M. Baarsch - Academia.edu (original) (raw)

Papers by M. Baarsch

The Journal of biological chemistry, Jan 7, 1994

Interleukin (IL)-8 is a macrophage-derived neutrophil chemotactic factor that plays an important ... more Interleukin (IL)-8 is a macrophage-derived neutrophil chemotactic factor that plays an important role in the recruitment of neutrophils to inflammatory loci. Hence, expression of IL-8 by alveolar macrophages may be a significant factor in host defense in the lung and in the pathogenesis of pneumonia in swine. To initiate molecular studies of IL-8 regulation in pigs, we cloned IL-8 cDNA and examined the regulation of its mRNA in alveolar macrophages. The porcine IL-8 cDNA consists of 1491 base pairs including a coding region of 309 base pairs. The deduced amino acid sequence was 75 and 81% similar to human and rabbit IL-8, respectively. Resting macrophages contained low levels of IL-8 mRNA, which increased markedly after exposure to bacterial lipopolysaccharide (LPS). LPS induction of IL-8 was direct, not mediated through elevation of tumor necrosis factor or interleukin-1. The effect of LPS on IL-8 expression was dose dependent, and induction was observed at a concentration of 10 pg...

American journal of veterinary research, 1993

An ELISA-based method to estimate hemagglutination-inhibition (HI) titer was developed. Subtype s... more An ELISA-based method to estimate hemagglutination-inhibition (HI) titer was developed. Subtype specificity was obtained by using purified H1 and H3 hemagglutinin antigens. Using the linear relation that exists between ELISA and HI methods, regression lines for H1N1- and H3N2-monospecific porcine antisera were constructed. Approximation of actual HI titer could be obtained from insertion of ELISA values into the appropriate regression line. The HI estimations were within 50% of the actual measured HI value 84% of the time. In young pigs that had suckled immune sows, use of this ELISA revealed estimated HI titer > 320 at 2 and 4 weeks of age. After a typical farm outbreak of influenza A/swine (H1N1), estimated HI titers remain high for 4 to 6 months. Sub-type-specific estimation of the distribution frequency of positive influenza A (H1N1 or H3N2) results for sera from swine in regional herds indicated that 31.3 and 7.4% of the swine tested were positive (HI > 41) for H1N1 and H...

Journal of leukocyte biology, 1994

Inflammatory cytokines, including interleukin (IL)-1 alpha, IL-1 beta, IL-8, and tumor necrosis f... more Inflammatory cytokines, including interleukin (IL)-1 alpha, IL-1 beta, IL-8, and tumor necrosis factor alpha (TNF-alpha) are produced by macrophages in response to a variety of pathogenic stimuli. We show here that the expression of inflammatory cytokines is suppressed by IL-4 at the transcriptional level. Interleukin-4, when added together with bacterial lipopolysaccharide (LPS), suppressed LPS-induced increases in mRNA levels of IL-1 alpha, IL-1 beta, IL-8, and TNF-alpha in alveolar macrophages. The level of suppression was dependent on dose and time of exposure and reached a maximum of 75-80% of uninduced values for IL-1 alpha, IL-8, and TNF. Interleukin-1 beta expression was completely inhibited by IL-4. The amount of secreted protein, as determined by TNF-alpha bioassay, was also suppressed by IL-4. Half-maximal suppression occurred at IL-4 concentrations between 0.02 and 0.1 ng/ml for all inflammatory cytokines. Nuclear run-on assays showed that IL-4 suppressed transcriptional...

Infection and immunity, 1995

An Actinobacillus pleuropneumoniae infection model in swine was established to study the expressi... more An Actinobacillus pleuropneumoniae infection model in swine was established to study the expression of inflammatory cytokines during acute respiratory disease. Lavage fluid, lavage cells consisting primarily of alveolar macrophages, and lung tissue were analyzed for the presence of various cytokines at 2, 4, 8, and 24 h following endotracheal inoculation of A. pleuropneumoniae. Interleukin-1 beta (IL-1) and IL-8 mRNA levels were elevated within 2 h in lavage cells of animals inoculated with A. pleuropneumonia but not in cells from controls treated with saline-bovine serum albumin, based on Northern (RNA blot) analysis. Tumor necrosis factor (TNF) mRNA was present at low levels in all animals, and the level was not increased at any time point. In situ hybridization was more sensitive than Northern blotting and revealed elevations of all three cytokines in lavage cells within 2 to 4 h of A. pleuropneumoniae inoculation. IL-6 was detected in lavage cells by in situ hybridization but no...

Journal of Veterinary Medicine, Series B, 2000

Severe weight loss in the absence of respiratory, enteric or systemic clinical discase or gross p... more Severe weight loss in the absence of respiratory, enteric or systemic clinical discase or gross pathologic lesions is often observed when immunologically naive boars are placed in conventional health swine facilities. Affected animals develop this weight loss in spite of receiving pre-entry vaccinations against common swine pathogens, such as Haem?pbiLu.r parmuis or hlyopJusnia /jj~opneumoniur. In many cases, the weight loss is non-responsive to long tern1 antibiotic therapy. In order to determine the relationships between the sevcrity of post arrival weight loss and disease and its potential immunological or physiological indicators, tumour necrosis factor (TNFJ and acute phase reactant levels were correlated with the clinical status in immunologically naive boars following their transfer to a conventional facility. Roars had higher T N F (l? < 0.0001) and plasma protein ( I ' = 0,0054) levels and decreased zinc (l? = 0.0004) levels during periods of clinical sickness. Likewise, peak and average plasma TNF, serum haptoglobin, and serum zinc were correlated indicating a prolonged stress or pathogenic insult (r = 0.89, P < 0.0001 for TNF; r = 0.67, P = 0.01 for haptoglobin; r = 0.73, P = 0.005 for zinc). An acute phase response, a systemic T N F increase and the development of a lymphopenia were observed in post arrival disease in swine. This is the first time cytokines and acute phase reactants have been investigated in a field study involving immunologically naive or high health swine.

Animal Biotechnology, 1998

Various "housekeeping" genes are often used as endogenous controls in gene expression experiments... more Various "housekeeping" genes are often used as endogenous controls in gene expression experiments. We have cloned from swine, three genes commonly used as endogenous controls in other species and have characterized their relative levels of expression in various porcine tissues and their response to various cell activators. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and l3-actin were readily detected by northern hybridization in various tissues and in alveolar macrophages. The expression of hypoxanthine phosphoribosyltransferase (HPRT) was detected only by northern hybridization of poly-A+ enriched RNA and by reverse transcriptase-polymerase chain reaction (RT-PCR), making it more suitable for highly sensitive detection methods. Expression of GAPDH varied less among tissues than did l3-actin,making it more useful control for comparisons of gene expression between tissues with northern hybridizations. Various treatments of cultured alveolar macrophages differentially affected levels of l3-actinand GAPDH, while HPRT expression was unchanged in alveolar macrophages or spleen cells similarly treated. Therefore, while HPRT can be used as the endogenous control with sensitive detection methods such as RT-PCR, less sensitive detection methods require a more abundant gene such as GAPDH.

Journal of Virological Methods, 1993