Paresia unilateral do terceiro nervo após uso de Metronidazol oral / Unilateral third nerve palsy after use of oral Metronidazole

Resumo Paciente do sexo feminino, 19 anos, com queixa de diplopia, náusea e vômito de início súbito. Ao exame físico, a paciente apresentava rotação da cabeça para a esquerda e limitação da adução do olho direito, sugerindo paresia do músculo reto medial. Ausência de ptose palpebral ou paresia de outra musculatura ocular extrínseca e sem outras alterações na avaliação oftalmológica. Foi relatado pelo paciente o uso de Metronidazol, duas doses de 500 mg, no mesmo dia em que os sintomas começaram. A ressonância magnética do crânio foi solicitada. O resultado mostrou um cisto da glândula pineal, estando os outros aspectos dentro da normalidade. A paresia do músculo reto medial e diplopia persistiram por 14 dias, mesmo após a suspensão do antibiótico, optando, assim, por iniciar a corticoterapia oral, evoluindo com boa resposta clínica, melhora dos sintomas e regressão da paresia muscular.

Abstract Female patient, 19 years old, with a complaint of diplopia, nausea and vomiting of sudden onset. Upon physical examination, the patient presented herself with the head position rotated to the left and limitation of adduction of the right eye, suggesting paresis of the medial rectus muscle. Absence of palpebral ptosis or paresis of other extrinsic musculature of the eye, and without other alterations in the ophthalmological evaluation. It was reported by the patient the use of Metronidazole, two doses of 500 mg, the same day the symptoms started. The magnetic resonance imaging of the skull was requested. The result showed a cyst of the pineal gland, the other aspects being within normality. The paresis of the medial rectus muscle and diplopia persisted for 14 days, even after the antibiotic was discontinued, thus opting to initiate oral corticosteroid therapy, evolving with good clinical response, improvement of symptoms and regression of muscular paresis.

Cytotoxicity of intracanal dressings on apical papilla cells differ upon activation with E. faecalis LTA

Abstract Objective The aim of this study was to investigate the cytotoxic effects of modified triple antibiotic paste and an experimental composition using calcium hydroxide on lipoteichoic acid (LTA)-primed apical papilla cells (APC). Material and Methods Human APC were tested for in vitro cytotoxicity of modified Triple Antibiotic Paste (mTAP - Ciprofloxacin, Metronidazole and Cefaclor at 1:1:1) and of a paste of Ciprofloxacin, Metronidazole and Calcium hydroxide (CMC - 1:1:2) and modified CMC (mCMC - 2:2:1) by using MTT assay. The substances were reconstituted in DMEM at 1,000 µg/mL and » serially diluted before being kept in contact with cells for 1, 3, 5 and 7 days. Further, cells were primed with 1 µg/mL of Enterococcus faecalis LTA for 7 days prior to the viability test with 1,000 µg/mL of each substance. Statistical analysis was performed using one-way analysis of variance (ANOVA) and two-way ANOVA respectively followed by Tukey's post-test. Significance levels were set at p<0.05. Results In the first assay, the higher cytotoxic rates were reached by mTAP for all experimental periods. CMC was found toxic for APC at 5 and 7 days, whereas mCMC did not affect the cell viability. Only CMC and mCMC were able to induce some cellular proliferation. In the second assay, when considering the condition with medium only, LTA-primed cells significantly proliferated in comparison to LTA-untreated ones. At this context, mTAP and CMC showed similar cytotoxicity than the observed for LTA-untreated cells, while mCMC was shown cytotoxic at 7 days only for LTA-primed APC. Comparing the medications, mTAP was more cytotoxic than CMC and mCMC. Conclusion mTAP showed higher cytotoxicity than CMC and mCMC and the effect of topic antimicrobials might differ when tested against apical papilla cells under physiological or activated conditions.

Toxic concentrations of metronidazole to Microcystis protocystis / Concentrações tóxicas de metronidazol para Microcystis protocystis

Antimicrobials are among the most commonly used drugs and have become a class of contaminants with great environmental importance. Metronidazole is an antimicrobial used for the therapeutic management of several human diseases. The toxicity of antimicrobials on aquatic species may affect sensitive microorganisms and reduce metabolic processes. Cyanobacteria is a group of organisms that are of great ecological importance in aquatic environments. Studies indicate that cyanobacteria are very sensitive to some antimicrobials. Therefore, it is necessary to evaluate the effects of metronidazole contamination on phytoplankton. The aim of this study was to investigate the effects of metronidazole on the growth of the cyanobacterium Microcystis protocystis and to evaluate the stability of this antimicrobial agent in the culture medium over a period of 96 hours. M. protocystis was resistant to growth inhibition by metronidazole. The EC50 of this antimicrobial for M. protocystis was 117.3 mg L–1. Under the growth inhibition test conditions, neither a significant change in the MNZ concentration nor the presence of drug metabolites or degradation products was observed. These results indicate low cellular uptake of the antimicrobial agent and its persistence in the culture medium.

