BACKGROUND:Platelet-rich fibrin(PRF)has many advantages,such as simple preparation,low production cost,and high safety,and has been widely used in the study of bone defect repair in oral and maxillofacial surgery,but there are problems such as too fast degradation rate and short release time of growth factors. OBJECTIVE:PRF was loaded into gelatin methacryloyl(GelMA)hydrogel and its osteogenic properties were analyzed by in vivo and in vitro experiments. METHODS:(1)New Zealand white rabbit venous blood was extracted to prepare PRF.GelMA hydrogels containing 0,0.05,0.075,and 0.1 g PRF were prepared,respectively,and were recorded as GelMA,GelMA/PRF-0.05,GelMA/PRF-0.075,and GelMA/PRF-0.1,respectively,to characterize the micromorphology and in vitro slow-release properties of the hydrogels.(2)Four kinds of hydrogels were co-cultured with MC3T3-E1 cells,respectively,and the cell proliferation activity was detected with the single cultured cells as the control.After osteogenic induction,alkaline phosphatase activity,mineralization ability,mRNA and protein expression levels of osteogenic genes(osteocalcin,osteopontin,RUNX2),ERK1/2-p38 MAPK pathway protein mRNA and protein expression levels were detected.(3)Fifteen New Zealand white rabbits were taken.Four full-layer bone defects of 8 mm diameter were prepared in the skull of each rabbit,one of which was implanted without any material(blank control group),and the other three were implanted with GelMA hydrogel,PRF,and GelMA/PRF-0.1 hydrogel,respectively.The bone defect was detected by Micro-CT and bone morphology was observed at 4,8,and 12 weeks after operation. RESULTS AND CONCLUSION:(1)Scanning electron microscopy observed that all the hydrogels of the four groups had honeycomb pore structure,and the pore size of the hydrogels decreased slightly with the increase of PRF content,but there was no significant difference between the groups.The three groups of GelMA/PRF hydrogel could release transforming growth factor β1 and insulin-like growth factor 1 at a certain rate,and the cumulative release of transforming growth factor β1 and insulin-like growth factor 1 increased significantly with the extension of time.(2)CCK-8 assay and live/dead staining showed that GelMA/PRF hydrogel could promote the proliferation of MC3T3-E1 cells.The results of alkaline phosphatase staining,alizarin red staining,and osteogenic gene detection showed that GelMA/PRF hydrogel could promote the osteogenic differentiation of MC3T3-E1 cells,and inhibit the expression of ERK1/2-p38 MAPK pathway protein,and showed a PRF content dependence.(3)Micro-CT scan showed that the bone mineral density and bone volume fraction in the bone defect of GelMA/PRF-0.1 hydrogel group were higher than those in the other three groups(P<0.05).Hematoxylin-eosin staining showed that compared with the other three groups,GelMA/PRF-0.1 hydrogel group had faster and more mature new bone formation at the bone defect.(4)These findings indicate that GelMA/PRF hydrogel has good osteogenic activity both in vivo and in vitro,which may be related to inhibiting the expression of ERK1/2-p38 MAPK pathway protein.

