Evaluation of IFN-gamma production by CD8 T lymphocytes in response to the K1 peptide from KMP-11 protein in patients infected with Trypanosoma cruzi

The cellular response mediated by MHC class I restricted CD8+ T cells has been shown to be crucial in the control of Chagas disease. The K1 peptide derived from T. cruzi KMP-11 protein has a high binding affinity to the HLA-A*0201 molecule. Nevertheless, it is not known whether this peptide is processed and displayed as an MHC class I epitope during natural infection by T. cruzi. The aim of this study was to evaluate, by ELISPOT assay, the ability of K1 peptide to activate CD8+ T lymphocytes to produce IFN-gamma. Therefore, CD8+ T lymphocytes from 22 HLA-A*0201+ individuals, 12 chronic chagasic patients and 10 uninfected controls, were analysed. The results revealed that two of the chagasic patients had IFN-gamma-secreting CD8+ T cells that were able to respond to K1 peptide with a relative frequency of 110 and 230 per million CD8+ T cells. In contrast, none of HLA-A*0201+ uninfected controls responded to K1 peptide. Responses to HLA-A*0201 restricted peptide from the influenza matrix protein were found in six chagasic patients and four uninfected controls with an average frequency of 175 and 111 cells per million CD8+ T cells, respectively. Moreover, a flow cytometric assay for degranulation showed that chagasic responders had K1-specific cytotoxic CD8+ T cells. It is shown here for the first time that the K1 peptide is efficiently processed, presented and recognized by CD8+ T lymphocytes during the natural course of Chagas disease.

Phosphorylation and subcellular localization of transmissible gastroenteritis virus nucleocapsid protein in infected cells

The nucleocapsid (N) protein is the only phosphorylated structural protein of the coronavirus Transmissible gastroenteritis virus (TGEV). The phosphorylation state and intracellular distribution of TGEV N protein in infected cells were characterized by a combination of techniques including: (i) subcellular fractionation and analysis of tryptic peptides by two-dimensional nano-liquid chromatography, coupled to ion-trap mass spectrometry; (ii) tandem mass-spectrometry analysis of N protein resolved by SDS-PAGE; (iii) Western blotting using two specific antisera for phosphoserine-containing motifs; and (iv) confocal microscopy. A total of four N protein-derived phosphopeptides were detected in mitochondria–Golgi–endoplasmic reticulum–Golgi intermediate compartment (ERGIC)-enriched fractions, including N-protein phosphoserines 9, 156, 254 and 256. Confocal microscopy showed that the N protein found in mitochondria–Golgi–ERGIC fractions localized within the Golgi–ERGIC compartments and not with mitochondria. Phosphorylated N protein was also present in purified virions, containing at least phosphoserines 156 and 256. Coronavirus N proteins showed a conserved pattern of secondary structural elements, including six β-strands and four α-helices. Whilst serine 9 was present in a non-conserved domain, serines 156, 254 and 256 were localized close to highly conserved secondary structural elements within the central domain of coronavirus N proteins. Serine 156 was highly conserved, whereas no clear homologous sites were found for serines 254 and 256 for other coronavirus N proteins.

Iodinated molecularly imprinted polymer for room temperature phosphorescence optosensing of fluoranthene

A novel molecularly imprinted polymer (MIP) of high interest for room temperature phosphorescence (RTP) sensing systems is described; the synthesized MIP contains iodine as internal heavy atom in the polymeric structure and its applicability for RTP sensing of fluoranthene at microg L(-1) levels is demonstrated.

[Delays in the diagnosis of lung cancer]

OBJECTIVE

To study the clinical and demographic factors associated with delays in the diagnosis of lung cancer.

PATIENTS AND METHODS

A 2-year prospective study of patients admitted to the respiratory medicine ward with a suspected diagnosis of lung cancer. We studied demographic factors, health care received, place of residence, and delays in carrying out diagnostic procedures. The following diagnostic time periods were defined: consultation (from first symptom to first medical visit), middle period (from first medical visit to hospital admission) and diagnostic (from hospital admission to histological diagnosis and clinical staging).

