Pesticide dissipation and microbial community changes in a biopurification system: influence of the rhizosphere.

The dissipation of atrazine, chlorpyrifos and iprodione in a biopurification system and changes in the microbial and some biological parameters influenced by the rhizosphere of Lolium perenne were studied in a column system packed with an organic biomixture. Three column depths were analyzed for residual pesticides, peroxidase, fluorescein diacetate activity and microbial communities. Fungal colonization was analyzed by confocal laser scanning microscopy to assess the extent of its proliferation in wheat straw. The L. perenne rhizosphere enhanced pesticide dissipation and negligible pesticide residues were detected at 20-30 cm column depth. Atrazine, chlorpyrifos and iprodione removal was 82, 89 and 74% respectively in the first 10 cm depth for columns with vegetal cover. The presence of L. perenne in contaminated columns stimulated peroxidase activity in all three column depth sections. Fluorescein diacetate activity decreased over time in all column sections with the highest values in biomixtures with vegetal cover. Microbial communities, analyzed by PCR-DGGE, were not affected by the pesticide mixture application, presenting high values of similarity (>65%) with and without vegetal cover. Microbial abundance of Actinobacteria varied according to treatment and no clear link was observed. However, bacterial abundance increased over time and was similar with and without vegetal cover. On the other hand, fungal abundance decreased in all sections of columns after 40 days, but an increase was observed in response to pesticide application. Fungal colonization and straw degradation during pesticide dissipation were verified by monitoring the lignin autofluorescence loss.

Immobilization of the white-rot fungus Anthracophyllum discolor to degrade the herbicide atrazine.

Herbicides cause environmental concerns because they are toxic and accumulate in the environment, food products and water supplies. There is a need to develop safe, efficient and economical methods to remove them from the environment, often by biodegradation. Atrazine is such herbicide. White-rot fungi have the ability to degrade herbicides of potential utility. This study formulated a novel pelletized support to immobilize the white-rot fungus Anthracophyllum discolor to improve its capability to degrade the atrazine using a biopurification system (BS). Different proportions of sawdust, starch, corn meal and flaxseed were used to generate three pelletized supports (F1, F2 and F3). In addition, immobilization with coated and uncoated pelletized supports (CPS and UPS, respectively) was assessed. UPS-F1 was determined as the most effective system as it provided high level of manganese peroxidase activity and fungal viability. The half-life (t1/2) of atrazine decreased from 14 to 6 days for the control and inoculated samples respectively. Inoculation with immobilized A. discolor produced an increase in the fungal taxa assessed by DGGE and on phenoloxidase activity determined. The treatment improves atrazine degradation and reduces migration to surface and groundwater.

Estudio del control metabólico en pacientes diabéticos en hemodiálisis crónica: hemoglobina glicosilada, fructosamina y glicemias capilares / Study of metabolic control in diabetic patients on chronic hemodialysis: glycated hemoglobin, fructosamine and capillary glycemia

Background: In conditions that may change red blood cell survival, such as hemodialysis, the accuracy of A1c glycosylated hemoglobin (HbA1c) to assess metabolic control can be hampered. Other glycosylated proteins such as fructosamine, could accomplish the role of HbA1c. Aim: To assess if HbA1c is a good metabolic control parameter in diabetic patients on chronic hemodialysis. To compare fructosamine, HbA1c and serial capillary glucose levels in the same patients. Material and Methods: Patients on hemodialysis three times per week were studied. Twenty one subjects with diabetes mellitus and 10 non-diabetic patients were included (70 percent were male). During a period of 14 days, fasting and post prandial capillary glucose levels were measured. Venous glucose, HbA1c and fructosamine were measured at the onset and completion of the monitoring period. Results: Diabetic patients were older than their non-diabetic counterparts (65 and 47 years respectively, p < 0.04). In diabetic and non-diabetic patients respectively, capillary blood glucose levels were 161 +/- 22 and 104 +/- 51 mg/dl, HbA1c levels were 6.8 +/- 1.2 and 5.4 +/- 0.4 percent and fructosamine levels were 282.0 +/- 126.6 and 154.6 +/- 73 umol/L. In all patients there was a positive correlation between blood glucose, HbA1c (r = 0.78 p < 0.01) and fructosamine (r = 0.52, p 0.02). There was a positive correlation between mean capillary glucose, HbA1c (r = 0.77, p < 0.01) and fructosamine (r = 0.69, p < 0.02). Among diabetic patients, the correlation coefficients between mean capillary glucose levels, HbA1c and fructosamine levels were 0.67 (p < 0.01) and 0.51 (NS), respectively. Conclusions: Among diabetic patients on hemodialysis fructosamine levels are not a better indicator of metabolic control than HbA1c.

