Göttingen pigs as a potential model for natalizumab pharmacokinetics, pharmacodynamics, and immunogenicity evaluation.

Natalizumab is a recombinant, humanized form of a monoclonal antibody that binds to CD49d. The presented study was conducted to explore the suitability of Göttingen pigs as a pharmacokinetic/pharmacodynamic model in the preclinical phase of biosimilar natalizumab development. The minipigs were treated with 1.286 or 3.0 mg of natalizumab (Tysabri®) per kg of body weight by a single 1-hour intravenous infusion. Six days before (baseline) and 30 days after administration of the single dose of natalizumab, blood samples were taken for analysis. No signs of local or general intolerance were observed. The pharmacokinetics plot shows a biphasic profile dependent on anti-drug antibody (ADA) levels. A dose-related increase in the CD49d saturation was observed immediately after the end of the infusion. The soluble vascular cell adhesion molecule (sVCAM) concentrations of the female animals were moderately decreased immediately after the end of infusion compared to the predose levels. The soluble mucosal addressin cell adhesion molecule (sMAdCAM) concentrations were slightly decreased compared to the predose levels starting immediately after the end of infusion and lasting for the next 30 days. All animals treated appeared to produce ADA. The concentrations of the ADA ranged from 15.8 to 16,748 ng/mL Göttingen pigs represent a suitable model for pharmacokinetic analysis and mechanism of action evaluation related to saturation of CD49d.

Tolerance of Biopronil Spot on® after repeated single- or multiple-dose topical treatments in dogs.

A variety of toxic effects of fipronil (FIP), the active substance of Biopronil Spot on®, on animals and humans has been reported and raises the need to investigate the FIP toxic effects. The objectives of the study were the evaluation of the local and systemic tolerance of Biopronil Spot on® and the assessment of its influence on haematological and biochemical blood parameters after single and multiple topical treatment in dogs. Thirty-two mixed breed dogs were included in the study assessing the local and general tolerance of Biopronil Spot on® following single, triple and fivefold dose after spot-on multiple applications in dogs (on days 0, +28 and +56) at a dosage 134 mg for a dog weighing 10-20 kg and 268 mg for a dog weighing 21-40 kg. A physical examination and biochemical and haematological analyses were performed on the days of the study as follows: -14, -5, +3, +31, +59, +70. No visible pathological changes on the skin were observed. The biochemical and haematological indicators rarely exceeded the reference values. No influence of Biopronil Spot on® administered in single, triple and fivefold repeated doses on the assessed clinical, haematological and biochemical parameters in dogs was found under the conditions described in the study.

The Effect of L-Glutamine on Basal Albumen and Yolk Indices, and Albumen Amino Acids Composition.

The current study tested the hypothesis that 1.0% dietary inclusion of L-glutamine (Gln), an non-essential amino acid that influences protein synthesis, can improve internal egg quality, including amino acids profile. Thirty-week-old Bovans Brown laying hens in their middle laying period were assigned to one of the two experimental groups (12 replicate cages, 2 hens/cage) with Gln in the form of alpha-ketoglutarate (10 g/kg) or without Gln inclusion. The experimental period lasted for 30 wks, from the 31st to the 60th week of age of hens, when eggs were collected and selected egg quality indices were determined. Gln supplementation had no effect on albumen and egg yolk share, albumen and yolk basal indices and composition, including yolk cholesterol content. However, Gln decreased the lipid content of the egg albumen (p < 0.001), and influenced albumen amino acid profile, increasing content of asparagine (p < 0.05), phenylalanine (p < 0.05), proline (p < 0.001), tryptophan (p < 0.01), and tyrosine (p < 0.05). In conclusion, the study shows a potential role of Gln supplementation for enhancing nutritional values of eggs by lower lipid content and higher amino acid profile.

Ustekinumab pharmacokinetics after subcutaneous administration in swine model.

BACKGROUND: Due to multiple similarities in the structure and physiology of human and pig skin, the pig model is extremely useful for biological drug testing after subcutaneous administration. Knowledge of the differences between subcutaneous injection sites could have a significant impact on the absorption phase and pharmacokinetic profiles of biological drugs. OBJECTIVES: This study aimed to analyze the impact of administration site on pharmacokinetics and selected biochemical and hematological parameters after a single subcutaneous administration of ustekinumab in pigs. Drug concentrations in blood plasma were analyzed by enzyme-linked immunosorbent assay. Pharmacokinetic analyses were performed based on raw data using Phoenix WinNonlin 8.1 software and ThothPro v 4.1. METHODS: The study included 12 healthy, female, large white piglets. Each group received a single dose of ustekinumab given as a 1 mg/kg subcutaneous injection into the internal part of the inguinal fold or the external part of the inguinal fold. RESULTS: The differences in absorption rate between the internal and external parts of the inguinal fold were not significant. However, the time of maximal concentration, clearance, area under the curve calculated between zero and mean residence time and mean residence time between groups were substantially different (p > 0.05). The relative bioavailability after administration of ustekinumab into the external part of the inguinal fold was 40.36% lower than after administration of ustekinumab into the internal part of the inguinal fold. CONCLUSIONS: Healthy breeding pigs are a relevant model to study the pharmacokinetic profile of subcutaneously administered ustekinumab.

