PubMed Health⌕ Search

Biomedical subjects

A Solé

Publications and source records attributed to A Solé.

At least 19 recordsLinked to original sources
PubMed2006

Perioperative complications of lung transplantation in patients with emphysema and fibrosis: experience from 1992-2002.

UNLABELLED: Our objective was to describe the incidence of perioperative complications of lung transplantation among patients with emphysema and fibrosis and the morbidity and mortality risk factors. MATERIALS AND METHODS: We performed a retrospective study of 111 lung transplant patients engrafted from 1992 to 2002 for emphysema (n = 65) or lung fibrosis (n = 46). This descriptive study included the most frequent complications during the perioperative period in the intensive care unit. RESULTS: The most frequent intraoperative complications were reperfusion syndrome, hemodynamic instability, and cardiac arrhythmias. Among patients with emphysema, the follow-up of postoperative complications proved statistically significant on univariate analysis for an association of patient mortality with prolonged intubation (P = .005), rejection (P = .0001), hemorrhage (P = .0001), sepsis (P = .0001), renal failure (P = .001), and implantation response (P = .014). Mortality among these patients was 16.9%. Mechanical ventilation for over 48 hours and postoperative hemorrhage were the variables with the greatest predictive value for mortality in the postoperative period. Among patients with fibrosis, the complication-related mortality were reperfusion syndrome (P = .039), implantation response (P = .039), renal failure (P = .013), rejection (P = .016), and sepsis (P < .001). The mortality rate was 23.9% with sepsis (P = .000) being the most frequent cause of death in the immediate postoperative period. CONCLUSIONS: The most frequent intraoperative complications were reperfusion syndrome and hemodynamic instability. The most frequent postoperative complications were implantation response, sepsis, prolonged intubation, hemorrhage, and renal failure.

Emphysema↗
PubMed2005

Urgent lung transplantation in Spain.

BACKGROUND: Lung donors are scarce and lung transplantation resources are limited. Because urgent lung transplantation (ULT) is assumed to yield poor results, its use is controversial. We assessed the outcome of patients who received ULT seeking to determine effectiveness and risk factors. PATIENTS AND METHOD: We collected data from every ULT performed in Spain during 5 years (1998-2002). The survival of patients was studied using Kaplan-Meier, Cox regression, and chi-square statistical analyses. We compared outcomes and perioperative mortality (over 30 days) for ULT procedures, analyzing the influence of certain variables (age, type of transplant, diagnosis, indication, and time on waiting list). RESULTS: Among 109 patients proposed for the procedure, 73 ULT were performed during the period. The most frequent indications were pulmonary fibrosis (19 cases) and cystic fibrosis (19 cases), showing the worst and the better survival rates, respectively. The bad prognosis, determined mainly by per operative mortality rate (35.62%), was significantly affected by age (worse for patients older than 40 years) and type of LT (single worse than double; P < .05). A longer time waiting for ULT also showed a worse prognosis (P < .005). CONCLUSIONS: Long-term survival after ULT shows that the procedure is effective and efficient for a select group of patients, despite the high per operative risk. ULT should be reserved for younger patients. It also requires performance in a short period (just a few days), initially rejecting a single lung transplant, provided that the patient is adequately monitored.

Humans↗
PubMed2005

Lymphoproliferative disease after lung and heart-lung transplantation: first description in Spain.

Lymphoproliferative syndromes are the most common tumors in transplant recipients. More than 90% of posttransplantation lymphoproliferative syndromes (PTLS) are considered to be associated with Epstein-Barr virus, and 86% are of the B-cell line. Histopathology ranges from polymorphic-reactive to monomorphic forms. Clonality should be studied using molecular biology techniques. Clinically, a differentiation is usually made between early PTLS (occurring within 1 year after transplantation) and late PTLS, which occur as localized or disseminated nodal lymphomas. In localized forms, immunosuppression should be discontinued or decreased, and the involved area should be subsequently resected or irradiated. In disseminated cases, immunosuppression should be decreased and administration of acyclovir/ganciclovir should be considered. If this is not effective, treatment should be started with anti-CD20 monoclonal antibodies (rituximab). If no response occurs, use of chemotherapy, possibly with interferon, should be considered. Our aim was to report the incidence, clinical signs, and treatment in a series of patients undergoing lung transplantation (LTx).

Adolescent↗
PubMed2005

Pulmonary tuberculosis in lung and heart-lung transplantation: fifteen years of experience in a single center in Spain.

