Effect of common sedation agents on feline splenic size determined via ultrasonography.

AIMS: To evaluate the effect of IM administration of three sedative drugs, acepromazine, alfaxalone and dexmedetomidine, in combination with morphine, on the size of the feline spleen using ultrasonography. METHODS: Twenty-four client-owned cats undergoing elective de-sexing or minor procedures were recruited for a focused ultrasonographic examination of the spleen prior to and at 10, 20 and 30 minutes following administration of one of three randomly assigned IM sedation protocols: 0.05 mg/kg acepromazine (ACE group), 3 mg/kg alfaxalone (ALF group), or 10 µg/kg dexmedetomidine (DEX group), in combination with 0.5 mg/kg morphine. B-mode images of the spleen were collected and measured following a standardised protocol. Cardiorespiratory parameters and sedation score were also recorded. Mean thickness of the head, body and tail of the spleen for each group at 10, 20 and 30 minutes after drug administration was compared to baseline. RESULTS: Mean splenic thickness increased over time in the ACE group (thickness of body at T0 = 8.9 (SE 2.1) mm and at T30 = 10.5 (SE 2.0) mm; p = 0.001) and the ALF group (thickness of body at T0 = 8.8 (SE 1.0) mm and at T30 = 10.3 (SE 1.7) mm; p = 0.022) but not in the DEX group (thickness of body at T0 = 8.6 mm (1.2) and at T30 = 8.9 mm (0.6); p = 0.67). Mean arterial blood pressure in the DEX group was significantly higher than in the other groups (p = 0.002). Sedation scores in the DEX group were consistently high for the entire period. However, the sedation score in the ACE group increased over 30 minutes (p = 0.007). Sedation score in the ALF group was highest at 10 minutes but gradually decreased over the following 20 minutes (p = 0.003). CONCLUSIONS: Sedation with IM dexmedetomidine and morphine did not change splenic size, whereas acepromazine or alfaxalone and morphine increased it regardless of the degree of sedation. CLINICAL RELEVANCE: Where splenomegaly is identified in a cat sedated with acepromazine or alfaxalone, the effects of the sedation protocol could be considered as a possible cause.

Indicators of dehydration in healthy 4- to 5-day-old dairy calves deprived of feed and water for 24 hours.

Our objective was to identify practical indicators of calf dehydration that could be used in an industry context. Eleven healthy 4-d-old commercial dairy calves were fed 2 L of mixed colostrum, then deprived of food and water for 24 h. Total body water was determined in the fed state using the deuterium dilution method. Body weight, along with a range of behavioral and physiological variables, was recorded 1 h after feeding, then at 90-min intervals through to 24 h. Blood samples were collected at every second sampling to assess changes in plasma hemoglobin, hematocrit, and osmolality. Linear mixed-effects models were used to explore associations between hydration status (% body water) and outcome variables. All calves remained bright and alert with good suckling reflexes throughout the 24-h period. After 24 h, total body water had decreased by an average of 8.4% (standard error 1.18), consistent with mild to moderate dehydration. Skin tent return time, capillary refill time, and detectable enophthalmos were associated with hydration status. Calves with skin tent return times of 3 s or longer were 4.4 percentage points less hydrated than those with return times of less than 3 s. Similarly, a capillary refill time of 3 s or longer was associated with a 4.3 percentage point reduction in hydration compared with refill times of less than 3 s. Calves with detectable enophthalmos (≥1 mm) were 3.5 percentage points less hydrated than those without enophthalmos. The skin tent, capillary refill, and enophthalmos tests are all relatively simple to perform and, although requiring the calf to be briefly restrained, can easily be performed by a single operator. The outcome of these tests was relatively consistent, in that calves above the threshold in any test were 3.5 to 4.5% less hydrated than calves below the threshold. As such, these tests may be of practical utility to identify calves with mild to moderate dehydration in an industry setting.

Effect of insulation with bubble wrap and an absorbent pad on heat loss in anaesthetised cats.

