293 research outputs found
GAS CHROMATOGRAPHY-MASS SPECTROMETRY ANALYSIS AND ANTIOXIDANT ACTIVITY OF PUNICA GRANATUM L. PEELS AND ITS ROLE AS IMMUNOSTIMULANT AGAINST SCHISTOSOMA MANSONI INFECTION IN BIOMPHALARIA ALEXANDRINA
Objective: To evaluate the antioxidant activity and chemical composition of Punica granatum L. and test it as immunostimulants against Schistosoma mansoni infection to Biomphalaria alexandrina snails.Methods: Antioxidant activity was evaluated by measuring the free radical scavenging activity of the 90% defatted methanol extract (90% DM) of P. granatum peels and its sub-derived fractions was evaluated via 2,2'-diphenyl-1-picrylhydrazyl and its chemical constituents were identified via gas chromatography-mass spectrometry (GC-MS) analysis. B. alexandrina snails were exposed to pomegranate extracts (PEs) for 1 month before their challenging with S. mansoni miracidia. Infection rates, immunological and histological parameters were, then, evaluated in PE-exposed snails and compared to controls.Results: The antioxidants activities of PE, expressed as scavenging concentration at 50%, were in the following order; 90% DM (12.45) ĂÆn-butanol(15.59) ĂÆethyl acetate (21.36) ĂÆwater (49.16) Ă”g/ml, compared to 7.50 Ă”g/ml for ascorbic acid. The infection rates of PE-exposed snails were 20%,50%, 60%, 70%, and 80%, respectively, for 90% DM, n-butanol, ethyl acetate, water, and dichloromethane extracts compared to 95% in control snails. The number of amoebocytes showed a significant increase, clear differentiation, and size increment in exposed snails compared to controls. Moreover, hermaphrodite glands histology shows a full maturity in the formation of reproductive cells in PE-exposed snails. The GC-MS analysis of the 90% DM extract revealed the presence of 36 compounds representing 93.1% of the total composition. Piperidin-4-ol, 1,3-dimethyl-2,4,6-triphenyl (19.87%), and 6,11-dihydroxy-5,12 naphthacenequinone-1-carboxylic acid (7.80%) were the major components.Conclusion: The identified compounds in 90% DM extract of P. granatum may be responsible for the high antioxidant activity of the fruit and it may account for its immunostimulatory effect against S. mansoni infection in B. alexandrina.Keywords: Punica granatum L., Antioxidant activity, Biomphalaria alexandrina, Schistosoma mansoni, Infection rate, Gas chromatography-mass spectrometry
Facial cellulitis revealing choreo-acanthocytosis: A case report
We report a 62 year-old-man with facial cellulitis revealing choreo-acanthocytosis (ChAc). He showed chorea that started 20 years ago. The orofacial dyskinisia with tongue and cheek biting resulted in facial cellulitis. The peripheral blood smear revealed acanthocytosis of 25%. The overall of chorea, orofacial dyskinetic disorder, peripheral neuropathy, disturbed behavior, acanthocytosis and the atrophy of caudate nuclei was suggestive of a diagnosis of ChAc. To our knowledge no similar cases of facial cellulitis revealing choreo-acanthocytosis (ChAc) were found in a review of the literature.Key words: Choreo-acanthocytosis, facial cellulitis, dyskinetic movement
FMRF-NH2-related neuropeptides in Biomphalaria spp., intermediate hosts for schistosomiasis: Precursor organization and immunohistochemical localization
Freshwater snails of the genus Biomphalaria serve as intermediate hosts for the digenetic trematode Schistosoma mansoni, the etiological agent for the most widespread form of intestinal schistosomiasis. As neuropeptide signaling in host snails can be altered by trematode infection, a neural transcriptomics approach was undertaken to identify peptide precursors in Biomphalaria glabrata, the major intermediate host for S. mansoni in the Western Hemisphere. Three transcripts that encode peptides belonging to the FMRF-NH2-related peptide (FaRP) family were identified in B. glabrata. One transcript encoded a precursor polypeptide (Bgl-FaRP1; 292 amino acids) that included eight copies of the tetrapeptide FMRF-NH2 and single copies of FIRF-NH2, FLRF-NH2, and pQFYRI-NH2. The second transcript encoded a precursor (Bgl-FaRP2; 347 amino acids) that comprised 14 copies of the heptapeptide GDPFLRF-NH2 and 1 copy of SKPYMRF-NH2. The precursor encoded by the third transcript (Bgl-FaRP3; 287 amino acids) recapitulated Bgl-FaRP2 but lacked the full SKPYMRF-NH2 peptide. The three precursors shared a common signal peptide, suggesting a genomic organization described previously in gastropods. Immunohistochemical studies were performed on the nervous systems of B. glabrata and B. alexandrina, a major intermediate host for S. mansoni in Egypt. FMRF-NH2-like immunoreactive (FMRF-NH2-li) neurons were located in regions of the central nervous system associated with reproduction, feeding, and cardiorespiration. Antisera raised against non-FMRF-NH2 peptides present in the tetrapeptide and heptapeptide precursors labeled independent subsets of the FMRF-NH2-li neurons. This study supports the participation of FMRF-NH2-related neuropeptides in the regulation of vital physiological and behavioral systems that are altered by parasitism in Biomphalaria
