Cutaneous hypersensitivity induced in rabbits by extracts of the tick Amblyomma cajennense (Acari : Ixodidae)

The cutaneous hypersensitivity test was used to correlate host resistance to ticks and type of reactions elicited by Amblyomma cajennense (Fabricius, 1787) tick extract in rabbits. Rabbits were divided into 3 groups of 2 animals each: naive, pre-infested and control. Cutaneous hypersensitivity was induced by intradermal inoculation of 25 mug extract in 0.03 rut of phosphate buffered saline (PBS) in rabbit ears. Control rabbits were inoculated with PBS only. The ear thickness was measured with a Mitutoyo(R) device before and 10 min, 1, 2,4,18, 24,48,72 and 96 h post-inoculation (PI). Pre-infested rabbits showed an immediate type reaction within the 1st 10 min PI (60 % increase in ear thickness) and a delayed reaction (18 h) (85 % increase), whereas the naive rabbits showed only the immediate reaction within the 1st 4 h (60 % increase). PBS induced only mild reactions. These results point out the crucial role of the cellular immune response of rabbits in the expression of resistance to A. cajennense.

A critical investigation of the Tanford-Kirkwood scheme by means of Monte Carlo simulations

Monte Carlo simulations are used to assess the adequacy of the Tanford-Kirkwood prescription for electrostatic interactions in macromolecules. Within a continuum dielectric framework, the approach accurately describes salt screening of electrostatic interactions for moderately charged systems consistent with common proteins at physiological conditions. The limitations of the Debye-Huckel theory, which forms the statistical mechanical basis for the Tanford-Kirkwood result, become apparent for highly charged systems. It is shown, both by an analysis of the Debye-Huckel theory and by numerical simulations, that the difference in dielectric permittivity between macromolecule and surrounding solvent does not play a significant role for salt effects if the macromolecule is highly charged. By comparison to experimental data, the continuum dielectric model (combined with either an approximate effective Hamiltonian as in the Tanford-Kirkwood treatment or with exact Monte Carlo simulations) satisfactorily predicts the effects of charge mutation on metal ion binding constants, but only if the macromolecule and solvent are assigned the same or similar permittivities.

Effect of intracerebroventricular injection of ramipril on the drinking response caused by injection of noradrenaline into the third ventricle

We studied the effect of ramipril injected into the third ventricle (3rdV) on the control of water intake induced by injection of noradrenaline into the 3rdV of adult male Holtzman rats (250-300 g) implanted with a chronic stainless steel cannula into the 3rdV. The injection volume was always 1 mu l and was injected over a period of 30-60 sec. Control animals were injected with 0.15 M NaCl. After the injection of isotonic saline (control, 0.15 M NaCl) into the 3rdV, water ingestion was 0.3 +/- 0.1 ml/h. Ramipril (1 mu g/mu l) injected into the 3rdV prior to isotonic saline produced no changes in water ingestion (0.4 +/- 0.2 ml/h). The injection of noradrenaline (40 nmol/mu l) after isotonic saline induced an increase in water intake (3.0 +/- 1.1 ml/h). The prior injection of ramipril decreased this ingestion to 1.8 +/- 0.3 ml/h. These data show that the inhibition of converting enzyme in the brain reduces the water intake induced by catecholaminergic stimulation. We conclude that the brain is able to transform the prodrug ramipril into the active drug ramiprilat.

Clinical evaluation of abutment teeth of removable partial denture by means of the Periotest method

Prosthodontics should be one of the means of establishing conditions for the maintenance of periodontal health. The forces applied to the abutment teeth and their effects are very important considerations in the design and construction of the removable partial dentures. This 6-month follow-up clinical study evaluated the degree of mobility of abutment teeth of distal extension and tooth supported removable partial dentures by using Periotest. Two types of clasp design were selected for evaluation. In cases with unilateral and bilateral distal-extension, a clasp design including a T clasp of Roach retentive arm, a rigid reciprocal arm and a mesial rest were used. For the abutments of tooth-supported removable partial dentures, a second clasp design with a cast circumferential buccal retentive arm, a rigid reciprocal clasp arm and a rest adjacent to the edentulous ridges was selected. A total of 68 abutment teeth was analysed. Periotest values were made at the time of denture placement (control) and at 1, 3 and 6 months after the denture placement. The statistical analysis was performed using Friedman test. All analysis was performed at a 0.05 level of significance. The results revelled that no significant changes in tooth mobility were observed during the 6-months follow-up (P > 0.05). In conclusion, our findings suggest that adequate oral hygiene instructions, careful prosthetic treatment planning and regular recall appointments play an important role in preventing changes in abutment tooth mobility caused by removable partial denture placement.

