994 resultados para intraperitoneal injection


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We determined the anticancer efficacy and internalization mechanism of our polymeric-ceramic nanoparticle system (calcium phosphate nanocores, enclosed in biodegradable polymers chitosan and alginate nanocapsules/nanocarriers [ACSC NCs]) loaded with iron-saturated bovine lactoferrin (Fe-bLf) in a breast cancer xenograft model. ACSC-Fe-bLf NCs with an overall size of 322±27.2 nm were synthesized. In vitro internalization and anticancer efficacy were evaluated in the MDA-MB-231 cells using multicellular tumor spheroids, CyQUANT and MTT assays. These NCs were orally delivered in a breast cancer xenograft mice model, and their internalization, cytotoxicity, biodistribution, and anticancer efficacy were evaluated. Chitosan-coated calcium phosphate Fe-bLf NCs effectively (59%, P≤0.005) internalized in a 1-hour period using clathrin-mediated endocytosis (P≤0.05) and energy-mediated pathways (P≤0.05) for internalization; 3.3 mg/mL of ACSC-Fe-bLf NCs completely disintegrated (~130-fold reduction, P≤0.0005) the tumor spheroids in 72 hours and 96 hours. The IC50 values determined for ACSC-Fe-bLf NCs were 1.69 mg/mL at 10 hours and 1.62 mg/mL after 20 hours. We found that Fe-bLf-NCs effectively (P≤0.05) decreased the tumor size (4.8-fold) compared to the void NCs diet and prevented tumor recurrence when compared to intraperitoneal injection of Taxol and Doxorubicin. Receptor gene expression and micro-RNA analysis confirmed upregulation of low-density lipoprotein receptor and transferrin receptor (liver, intestine, and brain). Several micro-RNAs responsible for iron metabolism upregulated with NCs were identified. Taken together, orally delivered Fe-bLf NCs offer enhanced antitumor activity in breast cancer by internalizing via low-density lipoprotein receptor and transferrin receptor and regulating the micro-RNA expression. These NCs also restored the body iron and calcium levels and increased the hematologic counts.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Methyl mercury (MeHg) is highly neurotoxic, affecting visual function in addition to other central nervous system functions. The effect of mercury intoxication on the amplitude of horizontal cell responses to light was studied in the retina of the fish Hoplias malabaricus. Intracellular responses were recorded from horizontal cells of fish previously intoxicated with MeHg by intraperitoneal injection (IP group) or by trophic exposure (T group). Only one retina per fish was used. The doses of MeHg chloride administered to the IP group were 0.01, 0.05, 0.1, 1.0, 2.0, and 6.0 mg/kg. The amplitudes of the horizontal cell responses were lower than control in individuals exposed to 0.01 (N = 4 retinas), 0.05 (N = 2 retinas) and 0.1 mg/kg (N = 1 retina), whereas no responses were recorded in the 1.0, 2.0, and 6.0 mg/kg groups. T group individuals were fed young specimens of Astyanax sp previously injected with MeHg corresponding to 0.75 (N = 1 retina), 0.075 (N = 8 retinas) or 0.0075 (N = 4 retinas) mg/kg fish body weight. After 14 doses, one every 5 days, the amplitude of the horizontal cell response was higher than control in individuals exposed to 0.075 and 0.0075 mg/kg, and lower in individuals exposed to 0.75 mg/kg. We conclude that intoxication with MeHg affects the electrophysiological response of the horizontal cells in the retina, either reducing or increasing its amplitude compared to control, and that these effects are related to the dose and/or to the mode of administration.

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Scorpaena plumieri venomous fish inflicted severe injuries in humans characterized by systemic effects and cardiovascular abnormalities. Although cardiotoxic and hypotensive effects induced in rats by this venom have been studied, little is known about their effect on bronchial epithelial permeability and airway inflammation in mice. The primary goal of this study was to determine whether the intraplantar or intraperitoneal injection of S. plumieri venom results in systemic response, and whether this event initiates acute lung injure. We found that BALB/c mice developed neutrophilic infiltrates, areas of lung hemorrhage and alveolar macrophage activation within 24 h after injection with S. plumieri venom. These histopathological changes were associated with an early increase in BAL fluid protein and early induction of cytokines, chemokines and matrix metaloproteinases, followed by a later increase in BAL fluid neutrophils. These findings provide clear evidence that the injection of S. plumieri venom in footpad or peritoneal cavity of mice results in venom deposition in the airway and initiates a sustained inflammatory response in the lungs. (C) 2007 Elsevier Ltd. All rights reserved.

