It is difficult to accurately distinguish pharyngitis caused by Group A Streptococcus(GAS) from other pathogens according to the clinical presentation alone, which cannot effectively guide the rational use of antimicrobials.The pharyngeal swab culture, rapid antigen detection test, nucleic acid test, and blood test can help definitively diagnose GAS pharyngitis.However, there are differences in different guidelines on who the laboratory test methods are intended for, interpretation of laboratory test results and so on.This article summarizes and analyses the laboratory diagnostic modalities and their characteristics, as well as recommendations for GAS pharyngitis in different guidelines to provide references for the clinical diagnosis, antimicrobial treatment, and further study of GAS pharyngitis.

Objective:To solve international students' problems of learning difficulties and passive learning caused by language barriers in the process of biochemistry learning from the perspective of teachers in this specialty.Methods:Eighty international students were randomly divided into experimental group and control group. In the experimental group, the regional management mode was introduced in teaching, allowing students to speak mother tongues or English for group discussions on well-designed questions, and at the same time, classroom quizzes and stage tests were given, introducing formative evaluation to supervise students' learning and assess their learning performance. The control group received conventional teaching. The learning effects were assessed through a final exam and questionnaire survey. SPSS 25.0 was used to perform the Kruskal-Wallis H test and Nemenyi test. Results:Twenty-seven (75.00%) students believed that group discussion by region could deepen the discussion of questions; 27 (75.00%) no longer felt difficult, or even felt easy, to learn biochemistry; and nearly 90.00% of the students affirmed the formative evaluation mode, believing that it had positive effects on their learning attitude and behavior. In addition, the median exam score of the experimental group was 36.94% higher than that of the control class in the same year.Conclusions:Regional management combined with formative evaluation can promote international students' learning enthusiasm, improve their comprehensive achievement, and positively affect their learning behavior.

Objective:To analyse the clinical presentation and pathogenic gene mutations of a family diagnosed with primary familial brain calcification (PFBC).Methods:A pedigree with primary familial brain calcification was recruited. The clinical data of the proband who was admitted to the Affiliated Hospital of Guizhou Medical University in March 2020 and the family members were collected. The DNA sequence of myogenesis regulating glycosidase (MYORG) gene was detected by Sanger sequencing in the proband and some available family members.Results:The proband is a male, 30 years old. There was only one patient of PFBC in this family. The first symptom of the proband was vagueness of speech, and gradually extrapyramidal symptoms such as slow and flexible movement and advanced cognitive impairment appeared. The brain CT of the proband and his second brother showed extensive symmetrical calcifications, mainly located in the bilateral cerebellar hemispheres, basal ganglia and thalamus. A homozygous mutation in the exon 2 of the MYORG gene [c.1967T>C(p.I656T)] was identified in the proband and an asymptomatic patient. The heterozygous mutation of MYORG gene was also detected in four healthy family members.Conclusions:All patients with homozygous mutations of MYORG gene showed calcification in CT scan, and most of the lesions were located in basal ganglia, cerebellum, subcortical white matter and thalamus. Compared with the patients with autosomal dominant gene mutation, the patients with MYORG gene mutation had more extensive intracranial calcification lesions, and the pontocerebellar lesions were more common. The most common symptoms of MYORG gene mutation patients were dyskinesia, mainly tremor paralysis and unclear speech.

Objective:To observe the ultrasonographic features of cervical lymph node metastasis and analyze their relationship with the expression of cell proliferation-associated nuclear antigen (Ki-67).Methods:The clinical data of 92 patients with cervical lymph node metastasis who received treatment in Zhejiang Quhua Hospital, China between June 2017 and July 2019 were retrospectively analyzed. The correlation between ultrasonographic features of cervical lymph node metastasis and Ki-67 expression was analyzed.Results:Among the 92 patients, 158 metastatic lymph nodes were confirmed by pathological examination. The main ultrasonic imaging features were the length ratio of long diameter to short diameter < 2 in 119 (75.32%) lymph nodes, disappearance of portal hyperechoic signal in 127 (80.38%) lymph nodes, punctate hyperechoic signal in 108 (68.35%) lymph nodes, cystic degeneration in 57 (36.08%) lymph nodes, mixed types of peripheral blood flow signal in 124 (78.48%) lymph nodes, microcalcification in 123 (77.85%) lymph nodes. The length ratio of long diameter to short diameter < 2, punctate hyperechoic signal and mixed types of peripheral blood flow signal were correlated with high expression of Ki-67 ( χ2 = 24.252, 15.732, 17.033, all P < 0.05). Conclusion:High expression of Ki-67 is correlated with the length ratio of long diameter to short diameter < 2, punctate hyperechoic signal and mixed types of peripheral blood flow signal in cervical lymph node metastasis.

