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1.
Cult. cuid ; 24(56): 26-41, 2020. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-195769

RESUMO

INTRODUCCIÓN: El uso indebido de drogas es un importante problema de salud pública no solo en el Ecuador, sino también a nivel mundial. OBJETIVO: Interpretar las percepciones de la persona drogodependiente sobre los efectos que produce la droga en su vida personal, familiar, social, y su visión para el futuro. METODOLOGÍA: Investigación cualitativa con análisis interpretativo fenomenológico realizado mediante entrevistas semiestructuradas en muestreo no probabilístico tipo bola de nieve, a 17 sujetos con drogodependencia, en el periodo julio-agosto del 2018, en la ciudad de Guayaquil. RESULTADOS: Los informantes clave, tenían entre 16 a 28 años de edad, estrato social bajo, procedentes de zonas urbano-marginales, en su mayoría de instrucción secundaria incompleta, y con antecedentes de primer contacto con la droga en la adolescencia temprana y en la institución educativa. Se obtuvieron cinco categorías: contexto familiar y el entorno comunitario como factores causales del consumo; discriminación social como castigo a la persona adicta; culpa, soledad y autoestima baja; el tren de la adicción a las drogas destruye a su paso: salud y la vida; y el apoyo familiar y de un Ser Supremo como alternativas para salir de la adicción. CONCLUSIONES: Las causas del consumo de drogas fueron, entre otras: el escape de los problemas de su familia disfuncional y la vulnerabilidad adolescente en su búsqueda de identidad y pertenencia a un grupo. Por otra parte, relataron que se sienten discriminados y castigados por la sociedad, y vislumbran que les espera un futuro de muerte, cárcel, enfermedad e indigencia


INTRODUCTION: The abuse of drugs is an important public health problem not only in Ecuador, but also worldwide. OBJECTIVE: To interpret the perceptions of the drug-dependent person about the effects that the drug produces in their personal, family, social life, and their vision for the future. METHODOLOGY: Qualitative research with phenomenological interpretative analysis performed by semi-structured interviews in non-probabilistic sampling snowball type to 17 subjects with drug dependence in the period July-August 2018 in the city of Guayaquil. RESULTS: The key informants were between 16 and 28 years of age, with low social stratum, from marginal urban areas, mostly incomplete secondary education, and with a history of first contact with the drug in early adolescence and in educational institution. Five categories were obtained: Family context, and the community environment as causal factors of consumption; social discrimination as punishment for the addicted person; guilt, loneliness and low self-esteem; the train of addiction to drugs destroys in its path: health and life; and family support and a Supreme Being as alternatives to get out of addiction. CONCLUSIONS: The causes of drug use were among others: the escape from dysfunctional family problems and adolescent vulnerability in their search for identity and belonging to a group. On the other hand, they reported feeling discriminated against and punished by society, and they foresee that a future of death, prison, sickness and indigence awaiting them


INTRODUÇÃO: O abuso de drogas é um grande problema de saúde pública, não apenas no Equador, mas em todo o mundo. Alvo: Interpretar as percepções da pessoa dependente de drogas sobre os efeitos produzidos pela droga em sua vida pessoal, familiar, social e sua visão para o futuro. METODOLOGIA: Pesquisa qualitativa com análise interpretativa fenomenológica realizada por meio de entrevistas semi-estruturadas em amostragem sem probabilística de bolas de neve, para 17 sujeitos com dependência de drogas, no período de julho a agosto de 2018, na cidade de Guayaquil. RESULTADOS: Os informantes chave tinham entre 16 e 28 anos de idade, baixos estratos sociais, de áreas urbanas marginais, principalmente ensino médio incompleto, e com uma história de primeiro em contato com drogas no início da adolescência e na instituição de ensino. Cinco categorias foram obtidas: contexto familiar e o ambiente da comunidade como fatores causais do consumo; discriminação social como punição para a pessoa viciada; culpa, solidão e baixa auto-estima; o trem do tóxico dependência destrói o seu caminho: saúde e vida; e apoio familiar e um Ser Supremo como alternativas para sair do vício. CONCLUSÕES: as causas do uso de drogas foram, entre outros: a fuga de problemas familiares disfuncionais e a vulnerabilidade do adolescente em sua busca por identidade e pertencimento a um grupo. Por outro lado, relataram que se sentem discriminados e punidos pela sociedade, e prevêem que um futuro de morte, prisão, doença e indigência os espera