Quercetin affects uterine smooth muscle contractile activity in gilts.

Quercetin is a polyphenolic flavonoid occurring in leaves, stems, flowers and fruits of many plants. In traditional Chinese medicine, it is used as a natural therapeutic agent with a broad spectrum of activities (antioxidant, neuroprotective, anti-inflammatory, anticancer, antibacterial and antiviral). Moreover, quercetin affects function of the reproductive tract, however the knowledge of this activity is still fragmentary. Therefore, this study aimed to determine the influence of quercetin on the contractile activity of the porcine myometrium collected from immature (n = 6), cyclic (n = 6) and early pregnant (n = 6) gilts. Strips of the myometrium (comprising longitudinal and circular layer) were resected from the middle part of the uterine horns and the isometric contractions were recorded. After 60-90 min of preincubation, the strips were stimulated with quercetin in increasing (10-13-10-1 M) concentrations and the changes in the tension amplitude and frequency of contractions were measured. Quercetin decreased (P<0.01-0.001) the amplitude of contractions at concentrations 10-11-10-1 M and 10-10-10-1 M in cyclic and early pregnant groups, respectively. The frequency of contractions decreased in all groups but was the highest (at concentrations 10-11-10-1 M; P<0.05-0.001) in the cyclic group and the lowest (at concentrations 10-5-10-1 M; P<0.01) in the immature group. The tension decreased only in the cyclic group after quercetin administration in high concentrations (10-6-10-1 M; P<0.05-0.01). The results indicate that quercetin causes relaxation of the porcine uterine smooth muscle but this activity is strongly related to the physiological status of the gilts.

The Protective Role of Alpha-Ketoglutaric Acid on the Growth and Bone Development of Experimentally Induced Perinatal Growth-Retarded Piglets.

The effect of alpha-ketoglutaric acid (AKG) supplementation to experimentally-induced, perinatal growth-retarded piglets was examined. Sows were treated with a synthetic glucocorticoid (Gc) during the last 25 days of pregnancy, and after the birth, piglets were randomly divided into three groups depending on the treatment. The Gc/Gc + AKG and Gc/AKG groups born by Gc-treated sows after the birth were treated with Gc or Gc + AKG for 35 days. Significantly lower serum growth hormone, IGF-I, osteocalcin, leptin, and cortisol concentrations were observed in the Gc/Gc + AKG group, while the bone alkaline phosphatase activity was significantly higher. Serum insulin concentration was higher in the control group. Serum alanine, lysine, histidine, and tryptophan concentrations were higher in the Gc/Gc + AKG and Gc/AKG groups. The perinatal action of Gc significantly affects histomorphometry of articular cartilage and trabecular bone and bone mechanics. The results clearly showed that dietary AKG had positive effects with regards to the profile of free amino acids. Taking into account the function of AKG as an energy donor and stimulator of collagen synthesis, it can be concluded that the anabolic role of AKG may be the main mechanism responsible for its protective effect against the GC-induced perinatal intensified catabolic state.

Selected Biological Medicinal Products and Their Veterinary Use.

Definitions of biological medicinal products (BMPs) vary depending on the source. BMPs are manufactured using complex biological/biotechnological processes involving living cell lines, tissues and organisms such as microorganisms, plants, humans and even animals. Advances in modern biotechnological methods and genetic engineering have made it possible to search for new drugs with a targeted effect and simultaneous reduction of adverse effects, which has resulted in BMPs dynamically increasing their share in the pharmaceutical market. Currently, these drugs are widely used in the treatment of many human diseases, but an increasing number of drugs of this group are also being used in the treatment of animals, mainly in dermatology, rheumatology and oncology. This article presents the current state of knowledge in the field of biological medicinal products used in animal therapy.

Development of a UHPLC-MS/MS Method for the Determination of Quercetin in Milk and its Application to a Pharmacokinetic Study.

INTRODUCTION: Quercetin is a polyphenolic flavonoid which has been used in traditional Chinese medicine as a natural therapeutic agent with a broad spectrum of activities (antioxidant, anticancer, neuroprotective, anti-inflammatory, antiviral and antibacterial). The aim of this study was to develop and validate a rapid and simple ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method for the determination of quercetin in milk. MATERIAL AND METHODS: Sample preparation was based on a liquid-liquid extraction with 0.5% formic acid in acetonitrile. The chromatographic separation was performed on a ZORBAX SB-C18 column with methanol and 0.5% formic acid as a mobile phase. RESULTS: The procedure was successfully validated. The mean recovery of the analyte was 98%, with the corresponding intra- and inter-day variation less than 10% and 15%, respectively, and the repeatability and reproducibility were in the range of 3%-7.2% and 6.1%-12%, respectively. The lowest level of quantification was 1.0 µg/kg. CONCLUSION: The proposed method was successfully applied in evaluating the pharmacokinetics of quercetin in milk obtained from dairy cows with clinical mastitis after intramammary administration.

