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1.
AIDS Care ; 34(7): 832-838, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-34082616

RESUMEN

Studies describing characteristics and outcomes of COVID-19 among people living with HIV are currently limited, lacking detailed evaluation of the interplay among demographics, HIV-related variables, and comorbidities on COVID-19 outcomes. This retrospective cohort study describes mortality rates overall and according to demographic characteristics and explores predictors of admission to intensive care unit and death among 255 persons living with HIV with severe acute respiratory syndrome and confirmed SARS-CoV-2 infection in the State of Sao Paulo, Brazil. We found that the overall mortality rate was 4.1/1,000 person-days, with a case-fatality of 34%. Higher rates occurred among older adults, Black/Mixed skin color/race patients, and those with lower schooling. In a multivariable analysis adjusted for age, sex, CD4 count, viral load and number of comorbidities, skin color/race, and schooling remained significantly associated with higher mortality. Although tenofovir use was more frequent among survivors in the univariable analysis, we failed to find a statistically significant association between tenofovir use and survival in the multivariable analysis. Our findings suggest that social vulnerabilities related to both HIV and COVID-19 significantly impact the risk of death, overtaking traditional risk factors such as age, sex, CD4 count, and comorbidities.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida , COVID-19 , Infecciones por VIH , Anciano , Brasil/epidemiología , Estudios de Cohortes , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Estudios Retrospectivos , SARS-CoV-2 , Tenofovir
2.
J Hazard Mater ; 412: 125236, 2021 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-33529834

RESUMEN

Arsenopyrite (FeAsS), the most common arsenic-bearing mineral, is usually found associated with pyrite (FeS2) in gold mining tailings. This work examined the galvanic effect of FeS2 on As release from FeAsS oxidation in circumneutral media under oxygen-depleted and oxygen-saturated conditions. The oxidation experiments were conducted with a flow-through reactor in the absence of FeS2 particles and in the presence of different contents of this sulfide. The results indicated that the permanent, physical contact between FeAsS and FeS2 particles causes an increase in the accumulated As release, mainly under O2-saturated conditions. At 30% wt. FeS2, the increases relatively to FeS2-free conditions were 82% and 117% in O2-depleted and O2-saturated solutions, respectively. At steady-state, the As release rates increased from (4.9 ± 0.5)× 10-4 µmol m-2 s-1 (0% wt. FeS2) to (1.1-1.9)× 10-3 µmol m-2 s-1 (5-30% wt. FeS2) under O2-saturated conditions. Analysis of FeAsS samples after oxidation revealed oxidized particles partially or entirely covered by precipitates with different sizes, shapes and compositions (e.g., As-S-bearing ferrihydrite, elemental sulfur, and As-O phases). A fine (3-4 nm thick) amorphous layer of S-As-bearing ferric oxy-hydroxide was also identified on oxidized FeAsS, with Fe(III) and As(III) species.

3.
Sci Rep ; 10(1): 18061, 2020 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-33093473

RESUMEN

Platelet-derived extracellular vesicles (PDEVs) are the most abundant amongst all types of EVs in the circulation. However, the mechanisms leading to PDEVs release, their role in coagulation and phenotypic composition are poorly understood. PDEVs from washed platelets were generated using different stimuli and were characterised using nanoparticle tracking analysis. Procoagulant properties were evaluated by fluorescence flow cytometry and calibrated automated thrombography. EVs from plasma were isolated and concentrated using a novel protocol involving a combination of size exclusion chromatography and differential centrifugation, which produces pure and concentrated EVs. Agonist stimulation enhanced PDEV release, but did not alter the average size of EVs compared to those produced by unstimulated platelets. Agonist stimulation led to lower negatively-charged phospholipid externalization in PDEVs, which was reflected in the lower procoagulant activity compared to those generated without agonist stimulation. Circulating EVs did not have externalized negatively-charged phospholipids. None of the 4 types of EVs presented tissue factor. The mechanism by which PDEV formation is induced is a critical determinant of its phenotype and function. Importantly, we have developed methods to obtain clean, concentrated and functional EVs derived from platelet-free plasma and washed platelets, which can be used to provide novel insight into their biological functions.


Asunto(s)
Coagulación Sanguínea , Plaquetas , Vesículas Extracelulares/fisiología , Adolescente , Adulto , Cromatografía en Gel , Vesículas Extracelulares/metabolismo , Femenino , Citometría de Flujo , Fluorescencia , Humanos , Masculino , Persona de Mediana Edad , Nanopartículas , Fenotipo , Fosfolípidos/metabolismo , Adulto Joven
4.
Auton Neurosci ; 228: 102716, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32882606