Objective:To investigate the effects of pre-B lymphocytic leukemia transcription factor (PBX1) expression on the apoptosis, reactive oxygen species (ROS) content and transcriptional activation factor 3 (STAT3) signaling pathway of lung cancer cells.Methods:Real-time quantitative polymerase chain reaction was used to detect the expression level of PBX1 in lung cancer tissues and adjacent tissues. The correlation between PBX1 expression level and clinical pathological parameters of patients were analyzed. Western blot was used to detect the protein expression level of PBX1 in human lung cancer cell lines, including A549, SPC-A1, SK-MES-1 and H1299. A549 cells were transfected with blank control (blank group), negative control (NC group) or PBX1 small interfering RNA (siRNA group), respectively. The cells apoptosis and ROS content were detected by flow cytometry. The protein expression levels of PBX1, STAT3, phosphorylated STAT3 (p-STAT3), B cell lymphoma/leukemia-2 (Bcl-2) and survivin in each group were detected by western blot.Results:The expression level of PBX1 mRNA in lung cancer was (2.36±0.23), significantly higher than (1.02±0.15) in paracancerous tissues ( P<0.05). The expression level of PBX1 was correlated with lung cancer differentiation, lymph node metastasis and TNM stage ( P<0.05). The expression levels of PBX1 in human lung cancer cells A549, SPC-A1, SK-MES-1 and H1299 were (0.454±0.038), (0.403±0.034), (0.311±0.028) and (0.377±0.035), respectively, significantly higher than (0.041±0.007) of human normal lung cells MRC-5 ( P<0.05). The expression level of PBX1 protein in A549 cells transfected with PBX1 siRNA was (0.082±0.010), significantly lower than (0.704±0.065) of the blank group ( P<0.05). The apoptosis rate and ROS content of siPBX1 group were (30.78±3.64)% and (51.55±5.03), respectively, significantly higher than (3.92±0.27)% and (22.36±1.31) of blank group ( P<0.05). The protein expressions of p-STAT3, Bcl-2 and survivin were (0.051±0.006), (0.202±0.018) and (0.068±0.008), respectively, significantly lower than (0.172±0.010), (0.425±0.041) and (0.196±0.021) of blank group ( P<0.05). Conclusion:Inhibition of PBX1 expression can induce the apoptosis of lung cancer cell, the mechanism may be related to ROS production and down-regulation of STAT3 signal.

Objective:To investigate the effects of pre-B lymphocytic leukemia transcription factor (PBX1) expression on the apoptosis, reactive oxygen species (ROS) content and transcriptional activation factor 3 (STAT3) signaling pathway of lung cancer cells.Methods:Real-time quantitative polymerase chain reaction was used to detect the expression level of PBX1 in lung cancer tissues and adjacent tissues. The correlation between PBX1 expression level and clinical pathological parameters of patients were analyzed. Western blot was used to detect the protein expression level of PBX1 in human lung cancer cell lines, including A549, SPC-A1, SK-MES-1 and H1299. A549 cells were transfected with blank control (blank group), negative control (NC group) or PBX1 small interfering RNA (siRNA group), respectively. The cells apoptosis and ROS content were detected by flow cytometry. The protein expression levels of PBX1, STAT3, phosphorylated STAT3 (p-STAT3), B cell lymphoma/leukemia-2 (Bcl-2) and survivin in each group were detected by western blot.Results:The expression level of PBX1 mRNA in lung cancer was (2.36±0.23), significantly higher than (1.02±0.15) in paracancerous tissues ( P<0.05). The expression level of PBX1 was correlated with lung cancer differentiation, lymph node metastasis and TNM stage ( P<0.05). The expression levels of PBX1 in human lung cancer cells A549, SPC-A1, SK-MES-1 and H1299 were (0.454±0.038), (0.403±0.034), (0.311±0.028) and (0.377±0.035), respectively, significantly higher than (0.041±0.007) of human normal lung cells MRC-5 ( P<0.05). The expression level of PBX1 protein in A549 cells transfected with PBX1 siRNA was (0.082±0.010), significantly lower than (0.704±0.065) of the blank group ( P<0.05). The apoptosis rate and ROS content of siPBX1 group were (30.78±3.64)% and (51.55±5.03), respectively, significantly higher than (3.92±0.27)% and (22.36±1.31) of blank group ( P<0.05). The protein expressions of p-STAT3, Bcl-2 and survivin were (0.051±0.006), (0.202±0.018) and (0.068±0.008), respectively, significantly lower than (0.172±0.010), (0.425±0.041) and (0.196±0.021) of blank group ( P<0.05). Conclusion:Inhibition of PBX1 expression can induce the apoptosis of lung cancer cell, the mechanism may be related to ROS production and down-regulation of STAT3 signal.

