小麦面筋蛋白质的乙酰化改性

采用乙酸酐对小麦面筋蛋白质进行酰化改性 .结果表明 :小麦面筋蛋白质乙酰化的最佳反应条件为面筋蛋白质质量分数 5 % ,反应温度 35℃ ,乙酰酐用量为小麦面筋蛋白质用量的 15 % ;乙酰化改性后的面筋蛋白质 ,溶解度、乳化能力和起泡能力均得到了提高 ,乙酰化小麦面筋蛋白质对弱筋粉粉质特性的改善效果强于普通谷朊粉 .     

淀粉和水分质量分数对脱脂豆粕制备仿生肉特性的影响

利用双螺杆挤压机,以脱脂豆粕(DSM)为主要原料,同时以浓缩大豆蛋白(SPC)作对比,考察了玉米淀粉添加量及混合物水分质量分数对仿生肉制品硬度和粘附力的影响.结果表明:以DSM为主要原料,添加玉米淀粉质量分数6%及控制水分质量分数26%的条件下,在机筒中心温度为135 ℃挤压所得产品在硬度上与对照牛肉干样品接近;同样在添加玉米淀粉质量分数13%和控制水分质量分数为40%的条件下,所得产品的粘附力与牛肉干较接近.根据仿生肉制品质量评估权重系数(硬度为70%,粘附力为30%)得到制备仿生肉制品的DSM与玉米淀粉最佳质量比为15∶2.制品的密封保存有利于贮藏稳定性.利用扫描电镜观察了仿生肉制品的微观结构呈多层、纤维状结构.     

戊聚糖提取工艺中分离蛋白质方法的比较

作者通过综合考虑除蛋白质方法对戊聚糖得率,戊聚糖中阿魏酸质量分数等4项指标的影响,对提取戊聚糖工艺中常用的5种分离蛋白质方法进行比较,确定了除蛋白质的最优方法.     

亲水胶体对含酒精O/W(水包油)乳状液稳定性的影响

研究了卡拉胶、刺槐豆胶,及其混和胶作为稳定剂,对以酪蛋白酸钠稳定的含酒精O/W乳状液体系稳定性的影响.结果表明,单独添加一定浓度的卡拉胶可改善体系的分层稳定性,而单独加入刺槐豆胶会加速体系失稳,当m(卡拉胶)∶m(刺槐豆胶)=4∶1加入到体积分数为15%的酒精乳状液中,加入量为0.02%时体系稳定性最好.同时研究了两多糖的加入方式、热处理时间,以及蔗糖存在下对乳状液稳定性及黏度的影响.结果表明,卡拉胶与刺槐豆胶分别加入到乳状液中稳定效果较好,并且卡拉胶和刺槐豆胶分别在90℃保温6min后加入有利于体系的稳定;质量分数为10%的蔗糖存在增强了复合胶存在下体系的稳定性.     

卡拉胶及糖、盐存在时对勾兑牛奶酒稳定性的影响

探讨了乙醇体积分数、卡拉胶质量分数以及卡拉胶与糖、盐共存时对牛奶酒体系稳定性的影响 .结果表明 ,随着乙醇体积分数的增加 ,牛奶酒体系粘度呈线性增加 ,当乙醇体积分数超过30 %时其稳定性被破坏 .卡拉胶的加入会对体系的稳定性产生一定的改善作用 ,而柠檬酸三钠的添加 ,能使这种改善作用明显提高 .添加质量分数为 10 %的蔗糖对稳定性不能起到改善作用 ,当柠檬酸三钠和蔗糖共同存在时 ,对体系的稳定性影响以蔗糖为主 .同时 ,在柠檬酸三钠存在下 ,将添加卡拉胶的牛奶酒在 4 0℃条件下进行加速贮藏试验 ,测定了这一过程中pH值、粘度和色度的变化     

膜分离技术在提取银杏叶黄酮类化合物中的应用

研究了银杏叶中黄酮类化合物的提取过程及工艺,使用超滤技术对粗提的产品进行精制,对影响超滤的工艺条件如压力、温度、时间进行考察,确定了最佳的提取条件:乙醇水溶液体积分数50%、提取温度80℃、料液质量体积比1 g:10 mL、提取时间2 h.提取物中黄酮质量分数达到5.96%,超滤后的产品中黄酮质量分数达到33.99%.     

