ObjectiveTo prepare a recombinant PETase with a dual-catalytic-triad and to evaluate its efficiency in the biodegradation of polyethylene terephthalate （PET）. MethodsBased on the crystal structure of wild-type PETase， point mutations （T88H/L117D） were introduced via site-directed mutagenesis. The recombinant protein was prepared using prokaryotic expression and chromatography purification techniques. The enzymatic hydrolysis of the mutant PETase was assessed by relatively quantifying the products mono （2-hydroxyethyl） terephthalate （MHET） and terephthalic acid （TPA）. ResultsBoth wild-type and mutant PETases accumulated as inclusion bodies， accounting for approximately 20% of the total bacterial protein. After solubilization in urea， the proteins were eluted at 300 mmol/L imidazole during affinity chromatography purification， with concentrations of 1.824 and 1.833 mg/mL and purities of 83.11% and 84.32%， respectively. Subsequent anion-exchange chromatography yielded highly pure enzymes in the 200 mmol/L NaCl fraction： 2.776 mg/mL （96.86% purity） for the wild type and 1.967 mg/mL （95.13% purity） for the mutant. Following refolding， the final concentrations were 0.484 mg/mL for the wild type and 0.991 mg/mL for the mutant. Hydrolysis assays revealed that the mutant released MHET and TPA at （237.67±17.00）% and （197.33±12.01）% of the wild-type levels， respectively. ConclusionThe T88H/L117D dual-catalytic-triad PETase is successfully prepared and it significantly enhanced PET-degrading activity， thus， it′s a promising biocatalyst for PET bioremediation.

Hepatitis B，an infectious disease caused by the hepatitis B virus（HBV），poses a severe threat to health by inducing acute and chronic hepatitis，cirrhosis，and liver cancer，thereby imposing heavy disease burden and psychological pressure to patients. In 1992，the average positive rate of hepatitis B surface antigen（HBsAg）in China was 9.75%，classifying the country as a high-prevalence area for hepatitis B. Since the mid-1980s，China has implemented a comprehensive prevention and control strategy centered on hepatitis B vaccination for newborns. This strategy encompasses measures such as blocking mother-to-child transmission，blood screening，control of healthcare-associated infections，prevention and control among key populations，and public education and awareness campaigns. After nearly four decades of efforts，the 2020 national hepatitis B seroepidemiological survey revealed a significant decline in China's overall HBsAg positive rate to 5.86%，with the positivity rate among children aged 1-4 years plummeting to just 0.30%. Compared with 1992，they have decreased by 40% and 97% respectively. New HBV infections have significantly decreased，and the prevention and control measures have achieved remarkable economic and social benefits. However，China still confronts numerous challenges in eliminating hepatitis B. The number of chronic HBV carriers remains substantial，and the infection rates among childbearing-age populations and sexually active groups are still relatively high. New infections among adults continue to occur sporadically. Additionally，the vaccination rate for hepatitis B among high-risk adult populations is low，and the newborn immunization program is weak in some areas. The public's awareness of hepatitis B needs to be improved urgently. The rates of detection，diagnosis，and treatment for hepatitis B are relatively low. Moreover，there is currently no effective drug that can completely eliminate HBV. Against the backdrop of rapid advancements in internet and information technologies，as well as in detection and diagnostic methods，China should promptly develop a multi-department prevention and control plan，introduce supportive policies and safeguard measures，and implement a hepatitis B prevention and control strategy that is based on universal immunoprevention and is systematic，comprehensive，standardized，precise，and fully integrated. At the same time，it is essential to improve an information management system，explore the integration of medical care and disease prevention mechanisms，increase financial investment，and implement measures at all stages，including screening，diagnosis，referral，treatment，and care. Additionally，efforts should be made to mobilize the participation of the entire society in order to achieve the goal of eliminating the public health threat of hepatitis B as soon as possible.

