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1.
Braz J Med Biol Res ; 56: e12777, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37493773

RESUMO

To evaluate the risks of hair dye exposure, we investigated cellular and molecular effects of Arianor Ebony dye, which is a mixture of azo and anthraquinone dyes, used in the composition of the black color. Cytotoxicity, genotoxicity, and gene expression of relevant molecules of apoptotic and oxidative stress mechanisms were investigated in HepG2 cells exposed to Arianor Ebony. Results showed that the dye did not induce cytotoxicity to exposed cells at a concentration up to 50 µg/mL compared to the negative control. However, genotoxic assays indicated that the dye was able to damage the genetic material at a concentration of 25 µg/mL, with induction factor values of exposed cells two- to five-fold higher than those recorded for the negative control. Moreover, the lowest observed effect concentration was 12.5 µg/mL. For gene expression, relevant changes were observed in cytochrome c and caspase 9, which decreased in cells incubated with the dye in a dose-dependent manner when compared with the negative control. In parallel, the expression of genes for antioxidant enzymes was increased in exposed cells, suggesting the presence of metabolic routes that protect cells against the toxic effect of the dye, avoiding exacerbated cellular death. Results suggested that the dye disrupted cellular homeostasis through mitochondrial dysfunction, which may be hazardous to human health. Thus, further investigations are necessary to deeply understand the mechanisms of action of the dye, considering its toxic potential found in our ex vivo assays.


Assuntos
Tinturas para Cabelo , Humanos , Tinturas para Cabelo/toxicidade , Células Hep G2
2.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;56: e12777, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1447683

RESUMO

To evaluate the risks of hair dye exposure, we investigated cellular and molecular effects of Arianor Ebony dye, which is a mixture of azo and anthraquinone dyes, used in the composition of the black color. Cytotoxicity, genotoxicity, and gene expression of relevant molecules of apoptotic and oxidative stress mechanisms were investigated in HepG2 cells exposed to Arianor Ebony. Results showed that the dye did not induce cytotoxicity to exposed cells at a concentration up to 50 µg/mL compared to the negative control. However, genotoxic assays indicated that the dye was able to damage the genetic material at a concentration of 25 µg/mL, with induction factor values of exposed cells two- to five-fold higher than those recorded for the negative control. Moreover, the lowest observed effect concentration was 12.5 µg/mL. For gene expression, relevant changes were observed in cytochrome c and caspase 9, which decreased in cells incubated with the dye in a dose-dependent manner when compared with the negative control. In parallel, the expression of genes for antioxidant enzymes was increased in exposed cells, suggesting the presence of metabolic routes that protect cells against the toxic effect of the dye, avoiding exacerbated cellular death. Results suggested that the dye disrupted cellular homeostasis through mitochondrial dysfunction, which may be hazardous to human health. Thus, further investigations are necessary to deeply understand the mechanisms of action of the dye, considering its toxic potential found in our ex vivo assays.

3.
J Nanosci Nanotechnol ; 21(11): 5694-5697, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-33980382

RESUMO

Magnetic nanocomposites based on maghemite nanoparticles supported (ex situ route) on styrene- divinilbenzene (Sty-DVB) copolymer templates were produced and characterized for their structure and morphology. The as-produced nanocomposites were further chemically-treated with different oxidant agents and surface-coated with stearic acid. X-ray diffraction and transmission electron microscopy data show that the incorporated nanoparticles are preserved despite the aggressive chemical treatments employed. From the dynamical susceptibility measurements performed on the nanocomposites, the values of the saturation magnetization (76 emu/g) and the effective magnetic anisotropy (1.7 × 104 J/m³) were obtained, in excellent agreement with the values reported in the literature for maghemite. This finding strongly supports the preservation of the magnetic properties of the supported nanosized maghemite throughout the entire samples' processing.

