Biomedical subjects

R Ruffoli

Publications and source records attributed to R Ruffoli.

At least 19 recordsLinked to original sources

PubMed2006

Diazepam administration prevents testosterone decrease and lipofuscin accumulation in testis of mouse exposed to chronic noise stress.

Lipofuscin is an autofluorescent and undegradable material, which accumulates in tissues during ageing and under different types of stress. Among these, oxidative stress represents a major trigger for lipofuscin formation. However, prolonged noise exposure is also an effective stressful stimuli. Diazepam may inhibit lipofuscinogenesis in liver and prevent the noise-induced reduction of the steroidogenesis in the adrenal gland. The aim of the study was to ascertain whether chronic noise exposure causes lipofuscin accumulation in mouse testis, and to evaluate the effects of diazepam administration. Eight-week old mice were either exposed for 6 weeks (6 h day(-1)) to white-noise (group A), or received diazepam (3 mg kg(-1), i.p.) before noise exposures (group B), while a further group was used as control (group C). Light fluorescence and transmission electron microscopy revealed lipofuscin in large amounts in the Leydig cells in mice of group A, which concomitantly had low serum testosterone levels; pre-treatment with diazepam occluded both effects. The present study indicates that: (i) chronic noise exposure causes lipofuscin accumulation at the level of the Leydig cells and a decrease in testosterone; (ii) all these effects are suppressed by pre-treatment with diazepam. As the Leydig cells represent the only cellular type of the interstitial testicular tissue having peripheral benzodiazepine receptors, these results could be explained by the capacity of the peripheral benzodiazepine receptors to prevent reactive oxygen species damage and to increase the resistance of these cells to oxidative stress.

Animals↗

PubMed2005

Inflammatory mediators and eosinophilia in atopic and non-atopic patients with nasal polyposis.

Nasal polyps are characterized by eosinophilic infiltration and presence of inflammatory mediators, such as total IgE, eosinophil cationic protein (ECP) and cytokines. The role of atopy in nasal polyp pathogenesis is still unclear. Therefore, we evaluated serum IgE levels, nasal mucus concentrations of ECP and cytokines and the number of infiltrating eosinophils in nasal tissue of polyps from atopic and non-atopic patients. Samples were obtained from a randomized population of 31 patients with nasal polyposis having endonasal sinus surgery and of 13 control subjects undergone corrective surgery of the nasal septum. On the basis of medical history of allergy, positive skin-prick tests and total IgE levels, patients with polyposis were divided in atopic (n = 13) and non-atopic (n = 18) patients. We determined levels of IgE in blood, ECP and cytokines (IL-4, IL-6, IL-8, IFN-gamma and IL-2) in nasal mucus, and number of infiltrating eosinophils in nasal tissue. The concentrations of total IgE, ECP, IL-4 and IL-8 and eosinophilia were significantly higher in all patients with nasal polyps compared with controls. Inside, all patients with nasal polyposis showed lower levels of IL-6, IFN-gamma and IL-2 compared with controls. The atopic patients showed significant differences when compared with non-atopic patients for the higher concentrations of total IgE (698.80+/-322.24 vs. 279.63+/-234.11; P < 0.0001) and IL-8 (1437.2 pg/ml+/-1250.7 vs. 605.5 pg/ml+/-481.1; P < 0.015). These findings suggest that inflammation still remains the major factor in the etiology of nasal polyposis and show different levels of inflammatory mediators into atopic and non-atopic patients.

Adult↗

PubMed2005

Ankyloglossia: a morphofunctional investigation in children.

OBJECTIVES: To provide diagnostic criteria for ankyloglossia in children by anatomical measurements; to investigate the correlation between severity of ankyloglossia and a series of morphofunctional findings; to evaluate the potential mismatch between a clinical suspect of ankyloglossia and the authentic anatomical diagnosis. DESIGN: Two different techniques of anatomical measurements and a clinical evaluation of a series of morphofunctional findings were performed. SUBJECTS AND METHODS: In 200 children referred for evaluation and treatment of tongue-tie, the length of the frenulum and the interincisal distance were measured in maximum opening of the mouth and with the tip of the tongue touching the palatal papilla. Occlusion, type of bite, tongue resting position, swallowing mechanism, oral floor mobility, frenulum insertion modality and speech were investigated. Any correlation between these morphofunctional findings and anatomical measures was investigated. RESULTS: Children with a frenulum length more than 2 cm and an interincisal distance of more than 2.3 cm were normal. In both measurements, significant correlations among mean values and other variables were observed. Moreover, three levels -- mild, moderate and severe -- of ankyloglossia were assessed. CONCLUSIONS: Length of frenulum and interincisal distance allow an assessment of severity of ankyloglossia in children. Ankyloglossia was not associated with infantile swallowing.

