- Email: [email protected]
fish oil lipid mixture and metabolism
418
ceased. The inflammatory response was not due to microorganisms. Excision and closure of the bum wound at 3 h postbum attenuated the lipid peroxidation and compliance changes but did not decrease the neutrophil sequestration. Demling R. H., Lalonde C., Liu Y. P. et al. (1989) The lung inflammatory response to thermal injury. Relationship between physiologic and histologic changes. Surgery 106, (I), 52-59. Lymphocyte changes in different lymphoid compartments The number and phenotype of lymphocytes in seven different lymphoid compartments were measured at different times up to 60 days after extensive deep burns in rats. By day 2 there was lymphopenia in peripheral blood and depleted lymphocyte numbers in spleen and thymus. By day 6 the bone marrow and cervical lymph nodes were depleted to the levels found in spleen and thymus. By day 12 the splenic and cervical node lymphocyte numbers had returned to normal, whereas the bone marrow and thymus numbers were still markedly low. There was a 6.5fold increase in the number of lymphocytes draining the burn wound, pooled axillary, bra&al, inguinal and lumbar lymph nodes. By day 24 the thymus and bone marrow were virtually depleted of lymphocytes, the mesenteric lymph nodes showed depleted numbers whereas the nodes draining the burn wound showed continually increasing numbers of lymphocytes. This same pattern was maintained on day 48 but the number of lymphocytes in the mesenteric nodes had returned to normal. By day 60 the numbers of lymphocytes in all tissues had returned to normal except in the spleen and the nodes draining the burn wound where increased numbers persisted. Cell surface phenotyping showed important changes in all compartments except in the nodes draining the burn wound and in the blood during the first 6 days postburn and between 24 and 60 days postbum. Organ B. C., Antonacci A. C., Chiao J. et al. (1989) Changes in lymphocyte number and phenotype in seven lymphoid compartments after thermal injury. Ann. Swg. 2 10, (I), 78-89. Lymphocyte subpopulation changes Monodonal antibodies and dual colour tlow cytometry were used to study lymphocyte phenotypic expression in mice with deep bums covering 15 or 25 per cent TBSA. The lymphocytes were obtained from peripheral blood, lymph nodes and spleens. The monoclonal antibodies were specific for T cells, helper/inducer T cells, suppressor/cytotoxic T cells, B cells and activated T cells. The most consistent results were depressions in percentages of helper/inducer cells and suppressor/cytotoxic cells in spleens, depressions in subsets of these cell types and the appearance of increased percentages of non-B non-T lymphocytes. There were minimal changes in lymph node cells. The major alteration in peripheral blood lymphocytes was a marked depression in activated T cells. By 30 days after burning the mice showed marked splenic hypertrophy with more than a three-fold increase in spleen weight. Eschar excision and implantation studies showed that this hypertrophy and the splenocyte phenotype changes were related to the presence of burned tissue. Hansbrough J. F. and Gadd M. A. (1989) Temporal analysis of murine lymphocyte sub-populations by monoclonal antibodies and dual colour flow cytometry after bum and non-bum injury. Surgery 106, (I), 69-80. Thromboxane, haemodynamic stability and oedema formation Thromboxane A, production and effects were assessed in anaesthetized sheep and burned anaesthetized sheep treated with or without Dazmegrel. In the sheep with 40 per cent TBSA bums the
Burns (1989) Vol. 15/No 6
Dazmegrel (given before injury) prevented the increased thromboxane production but significantly increased the plasma content of prostacyclin. The Dazmegrel also induced a marked vasodilatation, a decreased systemic vascular resistance, a 30 per cent increase in fluid requirements and an increased lymph flow compared with bums alone. Oxygen consumption was better maintained following Dazmegrel administration suggesting that postbum vasoconstriction (and the associated hypovolaemia) impairs adequate oxygen delivery to tissues. Lalonde C. and Demling R. H. (1989) Inhibition of thromboxane synthase accentuates hemodynamic instability and burn edema in the anesthetized sheep model. Surgery 105, (5) 638-644. Wood smoke and pulmonary tissue permeability The effects of smoke inhalation were measured in dogs with respect to lung lymph flow (Qr) and plasma (Cp) and lymph (CL) protein concentrations. When the left atria1 pressure (Pb) remained normal there was little change in either Qi_ or the CLICp ratio. When the PL, was elevated QL increased significantly but there was no decrease in the CL/& ratio at high lymph flow rates. The ratio of protein concentrations in airway fluid and plasma was greater after smoke inhalation than after