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Biomedical subjects

A Ricci

Publications and source records attributed to A Ricci.

At least 127 records · Page 7Linked to original sources
PubMed1997

[Prevalence of venous diseases. The San Valentino screening and prevalence study].

The PAP/PEA (Prevalence of Early Atherosclerosis) study aims to define the prevalence of subclinical atherosclerosis in a typical population of central Italy. A concomitant study evaluates the prevalence of venous diseases. The first group of 850 patients evaluated, indicated the prevalence of superficial ve-nous disease, the prevalence of deep venous thrombosis and pulmonary embolism and the prevalence of the most common venous malformations. Also the costs of venous problems was considered. In conclusion some 12% of the evaluated population sample (male population 46%) had or had been affected in the past by a venous problem and 50% of them had been under some form of treatment.

Adolescent↗
PubMed1997

Circadian pattern of post-surgical fatal pulmonary embolism.

BACKGROUND: The circadian distribution of fatal pulmonary thromboembolism in general surgical patients is unknown. PATIENTS AND METHODS: One hundred consecutive cases of pulmonary embolism, with reliable clinical notes and data, were studied (67 men and 33 women; mean age 71 years). Only post-surgical cases were considered in this analysis. Patients had undergone elective (78%) or emergency abdominal surgery (22%). Correct prophylaxis (according to the Windsor Consensus Statement) had been used in 12%. Cases were grouped according to the time of onset of signs and symptoms related to pulmonary embolism at one hour intervals. RESULTS: The maximum incidence of fatal pulmonary embolism was between 7.00 a. m. and 1.00 p. m. with the highest peaks at 9.00 and 11.00 a. m. 9% of deaths) (P < 0.02). When results from this study were compared to a previous study no significant difference was observed between the distribution profile of cases from general medical wards and surgical wards. CONCLUSION: It appears that in surgical patients there is a circadian pattern in pulmonary embolism as already documented in medical patients.

Aged↗
PubMed1997

[Value of peak oxygen consumption during exercise for the prognostic stratification of patients with severe systolic dysfunction of the left ventricle].

We sought to assess the prognostic value of peak exercise oxygen consumption (peak VO2) in patients with severe left ventricular systolic dysfunction and mild to moderate symptoms of chronic heart failure. We focused on 1-year mortality. We prospectively studied 77 patients with left ventricular ejection fraction (EF) < or = 25% and NYHA functional class I/II (61%) or III (39%). All patients underwent cardiopulmonary exercise test, two-dimensional echocardiography and 24-hour Holter monitoring. Examined variables were age, etiology, NYHA functional class, EF, peak VO2, and presence of nonsustained ventricular tachycardia. Overall 1-year mortality rate was 23%. At univariate analysis, age > or = 60 years, ischemic etiology, and peak VO2 < 14 ml/kg/min were significantly associated with mortality. At multivariate analysis, peak VO2 was the most powerful predictor of death (p = 0.0001). In the subgroup of patients with a peak VO2 < 14 ml/kg/min, the actuarial 1-year mortality rate was 56%. One additional patient underwent heart transplantation because of severe hemodynamic deterioration. By contrast, in the subgroup of patient with a peak VO2 > 14 ml/kg/min, 1-year mortality rate was 11%. This study provides evidence that patients with severe left ventricular dysfunction and mild to moderate symptoms of chronic heart failure can be accurately stratified into subgroups with strikingly divergent prognosis by an objective criteria such as peak VO2.

Analysis of Variance↗
PubMed1996

Muscarinic cholinergic receptor subtypes in human peripheral blood lymphocytes.