RESUMEN

Periaqueductal gray (PAG) is a midbrain region that projects to areas controlling behavioral and autonomic outputs and is involved in the behavioral and physiological components of defense reactions. Since Raphe Pallidus (RPa) is a medial medullary region comprising sympathetic premotor neurons governing heart function, it is worth considering the PAG-RPa path. We assessed: i) whether PAG projects to RPa; ii) the amplitude of cardiac responses evoked from PAG; iii) whether cardiovascular responses evoked from PAG rely on RPa. Experiments conducted in Wistar rats (±300 g) were approved by Ethics Committee CEUA-UFG (092/18). Firstly, (n = 3), monosynaptic retrograde tracer Retrobeads was injected into RPa; PAG slices were analyzed. Other two groups (n = 6 each) were anesthetized with urethane (1.4 g/kg) and chloralose (120 mg/kg) and underwent craniotomy, tracheostomy, catheterization of femoral artery and vein and of cardiac left ventricle. In one group, we injected the GABAA receptor antagonist, bicuculline methiodide (BMI - 40 pmol/100 nL) into lateral/dorsolateral PAG. Another group was injected (100 nL) with the GABAA receptor agonist muscimol (20 mM) into RPa, 20 min before BMI into PAG. The results were: i) retrogradely labelled neurons were found in PAG; ii) PAG activation by BMI caused positive chronotropism and inotropism, which were accompanied by afterload increases; iii) RPa inhibition with Muscimol reduced heart rate, arterial and ventricular pressures; iv) the subsequent PAG activation still increased arterial pressure, cardiac chronotropy and inotropy, but these responses were significantly attenuated. In conclusion, PAG activation increases cardiac chronotropy and inotropy, and these responses seem to rely on a direct pathway reaching ventromedial medullary RPa neurons.


Asunto(s)
Presión Sanguínea/fisiología , Corazón/fisiología , Núcleo Pálido del Rafe/fisiología , Sustancia Gris Periacueductal/fisiología , Sistema Nervioso Simpático/fisiología , Animales , Presión Sanguínea/efectos de los fármacos , Agonistas de Receptores de GABA-A/farmacología , Antagonistas de Receptores de GABA-A/farmacología , Corazón/efectos de los fármacos , Masculino , Vías Nerviosas/efectos de los fármacos , Vías Nerviosas/fisiología , Núcleo Pálido del Rafe/efectos de los fármacos , Sustancia Gris Periacueductal/efectos de los fármacos , Ratas Wistar , Sistema Nervioso Simpático/efectos de los fármacos
5.
Braz J Med Biol Res ; 53(9): e9375, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32696817

RESUMEN

In this paper, we complement our previous study on the antiproliferative activity of Calea fruticosa (Asteraceae) by isolating the compounds apigenin-4',7-dimethyl ether (1), budlein A (2), quercetin (3), and cichoriin (4) from the plant's aerial parts. The antiproliferative activity of these compounds was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method against human tumor cell lines. Compound 3 displayed moderate antiproliferative activity in three cell lines (HCT-116, PC-3, and SF-295, with cell growth inhibition values of 72.97, 74.55, and 68.94%) and high antiproliferative activity (90.86%) in the HL-60 cell line. The in vitro sun protection factor (SPF) of the extracts and compound 4, with and without sunscreen, was determined by a spectrophotometric method. The ethanol extract exhibited the highest SPF (9.67) at a concentration of 0.100 mg/mL, while compound 4, isolated from this extract, showed a SPF of 13.79 at the same concentration. A relative increased efficacy of SPF was observed for the extracts and compound 4 when sunscreen was also used. Compound 4 has not been reported previously from any species within the genus Calea. Compounds 1-4 were obtained from this species for the first time.


Asunto(s)
Asteraceae , Extractos Vegetales , Sustancias Protectoras , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos
6.
Braz. j. med. biol. res ; 53(9): e9375, 2020. tab, graf
Artículo en Inglés | LILACS, Coleciona SUS | ID: biblio-1132551

RESUMEN

In this paper, we complement our previous study on the antiproliferative activity of Calea fruticosa (Asteraceae) by isolating the compounds apigenin-4',7-dimethyl ether (1), budlein A (2), quercetin (3), and cichoriin (4) from the plant's aerial parts. The antiproliferative activity of these compounds was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method against human tumor cell lines. Compound 3 displayed moderate antiproliferative activity in three cell lines (HCT-116, PC-3, and SF-295, with cell growth inhibition values of 72.97, 74.55, and 68.94%) and high antiproliferative activity (90.86%) in the HL-60 cell line. The in vitro sun protection factor (SPF) of the extracts and compound 4, with and without sunscreen, was determined by a spectrophotometric method. The ethanol extract exhibited the highest SPF (9.67) at a concentration of 0.100 mg/mL, while compound 4, isolated from this extract, showed a SPF of 13.79 at the same concentration. A relative increased efficacy of SPF was observed for the extracts and compound 4 when sunscreen was also used. Compound 4 has not been reported previously from any species within the genus Calea. Compounds 1-4 were obtained from this species for the first time.


