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Biomedical subjects

F Ricci

Publications and source records attributed to F Ricci.

At least 37 records · Page 2Linked to original sources
PubMed2004

Adrenomedullin immunoreactivity tissue distribution in parathyroids of the patients with primary hyperparathyroidism.

Adrenomedullin (ADM) is a new potent vasorelaxant peptide identified originally in extracts of pheochromocytoma, and is widely distributed within the tissue. Although histopathological studies have demonstrated the presence of ADM-immunoreactivity (ir-ADM) in some human neuroendocrine tumors (such as insulinoma, pituitary adenoma, and gastrointestinal neuroendocrine tumors), data on the presence of ADM in normal and pathological parathyroid gland are not available. Plasma AM concentrations were recently reported to be elevated in patients with PHP (primary hyperparathyroidism). The aim of our study was to determine tissue distribution of ir-AM in 34 patients with PHP (27 female and 7 male, mean age 50 +/- 6 years) undergoing surgery. Six normal parathyroid samples incidentally found during thyroidectomy for neoplastic diseases and ten sections of human rectus abdominis muscle tissue were used as controls (C). Adenomatous parathyroids were found in 22 PHP and hyperplastic parathyroids in twelve PHP patients. Four hyperplastic parathyroids were found in three PHP patients and three parathyroids in 10 PHP patients. Eight parathyroids revealed a prevalent diffuse growth pattern and four showed a prevalent nodular growth pattern. Immunohistochemical ADM expression was seen in seven of twelve (58.3 %) hyperplastic parathyroids and in fourteen of twenty-two (66.6 %) adenomatous glands. Parathyroid chief cells showed strong cytoplasmatic staining, whereas oncocytic cells showed a faintly aspecific cytoplasmatic staining. Normal parathyroids were negative for ir-ADM. In conclusion, we found the presence of ADM in parathyroid chief cells of PHP patients using immunohistochemistry in our study.

Adenoma↗
PubMed2004

The GABAB agonist baclofen blocks the expression of sensitisation to the locomotor stimulant effect of amphetamine.

The purpose of the present study was to test the possible influence of baclofen, a GABAB agonist, on the long-term sensitisation to amphetamine in rats. As expected, chronic amphetamine treatment (1.5 mg/kg i.p. daily for 10 days) led to an increased locomotor response to amphetamine (0.75 mg/kg i.p.), when the animals were challenged 20 days after the end of repeated treatment. Baclofen (2 mg/kg i.p.), administered before the test session, did not significantly modify the spontaneous locomotor activity of rats, but decreased the normal and, to a greater extent, the sensitised locomotor response to amphetamine; thus baclofen prevented the expression of sensitisation to amphetamine. Moreover a previous chronic treatment with baclofen (2 mg/kg i.p. daily for 10 days) attenuated the amphetamine-induced locomotor activity in sensitised, but not in control animals. This effect was observed 20 days after the last baclofen administration. In conclusion, the present results demonstrate that GABAB receptors play an important role in the expression of the sensitised behavioural response to amphetamine and further support a potential role of GABAB agonists in the treatment of psychostimulant addiction.

Amphetamine↗
PubMed2004

Expression of CTLA-4 in nonhuman primate lymphocytes and its use as a potential target for specific immunotoxin-mediated apoptosis: results of in vitro studies.

T-cell-mediated immunoregulation is one of the main mechanisms implicated in induction and maintenance of transplantation tolerance. In this regard, deletion or modulation of xeno/alloantigen-specific T cells, as well as blocking of their interactions with other cell populations, are currently being pursued for tolerance induction in humans as well as nonhuman primates. In order to investigate whether cytotoxic T-lymphocyte antigen-4 (CTLA-4) may represent a suitable target for a T cell depletion approach in nonhuman primate models, we analysed CTLA-4 expression in peripheral blood mononuclear cells (PBMCs) from nonhuman primates and the potential role of two anti-CTLA-4 saporin-conjugated immunotoxins. The analysis was performed in PBMCs from 8 cynomolgus monkeys from Philippines and from Mauritius both at protein level by flow cytometry and at transcriptional level by RT-PCR. In addition, the apoptotic role of the immunotoxins was investigated. The results showed that CTLA-4 was expressed at variable levels depending on the origin of the cynomolgus monkeys and the resting or activated cell condition. CTLA-4 was not expressed on resting Mauritius PBMCs and showed a lower up-regulation upon PMA/PHA activation compared to the Philippines PBMCs that expressed CTLA-4 also before activation. Two CTLA-4 RNA transcripts (672 and 550 bp) were detected with levels variations after cell stimulation. Two anti-CTLA-4 immunotoxins induced in vitro apoptosis of activated PBMCs from both sources of cynomolgus monkeys. This is the first report that documents CTLA-4 expression both at protein and transcriptional level by nonhuman primate PBMCs and provides novel perspectives of xeno/allograft rejection immunotherapy based on CTLA-4 targeting.

