High-mobility group box-1 protein determination in postmortem samples.

The aims of this study were to assess whether high-mobility group box-1 protein can be determined in biological fluids collected during autopsy and evaluate the diagnostic potential of high-mobility group box-1 protein in identifying sepsis-related deaths. High-mobility group box-1 protein was measured in serum collected during hospitalization as well as in undiluted and diluted postmortem serum and pericardial fluid collected during autopsy in a group of sepsis-related deaths and control cases with noninfectious causes of death. Inclusion criteria consisted of full biological sample availability and postmortem interval not exceeding 6h. The preliminary results indicate that high-mobility group box-1 protein levels markedly increase after death. Concentrations beyond the upper limit of the calibration curve were obtained in undiluted postmortem serum in septic and traumatic control cases. In pericardial fluid, concentrations beyond the upper limit of the calibration curve were found in all cases. These findings suggest that the diagnostic potential of high-mobility group box-1 protein in the postmortem setting is extremely limited due to molecule release into the bloodstream after death, rendering antemortem levels difficult or impossible to estimate even after sample dilution.

Dermatophyte identification in skin and hair samples using a simple and reliable nested polymerase chain reaction assay.

BACKGROUND: Dermatophyte identification in tinea capitis is essential for choosing the appropriate treatment and in tinea infections to identify the possible source. The failure of fungi to grow in cultures frequently occurs, especially in cases of previous antifungal therapy. OBJECTIVES: To develop a rapid polymerase chain reaction (PCR) sequencing assay for dermatophyte identification in tinea capitis and tinea corporis. MATERIAL AND METHODS: Fungal DNA was extracted from hair and skin samples that were confirmed to be positive by direct mycological examination. Dermatophytes were identified by the sequence of a 28S ribosomal DNA subunit amplicon generated by nested PCR. RESULTS: Nested PCR was found to be necessary to obtain amplicons in substantial amounts for dermatophyte identification by sequencing. The results agreed with those of classical mycological identification in 14 of 23, 6 of 10, and 20 of 23 cases of tinea capitis, tinea corporis and tinea pedis, respectively, from which a dermatophyte was obtained in culture. In seven of the 56 cases, another dermatophyte was identified, revealing previous misidentification. A dermatophyte was identified in 12 of 18, three of five, and four of nine cases of tinea capitis, tinea corporis and tinea pedis, respectively, in cases in which no dermatophyte grew in culture. CONCLUSIONS: Although the gold standard dermatophyte identification from clinical samples remains fungal cultures, the assay developed in the present study is especially suitable for tinea capitis. Improved sensitivity for the identification of dermatophyte species was obtained as it is possible to identify the dermatophyte when the fungus fails to grow in cultures.

Comparison of the NEO-FFI, the NEO-FFI-R and an alternative short version of the NEO-PI-R (NEO-60) in Swiss and Spanish samples

Three different short versions of the NEO-PI-R were compared: The NEO-FFI, the NEO-FFI-R, and a new short version developed in the current study (NEO-60). This new version is intended to improve the psychometric characteristics of the original NEO-FFI, specially in regard to the factor structure at the item-level. A French version of the NEO-PI-R was given to 1090 Swiss subjects, whereas the Spanish (Castilian) version of the NEO-PI-R was administered to 1006 Spanish subjects. Results replicate the limitations of the NEO-FFI already found in other countries. Compared to the NEO-FFI, reliability coefficients and factor structure was enhanced by the NEO-FFI-R and the NEO-60 in both samples, although substantial differences were not found. The factor structure of the NEO-60 shows the best fit since only three items do not load mainly on their own factor in both samples. Besides, correlations between items and NEO-PI-R domain scores are also higher for the items included in the NEO-60 version. On the other hand, convergent correlations with the NEO-PI-R dimensions were satisfactory irrespective of the version, and confirmatory factor analyses show slight differences among the different models generated after the three short versions.

