Finerenone protects against progression of kidney and cardiovascular damage in a model of type 1 diabetes through modulation of proinflammatory and osteogenic factors.

The non-steroidal mineralocorticoid receptor antagonist (MRA) finerenone (FIN) improves kidney and cardiovascular outcomes in patients with chronic kidney disease (CKD) in type 2 diabetes (T2D). We explored the effect of FIN in a novel model of type 1 diabetic Munich Wistar Frömter (MWF) rat (D) induced by injection of streptozotocin (15 mg/kg) and additional exposure to a high-fat/high-sucrose diet. Oral treatment with FIN (10 mg/kg/day in rat chow) in diabetic animals (D-FIN) was compared to a group of D rats receiving no treatment and a group of non-diabetic untreated MWF rats (C) (n = 7-10 animals per group). After 6 weeks, D and D-FIN exhibited significantly elevated blood glucose levels (271.7 ± 67.1 mg/dl and 266.3 ± 46.8 mg/dl) as compared to C (110.3 ± 4.4 mg/dl; p < 0.05). D showed a 10-fold increase of kidney damage markers Kim-1 and Ngal which was significantly suppressed in D-FIN. Blood pressure, pulse wave velocity (PWV) and arterial collagen deposition were lower in D-FIN, associated to an improvement in endothelial function due to a reduction in pro-contractile prostaglandins, as well as reactive oxygen species (ROS) and inflammatory cytokines (IL-1, IL-6, TNFα and TGFß) in perivascular and perirenal adipose tissue (PVAT and PRAT, respectively). In addition, FIN restored the imbalance observed in CKD between the procalcifying BMP-2 and the nephroprotective BMP-7 in plasma, kidney, PVAT, and PRAT. Our data show that treatment with FIN improves kidney and vascular damage in a new rat model of DKD with T1D associated with a reduction in inflammation, fibrosis and osteogenic factors independently from changes in glucose homeostasis.

Bioactive injectable hydrogels for on demand molecule/cell delivery and for tissue regeneration in the central nervous system.

Currently there are no potential curative therapies that can improve the central nervous system (CNS) regeneration after traumatic injuries or diseases. Indeed, the regeneration of CNS is greatly impaired by limited drug penetration across the blood brain barrier (BBB), poor drug targeting, deficient progenitor neural cells and limited proliferation of mature neural cells. To overcome these limitations, bioengineered injectable hydrogels in combination with drug and cell therapy have been proposed to mimic the complexity of the CNS microenvironment and architecture. Additionally, to enhance relevant CNS regeneration, proper biophysical and biochemical cues are needed. Recently, great efforts have been devoted to tailor stimuli-responsive hydrogels as novel carrier systems which are able to guide neural tissue regeneration. This review provides an extensive overview on the most promising injectable hydrogels for neural tissue engineering. A special emphasis is made to highlight the ability of these hydrogels to deliver bioactive compounds/cells upon the exposure to internal and external stimuli. Bioactive injectable hydrogels have a broad application in central nervous system's (CNS) regeneration. This review gives an overview of the latest pioneering approaches in CNS recovery using stimuli-responsive hydrogels for several neurodegenerative disorders. STATEMENT OF SIGNIFICANCE: This review summarizes the latest innovations on bioactive injectable hydrogels, focusing on tailoring internal/external stimuli-responsive hydrogels for the new injectable systems design, able to guide neural tissue response. The purpose is to highlight the advantages and the limitations of thermo-responsive, photo responsive, magnetic responsive, electric responsive, ultrasound responsive and enzymes-triggered injectable hydrogels in developing customizable neurotherapies. We believe that this comprehensive review will help in identifying the strengths and gaps in the existing literature and to further support the use of injectable hydrogels in stimulating CNS regeneration.

Caloric restriction induces H2O2 formation as a trigger of AMPK-eNOS-NO pathway in obese rats: Role for CAMKII.