RESULTS

One hundred thirteen patients with a mean age of 65 years (range, 36-90), 103 men and 10 women, were studied. The most frequent symptoms leading to consultation were coughing (10.6%), hemoptysis (19.5%), chest pain (26.5%), and shortness of breath (9.7%). First visits were to a primary care physician for 72%, to the hospital emergency room for 22%, or to a pulmonologist for 6%. Forty-four percent of the patients visited the doctor 2 or 3 times. The mean SD, numbers of days for the different time periods were as follows: consultation, 30.3 60; diagnosis, 18.6 19; middle period 37.9 63. The mean total time from first symptom to diagnosis was 85.7 87 days. The middle period, the time in hospital until diagnosis, and the total time were shorter when patients were referred by the primary care physician to the emergency room or were directly admitted to the hospital (P<.001). Only 25.7% of the staged lung cancers were operable.

CONCLUSIONS

Delays in lung cancer diagnosis are long. The attitudes of primary care physicians and their relations with specialized care providers are crucial for reducing delays.

A comparative sequence analysis to revise the current taxonomy of the family Coronaviridae

The Coronaviridae family, comprising the Coronavirus and Torovirus genera, is part of the Nidovirales order that also includes two other families, Arteriviridae and Roniviridae. Based on genetic and serological relationships, groups 1, 2 and 3 were previously recognized in the Coronavirus genus. In this report we present results of comparative sequence analysis of the spike (S), envelope (E), membrane (M), and nucleoprotein (N) structural proteins, and the two most conserved replicase domains, putative RNA-dependent RNA polymerase (RdRp) and RNA helicase (HEL), aimed at a revision of the Coronaviridae taxonomy. The results of pairwise comparisons involving structural and replicase proteins of the Coronavirus genus were consistent and produced percentages of sequence identities that were distributed in discontinuous clusters. Inter-group pairwise scores formed a single cluster in the lowest percentile. No homologs of the N and E proteins have been found outside coronaviruses, and the only (very) distant homologs of S and M proteins were identified in toroviruses. Intragroup sequence conservation was higher, although for some pairs, especially those from the most diverse group 1, scores were close or even overlapped with those from the intergroup comparisons. Phylogenetic analysis of six proteins using a neighbor-joining algorithm confirmed three coronavirus groups. Comparative sequence analysis of RdRp and HEL domains were extended to include arterivirus and ronivirus homologs. The pairwise scores between sequences of the genera Coronavirus and Torovirus (22–25% and 21–25%) were found to be very close to or overlapped with the value ranges (12 to 22% and 17 to 25%) obtained for interfamily pairwise comparisons, but were much smaller than values derived from pairwise comparisons within the Coronavirus genus (63–71% and 59–67%). Phylogenetic analysis confirmed toroviruses and coronaviruses to be separated by a large distance that is comparable to those between established nidovirus families. Based on comparison of these scores with those derived from analysis of separate ranks of several multi-genera virus families, like the Picornaviridae, a revision of the Coronaviridae taxonomy is proposed. We suggest the Coronavirus and Torovirus genera to be re-defined as two subfamilies within the Coronavirdae or two families within Nidovirales, and the current three informal coronavirus groups to be converted into three genera within the Coronaviridae.

[Optimization of an individualized LASIK surgery. Geometric ray tracing model]

PURPOSE

To develop an objective calculation method that is able to provide a customized surgical correction that allows the patient to reach the emmetropia and the maximum visual acuity after the surgery.

METHODS

The study included 187 eyes with myopia or myopic astigmatism that underwent LASIK. The optical characterization of each eye was developed by a complete theoretical model based in Le Grand eye, in which the measured values of radii and thicknesses of the different surfaces have been substituted. By means of a geometric ray tracing, the surgery has been simulated by changing the anterior corneal radius and the corneal thickness within the optical zone to obtain its influence in the ocular image and the visual acuity. We considered the surgery to be <<satisfactory>> when the residual equivalent refraction was between 0 and +0.5 D.

RESULTS

An interval for the final corneal radius is proposed for each eye in order to reach the best visual acuity (optimal interval). The position of the post-surgical radius in this interval has been related with the success of the surgical process.

CONCLUSIONS

An objective method for LASIK has been proposed: i) it calculates a personalized surgical plan that allows the patient to reach the best visual quality, and ii) it can be used as a reference by the surgeon to design his nomogram and to decrease his learning curve.

The detection, cloning, and characterisation of WIS 2-1A retrotransposon-like sequences in Triticum aestivum L. and xTriticosecale Wittmack and an examination of their evolution in related Triticeae

Retrotransposons and other mobile elements are major components of the repeated DNA fraction in higher-plant genomes. They have undoubtedly played an important role in higher plant genome evolution. The present work details the detection and characterisation of a WIS 2-1A related sequence in direct wheat relatives, and discusses the prevalence and evolution of its copy number in their genomes. An increase in copy number is detected when following the natural hybridisation processes that gave rise to bread and durum wheats. However, the opposite is observed in the development of triticale, a synthetic hybrid.

