Search

A Working Group coordinated by the Italian National Institute of Health (Istituto Superiore di Sanita) and the National Workers Compensation Authority (Istituto Nazionale per l’Assicurazione contro gli Infortuni sul Lavoro, INAIL) and consisting of 11 Italian scientific/professional societies involved in the fluoroscopically guided interventional practices has been established to define recommendations for the optimization of patients and staff radiation protection in interventional radiology. A summary of these recommendations is here reported. A multidisciplinary approach was used to establish the Working Group by involving radiologists, interventional radiologists, neuroradiologists, interventional cardiologists, occupational health specialists, medical physicists, radiation protection experts, radiographers and nurses. The Group operated as a “Consensus Conference”. Three main topics have been addressed: patient radiation protection (summarized in ten “golden rules”); staff radiation protection (summarized in ten “golden rules”); and education/training of interventional radiology professionals. In the “golden rules”, practical and operational recommendations were provided to help the professionals in optimizing dose delivered to patients and reducing their own exposure. Operative indications dealt also with continuing education and training, and recommendations on professional accreditation and certification. The “Consensus Conference” was the methodology adopted for the development of these recommendations. Involvement of all professionals is a winning approach to improve practical implementation of the recommendations, thus getting a real impact on the optimization of the interventional radiology practices.

Allo scopo di fornire un quadro di massima dei vantaggi e dei problemi connessi alla utilizzazione di modelli numerici per la valutazione della circolazione indotta dal moto ondoso in presenza di opere di difesa dei litorali tracimabili, successivamente ad una descrizione dei processi fisici in gioco, viene presentata una rassegna degli approcci modellistici possibili e dei principali metodi di risoluzione delle corrispondenti equazioni. Al fine di evidenziare i campi di applicabilità della modellistica a scopi progettuali ed i relativi limiti, vengono illustrati i risultati delle simulazioni numeriche di un caso test schematico, di prove di laboratorio eseguite in condizioni ben controllate e di due casi di studio reali. I modelli testati forniscono distribuzioni delle correnti e del livello medio in accordo generale con le misure. Discrepanze osservabili fra soluzioni numeriche e misure sono ascrivibili principalmente alla rappresentazione del frangimento, della turbolenza, della tracimazione, dell’interazione onda-corrente e degli effetti tridimensionali. L’importanza di poter disporre di dati di campo affidabili nelle applicazioni pratiche è evidenziata dalla necessità di accurata calibrazione e validazione dei modelli numerici per una migliore risposta quantitativa. Tuttavia, la capacità dei modelli numerici esistenti di riprodurre le caratteristiche salienti dei processi fisici di interesse tecnico li rende comunque uno strumento di analisi prezioso a scopi progettuali anche in assenza di misure dirette, se utilizzati con criterio.

Objective: To verify whether the in vitro sensitivity of immature dendritic cells (iDC) to lysis by autologous natural killer (NK) cells from HIV-infected individuals might be correlated with HIV disease progression. Design: Both dendritic cells (DC) and interlekin (IL)-2 activated NK cells were obtained from 13 HIV-infected individuals early after seroconversion and not receiving highly active antiretroviral therapy (HAART) and from 14 individuals with chronic HIV infection under HAART The rate of NK cell-mediated killing of autologous iDC was correlated with classical parameters of HIV evolution. Methods: Peripheral blood monocytes obtained from the Ficoll-derived leukocyte fraction after adherence to plastic were stimulated with granulocyte-macrophage colony stimulating factor plus IL-4 to induce their differentiation into iDC to be used as target cells in a standard 4-h cytotoxicity assay. A fraction of autologous leukocytes was stimulated with IL-2 to induce activation of NK cells to be used as effector cells. Results: During early HIV infection the extent of ex vivo lysis of monocyte-derived DC by activated autologous NK cells was inversely and directly correlated with the levels of viraemia and with the percentage of circulating CD4 T cells, respectively. In contrast, the capacity of NK cells to kill iDC was lost independently of the levels of plasma viraemia or the concurrence of HAART in chronically infected individuals. Addition of exogenous HIV Tat during the cytotoxicity assay inhibited NK cell-mediated lysis of DC. Conclusions: NK cell-mediated immune surveillance against infected DC may be effective only during early HIV infection and may not be restored by HAART. (C) 2003 Lippincott Williams Wilkins.