The increase in the number of solid organ transplants has resulted in an increased incidence of opportunistic infections, including infection by typical and atypical mycobacteria, with risk of developing tuberculosis. Pretransplant chemoprophylaxis with isoniazid has become increasingly common in an attempt to prevent the disease. The source of infection in tuberculosis (TB) may be difficult to identify. Infection may be caused by reactivation of a primary infection in the recipient, reactivation of a lesion from the donor lung, or primary infection. There are few reports on TB in lung transplantation. Incidence in the reported series ranges from 6.5% to 10%. Our series of 7 patients out of a total 271 patients (2.58%) represents a rate higher than reported for the general Spanish population, 26.7/10(5) inhabitants and for lung transplant candidates (0.18%). Our aim was to evaluate the incidence, clinical signs, and outcome of TB in our series of patients undergoing lung transplantation in the 15 years since inception of the program (February 1990 to December 2004). Morbidity and mortality was high (42.8%), but limited to patients in whom treatment was not administered or could not be successfully completed. However, early detection and treatment are essential.

Adult↗
PubMed2005

Steroid withdrawal in lung transplant recipients.

OBJECTIVE: Many of the long-term complications in lung transplantations are secondary effects of immunosuppression. Corticosteroids are partially responsible for the development of osteoporosis, raised blood pressure, diabetes, muscular disorders, gastric ulcers, and other conditions. We analyzed the long-term result of steroid withdrawal in our lung transplant recipients. MATERIALS AND METHODS: When respiratory function stabilized, to avoid secondary effects, steroid treatment was withdrawn in 34 of the 375 lung transplant patients in our centers We evaluated the characteristics of the donors and recipients, their compatibility, the pre, and post-steroid withdrawal complications, and type of immunosuppressant. RESULTS: The mean age of patients was 42 +/- 7 years and of donors, 25 +/- 9 years. The primary diseases were: 15 emphysema, six pulmonary fibrosis, 10 cystic fibrosis, and three primary pulmonary hypertension. Twenty seven patients had double lung transplants and seven single lung. The mean steroid withdrawal period was 881 +/- 237 days posttransplantation. The most frequent treatment regimen at the time of steroid withdrawal was cyclosporine, azathioprine, and minimal steroid doses. Six recipients had to be restarted on steroids one patient who required a kidney transplant, three cases due to an infectious process with a differential diagnosis of rejection, and two cases due to loss of FEV1 (forced expiratory volume in 1 s), suggestive of chronic rejection. There was an improvement in blood pressure in five patients, in plasma cholesterol and triglyceride levels in eight patients, and insulin withdrawal in two diabetic patients. CONCLUSIONS: Steroid treatment may be suspended 2 to 3 years, posttransplant in selected lung transplant recipients. The usual patient profile shows few rejection episodes with cyclosporine and azathioprine immunosuppression. What is notable is the low mean age of donors. Close clinical monitoring and lung function testing are of major importance in the weeks following steroid withdrawal.

Adolescent↗
PubMed2005

Aspergillus infections in lung transplant recipients: risk factors and outcome.

This retrospective study of 251 lung transplant patients aimed to determine the prevalence, clinical presentation and mortality of Aspergillus infection in order to define specific risk factors and to compare survival in patients with and without infection. Aspergillus was isolated from 86 (33%) cases, which involved colonisation (n = 50), tracheobronchial lesions (n = 17) or invasive aspergillosis (n = 19). Overall, aspergillosis had an impact on survival (p < 0.05); in fact the 5-year mortality rate was substantially higher in single lung transplant recipients with bronchial anastomotic infection, and in those with late-onset infections and chronic rejection. A significant association (p < 0.05) was found between acute rejection and the time at which fungal infection was diagnosed. Aspergillus infection was not related to cytomegalovirus infection or treatment with corticosteroids. The mortality rate for invasive infections was 78% and was related to survival (p < 0.0001); invasive aspergillosis was also associated with chronic rejection (p < 0.05), but not with high corticosteroid doses (p 0.49) or use of tacrolimus (p 0.73). In conclusion, Aspergillus infection was associated with a reduction in the 5-year survival rate of lung transplant recipients, and this was particularly true for patients infected with the invasive forms and for patients with single lung transplants, bronchial anastomotic infection and chronic rejection. Isolation of Aspergillus spp. from respiratory samples preceded acute rejection, and may be a marker of graft dysfunction and/or airway inflammation. Close monitoring, or even pre-emptive antifungal therapy, is recommended for patients with chronic rejection or bronchial airway mechanical abnormalities and persistent Aspergillus colonisation.

Aspergillosis↗
PubMed2004

Advanced detection systems for X-ray fluorescence excitation spectroscopy.

