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Biomedical subjects

E Bucci

Publications and source records attributed to E Bucci.

At least 19 recordsLinked to original sources
PubMed2001

Satellite potentials on EMG: neurophysiologic evidence of axonal transection in MS?

To detect signs of axonal damage in MS, the authors investigated the occurrence in EMG of motor unit action potentials with satellite potentials (SP-MUAP) in the upper limb muscles in 10 consecutive patients with MS with cervical spinal cord demyelinating lesions and 10 control subjects. Subjects' SP-MUAP rate was 0 to 2.5% (median 0%) in the control group, and 0 to 17.5% (median 7.5%) in the MS group (p < 0.01). Motor unit remodeling secondary to axonal transection of spinal motor neurons traversing cervical demyelinating lesions may be hypothesized.

Adult↗
PubMed2001

Clinical guidelines in early detection of oral squamous cell carcinoma arising in oral lichen planus: a 5-year experience.

In recent years, studies on the malignant potential of oral lichen planus (OLP) provided clinical evidence that patients affected by OLP have an increased risk to develop oral squamous cell carcinoma (OSCC); nevertheless, controversies still exist as to whether OLP has inherent predisposition to become malignant, or not. We believe extremely careful management of OLP patient is mandatory, and the aim of this paper is to illustrate our clinical guidelines in evaluating the possible risk of transformation in OLP lesions. Five-hundred and two patients (311 women and 191 men) affected by OLP regularly undergo follow-up examination in our Department. Patients' ages range from 18 to 83 years, with a mean of 55.4 years (57.5 for women and 53.9 for men); minimal follow-up period is 4 months, with a maximum of 12 years. In our group of OLP patients in the past 5 years we detected 24 carcinomas: excluding three cases in which diagnoses of OLP and OSCC were synchronous and three patients who had a history of tobacco use, thus possible malignant transformation of OLP would appear to be 3.7%. Clinical criteria used in our follow-up allowed us to detect 28.5% of tumours as in situ OSCC, 38% as microinvasive OSCC, 28.5% as stage I OSCC and 4.7% as stage II OSCC, with a remarkable improvement in prognosis compared to our previous study in which we adopted different criteria.

Adult↗
PubMed2001

Clinical features of gingival pemphigus vulgaris.

BACKGROUND: Pemphigus vulgaris (PV) is a rare, chronic, intraepithelial bullous disease with a potentially fatal outcome. Oral lesions are a hallmark of PV and occur in almost all cases, and represent the preliminary symptom in more than half of the patients. Gingival lesions are very common and, when solitary, often first recognized by periodontist. METHOD: In the literature, gingival localization of PV are usually described as desquamative gingivitis (DG) and/or as vesiculobullous lesions of the free and attached gingiva; in our experience, early lesions only rarely appears as extensive erythema and erosions. CONCLUSIONS: PV at the onset may frequently appear on gingiva as isolated blisters and/or erosions mainly located to the free gingiva, very little in extension and hardly to recognize as bullous lesions.

Biopsy↗
PubMed2001

Catenin dislocation in oral pemphigus vulgaris.

Cell-to-cell adhesion is mediated by cadherins (integral membrane proteins), which form a complex with catenins (cytoplasmatic proteins). While E-cadherin expression has been extensively studied in many human skin diseases, less is known about the expression levels of catenins in oral blistering diseases. The purpose of this study was to evaluate the role of these proteins in the pathogenesis of acantholysis in oral pemphigus vulgaris. We evaluated by immunohistochemistry beta- and gamma-catenin expression in 7 cases of oral pemphigus vulgaris (PV) at various stages of the disease and, as controls, in 18 healthy patients. Healthy cases showed, as reported in the literature, a strong reactivity with both beta- and gamma-catenins, with the intensity of staining progressively decreasing from the spinous to the keratinised layers of epithelium, which had a prevalent cellular membrane expression. In PV patients, we detected a loss of membrane expression of these molecules with a progressive displacement of the signal toward the cytosol and, for gamma-catenin, nuclear dislocation, particularly in areas with intense acantholysis.

