The spike-ACE2 binding assay: An in vitro platform for evaluating vaccination efficacy and for screening SARS-CoV-2 inhibitors and neutralizing antibodies.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 has become a worldwide pandemic, and there is a pressing need for the rapid development of novel therapeutic strategies. SARS-CoV-2 viral entry is mediated by interaction between the receptor binding domain (RBD) of the SARS-CoV-2 Spike protein and host cellular receptor, human angiotensin converting enzyme 2 (ACE2). The lack of a high throughput screening (HTS) platform for candidate drug screening means that no targeted COVID-19 treatments have been developed to date. To overcome this limitation, we developed a novel, rapid, simple, and HTS binding assay platform to screen potential inhibitors of the RBD-ACE2 complex. Three "neutralizing" mouse monoclonal antibodies capable of blocking the RBD-ACE2 interaction were identified using our binding assay and pseudovirus neutralization assay followed by further validation with the Focus Reduction Neutralization Test (FRNT), which analyzes the neutralization capacity of samples in the presence of live SARS-CoV-2. Furthermore, the consistency of our binding assay and FRNT results (R2 = 0.68) was demonstrated by patients' serum, of which were COVID-19 positive (n = 34) and COVID-19 negative (n = 76). Several small molecules selected for their potential to inhibit the Spike-ACE2 complex in silico were also confirmed with the binding assay. In addition, we have evaluated vaccine efficacy using binding assay platform and validated through pseudovirus neutralization assay. The correlation between binding assay & psuedovirus assay of the post vaccinated serum showed well correlated (R2 = 0.09) Moreover, our binding assay platform successfully validated different Spike RBD mutants. These results indicate that our binding assay can be used as a platform for in vitro screening of small molecules and monoclonal antibodies, and high-throughput assessment of antibody levels after vaccination. When conducting drug screening, computer virtual screening lacks actual basis, construction of pseudoviruses is relatively complicated, and even FRNT requires a P3 laboratory. There are few methods to determine the competitiveness of the target drug and SRBD or ACE2. Our binding assay can fill this gap and accelerate the process and efficiency of COVID-19 drug screening.

Pancreatic Schwannoma on FDG PET/CT.

A 55-year-old woman underwent FDG PET/CT to evaluate a pancreatic mass. The images showed elevated FDG activity in the uncinated process of the pancreas, suggestive of malignancy. However, pathological examination from the resected lesion demonstrated pancreatic schwannoma.

Association study and expression analysis of CYP4A11 gene copy number variation in Chinese cattle.

The identification of copy number variations (CNVs) allow us to explore genomic polymorphisms. In recent years, significant progress in understanding CNVs has been made in studies of human and animals, however, association and expression studies of CNVs are still in the early stage. It was previously reported that the Cytochrome P-450 4A11 (CYP4A11) gene is located within a copy number variable region (CNVR) that encompasses quantitative trait loci (QTLs) for economic traits like meat quality and milk production. So, this study was performed to determine the presence of CYP4A11 CNV in six distinct cattle breeds, identify its relationship with growth, and explore the biological effects of gene expression. For three CYP4A11 CNV types, Normal was more frequent than Gain or Loss. Association analysis revealed a positive effect of CYP4A11 copy number on growth traits (P < 0.05). One-way analysis of variance (ANOVA) analysis revealed that more CYP4A11 copies increased the gene expression level. Moreover, overexpression of CYP4A11 in vitro revealed its effect on lipid deposit. The data provide evidence for the functional role of CYP4A11 CNV and provide the basis for future applications in cattle breeding.

Focal hepatic 11C-acetate activity on PET/CT scan due to lymphoid hyperplasia.

A 69-year-old woman complaining of abdominal bloating underwent ultrasonography, which revealed a small lesion in the left lobe of the liver. The lesion had elevated activity of both 18F-FDG and 11C-acetate on PET/CT scan and was suspected of being malignant. Postresection pathological examination demonstrated that this lesion was a focal intrahepatic lymphoid hyperplasia.