This paper accounts for selected detector developments carried out over the past 15 years within the ESRF X-ray Absorption Spectroscopy group. This includes various types of photodiodes used as integrated current detectors. Special emphasis is put on the long-standing development of a Si drift-diode array suitable for energy-dispersive detection of X-ray fluorescence. This detector, which is now operational, was used to record high-quality XMCD/XAFS spectra on [Fe70Pt30] nanoparticles highly dispersed on a Si wafer. Using numerically deconvoluted spectra, energy resolution was decreased to 82 eV for the Si Kalphabeta line, 126 eV for the Fe Kalpha line and 176 eV for the Pt Lalpha line. A high-vacuum-compatible high-energy-resolution crystal analyzer was also installed on ID12, making it possible to record X-ray fluorescence excitation spectra in the photon-in/photon-out mode over a wide spectral range. Prospects of adapting these methods in order to investigate biological samples are briefly discussed.

Equipment Design↗
PubMed2003

Microbial mats on the Orkney Islands revisited: microenvironment and microbial community composition.

The microenvironment and community composition of microbial mats developing on beaches in Scapa Flow (Orkney Islands) were investigated. Analysis of characteristic biomarkers (major fatty acids, hydrocarbons, alcohols, and alkenones) revealed the presence of different groups of bacteria and microalgae in mats from Waulkmill and Swanbister beach, including diatoms, Haptophyceae, cyanobacteria, and sulfate-reducing bacteria. These analyses also indicated the presence of methanogens, especially in Swanbister beach mats, and therefore a possible role of methanogenesis for the carbon cycle of these sediments. High amounts of algal lipids and slightly higher numbers (genera, abundances) of cyanobacteria were found in Waulkmill Bay mats. However, overall only a few genera and low numbers of unicellular and filamentous cyanobacteria were present in mats from Waulkmill and Swanbister beach, as deduced from CLSM (confocal laser scanning microscopy) analysis. Spectral scalar irradiance measurements with fiber-optic microprobes indicated a pronounced heterogeneity concerning zonation and density of mainly anoxygenic phototrophs in Swanbister Bay mats. By microsensor and T-RFLP (terminal restriction fragment length polymorphism) analysis in Swanbister beach mats, the depth distribution of different populations of purple and sulfate-reducing bacteria could be related to the microenvironmental conditions. Oxygen, but also sulfide and other (inorganic and organic) sulfur compounds, seems to play an important role in the stratification and diversity of these two major bacterial groups involved in sulfur cycling in Swanbister beach mats.

Bacteria↗
PubMed2003

Visceral leishmaniasis in lung transplantation.

Infection by intracellular microorganisms with a special geographic distribution, such as Leishmania spp, has been reported in a limited number of patients undergoing solid-organ transplant (SOT). No cases of Leishmania spp infection in lung transplant patients were found in a review of the literature. In our series of 222 lung or heart and lung transplantations performed from February 1990 to October 2002, two cases of visceral leishmaniasis (VL) were diagnosed and treated with liposomal amphotericin B. All cases reported to date in transplant patients, including the ones discussed here, occurred in people living in or traveling to countries in the Mediterranean area. We therefore consider it advisable to include serological testing for latent infection due to Leishmania spp in pretransplantation screening for our geographical setting, despite the limited return of this strategy.

Adult↗
PubMed2003

Cardiopulmonary transplantation: experience of a lung transplant group.

Cardiopulmonary transplantation (CPT) is indicated for patients eligible for heart transplantation (HT) or lung transplantation (LT) who have severe concomitant lung or heart disease. Only 2 groups perform CPT in Spain. We report our experience with 18 CPTs representing 8.2% and 5% compared with LT (220) and HT (362), respectively, from February 13, 1990 to October 15, 2002. The mean time on a waiting list was 138 days. The current number of surviving patients is 7 (39%), with a mean follow-up of 602 days (range, 3 to 4627 days). They all remain asymptomatic with normal respiratory function in 4 patients. No cardiac graft rejection has been detected. Two patients experienced sustained gastroparesis during the first year with spontaneous resolution. Death occurred within the first 3 months in 9 patients. These outcomes contrast with the early mortality associated with LT and HT in our series, namely 10.6% and 11%, respectively. The different causes of death were as follows: sepsis and multiorgan failure in 5 patients, hemorrhagic shock in 3 patients, and suture dehiscence and fungal aortic perforation in 1 patient. Late mortalities were recorded in 2 cases. Overall patient survival in our series is lower than that reported by the International Registry (IR), with an early mortality rate of 50% (30% IR). Nevertheless, our survival rate at 10 years after transplantation is 30% (26% IR). We conclude that CPT should be considered despite the greater early morbidity and mortality.

Adolescent↗
PubMed2003

Lung transplantation in patients with x-linked agammaglobulinemia.

