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Itch is an unpleasant sensation that evokes a desire to scratch. The skin barrier is constantly exposed to microbes and their products. However, the role of microbes in itch generation is unknown. Here, we show that Staphylococcus aureus, a bacterial pathogen associated with itchy skin diseases, directly activates pruriceptor sensory neurons to drive itch. Epicutaneous S. aureus exposure causes robust itch and scratch-induced damage. By testing multiple isogenic bacterial mutants for virulence factors, we identify the S. aureus serine protease V8 as a critical mediator in evoking spontaneous itch and alloknesis. V8 cleaves proteinase-activated receptor 1 (PAR1) on mouse and human sensory neurons. Targeting PAR1 through genetic deficiency, small interfering RNA (siRNA) knockdown, or pharmacological blockade decreases itch and skin damage caused by V8 and S. aureus exposure. Thus, we identify a mechanism of action for a pruritogenic bacterial factor and demonstrate the potential of inhibiting V8-PAR1 signaling to treat itch.
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Péptido Hidrolasas , Prurito , Receptor PAR-1 , Infecciones Estafilocócicas , Staphylococcus aureus , Animales , Humanos , Ratones , Péptido Hidrolasas/metabolismo , Prurito/microbiología , Receptor PAR-1/metabolismo , Staphylococcus aureus/enzimología , Staphylococcus aureus/patogenicidad , Staphylococcus aureus/fisiología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/patologíaRESUMEN
BACKGROUND: Atopic dermatitis skin lesions exhibit increased infiltration by basophils. Basophils produce IL-4, which plays an important role in the pathogenesis of atopic dermatitis. OBJECTIVE: We sought to determine the role of basophils in a mouse model of antigen-driven allergic skin inflammation. METHODS: Wild-type mice, mice with selective and inducible depletion of basophils, and mice expressing Il4-driven enhanced green fluorescent protein were subjected to epicutaneous sensitization with ovalbumin or saline. Sensitized skin was examined by histology for epidermal thickening. Cells were analyzed for surface markers and intracellular expression of enhanced green fluorescent protein by flow cytometry. Gene expression was evaluated by real-time reverse transcription-quantitative PCR. RESULTS: Basophils were important for epidermal hyperplasia, dermal infiltration by CD4+ T cells, mast cells, and eosinophils in ovalbumin-sensitized mouse skin and for the local and systemic TH2 response to epicutaneous sensitization. Moreover, basophils were the major source of IL-4 in epicutaneous-sensitized mouse skin and promote the ability of dendritic cells to drive TH2 polarization of naive T cells. CONCLUSION: Basophils play an important role in the development of allergic skin inflammation induced by cutaneous exposure to antigen in mice.
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Basófilos , Dermatitis Atópica , Interleucina-4 , Ovalbúmina , Células Th2 , Animales , Basófilos/inmunología , Ratones , Interleucina-4/inmunología , Interleucina-4/genética , Dermatitis Atópica/inmunología , Dermatitis Atópica/patología , Ovalbúmina/inmunología , Células Th2/inmunología , Piel/inmunología , Piel/patología , Ratones Endogámicos C57BL , Ratones Endogámicos BALB C , Modelos Animales de Enfermedad , Células Dendríticas/inmunología , Ratones Transgénicos , Mastocitos/inmunologíaRESUMEN
BACKGROUND: Skin colonization with Staphylococcus aureus aggravates atopic dermatitis and exaggerates allergic skin inflammation in mice. IL-4 receptor α (IL-4Rα) blockade is beneficial in atopic dermatitis and reduces Saureus skin colonization through unknown mechanisms. The cytokine IL-17A restrains Saureus growth. OBJECTIVES: This study sought to examine the effect of IL-4Rα blockade on Saureus colonization at sites of allergic skin inflammation in mice and determine the mechanism involved. METHODS: BALB/c mice were epicutaneously sensitized with ovalbumin (OVA). Immediately after, PSVue 794-labeled S aureus strain SF8300 or saline was applied and a single dose of anti-IL-4Rα blocking antibody, a mixture of anti-IL-4Rα and anti-IL-17A blocking antibodies, or IgG isotype controls were administered intradermally. Saureus load was assessed 2 days later by in vivo imaging and enumeration of colony forming units. Skin cellular infiltration was examined by flow cytometry and gene expression by quantitative PCR and transcriptome analysis. RESULTS: IL-4Rα blockade decreased allergic skin inflammation in OVA-sensitized skin, as well as in OVA-sensitized and Saureus-exposed skin, evidenced by significantly decreased epidermal thickening and reduced dermal infiltration by eosinophils and mast cells. This was accompanied by increased cutaneous expression of Il17a and IL-17A-driven antimicrobial genes with no change in Il4 and Il13 expression. IL-4Rα blockade significantly decreased Saureus load in OVA-sensitized and S aureus-exposed skin. IL-17A blockade reversed the beneficial effect of IL-4Rα blockade on Saureus clearance and reduced the cutaneous expression of IL-17A-driven antimicrobial genes. CONCLUSIONS: IL-4Rα blockade promotes Saureus clearance from sites of allergic skin inflammation in part by enhancing IL-17A expression.
