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C Pellegrini

Publications and source records attributed to C Pellegrini.

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

"Twinning procedure" in lung transplantation: influence of graft ischemia on survival and incidence of complications.

The limited number of suitable lung donors is the major obstacle to clinical application of lung transplantation. The "twinning procedure" may represent one strategy to optimize the use of the small pool of available grafts. From November 1991 to May 2003, 99 single lung transplants (SLTx) were performed including 46 (46%) cases of the "twinning procedure." We divided the study population into two groups: group A (recipients of the "first" lung) and group B (recipients of the "second" lung). The ischemia time was significantly different (A: 216 +/- 48 minutes, B: 310 +/- 89 minutes, P <.001). Differences were not observed in the incidence of graft failure (A: 2, B: 0, P = NS), in the length of mechanical ventilation (A: 12.8 +/- 29.4 days, B: 7.8 +/- 15.2 days, P = NS), or ICU stay (A: 18.8 +/- 50.6 days, B: 15.2 +/- 17.1 days, P = NS), or of hospitalization (A: 37.8 +/- 56.8 days, B: 31.4 +/- 31.7 days, P = NS). Three bronchial anastomotic complications occurred in each group. The incidence of infections (A: 0.015 events/patient/month, B: 0.011 events/patient/month, P = NS) and of treated acute rejections (A: 0.011 events/patient/month, B: 0.011 events/patient/month, P = NS) was similar in the two groups. One-year survival rates were 86% +/- 7% and 72% +/- 10% in group A and B patients, respectively (P = NS). In our experience the different ischemia times related to the twinning procedure did not increase the mortality or morbidity in the early and midterm period.

Bronchoscopy↗
PubMed2004

Heterotopic heart transplantation: a single-centre experience.

INTRODUCTION: Orthotopic heart transplantation (OHTx) represents the therapy of choice for end-stage heart disease not treatable with medical or conservative surgical approach. Heterotopic heart transplantation (HHTx) is a surgical procedure in which the graft is connected to the native heart in a parallel fashion and it was especially employed in precyclosporine era. The aim of this paper is to present our experience with HHTx. METHODS: From November 1985 till May 2003, 713 heart transplanted patients included 12 (1.7%) received HHTx. Eleven were male, mean age was 50.7 +/- 5.8 years. Five patients suffered from dilated cardiomyopathy and seven from ischemic cardiomyopathy. Indication for HHTx was: a body size mismatch in 11 cases and availability of a marginal organ in one case. RESULTS: Mean ischemic time was 149 +/- 48 minutes and mean cross-clamp time was 82.3 +/- 19.1 minutes. In four cases left ventricle aneurysm resection was associated with HHTx. Hospital mortality was 8.3% (one patient due to multiorgan failure). The actuarial survival rates were 92% and 64% at 1 and 5 years, respectively. The causes of death were: liver cancer, liver cirrosis, aortic dissection, cerebrovascular accident, and chronic rejection. CONCLUSIONS: In our experience, HHTx survival rate is comparable to OHTx. Because of the scarcity of donors, use of an undersized or marginal graft is a valid option to increase the number of transplanted patients. The major disadvantages of HHTx are the need for anticoagulant therapy, the more difficult hemodynamic and immunologic follow-up, and the presence of the diseased native heart.

Adult↗
PubMed2004

Heart transplantation in patients with amyloidosis: single-center experience.

INTRODUCTION: Amyloidosis is a systemic disease. Heart transplantation in this subset of patients is contraindicated by the majority of authors. In our center, patients with heart failure due to amyloidosis have been evaluated for cardiac transplantation since 1991. The aim of this study was to analyze the outcome of these patients waiting for transplant and the effectiveness of this therapy. MATERIALS AND METHODS: Since 1991, eight patients affected by amyloidosis have been evaluated and enrolled on the waiting list for transplant: five affected by AL lambda type; two by APO A1; and one by TTR. Four were transplanted, three died waiting for a donor (two from cardiac failure, one from sudden death), and one has been recently transplanted after 17 months on waiting list. RESULTS: Since 1985, 713 patients underwent heart transplantation in our center, five of whom were affected by amyloidosis (0.7%). Two are still alive (60 and 41 months) without evidence of cardiac amyloidotic infiltration. One patient recently underwent a combined heart-liver transplantation. Two patients died after the intervention: one sudden death after 23 months with amyloidotic infiltration of transplanted heart, and one multiple organ failure (MOF) due to progression of the systemic disease. CONCLUSIONS: Despite the small size of the group preventing us from drawing definitive conclusion, heart transplantation may prevent therapy to arrest organ damage in patients with isolated cardiac involvement. Cardiac events are the main cause of death. Patients must be followed-up for evolution of systemic disease. The midterm survival is encouraging.

