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Biomedical subjects

M Peña

Publications and source records attributed to M Peña.

At least 19 recordsLinked to original sources
PubMed2006

Pulmonary toxicity associated with sirolimus treatment in kidney transplantation.

INTRODUCTION: An important side effect of sirolimus, a drug often used in organ transplantation, is pulmonary toxicity. MATERIALS AND METHODS: We present five kidney transplant patients who developed this toxicity associated with sirolimus. All underwent chest radiography computed tomography, fiberoptic bronchoscopy with bronchoalveolar lavage (BAL), microbiological studies of the bronchial aspirate, blood, and sputum, and cytomegalovirus (CMV) polymerase chain reaction (PCR) in blood as well as two had transbronchial biopsies. RESULTS: All five were men of mean age 54.8 +/- 10.3 years. In two sirolimus formed part of de novo therapy, and three were converted from calcineurin inhibitors. The mean treatment time was 16.6 +/- 13.7 months, with trough levels of 11.3 +/- 3 ng/mL. The patients presented with fever, cough, dyspnea, anemia, and dyslipidemia. The radiological pattern was diffuse alveolointerstitial (n = 2), or bilateral basal interstitial (n = 2), or bilateral basal alveolar (n = 1). The cell count in the BAL was 95% to 99% macrophages. In two patients cultures for bacteria were positive: Hemophilus and Pseudomonas. Tests for fungi, mycobacteria, pneumocystis, and legionella, as well as PCR for CMV were all negative. Transbronchial biopsy yielded insufficient material in one patient and a deposit of fibrinoid material and nonnecrotizing granuloma in the other. Antibacterial therapy was started, three with cotrimoxazole and two with ganciclovir, with no response. The respiratory symptoms improved after withdrawal of sirolimus (mean, 2.4 +/- 1.5 days). The mean hospital stay was 19.8 +/- 14.1 days. CONCLUSION: Pulmonary toxicity due to sirolimus should be included in the differential diagnosis of kidney transplant patients who display signs of interstitial pneumonia. Its diagnosis is difficult requiring exclusion of other pulmonary diseases. Resolution of the symptoms was quick after suspension of the drug.

Adult↗
PubMed2006

Posttransplant lymphoproliferative disease: a series of 23 cases.

Posttransplant lymphoproliferative disease (PTLD) is a rare but clinically important disorder due to its increasing incidence and its impact on renal function and the life of the patient. Between 1979 and 2005, this center performed 1614 kidney transplants, and 23 patients had PTLD. We undertook a retrospective study, analyzing risk factors, presentation, and evolution of the disorder. The most common clinical presentation was fever and adenopathy. All cases except one received calcineurin inhibitors, and nine were treated with monoclonal or polyclonal antibodies. Serology for Epstein Barr virus (EBV) was negative in nine patients at the time of transplant, and in five it became positive on diagnosis of PTLD. The predominant disorder was non-Hodgkin's lymphoma (NHL), either polymorphous (n = 11) or monomorphous (n = 7). The base therapy consisted of reducing or suspending calcineurin inhibitors and the addition of sirolimus and antivirals. Three patients received rituximab, and five chemotherapy. The disease progressed in 36% of the polymorphous NHL, in 67% of the monomorphous, and in 100% of the Hodgkin's lymphoma, whereas 10 patients had remission. Renal function worsened on diagnosis in eight patients, and the graft was infiltrated in five (confirmed histologically). Five patients lost the graft and 12 died; six due to infection and five due to PTLD. Survival was worse in the patients aged over 55 years. We conclude that in most cases EBV is positive on diagnosis of the PTLD, an age older than 55 years affords a poor prognosis, and lymphocyte infiltration of the graft is common, as is worsening renal function.

Humans↗
PubMed2005

Variables affecting efficiency of molasses fermentation wastewater ozonation.

