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Biomedical subjects

F Meloni

Publications and source records attributed to F Meloni.

At least 37 records · Page 2Linked to original sources
PubMed2001

Percutaneous radio-frequency ablation of hepatic metastases from colorectal cancer: long-term results in 117 patients.

PURPOSE: To describe the results of an ongoing radio-frequency (RF) ablation study in patients with hepatic metastases from colorectal carcinoma. MATERIALS AND METHODS: In 117 patients, 179 metachronous colorectal carcinoma hepatic metastases (0.9-9.6 cm in diameter) were treated with RF ablation by using 17-gauge internally cooled electrodes. Computed tomographic follow-up was performed every 4-6 months. Recurrent tumors were retreated when feasible. Time to new metastases and death for each patient and time to local recurrence for individual lesions were modeled with Kaplan-Meier analysis. Modeling determined the effect of number of metastases on the time to new metastases and death and effect of tumor size on local recurrence. RESULTS: Estimated median survival was 36 months (95% CI; 28, 52 months). Estimated 1, 2, and 3-year survival rates were 93%, 69%, and 46%, respectively. Survival was not significantly related to number of metastases treated. In 77 (66%) of 117 patients, new metastases were observed at follow-up. Estimated median time until new metastases was 12 months (95% CI; 10, 18 months). Percentages of patients with no new metastases after initial treatment at 1 and 2 years were 49% and 35%, respectively. Time to new metastases was not significantly related to number of metastases. Seventy (39%) of 179 lesions developed local recurrence after treatment. Of these, 54 were observed by 6 months and 67 by 1 year. No local recurrence was observed after 18 months. Frequency and time to local recurrence were related to lesion size (P < or =.001). CONCLUSION: RF ablation is an effective method to treat hepatic metastases from colorectal carcinoma.

Adult↗
PubMed2001

Percutaneous radio-frequency ablation of liver metastases from breast cancer: initial experience in 24 patients.

PURPOSE: To evaluate the authors' initial experience in a consecutive series of 24 patients with breast cancer liver metastases treated with radio-frequency (RF) ablation. MATERIALS AND METHODS: Twenty-four consecutive patients with 64 metastases measuring 1.0--6.6 cm in diameter (mean, 1.9 cm) underwent ultrasonography-guided percutaneous RF ablation with 18-gauge, internally cooled electrodes. Treatment was performed with the patient under conscious sedation and analgesia or general anesthesia. A single lesion was treated in 16 patients, and multiple lesions were treated in eight patients. Follow-up with serial computed tomography ranged from 4 to 44 months (mean, 10 months; median, 19 months). RESULTS: Complete necrosis was achieved in 59 (92%) of 64 lesions. Among the 59 lesions, complete necrosis required a single treatment session in 58 lesions (92%) and two treatment sessions in one lesion (2%). In 14 (58%) of 24 patients, new metastases developed during follow-up. Ten (71%) of these 14 patients developed new liver metastases. Currently, 10 (63%) of 16 patients whose lesions were initially confined to the liver are free of disease. One patient died of progressive brain metastases. No major complications occurred. Two minor complications were observed. CONCLUSION: On the basis of preliminary study results, percutaneous RF ablation appears to be a simple, safe, and effective treatment for focal liver metastases in selected patients with breast cancer.

Adult↗
PubMed2001

Effects of cardiac rehabilitation on atrial wave in patients after myocardial infarction.

