Hand development and sequence of ossification in the forelimb of the European shrew Crocidura russula (Soricidae) and comparisons across therian mammals.

Hand development in the European shrew Crocidura russula is described, based on the examination of a cleared and double-stained ontogenetic series and histological sections of a c. 20-day-old embryo and a neonate. In the embryo all carpal elements are still mesenchymal condensations, and there are three more elements than in the adult stage: the 'lunatum', which fuses with the scaphoid around birth; a centrale, which either fuses with another carpal element or just disappears later in ontogeny; and the anlage of an element that later fuses with the radius. Carpal arrangement in the neonate and the adult is the same. In order to compare the relative timing of the onset of ossification in forelimb bones in C. russula with that of other therians, we built up two matrices of events based on two sets of data and used the event-pair method. In the first analysis, ossification of forelimb elements in general was examined, including that of the humerus, radius, ulna, the first carpal and metacarpal to ossify, and the phalanges of the third digit. The second analysis included each carpal, humerus, radius, ulna, the first metacarpal and the first phalanx to ossify. Some characters (= event-pairs) provide synapomorphies for some clades examined. There have been some shifts in the timing of ossification apparently not caused by ecological and/or environmental influences. In two species (Oryctolagus and Myotis), there is a tendency to start the ossification of the carpals relatively earlier than in all other species examined, the sauropsid outgroups included.

Amputation and heat induced protein synthesis in the regenerating forelimb of Notophthalmus viridescens

This thesis compares the responses of regenerating forelimb tissues of the newt Notophthalmu..f vlridescens to the stresses of hyperthermia and ID.echanical injury of amputation. In particular, both quantitative and qualitative changes in the synthesis of soluble proteins in stump tissues, including those of the heat shock protein family (HSP70-1ike) were examined. Results from SDS-PAGEfluorography indicate that the trauma of amputation mimics the heat shock response both quantitatively and temporally in its transient repression of the synthesis of most normal cellular proteins, and qualitatively. in the locaJized expression of two unique proteins (hsp30 and hsp70). Fluorography of proteins separated by twodimensional gets revealed that thelCl4:alizedt amputation induced 70kDa protein (amp70) was distinct from the more basic newt hsp/hsc70 isoforms. Although limb amputation resulted in an increase in the synthesis of HSP70 mRNA analogous to that induced by heat 3.b.OCKf amp70 did not cross-react with murine monoclonal antibodies directed against both the inducible and cognate HSP70 proteins of the human. Thus, the possible relationship of amp70 to other members of the HSP70-1ike protein family remains unclear. Western analyses indicated that the levels of the constitutive form of HSP70 (hsc70) were found to be regulated in a stage-dependent manner in the distal stump tissues of the regen,erating forelimb of the newt. The highest levels were found in the mid-late bud stage, a period during which rapidly dividing blastema cells begin to redifferentiate in a proximodistal direction. Immediately after amputation) hsc70 synthesis and accumulation was depressed below steady-state levels measured in the unamputated limb~ The results are discussed in light of a possible role for HSPs and amputatio~ induced proteins in the epimorphic regeneration of the amphibian limb.

An examination of transcriptional and translational regulation of the 70kDa heat shock proteins following amputation of the tail and forelimb in the newt Notophthalmus viridescens

Several stresses to tissues including hyperthermia, ischemia, mechanical trauma and heavy metals have been demonstrated to affect the regulation of a subset of the family of heat shock proteins of70kOa (hsp70). In several organisms following some of these traumas, the levels of hsp70 mRNA and proteins are dramatically upregulated. However, the effects of the stress on limb and tail amputation in the newt Notophthalmus viridescens, involving mechanical tissue damage, have not adequately been examined. In the present study, three techniques were utilized to quantitate the levels of hsp70 mRNA and protein in the tissues of the forelimbs and tails of newts during the early post-traumatic events following surgical resection of these:: appendages. These included quantitative Western blotting of proteins separated by both one and twodimensional SDS-polyacrylamide gel electrophoresis and quantitative Northern blot analysis of total RNA. In tissues of both the limb and tail one hour after amputation, there were no significant differences in the levels of hsp70 protein measured by one-dimensional SOSPAGE followed by Western blotting, when compared to the levels measured in the unamputated limb. A 30 minute heat shock at 35°C failed to elicit an increase in the levels of hsp70 protein in these tissues. Further analysis using the more sensitive 20 PAGE separation of stump tissue proteins revealed that at least some of the five hsp70 isoforms of the newt may be differentially regulated in limbs and tails in response to trauma. It appears also that amputation of the tail and limb tissues leads to slight 3 elevation in the levels of HSP70 mRNA when compared to those of their respective unstressed tissues.

