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...

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...

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...

The study of teamwork has been fragmented through the years, and the findings are generally unable to be used practically This article argues that it is possible to boil down what researchers know about teamwork into five core components that the authors submit as the "Big Five" in teamwor...

Administration of interleukin-2 (IL-2) for treatment of metastatic disease often results in inflammatory liver injury. Previous studies have implicated increased leukocyte and platelet adhesion and enhanced nitric oxide production as causative factors in the development of IL-2-induced hepatic injur...

Activation of photosensitive compounds has been used in the treatment of tumors and as a technique to study various microcirculatory phenomena. This technique may be accompanied by deleterious effects which may complicate interpretations of experimental results. However, the relevant physiological m...

Matrix metalloproteinases (MMPs) are traditionally known for their role in extracellular matrix remodeling. Increasing evidence reveals several alternative substrates and novel biological roles for these proteases. Recent evidence showed the intracellular localization of MMP-2 within cardiac myocyte...