Behavioral and hormonal effects of prolonged Sildenafil treatment in a mouse model of chronic social stress.

Chronic social defeat can inhibit the reproductive system of subordinate males and causes behavioral deficits. Sildenafil treatment increases mice testosterone levels through its effects on Leydig cells of mice and it has been found to work as an antidepressant drug both in humans and in animal models. Since previous findings showed that sildenafil can counteract the inhibitory effects of chronic social defeat on agonistic, reproductive and anxiety-like behaviors of subordinate male mice, we investigated whether these behavioral outcomes can be explained by Sildenafil stimulation of testosterone. CD1 mice underwent an intruder-resident paradigm. After the fifth day of test, subordinate mice were injected with either a 10 mg/kg Sildenafil or a saline solution for 4 weeks. The results of the present study showed that Sildenafil treatment increased counterattacking behaviors and sexual motivation of subordinate males in addition to limiting the increase in body weight often observed in subordinate mice following chronic psychosocial stress. Moreover, sildenafil treated mice showed a pattern of behaviors reflecting lower anxiety. In agreement with previous studies, Sildenafil also increased testosterone levels. These data demonstrate that sildenafil can counteract the effects of chronic stress, possibly through its stimulatory effects on Leydig cells. These data demonstrate that sildenafil might counteract the effects of chronic psychosocial stress through centrally and peripherally mediated mechanisms.

Effects of zoledronic acid and dexamethasone on early phases of socket healing after tooth extraction in rats: A preliminary macroscopic and microscopic quantitative study.

BACKGROUND: The exact pathogenesis of medication-related osteonecrosis of the jaw (MRONJ) is still unknown. The aim of this paper was to investigate the effects of zoledronic acid and dexamethasone on the early phases of socket healing in rats subjected to tooth extractions. MATERIAL AND METHODS: Thirty male Sprague-Dawley rats were divided into 2 groups: pharmacologically treated group (T, n=20) and non-pharmacologically treated group (C, n=10). T group rats received 0.1 mg/Kg of zoledronic acid (ZOL) and 1 mg/Kg of dexamethasone (DEX) three times a week for 10 consecutive weeks. C group rats were infused with vehicle. After 9 weeks from the first infusion, first maxillary molars were extracted in each of the rats. Quantitative macroscopic and microscopic analysis was performed to evaluate socket healing 8 days after extraction. RESULTS: Pharmacologically treated rats showed significant inhibition of bone remodeling. Connective tissue/alveolar bone ratio, osteoclast number and woven bone deposition were significantly reduced in group T compared to group C. Conversely, the proportion of necrotic bone was higher in group T compared to group C (0.8% and 0.3%, respectively. P=0.031). ZOL plus DEX do not cause gross effects on socket healing at a macroscopic level. CONCLUSIONS: Our findings confirmed that exposure to ZOL plus DEX impairs alveolar wound repair. Inhibition of osteoclastic resorption of socket walls after tooth extraction and the inability to dispose of the necrotic bone may be considered the initial steps of MRONJ onset.

Porcine sclera as a model of human sclera for in vitro transport experiments: histology, SEM, and comparative permeability.

PURPOSE: To evaluate porcine sclera as a model of human sclera for in vitro studies of transscleral drug delivery of both low and high molecular weight compounds. METHODS: Human and porcine scleras were characterized for thickness and water content. The tissue surface was examined by scanning electron microscopy (SEM), and the histology was studied with hematoxylin-eosin staining. Comparative permeation experiments were performed using three model molecules, acetaminophen as the model compound for small molecules; a linear dextran with a molecular weight of 120 kDa as the model compound for high molecular weight drugs; and insulin, which was chosen as the model protein. Permeation parameters such as flux, lag time, and permeability coefficient were determined and compared. RESULTS: Human and porcine scleras have a similar histology and collagen bundle organization. The water content is approx 70% for both tissues while a statistically significant difference was found for the thickness, porcine sclera being approximately twofold thicker than human sclera. Differences in thickness produced differences in the permeability coefficient. In fact, human sclera was found to be two to threefold more permeable toward the three molecules studied than porcine sclera. CONCLUSIONS: The results obtained in the present paper prove that porcine sclera can be considered a good model for human sclera for in vitro permeation experiments of both low and high molecular weight compounds. In fact, if the different tissue thickness is taken into account, comparable permeability was demonstrated. This suggests a possible use of this model in the evaluation of the transscleral permeation of new biotech compounds, which currently represent the most innovative and efficient therapeutic options for the treatment of ocular diseases.

