Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 181
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Nitric Oxide ; 144: 11-19, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38185241

RESUMO

The literature is conflicting regarding salivary nitrite (NO2-)/nitrite and nitrate (NO2- and NO3-) levels in children affected by dental caries. For this reason, a systematic review to provide a consensus on the subject was propose, whose objective is to verify whether these molecules could be used as biomarkers in children with caries. A comprehensive search was performed on online database and eleven articles were included in the meta-analysis. The methodological quality of studies was assessed by Newcastle-Ottawa Scale recommended for case-control studies and by AXIS tool for cross-sectional studies. Grading of Recommendations Assessment, Development and Evaluation was used for the assessment of the certainty of the evidence for each outcome. The results showed lower NO2- levels in the group of children affected by dental caries (SMD = -2.18 [-3.24, -1.13], p < 0.01). Age, saliva collection and methods of evaluation can impact the results. When evaluating the severity of the condition, an important variation was detected in relation to the different evaluation methods NO2-/NO2- and NO3-. In conclusion, based on the evidence presented, the results suggest that NO2- levels in saliva are a possible biomarker of dental caries. Results should be evaluated with caution due to the very low evidence from primary studies. Longitudinal studies are necessary to strengthen this hypothesis.


Assuntos
Biomarcadores , Cárie Dentária , Nitratos , Nitritos , Saliva , Humanos , Cárie Dentária/metabolismo , Cárie Dentária/diagnóstico , Saliva/química , Saliva/metabolismo , Biomarcadores/metabolismo , Biomarcadores/análise , Criança , Nitratos/análise , Nitratos/metabolismo , Nitritos/análise , Nitritos/metabolismo
2.
J Pharmacol Sci ; 155(4): 131-139, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38880547

RESUMO

Elevation of the homocysteine concentration in the plasma called hyperhomocysteinemia (hHCY) during pregnancy causes a number of pre- and postnatal developmental disorders. The aim of our study was to analyze the effects of H2S donors -NaHS and N-acetylcysteine (NAC) on blood-brain barrier (BBB) permeability in rats with prenatal hHCY. In rats with mild hHCY BBB permeability assessed by Evans Blue extravasation in brain increased markedly throughout life. Administration of NaHS or NAC during pregnancy attenuated hHCY-associated damage and increased endogenous concentrations of sulfides in brain tissues. Acute application of dl-homocysteine thiolactone induced BBB leakage, which was prevented by the NMDA receptor antagonist MK-801 or H2S donors. Rats with hHCY demonstrated high levels of NO metabolite - nitrites and proinflammatory cytokines (IL-1ß, TNF-α, IL-6) in brain. Lactate dehydrogenase (LDH) activity in the serum was higher in rats with hHCY. Mitochondrial complex-I activity was lower in brain of hHCY rats. NaHS treatment during pregnancy restored levels of proinflammatory cytokines, nitrites and activity of the respiratory chain complex in brain as well as the LDH activity in serum. Our data suggest that H2S has neuroprotective effects against prenatal hHCY-associated BBB disturbance providing a potential strategy for the prevention of developmental impairments in newborns.


Assuntos
Acetilcisteína , Barreira Hematoencefálica , Citocinas , Sulfeto de Hidrogênio , Hiper-Homocisteinemia , Fármacos Neuroprotetores , Animais , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Gravidez , Hiper-Homocisteinemia/metabolismo , Feminino , Sulfeto de Hidrogênio/metabolismo , Fármacos Neuroprotetores/farmacologia , Acetilcisteína/farmacologia , Citocinas/metabolismo , Homocisteína/sangue , Homocisteína/metabolismo , Homocisteína/análogos & derivados , Ratos Wistar , Sulfetos/farmacologia , Sulfetos/administração & dosagem , Ratos , Masculino , Complicações na Gravidez , Encéfalo/metabolismo , L-Lactato Desidrogenase/metabolismo , L-Lactato Desidrogenase/sangue , Permeabilidade , Nitritos/metabolismo , Nitritos/sangue
3.
Dokl Biol Sci ; 516(1): 50-54, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38700814

