Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
Photochem Photobiol Sci ; 23(1): 55-63, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38100056

RESUMO

Accumulation studies have found that adipose-derived stem cell (ADSC) exosomes have anti-oxidant and anti-inflammatory characteristics. The current study verified their therapeutic potential to elucidate mechanisms of ADSC exosome actions in ultraviolet B (UVB) light-induced skin injury. Exosomes were isolated from ADSCs and hypoxic pretreated ADSCs. Next-generation sequencing (NGS) was applied to characterize differential mRNA expression. A UV-induced mice skin injury model was generated to investigate therapeutic effects regarding the exosomes via immunofluorescence and ELISA analysis. Regulatory mechanisms were illustrated using luciferase report analysis and in vitro experiments. The results demonstrated that exosomes from hypoxic pretreated ADSCs (HExos) inhibited UVB light-induced vascular injury by reversing reactive oxygen species, inflammatory factor expression and excessive collagen degradation. NGS showed that HExos inhibits UV-induced skin damage via GLRX5 delivery, while GLRX5 downregulation inhibited the therapeutic effect of HExos on UV-induced skin damage. GLRX5 upregulation increased the protective Exo effect on UV-induced skin and EPC damage by inhibiting ferroptosis, inflammatory cytokine expression and excessive collagen degradation. Therefore, the data indicate that HExos attenuate UV light-induced skin injury via GLRX5 delivery and ferroptosis inhibition.


Assuntos
Exossomos , Ferroptose , Células-Tronco Mesenquimais , Animais , Camundongos , Colágeno , Modelos Animais de Doenças , Exossomos/genética , Exossomos/metabolismo , Hipóxia/metabolismo , Células-Tronco Mesenquimais/metabolismo , Raios Ultravioleta
2.
J Am Acad Dermatol ; 2024 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-38772426

RESUMO

As our knowledge of the harmful effects of ultraviolet radiation continues to evolve, sunscreen remains an integral part of a comprehensive photoprotection strategy against multiple endpoints of ultraviolet-mediated damage. Part 1 of this review covers sunscreen active and additive ingredient properties, mechanisms of action and gaps in coverage. Following an overview of sunscreen's efficacy in protecting against sunburn, photocarcinogenesis, photoaging, pigmentary disorders, and idiopathic photodermatoses, we highlight considerations for product use and selection in children and individuals with skin of color.

3.
Arch Insect Biochem Physiol ; 116(4): e22141, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39137204

RESUMO

Megalurothrips usitatus Bagnall, an important pest of bean plants, is primarily managed with synthetic insecticides. M. usitatus has developed considerable resistance to various insecticides in multiple cowpea-growing areas in Hainan Province, China, posing challenges to its control in the field. Light control technology is a potentially effective physical control method for M. usitatus. The vision of thrips is highly sensitive to UV light, whereas other biological characteristics remain unknown. Therefore, this study evaluated the effects of ultraviolet light on the biological characteristics of M. usitatus. Results showed that the egg, larval, and pupal stages of M. usitatus were significantly shortened, and the emergence rate (79.59%) and adult survival rate (77.95%) were reduced under a devoid of UV light environment (UV-), compared with the full-spectrum light (control treatment group, CK) (p < 0.05). However, the single spawning quantity and total amount of spawning were significantly higher, and the sex ratio (57%) was the highest under UV- (p < 0.05). Single UV light (UV+) only affected the pupation rate. Also, the antioxidant enzymes, polyphenol oxidase, superoxide dismutase (SOD), and peroxidase activities were significantly and negatively correlated with the progression of generations under UV-, whereas catalase and SOD activities were significantly and positively correlated with the progression of generations under UV+. The UV- light conditions significantly interfered with the behavior selection of M. usitatus. The results of this study showed that the adaptability of M. usitatus populations would be greatly reduced in the absence of ultraviolet light, providing a theoretical basis for the control of M. usitatus populations.