Characterization of rabbit ear skin as a skin model for in vitro transdermal permeation experiments: histology, lipid composition and permeability.

AIM: The aim of this work was to characterize rabbit ear skin in view of its use in transdermal permeation experiments. METHOD: The characterization included histological analysis of the tissue, qualitative and quantitative analysis of stratum corneum (SC) lipids, differential scanning calorimetry and permeation experiments (caffeine, nicotinamide, progesterone). As a reference, pig ear skin was used. RESULTS: The results obtained show that rabbit ear skin has a similar SC thickness compared to pig skin although the viable epidermis has a different structure. The lipid composition of rabbit SC was similar to pig SC but was characterized by a lower content of ceramides and a higher content of cholesterol esters and triglycerides. In terms of permeability, rabbit ear skin was 4-7 times less permeable to hydrophilic compounds, probably because of the higher lipophilicity of its SC. The permeability to progesterone was comparable between isolated pig epidermis and rabbit ear skin. CONCLUSION: Overall, the results obtained in this work support the usefulness of rabbit ear skin as barrier for skin penetration studies, for both lipophilic and hydrophilic permeants.

Effects of differential extraction of Verbena officinalis on rat models of inflammation, cicatrization and gastric damage.

Verbena officinalis L. is used in folk medicine for the treatment of inflammatory disorders, skin burns, abrasions, and gastric diseases. Extracts obtained with different solvents (methanol, VoME; enriched flavonoids, VoEF; supercritical CO2, VoCO2) were evaluated for anti-inflammatory, gastroprotective and cicatrizing activities. Additionally, the antioxidant capacity was determined in vitro. In order to confirm the activities investigated, histological observations were performed. All extracts induce a remarkable anti-inflammatory activity. The gastric damage is significantly reduced by all extracts administered, whereby the most pronounced protection is observed for the VoCO2 and VoEF extracts. Finally, a wound healing effect is obtained particularly by the CO2 extract, suggesting the presence of some lipophilic active principles. Histological evidence confirms the results evaluated with the animal procedures. The results obtained after oral administration of V. officinalis extracts are also in agreement with the antioxidant capacity evaluated in vitro, confirming the relationship between pharmacological activities and antiradical efficacy.

Anti-inflammatory, anti-nociceptive and antioxidant activities of Balanites aegyptiaca (L.) Delile.

The anti-inflammatory and anti-nociceptive activities of methanol (ME), butanol (BE) extracts and of two new saponins isolated from Balanites aegyptiaca bark were evaluated. The study was carried out in vivo and in vitro. The samples, extracts and pure substances, were intra-gastrically administered to animals. Two different animal models, the carrageenin-induced edema, in the rat, and acetic acid-induced writhing test in mice, were adopted. Moreover, the antioxidant power of extracts, fractions and individual constituents from Balanites aegyptiaca has been evaluated in vitro, using a method based on the Briggs-Rauscher (BR) oscillating reaction. Results obtained demonstrate that both ME or BE have a significant effect at the highest dose on the number of abdominal writhes induced by acetic acid, with a 38 and 54% inhibition respectively, but no significant difference was observed for extracts at the lowest dose and for the pure compounds compared with control animals. The same extracts exhibit a significant reduction on the rat paw edema. The inhibition produced by ME is about the same (28+/-3% lowest dose, 32+/-3% highest dose) after administration. A more evident effect is obtained by BE (41+/-3% and 68+/-6% respectively) and single saponins B1 and B2 (62+/-5% and 59+/-6% respectively) after oral administration. The antioxidant activity obtained seems to be in good accordance with the pharmacological results. The histological sections of rat paw confirm the antiflogistic activity of the plant extracts.

Efficacy of different Cynara scolymus preparations on liver complaints.