RESUMO

The content of membrane-bound methemoglobin (MtHb) in nucleated erythrocytes was studied in the black scorpionfish Scorpaena porcus (Linnaeus, 1758) in vitro. Spectral characteristics were determined for a whole hemolysate, a hemolysate obtained by stroma precipitation (a clarified hemolysate), and a resuspended stroma. The MtHb proportion in the erythrocyte stroma was found to exceed 80% (6.20 ± 0.59 µM). Clarified hemolysates were nearly free of MtHb (0.5 ± 0.2 µM). Membrane-bound ferric hemoglobin did not affect the erythrocyte resistance to osmotic shock. The osmotic fragility range was determined using a LaSca-TM laser microparticle analyzer (BioMedSystems, Russia) to be 102-136 mOsm/kg, much the same as in other bony fish species. A nitrite load (10 mg/L) significantly increased the MtHb content in the blood. However, the membrane-bound ferric hemoglobin content did not change significantly, amounting to 6.34 ± 1.09 µM (approximately 95%). The finding suggested a functional importance for MtHb present in the plasma membrane of nucleated erythrocytes. Membrane-bound MtHb was assumed to neutralize the external oxidative load and the toxic effect of hydrogen sulfide in bottom water layers, where the species lives.


Assuntos
Metemoglobina , Perciformes , Animais , Metemoglobina/metabolismo , Perciformes/metabolismo , Perciformes/sangue , Hemoglobinas/metabolismo , Fragilidade Osmótica , Membrana Eritrocítica/metabolismo , Membrana Eritrocítica/efeitos dos fármacos , Eritrócitos/metabolismo , Eritrócitos/efeitos dos fármacos , Eritroblastos/metabolismo , Peixes/metabolismo , Peixes/sangue
4.
Artigo em Chinês | MEDLINE | ID: mdl-38677993

RESUMO

Nitrite has high toxicity and is commonly found in food poisoning. Poisoned patients may experience cyanosis of the skin and lips, nausea, vomiting, and difficulty breathing or coma may occur in severe cases. Four cases of nitrite poisoning patients who were transferred from primary hospitals to the Third Affiliated Hospital of Gansu University of Chinese Medicine, the First People's Hospital of Baiyin were reported. After symptomatic supportive treatment with special antidote methylene blue, oxygen inhalation, blood purification, etc., the patients recovered and were discharged after 4 days of treatment.


Assuntos
Doenças Transmitidas por Alimentos , Nitritos , Humanos , Masculino , Adulto , Feminino , Nitritos/intoxicação , Pessoa de Meia-Idade
5.
Am J Emerg Med ; 64: 204.e5-204.e7, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36369048

RESUMO

BACKGROUND: Alkyl nitrite analogs known as "poppers" have been inhaled recreationally for decades. They are available to be purchased from gas stations marketed as "nail polish remover not for human consumption". These rapid-onset, short-acting, vasodilators cause the user to experience euphoria, dizziness, tachycardia and flushing. While chronic use may lead to problems such as methemoglobinemia or neuropathy, nitrites rarely lead to acute life-threatening side effects such as ventricular dysrhythmias. CASE REPORT: We report a case of ventricular fibrillation cardiac arrest in a 21-year-old male after inhaling from a solution labeled to contain isobutyl nitrite, a rarely reported adverse effect of "popper" use. The product was analytically confirmed to contain mainly isobutyl alcohol, volatile hydrocarbons, and isobutyl nitrite, as well as smaller quantities of other substances. The patient was also prescribed escitalopram and hydroxyzine may have contributed. Return of spontaneous circulation was achieved in the field after initiation of CPR and defibrillation. He was found to have no clear predisposition to arrythmias during his care or on follow up. CONCLUSION: Alkyl nitrite "popper" users and clinicians should be aware that products labeled to contain nitrites may contain volatile hydrocarbons along with nitrites and have the potential to cause arrhythmia.