Effect of implementing anti-HLA antibody detection by Luminex in the kidney transplant program in Chile.

The development of new highly sensitive, specific technologies to detect HLA antibodies has allowed a better definition of the profile of non-permitted antigens for patients awaiting kidney transplantation. The use of calculated or virtual panel reactive antibodies (CPRA or vPRA) seeks to improve the prediction of positive crossmatches (XM), but increases the proportion of sensitized patients on the waiting list. In 2008-2009, we implemented detection of antibodies using Luminex technology and applied vPRA since 2009. The objective of this study was to evaluate the impact of these innovations in defecting patient sensitization on kidney transplant waiting lists for deceased donors and among transplanted patients. We analyzed the waiting list for 2007 through 2009 and the first semester of 2010, including the patients transplanted in these periods and the XM with deceased donors. We observed an increase in the mean peak PRA of transplanted patients from 7.2% in 2007 to 17.1% in 2010 (P = .001), and in the proportion of patients transplanted with a peak PRA > 50% from 2.8% in 2007 to 15.7% in 2010 (P = .0001), with no increase in the proportion of this population on the waiting lists. There was a concurrent decrease in positive XM among patients with a peak PRA > 50%. The use of vPRA and Luminex permitted a greater number of transplants of patients with peak PRA > 50% and was a good predictor of a positive XM.

Evaluation of the stages involved in cold ischemia time in renal transplants in Chile.

INTRODUCTION: Cold ischemia time (CIT) is one of the factors that determine the evolution of a renal transplant; taking measures to reduce this time requires knowledge of its stages. The objective of this study was to evaluate the times in the stages that determine CIT in renal transplants. METHODS: We analyzed 108 donors and 201 kidney transplantations performed in Chile in 2008, establishing the CIT for the kidney transplanted by the center that extracted the kidneys (local kidney) and for the kidney transplanted in another center (shared kidney). RESULTS: Average CIT was 18.8 hours: namely, 16.9 hours for local and 20.2 hours for shared kidneys (P = .0001484). CIT for cases in which samples were sent to histocompatibility laboratory prior to nephrectomy was 7.3 hours less than for those sent postnephrectomy. The mean time between the allocation of the kidney and the transplant was 7.3 hours; 5.6 hours for local kidneys and 8.4 hours for shared kidneys (P = .000007124). CONCLUSION: We identified the stages at which intervention is possible to reduce the CIT, mainly for shared kidneys. All involved parties should make an effort to reduce this time.

Early and late humoral rejection: a clinicopathologic entity in two times.

Humoral rejection is an important cause of early and late graft loss. The late variant is difficult to diagnose and treat. There is a close correlation between sclerosing nephropathy and anti-HLA antibodies. We analyzed 113 renal allograft recipients between August 2004 and April 2007. Acute humoral rejection was defined as acute graft dysfunction in presence of donor-specific antibodies (DSA) detected by flow panel reactive antibodies (PRA) and/or C4d positive pericapilary tubules (PTC) detected histopathologically by immunofluorescent or immunoperoxidase at less than 3 months postransplantation. Late humoral rejection was defined as dysfunction occurring after 3 months postransplantation with histopathologic glomerulopathy or vasculopathy and positive C4d PTC. We included all patients who were diagnosed with early or late graft dysfunction and underwent biopsy, all of which were examined for C4d. Four patients had acute humoral rejection treated with IVIG or plasmapheresis. The patient and graft survivals were 100% and serum creatinine averaged 1.7 mg/dL. Three recipients experienced late humoral rejection at 3 to 10 years posttransplantation All received high-dose IVIG; one also was treated with thymoglobulin. Immunosuppression was switched to tacrolimus, mycophenolate mofetil, and steroids. Only one patient recovered renal function; the others returned to dialysis. Among seven patients only one had an actual PRA (>20%) and three showed 10% to 20%. However, six had a positive historical PRA of 10% to 50%. In conclusion, Recognition of acute humoral rejection has contributed to graft rescue by controlling alloantibody production through new specific immunosuppressive therapies in contrast with the clinical response to acute therapy, treatment of a chronic entity has shown poor outcomes, probably because antibody mediated chronic graft damage is already present when the late diagnosis is established by biopsy.

