Objective To obtain the recombinant Argonaute protein(TtAgo)from Thermus thermophilus using gene cloning and pro-tein purification techniques and detect its endonuclease activity against the KRAS 12D mutation in vitro,thereby to provide experimental evidence for its subsequent application in the detection of gene mutations.Methods The TtAgo gene sequence was amplified from the genome of Thermus thermophilus by the PCR technology.Then,the amplified sequence was inserted into the prokaryotic expression vec-tor pET-28a to construct the recombinant vector pET-28a-TtAgo.After the recombinant TtAgo protein was induced to be expressed,it was purified sequentially by the nickel ion affinity chromatography(Ni-NTA),heparin affinity chromatography,and size-exclusion chromatography.The high-specificity nuclease activity of the recombinant TtAgo protein mediated by a short DNA guide strand(gDNA)was verified in vitro.Results The prokaryotic expression vector pET-28a-TtAgo was successfully constructed by the gene cloning tech-nique,and the soluble expression of the recombinant TtAgo protein was achieved.With the help of protein purification technology,the high-purity recombinant TtAgo protein was obtained.Under the mediation of gDNA,the recombinant TtAgo protein could specifically cleave wild-type single-stranded DNA(ssDNA),double-stranded DNA(dsDNA),and RNA molecules,while had no cleavage activi-ty for tumor KRAS 12D mutant molecules.Conclusion The high-purity recombinant TtAgo protein with nuclease activity is successful-ly obtained,and its targeted cleavage activity towards the KRAS 12D mutation site is detected in vitro.

Objective To obtain the recombinant Argonaute protein(TtAgo)from Thermus thermophilus using gene cloning and pro-tein purification techniques and detect its endonuclease activity against the KRAS 12D mutation in vitro,thereby to provide experimental evidence for its subsequent application in the detection of gene mutations.Methods The TtAgo gene sequence was amplified from the genome of Thermus thermophilus by the PCR technology.Then,the amplified sequence was inserted into the prokaryotic expression vec-tor pET-28a to construct the recombinant vector pET-28a-TtAgo.After the recombinant TtAgo protein was induced to be expressed,it was purified sequentially by the nickel ion affinity chromatography(Ni-NTA),heparin affinity chromatography,and size-exclusion chromatography.The high-specificity nuclease activity of the recombinant TtAgo protein mediated by a short DNA guide strand(gDNA)was verified in vitro.Results The prokaryotic expression vector pET-28a-TtAgo was successfully constructed by the gene cloning tech-nique,and the soluble expression of the recombinant TtAgo protein was achieved.With the help of protein purification technology,the high-purity recombinant TtAgo protein was obtained.Under the mediation of gDNA,the recombinant TtAgo protein could specifically cleave wild-type single-stranded DNA(ssDNA),double-stranded DNA(dsDNA),and RNA molecules,while had no cleavage activi-ty for tumor KRAS 12D mutant molecules.Conclusion The high-purity recombinant TtAgo protein with nuclease activity is successful-ly obtained,and its targeted cleavage activity towards the KRAS 12D mutation site is detected in vitro.

The Xuming Decoction, which is recorded in the "Gu Jin Lu Yan" section of Zhang Zhongjing's Synopsis of the Golden Chamber, is a traditional Chinese medicine formula. Recent literature review and summary of the clinical application research progress have found that this formula is primarily used to treat diseases such as acute cerebral infarction, facial neuritis, multiple sclerosis, Guillain-Barre syndrome, and pulmonary distension. However, different medical practitioners and scholars hold diverse understandings of Xuming Decoction.