Animals↗
PubMed2004

Microgravity-induced alterations in cultured testicular cells.

Cultured STe cells (2n karyotype) from swine testis were submitted to simulated microgravity using a 3D Random Positioning Machine for 5 min., 15 min., 30 min., 1 h and 23 h. Sample processing included: histological characterization of cell types, immunohistochemical identification of (i) microtubules (a-tubulin), (ii) alkaline phosphates, (iii) 3 beta-hydroxy-steroid-dehydrogenase (3?-HSDH), and histochemical lipid analyses. After 5 min. simulated microgravity a slight microtubule disorganisation occurred, which increased dramatically with increasing microgravity duration. After 23 h microtubule arrays were completely disrupted. 3 beta-HSDH immunostaining was detectable only in one cell type: under control conditions and 5 min. into microgravity immunoreactivity was strong, but completely disappeared thereafter. Immunostaining intensity for alkaline phosphates, a good marker for myoid cells, decreased after 15 min. in microgravity.

3-Hydroxysteroid Dehydrogenases↗
PubMed2003

Prussian Blue based screen printed biosensors with improved characteristics of long-term lifetime and pH stability.

The promising advantages of Prussian Blue (PB) as catalyst and of the thick film screen printing technology have been combined to assemble sensors with improved characteristics for the amperometric determination of H(2)O(2). PB-modified screen printed electrodes were applied to detect H(2)O(2) at an applied potential of -0.05 V versus the internal screen printed Ag pseudoreference electrode, showing a detection limit of 10(-7) mol l(-1), a linearity range from 10(-7) to 5x10(-5) mol l(-1), a sensitivity of 234 microA mmol l(-1) cm(-2), and a high selectivity. Improved stability at alkaline pH values was also observed, which made possible their use with enzymes having an optimum basic pH. Then, the immobilisation of a single enzyme (glucose oxidase (GOD) or choline oxidase (ChOX)) or of two enzymes, acetylcholinesterase (AchE) coimmobilised with ChOX, has been performed on the surface of PB modified screen-printed electrodes (SPEs) using glutaraldehyde and Nafion. ChOX has been selected as an example of enzyme working at alkaline pH. The choline biosensors showed a detection limit of 5x10(-7) mol l(-1), a wide linearity range (5x10(-7)-10(-4) mol l(-1)), a high selectivity and a remarkable long term stability of 9 months at 4 degrees C, and at least 4 weeks at room temperature. Similar analytical characteristics and stability were observed with the acetylcholine biosensors.

Biosensing Techniques↗
PubMed2003

Flow cytometry characterization of white cell-reduced blood: apoptosis markers and morphology of postfiltration elements.