Cardiac rehabilitation (CR) can improve cardiac hemodynamic performance in patients after myocardial infarction (MI). Little evidence is provided concerning the consequences of CR on atrial wave duration, and less is known about the link between pre-arrhythmogenic patterns and the cardiovascular performance improvement in these subjects. Twenty-six patients, post-MI 0 to 7 days, underwent a complete CR cycle and a signal-averaged electrocardiogram (SAECG) for the evaluation of atrial activation parameters (group 1) to appreciate if physical training can promote parallel improvement in cardiovascular and intra-atrial conduction parameters. A control group of 24 well-matched nonischemic subjects (group 2) was chosen for data comparison. Resting heart rate (p < 0.01) and resting double product (p < 0.01) decreased after CR in groups 1 and 2, while diastolic blood pressure at maximal stress was decreased in group 1 (p < 0.01) with a parallel increase in the time of physical training (p < 0.05). SAECG parameters of atrial activation were unchanged in group 1 after the comparison and only total atrial duration activation (dA) reached statistical significance (113.3 +/- 17.2 msec vs 120.8 +/- 14.2 msec, subjects after CR vs before CR, p < 0.01). CR could improve intra-atrial activation in subjects after MI, but the consequences of hemodynamic adjustment of the trained heart must undergo a more accurate evaluation to verify if CR can prevent adverse arrhythmogenic complications of MI through cardiovascular performance improvement.

Blood Pressure↗
PubMed2001

Virulence of Mycobacterium tuberculosis affects interleukin-8, monocyte chemoattractant protein-1 and interleukin-10 production by human mononuclear phagocytes.

Microbial virulence and cytokine-mediated immune responses to Mycobacterium tuberculosis infection are important determinants of the pathogenesis of human tuberculosis. To determine the interrelationship between mycobacterial virulence and cytokine induction, human monocytes and monocyte-derived macrophages were infected with attenuated (H37Ra) and virulent (H37Rv and CH306) strains of M. tuberculosis and the amount of proinflammatory [interleukin (IL)-8 and monocyte chemoattractant protein (MCP)- 1] and inhibitory (IL- 10) cytokines was measured in the culture supernatants by enzyme-linked immunosorbent assay (ELISA). Infection with live bacilli induced de novo synthesis of IL-8, MCP-1 and IL-10, since cytokine release was abolished when cells were preincubated with the protein synthesis inhibitor cycloheximide. A differential production of antiinflammatory and inhibitory cytokines was observed. The amount of IL-8 and MCP-1 release was inversely related to strain virulence, the attenuated H37Ra strain being more prone than virulent strains to induce secretion of chemokines. In contrast, virulent strains induced greater amounts of the inhibitory cytokine IL-10. Efficient upregulation of IL-10 synthesis, but not of chemokines, required infection of cells with live bacilli, since heat killing of organisms or challenge with soluble mycobacterial products completely abrogated the effect. Moreover, cells infected with virulent strains produced IL-10 even at a very low bacillus-to-cell ratio and secreted IL-10 continuously during the 96 h that followed infection. The results suggest that the degree of virulence affects host cell responses to M. tuberculosis infection. Continued production of IL-10 may be one of the means by which M. tuberculosis downregulates acute local inflammatory reactions, favoring the development of tuberculosis.

Cells, Cultured↗
PubMed2001

Removal of liver tumours using radiofrequency waves.

In the treatment of early and intermediate hepatocellular carcinoma the range of indications for percutaneous ablation techniques is becoming wider than surgery or intra-arterial therapies. Although it is understood that partial resection assures the highest local control, the survival rates after surgery are roughly comparable with those obtained with PEI or RF ablation. The explanation is due to a balance among advantages and disadvantages of the two therapies. Survival curves with percutaneous ablation techniques are better than curves of resected patients who present adverse prognostic factors, and this means that surgery needs a better selection of the patients. Indications for both of therapies are reported. An open question remains the choice among different ablation procedures. In our department we currently use RF ablation in the majority of patients but consider PEI and segmental TACE complementary, and use them according to the features of the disease and the response. In the treatment of colorectal metastases, the initial survival curves of RF ablation are promising. As treatment is size and site dependent, partial resection remains the gold standard. However, on the basis of the studies on "test of time", a possible candidate could be a patient presenting operable lesions with favourable criteria for a complete ablation. An interesting indication seems to be the treatment of breast liver metastases in selected patients.

Carcinoma, Hepatocellular↗
PubMed2000

MEKC of desmosine and isodesmosine in urine of chronic destructive lung disease patients.

