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Saline Solution (saline + solution)
Kinds of Saline Solution Selected AbstractsCardiovascular and Pulmonary Effects of Hetastarch Plus Hypertonic Saline Solutions during Experimental Endotoxemia in Anesthetized HorsesJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 6 2006DACVIM, Lucas G. Pantaleon MV Background:Small volume resuscitation has been advocated as a beneficial therapy for endotoxemia in horses but this therapy has not been investigated in a prospective manner. The objective of this study was to determine the cardiopulmonary effects of small-volume resuscitation using hypertonic saline solution (HSS) plus Hetastarch (HES) during experimental endotoxemia in anesthetized horses. Hypothesis:Treatment of horses with induced endotoxemia using HES-HSS does not alter the response of various cardiopulmonary indices when compared to treatment with either small-or large-volume isotonic crystalloid solutions. Animals:Eighteen healthy horses were randomly assigned to 1 of 3 groups. Anesthesia was maintained with halothane. Endotoxemia was induced by administering 50 ,g/kg of Escherichia coli endotoxin IV. The horses were treated over 30 minutes with 15 mL/kg of balanced polyionic crystalloid solution (control), 60 mL/kg of balanced polyionic crystalloid solution (ISO), or 5 mL/kg of HSS followed by 10 mL/kg of HES (HSS-HES). Methods:Prospective randomized trial. Results:Cardiac output (CO) after endotoxin infusion increased significantly (P < .05) from baseline in all groups, whereas mean central venous pressure increased significantly (P < .05) in the ISO group only. Mean pulmonary artery pressure increased from baseline (P < .05) in horses treated with isotonic fluids and HSS-HES. There was no effect of treatment with HSS-HES on CO, systemic vascular resistance (SVR), mean arterial pressure, blood lactate concentrations, or arterial oxygenation. Conclusions and Clinical Importance: The use of HSS-HES failed to ameliorate the deleterious hemodynamic responses associated with endotoxemia in horses. The clinical value of this treatment in horses with endotoxemia remains unconfirmed. [source] An investigation into the influence of counterion on the RS -propranolol and S -propranolol skin permeabilityJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 3 2010Francesco Cilurzo Abstract The effects of two contra-ions, namely benzoate (Bz) and oleate (Ol), on the in vitro human skin permeability of propranolol racemate (RS -PR) or S -enantiomer (S -PR) were studied. Saline solution (SS) or mineral oil (MO) were selected as vehicles. The MO increased the permeability coefficient (Kp) of PR-Bz (pKp,,,4) of about four times with respect to SS (pKp,,,8) probably due to the ion pair formation. The steady-state flux of S -enantiomers resulted about twofold higher than that of racemates according to their lower melting temperatures with the exception of (S)-PR-Ol and (RS)-PR-Ol vehicled in SS which not resulted statistically different. This anomalous result could be explained considering the behavior of (RS)-PR-Ol or (S)-PR-Ol in aqueous solutions: these salts formed ion pairs which associated to form aggregates up to a concentration of 20,µg/mL as verified by light scattering. Therefore, their effective concentrations in SS resulted similar and justified the overlapped skin permeation profiles. All three considered variables, namely counterion, vehicle, and chirality, resulted mutually interfering on and deeply influenced the passive diffusion process of PR. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 1217,1224, 2010 [source] Wear of the artificial hip joint material under lubricationASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2009E. P. J. Waters Abstract A study of wear properties of hip-replacement materials, namely high-nitrogen stainless-steel femoral heads and ultra-high molecular weight polyethylene (UHMWPE), was conducted in a non-conforming apparatus using various liquid lubricants. The liquids used were normal saline solution, sodium azide solution, pure ethanol, aqueous hyaluronic acid and aqueous hyaluronic acid/cholesterol and cholesterol palmitate liquid crystal lubricant. Saline solution proved to be unsuitable as a lubricant while sodium azide that was used as a bactericide provided some evidence of mixed lubrication. A bactericide was included to overcome degradation. The aqueous hyaluronic acid exhibited cushion form lubrication as evidenced by retention of the original polymer surface features within the wear indent. Cholesterol addition showed little improvement on the wear properties but massively increased the bacterial activity. Again, inclusion of a bactericide was necessary. Liquid crystal lubricant significantly reduced wear and the atomic force microscope (AFM) showed that the liquid crystal formed protective layers on the counter face surfaces. The sub-surface of the polymer possessed plastic creep under load but low adhesive wear was present. There also was an absence of sub-micron polymer debris. It was concluded that a dramatic reduction in wear could be achieved by incorporation of liquid crystal lubricant in hip-replacement elements. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Properties of a concentrated minipool solvent-detergent treated cryoprecipitate processed in single-use bag systemsHAEMOPHILIA, Issue 5 2008T. BURNOUF Summary., Cryoprecipitate is still used to treat factor VIII (FVIII), von Willebrand factor (VWF) and/or fibrinogen deficiency. Recently a solvent-detergent (S/D) process of minipools of cryoprecipitate performed in a closed bag system has been designed to improve its viral safety. Still, cryoprecipitate has other drawbacks, including low concentration in active proteins, and presence of haemolytic isoagglutinins. We report here the biochemical evaluation of S/D-treated minipools of cryoprecipitates depleted of cryo-poor plasma. Cryoprecipitates were solubilized by 8 mL of a sterile glucose/saline solution, pooled in batches of 40 donations and subjected to S/D treatment in a plastic bag system using either 2% TnBP or 1% TnBP-1%Triton X-45, followed by oil extractions (n = 10). Mean (±SD) FVIII and fibrinogen content was 8.86 (±1.29) IU mL,1 and 16.02 (±1.98) mg mL,1, and 8.92 (±1.05) IU mL,1 in cryoprecipitate minipools treated with 2% TnBP, and 17.26 (±1.71) mg mL,1, in those treated by TnBP-Triton X-45, respectively. The WWF antigen, ristocetin cofactor and collagen binding activities were close to 10, 7 and 8 IU mL,1, respectively, and were not affected by either SD treatment. VWF multimeric pattern of SD-treated cryoprecipitates were similar to that of normal plasma, and the >15 mers and >10 mers content was identical to that of the starting cryoprecipitates. The anti-A and anti-B titre was 0,1 and 0,1/8, respectively. Therefore, it is possible to prepare virally inactivated cryoprecipitate minipools depleted of isoagglutinins and enriched in functional FVIII, VWF and clottable fibrinogen. [source] 1,8-Cineole induces relaxation in rat and guinea-pig airway smooth muscleJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2009Nilberto Robson Falcão Nascimento Abstract Objectives 1,8-Cineole is a monoterpene with anti-inflammatory, vascular and intestinal smooth muscle relaxant activity. We have evaluated the potential bronchodilatatory activity of this compound. Methods 1,8-Cineole was tested against carbachol, histamine, K+ 80 mM and ovalbumin-induced bronchial contractions in Wistar rat or guinea-pig tissues. Some of the guinea-pigs had