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Biomedical subjects

C Bravo

Publications and source records attributed to C Bravo.

At least 19 recordsLinked to original sources
PubMed2006

Donor-to-host transmission of bacterial and fungal infections in lung transplantation.

The purpose of this study was to evaluate the incidence and etiology of bacterial and fungal infection or contamination in lung allograft donors and to assess donor-to-host transmission of these infections. Recipients who survived more than 24 h and their respective donors were evaluated. The overall incidence of donor infection was 52% (103 out of 197 donors). Types of donor infection included isolated contamination of preservation fluids (n = 30, 29.1%), graft colonization (n = 65, 63.1%) and bacteremia (n = 8, 7.8%). Donor-to-host transmission of bacterial or fungal infection occurred in 15 lung allograft recipients, 7.6% of lung transplants performed. Among these cases, 2 were due to donor bacteremia and 13 to colonization of the graft. Twenty-five percent of donors with bacteremia and 14.1% of colonized grafts were responsible for transmitting infection. Excluding the five cases without an effective prophylactic regimen, prophylaxis failure occurred in 11 out of 197 procedures (5.58%). Donor-to-host transmission of infection is a frequent event after lung transplantation. Fatal consequences can be avoided with an appropriate prophylactic antibiotic regimen that must be modified according to the microorganisms isolated from cultures of samples obtained from donors, grafts, preservation fluids and recipients.

Bacteria↗
PubMed2005

Preemptive therapy with intravenous ganciclovir for the prevention of cytomegalovirus disease in lung transplant recipients.

The most effective strategy for the prevention of cytomegalovirus (CMV) disease in lung transplantation has not been conclusively established. The aim of this study was to determine the efficacy of preemptive ganciclovir therapy for this purpose. Twenty-five consecutive adult patients positive for CMV before transplantation and surviving more than 30 days after the procedure were studied. Mean follow-up was 732.2 days (range, 210-1125). All patients received intravenous (IV) ganciclovir prophylaxis for the first 21 days and subsequently underwent frequent CMV antigenemia monitoring: weekly for the first 3 months, every 15 days between 3 and 6 months, and monthly thereafter. IV ganciclovir was given when antigenemia results were greater than 10 infected cells per 100,000 polymorphonuclears. The study group was compared with a historical group of 30 consecutive patients who had received IV ganciclovir prophylaxis and continued on oral ganciclovir up to day 120 posttransplantation. Eighteen of the 25 patients (72.0%) presented episodes of CMV infection. Six of the 25 patients (24.0%) had CMV disease, including 3 viral syndromes and 3 cases of pneumonitis. Four patients debuted with CMV disease, 1 of them with pneumonitis. CMV resistance to ganciclovir was observed in 2 patients. The incidence of infection was higher than in the historical group (72.0% vs 46.7%; P < .05), but there were no significant differences in the incidence of CMV disease (24.0% vs 40.0%; P = not significant [NS]). Mean time before onset of the first episode of disease was lower in the preemptive therapy group than in the comparison patients (82.8 days; range, 42-240 vs 175 days; range, 90-243; P < .05). In conclusion, preemptive therapy for CMV disease is as effective a prevention strategy as oral ganciclovir prophylaxis. However, the early appearance of CMV disease with preemptive therapy can make this approach inadvisable.

Administration, Oral↗
PubMed2005

Contamination of the nebulization systems used in the prophylaxis with amphotericin B nebulized in lung transplantation.