Degradation of extracellular matrix components is central to many pathological features of chronic destructive lung disorders. Desmosine and isodesmosine are elastin-derived cross-linked amino acids whose urine levels are considered representative of elastin breakdown. The aim of this study was to apply a novel methodology, based on high-performance capillary electrophoresis, to the quantification of desmosine and isodesmosine in 11 patients with stable chronic obstructive pulmonary disease (COPD), 10 with an exacerbation of COPD, nine with alpha1-antitrypsin deficiency, 13 with bronchiectasis, and 11 adults with cystic fibrosis, in comparison to 24 controls. It was found that, in patients with stable COPD, urinary desmosine levels were higher than in controls (p=0.03), but lower than in COPD subjects with an exacerbation (p< or =0.05). The highest desmosine levels were found in subjects with alpha1-antitrypsin deficiency, bronchiectasis and cystic fibrosis (p<0.001 versus stable COPD). In a short-term longitudinal study, five stable COPD patients showed a constant rate of desmosine excretion (mean coefficient of variation <8% over three consecutive days). In conclusion, the present method is simple and suitable for the determination of elastin-derived cross-linked amino acid excretion in urine, giving results similar to those obtained using other separation methods. In addition, evidence is presented that urinary desmosine excretion is increased in conditions characterized by airway inflammation, such as exacerbations of chronic obstructive pulmonary disease, bronchiectasis and cystic fibrosis. Results obtained in subjects with alphal-antitrypsin deficiency suggest that this method might be used to evaluate the putative efficacy of replacement therapy.

Adult↗
PubMed2000

Hepatocellular carcinoma: radio-frequency ablation of medium and large lesions.

PURPOSE: To study local therapeutic efficacy, side effects, and complications of radio-frequency (RF) ablation in the treatment of medium and large hepatocellular carcinoma (HCC) lesions in patients with cirrhosis or chronic hepatitis. MATERIALS AND METHODS: One-hundred fourteen patients who were under conscious sedation or general anesthesia had 126 HCCs greater than 3.0 cm in diameter treated with RF by using an internally cooled electrode. Eighty tumors were medium (3.1-5.0 cm), and 46 were large (5.1-9.5 cm). The mean diameter for all tumors was 5.4 cm. At imaging, 75 tumors were considered noninfiltrating, and 51 were considered infiltrating. RESULTS: Complete necrosis was attained in 60 lesions (47.6%), nearly complete (90%-99%) necrosis in 40 lesions (31.7%), and partial (50%-89%) necrosis in the remaining 26 lesions (20.6%). Medium and/or noninfiltrating tumors were treated successfully significantly more often than large and/or infiltrating tumors. Two major complications (death, hemorrhage requiring laparotomy) and five minor complications (self-limited hemorrhage, persistent pain) were observed. The single death was due to a break in sterile technique rather than to the RF procedure itself. CONCLUSION: RF ablation appears to be an effective, safe, and relatively simple procedure for the treatment of medium and large HCCs.

Aged↗
PubMed2000

Different pathways of degradation of SP-A and saturated phosphatidylcholine by alveolar macrophages.

Alveolar macrophages degrade surfactant protein (SP) A and saturated phosphatidycholine [dipalmitoylphosphatidylcholine (DPPC)]. To clarify this process, using rabbit alveolar macrophages, we analyzed the effect of drugs known to affect phagocytosis, pinocytosis, clathrin-mediated uptake, caveolae, the cytoskeleton, lysosomal pH, protein kinase C, and phosphatidylinositol 3-kinase (PI3K) on the degradation of SP-A and DPPC. We found the following: 1) SP-A binds to the plasma membrane, is rapidly internalized, and then moves toward degradative compartments. Uptake could be clathrin mediated, whereas phagocytosis, pinocytosis, or the use of caveolae are less likely. An intact cytoskeleton and an acidic milieu are necessary for the degradation of SP-A. 2) Stimulation of protein kinase C increases the degradation of SP-A. 3) PI3K influences the degradation of SP-A by regulating both the speed of internalization and subsequent intracellular steps, but its inhibition does not prevent SP-A from reaching the lysosomal compartment. 4) The degradation of DPPC is unaffected by most of the treatments able to influence the degradation of SP-A. Thus it appears that DPPC is degraded by alveolar macrophages through mechanisms very different from those utilized for the degradation of SP-A.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1999

Small hepatocellular carcinoma: treatment with radio-frequency ablation versus ethanol injection.

