The cardiorespiratory and anesthetic effects of clinical and supraclinical doses of alfaxalone in cats

ObjectiveTo determine the cardiorespiratory and anesthetic effects of 0, 5, 15, and 50 mg kg^?1 intravenous (IV) alfaxalone in hydroxypropyl beta cyclodextrin (Alfaxan; Jurox Pty Ltd, Rutherford, NSW, Australia) in cats.Study designFour treatments of alfaxalone were administered in sequential order.AnimalsEight healthy adult cats (four male; four female) weighing between 3.71 and 5.91 kg.MethodsCats were instrumented for hemodynamic measurements. Four (0, 5, 15, and 50 mg kg^?1) IV doses of alfaxalone were administered over one minute, with a 3-hour washout period between doses 0, 5, and 15 mg kg^?1 on Day 0. The 50 mg kg^?1 treatment was administered 24 hours later. Measurements of heart rate, aortic systolic, mean, and diastolic blood pressures, pulmonary arterial and right atrial mean pressures, cardiac output, respiratory rate, tidal and minute volumes, and arterial blood pH and blood gases (PaO₂, PaCO₂) were performed at pre-determined intervals. Systemic vascular resistance and rate pressure product were calculated. The quality of induction, maintenance, and recovery from anesthesia and the response to noxious stimulation were categorically scored.ResultsAlfaxalone administration resulted in dose-dependent cardiorespiratory depression. Decreases in arterial blood pressure and increases in heart rate occurred at higher doses. Most variables returned to baseline by 15-30 minutes. Respiratory rate, minute volume, and PaO₂ decreased. Apnea was the most common side effect. Induction and maintenance quality were judged to be good to excellent at all doses and quality of recovery good to excellent at all but the 50 mg kg^?1 dose. The duration of anesthesia and unresponsiveness to noxious stimulation increased with dose. The administration of the 50 mg kg^?1 dose produced marked cardiorespiratory depression and apnea.Conclusions and clinical relevanceAlfaxalone produced dose-dependent anesthesia, cardiorespiratory depression and unresponsiveness to noxious stimulation in unpremedicated cats. Hypoventilation and apnea were the most common side effects.     

Is rhamnolipid biosurfactant useful in cadmium phytoextraction?

Purpose  

Successful chelant-assisted phytoextraction requires application of an eco-friendly metal-complexing agent which enhances metal uptake but does not pose a significant risk of off-site movement of metals. Rhamnolipid biosurfactant has been used to enhance cadmium (Cd) removal from contaminated soil by washing. It has a strong affinity for Cd compared to some other hazardous metals, suggesting that rhamnolipid could be useful in Cd phytoextraction. This study investigated the potential use of rhamnolipid to enhance Cd phytoextraction.     

Ultrasonographic and laboratory screening in clinically normal mature golden retriever dogs

Wellness and pre-anesthetic screening of blood and urine of geriatric companion animals are routinely recommended. In addition, there are occasional references to the use of imaging in clinically normal geriatric patients. However, the utility of wellness testing is not known, and there is limited information regarding the value of pre-anesthetic testing. Wellness testing, including complete blood cell count, biochemical profile, urinalysis, and abdominal ultrasound, was performed on 53 clinically normal, mature golden retriever dogs. Laboratory analysis revealed abnormalities in 54.7% (29/53) of the dogs. Abdominal ultrasound screening demonstrated abnormalities in 64.2% (34/53) of the dogs. As only a small number of dogs had follow-up diagnostic testing available, the significance of these abnormalities is unknown. Further study involving a larger cohort of animals and analysis of follow-up data is necessary to determine the utility of laboratory and imaging studies in clinically normal geriatric patients.     

Comparison of effects of dexamethasone and the leukotriene D4 receptor antagonist L-708,738 on lung function and airway cytologic findings in horses with recurrent airway obstruction

OBJECTIVE: To evaluate whether the leukotriene (LT) D4 receptor antagonist L-708,738 is therapeutically beneficial in treating horses with recurrent airway obstruction (heaves). ANIMALS: 12 adult horses with heaves and healthy lung lobes from 20 slaughtered horses. PROCEDURE: Lung lobes were used for smooth muscle tension and radioligand binding studies. Horses with heaves were given a placebo for 14 days and administered L-708,738 (n = 6; 2.5 mg/kg PO, q 12 h) or dexamethasone (6; 0.04 mg/kg, IV, q 24 h) from days 14 to 28. Pulmonary function was measured weekly for 36 days, and bronchoalveolar cells were collected on days 0,14, and 29 for cytologic examination. RESULTS: Nanomolar concentrations of L-708,738 were effective at antagonizing LTD4-induced bronchoconstriction and LTD4-receptor binding in lung lobes. Mean peak and trough L708,738 plasma concentrations during the treatment period were 1.54 and 0.28 microM, respectively. On days 21 and 29, lung mechanics were significantly improved in the dexamethasone-treated horses but not in the L-708,738-treated horses. Neither dexamethasone nor L-708,738 had a significant effect on cytologic findings. CONCLUSIONS AND CLINICAL RELEVANCE: L-708,738 was bioavailable after oral administration and sustained concentrations in plasma during the dosing period that exceeded in vitro efficacy values. However, airway function did not improve, suggesting that either drug concentrations in the lungs were subtherapeutic or that cysteinyl LT may not be important mediators of airway inflammation in heaves. Results provide the first evidence of cysteinyl LT1 receptors in airways of horses.     

