Cannabis smoking and abdominal wall reconstruction outcomes: a propensity score-matched analysis.

PURPOSE: Despite increasing use of cannabis, literature on perioperative effects is lagging. We compared active cannabis-smokers versus non-smokers and postoperative wound morbidity and reoperations following open abdominal wall reconstruction (AWR). METHODS: Patients who underwent open, clean, AWR with transversus abdominis release and retromuscular synthetic mesh placement at our institution between January 2014 and May 2022 were identified using the Abdominal Core Health Quality Collaborative database. Active cannabis-smokers were 1:3 propensity matched to non-smokers based on demographics and comorbidities. Wound complications, 30 day morbidity, pain (PROMIS 3a-Pain Intensity), and hernia-specific quality of life (HerQles) were compared. RESULTS: Seventy-two cannabis-smokers were matched to 216 non-smokers. SSO (18% vs 17% p = 0.86), SSI (11.1% vs 9.3%, p = 0.65), SSOPI (12% vs 12%, p = 0.92), and all postoperative complications (46% vs 43%, p = 0.63) were similar between cannabis-smokers and non-smokers. Reoperations were more common in the cannabis-smoker group (8.3% vs 2.8%, p = 0.041), driven by major wound complications (6.9% vs 3.2%, p = 0.004). No mesh excisions occurred. HerQles scores were similar at baseline (22 [11, 41] vs 35 [14, 55], p = 0.06), and were worse for cannabis-smokers compared to non-smokers at 30 days (30 [12, 50] vs 38 [20, 67], p = 0.032), but not significantly different at 1 year postoperatively (72 [53, 90] vs 78 [57, 92], p = 0.39). Pain scores were worse for cannabis-smokers compared to non-smokers at 30 days postoperatively (52 [46, 58] vs 49 [44, 54], p = 0.01), but there were no differences at 6 months or 1 year postoperatively (p > 0.05 for all). CONCLUSION: Cannabis smokers will likely experience similar complication rates after clean, open AWR, but should be counseled that despite similar wound complication rates, the severity of their wound complications may be greater than non-smokers.

Prevalence and associations of presenting near-vision impairment in the Australian National Eye Health Survey.

PurposeTo describe the prevalence and associations of presenting near vision impairment (NVI) in Indigenous and non-Indigenous Australians.MethodsA sample of 3098 non-Indigenous Australians (aged 50-98 years) and 1738 Indigenous Australians (aged 40-92 years) living in 30 randomly selected Australian sites were examined as part of the population-based National Eye Health Survey (NEHS). Binocular presenting NVI was defined as near vision worse than N8 (20/50).ResultsIn total, 4817 participants (99.6% of the total sample, comprising 3084 non-Indigenous Australians and 1733 Indigenous Australians) had complete data on near visual acuity. The overall weighted prevalence of presenting NVI was 21.6% (95% CI: 19.6, 23.8) in non-Indigenous Australians and 34.7% (95% CI: 29.2, 40.8) among Indigenous Australians. In the non-Indigenous population, higher odds of presenting NVI were associated with older age (OR=1.68 per 10 years, P<0.001), fewer years of education (OR=0.95 per year, P<0.001) and residing in Remote geographical areas (OR=1.71, P=0.003) after multivariate adjustments. Among Indigenous Australians, older age (OR=1.69 per 10 years, P<0.001), fewer years of education (OR=0.91 per year, P=0.003) and residing in Inner Regional (OR=2.01, P=0.008), Outer Regional (OR=2.17, P=<0.001) and Remote geographical areas (OR=1.72, P=0.03) were associated with greater odds of presenting NVI.ConclusionsNVI represents a notable public health concern in Australia, affecting approximately 20% of non-Indigenous Australian and one-third of Indigenous Australian adults.

Effect of feeding on the pharmacokinetics of oral minocycline in healthy adult horses.