Assuntos
Tisanópteros , Raios Ultravioleta , Animais , Tisanópteros/fisiologia , Larva/crescimento & desenvolvimento , Larva/efeitos da radiação , Feminino , Pupa/efeitos da radiação , Pupa/crescimento & desenvolvimento , Masculino , Adaptação Fisiológica
4.
J Toxicol Environ Health A ; 87(13): 533-540, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38660981

RESUMO

Seed conditioning with ultraviolet light (UV-C) might (1) improve crop yield and quality, (2) reduce the use of agrochemicals during cultivation, and (3) increase plant survival in high salinity environments. The aim of this study was to examine the effects of UV-C conditioning of white oat seeds at two doses (0.85 and 3.42 kJ m-2) under salinity stress (100 mM NaCl). Seeds were sown on germination paper and kept in a germination chamber at 20°C. Germination and seedling growth parameters were evaluated after 5 and 10 days. Data demonstrated that excess salt reduced germination and initial growth of white oat seedlings. In all the variables analyzed, exposure of seeds to UV-C under salt stress exerted a positive effect compared to non-irradiated control. The attenuating influence of UV-C in germination was greater at 0.85 than at 3.42 kJ m-2. Thus, data indicate that conditioning white oat seeds in UV-C light produced greater tolerance to salt stress. These findings suggest that UV-C conditioning of white oat seeds may be considered as a simple and economical strategy to alleviate salt-induced stress.


Assuntos
Avena , Germinação , Sementes , Raios Ultravioleta , Avena/efeitos dos fármacos , Avena/efeitos da radiação , Avena/crescimento & desenvolvimento , Sementes/efeitos da radiação , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Germinação/efeitos dos fármacos , Germinação/efeitos da radiação , Estresse Salino/efeitos dos fármacos , Plântula/efeitos da radiação , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Cloreto de Sódio
5.
Int J Mol Sci ; 25(11)2024 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-38891963

RESUMO

Cutaneous field cancerization (CFC) refers to a skin region containing mutated cells' clones, predominantly arising from chronic exposure to ultraviolet radiation (UVR), which exhibits an elevated risk of developing precancerous and neoplastic lesions. Despite extensive research, many molecular aspects of CFC still need to be better understood. In this study, we conducted ex vivo assessment of cell differentiation, oxidative stress, inflammation, and DNA damage in CFC samples. We collected perilesional skin from 41 patients with skin cancer and non-photoexposed skin from 25 healthy control individuals. These biopsies were either paraffin-embedded for indirect immunofluorescence and immunohistochemistry stain or processed for proteins and mRNA extraction from the epidermidis. Our findings indicate a downregulation of p53 expression and an upregulation of Ki67 and p16 in CFC tissues. Additionally, there were alterations in keratinocyte differentiation markers, disrupted cell differentiation, increased expression of iNOS and proinflammatory cytokines IL-6 and IL-8, along with evidence of oxidative DNA damage. Collectively, our results suggest that despite its outwardly normal appearance, CFC tissue shows early signs of DNA damage, an active inflammatory state, oxidative stress, abnormal cell proliferation and differentiation.


Assuntos
Diferenciação Celular , Dano ao DNA , Inflamação , Estresse Oxidativo , Neoplasias Cutâneas , Raios Ultravioleta , Humanos , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/genética , Inflamação/metabolismo , Inflamação/genética , Inflamação/patologia , Masculino , Feminino , Pessoa de Meia-Idade , Raios Ultravioleta/efeitos adversos , Idoso , Queratinócitos/metabolismo , Queratinócitos/patologia , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Adulto , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Pele/metabolismo , Pele/patologia , Pele/efeitos da radiação , Antígeno Ki-67/metabolismo , Antígeno Ki-67/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Inibidor p16 de Quinase Dependente de Ciclina/genética , Interleucina-6/metabolismo , Interleucina-6/genética
6.
Int J Mol Sci ; 25(8)2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38674144

RESUMO

Mammalian melanin is produced in melanocytes and accumulated in melanosomes. Melanogenesis is supported by many factors derived from the surrounding tissue environment, such as the epidermis, dermis, and subcutaneous tissue, in addition to numerous melanogenesis-related genes. The roles of these genes have been fully investigated and the molecular analysis has been performed. Moreover, the role of paracrine factors derived from epidermis has also been studied. However, the role of dermis has not been fully studied. Thus, in this review, dermis-derived factors including soluble and insoluble components were overviewed and discussed in normal and abnormal circumstances. Dermal factors play an important role in the regulation of melanogenesis in the normal and abnormal mammalian skin.


