Benzyl isothiocyanate induces cell cycle arrest and apoptosis in cervical cancer through activation of p53 and AMPK-FOXO1a signaling pathways / 中国药理学通报

Aim To investigate the effect of benzyl iso-thiocyanate (BITC) on the proliferation of mouse U14 cervical cancer cells and to explore the mechanism of cytotoxicity based on transcriptomic data analysis. Methods The effect of BITC on U14 cell activity was detected by MTT, nuclear morphological changes were observed by Hochest 33258 and fluorescent inverted microscope, cell cycle and apoptosis were determined by flow cytometry, and the transcriptome database of U14 cells before and after BITC (20 μmol · L

Progress in diagnosis and treatment of hepatic alveolar echinococcosis / 器官移植

Hepatic echinococcosis is a chronic parasitic disease, which is caused by the larvae of Echinococcus multilocularis. It has a high risk of disability and mortality, which is also known as "parasite cancer". In clinical practice, hepatic echinococcosis can be divided into hepatic alveolar echinococcosis and hepatic cystic echinococcosis. Hepatic echinococcosis is widely prevalent worldwide. It mainly occurs in the populations residing agricultural and pastoral areas in western China, posing significant threats to the quality of life of local residents. At present, surgery is the main treatment for hepatic echinococcosis in clinical settings. With rapid development of surgical diagnosis and treatment technology and deepening understanding of hepatic echinococcosis, diagnosis and treatment regimens have also been constantly improved. In this article, research progresses on the diagnosis and treatment of hepatic alveolar echinococcosis were reviewed, aiming to provide reference for clinicians, deliver early diagnosis and treatment, mitigate adverse effects of this disease upon patients and improve clinical prognosis.

Possible Risk Factors for Bone Marrow Fibroplasia in Patients with Polycythemia Vera / 中国实验血液学杂志

OBJECTIVE@#To understand the biological characteristics of polycythemia vera (PV) patients with myeloid fibroplasia, and further analyze the risk factors affecting myeloid fibroplasia in PV patients, so as to provide ideas for predicting the occurrence of myeloid fibroplasia in PV patients.@*METHODS@#Forty patients with PV in the Department of Hematology, Xiyuan Hospital of China Academy of Chinese Medical Sciences were collected and divided into two groups, with (hyperplasia group) and without (Non-proliferative group) hyperplasia of bone marrow fibers. The differences of basic clinical characteristics, blood routine, biochemistry, bone marrow cells, coagulation function and other indicators between the two groups were compared, and the independent risk factors affecting the proliferation of bone marrow fibrous tissue in PV patients were further analyzed by multivariate regression.@*RESULTS@#Compared with Non-proliferative group, the JAK2 mutation rate (95% vs 70%，P=0.037), eosinophilic cell count (0.19 vs 0.11, P=0.047) and eosinophilic percentage (1.84 vs 1.27, P=0.001) in PV patients with hyperplasia were significantly increased, triglycerides (1.55 vs 1.91, P=0.038) and low-density lipoprotein (1.50 vs 3.08, P=0.000) were significantly reduced, bone marrow hematopoietic volume (0.85 vs 0.6, P=0.001), granulocyte/erythrocyte ratio (3.40 vs 1.89, P=0.033), lymphocyte/erythrocyte ratio (0.60 vs 0.42, P=0.033), and granulocyte+lymphocyte/erythrocyte ratio (3.72 vs 2.37, P=0.026) were significantly increased, thrombin time (18.84 vs 18.12, P=0.043) was significantly prolonged. Multivariate regression analysis results showed that peripheral blood eosinophil ≥2% and low-density lipoprotein ≤2 mmol/L were independent risk factors for bone marrow fibrous tissue hyperplasia in PV patients (P<0.05).@*CONCLUSION@#Increased proportion of peripheral blood eosinophils and decreased low density lipoprotein are risk factors for bone marrow fibrous tissue hyperplasia in PV patients.

