997 resultados para chronic toxicity
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transition metals, which are involved in the pathological effects of PM. The objective of this study was to investigate the effects of intranasal administration of ROFA on pulmonary inflammation, pulmonary responsiveness, and excess mucus production in a mouse model of chronic pulmonary allergic inflammation. BALB/c mice received intraperitoneal injections of ovalbumin (OVA) solution (days 1 and 14). OVA challenges were performed on days 22, 24, 26, and 28. After the challenge, mice were intranasally instilled with ROFA. After forty-eight hours, pulmonary responsiveness was performed. Mice were sacrificed, and lungs were removed for morphometric analysis. OVA-exposed mice presented eosinophilia in the bronchovascular space (p < .001), increased pulmonary responsiveness (p < .001), and epithelial remodeling (p = .003). ROFA instillation increased pulmonary responsiveness (p = .004) and decreased the area of ciliated cells in the airway epithelium (p = .006). The combined ROFA instillation and OVA exposure induced a further increase in values of pulmonary responsiveness (p = .043) and a decrease in the number of ciliated cells in the airway epithelium (p = .017). PM exposure results in pulmonary effects that are more intense in mice with chronic allergic pulmonary inflammation.
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The aim of this study was to investigate whether the toxicity of saturated and polyunsaturated fatty acids (PUFA) on RINm5F cells is related to the phosphorylation state of Akt, ERK and PKC delta. The regulation of these kinases was compared in three experimental designs: (a) 4 h-exposure, (b) 4 h-exposure and a subsequent withdrawn of the FA for a 20 h period and (c) 24 h-exposure. Saturated and PUFA were toxic to RINm5F cells even at low concentrations. Also, evidence is provided for a late (i.e. the effect only appeared hours after the treatment) and a persistent regulation (i.e. maintenance of the effect for several hours) of Akt, ERK and PKC delta phosphorylation by the FA. Late activation of PKC delta seems important for palmitate cytotoxicity. Persistent activation of the survival proteins Akt and ERK by stearate, oleate and arachidonate might play an important role to prevent the toxic effect of posterior PKC delta activation. The results shown may explain why a short-period exposure to FA is not enough to induce cytotoxicity in pancreatic beta-cells, since survival pathways are activated. Besides, when this activation is persistent, it may overcome a posterior induction of death pathways. (c) 2008 Elsevier Ltd. All rights reserved.
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Chronic urticaria (daily or almost daily symptoms lasting for more than six weeks) is characterized by wheals and erythema, with or without itching. A few case reports have shown chronic autoimmune urticaria at the beginning of systemic lupus erythematosus (SLE), particularly in adults. However, the prevalence of this manifestation in a lupus paediatric population was not studied. During 27 consecutive years, 5419 patients were followed up at our University Hospital and 271 (5%) had juvenile SLE (American College of Rheumatology criteria). Two of them (0.7%) had chronic and painless autoimmune urticaria as the first manifestation of juvenile SLE, and were reported herein. One case was a five-year old female with continuous widespread urticaria (duration 120 days), antinuclear antibodies (ANA) 1:640 (dense fine speckled pattern) and elevated complement levels. The juvenile SLE diagnosis was established after one year. The other case was a 13-year old female who had chronic widespread urticaria (lasting 45 days), ANA 1:160 (fine speckled pattern) and normal complement levels. The juvenile SLE diagnosis was established after three years. In conclusion, chronic autoimmune urticaria is very rare and may be the first lupus manifestation, particularly associated with the presence of autoantibodies. This study reinforces the importance of a rigorous follow-up in children and adolescents suffering from autoimmune urticaria due to the possibility of connective tissue disorders, such as paediatric lupus. Lupus (2011) 20, 763-766.
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Cutaneous vasculitis may represent a great clinical challenge, even after careful dermatological examination and laboratory assessment. The authors present a case of cutaneous cryoglobulinemic vasculitis associated to chronic hepatitis C virus infection, pointing out the importance of the dermatological examination for diagnostic investigation. They discuss about the importance of defining the etiology and making correct classification for appropriate prognosis and treatment of cutaneous vasculitis.