Adult↗
PubMed2001

The treatment of oral aphthous ulceration or erosive lichen planus with topical clobetasol propionate in three preparations: a clinical and pilot study on 54 patients.

BACKGROUND: This study evaluated the clinical use of a corticosteroid in three preparations (topical clobetasol propionate ointment, clobetasol propionate in an oral analgesic base, and clobetasol propionate in an adhesive denture paste). METHODS: Fifty-four patients (34 males and 20 females) with a history of vesiculo-ulcero-erosive oral lesions were selected: 24 with oral erosive lichen planus and 30 with aphthae. The subjects enrolled were randomly divided into three groups, each of 18 patients (10 with aphthae and 8 with lichen planus): the first was treated with topical clobetasol propionate ointment (0.05%) directly on the lesion(s) three times a day; the second with clobetasol propionate in an adhesive denture paste in equal amounts (1:1) two times a day; the third with clobetasol propionate in an oral analgesic base (Orabase-B) in equal amounts (1:1) two times a day. Each subject scored his or her symptoms daily from most severe (7) to none (0) by verbal assessments using a categorical scale. RESULTS: In all cases, the administration of the corticosteroid was effective in producing remission of symptoms in each group of patients. Significant differences (P<0.05) between groups were determined by the Kruskal-Wallis test. The Dunn test was used in order to detect which group differs from the others; clobetasol and adhesive denture paste correlated with an early remission of pain in lichen and apthous lesions. CONCLUSION: The results suggest that topical application of clobetasol in an adhesive denture paste is an effective drug for symptomatic oral vesiculo-erosive and/or ulcerative lesions.

Adhesives↗
PubMed2001

Lack of hypercapnic increase in cerebral blood flow at high blood viscosity in conscious blood-exchanged rats.

BACKGROUND: The hypothesis of a compensatory dilation of cerebral vessels to maintain cerebral blood flow at a high blood viscosity was tested during hypercapnia in the study after replacement of blood by hemoglobin solutions of defined viscosities. If compensatory vasodilation exists at normocapnia at a high blood viscosity, vasodilatory mechanisms may be exhausted when hypercapnia is added, resulting in a lack of increase in cerebral blood flow at hypercapnia. METHODS: In conscious rats, blood was replaced by ultrapurified cross-linked hemoglobin solutions that had defined and shear rate-independent low or high viscosities (low- and high-viscosity groups). Blood viscosity differed threefold between both groups (1.2 vs. 3.6 mP x s). Thereafter, rats inhaled either a normal or an increased concentration of carbon dioxide in air. Cerebral blood flow was determined by the iodo[14C]antipyrine method. RESULTS: During normocapnia, global and local cerebral blood flows did not differ between both groups. With increasing degrees of hypercapnia, global and local cerebral blood flows were gradually elevated in the low-viscosity group (2.8 ml x mmHg(-1) CO2 x 100 g(-1) x min(-1)), whereas they remained unchanged in the high-viscosity group. CONCLUSIONS: Changes in blood viscosity do not result in changes of cerebral blood flow as long as cerebral vessels can compensate for these changes by vasodilation or vasoconstriction. However, such vascular compensatory adjustments may be exhausted in their response to further pathophysiologic conditions in blood vessels that have already been dilated or constricted as a result of changes in blood viscosity.

Animals↗
PubMed2000

Adipyl crosslinked bovine hemoglobins as new models of allosteric systems.

