Efeitos de diferentes doses de tenoxicam sobre a medula espinhal e as meninges. Estudo experimental em caes

Background and Objectives. The analgesic actions of nonsteroidal anti-inflammatory drugs (NSAID) result from the inhibition of the peripheral synthesis of prostaglandins. In spite of the emphasis on the peripheral action, several studies have shown the potential central action of such drugs. In rats, NSAID doses insufficient to block pain when systemically administered were effective when intrathecally injected. This effect could be mediated by interaction with descending serotoninergic ways together with neurotransmission modulation of glycine or N-methyl-D-aspartate receptors. Our goal was to study the effect of different tenoxican doses in the histology of dogs spinal cord and meninges. Methods. Thirty two dogs (7 to 17 kg) were randomly distributed in four groups: G1 - Control with distilled water (DW); G2 - 2 mg tenoxican diluted in DW; G3 - 4 mg tenoxican diluted in DW; G4 - 10 mg tenoxican diluted in DW in a constant volume of 1 ml. Anesthesia was induced with etomidate and fentanyl and dural puncture was performed with a 25G spinal needle in interspace L6-7. Animals were observed for 72 hours and subsequently euthanized by electrocution. Lumbar and sacral spinal cord segments were removed for further histologic examination. Results. All animals were clinically normal during the observation period and there has been no histologic alteration of the nervous system and meninges. Conclusions. In our experimental model intrathecal tenoxican doses up to 10 mg have not triggered nervous tissue or meningeal injuries in dogs.

Comparacao da recuperacao de anestesia venosa com propofol e anestesia inalatoria com sevoflurano para laparoscopia ginecologica

Backgrounds and Objectives: Both continuous venous anesthesia with propofol and inhalational anesthesia with sevoflurane propitiate fast arousal with few side effects. The aim of this study was to compare the arousal and post anesthestic recovery times in patients submitted to these two agents. Methods: Forty three patient aged 18 to 50 years, physical status I or II, submitted to gynecological laparoscopy were distributed in two groups: G1 - propofol in continuous infusion of 115 μg.kg -1.min -1 and G2 sevoflurane. All the patients were pre-medicated with 7.5 mg midazolam, sufentanil 0.5 μg.kg -1, propofol 2 mg.kg -1, atracurium 0.5 mg.kg -1, N 2O in 50% of oxygen in a no-rebreathing system. The depth of the anesthesia and arousal time were assessed by the Bispectral index (BIS). The time between end of anesthesia and eye opening, time for command response and time for orientation were also evaluated. Results: The times recorded in minutes were: G1 - eye opening 8.2 ± 2.9, command response 8.6 ± 3.1, orientation 9.8 ± 3.4, recovery 31.6 ± 3.8; G2 - eye opening 4.5 ± 3, command response 4.9 ± 3.4, orientation 6.2 ± 3.4, recovery 66 ± 8. Except the recovery time, all the values were larger in G1. Conclusions: Both intravenous propofol or inhalational sevoflurane were considered excellent anesthetic techniques as to recovery time and recovery room discharge. Sevoflurane provided an earlier arousal with a longer recovery room stay as compared to propofol.

Tracheobronchial consequences of the use of heat and moisture exchangers in dogs

Purpose: To determine the effect of heat and moisture exchange (HME) on the tracheobronchial tree (TBT) using a unidirectional anesthesic circuit with or without CO2 absorber and high or low fresh gas flow (FGF), in dogs. Methods: Thirty-two dogs were randomly allocated to four groups: G1 (n = 8) valvular circuit without CO2 absorber and high FGF (5 L·min-1); G2 (n = 8) as G1 with HME; G3 (n = 8) circuit with CO2 absorber with a low FGF (1 L·min-1); G4 (n = 8) as G3 with HME. Anesthesia was induced and maintained with pentobarbital. Tympanic temperature (TT), inhaled gas temperature (IGT), relative (RH) and absolute humidity (AH) of inhaled gas were measured at 15 (control), 60, 120 and 180 min of controlled ventilation. Dogs were euthanized and biopsies in the areas of TBT were performed by scanning electron microscopy. Results: The G2 and G4 groups showed the highest AH (>20 mgH2O·L-1) and G1 the lowest (< 10 mgH2O·L-1) and G3 was intermediate (<20 mgH2O·L-1) (P < 0.01). There was no difference of TT and IGT among groups. Alterations of the mucociliary system were greatest in G1, least in G2 and G4, and intermediate in G3. Conclusion: In dogs, introduction of HME to a unidirectional anesthetic circuit with/without CO2 absorber and high or low FGF preserved humidity of inspired gases. HME attenuated but did not prevent alterations of the mucociliary system of the TBT.