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Chagas` disease, caused by Trypanosoma cruzi, is an inflammatory disorder leading to chronic Chagas cardiomyopathy (CCC). Only one third of T cruzi-infected individuals progress to CCC while the others are considered asymptomatic (ASY). The human inhibitory kappa B-like gene (KBLINFKBIL1), homologous to the I kappa B family of proteins that regulate the NF kappa B family of transcription factors, is suggested as a putative inhibitor of NFKB. We investigated two functional polymorphisms, -62A/T and -262A/G, in the promoter of IKBL by PCR-RFLP analysis in 169 patients with CCC and 76 ASY. Genotype distributions for both -62A/T and -262A/G differed between the CCC and ASY (X-2 = 7.3; P = 0.025 and X-2 = 6.8; P = 0.03, respectively). Subjects, homozygous for the -62A allele, had three-fold risk of developing CCC compared with those carrying the TT genotype (P = 0.0095; Odds Ratio [OR] = 2.9; [95% CI 1.2-7.3]). Similar trend was observed for the -262A homozygotes (P = 0.005; OR = 2.7 [95% CI 1.3-6.0]. The haplotype -262A -62A was prevalent in patients with CCC (40% versus 24%; OR 2.1 [95% C1 1.4-3.3j; Pc = 0.00 14). The I kappa BL locus itself or another critical gene in this region may confer susceptibility to the development of CCC. (C) 2007 Elsevier Ltd. All rights reserved.
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Ambient particles have been consistently associated with adverse health effects, yielding mainly high cardiorespiratory morbidity and mortality. Diesel engines represent a major source of particles in the urban scenario. We aimed to modify the composition of diesel particles, by means of different extraction procedures, to relate changes in chemical profile to corresponding indicators of respiratory toxicity. Male BALB/c mice were nasally instilled with saline, or with diesel particles, treated or not, and assigned to five groups: saline ( SHAM), intact diesel particles (DEP), and diesel particles previously treated with methanol ( METH), hexane ( HEX), or nitric acid (NA). Elemental composition and organic compounds were analyzed. Twenty-four hours after nasal instillation, respiratory parameters were measured and lung tissue was collected for histological analysis. Static elastance was significantly increased in groups DEP and MET in relation to the other groups. HEX and NA were different from DEP but not significantly different from SHAM and METH groups. The difference between dynamic and static elastance was increased in DEP, METH, and NA treatments; HEX was not statistically different from SHAM. DEP and METH groups presented significantly increased upper airways resistance, while DEP, METH, and NA showed higher peripheral airways resistance values. All groups had a higher total resistance than SHAM. DEP, METH, and NA showed significant increased infiltration of polymorphonuclear cells. In conclusion, diesel particles treated with hexane ( HEX) resulted in a respiratory-system profile very similar to that in SHAM group, indicating that hexane treatment attenuates pulmonary inflammation elicited by diesel particles.
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Fanelli C, Fernandes BH, Machado FG, Okabe C, Malheiros DM, Fujihara CK, Zatz R. Effects of losartan, in monotherapy or in association with hydrochlorothiazide, in chronic nephropathy resulting from losartan treatment during lactation. Am J Physiol Renal Physiol 301: F580-F587, 2011. First published June 8, 2011; doi:10.1152/ajprenal.00042.2011.-We recently standardized a model (L(Lact)) of severe chronic kidney disease based on impaired nephrogenesis by suppression of angiotensin II activity during lactation (Machado FG, Poppi EP, Fanelli C, Malheiros DM, Zatz R, Fujihara CK. Am J Physiol Renal Physiol 294: F1345-F1353, 2008). In this new study of the L(Lact) model, we sought to gain further insight into renal injury mechanisms associated with this model and to verify whether the renoprotection obtained with the association of the angiotensin II receptor blocker losartan (L) and hydrochlorothiazide (H), which arrested renal injury in the remnant kidney model, would provide similar renoprotection. Twenty Munich-Wistar dams, each nursing six pups, were divided into control, untreated, and L(Lact) groups, given losartan (L; 250 mg.kg(-1).day(-1)) until weaning. The male LLact offspring remained untreated until 7 mo of age, when renal functional and structural parameters were studied in 17 of them, used as pretreatment control (L(Lact)Pre), and followed no further. The remaining rats were then divided among groups L(Lact) + V, untreated; L(Lact) + L, given L (50 mg.kg(-1).day(-1)) now as a therapy; L(Lact) + H, given H (6 mg.kg(-1).day(-1)); and L(Lact) + LH, given L and H. All parameters were reassessed 3 mo later in these groups and in age-matched controls. At this time, L(Lact) rats exhibited hypertension, severe albuminuria, glomerular damage, marked interstitial expansion/inflammation, enhanced cell proliferation, myofibroblast infiltration, and creatinine retention. L monotherapy normalized albuminuria and prevented hypertension and the progression of renal injury, inflammation, and myofibroblast infiltration. In contrast to the remnant model, the LH combination promoted only slight additional renoprotection, perhaps because of a limited tendency to retain sodium in L(Lact) rats.
