RESUMEN
Four host-defense peptides belonging to the tigerinin family (tigerinin-1O: RICTPIPFPMCY; tigerinin-2O: RTCIPIPLVMC; tigerinin-3O: RICTAIPLPMCL; and tigerinin-4O: RTCIPIPPVCF) were isolated from skin secretions of the African crowned bullfrog Hoplobatrachus occipitalis. In aqueous solution at pH 4.8, the cyclic domain of tigerinin-2O adopts a rigid amphipathic conformation that incorporates a flexible N-terminal tail. The tigerinins lacked antimicrobial (MIC > 100 µM) and hemolytic (LC50 > 500 µM) activities but, at a concentration of 20 µg/mL, significantly (P < 0.05) inhibited production of interferon-γ (IFN-γ) by peritoneal cells from C57BL/6 mice without affecting production of IL-10 and IL-17. Tigerinin-2O and -4O inhibited IFN-γ production at concentrations as low as 1 µg/mL. The tigerinins significantly (P ≤ 0.05) stimulated the rate of insulin release from BRIN-BD11 clonal ß-cells without compromising the integrity of the plasma membrane. Tigerinin-1O was the most potent (threshold concentration 1 nM) and the most effective (395% increase over basal rate at a concentration of 1 µM). Tigerinin-4O was the most potent and effective peptide in stimulating the rate of glucagon-like peptide-1 release from GLUTag enteroendocrine cells (threshold concentration 10 nM; 289% increase over basal rate at 1 µM). Tigerinin peptides have potential for development into agents for the treatment of patients with type 2 diabetes.
Asunto(s)
Proteínas Anfibias/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Péptidos/farmacología , Piel/metabolismo , Proteínas Anfibias/química , Proteínas Anfibias/farmacología , Animales , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Humanos , Concentración de Iones de Hidrógeno , Insulina/farmacología , Interleucina-10/metabolismo , Interleucina-17/metabolismo , Ratones , Ratones Endogámicos C57BL , Pruebas de Sensibilidad Microbiana , Péptidos/química , Péptidos/aislamiento & purificación , Rana catesbeiana , Piel/efectos de los fármacosRESUMEN
Vaccine Benefit-Risk (B-R) assessment consists of evaluating the benefits and risks of a vaccine and making a judgment whether the expected key benefits outweigh the potential key risks associated with its expected use. B-R supports regulatory and public health decision-making throughout the vaccine's lifecycle. In August 2021, the Brighton Collaboration's Benefit-Risk Assessment of VAccines by TechnolOgy (BRAVATO) Benefit-Risk Assessment Module working group was established to develop a standard module to support the planning, conduct and evaluation of structured B-R assessments for vaccines from different platforms, based on data from clinical trials, post-marketing studies and real-world evidence. It enables sharing of relevant information via value trees, effects tables and graphical depictions of B-R trade-offs. It is intended to support vaccine developers, funders, regulators and policy makers in high-, middle- or low-income countries to help inform decision-making and facilitate transparent communication concerning development, licensure, deployment and other lifecycle decisions.
Asunto(s)
Vacunas , Medición de Riesgo , Vacunas/efectos adversos , HumanosRESUMEN
Pork has the potential to provide several macro and micronutrients to the diet, as it is a commonly consumed protein in the United States and across many cultures worldwide. There is an absence of clinical and observational studies that isolate the nutritional contribution of various types of pork intake from that of other red and/or processed meats. The objective of this study was to assess consumption patterns and the nutritional contribution of total, processed, fresh, and fresh-lean pork to the diets of participants aged 2+ years enrolled in the National Health and Nutrition Examination Survey (NHANES) 2007-2018 data cycles. The recent National Cancer Institute method was used to disaggregate fresh and processed pork intake from the USDA Food Patterns Equivalents Database. The mean intake of total pork among consumers was estimated to be 79.5 ± 0.82, 54.2 ± 0.69, 54.6 ± 0.93, and 45.9 ± 0.73, g/d for men, women, boys, and girls, respectively. Total pork consumption subtly increased intakes of total energy and several macro and micronutrients, decreased diet quality (HEI-2015) scores (adults only), and consumption of other "healthful" food groups. Only subtle but clinically insignificant effects of pork intake on biomarkers of nutritional status were shown. These trends were largely driven by processed pork consumption and the co-consumption of foods such as condiments. Increasing the availability and education around fresh-lean cuts may help to increase intake of protein and other key nutrients across certain subpopulations, without adversely affecting diet quality and biomarkers of health status.
