Neonatal and mature bovine lungs were examined ultrastructurally to quantitatively assess pericyte envelopment of gas exchange capillaries and proximities of pericyte margins to endothelial cell junctions. Pericytes were observed on 91% of the cross-sectioned capillary profiles examined, with 18 and...

The leakage of macromolecules from the vasculature to the interstitium is greatly accentuated by mediators of edema such as histamine and bradykinin. The mechanism for this effect is not well delineated although many agents that affect smooth muscle tone may also affect macromolecular leakage. Leaka...

Inability to preserve airway mucus in situ has limited our understanding of its structure and function. This light- and transmission electron-microscopic study of rat tracheal mucus used a nonaqueous fixative that retains mucus (epiphase) over a lucent layer (hypophase). The fixative is a 1% solutio...

Monastral blue (MB) has been described as an inexpensive, nontoxic vascular label. Discrepancies as to its rate of removal from circulation and physiological side effects prompted this study in which retention time of MB in the vascular system and effects of MB upon arterial blood pressure with diff...

This review highlights the contributions of recent pericyte research towards our understanding of normal and pathological functioning of microvessels. Pericytes are implicated in a variety of microvascular alterations, including wound healing, diabetes, inflammation, hypertension and neoplasia. They...

A fixative composed of 1% w/v osmium tetroxide dissolved in a tluorocarbon (FC-72) was used to perfusion-fix rat blood vessels for this ultrastructural study. With non-aqueous fixation, the lumenal surfaces of endothelial cells in cardiac and skeletal muscles retained an extracellular coat which was...

Domoic acid is a neurotoxic amino acid responsible for an outbreak of human food poisoning in late 1987 following consumption of contaminated blue mussels (Mytilus edulis L.) from eastern Prince Edward Island, Canada. In vitro techniques were used to examine the uptake of domoic acid by digestive gl...

Glutamic acid (GA) and kainic acid (KA) are structurally related to domoic acid (DOM), a neurotoxic amino acid that caused human food poisoning in 1987, following consumption of toxic mussels (Mytilus edulis ) from Prince Edward Island, Canada. To study the difference in response of mussels to a phy...

Interleukin-2 (IL-2) mediates regression of metastatic cancer, but its therapeutic efficacy has been limited by toxicities which occur secondarily to IL-2 induced macromolecular leakage from microvessels. Previous studies have indicated that pericytes function in an endothelial cell junction-depende...

Immunotherapy with interleukin-2 (IL-2) is limited by severe side effects thought to be mediated by the activation of immune effector cells and the induction of secondary cytokines including tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). In C3H/HeN mice the primary IL-2 to...

OBJECTIVE: To determine the acute anti-inflammatory effects of topically applied emu oil. ANIMALS: 96 male CD-1 mice assigned randomly to 4 groups, each comprising 24 mice. PROCEDURE: To induce auricular inflammation, 50 microl of a solution comprising 10 microl of croton oil dissolved in 1 ml of ac...

Tumor necrosis factor-alpha (TNF-alpha), a central mediator in the hemodynamic response to injury and infection, is a primary mediator of endotoxin-induced hemodynamic instability. Two types of naturally occurring soluble TNF receptors circulate in human experimental endotoxemia and the recombinant ...

The ultrastructure and orientation of microfilament-attaching junctions between pulmonary fibroblasts (also known as myofibroblasts or contractile interstitial cells) of bovine lung septa were investigated by transmission electron microscopy. Adhering junctions similar to the fascia adherens of the ...

The toxin-producing diatom Nitzschia pungens Grunow forma multiseries Hasle from three toxic blooms in two Prince Edward Island estuaries, spanning 1987-89, was studied using light and electron microscopy. Cell ultrastructure of N. pungens is, in general, similar to that of other species of Nitzschi...

Fibroblasts in the pulmonary alveolar septa of neonatal and mature cattle form spot-shaped intercellular junctions with each other where 6 nm microfilaments adhere to the plasma membranes. The junctions have variable cleft widths (10-20 nm) and a diffuse periodic intracleft substance. Impinging 6 nm...

Tumor necrosis factor-alpha (TNF-alpha) has been implicated as an important mediator in the development of multiple system organ failure after either severe injury or infection. Using the rat cremaster muscle, we previously showed that systemically administered TNF-alpha caused hypotension, tachypne...