ABSTRACT
It has been demonstrated that long-term administration of doxazosin, an alpha 1 adrenoceptor antagonist, causes an up-regulation in the expression of alpha 1 adrenoceptor subtype mRNAs in the rat genitourinary tract. The aim of this study is to determine whether this up-regulation does have any effect on contractile response of rabbit bladder neck to adrenaline, acethylcholine and papaverin after long-term doxazosin treatment. Fourteen rabbits, treated with doxazosin 3 mg/kg/day p.o for 6 months, and were fed with a diet of standard laboratory rabbit chow (100 g/kg/day). Ten rabbits received the same amount of regular chow but no drug. Contractile responses of rabbit bladder neck to adrenaline acethylcholine and papaverine were measured.
Subject(s)
Acetylcholine/pharmacology , Doxazosin/pharmacology , Epinephrine/pharmacology , Muscle Contraction/drug effects , Papaverine/pharmacology , Urinary Bladder/drug effects , Animals , Dose-Response Relationship, Drug , Male , Muscle Relaxation/drug effects , Rabbits , RatsABSTRACT
The purpose of this study was to explore morphologic, functional, and behavioral effects of rough (sandblasted-large grid/acid-etched (SLA) and TiO2 blasted), mechanically polished, and mechanochemically polished titanium implant surfaces on nerves. The compound action potentials (cAPs) of sciatic nerves of sacrificed Wistar rats (n=10) were quantified at the in vitro level, while contacting disk-shaped test specimens. The test specimens were also implanted directly on the sciatic nerves of another group of animals (n=33), hot-plate tests were undertaken for 10 consecutive days, and then the animals were sacrificed. Quantification of signal transduction speeds and cAPs of the nerves of these animals were undertaken at the in vitro level. Finally, the nerves were processed for histologic analysis. The signal transduction speeds and duration of cAPs of all groups were similar (P>0.05), whereas the amplitudes of cAPs of nerves contacting SLA implants were higher than those of TiO2 blasted and mechanochemically polished surfaces (P<0.05). Response latencies of nerves contacting mechanically polished specimens were slightly higher than the other groups (P>0.05). Histologic evaluations did not reveal any signs of adverse tissue response adjacent to specimens tested. Rough and polished titanium implant surfaces lead to similar neural response in vivo and in vitro that fall into physiologic limits.
Subject(s)
Acid Etching, Dental , Air Abrasion, Dental , Biocompatible Materials/chemistry , Dental Materials/chemistry , Dental Polishing , Nanostructures/chemistry , Sciatic Nerve/physiopathology , Titanium/chemistry , Action Potentials/physiology , Animals , Dental Implants , Female , Hot Temperature , Neural Conduction/physiology , Pain Threshold/physiology , Rats , Rats, Wistar , Reaction Time/physiology , Reflex/physiology , Sciatic Nerve/pathology , Signal Transduction/physiology , Surface PropertiesABSTRACT
OBJECTIVES: The relative benefits of strategic leukofiltration on polymer-coated and low-dose heparin protocol on heparin-coated circuits were studied across EuroSCORE patient risk strata for three different cohorts. METHODS: In a prospective, randomized study, 270 patients undergoing coronary artery bypass grafting were allocated into three groups (n = 90): Group 1 - polymethoxyethylacrylate-coated circuits + leukocyte filters; Group 2 - polypeptide-based heparin-bonded circuits with reduced heparinization; and Group 3--CONTROL: uncoated circuits. Each group was further divided into three subgroups (n = 30), with respect to low- (EuroSCORE 0-2), medium- (3-5), and high- (6+) risk patients. Blood samples were collected at T1: following induction of anesthesia; T2: following heparin administration; T3: 15 min after CPB; T4: before cessation of CPB; T5: 15 min after protamine reversal; and T6: ICU. RESULTS: In high-risk cohorts, leukocyte counts demonstrated significant differences at T4 and T5 in Group 1, and at T4 in Group 2. Platelet counts were preserved significantly better at T4 and T5 in both groups (p < 0.05 versus control). Serum IL-2 and C3a levels were significantly lower at T3, T4 and T5 in Group 1, and T4 and T5 in Group 2 (p < 0.05). Postoperative bleeding, respiratory support time and incidence of atrial fibrillation were lower in the study groups versus control. Cell counts on filter mesh and heparin-coated fibers/ circuits were significantly higher in the high-risk cohorts versus uncoated fibers. Phagocytic capacity increased on filter mesh, especially in high-risk specimens. SEM evaluation demonstrated better preserved coated circuits. CONCLUSION: Leukofiltration and coating reduced platelet adhesion, protein adsorption, atrial fibrillation and reduced heparinization acted via modulation of systemic inflammatory response in high-risk groups.
