Showing posts with label diarrhea. Show all posts
Showing posts with label diarrhea. Show all posts

Thursday, 2 February 2012

Pubmed - Bovine immune colostrum against 17 strains of diarrhea bacteria and in vitro and in vivo effects of its specific IgG


Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 122 Nanjing Ninghai Road, Nanjing 210097, PR China.

Abstract


Bovine colostral antibodies of cows immunized with a multivalent vaccine consisting of whole cells of 17 strains of pathogenic diarrhea bacteria were generated, and the specific IgG with high activities and titres directed against these pathogens was purified using an ammonium sulfate precipitation and verified by SDS-PAGE. We demonstrate that specific IgG has a strong activity of inhibiting in vitro growth and colonization in pathogens by agglutinating with bacteria and destroying cell walls. Normal IgG purified from non-immunized bovine colostrum is incapable of eliciting the same consequences as specific IgG. Specific IgG prevents enteroinvasive Escherichia coli/Salmonella typhi-induced diarrhea and may exert an effective protection by enhancing splenic NK cell activity, elevating IL-2 level and inhibiting excessive release of TNF-alpha in mice. Thus, the specific IgG from colostral antibodies of immunized bovine can provide effective protection or therapy for multibacteria-induced diarrhea.



Sunday, 29 January 2012

Pubmed - Bovine colostrum as a biologic in clinical medicine: a review--Part II: clinical studies


Center for Transfusion Medicine Muenster, German Red Cross Blood Transfusion Service West gGmbH, Muenster, Germany.

Abstract

The value of bovine colostrum as a biologic in medicine is documented in clinical trials and supported by relatively large databases containing case reports and anecdotal findings. The main actions include an antibacterial effect and modulation of the immune response. The ability of bovine colostrum concentrates (BCC are polyvalent bovine colostrum concentrates produced from the colostrums of several 100 cows) to neutralize lipopolysaccharides, i.e. endotoxins arising from Gram-negative bacterial pathogens and to inhibit enterogenic endotoxemia in animal models as shown in the last review to have its counterpart in patient therapy. 
Clinical trials with BCC provide evidence that oral application reduces the influx of LPS from the gut and this appears to be a major mechanism underlying its therapeutic effect in patients at risk for Gram-negative septic shock; data from two well-controlled clinical studies with a total of 100 surgical patients have shown that the inhibition of intestinal LPS absorption measured after the application of BCC not only reduced the LPS levels in the peripheral blood but also inflammatory parameters like IL-6 and CRP were found to be diminished. 
The usual daily dose of the commercially available BCC preparation, LactobinA (LC1) is 10 â 20 g daily, but higher doses can be used in the majority of patients because of the low incidence of intolerance problems. In chronic diarrhea involving severe forms of secondary immunodeficiencies, patients receiving LC1 were disease-free for about 4 weeks but the response may be lower in patients with AIDS. 
BCC is effective in infants with hemorrhagic diarrhea caused by infections with enterohemorrhagic E. coli and reduces the likelihood of the disease progressing to a hemolytic uremic syndrome. The safety of newer BCC products obtained from BSE-free regions seems now beyond contention. In the case of LC1, which was used as a commercial dietary foodstuff in Germany until 1992 and tested in three Phase 1 and 5 clinical studies (two trials in patients with secondary immunodeficiencies, one in surgical patients with gastrointestinal disorders, one in patients undergoing open heart surgery and one in pediatric patients with EHEC infections), there were no cases of BSE-associated disease such as the new variant of Creutzfeldt-Jakob disease. 
Side effects of clinical relevance are limited to possible intolerance to lactose and sensitivity to milk proteins as these are also present in many commonly used foodstuffs. Important synergistic actions with conventional drug therapies have been observed with BCC including a reduction in LPS plasma levels in patients with Gram-negative bacterial infections treated with bactericidal antibiotics. 
In healthy persons there are only small concentrations of LPS detectable in peripheral blood (normal values: 3 â 10 pg/ ml plasma, i.e. approximately 0.1 EU/ml). In contrast, elevated systemic levels with concentrations > 300 pg/ml are common in patients with severe Gram-negative sepsis and septic shock. Raised LPS levels occur mainly in patients with Gram-negative bacterial infections who have been treated with bacteriocidal antibiotics. The LPS-lowering effects of BCC are probably due to the numerous active components present in BCC which have their origin in the innate humoral and adaptive immune system of their biologic source, the cow.

Friday, 19 August 2011

Pubmed - Group A rotavirus veterinary vaccines - Colostrum passive immunity


Food Animal Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, USA.

Abstract

Group A rotaviruses cause diarrhea in young livestock and poultry; consequently, vaccination strategies have focused on induction of active or passive immunity. Gnotobiotic pigs and calves serve as useful models to evaluate induction of active immunity by candidate animal or human rotavirus vaccines. However, live attenuated rotavirus vaccines lacked efficacy when administered orally to calves and pigs in the field, presumably because colostral antibodies inhibited vaccine virus replication. The widespread occurrence of rotavirus antibodies in colostrum led to strategies for maternal rotavirus vaccination to boost lactogenic immunity and transfer passive antibodies to the neonate via colostrum and milk. The variable success of maternal rotavirus vaccines in the field is influenced by vaccine dose, strain, inactivating agent, adjuvant, route of administration, and environmental rotavirus exposure levels. The use of genetically engineered rotavirus-like particle vaccines in cows to boost antibodies in mammary secretions shows promise. Such subunit vaccines possess potential advantages over existing vaccines.