烧伤家兔血清免疫抑制性研究

利用 TBSA20%,Ⅲ度烧伤家兔模型,在排除了麻醉干扰和尽量剔除了动物菌血症及可能的脓毒症影响的条件下,对烧伤血清的免疫抑制性进行了探讨。旨在观察家兔烧伤后血清是否存在免疫抑制性。结果表明:烧伤动物血清仍存在免疫抑制性,且于伤后第4天所获血清的抑制性最强。利用超滤膜分离伤后第4天血清.发现分子量低于1万及1～3万的烧伤血清超滤物免疫抑制性最强,3万以上的烧伤血清超滤物也具有较强的免疫抑制性。提示:烧伤血清免疫抑制物成分较为复杂,分子量范围较宽。尽管在动物烧伤后第4天的血清中未能发现明显的蛋白电泳异常带,但低分子量的烧伤血清物质中可能存在着主要的免疫抑制物。     

烧伤家兔血清免疫抑制性研究

利用ＴＢＳＡ２０％，Ⅲ度烧伤家兔模型，在排除了麻醉干扰和昼剔除了动物菌血症及可能的脓毒症影响的条件下，对烧伤血清的免疫抑制性进行了探讨。旨在观察家兔烧伤后血清是否存在免疫抑制性。     

肠饲谷氨酰胺对严重烧伤小型香猪肠道葡萄糖代谢的影响

采用小型香猪３０％ＴＢＳＡ烧伤模型，动态观察了烧伤后肠道补充谷氨酰胺对肠道葡萄糖代谢的影响，结果显示：伤后第１天，不补充谷氨酰胺组肠道葡萄糖的消耗量明显减少，而补充谷氨酰胺组则出现少量的净释放，为０．１１μｍｏｌ·ｍｉｎ－１·ｋｇ－１。伤后第４天，两组均出现净释放，补充谷氨酰胺的动物明显高于不补充谷氨酰胺的动物；伤后７、１０天，两组仍维持葡萄糖的净释放。提示严重烧伤后肠道补充谷氨酰胺能明显减少肠道对葡萄糖的利用，增加肠道葡萄糖的生成能力。     

汤伤后抗生素应用时机与感染关系的实验研究

用白色雄性家兔４５只，制成１５％Ⅲ度汤伤后绿脓杆菌（ＰＡ）感染模型，分为预防、治疗和对照组三组。伤后立即静脉注射头孢哌酮（ＣＰＺ）组（预防组），在伤后１周内创面结痂、干燥，免疫蓉光抗体染色见ＰＡ仅位于焦痂浅层；而第４８小时开始静脉注射ＣＰＺ组（治疗组），则在伤后第３、４天ＰＡ即侵入焦痂深层肌组织。血液细菌培养阳性率和动物病死率后者明显高于前者，且与对照组结果相同。这提示严重烧（烫）伤后必须在渗出早     

肠饲谷氨酰胺对严重烧伤小型香猪肠道葡萄糖代谢的影响

采用小型香猪３０％ＴＢＳＡ烧伤模型，动态观察了烧伤后肠道补充谷氨酰胺对肠道葡萄糖代谢的影响，结果显示：伤后第１天，不补充谷氨酰胺组肠道葡萄糖的消耗量明显减少，而补充谷氨酰胺组则出现少量的净释放，为０．１１μｍｏｌ．ｍｉｎ＾－１；ｋｇ＾－１。伤后经４天，两组均出现净释放，补充谷氨酰胺的动物明显高于不补充谷氨酰胺的动物；     

大鼠烫伤后肠道免疫屏障损伤的实验研究

为探索烧伤后肠道免疫屏障损伤的规律及其与肠道细菌移位的关系，我们对烫伤大鼠肠道免疫屏障的损伤进行了比较全面的动态观察，结果表明，伤后早期动物肠道内容物ＩｇＡ（免疫球蛋白Ａ）含量明显降低，肠固有层及上皮内ＣＤ３＋（Ｔ细胞总数）和ＣＤ４＋（辅助／诱导Ｔ细胞）Ｔ淋巴细胞明显减少，上皮内ＣＤ４＋与ＣＤ８＋（抑制／杀伤Ｔ细胞）Ｔ细胞数量的比值倒置；伤后肠道细菌ＩｇＡ包被率亦明显降低，且在整个实验过程中均明显低于伤前组；与上述改变相对应，肠道细菌移位率在伤后早期明显升高。提示，伤后肠道免疫屏障损伤是多方面的，而这一损伤对烧伤后肠道细菌移位和脓毒症的发生、发展可能起着重要作用。     

