传染性单核细胞增多症患儿NLR、CD4+/CD8+比值、ADA与EBV-DNA载量的相关性分析及对肝损害的影响

摘要 目的：探讨传染性单核细胞增多症（IM）患儿外周血中性粒细胞/淋巴细胞比值（NLR）、CD4⁺/CD8⁺比值、腺苷脱氨酶（ADA）与EB病毒（EBV）-脱氧核糖核酸（DNA）载量的相关性,分析其对IM患儿肝损害的影响。方法：选择2019年1月至2022年4月我院儿科收治的102例IM患儿（IM组）,另选择同期我科收治的95例EB病毒检测阴性的发热患儿（非IM组）和体检健康的73例健康儿童（对照组）。根据是否发生肝损害将IM患儿分为肝损害组（61例）和非肝损害组（41例）。比较外周血NLR、CD4⁺/CD8⁺比值、ADA与EBV-DNA载量,Pearson法分析NLR、CD4⁺/CD8⁺比值、ADA与EBV-DNA载量的相关性。多因素Logistic回归分析IM患儿发生肝损害的影响因素。结果：IM组ADA高于非IM组和对照组（P＜0.05）,且非IM组高于对照组（P＜0.05）,NLR、CD4⁺/CD8⁺比值低于非IM组和对照组（P＜0.05）,且非IM组低于对照组（P＜0.05）,IM组EBV-DNA载量高于非IM组（P＜0.05）。IM患儿ADA与EBV-DNA载量呈正相关（r=0.493,P＜0.05）,NLR、CD4⁺/CD8⁺比值与EBV-DNA载量呈负相关（r=-0.419、-472,P＜0.05）。肝损害组ADA、EBV-DNA载量高于非肝损害组（P＜0.05）,NLR、CD4⁺/CD8+⁺比值低于非肝损害组（P＜0.05）。肝脏肿大、高EBV-DNA载量、高ADA是IM患儿肝损害的危险因素（P＜0.05）,高NLR、高CD4⁺/ CD8⁺比值是保护因素（P＜0.05）。结论：IM患儿ADA增高,NLR、CD4⁺/CD8⁺比值降低,与EBV-DNA载量增加以及肝损害有关。     

2型糖尿病并发肺结核患者PCT、HMGB1、CD4+/CD8+比值与继发肺部感染的关系

摘要 目的：探讨2型糖尿病并发肺结核患者降钙素原（PCT）、高迁移率族蛋白1（HMGB1）、CD4⁺/CD8⁺比值与继发肺部感染的关系。方法：选择2019年1月至2022年6月四川大学华西医院呼吸与危重症医学科收治的97例2型糖尿病并发肺结核患者,根据入院治疗时是否继发肺部感染分为肺部感染组（53例）及非肺部感染组（44例）。检测两组血清PCT、HMGB1水平以及外周血CD4⁺/CD8⁺比值。单因素和多因素Logistic回归分析2型糖尿病并发肺结核患者继发肺部感染的因素。受试者工作特征（ROC）曲线分析PCT、HMGB1和CD4⁺/CD8⁺比值预测2型糖尿病并发肺结核患者继发肺部感染的价值。结果：肺部感染组血清PCT、HMGB1水平高于非肺部感染组（P＜0.05）,外周血CD4⁺/CD8⁺比值低于非肺部感染组（P＜0.05）。糖化血红蛋白及血清PCT、HMGB1水平升高是2型糖尿病并发肺结核患者继发肺部感染的危险因素（P＜0.05）,高CD4⁺/CD8⁺比值是保护因素（P＜0.05）。PCT、HMGB1、CD4⁺/CD8⁺比值预测2型糖尿病并发肺结核患者继发肺部感染的曲线下面积为0.719、0.761、0.738,联合PCT、HMGB1和CD4⁺/CD8⁺比值预测的曲线下面积为0.878,高于各指标单独预测。结论：2型糖尿病并发肺结核患者血清PCT、HMGB1水平增高,外周血CD4⁺/CD8⁺比值降低,均与继发肺部感染有关,PCT、HMGB1联合CD4⁺/CD8⁺比值可辅助预测2型糖尿病并发肺结核患者继发肺部感染的风险。     