Assuntos
Melaninas , Melanócitos , Melaninas/metabolismo , Melanócitos/metabolismo , Humanos , Animais , Pele/metabolismo , Derme/metabolismo , Epiderme/metabolismo , Melanogênese
7.
J Environ Manage ; 351: 119764, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38100867

RESUMO

Indoor air, especially with suspended particulate matter (PM), can be a carrier of airborne infectious pathogens. Without sufficient ventilation, airborne infectious diseases can be transmitted from one person to another. Indoor air quality (IAQ) significantly impacts people's daily lives as people spend 90% of their time indoors. An industrial-grade air cleaner prototype (filtration + ultraviolet light) was previously upgraded to clean indoor air to improve IAQ on two metrics: particulate matter (PM) and viable airborne bacteria. Previous experiments were conducted to test its removal efficiency on PM and airborne bacteria between the inlet and treated air. However, the longer-term improvement on IAQ would be more informative. Therefore, this research focused on quantifying longer-term improvement in a testing environment (poultry facility) loaded with high and variable PM and airborne bacteria concentrations. A 25-day experiment was conducted to treat indoor air using an air cleaner prototype with intermittent ON and OFF days in which PM and viable airborne bacteria were measured to quantify the treatment effect. The results showed an average of 55% reduction of total suspended particulate (TSP) concentration between OFF days (110 µg/m3) and ON days (49 µg/m3). An average of 47% reduction of total airborne viable bacteria concentrations was achieved between OFF days (∼3200 CFU/m3) and ON days (∼2000 CFU/m3). A cross-validation (CV) model was established to predict PM concentrations with five input variables, including the status of the air cleaner, time (h), ambient temperature, indoor relative humidity, and day of the week to help simulate the air-cleaning effect of this prototype. The model can approximately predict the air quality trend, and future improvements may be made to improve its accuracy.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Humanos , Material Particulado/análise , Poluição do Ar em Ambientes Fechados/prevenção & controle , Poluição do Ar em Ambientes Fechados/análise , Raios Ultravioleta , Melhoria de Qualidade , Bactérias , Monitoramento Ambiental , Poluentes Atmosféricos/análise , Tamanho da Partícula
8.
Wilderness Environ Med ; 35(1_suppl): 45S-66S, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38379474

RESUMO

To provide guidance to medical providers, wilderness users, and travelers, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for treating water in situations where the potability of available water is not assured, including wilderness and international travel, areas impacted by disaster, and other areas without adequate sanitation. The guidelines present the available methods for reducing or eliminating microbiological contamination of water for individuals, groups, or households; evaluation of their effectiveness; and practical considerations. The evidence base includes both laboratory and clinical publications. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians.


Assuntos
Desastres , Medicina Selvagem , Humanos , Sociedades Médicas
9.
Bull Environ Contam Toxicol ; 112(4): 62, 2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38615308

RESUMO

Acetamiprid is a novel nicotinic pesticide widely used in modern agriculture because of its low toxicity and specific biological target properties. The objective of this study was to understand the photolysis pattern of acetamiprid in the water column and elucidate its degradation products and mechanism. It was observed that acetamiprid exhibited different photolysis rates under different light source conditions in pure water, with ultraviolet > fluorescence > sunlight; furthermore, its photolysis half-life ranged from 17.3 to 28.6 h. In addition, alkaline conditions (pH 9.0) accelerated its photolysis rate, which increased with pH. Using gas chromatography-mass spectrometry, five direct photolysis products generated during the exposure of acetamiprid to pure water were successfully separated and identified. The molecular structure of acetamiprid was further analyzed using density functional theory, and the active photodegradation sites of acetamiprid were predicted. The mechanism of the photolytic transformation of acetamiprid in water was mainly related to hydroxyl substitution and oxidation. Based on these findings, a comprehensive transformation pathway for acetamiprid was proposed.


Assuntos
Neonicotinoides , Praguicidas , Nicotina , Agricultura , Água
10.
Medicina (Kaunas) ; 60(1)2024 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-38276066