Asunto(s)
Dieta , Carne de Cerdo , Adulto , Animales , Femenino , Humanos , Masculino , Ingestión de Energía , Conducta Alimentaria , Micronutrientes , Encuestas Nutricionales , Porcinos , Estados Unidos , NiñoRESUMEN
BACKGROUND: Pork provides higher levels of several nutrients important for cognitive maintenance in older adults. A pilot clinical study suggests the addition of moderate amounts of pork to a Mediterranean-style diet improves cognition in older adults. There is an absence of observational research that isolates effects of pork from other red meats. OBJECTIVE: To examine the relationship of pork intake on cognitive performance in older adults. METHODS: Cross-sectional data from the U.S. National Health and Nutrition Examination Survey (NHANES) 2011-2014 cycles were used in these analyses. Pork intake was assessed using data from two non-consecutive 24-h dietary recalls. Cognitive function was assessed by the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word Learning, CERAD Delayed Recall, Animal Fluency, and Digital Substitution tests. Statistical analyses were adjusted for sample weighting and survey design variables to account for the complex design. Student t-tests (continuous variables) and Pearson chi-squared tests (categorical variables) were employed to compare participant characteristics between the low and normal cognitive performance groups. Logistic regression was used to determine the relationship of pork intake (low, medium, and high) with prevalence of low cognitive performance, with the non-consumer group as the referent category. RESULTS: Pork intake was not beneficially or detrimentally associated performance on the any of the cognitive tests in both the crude and multivariate models (pâ>â0.05). CONCLUSIONS: Prospective cohort investigations and larger/longer-term clinical trials are needed to fully elucidate effects of pork intake on cognition in older adults.
Asunto(s)
Enfermedad de Alzheimer , Carne de Cerdo , Carne Roja , Animales , Humanos , Porcinos , Anciano , Encuestas Nutricionales , Estudios Transversales , Estudios Prospectivos , CogniciónRESUMEN
African clawed frogs of the Xenopodinae (Xenopus+Silurana) constitute a well-defined system in which to study the evolutionary trajectory of duplicated genes and are a source of antimicrobial peptides with therapeutic potential. Allopolyploidization events within the Xenopodinae have given rise to tetraploid, octoploid, and dodecaploid species. The primary structures and distributions of host-defense peptides from the tetraploid frogs Xenopus borealis, Xenopus clivii, Xenopus laevis, Xenopus muelleri, "X. muelleri West", and Xenopus petersii may be compared with those from the octoploid frogs Xenopus amieti and X. andrei. Similarly, components in skin secretions from the diploid frog Silurana tropicalis may be compared with those from the tetraploid frog Silurana paratropicalis. All Xenopus antimicrobial peptides may be classified in the magainin, peptide glycine-leucine-amide (PGLa), caerulein-precursor fragment (CPF), and xenopsin-precursor fragment (XPF) families. However, the numbers of paralogs from the octoploid frogs were not significantly greater than the corresponding numbers from the tetraploid frogs. Magainins were not identified in skin secretions of Silurana frogs and the multiplicity of the PGLa, CPF, and XPF peptides from S. paratropicalis was not greater than that of S. tropicalis. The data indicate, therefore, that nonfunctionalization (gene silencing) has been the most common fate of antimicrobial peptide genes following polyploidization. While some duplicated gene products retain high antimicrobial potency (subfunctionalization), the very low activity of others suggests that they may be evolving towards a new biological role (neofunctionalization). CPF-AM1 and PGLa-AM1 from X. amieti show potential for development into anti-infective agents for use against antibiotic-resistant gram-negative bacteria.
