色氨酸酶基因工程菌固定化及其培养条件的研究

对色氨酸酶基因工程菌 ＷＷ－ １１进行固定化及培养条件研究,为工业化生产 Ｌ－色氨酸奠定基础。方法;通过色氨酸酶活力测定,考察三种固定化材料及温度、 ｐＨ、单价阳离子和乙醇对固定化 ＷＷ－ １１色氨酸酶活力的影响。结果：以聚乙烯醇作为ＷＷ－１１的固定化载体,其活力回收为６０．９％。固定化ＷＷ－１１色氨酸酶降解反应最适ｐＨ为９．０、最适温度为５０℃;固定化ＷＷ－１１色氨酸酶合成反应最适ｐＨ为７．５、最适温度为４５℃。Ｋ＋、ＮＨ＋对固定化工程菌色氨酸酶有明显激活作用,而Ｎａ＋则有一定的抑制作用。结论：固定化工程菌色氨酸酶对温度、乙醇等的稳定性比游离菌有显著提高。     

固定化酵母细胞生产1，6－二磷酸果糖的动力学研究

筛选获得一株１,６－二磷酸果糖（ＦＤＰ）的高产酵母菌株,改变通透性后的酵母细胞,在发酵及固定化生产ＦＤＰ过程中发现Ｆｅ２＋和甘油能大量提高ＦＤＰ的积累。将戊二醛交联后的酵母细胞,用卡拉胶固定化后,装入酶反应柱,连续生产ＦＰＤ,柱反应可稳定在１０天以上,转化率维持在２０％以上。     

小儿废用性骨质疏松与骨折

为提高对废用性骨质疏松与骨折的警惕性,探讨其防治措施,对13 例儿童因 髋关节疾病经手术、石膏固定术后1~9个月,发生废用性骨质疏松和骨折进行了回顾性分析 。结果：13例患儿15个部位发生了废用性骨折,经非手术疗法,配合药物治疗,获骨性愈合 。早期确定废用性骨质疏松的诊断,缩短不必要的肢体固定时间,尽早功能锻练,加强保护 ,避免外伤,配合内科药物疗法对防治本病有重要作用。     

Electrical stimulation and muscle strengthening

OBJECTIVES: To identify the effects of application methods and indications of direct muscle electrostimulation on strength gain. METHODS: Literature review and analysis of articles from Medline database with the following entries: muscular or neuromuscular, electromyostimulation, electrical stimulation, strengthening, strength training, immobilization, muscle dystrophy, bed-rest, bed-bound, knee or hip surgery, postoperative phase, cachexia, sarcopenia, and their French equivalent. RESULTS: Because of its specific muscle recruitment order, different from that of voluntary contraction, direct muscle electrostimulation is theoretically a complementary tool for muscle strengthening. It can be used in healthy subjects and in several affections associated with muscle function loss. Its interest seems well-established for post-traumatic or postsurgery lower-limb immobilizations but too few controlled studies have clearly shown the overall benefits of its application in other indications. Whatever the indication, superimposed or combined electrostimulation techniques are generally more efficient than electrostimulation alone. CONCLUSION: Even though widely used, the level of evidence for the efficiency of electromyostimulation is still low. For strength gains, it yielded no higher benefits than traditional strengthening methods. Its interest should be tested in medical affections leading to major muscle deconditioning or in sarcopenia.     

Comparison of the Macintosh laryngoscope and blind intubation via the iGEL for Intubation With C-spine immobilization: A Randomized,crossover, manikin trial

Introduction

Endotracheal intubation (ETI) using a Macintosh laryngoscope (MAC) requires the head to be positioned in a modified Jackson position, slightly reclined and elevated. Intubation of trauma patients with an injured neck or spine is therefore difficult, since the neck usually cannot be turned or is already immobilized in order to prevent further injury. The iGEL supraglottic airway seems optimal for such conditions due to its blind insertion without the need of a modified Jackson position.

