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Biomedical subjects

A Agazzi

Publications and source records attributed to A Agazzi.

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

The prevalence and clinical implications of c-kit expression in plasma cell myeloma.

AIM: To evaluate the clinical implications of c-kit (CD117) expression in plasma cell myeloma (PCM). METHODS AND RESULTS: We first evaluated the reliability of immunohistochemistry in assessing c-kit expression by comparing the results with those obtained by flow cytometry and gene expression arrays in 22 PCM and in 10 PCM cell lines. Immunohistochemical results showed a perfect concordance with those of flow cytometry; likewise, immunohistochemical and gene expression data were also concordant in all but one PCM and cell lines analysed. Then, we investigated the clinical implications of c-kit immunoreactivity in bone marrow biopsies of 85 PCM patients with a mean follow-up of 41 months. C-kit immunoreactivity was detected in 24 (28.2%) of the 85 cases and it was significantly associated with a high microvessel density, but not with traditional clinicopathological characteristics or with survival. CONCLUSIONS: Our findings suggest that immunohistochemistry is a reliable indicator of c-kit gene expression and reinforce the notion that approximately one-third of PCM express high levels of c-kit. The lack of association with traditional clinicopathological parameters and patient survival suggests that c-kit expression may not be an adjunct in predicting the clinical course of the disease.

Adult↗
PubMed2005

Identification of galanin receptor 1 on excitatory motor neurons in the guinea pig ileum.

Exogenously administered galanin inhibits cholinergic transmission to the longitudinal muscle and reduces peristaltic efficiency in the guinea pig ileum with a mechanism partially mediated by galanin receptor 1 (GAL-R1). We investigated the effect of exogenous galanin 1-16, which has high affinity for GAL-R1, on the ascending excitatory reflex of the circular muscle elicited by radial distension in isolated segments of guinea pig ileum. We used a three-compartment bath that allows dissecting the ascending pathway into the oral (site of excitatory motor neurons), intermediate (site of ascending interneurons) and caudal compartment (site of intrinsic primary afferent neurons). Galanin 1-16 (0.3-3 micromol L(-1)) applied to the oral compartment inhibited in a concentration-dependent manner the ascending excitatory reflex elicited by the wall distension in the caudal compartment. This effect was antagonized by the GAL-R1 antagonist, RWJ-57408 (1 and 10 micromol L(-1)). By contrast, galanin 1-16 was ineffective when added to the intermediate or caudal compartment up to 3 micromol L(-1). GAL-R1 immunoreactive neurons did not contain neuron-specific nuclear protein, a marker for intrinsic primary afferent neurons. These findings indicate that GAL-R1s are present on motor neurons responsible for the ascending excitatory reflex, but not on ascending interneurons and intrinsic primary afferent neurons.

Animals↗
PubMed2004

Use of totally implantable central venous access ports for high-dose chemotherapy and peripheral blood stem cell transplantation: results of a monocentre series of 376 patients.

BACKGROUND: The complication rate of central venous totally implantable access ports (TIAP), used for high-dose chemotherapy with autologous stem cell transplantation support, has not been fully investigated to date, due to the almost exclusive use of externalised, tunnelled devices in this clinical setting. PATIENTS AND METHODS: During a 66-month period (from 1 January 1997 to 30 June 2002), 376 patients suffering from breast cancer, ovarian cancer, lymphoma or multiple myeloma were treated with high-dose chemotherapy and autologous stem cell transplantation at the European Institute of Oncology (Milan, Italy). A single type of port was used, constructed from titanium and silicone rubber, connected to a 7.8 F polyurethane catheter (Port-A-Cath; SIMS Deltec, Inc., St Paul, MN, USA) inserted into the subclavian vein. They were followed prospectively for device-related complications until the device was removed, the patient died or the study was closed (30 June 2002). RESULTS: No TIAP-related deaths were observed in this series. Seven pneumothoraxes (1.8%) occurred as a complication of TIAP placement, one patient only (0.2%) requiring a tube thoracostomy. Port pocket infection occurred twice in this series (0.53%, 0.01 episodes/1000 days of use), whereas three patients suffered from port-related bacteraemia (0.8%, 0.016/1000 days of use). Infections were successfully treated with antibiotics; all three cases had the ports removed at programme completion. Four cases of deep vein thrombosis were detected (1.06%, 0.022/1000 days of use); low molecular weight heparin was given, followed by oral anticoagulants. Finally, one case of extravasation occurred (0.26%, 0.005/1000 days of use), requiring port removal and local medical therapy. CONCLUSIONS: The use of TIAPs has resulted in a safe and effective option for high-dose chemotherapy deliverance and stem cell transplantation, in spite of inducing severe neutropenia and increasing the risk of sepsis in this category of oncology patient.

Adult↗
PubMed2004

Role of galanin receptor 1 in gastric motility in rat.