Caloric restriction (CR) improves endothelial function through the upregulation of adenosine monophosphate-activated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS). Moreover, hydrogen peroxide (H2O2) is upregulated in yeast subjected to CR. Our aim was to assess if mild short-term CR increases vascular H2O2 formation as a link with AMPK and eNOS activation. Twelve-week old Zucker obese (fa/fa) and control Zucker lean male rats were fed a standard chow either ad libitum (AL, n=10) or with a 20% CR (CR, n=10) for two weeks. CR significantly improved relaxation to ACh in fa/fa rats because of an enhanced endogenous production of H2O2 in aortic rings (H2O2 levels fa/faAL=0.5 ±â€¯0.05 nmol/mg vs. H2O2 levels fa/faCR=0.76 ±â€¯0.07 nmol/mg protein; p<0.05). Expression of mitochondrial superoxide dismutase (Mn-SOD) and total SOD activity were increased in aorta from fa/fa animals after CR. In cultured aortic endothelial cells, serum deprivation or 2-deoxy-d-glucose induced a significant increase in: i) superoxide anion and H2O2 levels, ii) p-AMPK/AMPK and p-eNOS/eNOS expression and iii) nitric oxide levels. This effect was reduced by catalase and strongly inhibited by Ca2+/calmodulin-dependent kinase II (CamkII) silencing. In conclusion, we propose that mild short-term CR might be a trigger of mechanisms aimed at protecting the vascular wall by the increase of H2O2, which then activates AMPK and nitric oxide release, thus improving endothelium-dependent relaxation. In addition, we demonstrate that CAMKII plays a key role in mediating CR-induced AMPK activation through H2O2 increase.

Using Clinical Signs and Symptoms for Medical Management of Radiation Casualties - 2015 NATO Exercise.

The utility of early-phase (≤5 days) radiation-induced clinical signs and symptoms (e.g., vomiting, diarrhea, erythema and changes in blood cell counts) was examined for the prediction of later occurring acute radiation syndrome (ARS) severity and the development of medical management strategies. Medical treatment protocols for radiation accident victims (METREPOL) was used to grade ARS severities, which were assigned response categories (RCs). Data on individuals (n = 191) with mild (RC1, n = 45), moderate (RC2, n = 19), severe (RC3, n = 20) and fatal (RC4, n = 18) ARS, as well as nonexposed individuals (RC0, n = 89) were generated using either METREPOL (n = 167) or the system for evaluation and archiving of radiation accidents based on case histories (SEARCH) database (n = 24), the latter comprised of real-case descriptions. These data were converted into tables reflecting clinical signs and symptoms, and submitted to eight teams representing five participating countries. The teams were comprised of medical doctors, biologists and pharmacists with subject matter expertise. The tables comprised cumulated clinical data from day 1-3 and day 1-5 postirradiation. While it would have reflected a more realistic scenario to provide the data to the teams over the course of a 3- or 5-day period, the logistics of doing so proved too challenging. In addition, the team members participating in this exercise chose to receive the cumulated reports of day 1-3 and 1-5. The teams were tasked with predicting ARS incidence, ARS severity and the requirement for hospitalization for multiple cases, as well as providing the certainty of their diagnosis. Five of the teams also performed dose estimates. The teams did not employ harmonized methodologies, and the expertise among the members varied, as did the tools used and the means of analyzing the clinical data. The earliest report time was 3 h after the tables were sent to the team members. The majority of cases developing ARS (89.6% ± 3.3 SD) and requiring hospitalization (88.8% ± 4.6 SD) were correctly identified by all teams. Determination of ARS severity was particularly challenging for RC2-3, which was systematically overestimated. However, RC4 was correctly predicted at 94-100% by all teams. RC0 and RC1 ARS severities were more difficult to discriminate. When reported RCs (0-1 and 3-4) were merged, on average 89.6% (±3.3 SD) of all cases could be correctly classified. Comparisons on frequency distributions revealed no statistically significant differences among the following: 1. reported ARS from different teams (P > 0.2); 2. cases generated based on METREPOL or SEARCH (P > 0.5); or 3. results reported at day 3 and 5 postirradiation (P > 0.1). Dose estimates of all teams increased significantly along with ARS severity (P < 0.0001) as well as with dose estimates generated from dicentric chromosomal-aberration measurements available for SEARCH cases (P < 0.0001). In summary, early-phase radiation-induced clinical signs and symptoms proved to be useful for rapid and accurate assessment, with minor limitations, toward predicting life-threatening ARS severity and developing treatment management strategies.

