Hydrolyzed fish collagen induced chondrogenic differentiation of equine adipose tissue-derived stromal cells.

Adipose-derived stromal cells (ADSCs) are multipotent cells which, in the presence of appropriate stimuli, can differentiate into various lineages such as the osteogenic, adipogenic and chondrogenic. In this study, we investigated the effect of transforming growth factor beta 1 (TGF-ß1) in comparison to hydrolyzed fish collagen in terms of the chondrogenic differentiation potential of ADSCs. ADSCs were isolated from subcutaneous fat of horses by liposuction. Chondrogenesis was investigated using a pellet culture system. The differentiation medium was either supplemented with TGF-ß1 (5 ng/ml) or fish collagen (0.5 mg/ml) for a 3 week period. After the 3 weeks in vitro differentiation, RT-PCR and histological staining for proteoglycan synthesis and type II collagen were performed to evaluate the degree of chondrogenic differentiation and the formation of cartilaginous extracellular matrix (ECM). The differentiation of ADSCs induced by TGF-ß1 showed a high expression of glycosaminoglycan (GAG). Histological analysis of cultures stimulated by hydrolyzed fish collagen demonstrated an even higher GAG expression than cultures stimulated under standard conditions by TGF-ß1. The expression of cartilage-specific type II collagen and Sox9 was about the same in both stimulated cultures. In this study, chondrogenesis was as effectively induced by hydrolyzed fish collagen as it was successfully induced by TGF-ß1. These findings demonstrated that hydrolyzed fish collagen alone has the potential to induce and maintain ADSCs-derived chondrogenesis. These results support the application of ADSCs in equine veterinary tissue engineering, especially for cartilage repair.

Prenatal development of murine gonads with special reference to germ cell differentiation: a morphological and immunohistochemical study.

The prenatal differentiation of male and female gonads of the mouse was investigated both morphologically and immunohistochemically. Sexual dimorphism could be detected as early as 12 days post-coitum (dpc) by the appearance of the primary elements of the tunica albuginea and positive immunoreactivity for anti-Muellerian hormone in the Sertoli cells of the male gonad. Male germ cells passed two waves of mitotic activity, a first wave between 12 and 14 dpc, which is followed by apoptosis of the old germ cell generation, and a second wave between 17 and 20 dpc. Oct-4 was expressed as a juxtanuclear ring in the cytoplasm of germ cells up to 17 dpc. Subsequently, it was down-regulated and completely disappeared in 20 dpc full-term fetuses. By contrast, M2A antigen revealed only a weak immunoreaction in some germ cells of 14 dpc gonads, but exhibited strong signals in all germ cells of 20 dpc full-term fetuses. Therefore, we postulate that, in the mouse, prenatal germ cells represent two populations: the first is immunopositive for Oct-4 and disappeared in full-term fetuses, whereas the second appeared in 14 dpc and is immunopositive for M2A antigen.

In vivo mechanisms of hydroxyapatite ceramic degradation by osteoclasts: fine structural microscopy.

In the present study the in vivo mechanism of calcium-phosphate (CaP) ceramic degradation has been investigated by means of transmission electron microscopy. The results revealed osteoclast-mediated degradation of hydroxyapatite ceramic implanted into sheep bone by simultaneous resorption and phagocytosis. After 6 weeks of implantation, osteoclasts were localized immediately beneath the ceramic surface. They had formed resorption lacunae and exhibited typical ultrastructural features, such as the ruffled border, the clear zone, and the dorsal microvilli. Their resorption capacity also had become evident by alterations of the electron density and the shape of the CaP crystals localized within the acidic microenvironment of the ruffled border. Moreover, the osteoclasts simultaneously were capable of phagocytosing the resorbed CaP crystals. The formation of endophagosomes was performed (1) by the uptake of particles into large intracellular vacuoles, which were generated by deep invagination of the membranes of the osteoclastic ruffled border, and (2) by the encircling of particles due to the development of pseudopodia-like plasmaprotrusions of the ruffled border. The formation of endophagosomes was followed by the in situ fragmentation of the inclusion material, which subsequently was released into the extracellular space and phagocytosed by macrophages.

Polyvinylpyrrolidone Adsorption on Na-Montmorillonite. Effect of the Polymer Interfacial Conformation on the Colloidal Behavior and Binding of Chemicals.