Amyloidosis↗
PubMed2003

Properties of the ultrashort gain length, self-amplified spontaneous emission free-electron laser in the linear regime and saturation.

VISA (Visible to Infrared SASE Amplifier) is a high-gain self-amplified spontaneous emission (SASE) free-electron laser (FEL), which achieved saturation at 840 nm within a single-pass 4-m undulator. The experiment was performed at the Accelerator Test Facility at BNL, using a high brightness 70-MeV electron beam. A gain length shorter than 18 cm has been obtained, yielding a total gain of 2 x 10(8) at saturation. The FEL performance, including the spectral, angular, and statistical properties of SASE radiation, has been characterized for different electron beam conditions. Results are compared to the three-dimensional SASE FEL theory and start-to-end numerical simulations of the entire injector, transport, and FEL systems. An agreement between simulations and experimental results has been obtained at an unprecedented level of detail.

Journal Article↗
PubMed2003

Multiple fragments of human TG are capable of inducing oral tolerance to whole human TG.

Oral tolerance is the mechanism by which the immune system remains unresponsive to orally administered soluble antigens. Mice immunized with human TG (hTG), resulting in the induction of experimental autoimmune thyroiditis (EAT), provide an ideal in vivo system in which to examine oral tolerance to hTG. In the present study, we characterize epitopes of hTG that are capable of inducing oral tolerance. hTG is a large homodimeric protein, 660 Kd. The limited proteolysis of hTG using trypsin (TR) generates several smaller fragments of hTG ranging in size from 29 Kd to 145 Kd. Using hTG fragments h1TR (residues 1-521), h4bisTR (residues 2513-2713), h6TR (residues 522-1626), and h7TR (residues 1627-2512), prepared from both iodine rich and iodine poor hTG, we investigated the ability of these fragments to induce oral tolerance. The oral administration of iodine rich h6TR or h7TR suppresses hTG specific immune responses in a manner similar to whole hTG. In contrast, the oral administration of iodine rich h1TR or h4bisTR exacerbates hTG specific immune responses. Unlike iodine rich h1TR or h4bisTR, the oral administration of iodine poor h1TR or h4bisTR fails to augment hTG specific immune responses. In fact, h4bisTR suppresses hTG specific immune responses. These results indicate that hTG contains multiple epitopes that differentially affect oral tolerization. Tolerogenic epitopes reside within fragments h6TR and h7TR. The removal of iodine, and presumably hormone, from h4bisTR converts an immunogenic epitope to a tolerogenic epitope.

Administration, Oral↗
PubMed2003

Monocyte chemoattractant protein-1 levels in bronchoalveolar lavage fluid of lung-transplanted patients treated with tacrolimus as rescue treatment for refractory acute rejection.

BACKGROUND: Cytokines are important mediators of the complex process of extravasation and influx of peripheral mononuclear cells into a site of graft injury, an action that may be affected by the immunosuppressive regimen. The aim of this study was to compare the effect of different immunosuppressive regimens on cytokine expression in the grafted lung. METHODS: We analyzed the cytokine profiles in broncho-alveolar lavage fluid (BAL-F) from 18 lung transplanted patients undergoing a shift from a cyclosporine- to a tacrolimus-based triple therapy regimen due to refractory acute rejection. RESULTS: Three months after the conversion to tacrolimus, BAL-F levels of interleukin 8 (IL8), IL18, IL12 and IL10 were not significantly different than those measured before conversion. In contrast, monocyte chemoattractant protein-1 (MCP-1) levels showed a significant and sustained decrease in BAL-F during tacrolimus therapy. In addition the levels of gamma interferon (IFN-gamma) in the BAL-F were decreased albeit not significantly. CONCLUSIONS: These findings suggest that the clinical and functional stabilization of patients observed after conversion to a tacrolimus based regimen, may be due, at least in part, to the induced down-regulation of MCP-1 production.

Acute Disease↗
PubMed2003

Lung transplantation in a Jehovah's witness. Case report in a twinning procedure.

