Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 2 de 2
Filter
Add more filters










Database
Type of study
Language
Publication year range
1.
Am J Vet Res ; 68(7): 778-82, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17605614

ABSTRACT

OBJECTIVE: To assess the effect of maternal cells or cellular components on neonatal immune responses to intracellular pathogens in calves. ANIMALS: 15 Holstein calves. PROCEDURES: Calves were fed whole colostrum, frozen colostrum, or cell-free colostrum within 4 hours after birth. Leukocytes were obtained from calves before feeding colostrum and 1, 2, 7, 14, 21, and 28 days after ingestion. Proliferative responses against bovine viral diarrhea virus (BVDV) and mycobacterial purified protein derivatives were evaluated. Dams received a vaccine containing inactivated BVDV, but were not vaccinated against mycobacterial antigens. RESULTS: All calves had essentially no IgG in circulation at birth, but comparable and substantial concentrations by day 1. Calves that received whole colostrum had enhanced responses to BVDV antigen 1 and 2 days after ingestion of colostrum. In contrast, calves that received frozen colostrum or cell-free colostrum did not respond to BVDV. No differences were identified among the 3 groups in response to mycobacterial antigens. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that transfer of live maternal cells from colostrum to neonatal calves enhanced responses to antigens against which the dams had previously responded (BVDV), but not to antigens to which the dams were naïve (mycobacterial purified protein derivatives). Results suggested that cell-mediated immune transfer to neonates can be enhanced by maternal vaccination.


Subject(s)
Bovine Virus Diarrhea-Mucosal Disease/immunology , Colostrum/immunology , Diarrhea Viruses, Bovine Viral/immunology , Immunity, Maternally-Acquired/immunology , Animals , Animals, Newborn , Antibodies, Viral/blood , Bovine Virus Diarrhea-Mucosal Disease/virology , Cattle , Cell Proliferation , Colostrum/cytology , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Immunoglobulin G/blood , Immunoglobulin G/immunology , Leukocytes, Mononuclear/immunology , Mycobacterium avium subsp. paratuberculosis/immunology , Paratuberculosis/immunology , Paratuberculosis/microbiology , Pregnancy , Tuberculin/immunology , Vaccination/veterinary
2.
J Appl Physiol (1985) ; 100(3): 759-63, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16269525

ABSTRACT

Equine laminitis is a crippling condition associated with a variety of systemic diseases. Although it is apparent that the prodromal stages of laminitis involve microvascular dysfunction, little is known regarding the physiology of this vasculature. The aim of the present study was to determine the relative responses of equine laminar arteries and veins to the vasoconstrictor agonists phenylephrine (1 nM-10 microM), 5-HT (1 nM-10 microM), PGF2alpha (1 nM-100 microM), and endothelin-1 (1 pM-1 microM). We have determined that laminar veins were more sensitive, with respect to the concentration of agonist required to initiate a contractile response and to achieve EC(50), for all agonists tested. EC50 values, for veins and arteries, respectively, were 84+/-7 vs. 688+/-42 nM for phenylephrine, 35+/-6 vs. 224+/-13 nM for 5-HT, 496+/-43 nM vs. 3.0+/-0.6 microM for PGF2alpha, and 467+/-38 pM vs. 70.6+/-6.4 nM for endothelin-1. Moreover, when expressed as a percentage of the response to a depolarizing stimulus (80 mM potassium), the maximal contractile response of laminar veins exceeded that for the laminar arteries for each agonist. These results indicate that there may be a predisposition for venoconstriction within the vasculature of the equine digit. While this physiological predisposition for venoconstriction may be important in the regulation of blood flow during exercise, it also may help to explain why laminitis can result from a variety of pathological systemic conditions.


Subject(s)
Dermis/blood supply , Foot Diseases/veterinary , Hoof and Claw/blood supply , Horse Diseases/etiology , Horses/physiology , Vasoconstriction , Animals , Arteries/drug effects , Arteries/physiopathology , Causality , Dermis/physiology , Dinoprost/pharmacology , Endothelin-1/pharmacology , Foot Diseases/etiology , Foot Diseases/physiopathology , Horse Diseases/physiopathology , Phenylephrine/pharmacology , Potassium/pharmacology , Regional Blood Flow/drug effects , Serotonin/pharmacology , Vasoconstriction/drug effects , Vasoconstrictor Agents/pharmacology , Veins/drug effects , Veins/physiopathology
SELECTION OF CITATIONS
SEARCH DETAIL
...