早期口服补液对犬50%总体表面积烧伤休克期血流动力学和组织灌流的影响

目的 研究早期口服补液对犬50%总体表面积(TBSA)烧伤休克期血流动力学和组织灌流的影响.方法 成年雄性Beagle犬18只,先期无菌手术行颈总动脉、颈外静脉、胃、空肠及膀胱置管,24 h后用凝固汽油燃烧法造成其颈、背和胸、腹部约50%TBSA Ⅲ.烧伤.随机分为不补液(NR)、口服补液(OR)和静脉补液(IR)三组,每组6只.伤后第1个24 h NR组无治疗,OR和IR组于伤后30 min开始按Parkland公式分别从胃管和静脉输注葡萄糖.电解质溶液,伤后24 h起各组犬均实施静脉补液.测定犬伤前(0 h)和伤后2、4、8、24、48和72 h非麻醉状态下的平均动脉压(MAP)、全身血管阻力(SVR)、心输出量(CO)、左室内压最大变化速率(dp/dtmax)、尿量以及胃黏膜CO2分压(PgCO2)和小肠黏膜血流量(IMBF),并记录伤后72 h死亡率.结果 与伤前相比,各组犬MAP、CO、dp/dtmax,、IMBF和尿量在伤后2 h均大幅降低(P<0.01),而SVR和PgCO2显著升高.两补液组上述指标伤后8 h开始恢复,72 h IR组除IMBF外均恢复至伤前水平,但OR组CO、SVR及胃肠组织灌流指标仍差于伤前水平(P<0.01).NR组上述指标持续恶化,伤后24 h内无尿并全部死亡.OR组血液动力学和内脏组织灌流指标显著优于NR组,但差于IR组.伤后72 h死亡率NR组为6/6、OR组3/6,而IR组为0/6.结论 50%TBSA烧伤后早期口服葡萄糖-电解质溶液复苏效果虽差于静脉补液,但相比不补液,能显著改善血流动力学指标和内脏组织灌流,减少早期死亡,有潜力成为战争或灾害时静脉液体复苏的替代方法.     

On the psychosocial dimension of the IPPNW meeting in Coventry

Science and Conscience

In the Shadow of the Bomb: Oppenheimer, Bethe, and the Moral Responsibility of the Scientist By Silvan S. Schweber Princeton University Press, Princeton NJ, 2000, 260 pp., £15.95, ISBN 0–691–04989–0.

Sanctions

Iraq Under Siege: The Deadly Impact of Sanctions and War Edited by Anthony Amove Pluto, London, 2000, 224 pp., £10.99 pbk. ISBN 0–7453–16S9‐X, £35.00 hbk, ISBN 0–7453–1660–3.

Nurses at War

Nurses at War: Women on the Frontline 1939–45 By Penny Starns Sutton, Stroud, 2000, xvii + 174 pp., £19.99 hbk, ISBN 0–7509–23873.

Peace Education

Saying No to Violence — Children and Peace: Activities for a Peaceful World By Jan Melichar and Margaret Melicharova Peace Pledge Union, London, 2000, 58 pp., £9.99, ISBN 0–902680–46–3.     

Parametric uncertainty and disturbance attenuation in the suboptimal control of a non‐linear electrochemical process

The optimal control of the hydrogen evolution reactions is attempted for the regulation and change of set‐point problems, taking into account that model parameters are uncertain and I/O signals are corrupted by noise. Bilinear approximations are constructed, and their dimension eventually increased to meet accuracy requirements with respect to the trajectories of the original plant. The current approximate model is used to evaluate the optimal feedback through integration of the Hamiltonian equations. The initial value for the costate is found by solving a state‐dependent algebraic Riccati equation, and the resulting control is then suboptimal for the electrochemical process. The bilinear model allows for an optimal Kalman–Bucy filter application to reduce external noise. The filtered output is reprocessed through a non‐linear observer in order to obtain a state‐estimation as independent as possible from the bilinear model. Uncertainties on parameters are attenuated through an adaptive control strategy that exploits sensitivity functions in a novel fashion. The whole approach to this control problem can be applied to a fairly general class of non‐linear continuous systems subject to analogous stochastic perturbations. All calculations can be handled on‐line by standard ordinary differential equations integration software. Copyright © 2007 John Wiley & Sons, Ltd.     