Aims: To evaluate the efficacy of insulating the limbs and thorax of cats with a combination of bubble wrap and an absorbent, plastic-lined pad in reducing heat loss during ovariohysterectomy. Methods: A preliminary study was performed to compare heat loss of 1 L bags of Hartmann's solution heated to 38°C which were either wrapped in two layers of bubble wrap and an absorbent pad (n = 6) or were unwrapped (n = 6). Bags were allowed to cool in a temperature-controlled room and the temperature of the bags was measured every 10 minutes for 60 minutes. The clinical study, included 16 intact female cats undergoing ovariohysterectomy. The cats were premedicated with I/M morphine and either medetomidine or dexmedetomidine, and anaesthesia was induced with I/V propofol and maintained with isoflurane in 100% oxygen. Cats were randomly assigned to either the treatment group (n = 8) whose limbs and thorax wrapped with two layers of bubble wrap and an absorbent pad immediately after induction, or the control group (n = 8) which were unwrapped. Body temperature (measured with an oesophageal temperature probe), heart rate, respiratory rate, mean arterial pressure and partial pressure of end-tidal CO2 were recorded immediately after induction (T start), before surgery started (T surgery), and at the end of isoflurane administration (T end). The times from T end to extubation, from T end to when the cat could maintain sternal recumbency and from T end to when the cat was able to stand, were also recorded. Results: In the preliminary study of heat loss by fluid bags, the mean temperature at 60 minutes was higher in wrapped bags (35.4 (SD 0.2)°C) compared to unwrapped bags (33.0 (SD 0.3)°C; p < 0.01). For cats undergoing ovariohysterectomy, mean body temperature of wrapped cats was higher than that of unwrapped cats both at T surgery (36.0 (SE 0.3) vs. 34.5 (SE 0.3)°C; p = 0.001) and at T end (37.2 (SE 0.5) vs. 36.0 (SE 0.5)°C; p = 0.01). Wrapped cats regained the ability to stand more rapidly that unwrapped cats (26.4 (SE 5.8) vs. 47.0 (SE 5.8) minutes p = 0.01). Conclusions: Wrapping the limbs and thorax of cats undergoing ovariohysterectomy in a combination of bubble wrap and absorbent pads reduced heat loss, which in turn improved recovery time from general anaesthesia. Clinical relevance: This inexpensive and practical method may reduce perioperative hypothermia, in cats undergoing abdominal surgery.

Analgesic efficacy of articaine hydrochloride for velvet antler removal in red deer (Cervus elaphus) and analysis of drug residues in the harvested velvet antlers.

AIMS: To investigate the analgesic efficacy of articaine hydrochloride for antler removal in red deer (Cervus elaphus) following S/C administration as a ring block, and to quantify the residue concentrations of articaine compared to lignocaine in the harvested antlers. METHODS: Articaine hydrochloride (40 mg/mL) was administered to 10 male red deer as a ring block around the base of each antler at 1 mL/cm of pedicle circumference. Analgesia was evaluated by determining the response to a saw cut test every 1-minute, until no response was observed. Behaviour during and following removal of antlers was also recorded. Twenty commercially harvested velvet antlers were also collected following S/C administration of 2% lignocaine hydrochloride. A liquid chromatography-mass spectrometry (LC-MS) method for quantification of residues of articaine and lignocaine in velvet antlers was developed and validated. RESULTS: In red deer administered 4% articaine hydrochloride as a ring block, the median interval to analgesia was 4 (min 3, max 5) minutes and no deer showed withdrawal responses during antler removal. There were no signs of toxicity or adverse effects up to 2 hours after administration. The sample preparation method developed for the LC-MS was simple and had acceptable extraction recoveries of articaine and lignocaine from the velvet antlers. The lower limits of quantification of lignocaine and articaine were 5 and 50 ng/g, respectively. Mean concentrations of articaine in antlers following ring block with 4% articaine hydrochloride were 1.50 (SD 1.09) mg/kg, and of lignocaine following ring block with 2% lignocaine hydrochloride were 0.66 (SD 0.71) mg/kg. CONCLUSIONS AND CLINICAL RELEVANCE: A ring block with 4% articaine hydrochloride at a dose of 1 mL/cm of pedicle circumference provided effective analgesia for velvet antler removal in red deer. The LC-MS method developed and validated to quantify articaine and lignocaine was simple and sensitive. Based on these results, articaine hydrochloride appears to be an effective alternative to lignocaine hydrochloride for velvet antler removal. However, further studies to evaluate the safety and residue concentrations of articaine and articainic acid are required before it can be recommended for use in deer.Abbreviations: DMA: 2,6-dimethylaniline; LC-MS: Liquid chromatography-mass spectrometry; MEGX: Monoethylglycinexylidide; MRL: Maximum residue level.

