BACKGROUND:The anterior cruciate ligament has unique nonlinear mechanical properties under a complex physiological loading environment.Elastin is an important contributor to the mechanical properties of the anterior cruciate ligament,but its mechanical response to the anterior cruciate ligament under axial tension is not clear. OBJECTIVE:To quantitatively analyze the effect of elastin on the tensile mechanical response of the anterior cruciate ligament. METHODS:Elastase solution and control buffer were prepared.The porcine anterior cruciate ligament samples were prepared into small-size samples and randomly soaked in 0,0.1,1.0,2.0,5.0,and 10.0 U/mL elastase solution for 6 hours,and other small samples of the same size were soaked in 2 U/mL elastase solution for 0,1,3,6,9,and 12 hours.To determine suitable soaking conditions for elastin-targeted enzymes and verify the digestive effect,histological staining was used to compare the effects of enzyme treatment on tissue structure and composition.The ligament samples were randomly divided into elastase-treated group and PBS group,and immersed in 2 U/mL elastase solution and PBS buffer for 6 hours,respectively.A mechanical tensile test was performed before and after immersion. RESULTS AND CONCLUSION:(1)The biochemical results showed that being treated in 2 U/mL elastase solution for 6 hours could reduce the elastin content by 31.1%,and had no significant effect on other mechanical-related components in the tissue.(2)The histological results showed that elastase was able to penetrate the tissue,and the loose degree of tissue increased after treatment.(3)In the mechanical results before and after treatment,the mechanical properties of the PBS group decreased significantly,only the low-tension elastic modulus increased significantly and the initial length increased significantly in the elastase-treated group.(4)The intergroup comparison results showed that there was no significant difference between the two groups in pre-treatment,but the low-tension elastic modulus,initial slopes,saturated slopes,and initial length of the elastase-treated group after treatment were significantly higher than those in the PBS group.(5)These results suggest that elastin degradation significantly affects the biomechanical properties of the anterior cruciate ligament and further complements our understanding of the structure-function relationship of the anterior cruciate ligament.

Nonalcoholic fatty liver disease(NAFLD)has developed into the most common chronic liver disease and can lead to liver cancer.Our laboratory previously developed a novel prescription for NAFLD,"Eight Zhes Decoction"(EZD),which has shown good curative effects in clinical practice.However,the pharmaco-dynamic material basis and mechanism have not yet been revealed.A strategy integrating lipidomics,network pharmacology and pharmacokinetics was used to reveal the active components and mecha-nisms of EZD against NAFLD.The histopathological results showed that EZD attenuated the degrees of collagen deposition and steatosis in the livers of nonalcoholic steatofibrosis model mice.Furthermore,glycerophospholipid metabolism,arachidonic acid metabolism,glycerolipid metabolism and linoleic acid metabolism with phospholipase A2 group IVA(PLA2G4A)and cytochrome P450 as the core targets and 12,13-cis-epoxyoctadecenoic acid,12(S)-hydroxyeicosatetraenoic acid,leukotriene B4,prostaglandin E2,phosphatidylcholines(PCs)and triacylglycerols(TGs)as the main lipids were found to be involved in the treatment of NAFLD by EZD.Importantly,naringenin,artemetin,canadine,and bicuculline were iden-tified as the active ingredients of EZD against NAFLD;in particular,naringenin reduces PC consumption by inhibiting the expression of PLA2G4A and thus promotes sufficient synthesis of very-low-density lipoprotein to transport excess TGs in the liver.This research provides valuable data and theoretical support for the application of EZD against NAFLD.