HIV-infected individuals with 200-500 CD4(+) T cell/mul were enrolled in a controlled study of three interleukin 2 (IL-2) plus antiretroviral therapy (ART) regimens: (1) continuous intravenous administration of 12 million international units (MIU) of IL-2 followed by subcutaneous high-dose IL-2 (7.5 MIU, twice daily) for 5 days every 8 weeks; (2) high-dose subcutaneous IL-2 for 5 days every 8 weeks; (3) low-dose (3 MIU, twice daily) subcutaneous IL-2 for 5 days every 4 weeks; and (4) ART alone. Serum concentrations of IL-2, soluble IL-2 receptor (sIL-2R), tumor necrosis factor alpha (TNF-alpha), and IL-6 were determined. A progressive decrease over time of the circulating levels of IL-2 was observed in individuals receiving the highest doses of IL-2, but not in those belonging to the low-dose arm. Conversely, increased levels of sIL-2R were observed in all cytokine-treated individuals. The levels of TNF-alpha increased in the high-dose IL-2 regimens, but decreased in individuals receiving low-dose IL-2. IL-2-related toxicity was significantly correlated to the peak IL-2 serum levels, and was substantially lower in those individuals receiving low-dose IL-2. In conclusion, intermittent IL-2 administration causes the elevation of peripheral CD4(+) T cells, but also a profound cytokine response and systemic toxicity. The latter was correlated to the peak serum level of IL-2, but not to those of TNF-alpha and IL-6.

Plasma free fatty acids and intramyocellular triglycerides (IMCL) content modulate whole body insulin sensitivity in humans. To test whether the interactions between fatty acid metabolism and insulin action in nonobese humans are related to gender factors, we studied 15 young, normal weight, healthy men and 15 women matched for life habits and whole body insulin sensitivity, determined with the euglycemic-hyperinsulinemic clamp, by means of indirect calorimetry to assess substrate oxidation, localized (1)H nuclear magnetic resonance spectroscopy of calf muscles to assess IMCL content, and dual energy x-ray absorption to assess body composition. In addition, to test whether perturbation of the feminine hormonal milieu modifies these interactions, we studied 15 matched females using oral steroidal contraception (OSC). Insulin sensitivity in women, notwithstanding increased body fatness, plasma free fatty acids, IMCL content, and circulating beta-hydroxybutyrate levels and reduced lipid oxidation, was similar to that in men. Women using OSC showed a 40% reduction of insulin sensitivity associated with increased plasma free fatty acids, beta-hydroxybutyrate, cholesterol, and triglycerides levels and a slight increment in IMCL content compared with women with intact hormonal cycles. In all groups the IMCL content was inversely related to insulin sensitivity. In conclusion, nonobese, healthy, young women are as insulin sensitive as men, notwithstanding the higher levels of postabsorptive circulating and tissue-stored fatty acids; OSC-induced insulin resistance is associated with abnormal fatty acid metabolism and loss of this gender-related feature.

