Comparing the effect of high frequency oscillatory ventilation and conventional mandatory ventilation on the myocardial function of rabbit with inhalation injury / 中华烧伤杂志

<p><b>OBJECTIVE</b>To compare the effect of high frequency oscillatory ventilation (HFOV) and conventional mandatory ventilation (CMV) on the myocardial function of rabbits with inhalation injury.</p><p><b>METHODS</b>Steam inhalation injury model was reproduced in 16 New Zealand albino rabbits. They were randomly divided into CMV group (n = 8) and HFOV group (n = 8) by drawing lots, and they received ventilation in metered volume and HFOV treatment respectively. Heart blood was drawn from rabbits before they were sacrificed 4 hours after treatment to determine the plasma activity of lactate dehydrogenase 1 (LDH1) and creatine phosphorylated kinase (CPK-MB). Myocardial tissue from left ventricle was harvested and homogenized to determine the concentration of TNF-α and IL-8, the activity of caspase-1, and the activity of myosin-light-chain kinase (MLCK) and the ATPase of myosin light chain (MLC-ATPase) by enzyme-linked immunosorbent assay, spectrophotometry, and the nuclide liquid scintillation technique respectively. Part of the myocardial tissue sample was examined pathologically. Data were processed with analysis of variance.</p><p><b>RESULTS</b>(1) The activities of LDH1 and CPK-MB in plasma were obviously higher in CMV group than in HFOV group [(643 ± 108), (342 ± 48) U vs. (233 ± 92), (186 ± 36) U, with F value respectively 10.326 and 9.846, P values all below 0.01]. (2) The contents of TNF-α, IL-8 and the activity of caspase-1 in myocardial tissue homogenate were obviously higher in CMV group than in HFOV group [(181 ± 35), (89 ± 19) pg/g, and (0.56 ± 0.27) g/g protein vs. (94 ± 21), (43 ± 11) pg/g, and (0.24 ± 0.12) g/g protein, with F value respectively 8.239, 7.826, 5.716, P values all below 0.01]. (3) The activities of MLC-ATPase and MLCK were lower in CMV group than in HFOV group [(0.24 ± 0.12) µmol×mg(-1)×min(-1), (3.3 ± 1.1) mmol×mg(-1)×min(-1) vs. (0.48 ± 0.16) µmol×mg(-1)×min(-1), (7.7 ± 1.7) mmol×mg(-1)×min(-1), with F value respectively 4.125, 4.766, P values all below 0.01]. (4) No obvious necrosis, degeneration or inflammatory cell infiltration was observed in myocardial tissue of rabbits in 2 groups under light microscope; but the myocardial fiber was slightly swollen, and it was less marked in the HFOV group.</p><p><b>CONCLUSIONS</b>The influence of HFOV on myocardial myosin phosphorylation system of rabbits with inhalation injury is less than that of CMV.</p>

Effects of high frequency oscillatory ventilation and its combination with pulmonary surfactant treatment on inflammatory response in rabbit lung with inhalation injury / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of high frequency oscillatory ventilation (HFOV) and its combination with administration of pulmonary surfactant (PS) on inflammatory response of lung tissue in rabbits with inhalation injury.</p><p><b>METHODS</b>Severe steam inhalation injury models were reproduced in 24 New Zealand albino rabbits. They were divided into control group (n = 8), HFOV group (n = 8), and HFOV + PS group (n = 8) according to the random number table, and they received ventilation in metered volume, HFOV, and HFOV + PS treatment respectively. Lung tissue samples of rabbits were collected at 3.5 h after treatment for pathological inspection and pulmonary injury score, assay of the activity of myeloperoxidase (MPO) and cysteinyl aspartate-specific protease 1 (caspase-1), and the determination of the contents of TNF-alpha, IL-18, IL-10, IL-13 and their mRNA expression.</p><p><b>RESULTS</b>Pathological change in different degree of rabbit lung tissue in each group were observed, and they were most obvious in the control group, and least in the HFOV + PS group. The lung tissue injury scores of control group, HFOV group, and HFOV + PS group was 3.71 +/- 0.43, 2.87 +/- 0.26, and 2.08 +/- 0.28 respectively. The difference between either two of them were statistically significant (P < 0.01). The MPO content and caspase-1 activity of rabbits in HFOV and HFOV + PS groups were obviously lower than those in control group (P < 0.01), and MPO content and caspase-1 activity of rabbits in HFOV + PS group were obviously lower than those in HFOV group (P < 0.05). In HFOV group and HFOV + PS group, the contents of TNF-alpha, IL-18 and their mRNA expression in lung tissue homogenates were obviously lower than those in control group (P < 0.01); while the contents of IL-10, IL-13 and their mRNA expression were obviously higher than those in control group (P < 0.01). Changes in these contents and expression in HFOV + PS group were more obvious than those in HFOV group (P < 0.05).</p><p><b>CONCLUSIONS</b>HFOV can alleviate inflammatory response in rabbit lung tissue and pulmonary injury induced by inhalation injury, and the effect is more obvious when combined with PS.</p>

Measurements and significance of serum gastrin, plasma motilin and serum beta-endorphin in patients with severe burns / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the changes and significance of serum gastrin (GAS), beta-endorphin (beta-EP) and plasma motilin (MTL) in patients with severe burns.</p><p><b>METHODS</b>Blood samples were gotten according to different timepoints from 32 admitted burned patients, and then serum GAS, beta-EP and plasma MTL were determined by radio-immuno assay (RIA).</p><p><b>RESULTS</b>In patients with severe burns, serum GAS decreased significantly in early period. And at the timepoint of 8 h, it reached the lowest level. But during 9-24 h it elevated for a while, and then it reached a relatively stable level. MTL reached the highest level at the timepoint of 2 h after burning. Then at the shock stage, it was comparatively lower. And at the timepoint of 8 h after burning, it reached the lowest level, then raised persistently after reabsorption, but still lower than the normal level. At the early stage after burning, beta-EP raised, then reached the highest level at 8 h after burning. GAS and MTL decreased and beta-EP increased significantly with the increase of the burned area. However, when the burned area was over 70% of the total body surface area, there was no relationship between them.</p><p><b>CONCLUSION</b>Blood GAS, MTL and beta-EP have represented regular changes in patients with severe burns at the early stage after burning. And the pain-stimulus and shock are effective factors.</p>