Objectives:This study aimed to assess the efficacy and safety of bendamustine in combination with rituximab (BR regimen) for the treatment of newly diagnosed indolent B-cell non-Hodgkin's lymphoma (B-iNHL) and elderly mantle cell lymphoma (eMCL) .Methods:From December 1, 2020 to September 10, 2022, a multi-center prospective study was conducted across ten Grade A tertiary hospitals in Shandong Province, China. The BR regimen was administered to evaluate its efficacy and safety in newly diagnosed B-iNHL and eMCL patients, and all completed at least four cycles of induction therapy.Results:The 72 enrolled patients with B-iNHL or MCL were aged 24-74 years, with a median age of 55 years. Eastern Cooperative Oncology Group (ECOG) performance status scores of 0-1 were observed in 76.4% of patients, while 23.6% had scores of 2. Disease distribution included follicular lymphoma (FL) (51.4% ), marginal zone lymphoma (MZL) (33.3% ), eMCL (11.1% ), and the unknown subtype (4.2% ). According to the Ann Arbor staging system, 16.7% and 65.3% of patients were diagnosed with stage Ⅲ and stage Ⅳ lymphomas, respectively. Following four cycles of BR induction therapy, the overall response rate was 98.6%, with a complete response (CR) rate of 83.3% and a partial response (PR) rate of 15.3%. Only one eMCL patient experienced disease progression during treatment, and only one FL patient experienced a relapse. Even when evaluated using CT alone, the CR rate was 63.9%, considering the differences between PET/CT and CT assessments. The median follow-up duration was 11 months (range: 4-22), with a PFS rate of 96.8% and an OS rate of 100.0%. The main hematologic adverse reactions included grade 3-4 leukopenia (27.8%, with febrile neutropenia observed in 8.3% of patients), grade 3-4 lymphopenia (23.6% ), grade 3-4 anemia (5.6% ), and grade 3-4 thrombocytopenia (4.2% ). The main non-hematologic adverse reactions such as fatigue, nausea/vomiting, rash, and infections occurred in less than 20.0% of patients.Conclusion:Within the scope of this clinical trial conducted in China, the BR regimen demonstrated efficacy and safety in treating newly diagnosed B-iNHL and eMCL patients.

Objective:To investigate the standardization of implementing enteral nutrition in patients with stroke among nurses in Guangdong province.Methods:The results of 175 valid questionnaires submitted by 175 nurses from 60 hospitals in Guangdong province from June to July 2022 were analyzed. Contents of the questionnaires included status of enteral nutrition management of stroke patients (facility, staffing, risk screening, and formulation, implementation and quality control of the plans), nurses' knowledge of enteral nutrition monitoring and complication prevention, follow-up status of enteral nutrition in stroke patients, and nurses' willingness in participating in special training of enteral nutrition.Results:(1) In terms of enteral nutrition facilities and staffing, only 76% and 36% used enteral infusion pumps and heating infusion devices, and only 3% had multidisciplinary team configuration; in terms of risk screening, only 63% had all-patient-screen for enteral nutrition risk; in terms of plan formulation, the proportion of no enteral nutrition process reached to 44%; in terms of plan implementation, the implementation rate of enteral nutrition≤48 h and gastrointestinal function evaluation using gastrointestinal function evaluation scale was less than 50%; in terms of plan quality control, less than 50% Departments had sensitive indexes of enteral nutrition nursing. (2) Among 14 risk management problems of enteral nutrition monitoring and complication prevention, only 3 had accuracy rate higher than 70%. (3) 78% nurses mentioned that patients had experienced enteral nutrition complications, and 77% nurses mentioned that patients/family members had consulted about enteral nutrition related issues; 81% nurses wanted to participate in training or refresher courses related to enteral nutrition, and 88% nurses wanted to join the enteral nutrition Nursing Alliance for stroke patients to serve patients after referral and discharge.Conclusion:The current situation of enteral nutrition management of stroke patients in Guangdong province is not optimistic; nurses lack knowledge of enteral nutrition monitoring and complication prevention, but are strongly willing to participate in the special training of enteral nutrition; relevant measures to further improve the standardized management of enteral nutrition of stroke patients is suggested.

Objective:To explore the molecular mechanisms of a Chinese pedigree with hereditary factor Ⅺ (FⅪ) deficiency.Methods:All of the 15 exons, flanking sequences of the FⅪ gene and the corresponding mutation sites of family members were analyzed by the Sanger sequencing, followed by the extraction of the peripheral blood genomic DNA. And all the results were verified by the reverse sequencing. The conservation of the mutated sites was analyzed by the ClustalX-2.1-win. Three online bioinformatics software tools, including Mutation Taster, PolyPhen2 and the PROVEAN, were used to assess the possible impact of the mutations. Swiss-pdbviewer software was used to analyze the effects of mutant amino acids on protein structure.Results:Genetic analysis revealed that the proband had compound heterozygous mutations including a nonsense mutation of c. 1107C>A (Tyr369stop) in exon 10 and missense mutation of c. 1562A>G (Tyr521Cys) in exon 13. The same c. 1107C>A (Tyr369stop) was present in her father, the same c. 1562A>G (Tyr521Cys) was present in both her mother and daughter. Conservation analysis indicated that Tyr521 was a highly conserved site during evolution. The prediction of pathogenicity showed that both c. 1107C>A and c. 1562A>G were pathogenic mutations. Protein structure prediction showed that in the wild type FⅪ protein structure, Tyr521 formed a hydrogen bond with the Lys572 and Ile388, respectively. When Tyr521 was replaced by Cys521, the original benzene ring structure disappeared, and side chains of Lys572 added a hydrogen bond with the Cys521, which may chang protein catalytic domain structure. When Tyr369 was mutated to a stop codon, resulting in the truncated protein.Conclusion:The compound heterozygous mutations including the c. 1107C>A heterozygous missense variant in exon 10 and the c. 1562A>G heterozygous nonsense mutation in exon 13 may be responsible for the hereditary factor Ⅺ deficiency in this Chinese pedigree.

