Systematic endoscopic assessment of bleeding sites in severe epistaxis: the role of the S-point and the superior epistaxis

BACKGROUND

Systematic endoscopic assessment (SEA) of bleeding sites is critical for topodiagnosis and treatment of severe epistaxis, which is not limited to the posterior region. A bleeding site originating from the ethmoidal vasculature, the S-point, has recently been described. The aim of this study is to ascertain the prevalence of each bleeding site in severe epistaxis using a SEA protocol that includes the S-point.

METHODOLOGY

Prospective longitudinal study of 51 severe epistaxis patients who underwent 53 SEA under general anesthesia from April 2018 through March 2019. SEA consisted of use of a rigid nasal endoscope; no reduction in blood pressure; no use of topical vasoconstrictor; systematic search of all regions of the nose. Bleeding sites were assigned to either superior or posterior epistaxis.

RESULTS

At least one bleeding site was identified in 37 evaluations (69.8%). The S-point was the most common bleeding site (28.3%), followed by the lateral middle turbinate (9.4%), non-S-point upper septum (7.5%), nasal roof (7.5%), and upper lateral wall (7.5%). Superior epistaxis was identified in the most of cases (27 SEA, 50.9%), whereas only 14 SEA (26.4%) identified posterior epistaxis â€" fewer than the 16 SEA that did not identify any bleeding sites (30.2%). There were two recurrences (3.8%).

CONCLUSIONS

Systematic endoscopic assessment effectively identified bleeding sites in 69.8% of severe epistaxis. The S-point was the most common bleeding site identified (28.3%). Finally, superior epistaxis corresponded to more than half of the identified bleeding sites, demonstrating the importance of examining this region judiciously in patients with severe epistaxis.

Analysis of uni and bi-parental markers in mixture samples: Lessons from the 22nd GHEP-ISFG Intercomparison Exercise

Since 1992, the Spanish and Portuguese-Speaking Working Group of the ISFG (GHEP-ISFG) has been organizing annual Intercomparison Exercises (IEs) coordinated by the Quality Service at the National Institute of Toxicology and Forensic Sciences (INTCF) from Madrid, aiming to provide proficiency tests for forensic DNA laboratories. Each annual exercise comprises a Basic (recently accredited under ISO/IEC 17043: 2010) and an Advanced Level, both including a kinship and a forensic module. Here, we show the results for both autosomal and sex-chromosomal STRs, and for mitochondrial DNA (mtDNA) in two samples included in the forensic modules, namely a mixture 2:1 (v/v) saliva/blood (M4) and a mixture 4:1 (v/v) saliva/semen (M8) out of the five items provided in the 2014 GHEP-ISFG IE. Discrepancies, other than typos or nomenclature errors (over the total allele calls), represented 6.5% (M4) and 4.7% (M8) for autosomal STRs, 15.4% (M4) and 7.8% (M8) for X-STRs, and 1.2% (M4) and 0.0% (M8) for Y-STRs. Drop-out and drop-in alleles were the main cause of errors, with laboratories using different criteria regarding inclusion of minor peaks and stutter bands. Commonly used commercial kits yielded different results for a micro-variant detected at locus D12S391. In addition, the analysis of electropherograms revealed that the proportions of the contributors detected in the mixtures varied among the participants. In regards to mtDNA analysis, besides important discrepancies in reporting heteroplasmies, there was no agreement for the results of sample M4. Thus, while some laboratories documented a single control region haplotype, a few reported unexpected profiles (suggesting contamination problems). For M8, most laboratories detected only the haplotype corresponding to the saliva. Although the GHEP-ISFG has already a large experience in IEs, the present multi-centric study revealed challenges that still exist related to DNA mixtures interpretation. Overall, the results emphasize the need for further research and training actions in order to improve the analysis of mixtures among the forensic practitioners.

Rapid Affinity Purification Processes for Cyclodextrin Glycosyltransferase from Bacillus circulans

Two rapid and easy-to-scale-up methods for the purification of cyclodextrin glycosyltransferase (CGTase) from Bacillus circulans were developed: affinity precipitation with starch and aqueous two-phase partition. The first method, optimised by a factorial design, gave an 80% CGTase adsorption at 11% starch and 1.6% ammonium sulphate, and a 65% recovery after elution with 10 mM alpha-cyclodextrin. The purification factor was 17. Aqueous two-phase partition yielded a 72% CGTase recovery in a two-step procedure; CGTase was obtained in the bottom phase with a purification factor of 37.

Purification of a lipase from Acinetobacter calcoaceticus AAC323-1 by hydrophobic-interaction methods

The performance of hydrophobic-interaction chromatography (HIC) for the purification of Acinetobacter calcoaceticus AAC323-1 lipase was compared with that of various aqueous two-phase systems. While a 42% lipase yield with a purification factor of 140 could be recovered by HIC, higher yields were achieved by using aqueous two-phase systems, either those formed by poly(ethylene glycol) and dextran or those based upon the use of a detergent. Triton X-114-based aqueous two-phase partition showed the best performance, with a yield of 81% and a purification factor of 68. Further detergent removal was easily achieved with an adsorbent, with no significant decrease in yields. Owing to its simplicity, the method should be easy to scale-up.