Adsorption behavior of polyvinylpyrrolidone (PVP) on sodium montmorillonite, a swelling clay mineral, was investigated in diluted solutions at an ionic strength of 0.01 M, representative of environmental soil solution conditions. Physicochemical methods such as microcalorimetry, light scattering absorbance, photon correlation spectroscopy, microelectrophoresis, X-ray diffraction, and sedimentation volume measurements were used to characterize the colloidal behavior of montmorillonite particles with various PVP loadings. The extent and properties of the adsorbed PVP train, loop, and end fractions in the particle-stabilizing process have been specified. The interaction study of chemicals such as anionic surfactant sodium dodecyl sulfate and nonionized 4-monochlorophenol as well as their mixture also underlines the importance of the PVP interfacial conformations for the adsorbent capacity of this organoclay. Copyright 2000 Academic Press.

Ultrastructure of rat Purkinje neurons after chronic ethanol consumption and prolonged abstinence.

In the present study of nutrition control of Wistar white rats, the ultrastructure of cerebellar Purkinje cells was studied after chronic ethanol exposure and a subsequent period of prolonged abstinence: a qualitative investigation of the perikarya of Purkinje cells was performed in age-matched controls (group A) and rats alcohol-fed for 5 months and withdrawn from this diet for 3 months (group B). The results showed massive accumulation of small dense bodies as well as obvious deposition of lipofuscin in the Purkinje cells of group B. Furthermore, ring-shaped Golgi apparatus units, lamellar bodies and degenerative foci dispersed throughout the cytoplasm of the alcohol-treated animals referred to degeneration processes and neuronal cell death, the morphological characteristics and the aetiology of which are discussed.

[Development, cytoarchitecture and ultrastructure of the mesencephalic trigeminal nucleus in domestic ruminants]. / Entwicklung, Zytoarchitektonik und Feinstruktur des mesencephalen Trigeminuskerns bei Hauswiederkäuern.

The ontogenetic development and cell differentiation of the mesencephalic trigeminal nucleus (Ntm) is lightmicroscopically examined in 58 bovine embryos and fetuses ranging from 2.4 to 80 cm Crown-Rump-Length (CRL). The cytoarchitecture and fine structure in adult cattle, sheep, and goats are investigated with the aid of light- and electronmicroscopy. At 2.4 cm CRL, the proneurons of the Ntm are detectable for the first time within the ventricular zone of the alar plate, possessing one drop-like cytoplasmic protrusion, whereas at 5 cm CRL, two cell types with differing sizes appear. Up to a CRL of 11.5 cm, the nucleus shows advanced maturation processes and has reached his final position at the border of the mesencephalic central grey. From 26 cm CRL onward, three cell types, and at 34 cm CRL four cell types, are discernible based on their nissl-granule arrangement. The cytomorphological differentiation and the maturation of the cells proceeds until 56 cm CRL, at which point the topographical and cytological characteristics of the Ntm are comparable with those of adult animals. In adult cattle, sheep and goats the Ntm consists of large (40-60 microns) and scarce medium-sized (30-40 microns) neurons with round and oval shapes. Scarcer small (20-25 microns) round and medium-sized multipolar neurons occur. The Nissl bodies are scattered throughout the pericaryon of the large neurons in a dust-like pattern and in the medium-sized neurons in a grained form. Within the cytoplasmic streets, which are situated between the membranes of the rough ER, numerous neurofilaments and mitochondria are detectable. Large Golgi complexes are placed in a perinuclear position. The neurons are also characterized by some somatic spines, and by a moderate distribution of axosomatic synapses, in which axon-endings with flattened synaptic vesicles predominate.

[Development and cell differentiation of the motor nucleus of the facial nerve of cattle]. / Entwicklung und Zelldifferenzierung des Nucleus motorius nervi facialis beim Rind.

