Skull of the grey heron (Ardea cinerea): Detailed investigation of the orbital region.

The skull of the grey heron (Ardea cinerea) was examined with an emphasis on describing the orbital region. In the young (circa sixteen to seventeen days old) heron, the frontal bone (os frontale) and nasal bone (os nasale) comprised separate paired bones, connected by sutures (sutura interfrontalis, sutura internasalis and sutura frontonasalis plana). In adult animals, the relationship between these bones was different: the left and right frontal bone and the left and right nasal bone had grown together, and the frontal bone and nasal bone had fused into a common frontonasal bone (os frontonasale). In the ectethmoid bone (os ectethmoidale), the main components comprised of the orbital and antorbital part of the ectethmoid plate (lamina ectethmoidalis orbitalis et antorbitalis), the lateral process (processus lateralis ectethmoidalis) and the tubercle (tuberculum ectethmoidalis); the left and right ectethmoid plates were fused together to form the ectethmoid sinus (sinus ectethmoidalis) between them. In the young heron, the anatomical and functional link between the frontal and lacrimal bones did not exist yet, nor did the osseous frame of the ectethmoid-lacrimal complex. Further research into the young heron skulls is needed. This article provides novel insights into the grey heron's orbital region.

Apoptosis and proliferation during seasonal testis regression in the brown hare (Lepus europaeus L.).

Testes samples of 52 brown hares (Lepus europaeus L.), sacrificed between July and January, were subjected to immuno histochemical analysis. The terminal deoxynucleotidyl transferase-mediated d'UTP nick end labelling (TUNEL) method was applied to detect apoptosis; and antibodies to proliferating cell nuclear antigen (PCNA) were used to evaluate cell proliferation in the testes. In the seminiferous epithelium, the apoptotic processes were evident from August to early November with maximal values in September. Cell death in germ cells occurs predominantly during the prophase of the first meiotic division. In July, and from mid-November onwards, only the occasional TUNEL-positive cells can be seen. The proliferation of germ cells continues during the testis regression phase. The average number of PCNA-positive cells decreases slightly from September onwards and rises again in mid-November.

Apoptosis and proliferation in the testes of the brown hare (Lepus europaeus) under the influence of photoperiod.

Brown hare is a seasonal breeding mammal and under the influence of photoperiod the spermatogenesis ceases during autumn months - most markedly in September and October. Testis samples from 34 animals, sacrificed between July and December were fixed in Bouin solution, embedded in paraffin, subjected to immunohistochemistry and analysed by light microscopy. TUNEL (terminal deoxynucleotidyl transferase-mediated d'UTP nick end labeling) method was applied to detect apoptosis, anti PCNA (proliferating cell nucleolar antigen) antibodies were used to evaluate cell proliferation and antibodies against apolipoprotein D and 3beta-HSD (3beta-hidroxysteroid dehydrogenase) to evaluate the activity of the Leydig cells. Our results show that the apoptotic processes in seminiferous epithelium are obvious in August and reach peak in September, with cell death occurring during prophase of I meiotic division. In July, and from early November onwards only occasional TUNEL positive cells can be seen. The proliferation of the germ cells continues also during phase of regression (September, October and early November). Active testosterone producing Leydig cells appear to be absent in September, whereas their activity becomes obvious in the middle of November.

Growth dynamics of lipizzan horses and their comparison to other horse breeds.

A typical body format of Slovenian Lipizzan horse was investigated. The study included 6 foals (5 colts and 1 filly) at the Lipica stud farm. They were measured from birth to twenty-seven months and again at forty-four months of age. Measurements included body length, chest circumference, withers height and body mass. All those measurements were statistically evaluated and compared to some other horse breeds to determine the similarity of the growth dynamics of those horse breeds. It was concluded that the parameters of the head and neck reached their full growth at the age of 27 months and also exceeded the values of their parents. The same results were obtained with the length and heights of the body (body length, withers height, etc.) and with the parameters of the front and hind legs. However the girth width, hip width and some other parameters had not yet reached their full growth at 27 months. We observed different growth dynamics with the body weight. The parameter continued to grow after 27 months of age. The same growth dynamics also seem to apply to other investigated horse breeds although the actual measurements were slightly different.

Position and histological structure of the testes in the brown hare (Lepus europaeus) during seasonal regression and recrudescence.

The position and histological structure of the testes of 33 brown hares (Lepus europaeus) were studied from July to December. From July to September, the testes were located in the scrotum; in October and November, in some animals, the testes were positioned more or less in the inguinal canal towards the abdominal cavity, and in December none of the investigated animals had testes located in the scrotum. Testes were weighed and a quantitative analysis of tissue components was performed: the diameter of the seminiferous tubules, the depth of the seminiferous epithelium, the thickness of the tunica albuginea, the thickness of the peritubular tissue and the relative proportion of seminiferous tubules were determined. The tunica albuginea and peritubular tissue were thickest in September, October and at the beginning of November. In the same months the testis weight was low, and the diameter of the seminiferous tubules, the depth of the seminiferous epithelium and the relative proportion of seminiferous tubules in the testis tissue were significantly lower than in other months. We did not find any correlation between testicular regression or testis weight reduction and the change in the position of the testes. During recrudescence of spermatogenesis in November and December the testes were located in the inguinal canal.

Tissue distribution of planar and non-planar chlorobiphenyls, 4,4'-DDE and hexachlorobenzene in sheep and lambs.

The bioconcentration and distribution pattern of individual PCB congeners (IUPAC Nos: -54, -80, -155 and -169) and organochlorine pesticides (HCB and 4,4'-DDE) in blood, adipose tissue, liver and brain were examined in sheep two months after administration and in their offspring continuously exposed during the two months lactation period. Analyses were performed by high resolution gas chromatography. The levels of individual organochlorines varied significantly between tissues; the tissue/blood ratio (on a fat basis) varied by two orders of magnitude for individual congeners. The bioconcentration of the toxic planar PCB-169 congener was the highest in the liver and the lowest in the brain of the sheep.

