Development of unique instrumentation often using novel approaches is, in many instances, a necessary attribute to the success of biomedical research. Areas of emphasis are summarized below.? ? Digital Video EEG Imaging System with Seizure Detection for Multiple Small Animals: The system, being developed in collaboration with Dr. Michael Rogawski and Dr. Maciej Gasior NINDS, will detect and record seizures of small animals by monitoring their EEG together with documenting their accompanying behavior via video recording. The instrumentation consists of animal cages, swivel connectors connected to the head of each animal, EEG analog amplifiers, computer control with movie maker and graphics hardware, and software detection of spikes and seizure patterns. The system has been assembled and will visually display and record EEG data along with video of multiple small animals. The instrument has been tested on small animals and modifications have been made to the mechanical apparatus to allow for more flexible animal movement. The system will continue to be updated as the latest software changes become available. ? ? Electronic Instrumentation for flash photolysis of Microsomal P450: In collaboration with Dr. Fred Friedman, NCI, a laser flash photolysis apparatus was developed to measure the kinetics of carbon monoxide (CO) binding to cytochromes P450 in liver microsomes from rats treated with various drugs and carcinogens. Since numerous forms of P450 contribute to the overall reaction, a difference kinetic method was used to distinguish the kinetic behavior of individual P450s. This method entails analysis of the difference between the kinetic profiles in the absence and presence of a specific P450 effector, and successfully yielded kinetic parameters for individual P450s involved in drug and carcinogen metabolism. Specifically, various polycyclic hydrocarbons differentially accelerated CO binding to the P450 1A1, which metabolizes these carcinogens in a size and shape dependent manner. Wavelet analysis allows selection of critical short time scale regions where high frequency information predominates and provides information on the early events associated with the cytochrome P450 binding kinetics. The use of the Mathlab wavelet module has been studied for use in this system. ? ? In collaboration with Dr. Brian Brooks, CC, an eye movement system is being developed for use with infants, below-average verbalization, and language barrier patients. The development is aimed for patients not able to understand commands to move their eye by causing stimuli to occur to the left, center and right of the patient. These events cause eye movement toward sound, light and mechanical movement. The unit has been installed, tested and used on patients in an ophthalmic testing laboratory. Sensory changes may be added to the system for improved patient eye movement response. ? ? In collaboration with Dr. Steven Stanhope and Shih-Chiao Tseng, CC, a time reaction reflex movement system is being developed to test a person's reaction to randomly """"""""on"""""""" laser-light stimuli directed on the floor. This permits evaluation of a person's mental and reflex action according to their reaction time to following the light stimulus. Signals generated in the computer system give the position of the light and indicate when a particular light stimulus is activated and deactivated. The floor contains force plates to detect foot placement and correlates this signal in the computer to indicate immediate foot placement position. Overall response of a person's reaction to the light is within one millisecond. The system has been completed and tested on the force plates and is ready for initial patient testing. Subsequently, a determination will be made for modification of the parameters and use after the initial testing. ? ? In collaboration with Dr. Richard Hendler, NHLBI, a modified version of a high speed optical multichannel spectrometer developed previously has been enhanced in terms of temporal and signal amplitude resolution. The kinetics of the bacteriorhodopsin photocycle that is initiated with a synchronized laser pulse (532nm, 7ns) is being studied using an optical system that follows the spectral changes associated with the transient intermediates of the photocycle. Complete spectra from approximately 400nm to 700nm are collected with less than 10 microseceond resolution that permits extraction, though single value decomposition analysis, of the role of the intermediates. To adapt to the next phase of this project that entails collecting infra-red data, a collaboration has been established with the National Institute of Standards and Technology. The optical system has been realigned to incorporate both the high-speed multichannel analyzer and the infra-red spectrometer. ? ? We are developing an automated or semi automated method for grading of corneal and conjunctival staining of dry eye in collaboration with Dr. Janine Smith, NEI. The method will use the Oxford Scheme for grading ocular staining in dry eye using various dyes and filters. We will utilize biomicroscopy, digital camera, optical filters, and instillation techniques for selected clinical dyes. In addition, the instrument will use image capture calibration techniques followed by image enhancement software. Image analysis software will give the grade percentage of the dry eye.
| Jin, A J; Nossal, R (2000) Rigidity of triskelion arms and clathrin nets. Biophys J 78:1183-94 |
