Suitability of the microbial community composition and function in a semiarid mine soil for assessing phytomanagement practices based on mycorrhizal inoculation and amendment addition.

The recovery of species composition and functions of soil microbial community of degraded lands is crucial in order to guarantee the long-term self-sustainability of the ecosystems. A field experiment was carried out to test the influence of combining fermented sugar beet residue (SBR) addition and inoculation with the arbuscular mycorrhizal (AM) fungus Funneliformis mosseae on the plant growth parameters and microbial community composition and function in the rhizosphere of two autochthonous plant species (Dorycnium pentaphyllum L. and Asteriscus maritimus L.) growing in a semiarid soil contaminated by heavy metals. We analysed the phospholipid fatty acids (PLFAs), neutral lipids fatty acids (NLFAs) and enzyme activities to study the soil microbial community composition and function, respectively. The combined treatment was not effective for increasing plant growth. The SBR promoted the growth of both plant species, whilst the AM fungus was effective only for D. pentaphyllum. The effect of the treatments on plant growth was linked to shifts in the rhizosphere microbial community composition and function. The highest increase in dehydrogenase and ß-glucosidase activities was recorded in SBR-amended soil. The SBR increased the abundance of marker PLFAs for saprophytic fungi, Gram+ and Gram- bacteria and actinobacteria, whereas the AM fungus enhanced the abundance of AM fungi-related NLFA and marker PLFAs for Gram- bacteria. Measurement of the soil microbial community composition and function was useful to assess the success of phytomanagement technologies in a semiarid, contaminated soil.

Effects of storage temperature and length of the storage period on hatchability and performance of red-legged partridge (Alectoris rufa) eggs.

The aim of the present study was to investigate, in red-legged partridge (Alectoris rufa) eggs, the effects of 7- and 42-d storage periods with different storage temperatures (15, 12, and 9°C) on egg weight loss, hatchability, chick weight at hatch, incubation length, and development stage at embryonic mortality. A total of 420 red-legged partridge eggs were arranged in a 2 × 3 factorial design with 2 levels of storage length and 3 levels of storage temperature, resulting in 6 treatments consisting of 10 replications of 7 eggs each. We found that the storage length significantly reduced hatchability of the fertile eggs (P = 0.001), increasing late embryonic mortality (P = 0.001). Storage temperature did not influence on the embryonic mortality at any stage (P > 0.05). Egg weight loss during storage increased with the storage length (P < 0.001), storage temperature (P < 0.001), and their interaction (P < 0.001). Incubation length increased with the storage length (P < 0.001); however, it was not influenced by the storage temperature (P > 0.05). Nevertheless, incubation period decreased with the storage temperature for 7-d storage, and increased with the storage temperature for 42-d storage (P = 0.005). It can be concluded that in this study red-legged partridge eggs stored well with little deterioration up to 42 d at 9 and 12°C and 80% RH, in contrast to the lesser durability of eggs described in the literature for other poultry species. In case of 7-d storage periods, hatchability of A. rufa fertile eggs is higher when they are stored at 15°C. These findings are useful to address specific demands of game farms that require fertile eggs for hatching whose shelf-life should be long enough to maintain hatchability until further incubation. And, due to the marked reproductive seasonality of red-legged partridge, long-term storage of hatching eggs could permit the distribution of batches of chicks throughout the year.

Selective shifts in the rhizosphere microbiome during the drought season could explain the success of the invader Nicotiana glauca in semiarid ecosystems.

