Application of digital PCR technology in the precise molecular diagnosis: opportunities and challenges / 中华检验医学杂志

Digital polymerase chain reaction (dPCR) is an absolute quantitative technique that has been rapidly developed in recent years. This technique assigns the reaction system containing DNA template to a large number of independent reaction units for PCR, and calculates the DNA copy number according to the Poisson distribution and statistical positive signals. In contrast to conventional qPCR, dPCR does not depend on amplification curves, is not affected by amplification efficiency, thus has high accuracy and repeatability, and can achieve the absolute quantification. This article reviews the development history of dPCR and its application in molecular diagnosis, tumor liquid biopsy and prenatal diagnosis of infectious diseases, and looks forward to the application prospect of this technology.

Reliability of lactate clearance rate in evaluating efficacy of early fluid resuscitation in patients with severe sepsis / 中华麻醉学杂志

Objective To evaluate the reliability of lactate clearance rate in evaluating the efficacy of early fluid resuscitation in the patients with severe sepsis.Methods One hundred and forty-two patients with severe sepsis,aged 28-87 yr,were enrolled in the study.Isotonic crystalloid fluid was infused after admission to ICU to maintain central venous pressure ≥ 8 mmHg,mean arterial pressure ≥ 65 mmHg,central venous oxygen saturation (ScvO2) ≥ 70％,and urine output ≥ 0.5 ml·kg 1 ·h-1 within 6 h.The patients were divided into 2 groups according to the treatment outcome:survival group and death group.Immediately before fluid resuscitation and at 6,12 and 24 h after fluid resuscitation,blood samples were collected from the central vein for blood gas analysis and ScvO2 was recorded.Blood samples were collected from the peripheral vein for determination of the concentration of lactate and lactate clearance rate was calculated.Results Compared with survival group,the lactate clearance rate was significantly decreased at 6,12 and 24 h after fluid resuscitation,and no significant change in ScvO2 was found in death group.Conclusion Lactate clearance rate can evaluate the efficacy of early fluid resuscitation in the patients with severe sepsis.