BACKGROUND AND OBJECTIVES: Apoptosis affects white blood cells (WBCs) contained in packed red blood cell (RBC) units. This phenomenon was recently described also in residual WBCs after filtration. The aim of this study was to better characterize the residual WBCs postfiltration by using apoptosis markers and morphology. MATERIALS AND METHODS: Immunofluorescence, flow cytometry and cell-sorting techniques were utilized. RESULTS: Residual leucocytes of leucodepleted packed RBC units showed increasing values of apoptotic elements in a time-course experiment. We also demonstrated that these elements are positive for APO 2.7 monoclonal antibody (mAb), poly ADP-ribose polymerase (PARP) cleavage and fluorescein isothiocyanate (FITC)-conjugated N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD-FMK), all of which indicate that programmed death is a feature of this population of cells. Phenotypic analysis with CD45 side-scatter gating demonstrated also that CD15 and CD16 granulocyte-associated antigens are present on a subset of postfiltration leucocytes. Moreover, the expression of human leucocyte antigen (HLA) class I antigens is maintained. Sorting of CD45-positive cells and morphological analysis of these samples confirmed that leucocytes in postfiltration units have morphological characteristics of dying cells. CONCLUSIONS: Our study extends previous observations regarding the morphology and function of apoptotic cells in leucodepleted blood units, which suggested the presence of apoptotic cells in postfiltration leucocytes. Cleaved PARP, APO 2.7 mAb and positivity for the FITC-conjugated Z-VAD-analogous reagent strongly suggest the activation of programmed death pathways. In addition, the maintained granulocyte-associated and HLA class I antigens might recall an immune response in multitransfused patients.

Apoptosis↗
PubMed2003

Two twins with teratoma of the ovary. An unusual association: case report.

Teratomas are neoplasms composed of tissue foreign to the area in which it is found. They are considered to be an acquired neoplastic disease and familial incidence has not been reported. Only one occurrence of teratoma between monozygotic twins has been found in the literature. Here we report the case of two heterozygotic twins with benign cystic teratomas of the ovary as a base for future research for efficacy of an accurate familial follow-up in order to diagnose this neoplasm in early stage and for the molecular understanding of pathogenesis of teratoma.

Adult↗
PubMed2003

[Radiological examination of the Lap-Band for the treatment of severe obesity].

The aim of this study is to determine the role of radiographic assessment in patient who underwent an adjustable laparoscopic (or laparotomic) banding for the treatment of morbid obesity, and to evaluate the different type of postoperative complications. Forty-three consecutive patients with morbid obesity were examined before and after surgical treatment with positioning of Lap-Band. In all patients radiological examination permitted to evaluate the bend position, the dimensions of the gastric pouch and of the stoma. In such cases it was possible to modify the stoma dimensions under fluoroscopy. 74.4% of patients obtained satisfactory weight loss without complications. In 16.2% of patients the treatment was unsatisfactory and the radiological examination demonstrated the presence and the type of complications. In 9.3% of patients the radiological exam was negative for complications but they didn't obtain satisfactory weight loss. Radiographic assessments are crucial in the management of weight loss and detection of postoperative complications in this surgical treatment.

Adult↗
PubMed2002

Intrinsic d-wave effects in YBa(2)Cu(3)O(7-delta) grain boundary Josephson junctions.

We have measured the angular dependence of the Josephson critical current density (J(C)) in c-axis tilt biepitaxial grain boundary YBa(2)Cu(3)O(7-delta) junctions. We observe for the first time intrinsic d-wave pairing symmetry effects manifested as an oscillatory dependence of J(C) on angle. This intrinsic effect is evident even though spontaneous currents, possibly induced by faceting or barrier impurities, are observed in the grain boundaries.

Journal Article↗
PubMed2002

Cognitive and affective disorders associated to HIV infection in the HAART era: findings from the NeuroICONA study. Cognitive impairment and depression in HIV/AIDS. The NeuroICONA study.

OBJECTIVE: To assess the natural story of HIV-associated affective and cognitive disorders and the relationship with clinical, pharmacological, immunological and behavioural factors. METHOD: A total of 395 HIV-positive patients, naive to Highly Active Antirectroviral therapy (HAART), with no severe psychiatric disorders have been enrolled in the Neuro-ICONA Study. All participants were administered a comprehensive data collection instrument including an addiction behaviour survey, a medical problem list, a psychiatric assessment, a validated neuropsychological test battery. RESULTS: The global prevalence of cognitive impairment and of prominent depressive symptomatology were 17.9 and 15.5%, respectively. A significant difference in the prevalence of prominent depressive symptomatology was observed between patients in HAART and those not taking HAART(14.1 vs. 23.8%; P = 0.05). CONCLUSION: Depressive and cognitive disorders affect a substantial proportion of HIV-seropositive subjects. The prevalence of prominent depressive symptomatology appears to significantly vary in relationship to the therapeutic protocol.