The rhizosphere microbiome plays a crucial role in the ability of plants to colonize and thrive in stressful conditions such as drought, which could be decisive for the success of exotic plant invasion in the context of global climate change. The aim of this investigation was to examine differences in the composition, structure, and functional traits of the microbial community of the invader Nicotiana glauca R.C. Graham and native species growing at seven different Mediterranean semiarid locations under two distinct levels of water availability, corresponding to the wet and dry seasons. The results show that the phylum Actinobacteriota was an indicator phylum of the dry season as well as for the community of N. glauca. The dominant indicator bacterial families of the dry season were 67-14 (unclassified family), Pseudonocardiaceae, and Sphingomonadaceae, being relatively more abundant in the invasive rhizosphere. The relative abundances of the indicator fungal families Aspergillaceae (particularly the indicator genus Aspergillus), Glomeraceae, and Claroideoglomeraceae were higher in the invasive rhizosphere. The relative abundance of mycorrhizal fungi was higher in the invasive rhizosphere in the dry season (by about 40 % in comparison to that of native plants), without significant differences between invasive and native plants in the wet season. Bacterial potential functional traits related to energy and precursor metabolites production and also biosynthesis of cell wall, cofactors, vitamins, and amino acids as well as catabolic enzymes involved in the P cycle prevailed in the invasive rhizosphere under drought conditions. This study shows that the pronounced and beneficial shifts in the microbiome assembly and functions in the rhizosphere of N. glauca under conditions of low soil water availability can represent a clear advantage for its establishment.

Synergistic enhancement of the phytostabilization of a semiarid mine tailing by a combination of organic amendment and native microorganisms (Funneliformis mosseae and Bacillus cereus).

The goal of this work was to evaluate the effects of fermented sugar beet residue and inoculation with a native arbuscular mycorrhizal (AM) fungus, Funneliformis mosseae (Nicol. and Gerd.) Gerd. and Trappe, or a native bacterium, Bacillus cereus Frankland & Frankland, alone or in combination, on the establishment of Lygeum spartum L. seedlings grown in a mine tailing under semiarid conditions. We conducted a field study to analyse root and shoot dry biomass, shoot nutrient contents, mycorrhization, plant nitrate reductase (NR) and acid phosphomonoesterase activities, soil enzyme activities and aggregate stability. Ten months after field transplanting, it was found that the three experimental factors had interacted synergistically with regard to shoot and root biomass, with increases of about 410% and 370%, respectively relative to plants in the untreated soil. The treatment combining all three factors increased the root content of all heavy metals, and the levels of nitrogen (N), phosphorus, potassium and NR activity in shoot tissues, whereas it decreased root acid phosphomonoesterase activity. Soil dehydrogenase, protease and ß-glucosidase activities, total N content and aggregate stability were increased by the combined treatment. In conclusion, the combination of the organic amendment, the native AM fungus and the native bacterium can be regarded as a suitable tool for phytostabilization with L. spartum due to its ability to enhance the tolerance of plants to heavy metals, improve the plant nutritional status and increase the soil microbial function related to the C cycling.

Effects of water stress, organic amendment and mycorrhizal inoculation on soil microbial community structure and activity during the establishment of two heavy metal-tolerant native plant species.

Our aim was to examine the effect of water stress on plant growth and development of two native plant species (Tetraclinis articulata and Crithmum maritimum) and on microbial community composition and activity in the rhizosphere soil, following the addition of an organic amendment, namely sugar beet residue (SBR), and/or the inoculation with an arbuscular mycorrhizal (AM) fungus, namely Glomus mosseae, in a non-sterile heavy metal-polluted soil. The AM inoculation did not have any significant effect on plant growth of both species. In T. articulata, SBR increased shoot growth, foliar P, total phospholipid fatty acids (PLFA), fungi-related PLFA, AM fungi-related neutral lipid fatty acid, bacterial gram-positive/gram-negative PLFA ratio and the ß-glucosidase and dehydrogenase activities. SBR and AM inoculation increased phosphatase activity in T. articulata plants grown under drought conditions. In both plants, there was a synergistic effect between AM inoculation and SBR on mycorrhizal colonisation under drought conditions. In C. maritimum, the increase produced by the SBR on total amounts of PLFA, bacterial gram-positive-related PLFA and bacterial gram-negative-related PLFA was considerably higher under drought conditions. Our results suggest that the effectiveness of the amendment with regard to stimulating microbial communities and plant growth was largely limited by drought, particularly for plant species with a low degree of mycorrhizal colonisation.

