[Postoperative pain treatment]. / Metody stosowane w usmierzaniu bólu pooperacyjnego.

Postoperative pain, arising due to surgical tissue injury, is most frequent type of pain found in clinical practice. In postoperative analgesia opioids still constitute the fundamental form of pain treatment, but the development of neurophysiology and neuropharmacology has allowed for the optimization of postoperative analgesia. Therefore, in order to potentialize the pain relief effect of opioids and/or inhibit the nociception process and its consequences, diverse drugs and therapies are used. The procedure is called multimodal analgesia and consists in the administration of opioids in conjunction with NMDA antagonists, COX inhibitors, cholecystokinin antagonists, agonists of muscarine receptors, agonists of alpha-2 receptors or cytokine inhibitors. An alternative or supplementary therapy in the postoperative period relies on local anaesthetic techniques or TENS. There also exists pre-emptive analgesia, whose aim is to safeguard the central nervous system from increased afferent nociceptive stimulation during the operation.

Effects of daily topical fluoride gels on resin composite degradation and wear.

OBJECTIVES: This in vitro study compares the effects of professional and consumer-applied topical fluorides on the weight, wear resistance and surface appearance of a resin composite containing barium boroaluminosilicate glass filler particles. METHODS: Prior to wear studies with a pin and disc apparatus, specimens were immersed for 6 min 10 times in water, three consumer-applied topical fluorides (1.1% NaF, 0.4% SnF2, or 0.5% APF gel) or a professionally applied topical fluoride (1.23% APF gel). Specimens were weighed before and after each immersion. Following wear studies, the specimen surfaces were visually evaluated using scanning electron microscopy. Weight changes were analyzed for significant differences using one-way ANOVA and Duncan's multiple range test (p = 0.01). Values of wear parameters were ranked and tested for significance using one-way ANOVA with least squares mean contrast (p = 0.05). RESULTS: Significant differences were found in the weight loss of specimens treated with different fluoride agents: 1.23% APF = 0.5% APF > 0.4% SnF2 > 1.1% NaF = water (p < or = 0.0001). Significant differences in initial wear depth (S(i)) occurred in the following samples: 1.23% APF > 1.1% NaF = 0.5% APF (p = 0.04). Scanning electron micrographs showed variable wear tracks on the specimen surfaces. The specimen surfaces outside the wear track were smooth for those treated with water or with NaF; the surfaces outside the wear track of specimens treated with APF showed extensive loss of filler particles. SIGNIFICANCE: Topical APF agents caused extensive loss of filler from the resin composite specimens whereas 1.1% NaF caused the least damage. Although significant differences in surface wear resistance were detected, clinical studies are needed to determine the effect of topical fluorides on the properties of this resin composite.

Effect of 1- and 4-minute treatments of topical fluorides on a composite resin.

The purpose of this in vitro study was to compare the effects of a 1-min immersion and of 4-min immersions in an acidulated phosphate fluoride (1.23% APF) foam, a 1.23% APF gel, a 2.0% sodium fluoride (NaF) gel, and water on surface topography and on weight of a composite resin (APH). Forty composite resin specimens were placed into eight groups (N = 5 each). For each treatment, a group of specimens was immersed for either 1 or 4 min (four 1-min immersions). Specimens were weighed before and after each immersion. The surface topography of two scanning electron micrographs of each specimen was scored visually by two investigators. Inter-rater reliability was r = 0.75 (intraclass correlation coefficient). There were no significant differences in the mean visual scores or weight among the 1-min immersion groups. Significantly greater surface changes and weight loss of this composite resin occurred following 4-min immersions in either 1.23% APF foam or gel as compared with those immersed in either 2.0% NaF gel or water (P 0.0001; one-way ANOVA, Tukey's Studentized Range Test).

The effect of topical APF foam and other fluorides on veneer porcelain surfaces.

Some topical fluorides cause surface changes in dental materials. The purpose of this study was to compare the effects of a topical acidulated phosphate sodium fluoride (1.23% APF) foam with the effects of other topical fluorides on the surface of veneer porcelain. Forty porcelain specimens (Ceramco) were placed into eight groups (N = 5). Four groups were immersed in either 1.23% APF foam, 1.23% APF gel, 2.0% sodium fluoride (NaF) gel, or water (reference) for 1 min. The other four groups were immersed in one of the above agents for four 1-min immersions. The surface topography of two scanning electron micrographs of each specimen was scored visually by two raters and by computer digital analysis (CDA). Inter-rater reliability was r = 0.67 (intraclass correlation coefficient). There were no significant differences in the mean visual scores or CDA scores among any of the groups immersed for 1 min. Porcelain immersed 4 min in APF gel had significantly greater mean visual scores and CDA scores than the other treatments (P < or = 0.0001; one-way ANOVA and Tukey's Studentized Range Test). The average surface topography scores of veneer porcelain immersed for 1 min in 1.23% APF gel, 2.0% NaF gel, 1.23% APF foam, or water were not significantly different. Significantly greater surface topography scores occurred following 4 min of immersion in 1.23% APF gel than all other agents.

