Objective:To prepare rabbit polyclonal antibodies against respiratory syncytial virus (RSV) N protein and use them as the detection antibodies to establish a N-ELISA-based method for rapid detection of neutralizing antibodies.Methods:A plasmid of pET30a-N for the expression of RSV N protein was constructed. After purification, the protein was immunized into New Zealand rabbits to prepare polyclonal antibodies, which were used as the detection antibodies. Positive serum samples were diluted and used to neutralize RSV (100 TCID 50/well). Hep-2 cells were inoculated and cultured, and then the cells were fixed with 80% acetone. ELISA was performed to detect RSV N protein in infected cells. When the absorbance value of a well was below the cut-off value, it was regarded as the positive well in the neutralization test. The highest dilution of a positive well serum was the neutralizing antibody titer. After optimizting the antibody dilution, detection time, cell density and the duration of neutralization, the method for neutralizing antibody detection was established based on N-ELISA. The established method was verified by analyzing the influences of different cell generations and edge effects, and calculating the accuracy, repeatability and precision. The correlation between the established method and microneutralization method was analyzed by detecting human RSV IgG-positive serum. Results:The plasmid pET30a-N was successfully constructed, and the expressed N protein showed high purity and good specificity. After the third immunization, the antibody titer in rabbit serum was 1∶51 200, and the antibodies could specifically bind to RSV. The prepared rabbit anti-RSV N polyclonal antibodies had a titer of 1∶51 200, and showed good specificity. The neutralizing antibodies could be detected on day 4 with the established method, and the duration of neutralization was shortened to 30 min. Cell generations and the position of wells in the 96-well plate (edge well and non-edge well) had no significant effect on the method, and the repeatability, precision and accuracy of the method were good. In the detection of 64 RSV IgG-positive human serum samples by the established method and microneutralization method, the correlation coefficient was 0.929 6, indicating a good positive correlation between the two methods.Conclusions:A N-ELISA-based method for rapid neutralizing antibody detection is successfully established, which can be used to evaluate the serum antibody level after RSV vaccination.

Objective:To investigate whether dual-energy computed tomography(DECT) measurement of monosodium urate(MSU) crystal loading can predict the risk of gout flares.Methods:A single-center, prospective, observational study included 229 gout patients initially diagnosed at the Gout Clinic of Qingdao University from August 2021 to February 2022. The patients underwent MSU assessment of the bilateral feet using DECT. Following enrolment, all patients commenced uric acid-lowering therapy(ULT) and were followed up at 3 and 6 months. Patients who experienced at least one flare within 6 months were compared with those who did not, and the odds ratio( OR) for the risk of gout flares was calculated. Results:Patients who experienced gout flare had a significantly longer disease duration[(6.69±5.42) vs(4.14±4.86) years, P<0.01], a higher number of flares in the past year(4.80±1.73 vs 2.02±1. 23, P<0.01), a higher proportion of fatty livers(11.0% vs 1.4%, P<0.05), and a greater volume of MSU crystals in the feet[(3.52±9.74) vs(0.29±0.98)cm 3,P<0.05] compared to patients without gout flare. The results of the multifactorial logistic regression analysis indicated that the number of flares in the past year( OR=1.295, 95% CI 1.032-1.613, P<0.05) and feet MSU crystal volume( OR=3.245, 95% CI 1.164-9.064, P<0.05) were independent risk factors for gout flares. The receiver operating characteristic(ROC) curve indicated the integration of the MSU prediction model into the clinical prediction model resulted in a comprehensive prediction model with an area under curve(AUC) value of 0.780(95% CI 0.710-0.840), sensitivity of 0.83, and specificity of 0.62. Internal validation of the comprehensive prediction model using the Bootstrap method yielded a C-index of 0.770(95% CI 0.701-0.833) for predicting flares. The calibration curve of the model demonstrated a good fit between the predicted probability of flares and the actual probability, indicating high calibration accuracy. Conclusion:The volume of MSU crystals in the feet is an independent risk factor for flares following ULT. A larger volume of MSU crystals in the foot increases the likelihood of a flare. This study provides a basis for early prediction of flare and a reference for early preventive treatment.