Elevated functional versatility of the soil microbial community associated with the invader Carpobrotus edulis across a broad geographical scale.

Exotic invasive plants may shape their own rhizosphere microbial community during global invasions. Nevertheless, the impacts of such plant invasions on the functional capacities of soil microbial communities remain poorly explored. We used an approach at a broad geographical scale to estimate the composition and abundance of the fungal functional groups, as well as the bacterial metabolic functions, associated with the rhizospheres of Carpobrotus edulis (L.) L. Bolus and the predominant native plants in coastal ecosystems located in different geographical regions. We used the ASV method to infer the potential functions of the soil microbial community with the PICRUSt2 and FUNGuild tools. The predictive functional profiling of the bacterial communities differed between the rhizospheres of the invasive and native plants, regardless of the biogeographic location of the invaded soil. Some predicted pathways related to the biosynthesis of nucleotides such as ppGpp and pppGpp, lipids, carbohydrates and secondary metabolites and the degradation of organic matter were enriched in the C. edulis rhizosphere. Moreover, the invasive microbiota was characterised by a greater richness and diversity of catabolic enzymes involved in nutrients cycling and higher relative abundances of saprotrophs and pathotrophs. Invasion by C. edulis promoted a shift in the potential functional versatility of the soil microbial communities, which can cope with nutrient limitations and biotic stress, and can favour the establishment of the invasive plant, but also alter the functioning and stability of the invaded ecosystems.

[Insulin resistance in chronic kidney disease: its clinical characteristics and prognosis significance]. / Resistencia a la insulina en la enfermedad renal crónica: características clínicas asociadas y significado pronóstico.

INTRODUCTION: Insulin resistance (IR) increases significantly the risk for cardiovascular disease (CV) in the general population. IR is a common metabolic disorder in patients with chronic kidney disease (CKD). However, the influence of IR on the evolution of CKD patients has scarcely been studied. OBJECTIVE: This study aims to determine whether IR is associated with the progression of CKD, the development of new CV events, or all-cause mortality of non-diabetic patients with CKD stage 4 or 5 not yet on dialysis. MATERIAL AND METHODS: The study group consisted of 365 non-diabetic patients (63 ± 16 year, 169 females) with GFR < 30 ml/min. The degree of IR was estimated by the Homeostasis Model Assessment parameter (HOMA). The outcome measures were: progression of CKD (composite of initiation of dialysis or doubling of baseline serum creatinine level), new cardiovascular events, and all-cause mortality. Unadjusted and multivariable-adjusted relative risks were calculated for HOMA either as a continuous or qualitative variable (tertiles), using Cox proportional hazards models. RESULTS: Mean HOMA value (± SD) was 4.28 ± 2.07. HOMA values correlated significantly with body mass index (beta = 0.37; p < 0.0001), plasma triglycerides (beta = 0.22; p < 0.0001), plasma albumin (beta = 0.19; p = 0.007), and serum phosphate (beta = 0.17; p = 0.031). Progression of CKD was observed in 234 patients (64%) with a median follow-up of 542 days. Patients with HOMA values in the lower tertile (< 3.13) showed a slower progression of CKD than that of the rest of study patients (log rank 4.16, p < 0.05). In adjusted models for age, sex, baseline GFR, body mass index, and proteinuria, HOMA values in the lower tertile entered as an independent variable in the best predictive equation for progression of CKD (HR 0.72, p < 0.03). Fifty-one patients developed a new CV event and 103 patients died during the study period (median follow-up of 1,103 days). HOMA did not relate to the development of new CV events or all-cause mortality in unadjusted or adjusted models for age, sex, comorbid index, plasma albumin, and C-reactive protein. CONCLUSIONS: In conclusion, progression of renal disease was slower in those non-diabetic CKD patients with low HOMA values; however, HOMA values did not relate to the development of new CV events or all-cause mortality.

The invader Carpobrotus edulis promotes a specific rhizosphere microbiome across globally distributed coastal ecosystems.

