Microvasculature of the bovine claw demonstrated by improved micro-corrosion-casting technique

Hirschberg, R. M.; Mülling, Christoph; Bragulla, Hermann

doi:10.1002/(sici)1097-0029(19990501)45:3<184::aid-jemt6>3.0.co;2-o

Cited by 13 publications

(12 citation statements)

References 10 publications

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“…Third, invasive polymeric preservatives are known to require extensive, controlled perfusion, as osmosis and/or capillary action is not sufficient for adequate penetration. Efforts to replicate vasculature with polymers do not allow for free-floating microstructures inside vessels, produce extensive filling defects and do not form lumen (Hirschberg et al 1999). Finally, when polymerized PVA and recovered dinosaur vessels were visualized under SEM, PVA responded to the electron beam with immediate swelling and cracking of material, resulting in significant alteration (personal observation, not shown).…”

Section: (C) Moa Trabecular Bone (Mor Oft255) (D ) Mammoth (Mor 917mentioning

confidence: 99%

Soft tissue and cellular preservation in vertebrate skeletal elements from the Cretaceous to the present

2007

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Soft tissues and cell-like microstructures derived from skeletal elements of a well-preserved Tyrannosaurus rex (MOR 1125) were represented by four components in fragments of demineralized cortical and/or medullary bone: flexible and fibrous bone matrix; transparent, hollow and pliable blood vessels; intravascular material, including in some cases, structures morphologically reminiscent of vertebrate red blood cells; and osteocytes with intracellular contents and flexible filipodia. The present study attempts to trace the occurrence of these four components in bone from specimens spanning multiple geological time periods and varied depositional environments. At least three of the four components persist in some skeletal elements of specimens dating to the Campanian. Fibrous bone matrix is more altered over time in morphology and less likely to persist than vessels and/or osteocytes. Vessels vary greatly in preservation, even within the same specimen, with some regions retaining pliability and other regions almost crystalline. Osteocytes also vary, with some retaining long filipodia and transparency, while others present with short and stubby filipodia and deeply pigmented nuclei, or are pigmented throughout with no nucleus visible. Alternative hypotheses are considered to explain the origin/source of observed materials. Finally, a twopart mechanism, involving first cross-linking of molecular components and subsequent mineralization, is proposed to explain the surprising presence of still-soft elements in fossil bone. These results suggest that present models of fossilization processes may be incomplete and that soft tissue elements may be more commonly preserved, even in older specimens, than previously thought. Additionally, in many cases, osteocytes with defined nuclei are preserved, and may represent an important source for informative molecular data.

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Section: (C) Moa Trabecular Bone (Mor Oft255) (D ) Mammoth (Mor 917mentioning

confidence: 99%

Soft tissue and cellular preservation in vertebrate skeletal elements from the Cretaceous to the present

2007

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“…Much already is known about equine laminitis and over the years this knowledge has been projected onto cattle as well. Although the suspensor apparatus has the same function, morphology and anatomy are different to a certain extent (LISCHER et al, 2002;HIRSCHBERG & PLENDL, 2005). This difference mainly concerns the laminae and the digital cushion or supporting tissue of the claw.…”

Section: Results and Discussion Lateral Versus Medial Claw Pressurementioning

confidence: 99%

“…In cows the cushion is soft, containing a large amount of fat, consisting of mono-unsaturated fatty acids, providing a soft cushion and good shock absorbing features. Both these weight bearing structures will be affected in case of overloading, causing alterations in the dermal-epidermal junction and the fatty cushions (HIRSCHBERG et al, 1999). pressure and force where located were assessed and it was found that while the cow was eating, the highest mean pressure shifted slightly towards the sole.…”

