Equine piroplasmosis is a tick-transmitted disease caused by Theileria equi or Babesia caballi leading to haemolytic anaemia. Imidocarb is an effective treatment of piroplasmosis, but adverse clinical signs, including colic and diarrhoea, from cholinesterase inhibition are associated with its use. Atropine is advocated for the treatment of cholinesterase inhibiting compounds. Atropine is known to have a prolonged inhibitory effect on gastrointestinal motility. Glycopyrrolate is an anticholinergic drug that has similar effects to atropine on gastrointestinal motility, but with decreased penetration of blood-brain and blood-aqueous barrier. This study was performed to assess the adverse clinical effects of a therapeutic dose of imidocarb, the effect of this dose on gastrointestinal motility, and on cholinesterase activity. The ability of atropine or glycopyrrolate to ameliorate imidocarb’s adverse clinical signs, and the effect of the combination of atropine and imidocarb or glycopyrrolate and imidocarb on gastrointestinal motility was evaluated. A blinded crossover trial was performed in 8 horses. All horses were administered saline (CON), imidocarb 2.4 mg/kg im and saline iv (IMI), imidocarb 2.4mg/kg im and atropine 0.02 mg/kg iv (IMATROP) and imidocarb 2.4mg/kg im and glycopyrrolate 2.5 µg/kg iv (IMGLYCO), with a one week wash-out period between treatments. Butrylcholinesterase activity was measured in the CON and IMI group. Clinical signs, gastrointestinal motility and faecal production were assessed. Gastrointestinal motility was measured by abdominal auscultation and frequency of contractions in the duodenum, caecum and right dorsal colon visualized with transcutaneous abdominal ultrasound. Total faecal production, faecal dry matter, wet matter, faecal water percentage, frequency of defaecation and time to first defaecation was assessed. Abdominal pain and diarrhoea were observed in the IMI group. Borborygmi and frequency of intestinal contractions were not different in the IMI group compared to CON. Percentage water content, faecal production, faecal dry matter and frequency of defaecation were significantly increased in the IMI group. Butrylcholinesterase activity was not significantly decreased in the IMI group compared to CON. In the IMATROP group colic signs were observed, heart rate was significantly elevated and mydriasis was evident. Borborygmi and frequency of contractions in the right dorsal colon was significantly reduced in the IMATROP group. In the IMGLYCO group the incidence and severity of colic induced by imidocarb was reduced. Heart rate was significantly increased and borborygmi significantly decreased compared to CON. The effect of IMGLYCO on heart rate and borborygmi was significantly less than the effect of IMATROP. In the IMGLYCO group the frequency of ultrasound visualised intestinal contractions and faecal variables were not different from CON. Therapeutic doses of imidocarb are associated with clinical signs of muscarinic stimulation including colic and diarrhoea, and enhanced faecal production. Clinical signs of cholinesterase inhibition can be present without significant depression in plasma cholinesterase activity. Atropine prevents diarrhoea and normalises faecal water percentage but is not effective in decreasing incidence of abdominal pain, and causes a prolonged inhibition of gastrointestinal motility, which might make this drug undesirable to use as a pre-treatment to imidocarb in clinically affected horses. Glycopyrrolate only partially reduces gastrointestinal motility and decreases adverse signs and thus its use as a pre-treatment to imidocarb is preferred. / Dissertation (MMedVet)--University of Pretoria, 2006. / Companion Animal Clinical Studies / unrestricted

No description available.