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Perfil de Impacto da Doença , Transtornos Relacionados ao Uso de Substâncias , Qualidade de Vida , Pesquisa Qualitativa , Problemas Sociais , Relações Familiares , Fatores de Risco , Meio Social , Equador
3.
Surgery ; 161(2): 477-484, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27614416

RESUMO

BACKGROUND: Advanced bipolar and ultrasonic devices have shown significant reduction in the surgical time of thyroid operations. This randomized, controlled trial assessed if operative time and other relevant outcomes are different for thyroidectomies performed either with a second-generation advanced bipolar device or traditional tie and suture technique. METHODS: Forty-one patients were randomized into 2 groups (advanced bipolar device and traditional tie and suture). Secondary end points included estimated blood loss, postoperative hemorrhage or hematoma requiring operative reintervention, recurrent laryngeal nerve injury, hypoparathyroidism, pain intensity, number of ligatures, analgesia usage, and loss of signal during recurrent laryngeal nerve monitoring. RESULTS: Preoperative characteristics were similar between both groups. Mean operative time in the advanced bipolar device group was reduced by 32.5 minutes compared with the traditional tie and suture group (P = .006). Intraoperative blood loss was similar in both groups. Four patients presented postoperative vocal cord dysmotility, 3 in the traditional tie and suture group and 1 in the advanced bipolar device group (P = ns). Two of these 4 patients also had a >50% amplitude decrease during continuous intraoperative neuromonitoring, 1 in each group. Pain intensity, 12 hours after operation, was significantly greater in the traditional tie and suture group (P = .015), even though pain medication requirements during the initial 24 hours after operation were similar between groups (P = .97). There were no cases of postoperative hemorrhage or hematoma requiring reintervention. Postoperative, symptomatic hypocalcemia occurred in 6 patients, 4 in the traditional tie and suture, and 2 in the advanced bipolar device group. One of them developed permanent hypocalcemia. CONCLUSION: The use of an advanced bipolar device in thyroid operation reduces operative time by >30 minutes, with a similar postoperative outcome profile when compared with the traditional tie and suture technique.


Assuntos
Perda Sanguínea Cirúrgica/prevenção & controle , Hemostasia Cirúrgica/instrumentação , Tireoidectomia/instrumentação , Tireoidectomia/métodos , Adulto , Análise de Variância , Feminino , Seguimentos , Hemostasia Cirúrgica/métodos , Humanos , Hipertireoidismo/patologia , Hipertireoidismo/cirurgia , Tempo de Internação/estatística & dados numéricos , Ligadura/métodos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Segurança do Paciente , Estatísticas não Paramétricas , Técnicas de Sutura , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/cirurgia , Resultado do Tratamento
4.
Pharmacol Biochem Behav ; 152: 30-35, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27461546

RESUMO

BACKGROUND: Testosterone protects male rats from Temporomandibular Joint (TMJ) pain. This study investigated whether this protective effect is mediated by an organizational action of testosterone during nervous system development, by central estrogen and androgen receptors and by the 5α-reduced metabolite of testosterone, dihydrotestosterone. METHODS: A pharmacological approach was used to assess the ability of the androgen receptor antagonist flutamide, the estrogen receptor antagonist ICI 182 780 and the 5-α reductase inhibitor dutasteride to block the protective effect of testosterone, evaluated through the behavioral response induced by a TMJ injection of 0.5% formalin. Flutamide and ICI 182 780 were injected into the medullary subarachnoid space, and dutasteride and testosterone were systemically administered. RESULTS: The TMJ injection of 0.5% formalin induced a significant nociceptive behavioral response in gonadectomized male and naïve female, but not in sham gonadectomized male rats, confirming that endogenous testosterone prevents TMJ nociception in males. Testosterone administration prevented formalin-induced TMJ nociception in males gonadectomized either in the neonatal (at the day of birth) or adult period and in naïve female rats, suggesting that the protective effect of testosterone on TMJ nociception does not depend on its organizational actions during critical periods of development. The administration of flutamide and dutasteride but not of ICI 182 780 blocked the protective effect of testosterone. CONCLUSIONS: We conclude that the protective effect of testosterone on TMJ nociception depends on activational actions of dihydrotestosterone on androgen receptors rather than on organizational androgenic actions during central nervous system development or estrogenic actions.