Meta-analysis of obesity on the outcome of rotator cuff repair / 中国骨伤

OBJECTIVE@#To systematically evaluate obesity on the outcome of rotator cuff repair.@*METHODS@#Literatures on the relationship between obesity and outcomes after rotator cuff repair were searched from PubMed, Embase, Cochrane Library, Web of Science, China biology medicine(CBM), CNKI, Wanfang and VIP databases from building database to August 1, 2022, and were screened independently by two authors according to inclusion and exclusion criteria. Endnote X9 and Excel 2019 were used for literature extraction, management and data entry, and Newcastle-Ottawa Scale (NOS) was used to evaluate quality of the included literatures. STATA 16.0 and RevMan 5.4 softwares were used to evaluate postoperative retear rate, reoperation rate, complication rate, American Shoulder and Elbow Surgeons (ASES) score, visual analogue scale (VAS), operative time and external rotation angle of shoulder joint pain were analyzed.@*RESULTS@#Totally 13 literatures were included, including 6 retrospective studies, 5 case-control studies, 1 prospective cohort study, and 1 abstract of a study for which the full text was not available, with 85 503 patients (31 973 in obese group and 53 530 in non-obese group). Meta-analysis showed there were statistical differences between two groups in retear rate [OR=2.58, 95%CI(1.23, 5.41), P=0.01], reoperation rate[OR=1.31, 95%CI(1.21, 1.42), P<0.00], complication rate [OR=1.57, 95%CI(1.31, 1.87), P=0.00], ASES score[MD=-3.59, 95%CI(-5.45, -1.74), P=0.00], and VAS[MD=0.24, 95%CI(0.00, 0.49), P=0.05]. While there were no differences between two groups in operative time[MD=6.03, 95%CI(-7.63, 19.69), P=0.39], external rotation angle of shoulder joint[MD=-1.79, 95%CI(-5.30, 1.71), P=0.32].@*CONCLUSION@#Obesity is associated with higher rates of retear, resurgery, complications, poorer shoulder function and pain after rotator cuff repair.

Augmenting locking plate with autologous bone graft for the treatment of nonunion of long bone fracture in the lower extremity with retaining of the original intramedullary nail / 中国骨伤

OBJECTIVE@#To explore clinical effect of attaching locking plate with bone grafting based on retaining the original intramedullary nail in treating non-union after intramedullary nail fixation of long shaft fractures of lower limbs.@*METHODS@#A retrospective study was conducted on 20 patients treated with non-union fractures after intramedullary nailing of long shaft fractures of lower limbs from June 2015 to June 2020. All patients were treated with the original intramedullary nailing and bone grafting from the iliac bone, and were underwent open reduction plate internal fixation and bone grafting for old fractures. Among them, 14 were males and 6 were females, aged from 35 to 56 years old with an average of (42.2±9.6) years old. Nine patients were femoral shaft fracture and 11 patients were tibial shaft fracture. According to characteristics of fracture end nonunion, 6 patients were stable/atrophic, 9 patients were unstable/large, and 5 patients were unstable/atrophic. The nonunion time ranged from 8 to 12 months with an average of(9.8±2.0) months after the initial surgery. Visual analogue scale (VAS), knee range of motion, bone healing time, complications and fracture-end healing were recorded before and at the latest follow-up.@*RESULTS@#All patients were followed up for 18 to 48 months with an average of (36.3±10.5) months. The incision of all patients were healed at stageⅠwithout complications such as infection or internal fixation ruptur. Healing time of femur and tibia was (8.5±2.6) months and (9.5±2.2) months. Knee joint motion increased from preoperative (101.05±8.98) ° to postoperative (139.35±8.78) ° at the latest follow-up (t=-12.845, P<0.001). VAS decreased from preoperative (5.15±1.72) to postoperative (0.75±0.96) at the latest follow-up (t=11.186, P<0.001).@*CONCLUSION@#On the basis of retaining the original intramedullary nail, the addition of locking plate internal fixation and autogenous iliac bone grafting have advantages of simple operation, less trauma, fewer complications and high fracture healing rate. It is one of the effective surgical schemes for the treatment of nonunion after intramedullary nail fixation of long bone fracture of lower extremity.