Minocycline is commonly used to treat bacterial and rickettsial infections in adult horses but limited information exists regarding the impact of feeding on its oral bioavailability. This study's objective was to compare the pharmacokinetics of minocycline after administration of a single oral dose in horses with feed withheld and with feed provided at the time of drug administration. Six healthy adult horses were administered intravenous (2.2 mg/kg) and oral minocycline (4 mg/kg) with access to hay at the time of oral drug administration (fed) and with access to hay delayed for 2 hr after oral drug administration (fasted), with a 7-day washout between treatments. Plasma concentration versus time data was analyzed based on noncompartmental pharmacokinetics. Mean ± SD bioavailability (fasted: 38.6% ± 4.6; fed: 15.7% ± 2.3) and Cmax (fasted: 1.343 ± 0.418 µg/ml; fed: 0.281 ± 0.157 µg/ml) were greater in fasted horses compared to fed horses (p < .05 both). Median (range) Tmax (hr) in fasted horses was 2.0 (1.5-3.5) and in fed horses was 5.0 (1.0-8.0) and was not significantly different between groups. Overnight fasting and delaying feeding hay 2 hr after oral minocycline administration improve drug bioavailability and thus plasma concentrations.

Efficacy of intramuscular meperidine hydrochloride versus placebo in experimental foot lameness in horses.

REASONS FOR PERFORMING STUDY: There are no peer reviewed, blinded controlled studies regarding the skeletal analgesic efficacy of intramuscularly administered meperidine in horses. OBJECTIVES: Using an adjustable heart bar shoe model of equine foot pain, the objective of this study was to test the hypothesis that meperidine (pethidine) administered intramuscularly would prove more efficacious in alleviating lameness than a saline placebo. STUDY DESIGN: Crossover pharmacodynamic experiment. METHODS: Eight healthy adult Thoroughbred horses randomly underwent weekly i.m. treatments 1 h after lameness induction: saline placebo (1 ml/45 kg bwt) or meperidine hydrochloride (1 mg/kg bwt i.m.). Heart rate (HR) and lameness score (LS) responses were assessed by a blinded observer every 20 min for 5 h after lameness induction and then hourly through 12 h after treatment. Jugular venous blood samples were obtained at -1, 0, 0:05, 1, 2, 4, 6, 8, 10 and 12 h and were subsequently analysed for drug concentrations (lower limit of detection, 1 ng/ml). Repeated measures ANOVA and post hoc Tukey's test were used to identify analgesic effects at a significance level of P<0.05. RESULTS: Mean (± s.e.) HR were lower in meperidine trials at 2.3, 3.3 and 3.7 h post administration (P<0.05). Mean LS were lower in meperidine trials at 2.0, 2.3 and 3.3 h post administration (P<0.05). Mean plasma (meperidine) peaked at 227 ± 52 ng/ml at 1 h post administration and decreased to 2.7 ± 0.3 ng/ml at 12 h post administration. In 3 of 8 subjects, plasma (meperidine) was below the lower limit of detection at 12 h after administration. CONCLUSIONS: Intramuscular meperidine was more effective than the saline placebo but only for 2.0-3.7 h post administration compared with the 8-12 h durations of efficacy reported previously using this same model when horses were treated with nonsteroidal anti-inflammatory drugs (NSAIDs). Meperidine may be a suitable nonNSAID alternative analgesic for acute foot pain with efficacy lasting from 2-3 h after a single i.m. dose.

Multidisciplinary decisions in breast cancer: does the patient receive what the team has recommended?

BACKGROUND: A multidisciplinary team (MDT) approach to breast cancer management is the gold standard. The aim is to evaluate MDT decision making in a modern breast unit. METHODS: All referrals to the breast MDT where breast cancer was diagnosed from 1 July 2009 to 30 June 2011 were included. Multidisciplinary team decisions were compared with subsequent patient management and classified as concordant or discordant. RESULTS: Over the study period, there were 3230 MDT decisions relating to 705 patients. Overall, 91.5% (2956 out of 3230) of decisions were concordant, 4.5% (146 out of 3230), were discordant and 4% (128 out of 3230) had no MDT decision. Of 146 discordant decisions, 26 (17.8%) were considered 'unjustifiable' as there was no additional information available after the MDT to account for the change in management. The remaining 120 discordant MDT decisions were considered 'justifiable', as management was altered due to patient choice (n=61), additional information available after MDT (n=54) or MDT error (n=5). CONCLUSION: The vast majority of MDT decisions are implemented. Management alteration was most often due to patient choice or additional information available after the MDT. A minority of management alterations were 'unjustifiable' and the authors recommend that any patient whose treatment is subsequently changed should have MDT rediscussion prior to treatment.

