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Biomedical subjects

D H Koobs

Publications and source records attributed to D H Koobs.

7 recordsLinked to original sources

Use of the tunable dye laser to delay McFarlane skin flaps.

OBJECTIVE: To determine whether the argon tunable dye laser, used in a noncutting, hemocoagulative mode, improves skin flap survival as effectively as a surgical delay procedure. DESIGN: A physiologic, controlled trial was completed with three groups: acute control skin flaps, surgical delay skin flaps, and experimental laser delay skin flaps. The outcome variable was percentage of skin flap survival. SUBJECTS: Forty-four male Sprague-Dawley rats. INTERVENTIONS: McFarlane skin flaps were raised in all groups. The first group had no delay procedure, the second had the standard surgical delay, and the third group was lased at the periphery of the flap 2 weeks before raising the acute flap. RESULTS: The acute control group had survival of 85.7% +/- 1.5% (mean +/- SE) of skin flaps; surgical control group, 94.4% +/- 0.7%; laser delay group, 96.5% +/- 0.1%. The survival of the experimental group was better than the acute control group and was not different from the surgical delay group by the Scheffé multiple comparison test. CONCLUSIONS: This research may lead to a technique to reproduce the benefits of the delay phenomenon without the risks and cost of a surgical procedure.

Animals

Superiority of intralesional immunotherapy with Corynebacterium parvum and Allium sativum in control of murine transitional cell carcinoma.

Immunotherapy with bacillus Calmette-Guerin (BCG), Corynebacterium parvum (CP), keyhole limpet hemocyanin (KLH) and an extract of Allium sativum (AS) was studied in a transitional cell carcinoma (MBT-2) in mice. Comparison was made between intraperitoneal (IP) versus intralesional (IL) administration of these agents. C3H/He mice were transplanted subcutaneously in the hind limb with 5 X 10(4) tumor cells. After transplantation, mice were randomized into groups to receive either IP or IL treatments with BCG (2 X 10(6) CFU), CP (250 micrograms.), KLH (50 micrograms.) or AS (25 mg.). At weekly intervals the tumor volume was determined. To assess the local cellular events following these treatments, histopathological studies were performed 10 days after tumor transplant with tissues removed from the injected sites. IL route was much more effective than IP route in inhibiting tumor growth. CP and AS exhibited more significant therapeutic effect than BCG or KLH. No tumor developed in mice which received five IL treatments of CP or AS. The data indicate that CP or AS may serve as effective biological response modifiers in controlling transitional cell carcinoma. The study further emphasizes that route and frequency of administration are crucial variables determining efficacy of immunotherapy.

Animals

The origin of lipofuscin and possible consequences to the myocardium.

Examination by light and electron microscopy of human myocardium from necropsies and biopsy specimens has revealed evidence that mitochondria can be transformed into granules of lipofuscin. This pigment has been shown to arise from peroxidative destruction of polyunsaturated lipid membranes. A high rate of lipofuscin formation is indicated by the occurrence of brown atrophy of the heart in relatively young persons who died of conditions that were associated with inanition. Such lipofuscin formation suggests the importance of dietary antioxidants in preventing peroxidative damage to mitochondria. A by-product of lipid peroxidation, malonaldehyde, can react with nuclear DNA, blocking template activity. Nuclear damage of this kind could reduce the capacity for protein synthesis and limit mitochondrial and contractile protein replacement. Such a limitation would contribute to heart failure during stress. Peroxidative damage to the myocardium is cumulative and irreversible.

Adult