Research progress of caput femoris posterior tilt and its impact on prognosis in nondisplaced femoral neck fractures / 中国骨伤

There are still many unresolved problems in the treatment and prognosis of nondisplaced femoral neck fractures, such as nonunion and avascular necrosis of the caput femoris .In order to reduce the risk of various complications after non-displaced femoral neck fractures, the caput femoris posterior tilt of femoral neck fractures and its impact on prognosis have attracted more and more attention. A large number of scholars' studies have found that when the posterior tilt exceeds 20°, the risk of internal fixation failure increases significantly. Based on this concept, we can choose to use primary artificial joint replacement instead of three-screw internal fixation according to the different posterior tilt angles of patients to reduce the incidence of postoperative complications. At the same time, our analysis found that comminution of the posterior segment of the femoral neck would lead to an increase in the posterior inclination angles. The purpose of this review was to investigate the relationship between caput femoris posterior tilt of femoral neck fractures and surgical outcome, and to introduce a new method for measuring caput femoris posterior tilt of the femoral neck.

Expert Consensus on Acute Respiratory Failure in Critically Ill Cancer Patients (2023) / 中国医学科学杂志(英文版)

Objective This consensus aims to provide evidence-based recommendations on common questions in the diagnosis and treatment of acute respiratory failure (ARF) for critically ill cancer patients.Methods We developed six clinical questions using the PICO (Population, Intervention, Comparison, and Outcome) principle in diagnosis and treatment for critical ill cancer patients with ARF. Based on literature searching and meta-analyses, recommendations were devised. The GRADE (Grading of Recommendation Assessment, Development and Evaluation) method was applied to each question to reach consensus in the expert panel. Results The panel makes strong recommendations in favor of (1) metagenomic next-generation sequencing (mNGS) tests may aid clinicians in rapid diagnosis in critically ill cancer patients suspected of pulmonary infections; (2) extracorporeal membrane oxygenation (ECMO) therapy should not be used as a routine rescue therapy for acute respiratory distress syndrome in critically ill cancer patients but may benefit highly selected patients after multi-disciplinary consultations; (3) cancer patients who have received immune checkpoint inhibitor therapy have an increased incidence of pneumonitis compared with standard chemotherapy; (4) critically ill cancer patients who are on invasive mechanical ventilation and estimated to be extubated after 14 days may benefit from early tracheotomy; and (5) high-flow nasal oxygen and noninvasive ventilation therapy can be used as a first-line oxygen strategy for critically ill cancer patients with ARFs. A weak recommendation is: (6) for critically ill cancer patients with ARF caused by tumor compression, urgent chemotherapy may be considered as a rescue therapy only in patients determined to be potentially sensitive to the anticancer therapy after multidisciplinary consultations. Conclusions The recommendations based on the available evidence can guide diagnosis and treatment in critically ill cancer patients with acute respiratory failure and improve outcomes.

Application of photoplethysmography for atrial fibrillation in early warning, diagnosis and integrated management / 生物医学工程学杂志

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Early diagnosis and effective management are important to reduce atrial fibrillation-related adverse events. Photoplethysmography (PPG) is often used to assist wearables for continuous electrocardiograph monitoring, which shows its unique value. The development of PPG has provided an innovative solution to AF management. Serial studies of mobile health technology for improving screening and optimized integrated care in atrial fibrillation have explored the application of PPG in screening, diagnosing, early warning, and integrated management in patients with AF. This review summarizes the latest progress of PPG analysis based on artificial intelligence technology and mobile health in AF field in recent years, as well as the limitations of current research and the focus of future research.

A new allo-aromadendrane sesquiterpene from Dendrobium nobile / 中国中药杂志

To study the chemical constituents in the non-alkaloid part of stems of Dendrobium nobile. The macroporous adsorption resin, MCI, silica gel, RP-C_(18), and Sephadex LH-20 gel, preparative thin layer chromatography, and preparative high-performance liquid chromatography(HPLC) were used to isolate and purify the compounds. The structures of the compound were determined according to the spectra data, physicochemical properties, and relevant references. A total of 8 compounds were isolated from D. nobile, which were soltorvum F(1), p-hydroxyphenylpropionic acid(2), vanillic acid(3), p-hydroxybenzoic acid(4), N-trans-cinnamic acid acyl-p-hydroxybenzene ethylamine(5),(+)-(1R,2S,3R,4S,5R,6S,9R)-2,11,12-trihydroxypicrotoxane-3(15)-lactone(6), dendronobilin H(7), soltorvum E(8). Compound 1 was a novel compound, named as soltorvum F. Compound 8 was isolated from Dendrobium species for the first time.