RESUMO

Introduction: Melanoma, a malignant tumor arising from uncontrolled melanocytic proliferation, commonly found in the skin but capable of affecting extracutaneous sites, ranks fifth among diagnosed oncological entities and is a significant cause of cancer deaths, constituting over 80% of skin cancer mortality. Genetic factors and ultraviolet radiation (UVR) exposure, from both natural and artificial sources, are the primary risk factors. Case Presentation: We reported the case of a 25-year-old female with numerous pigmented nevi and notable changes attributed to extensive indoor tanning sessions. Dermatological examinations and dermoscopic evaluations revealed atypical features in two pigmented nevi, leading to surgical excision. Histopathological and immunohistochemical analyses confirmed a compound nevus in one lesion and superficial spreading melanoma in the other, emphasizing the importance of vigilant follow-up and the correct use of immunohistochemistry. Discussion: Indoor tanning significantly elevates the cutaneous melanoma risk, with initiation before age 35 amplifying the risk by up to 75%, especially in young women. The risk escalates with cumulative sessions, particularly exceeding 480, and individuals undergoing over 30 sessions face a 32% higher risk. UVR induces DNA damage, genetic mutations, and immunosuppression, contributing to oncogenesis. Genetic factors, like the PTCHD2 gene, may influence the tanning dependency. Legislation targeting minors has been enacted globally but only with partial efficacy. Tanning accelerators, though associated with minor side effects, correlate with high-risk behaviors. The case underscores the urgency of addressing indoor tanning risks, emphasizing targeted awareness efforts and legislative improvements. Conclusions: In conclusion, the reported case highlights the increased risk of cutaneous melanoma linked to indoor tanning, particularly among young women and specific sociodemographic groups. Despite legislative measures, challenges persist, suggesting the potential efficacy of online campaigns involving relatable influencers to raise awareness and discourage artificial tanning.


Assuntos
Melanoma , Nevo Pigmentado , Neoplasias Cutâneas , Feminino , Humanos , Adulto , Melanoma/etiologia , Melanoma/patologia , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/patologia , Raios Ultravioleta/efeitos adversos , Pele/patologia , Nevo Pigmentado/complicações
11.
Artigo em Russo | MEDLINE | ID: mdl-38934955

RESUMO

OBJECTIVE: To analyze the effects and tolerability of physiotherapeutic methods with optical radiation (phototherapy) in acute respiratory diseases (ARD) on the basis of the modern scientific literature data and the results of doctors and patients survey. MATERIAL AND METHODS: An analysis of regulatory sources and modern scientific literature on the subject of research, survey of 200 patients with ARD and 100 primary care physicians of the Central Federal District on their sociomedical status and awareness of phototherapeutic treatment methods were conducted. RESULTS: Phototherapy in ARD have demonstrated chromogenic, immunostimulating, photosensitizing, vitamin-forming, trophostimulating, anti-inflammatory, analgesic, desensitizing, bactericidal and mycocidal, metabolic, coagulo-correcting therapeutic effects. Patients and doctors have been insufficiently aware of phototherapy methods and used them in practice relatively rare. A significant proportion of patients had ARD risk factors, namely teamwork, tobacco smoking and chronic diseases. CONCLUSION: 1. The therapeutic effects of all types of phototherapy in acute respiratory infections are interrelated with their etiopathogenesis. 2. Patients and doctors are insufficiently informed and relatively rarely use phototherapy methods. 3. A significant proportion of patients have risk factors for acute respiratory infections: teamwork (88%), tobacco smoking (68%) and chronic diseases (52%).


Assuntos
Fototerapia , Humanos , Fototerapia/métodos , Doença Aguda , Masculino , Feminino , Adulto , Doenças Respiratórias/terapia , Infecções Respiratórias/terapia , Pessoa de Meia-Idade
12.
Front Immunol ; 15: 1384606, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38660315

RESUMO

Introduction: Ultraviolet (UV) light is a known trigger of both cutaneous and systemic disease manifestations in lupus patients. Lupus skin has elevated expression of type I interferons (IFNs) that promote increased keratinocyte (KC) death after UV exposure. The mechanisms by which KC cell death is increased by type I IFNs are unknown. Methods: Here, we examine the specific cell death pathways that are activated in KCs by type I IFN priming and UVB exposure using a variety of pharmacological and genetic approaches. Mice that overexpress Ifnk in the epidermis were exposed to UVB light and cell death was measured. RNA-sequencing from IFN-treated KCs was analyzed to identify candidate genes for further analysis that could drive enhanced cell death responses after UVB exposure. Results: We identify enhanced activation of caspase-8 dependent apoptosis, but not other cell death pathways, in type I IFN and UVB-exposed KCs. In vivo, overexpression of epidermal Ifnk resulted in increased apoptosis in murine skin after UVB treatment. This increase in KC apoptosis was not dependent on known death ligands but rather dependent on type I IFN-upregulation of interferon regulatory factor 1 (IRF1). Discussion: These data suggest that enhanced sensitivity to UV light exhibited by lupus patients results from type I IFN priming of KCs that drives IRF1 expression resulting in caspase-8 activation and increased apoptosis after minimal exposures to UVB.


