Effect of NASA light-emitting diode irradiation on wound healing.

OBJECTIVE: The purpose of this study was to assess the effects of hyperbaric oxygen (HBO) and near-infrared light therapy on wound healing. BACKGROUND DATA: Light-emitting diodes (LED), originally developed for NASA plant growth experiments in space show promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. In this paper, we review and present our new data of LED treatment on cells grown in culture, on ischemic and diabetic wounds in rat models, and on acute and chronic wounds in humans. MATERIALS AND METHODS: In vitro and in vivo (animal and human) studies utilized a variety of LED wavelength, power intensity, and energy density parameters to begin to identify conditions for each biological tissue that are optimal for biostimulation. RESULTS: LED produced in vitro increases of cell growth of 140-200% in mouse-derived fibroblasts, rat-derived osteoblasts, and rat-derived skeletal muscle cells, and increases in growth of 155-171% of normal human epithelial cells. Wound size decreased up to 36% in conjunction with HBO in ischemic rat models. LED produced improvement of greater than 40% in musculoskeletal training injuries in Navy SEAL team members, and decreased wound healing time in crew members aboard a U.S. Naval submarine. LED produced a 47% reduction in pain of children suffering from oral mucositis. CONCLUSION: We believe that the use of NASA LED for light therapy alone, and in conjunction with hyperbaric oxygen, will greatly enhance the natural wound healing process, and more quickly return the patient to a preinjury/illness level of activity. This work is supported and managed through the NASA Marshall Space Flight Center-SBIR Program.

A theoretical experimental method to determine the locus of desensitization.

Consider a ligand-gated channel with n agonist binding sites which can undergo desensitization. We present a theoretical experimental procedure for pinpointing the principal receptor state from which there is a transition to the desensitized state. The method is based on the observation that the dependence of the slope of the time constant of desensitization vs agonist concentration, at low concentrations, represents the state from which desensitization occurs. In those receptors where desensitization occurs from the open state (or the one immediately preceding it), the method also enables us to determine the number of binding sites.

Sequential approach for describing channel opening and desensitization.

A formula describing the time-course of activation and desensitization of nicotinic-like acetylcholine channels is developed. The method used to arrive at this simplified formula is based on a sequential approach. Based upon this approximated and simple formula, analytical expressions for various specific experimental aspects are derived. These expressions together with the corresponding experiments provide a method to evaluate in a sequential manner the various rate constants involved.

Efficacy and safety of cetirizine therapy in perennial allergic rhinitis.

A double-blind, placebo-controlled trial was undertaken to assess the safety and efficacy of once daily cetirizine in alleviating the symptoms of perennial allergic rhinitis. Subjects were adults with perennial allergic rhinitis, characterized by nasal congestion, postnasal discharge, sneezing, rhinorrhea, nasal itching, lacrimation, ocular itching, and itching of the roof of the mouth, and a total pretreatment symptom severity score of greater than or equal to 8. Patients were randomized to treatment with 10 mg cetirizine, 20 mg cetirizine, or placebo for 4 weeks. Efficacy was assessed in 215 patients and safety in 216. Cetirizine in once daily dosages of 10 or 20 mg proved to be effective in relieving the overall symptoms of perennial allergic rhinitis and particularly postnasal discharge and sneezing. The 10-mg dose afforded optimal symptomatic relief, and the 20-mg dose provided little or no additional benefit. Cetirizine was well tolerated, and the frequency of somnolence was not significantly greater in patients receiving this drug than in those given placebo.

On the transmission of sound generated by an electromagnetic device from the mastoid process to the petrous bone.

An electromagnetic device (EMD) for sound transmission from the mastoid process to the petrous part of the temporal bone was designed, built, and analyzed. A theoretical model was developed in order to predict the EMD acoustical performance and the distortion caused by skull bones. This model enabled the investigation of various technical improvements and calibration options. The EMD was miniaturized by using rare earth magnets in the construction of both external transmitter and internal receiver. In vitro implantation of the internal receiver into the mastoid process was carried out by simple mastoidectomy techniques. The input and output powers of the system, including the EMD and skull bones components, were measured and the power transfer function was calculated. The sound, which was generated by the EMD and transmitted through the dry as well as simulated cadaver skull, had high fidelity in spite of some vibratory distortion at the lower sonic frequencies. Results suggest that further development of hearing aids based on electromechanical sound transmission should take into account the specific acoustic response pattern of the skull bones.

