Hindlimb Bones Research Articles

Comparative characteristics of metatarsal bones (Ossa metatarsi) and finger articles (Ossa digitorum pedis seu phalanges digitorum) of roe deer (Capreolus capreolus) and sheep (Ovis aries) in orderto determine animal species

Metatarsal bones and finger articles of roe deer and sheep are rarely used for animal identification. In practice there are frequent cases where on a corpse the head and distal parts of the limbs are missing. That is in order to prevent the identification of the bones, by which it is easiest to determine the animal species. For identification of metatarsal bones (Ossa metatarsi) as well as finger articles (Os?sa digitorum pedis seu phalanges digitorum) there were used distal parts of hindlimb bones, taken from 6 roe deers and 7 sheep. Afer the separation from the soft tissues, the bones were boiled in an autoclave, and for bleaching and degreasing they were kept in 3% solution of hydrogen peroxide (H2O2). The bones were air dried, and then photographed. In roe deer, four metatarsal bones are developed: the second (Os metatarsale secundum), the third (Os metatarsale tertium), the fourth (Os metatarsale quartum) and the fifth (Os metatarsale quintum). In sheep, the third (Os metatarsale tertium) and the fourth (Os metatarsale quartum) metatarsal bones are developed. Both in roe deer and sheep, the third and the fourth metatarsal bones are fused into one single bone - main metatarsal bone. In sheep, on dorsal and plantar side of these bones there are grooves which are more shallow and wider than in roe deer. In roe deer, hindlimbs have four fingers, and in sheep two. In roe deer there is also the difference in the number of articles on the second and fifth finger. In this animal the second and fifth finger have coalesced the first and second article (Ph1 + Ph2) and the third article(Ph3). Based on the third article of the third and fourth finger, it may be distinguished one animal from another. Margo solearis in roe deer is peaky and in sheep it is blunt. In roe deer Processus extensorius is peaky on Margo coronalis, while in shee it is blunt. In the cases when material (fresh meat, blood, hair) necessary for some laboratory methods is missing, there is used the method of animal species determination based on morphological differences between the bones of these two animals. By this method it can be with certainty determined which animal the bones belong to.

Alendronate does not prevent long bone fragility in an inactive rat model.

The lack of estrogen and inactivity are both important in the pathogenesis of osteoporosis in elderly women, and there have been no appropriate rodent studies to examine the effects of common bisphosphonates on these two components separately. We compared the efficacy of alendronate (ALN) on the long bones of aged female rats, which were sedentary, estrogen deficient, or both. The rats were either forced to remain in a sitting position or allowed to walk in standard cages with or without ALN administration. The 8-week experimental period began 5weeks after ovariectomy or sham surgery. Parameters of the hindlimb bones were determined by a three-point bending test, peripheral quantitative computed tomography, microfocus computed tomography, confocal laser Raman microspectroscopy, and dynamic histomorphometry. Regardless of ovariectomy, ALN was ineffective against the deterioration of breaking stress caused by sitting even though the trabecular bone mineral density was significantly higher in the sitting-ALN groups. Toughness was significantly deficient in the ovariectomy sitting-ALN group. This was in agreement with the bone geometry with a greater marrow space. Sitting also increased the mineral-to-matrix ratio and the carbonate-to-phosphate ratio, both indicative of aged bone. A greater loss of proteinaceous amide intensity compared with mineral intensity resulted in an increased mineral-to-matrix ratio in the presence of ALN. Sitting resulted in deficits in the quality and the geometry of cortical bone, resulting in fragility. The use of bisphosphonates, such as ALN, may provide a therapy best suited for osteoporotic individuals whose daily activity is not limited.

Bone histology in extant and fossil penguins (Aves: Sphenisciformes).