4.
Nanotechnology ; 29(36): 365701, 2018 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-29894981

RESUMO

Magnetic nanoparticles (NPs) have attracted great attention owing to their applications in the biomedical field. In the present work, maghemite (γFe2O3) NPs of 6.5 nm were prepared using a sonochemical method and used to prepare magnetic beads through silanization with 3-aminopropyltrimethoxysilane (APTS). Subsequently, amino groups in the resulting APTS-γFe2O3 beads were converted to carboxylic acid (CARB-γFe2O3) through the succinic anhydride reaction, as confirmed by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy and dynamic light scattering (DLS) measurements. The size of these beads was measured as 12 nm and their hydrodynamic diameter as 490 nm, using TEM analysis and DLS, respectively. The CARB-γFe2O3 beads were further functionalized by immobilizing rabbit antibodies on their surfaces; the immobilization was confirmed by flow cytometry and ionic strength. The samples were further characterized by Mössbauer spectroscopy and DC magnetization measurements. Studies on magnetic relaxivities showed that magnetic beads present great potential for application in MR imaging.


Assuntos
Anticorpos/metabolismo , Compostos Férricos/síntese química , Microesferas , Animais , Ácidos Carboxílicos/química , Difusão Dinâmica da Luz , Compostos Férricos/química , Fluorescência , Imageamento por Ressonância Magnética , Magnetismo , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Propilaminas/química , Coelhos , Silanos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Espectroscopia de Mossbauer , Eletricidade Estática , Vibração , Difração de Raios X
5.
Genet Mol Res ; 15(1)2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26909961

RESUMO

Jatropha gossypiifolia L. (Euphorbiaceae) is widely used in popular medicine. However, further toxicological studies are necessary for its reliable use. The present study aimed to evaluate the cytotoxic, genotoxic, and mutagenic effects of ethanolic and aqueous leaf extracts of J. gossypiifolia, using the test system Allium cepa. In addition, the phytochemical profile of the extracts was also obtained. Seeds of A. cepa were subjected to different concentrations of the two extracts (0.001, 0.01, 0.1, 1, and 10 mg/mL). Distilled water was used for the negative control and methyl methanesulfonate (4 x 10(-4) M) and trifluralin (0.84 ppm) for the positive controls. The values of mitotic index at all concentrations of ethanolic extract and at 0.1, 1, and 10 mg/mL aqueous extract showed a significant decrease. Alterations, such as chromosome adherence, C-metaphases, chromosome bridges, nuclear buds, and micronuclei were verified in both extracts but chromosome loss indicating genotoxic activity was observed only in the ethanolic extract. Presence of micronuclei on administration of the extracts, also indicated mutagenic action at the chromosome level. In the ethanolic extract, aneugenicity seemed to be the main activity, probably as a result of the action of terpenes and/or flavonoids, whereas in the aqueous extract, clastogenic action appeared to be the principal activity, presumably as a consequence of the effect of flavonoids and/or saponins. Thus, we suggest that the extracts of this species should be used with great caution for medicinal purpose.


Assuntos
Aberrações Cromossômicas/induzido quimicamente , Jatropha/efeitos adversos , Cebolas/efeitos dos fármacos , Extratos Vegetais/efeitos adversos , Folhas de Planta/química , Flavonoides , Jatropha/química , Jatropha/toxicidade , Índice Mitótico , Cebolas/genética , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Saponinas , Sementes/efeitos dos fármacos , Sementes/genética
6.
Genet Mol Res ; 13(3): 4808-19, 2014 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-24615117

RESUMO

This study evaluated the mutagenicity and antimutagenicity of inulin in a chromosomal aberration assay in cultures of the meristematic cells of Allium cepa. The treatments evaluated were as follows: negative control--seed germination in distilled water; positive control--aqueous solution of methyl methanesulfonate (10 µg/mL MMS); mutagenicity--aqueous solutions of inulin (0.015, 0.15, and 1.50 µg/mL); and antimutagenicity--associations between MMS and the different inulin concentrations. The antimutagenicity protocols established were pre-treatment, simultaneous simple, simultaneous with pre-incubation, and post-treatment. The damage reduction percentage (DR%) was 43.56, 27.77, and 55.92% for the pre-treatment; -31.11, 18.51, and 7.03% for the simultaneous simple; 30.43, 19.12, and 21.11% for the simultaneous with pre-incubation; and 64.07, 42.96, and 53.70% for the post-treatment. The results indicated that the most effective treatment for inhibiting damages caused by MMS was the post-treatment, which was followed by the pre-treatment, suggesting activity by bioantimutagenesis and desmutagenesis. The Allium cepa assay was demonstrated to be a good screening test for this type of activity because it is easy to perform, has a low cost, and shows DR% that is comparable to that reported studies that evaluated the prevention of DNA damage in mammals by inulin.


