Improving cold storage of subitaneous eggs of the copepod Acartia tonsa Dana from the Gulf of Mexico (Florida – USA)

Developing methods to store copepod eggs is necessary to increase the availability of copepods as a live food for the aquaculture industry and aquarium trade, and also to allow the exchange of copepods between researchers. The present study, evaluated the effect of glucose and two antibiotics (kanamycin sulphate and oxytetracycline HCl) on extending the shelf life of cold-stored subitaneous Acartia tonsa eggs. Also, egg development effects on the survival of the eggs were tested. Glucose did not have any significant effects on the survival of the eggs. However, the addition of antibiotics to the storage vials resulted in an increase of the survival of the eggs. In the best case, the shelf life of the eggs was almost doubled. After 7 days, the kanamycin+glucose treatment led to a hatching success of 86±1% of the hatchable eggs, while the untreated eggs presented a hatching success of 47±6%. However, long exposure to high concentrations of antibiotics was lethal to the copepod eggs. After more than 30 days of exposure to 100 mg L⁻¹ of oxytetracycline, the survival of the eggs was lower than in the untreated samples. After 45 days, oxytetracycline-treated eggs (100 mg L⁻¹) presented a hatching success of 4–5% while the non-stored eggs still had a hatching success of 9%, and the eggs treated with a lower concentration of antibiotics (10 mg L⁻¹) showed a hatching success up to 21–23%. The size of the nauplii in all trials tended to decrease as the period of cold storage at 1°C increased. We consider that the use of antibiotics at the right dosage to be a means to increase the storage capacity of the Gulf of Mexico strain of A. tonsa eggs, which do not show any capacity to be stored for long periods of time, compared with some other strains. In addition eggs that were between 5 and 7 h old survived longer when stored in the cold than eggs, which were freshly spawned or closer to hatching.     

Effect of pre-medication on gastroduodenoscopy in isoflurane-anesthetized cats

The pre‐medicant chosen may influence the ease with which gastroduodenoscopy (GD) is performed. The purpose of this study was to evaluate the relative ease of GD in cats under ketamine and isoflurane anesthesia after IM injection of hydromorphone (H, 0.1 mg kg^?1), hydromorphone plus glycopyrrolate (HG, 0.1 mg kg^?1 (H), 0.01 mg kg^?1 (G)), medetomidine (M, 0.03 mg kg^?1), or butorphanol (B, 0.4 mg kg^?1). Eight cats were assigned randomly to receive each treatment in a cross‐over design with at least 7 days between treatments. Twenty minutes after pre‐medication, medetomidine produced greater (p = 0.001) sedation than the other treatments when assessed, using a subjective ordinal scale. The cats were injected with ketamine (10 mg kg^?1 IM), orotracheally intubated, connected to a pediatric circle breathing system, and allowed to spontaneously breathe isoflurane in oxygen. Once end‐tidal isoflurane concentration was stable at 1.4% for 15 minutes, endoscopy was started. A single endoscopist (REG), who was unaware of the treatment used, performed all endoscopies. The endoscopist scored the difficulty of endoscopy subjectively (0–3). The significance of differences between treatments was evaluated using Friedman's test. Time for entering the stomach was 9.4 (4.7–15.9) (median (minimum–maximum)), 6.6 (5.2–11.7), 8.4 (6.3–16.5), and 7.7 (5.1–14.7) seconds and for entering the duodenum from the stomach was 20.5 (13.8–40.9), 18.2 (10.3–39.8), 20.2 (16.2–119.5), and 22.2 (11.8–83.8) seconds for H, HG, M, and B treatments, respectively. There were no significant differences in the time for, or difficulty of, endoscopy. We conclude that any of these drugs can be used satisfactorily at the doses and combinations tested to pre‐medicate cats prior to general anesthesia for GD.     

Neurological diseases of ruminant livestock in Australia. II: toxic disorders and nutritional deficiencies

The second in this series of clinical reviews on neurological diseases in ruminant livestock in Australia examines toxic disorders associated with plant and microbial toxins as well as the neurological effects of vitamin and mineral deficiencies. The aim of these reviews is to assist in the surveillance of neurological diseases, especially the transmissible spongiform encephalopathies.     

Pharmacokinetics,pharmacodynamics, toxicology and therapeutics of mavacoxib in the dog: a review