Application of dual phase imaging of 11C-acetate positron emission tomography on differential diagnosis of small hepatic lesions.

OBJECTIVE: Previously we observed that dual phase 11C-acetate positron emission tomography (AC-PET) could be employed for differential diagnosis of liver malignancies. In this study, we prospectively evaluated the effect of dual phase AC-PET on differential diagnosis of primary hepatic lesions of 1-3 cm in size. METHODS: 33 patients having primary hepatic lesions with size of 1-3 cm in diameter undertook dual phase AC-PET scans. Procedure included an early upper-abdomen scan immediately after tracer injection and a conventional scan in 11-18 min. The standardized uptake value (SUV) was calculated for tumor (SUVT) and normal tissue (SUVB), from which 11C-acetate uptake ratio (as lesion against normal liver tissue, SUVT/SUVB) in early imaging (R1), conventional imaging (R2), and variance between R2 and R1 (ΔR) were derived. Diagnoses based on AC-PET data and histology were compared. Statistical analysis was performed with SPSS 19.0. RESULTS: 20 patients were found to have HCC and 13 patients had benign tumors. Using ΔR>0 as criterion for malignancy, the accuracy and specificity were significantly increased comparing with conventional method. The area under ROC curve (AUC) for R1, R2, and ΔR were 0.417, 0.683 and 0.831 respectively. Differential diagnosis between well-differentiated HCCs and benign lesions of FNHs and hemangiomas achieved 100% correct. Strong positive correlation was also found between R1 and R2 in HCC (r2 = 0.55, P<0.001). CONCLUSIONS: Dual phase AC-PET scan is a useful procedure for differential diagnosis of well-differentiated hepatocellular carcinoma and benign lesions. The dynamic changes of 11C-acetate uptake in dual phase imaging provided key information for final diagnosis.

LyGDI is a promising biomarker for ovarian cancer.

INTRODUCTION: LyGDI is an inhibitor of Rho protein activation by blocking its transformation between guanosine 5'-diphosphate- and guanosine 5'-triphosphate-bound states. The aim of this study was to investigate the usefulness of LyGDI as a biomarker for the detection of ovarian cancer, and its specificity and sensitivity were compared with those of cancer antigen 125 (CA125). METHODS: The serum levels of LyGDI were determined by enzyme-linked immunosorbent assay in 42 patients with ovarian disease, including 30 ovarian cancers and 12 benign ovarian lesions, and 76 healthy controls. The expression of LyGDI was also evaluated by immunohistochemical staining in resected ovarian tissues of these patients. RESULTS: The serum LyGDI level of cancers was significantly greater than those of the benign and healthy groups (P = 0.002 and P < 0.0001, respectively), whereas no difference was observed between the benign and control groups (P = 0.889). Based upon receiver operating characteristic curve analysis, LyGDI levels were able to distinguish ovarian cancer from benign ovarian disease (P = 0.0001) and healthy control (P < 0.0001; areas under the receiver operating characteristic curves, 0.876 and 0.833, respectively). For ovarian cancers, 83.3% (25/30) or 80.0% (24/30) was identified by serum LyGDI (> or = 1.5 ng/mL) alone or by CA125 (>35 U/mL) alone. It is of particular importance to note that all cancer patients were identified by use of both markers, and the specificity was 83.3% for the benign group. Moreover, in early-stage cancers, 88.9% (8/9) had elevated serum LyGDI levels as compared with 44.4% (4/9) elevation of CA125 levels (P = 0.125). Immunohistochemical staining confirmed the expression of LyGDI on cancerous epithelial cells other than benign ovarian epithelium. CONCLUSIONS: These results suggest that LyGDI has significant potential as a marker for detection of ovarian cancer in the patients with ovarian enlargement, including detection of early-stage cancers.

[Analysis of in-hospital morbidity and mortality of colorectal cancer and accuracy of POSSUM models for mortality risk].

