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Biomedical subjects

F Blecha

Publications and source records attributed to F Blecha.

97 records · Page 6Linked to original sources
PubMed1981

Cold stress reduces the acquisition of colostral immunoglobulin in piglets.

One-hundred and fourteen piglets were utilized in two experiments designed to determine the effect of a single or intermittent exposure to cold air on the acquisition of colostral gamma globulin. Piglets were allotted before nursing according to weight and sex to a thermoneutral (36 C) or a cold (10 C) treatment group. After nursing, gamma globulin in serum increased in both thermoneutral and cold-stressed piglets. However, the single 2.5-hr cold exposure near birth lowered (P less than .01) gamma globulin concentrations in serum at 14.5 hr of age and tended (P less than .10) to lower immunoglobulin levels at 24, 36 and 48 hr after thermal treatment. In the second experiment, three intermittent 1-hr exposures to 10 C during the first 15 hr of life consistently lowered serum gamma globulin by comparison with concentrations in the serum of piglets held at thermoneutrality (36 C), but these differences were not significant. Piglets dying before 21 days had lower (P less than .10 and P less than .01, Exp. 1 and Exp. 2, respectively) gamma globulin concentrations in the serum during the first day of life than did those piglets that survived. These data indicate that a single 2.5-hr exposure to cold air temperatures at birth reduces the subsequent acquisition of colostral immunoglobulin. A reduction in the amount of antigen-specific antibody from colostrum may contribute to preweaning mortality among young pigs.

Animals↗
PubMed1981

Effects of prepartum protein restriction in the beef cow on immunoglobin content in blood and colostral whey and subsequent immunoglobin absorption by the neonatal calf.

Protein intake of first-calf beef heifers was restricted during the last 100 days of gestation, and the effects on passive transfer of colostral immunoglobins from the cow to the neonatal calf were examined. There were no significant correlations between concentration of immunoglobins (IgM, IgG1 and IgG2) in the sera or colostrum of the cow and prenatal crude protein consumption (.52 to .98 kg crude protein/day). Absorption of certain colostral immunoglobins (IgG1, and IgG2) by the calf were positively correlated (P less than .01) at 12, 18, 24 and 36 hr after birth to the maternal crude protein consumption. Colostrum was collected from the first milkings of pluriparous dairy cows, and then freeze-dried, mixed and reconstituted to be equivalent to 1 liter of colostrum. Mean IgG1 concentrations for the high and low protein groups were 6.02 +/- .90 and .78 +/- .15 mg . ml-1 (P less than .01), respectively. No relationship (P greater than .05) was found between the concentration of IgM in calf sera and daily crude protein intake of the dam. These data indicate that there was a selective decrease in absorption of IgG1 and IgG2 in calves from heifers fed low protein prenatal diets.

Animals↗
PubMedDate not supplied

Porcine antimicrobial peptides: new prospects for ancient molecules of host defense.

Antimicrobial peptides (AMPs) are small, endogenous, polycationic molecules that constitute a ubiquitous and significant component of innate immunity. These natural antibiotics have broad microbicidal activity against various bacteria, fungi, and enveloped viruses. Because most AMPs kill bacteria by physical disruption of cell membranes, which may prevent microorganisms from developing resistance against these agents, they are being explored as possible alternatives to conventional antibiotics. Pigs, like many other mammals, produce an impressive array of AMPs, which are synthesized predominantly by host leukocytic phagocytes or mucosal epithelial cells. Currently, more than a dozen distinct porcine AMPs have been identified and a majority belongs to the cathelicidin family. This review briefly summarizes recent advances in porcine AMP research with an emphasis on the diverse biological functions of each peptide. Mechanisms of action of these AMPs and their role in the resistance to infections are considered. Finally, the current status of pharmaceutical and agricultural uses of AMPs as well as future prospects for their application in the food animal industry is discussed.

Amino Acid Sequence↗
PubMedDate not supplied

Immunological characterization of pulmonary intravascular macrophages.

Pulmonary intravascular macrophages (PIMs) are lung macrophages found apposed to the endothelium of pulmonary capillaries. In many species, they are responsible for the clearance of blood-borne particulates and pathogens; however, little else is known about their roles as immunologic effector cells. We compared PIMs with pulmonary alveolar macrophages (PAMs) to determine the relative immunological activities of these two cell populations. Our results suggested that both populations possess similar phagocytic and bactericidal activities. In assays measuring cytotoxicity, PIMs were more cytotoxic than PAMs against virally infected target cells; however, differences between these macrophage populations were not as marked when noninfected targets were used. LPS-stimulated PIMs produced more T-cell proliferative cytokines than PAMs, and both populations of nonstimulated macrophages produced similar amounts of the cytokines. In contrast, PAMs produced more TNF alpha and NO2- than PIMs when both populations were stimulated with LPS; however, nonstimulated PAMs and PIMs produced similar amounts of TNF alpha and NO2. These data suggest that bovine PIMs are immunologically active. Differences between the degrees of activity of PIMs and PAMs indicate that these macrophage populations may have different roles in lung surveillance.

Animals↗