Component profile analysis of Sanhan Huashi Formula based on UHPLC-LTQ-Orbitrap-MS, GC-MS, and UHPLC-QQQ-MS/MS / 中国中药杂志

This study comprehensively analyzed the active components of Sanhan Huashi Formula using qualitative and quantitative mass spectrometry techniques, laying the foundation for understanding its pharmacological substance basis. UHPLC-LTQ-Orbitrap-MS and GC-MS technologies were used to analyze and identify the volatile and non-volatile components in Sanhan Huashi Formula. UHPLC-QQQ-MS/MS technology was used to simultaneously determine the content of 27 major active components in the formula. The results showed that 308 major chemical components were identified in Sanhan Huashi Formula, among which 60 compounds were identified by comparing with reference standards, mainly including alkaloids, flavonoids, coumarins, triterpenoid saponins, amino acids, and nucleosides. GC-MS technology preliminarily identified 52 volatile compounds, with γ-eudesmol and β-eudesmol as the main components. The quantitative results demonstrated good linearity(r>0.99) for the 27 active components, indicating the stability, simplicity, and reliability of the established method. Among them, amygdalin, nodakenin, arecoline, ephedrine, and pseudoephedrine had relatively high content and were presumably the main pharmacologically active substances. In conclusion, this study systematically and comprehensively characterized the major chemical components and patterns in Sanhan Huashi Formula, providing a basis for understanding its pharmacological mechanisms and clinical applications.

Effect of Suanzaoren Decoction on expression of ionotropic glutamate receptors and synaptic plasticity in hippocampus of anxiety rats / 中国中药杂志

This study investigated the effect of Suanzaoren Decoction on the expression of N-methyl-D-aspartate receptors(NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors(AMPAR) in the hippocampus and synaptic plasticity in rats with conditioned fear-induced anxiety. The effect of Suanzaoren Decoction on rat behaviors were evaluated through open field experiment, elevated plus maze experiment, and light/dark box experiment. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of glutamate(Glu) and γ-aminobutyric acid(GABA) in the rat hippocampus. Real-time fluorescence quantitative PCR(qRT-PCR) and Western blot were employed to assess the gene and protein expression of ionotropic glutamate receptors in the hippocampal region. Transmission electron microscopy was utilized to observe the changes in the ultrastructure of synaptic neurons in the hippocampal region. Long-term potentiation(LTP) detection technique was employed to record the changes in population spike(PS) amplitude in the hippocampal region of mice in each group. The behavioral results showed that compared with the model group, the Suanzaoren Decoction group effectively increased the number of entries into open arms, time spent in open arms, percentage of time spent in open arms out of total movement time, number of entries into open arms out of total entries into both arms(P<0.01), and significantly increased the time spent in the light box and the number of shuttle crossings(P<0.01). There was an increasing trend in the number of grid crossings, entries into the center grid, and time spent in the center grid, indicating a significant anxiolytic effect. ELISA results showed that compared with the model group, the Suanzaoren Decoction group exhibited significantly reduced levels of Glu, Glu/GABA ratio(P<0.01), and significantly increased levels of GABA(P<0.01) in the rat hippocampus. Furthermore, Suanzaoren Decoction significantly decreased the gene and protein expression of NMDAR(GluN2B and GluN2A) and AMPAR(GluA1 and GluA2) compared with the model group. Transmission electron microscopy results demonstrated improvements in synapses, neuronal cells, and organelles in the hippocampal region of the Suanzaoren Decoction group compared with the model group. LTP detection results showed a significant increase in the PS amplitude changes in the hippocampal region of Suanzaoren Decoction group from 5 to 35 min compared with the model group(P<0.05, P<0.01). In conclusion, Suanzaoren Decoction exhibits significant anxiolytic effects, which may be attributed to the reduction in NMDAR and AMPAR expression levels and the improvement of synaptic plasticity.

