Objective To arthroscopically re-observe the remodeling and maturity process following anterior cruciate ligament(ACL) reconstruction with a hamstring tendon autograft.Methods Thirty-three patients who had undergone a previous arthroscopic ACL reconstruction with a homolateral hamstring autograft were given a second observation under arthroscope.The interval from initial reconstruction to second-look arthroscopy ranged 2~36 months(mean,11.9 months).According to different intervals,the patients were grouped as 1~,4~,7~,10~,13~,18~,and 25~ months.The shape,color,tension,covering synovial tissue,and vascularity of the grafts were evaluated.Results As the interval increased,the hamstring grafts tended to progress to normal ACL morphologically.Under arthroscopic observation,the tendon grafts were characterized as grayish-white thick ligamentous tissues without synovial membrane and blood vessels after 7 months following initial reconstruction,which corresponded with the maturation period of autogenous grafts and simulated normal ACL.Conclusions Remodeling and maturation of the hamstring autografts progresses with time,which is comparable to patellar tendon autografts.

Objective To probe into the remodeling and maturity process along with extension of time in anterior cruciate ligament (ACL) reconstruction with hamstring autograft in order to confirm the date of maturity postoperatively. Methods Thirty-three patients after arthroscopic ACL reconstruction with hamstring autograft, were undergone second-look arthroscopical surgery. Meantime, biopsy specimens were obtained from the mid-zone of the hamstring graft. As a control group, specimens of normal ACL were obtained from total knee replacement of four cases, and specimens of semitendinous tendons obtained from ACL reconstruction of the four cases. The interval from initial reconstruction to second-look arthroscopy ranged from 2 to 36 months(mean 11.9 months). Patients were divided into different groups by postoperative time such as 1-, 4-, 7-, 10-, 13-, 18- and 25- month group. Thirty-three specimens were ordinarily sliced up into longitudinal sections. The sections were stained with hematoxylin and eosin so that cell and collagen fibrils were observed under light microscope, then compared the results with those of control group. Results Under microscopical observation, it was showed that tissue of hamstring graft was remodeled from more blood vessels and cellular amount to normal one, and from an irregular orientated crimp pattern of collagen to regular orientated crimp pattern of collagen in a time-dependent manner. Decreasing cellular amount, changing cell type, and a regular orientated crimp pattern of collagen of the hamstring graft were observed in 7- month group primarily, comparing with the original ACL. However, there existed a slower process in the other groups that are older than that of 7- month. Conclusion There are well histological features in the process of remodeling and maturation of the hamstring autograft after operation following extension of time, such as better survival of early period, and remodel of vessels and collagen. The process of remodeling and maturation in the hamstring autograft is similar to BPB autograft. The maturation period of the hamstring autograft after ACL reconstruction in human patients appears between 7 month and 9 month postoperatively.

Objective To explore the therapeutic method and efficacy of discoid meniscus urder arthroscope. Methods 37 patients with 37 discoid menisci underwent arthroscopic lateral partial or total meniscectomy. 33 cases were operated on by reshaping (partial meniscectomy) and 4 cases with extensive laceration in the joint capsule rim of hastring tendon underwent total meniscectomy under arthroscope. Results Bases on Ikeuchi's grading, 19 cases were excellent (51.4%), 13 cases good (35.1%) and 5 cases fair(13.5%). Conclusions Arthroscopic reshaping for discoid meniscus can obtain excellent and good efficacy, so it is recommended that patients with discoid menisci should be treated by reshaping.

Objective To explore the surgical technique and clinical effect of arthroscopic hamstring tendon autograft on reconstruction anterior cruciate ligament (ACL). Methods 22 patients underwent ACL reconstruction with hamstring tendon autograft under arthroscopy. The mean age was 30 7 years (17years～50 years). Results The motion range of knee joint of all cases was normal or nearly normal. The postoperative Lachman test was ≤1+ in 19 patients, 2+ in 2 patients and 3+ in 1 patient. 20 patients also showed an absent pivot shift. The postoperative Lysholm score was (87 7?9 6)points, and the postoperative score increased significantly compared with the preoperative score ( t =2 33, P

