Antibody responses to SARS-CoV-2 in COVID-19 patients: the perspective application of serological tests in clinical practice

BackgroundWe aim to investigate the profile of acute antibody response in COVID-19 patients, and provide proposals for the usage of antibody test in clinical practice. MethodsA multi-center cross-section study (285 patients) and a single-center follow-up study (63 patients) were performed to investigate the feature of acute antibody response to SARS-CoV-2. A cohort of 52 COVID-19 suspects and 64 close contacts were enrolled to evaluate the potentiality of the antibody test. ResultsThe positive rate for IgG reached 100% around 20 days after symptoms onset. The median day of seroconversion for both lgG and IgM was 13 days after symptoms onset. Seroconversion of IgM occurred at the same time, or earlier, or later than that of IgG. IgG levels in 100% patients (19/19) entered a platform within 6 days after seroconversion. The criteria of IgG seroconversion and > 4-fold increase in the IgG titers in sequential samples together diagnosed 82.9% (34/41) of the patients. Antibody test aided to confirm 4 patients with COVID-19 from 52 suspects who failed to be confirmed by RT-PCR and 7 patients from 148 close contacts with negative RT-PCR. ConclusionIgM and IgG should be detected simultaneously at the early phase of infection. The serological diagnosis criterion of seroconversion or the >; 4-fold increase in the IgG titer is suitable for a majority of COVID-19 patients. Serologic test is helpful for the diagnosis of SARS-CoV-2 infection in suspects and close contacts.

Faster R-CNN-based artificial intelligence image-aided diagnosis platform in identifying EMVI of rectal cancer: A multicenter clinical study / 中国实用外科杂志

OBJECTIVE: To explore the clinical application value of artificial intelligence image aided diagnosis platformbased on Faster R-CNN in identifying EMVI of rectal cancer.METHODS: In the multicenter retrospective study,500 patients with rectal cancer who underwent high-resolution MRI examination between July 2016 and February 2019 wereselected from seven hospitals in China. They were divided into 174 positive and 326 negative patients. Patients wererandomized to a training group(400 patients,including 133 positive and 267 negative) and a validation group(100 patients,including 41 positive and 59 negative) using a random number method. Using the Faster R-CNN to learn and train 20 430 high-resolution MRI images of thetraining group,an artificial intelligence image-aided diagnosis platform was established. The5107 high-resolution MRI images of thevalidation group were clinically validated.Receiver operating characteristic(ROC) curveand area under the curve(AUC) were used tocompare the diagnostic results of the artificialintelligence image-aided diagnosis platform andthe senior image expert.RESULTS: The accuracy,sensitivity,specificity,positive predictive valueand negative predictive value of EMVI forartificial intelligence image-aided diagnosis platform were 93.4%, 97.3%, 89.5%, 0.90 and 0.97,respectively. The area under the receiver operating characteristiccurve(AUC) was 0.98. The time required to automatically recognize a single image was 0.2 seconds,which had clearadvantages compared to radiologists(estimated to be about 10 seconds).CONCLUSION: The artificial intelligence image-assisted diagnosis platform based on Faster R-CNN has high efficiency and feasibility for identifying rectal cancerEMVI,and can assist imaging diagnosis.

Analysis of the protein expression and gene amplification of HER2 in gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the clinical significance of protein expression and gene amplification of HER2 in gastric cancer.</p><p><b>METHODS</b>Immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) method were used to detect protein expression and gene amplification of HER2 in 80 specimens of gastric cancer patients.</p><p><b>RESULTS</b>Protein expression of HER2 was negative in 51 cases, (+) in 12 cases, (++) in 12 cases, (+++) in 5 cases, and the positive expression rate was 21.3% (17/80). Seven (8.8%) cases had gene amplification of HER2, including gene critical amplification in 3 (3.8%) cases. The result of IHC was positively correlated with CISH (P<0.05), and the coincidence rate was 85.0% (68/80). HER2 positive expression rate was higher in the gastroesophageal junction carcinoma, poorly differentiated and stage III-IIII gastric cancer (all P<0.05).</p><p><b>CONCLUSION</b>The gastric cancer tissue has high positive rate of protein expression and gene amplification of HER2, which is closely correlated to the development of gastric cancer.</p>

Expression of ZBTB8A in gastric cancer and its clinical significance / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the expression of ZBTB8A (zinc finger and BTB domain containing 8A) in gastric cancer tissues and its clinical significance.</p><p><b>METHODS</b>Level of ZBTB8A mRNA in human normal gastric cell line GES-1, human gastric cancer cell line SGC7901 and MGC803 was detected by real-time PCR. Levels of ZBTB8A mRNA and protein in cancer tissues, adjacent cancer tissues from 104 cases with primary gastric cancer and normal gastric mucosal tissues from 40 cases without malignant gastric diseases were detected by RT-PCR and immunohistochemistry, respectively. Association between ZBTB8A expression and clinicopathology was analyzed.</p><p><b>RESULTS</b>ZBTB8A mRNA expressions in SGC7901, MGC803 and GES-1 cells were 0.00138±0.00015, 0.00158±0.00021, 0.00036±0.000055, respectively, and differences among SGC7901, MGC803 and GES-1 were significant respectively (all P<0.05). ZBTB8A mRNA expression was significantly up-regulated in cancer tissues as compared to adjacent cancer tissues and normal tissues (0.0152±0.0126 vs. 0.0070±0.0061 and 0.0079±0.0036, all P>0.05), while no significant difference was found between adjacent cancer tissues and normal tissues (P>0.05). ZBTB8A expression was significantly associated with invasive depth, lymph node metastasis, tumor stage, and degree of adenocarcinoma differentiation (all P<0.05), but not with age, gender, histological type,gross type (all P>0.05).</p><p><b>CONCLUSION</b>ZBTB8A may be a potential carcinogenic factor in gastric carcinoma, and may also be involved in gastric adenocarcinoma cell differentiation, cancer invasion and metastasis.</p>