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Biomedical subjects

J Pine

Publications and source records attributed to J Pine.

At least 19 recordsLinked to original sources
PubMed1999

The neurochip: a new multielectrode device for stimulating and recording from cultured neurons.

The neurochip is a silicon micromachined device upon which cultured mammalian neurons can be continuously and individually monitored and stimulated. The neurochip is based upon a 4 x 4 array of metal electrodes, each of which has a caged well structure designed to hold a single mature cell body while permitting normal outgrowth of neural processes. We demonstrate that this device is capable of maintaining cell survival, and that the electrodes can both record and stimulate electrical activity in individual cells with no crosstalk between channels.

Algorithms↗
PubMed1999

Microstructures for studies of cultured neural networks.

A description is given of a functional silicon micromachined device that permits non-invasive, bidirectional, highly specific communication with cultured mammalian neurons. The heart of the system is a well structure that holds the cell in close proximity to a metal extracellular electrode while permitting normal outgrowth of axons and dendrites. An iterative approach is used to create a design that allows normal growth of the neurons while preventing their escape. An array of 16 such neurowells makes it possible to perform studies of biological neural network development and function with unprecedented detail.

Animals↗
PubMed1999

Social control of childhood stealing in a public school: a case study.

Although a common problem encountered by mental health specialists, there are few published descriptions of behavior therapy intervention for childhood stealing. The present case study addresses the behavioral treatment of stealing exhibited by a child in a pubic school setting. A functional assessment suggested that the behavior was maintained by the social attention it elicited from school personnel and parents. Using an hypothesis-driven model of treatment formulation, intervention consisted of eliminating multiple sources of attention in an extinction paradigm. Intervention was associated with a systematic reduction in stealing and results were maintained through a 12-month follow-up. Issues related to functionally determined treatment of behavior disorders are discussed.

Attention Deficit Disorder with Hyperactivity↗
PubMed1996

Neural transplant staining with DiI and vital imaging by 2-photon laser-scanning microscopy.

We are developing a multielectrode silicon "neuroprobe" for maintaining a long-term, specific, two-way electrical interface with nervous tissue. Our approach involves trapping a neuron (from an embryonic rat hippocampus) in a small well with a stimulation/recording electrode at its base. The well is covered with a grillwork through which the neuron's processes are allowed to grow, making synaptic contact with the host tissue, in our case a cultured slice from a rat hippocampus. Each neuroprobe can accommodate 15 neurons, one per well. As a first step in studying neurite outgrowth from the neuroprobe, it was necessary to develop new staining techniques so that neurites from the probe neurons can be distinguished from those belonging to the host, without interference from non-specific background staining. We virtually eliminated background staining through a number of innovations involving dye solubility, cell washing, and debris removal. We also reduced photobleaching and phototoxicity, and enhanced imaging depth by using a 2-photon laser-scanning microscope. We focused on using the popular membrane dye, DiI, however a number of other membrane dyes were shown to provide clear images of neural processes using pulsed illumination at 900 nm. These techniques will be useful to others wishing to follow over time the growth of neurons in culture of after transplantation in vivo, in a non-destructive way.

Animals↗
PubMed1995

Rapid changes in cellular immunity following a confrontational role-play stressor.

Recent laboratory studies have shown several immune system changes consistently associated with brief stress including increases in circulating natural killer (NK) cell numbers, increases in NK cell cytotoxicity (NKCC), increases in suppressor cytotoxic (CD8) T cell numbers, and decreases in the in vitro proliferative response to mitogen stimulation. In the present study, we use a confrontational role-play, which brings out responses varying from assertion to capitulation and examine the psychological, behavioral, physiological, and immune system responses to this task compared to a resting control task. Compared to the control condition, the brief confrontational role-play led to significant subjective and physiological arousal and increases in circulating NK (CD16, CD56) as well as large granular lymphocyte (CD57) cells and suppressor/cytotoxic T cells (CD8). There were also significant relationships between stress-related increases in the cardiovascular measures and the numbers of circulating NK cells. These findings support sympathetic nervous system activation as a primary mechanism for increases in NK cell numbers under challenge. These role-play results are generally consistent with those from other laboratory tasks such as mental arithmetic. However, in contrast to previously examined brief stressors, the role-play led to decreased NKCC adjusted for percentage of NK cells. This apparent differential change in NK cytotoxicity across different types of activating experimental tasks points to the importance of examining dimensions of the behavioral and emotional response to challenge or threat in addition to that of autonomic arousal.

Adult↗
PubMed1995

Standardization of terms and analytic methods for performance evaluation: achievable goal or impossible dream?

Communication about health care management is severely limited by the usage of words borrowed from the diverse professional groups that have contributed to the field. This article suggests development of a glossary of terms to eliminate much of the current confusion in discussions of outcomes, reduce redundancy, and form the basis for interdisciplinary understanding. As a starting point, some major concepts are discussed that warrant further refinement and definition. Also highlighted is the need for standards in describing and evaluating systems designed to measure outcomes of health care, with the goal of enabling consumers to compare these systems meaningfully.