Jehovah's Witnesses, patients who refuse blood transfusions, are generally not considered as candidates for lung transplantation owing to the frequent requirement for transfusions. A successful procedure in a Jehovah's Witness is presented and to our knowledge this is the 2(nd) reported case. The patient, a 38-year-old female, type I diabetes, affected by idiopatic pulmonary fibrosis underwent left lung transplantation. From the same pulmonary bloc a twinning procedure was obtained by means of right lung transplantation in a 58-year-old man affected by the same pathology. Surgical strategies employed in achieving a successful outcome, ethical and moral aspects are discussed.

Adult↗
PubMed2002

Improving accuracy in identifying the gastroesophageal junction during laparoscopic antireflux surgery.

BACKGROUND: Proper construction of an effective fundoplication to control reflux depends on accurate identification of the gastroesophageal junction (GEJ). In laparoscopic surgery, the accuracy of this GEJ determination is unknown. METHODS: In 40 consecutive laparoscopic antireflux procedures, the GEJ location was determined independently by endoscopy and laparoscopy, and the differences were measured. After this was completed, endoscopic examination of the fundoplication was performed. RESULTS: The "laparoscopic" GEJ was identified within 1 cm of the "endoscopic" GEJ in 36 of 40 (90%) patients. In four patients, this difference was greater and the GEJ always higher than determined by laparoscopy. These patients had greater acid exposure and esophageal injury. On two occasions, the fundoplication was reconstructed on the basis of endoscopic findings. CONCLUSIONS: With laparoscopy, the surgeon can accurately determine the GEJ location in most patients. In approximately 10%, the GEJ is actually higher than the surgeon believes, and the fundoplication may be created lower than intended. Intraoperative endoscopy helps to identify the GEJ location and evaluate the wrap once completed.

Adult↗
PubMed2002

Fundamental and harmonic microbunching in a high-gain self-amplified spontaneous-emission free-electron laser.

Electron beam microbunching in both the fundamental and second harmonic in a high-gain self-amplified spontaneous emission free-electron laser (SASE FEL) was experimentally characterized using coherent transition radiation. The microbunching factors for both modes (b(1) and b(2)) approach unity, an indication of FEL saturation. These measurements are compared to the predictions of FEL simulations. The simultaneous capture of the microbunching and SASE radiation for individual micropulses correlate the longitudinal electron beam structure with the FEL gain.

Journal Article↗
PubMed2002

Experimental characterization of nonlinear harmonic radiation from a visible self-amplified spontaneous emission free-electron laser at saturation.

Nonlinear harmonic radiation was observed using the VISA self-amplified, spontaneous emission (SASE) free-electron laser (FEL) at saturation. The gain lengths, spectra, and energies of the three lowest SASE FEL modes were experimentally characterized. The measured nonlinear harmonic gain lengths and center spectral wavelengths decrease with harmonic number, n, which is consistent with nonlinear harmonic theory. Both the second and third nonlinear harmonics energies are about 1% of the fundamental energy. These experimental results demonstrate for the first time the feasibility of using nonlinear harmonic SASE FEL radiation to produce coherent, femtosecond x rays.

Journal Article↗
PubMed2001

Quantum effects in high-gain free-electron lasers.

A many-particle fully quantized theory for a free-electron laser which is valid in the high-gain regime is presented. We examine quantum corrections for the high-gain single-pass free-electron laser. It is shown that quantum effects become significant when the photon energy becomes comparable to the gain bandwidth. The initiation of the free-electron laser process from quantum fluctuations in the position and momentum of the electrons is considered, and the parameter regime for enhanced start-up is identified. Photon statistics of the free-electron laser radiation are discussed, and the photon number statistics for the self-amplified spontaneous emission are calculated.

Journal Article↗
PubMed2001

Differential vulnerability of cortical and cerebellar neurons in primary culture to oxygen glucose deprivation followed by reoxygenation.