been previously sensitized with an intramuscular injection of 5% (w/v) ovalbumin/saline solution. Control animals received 0.3 ml saline. In separate experimental groups the response to 1,8-cineole (1,30 mg/kg), phenoterol (0.05,5 mg/kg) or vehicle (0.3% Tween in saline) was studied. Key findings 1,8-Cineole decreased, in vivo, rat bronchial resistance with similar efficacy as phenoterol (66.7 ± 3.2% vs 72.1 ± 5.3%). On the other hand, the maximal relaxant response to 1,8-cineole in carbachol-precontracted rat tracheas was 85.5 ± 5.7% (IC50 = 408.9 (328,5196) ,g/ml) compared with 80.2 ± 4.8% (IC50 = 5.1 (4.3,6.1) ,g/ml) with phenoterol. The addition of 1,8-cineole to guinea-pig tracheal rings tonically contracted with K+ 80 mM induced a concentration-related relaxation. The maximal relaxation elicited by 1,8-cineole was 113.6 ± 11.7% (IC50 127.0 (115.9,139.2) ,g/ml) compared with 129.7 ± 14.6% (IC50 0.13 (0.12,0.14) ,g/ml) achieved after phenoterol administration. In addition, the incubation of tracheal rings with 1,8-cineole (100, 300 or 1000 ,g/ml), 15 min before inducing phasic contractions with K+ 80 mM, decreased the maximal amplitude of the contraction by 31.6 ± 4.6, 75.7 ± 2.7 and 92.2 ± 1.5%, respectively. In another set of experiments, neither the maximal response nor the IC50 for the 1,8-cineole-induced relaxation were different between normal and ovalbumin-sensitized tissues. Moreover, the relaxation of bronchial rings contracted after exposure to 1 ,g/ml ovalbumin occurred at a faster rate in rings pre-incubated with 1,8-cineole when compared with rings pre-incubated with vehicle only (Tween 0.3%). Therefore, in the first minute after the antigen challenge, the tracheal tissue relaxed after the peak contraction by 6.5, 21.4 (P < 0.05 vs control) and 66.9% (P < 0.05 vs control) in the presence of 100, 300 or 1000 ,g/ml 1,8-cineole, respectively. Conclusions 1,8-Cineole relaxed rat and guinea-pig (nonsensitized and ovalbumin-sensitized) airway smooth muscle by a nonspecific mechanism. [source] Evaluation of tooth-fragment reattachment: a clinical and laboratory studyDENTAL TRAUMATOLOGY, Issue 4 2010Yucel Yilmaz Materials and Methods:, The clinical study was conducted on 43 fractured incisors: 22 uncomplicated crown fractures (Group A) and 21 complicated crown fractures (Group B). The 43 incisal fragments: 23 were kept dry for 47 h and 20 were kept wet for 24 h by the patients before they were reattached. The fragments were kept in 0.9% saline solution for 30 min before reattachment. The fragments in Group A were reattached using a dentin bonding agent, a flowable and a hybrid resin composite, whereas the fragments in Group B were reattached to the tooth remnant after a pulpotomy was performed. The laboratory study was conducted on 56 extracted incisors. Teeth were divided equally into four groups: Group I , Uncomplicated crown fracture + wet medium; Group II , Uncomplicated crown fracture + dry medium; Group III , Complicated crown fracture + wet medium, and Group IV , Complicated crown fracture + dry medium. The fragments were then reattached in a manner that was similar to that used in the clinical study. The restored teeth were then re-fractured. All data were analyzed statistically. Results: In the clinical study, the restored teeth were followed up for 2 years. Neither the type of trauma nor the storage medium had any significant effect on the survival, color, and bond strength of the restored teeth when assessed in the clinical and laboratory study. The color disharmony that was encountered initially in restored teeth resolved significantly on its own accord within 12 months after reattachment of the fragment. Conclusion: Fragment reattachment can be used to treat fractured teeth successfully in children and adolescents. [source] Mechanical behavior of bovine periodontal ligament under tension-compression cyclic displacementsEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2006Tatsuya Shibata In the present study, the mechanical response of bovine periodontal ligament (PDL) subjected to displacement-controlled tension,compression harmonic oscillations and subsequent rupture was examined. Specimens including dentine, cementum, PDL, and alveolar bone were extracted from different depths and locations of bovine first molars. They were immersed in a saline solution at room temperature and clamped on their bone and dentine extremities. The samples were tested at ±35% of the PDL's width, with a frequency of 1 Hz. The mechanical parameters evaluated were hysteresis, phase lag, and the modulus of the stress,stretch ratio curves in tension and compression. The tensile strength and the corresponding stretch ratio were also recorded. Stress,stretch ratio curves indicated a non-linear, time-dependent response with hysteresis and preconditioning effects. The hysteresis and phase lag in compression were much higher than in tension, suggesting that the dissipated energy was higher in compression than in tension. The root depth and location did not play essential roles for the tension or compression data, with the exception of limited statistical differences for tensile strength and corresponding stretch ratio. Thus, biological variability in the specimens, as a result of different bone contours, PDL width, and fiber orientation, did not affect the energy-absorbing capacity of the PDL. The evolution of the stress rate with stress demonstrated a constant increase of stiffness with stress. The stiffness values were twofold higher in tension than in compression. The data also showed that the stiffness of the PDL was comparable with data reported for other soft tissues. [source] Two-thumb vs Two-finger Chest Compression in an Infant Model of Prolonged Cardiopulmonary ResuscitationACADEMIC EMERGENCY MEDICINE, Issue 10 2000Michele L. Dorfsman MD Abstract. Objective: Previous experiments in the authors swine lab have shown that cardiopulmonary resuscitation (CPR) using two-thumb chest compression with a thoracic squeeze (TT) produces higher blood and perfusion pressures when compared with the American Heart Association (AHA)-recommended two-finger (TF) technique. Previous studies were of short duration (1-2 minutes). The hypothesis was that TT would be superior to TF during prolonged CPR in an infant model. Methods: This was a prospective, randomized crossover experiment in a laboratory setting. Twenty-one AHA-certified rescuers performed basic CPR for two 10-minute periods, one with TT and the other with TF. Trials were separated by 2-14 days, and the order was randomly assigned. The experimental circuit consisted of a modified manikin with a fixed-volume arterial system attached to a neonatal monitor via an arterial pressure transducer. The arterial circuit was composed of a 50-mL bag of normal saline solution (air removed) attached to the manikin chest plate and connected to the transducer with a 20-gauge intravenous catheter and tubing. Rescuers were blinded to the arterial pressure tracing. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded in mm Hg, and pulse pressures (PPs) were calculated. Data were analyzed with two-way repeated-measures analysis of variance. Sphericity assumed modeling, with Greenhouse-Geisser and Huynh-Feldt adjustments, was applied. Results: Marginal means for TT SBP (68.9), DBP (17.6), MAP (35.3), and PP (51.4) were higher than for TF SBP (44.8), DBP (12.5), MAP (23.3), and PP (32.2). All four pressures were significantly different between the two techniques (p , 0.001). Conclusion: In this infant CPR model, TT chest compression produced higher MAP, SBP, DBP, and PP when compared with TF chest compression during a clinically relevant duration of prolonged CPR. [source] The action of high K+ and aglycaemia on the electrical properties and synaptic transmission in rat intracardiac ganglion neurones in vitroEXPERIMENTAL PHYSIOLOGY, Issue 2 2009Jhansi Dyavanapalli We have investigated the action of two elements of acute ischaemia, high potassium and aglycaemia, on the electrophysiological properties and ganglionic transmission of adult rat intracardiac ganglion (ICG) neurones. We used a whole-mount ganglion preparation of the right atrial ganglion plexus and sharp microelectrode recording techniques. Increasing extracellular K+ from its normal value of 4.7 mm to 10 mm decreased membrane potential and action potential after-hyperpolarization amplitude but otherwise had no effect on postganglionic membrane properties. It did, however, reduce the ability of synaptically evoked action potentials to follow high-frequency (100 Hz) repetitive stimulation. A further increase in K+ changed both the passive and the active membrane properties of the postganglionic neurone: time constant, membrane resistance and action potential overshoot were all decreased in high K+ (20 mm). The ICG neurones display a predominantly phasic discharge in response to prolonged depolarizing current pulses. High K+ had no impact on this behaviour but reduced the time-dependent rectification response to hyperpolarizing currents. At 20 mm, K+ practically blocked ganglionic transmission in most neurones at all frequencies tested. Aglycaemia, nominally glucose-free physiological saline solution (PSS), increased the time constant and membrane resistance of ICG neurones but otherwise had no action on their passive or active properties or ganglionic transmission. However, the combination of aglycaemia and 20 mm K+ displayed an improvement in passive properties and ganglionic transmission when compared with 20 mm K+ PSS. These data indicate that the presynaptic terminal is the primary target of high extracellular potassium and that aglycaemia may have protective actions against this challenge. [source] Efficacy of various concentrations of NaOCl and instrumentation techniques in reducing Enterococcus faecalis within root canals and dentinal tubulesINTERNATIONAL ENDODONTIC JOURNAL, Issue 1 2006V. B. Berber Abstract Aim, To evaluate the efficacy of 0.5%, 2.5% and 5.25% sodium hypochlorite (NaOCl) as intracanal irrigants associated with hand and rotary instrumentation techniques against Enterococcus faecalis within root canals and dentinal tubules. Methodology, A total of 180 extracted human premolar teeth were infected for 21 days with E. faecalis. The specimens were divided into 12 groups, as follows: group 1: 5.25% NaOCl + Hybrid technique (Valdrighi et al. 1998); group 2: 5.25% NaOCl + nickel,titanium (NiTi) rotary technique 4 mm shorter than the apex (by FOP-UNICAMP); group 3: 5, 25% NaOCl + NiTi rotary technique (Hero 642); group 4: 2.5% NaOCl +Hybrid technique; group 5: 2.5% NaOCl + NiTi rotary technique 4 mm shorter than the apex; group 6: 2.5% NaOCl + NiTi rotary technique (Hero 642); group 7: 0.5% NaOCl + Hybrid technique; group 8: 0.5% NaOCl + NiTi rotary technique 4 mm shorter than the apex; group 9: 0.5% NaOCl + NiTi rotary technique (Hero 642); group 10: sterile saline solution + Hybrid technique; group 11: sterile saline solution + NiTi rotary technique 4 mm shorter than the apex; group 12: sterile saline solution + NiTi rotary technique (Hero 642). Canals were sampled before and after preparation. After serial dilution, samples were plated onto brain heart infusion (BHI) agar, and the colony forming units (CFU) that were grown were counted. The teeth were sectioned into three thirds and dentine chips were removed from the canals with conical burs. The samples obtained with each bur were immediately collected into test tubes containing BHI broth, and were incubated at 37 °C and plated onto BHI agar. The CFU were counted and analysed. Results, At all depths and thirds of the root canals and for all techniques used, 5.25% NaOCl was shown to be the most effective irrigant solution tested when dentinal tubules were analysed, followed by 2.5% NaOCl. No differences among concentrations in cleaning the canals were found. Conclusions, Especially at higher concentrations, NaOCl, was able to disinfect the dentinal tubules, independent of the canal preparation technique used. [source] Effect of different irrigation solutions and calcium hydroxide on bacterial LPSINTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2003J. M. G. Tanomaru Abstract Aim, To evaluate the effect of biomechanical preparation with different irrigating solutions and calcium hydroxide dressing in dog root canals containing bacterial endotoxin (lipopolysaccharides; LPS). Methodology, One hundred and forty premolar roots from seven dogs were filled with Escherichia coli LPS for 10 days (three roots were lost during histological processing). The following irrigating solutions were used for biomechanical preparation: 1% (group I, n = 20), 2.5% (group II, n = 19) and 5% sodium hypochlorite (group III, n = 19), 2% chlorhexidine digluconate (group IV, n = 20) and physiological saline solution (group V, n = 19). In group VI (n = 20), the LPS solution was maintained in the root canal during the entire experiment and in group VII (n = 20), after biomechanical preparation with saline solution, the root canals were filled with a calcium hydroxide dressing (Calen; control). After 60 days, the animals were sacrificed and the following parameters of periapical disease were evaluated: (a) inflammatory infiltrate, (b) periodontal ligament thickness, (c) cementum resorption and (d) bone resorption. Scores were given and data were analysed statistically with the Kruskal,Wallis and Dunn tests (P < 0.05). Results, Histopathological evaluation showed that groups I,VI had more inflammatory infiltrate, greater periodontal ligament thickening and greater cementum and bone resorption (P < 0.05) compared to group VII, which received the calcium hydroxide intracanal dressing. Conclusions, Biomechanical preparation with the irrigating solutions did not inactivate the effects of the endotoxin but the calcium hydroxide intracanal dressing did appear to inactivate the effects induced by the endotoxin in vivo. [source] A scanning electron microscopic study of debris and smear layer remaining following use of GT rotary instrumentsINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2002G. Gambarini Abstract Aim The aim of the present study was to assess debris and smear layer remaining following canal preparation with GT rotary instruments. Methodology Sixteen freshly extracted single-rooted premolar teeth were instrumented with GTÔ rotary instruments using a crown-down preparation technique. All specimens were flushed with 2 mL of 5% NaOCl between each rotary instrument. At the end of instrumentation the following final irrigation sequence was repeated two times: 2 mL of EDTA + Cetrimide for 1 min (Largal Ultra, Septodont, France) and 2 mL of 5% NaOCl for 5 min. A final flush with saline solution was made to halt any chemical activity. Two other uninstrumented teeth that were not irrigated served as controls. All teeth were split longitudinally and prepared for SEM evaluation. The presence of debris and smear layer was evaluated from photomicrographs at ×200 and ×1000 magnification taken in the apical, middle and coronal thirds of the canals. Blind evaluation was performed by two trained observers and scores