Efeitos sistêmicos provocados pelo peróxido de carbamida: estudo in vitro e in vivo / Systemic effects caused by carbamide peroxide: In vitro and in vivo study

Objetivos: Avaliar a citotoxicidade do peróxido de carbamida, em diferentes concentrações, para uma linhagem de células de hamster (estudo in vitro), bem como seus efeitos sistêmicos em um ensaio in vivo. Métodos: Utilizou-se teste de citotoxicidade pela análise de viabilidade celular, bem como a análise histoquímica do rim e do fígado, comparando o grupo controle e grupos testes, caracterizados pela ingestão de peróxido de carbamida na água de abastecimento em diferentes concentrações: 1,9mg/ml (teste1), 0,95mg/ml (teste 2), 0,71mg/ml (teste 3), 0,47mg/ml (teste 4) e 0,24mg/ml (teste 5) num período de 40 dias. Resultados: O agente clareador se mostrou altamente citotóxico nas concentrações de IC50 = 0,4mM. Além disso, foi observada alteração significativa no hemograma em relação à contagem de eritrócitos, no volume corpuscular médio, concentração de hemoglobina, contagem dos neutrófilos segmentados e número de linfócitos. Em relação às enzimas, na contagem de ureia, foram observadas alterações estatisticamente significativas entre o grupo controle e os grupos testes 1 e 2 (p=0.0000). Para a contagem de fosfatase alcalina, no vigésimo dia, foram encontrados resultados com diferença estatística entre o grupo controle e os grupos testes 2, 3, 4, e 5 (p=0.0009). Além disso, mudanças morfológicas no fígado e rim também foram observadas. Conclusão: O peróxido de carbamida, nas diferentes concentrações estudadas, determinou alterações sistêmicas significativas, demonstrando a importância de cautela no uso deste medicamento na Odontologia, a fim de evitar danos irreversíveis para a saúde do paciente.

Objectives: To evaluate the cellular cytotoxicity effects of carbamide peroxide at different concentrations in a hamster cell line in an in vitro study and its systemic effects in an in vivo assay. Methods: Cell cytotoxicity assay by cellular viability analysis and histochemical evaluation of kidney and liver morphology were performed comparing the control group and test groups, which were characterized by the ingestion of carbamide peroxide in the water supply at different concentrations: 1.9mg/ml 1), 0.95mg/ml (test 2), 0.71mg/ml (test 3), 0.47mg/ml (test 4) and 0.24mg/ml (test 5) for a period of 40 days. Results: The bleaching agent was cytotoxic at concentrations of IC50 = 0.4mM. In addition, a significant alteration of the blood count was observed in erythrocyte count, mean corpuscular volume, hemoglobin concentration, segmented neutrophil count and lymphocyte count. Regarding the enzymes, urea counts showed statistically significant changes between the control group and test groups 1 and 2 (Tukey index = 5.34, p = 0.0000) and alkaline phosphatase counts between the control group and the test groups 2, 3, 4, and 5 (Tukey's index = 10.72, p = 0.0009). Changes in liver and kidney morphology were also observed. Conclusion: Carbamide peroxide in the different concentrations studied can provide significant systemic alterations, demonstrating the importance of using this drug with caution in dentistry, in order to avoid irreversible damage to the patient.

The Incidence of Various Types of Systemic Reactions Related to Epidural Steroid Injections: A Prospective Observational Study

OBJECTIVE: To evaluate the incidence, types and association of systemic reactions after an epidural steroid injection (ESI) with patient demographics, ESI factors and repeated occurrence of an ESI. MATERIALS AND METHODS: This prospective observational study was approved by the Institutional Review Board of our hospital, and written informed consent was obtained from all the participants. From October to December 2011, systemic reactions at 2 weeks after 960 ESIs among 885 patients were measured. Patients were evaluated by phone interviews to obtain the patients' demographics, history of previous ESI, ESI factors, and ESI reoccurrence. Statistical analyses were performed using the chi-square tests, Fisher's exact tests and a binary logistic regression analysis. RESULTS: Overall, 557 types of systemic reactions occurred after 292 injections (30.4%) of a total of 960 ESIs in which facial flushing was most common (131/557, 23.5%) and 144 ESIs were followed by a mixed form of systemic reactions (49.3%). Age of 62 years or younger (odds ratio [OR], 2.361), female sex (OR, 1.674), and history of diabetes mellitus (OR, 1.681) were significant risk factors in the occurrence of systemic reactions after an ESI. In 73 patients with repeated ESI, 14 patients re-experienced systemic reactions (19.2%), of which twelve re-experienced the same systemic reaction as the previous one. CONCLUSION: Systemic reactions followed about 30% of ESIs, and more commonly occurred in patients 62 years of age or younger, women, and diabetic patients. Half of the patients experienced a mixed form of systemic reactions. Patients with recurring systemic reactions tend to re-experience the same systemic reaction as the prior one after an ESI.

Local and systemic effects of fibrin and cyanoacrylate adhesives on lung lesions in rabbits

OBJECTIVES: Tissue adhesives can be used to prevent pulmonary air leaks, which frequently occur after lung interventions. The objective of this study is to evaluate local and systemic effects of fibrin and cyanoacrylate tissue adhesives on lung lesions in rabbits. METHODS: Eighteen rabbits were submitted to videothoracoscopy + lung incision alone (control) or videothoracoscopy + lung incision + local application of fibrin or cyanoacrylate adhesive. Blood samples were collected and assessed for leukocyte, neutrophil and lymphocyte counts and interleukin-8 levels preoperatively and at 48 hours and 28 days post-operatively. After 28 days, the animals were euthanized for gross examination of the lung surface, and lung fragments were excised for histopathological analysis. RESULTS: Fibrin and cyanoacrylate produced similar adhesion scores of the lung to the parietal pleura. Microscopic analysis revealed uniform low-cellular tissue infiltration in the fibrin group and an intense tissue reaction characterized by dense inflammatory infiltration of granulocytes, giant cells and necrosis in the cyanoacrylate group. No changes were detected in the leukocyte, neutrophil or lymphocyte count at any time-point, while the interleukin-8 levels were increased in the fibrin and cyanoacrylate groups after 48 hours compared with the pre-operative control levels (p<0.01). CONCLUSION: Both adhesive agents promoted normal tissue healing, with a more pronounced local inflammatory reaction observed for cyanoacrylate. Among the serum markers of inflammation, only the interleukin-8 levels changed post-operatively, increasing after 48 hours and decreasing after 28 days to levels similar to those of the control group in both the fibrin and cyanoacrylate groups.

Effect of dacryocystorhinostomy on systemic adverse effects of topical timolol maleate.

Purpose: To evaluate whether transformation of the naso-lacrimal passage as happens after dacryocystorhinostomy (DCR) operation has any effect on the systemic adverse effects of topically administered timolol maleate. Materials and Methods: Fifty otherwise healthy adult patients without any prior history of cardiac or pulmonary problems scheduled for elective DCR surgery received a drop of timolol maleate 0.5% on the healthy eye. This eye served as a control. Six weeks after successful DCR surgery, the operated eye received the same medication. Parameters compared included intraocular pressure (IOP), pulse rate, blood pressure and forced expiratory volume in the first second (FEV1) findings. Observations: Post DCR patients showed an increased incidence of reduced pulse rate and FEV1. Conclusion: Timolol maleate ophthalmic preparation should be used with caution in post-DCR patients.