Adult↗
PubMed2002

Heparin-induced thrombocytopenia: detection of antiheparin/PF4 antibodies by means of heparin/PF4-coated beads and flow cytometry.

A total of 70 serum samples from heparin-induced thrombocytopenia (HIT II) patients, non-HIT patients and healthy subjects, respectively, were studied for the presence of antiheparin/PF4 antibodies. Two enzyme-linked immunosorbent assay (ELISA) assays were compared with the particle gel immunoassay (PaGIA). Beads of the PaGIA kit were also used to evaluate the feasibility of flow cytometric detection of antiheparin/PF4 antibodies in patient samples. Experiments have shown that all samples found positive by ELISA and PaGIA, were also positive when analysed by flow cytometry by an indirect test using the high-density particles coated with heparin/PF4 complexes and a second step fluorescein isothiocyanate (FITC) antihuman immunoglobulin (Ig)G reagent. The procedure was easy to perform, repetitive and beads were promptly visualized by physical parameters, with a very low background. In conclusion, the results of this study suggest that flow cytometry is a reliable method for the detection of antiheparin/PF4 antibodies.

Adult↗
PubMed2002

Giant diverticulum of the sigmoid colon with perforation. Report of a case.

We present a case of perforated giant diverticulum of the sigmoid colon. This condition is extremely rare and only a few cases have so far been reported in the literature. Our case involved a 55-year old woman. Diagnosis was easy with barium enema and CT scan examination. Laparotomy revealed a giant diverticulum of the sigmoid colon compressing adjacent structures with signs of inflammation. An en bloc resection of the sigmoid colon, ovary and fallopian tube was performed with primary colon-rectal anastomosis. The post-operative course was uneventful.

Diverticulum, Colon↗
PubMed2002

Monodermal highly specialized teratoma of the ovary: a sebaceous gland tumor.

Teratomas are neoplasms that originate in pluripotential cells and contain representations of all three germ layers in a rather mature state. Specialized forms of teratoma with unilateral development of certain tissues, such as struma ovarii, argentaffin tumors, cholesteatoma, primary choriocarcinoma of the ovary, pseudomucinous cystoma and neurogenic cysts are known. In this paper we describe an ovarian teratoma consisting entirely of sebaceous glands.

Adult↗
PubMed2001

Comparison between different laboratory tests for the detection and prevention of heparin-induced thrombocytopenia.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a possible complication of heparin therapy that can evolve with life-threatening thromboembolism, for which early diagnosis is essential. However, the specific laboratory approach to the diagnosis of HIT is still controversial. METHODS: Sera from 13 patients with HIT, from 15 patients with non-HIT thrombocytopenia, and from 10 normal subjects were used to compare nonfunctional and functional methods to detect anti-heparin:PF-4 antibodies and platelet activation. We used three enzyme-linked immunosorbent assays (ELISAs) and the particle gel immunoassay as nonfunctional tests, and platelet aggregometry, CD62p (p-selectin) phenotypical expression, and Annexin V binding as functional assays. RESULTS: CD62p expression was positive in 85% of the cases and Annexin V was positive in 40% of the HIT cases examined. Aggregometry gave variable results that depend strongly on the donor. CONCLUSION: Functional tests for platelet activation are more reliable for HIT diagnosis than the nonfunctional tests. We conclude that the phenotypical expression of p-selectin detected by flow cytometry on activated platelets appears to be a good functional marker for the diagnosis of HIT and its possible thromboembolic complications.

Adult↗
PubMed2001

Interleukin-11 induces Th2 polarization of human CD4(+) T cells.

