核黄素产生菌T30的补料发酵

对核黄素产生菌Ｔ３０补料发酵进行了研究。结果表明，发酵液呈非牛顿特性，充足的溶氧是核黄素高产的关键。补料发酵可以提高核黄素的产量，补料以补糖为主，补单糖或双糖均可。补糖时间与发酵液的ｐＨ值和菌体生长情况密切相关。发酵４８ｈ以后，控制发酵液的ｐＨ值在５．４～６．２之间，多次少量补糖，核黄素的产量可提高２０％～３０％．经补糖发酵后，Ｔ３０的核黄素产量可达８ｇ／Ｌ以上。     

葡萄糖对光滑球拟酵母发酵生产丙酮酸的影响

在30L发酵罐中研究了初始葡萄糖质量浓度和补料方式对光滑球拟酵母WSH-IP303发酵生产丙酮酸的影响．实验确定116.4g/L左右是较为适宜的初始葡萄糖质量浓度,发酵58h时丙酮酸质量浓度和产率分别为58.0g/L和0.516g/g．采用初始葡萄糖质量浓度为53.4g/L,发酵24h分批补料至葡萄糖总质量浓度为115g/L的培养方式,发酵64h时丙酮酸质量浓度和产率分别为60.2g/L和0.559g/g;采用初始葡萄糖质量浓度为62.6g/L,发酵24h开始连续补料至葡萄糖总质量浓度为115g/L的培养方式,发酵72h时丙酮酸质量浓度和产率分别为63.3g/L和0.586g/g,与葡萄糖总质量浓度相似(115g/L)的分批发酵相比,丙酮酸产量分别提高了3.8%和9.1%．实验结果表明适宜的初始葡萄糖质量浓度能促进光滑球拟酵母发酵生产丙酮酸;尽管葡萄糖补料培养可适度提高丙酮酸的产量及产率,但生产强度却有所下降．     

利用真养产碱杆菌生产β-羟基丁酸和β-羟基戊酸的共聚物的摇瓶发酵条件

在摇瓶条件下，综合考虑菌体干重、β－羟基丁酸和β－羟基戊酸共聚物的质量分数、β－羟基戊酸组分的摩尔分数和酸对β－羟基戊酸组分的转化率等指标，以及共聚物的发酵条件包括以丙酸为β－羟基戊酸合成前体时不同初始加入时间和加入量对共聚物发酵的影响。并比较了分别以丙酸和戊酸为β－羟基戊酸合成前体时对共聚物生产的影响。在分析了共聚物发酵过程曲线的基础上，又进一步研究了补料对合成产物的影响。结果表明，丙酸是β－羟基戊酸合成的较好前体；采用合理的补料方式，可使菌体干重、β－羟基丁酸和β－羟基戊酸共聚物的质量分数、β－羟基戊酸组分的摩尔分数，以及酸对β－羟基戊酸组分转化率等指标明显提高，在最佳补料条件下，上述指标可分别达到２７．７ｇ／Ｌ，８０．７％，１６．８％和５４％．     

假单胞菌JW12脂肪酶的补料分批发酵

研究了假单胞菌ＪＷ１２脂肪酶在２Ｌ和２５Ｌ容积发酵罐的补料分批发酵工艺．通过调整碳源补加速率，控制产酶期发酵液ＰＨ在８．２左右，能有效提高脂肪酶的酶活和表观生产率．在２５Ｌ标准发酵罐中，连续补加吐温－８０，最高脂肪酶酶活为１２９．２μｍｏｌ／（ｍｉｎ·ｍＬ），表观生产率为１５．９１     

恒pH补料分批培养技术培养谷胱甘肽合成酶系

采用一种新的补料分批培养技术 ,培养重组大肠杆菌生产谷胱甘肽合成酶系 .在分批培养和补料分批培养期间 ,采用不同的pH控制模式 :在发酵前期采用分批培养 ,加入碱以补偿pH值的降低 ;而在发酵后期 ,采用一种新的恒 pH补料分批培养方式 ,加入葡萄糖和碱调节发酵液的 pH .在这种模式中 ,根据培养过程中的pH变化确定pH参数 .实验结果表明 :同时设置发酵液的 pH上限和下限可避免恒 pH补料分批培养过程中葡萄糖的周期性缺乏问题 ;对于缓冲能力不同的发酵液 ,应设置不同的pH参数来进行 pH的控制     