Mechanical effects of immobilization on the Achilles' tendon

OBJECTIVE: To measure the biomechanical effects of immobilization on the Achilles' tendon. DESIGN: Experimental, controlled study. SETTING: Physiatry research laboratory. ANIMALS: Twenty adult rabbits. INTERVENTION: One hindlimb immobilized in a cast for 4 weeks (n=10) or 8 weeks (n=10). The contralateral legs (n=20) served as controls. MAIN OUTCOME MEASURES: Cross-sectional Achilles' tendon area, mode of failure, mean failure load, and tendon stiffness. RESULTS: The Achilles' tendon cross-sectional area did not change. Achilles' tendon-calcaneus units failed at insertion at 4 weeks and in controls. Calcaneus fracture was the most prevalent mode of failure at 8 weeks. The mean load to failure of both immobilized groups (4wk: 187.5+/-45.7N; 8wk: 162.6+/-39.3N) was significantly smaller than that of the control group (549.2+/-93.7N, both P<.005). The mean tendon stiffness of both immobilized groups (4wk: 64.6+/-24.8N/mm; 8wk: 53.9+/-19.9N/mm) was significantly lower than that of the control group (125.1+/-26.5N/mm, both P<.005). CONCLUSIONS: Immobility for up to 8 weeks caused decreased stiffness but no atrophy or rupture of the Achilles' tendon, suggesting that immobility does not constitute a risk factor for Achilles' tendon midsubstance rupture. Clinically, graded reloading is required after immobilization to restore the tendon insertion and to reverse calcaneal disuse osteoporosis.     

Effect of carbon source on polysaccharide production by alginate-entrapped Aureobasidium pullulans ATCC 42023 cells

The production of the exopolysaccharide pullulan using entrapped cells of the fungus Aureobasidium pullulans ATCC 42023 was investigated relative to carbon source. Fungal cells grown on glucose or sucrose as a carbon source were entrapped in calcium alginate beads and found to be capable of synthesizing the polysaccharide for two production cycles. Using 2.5% glucose or sucrose as a carbon source, productivity was 18.3 or 21.9 mg polysaccharide/g cells × h, respectively after the initial production cycle and decreased to 9.6 or 8.5 mg polysaccharide/g cells × h, respectively, after the second production cycle. Independent of carbon source, the entrapped fungal cells exhibited a higher yield during the initial cycle than the second production cycle while the entrapped ATCC 42023 cells elaborated a polysaccharide with a higher pullulan content during the second production cycle compared to the initial production cycle.     

葡萄糖氧化酶生物传感器的构建和性能研究

目的以固定化葡萄糖氧化酶酶膜构建葡萄糖生物传感器,并对其性能进行评价。方法优化载体及戊二醛交联固定化条件,制备性能良好的葡萄糖氧化酶酶膜,研究固定化酶的性能并用于构建葡萄糖传感器。结果固定化葡萄糖氧化酶的最适催化温度为40℃、pH为7.0;葡萄糖生物传感器的响应时间小于20 s,在0～1.5 g·L-1葡萄糖浓度范围内有良好的线性,具有很强抗干扰和稳定性。结论该葡萄糖生物传感器性能良好,可用于生物样品中葡萄糖测定。     

局部制动对大鼠胰岛素敏感性影响的研究

目的:了解肢体制动对大鼠胰岛素敏感性的影响.方法:将SD大鼠随机分为对照组、制动组,每组20只.制动组大鼠右后肢石膏固定,对照组不做特殊处理.3wk后将两组大鼠行高胰岛素—正常葡萄糖钳夹技术,术后分离大鼠右比目鱼肌测量质量、肌细胞直径及肌纤维截面积.结果:制动组稳态葡萄糖输入速率[(35±5)mg(/kg·h)vs(13±4)mg/(kg.h)]、右侧比目鱼肌湿质量[(169.2±4.1)gvs(67.1±6.3)g]、肌细胞直径[(49.8±2.7)μmvs(20.6±3.2)μm]、肌纤维截面积[(998±21)μm2vs(579±14)μm2]均明显低于对照组.结论:局部制动可导致大鼠骨骼肌萎缩,并使机体对胰岛素的敏感性降低.