198 research outputs found
Liprobe, a vital dye for lipid aggregates detection in imaging and high-content screens
Pathological lipid accumulation is a hallmark of several metabolic disorders, and
detection of lipid aggregates is an essential step for initial diagnosis and drug
screening purposes. However, low-cost, simple, and reliable detection
fluorescent probes are not widely available. Here, six push-pull-push dyes
were studied, and proved to be highly sensitive to the polarity of the
medium, presenting potential to distinguish structures with different
hydrophobic indexes. Importantly, in the presence of lipid aggregates their
staining specificity highly increased and the fluorescence wavelength blue
shifted. One of the compounds, named Liprobe, was physiologically inert in
cells, as witnessed by mass-spectrometry and metabolic assays. Liprobe was
not toxic to living zebrafish embryos, and differentially stained the muscle and
bone tissues. In triglyceride solutions, a high correlation was observed between
Liprobe’s 558 and 592 nm emissions and the 0–2.5 mg dl−1 triglyceride range.
Confocal and cell-based high content screens revealed that this fluorophore
was able to selectively detect lipid droplets and ceramide loads in normal and
Farber’s disease human fibroblasts, respectively. Our results demonstrate that
Liprobe is a suitable fluorescing probe for vital staining of lipid aggregates,
compatible with a rapid and cheap high content screening assays for
preliminary diagnosis of Farber’s disease and, potentially, of other lipidosis.publishe
SGLT1 activity in lung alveolar cells of diabetic rats modulates airway surface liquid glucose concentration and bacterial proliferation
High glucose concentration in the airway surface liquid (ASL) is an important feature of diabetes that predisposes to respiratory infections. We investigated the role of alveolar epithelial SGLT1 activity on ASL glucose concentration and bacterial proliferation. Non-diabetic and diabetic rats were intranasally treated with saline, isoproterenol (to increase SGLT1 activity) or phlorizin (to decrease SGLT1 activity); 2 hours later, glucose concentration and bacterial proliferation (methicillin-resistant Sthaphylococcus aureus, MRSA and Pseudomonas aeruginosa, P. aeruginosa) were analyzed in bronchoalveolar lavage (BAL); and alveolar SGLT1 was analyzed by immunohistochemistry. BAL glucose concentration and bacterial proliferation increased in diabetic animals: isoproterenol stimulated SGLT1 migration to luminal membrane, and reduced (50%) the BAL glucose concentration; whereas phlorizin increased the BAL glucose concentration (100%). These regulations were accompanied by parallel changes of in vitro MRSA and P. aeruginosa proliferation in BAL (r = 0.9651 and r = 0.9613, respectively, Pearson correlation). The same regulations were observed in in vivo P. aeruginosa proliferation. In summary, the results indicate a relationship among SGLT1 activity, ASL glucose concentration and pulmonary bacterial proliferation. Besides, the study highlights that, in situations of pulmonary infection risk, such as in diabetic subjects, increased SGLT1 activity may prevent bacterial proliferation whereas decreased SGLT1 activity can exacerbate it.CAPESFederal University of UberlandiaFAPEMIGFAPEALFAPESPFAPEAL fellowshipUniv Fed Alagoas, Inst Biol Sci & Hlth, Alagoas, BrazilUniv Fed Sao Paulo, Dept Physiol, Sao Paulo, BrazilUniv Fed Uberlandia, Natl Reference Ctr Leprosy & Sanit Dermatol, Uberlandia, MG, BrazilUniv Sao Paulo, Inst Biomed Sci, Dept Physiol, Sao Paulo, BrazilUniv Fed Uberlandia, Inst Genet & Biochem, Uberlandia, MG, BrazilUniv Calif Davis, Dept Med Microbiol & Immunol, Davis, CA USAUniv Fed Uberlandia, Inst Biomed Sci, Dept Physiol, Uberlandia, MG, BrazilUniv Fed Sao Paulo, Dept Physiol, Sao Paulo, BrazilFAPESP: 201/04831-1Web of Scienc
The impacts of the early outset of the COVID-19 pandemic on climate change research: implications for policy-making
Since January 2020, the COVID-19 pandemic has dominated the media and exercises pressure on governments worldwide. Apart from its effects on economies, education systems and societies, the pandemic has also influenced climate change research. This paper examines the extent to which COVID-19 has influenced climate change research worldwide during the first wave at the beginning of 2020 and how it is perceived to exploit it in the future. This study utilised an international survey involving those dedicated to climate change science and management research from Academia, Government, NGOs, and international agencies in 83 countries. The analysis of responses encompasses four independent variables: Institutions, Regions, Scientific Areas, and the level of economic development represented by the Human Development Index (HDI). Results show that: (1) COVID-19 modified the way the surveyed researchers work, (2) there are indicators that COVID-19 has already influenced the direction of climate change and adaptation policy implementation, and (3) respondents perceived (explicitly concerning the COVID-19 lockdowns of March-April 2020), that the pandemic has drawn attention away from climate policy. COVID- 19 has influenced the agenda of climate change research for more than half of the respondents and is likely to continue in the future, suggesting that the impacts on their research will still be felt for many years. The paper concludes by outlining critical implications for policy-making