谷氨酰胺转胺酶对面粉品质的改良作用

应用单一酶制剂谷氨酰胺转胺酶对面粉进行了品质改良研究,结果表明,谷氨酰胺转胺酶可以催化面筋蛋白形成ε (γ 谷氨酰基)赖氨酸共价键,从而明显改善面团的粉质特性,使面团的形成时间、稳定时间、断裂时间增加,面团的弱化度降低.在拉伸曲线中可以看出加酶的面团抗延伸阻力增加,面团的延伸性下降,粉力增加到2～3倍后逐渐稳定.应用AR 1000流变仪根据时间扫描动态测量模式考察了面团的贮能模量随酶反应时间的变化情况,与对照相比,添加质量分数为0.25%和0.5%的谷氨酰胺转氨酶可使面团的贮能模量显著增加,0.5%的加酶量使贮能模量增加更快.此外,加酶面团的持水性增大,面团的表面黏性下降.     

浑浊苹果汁生产工艺的改进

苹果破碎前在45℃热水中处理45min,在30℃破碎可以增加果汁中果胶的含量和悬浮颗粒的ξ电位,增加了果汁的浊度和浑浊稳定性.苹果破碎时用质量分数0.02%的VC和0.044%的NaCl组合防褐变剂代替国内报道工艺中使用的质量分数0.05%～0.08%的VC,既经济又较好地防止了褐变效果,且减轻了由VC降解引起的非酶褐变.该工艺生产出的产品有较高的浊度和较好的颜色,果汁中颗粒的平均粒径为1.770μm.     

发酵法生产高纯度低聚果糖

将筛选得到的酵母添加于固形物质量分数为 2 5 %的普通级低聚果糖 (FOS)溶液中 ,以消除产品中的副产物葡萄糖 ,提高FOS的含量 .研究了固形物质量分数、起始 pH值、酵母添加量对消除葡萄糖的影响 ,得到了不含葡萄糖且FOS质量分数达 82 .85 %的产品 .后者再经果糖转移酶作用 ,于 5 0℃、pH 5 .5下反应 10h ,FOS质量分数可提高至 85 .2 3% .     

多菌种混合发酵生脉饮药渣生产蛋白饲料工艺条件优化

以生脉饮药渣为原料,利用康宁木霉(Tk)、产黄纤维单胞茵(Cf)、产朊假丝酵母(Cu)和黑曲霉(An)多菌种混合发酵生产蛋白饲料.通过单因素和正交试验对发酵条件进行优化,试验结果表明:先接种20%的Tk Cf(比例2:1),发酵2 d后再接种20%的Cu An(比例1:1),在(NH4)2SO4添加量为5 g/dL、初始PH值为6、料水比为1:2、温度为30℃的条件下发酵5 d,其发酵产物中真蛋白质量分数增加86.96%,粗纤维质量分数降低20.09%.     

小麦麸皮中戊聚糖的纯化分级及组成分析

用乙醇逐步沉淀和离子交换柱层析方法对麸皮中制备的水溶戊聚糖(WSP)和水不溶戊聚糖 (AEP)进行分级纯化 ,并对各组分的组成进行了分析 .结果表明 ,用乙醇逐步沉淀时 ,随着乙醇体积分数的增加 ,所得分级组分具有较高的分支 ;用离子交换柱层析时 ,WSP可分级为 2个组分 ,AEP可分级为 3个组分 ,并且用NaCl较H2 O洗脱的组分具有较高的分支和较高的相对分子质量     

Enteral nutrition in HPB surgery: past and future

Perioperative nutrition has, during the past century, been transformed from a tool to provide calorie and nitrogen support to a tool to boost the immune system and increase resistance to complications. Despite all the progress in medicine and surgery, perioperative morbidity, the rate of infections, thrombosis, and the development of serosal adhesions has remained the same as long as can be judged, or at least during the past 80 years. Most prone to develop complications are persons above the age of 65 and persons with depressed immunity. About 80% of the immune system is localized in the gastrointestinal tract, which offers great opportunities for modulation through enteral nutrition. As the stomach has a tendency to develop postoperative paralysis, tube feeding is often necessary. In 1918, Andresen demonstrated the advantages of enteral nutrition, which already started on the operating table. Mulholland and colleagues and Rhoads and co-workers demonstrated, during the 1940s, certain advantages of enteral tube feeding. Also, the works by Alexander, Fischer, and Ryan, and their co-workers supported the value of early enteral feeding, and suggested enteral feeding as an effective tool to boost the immune system. It was, however, works published in the early 1990s, by Moore and colleagues and by Kudsk and colleagues, which made surgeons more aware of the advantages of early enteral nutrition. Surgery in the hepatobiliary pancreatic field is known to have a high rate of complications. Uninterrupted perioperative nutrition, i.e., nutrition during the night before, during surgery, and immediately after, offers a strong tool to prevent complications. It is essential that the nutrition also provides food for the colon, e.g., fiber and healthy bacteria (probiotics) to ferment the fiber and boost the immune system. Received: February 19, 2002 / Accepted: March 8, 2002 Offprint requests to: S. Bengmark     