Cynara scolymus leaves extracts have long been used in folk medicine for their choleretic and hepatoprotective activities, that are often related to the cynarin content. These therapeutic properties are also attributed to mono- and di-caffeoylquinic acids and since commercial C. scolymus preparations can differ for their activities, we studied four extracts to evaluate, if present, a relationship between the hepatobiliary properties of the different preparations and their content in phenolics. The antioxidant activity of the commercial preparations examined was also considered in an in vitro system. The results showed that the extract with the highest content in phenolic derivatives (GAE) exerted the major effect on bile flow and liver protection. Also the results of the antioxidant capacity (BR) of the different preparations are in good agreement with the results obtained in vivo. On the contrary, administering rats with doses of chlorogenic acid, equivalent to those present in this extract, we did not observe any choleretic or protective action. An histopathological analysis of liver sections confirmed the biochemical results. Perhaps caffeoyl derivatives have a role in the therapeutic properties of C. scolymus extracts, as reported in literature for "in vitro" studies, but when administered alone, they are not so effective in exerting this action.

Anti-inflammatory and cicatrizing activity of Echinacea pallida Nutt. root extract.

Among the different species belonging to the Echinacea family, largely used in traditional medicine, Echinacea pallida, Echinacea purpurea and Echinacea angustifolia were investigated. These different species, due to their difficult identification, were commonly confused in the past and probably used indifferently for the same therapeutic purposes. In fact, the three species have in common, some pharmacological activities, based on the presence of active compounds that act additively and synergistically. Nevertheless, the composition of each species has slight variation in the amount of each active component. In particular, echinacoside, a caffeoyl derivative, is present in E. pallida and only in traces in E. angustifolia. It seems to have protective effects on skin connective tissue and to enhance wound healing. The anti-inflammatory and wound healing activities of echinacoside, compared with the ones of the total root extract of E. pallida and E. angustifolia, were examined in rats, after topical application. The tissues of the treated animals were evaluated after 24, 48 and 72 h treatment and excised for histological observation at the end of the experiment. Results confirm the good anti-inflammatory and wound healing properties of E. pallida and of its constituent echinacoside, with respect to E. purpurea and control. This activity probably resides in the antihyaluronidase activity of echinacoside.

Largely segregated parietofrontal connections linking rostral intraparietal cortex (areas AIP and VIP) and the ventral premotor cortex (areas F5 and F4).

Two functionally different cortical areas are located in the rostral part of the intraparietal sulcus (IP): the ventral intraparietal area (VIP), along the fundus of the sulcus, and the anterior intraparietal area (AIP), rostral in the lateral bank. VIP and AIP have functional properties comparable to those of the ventral premotor areas, F4 and F5, respectively. The aim of this study was to establish whether these intraparietal and premotor areas have direct and specific anatomical connections. Neural tracers were injected in F4, F5, and AIP in three macaque monkeys. The results showed that F4 and F5 are targets of strong projections from VIP and AIP, respectively, and that the linkage between F5 and AIP is highly selective. These data support the notion that parietofrontal connections selectively link areas displaying similar functional properties and form largely segregated anatomical circuits. Each of these circuits is possibly dedicated to specific aspects of sensorimotor transformations. In particular, the AIP-F5 circuit should play a crucial role in visuomotor transformation for grasping, the VIP-F4 circuit is possibly involved in peripersonal space coding for movement.

Superior area 6 afferents from the superior parietal lobule in the macaque monkey.

Superior area 6 of the macaque monkey frontal cortex is formed by two cytoarchitectonic areas: F2 and F7. In the present experiment, we studied the input from the superior parietal lobule (SPL) to these areas by injecting retrograde neural tracers into restricted parts of F2 and F7. Additional injections of retrograde tracers were made into the spinal cord to define the origin of corticospinal projections from the SPL. The results are as follows: 1) The part of F2 located around the superior precentral dimple (F2 dimple region) receives its main input from areas PEc and PEip (PE intraparietal, the rostral part of area PEa of Pandya and Seltzer, [1982] J. Comp. Neurol. 204:196-210). Area PEip was defined as that part of area PEa that is the source of corticospinal projections. 2) The ventrorostral part of F2 is the target of strong projections from the medial intraparietal area (area MIP) and from the dorsal part of the anterior wall of the parietooccipital sulcus (area V6A). 3) The ventral and caudal parts of F7 receive their main parietal input from the cytoarchitectonic area PGm of the SPL and from the posterior cingulate cortex. 4) The dorsorostral part of F7, which is also known as the supplementary eye field, is not a target of the SPL, but it receives mostly afferents from the inferior parietal lobule and from the temporal cortex. It is concluded that at least three separate parietofrontal circuits link the superior parietal lobule with the superior area 6. Considering the functional properties of the areas that form these circuits, it is proposed that the PEc/PEip-F2 dimple region circuit is involved in controlling movements on the basis of somatosensory information, which is the traditional role proposed for the whole dorsal premotor cortex. The two remaining circuits appear to be involved in different aspects of visuomotor transformations.

Parcellation of human mesial area 6: cytoarchitectonic evidence for three separate areas.

The mesial sector of primate area 6 is usually described as consisting of two distinct areas: the supplementary motor area (SMA or SMA proper) and the pre-SMA. Recent human brain imaging studies showed, however, that this subdivision is not completely satisfactory and that, most likely, SMA proper consists of two functionally distinct parts. In order to elucidate whether this hypothesis has an anatomical counterpart, we examined the cytoarchitectonic organization of human mesial area 6 in three brains of subjects deceased without any previous sign of neurological disorders. The data showed that human mesial area 6 consists of three separate cytoarchitectonic areas. Two of them are located mostly caudal to the vertical line transversing the anterior commissure (VCA line), the third one is located rostral to it. Given the location and some architectonic similarities between the two caudal areas, we named them caudal SMA (SMAc) and rostral SMA (SMAr). The area rostral to the VCA line is referred to as pre-SMA. The possible functional role of the three areas is discussed.

Scutumplasty: costal cartilage versus bone paté.

This study was carried out to evaluate the anatomical and hearing results of the reparation of attic defects in closed tympanoplasty. Reparation was carried out in 194 patients by using a costal cartilage allograft, and in 159 patients with a bone pate autograft. The follow-up was from 1 to 5 years. The study was not truly randomized owing to an occasional lack of allogenic costal cartilage. In the group 'costal cartilage' a partial resorption was observed in 5.7% and a complete resorption in 4.7% of the cases. In the group 'bone pate', partial resorption was observed in 5.5% and total resorption in 2.7% of the patients. Satisfactory hearing results were obtained in 86% of the patients of the group 'costal cartilage' and in 82% of the patients of the group 'bone paté'. Both graft materials may be recommended for repairing erosions caused by the cholesteatoma in the wall of the external auditory canal.

A hydrogel based on a polyaspartamide: characterization and evaluation of in-vivo biocompatibility and drug release in the rat.

This paper deals with the characterization of a new microparticulate hydrogel obtained by gamma irradiation of alpha, beta-poly[N-(2-hydroxyethyl)-DL-aspartamide] (PHEA). When enzymatic digestion of PHEA hydrogel was evaluated using various concentrations of pepsin and alpha-chymotrypsin no degradation occurred within 24 h. In-vivo studies showed that this new material is biocompatible after oral administration to rats. PHEA hydrogel was also studied as a system for delivery of diflunisal, an anti-inflammatory drug. In-vitro release studies in simulated gastrointestinal juice (pH 1 or 6.8) showed that most of the drug was released at pH 6.8. In-vivo studies indicated that diflunisal-loaded PHEA microparticles significantly improved the gastric tolerance and oral bioavailability of the drug in comparison with free diflunisal. These results suggest the potential application of PHEA hydrogel as a new delivery system for the oral administration of anti-inflammatory drugs.

The opioid peptide DAMME modulates histamine's content in gastric mucosa of the rat.

The effects of a synthetic Met-enkephalin analogue D-Ala2, MePhe4Met(O)5-ol]enkephalin (DAMME) (1 mg/kg. IP) on gastric damage produced by necrotizing agents (0.6 N HCl, ethanol 1 ml/rat, PO) were evaluated, and the correlation between histamine and opioids in stomach was investigated, Rats pretreated with DAMME bad significantly less severe lesions and lower histamine content in gastric tissue. The histamine level, expressed in mg/g of gastric tissue, changed from 0.41 +/- 0.10 of control animals to 1.33 +/- 0.12 for HCl and 1.51 +/- 0.20 for ethanol treatment, whereas in animals pretreated with DAMME the values were significantly reduced to 0.55 +/- 0.13 and 0.65 +/- 0.15. These results confirm a link between the gastroprotection produced by opioids and the modulation of histaminergic activity in the rat stomach.

Low-temperature heat-deproteinated compact bone to heal large bone defects.