Antimicrobianos estão entre os fármacos mais usados e tem se tornado uma classe emergente de contaminantes com grande importância ambiental. A toxicidade dos antimicrobianos sobre as espécies aquáticas podem afetar microrganismos sensíveis e reduzir seus processos metabólicos. O Metronidazol é um antimicrobiano usado para o manejo terapêutico de várias doenças humanas. Cyanobacteria é um grupo de organismos de grande importância ecológica no ambiente aquático. O estudo visou investigar os efeitos do metronidazol- MNZ sobre o crescimento da cianobactéria Microcystis protocystis e avaliar a persistência do antimicrobiano no meio de cultivo durante 96h. A M. protocystis mostrou-se resistente à inibição de crescimento pelo MNZ. A EC50% do MNZ para a espécie foi 117,3 mg L–1. Nas condições do teste de inibição de crescimento não foi observada variação significativa da concentração de MNZ nem a presença de metabólitos ou produtos de degradação do fármaco, indicando baixa captação celular do antimicrobiano e sua persistência no meio de cultivo.

Time- and concentration-dependent cytotoxicity of antibiotics used in endodontic therapy

OBJECTIVE: New drugs have to be assessed in endodontic therapy due to the presence of microorganisms resistant to therapeutic procedures. Thus, this study evaluated the time- and concentration-dependent cytotoxicity of different antibiotics used in endodontic therapy. MATERIAL AND METHODS: Human gingival fibroblasts were treated and divided into the following experimental groups: Group I - control; Group II - ciprofoxacin hydrochloride; Group III - clyndamicin hydrochloride; and Group IV - metronidazole. Each drug was used at concentrations of 5, 50, 150, and 300 mg/L for 24, 48, 72, and 96 h. Cytotoxicity was evaluated by the MTT assay [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and spectrophotometric reading of ELISA plates. The results were analyzed by BioEstat 4.0 software using Kruskal-Wallis and Dunn's tests at a signifcance level of 5 percent. Cell viability was assessed for the different concentrations and times. RESULTS: All drugs presented dose-dependent cytotoxicity. Concentrations of 5 and 50 mgjL produced viable fibroblasts at all experimental times in all groups. CONCLUSIONS: Cell viability at 24 h was greater than in the other experimental times. Comparison between the same concentrations of antibiotics at different times showed that metronidazole presented the highest cell viability at 72 and 96 h compared to the other antibiotics, whereas clyndamicin hydrochloride showed higher cell viability at 72 h than ciprofoxacin hydrochloride.

Effect of metronidazole on spermatogenesis and FSH, LH and testosterone levels of pre-pubertal rats.

Metronidazole, a 5-nitroimidazole drug has been reported to decrease testicular weight, testicular and epididymal spermatid counts and causes abnormal sperm morphology with degeneration of seminiferous tubules with 6 weeks treatment of metronidazole (400 mg/kg, day). In contrast to DNA flow cytometry (FCM), the histological and gravimetric parameters do not allow a rapid, sensitive, objective and multiparameteric evaluation of reproductive toxicants on spermatogenesis. Moreover, the exact mechanisms for such an effect are not entirely clear. The present study was therefore undertaken to assess the effects of intraperitoneal (i.p.) administration of metronidazole 400 mg/kg daily for 30 days on testicular germ cell changes assessed by DNA (FCM) and hormone levels of testosterone, FSH and LH in pre-pubertal rats. A significant reduction in the haploid cell population in metronidazole treated groups as compared to saline treated controls was observed. The mean serum FSH, LH and testosterone value were also lowered in treated animals. Thus, the spermatotoxic effects of metronidazole were probably mediated by decrease in the circulating hormones responsible for spermatogenesis.

El índice mitótico y la cinética de proliferación linfocitaria en el monitoreo biológico / Mitotic index and kinetics of lymphocitary proliferation in the biologic monitoring

La exposición a xenobióticos es causa de perocupación sobre todo por sus posibles efectos sobre el ADN y la generación de cáncer. El largo tiempo de latencia entre la exposición y la manifestación clínica de sus efectos, de años y/o hasta generaciones, dificulta la identificación de estos agentes. Es por ello que el uso de biomarcadores se propone para el monitoreo biológico de individuos que por razones naturales, laborales, médicas o accidentales se consideran de alto riesgo. El presente trabajo evalúa la utilización de biomarcadores de proliferación celular en el cultivo de linfocitos de individuos expuestoa hidroarsencismo, desechos industriales peligrosos, pacientes con neurocisticercosis en tratamiento con praziquantel y en individuos a los que se les administró metronidazol. La utilidad de estos biomarcadores se pone en evidencia con los cambios en la proliferación linfocitaria en individuos expuestos toda su vida a altas concentraciones de arsénico en los que se ha reportado una mayor frecuencia de cáncer de pies y en pacientes con neurocisticercosis en los que la frecuencia de neoplasias es elevada. No encontramos alteraciones en la cinética de los individuos expuestos a desechos industriales, sin embargo, en los individuos tratados con metronidazol observamos un incremento en la velocidad de proliferación. El significado biológico de estos resultados abre nuevos campos de investigación