Chemical analysis and evaluation of antioxidant and antimicrobial activities of fruit fractions of Mauritia flexuosa L. f. (Arecaceae)
Background Fruit consumption is currently considered beyond the nutritional aspects because of the important roles in disease prevention and benefits to health. The objective of this study was to characterize the chemical profile and evaluate the antioxidant and antimicrobial properties of different fractions obtained from fruit pulps of Mauritia flexuosa (MFFs). Methods Initially, chloroform, ethyl acetate and ethanol fractions were obtained from the pulps. Quantifications of total phenols and flavonoids were performed using the methods of Folin-Ciocalteu and complexation with aluminum chloride, respectively. Standard samples were used to identify and quantify phenolic acids and flavonoids using high-performance liquid chromatography with a diode-array detector (HPLC-DAD). The antioxidant capacity of the fractions was verified by sequestration of the free radical 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and iron chelating activity. The antimicrobial activity was determined using the microdilution method and the modulating activity was determined using sub-inhibitory concentrations of the fractions in association with antibiotics. Results The chemical analyzes revealed the presence of catechin, caffeic acid, rutin, orientin, quercetin, apigenin, luteolin and kaempferol, where all are present in the ethyl acetate fraction. The fractions exhibited moderate antioxidant and antimicrobial activities against Gram-positive and Candida strains in addition to modulating the activity of conventional antibiotics. The most expressive result was obtained from the association of the chloroform fraction with cefotaxime, which produced a synergistic effect, reducing the minimum inhibitory concentration (MIC) of the antibiotic from 1,024 to 256 μg/mL. Discussion The fractions presented a constitution rich in phenolic compounds, especially flavonoids. The data obtained demonstrated that the fractions presented moderate antioxidant activity by acting both as primary and secondary antioxidants. The fractions presented antimicrobial and antibiotic potentiating activities, being the first record of modulating effect of fractions of this species against the studied microbial strains, but failed in modulating the activity of antifungal drugs, indicating that this plant has the potential to be used in the development of therapeutic alternatives against resistant bacteria. The constitution phenolic the fractions may be responsible for their pharmacological properties in vitro
Optimization of Pathogenicity Tests for Selection of Native Isolates of Entomopathogenic Fungi Isolated from Citrusgrowing Areas of México on Adults ofDiaphorina citriKuwayama (Hemiptera: Liviidae)
Huanglonbing (HLB), es considerado una de las más letales enfermedades de los cítricos alrededor del mundo, y ha alcanzado las principales áreas de producción de limón Mexicano (Citrus latifolia Tanaka) en la costa del pacifico de México. Los productores han iniciado el uso de insecticidas para controlar las poblaciones del psílido asiático de los cítricos, Diaphorina citri Kuwayama (Hemiptera: Liviidae), el vector del patógeno ‘Candidatus Liberibacter asiaticus’ asociado con el HLB. Actualmente los costos de los insecticidas y los efectos secundarios de su uso son las principales preocupaciones, ya que podrían perjudicar la estrategia de manejo contra el vector; y por lo tanto, alternativas ecológicas y económicamente viables a los insecticidas convencionales serian necesarias a corto plazo. Por tanto, el objetivo de este estudio fue evaluar la patogenicidad de 27 aislados nativos y 3 cepas de hongos entomopatógenos para determinar su potencial como agentes de control biológico sobre Diaphorina citri usando 2 diferentes métodos de bioensayo. Los bioensayos fueron realizados bajo condiciones de laboratorio (26 ± 2 °C, 60 ± 5% H.R y 16:8 h L:O) mediante la exposición de insectos adultos a una concentración de 1 × 108 conidios por mililitro utilizando 2 diferentes métodos de aplicación, es decir, por asperjado de esporas en las plántulas de cítricos y por asperjado directo a los psílidos adultos. Los resultados mostraron que para el asperjado directo a los adultos los aislados HIB-24 (B. bassiana) y HIB-32 (I. fumosorosea) mostraron el mayor porcentaje de mortalidad (60.66%). Respecto al asperjado de plántulas el aislado HIB-19 (I. fumosorosea) mostró el mayor porcentaje de mortalidad (62.02%). Los resultados de este estudio demuestran el potencial para el uso de hongos entomopatógenos en el manejo de D. citri en México.
