Marco Zedda

Comparative Bone Histology of Adult Horses (Equus caballus) and Cows (Bos taurus)

Bone microstructure of domestic herbivores is still not completely understood. Indeed, works focused on the bone histology of numerous Mammalian species frequently led to misunderstandings because of the high number of variations such as the kind of bone, section orientation, species, breed and age. Moreover, attempts to identify the species in archaeozoological studies by a mere qualitative approach have not been encouraging and in recent years quantitative methods, based on image processing and statistical analysis, have appeared. The present study was undertaken to determine whether morphometrical and morphological differences exist in the compact bone structure of the femur and humerus between horses and cows. Measurements such as area, perimeter, minimum and maximum diameter of osteons and Haversian canals as well as the osteonal density were carried out on cross sections of eight humeri and eight femurs of the two herbivores investigated. In agreement with other authors, the qualitative investigation confirmed that the compact bone of horses and cows can be classified as dense Haversian tissue. Osteons of the horse were more numerous and composed of a higher number of well‐defined lamellae when compared with the cow. Diameter, perimeter and area of osteons and Haversian canals were always higher in horses than in cows and this pattern could be related to the different locomotor behaviour of these animals.

Scaling of Haversian canal surface area to secondary osteon bone volume in ribs and limb bones

Studies of secondary osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing osteon canal size with increased osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, osteonal wall area, B.Ar) in a broad size range of mature (quiescent) osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib osteons.

Morphological and functional changes induced by the amino acid analogue 3-nitrotyrosine in mouse neuroblastoma and rat glioma cell lines

The amino acid analogue 3-nitrotyrosine (3-NT) is formed in neural cells as a result of the intense stimulation of NMDA glutamate receptors. 3-NT is involved in the pathology of diverse neurodegenerative disorders. The aim of our work is to investigate the sensitivity of cultured neural and glial cells to 3-NT. We report the morphological changes detected on mouse neuroblastoma (C1300) and rat glioma (C6) cell lines cultured in a medium supplemented with different 3-NT concentrations. Western blot displayed a selective incorporation of 3-NT into a single protein that co-migrated with tubulin. Both cell lines showed morphological changes, nuclear suffering, decreased viability and growth inhibition (starting from 90 and 360 microM for C1300 and C6, respectively). Such effects were dose-dependent, though glioma cells showed severe alterations at higher 3-NT concentrations. Our results point out a higher 3-NT sensitivity in the neural cells studied in comparison with those of glial origin. The dramatic toxicity of 3-NT in neural cells suggests further investigations focused on the biochemical mechanisms at the roots of neurodegenerative diseases.

Ancient Pompeian Dogs – Morphological and Morphometric Evidence for Different Canine Populations

This article examines the morphological features of the dog during the Roman Age on the basis of osseous and dental remains dug up in Pompeii. The material, consisting of 113 canine bones and teeth, was subjected to both morphological and morphometrical analyses and was compared with modern canine breeds. In most cases, the age at death, shoulder height and other phenotypic features were ascertained. The examined Pompeian canine population fell mainly into two categories: small‐ and large‐sized animals. Among the former, one brachycephalic and two dolichocephalic subjects were included. Such morphological features agree with what is described in numerous texts and appears in mosaics, bas‐reliefs and frescoes of the Roman Age. As small‐sized dogs cannot be classified as Canes Venatici (sporting dogs), Canes Villatici (watch dogs) and Canes Pastorales (shepherd dogs) according to Columellas De re rustica, these animals may be considered as lapdogs.

Aromatase immunoreactivity in fetal ovine neuronal cell cultures exposed to oxidative injury

A lot of evidence testifies that aromatase is expressed in the central nervous system where it has been detected not only in hypothalamic and limbic regions but also in the cerebral cortex and spinal cord. In physiological conditions, aromatase is expressed exclusively by neurons, where it has been mainly found in cell bodies, processes and synaptic terminals. Moreover, primary cultured cortical astrocytes from female rats are more resistant to oxidant cell death than those from males, suggesting a protective role of estradiol. The aim of this study was to evaluate changes in aromatase expression in response to 3-nitro-L-tyrosine, a marker of oxidative stress, in primary neuronal cell cultures from brains of 60-day old sheep fetuses. Cells were identified as neurons by using class III β-tubulin, a marker of neuronal cells. Two morphological types were consistently recognizable: i) bipolar cells with an oval cell body; ii) multipolar cells whose processes formed a wide net with those of adjacent cells. In situ hybridization technique performed on 60-day old fetal neurons revealed that in baseline conditions aromatase gene expression occurs. Importantly, cells exposed to 360 µM 3-nitro-L-tyrosine were fewer and showed more globular shape and shorter cytoplasmic processes in comparison to control cells. The immunocytochemical study with anti-aromatase antibody revealed that cells exposed to 360 µM 3-nitro-L-tyrosine were significantly more immunoreactive than control cells. Thus, it can be postulated that the oxidant effects of the amino acid analogue 3-nitro-L-tyrosine could be counterbalanced by an increase in aromatase expression that in turn can lead to the formation of neuroprotective estradiol via aromatization of testosterone.