The 16PF5 and the NEO-PI-R in Spanish and Swiss samples: A cross-cultural comparison

This study compared the Spanish (Castilian) and French versions of the 16PF5 and of the NEO-PI-R in Spanish and Swiss samples. The five-factor solution for the 16PF5 only seems clear for the Castilian version, but not for the French version. Indeed, the congruence coefficients for the Tough-Mindedness and the Self-Control dimensions are low. On the other hand, the five-factor solutions are highly similar for both countries concerning the NEO-PI-R, and the congruence coefficients are above .95 for all five dimensions. The low cross-cultural replicability for the 16PF5 makes it difficult to analyze the differences at the mean level for this inventory. For the NEO-PI-R, the differences are generally very small and globally account for 2.6% of the total variance. Spaniards seem to have slightly lower scores on Actions and slightly higher scores on Dutifulness. These differences could either be due to translation problems, sample selection, or cultural differences.

Field testing of arsenic in groundwater samples of Bangladesh using a test kit based on lyophilized bioreporter bacteria.

A test kit based on living, lyophilized bacterial bioreporters emitting bioluminescence as a response to arsenite and arsenate was applied during a field campaign in six villages across Bangladesh. Bioreporter field measurements of arsenic in groundwater from tube wells were in satisfying agreement with the results of spectroscopic analyses of the same samples conducted in the lab. The practicability of the bioreporter test in terms of logistics and material requirements, suitability for high sample throughput, and waste disposal was much better than that of two commercial chemical test kits that were included as references. The campaigns furthermore demonstrated large local heterogeneity of arsenic in groundwater, underscoring the use of well switching as an effective remedy to avoid high arsenic exposure.

New perspectives in the use of ink evidence in forensic science: Part II. Development and testing of mathematical algorithms for the automatic comparison of ink samples analysed by HPTLC

In the first part of this research, three stages were stated for a program to increase the information extracted from ink evidence and maximise its usefulness to the criminal and civil justice system. These stages are (a) develop a standard methodology for analysing ink samples by high-performance thin layer chromatography (HPTLC) in reproducible way, when ink samples are analysed at different time, locations and by different examiners; (b) compare automatically and objectively ink samples; and (c) define and evaluate theoretical framework for the use of ink evidence in forensic context. This report focuses on the second of the three stages. Using the calibration and acquisition process described in the previous report, mathematical algorithms are proposed to automatically and objectively compare ink samples. The performances of these algorithms are systematically studied for various chemical and forensic conditions using standard performance tests commonly used in biometrics studies. The results show that different algorithms are best suited for different tasks. Finally, this report demonstrates how modern analytical and computer technology can be used in the field of ink examination and how tools developed and successfully applied in other fields of forensic science can help maximising its impact within the field of questioned documents.

A genomewide association study of smoking relapse in four European population-based samples.

OBJECTIVES: Genomewide association studies (GWAS) have identified clear evidence of genetic markers for nicotine dependence. Other smoking phenotypes have been tested, but the results are less consistent. The tendency to relapse versus the ability to maintain long-term abstinence has received little attention in genetic studies; thus, our aim was to provide a better biological understanding of this phenotype through the identification of genetic loci associated with smoking relapse. METHODS: We carried out a GWAS on data from two European population-based collections, including a total of 835 cases (relapsers) and 990 controls (abstainers). Top-ranked findings from the discovery phase were tested for replication in two additional independent European population-based cohorts. RESULTS: Of the seven top markers from the discovery phase, none were consistently associated with smoking relapse across all samples and none reached genomewide significance. A single-nucleotide polymorphism rs1008509, within the Xylosyltransferase II (XYLT2) gene, was suggestively associated with smoking relapse in the discovery phase (β=-0.504; P=5.6E-06) and in the first replication sample (ALSPAC) (β=-0.27; P=0.004; n=1932), but not in the second sample (KORA) (β=0.19; P=0.138; n=912). We failed to identify an association between loci implicated previously in other smoking phenotypes and smoking relapse. CONCLUSION: Although no genomewide significant findings emerged from this study, we found that loci implicated in other smoking phenotypes were not associated with smoking relapse, which suggests that the neurobiology of smoking relapse and long-term abstinence may be distinct from biological mechanisms implicated in the development of nicotine dependence.

Confirmation of natural gas explosion from methane quantification by headspace gas chromatography-mass spectrometry (HS-GC-MS) in postmortem samples: a case report.