Characterization of novel Mycobacterium tuberculosis pncA gene mutations in clinical isolates from the Ukraine.

Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis cases in the Ukraine are increasing. Pyrazinamide (PZA) is critically important for first- and second-line tuberculosis (TB) treatment regimes. However, PZA drug susceptibility testing is time consuming and technically challenging. The present study utilized Next-generation sequencing (NGS) to identify mutations in the pncA gene from clinical isolates and to assess the prevalence of pncA gene mutations in MDR/XDR-TB patients. Clinical isolates were inactivated in molecular transport media and shipped from Kharkiv, Ukraine, to San Antonio, TX. Whole-genome and targeted pncA gene sequencing was carried out using Illumina MiSeq instrumentation. Mutations were noted in 67 of 91 (74%) clinical isolates comprising substitutions, insertions, and deletions in the pncA coding and upstream promoter region. Of 45 mutation types, there were 11 novel, i.e., to date unknown, pncA mutations identified of which 3 were confirmed PZA resistant. Seven isolates contained mixed base mutations, whereas 4 harbored doubled mutations. Data reported here further support use of NGS for pncA gene characterization and may contribute in significant fashion to PZA therapy, especially in MDR- and XDR-TB patients.

Next-Generation Sequencing for Characterizing Drug Resistance-Conferring Mycobacterium tuberculosis Genes from Clinical Isolates in the Ukraine.

The Ukraine ranks among the top 20 countries with the highest number of multidrug-resistant (MDR) and extensively drug resistant (XDR) Mycobacterium tuberculosis cases in the world. However, little is known of the genetic diversity, i.e., resistance signatures, in clinical isolates from this region. We analyzed seven of most prevalent MDR/XDR antibiotic resistance-conferring genes from clinical isolates (n = 75) collected from geographically diverse Ukrainian oblasts and the southern Crimean peninsula. Genomic analysis revealed that 6 (8%) were sensitive, 3 (4%) were resistant to at least one antibiotic but were not MDR, 40 (53%) were MDR, and 26 (35%) were XDR. The majority of isolates (81%) were of the Beijing-like lineage. This is the first study to use next-generation sequencing (NGS) of clinical isolates from the Ukraine to characterize mutations in genes conferring M. tuberculosis drug resistance. Several isolates harbored drug resistance signatures that have not been observed in other countries with high-burden tuberculosis. Most notably, the absence of inhA gene promoter mutations, a diversity of mutation types in the rpoB resistance-determining region, and detection of heteroresistance provide a broader understanding of MDR/XDR from this area of the world.

Pharmacokinetics of articaine hydrochloride and its metabolite articainic acid after subcutaneous administration in red deer (Cervus elaphus).

