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Biomedical subjects

R Petracca

Publications and source records attributed to R Petracca.

27 records · Page 2Linked to original sources
PubMed1990

Immunohistochemical localization of filaggrin in benign and malignant lesions of the human oral mucosa.

Filaggrin is a protein normally present in the granular and horny layer of stratified squamous epithelia. We studied the presence of this protein in 83 benign lesions and in 73 cases of malignant epithelial tumours of the oral cavity and investigated its possible role as an immunohistochemical marker. The immunohistochemical technique was based on the P.A.P. method. The results in benign lesions show a distribution of filaggrin similar to that observed in the normal mucosa. By contrast, an irregular distribution of filaggrin is observed in areas of leukoplakia with parakeratosis and in papillomas. In malignant lesions the expression of this protein is closely related to the degree of differentiation of the cellular elements, being positive in more differentiated and negative in anaplastic areas. Therefore in some types of benign lesions filaggrin testifies an alteration of the normal process of keratinization. Filaggrin is more significant in malignant lesions in which its presence if any permits an evaluation of the degree of differentiation of the tumour.

Carcinoma, Squamous Cell↗
PubMed1988

Altered expression of filaggrin in human papillomavirus (HPV) lesions of the uterine cervix.

A series of 64 punch biopsies collected from women prospectively followed-up for cervical Human papillomavirus (HPV) infections (with and without CIN), and 38 control biopsies (normal epithelia, and classical CIN) were analysed for expression of filaggrin (a histidine-rich protein constituent of keratohyalin granules) using the ABC technique and polyclonal antibody. HPV typing was completed using the in situ hybridization technique with DNA probes for HPV 6, 11, 16, 18 and 31. Three patterns of filaggrin distribution were differentiated: pattern I, all layers above the basal cells stained positive regularly; pattern II, all layers above the basal cells stained irregularly, and pattern III, scattered superficial cells stained positive. There was a significant difference between HPV-noCIN and HPV-CIN lesions in their filaggrin patterns, pattern I being present in the majority (77.7%) of HPV-noCIN lesions, as contrasted to HPV-CIN lesions, where pattern III was the predominant one (43.5%), followed by pattern II (32.6%). In HPV-CIN as well as in CIN lesions, pattern I was inversely related to the grade of CIN, being entirely absent in HPV-CIN III and CIN III. A significant difference exists between CIN and HPV-CIN lesions, concerning the presence of pattern III (4.3% and 43.5%, respectively, P less than 0.001). The difference was less dramatic with regard to pattern I (30.4% and 21.7%, respectively, P less than 0.05). In the lesions containing HPV 6, 11 or 31 DNA, filaggrin distribution was shown to be more close to that of the normal epithelium (I 36.7%, and II 34.7%), while in the HPV 16 and 18-infected cases, pattern III was the predominant one (46.7%). The assessment of filaggrin pattern in HPV lesions might be of help in evaluating the severity of the disturbance of keratinocyte differentiation induced by the progression of HPV infections.

Cervix Uteri↗
PubMed1988

Cytokeratin pattern in normal and pathological bladder urothelium: immunohistochemical investigation using monoclonal antibodies.

Normal bladder urothelium and large spectrum bladder lesions have been investigated by immunohistochemistry with monoclonal antibodies of variable specificity (SK 56-23, a large spectrum antibody; SK 60-61, which reacts with cytokeratin polypeptides no. 8 and 18 of Moll's catalogue; SK 2-27, specific for polypeptides no. 14, 16 and 17). The normal urothelial pattern is in agreement with previous reports. In pathological conditions, modified immunostaining has been demonstrated in almost all cases. In detail, the cytoskeletal pattern detected in transitional cell papilloma seems to discriminate between types which are otherwise histologically similar. We also observed a correlation between higher degrees of malignancy and loss of specialization, as demonstrated by the increasing positivity for SK 60-61, which as a rule specifically stains "umbrella" cells, and SK 2-27, an antibody exclusively detected in cells of the basal layer. These findings indicate that the cytokeratin pattern may constitute a modern new tool for the pathologist in the diagnosis of urothelial proliferative disorders.

Antibodies, Monoclonal↗
PubMed1985

Adenosine receptors on human inflammatory cells.

Adenosine is a natural nucleoside that plays a physiological role in the modulation of human inflammatory cells. We have investigated the presence of adenosine A2/Ra and A1/Ri receptors and of the P-site on human inflammatory cells. Human B and T(OKT4+ and OKT8+) lymphocytes, polymorphonuclear leucocytes, monocytes, basophils and platelets possess a membrane adenosine A2/Ra receptor. The activation of adenosine A2/Ra receptor increases the intracellular level of cyclic AMP in these cells. Human lymphocytes and neutrophils possess also an inhibitory adenosine A1/Ri receptor and a P-site whose activation inhibits the effect of many adenylate cyclase agonists including isoproterenol, PGE1, histamine, adenosine, cholera toxin and forskolin.