The importance of plant-microbe interactions to the success of invasive plants has rarely been studied at a global scale. Carpobrotus edulis (L.) N. E. Br is an aggressive invader in many areas around the world, forming dense mats in coastal environments. In an approach at a large geographical scale, over a wide latitudinal and climatic range, we tested the ability of C. edulis to alter the local bacterial and fungal community structure and microbial activity in eight invaded coastal locations. The factors invasiveness and geographical location had a significant effect on the soil microbiota, the microbial community composition and structure from the rhizosphere of native and C. edulis plants being distinct in every location. The effect of the invader on all the chemical, physico-chemical, and microbiological properties studied depended on the invaded location. The soil bacterial and fungal community composition and structure were related to the soil available nutrients and mean annual rainfall, and those of the soil bacterial community were also linked to the soil respiration and latitude. Overall, our results reveal that the ability of the invader C. edulis to alter soil microbial community structure harboring a specific microbiome was widespread across a large invaded range - leading to concurring changes in the rhizosphere microbial functioning, such as nutrient cycling.

Short communication: Effect of alphaS1-casein (CSN1S1) and kappa-casein (CSN3) genotypes on milk composition in Murciano-Granadina goats.

The effects of the caprine alpha(S1)-casein (CSN1S1) polymorphisms on milk quality have been widely demonstrated. However, much less is known about the consequences of the kappa-casein (CSN3) genotype on milk composition in goats. Moreover, the occurrence of interactions between CSN3 and CSN1S1 genotypes has not been investigated. In this study, an association analysis between CSN1S1 and CSN3 genotypes and milk quality traits was performed in 89 Murciano-Granadina goats. Total milk yield as well as total protein, fat, solids-not-fat, lactose, alpha(S1)-casein (CSN1S1), and alpha(S2)-casein (CSN1S2) contents were recorded every other month during a whole lactation (316 observations). Data analysis using a linear mixed model for repeated observations revealed no interaction between the CSN1S1 and CSN3 genotypes. With regard to the effect of the CSN3 locus, AB and BB genotypes were significantly associated with higher levels of total casein and protein content compared with the AA CSN3 genotype. In strong contrast with French breeds, the CSN1S1 genotype did not affect protein, casein, and fat concentrations in Murciano-Granadina goats. These results highlight the importance of taking into consideration the CSN3 genotype when performing selection for milk composition in dairy goats.

[Prognostic value of apolipoproteins A and B in the clinical course of patients with chronic kidney disease previous to dialysis]. / Valor pronóstico de las apolipoproteínas A y B en la evolución de los pacientes con enfermedad renal crónica avanzada prediálisis.

Dyslipidemia is a well-established risk factor for cardiovascular diseases in the general population. However, this association is not observed in chronic kidney disease (CKD) patients. This study examines the association between lipid levels, including apolipoproteins A-I and B concentrations, and all-cause mortality or the development of new cardiovascular events in advanced CKD patients not yet on dialysis. This observational prospective historical study included 331 patients with CKD stage 4 or 5 not yet on dialysis. In addition to conventional clinical and biochemical data, total cholesterol, triglycerides, HDL, LDL, apolipoprotein A-I (apo A) and B (apo B) plasma concentrations were measured. Cox proportional hazard models were adjusted for age, sex, comorbidity index, residual renal function, serum albumin, C-reactive protein levels, and treatment with statins. The median follow-up time was 985 days, and during this period 105 patients died and 54 patients had a new cardiovascular event. In fully-adjusted fixed-covariate Cox models, the hazard ratio for each 10 mg/dl increase of apo A concentration was 0.915 (C.I. 95% 0.844 to 0.992; p=0,031). Patients with an apo A /apo B ratio in the upper tertile (i.e. > 1.42) had a better survival than that of the rest of study patients (hazard ratio = 0.592, C.I. 95% 0.368 to 0.953, p<0.05). None of the study lipid parameters was associated with new cardiovascular events in the adjusted models. In conclusion, apo A concentrations and high apo A / apo B ratios added independent predictive information about survival of CKD patients not yet on dialysis.

