AM404 decreases Fos-immunoreactivity in the spinal cord in a model of inflammatory pain

Cannabinoids, such as anandamide, are involved in pain transmission. We evaluated the effects of AM404 (N-(4-hydroxyphenyl)-5Z,8Z,11Z,14Z-eicosatetraenamide), an anandamide reuptake inhibitor, monitoring the expression of c-fos, a marker of activated neurons and the pain-related behaviours using formalin test. The study was carried out in an experimental model of inflammatory pain made by a single injection of formalin in rat hind paws. Formalin test showed that the antinociceptive effect of AM404 was evident in phase I. We found that Fos-positive neurons in dorsal superficial and deep laminae of the lumbar spinal cord increased in formalin-injected animals and that AM404 significantly reduced Fos induction. Co-administration of cannabinoid CB(1) receptor antagonist (AM251), cannabinoid CB(2) receptor antagonist (AM630) and transient receptor potential vanilloid type 1 (TRPV-1) antagonist (capsazepine), attenuate the inhibitory effect of AM404 and this effect was higher using cannabinoid CB(2) and vanilloid TRPV-1 receptor antagonists. These results suggest that AM404 could be a useful drug to reduce inflammatory pain in our experimental model and that cannabinoid CB(2) receptor and vanilloid TRPV-1 receptor, and to a lesser extent, the cannabinoid CB(1) receptor are involved.

Atherosclerosis and the protective role played by different proteins in apolipoprotein E-deficient mice

The aim of the present study was to analyze the early events in atherogenesis and the role of pro- or anti-atherosclerotic proteins in the development of atherosclerotic lesions. We used apolipoprotein E-deficient (E(0)) mice that spontaneously develop hypercholesterolemia and atherosclerotic lesions in the aorta in a time-dependent manner. Aortas of mice aged 6, 8, 10 and 12 weeks were examined to determine histopathological changes. In mice aged 8-12 weeks, developing atherosclerotic lesions were present in different regions of the aortas. These lesions protruded into the lumen of the vessel and showed lipid deposits, lipid-filled macrophages and extensive accumulation of collagen and elastic fibers throughout the entire arterial wall. A parallel immunohistochemical study included analysis of three proteins known to be involved in atherosclerosis, i.e. inducible nitric oxide synthase (iNOS, NOS2), vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP2). Increased immunolabelling of iNOS and VEGF accompanied atherosclerosis development in E(0) mice aged 8, 10 and 12 weeks. On the contrary, immunolabelling for MMP2 was negative in E(0) mice aged 10 and 12 weeks. Our results indicate morphological alterations in the Tunica intima and Tunica media of atherosclerotic aortas and possible protective roles for iNOS and VEGF proteins against atherosclerosis development. These data may be relevant for developing therapeutic strategies for atherosclerosis development.

Acute caffeine administration decreased NOS and Bcl2 expression in rat skeletal muscles

Caffeine (Caf) is largely used to delay fatigue, improving physical activity. However, its role remains elusive, and there are no hemodynamic or immunohistochemical data regarding its effects on skeletal muscle. We studied the hemodynamic and NOS expression of Bax/Bcl2 in skeletal muscle after single Caf administration. Thirty-two male rats were divided into six groups: the first was iv-injected with Caf (16mg/kg), the second with Caf+L-NAME, the third with Caf+L-arg, the fourth with Caf+L-NAME+L-arg, fifth with saline. Mean arterial blood pressure (MAP) was monitored for 30', then the animals were killed. The sixth group was injected with Caf and killed after 2h. The quadriceps were isolated and processed by immunohistochemistry. We found that Caf increased MAP temporarily, while Caf+L-NAME increased it for a longer period. In untreated muscle, all NOS isoforms was expressed with different intensity and localisation, and Bcl2 was strongly expressed among the myofibrils. In Caf and Caf+L-NAME treated animals, NOS expression was lost; Bcl2 expression decreased among myofibrils but increased inside the subsarcolemma. The L-arg administration reversed these Caf and L-NAME effects. Two hours after Caf, NOS expression increased. We concluded that improved physical performance could be related to Caf's ability to interfere with the endogenous muscular synthesis of NO.