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Antiinfecciosos , Dermatitis Atópica , Ratones , Animales , Dermatitis Atópica/tratamiento farmacológico , Interleucina-17/genética , Ovalbúmina , Inflamación , Piel , Antígenos , Receptores de Interleucina-4 , Ratones Endogámicos BALB CRESUMEN
Aberrant expression of CD43 in malignant tumors of nonhematopoietic origin such as those from lung, cervix, colon, and breast has been shown to correlate with poor prognosis, providing tumor cells with enhanced motility, anchorage-independent growth, and in vivo tumor size, while protecting the cells of NK lysis and apoptosis. To further characterize the role of CD43 in cell transformation, we tested whether interfering its expression modified the capacity of the A549 non-small cell lung cancer cells to secrete molecules contributing to malignancy. The proteomic analysis of the secretome of serum-starved A549 cells revealed that cells expressing normal levels of CD43 released significantly high levels of molecules involved in extracellular matrix organization, angiogenesis, platelet degranulation, collagen degradation, and inflammation, as compared to CD43 RNAi cells. This data reveals a novel and unexpected role for CD43 in lung cancer development, mainly in remodeling the tumor microenvironment.
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Matriz Extracelular/metabolismo , Leucosialina/metabolismo , Neoplasias Pulmonares/irrigación sanguínea , Neoplasias Pulmonares/metabolismo , Neovascularización Patológica/metabolismo , Células A549 , Silenciador del Gen , Humanos , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , FN-kappa B/metabolismo , Factor de Transcripción STAT3/metabolismo , Microambiente TumoralRESUMEN
Conversion of CO2 into valuable molecules is a field of intensive investigation with the aim of developing scalable technologies for making fuels using renewable energy sources. While electrochemical reduction into CO and formate are approaching industrial maturity, a current challenge is obtaining more reduced products like methanol. However, literature on the matter is scarce, and even more for the use of molecular catalysts. Here, we demonstrate that cobalt phthalocyanine, a well-known catalyst for the electrochemical conversion of CO2 to CO, can also catalyze the reaction from CO2 or CO to methanol in aqueous electrolytes at ambient conditions of temperature and pressure. The studies identify formaldehyde as a key intermediate and an unexpected pH effect on selectivity. This paves the way for establishing a sequential process where CO2 is first converted to CO which is subsequently used as a reactant to produce methanol. Under ideal conditions, the reaction shows a global Faradaic efficiency of 19.5 % and chemical selectivity of 7.5 %.
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The high prevalence of constipation in long-term care (LTC) residents has been a long-standing issue for caregivers, attending health professionals, and the residents themselves. The traditional medical response has been to utilize pharmaceutical laxatives, enemas, and suppositories for treatment. The purpose of this review was to determine if fibre supplementation (including fibre added to foods) is effective in increasing stool frequency, improving stool consistency, and decreasing laxative use in LTC residents. A systematic search was conducted using PubMed and CINAHL databases, inclusive to March 2017. Search terms included: "long-term care" or "nursing home" AND "fiber (fibre)," "bran," "psyllium," "inulin," or "prebiotic." Intervention trials of fibre supplementation with ≥5 LTC residents were included. The search generated 456 articles following removal of duplicates; 8 studies met the inclusion criteria. Three additional trials were identified through a hand search of references of pertinent articles. Current evidence suggests that added fibre may be effective in increasing stool frequency and/or decreasing laxative use in LTC residents and, thus, may lessen the burden of constipation. However, randomized controlled trials are needed to clearly demonstrate the effects of adding fibre to foods, particularly insoluble and less fermentable sources, on constipation in LTC residents.
