Objective:To investigate the current situation of junior medical students'cognition on the relationship between doctors and patients,and to provide reference for medical students'medical education and medical education reform,Methods:Self-made questionnaire was adopted to investigate the cognitive status of doctor-patient relationship among junior medical students from three medical universities in Guangzhou.Results:Totally 41.04％ of junior medical students had a basic understanding of doctor-patient relationship,and the degree of understanding of doctor-patient relationship is not different between junior and senior medical students (P ＞ 0.05);76.62％ of medical students got acquainted with the status of doctor-patient relationship mainly through the media;86.57％ of junior medical students thought that the doctor-patient relationship was tense.The cognition of doctor-patient relationship between male and female students was similar (P ＞ 0.05),and so wasit between freshmen and sophomores (P ＞ 0.05).Male and female students had the same opinion on the future trend of doctor-patient relationship (P ＞ 0.05).Many junior medical students were optimistic about the future doctor-patient relationship.Compared with freshmen,sophomore medical students were less optimistic about the future doctor-patient relationship (P ＜ 0.05).Medical students mostly agreed on the causes of medical disputes (P ＞ 0.05),believing that the main reason was the medical system.Conclusions:The cognition of the doctor-patient relationship profoundly affects the junior medical students as well as their choices of future employment and communication styles between patients and them,which may have important significance for avoiding medical disputes.Society,schools and the media should actively create a good atmosphere for the doctor-patient relationship.

OBJECTIVE: Adopting methods of cell culture to explore the effects and mechanisms of Jianpi Bushen Huoxue Prescription (JPBSHXP), a traditional Chinese compound herbal medicine for strengthening spleen, reinforcing kidney and activating blood circulation, in inhibiting hematopoietic cells apoptosis in a mouse model of aplastic anemia (AA). METHODS: Blood serum of AA mice was made from an AA mouse model. Blood serums containing different traditional Chinese compound herbal medicine were made from rats after intragastric administration of JPBSHXP and its related decoctions, respectively. Bone marrow cells of normal mice were incubated by these blood serums for 24 hours, respectively. The apoptosis of the bone marrow cells were assayed by flow cytometry and transmission electron microscopy (TEM). RESULTS: It was indicated that the bone marrow cells of normal mice incubated with blood serum of AA mice displayed typical apoptosis. The apoptosis rates of bone marrow cells of the AA mice incubated by blood serum containing different traditional Chinese herbal medicine were decreased. The effect of Bushen (reinforcing kidey) Recipe was better than Jianpi (strengthening spleen) Recipe and Huoxue (activating blood circulation) Recipe, while the effect of JPBSHXP was the best. TEM results showed that the effect of Bushen Recipe was better than that of the Jianpi Recipe and the Huoxue Recipe, while the effect of JPBSHXP was the best. CONCLUSION: JPBSHXP and its related decoctions can significantly decrease the apoptosis rate of bone marrow mononuclear cells of the AA mice. It is inferred that JPBSHXP can promote bone marrow hematogenesis.

Human ribosomal DNA (hrDNA) targeting vector pHr is a homologous recombinant plasmid for human genome which developed in the State Key Laboratory of Medical Genetics. pHr was used to construct a recombinant plasmid pHr-CMG expressing mda-7/GFP fusion gene and its efficacy in the hepatocellular carcinoma cell line Bel-7402 was investigated. The expression of mda-7/GFP fusion gene was detected by fluorescent microscope, RT-PCR and Western blotting, and its function was detected by cell-cycle analyses, MTT assay and Hoechst33258 staining. The results demonstrated that pHr-CMG vector could express MDA-7/GFP fusion protein effectually and the mda-7 gene could induce cell apoptosis and proliferation suppression in Bel-7402 cell line, which might be caused by the G2/M cell cycle arrest. These results also suggested that human ribosomal DNA targeting vector system and the pHr-CMG vector may be applied in further gene therapy researches for hepatocellular carcinoma.