Effects of low-dose dopamine on urine output in normotensive very low birth weight neonates.

OBJECTIVE: To determine the effects of low-dose dopamine on urine output (UOP) in very low birth weight premature neonates. STUDY DESIGN: Retrospective cohort study of all low-dose (3-5 µg kg(-1) per min) dopamine infusions >24-h duration in neonates 1500 g and 32 weeks gestation from August 2009 through September 2011. Linear regression was used to estimate the impact of covariates on UOP. RESULT: We identified 91 episodes of low-dose dopamine use in 65 neonates. Increased UOP occurred in 64% of episodes. Low-dose dopamine use was associated with a 0.6 ml kg(-1) h(-1) increase in UOP (P<0.001) and a 1.3 ml kg(-1)h(-1) increase when baseline UOP was <1.5 ml kg(-1) h(-1) (P<0.001). The improvement remained statistically significant after controlling for medications (diuretics and hydrocortisone) and fluid intake. CONCLUSION: Low-dose dopamine use was associated with increased UOP in very low birth weight neonates.

The effects of hyperglycemia and endotoxemia on coagulation parameters in healthy adult horses.

BACKGROUND: Hyperglycemia and endotoxemia have been associated with coagulation abnormalities in horses. Studies in humans suggest greater disturbances in coagulation with hyperglycemia and concurrent endotoxemia. OBJECTIVES: To compare coagulation parameters in horses administered with lipopolysaccharide (LPS) with and without concurrent hyperglycemia. ANIMALS: Twelve healthy adult horses. METHODS: Hyperglycemia (180-240 mg/dL) was maintained for 6 hours in 6 horses (GLU-LPS) using 140 mg/kg IV bolus of dextrose followed by a 20% dextrose constant rate infusion. A similar volume of saline was administered to an additional 6 horses (SAL-LPS). LPS (20 ng/kg) was administered to each horse. Fibrogen concentration, prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin antithrombin concentration (TAT), and thromboelastometry were measured at baseline and after 1, 1.5, 2, 2.5, 3, 4, 6, and 22 hours. Repeated measures analysis of variance was used to examine temporal changes. RESULTS: Increases in PT (P = .001) and TAT (P = .027) were observed in the GLU-LPS group. Changes in thromboelastometry parameters including increased clot formation time (In-TEM, P = .006; Ex-TEM, P = .002) and decreased alpha angle (Ex-TEM, P = .04) and maximal clot firmness (Ex-TEM, P = .014) were observed in the SAL-LPS group. Differences between SAL-LPS and GLU-LPS groups were limited to increased maximal clot firmness (Ex-TEM) at 3, 6, and 22 hours (P < .001) in the SAL-LPS group. CONCLUSIONS AND CLINICAL IMPORTANCE: Minor alterations in coagulation parameters identified for each group are most likely not clinically relevant. Observed differences between groups do not suggest that concurrent hyperglycemia and endotoxemia are associated with greater coagulation abnormalities in horses.

Thermal emission from a metamaterial wire medium slab.

We investigate thermal emission from a metamaterial wire medium embedded in a dielectric host and highlight two different regimes for efficient emission, respectively characterized by broadband emission near the effective plasma frequency of the metamaterial, and by narrow-band resonant emission at the band-edge in the Bragg scattering regime. We discuss how to control the spectral position and relative strength of these two emission mechanisms by varying the geometrical parameters of the proposed metamaterial and its temperature.

Dose titration of the clinical efficacy of intravenously administered flunixin meglumine in a reversible model of equine foot lameness.

