Simple and field-adapted species identification of biological specimens combining multiplex multienzyme isothermal rapid amplification, lateral flow dipsticks, and universal primers for initial rapid screening without standard PCR laboratory.

Species identification of biological specimens can provide the valuable clues and accelerate the speed of prosecution material processing for forensic investigation, especially when the case scene is inaccessible and the physical evidence is cumbersome. Thus, establishing a rapid, simple, and field-adapted species identification method is crucial for forensic scientists, particularly as first-line technology at the crime scene for initial rapid screening. In this study, we established a new field-adapted species identification method by combining multiplex multienzyme isothermal rapid amplification (MIRA), lateral flow dipstick (LFD) system, and universal primers. Universal primers targeting COX I and COX II genes were used in multiplex MIRA-LFD system for seven species identification, and a dedicated MIRA-LFD system primer targeting CYT B gene was used to detect the human material. DNA extraction was performed by collecting DNA directly from the centrifuged supernatant. Our study found that the entire amplification process took only 15 min at 37 °C and the results of LFDs could be visually observed after 10 min. The detection sensitivity of human material could reach 10 pg, which is equivalent to the detection of single cell. Different common animal samples mixed at the ratio of 1 ng:1 ng, 10 ng:1 ng, and 1 ng:10 ng could be detected successfully. Furthermore, the damaged and degraded samples could also be detected. Therefore, the convenient, feasible, and rapid approach for species identification is suitable for popularization as first-line technology at the crime scene for initial rapid screening and provides a great convenient for forensic application.

Vasospasm after subarachnoid hemorrhage: a 3D rotational angiography study.

BACKGROUND AND PURPOSE: the purpose of this study was to investigate the clinical value of 3D rotational angiography (3DRA) for evaluation of cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH) by comparison with 2D digital subtraction angiography (DSA). METHODS: forty-six patients who had undergone 2D DSA and 3DRA for evaluation of cerebral vasospasm following SAH were retrospectively analyzed. 3DRA was routinely performed after standard 2D DSA. 3D volume rendering images were created from 3DRA dataset and compared with DSA for the detection and characterization of vasospasm. RESULTS: Of the 46 patients investigated, 25 had vasospasm on 2D DSA images. No vasospasm was observed in 21 patients with aneurysmal SAH. According to the reference standard of DSA, 46 spastic segments were found in 25 patients with vasospasms. A total of 51 spastic segments were found on 3DRA volume rendering angiograms. The sensitivity, specificity, positive and negative predictive values of 3DRA for detecting vasospasm were 100, 76, 90, 100%, respectively. CONCLUSION: the pseudo-spasm phenomenon was frequently observed on 3DRA volume rendering images. 3DRA was less useful than 2D DSA for evaluation of vasospasm after SAH.