脾氨肽辅助抗结核药物治疗肺结核的临床疗效观察

摘要 目的：观察脾氨肽辅助抗结核药物治疗肺结核的临床疗效。方法：随机数值表法将2016年6月～2021年6月本院收治的120例肺结核患者分为观察组、对照组。对照组予常规抗结核药物治疗,观察组予脾氨肽辅助抗结核药物治疗。评价两组肺部病灶变化情况、肺部空洞变化情况;检测两组治疗2、4、6个月时痰培养转阴率;检测两组治疗前后外周血T淋巴细胞亚群CD3⁺、CD4⁺及CD4⁺/CD8⁺比值。结果：观察组肺部病灶变化、肺部空洞变化疗效的总有效率分别为95.00%、93.33%,明显高于对照组的83.33%、80.00%（P＜0.05）。两组在治疗6个月时的痰培养转阴率无显著差异（P＞0.05）,但观察组在治疗2、4个月时的痰培养转阴率均显著高于对照组（P＜0.05）。两组治疗前及对照组治疗前后的CD3⁺、CD4⁺及CD4⁺/CD8⁺比值比较无明显差异（P＞0.05）,但观察组治疗后的CD3⁺、CD4⁺及CD4⁺/CD8⁺比值均显著高于本组治疗前及对照组治疗后（P＜0.05）。结论：脾氨肽辅助抗结核药物治疗肺结核有助于提升临床疗效,可能与提升患者的免疫功能水平有关,值得临床进一步研究。     

外周血Treg细胞、T淋巴细胞及其亚群与早期宫颈癌的关系及对淋巴结转移的预测价值研究

摘要 目的：分析外周血Treg细胞、T淋巴细胞及其亚群与早期宫颈癌的关系及对淋巴结转移的预测价值。方法：选择我院自2017年1月至2020年12月接诊的60例接受子宫颈癌根治术及盆腔淋巴清扫术的早期宫颈癌患者作为观察组,另选同期的60例健康体检者作为对照组。比较两组外周血Treg细胞、T淋巴细胞及其亚群水平,使用受试者工作特征曲线（ROC）下面积（AUC）评价外周血Treg细胞、T淋巴细胞及其亚群对淋巴结转移的预测效能。结果：观察组外周血Treg细胞、CD8⁺T细胞水平高于对照组,CD3⁺T细胞、CD4⁺T细胞、CD4⁺/CD8⁺比值均低于对照组（P＜0.05）;观察组术后外周血Treg细胞、CD8⁺T细胞水平较术前降低,CD3⁺T细胞、CD4⁺T细胞、CD4⁺/CD8⁺比值均较术前升高（P＜0.05）;在60例早期宫颈癌患者中,发生淋巴结转移12例;淋巴结转移组术前外周血Treg细胞水平、CD8⁺T细胞高于非淋巴结转移组,CD3⁺T细胞、CD4⁺T细胞、CD4⁺/CD8⁺比值均低于非淋巴结转移组（P＜0.05）;经多因素Logistic回归分析,外周血Treg细胞、CD3⁺T细胞、CD4⁺/CD8⁺比值均是早期宫颈癌患者发生淋巴结转移的独立预测因素（P＜0.05）;经ROC曲线分析,外周血Treg细胞、CD3⁺T细胞联合CD4⁺/CD8⁺比值预测早期宫颈癌患者发生淋巴结转移的AUC为0.910。结论：外周血Treg细胞、T淋巴细胞及其亚群水平与早期宫颈癌的病情演变有关,其中外周血Treg细胞、CD3⁺T细胞联合CD4⁺/CD8⁺比值预测淋巴结转移的效能较好,值得进一步研究应用。     

腹腔镜与开腹胃楔形切除术对GIST患者营养状况、T细胞亚群和预后的影响

摘要 目的：探讨腹腔镜与开腹胃楔形切除术对胃间质瘤（GIST）患者营养状况、T细胞亚群和预后的影响。方法：回顾性分析2013年1月~2014年2月期间我院收治的GIST患者97例的临床资料,根据手术方式的不同将患者分为对照组（n=47,开腹胃楔形切除术）和研究组（n=50,腹腔镜胃楔形切除术）,对比两组患者手术相关指标、营养状况、T细胞亚群、预后情况。结果：研究组住院时间、肛门排气时间、切口长度、手术时间短于对照组,术中出血量少于对照组（P<0.05）。两组患者术后7 d前白蛋白、转铁蛋白、白蛋白均降低,但研究组高于对照组（P<0.05）。两组术后7 d的 CD4⁺/CD8⁺、CD3⁺、CD4⁺较术前下降,CD8+较术前升高（P<0.05）;研究组术后7 d 的CD4⁺/CD8⁺、CD3⁺、CD4⁺高于对照组,CD8⁺则低于对照组（P<0.05）。研究组并发症总发生率低于对照组（P<0.05）;两组术后复发率、5年生存率比较无统计学差异（P>0.05）。结论：与开腹胃楔形切除术相比,GIST患者采用腹腔镜胃楔形切除术治疗的远期预后效果相当,可有效改善围术期相关指标,对患者营养状况、T细胞亚群的影响较轻,且可减少术后并发症的发生率。     

