Flow injection analysis of paracetamol using a biomimetic sensor as a sensitive and selective amperometric detector

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

Direct determination of calcium in milk by atomic absorption spectrometry using flow-injection analysis

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

Sequential injection analysis system with spectrophotometric detection for determination of norfloxacin and ciprofloxacin in pharmaceutical formulations

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

Flow-injection spectrophotometric determination of tetracycline and doxycycline in pharmaceutical formulations using chloramine-T as oxidizing agent

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

A pH optode based on thymol blue: application to determination of CO2 using flow injection analysis system

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

Effect of injection of L-NAME on drinking response

The drinking behavior responses to centrally administered NG-nitro-L-arginine methyl ester (L-NAME; 10, 20 or 40 µg/µl), an inhibitor of nitric oxide synthase, were studied in satiated rats, with cannulae stereotaxically implanted into the lateral ventricle (LV) and subfornical organ (SFO). Water intake increased in all animals after angiotensin II (ANG II) injection into the LV, with values of 14.2 ± 1.4 ml/h. After injection of L-NAME at doses of 10, 20 or 40 µg/µl into the SFO before injection of ANG II (12 ng/µl) into the LV, water intake decreased progressively and reached basal levels after treatment with 0.15 M NaCl and with the highest dose of L-NAME (i.e., 40 µg). The water intake obtained after 40 µg/µl L-NAME was 0.8 ± 0.01 ml/h. Also, the injection of L-NAME, 10, 20 or 40 µg/µl, into the LV progressively reduced the water intake induced by hypertonic saline, with values of 5.3 ± 0.8, 3.2 ± 0.8 and 0.7 ± 0.01 ml/h, respectively. These results indicate that nitric oxide is involved in the regulation of drinking behavior induced by centrally administered ANG II and cellular dehydration and that the nitric oxide of the SFO plays an important role in this regulation.

Role of nitric oxide of the median preoptic nucleus (MnPO) in the alterations of salivary flow, arterial pressure and heart rate induced by injection of pilocarpine into the MnPO and intraperitoneally

We investigated the effect of L-NAME, a nitric oxide (NO) inhibitor and sodium nitroprusside (SNP), an NO-donating agent, on pilocarpine-induced alterations in salivary flow, mean arterial blood pressure (MAP) and heart rate (HR) in rats. Male Holtzman rats (250-300 g) were implanted with a stainless steel cannula directly into the median preoptic nucleus (MnPO). Pilocarpine (10, 20, 40, 80, 160 µg) injected into the MnPO induced an increase in salivary secretion (P<0.01). Pilocarpine (1, 2, 4, 8, 16 mg/kg) ip also increased salivary secretion (P<0.01). Injection of L-NAME (40 µg) into the MnPO prior to pilocarpine (10, 20, 40, 80, 160 µg) injected into the MnPO or ip (1, 2, 4, 8, 16 mg/kg) increased salivary secretion (P<0.01). SNP (30 µg) injected into the MnPO or ip prior to pilocarpine attenuated salivary secretion (P<0.01). Pilocarpine (40 µg) injection into the MnPO increased MAP and decreased HR (P<0.01). Pilocarpine (4 mg/kg body weight) ip produced a decrease in MAP and an increase in HR (P<0.01). Injection of L-NAME (40 µg) into the MnPO prior to pilocarpine potentiated the increase in MAP and reduced HR (P<0.01). SNP (30 µg) injected into the MnPO prior to pilocarpine attenuated (100%) the effect of pilocarpine on MAP, with no effect on HR. Administration of L-NAME (40 µg) into the MnPO potentiated the effect of pilocarpine injected ip. SNP (30 µg) injected into the MnPO attenuated the effect of ip pilocarpine on MAP and HR. The present study suggests that in the rat MnPO 1) NO is important for the effects of pilocarpine on salivary flow, and 2) pilocarpine interferes with blood pressure and HR (side effects of pilocarpine), that is attenuated by NO.

Dimethyl sulfoxide effects on the febrile response to lipopolysaccharide injection in rabbits

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of intraperitoneal injection of phenol, glycerin and acetic acid on neoplastic ascitis in guinea pigs

OBJETIVO: Investigar a ação hìstolítica de uma solução composta de fenol, glicerina e ácido acético na ascite neoplásica em cobaias. MÉTODOS: Foram utilizadas 32 cobaias, distribuídas por sorteio, em grupos experimentais e controles e estudados os efeitos da injeção peritonial da solução teste. Nos grupos controles empregou-se solução fisiológica. Foram estudadas alterações bioquímicas, anatomopatológicas (coração, pulmões, rins, baço e serosa peritonial), com 24 horas e 4 semanas de evolução. RESULTADOS: Verificou-se que a solução E quando instilada na cavidade peritonial não provocou nenhuma alteração clinica, histologica ou laboratorial nestes animais, quando comparados com o grupo controle. CONCLUSÃO: Frente aos resultados obtidos, consideramos interessante estudar os efeitos da solução proposta em casos de ascite neoplásica experimental em animais, com posterior estudo em seres humanos.