Mavacoxib is a novel nonsteroidal anti‐inflammatory drug (NSAID), with a preferential action on the cyclooxygenase (COX)‐2 isoform of COX and a long duration of action. It is classified chemically as a member of the sulphonamide subgroup of coxibs. Mavacoxib is highly lipid but very poorly water soluble. In the dog, the pharmacokinetic (PK) profile comprises very slow body clearance, long elimination half‐life and a relatively large distribution volume. Biotransformation and renal excretion are very limited, and elimination occurs primarily by biliary secretion and excretion of unchanged drug in faeces. The PK profile of mavacoxib differs quantitatively between young healthy dogs (Beagles and mongrels) and clinical cases with osteoarthritis (OA). In OA dogs, mavacoxib exhibits a much longer terminal half‐life, associated principally with their greater median body weight compared with dogs used in preclinical studies. There is also some evidence of breed differences and a small effect of age on mavacoxib PK in the OA canine population. The pharmacodynamics (PD) of mavacoxib has been established: (i) in whole blood assays at the molecular level (inhibition of COX‐1 and COX‐2 isoforms); (ii) in preclinical models of inflammation and pain; and (iii) in clinical OA subjects treated with mavacoxib. The dosage schedule of mavacoxib for clinical use has been determined by owner and veterinary clinical assessments and is supported by integration of PK and PD preclinical data with clinical responses in canine disease models and in dogs with naturally occurring OA. The dosage regimen has been further confirmed by correlating levels of inhibition of COX isoforms in in vitro whole blood assays with plasma concentrations of mavacoxib achieved in OA dogs. In addition to the specific properties of mavacoxib, some general aspects of the PK and PD of other agents of the NSAID group, together with pathophysiological and clinical aspects of OA, are reviewed, as a basis for correlating with the safety and efficacy of mavacoxib in therapeutic use. Integration of PK and PD data suggests that the recommended dosage regimen of 2 mg/kg bw once for 14 days, followed by administration at monthly intervals, is optimal from both efficacy and safety perspectives and is further confirmed by clinical field studies.     

Effects of a controlled-release albendazole capsule on parasitism and production from grazing Merino ewes and lambs

SUMMARY: Effects of a controlled-release albendazole capsule (CRC) on nematode parasitism and production of Merino ewes and lambs were Investigated in a replicated grazing experiment between August 1986 and July 1989. The experiment was conducted on a site where the naturally occurring parasites were benzimidazole-resistant, with double the recommended dose of oxfendazole reducing faecal egg counts of Trichostrongylus colubriformis by less than 50%. Two CRC treatments were compared with a minimal treatment control and the widely-used strategic control program, Wormkill.
Egg counts and worm burdens of major parasite species of ewes and of lambs before and after weaning were significantly reduced by use of the CRC in ewes before lambing or in lambs at weaning. These parasitological effects were reflected in increased productivity of CRC ewes and lambs. Ewes given CRCs lost less weight and grew more wool during lactation than ewes given Wormkill or control treatments, while their lambs gained more weight and had heavier fleeces than lambs from Wormkill or control treatments. Where lambs were weaned by removing ewes from the lambing paddock, administration of the CRC at weaning to lambs whose dams had also been treated with the CRC did not result in improved production when compared with lambs from ewes dosed with CRCs and treated after weaning according to the Wormkill program. Some possible uses for the CRC in ewes and lambs were identified.     

Nitrogen Sources and Adventitious Root Development in Eucalyptus globulus Microcuttings

In previous studies, it has been shown that nitrate supply may favor adventitious rooting in the rooting recalcitrant Eucalyptus globulus. Herein, the impact of various N sources on adventitious rooting and root branching in microcuttings of E. globulus was investigated. The positive effect of nitrate on adventitious root development was confirmed and extended to root branching. Urea yielded a rooting response comparable to that observed in presence of nitrate. Urease activity was observed, displaying two peaks: one at the root induction and another at the root formation step. The use of glutamic acid, glutamine or asparagine promoted higher root number, but yielded shorter roots. Rooted microcuttings derived from all nitrogen (N) sources were successfully acclimated to ex vitro conditions. The manipulation of N sources in adventitious rooting media can be a tool for improving new root density, length and branching in this species.     

Solid fraction of separated digestate as soil improver: implications for soil fertility and carbon sequestration

Journal of Soils and Sediments - This study investigated the C and N mineralisation potential of solid fractions (SFs) from co-digestated pig manure after P-stripping (P-POOR SF) in comparison with...     

Grape Seed and Tea Extracts and Catechin 3-Gallates Are Potent Inhibitors of α-Amylase and α-Glucosidase Activity

This study evaluated the inhibitory effects of plant-based extracts (grape seed, green tea, and white tea) and their constituent flavan-3-ol monomers (catechins) on α-amylase and α-glucosidase activity, two key glucosidases required for starch digestion in humans. To evaluate the relative potency of extracts and catechins, their concentrations required for 50 and 90% inhibition of enzyme activity were determined and compared to the widely used pharmacological glucosidase inhibitor, acarbose. Maximum enzyme inhibition was used to assess relative inhibitory efficacy. Results showed that grape seed extract strongly inhibited both α-amylase and α-glucosidase activity, with equal and much higher potency, respectively, than acarbose. Whereas tea extracts and catechin 3-gallates were less effective inhibitors of α-amylase, they were potent inhibitors of α-glucosidase. Nongallated catechins were ineffective. The data show that plant extracts containing catechin 3-gallates, in particular epigallocatechin gallate, are potent inhibitors of α-glucosidase activity and suggest that procyanidins in grape seed extract strongly inhibit α-amylase activity.     

Late Pleistocene Desiccation of Lake Victoria and Rapid Evolution of Cichlid Fishes

Lake Victoria is the largest lake in Africa and harbors more than 300 endemic species of haplochromine cichlid fish. Seismic reflection profiles and piston cores show that the lake not only was at a low stand but dried up completely during the Late Pleistocene, before 12,400 carbon-14 years before the present. These results imply that the rate of speciation of cichlid fish in this tropical lake has been extremely rapid.