Morphology and myofiber composition of skeletal musculature of the forelimb in young and aged wild type and myostatin null mice

Most current research into therapeutic approaches to muscle diseases involves the use of the mouse as an experimental model. Furthermore, a major strategy to alleviate myopathic symptoms through enhancing muscle growth and regeneration is to inhibit the action of myostatin (Mstn), a transforming growth factor-beta (TGF-beta) family member that inhibits muscle growth. Presently, however, no study has expanded the morphological analysis of mouse skeletal muscle beyond a few individual muscles of the distal hindlimb, through which broad conclusions have been based. Therefore, we have initially undertaken an expansive analysis of the skeletal musculature of the mouse forelimb and highlighted the species-specific differences between equivalent muscles of the rat, another prominently used experimental model. Subsequently, we examined the musculature of the forelimb in both young and old adult wild-type (mstn(+/+)) and myostatin null (mstn(-/-)) mice and assessed the potential beneficial and detrimental effects of myostatin deletion on muscle morphology and composition during the aging process. We showed that: (1) the forelimb muscles of the mouse display a more glycolytic phenotype than those of the rat; (2) in the absence of myostatin, the induced myofiber hyperplasia, hypertrophy, and glycolytic conversion all occur in a muscle-specific manner; and, importantly, (3) the loss of myostatin significantly alters the dynamics of postnatal muscle growth and impairs age-related oxidative myofiber conversion.

Goniometric measurements of the forelimb and hindlimb joints in sheep

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Kinematic analysis of forelimb and hind limb joints in clinically healthy sheep

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Gait analysis in a cat with scapular luxation and contralateral forelimb amputation

This report describes the use of a pressure-sensitive walkway to evaluate an uncommon case of a cat with dorsal luxation of the left scapula and an amputated right forelimb. The findings suggest that limb amputation induced load redistribution mostly to the contralateral forelimb despite the scapular luxation.

T-cell lymphoma in the tongue of a dog with cutaneous and striated forelimb muscle involvement

Background: Primary tongue tumors rarely affect dogs and correspond to 4% of tumors involving the oropharynx. Until now, primary tongue lymphoma had not been reported. However, lymphoma involvement in the skeletal muscle, although quite unusual, was described in the literature in four cases. Cutaneous lymphoma is another rare extranodal manifestation. The objective of this report is to describe a case of T immunophenotype lymphoma occurrence, whose manifestation is atypical, not only because it is situated in the tongue muscle but also because of the subsequent involvement of the striated musculature of the left forelimb and the skin, which showed unfavorable evolution. Case: A female seven-year-old mongrel was seen showing a regular lump in the base of the tongue, 3 cm in diameter, not ulcerated and of fi rm consistency, with halitosis as the only clinical sign of the disease. Incisional biopsy of the lump was performed and histopathology verifi ed that it was large cell lymphoma. The material was sent for immunohistochemical evaluation and was characterized as T immunophenotype lymphoma by positive CD3 and negative CD79a marking. The CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy protocol was established as treatment and after the fi rst chemotherapy session there was partial remission of the mass, measuring 2 cm in diameter. The lump, however, remained stable in the following sessions. Thirty days after the diagnosis of lymphoma, the animal began to show lameness of the left forelimb and swelling near the head of the left humerus. A muscle mass, fi rm in consistency, progressing fast, presented a signifi cant increase, just three weeks after its appearance. Two skin lesions, arcuate, erythematous and pruritic also appeared in the dorsocervical and ventral-abdominal region. Incisional biopsy of these lesions was performed and the histopathological diagnosis confi rmed muscle and cutaneous large cell lymphoma and immunophenotype compatible with T cells (positive CD3 and negative CD79a). Due to disease advance, even during chemotherapy, a rescue protocol of L-asparaginase administration followed by lomustine and prednisone was proposed. Even with the rescue protocol there was no remission of the tumors and the case was classifi ed as progressive. The animal of this report died after completing the fi rst cycle of chemotherapy protocol, with a survival of 92 days. Discussion: Despite the fact that clinical behavior of primary lymphoma in dogs’ skeletal muscle is unknown, it is believed that, as in humans, it can be associated with chronic infl ammation or neoplastic cell invasion by proximity of the tumor or metastasis, which could justify the dissemination of the lymphoma reported here from the tongue to other tissues. However, appearance of concurrent independent lymphomas cannot be ruled out. As observed in the three cases of primary muscular lymphoma, the dog of this report had low response to therapy and short survival. This report presents the fi rst case of lymphoma in tongue with subsequent skin and left forelimb skeletal muscle involvement described in the literature. The clinical outcome corroborates the aggressiveness of muscular lymphoma observed in the other reports and also suggests that both tongue and other skeletal muscle tumors should be included in the differential diagnosis of canine lymphoma.