[Unawareness of the K/DOQI guidelines for bone and mineral metabolism in predialysis chronic kidney disease: results of the OSERCE Spanish multicenter-study survey]. / Desconocimiento de las guías K/DOQI sobre la alteración del metabolismo óseo-mineral asociada a la enfermedad renal crónica no en diálisis: resultados de la encuesta en el estudio multicéntrico español OSERCE.

Since its publication in 2003, the K/DOQI clinical practice guidelines for bone metabolism and disease in chronic kidney disease (CKD) have become a worldwide reference. The aim of this study was to analyze the observance to these guidelines in patients with a glomerular filtration rate < 60 ml/min/1,73m2 not yet included in dialysis in a Spanish multicenter cohort. A questionnaire by investigator/centre was completed by 32 different nephrologists participating in the OSERCE study and representing the overall Spanish public health net. We observed that biochemical parameters were measured less frequently than recommended, except in CKD stage 3. The therapeutic goals for intact PTH were not properly reported by 59 % of the consulted nephrologists for stages 3 and 4, whereas only 22% did not report them properly for stage 5. The goals for phosphorus were not adequately reported in 50 % of cases (stages 3 y 4) and 60 % (stage 5). For calcium, these values were 70 %, 73.3 % and 65.5 % for stages 3, 4 and 5, respectively. A corrected plasma calcium between 9.5 and 10.2 mg/dl is still considered adequate for 31%. As much as 87% nephrologists stated that they did not sistematically measure calcidiol plasma levels. In general, these results demonstrate that there is a great degree of unawareness of K/DOQITM predialysis guidelines. Thus, their poor implementation is probably not only due to the lower availability of approved therapeutic agents, the difficult achievement of goals or the disbelief on current recommendations. It would be desirable that forthcoming guidelines such as the KDIGO could also consider the need of educational efforts for CKD-Mineral and Bone Disorder.

Impact of DOM from composted "alperujo" on soil structure, AM fungi, microbial activity and growth of Medicago sativa.

Water-soluble extracts from compost may represent an alternative nutrient and organic matter source for crop production under drip irrigation. Dissolved organic matter (DOM), extracted from composted "alperujo", the main by-product from the Spanish olive oil industry, was applied to soil alone or in combination with either Glomus intraradices Schenck and Smith or a mixture of G. intraradices, Glomus deserticola (Trappe, Bloss. and Menge) and Glomus mosseae (Nicol and Gerd.) Gerd. and Trappe. Response measurements included mycorrhizal colonisation, nutrient uptake and growth of Medicago sativa and microbiological and physical properties in the rhizosphere. Dissolved organic matter was added to soil at concentrations of 0, 50, 100 or 300mgCkg(-1) substrate. During the four months of the experiment, the plants were harvested three times. Both mycorrhizal inoculation treatments significantly increased soil aggregate stability. Only the mycorrhizal inoculations increased microbial biomass C and protease and phosphatase activities and decreased water-soluble C, particularly the mixture of arbuscular mycorrhizal fungi. At the third harvest, the greatest increase in growth of M. sativa was observed in the inoculated plants with shoot biomass being 38% greater than for plants grown in the soil amended with the highest dose of DOM and 57% greater than for control plants. The addition of DOM was not sufficient to restore soil structure and microbial activity and did not affect the mycorrhizal development of introduced populations of arbuscular mycorrhizal fungi, but, depending on the dose, its fertiliser efficiency for improving plant growth was apparent.

The unspecificity of the relationships between the invasive Pennisetum setaceum and mycorrhizal fungi may provide advantages during its establishment at semiarid Mediterranean sites.

