In vitro effects of lactoferrin on lipopolysaccharide-induced proliferation, gene expression, and prostanoid production by bovine peripheral blood mononuclear cells

Objective-To evaluate the effect of lactoferrin on lipopolysaccharide (LPS)-induced proliferation of bovine peripheral blood mononuclear cells (PBMCs), gene expression of inflammatory mediators, and production of prostanoids in vitro. Sample Population-PBMCs isolated from 15 Holstein bull calves. Procedures-Mixed populations of PBMCs were isolated by differential centrifugation. Proliferation assays were conducted in 96-well plates designed to allow addition of lactoferrin (200 ng/mL) with and without LPS (1 mug/mL) in a checkerboard design. Incorporation of (3)H-thymidine was used to determine proliferation of PBMCs. Prostaglandin E(2) production was determined in culture-conditioned medium by use of enzyme immunoassay. Effects of lactoferrin on LPS-induced gene expression of cyclooxygenase (COX)-2 and matrix metalloproteinase (MMP)-9 were monitored by use of PCR assays. Results-Lactoferrin supplementation significantly reduced LPS-induced incorporation of (3)H-thymidine and production of prostaglandin E(2) by PBMCs. Lactoferrin reduced LPS-induced expression of COX-2 and MMP-9 mRNA. Conclusions and Clinical Relevance-Lactoferrin reduced LPS-induced cellular proliferation, inflammatory mediator gene expression, and prostaglandin E(2) production by bovine PBMCs in vitro. These effects may be beneficial in reducing the impact of endotoxemia in neonates.     

Quantitative assessment of blood volume, blood flow, and permeability of the brain of clinically normal dogs by use of dynamic contrast-enhanced computed tomography

OBJECTIVE: To determine effects of regional variation, interobserver variability, and vessel selection on quantitative vascular variables derived by dynamic contrast-enhanced computed tomography (DCE-CT) of the brain of clinically normal dogs. ANIMALS: 14 adult dogs with no evidence of CNS dysfunction. PROCEDURES: Dogs were randomly assigned to 4 groups, and DCE-CT was performed at the level of the frontal lobe, rostral portion of the parietal-temporal lobes, caudal portions of the parietal-temporal lobes, or occipital lobe-cerebellum for groups 1 to 4, respectively. Cerebral blood flow (CBF), cerebral blood volume (CBV), and permeability in gray and white matter for both a large and small artery were calculated and compared. Values among 3 observers and 4 regions of the brain were calculated and compared. RESULTS: Significant interobserver variability was detected for CBF and permeability in white matter. Values calculated for large and small arteries were correlated for CBV and CBF but not for permeability. Overall mean +/- SD for CBF, CBV, and permeability in gray matter was 53.5 +/- 27.7 mL/min/100 g, 2.9 +/- 1.4 mL/100 g, and 1.4 +/- 2.2 mL/min/100 g, respectively. Mean for CBF, CBV, and permeability in white matter was 44.2 +/- 28.5 mL/min/100 g, 2.5 +/- 1.5 mL/100 g, and 0.9 +/- 0.7 mL/min/100 g, respectively. Values did not differ significantly among brain regions. CONCLUSIONS AND CLINICAL RELEVANCE: Significant regional variations were not detected for quantitative vascular variables in the brain of clinically normal dogs. However, interobserver variability and vessel selection have an important role in variable estimation.     

Murine cytomegalovirus glomerulonephritis: clinical and ultrastructural observations.

This investigation was initiated to study and correlate the clinical and ultrastructural aspects of glomerulonephritis induced in the laboratory mouse by the intraperitoneal injection of a sublethal dose of murine cytomegalovirus. An attempt was made to ascertain the pathogenesis of the glomerular changes and the resultant viremia. Murine cytomegalovirus infection caused an acute transient glomerulonephritis in young female mice of the HA/ICR strain. Mice that survived a sublethal inoculation of homogenized infected gland developed transient proteinuria and excreted tubular casts. The murine cytomegalovirus infection resulted in a glomerular lesion that was selective for the mesangial cell. After entering the mesangial cell by phagocytosis the virus replicated in the nucleus and was excreted into the channel of the mesangial matrix, with extension toward the periphery of the capillary loop and adjacent to the urinary space. Virus particles were rarely found in the glomerulus after the 5th day of infection and chronic renal disease was not observed.     

Left-handed DNA in vivo

Left-handed DNA is shown to exist and elicit a biological response in Escherichia coli. A plasmid encoding the gene for a temperature-sensitive Eco RI methylase (MEco RI) was cotransformed with different plasmids containing inserts that had varying capacities to form left-handed helices or cruciforms with a target Eco RI site in the center or at the ends of the inserts. Inhibition of methylation in vivo was found for the stable inserts with the longest left-handed (presumably Z) helices. In vitro methylation with the purified MEco RI agreed with the results in vivo. Supercoil-induced changes in the structure of the primary helix in vitro provided confirmation that left-handed helices were responsible for this behavior. The presence in vivo of left-handed inserts elicits specific deletions and plasmid incompatibilities in certain instances.     

Imaging of arsenic Cottrell atmospheres around silicon defects by three-dimensional atom probe tomography

Discrete control of individual dopant or impurity atoms is critical to the electrical characteristics and fabrication of silicon nanodevices. The unavoidable introduction of defects into silicon during the implantation process may prevent the uniform distribution of dopant atoms. Cottrell atmospheres are one such nonuniformity and occur when interstitial atoms interact with dislocations, pinning the dislocation and trapping the interstitial. Atom probe tomography has been used to quantify the location and elemental identity of the atoms proximate to defects in silicon. We found that Cottrell atmospheres of arsenic atoms form around defects after ion implantation and annealing. Furthermore, these atmospheres persist in surrounding dislocation loops even after considerable thermal treatment. If not properly accommodated, these atmospheres create dopant fluctuations that ultimately limit the scalability of silicon devices.     

Thermochemical remanent magnetization and thermal remanent magnetization: comparison in a basalt

Recent studies have shown that the remanent magnetization carried by an extrusive igneous rock may not be entirely thermal remanent magnetization (TRM). Some may be thermochemical remanent magnetization (TCRM) acquired by the rock at temperatures at least as low as 300 degrees C during oxidation of the contained titanomagnetite grains. Results from a study of a set of basaltic samples from one locality indicate that the intensity of TCRM acquired by a sample in a known magnetic field is equal to that of TRM subsequently produced in the same sample in the same field. On the assumption that the samples we studied are not magnetically unique, we tentatively conclude that paleointensity studies are valid in spite of the presence of TCRM, as long as the rock acquired the magnetization during the initial cooling.