increases in left atria1 pressure but less than those induced by alloxan administration. Nieman G. F., Clark W. R., Goyette D. et al. (1989) Wood smoke inhalation increases pulmonary microvascular permeability. Surgery 105, (4), 481-487. Candida albicans and immunosuppression Studies in mice with 20 per cent TBSA deep burns showed that Candida albicam can spread from the GI tract. No spread was observed in non-burned mice whereas when both burned and sham burned mice had been immunosuppressed with cyclophosphamide GI tract dissemination was noted in 31 per cent of the burned animals and 23 per cent of the sham burned animals. By day 3 after the burn there was a significant difference in the dissemination between the burned and sham burned animals. The day 3 finding corresponded with the severest neutropenia induced by the cyclophosphamide. Ekenna 0. and Fader R. C. (1989) Effect of thermal injury and immunosuppression of the dissemination of Candiah aIbican.s from the mouse gastrointestinal tract. J. Bum Care Rehabil. 10, (2) 138-145. Efficacy of anti-pseudomonas treatments In view of the variation in the quantities of exotoxin A and proteases produced by pathogenic strains of Ps. aemginosa, optimal treatment of sepsis should include a reduction in the total microbial load in the host with human immunoglobulin G, a reduction in the total circulating protease load with alpha-l protease inhibitor and neutralization of the specific effects of exotoxin A with antitoxin treatment. In burned infected mice combined treatment using all these techniques was significantly better than individual treatments. Holder I. A. and Neely A. N. (1989) Combined host and specific anti Pseudomonas directed therapy for Pseudomonasaeruginosa infections in burned mice: experimental results and theoretic considerations. J. Bum Care Rehabil. 10, (2) 131-137. MCT/fish oil lipid mixture and metabolism Rats with bums covering 30 per cent TBSA were gastrostomy fed with equal amounts of carbohydrate and protein and with either safflower oil or a mixture of 60 per cent medium chain triglycerides (MCT) and 40 per cent fish oil as a lipid source. Measurements made on these two groups of animals showed that the rats fed with MCT/fish oil had significantly higher daily and cumulative nitrogen balances and rectus muscle protein fractional
419
Abstracts
synthetic rates. The same animals showed a 22 per cent decrease in per cent flux oxidized and a 7 per cent decrease in total energy expenditure compared with safflower oil-fed animals. A 15 per cent increase in liver protein fractional synthetic rate was accompanied by a significant elevation in total liver protein with MCT/fish oil administration. This latter lipid mixture reduced net protein catabolism following bums, in part by influencing tissue protein synthetic rates. The reduction in total energy expenditure is a unique feature of the MCT/fish oil mixture. Teo T. C., de Michele S. J., Selleck K. M. et al. (1989) Administration of structured lipid composed of MCT and fish oil reduces net protein catabolism in enterally fed burned rats. Ann. Surg. 210, (l), 100-107.
LABORATORY
STUDIES
‘Sealing’ alters capillary permeability Measurements were made of albumin leakage from standardized scalds inflicted on the rat jejunum with and without variously sized fractions of hydroxethyl starch (HES) admixed with the albumin to act as a sealing agent of the capillary pores. The HES fraction with molecular weights ranging between 100 000 and 300 000 daltons performed significantly better as a sealing agent than HES frac-
tions having molecular weights of 300 000 to 3.4 million daltons and with molecular weights of less than 50 000 daltons. Control groups received either Ringer’s lactate or 5 per cent albumin. AS the capillary sealing was shown to be independent of a colloid osmotic pressure effect it is believed to be related to the size and shape of the non-charged macromolecules. Zikria B. A ., King T. C., Stanford J. et al. (1989) A biophysical approach to capillary permeability. Surgery 105, (5). 625-631. Rapid estimate of biopsy bacterial content A rapid estimate of the extent of bacterial contamination in burn wound biopsy specimens can be obtained within 4 h of biopsy collection using a rapid manual histological technique (which allowed a classification of depth of bacterial involvement) and acridine orange fluorescent staining (for a semi-quantitative evaluation of the degree of infection). The results of these two techniques enabled rapid therapeutic decisions to be made while waiting for quantitative culture and sensitivity test results which arrive 24-48 h later. Mitchell V., Galizia J. P. and Foumier L. (1989) Precise diagnosis of infection in bum would biopsy specimens: combination of histologic technique, acridine orange staining and culture. J’.Bum cure Rehabil. 10,(3), 195-202.