Genome-based study of a spatio-temporal cluster of invasive meningococcal disease due to Neisseria meningitidis serogroup C, clonal complex 11.

OBJECTIVES: To describe a spatio-temporal cluster of invasive meningococcal disease (IMD) due to serogroup C meningococci, occurred in a restricted area of Tuscany between January and October 2015, and the results of whole genome sequencing (WGS). METHODS: Surveillance activities and public health measures were implemented in the Region. Bacterial isolates from IMD cases were characterized by the National Reference Laboratory of the Istituto Superiore di Sanità (ISS), and WGS was performed on available strains. The kSNP software was used to identify core genome SNPs. RESULTS: Overall, 28 IMD cases due to meningococcus C were identified up to 31st October, 2015. Of them, 26 were due to meningococcus C:P1.5-1,10-8: F3-6:ST-11 (cc11) and 2 to C:P1.5-1,10-8: F3-6:ST-2780 (cc11). WGS of 13 meningococci isolated during the outbreak occurred in Tuscany in 2015 showed higher similarity when compared with those of 47 C: P1.5-1,10-8: F3-6:ST-11 (cc11) invasive strains from sporadic cases previously detected in Italy. CONCLUSIONS: A highly aggressive meningococcal C strain was involved in the cluster of severe IMD occurred in Tuscany, a Region with high vaccine coverage among children. Whether this was due to low herd immunity related to the short duration of vaccine protection needs further investigation.

Draft Genome Sequence of a Bordetella pertussis Strain with the Virulence-Associated Allelic Variant ptxP3, Isolated in Italy.

Despite a universal immunization program, pertussis has persisted and resurged, and is of particular concern for infants in terms of morbidity and mortality. Here, we report the genome sequence of a Bordetella pertussis strain with the virulence-associated allelic variant ptxP3, isolated from a 45-day-old infant.

Draft Genome Sequence of Neisseria gonorrhoeae Sequence Type 1407, a Multidrug-Resistant Clinical Isolate.

Gonorrhea may become untreatable due to the spread of resistant or multidrug-resistant strains. Cefixime-resistant gonococci belonging to sequence type 1407 have been described worldwide. We report the genome sequence of Neisseria gonorrhoeae strain G2891, a multidrug-resistant isolate of sequence type 1407, collected in Italy in 2013.

Whole-Genome Sequencing of Mycoplasma mycoides subsp. mycoides Italian Strain 57/13, the Causative Agent of Contagious Bovine Pleuropneumonia.

Mycoplasma mycoides subsp. mycoides is generally considered one of most pathogenic Mycoplasma species, and it is the etiological agent of contagious bovine pleuropneumonia (CBPP). Here, we present the annotated genome sequence of M. mycoides subsp. mycoides Italian strain 57/13, isolated in 1992 during CBPP outbreaks in Italy.

Multiparametric magnetic resonance imaging predicts the presence of prostate cancer in patients with negative prostate biopsy.