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Estreñimiento/terapia , Fibras de la Dieta/administración & dosificación , Laxativos/administración & dosificación , Cuidados a Largo Plazo/métodos , Canadá/epidemiología , Estreñimiento/epidemiología , Estreñimiento/etiología , Suplementos Dietéticos , Humanos , Estado Nutricional , Calidad de VidaRESUMEN
Foreign modelling agent reactions (FMAR) are the result of the injection of unapproved high-viscosity fluids with the purpose of cosmetic body modelling. Its consequences lead to ulceration, disfigurement and even death, and it has reached epidemic proportions in several regions of the world. We describe a series of patients treated for FMARs in a specialised wound care centre and a thorough review of the literature. A retrospective chart review was performed from January 1999 to September 2015 of patients who had been injected with non-medical foreign agents and who developed cutaneous ulceration needing treatment at the dermatology wound care centre. This study involved 23 patients whose ages ranged from 22 to 67 years with higher proportion of women and homosexual men. The most commonly injected sites were the buttocks (38·5%), legs (18%), thighs (15·4%) and breasts (11·8%). Mineral oil (39%) and other unknown substances (30·4%) were the most commonly injected. The latency period ranged from 1 week to 17 years. Complications included several skin changes such as sclerosis and ulceration as well as systemic complications. FMAR is a severe syndrome that may lead to deadly complications, and is still very common in Latin America.
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Cosméticos/efectos adversos , Cuerpos Extraños/inmunología , Reacción a Cuerpo Extraño/complicaciones , Aceite Mineral/efectos adversos , Úlcera Cutánea/etiología , Úlcera Cutánea/terapia , Adulto , Anciano , Mama/fisiopatología , Nalgas/fisiopatología , Cosméticos/administración & dosificación , Femenino , Homosexualidad Masculina/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Aceite Mineral/administración & dosificación , Estudios Retrospectivos , Piel/fisiopatología , Adulto JovenRESUMEN
The simultaneous measurement of the decrease of available Fe(II) ions and the increase of available Fe(III) ions allowed the analysis of the ferroxidase activity of two distinct apoferritins. Although recombinant human apoferritin (HuFtH) rapidly oxidizes Fe(II) to Fe(III) , this iron is not properly stored in the ferritin cavity, as otherwise occurs in horse-spleen H/L-apoferritin (HsFt; H=heavy subunit, L=light subunit). Iron storage in these apoferritins was also studied in the presence of two copper-loaded mammalian metallothioneins (MT2 and MT3), a scenario that occurs in different brain-cell types. For HuFtH, unstored Fe(III) ions trigger the oxidation of Cu-MT2 with concomitant Cu(I) release. In contrast, there is no reaction with Cu-MT2 in the case of HsFt. Similarly, Cu-MT3 does not react during either HuFtH or HsFt iron reconstitution. Significantly, the combination of ferritin and metallothionein isoforms reported in glia and neuronal cells are precisely those combinations that avoid a harmful release of Fe(II) and Cu(I) ions.
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Apoferritinas/metabolismo , Ferritinas/metabolismo , Metalotioneína/metabolismo , Animales , Compuestos Férricos/análisis , Compuestos Férricos/metabolismo , Ferritinas/química , Compuestos Ferrosos/análisis , Compuestos Ferrosos/metabolismo , Caballos , Humanos , Metalotioneína/análisis , Proteínas Recombinantes/metabolismoRESUMEN
BACKGROUND: Onychocryptosis is one of the most common painful nail conditions. Conservative treatment may take a long time to obtain effective results. OBJECTIVE: The purpose of this study is to show the effectiveness of a conservative treatment of ingrown nails that shows rapid results. METHODS AND MATERIALS: Patients with painful Stage 1 to 2 onychocryptosis who were not candidates or refused surgery were treated with the cotton cast. The severity and cause of onychocryptosis was clinically evaluated during a 2-month period. A questionnaire was applied to all patients to evaluate pain, final treatment, and possible complications. RESULTS: All patients noticed results in less than 72 hours. Pain subsided in less than 24 hours in half of the patients and before 72 hours in 100% of the patients without the need of other treatments. The use of the cast prevented surgery and the accompanying morbidities in most of the patients (80%). CONCLUSION: The "cotton nail cast" is an effective conservative method for mild nail embedding. It is easy to apply, inexpensive, relieves pain rapidly, and avoids surgery in most patients.