老年2型糖尿病患者人巨细胞病毒感染与脂糖代谢、胰岛素抵抗及免疫失衡的关系研究

摘要 目的：探讨老年2型糖尿病（T2DM）患者人巨细胞病毒（HCMV）感染与脂糖代谢、胰岛素抵抗及免疫失衡的关系。方法：选取2021年2月~2022年3月长沙市第三医院收治的老年T2DM患者100例为研究组,选取同期来体检健康的志愿者60例作为对照组。根据HCMV-脱氧核糖核酸（DNA）检测结果将研究组分为阳性组41例和阴性组59例。检测并比较对照组、研究组HCMV-DNA载量、T淋巴细胞亚群（CD4⁺、CD8⁺、CD4⁺/CD8⁺）、脂糖代谢[高密度脂蛋白胆固醇（HDL-C）、糖化血红蛋白（HbA1c）、总胆固醇（TC）、空腹血糖（FBG）、三酰甘油（TG）、低密度脂蛋白胆固醇（LDL-C）]、胰岛素抵抗[空腹胰岛素（FINS）、胰岛素抵抗指数（HOMA-IR）]。采用Pearson相关性分析老年T2DM患者HCMV感染与脂糖代谢、胰岛素抵抗及免疫失衡的关系。结果：研究组的HCMV-DNA阳性率、HCMV-DNA载量高于对照组,阴性率低于对照组（P<0.05）。阳性组、阴性组的CD4⁺、CD4⁺/CD8⁺低于对照组,且阳性组低于阴性组（P<0.05）。阳性组、阴性组的CD8⁺高于对照组,且阳性组高于阴性组（P<0.05）。阳性组、阴性组的HbA1c、FBG、TC、TG、LDL-C高于对照组,且阳性组高于阴性组（P<0.05）。阳性组、阴性组的HDL-C低于对照组,且阳性组低于阴性组（P<0.05）。阳性组、阴性组的HOMA-IR、FINS高于对照组,且阳性组高于阴性组（P<0.05）。Pearson相关性分析结果显示,HCMV-DNA载量与CD4⁺、CD4⁺/CD8⁺、HDL-C呈负相关（P<0.05）,而与CD8⁺、HbA1c、FBG、TC、TG、LDL-C、FINS、HOMA-IR呈正相关（P<0.05）。结论：HCMV病毒感染可导致老年T2DM患者脂糖代谢紊乱,促进胰岛素抵抗,加重免疫失衡,加速疾病进展。     

贮存式自体成分输血对胃肠肿瘤根治术患者T淋巴细胞亚群、血液流变学和预后的影响

摘要 目的：研究贮存式自体成分输血对胃肠肿瘤根治术患者T淋巴细胞亚群、血液流变学以及预后的影响。方法：选取2016年12月~2017年12月我院收治的95例行胃肠肿瘤根治术的胃肠肿瘤早期患者作为研究对象。按随机数表法分为A组（n=47,贮存式自体成分输血）和B组(n=48,异体成分输血)。比较两组患者血常规指标[红细胞计数(RBC)、血红蛋白（Hb）、血细胞比容（Hct）]、免疫功能指标（CD3⁺、CD4⁺、CD8⁺、CD4⁺/CD8⁺）、血液流变学指标[红细胞沉降率、平均血液黏度、红细胞刚性指数及红细胞变形指数]的变化。随访患者2年,采用Kaplan-Meier曲线分析两组预后情况。结果：术前至术后7 d 时间段A组的CD3⁺、CD4⁺水平及CD4⁺/CD8⁺呈先降低后升高趋势,且术后7 d已恢复至术前水平;B组术后1 d、3 d、7 d的CD3⁺、CD4⁺水平及CD4⁺/CD8⁺明显低于A组(P＜0.05),两组CD8⁺水平相比无差异(P＞0.05) 。两组术后7 d的RBC、Hct、Hb分别较输血前下降（P＜0.05）,但两组间比较差异无统计学意义(P＞0.05);两组患者术后7 d的红细胞沉降率均升高,但A组低于B组(P＜0.05) ,两组患者术后的红细胞变形指数、平均血液黏度和红细胞刚性指数比较无差异 (P＞0.05) 。Kaplan-Meier检验结果显示,A组较B组生存率明显升高（P＜0.05）。结论：贮存式自体成分输血对胃肠肿瘤根治术患者红细胞沉降率、细胞免疫功能的影响程度较异体成分输血减轻,且贮存式自体成分输血可以明显提高患者的术后生存率。     