Galanin actions are mediated by distinct galanin receptors (GAL-R), GAL-R1, -R2 and -R3. We investigated the role of GAL-R1 in gastric motility and the expression of GAL-R1 in the rat stomach. In vivo, in urethane-anaesthetized rats, galanin (equipotent for all GAL-Rs) induced a short inhibition of gastric motility, followed by increase in tonic and phasic gastric motility; the latter was significantly reduced by the GAL-R1 antagonist, RWJ-57408. Galanin 1-16 (high affinity for GAL-R1 and -R2) induced a long-lasting decrease of intragastric pressure, which was not modified by RWJ-57408. In vitro, galanin and galanin 1-16 induced increase of intragastric pressure that was not affected by RWJ-57408. Tetrodotoxin (TTX) did not suppress the galanin excitatory effect, whereas the effect of galanin 1-16 on gastric contraction was increased by TTX- or N-nitro-L-arginine, an inhibitor of nitric oxide synthase. GAL-R1 immunoreactivity was localized to cholinergic and tachykinergic neurons and to neurons immunoreactive for nitric oxide synthase or vasoactive intestinal polypeptide. This study suggests that an extrinsic GAL-R1 pathway mediates the galanin excitatory action, whereas an extrinsic, non GAL-R1 pathway is likely to mediate the galanin inhibitory effect in vivo. GAL-R1 intrinsic neurons do not appear to play a major role in the control of gastric motility.

Animals↗
PubMed2003

Review of the implications of dietary tryptophan intake in patients with irritable bowel syndrome and psychiatric disorders.

In this review, we address the possible role of the essential amino acid L-tryptophan or its metabolic derivative 5-hydroxytryptophan in the modulation of serotonin (5-hydroxytryptamine) synthesis and thereby in affecting the pathophysiology of central and peripheral nervous system disorders, including depression and irritable bowel syndrome. L-Tryptophan may represent a link between apparently disparate functional disorders and is of interest for general gastroenterologists, neurogastroenterologists, and neurologists. On the basis of estimates showing that approximately 20% of patients with functional bowel disorders seeking care in referral centres have psychiatric comorbidity, we attempt to provide a conceptual framework for defining the possible role of L-tryptophan in this population.

5-Hydroxytryptophan↗
PubMed2003

Idarubicin containing regimen in multiple myeloma: preliminary results of a pilot study using a modified "TANDEM" transplant program.

Tandem autologous transplant actually represents a challenge in multiple myeloma treatment, but the best conditioning regimen is still under investigation. With the aim of evaluating the feasibility of a modified tandem transplant strategy, we treated 10 multiple myeloma patients after conventional first line chemotherapy with a two step conditioning regimen consisting of high-dose melphalan (200 mg/m2) followed by high-dose melphalan (180 mg/m2) together with indarubicin (15 mg/sqm2 c.i. x 3 days) both with peripheral stem cell support. At first transplant, the median age wasyears, performance status was good and disease status was CR in 2 patients and PR in the rest. At the end of the first transplant, 70% of patients achieved CR and only mild toxicity was observed. After the second transplant further improvement of the response rate was obtained with 90% CR. However, we observed three toxic early infection-related deaths from CMV and legionella pneumonia at day + 17, +26, +54 after transplantation. Although this schedule seems to be effective in terms of response rate, the 30% TRM imposes an anthracycline dose-reduction with careful patient selection. This approach could reduce the toxic effects and maintain the efficacy of therapy at the same time.

Aged↗
PubMed2000

Evaluation of acute toxicities associated with autologous peripheral blood progenitor cell reinfusion in patients undergoing high-dose chemotherapy.

Peripheral blood progenitor cell reinfusion (PBPC) in patients undergoing high-dose chemotherapy (HDC) for poor prognosis malignancies, has been described as causing possible acute gastrointestinal (nausea, vomiting), allergic (oedema, bronchospasm, anaphyl- axis), renal (proteinuria, haematuria) and/or cardiovascular (hypotension, arrhythmia, conduction disturbances, transient ischaemic phenomena) toxicities. To establish the clinical relevance of these observations and the possible relationship with different HDC regimens used, we performed a clinical and instrumental evaluation on 33 patients with advanced breast cancer, non-Hodgkin's lymphoma, Hodgkin's disease, relapsed ovarian cancer, Ewing's sarcoma, extragonadal germinal tumour and small cell lung cancer. They underwent at least one reinfusion each for a total of 51 studied procedures. No patient had a previous history of cardiovascular disease or significant intercurrent illness such as diabetes or liver, renal or neurologic impairment. All patients had totally implanted central venous catheters, through which the transplants had been collected and reinfused without technical consequences. To evaluate cardiovascular function, we continuously monitored 12-lead ECGs, with arterial pressure (AP) measurements every 5 min from the beginning of the procedure to 15 min after the reinfusion ended. We did not observe any significant differences between basal and subsequent steps in AP, heart rate, PQ and QTc time, P wave and QRS complex duration or P wave and QRS electrical axes. No patient showed any ST-T tract pathological abnormality, but one patient developed a transient ectopic atrial rhythm, without any haemodynamic disfunction and with spontaneous reversion to sinus rhythm. No patient complained of symptoms of haemodynamic failure. Gastrointestinal side-effects appeared to be strictly related to speed of reinfusion and to the number of packs reinfused, probably reflecting on the amount of dimethylsulphoxide infused. In one patient a tonic-clonic seizure occurred during a vomiting episode, but no patient developed allergic or renal toxicities. We conclude that PBPC reinfusion, if managed according to the procedure we propose in patients without organic impairment, is a safe procedure not associated either with increased risk of acute arrhythmias or ischaemic or significant systemic acute toxicities. Bone Marrow Transplantation (2000) 25, 173-177.

