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Biomedical subjects

P De Fazio

Publications and source records attributed to P De Fazio.

At least 19 recordsLinked to original sources
PubMed2001

RB2/p130 gene-enhanced expression down-regulates vascular endothelial growth factor expression and inhibits angiogenesis in vivo.

Angiogenesis is an essential step in the progression of tumor formation and development. The switch to an angiogenetic phenotype can occur as a distinct step before progression to a neoplastic phenotype and is linked to genetic changes such as mutations in key cell cycle regulatory genes. The pathogenesis of the angiogenetic phenotype may involve the inactivation of tumor suppressor genes such as the "guardian of the genome," p53, and the cyclin-dependent kinase inhibitor p16. Retinoblastoma family member RB2/p130 encodes a cell cycle regulatory protein and has been found mutated in different tumor types. Overexpression of RB2/p130 not only suppresses tumor formation in nude mice but also causes regression of established tumor grafts, suggesting that RB2/p130 may modulate the angiogenetic balance. We found that induction of RB2/p130 expression using a tetracycline-regulated gene expression system as well as retroviral and adenoviral-mediated gene delivery inhibited angiogenesis in vivo. This correlated with pRb2/p130-mediated down-regulation of vascular endothelial growth factor protein expression both in vitro and in vivo.

Animals↗
PubMed2000

Localization of the e-NOS enzyme in endothelial cells and odontoblasts of healthy human dental pulp.

Nitric oxide synthases (NOS) are important enzymes present in different cells such as endothelial cells, macrophages, etc. Recently, it has been found that nitric oxide (NO) is responsible for vasodilation, blood pressure regulation, platelet aggregation, cardiac contractility, and the mediation of immunity during bacterial infections and inflammation. However, the production and role of NO in various structures of the oral cavity have not been investigated extensively. The aim of this study was to evaluate the presence of e-NOS in healthy human odontoblasts and endothelial cells of the dental pulp. Twenty healthy human dental pulps were collected and frozen and pulp slices were obtained using a cryostat. The e-NOS enzyme was revealed by immunohistochemical analysis and the enzyme level was detected by Western blotting and mRNA expression by RT-PCR. The immunohistochemical results demonstrated, for the first time, the presence of e-NOS in odontoblasts and in endothelial cells. The presence of e-NOS m-RNA was confirmed by RT-PCR and the expression of the protein by Western blotting. These results clearly show that the e-NOS enzyme is present in both odontoblasts and endothelial cells of healthy human pulp. The presence of e-NOS in the odontoblast and endothelial cells of the dental pulp may mediate local vasodilation and cell proliferation.

Blotting, Western↗
PubMed2000

Nuclear matrix provides linkage sites for translocated NF-kappa B: morphological evidence.

In response to the binding of extracellular ligands to cell surface receptors, multiple transcription factors are activated in the cytoplasm and translocated into the nucleus where they exert positive or negative control over cellular genes. The human transcription factor NF-kappa B family regulates the expression of a large number of genes involved in the host defence mechanism. They are typically present in the cytoplasm bound to the inhibitory I kappa B proteins. The activation of NF-kappa B involves the signal-induced degradation of these proteins, allowing NF-kappa B to translocate to the nucleus. In this study, by multiparametric analysis, we recognise in RPMI-8402 DMSO-activated cells the intracellular movement of transcription factor NF-kappa B providing its definite intranuclear collocation. Intact cells, purified nuclei and nuclear matrix preparations after 4 h of treatment were processed for morphological and biochemical analyses. Light and electron microscope observations show, in untreated cells, the presence of NF-kappa B protein homogeneously retained in the cytoplasm. Treated cells display a massive presence of NF-kappa B at the nuclear level bound to the interchromatin region. Immunoblotting of the same specimens confirms the strong association of NF-kappa B with the nuclear scaffold. Taken together, the data presented in this manuscript support a model where DMSO treatment provokes the cleavage and translocation of NF-kappa B from the cytoplasm to the nucleus and, in particular, in the proteinaceous network of the nuclear matrix sustaining the active role of this subcellular structure on regulation of eukaryotic gene expression.