Plastic Surgeon The Department Of Surgery at the University of Alberta is seeking a plastic surgeon who is willing to commit a significant portion of time to the medical and surgical care of patients in the new Firefighter’s Burn Treatment Unit in addition to surgical practice. Clinical or basic research experience is essential. Full university appointment at the assistant professor level available for a suitable candidate. Application deadline: 30 April, 1990. In accordance with Canadian immigration requirements priority will be given to Canadian citizens and permanent residents. Apply in writing with accompanying curriculum vitae to: Dr. C. 1. Lobay, Room 240,11044 82 Avenue, Edmonton, AB, Canada T6G OTZ. The University of Alberta is committed to the principle of equity in employment.
ceased. The inflammatory response was not due to microorganisms. Excision and closure of the bum wound at 3 h postbum attenuated the lipid peroxidation and compliance changes but did not decrease the neutrophil sequestration. Demling R. H., Lalonde C., Liu Y. P. et al. (1989) The lung inflammatory response to thermal injury. Relationship between physiologic and histologic changes. Surgery 106, (I), 52-59. Lymphocyte changes in different lymphoid compartments The number and phenotype of lymphocytes in seven different lymphoid compartments were measured at different times up to 60 days after extensive deep burns in rats. By day 2 there was lymphopenia in peripheral blood and depleted lymphocyte numbers in spleen and thymus. By day 6 the bone marrow and cervical lymph nodes were depleted to the levels found in spleen and thymus. By day 12 the splenic and cervical node lymphocyte numbers had returned to normal, whereas the bone marrow and thymus numbers were still markedly low. There was a 6.5fold increase in the number of lymphocytes draining the burn wound, pooled axillary, bra&al, inguinal and lumbar lymph nodes. By day 24 the thymus and bone marrow were virtually depleted of lymphocytes, the mesenteric lymph nodes showed depleted numbers whereas the nodes draining the burn wound showed continually increasing numbers of lymphocytes. This same pattern was maintained on day 48 but the number of lymphocytes in the mesenteric nodes had returned to normal. By day 60 the numbers of lymphocytes in all tissues had returned to normal except in the spleen and the nodes draining the burn wound where increased numbers persisted. Cell surface phenotyping showed important changes in all compartments except in the nodes draining the burn wound and in the blood during the first 6 days postburn and between 24 and 60 days postbum. Organ B. C., Antonacci A. C., Chiao J. et al. (1989) Changes in lymphocyte number and phenotype in seven lymphoid compartments after thermal injury. Ann. Swg. 2 10, (I), 78-89. Lymphocyte subpopulation changes Monodonal antibodies and dual colour tlow cytometry were used to study lymphocyte phenotypic expression in mice with deep bums covering 15 or 25 per cent TBSA. The lymphocytes were obtained from peripheral blood, lymph nodes and spleens. The monoclonal antibodies were specific for T cells, helper/inducer T cells, suppressor/cytotoxic T cells, B cells and activated T cells. The most consistent results were depressions in percentages of helper/inducer cells and suppressor/cytotoxic cells in spleens, depressions in subsets of these cell types and the appearance of increased percentages of non-B non-T lymphocytes. There were minimal changes in lymph node cells. The major alteration in peripheral blood lymphocytes was a marked depression in activated T cells. By 30 days after burning the mice showed marked splenic hypertrophy with more than a three-fold increase in spleen weight. Eschar excision and implantation studies showed that this hypertrophy and the splenocyte phenotype changes were related to the presence of burned tissue. Hansbrough J. F. and Gadd M. A. (1989) Temporal analysis of murine lymphocyte sub-populations by monoclonal antibodies and dual colour flow cytometry after bum and non-bum injury. Surgery 106, (I), 69-80. Thromboxane, haemodynamic stability and oedema formation Thromboxane A, production and effects were assessed in anaesthetized sheep and burned anaesthetized sheep treated with or without Dazmegrel. In the sheep with 40 per cent TBSA bums the
Burns (1989) Vol. 15/No 6
Dazmegrel (given before injury) prevented the increased thromboxane production but significantly increased the plasma content of prostacyclin. The Dazmegrel also induced a marked vasodilatation, a decreased systemic vascular resistance, a 30 per cent increase in fluid requirements and an increased lymph flow compared with bums alone. Oxygen consumption was better maintained following Dazmegrel administration suggesting that postbum vasoconstriction (and the associated hypovolaemia) impairs adequate oxygen delivery to tissues. Lalonde C. and Demling R. H. (1989) Inhibition of thromboxane synthase accentuates hemodynamic instability and burn edema in the anesthetized sheep model. Surgery 105, (5) 638-644. Wood smoke and pulmonary tissue permeability The effects of smoke inhalation were measured in dogs with respect to lung lymph flow (Qr) and plasma (Cp) and lymph (CL) protein concentrations. When the left atria1 pressure (Pb) remained normal there was little change in either Qi_ or the CLICp ratio. When the PL, was elevated QL increased significantly but there was no decrease in the CL/& ratio at high lymph flow rates. The ratio of protein concentrations in airway fluid and plasma was greater after smoke inhalation than after increases in left atria1 pressure