Titulacao do sevoflurano utilizando o indice bispectral em anestesia pediatrica. Influencia da medicacao pre-anestesica no tempo de despertar e no consumo de anestesico inalatorio

Background and Objectives - Sevoflurane is an inhalational anesthetic drug with low blood/gas solubility providing fast anesthesia induction and emergence. Its ability to maintain cardiovascular stability makes it ideal for pediatric anesthesia. The aim of this study was to evaluate hemodynamic stability, consumption of inhalational anesthetics and emergence time in children with and without premedication (midazolam or clonidine) anesthetized with sevoflurane titrated according to BIS monitoring. Methods - Participated in this study 30 patients aged 2 to 12 years, physical status ASA I, undergoing elective surgeries who were divided into 3 groups: G1 - without premedication, G2 - 0.5 mg.kg-1 oral midazolam, G3 - 4 μg.kg-1 oral clonidine 60 minutes before surgery. All patients received 30 μg.kg-1 alfentanil, 3 mg.kg-1 propofol, 0.5 mg.kg-1 atracurium, sevoflurane in different concentrations monitored by BIS (values close to 60) and N2O in a non rebreathing system. Systolic and diastolic blood pressure, heart rate, expired sevoflurane concentration (EC), sevoflurane consumption (ml.min-1) and emergence time were evaluated. Emergence time was defined as time elapsed between the end of anesthesia and patients' spontaneous movements trying to extubate themselves, crying and opening eyes and mouth. Results - There were no differences among groups as to systolic and diastolic blood pressure, EC, sevoflurane consumption and emergence time. Heart rate was lower in G3 group. Conclusions - Sevoflurane has provided hemodynamic stability. Premedication with clonidine and midazolam did not influence emergence time, inhaled anesthetic consumption or maintenance of anesthesia with sevoflurane. Anesthesia duration has also not influenced emergence time. Hypnosis monitoring was important for balancing anesthetic levels and this might have been responsible for the similarity of emergence times for all studied groups.

Efeitos do alopurinol em rins isquemicos de caes anestesiados com pentobarbital sodico

Background and Objectives - Allopurinol is a drug which inhibits the formation of noxious renal free radicals. The aim of this study was to evaluate the protecting renal effects of allopurinol in ischemic kidneys of dogs. Methods - Sixteen dogs were anesthetized with sodium pentobarbital and submitted to extracellular volume expansion (1.4 ml.kg-1.min-1), to mechanic ventilation with air, to right nephrectomy and to left renal artery clamping. Changes which might occur in renal morphology and function after 30 min of total ischemia and posterior reperfusion were studied in Group 1 (G1), in addition to the action of allopurinol (50 mg.kg-1) on those kidneys, when administered 24 h before the experiment and 1 h before the ischemic procedure in Group 2 (G2). The following parameters: heart rate, inferior vena cava pressure, mean blood pressure, PAH clearance (PAH(c)), renal blood flow (RBF), renal vascular resistance (RVR), creatinine clearance (Cr(c)), filtration fraction, urine output, plasma and urine osmolality, osmolar clearance, free water, sodium and potassium clearance, urine and fractional sodium and potassium excretion, hematocrit, rectal temperature, and left kidney histology were evaluated in four moments: M1 control, and M2, M3, M4 obtained immediately, 15 and 30 min after unclamping of the left renal artery. In G2, M1, M2, M3 and M4 were obtained 45, 90, 105, and 120 min after the second allopurinol dose. Results - Both groups showed the highest values for PAH(c), RBF, and Cr(c), and the lowest values for RVR in M1. Animals were tachycardiac since the beginning of the experiment both in G1 and in G2. The other parameters were not changed. Left kidney histological evaluation showed alterations compatible with acute tubular necrosis in both experimental groups. Conclusions - Alterations found in renal hemodynamics were compatible with the release of vasoconstrictor substances due to renal ischemia. Allopurinol was not effective in preventing renal alterations caused by ischemia and reperfusion.

Evaluation of intraocular and partial CO2 pressure in dogs anesthetized with propofol

The effects of propofol on intraocular pressure (IOP) and end tidal CO2 (ETCO2) were studied because an elevation in the latter may alter IOP. Twenty dogs were divided into two groups (G1 and G2). G1 dogs were induced with 10 mg/kg (IV) of propofol followed by a 0.4 mg/kg/min continuous infusion of the same agent diluted in a 0.2% dextrose solution for 1 h. G(CAPS) 2 dogs served as the control group, where only dextrose solution was administered, under the same time intervals as in G1. Applanation tonometry (Tono-Pen) was used to determine IOP and ETCO2 as a method to determine partial CO2 pressure. Measurements were taken every 15 min for 1 h, with M1 occurring immediately before IV administration. IOP and ETCO2 were not statistically significant in either groups. Based on the results, it may be concluded that propofol does not alter IOP and ETCO2.