PURPOSE: To compare the effectiveness of radio-frequency (RF) ablation with that of percutaneous ethanol injection in the treatment of small hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Eighty-six patients with 112 small (< or = 3-cm-diameter) HCCs underwent RF ablation (42 patients with 52 tumors) or percutaneous ethanol injection (44 patients with 60 tumors). Therapeutic efficacy was evaluated with dual-phase spiral computed tomography performed at least 4 months after treatment. RESULTS: Complete necrosis was achieved in 47 of 52 tumors with RF ablation (90%) and in 48 of 60 tumors with percutaneous ethanol injection (80%). These results were obtained with an average of 1.2 sessions per tumor with RF ablation and 4.8 sessions per tumor with percutaneous ethanol injection. One major complication (hemothorax that required drainage) and four minor complications (intraperitoneal bleeding, hemobilia, pleural effusion, cholecystitis) occurred in patients treated with RF ablation; no complications occurred in patients treated with percutaneous ethanol injection. CONCLUSION: RF ablation results in a higher rate of complete necrosis and requires fewer treatment sessions than percutaneous ethanol injection. However, the complication rate is higher with RF ablation than with percutaneous ethanol injection. RF ablation is the treatment of choice for most patients with HCC.

Aged↗
PubMed1999

Small hepatocellular carcinoma treated with percutaneous RF ablation: MR imaging follow-up.

OBJECTIVE: The purpose of our study was to determine the usefulness of MR imaging in the follow-up evaluation of small hepatocellular carcinoma lesions treated with RF ablation. SUBJECTS AND METHODS: The study group included 37 patients with a single hepatocellular carcinoma lesion less than 3 cm in diameter. A strict protocol required follow-up MR imaging every 6 months after RF treatment. At each follow-up visit, the findings on unenhanced and dynamic gadolinium-enhanced MR images were correlated with those on contrast-enhanced CT images and with results of fine-needle aspiration biopsy. In five patients who underwent surgical resection after the 6-month follow-up examination, comparison with histologic findings of surgical specimens was also performed. RESULTS: Correct diagnosis of complete or partial tumor necrosis was made in 32 (86%) of the 37 patients with the use of unenhanced and dynamic gadolinium-enhanced MR images. Hypointensity on T2-weighted images and loss of enhancement on dynamic MR images corresponded to completely necrotic lesions in all patients. Conversely, intratumoral regions of hyperintensity on T2-weighted images and enhancement on dynamic MR images did not always correlate to residual viable tumor. MR imaging and CT findings agreed in the evaluation of therapeutic response in all patients. CONCLUSION: Our experience confirms that MR imaging is useful for evaluating the effectiveness of RF therapy in achieving tumor regression.

Aged↗
PubMed1998

Long term results of single session percutaneous ethanol injection in patients with large hepatocellular carcinoma.