Substantial changes in bone histology accompany the secondary adaptation to life in the water. This transition is well documented in several lineages of mammals and non-avian reptiles, but has received relatively little attention in birds. This study presents new observations on the long bone microstructure of penguins, based on histological sections from two extant taxa (Spheniscus and Aptenodytes) and eight fossil specimens belonging to stem lineages (†Palaeospheniscus and several indeterminate Eocene taxa). High bone density in penguins results from compaction of the internal cortical tissues, and thus penguin bones are best considered osteosclerotic rather than pachyostotic. Although the oldest specimens sampled in this study represent stages of penguin evolution that occurred at least 25million years after the loss of flight, major differences in humeral structure were observed between these Eocene stem taxa and extant taxa. This indicates that the modification of flipper bone microstructure continued long after the initial loss of flight in penguins. It is proposed that two key transitions occurred during the shift from the typical hollow avian humerus to the dense osteosclerotic humerus in penguins. First, a reduction of the medullary cavity occurred due to a decrease in the amount of perimedullary osteoclastic activity. Second, a more solid cortex was achieved by compaction. In extant penguins and †Palaeospheniscus, most of the inner cortex is formed by rapid osteogenesis, resulting an initial latticework of woven-fibered bone. Subsequently, open spaces are filled by slower, centripetal deposition of parallel-fibered bone. Eocene stem penguins formed the initial latticework, but the subsequent round of compaction was less complete, and thus open spaces remained in the adult bone. In contrast to the humerus, hindlimb bones from Eocene stem penguins had smaller medullary cavities and thus higher compactness values compared with extant taxa. Although cortical lines of arrested growth have been observed in extant penguins, none was observed in any of the current sampled specimens. Therefore, it is likely that even these 'giant' penguin taxa completed their growth cycle without a major pause in bone deposition, implying that they did not undergo a prolonged fasting interval before reaching adult size.

Preliminary assessment of bone histology in the extinct elephant bird Aepyornis (Aves, Palaeognathae) from Madagascar

Aepyornis, a giant subfossil ratite from Madagascar, shows a well-preserved bone histology. Hindlimb bones exhibit an extensive histodiversity; the cortex is initially made of fibrolamellar, well-vascularized primary bone that modulates locally into plexiform or laminar patterns. Lines of arrested growth are generally weakly expressed. Haversian reconstruction can be complete. Perimedullar endosteal deposition is variable but can be extensive. The complex causality (phylogenetic, systematic, ontogenetic and functional… factors) involved in the production of the observed data is discussed.

Association Between The Shapes of Hindlimb Bone Articular Faces And Locomotor Behaviors in Artiodactyls

Habitat plays a role in selection for successful predator‐escape behaviors. Mammals that live in open habitats can use long‐distance running to escape predators, but in more closed habitats they would encounter barriers that require them to trade off speed for maneuverability. We examined differences in limb proportions of 31 living species of artiodactyls from various habitats (n = 94)—including species from grasslands, forests, forest‐edge habitats, and montane areas—along with some Eocene‐age artiodactyls. We examined articular faces of hindlimb bones and compared them with these species' habitats. We interpreted differences in limb morphology to be related to each species' habitat, due to selection for divergent predator‐escape behaviors. Visual differences in the shape of the proximal end of the tibia were recognized to be distinct for each of the habitats studied, but the shape of the distal end of the femur was not noticeably related to habitat. Species that lived in more open habitats had a broader tibial tuberosity and a more rounded articular margin for the femoral condyles. In contrast, species in closed habitats tended to have more pointed tuberosities with a jagged condylar margin. Mountain species were variable in the shape of the tibial tuberosity with a distinctly posterior orientation to the condyles. Closed/edge habitats had the shortest tuberosities and the most rounded condyles. Our Eocene artiodactyls showed morphologies that reflected closed and closed‐edge habitats.

MBTPS1/SKI-1/S1P proprotein convertase is required for ECM signaling and axial elongation during somitogenesis and vertebral development†.