A new analytical approach for measuring methane in tissues is presented. For the first time, the use of in situ-produced, stably labelled CDH(3) provides a reliable and precise methane quantification. This method was applied to postmortem samples obtained from two victims to help determine the explosion origin. There was evidence of methane in the adipose tissue (82 nmol/g) and cardiac blood (1.3 nmol/g) of one victim, which corresponded to a lethal methane outburst. These results are discussed in the context of the available literature to define an analysis protocol for application in the event of a gas explosion.

Distribution of free and conjugated cannabinoids in human bile samples.

The metabolism of Δ(9)-tetrahydrocannabinol (THC) is relatively complex, and over 80 metabolites have been identified. However, much less is known about the formation and fate of cannabinoid conjugates. Bile excretion is known to be an important route for the elimination of phase II metabolites. A liquid chromatography-tandem mass spectrometry LC-MS/MS procedure for measuring cannabinoids in oral fluid was adapted, validated and applied to 10 bile samples. THC, 11-hydroxy-Δ(9)-tetrahydrocannabinol (11-OH-THC), 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THCCOOH), cannabinol (CBN), cannabidiol (CBD), Δ(9)-tetrahydrocannabinolic acid A (THC-A), 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol glucuronide (THCCOOH-gluc) and Δ(9)-tetrahydrocannabinol glucuronide (THC-gluc) were determined following solid-phase extraction and LC-MS/MS. High concentrations of THCCOOH-gluc were found in bile samples (range: 139-21,275 ng/mL). Relatively high levels of THCCOOH (7.7-1548 ng/mL) and THC-gluc (38-1366 ng/mL) were also measured. THC-A, the plant precursor of THC, was the only cannabinoid that was not detected. These results show that biliary excretion is an important route of elimination for cannabinoids conjugates and that their enterohepatic recirculation is a significant factor to consider when analyzing blood elimination profiles of cannabinoids. Furthermore, we suggest that the bile is the matrix of choice for the screening of phase II cannabinoid metabolites.

Endoscopic low-coherence topography measurement for upper airways and hollow samples.

To evaluate the severity of airway pathologies, quantitative dimensioning of airways is of utmost importance. Endoscopic vision gives a projective image and thus no true scaling information can be directly deduced from it. In this article, an approach based on an interferometric setup, a low-coherence laser source and a standard rigid endoscope is presented, and applied to hollow samples measurements. More generally, the use of the low-coherence interferometric setup detailed here could be extended to any other endoscopy-related field of interest, e.g., gastroscopy, arthroscopy and other medical or industrial applications where tri-dimensional topology is required. The setup design with a multiple fibers illumination system is presented. Demonstration of the method ability to operate on biological samples is assessed through measurements on ex vivo pig bronchi.

Response-to-comments about: "Is it really the method for carbon dioxide determination in human postmortem cardiac gas samples using Headspace-Gas Chromatography-Mass Spectrometry valid?" from T. Saffaj and B. Ihssane

Saffaj et al. recently criticized our method of monitoring carbon dioxide in human postmortem cardiac gas samples using Headspace-Gas Chromatography-Mass Spectrometry. According to the authors, their demonstration, based on the latest SFSTP guidelines (established after 2007 [1,2]) fitted for the validation of drug monitoring bioanalytical methods, has put in evidence potential errors. However, our validation approach was built using SFSTP guidelines established before 2007 [3-6]. We justify the use of these guidelines because of the post-mortem context of the study (and not clinical) and the gaseous state of the sample (and not solid or liquid). Using these guidelines, our validation remains correct.

Compact portable biosensor for arsenic detection in aqueous samples with Escherichia coli bioreporter cells.

We present a compact portable biosensor to measure arsenic As(III) concentrations in water using Escherichia coli bioreporter cells. Escherichia coli expresses green fluorescent protein in a linearly dependent manner as a function of the arsenic concentration (between 0 and 100 μg/L). The device accommodates a small polydimethylsiloxane microfluidic chip that holds the agarose-encapsulated bacteria, and a complete optical illumination/collection/detection system for automated quantitative fluorescence measurements. The device is capable of sampling water autonomously, controlling the whole measurement, storing and transmitting data over GSM networks. We demonstrate highly reproducible measurements of arsenic in drinking water at 10 and 50 μg/L within 100 and 80 min, respectively.