Although parasympathetic activity (PNS) is the primary driver and sympathetic activity (SNS) is a significant inhibitor of colonic propulsive activity, they are rarely measured, and hence, they almost play no role in diagnosing dysfunction or standard treatments for chronic conditions such as refractory constipation. We aimed to develop methodologies for the assessment of autonomic nervous system (ANS) activity, establish criteria for autonomic dysfunction, and study if stimulation of lumbar and sacral autonomic nerves using low-level laser therapy (LLLT) could affect the ANS and explore it as a potential treatment of autonomic dysfunction to restore colonic motility. By studying the active standing test and the table tilt test as a method to evoke activity in the ANS, we rejected LF power, SD1 and SD2 of Poincare plot, Pre-ejection-period (PEP), complex-correlation-measure (CCM) and detrended fluctuation analysis (DFA). Respiratory-Sinus-Arrhythmia (RSA), Root-Mean-Square-of-Successive-Differences (RMSSD) were selected for PNS activity, the Baevsky’s-Stress-Index (SI) was chosen for SNS activity, and SI/RSA and SI/RMSSD were introduced as a measure of autonomic balance. We explored high-resolution-colonic-manometry with concurrent electrocardiography to observe whether these parameters could be associated with ANS changes during colonic motor patterns. High-amplitude-propagating-pressure-waves were associated with a strong parasympathetic activity and decreased sympathetic activity. Comparing ANS reactivity of patients with severe motility disorders to controls in response to postural changes, we observed that most patients have low PNS and elevated SNS baseline activity and reactivity. This established a way to evaluate autonomic dysfunction in patients with colon motor disorders. A single session of LLLT using LED and laser light on the lumbar and sacral spine in 41 patients with chronic gastrointestinal motor dysfunction indicated that treatments with LED light followed by laser light significantly increased parasympathetic activity and decreased sympathetic nervous system activities. These results initiated a study into the effects of LLLT on restoring autonomic dysfunction in chronic refractory colonic motility disorders. / Thesis / Doctor of Philosophy (PhD)

