Osteopontin expression in healing wounds of horses and in human keloids.

REASONS FOR PERFORMING STUDY: Convincing evidence shows that persistent or excessive expression of osteopontin (OPN) is linked to fibroproliferation of various organs in laboratory animals and in man, such that its downregulation is a logical therapeutic objective. OBJECTIVES: To investigate OPN expression in an equine model of wound healing and in clinical specimens of equine exuberant granulation tissue and human keloids in an effort to better understand the contribution of this protein to inflammation-associated skin fibrosis. STUDY DESIGN: Description of gene and protein expression in an experimental equine model of wound healing and clinical specimens in horse and man. METHODS: Osteopontin gene expression was evaluated by quantitative PCR, while protein expression was investigated by means of immunohistochemical staining. RESULTS: Quantitative PCR showed that the OPN gene is expressed in normal intact skin of horses and continues to be expressed during the wound-healing process. An increase in gene expression was observed throughout the phases of wound healing, with a final decrease at wound closure. The protein was not detected in normal skin. Keratinocytes in wound-edge samples did not express the protein, whereas dermal immunoreactivity was confined to inflammatory cells. Healed wounds were devoid of staining. Equine exuberant granulation tissue showed immunoreactivity of the surrounding epidermis, infiltrating neutrophils, mononuclear cells, endothelial cells and fibroblasts. Human keloids showed OPN immunoreactivity throughout the epidermis as well as in mononuclear cells and scattered fibroblasts. CONCLUSIONS: Immunohistochemical data show a different pattern of expression between normally healing and fibrotic wounds (exuberant granulation tissue and keloids), thus suggesting a role in fibroproliferation in horses and man.

Comparative analysis of senescent exorbital lacrimal glands in male and female albino rats.

In our previous study we described a bilateral-macroscopic and structural dimorphism of young rat exorbital lacrimal gland (Loewenthal's gland), which was the probable cause of the bibliographic discrepancies in the entity and the onset of its sexual dimorphism. Relevant literature also reported sex-dependent alterations in gland structure during senescence. The present study aims to carry out a comparative analysis on age-dependent changes in glands of both sides from male and female rats, using histological, histochemical and transmission electron microscopy, to evaluate whether the gland bilateral-macroscopic and structural dimorphism might influence the kind of alterations which occur in senescence. Our findings indicate that the macroscopic and structural side-specific dimorphism is not so evident in comparison with young rats. The side-specific dimorphism is evident only in male rats, in which the roundish gland appears to be more Sudan-positive in comparison with the ellipsoidal gland. The gland bilateral-macroscopic and structural dimorphism, although more evident in comparison with young animals, does not seem to influence these kinds of alterations due to senescence, a time-window in which we still observed some sexual differences also in more aged rats.

Expanded polytetrafluoroethylene as tendon replacement: an experimental study in chickens.

We designed an experimental animal model (in chickens) to assess the potential applications, above all in hand surgery, of an expanded polytetrafluoroethylene (e-PTFE) graft as a replacement for a natural tendon. The results of macroscopic, histological, and functional observations made five weeks, and three, four, five, and six months after implantation showed that the e-PTFE seemed to be a good replacement for tendons, because it integrated well with surrounding tissue and permitted good functional recovery within a reasonable time period.

Bilateral dimorphism of Loewenthal's gland in young male albino rats: an ultrastructural investigation.

This study represents a further contribution to our knowledge about the structure of Loewenthal's gland. There are several divergences in the available literature on the topic, concerning both the histological and ultrastructural findings. However, in these studies, the authors did not take into account the potential influence of a putative side-dependent dimorphism previously reported by us. We therefore carried out histological and electronmicroscopic observations specifically aimed at evaluating the importance of the gland shape for its structure. In particular, in male albino rats aged 70-120 days, we compared the structure of the left and right glands. Depending on the side undergoing morphological investigation, we observed differences in the acini, cells, nuclei, endoplasmic reticulum, Golgi apparatus and granular content. Apart from slight individual differences, we found that structural variations were most frequently observed in glands displaying a more evident macroscopic side-specific dimorphism. Our findings demonstrate that several conflicting data in the literature dealing with the structure of Loewenthal's glands might be explained by the morphofunctional side-dependent dimorphism of the organ.

Long-term exposure to noise modifies rat adrenal cortex ultrastructure and corticosterone plasma levels.

Female rats were exposed to noise 6 h daily for 7 or 21 days running. The effects of stress were evaluated both on adrenal cortex ultrastructure and on plasma corticosterone levels. Subcellular examination showed a marked involvement of each zona of the adrenal cortex. In particular, we observed various alterations, the most frequent consisting of diluted matrix and cristolysis of mitochondria and swelling of smooth endoplasmic reticulum membranes. These morphological changes were most prominent after longer exposure to noise. Similarly, corticosterone plasma levels significantly increased over the time of application of noise stimulus. The present findings indicate that prolonged exposure to loud noise induced structural and functional modifications in the adrenal gland. These data might be potentially relevant in contributing to explain the effects induced in humans exposed to loud noise in a variety of environmental conditions.