NLR、25-（OH）D3、IL-6、PCT与重症肺炎支原体肺炎患儿免疫功能和预后不良的关系研究

摘要 目的：探讨中性粒细胞与淋巴细胞比值（NLR）、25-羟维生素D3 [25-（OH）D3]、白细胞介素-6（IL-6）、降钙素原（PCT）与重症肺炎支原体肺炎（MMP）患儿免疫功能和预后不良的关系。方法：选取2019年2月至2021年12月我院收治的106例重症MMP患儿作为重症组,同期收治的101例轻症MMP患儿（轻症组）作为对照。检测外周血中性粒细胞计数、淋巴细胞计数、T淋巴细胞亚群以及血清25-（OH）D3、IL-6、PCT水平,计算NLR。分析NLR、25-（OH）D3、IL-6、PCT与T淋巴细胞亚群的相关性。重症MMP患儿治疗后随访半年,根据重症MMP患儿的预后情况分为预后良好组（75例）和预后不良组（31例）,多因素Logistic回归分析影响重症MMP患儿预后的因素。结果：重症组NLR、IL-6、PCT水平,CD8⁺高于轻症组（P＜0.05）,25-（OH）D3水平、CD3⁺、CD4⁺、CD4⁺/CD8⁺低于轻症组（P＜0.05）。NLR、IL-6、PCT水平与CD3⁺、CD4⁺、CD4⁺/CD8⁺呈负相关（P＜0.05）,与CD8⁺呈正相关（P＜0.05）;25-（OH）D3与CD3⁺、CD4⁺、CD4⁺/CD8⁺呈正相关（P＜0.05）,与CD8⁺呈负相关（P＜0.05）。多因素Logistic回归分析显示：肺大片实变影、NLR（较高）、IL-6（较高）、PCT（较高）是重症MPP患儿预后不良的危险因素（P＜0.05）,25-（OH）D3（较高）是保护因素（P＜0.05）。结论：重症MMP患儿NLR、IL-6、PCT水平升高,25-（OH）D3水平降低,且与细胞免疫功能低下以及预后不良有关,检测NLR、IL-6、PCT、25-（OH）D3有助于评估重症MMP患儿的预后。     

反复呼吸道感染儿童血清维生素A、维生素E水平与免疫球蛋白、T淋巴细胞亚群、NK细胞及骨密度的关系分析

摘要 目的：探讨反复呼吸道感染（RRTI）儿童血清维生素A、维生素E水平与免疫球蛋白（Ig）、T淋巴细胞亚群、NK细胞及骨密度的关系。方法：选择2018年2月至2020年12月我院儿科收治的107例RRTI患儿（感染组）和83例同期于我院体检的健康儿童（对照组）为研究对象,检测两组血清维生素A、维生素E水平、Ig水平,外周血T淋巴细胞亚群、NK细胞占比以及骨密度。分析维生素A、维生素E与Ig、T淋巴细胞亚群、NK细胞及骨密度的相关性。结果：感染组血清维生素A、维生素E、IgG、IgA、IgM及外周血CD3⁺T细胞百分比、CD4⁺T细胞百分比、CD3^-CD56⁺ NK细胞百分比、CD56brightNK细胞百分比、CD56dimNK细胞百分比、桡骨和胫骨骨密度均低于对照组（P＜0.05）,外周血CD8⁺T细胞百分比高于对照组（P＜0.05）。血清维生素A及维生素E水平与外周血CD8⁺T细胞百分比呈负相关（P＜0.05）,与IgG、IgA、IgM水平,外周血CD3⁺ T细胞百分比、CD4⁺T细胞百分比、CD3^-CD56⁺ NK细胞百分比、CD56brightNK细胞百分比、CD56dimNK细胞百分比、桡骨和胫骨骨密度呈正相关（P＜0.05）。结论：RRTI患儿血清维生素A、维生素E水平明显降低,且与免疫功能障碍和骨密度降低有关。     