补锌对烫伤大鼠锌,生长激素及羟脯氨酸的影响

目的 探讨补锌对创面愈合的影响。方法 ＳＤ大鼠８０只，随机分成伤前对照组，正常饲料组（Ｎ组），创面补锌组（Ｗ组），口服补锌组（Ｈ组），后三组动物致烫伤，各组分别于伤后１，３，７天活杀８只大鼠，留取血清，烫伤皮肤，观察不同途径补锌对烫伤和血清锌、生长激素、皮肤锌、羟脯氨酸的影响。结果 Ｎ、Ｗ组血清、皮肤锌伤后第１天下降，而Ｈ组明显上升，分别为Ｎ组的２，４，２．０倍（Ｐ〈０．０１），Ｗ组伤后３，７天皮     

补锌对烫伤大鼠锌、生长激素及羟脯氨酸的影响

目的探讨补锌对创面愈合的影响。方法ＳＤ大鼠８０只，随机分成伤前对照组，正常饲料组（Ｎ组），创面补锌组（Ｗ组），口服补锌组（Ｈ组），后三组动物致烫伤。各组分别于伤后１，３，７天活杀８只大鼠，留取血清、烫伤皮肤，观察不同途径补锌对烫伤大鼠血清锌、生长激素、皮肤锌、羟脯氨酸的影响。结果Ｎ、Ｗ组血清、皮肤锌伤后第１天下降，而Ｈ组明显上升，分别为Ｎ组的２．４，２．０倍（Ｐ＜０．０１），Ｗ组伤后３，７天皮肤锌明显增加，分别为Ｎ组的１．３，１．５倍（Ｐ＜０．０１）。伤后各组生长激素均呈上升趋势，第３天达高峰，以Ｈ组上升最明显，分别为伤前和Ｎ组的２．５，１．８倍（Ｐ＜０．０１）。烫伤皮肤羟脯氨酸各组均呈下降趋势，Ｎ组最明显，伤后７天低于伤前１／２，而Ｗ组羟脯氨酸伤后７天回升，约为Ｎ组的１．５倍（Ｐ＜０．０１）。结论口服补锌能快速提高血清、皮肤锌含量和生长激素水平，创面补锌明显增加羟脯氨酸含量，两种补锌途径应同时并举，以促进创面愈合。     

治疗氢气球爆炸致深Ⅱ度烧伤23例

我院曾收治一批因氢气球爆炸引起头面部、手背烧伤患者８１例。其中深Ⅱ度烧伤２３例，男性６例，女性１７例，年龄 １４－３５岁，烧伤面积 １％－７％ＴＢＳＡ，合并轻度吸入性损伤１例，烧伤后１ｈ入院。 入院后立即清创，头面部采用暴露疗法，手背创面用磺胺嘧啶银冷霜包扎，定期换药至创面愈合。对３例４只手背较深创面在伤后第３天施行削痴后辐照猪皮覆盖，其中１例１只手背在术后第７天施行自体皮移植。吸人性损伤给予吸氧、雾化吸入、补液、抗生素、激素等对症治疗，７ｄ后症状消失。有２例发生耳后乳突部烧伤创面金黄色葡萄球菌感…     

大鼠烫伤后肠道屏障损伤的实验研究

为探索烧伤后肠道免疫屏障损伤的规律及肠道细菌移位的关系，我们对烫伤大鼠肠道免疫屏障的损伤进行了比较全面的动态观察，结果表明，伤后早期动物肠道内容物ＩｇＡ含量明显降低，肠固有层及上皮内ＣＤ３＋和ＣＤ４＋Ｔ淋巴细胞明显减少，上皮内ＣＤ４＋与ＣＤ８＋Ｔ细胞数量的比值倒置。     

Alterations in serum proteins following thermal injuries

Serum suppressive factors were proved to be present and considered to be one of the causes to bring about the suppression of body defence following thermal injury. As a preliminary step to ascertain the presence of immunosuppressive substances, we tried to find out any abnormality in the postburn serum proteins by comparison of burned and normal sera by means of immuno-precipitation-in-gel. Results of SDS-polyacrylamide gel electrophoresis, crossed immunoelectrophoresis, tandem crossed immunoelectrophoresis, and fused rocket immunoelectrophoresis showed that differences of precipitation bands or peaks existed between burned and normal sera, and abnormal constituents with relatively low molecular weight were present in the burned serum.     