In order to study the tumor suppression effect of p53 with CMV enhancer and hTERT promoter mediated by human-derived vector pHrn in liver cancer cell Bel-7402, report plasmid pchEGFP, tumor suppressor plasmids pchp53Arg and pchp53Pro were constructed by inserting expression cassette CMVe+hTERTp+EGFP, CMVe+hTERTp+p53Arg and CMVe+hTERTp+p53Pro into pHrn respectively. 24 h after cell transfection by lipofectamine 2000, GFP expression pattern was analyzed through fluorescence microscope and flow cytometry; RT-PCR and Western blot were taken to study the p53 expression pattern. The cell apoptosis by Hoechst 33258 and Annexin V-FITC/PI staining was also studied. Results show that the expression of GFP and p53 protein in Bel-7402were detected, but apparent cell apoptosis could not be found. The recombinant p53 mediated by human-derived vector could express in Bel-7402, but no significant tumor suppression effect was detected, which might result from the down regulation effect of the wild type p53 on hTERT promoter.

OBJECTIVETo search for the dystrophin gene mutations of Duchenne muscular dystrophy (DMD) patients without gross deletions, in order to offer accurate genetic counseling and prenatal diagnosis for those families.

METHODSAll 79 exons of the dystrophin gene as well as its 5'-UTR and 3'-UTR of 14 Chinese DMD/Becker muscular dystrphy (BMD) patients without detectable gross deletions were screened by denaturing high performance liquid chromatography (DHPLC) and heteroduplex fragments were identified by subsequent sequencing.

RESULTSSeven causative point mutations, including two novel ones, were detected in 7 patients. Fourteen known polymorphisms and 7 unknown intronic variations were also detected. Five mothers of the patients were obligate carriers.

CONCLUSIONDHPLC is an efficient way of identifying point mutations and the female carriers in DMD families.

Adolescent ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Child, Preschool ; DNA Mutational Analysis ; Dystrophin ; genetics ; Exons ; genetics ; Female ; Genetic Counseling ; Genetic Testing ; methods ; Humans ; Introns ; genetics ; Male ; Muscular Dystrophy, Duchenne ; diagnosis ; genetics ; Point Mutation ; Polymorphism, Genetic ; Pregnancy ; Prenatal Diagnosis ; Sequence Deletion ; genetics

BACKGROUND:The formation of Lewy bodies due to abnormal α-synuclein aggregation is a characteristic pathological change in Parkinson's disease.In recent years,several studies have revealed that the formation of α-synuclein aggregates is closely related to its post-translational modifications.The modification of α-synuclein such as phosphorylation,nitration,acetylation,and ubiquitination has attracted extensive attention in the pathogenesis and progression of Parkinson's disease. OBJECTIVE:To review the research progress in the effect of modification types and sites of α-synuclein on the characteristic pathological formation and progression of Parkinson's disease. METHODS:PubMed and CNKI databases were searched by the first author with the key words of"α-synuclein,Parkinson's disease,phosphorylation,acetylation,ubiquitination,nitration"in English and Chinese respectively to collect and sort out the literature related to abnormal modification of α-synuclein in recent years.Finally,61 articles were included for further review. RESULTS AND CONCLUSION:Abnormal modification of α-synuclein is closely related to its protein structure and its positive and negative charges.Its amino terminus is positively charged and prone to ubiquitination and acetylation modifications.The central hydrophobic region is prone to forming β-pleated sheet due to its hydrophobic property.The carboxyl terminus is negatively charged,which is the main phosphorylation modification region.Phosphorylation modification sites promote phosphorylation modification and are closely related to α-synuclein aggregation,while protein kinases can target the activation of translational modifications,which may help to promote or inhibit aggregate formation.The degradation pathway of α-synuclein mainly plays a role in removing pathological proteins.Various kinase catalysts contribute to impaired protein ubiquitination modifications that lead to abnormal protein accumulation,thereby exacerbating neurodegeneration.The amino-terminal acetylation of α-synuclein improves the shuttle ability of the protein to the cell membrane and slows down the protein aggregation,which may be the protection target of nerve cells.However,the acetylation modification of the mutant protein produces the opposite effect.The protein nitration modification is mainly related to oxidative stress.The aggregation tendency of the protein modified by nitration is enhanced under the action of reactive oxygen species.Different post-translational modifications have different effects.Therefore,elucidating the main mechanisms of their post-translational modifications and inhibiting the post-translational modifications that contribute to protein aggregation may provide a reference for new targets for early diagnosis and treatment of Parkinson's disease.