真养产碱杆菌利用葡萄糖生产聚β-羟基丁酸的摇瓶发酵条件

以葡萄糖为碳源，对真养产碱杆菌生产ＰＨＢ的摇瓶发酵条件进行了探索。研究结果表明，在摇瓶补料条件下，细胞干重和ＰＨＢ质量浓度可分别达到３５．１ｇ／Ｌ和２８．３ｇ／Ｌ，ＰＨＢ对葡萄糖的产率系数为０．３６ｇ／ｇ．     

法夫酵母产虾青素的补料发酵

以法夫酵母 (Phaffiarhodozyma)WSS FF6为产生菌进行产虾青素的补料发酵 ,在通气量为 2 5 0L/h、pH =6.0± 0 .5的条件下 ,先流加高糖浓度的培养基 ,后添加 0 .1%乙醇 ,进行分批补料发酵 ,经 130h发酵后 ,生物量与类胡萝卜素产量分别为 2 7.4mg/mL、2 6.12 μg/mL ,生长得率、产物得率及酵母色素质量分数分别为 0 .4 6、0 .4 4和 0 .95     

核黄素产生菌的补料发酵

通过分析核黄素产生菌E .ashbyii在发酵过程中菌体量、糖质量浓度、pH值、核黄素质量浓度和粘度的变化及菌体形态与核黄素生物合成之间的联系 ,发现 pH值对菌体生长有显著的影响 ,菌体浓度过高会导致发酵液粘度过大 ,通风供氧困难 ,菌体活力下降 .采用先低浓度培养菌体 ,然后根据发酵液 pH值的变化进行多次适量补料 ,不仅可以控制菌体的过度增殖 ,缓解通风供氧不足造成的困难 ,而且还可以保持菌体活力 ,增加核黄素的产量 .     

发酵过程中基于动态解耦的仿人智能协调控制

以青霉素发酵过程为对象,建立了能够反映发酵过程中比生长速率和pH值变化的动态数学模型,并将仿人智能协调控制和仿人智能模糊控制融入到发酵过程的优化控制中进行仿真,对发酵补料系统进行动态解耦控制,实现发酵过程控制的智能化处理,达到优化发酵生产的目的.     

植物乳杆菌HO-69产抗菌肽的培养条件

对L．plantarum HO-69产抗菌肽的营养和培养条件进行了研究。实验结果袁明，MRS培养基是其产抗菌肽的最适培养体系。以碳源、氮源、缓冲盐等为研究因子，对MRS设计部分因子重复实验，采用回归分析确定K2HPO4和牛肉膏为抗菌肽产生的显著影响因子，综合考虑抗菌肽活力与纯化的难度，确定K2HPO4与牛肉膏的质量浓度分别为12g／L与16g／L，蛋白胨质量浓度为6g／L。响应面分析确定HO-69产抗菌肽的最适培养条件为：起始pH值6．61，36．12℃发酵13．87h，在此条件下发酵液的效价由80AU／mL提高到320AU／mL，抗菌肽的产量增加为原来的4倍。     

Laparoscopic feeding jejunostomy: A systematic review

Background Enteral feeding devices have gained popularity since the beneficial effects of enteral nutrition have been clarified. Laparoscopic placement of a feeding jejunostomy is the most recently described enteric access route. In order to classify current surgical techniques and assess evidence on safety of laparoscopic feeding jejunostomy, a systematic review was performed.Methods The electronic databases Medline, Cochrane, and Embase were searched. Reference lists were checked and requests for additional or unpublished data were sent to authors. Outcome measures were surgical technique and catheter-related complications.Results Enteral access for feeding purposes can be effectively achieved by laparoscopic jejunostomy. Laparoscopic jejunostomy can be accomplished by either total laparoscopic or laparoscopic-aided techniques. The most experience was obtained with total laparoscopic placement. Which technique to apply should depend on the surgeon’s expertise. Conversion rate is similar to other laparoscopic procedures. Complications can be serious and therefore strict patient selection should be warranted.Conclusion Laparoscopic feeding jejunostomy is a viable method to obtain enteral access with the advantages of minimally invasive surgery.     

Optimal enteral feeding in children with gastric dysfunction: surgical jejunostomy vs image-guided gastrojejunal tube placement

Purpose

Long-term feeding access in children who fail initial gastrostomy is a management quandary. Although image-guided gastrojejunal feeding tube placement (IGJ) is becoming the access of choice in many centers, few studies have compared long-term results with surgical jejunostomy (SJ). The authors compare outcomes with these 2 techniques.

Method

A retrospective review of 20 children requiring jejunal feeding access after failing initial gastrostomy was done. Procedures were performed at a tertiary referral center by interventional radiologists (IGJ) or board-certified pediatric surgeons (SJ).