Because dendritic cells (DC) play a major role in the initiation of T cell-mediated immunity, we studied the effects of glucocorticoids, well-known inhibitors of the immune and inflammatory response, on the differentiation and maturation of human DC. DC were differentiated from human monocytes by culture with GM-CSF and IL-4 for 7 days with and without dexamethasone (Dex). Cells treated with Dex (10−8 M) (Dex-DC) developed a characteristic dendritic morphology; however, membrane phenotype analysis demonstrated that they were not fully differentiated. Dex-DC expressed low levels of CD1a and, unlike untreated cells, high levels of CD14 and CD16. Molecules involved in Ag presentation (CD40, CD86, CD54) were also impaired. In contrast, molecules involved in Ag uptake (mannose receptor, CD32) and cell adhesion (CD11/CD18, CD54) were up-regulated. After exposure to TNF-α or CD40 ligand, Dex-DC expressed lower levels of CD83 and CD86 than untreated cells. Dex-DC showed a higher endocytic activity, a lower APC function, and a lower capacity to secrete cytokines than untreated cells. Overall, these results indicate that DC differentiated in the presence of Dex are at a more immature stage. Moreover, Dex also partially blocked terminal maturation of already differentiated DC. In conclusion, our data suggest that glucocorticoids may act at the very first step of the immune response by modulating DC differentiation, maturation, and function.

Since the clinical earliest descriptions of patients with acquired immune deficiency syndrome (AIDS) it has been very clear that a profound state of immunologic dysfunction was the underlying cause of the emergence of life-threatening opportunistic infections and tumors. In addition to the progressive loss of CD4 "helper" T lymphocytes, a profound defect in interleukin-2 (IL-2) production was recognized as a major pathogenic component of the new disease. For these reasons, attempts to administer IL-2 to individuals infected with the human immunodeficiency virus (HIV), the causative agent of AIDS, have been made since the mid eighties, however with little success. On the other hand, the propensity of HIV to replicate in activated lymphocytes and macrophages, under the influence of the cytokine network, has represented, and in part still does, a major hurdle for the rationale of administering IL-2 or other cytokines to HIV-infected individuals. Major steps forward towards an understanding of the role of multiple components of the immune system, coupled with a potentially successful protocol of IL-2 administration in vivo, resulting in the stable uprising of circulating CD4+ T cells, shed an optimistic light on the possibility to achieve a substantial immune reconstitution in HIV-infected individuals, thus preventing the onset of AIDS.

Myotonic distrophy (MyD), the most common adult form of muscular dystrophy, is often complicated by diabetes. MyD is dominantly inherited and is due to heterozygosity for a tri-nucleotide repeat expansion mutation in a protein kinase gene which was suggested to induce derangement of RNA metabolism able to reduce insulin receptor expression. To test whether the abnormal RNA metabolism or a specific malfunction of protein kinase gene induces defective energy metabolism and insuline resistance prior to the onset of diabetes, we studied 10 MyD patients (2 glucose intolerant) and 10 matched healthy subjects, by means of (a) dual X-ray energy absorption, (b) euglycemic-hyperinsulinemic clamp ( 1 mU/Kg/min) combined with primed-continuous infusion of [6,6-d2]-glucose and [1-13C]-leucine, (c) indirect calorimetry, and (d) oral glucose tolerance test (OGTT) to explore insulin-dependent glucose, lipid and protein metabolism. MyD reduced Jean body mass (LBM: 36 ± 3 vs 46 ± 3 Kg; P < 0.02) and increased fat mass. Nevertheless, resting energy expenditure (33.4 ± 0.9 vs 33.8 ± 1.5 kcal/kg/day; P = 0.83), insulin-stimulated glucose metabolism [7.22 ± 0.22 vs 8.48 ± 0.80 mg/(kg LBM · min); P = 0.49], and lipid metabolism in the postabsortive and clamp conditions were comparable to normals. Proinsulin concentrations were increased in MyD patients (P = 0.01) and the intact proinsulin/insulin ratio (23 ± 4 vs 10 ± 1%; P < 0.01) was twofold higher in MyD. Circulating proinsulin levels also failed to be normally regulated during suppressing (clamp) or stimulating (OGTT) conditions. Markers of proteolysis (ELF: endogenous leucine flux) in the postabsorptive [203 ± 15 vs 146 ± 9 μmol/(kg LBM · h); P < 0.02] and insulin-stimulated conditions (ELF suppression during the insulin clamp: 11 ± 3 vs 18 ± 2%; P < 0.05) were higher in MyD than in normals and they were associated to reduced plasma insulin-like growth factor (IGF-1: 125 ± 18 vs 212 ± 8 ng/ml; P < 0.03) and increased plasma α-tumor necrosis factor receptor-2 (TNFR-2: 1919 ± 212 vs 1401 ± 172 pg/ml, P = 0.04). In summary, in MyD, energy metabolism was preserved but the severe loss of LBM was associated with abnormal postabsorptive and insulin-stimulated regulation of protein breakdown. Insulin resistance with respect to glucose metabolism was lacking, and a higher risk to develop type 2 diabetes is more likely due to abnormal insulin secretion. The combination of reduced circulating IGF-1 levels and increased TNF system activity may be responsible for the increased protein breakdown which is involved in muscle wasting in MyD