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The purpose of the present study was to discover the relative potency of onion, Allium cepa, with respect to its hypoglycaemic and hypolipidaemic effects on the diabetic situation, and the association of these effects with the potential against oxidative stress. Male Wistar rats were divided into four groups. A normal control ( group A), and a non-diabetic group ( group B) were treated daily with 1 ml A. cepa solution (0.4 g A. cepa/rat). Groups C and D were made diabetic by an intraperitoneal injection of streptozotocin (STZ) ( 60 mg/kg body weight) in citrate buffer ( pH 6.3). These animals ( groups C and D) were the STZ diabetic control and STZ diabetic rats with onion intake, respectively. Onion increased the fasting serum high-density lipoprotein levels, and demonstrated alleviation of hyperglycaemia in STZ diabetic rats. The hypoglycaemic and hypolipidaemic actions of A. cepa were associated with antioxidant activity, since onion decreased superoxide dismutase activities while no increased lipid hydroperoxide and lipoperoxide concentrations were observed in diabetic rats treated with A. cepa.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Contamination with cadmium compounds poses high potential risk for the health of populations and for this reason the treatment of their toxic effects should urgently be established. The present study was carried out to determine whether or-tocopherol intake can protect tissues against damage induced by cadmium, and to clarify the contribution of superoxide radicals (O-2(-)) in this process. Cadmium chloride was tested for tissue damage by a single intraperitoneal injection of Cd2+ ions (2 mg Kg(-1)). To determine the potential therapeutic effect of Vitamin E, a group of Cd2+-treated rats received a drinking solution of or-tocopherol (40 mg l(-1)) for 15 days. Cadmium induced increased serum creatinine and total lactate dehydrogenase, reflecting renal and cardiac damage. The increased lipoperoxide and decreased Cu-Zn superoxide dismutase levels indicated the generation of superoxide radicals in cadmium-treated rats. Tocopherol induced increased serum high-density lipoprotein and depressed the toxic effects of Ca2+ alone, since creatinine and lactate dehydrogenase determinations were recovered to the control values. Tocopherol decreased lipoperoxide and led the superoxide dismutase activities to approach those of the control values. We concluded that superoxide radicals are produced as mediators of cadmium toxicity. Tocopherol possesses a significant anti-radical activity and inhibits the cadmium effect on superoxide dismutase activity. Tocopherol also protected tissues from the toxic effects of cadmium by a direct antioxidant action which decreased lipoperoxide formation.

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Objective: the aim of the present study was to evaluate the effect of low-intensity laser therapy on the wound healing process treated with steroid. Background Data: Various biological effects have been associated with low-level laser therapy (LLLT). Materials and Methods: Forty-eight rats were used, and after execution of a wound on the dorsal region of each animal, they were divided into 4 groups (n = 12), receiving the following treatments: G1 (control), wounds and animals received no treatment; G2, wounds were treated with LLLT; G3, animals received an intraperitoneal injection of steroid dosage (2 mg/kg of body weight); G4, animals received steroid and wounds were treated with LLLT. The laser emission device used was a GaAIAs (904 nm), in a contact mode, with 2.75 mW gated with 2.900 Hz during 120 sec (33 J/cm(2)). After the period of 3, 7, and 14 days, the animals were sacrificed and the parts sent to histological processing and dyed using hematoxylin and eosin (HE) and Masson trichromium (MT) techniques. Results: the results have shown that the wounds treated with steroid had a delay in healing, while LLLT accelerated the wound healing process. Also, wounds treated with laser in the animals treated with steroid presented a differentiated healing process with a larger collagen deposition and also a decrease in both the inflamatory infiltrated and the delay on the wound healing process. Conclusion: LLLT accelerated healing, caused by the steroid, acting as a biostimulative coadjutant agent, balancing the undesirable effects of cortisone (in the tissue healing process.

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This experiment was undertaken to study the interaction between level of dietary protein and recombinant human somatotropin (rhGH) administration on performance and body composition of juvenile tambacu (a crossbred Brazilian fish). A total of 72 juvenile tambacu, initially weighing and measuring (mean +/- s.e.m.) 23 +/- 2 g and 9 +/- 0.5 cm, respectively, were randomly divided into 18 groups of 4 fish each. Water temperature was 28 degrees C. Triplicate groups received one of two levels of dietary protein (15 and 30% as fed basis) and one of 3 doses of rhGH (0, 2 and 4 mu g/g) via intraperitoneal injection twice a week for 6 weeks, using a randomized complete block design. Somatotropin was noted to stimulate linear and body weight gain. The higher protein level supported increased growth in weight and length, but there was no interaction between protein level and rhGH dose for either parameter. Protein efficiency ratio and percentage protein deposited showed higher values on diets containing 15% protein. Somatotropin treatment did not significantly affect body composition, but there was a trend towards improved protein retention and reduced carcass lipid. In conclusion, the results of this experiment suggest that rhGH is able to stimulate linear gain in tambacu.