Assuntos
Antimutagênicos/farmacologia , Aberrações Cromossômicas/efeitos dos fármacos , Inulina/farmacologia , Metanossulfonato de Metila/farmacologia , Mutagênicos/farmacologia , Cebolas/efeitos dos fármacos , Células Cultivadas , Dano ao DNA , Meristema/citologia , Meristema/efeitos dos fármacos , Meristema/metabolismo , Metanossulfonato de Metila/antagonistas & inibidores , Índice Mitótico , Cebolas/citologia , Cebolas/metabolismo
7.
Brain Res Bull ; 97: 32-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23727546

RESUMO

Ganglionic synapses have the capability to express long-term potentiation (gLTP) after application of a brief high-frequency stimulus. It has been suggested a possible role of gLTP in some cardiovascular diseases. Although a number of characteristics of gLTP have been described, the precise locations and mechanisms underlying gLTP are not completely known. Current findings support two major conflicting presynaptic and postsynaptic hypotheses. The presynaptic hypothesis posits a presynaptic increase in acetylcholine (ACh) release, whereas the postsynaptic hypothesis proposes a long-lasting enhancement of the nicotinic response on the postsynaptic membrane. An alternative trans-synaptic hypothesis proposes the presynaptic release of a cotransmitter from large dense core vesicles, which postsynaptically enhances synaptic efficacy and accounts for gLTP. Here, we review the studies of LTP, with emphasis on gLTP in mammals, and we examine the findings that support the presynaptic, the postsynaptic and the trans-synaptic hypotheses. We then review our data on the contribution of calcium to gLTP as an approach to elucidate the mechanisms of gLTP. Data on the contribution of calcium to gLTP and on prolonged high-frequency stimulus-dependent fading of LTP have led us to support the trans-synaptic process as responsible for gLTP. Finally, we present a formal working model for the mechanisms of gLTP.


Assuntos
Cálcio/fisiologia , Gânglios Autônomos/fisiologia , Potenciação de Longa Duração , Sinapses/fisiologia , Animais , Gânglios Autônomos/ultraestrutura , Ratos
8.
Artigo em Inglês | MEDLINE | ID: mdl-22867562

RESUMO

Photoacoustic spectroscopy (PAS) has revolutionized the fields of biological, environmental, and agricultural sciences. It is a very simple, sensitive, and non-destructive technique that allows the determination of optical properties of bio-samples. The in vivo chlorophylls of the leaf have a recorded maximum absorption peak at 675 nm as against 665 nm of the in vitro chlorophylls. The intensity of purple pigmentation in leaves of Blepharocalyx salicifolius (Kunt) O. Berg, is inversely correlated to the soil moisture levels, leaf water content and leaf water potentials. The applicability of PAS to biological samples was discussed. It allows the validation of existing emission models which are important for atmospheric process. A portable device for photoacoustic spectroscopy of plants and other photosynthetic tissues, cells and organelles is provided. Further, there is provided a method to measure photosynthesis of such tissues, cells and organelles.