Objective:To investigate the effects of cryopreservation on the results of nucleic acid detection and culture for Bordetella pertussis in residual culture-positive nasopharyngeal swab specimens, aiming to provide the basis for specimens preservation, transport and centralized detection. Methods:In this cross-sectional study, the residual nasopharyngeal swab specimens which were culture-positive for Bordetella pertussis were collected in the Children′s Hospital, Zhejiang University School of Medicine from January to August in 2022. The specimens were placed at ?20 ℃ and?70 ℃ by random number table method, respectively. Re-detection by culture and PCR for Bordetella pertussis were conducted after these specimens were frozen for 114.3±31.9 days. The specimens were grouped according to the cryopreservation temperature and the semi-quantitative results by bacteria culture. The positive rates of the results were compared with χ 2 test between groups. Results:A total of 244 nasopharyngeal swabs specimens were included and 166 were culture-positive after cryopreservation, the positive rate decreased by 32%. Among them, the positive rate of re-culture of specimens containing low bacterial loads decreased by 56% after cryopreservation. However, there was no significant difference in the positive rate of culture between the specimens freezing at ?70 ℃ and ?20 ℃ (χ2=1.65, P=0.20). The positive rate of DNA detection decreased by 10.6% (88.9% vs 78.3%) after cryopreservation. The positive rate of the ?70 ℃ storage group was significantly higher than that of the ?20 ℃ group (χ2=5.11, P=0.02). The positive rate of the re-detection of DNA of nasopharyngeal swabs with low bacteria loads in ?70 ℃ storage group was significantly higher than that of the ?20 ℃ group (χ2=4.86, P=0.03). While for the samples with a bacterial load of "+" or more, there was no significant difference in the positive rate of DNA detection after cryopreservation between the ?20 ℃ and -70 ℃ (χ2=1.25, P=0.26) groups. The positive rate of nasopharyngeal swab culture after cryopreservation was 68.0% (166/244), which was significantly lower than the DNA detection positive rate of 78.3% (191/244, χ2=6.52, P=0.01). Conclusions:Cryopreservation nasopharyngeal swabs specimens could be used for Bordetella pertussis culture and nucleic acid detection. The bacterial load in the original sample affects the positive detection rate after cryopreservation. Cryopreservation has less influence on the positive rate of the result of nucleic acid detection when compared with culture. Preservation at ?70 ℃ is superior to ?20 ℃.

Objectives:To investigate the association between the triglyceride-glucose(TyG)index and risk of non-alcoholic fatty liver disease(NAFLD)in young and middle-aged(<60 years)adults.Methods:From June 2006 to October 2007,47 675 employees of Kailuan Group with no liver disease were selected as the study objects.Based on the TyG index quartile,participants were divided into Q1 group(TyG index≤8.08,n=11 924),Q2 group(8.0836.46,n=11 919),the association between TyG index,cum-TyG and cumulative exposure time and the risk of NAFLD was analyzed.Results:The average age of the study population was(44.3±8.7)years,36 345 participants were males(76.23%).During a median follow-up period of 11.55(7.28,13.89)years,4 635(9.72%)participants developed new-onset NAFLD.After adjusting for confounders,cox regression analysis showed that compared with the Q1 group,the HR(95%CI)for NAFLD in the Q2 to Q4 groups were 1.328(1.191-1.480),1.591(1.430-1.770),and 2.106(1.861-2.384),respectively,Ptrend<0.001.Compared with the cum-Q1 group,the HR(95%CI)for NAFLD in the cum-Q2 to cum-Q4 groups were 1.571(1.426-1.730),2.123(1.935-2.330)and 2.593(2.367-2.840),respectively,Ptrend<0.001.Compared with the TyG index for 0 year,the HR(95%CI)of NAFLD for 2,4 and 6 years was 1.333(1.196-1.486),1.879(1.690-2.088)and 3.184(2.860-3.545),respectively,Ptrend<0.001.Conclusions:Increased TyG index is an independent risk factor for the new-onset NAFLD in young and middle-aged population.

Objectives:To investigate the association between the triglyceride-glucose(TyG)index and risk of non-alcoholic fatty liver disease(NAFLD)in young and middle-aged(<60 years)adults.Methods:From June 2006 to October 2007,47 675 employees of Kailuan Group with no liver disease were selected as the study objects.Based on the TyG index quartile,participants were divided into Q1 group(TyG index≤8.08,n=11 924),Q2 group(8.0836.46,n=11 919),the association between TyG index,cum-TyG and cumulative exposure time and the risk of NAFLD was analyzed.Results:The average age of the study population was(44.3±8.7)years,36 345 participants were males(76.23%).During a median follow-up period of 11.55(7.28,13.89)years,4 635(9.72%)participants developed new-onset NAFLD.After adjusting for confounders,cox regression analysis showed that compared with the Q1 group,the HR(95%CI)for NAFLD in the Q2 to Q4 groups were 1.328(1.191-1.480),1.591(1.430-1.770),and 2.106(1.861-2.384),respectively,Ptrend<0.001.Compared with the cum-Q1 group,the HR(95%CI)for NAFLD in the cum-Q2 to cum-Q4 groups were 1.571(1.426-1.730),2.123(1.935-2.330)and 2.593(2.367-2.840),respectively,Ptrend<0.001.Compared with the TyG index for 0 year,the HR(95%CI)of NAFLD for 2,4 and 6 years was 1.333(1.196-1.486),1.879(1.690-2.088)and 3.184(2.860-3.545),respectively,Ptrend<0.001.Conclusions:Increased TyG index is an independent risk factor for the new-onset NAFLD in young and middle-aged population.