Assuntos
Nitritos , Fibrilação Ventricular , Masculino , Humanos , Adulto Jovem , Adulto , Fibrilação Ventricular/induzido quimicamente , Fibrilação Ventricular/terapia , Arritmias Cardíacas/induzido quimicamente
6.
Sensors (Basel) ; 22(2)2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35062404

RESUMO

In aquaculture, the density of fish stock, use of feeding, and surrounding environmental conditions can easily result in an excessive concentration of harmful compounds that require continuous monitoring. Chemical sensors are available for most of these compounds, however, operative conditions and continuous monitoring in water make the development of sensors suitable for long and unattended deployments difficult. A possible solution is the development of engineered automatic labs where the uptake of sample and the contact with water is reduced and the use of a minimal quantity of reagents enables the implementation of reliable chemical assays. In this paper, a platform for automatic chemical assays is presented. The concept is demonstrated with the detection of nitrites based on the well-known colorimetric Griess reaction. The platform is centered around a lab-on-a-chip where reagents and water samples are mixed. The color of the reaction product is measured with low-cost optoelectronic components. Results show the feasibility of the approach with a minimum detectable concentration of about 0.1 mg/L which is below the tolerance level for aquaculture farms.


Assuntos
Nitritos , Poluentes Químicos da Água , Animais , Aquicultura , Colorimetria , Dispositivos Lab-On-A-Chip , Nitritos/análise , Poluentes Químicos da Água/análise
7.
Inflammopharmacology ; 30(6): 2285-2300, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36138303

RESUMO

Pterostilbene is a stilbene flavonoid that occurs naturally in various plants as well as produced by genetic engineering. It exhibits anti-inflammatory, analgesic, anti-oxidant and neuroprotective activities. This research was aimed to determine the potential of pterostilbene against arthritis and peripheral neuropathy in Complete Freund's Adjuvant (CFA) induced arthritis. Rat hind paw was injected with 0.1 ml CFA to induce arthritis. Standard control animals received oral methotrexate (3 mg/kg/week). Pterostilbene at 12.5, 25 and 50 mg/kg was given orally to different groups of arthritic rats from day 7-28 for 21 days. Pterostilbene significantly reduced paw diameter and retarded the decrease in body weight of arthritic rats. It profoundly (p < 0.05-0.0001) reduced lipid peroxidation and nitrites, while increased superoxide dismutase (SOD) in the liver tissue. Pterostilbene treatment significantly (p < 0.0001) reduced TNF-α and IL-6 levels. Pterostilbene markedly improved (p < 0.05-0.001) motor activity and showed analgesic effect in arthritic rats at 25 and 50 mg/kg as compared to disease control rats. Furthermore, it notably (p < 0.05-0.0001) increased SOD activity, nitrites, noradrenaline and serotonin levels in the sciatic nerve of arthritic rats. Treatment with pterostilbene also ameliorated the CFA-induced pannus formation, cartilage damage and synovial hyperplasia in the arthritic rat paws. It is determined from the current study that pterostilbene was effective in reducing CFA-induced arthritis in rats through amelioration of oxidative stress and inflammatory mediators. It was also effective to treat peripheral neuropathy through modulation of oxidative stress and neurotransmitters in sciatic nerves.


Assuntos
Artrite Experimental , Doenças do Sistema Nervoso Periférico , Estilbenos , Animais , Ratos , Analgésicos/farmacologia , Artrite Experimental/tratamento farmacológico , Artrite Experimental/induzido quimicamente , Citocinas , Adjuvante de Freund , Neurotransmissores/farmacologia , Nitritos , Estresse Oxidativo , Ratos Wistar , Estilbenos/farmacologia , Superóxido Dismutase
8.
Environ Monit Assess ; 194(10): 720, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36056178