Progesterone and its derivatives are neuroprotective agents in experimental diabetic neuropathy: a multimodal analysis

One important complication of diabetes is damage to the peripheral nervous system. However, in spite of the number of studies on human and experimental diabetic neuropathy, the current therapeutic arsenal is meagre. Consequently, the search for substances to protect the nervous system from the degenerative effects of diabetes has high priority in biomedical research. Neuroactive steroids might be interesting since they have been recently identified as promising neuroprotective agents in several models of neurodegeneration. We have assessed whether chronic treatment with progesterone (P), dihydroprogesterone (DHP) or tetrahydroprogesterone (THP) had neuroprotective effects against streptozotocin (STZ)-induced diabetic neuropathy at the neurophysiological, functional, biochemical and neuropathological levels. Using gas chromatography coupled to mass-spectrometry, we found that three months of diabetes markedly lowered P plasma levels in male rats, and chronic treatment with P restored them, with protective effects on peripheral nerves. In the model of STZ-induced of diabetic neuropathy, chronic treatment for 1 month with P, or with its derivatives, DHP and THP, counteracted the impairment of nerve conduction velocity (NCV) and thermal threshold, restored skin innervation density, and improved Na(+),K(+)-ATPase activity and mRNA levels of myelin proteins, such as glycoprotein zero and peripheral myelin protein 22, suggesting that these neuroactive steroids, might be useful protective agents in diabetic neuropathy. Interestingly, different receptors seem to be involved in these effects. Thus, while the expression of myelin proteins and Na(+),K(+)-ATPase activity are only stimulated by P and DHP (i.e. two neuroactive steroids interacting with P receptor, PR), NCV, thermal nociceptive threshold and intra-epidermal nerve fiber (IENF) density are also affected by THP, which interacts with GABA-A receptor. Because, a therapeutic approach with specific synthetic receptor ligands could avoid the typical side effects of steroids, future experiments will be devoted to evaluating the role of PR and GABA-A receptor in these protective effects.

Beneficial effects of melatonin in protecting against cyclosporine A-induced cardiotoxicity are receptor mediated

Melatonin, the chief product secreted by pineal gland, is capable of reducing free radical damage by acting directly as a free radical scavenger, and indirectly, by stimulating of antioxidant enzymes. Cyclosporine A (CsA) is the most widely used immunosuppressive drug, but its therapeutic use has several side effects including, i.e. nephrotoxicity and cardiotoxicity. This study was designed to examine the beneficial effects of melatonin in preventing CsA-induced cardiotoxicity. Additionally, we investigated the ability of melatonin to protect the rat heart via melatonin receptor. In one group of Wistar rats, melatonin (1 mg/kg/day i.p.) was administered concurrently with CsA (15 mg/kg/day s.c.) for 21 days. In another group of animals, melatonin was injected with CsA and luzindole, an antagonist of melatonin receptors. Oxidative stress in heart tissue homogenates was estimated using thiobarbituric acid reactive substances (TBARS), reduced glutathione levels and antioxidant enzyme activities including catalase and superoxide dismutase. CsA administration for 21 days produced elevated levels of TBARS, marked depletion of cardiac antioxidant enzymes and caused morphological alterations in myocardial fibers. Melatonin markedly reduced TBARS levels, increased the antioxidant enzyme levels and normalized altered cardiac morphology. The protective effects of melatonin were lost when the animals received the melatonin receptor antagonist. In conclusion our study shows that, (a) melatonin significantly reduces CsA cardiotoxicity, and (b) the reduction in CsA-induced cardiotoxicity was mediated by the binding of melatonin to its membrane receptors.