Results

Initially, patients underwent IGJ (n = 14) or SJ (n = 6). Image-guided gastrojejunal feeding tube placement patients required gastrostomy at an average age of 23.8 months, with conversion to IGJ an average of 17.2 months later. SJ patients required gastrostomy at average age of 16.2 months, with conversion to SJ 30.7 months later. Of 14 patients undergoing IGJ, 7 (50%) eventually required SJ because of recurring tube management issues. Thus, 13 patients ultimately had SJ, with 11 (85%) Roux-en-Y jejunostomies. Mean operating time for SJ was 158 minutes, with an average of 5.1 days to initiation of feeds, 11 days to full feeds, and 19.9 days to discharge (range, 3-66 days). Image-guided gastrojejunal feeding tube placement patients averaged 4.6 tube adjustments per year requiring fluoroscopic guidance. Surgical jejunostomy averaged 1.5 tube adjustments per year requiring outpatient hospital visits. Image-guided gastrojejunal feeding tube placement patients averaged 3.9 hospital d/y secondary to feeding tube management issues, whereas SJ patients averaged 1.4 hospital days per year.

Conclusion

In this group of children with long-term jejunal feeding access, half of those with IGJ eventually required SJ. Surgical jejunostomy required fewer adjustments and hospitalizations per year. Although initially more invasive than IGJ, SJ may provide more stable feeding access with fewer complications. This represents the first published report comparing long-term outcomes between IGJ and SJ.     

Promoting safe infant feeding practices – the importance of structural,social and contextual factors in Southern Africa

There has been significant progress towards the goal of eliminating vertical transmission of HIV by 2015. However, a question that remains is how we can most effectively prevent late postnatal transmission of HIV through infant feeding. Guidelines published by the World Health Organization in 2010 have been widely adopted. These guidelines place strong emphasis on exclusive breastfeeding, in some countries over‐turning a prior emphasis on formula feeding. Where available, provision of antiretroviral treatment for HIV‐positive mothers or prophylaxis for infants offers additional protection against vertical transmission through infant feeding. However, merely changing guidelines is not sufficient to change practice, particularly with regard to culturally sanctioned forms of feeding, such as mixed feeding. This commentary highlights structural, social and contextual barriers to effective implementation of the guidelines and suggests ways to address some of these barriers.     

早产儿基于提示喂养管理的最佳证据总结

目的 汇总国内外早产儿基于提示喂养管理的最佳证据,为制定科学合理的早产儿喂养方案提供参考。方法 利用计算机系统检索UpToDate、BMJ Best Practice、医脉通、中国知网等中英文数据库或网站中关于早产儿基于提示喂养的证据,包括临床决策、指南、推荐实践、证据总结、系统评价和专家共识,检索时限为建库至2022年3月。 由2名接受过系统循证知识培训的研究人员对文献质量进行独立评价并提取证据。结果 共纳入10篇文献,包括临床决策2篇、指南5篇、系统评价3篇;最终从人员资质、培训、对象、评估、实施、效果评价6个方面汇总了32条证据。结论 总结的早产儿基于提示喂养的最佳证据可为临床提供循证依据,促进早产儿由管饲喂养向经口喂养过渡,实现最佳证据向临床转化。用证人员应结合具体情境针对性地选择证据。     

不同方式喂养婴儿贫血状况调查

目的 探讨婴儿期不同喂养方式与贫血的关系，以改进喂养方法，预防贫血。方法 将195例婴儿（4个月内）根据喂养方式不同分为完全母乳喂养组、人工喂养组和发母乳喂养组，2－4个月及6－9个月筛查血红蛋白各1次，贫血者每月复查，直到血红蛋白恢复正常。结果 2－4个月婴儿贫血检出率平均为35.4%，三种喂养方式之间差异无显著性意义；6－9个月婴儿人工喂养组贫血检出率为10.0%，明显低于母乳喂养组（47.7%）和部分母乳喂养组（31.2%），三种喂养方式之间比较，差异有极显著性意义（P＜0.01）。对母乳喂养组贫血婴儿断乳期的膳食调查发现，多数婴儿对含铁丰富的食物摄入过少，而淀粉类食物摄入过多。结论 应加强对母乳喂养婴儿断乳期的营养指导，嘱家长添加含铁丰富的食物，4个月后应常规给予铁剂口服以预防贫血。     

自编呼吸训练操在口腔喂养能力障碍早产儿中的应用

目的 探讨呼吸训练操应用于改善早产儿口腔喂养能力的效果。方法 将96例住院早产儿按时间段分为两组各48例,对照组行常规护理,观察组在此基础上采用自编呼吸训练操实施干预。结果 观察组干预10 d、15 d后非营养性吸吮评分显著高于对照组（均P＜0.01）;观察组留置胃管时间、经口喂养至全口喂养过渡时间显著短于对照组（均P＜0.01）。结论 呼吸训练操应用于早产儿可提高口腔喂养能力,加快经口喂养进程。     

Is early enteral feeding safe in patients who have suffered spinal cord injury?