Lung transplantation is an established procedure to treat patients with end-stage lung disease. The criteria for recipient selection are broadening to include patients with congenital defects of the immune system, such as X-linked hypogammaglobulinemia (XLA). We report 2 cases of successful double lung transplantation in patients with XLA. The 2 men had developed bronchiectasis and end-stage lung disease despite early institution of intravenous immunoglobulin (IVIG) replacement therapy. Before transplantation, hypogammaglobulinemia was well controlled with IVIG in both patients. After transplantation, IVIG was administered every 48 hours during the first 10 days and then tapered slowly in the following weeks until returning to an every 3 weeks schedule. One patient has been followed up for 12 months and the other for 6 months. Lung function normalized in the first case and showed a restrictive pattern in the second one. Lung transplantation may be considered as a therapeutic option for patients with XLA and end-stage lung disease. Regular administration of IVIG overcomes the high risk of infections due to the severe immunodeficiency and the intensive immunosuppressive therapy.

Adult↗
PubMed2001

Ab initio calculations on the mechanism of the oxidation of the hydroxymethyl radical by molecular oxygen in the gas phase: a significant reaction for environmental science.

The mechanism of the gas-phase reaction of *CH2OH+O2 to form CH2O+HO2* was studied theoretically by means of high-level quantum-chemical electronic structure methods (CASSCF and CCSD(T)). The calculations indicate that the oxidation of *CH2OH by O2 is a two-step process that goes through the peroxy radical intermediate *OOCH2OH (1), formed by the barrier-free radical addition of *CH2OH to O2. The concerted elimination of HO2* from 1 is predicted to occur via a five-membered ringlike transition structure of Cs symmetry, TS1, which lies 19.6 kcalmol(-1) below the sum of the energies of the reactants at 0 K. A four-membered ringlike transition structure TS2 of Cs symmetry, which lies 13.9 kcalmol(-1) above the energy of the separated reactants at 0 K, was also found for the concerted HO2* elimination from 1. An analysis of the electronic structures of TS1 and TS2 indicates that both modes of concerted HO2* elimination from 1 are better described as internal proton transfers than as intramolecular free-radical H-atom abstractions. The intramolecular 1,4-H-atom transfer in 1, which yields the alkoxy radical intermediate HOOCH2O*, takes place via a puckered ringlike transition structure TS3 that lies 13.7 kcalmol(-1) above the energy of the reactants at 0 K. In contrast with earlier studies suggesting that a direct H-atom abstraction mechanism might occur at high temperatures, we could not find any transition structure for direct H-atom transfer from the OH group of *CH2OH to the O2. The observed non-Arrhenius behavior of the temperature dependence of the rate constant for the gas-phase oxidation of *CH2OH is ascribed to the combined effect of the initial barrier-free formation of the *OO-CH2OH adduct with a substantial energy release and the existence of a low-barrier and two high-barrier pathways for its decomposition into CH2O and HO2*.

Atmosphere↗
PubMed2001

The 1,2,4-triazolyl cation: thermolytic and photolytic studies.

The generation of the 1,2,4-triazolyl cation (1) has been attempted by the thermolysis and photolysis of 1-(1,2,4-triazol-4-yl)-2,4,6-trimethylpyridinium tetrafluoroborate (2) and the thermolysis of 1- and 4-diazonium-1,2,4-triazoles, using mainly mesitylene as the trapping agent. Thermolysis of 2 gave mostly 1,2,4-triazole, together with 3-(1,2,4-triazol-4-yl)-2,4,6-trimethylpyridine, 4-(1,2,4-triazol-4-ylmethyl)-2,6-dimethylpyridine, and 4-(2,4,6-trimethylbenzyl)-2,6-dimethylpyridine. Thermolysis of each of the diazonium salts in the presence of mesitylene again gave mainly triazole together with very low yields of 1-(1,2,4-triazol-1-yl)-2,4,6-trimethylbenzene and the corresponding -4-yl isomer in about the same ratio. On the other hand, photolysis of 2 in mesitylene gave mainly 1-(1,2,4-triazol-1-yl)-2,4,6-trimethylbenzene. A photoinduced electron transfer from mesitylene to 2 has been observed and preliminary laser flash photolyses of 2 and the corresponding 2,4,6-triphenylpyridinium salt have been carried out. The observed transients are explained as arising from the first excited states of the pyridinium salts rather than from 1. Ab initio MO calculations are reported and indicate that the predicted electronic ground-state of the triazolyl cation is a triplet state of B1 symmetry with five pi electrons, which corresponds to a diradical cation (1c). Possible mechanisms for the formation of the various products are proposed.

Journal Article↗
PubMed2001

Confocal laser scanning microscopy as a tool to determine cyanobacteria biomass in microbial mats.

We have developed a method based on confocal laser scanning microscopy for detection and quantification of cyanobacteria from the Ebro Delta microbial mats. Cyanobacteria play a major role as primary producers in microbial mats; it is difficult, however, to apply classical methods to estimate their biomass because they establish strong interactions with detritic particles. The protocol described here allows the localization of individual cells or filaments with micrometre precision without the need to either manipulate or stain the samples. This method is suitable for studying biomass 'in situ' in microbial mats.

Biomass↗