Association of sepsis with an immunosuppressive polypeptide in the serum of burn patients

One hundred ninety serum samples from 51 burned patients were tested for immunosuppressive activity which might explain decreased host immune competence following thermal injury. The serum from a variable but significant percentage of these patients suppressed the response of normal human peripheral blood lymphocytes to phytohemagglutinin. The occurrence of immunosuppressive activity paralleled the severity of the injury. Ten of ten severely burned patients (severity index greater than 40), but only 20 of 30 patients with index 10--39.9, and three of 11 patients with Index 0--9.9 developed suppressive serum. Differences between these groups were significant (p less than .05). In all 19 patients who became septic, immunosuppressive serum activity immediately preceded or coincided with the septic episode. In contrast to the effect on lymphocytes, burn sera stimulated fibroblast proliferation. Immunosuppressive activity did not correlate with serum cortisol levels, blood transfusion, protein-calorie malnutrition, or anesthesia. Suppressive sera were not cytotoxic. A majority of the active serum factor(s) was contained in a low molecular weight (less than 10,000 daltons) polypeptide subfraction.     

Abnormalities of serum proteins following thermal injury

Suppressive factors were found to be present in serum and considered to be one of the causes of the suppression of body defences following thermal injury. The purpose of this study was to find out any abnormality of the postburn serum proteins by the comparison of burned and normal sera using immunoprecipitation in gel. The results of SDS-polyacrylamide gel electrophoresis, crossed immunoelectrophoresis, tandem crossed immunoelectrophoresis, and fused rocket immunoelectrophoresis showed that differing precipitation bands or peaks existed between burned and normal sera, and abnormal constituents with relatively low molecular weight were present in the burned serum.     

Isolation immunosuppressive serum components following thermal injury

There has been increasing recognition in recent literature that immunoregulatory factors can often be detected in the serum of patients with thermal and traumatic injuries. We, too, have shown that a significant number of patients with severe thermal injuries are profoundly immunosuppressed. This immunosuppression was mediated by substances which circulate in the serum which could be easily detected using in vitro lymphocyte assays. The suppressive material was not present in normal serum, and exerted its effects through the activity of a specific (suppressor) subpopulation of lymphocytes. In this study, we have analyzed serum samples obtained from burn patients by plasmapheresis for suppressive activity, then fractionated each using Sephadex G-200. Individual fractions were tested for suppressive activity in mixed lymphocyte cultures, and approximate molecular weights established for suppressive peaks by means of chromatography calibration standards. Evidence linking suppressive activity of the sera to the presence of endotoxin, prostaglandin E, interferon, and "cutaneous burn toxin' is discussed.     

The immunosuppressive activity of C1q degradation peptides

We have previously reported the existence and activity of a collagen-like, low molecular weight, suppressive peptide complex in patients with greater than 40% BSA burns. Since C1q participates in the inflammatory response and contains a collagen-like sequence, we have tested, in vitro, the putative generation and immunologic activity of C1q peptide fragments under physical conditions present in burned patients. Nanogram quantities of heat- and enzyme-generated fragments of C1q were shown to be suppressive in vitro to neutrophil chemotaxis, and the mixed lymphocyte response (MLR). The addition of lymphocytes pretreated with C1q fragments suppressed ongoing MLR, indicating the activation of suppressor cells by the peptides. Rabbit anti-C1q globulin was found to reduce the suppressive activity of the collagen-like suppressor which was isolated from human burn sera. Our results therefore suggest that C1q may be an early source of degradation peptides which have strong nonspecific immunosuppressive activity following thermal injuries.     