RESUMO

Tropical estuaries are productive dynamic ecosystems where water quality is mediated by physicochemical and biological processes and by fluvial and anthropogenic discharges. The objective of the study was to determine the influence of environmental variables on the spatiotemporal dynamics of water quality in Buenaventura Bay, which is a highly impacted estuary. Sampling was carried out during the dry and rainy season, at three depths, in four stations that represent the environmental gradient of the bay. Temperature, total dissolved solids, salinity, dissolved oxygen, and pH were determined for each sample. In addition, alkalinity, phosphates, nitrites, and nitrates as indicators of water quality were also measured. The estuary was classified as meso- and polyhaline, with appropriate oxygen and pH conditions and spatiotemporal gradients of temperature and solids mediated by river discharges. Significant variations were found in the physicochemical variables by season, with maximum salinity, pH, and solids in the dry season and oxygen and temperature in the rainy season. Likewise, most of these environmental variables were higher in the outer zone of the estuary and lower in the inner stations. Alkalinity and nitrite values were within the permitted ranges, while phosphates and nitrates indicated low water quality. There was a significant direct influence of temperature and oxygen on alkalinity and nitrites. However, for phosphates, no significant influence of environmental variables was found, suggesting a greater influence by fluvial and anthropogenic discharges, which produce a decrease in the environmental quality of the estuary.


Assuntos
Nitritos , Qualidade da Água , Baías , Colômbia , Ecossistema , Monitoramento Ambiental , Estuários , Nitratos/análise , Nitritos/análise , Compostos Orgânicos , Oxigênio/análise , Fosfatos/análise , Rios , Estações do Ano
9.
Biophysics (Oxf) ; 67(5): 816-834, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36567971

RESUMO

This paper describes the gangliopexy method, a method for creating a new center of local neurohumoral regulation, based on the formation of new connections discovered between the nervous system and the vascular system. The prospects for the development of this method are studied. At the same time, novel concepts about the cycles of nitric oxide and the superoxide anion radical are introduced. A possible role of these cycles is examined in the protection of cells and the body as a whole against oxidative and nitrosative stress, which develops when (in 5-30% of cases) destructive changes in the displaced ganglion lead to vascular complications and an increased risk of mortality. Mechanisms that can protect nerve cells, prevent the development of destructive changes in these cells and reduce the risk of mortality are also investigated.

10.
J Environ Manage ; 281: 111872, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33387738

RESUMO

The application of magnetic sorption to treat wastewaters is nowadays seen as a potential industrial method. In this work we apply magnetite particles to remediate real wastewater samples, with several contaminants competing for the same active sorption center at the same time. We also apply our studies at three different sampling points of a Wastewater Treatment Plant. In general terms, magnetite particles have shown a very good behaviour concerning the reduction of detergents and COD, while phosphates and total nitrogen, and the majority of heavy metals are high to moderately removed. The influence of the type of wastewater (i.e., sampling point) has also shown to be important especially for high concentration of contaminants.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Purificação da Água , Fenômenos Magnéticos , Eliminação de Resíduos Líquidos , Águas Residuárias , Poluentes Químicos da Água/análise
11.
Molecules ; 26(11)2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073447

RESUMO

Food preservatives such as NaNO2, which are widely used in human food products, undoubtedly affect, to some extent, human organs and health. For this reason, there is a need to reduce the hazards of these chemical preservatives, by replacing them with safe natural bio-preservatives, or adding them to synthetic ones, which provides synergistic and additive effects. The Citrus genus provides a rich source of such bio-preservatives, in addition to the availability of the genus and the low price of citrus fruit crops. In this study, we identify the most abundant flavonoids in citrus fruits (hesperidin) from the polar extract of mandarin peels (agro-waste) by using spectroscopic techniques, as well as limonene from the non-polar portion using GC techniques. Then, we explore the synergistic and additive effects of hesperidin from total mandarin extract with widely used NaNO2 to create a chemical preservative in food products. The results are promising and show a significant synergistic and additive activity. The combination of mandarin peel extract with NaNO2 had synergistic antibacterial activity against B. cereus, Staph. aureus, E. coli, and P. aeruginosa, while hesperidin showed a synergistic effect against B. cereus and P. aeruginosa and an additive effect against Staph. aureus and E. coli. These results refer to the ability of reducing the concentration of NaNO2 and replacing it with a safe natural bio-preservative such as hesperidin from total mandarin extract. Moreover, this led to gaining benefits from their biological and nutritive values.