AIM: To develop and validate a simple and sensitive method using liquid chromatography-mass spectrometry (LC-MS) for quantification of articaine, and its major metabolite articainic acid, in plasma of red deer (Cervus elaphus), and to investigate the pharmacokinetics of articaine hydrochloride and articainic acid in red deer following S/C administration of articaine hydrochloride as a complete ring block around the antler pedicle. METHODS: The LC-MS method was validated by determining linearity, sensitivity, recovery, carry-over and repeatability. Articaine hydrochloride (40 mg/mL) was administered S/C to six healthy male red deer, at a dose of 1 mL/cm of pedicle circumference, as a complete ring block around the base of each antler. Blood samples were collected at various times over the following 12 hours. Concentrations in plasma of articaine and articainic acid were quantified using the validated LC-MS method. Pharmacokinetic parameters of articaine and articainic acid were estimated using non-compartmental analysis. RESULTS: Calibration curves were linear for both articaine and articainic acid. The limits of quantifications for articaine and articainic acid were 5 and 10 ng/mL, respectively. Extraction recoveries were >72% for articaine and >68% for articainic acid. After S/C administration as a ring block around the base of each antler, mean maximum concentrations in plasma (Cmax) of articaine were 1,013.9 (SD 510.1) ng/mL, detected at 0.17 (SD 0.00) hours, and the Cmax for articainic acid was 762.6 (SD 95.4) ng/mL at 0.50 (SD 0.00) hours. The elimination half-lives of articaine hydrochloride and articainic acid were 1.12 (SD 0.17) and 0.90 (SD 0.07) hours, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The LC-MS method used for the quantification of articaine and its metabolite articainic acid in the plasma of red deer was simple, accurate and sensitive. Articaine hydrochloride was rapidly absorbed, hydrolysed to its inactive metabolite articainic acid, and eliminated following S/C administration as a ring block in red deer. These favourable pharmacokinetic properties suggest that articaine hydrochloride should be tested for efficacy as a local anaesthetic in red deer for removal of velvet antlers. Further studies to evaluate the safety and residues of articaine hydrochloride and articainic acid are required before articaine can be recommended for use as a local anaesthetic for this purpose.

A survey of dog and cat anaesthesia in a sample of veterinary practices in New Zealand.

AIMS: To survey current anaesthesia practices for dogs and cats in small and mixed animal practices in New Zealand in order to improve anaesthesia education. METHODS: A questionnaire was sent to 440 small and mixed animal practices, including questions regarding the type of practice, preanaesthetic examination, anaesthetic drugs and management, anaesthetic machines, monitoring and topics of interest for continuing professional development. RESULTS: Responses were obtained from 113/440 (26%) practices, with 78 (69%) respondents from small and 35 (31%) from mixed animal practices. A preanaesthetic physical examination was carried out by >95% of respondents and premedication was usually given to dogs (112/113; 99%) and cats (95/113; 85%). Acepromazine was the preferred sedative for dogs and cats, with morphine or buprenorphine. Propofol and alfaxalone were the preferred induction agents, and isoflurane was preferred for maintenance in both dogs and cats. A venous catheter was usually placed for anaesthesia in dogs (59/113; 52%), but less so in cats (39/113; 35%). Perioperative fluid was administered at 10 mL/kg/hour by 62/110 (56%) respondents. Intubation was usually used for anaesthesia in dogs (111/112; 99%), and cats (87/112; 78%). Almost 40% of respondents usually administered supplementary oxygen if patients were not intubated. Local analgesia was used by 69/111 (88%) respondents sometimes or always if applicable. Morphine or buprenorphine, and meloxicam were common choices for post-operative analgesia after neuter surgery in dogs and cats. A semiclosed (non-rebreathing) system was used in animals weighing <10 kg, and a Mapleson E or F non-rebreathing circuit was used by 66/109 (61%) practices. Only 15/111 (14%) practices had a ventilator in their practice. A dedicated anaesthetist was usually used by 104/113 (92%) practices, and apnoea alarms, pulse oximeters, thermometers and oesophageal stethoscopes were the main monitoring devices available in practices. Loco-regional block, pain management, and anaesthetic drugs were the main topics of interest for continuing education. CONCLUSIONS AND CLINICAL RELEVANCE: Responses by the veterinarians taking part in this survey indicated that they had a reasonably good standard of anaesthetic practice. A physical examination was carried out preanaesthesia, and premedication including analgesia was routinely administered to most patients. A dedicated anaesthetist usually monitored patients and most respondents reported they had access to basic anaesthetic monitoring equipment. Areas where changes could lead to improved anaesthetic practice were increased use of I/V catheterisation, endotracheal intubation, and supplementary oxygen, and reduced I/V fluid rates.

Ability of pulse wave transit time to detect changes in stroke volume and to estimate cardiac output compared to thermodilution technique in isoflurane-anaesthetised dogs.

