Functional anatomy of the distal radioulnar ligament in dogs.

The objective of this study was to functionally characterize the distal radioulnar ligament connecting the distal ends of canine antebrachial bones. The ligament has been investigated histologically in five adult dogs. After decalcification and standard paraffin embedding, 5-microm-thick sections have been stained with Hematoxylin/Eosin, Resorcin/Fuchsin, Astrablue/Nuclear-fast-red, Astrablue/Orange G. The distal radioulnar ligament can be divided into two parts, a proximal, 'interosseous' and a distal 'articular'. The former as a connecting structure experiences almost exclusively tensile stress in a proximolateral direction. The latter with an additional meniscal function is loaded in a combined tensile and compressive way. These findings can be explained with the characteristic valgus conformation of the canine carpal joint.

A method of biomechanical testing the suspensory apparatus of the third phalanx in cattle: a technical note.

There are a number of differences between the claws of the front and hind limbs in cattle concerning macroscopic shape, chemical and physical properties of claw horn and epidemiological data. Front claws have superior data in almost every respect. Virtually no information is available on the mechanical stability of the suspensory apparatus of the third phalanx. It was the objective of this study to develop a method to measure the maximum strength (N/mm2) of the suspensory apparatus of the bovine distal phalanx. This apparatus includes all layers of tissue such as bone, corium, corioepidermal junction and wall horn. The feet of 13 clinically healthy beef bulls were collected from the local abattoir. Testing was performed in three locations of the wall segment (dorsal, abaxial, axial) in a material testing machine. The corium and the corioepidermal junction were set under increasing tension until failure occurred. Maximum stress was recorded. The values ranged between 2.47-3.13 N/mm2 (dorsal), 4.08-4.87 N/mm2 (abaxial) and 2.27-2.66 N/mm2 (axial). No differences could be validated statistically between front and hind claws and between lateral and medial claws respectively. Abaxial ultimate stress values were significantly higher than dorsal and axial ones. Between the two a statistical difference could not be validated. Most of the specimens (57.1%) were torn apart at the corioepidermal junction, almost a quarter of the samples (27.6%) were to a degree disrupted at the corioepidermal junction and to a certain extent in the deeper layers of the corium. A few samples showed disruption within the horn (11.5%) or at the attachment of the third phalanx (3.8%). Biomechanical features of the experimental set-up are discussed. The biological significance of these findings is that the body weight and the additional dynamic loading is predominantly taken over by the abaxial part of the claw, while the dorsal and axial aspects are less loaded.

The visible animal project: a three-dimensional, digital database for high quality three-dimensional reconstructions.

The "Visible Animal Project" (VAP) is comprised of axial anatomic cryosections and corresponding CT and MR images of a mature dog. The digital database is used for the creation of three-dimensional computer graphics of canine anatomy. The technique of cryodissection is described in detail. The combining of the corresponding CT and MR images, and cryosections as well as the data processing for the creation of three-dimensional reconstructions is presented and examples are shown. For the first time a complete high-resolution three-dimensional database of a dog is available, which can be used as the base for further high quality three-dimensional reconstructions, similar to the "Visible Human Project" (VHP).

[Functional significance of musculature of the external nose in swine (Sus scrofa f. domestica)]. / Zur funktionellen Bedeutung der Muskulatur an der äusseren Nase beim Schwein (Sus scrofa f. domestica).

The origin and attachments of the muscles of the external nose were examined in 17 pigs comprising both sexes and different age groups. The modification of the porcine nasal apex to the snout-disc leads to different functional aspects of the muscles of the external nose. Accordingly, all these muscles are attached to the snout-disc. Only the nasolabial levator and caninus muscles are also attached to the upper lip. In addition, the snout-disc includes an intrinsic muscle, the nasal muscle. With regard to morphological and functional aspects, the nostrils can be divided into two parts. The superficial part consists of muscle and connective tissue and is dilated by the cooperative contraction of all muscles of the external nose. In contrast, the second and cartilaginous part of the nostrils dilates less readily, through contraction of the rostrally located deep fibres of the levator nasolabial muscle. As an adaptation for rooting, a special supportive system for muscles of the external nose has developed in pigs, including osseous (eminentia canina) and muscular (muscular slip of the m. levator labii superioris attached to the nasal bone, species-specific development of the m. levator nasolabialis) structures. The observed cartilaginous connection between the ventral lateral nasal and the vomeronasal cartilages suggests another transport mechanism for odours into the vomeronasal organ. Due to this connection, movement of the snout-disc and the cartilages of the external nose could imply passive movement of the vomeronasal cartilage and therefore of the vomeronasal organ.