Assuntos
Antibacterianos/análise , Citrus/química , Contaminação de Alimentos/prevenção & controle , Hesperidina/química , Nitrito de Sódio/química , Antioxidantes/análise , Bacillus cereus , Sinergismo Farmacológico , Escherichia coli , Flavonoides/química , Conservantes de Alimentos , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Pseudomonas aeruginosa , Staphylococcus aureus
12.
Acta Chir Plast ; 63(4): 185-189, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35042362

RESUMO

Inhalation injury is a serious complication in patients with burns that dramatically increases their morbidity and mortality. These patients are always suspected of having inhalation injury with potential intoxication. We usually encounter carbon monoxide intoxication, but it is necessary to think about the possibility of poisoning by other combustion products. Cyanide intoxications are less common, but their diagnosis and treatment are more complicated. The diagnosis can only be based on the history, clinical findings, and indirect laboratory signs. Direct determination of plasma cyanide levels is not generally adopted in routine clinical practice. Nowadays, several specific antidotes with different mechanisms of action are available. There are no clear guidelines on the antidote of choice, as the evidence base is limited by a lack of randomised controlled trials in humans. In two mini case reports, we present our experience with the diagnosis and therapy of patients with suspected cyanide poisoning.


Assuntos
Queimaduras , Lesão Pulmonar , Antídotos , Cianetos , Humanos , Hidroxocobalamina
13.
Appl Microbiol Biotechnol ; 104(22): 9607-9617, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33044600

RESUMO

Mycelial adhesion affects cell growth and the production of water-soluble extracellular yellow pigment (EYP) in submerged fermentation with Monascus ruber CGMCC 10910. Two nitrates, NaNO3 and KNO3, were used as nitrogen sources for mitigating mycelial adhesion and improving the production of EYP in this study. The results showed that the adhesion of mycelia in the fermentation broth significantly decreased by adding 5 g/L NaNO3, which prevented mycelia from attaching to the inner wall of the Erlenmeyer flask. It was suggested that NaNO3 reduced the total amount of extracellular polysaccharides, increased extracellular proteins, and decreased the viscosity of the fermentation broth. Scanning electron microscopy (SEM) analysis revealed that the mycelial morphology was shorter and more dispersed and vigorous under NaNO3 conditions than under the control conditions. The biomass increased by 49.2% and 45.4% with 5 g/L NaNO3 and 6 g/L KNO3 treatment, respectively, compared with that of the control, and the maximum production of EYP was 267.1 and 241.8 AU350, which increased by 70.0% and 53.9% compared with that of the control, respectively. Simultaneously, the ratios of intracellular yellow pigment to orange pigment increased significantly with 5 g/L of NaNO3 addition (p < 0.05). Genetic analysis found that the expression levels of the key genes for Monascus pigment biosynthesis were significantly upregulated by NaNO3 addition (p < 0.05 or p < 0.01). This study provides an effective strategy for the production of water-soluble Monascus yellow pigments.Key Points• Nitrate addition decreased mycelial adhesion and improved cell growth in Monascus pigment fermentation.• The biosynthesis genes of water-soluble extracellular yellow pigment (EYP) were upregulated by nitrate addition.• The mycelial morphology was significantly influenced to enhance EYP biosynthesis with nitrate addition.


Assuntos
Monascus , Fermentação , Monascus/metabolismo , Nitratos , Pigmentação , Pigmentos Biológicos/metabolismo
14.
Wiad Lek ; 73(6): 1237-1240, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32723960

RESUMO

OBJECTIVE: The aim of the study was to analyze the associations between 4a/4b polymorphism of the eNOS gene and impaired systemic hemodynamics in premature infants with early neonatal sepsis. PATIENTS AND METHODS: Materials and methods: We conducted a prospective cohort study, which included 120 premature babies with early neonatal sepsis, in 57 children the course of the disease was accompanied by arterial hypotension (AH) and in 61 children - not. In children of both groups, genotyping was performed to determine 4a/4b polymorphism of the eNOS gene. RESULTS: Results: It was shown that the heart rate, blood pressure, hourly diuresis, the level of total nitrates and nitrites in the urine, as well as a number of echocardioscopic and dopplerometric indicators in children with different eNOS gene genotypes are not different. CONCLUSION: Conclusions: There is no effect of 4a/4b polymorphism of the eNOS gene on the occurrence of hemodynamic disturbances in premature infants with sepsis.