Liver transplant in patients with hepatocellular carcinoma

Liver transplant in patients with cirrhosis and hepatocellular carcinoma is indicated in the early stages of the disease, which can be achieved with early detection programs using liver ultrasound. Dynamic imaging techniques (ultrasound with contrast, magnetic resonance and tomography) are essential in the diagnosis of this tumour, being able to type the lesion clearly, and, in the majority of cases, lead to the therapy to follow. Surgery is the treatment of choice in these patients, and liver transplant, from a theoretical point of view, is the best. Currently, the size and number of nodes play an important role in the indication of a transplant. The best liver transplant results are obtained in these patients using the Milan criteria, with survivals that exceed 70% and recurrence indices of 15%, at 5 years. Nowadays we have the possibility of using neo-adjuvant treatments to transplant, such as arterial chemoembolisation, percutaneous ablation techniques, and even liver resection as a bridging technique. The survival of patients transplanted due to liver cancer is similar to that obtained for other non-tumour diseases. In Spain it is 1, 3 and 5 years and 82%, 70% and 60%, respectively. The recurrence is between 6.4% and 16%, micro- and macrovascular invasion being its highest risk variable.     

Vertebral body integrity: a review of various anatomical factors involved in the lumbar region

Summary The body of the vertebra can be affected in the majority of the conditions involving the lumbar spine. Multiple references, both books and periodicals, have been reviewed, and the anatomical factors responsible for the vertebral body integrity in the lumbar spine have been included under the following important areas, namely, morphology, development, genetics, microscopic examination using histology, structural architecture, blood supply, neuromuscular control, and biomechanics. Introduction The anatomy provides a three-dimensional frame work to support the interaction between the physiological and pathological alterations. The body of the vertebra can be affected in a majority of acute or chronic conditions involving the lumbar spine. The etiology of these conditions is multifactorial, which has been dealt with in previous studies sporadically. This study aims to review and incorporate the important anatomical factors which can influence the integrity of vertebral bodies in the lumbar region and manifest as low back pain. Methods Multiple references, both books and periodicals, have been reviewed for the literature. Electronic databases, including Medline and PubMed, were used to collect the latest information. They were finally arranged in an anatomical framework for the article. An attempt has been made to cover these relevant issues in an integrated way in the article and have been structured into introduction, morphology, development, genetics, microscopic examination using histology, structural architecture, blood supply, neuromuscular control, biomechanics, and conclusion. The aforementioned anatomical aspects, some of which have received less attention in the literature, may be helpful to clinicians for restoring the mobility, stability, and load bearing capacity of the lumbar spine as well as planning better management strategies, especially for the chronic low back pain. Results In our article all the anatomical factors affecting the integrity of vertebral body, including the morphology, development, genetics, growth and ossification, blood supply, specifically in the lumbar region, have been described, which were not covered earlier. The limitations of this review is its wide dimensions; hence, there are fair scopes of missing many relevant facts, as all of them cannot be compiled in a single article. We have attempted to confine our views to different anatomical domains only, this is our second limitation. Additional studies are required to incorporate and discuss the uncovered relevant scientific details. Conclusions The integrity of the body of the lumbar vertebra is multifactorial (Fig. 8). The vast spectrum of the anatomical domain influencing it has been summarized. The evolution of erect posture is a landmark in the morphology of human beings and the lumbar lordosis, which has also contributed to the gross design of the vertebral body, is one of the most important adaptations for axial loading and bipedal movements. The role of metamerism in the evolution of vertebrate morphology is repeated in the development of spine. The body of the vertebra is intersegmental in origin, which results in dual vascular and nerve supply, both from superior and inferior aspects of the body of the lumbar vertebrae. The vertebral body ossifies from three primary centers, one for centrum, which will form the major portion of body, and the other two for neural arches. The cartilaginous growth plate is mainly responsible for the longitudinal vertebral growth. Regional differentiation of the vertebral column, and the definite pattern of the structure of the different vertebra, is regulated by a large number of genetic factors, including the Hox genes. The vertebral body design therefore provides the requirements for optimal load transfer by maximal strength with minimal weight. Bone mineral density (BMD), bone quality, microarchitecture, and material properties are the important factors that contribute to bone strength. BMD is highly heritable; bone mineral distribution and architecture are also shown to be under strong genetic influence. All the aforementioned factors finally integrate to ensure mainly the mobility, stability, and load bearing capacity of the lumbar spine.     