Hepatitis B，an infectious disease caused by the hepatitis B virus（HBV），poses a severe threat to health by inducing acute and chronic hepatitis，cirrhosis，and liver cancer，thereby imposing heavy disease burden and psychological pressure to patients. In 1992，the average positive rate of hepatitis B surface antigen（HBsAg）in China was 9.75%，classifying the country as a high-prevalence area for hepatitis B. Since the mid-1980s，China has implemented a comprehensive prevention and control strategy centered on hepatitis B vaccination for newborns. This strategy encompasses measures such as blocking mother-to-child transmission，blood screening，control of healthcare-associated infections，prevention and control among key populations，and public education and awareness campaigns. After nearly four decades of efforts，the 2020 national hepatitis B seroepidemiological survey revealed a significant decline in China's overall HBsAg positive rate to 5.86%，with the positivity rate among children aged 1-4 years plummeting to just 0.30%. Compared with 1992，they have decreased by 40% and 97% respectively. New HBV infections have significantly decreased，and the prevention and control measures have achieved remarkable economic and social benefits. However，China still confronts numerous challenges in eliminating hepatitis B. The number of chronic HBV carriers remains substantial，and the infection rates among childbearing-age populations and sexually active groups are still relatively high. New infections among adults continue to occur sporadically. Additionally，the vaccination rate for hepatitis B among high-risk adult populations is low，and the newborn immunization program is weak in some areas. The public's awareness of hepatitis B needs to be improved urgently. The rates of detection，diagnosis，and treatment for hepatitis B are relatively low. Moreover，there is currently no effective drug that can completely eliminate HBV. Against the backdrop of rapid advancements in internet and information technologies，as well as in detection and diagnostic methods，China should promptly develop a multi-department prevention and control plan，introduce supportive policies and safeguard measures，and implement a hepatitis B prevention and control strategy that is based on universal immunoprevention and is systematic，comprehensive，standardized，precise，and fully integrated. At the same time，it is essential to improve an information management system，explore the integration of medical care and disease prevention mechanisms，increase financial investment，and implement measures at all stages，including screening，diagnosis，referral，treatment，and care. Additionally，efforts should be made to mobilize the participation of the entire society in order to achieve the goal of eliminating the public health threat of hepatitis B as soon as possible.

Objective:To analyze the diagnostic performance of contrast-enhanced ultrasound (CEUS) in the diagnosis of papillary thyroid carcinoma (PTC) and related parameters in the diagnosis of cervical lymph node metastasis.Methods:The clinical data of 130 patients who underwent ultrasonography in Ningbo Hospital of Traditional Chinese Medicine from Jan. 2019 to Jan. 2022 were retrospectively analyzed. All patients received contrast-enhanced ultrasonography and postoperative pathological examination. According to the pathological diagnosis of benign and malignant tumors, they were divided into PTC group and benign nodule group. In the PTC group, there were 46 males and 40 females, aging 51.79±5.01 years old, ranging from 32 to 63 years old; In the nodule group, there were 25 males and 19 females, aging 52.05±4.89 years old, ranging from 33 to 64 years old. According to the presence or absence of cervical LNM, they were divided into a metastasis group of 31 cases, 17 males and 14 females; age (51.69±6.14 years), ranging from 36 to 63 years; 55 cases in the non-transfer group, 29 males and 26 females, aging (51.75±6.18) years, ranging from 36 to 62 years. Comparative analysis of different nodule properties, presence or absence of LNM, different lesion diameters in imaging manifestations and time-intensity curve (time-intensity curve, TIC) parameters differences, measurement data between groups were conducted by independent sample t test, count data between groups were compared by χ2. The receiver operating characteristic curve (receiver operating characteristic, ROC) was drawn to evaluate the diagnostic performance of TIC parameters for cervical LNM. Results:The proportion of PTC nodules with low enhancement, irregular enhancement, heterogeneous enhancement, unclear lesion boundary, and perfusion defect (72.09%, 87.21%, 88.64%, 69.77%, 70.93%) was significantly higher than that of benign nodules (38.64%, 11.36%) %, 27.27%, 77.27%, 27.27%) ( χ2=13.67, 70.75, 49.69, 25.92, 18.24, P<0.05) ; PTC nodule peak intensity (peak intensity, PI), TIC area under the curve (area under curve, AUC) was significantly lower than that of benign nodules (14.86±2.11dB vs 23.94±3.51dB, 985.14±105.31dB·s vs 1621.14±182.61dB·s) ; time to peak (TTP) was significantly higher than that of benign nodules ( 44.82±5.01s vs 36.95±4.18s) ( t=18.39, 21.36, 8.94, P<0.05) ; there was no significant difference in mean transit time (MTT) ( P>0.05) ; AUC was significantly higher than that of the non-metastatic group (16.86±2.09) dB vs (13.73±1.42) dB, (1163.54±131.41) dB·s vs (884.59±93.25) dB·s ( t=8.25, 11.46, P<0.05) ; The PI and AUC of PTC patients with lesion diameter ≤1.5 cm were significantly lower than those of patients with lesion diameter > 1.5 cm (11.56±1.94) dB vs (15.93±2.46) dB, (876.97±100.21) dB·s vs (1020.09±125.41) dB·s ( t=8.39, 5.34, P< 0.05), there was no significant difference in terms of TTP or MTT ( P>0.05) ; the AUC of PI in the diagnosis of cervical lymph node metastasis in PTC patients was 0.888 (95% CI: 0.807-0.969), the sensitivity was 90.91%, and the specificity was 77.42%; The AUC for the diagnosis of cervical lymph node metastasis in PTC patients was 0.972 (95% CI: 0.943-1.000), with a sensitivity of 87.10% and a specificity of 96.36%. Conclusion:The CEUS manifestations of PTC nodules are mostly irregular and heterogeneous low-enhancement, and the TIC-related parameters of PTC nodules and benign nodules are significantly different, and TIC-related parameters have good diagnostic efficiency for patients with cervical lymph node metastasis.