The subtypes of muscarinic cholinergic receptors were studied in human peripheral blood lymphocytes with radioligand binding techniques and the non-selective muscarinic cholinergic receptor antagonist [3H]quinuclidinyl benzylate (QNB) as a ligand. [3H]QNB was bound to human peripheral lymphocytes in a manner consistent with the labelling of muscarinic cholinergic receptors. The dissociation constant (Kd) value was 0.60 +/- 0.08 nM and the maximum density of binding sites (Bmax) was 2.33 +/- 0.03 fmol/2.2 x 10(6) cells. The binding was time-, temperature- and concentration-dependent, belonging to a single class of high affinity sites. Analysis of the pharmacological profile of [3H]QNB binding in the presence of compounds specific for the different muscarinic receptor subtypes suggests that human peripheral blood lymphocytes express mainly muscarinic cholinergic M2 and M3 receptor subtypes and to a lesser extent muscarinic M4 receptors. The characterization of the subtypes of muscarinic cholinergic recognition sites expressed by human peripheral blood lymphocytes may represent a tool for investigating the possible relationships between immune and cholinergic systems in normal and pathologic conditions.

Adult↗
PubMed1996

Pharmacological characterisation of Ca2+ channels of the L-type in human peripheral blood lymphocytes.

Ca2+ channels of the L-type were characterised in intact human peripheral blood lymphocytes using a radioligand binding technique and the dihydropyridine-type Ca2+ channel antagonist [3H](+)-PN 200-110 (isopropyl-4-(2,1,3-benzoxadiazol-4-yl)1,4-dihydro-5-methoxycarbon yl-2, 6-dimethyl-3-pyridine carboxylate) as a ligand. [3H](+)-PN 200-110 binding to human peripheral blood lymphocytes was time-, temperature-, concentration-dependent and of high affinity. The dissociation constant (Kd) value was 0.4 +/- 0.02 nM and the maximum binding capacity (Bmax) was 33.5 +/- 1.6 fmol/10(6) cells. Pharmacological analysis of [3H](+)-PN 200-110 binding to human peripheral blood lymphocytes was consistent with the labelling of a Ca2+ channel of the L-type. In fact, dihydropyridine derivatives were the most potent competitors of [3H](+)-PN 200-110 binding, whereas phenylalkylamine and benzothiazepine compounds or non-selective Ca2+ channel modulators were weak or ineffective displacers. These findings are the first observation that human peripheral blood lymphocytes express Ca2+ channels of the L-type. The possibility that Ca2+ channel antagonists may interfere with immune system function is discussed.

Adult↗
PubMed1996

Increased density of dopamine D5 receptor in peripheral blood lymphocytes of migraineurs: a marker for migraine?

The expression of dopamine D5 receptor was investigated in peripheral blood lymphocytes of 11 migraine patients and of ten healthy control subjects using a radioligand binding technique with [3H]SCH 23390 as a ligand. [3H]SCH 23390 is a benzazepine derivative with potent antagonist properties at the dopamine D1-like receptors. [3H]SCH 23390 was specifically bound to peripheral blood lymphocytes of migraineurs and control subjects in a manner consistent with the labelling of a dopamine D5 receptor. In migraineurs a statistically significant higher density of lymphocyte dopamine D5 receptor compared with controls was noticeable, whereas the affinity of the radioligand was unchanged. The increased density of dopamine D5 receptor in peripheral blood lymphocytes may reflect the dopaminergic hypersensitivity displayed by migraineurs and may represent a relatively simple and reliable peripheral marker of altered dopaminergic function.

Adult↗
PubMed1996

Muscarinic cholinergic receptor subtypes in the pigeon bursa of Fabricius: a radioligand binding and autoradiographic study.

The pharmacological profile and the anatomical localisation of muscarinic cholinergic receptor subtypes were studied in the pigeon bursa of Fabricius, using radioligand binding and autoradiographic techniques with [3H]quinuclidinyl benzilate (QNB) as a ligand. [3H]QNB was specifically bound to sections of bursa of Fabricius. The binding was time-, temperature- and concentration-dependent. The dissociation constant was 0.31 +/- 0.02 nM, and the maximum density of binding sites averaged 38 +/- 2.5 fmol/mg protein. The pharmacological profile of [3H]QNB binding to sections of pigeon bursa of Fabricius was consistent with the labelling of M2, M3 and M4 muscarinic receptor subtypes. Light microscope autoradiography showed the localisation of [3H]QNB binding sites in the medulla, in follicular septa, in the cortico-medullary border and in lesser amounts in the cortical layer. The functional significance of these receptors should be clarified in future studies.