OBJECTIVE: To assess the ability of multiparametric prostate magnetic resonance imaging (mpMRI) to detect prostate cancer in patients with prior negative transrectal prostate biopsy (TPB). MATERIAL AND METHODS: mpMRI (TSE-T2-w, DWI and DCE sequences) was performed on 1.5T (Magnetom Avanto; Siemens Healthcare Solutions) in 150 patients suspicious of prostate cancer and with negative TPB. European Society of Urogenital Radiology (ESUR) criteria were used (score 1: clinically significant disease is highly unlikely to be present; score 2: clinically significant cancer is unlikely to be present; score 3: clinically significant cancer is equivocal; score 4: clinically significant cancer is likely to be present; score 5: clinically significant cancer is highly likely to be present). PSA measurement (total and free), digital rectal examination (DRE), transrectal ultrasound (TRU) and a second TPB (at least 14 cylinders) were performed in all patients. Variables were submitted for independent blind analysis. The accuracy of each test was measured. Stepwise selection model for prediction of prostate cancer in second TPB was developed. RESULTS: Mean age was 66.2± 5 years (51-77), mean PSA 11.3± 9.6ng/mL (0.9-75) and mean prostatic volume 82.2±42 (20-250) cc. DRE was suspicious in 11 (7.3%) patients. The mean number of cylinders per patient sampled in second TRB was 17.6±2.7(14-22). Second TRB was positive in 28 patients (18.7%). mpMRI was positive (score 3-5) in 102 (68%), test sensibility was 92.9% and the NPV was 95.8%. The risk of prostate cancer diagnosis in second TPB is modified by: PSA velocity > 0.75 (OR 1.04 [0.99-1.08]; P=0.06), free/total ratio PSA <15% (OR 0.37 [0.13-1.05]; P=0.06), each cc. of prostate volume (OR 0.98 [0.97-1]; P=0.017) and mpMRI 3-5 (OR 7.87 [1.78-34.7]; P=0.006). Multivariate analysis reveals that mpMRI (OR 7.41 [1.65-33.28]; P=0.009) and prostatic volume (OR 0.31 [0.12-0.78]; P=0.01) are independent risk predictors of prostate cancer. CONCLUSIONS: According to ESUR guidelines and in patients with prior negative prostate biopsy, mpMRI is a valuable tool for the prediction of prostate cancer in second TPB. Lower prostate volume, the higher reliability.

Draft Genome Sequence of C:P1.5-1,10-8:F3-6:ST-11 Meningococcal Clinical Isolate Associated with a Cluster on a Cruise Ship.

Meningococcal serogroup C strains, in particular those belonging to the ST-11 clonal complex, are known to cause invasive diseases worldwide. We report the genome sequence of a Neisseria meningitidis strain linked to a cluster of cases of invasive meningococcal disease on a cruise ship that was described in 2012.

Virtual reality simulator for training on photoselective vaporization of the prostate with 980 nm diode laser and learning curve of the technique.

OBJECTIVE: The utility of a virtual reality simulator for training of the photoselective vaporization of the prostate with diode laser was studied. MATERIAL AND METHOD: Two experiments were performed with a simulator (VirtaMed AG, Zürich, Switzerland) with software for specific training in prostate vaporization in contact mode with Twister fiber (Biolitec AG, Jena, German). Eighteen surgeons performed ablation of the prostate (55 cc) twice and compared the score obtained (190 points efficacy and 80 safety) in the second one of them by experience groups (medical students, residents, specialists). They also performed a spatial orientation test with scores of 0 to 6. After, six of these surgeons repeated 15 ablations of the prostate (55 and 70 ml). Improvement of the parameters obtained was evaluated to define the learning curve and how experience, spatial orientation skills and type of sequences performed affects them. RESULTS: Global efficacy and safety score was different according to the grade of experience (P=.005). When compared by pairs, specialist-student differences were detected (p=0.004), but not specialist-resident (P=.12) or resident-student (P=.2). Regarding efficacy of the procedure, specialist-student (p=0.0026) and resident-student (P=.08) differences were detected. The different partial indicators in terms of efficacy were rate of ablation (P=.01), procedure time (P=.03) and amount of unexposed capsule (p=0.03). Differences were not observed between groups in safety (P=.5). Regarding the learning curve, percentage median on the total score exceeded 90% after performing 4 procedures for prostates of 55 ml and 10 procedures for prostate glands of 70 ml. This course was not modified by previous experience (resident-specialist; P=.6). However, it was modified according to the repetition sequence (progressive-random; P=.007). Surgeons whose spatial orientation was less than the median of the group (value 2.5) did not surpass 90% of the score in spite of repetition of the procedure. CONCLUSION: Simulation for ablation of the prostate with contact diode laser is a good learning model with discriminative validity, as it correlates the metric results with levels of experience and sills. The sequential repetition of the procedure on growing levels of difficulty favors learning.

Efficacy and safety of fosfomycin-trometamol in the prophylaxis for transrectal prostate biopsy. Prospective randomized comparison with ciprofloxacin.