Objective:To investigate urinary pH distribution and its influencing factors in gout patients, to provide insights for individualized treatment.Methods:This is a retrospective study. The gout patients in the Gout Outpatient Department of the Affiliated Hospital of Qingdao University from September 2019 to August 2021 were collected. Clinical data were collected and relevant indicators were measured. The patients were divided into different groups according to urinary pH. Clinical characteristics and factors related to urinary pH were compared among the groups. SPSS 23.0 software was used.Results:A total of 2 553 patients were enrolled. There were significant statistical differences in age, body mass index, triglyceride, alanine aminotransferase(ALT), blood urea nitrogen, serum creatinine, estimated glomerular filtration rate(eGFR), blood uric acid, urinary uric acid/creatinine ratio, fraction excretion of uric acid(FEUA) among groups with different urinary pH( F were 5.114, 4.772, 7.170, 4.721, 13.603, 2.812, 3.422, 22.834, 18.230, 26.332, all P<0.05). Urinary uric acid and FEUA in acute group were higher than those in remission group( Z were -2.295, -3.528, both P<0.05). After adjusting for gender, age, eGFR, logistics regression analysis showed that body mass index, triglyceride, total cholesterol, ALT, blood uric acid, and blood urea nitrogen were still risk factors. Multivariate logistic regression analysis showed that triglyceride, blood uric acid, and blood urea nitrogen were independent risk factors associated with acid urine. Linear correlation analysis showed that urinary pH was negatively correlated with body mass index, triglyceride, total cholesterol, blood uric acid, fasting glucose, blood urea nitrogen, ALT( r were -0.079, -0.106, -0.051, -0.186, -0.040, -0.122, -0.051, all P<0.05), but positively correlated with eGFR( r=0.058, P=0.003). Conclusion:The overall urine pH levels in patients with primary gout are below normal reference. Several metabolic components are related to it. Triglyceride, blood uric acid, and blood urea nitrogen are independent risk factors of acidic urine. In clinical practice, attention should be paid to timely alkalization of urine to prevent complications.

Objective:To investigate the clinical characteristics and risk factors of multiple tophi among gout patients.Methods:Gout patients treated at Affiliated Hospital of Qingdao University from September 2017 to September 2021 were included retrospectively. According to the number of tophi, the patients were divided into the multiple tophi group, the single tophi group and the non-tophi group. Clinical data were collected, biochemical indices and urine pH value were determined. One- way ANOVA or Chi-square test was used to compare groups, and multivariate logistic regression was used to analyze the risk factors. Results:The age, disease course, blood pressure, serum uric acid, urea nitrogen, and the rate of family history, smoking, drinking, gout attacks≥2 twice per year, hypertension, cardio-cerebrovascular diseases, kidney stones in the multiple tophi group were significantly higher than those in the single tophi group and the non-tophi group. The glomerular filtration rate, urine pH value and the rate of regular exercise were significantly lower than those of single tophi group and non-tophi group. In the multiple tophi group, 245 cases(44.46%) were involved in the interphalangeal joint or metacarpophalangeal joint, 212 cases(38.47%) were involved in other joints of the upper limb, which was second only to the first metatarsophalangeal joint(349 cases, 63.33%). Logistic regression analysis showed that the course of disease, urea nitrogen, serum uric acid, positive family history, drinking, gout attacks ≥twice per year and hypertension were the risk factors for multiple tophi in gout patients. Conclusion:Patients with a long disease course, elevated uric acid, high urea nitrogen, positive family history, alcohol consumption, frequent gout flare and hypertension are more likely to develop multiple tophi.

Objective:To explore early-onset gout and related risk factors in Shandong Province, and provide decision-making information on prevention.Methods:Data from electronic medical records and face-to face interview were collected from 8 393 patients with gout who first visited the gout clinic of the Affiliated Hospital of Qingdao University from September 2016 to December 2021. Data included demographics, comorbidity and biochemical examinations. The dynamic changes of onset age from 2002 to 2021 were statistically analyzed. The clinical characteristics and related risk factors of patients with early-onset and late-onset gout were statistically analyzed.Results:The age of onset of gout decreased significantly from 2002 to 2021. Compared with 2002, the average age of onset in 2021 decreased by 2.3 years [(41.9±10.6 vs 39.6±14.0) years]. The median age of onset decreased by 3 years in 2012-2021 compared with 2002-2011(37 vs 40 years, P<0.001). The proportion of gout patients with onset age<40 years old increased significantly, from 45.1% in 2002 to 57.8%, and increased by 12.7% in 20 years( P<0.001). The constituent ratios of 20-29 years old group( Ptrend<0.001) and≤19 years old group( Ptrend=0.011) increased by 9.3%( P<0.001) and 4.2%( P=0.002) over 20 years, which was the highest increase among all age groups with onset age<40 years old. Multivariate stepwise linear regression analysis showed that positive family history, blood uric acid level, metabolic syndrome and smoking were independent risk factors for early onset of gout. Conclusion:The age of gout onset in tends to be younger. The increase of the proportion of patients younger than 30 years old is probably the key factor leading to the early-onset gout in Shandong Province. Early and effective intervention on the risk factors related to early-onset gout is essential to prevent the early-onset gout as well as to reduce the prevalence of gout and complications.