Caudal regression syndrome (sacral agenesis), which impairs development of the caudal region of the body, occurs with a frequency of about 2 live births per 100 000 newborns although this incidence rises to 1 in 350 infants born to mothers with gestational diabetes. The lower back and limbs can be affected as well as the genitourinary and gastrointestinal tracts. The axial skeleton is formed during embryogenesis through the process of somitogenesis in which the paraxial mesoderm periodically segments into bilateral tissue blocks, called somites. Somites are the precursors of vertebrae and associated muscle, tendons and dorsal dermis. Vertebral anomalies in caudal regression syndrome may arise through perturbation of somitogenesis or, alternatively, could result from defective bone formation and patterning. We discovered that MBTPS1/SKI-1/S1P, which proteolytically activates a class of transmembrane transcription factors, plays a critical role in somitogenesis and the pathogenesis of lumbar/sacral vertebral anomalies. Conditional deletion of Mbtps1 yields a viable mouse with misshapen, fused and reduced number of lumbar and sacral vertebrae, under-developed hind limb bones and a kinky, shortened tail. We show that Mbtps1 is required to (i) maintain the Fgf8 'wavefront' in the presomitic mesoderm that underpins axial elongation, (ii) sustain the Lfng oscillatory 'clock' activity that governs the periodicity of somite formation and (iii) preserve the composition and character of the somitic extracellular matrix containing fibronectin, fibrillin2 and laminin. Based on this spinal phenotype and known functions of MBTPS1, we reason that loss-of-function mutations in Mbtps1 may cause the etiology of caudal regression syndrome.

Osteohistological variation in growth marks and osteocyte lacunar density in a theropod dinosaur (Coelurosauria: Ornithomimidae).

BackgroundOsteohistological examinations of fossil vertebrates have utilized a number of proxies, such as counts and spacing of lines of arrested growth (LAGs) and osteocyte lacunar densities (OLD), in order to make inferences related to skeletochronology and mass-specific growth rates. However, many of these studies rely on samplings of isolated bones from single individuals. These analyses do not take individual variation into account, and as a result may lead to misleading inferences of the physiology of extinct organisms. This study uses a multi-element, multi-individual sampling of ornithomimid dinosaurs to test the amount of individual variation in the aforementioned osteohistological indicators. Based on these results we also assess the conclusions of previous studies that tested paleohistological hypotheses using isolated elements.ResultsLAG number was found to be consistent within the hind limb bones of each individual, with the exception of the fibula, which preserves one additional LAG. Considerable differences in LAG spacing were found between elements of the sampled individuals, with larger variation found in elements of the foot compared with the femur, fibula, and tibia. Osteocyte lacunar density ranged between 29000 and 42000 osteocyte lacunae per mm3, and was found to vary more between hind limb bones of an individual and within bones, than between the average values of individuals.ConclusionsThe variation between hind limb elements in LAG number and LAG spacing suggests that direct comparisons of these elements may be misleading, and that LAG spacing is not a reliable proxy for mass-specific growth rates of an individual. Sampling of multiple bones should be performed as an internal check of model-based LAG retro-calculation and growth equations. The observation that osteocyte lacunar density varies more between individual bone elements than between average individual values suggests that the choice of sampled element can greatly influence the result, and care should be taken to not bias interpretations of the physiology of fossil tetrapods.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-014-0231-y) contains supplementary material, which is available to authorized users.

Exercise Training Augments Regional Bone and Marrow Blood Flow during Exercise

The principal nutrient artery to the femur demonstrates an increase in nitric oxide-mediated vasodilation in rats after treadmill exercise training. The present study sought to determine whether exercise training improves hindlimb bone and marrow blood flow distribution at rest and during exercise. Six 8-month old male Sprague-Dawley rats were exercise trained (ET) with treadmill walking at 15 m · min(-1) up a 15° incline for 60 min · d(-1) over a 10- to 12-wk period. Sedentary (SED) control animals were acclimated to treadmill exercise for 5 min · d(-1) during the week preceding the blood flow measurements. Blood flow to nine distinct regions of the femur, tibia, and fibula was determined at rest and during low-intensity exercise (15 m · min(-1) walking, 0° incline) using the reference sample microsphere method. The results demonstrate an augmentation of exercise hyperemia above that observed in SED rats during exercise in only one region of the bone, the femoral diaphysis, of ET rats. However, whereas exercise hyperemia occurred in three of the nine hindlimb bone regions measured in SED rats, exercise hyperemia occurred in seven of nine regions in ET rats. These data indicate an increase in generalized hindlimb bone and marrow blood flow during physical activity after a period of exercise training. Elevations in regional bone and marrow blood flow after training may augment medullary pressure and bone interstitial fluid flow, thus benefiting bone integrity.