[Radiologic description of the growth plates of the atlas and axis in foals]. / Röntgenologische Darstellung der Wachstumsfugen an Atlas und Axis beim Fohlen.

Fractures of the first two cervical vertebrae, atlas and axis, may occur in foals for different reasons, e.g. in cases of a fall, going head over heels or when being hit by a hoof. The tentative clinical diagnosis can be confirmed by x-raying the standing animal, with aid of computed tomography in the anaesthetized foal respectively. The growth plates however, and their time of closure have to be considered when interpreting radiographs. In the atlas there are two ventrolateral plates and one dorsomedian cartilagineous plate. Only the dorsal plate, however, can be found in the dorsoventral projection up to an age of about 12 months. The ventrolateral growth plates which have closed at about six months of age cannot be seen in either ther dorsoventral or laterolateral projection. In transversely oriented CT-scans all of the three centres of ossification can easily be made visible in the atlas. In the axis the cartilagineous gaps between the dens axis and the cranial epiphysis as well as the cranial and caudal epiphyseal growth plate can be shown in normal x-radiographs in both planes of projection. Besides this there are growth plates between the corpus vertebrae and the arcus vertebrae in the axis which cannot be seen in either radiographic projection. They become clearly visible in transversal CT-scans and are ossified at the age of three to four months. At the end of the first year the growth plates between the dens axis and the cranial epiphysis have closed. The cranial and caudal epiphyseal plate are gone at an age of about four to five years.

Investigations on the postnatal development of the macroscopic proportions and the topographic anatomy of the feline spinal cord.

The aim of this work was to investigate the postnatal development of the feline spinal cord. Our study showed that the main period of growth leading to the cervical and lumbar enlargements begins after birth and is completed at the age of 5-6 months. Comparing the relationship between the length of the spinal cord and the vertebral column, we found that in contrast to the adult cat, in the newborn cat, length, area and volume of segments show similar values along the spinal cord. This also applied to the length of the vertebrae. Due to a heterogeneous growth, not all segments of the spinal cord end up situated cranial to their corresponding vertebrae. As a consequence, the end of the conus medullaris is still located within the sacral canal in animals older than 2 months. These findings strongly propose that injection into the vertebral canal of the cat have to be performed caudal to the sacral vertebrae.

[Breed and age dependent structure of the eye chamber angle in cats]. / Zur rasse- und altersabhängigen Struktur des Augenkammerwinkels bei der Katze.

102 ophthalmoscopically healthy cats of both sexes, variable age and different breeds were examined gonioscopically. The examination included 70 European Domestic Shorthaired Cats, 24 Persian Cats, four Chartreuse Cats and three Siamese Cats. A distinct difference in number and distribution of fibers of the pectinate ligament was seen between different breeds. In Persian and Siamese Cats the pectinate ligament contains only a third of the fibers which are found in European Domestic Shorthaired Cats. However the fibers are thicker and less sprouted. In addition it was possible to prove an age-related development of the pectinate ligament. While the final number of fibers was seen to be already present in young cats the diameter of fibers increased with age. These findings were confirmed histologically (by stereo dissecting microscopy) light microscopy and scanning electron microscopy). Furthermore the two-layer-structure of the pectinate ligament in the cat was described for the first time.

Investigation of living cells in the nanometer regime with the scanning force microscope.

Membrane structures of different types of cells are imaged in the nanometer regime by scanning force microscopy (SFM). The images are compared to those obtained with a scanning electron microscope (SEM). The SFM imaging can be done on the outer cell membrane under conditions that keep the cells alive in aqueous solutions. This opens up the possibility of observing the kinematics of the structures that determine the interaction of a cell with its environment. Therefore, STM observations, together with information obtained with the electron microscope, open up new ways of studying the development of biological structures. With the currently possible resolution, the SFM gives access to processes such as antibody binding or endo- and exocytosis, including processes correlated to the infection of cells by viruses.

[Light and electron microscopic studies of Eperythrozoon suis]. / Licht- und elektronenmikroskopische Untersuchungen an Eperythrozoon suis.

A light and electron microscopic study was carried out on pigs experimentally infected with Eperythrozoon (E.) suis during the acute and chronic phase of infection. During the acute phase Eperythrozoon organisms can be recognised by light microscopy as bright to dark orange points or circles. In contrast, in the chronically infected pigs E. suis appear as bright yellow or green small dots on the edge of the erythrocytes or in the plasma. By scanning electron microscopy, immature, juvenile and mature forms of E. suis could be seen on the same erythrocyte during the acute phase. In chronically infected pigs ring-shaped, rounded resting-stage forms, measuring about 1 micron in diameter, can be observed.