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High voltage electrical stimulation has been recommended as a means of accelerating the wound healing process. The effects of high voltage electrical stimulation were evaluated in the treatment of three volunteers with chronic ulcers of the lower limbs. After fifteen weeks of treatment, a reduction was found in the area of all the ulcers, suggesting that high voltage electric stimulation is an effective therapeutic option for chronic ulcers.
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Objectives: Selective anticancer cell activity for both cell-penetrating and cationic antimicrobial peptides has previously been reported. As crotamine possesses activities similar to both of these, this study investigates crotamine`s anticancer toxicity in vitro and in vivo. Research design and methods: In vitro cancer cell viability was evaluated after treatment with 1 and 5 mu g/ml of crotamine. In vivo crotamine cytotoxic effects in C57Bl/6J mice bearing B16-F10 primary cutaneous melanoma were tested, with two groups each containing 35 mice. The crotamine-treated group received 1 mu g/day of crotamine per animal, subcutaneously which was well tolerated; the untreated group received a placebo. Results: Crotamine at 5 mu g/ml was lethal to B16-F10, Mia PaCa-2 and SK-Mel-28 cells and inoffensive to normal cells. In vivo crotamine treatment over 21 days significantly delayed tumor implantation, inhibited tumor growth and prolonged the lifespan of the mice. Mice in the crotamine-treated group survived at significantly higher rates (n = 30/35) than those in the untreated group (n = 7/35) (significance calculated with the Kaplan-Meier estimator). The average tumor weight in the untreated group was 4.60 g but was only about 0.27 g in the crotamine-treated mice, if detectable. Conclusions: These data warrant further exploration of crotamine as a tumor inhibition compound.
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Objectives The study`s aims were to evaluate the antimycobacterial activity of 13 synthetic neolignan analogues and to perform structure activity relationship analysis (SAR). The cytotoxicity of the compound 2-phenoxy-1-phenylethanone (LS-2, 1) in mammalian cells, such as the acute toxicity in mice, was also evaluated. Methods The extra and intracellular antimycobacterial activity was evaluated on Mycobacterium tuberculosis H37Rv. Cytotoxicity studies were performed using V79 cells, J774 macrophages and rat hepatocytes. Additionally, the in-vivo acute toxicity was tested in mice. The SAR analysis was performed by Principal Component Analysis (PCA). Key findings Among the 13 analogues tested, LS-2 (1) was the most effective, showing promising antimycobacterial activity and very low cytotoxicity in V79 cells and in J774 macrophages, while no toxicity was observed in rat hepatocytes. The selectivity index (SI) of LS-2 (1) was 91 and the calculated LD50 was 1870 mg/kg, highlighting the very low toxicity in mice. SAR analysis showed that the highest electrophilicity and the lowest molar volume are physical-chemical characteristics important for the antimycobacterial activity of the LS-2 (1). Conclusions LS-2 (1) showed promising antimycobacterial activity and very weak cytotoxicity in cell culture, as well as an absence of toxicity in primary culture of hepatocytes. In the acute toxicity study there was an indication of absence of toxicity on murine models, in vivo.
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Chronic exposure to ethanol may results in pathophysiologic changes in cellular function. The present work was designed to investigate the morphology of testis submitted to experimental ethanol ingestion. Experimental animals were divided into two groups. The control group (n = 23) received a solid diet and tap water and the alcoholic group (n = 23) received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 120 days of treatment, all animals were anesthetized, weighed and sacrificed. Testosterone and luteinizing hormone levels in serum were lower in the alcoholic group than in the control group. Histological and ultrastructural alterations were observed in the testicular alcoholic germinative cells like enormous spaces, lipid droplets accumulation, digestive vacuoles, irregular diameter of the seminiferous tubules and interstitial dilated blood vessels. It was concluded that 20% ethanol provokes lesions on the testis germinative epithelium probably inducing gonadal dysfunction. (C) 2008 Elsevier Ltd. All rights reserved.
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Psychostimulants produce a broad range of effects. Adverse effects can exist on a spectrum of severity from minor symptoms to life threatening toxicity. Although regular use or use of high doses increases risk of adverse events, many adverse events requiring emergency intervention may occur even in the naïve user.