Charles F. Stanley

A mathematical description of pressures in alveolar pores of Kohn

Small interalveolar holes within the lung are called pores of Kohn. Some researchers have correlated enlarged pore size with diseases, e.g. emphysema, that are characterized by tissue destruction. Mathematical models of the pressures generated in closed, fluid-filled and open, fluid-lined pores demonstrate that pressures capable of rupturing lung tissue can be developed in a pore due to the surface tension and shape of the air-liquid interface. Pore enlargement accompanied by tissue destruction is presented as a possible mechanism for the disease process observed during aging and the development of emphysema in the lung.

Inhaled Silica Dust Increases Nitric Oxide and Cytokine Production Associated with Collagen Synthesis and Fibrosis in Rats

Abstract The association of silica with pulmonary inflammation and fibrosis is well documented. However, the mediators involved in the pathogenesis of silica-induced pulmonary fibrosis are not completely defined. In parallel studies, which will be summarized in this presentation, intratracheal instillation of silica resulted in nitric oxide production and pulmonary inflammation within 24 hours. The objective of the current study was to determine the involvement of nitric oxide and cytokines in the pathogenesis of inflammation and fibrosis associated with an occupationally-relevant inhaled exposure to silica. Male Fischer rats were exposed by inhalation to 2 mg/m3 of freshly-generated silica for 2 weeks, 2 months, and 6 months at a rate of 5 days/week, 8 hour per day. Cellular differentials, chemiluminescence, and mRNA levels of inducible nitric oxide synthase (iNOS), transforming growth factor β (TGFβ), and platelet-derived growth factor (PDGF) were all measured in cells obtained by bronchoalveolar lavage...

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.

Technique to apply holographic interferometry to excised animal lungs

Frequency analysis of acoustic waves sent into, and reflected from, lung airways is being studied as a possible early indicator of lung disease. To help evaluate the acoustic impedance of the lung, a method has been developed to determine which parts of the surface of an excised lung are responding to the acoustic excitation via the trachea. Holographic interferometry, a very sensitive technique that can measure movements of a few mu m, is being used to detect the lung-surface movement. Lungs from normal guinea pigs are being analyzed. Acoustic waves at selected frequencies are sent into the trachea and a double-exposure holograph is made of the lung. Each exposure is approximately 4 ms in duration with a separation of 2 ms. The laser pulse is obtained by interrupting the beam from a 0.5-w argon ion laser. Fringe patterns produced are an indication of lung movement. Work is continuing to distinguish normal and diseased lungs using a combination of acoustic excitation and holographic interferometric techniques.<<ETX>>

Designing better surgical instruments

Fifteen ergonomic criteria are presented which can produce better surgical instruments and allows surgeons to operate comfortably while minimizing fatigue. All of the bone-cutting instruments analyzed violate one or several of the criteria. Those most commonly violated are identified.<<ETX>>