were compiled separately. A five category scoring system for debris and smear layer was used. Values obtained were tabulated and statistical analysis was carried out using a parametric chi-squared test. Results Statistical analysis showed that there was no significant difference between the three regions of the root canals (P > 0.05) for debris. Comparison of the removal of the smear layer between the three regions showed that there was a statistically significant difference between all parts, especially between the coronal and apical thirds (P < 0.001). Overall, the coronal sections were cleaner than the middle and apical sections. The uninstrumented canals showed walls completely covered with tissue, confirming that specimen preparation alone did not remove tissue. Conclusions Under the conditions of the present study GTÔ rotary instruments removed debris effectively, but left root canal walls covered with smear layer, particularly in the apical third. [source] Volume recovery, surface properties and membrane integrity of Lactobacillus delbrueckii subsp. bulgaricus dehydrated in the presence of trehalose or sucroseJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007E.E. Tymczyszyn Abstract Aims:, Although the practical importance of adding sugars before drying is well known, the mechanism of protection of bacteria by sugars is not clear. The response of the dehydrated micro-organisms to rehydration is analysed in terms of structural and functional changes, and correlated with their potentiality to grow in rich media. These aspects are related with the membrane integrity and the metabolic state of the rehydrated bacteria, measured by means of surface properties and permeability. To attain this objective, Lactobacillus delbrueckii subsp. bulgaricus was dehydrated in the presence and in the absence of sucrose and trehalose. The bacterial response upon rehydration was investigated by determining: (i) the lag time of the bacterial growing in rich media, (ii) the restoration of the surface properties and the cellular volume and (iii) the membrane integrity. Methods and Results:,Lactobacillus delbrueckii subsp. bulgaricus was grown in MRS at 37°C overnight [De Man et al. (1960)J Appl Bacteriol 23, 130] and then dehydrated for 10, 20 and 30 min at 70°C in a vacuum centrifuge. The lag time of micro-organisms was determined by optical density changes after rehydration. The surface properties were determined by measuring the zeta potential of the bacteria suspended in aqueous solution. The cellular volume recovery was measured, after stabilization in saline solution, by light scattering and by the haematocrit method [Alemohammad and Knowles (1974)J Gen Microbiol 82, 125]. Finally, the membrane integrity has been determined by using specific fluorescent probes [SYTO 9 and propidium iodide, (PI)] that bind differentially depending on the integrity of the bacterial membrane. The lag time of Lact. delbrueckii subsp bulgaricus, dehydrated by heat in the presence of sucrose or trehalose and after that rehydrated, was significantly shortened, when compared with that obtained for bacteria dried in the absence of sugars. In these conditions, trehalose and sucrose maintained the zeta potential and the cell volume close to the control (nondried) cells. However, the membrane integrity, measured with fluorescent probes, was maintained only when cells were dehydrated for 10 min in the presence of sugars. For larger times of dehydration, the membrane integrity was not preserved, even in the presence of sugars. Conclusions:, When the micro-organisms are dehydrated in the absence of protectants, the membrane damage occurs with a decrease in the absolute value of the zeta potential and a decrease in the cellular volume recovered after rehydration. In contrast, when the zeta potential and the cellular volume are restored after rehydration to that corresponding to nondried cells, the micro-organisms are able to recover and grow with a reduced lag time. This can only be achieved when the dehydration is carried out in the presence of sugars. At short dehydration times, the response is associated with the preservation of the membrane integrity. However, for longer times of dehydration the zeta potential and volume recovery occurs in the presence of sugars in spite of a severe damage at membrane level. In this condition, cells are also recovered. In conclusion, to predict the ability of growing after dehydration, other bacterial structural parameters besides membrane integrity, such as zeta potential and cellular volume, should be taken into account. Significance and Impact of the Study:, The correlation of the lag time with the surface and permeability properties is of practical importance because the correlation of these two parameters with cell viability, allow to determine the potential bacterial capacity to grow in a rich medium after the preservation procedure, without necessity of performing a kinetic curve of growth, which is certainly time-consuming. [source] Antibacterial polyvinyl chloride/antibiotic films: The effect of solvent on morphology, antibacterial activity, and release kineticsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010Martha Merchan Abstract Medical-grade polyvinyl chloride was modified with sodium ampicillin in a concentration range from 0 to 5 wt % by solvent casting technique using cyclohexanone and N,N -dimethylformamide. The obtained polymeric systems were characterized by optical microscopy, tensile test, and scanning electron microscopy. In addition, in vitro antibacterial activity against Gram-negative and Gram-positive bacteria was determined by an agar diffusion test. Antibiotic release experiments were performed in distilled water and physiological saline solution, which were monitored by UV-vis spectroscopy. The results showed a crucial role of the solvent on the morphology, antibacterial activity, and releasing characteristic of the ampicillin. Furthermore, a mathematical model was applied to data obtained from release study, to characterize the release kinetics of the ampicillin from the polyvinyl chloride-antibiotic systems. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Polycarbonate microspheres containing tumor necrosis factor-, genes and magnetic powder as potential cancer therapeuticsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Bin Hu Abstract Amphiphilic polycarbonate copolymers including methoxy-terminated poly(ethylene glycol)- co -poly (5,5-dimethyl trimethylene carbonate) [Poly(PEG- b -TMC)] and poly(ethylene glycol)- co -poly(trimethylene carbonate) [Poly(PEG- b -DTC)] were synthesized. The water-in-oil-in-water (W/O/W) solvent evaporation technique was adopted to produce anticancer magnetic Poly(PEG- b -DTC) microspheres containing tumor necrosis factor-, (TNF-,) genes and Fe3O4 magnetic ultrafine powder. Drug release studies showed that the microspheres can sustain a steady release rate of TNF-, genes in 0.1M phosphate buffer saline solution in vitro for up to 60 h. In vitro cytotoxicity assays demonstrated that the microspheres have high inhibition and antitumor action to human hepatocellular carcinoma (Bel-7204) cells in vitro. In vivo inhibition on the growth of hepatic carcinomas and histopathologic observation indicated that the microspheres possess a markedly high antitumor activity to human hepatocellular carcinoma (Bel-7204). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Enhancing the mechanical integrity of the implant,bone interface with BoneWelding® technology: Determination of quasi-static interfacial strength and fatigue resistanceJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2006Stephen J. Ferguson Abstract The BoneWelding® technology is an innovative bonding method, which offers new alternatives in the treatment of fractures and other degenerative disorders of the musculoskeletal system. The BoneWelding process employs ultrasonic energy to liquefy a polymeric interface between orthopaedic implants and the host bone. Polymer penetrates the pores of the surrounding bone and, following a rapid solidification, forms a strong and uniform bond between implant and bone. Biomechanical testing was performed to determine the quasi-static push-out strength and fatigue performance of 3.5-mm-diameter polymeric dowels bonded to a bone surrogate material (Sawbones solid and cellular polyurethane foam) using the BoneWelding process. Fatigue tests were conducted over 100,000 cycles of 20,100 N loading. Mechanical test results were compared with those obtained with a comparably-sized, commercial metallic fracture fixation screw. Tests in surrogate bone material of varying density demonstrated significantly superior mechanical performance of the bonded dowels in comparison to conventional bone screws (p < 0.01), with holding strengths approaching 700 N. Even in extremely porous host material, the performance of the bonded dowels was equivalent to that of the bone screws. For both cellular and solid bone analog materials, failure always occurred within the bone analog material surrounding and distant to the implant; the infiltrated interface was stronger than the surrounding bone analog material. No significant decrease in interfacial strength was observed following conditioning in a physiological saline solution for a period of 1 month prior to testing. Ultrasonically inserted implants migrated, on average, less than 20 ,m over, and interfacial stiffness remained constant the full duration of fatigue testing. With further refinement, the BoneWelding technology may offer a quicker, simpler, and more effective method for achieving strong fixation and primary stability for fracture fixation or other orthopaedic and dental implant applications. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source] Different protective actions of losartan and tempol on the renal inflammatory response to acute sodium overloadJOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2010María I. Rosón The aim of this work was to study the role of local intrarenal angiotensin II (Ang II) and the oxidative stress in the up-regulation of pro-inflammatory cytokines expression observed in rats submitted to an acute sodium overload. Sprague,Dawley rats were infused for 2,h with isotonic saline solution (Control group) and with hypertonic saline solution alone (Na group), plus the AT1 receptor antagonist losartan (10,mg,kg,1 in bolus) (Na,Los group), or plus the superoxide dismutase mimetic tempol (0.5,mg,min,1,kg,1) (Na,Temp group). Mean arterial pressure, glomerular filtration rate, and fractional sodium excretion (FENa) were measured. Ang II, NF-,B, hypoxia inducible factor-1, (HIF-1,), transforming growth factor ,1 (TGF-,1), smooth muscle actin (,-SMA), endothelial nitric oxide synthase (eNOS), and RANTES renal expression was evaluated by immunohistochemistry. Ang II, NF-,B, and TGF-,1 and RANTES early inflammatory markers were overexpressed in Na group, accompanied by enhanced HIF-1, immunostaining, lower eNOS expression, and unmodified ,-SMA. Losartan and tempol increased FENa in sodium overload group. Although losartan reduced Ang II and NF-,B staining and increased eNOS expression, it did not restore HIF-1, expression and did not prevent inflammation. Conversely, tempol increased eNOS and natriuresis, restored HIF-1, expression, and prevented inflammation. Early inflammatory markers observed in rats with acute sodium overload is associated with the imbalance between HIF-1, and eNOS expression. While both losartan and tempol increased natriuresis and eNOS expression, only tempol was effective in restoring HIF-1, expression and down-regulating TGF-,1 and RANTES expression. The protective role of tempol, but not of losartan, in the inflammatory response may be associated with its greater antioxidant effects. J. Cell. Physiol. 224:41,48, 2010 © 2010 Wiley-Liss, Inc. [source] Open flap debridement with or without intentional cementum removal: a 4-month follow-upJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2005Antonio Wilson Sallum Abstract Objectives: The aim of this study was to investigate the influence of cementum removal on periodontal repair. Material and Methods: Forty subjects with chronic periodontitis and presenting, at least, two proximal sites in anterior teeth (upper or lower) with probing depth 5 mm were selected. After oral hygiene instructions and ultrasonic supragingival instrumentation, the subjects were randomly assigned for one of the following groups: CIC, scaled with Gracey curettes; CIUS, scaled with ultrasonic device; CDC, calculus deattachment with Gracey curettes and brushing with saline solution; and CDUS, calculus deattachment with ultrasonic device and brushing with saline solution. Full-thickness flaps were reflected and the instrumentation was performed with a clinical microscope. Probing depth (PD), relative gingival margin level (RGML) and relative attachment level (RAL) were registered at five experimental periods: baseline and 30, 60, 90 and 120 days postoperative. Results: All the approaches were able to markedly reduce the PD values from the baseline to the other evaluation periods (p<0.0001). The increase in RGML values was statistically significant only for the CDUS group. There were no statistically significant differences between the baseline and postoperative values in all groups for the RAL changes. The changes in RAL were statistically significant only among the groups CDC and CDUS (p<0.0001). Conclusion: The conventional scaling and root planing and the calculus deattachment were effective in reducing the probing depth values, regardless of the instrumentation method. [source] Fracture Resistance of Endodontically Treated Teeth Restored with Three Different Prefabricated Esthetic PostsJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 1 2003PAULO C. A. MACCARI DDS ABSTRACT Purpose: This study was undertaken to evaluate the role of composition of prefabricated esthetic posts in fracture resistance of endodontically treated teeth in vitro. Materials and Methods: Thirty human, single-rooted teeth (maxillary central incisors and canines) with similar root dimensions, extracted for therapeutic reasons, were used in this study. The crowns were removed below the cementoenamel junction to obtain a standard root length of 17 mm. The roots were endodontically treated following the conventional manual technique and randomly assigned to three groups (n = 10) according to the post used: Aestheti-Post, Bisco, Schaumberg, Illinois; FibreKor Post, Jeneric/Pentron, Wallingford, Connecticut; and CosmoPost, Ivoclar Vivadent, Schaan, Liechtenstein. The root canals were rendered patent, and the root preparations were standardized through flaring with the manufacturers' drills included in the respective kits. The posts were cemented with an adhesive system and a resin cement (All-Bond 2 and C & B, Bisco, respectively), according to the manufacturers' directions. Composite resin (Tetric Ceram, Ivoclar Vivadent) crowns were built up using a preformed polyester matrix, and the specimens were mounted in metallic rings with cold-cure acrylic resin and kept in saline solution at 