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Biomedical subjects

R S Olson

Publications and source records attributed to R S Olson.

At least 19 recordsLinked to original sources
PubMed2001

Community re-entry after critical illness.

Community re-entry after a critical illness is a multifaceted ongoing process. Nurse case managers may have the opportunity for long-term follow-up. This is desirable because the individual with a disability must be considered as a developing and changing individual, physically, cognitively and spiritually. Coping and adapting to the many challenges is a continuous process as well. Although barriers persist in communities across the nation, much progress has been made in enabling persons with disabilities to live independently in the community. When value is placed on these individuals, they may live in the community as active and productive individuals who are seen for their abilities and not for their disabilities. Rehabilitation nurses have the opportunity to use many innovative approaches to access information, facilitate community resources and services, and ease transition for persons with disabilities who are returning to their communities. Nurses also have the opportunity to teach, empower, and advocate for individuals with disabilities so that they may achieve the highest level of independence possible. Successful community re-entry can only be achieved when the individual and his or her family are involved. Together with the rehabilitation team, they can return to the community as active and productive members of society or they may return simply because they belong to their community. Either way, they may enjoy quality of life as persons who have many abilities despite their disabilities.

Critical Illness↗
PubMed1985

Photoradiation therapy of cutaneous angiosarcomas in mice.

Cutaneous angiosarcoma is a relatively rare but devastating malignant vascular tumor. It has a high incidence of recurrence following conventional therapeutic modalities applied either singly or in combination. The increased vascularity of cutaneous angiosarcomas, facilitating selective uptake and retention of a photosensitizing agent, such as hematoporphyrin derivative (HPD), suggests that these tumors would respond well to photoradiation therapy. To study the feasibility of this treatment modality, transplantable hemangiosarcomas were implanted in B6C3F1 female mice. Within 2.5 to 3.5 hours after intraperitoneal administration of HPD, fluorescence was recorded in the tumor as compared with surrounding normal skin. When these photosensitized tumors were exposed to 70 J/cm2 of laser energy from an argon-pumped dye laser at 630 nm, the tumors showed marked necrosis within 24 hours. In another series, the tumors were initially photosensitized with HPD for 3 hours and then treated with laser energy ranging from 0 to 96 J/cm2. A dual labeling procedure demonstrated a dose-related decrease in DNA synthesis rate in tumors that were exposed to 0 to 30 J/cm2 at 24 hours after treatment. Furthermore, tumor tissue exposed to laser energy in excess of 30 J/cm2 showed no significant cellular DNA synthesis. These data, supported by histologic evidence of tissue destruction, suggest that photoradiation therapy has a great potential as a therapeutic modality for cutaneous angiosarcomas.

Animals↗
PubMed1984

Phototoxicity of brain tissue in hematoporphyrin derivative treated mice.

Photoradiation therapy conditions which have been used to treat subcutaneous and breast tumors are lethal when applied to the head of mice. Treatment of control mice with laser light at 631 nm over an energy density range of 0-90j/cm2 had no measurable effect but mice photosensitized with 5 mg HPD/kg 72 hrs prior to laser treatment showed a threshold for brain damage at 56j/cm2, above which the mice developed cerebral edema and died. Laser treatment caused the same rate and magnitude of temperature rise in both control and HPD-photosensitized mice. Moreover, studies using mice whose brain temperature was kept below 37 degrees C during laser treatment showed a greater phototoxicity than mice without temperature regulation. Therefore, temperature rise in cerebral tissue was not associated with phototoxicity in the brain. In contrast the oxygen consumption rate in a brain cell suspension from an HPD-treated mouse was only 54% of that from a control mouse following treatment with laser light. This observation, when taken with supporting data from other investigations, suggests that one mechanism for the phototoxic response in brain tissue is oxygen deprivation resulting from mitochondrial damage.

Animals↗
PubMed1982

Development of a protocol for photoradiation therapy of malignant brain tumors: part 1. Photosensitization of normal brain tissue with hematoporphyrin derivative.

The successful application of phototherapy to subcutaneous tumors has suggested that a similar procedure should be developed for treating gliomas. As a result, attempts are being made to determine a set of conditions that would optimize the destruction of tumor cells while minimizing injury to surrounding brain tissue. To initiate this task, we developed a novel assay method to assess the amount of phototoxicity induced in normal brain by light exposure of mice treated with hematoporphyrin derivative (HPD). The application of this procedure demonstrated that a sufficient amount of HPD was retained in brain tissue, even 72 hours after injection, to cause severe cerebral damage in light-treated mice.

Animals↗
PubMed1976

Measurement of the cell migration index with a HeNe laser.

Human diploid fibroblasts (WI38) were inoculated into Rose multipurpose culture chambers, using a high population density to develop confluency. After 24 hours, cells from a 1 mm swath were scraped from the center of the chamber. This cleared path was positioned to permit an unobstructed transmission of a 0.9 X 20 mm beam of light from a 1 mW HeNe laser. As cells migrated, at 37 degrees C, into the path of the laser beam the light scatter was recorded, using a photomultiplier tube. Because the amount of light scatter was proportional to the number of cells migrating into the beam, the system measured the migration index of the cells. Slight variations in the design of this device could facilitate data collection during surveys of toxic agents, fertility tests, and delayed hypersensitivity.

Cell Movement↗