孕妇血清与初乳中分泌型IgA含量的关系

目的探讨孕妇营养与初乳中分泌型免疫球蛋白Ａ（ＳＩｇＡ）含量的关系。方法对１０１例孕妇作了膳食营养评价，并对其血液营养学指标与产后第３ｄ初乳ＳＩｇＡ含量进行相关分析。结果孕妇血清ＩｇＡ与初乳ＳＩｇＡ呈明显的正相关（ｒ＝０．４９８Ｐ＜０．０１）；血清甘油三酯与初乳ＳＩｇＡ呈明显的负相关（ｒ＝－０．３３８Ｐ＜０．００５）；血清叶酸与初乳ＳＩｇＡ呈明显正相关（孕中期ｒ＝０．７３７Ｐ＜０．００１，孕晚期ｒ＝０．３６２Ｐ＜０．０１）相关呈高度显著性。结论初乳ＳＩｇＡ与孕妇个体免疫状态以及孕期代谢状态有关。     

牛初乳复合细胞营养因子（CHF）的体内,外抗菌作用研究

牛初乳复合细胞营养因子（ＣＨＦ）对伤寒杆菌、大肠杆菌、白色葡萄球菌、变形杆菌、绿脓杆菌、福氏痢疾杆菌６种肠道常见致病菌均有一定的正常凝集效价，其中对大肠杆菌和绿脓杆菌的凝集效价与人γ－球蛋白相同。体外试验表明ＣＨＦ对白色葡萄球菌和福氏痢疾杆菌有一定的抑菌作用，且这种抑菌作用不依赖补体的参与。ＣＨＦ可促进小鼠体内抗绿脓杆菌的免疫保护作用，当绿脓杆菌的攻击量达２．８×ＬＤ５０时，就有非常显著的作用，且强度与人γ－球蛋白相似。     

人初乳细胞复合营养因子的体外、体内抗菌活性研究

目的 :探讨人初乳细胞复合营养因子 (humanCellhealthfactors,hCHF)对志贺氏痢疾杆菌、大肠杆菌、金黄色葡萄球菌等 10种常见致病菌的抗菌活性。方法 :以倍比稀释法测定hCHF对常见致病菌的正常凝集效价与体外抑菌试验 ,以鼠伤寒杆菌为例作小白鼠体内抗菌活性试验。结果 :试验表明 ,人初乳细胞复合营养因子 (hCHF)对常见致病菌有一定的凝集效价 ,对大肠杆菌、金葡菌、痢疾杆菌等均有一定的抑菌作用 ,且此抑菌作用不依赖补体参与(P <0 .0 1)。对小白鼠的体内抗菌活性与IgG亦无显著性差异 (P >0 .0 5 ) ,与空白对照组相比有显著性差异 (P <0 .0 5 )。结论 :人初乳细胞复合营养因子对常见致病菌具有较强的抑菌作用 ,且有非常重要的免疫保护作用     

牛初乳粉预防大鼠高血糖的实验研究

目的: 探讨牛初乳粉(BCP)对大鼠糖尿病的预防作用。方法: 给大鼠灌胃三个不同剂量的BCP(BCP)溶液15 d后,腹腔注射链脲霉素(STZ)55 mg/kg。注射后D7测定体重、血糖;D14除上述指标外,还测定血脂、肝肾组织SOD、GSH-Px、NOS及MDA(饮水量在注射后D 6、13 测量)。结果: 注射STZ后D7、D14 ,中剂量BCP组的血糖均显著低于STZ组(P﹤0.05, P﹤0.01)。D13 中剂量组的饮水量少于STZ组。D14 BCP各组的体重、胸腺指数与 STZ组相比差异均无显著性,5个组之间的血脂、肝MDA、肝肾SOD、GSH-Px、NOS差异均无显著性。 结论: 预防性给与中剂量BCP可缓解STZ所致的高血糖,并使STZ大鼠饮水量减少。     

Standardized bovine colostrum derivative impedes development of type 1 diabetes in rodents

Bovine colostrum is a rich source of nutrients and immunologically active components that play a role in conveying passive immunity to the offspring, protection and maturation of new-born’s gastrointestinal tract. Colostrum has exerted positive effects in diseases affecting gastrointestinal tract, as well as type 2 diabetes (T2D). However, health-promoting effects in type 1 diabetes have not been reported. The aim of this study was to investigate therapeutic value of oral administration of standardized bovine colostrum derivative (SBCD) in three models of type 1 diabetes (T1D): spontaneously developed T1D in NOD mice and BB-DP rats, and in chemically induced T1D in C57BL/6 mice with multiple low doses of streptozotocin (MLDS). SBCD was administered per os and the disease development was evaluated by weekly measurement of blood glucose and by histological analyses of the pancreas. SBCD administration prevented diabetes development in all three models, as indicated by euglicaemia. Ex vivo analysis of cytokine expression and production in the spleen and mesenteric lymph nodes (MLN) in MLDS challenged mice revealed a strong modulation of the immune response. In the MLN cells SBCD disrupted harmful Th17 response induced by MLDS. Expression of Th1 signature cytokine IFN-γ was down-regulated in MLN cells of SBCD-treated mice, while IL-4 secretion (Th2 cytokine) was up-regulated in comparison to diabetic group. Modulation of the immune response seen in the MLN protruded to the spleen, giving overall less infiltration of immune cells to the pancreas. SBCD acted on immune cells and halted (auto) aggression towards pancreatic beta cells. Moreover, SBCD induced beta cell proliferation. Hence, this derivative could be tested in diabetes and other similar diseases with aberrant immune response.     