OBJECTIVE: To develop the modified P-POSSUM equation and the modified Cr-POSSUM equation and compare their performances with POSSUM in forecasting in-hospital morbidity and mortality of colorectal cancer. METHODS: Data of 903 patients undergone operation of colon and rectal cancers from 1992 to 2005 in our department were enrolled in this study. ROC curve was applied to judge the differentiation ability of each score. Model goodness-or-fit was tested by the Hosmer-Lemeshow statistic and subgroup analysis was performed by the ratio of observed to expected deaths (O:E ratio). A 70:30 percent split-sample validation technique was adopted for model development and testing. Stepwise logistic regression was used to develop the modified P-POSSUM and the modified Cr-POSSUM. Their performance in validating sample, colonic cancer sample, rectal cancer sample, elective surgery sample, emergency surgery sample, curative surgery sample and palliative surgery sample was tested by ROC curve, Hosmer-Lemeshow statistic and O:E ratio. RESULTS: The modified P-POSSUM showed good discrimination in all samples except the emergency surgery and palliative surgery. The predicted mortality of modified P-POSSUM was very close to the observed mortality. However, the modified Cr-POSSUM showed good discrimination in all samples except the palliative surgery. The predicted mortality was higher than the observed mortality, but still within the 95% confidence interval (CI) of the observed mortality. Both the modified models offered better accuracy than the P-POSSUM. CONCLUSION: The modified P-POSSUM and the modified Cr-POSSUM model provide an accurate prediction of inpatient mortality in Chinese colorectal cancer patients.

[Multicenter randomized control trial on safety of domestic idarubicin for acute leukemia].

OBJECTIVE: To evaluate the safety of domestically produced idarubicin in the treatment of acute leukemia by a multicenter randomized control trial. METHODS: This trial was carried out in the hemotologica department of five hospitals throughout China, with hospitalized patients who suffered from acute myelogenous leukemia ( AML except M3 type) , acute lymphocytic leukemia ( ALL) , chronic myelogenous leukemia-blast (CML-blast) , totally 155 patients. Those with severely cardial, hepatic or renal disfunction or those who had ever treated with > or = 200 mg/m(2) idarubicin were excluded from the trial. All patients signed the letter of consent as required by the Ethics Committee of our government. In this study, 155 leukemia patients were randomly grouped into: 1. test group treated using domestic idarubicin, 2. control group using imported idarubicin. The acute myelogenous leukemia regimen included idarubicin 8 mg/m(2), dl -3 plus cytosine arabinoside 100 mg/m(2), dl - 7 for 1-2 cycles. The regimen for acute lymphocytic leukemia was idarubicin 8 mg/m2, dl - 3; vincristine 2 mg/mr, dl; cyclophosphamide 750 mg/m2, dl ; plus prednisone 60 mg/m(2),dl - 14 for 1-2 cycles. RESULTS: Clinical response rate of the tested group treated with domestic idarubicin and control group treated with imported idarubicin was 78. 1% (50/64) vs. 76.9% (50/65) without any statistically significant difference between the two groups(P >0. 05). Grade Ill - IV hematological toxicity rate of the domestic idarubicin group and imported idarubicin group was 74. 0% vs. 73. 1% , respectively (P = 0. 73). Drug-related death was observed in 3 of 77 patients in the domestic idarubicin group (3.9%) due to cerebral hemorrage or septic infection. The incidence of non-hematological toxicities in domestic idarubicin group and imported idarubicin group was 84. 4% vs. 79. 5% for nausea or vomiting, 70. 1% vs. 71. 8% for infection, 42. 9% vs. 41. 0% for mucositis, 33. 8% vs. 33. 3% for alopecia, 28.6% vs. 28. 2% for serum glutamicoxalacetic transaminase abnormalitis, 16. 9% vs. 10. 3% for cardiac toxicity, all without statistically significant differences between these two groups (P > 0. 05). Discontinuation of treatment due to non-hematological toxicity was not neccessary. CONCLUSION: Domestic idarubicin is comparable to imported counterpart in efficiency and safety for the treatment of acute leukemia. The most severe side effects of domestic idarubicin is hematological toxicity, which should be closely observed and treated in time, while its non-hematological toxicity is tolerable.