Objective:To investigate the effects of cryopreservation on the results of nucleic acid detection and culture for Bordetella pertussis in residual culture-positive nasopharyngeal swab specimens, aiming to provide the basis for specimens preservation, transport and centralized detection. Methods:In this cross-sectional study, the residual nasopharyngeal swab specimens which were culture-positive for Bordetella pertussis were collected in the Children′s Hospital, Zhejiang University School of Medicine from January to August in 2022. The specimens were placed at ?20 ℃ and?70 ℃ by random number table method, respectively. Re-detection by culture and PCR for Bordetella pertussis were conducted after these specimens were frozen for 114.3±31.9 days. The specimens were grouped according to the cryopreservation temperature and the semi-quantitative results by bacteria culture. The positive rates of the results were compared with χ 2 test between groups. Results:A total of 244 nasopharyngeal swabs specimens were included and 166 were culture-positive after cryopreservation, the positive rate decreased by 32%. Among them, the positive rate of re-culture of specimens containing low bacterial loads decreased by 56% after cryopreservation. However, there was no significant difference in the positive rate of culture between the specimens freezing at ?70 ℃ and ?20 ℃ (χ2=1.65, P=0.20). The positive rate of DNA detection decreased by 10.6% (88.9% vs 78.3%) after cryopreservation. The positive rate of the ?70 ℃ storage group was significantly higher than that of the ?20 ℃ group (χ2=5.11, P=0.02). The positive rate of the re-detection of DNA of nasopharyngeal swabs with low bacteria loads in ?70 ℃ storage group was significantly higher than that of the ?20 ℃ group (χ2=4.86, P=0.03). While for the samples with a bacterial load of "+" or more, there was no significant difference in the positive rate of DNA detection after cryopreservation between the ?20 ℃ and -70 ℃ (χ2=1.25, P=0.26) groups. The positive rate of nasopharyngeal swab culture after cryopreservation was 68.0% (166/244), which was significantly lower than the DNA detection positive rate of 78.3% (191/244, χ2=6.52, P=0.01). Conclusions:Cryopreservation nasopharyngeal swabs specimens could be used for Bordetella pertussis culture and nucleic acid detection. The bacterial load in the original sample affects the positive detection rate after cryopreservation. Cryopreservation has less influence on the positive rate of the result of nucleic acid detection when compared with culture. Preservation at ?70 ℃ is superior to ?20 ℃.

The plasma matrix is a kind of autologous blood conduct.It has been widely used in maxillofacial tissue regeneration,skin cosmetology and some other fields.Recently,to preserve the dental pulp as well as the teeth,pulp re-generation therapy and apical surgery have become increasingly important as well as the applications of bioactive materi-als.As a kind of autologous bioactive material,the plasma matrix has some natural advantages as it is easy to obtain and malleable.The plasma matrix can be used in the following cases:①pulp revascularization of young permanent teeth with open apical foramina that cannot stimulate apical bleeding;② apical barrier surgery with bone defects and large ar-ea perforation repair with bone defects or root sidewall repair surgery;③ apical surgeries of teeth with large area of api-cal lesions,with or without periodontal diseases.The plasma matrix is a product derived from our blood,and there are no obvious contraindications for its use.Several systematic reviews have shown that the plasma matrix can effectively promote the regenerative repair of dental pulp in patients with periapical diseases.However,the applications of plasma matrix are different because its characteristics are affected by different preparation methods.In addition,there is still a lack of long-term clinical researches on the plasma matrix,and the histological evidences are difficult to obtain,so a large number of in vitro and in vivo experimental studies are still needed.This article will describe the applications of different kinds of plasma matrix for dental pulp regeneration and bone tissue regeneration in apical surgeries to provide references for clinicians in indication selection and prognosis evaluation.