The main operating variables affecting ozonation efficiencies of wastewater from beet molasses alcoholic fermentation have been studied. Semibatch experiments have been performed in order to analyze the influence of pH, bicarbonate ion, temperature and stirring rate on color and organic matter removals. The efficiencies were similar regardless of the pH, which indicates that direct reactions of ozone with wastewater organics were predominant to radical reactions. Gel permeation chromatography confirmed the reduction in the concentration of organics absorbing light at 475 nm after ozonation. The elimination of bicarbonate ion, strong inhibitor of hydroxyl radical reactions, yielded an improvement in both color and COD reduction efficiencies. Acidification for removing bicarbonate ions produced a shift of colored compounds to smaller molecular weights. The highest efficiencies were achieved at 40 degrees C. Color and COD reductions at 40 degrees C were about 90% and 37%, respectively. In no case, the percentage of TOC removed was higher than 10-15%. Stirring rate had a slightly positive effect during the first stage of the ozonation showing that mass transfer played a role only during the initial reaction phase when direct attack of ozone molecules to aromatic/olefinic structures of colored substances was the predominant pathway.

Bicarbonates↗
PubMed2005

Clinical disease activity and titers of anti-dsDNA antibodies measured by an automated immunofluorescence assay in patients with systemic lupus erythematosus.

Autoantibodies specific for double stranded DNA (anti-dsDNA Abs) are a serological biomarker of systemic lupus erythematosus (SLE) and constitute useful tools for monitoring many SLE patients. A new automated immunofluorescence and quantitative assay (EliA dsDNA) has recently become available. Its performance has been demonstrated to be equivalent to the Farr and Crithidia luciliae fluorescence (CLIFT) tests. The aim of the present work was to assess the utility of this new assay to monitor clinical activity in a large cohort of SLE patients. To this end, 1020 sera from 181 SLE patients were evaluated by the two methods. Results showed a higher frequency of positive results of anti-dsDNA Abs during lupus flares measured by EliA dsDNA than by CLIFT. Likewise, titers of those Abs were significantly increased in active SLE in comparison with inactive SLE when measured by EliA dsDNA but not by CLIFT. Serum titers of anti-dsDNA Abs by both assays showed a significant negative association with concentrations of C3 and C4. In summary, this retrospective study on a large cohort of patients demonstrated that EliA dsDNA was at least as useful as CLIFT as monitoring tool in the follow-up of SLE patients, but with the advantages of being automated, quick and quantitative.

Adolescent↗
PubMed2004

Clinical utility of anti-CCP antibodies in the differential diagnosis of elderly-onset rheumatoid arthritis and polymyalgia rheumatica.

BACKGROUND: In a significant number of patients the differential diagnosis between elderly-onset rheumatoid arthritis (EORA) and polymyalgia rheumatica (PMR) is very difficult because of the lack of specific serum markers. Anti-cyclic citrullinated peptide antibodies (anti-CCP Abs) have recently been shown to be highly specific for rheumatoid arthritis (RA). This is the first study addressing the utility of these antibodies in the differential diagnosis between EORA and PMR. METHODS: Serum samples from 57 EORA patients and 49 PMR patients were studied for the presence of anti-CCP Abs and rheumatoid factor (RF). As controls, samples from 41 RA patients (age at onset <60 yr) and 24 aged healthy subjects were analysed. RESULTS: Sixty-five per cent of EORA patients had anti-CCP Abs, whereas none of the PMR patients or the aged healthy subjects was positive for those antibodies. Ten of the EORA patients started with polymyalgic symptoms and two of them were positive for anti-CCP Abs. Interestingly, there was a significant correlation between anti-CCP Abs and RF in EORA but not in young RA patients. CONCLUSIONS: The presence of anti-CCP Abs in a patient with clinical symptoms of PMR must be interpreted as highly suggestive of EORA.

Age of Onset↗
PubMed2004

[Acute obstructive renal failure secondary to retroperitoneal mass].