Asunto(s)
Humanos , Extractos Vegetales , Asteraceae , Sustancias Protectoras , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos
7.
Braz J Med Biol Res ; 52(11): e8441, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31721904

RESUMEN

The heptapeptide Bj-PRO-7a, isolated and identified from Bothrops jararaca (Bj) venom, produces antihypertensive and other cardiovascular effects that are independent on angiotensin converting enzyme inhibition, possibly relying on cholinergic muscarinic receptors subtype 1 (M1R). However, whether Bj-PRO-7a acts upon the central nervous system and modifies behavior is yet to be determined. Therefore, the aims of this study were: i) to assess the effects of acute administration of Bj-PRO-7a upon behavior; ii) to reveal mechanisms involved in the effects of Bj-PRO-7a upon locomotion/exploration, anxiety, and depression-like behaviors. For this purpose, adult male Wistar (WT, wild type) and spontaneous hypertensive rats (SHR) received intraperitoneal injections of vehicle (0.9% NaCl), diazepam (2 mg/kg), imipramine (15 mg/kg), Bj-PRO-7a (71, 213 or 426 nmol/kg), pirenzepine (852 nmol/kg), α-methyl-DL-tyrosine (200 mg/kg), or chlorpromazine (2 mg/kg), and underwent elevated plus maze, open field, and forced swimming tests. The heptapeptide promoted anxiolytic and antidepressant-like effects and increased locomotion/exploration. These effects of Bj-PRO-7a seem to be dependent on M1R activation and dopaminergic receptors and rely on catecholaminergic pathways.


Asunto(s)
Ansiedad , Conducta Animal/efectos de los fármacos , Venenos de Crotálidos/química , Depresión , Conducta Exploratoria/efectos de los fármacos , Oligopéptidos/farmacología , Prolina/farmacología , Animales , Conducta Animal/fisiología , Masculino , Oligopéptidos/aislamiento & purificación , Prolina/aislamiento & purificación , Ratas , Ratas Wistar
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 5836-5841, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31947179

RESUMEN

Laparoendoscopic single-site surgery (LESS) has been shown to reduce the invasiveness of surgery by requiring only one incision to access the abdominal cavity. However, single-site surgery integrating with a compact robotic surgical platform remains as a unique challenge. To address this challenge, we have designed a comprehensive robotic surgery platform that consists of three 6-DOF manipulators and a laparoscope camera can all be inserted into the operation field through a single 18 mm cannula holding by one 4 degrees of freedom light-weight supporting frame. Each dexterous manipulator is 5+1 degree-of-freedom (DOF), serially inserted and removable, and remotely driven by 12 actuation tendons and is composed of rigid links joined by hybrid flexure hinges. This paper introduces the compact multiple-tool single port laparoscopic robot platform for the first time. Details of the mechanical design of the trocar and manipulator including joint design and tendon routing are presented. The forward and inverse kinematics of the manipulator are also discussed along with an analysis and simulation of the cooperative workspace of two manipulators. A preliminary dynamic model of the manipulator was also constructed to study the effect of tendon-sheath friction forces at various joint configurations. Future work will illustrate the existing supporting frame mechanism for posing tools and trocar.


Asunto(s)
Laparoscopía/instrumentación , Procedimientos Quirúrgicos Robotizados/instrumentación , Diseño de Equipo
9.
Braz. j. med. biol. res ; 52(11): e8441, 2019. graf
Artículo en Inglés | LILACS | ID: biblio-1039261

RESUMEN

The heptapeptide Bj-PRO-7a, isolated and identified from Bothrops jararaca (Bj) venom, produces antihypertensive and other cardiovascular effects that are independent on angiotensin converting enzyme inhibition, possibly relying on cholinergic muscarinic receptors subtype 1 (M1R). However, whether Bj-PRO-7a acts upon the central nervous system and modifies behavior is yet to be determined. Therefore, the aims of this study were: i) to assess the effects of acute administration of Bj-PRO-7a upon behavior; ii) to reveal mechanisms involved in the effects of Bj-PRO-7a upon locomotion/exploration, anxiety, and depression-like behaviors. For this purpose, adult male Wistar (WT, wild type) and spontaneous hypertensive rats (SHR) received intraperitoneal injections of vehicle (0.9% NaCl), diazepam (2 mg/kg), imipramine (15 mg/kg), Bj-PRO-7a (71, 213 or 426 nmol/kg), pirenzepine (852 nmol/kg), α-methyl-DL-tyrosine (200 mg/kg), or chlorpromazine (2 mg/kg), and underwent elevated plus maze, open field, and forced swimming tests. The heptapeptide promoted anxiolytic and antidepressant-like effects and increased locomotion/exploration. These effects of Bj-PRO-7a seem to be dependent on M1R activation and dopaminergic receptors and rely on catecholaminergic pathways.