OBJECTIVE: Prostate biopsy is the standardized diagnostic method for prostate cancer. However, although there is not a standardized protocol, there are recommendations in order to reduce the incidence of complications. The objective of the present work is to assess the efficacy and safety of antibiotic prophylaxis in the prostate biopsy by comparing two antibiotic regimes: two doses of fosfomycin-trometamol 3g (FMT) every 48 hours with 10 doses of oral ciprofloxacin 500 mg every 12 hours during 5 days. MATERIAL AND METHODS: Randomized prospective study was performed with 671 patients who had undergone to walking transrectal ultrasound guided prostate biopsy. Patients of group A (n=312) were treated with ciprofloxacin, and patients of group B (n=359) with FMT. Efficacy and tolerability of two prophylactic regimes were compared. Urine culture was carried out at 2 weeks after biopsy. Initially, patients with asymptomatic bacteriuria were not treated with antibiotics; urine culture was repeated after 1 month, persistent bacteriuria was treated according to antibiogram. RESULTS: No differences between groups were found in age (P=.78), cancer presence (P=.9) or number of biopsy cylinders (P=.93). The mean number of cores obtained was 11.3 ± 3.25 (range 6-20). Digestive intolerance was observed for 9 patients (2.9%) of group A and 10 patients (2.8%) in group B. One patient (.3%) of group A showed severe allergic reaction. In total, 167 patients (24.6%) had complications: 16 (2.4%) fever, 47 (6.9%) hemospermia, 81 (11.9%) hematuria, 7 (1%) rectal bleeding and 16 (2.4%) urinary retention. No statistically differences between groups were observed (27.6% vs. 22.6%; P=.17). However, hemospermia was more frequent in group A (9.9% vs. 4.5%; P=.006). Bacteriuria after biopsy was detected in 44 patients (6.6%), being more frequent in group B patients (4.2% vs. 8.6%; P=.02) although a higher number of second treatment cycles were not needed (53.9% vs. 29%; P=.17). The likelihood of resistance to ciprofloxacin in patients with bacteriuria in A was greater than that of FMT in B (69.2% vs. 41.9%; P=.0004). CONCLUSIONS: Antibiotic prophylaxis with FMT (2 doses of 3g) in prostate biopsy is an alternative as effective and safe as ciprofloxacin (10 doses of 500 mg), which carries lower rate of resistance. According to our experience, this drug is a safe, well-tolerated, and easily manageable prophylactic option, facilitating patient compliance. More prospective multicenter studies are necessary to confirm these findings.

Cytokinesis-block micronucleus assay by manual and automated scoring: calibration curves and dose prediction.

The cytokinesis-block micronucleus assay in peripheral blood lymphocytes is one of the best standardized and validated techniques for individual radiation dose assessment. This method has been proposed as an alternative to the dicentric chromosome assay, which is considered the "gold standard" in biological dosimetry because it requires less time and cytogenetic expertise. Nevertheless, for application as a biodosimetry tool in large-scale nuclear or radiological accidents, the manually performed cytokinesis-block micronucleus assay needs further strategies (e.g., the automation of micronucleus scoring) to speed up the analysis. An essential prerequisite for radiation dose assessment is to establish a dose-effect curve. In this study, blood samples of one healthy subject were irradiated with seven increasing doses of x-ray (240 kVp, 1 Gy min⁻¹) ranging from 0.25-4.0 Gy to generate calibration curves based on manual as well as on automated scoring mode. The quality of the calibration curves was evaluated by determination of the dose prediction accuracy after the analysis of 10 blood samples from the same donor exposed to unknown radiation doses. The micronucleus frequencies in binucleated cells were scored manually as well as automatically and were used to assess the absorbed radiation doses with reference to the respective calibration curve. The accuracy of the dose assessment based on manual and automatic scoring mode was compared.

Multiparametric magnetic resonance imaging for the assessment of extracapsular invasion and other staging parameters in patients with prostate cancer candidates for radical prostatectomy.