A crucial role of IL-17 in bone resorption during rejection of fresh bone xenotransplantation in rats.

Bone grafting is a very useful approach to reconstruction of skeletal defects. However, the clinical use of autografts, allografts, and synthetic products is associated with a number of problems. The use of bone xenotransplantation, on the other hand, is associated with strong immune response, and therefore clear understanding of the mechanisms of immune rejection is essential. In this study, we used rabbit-to-rat xenotransplantation model to investigate the role of IL-17, and the relationship between IL-17, IL-23 and RANKL in inflammatory response during the bone grafting. Rabbit hindlimb bone was transplanted to rats, and half of the xenograft recipient animals received injection of IL-17 neutralizing antibodies before xenotransplantation. Sham control rats did not receive bone transplants. In the xenotransplant group, significant mononuclear cell infiltration and erosion/resorption of graft bone were observed. Administration of IL-17 neutralizing antibodies decreased mononuclear cell infiltration and inhibited bone resorption. The levels of IL-17+, IL-23+, and RANKL+ cells were elevated in xenotransplanted group from compared to the sham control. IL-17+ and RANKL+ cells infiltration was decreased upon administration of IL-17 neutralizing antibodies. No significant difference in the level of IL-23 in xenotransplanted groups with and without IL-17 antibodies was observed. Our results indicate that RANKL, IL-17, and IL-23 participate in the immune rejection of bone xenotransplantion. The IL-17/RANKL pathway may play a very important role in the bone resorption during rejection of fresh bone xenotransplants.

P.1.g.040 Effects of CB2 receptor inverse agonists on JNK activation and pro-apoptotic Bax in mouse brain

Changes in bone mineral density (BMD) are associated with clinical neuropathies. Following nerve injury in the rat, there is a loss of BMD, which may be related to nerve injury or reduced mechanical loading. The purpose of this study was to investigate if altered mechanical loading is solely responsible for the observed loss of BMD in neuropathic pain models. In addition, we sought to study the action of chronic bisphosphonate treatment on both neuropathy-induced osteopenia and pain. We therefore had two hypotheses: firstly, that nerve injuries can have variable effects on hind limb bone loss in rats which are not attributable to differences in the extent of hind limb disuse and, secondly, that bisphosphonate treatment can reverse bone loss in a rat mononeuropathy model, and this is not attributable to bisphosphonate effects on nociception or hind paw unweighting.Male Sprague–Dawley rats were subject to chronic constriction injury (CCI), partial sciatic nerve ligation (PSN) or L5 + L6 spinal nerve ligation (SNL). Loss of BMD, defined as a numerically lower BMD as compared to control animals, was extreme following CCI (maximum ipsilateral/contralateral difference of 0.023 ± 0.011); BMD loss following either PSN or SNL in the rat was subtle (0.010 ± 0.002 and 0.013 ± 0.012 g/cm2, respectively), significant only at early time points and had resolved by 7 weeks post-surgery. Chronic bisphosphonate treatment significantly inhibited CCI-induced osteopenia in the rat without inhibiting the reduction in weight-bearing tactile allodynia or mechanical hyperalgesia.Loss of BMD is observed in rats in a variety of neuropathic pain models. Lack of correlation between neuropathy-induced bone loss and weight bearing demonstrates that the bone loss is not simply a function of reduced mechanical loading and suggests that altered bone–nerve signaling is involved. Furthermore, chronic bisphosphonate treatment inhibits neuropathy-induced osteopenia without affecting behavioral measurements of neuropathic pain. This indicates that osteopenia is not directly related to neuropathic pain behaviors.