Clinical application of ArcScan Insight 100 very high-frequency digital ultrasound scanner in ophthalmology / 国际眼科杂志(Guoji Yanke Zazhi)

ArcScan Insight 100 very high-frequency(VHF)digital ultrasound scanner is a new ocular ultrasonic measuring instrument, which can detect and measure the anterior segment. It can be used for screening before corneal refractive surgery and follow-up after corneal refractive surgery, measuring anterior segment parameters before implantable collamer lens(ICL)implantation, predicting preoperative vault, measuring postoperative vault, early screening keratoconus, and diagnosing glaucoma, cataract and eye injuries, etc. Taking the advantages of a wide range examination of ultrasound biomicroscope(UBM)and simple operation of optical coherence tomography(OCT), it has a broad prospect for clinical application. In this paper, the measurement principle, application method, parameters and clinical application progress of ArcScan Insight 100 VHF digital ultrasound scanner are reviewed in detail.

Prevalence and risk factors of dry eye patients with corneal epithelial defects: A hospital-based retrospective study / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To analyze the characteristics and correlated risk factors of dry eye patients with corneal epithelial defects.METHODS: Outpatient medical records of dry eye patients with corneal epithelial defects at Peking University Third Hospital from July 2018 to June 2019 were retrospectively analyzed. The patients' data including sex, age, visit date, presence of comorbidities, and meteorological indicators at the same period were statistically analyzed.RESULTS: A total of 291 dry eye patients with corneal epithelial defects, of whom 75.3% were female, were retrospectively analyzed. Young patients aged 21-30 made up the most(26.5%), while the proportion of teenagers(<18 years, 5.8%)and the elderly(≥61 years, 17.2%)was low. However, as the largest proportion of this population, young and middle-aged patients tend to experience fewer visits(5.4±12.4). Spring and winter were the main seasons of complaints. The meteorological indicators at the same period including fine-particulate matter with a median aerometric diameter of less than 10μm(PM10), sulfur dioxide(SO2), nitrogen dioxide(NO2), and reduced average relative humidity were found significantly correlated with dry eye corneal epithelial defects(P<0.05). Conjunctivitis, cataracts, blurred vision, and trichiasis ranked the top four comorbidities.CONCLUSION: Dry eye corneal epithelial defects of young and female population cannot be ignored. PM10, SO2, NO2, and reduced humidity are found significantly correlated with dry eye corneal epithelial defects. For dry eye patients with conjunctivitis, cataracts, blurred vision, and trichiasis, more attention should be paid to their corneal conditions.

Optical genome mapping analysis of a Chinese pedigree with a rare chromosome 17 paracentric inversion insertion / 中华医学遗传学杂志

OBJECTIVE@#To carry out optical genome mapping (OGM) for a Chinese pedigree with a rare paracentric reverse insertion of chromosome 17.@*METHODS@#A high-risk pregnant woman identified at the Prenatal Diagnosis Center of Hangzhou Women's Hospital in October 2021 and her family members were selected as the study subjects. Chromosome G banding analysis, fluorescence in situ hybridization (FISH), single nucleotide polymorphism array (SNP array) and OGM were applied to verify the balanced structural abnormality of chromosome 17 in the pedigree.@*RESULTS@#Chromosomal karyotyping analysis and SNP array assay have identified a duplication of 17q23q25 in the fetus. Karyotyping analysis of the pregnant woman showed that the structure of chromosome 17 was abnormal, whilst SNP array has detected no abnormality. OGM revealed that the woman has carried a paracentric reverse insertion, which was confirmed by FISH. The karyotype of her husband was normal.@*CONCLUSION@#The duplication of 17q23q25 in the fetus has derived from a paracentric reverse insertion of chromosome 17 in its mother. OGM has the advantage for delineating balanced chromosome structural abnormalities.