Análise das vantagens de duas técnicas anestésicas - Venosa e inalatória - Para colecistectomia por videolaparoscopia

Background and Objectives - It is essential to reduce health care costs without impairing the quality of care. Propofol is associated to faster recovery and it is known that post-anesthesia care unit (PACU) costs are high. The aim of this study was to evaluate the advantages of two anesthesia regimens - propofol continuous infusion or isoflurane - taking into account the cost of both techniques on PACU stay. Methods - Forty seven patients, physical status ASA I, II and III, undergoing laparoscopic cholecystectomy were divided into 2 groups according to the anesthetic agent: G1, conventional propofol continuous infusion (100-150 μg.kg-1.min-1) and G2, isoflurane. All patients were induced with sufentanil (1 μg.kg-1) and propofol (2 mg.kg-1) and were kept in a re-inhalation circuit (2 L.min-1 of fresh gas flow) with 50% N2O in O2, sufentanil (0.01 μg.kg-1.min-1) and atracurium (0.5 mg.kg-1), or pancuronium (0.1 mg.kg-1) for asthma patients. All patients received atropine and neostigmine at the end of the surgery. Prophylactic ondansetron, dipyrone and tenoxican were administered and, when necessary, tramadol and N-butylscopolamine. Costs of anesthetic drugs (COST), total PACU stay (t-PACU), and PACU stay after extubation (t-EXT) were computed for both groups. Results - Costs were significantly lower in the isoflurane group but t-PACU was 26 minutes longer and t-EXT G1<G2, although not statistically significant, t-PACU x t-EXT and t-EXT x COST were significant for G1 only. Therefore, in G1, t-PACU was a function of propofol doses. Conclusions - We concluded that the use of isoflurane as anesthesia maintenance agent for laparoscopic cholecystectomy showed lower drug costs as compared to propofol. However, isoflurane group patients stayed longer in PACU as compared to propofol continuous infusion group.

Chromosome damage induced by 5-azacytidine under the influence of caffeine or cytosine arabinoside in CHO-K1 (wild-type) and XRS-5 (mutant) cell lines

5-azacytidine (5-azaC) treatment combined with cytosine arabinoside (ara-C) or caffeine were performed in vitro in Chinese hamster cells, CHO-K1 (wild-type) and xrs-5 (mutant) cell lines, in order to compare the cell response to the induction of chromosomal aberrations. Exponentially growing cells were treated with 5-azaC (4-16 uM) for 1 h, the cells were washed and incubated for 7 h, and 500 uM caffeine or 5 uM ara-C were added to the cultures for the last 2 h. In both cell lines, 5-azaC induced a significantly increase (P<0.01) in the frequencies of aberrations; in the combined treatments (5-azaC + Ara-C), a significant reduction (P<0.05) was observed for the aberrations which were randomly distributed. Caffeine had no influence at the same conditions. 5-azaC induced-DNA lesions were probably processed at S/G2 phase in a common pathway in both cell lines, but alternatively, 5-azaC may cause xrs-5 cells to revert to the wild-type.

Estudo comparativo das complicações terapêuticas no Lúpus Eritematoso Sistêmico e nas glomerulopatias idiopáticas.

PURPOSE: To evaluate the therapeutic complications due to the use of immunosupressors in patients with nephropathy. METHODS: 76 patients who had used steroids and cyclophosphamide were retrospectively studied. The cases were divided into three groups: G1= 15 patients with Systemic Lupus Erythematosus without renal lesion; G2= 33 patients with lupus nephritis and G3= 28 patients with nephrotic syndrome owing to idiopathic glomerulopathy. RESULTS: There were no differences related to time of follow up (G1= 42.4 +/- 51, G2= 52.3 +/- 51, G3= 41.8 +/- 47.8 months), total used dosage of steroids (G1= 20, G2= 28, G3= 16 grams) and time of drug use (G1= 20, G2= 26, G3= 14.5 months). About cyclophosphamide use, there was no difference in the percentage of patients who used it (13% in G1, 51% in G2, 28% in G3), but the patients from G1 received lower total dosage than those from G2 (p<0.05). Cushingoid appearance, epigastric distress, psychiatric disorders, diabetes mellitus and ocular alterations occurred in all the three groups, with no statistically significant differences. The infections complications, those considered more severe clinically, were more frequent in G2 (G1= 6%, G2= 15%, G3= 0% - p<0.05), the same occurring with the deaths (7% in G1, 30% in G2, 0% in G3 - p<0.05). CONCLUSION: In patients with lupus nephritis there were more infections complications owing to prolonged immunosuppresion what may indicate a severity marker of this type of lesion.

