>The potentials of the leaves of the haemorrhage plant, <it>Aspilia africana </it>C. D Adams (Compositae) in wound care was evaluated using experimental models. <it>A. africana</it>, which is widespread in Africa, is used in traditional medicine to stop bleeding from wounds, clean the surfaces of sores, in the treatment of rheumatic pains, bee and scorpion stings and for removal of opacities and foreign bodies from the eyes. The present study was undertaken to evaluate the potentials for use of leaves of this plant in wound care.</p> <p>Methods</p> <p>The effect of the methanol extract (ME) and the hexane (HF) and methanol (MF) fractions (obtained by cold maceration and graded solvent extraction respectively) on bleeding/clotting time of fresh experimentally-induced wounds in rats, coagulation time of whole rat blood, growth of microbial wound contaminants and rate of healing of experimentally-induced wounds in rats were studied as well as the acute toxicity and lethality (LD₅₀) of the methanol extract and phytochemical analysis of the extract and fractions.</p> <p>Results</p> <p>The extract and fractions significantly (<it>P </it>< 0.05) reduced bleeding/clotting time in rats and decreased coagulation time of whole rat blood in order of magnitude of effect: MF>ME>HF. Also, the extract and fractions caused varying degrees of inhibition of the growth of clinical isolates of <it>Pseudomonas fluorescens </it>and <it>Staphylococcus aureus</it>, as well as typed strains of <it>Ps. aeruginosa </it>(ATCC 10145) and <it>Staph. aureus </it>(ATCC 12600), and reduced epithelialisation period of wounds experimentally-induced in rats. Acute toxicity and lethality (LD₅₀) test in mice established an i.p LD₅₀of 894 mg/kg for the methanol extract (ME). Phytochemical analysis revealed the presence of alkaloids, saponins, tannins, flavonoids, resins, sterols, terpenoids and carbohydrates.</p> <p>Conclusion</p> <p>The leaves of <it>A. africana </it>possess constituents capable of arresting wound bleeding, inhibiting the growth of microbial wound contaminants and accelerating wound healing which suggest good potentials for use in wound care.</p

The Influence of Markov Decision Process Structure on the Possible Strategic Use of Working Memory and Episodic Memory

Researchers use a variety of behavioral tasks to analyze the effect of biological manipulations on memory function. This research will benefit from a systematic mathematical method for analyzing memory demands in behavioral tasks. In the framework of reinforcement learning theory, these tasks can be mathematically described as partially-observable Markov decision processes. While a wealth of evidence collected over the past 15 years relates the basal ganglia to the reinforcement learning framework, only recently has much attention been paid to including psychological concepts such as working memory or episodic memory in these models. This paper presents an analysis that provides a quantitative description of memory states sufficient for correct choices at specific decision points. Using information from the mathematical structure of the task descriptions, we derive measures that indicate whether working memory (for one or more cues) or episodic memory can provide strategically useful information to an agent. In particular, the analysis determines which observed states must be maintained in or retrieved from memory to perform these specific tasks. We demonstrate the analysis on three simplified tasks as well as eight more complex memory tasks drawn from the animal and human literature (two alternation tasks, two sequence disambiguation tasks, two non-matching tasks, the 2-back task, and the 1-2-AX task). The results of these analyses agree with results from quantitative simulations of the task reported in previous publications and provide simple indications of the memory demands of the tasks which can require far less computation than a full simulation of the task. This may provide a basis for a quantitative behavioral stoichiometry of memory tasks

Differential response effects of data collection mode in a cancer screening study of unmarried women ages 40–75 years: A randomized trial

<p>Abstract</p> <p>Background</p> <p>Little is known about the impact of data collection method on self-reported cancer screening behaviours, particularly among hard-to-reach populations. The purpose of this study is to examine the effects of data collection mode on response to indicators of cancer screenings by unmarried middle-aged and older women.</p> <p>Methods</p> <p>Three survey methods were evaluated for collecting data about mammography and Papanicolaou (hereafter, Pap) testing among heterosexual and sexual minority (e.g., lesbian and bisexual) women. Women ages 40–75 were recruited from June 2003 – June 2005 in Rhode Island. They were randomly assigned to receive: Self-Administered Mailed Questionnaire [SAMQ; N = 202], Computer-Assisted Telephone Interview [CATI; N = 200], or Computer-Assisted Self-Interview [CASI; N = 197]. Logistic regression models were computed to assess survey mode differences for 13 self-reported items related to cancer screenings, adjusting for age, education, income, race, marital status, partner gender, and recruitment source.</p> <p>Results</p> <p>Compared to women assigned to CATI, women assigned to SAMQ were less likely to report two or more years between most recent mammograms (CATI = 23.2% vs. SAMQ = 17.7%; AOR = 0.5, 95% CI = 0.3 – 0.8) and women assigned to CASI were slightly less likely to report being overdue for mammography (CATI = 16.5% vs. CASI = 11.8%; AOR = 0.5, 95% CI = 0.3 – 1.0) and Pap testing (CATI = 14.9% vs. CASI = 10.0%; AOR = 0.5, 95% CI = 0.2 – 1.0). There were no other consistent mode effects.</p> <p>Conclusion</p> <p>Among participants in this sample, mode of data collection had little effect on the reporting of mammography and Pap testing behaviours. Other measures such as efficiency and cost-effectiveness of the mode should also be considered when determining the most appropriate form of data collection for use in monitoring indicators of cancer detection and control.</p