Anthropometry↗

PubMed2004

Distribution of 3-nitrotyrosine in the nasal polyps of atopic patients.

OBJECTIVE: To investigate whether formation of nitrotyrosine in the nasal polyps of atopic patients occurs. STUDY DESIGN: A nonrandomized, retrospective, controlled qualitative and quantitative study. METHODS: Nasal polyp tissue samples were acquired from 12 atopic patients. Control fragments of nasal mucosa were taken from 10 patients undergoing corrective surgery of the nasal septum. For routine histologic examinations, hematoxylin-eosin staining was used. Low-magnification microscopy was designed to yield pathologic characteristics and high magnification to quantify the number of eosinophils in the subepithelial connective tissue. Presence of nitrotyrosine was assessed by immunohistochemical method. RESULTS: Hematoxylin-eosin staining revealed presence of numerous eosinophils in the epithelium and in the subepithelial connective tissue. All polyps were characterized by epithelial damage. Nitrotyrosine was present in the eosinophils, in the ciliated cell, and in cells of the damaged epithelium. Goblet cells, glands, and vessels were found to be negative. No significant differences concerning the localization of nitrotyrosine were recognized among the examined nasal polyps. CONCLUSIONS: Nitrotyrosine immunohistochemical staining in nasal-polyp tissues suggested the existence of progressive epithelium injury caused by peroxynitrite. Consequences of peroxynitrite formation in eosinophils remain to be precisely established. The lack of nitrotyrosine in glands and blood vessels indicated that peroxynitrite does not have a significant role in the vascular and glandular dysfunction of nasal polyps.

Adult↗

PubMed2003

Cytokine secretion in nasal mucus of normal subjects and patients with allergic rhinitis.

Allergic rhinitis is regulated by the local production and release of several cytokines. The levels of Th2 cytokines IL-4, IL-6, IL-10 and the Th1 cytokine IFN-gamma were studied in nasal mucus from 30 subjects with allergic rhinitis and 45 non-atopic healthy controls. In this study a sampling technique for collecting nasal mucus, well tolerated by the subjects and with a minimal stimulation of the mucosa, was performed. The cytokine concentrations in nasal mucus samples were detected and quantitated by a new paramagnetic particle-based immunofluorescent assay system more sensitive than the conventional ELISA techniques. The new technique showed reliable values of the measured parameters. The nasal mucus from allergic patients contained significantly higher concentrations of IL-4 (25.5 +/- 3.6 pg/ml; P < 0.001) and IL-10 (1300 +/- 190 pg/ml; P < 0.05) compared to the nasal mucus from control subjects (15.2 +/- 2.3 and 532 +/- 28 pg/ml, respectively, for IL-4 and IL-10). No significant modification in IFN-gamma levels of allergic patients was found when compared to control group (respectively, 19.9 +/- 3.3 vs. 25.7 +/- 5.1 pg/ml; P > 0.05). Moreover, the allergic patients showed lower levels of IL-6 concentrations in the nasal mucus compared to control subjects (64.8 +/- 9.1 vs. 129.0 +/- 18.1 pg/ml; P = 0.0099). These data can be interpreted by the hypothesis that in response to environmental allergens there is a preferential Th2 polarity by activated CD4+ T cells and that the cytokines IL-6 and IL-10 have, respectively, an important anti-inflammatory and counterregulatory action in the pathogenesis of allergic rhinitis.

Adolescent↗

PubMed2002

Noradrenergic loss enhances MDMA toxicity and induces ubiquitin-positive striatal whorls.