Stress-induced morphohistochemical and functional changes in rat adrenal cortex, testis and major salivary glands.

The effect of repeated stress (1 h of daily immobilization for seven consecutive days) on the adrenal cortex of young adult male albino rats was evaluated by morphohistochemical methods and plasma assays; at the same time, testes and major salivary glands, as steroid-producing and -depending organs, respectively, were examined. Morphological and histochemical changes were found in the adrenal cortex, testis and submaxillary gland, though varying in degree and extent depending on the gland examined. Corticosterone and progesterone plasma levels increased, in agreement with the lipid depletion observed in the zona fasciculata, while testosterone and androstenedione decreased, as confirmed by the less marked enzymatic activity in the Leydig cells. The study thus proves that repeated stress, even of temporary duration, is able to influence directly or indirectly the morphofunctional state of the three examined glands, suggesting a functional linkage.

Clinical and experimental evidence of inhibition of testosterone production by suramin.

The effect of suramin on testosterone production was evaluated in cancer patients, adult male rats, rat Leydig cells, and NCI-H295 human adrenal cancer cells. Testosterone plasma levels markedly decreased in 14 patients receiving suramin as a therapy for refractory cancer, and in 8 of them, the plasma LH and/or FSH levels increased beyond the normal range. The hCG stimulation test (5000 IU, im) was performed in 8 patients and induced an average 2.1-fold increase in testosterone levels over baseline values. Testicular histology after suramin treatment was available in 1 patient who died of progressive disease; this revealed atrophy of seminiferous tubules and reduced Leydig cells in the interstitium. A significant reduction in plasma testosterone was also observed in rats given 18 mg/kg suramin, ip, twice weekly for 8 weeks, whereas plasma LH and FSH levels did not change significantly. Cytohistochemistry of testes from suramin-treated rats showed a reduced number of 3 beta-hydroxysteroid dehydrogenase-positive cells within the interstitium compared to controls, and light microscopy revealed severe impairment of spermatogenesis. Suramin inhibited the production of testosterone by isolated rat Leydig cells as well as the conversion of pregnenolone to progesterone by the 3 beta-hydroxysteroid dehydrogenase enzyme extracted from rat testes, with 50% inhibitory concentrations (IC50 values) of 108.2 and 87.5 micrograms/mL, respectively. Furthermore, suramin reduced the release of testosterone into the culture medium of NCI-H295 adrenal cancer cells with IC50 values of 91.2 and 83.9 micrograms/mL after 6 and 12 days, respectively. These data provide the first evidence in patients that suramin treatment produces a marked reduction in the circulating levels of testosterone, a result that was also obtained in experimental models.

Morphohistochemical relationships between adrenal cortex and major salivary glands in response to chronic suramin treatment.

Adult male albino rats received 18 mg/kg i.p. of suramin twice a week, comparable to the human therapeutic situation. Sacrifices took place after 30 and 60 days of treatment. Adrenal cortex and major salivary glands were examined, using morphological and histochemical methods, in order to obtain a) confirmation of adrenocortical damage reported previously and b) original data for the major salivary glands. In rats the submaxillary gland in particular has already been found to be closely related to the functional conditions of the adrenal cortex. In all organs examined, alterations already evident in 30 day-treated rats, were constantly more marked and widespread in 60 day-treated animals. At the end of the treatment the adrenal cortex showed morphological (poor differentiation of the zona glomerulosa, hypertrophic cell clusters in the zona fasciculata) and histochemical (different distribution of neutral lipids, cholesterol and delta 5-3 beta-hydroxysteroid dehydrogenase) changes. Damage (vacuolizations, lymphocytic infiltrates) observed in major salivary glands was shown to be more marked and widespread in the submaxillary gland, confirming its functional dependence on adrenocortical activity.

Levels of carnitine and glycogen in rabbit tissues during development.

This study attempts to add further light on the development of metabolic pathways in mammalians from fetal to post-natal life, by examining ongoing modifications of carnitine (in terms of total acid soluble, short chain esterified and free carnitine) and glycogen levels in the liver, heart, muscle and brain of rabbit during development.

Morphohistochemical characterization of suramin--induced chronic toxicity in rat kidney.

The effects of a chronic administration of suramin were evaluated on renal parenchyma of young rats. Animals were given suramin 18 mg/kg i.p. twice a week for two months, a treatment schedule equivalent to that used in cancer patients. At the end of the treatment, suramin concentrations in plasma and kidney were assayed and a morphohistochemical examination of renal parenchyma was carried out. Marked and widespread alterations were detected in both cortex and medulla and were associated with elevated tissue suramin levels exceeding 5 mg/g of tissue. The present data demonstrate that suramin induces a severe chronic renal damage in the rat, associated with high drug tissue levels.

