Aerosols, airflow, and more: examining the interaction of speech and the physical environment

We describe ongoing efforts to better understand the interaction of spoken languages and their physical environments. We begin by briefly surveying research suggesting that languages evolve in ways that are influenced by the physical characteristics of their environments, however the primary focus is on the converse issue: how speech affects the physical environment. We discuss the speech-based production of airflow and aerosol particles that are buoyant in ambient air, based on some of the results in the literature. Most critically, we demonstrate a novel method used to capture aerosol, airflow, and acoustic data simultaneously. This method captures airflow data via a pneumotachograph and aerosol data via an electrical particle impactor. The data are collected underneath a laminar flow hood while participants breathe pure air, thereby eliminating background aerosol particles and isolating those produced during speech. Given the capabilities of the electrical particle impactor, which has not previously been used to analyze speech-based aerosols, the method allows for the detection of aerosol particles at temporal and physical resolutions exceeding those evident in the literature, even enabling the isolation of the role of individual sound types in the production of aerosols. The aerosols detected via this method range in size from 70 nanometers to 10 micrometers in diameter. Such aerosol particles are capable of hosting airborne pathogens. We discuss how this approach could ultimately yield data that are relevant to airborne disease transmission and offer preliminary results that illustrate such relevance. The method described can help uncover the actual articulatory gestures that generate aerosol emissions, as exemplified here through a discussion focused on plosive aspiration and vocal cord vibration. The results we describe illustrate in new ways the unseen and unheard ways in which spoken languages interact with their physical environments.

Pharmacologic management of cancer pain

The satisfactory management of pain associated with neoplastic disease is one of the most difficult problems encountered by the clinician. Adequate knowledge of the pathophysiology of pain, the cause and presentation of different pain types, and the mechanisms of action of medications is necessary for sound clinical decisions. Effective pain management has a profound impact on the patient's quality of life and may reduce suffering.

Characterization of extended primary and secondary cultures of hamster tracheal epithelial cells

Studies on the regulation of differentiation in airway epithelial cells have been hampered by the lack of cell culture systems that differentiate in vitro. One such system that does exhibit differentiation is hamster tracheal epithelial cells (HTE). A major problem with this system, however, is that at the time cells differentiate, they lyze the collagen gel upon which they grow, resulting in termination of the culture. Here we report that by growing the HTE cells at 32 degrees instead of 37 degrees C we can totally prevent lysis of the collagen gel. Cells grown at this lower temperature maintain their differentiated phenotype as evidenced by abundant mucus granules and the secretion of authentic mucus glycoproteins into the culture media. We have also developed a method for subculturing the primary cells which allows growth and differentiation in secondary culture. The HTE cells were capable of being passaged at least three times and did not become transformed as judged by their inability to grow in soft agar and to produce tumors in syngeneic animals. This improved HTE cell culture system will allow detailed studies on the mechanisms which regulate growth, differentiation, and mucus secretion in surface airway epithelial cells.

Temperature-dependent alteration of cellular morphology by cholera toxin in rat liver epithelial cells which are ts for maintenance of transformed properties

Cholera toxin via its ability to increase intracellular cyclic AMP levels can induce drastic changes in cell morphology. This report describes a temperature sensitive mutant of chemically transformed rat liver epithelial cells which only display cell shape alterations in response to cholera toxin at the permissive temperature. Shift up-shift down experiments indicate that the change in the response occurs fairly rapidly, i.e., within 2 hours at the new temperature. The behavior of the temperature sensitive cells at the nonpermissive temperature mimics that of the untransformed rat liver epithelial cells (i.e., no morphological change in response to cholera toxin) while at the permissive temperature the positive cell shape change is identical to that exhibited by chemically transformed rat liver epithelial cells. The temperature sensitive response to cholera toxin is not a function of cyclic AMP production, since the amount of cyclic AMP found as a function of either time or concentration of cholera toxin is quite similar in cells treated at either temperature.

Characterization of collagen synthesized by normal and chemically transformed rat liver epithelial cell lines

A rat liver epithelial cell line (K16) and a 2-[N-(acetoxyacetyl)amino]fluorine-transformed K16 cell line (W8) [Weinstein, I.B., Yamaguchi, R., Gerbert, R., & Kaighn, M.E. (1975) In Vitro 11, 130-141] synthesize and secrete similar quantities of collagenous proteins. The transformed cells produce more total protein so that the percent collagen produced is decreased compared to that of the parent cell line. The type of collagen produced by the transformants differed from that of the parent cell line. After limited pepsin digestion, the pepsin-resistant collagen molecules synthesized by K16 cells precipitated at 2.6 M NaCl and contained both alpha 1 (I) and alpha 2 chains in a 2.5:1 ratio. The collagen synthesized by the W8 cells precipitated at higher salt concentrations, and no pepsin-resistant alpha 2 chains could be demonstrated by CM-cellulose chromatography or gel electrophoresis. The cyanogen bromide peptides of the W8 alpha 1 chains did not cochromatograph with type I rat skin collagen cyanogen bromide peptides on CM-cellulose chromatography, whereas the alpha 1 chains of the K16 cells did cochromatograph. The conversion of procollagen to collagen was also decreased in the transformant cells. Therefore, the chemical transformation of K16 produced transformants with increased protein synthesis and altered collagen metabolism.