Role of mast cells in wound healing process after glass-fiber composite implant in rats

Glass-fiber composites are frequently used in dentistry. In order to evaluate their biocompatibility we tested, in an experimental model "in vivo", their tissue response pointing our attention on presence of mast cells (MCs) and fibrotic process. Sprague Dawley rats were used for the experimental design. The fibers were introduced in a subcutaneous pocket along the middle dorsal line between the two scapulas for 7, 14 or 21 days. At the end of the treatments the skins were excised and then processed for Toluidine Blue, to determine the presence of MCs, and Picrosirius Red staining, to evaluate the presence of fibrotic tissue. Our preliminary results showed and increase of both MC number and deposition of collagen type I, which characterized the fibrotic tissue. So, subsequent aims of our study were to evaluate the role played by MCs in tissue fibrosis and to give a possible explanation regarding the mechanisms that were responsible of biological response observed, through the analyses of some proteins, such as metalloproteinase-2 (MMP-2), its inhibitor (TIMP-2) and transforming growth factor-beta (TGF-beta). Our data confirmed the involvement of TGF-beta, released by MCs, in the disruption of the equilibrium between MMP-2 and TIMP-2 that were implicated in the enhancement of fibrosis. In summary, this study demonstrate that this type of materials induced an inflammatory response at the site of implant and help to clarify what type of mechanism and which proteins are involved in this biological response. Nevertheless, more extensive investigations are in progress to better evaluate the inflammatory process.

Chest wall kinematics, respiratory muscle action and dyspnoea during arm vs. leg exercise in humans

AIM

We hypothesize that different patterns of chest wall (CW) kinematics and respiratory muscle coordination contribute to sensation of dyspnoea during unsupported arm exercise (UAE) and leg exercise (LE).

METHODS

In six volunteer healthy subjects, we evaluated the volumes of chest wall (V(cw)) and its compartments, the pulmonary apposed rib cage (V(rc,p)), the diaphragm-abdomen apposed rib cage (V(rc,a)) and the abdomen (V(ab)), by optoelectronic plethysmography. Oesophageal, gastric and trans-diaphragmatic pressures were simultaneously measured. Chest wall relaxation line allowed the measure of peak rib cage inspiratory muscle, expiratory muscle and abdominal muscle pressures. The loop V(rc,p)/V(rc,a) allowed the calculation of rib cage distortion. Dyspnoea was assessed by a modified Borg scale.

RESULTS

There were some differences and similarities between UAE and LE. Unlike LE with UAE: (i) V(cw) and V(rc,p) at end inspiration did not increase, whereas a decrease in V(rc,p) contributed to decreasing CW end expiratory volume; (ii) pressure production of inspiratory rib cage muscles did not significantly increase from quiet breathing. Not unlike LE, the diaphragm limited its inspiratory contribution to ventilation with UAE with no consistent difference in rib cage distortion between UAE and LE. Finally, changes in abdominal muscle pressure, and inspiratory rib cage muscle pressure predicted 62% and 41.4% of the variability in Borg score with UAE and LE, respectively (P < 0.01).

CONCLUSION

Leg exercise and UAE are associated with different patterns of CW kinematics, respiratory muscle coordination, and production of dyspnoea.

Role of carbon monoxide and biliverdin in renal ischemia/reperfusion injury

Heme oxygenase (HO) isoforms catalyze the conversion of heme to carbon monoxide (CO) and biliverdin/bilirubin with a concurrent release of iron. There is strong evidence that HO activity and products play a major role in renoprotection, however the exact molecular mechanisms underlying the beneficial effects exerted by this pathway are not fully understood. This review is aimed at illustrating the possible mechanism/s by which HO is renoprotective in the context of ischemia/reperfusion. We will first analyze the effects of exogenous administration of bilirubin/biliverdin and CO and then describe their biological activities once generated endogenously following stimulation of the HO pathway by either pharmacological means or gene targeting-mediated approaches.

Changes in extracellular matrix in subcutaneous small resistance arteries of patients with primary aldosteronism

CONTEXT AND OBJECTIVE

It has been previously demonstrated that aldosterone may possess a strong profibrotic action in vitro and in animal models of genetic or experimental hypertension. Our aim was to evaluate whether such a profibrotic action is present also in the human microcirculation.