Humans ; Data Warehousing ; East Asian People ; Intracranial Hemorrhages/diagnostic imaging* ; Asian People ; Cerebral Hemorrhage/diagnostic imaging*

Objective: : Cranial base chordomas are rare, but their treatment is challenging. Tumor recurrence is still common despite improvements in microsurgical techniques and postoperative radiotherapy. We retrospectively analyzed the course of treatment, overall survival, and recurrence/progression of chordomas over the past 10 years. Methods: : We retrospectively reviewed 50 patients who underwent surgery at Tianjin Huanhu Hospital between 2010 and 2020 and were pathologically diagnosed with chordomas. Tumor resection was performed within the maximum safe range in all patients; the extent of resection was evaluated by imaging; and the incidence of complications, recurrence or progression, and overall survival were assessed. Results: : Fifty patients were divided into the low-risk group (LRG) and high-risk group (HRG) based on the cranial chordoma grading system (CCGS). The Karnofsky Performance Scale scores and gross total resection rate of the LRG were significantly higher than those of the HRG (p<0.05). The incidence of complications and mortality in the LRG were lower than those of HRG. The analysis of cumulative survival and cumulative recurrence free survival/progression free survival (RFS/PFS) showed no statistical differences in the extent of resection for survival, recurrence, or progression. Univariate and multivariate analyses showed that Ki-67 was significantly associated with tumor recurrence and was an independent hazard factor (p=0.02). Conclusion : The CCGS can help neurosurgeons anticipate surgical outcomes. Pathological results are important in evaluating the possibility of tumor recurrence, and postoperative radiotherapy improves overall survival and RFS/PFS.

Objective To establish viral inactivation/removal techniques for blood products , and apply them to inacti-vation/removal process validation of blood products .Methods Enveloped and non-enveloped model viruses were propaga-ted.Viral inactivation/removal techniques for blood products ,including solvent/detergent (S/D) treatment, low pH incuba-tion, dry heat method, pasteurization,and nanofiltration, were established.The virus titer was evaluated using cytopathic effects ( CPE) and Spearman and Karber method .The viral inactivation/removal techniques were believed to be effective when LRV≥4.These techniques were used in viral inactivation /removal validation of blood products .Results Enveloped model viruses were inactivated through S/D treatment and the low pH incubation method .Enveloped and non-enveloped model viruses were inactivated through dry heat and pasteurization .Within a certain range of filtration capacity , PPV was removed through nanofiltration .Conclusion The established viral inactivation/removal techniques can be used in viral inactivation/removal process validation of blood products , which can improve viral safety of blood products .

Objective To explore the changes of gene and protein expressions of nuclear factor-κB(NF-κB) and tumor necrosis factor-α (TNF-α) in immature rats with pilocarpine-induced epilepsy treated with ghrelin. Methods The pllocarpine-induced epilepsy model in immatured rats were built, then the rats were divided into three groups: Ghrelin-treated group, saline-treated group and model group, meanwhile the normal control group was set. The NF-κB and TNF-α levels of gene and protein in the cerebral cortex of immature rats were detected. Results The expression levels of gene and protein of NF-κB and TNF-α were increased in model group,but decreased in the normal control group;NF-κB and TNF-α levels in Ghrelin treated group were obviously lower than those of saline-treated group and model group(P < 0. 05). Conclusion The protective mechanism of Ghrelin for nerve cell is cutting down the expressions of NF-κB and TNF-α in the cerebral cortex of immature rats with epilepsy and lessening inflammatory reaction in neurocytes.

Thirty-seven cases of brain glioma,confirmed by light microscopy and immuno-'histochemistry were studied with transmission electron microscopy.It was found that there were certain ultrastructural features for each type and each grade of glioma.In astrocytoma,there was certain amount of glial filaments in the tumor cells; Rosenthal fibers consisted of irregular osmiophilic masses surrounded with glial filaments,occasionally cytoplasmic annulate lamellae and intranuclear filaments could be seen,and the interstitial capillaries were characteristic.In typical oligodendroglioma,astrocytic processes containing glial filaments were quite present in different amounts.These findings suggest that observation on the ultrastructure of gliomas is of significance to establish the diagnosis,to assess the degree of differentiation,and to identify some rare structures which can reveal the essence of the tumor.In addition,ultrastructural observation is helpful for prognosis.