一起生饮羊奶引起的布鲁氏病暴发疫情调查

目的 调查处置一起由食用新鲜“羊初乳”导致的布鲁氏菌病(布病)暴发疫情,为科学开展食源性布病疫情的预防控制提供依据。方法 采用布病个案调查表,对医院报告病例开展流行病学调查,再根据调查线索通过“滚雪球”的方式进行可疑病例搜索调查和实验室采样检测,运用描述性流行病学方法对资料进行分析。结果 本起疫情共确诊6例布病病例,均为同一日在某乳制品公司现场饮用新鲜“羊初乳”的同一参观团人员,罹患率高达50.00%(6/12)。结论 综合病例临床表现、流行病学调查以及实验室检测结果,确定本起疫情为布病暴发疫情,引起原因为生饮未经消毒的羊奶。疫情提示牛、羊等奶制品需加强监管,降低布病发病风险。     

A comparison of the binding of secretory component to immunoglobulin A (IgA) in human colostral S-IgA1 and S-IgA2

A detailed investigation of the binding of secretory component to immunoglobulin A (IgA) in human secretory IgA2 (S-IgA2) was made possible by the development of a new method of purifying S-IgA1, S-IgA2 and free secretory component from human colostrum using thiophilic gel chromatography and chromatography on Jacalin-agarose. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of unreduced pure S-IgA2 revealed that, unlike in S-IgA1, a significant proportion of the secretory component was bound non-covalently in S-IgA2. When S-IgA1 was incubated with a protease purified from Proteus mirabilis the secretory component, but not the alpha-chain, was cleaved. This is in contrast to serum IgA1, in which the alpha-chain was cleaved under the same conditions - direct evidence that secretory component does protect the alpha-chain from proteolytic cleavage in S-IgA. Comparisons between the products of cleavage with P. mirabilis protease of free secretory component and bound secretory component in S-IgA1 and S-IgA2 also indicated that, contrary to the general assumption, the binding of secretory component to IgA is different in S-IgA2 from that in S-IgA1.     

Effect of oropharyngeal colostrum therapy in the prevention of necrotising enterocolitis among very low birthweight neonates: A meta‐analysis of randomised controlled trials

Background

Necrotising enterocolitis (NEC ) is one of the most common life‐threatening emergencies of the gastrointestinal tract in preterm neonates. The present study aimed to determine the efficacy of oropharyngeal colostrum with respect to reducing NEC in preterm neonates.

Methods

A literature search was conducted for various randomised control trials by searching the Cochrane Central Register of Controlled Trials, PubMed, EMBASE and ongoing clinical trials. Randomised or quasi‐randomised trials comparing oropharyngeal colostrum versus placebo in neonates (birthweight ≤ 1500 g or gestational age ≤ 32 weeks) were included in the review. The methodological quality of each trial was independently reviewed by the authors. For categorical and continuous variables, typical estimates for relative risk and typical estimates for weighted mean difference were calculated, respectively. A random effect model was assumed for meta‐analysis.

Results

In total, four eligible trials were included in the review. Oropharyngeal colostrum therapy was not associated with a statistically significant reduction in the incidence of NEC stage ≥2 [typical relative risk (RR ) = 0.64; 95% confidence interval (CI ) = 0.27–1.49], mortality from any cause (typical RR  = 0.86; 95% CI  = 0.15–4.80) and time to reach full feed [typical weighted mean difference (WMD) = ?3.26; 95% CI  = ?8.87 to 2.35]. Duration of hospital stay was significantly less in the control group (typical WMD  = 9.77; 95% CI  = 3.96–15.59).

Conclusions

The current evidence is insufficient for recommending oropharyngeal colostrum as a routine clinical practice in the prevention of NEC . We emphasise the need for large randomised controlled trials with an adequate sample size and validated clinical outcomes in preterm neonates.

     

Immunization of pregnant cows with Shiga toxin-2 induces high levels of specific colostral antibodies and lactoferrin able to neutralize E. coli O157:H7 pathogenicity

E. coli O157:H7 is a foodborne pathogen responsible for bloody diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). The objective of the present work was to evaluate the ability of colostral IgG obtained from Stx2-immunized cows to prevent against E. coli O157:H7 infection and Stx2 cytotoxicity. Hyperimmune colostrum (HC) was obtained from cows intramuscularly immunized with inactivated Stx2 or vehicle for controls. Colostral IgG was purified by affinity chromatography. Specific IgG antibodies against Stx2 and bovine lactoferrin (bLF) levels in HC and the corresponding IgG (HC-IgG/bLF) were determined by ELISA. The protective effects of HC-IgG/bLF against Stx2 cytotoxicity and adhesion of E. coli O157:H7 and its Stx2-negative mutant were analyzed in HCT-8 cells. HC-IgG/bLF prevention against E. coli O157:H7 was studied in human colon and rat colon loops. Protection against a lethal dose of E. coli O157:H7 was evaluated in a weaned mice model. HC-IgG/bLF showed high anti-Stx2 titers and high bLF levels that were able to neutralize the cytotoxic effects of Stx2 in vitro and in vivo. Furthermore, HC-IgG/bLF avoided the inhibition of water absorption induced by E. coli O157:H7 in human colon and also the pathogenicity of E. coli O157:H7 and E. coli O157:H7Δstx2 in rat colon loops. Finally, HC-IgG/bLF prevented in a 100% the lethality caused by E. coli O157:H7 in a weaned mice model. Our study suggests that HC-IgG/bLF have protective effects against E. coli O157:H7 infection. These beneficial effects may be due to specific anti-Stx2 neutralizing antibodies in combination with high bLF levels. These results allow us to consider HC-IgG/bLF as a nutraceutical tool which could be used in combination with balanced supportive diets to prevent HUS. However further studies are required before recommendations can be made for therapeutic and clinical applications.