Objective:To investigate the molecular epidemiological characteristics of norovirus (NoV) in hospitalized children with sporadic acute gastroenteritis in Tianjin in 2019.Methods:Fecal specimens and clinical data were collected from 3 116 hospitalized children with sporadic acute gastroenteritis possibly caused by viral infection in Tianjin Children′ Hospital between January and December, 2019. Real-time quantitative PCR was used to detect NoV. Partial sequences of RNA-dependent RNA polymerase (RdRp) and capsid genes of NoV were amplified by RT-PCR. Sequence alignment and phylogenetic analysis were performed for further analysis.Results:Among the 3 116 specimens, 809 (26.0%) were positive for NoV. There were significant differences in NoV detection rate between different age groups ( P=0.000), and the highest NoV detection rate (31.6%) was observed in the age group of 7-12 months. Moreover, the detection rate of NoV varied with seasons ( P=0.000), and the NoV detection rate was highest in winter (39.0%). Based on the sequence analysis of RdRp and capsid genes, 286 identified NoV strains belonged to six genotypes, which were GⅡ.P12-GⅡ.3, GⅡ.P16-GⅡ.2, GⅡ.P17-GⅡ.17, GⅡ.Pe-GⅡ.2, GⅡ.Pe-GⅡ.3 and GⅡ.Pe-GⅡ.4. The predominant genotype was GⅡ.Pe-GⅡ.4 Sydney 2012 (61.2%), followed by GⅡ.P12-GⅡ.3 (33.6%, 96/286), GⅡ.Pe-GⅡ.3 (2.4%, 7/286), GⅡ.P16-GⅡ.2 (2.1%, 6/286), GⅡ.Pe-GⅡ.2 (0.3%, 1/286) and GⅡ.P17-GⅡ.17 (0.3%, 1/286). Patients carrying the NoV of GⅡ.Pe-GⅡ.4 Sydney 2012 genotype were likely to suffer from vomiting than those positive for NoV of GⅡ.P12-GⅡ.3 genotype. Conclusions:NoV was an important pathogen causing acute gastroenteritis in children. GⅡ.Pe-GⅡ.4 Sydney 2012 and GⅡ.P12-GⅡ.3 were the major genotypes of NoV in hospitalized children with sporadic acute gastroenteritis in Tianjin in 2019.

Objective:To evaluate the prevalence of human rhinovirus (HRV) infection in hospitalized children in Tianjin and investigate the clinical impact of HRV infections.Methods:From July 2017 to December 2019, 2 945 nasopharyngeal secretion specimens were screened for HRV using polymerase chain reaction (PCR). VP4/VP2 sequences of HRV were further characterized. The clinical characteristics of the HRV infection were analyzed. The detection results of HRV for different groups and different months were compared using SPSS 19.0.Results:HRV-positive specimens accounted for 8.15% (240/2 945), of which 74.78% (86/115) were diagnosed with pneumonia, 40.83%(98/240) had co-infections with other common pathogens. HRV infections could be detected throughout the year with peaks in spring (11.00%, 66/660) and autumn (9.29%, 81/872). The positive rate of HRV was 4.14%(29/700) in winter. By VP4/VP2 sequence analysis, HRV-A was the most frequently detected strain(50.00%, 78/156), followed by HRV-C (41.67%, 65/156).46.15% (30/65) of HRV-C infections occurred in October and November. There were several different HRV-A types and HRV-C types. The most commonly detected HRV-A types were A12(11.54%, 9/78), A49(6.41%, 5/78), A22, A101, and A66(5.13%, 4/78), etc. The most common HRV-C types were C2(20.00%, 13/65), C22(9.23%, 6/65), C26, C43, C54 and C53(4.62%,3/65). Patients with HRV-A infections are more likely to show fever symptoms than HRV-C (χ2=5.411, P<0.05). No significant difference in other symptoms were found between the two types. Conclusions:HRV was a commonly detected virus among infants and had a clear seasonal distribution. It′s also possible for the HRV patients to have co-infections with other pathogens.HRV showed high genetic diversity.

Objective To evaluate left ventricular(LV) twist and untwist using velocity vector imaging(VVI) in patients with apical hypertrophic cardiomyopathy (ApHCM). Methods Twenty-three patients diagnosed with ApHCM were consecutively enrolled and compared with normal controls. After a standard echocardiographic examination, parasternal basal and apical short-axis planes were scanned to quantify LV rotations,twist and LV untwist using VVI. Results Compared with the normal controls, the rotation and rotaional velocity of apical subendocardial myocardium were markedly decreased in ApHCM patients during the period of systole ( P＜0.05) ,but the decreases in basal planes were not significant. As a consequence,LV twist was significantly lower in ApHCM patients (P＜ 0.05). Compared to normal controls,the velocity of LV untwisting was also significantly decreased in ApHCM patients ( P＜0.05).Conclusions The twist and untwist of LV subendocardial myocardium were decreased in ApHCM patients.VVI is a useful method to assess the characteristics of LV twist and untwist in ApHCM patients.