Asunto(s)
Animales , Masculino , Ratas , Oligopéptidos/farmacología , Ansiedad , Conducta Animal/efectos de los fármacos , Venenos de Crotálidos/química , Depresión , Conducta Exploratoria/efectos de los fármacos , Oligopéptidos/aislamiento & purificación , Conducta Animal/fisiología , Prolina/aislamiento & purificación , Prolina/farmacología , Ratas Wistar
10.
Braz. j. biol ; 76(2): 520-525, Apr.-June 2016. tab
Artículo en Inglés | LILACS | ID: lil-781411

RESUMEN

Abstract The objective of this study was to evaluate the action of Hymenaea stigonocarpa bark hydroalcoholic extract against a mutagenic compound using A. cepa meristematic root cells as a test system. The treatment groups were: Negative Control (NC) – distilled water; Positive Control (PC) – paracetamol at a concentration of 0.008 mg/mL, Jatoba Control (JC) – aqueous fraction jatobá-do-cerrado at 0.5 or 1.0 or 1.5 mg/mL, and Simultaneous Treatment (ST) - jatobá-do-cerrado aqueous fraction at a concentration of 0.5 or 1.0 or 1.5 mg/mL associated with paracetamol solution at a concentration of 0.008 mg/mL. All groups were analyzed at 24 and 48 h. Five onion bulbs (five replications) were used for each treatment group. The root tips were fixed in Carnoy and slides prepared by the crush technique. Cells were analyzed throughout the cell cycle, totaling 5,000 for each treatment group at each exposure time. Mitotic indices were subjected to statistical analysis using the chi-square test (p<0.05). From the results it was found that the ST group, at the three concentrations, significantly potentiated the antiproliferative effect of the test system cells when compared to PC, NC and TJ at the three concentrations. Furthermore, the three ST concentrations significantly reduced the number of cell aberrations when compared to the number of aberrant cells obtained for the PC, demonstrating antimutagenic action on the A. cepa test system cells.


Resumo O objetivo do presente trabalho foi avaliar a ação do extrato hidroalcólico do ritidoma de Hymenaea stigonocarpa frente a um composto mutagênico, utilizando como sistema teste as células meristemáticas de raízes de A. cepa. Os grupos tratamentos avaliados foram: Controle Negativo (CN) – água destilada; Controle Positivo (CP) – paracetamol na concentração de 0,008 mg/mL, Controle Jatobá (CJ) – fração aquosa de jatobá-do-cerrado na concentração de 0,5 ou 1,0 ou 1,5 mg/mL, e Tratamento Simultâneo (TS) – fração aquosa de jatobá-do-cerrado na concentração de 0,5 ou 1,0 ou 1,5 mg/mL associada a solução de paracetamol na concentração de 0,008 mg/mL. Todos os grupos foram analisados nos tempos de 24 e 48 h. Para cada grupo tratamento cinco bulbos de cebolas (cinco repetições) foram utilizados. As radículas foram fixadas em Carnoy e as lâminas preparadas pela técnica de esmagamento. Analisaram-se células em todo ciclo celular, totalizando 5.000 para cada grupo tratamento em cada tempo de exposição. Os índices mitóticos obtidos foram submetidos à análise estatística do Qui-quadrado (p<0,05). A partir dos resultados verificou-se que o grupo TS, nas três concentrações, potencializou o efeito antiproliferativo significativo as células do sistema teste quando comparado ao CP, CN e TJ nas três concentrações. Ainda, o TS nas três concentrações reduziu de forma significativa o número de aberrações celulares quando comparado com o número de células aberrantes obtidas para o CP, demonstrando ação antimutagênica as células do sistema teste A. cepa.


Asunto(s)
Extractos Vegetales/farmacología , Cebollas/citología , Cebollas/fisiología , Hymenaea , Acetaminofén/farmacología , Factores de Tiempo , Ciclo Celular/efectos de los fármacos , Meristema , Corteza de la Planta , Antimitóticos/farmacología , Antipiréticos/farmacología , Índice Mitótico/métodos , Mutágenos/metabolismo , Mutágenos/farmacología
11.
Braz. j. biol ; 76(2): 439-443, Apr.-June 2016. tab
Artículo en Inglés | LILACS | ID: lil-781381

RESUMEN

Abstract Despite their great importance for the food industry, flavorings, in general, raise a number of questions regarding their cytotoxicity, mutagenicity and carcinogenicity, since, in the literature, there are few studies found evaluating the toxicity on the systemic and cellular level, of these chemical compounds. The root meristems of Allium cepa (onion) are widely used for the assessment of toxicity of chemical compounds of interest. Thus, this study aimed to evaluate, in A. cepa meristematic cells, individually and in combination at the cellular level, the toxicity of synthetic Cheese and Cheddar Cheese food flavorings, identical to the natural, at doses of 1.0 and 2.0 mL, at exposure times of 24 and 48 hours. In combination we used 0.5 mL of Cheese flavor associated with 0.5 mL of Cheddar flavor; and 1.0 mL of Cheese flavor associated with 1.0 mL of Cheddar flavor, at exposure times of 24 and 48 hours. For these evaluations, we used groups of five onion bulbs, which were first embedded in distilled water and then transferred to their respective doses. The root tips were collected and fixed in acetic acid (3:1) for 24 hours. The slides were prepared by crushing and were stained with 2% acetic orcein. Cells were analyzed throughout the cell cycle, totaling 5,000 for each control and exposure time. The mitotic indices calculated and cellular aberrations observed were subjected to statistical analysis using the chi-square test (p <0.05). No chromosomal abnormalities nor those of mitotic spindle were observed for the treatments performed. The results, both individually and in combination, showed that the flavorings under study significantly reduced the cell division rate of the test system cells used. Therefore, under the conditions studied, the two flavorings were cytotoxic.