BACKGROUND:The treatment of limbs’ open fracture with severe soft tissue injury is very complicated. There are many wound exudates, high frequency of dressing change, and high infection rate. How to deal with the contradiction between wound treatment and fracture fixation is the considerable problem in clinical therapy. ＜br> OBJECTIVE:To explore the effect of external fixator combined with vacuum sealing drainage on limbs’ open fracture with severe soft tissue injuries. ＜br> METHODS:A total of 34 patients with limbs’ open fracture with severe soft tissue injuries were enrol ed in the First Affiliated Hospital, Xinxiang Medical Col ege from December 2009 to December 2010. There were 20 males and 14 females, with an average age of 36.6 years old. There were 10 cases of upper limb fracture and 24 cases of lower limb fracture. After debridement, cutaneous deficiency accounted for 1%to 6%of surface area. On the basis of external fixation, the wound received vacuum sealing drainage (treatment group;n=17) and conventional dressing (control group;n=17). According to limb swel ing and granulation growth, delayed suture, skin graft or flap to cover the wound were used. After treatment, infection rate of the wound and growth of granulation were observed. In accordance with wound healing and growth of granulation, curative effects were evaluated. ＜br> RESULTS AND CONCLUSION:In the treatment group, there were 11 cases of healing, 5 cases of effective effects, and 1 case of ineffective effect, with a total effective rate of 94%and the infection rate of about 15%. In the control group, there were 7 cases of healing, 6 cases of effective effects, and 4 cases of ineffective effects, with a total effective rate of 76%and the infection rate of about 40%. Significant differences in healing rate, total effective rate and infection rate were detected between the two groups (P＜0.05). The healing time of wound was 8.66-16.23 days in the treatment group and 15.68-22.36 days in the control group. The healing time was significantly shorter in the treatment group than in the control group (P＜0.05). It is thus clear that vacuum sealing drainage has obvious advantages in repair of limbs’ open fracture with severe soft tissue injury compared with the conventional dressing.

OBJECTIVETo downregulate the expression of pituitary tumor transforming gene 1 (PTTG1) in osteosarcoma (OS) cells by siRNA technology and to investigate related biological impact on cell proliferation, cell cycle and cell invasion of OS.

METHODSThree OS cell lines and osteoblast hFOB1.19 cell line were used in this study. Control siRNA and PTTG1 siRNA were employed to transfect OS U2OS cells, and PTTG1 protein level was detected by Western blot after the transfection. Effects of PTTG1 siRNA on cell proliferation, cell cycle and cell invasion were investigated by CCK-8, flow cytometry and Boyden chamber, respectively. Finally, activity of Akt and its downstream target gene expression were analyzed by Western blot in U2OS cells upon various treatments.

RESULTSExpression of PTTG1 protein in 3 OS cells (MG-63, SaOS-2 and U2OS) was significantly higher than that in osteoblast hFOB1.19, among which U2OS cells displayed the highest level. PTTG1 siRNA markedly downregulated the expression of PTTG1 protein in U2OS cells, leading to obvious inhibition of cell proliferation, altered cell cycle distribution and reduced ability of invasion of U2OS cells. Moreover, downregulation of PTTG1 reduced the expression of p-Akt (S473 and T308), MMP-2 and MMP-9 proteins, along with enhanced expression of p21 and E-cadherin proteins.

CONCLUSIONSPTTG1 may be tightly linked to the development of OS and therefore may serve as a novel target for precision therapy of OS.

Bone Neoplasms ; metabolism ; pathology ; Cadherins ; metabolism ; Cell Cycle ; drug effects ; physiology ; Cell Movement ; Cell Proliferation ; drug effects ; physiology ; Down-Regulation ; Humans ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Neoplasm Invasiveness ; Osteosarcoma ; metabolism ; pathology ; RNA, Small Interfering ; pharmacology ; Securin ; genetics ; metabolism ; Transfection

Objective To investigate causes for Kojewnikow syndrome,by observing its clinical characteristics,electroencephalography and findings in imaging scanning. Methods Twelve patients with Kojewnikow syndrome were accessed with clinical observation, electroencephalography and imaging scanning. Results Kojewnikow syndrome is clinically charaterized by secouse twitching and simple partialis motor continua.Viral encephalitis is by far the most of common cause for Kojewnikow syndrome, followed by meningo-encephalitis,cerebral glioma,cerebral cysticercosis, cerebral infarction, diabetes, and cryptogenic epilepsyKojewnikow syndrome tends to occur in watershed area. Conclusions Kojewnikow syndrome falls into two main groups.It is important to improve the diagnosis and find the causes for Kojewnikow and to access its clinical manifestations, electroencephalography and findings in the imaging scanning.The seizures cannot be readily controlled by the anticonvulsants,so the prognosis is poor.