The effects of glucose and O2 deprivation (OGD) on the survival of cortical and cerebellar neurons were examined to characterize the biochemical mechanisms involved in OGD and OGD followed by reoxygenation. To this aim, neurons were kept for different time periods in a hypoxic chamber with a controlled atmosphere of 95% N(2) and 5% CO2 in a glucose-free medium. After OGD, reoxygenation was achieved by exposing the cells to normal O2 and glucose levels. Neither MTT, an index of mitochondrial oxidative phosphorylation, nor malondialdehyde (MDA) production, a parameter measuring lipid peroxidation, were affected by 1 hr of OGD in cortical neurons. When OGD was followed by 24 hr of reoxygenation, MTT levels were reduced by 40% and MDA was significantly increased, whereas cellular ATP content did not change. Cerebellar granule cells, on the other hand, did not show any reduction of mitochondrial activity after exposure to 1 hr OGD or to 1 hr OGD plus 24 hr of reoxygenation. When OGD was prolonged for 2 hr, a significant reduction of the mitochondrial activity and of cellular ATP content occurred, coupled to a significant MDA increase in cerebellar granule cells, whereas in cortical neurons a reduction of MTT levels after 2 hr OGD was not accompanied by a decrease of cellular ATP content nor by an increase of MDA production. Moreover, 24 hr of reoxygenation further reinforced lipid peroxidation, LDH release, propidium iodide positive neurons and the reduction of ATP content in cerebellar granule cells. The results of the present study collectively show that cortical and cerebellar neurons display different levels of vulnerability to reoxygenation followed by OGD. Furthermore, the impairment of mitochondrial activity and the consequent overproduction of free radicals in neurons were observed for the first time occurring not only during the reoxygenation phase, but already beginning during the OGD phase.

Adenosine Triphosphate↗
PubMed2001

Conditions of vector delivery improve efficiency of adenoviral-mediated gene transfer to the transplanted heart.

OBJECTIVES: Conditions for ex vivo gene transfer to the transplanted heart were studied in a model of syngeneic abdominal heterotopic heart transplantation in the rat. Various methods of adenoviral-mediated gene transfer to the transplanted heart were compared. METHODS: In the first experiment, a dose response study, an adenoviral vector encoding the beta-galactosidase gene was infused into the donor heart with the pulmonary artery open and flushed out prior to performing the transplant. In the second experiment, the effects of clamping the pulmonary artery during vector infusion and not flushing out the viral solution, resulting in vector dwell during the warm ischemia, were examined. RESULTS: In the first experiment, gene transfer was relatively inefficient; however, transgene expression improved with increases in the vector dose (range, 1x10(7)-1x10(9)). The efficiency of gene transfer was significantly greater when the conditions of the second experiment were applied. In all models studied, cardiomyocytes and not vascular endothelial cells were the predominant cell type transduced. CONCLUSIONS: This study indicates that the conditions of adenoviral vector delivery are critical for optimizing gene transfer in the transplant setting. In addition, intravascular administration of adenoviral vector to the donor heart results predominantly in cardiomyocyte transgene expression.

Adenoviridae↗
PubMed2001

Neoplastic disease after heart transplantation: single center experience.

OBJECTIVES: Mandatory use of prolonged immunosuppression in organ transplantation is complicated by an increased incidence of cancer. The current study represents a retrospective analysis of the incidence of neoplasms in our heart transplantation program. METHODS: Four-hundred and seventy-four patients (403 male and 71 female; mean age, 48.6+/-12.1 years), with at least 30 days of follow-up, were enrolled in this study. Patients received triple immunosuppression with cyclosporin A, azathioprine and steroids. Moreover, as a prophylactic anti-lymphocyte therapy, 388 patients (82%) were administered RATG, 67 patients (14%) received ALG and 19 patients (4%) OKT3. The mean follow-up time was 71.1+/-43.0 months. RESULTS: Fifty-five patients (11.6%) developed malignant neoplasms. The cancer frequencies were: solid tumors, 55%; non-Hodgkin lymphomas (NHL), 20%; Kaposi's sarcomas, 11%; skin cancers, 9%; undifferentiated sarcomas and myelomas, 5%. Solid tumors mainly affected the lung (39%), bowel (16%), stomach (6.5%), liver (6.5%), pancreas (6.5%) and oral cavity (6.5%). The times to the onset of cancer from transplantation were: Kaposi's sarcoma, 12.7+/-16.8 months; skin cancers, 34.5+/-23.8 months; solid tumors, 54.3+/-38.7 months; NHL, 60.1+/-36.4 months; undifferentiated sarcomas and myelomas, 90.0+/-15.6 months. As determined by univariate and multivariate analyses, sex, number of treated rejections, previous history of tumor, average dose of cyclosporine and prednisone and cyclosporine blood levels did not increase the incidence of malignancies. Univariate analysis suggests a significant correlation between the type of prophylactic immunoglobulins and the average dose of azathioprine with the incidence of neoplasms. Both univariate and multivariate analyses demonstrated a significant correlation between patient's age at the time of transplantation and risk of cancer occurrence (risk increased by 1.074/year; P=0.0056 with multivariate Cox regression). CONCLUSIONS: Cancer is a strong limitation for long-term survival after heart transplantation. The only risk factor recognized is the patient's age at the time of transplant. Furthermore, the type of prophylactic globulins used for induction therapy and some specific immunosuppressant agent (azathioprine) may play a significant role in the development of malignancies after transplantation.