Meta-analysis of the effect of hollow nail and bone plate on Lisfranc injury / 中国骨伤

OBJECTIVE@#To compare the clinical efficacy of screw and bone plate internal fixation in the treatment of Lisfranc injury.@*METHODS@#The databases of Wanfang, CNKI, Pubmed, EMBASE, VIP, BIOSIS and other databases were retrieved by computer, and the clinical trial literature from January 1, 2000 to August 1, 2021 was retrieved, the methodological quality of the included studies was strictly evaluated and the data were extracted, and the obtained data were meta-analyzed by Revman 5.4 software.@*RESULTS@#Nine randomized controlled trial literature and 10 retrospective cohort studies were included, of which 416 patients in the experimental group were treated with screw internal fixation, and 435 patients in the control group were treated with bone plate internal fixation. Meta-analysis showed that the surgical time of the bone plate internal fixation group was longer than that of the screw internal fixation group [MD=-14.40, 95%CI(-17.21, -11.60), P<0.000 01], the postoperative X-ray anatomical reduction of the bone plate internal fixation group [MD=0.47, 95%CI(0.25, 0.86), P=0.01], the excellent and good rate of postoperative American orthopedic foot and ankle society(AOFAS) foot function score[MD=0.25, 95%CI(0.15, 0.42), P<0.000 01], postoperative AOFAS foot function score [MD=-5.51, 95%CI(-10.10, -0.92), P=0.02] of the bone plate fixation group was better than those of the screw internal fixation group. Two kinds of operation method had no statistical different for postoperative fracture healing time[MD=1.91, 95%CI(-1.36, 5.18), P=0.25], postoperative visual analgue scale(VAS)[MD=0.38, 95%CI(0.09, 0.86), P=0.11], postoperative complications [MD=1.32, 95%CI(0.73, 2.40), P=0.36], the postoperative infection [MD=0.84, 95%CI(0.48, 1.46), P=0.53], the postoperative fracture internal fixation loosening [MD=1.25, 95% CI(0.61, 2.53), P=0.54], the postoperative incidence of traumatic arthritis [MD=1.80, 95%CI(0.83, 3.91), P=0.14].@*CONCLUSION@#Bone plate fixation has better short-term and medium-term results and lower reoperation rate in the treatment of Lisfranc injury, so it is recommended to use bone plate fixation in the treatment of Lisfranc injury.

Research progress of optical motion capture technology in shoulder biomechanics / 中国骨伤

The shoulder joint is the most flexible joint in the body with the largest range of motion, and the movement pattern is more complex. Accurate capture of three-dimensional motion data of the shoulder joint is crucial for biomechanical evaluation. Optical motion capture systems offer a non-invasive and radiation-free method to capture shoulder joint motion data during complex movements, enabling further biomechanical analysis of the shoulder joint. This review provides a comprehensive overview of optical motion capture technology in the context of shoulder joint movement, including measurement principles, data processing methods to reduce artifacts from skin and soft tissues, factors influencing measurement results, and applications in shoulder joint disorders.

Component identification and analysis in vivo of Sanhan Huashi formula / 中国中药杂志

Sanhan Huashi formula(SHF) is the intermediate of a newly approved traditional Chinese medicine(TCM) Sanhan Huashi Granules for the treatment of COVID-19 infection. The chemical composition of SHF is complex since it contains 20 single herbal medicines. In this study, UHPLC-Orbitrap Exploris 240 was used to identify the chemical components in SHF and in rat plasma, lung and feces after oral administration of SHF, and heat map was plotted for characterizing the distribution of the chemical components. Chromatographic separation was conducted on a Waters ACQUITY UPLC BEH C_(18)(2.1 mm×100 mm, 1.7 μm) using 0.1% formic acid(A)-acetonitrile(B) as mobile phases in a gradient elution. Electrospray ionization(ESI) source was used to acquire data in positive and negative mode. By reference to quasi-molecular ions and MS/MS fragment ions and in combination with MS spectra of reference substances and compound information in literature reports, 80 components were identified in SHF, including 14 flavonoids, 13 coumarins, 5 lignans, 12 amino-compounds, 6 terpenes and 30 other compounds; 40 chemical components were identified in rat plasma, 27 in lung and 56 in feces. Component identification and characterization of SHF in vitro and in vivo lay foundations for disclosure of its pharmacodynamic substances and elucidation of the scientific connotation.