Assuntos
Myrtaceae/química , Técnicas Fotoacústicas/métodos , Absorção , Folhas de Planta/química , Espectrofotometria Infravermelho , Temperatura
9.
Artigo em Inglês | MEDLINE | ID: mdl-22483383

RESUMO

Photoacoustic spectroscopy was used to investigate magnetic nanocomposites incorporating nanosized maghemite particles into styrene-divinylbenzene copolymer template. Typical photoacoustic features were observed in bands C, S and L in the wavelength region of 300-1000 nm. The relative intensity of band-C scaled with the nominal concentration of nanosized maghemite incorporated into the polymeric template whereas the lowest relative intensity of band-S was found in the sample in which the template polymerization took place in the presence of the highest polar-like reaction medium. X-ray diffraction and transmission electron microscopy were used to characterize the magnetic nanosized phase as maghemite, with average particle diameter of 6.9 nm (sample Est34), 7.0 nm (sample H30), and 7.9 nm (sample Em15).


Assuntos
Compostos Férricos/química , Nanocompostos/química , Técnicas Fotoacústicas/métodos , Nanocompostos/ultraestrutura , Tamanho da Partícula , Análise Espectral , Temperatura , Difração de Raios X
10.
Artigo em Inglês | MEDLINE | ID: mdl-22436999

RESUMO

The chemical stability of magnetic particles is of great importance for their applications in medicine and biotechnology. The most challenging problem in physics of disordered systems of magnetic nanoparticles is the investigation of their dynamic properties. The chemical coprecipitation process was used to synthesize spherical magnetite nanoparticles of 14 nm. The as-prepared magnetite nanoparticles have been aged in the matrix. Magnetic properties and aging effect were studied by Mössbauer spectroscopy at temperatures ranging from 77 to 300 K, and X-ray diffraction. At room temperature, the Mössbauer spectrum showed superparamagnetic behavior of the particles, while well-defined sextets were observed at 77K, indicating a blocked regime. The superparamagnetic magnetite nanoparticles can be used as microbead biosensors.


Assuntos
Compostos Férricos/química , Fenômenos Magnéticos , Nanopartículas de Magnetita/química , Nanocompostos/química , Polímeros/química , Polímeros/síntese química , Espectroscopia de Mossbauer , Temperatura , Difração de Raios X
11.
Int J Pediatr Otorhinolaryngol ; 75(10): 1255-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21820188

RESUMO

BACKGROUND: Velocardiofacial syndrome (VCFS) is the most common genetic syndrome associated with cleft palate. There are reports describing several anomalies associated with the palatal cleft in patients with VCFS, which can affect the characteristics of the velopharyngeal insufficiency (VPI) in these cases. OBJECTIVE: The purpose of this study is to assess velopharyngeal sphincter function during speech, using videonasopharyngoscopy (VNP) and videofluoroscopy (VF), in patients with VCFS, as compared with patients with non-syndromic palatal clefts (NSCP). MATERIAL AND METHOD: Twenty patients with VCFS corroborated by a FISH test were studied. All patients showed a palatal cleft. All patients had received previous management including speech therapy and palatal repair. These patients underwent a thorough clinical speech evaluation, including VNP and VF. Twenty patients with NSCP matched by sex, type of cleft and within the age range of the patients with VCFS were studied as controls. RESULTS: From the patients with VCFS, seventeen patients showed a submucous cleft palate. Three patients showed sub-total cleft of the secondary palate. Fourteen patients (70%) showed a coronal velopharyngeal closure pattern. Six patients (30%) showed a circular pattern. In contrast, 10 patients (50%) from the NSCP group showed a circular pattern, two of them showed a Passavant's ridge. Seven patients (35%) showed a coronal pattern and 3 patients (15%) showed a saggital pattern. Mean velum (V) and lateral pharyngeal wall (LPW) motion were significantly decreased in patients with VCFS (V=46% vs 71%; LPW=14% vs 30%; P<0.001). Size of the defect during speech was significantly increased in patients with VCFS (34.57% vs 67.37%; P<0.001). CONCLUSION: Velopharyngeal valving during speech is significantly different in patients with VCFS as compared with patients with NSCP. Several anomalies associated with the palatal cleft in patients with VCFS can explain these differences. Thus, the surgical approach for repairing a palatal cleft should consider these differences. Moreover, surgical planning should be performed according to the specific findings of the velopharyngeal sphincter in order to improve speech outcome.