Assuntos
Caspase 8 , Interferon-alfa , Queratinócitos , Animais , Camundongos , Apoptose , Caspase 8/metabolismo , Caspase 8/genética , Fator Regulador 1 de Interferon/metabolismo , Fator Regulador 1 de Interferon/genética , Interferon-alfa/metabolismo , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Camundongos Endogâmicos C57BL , Raios Ultravioleta/efeitos adversos
13.
Micromachines (Basel) ; 15(6)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38930732

RESUMO

In this study, we propose a polarized electron blocking layer (EBL) structure using AlxGa1-xN/AlxGa1-xN to enhance the internal quantum efficiency (IQE) of AlGaN-based ultraviolet light-emitting diodes (UV LEDs). Our findings indicate that this polarized EBL structure significantly improves IQE compared to conventional EBLs. Additionally, we introduce an electric-field reservoir (EFR) optimization method to maximize IQE. Specifically, optimizing the polarized EBL structure of AlxGa1-xN/AlxGa1-xN enhances the hole drift rate, resulting in an IQE improvement of 19% and an optical output power increase of 186 mW at a current of 210 mA.

14.
Neotrop Entomol ; 53(3): 499-513, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38656591

RESUMO

The use of Meliponini for crop pollination in protected environments is practically non-existent. One of the reasons is the difficulty of acclimatizing Meliponini to the temperature and light conditions inside greenhouses. We investigated how covering materials used in greenhouses, which filter different intensities of ultraviolet (UV) light, affect the foraging behaviors, flight orientation, attraction to walls and ceilings, and mortality of Scaptotrigona cf. postica (Letreille), Frieseomelitta varia (Lepeletier), and Melipona quadrifasciata (Lepeletier). The experiments were conducted in 5.3 m3 arenas covered with four types of plastic films that do not polarize sunlight, with UV transmittance levels ranging from 0.1 to 54%, compared to a transparent glass control. The temperature inside the arenas varied between treatments, from 27 ± 3°C to 31 ± 2°C. All three species collected resources and returned to the colony, regardless of the covering material. However, the proportion of this behavior, the number of bees attracted to the ceiling and wall, and mortality varied among treatments and/or throughout the confinement days for each species. Melipona quadrifasciata and F. varia acclimatized better to the confined environments than S. cf. postica and showed consistent resource collection behavior throughout the confinement days in all tested materials, except for the one that filtered around 90% of UV. In all three species, the mortality gradually decreased throughout the confinement days. The results indicate that the choice of covering material, considering its optical characteristics, can be crucial to ensure greater effectiveness of the pollination services provided by stingless bees in protected systems.


Assuntos
Aclimatação , Raios Ultravioleta , Abelhas/fisiologia , Animais , Brasil , Temperatura , Polinização , Comportamento Alimentar , Voo Animal
15.
Sci Rep ; 14(1): 3386, 2024 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-38336807

RESUMO

During the COVID pandemic caused by the SARS-CoV-2 virus, studies have shown the efficiency of deactivating this virus via ultraviolet light. The damage mechanism is well understood: UV light disturbs the integrity of the RNA chain at those locations where specific nucleotide neighbors occur. In this contribution, we present a model to address certain gaps in the description of the interaction between UV photons and the RNA sequence for virus inactivation. We begin by exploiting the available information on the pathogen's morphology, physical, and genomic characteristics, enabling us to estimate the average number of UV photons required to photochemically damage the virus's RNA. To generalize our results, we have numerically generated random RNA sequences and checked that the distribution of pairs of nucleotides susceptible of damage for the SARS-CoV-2 is within the expected values for a random-generated RNA chain. After determining the average number of photons reaching the RNA for a preset level of fluence (or photon density), we applied the binomial probability distribution to evaluate the damage of nucleotide pairs in the RNA chain due to UV radiation. Our results describe this interaction in terms of the probability of damaging a single pair of nucleotides, and the number of available photons. The cumulative probability exhibits a steep sigmoidal shape, implying that a relatively small change in the number of affected pairs may trigger the inactivation of the virus. Our light-RNA interaction model quantitatively describes how the fraction of affected pairs of nucleotides in the RNA sequence depends on the probability of damaging a single pair and the number of photons impinging on it. A better understanding of the underlying inactivation mechanism would help in the design of optimum experiments and UV sanitization methods. Although this paper focuses on SARS-CoV-2, these results can be adapted for any other type of pathogen susceptible of UV damage.