On the presence and ultrastructure of valves in the lymphatic vessels of the canine ovary.

The origin and course of the intraovarian lymphatic vessels were examined by means of histologic studies of the gonads of pubertal female dogs. The small vessels that were present in the cortex near the follicles and corpora lutea flowed into an anastomotic network located at the margins of the medulla. Vessels of larger caliber were found to originate from the medulla and to reach the hilum by an approximately rectilinear pathway. In concordance with their previous findings in other species, the authors identified numerous semilunar valves in the lymphatic vessels of the cortex. Their ultrastructure is described.

Effects of stress on adrenal steroidogenesis blockade by aminoglutethimide.

After one week of AG-treatment, the adrenal cortex reveals a marked storage of lipids and cholesterol, as well as a decrease in haematic corticosterone and progesterone levels. On the contrary, when AG-treatment is associated with stress, an increase in plasma corticosterone and progesterone levels occurs, together with a less evident lipidic storage in the adrenal cortex. These results seem to indicate the possibility that, during stress, hypothalamo-hypophysis axis activation is able to remove, at least partially, the adrenal biosynthesis blockade operated by AG-administration.

[Morpho-histochemical observations on the liver parenchyma of adult albino rats subjected to acute acoustic stress]. / Osservazioni morfo-istochimiche su parenchima epatico di ratti albini adulti sottoposti a stress acustico acuto.

The hepatic noradrenergic innervation and the glycogen cellular content, after acoustic stress, were studied by the fluorescence and P.A.S. methods, respectively, in 7-month-old male albino rats exposed to continuous intense noise for 60' and 8 hours. While the 60'-treatment did not cause noteworthy changes in adrenergic fibers and a decrease in PAS-positive material, the 8 h.-treatment induced a significant increase of catecholamines content, in addition to a non homogeneous response to PAS reaction by hepatocytes surrounding the portal spaces or the lobular central veins. The authors ascribe the effect of the 8 h.-treatment to a partial adaptation of hepatocytes to acoustic stress.

Morphofunctional research on the effects of steroid-stimulating and -inhibiting drugs on the major salivary glands of rats.

Adult male albino rats underwent chronic treatment with synthetic adrenocorticotropin and Dexamethasone, and were examined for a long time after the administration of these drugs. The major salivary glands were observed by means of histological and histochemical methods. We did not find enzymatic modifications whereas morphological damage was particularly evident in the submaxillary and parotid glands, especially all after Dexamethasone treatment; this damage is to be found up to at least 14 days after the end of treatment.

Age-related changes in the recovery of noradrenaline content in sympathetic fibres after reserpine treatment.

The aim of the present study was to evaluate noradrenaline recovery times in sympathetic fibres after reserpine administration by using fluorescence histochemical techniques. The spleen, the kidney, and the large intestine were examined 24 h to 15 d after reserpine treatment, in both young and aged male Sprague-Dawley rats, in order to establish not only the possible differences in recovery times of the various organs, but also if senescence can influence these times. The complete restoration of the noradrenaline content took place sooner in younger rats than in aged ones, and, within the same age-group, the recovery was quicker in the spleen and needed longer times in the large intestine, particularly in aged rats.

Histochemical research into the facial caruncle of the Muscovy duck (Cairina moschata domestica L.) and its relationship with the adrenal glands and gonads.

Histochemical studies carried out on prepuberal and adult, males and females, Muscovy ducks (the Black ancestral variety) showed that the beginning of the facial caruncle is caused mainly by local androgenic activities. In adult males, support for this organ comes from the steroid hormones originating from the adrenal gland and testis. In adult females, caruncular androgenic activity also seems to be necessary for the support of this organ.

Morphological and histochemical study on the adrenal cortex of the dexamethasone-treated albino rat.

Morphological and histochemical examinations of the changes induced in the adrenal cortex by the administration of Dexamethasone (Decadron phosphate) to rats for 14 consecutive days were made at intervals during a 28-day post-treatment period, in order to follow the histo-functional recovery of this gland from the changes induced. The modifications that had occurred by the end of the treatment consisted of a decrease in the width of the zona fasciculata and the zona reticularis, an increase in the lipidic content, and degenerative mitochondrial signs in the zona glomerularis. Seven days after discontinuing treatment, we observed the disappearance of the zona intermedia, which reappeared on the 14th day after treatment. From this day on, the adrenal gland tended progressively to complete recovery. Dexamethasone therefore produces both short-term and long-term morphological and histochemical changes in all the adrenocortical zonae.