Effects of electrical stimulation on lymphatic flow and limb volume in the rat.

BACKGROUND AND PURPOSE: The mechanism by which electrical stimulation affects edema has not been elucidated. The purpose of this study was to determine whether subcontraction high-voltage stimulation (SC-HVS) (ie, electrical stimulation that did not elicit a visible contraction) applied to the right hind limbs of rats would (1) alter the rate of lymphatic uptake of injected albumin labeled with Evans blue dye (AL-EBD) and (2) affect experimentally induced edema. SUBJECTS AND METHODS: The paws of 28 anesthetized Sprague-Dawley rats (mean weight = 263 g, SD = 48 g) were injected with AL-EBD. The experimental group (n = 13) received 1 hour of SC-HVS, and the control group (n = 15) received sham treatment consisting of the same treatment administered to the experimental group but without the SC-HVS. Blood samples and volume measurements were obtained at intervals over a 7-hour period. RESULTS: Analysis of variance and post hoc testing indicated that higher amounts of AL-EBD were taken up by the lymph of the experimental group animals as compared with the control group animals at each time period following the treatment. The experimental group's AL-EBD reached significance immediately after treatment, whereas the control group required an additional 4 hours. There was no significant reduction in limb volume in either group. CONCLUSION AND DISCUSSION: The SC-HVS significantly increased the uptake of AL-EBD by lymphatic vessels, but it did not cause a significant decrease in the induced edema. The results of this study indicate that SC-HVS has the potential to reduce edema by increasing lymphatic uptake of proteins.

The effect of topical fluorides on ceramic brackets.

Topical fluorides are frequently prescribed to orthodontic patients to minimize development of initial carious lesions around brackets and bands. However, various topical fluorides are reported to cause surface changes and weight loss of dental materials composed of ceramic elements. Little is known of the effects of these fluorides on ceramic brackets. The purpose of this study was to determine the effects of topical fluorides (0.4% stannous fluoride, 0.5% acidulated phosphate fluoride, and 1.1% sodium fluoride) as compared with water, on the weight and on the surface of the wings and slots of aluminum oxide ceramic brackets. The brackets (n = 10 each treatment agent) were weighed before 6-minute immersions in the treatment agent, rinsed, dried, and reweighed for a total of 10 immersions. The surface appearance of the wings and the slots of the brackets (n = 5 each treatment group) were evaluated with scanning electron microscopy. No statistically significant changes in weight were found among the groups. Surface changes were not observed in either the slots nor the wings of ceramic brackets. Therefore it was concluded that the commercially available topical fluorides when applied as per the regimen in this study to the aluminum oxide ceramic brackets did not cause surface damage or significant weight loss as compared with controls (water).

Effects of stimulus intensity and duration on posterior tibial nerve somatosensory-evoked potential patterns obtained under anesthesia.

STUDY DESIGN: This study analyzed systematic changes in stimulus intensity and duration on the latencies and amplitudes of somatosensory-evoked potential peaks obtained upon posterior tibial nerve stimulation of orthopedic patients under anesthesia. OBJECTIVES: To examine the effects of systematic stimulus changes on somatosensory-evoked potential patterns and to compare the sensitivity of different peaks. SUMMARY OF BACKGROUND DATA: Previous studies primarily examined the effects of either stimulus intensity or stimulus duration but not their interactions. METHODS: Nine orthopedic patients were tested using three stimulus intensities and three stimulus durations. Five peak latencies and four amplitudes were measured. Data consisted of frequency of peak occurrences under each condition and analyses of variances of peak latencies and amplitudes. RESULTS: Three latencies yielded stable findings (P40, N50, P60). Peak latencies under anesthesia were not affected by stimulus intensity or duration. Amplitudes, however, were affected differentially. P40-N50 increased with increases in stimulus intensity or stimulus duration, but no significant interaction effects were found. N50-P60 showed no significant changes associated with stimulus intensity or duration. CONCLUSION: Under combined isoflurane/nitrous oxide anesthesia, somatosensory-evoked potential patterns obtained upon stimulation of the posterior tibial nerves showed no significant changes in major peak latencies with changes in stimulus intensity or duration. However, changes in amplitude were found. Stimulus intensity-duration interaction effects were observed, described, and interpreted.

In vitro effect of topical fluorides on sealant materials.

The purpose of this study was to determine by visual inspection and by scanning electron microscopy (SEM) whether commercially available, topical, acidulated phosphate fluoride (APF) and neutral sodium fluoride (NaF) agents cause surface roughening of five sealant materials: two unfilled resins, two filled resins, and one glass-ionomer material. In addition, the effect of treatment with 1.23% APF and sonification on weight of an unfilled and a filled sealant was compared to treatment with controls. Unfilled sealants exhibited no surface changes visually or on micrographs following any treatment. Filled sealants and the glass-ionomer sealant exhibited visually apparent changes depending on the treatment. SEM inspection of filled sealants with visually apparent changes showed loss of filler particles whereas the glass-ionomer sealant exhibited apparent destruction both of the matrix and the filler particle. No significant differences in weight were found between sonicated and unsonicated specimens. However, significant loss of weight was found with filled sealant specimens, but not unfilled sealant specimens, treated with 1.23% APF gel as compared with the specimens treated with water. The results of this in vitro study indicate that preventive therapies that combine use of topical fluorides and sealants may cause deterioration of filled sealants and glass-ionomer sealant material, but not unfilled sealants.