The potential of low-temperature (400 degrees C), heat-treated bone matrix in osteorepair has been evaluated in vivo by implantation into defects artificially created in rodent tibia. Histological and ultrastructural analysis of the bone--implant interface has been carried out on samples obtained at 1 to 6 weeks from operation. The obtained data showed that calcined bone is well tolerated and does not cause acute or chronic inflammatory reactions. Osteoid tissue, tightly adhered to the implant, appears within 2 weeks of the operation, while after 6 weeks newly formed bone surrounds and infiltrates the implant. Of greater note, the detection of good adhesion between bone and implant ultrastructurally is demonstrated by the absence of fibrillar connective tissue at the interface. For these reasons, our preliminary observations suggest that low-temperature calcined bone (biological apatite or heat-deproteinated bone) may have a rightful place among the osteointegrators.

Effect of omega-conotoxin and verapamil on antinociceptive, behavioural and thermoregulatory responses to opioids in the rat.

This study with the rat evaluated the contribution of omega-conotoxin GVIA-(omega-CgTx) and verapamil-sensitive Ca2+ channels in behavioural, antinociceptive and thermoregulatory responses to intracerebroventricular (i.c.v.) injection of [D-Ala2,NMePhe4,Gly-ol5]enkephalin (DAMGO), [D-Pen2,D-Pen5]enkephalin (DPDPE) and dynorphin A-(1-17), which are selective agonists for putative mu, delta and kappa-opioid receptors, respectively. The rats treated with omega-CgTx (8-32 pmol i.c.v.) showed transient, dose-dependent shaking behaviour, hyperalgesia and hypothermia which gradually disappeared within 4 h. The behaviour of the rats was normal by 24 h. Histological examination of brain sections showed morphological alterations of neurons in the hippocampus, medial-basal hypothalamus and pyriform cortex. antinociception, catalepsy and thermoregulatory responses elicited by DAMGO (0.4 and 2.0 nmol) were significantly prolonged and potentiated by verapamil (20 pmol i.c.v. 15 min before) or omega-CgTx (8 pmol 24 h before). Antinociception and hypothermia induced by DPDPE were antagonized by verapamil and omega-CgTx, whereas only omega-CgTx prevented the behavioural arousal observed after DPDPE. Similarly, hypothermia induced by dynorphin A-(1-17) (5.0 nmol) and by the kappa-opioid receptor agonist U50,488H (215 nmol) was antagonized by the two Ca2+ channel blockers but only omega-CgTx prevented the barrel rolling and bizarre postures caused by the opioid peptide.

Pulsed electromagnetic field stimulation on posterior spinal fusions: a histological study in rats.

This study reports the histological data relative to the effect of pulsed electromagnetic fields (PEMFs) on the evolution of posterior arthrodesis induced in the lumbar vertebrae of 12 adult male Sprague-Dawley rats. After the operation, one group of six rats was stimulated with PEMFs for 18 h per day, by means of a pair of coils fixed to the outside of the cage. A control group of six rats was given no stimulation after surgery. In the groups stimulated with PEMFs an acceleration of the process of bone callus organization was already observed after 4 weeks, and even more so after 8: An early replacement was in fact observed of the newly formed cartilage tissue with primary bone (at 4 weeks) and subsequently with secondary bone (after 8 weeks).

[The development of the vertebral articulations in the fetal period]. / Lo sviluppo delle articolazioni vertebrali nel periodo fetale.

In this paper the thoracic tract of fetal rachis aging between 9 and 19 weeks has been investigated. The study has been carried out with histological and radiological techniques. The histological examination of these samples reveals that the articular processes are completely formed at week 12, in this period it is also evident a primitive joints between the articular processes. Nevertheless the joint is completely formed only at week 19, when the fibrous capsula and the synovial cavity are well formed. These data are confirmed by the sectional radiography.

Human Achilles tendon: morphological and morphometric variations as a function of age.

Aging of human Achilles tendon results in changes in both cellular and fibrous components. Cells flatten and become less numerous. Their thin and long cytoplasmatic projections tend to shorten and diminish in number. Tendon fibers lose their typical undulating appearance and become quite straight. Collagen fibril diameter, small and uniform in the neonatal period, becomes large and extremely variable from adolescence onwards. Age related morphometric changes include a decrease in the average, maximum diameter and density of collagen fibrils and an increase of fibril concentration. In our opinion these morphological and morphometric variations are strictly related to functional requirements.