Fluctuations in Pharmacokinetics Profiles of Monoclonal Antibodies.

Monoclonal antibodies (mAbs) are a group of drugs with predicted slow linear and target-mediated distribution and elimination. Visual inspection of published pharmacokinetic profiles of mAbs frequently reveals plateaus in the distribution phase or an increasing concentration many days after a single intravenous dose. A question which has been left unanswered until now is whether mAbs undergo recirculation mechanisms. If so, then which mechanisms are crucial for the fluctuation in their pharmacokinetics profiles? What is the impact of such mechanisms on mAb absorption, distribution and elimination? Current commentary accounts for the fluctuation of mAbs concentrations based on different mechanisms, as well in different phases of their in vivo disposition. Current knowledge shows significant impact of mAbs lymphatic recirculation on characteristics of their pharmacokinetics profiles. Fluctuating or plateau phases in pharmacokinetic profiles of mAbs are a consequence of multiple simultaneously occurring recirculatory as well as adsorption/desorption processes rather than only slow, continuous elimination. Lymphatic recirculation as well as other mechanisms appears to be an obvious element of the mAbs disposition. Periodic changes in the key factors affecting mAbs disposition can be responsible for the unpredictable concentration peaks in absorption, distribution and the elimination phase.

Quercetin decrease somatic cells count in mastitis of dairy cows.

Quercetin is a dietary flavonoid which has an effect on inflammation, angiogenesis and vascular inflammation. In several other flavonoids (e.g. kaempferol, astragalin, alpinetin, baicalein, indirubin), anti-inflammatory mechanism was proven by using mice mastitis model. The aim of the current study was pilot analysis of quercetin tolerability and its impact on somatic cells count (SCC) after multiple intramammary treatment on dairy cows with clinical mastitis. Based on SCC and clinical investigation, 9 dairy cows with clinical mastitis of one quarter were selected for the pilot study. Baseline analysis (hematology, TNFα, SCC) was performed every 24h among all cows three days before the first dose (B1-B3). After the baseline monitoring (B1-B3) eight days treatment (D1-D8) was performed with a high and low dose. Selected blood parameters were analyzed. Starting from D1 to D8, a decrease of SCC in relation to baseline was characterized by declining trend. The presented results allowed the confirmation of the significant influence of quercetin on the reduction of SCC in mastitis in dairy cows after 8days of therapy.

Withdrawal of Amoxicillin and Penicillin G Procaine from Milk after Intramammary Administration in Dairy Cows with Mastitis.

INTRODUCTION: There are many veterinary products containing ß-lactam antibiotics which are used for mastitis treatment in cows. The aim of the study was to determine whether mastitis could have any effect on amoxicillin (AMX) or penicillin G procaine (PEN) withdrawal period from milk, in the context of current maximum residue limits established by the European Commission. MATERIAL AND METHODS: The study was conducted on 17 dairy Black and White cows with clinical mastitis during the lactation period. The first group (n = 8) received 200 mg of amoxicillin (AMX), whereas the second group (n = 9) received 200,000 IU/mg of penicillin G procaine (PEN) by intramammary administration. For the measurement of AMX and PEN concentrations in milk, the liquid chromatography tandem mass spectrometry method was applied. Pharmacokinetic calculations were performed using Phoenix WinNonlin 6.4 software. RESULTS: The determined AMX and PEN half-life values in the mammary gland suggest that the drug withdrawal is at a level of 99.9% within 81 h (≈3.5 days) and 116 h (≈5 days) after administration of AMX and PEN, respectively. The present research indicates that, at 60 h after administration, the average PEN concentration in the milk from cows with clinical signs of mastitis may still reach 4.96 g/kg and that of AMX can even be 6.92 g/kg. CONCLUSION: The results obtained confirm that, in mastitis cases, a 72-h withdrawal period is sufficient for elimination of AMX to a lower level than the established maximum residue limit (MRL) values. However, in the case of PEN, at 69 h after administration, the drug concentration may be close to that of the determined MRL.

The using of a piglets as a model for evaluating the dipyrone hematological effects.

BACKGROUND: Dipyrone (MET, metamizole) is a non-steroidal anti-inflammatory drug commonly used both in human and in veterinary medicine. After oral administration, is broken down rapidly to metabolites which largely retain the activity of the parent drug. Its metabolites have analgesic, antipyretic and anti-inflammatory effects. RESULTS: The subjects were eight healthy male Large White post-suckling piglets, weighing between 5.0 to 7.4 kg, of ages 35 ± 10 days. The animals were administered MET (100 mg/kg) by an intramuscular (I.M.) injection. The study calculated the value of several hemorheological parameters. Significant impact of MET treatment (p < 0.05) was proven in case: activated partial thromboplastin time; ratio of activated partial thromboplastin time; hemoglobin; hematocrit; mean corpuscular hemoglobin; mean corpuscular volume; red blood cells volume; white blood cells volume; prothrombin time index. CONCLUSIONS: In summation, our observations suggest that a piglet model is useful for studying the impact of MET on hemorheological parameters.