Evaluation of the performance of different HCV PCR detection systems for HCV RNA: A nested PCR, considered the reference assay, was compared with two single-step methods (ss-PCR): the first is based on the detection of PCR products by liquid hybridization with a 32P end-labelled probe (isotopic ss-PCR), while the second assay is a colorimetric method (colorimetric ss-PCR) using microwell plate hybridization with a specific nucleic acid probe (Amplicor HCV PCR, Roche Diagnostics Systems).Sera from 56 patients with suspected hepatitis C infection based on reactive serology or altered liver parameters, and sera from 15 blood donors were tested for HCV RNA: After RNA extraction, the synthesized HCV cDNA was amplified in parallel using isotopic ss-PCR, colorimetric ss-PCR and nested PCR. The products were detected by autoradiography, color development and ethidium bromide fluorescence, respectively.In order to assess the analytical sensitivity of ss-PCR versus that of nested of PCR, experiments included serial dilutions of positive control samples. Results showed that both methods had an extinction signal at the 1:512 dilution. A comparative analysis of 71 clinical sera samples was obtained using the three protocols and the results clearly documented 100% concordance.Single step PCR methods for HCV RNA have a sensitivity equal to that of nested PCR and appear more suitable for diagnostic applications. Ss-PCR is safer than nested PCR in terms of both specificity and contamination problems. In particular, the Roche Amplicor HCV PCR assay minimizes sample exposure and management problems.

The use of immune-enhancing enteral diets in the postoperative period has given contrasting results. The purpose of this prospective, randomized, double-blinded clinical study was to evaluate the effect of immunonutrition given perioperatively on cytokine release and nutritional parameters.Patients with cancer of the stomach or colo-rectum were eligible. Subjects consumed 1 L/d of either a control enteral formula (n = 25; control group) or a formula supplemented with arginine, omega-3 fatty acids, and RNA (n = 25; verum group) for 1 week before surgery. Both formulas were given by mouth. Six hours after the operation, jejunal infusion with the same diets was started and maintained for 7 days. Blood was drawn at different time points to assess albumin, prealbumin (PA), transferrin, cholinesterase activity, retinol binding protein (RBP), interleukin-2 receptors alpha (IL-2Ralpha), IL-6, and IL-1 soluble receptors (IL-1RII). The composite score of delayed hypersensitivity response (DHR) to skin test also was determined (the higher the score, the lower the immune response).During the 7 days of presurgical feeding, none of the above parameters changed in either group. Eight days after operation, in the control group, the concentration of PA and RBP was lower than in the verum group (0.18 vs 0.26 g/L for PA and 30.5 vs 38.7 mg/L for RBP; p.05). IL-2Ralpha concentration was 507 pg/mL in the verum group vs 238 pg/mL in the control group (p.001), whereas IL-6 and IL-1RII were higher in the control group than in the verum group (104 vs 49 and 328 vs 183 pg/mL, respectively; p.01). The DHR score was 0.68 in the control group vs 0.42 in the verum group (p.05).Perioperative feeding with a supplemented enteral diet modulates cytokine production and enhances cell-mediated immunity and the synthesis of short half-life proteins.

