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Immature Animals (immature + animals)
Selected AbstractsImmediate and Delayed Benefits of Play Behaviour: New Evidence from Chimpanzees (Pan troglodytes)ETHOLOGY, Issue 12 2004E. Palagi Evidence for the anticipation of competition at feeding time has been previously documented in both Pan species. Chimpanzees seem to cope with competitive tendency through behavioural mechanisms of tension reduction, and grooming is certainly one of these. Social play and grooming are often matched because they bring animals into close physical contact for long periods, and they have an important role in social cohesion. Our goal was to investigate the occurrence of play behaviour during the pre-feeding period, before a basic maintenance activity is about to take place, in the chimpanzee colony housed in the ZooParc de Beauval (St Aignan sur Cher, France). The group was composed of 10 adults and nine immature individuals. By scan animal sampling (344 h of observation), we recorded play and grooming interactions in all age-class combinations during four different periods (pre-feeding, feeding, post-feeding, control). We found peak levels of grooming interactions among adults during the pre-feeding time. A peak frequency at the pre-feeding time was also found in social play between adults and unrelated immature subjects. This finding suggests that during high tension periods, grooming and play might share similar functions in conflict management. Like grooming, play might have an important role to limit aggression and increase tolerance around food (immediate benefits). Immature animals showed a higher frequency of play in the pre-feeding than in any other condition (feeding, post-feeding, and control). During high excitement periods social play probably represents a safe mechanism for immature subjects to test their personal abilities (self-assessment), the strength/weakness of playmates, and the degree of cooperation/competition with them (social-assessment). In the light of this new evidence, we can assert that play behaviour is far from being a purposeless activity, at least in the chimpanzee colony under study. [source] Effects of Antiepileptic Drugs on Refractory Seizures in the Intact Immature Corticohippocampal Formation In VitroEPILEPSIA, Issue 11 2003Pascale Paule Quilichini Summary:,Purpose: We developed a new in vitro preparation of immature rats, in which intact corticohippocampal formations (CHFs) depleted in magnesium ions become progressively epileptic. The better to characterize this model, we examined the effects of 14 antiepileptic drugs (AEDs) currently used in clinical practice. Methods: Recurrent ictal-like seizures (ILEs, four per hour) were generated in intact CHFs of P7,8 rats, and extracellular recordings were performed in the hippocampus and neocortex. AEDs were applied at clinically relevant concentrations (at least two), during 30 min after the third ILE. Their ability to prevent or to delay the next ILE was examined. Results: Valproic acid and benzodiazepines (clobazam and midazolam) but also phenobarbital and levetiracetam prevent the occurrence of seizures. In contrast, usual concentrations of carbamazepine (CBZ), phenytoin, vigabatrin, tiagabine, gabapentin, lamotrigine (LTG), topiramate, felbamate, and ethosuximide did not suppress ILEs. In addition, LTG and CBZ aggravate seizures in one third of the cases. Conclusions: This intact in vitro preparation in immature animals appears to be quite resistant to most AEDs. Blockade of seizures was achieved with drugs acting mainly at the ,-aminobutyric acid (GABA)A -receptor site but not with those that increase the amount of GABA. Drugs with a broad spectrum of activity are efficient but not those preferentially used in partial seizures or absences. We suggest that this preparation may correspond to a model of epilepsy with generalized convulsive seizures and could be helpful to develop new AEDs for refractory infantile epilepsies. [source] Fore limb bones of late Pleistocene dwarf hippopotamuses (Mammalia, Cetartiodactyla) from Madagascar previously determined as belonging to the crocodylid Voay Brochu, 2007FOSSIL RECORD-MITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE, Issue 2 2010Oliver Hampe Abstract A humerus and two radii of juvenile dwarf hippopotamuses are redescribed. The subfossil bones from the collection of the Museum für Naturkunde Berlin were erroneously assigned to the horned crocodile Voay robustus (Grandidier & Vaillant, 1872) by Bickelmann & Klein (2009). All three limb bones presented here belong to immature animals. The epiphyses are not fused, except the proximal extremity of the right radius; and the radius and ulna are also unfused. The two radii are from individuals of different size, whereas the left radius and the humerus are from animals of similar size. Morphologically, the limb bones cannot be identified to species level. A tentative assignment to Hippopotamus madagascariensis is discussed based on the knowledge of the geographic origin on the island. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The effect of skeletal maturity on the regenerative function of intrinsic ACL cellsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2010Ashley N. Mastrangelo Abstract Anterior cruciate ligament (ACL) injuries are an important clinical problem, particularly for adolescent patients. The effect of skeletal maturity on the potential for ACL healing is as yet unknown. In this study, we hypothesized that fibroblastic cells from the ACLs of skeletally immature animals would proliferate and migrate more quickly than cells from adolescent and adult animals. ACL tissue from skeletally immature, adolescent, and adult pigs and sheep were obtained and cells obtained using explant culture. Cell proliferation within a collagen,platelet scaffold was measured at days 2, 7, and 14 of culture using AM MTT assay. Cellular migration was measured at 4 and 24 h using a modified Boyden chamber assay, and cell outgrowth from the explants also measured at 1 week. ACL cells from skeletally immature animals had higher proliferation between 7 and 14 days (p,<,0.01 for all comparisons) and higher migration potential at all time points in both species (p,<,0.01 for all comparisons). ACL cells from skeletally immature animals have greater cellular proliferation and migration potential than cells from adolescent or adult animals. These experiments suggest that skeletal maturity may influence the biologic repair capacity of intrinsic ACL cells. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:644,651, 2010 [source] Healing of subfailure ligament injury: comparison between immature and mature ligaments in a rat modelJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2002Paolo P. Provenzano This study evaluated biomechanical properties of healing ligament following subfailure (grade II) injury by comparing young and mature animals in a rat lateral collateral ligament (LCL) model. One randomly selected LCL was stretched in situ using a custom designed device in eighteen young (21 days) and eighteen skeletally mature (8 months) male rats. Animals were euthanized at 0, 7, and 14 days post-surgery, and ligament ultimate stress, strain at failure and laxity were determined (n = 6 pairs per group). At time 0 after introduction of stretch injury, ligament laxity was present in both groups. The mature rats had 54 ± 9% strength of the control while the immature rats had 58 ± 11% of the strength of the control, representing a consistent and significant injury. The immature and mature ligaments showed similar patterns of cellular damage post-injury and had similar modes of mechanical failure. Ligament laxity decreased in each group as healing time increased, however ligament laxity did not completely recover in either group after 2 weeks of healing. After 7 and 14 days of healing, the mature rats, respectively, had only 63 ± 14% and 80 ± 8% strengths of the controls while the immature rats had 94 ± 6% and 94 ± 10%. Hence, mechanical data showed that immature animals recovered their strength after a grade II sprain at a faster rate than mature animals. However, ligament laxity was still present in both groups two weeks after the injury and was not completely removed by growth in the immature group. These findings are clinically relevant since joint laxity after injury is common, and these results may explain the presence of continued instability in a joint injured at a young age. Hence, this study, with a new injury model, showed differences in ligament healing associated with maturity and quantified the clinically observed persistance of ligament laxity. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Pharmacokinetics of flubendazole and its metabolites in lambs and adult sheep (Ovis aries)JOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2009Flubendazole (FLU) is indicated for control of helminthoses in pig and avian species (monogastric animals) and its corresponding pharmacokinetics are well known. The information on FLU's pharmacokinetic behavior in animal species with forestomach (ruminants) has been limited although the use of FLU in these species could be beneficial. The aim of this study was to investigate the pharmacokinetics of FLU and its main metabolites in sheep. The effects of animal age (sexually immature and mature ones) and gender were also studied. FLU was orally administered in a single experimental dose (30 mg/kg of body weight) in the form of oral suspension. Treated immature animals (aged 3 months) and 5 months later the same mature individuals (aged 8 months) were kept under the same conditions (food, water and management) and treated with FLU. Within 72 h after FLU administration, plasmatic samples were collected and FLU and its Phase I metabolites were quantified using high-performance liquid chromatography. FLU was detected in very low concentrations only, reduced FLU (FLU-R) was identified as the main metabolite, and hydrolyzed FLU (FLU-H) as the minor one. Formation of FLU-R was stereospecific with (+)-FLU-R domination. The plasmatic concentrations of (+)-FLU-R reached 10,15 times higher values than those of FLU, (,)-FLU-R and FLU-H. A significant gender effect on pharmacokinetics of FLU or (+)-FLU-R metabolite in the mature animals was found and a wide significant difference between lambs and adult sheep in FLU including both metabolites has been proved. [source] Blubber testosterone: A potential marker of male reproductive status in short-beaked common dolphinsMARINE MAMMAL SCIENCE, Issue 3 2009Nicholas M. Kellar Abstract A novel molecular technique was used to measure blubber testosterone (BT) in 114 male short-beaked common dolphins, Delphinus delphis, collected from incidental fishery bycatch and strandings. When these concentrations were compared across maturity states, the mean (± SEM) BT levels of mature D. delphis (14.3 ± 3.0 ng/g) were significantly higher than those of pubertal (2.5 ± 0.5 ng/g, P= 0.006) and immature animals (2.2 ± 0.3 ng/g, P < 0.0001). BT concentrations in mature males were significantly higher in summer months (53.9 ± 2.0 ng/g) than during the rest of the year (7.9 ± 0.69 ng/g, P < 0.0001), indicating reproductive seasonality. An analysis of BT in different anatomical locations showed that hormone concentrations were not homogenous throughout the body; the levels in the dorsal fin were significantly lower than in most other areas (F= 5.39, P= 0.043). Conversely, we found no significant differences in BT concentration with respect to subepidermal depth (F= 2.09, P= 0.146). Finally, testosterone levels in biopsies from 138 free-swimming male D. delphis, of unknown maturity state, sampled off California were found to be of concentrations similar to those from the fishery bycatch and stranding samples and revealed an analogous trend with respect to ordinal date. [source] BILATERAL DIRECTIONAL ASYMMETRY OF THE APPENDICULAR SKELETON OF THE HARBOR PORPOISE (PHOCOENA PHOCOENA)MARINE MAMMAL SCIENCE, Issue 3 2005Anders Galatius Abstract Directional asymmetry (DA) of the lengths, diameters, and masses of the scapula, humerus, radius, and ulna were analyzed on a sample of 213 harbor porpoises from Denmark and West Greenland. The levels of DA were consistent across yearlings and older animals, mature and immature animals, sexes, and populations. All investigated variables showed significant DA favoring the right side. For the pooled sample, DA of lengths ranged from 0.2% SE 0.1 (ulna) to 1.2% SE 0.1 (scapula). DAs of diameters were 1.5% SE 0.2 for the humerus, 0.6% SE 0.1 for the radius, and 1.3% SE 0.2 for the ulna. DA of mass ranged from 2.8% SE 0.5 (humerus) to 4.3% SE 0.7 (ulna). The humerus and ulna had significantly larger mean diameter/ length ratios on the right side than the left, making them more robust. The large DA of scapula length indicates larger muscle mass associated with the right flipper, while the generally more robust right humerii and ulnae may be designed for higher levels of mechanical stress. These DAs and the examples of lateralized behavior recorded in cetaceans, point to the existence of lateralized use of the flippers at the population level in harbor porpoises and possibly other cetacean species. [source] | |||||||||||||