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L S Hinckley

Publications and source records attributed to L S Hinckley.

5 recordsLinked to original sources
PubMed1999

Inducible and constitutive in vitro neutrophil chemokine expression by mammary epithelial and myoepithelial cells.

Previously, our laboratory showed that bovine and caprine mammary secretions are chemotactic and that chemoattractants found in these secretions are qualitatively different according to infection status and/or lactation stage. However, the cellular source of the chemoattractants has not been defined. In this study we used a modified Boyden chamber assay to examine the ability of previously established caprine mammary epithelial cell (CMEC) and myoepithelial cell (CMMyoEC) lines to produce chemoattractants for neutrophils. We found that CMEC culture supernatants, but not those of CMMyoEC cultures, induced in vitro neutrophil chemotaxis. Further characterization showed that chemotactic activity was produced when the cells underwent contact-induced differentiation. Neutrophil migration was chemotactic, not chemokinetic, and was augmented when the epithelial and myoepithelial cells were cocultured. Additionally, chemotactic activity was inducible by Staphylococcus aureus plus alpha-toxin, Escherichia coli, and interleukin-1beta (IL-1beta) in CMEC cultures. However, CMMyoEC cultures could not be induced to produce chemotactic activity. Anti-IL-8 antibody was able to block some constitutively produced chemotactic activity and chemotactic activity induced by IL-1beta and S. aureus plus alpha-toxin. These results indicate that epithelial cells may play a major role in producing chemoattractants, specifically IL-8, in the mammary gland.

Animals↗
PubMed1998

Physiologic-chemoattractant-induced migration of polymorphonuclear leukocytes in milk.

The somatic cell count (SCC; leukocytes and epithelial cells) in milk is used as an indicator of udder health status. A SCC above the regulatory standard is generally considered as an indication of mastitis. Therefore, milk with a SCC equal to or greater than the regulatory limit cannot be sold to the public because it is unsuitable for human consumption. This study was performed to determine whether SCC levels above the regulatory limit observed in goats during late lactation are a physiologic or a pathological response of the goat mammary gland. Differential counts of cells in nonmastitic goat milk samples during late lactation revealed that approximately 80% of the cells were polymorphonuclear leukocytes (PMNs). In addition, microchemotaxis assay results indicated that normal nonmastitic late-lactation-stage goat milk is significantly higher (P < 0.001) in PMN chemotactic activity than early-lactation-stage goat milk, with a mean chemotactic activity of 14.9 and 42.7/mg of protein for early and late lactation stages, respectively. Physicochemical analyses also suggest that the PMN infiltration observed in normal late-lactation-stage goat milk is due to a PMN chemotactic factor(s) that is different from the PMN chemotactic factor(s) present in mastitic milk. Interestingly, the PMN chemotactic factor in late-lactation-stage goat milk is highly acid resistant (pH 2), suggesting that the factor is able to survive the highly acidic gastric environment and may therefore be important in the augmentation of the immune systems of sucklings. These results indicate that the chemotactic factor(s) present in the milk of normal late-lactation-stage goats is nonpathological and may play a physiologic regulatory role in mammary gland involution. Hence, the regulatory standard for goat milk needs to be redefined in order to reflect this.

Animals↗
PubMed1985

Antibiotic susceptibility profiles for mastitis treatment.

Susceptibility tests were performed on milk samples representing prevalent mastitis infections in certain herds. Susceptibility patterns of the same bacterial species from several mastitis infections in the same herd were consistent. The herd antibiotic susceptibility profiles were used as a basis for selecting antibiotics for treatment of all such mastitis cases in that herd. A high degree of correlation was seen between the susceptibility test results and treatment results. Susceptibility patterns of the same bacterial species from mastitis infections in different herds varied greatly, which indicated that any one antibiotic would not work equally well against the same bacterial infection in every herd. Therefore, treatment should be selected on the basis of susceptibility test results. When both Streptococcus and Staphylococcus mastitis occurred in the same herd, the susceptibility patterns for the 2 bacterial species varied widely. Therefore, for herds that experienced both streptococcal and staphylococcal mastitis, antibiotics to which both bacterial species were susceptible were used for treatment.

Ampicillin↗