Objective To evaluate the clinical effect of the facial soft tissue defect treated with platelet-rich plasma (PRP) mixed with purified fat.Methods 35 patients with facial soft-tissue defects were treated by PRP mixed with centrifuged fat tissue.Using Fuzzy judgment method the clinical effectiveness of therapeutic outcomes were evaluated on fullness,injection of frequency and satisfaction during 3 to 6 months of follow-up.Results The therapeutic outcomes showed that the reconstructed face became a relative symmetrical and natural appearance with not evidently fat resorption and stable after operation.Both patients and surgeons were satisfied with the results.The score of effectiveness was highest in Fuzzy judgment.Conclusions The efficacy of PRP is significant in enhancing fat graft,reducing fat necrosis and resorption.The fat tissue mixed with PRP is a reliable reconstruction option for the facial soft tissue defect.

Objective:To investigate the prevalence and clinical characteristics of Mycoplasma pneumoniae( Mp) genotypes and subtypes in children in Tianjin. Methods:Children with pneumonia admitted to Tianjin Children′s Hospital from December 2017 to December 2019 were selected as the research objects. Bronchoalveolar lavage fluid was collected by fiberoptic bronchoscopy. The positive samples were detected by real-time fluorescent quantitative PCR and Mp culture. PCR-restriction fragment length polymorphism(RFLP) and multiple variable number tandem repeats were used for genotyping. Detailed clinical and laboratory data were collected for all cases. Results:The results of RFLP showed that there were 138 cases (78.9%) of typeⅠand 37 cases (21.1%) of type Ⅱ; 37 cases of type M3-5-6-2, including six subtypes B, G, M, S, V and Y; 138 cases of M4-5-7-2 were detected, including seven subtypes of E, J, P, U, X, Z and a. In M3-5-6-2 type, there were 1 case of P1-Ⅰtype (2.7%), 36 cases of P1-Ⅱtype (97.3%), 137 cases of P1-Ⅰ type (99.2%) and 1 case of P1-Ⅱ type (0.7%) in M4-5-7-2 type. There was no significant difference in genotype distribution among different age groups. There were statistical differences in the distribution of four seasons among the 13 genotypes of B, G, M, S, V, Y and E, J, P, U, X, Z, a. All Mp infected children had symptoms of fever and cough. The hospitalization time, fever duration, high fever (>39℃), cough duration, skin changes, digestive system symptoms and liver function injury rate of P1-Ⅰ/M4-5-7-2 pneumonia children were higher than those of P1-Ⅱ/M3-5-6-2 pneumonia children, but the difference was not statistically significant. The WBC count of P1-Ⅱ/M3-5-6-2 types was higher than that of typeⅠand M4-5-7-2; the LDH of P1-Ⅰ/M4-5-7-2 was higher than that of Ⅱ and M3-5-6-2, with statistical difference. There was no significant difference in the incidence of inflammatory consolidation, atelectasis, pleural thickening and pleural effusion among different genotypes. Conclusions:Mp infection in children with pneumonia in Tianjin is mainly P1-Ⅰ/ M4-5-7-2, and P1-Ⅱ is on the rise. P1-Ⅰ and M4-5-7-2 were associated with fever and severe symptoms.

In view of the problems existing in current medical laboratory safety training, such as overly broad goals, a lack of diverse instructional methodologies, a disconnection between the content and the actual needs of students, and a "one-size-fits-all" assessment method, the outcome-based education (OBE) was applied to laboratory safety training. Reform and practice were carried out on four aspects: training objectives, methods, content, and assessment. The training program was constructed with the objectives of addressing the safety competency requirements for students entering the laboratory and enhancing their safety skills. The training method highlighted the dominant role of students, shifted from a unidimensional to a multidimensional approach, and increased student engagement. The training content was continuously updated and refined to align closely with the specific safety requirements of students conducting experiments. The whole process assessment method of formative evaluation was employed. The training effects were evaluated from course scores, competition performance, and questionnaire for satisfaction. The results indicate that, compared with traditional training methods, the OBE was more effective in focusing on training objectives and fostering student interest of learning. Although there was no significant difference in scores on foundational knowledge examinations, the OBE significantly enhanced student participation and strengthened their sense of belonging. The questionnaire survey showed that 94.22% (163/173) of the participants provided positive feedback regarding the OBE. Among these respondents, 68.21% (118/173) thought that the interactive teaching of case studies was more acceptable and 98.48% (65/66) praised the practical training, believing that it was more effective than traditional training to improve safety skills. Thus, the OBE can optimize safety education and training, improve students' safety competencies in multiple dimensions, and lay a solid foundation for subsequent laboratory learning and work.