Resumo Apesar da grande importância para a indústria alimentícia, os aromatizantes, em geral, suscitam uma série de dúvidas quanto a sua citotoxicidade, mutagenicidade e carcinogenicidade, visto que, na literatura, poucos são os trabalhos encontrados avaliando a toxicidade, em nível sistêmico e celular, destes compostos químicos. Os meristemas de raízes de Allium cepa (cebola) são muito utilizados para a avaliação da toxicidade de compostos químicos de interesse. Desta forma, este trabalho teve por objetivo avaliar em células meristemáticas de A. cepa, de forma individual, a toxicidade em nível celular de aromatizantes alimentares sintéticos, idênticos aos naturais, de sabores Queijo e Queijo Cheddar, nas doses de 1,0 e 2,0 mL, nos tempos de exposição de 24 e 48 horas; e de forma associada, onde se utilizou 0,5 mL do aromatizante sabor Queijo associado a 0,5 mL do aromatizante sabor Queijo Cheddar; e 1,0 mL do aromatizante sabor Queijo associado a 1,0 mL do aromatizante sabor Queijo Cheddar, nos tempos de exposição de 24 e 48 horas. Para estas avaliações utilizou-se grupos de cinco bulbos de cebolas, que primeiramente foram enraizados em água destilada, e em seguida transferidos para as suas respectivas doses. As radículas foram coletadas e fixadas em ácido acético (3:1) por 24 horas. As lâminas foram preparadas pela técnica de esmagamento e coradas com orceína acética a 2%. Analisaram-se células em todo ciclo celular, totalizando 5.000 para cada controle e tempo de exposição. Os índices mitóticos calculados e as aberrações celulares observadas foram submetidos à análise estatística do Qui-quadrado (p<0,05). Não foram observadas alterações cromossômicas e anomalias de fuso mitótico para nenhum dos tratamentos realizados. Os resultados obtidos, tanto individualmente como de forma associada, mostraram que os aromatizantes em estudos reduziram de forma significativa os índices de divisões celulares das células do sistema teste utilizado. Portanto, nas condições analisadas, os dois aromatizantes foram citotóxicos.


Asunto(s)
Queso , Meristema/efectos de los fármacos , Cebollas/efectos de los fármacos , Aromatizantes/toxicidad , División Celular/efectos de los fármacos , Cebollas/citología , Índice Mitótico
12.
Braz J Biol ; 76(2): 520-5, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27058600

RESUMEN

The objective of this study was to evaluate the action of Hymenaea stigonocarpa bark hydroalcoholic extract against a mutagenic compound using A. cepa meristematic root cells as a test system. The treatment groups were: Negative Control (NC) - distilled water; Positive Control (PC) - paracetamol at a concentration of 0.008 mg/mL, Jatoba Control (JC) - aqueous fraction jatobá-do-cerrado at 0.5 or 1.0 or 1.5 mg/mL, and Simultaneous Treatment (ST) - jatobá-do-cerrado aqueous fraction at a concentration of 0.5 or 1.0 or 1.5 mg/mL associated with paracetamol solution at a concentration of 0.008 mg/mL. All groups were analyzed at 24 and 48 h. Five onion bulbs (five replications) were used for each treatment group. The root tips were fixed in Carnoy and slides prepared by the crush technique. Cells were analyzed throughout the cell cycle, totaling 5,000 for each treatment group at each exposure time. Mitotic indices were subjected to statistical analysis using the chi-square test (p<0.05). From the results it was found that the ST group, at the three concentrations, significantly potentiated the antiproliferative effect of the test system cells when compared to PC, NC and TJ at the three concentrations. Furthermore, the three ST concentrations significantly reduced the number of cell aberrations when compared to the number of aberrant cells obtained for the PC, demonstrating antimutagenic action on the A. cepa test system cells.


