Abstract: Dexamethasone (Dex) is a synthetic glucocorticoid
that is used in therapy. However prolonged treatments with high
doses are often required. This causes side effects that interfere with
the activity of several endocrine systems, including the gonadotropic
axis.
The aim of our study is to determine the effect of Dex on testicular
function in prepubertal Wistar rats.
Newborn Wistar rats are submitted to intraperitoneal injection of
Dex (1μg of Dex dissolved in NaCl 0.9% / 5g bw) for 20 days and
then sacrificed at the age of 40days. A control group received NaCl
0.9%. The rat is weighed daily. The plasmatic levels of testosterone,
LH and FSH were measured by radioimmunoassay. A histomorphometric
study was performed on sections of testis.
Treated groups showed a significant decrease in body weight (p
Abstract: The aim of the present study is to analyze the generation of osteoporotic vertebral bone induced by lack of calcium during growth period and analyze its effects for disc degeneration, based on biomechanical and histomorphometrical study. Mechanical and histomorphological characteristics of lumbar vertebral bones and discs of rats with calcium free diet (CFD) were detected and tracked by using high resolution in-vivo micro-computed tomography (in-vivo micro-CT), finite element (FE) and histological analysis. Twenty female Sprague-Dawley rats (6 weeks old, approximate weight 170g) were randomly divided into two groups (CFD group: 10, NOR group: 10). The CFD group was maintained on a refmed calcium-controlled semisynthetic diet without added calcium, to induce osteoporosis. All lumbar (L 1-L6) were scanned by using in vivo micro-CT with 35i.un resolution at 0, 4, 8 weeks to track the effects of CFD on the generation of osteoporosis. The fmdings of the present study indicated that calcium insufficiency was the main factor in the generation of osteoporosis and it induced lumbar vertebral disc degeneration. This study is a valuable experiment to firstly evaluate osteoporotic vertebral bone and disc degeneration induced by lack of calcium during growth period from a biomechanical and histomorphometrical point of view.
Abstract: A series of Ti based shape memory alloys with
composition of Ti50Ni49Cr1, Ti50Ni47Cr3 and Ti50Ni45Cr5 were
developed by vacuum arc-melting under a purified argon atmosphere.
The histometric and corrosion evaluation of Ti-Ni-Cr shape memory
alloys have been considered in this research work. The alloys were
developed by vacuum arc melting and implanted subcutaneously in
rabbits for 4, 8 and 12 weeks. Metallic implants were embedded in
order to determine the outcome of implantation on histometric and
corrosion evaluation of Ti-Ni-Cr metallic strips. Encapsulating
membrane formation around the alloys was minimal in the case of all
materials. After histomorphometric analyses it was possible to
demonstrate that there were no statistically significant differences
between the materials. Corrosion rate was also determined in this
study which is within acceptable range. The results showed the Ti-
Ni-Cr alloy was neither cytotoxic, nor have any systemic reaction on
living system in any of the test performed. Implantation shows good
compatibility and a potential of being used directly in vivo system.
Abstract: The present investigation aimed to study the
histomorphometric characterizations of the thyroid gland of the duck.
Five adult male and five adult female ducks were used in the
experiment. Results showed that the overall histological structure of
the thyroid gland of the duck were similar to those of the other
vertebrae. The gland consisted of roughly spherical randomly
distributed micro and macrofollicles with very little interstitial tissue
between them. Each follicle is lined by a single layer of epithelial
cells enclosing a cavity, the follicular cavity, which is filled with
colloid. Ultrastructural findings showed that the apical surface of the
follicular cells bears a variable number of short, irregularly
distributed microvilli which are apparently more numerous on the
columnar cells than on the lower, relatively inactive cells.
Mitochondria and rough endoplasmic reticulum occupy the
subnuclear region of the follicular cell, whereas the Golgi complex,
free ribosomes and colloid droplets were found in the apical
cytoplasm. At light or electron microscopic levels, there was no sex
difference in histomorphometric characteristics of the thyroid
glands.ls.
Abstract: The aim of the present investigation was to compare
sex differences in thyroid gland structure of rabbits. Five adult male
and five adult female (3.1-3.5 kg body weight) New Zealand white
rabbits were used in the experiment. Results showed that at light
microscopic level, there was no sex difference in microscopic
appearance of the thyroid glands. At electron microscopic level,
however, the mitochondria and the microvilli of the follicular cells
are more numerous and the Golgi complex is also more extensive in
male rabbits in comparison to females. Results obtained from
micrometric measurements showed that the volume density of the
follicles is higher in males than in females, but the differences are not
statistically significant .The volume density of epithelium and the
height of follicular cells are significantly greater in males than in
females and reverse is true about the volume density of interstitium
(p