INTRODUCTION: the proper evaluation of the extracapsular extension (ECE), the invasion of seminal vesicles and regional lymph nodes are necessary to plan the treatment of localized prostate cancer. A model that assesses the risk of ECE in the specimen considering the clinical, histological and imaging findings is defined. MATERIAL AND METHODS: prospective study in 85 patients with prostate cancer treated with radical prostatectomy. Prostate biopsy was performed 4 weeks before multiparametric study (mpMRI). mpMRI included T2-weighted endorectal magnetic resonance imaging (T2W-MRI), diffusion-weighted magnetic resonance imaging (DW-MRI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). The apparent diffusion coefficient (ADC) was also measured. A study of consistency (k) was assessed comparing receiver operating characteristic (ROC) curve and area under the curve (AUC), which were obtained in each case (Z). Finally, a regression model was performed to predict ECE. RESULTS: the mean age was 63.7 ± 6.9 years and the mean value of PSA 12.6 ± 13.8. In 31.7% of cases, digital rectal examination was suspicious for malignancy. Prostatectomy specimen showed pT2a in 12 cases (14%), pT2b in 3 (3%), pT2c in 37 (43%), pT3a in 19(22%) and pT3b 14 cases (17%). ECE was evidenced in 33 (39%) of the specimens, seminal vesicle invasion in 14 (16.5%) and pelvic node involvement in 5 patients (6%). The consistency in the evaluation of ECE (image and pathological studies) was .35 for MRI (sensitivity .33, specificity .96) and .62 for mpMRI (sensitivity .58, specificity .98). Mean value of ADC was .76 ± .2 in patients with ECE. This value was not associated with Gleason score (P = .2) or with PSA value (P = .6). AUC value as predictor of ECE was of 65% for MRI, 78% for mpMRI and 50% ADC (Z = .008). Univariate analysis demonstrated that ECE probability increases with each Gleason score point, whilst this probability increases 1.06 times with each PSA point, and decreases .3 times with each point of ADC. Multivariate analysis confirmed that ADC value is a slight protective factor against ECE (OR = .01; CI 95% .002-.14). The consistency in the evaluation of seminal vesicles was .43 for MRI and .67 for mpMRI. AUC was 69% and 82% respectively (Z = .02). The consistency in the evaluation of positive lymph nodes was .4 for MRI and .7 for mpMRI. AUC was 68% and 88% respectively (Z = .36). CONCLUSIONS: multiparametric study allows to carry out a more proper preoperative evaluation of ECE than convectional MRI. The most reliable predictors of ECE are DW-MRI combined with DCE-MRI, ADC coefficient and Gleason score. The superiority of mpMRI is also demonstrated for detection of seminal vesicles invasion, but not for the evaluation of lymph nodes invasion.

Prediction of extracapsular disease with multiparametric magnetic resonance imaging in high risk localized prostate cancer patient.

OBJECTIVES: To assess the usefulness of multiparametric magnetic resonance imaging (MRI) in the staging of patients with localized prostate cancer (PC) and high risk of extracapsular disease (ECD). METHODS: Retrospective study including 30 patients with localized PC and high risk of ECD. Pathologist and radiologist established an ECD suspicion according to the evaluation of the prostatic biopsy specimens and the multiparametric MRI analysis, respectively. Radical prostatectomy (RP) specimen analysis was used as a definitive confirmatory reference. Kappa (k)test was used to assess the degree of consistency between the initial suspicion provided by both specialists and the reference RP specimen. RESULTS: When the prostatic gland was analyzed as a single unit, the pathological evaluation of the biopsy specimens did not correctly detect the risk of ECD in 46.6% of the patients (14/30; 10 FN; k=-0.035, 95%CI [-0.29-0.36]), while multiparametric MRI did not do in 36% of the cases (11/30, 9 FP; k=0.27, 95%CI [-0.03-0.61]). Whereas, if each side of the prostate (i.e. right and left) was considered as an independent observation, the pathologist wrongly predicted the risk of ECD in 35% of the cases (21/60; 18 FN; k=0.19, 95%CI [-0.03-0.40]), while the radiologist erred only in 18.3% of the cases (11/60; 7 FN and 4 FP; k=0, 61, 95%CI [0.40-0.81]). CONCLUSIONS: Data from our experience suggest an added value of multiparametric MRI in the clinical staging of localized PC in cases of high risk of ECD. Multiparametric MRI may be used as a helpful tool in the surgical planning and the decision-making process regarding the management of this entity.

Comparison of established and emerging biodosimetry assays.