Asunto(s)
Péptidos Catiónicos Antimicrobianos/metabolismo , Evolución Molecular , Pipidae/metabolismo , Piel/metabolismo , Secuencia de Aminoácidos , Animales , Péptidos Catiónicos Antimicrobianos/genética , Datos de Secuencia Molecular , Filogenia , Pipidae/genética , Ploidias , Alineación de SecuenciaRESUMEN
Asymptomatic captive bred and wild-caught mountain chicken frogs (Leptodactylus fallax) were radiographed for evidence of metabolic bone disease (MBD). All 22 captive bred frogs had multiple folding fractures of long bones, decreased bone density, and cortical thinning, whereas none of the 11 wild-caught frogs had any radiographic evidence of MBD. These findings suggest that the nutritional requirements of L. fallax need to be examined for captive management purposes.
Asunto(s)
Enfermedades Óseas Metabólicas/veterinaria , Fracturas Espontáneas/veterinaria , Ranidae , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Animales Salvajes , Enfermedades Óseas Metabólicas/complicaciones , Enfermedades Óseas Metabólicas/diagnóstico , Calcio/deficiencia , Calcio de la Dieta/administración & dosificación , Dieta/veterinaria , Fracturas Espontáneas/diagnóstico , Fracturas Espontáneas/etiologíaRESUMEN
Capybaras (Hydrochoerus hydrochaeris) are the world's largest rodent. Owing to its uniqueness, 50 AZA institutions in North America display this species. As shown by a survey, no standard anesthetic protocol has been developed for this species. As a part of an ongoing behavioral study in Venezuela, capybaras were surgically implanted with radio transmitters. Animals were randomly assigned to one of the three immobilization protocols: (1) Tiletamine HCl/Zolazepam HCl, (2) Tiletamine HCl/Zolazepam HCl/Medetomidine HCl, and (3) Tiletamine HCl/Zolazepam HCl/Medetomidine HCl/Butorphanol tartrate. The protocol recommended for minimally invasive procedures when inhalant anesthetics are unavailable is a combination of Tiletamine HCl/Zolazepam HCl/Medetomidine HCl/Butorphanol tartrate. This is based on ease of administration, volume, onset of action, depth of anesthetic achieved, reversibility, safety, and costs.
Asunto(s)
Inmovilización/veterinaria , Roedores/fisiología , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/farmacología , Anestésicos Disociativos/administración & dosificación , Anestésicos Disociativos/farmacología , Animales , Ansiolíticos/administración & dosificación , Ansiolíticos/farmacología , Butorfanol/administración & dosificación , Butorfanol/farmacología , Quimioterapia Combinada , Hipnóticos y Sedantes/administración & dosificación , Hipnóticos y Sedantes/farmacología , Medetomidina/administración & dosificación , Medetomidina/farmacología , Tiletamina/administración & dosificación , Tiletamina/farmacología , Zolazepam/administración & dosificación , Zolazepam/farmacologíaRESUMEN
Peptidomic analysis of norepinephrine-stimulated skin secretions from the Caribbean frog Leptodactylus validus Garman, 1888 led to the identification of three peptides with previously undescribed sequences that were structurally similar to those of antimicrobial peptides isolated from other species of leptodactylid frogs. These paralogs have been termed ocellatin-V1 (GVVDILKGAGKDLLAHALSKLSEKV.NH(2)), ocellatin-V2 (GVLDILKGAGKDLLAHALSKISEKV.NH(2)), and ocellatin-V3 (GVLDILTGAGKDLLAHALSKLSEKV.NH(2)). The very low antimicrobial potency (MIC>200microM) against Escherichia coli and Staphylococcus aureus associated with the peptides is probably a consequence of their lack of amphipathicity and reduced cationicity compared with active members of the ocellatin family from related species.