As indicated by peptide analyses and mass spectrometry estimations, intramolecular crosslink with bis(3,5-dibromosalicyl)adipate of bovine hemoglobin results in the formation of two main components covalently bridged across the beta-cleft. In one component the crosslink joins the beta(1)V1-beta(2)K81 residues (XL-Peak-1), in the other the bridge is between the beta(1)K81-beta(2)K81 residues (XL-Peak-2). Both components are tetrameric with a mass near MW = 67 kDa as estimated by gel filtration, and a hydrodynamic radius near 3. 20 nm, estimated by dynamic light scattering. They have very low oxygen affinity with Pm near 100 mmHg (XL-Peak-1) and near 70 mmHg (XL-Peak-2) respectively at 37 degrees C, at neutral pH. The Bohr effect is almost absent in XL-Peak-1, while in XL-Peak-2 it is very near normal. Both systems show oxygen binding cooperativity with an index near n = 2.0. Flash photolysis kinetics of the recombination with CO could be resolved into a fast and a slow component. The amplitude of the fast rates were not concentration-dependent. The stopped-flow kinetics were autoaccelerating, consistent with their ligand-binding cooperativity. All rates were very similar to those of normal hemoglobin, suggesting that the oxy- rather than the deoxy-forms of the systems were affected by the crosslink. Proteins 2000;39:166-169.

Allosteric Site↗
PubMed2000

The two dimeric forms of RNase A.

In 1965 Fruchter and Crestfield (J. Biol. Chem. 240, 2868-3874) observed that dimeric RNase A prepared by lyophilization from acetic acid could be separated into two forms. Surprisingly, no other structural or functional differences could be detected between the two forms. In 1998 a structure for dimeric RNase A was determined by X-ray crystallography by Liu et al. (Proc. Natl. Acad. Sci. USA 95, 3437-3442). We found that the two forms of dimeric RNase A have indeed different structural and functional properties, and suggest that the dimer whose structure was investigated by Liu and coworkers may be identified with the lesser form of dimeric RNase A.

Animals↗
PubMed2000

Effect of lengthening of peptide backbone by insertion of chiral beta-homo amino acid residues: conformational behavior of linear peptides containing alternating L-leucine and beta-homo L-leucine residues.

The synthesis and the solution behavior of the linear peptides containing a beta-homo (beta-H) leucine residue-Boc-Leu-beta-HLeu-Leu-OMe, Boc-beta-HLeu-Leu-beta-HLeu-Leu-OMe, and Boc-Leu-beta-HLeu-Leu-beta-HLeu-Leu-OMe-as well as the solid structure of the tripeptide, are reported. The conformational behavior of the peptides was investigated in solution by two-dimensional nmr. Our data support the existence in solution with different families of conformers in rapid interchange. The crystals of the tripeptide are orthorhombic, space group P2(1)2(1)2, with a = 15.829(1) A, b = 29.659(1) A, c = 6.563(1) A, and Z = 4. The structure has been solved by direct methods and refined to final R1 and wR2 indexes of 0.0530 and 0.1436 for 2420 reflections with I > 2sigma(I). In the solid state, the tripeptide does not present intramolecular H bonds, and the peptide backbone of the two leucine residues adopts a quasi-extended conformation. For the beta-HLeu residue, the backbone conformation is specified by the torsion angles straight phi(2) = -120.9(4) degrees, mu(2) = 56.7(4) degrees, psi(3) = -133.2(4) degrees. The side chains of the three residues assume the same conformation (g(-), g(-), trans), and all peptide bonds, except the urethane group at the N-terminus, are in the trans conformation. Preliminary conformational energy calculations carried out on the Ac-NH-beta-HAla-NHMe underline that the conformations with mu angle equal to 180 degrees and 60 degrees assume lower energy with respect to the others. In addition, we found a larger conformational freedom for the psi angle with respect to the straight phi angle.

Crystallography, X-Ray↗
PubMed2000

In vivo administration of GM-CSF promotes the clearance of apoptotic cells: effects on monocytes and polymorphonuclear leukocytes.

The clearance of apoptotic cells is crucial to avoid chronic inflammation and autoimmunity. Little is known about the factors that regulate it in vivo. We show that granulocyte-macrophage colony-stimulating factor (GM-CSF) administration to carcinoma patients confers to their leukocytes a significantly higher ability to phagocytose apoptotic cells than before (P < 0.005). GM-CSF increased the concentration of monocytes and polymorphonuclear leukocytes in the peripheral blood and activated circulating polymorphonuclear leukocytes. Both effects abated early after treatment, whereas phagocytosis of apoptotic cells was still significantly higher after 18 days compared with basal values (P < 0.005 and P < 0.025 for monocytes and polymorphonuclear leukocytes, respectively). On in vitro phagocytosis of apoptotic cells monocytes, but not polymorphonuclear leukocytes, up-regulated MHC class II membrane expression. These findings are consistent with the possibility that GM-CSF endows both scavenger and antigen-presenting leukocytes with the ability to internalize apoptotic tumor cells.