The involvement of mutualistic plant-fungal interactions in invasion processes, especially in some climatic regions including semiarid areas, has not been sufficiently investigated. We compared the arbuscular mycorrhizal fungi (AMF) communities hosted by the invasive plant Pennisetum setaceum with those from the co-occurring native Hyparrhenia hirta at five Mediterranean semiarid locations with different edaphic characteristics. Illumina technology was used to investigate the AMF communities in the roots. The subsequent multivariate analysis showed that native and non-native host plants shared a similar AMF community, whereas the invaded locations differed in AMF communities harbored in the plant roots. The indicator species analysis revealed the absence of indicator virtual taxa for the fungal communities of the roots of native or invasive plants. In contrast, different numbers of indicator species were recorded in different sampling locations. According to the canonical correspondence analysis, the variability in the AMF communities between sampling sites was related to changes in soil total carbon, electrical conductivity, respiration, and protease and urease activities. These findings reveal the unspecificity of P. setaceum in relation to its association with the AMF community encountered in the invaded locations, which could have facilitated its successful establishment and spread.

[Either calcium carbonate or sevelamer decreases urinary oxalate excretion in chronic renal failure patients]. / Carbonato cálcico o sevelamer reducen la excreción urinaria de oxalato en pacientes con insuficiencia renal avanzada.

The rate of oxalate absorbed from intestine is highly influenced by calcium intake in healthy subjects. It is unknown whether commonly used phosphate binders modify intestinal absorption and renal excretion of oxalate in chronic kidney disease (CKD) patients. This study aims to determine if calcium carbonate or sevelamer influences on urinary oxalate excretion. Twenty patients with CKD (stage 4 and 5 pre-dialysis) were included. Two treatment (1500 mg of calcium carbonate or 2400 mg of sevelamer), two-period (21 days each), crossover study with balanced assignment of the order of administration, and two washout periods were the main characteristics of this study design. Laboratory analyses in each phase included: serum creatinine, calcium, phosphorus, bicarbonate, total cholesterol, and 24 h urinary excretion of oxalate, creatinine, and urea. Creatinine clearance, protein catabolic rate (PNNA), total urinary oxalate excretion, and urinary oxalate / creatinine ratio were determined. Seventeen patients completed both treatment sequences. Total urinary oxalate excretion and urinary oxalate / creatinine ratios decreased significantly with respect to washout periods either after sevelamer or calcium carbonate treatment. The decrease in urinary oxalate excretion was greater after calcium carbonate (41.2+/-17.4%) than after sevelamer treatment (30.4+/-23.8%). There were not significant changes in renal function or PNNA values throughout the study periods. In conclusion, either calcium carbonate or sevelamer significantly reduces urinary oxalate excretion in CKD patients. Further studies will be needed to ascertain whether the type of phosphate binder influences on the accumulation of oxalate in CKD patients.

Arbuscular mycorrhizal fungi inoculation mediated changes in rhizosphere bacterial community structure while promoting revegetation in a semiarid ecosystem.

The main goal of this study was to assess the effect of the inoculation of four autochthonous shrub species with the arbuscular mycorrhizal (AM) fungus Rhizophagus intraradices on the rhizosphere bacterial community and to ascertain whether such an effect is dependent on the host plant species. Additionally, analysis of rhizosphere soil chemical and biochemical properties was performed to find relationships between them and the rhizosphere bacterial communities. Non-metric multidimensional scaling analysis and subsequent permutational multivariate analysis of variance revealed differences in bacterial community composition and structure between non-inoculated and inoculated rhizospheres. Moreover, an influence of the plant species was observed. Different bacterial groups were found to be indicator taxonomic groups of non-inoculated and inoculated rhizospheres, Gemmatimonadetes and Anaerolineaceae, respectively, being the most notable indicators. As shown by distance based redundancy analysis, the shifts in bacterial community composition and structure mediated by the inoculation with the AM fungus were mainly related to changes in plant nutrients and growth parameters, such as the shoot phosphorus content. Our findings suggest that the AM fungal inoculum was able to modify the rhizosphere bacterial community assemblage while improving the host plant performance.

Arbuscular mycorrhizal fungal assemblages in biological crusts from a Neotropical savanna are not related to the dominant perennial Trachypogon.