Health Services Research↗
PubMed1994

Multi-neuronal signals from the retina: acquisition and analysis.

Throughout the central nervous system, information about the outside world is represented collectively by large groups of cells, often arranged in a series of 2-dimensional maps connected by tracts with many fibers. To understand how such a circuit encodes and processes information, one must simultaneously observe the signals carried by many of its cells. This article describes a new method for monitoring the simultaneous electrical activity of many neurons in a functioning piece of retina. Extracellular action potentials are recorded with a planar array of 61 microelectrodes, which provides a natural match to the flat mosaic of retinal ganglion cells. The voltage signals are processed in real time to extract the spike trains from up to 100 neurons. We also present a method of visual stimulation and data analysis that allows a rapid characterization of each neuron's visual response properties. A randomly flickering display is used to elicit spike trains from the ganglion cell population. Analysis of the correlations between each spike train and the flicker stimulus results in a simple description of each ganglion cell's functional properties. The combination of these tools will allow detailed study of how the population of optic nerve fibers encodes a visual scene.

Action Potentials↗
PubMed1994

Integrated health and education input in the development of educational resources about asthma for schools.

The development of educational packages on health-related topics has become common in school curricula. This paper describes an integrated health and education input in the development of an educational package about asthma for Year 8 high school students. Ownership and educational relevance of the package (ensuring its appropriateness for inclusion within the Personal Development/Health/Physical Education curriculum) was achieved by collaboration between teachers with an understanding of the principles of curriculum design and health professionals with content knowledge about asthma. The model used for the production of the package about asthma could be extended to other health topics.

Adolescent↗
PubMed1991

An apparatus for recording synaptic potentials from neuronal cultures using voltage-sensitive fluorescent dyes.

Voltage-sensitive dyes offer the promise of noninvasive multicell recording of electrical activity, and should therefore be useful for studying the synaptic interactions of small networks of cultured neurons. We have designed and built a system for recording from microcultures of 1-15 neurons from the rat superior cervical ganglion (SCG), using voltage-sensitive fluorescent dyes of the styryl class. The apparatus comprises a standard inverted epifluorescence microscope; a mercury arc lamp with an optical feedback regulator; a 256-pixel fiber-optic camera with individual photodiode detectors and very low-noise amplifiers; and a personal computer-based data acquisition system. Its dark noise and illumination fluctuations are low enough that at typical fluorescence levels for these cells, it is limited by shot noise (the inherent physical limit of detection). Recording from SCG neurons, the signal-to-noise ratio is high enough to see large subthreshold synaptic potentials without signal averaging. This apparatus should be useful for studying long-term synaptic plasticity in cultures of vertebrate neurons, and several of its features should apply to optical recording from other preparations.

Analog-Digital Conversion↗
PubMed1991

Voltage-sensitive dye recording of action potentials and synaptic potentials from sympathetic microcultures.

Given the appropriate multicell electrophysiological techniques, small networks of cultured neurons (microcultures) are well suited to long-term studies of synaptic plasticity. To this end, we have developed an apparatus for optical recording from cultured vertebrate neurons using voltage-sensitive fluorescent dyes (Chien, C.-B., and J. Pine. 1991. J. Neurosci. Methods. 38:93-105). We evaluate here the usefulness of this technique for recording action potentials and synaptic potentials in microcultures of neurons from the rat superior cervical ganglion (SCG). After extensive dye screening and optimization of conditions, we chose the styryl dye RH423, which gave fast linear fluorescence changes of approximately 1%/100 mV for typical recordings. The root mean square noise of the apparatus (limited by shot noise) was typically 0.03%, equivalent to 3 mV of membrane potential. Illumination for at least 100 flashes of 100 ms each caused no noticeable photodynamic damage. Our results show that voltage-sensitive dyes can be used to record from microcultures of vertebrate neurons with high sensitivity. Dye signals were detected from both cell bodies and neurites. Signals from presumptive dendrites showed hyperpolarizations and action potentials simultaneous with those in the cell body, while those from presumptive axons showed delayed propagating action potentials. Subthreshold synaptic potentials in the cell body were occasionally detectable optically; however, they were usually masked by signals from axons passing through the same pixel. This is due to the complex anatomy of SCG microcultures, which have many crisscrossing neurites that often pass over cell bodies. Given a simpler microculture system with fewer neurites, it should be possible to use dye recording to routinely measure subthreshold synaptic strengths.

Action Potentials↗
PubMed1989

Sealing cultured invertebrate neurons to embedded dish electrodes facilitates long-term stimulation and recording.