Atypical subtrochanteric and diaphyseal femoral fractures: Report of a task force of the american society for bone and mineral Research

Reports linking long‐term use of bisphosphonates (BPs) with atypical fractures of the femur led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a task force to address key questions related to this problem. A multidisciplinary expert group reviewed pertinent published reports concerning atypical femur fractures, as well as preclinical studies that could provide insight into their pathogenesis. A case definition was developed so that subsequent studies report on the same condition. The task force defined major and minor features of complete and incomplete atypical femoral fractures and recommends that all major features, including their location in the subtrochanteric region and femoral shaft, transverse or short oblique orientation, minimal or no associated trauma, a medial spike when the fracture is complete, and absence of comminution, be present to designate a femoral fracture as atypical. Minor features include their association with cortical thickening, a periosteal reaction of the lateral cortex, prodromal pain, bilaterality, delayed healing, comorbid conditions, and concomitant drug exposures, including BPs, other antiresorptive agents, glucocorticoids, and proton pump inhibitors. Preclinical data evaluating the effects of BPs on collagen cross‐linking and maturation, accumulation of microdamage and advanced glycation end products, mineralization, remodeling, vascularity, and angiogenesis lend biologic plausibility to a potential association with long‐term BP use. Based on published and unpublished data and the widespread use of BPs, the incidence of atypical femoral fractures associated with BP therapy for osteoporosis appears to be very low, particularly compared with the number of vertebral, hip, and other fractures that are prevented by BPs. Moreover, a causal association between BPs and atypical fractures has not been established. However, recent observations suggest that the risk rises with increasing duration of exposure, and there is concern that lack of awareness and underreporting may mask the true incidence of the problem. Given the relative rarity of atypical femoral fractures, the task force recommends that specific diagnostic and procedural codes be created and that an international registry be established to facilitate studies of the clinical and genetic risk factors and optimal surgical and medical management of these fractures. Physicians and patients should be made aware of the possibility of atypical femoral fractures and of the potential for bilaterality through a change in labeling of BPs. Research directions should include development of animal models, increased surveillance, and additional epidemiologic and clinical data to establish the true incidence of and risk factors for this condition and to inform orthopedic and medical management. © 2010 American Society for Bone and Mineral Research.     

腹膜粘连的细胞机制研究进展

腹膜粘连（PA）是由手术、腹膜炎症、腹膜透析等引起的腹腔内受损组织和器官间的异常纤维性粘连带，其中手术是引发PA的主要原因。PA可引起不孕、肠梗阻、肠穿孔等临床并发症，二次松解手术为主要治疗方案，但易复发且存在多种并发症风险。近年来开发出一系列用于PA预防与治疗的药物和屏障材料，但防治效果尚不满意。抗PA药物会增加出血的风险，并抑制正常免疫功能，屏障材料虽然一定程度上缓解了PA进展，但因其不能持久覆盖腹膜损伤部位、降解不彻底等问题，不能达到抗PA的理想效果。因此在PA防治上需要新的突破。近期的研究表明PA是一系列事件综合作用的结果，包括血管损伤、血小板聚集、凝血级联反应、纤维蛋白沉积等过程，最终纤维蛋白和细胞外基质沉积形成粘连带，后期形成收缩性瘢痕并引发临床症状，上述事件中，参与PA的各种细胞发挥了关键作用。腹膜微环境中分布有腹膜间皮细胞（PMC）、中性粒细胞、嗜酸性粒细胞、T淋巴细胞、巨噬细胞、肥大细胞等。生理条件下，这些细胞成分对腹膜微环境的动态稳定具有重要意义。当细菌和异物侵入腹膜腔时，纤维蛋白和炎性细胞随腹腔液渗出以限制、清除并吸收异物，最终纤维蛋白被吸收，腹膜损伤正常愈合。病...     

