RESUMO
The aim of this study was to compare the ecotoxicity of nickel (Ni) and zinc (Zn) assayed as single and as binary mixture. In addition, how were affected the population growth rates and oxidative stress biomarkers, comparing single to binary exposures. The toxicity tests were performed on Lemna gibba using a 7-day test. All calculations were made using measured total dissolved metal concentrations. IC50-7d, based on growth rate calculated on frond number and fresh weight, were 2.47/3.89 mg/L, and 76.73/76.93 mg/L, for Ni and Zn, respectively. Single metals affected plant growth following a non-linear concentration-response relationship. LOEC values for each metal were obtained at 0.92 and 20.1 mg/L for Ni and Zn, respectively. Biomarkers of the antioxidant response like Catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPOX; EC 1.11.1.7) activities in single metals assays were higher than controls, but when similar concentrations were added as mixtures, that increase was reduced and inhibition with respect to the control was observed for GPOX. APOX showed the highest activity. The concentration addition (CA) approach was evaluated and resulted in a correct predictor of Ni-Zn mixture toxicity on Lemna gibba. This was made comparing the EC50 and LOEC, measured taking the growth rate as endpoint, with those expected values according to the CA model. However, the measured biomarkers indicating a positive response to free radicals did not fit to concentration addition model when assayed in the binary mixture. Also, the main activity response of these was observed within a range of concentrations below the LOEC values for the mixture.
Assuntos
Araceae/efeitos dos fármacos , Níquel/toxicidade , Estresse Oxidativo , Poluentes Químicos da Água/toxicidade , Zinco/toxicidade , Araceae/crescimento & desenvolvimento , Araceae/fisiologia , Biomarcadores/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Testes de ToxicidadeRESUMO
There is an increased concern about the health effects that air-suspended particles have on human health which have been dissected in animal models. Using CD-1 mouse, we explore the effects that vanadium inhalation produce in different tissues and organs. Our findings support the systemic effects of air pollution. In this paper, we describe our findings in different organs in our conditions and contrast our results with the literature.
Assuntos
Poluição do Ar/efeitos adversos , Material Particulado/toxicidade , Vanádio/toxicidade , Animais , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/patologia , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/patologia , Quebras de DNA de Cadeia Simples , Humanos , Sistema Imunitário/patologia , Inalação , Fígado/efeitos dos fármacos , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Linfonodos/efeitos dos fármacos , Linfonodos/patologia , Camundongos , Modelos Animais , Espécies Reativas de Oxigênio/metabolismo , Reprodução/efeitos dos fármacos , Baço/efeitos dos fármacos , Baço/patologiaRESUMO
OBJECTIVE: To describe an unusual case with clinical features of the antiphospholipid syndrome. DESCRIPTION: White child, two years and six months old, with renal failure, renal arterial thrombosis, and diagnosis of antiphospholipid syndrome was hospitalized with a history of abdominal pain, pallor, lethargy, and anuria for 36 hours. On physical examination, the patient showed malnutrition, high blood pressure, moderate edema, and hypochondrial pain. Laboratory findings included: urea=112mg/dl, serum creatinine= 4.5 mg/dl, blood pH= 7.47, blood bicarbonate= 12.8 mmol/L, K=7.2 mEq/L. Peritoneal dialysis was started and maintained for 11 days. After 7 weeks, the patient still needed anti-hypertensive drugs and the renal function was still abnormal. Renal biopsy was performed and revealed renal infarction. The result of Doppler ultrasonography revealed absent renal blood flow on the right side. Renal arteriography showed total occlusion of the right renal artery. Results for collagen diseases were negative. A right nephrectomy was performed and the blood pressure was controlled. The child was hospitalized again at 5 years and 8 months old with episodes of absence seizures and abdominal and precordial pain. Anticardiolipin antibody test was positive. The child is now 7 years old, asymptomatic, with negative anticardiolipin antibody, and has been under regular follow-up. COMMENTS: Children with arterial thrombosis should be investigated for a possible association with the antiphospholipid antibody syndrome even in the absence of collagen disease.