The position and role of department of laboratory medicine in the construction of national public health system: experiences from public health emergencies efforts / 中华检验医学杂志

At present, the situation of COVID-19 epidemic prevention and control in China is gradually improving, but the situation of overseas import prevention and control remains difficult. The COVID-19 epidemic may exist for long due to the undetermined source of infection, the difficulty in completely cutting off the transmission route, and a large number of susceptible people. Therefore, prevention and control will be a long-term and arduous task, making it necessary to adhere to the principle of combining emergency response with regular prevention and control, coordinating the epidemic prevention and social-economic development in a balanced way. In retrospect, the epidemic has exposed the ambiguous positioning and unsatisfying hardware construction of hospital laboratory departments, and delayed intervention of laboratory experts in the public health treatment system of China. This paper reflects on the hospital laboratory departments′ problems during the anti-epidemic activities, and put forward suggestions to improve the future development of clinical laboratories in the national public health system.

Sensitive fluorescence assay of organophosphorus pesticides based on the fluorescence resonance energy transfer between CdTe quantum dots and porphyrin.

A sensitive and selective quantum dot (QD)-based fluorescence resonance energy transfer (FRET) biosensor was successfully fabricated for the detection of organophosphorus pesticides (OPs). 5,10,15,20-Tetra(4-pyridyl)porphyrin (TPyP) with meso-pyridyl substituents was bound to the surface of CdTe QDs to produce self-assembled nanosensors, and the process of FRET between QDs and TPyP occurred. However, the process of FRET was switched off with the addition of OPs, due to the combination between TPyP and OPs. The fluorescence intensity of TPyP (donor) would decrease gradually with the increasing concentration of OPs. Under optimal conditions, a linear correlation was established between the fluorescence intensity ratio ITPyP/IQDs and the concentration of paraoxon in the range of 9.09 × 10(-12)-1.09 × 10(-6) mol L(-1) with a detection limit of 3.15 × 10(-12) mol L(-1). The attractive sensitivity was obtained due to the efficient FRET and the superior fluorescence properties of QDs. The proposed method was successfully applied to the determination of the OPs in real fruit samples with satisfactory results.

Highly-sensitive organophosphorus pesticide biosensors based on CdTe quantum dots and bi-enzyme immobilized eggshell membranes.

An optical biosensing method using CdTe quantum dots (QDs) and bi-enzyme-immobilized eggshell membranes for the determination of organophosphorus pesticides (OPs) has been developed. Increasing amounts of OPs led to a decrease of the enzymatic activity and thus a decrease in the production of hydrogen peroxide (H2O2), which can quench the fluorescence of the CdTe QDs. Under the optimum conditions, there was a good linear relationship between the enzyme inhibition percentage and the logarithm of paraoxon or parathion concentration in the range of 1.0 × 10(-11)-1.0 × 10(-6) mol L(-1). The detection limit (S/N = 3) of the proposed biosensors were as low as 4.30 × 10(-12) mol L(-1) for paraoxon and 2.47 × 10(-12) mol L(-1) for parathion. The bi-enzyme-immobilized eggshell membrane demonstrated a long shelf-life of at least 2 months and the results showed good repeatability. The proposed method was successfully applied to the determination of the OPs in real fruit samples with satisfactory results.

HOTAIR Interacting with MAPK1 Regulates Ovarian Cancer skov3 Cell Proliferation, Migration, and Invasion.

BACKGROUND: The aim of this study was to evaluate the effect of when silencing HOTAIR in ovarian cancer skov3 cells on proliferation, migration, and invasion, and to elucidate the mechanism by which this occurs. MATERIAL AND METHODS: We detected the mRNA level of HOTAIR (HOX antisense intergenic RNA) and MAPK1 (mitogen-activated protein kinase 1) in ovarian cancer SKOV3, ES-2, OVCAR3, A2780, and COC1 cell lines. We detected the mRNA level of HOTAIR and MAPK1 in ovarian SKOV3 when transected with miR-1, miR-214-3p, or miR-330-5p. We detected the mRNA and protein level of MAPK1 when silencing HOTAIR. We detected the expression of HOTAIR when silencing MAPK1. Then we detected the proliferation, migration, and invasion in ovarian cancer skov3 after silencing HOTAIR or MAPK1. RESULTS: The expression of HOTAIR and MAPK1 in ovarian SKOV3, ES-2, and OVCAR3 increased compared with A2780 and COC1 cells (P<0.05). The mRNA level of HOTAIR and MAPK1 in ovarian SKOV3 decreased when transected with miR-1, miR-214-3p, or miR-330-5p compared to negative control (p<0.05). The mRNA and protein level of MAPK1 was decreased when silencing HOTAIR and the mRNA level of HOTAIR was decreased when silencing MAPK1 (p<0.05). The proliferation, migration, and invasion was inhibited in ovarian SKOV3 after silencing HOTAIR or MAPK1 (p<0.05). CONCLUSIONS: HOTAIR can promote proliferation, migration, and invasion in ovarian SKOV3 cells as a competing endogenous RNA.

Comparison of five methods used for detection of Clostridium difficile infection / 中华检验医学杂志

Objective To evaluate five detection methods for the laboratory diagnosis of Clostridium difficile infection in the hospitals of USA, and explore a sensitive, specific, accuracy and rapid regimen for the early diagnosis of Clostridium difficile infection. Methods A total of 174 stool specimens submitted to the clinical microbiology laboratory for Clostridium difficile testing were separately tested by five methods including toxigenic culture (TGC), Premier Toxin A&B EIA( A/B-EIA), C. Diff Quick Chek Complete( DEIA), BD G eneOhm Cdiff assay(BD-PCR) and Laboratory-developed PCR(LD-PCR). The gold standard of TGC was used as a reference criterion, and the sensitivity, specificity, positive predictive value ( PPV )and negative predictive value (NPV) of A/B-EIA, D-EIA, BD-PCR and LD-PCR assays were determined. Results Among the 174 specimens studied, 24 were defined as true positives for Clostridium difficile infection by TGC assay, giving a positive rate of 13.8% (24/174). In comparison to the standard,the sensitivity, specificity, PPV and NPV were 62.5%, 99.3%, 93.8% and 94.3% for A/B-EIA;66.7%, 98.7%, 88.9% and 94.9% for D-EIA; 83.3%, 98.7%, 90.9% and 97.4% for BD-PCR;79.2%, 93.3%, 65.5% and 96.6% for LD-PCR. Among all tested specimens, 34 were positive by atleast one of five methods, and of which 15 were concordant by all five methods. The D-EIA results were divided into three groups depending on results of GDH and (or) toxins A/B: 18 were positive for both GDH and toxins A/B, 23 were positive for only GDH, and 133 were negative for both GDH and toxins A/B. Of 18 positive specimens by D-EIA assay, all were concordant with results of BD-PCR assay and 16 were agreement with results of TGC assay. Twenty-two of 24 positive specimens by TGC assay were included in 41 specimens that were positive for GDH. Among eight false negative specimens by D-EIA assay, four were differentiated as positive results by BD-PCR. According to the present study, the sensitivity, specificity,PPV and NPV of a two-step detection algorithm in combination with D-EIA and BD-PCR assays were 83.3%, 98.7%, 90.9% and 97.4%, respectively. Conclusions From the point of technological evaluation, BD-PCR is preferable. A two-step detection algorithm combining D-EIA with BD-PCR is proposed for the laboratory diagnosis of Clostridium difficile infection. This algorithm has demonstrated an excellent sensitivity and specificity, as well as decreased test turnaround time and test cost.