OBJECTIVE To study the pharmacodynamics and pharmacokinetics of semaglutide(Sem)capsules in type 2 diabetic model rats.METHODS Male SD rats were divided into the normal control group,type 2 diabetic model group and model+Sem capsules(0.839,1.678 and 2.517 mg·kg-1)groups.A type 2 diabetic rat model was induced by high sugar and high fat diet feeding combined with ip given streptozotocin(STZ)injection.Seven days after modeling,the model+Sem capsules group was ig given Sem capsules at the corresponding dose in a fasting state,once a day,for 14 d.Body mass,fasting blood glucose(FBG),and glycosylated hemoglobin(HbA1c)levels were regularly mea-sured in each group of rats.Plasma from rats in the model+Sem capsules 0.839,1.678 and 2.517 mg·kg-1 groups at different time points was collected at the end of the continuous administration of Sem capsules,and the content of Sem in the plasma of rats was determined by liquid chromatography-tandem mass spectrometry.Concentration-time curves were plotted,and the main pharmacokinetic parameters were fitted by the WinNonlin non-atrial model method.RESULTS Compared with the model group,the body mass of rats in model+Sem capsules dosing groups decreased significantly after 7 and 14 d of Sem capsules intervention(P<0.05,P<0.01),so did FBG(P<0.01)and the HbA1c level(P<0.01).Meanwhile,FBG and HbA1c levels of rats in model+Sem capsules 1.678 and 2.517 mg·kg-1 groups were not significantly different from those of the normal control group after 14 d of Sem capsules intervention,suggesting that FBG and HbA1c levels were basically restored to normal.Phar-macokinetic results showed that the elimination half-life(t1/2)of Sem in plasma after ig administration of Sem capsules 0.839,1.678,and 2.517 mg·kg-1 for 14 d in rats was 7.40±1.34,7.48±0.33 and(8.23±0.90)h,respectively,the peak concentration(Cmax)was 18±9,81±23 and(256±53)μg·L-1,time to peak(Tmax)was 0.06±0.13,1.56±0.88,(1.50±1.00)h,respectively,the area under the curve(AUC0-t)was 158±76 μg·h·L-1,858±310 and(3795±1539)μg·h·L-1,and the accumulation index was 1.12±0.05,1.12±0.01 and 1.15±0.04,respectively.CONCLUSION Sem capsules ig administrated can effectively reduce body mass,FBG and HbA1c levels in type 2 diabetic model rats,and lead to glucose reduction and by mass loss.After 14 d of continuous administration of Sem capsules,there is no accu-mulation of semaglutide in rats in the dose range of 0.839-2.517 mg·kg-1,and the exposure increases with the dose.

Objective:To investigate the protective effect of calycosin on microgravity-induced muscle atrophy by using real-time shear wave elastography (RT-SWE).Methods:The potential key active compound calycosin of anti-muscular atrophy in Astragali Radix was screened by systematic pharmacology. Eighteen healthy male Sprague-Dawley rats were divided into the control group [0.5% carboxymethyl cellulose-Na (CMC-Na) gavage], the hind limb unloading (HLU)+CMC-Na group (HLU+0.5% CMC-Na gavage), and the HLU+calycosin group (HLU+calycosin gavage) according to the method of random number table, with 6 rats in each group. After 28 d of continuous administration, the organ index, the toxicity of liver and kidney, the wet weight of soleus muscle and the ratio of muscle weight to body weight was measured, respectively. The non-invasive RT-SWE was used to evaluate the thickness and elastic modulus of rectus femoris in each group and the one-way analysis of variance was used to compare the differences among groups.Results:There was no significant difference in organ index, liver and kidney toxicity among different groups of rats (all P>0.05). There were significant differences in the weight of soleus muscle and the ratio of muscle weight to body weight among different groups of rats ( F=60.66, 56.44, both P<0.001). Compared with the HLU+CMC-Na group, the weight of soleus muscle and the ratio of muscle weight to body weight in the HLU+calycosin group increased, and the differences were significant (both P<0.01). The thickness and elastic modulus of rectus femoris of rats in different groups were significantly different ( F=35.47, 14.68, both P<0.001). Compared with the HLU+CMC-Na group, the muscle thickness and elastic modulus of rats in HLU+calycosin group were increased, and the differences were significant (both P<0.01). Conclusions:The treatment of calycosin has no side effects on rats. It can improve the thickness and elastic modulus of rectus femoris, and effectively prevent microgravity-induced muscle atrophy, which may provide a new candidate drug for astronaut muscular atrophy.

