Objective: To identify the phenotypes, antibodies and explore the molecular mechanisms of a patient who carries antibodies to RBC high-frequency antigens and his family members. Methods: The antibody identification test was performed for the proband by serological methods, and targeted NGS was subsequently used to detect mutations that occurred in blood group genes. Blood samples were collected from the proband and his family members. Sanger sequencing was used to verify the mutation of the XK gene. The expression of Kell blood group antigens was detected by serological methods and flow cytometry. K cells were used to detect the antibody specificity of the proband. The morphology of red blood cells was detected by the scanning electron microscopy. The serum creatine kinase levels of the proband and his family members were analyzed by colorimetric methods. Results: The results of the antibody identification test suggested that the proband might have antibodies to high-frequency antigens. NGS results suggested a homozygous mutation (c. 107G>A) in exon 1 of the XK gene in the proband, resulting in a truncated XK protein. The Sanger sequencing results of the proband were consistent with the NGS results, and the mutation was not found in other family members. The expression of Kell blood group antigens of the proband was not found by serological methods and flow cytometry. The results of the antibody specificity test showed that the proband had anti-Km antibodies. Spike-like changes were identified on red blood cells, and serum creatine kinase level was elevated in the proband. Conclusion: In this study, the McLeod phenotype caused by homozygous mutation (c. 107G>A) of XK gene was identified in Chinese individuals for the first time by the phenotype and molecular mechanism studies. The results of genotyping and phenotyping suggested that the McLeod phenotype caused by the mutation was compatible with the phenotypes of McLeod and K .

【Objective】 To explore the application of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) in the genotyping of difficult blood typing samples, and to provide evidence for clinical blood transfusion. 【Methods】 Three ambiguous blood group samples, submitted to Shanghai Blood Center by Shanghai regional hospitals, were studied, of which Sample1 included the proband and his parents. Serological methods were used to perform blood group typing, direct antibody test, unexpected antibody screening and identification test. Blood group genotyping was performed by using the MALDI-TOF MS detection systeme stablished in our laboratory. Sanger sequencing was used to confirm gene mutation sites, and serological or flow methods were used to verify specific samples′ phenotype. 【Results】 Serological results indicated the existence of antibodies against high frequency antigens in sample 1 (including proband and her mother), 2 and 3. The genotyping results of MALDI-TOF MS showed that the proband of sample 1 was Di(a+ b+ ), her father was Di(a-b+ ), her mother was Di(a+ b-), sample 2 was p, and sample 3 was Jr(a-). Sequencing results of three samples were consistent with mass spectrometry typing results. Serological results showed that sample 2 had a p phenotype. The flow cytometry results suggested that sample 3 had a Jr(a-) phenotype. 【Conclusion】 For the first time, we applied MALDI-TOF MS technology to blood type genotyping of ambiguous clinical samples in China. Compared with other genotyping methods such as PCR-SSP, MALDI-TOF MS has the advantages of rapid detection, high throughput and high specificity, which would contribute to identification of difficult blood typing samples in the future, as well as rare blood group screening.

ObjectiveTo investigate the inhibitory effect of hederasaponin B on gastric cancer HGC-27 cell and the mechanism. MethodMethyl thiazolyl tetrazolium （MTT） assay， hematoxylin-eosin （HE） staining， 4'，6-diamidino-2-phenylindote （DAPI） staining， colony formation assay， scratch assay， and flow cytometry were employed for the analysis of apoptosis and cell cycle. Thereby， the inhibitory effect of hederasaponin B on gastric cancer HGC-27 cell was investigated. Then the Pharm Mapper， UniProt， Swissdock， STRING， and Metascape were used for target screening， gene annotation， molecular docking， protein-protein interaction （PPI） network construction， Gene Ontology （GO） term and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway analysis to explore the mechanism. ResultHederasaponin B （15， 30， 60， 120 μmol·L^-1） can significantly reduce the survival rate of HGC-27 cell （P<0.01） in a time-dependent and dose-dependent manner compared with the blank group. It had no significant toxicity to normal GES-1 cell at concentration below 120 μmol·L^-1. Compared with the blank group， hederasaponin B （30， 60， 120 μmol·L^-1） induced cytoplasmic vacuolization， and nuclear deformation and karyopyknosis， inhibited the migration of HGC-27 cell （P<0.01）， and brought about the apoptosis （P<0.05， P<0.01） and cell cycle arrest of HGC-27 cell （P<0.05， P<0.01）. Hederasaponin B （10， 20， 30 μmol·L^-1） also suppressed the independent survival ability and proliferation ability of HGC-27 cell （P<0.01）. The possible action targets were kinesin-like protein KIF11， cGMP-specific 3，5 cyclic phosphodiesterase， caspase-3， serine/threonine protein kinase Chk1， proto-oncogene tyrosine protein kinase， epidermal growth factor receptor， and mitogen-activated protein kinase （MAPK） 8. The mechanism may be related to MAPK signaling pathway （pathways in cancer）， adhesion connection， focal adhesion and proteoglycans in cancer （epithelial cell signaling pathways in Helicobacter pylori infection）. ConclusionHederasaponin B exerts significant inhibitory effect on gastric cancer HGC-27 cell through multiple targets and multiple pathways.

