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Biomedical subjects

M Sacchi

Publications and source records attributed to M Sacchi.

At least 19 recordsLinked to original sources
PubMed2006

Role of carbon monoxide in electrically induced non-adrenergic, non-cholinergic relaxations in the guinea-pig isolated whole trachea.

BACKGROUND AND PURPOSE: Nitric oxide (NO) and vasoactive intestinal peptide (VIP) are considered transmitters of non-adrenergic, non-cholinergic (NANC) relaxations in guinea-pig trachea, whereas the role of carbon monoxide (CO) is unknown. This study was designed to assess the participation of CO, and to investigate the localization of haem oxygenase-2 (HO-2), the CO-producing enzyme, in tracheal neurons. EXPERIMENTAL APPROACH: NANC responses to electrical field stimulation (EFS) at 3 and 10 Hz were evaluated in epithelium-free whole tracheal segments as intraluminal pressure changes. Drugs used were: L-nitroarginine methyl ester (L-NAME, 100 microM) to inhibit NO synthase (NOS), alpha-chymotrypsin (2 U ml(-1)) to inactivate VIP, zinc protoporphyrin-IX (ZnPP-IX, 10 microM) to inhibit HO-2, and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10 microM), a soluble guanylyl cyclase inhibitor. For immunohistochemistry, tissues were exposed to antibodies to PGP 9.5, a general neuronal marker, HO-2 and NOS, and processed with an indirect immunofluorescence method. KEY RESULTS: alpha-Chymotrypsin did not affect NANC relaxations. ODQ inhibited NANC responses by about 60%, a value similar to that obtained by combining L-NAME and ZnPP-IX. The combination of ODQ, L-NAME and ZnPP-IX reduced the responses by 90%. Subpopulations of HO-2 positive neurons containing NOS were detected in tracheal sections. CONCLUSIONS AND IMPLICATIONS: In the guinea-pig trachea, NANC inhibitory responses at 3 and 10 Hz use NO and CO as main transmitters. Their participation is revealed following inhibition of NOS, HO-2 and soluble guanylyl cyclase. The involvement of CO as a relaxing transmitter paves the way for novel therapeutic approaches in the treatment of airway obstruction.

Animals↗
PubMed2006

Coherent peaks and minimal probing depth in photoemission spectroscopy of Mott-Hubbard systems.

We have measured hard x-ray photoemission spectra of pure vanadium sesquioxide (V(2)O(3)) across its metal-insulator transition. We show that, in the metallic phase, a clear correlation exists between the shakedown satellites observed in the vanadium 2p and 3p core-level spectra and the coherent peak measured at the Fermi level. Comparing experimental results and dynamical mean-field theory calculations, we estimate the Hubbard energy U in V(2)O(3) (4.20+/-0.05 eV). From our bulk-sensitive photoemission spectra we infer the existence of a critical probing depth for investigating electronic properties in strongly correlated solids.

Journal Article↗
PubMed2006

[Appendiceal mucocele due to mucinous cystadenoma: case report and review of the literature].

Mucinous cystadenomas of the appendix are rare tumours. In this article we describe the case of a young woman who presented with abdominal pain and a clinical pattern likely to a chronic appendicitis. At laparotomy we found a dilatation of the appendix which contained an abundant quantity of mucus. Histological examination showed a mucinous cystadenoma of the appendix. This neoplasm requires a surgical treatment, usually only appendectomy and right hemicolectomy in case of involvement of the caecum. During operation, the surgeon must take care in handling the appendix because of the risk of rupture with consequent dissemination of epithelial cells in the peritoneal cavity (pseudomyxoma peritonei).

Appendectomy↗
PubMed2005

Intra-abdominal inflammatory myofibroblastic pseudotumor: case report and review of the literature.

Inflammatory myofibroblastic pseudotumors (IPM) are very rare tumor characterized by unpredictable clinical behaviour. They arise in soft tissues of almost every organ and the most common site is the lung. Over 200 cases of inflammatory myofibroblastic pseudotumor of the lung have been described in literature. Intra-abdominal IMP are very rare. We describe a case of intra-abdominal IMP in a boy of 15 years old who presented symptoms and signs of acute appendicitis. Exploratory laparotomy revealed a mass in the peritoneal cavity. The mass was removed. The histologic examination showed that it was an IMP. Surgical treatment was the only therapy. Six months after the surgical operation the patient has no sign of illness.

Adolescent↗
PubMed2000

SB7: the new bending-magnet double-headed dragon beamline at SuperACO.

A new beamline is now operational at LURE on bending-magnet 7 of the SuperACO storage ring in Orsay. The monochromator is of the ;dragon' type, designed to work in the energy range 150-1500 eV, and is equipped with a double vertical focusing mirror in order to allow for fast switching of light polarization. In this paper the results of photoion-yield experiments performed on N(2), Ar and Ne gases are presented. The observed resonance structures enable us to determine the available energy resolution: a resolving power higher than 8500 is obtained at the Ar 2p, N 1s and Ne K-edges when using all the optical elements at full aperture. The total flux as a function of the measured photon energy resolution and the characterization of the double-head behaviour in delivering circularly polarized light are reported.

Journal Article↗
PubMed1999

[Klatskin tumor. A study of 15 resected cases].