The acute renal failure is a grave pathology, of rapid establishment and relatively frequent in the hospital environment. We can describe three etiological groupS, which are responsible for it, amongst which are emphasized the pre-renal reasons. The obstructive pathology, of minor incidence, increases with the age. It is described the case of a 67-yr-old patient who was admitted in the Nephrology Service because of abrupt decline of the renal function. Among the initial symptoms, he presented arterial hypertension (190/90) and preserved diuresis. Blood analysis: urea 199 mg/dl, creatinine 7.7 mg/dl, without proteinuria. Sonography reported a bilateral ureteral hydronephrosis with simple cyst of possible ischemic origin. In view of the absence of previous biochemical data of renal failure, we considered possible reasons which start with an acute pattern. In initial evaluation, pre-renal etiology was not seen (high blood pressure, right cardiac systole function). The absence of prostatic syndrome and sonography discovery did not justify a diagnosis of urinary tract obstruction. Finally, abdominal-pelvic scan showed a periaortic retroperitoneal mass which included both ureters and appeared to trigger the obstruction. Combined efforts were pursued with the Urology Service, which implanted a bilateral "double J" catheter and later operated surgically on the patient, carrying out an alternating ureterolysis of both ureters. The biopsy manifested a retroperitoneal fibrosis, and the renogram showed a residual renal function of 20% in the right kidney and 80% in the left kidney. Due to the failure of the previous measures and as a last therapeutic recourse when one year had passed from the diagnosis, a continuous regimen with tamoxifen (anti-estrogen drug) in dose of 20 mg/dl each 12 hours was started, which began a progressive remission in the size of the observed mass by scan (CT) and magnetic resonance (MR). The treatment was completed during 12 months and in this time, the levels of blood urea nitrogen and creatinine were reduced gradually too. Finally, at the end of the treatment, the magnetic resonance demonstrate the complete disappearance of the fibrosis.

Acute Kidney Injury↗
PubMed2003

Chemical oxidation of wastewater from molasses fermentation with ozone.

Color removal from biologically pre-treated molasses wastewater by means of chemical oxidation with ozone has been investigated. Batch experiments have been performed in order to analyze the influence of ozone dosage and reaction time on color removal, molecular weight distribution and decolorization kinetics. Depending on the applied ozone dosage, color removal from 71% to 93% and COD reduction from 15% to 25% were reached after 30 min reaction time. TOC values remained constant throughout ozonation. Gel permeation chromatography corroborated that high molecular weight compounds, responsible for the brown color, were present in raw wastewater. UV spectral studies confirmed that these colored compounds were melanoidins. As a result of ozonation the concentration of chromophore groups decreased. Ozonation of synthetic melanoidin under the same experimental conditions provided similar color removal efficiencies. Pseudo-first order kinetics with respect to colored compounds were found.

Fermentation↗
PubMed2002

Aprotinin mediated antioxidant effect in Cardiosurgery with mechanical cardiorespiratory support (CMCS).

BACKGROUND: Aprotinin has been used in cardiosurgery as a hemostatic agent. Considering the implication of oxygen reactive species and proteases in the pathogenesis of Systemic Inflammatory Response Syndrome, we hypothesized that aprotinin may exert an antioxidant effect. This work was designed to evaluate the antioxidant capacity of aprotinin in vitro and in vivo in child patients undergoing cardiosurgery with mechanical cardiorespiratory support. METHODS: Colorimetric techniques and chemiluminiscent emission assays. A blind controlled clinical trial was performed with a control (G-1, n=14, without aprotinin) and treated with aprotinin (G-2, n=12) groups (both assessed by medical decision) of child patients undergoing cardiosurgery with mechanical cardiorespiratory support. Blood samples were taken at: T-0 (induction of anesthesia), T-1 (10 minutes after begining of perfusion), T-2 (5 minutes after anoxic heart arrest), T-3 (ending operation) and T-4 (24 hours after operation). RESULTS: We proved that aprotinin has no hydroxyl radical, superoxide anion nor H2O2 scavenger capacity as well as its capacity for inhibiting in vitro activated-leukocyte chemiluminiscence. Malonildialdehyde levels were higher in G-1 than G-2 with the greatest difference at T-2 (7.2+/-3.6 nmol/ml in G-1 vs 4+/-1.65 in G-2). Phospholipase A2 activity showed a tendency of higher values in G-1 than G-2 although there was no statistical significance. Uric acid concentration was greater in G-2 at T-1, T-2, T-3 and T-4 than G-1 and catalase activity was higher in G-2 at T-0, T-2 and T-3 than G-1 with noteworthy difference only at 5 minutes after anoxic heart arrest. Low cardiac output, arrhythmias and sudden death in the early postoperative phase were less frequent in the treated group. CONCLUSIONS: These results suggest that aprotinin exerts a primary antioxidant activity and its protective effects in cardiosurgery seem to be associated with reduction of systemic oxidative stress.