BACKGROUND: The objective of this study was to evaluate the indications for percutaneous ethanol injection (PEI) performed in a single session under general anesthesia for treating patients with cirrhosis and large (tumors > 5 cm) hepatocellular carcinoma (HCC), and relevant survival curves. METHODS: Between November 1991 and November 1996, 108 patients were treated (a total of 128 procedures). They fell into 3 groups: 24 patients with single, encapsulated HCC measuring from 5-8.5 cm (Group A); 63 patients with single, infiltrating HCC measuring from 5-10 cm or multiple HCC (Group B); and 21 patients with advanced disease, either hepatic (Child's Class C) or neoplastic (symptomatic HCC or with portal thrombosis) type (Group C). The mean amount of ethanol injected was 62 mL. The average hospital stay was 3.8 days. The mean follow-up time was 40 months. RESULTS: The 1-, 2-, 3-, and 4-year survival rates were: 72%, 65%, 57%, and 44%, respectively, for Group A; 73%, 60%, 42%, and 18%, respectively, for Group B; and 46%, 25%, and 0%, respectively, for Group C. Mortality was 0.7% (bleeding from esophageal varices in a Child's Class C patient). The rate of major complications was 4.6% (1 case of peritoneal hemorrhage, 1 case of severe liver failure, 1 case of transient renal insufficiency, 1 case of peritoneal seeding, and 2 cases of infarctions of a segment adjacent to the tumor). CONCLUSIONS: Single session PEI has been proven to be a valid alternative in patients otherwise treated surgically or with transcatheter arterial chemoembolization who present with adverse prognostic factors or risks for these therapies, and may be an option for selected patients with advanced disease previously excluded from any therapy. Risk conditions are marked portal or pulmonary hypertension or esophageal varices at risk of bleeding, superficial tumors with severe coagulation disorders, hyperfibrinolysis, chronic renal insufficiency, and obstructive jaundice.

Administration, Cutaneous↗
PubMed1998

Urinary levels of bombesin-related peptides in a population sample from northern Italy: potential role in the pathogenesis of chronic obstructive pulmonary disease.

Bombesin-related peptides (BRP) are present in the lung and have various biological functions, including modulation of lung maturation. Many recent studies have suggested that BRP have a pathogenic role in airway wall remodeling in chronic obstructive pulmonary disease. The aim of this cross-sectional survey was to evaluate the distribution of urinary BRP excretion as a indirect marker of pulmonary BRP production and to assess the prevalence of smoking, chronic respiratory symptoms, chronic obstructive pulmonary disease, and asthma in a population sample from northern Italy. Associations between urinary BRP excretion and several respiratory and nonrespiratory variables were also evaluated. The only variable tested that was significantly predictive of high urinary levels of BRP was the presence of respiratory symptoms. In contrast to previous studies, smoking per se was not significantly associated with urinary BRP levels.

Adolescent↗
PubMed1998

Bombesin, calcium homeostasis and tumour growth.

Bombesin and its analogues are a family of naturally occurring neuropeptides with potent mitogenic activity. The ability of this agent to induce Ca2+ transients is likely to be relevant in this context, but it is not yet clear whether the effect of bombesin on cell growth is directly and exclusively related to its capacity to increase cytoplasmic Ca2+ levels. The present study investigates the affect of bombesin on cytoplasmic Ca2+ concentrations in human tumour cells of different origin: lung adenocarcinoma, lung adenocarcinoma with properties of alveolar epithelial cells (A549 cell line), mesothelioma and uterine carcinoma (HeLa cell line). Furthermore, the ability of bombesin to promote the in vitro growth of the same cells has been analysed. This agent was able to induce a transient rise in cytoplasmic Ca2+ levels in tumour cells from all lines. In lung adenocarcinoma cells, but not in the other tumour cells, bombesin produced Ca2+ transients followed by a moderate but sustained elevation of Ca2+ levels. The effects of bombesin on tumour cell cytoplasmic Ca2+ levels were compared to those of other agents, i.e. adenosine diphosphate (ADP), collagen or thrombin, which have been reported to induce Ca2+ transients in tumour cells. Bombesin and ADP increased cytoplasmic Ca2+ levels in all cell lines, while collagen and thrombin gave rise to higher transients, but were effective only in some tumour cells and not in others. Furthermore, bombesin was able to stimulate in vitro growth of all the tumour cells, except for the A549 cells, in which this agent induced a slightly lower increase in cytoplasmic Ca2+ concentration. These data may aid a better understanding of the complex relationship between the Ca2+ mobilizing and mitogenic activities of bombesin and may be of general interest when considering the biological effects of growth-stimulating factors.