Section: Results and Discussion Lateral Versus Medial Claw Pressurementioning

confidence: 99%

Comparação De Modelos De Crescimento Para O Meloeiro Irrigado

Paz

Lacerda

Maia

2009

Revista Brasileira De Engenharia De Biossistemas

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Claw horn lesions are believed to develop from increased pedal bone mobility induced by changes in the corium tissue. During the planning of barns herd owners are faced with choices of materials and dimensions, as well as feed bunk heights. Among the causes that may lead to front claw injuries there is the height of the feed bunk, as the cow changes its postural behavior in order to reach the food. This research aimed to study the dairy cows' front claws force exerted during eating for determining the lesion risk factor of the feed bunk height. Eight dairy cows were placed in front of the feed bunk, their front claws stepped on the pressure assessment system, and the forces exerted on front claws due to the eating postural change were recorded. The mean pressure, the maximum pressure, the floor contact area, and the mean force per region were calculated. While the cow was eating, the highest mean pressure shifted slightly towards the sole. In the lateral claw the maximum pressure was also shifted slightly towards the toe. No difference was found in the variables analyzed for both lateral and medial sides, as well for the force distribution in the left and right claws. Results of this experiment were not conclusive, not allowing explaining either laminitis or the corkscrew deformity as a result of the force exerted in the claws by means of height of the feed bunk being a risk factor. Keywords: lameness, animal welfare, feed bunk design. RESUMO Acredita-se que lesões de casco se desenvolvem pelo acréscimo da mobilidade podal induzida pelas alterações no casco, durante a produção. Durante o planejamento das instalações, donos de rebanhos encontram distintas escolhas de materiais e dimensões, assim como altura do comedouro. Dentre as causas que podem levar a lesão nos cascos dianteiros está a altura do comedouro, pois a vaca modifica seu comportamento postural para alcançar o alimento. Esta pesquisa objetivou estudar as forças exercidas nos cascos frontais durante alimentação, para determinar o fator de risco da altura do comedouro no aparecimento de lesões. Oito vacas leiteiras foram colocadas em frente do comedouro com as patas dianteiras sobre um sistema de medida de pressão e as forças exercidas pelos cascos frontais, devidas à mudança da postura enquanto comiam, foram registradas. As pressões média e máxima, a área de contato com o piso e a força média por região foram calculadas. Enquanto a vaca se alimentava, a pressão máxima se moveu ligeiramente para a sola. Na parte lateral do casco a pressão máxima também se deslocou na direção anterior (ponta do dedo). Não foi encontrada diferença nas variáveis analisadas para os lados laterais ou centrais, assim como na distribuição de forças do casco direito e esquerdo. Os resultados desse experimento não foram conclusivos, não permitindo que a presença de laminite ou a deformidade de casco "corkscrew claw", seja entendida como um resultado da força exercida pelos cascos, por causa da altura do comedouro, sendo este um fator de risco.Palavras-Chaves: laminite, ...

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“…The limbs were selected according to suitability for corrosion casting and inspected for healthiness of claws prior to casting. Casting procedure with Tensolcement (ICI Chemicals and Polymers, Darwen, Lancastershire, UK) diluted with ethylacetate (Fluka Chemie, Buchs, Switzerland), and Mercox (Japan Vilene Hospital, Tokyo, Japan) diluted with methylmethacrylate (Fluka) was carried out according to the method described by Hirschberg et al (1999).…”

Section: Materials and Methods Scanning Electron Microscopy Of Pododementioning

confidence: 99%

“…To make matters worse, results from research on the pathogenesis of equine laminitis or structure and function of the equine hoof were often transferred uncritically to the bovine claw without taking into account the differences in stance and weight-bearing between these species. Systematic studies on the weight-bearing system of the claw (Rä ber, 2000;Westerfeld, 2003) and on the bovine pododermal angioarchitecture (Hirschberg et al, 1999(Hirschberg et al, , 2001Vermunt and Leach, 1992) have been presented only recently, and thus provided a basis for new research approaches. So-called ''neo-capillary'' formations in claw diseases have been mentioned by earlier researchers (Andersson and Bergmann, 1980;Boosman, 1990;Maclean, 1966;Nilsson, 1963), but until now were never associated with the concept of pododermal angiogenesis.…”

Section: Introductionmentioning

confidence: 99%

Pododermal angiogenesis and angioadaptation in the bovine claw

Hirschberg

Plendl

2005

Microscopy Res & Technique

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Pododermal microvascularization has been suggested to play a key role in the physiological function of the bovine claw and in the pathogenesis of claw diseases. According to our working hypothesis, angiogenesis plays a central role in the physiological and pathological function of the claw and is induced by the pro-angiogenic vascular endothelial growth factor (VEGF). As a basis for further research, the aim of the present study was to examine the mechanisms of pododermal angiogenesis in the functional adaptation of the microvasculature of the claw in histological serial sections and microcorrosion casts of healthy juvenile and adult claws as well as pathologically altered claws. Scanning electron microscopy of microcorrosion casts allowed assessment of the 3D aspect of pododermal angiogenesis and angioadaptation, and was substantiated by a concomitant examination of a 3D in vitro model of angiogenesis based on cultured bovine microvascular endothelial cells. Particularly in the juvenile, but also in the adult claw, sprouting and intussusceptive angioadaptation was demonstrated and resembled the respective stages of in vitro angiogenesis. Evidence of angiogenic processes was also detected in the pathologically altered claws displaying symptoms of subclinical laminitis and/or the digital dermatitis complex. The detected angioadaptation was visible expression of the increased metabolic demands of the claw caused by the growing body weight load. Angiogenic remodeling of the pododermal angioarchitecture was also the connectional reparative principle in pathologically altered claws. Related research perspectives for prophylaxis and therapy of claw diseases are discussed.

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Microvasculature of the bovine claw demonstrated by improved micro-corrosion-casting technique

Cited by 13 publications

References 10 publications

Soft tissue and cellular preservation in vertebrate skeletal elements from the Cretaceous to the present

Soft tissue and cellular preservation in vertebrate skeletal elements from the Cretaceous to the present

Comparação De Modelos De Crescimento Para O Meloeiro Irrigado

Pododermal angiogenesis and angioadaptation in the bovine claw

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