Enzyme ancestral sequence reconstruction and directed evolution / 生物工程学报

The amino acid sequence of ancestral enzymes from extinct organisms can be deduced through in silico approach termed ancestral sequence reconstruction (ASR). ASR usually has six steps, which are the collection of nucleic acid/amino acid sequences of modern enzymes, multiple sequence alignment, phylogenetic tree construction, computational deduction of ancestral enzyme sequence, gene cloning, and characterization of enzyme properties. This method is widely used to study the adaptation and evolution mechanism of molecules to the changing environmental conditions on planetary time scale. As enzymes play key roles in biocatalysis, this method has become a powerful method for studying the relationship among the sequence, structure, and function of enzymes. Notably, most of the ancestral enzymes show better temperature stability and mutation stability, making them ideal protein scaffolds for further directed evolution. This article summarizes the computer algorithms, applications, and commonly used computer software of ASR, and discusses the potential application in directed evolution of enzymes.

Significance of multiple indexes of fine needle aspiration eluent in the identification of benign and malignant cervical nodules / 中国医师进修杂志

Objective:To explore the identification value of carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC-Ag), cytokeratin 19 fragment (Cyfra211), thyroglobulin (TG), ferritin (Fer) and procalcitonin (PCT) in fine needle aspiration eluent in benign and malignant cervical nodules, and acquire the optimal diagnostic model.Methods:Three hundred and ninety-six single cervical nodule patients who underwent fine needle aspiration biopsy from August 2017 to August 2019 in the Center Hospital of Xiaogan City of Hubei Province were selected. The fine needle aspiration eluent levels of CEA, SCC-Ag, Cyfra211, TG, Fer and PCT were detected by electrogenerated chemiluminescence method. The results of cytopathological diagnosis were regard as "gold standard", and the diagnostic efficiency of single and combined indexes in fine needle aspiration eluent were analyzed by receiver operating characteristic (ROC) curve.Results:Among the 396 patients, malignant nodules was in 101 cases, and benign nodules was in 295 cases. The fine needle aspiration eluent levels of CEA, SCC-Ag, Cyfra211, TG and Fer in patients with malignant nodules were significantly higher than those in patients with benign nodules: (27.73 ± 10.63) μg/L vs. (16.81 ± 8.18) μg/L, (1.59 ± 0.74) μg/L vs. (1.09 ± 0.83) μg/L, (3.31 ± 1.48) μg/L vs. (1.66 ± 0.59) μg/L, (144.96 ± 38.93) μg/L vs. (95.03 ± 47.23) μg/L and (191.18 ± 80.13) μg/L vs. (137.87 ± 63.22) μg/L, the PCT was significantly lower than that in patients with benign nodules: (0.61 ± 0.24) μg/L vs. (1.01 ± 0.52) μg/L, and there were statistical differences ( P<0.01). The ROC curve analysis result showed that the CEA, Cyfra211 and TG had super diagnostic value (area under curve>0.7, Youden index>0.5); the area under curve of CEA, Cyfra211 combined with TG was significantly higher than other combined detection of 2 indexes ( P<0.05). Conclusions:The combined detection of CEA, Cyfra211 and TG in fine needle aspiration eluent can effectively distinguish the benign and malignant cervical nodules.

Evaluation of regulational function of ingredients from hot herbs on TRPV1 channel based on 7900 PCR instrument / 中国药理学通报

Aim To further study the molecular mecha-nism of the herbs with hot nature on the regulational action on TRPV1 channel based on the 7900 Real-time PCR instrument. Methods 7900 PCR instrument was applied to detect the intracellular flurescence of TRPV1 channel in the dorsal root ganglions ( DRG ) neurons and the effect on the TRPV1 ’ s thermo-sensational functions of the selected 11 ingredients from hot herbs was explored. Results TRPV1 channels could be ac-tivated by gradually elevated temperature; the activa-tion process could be blocked by the TRPV1 specific blocking agent capsaizepine. Most of the ingredients from hot-nature herbs had the potential to up-regualate TRPV1 channel function. Conclusions The estab-lished TRPV1 channel detection system based on PCR instrument is suitable for the analysis of regulational functions of drugs on the heat-activated TRPV1 chan-nel;the functions of hot herbs may be related to the up-regualtional effects of its active ingredients on the TRPV1 channel which will further up-regulate energy metabolism.

Construction and preliminary functional study of heterologous expression system of TRPV1 channel / 中国药理学通报

Aim The TRPV1 plasmid was transiently transfected into human embryonic kidney HEK 293T cells to establish the heterologous expression system of TRPV1-channel. Methods The transfection efficiency was confirmed under fluorescence mi-croscope and the TRPV1 protein expression was identified by u-sing Western blot, and the functional characteristics of the chan-nel were studied by using the method of confocal microscopy. Results The transfection rate could reach 40% ~50%; the transfected cells were found to have a clear band at the corre-sponding position that TRPV1 should be, which indicated that TRPV1 channel protein was expressed in the transfected cells. The confocal microscopy imaging result showed that the trans-fected HEK 293T cells were activated by TRPV1 channel ago-nist. Conclusion Transient transfection of HEK 293T cells with TRPV1 channel is successfully constructed and the heterol-ogous TRPV1 channel is verified to have normal calcium-media-ting function.

Evaluation of the Accuracy and Precision of a Next Generation Computer-Assisted Surgical System

BACKGROUND: Computer-assisted orthopaedic surgery (CAOS) improves accuracy and reduces outliers in total knee arthroplasty (TKA). However, during the evaluation of CAOS systems, the error generated by the guidance system (hardware and software) has been generally overlooked. Limited information is available on the accuracy and precision of specific CAOS systems with regard to intraoperative final resection measurements. The purpose of this study was to assess the accuracy and precision of a next generation CAOS system and investigate the impact of extra-articular deformity on the system-level errors generated during intraoperative resection measurement. METHODS: TKA surgeries were performed on twenty-eight artificial knee inserts with various types of extra-articular deformity (12 neutral, 12 varus, and 4 valgus). Surgical resection parameters (resection depths and alignment angles) were compared between postoperative three-dimensional (3D) scan-based measurements and intraoperative CAOS measurements. Using the 3D scan-based measurements as control, the accuracy (mean error) and precision (associated standard deviation) of the CAOS system were assessed. The impact of extra-articular deformity on the CAOS system measurement errors was also investigated. RESULTS: The pooled mean unsigned errors generated by the CAOS system were equal or less than 0.61 mm and 0.64degrees for resection depths and alignment angles, respectively. No clinically meaningful biases were found in the measurements of resection depths (< 0.5 mm) and alignment angles (< 0.5degrees). Extra-articular deformity did not show significant effect on the measurement errors generated by the CAOS system investigated. CONCLUSIONS: This study presented a set of methodology and workflow to assess the system-level accuracy and precision of CAOS systems. The data demonstrated that the CAOS system investigated can offer accurate and precise intraoperative measurements of TKA resection parameters, regardless of the presence of extra-articular deformity in the knee.

Corrigendum to "Evaluation of the Accuracy and Precision of a Next Generation Computer-Assisted Surgical System"

The Conflict of Interest statement was incorrect in this article.