Metabolomics efficiently discriminates monozygotic twins in peripheral blood.

Monozygotic (MZ) twins cannot be distinguished using conventional forensic STR typing because they present identical STR genotypings. However, MZ twins do not always live in the same environment and often have different dietary and other lifestyle habits. Metabolic profiles are deyermined by individual characteristics and are also influenced by the environment in which they live. Therefore, they are potential markers capable of identifying MZ twins. Moreover, the production of proteins varies from organism to organism and is influenced by both the physiological state of the body and the external environment. Hence, we used metabolomics and proteomics to identify metabolites and proteins in peripheral blood to discriminate MZ twins. We identified 1749 known metabolites and 622 proteins in proteomic analysis. The metabolic profiles of four pairs of MZ twins revealed minor differences in intra-MZ twins and major differences in inter-MZ twins. Each pair of MZ twins exhibited distinct characteristics, and four metabolites-methyl picolinate, acesulfame, paraxanthine, and phenylbenzimidazole sulfonic acid-were observed in all four MZ twin pairs. These four differential exogenous metabolites conincidently show that the different external environments and life styles can be well distinguished by metabolites, considering that twins do not all have the same eating habits and living environments. Moreover, MZ twins showed different protein profiles in serum but not in whole blood. Thus, our results indicate that differential metabolites provide potential biomarkers for the personal identification of MZ twins in forensic medicine.

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.

Discrimination of monozygotic twins using mtDNA heteroplasmy through probe capture enrichment and massively parallel sequencing.

Differentiating between monozygotic (MZ) twins remains difficult because they have the same genetic makeup. Applying the traditional STR genotyping approach cannot differentiate one from the other. Heteroplasmy refers to the presence of two or more different mtDNA copies within a single cell and this phenomenon is common in humans. The levels of heteroplasmy cannot change dramatically during transmission in the female germ line but increase or decrease during germ-line transmission and in somatic tissues during life. As massively parallel sequencing (MPS) technology has advanced, it has shown the extraordinary quantity of mtDNA heteroplasmy in humans. In this study, a probe hybridization technique was used to obtain mtDNA and then MPS was performed with an average sequencing depth of above 4000. The results showed us that all ten pairs of MZ twins were clearly differentiated with the minor heteroplasmy threshold at 1.0%, 0.5%, and 0.1%, respectively. Finally, we used a probe that targeted mtDNA to boost sequencing depth without interfering with nuclear DNA and this technique can be used in forensic genetics to differentiate the MZ twins.

[Effect of differentarterial occlusion pressure and intermittent mode on KAATSU-loaded deep-squat exercise on the characteristics of thigh muscle activation].

Objective: To investigate the effect of different arterial occlusion pressure and intermittent time on KAATSU-loaded deep-squat exercise on the characteristics of thigh muscle activation, find out the suitable relative value of personal blood pressure limit causing the maximum activation, and to provide some theoretical basis and practical reference for athletes to carry on the KAATSU Training scientifically. Methods: Ten elite male players were recruited, four kinds of external pressure condition with 0% arterial occlusion pressure (AOP), 40%AOP, 50%AOP, 60%AOP, respectively, were performed with 30%1RM(One repetition maximum)intensity of intermittent and continuous KAASTU-loaded deep-squat exercise. Wave plus wireless surface electromyography instrument was used to collect the surface EMG signals of the lower thigh muscle group. Root mean square (RMS) calculation was used to estimate muscle activity level. The normalized RMS values of the anterior thigh group and posterior thigh group were calculated by RMS of MVC, two-factor ANOVA analysis of variance were used to explore the effect of the activation of various muscle on external express and intermittent mode, to analyze the discrepancy during different external pressure. Results: ①A two-factor analysis of variance showed that different %AOP had significant effect on the normalized values of RMS of muscle measured by KAATSU deep-squat exercise(P＜0.05), but intermittent mode had no significant effect on the standard value of RMS of muscle(P＞0.05). The interaction of external pressure and intermittent mode on muscle RMS was not significant(P＞0.05); ②The normalized RMS values of Rectus Femoris, Vastus Medialis, Vastus Lateralis, Biceps Femoris, Semitendinosus were significantly increased (P＜0.05)in 50% AOP pressure condition during intermittent and continuous exercise; ③ The normalized RMS values of RF and VL were significantly increased(P＜0.05)in 50% AOP pressure condition during intermittent and continuous exercise. The %MVC values of Vastus Medialis and Semitendinosus were significantly increased(P＜0.05)in 60% AOP pressure condition during intermittent exercise. Conclusion: This study further verified that 50% AOP pressure can significantly improve the optimal activation quadriceps and posterior thigh groups and produce the best training effect for the high level handball players. It can not only promote the coordinated development of the agonist and antagonist, but also avoid overloading and prevent hamstring injury. At the same time, the intermittent mode is recommended to adopt the decompression intermittent mode.

Surgical treatment of foreign body embolus in the Middle cerebral artery secondary to neck injury.

Background: We report a case of a foreign body embolus to the middle cerebral artery and reviewed similar cases previously reported. Methods: A 30-year-old man was seen 72 days after a penetrating neck injury with a 1-month history of numbness in the left limb and impairment of the fine movement in the left hand. Radiological examination revealed a foreign body in the M2 portion of the right middle cerebral artery (MCA). The patient received arteriotomy and in situ suturing. Results: During the operation, we found a metallic foreign body at the bifurcation of the M2 upper trunk of the right MCA, narrowed distal blood vessels and thinned vessel walls. The foreign body was surrounded by granulation tissue. Both foreign body and granulation tissue were removed slowly followed by in situ suturing. Indocyanine green angiography confirmed arterial patency. Three days after the surgery, the patient developed numbness and weakness in the left arm, with a muscle strength of grade 4. Computed tomography showed partial infarction in the right temporal lobe. Then, antispasmodic drugs were used. Muscle strength recovered by 14 days after the operation. Conclusions: In the subacute stage, surgery can be conducted to remove intra-arterial foreign bodies along with their surrounding granulation tissue if computed tomography perfusion suggests a decreased blood flow reserve capacity.