Objective:To assess the cognition and attitude of vitamin D deficiency among pregnant women.Methods:From December 2021 to February 2022, semi-structured interviews were conducted with 12 pregnant women who visited the Nutrition Clinic in Peking Union Medical College Hospital by using the purposive sampling method.Results:Three themes were extracted, knowledge of vitamin D varies among pregnant women, there were barriers to improving vitamin D nutritional status in pregnant women, and pregnant women wanted more support on vitamin D knowledge from clinicians.Conclusions:Pregnant women lack cognition of vitamin D, and the nutritional status of vitamin D needs to be improved. Medical institutions need to develop evidence-based guidelines for vitamin D management during pregnancy, clinicians need to strengthen the health education for improve the awareness and cognition of vitamin D in pregnant women, and it is necessary to provide a targeted guidance for pregnant women on sunlight exposure, so as to obtain an optimal level of vitamin D.

Objective:To explore the effect of macrophage-derived exosomes on the activation of hepatic stellate cells and its possible mechanism.Methods:Differential ultracentrifugation was used to extract macrophage exosomes. The exosomes were co-cultured with the mouse hepatic stellate cell line JS1, and a control group was established with phosphate buffered saline (PBS). Cell immunofluorescence was used to observe the expressional conditions of F-actin. Cell counting kit-8 (CCK8) was used to detect the survival rate of JS1 cells in the two groups. The activation indices of JS1 cells [collagen type Ⅰ (Col Ⅰ) and α-smooth muscle actin (α-SMA)] and its key signal pathway activation index expression level [transforming growth factor (TGF)-β1/Smads, platelet-derived growth factor (PDGF)] in the two groups were determined using Western blot and RT-PCR. Data comparison between two groups was performed using an independent sample t-test.Results:The membrane structure of exosomes was clearly observed by transmission electron microscopy. The expression of exosome marker proteins CD63 and CD81 was positive, suggesting that exosomes were successfully extracted. Exosomes were co-cultured with JS1 cells. Compared with the PBS control group, there was no statistically significant difference in the proliferation rate of JS1 cells in the exosomes group ( P＞0.05). The expression of F-actin was significantly increased in the exosome group. The mRNA and protein expression levels of α-SMA and ColⅠwere significantly increased in exosome group JS1 cells (all P＜0.05). The mRNA relative expression levels of α-SMA in PBS and exosome group were 0.25±0.07 and 1.43±0.19, respectively, while that of ColⅠ was 1.03±0.04 and 1.57±0.06, respectively. The mRNA and protein expressions of PDGF were significantly increased in exosome group JS1 cells ( P＜0.05). The mRNA relative expression levels of PDGF in the PBS group and exosome group were 0.27±0.04 and 1.65±0.12, respectively. There were no statistically significant differences in the mRNA and protein expressions of TGF-β1, Smad2 and Smad3 between the two groups ( P＞0.05). Conclusion:Macrophage-derived exosomes significantly promote the activation of hepatic stellate cells. JS1 cells may be the underlying mechanism for the up-regulation of PDGF expression.