BACKGROUND:C2 ceramide reduces the formation of Alpha-Synuclein(α-Syn)oligomers as the protein phosphatase 2A agonist,which has an important regulatory effect on cell aging in the central nervous system. OBJECTIVE:To investigate the protective mechanism of C2 ceramide on dopaminergic neurons. METHODS:Twenty-five C57BL/6 mice were randomly divided into control group,model group,C2 ceramide low-,medium-and high-dose groups(n=5 per group).Except for the control group,a mouse model of Parkinson's disease was established by injecting mutant A53T α-Syn oligomers into the left striatum in the other groups.On the 30th day after the striatal injection,three C2 ceramide groups were intragastrically administered with C2 ceramide(1,5,10 μg/g)dissolved in saline at one time,while the control and model groups were administered with the same amount of saline within 30-90 days after modeling,for a total of 60 days.Behavioral changes in each group of mice were observed during this period.On the 90th day after striatal injection,mouse brain tissue was extracted by perfusion under anesthesia,and the changes of dopaminergic neurons in the midbrain substantia nigra were analyzed by immunohistochemical staining.The levels of α-Syn oligomerization and phosphorylation in the midbrain of mice were detected by ELISA,and the changes of enzyme activities related to α-Syn phosphorylation were analyzed. RESULTS AND CONCLUSION:C2 ceramide had an ameliorating effect on Parkinson's disease-like dyskinesia in mice caused by the striatal injection of mutant A53T α-Syn oligomers.High-dose C2 ceramide showed better effects on dyskinesia in mice with Parkinson's disease(P<0.01).The mutant A53T α-Syn oligomers significantly reduced the number of dopaminergic neurons in the substantia nigra of mice(P<0.01),while the number of dopaminergic neurons in the substantia nigra increased significantly in the C2 ceramide high-dose group(P<0.01).The levels of α-Syn oligomers and phosphorylated α-Syn in the brain were significantly reduced in the C2 ceramide high-dose group compared with the model group(P<0.01),while the level of ceramide was increased(P<0.05)and the activity of protein phosphatase 2A was significantly upregulated(P<0.01).To conclude,C2 ceramide can attenuate the neurotoxic effects induced by oligomerized α-Syn by the phosphorylation modification environment of α-Syn in mouse midbrain tissue and protect against the reduction in the number of nigrostriatal dopaminergic neurons in mice,thereby reducing the degree of dyskinesia in Parkinson's disease.

Objective To investigate the correlation between gene polymorphisms of coagulation factor Ⅻ(FⅫ)rs1801020 and resistin rs1862513 and unexplained recurrent spontaneous abortion(URSA).Methods A total of 189 patients diagnosed with URSA and 191 healthy postpartum women during the same period were selected from the obstetric clinic of Changning Maternity and Infant Health Hospital from January 2020 to December 2022.The probe PCR was used to detect gene polymorphisms of rs1801020 and rs1862513 in peripheral blood,and the differences in genotype distribution between the groups were observed.Results The frequencies of geno-types and alleles for F Ⅻ rs1801020 in the URSA-A group were 4.9％(CC),35.7％(CT),59.5％(TT),22.7％(C),and 77.3％(T),respectively.In the control A group,the frequencies were 8.0％(CC),47.1％(CT),44.9％(TT),31.5％(C)and 68.5％(T).The frequencies of genotypes and alleles for resistin rs1862513 in the URSA-B group were 11.3％(CC),47.3％(CG),41.4％(GG),34.9％(C)and 65.1％(G).In the control B group,the frequencies were 10.2％(CC),34.1％(CG),55.7％(GG),27.3％(C)and 72.7％(G).There was no significant difference in genotype frequency of the two loci(P＞0.05),but there was a sig-nificant difference in allele frequency(P＜0.05).The distribution frequency of F Ⅻ rs1801020 T allele in the URSA group was higher than that in the control group(X2=6.32,OR=1.567,95％CI:1.100-2.238,P=0.012).The distribution frequency of resistin rs1862513 G allele in URSA group was lower than that in con-trol group(X2=4.96,OR=1.433,95％CI:1.050-1.969,P=0.026).The mutation of F Ⅻ rs1801020 C to T was a risk factor for the occurrence of URSA,while the mutation of rs1862513 C to G was a protective factor for the occurrence of URSA(P＜0.05).The combined genotype analysis showed that compared to the popu-lation carrying the rs1801020 CC+rs1862513 CC genotype combination,the population carrying the rs1801020 TT+rs1862513 CG genotype had a significantly higher risk of URSA(OR=5.684,95％CI:1.210-30.920,P=0.035).Conclusion FⅫ rs1801020 T allele may increase the risk of URSA and resistin rs1862513 G al-lele may the risk of URSA.People with rs1801020 TT+rs1862513 CG genotype combination is more likely to develop URSA than those with rs1801020 CC+rs1862513 CC genotype combination.