Regulation of spermatogenesis by paracrine／autocrine testicular factors

Spermatogenesis is a complex process regulated by endocrine and testicular paracrine/autocrine factors.Gonadotropins are involved in the regulation of several testicular paracrine factors, mainly of the IL-1 family and testicular hormones. Testicular cytokines and growth factors (such as IL-1, IL-6, TNF, IFN-T, LIF and SCF) were shown to affect both the germ cell proliferation and the Leydig and Sertoli cells functions and secretion. Cytokines and growth factors are produced by immune cells and in the interstitial and seminiferous tubular compartments by various testicular cells, including Sertoli, Leydig, peritubular cells, spermatogonia, differentiated spermatogonia and even spermatozoa. Corresponding cytokine and growth factor receptors were demonstrated on some of the testicular cells. These cytokines also control the secretion of the gonadotropins and testosterone in the testis. Under pathological conditions the levels of pro-inflammatory cytokines are increased and negatively affected spermatogenesis. Thus,the expression levels and the mechanisms involved in the regulation of testicular paracrine/autocrine factors should be considered in future therapeutic strategies for male infertility. (Asian J Androl 2004 Sep; 6: 259-268)     

Silymarin, the antioxidant component of Silybum marianum, prevents sepsis-induced acute lung and brain injury

BACKGROUND: Sepsis is associated with enhanced generation of reactive oxygen species, which leads to multiple organ dysfunctions. Based on the potent antioxidant effects of silymarin, we investigated the putative protective role of silymarin against sepsis-induced oxidative damage in lung and brain tissues. MATERIALS AND METHODS: Sepsis was induced by cecal ligation and perforation (CLP). Sham and CLP groups received either vehicle or silymarin (50 mg/kg, p.o.) or 150 mg/kg i.p. N-acetylcysteine (NAC) for 10 days prior and immediately after the operation. Six hours after the surgery, rats were decapitated and blood was collected for the measurement of proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-1 beta [IL-1 beta], and IL-6) levels, lactate dehydrogenase activity, and total antioxidant capacity. Lung and brain samples were taken for the measurement of malondialdehyde and glutathione levels, myeloperoxidase activity, thromboplastic activity, and also for histological assessment. Formation of reactive oxygen species in tissue samples was monitored by using chemiluminescence technique with luminol and lusigenin probe. RESULTS: Sepsis increased serum TNF-alpha, IL-1 beta, IL-6 levels, and lactate dehydrogenase activity and decreased total antioxidant capacity. On the other hand, tissue glutathione levels were decreased while malondialdehyde levels and myeloperoxidase activity were increased in both the lung and the brain tissues due to CLP. Furthermore, luminol and lucigenin chemiluminescence were significantly increased in the CLP group, indicating the presence of the oxidative damage. Silymarine and NAC treatment reversed these biochemical parameters and preserved tissue morphology as evidenced by histological evaluation. CONCLUSIONS: Silymarin, like NAC, reduced sepsis-induced remote organ injury, at least in part, through its ability to balance oxidant-antioxidant status, to inhibit neutrophil infiltration, and to regulate the release of inflammatory mediators.     

Percutaneous thrombolysis of thrombosed haemodialysis access grafts: comparison of three mechanical devices.

BACKGROUND: Percutaneous thrombolysis has become an accepted treatment of thrombosed haemodialysis grafts. Several devices have been developed for mechanical thrombolysis, which macerate the clot using different mechanisms such as aspiration and fragmentation. The aim of our study was to compare the efficacy of three devices for mechanical thrombolysis in removing the thrombus from thrombosed haemodialysis access grafts and to determine the initial technical and clinical success, complication rates of each device, and graft patency after the procedure. METHODS: Thrombolysis (i.e. clot removal followed by percutaneous transluminal angioplasty (PTA)) was performed in 68 thrombosed haemodialysis grafts using the Cragg brush catheter combined with urokinase in 13, the Hydrolyser in 18 and the Arrow-Trerotola Percutaneous Thrombolytic Device (PTD) in 37. Clot removal scores (CRS, the ability to thoroughly remove clot from the access), initial technical success, clinical success, patency at 30, 60, and 90 days, and complication rates were evaluated. RESULTS: CRS for the Cragg brush, Hydrolyser and PTD were good in 92, 44, and 95% of cases, respectively. Initial technical (85, 83, and 95%) and clinical success (62, 67, and 86%), mean patency rates at 30 (73, 60, and 55%), 60 (61, 53, and 49%), and 90 (49, 40, and 43%) days, stenosis after PTA (33, 46, and 21%) and complication rates (8, 6, and 0%) were not different for the three devices. Success rates and graft patency depended on the effect of PTA, irrespective of the device used. CONCLUSIONS: The rotational devices removed clots more effectively than the Hydrolyser, with the PTD having the advantage of not requiring urokinase. However, the result of PTA in the treatment of underlying stenoses was the only predictive value for graft patency.