Engineering the plastic degradation enzyme Ple629 from marine consortium to improve its thermal stability / 生物工程学报

Petrochemical-derived polyester plastics such as polyethylene terephthalate (PET) and polybutylene adipate terephthalate (PBAT) have been widely used. However, the difficulty to be degraded in nature (PET) or the long biodegradation cycle (PBAT) resulted in serious environmental pollution. In this connection, treating these plastic wastes properly becomes one of the challenges of environment protection. From the perspective of circular economy, biologically depolymerizing the waste of polyester plastics and reusing the depolymerized products is one of the most promising directions. Recent years have seen many reports on polyester plastics degrading organisms and enzymes. Highly efficient degrading enzymes, especially those with better thermal stability, will be conducive to their application. The mesophilic plastic-degrading enzyme Ple629 from the marine microbial metagenome is capable of degrading PET and PBAT at room temperature, but it cannot tolerate high temperature, which hampers its potential application. On the basis of the three-dimensional structure of Ple629 obtained from our previous study, we identified some sites which might be important for its thermal stability by structural comparison and mutation energy analysis. We carried out transformation design, and performed expression, purification and thermal stability determination of the mutants. The melting temperature (Tm) values of mutants V80C and D226C/S281C were increased by 5.2 ℃ and 6.9 ℃, respectively, and the activity of mutant D226C/S281C was also increased by 1.5 times compared with that of the wild-type enzyme. These results provide useful information for future engineering and application of Ple629 in polyester plastic degradation.

Expression, purification and characterization of a novel bis (hydroxyethyl) terephthalate hydrolase from Hydrogenobacter thermophilus / 生物工程学报

PET (polyethylene terephthalate) is one of the most important petrochemicals that is widely used in mineral water bottles, food and beverage packaging and textile industry. Because of its stability under environmental conditions, the massive amount of PET wastes caused serious environmental pollution. The use of enzymes to depolymerize PET wastes and upcycling is one of the important directions for plastics pollution control, among which the key is the depolymerization efficiency of PET by PET hydrolase. BHET (bis(hydroxyethyl) terephthalate) is the main intermediate of PET hydrolysis, its accumulation can hinder the degradation efficiency of PET hydrolase significantly, and the synergistic use of PET hydrolase and BHET hydrolase can improve the PET hydrolysis efficiency. In this study, a dienolactone hydrolase from Hydrogenobacter thermophilus which can degrade BHET (HtBHETase) was identified. After heterologous expression in Escherichia coli and purification, the enzymatic properties of HtBHETase were studied. HtBHETase shows higher catalytic activity towards esters with short carbon chains such as p-nitrophenol acetate. The optimal pH and temperature of the reaction with BHET were 5.0 and 55 ℃, respectively. HtBHETase exhibited excellent thermostability, and retained over 80% residual activity after treatment at 80 ℃ for 1 hour. These results indicate that HtBHETase has potential in biological PET depolymerization, which may facilitate the enzymatic degradation of PET.

Status and challenges of neoadjuvant immunotherapy for hepatocellular carcinoma / 中华外科杂志

With the development of modern liver surgical techniques and the progress of perioperative management,the survival rate after resection of hepatocellular carcinoma has been greatly improved,but the high recurrence and metastasis rate still limits the long-term survival after surgery. Preoperative neoadjuvant therapy has been confirmed to significantly reduce the postoperative recurrence rate and prolong survival in other types of cancer,but there has been a lack of effective systemic therapy for hepatocellular carcinoma for a long time,so the efficacy and regimen of neoadjuvant therapy for hepatocellular carcinoma are still controversial. PD-1/PD-L1 monoclonal antibody combined with anti-angiogenic targeted drugs has become a first-line regimen in systemic therapy for advanced hepatocellular carcinoma. This regimen has definite efficacy and high safety,bringing hope for neoadjuvant therapy of hepatocellular carcinoma. Recently,three clinical trials of neoadjuvant immunotherapy for hepatocellular carcinoma have been published internationally,which preliminarily suggest the efficacy and safety of neoadjuvant immunotherapy for hepatocellular carcinoma and lay a solid foundation for carrying out larger sample clinical studies in the future.