REDUCTION OF THE AMIDO-BONDED (2-PICOLINAMIDO)PENTAAMMINERUTHENIUM(III) FOLLOWED BY FORMATION OF CIS-(2-PICOLINAMIDE)TETRAAMMINERUTHENIUM(II)

[(NH3)(5)Ru-III(2-NCpy)], obtained from electrochemical oxidation of the Ru(II) complex, undergoes hydrolysis to the amido-bonded [Ru-III(NHC(O)-2-py)]. The electrochemical reduction of this latter complex to Ru(II) is followed by an aquation reaction to form [R(II)(NH3)(5)(OH2)] and free picolinamide and a chelation reaction to form cis-[R(II)-(NH3)(4)(2-pica)] with the displacement of one cis ammonia.

Demographic of short gut syndrome: Increasing demand is not followed by referral of potential candidates for small bowel transplantation

Background. Despite improvements in small bowel transplantation (SBTx), early referral of patients with irreversible intestinal failure (IF) remains a major obstacle. In this study we evaluated the demand for SBTx among seven surgical pediatric centers located at least 200 km from our center.Methods. From 1997 to 2001, 640 patients have been treated for neonatal diseases, including 248 who underwent a minor or major intestinal resection. Twenty-four patients with major resections presented with short gut syndrome, requiring total parenteral nutrition (TPN). The greatest demand was in postsurgical neonates with necrotizing enterocolitis, gastroschiesis, onphalocoeles, or midgut volvulus, and in three adults with postradiotherapy arteritis (n = 2) and mesenteric vein thromboses (n = 1). The median length of residual bowel after resection was 20 to 30 cm, without an ileocecal valve. Four patients were referred for SBTx evaluation; three died while awaiting a donor; 20 were not referred, among whom 14 died of TPN complications.Results. Approximately 62 children per year require nutritional support for IF, most of whom develop complications related to TPN. Because many patients who are TPN-dependent develop complications, we believe that early referral would reduce mortality.Conclusions. Greater medical awareness about the feasibility of SBTx procedures and earlier referral may improve results and quality of life after transplant.

Three- phase four-wire circuits interpretation by means of different power theories

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Controlled fluorination of a-C:F:H films by PECVD of ethylene-hexafluorobenzene mixtures

Highly fluorinated plasma polymers are chemically inert,acid resistant and have low friction coefficients, thereby being useful in chemical laboratories and for tribological applications. Here we report the plasma polymerization of ethylene-hexafluorobenzene mixtures by PECVD. The principal parameter of interest is the proportion of C(6)F(6) in the feed, R(F). Films were analyzed using near-normal and grazing-angle Infrared Reflection Absorption Spectroscopy (IRRAS), the latter being particularly useful for detecting modes not usually observed at near-normal incidence. The presence of CH and CF(x) (x=1 to 2) groups was thus confirmed in films deposited with R(F)>= 40%. Depending on R(F) IRRAS also revealed the presence of -CH(x) (x=1 to 3) -C=C, -C=O and phenyl rings. Deconvolution of C is spectra obtained by X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of CH, CF and CF(2) groups in films deposited with R(F)>= 40%. Atomic ratios of F:C calculated from the XPS spectral data show that the degree of fluorination rises with increasing RF Some unbound fluorine is present in the films. Post-deposition reactions account for the presence of oxygen (similar to 5%) in the films. Surface energies, determined from contact angle measurements, fall with increasing R(F). (C) 2008 Elsevier B.V. All rights reserved.

Preparation of CuO/SiO2 and photocatalytic activity by degradation of methylene blue

A photocatalyst based on CuO/SiO2 was prepared, and evaluated for the degradation of methylene blue in aqueous medium. The photocatalyst was obtained by calcination method of copper salt, in the presence of silica. The characterization by XRD, FTIR, and TPR techniques confirmed the formation of CuO as active phase. SEM studies showed CuO deposited on the surface of SiO2. By ESI-MS, it was demonstrated that the degradation of methylene blue occurs through successive hydroxylations. Photodegradation assays showed that CuO/SiO2 was efficient for degradation, and that the material worked better in the presence of UV light.

Protease activity in extracellular products secreted in vitro by trophozoites of Giardia duodenalis

There are evidences that Giardia trophozoites contain and/or release proteolytic enzymes that may be implicated in pathogenesis of giardiasis. This report describes a preliminary characterization of the proteolytic activity in excretory/secretory (E/S) products of Giardia duodenalis trophozoites of an axenic Brazilian strain (BTU-11) and the reference strain Portland 1 (P1). The protease activity of E/S products in conditioned medium by trophozoites of each strain was analyzed using substrate (gelatin and collagen) impregnated SDS-PAGE and hemoglobin assay. The protease characterization was based on inhibition assays including synthetic inhibitors. Proteolytic products were detected in the conditioned medium by trophozoites of both assayed strains. In the gels containing copolymerized gelatin and collagen, E/S products promoted degradation of the substrates and the most evident proteolysis zones were distributed in the migration regions of 77 to 18 kDa and 145 to 18 kDa, respectively, in the patterns of gelatinolytic and collagenolytic activities. Degradation of hemoglobin was also observed, and the pattern of hydrolysis was similar in both E/S products assayed. Inhibition assays showed that the main proteolytic activity in both E/S products is due to cysteine proteases although the presence of serine proteases was also indicated, mainly in the hydrolysis of hemoglobin.