Assuntos
Inibidores de 5-alfa Redutase/farmacologia , Antagonistas de Androgênios/farmacologia , Medição da Dor/efeitos dos fármacos , Dor/prevenção & controle , Receptores Androgênicos/metabolismo , Articulação Temporomandibular/efeitos dos fármacos , Testosterona/farmacologia , Animais , Dutasterida/farmacologia , Estradiol/análogos & derivados , Estradiol/farmacologia , Antagonistas do Receptor de Estrogênio/farmacologia , Feminino , Flutamida/farmacologia , Formaldeído , Fulvestranto , Masculino , Ratos , Articulação Temporomandibular/fisiopatologia , Testosterona/antagonistas & inibidores
5.
Arch. alerg. inmunol. clin ; 44(1): 15-24, 2013. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-947443

RESUMO

Fundamento y objetivo. Comparar la eficacia y seguridad de ebastina 20 mg, ebastina 10 mg y loratadina 10 mg en monoterapia o en terapia combinada con fluticasona en el tratamiento de la rinitis persistente. Pacientes y método. Estudio prospectivo, comparativo, al azar, abierto, con grupos paralelos, en 36 pacientes con diagnóstico de rinitis alérgica persistente que fueron asignados primero a tres grupos: ebastina 20 mg (n=12), ebastina 10 mg + pseudoefedrina 120 mg (n=12), y loratadina 10 mg + pseudoefedrina 120 mg; posteriormente se reasignaron a 6 grupos en los que se trataron con ebastina 20 mg, ebastina 10 mg o loratadina 10 mg en monoterapia o terapia combinada con fluticasona nasal. Al término de cada fase se calificaron los síntomas de rinitis, y para evaluar la seguridad se practicaron biometría hemática, pruebas de funcionamiento hepático y ELISA para IL-4, IL-5 e IL-13. Resultados. No se observaron diferencias significativas entre los diferentes grupos de estudio en las pruebas realizadas para evaluar la eficacia y la seguridad de los tratamientos. Se observó al final del estudio una disminución significativa (p=0,003) en los niveles de IL-5 en el lavado nasal de los pacientes de todos los grupos de estudio. Conclusiones. Duplicar la dosis de ebastina a 20 mg fue tan seguro y eficaz como la combinación de la mitad de la dosis de esta (10 mg, con descongestionante nasal). La co-administración con fluticasona no mejoró la eficacia del tratamiento de la rinitis alérgica con antihistamínicos y se sugiere valorar como segunda opción en pacientes con pobre respuesta. Los tratamientos con ebastina 20 mg, ebastina 10 mg y loratadina 10 mg mostraron similar perfil de seguridad y eficacia.(AU)


Assuntos
Loratadina , Rinite Alérgica , Fluticasona , Antagonistas dos Receptores Histamínicos , Interleucina-3 , Receptores Tipo II de Interleucina-4
6.
Ciudad Autónoma de Buenos Aires; Ministerio de Salud de la Nación. Dirección de Investigación en Salud; 2013. 1 p.
Não convencional em Espanhol | ARGMSAL, BINACIS | ID: biblio-1526165