Adult↗
PubMed2000

Oral pemphigus: long term behaviour and clinical response to treatment with deflazacort in sixteen cases.

Systemic corticosteroids remain the mainstay of therapy for pemphigus. Their use has transformed what was almost invariably a fatal illness into one whose mortality is now below 10%. Unfortunately, the high doses and prolonged administration of corticosteroids that are often needed to control the disease result in numerous side effects, many of which are serious or even life-threatening. Sixteen patients affected by oral pemphigus vulgaris were retrospectively examined to illustrate the natural course of the disease and to describe the efficacy of the treatment we utilised. Deflazacort, used with azathioprine, is the steroid of first choice in our therapeutic protocols, while cyclophosphamide and methylprednisolone "pulse therapy" are reserved for cases unresponsive to high doses of oral corticosteroids. In addition, the literature on oral pemphigus vulgaris was reviewed with respect to clinical history, signs and symptoms, management, and treatment outcome.

Administration, Oral↗
PubMed2000

Oral lichen planus: different clinical features in HCV-positive and HCV-negative patients.

BACKGROUND: Hepatitis C virus (HCV) infection induces variable dermatologic manifestations. OBJECTIVE: To determine whether differences exist in the clinical features and behavior of oral lichen planus (OLP) between HCV-positive (HCV+ve) and HCV-negative (HCV-ve) patients. METHODS: Two hundred and sixty three patients (156 women and 107 men), with a mean age of 55.5 years, with OLP (76 HCV+ve and 187 HCV-ve) were clinically evaluated. Previously, all local factors that could modify the clinical characteristics were removed and were monitored carefully following morphology. RESULTS: In both groups, the prevalent clinical form of OLP was the mixed form (33.1% in HCV-ve and 35.5% in HCV+ve patients), in which reticular-plaque lesions coexist with atrophic-erosive ones. The reticular form was more frequent in HCV+ve (25%) than in HCV-ve (18. 7%) patients, whereas plaque lesions were more prevalent in HCV-ve (15.5%) than in HCV+ve (5.2%) patients (P < 0.01, chi-squared test). There were no significant differences in the frequency of erosive (27.2% in HCV-ve and 27.6% in HCV+ve) and atrophic (5.3% in HCV-ve and 5.2% in HCV+ve) forms between the two groups. CONCLUSIONS: Our findings show that there were statistically significant differences between OLP-HCV-ve and OLP-HCV+ve groups for reticular and plaque clinical forms. These findings underline the importance of liver examination in all OLP patients, including cases with mild, asymptomatic keratotic forms of the disease.

Adult↗
PubMed2000

Appearance of dissociable and cross-linked hemoglobins in the renal hilar lymph.

Unlike unmodified dissociable bovine hemoglobin (UHb), cross-linked hemoglobins do not dissociate into dimers, do not cross the glomerular filter, and are retained in the plasma for a longer time. Renal peritubular capillaries, which are different from the glomerulus, allow the passage of molecules as large as albumin into the renal interstitium. Cross-linked hemoglobins should pass across these capillaries, enter the renal interstitium, and drain through the renal lymphatics. The present experiments were done in anesthetized rats to determine the appearance of UHb, an intramolecularly cross-linked tetrameric hemoglobin (DECHb), and a polymerized bovine hemoglobin (PHb) of larger molecular size into the renal hilar lymph. Renal hilar lymph samples were obtained before and after an isovolemic exchange of 2 mL/100 g rat weight of a 6% solution of each hemoglobin for blood. The behavior of a 5% solution of Evan's blue-labeled albumin was also determined for comparison. After exchange, the Initial plasma concentration of each of the proteins was in excess of 20 mg/mL. UHb appeared both in urine and lymph. DECHb, PHb, and albumin were absent from the urine but appeared promptly in the renal hilar lymph and reached concentrations at least 30% that of plasma. PHb had a significantly smaller lymph clearance (in microliters per minute) and longer plasma half-time than the other nondissociable proteins. These findings indicate that DECHb and PHb, although not filtered, pass across peritubular capillaries and readily enter the renal interstitial space. The passage of the larger molecular-sized PHb may be hindered relative to the other proteins in passage across peritubular and other systemic capillaries.