Assuntos
COVID-19 , Vírus , Humanos , SARS-CoV-2/genética , Raios Ultravioleta , RNA , Inativação de Vírus , Nucleotídeos , Desinfecção/métodos
16.
Polymers (Basel) ; 16(2)2024 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-38276701

RESUMO

The alteration of an ultraviolet light absorber (UVA: UV-326) in polymers (PP, HDPE, LDPE, PLA, and PS) over time during degradation was studied using an enhanced degradation method (EDM) involving sulfate ion radicals in seawater. The EDM was employed to homogeneously degrade the entire polymer samples containing the UVA. The PP and PS samples containing 5-phr (phr: per hundred resin) UVA films underwent rapid whitening, characterized by the formation of numerous grooves or crushed particles. Notably, the UVA loss rate in PS, with the higher glass transition temperature (Tg), was considerably slower. The behavior of crystalline polymers, with the exception of PS, was analogous in terms of the change in UVA loss rate over the course of degradation. The significant increase in the initial loss rate observed during EDM degradation was due to microplasticization. A similar increase in microplasticization rate occurred with PS; however, the intermolecular interaction between UVA and PS did not result in as pronounced an increase in loss rate as observed in other polymers. Importantly, the chemical structure of UVA remained unaltered during EDM degradation. These findings revealed that the primary cause of UVA loss was leaching from the polymer matrix.

17.
Life Sci Space Res (Amst) ; 41: 56-63, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38670653

RESUMO

The prevention and reduction of microbial species entering and leaving Earth's biosphere is a critical aspect of planetary protection research. While various decontamination methods exist and are currently utilized for planetary protection purposes, the use of far-UVC light (200-230 nm) as a means for microbial reduction remains underexplored. Unlike conventional germicidal ultraviolet at 254 nm, which can pose a health risk to humans even with small exposure doses, far-UVC light poses minimal health hazard making it a suitable candidate for implementation in occupied areas of spacecraft assembly facilities. This study investigates the efficacy of far-UVC 222-nm light to inactivate bacteria using microbial species which are relevant to planetary protection either in vegetative cell or spore form. All the tested vegetative cells demonstrated susceptibility to 222-nm exposure, although susceptibility varied among the tested species. Notably, Deinococcus radiodurans, a species highly tolerant to extreme environmental conditions, exhibited the most resistance to far-UVC exposure with a dose of 112 mJ/cm2 required for a 1-log reduction in survival. While spore susceptibility was similar across the species tested, Bacillus pumilus spores were the most resistant of the tested spores when analyzed with a bi-exponential cell killing model (D90 of 6.8 mJ/cm2). Overall, these results demonstrate the efficacy of far-UVC light for reducing microbial bioburden to help ensure the success and safety of future space exploration missions.


Assuntos
Astronave , Esporos Bacterianos , Raios Ultravioleta , Esporos Bacterianos/efeitos da radiação , Extremófilos/fisiologia , Extremófilos/efeitos da radiação , Deinococcus/efeitos da radiação , Deinococcus/fisiologia , Desinfecção/métodos
18.
Artigo em Inglês | MEDLINE | ID: mdl-38389933

RESUMO

Photosensitivity to structurally diverse drugs is a common but under-reported adverse cutaneous reaction and can be classified as phototoxic or photoallergic. Phototoxic reactions occur when the skin is exposed to sunlight after administering topical or systemic medications that exhibit photosensitizing activity. These reactions depend on the dose of medication, degree of exposure to ultraviolet light, type of ultraviolet light, and sufficient skin distribution volume. Accurate prediction of the incidence and phototoxic response severity is challenging due to a paucity of literature, suggesting that phototoxicity may be more frequent than reported. This paper reports an extensive literature review on phototoxic drugs; the review employed pre-determined search criteria that included meta-analyses, systematic reviews, literature reviews, and case reports freely available in full text. Additional reports were identified from reference sections that contributed to the understanding of phototoxicity. The following drugs and/or drug classes are discussed: amiodarone, voriconazole, chlorpromazine, doxycycline, fluoroquinolones, hydrochlorothiazide, nonsteroidal anti-inflammatory drugs, and vemurafenib. In reviewing phototoxic skin reactions, this review highlights drug molecular structures, their reactive pathways, and, as there is a growing association between photosensitizing drugs and the increasing incidence of skin cancer, the consequential long-term implications of photocarcinogenesis.