Objective To study the correlation between laryngopharyngeal reflux (LPR) and secretory otitis media (SOM).Methods A total of 294 adult patients with reflux-related symptoms were recruited in this study.The patients were evaluated with reflux symptom index (RSI) and reflux finding score (RFS).Tympanometry was conducted to all the patients.The 54 patients with the otitis media effusion with type B tympanograms were tested by auripuncture.Results Among the 294 patients,168 cases showed RSI＜13,in which 128 cases,31 cases and 9 cases had type A,type C,and type B tympanograms,respectively.The other 126 patients showed RSI＞13 in which 52 cases,29 cases and 45 cases had type A,type C,and type B tympanograms,respectively.Among the 294 patiems,172 patients showed RFS＜7,in which 131,32 and 9 cases had type A,type C,and type B tympanograms,respectively.The left 122 patients showed RFS＞7,in which 49,28 and 45 cases had type A,type C,and type B tympanograms,respectively.The ratio of type B tympanograms in the patients with RSI＞13 and RFS＞7 were both significantly higher than those in the patients with RSI＜13 and RFS＜7 (P＜0.05).The RSI scores of patients with type A,C,and B tympanogram were 8.6± 3.8,15.9±7.5,and 23.9±8.6,respectively,and the RFS score were 5.6±2.6,9.6±4.7,and 15.3±6.6,respectively.Compared with type A and C,the patients with type B tympanogram had significantly higher RSI and RFS score (P＜ 0.05).Among the 54 patients of type B tympanograms,those with RSI＜13 were found to have serous fluid,grume fluid,glue fluid as in 6 cases,2 cases,and 1 case,while the patient of the RSI＞ 13 had serous fluid,grume fluid,glue fluid in 13 cases,23 cases,and 9 cases,respectively.The otitis media effusion of the patients with the RSI＜13 were mainly serous,while those with the RSI＞13 were mainly sticky.Conclusion The correlation between LPR and SOM was significant.LPRmay accelerate the progress of SOM.

The "student-centered" concept highlights the dominant position of students in the teaching process and makes up for the deficiency of traditional teaching mode.Based on the above idea,the teaching team of the author's department tried to improve teaching effect through effective teaching design in biochemistry.Firstly,the teaching goal (the goal of knowledge,ability and emotion) and the important situational factors the learning situation analysis,the characteristics of the course and the class,etc)should be identified.suitable teaching strategies he inspiration strategy,exploration strategy and problem solution strategy,etc.),teaching method (discussion,case study,problem based learning,etc.) and proper assessment (such as the summative assessment with formative evaluation) should be determined to organize classroom teaching.At the end of the class the timely feedback and the teaching reflection should be carried outto extend classroom teaching to extra-curricular class.The results showed that effective teaching designismore likely to stimulate students' learning enthusiasm,promote students' deep learning and achieve better teaching effects.

Objective: To investigate the history, risk factors for prognosis of malignant biliary stricture (MBS) patients receiving conservative therapy after endoscopic retrograde cholangiopancreatography(ERCP) and to set up a predictive model for overall survival (OS). Methods: MBS patients who underwent ERCP and conservative therapy in Xijing Hospital and PLA No.451 Hospital from January 2009 to December 2013 were enrolled to the present study. Predictive factors associated with OS were identified in the training cohort by stepwise multivariate Cox regression analysis. A predictive model was then developed and externally validated in the validation cohort. Results: Between January 2009 and December 2013, 152 and 149 patients were eligible to the training and validation cohort respectively. In the training cohort, tumors were mainly originated from bile duct (33.6%), pancreas (23.5%) or ampulla (20.4%). 76.3% (116/152) patients died during the observation period. The median OS for the training population was 5.0 months (3.9-6.2 months). CA19-9≥1 000 U/mL, non-ampulla tumor, metastasis, pre-ERCP total bilirubin≥7 mg/dL and hilar stricture were identified as independent predictive factors of poor OS (all P<0.05). Based on these factors, the COMTH predictive model was developed. The median OS of patients with COMTH>8 in the training and validation cohorts were both 3.0 months, which were significantly shorter than those with COMTH≤8 (10.0 and 6.9 months in the training and validation cohorts respectively, both P<0.001). Conclusion The prognosis of MBS patients undergoing ERCP is poor. The survival chance of patients with COMTH>8 is even more dismal.

Objective To analyze the characteristic of auditory brainstem responses (ABR) evoked by chirp in normal hearing subjects .Methods Fifteen cases (30 ears) with normal hearing young people were recorded ABR by stimulation with two kinds of sounds :chirp and click .The data were compared .Results The response threshold of chirp-ABR were lower than that of click -ABR .The average difference was 8 .59 dB .At 90 dB nHL ,the wave V amplitude yield no significant difference between chirp -ABR and click-ABR .The wave V amplitude had a signifi-cant difference between chirp -ABR and click-ABR at 60 dB nHL .At 90 and 60 dB nHL ,the wave V amplitude of chirp-ABR had not a significant difference .The occurence rate was 40% for the wave I of chirp -ABR ,obvi-ously less than that of click -ABR .At 90 dB nHL ,the wave V latency of chirp -ABR was shorter than that of click-ABR .Conclusion The wave V response threshold of chirp -ABR is less than that of the click -ABR .The chirp-ABR is more advantageous than the click -ABR for assessing hearing threshold .