Klaus-Dieter Budras

Topography, Structure and Function of the Patella and the Patelloid in Marsupials

The patella is a sesamoid bone that is found in most mammals and is regularly located in the insertion tendon of the quadriceps femoris muscle. Up to now, only a little has been known about the topography, structure and function of the patella in marsupials. Therefore the stifles of 61 marsupials of 30 different species were studied by radiography, necropsy and light microscopy. It was found that only the family of bandicoots (Peramelidae) possessed a typical patella. The other species revealed a patelloid consisting of fibrocartilage. The structure of the patelloid revealed common characteristic features in the following families of marsupials: (1) Dasyuridae, Phalangeridae, Pseudocheriidae, and Potoroidae; (2) Burramyidae; (3) Phascolarctidae, Vombatidae, and Dendrolagus; and (4) Superfamily Macropodoidea (except Dendrolagus and Potoroidae). Our results imply that the degree of differentiation in the fibrocartilage of the patelloid was strongly correlated to the mechanical forces acting on the patelloid which are a result of the specific kind of locomotion and the way of life. Generally the bony patella does not belong to the phylogenetic programme of the marsupials – with the exception of the bandicoots which are very closely related to the subclass of placental mammals (Eutheria).

Microstructure of fermented sausage

A protein matrix is necessary for the desired texture of fermented sausages suitable for slicing. The formation of this network is predominantly induced by myosin and actin proteins. A change in the structure of native muscle proteins results from different technological processes such as chopping, salting, and fermentation. During chopping with simultaneous release of meat proteins, the salt brings about a change in the original structure of proteins by swelling and partial solution of myofibrils. The dissolved proteins are transformed into a thin fluid colloidal transition state, the so-called sol-state with unstable coagulation bonds. During sausage ripening, as a result of denaturation by lactic-acid and due to gradual loss of water (drying), the unstable bonds are replaced by condensation bonds, and thus the sol-state is converted into the gel-state. Both gel formation (condensation structure) and water evaporation (syneresis) result in the development of a matrix in fermented sausage and, consequently, in the texture of the sliceable product.

On the structure of the adrenal gland of the common seal (Phoca vitulina vitulina).

The adrenal gland is a vitally important endocrine gland that occupies a central role in the regulatory mechanisms of the body metabolism. Environmental stress factors lead to permanent strain and overload of the body resulting in structural alterations of the adrenals that in turn are followed by hormonal imbalances. This leads to an increased susceptibility to bacterial and viral diseases. The recurrence of numerous fatalities in the different seal populations of the North Sea (during the years 1988, 1989 and 2002), of the Baikal Lake and Caspian Sea (during the years 2000 and 2001) were the motive for a morphological investigation of the species‐specific structure of the adrenal gland of the common seal in order to differentiate environmental stress‐induced pathological alterations from the physiological structure of this organ. The study was based on adrenals of 112 common seals (Phoca vitulina vitulina) using light microscopic and transmission and scanning electron microscopic methods. The phocine adrenal gland displays several structural characteristics. Originating from the connective tissue organ capsule, narrow and broad septa intersperse the adrenal cortex. These septa contain blastemata as a reserve for the regeneration of hormone‐producing cortical cells. Such blastemata are also occurring in the form of an intermediate zone in between the zona glomerulosa and zona fasciculata in the phocine adrenal cortex. Another species‐specific characteristic is an inverse part of the adrenal cortex encircling the central vein of the organ. These structural features have to be considered in assessment and definition of pathological alterations of the adrenals as observed in the form of exhausted blastema cell pools in the adrenocortex of seals perished in the mentioned phocine mass mortalities.

Effects of long-term extracorporeal blood perfusion of the distal portion of isolated equine forelimbs on metabolic variables and morphology of laminar tissue.

OBJECTIVEnTo establish an ex vivo model of blood perfusion in the distal portion of isolated equine forelimbs that closely represents the in vivo situation in the laminar tissue of the hoof.nnnSAMPLE POPULATIONn18 forelimbs collected from 9 healthy adult horses following slaughter at a licensed abattoir.nnnPROCEDURESnThe distal portion of isolated equine forelimbs from 9 horses were perfused under physiologic conditions over a period of 6, 8, and 10 hours with autologous blood. To determine cell viability in perfused tissues, indicators for metabolism (lactate generation and glucose and oxygen consumption) as well as indicators for cell damage (potassium concentration and lactate dehydrogenase activity) were examined at 1-hour intervals from samples of the perfusate. Weight gain in the forelimb was used to determine the edema index. After perfusion, light and electron microscopic examinations of laminar tissue specimens were performed.nnnRESULTSnDuring hemoperfusion of the isolated forelimbs, mean +/- SD glucose consumption was 197.4 +/- 65.1 mg/h, lactate generation was 1.84 +/- 0.79 mmol/h, and oxygen consumption was 6.4 x 10(-6) +/- 8.9 x 10(-5) mL.g(-1).min(-1). Neither an efflux of potassium into the perfusate nor a relevant increase of the lactate dehydrogenase activity was detected, indicating low amounts of cellular damage in the perfused tissues. Weight gain of forelimbs was 1.02 +/- 0.95%. Histologic and ultrastructural appearance of the laminar tissue revealed no signs of tissue damage.nnnCONCLUSIONS AND CLINICAL RELEVANCEnIsolated equine limbs were perfused under physiologic conditions over a period of < or = 10 hours without structural damage to the laminar tissue.