Antioxidants↗
PubMed2001

Biodegradation of phenolic industrial wastewater in a fluidized bed bioreactor with immobilized cells of Pseudomonas putida.

The paper presents the main results obtained from the study of the biodegradation of phenolic industrial wastewaters by a pure culture of immobilized cells of Pseudomonas putida ATCC 17484. The experiments were carried out in batch and continuous mode. The maximum degradation capacity and the influence of the adaptation of the microorganism to the substrate were studied in batch mode. Industrial wastewater with a phenol concentration of 1000 mg/l was degraded when the microorganism was adapted to the toxic chemical. The presence in the wastewater of compounds other than phenol was noted and it was found that Pseudomonas putida was able to degrade these compounds. In continuous mode, a fluidized-bed bioreactor was operated and the influence of the organic loading rate on the removal efficiency of phenol was studied. The bioreactor showed phenol degradation efficiencies higher than 90%, even for a phenol loading rate of 0.5 g phenol/ld (corresponding to 0.54 g TOC/ld).

Biodegradation, Environmental↗
PubMed2001

Effects of socioeconomic status on the obesity knowledge of adolescents from six Latin American cities.

OBJECTIVE: To examine the effects of socioeconomic status (SES) on the obesity knowledge of adolescents in six Latin American cities. DESIGN: Data were collected using an anonymous, self-administered questionnaire consisting of demographic questions and a 25-item multiple-choice obesity knowledge test. Test items were clustered under five topics: the fat and calorie content of foods and beverages; weight loss methods; energy expenditure; food preparation methods; and the relationship between obesity and health. SUBJECTS: A total of 1272 ninth grade students from higher and lower SES families were recruited at schools in Buenos Aires, Argentina (n=195); Guatemala City, Guatemala (n=212); Havana, Cuba (n=213); Lima, Peru (n=218); Panama City, Panama (n=195); and Santiago, Chile (n=239). RESULTS: Mean test scores reflected a low level of obesity knowledge among adolescents from higher and lower SES groups in all six cities. Nevertheless, a trend for higher scores emerged in favor of adolescents from wealthier families. This income effect persisted after controlling for gender and weight status. The weakest knowledge areas among youth from the higher SES groups were food preparation methods and the relationship between obesity and health while those for adolescents from the lower SES groups were the fat and calorie content of foods and beverages and the relationship between obesity and health. Classroom instruction about obesity was generally more available to students from the higher SES groups. The majority of adolescents from both SES groups were interested in learning more about weight loss methods, energy expenditure, and the fat and calorie content of foods and beverages. The topic of least interest was the relationship between obesity and health. CONCLUSION: These preliminary findings suggest a need for more obesity education programs for adolescents, especially for those living in poverty.

Adolescent↗
PubMed2001

Poststreptococcal reactive arthritis in adults: long-term follow-up.

BACKGROUND: Poststreptococcal reactive arthritis (PSReA) is a recognized inflammatory articular syndrome that follows group A streptococcal infection in persons not fulfilling the Jones criteria for the diagnosis of acute rheumatic fever. Characteristic features include nonmigratory arthritis, lack of response to aspirin or nonsteroidal anti-inflammatory agents, and the presence of extra-articular manifestations, including vasculitis and glomerulonephritis. Whether or not patients with PSReA develop carditis is a point of contention. METHODS: We analyzed the clinical features, laboratory findings, response to therapy, and outcome in patients diagnosed with PSReA between 1983 and 1998 and observed through April 2000. All patients were contacted, reexamined, and repeat antistreptolysin, rheumatoid factor, C3 and C4 complement components, and echocardiograms were performed. RESULTS: Seventeen patients (4 men and 13 women) were included. All were of low socioeconomic status. All patients had acute severe arthritis that began shortly after a sore throat episode. Extra-articular involvement including tenosynovitis, vasculitis, and glomerulonephritis was relatively common. More importantly, none exhibited clinical and/or echocardiographic evidence of cardiac involvement. Longterm antibiotic therapy was not given. CONCLUSION: Cardiac involvement did not occur in this group of patients with PSReA. Prolonged prophylactic antibiotic therapy may not be required for adult patients presenting with PSReA.