DESIGN AND PATIENTS

We investigated 13 patients with primary aldosteronism, seven patients with essential hypertension, and 10 normotensive controls. All subjects were submitted to a biopsy of gluteal sc fat tissue. Small resistance arteries were dissected and mounted on an isometric myograph, and the tunica media to internal lumen ratio was measured.

MAIN OUTCOME MEASURES

The total collagen content within the tunica media was detected (Sirius red staining and image analysis), and collagen subtypes were evaluated using polarized light microscopy; under this condition thicker type I collagen fibers appear orange or red, whereas thinner type III collagen fibers are yellow or green.

RESULTS

Tunica media to internal lumen ratio was significantly increased in primary aldosteronism and in essential hypertension compared with normotensive controls. Clinic blood pressure values were similar in primary aldosteronism and in essential hypertension, and greater than in normotensive controls. Normotensive controls had less total and type III collagen (3.23 +/- 0.58 and 1.60 +/- 0.22%, respectively) in respect to the two hypertensive groups (P < 0.001). Total collagen and type III vascular collagen were significantly greater in primary aldosteronism (total collagen, 8.17 +/- 1.38%; type III collagen, 6.06 +/- 0.74%; P < 0.05) than in essential hypertension (total collagen, 6.84 +/- 1.15%; type III collagen, 5.25 +/- 0.80%).

CONCLUSIONS

Our results indicate that, in small resistance arteries of patients with primary aldosteronism, a pronounced fibrosis may be detected, even more evident than in blood-pressure-matched patients with essential hypertension.

Bimoclomol ameliorates mercuric chloride nephrotoxicity through recruitment of stress proteins

Bimoclomol (BIM), is a stress proteins coinducer, that acts synergistically with a mild stressor to activate cytoprotective stress proteins. BIM has been successfully utilized in animal models for the treatment of various nervous, cardiac and cerebrovascular diseases. Mercuric chloride (HgCl(2)) induces acute renal failure in rats by a single dosage. The present in vivo study was conducted to assess the efficacy of BIM against acute HgCl(2) nephrotoxicity. At different times after BIM and/or HgCl(2) exposure we evaluated renal morphology and the localization/abundance of three stress proteins (HSP72, GRP75, HSP60) by electron microscopy, immunohistochemistry and Western blot analysis. BIM delivery to rats 6h before mercury, ameliorated damage to renal ultrastructure, with recovery of tubular and mitochondrial membranes 24h after mercury treatment. In rats pretreated with BIM prior to HgCl(2) exposure, HSP72 was significantly overexpressed in proximal tubules in a time-dependent manner. In contrast, the amounts of GRP75 and HSP60 after BIM pretreatment were comparable to the group treated with mercury alone, but these stress proteins had translocated to the nuclei at 14 and 24h, respectively. These novel findings suggest that BIM mitigates HgCl(2) nephrotoxicity in rats through the early recruitment of stress proteins in midcortical proximal tubules that are the main renal mercury-targets.

Tubular stress proteins and nitric oxide synthase expression in rat kidney exposed to mercuric chloride and melatonin

Stress proteins such as HSP70 members (HSP72 and GRP75) and metallothionein (MT) protect the kidney against oxidative damage and harmful metals, whereas inducible nitric oxide synthase (iNOS) regulates tubular functions. A single dose of mercuric chloride (HgCl(2)) can cause acute renal failure in rats, its main target being the proximal tubule. Oxidative damage has been proposed as one of its pathogenic mechanisms. In this study we tested whether melatonin (MEL), a powerful antioxidant compound, is effective against HgCl(2) nephrotoxicity. Rats were treated with saline, HgCl(2) (3.5 mg/kg), MEL (5 mg/kg), and MEL + HgCl(2) and examined after 24 hr for HSP72, GRP75, MT, and iNOS by immunohistochemistry and immunoblotting. Tubular effects of the treatment were then characterized by ultrastructure. In the HgCl(2) group, all markers were overexpressed in convoluted proximal tubules and sometimes in distal tubules. In the MEL + HgCl(2) group, GRP75 and iNOS decreased in convoluted and straight proximal tubules, whereas HSP72 and MT persisted more than the saline and MEL-only groups. Tubular damage and mitochondrial morphometry were improved by MEL pretreatment. In conclusion, the beneficial effect of MEL against HgCl(2) nephrotoxicity was outlined morphologically and by the reduction of the tubular expression of stress proteins and iNOS. These markers could represent sensitive recovery index against mercury damage.

Expression of non-muscle myosin heavy chain in rat heart after immunosuppressive treatment

Myosins constitute a large family of molecular motors, hydrolyzing ATP and producing cellular movement. To date, a large number of novel isoforms have been found in muscle and non-muscle cells. Among non-muscle myosins, non-muscle myosin heavy chain (NMHC) II-A and II-B have been well characterized. An additional member of NMHC II-B, with a molecular weight of 220 kDa, was recently identified in bovine skeletal muscle. NMHC II-B proteins, in particular, have been suggested to be a useful early molecular marker for the detection of pathological conditions during acute or chronic organ rejection in which fibrotic changes occur. Since it is known that treatment with cyclosporine A (CsA), an immunosuppressive drug successfully used for preventing organ rejection and autoimmune diseases, is often associated with several side effects (hypertension and nephrotoxicity), the aims of this study were: (1) to demonstrate the homology of the new NMHC protein (220 kDa) in other mammalian species, such as Wistar rats; (2) to evaluate, by morphological and immunohistochemical studies, the possible changes induced by CsA treatment in NMHC protein (220 kDa) cellular localization and/or in its expression levels in myocardial tissue. First of all, our results showed a greater homology of the new NMHC within the same isoforms across species and between isoforms in the same specie; moreover, we observed that this protein increased following CsA treatment. This could be explained as a tentative of cardiac tissue to maintain the structural integrity of intercalated disks and so the contraction/relaxation process.

Protective Role of Polyphenols in Cyclosporine A-induced Nephrotoxicity During Rat Pregnancy

The aim of this study was to evaluate the adverse effects of cyclosporine A (CsA) toward renal morphogenesis and to test the renoprotective natural antioxidants such as provinol (PV). Pregnant rats were divided into four groups. Group I was injected SC with olive oil. Group II was treated with oral administration of PV and was used as control. Group III animals were injected SC daily with CsA, and group IV animals were injected daily with CsA and PV for 21 days of pregnancy. Five pups per litter were killed and the kidneys removed and treated by morphological and immunohistochemical (IHC) methods. IHC analysis considered two proteins responsible for nephrotoxicity in adult rats: inducible nitric oxide (iNOS) and matrix metalloproteinase-2 (MMP2). Pregnancy outcomes among CsA-treated rats demonstrated a reduced number of pups. Pups that were exposed antenatally to CsA presented several pathologic findings in all immature parenchyma and an increase in iNOS and MMP2 expression. These side effects were not observed in kidney of litters born from CsA + PV-treated mothers. Our study indicates that CsA induces morphological alterations in renal parenchyma of neonates and that PV plays a protective role against these side effects.

Breathing pattern and kinematics in normal subjects during speech, singing and loud whispering

AIMS

We used for the first time a non-invasive optoelectronic plethysmography to assess breathing movements and to provide a quantitative description of chest wall kinematics during phonation.

METHODS

Volumes of different chest wall compartments (abdomen and lung apposed to rib cage and abdomen) were assessed using optoelectronic plethysmography in 16 normal Italians (eight men) during reading, singing and high-effort whispering (HW).

RESULTS

During phonation the breathing pattern was different from quiet breathing and exercise. (1) During phonation, tidal volume and expiratory time increased while inspiratory time decreased. The expiratory volume changes and flows during HW were considerably greater than during vocalization. During HW, the overall end-expiratory thoracic volume significantly decreased as a result of decreased volume of all compartments and essentially impinged on the maximal expiratory flow-volume curve. (2) While, as previously shown, during exercise the expired volume is due entirely to the abdomen, during phonation all three chest wall compartments contribute to it. Under all conditions studied breathing was, on average, more costal in females than in males but this was mainly related to different size rather than gender per se.

CONCLUSIONS

Physical characteristics have a greater importance than gender in determining breathing pattern and chest wall kinematics during phonation. The activity of the control of expiration during phonation is more complex than during exercise.

Stress proteins expression in rat kidney and liver chronically exposed to aluminium sulphate

Aluminium (Al) is the third most widespread metal in the environment. It is toxic for the brain, bone and haematological system but unfortunately very little data exist for other organs. Stress proteins are induced or enhanced against metal toxicity with an essential role in the recovery of organules and other cellular proteins. This immunohistochemical study was performed to analyze the distribution of three stress proteins (HSP25, HSP72, GRP75) in rat kidney and liver orally exposed to Al sulphate daily for 3 and 6 months. Al-induced alterations were further studied by histopathology (H-E, PAS, Perl's, Masson) and ultrastructural morphometry. In the kidney: HSP25 was enhanced in proximal tubules after 6 months Al-exposure when abnormal brush borders were observed; HSP72 was induced in proximal tubules only after long Al-treatment; GRP75 was raised in midcortical area sometimes within nuclei. Furthermore, lysosomal and lipofuscins densities increased in the juxtamedullary tubules after 3 months Al exposure with respect to controls. In the liver: Perl's-positive deposits and fibrosis became evident after Al treatment. HSP25 was very weak; HSP72 focal in pericentral hepatocytes at 3 months and induced also in Kupffer cells at 6 months; GRP75 diffuse in periportal hepatocytes and non parenchymal cells at 6 months. Prolonged Al exposure stimulated stress proteins strictly organ-dependently in the rat. Their distribution in kidney and liver seems related to cumulative sublethal effects induced by metal and could be a sensitive index of Al susceptibility of these organs.

Exposure to aluminium changes the NADPH-diaphorase/ NPY pattern in the rat cerebral cortex

Aluminium (Al) impairs the glutamate-nitric oxide-cGMP pathway and reduces the number of nitroxidergic neurons in the rat somatosensory cortex. To understand better the effect of the time of exposure, we monitored the effect of aluminium administration on nitroxidergic neurons, identified by NADPH-diaphorase (NADPH-d) or by nitric oxide synthase (NOS) staining, after 0.5, 1, 2, 3, 6 and 12 months of aluminium administration. Since neuropeptide Y (NPY) is known to be colocalised with nitric oxide synthase in cortical neurons, the aim of this work was to study the effects of Al administration on the cortical expression of NADPH-d, nNOS, and NPY. NADPH-d or NOS positive neurons were found scattered in the cortex where they constituted about 1% of all neurons. Double staining using NADPH-d and NPY showed that almost all nitroxidergic neurons were co-localised with NPY neurons (NADPH-d/NPY double stained neurons) whereas some neurons were stained only with NPY (NPY single stained neurons) ; these were more numerous than NADPH-d/NPY double stained neurons. Al significantly reduced NADPH-d and nNOS positive neurons in the cerebral cortex time dependently, with the greatest effect appearing after 3 months. Also measured was the integrated optical density (IOD) of nNOS positive neurons showing a significant decrease of NOS immunostaining even in the remaining NOS positive neurons. The double staining experiment exhibited a decrease in NADPH-d/NPY double stained neurons with an apparent increase in NPY single stained neurons; these then decreased after 6-12 months. On the whole, the results confirm that Al impairs nitroxidergic pathways time dependently; moreover, the transient increase in NPY single stained neurons from 1 to 3 months suggests that there is an intraneuronal down-regulation of NOS, without affecting neuronal viability. In addition, the decrease in the NPY system found at 6 and 12 months may indicate that Al affected nitroxidergic and NPY systems at different times.

Protective role of melatonin in cyclosporine A-induced oxidative stress in rat liver

Cyclosporine A (CsA) is the most widely used immunosuppressive drug for preventing graft rejection and autoimmune disease. However, the therapeutic treatment induces several side effects such as nephrotoxicity, cardiotoxicity, hypertension and hepatotoxicity. Among possible mechanisms of CsA-induced hepatic damage, oxidative stress has been suggested. Melatonin (Mel) has been successfully used as a potent antioxidant against many pathophysiological states. This experimental study was performed to test, during CsA treatment, the alterations of some heat shock proteins (HSP) and the Mel antioxidant properties against CsA-induced injury. Rats were divided into four groups, which were treated respectively with olive oil, Mel alone, CsA and CsA plus Mel for 30 days. At the end of the treatments, the animals were killed and hepatic tissue was treated for morphological (haematoxylin-eosin), biochemical (reduced glutathione, GSH and malondialdehyde, MDA) and immunohistochemical (HSP60, HSP72, GRP75 and MT) analyses. The results indicate that CsA-induced hepatotoxicity was characterised by morphological alterations in tissue architecture, changes in GSH and MDA levels and increase in stress protein expression. In conclusion, our data suggest that the imbalance between production of free oxygen radicals and antioxidant defence systems, due to CsA administration, is a mechanism responsible for oxidative stress. Moreover, we show that Mel plays a protective action against CsA-induced oxidative stress, as supported by biochemical and immunohistochemical results.

Histochemical and immunohistochemical evaluation of gingival collagen and metalloproteinases in peri-implantitis

The extra-cellular matrix of the gingival tissue plays an important role in the homeostasis of dental implants. In this work we have studied immunohistochemically the distribution of collagen I-III-IV-V, tenascin, metalloproteinases (MMP) 1-3-8-13 and TIMP-1 in three groups of patients: (1) subjects with natural teeth (healthy periodontal tissue), (2) subjects with normal peri-implant mucosa and (3) subjects with clinically evident peri-implantitis. The immunolabelling for collagen I-III-IV showed a similar pattern in all three groups. The labelling for collagen V increased in lamina propria of healthy peri-implant tissue and peri-implantitis. Tenascin immunolabelling in healthy and peri-implant tissues was scattered in lamina propria. In peri-implantitis tenascin immunolabelling increased mainly near to the basal lamina. The MMP-1-3-8 and TIMP-1 immunolabelling were very faint and localized in the stroma in all three groups. In healthy and peri-implant tissues MMP-13 immunolabelling was found in the lamina propria whereas in peri-implantitis MMP-13 immunolabelling was also in epithelium. On the whole, these data suggest that in the extracellular matrix of peri-implantitis there are alterations of collagen V, tenascin and MMP-13 patterns.

The protective effect of caffeic acid phenethyl ester against cyclosporine A-induced cardiotoxicity in rats

Cyclosporine A (CsA) is the immunosuppressor, which is most frequently used in transplant surgery and in the treatment of autoimmune diseases. Oxidative stress has been considered as one of the possible mechanisms of CsA-induced cardiotoxicity. The present investigation examines the ability of caffeic acid phenethyl ester (CAPE), which is an active component of propolis extracts, as a natural antioxidant to protect against CsA-induced oxidative stress and cardiotoxicity. CsA cardiotoxicity was induced by subcutaneous injection of CsA at a dose of 15 mg/kg/body weight daily for 21 days in rats. Cardiotoxicity was evaluated by morphological and biochemical studies. CsA treated rats showed degenerative changes with cardiac fibrosis localized around the fibers. These latters were disorganised and the network was disappeared. The ROS production was increased whereas cytochrome-c-oxidase decreased. The expression and levels of matrix metalloproteinase 2 (MMP2) were increased whereas those of its inhibitor were downregulated. CAPE subcutaneous administration (15 micromol/kg/day) improved cardiac cytoarchitecture, decreased the levels and the expression of MMP2, and increased those of TIMP2 proteins. Moreover, it increased cytochrome-c-oxidase activity and decreased ROS production. These results suggest that CAPE could have protective effect against CsA-induced cardiotoxicity.