Efecto de la midodrina en la hipotensión sintomática en hemodiálisis / Effects of midodrine on orthostatic hypotension during hemodialysis

Background: Hypotension occurs in 20 percent of hemodialysis procedures. Aim: To study the effects of midodrine on hypotension during hemodialysis. Patients and methods: Ten patients on chronic hemodialysis and with a history of hypotension during the procedure, were studied. They received midodrine 10 mg per os or placebo during 5 dialytic procedures each, in a double blind cross over design. Results: Blood pressure levels prior to dialysis were similar during the midodrine or placebo administration periods. During dialysis, systolic blood pressure fell 19.3ñ28 mmHg with midodrine and 23.4ñ28 mmHg with placebo. Diastolic blood pressure fell 7.3ñ11.5 mmHg with midodrine and 11.1ñ12 mmHg with placebo. The reduction in median arterial pressure was also less pronounced with midodrine. Conclusions: Midodrine lessens the fall in arterial pressure during hemodialysis, in patients with symptomatic hypotension

[Measurement of total serum IgE by enzyme immunoassay with three commercial reagents]. / Medición de IgE total en suero por enzimainmunoanálisis con tres reactivos comerciales.

We measured total serum IgE in 14 patients with allergic diseases and 16 healthy subjects, using three commercial ELISA kits. The correlation of results among the three kits was analyzed using Passing and Bablock regression parameters. Results show that measurements of the different kits do not coincide. One kit shows differences using sera from normal subjects. There is no correlation among kits when using sera from allergic patients. It is concluded that it is not possible to determine exactly the amount of IgE using these kits, specially in subjects with elevated levels.

[Pre S1 antigen in different forms of hepatitis B virus infection]. / Antígeno Pre S1 en diferentes formas de infección con el virus de la hepatitis B.

Pre S1 antigen was measured using an ELISA technique in patients with different forms of hepatitis B virus infection. It was detected in 10 of 19 patients with acute hepatitis B (53%), 12 of 15 chronic hepatitis B virus carriers (80%), 9 of 11 patients with chronic hepatitis B (82%) and 3 of 4 patients with hepatoma and positive markers of hepatitis B virus infection. Pre S1 remained positive beyond 150 days in two patients with acute hepatitis that evolved to chronicity. Among subjects with chronic hepatitis B that received interferon, pre S1 antigen negativized only in the patient that had a complete response. Pre S1 detection is an index of hepatitis B virus replication and its persistence determines chronicity. Its negativization after antiviral therapy should have a predictive value.

Hemodiálisis crónica: programa de evaluación de calidad de vida en pacientes mayores de 60 años / Chronic hemodialysis: evaluation programme of life quality in patients over 60 years old

The aim of this work was to assess the quality of life of 87 patients older than 60 years, out of 200 undergoing chronic hemodialysis in 9 centers at Santiago. A visual analog scale, with scores ranging from 0 (bad) to 100 (optimal) and a specific questionnaire about the impact of hemodialysis in daily activities, with scores ranging from 1 -10 (severe limitation) to +10 (no limitation) were applied to patients and their attending nurses. Using the visual analog scale, patients assesed their quality of life in 51.7 per cent and health personnel in 61.3 per cent . Patients had a questionnaire score of 2.3. Quality of life scores were inversely correlated with the condition of being diabetic and the number of hospital admissions

Idiopathic membranous nephropathy, associated with HLA-DRw3 and not related to monocyte-phagocyte system Fc receptor dysfunction, in father and son.