Objective To explore the clinical manifestation,imaging features,histopathological classifications and treatment of primary orbital tumors.Methods Twenty-six cases with primary orbital tumors were retrospectively studied.Results All of 26 primary orbital tumor cases received surgical treatment.Sixteen primary orbital tumors cases were male and 10 cases were female.The mean age was 46 years (ranged from 15 to 72).The mean hospital stay was 13 d (ranged from 9 to 21).Among 26 primary orbital tumors cases,21 cases were benign tumors which included 11 cases of cavernous hemangioma,5 cases of inflammatory pseudotumor,3 cases of dermoid cyst,2 cases of venous angioma.Five cases were malignant tumors which included 4 cases of adenoid cystic carcinoma and 1 case of rhabdomyosarcoma.After operation,visual acuity improved in 9 cases,unchanged in 11 cases,decreased in 6 cases.The patients were followed up for 18-48 months (mean,25 months).There were 4 cases of malignant tumors recurrence after operation and received radical operation.While 2 patients were lost,the other 24 patients survived with tumor-free.Conclusions Surgical excision is the main and effective treatment for primary orbital tumors.To be very familiar with the imaging characteristics and local anatomy is the key for operation.Individualized treatment plan should be chosen based on clinical manifestation,imaging features and histopathological classifications.

Sucrose phosphorylase (SPase) gene from Leuconostoc mesenteroides ATCC 12291 was synthesised after codon optimization, and inserted into pET-28a plasmid to generate pET-28a-spase. The recombinant strain Escherichia coli BL21 (DE3)/pET-28a-spase was induced for Spase expression. The recombinant protein Spase was purified and characterized. The specific enzyme activity of SPase was 213.98 U/mg, the purification ratio was 1.47-fold, and the enzyme activity recovery rate was 87.80%. The optimal temperature and the optimal pH of the SPase were identified to be 45 °C and 6.5 respectively, and Km, Vmax and kcat of the SPase for sucrose was 128.8 mmol/L, 2.167 μmol/(mL·min), and 39 237.86 min-1. The recombinant SPase was used for α-arbutin production from hydroquinone and the reaction process was evaluated. The optimal conditions for synthesis of α-arbutin by SPase were 40 g/L hydroquinone, 5:1 molar ratio of sucrose and hydroquinone, and 250 U/mL recombinant SPase at pH 7.0 and 30 °C for 24 h in the dark, and then 500 U/mL glucoamylase was added at 40°C for 2.5 h. Under the optimized process, the yield of α-arbutin reached 98 g/L, and the hydroquinone conversion rate was close to 99%. In summary, the recombinant SPase was cloned and characterized, and its application for α-arbutin production was feasible.

Limonene and its derivative perillic acid are widely used in food, cosmetics, health products, medicine and other industries as important bioactive natural products. However, inefficient plant extraction and high energy-consuming chemical synthesis hamper the industrial production of limonene and perillic acid. In this study, limonene synthase from Mentha spicata was expressed in Saccharomyces cerevisiae by peroxisome compartmentalization, and the yield of limonene was 0.038 mg/L. The genes involved in limonene synthesis, ERG10, ERG13, tHMGR, ERG12, ERG8, IDI1, MVD1, ERG20ww and tLS, were step-wise expressed via modular engineering to study their effects on limonene yield. The yield of limonene increased to 1.14 mg/L by increasing the precursor module. Using the plasmid with high copy number to express the above key genes, the yield of limonene significantly increased up to 86.74 mg/L, which was 4 337 times higher than that of the original strain. Using the limonene-producing strain as the starting strain, the production of perillic acid was successfully achieved by expressing cytochrome P450 enzyme gene from Salvia miltiorrhiza, and the yield reached 4.42 mg/L. The results may facilitate the construction of cell factory with high yield of monoterpene products by S. cerevisiae.
Saccharomyces cerevisiae/metabolism* ; Limonene/metabolism* ; Metabolic Engineering ; Monoterpenes/metabolism*