REASONS FOR PERFORMING STUDY: There are no refereed controlled documentations of the skeletal analgesic efficacy of different dosages of flunixin meglumine (FM). OBJECTIVES: The objective of this experiment was to compare the efficacy of various dosages of FM with a negative control. The hypothesis was that higher doses would result in improved efficacy in a dose-dependent manner when tested in a reversible model of foot lameness. METHODS: Ten horses shod with adjustable heart bar shoes had weekly modified AAEP grade 4.0/5.0 lameness induced by tightening a set screw against the heart bar. Heart rate (HR) and lameness score (LS) were monitored by one double-blinded investigator at rest; every 20 min after lameness induction for 5 h and hourly for another 8 h. One hour after lameness induction, treatments were administered i.v. in a randomised order: negative control (isotonic saline: SAL) or FM at 0.55 (half-dose), 1.1 (single-dose) or 2.2 (double-dose) mg/kg bwt. Results were compared using RM ANOVA and Student-Newman-Keul's test with the level of significance set at P < 0.05. RESULTS: Compared to SAL, half-dose FM reduced HR at 2.33, 2.67, 4.0-8.0, and 10.0 h and LS at 1.33-12.0 h (P < 0.05). Single- and double-dose FM reduced HR from 0.67 to 12.0 h and LS from 1.0 to 12.0 h post administration (P < 0.05). Compared with half-dose FM, single- and double-dose LS were further decreased from 1.67 to 12.0 h post administration (P < 0.05). Mean peak and decaying plasma FM concentrations were different between dosages in a dose-dependent manner through 6 h post administration (P < 0.05). CONCLUSIONS: Flunixin meglumine administration affected dependent variables in a dose-dependent manner with half-dose FM clinically effective for a shorter period. Higher dosages did not perform differently from one another. POTENTIAL RELEVANCE: Practitioners must be aware that half-doses of FM are less efficacious than single doses but double doses are not more efficacious and yet are potentially more toxic.

The relationship between serum calcium concentration and outcome in horses with renal failure presented to referral hospitals.

BACKGROUND: Hypercalcemia is common in horses with renal failure, but it is not known whether it impacts prognosis. HYPOTHESIS/OBJECTIVES: The primary objective of this study was to determine whether hypercalcemia was associated with decreased likelihood of survival to discharge in horses with renal failure. Secondary objectives were to determine whether hypercalcemia was more common in acute (ARF) or chronic renal failure (CRF), whether feeding alfalfa was associated with hypercalcemia, and whether serum creatinine concentration was associated with survival. ANIMALS: Medical records of 63 horses presented to referral hospitals for renal failure were evaluated. Cases were classified as ARF or CRF based on historical and clinical findings. METHODS: The distribution of hypocalcemic, normocalcemic, and hypercalcemic cases in the ARF and CRF groups was determined. Mean serum calcium and creatinine concentrations for survivors and nonsurvivors, and for ARF and CRF cases, were compared. Mean serum calcium concentrations for cases fed alfalfa or not fed alfalfa were compared. RESULTS: Hypercalcemia was significantly more common in CRF than ARF cases. CRF cases fed alfalfa were significantly more likely to be hypercalcemic. There was no significant difference in serum calcium concentration between survivors and nonsurvivors. Serum creatinine concentration was significantly higher in nonsurvivors and in ARF cases. CONCLUSIONS AND CLINICAL IMPORTANCE: Horses with CRF are more likely to be hypercalcemic than horses with ARF. Hypercalcemia was not associated with outcome in renal failure cases in this study. Additional research on the impact of dietary calcium on long-term well-being in horses with CRF is warranted.

Phenylbutazone and flunixin meglumine used singly or in combination in experimental lameness in horses.

REASON FOR PERFORMING STUDY: Using an adjustable heart bar shoe model of foot pain, the objective of this study was to test the hypothesis that the combined use of phenylbutazone (PBZ) and flunixin meglumine (FM) would prove more efficacious in alleviating lameness than either drug alone. MATERIALS AND METHODS: One hour after induction of lameness at weekly intervals, 8 healthy adult Thoroughbred horses randomly underwent one of 4 i.v. treatments: saline (SAL) placebo (1 ml/45 kg bwt), PBZ (4.4 mg/kg bwt), FM (1.1 mg/kg bwt) or PBZ+FM (at the same dosages as given individually). Heart rate (HR) and lameness score (LS) responses were assessed in a blinded manner every 20 min for 5 h after lameness induction and then hourly for 12 h after treatment. Jugular venous blood samples were obtained at -1, 0, 0.05, 1, 2, 4, 6, 8, 10 and 12 h and subsequently analysed for drug concentrations. Repeated measures ANOVA and post hoc Tukey's test were used to identify analgesic effects at a significance level of P<0.05. RESULTS: Heart rate was lower in all nonsteroidal anti-inflammatory drug (NSAID)-treated trials from 2 h to 10 h post treatment (P<0.05). Analgesic effects of FM and PBZ+FM, as evidenced by decreases in HR, lasted for 12 h post treatment (P<0.05). Lameness score decreased earlier in PBZ and PBZ+FM trials than in FM trials (P<0.05) and the analgesic effect on LS lasted for 12 h post treatment for all NSAID trials (P<0.05). Peak PBZ plasma concentration was 73.7 ± 6.0 and 77.9 ± 5.5 µg/ml. Peak FM concentration was 12.0 ± 0.8 and 13.7 ± 1.0 µg/ml. CONCLUSIONS: It was concluded that the combination of PBZ+FM was not more effective than either PBZ or FM alone. These data do not support the hypothesis that the combination is more efficacious at these dosages than either drug alone in this model of acute foot pain.

Validation and comparison of two methods of measuring lactate in equine plasma.

REASONS FOR PERFORMING STUDY: Some methods of lactate (LA) measurement have not been validated appropriately for use in horses. OBJECTIVES: To validate 2 LA analysers (YSI 2300 Stat Plus and TDx Lactic Acid Assay) for use with equine plasma and to compare plasma [LA] determined by the 2 methods. METHODS: Both instruments were evaluated for linearity, parallelism, recovery and precision using serial dilutions of standard LA solutions and equine plasma and then comparing results with linear regression or paired t tests. Plasma [LA] results were compared in 275 blood samples collected from horses exercising at various intensities using Bland-Altman analysis. Level of significance was P < 0.05. RESULTS: YSI exhibited good linearity for both LA standards and equine plasma (P < 0.05) at 0-30 mmol/l. TDx had good linearity at 0-12 mmol/l (P < 0.05); with LA standard solutions >12 mmol/l and with equine plasma, linearity was decreased. YSI exhibited good parallelism between LA standards and equine plasma LA measurements throughout the 0-30 mmol/l range (P > 0.05). Parallelism was poor with TDx (P < 0.05). Mean ± s.d. % recovery was 101.7 ± 3.4% for YSI (acceptable) and 110.6 ± 8.4% for TDx (unacceptable). Within-run and mean between-run coefficients of variation (CV) for plasma samples tested from 3.3-29.5 mmol/l were 0.4-3.0% for YSI. CVs for samples tested from 2.8-8.0 mmol/l were 17.4-24.1% for TDx. In 275 plasma samples, [LA] ranged from 0.1-42.7 mmol/l and 0.3-50.6 mmol/l for the YSI and TDx methods, respectively. The difference in plasma [LA] determined by the 2 methods was -1.0 ± 3.2 mmol/l, documenting that the TDx overestimated the YSI results by a mean value of 1 mmol/l. CONCLUSIONS: It was concluded that the YSI method was a reliable method for measuring equine plasma [LA] from 0-30 mmol/l. The TDx method was found not to be suitable for use with equine plasma due to greater variability in measurements (high CV).

Efficacy of single-dose intravenous phenylbutazone and flunixin meglumine before, during and after exercise in an experimental reversible model of foot lameness in horses.