The early development, cell-migration and cell-differentiation of the nucleus motorius nervi facialis were studied in 32 bovine embryos with a CRL of 1 to 53 cm by light microscopical techniques. The ventro-medial cell column, a transitory embryonic formation, can be regarded as the origin of the nucleus. From there migrating cells can be demonstrated up to a CRL of 2.7 cm. With 3.8 cm CRL the cells are confined to their definitive location. From 5 cm CRL onwards a subdivision into 4 subnuclei can be seen. By succeeding maturation processes the nucleus of fetuses with 53 CRL acquires the topographical and cellular appearance of mature animals. With the electron microscope the cell-differentiation of the early stages (2.5 and 3.6 cm CRL) was demonstrated. Additionally the ventro-medial cell column was studied. The vertical columnar organisation of the neurons of the nucleus facialis shows besides longitudinal orientated guiding structures the migration process which is taken place at a CRL of 2.5 cm. Synaptogenic cell contact are seen from 3.6 cm SSL. At this stage the migration of cells has come to an end.

[Micromorphologic studies of the odontoblasts of sheep in different development and maturation stages]. / Mikromorphologische Untersuchungen an den Odontoblasten des Schafs in verschiedenen Entwicklungs- bzw. Reifestadien.

The fine tissue structure of ovine odontoblasts was studied in various developmental and maturational stages. Odontoblasts differentiate from the peripherally-located mesenchymal cells of the dental papilla. On the basis of cytological parameters, it was possible to divide the odontoblasts into the following groups: pre-odontoblasts, juvenile (light) odontoblasts and mature (dark) odontoblasts. The three maturational stages of odontoblasts exhibit substantial differences with respect to their form and to the number and arrangement of their cytoplasmatic organelles. Structural differences in the three cell types appear to be closely correlated to the level of cellular activity.

[The scaphoid-trapezium-trapezoid arthrosis. A clinical study 1982-1985]. / Die Skaphoid-Trapezium-Trapezoid-Arthrose (STT). Eine klinische Studie 1982-1985.

The present study deals with patients in whom the diagnostic procedures applied in rhizoid arthrosis were considered to reveal scaphoid-trapezium-trapezoid (STT) arthrosis. Between 1982 and 1985, 21 of 396 rhizoid arthrosis patients developed symptoms of STT arthosis. Examination of the case histories showed that in 20 STT patients the pathogenesis included trauma. In addition, the majority of these 396 patients (71.5%) had to be retreated because of new traumata and the resultant problems. The time lapse between the first trauma considered sufficiently severe to have caused STT arthrosis and its diagnosis was up to 7.1 years. Our improved facilities for diagnosis of pathologic conditions of the wrist enabled us to distinguish four types of STT arthrosis. Persistent complex instability of the capsular ligament appears to be the major cause of post-traumatic STT arthrosis. Extended diagnostic techniques based on standardized radiograms allow the development of a design for treatment aimed at preventing posttraumatic STT of the hand as far as possible.

[Report on a two-year experience with an ultrasterile operatory (author's transl)]. / Zweijährige Erfahrungen mit 2078 orthopädischen Operationen in einem ultrasterilen Operationsraum

2,078 orthopaedic operations were carried out. No infections were observed at 640 hip-joint total endoprosthesis, 26 knee-joint endoprosthesis and 185 osteosynthesis. One primary infection happened in one case only, namely at an elbow-joint endoprosthesis. The compressed air installation, which drives the airturbines, was found to be the reason for the air not being germ-free what caused the infection. It is important that the turbines operate with germ-free air, and that the air recycling equipment is air-tight. The germ-free air of the horizontal displacement flow in an ultra-sterile operatory gives optimum ambient conditions for the operations, particularly when alloplastic interventions with big extraneous objects entail the risk of infections. After also many hours of operation, the air germination was extremely low and practically insignificant and cannot be obtained at such a low degree for conventionally air-conditioned operatories.

[The fine structure of the lymphatics in the rumen wall of the goat]. / Die Feinstruktur der Lymphgefässe in der Pansenwand der Ziege

Ruminal lymphvessels from the goat were investigated with light- and electronmicroscope after blockade of the lymphdrainage and vascular perfusion by means of yellow fix solution. The lymphvessels of the ruminal wall do not originate directly from below the epithelium but from the deeper layers of the Propria mucosae. As far as ruminal papillae are concerned, lymphatic vessels are only to be found at their base. All lymphvessels consist of a basement membrane and an endothelium. Only the ones which are situated in the Subserosa or in the musculature of the wall are provided with lymphatic valves.