Cloning and sequence analysis of the LEU2 homologue gene from Pichia anomala

The Pichia anomala LEU2 gene (PaLEU2) was isolated by complementation of a leu2 Saccharomyces cerevisiae mutant. The cloned gene also allowed growth of a Escherichia coli leuB mutant in leucine-lacking medium, indicating that it encodes a product able to complement the beta-isopropylmalate dehydrogenase deficiency of the mutants. The sequenced DNA fragment contains a complete ORF of 1092 bp, and the deduced polypeptide shares significant homologies with the products of the LEU2 genes from S. cerevisiae (84% identity) and other yeast species. A sequence resembling the GC-rich palindrome motif identified in the 5' region of S. cerevisiae LEU2 gene as the binding site for the transcription activating factor encoded by the LEU3 gene was found at the promoter region. In addition, upstream of the PaLEU2 the 3'-terminal half of a gene of the same orientation, encoding a homologue of the S. cerevisiae NFS1/SPL1 gene that encodes a mitochondrial cysteine desulphurase involved in both tRNA processing and mitochondrial metabolism, was found. The genomic organization of the PaNFS1-PaLEU2 gene pair is similar to that found in several other yeast species, including S. cerevisiae and Candida albicans, except that in some of them the LEU2 gene appears in the reverse orientation.

Sociodemographic factors and trends on overweight prevalence in children and adolescents in Aragón (Spain) from 1985 to 1995

From 1985 to 1995, the Aragón School Health Examination Surveys staff has surveyed the whole population of children (age 6-7 years) and adolescents (age 13-14 years). A total of 90,997 children (age 6-7 years) were examined in the nine cross-sectional surveys conducted between 1985 and 1995. A total of 106,284 adolescents (age 13-14 years) were also examined. We defined overweight when the body mass index was > or = 95th percentile. The measure of association between overweight and the other variables studied was the odds ratio, which was calculated by logistic regression. In the children and adolescents studied, the probability to be overweight was higher in the rural than in the urban areas. In the adolescents, the probability to be overweight was higher in the public than in the private schools. Our results also show a significant increase in the prevalence of overweight children in the region of Aragón (Spain) during the 1985-1995 decade, especially in males. Prevention of overweight in the populations at risk would help reduce social inequality in health, a major challenge for public health policy.

Variants of the Plasmodium vivax circumsporozoite protein (VK210 and VK247) in Colombian isolates

Phenotypic diversity has been described in the central repeated region of the circumsporozoite protein (CSP) from Plasmodium vivax. Two sequences VK210 (common) and VK247 (variant) have been found widely distributed in P. vivax isolates from several malaria endemic areas around the world. A third protein variant called P. vivax-like showing a sequence similar to the simian parasite P. simioovale has also been described. Here, using an immunofluorescent test and specific monoclonal antibodies, we assessed the presence of two of these protein variants (VK210 and VK247) in laboratory produced sporozoite. Both sequences were found in parasite isolates coming from different geographic regions of Colombia. Interestingly, sporozoites carrying the VK247 sequence were more frequently produced in Anopheles albimanus than sporozoites with the VK210 sequence. This difference in sporozoites production was statistically significant (p <0.05, Kruskal-Wallis); not correlation was found with parameters as the total number of parasites or gametocytes in blood from human donors used to feed mosquitoes. Previous studies in the same region have shown a higher prevalence of anti-VK210 antibodies which in theory may suggest their role in blocking the development of sporozoites carrying the CSP VK210 sequence.

Relevance of 99mTc-MIBI rest uptake, ejection fraction and location of contractile abnormality in predicting myocardial recovery after revascularization

