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Biomedical subjects

R G Calderhead

Publications and source records attributed to R G Calderhead.

6 recordsLinked to original sources
PubMed1999

Skin resurfacing improved with a new dual wavelength Er:YAG/CO2 laser system: a comparative study.

OBJECTIVE: The efficacy of a new dual wavelength Er:YAG and CO2 laser system was tested for skin resurfacing results on rabbits' ears and human facial skin. The dual wavelength laser delivers simultaneous pulses of low-energy CO2 and high-energy Er:YAG energies. Theoretically, combining the strengths of both laser types in one console should lead to improved clinical outcome. SUMMARY BACKGROUND DATA: The use of the laser for skin resurfacing and remodeling has dramatically increased over the past few years. The CO2 laser was the first laser to be used in this field, followed more recently by the E:YAG laser. Both lasers offer unique advantages and disadvantages. METHODS: The present study consists of an ear chamber experiment, conducted on eight rabbits, to examine vascular network formation, after laser resurfacing with a standard CO2 laser and the Er:YAG/CO2 laser. Resurfacing was also performed on human patients with the Er:YAG/CO2 laser and the results were compared with previously published results of CO2 laser resurfacing. RESULTS: Significant advantages, including an attenuation in the degree of edema and erythema and a shorter reepithelialization time compared to results with conventional CO2 systems, were observed with the Er:YAG/CO2 system. Improved tissue reorganization and good clinical results in nine of the ten patients (six ratings of "very good" and three "good") were observed. The clinical outcome of the remaining patient was rated as "fair." Minimal side effects were reported and observed in only three patients. The learning curve required to maximize the efficiency of the system is steep, however, requiring a thorough understanding of the different laser/tissue interactions associated with the two wavelengths. CONCLUSION: It is the authors' opinion that the dual wavelength Er:YAG/CO2 laser system offers a particularly efficient and flexible system to perform standard CO2 procedures for skin resurfacing with an improved clinical outcome, as well as other applications with the CO2 or Er:YAG energy delivered separately.

Aged↗
PubMed1991

Development of low reactive-level laser therapy and its present status.

A new subspecialty in the medical application of the laser has developed, especially over the last decade, depending on the therapeutic rather than the surgical applications of the laser. Laser therapy, or preferably, Low reactive-Level Laser Therapy (LLLT) is now being recognized as a valid medical tool. Two types of LLLT are presented, simultaneous and pure. In surgical laser applications, ranges of heat are generated in the target tissue, destroying or altering its architecture. This is referred to as high reactive-level laser treatment, or HLLT. In addition, nonphotothermally destructive reactions may also occur, such as photo-osmosis. These are also part of HLLT. Simultaneously, nondestructive thermal and nonthermal bioactivation occur at the periphery of the target tissue: this is "simultaneous LLLT" and occurs along with HLLT, explaining some of the advantages of laser surgery. Laser systems have been developed which deliver power and energy densities below the destructive level, only to activate the irradiated tissue. This is "pure LLLT." The history and background of LLLT are presented, the terminology discussed, and practical applications of LLLT are presented.

Female↗
PubMed1990

Morphological studies of bradykinin-treatments on the rat trigeminal sensory neuron.

Subcutaneous injections of bradykinin to the rat trigeminal region over 4 days produced a significant increase in the number of mitochondria in the small trigeminal ganglion cells and the central terminals of unmyelinated fibers in the spinal trigeminal nucleus. In the large trigeminal ganglion cells, no significant change in the number of mitochondria was observed. These results seem to demonstrate that bradykinin stimulates unmyelinated nerve and increases its energy consumption.

Animals↗