STUDY AIM: Klatskin tumors are rare. Prognosis is still poor, and long term survival can be expected only after surgery, which is the treatment of choice. The aim of this study is to report the results of 15 resected cases and, by analysis of the literature, to emphasize the progress of the surgical treatment in hilar cholangiocarcinoma. PATIENTS AND METHODS: Between 1990 and 1998, 27 patients affected by Klatskin tumor were observed. Eight women and seven men underwent surgical resection. The mean age was 59 years. Thirteen patients (48%) had curative resection (7 hilar resection (HR), 5 HR combined with partial hepatectomy (PH) and 1 HR + PH with portal vein resection). Two patients had palliative resection and surgical drainage. RESULTS: One in-hospital death occurred right after hepatectomy with portal vein resection (6.6%). Postoperative morbidity was 40%. Patients were regularly followed. Ten patients died and 5 were alive at the time of this study. The 1, 2 and 3-year survival after a curative resection was 84%, 54% and 34%. The median survival was 28.5 months. Lymph node involvement did not show a statistically significant difference on median survival between the positive group and the negative group (26.2 vs 29.8 months) because of the small number of patients. Survival after hilar resection at 1, 2, 3, and 5 years was 100%, 57.1%, 28.6% and 0%. Four out of the 6 patients who underwent hilar resection combined with partial hepatectomy were still alive 1, 23, 29, 38 months after resection. Hepatectomy increased mortality (16% vs 0%). Palliative biliary resection and surgical drainage were successfully performed in 2 patients. CONCLUSION: Aggressive surgical treatment of Klatskin tumor can improve the survival of patients. Careful pre-operative management has to be carried out by a multidisciplinary approach including surgeons, hepatologists, radiologists and pathologists. Hepatic resection including the caudate lobe is often performed in order to obtain microscopic tumor-free margins and curative resection (R0). Biliary drainage and treatment of cholangitis is mandatory before surgery in order to improve the surgical outcome. Surgical treatment is characterized by high technical difficulties, and better results can be achieved by hepatobiliary surgical teams.

Adult↗
PubMed1999

Pancreatic resections: early results and functional behaviour of the stapled pancreatic stump.

Pancreaticoduodenectomy is the standard surgical treatment for patients with pancreatic head cancer. Morbidity and mortality rates following this procedure have constantly decreased over the past several years. Leakage of the pancreaticoenteric anastomosis is one of the most serious complications, often responsible for a fatal outcome. Several methods for the management of the pancreatic stump have been described in order to reduce the worrisome incidence of this complication, with variable results. In this series, the Authors review their experience of 75 pancreatic resections and analyze the early results and functional behaviour of 6 patients in which the pancreatic stump was stapled without pancreaticoenteric anastomosis.

Adenocarcinoma↗
PubMed1995

Integrin expression in head and neck cancers.

Neoplastic transformation results in rearrangement of the cell membrane with a breakdown of the regular expression of adhesion molecules such as integrins. A relationship may exist between the intensity of this alteration, and the form it takes, and a tumour's ability to metastatise. We studied this possibility by investigating the epithelial integrin expression of 35 head and neck squamous cell carcinomas. Two types of positivity were observed: one associated with tumours with a better prognostic index, the other with those characterized by greater malignancy.

Carcinoma, Squamous Cell↗
PubMed1992

Receptors for interleukin 2 on human squamous cell carcinoma cell lines and tumor in situ.

Several human head and neck squamous carcinoma cell lines were found to bind 125I-labeled or fluorescein-labeled interleukin 2 (IL-2). This binding was inhibited by an excess of cold ligand, IL-2, and by anti-p55 and anti-p70 monoclonal antibodies to the alpha and beta chains, respectively, of the IL-2 receptor (IL-2R). A small number (300/cell) of high-affinity IL-2R (2 x 10(-12) M) and a larger number (> 13,000/cells) of intermediate-affinity IL-2R (3 x 10(-10) M) were present on these tumor cells. By affinity cross-linking, tumor cells were shown to bind 125I-IL-2 to a M(r) 66,000 and 55,000 doublet peptide. The alpha and beta chains of the IL-2R also were detected on the surface of cultured tumor cells using the relevant monoclonal antibodies and flow cytometry. Immunoperoxidase staining with anti-p70 monoclonal antibody confirmed the expression of IL-2R on squamous cell carcinomas of the head and neck in situ. The presence of transcripts for p55/IL-2R-alpha and p70/IL-2R-beta in PCI-1 cells was confirmed by the polymerase chain reaction followed by hybridization to the IL-2R-alpha complementary DNA probe or IL-2R-beta complementary DNA probe, respectively. Our observations demonstrate that intermediate-affinity and high-affinity IL-2Rs are expressed on some human squamous cell carcinomas of the head and neck and that the receptors are functional, because growth of these tumor cell lines can be directly inhibited by exogenously supplied IL-2. The presence of IL-2R on human solid tumors could be important to consider, in addition to immunomodulatory effects of IL-2, in developing optimal therapeutic strategies for the administration of IL-2 to patients with cancer.

Antibodies, Monoclonal↗
PubMed1992

Interleukin 2 receptors on squamous cell carcinomas of the head and neck. Characterization and functional role.

IL2Rs, in the presence of IL2, mediate activation and proliferation of human normal lymphocytes and modulate functional changes of some human leukocytic malignancies. IL2Rs have been demonstrated also on human neoplastic and fetal non-hematologic cells in vitro, although their functional role has not been described. We describe the presence of high affinity IL2Rs on squamous cell carcinoma of the head and neck (SCCHN) lines in vitro. Expression of 200 binding sites for IL2 with an affinity of 17 x 10(-12) was demonstrated by radiobinding experiments. When cytocentrifuged SCCHN cells were studied by immunoperoxidase staining, strong positive staining was repeatedly obtained using a monoclonal antibody to the p70 subunit of the IL2Rs. Experiments in vitro and in vivo, in a nude mouse model, showed a functional role for these receptors. In fact, low doses (8-500 U/ml) of IL2 were able to inhibit growth of 11 of the 16 SCCHN lines tested. Our observations may have broad implications for the immunotherapy of cancer in general, showing the complementary immunomodulatory and direct effects of IL2.

Carcinoma, Squamous Cell↗