Bombesin↗
PubMed1997

Saline-enhanced radio-frequency tissue ablation in the treatment of liver metastases.

PURPOSE: To assess the effect of intraparenchymal saline injection on the results of radio-frequency (RF) tissue ablation. MATERIALS AND METHODS: Ex vivo and in vivo animal RF ablation was performed with and without intraparenchymal saline injection. Initially, saline was injected as a bolus (1-20 mL) before RF application. For subsequent in vivo studies, saline was injected as a bolus before RF application or continuously (1 mL/min) during RF application. Finally, 14 patients with liver metastases and one patient with primary cholangiocarcinoma were treated with the continuous infusion technique. A single RF electrode (tip exposure, 1-3 cm) was used with various ablation parameters. RESULTS: With pretreatment bolus injection of saline, lesions measured 1.4 cm +/- 0.1, 1.6 cm +/- 0.2, and 1.2 cm +/- 0.1 in ex vivo liver, in vivo animal muscle, and in vivo animal liver, respectively. Without saline enhancement, lesion sizes were 1.0 +/- 0.2, 1.2 +/- 0.2, and 0.8 +/- 0.1 cm, respectively. With continuous saline injection in in vivo pig liver, lesion size was 1.8 - 4.1 cm in diameter. In human tumors, necrosis volume was variable, but complete necrosis was seen in 13 of 25 lesions (diameter, 1.2-3.9 cm). Partial necrosis greater than 50% was seen in 12 lesions (diameter, 1.5-4.5 cm). CONCLUSION: Saline-enhanced RF ablation might permit percutaneous destruction of large liver lesions.

Adult↗
PubMed1997

Hepatic metastases: percutaneous radio-frequency ablation with cooled-tip electrodes.

PURPOSE: To assess the feasibility and safety of using cooled-tip electrodes to increase the volume of coagulation necrosis obtained or reduce the number of treatment sessions necessary with percutaneous tumor radio-frequency (RF) ablation. MATERIALS AND METHODS: Twenty-nine patients with 44 hepatic metastases (1.3-5.1 cm diameter) from colorectal (n = 22), gastric (n = 5), pancreatic (n = 1), or breast (n = 1) carcinoma were treated with RF ablation using cooled-tip, 18-gauge electrodes with 2-3 cm tip exposure. Each tumor was treated in one or two treatment sessions. RESULTS: Technical success, ablation of all visualized tumor, was achieved in 40 (91%) metastases. Findings at computed tomography (CT) and magnetic resonance (MR) imaging performed 3-6 months after treatment confirmed complete necrosis of the entire metastasis in 66%. Disease-free survival was 50% at 12 months and 33% at 18 months, with localized progression of disease in 34% of treated lesions. Overall survival was 100%, 94%, and 89% at 6, 12, and 18 months, respectively. Only one complication, self-limited hemorrhage, was seen. CONCLUSION: Use of cooled-tip electrodes was a safe and feasible adjunct for tumor RF ablation therapy that produced larger volumes of coagulation necrosis with fewer electrode insertions than is produced with other RF ablation techniques.

Aged↗
PubMed1997

Computerised tomography evaluation of the frontal recess in inflammatory diseases of the frontal sinus: standardisation of a new technique.

The authors present a new investigation technique by means of CT of the frontal sinus drainage pathway, the frontal recess, which could be of considerable help in defining its potential role in determining a chronic or recurrent inflammatory process of this cavity. Among the main characteristics of this technique are: (1) a clear presentation of the course and conformation of the recess and its relations with surrounding structures; (2) speedy, and therefore economical, operation (12 min for a complete examination); and (3) tolerability, because this examination starts off with axial-scans, which, compared to CT coronal projections and MRI scans, are less prone to defects and do not require strained postures. This this means that all kinds of patients can be assessed, which is a basic requirement for achieving standardisation. With axial scans the authors work from paraxial reconstructions (oblique sagittal) which, in their opinion, give the best definition of the frontal recess so far recorded.

Adult↗