认知行为疗法对腹腔镜肾癌根治术患者应激反应、心理弹性及免疫功能的影响

摘要 目的：探讨认知行为疗法对腹腔镜肾癌根治术患者给应激反应、心理弹性及免疫功能的影响,为改善腹腔镜肾癌根治术患者康复效果提供参考依据。方法：按抛掷硬币法将2019年1月-2022年12月南京鼓楼医院收治的80例腹腔镜肾癌根治术患者随机分为对照组和观察组,对照组40例患者行常规干预,观察组40例患者行认知行为疗法干预。比较两组患者临床基本指标、应激反应、心理弹性、免疫功能及生活质量等指标变化情况。结果：干预后,观察组排气时间、尿管留置时间、下床活动时间以住院时间均短于于对照组（P＜0.05）。两组干预后皮质醇、肾上腺素水平与心理弹性评分均较干预前升高（P＜0.05）,且观察组皮质醇、肾上腺素水平低于对照组,心理弹性评分高于对照组（P＜0.05）。两组干预后CD3⁺、CD4⁺及CD4⁺/CD8⁺水平较干预前升高,CD8⁺水平较干预前降低（P＜0.05）;且观察组CD3⁺、CD4⁺及CD4⁺/CD8⁺水平高于对照组,CD8⁺水平低于对照组（P＜0.05）。两组干预后生活质量各项评分均高于干预前（P＜0.05）,且观察组高于对照组（P＜0.05）。结论：认知行为疗法干预腹腔镜肾癌根治术患者不仅可有效改善患者负性情绪,提升其心里弹性,还可降低患者应激反应,提高机体免疫功能,加快其术后康复进程,值得临床借鉴应用。     

白蚁与动物及微生物的共生类型及其机制

综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生（宾主共栖和异种共栖）、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌（原生动物、细菌、真菌和放线菌）和外生菌（蚁巢伞菌等）间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用（如纤维素酶）及今后研究物种间的协同进化提供了基础资料。     

New amino-dithiaphospholanes and phosphoramidodithioites and their rhodium and iridium complexes

New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn₂NPSCH₂CH₂S^a(P-S^a) (Bn = benzyl, 4), Bn₂NPSCHCHS^a(CH₂)₃C^aH₂(P-S^a)(C^a-S^a) (6) and Bn₂NP(4-XC₆H₄OMe)₂ (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)₂] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl₂Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the ν_CO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The ¹J_PRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the ¹J_PSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh₃. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh₃.     

Astrocytes and Synaptosomes Transport and Metabolize Lactate and Acetate Differently

Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.     

Rapporteur report: Basics and technology and metrology and standards

The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.     

Relative and combined effects of ethanol and protein deficiency on strontium and barium bone content and fecal and urinary excretion

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.     

Prostaglandin and thromboxane production by human and guinea-pig macrophages and leucocytes

The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE₂, PGD₂, PGF_2α, TXB₂ and 6-keto-PGF_1α. In all types studied PGE₂ and TXB₂ were the major products formed. The identification of PGE₂ and TXB₂ was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.     

Chemokines and cytokines: axis and allies in asthma and allergy

Allergic asthma can be precipitated by many factors. For the atopic person, fungus, pollen, dust mites, cockroach antigens, and diesel exhaust are all agents that may trigger an allergic attack. Cytokines and chemokines are integral mediators of fungal asthma. From the earliest time points, they recruit and activate the cells required for the clearance of fungus as well as being critical factors involved in the immunopathology of this disease. In the final analysis, it is clear that these mediators can act to the benefit or the detriment of the host.     

Oxidation and nitration of ribonuclease and lysozyme by peroxynitrite and myeloperoxidase

In spite of the many studies on protein modifications by reactive species, knowledge about the products resulting from the oxidation of protein-aromatic residues, including protein-derived radicals and their stable products, remains limited. Here, we compared the oxidative modifications promoted by peroxynitrite and myeloperoxidase/hydrogen peroxide/nitrite in two model proteins, ribonuclease (6Tyr) and lysozyme (3Tyr/6Trp). The formation of protein-derived radicals and products was higher at pH 5.4 and 7.4 for myeloperoxidase and peroxynitrite, respectively. The main product was 3-nitro-Tyr for both proteins and oxidants. Lysozyme rendered similar yields of nitro-Trp, particularly when oxidized by peroxynitrite. Hydroxylated and dimerized products of Trp and Tyr were also produced, but in lower yields. Localization of the main modified residues indicates that peroxynitrite decomposes to radicals within the proteins behaving less specifically than myeloperoxidase. Nitrogen dioxide is emphasized as an important protein modifier.