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Fibra de Algodón , Cianoacrilatos , Uñas Encarnadas/terapia , Dolor/prevención & control , Anciano , Vendajes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Uñas Encarnadas/complicaciones , Uñas Encarnadas/patología , Dolor/etiología , Dolor/patología , Paroniquia/etiología , Paroniquia/patología , Paroniquia/prevención & control , Resultado del TratamientoRESUMEN
BACKGROUND: Trichoepithelioma is a benign follicular tumor, affects young female adults, and has three clinical forms: solitary, multiple, or desmoplastic. Diagnosis represents a clinical challenge for the dermatologist. There are many differential diagnoses, and the most important is basal cell carcinoma because they share histological features. It has good prognosis and therefore treatment is usually for aesthetic purposes, even though it is associated with recurrence. METHODS: This is a retrospective study carried out from January 1993 to December 2012 of all the patients who were diagnosed by histopathology to have trichoepithelioma in the dermatology department of the Dr. Manuel Gea González General Hospital. RESULTS: There were 47 cases, of which 70.2% were female, with an average age of 43.6 years. Solitary trichoepithelioma was the most frequent clinical form (66%) and only three of 14 cases of multiple trichoepithelioma had a positive family history.
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Síndromes Neoplásicos Hereditarios , Neoplasias Cutáneas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Niño , Femenino , Hospitales Generales , Humanos , Masculino , Persona de Mediana Edad , Síndromes Neoplásicos Hereditarios/patología , Estudios Retrospectivos , Neoplasias Cutáneas/patología , Adulto JovenRESUMEN
Hydrogels are dynamically evolving 3D networks composed of hydrophilic polymer scaffolds with significant applications in the healthcare and environmental sectors. Notably, protein-based hydrogels mimic the extracellular matrix, promoting cell adhesion. Further enhancing cell proliferation within these scaffolds are matrix-metalloproteinase-triggered amino acid motifs. Integration of cell-friendly modules like peptides and proteins expands hydrogel functionality. These exceptional properties position hydrogels for diverse applications, including biomedicine, biosensors, environmental remediation, and the food industry. Despite significant progress, there is ongoing research to optimize hydrogels for biomedical and environmental applications further. Engineering novel hydrogels with favorable characteristics is crucial for regulating tissue architecture and facilitating ecological remediation. This review explores the synthesis, physicochemical properties, and biological implications of various hydrogel types and their extensive applications in biomedicine and environmental sectors. It elaborates on their potential applications, bridging the gap between advancements in the healthcare sector and solutions for environmental issues.
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Background: Tick bites often promote local allergic reactions in the skin and predispose to red meat allergy. The mechanisms involved in these processes are not fully understood. Here we investigated the local changes to the skin and intestine induced by tick bites. Methods: C3H/HEN or Balb/c mice were subjected to either tick bites by Ixodes ricinus ( I. ricinus ) or mechanical skin injury. Skin or intestine was analyzed a different time point by transcriptomic and histological techniques. Results: Our results indicate that I. ricinus bites promote epidermal hyperplasia, spongiosis and an accumulation of eosinophils and mast cells in the bitten skin. In addition, I. ricinus bites promote the expression of genes and activate pathways also induced by mechanical skin injury elicited by tape stripping. Remarkably, similar to tape stripping, I. ricinus bites promote an increase in total serum IgE, and intestinal tuft cell and mast cell expansion. Conclusion: I. ricinus bites in mice promote cutaneous inflammation that resembles allergic skin inflammation, as well as intestinal changes that could play a role in the predisposition to red meat allergy.
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INTRODUCTION: Acne keloidalis nuchae (AKN) is a primary cicatricial alopecia with mixed infiltrate. It is more common in Africans or persons of African descent. OBJECTIVES: Our objective was to describe the epidemiology and clinical and trichoscopic presentations of AKN in a large series of Hispanic patients. METHODS: This was a retrospective study from 10 different dermatological centers in Argentina, Colombia, Mexico, and Peru. Patients with a clinical diagnosis of AKN treated by 12 dermatologists experienced in trichology from 2018 to 2022 were included. The Umar classification system was used to determine severity. RESULTS: We identified 142 patients with AKN: 98% were male (n=140) with a mean age of 32 years; 108 patients had a previous history of trauma to the nuchal area (76%, P < 0.001); and 48 were positive for a history of acne (33.8%, P = 0.021). Patients with >50 months of evolution were mainly classified in classes III and IV compared to patients with an evolution of <50 months (30%, n=9 vs. 14%, n=15; P = 0.019; respectively). CONCLUSION: AKN should be considered in the differential diagnosis in the Hispanic population. Advanced stages of the disease are correlated with chronic evolution.