Assuntos
Síndrome de DiGeorge/complicações , Síndrome de DiGeorge/fisiopatologia , Fala/fisiologia , Insuficiência Velofaríngea/diagnóstico , Insuficiência Velofaríngea/epidemiologia , Esfíncter Velofaríngeo/fisiopatologia , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Cinerradiografia , Fissura Palatina/complicações , Fissura Palatina/diagnóstico , Fissura Palatina/fisiopatologia , Síndrome de DiGeorge/diagnóstico , Feminino , Humanos , Masculino
12.
Neotrop Entomol ; 39(5): 686-90, 2010.
Artigo em Espanhol | MEDLINE | ID: mdl-21120373

RESUMO

The purpose of this research was to demonstrate the dependant relationship between the Argentine ant Linepithema humile Mayr, plant coverage, and human settlements. A method was designed in order to sample the presence of the Argentine ant and other ant species that may had influenced L. humile distribution, under different types of vegetation and percentages of plant coverage, taking in consideration the distance from human settlements. Eight sample stations were established. Four of these stations were found on a dwelling home and the other four were found on similar areas, but far from human settlements. Three transects were established from the center of each sampling station (Tt1, shrublike vegetation, Tt2, herblike vegetation and Tt3, no vegetation). Transects were compound by 10 m side quadrants. A negative correlation was found between nest number of L. humile and human settlement distance, therefore nests were not found at distances higher than 80 m, in all studied areas. There was a positive and significant correlation between nest number of L. humile and plant coverage percentage, regardless the type of vegetation found. The same trend was found for other ant species studied in the area. Finally, it was proved that the distribution of L. humile nests is not influenced by other ant species.


Assuntos
Formigas , Ecossistema , Comportamento de Nidação , Animais , Argentina , Chile
13.
Neotrop. entomol ; 39(5): 686-690, Sept.-Oct. 2010. tab
Artigo em Espanhol | LILACS | ID: lil-566202

RESUMO

The purpose of this research was to demonstrate the dependant relationship between the Argentine ant Linepithema humile Mayr, plant coverage, and human settlements. A method was designed in order to sample the presence of the Argentine ant and other ant species that may had influenced L. humile distribution, under different types of vegetation and percentages of plant coverage, taking in consideration the distance from human settlements. Eight sample stations were established. Four of these stations were found on a dwelling home and the other four were found on similar areas, but far from human settlements. Three transects were established from the center of each sampling station (Tt1, shrublike vegetation, Tt2, herblike vegetation and Tt3, no vegetation). Transects were compound by 10 m side quadrants. A negative correlation was found between nest number of L. humile and human settlement distance, therefore nests were not found at distances higher than 80 m, in all studied areas. There was a positive and significant correlation between nest number of L. humile and plant coverage percentage, regardless the type of vegetation found. The same trend was found for other ant species studied in the area. Finally, it was proved that the distribution of L. humile nests is not influenced by other ant species.


Assuntos
Animais , Formigas , Ecossistema , Comportamento de Nidação , Argentina , Chile
14.
Avian Dis ; 53(2): 250-4, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19630232