[Preparatory feeding of the dry stage cow in regard to nutritional condition and the status of the rumen mucosa and rumen flora at calving]. / Vorbereitungsfütterung der trockenstehenden Kuh im Hinblick auf Ernährungszustand und Status von Pansenschleimhaut und Pansenflora bei der Kalbung.

Excessive fat deposition prior to calving and a negative energy balance post partum predispose the high producing cow for an intensive postpartal lipolysis and for the health problems resulting thereof. It was postulated that a well proliferated ruminal mucosa at the beginning of lactation could improve the energy supply by stabilizing the pH of the rumen content with energy rich feed and by providing a high absorption capacity for volatile fatty acids. Results of earlier experiments dealing with this problem are reviewed. Furthermore there is described a pilot experiment with 9 dry cows, which was directed to stimulate rumen mucosa growth ante partum by a low energy ration (roughage) during the first half of the dry period and a high energy ration during the last 3 to 4 weeks prior to calving, without inducing a fat cow. The ruminal mucosa reacted to that feeding regimen as expected and desired. The body weight of 3 cows in moderate and 4 cows in medium body condition increased by 7.2% or 3% during 8 to 11 or 7 to 9 weeks respectively. One of two fat cows lost 4.9% of her body weight within 8 to 9 weeks while the condition of the second animal remained unchanged. No problems were observed at calving. A further progress is expected by feeding the dry cows in two groups with different rations according to their body condition at the end of lactation. Results of experiments as well as practical experiences show that no more than 8 to 10 days are necessary to adapt the ruminal flora to a mixed ration (roughage + concentrates).(ABSTRACT TRUNCATED AT 250 WORDS)

[Functional morphology of the kidney. A review of the histophysiology of the kidney glomerulus, the nephrons and the collecting tubule system]. / Funktionelle Morphologie der Niere. Ein Uberblick zur Histophysiologie des Nierenkörperchens, des Nephrons und des Sammelrohrsystems.

The kidney is a composite organ, the specific activities of which are attributable to the peculiar construction of the individual components of the glomerula, nephrons and collecting tubules. This comprehensive review will address the essential physiological mechanisms of urine formation, such as filtration, secretion, reabsorption and concentration, and correlate these functions to morphological structures where possible. The complex structure of the renal glomerulus as the basis for the formation of primary urine (blood-urine barrier) will be documented on the basis of electron micrographs. In addition to this, the ultrastructure of the epithelium in the various tubular segments and collecting tubules will be discussed from a histophysiological stand-point, including its significance in the excretion of waste substances and maintenance of a constant fluid environment in the body (Homeostasis).

Biological effects of shock waves: effect of shock waves on the liver and gallbladder wall of dogs--administration rate dependence.

The effect of extracoporeal shock waves on the liver and the gallbladder wall was compared in two groups of dogs exposed to 1500 shock waves generated in an electrohydraulic lithotripter with 15 kV and 80 nF. The waves were focused on the gallbladder wall. In the experimental group, a shock wave burst of 10 consecutive waves with an interval of 10 ms between the waves was administered each second; in the control group, single shocks were released each second. The day following shock wave exposure, the dogs were anaesthetized, killed and then dissected. In the liver, subcapsular and intraparenchymal focal haemorrhages occurred in the high pressure field and venous thrombi in portal veins. There was a nonsignificant trend towards an increased number of venous thrombi after burst application. The gallbladder wall was haemorrhagic and oedematous, the mucosa was ulcerated in the focal area; blood clots were found in nearly all gallbladders. No differences were detected between the groups. The free plasma haemoglobin was only increased after fast shock wave administration. Increased haemolysis and the trend towards an increased number of thrombi favour cavitation as a mechanism of shock wave damage. The similar extent of tissue damage suggests that shock wave bursts can be applied for gallstone destruction in humans if the major liver vessels are kept out of the high pressure field.

Biological effects of shock waves: cavitation by shock waves in piglet liver.