Adult↗
PubMed1999

Angiogenic growth factors and endostatin in non-Hodgkin's lymphoma.

A number of clinical studies have demonstrated the prognostic significance of angiogenesis and angiogenic growth factors in solid tumours; however, very little is known about the relevance of these parameters in haematological malignancies. We evaluated circulating levels of angiogenic growth factors and endostatin in 36 non-Hodgkin's lymphoma (NHL) patients. Baseline vascular endothelial growth factor (VEGF) levels of patients in complete remission (CR) after a median follow-up of 21 months were significantly lower than those of patients with progressive disease (P = 0.016). Event-free survival (EFS) rate was significantly higher in patients who had baseline VEGF and basic-fibroblast growth factor (b.FGF) levels below the median values of 147 and 19.5 pg/ml (P = 0.018 and 0.039 by log-rank test, respectively). Conversely, the levels of endostatin, angiogenin and leptin were not different in CR patients compared to relapsed patients and did not correlate with EFS. Our data suggest that b-FGF and, particularly, VEGF might be considered prognostic factors in NHL staging and management.

Adult↗
PubMed1998

Optimisation of a stentless valve prosthesis based on an analytic parametric model of the aortic valve.

An analytical mathematical model of a stentless aortic valve has been implemented. The valve is characterised by a trileaflet geometry, cylindrical leaflets; the aortic root is schematised by a conical surface which includes the leaflet attachments. The model is defined through six geometric parameters: the base radius, the valve height, the commissure radius, the leaflet radial, circumferential and attachment line lengths. Five performance indexes have been used to optimise the valve geometry, namely: the systolic area, the leaflet circumferential stress in diastole, the leaflet bending strain in systole and two bending angles related to the rotation of the leaflets from the diastolic to the systolic configuration. The sensitivity analysis is carried out which can identify the influence of each geometric parameter on the performance indexes adopted for the optimum valve design. The analysis of the results provides the geometric configuration which optimises the overall function of the valve throughout the cardiac cycle.

Aortic Valve↗
PubMed1995

A recombination event in the closely linked plasminogen and apolipoprotein(a) gene loci.

Genetic studies as well as in situ hybridisation data have strongly demonstrated that the genes coding for apoprotein(a) and plasminogen are linked and localised to chromosome 6 at band 6q26-27. We describe in this report the presence of a recombination event in a region of approximately 50 kb of DNA separating the two genes. The recombination was found in an Italian family, in which a mutation affecting both plasminogen plasma level and activity of plasminogen activity has been detected. Polymerase chain reaction and sequencing analysis showed the presence of a mutation different from those previously reported in two Japanese families.

Adult↗
PubMed1994

Protein S and protein C anticoagulant activity in acute and chronic cardiac ischemic syndromes. Relationship to inflammation, complement activation and in vivo thrombin activity.

Protein S (PS) and protein C (PC) anticoagulant activities and thrombin-antithrombin complex (TAT) were measured in 20 patients with AIS, 25 patients with chronic stable angina (CSA) and a control group (C). Although plasma levels of TAT were significantly elevated in patients with CSA (p < 0.01 vs C), they were much higher in patients with AIS (p < 0.001 vs CSA). PC anticoagulant activity was similar in patients and controls. At variance, PS anticoagulant activity was lower in patients with AIS than in those with CSA and controls (p < 0.05), reflecting differences in total PS and C4B-binding protein (C4B-BP) antigen possibly resulting from involvement in the mechanisms of inflammation, complement activation and acute-phase response. The ratios of anticoagulant PS and PC to procoagulant vitamin K-dependent factors IX and II were reduced in AIS patients (0.05 > p > 0.005 vs C). In addition, the ratios of anticoagulant PC and PS to factor IX were lower in patients with AIS than in those with CSA (p < 0.05). These results indicate that in patients with acute ischemic cardiac syndromes the markedly increased in vivo thrombin generation is associated with an unbalance between coagulant and anticoagulant vitamin K-dependent factors.

Acute Disease↗