Adenosine↗
PubMed1982

Activation of human basophils by staphylococcal protein A. I. The role of cyclic AMP, arachidonic acid metabolites, microtubules and microfilaments.

Protein A from Staphylococcus aureus (Staph A) induces histamine secretion from human basophil leucocytes in the concentration range 10(-4) - 10 micrograms/ml. This reaction has great similarities to that of antigen or anti-IgE-induced release. It is characterized by a two stage reaction, requires extracellular calcium and is optimal at 37 degrees C. The rate of release is similar to that of IgE-mediated reactions. Histamine release induced by Staph A is inhibited by metabolic inhibitors, drugs which increase intracellular cyclic AMP levels, inhibitors of lipoxygenase pathways and a phospholipase A2 inhibitor. D2O and cytochalasin B which affect microtubules and microfilaments respectively, enhance histamine release induced by Staph A. These results suggest that Staph A-induced release is modulated by intracellular cyclic AMP, arachidonic acid metabolites, requires energy and is enhanced by the disruption of microfilaments and stabilization of microtubules.

Arachidonic Acids↗
PubMedDate not supplied

Betamethasone increases the beta-adrenergic receptor density of human polymorphonuclear leukocytes.

Prolonged incubation (18h) of human polymorphonuclear leukocytes (PMNs) with betamethasone (BT) (10(-7) M) increased (3H)-DHA binding to human PMN membranes, apparently causing an increase in the number of beta-adrenergic receptors. Inhibition of this effect by cycloheximide (2 micrograms/ml) suggests that it is dependent on protein synthesis. BT had no effect on basal levels of cAMP in PMNs, but synergistically potentiated the increase in cyclic AMP (cAMP) induced by isoproterenol. Propranolol completely abolished the synergistic effect of BT plus isoproterenol, suggesting that the potentiating effect of BT on cAMP metabolism required the activation of beta-adrenergic receptors. Thus, BT increased the number of beta-adrenergic receptors in human PMN membranes and potentiated the cAMP changes induced by beta-agonists.

Betamethasone↗
PubMedDate not supplied

Studies of the mechanisms underlying impairment of beta-adrenoceptor-mediated effects in human hypertension.

To investigate the impairment of beta-adrenoceptor responsiveness in human hypertension, we evaluated the effect of an oral salt load (400 mEq/day of NaCl for 7 days) on plasma catecholamine concentrations and beta-adrenoceptor-mediated effects in 11 young patients with mild essential hypertension. Responses of heart rate and plasma cAMP to isoproterenol administration were used as indices of beta-adrenoceptor responsiveness. Salt loading induced a significant reduction in the dose of isoproterenol required to raise the heart rate by 25 bpm (CD25) (from 7.6 +/- 1.5 to 5.3 +/- 0.9 micrograms, p less than 0.05) and an increase in the slopes of the regression lines for heart rate changes and isoproterenol doses (delta HR/IS) (from 3.3 +/- 0.6 to 4.7 +/- 0.7, p less than 0.05) and for plasma cyclic AMP (cAMP) level changes and isoproterenol doses (delta cAMP/IS) (from 0.3 +/- 0.06 to 1.4 +/- 0.3, p less than 0.05). After salt loading there was a significant reduction in plasma catecholamine concentrations with a significant relationship between changes in upright plasma epinephrine levels and changes in CD25 (r = 0.904, p less than 0.01) and in the slopes for delta HR/IS (r = 0.983, p less than 0.001) and delta cAMP/IS (r = 0.922, p less than 0.001). These results support the hypothesis that the impairment of beta-adrenoceptor sensitivity observed in human hypertension is associated with a beta-adrenoceptor overstimulation due to chronically elevated adrenergic tone.

Adolescent↗
PubMedDate not supplied

[Hystersoscopy: instrumentation and techniques].

This paper was presented at the 1st Update Course in Hysteroscopy and Microcolpohysteroscopy organised by LAMM and held at the 1st Institute of Obstetrics and Gynecology at Policlinico Umberto I in Rome. The paper is divided into three sections: the first section describes the technical instruments used during hysteroscopy (light source, means of distending the uterine cavity, optic systems); the second reports the technique used in hysteroscopic examination: in particular, the authors underline the importance where necessary (i.e. in young patients with stenosis of the cervical canal and in elderly patients with atrophy of the neck of the uterus or conglutination of the external uterine operning) of preceding dilatation of the cervical canal by the use of endovaginal prostaglandin derivatives in order to render it less traumatic. Moreover, the authors attempt to simplify the technique as much as possible so as to render it a routine or ambulatorial test; the third section describes complications of the hysteroscopic examination, in order of frequency, as well as methods of storing and disinfecting the instruments used in hysteroscopy.

Female↗