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Six-week high-intensity exercise program for middle-aged patients with knee osteoarthritis: a randomized controlled trial [ISRCTN20244858]

BACKGROUND: Studies on exercise in knee osteoarthritis (OA) have focused on elderly subjects. Subjects in this study were middle-aged with symptomatic and definite radiographic knee osteoarthritis. The aim was to test the effects of a short-term, high-intensity exercise program on self-reported pain, function and quality of life. METHODS: Patients aged 36–65, with OA grade III (Kellgren & Lawrence) were recruited. They had been referred for radiographic examination due to knee pain and had no history of major knee injury. They were randomized to a twice weekly supervised one hour exercise intervention for six weeks, or to a non-intervention control group. Exercise was performed at ≥ 60% of maximum heart rate (HR max). The primary outcome measure was the Knee injury and Osteoarthritis Outcome Score (KOOS). Follow-up occurred at 6 weeks and 6 months. RESULTS: Sixty-one subjects (mean age 56 (SD 6), 51 % women, mean BMI 29.5 (SD 4.8)) were randomly assigned to intervention (n = 30) or control group (n = 31). No significant differences in the KOOS subscales assessing pain, other symptoms, or function in daily life or in sport and recreation were seen at any time point between exercisers and controls. In the exercise group, an improvement was seen at 6 weeks in the KOOS subscale quality of life compared to the control group (mean change 4.0 vs. -0.7, p = 0.05). The difference between groups was still persistent at 6 months (p = 0.02). CONCLUSION: A six-week high-intensive exercise program had no effect on pain or function in middle-aged patients with moderate to severe radiographic knee OA. Some effect was seen on quality of life in the exercise group compared to the control group

Age-associated B cells predict impaired humoral immunity after COVID-19 vaccination in patients receiving immune checkpoint blockade

Age-associated B cells (ABC) accumulate with age and in individuals with different immunological disorders, including cancer patients treated with immune checkpoint blockade and those with inborn errors of immunity. Here, we investigate whether ABCs from different conditions are similar and how they impact the longitudinal level of the COVID-19 vaccine response. Single-cell RNA sequencing indicates that ABCs with distinct aetiologies have common transcriptional profiles and can be categorised according to their expression of immune genes, such as the autoimmune regulator (AIRE). Furthermore, higher baseline ABC frequency correlates with decreased levels of antigen-specific memory B cells and reduced neutralising capacity against SARS-CoV-2. ABCs express high levels of the inhibitory FcγRIIB receptor and are distinctive in their ability to bind immune complexes, which could contribute to diminish vaccine responses either directly, or indirectly via enhanced clearance of immune complexed-antigen. Expansion of ABCs may, therefore, serve as a biomarker identifying individuals at risk of suboptimal responses to vaccination

FAK/src-Family Dependent Activation of the Ste20-Like Kinase SLK Is Required for Microtubule-Dependent Focal Adhesion Turnover and Cell Migration

Cell migration involves a multitude of signals that converge on cytoskeletal reorganization, essential for development, immune responses and tissue repair. Using knockdown and dominant negative approaches, we show that the microtubule-associated Ste20-like kinase SLK is required for focal adhesion turnover and cell migration downstream of the FAK/c-src complex. Our results show that SLK co-localizes with paxillin, Rac1 and the microtubules at the leading edge of migrating cells and is activated by scratch wounding. SLK activation is dependent on FAK/c-src/MAPK signaling, whereas SLK recruitment to the leading edge is src-dependent but FAK independent. Our results show that SLK represents a novel focal adhesion disassembly signal

Staphylococcus aureus Induces Eosinophil Cell Death Mediated by α-hemolysin

Staphylococcus aureus, a major human pathogen, exacerbates allergic disorders, including atopic dermatitis, nasal polyps and asthma, which are characterized by tissue eosinophilia. Eosinophils, via their destructive granule contents, can cause significant tissue damage, resulting in inflammation and further recruitment of inflammatory cells. We hypothesised that the relationship between S. aureus and eosinophils may contribute to disease pathology. We found that supernatants from S. aureus (SH1000 strain) cultures cause rapid and profound eosinophil necrosis, resulting in dramatic cell loss within 2 hours. This is in marked contrast to neutrophil granulocytes where no significant cell death was observed (at equivalent dilutions). Supernatants prepared from a strain deficient in the accessory gene regulator (agr) that produces reduced levels of many important virulence factors, including the abundantly produced α-hemolysin (Hla), failed to induce eosinophil death. The role of Hla in mediating eosinophil death was investigated using both an Hla deficient SH1000-modified strain, which did not induce eosinophil death, and purified Hla, which induced concentration-dependent eosinophil death via both apoptosis and necrosis. We conclude that S. aureus Hla induces aberrant eosinophil cell death in vitro and that this may increase tissue injury in allergic disease