Albumins↗
PubMed2000

Computational procedures to explain the different biological activity of DNA/DNA, DNA/PNA and PNA/PNA hybrid molecules mimicking NF-kappaB binding sites.

Peptide nucleic acids (PNA) have recently been proposed as alternative reagents in experiments aimed to the control of gene expression. In PNAs, the pseudopeptide backbone is composed of N-(2-aminoethyl)glycine units and therefore is stable in human serum and cellular extracts. PNAs hybridize with high affinity to complementary sequences of single-stranded RNA and DNA, forming Watson-Crick double helices and giving rise to highly stable (PNA)2-RNA triplexes with RNA targets. Therefore, antisense and antigene PNAs have been synthetized and characterized. The major issue of the present paper is to describe some computational procedures useful to compare the behaviour of PNA double stranded molecules and PNA/DNA hybrids with the behaviour of regular DNA duplexes in generating complexes with DNA-binding proteins. The performed computational analyses clearly allow to predict that the lack of charged phosphate groups and the different shape of helix play a critical role in the binding efficiency of NF-kappaB transcription factors. These computational analyses are in agreement with competitive gel shift and UV-cross linking experiments. These experiments demonstrate that NF-kappaB PNA/PNA hybrids do not interact efficiently with proteins recognizing the NF-kappaB binding sites in genomic sequences. In addition, the data obtained indicate that the same NF-kappaB binding proteins recognize both the NF-kappaB DNA/PNA and DNA/DNA hybrids, but the molecular complexes generated with NF-kappaB DNA/PNA hybrids are less stable than those generated with NF-kappaB target DNA/DNA molecules.

Base Sequence↗
PubMed2000

Oral tuberculosis: a clinical evaluation of 42 cases.

OBJECTIVES: A retrospective review of a large series of oro-facial cases of tuberculosis to analyse clinical, histopathological, and radiological aspects, as well as those of chemotherapy. MATERIALS AND METHODS: A total of 42 cases of tuberculosis of the oro-facial region were examined. Thirteen patients had a primary form and 29 a secondary form of the disease. Diagnosis was based on careful clinical examination, Mantoux reaction, histopathological examination, microbiological cultures and immunological investigation with the detection of antibodies against Mycobacteria in the patients' serum (ELISA). RESULTS: Cases examined consisted of 27 males and 15 females. The age range was 3 to 73 years (mean age 31 years). Clinical manifestations comprised oral ulcers in 69.1%, bone involvement in 21.4%, and salivary gland and/or lymph node involvement in 14.3%. A total of 79.4% patients with secondary disease had pulmonary lesions, 15 of whom showed clinical and radiological signs of activity; there was one case of bilateral renal lesions and two of skin lesions. CONCLUSIONS: Oro-facial tuberculosis is often difficult to diagnose and it should be an important consideration in the differential diagnosis of lesions that appear in the oral cavity. The most important diagnostic tools remain a careful clinical evaluation, biopsy for histologic study, as well as acid-fast stains, culture, and immunological assays, and skin testing.

Adolescent↗
PubMed1999

A new solid-phase synthesis of oligonucleotides 3'-conjugated with peptides.

A convenient 'on line' solid-phase synthesis of oligonucleotides conjugated at the 3'-end with peptides by means of a polymeric support linking the first nucleoside via the base has been developed. A 17-mer designed for antisense experiments against HIV-1, linking at the 3'-terminus the tripeptide Gly-Gly-His, was prepared in good yields and characterized by MALDI-TOF mass spectrometry.

Chemistry↗