Knowledge of the arbuscular mycorrhizal fungal assemblages in the Trachypogon savanna ecosystems is very important to a better understanding of the ecological processes mediated by this soil microbial group that affects multiple ecosystem functions. Considering the hypothesis that the biocrusts can be linked to vegetation through the arbuscular fungi mycelial network, the objectives proposed in this study were to determine (i) whether there are arbuscular mycorrhizal fungi (AMF) in the biocrusts (ii) whether arbuscular mycorrhizal fungal assemblages are linked to the Trachypogon patches, and (iii) whether the composition of the assemblages is related to soil properties affected by microbiological activity. The community structure of the AMF was investigated in three habitats: rhizospheric soil and roots of Trachypogon vestitus, biological soil crusts, and bare soil. The canonical correspondence analysis showed that two soil properties related to enzymatic activity (protease and ß-glucosidase) significantly affected the community composition of the AMF. The biocrusts in the Venezuelan savanna are colonized by an AM fungal community linked to that of the bare soil and significantly different from that hosted by the roots of the surrounding T. vestitus, suggesting that assemblages of AMF in biocrusts might be related more closely to those of annual plant species appearing in favorable conditions.

Evolution of suboptimal renal transplantations: experience of a single Spanish center.

The increase in patients on dialysis awaiting transplantation has led to the use of grafts from suboptimal donors. The aim of this study was to analyze the function of suboptimal grafts. The secondary objectives were to study vascular and urological complications, as well as delayed renal function and acute rejection episodes. The study included 135 transplantations performed over 4 years with 27% of grafts being from suboptimal donors. Early graft loss was 12%, of which 69% were due to vascular thrombosis. These thromboses were more frequent among grafts from suboptimal donors (30% vs 4%, P < .001). There were no significant differences between the groups in the incidence of acute rejection episodes (17% vs 13%) or delayed graft function (14% vs 13%). A greater incidence of urologic complications was observed among recipients of grafts from older donors. The 1-year creatinine clearance was significantly lower among recipients of grafts from older donors (73 +/- 19 vs 51 +/- 14 mL/min, P < .0001). Sequential immunosuppressive therapy resulted in a lack of significant differences in creatinine clearance at 6 months, 1 year, or 2 years after transplantation between suboptimal grafts with cold ischemia greater or less than 20 hours or in warm ischemia greater or less than 60 minutes. Logistic regression analysis showed that the best determinant of graft loss was donor age older than 60 years. Accordingly, grafts from suboptimal donors were more likely to be lost during the first month after transplantation, particularly because of thrombosis, which was not due to a higher degree of technical complexity of the transplant operation.

Microbial processes in the rhizosphere soil of a heavy metals-contaminated Mediterranean salt marsh: a facilitating role of AM fungi.

We investigated the relationship of the zonal pattern followed by the vegetation in a polluted Mediterranean salt marsh, in semiarid south-eastern Spain, with the microbiological and biochemical properties (labile C fractions, oxidoreductases and hydrolases) of the rhizosphere soil of two halophyte species, Arthrocnemum macrostachyum and Sarcocornia fruticosa, and with the degree of arbuscular mycorrhizal (AM) colonisation in their rhizospheres. Levels of plant biomass and cover were inversely related to heavy metal contents and salinity. The concentrations of Fe, Cu, Mn and Pb extracted with DTPA hardly varied among the different zones of the salt marsh. The dehydrogenase and phosphatase activities, the soluble C and water-soluble carbohydrates concentrations and the extent of root colonisation were greater in the salt marsh zones of lower soil salinity and lower metal concentration. Urease and beta-glucosidase activities were not detected in the salt marsh. Plant biomass and cover showed positive relationships with mycorrhizal colonisation (R=0.773, P<0.001; R=0.874, P<0.001, respectively). Mycorrhizal colonisation was negatively correlated with the contents of Pb and Zn in plant tissues. This work supports the view that reduced plant uptake of toxic metals, particularly lead, could be involved in the beneficial effects of AM fungi on plant development in Mediterranean salt marshes contaminated with mining wastes.

[Accuracy of indirect estimates of renal function in advanced chronic renal failure patients]. / Exactitud de las estimaciones indirectas del filtrado glomerular en la insuficiencia renal avanzada.