The contamination of nebulizer may be the origin of respiratory infections. The aim of this study was to determine the incidence of contamination in nebulizers used to nebulize amphotericin B in lung transplant (LT) patients and the relationship with bacterial isolation in sputum culture. A prospective, cross-sectional study was conducted with 41 LT patients who were administered amphotericin B with a jet nebulizer. Samples were taken from the nebulizers (prior to nebulization). Sputum culture was carried out and patients were asked whether or not they followed a cleaning and disinfection protocol (washing and brushing with soap and water followed by subsequent disinfection with the Milton method after each nebulization). Contamination was defined as such when potentially pathogenic bacteria were isolated in the nebulizer. Seventeen of the 41 nebulizers (41.4%) were contaminated. In 7 of the 17 cases (41.1%) contamination was polymicrobial. The most common microorganism was Pseudomonas aeruginosa. Fourteen of the 41 patients (34.1%) presented positive sputum cultures, most common was P aeruginosa. In 10 patients (24.3%) pathogenic bacteria was isolated both in the nebulizer and in the sputum. In four of these patients (9.7%) the species was the same. The cleaning and disinfection protocol was carried out by 16 of the 41 patients (39.0%). In 2 of the 16 patients (12.5%) who were following the protocol the nebulizer was contaminated, compared to 15 of 25 patients (60.0%) whose nebulizer was not contaminated (P < .05). Two of the 16 patients (12.%) who were following the protocol presented positive sputum culture compared to 12 of 25 (48.0%) who did not (P < .05). In conclusion, the contamination of the nebulizing systems is frequent when no strict cleaning and disinfection protocol is followed. Patients who did not follow the protocol presented a greater isolation of pathogenic bacteria in the sputum.

Amphotericin B↗
PubMed2005

Photocatalytic degradation of surfactants with immobilized TiO2: comparing two reaction systems.

The photocatalytic degradation of two industrial-grade surfactants, sodium lauryl sulphate (SLS) and sodium dodecylbenzenesulphonate (SDDBS), were achieved using TiO2 immobilised on glass Raschig rings and inside a bent tube of glass, using two different photoreactors in recirculation batch mode with a black light fluorescent tube as irradiation source. The influence of parameters pH, recalculation flow, airflow and number of treatment units were determined. For comparison purposes, the energetic cost of treatment was determined for both reaction systems as the figure-of-merit EE/O, showing that titania supported on glass Raschig rings is a more efficient system than the inner coated spring with TiO2, but this condition is strongly dependent on the surfactant identity. The best conditions for surfactants elimination were used to carry out the treatment of solutions containing two commercial detergents, reaching an 80% of removal in 60 min of irradiation.

Photolysis↗
PubMed2004

Differential usage of RNA templates by the rotavirus "in vitro" replication system.

Rotavirus genome synthesis is a two-step process; the synthesis of the eleven viral mRNAs and the production of the complementary strand (minus strand synthesis) yielding the double stranded genomic RNA (dsRNA). Purified rotavirus open cores are a helpful tool to study this replication event. These open cores can use viral dsRNA and mRNAs as template for RNA synthesis. In the present communication it was demonstrated that open cores prefers to use viral mRNA as template instead of the genomic dsRNA. The use by the open cores of both templates can be blocked through two independent strategies. In the presence of ssRNAs molecules, the use of the viral dsRNA template is completely blocked without affecting the minus strand synthesis. Nevertheless, an antisense oligonucleotide strategy previously reported to block the minus strand synthesis of the target gene do not affect the use of the dsRNA template. These results suggest the recognition of different signals in each template by the open core protein complex.

Nucleic Acid Conformation↗
PubMed2003

Blood cyclosporine C0 and C2 concentrations and cytomegalovirus infections following lung transplantation.

The aim of this study was to determine whether cyclosporine levels predose (C0) and at two hours postdose (C2) were higher among patients presenting with cytomegalovirus (CMV) infection or disease. Between days 40 and 365 posttransplantation serial C0 and C2 levels were measured in 15 lung transplant recipients. Nine developed 13 episodes of CMV infection or disease. Both C0 and C2 levels were higher during CMV infection or disease episodes. Eleven of the 13 CMV episodes (84%) displayed C0 >220 ng/mL and none had C0 <200 ng/mL. For C2, 11 of 13 CMV episodes (84%) showed C2 >1200 ng/mL and none had C2 <1000 ng/mL. Among determinations that did not coincide with a CMV episode, 7 of 21 (33%) showed C0 >220 and 9 of 21 (42%) showed C2 >1200, respectively (P<.05). In conclusion, cyclosporine blood levels are higher among patients presenting with CMV infection or disease.