Call number: LD2668 .T4 1964 C288 / Master of Science

Thesis (MMed)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: In all Assisted Reproductive Technologies (ART) procedures the semen sample is handled, processed, prepared and manipulated before use in the fertilization process. During these incubation times, the sperm cells are exposed to factors that may inflict damage to the sperm structure and DNA integrity, impair its functional abilities and subsequently lead to fertilization failure and poor ART outcome. Two of the very basic, but important factors that may have an impact on the sperm quality are time and temperature exposure. The primary objective of this study was to prospectively determine the effect of different incubation times and temperatures on motility and the DNA profile of the spermatozoa. Non-processed (n=36) and processed (n=33) semen samples were incubated for different time intervals (before: 20, 40, 60 minutes; after: 30, 60, 90 minutes) and at different temperatures (room temperature [RT] and 37°C). After incubation, sperm parameters were assessed, the CMA3 assay was applied to determine chromatin maturity and compaction and the TUNEL assay to assess the level of DNA fragmentation. The results showed that in the non-processed group, incubation led to a time-dependent, significant decline in the motility. The highest motility was seen at 20 minutes (37°C) and motility declined in a time-dependent manner. Incubation time and temperature did not affect the CMA3 and TUNEL values. Incubation of the processed sample led to a significant time-dependent decrease in the motility; 90 minutes (RT) had the lowest motility. The CMA3 and TUNEL values between the different incubation groups did not differ significantly. The secondary objective was to retrospectively investigate the effect of sperm incubation time after preparation on ART outcome. A total of 901 patient ART cycles (January 2010- December 2012) were included. Fertilization rates, embryo quality and pregnancy rates were examined. The results showed that the sperm incubation time before insemination between in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) differed significantly and the incubation time had a significant negative effect on the fertilization rates in IVF, but not in ICSI. Longer incubation times led to an unexpected significant improvement in the quality of day 2 embryos and were significantly associated with pregnancy failure in IVF and ICSI. These combined findings suggest that non-processed semen samples can be incubated at RT or 37°C, but for no longer than 40 minutes and, for IVF, processed samples should not be incubated for longer than 60 minutes at RT or 37°C. The ICSI sample should not be incubated for more than 60 minutes although longer incubation times do not seem to influence the results for IVF. It can therefore also be concluded that sperm incubation time before insemination should be closely monitored, especially in IVF cycles. / AFRIKAANSE OPSOMMING: In kunsmatige voortplantingstegnieke (ART) word die semen-monster geprosesseer, voorberei en gemanipuleer voordat dit vir die bevrugtingsproses gebruik word. Terwyl die monster geïnkubeer word, word die spermselle blootgestel aan verskeie faktore wat die struktuur van die sperm, die DNS integriteit en die sperm se funksionele vermoë negatief kan beïnvloed. Dit kan lei tot swak bevrugting, embriokwaliteit en swangerskapsyfers. Twee basiese, maar belangrike, faktore wat die spermkwaliteit negatief kan beinvloed is die duur van inkubasie en die temperatuur waarby die spermselle geïnkubeer word. Die primêre doel van die huidige studie was om prospektief te ondersoek wat die effek van verskillende inkubasietye en temperature op die motiliteit en DNA profiel van die sperm het. Monsters is voor en na spermvoorbereiding vir verskillende tydsintervalle (voor: 20, 40, 60 minute; na: 30, 60, 90 minute) en verskillende temperature (kamertemperatuur [KT] en 37°C) geïnkubeer. Na elke inkubasie is ’n spermanalise, ’n CMA3- en ’n TUNEL toets gedoen. Die CMA3 toets bepaal die chromatienmaturiteit en -kompaksie en die TUNEL toets vir die vlak van DNS fragmentasie. Die resultate het getoon dat daar in die voor voorbereiding groep ’n beduidende verskil in motiliteit tussen die verskillende inkubasiegroepe was. Die hoogste motiliteit is in die 20 minute/37°C groep gevind. Die motiliteit het oor tyd afgeneem. Die tyd en temperatuur van inkubasie het nie ’n beduidende effek op die CMA3 en TUNEL uitslae gehad nie. Inkubasie nadat die semen voorberei was het weereens tot ’n beduidende verskil in motilieit tussen die groepe gelei. Die laagste motiliteit is waargeneem by 90 minute/KT. Geen beduidende verskil is tussen die inkubasiegroepe vir CMA3 en TUNEL gevind nie. Die sekondêre doel van die studie was om retrospektief te ondersoek wat die effek van sperminkubasietyd na spermvoorbereiding op die bevrugting, embriokwaliteit en swangerskapsyfers is. 901 pasiëntsiklusse is in die studie ingesluit (Januarie 2010 tot Desember 2012). Die resultate het aangedui dat die inkubasietye van die intrasitoplasmatiese inspuiting (ICSI) en in vitro bevrugting (IVB) beduidend van mekaar verskil het. Langer inkubasietye het ’n beduidende negatiewe effek op die bevrugtinguitslae van IVB siklusse gehad, maar geen effek op ICSI siklusse gehad nie. Langer inkubasietye het ook tot ’n onverwagte verhoging in die kwaliteit van dag 2 embrios gelei en was verder beduidend geassosieer met negatiewe swangerskapuitkoms. Hierdie gesamentlike bevindinge dui aan dat semenmonsters voor voorbereiding by KT of 37°C geïnkubeer kan word, maar nie vir langer as 40 minute nie. Na semenvoorbereiding, behoort die IVB semenmonster vir nie langer as 60 minute voor inseminasie geïnkubeer te word nie (KT of 37°C). Die ICSI semenmonster moet verkieslik binne 60 minute na voorbereiding gebruik word, maar dit wil voorkom asof die tyd hier nie so ’n groot rol speel nie. Daar kan verder afgelei word dat sperminkubasietye voor die gebruik vir inseminasie baie goed gemonitor moet word – veral in IVB siklusse.

published_or_final_version / abstract / Medical Sciences / Master / Master of Medical Sciences

No description available.

No description available.