Apolipoprotein H(APOH)is a glycoprotein synthesized by liver cells,closely related to insulin resistance(IR)and lipoprotein metabolism,and plays an important role in the occurrence and development of diabetes mellitus and dyslipidemia.This article reviews the research progress on the biological functions of APOH and its correlation with metabolic diseases.

Objective:To understand the pathogen infection and epidemiological characteristics of children with diarrhea in Tianjin.Methods:Stool samples from 1 466 children with diarrhea in Tianjin Children's Hospital from August 2017 to July 2018 were collected, and all samples were tested for five intestinal-related pathogens (norovirus, rotavirus, Clostridium difficile toxin, adenovirus, and astrovirus). Results:Among the 1 466 samples, 627 samples were positive for nucleic acid detection of intestinal pathogens, with a positive rate of 42.8%. The detection rate of norovirus was the highest (26.3%), followed by rotavirus (15.3%), Clostridium difficile toxin (4.6%), adenovirus (4.1%), and astrovirus (1.84%). The infection has obvious seasonality. The positive detection rates of the five pathogens were similar among children of different sexes, and only the positive detection rates of norovirus and rotavirus were statistically significant among different ages ( P<0.05). There were 110 cases of mixed infection, and the mixed infection of norovirus and rotavirus was the most common, with a total of 37 cases. Conclusions:The pathogen spectrum of infant infectious diarrhea in Tianjin is complex and diverse, and the main pathogens are norovirus and rotavirus.

Objective:To explore the effect of self-made dynamic cardiovascular three-dimensional model combined with CBL (case-based learning) teaching method in the clerkship of valvular heart disease for medical students.Methods:Sixty five-year clinical medical undergraduates from Nanjing Medical University (Batch 2016) were randomly divided into experimental group and control group. The experimental group received dynamic cardiovascular 3D model combined with CBL teaching method, while the control group received traditional model combined with CBL teaching method. After the course, the teaching effect was evaluated by examination and questionnaire. SPSS 19.0 was used for independent sample t test and chi-square test. Results:Compared with the control group, the students in experimental group had higher scores of basic theoretical knowledge [(43.10±3.51) vs. (40.87±3.19)] and clinical thinking ability [(42.20±3.15) vs. (40.20±3.81)], with significant differences ( P<0.05). Furthermore, they showed higher evaluation and satisfaction to learning initiative and enthusiasm, mastery of theoretical knowledge, clinical thinking ability, classroom learning interest, classroom activity and clarity of knowledge teaching, with significant differences ( P<0.05). Conclusion:In the teaching of valvular heart disease clerkship, the application of self-made dynamic cardiovascular three-dimensional model combined with CBL teaching method, can cultivate students' clinical diagnostic thinking ability and improve teaching quality.

Objective To observe the therapeutic effect of laparoscopic sleeve gastrectomy(LSG)in treating patients with obesity and polycystic ovary syndrome(PC OS).Methods In this ret-rospective analysis,clinical materials of 60 patients with obesity and PCOS by LSG were analyzed,and postoperative improvements of PCOS symptoms were observed.Results A total of 60 patients had a pre-operative mean body mass index(BMI)of(39.4±5.4)kg/m2 and an average age of(26.3±6.1)years old,and all of them successfully completed LSG.After follow-up of 12 to 18 months,50 cases(83.3％)had normalized menstrual cycles,with an average recovery time of(4.5±2.2)months af-ter surgery,and 7 cases had natural pregnancy after surgery.Before surgery,ultrasound results in 35 patients indicated polycystic ovarian morphology(PCOM),and 29 cases(82.9％)regained normal o-varian status with an average recovery duration of(6.3±2.8)months.Complicated hyperandrogene-mia was observed in 31 patients,and 29 cases(93.5％)exhibited normalization of testosterone levels within 18 months after surgery.At 18 months after surgery,the BMI was(26.47±4.70)kg/m2,the average weight loss was(32.4±7.4)％.Conclusion LSG is a safe and effective treatment for obese PCOS.