Acute hematopoietic stress in mice is followed by enhanced osteoclast maturation in the bone marrow microenvironment

Osteoclasts are components of hematopoietic stem cell (HSC) niches, but their role as contributors to the HSC homeostasis and release are still controversial. We aimed to investigate whether an acute blood loss of 10% of total blood content, along with the consequent intense hematopoiesis, would affect osteoclast differentiation and activity. Isolated peripheral blood, spleen, and bone marrow (BM) cells from bones of hind limbs were investigated for the presence of specific subpopulations of osteoclast precursors: B220(-)CD3(-)NK1.1(-)CD11b(-/low)CD115(+)CD117(+) cells in BM, and B220(-)CD3(-)NK1.1(-)Gr-1(-)CD11b(+)CD115(+) cells in peripheral blood and spleen as well as the receptor activator of nuclear factor κ-B(+) cycle-arrested quiescent osteoclast precursors. Expression of osteoclastogenesis-related genes CD115, receptor activator of nuclear factor κ-B, and cathepsin K, the potential of BM cells to form osteoclast-like cells in vitro, and osteoclast activity in vivo were also evaluated. We observed an increase in spleen cellularity and myelopoiesis during week 1 following blood loss, without any significant effects on BM cellularity or BM myeloid precursors, including cells with high osteoclastogenic potential. However, at 1 week postbleeding, hematopoiesis significantly promoted the expression of cathepsin K, interleukin-34, and bone morphogenetic protein-6. Quiescent osteoclast precursors increased significantly in spleen 2 days following bleeding, whereas osteoclast activity remained unchanged up to 2 weeks postbleeding. Osteoclast-dependent B-cell differentiation was affected at the pre-B stage of maturation in BM, whereas the Lin(-)Sca-1(+)c-kit(+) population expanded in BM and spleen after 2 days postbleeding. Our data demonstrate that an acute blood loss promotes differentiation and maturation of osteoclasts at 1 week but does not enhance osteoresorption at 2 weeks postbleeding. Our data also identify osteoclast differentiation as a consequent and important event in establishing HSC homeostasis following hematopoietic stress.

Anatomical and biomechanical traits of broiler chickens across ontogeny. Part II. Body segment inertial properties and muscle architecture of the pelvic limb.

In broiler chickens, genetic success for desired production traits is often shadowed by welfare concerns related to musculoskeletal health. Whilst these concerns are clear, a viable solution is still elusive. Part of the solution lies in knowing how anatomical changes in afflicted body systems that occur across ontogeny influence standing and moving. Here, to demonstrate these changes we quantify the segment inertial properties of the whole body, trunk (legs removed) and the right pelvic limb segments of five broilers at three different age groups across development. We also consider how muscle architecture (mass, fascicle length and other properties related to mechanics) changes for selected muscles of the pelvic limb. All broilers used had no observed lameness, but we document the limb pathologies identified post mortem, since these two factors do not always correlate, as shown here. The most common leg disorders, including bacterial chondronecrosis with osteomyelitis and rotational and angular deformities of the lower limb, were observed in chickens at all developmental stages. Whole limb morphology is not uniform relative to body size, with broilers obtaining large thighs and feet between four and six weeks of age. This implies that the energetic cost of swinging the limbs is markedly increased across this growth period, perhaps contributing to reduced activity levels. Hindlimb bone length does not change during this period, which may be advantageous for increased stability despite the increased energetic costs. Increased pectoral muscle growth appears to move the centre of mass cranio-dorsally in the last two weeks of growth. This has direct consequences for locomotion (potentially greater limb muscle stresses during standing and moving). Our study is the first to measure these changes in the musculoskeletal system across growth in chickens, and reveals how artificially selected changes of the morphology of the pectoral apparatus may cause deficits in locomotion.