Hepatic injury secondary to warm ischemia-reperfusion (I/R) injury and alterations in haemostatic parameters are often unavoidable events after major hepatic resection. The release of inflammatory mediator is believed to play a significant role in the genesis of these events. It has been suggested that preoperative steroid administration may reduce I/R injury and improve several aspects of the surgical stress response. The aim of this prospective randomized study was to investigate the clinical benefits on I/R injury and systemic responses of preoperatively administered corticosteroids. Seventy-six patients undergoing liver resection were randomized either to a steroid group or to a control group. Patients in the steroid group received preoperatively 500 mg of methylprednisolone. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, coagulation parameters, and inflammatory mediators, interleukin 6 and tumor necrosis factor alpha were compared between the 2 groups. Length of stay, and type and number of complications were recorded as well. Postoperative serum levels of ALT, AST, total bilirubin, and inflammatory cytokines were significantly lower in the steroid than in the control group at postoperative days 1 and 2. Changes in hemostatic parameters were also significantly attenuated in the steroid group. In conclusion, the incidence of postoperative complications in the steroid group tended to be significantly lower than the control group. It is of clinical interest that preoperative steroids administration before major surgery may reduce I/R injury, maintain coagulant/anticoagulant homeostasis, and reduce postoperative complications by modulating the inflammatory response.

Background: Interleukin-2 (IL-2) has been investigated as an adjunct to antiretroviral therapy (ART) because of its well-demonstrated capacity of stably increasing the number of peripheral CD4+ T cell lymphocytes. However, IL-2-related adverse events (AEs), including fever, tachycardia, hypotension, and respiratory failure, are typically close- and schedule-dependent and can potentially limit the application of IL-2 therapy in an outpatient setting. Nitric oxide (NO) is a potent vasodilator potentially responsible for some of the AEs caused by IL-2. Purpose: In this study, we determined NO production in a cohort of HIV-1 infected individuals receiving ART either alone or together with IL-2. Method: NO production, detected as plasma nitrate/nitrite levels by the Griess reaction, was evaluated in 3 groups of 10 individuals each. In the first group, subcutaneous (sc) administration of 12-15 million international units per day (MIU/d) of IL-2 was administered for 5 days every 8 weeks for 6 cycles together with ART; in the second group, IL-2 (6 MIU/d) was given sc for 5 days every 4 weeks for 12 cycles together with ART; whereas the third group received ART alone. Results: At baseline, the plasma nitrate/nitrite levels in the 2 groups of patients who received high and low doses of the cytokine along with ART were 28.5 +/- 18.1 mumol/L and 34.2 +/- 29.0 mumol/L, respectively. These levels were comparable to those of patients treated with only ART (18.6 +/- 22.4 mumol/L) and to those of 20 healthy controls (19.9 +/- 5.9 mumol/L). No significant increase of plasma nitrate/nitrite levels was observed by administration of either ART or ARTAL-2. In addition, NO production was not associated significantly with different levels of tumor necrosis factor-alpha, IL-6, or soluble IL-2 receptor alpha chain in 9 individuals with WHO grade 2 and 3 AEs. Conclusion: Our results indicate that NO is unlikely to be responsible for most side effects of IL-2 therapy in HIV-1 infected individuals. Because both IL-2 and virus multiplication have been reported to independently stimulate NO production, concomitant ART may curtail NO production through inhibition of HIV-1 replication.

To evaluate the safety and efficacy of 3 regimens of intermittent subcutaneous (sc) interleukin (IL)--2 in a phase 2 study, 61 antiviral drug-experienced human immunodeficiency virus (HIV)--positive patients were randomly assigned to one of the following study arms: antiretroviral therapy (ART) plus IL-2 (12 million IU [MIU] by continuous intravenous infusion, followed by 7.5 MIU twice a day, sc, every 8 weeks); ART plus IL-2 (7.5 MIU twice a day, sc, every 8 weeks); ART plus IL-2 (3 MIU twice a day, sc, every 4 weeks); or ART alone. A significant increase of circulating CD4 cells was observed in IL-2--treated subjects, compared with those given ART alone. Low doses of IL-2 were better tolerated. Despite the incomplete suppression of viral replication, IL-2 with ART did not increase either plasma viremia or cell-associated HIV DNA levels. Low doses of intermittent sc IL-2 induced a stable increase of peripheral CD4 cells that was indistinguishable from those associated with higher, less well-tolerated doses of IL-2.