4°C for 24 hours. Fracture resistance was then determined using an EMIC DL-2000 universal testing machine. The crosshead speed was 0.5 mm/min with the 45-degree compressing load at the middle third of the crown. Data were analyzed using one-way analysis of variance and Tukey'stest (p<.001). Results: Mean fracture resistance was as follows: Aestheti-Post, 83.5 kgf; FibreKor Post, 85.7 kgf; and CosmoPost, 36.5 kgf. The fracture strength of CosmoPost was significantly lower than that of the other posts. Teeth restored with CosmoPost had post fractures, and in three specimens, those were associated with root fractures. Teeth restored with the other two posts presented fractures on the composite crowns. CLINICAL SIGNIFICANCE Compared with ceramic posts, carbon-fiber and glass-fiber prefabricated esthetic posts provide endodontically treated teeth higher fracture resistance. [source] Field validation of experimental challenge models for IPN vaccinesJOURNAL OF FISH DISEASES, Issue 12 2007A Ramstad Abstract Atlantic salmon S1/2 pre-smolts from the VESO Vikan hatchery were assigned to study groups, i.p. immunized with commercially available, multivalent oil-adjuvanted vaccines with (Norvax Compact 6 , NC-6) or without (Norvax Compact 4 , NC-4) recombinant infectious pancreatic necrosis virus (IPNV) antigen. A control group received saline solution. When ready for sea, the fish were transported to the VESO Vikan experimental laboratory, where two identical tanks were stocked with 75 fish per group before being transferred to 10 °C sea water and exposed by bath to first passage IPNV grown in CHSE-214 cells. The third tank containing 40 fish from each group was challenged by the introduction of 116 fish that had received an i.p injection of IPNV-challenge material. The remaining vaccinated fish were transported to the VESO Vikan marine field trial site and placed in two identical pens, each containing approximately 53 000 fish from the NC-6 group and 9000 fish from the NC-4 group. In the experimental bath challenge trial, the cumulative mortality was 75% and 78% in the control groups, and the relative percentage survival (RPS) of the NC-6-immunized fish vs. the reference vaccine groups was 60% and 82%, respectively. In the cohabitation challenge, the control mortality reached 74% and the IPNV-specific vaccine RPS was 72%. In both models, the reference vaccine lacking IPNV antigen gave a moderate but statistically significant non-specific protection. In the field, a natural outbreak of infectious pancreatic necrosis (IPN) occurred after 7 weeks lasting for approximately 3.5 months before problems due to winter ulcers became dominating. During this outbreak, mortality in the NC-4 groups were 33.5% and 31.6%, respectively, whereas mortality in the NC-6 groups were 6.9% and 5.3%, respectively, amounting to 81% IPNV-specific protection. In conclusion, the IPN protection estimates obtained by experimental challenges were consistent between tanks, and were confirmed by the field results. [source] Ferucarbotran expands area treated by radiofrequency ablation in rabbit liversJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 7pt2 2008Tatsuya Miyake Abstract Background and Aim:, Several studies have examined the factors involved with expansion of the coagulation volume following radiofrequency ablation (RFA). Ferucarbotran contains superparamagnetic iron oxide that generates heat in a radiofrequency electric field and may have an effect on the area affected by RFA. We attempted to determine whether ferucarbotran administration expands radiofrequency-ablated volume using a rabbit model. Methods:, A total of 15 male Japanese white rabbits (16 weeks old) were used and divided into three groups of five each. A 1-mL saline solution was given intravenously into a dorsal ear vein in the control group, whereas 1 mL ferucarbotran solution (0.016 mL/kg bodyweight) was given to the common-dose group and 1 mL of a twofold concentrated ferucarbotran solution (0.032 mL/kg bodyweight) was given to the high-dose group. RFA was performed with a cool-tip electrode 4 h after the administration and immediately thereafter the rabbits were killed, and the volume of the ablated area measured using magnetic resonance imaging (MRI). Following the MRI analysis, the rabbit's livers were resected, and the maximum short axis diameter of the ablated area in each was measured. Results:, None of the rabbits died during the RFA procedure. The volume of the ablated area estimated on MR images in the ferucarbotran-administered groups was larger than that in the control group. Further, our macroscopic assessment showed that the maximum short axis diameter had a tendency to increase with ferucarbotran administration. Conclusion:, Ferucarbotran may expand the area treated by RFA. [source] Effect of insulin on rat ovarian leptin expression by immunohistochemical stainingJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 6 2003Naci Kemal Kuscu Abstract Aim:, Leptin and insulin may interact in regulating ovarian steroid synthesis. The objective of this study was to investigate immunohistochemical staining of leptin in normal rat ovarian tissues and in rats treated with insulin and insulin plus human chorinoic gonadotropin (hCG). Methods:, Paraffin blocks of rat ovarian tissues from a previous study, in which 18 adult, female Wistar rats with an average weight of 250 g were divided into three groups to receive either saline solution, human insulin (2 U/day) or human insulin (2 U/day) plus hCG (4 U/day) for 4 weeks, were used in this study to compare the effects on leptin staining. The results were analysed using a semiquantitative scoring system, such as mild, moderate and strong. Results:, No staining was observed in granulosa cells and theca interna cells of normal ovarian tissues. Theca externa cells had mild staining intensity (+), corpus luteum had moderate (+ +) and stroma had mild (+) staining intensity. Histological structure was impaired in the insulin group, luteinized cells had mild staining, there was no difference in other cell groups. Only theca externa cells of the developing follicles were stained in insulin plus hCG group, luteinized cells again had mild staining. Conclusions: Besides damaging the rat ovarian structure, insulin reduced staining intensity of leptin in luteinized cells. Insulin may stimulate ovarian steroid synthesis not only through its own receptors, but also by acting on the leptin expression of these cells. [source] Whole-blood aggregometry: are there any limits with regard to platelet counts?ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2009A. M. MENGISTU Background: Whole-blood aggregometry (WBA) is a promising tool to assess platelet function in its physiological environment. Dilution of whole blood in WBA disregards platelet concentrations that may impact the results, especially in the case of low platelet counts. In a blinded, prospective in vitro study, the influence of platelet concentrations on WBA was assessed. Methods: Aggregation studies were carried out using whole blood from 10 healthy volunteers adjusted to platelet concentrations of 150, 100, 75, 50 and 25/nl using a plasma-balanced crystalloid solution. Platelet aggregation was measured by a new near-side whole blood aggregometer, activated by adenosin-diphosphate, collagen and thrombin-receptor activating protein. Three different approaches were applied: P1: whole blood diluted by an isotonic saline solution before activation, P2: undiluted whole blood with the single and P3: with the twofold concentration of the stimulating agent. Results: Aggregometry in diluted whole blood (P1) decreased significantly from a platelet concentration of 100/nl (P<0.01). In undiluted whole blood, aggregation declined significantly from concentrations of 75 and 50/nl for P2 and P3 (P<0.01). No correlation to platelet count occurred in the undiluted approaches until a platelet concentration of 75/nl, whereas correlation in the diluted test run was detected starting from 100/nl. Conclusions: This study demonstrates that WBA depends on the platelet count and sensitivity towards low platelet concentrations may be improved by abdication of further dilution and the use of undiluted whole blood. [source] Repeated intraarticular injections of triamcinolone acetonide alter cartilage matrix metabolism measured by biomarkers in synovial fluidJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2005Christophe Céleste Abstract Although intraarticular (IA) corticosteroids are frequently used to treat joint disease, the effects of their repeated use on articular cartilage remains controversial. The aim of our study was to determine the effects of a clinically recommended dose of IA triamcinolone acetonide (TA), on synovial fluid (SF) biomarkers of cartilage metabolism. Ten adult horses, free of osteoarthritis (OA) in their radiocarpal joints, were studied. One radiocarpal joint of each horse was randomly chosen for treatment and the contralateral anatomically paired joint acted as the control. Aseptic arthrocentesis was performed weekly on both joints for 13 weeks. The initial results from the first 3 weeks of the experimental period established baseline untreated control marker levels for each joint, each being its own control. On weeks 3, 5, and 7, a sterile suspension of 12mg of TA was injected into the treated joint and an equivalent volume of sterile saline solution (0.9%) was injected into the control joint. SF was immunoassayed for biomarkers of aggrecan turnover (CS 846 & KS), types I and II collagen cleavage (C1,2C) and type II collagen synthesis (CPII). In treated joints, there was a significant increase in CS 846, KS, C1,2C and CPII epitope concentrations following IA TA injections when compared to baseline levels. There was also a significant increase in C1,2C and CPII epitope concentrations in the contralateral control joints following IA TA injections in the treated joint. Significant differences were observed between treated and control joints for all markers except CPII. These findings indicate that TA alters articular cartilage and collagen metabolism in treated and, interestingly, also in control joints, suggesting a systemic effect of the drug. Though intuitively the observed findings would favor the hypothesis that long-term IA TA treatment changes joint metabolism and this may have detrimental effects; further studies would be necessary to confirm this. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Ultrastructural findings after intraarticular application of hyaluronan in a canine model of arthropathyJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2000W. Wenz We investigated the effect of intraarticularly applied hyaluronic acid (hyaluronan) on the cartilaginous structure of experimentally induced chondromalacia patellae in dogs. For the induction of chondromalacia, we used the Pond-Nuki technique, which involved severance and resection of the anterior cruciate ligament, as a canine model of arthropathy in 27 foxhounds (three groups of nine animals each). In a pilot study, we evaluated the effect of resection of the anterior cruciate ligament with no therapy. Patellar specimens were retrieved at 3, 6, and 12 weeks postoperatively. Subsequently, we compared a treatment group that received intraarticular injections of hyaluronan with a placebo group that received saline solution. The groups were compared at 3, 6, and 12 weeks postoperatively. Three animals from the treatment and placebo groups received five injections of hyaluronan during one of the 4-week intervals (weeks 3,6, 6,9, or 12,15). Specimens were retrieved 5 weeks after the last injection. In both groups, the uninvolved contralateral knee served as a control. The specimens were taken from the medial and lateral patellar poles. Histological analysis included light microscopy and transmission electron microscopy. The structural and ultrastructural changes were assessed qualitatively and were quantified with use of a modified Mankin score. Our results indicate that chondromalacia patellae may be induced with the Pond-Nuki technique. We found a significant reduction (p < 0.01) of cartilaginous lesions in the hyaluronan group compared with the placebo group. Our results suggest that intraarticularly applied hyaluronan is effective in delaying the degenerative process of cartilage degradation. Therefore, we conclude that the use of hyaluronan may be indicated during the early stages of chondromalacia. [source] Amelioration of disease severity by intraarticular hylan therapy in bilateral canine osteoarthritisJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2000K. W. Marshall Because of its high molecular weight, the glycosaminoglycan molecule hyaluronan is responsible for the viscoelastic properties of normal synovial fluid. In osteoarthritis, the concentration and molecular weight of hyaluronan in synovial fluid is diminished; this impairs the ability of synovial fluid to effectively lubricate joints, absorb loads, and exert anti-inflammatory effects. Using a bilateral anterior cruciateligament transection and partial neurectomy canine model of osteoarthritis, this study examined the effect of viscosupplementation with hylan G-F 20 as a treatment for osteoarthritis, this study examined the effect of viscosupplementation with hylan G-F 20 as a treatment for osteoarthritis. Twelve dogs underwent bilateral arthroscopic anterior cruciate-ligament transections and partial neurectomy of the knee joints. Beginning 1 week after the operation, six dogs received three weekly 500-,l injections of hylan G-F 20 in one knee and a sham injection of saline solution in the contralateral knee (early-treatment group). The remaining six animals underwent the same treatment 2 months following the procedure (late-treatment group). All dogs were killed at 8 months, and both knees were evaluated for gross pathology, histology, and proteoglycan content. In addition, with use of 500-MHz [1H] magnetic resonance spectroscopy, the synovial fluid from both knees was assessed for changes in metabolic profile. Differences in outcome were analyzed with paired t tests. Gross pathological and histological examination revealed significantly less severe changes of osteoarthritis in knees treated with hylan G-F 20 2 months after surgery than in the contralateral untreated knees. Magnetic resonance spectroscopy of the specimens in this late-treatment group showed significantly decreased glucose concentrations and significantly elevated isoleucine levels in the synovial fluid from knees treated with hylan G-F 20 compared with the controls. Previous magnetic resonance spectroscopy had shown that glucose concentrations increase with the onset of osteoarthritis and eventually diminish in end-stage osteoarthritis. The three injections of hylan were given after osteoarthritis was established, and the severity of the disease was ameliorated in the treated knees 6 months after treatment. This occurred although hylan G-F 20 is almost certainly cleared from joints by lymphatics within 4 weeks of injection, suggesting that hylan therapy can retard the progression of osteoarthritis