Biological Transport↗
PubMed2000

Conventional and new antidepressant drugs in the elderly.

Depression in the elderly is nowadays a predominant health care problem, mainly due to the progressive aging of the population. It results from psychosocial stress, polypathology, as well as some biochemical changes which occur in the aged brain and can lead to cognitive impairments, increased symptoms from medical illness, higher utilization of health care services and increased rates of suicide and nonsuicide mortality. Therefore, it is very important to make an early diagnosis and a suitable pharmacological treatment, not only for resolving the acute episode, but also for preventing relapse and enhancing the quality of life. Age-related changes in pharmacokinetics and in pharmacodynamics have to be kept into account before prescribing an antidepressant therapy in an old patient. In this paper some of the most important and tolerated drugs in the elderly are reviewed. Tricyclic antidepressants have to be used carefully for their important side effects. Nortriptyline, amytriptiline, clomipramine and desipramine as well, seem to be the best tolerated tricyclics in old people. Second generation antidepressants are preferred for the elderly and those patients with heart disease as they have milder side effects and are less toxic in overdose and include the so called atypicals, such as selective serotonin reuptake inhibitors, serotonin noradrenalene reuptake inhibitors and noradrenaline reuptake inhibitors. Monoamine oxidase (MAO) inhibitors are useful drugs in resistant forms of depression in which the above mentioned drugs have no efficacy; the last generation drugs (reversible MAO inhibitors), such as meclobemide, seem to be very successful. Mood stabilizing drugs are widely used for preventing recurrences of depression and for preventing and treating bipolar illness. They include lithium, which is sometimes used especially to prevent recurrence of depression, even if its use is limited in old patients for its side effects, the anticonvulsants carbamazepine and valproic acid. Putative last generation mood stabilizing drugs include the dihydropyridine L-type calcium channel blockers and the anticonvulsants phenytoin, lamotrigine, gabapentin and topiramate, which have unique mechanisms of action and also merit further systematic study. Psychotherapy is often used as an adjunct to pharmacotherapy, while electroconvulsant therapy is used only in the elderly patients with severe depression, high risk of suicide or drug resistant forms.

Affect↗
PubMed2000

bcl-2, p53, and MIB-1 in human adult dental pulp.

Little is known about the renewal of some groups of cells in dental pulp, and the occurrence and significance of physiological cell death in dental pulp is not yet understood. The possibility of odontoblast disappearance by apoptosis has been proposed, and the presence of apoptotic cells in the rat and human odontoblastic and subodontoblastic layers has been recently described. bcl-2 and p53 are proteins involved in the apoptotic pathway, whereas MIB-1 is a proliferating cell marker. The aim of our study was an immunohistochemical evaluation of bcl-2, p53, and MIB-1 in healthy normal pulps of young human subjects. With bcl-2 immunostaining, some positive cells were found in the odontoblastic and subodontoblastic layers, whereas with MIB-1, only a few stromal cells were positive, and all odontoblasts were consistently negative. No cells were positive to p53. The bcl-2 immunoreactivity of the cells of the odontoblastic and subodontoblastic layers could help to explain the presence of apoptotic cells found in these regions.

Adolescent↗
PubMed2000

Broken instrument removal--two cases.

This paper reports two clinical aids for the removal of broken instruments in root canals using a combination of hand instrumentation and ultrasonic devices. This technique is based on two phases: hand instrumentation with stainless-steel K-file instruments for bypassing the fragments, and K-files mounted on an ultrasonic handpiece for loosening and retrieval of the broken instruments. This method offers the following advantages: conservation of the remaining dentin wall of the root canal and elimination of the necessity for surgical treatment.

Adult↗
PubMed1999

An evaluation of the action of different root canal irrigants on facultative aerobic-anaerobic, obligate anaerobic, and microaerophilic bacteria.