Asunto(s)
Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Anuros , Secuencia de Aminoácidos , Animales , Antiinfecciosos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Región del Caribe , Cromatografía Líquida de Alta Presión , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Peptidomic analysis of norepinephrine-stimulated skin secretions from Hose's rock frog Odorrana hosii (Boulenger, 1891) led to the isolation of 8 peptides with differential antibacterial activities. Structural characterization demonstrated that the peptides belonged to the esculentin-1 (1 peptide), esculentin-2 (1 peptide), brevinin-1 (2 peptides), brevinin-2 (2 peptides), and nigrocin-2 (2 peptides) families of antimicrobial peptides. Similar analysis of skin secretions from the Malaysian fire frog Hylarana picturata (Boulenger, 1920) led to the isolation and characterization of peptides belonging to the brevinin-1 (2 peptides), brevinin-2 (5 peptides), and temporin (1 peptide) families. The differences in antimicrobial activities of paralogous peptides provide insight into structure-activity relationships, emphasizing the importance of cationicity in determining potency. The substitution Lys11-->Gln in brevinin-1HSa (FLPAVLRVAAKIVPTVFCAISKKC) from O. hosii abolishes growth inhibitory activity against Escherichia coli but has no effect on the high potency (MIC = 8 microg/ml) against Staphylococcus aureus. In contrast, the substitution (Gly4-->Asp) in brevinin-2PTb (GFKGAFKNVMFGIAKSAGKSALNALACKIDKSC) from H. picturata reduces activity against both E. coli and S. aureus. Cladistic analysis based upon the amino acid sequences of the brevinin-2 peptides from Asian frogs provides evidence for sister taxon relationships between O. hosii and O. livida and between H. picturata and H. güntheri.
Asunto(s)
Péptidos Catiónicos Antimicrobianos/metabolismo , Anuros/metabolismo , Piel/metabolismo , Secuencia de Aminoácidos , Animales , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/genética , Datos de Secuencia Molecular , FilogeniaRESUMEN
The Mexican burrowing toad Rhinophrynus dorsalis is the sole extant representative of the Rhinophrynidae. United in the superfamily Pipoidea, the Rhinophrynidae is considered to be the sister-group to the extant Pipidae which comprises Hymenochirus, Pipa, Pseudhymenochirus and Xenopus. Cationic, α-helical host-defense peptides of the type found in Hymenochirus, Pseudhymenochirus, and Xenopus species (hymenochirins, pseudhymenochirins, magainins, and peptides related to PGLa, XPF, and CPF) were not detected in norepinephrine-stimulated skin secretions of R. dorsalis. Skin secretions of representatives of the genus Pipa also do not contain cationic α-helical host-defense peptides which suggest, as the most parsimonious hypothesis, that the ability to produce such peptides by frogs within the Pipidae family arose in the common ancestor of (Hymenochirus+Pseudhymenochirus)+Xenopus after divergence from the line of evolution leading to extant Pipa species. Peptidomic analysis of the R. dorsalis secretions led to the isolation of rhinophrynin-27, a proline-arginine-rich peptide with the primary structure ELRLPEIARPVPEVLPARLPLPALPRN, together with rhinophrynin-33 containing the C-terminal extension KMAKNQ. Rhinophrynin-27 shows limited structural similarity to the porcine multifunctional peptide PR-39 but it lacks antimicrobial and cytotoxic activities. Like PR-39, the peptide adopts a poly-l-proline helix but some changes in the circular dichroism spectrum were observed in the presence of anionic sodium dodecylsulfate micelles consistent with the stabilization of turn structures.
Asunto(s)
Proteínas Anfibias/química , Péptidos Catiónicos Antimicrobianos/química , Pipidae/fisiología , Piel/metabolismo , Células A549 , Secuencia de Aminoácidos , Proteínas Anfibias/aislamiento & purificación , Proteínas Anfibias/metabolismo , Proteínas Anfibias/farmacología , Animales , Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/metabolismo , Péptidos Catiónicos Antimicrobianos/farmacología , Arginina/química , Bacterias/efectos de los fármacos , Dicroismo Circular , Humanos , Micelas , Prolina/química , Proteómica , Dodecil Sulfato de Sodio/químicaRESUMEN
Norepinephrine-stimulated skin secretions from the Sante Fe frog Leptodactylus laticeps contained high concentrations of a peptide, termed laticeptin, with the primary structure Gly-Val-Val-Asp-Ile-Leu-Lys-Gly-Ala-Ala-Lys-Asp-Leu-Ala-Gly-His-Leu-Ala-Thr-Lys-Val-Met-Asn-Lys-Leu.NH(2). Laticeptin inhibited the growth of selected Gram-negative bacteria but the lack of activity against Gram-positive bacteria and the very low hemolytic activity is probably a consequence of the weak amphipathicity of the peptide in its alpha-helical conformation.