Immunohistochemical study of normal and mange (S. scabiei var. rupicaprae) infested chamois (Rupicapra rupicapra L.) skin.

The immunohistochemical study of chamois (Rupicapra rupicapra L.) skin showed that a limited number of available monoclonal and polyclonal antibodies expressed reactivity with skin cell components. These included cytokeratins, vimentin, desmin, neuron-specific enolase and S-100 protein with almost the same distribution pattern as already described in the skin of humans and animals. Antibodies used for labelling skin-associated lymphoid tissues and other cells with the immunologic function in human skin failed to demonstrate these cells in the chamois skin with the exception of LCA and OKT6 antibodies. Epidermal Langerhans cells were reliably demonstrated only by the enzyme histochemical method for adenosine triphosphatase, while the majority of mononuclear cells in dermal infiltrates showed a strong immunoreaction with OKT6 antibody. The histologic and histochemical analysis showed that the dermal infiltrations in infested skin consisted of macrophages, lymphocytes, granulocytes, mastocytes and fibroblasts. The chamois skin affected with sarcoptes mange showed a significant loss of cytokeratins in the epidermis and its derivatives. Particular keratinocytes showing nonspecific staining with several antibodies were also described and discussed in this paper.

Vimentin- and desmin-positive cells in the moulting budgerigar (Melopsittacus undulatus) skin.

The distribution of vimentin- and desmin-positive cells in the budgerigar (Melopsittacus undulatus) dermis was investigated by means of immunohistochemical reactivity with the commercially available (Euro-Diagnostics) polyclonal antibodies. The staining pattern for vimentin in the paraffin sections was generally comparable to that in other animal species with regard to endothelial cells, vascular wall cells, muscle cells and fibroblasts. The modified Schwann cells in the inner core of the Herbst corpuscles reacted distinctly with anti-vimentin and anti-desmin. Some connective tissue cells in the superficial dermal layer, in the feather papilla and along the pulp core inside of the regenerating feathers were particularly well stained with anti-vimentin. Fibroblast-like cells of the regenerating feathers, particularly at the base of the pulp, also reacted strongly with anti-desmin. The findings were discussed with regard to references.

Transfer of planar and non-planar chlorobiphenyls, 4,4'-DDE and hexachlorobenzene from blood to milk and to suckling infants.

The transfer coefficients of tetra- and hexachlorobiphenyls (PCB-54; -80; -155; and -169), HCB and 4,4'-DDE between milk and blood were monitored for eight weeks in sheep previously administered with these compounds by intramuscular injection. Analyses were performed by high resolution gas chromatography. The milk/blood ratio on a fat basis was close to 1 for HCB, over 1 for 4,4'-DDE, PCB-155, and -169 and below 1 for PCB-54 and -80. It is speculated that the deviation from the ratio 1 results from the interactions of organochlorines with (lipo)proteins in blood and/or milk. In milk, the enrichment of 4,4'-DDE, PCB-155 and -169 was observed. The relative toxicity expressed by the toxic equivalent (on a fat basis) was approximately 2.5 times higher in milk than in blood.

Morphometric analysis of fetal rat lung after the administration of Pyralene-3000.

The effects of the application of commercial low chlorinated PCB Pyralene-3000 on rat lung development during late gestation were studied. In the developing lungs (17.5 to 21.5 days) the volume density (Vv) of a particular compartment and length density of potential air spaces (Lv) were determined. Significant difference (p < 0.01) in epithelium to mesenchyme ratio (Epi/Mes) occurred between the control and treated groups on day 20.5 due to an increased volume proportion of mesenchyme (Vvmes) in the treated group suggesting a small delay in maturation. Decreased volume proportion of potential airspaces (Vvair) was observed on days 18.5 and 20.5. However, no differences were found on day 21.5 in any variables studied.

Combined histochemical and immunohistochemical determination of three muscle fibre types in a single section of porcine skeletal muscle.

The method of successive staining for SDH and immunohistochemical detection of fast contracting muscle fibres in pig muscle tissue has been used for demonstration of three muscle fibre types (slow oxidative, SO; fast metabolic intermediate, FI; fast glycolytic, FG). It gives basic information on contractile and metabolic muscle fibre properties in a single frozen section and can be well applied to the pale, soft and exudative (PSE) changes affecting pig muscles.

Calcitonin- and somatostatin-positive cells in thyroid gland of pigs at different ages.

Immunohistochemical studies were carried out on calcitonin-, somatostatin- and serotonin-reactive cells in newborn pigs and pigs at 3 weeks and 7 months old. The aim of these studies was to examine if the expression of various bioactive substances by parafollicular cells in the pig thyroid varied during development. The volume density of the follicular epithelium was nearly the same in newborn and 3-week-old piglets and significantly lower in 7-month-old animals. The volume density of calcitonin-positive cells, expressed as a percentage of the follicular epithelium density, was similar in young animals, being 12.10% and 13.03% in newborn and 3-week-old piglets, respectively. A small but significant increase to 14.40% was seen in 7-month-old pigs. Somatostatin-positive cells formed a much smaller population at all time points, but these also showed a significant increase with age (0.13%, 0.17% and 0.52% of follicular epithelium density in newborn, 3-week- and 7-month-old pigs, respectively). However the changes in the volume density of somatostatin-positive cells correlated inversely with thyroid activity, the density being highest when the activation index was lowest, suggesting that thyroid activity may be regulated by an increase in the synthesis of this inhibitory peptide. Serotonin-positive cells were extremely rare at all time points and their volume density was not calculated.