RESUMO

INTRODUCCIÓN En talleres realizados por la Unión Campesina del Oeste Serrano (Córdoba), se esbozaron problemas vinculados con la salud de las mujeres campesinas del sudoeste de Cruz del Eje y Minas, específicamente con la salud sexual y reproductiva (SSyR). La región en cuestión constituye una zona gris tiene restringido el acceso a la atención, ya que ningún municipio o comuna de las cercanías la incluye en su jurisdicción. OBJETIVOS Indagar, con una perspectiva de género e intercultural, la situación de SSyR en mujeres campesinas de la región. MÉTODOS La metodología de la investigación se basó en el monitoreo participativo. Se utilizó un diseño exploratorio-descriptivo, de corte transversal y de tipo cuali-cuantitativo. Se identificaron obstáculos, resistencias, impulsores y facilitadores por medio de una ruta crítica. RESULTADOS Se constataron obstáculos o barreras de accesibilidad a recursos en salud, tanto en lo económico como en lo geográfico y lo geopolítico. Se observó que, para el cuidado de sí, las mujeres apelan a los saberes y prácticas que conforman su memoria histórica. Esta transmisión se discontinúa entre las nuevas generaciones y como efecto del paradigma médico, asimismo, componen la base comunitaria presente en las estrategias de acceso a la atención como recurso crítico. DISCUSIÓN La noción de zona gris en torno a una situación geopolítica permite describir otros aspectos grises en la prevención, el conocimiento y la atención, que son poco accesibles pero se imponen como discurso de deber ser, en que el sistema no se adecua a las necesidades, saberes y demandas de salud de las mujeres campesinas. Lo mismo es válido para el silencio que rodea los temas sobre el cuerpo. Es imperioso adecuar el sistema de salud y la cobertura de los programas que interseccionan en SSyR, según la evaluación por parte de los colectivos de usuarias.


Assuntos
Saúde Reprodutiva
7.
Eur J Pain ; 16(2): 204-16, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22323373

RESUMO

We have recently demonstrated that gonadal steroid hormones decrease formalin-induced temporomandibular joint nociception in rats. Given that the attenuation of inflammation is a potential mechanism underlying this antinociceptive effect, we evaluated the effect of gonadal steroid hormones on formalin-induced temporomandibular joint inflammation. Plasma extravasation, a major sign of acute inflammation, and neutrophil migration, an important event related to tissue injury, were evaluated. Formalin induced significantly lower temporomandibular joint plasma extravasation and neutrophil migration in proestrus females than in males and in diestrus females. Since estradiol serum level is high in proestrus females and low in diestrus females and in males, these findings suggest that the high physiological level of estradiol decreases temporomandibular joint inflammation. Estradiol but not progesterone administration in ovariectomized females significantly decreased formalin-induced plasma extravasation and neutrophil migration, an effect that was blocked by the estrogen receptor antagonist ICI 182780. Plasma extravasation and neutrophil migration were not affected by orchiectomy, but testosterone or estradiol administration in orchidectomized males significantly decreased them. The androgen receptor antagonist flutamide blocked the anti-inflammatory effect of testosterone while ICI 182780 blocked that of estradiol in males. Previous intravenous administration of a nonspecific selectin inhibitor significantly decreased formalin-induced temporomandibular joint nociception and neutrophil migration in males, revealing a potent and positive correlation between temporomandibular joint nociception and inflammation. Taken together, these findings demonstrate a pronounced anti-inflammatory effect of estradiol and testosterone in the temporomandibular joint region and suggest that this effect may mediate, at least in part, the antinociceptive effect of these hormones.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Artrite/tratamento farmacológico , Artrite/patologia , Hormônios Esteroides Gonadais/farmacologia , Transtornos da Articulação Temporomandibular/tratamento farmacológico , Transtornos da Articulação Temporomandibular/patologia , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite/metabolismo , Modelos Animais de Doenças , Feminino , Hormônios Esteroides Gonadais/uso terapêutico , Masculino , Ratos , Ratos Wistar , Transtornos da Articulação Temporomandibular/metabolismo , Resultado do Tratamento
8.
Neuroscience ; 164(2): 724-32, 2009 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-19679171