Surfactant-Free Peroxidase-Mediated Enzymatic Polymerization of a Biorenewable Butyrolactone Monomer via a Green Approach:Synthesis of Sustainable Biobased Latexes
A green surfactant-free one-pot horseradish peroxidase-mediated enzymatic polymerization is successfully applied to produce a sustainable and thermally stable biobased high average molar mass poly(α-methylene-γ-butyrolactone) (PMBL) at ambient conditions in water for the first time. The initiation step required only very low concentrations of hydrogen peroxide and 2,4-pentanedione water-soluble initiator to generate the keto-enoxy radicals responsible for forming the primary latex particles. The polymer nanoparticles can be seen as monodisperse, and the biobased latexes are colloidally stable and likely stabilized by the adsorption of 2,4-pentanedione moieties on the particle surfaces. Polymerizations in air produced a 98% yield of PMBL after only 3 h, highlighting the relevance of molecular oxygen. An array of characterization techniques such as dynamic light scattering (DLS), Fourier transform infrared (FTIR), 1H, 13C, and HSQC two-dimensional (2D) nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and size-exclusion chromatography (SEC) are used to confirm the properties of the synthesized latexes. The PMBL exhibited high thermal stability, with only a 5% weight loss at 340 °C and a glass-transition temperature of 200 °C, which is double that of polymethyl methacrylate (PMMA). This research provides an interesting pathway for the synthesis of sustainable biobased latexes via enzymes in a green environment using just water at ambient conditions and the potential use of the polymer in high-temperature applications.</p
Surfactant-Free Peroxidase-Mediated Enzymatic Polymerization of a Biorenewable Butyrolactone Monomer via a Green Approach:Synthesis of Sustainable Biobased Latexes
A green surfactant-free one-pot horseradish peroxidase-mediated enzymatic polymerization is successfully applied to produce a sustainable and thermally stable biobased high average molar mass poly(α-methylene-γ-butyrolactone) (PMBL) at ambient conditions in water for the first time. The initiation step required only very low concentrations of hydrogen peroxide and 2,4-pentanedione water-soluble initiator to generate the keto-enoxy radicals responsible for forming the primary latex particles. The polymer nanoparticles can be seen as monodisperse, and the biobased latexes are colloidally stable and likely stabilized by the adsorption of 2,4-pentanedione moieties on the particle surfaces. Polymerizations in air produced a 98% yield of PMBL after only 3 h, highlighting the relevance of molecular oxygen. An array of characterization techniques such as dynamic light scattering (DLS), Fourier transform infrared (FTIR), 1H, 13C, and HSQC two-dimensional (2D) nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and size-exclusion chromatography (SEC) are used to confirm the properties of the synthesized latexes. The PMBL exhibited high thermal stability, with only a 5% weight loss at 340 °C and a glass-transition temperature of 200 °C, which is double that of polymethyl methacrylate (PMMA). This research provides an interesting pathway for the synthesis of sustainable biobased latexes via enzymes in a green environment using just water at ambient conditions and the potential use of the polymer in high-temperature applications.</p
Anchoring tools to communities: insights into perceptions of flood informational tools from a flood-prone community in Louisiana, USA
The lack of community-relevant flood informational resources and tools often results in inadequate and divergent understandings of flood risk and can impede communities' ability to function cohesively in the face of increasing flood threats. The current study reports on a set of workshops that the authors conducted with various groups (citizens, city engineers and planners, realtors and builders, and media representatives) within a flood prone community to evaluate how novel hydroinformatic tools that include hydrodynamic modeling, geospatial visualization, and socioeconomic analysis can enhance understanding of flood risk and engagement in flood risk mitigation among diverse community members. The workshops were designed to help identify stakeholder preferences regarding key functionality needed