Objective:To analyze the clinical characteristics and risk factors associated with the formation of subcutaneous tophi among young gout patients.Methods:Gout patients treated at the Affiliated Hospital of Qingdao University from September 2016 to June 2020 were included. The clinical information was collected and relevant biochemical indices were detected. Fasting urine was collected to test urine pH value, urine uric acid and urine creatinine. Patients were divided into young tophi group and non-tophi group according to age. The measurement data of normal distribution was expressed as Mean±Standard deviation, and independent sample t test and one-way analysis of variance were used. The counting data was tested by Chi-square test. The risk factors were analyzed by logistic regression. Results:A total of 4 798 primary gout patients were collected. There were 915 patients with subcutaneous tophi, 2 308 young gout patients, 252 young gouty tophi patients among them. The average BMI, waist circumference, hip circumference, triglyceride level, serum uric acid level, glomerular filtration rate, alanineamino -transferase (ALT) and aspartate amino -transferase (AST) in the young tophi group were significantly higher than those in the middle-age tophi group ( F=46.074, 2.551, 9.203, 10.370, 15.118, 68.741, 35.023, 5.175, all P<0.05). Average age of disease onset, systolic blood pressure, fasting blood glucose, urine FEUA, Uua/Ucr and urea nitrogen level in young tophi group were significantly lower than those in middle-age tophi group ( F=474.876, 7.629, 6.441, 34.877, 3.633, 50.867, all P<0.05]. The age [(35±7) years old vs (33±7) years old], disease course [(7±4) years vs (4±3) years], blood pressure [(139±17) mmHg vs (135±16) mmHg], [(90±13) mmHg vs (86±12) mmHg], serum triglyceride [(2.6±2.1) mmol/L vs (2.4±2.0) mmol/L], total cholesterol [(4.9±1.4) mmol/L vs (4.6±1.4) mmol/L], serum uric acid [(547±171) μmol/L vs (490±160) μmol/L], urea nitrogen [(5.0±2.0) mmol/L vs (4.4±1.7) mmol/L], family history (27.0% vs 19.6%) and smoking rate(56.0% vs 48.9%) of tophi patients were significantly higher than those of non-tophi patients in young patients ( t=4.717, P<0.05; t=12.838, P<0.05; t=3.414, P<0.05; t=4.676, P<0.05; t=2.085, P<0.05; t=2.451, P<0.05; t=5.308, P<0.05; t=4.090, P<0.05; χ2=7.423, P<0.05; χ2=4.235, P<0.05) . The age of disease onset [(28±6) years vs (29±7) years] and glomerular filtration rate [(96±21) ml·min -1·1.73 m -2vs (103±21) ml·min -1·1.73 m -2] were statistically significantly lower than those of non-tophi patients ( t=-2.711, P<0.01; t=-4.907, P<0.01). Logistics regression analysis showed that age, course of disease, blood pressure, blood lipids level, serum uric acid level, family history of gout and smoking were risk factors for the formation of tophi in young people. After further adjusted for age, course of disease and family history of gout, it was found that serum uric acid, systolic blood pressure, diastolic blood pressure and urea nitrogen remined risk factors for tophi, while glomerular filtration rate remained a protective factor in young patients. Conclusion:Young tophi patients are always obese and have lipid metabolism disorder. Young patients with high level of serum uric acid and blood pressure, decreased renal function are prone to complicate with subcutaneous tophi. More attention should be paid in clinical practice to prevent or delay the formation of tophi.

Objective:To investigate the associations between serum uric acid levels during the third trimester of pregnancy and risks of adverse pregnancy outcomes.Methods:In this retrospective study, a cohort of 7 995 pregnant women who were hospitalized for childbirth from January 2014 to January 2019 were collected to compare pregnancy outcomes between subjects with or without hyperuricemia (HUA). A smooth curve analysis was used to evaluate the relationship between uric acid levels and preterm delivery, low birth weight and smaller than gestational age. Logistic regression analyses were performed to identify risk factors for adverse pregnancy outcomes, and the interaction of the factors.Results:During the third trimester of pregnancy, the uric acid levels of about 10% pregnant women were over 420 μmol/L. In those with HUA, the median neonatal birth weight was 2 590 (1 790, 3 410) g, the probability of premature birth was 49.81%, and the incidence of small than gestational age was 20.41%. These were significantly different from the women without HUA (the median neonatal birth weight: 3300 (2850, 3640) g; the probability of premature birth 23.09%; the incidence of small than gestational age 6.55%, respectively) (All P<0.001). Maternal uric acid levels were negatively correlated with neonatal birth weight, and positively correlated with the risk of smaller than gestational age. It has a U-shaped association with the probability of premature birth, and the lowest probability of premature birth was at 200-400 μmol/L of the uric acid. Risks of low birth weight (adjusted β=-5.22, 95% CI-6.46—-3.99) and smaller than gestational age (adjusted OR=1.03, 95% CI 1.02-1.04) were increased in the function of uric acid levels. High uric acid, hypertension, oligoamnios and preeclampsia were important risk factors for the adverse pregnancy outcomes. The risk of preterm delivery and low birth weight enhanced when hyperuricemia combined with hypertension and preeclampsia. Conclusions:Serum uric acid level can be used as one of reliable markers for predicting adverse pregnancy outcomes, which might provide theoretical basis for clinical intervention in practice.