Assuntos
Infecções Bacterianas , Polimorfismo Genético , Criança , Predisposição Genética para Doença , Genótipo , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Estudos Prospectivos
15.
Molecules ; 24(9)2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31052163

RESUMO

The n-butanolic extract, from an Iranian specimen of Nepeta asterotricha Rech. f. (NABE), displayed anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated J774A.1 macrophages, which reduced nitrites and cytokines production. Bioassay guided fractionation of the extract led to the isolation of four iridoid glycosides, including a new one known as nepetamoside (1), one hexenyl-diglycoside, and some polyphenol and flavonoid components. None of the isolated iridoid components displayed significant effects on nitrites formation in an in vitro LPS-induced model of inflammation, thus suggesting that the plant anti-inflammatory effect is probably due to a synergistic action among its constituents.


Assuntos
Nepeta/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Fracionamento Químico , Citocinas/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Análise Espectral
16.
J Sci Food Agric ; 99(14): 6608-6619, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31347167

RESUMO

BACKGROUND: Understanding plant responses to light quantity in indoor horticultural systems is important for optimising lettuce growth and metabolism as well as energy utilisation efficiency. Light intensity and photoperiod sufficient for normal plant growth parameters might be not efficient for nitrate assimilation. Therefore, this study explored and compared the effects of different light intensities (100-500 µmol m-2 s-1 ) and photoperiods (12-24 h) on the growth and nitrate assimilation in red and green leaf lettuce (Lactuca sativa L.). RESULTS: For efficient nitrate assimilation, 300-400 µmol m-2 s-1 photosynthetic photon flux density (PPFD) and 16-18 h photoperiod is necessary for red and green lettuces. The insufficient light quantity resulted in reduced growth and remarkable increase in nitrate and nitrite contents in both cultivars. Short photoperiods, similarly to low PPFD, growth parameters, chlorophyll indices and nitrate assimilation indices showed the shortage of photosynthetic products for normal plant physiological processes. Short photoperiods had the least pronounced effect on nitrate and nitrite contents in lettuce leaves. CONCLUSION: Light intensity was superior compared to photoperiods for efficient nitrate assimilation in both lettuce cultivars. Under short photoperiods, similarly to low intensity, growth parameters, chlorophyll index and nitrate assimilation indices showed a shortage of photosynthetic products for normal physiological processes. The free amino acid concentration increased, but it was not efficiently incorporated in proteins, as their level in lettuce was lower compared to those for moderate photoperiods. © 2019 Society of Chemical Industry.


Assuntos
Lactuca/metabolismo , Lactuca/efeitos da radiação , Nitratos/metabolismo , Clorofila/análise , Clorofila/metabolismo , Cor , Lactuca/química , Lactuca/crescimento & desenvolvimento , Luz , Nitratos/análise , Nitritos/análise , Nitritos/metabolismo , Fotoperíodo , Fotossíntese , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação
17.
AIDS Behav ; 22(4): 1395-1409, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29248970