Objective To investigate the value of support vector machine based MRI-radiomics in the differential diagnosis of primary hepatic carcinomas (PHCs). Methods PHCs patients were retrospectively collected from July 2013 to February 2017 in the First Affiliated Hospital of Zhejiang University.All patients underwent unenhanced and enhanced MRI liver scan before surgery,and confirmed by pathology. A total of 294 PHCs patients (305 lesions), including 96 cases (97 lesions) of massive type cholangiocarcinoma (mCC), 107(107 lesions)of hepatocellular carcinoma (HCC), and 91 (101 lesions) of mixed hepatocellular and cholangiocellular carcinomas(HCC-CC).All patients underwent unenhanced and dynamic enhanced MRI liver scan including arterial, portal venous and equilibrium phases. Two hundred and three lesions (65 mCC, 71 HCC, 67 HCC-CC) were assigned into the training set, the remaining 102 lesions(32 mCC,36 HCC,34 HCC-CC)into the validation set,according to a ratio of 2:1.The entire lesions were delineated manually using a region of interest on equilibrium phase of enhanced MRI by using a home-made dedicated software(Analysis Kit,AK,General Electrics,US).Then the least absolute shrinkage and selection operator (LASSO) regression was used to select image features with a method of 10 fold cross-validation, and to reduce the dimensionality. The spearman method was used afterwards to condense the image features by removing redundant.A predictive model of diagnosing the different types of PHCs was established based on support vector machines(SVM),and the accuracy of applying the model in the data sets was used to evaluate the diagnostic efficacy of the model. Results A total of 280 quantitative imaging features were extracted in the training set.Thirty one imaging features were selected after LASSO regression and dimensionality reduction,and 21 features were remained after redundancy removing.The SVM showed the best generalization ability when the first 11 imaging features were used due to the Hughes effect.The 11 imaging features include 4 parameters of histogram,2 of textures,4 of gray-level co-occurrence matrix and 1 of gray-level run length matrix. A predictive model for PHCs was established after the study of the 11 imaging features and a regression analysis using SVM.The accuracy of the predictive model was 80.3% (163/203) in differentiating PHCs in the training set. The accuracy of the model was 75.5% (77/102) after applying it in the validation set. The diagnostic accuracy for HCC-CC, HCC and mCC was 85.3% (29/34), 77.8% (28/36) and 62.5% (20/32), respectively, in the validation set. For HCC-CC, 3 cases were misdiagnosed as mCC and 2 cases as HCC.For HCC,3 cases were misdiagnosed as HCC-CC and 5 cases as mCC.For mCC,9 cases were misdiagnosed as HCC-CC and 3 cases as HCC.The model showed the highest accuracy in predicting HCC-CC.Conclusion Radiomics method based on SVM may have a high accuracy in predicting different pathologic types of PHC,with the highest accuracy for HCC-CC.

OBJECTIVE: To explore the relationship between noise-induced hearing loss, hypertension and abnormal electrocardiogram(ECG) in noise-exposed workers. METHODS: A judgment sampling method was adopted to select 555 male workers with hearing loss as study group and 555 male workers with normal hearing as control group in the similar environment in an automobile manufacturing enterprise in Guangzhou. Pure tone audiometry,blood pressure measurement and ECG examination were performed in both groups to analyze the relationship between hearing loss and hypertension and abnormal ECG. RESULTS: The prevalence rate of hypertension and abnormal ECG was higher in the hearing loss group than the control group(P < 0. 05). The multiple logistic regression analysis showed that after adjusting confounding factors such as age,seniority,body mass index,drinking et al,the risk of hypertension in hearing loss group was higher than the control group(P < 0. 05) and the odds ratio(OR) was 2. 255 [95% confidence interval(CI) : 1. 093-4. 655 ],while adjusting the confounding factor of drinking,the risk of ECG abnormalities in hearing loss group was higher than the control group(P < 0. 05) and the OR was 1. 408(95% CI: 1. 027-1. 930). CONCLUSION: Workers exposed to noise with hearing loss increase the risk of hypertension and abnormal ECG.