The aim of this study was to analyse the influence of rest technetium-99m-methoxy-isobutyl-isonitrile (99mTc-MIBI) uptake, left ventricular ejection fraction (EF) and dysfunctional location in the prediction of myocardial viability. Rest 99mTc-MIBI single photon emission computed tomography (SPECT) was analysed in 82 patients (59+/-9 years, 70 men, 12 women) with one or more segments showing severe hypokinesia, akinesia or dyskinesia who had undergone coronary revascularization. Before and within 3-6 months after the revascularization, gated blood pool scintigraphy was performed. In the post-revascularization control, contractile recovery was observed in 48.7% (155/318) of the segments with severe hypokinesia, akinesia or dyskinesia. Significant increases in sensitivity (53%, 72% and 91%, P<0.0001) and negative predictive value (62%, 68% and 79%, P = 0.01) were observed with decreasing rest uptake 99mTc-MIBI levels of 50%, 40% and 30%, respectively. The decrease in specificity was also significant (67%, 53% and 32%, P<0.0001). The negative predictive value was higher than the positive predictive value mainly in patients with EF < or = 0.35 and with anterior dysfunction. In logistic regression analysis, uptake levels and EF were independent variables that influenced sensitivity and specificity. The negative predictive value was influenced by EF and the positive predictive value only by dysfunctional location. This study suggests that the negative predictive value of 99mTc-MIBI SPECT is higher than the positive predictive value, mainly in patients with EF < or = 0.35, and that the rest uptake level, EF and dysfunctional location are factors that must be considered when results of 99mTc-MIBI SPECT are analysed.

Disseminated infection and colonization by Scedosporium prolificans: a review of 18 cases, 1990-1999

Scedosporium prolificans infection was analyzed in 18 patients from whom the fungus was isolated during the period 1990-1999. Of these 18 patients, 12 had some predisposing factor and either unconfirmed infection or colonization, and 6 patients had confirmed disseminated infection: 4 patients with leukemia died, 1 patient with breast cancer who underwent autologous bone marrow transplantation survived, and 1 patient with advanced acquired immunodeficiency syndrome died, although the fungal infection did not seem to affect his clinical symptoms.

Rigid gas permeable contact lens and corneal topography

We investigated the effect of high Dk daily wear rigid gas permeable contact lenses on corneal topography. Eight young myopic subjects wore hard contact lenses for 21 days. Corneal topography was monitored using the EyeSys system. It was measured every day during the next 21 days after the fitting. We recorded the corneal radius of curvature at 16 peripheral points approximately 1, 2, 3 and 4 mm along the four principal meridians (nasal, superior, inferior and temporal). Our study showed that daily wear RGP Forum 210 does not produce significant alterations of the corneal curvature as a function of time.

Determination of physical properties of bitumens by use of near-infrared spectroscopy with neural networks. Joint modelling of linear and non-linear parameters

The fact that bitumens behave as non-Newtonian fluids results in non-linear relationships between their near-infrared (NIR) spectra and the physico-chemical properties that define their consistency (viz. penetration and viscosity). Determining such properties using linear calibration techniques [e.g. partial least-squares regression (PLSR)] entails the previous transformation of the original variables by use of non-linear functions and employing the transformed variables to construct the models. Other properties of bitumens such as density and composition exhibit linear relationships with their NIR spectra. Artificial neural networks (ANNs) enable modelling of systems with a non-linear property-spectrum relationship; also, they allow one to determine several properties of a sample with a single model, so they are effective alternatives to linear calibration methods. In this work, the ability of ANNs simultaneously to determine both linear and non-linear parameters for bitumens without the need previously to transform the original variables was assessed. Based on the results, ANNs allow the simultaneous determination of several linear and non-linear physical properties typical of bitumens.

Evaluation of canine serum thyrotropin (TSH) concentration: comparison of three analytical procedures

A comparative study of 3 analytical methods (immunoradiometric assay, enzyme immunometric assay, and chemiluminescent immunometric assay) for canine serum thyrotropin (TSH) was performed. Ninety-six dogs were included in the study. The within- and between-run precision was evaluated for each method, and correlations for the results obtained with each method were examined. The best within- and between-run precision was obtained with the chemiluminescent immunometric assay. Satisfactory correlations for the 3 analytical procedures were obtained but varied in relation to serum TSH concentration.

[Effects of the statins in kidney transplantation]

A retrospective analysis was performed to assess the immunosuppressive activity of statins in kidney transplantation, determining their effects on serum cholesterol and triglyceride levels post-transplantation, on the incidence of acute rejection episodes and on renal function. A total of 97 patients who underwent a kidney transplant in a three-year period, had more than one-month graft survival, and a minimum of one year of follow-up, were included. Group A consisted of 38 patients who received statins; this group was subsequently divided into four subgroups, according to the time post-transplant when statins were prescribed. Group B consisted of 59 patients (control Group). Initial and final serum total cholesterol levels in Group A were not different (218 +/- 7.8 mg/dl vs 222 +/- 7.5 mg/dl); however, final levels were higher than initial values in Group B (216 +/- 6.0 mg/dl vs 189 +/- 6.4 mg/dl, P = 0.0021). Initial serum triglyceride levels were higher than final levels in Group A (305 +/- 25.5 mg/dl vs 188 +/- 10.6 mg/dl, P < 0.0001). Group A showed a better allograft survival (P = 0.0350), a reduction in the incidence of acute rejection episodes (1 vs 38 events, P < 0.0001) and a lower serum creatinine level (1.96 +/- 0.21 mg/dl vs 2.77 +/- 0.27 mg/dl, P = 0.0374). In Group A subgroups, kidney function was significantly better in patients who received statins early after transplantation. These data suggest that in kidney transplantation statins exert additional immunosuppressive effects, reduce the number of acute rejection episodes, improve allograft survival and kidney function and are effective in preventing serum cholesterol from rising; these effects correlate with a significant decrease in serum triglyceride but are independent of a hypocholesterolemic action.

