Retrobulbar and peribulbar regional techniques in cats: a preliminary study in cadavers

ObjectiveTo compare injectate distribution and potential complications of retrobulbar and peribulbar injections in cat cadavers.Study designProspective randomized masked study.AnimalsTen cat cadavers (20 eyes).MethodsA dorsomedial retrobulbar injection (RB) of 1 mL of 0.5% bupivacaine and iopamidol (1:1) was performed in seven eyes. A dorsomedial peribulbar injection (PB‐1) of 4 mL of the same injectate was performed in seven eyes, and two peribulbar injections (PB‐2) of the same injectate, divided equally between the dorsomedial and ventrolateral regions (2 mL each) were performed in six eyes. Intraocular pressure (IOP) was measured before, immediately and 15 minutes after injection. Cadavers underwent computed tomography before and following injections. A radiologist scored injectate distribution within the intraconal space (none, moderate, or large) and around the optic nerve (degrees). An injection was defined as likely to provide adequate regional anesthesia if the volume of distribution of intraconal injectate was ‘large’ and it contacted over 270° of the optic nerve circumference.ResultsThe success rate (95% confidence interval) of RB, PB‐1, and PB‐2 injections was 71% (29.0–96.3%), 86% (42.1–99.6%), and 67% (22.3–95.7%), respectively. With all three techniques, IOP increased significantly after injection, but returned to baseline by 15 minutes following RB injection. No intraocular, intravascular, intrathecal, or intraneural injectate was observed.Conclusion and clinical relevanceThe single‐peribulbar injection technique may be superior to retrobulbar or double‐peribulbar injections, however, all techniques require further studies in live cats to determine safety and efficacy prior to clinical use.     

Thermal stability of genistein and daidzein and its effect on their antioxidant activity

Soy isoflavones, present in many processed soy foods, are known for their phytoestrogenic and antioxidant activities. The aim of this work was to study the kinetics of genistein and daidzein degradation at elevated temperatures and to follow changes in their antioxidant activity. Daidzein and genistein in model solutions (pH 7 and 9) were thermally treated at 120 degrees C or incubated at 70, 80, and 90 degrees C. Isoflavone degradation was observed at all temperatures, with apparent first-order kinetics at 70-90 degrees C, and E(a) = 8.4 and 11.6 kcal/mol at pH 9, respectively. Microcalorimetric stability tests showed a similar pattern of degradation, however, with higher E(a) (genistein, 73.7 kcal/mol; daidzein, 34.1 kcal/mol) that may be attributed to the anaerobic conditions. The antioxidant activity of incubated isoflavone solutions, followed by the ABTS test, decreased rapidly at pH 9 for genistein, whereas only moderate reduction was observed for daidzein (pH 7 and 9) or genistein at pH 7. This may indicate different degradation mechanisms for genistein and daidzein.     

Intratesticular and incisional line infiltration with ropivacaine for castration in medetomidine–butorphanol–midazolam sedated dogs

Objective

To evaluate whether intratesticular and incisional ropivacaine infiltration produces sufficient intra- and postoperative analgesia for castrating dogs under sedation.

Plasma bupivacaine concentrations following orbital injections in cats

Objective

To determine plasma bupivacaine concentrations after retrobulbar or peribulbar injection of bupivacaine in cats.

Determination of the minimum anesthetic concentration of sevoflurane in thick-billed parrots (Rhynchopsitta pachyrhyncha)