for integrated hydroinformatic technologies and socioeconomic analyses for flood risk reduction. Workshop participants were asked to use and comment on examples of prototype flood risk informational tools, such as: (1) flood damage estimation tool, (2) drivability and emergency accessibility tool, and (3) community-scale social and economic metrics tool. Data gathered from workshops were analyzed using qualitative analysis based on a grounded-theory approach. Data were coded by hand based on themes identified by the research team and incorporated deviant case analysis to ensure minority opinions was represented. The study results are focused on the following main themes and how flood tools can address them: (1) improving the understanding of flood risk and engagement in flood risk mitigation, (2) reducing the gap between individual and community risk, (3) challenges in communicating flood risk information, (4) enhancing relevance to and engagement of the community, and (5) enabling actionable information. Our research demonstrates the need for community-anchored tools and technologies that can illustrate local context, include local historical and simulated events at multiple levels of community impact, enable analyses by flood professionals while also providing simplified tools of use by citizens, and allow individuals to expand their knowledge beyond their homes, businesses, and places of work
Self-assessment and studentsâ study strategies in a community of clinical practice: A qualitative study
: Self-assessment is recognized as a necessary skill for lifelong learning. It is widely reported to offer numerous advantages to the learner. The research evaluated the impact of students’ and supervisors’ self-assessment and feedback training on students’ perceptions and practices of self-assessment. Moreover, it evaluated the effect of self-assessment process on students’ study strategies within a community of clinical practice.: We conducted a qualitative phenomenological study from May 2008 to December 2009. We held 37 semi-structured individual interviews with three different cohorts of undergraduate medical students until we reached data saturation. The cohorts were exposed to different contexts while experiencing their clinical years’ assessment program. In the interviews, students’ perceptions and interpretations of ‘self-assessment practice’ and ‘supervisor-provided feedback’ within different contexts and the resulting study strategies were explored.: The analysis of interview data with the three cohorts of students yielded three major themes: strategic practice of self-assessment, self-assessment and study strategies, and feedback and study strategies. It appears that self-assessment is not appropriate within a summative context, and its implementation requires cultural preparation. Despite education and orientation on the two major components of the self-assessment process, feedback was more effective in enhancing deeper study strategies.: This research suggests that the theoretical advantages linked to the self-assessment process are a result of its feedback component rather than the practice of self-assessment isolated from feedback. Further research exploring the effects of different contextual and personal factors on students’ self-assessment is needed
Digital tools in allergy and respiratory care
Patient care in the allergy and respiratory fields is advancing rapidly, offering the possibility of the inclusion of a variety of digital tools that aim to improve outcomes of care. Impaired access to several health care facilities during the COVID-19 pandemic has considerably increased the appetite and need for the inclusion of e-health tools amongst end-users. Consequently, a multitude of different e-health tools have been launched worldwide with various registration and access options, and with a wide range of offered benefits. From the perspective of both patients and healthcare providers (HCPs), as well as from a legal and device-related perspective, several features are important for the acceptance, effectiveness,and long-term use of e-health tools. Patients and physicians have different needs and expectations of how digital tools might be of help in the care pathway. There is a need for standardization by defining quality assurance criteria.Therefore, the Upper Airway Diseases Committee of the World Allergy Organization (WAO) has taken the initiative to define and propose criteria for quality, appeal, and applicability of e-health tools in the allergy and respiratory care fields from a patient, clinician, and academic perspective with the ultimate aim to improve patient health and outcomes of care
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