OBJECTIVE: To evaluate the ability of pulse wave transit time (PWTT) to detect changes in stroke volume (SV) and to estimate cardiac output (CO) compared with the thermodilution technique in isoflurane-anaesthetized dogs. STUDY DESIGN: Prospective, experimental study. ANIMALS: Eight adult laboratory dogs. METHODS: The dogs were anaesthetized with isoflurane and mechanically ventilated. Reference CO (TDCO) was measured via a pulmonary artery catheter using the thermodilution technique and reference SV (TDSV) was calculated. PWTT was calculated as the time from the electrocardiogram R-wave peak to the rise point of the pulse oximeter wave. Estimated CO (esCO) was derived from PWTT after calibration with arterial pulse pressure (both non-invasive and invasive methods) and TDCO. Haemodynamic changes were induced by administration of phenylephrine (vasoconstriction), high isoflurane (vasodilatation and negative inotropy) and dobutamine (vasodilatation and positive inotropy). Trending between percentage change in PWTT and TDSV was assessed using concordance analysis and receiver operator characteristic (ROC) curve. The agreement between esCO and TDCO was evaluated using the Bland-Altman method. RESULTS: The direction of percentage change between consecutive PWTT and the corresponding TDSV showed a concordance rate of 95%, with correlation coefficients of -0.86 (p<0.001). Area under the ROC curve for the change in PWTT to detect 15% change in TDSV was 0.91 (p<0.001). TDCO compared with esCO calibrated with invasive and non-invasive blood pressure showed a bias (precision of agreement) of 0.58 (1.54) and 0.57 (1.59) L minute-1 with a percentage error of ±61% and ±63%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: In isoflurane-anaesthetized dogs, PWTT showed a good trending ability to detect 15% changes in SV. This technique is easy to use, inexpensive, non-invasive and could become routine anaesthetic monitoring. However, the agreement between absolute esCO and TDCO was unacceptable.

Spatiotemporal analysis of spontaneous myogenic contractions in the urinary bladder of the rabbit: timing and patterns reflect reported electrophysiology.

The dynamics of propagating myogenic contractions in the wall of the resting ex vivo urinary bladder of the rabbit were characterized by spatiotemporal maps and related to cyclic variation in intravesical pressure (Pves). Patches of propagating contractions (PPCs) enlarged and involuted in near synchrony with peaks in Pves [mean 3.85 ± 0.3 cycles per minute (cpm)] and were preceded by regions of stretch. The maximum area of the bladder undergoing contraction (55.28 ± 2.65%) and the sizes of individual PPCs (42.61 ± 1.65 mm2) coincided with the peak in Pves PPCs originated and propagated within temporary patch domains (TPDs) and comprised groups of nearly synchronous cyclic propagating individual contractions (PICs). The TPDs were located principally along the vertical axis of the anterior surface of the bladder. The sites of origin of PICs within PPCs were inconsistent, consecutive contractions often propagating in opposite directions along linear maps of strain rate. Similar patterns of movement occurred in areas of the anterior bladder wall that had been stripped of mucosa. Pves varied cyclically with area of contraction and with the indices of aggregation of PPCs, indicating that they grew by peripheral enlargement and collision without annihilation. The synchronization of PICs within PPCs was sometimes lost, uncoordinated PICs then occurring irregularly (between 4 and 20 cpm) having little effect on Pves We postulate that the formation and involution of PPCs within a TPD resulted from cyclic variation in excitation that increased the incidence and distance over which component PICs propagated.

Evaluation of an indirect oscillometric blood pressure monitor in anaesthetised dogs at three different anatomical locations.