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Physical trauma disrupts skin barrier function. How the skin barrier recovers is not fully understood. We evaluated in mice the mechanism of skin barrier recovery after mechanical injury inflicted by tape stripping. Tape stripping disrupted skin barrier function as evidenced by increased transepidermal water loss. We show that tape stripping induces IL-1-, IL-23-, and TCRγδ+-dependent upregulation of cutaneous Il17a and Il22 expression. We demonstrate that IL-17A and IL-22 induce epidermal hyperplasia, promote neutrophil recruitment, and delay skin barrier function recovery. Neutrophil depletion improved the recovery of skin barrier function and decreased epidermal hyperplasia. Single-cell RNA sequencing and flow cytometry analysis of skin cells revealed basophil infiltration into tape-stripped skin. Basophil depletion upregulated Il17a expression, increased neutrophil infiltration, and delayed skin barrier recovery. Comparative analysis of genes differentially expressed in tape-stripped skin of basophil-depleted mice and Il17a-/- mice indicated that basophils counteract the effects of IL-17A on the expression of epidermal and lipid metabolism genes important for skin barrier integrity. Our results demonstrate that basophils play a protective role by downregulating Il17a expression after mechanical skin injury, thereby counteracting the adverse effect of IL-17A on skin barrier function recovery, and suggest interventions to accelerate this recovery.
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Basófilos , Interleucina-17 , Interleucinas , Animales , Ratones , Basófilos/inmunología , Interleucina-17/metabolismo , Interleucinas/metabolismo , Interleucinas/genética , Piel/lesiones , Piel/patología , Piel/inmunología , Piel/metabolismo , Ratones Noqueados , Modelos Animales de Enfermedad , Interleucina-22 , Pérdida Insensible de Agua/inmunología , Ratones Endogámicos C57BL , Infiltración Neutrófila , Epidermis/lesiones , Epidermis/patología , Epidermis/inmunología , Epidermis/metabolismo , Recuperación de la Función , FemeninoRESUMEN
The purpose of the systematic review was to synthesize the literature on children's outcomes across different living arrangements (nuclear families, shared physical custody [SPC], lone physical custody [LPC]) by extracting and structuring relevant theoretical hypotheses (selection, instability, fewer resources, and stressful mobility) and comparing the empirical findings against these hypotheses. Following the PRISMA guidelines, the review included 39 studies conducted between January 2010-December 2022 and compared the living arrangements across five domains of children's outcomes: emotional, behavioral, relational, physical, and educational. The results showed that children's outcomes were the best in nuclear families but in 75% of the studies children in SPC arrangements had equal outcomes. Children in LPC tended to report the worst outcomes. When compared with the different theoretical hypotheses, the results were the most consistent with fewer resources hypothesis which suggests that children especially in LPC families have fewer relational and economic resources whereas children in SPC families are better able to maintain resources from both parents.
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Emociones , Núcleo Familiar , Niño , Humanos , Escolaridad , Padres , Examen FísicoRESUMEN
Background/Aims: Motility, stool characteristics, and microbiota composition are expected to modulate probiotics' passage through the gut but their effects on persistence after intake cessation remain uncharacterized. This pilot, open-label study aims at characterizing probiotic fecal detection parameters (onset, persistence, and duration) and their relationship with whole gut transit time (WGTT). Correlations with fecal microbiota composition are also explored. Methods: Thirty healthy adults (30.4 ± 13.3 years) received a probiotic (30 × 109 CFU/capsule/day, 2 weeks; containing Lactobacillus helveticus R0052, Lacticaseibacillus paracasei HA-108, Bifidobacterium breve HA-129, Bifidobacterium longum R0175, and Streptococcus thermophilus HA-110). Probiotic intake was flanked by 4-week washout periods, with 18 stool collections throughout the study. WGTT was measured using 80% recovery of radio-opaque markers. Results: Tested strains were detected in feces ~1-2 days after first intake and persistence after intake cessation was not significantly different for R0052, HA-108, and HA-129 (~3-6 days). We identified 3 WGTT subgroups within this population (named Fast, Intermediate, and Slow), which could be classified by machine learning with high accuracy based on differentially abundant taxa. On average, R0175 persisted significantly longer in the intermediate WGTT subgroup (~8.5 days), which was mainly due to 6 of the 13 Intermediate participants for whom R0175 persisted ≥ 15 days. Machine learning classified these 13 participants according to their WGTT cluster (≥ 15 days or < 5 days) with high accuracy, highlighting differentially abundant taxa potentially associated with R0175 persistence. Conclusion: These results support the notion that host-specific parameters such as WGTT and microbiota composition should be considered when designing studies involving probiotics, especially for the optimization of washout duration in crossover studies but also for the definition of enrollment criteria or supplementation regimen in specific populations.