Adolescent↗
PubMed2000

Perioperative airway complications following pharyngeal flap palatoplasty.

This study was performed to determine the incidence and types of perioperative airway complications after pharyngeal flap palatoplasty. We conducted a retrospective chart review of 88 patients who underwent correction of velopharyngeal insufficiency between April 30, 1983, and April 30, 1997, in a tertiary care hospital. Some degree of airway obstruction developed in 7 patients. One child developed laryngobronchospasm and required immediate endotracheal intubation. He was successfully extubated without sequelae. Another patient developed severe obstructive sleep apnea and required flap revision. A third patient was found asystolic and apneic. She was immediately intubated; however, she subsequently died. Two patients aspirated blood, presumably resulting in pneumonia. They were managed with parenteral antibiotics. Another child developed worsening sleep apnea and required flap revision. One patient developed nasal obstruction that resolved with time. Airway compromise in patients who undergo pharyngeal flap palatoplasty can be a potentially fatal complication. Careful surveillance should be maintained over patients with underlying neurologic, craniofacial, or cardiopulmonary disorders.

Adolescent↗
PubMed1999

The effect of sleep state on electroretinographic (ERG) activity during early human development.

To assess the effects of sleep state on human retinal electric responses, full-field electroretinograms were obtained in a cross-sectional study from 123 preterm infants at 36, 40 and 56 weeks of post-gestational age. At each age, electroretinographic recordings were assigned to one of two groups according to whether the infants were in active sleep or quiet sleep. Both sleep states were determined behaviorally. Pure rod, maximal, 30 Hz flicker and light adapted single cone responses were evaluated when a sleep state was clearly established. Peak-to-peak amplitudes of most electroretinographic responses were significantly larger in active sleep relative to quiet sleep at 36 and 40 weeks of post-gestational age. We speculate that larger amplitudes during active sleep may play a role in the maturation of the visual system.

Age Factors↗
PubMed1999

Lime-treated maize husks lower plasma LDL-cholesterol levels in normal and hypercholesterolaemic adult men from northern Mexico.

Lime-treated maize husks (LTCH), a by-product of tortilla manufacturing in Mexico, have been shown to decrease plasma LDL-cholesterol levels in guinea-pigs by specific alterations in hepatic cholesterol metabolism. To determine whether LTCH would also lower plasma cholesterol levels in normal and hyperlipidaemic individuals, the fibre content of a typical diet was increased by supplementing free-living subjects in North-West Mexico with cookies containing 450 g LTCH/kg. Normal subjects (n 11) with plasma cholesterol levels of less than 5.7 mmol/l and hypercholesterolaemic subjects (n 12) with plasma cholesterol levels higher than 5.7 mmol/l participated in the study. Plasma glucose, cholesterol, triacylglycerol, LDL-cholesterol and HDL-cholesterol concentrations, LDL:HDL values and blood pressure were determined at baseline and after 6 weeks of supplementation with LTCH. LTCH supplementation significantly lowered the plasma total cholesterol level by 11-15% and LDL-cholesterol by 25%, and improved the LDL:HDL value by 29-33% (P < 0.01) in both normal and hypercholesterolaemic subjects. HDL-cholesterol, triacylglycerol and glucose concentrations did not change. Both groups consumed equal amounts of LTCH per week; individuals showed excellent compliance and good acceptance of the product. Neither group changed their dietary habits during the time of the experiment as determined by 3 d dietary records at baseline and at week 6. We conclude that LTCH supplements are suitable to increase fibre intake and reduce plasma LDL-cholesterol levels in healthy and hypercholesterolaemic subjects in this population.

Adult↗