Asunto(s)
Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Piel/metabolismo , Secuencia de Aminoácidos , Animales , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Anuros , Eritrocitos/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Hemólisis , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Datos de Secuencia MolecularRESUMEN
BACKGROUND: An organization's ability to change is driven by its culture, which in turn has a significant impact on safety. The six-step Comprehensive Unit-Based Safety Program (CUSP) is intended to improve local culture and safety. A Web-based project management tool for CUSP was developed and then pilot tested at two hospitals. HOW ECUSP WORKS: Once a patient safety concern is identified (step 3), a unit-level interdisciplinary safety committee determines issue criticality and starts up the projects (step 4), which are managed using project management tools within eCUSP (step 5). On a project's completion, the results are disseminated through a shared story (step 6). CASE STUDIES: OSF St. Joseph's Medical Center-The Medical Birthing Center (Bloomington, Illinois), identified 11 safety issues, implemented 11 projects, and created 9 shared stories--including one for its Armband Project. The Johns Hopkins Hospital (Baltimore) Medical Progressive Care (MPC4) Unit identified 5 safety issues and implemented 4 ongoing projects, including the intravenous (IV) Tubing Compliance Project. DISCUSSION: The eCUSP tool's success depends on an organizational commitment to creating a culture of safety.
Asunto(s)
Internet , Administración de la Seguridad/organización & administración , Instituciones de Salud , Errores Médicos/prevención & control , Estudios de Casos Organizacionales , Cultura Organizacional , Innovación Organizacional , Desarrollo de Programa , Calidad de la Atención de Salud , Estados UnidosRESUMEN
The Uganda clawed frog Xenopus ruwenzoriensis with a karyotype of 2n=108 is one of the very few vertebrates with dodecaploid status. Peptidomic analysis of norepinephrine-stimulated skin secretions from this species led to the isolation and structural characterization of 23 host-defense peptides belonging to the following families: magainin (3 peptides), peptide glycine-leucine-amide (PGLa; 6 peptides), xenopsin precursor fragment (XPF; 3 peptides), caerulein precursor fragment (CPF; 8 peptides), and caerulein precursor fragment-related peptide (CPF-RP; 3 peptides). In addition, the secretions contained caerulein, identical to the peptide from Xenopus laevis, and two peptides that were identified as members of the trefoil factor family (TFF). The data indicate that silencing of the host-defense peptide genes following polyploidization has been appreciable and non-uniform. Consistent with data derived from comparison of nucleotide sequences of mitochrondrial and nuclear genes, cladistic analyses based upon the primary structures of the host-defense peptides provide support for an evolutionary scenario in which X. ruwenzoriensis arose from an allopolyploidization event involving an octoploid ancestor of the present-day frogs belonging to the Xenopus amieti species group and a tetraploid ancestor of Xenopus pygmaeus.
Asunto(s)
Norepinefrina/farmacología , Fragmentos de Péptidos/análisis , Pipidae/metabolismo , Piel/metabolismo , Proteínas de Xenopus/metabolismo , Animales , Evolución Molecular , Fragmentos de Péptidos/aislamiento & purificación , Piel/efectos de los fármacos , Vasoconstrictores/farmacologíaRESUMEN
Maternal vaccination is an important area of research and requires appropriate and internationally comparable definitions and safety standards. The GAIA group, part of the Brighton Collaboration was created with the mandate of proposing standardised definitions applicable to maternal vaccine research. This study proposes international definitions for neonatal infections. The neonatal infections GAIA working group performed a literature review using Medline, EMBASE and the Cochrane collaboration and collected definitions in use in neonatal and public health networks. The common criteria derived from the extensive search formed the basis for a consensus process that resulted in three separate definitions for neonatal blood stream infections (BSI), meningitis and lower respiratory tract infections (LRTI). For each definition three levels of evidence are proposed to ensure the applicability of the definitions to different settings. Recommendations about data collection, analysis and presentation are presented and harmonized with the Brighton Collaboration and GAIA format and other existing international standards for study reporting.
