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Lymphocyte membrane changes
262
ANIMAL STUDIES Smoke-induced lung tissue changes The relationships between mild, moderate and severe smoke inhalation injuries and histopathological changes in the respiratory tree were studied in sheep. Light and electron microscopy -both transmission and scanning - revealed a primary dose-responsive injury of acute cell membrane damage in the trachea and bronchi leading to oedema, progressive necrotic tracheobronchitis with pseudomembrane formation and airways obstruction. These inflammatory and occlusive effects were followed by congestion, alveolar space oedema, atelectasis and bronchopneumonia. Morphological changes occurring in the alveolar epithelium following severe smoke injury included intracellular oedema in type 1 cells, changes in the membrane-bound vacuoles of type z cells and septal thickening caused by interstitial oedema. Capillary endothelial changes were not observed. Hubbard G. B., Langlinais P. C., Shimazu T. et al. (1991) The morphology of smoke inhalation injury in sheep. 1. Trutrma 31, (II), 1477-1486.
Matsuda T., Tanaka H., Williams S. et al. (1991)Reduced fluid volume requirements for resuscitation of third degree burns with 525-532. high dose vitamin C. 1. Btlm Care Rehabil. 12, (6), Causes of postburn skeletal muscle dysfunction The effect of bums of varying severity on the induction of skeletal muscle weakness postbum were measured in mice. Of particular interest were the secondary messenger cascades involving the function of the gastrocnemius muscle. With increasing burn size (20-50per cent TBSA) it was found that perturbations in the cyclic adenosine monophosphate and the inositol trisphosphate cascades induced increasing myoplasmic Ca’+ levels which lead to muscle dysfunction. Tomera J. F. (1991) The effects of bum trauma on adenosine 3,~ cyclic monophosphate, inositol trisophosphate and contraction in muscle. J Burn Care Rehabil. 12, (6), mouse gastrocnemius 485-497. Age dependence of effective bum resuscitation Studies in guinea-pigs showed that extensive scalds impaired cardiac function more in neonatal and senescent animals than in adult animals. Left ventricular pressures, + dP/df,,,, and - dPl df,,, were measured following resuscitation and with either 4 ml Ringer’s lactate/kg/l per cent burn or an initial bolus of hypertonic saline dextran (HSD) (4 ml/kg) plus 1 ml Ringer’s lactate/kg/ 1 per cent bum. Lactated Ringer’s solution failed to correct bum-induced cardiac contractile defects in any of the age groups. Postbum cardiac dysfunction persisted after HSD plus the smaller volume of Ringer’s lactate in the neonatal and senescent hearts but corrected the cardiac changes in adult animals, Horton J. W. and White D. J. (1991) Hypertonic saline dextran resuscitation fails to improve cardiac function in neonatal and senescent burned guinea pigs. 1. Trulnmu 31, (11), 1459-1466.
Benefits of OKG supplementation The effect of giving omithine alpha keto glutarate (OKG) on muscular and hepatic protein catabolism was measured in rats with bums covering 25 per cent of the body surface areas. Comparisons were made between (a) non-burned rats given food ad libitum (b) non-burned rats given a defined enteral feed supplemented with glycine (c) a group of burned rats given the enteral feed supplemented with glycine and (d) the experimental rats given OKG with the defined enteral feed. Animals in group (d) showed that OKG supplementation limited both muscle weight loss and muscle protein hypercatabolism and significantly improved the muscle glutamine pool. The bum injury itself induced muscle hypercatabolism without affecting hepatic tissue catabolism. Vaubourdolle M., Courdray-Lucas C., Jardel A. et al. (1991) Action of enterally administered omithine alpha glutarate on protein breakdown in skeletal muscle and liver of the burned rat. J Parent. Enfer. Nufr. 15, (3, 517-520.
LABORATORY STUDIES
Vitamin C and resuscitation fluid volumes Guinea-pigs with deep bums covering 70 per cent of the body surface area were resuscitated with 4 ml Ringer’s lactate (RL)/kg/l per cent bum or 1 ml RL/kg/l per cent bum without or with 170, 340 or 680 mg vitamin C. Compared with the 4 ml/kg/per cent bum therapy the best resuscitation effect in terms of cardiac outputs was obtained with the 1 ml RL/kg/l per cent bum plus 340 mg vitamin C. The therapy with the higher (680 mg) vitamin C therapy was no more beneficial than with half the dose. The regimen using 170 mg vitamin C was less effective. In terms of oedema formation 24 h after injury the vitamin C-treated groups showed significantly lower skin water contents than found in the groups receiving either 1 or 4 ml/kg/l per cent bum of Ringer’s lactate alone.
Lymphocyte membrane changes Lymphocyte membrane fluidity was measured in cells from both normal controls and from burned patients by the polarization of the fluorescence from membrane-linked diphenyl hexatriene. Normal lymphocyte membrane fluidity can be increased in vitro by short- and long-term exposure to cortisol and to ethanol. These observations lend credence to the finding that lymphocytes from burned patients have an abnormal membrane fluidity contemporary with measured increases in the plasma levels of cortisol. Lymphocytes with an altered membrane fluidity are less competent cells in many respects. Tolentino M. V., Sarasua M. M., Hill 0. A. et al. (1991) Peripheral lymphocyte membrane fluidity after thermal injury. 1. Bwn Cure Rehbil. 12, (6), 498-504.