Testosterone Dose Dependently Prevents Bone and Muscle Loss in Rodents after Spinal Cord Injury

Androgen administration protects against musculoskeletal deficits in models of sex-steroid deficiency and injury/disuse. It remains unknown, however, whether testosterone prevents bone loss accompanying spinal cord injury (SCI), a condition that results in a near universal occurrence of osteoporosis. Our primary purpose was to determine whether testosterone-enanthate (TE) attenuates hindlimb bone loss in a rodent moderate/severe contusion SCI model. Forty (n=10/group), 14 week old male Sprague-Dawley rats were randomized to receive: (1) Sham surgery (T9 laminectomy), (2) moderate/severe (250 kdyne) SCI, (3) SCI+Low-dose TE (2.0 mg/week), or (4) SCI+High-dose TE (7.0 mg/week). Twenty-one days post-injury, SCI animals exhibited a 77-85% reduction in hindlimb cancellous bone volume at the distal femur (measured via μCT) and proximal tibia (measured via histomorphometry), characterized by a >70% reduction in trabecular number, 13-27% reduction in trabecular thickness, and increased trabecular separation. A 57% reduction in cancellous volumetric bone mineral density (vBMD) at the distal femur and a 20% reduction in vBMD at the femoral neck were also observed. TE dose dependently prevented hindlimb bone loss after SCI, with high-dose TE fully preserving cancellous bone structural characteristics and vBMD at all skeletal sites examined. Animals receiving SCI also exhibited a 35% reduction in hindlimb weight bearing (triceps surae) muscle mass and a 22% reduction in sublesional non-weight bearing (levator ani/bulbocavernosus [LABC]) muscle mass, and reduced prostate mass. Both TE doses fully preserved LABC mass, while only high-dose TE ameliorated hindlimb muscle losses. TE also dose dependently increased prostate mass. Our findings provide the first evidence indicating that high-dose TE fully prevents hindlimb cancellous bone loss and concomitantly ameliorates muscle loss after SCI, while low-dose TE produces much less profound musculoskeletal benefit. Testosterone-induced prostate enlargement, however, represents a potential barrier to the clinical implementation of high-dose TE as a means of preserving musculoskeletal tissue after SCI.

Naming an Innominate: Pelvis and Hindlimbs of Miocene Whales Give an Insight into Evolution and Homology of Cetacean Pelvic Girdle

Cetaceans have highly transformed pelvic and hindlimb bones as a secondary adaptation to an aquatic lifestyle. Paleontological records of these bones are very scarce, which hampers interpretations of their homology and evolution. Newly found innominates, femora and tibia of Miocene baleen whales of family Cetotheriidae have primitive structure, which makes it possible to compare them with archaeocetes. As a result, a traditional view of a cetacean innominate as containing vestiges of all three pelvic bones and acetabulum is corroborated by new data and interpretations. A part of ischium (possibly, the superior ramus) is reduced in modern whales, but its vestige can sometimes be observed. A developmental mechanism underlying this pattern can hypothetically involve alterations in Pbx1 and Pbx2, Prrx1 and Prrx2, Pit1 or BMP7 expression: the observed anatomy is similar to reported cases of BMP7 mutations, which are combined with previously reported alterations in Shh regulation. Thus, pelvic and hindlimb reduction in modern cetaceans can in some aspects be compared to ‘Mermaid Syndrome’.

Mobilization with granulocyte colony-stimulating factor blocks medullar erythropoiesis by depleting F4/80+VCAM1+CD169+ER-HR3+Ly6G+ erythroid island macrophages in the mouse

Similarly to other tissues, the bone marrow contains subsets of resident tissue macrophages, which are essential to maintain bone formation, functional hematopoietic stem cell (HSC) niches, and erythropoiesis. Pharmacologic doses of granulocyte colony-stimulating factor (G-CSF) mobilize HSC in part by interfering with the HSC niche-supportive function of BM resident macrophages. Because bone marrow macrophages are key to both maintenance of HSC within their niche and erythropoiesis, we investigated the effect of mobilizing doses of G-CSF on erythropoiesis in mice. We now report that G-CSF blocks medullar erythropoiesis by depleting the erythroid island macrophages we identified as co-expressing F4/80, vascular cell adhesion molecule-1, CD169, Ly-6G, and the ER-HR3 erythroid island macrophage antigen. Both broad macrophage depletion, achieved by injecting clodronate-loaded liposomes, and selective depletion of CD169(+) macrophages, also concomitantly depleted F4/80(+)VCAM-1(+)CD169(+)ER-HR3(+)Ly-6G(+) erythroid island macrophages and blocked erythropoiesis. This more precise phenotypic definition of erythroid island macrophages will enable studies on their biology and function in normal settings and on diseases associated with anemia. Finally, this study further illustrates that macrophages are a potent relay of innate immunity and inflammation on bone, hematopoietic, and erythropoietic maintenance. Agents that affect these macrophages, such as G-CSF, are likely to affect these three processes concomitantly.