Animals↗
PubMed1996

Prohibition of take-home dosages: negative consequences on methadone maintenance treatment.

Patients on methadone maintenance were forewarned that a law prohibiting take-home dosages was to be enforced within 6 months. At the end of the 6-month period preceding the enforcement of the law the effect of the anticipated suppression of the take-home privilege was studied on a cohort of 211 methadone-maintained patients on take-home dosages. The outcome of the treatment of these patients was compared to that of a control group of 220 patients at the end of a 6-month period prior to the announcement of the new law. The outcome of the study suggests that the restrictive regulation is counterproductive for retaining patients in treatment.

Adult↗
PubMed1996

Paget's disease of the nipple-areola complex.

The histogenesis of Paget's disease has been hotly debated, and only recently has epidermotropic theory become widely accepted. With the evolution of our understanding of breast cancer, it became apparent that the prognosis of Paget's disease was more a reflection of that of the underlying carcinoma, be it intraductal or infiltrating. The standard treatment of Paget's disease remains mastectomy with or without axillary dissection. In this era of breast-conserving surgery, however, there is much evidence to suggest that conservative treatment of Paget's disease of the breast is possible. A breast-conserving algorithm for the treatment of Paget's disease of the breast is proposed. Further refinements or modifications to the algorithm should be made as data from ongoing trials redefine our understanding of breast pathology and treatment.

Algorithms↗
PubMed1996

Age-dependent changes in the expression of dopamine receptor subtypes in human peripheral blood lymphocytes.

The pharmacological profile and the density of dopamine D3 and D5 receptor subtypes expressed by human peripheral blood lymphocytes of subjects of different ages (ranging from 20 to 75 years) were assessed using radioligand binding techniques. Dopamine D3 receptor was assayed with [3H]7-hydroxy-N,N-di-n-propyl-2-aminotetraline ([3H]7-OH-DPAT) as a ligand. Dopamine D5 receptor was assayed using [3HIR]-(+)-(-chloro-2,3,4,5, tetrahydro-5-phenyl-1H-3-benzazepin-al-hemimaleate) ([3H]SCH 23390) as a ligand. The affinity and the pharmacological profile of [3H]7-OH-DPAT and [3H]SCH 23390 at dopamine D3 and D5 receptor, respectively, were similar in subjects of different ages. The density of dopamine D3 receptor binding sites was slightly decreased in subjects of 30-39 years in comparison with younger individuals. A remarkable loss of dopamine D3 receptor was then found between 40 and 49 years of age in comparison with younger subjects. A further slight decrease was noticeable between 50 and 59 years of age. The number of [3H]7-OH-DPAT binding sites was then stabilized after 60 years of age. The density of dopamine D5 receptor binding sites did not show age-dependent changes. The above findings indicate the occurrence of a decline in the density of lymphocyte dopamine D3 but not D5 receptor between adult and mature subjects. The possibility that dopamine D3 receptor assay in peripheral blood lymphocytes may represent a tool for investigating dopamine receptor function in aging and age-related neurological disorders is discussed.

Adult↗
PubMed1996

Age-stratified incidence of unsuspected mammary carcinoma in women with fibroadenoma.

Fibroadenomas (FA) are benign neoplasms with a known albeit rare association with mammary carcinoma (MC). Incompletely explored, however, are 1) the statistical relationship of associated FA/MC with patient age and 2) the microscopic spatial relationship of associated FA/ MC. Pathology records of 1,715 patients with FA, excised over a nine-year period, were reviewed. In 59 patients concomitant diagnoses of FA and MC were rendered. In 40 of these patients MC was clinically unsuspected, signs and symptoms being attributable to the FA. Data were age stratified and slides were reviewed to identify the precise histologic association of FA and MC. Women aged 50 years and older had a statistically significant increased association of FA and MC as compared to their younger counterparts (4.1% vs 1.5%; P = .003). MC complicating FA was in situ or invasive (82.5% vs 17.5%), of ductal, lobular, or combined type (40% vs 52.5% vs 7.5%), and half of the MC were restricted to the "normal" mammary tissue surrounding the FA.

Adolescent↗
PubMed1996

[Medullary carcinoma of the thyroid].