RESUMO

Recently, we have reported that high physiological estradiol level during the proestrus phase of the estrous cycle or systemic estradiol administration in ovariectomized rats decreases formalin-induced temporomandibular joint nociception. However, the mechanisms underlying the antinociceptive effect of estradiol are presently unknown. In this study, we used the temporomandibular joint formalin model in rats to investigate whether estradiol decreases nociception by a peripheral non-genomic mechanism, and if so, whether this mechanism is mediated by the activation of the nitric oxide-cyclic guanosine monophosphate signaling pathway and of opioid receptors. The administration of estradiol into the ipsilateral, but not into the contralateral temporomandibular joint significantly reduced formalin-induced temporomandibular joint nociception in ovariectomized and diestrus but not in proestrus females. However, the administration of the estrogen receptor antagonist ICI 182780 into the ipsilateral, but not into the contralateral temporomandibular joint blocked the antinociceptive effect of serum estradiol in proestrus females, suggesting that the physiological effect of estradiol in nociception is mediated, at least in part, by a peripheral mechanism. The administration of estradiol into the ipisilateral temporomandibular joint did not affect formalin-induced nociception in male rats. The antinociceptive effect of temporomandibular joint estradiol administration in ovariectomized and diestrus females was mimicked by estradiol conjugated with bovine serum albumin, which does not diffuse through the plasma membrane, and was blocked by the estrogen receptor antagonist ICI 182780. The administration of the nitric oxide synthase inhibitor (nitro-l-arginine) or of a guanylate cyclase inhibitor (1H-(1,2,4)-oxadiasolo (4,2-a) quinoxalin-1-one) into the ipsilateral, but not into the contralateral temporomandibular joint blocked the antinociceptive effect of estradiol and of estradiol conjugated with bovine serum albumin, while the opioid receptor antagonist naloxone had no effect. These findings suggest that estradiol decreases temporomandibular joint nociception in female rats through a peripheral non-genomic activation of the nitric oxide-cyclic guanosine monophosphate signaling pathway.


Assuntos
Analgésicos/farmacologia , GMP Cíclico/metabolismo , Estradiol/farmacologia , Óxido Nítrico/metabolismo , Dor/tratamento farmacológico , Articulação Temporomandibular/efeitos dos fármacos , Analgésicos/sangue , Animais , Diestro/efeitos dos fármacos , Diestro/metabolismo , Estradiol/sangue , Feminino , Formaldeído , Guanilato Ciclase/antagonistas & inibidores , Guanilato Ciclase/metabolismo , Masculino , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Ovariectomia , Dor/induzido quimicamente , Dor/metabolismo , Proestro/efeitos dos fármacos , Proestro/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais , Articulação Temporomandibular/metabolismo
9.
Reprod Toxicol ; 15(2): 137-44, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11297873

RESUMO

The psoralens occur naturally in produce and are widely used in skin therapy. Studies show that 5-methoxypsoralen and 8-methoxypsoralen reduced birth rates in rats. We determined the effect of psoralens on reproductive function in male rats. Male Wistar rats were dosed daily with 5-methoxypsoralen or 8-methoxypsoralen (75 or 150 mg/kg, p.o.), or vehicle control. Treated males had significantly smaller pituitary glands, fewer sperm per ejaculate, and fewer sperm in the vasa defferentia and epididymides than controls. Dosing significantly elevated levels of testosterone and increased relative testis weight, but did not directly affect testicular weight. Females bred to dosed males required more time to become pregnant, and these males required more breeding attempts. The findings demonstrate the importance of determining the potential risk for infertility and/or birth defects in humans who are exposed to therapeutic, dietary, or occupational psoralens.


Assuntos
Metoxaleno/toxicidade , Reprodução/efeitos dos fármacos , 5-Metoxipsoraleno , Administração Oral , Animais , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Relação Dose-Resposta a Droga , Feminino , Fertilidade/efeitos dos fármacos , Genitália Masculina/efeitos dos fármacos , Genitália Masculina/metabolismo , Genitália Masculina/patologia , Masculino , Metoxaleno/administração & dosagem , Metoxaleno/análogos & derivados , Tamanho do Órgão/efeitos dos fármacos , Exposição Paterna , Hipófise/efeitos dos fármacos , Hipófise/patologia , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Reprodução/fisiologia , Comportamento Sexual Animal/efeitos dos fármacos , Contagem de Espermatozoides , Testosterona/sangue
10.
J Nat Toxins ; 8(2): 167-77, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10410328