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Oral nutrition supplements (ONS) are widely recommended for the management of unintentional weight loss in patient populations, long-term care residents, and community-dwelling older adults. Most marketed ONS are ultra-processed, with precision nutrition and aseptic composition, as well as convenience and availability, driving their selection. However, therapeutic effectiveness is mixed and the potential health risks of consuming ultra-processed ONS long-term in lieu of less-processed foods have received little attention. A diverse and balanced microbiota supporting immunity and wellness is maintained by a diet rich in plant-sourced foods. The implications of ultra-processed ONS displacing plant-sourced foods, and specifically the potential for undesirable impacts on the gut microbiota, require consideration. Most ONS are either devoid of fiber or are supplemented with isolated or purified fibers that may contribute to adverse gastrointestinal symptoms and appetite suppression. In contrast, the diversity of microbial-available, nondigestible carbohydrates, together with the array of phytochemicals found in plant-sourced foods, support microbial diversity and its resiliency. This review outlines the clinical dilemma of recommending commercial ultra-processed ONS vs nutritionally adequate (eg, high-energy/high-protein) foods and beverages that contribute to diet quality, maintenance of a diverse and stable gut microbiota composition, and support nutrition status and health. Ultra-processed ONS may fall short of expected health benefits, and overreliance may potentially contribute to the risk for patient and older adult populations because of the displacement of a variety of healthful foods.
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Dieta , Estado Nutricional , Humanos , Anciano , Suplementos Dietéticos/efectos adversos , Pérdida de Peso , Apoyo Nutricional , Comida Rápida , Manipulación de AlimentosRESUMEN
BACKGROUND AND PURPOSE: Stroke incidence and prevalence estimates in developing countries should include stroke cases not presenting to hospital. We performed door-to-door stroke case ascertainment in Durango Municipality, Mexico, to estimate stroke incidence and prevalence and to determine the error made by only ascertaining hospital cases. METHODS: Between September 2008 and March 2009, 1996 housing units were randomly sampled to screen for stroke in Durango Municipality residents 35 years of age and older. Field workers utilized a validated screening tool. Those screening positive were referred to a neurologist for history and examination and a head CT scan. Prevalence and cumulative incidence from the door-to-door surveillance were calculated and compared with previously reported hospitalization rates during the same defined time. RESULTS: Respondents included 2437 subjects from 1419 homes. The refusal rate was 3.8%. Twenty subjects had verified or probable stroke. The prevalence of probable or verified stroke was 7.7 per 1000 (95% CI, 4.3 per 1000-11.2 per 1000). Five patients had a stroke during the time of the hospital surveillance, yielding a cumulative incidence of 232.3 per 100 000 (95% CI, 27.8-436.9). Two of the 5 cases were captured by door-to-door surveillance but not by hospital surveillance. CONCLUSIONS: This study provides the first community-based stroke prevalence and incidence estimates in Mexico. The wide confidence intervals, despite the large number of surveyed housing units, suggest the need for more advanced sampling strategies for stroke surveillance in the developing world.