Histologic study of use of microfibrillar collagen hemostat in rat dental sockets

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

INJECTION OF RAMIPRIL INTO THE LATERAL VENTRICLE INTERFERES WITH THE DRINKING RESPONSE INDUCED BY PHARMACOLOGICAL AND NATURAL THIRST STIMULI

We investigated the effects of ramipril, an angiotensin I-converting enzyme (ACE) inhibitor, on water intake by male Holtzman rats (250-300 g) with cannulae implanted into the lateral ventricle. Intracerebroventricular (icv) injection of ramipril (1 mu g/mu l) significantly reduced drinking in response to subcutaneous (sc) injection of isoprenaline (100 mu g/kg) from 8.49 +/- 0.69 to 2.96 +/- 0.36 ml/2 h, polyethyleneglycol (PEG) (30% w/v, 10 ml/kg) from 9.51 +/- 2.20 to 1.6 +/- 0.34 ml/2 h or water deprivation for 24 h from 12.61 +/- 0.83 to 5.10 +/- 1.37 ml/2 h. Ramipril had no effect on water intake induced by cellular dehydration produced by sc injection of hypertonic saline (2 M NaCl). These results are consistent with the hypothesis that ramipril acts as an ACE-blocking agent in the brain. The possibility that ramipril is transformed to ramiprilat, the active drug, by the brain is suggested.

Opposite effects of bFGF and TGF-beta on collagen metabolism by human periodontal ligament fibroblasts

This study evaluated the effects of bFGF and TGF-beta, individually and combined, on cell proliferation and collagen metabolism. Primary human periodontal ligament cells were stimulated with two concentrations (I and 10 ng/ml) of each growth factor, both individually and combined. Proliferation was determined by a commercial biochemical assay. Real time RT-PCR determined gene expression of NMP-1 and -2, collagen types I and III, TIMP-1, -2 and -3. Autocrine effects on synthesis of bFGF and TGF-beta were evaluated by ELISA. Only TGF-beta, either isolated or associated with bFGF, significantly increased cell proliferation. TGF-beta had anabolic effects, increasing expression of type I and III collagen as well as of TIMPs, whereas bFGF had opposite effects. When bFGF and TGF-beta were associated, the anabolic effects prevailed. Synthesis of TGF-beta was induced only by the association of lower concentrations of the growth factors, whereas there was a dose-dependent production of bFGF. It is concluded that bFGF had a predominantly catabolic effect, and TGF-beta exerted an anabolic effect on hPDL cells. (c) 2007 Elsevier Ltd. All rights reserved.

Metallic powder injection molding using low pressure

The demand by high performance materials that have to support severe service conditions at a reasonable cost has been forcing the powder metallurgy to improve constantly. The most recent and more important innovation in the area is the process of powder injection.Powder injection molding (PIM) is a technology capable of producing a new range of components from powders. This advanced technology overcomes the existent limitations in the forming of products with complex geometry. The process presents countless variations which are used in the industry today. Invariably, it consists of mixing the powders and a thermo-plastic binder, injecting the mass in the mold in the wanted form, debinding, sintering and making optional secondary operations, as for example, machinery.The purpose of this work is to review the metal injection molding techniques and apply the low pressure injection molding process to family of parts using metallic powder with 10 mum particle size. This work also comments the design and construction of a low pressure injection machine and injection molds. (C) 2001 Elsevier B.V. B.V. All rights reserved.

A histologic assessment of the influence of low-intensity laser therapy on wound healing in steroid-treated animals

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.

Biocompatibility studies of anionic collagen membranes with different degree of glutaraldehyde cross-linking

The work describes the biocompatibility and biodegradation studies of anionic collagen membranes casted form collagen gels collagen, that were selective hydrolyzed at the carboxyamide groups, as a function of the degree of cross-links induced by glutaraldehyde. Independently from the degree of cross-links, all membranes studied were characterized by a similar inflammatory response, inversely dependent on glutaraldehyde reaction time, that decreased from the time of the implant. Cell alterations, mineralization or contact necrosis were not observed in any of the membranes studied. Rates for membrane tissue biodegradation were directly related to glutaraldehyde reaction time, and ranged from 30 to periods longer than 60 days, associated with good biocompatibility. Although other properties must be considered, their use in the treatment of periodontal diseases, the biological behavior observed with the 8 h GA cross-linked membrane suggests that, anionic collagen membrane described in this work may be of potential use, not only in association with guided tissue regeneration technique for periodontal tissue reconstruction, but also in other collagen biomaterial applications where controlled biodegradability is required. (C) 1998 Published by Elsevier B.V. Ltd. All rights reserved.