Efficacy of direct detection of pathogens in naturally infected mice by using a high-density PCR array.

We used a high-density array of real-time PCR assays for commonly reported rodent infectious agents (PRIA) to test naturally infected index mice and sentinel mice exposed by contact and soiled-bedding transfer. PRIA detected 14 pathogens--including viruses, bacteria, fur mites, pinworms, and enteric protozoa--in 97.2% of 28 pooled fecal samples, fur-perianal swabs, and oral swabs from 4 cages containing a total of 10 index mice.

Pathogenicity and genetic variation of 3 strains of Corynebacterium bovis in immunodeficient mice.

Corynebacterium bovis has been associated with hyperkeratotic dermatitis and acanthosis in mice. We studied 3 different strains of C. bovis: one previously described to cause hyperkeratotic dermatitis (HAC), one that infected athymic nude mice without leading to the classic clinical signs, and one of bovine origin (ATCC 7715).

Comparison of traditional and PCR methods during screening for and confirmation of Aspiculuris tetraptera in a mouse facility.

Pinworm detection in laboratory rodents typically is accomplished by using the tape test or various modifications of fecal flotation test to detect eggs. Direct examination of intestinal contents remains the 'gold standard' for pinworm detection, with the limitation of euthanasia of animals. Here, we compare traditional and real-time PCR methodologies during screening for and confirming the presence of Aspiculuris tetraptera.

Assessment of rpoB and 16S rRNA genes as targets for PCR-based identification of Pasteurella pneumotropica.

Diagnosis of Pasteurella pneumotropica in laboratory animals relies on isolation of the organism, biochemical characterization, and, more recently, DNA-based diagnostic methods. 16S rRNA and rpoB gene sequences were examined for development of a real-time PCR assay. Partial sequencing of rpoB (456 bp) and 16S rRNA (1368 bp) of Pasteurella pneumotropica isolates identified by microbiologic and biochemical assays indicated that either gene sequence can be used to distinguish P.

The adenoviral E1A oncoprotein activates the Smad7 promoter: requirement of a functional E-box.

DNA tumorviruses like adenoviruses (AdV) or human papillomaviruses (HPV) have adopted various strategies to interfere with antiproliferative transforming growth factor-beta (TGF-beta) signalling. Here we report that the AdV E1A oncoprotein is sufficient to induce Smad7 expression, an inhibitor of TGF-beta signalling. E1A but not HPV oncoproteins activated the Smad7 promoter.

Inhibition of VEGF or TGF-{beta} signaling activates endothelium and increases leukocyte rolling.

Objective: Motivated by the central roles that vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-beta play in the assembly and maintenance of the vasculature, we examined the impact of systemic VEGF or TGF-beta signal inhibition on endothelial activation as detected by leukocyte-endothelial interactions.

Methods And Results: VEGF or TGF-beta inhibition, accomplished using adenovirus expression of soluble Flt1 (Ad-sFlt1) or soluble endoglin (Ad-sEng), resulted in a significant increase in the number of leukocytes rolling along the mesenteric venous endothelium and a significant decrease in rolling velocity in Ad-sEng mice. Neutralization of VEGF or TGF-beta resulted in endothelial surface expression of P-selectin and impaired peripheral vasodilatation.

Thrombocytopenia and platelet abnormalities in high-density lipoprotein receptor-deficient mice.

Objective: High-density lipoprotein (HDL) receptor, scavenger receptor class B, type I (SR-BI), mediated cellular uptake of lipoprotein cholesterol controls HDL structure and plasma HDL and biliary cholesterol levels. In SR-BI knockout (KO) mice, an unusually high plasma unesterified-to-total cholesterol ratio (UC:TC) and abnormally large HDL particles apparently contribute to pathology, including female infertility, susceptibility to atherosclerosis and coronary heart disease, and anemia. Here we examined the influence of SR-BI deficiency on platelets.

PSGL-1 regulates platelet P-selectin-mediated endothelial activation and shedding of P-selectin from activated platelets.

We have previously shown that activated platelets in circulation stimulate release of endothelial Weibel-Palade bodies thus increasing leukocyte rolling in venules. P-selectin on the activated platelets mediates adhesion to leukocytes via PSGL-1 and is rapidly shed into plasma. We were interested in studying the role of PSGL-1 in regulating expression and function of platelet P-selectin.

Decreased plasma fibronectin leads to delayed thrombus growth in injured arterioles.

Objective: Plasma fibronectin (FN) is decreased in several clinical conditions. We were interested to study the thrombotic and hemostatic consequences of the decrease in plasma FN (pFN), the role of FN splice variants in thrombosis, and to examine whether pFN incorporates into thrombi in vivo.

Methods And Results: We compared the thrombotic response to a vessel injury in FN heterozygous (FN+/-) mice and corresponding FN+/+ mice.

Elevated levels of homocysteine compromise blood-brain barrier integrity in mice.

Elevated levels of plasma homocysteine (Hcy) correlate with increased risk of cardiovascular and Alzheimer diseases. We studied the effect of elevated Hcy on the blood-brain barrier (BBB) to explore the possibility of a vascular link between the 2 diseases. On a hyperhomocysteinemic diet, cystathionine beta-synthase (Cbs)-heterozygous mice develop hyperhomocysteinemia.

Activated platelets induce Weibel-Palade-body secretion and leukocyte rolling in vivo: role of P-selectin.

The presence of activated platelets and platelet-leukocyte aggregates in the circulation accompanies major surgical procedures and occurs in several chronic diseases. Recent findings that activated platelets contribute to the inflammatory disease atherosclerosis made us address the question whether activated platelets stimulate normal healthy endothelium. Infusion of activated platelets into young mice led to the formation of transient platelet-leukocyte aggregates and resulted in a several-fold systemic increase in leukocyte rolling 2 to 4 hours after infusion.

A direct role for C1 inhibitor in regulation of leukocyte adhesion.

Plasma C1 inhibitor (C1INH) is a natural inhibitor of complement and contact system proteases. Heterozygosity for C1INH deficiency results in hereditary angioedema, which is mediated by bradykinin. Treatment with plasma C1INH is effective not only in patients with hereditary angioedema, but also in a variety of other disease models, in which such therapy is accompanied by diminished neutrophil infiltration.

Tumor necrosis factor-alpha-converting enzyme (ADAM17) mediates GPIbalpha shedding from platelets in vitro and in vivo.

Interaction of the platelet receptor glycoprotein (GP) Ib-V-IX with von Willebrand factor exposed at a site of vascular injury is an essential step in the initiation of a hemostatic plug. Proteolytic cleavage (shedding) of the GPIbalpha subunit was first described >25 years ago, the protease mediating this event as well as its physiological function, however, have not been elucidated. We reported recently that shedding of GPIbalpha induced by platelet storage or mitochondrial injury involves a platelet-derived metalloproteinase(s).

Expression of biopterin transporter (BT1) protein in Leishmania.

The present work focuses on the growth phase regulated expression of biopterin transporter gene (BT1) from the LD1 locus on chromosome 35 of Leishmania donovani. Antiserum against recombinant BT1 detected a polypeptide of 45 kDa of equal intensity at lag, log and stationary phases of promastigote growth, both in L. donovani strain LSB-7.