for periods of time extending beyond the intraarticular residence time of the injected molecules and that hylan injections given at relatively early stages of osteoarthritis may have a chondroprotective effect. No changes in outcome were noted in the animals that received hylan G-F 20 immediately following surgery. [source] Effect of freeze-drying and gamma irradiation on the mechanical properties of human cancellous boneJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2000O. Cornu Freeze-drying and gamma irradiation are commonly used for preservation and sterilization in bone banking. The cumulative effects of preparation and sterilization of cancellous graft material have not been adequately studied, despite the clinical importance of graft material in orthopaedic surgery. Taking benefit from the symmetry of the left and right femoral heads, the influence of lipid extraction followed by freeze-drying of a femoral head and a final 25-kGy gamma irradiation was determined, with the nonirradiated, nonprocessed counterpart as the control. Five hundred and fifty-six compression tests were performed (137 pairs for the first treatment and 141 pairs for the second). Mechanical tests were performed after 30 minutes of rehydration in saline solution. Freeze-dried femoral heads that had undergone lipid extraction experienced reductions of 18.9 and 20.2% in ultimate strength and stiffness, respectively. Unexpectedly, the work to failure did not decrease after this treatment. The addition of gamma irradiation resulted in a mean drop of 42.5% in ultimate strength. Stiffness of the processed bone was not modified by the final irradiation, with an insignificant drop of 24%, whereas work to failure was reduced by a mean of 71.8%. Freeze-dried bone was a bit less strong and stiff than its frozen control. Its work to failure was not reduced, due to more deformation in the nonlinear domain, and it was not brittle after 30 minutes of rehydration. Final irradiation of the freeze-dried bone weakened its mechanical resistance, namely by the loss of its capacity to absorb the energy (in a plastic way) and a subsequent greater brittleness. [source] Histometric evaluation of the effect of nicotine administration on periodontal breakdown: an in vivo studyJOURNAL OF PERIODONTAL RESEARCH, Issue 6 2001Francisco H. Nociti Jr The present study investigated the effect of nicotine administration on periodontal breakdown resulting from ligature-induced periodontitis in rats. Twenty adult male Wistar rats were used. After anesthesia, a mandibular first molar was randomly assigned to receive a cotton ligature in the sulcular area while the contralateral tooth was left unligated. The animals were randomly assigned to one of the following treatments, of daily intraperitoneal injections: A , saline solution, B , 0.37 mg of nicotine/kg, C , 0.57 mg of nicotine/kg and D , 0.73 mg of nicotine/kg. Thirty days later, the animals were sacrificed and the specimens routinely processed for serial decalcified sections. Statistical analysis (ANOVA) revealed greater bone loss (p<0.05) in the ligated teeth of animals which received nicotine (groups B/C/D) than in the ligated teeth of animals which received saline solution (group A). In addition, a dose-dependent response was observed among the nicotine groups. A negative effect of nicotine was observed in the unligated teeth of the experimental groups (p<0.05). Therefore, daily administration of nicotine enhanced, in a dose-dependent manner, the effects of local factors in producing periodontal breakdown. Furthermore, the nicotine seemed to have a direct deleterious effect on the periodontal tissues. [source] Analgesic Effects of Ethanol Are Influenced by Family History of Alcoholism and NeuroticismALCOHOLISM, Issue 8 2010Elizabeth Ralevski Background:, Although personality factors and family history of substance abuse influence how individuals experience pain and respond to analgesics, the combined effects of those factors have not been extensively studied. The objective of this study was to consider the possible role of personality trait of neuroticism and family history of alcoholism on the experience of pain and their role in the analgesic response to an ethanol challenge. Methods:, Forty-eight healthy subjects participated in this study; thirty-one had a positive family history of alcoholism (FHP), seventeen had a negative family history of alcoholism (FHN). They were also categorized based on their neuroticism (N) scores (low N = 28, and high N = 20). This was a double-blind, placebo-controlled, randomized, within-subject design study of intravenous administration of three doses of ethanol. The testing consisted of 3 separate test days scheduled at least 3 days apart. Test days included a placebo day (saline solution), low-exposure ethanol day (targeted breathalyzer = 0.040 g/dl), and high-exposure ethanol day (targeted breathalyzer = 0.100 g/dl). Noxious electrical stimulation and pain assessments were performed prior to start of infusion and at the 60-minute infusion mark. Results:, The analgesic effect of ethanol was mediated by an interaction between the personality trait of neuroticism and family history. Individuals with family history of alcoholism and high N scores reported significantly more analgesia on low dose of ethanol than those with low N scores. There was no difference in the analgesic response to ethanol among FHNs with low and high N scores. Conclusion:, These findings support the conclusion that neuroticism and family history of alcoholism both influence the analgesic response of alcohol. Individuals with high N scores and FHP have the strongest response to ethanol analgesia particularly on the low exposure to alcohol. [source] Michaelis-Menten Elimination Kinetics of Acetaldehyde During Ethanol OxidationALCOHOLISM, Issue 2002Tatsuya Fujimiya Background Acetaldehyde (AcH) is a toxic metabolite of ethanol (EtOH). The pharmacokinetics of blood AcH during EtOH oxidation was studied with or without the administration of aldehyde dehydrogenase 2 inhibitor (cyanamide) in rabbits. Methods An bolus of EtOH saline solution (0.25, 0.5, 1.0, 1.5, and 2.0 g/kg) was injected intravenously. Cyanamide was administered intraperitoneally (25 mg/kg body weight) to the cyanamide-treated group. Blood EtOH and AcH concentrations were measured by using head-space gas chromatography. Results In the control group, the first peak of the blood AcH appeared immediately and the second elevation appeared 1 to 4 hr after administration at a high EtOH dose. The blood AcH levels other than the second elevation part were significantly correlated to the blood EtOH levels. In the cyanamide-treated group, a peak and a plateau formed at the time corresponding to the second peak in the control group. The peak and plateau concentration of AcH increased markedly. We attempted simultaneous curve fitting, using the five blood EtOH and AcH concentration-time curves, to determine the pharmacokinetic model. Consequently, the AcH elimination was best described by a Michaelis-Menten kinetic model in both groups. Conclusions The blood AcH profile was suggested to consist of the first and second components that are related to the blood EtOH concentration itself and the metabolic formation of AcH, respectively. With higher EtOH doses or aldehyde dehydrogenase 2 inhibition, the second component becomes prominent as a result of the capacity-limited property of the metabolism of AcH, which is described by Michaelis-Menten elimination kinetics. [source] | ||||||||||||||||||||||||||||||||||||||||