Objective:To investigate the protective effect of calycosin on microgravity-induced muscle atrophy by using real-time shear wave elastography (RT-SWE).Methods:The potential key active compound calycosin of anti-muscular atrophy in Astragali Radix was screened by systematic pharmacology. Eighteen healthy male Sprague-Dawley rats were divided into the control group [0.5% carboxymethyl cellulose-Na (CMC-Na) gavage], the hind limb unloading (HLU)+CMC-Na group (HLU+0.5% CMC-Na gavage), and the HLU+calycosin group (HLU+calycosin gavage) according to the method of random number table, with 6 rats in each group. After 28 d of continuous administration, the organ index, the toxicity of liver and kidney, the wet weight of soleus muscle and the ratio of muscle weight to body weight was measured, respectively. The non-invasive RT-SWE was used to evaluate the thickness and elastic modulus of rectus femoris in each group and the one-way analysis of variance was used to compare the differences among groups.Results:There was no significant difference in organ index, liver and kidney toxicity among different groups of rats (all P>0.05). There were significant differences in the weight of soleus muscle and the ratio of muscle weight to body weight among different groups of rats ( F=60.66, 56.44, both P<0.001). Compared with the HLU+CMC-Na group, the weight of soleus muscle and the ratio of muscle weight to body weight in the HLU+calycosin group increased, and the differences were significant (both P<0.01). The thickness and elastic modulus of rectus femoris of rats in different groups were significantly different ( F=35.47, 14.68, both P<0.001). Compared with the HLU+CMC-Na group, the muscle thickness and elastic modulus of rats in HLU+calycosin group were increased, and the differences were significant (both P<0.01). Conclusions:The treatment of calycosin has no side effects on rats. It can improve the thickness and elastic modulus of rectus femoris, and effectively prevent microgravity-induced muscle atrophy, which may provide a new candidate drug for astronaut muscular atrophy.

Objective:To study the collapse of the contralateral femoral head after the total hip arthroplasty (THA) in patients with bilateral steroid-induced femoral head necrosis leg-length discrepancy (LLD) influences.Methods:A total of 108 patients with bilateral steroid-induced femoral head necrosis who were treated in Honghui Hospital Affiliated to Xi′an Jiaotong University from June 2014 to June 2016 underwent THA surgery on the hip joints that had symptoms and developed to Association Research Circulation Osseous (ARCO) Ⅲ. At the same time, the non-surgical hip-preserving treatment of the non-collapsed femoral head developed to the ARCO Ⅱ stage was performed. The follow-up period was 2 years, and 98 cases were finally included. According to the size of the leg-length discrepancy [LLD<3 mm group ( n=50), LLD≥3 mm group ( n=48)] and the type of leg-length discrepancy[non collapse side longer group ( n=58) and shorter group ( n=58)], the collapse of the femoral head and the THA were observed. Results:Finally, a total of 56 cases of femoral head collapse occurred in the non collapse side of the hip, of which 50 cases underwent THA within 24 months. There were significant statistical differences in THA and femoral head collapse between LLD<3 mm group and LLD≥3 mm group, non collapse side longer group and non collapse side shorter group ( P<0.05). The 2-year survival rate without collapse in the LLD<3 mm group and LLD≥3 mm group were 52.1% and 34.0%, respectively, and the 2-year survival rates in the longer and shorter non-collapsed limb groups were 56.9% and 22.5%, respectively. Compared with patients with moderate lesions, the survival rate of femoral heads in patients with larger lesions was lower ( OR: 4.25, 95% CI: 1.55-11.26; P=0.003). LLD<3 mm group ( OR: 0.24, 95% CI: 0.06-0.50; P<0.01) or non collapse side longer group ( OR: 0.13, 95% CI: 0.04-0.29; P<0.01) had lower risk of contralateral femoral head collapse after THA. Conclusions:For patients with bilateral steroid-induced femoral head necrosis who have collapsed lateral THA, postoperative leg-length discrepancy extremities is a potential risk factor for collapse of non-collapsed femoral head. LLD<3 mm and avoiding shortening of the uncollapsed limb may reduce the risk of collapse of the uncollapsed femoral head.