AIMS: To evaluate the agreement between invasive and non-invasive measurements of blood pressure (BP) using an oscillometer (PetTrust) at three different anatomical locations in anaesthetised dogs under different haemodynamic conditions. METHODS: Eight adult Greyhounds weighing 23.5-36.5 kg were anaesthetised with isoflurane and positioned in dorsal recumbency. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and mean arterial pressure (MAP) were measured invasively via a dorsal pedal artery and non-invasively using the oscillometer with cuffs placed above the carpus, above the tarsus and around the tail base. Phenylephrine was administered to induce vasoconstriction, dobutamine was used to increase cardiac output and increased end-tidal concentrations of isoflurane were used to induce vasodilation. Correlation between measurements was analysed by linear regression and agreement was analysed using Bland-Altman plots. RESULTS: Seventy two representative measurements were obtained. Mean differences (bias) between invasive and non-invasive measurements were <5 mmHg except for DAP measured on the tail, and SD (precision) were <15 mm Hg except for SAP measured at the pelvic limb. Correlation coefficients were >0.9 except for SAP on the pelvic limb and DAP on the tail. More than 50 and 80% of values measured using oscillometry lay within 10 and 20 mmHg, respectively, of values measured invasively except for SAP on the tail. SAP tended to be overestimated when measured non-invasively at low BP, and be underestimated at high BP. DAP was underestimated during low BP and overestimated during high BP. Hypotension (MAP <60 mmHg) was detected by the oscillometer with a sensitivity ≥83% and specificity ≥98% at all locations. CONCLUSIONS: This oscillometric device met the 2007 American College of Veterinary Internal Medicine guidelines for measurement of BP on the thoracic limb. There was good agreement between the oscillometer and invasive measurement of MAP at all locations. CLINICAL RELEVANCE: MAP is the driving pressure for tissue perfusion, thus MAP measurement is clinically essential. This oscillometric device yields reliable MAP measurements at three anatomical locations over a wide range of BP and can identify hypotension with high sensitivity and specificity.

Biological Variability in Serum Cortisol Concentration Post-adrenocorticotropic Hormone Stimulation in Healthy Dogs.

BACKGROUND: The ACTH stimulation has low sensitivity for the diagnosis of hypercortisolism possibly as a result of biological and analytical variability. HYPOTHESIS/OBJECTIVES: To report the components of biological and analytical variability in serum cortisol concentration post-ACTH stimulation ([cortisol]) in healthy dogs. ANIMALS: Fourteen healthy harrier hound dogs. METHODS: The data were extracted from a separate, prospective, randomized, double-blinded, controlled discovery study in which dogs treated with vehicle control and 4 different doses of cortisone acetate (CA) for 7 days had an ACTH stimulation test performed to confirm the dose-dependent effect of CA. The index of individuality (IoI), the critical difference between sequential measurements (CD ), and the number of measurements required to assess the homeostatic set point (HSP) of [cortisol] with confidence intervals (CI) of 90 and 95% were estimated. RESULTS: The IoI was equal to 1.1 and the CD was 3.3 µg/dL (92 nmol/L). The number of measurements required to assess the HSP of [cortisol] with CI of 90 and 95% were 3 and 15, respectively. Additionally, mean [cortisol] was higher in males than in females (13.3 ± 4 µg/dL [366 ± 114 nmol/L] vs. 11.5 ± 2.5 µg/dL [318 ± 65 nmol/L], respectively; P = .046). As expected, treatment with CA resulted in a dose-dependent suppression of [cortisol]. CONCLUSIONS AND CLINICAL IMPORTANCE: False-negative test results in hypercortisolism could occur when [cortisol] is outside of the individual's HSP and within the reference interval. The large CD emphasizes the importance of assessing clinically relevant parameters in the diagnosis and monitoring of HC.

Advanced spatiotemporal mapping methods give new insights into the coordination of contractile activity in the stomach of the rat.

We used spatiotemporal mapping of strain rate to determine the direction of propagation and amplitudes of the longitudinal and circumferential components of antrocorporal (AC) contractions and fundal contractions in the rat stomach maintained ex vivo and containing a volume of fluid that was within its normal functional capacity. In the region of the greater curvature the longitudinal and circular components of AC contractions propagated synchronously at right angles to the arciform geometric axis of the stomach. However, the configuration of AC contractions was U shaped, neither the circular nor the longitudinal component of contractions being evident in the upper proximal corpus. Similarly, in the distal upper antrum of some preparations, circumferential components propagated more rapidly than longitudinal components. Ongoing "high-frequency, low-amplitude myogenic contractions" were identified in the upper proximal gastric corpus and on the anterior and posterior wall of the fundus. The amplitudes of these contractions were modulated in the occluded stomach by low-frequency pressure waves that occurred spontaneously. Hence the characteristics of phasic contractions vary regionally in the antrum and corpus and a previously undescribed high-frequency contractile component was identified in the proximal corpus and fundus, the latter being modulated in synchrony with cyclic variation in intrafundal pressure in the occluded fundus.