Avaliações bioquímicas séricas e hepáticas do extrato de yacon (Polymnia sonchifolia) Poepp. & Endl.

Yacon is a medicinal plant, the tuberous roots of which have been thought to contain a large amount of fructan (oligosaccharides). Purpose - The aim of paper was to study the effect of aqueous extracts of yacon on biochemical parameters of clinical importance in rats. The animals (male, wistar, weighing approximately 300g) were divided in 3 groups: G1(n=8)= water control; G2(n=8)= aqueous extract of roots (0,17g/100g/day); G3(n=8)= aqueous extract of leaves (25mg/100g/day). The serum samples were obtained after 30 days, and the biochemical parameters were measured. The livers were removed and homogenized in 0,01M phosphate buffer pH 7,0 and then the supernatant fractions were used for enzyme assay. Significantly increased serum glucose was observed in G2 (206,72±91,27 mg/dL). The groups G2 and G3 rats had higher (p<0,05) urea concentration, while creatinin level decreased (p<0,05). The serum albumin concentration showed a tendency to remain in G2 (2,44±0,45 g/dL) and G3 (2,84±0,50 g/dL). Aqueous extracts administration markedly decreased (p<0,05) the activities of ALT in the liver and greatly increased these enzymatic activities in blood. The serum alkaline phosphatase activity increased (p<0,05) in rats receiving the aqueous extract of root (192,75±20,95 U/dL), while aqueous extract of leaves reduced it (129,57±19,93 U/dL). The results indicated that the extract of yacon promoted changes of the biochemical parameters.

Avaliação bioquímica do extrato etanólico de própolis em ratos

Propolis is a natural product collected by honey bees containing, among other biochemical constituents, a variety of flavonoids. Propolis is a folk medicinal employed for treating various diseases. It is alleged to exhibit a broad spectrum of bioactivities. The aim of this study was to evaluate the effect of ethanolic extract of propolis (EEP) of species Plebeia droryana and Scaptotrigonea bipunctata through biochemical parameters. Rats were divided into 4 groups: (G1) untreated; (G2) ethanol treated; (G3) treated EEP of Plebeia droryana; (G4) treated of Scaptotrigonea bipunctata. The EEP (100 mg/kg b. w., daily) was administered orally to the animals, for 30 days. Treatment with EEP for two species showed reduction (p<0,05) in serum alanine aminotransferase, aspartato aminotransferase and alkaline phosphatase activity, compared to control ethanol values. The administration of EEP lowered significantly the serum levels of cholesterol (G3= 48,83±5,7 mg/dL; G4=56,91±6,5 mg/dL) and triacylglycerol (G3=45,17±4,16 mg/dL; G4=46,74± 3,90 mg/dL). The serum concentration of albumin (G3=4,16±0,6 g/dL; G4= 3,61±0,36 g/dL) increased (p<0,05) after the administration of EEP, however, it did not affect total protein and glucose concentration. The data suggest that EEP of two species caused alterations of the biochemical parameters.

Evaluation of marginal microleakage in Class II cavities: Effect of microhybrid, flowable, and compactable resins

Objective: The goal of the present study was to evaluate the microleakage on the cementum/dentin and enamel surfaces in Class II restorations, using different kinds of resin composite (microhybrid, flowable, and compactable). Method and materials: Forty human caries-free molars were extracted and selected. Eighty Class II standardized cavities were made in the cervical wall at the cementoenamel junction (CEJ) and at the mesial and distal surfaces. The teeth were divided into four groups: G1 - adhesive system + microhybrid resin composite Z100; G2 - adhesive system + compactable resin composite Prodigy Condensable; G3 - adhesive system + flowable resin composite Revolution + Z100 resin composite; G4 - adhesive system + Revolution fluid resin + compactable resin composite Prodigy Condensable. The adhesive system used in this study was Scotchbond Multi-Purpose Plus. The specimens were thermocycled in baths of 5°C and 55°C for 1,000 cycles and immersed in 50% silver nitrate solution. The specimens then were sectioned and evaluated on degree of dye penetration. Results: The results were evaluated using the nonparametric Kruskall-Wallis test, which showed a statistically significant difference between groups G1 and G4, G2 and G4, and G3 and G4. Conclusions: None of the materials was able to eliminate the marginal microleakage at the cervical wall; the application of a low-viscosity resin composite combined with a compactable resin composite significantly decreased the microleakage.