Objective-To determine the minimum anesthetic concentration (MAC) of sevoflurane in thick-billed parrots (Rhynchopsitta pachyrhyncha) and compare MAC obtained via mechanical and electrical stimulation. Animals-15 healthy thick-billed parrots. Procedures-Anesthesia was induced in each parrot by administration of sevoflurane in oxygen. An end-tidal sevoflurane concentration of 2.5% was established in the first bird. Fifteen minutes was allowed for equilibration. Then, 2 types of noxious stimulation (mechanical and electrical) were applied; stimuli were separated by 15 minutes. Responses to stimuli were graded as positive or negative. For a positive or negative response to a stimulus, the target end-tidal sevoflurane concentration of the subsequent bird was increased or decreased by 10%, respectively. The MAC was calculated as the mean end-tidal sevoflurane concentration during crossover events, defined as instances in which independent pairs of birds evaluated in succession had opposite responses. A quantal method was used to determine sevoflurane MAC. Physiologic variables and arterial blood gas values were also measured. Results-Via quantal analysis, mean sevoflurane MAC in thick-billed parrots determined with mechanical stimulation was 2.35% (90% fiducial interval, 1.32% to 2.66%), which differed significantly from the mean sevoflurane MAC determined with electrical stimulation, which was 4.24% (90% fiducial interval, 3.61% to 8.71%). Conclusions and Clinical Relevance-Sevoflurane MAC in thick-billed parrots determined by mechanical stimulation was similar to values determined in chickens and mammals. Sevoflurane MAC determined by electrical stimulation was significantly higher, which suggested that the 2 types of stimulation did not induce similar results in thick-billed parrots.     

Population Dynamics of Fusarium Oxysporum f. Sp. Radicis-lycopersici in Relation to the Onset of Fusarium Crown and Root Rot of Tomato

Fusarium oxysporum f. sp. radicis-lycopersici the causal agent of crown and root rot in tomato comprises two overlapping separate phases: monocyclic and polycyclic. Oversummering inoculum is the source of primary infection (the monocyclic phase) and the spread from plant to plant via root-to-root contact is the source of the secondary infection (the polycyclic phase). In the present work, relationships between initial inoculum density, population dynamics of the pathogen in the root zone of diseased plants, and disease onset were studied. For the monocyclic phase, 55.1% of the variance of disease onset was attributed to the rate of pathogen proliferation in the root zone of plants, and only 12.8% of the variance was attributed to the amount of initial inoculum density. For the polycyclic phase, disease onset was not related to either initial inoculum density or the rate of pathogen proliferation in the root zone. At disease onset, the inoculum density of the pathogen in the root zone of plants infected from oversummering inoculum reached an average of 4.08 log cfu g soil^–1. The inoculum density of the pathogen in the root zone of plants infected by their diseased neighbors was 3.23 log cfu g soil^–1. A large variation in pathogen proliferation rate in the root zone was found among individual plants, suggesting that differences in the level of soil suppressiveness may occur not only between fields, but even in the same field over short distances.     

Use of cystoscopic-guided laser ablation for treatment of intramural ureteral ectopia in male dogs: four cases (2006-2007)

OBJECTIVE: To describe and evaluate the outcome of cystoscopic-guided laser ablation of intramural ureteral ectopia in male dogs. DESIGN: Retrospective case series. ANIMALS: 4 incontinent male dogs with intramural ureteral ectopia. PROCEDURES: Intramural ectopic ureters were diagnosed via preoperative computed tomography-IV urography and subsequent cystoscopy. Transurethral cystoscopic-guided laser ablation (diode laser [n = 3 dogs] and holmium:yttrium aluminum garnet laser [1]) was performed to proximally relocate the ectopic ureteral orifice to the urinary bladder. Fluoroscopy was used during the procedures to confirm that the ureteral tract was intramural and the ureteral orifice was intravesicular after the procedure. In 1 dog with bilateral ureteral ectopia, staged laser ablation was performed at 6-week intervals because of difficulty viewing the second ureter on the first attempt. All ureteral orifices were initially located in the middle to proximal portion of the prostatic portion of the urethra. Six weeks after surgery, imaging was repeated in 3 of 4 dogs. RESULTS: Postoperative dysuria or hematuria did not develop. All dogs were immediately continent after laser treatment and remained so at a median follow-up period of 18 months (range, 15 to 20 months) without medical management. Conclusions and CLINICAL RELEVANCE: Ureteral ectopia can cause urinary incontinence in male dogs and is usually associated with other urinary tract abnormalities. Cystoscopic-guided laser ablation provided an effective and minimally invasive alternative to surgical management of intramural ureteral ectopia.