19.
Biomed Pharmacother ; 173: 116278, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38401513

RESUMO

Riboflavin (RF) as a photosensitizer has been used in corneal surgery and the inactivation of blood products. However, the effect of RF on immune cells after ultraviolet (UV) light stimulation has not been investigated. This study pioneered a novel application method of RF. Firstly, UV-stimulated RF was co-cultured with human peripheral blood mononuclear cells in vitro, and the apoptosis rate of lymphocyte subsets, cell proliferation inhibition rate and concentrations of IL-1ß, IL-6, IL-10, TNF-α were assessed. UV-stimulated RF was then administered intravenously to mice via the tail vein for a consecutive period of 5 days. The levels of immunoglobulin (IgG, IgM, IgA), complement (C3, C4) and cytokines (IFN-γ, IL-4, IL17, TGF-ß) were detected by ELISA. Flow cytometry was employed to analyze the populations of CD3+T, CD4+T, CD8+T and CD4+T/CD8+T cells in spleen lymphocytes of mice. The data showed that UV-stimulated RF can effectively induce apoptosis in lymphocytes, and different lymphocyte subtypes exhibited varying degrees of treatment tolerance. Additionally, the proliferative capacity of lymphocytes was suppressed, while their cytokine secretion capability was augmented. The animal experiments demonstrated that UV-stimulated RF led to a significant reduction observed in serum immunoglobulin and complement levels, accompanied by an elevation in IFN-γ, IL-17 and TGF-ß levels, as well as a decline in IL-4 level. In summary, the results of both in vitro and in vivo experiments have demonstrated that UV-stimulated RF, exhibits the ability to partially inhibit immune function. This novel approach utilizing RF may offer innovative perspectives for diseases requiring immunosuppressive treatment.


Assuntos
Interleucina-4 , Leucócitos Mononucleares , Humanos , Camundongos , Animais , Interleucina-4/farmacologia , Camundongos Endogâmicos BALB C , Citocinas/farmacologia , Riboflavina/farmacologia , Fator de Crescimento Transformador beta/farmacologia , Imunoglobulinas/farmacologia , Linfócitos T CD4-Positivos
20.
J Agric Food Chem ; 72(25): 14294-14301, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38874060

RESUMO

Enzymatic browning in fruits and vegetables, driven by polyphenol oxidase (PPO) activity, results in color changes and loss of bioactive compounds. Emerging technologies are being explored to prevent this browning and ensure microbial safety in foods. This study assessed the effectiveness of pulsed light (PL) and ultraviolet light-emitting diodes (UV-LED) in inhibiting PPO and inactivating Escherichia coli ATTC 25922 in fresh apple juice (Malus domestica var. Red Delicious). Both treatments' effects on juice quality, including bioactive compounds, color changes, and microbial inactivation, were examined. At similar doses, PL-treated samples (126 J/cm2) showed higher 2,2- diphenyl-1-picrylhydrazyl inhibition (9.5%) compared to UV-LED-treated samples (132 J/cm2), which showed 1.06%. For microbial inactivation, UV-LED achieved greater E. coli reduction (>3 log cycles) and less ascorbic acid degradation (9.4% ± 0.05) than PL. However, increasing PL doses to 176 J/cm2 resulted in more than 5 log cycles reduction of E. coli, showing a synergistic effect with the final temperature reached (55 °C). The Weibull model analyzed survival curves to evaluate inactivation kinetics. UV-LED was superior in preserving thermosensitive compounds, while PL excelled in deactivating more PPO and achieving maximal microbial inactivation more quickly.


Assuntos
Catecol Oxidase , Escherichia coli , Sucos de Frutas e Vegetais , Malus , Viabilidade Microbiana , Raios Ultravioleta , Catecol Oxidase/metabolismo , Malus/química , Escherichia coli/efeitos da radiação , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/microbiologia , Viabilidade Microbiana/efeitos da radiação , Irradiação de Alimentos/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA