Levofloxacin pharmacokinetics and tissue residue concentrations after oral administration in Bilgorajska geese

1. The aim of this study was to assess the pharmacokinetics of levofloxacin, a third-generation fluoro-quinolone antimicrobial drug, in geese (n = 26) after either single intravenous or oral administration, and to evaluate the depletion profile in goose muscle, heart, liver, kidney and lung after a single oral dose.2. The pharmacokinetic study involved 16 geese which were randomly divided into two groups (n = 8/group), the first received levofloxacin (2 mg/kg) intravenously while the second was treated with orally (5 mg/kg). The tissue depletion study involved 10 geese which were dosed orally (5 mg/kg) and two animals were killed at different time-points in order to collect the selected tissues. Levofloxacin was quantified in all the matrices tested by a validated high-performance liquid chromatography (HPLC) method, using a spectrofluorimetric detector. The pharmacokinetics were analysed using a non-compartmental model.3. Plasma concentrations were quantified after up to 24 h in animals administered intravenously and up to 48 h after oral treatment. Levofloxacin was rapidly absorbed after oral administration (T_max = 0.38 h) showing high bioavailability (95.57 ± 20.61%). The drug showed a moderate volume of distribution (1.40 ± 0.28 ml/g) and rapid clearance (0.28 ± 0.06 ml/g/h). No statistical differences in estimates were found between the two different administration methods (P > 0.05). Drug residues were highest at 6 h and decreased constantly up to 48 h in all the selected tissues. Liver and kidney had the highest levofloxacin concentrations.4. According to the pharmacokinetic/pharmacodynamic surrogate index (AUC/MIC) the levofloxacin dose regimen (after oral administration) used in the present study could be active against bacteria at a minimum inhibitory concentration (MIC) > 0.24  μg/ml in geese. In addition, drug accumulation in the liver might be controlled using an estimated preliminary withdrawal time of 90 h.

Neonatal outcome in pregnancy hypotiroidee women

To evaluate the impact that hypothyroidism may have on the course of pregnancy and on neonatal outcome. This cross-sectional study consisting of 160 pregnant women (60 with hypothyroidism and 100 as control) who had been hospitalized at the Obstetrics and Gynecology of the University of Siena. The obstetric visit, the collection of anamnestic data and serum concentrations of TSH, FT4 and AbTPO were performed for each woman. Stratification of the population into two groups based on the BMI showed that there is an average difference of -0.88 before pregnancy BMI between healthy women and hypothyroid women. Moreover, with regard to the obstetric history, 8.7 times higher risk of abortion was found in hypothyroid women. About the current pregnancy in hypothyroid women, slight fetal growth delay, increased risk of premature rupture of membranes (PROM), and a higher risk of developing hypertension and gestational diabetes had been found. The importance of a more detailed anamnesis should be evaluated with greater attention at the beginning of pregnancy. This, in order to avoid the risks related to a hypothyroidism condition during pregnancy and to establish an early therapeutic treatment appropriate to the metabolic demands of each patient.

Concentrations in plasma and selected tissues of marbofloxacin after oral and intravenous administration in Bilgorajska geese (Anser anser domesticus)

Aims: To determine the pharmacokinetics and tissue depletion of 2 mg/kg marbofloxacin (MBX) in Bilgorajska geese (Anser anser domesticus) after I/V and oral administration, to calculate the daily dose from experimental data and to compare it with that calculated by allometric scaling.Methods: Eight clinically normal female Bilgorajska geese were used in a three-phase study with a 3-week wash-out period between phases. In the first phase birds received I/V administration of 2 mg/kg MBX; the same dose was given orally in the second and third phases. Blood samples were collected between 0 minutes and 48 hours in the first and second phases, and samples of liver, kidney, lung, muscle and heart were collected following slaughter of birds between 6 and 48 hours in the third phase. Concentrations of MBX in plasma and tissues were analysed using HPLC. Two additional birds served as controls. The optimal dose was calculated based on a minimal inhibitory concentration (MIC) of 0.125 μg⁄mL using the observed clearance, or using clearance calculated by allometric scaling.Results: Concentrations of MBX in plasma were detectable up to 24 hours following both I/V and oral administration. Mean oral bioavailability was 26.5 (SD 7.7)%. Concentrations of MBX in all tissues were highest at 6 hours and decreased constantly up to 34 hours. The mean optimal daily dose for oral administration of MBX, calculated using the observed clearance was 10.36 (SD 2.18) mg/kg, and using predicted clearance was 5.54 (SD 0.14) mg/kg. The preliminary withdrawal time for a maximum residue limit of 0.15 mg/kg calculated for muscle was 38.4 hours, heart 33.6 hours, kidney 48.3 hours, lung 47.7 hours and liver 49.3 hours.Conclusion and Clinical Relevance: There was insufficient evidence to recommend MBX orally administered to geese at a daily dose of 2 mg⁄kg for treatment of bacteria with an MIC of 0.125 μg/mL. Further pharmacokinetic/pharmacodynamic studies in geese are recommended to determine the MBX dose regimen and its clinical efficacy in geese.

Pharmacokinetic profiles of 5 mg/kg ibudilast, a phosphodiesterase inhibitor, orally administered to dogs in fasted and non-fasted states. A preliminary study

Ibudilast (AV-411) is a non-selective inhibitor of cyclic nucleotide phosphodiesterase (PDE). It is currently marketed for human use in Asian countries for the treatment of asthma, cerebrovascular disorders and ocular allergies. Ibudilast has also been found to have an analgesic action for neuropathic pain at doses 5-10 times higher than those used in asthma therapy. Six healthy Labrador dogs were randomly assigned to two treatment groups using an open, single-dose, two-treatment, two-phase, cross-over design (2x2 Latin-square). Dogs in group 1 (n=3) were fasted for at least 10 hours overnight before the beginning of the experiment and 4 h following dosing while dogs in group 2 (n=3) received food ad libitum. During the first phase, each dog in group 1 and 2 received a single dose of 5 mg/kg ibudilast administered orally. After 1-week washout period the groups were rotated and the experiment was repeated. The analytical method, validated for dog plasma, was shown to be linear in the range 0.10-20 μg/mL. The limit of detection (LOD) and quantification (LOQ) were 0.03 and 0.1 μg/mL, respectively. No behavioural or health alterations were observed in the animals during or after the study. Ibudilast was detectable in plasma for up to 24 h showing a wide variability between animals. Although no statistically significant differences were observed in the present study between the fed and fasted states, examination of the raw data suggests that an effect may be present. The wide degree of variation observed in area under the curve (AUC) suggests that the investigation of population pharmacokinetic modelling is warranted.

Supplementation with rumen-protected proteins induces resistance to Haemonchus contortus in goats

Resistance to gastro-intestinal nematode (GIN) in small ruminant is expected to arise from protein-rich rather than from energy-rich feeds. The objective of this study was to investigate the effect of the quality of the dietary proteins on the response of Creole goats to Haemonchus contortus. Three diets were compared: no supplementation (Hay: hay ad libitum), Control supplement (CS: hay ad libitum +2% BW of CS at 70 g of by-pass proteins/kg) and supplement enriched in rumen-protected proteins (RPP: hay ad libitum +2% BW of RPP at 139 g of by-pass proteins/kg). The FEC (faecal eggs counts) and the TFEC (total faecal eggs excreted/day) were significantly lower in the RPP. No difference was found between the supplemented diets for the total number of nematodes, but the RPP reduced the parasite prolificacy. The highest IgA responses were observed in animals with the highest nematode burden (Hay compared with CS diets). However, while the FEC and the TFEC were lower in animals feed with the RPP the IgA response were similar to those of the Hay. The IgA response that control GIN egg production in sheep could be one mediator of the resistance to H. contortus induced with by-pass proteins in goats.

Validation of finite element models of the mouse tibia using digital volume correlation

The mouse tibia is a common site to investigate bone adaptation. Micro-Finite Element (microFE) models based on micro-Computed Tomography (microCT) images can estimate bone mechanical properties non-invasively but their outputs need to be validated with experiments. Digital Volume Correlation (DVC) can provide experimental measurements of displacements over the whole bone volume. In this study we applied DVC to validate the local predictions of microFE models of the mouse tibia in compression. Six mouse tibiae were stepwise compressed within a microCT system. MicroCT images were acquired in four configurations with applied compression of 0.5 N (preload), 6.5 N, 13.0 N and 19.5 N. Failure load was measured after the last scan. A global DVC algorithm was applied to the microCT images in order to obtain the displacement field over the bone volume. Homogeneous, isotropic linear hexahedral microFE models were generated from the images collected in the preload configuration with boundary conditions interpolated from the DVC displacements at the extremities of the tibia. Experimental displacements from DVC and numerical predictions were compared at corresponding locations in the middle of the bone. Stiffness and strength were also estimated from each model and compared with the experimental measurements. The magnitude of the displacement vectors predicted by microFE models was highly correlated with experimental measurements (R² >0.82). Higher but still reasonable errors were found for the Cartesian components. The models tended to overestimate local displacements in the longitudinal direction (R² = 0.69-0.90, slope of the regression line=0.50-0.97). Errors in the prediction of structural mechanical properties were 14% ± 11% for stiffness and 9% ± 9% for strength. In conclusion, the DVC approach has been applied to the validation of microFE models of the mouse tibia. The predictions of the models for both structural and local properties have been found reasonable for most preclinical applications.

Medical Students' Attitude Toward Organ Donation: Understanding Reasons for Refusal in Order to Increase Transplantation Rates

OBJECTIVES

To assess, among medical students, the willingness to donate their own organs or those of a family member, and to establish reasons for refusal.

MATERIALS AND METHODS

During the 2016 academic year, an anonymous survey was conducted among University of Buenos Aires School of Medicine second-year students.

RESULTS

Of the total 1012 respondents, 81.92% would agree to donate and 18.08% would not. Thirty two percent would not authorize donation of a family member's organ. Almost all (94.1%) students reported they had little information about organ donation. Reasons for refusal included: fears about the possibility of not being really dead when considered for organ ablation (36.4%); lack of confidence in (25.8%) or lack of information about the organ procurement and transplantation system (14.6%); no interest in organ donation (9.3%); and religious reasons (6%). Brain death was considered irreversible by 59.7% of donors and by only 51% of non-donors (P = .036). Contact with a transplanted person was more frequent in the donor group (30.9% vs 21.3%, P = .01). More donors were found among the group who discussed the subject with their families than among the group who did not (69.1% vs 62.9%, P = .053).

CONCLUSIONS

A considerable percentage of medical school students would not be willing to donate their own or a family member's organs. Main reasons are mistrust of the system, lack of information about donation programs, and poor understanding of the brain death concept. Contact with an organ recipient and discussing the subject in the family both favored donation.

NA62 and NA48/2 results on search for Heavy Neutral Leptons

In this paper we present new results on upper limits for the search of Heavy Neutral Leptons (HNL) with data collected by NA48/2 (2003-2004), NA62-RK (2007) and NA62 (2015) CERN experiments. The data collected with different trigger configuration allow to search for both long and short living heavy neutrinos in the mass range below the kaon mass. In addition the status of the search for K+ → π+vv with the NA62 detector will be briefly presented.

Pharmacokinetics of tapentadol in laying hens and its residues in eggs after multiple oral dose administration

1. The aim of the study was to evaluate the pharmacokinetics (PKs) of tapentadol (TAP), a novel opioid analgesic, in laying hens after intravenous (IV) and oral (PO) administration and to quantify the concentrations of TAP residues in eggs. 2. Twenty healthy laying hens were divided into three groups: A (n = 6), B (n = 6) and C (n = 8). The study was conducted in two phases. Groups A and B received TAP by IV and PO routes at the dose of 1 and 5 mg/kg, respectively. 3. No visible adverse effects were observed after administration of the drug. TAP plasma concentrations were detectable up to 4 h following administration. Following IV administration, TAP plasma concentrations were only higher than the minimal effective concentration (148 ng/ml) reported for humans for 1 h. After single PO administration, plasma concentrations of TAP would not conform to software algorithms and the PK parameters were not calculated. TAP concentration following multiple PO doses at 5 mg/kg for 5 d was found to be higher and more persistent (12 h vs. 7 h) in yolk compared with albumen. 4. This is the first PK study on the novel atypical opioid TAP in laying hens. Further studies are required to investigate the analgesic efficacy and actual effective plasma concentration of TAP in this species.

Interactions between sire family and production environment (temperate vs. tropical) on performance and thermoregulation responses in growing pigs

The aim of this study was to evaluate the effect of 2 climatic environments (temperate [TEMP] vs. tropical humid [TROP]) on production and thermoregulation traits in growing pigs. A backcross design involving Large White (LW; heat sensitive) and Creole (CR; heat tolerant) pigs was studied. The same 10 F LW × CR boars were mated with related LW sows in each environment. A total of 1,298 backcross pigs ( = 634 pigs from 11 batches for the TEMP environment and = 664 pigs from 12 batches for the TROP environment) were phenotyped on BW (every 15 d from wk 11 to 23 of age), voluntary feed intake (ADFI, from wk 11 to 23), backfat thickness (BFT; at wk 19 and 23), skin temperature (ST; at wk 19 and 23), and rectal temperature (RT; at wk 19, 21, and 23). The feed conversion ratio was computed for the whole test period (11 to 23 wk). The calculation of the temperature-humidity index showed an average difference of 2.4°C between the TEMP and TROP environments. The ADG and ADFI were higher in the TEMP environment than in the TROP environment (834 vs. 754 g/d and 2.20 vs. 1.80 kg/d, respectively; < 0.001). Body temperatures were higher in the TROP environment than in the TEMP environment (35.9 vs. 34.8°C for ST and 39.5 vs. 39.3°C for RT, respectively; < 0.001). Most of the studied traits (i.e., BW, BFT, ADG, ADFI, and RT) were affected by sire family × environment interactions ( < 0.05), resulting in "robust" and "sensitive" families. Our results show a family dependency in the relationships between heat resistance and robustness, suggesting the possibility of finding genotypes with high production and low heat sensitivity. Further research is needed to confirm the genetic × environment interaction and to detect QTL related to heat tolerance.

Plasma profile of cimicoxib in sheep after oral administration at two different rates

Sheep are often subjected to painful procedures and thus they need to be treated with analgesics. Nevertheless, knowledges about pharmacokinetic features of these drugs in this species are poor. The aim of this study was to evaluate plasma behaviour of cimicoxib in sheep after a single oral administration at two different dose rates (4 and 6 mg/kg). Maximum plasma concentrations of cimicoxib were equal to 273.78 (median value; range 189.00-567.32) and 565.01 (range 308.27-822.59) ng/mL after treatment with 4 and 6 mg/kg, respectively. The time of maximum concentration (Tmax) was achieved between 4 and 10 hours following treatment at the lower dose, and between 6 and 10 hours after the administration of the higher dose, with one sheep achieving the concentration peak at 0.75 hours. The slow absorption and the great individual variability in plasma concentration, probably due to ruminal effects, suggest that cimicoxib is not suitable for oral treatment in sheep.

Pharmacokinetic/pharmacodynamic evaluation of grapiprant in a carrageenan-induced inflammatory pain model in the rabbit

Grapiprant is the novel selective EP4 receptor inhibitor recently issued on the veterinary market for dogs affected by osteoarthritis. The aim of this study was twofold: to evaluate the pharmacokinetics and the pharmacodynamics of grapiprant in the induced inflammatory pain model in the rabbit after a single IV injection of 2 mg/kg; to compare the thermal antinociception effect after 2 mg/kg IV grapiprant, with that generated by 0.5 mg/kg meloxicam SC injected. Rabbits (n = 12) were randomly assigned to two crossover studies (single-dose, two-period crossover). The first study group A (n = 3) received a single IV dose of grapiprant at 2 mg/kg dissolved in ethanol. Group B (n = 3) received a single IV injection of ethanol (equivalent volume to grapiprant volume) at the same site. The second study group C (n = 3) received a single SC dose of meloxicam at 0.5 mg/kg. Group D (n = 3) received a single SC injection of 15% ethanol (equivalent volume to grapiprant volume) at the same site. After a 2-week washout period, the groups were rotated and the experiments repeated. Blood samples (0.7 mL) were collected from the right ear artery at assigned times and grapiprant plasma concentrations determined by a validated HPLC-FL method. Three hours prior to administration of the drugs, inflammation was induced by SC injection of lambda carrageenan (200 μL, 3% in physiological saline) under the plantar surface of the right hind paw. At a similar time to the blood collection, an infrared thermal stimuli (40 °C) was applied to the plantar surface of the rabbits' hindlimbs to evaluate the thermal withdrawal latency (TWL). The thermal antinociceptive effect was expressed as maximum possible response (% MPR). Grapiprant plasma concentrations were detectable up to the 10-h time point (concentration range 17-7495 ng/mL). The grapiprant-treated group showed a significant increase in TWL from 1 h and up to 10 h after drug administration compared to the control. In contrast, the meloxicam group showed a significant increase in TWL from 4 up to 10 h after drug administration, compared to control. The maximal MPR% was not statistically different between the grapiprant and meloxicam group from 4 to 8 h, while significant differences were shown at 1, 1.5, 2, 10 and 24 h. Given these findings, grapiprant appears to be an attractive option for antinociception in rabbits, due to its rapid onset and extended duration of effect.

Disposition of a long-acting oxytetracycline formulation in Thai swamp buffaloes (Bubalus bubalis)

The present study aimed to characterize the pharmacokinetic profile of oxytetracycline long-acting formulation (OTC-LA) in Thai swamp buffaloes, Bubalus bubalis, following single intramuscular administration at two dosages of 20 and 30 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 504 h. The plasma concentrations of OTC were measured by high-performance liquid chromatography (HPLC). The concentrations of OTC in the plasma were determined up to 264 h and 432 h after i.m. administration at doses of 20 and 30 mg/kg b.w., respectively. The C_max values of OTC were 12.11 ± 1.87 μg/mL and 12.27 ± 1.92 μg/mL at doses of 20 and 30 mg/kg, respectively. The AUC_last values increased in a dose-dependent fashion. The half-life values were 52.00 ± 14.26 h and 66.80 ± 10.91 h at doses of 20 and 30 mg/kg b.w, respectively. Based on the pharmacokinetic data and PK-PD index (T > MIC), i.m. administration of OTC at a dose of 30 mg/kg b.w once per week might be appropriate for the treatment of susceptible bacterial infection in Thai swamp buffaloes.

Pharmacokinetics of marbofloxacin in freshwater crocodiles (Crocodylus siamensis) after intravenous and intramuscular administration

To evaluate the fate and disposition of marbofloxacin (MBF) in freshwater crocodiles (Crocodylus siamensis), MBF was administered either intravenously (i.v.) or intramuscularly (i.m.) at a dosage of 2.0 mg/kg body weight. The concentrations of MBF in plasma were measured using high-performance liquid chromatography equipped with a fluorescence detector. The concentrations of MBF in the plasma were measurable up to 144 h after i.v. and i.m. administration. After the first 45 min, the mean pharmacokinetic profiles produced by the two administration routes were almost identical. No statistically significant differences in the pharmacokinetic parameters between the groups were observed. The half-life was long (about 2.5 days), the volume of distribution was large (about 1.44 L/kg), λz was small (0.01 h^-1 ), and the clearance was slow (22.6 mL/h/kg). The absolute i.m. bioavailability (F%) was 105.36%. The dose of MBF administered in this study seems to produce appropriate PK-PD parameters that predict antibacterial success for disease caused by susceptible bacteria. More studies are warranted to evaluate the likely residues after administration of multiple doses.

Pharmacokinetics of amoxicillin trihydrate in Thai swamp buffaloes (Bubalus bubalis): a pilot study

This study aimed to investigate the pharmacokinetic characteristics of amoxicillin (AMX) in Thai swamp buffaloes, Bubalus bubalis, following single intramuscular administration at two dosages of 10 and 20 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 48 h. The plasma concentrations of AMX were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The concentrations of AMX in the plasma were determined up to 24 h after i.m. administration at both dosages. The C_max values of AMX were 3.39 ± 0.18 μg/mL and 6.16 ± 0.18 μg/mL at doses of 10 and 20 mg/kg, respectively. The AUC_last values increased in a dose-dependent fashion. The half-life values were 5.56 ± 0.40 h and 4.37 ± 0.23 h at doses of 10 and 20 mg/kg b.w, respectively. Based on the pharmacokinetic data and PK-PD index (T > MIC), i.m. administration of AMX at a dose of 20 mg/kg b.w might be appropriate for the treatment of susceptible Mannheimia haemolytica infection in Thai swamp buffaloes.