Shock waves are known to generate cavitation in vitro. In vivo, extracorporeal shock waves may cause haemorrhages in tissues. Two types of changes were detected by conventional, real-time B-scan ultrasound when shock waves were administered to 5 piglet livers in vivo: transient changes consisting of bright signals in intrahepatic branches of the portal vein and tributaries of the hepatic vein, presumed to originate from gas bubbles, and stationary changes consisting of brightening of the area along the long axis of the high pressure field, presumed to indicate an increased number of gas-filled bubbles in this area. Transient changes appeared from the start of shock wave administration; bright signals were seen in liver vessels for several hundred microseconds before they were flushed away with the blood flow. Stationary changes appeared later, increased in intensity over several hundred shock waves and persisted for minutes after cessation of shock wave administration. Both types of signals were interpreted as direct evidence that lithotripter shock waves generated cavitation in vivo. Similar signals were received in the partly degassed water of the lithotripter tub. At autopsy of the piglets, focal intralobular haemorrhages and thrombi of portal veins were detected in the shock wave path. The occurrence of cavitation and tissue damage in the same gross area suggests that cavitation might be involved in the generation of tissue damage by shock waves.

Detection and evaluation of lesions in the retina, optic nerve and ciliary muscle of old rats using a electron microscope.

Spontaneous eye alteration found in retina, ciliary muscle and optic nerve of old female Wistar rats were studied using an electron microscope. Normal ultrastructures and severity of age-dependent changes were defined in all three locations using a qualitative scoring system or morphometric measurements. Degenerative changes of various severity such as vacuolization or loss of receptor membranes in the retina, and fragmentation or swelling of myelin sheaths in the optic nerve were detected in eyes of untreated animals. Only very slight changes e.g. detachment of sarcoplasma and fragmentation or reduction of myofibrils were found in the ciliary muscle. These evaluation methods have been applied to quantify a chemically-induced exacerbation of spontaneous lesions in the retina and the optic nerve.

Accelerating and retarding effects of dexamethasone on the development of the avian lung.

Fertile eggs from Bovans hybrid were treated with dexamethasone on day 17 of incubation. This treatment resulted in a stimulation of the surfactant synthesis as recorded by the increased uptake of 14C-choline into the pulmonary phosphatidylcholine and the accumulation of lipoid vacuoles. On the other hand, dexamethasone caused a delay in pulmonary fluid absorption till day 19. This delay seems to be caused by a retarded onset of lung circulation. This conclusion has been derived from the lowered pulmonary hemoglobin content at this developmental stage. On the basis of the activities of ornithokallikrein and the angiotensin converting enzyme, ornithokinin may be involved in the retarded onset of circulation.

Biological effects of shock waves: kidney haemorrhage by shock waves in dogs--administration rate dependence.

The effect of shock waves on normal canine kidneys was examined in two groups of dogs whose right kidneys were exposed to 3000 shock waves generated with 20 kV and 40 nF in a Dornier HM II lithotripter. The groups differed only in the rate of shock wave administration which was 100 and 1 per second, respectively. Autopsy was performed 24 to 30 h later. Macroscopically and histologically, significantly more haemorrhages occurred in the kidney parenchyma if shock waves were administered at a rate of 100 waves per second. Haemorrhages were diffuse, the outer medulla was most heavily affected. The results show that kidney damage is dependent on the rate of shock wave administration. They argue against a direct shock wave effect and favor cavitation as the mechanism of shock wave damage although thermal effects cannot be excluded.

Biological effects of shock waves: kidney damage by shock waves in dogs--dose dependence.

The effect of shock waves on normal canine kidneys was examined in three groups of dogs whose right kidneys were exposed to 500, 1500, or 3000 shock waves. Autopsy was performed 24-30 h later. The kidneys were enlarged with haemorrhages in the outer and inner renal capsule and intraparenchymally. Macroscopically intraparenchymal haemorrhages were restricted to the high pressure field of the shock wave and consisted of haematomas up to 18 mm diameter (most frequently 6 mm or less) and diffuse haemorrhages. Histologically, haemorrhages were shown to originate from interlobular and arcuate veins. Venous thrombosis, tubular dilatation, and diffuse interstitial haemorrhage occurred in the same area. The number of haematomas was larger, and diffuse haemorrhages were more extended after the application of 1500 and 3000 than after 500 shock waves. No difference was seen between 1500 and 3000 shock waves.

Lung development under the influence of thiourea and L-thyroxine. Retarding and toxic effects of thiourea.

Chick embryos were treated on day 17 of incubation with 32.8 mumol thiourea or 18.9 nmol L-thyroxine. As was already known from previous studies, hatching was delayed and accelerated, respectively, under these conditions. The premature induction of hatching by L-thyroxine was accompanied by an advanced development of the pulmonary structure and of the circulation and by a premature absorption of the parabronchial liquid. Thiourea exerted an opposite effect on these parameters. In several cases the structural formation of the parabronchii was suppressed after treatment with thiourea. Furthermore, parabronchial liquid accumulated in those embryos, the hatching of which was suppressed. It is suggested that these changes represent a toxic effect of thiourea rather than a retardation of pulmonary development.