Stratum corneum chymotryptic enzyme (SCCE) is a recently discovered human serine proteinase that may be specific for keratinizing squamous epithelia. SCCE has properties compatible with a function in the degradation of intercellular cohesive structures during stratum corneum turnover and desquamation. SCCE is expressed in suprabasal keratinocytes. In this study, we demonstrate the subcellular localization of SCCE in the upper granular layer, in the stratum corneum of normal non-palmoplantar skin, and in cohesive parts of hypertrophic plantar stratum corneum, using immunoelectron microscopy of ultrathin cryosections labeled with SCCE-specific monoclonal antibodies detected with gold-labeled secondary antibodies. A narrow zone close to the transition between the granular and cornified layers showed positive SCCE staining after fixation. By means of immunoelectron microscopy, SCCE was found in association with structures resembling intracellular lamellar bodies in the uppermost granular cells and in similar structures undergoing extrusion to the extracellular space between the uppermost granular cells and the lowermost cornified cells. In the stratum corneum, the detected SCCE was confined to the extracellular space and was found in association with intact and partially degraded desmosomes, as well as in the parts of the extracellular space devoid of desmosomes. We conclude that SCCE may be stored in lamellar bodies in the stratum granulosum and transported via these structures to the stratum corneum extracellular space. The results further support the idea that the physiologic function of SCCE may be to catalyze the degradation of desmosomes in the stratum corneum during remodeling of the deeper layers of this tissue, and at a later stage serve as a prerequisite for desquamation.

Stratum corneum chymotryptic enzyme (SCCE) is a recently discovered serine proteinase, which has been purified from human plantar stratum corneum. Evidence has been presented that it may play a role in the terminal stages of epidermal turnover, especially in desquamation. Two mouse monoclonal antibodies (MAb) were raised, TE4b and TE9b, that reacted spe&cally with SCCE in immUnoprecipitation, immunoblotting, and gel-exclusion chromatography. When used in immunohistochemical experiments with the peroxidase-anti-peroxidase method, both MAb detected an antigen located in high suprabasal keratinocytes of the epidermis in normal human skin and at the vermilion border of the lip, with maximal staining of the stratum granulosum. In the hair follicles the MAb reacted with the inner root sheet only. In human oral mucosa the MAb stained the high suprabasal epithelial cells of the hard palate. This is a site where the epithelium forms an orthokeratotic stratum cor-

Falls and fall-related injuries are a major problem for elderly persons. Most falls occur during walking and turning, and the risk of falling increases when attention is diverted to something besides walking. It is often difficult to standardize methods for testing balance and fall tendency in a clinically relevant setting. We describe the development of a system using a virtual environment (VE) to assess how attention demanding and unexpected events influence a person's capacity to control balance and movement. The hardware in the system consists of a head-mounted display (HMD), a magnetic tracker system, and two SGI computers. The software consists of the image generation of the VE and the management and visualization of motion tracking data. In a preliminary pilot study eight subjects (age 23-80) participated. Each subject walked on a normal floor and was visually presented a familiar outdoor environment in the HMD. They were exposed to different unexpected events, such as a virtual snowfall and tilting of the VE. Disturbances of balance and walking patterns such as changes in speed, stride length and balance reactions like slipping were observed. Two subjects experienced symptoms of cyber sickness with a SSQ score above 25 points. Walking with sensors only did not affect walking time, but in VE the subjects generally walked more slowly. Virtual tilting of the environment had an impact on balance performance during walking. This effect was not observed while the test subjects were walking in a virtual snowfall. The model needs further development but may hold a potential for clinical use.

Falls and fractures among elderly persons constitute a major health problem. Many falls occur while walking and falls that occur during turning often result in a fracture. Methods aimed at understanding the complex mechanisms involved in walking should therefore assess tested individuals during walks and turns. In order to identify persons at risk and take the correct preventive measures, it is important to find methods that quantify movements as the tested persons are processing multisensory input. In a clinical setting this is sometimes difficult to achieve in a controlled manner, since tests are difficult to set exactly the same from one time to another. Using a virtual environment (VE) and a tracker system, conditions such as light, sound, events, body movements, and room size can be controlled and measured. Tests in VE can therefore be identically reproduced over and over again to evaluate if a person can withstand changing outer demands at any given moment. In order to perform quantitative measures 8 persons (21-74 years) were tested in immersive virtual reality. The VE was a corridor in which expected and unexpected events could be produced. Events studied were doors swinging open in front of the subjects during a walk and a virtual tilting of the environment. Trackers were used for collecting and analyzing the movement data. Our results show that the system was well tolerated among the subjects and that there was a clear tendency that the system could generate fall tendency among the subjects. There was also a difference among the subjects regarding walking strategies when subjected to the various events.

The primary goal of this research was to study the possibility of a virtual environment (VE) to influence empathy on caregiver personal. In the present explorative study, nine subjects from Norrlands University Hospital (NUS) completed a test consisting of three everyday tasks-reading a newspaper, filling a glass of water, and putting toothpaste on a toothbrush. The procedure was done twice, first from a non-stroke perspective and second, from a perspective of a patient with stroke handicaps. The VE looked like a normal apartment and could be experienced with or without different perceptual disorders of stroke. The data from interviews and observations were analyzed via methods inspired by the Grounded Theory. The results from observations and interviews indicated that the simulator, despite problems of usability, was effective in influencing the caregiver's empathy.