Movement disorders involve a number of neurodegenerative conditions, mostly affecting basal ganglia. Parkinson's disease (PD) is classically defined by the selective loss of dopaminergic neurons in the substantia nigra pars compacta. Administration of specific neurotoxins represents a common tool to reproduce this lesion. Among these, amphetamine derivatives act as powerful monoamine neurotoxins, impairing striatal dopamine (DA) axons in mice. Despite the well-investigated effects on striatal DA terminals, only sporadic studies have focused on the potential toxicity of amphetamines towards post-synaptic neurons within the striatum. In the present work we found that 3,4-methylenedioxymethamphetamine (MDMA) produces ultrastructural alterations in striatal cells, featuring as membraneous whorls, positive for ubiquitin and heat shock protein 70. These morphological alterations were enhanced in locus coeruleus-lesioned mice.

Adrenergic Uptake Inhibitors↗

PubMed2001

Ultrastructural localization of the NADPH-diaphorase activity in the Leydig cells of aging mice.

Recently, it has been shown that nitric oxide may inhibit the Leydig cell steroidogenesis. The present paper describes, by means of NADPH-diaphorase histochemistry, the ultrastructural localization of the enzyme nitric oxide synthase in the Leydig cells of young adult and aging mice. In the young adult mice, the enzymatic reaction was mainly located in the mitochondria and in some clustered cisternae of the smooth endoplasmic reticulum. The nuclear envelope was faintly labeled. In the aging mice, most Leydig cells showed an enhanced enzymatic reaction. Labeled mitochondria were increased in number, and labeled areas of the smooth endoplasmic reticulum were more numerous and extended. In addition, a strong enzymatic reaction was recognized in the nuclear envelope. We conjecture that the impaired steroidogenesis observed in the testis of aging mammals might, at least in part, depend on the increased nitric oxide production in the Leydig cells.

Aging↗

PubMed2001

Novel aspects of dopamine oxidative metabolism (confounding outcomes take place of certainties).

Abstract: Understanding dopamine (DA) oxidative metabolism allows to get a deeper insight into neurologic and psychiatric disorders featured by an altered DA neurotransmission as well as developing appropriate therapeutic strategies. Oxidative DA deamination is carried out by two highly conserved isoenzymes: monoamine oxidase (MAO) A and B; these isoenzymes both metabolize DA to dihydroxyphenylacetaldehyde (DOPALD), which, in turn, is converted to dihydroxyphenylacetic acid (DOPAC). In the past twenty years most studies on MAO activity were performed using brain dialysis in freely moving rats and measuring DA and DOPAC levels after administration of specific MAO inhibitors. This led to concepts on DA metabolism grounded on a single brain area (striatum) investigated, almost exclusively, in a single animal species (rat). These experiments were based on measurement of striatal levels of DOPAC which represents the indirect product of MAO activity. At present, the specific role of each MAO isoform appears to differ significantly depending on varying experimental conditions such as measuring the direct product of DA metabolism. In particular, recent studies allowed the estimate of the first metabolite (DOPALD) formed by MAO, showing that DOPAC levels do not necessarily reflect MAO activity. Again, the relative contribution of the two MAO iso forms in sustaining DA metabolism varies considerably, depending on the animal species and the specific brain area (either striatum or substantia nigra) under investigation. In this article we will briefly review these concepts in light of new evidence derived from innovative approaches: improved in vivo analysis of direct MAO metabolic products; measurement of oxidative metabolism in different parts of the DA nigrostriatal pathway; measurement of MAO activity in various animal species including MAO knock-out mice.

3,4-Dihydroxyphenylacetic Acid↗

PubMed2000

Ultracytochemical localization of the NADPH-d activity in the human nasal respiratory mucosa in vasomotor rhinitis.

OBJECTIVES: Description of the ultrastructural localization of nitric oxide synthase in the blood vessels of the nasal respiratory mucosa in patients with vasomotor rhinitis. STUDY DESIGN: This research was conducted on seven patients--men and women, ages 20 to 45 years--suffering from vasomotor rhinitis and who had undergone surgical therapy for reduction of the inferior turbinates. METHODS: To study the ultrastructural localization of nitric oxide synthase, NADPH-diaphorase cytochemistry was employed. Samples of the nasal mucosa were obtained from inferior turbinates. RESULTS: The endothelial cells of the arterioles, capillaries, venules and cavernous sinuses revealed a distribution of the enzymatic activity similar to that found in unaffected subjects. A strong enzymatic activity was recognized in the smooth muscle cells of the cavernous sinuses. The smooth muscle cells of arterioles and venules were generally found to be negative to enzymatic reaction. CONCLUSIONS: This study suggests that the vascular disorders of the vasomotor rhinitis depend, at least in part, from nitric oxide synthase induction in the smooth muscle cells of the cavernous sinuses.

Adult↗

PubMed1999

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.

Aging↗

PubMed1998

Ultrastructure of the supporting cells in the paratympanic organ of chicken, Gallus gallus domesticus.

The paratympanic organ is a specialized sensory organ of birds located in the medial wall of the tympanic cavity. It possesses a sensory epithelium formed by type II hair cells and supporting cells. The supporting cells are tall, narrow units that extend from the basement membrane to the free epithelial surface. They show a fine structure characterized by numerous mitochondria, a conspicuous Golgi complex and a well-developed RER. Moreover, some uncommon structures, probably formed by heaped RER cisternae, are frequently present in the cytoplasm. Adjacent supporting cells are connected by numerous and extensive gap junctions; moreover, small gap junctions between hair cell and supporting cells are to be found. The possible mechanical and metabolical functions of the paratympanic organ supporting cells are discussed.

Animals↗

PubMed1998

Cytochemical localisation of the NADPH diaphorase activity in the Leydig cells of the mouse.

The distribution of the NADPH diaphorase activity was studied in mouse Leydig cells by means of light and electron microscopy. When observed by the light microscope, most Leydig cells appeared intensely stained; a few cells (about 10%) showed a slightly positive or apparently negative reaction. The inhibitory effects of N(G)-nitro-L-arginine and iodonium diphenyl on frozen sections suggest the colocalisation of NADPH diaphorase reaction with nitric oxide synthase. The ultrastructural study revealed that all the Leydig cells were positively stained for NADPH diaphorase; however, a small number of cells displayed weak enzymatic activity. The reaction product was located in the mitochondria, smooth endoplasmic reticulum and lipidic vacuoles, and the nuclear envelope was also stained. The possible meaning of the NADPH diaphorase activity in the Leydig cells of mice was discussed.

Animals↗

PubMed1998

The ultrastructural localization of NADPH-diaphorase enzymatic activity in the Leydig cells of mouse. effects of ethanol administration.

The effects of the chronic ethanol treatment on the NOS-related NADPH-diaphorase activity were described in the mouse Leydig cells by means of transmission electron microscope. The recovery of the Leydig cells was also examined during a period of four weeks. About 10% of the Leydig cells showed various degrees of morphological alterations, consisting in increased number of lipid droplets, rarefaction and vacuolization of the cytoplasmic matrix. Other groups of Leydig cells (about 10%) revealed evident signs of degeneration. The NADPH-d activity was reduced both in apparently normal and injured Leydig cells and a moderate enzymatic reaction was only detected in the smooth endoplasmic reticulum. A week after the treatment an increased number of the degenerating Leydig cells and a further reduction of the enzymatic reaction were observed. Then, the Leydig cells showed a progressive recovery and four weeks after the treatment they exhibited a normal morphology and NADPH-d enzymatic reaction. These results demonstrated for the first time the inhibition of NOS activity in the Leydig cells after chronic ethanol administration.

Administration, Oral↗

PubMed1998

Diazepam reduces ultrastructural changes induced by noise stress in rat adrenal gland.

Male rats were exposed to noise for 6 running hours and the effects of pretreatment with the benzodiazepine diazepam on the adrenal gland were evaluated. Ultrastructural examination showed that, after noise exposure, zona reticularis cells resulted the more affected, exhibiting areas of diluted cytoplasm, disarranged endoplasmic reticulum, membrane vestigia and some altered mitochondria; diluted cytoplasmic areas appeared in noradrenaline-storing cells, too. On the contrary, zona reticularis cells from diazepam-pretreated and noise-exposed rats resulted significantly less altered, as well as the noradrenaline-storing cells. The present findings indicate that diazepam is able to exert some protective action on adrenal gland alterations due to noise exposure.

Adrenal Cortex↗

PubMed1996

The ultrastructure of the sensory hairs of the paratympanic organ receptor cells in chicken.

The hair bundle of the receptor cells in the paratympanic organ of the chicken was studied by TEM, after fixation in aldehydes/osmium tetroxide or in aldehydes/osmium tetroxide/tannic acid. The bundles are formed by a kinocilium and by 40-70 stereocilia. The stereocilia are linked to each other by an extensive network of filaments. Three types of these connectors are present: basal, shaft and apical; the latter consist of side-to-side and tip-to-side connectors. We observed that the shaft connectors are well-highlighted only when tannic acid was used, while the other connectors are to be found in the conventionally fixed specimens also. The tip-to-side connector consists of a filament which joins the tip of a stereocilium with the side of an adjacent taller stereocilium; we suggest that the distortion of this filament would give rise to the mechanosensory transduction. The other connectors probably serve to maintain the regular spatial arrangement of the hair bundle and the mechanical coupling of the stereocilia. Our study shows that the general conformation of the hair bundle and the stereociliary links of the hair cells in the paratympanic organ of chicken are similar to those previously described in the hair cells of the acoustico lateralis system.

Animals↗

PubMed1996

Fine structure of the afferent synapses in the paratympanic organ of the chicken, with special reference to the synaptic bodies.

The afferent synapses of the paratympanic organ in the chicken were studied by TEM. These synapses were formed by non-myelinated fibres which reached the basal part of the hair cells. The fibres contained a number of irregular mitochondria and a few pale vesicles. In the hair cells, near the presynaptic membrane, typical synaptic bodies formed by an electron-dense core surrounded by several small pale vesicles were present. The core was connected with the vesicles by numerous thin filaments, and at same time with the presynaptic membrane by some dense projections. Moreover, we have observed that the connections between the core and the adjacent vesicles also consisted of similar structures to the dense projections. We suggest that this device is involved in the movement of the vesicles towards the presynaptic membrane. Our hypothesis is in agreement with that formulated by some authors who believe that the electron-dense core of the synaptic bodies is able to channel the vesicles to the presynaptic membrane (conveyor-belt hypothesis). Moreover, our work showed that the synaptic bodies of the paratympanic organ in the chicken are variable in density and in shape. These morphological aspects might be linked to regression-reconstitution cycles of the SBs and to the functional level of the afferent synapses.

Afferent Pathways↗

PubMed1996

Homing experiments on pigeons subjected to bilateral destruction of the paratympanic organ

The paratympanic organ (PO) in birds is a specialised sensory organ whose function is still unknown. G. Vitali, who first described the PO from observations of the behaviour of PO-lesioned pigeons, proposed that this organ was needed to maintain normal wing muscle function and called it the 'organ of flight'. This interpretation has since been disputed. To solve this controversy and to test whether the PO is involved in flight and navigation, we performed release tests on homing pigeons subjected to bilateral destruction of this organ. No impairment of either flight or navigation was observed in the lesioned pigeons.

Journal Article↗

PubMed1993

Fine structure of the middle ear epithelium in the chicken (Gallus gallus).

The epithelium lining the tympanic cavity of the chicken possesses distinct morphological characteristics. Its ultrastructure was studied using 2 preparative techniques. (1) After fixation in Karnovsky's solution, postfixation in osmium tetroxide and embedding in Epon, the epithelium was observed to contain 2 kinds of cell: secretory and basal. The secretory cells (which we refer to as mixed granulated cells) showed numerous secretory vesicles that varied in appearance, some containing paracrystalline formations. The basal cells, located close to the basement membrane, showed no evidence of secretory activity. (2) Other specimens were immersed in Karnovsky fixative and subsequently in a mixture of glutaraldehyde and tannic acid. They were then osmicated and embedded in polar Epon mix. With this method, the epithelium was seen to be covered by electron-dense material made up of thin intertwined tubules. In addition, the secretory cells contained vesicles with concentrically arranged lamellae; such vesicles resembled the multilamellar bodies of mammalian type II pneumocytes. The hypothesis is advanced that tubules and lamellar vesicles are related to the presence of surfactant substances.

Animals↗