Adult↗
PubMed2001

Nebulized amphotericin B prophylaxis for Aspergillus infection in lung transplantation: study of risk factors.

BACKGROUND: Aspergillus infection remains a major cause of morbidity and mortality after lung transplantation. Therefore, some strategies have been attempted, one of which is nebulized amphotericin B (nAB); however, the efficacy of this prophylaxis has not been shown clearly. The aim is to study whether nAB can protect against Aspergillus infection in lung transplant recipients. PATIENTS AND METHODS: A study of risk factors was conducted in 55 consecutive lung allograft recipients. Twenty-three potential risk factors were analyzed. In 44 (80%) patients, nAB was indicated as prophylaxis. Multivariate analysis using logistic regression was performed. RESULTS: Eighteen of the 55 patients (33%) developed infection due to Aspergillus spp. Multivariate analysis showed nAB to be a preventive factor (odds ratio: 0.13; 95% confidence interval [CI] 0.02-0.69; p < 0.05) and cytomegalovirus (CMV) disease was an independent risk factor for developing Aspergillus infection (odds ratio: 5.1; 95% CI 1.35-19.17; p < 0.05). Only 1 patient required withdrawal of the prophylaxis owing to bronchospasm. nAB was well-tolerated in the remaining patients with only a few, mild, easily controlled side effects. CONCLUSIONS: The present results show that nAB prophylaxis may be efficient and safe in preventing Aspergillus infection in lung-transplanted patients, and CMV disease increases the probability of Aspergillus infection.

Adolescent↗
PubMed2001

Metabolic changes induced by cold stress in rat liver mitochondria.

The mechanisms involved in the metabolic changes induced by cold stress in isolated rat liver mitochondria were studied. Respiration, ATP synthesis, and membrane potential as well as the contents of several metabolites were determined in liver mitochondria from cold-exposed rats. At different times of cold exposure, the force-flux relationships showed net variation in flux (enhanced respiration, diminished ATP synthesis) with no associated variation in force (H+ gradient); this suggested that decoupling rather than classical uncoupling was involved in the effects of cold stress. The flux control coefficient of the H+ leak on basal respiration was slightly increased by 380 h of cold exposure. Cold stress also induced a diminution in total membrane fatty acids, Zn2+, Fe3+, ATP, and ADP/O ratios; the content of cytochromes c + c1 and b oscillated. The contents of Ca2+, Na+, Pi, and cytochromes a + a3 were not affected, whereas matrix ADP, AMP, K+, and Mg2+ were markedly increased. Basal and oleic acid-stimulated respiration of mitochondria from cold-stressed rats was inhibited by GDP, carboxyatractyloside, or albumin. These agents did not affect basal respiration in control mitochondria. Western blot analysis showed enhanced expression of a protein of about 35 kDa, presumably the uncoupling protein 2, induced by long-term cold exposure. The overall data suggest that cold stress promoted decoupling of oxidative phosphorylation, and hence, changes in several matrix metabolites, by increasing free fatty acids and the UCP2 content.

Adenine Nucleotides↗
PubMed2001

[Ocular blood flow and characteristics of retinal detachment].

PURPOSE: To determine if ocular blood flow (OBF) changes in retinal detachment (RD) are related with its characteristics (extension, macular involvement, PVR or duration). METHODS: 60 patients with unilateral rhegmatogenous RD and 20 < > patients were selected. Color Doppler Ultrasound was used to measure OBF velocities in the ophthalmic artery (OA), central retinal artery (CRA) and vein (CRV) and posterior ciliary arteries (PCA) of both eyes of each patient. The IOP and RD characteristics were considered. In each case the paired Student's T test (OBF) and Wilcoxon test (IOP) were used for the statistical analysis (p<5%). RESULTS: Peak systolic (PS) and end diastolic (ED) velocities of OA, PS of CRA and PS and ED of PCA were decreased in the RD eyes compared to the normal ones (p<0.05). The PS and ED rates of OA and PS of CRA were also decreased (p<0.05) in the other eyes compared to the normal ones. Both the decrease in velocity and in the IOP were related with 2 or more quadrants of RD (p<0.05), macula detachment (p<0.05), PVR >/=C(2) (p<0.05) and duration of >/=15 days (p<0.05). CONCLUSION: RD correlates with decreased ocular blood flow velocities and IOP in both the RD as well as in the other eye. The worse the characteristics of the RD, the lower the velocities and the IOP