Experimental results on constructed wetland pilot system

Research into a constructed wetland for wastewater treatment using M.H.E.A. (Hierarchical Mosaic of Artificial Ecosystems) pilot system was carried out over a vegetative period in 8 different flow and vegetable composition series. The system consisted of a free water pond as a first step working as primary treatment followed by a zone with Typha sp. and surface flow and finally a woody zone with a subsurface flow and planted with ligneous species (Salixsp., Populus sp., Fraxinus sp. and Alnus sp.). Removal efficiency in the study reflects an optimal result: 80-99% total suspended matter removal, 82-98% organic matter removal, 70-98% nutrients removal and up to 99.9% faecal bacterial disinfecting. Effluent characteristics were in accordance with European Union legislation criteria for wastewater treatment systems.

Carboxydobrachium pacificum gen. nov., sp. nov., a new anaerobic, thermophilic, CO-utilizing marine bacterium from Okinawa Trough

A new anaerobic, thermophilic, CO-utilizing marine bacterium, strain JMT, was isolated from a submarine hot vent in Okinawa Trough. Cells of strain JMT were non-motile thin straight rods, sometimes branching, with a cell wall of the Gram-positive type, surrounded with an S-layer. Chains of three to five cells were often observed. The isolate grew chemolithotrophically on CO, producing equimolar quantities of H2 and CO2 (according to the equation CO+H2O-->CO2+H2) and organotrophically on peptone, yeast extract, starch, cellobiose, glucose, galactose, fructose and pyruvate, producing H2, acetate and CO2. Growth was observed from 50 to 80 degrees C with an optimum at 70 degrees C. The optimum pH was 6.8-7.1. The optimum concentration of sea salts in the medium was 20.5-25.5 g l(-1). The generation time under optimal conditions was 7.1 h. The DNA G+C content was 33 mol %. Growth of isolate JMT was not inhibited by penicillin, but ampicillin, streptomycin, kanamycin and neomycin completely inhibited growth. The results of 16S rDNA sequence analysis revealed that strain JMT belongs to the Thermoanaerobacter phylogenetic group within the Bacillus-Clostridium subphylum of Gram-positive bacteria but represents a separate branch of this group. On the basis of morphological and physiological features and phylogenetic data, this isolate should be assigned to a new genus, for which the name Carboxydobrachium is proposed. The type species is Carboxydobrachium pacificum; the type strain is JMT (= DSM 12653T).

Genetic analysis of Carboxydothermus hydrogenoformans carbon monoxide dehydrogenase genes cooF and cooS

Carboxydothermus hydrogenoformans is an extremely thermophilic, Gram-positive bacterium growing on carbon monoxide (CO) as single carbon and energy source and producing only H(2) and CO(2). Carbon monoxide dehydrogenase is a key enzyme for CO metabolism. The carbon monoxide dehydrogenase genes cooF and cooS from C. hydrogenoformans were cloned and sequenced. These genes showed the highest similarity to the cooF genes from the archaeon Archaeoglobus fulgidus and the cooS gene from the bacterium Rhodospirillum rubrum, respectively. The cooS gene was identified immediately downstream of cooF, however, the cooF and cooS genes from C. hydrogenoformans have substantially different codon usage, and the cooF gene Arg codon usage pattern, dominated by AGA and AGG, resembles the archaeal pattern. The data therefore suggest lateral transfer of these genes, possibly from different donor species.