Xpert(®) MTB/RIF detection of Mycobacterium tuberculosis from sputum collected in molecular transport medium.

BACKGROUND: The Xpert(®) MTB/RIF assay is widely used for Mycobacterium tuberculosis detection. However, specimen transport remains a challenge. PrimeStore Molecular Transport Medium(®) (PS-MTM) inactivates specimens and stabilizes DNA/RNA at ambient temperature for subsequent molecular detection. OBJECTIVE: To compare the detection of M. tuberculosis concentrations in PS-MTM using Xpert and real-time polymerase chain reaction (RT-PCR), and smear-positive sputum specimens collected using a flocked swab. METHODS: Dilutions of M. tuberculosis in PS-MTM and phosphate buffered saline (PBS) were analyzed using the Xpert assay and commercial RT-PCR. Smear-positive (1+ to 3+) sputum specimens (n = 17) were transferred by flocked swab into PS-MTM and PBS, and were compared to standard 1.0 ml sputum Xpert analysis. RESULTS: Using the Xpert assay, cycle threshold values from high M. tuberculosis concentrations in PS-MTM (>10(3) colony forming units [cfu]/ml) were increased compared to control. In contrast, M. tuberculosis samples containing <10(3) cfu/ml, i.e., low concentrations, suspended in PS-MTM resulted in detection down to 10 cfu/ml. Xpert detection efficiency in PS-MTM treated samples (63.2%) was improved compared to PBS controls (34.9%). Xpert detected M. tuberculosis in all sputum specimens collected by flocked swabs in PS-MTM, and correlated with routine Xpert detection. CONCLUSIONS: PS-MTM enhances M. tuberculosis detection at low concentrations of M. tuberculosis, and provides a simplified and efficient collection method for Xpert detection.

The Effect of the Canine ABCB1-1Δ Mutation on Sedation after Intravenous Administration of Acepromazine.

BACKGROUND: Dog breeds with the ABCB1-1Δ mutation have substantially truncated nonfunctional P-glycoprotein. Dogs homozygous for this mutation (mut/mut) are susceptible to the toxic adverse effects of ivermectin, loperamide, and vincristine. Anecdotal reports suggested ABCB1 mut/mut dogs showed increased depth and duration of acepromazine sedation. HYPOTHESIS/OBJECTIVES: That ABCB1 mut/mut dogs have increased depth and duration of sedation after acepromazine IV compared to normal dogs (nor/nor). ANIMALS: Twenty-nine rough-coated collies were divided into 3 groups of dogs based on their ABCB1 genotype: 10 mut/mut, 10 mut/nor, and 9 nor/nor. METHODS: Dogs were given 0.04 mg/kg of acepromazine IV. Level of sedation, heart rate, respiratory rate, and blood pressure were recorded for 6 hours after acepromazine administration. Area under the curves (AUCs) of the normalized sedation score results were calculated and compared. RESULTS: The median sedation scores for ABCB1 mut/mut dogs were higher than nor/nor dogs at all time points and were higher in mut/nor dogs for the first 2 hours. These differences were not found to be significant for any individual time point (P > .05). The median sedation score AUC for mut/mut dogs was significantly higher than nor/nor dogs (P = .028), but the AUC for mut/nor dogs was not (P = .45). There were no significant differences between groups for heart rate, respiratory rate, and blood pressure (P > .05). CONCLUSIONS AND CLINICAL IMPORTANCE: In ABCB1 mut/mut dogs acepromazine dose rates should be reduced and careful monitoring performed during sedation.

Thalidomide pharmacokinetics in sheep.