RESUMO

The use of stimulant drugs alone or in combination with amyl nitrites (stimulant/nitrites) has been associated with higher rates of risky sexual behavior and predictive of HIV infection among men who have sex with men. However, the temporal pattern of stimulant/nitrite use pre- and post-seroconversion has not been well established. This study assessed changes in stimulant/nitrite use and risky sexual behavior among seroconverting MSM over time. Data were collected in the Baltimore-Washington, DC; Pittsburgh; Chicago; and Los Angeles sites of the Multicenter AIDS Cohort Study (MACS), a longitudinal study of the natural history of HIV infection among MSM. We used propensity scores to select 1044 MSM from 7087 MACS participants composed of 348 seroconverting, 348 seronegative, and 348 seroprevalent participants matched on demographics, recruitment cohort, and study visits. We centered up to four-years of semi-annual data around the seroconversion visit of the seroconverting case within each matched group of participants. Mixed effects regressions estimated the effects of serostatus, recruitment cohort, and time on self-reported stimulant/nitrite use, numbers of male intercourse partners, and numbers of unprotected receptive anal intercourse (URAI) partners. Covariates included demographics, binge drinking, and marijuana use. Seroconverters had the highest odds of stimulant/inhaled nitrite use (AOR 10.3, CI 4.8-22.0), incident rates of intercourse (IRR 1.6, CI 1.3-2.1), and URAI partners (IRR 5.1, CI 3.5-7.3). All participants decreased drug use and sexual risk behavior over time. However, the decreases were largest for seroconverters who nevertheless maintained the highest rates of stimulant/nitrite use and sexual risk. Cohort-related effects were associated with sharp reductions in stimulant/nitrite use and URAI in the early 1990s that rebounded considerably within the first decade of the 2000s. Although all participants decreased risky sexual behavior and stimulant and/or nitrite use over time, seroconverters had the largest decreases. There was no evidence for abrupt or substantial increases in drug use or risky sex post-seroconversion. However, there was substantial variation at the individual level, with the factors underlying this variation not well understood and worth further study. Moreover, stimulant/nitrite use and risky sexual behavior appear to have been strongly influenced by contextual historical and socio-cultural effects. The manner in which contextual factors influence individual behavior is also not well understood and also warrants further study.


Assuntos
Nitrito de Amila/administração & dosagem , Estimulantes do Sistema Nervoso Central/administração & dosagem , Infecções por HIV/diagnóstico , Soropositividade para HIV , Homossexualidade Masculina/estatística & dados numéricos , Comportamento Sexual/psicologia , Parceiros Sexuais , Adulto , Nitrito de Amila/efeitos adversos , Estimulantes do Sistema Nervoso Central/efeitos adversos , Estudos de Coortes , Infecções por HIV/epidemiologia , Infecções por HIV/psicologia , Soronegatividade para HIV , HIV-1/imunologia , Homossexualidade Masculina/psicologia , Humanos , Estudos Longitudinais , Masculino , Comportamento de Redução do Risco , Assunção de Riscos , Soroconversão , Adulto Jovem
18.
AIDS Behav ; 22(11): 3658-3672, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29744767

RESUMO

Men who have sex with men (MSM) commonly use inhaled nitrites, or poppers, though their use is a risk factor HIV seroconversion. Pre-exposure prophylaxis, or PrEP, is effective for HIV prevention, but is not widely used, and little is known regarding PrEP use and acceptability among MSM who use inhaled nitrites. We surveyed 580 MSM in Paris, France in 2016 about popper use, sexual behaviors including condomless anal intercourse (CAI), serosorting, and sexual positioning, PrEP use, PrEP candidacy, and interest in alternate PrEP delivery modalities. We included 444 HIV negative participants for the current study. 46.2% reported popper use in the prior 3 months. Using multivariate adjusted logistic regression, we found that popper users were more likely than non-users to consider themselves candidates for PrEP [adjusted relative risk ratio (aRRR) = 2.73; 95% CI 1.54-4.83], but they were not more likely to be current (aRRR = 1.54; 95% CI 0.71-3.33) or past (aRRR = 1.37; 95% CI 0.44-4.28) PrEP users. Mediation analyses indicated that increased CAI and serosorting partly explained the relationship between popper use and PrEP candidacy. There was considerable interest in alternate proposed PrEP delivery modalities, particularly long-acting injectable PrEP [adjusted risk ratio (aRR) = 1.43; 95% CI 1.15-1.79].