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Objective and design: To investigate the effect of galectin-1 (Gal-1) and -3 (Gal-3) on leukocyte migration and analyze the expression of both galectins in inflammatory cells using a model of rat peritonitis.Material or Subjects: Sprague-Dawley rats (n = 4 per group).Treatment: Peritonitis was induced in animals through intraperitoneal injection of carrageenin (1.5 mg/kg) and rat mesenteries were analyzed at different time points (0, 4, 24 and 48h). For pharmacological treatment, rats received intravenous injection of Gal-1 or -3 (3 mu g/kg) followed by carrageenin.Methods: Western blotting and immunoelectron microscopy analysis. Statistical analysis was performed using ANOVA followed by Bonferroni test.Results: Pharmacological treatment with Gal-1, but not Gal-3, inhibited (similar to 50%) leukocyte recruitment into the peritoneal cavity at 4h time-point. In this early phase, immunogold staining of mesenteries showed a diminished Gal-3 expression in degranulated mast cells and Gal-1 in transmigrated neutrophils (similar to 20% reduction compared to intravascular cells). In the later phases (24 and 48 h), leukocyte turnover was associated with augmented Gal-1 expression in neutrophils and macrophages and Gal-3 in mast cells and macrophages.Conclusions: These results point to a balanced expression of cell-associated-Gal-1/Gal-3 and might impact on the development of new therapeutic strategies for inflammatory diseases.

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The effect of intraperitoneal injection of clonidine (9-72 mu g/kg) on need-free 1.5% NaCl intake and on performance (defined as percent of a complete trial) in the rotarod test, was studied in normovolemic adult male rats. Clonidine (18 and 36 mu g/kg) inhibited the 1.5% NaCl intake in a 2-h test at doses that did not alter the performance in the rotarod test. The dose of 36 mu g/kg did not inhibit 10% sucrose intake. Only the highest dose (72 mu g/kg) of clonidine inhibited the 1.5% NaCl intake and the performance in the rotarod test, and produced signs of sedation. Sedation was determined either by change in posture (immobility or lack of postural tonus) of the animals during the ingestive test or by their performance in the rotarod test. The results suggest that sedation is not a determinant effect on the inhibition of 1.5% NaCl intake induced by clonidine. (C) 1999 Elsevier B.V.

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There are conflicting results on the function of 5-HT in anxiety and depression. To reconcile this evidence, Deakin and Graeff have suggested that the ascending 5-HT pathway that originates in the dorsal raphe nucleus (DRN) and innervates the amygdala and frontal cortex facilitates conditioned fear, while the DRN-periventricular pathway innervating the periventricular and periaqueductal gray matter inhibits inborn fight/flight reactions to impending danger, pain, or asphyxia. To study the role of the DRN 5-HT system in anxiety, we microinjected 8-OH-DPAT into the DRN to inhibit 5 HT release. This treatment impaired inhibitory avoidance (conditioned fear) without affecting one-way escape (unconditioned fear) in the elevated T-maze, a new animal model of anxiety. We also applied three drug treatments that increase 5-HT release from DRN terminals: 1) intra-DRN microinjection of the benzodiazepine inverse agonist FG 4172, 2) intra-DRN microinjection of the excitatory amino acid kainic acid, and 3) intraperitoneal injection of the 5-HT releaser and uptake blocker D-fenfluramine. All treatments enhanced inhibitory avoidance in the T-maze. D-Fenfluramine and intra-DRN kainate also decreased one-way escape. In healthy volunteers, D-fenfluramine and the 5-HT agonist mCPP (mainly 5-HT2C) increased, while the antagonists ritanserin (5-HT2A/(2C)) and SR 46349B (5-HT2A) decreased skin conductance responses to an aversively conditioned stimulus (tone). In addition, D-fenfluramine decreased, whereas ritanserin increased subjective anxiety induced by simulated public speaking, thought to represent unconditioned anxiety. Overall, these results are compatible with the above hypothesis. Deakin and Graeff have suggested that the pathway connecting the median raphe nucleus (MRN) to the dorsal hippocampus promotes resistance to chronic, unavoidable stress. In the present study, we found that 24 h after electrolytic lesion of the rat MRN glandular gastric ulcers occurred, and the immune response to the mitogen concanavalin A was depressed. Seven days after the same lesion, the ulcerogenic effect of restraint was enhanced. Microinjection of 8-OH-DPAT, the nonselective agonist 5-MeO-DMT, or the 5-HT uptake inhibitor zimelidine into the dorsal hippocampus immediately after 2 h of restraint reversed the deficits of open arm exploration in the elevated plus-maze, measured 24 h after restraint. The effect of the two last drugs was antagonized by WAY-100135, a selective 5-HT1A receptor antagonist. These results are compatible with the hypothesis that the MRN-dorsal hippocampus 5-HT system attenuates stress by facilitation of hippocampal 5-HT1A-mediated neurotransmission. Clinical implications of these results are discussed, especially with regard to panic disorder and depression.