Objective:To evaluate the effect of web-based problem-based learning software on the Clinical Medicine PBL Comprehensive Course. Methods:Thirty-eight students from the pilot class of undergraduate excellent doctors in clinical medicine were selected as the research objects. Based on the test scores of web-based problem-based learning software before the start of the course, the improvement of scores after passing the training of the Clinical Medicine PBL Comprehensive Course were compared, and the students' clinical thinking were quantitatively evaluated. Results:After all students completed the course, their abilities of expression and communication, teamwork and cooperation, problem analysis and clinical reasoning, and knowledge information management of the students increased steadily with the increase in the number of cases, but it was statistically significant after two PBL case trainings ( P<0.05). Learning intentions and attitudes scored the highest in the second PBL case (acute myocardial infarction), with statistical differences ( P<0.05). After training through the PBL course, diagnostic performance, clinical thinking, treatment scores, and overall performance scores of the students were significantly increased than before, with statistical significance ( P<0.05). The scores of case report writing and knowledge acquisition were not obviously improved. Conclusion:The combination of formative evaluation and web-based problem-based learning software can better evaluate the teaching effect and help students to understand their own shortcomings.

Objective:To explore the difficulties and measures of clinical medical postgraduates management during the national prevention of COVID-19 pandemic.Methods:This study mainly used the document review, interview and questionnaire survey methodologies, to investigate the clinical medical postgraduates school situation, online teaching, training, scientific research, psychological state during prevention of COVID-19 emergency.Results:Up to February 14, 2020, the return rate of professional degree postgraduates was 92.8% (256/276). The average score of postgraduates participating in epidemic prevention and control training was 86.59. The effect of online learning was basically the same as that of face-to-face classroom teaching. Up to March 6, 2020, the in-hospital submission rate of postgraduates’ thesis was 50.0% (65/130). Facing the pressures of COVID-19 emergency, 62.6% professional degree postgraduates (124/198) and 35.4% (70/198) academic postgraduates suffered some anxiety or depression, the difference was statistically significant ( P<0.05). Conclusions:During the COVID-19 prevention and control period, it is important to innovate work style, found the linkage system of education department-clinical department-tutor-postgraduates, pay attention to physical and mental health of postgraduates, ensure the quality of teaching, adopt various measures to do well in the education and management of clinical medical postgraduates.

Objective To explore the application value of chromosomal microarray analysis(CMA)technolo-gy in children with abnormal development at the endocrine clinic,and to summarize the data of diagnosis and treatment. Methods A retrospective analysis of 15 children with abnormal development was performed at the endocrinology clinic of Guangzhou Women and Childrenˊs Medical Center from January 2015 to December 2017. The whole genome CMA was applied according to the standard operation procedure of CytoScan 750 arrays of Affymetrix,USA. The results were analyzed by chromosome analysis suite( CHAS)software and related bioinformatics methods. Results The report on CMA showed that the genomes of 15 children had the pathogenic copy number variation(CNVs)or variants of uncer-tain significance. The chromosomal abnormalities were consistent with the clinical manifestations of all children. There were deletions in 14 cases and duplications in 3 cases. Among the 15 cases,loss of heterozygosity was found in 2 cases, uniparental disomy in 1 case,trisomy in 2 cases,Turner syndrome in 2 cases,Smith-Magenis syndrome in 1 case,and wolf Hirschhorn syndrome in 1 case. Only 2 of 15 children were diagnosed as chromosomal abnormalities by routine kar-yotype analysis. Conclusions The whole genome high resolution CMA can significantly improve the rate of diagnosis in children with abnormal development at endocrinology clinic,and is worthy of recommendation.

Objective:To adjust the wording and to examine the validity and reliability of the Chinese traditional version of the Body Image Scale (BIS) in patients with rectal cancer.Methods:Totally 180 patients pathologically diagnosed with rectal cancer were selected.The obtained data were divided equally into two parts.Half of them was for item analysis and exploratory factor analysis, and the other half was for confirmatory factor analysis and internal consistency reliability.The criterion validity was tested with the Quality of Life Questionnare-Core30 (QLQ-C30).Twenty-five patients were retested for test-retest reliability with 2 week interval.Results:Two factors were retained after exploratory factor analysis, which could explain 69.1％ of the total variation.And the result of confirmatory factor analysis was that the structure of the scale was stable and achieved goodness of fit (χ2/df=2.32, CFI=0.96, NFI=0.93, IFI=0.96, TLI=0.94, RMSEA=0.078).The scores of total scale and two factors were negatively correlated with the scores of five function domains and overall quality of life of QLQ-C30 (r=-0.27——0.54, Ps＜0.05).In total scale, Cronbach' s α coefficient of total scale was 0.92, while test-retest reliability was 0.88.Conclusion:The Chinese version of BIS showed good validity and reliability for assessment of body image in Chinese patients with rectal cancer.