Definition of a burn injury-induced immunosuppressive serum component

We and others have previously observed that immunologic activity can often be restored to both lymphocytes and neutrophils by removing them from the burn environment, leading to the conclusion that burn serum contains substances capable of suppressing immunologic function. The present studies were initiated to better define the serum component(s) responsible for this immunosuppression. The majority of immunosuppressive activity vs. both neutrophil chemotaxis and mixed lymphocyte cultures contained in large-volume serum samples obtained from three patients with greater than 40% body surface area flame burns was found to reside in a less than 25,000 mw fraction of serum obtained by Amicon ultrafiltration. A single suppressive serum component was isolated by precipitation and resuspension, followed by ion-exchange chromatography using an SP Sephadex C-25 column. Purity of the samples was verified by SDS slab-gel electrophoresis, and immunosuppressive activity was confirmed vs. both lymphocytes and neutrophils. Analysis of this isolated burn-associated suppressor indicates: a) a molecular weight of between 1,000 and 5,000 daltons; b) a complex composition containing a protein component, a lipid component, and a carbohydrate component; c) a structure which is heat stable, pH stable and unaffected by treatment with trypsin, proteinase K, DNAse, and RNAse; and d) a noncytotoxic immunosuppressive mode of action. It appears that the suppressive activity is dependent upon a prostaglandin portion of this low molecular weight complex.     

In vitro effects of complement inactivation upon burn-associated cell-mediated immunosuppression

Serum of severely burned patients possesses in vitro capacity to suppress cell-mediated immunologic responses. Failure to establish immune competence is predictive of mortality, usually from sepsis. In this investigation, the hypothesis that complement fragments, known to be elevated in the acute phases of burn injury, contribute to this suppression is tested. Serum taken from patients with massive (greater than 60%) and major (less than or equal to 60%) burn injury was analyzed for the ability to suppress mitogen-induced lymphocyte blastogenesis before and after exposure of the burn serum to (complement inactivating) temperatures. All patients in this study had immune suppressive serum. Heat inactivation partially restored immune competence in the serum of all patients, though significantly more so in patients with major burns compared with those with massive burns. Complement appears to play a contributory role in the acute stages of burn-induced, cell-mediated immunosuppression, though its role in patients with massive burn injury is overshadowed by the presence of serologic suppressive factors not present (or present in lower concentration) in patients with major burns.     

Immune restoration with interleukin-2 in patients with squamous cell carcinoma of the head and neck

Patients with head and neck squamous cell carcinoma commonly have depressed cell-mediated immunity which is known to correlate with ultimate prognosis. Selective immune studies were conducted in 27 head and neck cancer patients to determine the potential of interleukin-2 as an immune restorative agent. Patients showed the expected depression of lymphocyte proliferation to phytohemagglutinin and had borderline depressed natural killer cell activity and relatively normal interleukin-2 production. Addition of interleukin-2 at 100 units/ml markedly enhanced natural killer cell activity to normal levels. Serum from head and neck patients was also immune-suppressive. Heat-inactivated serum depressed lymphocyte proliferation and natural killer cell activity of control leukocytes. Lymphocyte incubation with interleukin-2 significantly counteracted immune suppressive serum effects and restored depressed lymphocyte function to normal levels. The effective in vitro interleukin-2 dose is potentially achievable by infusion at approximate doses of 3 X 10(6) units/M2.     

The anemia of thermal injury: partial characterization of an erythroid inhibitory substance

Anemia is one of a large number of systemic changes occurring in severely burned patients and has a multifactorial etiology including hemorrhage, hemolysis, and depression of the rate of erythropoiesis. In previous studies, it was found that serum of burned humans and animals contained a substance(s) capable of interfering with red cell colony formation in vitro. Here are reported studies done in an attempt to characterize further the inhibitory activity. The molecular weight was more than 50,000 daltons by ultrafiltration. By gel filtration an inhibitory region was identified with an approximate molecular weight range of 140-290,000. Treatment of sera with proteolytic enzymes resulted in loss of activity suggesting that the inhibitory substance(s) was a protein. Ion exchange chromatography indicated that the inhibitor was an acidic protein. It is suggested that this material participates in the pathophysiology of the anemia of thermal injury by depressing red cell production.