REASONS FOR PERFORMING STUDY: Objective blinded efficacy data during exercise are lacking on the use of single-dose i.v. nonsteroidal anti-inflammatory drugs (NSAIDs) before, during and after exercise. HYPOTHESIS: Single i.v. doses of either phenylbutazone (PBZ) or flunixin meglumine (FM) would prove more efficacious than negative saline control (SAL) before, during and after exercise in a reversible model of foot lameness. METHODS: Six Quarter Horse mares had lameness induced by tightening a set screw against a heart bar shoe 1 h prior to treatment. Randomised blinded treatments included PBZ (4.4 mg/kg bwt i.v.), FM (1.1 mg/kg bwt i.v.), and SAL (1 ml/45 kg i.v.). Heart rate and lameness score (LS) were recorded at rest; every 20 min after lameness induction for 5 h and at the end of 2 min treadmill workloads of 2 and 4 m/s. Heart rate was also recorded from 0.5-60 min post exercise. Results were compared using RM ANOVA and Student-Newman-Keul's test (HR) and Wilcoxon signed rank test (%ΔLS) with significance set at P < 0.05. RESULTS: Pre-exercise mean HR was decreased for both NSAIDs compared to SAL from 1:20-4 h post treatment (P < 0.05). Pre-exercise mean %ΔLS was decreased for PBZ (1:20-4 h) and FM (1-4 h) compared to SAL (P < 0.01). With exercise, there were no HR differences between treatments (P > 0.05), but mean %ΔLS was decreased for both NSAIDs compared to SAL (P < 0.01). Mean recovery HR was decreased for PBZ and FM from 1-60 min compared to SAL (P < 0.05). CONCLUSIONS: PBZ and FM demonstrated definitive clinical efficacy after single i.v. doses before, during and after exercise. Use of single i.v. doses during competition may mask lameness and may affect the ability of judges in determining the soundness of horses in competition.

Genetic architecture for hole-board behaviors across substantial time intervals in young, middle-aged and old mice.

A quantitative trait locus (QTL) analysis of behaviors across the life span was conducted in F(2) mice from a C57BL/6J x DBA/2J cross and 22 BXD recombinant inbred (RI) strains. Mice of three age groups were tested in a hole-board apparatus for 3 min on three occasions approximately 1 month apart (average age at test 150, 450 and 750 days, approximately 400 mice per group, divided equally by sex). Quantitative trait loci with small effect size were found on 11 chromosomes for hole-board activity (Hbact) and hole-board rearing (Hbrear). Analysis of 22 RI strains tested at 150 and 450 days of age found only suggestive linkage, with four QTL for Hbact overlapping with those from the F(2) analysis. There was a significant phenotypic correlation between Hbact and Hbrear (approximately 0.55-0.69) and substantial commonality among QTL for the two behaviors. QTL analyses of head-pokes (HP) and fecal boli (FB) only identified QTL at the suggestive level of significance. Age accounted for approximately 15% of the phenotypic variance (sex approximately 3%), and there were genotype by age interactions at approximately 25% of the Hbact and Hbrear QTL. Quantitative trait loci for Hbrear were relatively stable across the three measurement occasions (those for Hbact somewhat less so), although mean levels of each index declined markedly comparing the first to subsequent trials. Considered as a whole, the polygenic system influencing exploratory behaviors accounts for approximately the same amount of phenotypic variance as age (within the range studied), is stable across substantial periods of time, and acts, for the most part, independently of age and sex.

Effects of radial extracorporeal shock wave therapy on radiographic and scintigraphic outcomes in horses with palmar heel pain.

OBJECTIVE: To investigate the effects of radial extracorporeal shock wave therapy (RESWT) on radiographic and scintigraphic variables in horses with clinical pain referable to the palmar heel. METHODS: Eight client-owner horses with palmar heel pain were treated with RESWT for a total of three treatments. Nuclear scintigraphy and radiography were repeated at the beginning and completion of the study. Scintigram region of interest (ROI) density ratios were calculated and compared between treated limbs, untreated limbs, and a population of comparison limbs from eight horses free of lameness. Radiographs were scored for whole navicular bone appearance as well as distal border synovial fossae number and severity. RESULTS: There was not any pre- versus post-treatment difference in scintigraphic navicular pool phase or delayed phase ROI density ratios in treated limbs, or between treated and untreated limbs. Delayed phase ROI density was increased in the central navicular region in treated limbs compared to comparison limbs from non-lame horses at both time points. Radiographic scores remained unchanged. CLINICAL SIGNIFICANCE: RESWT as applied in the present study has no effect on acute palmar heel region scintigraphic or radiographic parameters. Any acute clinical benefit may be due to analgesic effects rather than stimulation of local tissue metabolism.