Toxicological effects of cadmium during pregnancy in Wistar albino rats

Cadmium is a heavy metal and widespread environmental toxicant. This study investigated the effects of prenatal Cd exposure on fetal growth and limb development in rats. Pregnant rats were given 0, 4 or 8 mg/kg/day (equivalent to ≈ 0, 30 or 60 ppm) of cadmium as CdSO4 in their drinking water from conception to gestation day 20. Cd significantly (p<0.001) and dose-dependently inhibited maternal weight gain and caused abortion of pregnancy. In addition, Cd significantly (p<0.001) decreased fetal body weight, forelimb and hindlimb bone lengths, compared to controls. These effects were sex-dependent, greater in the female offspring. Furthermore, there were reductions in the weights, and alterations in the histology of maternal placenta, ovary and liver of Cd-exposed rats. The results indicate that cadmium will cause abortion of pregnancy and sex-dependent impairment of fetal growth and limb development, which may be consequent upon alterations in ovarian and placental functions.

Protective effect of Cissus quadrangularis Linn. on diabetes induced delayed fetal skeletal ossification.

Background:Delayed fetal skeletal ossification is one of the known complications of maternal diabetes.Objective:The present study was designed to evaluate the protective role of petroleum ether extract of Cissus quadrangularis (PECQ) on diabetes-induced delayed fetal skeletal ossification.Materials and Methods:Female Wistar rats were rendered diabetic with streptozotocin (STZ, 40 mg/kg, intraperitonial) before mating. After confirmation of pregnancy, the pregnant rats were divided into three groups: normal control group, diabetic control group, and diabetic + CQ group. The diabetic + CQ group pregnant rats were treated with PECQ (500 mg/kg body weight) throughout their gestation period. Immediately after delivery, pups were collected from all three groups and processed for alizarin red S–alcian blue staining in order to examine the pattern of skeletal ossification.Results:Fewer ossification centers and decreased extent of ossification of forelimb and hindlimb bones were observed in the neonatal pups of diabetic control group as compared to those in the normal control group. PECQ pretreatment significantly restored the ossification centers and improved the extent of ossification of forelimb and hindlimb bones in the neonatal pups of diabetic + CQ group as compared to those in the diabetic control group.Conclusions:The results suggested that PECQ treatment is effective against diabetes-induced delayed fetal skeletal ossification. However, further studies on the isolation and characterization of active constituents of PECQ, which can cross the placental barrier and are responsible for the bone anabolic activity are warranted.

A three-dimensional analysis of the morphological evolution and locomotor behaviour of the carnivoran hind limb.

BackgroundThe shape of the appendicular bones in mammals usually reflects adaptations towards different locomotor abilities. However, other aspects such as body size and phylogeny also play an important role in shaping bone design.We used 3D landmark-based geometric morphometrics to analyse the shape of the hind limb bones (i.e., femur, tibia, and pelvic girdle bones) of living and extinct terrestrial carnivorans (Mammalia, Carnivora) to quantitatively investigate the influence of body size, phylogeny, and locomotor behaviour in shaping the morphology of these bones. We also investigated the main patterns of morphological variation within a phylogenetic context.ResultsSize and phylogeny strongly influence the shape of the hind limb bones. In contrast, adaptations towards different modes of locomotion seem to have little influence. Principal Components Analysis and the study of phylomorphospaces suggest that the main source of variation in bone shape is a gradient of slenderness-robustness.ConclusionThe shape of the hind limb bones is strongly influenced by body size and phylogeny, but not to a similar degree by locomotor behaviour. The slender-robust “morphological bipolarity” found in bone shape variability is probably related to a trade-off between maintaining energetic efficiency and withstanding resistance to stresses. The balance involved in this trade-off impedes the evolution of high phenotypic variability. In fact, both morphological extremes (slender/robust) are adaptive in different selective contexts and lead to a convergence in shape among taxa with extremely different ecologies but with similar biomechanical demands. Strikingly, this “one-to-many mapping” pattern of evolution between morphology and ecology in hind limb bones is in complete contrast to the “many-to-one mapping” pattern found in the evolution of carnivoran skull shape. The results suggest that there are more constraints in the evolution of the shape of the appendicular skeleton than in that of skull shape because of the strong biomechanical constraints imposed by terrestrial locomotion.