The aim of this study was to test the effect of different concentrations of sodium hypochlorite, chlorhexidine, and cetrimide on the following bacterial strains: Facultative aerobes-anaerobes: Candida albicans ATCC 10231; Enterococcus faecalis ATCC 29212; Escherichia coli ATCC 25,922; Pseudomonas aeruginosa ATCC 27,853; Streptococcus mitis ATCC 9811; Streptococcus mutans ATCC 35668; Streptococcus salivarius ATCC 13419; and Streptococcus sanguis ATCC 10556. Microaerophiles: Actinobacillus actinomycetemcomitans ATCC 29522. Obligate anaerobes: Actinomyces odontolyticus ATCC 17929; Fusobacterium nucleatum ATCC 25,586; Porphyromonas gingivalis ATCC 33277; and Prevotella melaninogenica ATCC 25845. Each irrigant was kept in contact with the bacterial species used for the experiment for 10, 20, or 30 min. Results showed that all irrigants had a bactericidal effect on both facultative aerobes-anaerobes and on microaerophilic and obligate anaerobic strains, in all concentrations and even after short periods of contact.

Anti-Infective Agents, Local↗
PubMed1996

Human recombinant interleukin-1 beta induces thromboxane A2 release in polymorphonuclear leukocytes, macrophages and platelets: effect of IL-1 receptor antagonist.

Prostaglandins and thromboxanes (Txs) are produced by polymorphonuclears (PMNs) and macrophages (Mphis) in response to various stimuli. PMNs were separated from other human blood cells and Mphis were separated from rat peritoneal lavage. In this paper we show that human recombinant interleukin-1 (hrIL-1) can stimulate the release of thromboxane B2 (TxB2) by PMNs and Mphis. In addition, we have shown that aggregation of PMNs may occur when calcium ions (7 mM) and hrIL-1 (100 ng/ml) are added to the cell preparation, but not when Ca2+ alone, hrIL-1 alone, or first hrIL-1 then calcium are added to the cell preparation. The treatment of human platelets with hrIL-1 shows that after 15 min incubation TxB2 is released. In addition, we compared the aggregation of platelets caused by ADP with that caused by hrIL-1. Human recombinant IL-1 at a concentration of 100 ng/ml also causes little aggregation of platelets, in this case the aggregation is reversible. In conclusion, hrIL-1 beta stimulates TxB2 release in PMNs, Mphis and platelets and this effect increases with addition of Ca2+ ions. The mixture of hrIL-1 and Ca2+ causes little aggregation of PMNs. In monocyte suspensions, pretreated with human recombinant IL-1 receptor antagonist (IL-1ra) 500 ng/ml for 10 min and then treated with LPS or hrIL-1 beta 10 micrograms/ml, the release of TxB2 was partially inhibited. IL-1ra may play a significant role in the control of IL-1 and LPS induction in the release of TxB2.

Adenosine Diphosphate↗
PubMed1995

Dental health and treatment needs in institutionalized psychiatric patients in Italy.

The caries prevalence, oral hygiene status, periodontal health and the treatment needs were assessed in a group of institutionalized psychiatric patients in Catanzaro, Italy. Of the total sample of 297 subjects, 165 (55.6%) were males, the mean age was 55.1 yr, the great majority (90.6%) was able to care for themselves, on average they had been institutionalized for 12.9 yr, and almost two-thirds were schizophrenic (65%). They did not receive any assistance in daily oral hygiene procedures, only 7.4% had visited a dentist and exclusively for emergency care. A total of 33 (11.1%) patients were edentulous, and the multiple logistic regression analysis showed a highly significant increase of edentulousness with increasing age (P < 0.001). No caries-free subjects were found and among the dentate the DMFT and DMFS scores for all age groups were respectively 15.5 and 88.6. The stepwise linear regression analysis showed that the mean DMFT index increased with age (t = 6.86; P < 0.001), and in the partly or totally helpless patients it was significantly higher than in the self-sufficient patients (t = 2.78; P = 0.006). Of the 264 dentate subjects, only 25 (9.5%) had no need of dental treatment; 213 (80.7%) required extractions with a mean number per person of 6.3 and the need for conservative dental care was recorded in 154 (58.3%) patients with a mean need for patient of 2.8. Mean OHI-S score was 4.2 and the stepwise linear regression analysis showed that it increased with age (t = 5.73; P < 0.001) and with the length of institutionalization (t = 3.42; P < 0.001). Only 0.9% of the entire sample was found with healthy periodontal tissue; bleeding on probing or a higher score was found in 4.6% of examined sextants; calculus in 10.1%; shallow pockets and deep pockets in 19.6% and 64.8% of all sextants. The results of the multiple logistic regression analysis indicated that the number of subjects with deep pockets as highest score increased with increasing age (P<0.001), and with the increasing length of institutionalization (P=0.005). The findings of this study demonstrate high caries prevalence, poor oral hygiene and periodontal health, and extensive unmet needs for dental treatment. More coordinated efforts between the social and dental care sector must be maintained to serve adequately the need of this disadvantaged group.