AIM: To determine the half life (T1/2), time taken to reach maximum plasma concentration (Tmax) and maximum plasma concentration (Cmax) of thalidomide in sheep following I/V, oral and topical treatment with a single dose of thalidomide. METHOD: Three groups of 4-6-month-old ram lambs were treated with thalidomide dissolved in dimethylsulphoxide (DMSO). The first group (n=10) was treated I/V with 100 mg thalidomide in 2 mL DMSO; the second group (n=8) received 400 mg thalidomide in 2 mL DMSO orally, and the third group (n=8) had 400 mg thalidomide in 4 mL DMSO applied topically. Plasma samples were collected up to 36 hours after treatment, snap-frozen at -80°C and analysed for concentrations of thalidomide using high performance liquid chromatography. RESULTS: Following I/V administration, T1/2 was 5.0 (SEM 0.4) hours, volume of distribution was 3,372.0 (SEM 244.3) mL/kg and clearance was 487.1 (SEM 46.1) mL/hour.kg. Topical application of 400 mg thalidomide did not increase plasma concentrations. Following oral administration, thalidomide bioavailability was 89%, with T1/2, Tmax, and Cmax being 7.2 (SEM 0.8) hours, 3.0 (SEM 0.4) hours and 1,767.3 (SEM 178.1) ng/mL, respectively. CONCLUSION: Topical administration using DMSO as a solvent did not increase concentrations of thalidomide in plasma. The mean pharmacokinetic parameters determined following oral treatment with 400 mg of thalidomide were similar to those reported in humans receiving a single 400 mg oral dose (T1/2 7.3 hours; Tmax 4.3 hours and Cmax 2,820 ng/mL). There is potential for thalidomide to be used as a model for the treatment of chronic inflammatory conditions in sheep, such as Johne's disease, where tumour necrosis factor alpha plays a pathogenic role.

Regional variations in percutaneous absorption of methimazole: an in vitro study on cat skin.

The use of transdermal gel medications in cats has become popular in veterinary medicine due to the ease of administration compared to oral medication. The research to support systemic absorption of drugs after transdermal gel administration and the preferred skin region to apply these drugs in cats is limited. The aim of this study was to characterize the effect of different skin regions on the percutaneous absorption pharmacokinetics of a commercially available transdermal methimazole after a finite dose was applied to feline skin in vitro. A commercial formulation of methimazole (10 mg) was applied to four skin regions (the inner stratum corneum of the ear, groin, neck, and thorax regions) from six cats. The receptor medium was sampled up to 36 h postapplication, and methimazole concentrations were measured using high-performance liquid chromatography. Methimazole was absorbed more completely across the pinnal skin, compared to the groin, neck, and thorax (P < 0.001), which justifies application to the pinna to maximize efficacy and also to minimize the effects of grooming.

Percutaneous absorption of methimazole: an in vitro study of the absorption pharmacokinetics for two different vehicles.

The use of transdermal medications in cats has become popular in veterinary medicine due to the ease of administration compared to oral medication. However, the research to support systemic absorption of drugs applied to the pinna after transdermal administration in cats is limited. The aim of this study was to characterize the percutaneous absorption pharmacokinetics of methimazole in a lipophilic vehicle compared to methimazole in Pluronic(®) lecithin organogel (PLO) using a finite dose applied to feline ear skin in an in vitro Franz cell model. The two formulations of methimazole (10 mg) were applied to the inner stratum corneum of six pairs of feline ears. The receptor medium was sampled up to 30 h post-administration, and methimazole concentrations were measured using high-performance liquid chromatography (HPLC). Histological examination of all ears was undertaken as small differences in the thickness of ear skin may have contributed to inter-individual differences in methimazole absorption between six cats. Methimazole was absorbed more completely across the pinnal skin when administered in the lipophilic vehicle compared to administration in the PLO gel (P < 0.001).

A molecular transport medium for collection, inactivation, transport, and detection of Mycobacterium tuberculosis.

In many parts of the world, the diagnosis of tuberculosis (TB) has rapidly shifted to molecular detection and sequencing formats. The collection and transport of Mycobacterium tuberculosis specimens thus remains a challenging problem where TB is common and the infrastructure required for ensuring sample integrity is lacking. PrimeStore(®) Molecular Transport Medium (MTM) addresses this problem, rapidly inactivating/killing M. tuberculosis while preserving genomic DNA even at elevated temperatures for subsequent downstream molecular analysis.