RESUMO

A combination of three different Salmonella-specific bacteriophages (BPs) and one competitive exclusion (CE) product were used to reduce Salmonella Enteritidis (SE) colonization in experimentally infected chickens. Equal numbers of 7-day-old chickens were used in each of three groups: a CE group (treated with CE), a BP group (treated with BP), and a CE-plus-BP group (treated with both products). The CE product was administered via coarse spray at 1 day of age and the cocktail of three BPs was given via spray at 6 days of age using a multiplicity of infection of 10(3) plaque-forming units. All the experimental groups, except a healthy control group, were challenged orally with 2.95 x 10(5) colony-forming units (CFU)/ml of an SE strain at 7 days of age. Seven days postchallenge, the chickens were euthanatized for individual SE detection, quantitative bacteriology, and phage isolation from ceca and an internal organ pool. The qualitative bacteriology demonstrated that the use of the CE product diminished the incidence of SE to 75.7% and the mixture of BPs reduced it to 80%; when CE plus BP were used, the incidence dropped significantly to 38.7% (P < 0.0001), as compared with the infection control group (100%). A significant difference in the incidence was observed between the CE and the CE-plus-BP groups, and the BP and the CE-plus-BP groups (P = 0.0027 and P = 0.0010, respectively). The mean SE cecal count diminished with the use of CE plus BP (1.6 x 10(2) CFU/g, P = 0.0003) compared with the control group (1.56 x 10(5) CFU/g), the CE group (4.23 x 10(3) CFU/g), and the BP group (9.48 x 10(3) CFU/g). On the basis of the present study, it may be concluded that the use of both types of biocontrollers can be an effective method for reducing SE colonization in commercial chickens, but further basic and applied research is needed.


Assuntos
Galinhas , Doenças das Aves Domésticas/prevenção & controle , Probióticos , Salmonelose Animal/prevenção & controle , Fagos de Salmonella/fisiologia , Salmonella enteritidis/virologia , Aerossóis , Animais
15.
Neuroscience ; 163(1): 180-9, 2009 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-19524025

RESUMO

Sympathetic preganglionic neurons (SPN) coexpress the acetylcholine (ACh)-synthesizing enzyme choline acetyltransferase and different peptides in their cell bodies, but can express them independently in separate varicosities, indicating that SPN segregate transmitters to different synapses. Consequently, there are populations of preganglionic varicosities (peptidergic and noncholinergic) that store peptides but not ACh. We studied in the cell bodies and axon processes of the rat SPN the expression and the proportional coexpression of the vesicular ACh transporter-like immunoreactivity (VAChT), a specific marker of cholinergic synaptic vesicles or ChAT-like immunoreactivity (ChAT), and the peptide methionine enkephalin-like immunoreactivity (mENK), and confirmed the presence of a population of SPN peptidergic, noncholinergic varicosities. We characterized these varicosities by exploring the occurrence of synaptophysin-like immunoreactivity (Syn), a marker of small clear vesicles, and synaptotagmin-like immunoreactivity (Syt), a preferential marker of large dense core vesicles. We found that (i) VAChT and mENK, like ChAT-mENK, were coexpressed in only 59% of the mENK-containing varicosities, although they colocalized in the SPN cell bodies; and (ii) almost 60% of the population of mENK-containing varicosities did not express Syn or Syt, and over 80% of the mENK-containing varicosities negative for VAChT also lacked Syn. These data prove that SPN segregate mENK from VAChT and ChAT, and show that most of the subset of mENKergic varicosities negative for VAChT also does not express Syn, suggesting the presence of a different vesicular pattern in these sympathetic preganglionic varicosities.


Assuntos
Acetilcolina/metabolismo , Colina O-Acetiltransferase/metabolismo , Encefalina Metionina/metabolismo , Gânglios Simpáticos/metabolismo , Terminações Pré-Sinápticas/metabolismo , Proteínas Vesiculares de Transporte de Acetilcolina/metabolismo , Animais , Gânglios Simpáticos/ultraestrutura , Imuno-Histoquímica , Masculino , Terminações Pré-Sinápticas/ultraestrutura , Ratos , Ratos Wistar , Transmissão Sináptica/fisiologia , Sinaptofisina/metabolismo , Sinaptotagminas/metabolismo
16.
J Toxicol ; 2009: 287247, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20107583