Correlation between pathological types of parathyroid and clinical manifestations in patients with renal secondary hyperparathyroidism

Objective To analyze the correlation between the pathological types of parathyroid and clinical manifestations in patients with renal secondary hyperparathyroidism (SHPT), so as to improve the efficacy and safety of treatment. Methods The pathological and clinical data of 130 patients with renal SHPT and maintenance hemodialysis (MHD) who had undergone total parathyroidectomy with autotransplantation (TPTX+AT) were collected. A total of 545 parathyroid glands were obtained and 998 slices were made and read. According to the pathological types of parathyroid hyperplasia, the patients were divided into diffuse hyperplasia (DH) group, diffuse between hyperplasia and nodular hyperplasia (DH/NH) group as well as nodular hyperplasia (NH) group. The clinical and biochemical characteristics of different groups before and after operation (1-, 3-, 6-, 9-, 12-month) were compared and analyzed by statistical tests. Results (1) The preoperative status: the dialysis age, serum calcium as well as incidence of bone pain, skin itching and shorten height in the NH group were significantly higher than those in the DH group (all P＜0.05), and the serum phosphorus and iPTH in the NH group were significantly higher than those in DH and DH/NH group (all P＜0.05). (2) The postoperative status: the serum calcium of the NH group at 1-month was lower than that of the DH group, and the incidence of hypocalcemia of the NH group at 1-month was higher than that of the DH group (P＜0.05); the serum phosphorus at 3-, 6-, 9-month and iPTH at 1-, 3-month of the NH group were significantly lower than that of the DH group (all P＜0.05), and the serum phosphorus at 3-month and iPTH at 1-month of the NH group were lower than that of the DH/NH group (all P＜0.05). Among the 3 groups the serum phosphorus change from 1 to 12 months had difference (F=3.241, P=0.042), while the differences of serum calcium and iPTH changes were statistically insignificant. Conclusions The clinical manifestations, serum calcium, phosphorus and iPTH in patients with renal SHPT before and after TPTX+AT are closely related to the pathological types of parathyroid hyperplasia. Compared with the DH patients, before the operation the NH patients have longer dialysis age, more serious the clinical symptoms such as bone disease, higher calcium, phosphorus and iPTH, while greater reduction of the serum calcium, phosphorus and iPTH in the short term after operation.     

小肠移植后亚临床排斥反应的临床病理研究一例

目的 探讨小肠移植后亚临床型细胞性排斥反应(SCR)的临床表现、肠镜下改变和病理特点.方法 小肠移植1例,受者为女性,34岁,供者为男性.应用抗CD52单克隆抗体行诱导治疗,术后单用他克莫司(Tac)、无皮质激素的维持治疗方案.怀疑发生可疑排斥反应(IND)级至I级排斥反应时,提高血Tac浓度,行短程小剂量皮质激素治疗,排斥反应控制不佳时,则行甲泼尼龙冲击治疗;发生中度排斥反应时提高血Tac浓度,给予甲泼尼龙2 g,随后应用皮质激素递减方案.术后头2个月内,每周行2次肠镜和病理学检查,之后频次减为1次/周.结果 至随访结束患者已存活19个月(611 d),期间共发生有临床症状的急性排斥反应6次,亚临床排斥反应3次.3次亚临床排斥反应时,2次肠镜下未见明显改变,1次表现为斑点状的充血、水肿,放大肠镜下绒毛数量轻度减少.3次亚临床排斥反应的病理检查中,1次以黏膜上皮剥脱为主,隐窝上皮损伤较轻,组织学改变符合轻度急性排斥反应;而另2次以隐窝上皮的损伤为主,为可疑急性排斥反应.结论 SCR可能是临床排斥反应的早期阶段,无明显临床症状,肠镜下改变不明显,诊断主要依靠病理学检查,但必须排除移植肠血管病变、肠梗阻、各类炎症等术后并发症.     

Optimal control of non‐linear chemical reactors via an initial‐value Hamiltonian problem

The problem of designing strategies for optimal feedback control of non‐linear processes, specially for regulation and set‐point changing, is attacked in this paper. A novel procedure based on the Hamiltonian equations associated to a bilinear approximation of the dynamics and a quadratic cost is presented. The usual boundary‐value situation for the coupled state–costate system is transformed into an initial‐value problem through the solution of a generalized algebraic Riccati equation. This allows to integrate the Hamiltonian equations on‐line, and to construct the feedback law by using the costate solution trajectory. Results are shown applied to a classical non‐linear chemical reactor model, and compared against suboptimal bilinear‐quadratic strategies based on power series expansions. Since state variables calculated from Hamiltonian equations may differ from the values of physical states, the proposed control strategy is suboptimal with respect to the original plant. Copyright © 2005 John Wiley & Sons, Ltd.     

美国一流生命科学研究所所长群体的素质特征及启示

通过对美国10所一流生命科学研究所历任所长的教育经历、学术荣誉、职业经历等核心指标的分析,发现并提炼了该样本群体的素质特征,即学术精英为主体、任职前经历较丰富、以中老年男性为主,以及样本群体的素质特征趋势,即具有企业家背景的、女性的比例在增加,提出了鼓励企业家竞选所长以丰富经费来源、鼓励多学科背景的科学家竞选所长以适应知识融合趋势、选用更加灵活的研究所所长任期制度以形成优胜劣汰机制等生命科学研究所所长选任建议。