Rapid biodosimetry tools are required to assist with triage in the case of a large-scale radiation incident. Here, we aimed to determine the dose-assessment accuracy of the well-established dicentric chromosome assay (DCA) and cytokinesis-block micronucleus assay (CBMN) in comparison to the emerging γ-H2AX foci and gene expression assays for triage mode biodosimetry and radiation injury assessment. Coded blood samples exposed to 10 X-ray doses (240 kVp, 1 Gy/min) of up to 6.4 Gy were sent to participants for dose estimation. Report times were documented for each laboratory and assay. The mean absolute difference (MAD) of estimated doses relative to the true doses was calculated. We also merged doses into binary dose categories of clinical relevance and examined accuracy, sensitivity and specificity of the assays. Dose estimates were reported by the first laboratories within 0.3-0.4 days of receipt of samples for the γ-H2AX and gene expression assays compared to 2.4 and 4 days for the DCA and CBMN assays, respectively. Irrespective of the assay we found a 2.5-4-fold variation of interlaboratory accuracy per assay and lowest MAD values for the DCA assay (0.16 Gy) followed by CBMN (0.34 Gy), gene expression (0.34 Gy) and γ-H2AX (0.45 Gy) foci assay. Binary categories of dose estimates could be discriminated with equal efficiency for all assays, but at doses ≥1.5 Gy a 10% decrease in efficiency was observed for the foci assay, which was still comparable to the CBMN assay. In conclusion, the DCA has been confirmed as the gold standard biodosimetry method, but in situations where speed and throughput are more important than ultimate accuracy, the emerging rapid molecular assays have the potential to become useful triage tools.

Laboratory intercomparison of the dicentric chromosome analysis assay.

The study design and obtained results represent an intercomparison of various laboratories performing dose assessment using the dicentric chromosome analysis (DCA) as a diagnostic triage tool for individual radiation dose assessment. Homogenously X-irradiated (240 kVp, 1 Gy/min) blood samples for establishing calibration data (0.25-5 Gy) as well as blind samples (0.1-6.4 Gy) were sent to the participants. DCA was performed according to established protocols. The time taken to report dose estimates was documented for each laboratory. Additional information concerning laboratory organization/characteristics as well as assay performance was collected. The mean absolute difference (MAD) was calculated and radiation doses were merged into four triage categories reflecting clinical aspects to calculate accuracy, sensitivity and specificity. The earliest report time was 2.4 days after sample arrival. DCA dose estimates were reported with high and comparable accuracy, with MAD values ranging between 0.16-0.5 Gy for both manual and automated scoring. No significant differences were found for dose estimates based either on 20, 30, 40 or 50 cells, suggesting that the scored number of cells can be reduced from 50 to 20 without loss of precision of triage dose estimates, at least for homogenous exposure scenarios. Triage categories of clinical significance could be discriminated efficiently using both scoring procedures.

Laboratory intercomparison of the cytokinesis-block micronucleus assay.

The focus of the study is an intercomparison of laboratories' dose-assessment performances using the cytokinesis-block micronucleus (CBMN) assay as a diagnostic triage tool for individual radiation dose assessment. Homogenously X-irradiated (240 kVp, 1 Gy/min) blood samples for establishing calibration data (0.25-5 Gy) as well as blind samples (0.1-6.4 Gy) were sent to the participants. The CBMN assay was performed according to protocols individually established and varying among participating laboratories. The time taken to report dose estimates was documented for each laboratory. Additional information concerning laboratory organization/characteristics as well as assay performance was collected. The mean absolute difference (MAD) was calculated and radiation doses were merged into four triage categories reflecting clinical aspects to calculate accuracy, sensitivity and specificity. The earliest report time was 4 days after sample arrival. The CBMN dose estimates were reported with high accuracy (MAD values of 0.20-0.50 Gy at doses below 6.4 Gy for both manual and automated scoring procedures), but showed a limitation of the assay at the dose point of 6.4 Gy, which resulted in a clear dose underestimation in all cases. The MAD values (without 6.4 Gy) differed significantly (P = 0.03) between manual (0.25 Gy, SEM = 0.06, n = 4) or automated scoring procedures (0.37 Gy, SEM = 0.08, n = 5), but lowest MAD were equal (0.2 Gy) for both scoring procedures. Likewise, both scoring procedures led to the same allocation of dose estimates to triage categories of clinical significance (about 83% accuracy and up to 100% specificity).