RESUMO

Due to their natural origin, apparent low oral toxicity, effectiveness, and accessibility without a medical prescription, the anthranoid laxatives are a popular remedy for constipation and are frequently used abusively. Therefore, it is important to characterize its harmful and/or toxic effects. The sennosides, main active metabolites of senna, exhibit a very low toxicity in rats, and its genotoxic activity in bacterial strains as well as mammal cells was classified as weak in those cases where it was shown to be significant. The toxicological and mutagenic status of the crude extract of senna, however, is not as well characterized, and it is necessary to do so since it is frequently, and at the same time incorrectly, believed that the chronic use of anthranoid laxatives is a risk factor for the development of colorectal cancer. The objective of this article was to review the information that arises in various scientific medical databases using key words such as senna, sen, Senna alexandrina, Cassia angustifolia, sennosides, laxative toxicity, mainly ISI and non-ISI articles of journals with an editorial committee. Web pages of products or companies that publicize or commercialize this type of laxative were not included. This analysis establishes that (1) there is no convincing evidence that the chronic use of senna has, as a consequence, a structural and/or functional alteration of the enteric nerves or the smooth intestinal muscle, (2) there is no relation between long-term administration of a senna extract and the appearance of gastrointestinal tumors or any other type in rats, (3) senna is not carcinogenic in rats even after a two-year daily dose of up to 300 mg/kg/day, and (4) the current evidence does not show that there is a genotoxic risk for patients who take laxatives containing senna extracts or sennosides.

17.
Chemosphere ; 72(5): 722-5, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18495201

RESUMO

Numerous potentially mutagenic chemicals have been studied mainly because they can cause damaging and inheritable changes in the genetic material. Several tests are commonly used for biomonitoring pollution levels and to evaluate the effects of toxic and mutagenic agents present in the natural environment. This study aimed at assessing the potential of a textile effluent contaminated with azo dyes to induce chromosomal and nuclear aberrations in Allium cepa test systems. A continuous exposure of seeds in samples of the textile effluent in different concentrations was carried out (0.3%, 3%, 10%, and 100%). Cells in interphase and undergoing division were examined to assess the presence of chromosome aberrations, nuclear changes, and micronuclei. Our results revealed a mutagenic effect of the effluent at concentrations of 10% and 100%. At lower concentrations, the effluent (3% and 0.3%) did not induce mutagenic alterations in the test organism A. cepa. These findings are of concern, since cell damage may be transmitted to subsequent generations, possibly affecting the organism as a whole, as well as the local biota exposed to the effluent discharge. If the damage results in cell death, the development of the organism may be affected, which could also lead to its death.


Assuntos
Compostos Azo/toxicidade , Aberrações Cromossômicas/induzido quimicamente , Corantes/toxicidade , Resíduos Industriais/análise , Cebolas/genética , Indústria Têxtil , Poluentes Químicos da Água/toxicidade , Poluição Química da Água/análise , Compostos Azo/análise , Brasil , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/patologia , Sobrevivência Celular/efeitos dos fármacos , Corantes/análise , Monitoramento Ambiental/métodos , Testes para Micronúcleos , Cebolas/efeitos dos fármacos , Sementes/efeitos dos fármacos , Poluentes Químicos da Água/análise
18.
Avian Dis ; 52(1): 64-7, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18459298

RESUMO

Three different lyric bacteriophages (BPs) were isolated from the sewage system of commercial chicken flocks and used to reduce Salmonella Enteritidis (SE) colonization from experimental chickens. Ten-day-old chickens were challenged with 9.6 x 10(5) colony-forming units (CFU)/ml of a SE strain and treated by coarse spray or drinking water with a cocktail of the three phages at a multiplicity of infection (MO1) of 10(3) plaque-forming units (PFU) 24 hr prior to SE challenge. Chickens were euthanatized at day 20 of age for individual SE detection, quantitative bacteriology, and phage isolation from the intestine and from a pool of organs. SE detection was performed by both bacteriologic culture and genome detection by polymerase chain reaction (PCR). Qualitative bacteriology showed that aerosol-spray delivery of BPs significantly reduced the incidence of SE infection in the chicken group (P = 0.0084) to 72.7% as compared with the control group (100%). In addition, SE counts showed that phage delivery both by coarse spray and drinking water reduced the intestinal SE colonization (P < 0.01; P < 0.05, respectively). BPs were isolated at 10 days postinfection from the intestine and from pools of organs from BP-treated chickens. We conclude that the phage treatment, either by aerosol spray or drinking water, may be a plausible alternative to antibiotics for the reduction of Salmonella infection in poultry.