Pharmacological evaluation of an intra-oral fluoride-releasing device in adolescents.

The purpose of this study was to quantify fluoride (F) concentrations in body fluids of adolescents wearing two intra-oral fluoride-releasing devices (IFRDs) designed to release 0.10 mg F/day. Fluoride concentrations were determined potentiometrically. No significant increases occurred in urine or serum F concentrations during the 26-week device phase. Elevated salivary F concentrations were maintained throughout the device phase when broken or depleted IFRDs were replaced. However, salivary F concentrations returned to pre-device phase values by 26 weeks when the original IFRDs were maintained. These findings suggest that IFRDs can significantly elevate salivary F concentrations of adolescents without significant elevations in systemic F concentrations.

EPR characterization of the iron-sulfur clusters in the NADH: ubiquinone oxidoreductase segment of the respiratory chain in Paracoccus denitrificans.

The physicochemical properties of the iron-sulfur clusters present in the NADH:ubiquinone oxidoreductase of Paracoccus denitrificans have been examined in the cytoplasmic membrane particles by redox potentiometry and EPR spectroscopy. Analogous to the iron-sulfur clusters present in the mitochondrial NADH: ubiquinone oxidoreductase, we have found two binuclear and three tetranuclear EPR detectable iron-sulfur clusters, namely, N-1a, N-1b, N-2, N-3, and N-4. In the bacterial system, the two binuclear clusters differ in line shape and in Em values; the cluster with more rhombic symmetry (gx,y,z = 1.918, 1.937, 2.029) has the Em7.0 value of -150 while the almost axial one (gx,y,z = 1.929, 1.941, 2.019) has Em7.0 of -270 mV. The Em of the former cluster is pH dependent (-60 mV/pH) as in the case of mammalian N-1a while the latter is pH independent as is the mammalian cluster N-1b. The pH-dependent P. denitrificans [2Fe-2S] cluster, which we have labeled N-1a, has an Em7.0 as high as that of N-2, in contrast to the mammalian N-1a. Thus N-1a is reducible with a physiological reductant, NADH in this bacterial system. The Em of the cluster N-2 is also pH dependent (Em7.0 = -130 mV) with a pK value near 7.7. The Em values of all other clusters exhibit no pH dependence as in the case of their mammalian counterparts. We have found that the cluster N-1a is the most labile component among the five iron-sulfur clusters and may give rise to variable relative spin concentrations and extremely low Em values due to the facile modifications of the microenvironment of the cluster. The P. denitrificans NADH:ubiquinone oxidoreductase provides a unique and useful site I model system where redox composition is similar to the mitochondrial enzyme but with fewer numbers of polypeptides (Yagi, T. (1986) Arch. Biochem. Biophys. 250, 302-311).

Oxidation-reduction potentials of respiratory chain components in Thiobacillus A2.

(1) Cells of Thiobacillus A2 grown chemoautotrophically on thiosulfate or heterotrophically on succinate with oxygen contained b-, c-, o-, a- and a3-type cytochromes. The amount of cytochrome per mg of cell protein was much greater in thiosulfate-grown cells and differences in the relative concentrations of cytochromes were observed for the different growth conditions. (2) The half-reduction potentials at pH 7.0 (Em,7.0) and spectral maxima of c-, b-, a- and a3-type cytochromes were similar in cells grown aerobically with thiosulfate or with succinate as the growth substrate. (3) The half-reduction potential of the 'invisible', or high-potential copper, as determined from the potentiometric behavior of the carbon monoxide-reduced cytochrome a3 complex at pH 8.0, was 365 mV. (4) Reducing equivalents from thiosulfate appear to enter the respiratory chain at the cytochrome c level; however, studies in cell-free extracts were limited due to a loss in respiratory activity with thiosulfate as a substrate upon cell disruption.

Midpoint potentials of cytochromes in vesicles of anaerobically-grown Paracoccus denitrificans determined by the indirect coulometric titration method.

1. Multiplicity of redox components with spectral properties similar to b-type cytochromes was established in vesicles derived fro anaerobically-grown Paracoccus denitrificans. 2. Multiplicity of c-type cytochromes was not apparent either from low temperature spectroscopy or potentiometric titrations. 3. Cytochromes a + a3 and a component, only observable at liquid nitrogen temperature, with a spectral maximum at 582.5 nm were detected. 4. Redox cycling of electron transport components using the indirect coulometric titration method was a convenient means of pairing redox potentials and was reproducible in total absorbance changes, midpoint potentials and spectral maxima.