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. 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. 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. 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. 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) are 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.
| Jin, A J; Nossal, R (2000) Rigidity of triskelion arms and clathrin nets. Biophys J 78:1183-94 |