Recently it has become possible to form small networks of synaptically connected identified invertebrate neurons in culture. Using conventional saline-filled glass electrodes, it is difficult to simultaneously stimulate and record from more than 2 or 3 cultured neurons and to perform experiments lasting longer than several hours. We demonstrate that it is possible to overcome these limitations by using planar arrays of electrodes embedded in the bottom of a culture dish. The arrays employ conductive leads and insulation that are transparent, making the dishes compatible with voltage-sensitive dyes and inverted microscopy. Identified neurons from leech Hirudo medicinalis, slug Aplysia californica, and snail Helisoma trivolvis, have been grown on these arrays. Due to their large size (soma diameter 40-200 microns) these neurons form seals over the dish electrodes. Individual electrodes can then be used to stimulate and to record action potentials in the associated neuron. With sealing, action potentials have been recorded simultaneously from many neurons for up to two weeks, with signal-to-noise ratios as large as 500:1. We developed and tested a simple model that describes the voltage waveforms measured with array electrodes. Potentials measured from electrodes under cell bodies were primarily derivatives of the intracellular potential, while those measured from electrodes under axon stumps were primarily proportional to local inward Na+ currents. While it is relatively easy to record action potentials, it is difficult to record postsynaptic potentials because of their small size and slow rate of rise.

Action Potentials↗
PubMed1987

Quantitative imaging and microanalysis with a scanning soft x-ray microscope.

A scanning soft x-ray microscope has been developed that uses synchrotron radiation focused by a Fresnel zone plate to form a submicron beamspot on the specimen. Transmitted x-rays are detected and used to form a quantitative map of specimen absorptivity. Applications of the instrument to the imaging of whole wet cells and to the mapping of calcium in sections of bone are presented, with a resolution of 300 nm and an elemental sensitivity of 2 micrograms cm-2.

Animals↗
PubMed1986

Seat belt education program--a model for public health settings.

A cohort of 268 low-income mothers participating in the Women, Infants, and Children (WIC) Supplemental Food Program was enrolled in a seat belt education and motivation program. The goal of the study was to determine whether seat belt use could be increased by incorporating a brief educational intervention into an existing public health program. Seat belt use was monitored by an unobtrusive observer prior to and one month following the intervention. Seat belt use increased from a baseline of 4.9 to 12.6% one month following education (p less than .01).

Adult↗
PubMed1986

Child restraint law effects on motor vehicle accident fatalities and injuries: the New Mexico experience.

The New Mexico State Legislature passed a child restraint law applicable to children less than 5 years of age that became effective in June 1983. To evaluate the effectiveness of this law, we analyzed traffic accident data for New Mexico from January 1981 through September 1984. During this period, there were 20,972 children younger than 5 years of age in motor vehicle accidents. Restraint usage increased for this age group from a low of about 10% in 1981 to more than 40% in 1984 (P less than 10(-6)). Unrestrained children younger than 5 years of age were five times more likely to be killed and two times more likely to be injured than restrained children. Analysis of motor vehicle accident fatality and injury rates pre- and post-law revealed a 33% reduction in motor vehicle accident fatality rates and a 12.6% reduction in nonfatal injury rates for children younger than 5 years. We conclude that child restraint devices are effective in reducing motor vehicle accident fatalities and injuries in young children and the child restraint law has been effective in increasing child restraint usage and in reducing childhood death and injury in New Mexico.

Accidents, Traffic↗
PubMed1984

Assessing the activity of sarcoidosis: quantitative 67Ga-citrate imaging.

Three different methods of quantitating 67Ga-citrate lung images--a visual index, a computer-assisted index, and the total-lung-to-background ratio--were compared in 71 studies of patients with biopsy-proven sarcoidosis. Fifty consecutive cases were analyzed independently by two different observers using all three methods. In 45 patients, both gallium lung scans and bronchoalveolar lavage were performed within 2 weeks. In these studies, each index was correlated with the cell differential in the bronchoalveolar lavage fluid. The total-lung-to-background ratio proved to be the simplest to perform; correlated best with the original visual index (r = 0.81, p less than 0.00001) and the percentage of lymphocytes obtained in bronchoalveolar lavage fluid (r = 0.39, p less than 0.004); and showed the lowest interobserver variation. Sensitivity for detecting active disease was 84% compared with 64% and 58% for the visual and computer-assisted indices, respectively, with no sacrifice in specificity.

Cell Count↗
PubMed1980

Recording action potentials from cultured neurons with extracellular microcircuit electrodes.

Dissociated cell cultures of neurons from neonatal rat superior cervical ganglia have been grown in specially prepared dishes, the bottoms of which consist of glass coverslips on which thin-film microcircuits have been deposited. The microcircuit provides 32 microelectrodes per dish, each approximately 8 X 10 micrometer in area. Extracellular recordings of action potentials from individual neurons have been made, with good signal-to-noise ratios, for cells within 40 micrometer of the electrode centers. The microelectrodes are also suitable for passing the current required for extracellular stimulation and action potentials have been evoked by stimulating cell bodies and processes through the electrodes.

Animals↗