Asunto(s)
Acetaminofén/farmacología , Hymenaea , Cebollas , Extractos Vegetales/farmacología , Antimitóticos/farmacología , Antipiréticos/farmacología , Ciclo Celular/efectos de los fármacos , Meristema , Índice Mitótico/métodos , Mutágenos/metabolismo , Mutágenos/farmacología , Cebollas/citología , Cebollas/fisiología , Corteza de la Planta , Factores de Tiempo
13.
Braz J Biol ; 76(2): 439-43, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26959949

RESUMEN

Despite their great importance for the food industry, flavorings, in general, raise a number of questions regarding their cytotoxicity, mutagenicity and carcinogenicity, since, in the literature, there are few studies found evaluating the toxicity on the systemic and cellular level, of these chemical compounds. The root meristems of Allium cepa (onion) are widely used for the assessment of toxicity of chemical compounds of interest. Thus, this study aimed to evaluate, in A. cepa meristematic cells, individually and in combination at the cellular level, the toxicity of synthetic Cheese and Cheddar Cheese food flavorings, identical to the natural, at doses of 1.0 and 2.0 mL, at exposure times of 24 and 48 hours. In combination we used 0.5 mL of Cheese flavor associated with 0.5 mL of Cheddar flavor; and 1.0 mL of Cheese flavor associated with 1.0 mL of Cheddar flavor, at exposure times of 24 and 48 hours. For these evaluations, we used groups of five onion bulbs, which were first embedded in distilled water and then transferred to their respective doses. The root tips were collected and fixed in acetic acid (3:1) for 24 hours. The slides were prepared by crushing and were stained with 2% acetic orcein. Cells were analyzed throughout the cell cycle, totaling 5,000 for each control and exposure time. The mitotic indices calculated and cellular aberrations observed were subjected to statistical analysis using the chi-square test (p <0.05). No chromosomal abnormalities nor those of mitotic spindle were observed for the treatments performed. The results, both individually and in combination, showed that the flavorings under study significantly reduced the cell division rate of the test system cells used. Therefore, under the conditions studied, the two flavorings were cytotoxic.


Asunto(s)
Queso , Aromatizantes/toxicidad , Meristema/efectos de los fármacos , Cebollas/efectos de los fármacos , División Celular/efectos de los fármacos , Índice Mitótico , Cebollas/citología
14.
Phys Chem Chem Phys ; 17(48): 32126-31, 2015 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-26088917

RESUMEN

The temperature dependence (10-290 K) of the low-frequency (20-150 cm(-1)) Raman-active phonon modes of deeply supercooled confined water in L,L-diphenylalanine micro/nanotubes was analyzed. The isolated dynamics of a specific geometry of a water cluster (pentamer) in a supercooled confined regime was studied in detail. A fragile-to-strong transition at 204 K was observed and related to the crossing of the Widom line. Analysis of peptide vibrational modes coupled to water hydrogen bonds indicated that hydrogen bond fluctuations play an irrelevant role in this system. Our results are in agreement with the second critical point of water existence hypothesis.


Asunto(s)
Nanotubos , Fenilalanina/análogos & derivados , Agua/química , Dipéptidos , Fenilalanina/química , Espectrometría Raman , Temperatura
15.
Nano Lett ; 15(5): 3159-65, 2015 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-25831487

RESUMEN

Existing theory and data cannot quantify the contribution of phonon drag to the Seebeck coefficient (S) in semiconductors at room temperature. We show that this is possible through comparative measurements between nanowires and the bulk. Phonon boundary scattering completely quenches phonon drag in silicon nanowires enabling quantification of its contribution to S in bulk silicon in the range 25-500 K. The contribution is surprisingly large (∼34%) at 300 K even at doping of ∼3 × 10(19) cm(-3). Our results contradict the notion that phonon drag is negligible in degenerate semiconductors at temperatures relevant for thermoelectric energy conversion. A revised theory of electron-phonon momentum exchange that accounts for a phonon mean free path spectrum agrees well with the data.

16.
J Mater Chem B ; 3(30): 6355-6367, 2015 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-32262754

RESUMEN

Supramolecular hydrogels rely on small molecules that self-assemble in water as a result of the cooperative effect of several relatively weak intermolecular interactions. Peptide-based low molecular weight hydrogelators have attracted enormous interest owing to the simplicity of small molecules combined with the versatility and biocompatibility of peptides. In this work, naproxen, a well known non-steroidal anti-inflammatory drug, was N-conjugated with various dehydrodipeptides to give aromatic peptide amphiphiles that resist proteolysis. Molecular dynamics simulations were used to obtain insight into the underlying molecular mechanism of self-assembly and to rationalize the design of this type of hydrogelators. The results obtained were in excellent agreement with the experimental observations. Only dehydrodipeptides having at least one aromatic amino acid gave hydrogels. The characterization of the hydrogels was carried out using transmission electron microscopy (TEM), circular dichroism (CD), fluorescence spectroscopy and also rheological assays.

