Advances in the biosynthesis of natamycin and its regulatory mechanisms / 生物工程学报

Natamycin is a polyene macrolide antibiotics with strong and broad spectrum antifungal activity. It not only effectively inhibits the growth and reproduction of fungi, but also prevents the formation of some mycotoxins. Consequently, it has been approved for use as an antifungal food preservative in most countries, and is also widely used in agriculture and healthcare. Streptomyces natalensis and Streptomyces chatanoogensis are the main producers of natamycin. This review summarizes the biosynthesis and regulatory mechanism of natamycin, as well as the strategies for improving natamycin production. Moreover, the future perspectives on natamycin research are discussed.

An anatomic study of superficial temporal artery to anterior cerebral artery bypass using ipsilateral parietal branch of superficial temporal artery as graft / 中华显微外科杂志

Objective Revascularization of the distal segment of the anterior cerebral artery (ACA) using extracranial donors requires long interposition grafts.A novel bypass procedure which uses the two main branches of the superficial temporal artery (STA) to reach the A3 segment of the anterior cerebral artery with a single skin incision was designed.Methods Ten cadaveric specimens were dissected through a single skin incision to harvest the frontal and parietal branches of the STA from June,2017 to September,2017.An anterior interhemispheric approach provided access to the middle internal frontal artery (MIFA).The parietal STA was used as an interposition graft between the frontal STA and MIFA.Lengths and calibers of the distal branches of STA and MIFA were measured at the anastomotic sites.All data was statistical analysis by t-test.Results The average caliber of MIFA was (1.4±0.2) mm,which matched the caliber of both frontal and parietal branches of STA.The mean distance for an end-to-side bypass from STA to MIFA was (144.5±7.4) mm and the average harvested donor-graft complex length was (203.1±27.9) mm.This bypass construct provided around 140％ donor graft length.Conclusion Using the parietal branch of the STA as an interposition graft enabled a successful tension-free STA-MIFA bypass.The advantages of this technique over existing approaches include sufficient graft length,caliber match and relative technical ease.

Reconstruction of anterior inferior cerebellar artery by occipital artery through extended retrosigmoid approach / 中华显微外科杂志

Objective To explore the feasibility of occipital artery(OA) to anterior inferior cerebellar artery (AICA) through the extended retrosigmoid approach,also perform a systemic microanatomical study of OA and AICA with the exposure of extended retrosigmoid approach,find the easy way to perform the procedure.Methods From September,2016 to January,2017,5 adult cadaveric heads injected with colored latex (total 10 sides) were performed the extended retrosigmoid approach,and measured the caliber of distal occipital artery (OA),the final length of the OA harvest,the reliable landmark of the OA harvest,and the distance from the flocculonodular segment of anterior inferior cerebellar artery (AICA) to the OA,the diameter of AICA flocculonodular segment branch.Whole procedure of OA to IACA bypass also be performed.Statistical analysis was performed.Results By the extended retrosigmoid approach,AICA flocculonodular segment could be easily exposure,the average diameter was 1.2 mm,the OA branch could be harvested in average was (72.3±3.3)mm in length from the occipital sulcus,and the average distance between occipital sulcus and AICA flocculonodular segment was (47.6±l.9)mm.The bypass procedure also could be performed through the proper corridor.Conclusion The Extended retrosigmoid approach is a safe and efficient way to perform the OA-AICA bypass procedure,and the procedure is easier to be performed than other surgical approaches.

Microsurgical treatment of solitary fibrous tumor in the central nervous system / 中华显微外科杂志

Objective To explore the clinicopathological features,imaging manifestation and treatment of solitary fibrous tumor in the central nervous system(cSFT),in order to improve the diagnosis and treatment.Methods Fourteen cases of cSFT that had been received microsurgery treatment from June,2010 to July,2016 were analyzed retrospectively.The clinicopathological features,treatment and prognosis were concluded and analyzed.Results In 14 patients with cSFT treated with microsurgery,and 1 case in the foramen magnum region for the first time,and enriched the understanding of this disease.Of 14 patients with cSFT,12 received total resection and 2 subtotal or part.The cSFT were pathologically diagnosed as benign tumors in 11 patients and low grade cSFT in 3.The microscopical presence of spindle-shaped tumor cells arranged in fascicles that alternate hypocellular and hypercellular areas separated from each other by collagenous fibre.Immunohistochemistry was positive for Vimentin,and CD34,Bcl-2 of 14 patients,and positive for CD99 in 12 patients.Followed-up time was from 6 to 49 months.Twelve cases had good prognosis to total resection and 2 recurrence due to subtotal or part resection.Conclusion cSFT is extremely rare,and it has some characteristics on MRI,final diagnosis should be depended on pathological and immunohistochemical examination.There are good prognoses in the patients with cSFT after the total removal of cSFT,but when the lesion could not be totally resected,radiotherapy should be considered,the curative effect of chemotherapy on cSFT is not definitive.

Clinical analysis of intracranial hemangioblastomas treated by microsurgery combined with preoperative in-terventional embolization and its related problems / 中华显微外科杂志

Objective To investigate the clinical effect of microsurgical resection combined with preoperative interventional embolization in the treatment of solid intracranial hemangioblastomas, and to analyze the effect of pre-operative embolization on tumor resection,and to discuss the surgical technique and perioperative management of mi-crosurgery. Methods From September, 2010 to September, 2015, the clinical signs, preoperative embolization, mi-crosurgery and prognosis of 18 patients with solid hemangioblastomas were retrospectively analyzed. The patients were examined by CTA and MRI,18 patients underwent DSA tumor arterial embolization and tumor microsurgery. Results The tumor diameter was 2.5-4.0 cm, the proportion of preoperative embolization tumor was 100% in 4 cases, 80% -95% in 9 cases,60%-70% in 3 cases and 60% in 2 cases.16 cases(88.9%)were subtotal tumors,2 cases(11.1%) were subtotal resection, 1 case died. No patients with intraoperative blood transfusion.followed up for 2 years without tumor recurrence. Conclusion The risk of postoperative hemangioblastomas is high, and the intervention of em-bolization for tumor artery will reduce the risk of operation.Microsurgery is the preferred treatment,and skilled micro-surgery is the key to treatment.