OBJECTIVE: To examine whether enteral feeding is a safe technique to use in the acute stage of spinal cord injury. METHODS: We searched the departmental computerised patient database and clinical records for all patients with spinal cord injuries admitted to the Auckland Hospital Intensive Care Unit (ICU), known as the Department of Critical Care Medicine (DCCM), between January 1988 and December 2000. Patients were included in the study if they had suffered complete spinal cord transection resulting in either paraplegia or quadriplegia. Data was collected for the following variables: length of time to commence enteral feeding, type of enteral feeding, duration of enteral feeding and reasons for interrupting the feed. RESULTS: Thirty-three patients were found and were included in the study. Twenty-seven (82%) of the patients commenced enteral feeding in the DCCM, 25 by nasogastric (NG) and 2 by nasojejunal (NJ) tube. Feeding was commenced a median of 2 days after admission and the median length of enteral feeding was 7.7 days. The main feeding complications that resulted in interrupting the feed were high gastric aspirates. One patient commenced on enteral feeding developed medical complications that prevented continuation. Two patients on NG feeding converted to NJ feeding. CONCLUSION: No major complications associated with enteral feeding were seen in this study. This would indicate that enteral feeding can be safely administered in the acute stage of spinal cord injury provided complications are monitored for daily.     

Percutaneous replacement jejunostomy after esophagogastrectomy

A surgically placed jejunostomy tube is a safe and effective means of delivering nutritional support for the postesophagogastrectomy patient. We have previously described a method that permits percutaneous replacement of surgically placed jejunostomy feeding tubes, and now present our results with the use of this technique in 350 consecutive esophagogastrectomy patients. Replacement jejunostomy was required in 17 patients (4.9%). M1 patients had successful percutaneous jejunostomy replacement. There were no procedural complications or deaths. The timing of feeding tube replacement following esophagogastrectomy was predictive of the indication. Before 16 weeks, the indication for feeding tube replacement was intubation and inability to eat (1 patient) or anorexia with weight loss and dehydration (7 patients). At or after 16 weeks, the indications for feeding tube replacement were all related to symptoms resulting from recurrent carcinoma. We conclude that the technique of percutaneous jejunostomy allows the surgeon tremendous flexibility in the management of the postesophagogastrectomy patient as it preserves the advantages of an adjuvant surgically placed feeding tube over the lifetime of the patient. The technique is safe, and the success rate is excellent. Supported by the Evelyn Glick Fund for Thoracic Surgery.     

Laparoscopic feeding jejunostomy: also a simple technique

Summary Placement of feeding tubes is a common procedure for general surgeons. While the advent of percutaneous endoscopic gastrostomy has changed and improved surgical practice, this technique is contraindicated in many circumstances. In some patients placement of feeding tubes in the stomach may be contraindicated due to the risks of aspiration, gastric paresis, or gastric dysmotility. We describe a technique of laparoscopic jejunostomy tube placement which is easy and effective. It is noteworthy that this method may be used in patients who have had previous abdominal operations, and it has the added advantage of a direct peritoneal view of the viscera. We suggest that qualified laparoscopic surgeons learn the technique of laparoscopic jejunostomy.     

Early "sham" feeding of neonates promotes oral feeding after delayed primary repair of major congenital esophageal anomalies

BACKGROUND: To promote the appropriate and early development of the suck and swallow mechanism, we instituted a "sham" feeding protocol in infants undergoing delayed primary repair of an esophageal atresia anomaly. METHODS: Four patients who were born with esophageal atresia required delayed repair and were sham fed before surgical correction. Each infant started with a small volume of oral feeds by using a bottle/nipple with a continuous Replogle suction system placed nasally into the esophageal pouch. They were carefully monitored. The volume of feeds was slowly increased as tolerated. RESULTS: All infants successfully completed the sham feeding protocol before undergoing delayed primary esophageal repair. After repair, they had a shortened time to full oral feeding. CONCLUSION: Our "sham" feeding protocol is safe and very effective in early development of oral feeding mechanisms and shortens time to complete oral feeding after delayed esophageal repair.