Adult↗
PubMed1992

Immunocytochemical detection of factor XIII A--subunit in acute leukemia.

Factor XIII (FXIII) is a plasma pro-transglutaminase consisting of A and B subunits in a tetrameric structure. A cellular form of FXIII consisting exclusively of A subunits exists in platelets and monocytes: monocyte FXIII may be involved in connective tissue organization. To evaluate the expression and diagnostic significance of FXIII A subunit (FXIIIA) in acute leukemia, we performed an immunocytochemical study (PAP technique) with rabbit antiserum against FXIIIA on leukemic blasts of 48 cases. FXIIIA was detected only in myelomonocytic (M4), monocytic (M5) and megakaryocytic (M7) cases: in M4 and M5 samples the amount of blast cytoplasmic FXIIIA was closely correlated with the expression of monocyte-specific antigenic and cytochemical markers. Our data show immunocytochemical detection of FXIIIA to be useful for acute leukemia characterization.

Acute Disease↗
PubMed1992

[Anticipatory anxiety and interpersonal relations with the radiologist of patients undergoing diagnostic imaging].

A pilot study has been carried out with the aim of evaluating the impact of updated imaging techniques (CT and MRI) versus "simple" examinations (tomography, X-rays, US, and nuclear medicine) on the anticipatory anxiety of the patients, as well as on the radiologist-patient relationship. Ninety consecutive patients undergoing diagnostic imaging modalities were examined according to the following schedule: 1) preliminary interview and anxiety assessment according to HRSA; 2) diagnostic imaging investigation, and 3) filling out an "ad hoc" questionnaire. The collected data have been divided into two groups: the "simple" group (52 patients submitted to X-rays, tomography, US, and nuclear medicine), and the "complex" group (38 patients submitted to CT and MRI). Anticipatory anxiety was observed in all subjects and attained psychopathological rates in more than half of them. Anxiety proved to be related to the completion of the examination rather than to its complexity. The questionnaire has pointed out the need for a more interactive relationship between radiologist and patient during diagnostic imaging examinations.

Adult↗
PubMed1991

[Understanding lateral and vertical gutta-percha condensation technique].

After a brief analysis of the materials and of the various techniques for filling root canals, the authors present the results obtained by a group of 5th year dental students of the Corso di Laurea in Odontoiatria e Protesi Dentaria from their first experiences at filling root canals. The techniques they used, lateral and vertical condensation of gutta-percha, were chosen for their widespread use and for the greater guarantee they offer. The results, which confirmed the expectations, show how lateral condensation is easier to perform by dentists with little experience. The vertical condensation technique, judging from our results, should be used only after a dentist has acquired experience and skill, because in the cases we observed there was a consistent unsatisfactory apical closure.

Gutta-Percha↗
PubMed1990

5' Nucleotidase in chronic B cell leukemias: a cytochemical and ultrastructural study.