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Isquemia Encefálica/epidemiología , Encuestas Epidemiológicas/métodos , Vigilancia de la Población/métodos , Accidente Cerebrovascular/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Isquemia Encefálica/diagnóstico , Femenino , Humanos , Incidencia , Masculino , México/epidemiología , Persona de Mediana Edad , Prevalencia , Accidente Cerebrovascular/diagnósticoRESUMEN
Manganese (Mn) oxidation is performed through oxidative Mn-oxidizing bacteria (MnOxb) as the main bio-weathering mechanism for Mn(III/IV) deposits during soil formation. However, with an increase in temperature, the respiration rate also increases, producing Reactive Oxygen Species (ROS) as by-products, which are harmful to microbial cells. We hypothesize that bacterial ROS oxidize Mn(II) to Mn(III/IV) as a secondary non-enzymatic temperature-dependent mechanism for cell protection. Fourteen MnOxb were isolated from Antarctic soils under the global warming effect, and peroxidase (PO) activity, ROS, and Mn(III/IV) production were evaluated for 120 h of incubation at 4 °C, 15 °C, and 30 °C. ROS contributions to Mn oxidation were evaluated in Arthrobacter oxydans under antioxidant (Trolox) and ROS-stimulated (menadione) conditions. The Mn(III/IV) concentration increased with temperature and positively correlated with ROS production. ROS scavenging with Trolox depleted the Mn oxidation, and ROS-stimulant increased the Mn precipitation in A. oxydans. Increasing the Mn(II) concentration caused a reduction in the membrane potential and bacterial viability, which resulted in Mn precipitation on the bacteria surface. In conclusion, bacterial ROS production serves as a complementary non-enzymatic temperature-dependent mechanism for Mn(II) oxidation as a response in warming environments.
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INTRODUCTION: The studies on knowledge, attitudes, and practices (KAP) regarding COVID-19 help to identify erroneous concepts and inadequate practices related to the disease. This baseline information is essential to design effective strategies and improve adherence to prevention measures. OBJECTIVE: To identify the COVID-19-related KAP in Venezuelan patients screened at the Hospital Universitario de Caracas triage tent. MATERIALS AND METHODS: We conducted a cross-sectional study among 215 patients between April 25th and May 25th, 2020, with in-person interviews using a KAP survey. RESULTS: Most surveyed patients (53.5%) were asymptomatic. Most of them, both from the symptomatic and the asymptomatic groups, had adequate knowledge about the symptoms and transmission of the disease and the majority said they were practicing quarantine, frequent handwashing, and the use of face masks in public areas. However, the daily replacement of cloth face masks was more frequent in the asymptomatic group whereas replacement every three days was more frequent in the symptomatic group. Finally, more than half of the participants admitted having been in crowded places, a common practice among the symptomatic compared to the asymptomatic patients. CONCLUSIONS: This is the first KAP study in Venezuela about COVID-19. Knowledge and practices among Venezuelans could be improved by strengthening education and training programs. This information from the early phase of the pandemic in Venezuela may contribute to the design of COVID-19 promotion and prevention strategies.
Introducción: Los estudios sobre conocimientos, actitudes y prácticas (CAP) sobre COVID-19 ayudan a identificar conceptos erróneos y prácticas inadecuadas relacionadas con la enfermedad. Esta información de referencia es fundamental para diseñar estrategias efectivas y mejorar la adherencia a las medidas de prevención. Objetivo: Identificar la CAP relacionada con COVID-19 en pacientes venezolanos cribados en la carpa de triaje del Hospital Universitario de Caracas. Materiales y métodos: Realizamos un estudio transversal entre 215 pacientes entre el 25 de abril y el 25 de mayo de 2020, con entrevistas en persona utilizando una encuesta KAP. Resultados: La mayoría de los pacientes encuestados (53,5%) se encontraban asintomáticos. La mayoría de ellos, tanto del grupo sintomático como asintomático, tenían un conocimiento adecuado sobre los síntomas y la transmisión de la enfermedad y la mayoría dijo que practicaban la cuarentena, el lavado frecuente de manos y el uso de mascarillas en las áreas públicas. Sin embargo, el reemplazo diario de mascarillas de tela fue más frecuente en el grupo asintomático, mientras que el reemplazo cada tres días fue más frecuente en el grupo sintomático. Finalmente, más de la mitad de los participantes admitieron haber estado en lugares concurridos, una práctica común entre los sintomáticos en comparación con los asintomáticos. Conclusiones: Este es el primer estudio CAP en Venezuela sobre COVID-19. El conocimiento y las prácticas entre los venezolanos podrían mejorarse fortaleciendo los programas de educación y capacitación. Esta información de la fase inicial de la pandemia en Venezuela puede contribuir al diseño de estrategias de promoción y prevención del COVID-19.