Effects of single-dose intravenous phenylbutazone on experimentally induced, reversible lameness in the horse.

The objective was to test the hypothesis that phenylbutazone (PBZ) alleviates lameness in an adjustable heart bar shoe model of equine foot pain. Eight Quarter Horse mares underwent 4-weekly treatments randomly: 0.9% saline placebo (SAL: 1 mL/45 kg body weight i.v.) with no lameness; SAL with lameness; PBZ (4.4 mg/kg body weight i.v.) with no lameness; and PBZ with lameness. Blinded heart rate (HR) and lameness score (LS) were assessed every 20 min for 2 h and then hourly through 9 h. At 1 h SAL or PBZ was administered. Jugular venous samples were obtained at hours 0, 1, 2, 4, 6, and 8 and were evaluated for packed cell volume (PCV), cortisol, and drug concentrations. Repeated measures anova and t-tests were used to identify PBZ effects at a significance level of P<0.05. PBZ-treated LS was lower 2-8 h post-treatment, and HR was lower from 2 through 6 h post-treatment (P<0.05). Phenylbutazone did not change PCV and had minimal effect on cortisol. Mean plasma PBZ and oxyphenbutazone concentrations 7 h after treatment were 7.2-7.5 and 1.6-1.9 microg/mL, respectively. It was concluded that PBZ was efficacious in alleviating lameness in this model. Cortisol and PCV were not discriminating enough to distinguish between PBZ-treated and SAL-treated trials.

Effects of a pre-moistened multilayered breathable fabric in promoting heat loss during recovery after exercise under hot conditions.

REASONS FOR PERFORMING STUDY: Horses generate considerable internal heat burdens when exercising. Although common practice for a trainer or groom to place a wet blanket or towel on the dorsum of a hot horse post exercise, there are no data supporting the efficacy of this cooling method. OBJECTIVE: To test the hypothesis that a pre-moistened blanket designed with a multilayered breathable fabric would enhance heat loss in horses post exercise. METHODS: Eight treadmill-trained horses performed a standardised exercise test (SET) weekly for 3 weeks, with 3 different recovery treatments administered randomly. Pulmonary artery temperature (PAT) was measured via Swan-Ganz catheter. The SET consisted of 10 min at 3.7 m/sec, 3 min at 11.0 m/sec, 25 min at 3.7 m/sec and 20 min of recovery walking at 2.0 m/sec (58 min exercise and recovery under laboratory conditions of 35.0-40.6 degrees C and 27-49% RH). From 3-7 min during recovery, the treadmill was stopped and horses randomly received either: (a) no bath (negative control); (b) a bath consisting of 32 l of 1-4 degrees C water split into 3-4 cycles of bilateral water application (positive control) followed by water removal ('scraping'); or (c) application of a multilayered fabric blanket soaked in 16-19 degrees C water, wrung out, and placed over the dorsum and sides of the horse. PAT was compared using RM ANOVA with the Student Neuman-Keul's test used post hoc to discriminate between treatments at specific points in time. RESULTS: Mean PAT rose with each phase of exercise (P<0.001) and peaked at a mean of 40.2 +/- 0.2 degrees C. During recovery, the cold bath decreased HR and PAT for 9 min after walking resumed (P<0.001-P<0.05). The blanket did not decrease HR or PAT compared to negative control (P>0.05), and both were hotter than the cold bath treatment through 16 min of recovery (P<0.05). CONCLUSIONS: A specially-designed cooling blanket failed to reduce PAT when compared to negative control. Cold water bathing decreased HR and PAT but was not effective throughout all of recovery. POTENTIAL RELEVANCE: A specially-designed, pre-moistened multilayered breathable fabric failed to promote evaporative cooling compared to negative control. Cold water baths may need to be repeated throughout recovery to optimise their effect.

Influence of molecular weight on the phase behavior and structure formation of branched side-chain hairy-rod polyfluorene in bulk phase.

We report on an experimental study of the self-organization and phase behavior of hairy-rod pi -conjugated branched side-chain polyfluorene, poly[9,9-bis(2-ethylhexyl)-fluorene-2,7-diyl]-i.e., poly[2,7-(9,9-bis(2-ethylhexyl)fluorene] (PF2/6) -as a function of molecular weight (M(n)) . The results have been compared to those of phenomenological theory. Samples for which M(n) =3-147 kg/mol were used. First, the stiffness of PF2/6 , the assumption of the theory, has been probed by small-angle neutron scattering in solution. Thermogravimetry has been used to show that PF2/6 is thermally stable over the conditions studied. Second, the existence of nematic and hexagonal phases has been phenomenologically identified for lower and higher M(n) (LMW, M(n) < M(*)(n) and HMW, M(n) > M(*)(n) ) regimes, respectively, based on free-energy argument of nematic and hexagonal hairy rods and found to correspond to the experimental x-ray diffraction (XRD) results for PF2/6 . By using the lattice parameters of PF2/6 as an experimental input, the nematic-hexagonal transition has been predicted in the vicinity of glassification temperature (T(g)) of PF2/6 . Then, by taking the orientation parts of the free energies into account the nematic-hexagonal transition has been calculated as a function of temperature and M(n) and a phase diagram has been formed. Below T(g) of 80 degrees C only (frozen) nematic phase is observed for M(n)< M(*)(n) = 10(4) g/mol and crystalline hexagonal phase for M(n) > M(*)(n) . The nematic-hexagonal transition upon heating is observed for the HMW regime depending weakly on M(n) , being at 140-165 degrees C for M(n) > M(*)(n). Third, the phase behavior and structure formation as a function of M(n) have been probed using powder and fiber XRD and differential scanning calorimetry and reasonable semiquantitative agreement with theory has been found for M(n) >or=3 kg/mol. Fourth, structural characteristics are widely discussed. The nematic phase of LMW materials has been observed to be denser than high-temperature nematic phase of HMW compounds. The hexagonal phase has been found to be paracrystalline in the (ab0) plane but a genuine crystal meridionally. We also find that all these materials including the shortest 10-mer possess the formerly observed rigid five-helix hairy-rod molecular structure.

Correlation of the photodetachment rate of a scarred resonance state with the classical Lyapunov exponent.

A metastable resonance state of the periodically driven Gaussian potential well is shown to be scarred on a single unstable periodic orbit of the classical motion. The photodetachment rate of this quantum state is strongly correlated with the Lyapunov exponent of the unstable periodic orbit over a wide range of driving field strengths.

Forelimb skeletal scintigraphy responses in previously untrained Thoroughbreds undergoing initial treadmill training.

Scintigraphy has been used in numerous clinical settings to examine horses to determine the origin of lameness problems, but it has not been used previously to monitor prospectively the skeletal responses of a group of similarly-trained racehorses. Our hypothesis was that in naïve Thoroughbred (TB) racehorses, initial treadmill training induces increased radiopharmaceutical uptake in high-motion joints and in the dorsal third metacarpal bone (MC3). Eight previously-untrained TB racehorses underwent sequential skeletal scintigraphic examinations as they exercised daily for 9 weeks on an inclined treadmill. At the end of Weeks 0 (pre-training), 3 (trotting at 4.2 m/s and initial galloping), 6 (galloping at 7.5 m/s), and 9 (sprinting 600 m at 12.5 m/s), horses received 140 mCi 99m Technetium-methylene diphosphonate i.v. followed by a standard skeletal scintigraphic forelimb examination 2 h later. Views were graded for increased radiopharmaceutical uptake by 3 co-investigators who were blinded to horse identification, breed, sex, date, and clinical findings. Results were compared before and after training for each skeletal location using the Mann-Whitney Rank Sum Test with the level of significance set at P<0.05. Initial treadmill training resulted in increased radiopharmaceutical uptake in the carpus (P = 0.031), metacarpophalangeal joint (P = 0.021), proximal phalanx (P = 0.035), and distal phalanx (P = 0.003). Training did not affect dorsal MC3 radiopharmaceutical uptake (P>0.05).