Osteohistological variation in growth marks and osteocyte lacunar density in a theropod dinosaur (Coelurosauria: ornithomimidae)

Osteohistological examinations of fossil vertebrates have utilized a number of proxies, such as counts and spacing of lines of arrested growth (LAGs) and osteocyte lacunar densities (OLD), in order to make inferences related to skeletochronology and mass-specific growth rates. However, many of these studies rely on samplings of isolated bones from single individuals. These analyses do not take individual variation into account, and as a result may lead to misleading inferences of the physiology of extinct organisms. This study uses a multi-element, multi-individual sampling of ornithomimid dinosaurs to test the amount of individual variation in the aforementioned osteohistological indicators. Based on these results we also assess the conclusions of previous studies that tested paleohistological hypotheses using isolated elements. LAG number was found to be consistent within the hind limb bones of each individual, with the exception of the fibula, which preserves one additional LAG. Considerable differences in LAG spacing were found between elements of the sampled individuals, with larger variation found in elements of the foot compared with the femur, fibula, and tibia. Osteocyte lacunar density ranged between 29000 and 42000 osteocyte lacunae per mm3, and was found to vary more between hind limb bones of an individual and within bones, than between the average values of individuals. The variation between hind limb elements in LAG number and LAG spacing suggests that direct comparisons of these elements may be misleading, and that LAG spacing is not a reliable proxy for mass-specific growth rates of an individual. Sampling of multiple bones should be performed as an internal check of model-based LAG retro-calculation and growth equations. The observation that osteocyte lacunar density varies more between individual bone elements than between average individual values suggests that the choice of sampled element can greatly influence the result, and care should be taken to not bias interpretations of the physiology of fossil tetrapods.

Macroanatomy of the Bones of Pelvis and Hind Limb of an Asian Elephant (Elephas maximus)

Fue utilizado para su estudio anatomico macrocroscopico, el esqueleto de un elefante asiatico (Elephas maximus) hembra adulta, excavado recientemente y con muerte por distocia en Bangladesh. Se observaron algunas caracteristicas morfologicas unicas de los huesos de los miembros posteriores. El canal pelvico era mas ovalado y las alas del ilion eran mas amplias. La pendiente de la rabadilla era de unos 36° aproximadamente; el angulo entre el femur y la tibia era proximo a los 180°. En el femur, el trocanter mayor se encontraba en el nivel inferior de la cabeza. El trocanter menor, la fovea capitis y cresta del trocanter estuvieron ausentes. La fosa supracondilea era superficial, mientras que la fosa intercondilea era profunda. La superficie posterior de la patela poseia una cresta vertical sobresaliente. Las superficies articulares de ambos condilos tibiales eran claramente concavas. La tibia y la fibula se articulan proximal y distalmente, manteniendo un amplio espacio interoseo. En lugar de la tuberosidad tibial, habia una depresion triangular alargada en parte proximal. Se observaron seis huesos del tarso dispuestos en tres filas. El tamano relativo de los huesos del tarso distal eran III + IV > I > II. Las longitudes comparativas de los huesos metatarsianos fueron III > II > IV > V > I. Los digitos I y V fueron los mas verticales y el digito III fue el mas horizontal. La falange proximal fue la de mayor tamano.