Alterations in hemostatic parameters are a common finding after major hepatic resection. There is growing evidence that inflammation has a significant role in inducing coagulation disarrangement that follows major surgery. To determine whether preoperative methylprednisolone administration has a protective effect against the development of coagulation disorders, we evaluated the effect of preoperative steroids administration on changes in hemostatic parameters and plasma levels of inflammatory cytokines in patients undergoing liver surgery. Seventy-three patients undergoing liver resection were randomized to a steroid group or to a control group. Patients in the steroid group received 500 mg of methylprednisolone preoperatively. Serum levels of coagulation parameters (prothrombin time, platelets, fibrinogen, plasma fibrin degradation products [D-dimer], antithrombin III) and inflammatory mediators (IL-6 and TNF-alpha) were measured before and immediately after the operation and on postoperative days 1, 2, and 5. Multivariate analysis was performed to identify factors related to the characteristics of the patients and surgery affecting coagulation parameters between the two groups. Decreases in antithrombin III, platelet count and fibrinogen levels, prolongation of prothrombin time, and increases in the plasma fibrin degradation products were significantly suppressed by the administration of methylprednisolone. Cytokines production was also significantly suppressed by the administration of methylprednisolone, and there was significant correlation between plasma levels of cytokines and coagulation alterations. These findings suggest that preoperative methylprednisolone administration inhibits the development of coagulation disarrangements in patients undergoing liver resection, possibly through suppressing the production of inflammatory cytokines.

The U937-derived chronically HIV-infected U1 cell line and uninfected U937 cell clones were efficiently lysed by both unstimulated (NK) and IL-2-stimulated (lymphokine-activated killer; LAK) peripheral blood mononuclear cells (PBMC) of healthy HIV-seronegative donors. Pretreatment of target cells with IFN-gamma down-modulated killing of both U1 cells and two U937 cell clones, and up-regulated MHC class I expression. In contrast, TNF-alpha enhanced the sensitivity of infected U1 cells, but not of U937 cell clones to NK / LAK cell lysis. Co-cultivation of IL-2-stimulated PBMC with U1 cells triggered expression and replication of HIV by cell-cell contact, and this effect was inhibited by anti-TNF-alpha antibodies (Ab); virus production was partially inhibited by zidovudine. Of interest, anti-TNF-alpha Ab protected U1 cells from LAK cell activity. Thus, TNF-alpha can induce HIV expression from chronically infected U1 cells, but also plays an important role in sensitizing these cells to lysis.

Objective To verify whether antiphospholipid antibodies (aPL) recognize and opsonize apoptotic human cells. Methods Apoptosis was induced via CD95 crosslinking or ultraviolet irradiation. IgG and anti-β2-glycoprotein I (anti-β2-GPI) antibodies were purified from patient sera by affinity chromatography. The aPL that bound to apoptotic cells were assessed by flow cytometry, and the subdomains recognized were identified by confocal microscopy. Human macrophages were derived from monocytes, and their ability to phagocytose 3H-labeled apoptotic bodies, whether opsonized or not opsonized by aPL, was assessed. Tumor necrosis factor α (TNFα) secretion was evaluated by enzyme-linked immunosorbent assay. Results The aPL, but not control Ig or Ig from aPL-negative patients, bound to apoptotic cells, but not to viable cells. Nuclear antigens were not recognized. Opsonization of apoptotic cells by aPL substantially enhanced recognition and binding by scavenger macrophages, with massive TNFα secretion. Conclusion Antiphospholipid antibodies facilitate apoptotic cell clearance by macrophages and trigger TNFα release, possibly enhancing the immunogenicity of the autoantigens they contain.