Medullary thyroid carcinoma represents 4-8% of thyroid malignancies; regional nodal involvement is commonly found, even at the time of first surgical approach. In these patients after surgical resection, other therapeutic choices are really limited. The Authors evaluated their experience in the period 1981-1994, concerning 14 patients, 9 females and 5 males, all affected with sporadic MTC. Diagnosis was preoperative in 10 patients and intraoperative in 4; as for the staging: in 8 patients the tumor resulted confined to the thyroid, while in the remaining 6 patients it was extra-thyroidal. In 5 patients a total thyroidectomy with regional lymphadenectomy was performed, with in 6 patients a total thyroidectomy with cervico-mediastinic total lymphadenectomy was achieved. Survival was evaluated with a short, follow-up (3 months) and calculated using the K-Mayer method. Average survival was: 5 years in patients undergoing only total thyroidectomy; 3 years and 1 month in patients undergoing total thyroidectomy and lymphadenectomy; 6 months in patients undergoing no treatment at all. Among the factors negatively affecting patients survival, the Authors pointed out: metastasis occurrence; incomplete resection and mediastinal metastasis. In conclusion surgical resection (total thyroidectomy) associated with radical lymphadenectomy resulted to be a good approach. However, prognostic factors require further investigation.

Adult↗
PubMed1995

Analysis of protein-protein interactions involved in the activation of the Shc/Grb-2 pathway by the ErbB-2 kinase.

In murine fibroblasts activation of the Shc/Grb-2 pathway by the ErbB-2 kinase involves tyrosine phosphorylation of Shc products and the formation of Shc/ErbB-2, Shc/Grb-2 and Grb-2/ErbB-2 complexes. Tyr 1139 of ErbB-2 bound to the Grb-2 SH2 domain in vitro as well as in intact cells. Tyr 1221 and 1248 are binding sites of gp185ErbB-2 for Shc SH2 domain in vitro whereas Tyr 1196 and 1248 are major binding sites of ErbB-2 for Shc PTB domain. Inhibition of Shc/ErbB-2 complex formation in intact cells was obtained by simultaneous mutational inactivation of Shc SH2 and Shc PTB binding sites of gp185ErbB-2. Shc/ErbB-2 complexes are formed upon activation of the ErbB-2 kinase and tyrosine phosphorylation of Shc proteins; they are located in both cytosol and cellular membranes. ErbB-2 activation induces also translocation of Grb-2 from cytosol to membranes. This network of protein-protein interactions may reflect the ability of the Shc/Grb-2 pathway to act as a molecular switch controlling different cellular functions regulated by RTK activation. In fact the Ras GDP exchanger mSOS was recruited in Grb-2/ErbB-2 complexes; furthermore besides mSOS, other polypeptides present in either cytosolic or membrane preparations were able to complex in vitro with Grb-2 SH3 domains.

3T3 Cells↗
PubMed1995

Localisation of dopamine D3 receptor in the rat cerebellar cortex: a light microscope autoradiographic study.

The pharmacological properties and the anatomical localisation of dopamine D3 receptor were assessed in the rat cerebellar cortex using radioligand binding techniques associated with light microscope autoradiography and 7-[3H]hydroxy-N,N-di-n-propyl-2-aminotetralin (7-[3H]OH-DPAT) as a ligand. 7-[3H]OH-DPAT was specifically bound to sections of rat cerebellar cortex with a dissociation constant (Kd) of 0.5 nM and a maximum density of binding sites (Bmax) of 97 +/- 4 fmol/mg tissue. The rank order of potency of competitors of 7-[3H]OH-DPAT binding and the observation that guanosine triphosphate did not affect radioligand binding suggest the labelling of a dopamine D3 receptor. 7-[3H]OH-DPAT binding sites are located mainly in the molecular layer and in lesser amounts in the Purkinje neuron layer, primarily within the cell body of Purkinje neurons. No specific accumulation of silver grains was observed in the granule neuron layer or in the white matter of the cerebellar cortex. The localisation of a putative dopamine D3 receptor within Purkinje neurons suggests that this site may have functional relevance in the cerebellar cortex.

Animals↗