ANIMAL STUDIES Smoke-induced lung tissue changes The relationships between mild, moderate and severe smoke inhalation injuries and histopathological changes in the respiratory tree were studied in sheep. Light and electron microscopy -both transmission and scanning - revealed a primary dose-responsive injury of acute cell membrane damage in the trachea and bronchi leading to oedema, progressive necrotic tracheobronchitis with pseudomembrane formation and airways obstruction. These inflammatory and occlusive effects were followed by congestion, alveolar space oedema, atelectasis and bronchopneumonia. Morphological changes occurring in the alveolar epithelium following severe smoke injury included intracellular oedema in type 1 cells, changes in the membrane-bound vacuoles of type z cells and septal thickening caused by interstitial oedema. Capillary endothelial changes were not observed. Hubbard G. B., Langlinais P. C., Shimazu T. et al. (1991) The morphology of smoke inhalation injury in sheep. 1. Trutrma 31, (II), 1477-1486.
Matsuda T., Tanaka H., Williams S. et al. (1991)Reduced fluid volume requirements for resuscitation of third degree burns with 525-532. high dose vitamin C. 1. Btlm Care Rehabil. 12, (6), Causes of postburn skeletal muscle dysfunction The effect of bums of varying severity on the induction of skeletal muscle weakness postbum were measured in mice. Of particular interest were the secondary messenger cascades involving the function of the gastrocnemius muscle. With increasing burn size (20-50per cent TBSA) it was found that perturbations in the cyclic adenosine monophosphate and the inositol trisphosphate cascades induced increasing myoplasmic Ca’+ levels which lead to muscle dysfunction. Tomera J. F. (1991) The effects of bum trauma on adenosine 3,~ cyclic monophosphate, inositol trisophosphate and contraction in muscle. J Burn Care Rehabil. 12, (6), mouse gastrocnemius 485-497. Age dependence of effective bum resuscitation Studies in guinea-pigs showed that extensive scalds impaired cardiac function more in neonatal and senescent animals than in adult animals. Left ventricular pressures, + dP/df,,,, and - dPl df,,, were measured following resuscitation and with either 4 ml Ringer’s lactate/kg/l per cent burn or an initial bolus of hypertonic saline dextran (HSD) (4 ml/kg) plus 1 ml Ringer’s lactate/kg/ 1 per cent bum. Lactated Ringer’s solution failed to correct bum-induced cardiac contractile defects in any of the age groups. Postbum cardiac dysfunction persisted after HSD plus the smaller volume of Ringer’s lactate in the neonatal and senescent hearts but corrected the cardiac changes in adult animals, Horton J. W. and White D. J. (1991) Hypertonic saline dextran resuscitation fails to improve cardiac function in neonatal and senescent burned guinea pigs. 1. Trulnmu 31, (11), 1459-1466.
Benefits of OKG supplementation The effect of giving omithine alpha keto glutarate (OKG) on muscular and hepatic protein catabolism was measured in rats with bums covering 25 per cent of the body surface areas. Comparisons were made between (a) non-burned rats given food ad libitum (b) non-burned rats given a defined enteral feed supplemented with glycine (c) a group of burned rats given the enteral feed supplemented with glycine and (d) the experimental rats given OKG with the defined enteral feed. Animals in group (d) showed that OKG supplementation limited both muscle weight loss and muscle protein hypercatabolism and significantly improved the muscle glutamine pool. The bum injury itself induced muscle hypercatabolism without affecting hepatic tissue catabolism. Vaubourdolle M., Courdray-Lucas C., Jardel A. et al. (1991) Action of enterally administered omithine alpha glutarate on protein breakdown in skeletal muscle and liver of the burned rat. J Parent. Enfer. Nufr. 15, (3, 517-520.
LABORATORY STUDIES
Vitamin C and resuscitation fluid volumes Guinea-pigs with deep bums covering 70 per cent of the body surface area were resuscitated with 4 ml Ringer’s lactate (RL)/kg/l per cent bum or 1 ml RL/kg/l per cent bum without or with 170, 340 or 680 mg vitamin C. Compared with the 4 ml/kg/per cent bum therapy the best resuscitation effect in terms of cardiac outputs was obtained with the 1 ml RL/kg/l per cent bum plus 340 mg vitamin C. The therapy with the higher (680 mg) vitamin C therapy was no more beneficial than with half the dose. The regimen using 170 mg vitamin C was less effective. In terms of oedema formation 24 h after injury the vitamin C-treated groups showed significantly lower skin water contents than found in the groups receiving either 1 or 4 ml/kg/l per cent bum of Ringer’s lactate alone.
Lymphocyte membrane changes Lymphocyte membrane fluidity was measured in cells from both normal controls and from burned patients by the polarization of the fluorescence from membrane-linked diphenyl hexatriene. Normal lymphocyte membrane fluidity can be increased in vitro by short- and long-term exposure to cortisol and to ethanol. These observations lend credence to the finding that lymphocytes from burned patients have an abnormal membrane fluidity contemporary with measured increases in the plasma levels of cortisol. Lymphocytes with an altered membrane fluidity are less competent cells in many respects. Tolentino M. V., Sarasua M. M., Hill 0. A. et al. (1991) Peripheral lymphocyte membrane fluidity after thermal injury. 1. Bwn Cure Rehbil. 12, (6), 498-504.