ABSTRACT
Huanglongbing (HLB), considered one of the most lethal diseases of citrus worldwide, has reached the main areas of Mexican lime (Citrus latifolia Tanaka) fruit production on the Pacific coast of México. Growers have initiated intensive use of insecticides in order to control populations of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), the vector of the pathogen, ‘Candidatus Liberibacter asiaticus’ associated with huanglongbing. Presently, costs of insecticides and the side effects of their use are major concerns, because they could impair the management strategy against the vector; and thus, ecologically and economically viable alternatives to conventional insecticides are required in the short term. Therefore the goal of this study was to evaluate the pathogenicity of 27 native isolates and 3 strains of entomopathogenic fungi and determine their potential as biological control agents of D. citri by using 2 different bioassay methods. Bioassays were performed under laboratory conditions (26 ± 2 °C, 60 ± 5% RH and 16:8 h L:D) by exposing adult insects to a concentration of 1 × 108 conidia per milliliter using 2 different application methods, i.e., spraying the spores onto the citrus seedlings and spraying the spores directly onto the adult psyllids. The results showed that by direct spraying the adults, HIB-24 (B. bassiana) and HIB-32 (I. fumosorosea) isolates showed the highest mortality (60.66%). Regarding spraying of the seedlings, HIB-19 (I. fumosorosea) showed the highest percentage of mortality (62.02%). The results from this study demonstrate potential for using entomopathogenic fungi in the management of D. citri in México
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Three Decades and Counting: HIV Service Provision in Outpatient Mental Health Settings
OBJECTIVE: People with serious mental illness in the United States have higher human immunodeficiency virus (HIV) infection rates than the general U.S. population. This study aimed to assess delivery of HIV services in New York State’s outpatient mental health programs. Greater access would enhance efforts to improve HIV prevention and care outcomes.
METHODS: The authors surveyed directors of licensed outpatient mental health care programs statewide to investigate their HIV service delivery. Data were compared with surveys conducted in 1997 and 2004 in order to examine differences in services between geographic regions and time periods.
RESULTS: Outpatient mental health programs have improved in the volume and range of HIV services offered, but their provision of pre-exposure prophylaxis, condoms, HIV testing, and HIV antiretroviral treatment monitoring has lagged.
CONCLUSIONS: New York’s initiative to end the HIV epidemic is not optimized to reach people with serious mental illness in settings designed for their care
The Role of the p38 MAPK Signaling Pathway in High Glucose-Induced Epithelial-Mesenchymal Transition of Cultured Human Renal Tubular Epithelial Cells
Epithelial-mesenchymal transition of tubular epithelial cells, which is characterized by a loss of epithelial cell characteristics and a gain of ECM-producing myofibroblast characteristics, is an essential mechanism that is involved in tubulointerstitial fibrosis, an important component of the renal injury that is associated with diabetic nephropathy. Under diabetic conditions, p38 MAPK activation has been reported in glomeruli and mesangial cells; however, studies on p38 MAPK in TECs are lacking. In this study, the role of p38 MAPK in AP-1 activation and in the EMT in the human proximal tubular epithelial cell line (HK-2) under high glucose concentration conditions is investigated.A vector for small interfering RNA that targets p38 MAPK was constructed; the cells were then either transfected with p38 siRNA or pretreated with a chemical inhibitor of AP-1 and incubated with low glucose plus TGF-β1 or high glucose for 48 h. Cells that were not transfected or pretreated and were exposed to low glucose with or without TGF-β1 or high glucose for 48 h were considered to be the controls. We found that high glucose induced an increase in TGF-β1. And high glucose-induced p38 MAPK activation was inhibited by p38 siRNA (P<0.05). A significant decline in E-cadherin and CK expression and a notable increase in vimentin and α-SMA were detected when exposed to low glucose with TGF-β1 or high glucose, and a significant raise of secreted fibronectin were detected when exposed to high glucose; whereas these changes were reversed when the cells were treated with p38 siRNA or AP-1 inhibitor (P<0.05). AP-1 activity levels and Snail expression were up-regulated under high glucose conditions but were markedly down-regulated through knockdown of p38 MAPK with p38 siRNA or pretreatment with AP-1 inhibitor (P<0.05).This study suggests that p38 MAPK may play an important role in the high glucose-induced EMT by activating AP-1 in tubular epithelial cells
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