Objective To study the clinical effect of Yaotongning capsule combined with etoricoxib for the pain and inflammation of lumbar vertebrae in elderly patients with lumbar osteoarthritis. Methods 120 elderly patients with lumbar osteoarthritis admitted to our hospital from January 2016 to June 2018 were randomly divided into the control group and the observation group, with 60 patients in each group. Patients in the control group were treated with etoricoxib, while patients in the observation group were treated with etoricoxib plus Yaotongning capsule orally. Both groups received medications for 2 weeks. Spinal pain and quality of life score changes were recorded. The inflammatory cytokines in serum TNF-α, GM-CSF, COX-2 and BMP-2 levels were monitored. The clinical efficacy was compared and drug safety profile was evaluated for two groups. Results The effective rates of the control group and the observation group were 78.33% and 91.67% respectively. The effective rate in the observation group weas significantly higher (P<0.05). After treatment, the VAS score for the patients in the observation group was significantly lower than that in the control group (P<0.05). The SF-36 score in the observation group was significantly increased (P<0.05), and the levels of TNF-α,GM-CSF and COX-2 in the serum were significantly lower than those in the control group (P<0.05), and the levels of BMP-2 were significantly increased (P<0.05). Conclusion Yaotongning capsule combined with etoricoxib in the treatment of senile lumbar osteoarthritis has definite curative effect. It significantly reduced lumbar pain, improved quality of life, inhibited inflammatory reaction, and had a better drug safety profile. The further clinical investigation for the combination therapy is warranted.

Objective: To investigate the risk factors for susceptibility of abnormal liver function in patients with gout. Methods: A total of 5 044 cases of male gout patients in remission were selected and divided into normal liver function group with 3 693 patients and abnormal liver function group with 1 351 patients. The clinical information was collected and relevant biochemical indices were detected. Serum uric acid(SUA) was divided into quartiles, and its associations with elevated ALT were evaluated. Results: There were significant differences in the history of drinking, family history, combining with hyperlipidemia, fatty liver, and coronary heart disease between the abnormal liver function group and normal function group(P<0.05 or P<0.01). There were significant statistical differences in age, disease duration, body mass index, waist circumference, diastolic blood pressure, serum cholesterol and triglyceride, uric acid, and creatinine clearance rate between 2 groups(P<0.01), while without significant difference in history of smoking, regular exercise, combining hypertension and diabetes, the means of systolic blood pressure, and fasting blood glucose(all P>0.05). Further logistic regression analysis indicated that body mass, waist circumference, combining fatty liver, higher SUA level, higher cholesterol and triglyceride were risk factors of the early onset of abnormal liver function. ALT and the proportion of abnormal liver function were increased with the increase of UA. After adjustment for BMI, TG, TC and fatty liver, the ALT level and the proportion of abnormal liver function decreased significantly while still showed an upward trend. Conclusion Patients with obesity, high level of uric acid, high blood lipids and fatty liver were more likely to develop abnormal liver function, SUA was independently associated with elevated ALT.

Objective: To screen gene mutation information of gout pedigree through whole genome sequencing and to carry out preliminary analysis. Methods: One typical gout pedigree was selected as the study subjects. The clinical data and the peripheral blood samples were collected and constructed charts of the pedigree. DNAs were extracted from peripheral blood and analyzed by the whole genome sequencing, and by the software analysis and comparison, screening out the pathogenic genes and related mutations. Then the verifications were conducted in the family members and the controls. Bioinformatics software was applied to predict the effect of mutation on gene expression. Results: Based on the sequencing results, advanced informational analysis was performed to screen out the mutations 1040-8 A> G near the 5 ′end near the exon 8 of the PLAA gene. The results showed that all the gout patients in the family had 1040 -8 A> G sites, and none of the mutants were found in the non-gout group and 200 controls; bioinformatics analysis suggested that the mutation could affect PLAA gene expression, but not affecting PLAA mRNA structure. Conclusion PLAA gene 1040-8 A> G mutation is separated from patients in the gout pedigree, and the newly discovered PLAA gene may act as a gout pathogenic gene.