The aim of this dissertation is to develop theoretical models for the motion of rigid and flexible particles through very tight spaces. The geometries of conduits which will be investigated are cylindrical tubes, parallel plane walls and rectangular channels. This work is motivated by an interest in the flow and deformation of single red blood cells in very narrow capillaries, in spleen and in bone marrow. Mammalian red cells are highly flexible, but their deformations satisfy two significant constraints. They must deform at constant volume, because the contents of the cell are incompressible, and also at nearly constant surface area, because the red cell membrane strongly resists dilation. Consequently, there exists a minimal tube diameter below which passage of intact cells is not possible. A cell in a tube with this diameter has its critical shape: a cylinder with hemispherical ends. The motion of red cells is analysed using lubrication theory. When the tube diameter is slightly larger than the minimal value, the cell shape is close to its shape in the critical case. However, the rear end of the cell becomes flattened and then concave with a relatively small further increase in the diameter. The changes in cell shape and the resulting rheological parameters are analysed using matched asymptotic expansions for the high-velocity limit and using numerical solutions. A rapid decrease in the apparent viscosity of red cell suspensions with increasing tube diameter is predicted over the range of diameters considered. The red cell velocity is found to exceed the mean bulk velocity by an amount which increases with increasing tube diameter. The same type of analysis is applied to the flow and deformation of red blood cells between two parallel plates with near-minimal spacings. First, the critical shape of the particle and the minimum gap width are determined using calculus of variations. In this case, it is a disk with a rounded edge. The flow in the plasma layers between the cell and the plates is described using lubrication theory. Approximate solutions can be obtained using a locally two-dimensional analysis at each point of the rim of the cell. Cell shapes, pressure distributions, membrane stresses and particle velocities are deduced as functions of geometrical parameters. One significant finding is that the gap width between the cell and the wall decreases with distance from the axis of symmetry parallel to the flow direction. The red cell velocity may be smaller or larger than the mean fluid velocity far from the cell, depending on the spacing of the plates, with equality when the width of the red cell is about ninety percent of the spacing between plates. The same procedure is also applied to rectangular channels.

The complex interaction between the central nervous system, the enteric nervous system and local and endocrine hormones enables drugs affecting gastrointestinal motility to produce their effects through multiple sites and mechanisms of action. Opiates are one class of drugs which can have dramatic effects on gastrointestinal function and the mechanisms for these actions have been the subject of intense study in recent years. These changes in motility have assumed increased importance following the discovery of several endogenous opioid peptides. In the present studies, centrally-administered morphine was more potent than peripherally-administered morphine at inhibiting intestinal propulsion and gastric emptying in rats. Direct measurement of intestinal motility revealed that the antipropulsive effects of morphine were due to an inhibition of intestinal contractions. The opioid peptide, β-endorphin, and a stabilized enkephalin analog, [D-Ala², Met⁵] enkephalinamide, also inhibited intestinal propulsion only after central administration. These effects were not blocked by a peripherally selective opioid receptor antagonist, diallylnormorphinium. These data indicated that there is an opioid sensitive mechanism in the brain of rats that, when activated, can inhibit intestinal motility. Physiological activation, by electroconvulsive shock or inescapable footshock, or pharamcological activation by kyotorphin (Tyr-Arg) treatment, did not affect gastrointestinal motility but did produce naloxone-reversible analgesia. These data indicate that the opioid mechanisms mediating analgesia and inhibition of intestinal motility are independent and may be a function of different receptor systems. Several opioid receptor selective agonists were used to determine the specific receptors mediating the analgesic and motility effects of centrally-administered opioids. Mu selective agonists produced analgesia and inhibition of intestinal transit, while delta receptor agonists produced analgesia only. Kappa agonists did not produce analgesia or an inhibition of intestinal motility. Mu receptors mediate the analgesic and intestinal motility effects of exogenously administered opioids, while delta receptors can mediate analgesia without altering gut motility. It appears then, that electroconvulsive shock, inescapable footshock and kyotorphin may produce their analgesic effects by releasing enkephalins, which are delta selective agonists. This accounts for the failure of these treatments to alter gastrointestinal motility while still producing the analgesic effects reported here.