Changes in alveolar lavage materials and lung microsomal xenobiotic metabolism following exposures to HCl-washed or unwashed crystalline silica.

Intratracheal exposures of rats to crystalline silica washed with HCl to remove iron contaminants have previously been shown to increase lung surfactant phospholipids (PL) and proteins and to alter the pulmonary microsomal cytochrome P450 system. We compared these effects of HCl-washed silica with those produced by exposures to unwashed silica and alumina. Both silica preparations produce increases in lung weights and alveolar lavage PL and proteins, but to different degrees. The increases produced by HCl-washed vs unwashed silica are lung weights, 2.2- vs 1.3-fold; lavage PL, 25.9- vs 3.7-fold; and lavage proteins, 11.1- vs 3.2-fold, respectively. Although the two silica particles increase lung microsomal protein concentrations (expressed per gram lung) by 50-60%, their effects on cytochrome P-450-mediated xenobiotic metabolism are quite different. Exposure to HCl-washed silica leads to a 2.3-fold increase in 7-ethoxyresorufin O-deethylation, a reaction catalyzed by cytochrome P4501A1, and a 0.5- to 0.6-fold reduction in 7-ethoxycoumarin O-deethylation, a reaction which may be catalyzed by cytochrome P-4502B1. Unwashed silica does not alter the metabolism of either xenobiotic when results are expressed per milligram microsomal protein. Administration of alumina produces only minor increases in lung weight and lavage PL and no effect on microsomal xenobiotic metabolism. These results show that the increases in alveolar lavage PL and proteins induced by administration of unwashed silica are exaggerated by 3- to 7-fold if the silica is treated with HCl. Furthermore, exposure to HCl-washed silica results in significant alterations of the lung microsomal cytochrome P450 system, but the unwashed silica has little effect. Although the reason(s) for these different effects is not known, measurements of iron levels and formation of hydroxyl radicals using ESR demonstrate that there is more iron associated with the unwashed than with the HCl-washed silica.

Nonverbal and verbal emotional expression and health.

The spontaneous nonverbal expression of emotion is related to immediate reductions in autonomic nervous system activity. Similar changes in specific autonomic channels occur when individuals are encouraged to verbally express their emotions. Indeed, these physiological changes are most likely to occur among individuals who are either verbally or nonverbally highly expressive. These data suggest that when individuals must actively inhibit emotional expression, they are at increased risk for a variety of health problems. Several experiments are summarized which indicate that verbally expressing traumatic experiences by writing or talking improves physical health, enhances immune function, and is associated with fewer medical visits. Although less research is available regarding nonverbal expression, it is also likely that the nonverbal expression of emotion bears some relation to health status. We propose that the effectiveness of many common expressive therapies (e.g., art, music, cathartic) would be enhanced if clients are encouraged to both express their feelings nonverbally and to put their experiences into words.

Accuracy in social perception: contributions of facial and vocal information.

The validity of social perceptions was assessed on the basis of facial or vocal information. Specifically, impressions of stimulus persons' power and warmth were obtained on the basis of either a facial photograph or a voice recording. These were compared with the stimulus persons' self-reports along the same dimensions. Face- and voice-based impressions did predict self-view. The specific facial and vocal characteristics that mediated these links were also considered. Potential mechanisms that may yield the match between self-perceptions and impressions based on nonverbal cues are discussed.

What can a moving face tell us?

This research assessed the impact of facial motion on perceptions of age-related person qualities. Ss judged the power of point-light displays of the faces of children, middle-aged adults, and elderly adults. Ratings were obtained of (a) dynamic displays filmed while the stimulus persons were reciting the alphabet, (b) dynamic displays filmed, while the stimulus persons engaged in an interaction, and (c) static versions of the displays. Facial age exerted no effect on the perceived power of nondynamic displays. However, moving displays of children's faces were judged to be less powerful than were those of adults. Differences in perceived age could not explain these effects. The implications of these data for the developing area of social event perception are discussed.

Changing legal standards for proof of causation in hazardous waste tort cases. Plaintiffs' problems and congressional responses.

Increasing public awareness and concern over the possible dangers of exposure to toxic chemicals and hazardous wastes has resulted in a variety of lawsuits brought by plaintiffs claiming injury resulting from chemical exposure. The legal system and its traditional approach to tort cases demands that a plaintiff demonstrate that a particular chemical substance was the "cause in fact" of his injury. However, a plaintiff's inability to present credible scientific evidence sufficient to pinpoint conclusively the specific cause of his injury or disease, particularly in cancer cases, leads to defeat in courts of law. This article discusses the existing barriers to plaintiffs' recovery in toxic tort cases and reviews congressional proposals designed to ease plaintiffs' evidentiary burden and increase their chances of prevailing.