Objective The purpose of this study was to evaluate the degree of skin thickening of patients with systemic sclerosis (SSc) by high-frequecy ultrasound,as well as the value of ultrasound.Methods Thirty-one patients with SSc and 31 age-matched and sex-matched healthy control subjects were enrolled.Skin thickness,modified Rodnan skin score (mRss),disease activity index (DA1) and other clinical parameters within and between groups were compared using SPSS 21 software.Student's t test,x2 test or nonparametric testing was performed to compare between groups.The Pearson or Spearman methods were used to test correlation.Sensitivity and specificity of skin thickness detection by high-frequecy ultrasound were evaluated by using receiver operating characteristic (ROC) curve analysis.Results Total thickness of skin (TST) of patientswith SSc were positively correlated to the total mRss (r=0.416,P=0.020) and DAI (r=0.436,P=0.014).The skin thickness of patients with mRss 0,1,2 was higher than CNT [1.45(0.60),1.70(0.30) mm,1.60 (0.30) mm vs 1.30 (0.35) mm,Z=-3.242,-6.577,-5.090,P＜0.01].The cut-off value of TST used as the evaluation of skin change was 7.4 mm by ROC curve analysis,and the sensitivity and specificity of them was 77.40％ and 87.10％ respectively,and patients with thickened skin were more likely to suffer interstitial lung disease (ILD) (16 vs 1,x2=26.004,P=0.014),higher mRss [10(6) vs 4(5),Z=-2.499,P=0.031],DAI [(5.2±2.4) vs (2.3±1.7),t=-3.104,P＜0.01)] and CRP [(8.60 (10.48) mg/L vs 3.52 (4.93) mg/L,Z=-2.276,P=0.038].Conclusion US combined with mRss are helpful to evaluate the changes of skin and disease activity of patients in SSc.US can identify the early and subclinical skin involvement that may precede mRss,providing a more reliable tool for diagnosis,treat efficacy and prediction of organ damage.

Objective To explore how leptin affects RA,especially those with joint erosion.Methods The study recruited 48 consecutive patients with RA (14 patients with knee joint effusion) and 23 age and sex matched healthy people.RA patients were grouped into low and moderate activity group [2.6＜28-joint disease activity score (DAS28) ≤5.1,n =5] and high activity group (DAS28 ＞5.1,n =43) according DAS28-ESR;Meanwhile,they were grouped into bone erosive group (n=20) and non-erosive group (n=28) according to X-ray of both hands.Demographic data of RA patients were recorded.ELISA was applied to assess leptin and a disintegrin and metalloproteinase with thrombospondin-like motifs (ADAMTS4) in serum and synovial fluid of RA group.Sharp/van der Heijde scores were used to assess bone erosion and joint space narrowing.Leptin and ADAMTS4 from serum and synovial fluid were compared between different groups using t test,Rank sum test,Chi-square test and Analysis of Variance,and we did Pearson and Spearman's Corre-lation analyses between these values and clinical features,lab indicators and radiological scores.Moreover,we did single factor and logistic regression analyses,which facilitated screening risk factors of joint destruction.Results Serum leptin in RA group was significantly higher than that of the control group [8.06(6.24) ng/ml vs 4.62(7.13),Z=-2.113,P=0.035],and leptin was positively correlated with Shar/van der Heijde score (r=0.347,P=0.016).Serum leptin in erosive RA patients was higher than that of the non-erosive patients (Z=-2.070,P=0.038),and there was a positive correlation between leptin and ADAMTS4 only in synovial fluid of RA patients with erosion (r=0.900,P=0.037).It was found in logistic regression results that RA patients with more tender joint counts and elevated leptin were more likely to develop bone erosion [OR=1.229,95％CI (1.007,1.500),P=0.043;OR=1.159,95％CI (1.015,1.324),P=0.030].Conclusion Leptin participates RA joint destruction probably by modulating expression of ADAMTS4.Leptin and tender joint count are independent risk factors for RA with joint destruction.

OBJECTIVETo investigate the association of parameters in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using reference region model with prognostic factors and molecular subtypes of breast cancer.

METHODSMRI and pathological data of 50 patients with pathologically confirmed invasive ductal carcinoma of the breast were retrospectively analyzed. Reference region model was applied to analyze pharmacokinetic quantitative parameters including volume transfer constant (RR K), rate constant (K) and the ratio of Kto extracellular space volume (K/V). The associations of the above parameters with prognostic factors and molecular subtypes of breast cancer were analyzed.

RESULTSRR Kand Kwere significantly higher in patients of histological grade 3 compared with those of histological grade 1 & 2 (all<0.05); and the patients with estrogen receptor (ER)-negative and/or progesterone receptor (PR)-negative also had higher RR Kand Kthan those with ER-positive or PR-positive (all<0.05). For immunohistochemistry, RR Kand Kwere significantly higher in triple negative breast cancer compared with luminal type breast cancer (all<0.05).

CONCLUSIONSHigh RR Kand Kare associated with poor prognosis of breast cancer, and which can also be used to distinguish molecular subtypes of breast cancer.