Adult↗
PubMed2001

High order statistics for image classification.

This paper addresses the problem of image classification using local information which is aggregated to provide global representation of different image classes. Local information is adaptively extracted from an image database using Independent Component Analysis (ICA) which provides a set of localized, oriented, and band-pass filters selective to independent features of the images. Local representation using ICA techniques has been previously investigated by several researchers. However, very little work has been done on further use of these representations to provide more complex and global description of images. In this paper, we present an algorithm which uses the energy of a minimal set of ICA filters to provide class-specific signatures which are shown to be strongly discriminant. Computer simulations are carried on two image databases, one consisting of five classes--referred to as categories--(buildings, rooms, mountains, forests and beaches) and one consisting of a set of 30 objects from multiple views for viewpoint invariant object recognition. The classification performance of the algorithm using both Independent and Principal Component Analyses are reported and discussed.

Image Processing, Computer-Assisted↗
PubMed2000

Gene transfer of endothelial nitric oxide synthase to pulmonary allografts: impact on acute rejection.

Experiments were designed to study whether overexpression of nitric oxide (NO) from endothelial nitric oxide synthase (eNOS) affects acute rejection. Allogenic, orthotopic single-lung transplantation was performed after transbronchial adenoviral-mediated gene transfer (3 x 10(8) pfu) of either of eNOS or beta-galactosidase to donor lungs of rats (n = 6 each). No immunosuppression was used. After 4 days, transplanted lungs were prepared for enzyme activity, cGMP and histology. Calcium-dependent NOS activity, reflecting eNOS, was greater in eNOS-transduced lungs (587 +/- 97 vs 2.1 +/- 1.4 pmol/mg protein per h, P <0.001). In contrast, calcium-independent NOS activity, reflecting iNOS, was comparable. Concentrations of cGMP were higher in eNOS-transduced lungs (13.2 +/- 2.3 vs 4.9 +/- 0.5 pmol/mg protein). Positive immunostaining for eNOS was present in pneumocytes only in eNOS-transduced lungs. No difference in histological grade of rejection was observed. eNOS gene transfer to pulmonary allografts results in a functionally active transgene product and increased NO production. Increasing NO from eNOS does not affect histogically identified acute rejection.

Adenoviridae↗
PubMed2000

Improved efficiency of gene transfer to the transplanted lung by retrograde vascular gene delivery.

Experiments were designed to evaluate the efficiency of antegrade compared to retrograde vascular gene transfection of donor lungs used for transplantation. Rat donor lungs (n = 5/group) were transduced with an adenoviral vector encoding for beta-galactosidase (AdbetaGal), either antegrade in the pulmonary artery (Group A, 3 x 10(8) pfu, Group B, 3 x 10(9) pfu) or retrograde into the pulmonary vein (Group C, 3 x 10(8) pfu), immediately after pneumoplegia. After storage at 4 degrees C for 1 h, the transduced lungs were transplanted orthotopically in syngeneic animals. The lungs were assessed for transgene expression by ELISA and X-Gal-staining at day 7 after operation. Inflammation was graded based on the extent of inflammatory cell infiltration. Transgene expression was similar between Groups A (1.7 +/- 0.7 ng/mg protein) and B (2.1 +/- 1.0 ng/mg protein). With retrograde delivery, there was a four-fold (8.3 +/- 2.6 ng/ mg protein) increase (P < 0.05) in transgene expression compared to either group A or B. In all groups, pneumocytes were transduced most frequently. The degree of inflammation correlated positively with the extent of transgene expression (r = 0.75, P < 0.01). The efficiency of vascular gene delivery to transplanted lungs can be improved by retrograde delivery of the vector via the pulmonary vein. Transgene expression predominates in pneumocytes following both antegrade and retrograde delivery. The severity of inflammation in the transplanted lung appears to correlate with the extent of transgene expression.

Adenoviridae↗