Familial idiopathic membranous nephropathy, an immune-complex-associated glomerulopathy, has not been previously reported in father and son, despite its striking immunogenetic correlation, especially with HLA-DR3. As a dysfunction of the monocyte-phagocyte system (MPS), it has been observed linked to DR3 antigen, so we studied the MPS Fc receptor function in a father and his son with a histologically proven membranous nephropathy, associated with the haplotype A9-B35-DR3-DQw2. The Fc receptor function of the MPS was examined by measuring the clearance of IgG-sensitized, 51Cr-labeled erythrocytes and by measuring the ability of isolated monocytes to ingest autologous red blood cells coated with IgG anti-Rh (D) antibody. Immune clearance and in vitro phagocytosis was normal in both patients and not related to their levels of immune complexes (as measured by ELISA C1q and Conglutinin solid-phase binding assay). This report suggest that genetic factors may play an important role in the development of membranous nephropathy, and it seems not to be related to a dysfunction of MPS as measured by these tests.

Age influence on mononuclear phagocyte system Fc-receptor function in poststreptococcal nephritis.

The Fc-receptor function of the mononuclear phagocyte system (MPS) was examined in 41 children and adult patients, by measuring the clearance of IgG-sensitized, 51Cr-labeled erythrocytes. The Fc-receptor-mediated clearance observed in patients (mean +/- SE) was not significantly different as compared to the control group of similar age distribution. However, the immune clearance time was significantly age-correlated in both groups (acute poststreptococcal glomerulonephritis, APSGN, r = 0.39, p less than 0.05; control r = 0.63, p less than 0.01). The magnitude of the Fc-specific immune clearance and the serum creatinine were also significantly correlated (r = 0.59; p less than 0.01). Circulating immune complexes (as measured by the C1q and conglutinin ELISA) did not correlate with immune clearance, which remained stable in longitudinal studies. Age-related changes in MPS Fc-receptor function could explain, at least in part, prognostic differences between children and adult patients with APSGN.

[B-DR (HLA) linkage imbalance and transplants in Chile: a preliminary report]. / Desequilibrio de ligamento B-DR (HLA) y trasplantes en Chile: comunicación preliminar.

Linkage imbalance for the B and DR loci (HLA) was found in a Chilean sample of families where a member had been proposed for transplantation. The B7-DR2 and B14-DR1 haplotypes were significantly more frequent than expected. Most associations were those found in Caucasian populations.

Lupus eritematoso diseminado en la infancia. Estudio clinico y de sobrevida en 31 casos. / Lupus erythematosus disseminatus in childhood. Clinical study and survival in 31 cases

Se efectuo un analisis clinico y evolutivo de 31 pacientes portadores de lupus eritematoso diseminado (LED) de manera retrospectiva. Todos los sujetos eran a menores de 16 anos de edad y reunian como minimo 4 de los requisitos exigidos por la Academia Reumatologica Americana (ARA) para el diagnostico de la enfermedad.De los 31 pacientes, 26 pertenecieron al sexo femenino y 5 al masculino. Las principales manifestaciones clinicas y de laboratorio fueron semejantes a las descritas para el LED de tipo adulto, predominando las lesiones articulares y cutaneas.Se subraya la contribucion de las nuevas tecnicas inmunologicas en el diagnostico y evolucion de la enfermedad, especialmente de los AAN y AADN. La sobrevida global en nuestros enfermos alcanzo a 68 y 40% en 5 y 10 anos respectivamente, disminuyendo a 57 y 28% en los que sufrian nefropatia lupica. Los enfermos sin lesion renal, tuvieron 90% de sobrevida durante el periodo de observacion de 10 anos. Se analiza el impacto de los distintos tratamientos en la enfermedad y sugiere que el uso de combinaciones de esteroides suprarrenales con inmunosupresores, pudiera reducir la elevada mortalidad observada en estos pacientes