Double-blind comparison of cetirizine and placebo in the treatment of seasonal rhinitis.

The efficacy and safety of cetirizine were evaluated in 419 patients with seasonal allergic rhinitis. Using a 4-way, double-blind randomization schedule, patients were given a 1-week course of once daily cetirizine (5, 10, or 20 mg) or placebo. Patient and physician efficacy ratings corresponded, indicating superiority of cetirizine to placebo (P less than .05) in reducing symptom severity scores for sneezing, rhinorrhea, ocular pruritus, nasal pruritus, watering of the eyes, and redness of the eyes. All cetirizine doses achieved higher efficacy ratings (72.7%, 79.2%, and 75.7%, respectively) than placebo (52.9%; P less than .05) by the physician's global assessment. Cetirizine was well tolerated, with sedation being the most common adverse experience, increasing in frequency at higher doses. A dose-response relationship was evident for selected symptoms, and the once daily 5-mg dose was found to be an effective minimum dose.

Terfenadine treatment of fall hay fever.

A double-blind, parallel, multicenter study was undertaken in 215 ragweed skin test positive-patients with fall hay fever. The patients were randomized and treated for seven days with either 60 mg terfenadine twice daily, morning and evening, and a placebo at noon, or with 4 mg chlorpheniramine or placebo three times daily. The severity of nasopharyngeal itching, sneezing, rhinorrhea, nasal congestion, and itchy, watery, red eyes was ranked daily by patients and evaluated before and after treatment by the physician investigators. The patients reported a significant reduction in symptoms within one day. The physician investigators detected moderate to complete relief of symptoms in a greater proportion of the patients treated with terfenadine (70%) and chlorpheniramine (73%) than in the placebo-treated patients (48%). The incidence of sedation with terfenadine treatment (2.5%) was not different from that with placebo (2.4%) and both were lower than with chlorpheniramine (7.6%). We conclude that terfenadine is as effective as chlorpheniramine for the treatment of fall hay fever and that, unlike chlorpheniramine, the incidence of sedation with terfenadine was not different from placebo.

Multicenter, double-blind, placebo-controlled trial of terfenadine in seasonal allergic rhinitis and conjunctivitis.

A multiclinic, double-blind, parallel and controlled study was conducted in the 1982 spring pollen season to evaluate and compare the effects of terfenadine, 60 mg bid with those of chlorpheniramine 4 mg tid and placebo for a treatment period of seven days in patients with seasonal allergic rhinitis and conjunctivitis. Of a total of 397 patients enrolled in the seven study centers, 345 patients were accepted for evaluation of efficacy and 393 patients for safety. The results show that based on the physicians' assessment of the overall efficacy, terfenadine was significantly superior to placebo and comparable to chlorpheniramine in the relief of allergic symptoms, with moderate to complete relief being observed in 60% (68/113) of the terfenadine-treated patients, in 60% (71/119) of the chlorpheniramine-treated patients, and in 30% (34/119) of the placebo-treated patients. The daily evaluation of severity of symptoms by the patients show that the effect of terfenadine and chlorpheniramine was evident on the first day after entry, reached a peak on the second day after entry, and persisted thereafter. Side effects were minor and infrequent in all treatment groups. There was no statistically significant difference in the incidence of sedation between the terfenadine (7.6%) and placebo (2.4%) groups whereas the incidence of sedation with chlorpheniramine (19%) was significantly higher. In conclusion, terfenadine is as effective as chlorpheniramine in the treatment of symptoms of seasonal allergic rhinitis and conjunctivitis with an incidence of sedation not significantly different from that with placebo and significantly less than with chlorpheniramine.