Anti-reflective nanocoatings that mimic the eyes of fruit flies are biodegradable materials with great market potential for a variety of optical devices that require anti-reflective properties. Microbial expression of retinin provides a new idea for the preparation of nanocoatings under mild conditions compared to physicochemical methods. However, the current expression level of retinin, the key to anti-reflective coating, is low and difficult to meet mass production. In this study, we analyzed and screened the best expression hosts for Drosophila-derived retinin protein, and optimized its expression. Chinese hamster ovary (CHO) cells were identified as the efficient expression host of retinin, and purified retinin protein was obtained. At the same time, the preparation method of lanolin nanoemulsion was explored, and the best anti-reflective ability of the nano-coating was determined when the ratio of specific concentration of retinin protein and wax emulsion was 16:4, the pH of the nano-coating formation system was 7.0, and the temperature was 30 ℃. The enhanced antireflective ability and reduced production cost of artificial antireflective nanocoatings by determining the composition of nanocoatings and optimizing the concentration, pH and temperature of system components may facilitate future application of artificial green degradable antireflective coatings.
Animals ; Cricetinae ; CHO Cells ; Emulsions ; Cricetulus ; Drosophila ; Eye Proteins ; Drosophila Proteins

Objective To investigate the effect of phenformin combined with hexokinase inhibitor 2-deoxyglucose (2-DG) on the treatment of triple-negative breast cancer cell lines 4T1 and MDA-MB-231. Methods Following treatment with phenformin, 2-DG or phenformin combined with 2-DG on 4T1 and MDA-MB-231 cells for 48 h, the cell proliferation in each group was detected by SRB and the apoptosis of cells was detected by flow cytometry. The concentration of glucose and lactic acid in cell culture supernatant was detected by ELISA. The activity of mitochondrial respiratory chain complex Ⅰ was detected by FlexStation3 and the mitochondrial oxygen consumption (OCR) was assayed with the Seahorse X Fe Analyzer. Results The hexokinase expression (4.6±0.17,3.73±0.21), glucose consumption (356±31，397±42) μg/10⁵ cells , Lactic acid concentration (5.59±0.52, 7.83±0.78) μmol/L in the supernatant of 4T1 and MDA-MB-231 cells in Phenformin group were higher than that in control group ( 1±0.15，1±0.12 ) , ( 289±25，301±32) μg/10⁵cells , ( 2.37±0.18，4.01±0.45) μmol/L (P < 0.01). Even if the dose was reduced by 90%, the cell viability of phenformin combined with 2-DG group (64.63±2.28, 51.97±2.29) % was still higher than that of phenformin group (86.70±1.83, 85.53±1.46) % (P<0.001). The combination of the two drugs significantly promoted the apoptosis of 4T1 and MDA-MB-231. In addition, compared with the phenformin group (5.59±0.52, 7.83±0.78) μmol/L, the phenformin combined with 2-DG group (3.46±0.37, 5.18±0.62) μmol/L cell lactic acid production also greatly reduced (P<0.01). Compared with the phenformin or 2-DG single-drug group, the phenformin combined with 2-DG group can significantly inhibit the growth rate of tumors in tumor-bearing mice (P<0.01). The median survival time of tumor-bearing mice in the phenformin combined with 2-DG group was 72.5 d, which was higher than that in the phenformin group 57 d and 2-DG group 55.5 d (P<0.01). Conclusion Hexokinase inhibitor 2-DG significantly enhances the therapeutic effects of phenformin on triple-negative breast cancer cells.

With the environmental pollution caused by waste plastics becoming increasingly serious, biodegradable polyester has become the focus of public attention. Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable polyester formed by the copolymerization of aliphatic and aromatic groups, which has excellent performance of both. The degradation of PBAT under natural conditions requires strict environmental conditions and long degradation cycle. To address these shortcomings, this study explored the application of cutinase in PBAT degradation and the impact of butylene terephthalate (BT) content on the biodegradability of PBAT, so as to improve the degradation rate of PBAT. Five Polyester degrading enzymes from different sources were selected to degrade PBAT to pick out the most efficient enzyme. Subsequently, the degradation rate of PBAT materials with different BT content were determined and compared. The results showed that cutinase ICCG was the best enzyme for PBAT biodegradation, and the higher the BT content, the lower the degradation rate of PBAT. Furthermore, the optimum temperature, buffer type, pH, the ratio of enzyme to substrate (E/S) and substrate concentration in the degradation system were determined to be 75 ℃, Tris HCl, 9.0, 0.4% and 1.0% respectively. These findings may facilitate the application of cutinase in PBAT degradation.
Polyesters/chemistry* ; Adipates