In vitro penetration of bleaching agents into the pulp chamber

Aim: To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures. Methodology: Bovine lateral incisors were sectioned 3 mm apical to the cemento-enamel junction and the coronal pulpal tissue was removed. Teeth were divided into six groups (n = 10): G1, G2 and G3 were not submitted to any restorative procedure, while G4, G5 and G6 were submitted to Class V preparations and restored with composite resin. Acetate buffer was placed in the pulp chamber and treatment agents were applied for 60 min at 37°C as follows: G1 and G4, immersion into distilled water; G2 and G5, 10% carbamide peroxide (CP) exposure; G3 and G6, 35% CP bleaching. The buffer solution was removed and transferred to a glass tube where leuco crystal violet and horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined spectrophotometrically at 596 nm. A standard curve made with known amounts of hydrogen peroxide was used to convert the optical density values of the coloured samples into microgram equivalents of hydrogen peroxide. Data were submitted to ANOVA and Tukey's test (5%). Results: Amounts of hydrogen peroxide found in the pulp chamber of G2 and G5 specimens (0.1833 ± 0.2003 μg) were significantly lower (P = 0.001) when compared to G3 and G6 specimens (0.4604 ± 0.3981 μg). Restored teeth held significantly higher (P = 0.001) hydrogen peroxide concentrations in the pulp chamber than intact teeth. Conclusion: Higher concentrations of the bleaching agent produced higher levels of hydrogen peroxide in the pulp chamber, especially in restored teeth.

Effect of ceramic surface treatment on the microtensile bond strength between a resin cement and an alumina-based ceramic

Purpose: The objective of this study was to test the following hypothesis: the silica coating on ceramic surface increases the bond strength of resin cement to a ceramic. Materials and Methods: In-Ceram Alumina blocks were made and the ceramic surface was treated: G1 - sandblasting with 110-μm aluminum oxide particles; G2 - Rocatec System: tribochemicai silica coating (Rocatec-Pre powder + Rocatec-Plus powder + Rocatec-Sil); G3 - CoJet System: silica coating (CoJet-Sand) + ESPE-Sil. The ceramic blocks were cemented to composite blocks with Panavia F resin cement (under a load of 750 g/1 min). The cemented blocks were stored in distilled water at 37°C for 7 days and sectioned along the x and y axes with a diamond disk. Samples with an adhesive area of ca 0.8 mm 2 (n = 45) were obtained. The samples were attached to an adapted device for the microtensile test, which was performed in a universal testing machine (EMIC) at a crosshead speed of 1 mm/min. Results: The obtained results were submitted to ANOVA and Tukey's test. Mean values of tensile strength (MPa) and standard deviation values were: (G1) 16.8 ± 3.2; (G2) 30.6 ± 4.5; (G3) 33.0 ± 5.0. G2 and 63 presented greater tensile strength than G1. There was no significant difference between G2 and G3. All the failures took place at the ceramic/resin cement interface. Conclusion: The silica coating (Rocatec or CoJet systems) of the ceramic surface increased the bond strength between the Panavia F resin cement and alumina-based ceramic.

Diffusion ability of endotoxin through dentinal tubules

The aim of this study was to evaluate the ability of endotoxin to diffuse through dentinal tubules towards the cement and to observe the period of time needed for it to reach the external root surface. Thirty single-rooted human teeth had their crowns and apices removed in order to standardize the root length to 15 mm. Teeth were instrumented until #30 K-file and made externally impermeable with epoxy adhesive, leaving 10 mm of the exposed root (middle third). The specimens were placed in plastic vials and irradiated (60Co gamma-rays). Then, they were divided into 2 groups (n = 15): G1) Escherichia coli endotoxin was inoculated into the root canal of the specimens and 1 ml of pyrogen-free water was put in the tubes; G2) (control): pyrogen-free water was inoculated into the root canals and 1 ml of pyrogen-free water was put in each tube. After 30 min, 2 h, 6 h, 12 h, 24 h, 48 h, 72 h and 7 days, the water of the tubes was removed and replaced. The removed aliquot was tested for the presence of endotoxin. Considering that the endotoxin is a B-lymphocyte polyclonal activator, at each experimental period, B-lymphocyte culture was stimulated with a sample of water removed from each tube and antibody (IgM) production was detected by ELISA technique. The results of IgM production were higher in groups of 24 h, 48 h, 72 h and 7 days in relation to the other studied groups, with statistically significant differences (ANOVA and Tukey's test p < 0.05). Endotoxin was able to diffuse through the dentinal tubules towards the cement, reaching the external root surface after the period of 24 h.