The care of burned upper extremities

Two sets of factors will ultimately influence the outcome of the burned upper extremity. The first set of factors is the depth and severity of the burn. The second set is the group of complications of the burn injury attributable to edema, inflammation, immobility, and malposition. An awareness of the potential pitfalls that follow burn injury has resulted in improved primary care and a lessening of deformity. Progressive acute care with topical chemotherapy, early motion, thoughtful splinting, and timely burn wound closure are essential to reduce the need for secondary operations. Reconstructive efforts should be tailored to the individual needs of the patient. These procedures should be carefully planned with a view toward balancing aesthetic and functional considerations and minimizing the time required for rehabilitation.     

Production of elastase and other exoproducts by environmental isolates of Pseudomonas aeruginosa.

Pseudomonas aeruginosa isolates from environmental sources and bacteremic patients were compared for their levels of elastolytic activity. No significant differences were found. The incidence of production of toxin A, phospholipase C, alkaline protease, and elastase among the environmental strains was also as high as that previously reported for clinical isolates.     

Near-infrared spectrophotometric monitoring of oxygen distribution to intact brain and skeletal muscle tissues

During continuous near-infrared optical monitoring of brain cortex and hindlimb skeletal muscles, anesthetized, ventilated cats were exposed either to progressive alveolar hypoxia, or to acute hemorrhage followed in some cases by resuscitation. Hypoxia decreased cytochrome a,a3 oxidation state in muscle more than in brain, while tissue blood volume increased in brain and decreased in muscle. At a PaO2 of 25 torr, cytochrome a,a3 oxidation level in the brain was sufficient to support EEG activity, but the cytochrome a,a,3 oxidation state in resting, innervated hindlimb muscle was near zero. Hemorrhagic hypotension invariably decreased cytochrome a,a3 oxidation state and tissue blood volume more in muscle than in brain, and muscle cytochrome a,a3 was completely reduced at about a 25-ml/kg blood loss. These observations, supported by noninvasively measured changes in near-infrared absorption in the tissues during serial intravascular injections of indocyanine green dye, indicate that different cytochrome responses to hypoxia and oligemia in muscle vs. brain tissue are attributable to different regional circulatory adjustments.     

Structure of receptive fields of visually sensitive neurons of the cat hippocampus

Structure of receptive fields of visually sensitive neurons in areas CA1 and CA3 of the dorsal hippocampus was investigated in alert cats with the brain-stem pretrigeminal section. The receptive field (RF) structure of 76 hippocampal neurons was analyzed by methods of scanning the RF by moving stimuli and mapping all their surface by a stationary flashing spot. According to presented data the neurons were classified into three groups: neurons with homogeneous structure of the RF (54%), with nonhomogeneous (28%) and neurons more sensitive to stimulus motion (18%) than to a stationary flashing light. Experiments have shown that responses of hippocampal neurons are highly specific ones. Thus, 9% of neurons with the nonhomogeneous RF structure have shown specific responses to variation of the contrast and contours of moving stimuli. The presented results show that hippocampal visually driven neurons have well developed mechanism for processing visual sensory information and apparently this quality ensures participation of the limbic system in visually controlled behavior of the animal.