Association between anal furunculosis and colitis in the dog: preliminary observations

Treatment of anal furunculosis in dogs is often unsatisfactory and may be associated with significant recurrence and complications. This may be compounded by the simultaneous presence of colitis in affected animals. Clinical signs associated with colitis and anal furunculosis may be similar, including faecal tenesmus, dyschezia and haematochezia. To examine the incidence of concurrent anal furunculosis and colitis, colonic biopsies were collected from 18 dogs referred for treatment of anal furunculosis. Nine dogs (50 per cent) had a histopathological diagnosis of colitis. Clinical signs more indicative of colitis than anal furunculosis (increased frequency of defecation, mucus in faeces and diarrhoea) were not observed more frequently in dogs with confirmed colitis compared with those with furunculosis alone. Therefore, while an association between colitis and anal furunculosis may exist, clinical signs alone cannot be used as an indicator of the presence of colitis in cases of anal furunculosis. The authors recommend that colonic biopsies should be undertaken in all dogs presented with anal furunculosis. Whether specific treatment of colitis in dogs with histopathological evidence of colitis improves the outcome of treatment for anal furunculosis awaits further study.     

Time and metamorphic petrology: calcite to aragonite experiments

Although the equilibrium phase relations of many mineral systems are generally well established, the rates of transformations, particularly in polycrystalline rocks, are not. The results of experiments on the calcite to aragonite transformation in polycrystalline marble are different from those for earlier experiments on powdered and single-crystal calcite. The transformation in the polycrystalline samples occurs by different mechanisms, with a different temperature dependence, and at a markedly slower rate. This work demonstrates the importance of kinetic studies on fully dense polycrystalline aggregates for understanding mineralogic phase changes in nature. Extrapolation of these results to geological time scales suggests that transformation of calcite to aragonite does not occur in the absence of volatiles at temperatures below 200 degrees C. Kinetic hindrance is likely to extend to higher temperatures in more complex transformations.     

Clinically overt infections with methicillin-resistant Staphylococcus aureus in animals in New Zealand: a pilot study

AIM: To describe clinically overt infections with methicillin resistant Staphylococcus aureus (MRSA) in animals in New Zealand, characterise clinical isolates, and track their sources. METHODS: MRSA isolates identified in 2005 and 2006 by a veterinary diagnostic laboratory were referred to Massey University for confirmation and characterisation. Clinical information was extracted from the laboratory records or obtained from referring clinicians. RESULTS: Seven MRSA isolates from animals and contact persons were characterised. All the isolates belonged to the British epidemic MRSA 15 strain (EMRSA-15). Three EMRSA-15 were isolated from post-operative infections in two dogs. An EMRSA-15 indistinguishable from the isolate recovered from one dog was isolated from the anterior nares of a healthy hospital staff member involved in the care of the animal, suggesting nosocomial transmission. Other EMRSA-15 isolates of uncertain clinical significance were isolated from the femoral head of a cat, and from a sample of cow's milk. AlleMRSA-15 isolates were resistant to ciprofloxacin, and four were resistant to erythromycin; the latter four isolates also exhibited inducible resistance to clindamycin. CONCLUSIONS: MRSA can cause clinically overt and difficult-to-treat infections in animals in New Zealand. The rapid emergence of EMRSA-15 as the dominant MRSA strain in humans has resulted in infection spill over to animals. CLINICAL RELEVANCE: Little is known about the incidence of clinically overt infections with MRSA in animals. The cases described here illustrate the complexities involved in the pharmacological management of EMRSA-15 infections, which is compounded by the universal resistance to beta-lactams, and by the strain's fluoroquinolone resistance and frequent inducible resistance to clindamycin. Such complexities indicate there is a need to develop specific empirical antimicrobial treatment strategies and antibiotic susceptibility testing protocols in countries where EMRSA-15 is dominant.     

Fluid resuscitation and the trauma patient.

Traumatic shock can result from one or more of the following: hypovolemia, increased capillary permeability and vasodilatation, impaired myocardial contractility or dysfunction, blood loss, and cardiovascular obstruction. Animals with traumatic injuries are less tolerant of sudden increases in hydrostatic pressure, which can exacerbate fluid leakage into damaged tissues and disrupt blood clots. Pain amplifies the shock response, and analgesic therapy is always recommended in the trauma patient. Therapy must be individualized and monitored closely.