RESUMO

The psoralens are photoactivated plant biosynthetic compounds which are found in several plant families, including common fruits and vegetables. Synthetic forms of the psoralens bergapten (5-methoxypsoralen) and xanthotoxin (8-methoxypsoralen) are extensively used in skin chemotherapy in combination with long-wave ultraviolet radiation (PUVA). Side effects of PUVA therapy are not, however, desirable, and this therapy has been linked with increased incidence of skin cancer in humans. The psoralens are known to be carcinogenic, mutagenic and teratogenic, and to cause photodermatitis. The main objective of this study was to document the effect of PUVA on the epidermis of rats. Female Wistar rats were administered dietary bergapten and/or xanthotoxin (0-200 mg/kg body) and exposed to UVA radiation (45 min./day) for four weeks. At the end of the four-week period the rats were sacrificed; skin samples were taken from the ears and the top part of the tail and fixed for examination by Scanning Electron Microscopy. The animals subjected to PUVA had significantly smaller scales on the tail epidermis (mean scale size for the control 926 mu vs. 725 to 805 mu for the psoralen treatment groups. The rats that received dietary psoralens also had significantly less hair on the ears compared with the control animals (mean number of hairs per millimeter over the ear edge for the control 54.9 vs. 2.00 to 10.7 for the treatment groups). The two compounds were synergistic in their ability to reduce scale size on the tail epidermis.


Assuntos
Terapia PUVA/efeitos adversos , Transtornos de Fotossensibilidade/etiologia , 5-Metoxipsoraleno , Animais , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Feminino , Cabelo/efeitos dos fármacos , Metoxaleno/análogos & derivados , Metoxaleno/toxicidade , Microscopia Eletrônica de Varredura , Fármacos Fotossensibilizantes/toxicidade , Ratos , Ratos Wistar
11.
J Biochem Mol Toxicol ; 13(3-4): 195-203, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10098905

RESUMO

The psoralens are naturally occurring metabolites found in many crop plants; synthetic forms of 5-methoxypsoralen (bergapten) and 8-methoxypsoralen (xanthotoxin) are widely used in skin photochemotherapy. Our previous research documented that dietary bergapten and xanthotoxin reduced birthrates in female rats when males and females were exposed to these chemicals. The present study was designed to determine the cause of this reduced birthrate and whether this resulted from direct impact on the females. The study demonstrates that bergapten and xanthotoxin administered, either alone or in combination to female rats (mated to undosed males), significantly reduced the number of implantation sites, pups, and corpora lutea in dosed females compared with control animals. Additionally, full uterine weight and empty uterine weight were significantly reduced. These compounds also significantly reduced circulating estrogen levels in a dose-dependent manner. Interestingly, the psoralens significantly induced mRNAs of liver enzymes typically induced by polycyclic aromatic hydrocarbons, CYP1A1 and UGT1A6; the higher the dose, the greater the induction. UGT 2B1 mRNA, typically induced by phenobarbital-like compounds, was not significantly affected. Thus, enhanced oxidative metabolism and conjugation of estrogens in psoralen-treated animals may provide a partial explanation for the effects observed. These findings are also consistent with psoralen-induced reduction in ovarian follicular function and ovulation.


Assuntos
Furocumarinas/toxicidade , Ovário/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Tamanho da Ninhada de Vivíparos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Tamanho do Órgão/efeitos dos fármacos , Gravidez , Ratos , Ratos Wistar , Útero/efeitos dos fármacos
14.
Rev Latinoam Microbiol ; 33(1): 61-70, 1991.
Artigo em Espanhol | MEDLINE | ID: mdl-1670256

RESUMO

Resistance to toxic heavy metals has been found in bacteria from clinical and environmental origins. The genetic determinants of resistance are frequently located on plasmids or transposons. Several heavy metal resistance genes have been cloned and sequenced. The mechanisms of resistance to heavy metals are commonly based on novel membrane transport systems that expel the toxic ions (including cobalt, nickel, zinc, and probably copper and chromium) from the bacterial cytoplasm. Arsenic and cadmium ions are effluxed from the cells by specific membrane ATPases encoded by resistance plasmids. Reduction of mercuric ions to the volatile metallic form by a plasmid-coded enzyme is responsible for mercury resistance. Studies on other resistance determinants (e.g., antimony, bismuth, boron, lead, silver, tin, tellurium) have been reported but the mechanisms of resistance are still unknown.


Assuntos
Bactérias/efeitos dos fármacos , Metais/farmacologia , Resistência Microbiana a Medicamentos
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