but less than those induced by alloxan administration. Nieman G. F., Clark W. R., Goyette D. et al. (1989) Wood smoke inhalation increases pulmonary microvascular permeability. Surgery 105, (4), 481-487. Candida albicans and immunosuppression Studies in mice with 20 per cent TBSA deep burns showed that Candida albicam can spread from the GI tract. No spread was observed in non-burned mice whereas when both burned and sham burned mice had been immunosuppressed with cyclophosphamide GI tract dissemination was noted in 31 per cent of the burned animals and 23 per cent of the sham burned animals. By day 3 after the burn there was a significant difference in the dissemination between the burned and sham burned animals. The day 3 finding corresponded with the severest neutropenia induced by the cyclophosphamide. Ekenna 0. and Fader R. C. (1989) Effect of thermal injury and immunosuppression of the dissemination of Candiah aIbican.s from the mouse gastrointestinal tract. J. Bum Care Rehabil. 10, (2) 138-145. Efficacy of anti-pseudomonas treatments In view of the variation in the quantities of exotoxin A and proteases produced by pathogenic strains of Ps. aemginosa, optimal treatment of sepsis should include a reduction in the total microbial load in the host with human immunoglobulin G, a reduction in the total circulating protease load with alpha-l protease inhibitor and neutralization of the specific effects of exotoxin A with antitoxin treatment. In burned infected mice combined treatment using all these techniques was significantly better than individual treatments. Holder I. A. and Neely A. N. (1989) Combined host and specific anti Pseudomonas directed therapy for Pseudomonasaeruginosa infections in burned mice: experimental results and theoretic considerations. J. Bum Care Rehabil. 10, (2) 131-137. MCT/fish oil lipid mixture and metabolism Rats with bums covering 30 per cent TBSA were gastrostomy fed with equal amounts of carbohydrate and protein and with either safflower oil or a mixture of 60 per cent medium chain triglycerides (MCT) and 40 per cent fish oil as a lipid source. Measurements made on these two groups of animals showed that the rats fed with MCT/fish oil had significantly higher daily and cumulative nitrogen balances and rectus muscle protein fractional
419
Abstracts
synthetic rates. The same animals showed a 22 per cent decrease in per cent flux oxidized and a 7 per cent decrease in total energy expenditure compared with safflower oil-fed animals. A 15 per cent increase in liver protein fractional synthetic rate was accompanied by a significant elevation in total liver protein with MCT/fish oil administration. This latter lipid mixture reduced net protein catabolism following bums, in part by influencing tissue protein synthetic rates. The reduction in total energy expenditure is a unique feature of the MCT/fish oil mixture. Teo T. C., de Michele S. J., Selleck K. M. et al. (1989) Administration of structured lipid composed of MCT and fish oil reduces net protein catabolism in enterally fed burned rats. Ann. Surg. 210, (l), 100-107.
LABORATORY
STUDIES
‘Sealing’ alters capillary permeability Measurements were made of albumin leakage from standardized scalds inflicted on the rat jejunum with and without variously sized fractions of hydroxethyl starch (HES) admixed with the albumin to act as a sealing agent of the capillary pores. The HES fraction with molecular weights ranging between 100 000 and 300 000 daltons performed significantly better as a sealing agent than HES frac-
tions having molecular weights of 300 000 to 3.4 million daltons and with molecular weights of less than 50 000 daltons. Control groups received either Ringer’s lactate or 5 per cent albumin. AS the capillary sealing was shown to be independent of a colloid osmotic pressure effect it is believed to be related to the size and shape of the non-charged macromolecules. Zikria B. A ., King T. C., Stanford J. et al. (1989) A biophysical approach to capillary permeability. Surgery 105, (5). 625-631. Rapid estimate of biopsy bacterial content A rapid estimate of the extent of bacterial contamination in burn wound biopsy specimens can be obtained within 4 h of biopsy collection using a rapid manual histological technique (which allowed a classification of depth of bacterial involvement) and acridine orange fluorescent staining (for a semi-quantitative evaluation of the degree of infection). The results of these two techniques enabled rapid therapeutic decisions to be made while waiting for quantitative culture and sensitivity test results which arrive 24-48 h later. Mitchell V., Galizia J. P. and Foumier L. (1989) Precise diagnosis of infection in bum would biopsy specimens: combination of histologic technique, acridine orange staining and culture. J’.Bum cure Rehabil. 10,(3), 195-202.
Plastic Surgeon The Department Of Surgery at the University of Alberta is seeking a plastic surgeon who is willing to commit a significant portion of time to the medical and surgical care of patients in the new Firefighter’s Burn Treatment Unit in addition to surgical practice. Clinical or basic research experience is essential. Full university appointment at the assistant professor level available for a suitable candidate. Application deadline: 30 April, 1990. In accordance with Canadian immigration requirements priority will be given to Canadian citizens and permanent residents. Apply in writing with accompanying curriculum vitae to: Dr. C. 1. Lobay, Room 240,11044 82 Avenue, Edmonton, AB, Canada T6G OTZ. The University of Alberta is committed to the principle of equity in employment.