Exploration of the immunomodulatory activities of the multifunctional cytokine interleukin-11 (IL-11) has prompted several therapeutic applications. The immunomodulatory effects of IL-11 on human antigen-presenting cells and on T cells were investigated. IL-11 inhibited IL-12 production by activated CD14(+) monocytes, but not by mature dendritic cells (DCs) stimulated via CD40 ligation. Moreover, IL-11 did not affect either DC maturation, as demonstrated by phenotypic analysis and evaluation of cytokine production, or DC generation from progenitor cells in the presence of specific growth factors. Molecular analysis demonstrated the expression of IL-11 receptor messenger RNA in highly purified CD14(+) monocytes, CD19(+) B cells, CD8(+), and CD4(+) T cells, and CD4(+)CD45RA(+) naive T lymphocytes. In keeping with this finding, IL-11 directly prevented Th1 polarization of highly purified CD4(+)CD45RA(+) naive T cells stimulated with anti-CD3/CD28 antibodies, as demonstrated by significant increases of IL-4 and IL-5, by significantly decreased interferon-gamma production and by flow cytometry intracellular staining of cytokines. Coincubation of naive T cells with DCs, the most potent stimulators of Th1 differentiation, did not revert IL-11-mediated Th2 polarization. Furthermore, parallel experiments demonstrated that the activity of IL-11 was comparable with that induced by IL-4, the most effective Th2-polarizing cytokine. Taken together, these findings show that IL-11 inhibits Th1 polarization by exerting a direct effect on human T lymphocytes and by reducing IL-12 production by macrophages. Conversely, IL-11 does not exert any activity on DCs. This suggests that IL-11 could have therapeutic potential for diseases where Th1 responses play a dominant pathogenic role.

Adjuvants, Immunologic↗
PubMed2001

Chronic fatigue syndrome following a toxic exposure.

Chronic fatigue syndrome (CFS) is a clinical entity characterized by severe fatigue lasting more than 6 months and other well-defined symptoms. Even though in most CFS cases the etiology is still unknown, sometimes the mode of presentation of the illness implicates the exposure to chemical and/or food toxins as precipitating factors: ciguatera poisoning, sick building syndrome, Gulf War syndrome, exposure to organochlorine pesticides, etc. In the National Reference Center for CFS Study at the Department of Infectious Diseases of 'G. D'Annunzio' University (Chieti) we examined five patients (three females and two males, mean age: 37.5 years) who developed the clinical features of CFS several months after the exposure to environmental toxic factors: ciguatera poisoning in two cases, and exposure to solvents in the other three cases. These patients were compared and contrasted with two sex- and age-matched subgroups of CFS patients without any history of exposure to toxins: the first subgroup consisted of patients with CFS onset following an EBV infection (post-infectious CFS), and the second of patients with a concurrent diagnosis of major depression. All subjects were investigated by clinical examination, neurophysiological and immunologic studies, and neuroendocrine tests. Patients exposed to toxic factors had disturbances of hypothalamic function similar to those in controls and, above all, showed more severe dysfunction of the immune system with an abnormal CD4/CD8 ratio, and in three of such cases with decreased levels of NK cells (CD56+). These findings may help in understanding the pathogenetic mechanisms involved in CFS.

Adult↗
PubMed2001

Octyl 2-cyanoacrylate tissue adhesive in experimental scleral buckling.

PURPOSE: In this experimental study, a sutureless scleral buckling was performed by using a tissue adhesive glue to fixate a silicone band to the sclera. In fact, one of the major risks of traditional scleral buckling is accidental perforation of the bulb, which is more frequent when the sclera is extremely thin as it is in newborns or in eyes with high myopia or scleromalacia. METHODS: An encircling band of silicone, which is generally anchored to the sclera itself, was sutured in 36 rabbit eyes to three small silastic patches that had been glued to the sclera, at the level of the equator, using octyl 2-cyanoacrylate tissue adhesive. In this manner the anchoring sutures passed through silicone and silicone. The band was tightened to produce buckling of the sclera and its ends were glued together using the same adhesive. RESULTS: Examination of the eyes from 15 days to 6 months after surgery revealed that the buckle was stable, with no signs of slippage, in 33 eyes. In the remaining 3 (one examined after 15 days, 2 examined after 45 days), one of the three support patches had become detached but there was still no evidence of slippage. CONCLUSIONS: The stability of the buckle up to six months after surgery suggests that this new adhesive might be used for sutureless surgery in certain types of retinal detachment, such as that associated with stage 4 ROP in which the encircling band has to be removed after several months.

Animals↗