Aged↗
PubMed2000

[Lymphangioleiomyomatosis: study of 15 patients].

BACKGROUND: Lymphangioleiomyomatosis (LAM) is an uncommon disease of not well-known evolution. We describe the clinical features and follow-up of a group of patients diagnosed of LAM in a hospital pulmonary transplantation programme. PATIENTS AND METHODS: 15 women (mean age: 43, range: 36-52) diagnosed of LAM, 9 at the Hospital Vall d'Hebron and 6 referred from other hospitals, for preoperative evolution of lung transplantation, were retrospectively studied. RESULTS: Dyspnea appeared in all cases and it was the main symptom. Pleural problems in the early evolution of the disease were also very frequent (12 out of 15 patients). For this reason, pleurodesis was performed in 7 patients and pleurectomy in 2 (one of them bilateral). Thoracic CT scan showed very characteristic cystic images and abdominal CT proved the presence of extrathoracic associated angiomyolipomas in one case. In two patients, LAM was diagnosed after studying the explanted lung. These two patients had been previously misdiagnosed of emphysema and pulmonary haemosiderosis. Survival since the beginning of symptoms was 82 and 49%, 5 and 10 years later, respectively. Six out of eight patients who underwent lung transplantation had a long postoperative survival. CONCLUSIONS: LAM seems to be as infrequent in Catalunya as in other countries, even if some cases could be misdiagnosed. Lung transplantation is useful in the advanced stages of the disease and, in our experience, it has improved respiratory insufficiency in half of the patients.

Adult↗
PubMed2000

Isoniazid prophylaxis in lung transplantation.

The incidence of tuberculous disease (TD) is higher in lung-transplant patients than in the general population. During a 7-year period, we included 61 patients who underwent lung transplantation in a prospective isoniazid prophylaxis protocol. Isoniazid was prescribed to infected and anergic patients not previously treated when added to the waiting list. Six of 61 patients (10%) developed tuberculosis. We observed no differences in tuberculous disease incidence between infected-anergic and non-infected patients. In our tuberculous-endemic area, isoniazid prophylaxis is safe and offers protection from TD to infected and anergic patients who must be enrolled in a lung transplantation program.

Adolescent↗
PubMed2000

[Safety and efficacy of celiprolol in hypertensive patients with chronic obstructive lung disease].

BACKGROUND: Third generation beta blockers have an intrinsic simpatico-mimetic activity and are cardioselective. Therefore, they should not have adverse bronchial effects and could even have a slight bronchodilator activity. AIM: To test the efficacy and safety of celiprolol in hypertensive patients with chronic obstructive lung disease. PATIENTS AND METHODS: Uncomplicated hypertensive patients with chronic obstructive lung disease received celiprolol during 12 weeks. They were subjected to monthly clinical assessment and ventilatory function was measured on the basal period and at the end of the trial. RESULTS: During the study period, blood pressure fell significantly from 179 +/- 6/112 +/- 8 to 161 +/- 4.7/98 +/- 1.6 mmHg. No changes were observed in forced expiratory volume in 1 s or in forced expiratory flow between 25 and 75% of the vital capacity. No subjective changes in respiratory function were reported during the trial. CONCLUSIONS: No changes in ventilatory function were observed in these patients with chronic obstructive lung disease, treated with celiprolol during 12 weeks.

Adrenergic beta-Antagonists↗