Objective: To observe the root and root canal morphology of mandibular second molars in Western Guangxi by CBCT, to provide a reference for clinical diagnosis and treatment. Methods: In total, 564 patients′ 1 128 mandibular second molars that satisfy the inclusion criteria were analyzed with a planmecaromexis CBCT machine and its own image analysis software. The patients′ gender, age and ethnic differences in the root and canal morphology and the symmetry of the bilateral root and canal were statistically analyzed. Results: Among the 1 128 mandibular second molars, 662 were the Zhuang ethnic group and 384 were the Han ethnic group, and 82 were other ethnic groups; the double root type and C-shaped root type accounted for a relatively high proportion: 73.94% and 24.47%, respectively. The detection rates of the double root type were higher in males than in females (P < 0.05); the detection rates of the C-shaped root type were higher in females than in males (P <0.05); the root type of the teeth was mainly double-rooted in the Zhuang ethnic group (P<0.01). The incidence of type IV in the mesial root of the double root type mandibular second molar was the highest (P < 0.01), and the incidence of type I in the distal root was the highest (P < 0.01). The C-shaped root canal is more continuous at the mouth of the root canal, more downward corresponds to a worse continuity: in three different levels of root canal orifice, root middle and root apex, the root canal orifice is dominated by the C1 type, and both root middle and root apex are mainly C3-type (P < 0.01). The difference in symmetry of bilateral roots and root canals was statistically significant among different gender groups, age groups, and ethnic groups (P < 0.05): there were more males than females, the results in the 18-35-year-old group and the Zhuang ethnic group were higher. Conclusion The root and root canal morphology of mandibular second molars in western Guangxi people are complex and changeable. The roots are mainly double root type in the Han ethnic group and the Zhuang ethnic group. C-shaped roots are also common. The detection rate of C-shaped roots in the Zhuang ethnic group was higher, and the symmetry rate of bilateral roots and that of bilateral root canals was higher in the Zhuang ethnic group than in the Han ethnic group.

Objective: To study the etiological characteristics of an imported Chikungunya fever (CHIK) epidemic in Fujian province in 2018. Methods: Serum samples collected at different days after the onset of the two CHIK cases were detected by real-time RT-PCR and ELISA. Structural protein E1 gene was amplified by RT-PCR and sequenced for nucleotide characteristics analysis and phylogenetic tree analysis. Results: RNA of Chikungunya virus (CHIKV) was detected in the 4 serum samples collected on the first 5 days of the disease, and the earliest IgM antibodies were detected in specimens on the 5th day of the disease, however, IgG antibodies were only detected in specimen on 10th day. Compared with the S27-African prototype strain, 12 mutant points were found in the amino acids of E1 genes in this study. The E1 genes of the two CHIK cases were exactly the same, and they were closest to the evolutionary relationship with the strain isolated in the Philippines in 2014. Their genotype was Asian genotype. Conclusions This epidemic was confirmed to have been imported from the Philippines after the infection with the Asian genotype CHIKV, which suggests that Fujian province should strengthen the monitoring of persons entering from the CHIK epidemic area, so as to prevent imported cases from causing local outbreaks.

Objective To investigate whether a 3D printed model of the contrlateral healthy distal radius, especially its articular accuracy, helps anatomical reduction and precise reconstruction of the fractured distal radius. Methods The CT data of bilateral radii were collected from 15 normal volunteers ( 11 males and 4 females with an average age of 22. 8 years ) between November and December 2016. After 3D reconstruction of the bilateral distal 1/3 radii, solid 3D models of left radius were mirrored and generated by 3D printing. The data of right radii ( reference group ) were compared with the data of the solid 3D models of left radius acquired through a 3D scanner ( test group ) using deviation analysis. Results The maximum volume difference between the 3D printed model and the contralateral radius was 6. 86％. The average volume of the reference group was 19, 165. 82 ± 3, 250. 50 mm3 and that of the test group 19, 310. 65 ± 3, 305. 15 mm3, showing no statistically significant difference between the 2 groups ( t= -0. 941, P=0. 363 ) . The maximum surface area difference was 3. 84％ between the 2 groups. The average surface area of the reference group was 5, 075. 80 ± 549. 34 mm2 and that of the test group 5, 139. 43 ± 572. 48 mm2, showing a signifi-cant difference ( t= -2. 451, P=0. 028 ) . The 3D deviation analysis showed a mean positive deviation of 0. 37 ± 0. 10 mm and a mean negative deviation of 0. 30 ± 0. 07 mm. The maximum mean square root was 0. 65. The 3D deviation was distributed mainly within 1 mm interval, with a distribution frequency of 96. 27％. Conclusions A 3D printed model prepared by high precision equipment is accurate enough to guide reconstruction of distal radius fractures in adults. In the treatment of complex fractures of the distal radius, a 3D printed model of the contralateral healthy distal radius can be used as a reference to achieve anatomical reduction and precise reconstruction of the fractured distal radius.