Biomedical subjects

C F Stanley

Publications and source records attributed to C F Stanley.

6 recordsLinked to original sources

PubMed2001

Immunoglobulin responses to experimental silicosis.

Silicosis is a crippling fibrotic lung disease induced by inhalation of crystalline silica. One feature of silicosis is systemic and pulmonary immune dysfunction characterized in part by elevations in serum and bronchoalveolar lavage (BAL) immunoglobulins. A major specific aim of the current report was to demonstrate that an experimental model of silicosis previously well characterized for the development of pulmonary inflammation and fibrosis would also exhibit increased levels of serum and BAL IgG and IgM similar to those of human silicosis. We also sought to document the anatomic compartments responsible for these immunoglobulin responses. To address these specific aims, we compared levels of IgG and IgM in serum and BAL from rats with experimental silicosis induced by inhalation of silica with levels of these immunoglobulins in titanium dioxide (TiO(2))- and sham (air)-exposed controls. The ability of mononuclear cell populations from lung, lung-associated lymph node, and spleen to produce IgG and IgM ex vivo were also compared. We found that experimental silicosis was associated with elevated IgG and IgM levels in blood and BAL relative to the control groups. Our findings also suggested that draining lung-associated lymph nodes (LALN) were the most important sites for increased IgG and IgM production in experimental silicosis, with lungs contributing to a lesser degree. Increased production in the LALN appeared related to marked expansion in total numbers, but not relative proportion, of B lymphocytes.

Administration, Inhalation↗

PubMed2001

Protonation of tetrasulfonated zinc phthalocyanine in aqueous acetonitrile solution.

The phenomenon of protonation of phthalocyanines (Pc) and its effect upon their photophysical properties has seen considerable neglect in the literature. The work reported here clearly shows that tetrasulfonated zinc Pc, a known photodynamic therapy (PDT) agent, is strongly susceptible to protonation at the azomethine bridges. Absorption and fluorescence spectra demonstrate the absolute dependence of the redshifted peak on the pH of the solution. The fluorescence spectra and lifetimes of the protonated Pc are reported, and the potential application of this phenomenon to the development of a PDT agent with increased selectivity is discussed.

Journal Article↗

PubMed2001

IgG subclass responses in experimental silicosis.

Silicosis is a crippling fibrotic lung disease induced by inhaling crystalline silica. In addition to fibrosis, silica inhalation by humans is associated with a number of immunological effects including increased levels of serum immunoglobulins (in particular IgG), increased prevalence of autoantibodies, and autoimmune disease. Recent studies using rodent models have shown that experimental silicosis is associated with a T-helper (TH)1 pattern of T-cell activation in the lungs and lung-associated lymph nodes after silica inhalation, which are also the sites of increased IgG production. We therefore hypothesized that the subclass distribution of IgG production occurring in experimental silicosis would suggest TH1 activation as the primary stimulus for IgG production. Using an ELISPOT assay, we found increased IgG-secreting spot-forming cells of all IgG subclasses in lung-associated lymph nodes taken from silica-exposed rats 3 to 4 months after aerosol exposure to silica. Neither TH1- nor TH2-dependent IgG subclass-secreting cells were selectively enhanced. Our findings suggest that TH1 activation alone does not account for increased production of IgG in experimental silicosis.

Administration, Inhalation↗

PubMed1993

A methodology to assess the upper extremity strength in a chair egress posture.

In this paper a method is presented which can be used to analyse the force distribution resulting from the application of force on the left and right armrest of a chair during the action of sitting down or standing up. The peak data for both hands can be combined to obtain the maximum for a trial on a specific chair configuration. This method is useful to assess the upper extremity limitations of an elderly or disabled population when rising from a seated position. The method involved the instrumentation, with strain gauges, of armrests of a prototype lounge chair obtained from a manufacturer of seating for the elderly. Provision for hand placement was included and the system was appropriately calibrated. The methodology presented may have a variety of applications, such as the assessment of seating requirements for the elderly or disabled, and the relative evaluation of a range of seats for nursing homes, clinics, hospitals and rehabilitation or recreational lounges.

Journal Article↗

PubMed1990

Effect of in vivo coal dust exposure on arachidonic acid metabolism in the rat alveolar macrophage.

Oxygenated metabolites of arachidonic acid (AA) are produced by the alveolar macrophage (AM) and have been shown to mediate inflammatory reactions. We therefore assessed the production of eicosanoids by AM harvested from the lungs of rats exposed to a bituminous coal dust for 2 wk in an inhalation chamber in order to determine if AA metabolism was altered in a manner that may promote an inflammatory response in the lung. Exposure to coal dust resulted in a 66% increase in the number of AM harvested, an increase in thromboxane A2 (TxA2) and leukotriene B4 (LTB4) production to 222% and 181% of control values, respectively, and a decrease in prostaglandin E2 (PGE2) production to 62% of control values. In AM harvested from rats allowed to breath clean air for 2 wk following coal dust exposure, PGE2 production returned to control levels but TxA2 and LTB4 production remained elevated. The TxA2 synthesis inhibitor UK 38,485 reduced TxA2 production in dust-exposed AM both immediately and 2 wk following exposure. Thus, exposure of rats to coal dust significantly alters the metabolism of AA in AM, with potentially important aspects of AA metabolism remaining altered even after a 2-wk recovery period. Based on the established role of eicosanoids in inflammatory and fibrotic processes, these results suggest that the alteration of AM eicosanoid production as a result of the inhalation of coal mine dust may be an important factor in the pathophysiology of coal workers' pneumoconiosis.

Animals↗

PubMedDate not supplied

Instrument to test patency of lacrimal drainage system.

The lacrimal drainage system drains fluid that exists normally on the surface of the eye into the nasal cavity. This paper describes a hand-held, personal-computer-based instrument to quantitatively estimate the resistance to fluid flow through the lacrimal drainage system. This resistance measurement is proposed as a possible means to diagnose blockage of the system and to verify the degree of change in resistance after clinical treatment. The instrument system consists of a hand-held syringe attached to pressure and flow transducers. Resistance is calculated as the ratio of differential pressure to flow rate and is displayed in real time on a computer monitor.

Biomedical Engineering↗