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Chitosanases represent a class of glycoside hydrolases with high catalytic activity on chitosan but nearly no activity on chitin. Chitosanases can convert high molecular weight chitosan into functional chitooligosaccharides with low molecular weight. In recent years, remarkable progress has been made in the research on chitosanases. This review summarizes and discusses its biochemical properties, crystal structures, catalytic mechanisms, and protein engineering, highlighting the preparation of pure chitooligosaccharides by enzymatic hydrolysis. This review may advance the understandings on the mechanism of chitosanases and promote its industrial applications.
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Quitosano/química , Quitina , Glicósido Hidrolasas/genética , Ingeniería de Proteínas , Oligosacáridos/química , HidrólisisRESUMEN
Lymphoma refers to a group of heterogeneous malignancies originating from the reticuloendothelial and lymphatic systems. The clinical manifestations, treatment strategies, and disease outcomes of different types of lymphoma considerably vary. Recent developments in high-throughput sequencing technologies have enhanced understanding of the pathogenesis and molecular stratification of lymphoma. In the era of new drugs, precise stratification and targeted drug selection can not only improve the prognosis of patients with lymphoma but also reduce the toxic side effects of traditional chemotherapy, ultimately achieving the accurate diagnosis and individualized treatment of tumors. This article reviews the research progress of molecular diagnosis and individualized treatment of different lymphoma subtypes and lymphoma-related research in important meetings such as ASCO, EHA, and ICML in 2023.
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Isoprene emission can lead to significant consequence for atmospheric chemistry. In addition, isoprene is a chemical compound for various industrial applications. In the organisms, isoprene is produced by isoprene synthase that eliminates the pyrophosphate from the dimethylallyl diphosphate. As a key enzyme of isoprene formation, isoprene synthase plays an important role in the process of natural emission and artificial synthesis of isoprene. So far, isoprene synthase has been found in various plants. Isoprene synthases from different sources are of conservative structural and similar biochemical properties. In this review, the biochemical and structural characteristics of isoprene synthases from different sources were compared, the catalytic mechanism of isoprene synthase was discussed, and the perspective application of the enzyme in bioengineering was proposed.
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Objective To investigate the temperature variation within intra-spinal canal and intra-spinal tumor during percutaneous radiofrequency ablation (RFA) procedure for vertebral tumor in experimental rabbits. Methods Eight New Zealand white rabbits were transplanted with VX2 carcinoma in the lumbar vertebral body by percutaneous puncture inoculation technique under CT guidance in order to set up vertebral tumor models. The eight vertebral tumor models were treated with RFA under CT guidance. The temperature within the spinal canal and vertebral tumor of rabbits was measured and recorded every 30 seconds during the RFA treatment. The results were statistically analyzed by paired sampled t text. Results The intra-tumor temperature rose to 90℃ rapidly and remained stable during the whole RFA procedure, whereas the temperature in the spinal canal exceeded 42℃ when treatment time was over three minutes during the procedure. Statistically significant difference in the temperature level during RFA existed between the spinal canal and the vertebral tumor (P < 0.05). Conclusion The temperature in the vertebral tumor of rabbit can quickly reach to the therapeutic level during RFA. Prolonging operative time of RFA may hurt the nerve due to high temperature.
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Objective To preliminarily evaluate the safety and efficacy of percutaneous vertebroplasty (PVP) with 131I-loaded bone cement in treating vertebral tumor in rabbit models. Methods Twelve New Zealand white rabbits with lumbar vertebral tumor, which was established by puncturing transplant of VX2 carcinoma, were randomly and equally divided into the study group and the control group with 6 rabbits in each group. PVP with injection of 131I-loaded bone cement was carried out in the rabbits of the study group, while PVP with injection of pure bone cement was employed in the rabbits of the control group. The blood cell count was determined in all the animals one day before PVP as well as on the 4th day after PVP. PET-CT examination was performed one day before PVP as well as on the 4th day after PVP to check the stand uptake value (SUV) of each vertebral tumor. SPECT was performed in all rabbits of the study group at one, 4 and 8 days after PVP respectively to estimate the distribution of 131I in the animals’ bodies. Eight days after PVP, blood cell counts, which were determined both before and after PVP, existed between the study group and the control group. SPECT that was performed after PVP indicated that 131I was mainly accumulated within PVP-treated vertebrae, and the distribution of 131I showed no obvious changes at different points of time after the procedure. Before PVP, the difference in SUV between the two groups was of no statistical significance (F = 0.765, P > 0.05). In the study group, the postoperative SUV was significantly lower than the preoperative SUV (F = 423.792, P < 0.05). Pathological examination showed that the extent of tumor cell necrosis around the bone cement in the study group was remarkably bigger than that in the control group. Conclusion In treating vertebral tumors with PVP, the use of 131I-loaded bone cement is clinically feasible, and short-term follow-up indicates that this technique is safe and effective.
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Objective To report a case of primary breast T-cell lymphoblastic lymphoma/leukemia (T-LBL/ALL) and study its clinico-pathological features and treatment,to improve the recognition of T-LBL/ ALL.Methods A case of primary breast T-LBL/ALL was reported and reviewed the literatures.Results The female patient was 17 years old,was diagnosed as primary breast T-LBL/ALL who presented with multiple bilateral breast masses and left axillary lymph node enlargement for two months.The patient was treated with modified BFM-90 and achieved complete remission.The patient was in complete remission 12 months after diagnosis at present and till in follow-up.Conclusion Primary breast T-LBL/ALL is very rare and highly aggressive with bad prognosis.T-cell lymphoblastic leukemia chemotherapy regimens is often effective.
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Objective To analyze the efficacy and safety of CT-guided percutaneous injection of the fibrin glue bv double needle technique to treat sacral cyst.Methods Clinical data of 20 cases with double-needle injection of fibrin glue technology to treat sacral cyst were retrospectively analyzed.All patients had varying degrees of sacral nerve root compression symptoms.The treatment for sacral cyst was carried out after clear diagnosis was made.On the basis of CT-guided percutaneous injection of fibrin glue,the improved CT-guided percutaneous injection of fibrin glue by double-needle technique was used to treat these patients.The average dose of fibrin glue was(5.9 ± 2.4)ml.The clinical results of improvement as to pain and neurological function were evaluated after follow-up of an average of 17 months.The assessment criteria were as follows:excellent,complete resolution of signs and symptoms,with the patient returning to his or her regular employment and no recurrence of cysts during 1 year of follow-up,good,symptoms and signs in the legs and perineal region resolved but with persistent pain in the lumbosacral region,which did not interfere with the patient' s regular work (the cysts did not recur for 6 months during follow-up),fair,no improvement in clinical symptoms,but a decrease in cyst size on the imaging study,poor,no improvement in clinical symptoms and no observed changes in cyst size in imaging studies or recurrence.Results Most patients experienced some degree of pain relief and functional improvement after fibrin glue therapy,with most experiencing complete or marked resolution of clinical symptoms.Nine patients reported excellent recovery,8 reported good recovery,2 reported fair recovery,and 1 reported poor recovery.The overall percentage of positive outcomes (excellent and good recovery) was 85％.No serious postoperative complications were discovered.Conclusions CT guided percutaneous injection of the fibrin glue bydouble needle technique to treat sacral cyst is an ideal method.Double needle technique is simple,safe and reliable.