17.
Rev. bras. plantas med ; 17(4): 550-561, out.-dez. 2015. tab, graf
Artículo en Portugués | LILACS | ID: lil-763227

RESUMEN

RESUMOEste trabalho realizou um levantamento sobre o uso de plantas medicinais na cidade de Picos-PI, identificou as plantas cultivadas no horto pertencente ao Laboratório Fitoterápico de Picos (LAFIPI), e analisou o uso de fitoterápicos dispensados pelo Programa Farmácia Viva no triênio 2008-2010. Do total dos 750 entrevistados, 37,6% foram homens e 62,4 % mulheres, dentre os quais a maioria não concluiu o segundo grau (69,2%) e 77,2% possuíam renda mensal de até dois salários mínimos. Com relação ao consumo de plantas medicinais, 76,3% afirmaram utilizá-las para tratar doenças, principalmente por considerá-las mais saudáveis (84,8%). A indicação do uso foi orientada, sobretudo, por familiares (82,2%), embora a maioria adquira as plantas em feiras livres (32,8%). Das 127 plantas relatadas, as mais citadas foram erva-cidreira, boldo e hortelã, sendo as folhas a parte mais utilizada (42,3%), predominantemente por infusão (39,4%). As aplicações mais lembradas foram para tratar dores em geral (17%), distúrbios respiratórios (16,5%) e digestivos (16%). As espécies mais cultivadas no horto são chambá (Justicia pectoralis), alecrim pimenta (Lippia sidoides), malva santa (Plectranthus barbatus) e erva cidreira (Lippia alba). O lambedor de chambá foi o fitoterápico mais procurado pela população entre 2008 e 2010. Esse estudo descreveu, pela primeira vez, o uso tradicional de plantas medicinais no município de Picos e demonstrou, também de forma inédita, a relevância de investimentos do Programa Farmácia Viva no município de Picos e sua inclusão no Programa Saúde da Família como forma de disponibilizar à população de baixa renda fitoterápicos produzidos localmente a custos reduzidos.


ABSTRACTThis study performed a research about the use of medicinal plants in Picos city, identifying the plants grown in the garden belonging to the Laboratory of Phytotherapics in Picos (LAFIPI) and analying the use of phytotherapics distributed by the Farmácia Viva Project between 2008-2010. From the total of 750 interviewed participants, 37.6% were men and 62.4 % women. Most of them do not have secondary education (69.2%) and 77.2% had an income of up until two minimum wages. Regarding consumption of medicinal plants, 76.3 % used them to treat diseases, mainly because they considered them to be healthier (84.8%). The indication of use of the plants was mainly suggested by relatives (82.2%), even though the majority of the participants acquires plants in open markets (32.8%). From the 127 plants mentioned, the most cited ones were balm, boldo and mint, and leaves were the most utilized parts (42.3%), predominantly by infusion (39.4%). The most common reasons for the usewere to treat pain in general (17%), and respiratory (16.5%) and digestive disorders (16%). The most cultivated species in the garden were chambá (Justicia pectoralis), alecrim pimenta (Lippia sidoides), malva santa (Plectranthus barbatus) and erva cidreira (Lippia alba). The "chambá licker" was the most herbal medicine searched by the population between 2008 and 2010. This investigation described, for the first time, the traditional use of medicinal plants in Picos and demonstrated,alsounprecedentedly, the relevance of investments in the Farmácia Viva Project in Picos city and its inclusion in the Family Health Program as a strategyin order to provide locally producedphytotherapics for low-income population at low costs.


Asunto(s)
Farmacia/instrumentación , Plantas Medicinales/clasificación , Fitoterapia , Etnobotánica/instrumentación , Toxicidad/efectos adversos
18.
Br J Nutr ; 112(12): 1923-32, 2014 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-25347215

RESUMEN

Epigenetic studies suggest that diseases that develop in adulthood are related to certain conditions to which the individual is exposed during the initial stages of life. Experimental evidence has demonstrated that offspring born to mothers maintained on high-Na diets during pregnancy have higher mean arterial pressure (MAP) in adulthood. Although these studies have demonstrated the importance of prenatal phases to hypertension development, no evidence regarding the role of high Na intake during postnatal phases in the development of this pathology has been reported. Therefore, in the present study, the effects of Na overload during childhood on induced water and Na intakes and on cardiovascular parameters in adulthood were evaluated. Experiments were carried out in two groups of 21-d-old rats: experimental group, maintained on hypertonic saline (0.3 m-NaCl) solution and food for 60 d, and control group, maintained on tap water and food. Later, both groups were given water and food for 15 d (recovery period). After the recovery period, chronic cannulation of the right femoral artery was performed in unanaesthetised rats to record baseline MAP and heart rate (HR). The experimental group was found to have increased basal MAP (98.6 (sem 2.6) v. 118.3 (sem 2.7) mmHg, P< 0.05) and HR (365.4 (sem 12.2) v. 398.2 (sem 7.5) beats per min, P< 0.05). There was a decrease in the baroreflex index in the experimental group when compared with that in the control group. A water and Na intake test was performed using furosemide. Na depletion was found to induce an increase in Na intake in both the control and experimental groups (12.1 (sem 0.6) ml and 7.8 (sem 1.1), respectively, P< 0.05); however, this increase was of lower magnitude in the experimental group. These results demonstrate that postnatal Na overload alters behavioural and cardiovascular regulation in adulthood.