Laboratory intercomparison on the γ-H2AX foci assay.

The focus of the study is an intercomparison of laboratories' dose-assessment performances using the γ-H2AX foci assay as a diagnostic triage tool for rapid individual radiation dose assessment. Homogenously X-irradiated (240 kVp, 1 Gy/min) blood samples for establishing calibration data (0.25-4 Gy) as well as blinded test samples (0.1-6.4 Gy) were incubated at 37°C for 2 and 24 h (repair time) and sent to the participants. The foci assay was performed according to protocols individually established in participating laboratories and therefore varied. The time taken to report dose estimates was documented for each laboratory. Additional information concerning laboratory organization/characteristics as well as assay performance was collected. The mean absolute difference (MAD) of estimated doses relative to the actual doses was calculated and radiation doses were merged into four triage categories reflecting clinical relevance to calculate accuracy, sensitivity and specificity. First γ-H2AX based dose estimates were reported 7 h after sample receipt. Estimates were similarly accurate for 2 and 24 h repair times, providing scope for its use in the early phase of a radiation exposure incident. Equal accuracy was achieved by scoring 20, 30, 40 or 50 cells per sample. However, MAD values of 0.5-0.7 Gy and 1.3-1.7 Gy divided the data sets into two groups, driven mainly by the considerable differences in foci yields between calibration and blind samples. Foci yields also varied dramatically between laboratories, highlighting reproducibility issues as an important caveat of the foci assay. Nonetheless, foci counts could distinguish high- and low-dose samples in all data sets and binary dose categories of clinical significance could be discriminated with satisfactory accuracy (mean 84%, ±0.03 SEM). Overall, the results suggest that the γ-H2AX assay is a useful tool for rapidly screening individuals for significant exposures that occurred up to at least 24 h earlier, and may help to prioritize cytogenetic dosimetry follow-up.

Laboratory intercomparison of gene expression assays.

The possibility of a large-scale acute radiation exposure necessitates the development of new methods that could provide rapid individual dose estimates with high sample throughput. The focus of the study was an intercomparison of laboratories' dose-assessment performances using gene expression assays. Lithium-heparinized whole blood from one healthy donor was irradiated (240 kVp, 1 Gy/min) immediately after venipuncture at approximately 37°C using single X-ray doses. Blood samples to establish calibration curves (0.25-4 Gy) as well as 10 blinded test samples (0.1-6.4 Gy) were incubated for 24 h at 37°C supplemented with an equal volume of medium and 10% fetal calf serum. For quantitative reverse transcription polymerase chain reaction (qRT-PCR), samples were lysed, stored at -20°C and shipped on ice. For the Chemical Ligation Dependent Probe Amplification methodology (CLPA), aliquots were incubated in 2 ml CLPA reaction buffer (DxTerity), mixed and shipped at room temperature. Assays were run in each laboratory according to locally established protocols. The mean absolute difference (MAD) of estimated doses relative to the true doses (in Gy) was calculated. We also merged doses into binary categories reflecting aspects of clinical/diagnostic relevance and examined accuracy, sensitivity and specificity. The earliest reported time on dose estimates was <8 h. The standard deviation of technical replicate measurements in 75% of all measurements was below 11%. MAD values of 0.3-0.5 Gy and 0.8-1.3 Gy divided the laboratories contributions into two groups. These fourfold differences in accuracy could be primarily explained by unexpected variances of the housekeeping gene (P = 0.0008) and performance differences in processing of calibration and blinded test samples by half of the contributing laboratories. Reported gene expression dose estimates aggregated into binary categories in general showed an accuracies and sensitivities of 93-100% and 76-100% for the groups, with low MAD and high MAD, respectively. In conclusion, gene expression-based dose estimates were reported quickly, and for laboratories with MAD between 0.3-0.5 Gy binary dose categories of clinical significance could be discriminated with an accuracy and sensitivity comparable to established cytogenetic assays.