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Biomedical subjects

J R Coleman

Publications and source records attributed to J R Coleman.

136 records · Page 8Linked to original sources
PubMedDate not supplied

Electron microprobe analysis of particle deposited in lungs.

A technique that is based on the combined use of a conventional transmission electron microscope and a conventional electron probe x-ray microanalyzer permits an unambiguous identification of titanium dioxide (TiO2) particles in lung tissue and cells. Quite probably, many other inorganic particles can be identified with the use of this technique.

Aerosols↗
PubMedDate not supplied

Observations on tonotopic organization within the rat inferior colliculus using 2-deoxy-D[1-3H] glucose.

Tonotopic organization is a major feature of central auditory structures. The tritiated 2-deoxyglucose metabolic marking technique is demonstrated to be useful for visualizing isofrequency contours in the rat inferior colliculus. Following pure-tone stimulation, the central nucleus of the inferior colliculus shows discrete, prominent banding patterns and a well-organized tonotopic arrangement.

Acoustic Stimulation↗
PubMedDate not supplied

Effects of tectal grafts on sound detection deficits induced by inferior colliculus lesions in hooded rats.

The midbrain inferior colliculus (IC), a major integrating center for auditory processing, provides a model for structural, functional, and behavioral recovery. The present study examined the role of IC in spatial sound detection, and the effects of neural transplantation in sparing of behavioral performance. Hooded rats were presented noise bursts at ambient noise levels and 15 dB above this level randomly at one of eight locations in the horizontal plane, and rats were required to suppress licking upon detecting signal presentations. Following training, rats received bilateral IC lesions, bilateral lesions followed in 1 wk by bilateral tectal grafts (embryonic Day 18), or were sham operated. During repeated testing 15 to 30 days and 40 to 45 days following surgical procedures, rats with lesions showed impaired detection task performance when compared to grafted or sham animals. Detection ratios were statistically higher for grafted rats than for rats with lesions at repeated testing times. Performance of grafted animals was not statistically separable from the sham control group; however, grafted rats never achieved preoperative detection rates nor rates as high as sham rats. Postmortem implantation of diI crystals unilaterally into grafts demonstrated fiber labeling in the ipsilateral IC and lateral lemniscus, and retrograde labeling of neurons in the remaining host IC and dorsal nucleus of lateral lemniscus. Combined with results of previous studies, the results of this study suggest that sparing of detection performance for sounds occurring at random spatial locations may be attributable to partial integration of host-graft pathways.

Acoustic Stimulation↗
PubMedDate not supplied

Estrogen treatment and age effects on auditory brainstem responses in the post-breeding Long-Evans rat.

The auditory brainstem response (ABR) was recorded from 20-month-old Long Evans hooded female rats to determine if latency reductions occur from estrogen replacement. The ABR in these post-breeding age rats was also examined for reductions in response latencies as a function of adult age. Tone pip stimuli (8 and 40 kHz) were presented at 21, 51, or 81 s(-1). Aging control and ovariectomized animals showed slower response latencies for waves Ib-VI than young adults for 8 and 40 kHz stimulation at 21 s(-1). Increased stimulus rate resulted in longer latencies for all waves at 20 months. In contrast to hormone treatment effects in young adults, ABR latencies in post-breeding age estrogen-treated animals were not reduced, consistent with a general decrease in CNS responsiveness to estrogen steroids associated with age. The results also suggest that sensorineural modifications in the auditory system which prolong ABR latencies can occur early in the aging process of adult female subjects.

Aging↗
PubMedDate not supplied

Nursing challenges in managed care.

The emergence of managed care organizations offers many opportunities, challenges, and threats for nursing and nurses. The goal of these organizations (ensuring maximum value from resources used) is congruent with the basic philosophy of nursing, which focuses on the total needs of the patient, not just disease, and on maintaining the health of the individual to minimize the need for expensive health care services. Within the structure of managed care, however, there is also a need for strong professional advocacy to ensure that the needs of the members are adequately met as the organization strives to maintain costs. In meeting the needs of the organization and of the members, the nurse also plays an important role in managing the resources used in producing health care services.

Continuity of Patient Care↗