Asunto(s)
Control de Enfermedades Transmisibles , Inmunización/efectos adversos , Infecciones/epidemiología , Vacunas/efectos adversos , Bacteriemia/epidemiología , Bacteriemia/prevención & control , Recolección de Datos , Femenino , Humanos , Recién Nacido , Meningitis/epidemiología , Meningitis/prevención & control , Sepsis/epidemiología , Sepsis/prevención & control , Estadística como AsuntoRESUMEN
During the breeding season of the mountain chicken frog Leptodactylus fallax, fighting between males results in the emergence of dominant animals that subsequently attract females to nesting sites. A peptide, termed Leptodactylus aggression-stimulating peptide (LASP), was isolated from norepinephrine-stimulated skin secretions from male specimens of L. fallax that was not present in skin secretions obtained from females. The primary structure of the peptide was established as: Gly-Leu-Trp-Asp-Asp-Leu-Lys-Ala-Ala-Ala-Lys-Lys-Val-Val-Ser-Ser-Leu-Ala-Ser-Ala-Ala-Ile-Glu-Lys-Leu NH2. LASP had no pheromone-like action on females but had a chemoattractive effect on males and stimulated aggressive behaviors, such as rearing and leaping. It is suggested that this peptide may play an important role in initiating the competitive male-male interactions that are associated with the onset of reproductive behavior in L. fallax.
Asunto(s)
Agresión , Péptidos/metabolismo , Piel/metabolismo , Secuencia de Aminoácidos , Animales , Anuros , Cromatografía Líquida de Alta Presión , Femenino , Masculino , Péptidos/química , Péptidos/aislamiento & purificación , Péptidos/fisiología , Conducta Sexual AnimalRESUMEN
A 25 amino-acid-residue, C-terminally alpha-amidated peptide with antimicrobial activity, which has been termed fallaxin, was isolated in high yield from the norepinephrine-stimulated skin secretions of the mountain chicken frog Leptodactylus fallax (Anura:Leptodactylidae). The amino acid sequence of the peptide (Gly-Val-Val-Asp-Ile-Leu-Lys-Gly-Ala-Ala-Lys-Asp-Ile-Ala-Gly-His-Leu-Ala-Ser-Lys-Val-Met-Asn-Lys-Leu.NH2) shows structural similarity with members of the ranatuerin-2 family previously isolated from the skins of frogs of the genus Rana that are only distantly related to the Leptodactylidae. This observation is consistent with the hypothesis that many frog skin antimicrobial peptides are related evolutionarily, having arisen from multiple duplications of an ancestral gene that existed before the radiation of the different families. Fallaxin inhibited the growth of reference strains of Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae) but with relatively low potency (MIC> or =20 microM) and was inactive against the Gram-positive bacterium (Staphylococcus aureus) and the yeast Candida albicans. The hemolytic activity of fallaxin was very low (HC50>200 microM). A second peptide, comprising residues (1-22) of fallaxin, was also isolated from the skin secretions but this component was inactive against the microorganisms tested.