Cockcroft-Gault (CG) and Modification of Diet in Renal Disease (MDRD) formula are indirect estimates of renal function which have been widely accepted, though their accuracies have been scarcely validated in advanced chronic renal failure. The purpose of this study was to determine the accuracy (bias and precision) of these formulas in advanced CRF patients. The study group consisted of 99 unselected patients (62 +/- 15 years, 59 females) with advanced CRF. The glomerular filtration rate (GFR) was measured by Tc(99m) DTPA. Simultaneously, estimates of GFR by CG corrected for 1.73 m2 and MDRD (formula 7) were calculated. Agreement was evaluated graphically, bias was assessed by mean and median difference, and precision by median absolute differences and Bland-Altman plots. Mean GFR by DTPA, CG and MDRD were: 16.24 +/- 4.38 and 16.77 +/- 4.65 and 13.58 +/- 4.27 ml/min/1.73 m2, respectively. MDRD equation significantly underestimated GFR-DTPA (p = 0.0001). Both CG and MDRD correlated significantly with GFR-DTPA (R = 0.53 and R = 0.62, respectively). CG formula performed better than the MDRD equation with respect to bias (0.30 vs -3.24 ml/min/1.73 m2, p = 0.0001), and precision (0.58 vs. -3.11 ml/min/1.73 m2, p = 0.0001). By multiple linear regression, the best determinants of the error of the estimation by CC formula were: serum creatinine (beta = -0.58; p < 0.0001), age (beta = -0.62; p < 0.0001), and body mass index (beta = 0.26, p = 0.004), and by MDRD formula were: serum creatinine (beta = -0.38; p < 0.0001), and body mass index (beta = -0.20, p = 0.03). In conclusion, in unselected patients with advanced chronic renal failure, estimates by CC formula were more accurate than those obtained by MDRD formula. Serum creatinine was the main source of error of the estimation of GFR by both formulas, though demographic and anthropometric characteristics influenced as well on their accuracies.

[Cystatin C as estimator of glomerular filtration rate in patients with advanced chronic renal disease]. / Cistatina C como estimador de la función renal en estadios avanzados de enfermedad renal crónica.

Serum cystatin C (CysC) has been shown to be more accurate than serum creatinine (Cr) in estimating renal function, especially in patients with mildmoderate chronic renal failure. However, it is unknown whether CysC provides or not any advantage over Cr in severe chronic renal failure. The aim of this study was to establish the accuracy of CysC in estimating the glomerular filtration rate (GFR) in advanced chronic renal failure patients. The study group consisted of 94 patients (57 females, mean age 61 +/- 16 years) with advanced chronic renal failure. None of them had thyroid dysfunction or was on corticoid treatment. CFR was measured by TC99mDTPA, and simultaneously, serum CysC (particle enhanced immunonephelometry) and Cr (modified Jaffe's kinetic reaction) were also determined. Serum Cr and CysC levels were correlated with GFR, and the influences of age, sex and diabetes on these correlations were analyzed. The predictive value of CysC and Cr to estimate a GFR less than 15 ml/min/1.73 m2 was analyzed by measuring the crea-under-the-curve (AUC) with Receiver-Operating Characteristics (ROC) plots. The mean CFR was 16.49 +/- 4.65 ml/min/1.73 m2. The mean concentrations of Cr and CysC were 4.19 +/- 1.19 mg/L and 3.44 +/- 0.73 mg/L, respectively. Both Cr and CysC correlated significantly with GFR (R = 0.49, p < 0.0001 and R = 0.52, p < 0.0001, respectively). Age and sex influenced on the correlation between Cr and GFR, but these demographic characteristics did not influence on the correlation between CysC and GFR. The AUC for the prediction of a GFR less than 15 ml/min/1.73 m2 with serum Cr was 0.675 (p = 0.004), while with CysC was 0.633 (p = 0.030). In conclusion, both serum Cr and CysC are highly inaccurate markers of renal function in advanced chronic renal failure patients.