Assuntos
Fármacos Anti-HIV/administração & dosagem , Infecções por HIV/prevenção & controle , Homossexualidade Masculina/psicologia , Nitritos/efeitos adversos , Profilaxia Pré-Exposição , Adulto , França , Seleção por Sorologia para HIV , Homossexualidade Masculina/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Nitritos/administração & dosagem , Razão de Chances , Profilaxia Pré-Exposição/métodos , Comportamento Sexual , Inquéritos e Questionários , Adulto Jovem
19.
Can J Physiol Pharmacol ; 96(9): 879-885, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29806986

RESUMO

Iron chelation can improve endothelial function. However, effect on endothelial function of deferiprone has not been reported. We hypothesized deferiprone could promote nitric oxide (NO) production in endothelial cells. We studied effects of deferiprone on blood nitrite and blood pressure after single oral dose (25 mg/kg) in healthy subjects and hemoglobin E/ß-thalassemia patients. Further, effects of deferiprone on NO production and endothelial NO synthase (eNOS) phosphorylation in primary human pulmonary artery endothelial cells (HPAEC) were investigated in vitro. Blood nitrite levels were higher in patients with deferiprone therapy than those without deferiprone (P = 0.023, n = 16 each). Deferiprone increased nitrite in plasma and whole blood of healthy subjects (P = 0.002 and 0.044) and thalassemia patients (P = 0.003 and 0.046) at time 180 min (n = 20 each). Asymptomatic reduction in diastolic blood pressure (P = 0.005) and increase in heart rate (P = 0.009) were observed in healthy subjects, but not in thalassemia patients. In HPAEC, deferiprone increased cellular nitrite and phospho-eNOS (Ser1177) (P = 0.012 and 0.035, n = 6) without alteration in total eNOS protein and mRNA. We conclude that deferiprone can induce NO production by enhancing eNOS phosphorylation in endothelial cells.


Assuntos
Óxido Nítrico Sintase Tipo III/metabolismo , Óxido Nítrico/biossíntese , Piridonas/farmacologia , Adulto , Pressão Sanguínea/efeitos dos fármacos , Deferiprona , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Feminino , Humanos , Masculino , Fosforilação/efeitos dos fármacos , Talassemia/metabolismo , Talassemia/patologia , Talassemia/fisiopatologia
20.
Ren Fail ; 40(1): 340-349, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29658815

RESUMO

Continuous intake of alcohol leads to liver cirrhosis because of imbalance of oxidative stress/antioxidative defense and chronic 'sterile inflammation'. Hepatorenal syndrome (HRS) is the most severe complication of liver cirrhosis. The aim of our study was to assess: (1) the oxidative stress/antioxidative defense markers such as malondialdehyde (MDA), oxidative glutathione (GSH) and glutathione S-transferase (GST), (2) inflammation [C-reactive protein (CRP)], and (3) nitrate/nitrite levels (NOx) and its substrate L-arginine level. The study enrolled three groups: a group with cirrhosis and HRS (48 patients), a group with cirrhosis without HRS (32 patients), and a control group (40 healthy blood donors). All the patients with cirrhosis and HRS had type II HRS. MDA concentration was significantly higher in the groups with cirrhosis with and without HRS. Significant positive correlation was documented between the MDA level and de Ritis coefficient (AST/ALT), a marker of liver damage severity; between MDA and inflammation (CRP); between MDA and NOx concentration in the groups with cirrhosis with and without HRS. The correlation between MDA and creatinine level was significant in the group with HRS. The levels of GSH and GST were significantly lower in the groups with cirrhosis with and without HRS. The results of the study revealed that an increase in MDA and NOx concentration, along with decreased values of antioxidative defense and L-arginine, may indicate that liver damage can have an influence on progression to renal failure.


Assuntos
Síndrome Hepatorrenal/patologia , Inflamação/patologia , Cirrose Hepática Alcoólica/patologia , Fígado/patologia , Adulto , Idoso , Arginina/sangue , Biomarcadores/sangue , Feminino , Glutationa/sangue , Glutationa Transferase/sangue , Síndrome Hepatorrenal/sangue , Síndrome Hepatorrenal/etiologia , Humanos , Inflamação/sangue , Inflamação/etiologia , Cirrose Hepática Alcoólica/sangue , Cirrose Hepática Alcoólica/complicações , Masculino , Pessoa de Meia-Idade , Nitratos/sangue , Nitritos/sangue , Estresse Oxidativo , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa