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Biomedical subjects

R Leonardi

Publications and source records attributed to R Leonardi.

At least 19 recordsLinked to original sources
PubMed2003

Expression of vascular endothelial growth factor in human dysfunctional temporomandibular joint discs.

A high density of blood vessels is found in specimens of temporomandibular joint (TMJ) disc at any stage of internal derangement of the joint, but the factors responsible for angiogenesis in the disc have not been described. The purpose here was to investigate, in human TMJ discs, the expression of vascular endothelial growth factor (VEGF), a multifunctional cytokine that contributes to angiogenesis. Specimens, free of significant morphological alterations and with varying degrees of disc tissue degeneration/regeneration, were studied by immunohistochemistry for VEGF in order to correlate immunohistochemical with histopathological findings. In normal discs and discs with minor pathological changes, fibroblast-like cells, fibrochondrocytes and chondrocyte-like cells were either not or only weakly immunostained by VEGF antibody. In disc specimens from internal derangement of the TMJ with significant tissue degeneration/regeneration, VEGF was consistently expressed. In these specimens, immunoreaction products for VEGF were observed both in the disc and in the endothelial cells of newly formed vessels. This VEGF immunolocalization is consistent with the stimulation of angiogenesis and the morphogenesis and differentiation of chondrocytes. Therefore VEGF expression by disc chondrocyte-like cells might reflect the action of the cytokine as an inducer of angiogenesis and as an autocrine signal for cells of the chondrogenic lineage.

Adult↗
PubMed2003

Detection of vascular endothelial growth factor/ vascular permeability factor in periapical lesions.

Vascular endothelial growth factor (VEGF), also known as vascular permeability factor (VPF), is a multifunctional cytokine. It is overexpressed in several conditions, which are characterized by vascular hyperpermeability and angiogenesis. In this investigation, we have evaluated the possibility that VEGF/VPF could be expressed in periapical lesions. We studied 17 periapical granulomas and 6 periapical cysts by immunohistochemistry. An immunopositive reaction for VEGF/VPF was observed in all 23 periapical lesions; however, the intensity of immunostaining by anti-VEGF antibody varied according to histopathological findings. In periapical granulomas without epithelium, almost all of the inflammatory cells were immunoreactive to anti-VEGF/VIP antibody. In periapical granulomas, which had rests of Malassez in them, some inflammatory cells were stained. On the other hand, epithelial cells always were stained by VEGF/VPF antibody, both in periapical lesions with epithelium and in radicular cysts. This study demonstrated that periapical lesions express VEGF/VPF, although with some differences in cell immunolabeling, which correlated to the lesions' stages of development. Initially, VEGF/VPF would assure angiogenesis and vascular hyperpermeability, resulting in accumulation of inflammatory cells, later it could be involved in cyst fluid accumulation. We hypothesize, therefore, that VEGF/VPF expression plays an important role in the pathogenesis of periapical granulomas and enlargement of radicular cysts by several mechanisms.

Antibodies↗
PubMed2002

Immunolocalization of vimentin and alpha-smooth muscle actin in dysfunctional human temporomandibular joint disc samples.

The expression of vimentin and alpha-smooth muscle (alpha-SM) actin was examined in 10 human temporomandibular joint (TMJ) disc samples, with internal derangement and in two control specimens, in order to evaluate the phenotypic characteristics of TMJ disc cells in relationship to histological findings. This was accomplished by means of monoclonal antibodies specific for vimentin and alpha-SM actin and immunocytochemical technique. The study, revealed that every disc cell constantly expressed vimentin. Scattered alpha-SM actin positive cells could be appreciated in normal TMJ discs and tissues with minor pathological findings. In TMJ discs with severe alterations, i.e. tears and clefts, almost fibroblast-like cells, fibrochondrocytes and chondrocyte-like cells were strongly immunolabelled by anti-alpha-SM actin antibody. According to these findings it can be assumed that vimentin is expressed by all disc cell populations and it appears not to be influenced by any disease condition of the disc; on the other hand the up-regulation alpha-SM actin immunolabelling seems to be correlated to histopathological findings of tears and clefts. Cells, with a contractile phenotype, close to such defects, could be involved in disc tissue contraction and repair. The plasticity of disc cell populations which evolve towards a different phenotype when subjected to action of macro- and micro-environmental factors is also supported.

Actins↗
PubMed2001

Bilateral hyperplasia of the mandibular coronoid processes associated with the nevoid basal cell carcinoma syndrome in an Italian boy.

In this report we present a subject affected by nevoid basal cell carcinoma syndrome (NBCCS), showing also bilateral mandibular coronoid processes hyperplasia, a hitherto unreported association. Our observation of bilateral hyperplasia of the mandibular coronoid processes in a boy with NBCCS may prompt a retrospective and prospective review of other patients affected by this syndrome in order to establish if this anomaly is part of it.

Adolescent↗
PubMed2001

Histochemical study of the elastic fibers in pathologic human temporomandibular joint discs.

PURPOSE: This study investigated histochemically the elastic fibers in human temporomandibular joint (TMJ) discs with varying degrees of tissue degeneration/regeneration to determine whether there are differences that correlate with the histologic findings. MATERIALS AND METHODS: Ten diseased human TMJ discs and 2 control specimens were studied histochemically by staining with Weigert's resorcin-fuchsin after oxidation with peracetic acid. This technique selectively stains elastic, elaunin, (pre-elastic), and oxytalan fibers. RESULTS: In TMJ discs with an abnormal collagen fiber arrangement, an increased number of oxytalan fibers could be observed, contrary to discs with scar-like tissue transformation in which oxytalan fibers were decreased in number. In discs showing tears and clefts, the oxytalan fibers run perpendicular to the defects, whereas elaunin and elastic fibers were mainly circumferentially arranged. In discs with chondroid metaplasia, elastic, elaunin, and oxytalan fibers were extensively detected. CONCLUSIONS: It is hypothesized that the elastic, elaunin, and oxytalan fibers found in severely damaged discs appear to ensure biomechanical compliance by reinforcing regions devoid of collagen bundles and thus function as shock absorbers of stretch and compression.

Adult↗
PubMed2001

Heat shock protein 27 expression in the epithelium of periapical lesions.

Heat shock protein (HSP) 27 is a member of the small HSP family that plays a part in the regulation of epithelial cell growth and differentiation, wound healing, apoptosis and cell protection against inflammatory cytotoxicity mediators. Thus the expression of HSP27 was investigated immunohistochemically in periapical granulomas with epithelial rests of Malassez and in radicular cysts. Anti-HSP27 mouse monoclonal antibody and peroxidase-labeled streptavidin-biotin standard technique were used to study the expression of HSP27. Proliferating epithelial cell rests, and islands of epithelium and epithelial lining of microcysts strongly reacted throughout all layers, whereas radicular cysts epithelial lining presented mainly a moderate suprabasal staining pattern. However both the proliferating epithelial cell rests and the radicular cysts shared an over-expression of HSP27 immunostaining intensity in coincidence with the presence of local infiltration of immune cells. HSP27 may play several roles in periapical lesions that include contributing to the migration of epithelial cell rests and an increased resistance both to necrotic and apoptotic cell deaths.

Antibodies, Monoclonal↗
PubMed2001

[Aneurysms of the common trunk, anterior descending and right coronary artery in a 33 years old man with acute myocardial infarction. A case report].

Coronary artery aneurysms are often incidental findings during coronary angiography; they are mostly secondary to atherosclerosis or vasculitis, they are rarely congenital. Right coronary circumflex and anterior descending arteries are usually involved but only few cases of aneurysms of left main coronary artery are reported. A case of coronary artery aneurysms is described involving left main, right and anterior descending coronary arteries, probably secondary to atypical Kawasaki disease in a 33 years old man with acute myocardial infarction.

Adult↗
PubMed2000

Cellular S-100 protein immunostaining in human dysfunctional temporomandibular joint discs.

S-100 protein was detected immunohistochemically in diseased human temporomandibular joint discs with different degrees of pathology, and the findings compared with those of normal discs. In normal discs, large nerve trunks in the posterior ligament were strongly stained by anti-S-100 antiserum; the very few chondrocyte-like cells sometimes showed faint staining, while no staining was observed in any fibrochondrocyte-like or fibroblast-like cell. In dysfunctional discs, S-100 protein immunostaining seemed to correlate with structural pathological findings. The discs showing an abnormal collagen arrangement or fragmentation of collagen fibres presented overall the same immunolabelling pattern as normal discs. In discs with fibrocartilaginous metaplasia and dystrophic cartilage formation, fibrochondrocyte cells showed a very strong immunoreaction for S-100 protein and fibroblast-like cells in some instances were also positive. These findings suggest that S-100 upregulation in disc cells can be considered an attempt at tissue repair by chondroid metaplasia following an injury in that it enables fibroblast-like cells and fibrochondrocytes to acquire a chondrogenic phenotype.

Adult↗
PubMed2000

Immunolocalization of CD44 adhesion molecules in human periradicular lesions.

OBJECTIVE: The hyaluronate receptor CD44 is a cell surface protein that is involved in several functions. To elucidate whether CD44 plays a role in periapical lesions, an immunohistochemical technique was used to study its distribution. STUDY DESIGN: Twenty periapical lesions-16 periapical granulomas and 4 radicular cysts-constituted the sample. Formalin-fixed/paraffin-embedded tissue sections were studied by means of immunohistochemistry for the presence of the standard CD44H form and its V3 splicing variant. RESULTS: Immunohistochemical staining for CD44H and CD44V3 was observed on epithelial, endothelial, and connective tissue cells. The cells of the fibrous lining around each granuloma were positive, showing an immune reactive pattern directly correlated with the dimension of the lesion. Epithelial rests of Malassez were strongly positive; the reaction product was also evident in the epithelial lining of the cysts. Blood vessels, mainly observed around the lesion, were immunoreactive for CD44. CONCLUSIONS: Our findings demonstrate that CD44H and its V3 variant are expressed in at least 3 different tissue types of periapical lesions. These glycoproteins may be involved in different steps of periapical lesion pathogenesis and evolution.

Chronic Disease↗
PubMed2000

CD44 standard form (CD44H) expression and distribution in dysfunctional human temporomandibular joint discs.

The expression pattern of the cell adhesion molecule CD44 standard form (CD44H) in dysfunctional human temporomandibular joint (TMJ) discs was studied immunohistochemically and compared with normal disc pattern in order to evaluate the expression of this adhesion molecule and correlate it to histopathological changes. Immunohistochemistry with anti-CD44H antibodies was performed on paraffin sections of pathological and normal discs. In normal TMJ discs, a moderate immunolabelling with anti-CD44H antibodies was detectable in fibroblastlike cells, in the few fibrochondrocytes and in chondrocytelike cells. In dysfunctional discs, the staining pattern and intensity varied according to the histopathological findings of the specimens. The TMJ discs showing abnormal collagen arrangement or fragmentation of collagen fibres presented overall the same immunolabelling pattern of normal discs. In the discs showing areas of fibrocartilaginous metaplasia, CD44H expression was upregulated in fibrochondrocytes and fibroblastlike cells, especially around the chondroid tissue. Overall, these results suggest that CD44H mediates the binding of some ECM proteins in TMJ disc cells. The up-regulation of CD44H observed in some dysfunctional TMJ discs seems to indicate a prevention of apoptosis in fibroblastlike cells and an important role in phenotypical change of fibrochondrocytes into chondroblastlike cells, enabling the aggregation of chondroid tissue pericellular matrix components.

Adult↗
PubMed1999

Alteration in alpha 2 integrin immunocytochemical expression on cultured human gingival fibroblasts following nicotine exposure.

BACKGROUND: Clinical epidemiologic studies carried out in smokers versus non smokers support the concept that tobacco-related factor may affect the periodontal tissues and wound healing. METHODS: In this study, the role of nicotine on the integrin alpha 2 chain immunocytochemical expression, in human gingival fibroblasts (HGF) was investigated in vitro. The kinetic induction of this type of integrin on HGF in response to increasing percentage of nicotine was been characterized. A human gingival fibroblast strain, derived from a healthy individual with non-inflamed gingiva, was used in this study. The cells were then grown on acetylated microscope slides and fixed with cold ethanol, samples were then incubated for 16 to 19 hrs at 4 degrees C to anti-human alpha 2 integrin chain monoclonal antibody. RESULTS: In control cultures and in HGF treated with 0.025 microM nicotine the initial higher expression of alpha 2 chain decreased (grade 1 in both culture) while in HGF treated with 0.075 microM increased (grade 3). After 48 hours HGF exposed to 0.075 microM nicotine, increased further their expression of alpha 2 chain. CONCLUSIONS: The results obtained demonstrate a dose-time dependent nicotine influence on immunocytochemical expression of alpha 2 integrin chain. These data suggest that nicotine may promote a collagene breakdown via an increase of alpha 2 integrin chain expression.

Cells, Cultured↗
PubMed1997

Anticardiolipin antibodies in pre-eclampsia and intrauterine growth retardation.

OBJECTIVE: To establish an association of anticardiolipin antibody (ACA) levels and pre-eclampsia or intrauterine growth retardation (IUGR). METHODS: Twenty-eight patients with pre-eclampsia, 28 with IUGR and 28 normotensive control group were matched for maternal age, race, weight, cigarette smoking, and parity. All had plasma anticardiolipin antibodies (GPL and MPL) detected by the modified enzyme-linked immuno-absorbent assay (ELISA) technique. RESULTS: No statistical significant difference in ACA values, both GPL and MPL, was found among the three groups studied Furthermore, none reached a value of ACA that could be considered clinically relevant (> 15). CONCLUSION: No association was found in anticardiolipin antibody levels between pre-eclamptic and IUGR versus the control group.

Adult↗
PubMed1997

[Respiratory medicine in the aged. Therapeutic problemsd].

Chronic obstructive pulmonary disease (COPD) is very common in the elderly, and its treatment needs special concern. Data from two clinical studies (in-patients of an Internal Medicine Department and Nursing-Home, respectively) have been evaluated in order to compare therapeutic approaches to COPD in three separate settings: home, hospital and Nursing-Home. Less than 50% of the overall patients received medical treatment according to the guidelines emerged in the literature. Although cardiovascular problems were highly common in out-patients, their bronchodilator therapy included systemic beta 2-agonists. Theophylline was the main drug prescribed to in-patients discharged from hospital, although inhaling beta 2-agonists were also recommended in few cases. Topical steroids have been widely used. Nursing-Home patients received mostly systemic steroids and few of them had theophylline and inhaling steroids. Anti-cholinergic drugs have never been employed in the overall population of elderly patients. Data concerning medical treatment of infectious respiratory diseases of Nursing-Home patients (both with and without COPD) have also been evaluated. Antimicrobial therapy has been performed according to the special needs of the elderly. During COPD reacutizations, beta 2-agonists and, again, theophylline consumption increased.

Adrenal Cortex Hormones↗