Morphology, Morphometry and Spatial Distribution of Secondary Osteons in Equine Femur

A high number of differences exist in bone histological features depending on the species, breed, age and bone. Moreover, osteon distribution may vary in the different sides of a bone as a consequence of different biomechanical strains. The aim of this work was to study the distribution and morphology of osteons in different sides of the equine femoral diaphysis with the attempt to correlate them to the main strains operating on them. The following parameters of secondary osteons and Haversian canals were measured in the transverse sections of diaphyses: perimeter, area, minimum and maximum diameter, eccentricity and osteon population density. A typical Haversian tissue was observed with elliptic secondary osteons consisting in about 10 well‐defined lamellae surrounding a circular Haversian canal. Quantitative analysis displays a different population density of secondary osteons depending on the side. The caudal and medial sides, where compression strains are higher, have more secondary osteons in comparison with the cranial and lateral sides, where tension strains are prevalent. These data suggest that secondary osteon population density may depend on the predominant strains. Even the elliptical shape of secondary osteons may be related to biomechanical strains, as their major axes are oriented cranio‐caudally parallel to prevalent strains.

Aluminum promotes neuronal plasticity events in a mouse neuroblastoma cell line

The effects of aluminum(III) on microtubular meshwork have been investigated using cultured murine neuroblastoma cells grown in a medium containing aluminum lactate at defined metal concentrations (10-20 microM). A role of aluminum(III) in promoting neuronal plasticity events is suggested. These events including sprouting and neurite outgrowth are associated with an increased tyrosine-tubulin (Tyr-Tub) expression, which can be due to the enhanced needs of recently formed, highly dynamic microtubules typical of neuronal plasticity. After 48 and 72 h aluminum exposure, an upregulation of Tyr-Tub expression is detected and this is concentration-dependent. A high amount of Tyr-Tub is observed also in non-treated cells, although later than in aluminum-exposed cells. Thus, it is possible that aluminum(III) accelerates neuronal plasticity events, for which Tyr-Tub is confirmed to be a useful marker.

Androgen receptor immunoreactivity in rat occipital cortex after callosotomy

Gonadal steroidogenesis can be influenced by direct neural links between the central nervous system and the gonads. It is known that androgen receptor (AR) is expressed in many areas of the rat brain involved in neuroendocrine control of reproduction,such as the cerebral cortex.It has been recently shown that the occipital cortex exerts an inhibitory effect on testicular stereoidogenesis by a pituitary-independent neural mechanism. Moreover, the complete transection of the corpus callosum leads to an increase in testosterone (T) secretion of hemigonadectomized rats. The present study was undertaken to analyze the possible corticocortical influences regulating male reproductive activities. Adult male Wistar rats were divided into 4 groups: 1) intact animals as control; 2) rats undergoing sham callosotomy; 3) posterior callosotomy; 4) gonadectomy and posterior callosotomy. Western blot analysis showed no remarkable variations in cortical AR expression in any of the groups except in group I where a significant decrease in AR levels was found. Similarly, both immunocytochemical study and cell count estimation showed a lower AR immunoreactivity in occipital cortex of callosotomized rats than in other groups. In addition, there was no difference in serum T and LH concentration between sham-callosotomized and callosotomized rats. In conclusion, our results showthat posterior callosotomy led to a reduction in AR in the right occipital cortex suggesting a putative inhibiting effect of the contralateral cortical area.

Differences in femoral morphology between sheep (Ovis aries) and goat (Capra hircus): macroscopic and microscopic observations

It is often difficult, if not impossible, to separate postcranial elements of species, such as sheep and goats. Distinguishing between the skeletal remains of these species is important in a variety of scientific fields, such as comparative anatomy, taxonomy, biomechanical engineering, as well as zooarchaeology and palaeontology. The aim of this study was to assess morphological and morphometric differences of microscopic and macroscopic characteristics of the femur of sheep and goats, to be used to distinguish between these species. Approximately one hundred sheep and goat femora were examined. Microscopic results indicated that osteon and Haversian canal diameters are parameters useful to the distinction between sheep and goats. Twelve macroscopical features, which successfully separated goat and sheep femora, were identified and discussed, four of which were described for the first time with a mathematical approach. These differences could be related to the behavioural and locomotion patterns of the two species.

Fonni’s dog: morphological and genetic characteristics for a breed standard definition

Abstract Italy is home to several populations of native dogs that reside only in certain demographic regions. Such dog populations have not been under tight selection by humans and, as such, have never been officially recognised as breeds. One such population is the ‘Cane Fonnese’ or Fonni’s Dog, which features uniform morphologic and behavioural traits that reproduce across generations, thus qualifying Fonni’s Dog as a true breed eligible for recognition by national or international breed registries. The Fonni’s Dog population examined in the present work is native to Sardinia, where they are used as property or livestock guardian dogs. As such, they are greatly appreciated by the local populace. We have carried out morphological evaluations on 200 Fonni’s Dogs with the aim of developing a standard breed definition upon which the foundation of the Fonni’s Dog breed can be based. We have also reported genetic data of the Fonni’s Dog compared to four other established breeds sampled from the same geographic area.