Asunto(s)
Péptidos Catiónicos Antimicrobianos/metabolismo , Péptidos Catiónicos Antimicrobianos/farmacología , Anuros/metabolismo , Piel/metabolismo , Secuencia de Aminoácidos , Animales , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Eritrocitos/efectos de los fármacos , Femenino , Hemólisis/efectos de los fármacos , Humanos , Datos de Secuencia Molecular , Alineación de Secuencia , Piel/químicaRESUMEN
Skin conductance (SC) reflects stimulus significance and can be measured by integrating electrodes directly onto a smartphone housing such that they are naturally contacted when gripped. However, grip artifacts naturally arise during operation since grip forces can vary. We explored the effects of grip force on SC to determine feasibility and to draw guidelines on artifact mitigation. For this purpose, a prototype was built with integrated SC electrodes with colocated force sensors, and data was collected from 24 participants gripping the prototype across different grip force conditions. Our analysis showed that static forces greater than 2.0 N were associated with significant SC distortion, and artifacts induced from dynamic grip forces were buffered if the SC level was at least 1.1 microsiemens. Our findings are relevant for future applications of SC sensing on smartphones, which may enable interesting and highly contextual user experiences.
Asunto(s)
Computadoras de Mano , Electrodos , Respuesta Galvánica de la Piel/fisiología , Fuerza de la Mano/fisiología , Monitoreo Ambulatorio/instrumentación , Adolescente , Adulto , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Teléfono Inteligente , Adulto JovenRESUMEN
Peptidomic analysis of norepinephrine-stimulated skin secretions from the octoploid Mawa clawed frog Xenopus boumbaensis Loumont, 1983 led to the identification and characterization of 15 host-defense peptides belonging to the magainin (two peptides), peptide glycine-leucine-amide (PGLa; three peptides), xenopsin precursor fragment (XPF; three peptides), caerulein precursor fragment (CPF; two peptides), and caerulein precursor fragment-related peptide (CPF-RP; five peptides) families. In addition, caerulein and three peptides with structural similarity to the trefoil factor family (TFF) peptides, xP2 and xP4 from Xenopus laevis were also present in the secretions. Consistent with data from comparisons of the nucleotides sequence of mitochondrial and nuclear genes, the primary structures of the peptides suggest a close phylogenetic relationship between X. boumbaensis and the octoploid frogs Xenopus amieti and Xenopus andrei. As the three species occupy disjunct ranges within Cameroon, it is suggested that they diverged from a common ancestor by allopatric speciation.
Asunto(s)
Proteínas Anfibias/química , Péptidos/química , Piel/metabolismo , Proteínas Anfibias/genética , Proteínas Anfibias/metabolismo , Animales , Péptidos/genética , Péptidos/metabolismo , Factor Trefoil-2 , XenopusRESUMEN
Peptidomic analysis of norepinephrine-stimulated skin secretions of the Orinoco lime tree frog Sphaenorhynchus lacteus (Hylidae, Hylinae) revealed the presence of three structurally related host-defense peptides with limited sequence similarity to frenatin 2 from Litoria infrafrenata (Hylidae, Pelodryadinae) and frenatin 2D from Discoglossus sardus (Alytidae). Frenatin 2.1S (GLVGTLLGHIGKAILG.NH2) and frenatin 2.2S (GLVGTLLGHIGKAILS.NH2) are C-terminally α-amidated but frenatin 2.3S (GLVGTLLGHIGKAILG) is not. Frenatin 2.1S and 2.2S show potent bactericidal activity against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MIC ≤16µM) but are less active against a range of Gram-negative bacteria. Frenatin 2.1S (LC50=80±6 µM) and 2.2S (LC50=75±5 µM) are cytotoxic against non-small cell lung adenocarcinoma A549 cells but are less hemolytic against human erythrocytes (LC50=167±8 µM for frenatin 2.1S and 169±7 µM for 2.2S). Weak antimicrobial and cytotoxic potencies of frenatin 2.3S demonstrate the importance of C-terminal α-amidation for activity. Frenatin 2.1S and 2.2S significantly (P<0.05) increased production of proinflammatory cytokines IL-1ß and IL-23 by lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophages and frenatin 2.1S also enhanced production of TNF-α. Effects on IL-6 production were not significant. Frenatin 2.2S significantly downregulated production of the anti-inflammatory cytokine IL-10 by LPS-stimulated cells. The data support speculation that frenatins act on skin macrophages to produce a cytokine-mediated stimulation of the adaptive immune system in response to invasion by microorganisms. They may represent a template for the design of peptides with therapeutic applications as immunostimulatory agents.