Asunto(s)
Presión Arterial , Dieta , Hipertensión/etiología , Fenómenos Fisiológicos Nutricionales del Lactante , Cloruro de Sodio Dietético , Sodio , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Animales Recién Nacidos , Barorreflejo , Ingestión de Energía , Femenino , Furosemida , Frecuencia Cardíaca , Humanos , Recién Nacido , Masculino , Ratas Wistar , Sodio/administración & dosificación , Sodio/farmacología , Cloruro de Sodio Dietético/administración & dosificación , Cloruro de Sodio Dietético/farmacología
19.
Artículo en Portugués | LILACS | ID: lil-737687

RESUMEN

In the West, the consumption of medicinal plants is increasing strongly, and up to 40% of the population use medicinal plants and phytotherapic preparations regularly, in the belief that they are innocuous and/or safe. However, in most cases there is no scientific proof of their pharmacological and toxicological properties. The aim of this study was to carry out a bibliographical review of the toxicological properties of Casearia sylvestris Swartz and collect data providing a basis for its rational use. Some studies validate classical therapeutic indications of C. sylvestris, such as to treat diarrhea and snakebites, justifying its empirical use. Nevertheless, there are few reports about its toxicological properties and these present only limited findings, describing results as 50% lethal dose (LD50) and the acute toxicity of its constituents. Currently, research is insufficient to ensure safety of popular preparations based on C. sylvestris. Therefore, it is necessary to make a fuller assessment of its deleterious profile, especially with respect to the toxic potential of its constituents, as well as its capacity to harm target organs and organic systems...


No Ocidente, o consumo de plantas medicinais vem aumentando substancialmente, onde cerca de 40% da população utiliza regularmente plantas medicinais e preparações fitoterápicas sob o rótulo de serem produtos inócuos ou seguros. Porém, na maioria das vezes, não há comprovação científica de suas propriedades farmacológicas e toxicológicas. O objetivo deste trabalho foi realizar um levantamento bibliográfico sobre as propriedades toxicológicas da Casearia sylvestris Swartz e coletar dados que fundamentem seu uso racional. Alguns estudos validam indicações terapêuticas clássicas da C. sylvestris como antidiarréico e no tratamento de ferimentos ofídicos, fundamentando seu uso empírico. Porém, poucos trabalhos relatam suas propriedades toxicológicas, havendo apenas abordagens limitadas em torno da Dose Letal 50% e da toxicidade aguda de seus constituintes. Até o presente momento, as pesquisas são insuficientes para garantir a segurança de preparações populares à base de C. sylvestris. Portanto, há necessidade de avaliar melhor seu perfil deletério, principalmente, no que diz respeito ao potencial tóxico de seus constituintes, assim como a sua capacidade lesiva sobre órgãos-alvos e sistemas orgânicos...


Asunto(s)
Humanos , Casearia/efectos adversos , Casearia/toxicidad , Diterpenos de Tipo Clerodano , Plantas Medicinales
20.
Dalton Trans ; 43(8): 3162-73, 2014 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-24343660

RESUMEN

We have proposed recently that the DO3A-N-α-(amino)propionate chelator and its amide conjugates are leads to targeted, high relaxivity, safe contrast agents for magnetic resonance imaging. In this work we illustrate further the expeditious nature and robustness of the synthetic methodologies developed by preparing the DO3A-N-(α-pyrenebutanamido)propionate chelator. Its Gd(3+) chelate retains the optimized water exchange, high stability and inertness of the parent complex. The pyrene moiety imparts concentration-dependent self-assembly properties and aggregation-sensitive fluorescence emission to the Gd(3+) complex. The Gd(3+) complex displays pyrene-centred fluorescence whilst the Yb(3+) and Nd(3+) complexes exhibit sensitized lanthanide-centred near-infrared luminescence. The aggregated form of the complex displays high relaxivity (32 mM(-1) s(-1), 20 MHz, 25 °C) thanks to simultaneous optimization of the rotational correlation time and of the water exchange rate. The relaxivity is however still limited by chelate flexibility. This report demonstrates that the DO3A-N-(α-amino)propionate chelator is a valuable platform for constructing high relaxivity CA using simple design principles and robust chemistries accessible to most chemistry labs.


Asunto(s)
Complejos de Coordinación/química , Elementos de la Serie de los Lantanoides/química , Animales , Quelantes/síntesis química , Quelantes/química , Medios de Contraste/síntesis química , Medios de Contraste/química , Medios de Contraste/metabolismo , Complejos de Coordinación/síntesis química , Complejos de Coordinación/metabolismo , Gadolinio/química , Humanos , Cinética , Unión Proteica , Pirenos/química , Ratas , Ratas Wistar , Albúmina Sérica/química , Albúmina Sérica/metabolismo , Espectroscopía Infrarroja Corta , Temperatura , Distribución Tisular , Agua/química
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