Adenocarcinoma metastasis of the intertransversarius cervicis muscle eliciting a right forelimb lameness in a dog

This article describes identification of a metastatic adenocarcinoma to the intertransversarius cervicis muscle using magnetic resonance imaging (MRI) in a dog that presented with chronic lameness of the right forelimb. Magnetic resonance imaging revealed a right sided, ovoid signal abnormality within the intertransversarius cervicis muscle lateral to the sixth cervical (C6) vertebra. The lesion was uniform, hyperintense on T2- and isointense on T1-weighted images to muscle and exhibited uniform contrast enhancement on T1-weighted images. The MRI findings were consistent with a neoplasia. Surgical excision was performed. Histopathological diagnosis was metastatic fibrous adenocarcinoma. The dog recovered rapidly but 6 months post-operatively he was killed because of lung metastases. Necropsy was declined and the primary tumour could not be identified.

Prdm1 acts downstream of a sequential RA, Wnt and Fgf signaling cascade during zebrafish forelimb induction

Vertebrate limb induction is triggered in the lateral plate mesoderm (LPM) by a cascade of signaling events originating in the axial mesoderm. While it is known that Fgf, Wnt and retinoic acid (RA) signals are involved in this cascade, their precise regulatory hierarchy has not been determined in any species. tbx5 is the earliest gene expressed in the limb bud mesenchyme. Recently, another transcription factor, Prdm1, has been shown to be crucial for zebrafish forelimb development. Here, we show that Prdm1 is downstream of RA, Wnt2b and Tbx5 activity. We find that RA activity, but not Fgf signaling, is necessary for wnt2b expression. Fgf signaling is required for prdm1 expression in the fin bud, but is not necessary for the initiation of tbx5 expression. We propose a model in which RA signaling from the somitic mesoderm leads to activation of wnt2b expression in the intermediate mesoderm, which then signals to the LPM to trigger tbx5 expression. tbx5 is required for Fgf signaling in the limb bud leading to activation of prdm1 expression, which in turn is required for downstream activation of fgf10 expression.

Muscular anatomy of the pectoral and forelimb of caiman crocodilus crocodilus (linnaeus, 1758) (crocodylia: alligatoridae)

v. 17, n. 2, p. 285-295, abr./jun. 2016.

Os histricomorfos sul-americanos: uma análise comparativa do desenvolvimento embriológico

O objetivo do estudo foi realizar uma análise embriológica dos roedores histricomorfos (paca, cutia, preá e capivara), a fim de comparar com a de outros roedores e com a morfogênese humana um padrão embriológico. Utilizaram-se 8 espécimes de roedores sendo, 2 embriões para cada espécie coletada, ambas em inicio de gestação. Estes foram retirados dos úteros gestantes através de ovariosalpingohisterectomia parcial, seguido de fixação em solução de paraformaldeído 4%. Para as mensurações de Crow-Rump, adotou-se como referência a crista nucal numa extremidade e da última vértebra sacral na extremidade oposta. De forma geral, os embriões analisados mostraram as seguintes características morfológicas: divisão dos arcos branquiais, o não fechamento do neuróporo cranial em alguns embriões estudados, a curvatura cranial acentuada e os somitos delimitados e individualizados. O broto dos membros apresentava-se em desenvolvimento em formato de remo, além da impressão cardíaca e fígado. Na região caudal, visualizou-se a curvatura crânio-caudal, a vesícula óptica com e sem pigmentação da retina, a abertura do tubo neural na região do quarto ventrículo encefálico, a fosseta nasal e a formação das vesículas encefálicas. Concluímos que desenvolvimento embriológico dos roedores histricomorfos pode ser comparado à morfogênese de ratos, cobaios, coelhos e humanos nos diferentes estágios de desenvolvimento, tomando apenas o cuidado com as particularidades de cada espécie, além da implementação de tecnologias reprodutivas, especialmente a de embriões, a qual requer o conhecimento do desenvolvimento pré-implantação referente às fases de desenvolvimento.

Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of 3-Hole 4.5 mm locking compression plate and 3-hole 4.5 mm narrow dynamic compression plate, with two transarticular 5.5 mm cortex screws

Objectives To compare the biomechanical characteristics of 2 arthrodesis techniques for the equine proximal interphalangeal joint (PIP) using either a 3-hole 4.5 mm locking compression plate (LCP) or 3-hole 4.5 mm narrow dynamic compression plate (DCP), both with 2 transarticular 5.5 mm cortex screws. Study Design Experimental. Sample Population Cadaveric adult equine forelimbs (*n=6 pairs). Methods For each forelimb pair, 1 limb was randomly assigned to 1 of 2 treatment groups and the contralateral limb by default to the other treatment group. Construct stiffness, gap formation across the PIP joint, and rotation about the PIP joint were determined for each construct before cyclic axial loading and after each of four, 5000 cycle loading regimens. After the 20,000 cycle axial loading regimen, each construct was loaded to failure. Results There were no significant differences in construct stiffness, gap formation, or sagittal plane rotation between the LCP and DCP treatment groups at any of the measured time points. Conclusion Biomechanically, fixation of the equine PIP joint with a 3-hole 4.5 mm LCP is equivalent to fixation with a 3-hole 4.5 mm narrow DCP under the test conditions used.

Somatotopic organization and cortical projections of the ventrobasal complex of the flying fox: an "inverted" wing representation in the thalamus

The present study investigates the somatotopic representation in the somatosensory thalamus of a megachiropteran bat. Using standard microelectrode mapping techniques, representational maps were generated for the ventrobasal (Vb) and posterior (Po) thalamic complexes of the Grey-headed flying fox. Anatomical tracing from neocortical injections provided additional data confirming the somatotopy found physiologically. A full representation of the body surface innervated by the trigeminal and spinal nerves was found. However, in contrast with other mammals, the representations of the forelimb and adjacent thoracic trunk within the thalamus were inverted. This means that the distal portions of the wing membrane and the tips of the digits were represented dorsally in Vb, and the thoracic trunk was represented ventrally In Po the digit tips were represented in the ventral most portion and the thoracic trunk in the dorsal portion of the nucleus. These results are discussed in relation to similarities of megachiropteran somatosensory thalamic nuclei to those of other mammalian species and in relation to the formation of thalamic somatotopic maps and fiber sorting.

Alterations of neocortical pyramidal cell phenotype in the Ts65Dn mouse model of Down syndrome: Effects of environmental enrichment

Mental retardation in individuals with Down syndrome (DS) is thought to result from anomalous development and function of the brain; however, the underlying neuropathological processes have yet to be determined. Early implementation of special care programs result in limited, and temporary, cognitive improvements in DS individuals. In the present study, we investigated the possible neural correlates of these limited improvements. More specifically, we studied cortical pyramidal cells in the frontal cortex of Ts65Dn mice, a partial trisomy of murine chromosome 16 (MMU16) model characterized by cognitive deficits, hyperactivity, behavioral disruption and reduced attention levels similar to those observed in DS, and their control littermates. Animals were raised either in a standard or in an enriched environment. Environmental enrichment had a marked effect on pyramidal cell structure in control animals. Pyramidal cells in environmentally enriched control animals were significantly more branched and more spinous than non-enriched controls. However, environmental enrichment had little effect on pyramidal cell structure in Ts65Dn mice. As each dendritic spine receives at least one excitatory input, differences in the number of spines found in the dendritic arbors of pyramidal cells in the two groups reflect differences in the number of excitatory inputs they receive and, consequently, complexity in cortical circuitry. The present results suggest that behavioral deficits demonstrated in the Ts65Dn model could be attributed to abnormal circuit development.