We studied by cytochemical means the distribution of 5' nucleotidase (5' NT), a purine degradative enzyme, in the circulating lymphocytes of 24 healthy donors and 41 cases of chronic lymphoid leukemias, classified according to morphological and immunological criteria. About half the normal circulating lymphocytes were 5'NT positive and exhibited variable degrees of enzyme activity. Among chronic B lymphocytic leukemias we found high percentages of positive cells only in the phenotypically more mature cases. Moreover all cases of hairy cell, follicular cell, lymphoplasmacytic, and plasma cell leukemia showed moderate or weak 5' NT reactivity. Also one case of chronic T lymphocytic leukemia, CD8 positive, was moderately positive, while another, with large granular lymphocyte morphology, was completely negative. Electron microscopy revealed a discontinuous, granular plasma membrane reaction pattern, varying in intensity from case to case. In conclusion, our results confirm the usefulness of the 5' NT cytochemical reaction for identification of lymphoid populations at different stages of maturation in chronic B cell disorders.

5'-Nucleotidase↗
PubMed1990

Immunocytochemical detection of ferritin in human bone marrow and peripheral blood cells using monoclonal antibodies specific for the H and L subunit.

We have used the monoclonal antibodies 2A4 (specific for the H subunit of human ferritin) and LO3 (specific for the L subunit) for immunocytochemical detection of ferritin in bone marrow and peripheral blood cells from normal subjects and patients with various haematological disorders. Formalin-fixed slides were stained by the immunoalkaline phosphatase procedure (APAAP). In normal subjects, ferritin could be found only in bone marrow smears and appeared to be largely confined to erythroid precursors and reticuloendothelial cells. The more immature erythroid precursors contained higher concentrations of cellular ferritin. Although evaluation could be only semiquantitative, erythroblast ferritin appeared to be more reactive with the monoclonal 2A4 (15 +/- 7% positive erythroblasts) than with the monoclonal LO3 (6 +/- 5% positive erythroblasts), indicating that H-type ferritin was predominant, particularly in proerythroblasts and basophilic erythroblasts. By contrast, the ferritin present in reticuloendothelial cells appeared to be predominantly of L-type. Patients with iron deficiency showed low levels of positive erythroblast, whereas the reverse was true in patients with transfusional iron overload. Intense positivity for reticuloendothelial cell ferritin was found in patients with anaemia of chronic disease. In myelodysplastic syndromes and acute myeloid leukaemia (AML), ferritin positivity was generally very strong at any stage of erythroblast development, particularly with the monoclonal antibody 2A4. Perls-positive perinuclear granules of ring sideroblasts were not stained, confirming that mitochondrial iron deposition is not in the form of ferritin. In AML and myelodysplastic syndromes with excess of blasts, ferritin could be detected also in immature myeloid cells. These data indicate that: (a) in normal conditions ferritin is mainly expressed in red cell precursors and reticuloendothelial cells, and this is in keeping with the peculiar role of these cells in iron metabolism; (b) abnormal cell ferritin contents can be observed in both iron overload and malignancy.

Antibodies, Monoclonal↗
PubMed1990

[Condensation of gutta percha after McSpadden].

The Authors have studied the efficacy of the sealing effect of thermomechanical compaction of guttapercha according to McSpadden with an in vitro analysis on undecalcified tooth sections and with a clinical evaluation of ten patients with periapical lesions. The analysis of the results has shown a good sealing capacity of the McSpadden technique.

Dental Leakage↗
PubMed1990

[Comparison of calcium hydroxide and calcium oxide for intracanal medication].

The authors show how the proper use of the root canal medication based on calcium oxide is determinant for causing a perfect asepsis of the root canal in the 58 teeth, taken in consideration, the calcium oxide is more efficacious than the calcium hydroxide not only because it produces a remarkable decrease of the bacterial quantity, but also because the recovery time of the lesion before the filling up of the root canal, is less than half time in comparison with that one got by means of the calcium hydroxide.

Adolescent↗
PubMed1990

[Effects of paraformaldehyde steam sterilization on K-files].

Success of endodontic therapy depends upon both operator's skill and quality of the employed instruments. K-files have been examined for they probably are the most commonly used endodontic instruments. It is particularly important to take into consideration, together with the original quality of the instruments, its possible changes due to the wear from sterilization. In this paper have been therefore evaluated the characteristics of brand-new K-files from three different manufacturers together with the wear of the same instruments after paraformaldehyde steam sterilization.

Corrosion↗