Assuntos
Portador Sadio/veterinária , Galinhas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Salmonelose Animal/prevenção & controle , Fagos de Salmonella/fisiologia , Salmonella/virologia , Animais , Portador Sadio/prevenção & controle
19.
Dev Neurobiol ; 67(5): 589-602, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17443810

RESUMO

Calcium involved in basal ganglionic transmission and long-term potentiation (LTP) can arise either by influx from the extracellular medium or release from intracellular stores. No attempts have yet been made to concurrently explore the contributions of extracellular and intracellular Ca2+ to basal ganglionic transmission or LTP. Here, we investigate this subject using the superior cervical ganglion of the rat. To explore the extracellular Ca2+ contribution, we evaluated basal transmission and LTP at different extracellular Ca2+ concentrations. To assess intracellular Ca2+ release, we explored the contribution of the calcium-induced calcium release process by overactivation or blockade of ryanodine-sensitive Ca2+ receptor channel with caffeine, and also by blocking either IP3R with Xestospongin C or the sarco(endo)plasmic reticulum Ca2+-ATPase pump with thapsigargin. Extracellular Ca2+ affected ganglionic basal transmission and LTP to different extents. While 25% of the physiological Ca2+ concentration supported 80% of basal transmission, 50% of normal Ca2+ was required to achieve 80% of LTP. Notably, disruption of intracellular Ca2+ release by all the drugs tested apparently did not affect basal ganglionic transmission but impaired LTP. We conclude that basal transmission requires only a small level of Ca2+ entry, while LTP expression not only requires more Ca2+ entry but is also dependent on Ca2+ release from intracellular stores.


Assuntos
Cálcio/metabolismo , Espaço Extracelular/fisiologia , Gânglios Simpáticos/fisiologia , Potenciação de Longa Duração/fisiologia , Transmissão Sináptica/fisiologia , Animais , Cafeína/farmacologia , Sinalização do Cálcio/fisiologia , Dantroleno/farmacologia , Relação Dose-Resposta a Droga , Estimulação Elétrica , Inibidores Enzimáticos/farmacologia , Receptores de Inositol 1,4,5-Trifosfato/antagonistas & inibidores , Compostos Macrocíclicos/farmacologia , Masculino , Oxazóis/farmacologia , Ratos , Ratos Wistar , Canal de Liberação de Cálcio do Receptor de Rianodina/efeitos dos fármacos , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/antagonistas & inibidores , Gânglio Cervical Superior/fisiologia , Tapsigargina/farmacologia
20.
Water Sci Technol ; 53(11): 11-6, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16862769

RESUMO

Abstract In the frame of the Petróleos Mexicanos Institutional Program for Sustainable Development, processes were evaluated in the manufacture operation of the petrochemical industry, with the purpose of reducing their ecological fingerprint. Thirteen cleaner production opportunities were registered in six process plants: ethylene oxide and glycols, acetaldehyde, ethylene, high density polyethylene, polypropylene switch and acrylonitrile, and 45 recommendations in the waste water treatment plant. Morelos is the second most important petrochemical complex in the Mexican and Latin American petrochemical industry. A tool was developed to obtain eco-efficiency indicators in operation processes, and as a result, potential savings were obtained based on best performance, as well as the integrated distribution of Sankey diagrams. Likewise, a mechanism of calculation to obtain economic savings based on the reduction of residues during the whole productive process is proposed. These improvement opportunities and recommendations will result in economic and environmental benefits minimising the use of water, efficient use of energy, raw materials and reducing residues from source, generating less environmental impacts during the process.


Assuntos
Indústria Química/métodos , Purificação da Água , Acetaldeído/química , Acrilonitrila/química , Indústria Química/instrumentação , Ecologia , Fontes Geradoras de Energia , Monitoramento Ambiental , Poluição Ambiental , Óxido de Etileno/química , Etilenos/química , Glicóis/química , México , Polietileno/química , Polipropilenos/química
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