HLA-A*0201 restricted CD8+ T-lymphocyte responses to malaria: identification of new Plasmodium falciparum epitopes by IFN-gamma ELISPOT

The role of antigen specific CD8+ T-lymphocytes in mediating protection against sporozoite-induced malaria has been well established in murine models. In humans, indirect evidence has accumulated suggesting a similar protective role for antigen-specific CD8+ T-lymphocytes. Nevertheless, the low frequency of circulating specific cells together with the lack of sensitive methods to quantify them has hampered the direct assessment of their function. Using a combination of short-term cell culture and IFN-gamma ELISPOT, we studied CD8+ T-lymphocyte responses to a panel of HLA-A*0201 binding peptides. In addition to confirming the response to already described epitopes, we also identified five new CD8+ T-lymphocyte epitopes. These epitopes are presented in pre-erythrocytic stages gene products of Plasmodium falciparum 7G8 strain and correspond to the following protein segments: circumsporozoite (CS) 64-72, 104-113, 299-308 and 403-411; liver stage antigen (LSA-1) repeat region; sporozoite surface protein 2 or thrombospondin related anonymous protein (SSP2/TRAP) 78-88 and 504-513. Four of these peptides are conserved amongst all published sequences of P. falciparum strains. We conclude that the modified IFN-gamma ELISPOT assay is a sensitive technique to monitor antigen-specific CD8+ T-lymphocyte responses in human malaria which may help in the improvement and assessment of the efficacy of malaria subunit vaccines.

Bacterial community structure associated with a dimethylsulfoniopropionate-producing North Atlantic algal bloom

The bacteria associated with oceanic algal blooms are acknowledged to play important roles in carbon, nitrogen, and sulfur cycling, yet little information is available on their identities or phylogenetic affiliations. Three culture-independent methods were used to characterize bacteria from a dimethylsulfoniopropionate (DMSP)-producing algal bloom in the North Atlantic. Group-specific 16S rRNA-targeted oligonucleotides, 16S ribosomal DNA (rDNA) clone libraries, and terminal restriction fragment length polymorphism analysis all indicated that the marine Roseobacter lineage was numerically important in the heterotrophic bacterial community, averaging >20% of the 16S rDNA sampled. Two other groups of heterotrophic bacteria, the SAR86 and SAR11 clades, were also shown by the three 16S rRNA-based methods to be abundant in the bloom community. In surface waters, the Roseobacter, SAR86, and SAR11 lineages together accounted for over 50% of the bacterial rDNA and showed little spatial variability in abundance despite variations in the dominant algal species. Depth profiles indicated that Roseobacter phylotype abundance decreased with depth and was positively correlated with chlorophyll a, DMSP, and total organic sulfur (dimethyl sulfide plus DMSP plus dimethyl sulfoxide) concentrations. Based on these data and previous physiological studies of cultured Roseobacter strains, we hypothesize that this lineage plays a role in cycling organic sulfur compounds produced within the bloom. Three other abundant bacterial phylotypes (representing a cyanobacterium and two members of the alpha Proteobacteria) were primarily associated with chlorophyll-rich surface waters of the bloom (0 to 50 m), while two others (representing Cytophagales and delta Proteobacteria) were primarily found in deeper waters (200 to 500 m).

Evaluation of the AxSYM monoclonal cyclosporin assay and comparison with radioimmunoassay

Recently, a semiautomated fluorescence polarization immunoassay (FPIA) for determination of parent cyclosporin (CsA) has been developed for the Abbott AxSYM system. The new CsA assay measures the drug from an extracted whole blood specimen. The authors report here the evaluation of this new assay and the comparison with a previously validated radioimmunoassay (RIA) method (CYCLO-Trac SP). To assess the imprecision, the authors used tri-level controls supplied by both Abbott and Bio-Rad manufacturers. The within-run CV ranged from 4.4% to 7.3% and the between-day CV ranged from 4.4% to 7.6%. Mean recovery of the drug from clinical specimens spiked with kit calibrators was 108.4%. Fluorescence polarization immunoassay AxSYM (y) was correlated to RIA (x) by using 132 trough blood specimens (44 renal, 44 liver, and 44 heart) from transplant recipients and resulted in the following Passing-Bablok linear regression equation: y = 6.7 + 0.97x, r = 0.989, S(x/y) = 12.9. The percentage of overestimation (mean, range) by FPIA AxSYM versus RIA was (3.8%, range -17.7% to 39.1%). The results observed with this new method from follow-up studies in patients during the early course after transplant were not consistently higher than those obtained by RIA. These findings contrast with previously reported results that compared FPIA TDx assay with RIA. The authors conclude that FPIA AxSYM is a precise method for measuring CsA and offers results similar to those obtained by RIA with a marked reduction in assay time.