Measurement of the vasoconstrictive substances endothelin,angiotensin II,and thromboxane B2 in cold storage solution can reveal previous renal ischemic insults

In a rat model, the left kidney was subjected to 60 min of normothermic ischemia followed by 15 min of reperfusion, whereas the right kidney, serving as a paired control, was not rendered ischemic. Both kidneys were then perfused in situ with either Euro-Collins (EC) solution (n=12) or University of Wisconsin (UW) solution (n=6) for 10 min. Each kidney was then harvested and stored at 4°C in its respective solution. After 24 and 48 h of cold storage, the following vasoactive substances were measured in the preservation media: endothelin (ET), angiotensin II (A-II), thromboxane (B₂) (TxB₂), and prostaglandin I₂ (PGI₂). After 24 h in EC solution, left kidneys uniformly produced significantly higher concentrations of each vasoactive substance than right kidneys: ET 1.64±0.3 pg/ml vs 0.82±0.1 pg/ml (P0.009); A-II 20.8±6.2 pg/ml vs 7.75+2.3 pg/ml (P0.007); TxB₂ 100.8±17.7 pg/ml vs 40.1±11.7 pg/ml (P0.04); PGI₂ 638.3±41.1 pg/ml vs 318.3±36.4 pg/ml (P0.001), respectively. At 48 h, a similar pattern of results was obtained as the kidney continued to produce TxB₂ and prostacyclins during the 24–48 h period. In the UW solution, basal levels of ET and A-II were lower than those in EC solution, but similarly increased after initial ischemia. At 24 h, the concentrations produced by the left and right kidneys were as follows: ET 0.66±0.1 pg/ml vs 0.48±0.1 pg/ml (P0.14); A-II 10.36±3.7 pg/ml vs 2.14±0.7 pg/ml (P0.006); TxB₂ 178±53 pg/ml vs 52±23.1 pg/ml (P0.001); and PGI₂ 448.3±49 pg/ml vs 323±44.3 pg/ml (P0.01), respectively. After 48 h, the range of concentrations of each substance was similar to that obtained after 24 h. In further studies, the concentrations of ET and A-II were measured in solution previously used to preserve human kidneys (n=7). The mean concentration of ET and A-II in these samples was 3.82±1.14 pg/ml and 21.3±9.2 pg/ml, respectively, whereas in control media both substances were below the limits of detection. These results demonstrate that vasoconstrictive substances can be measured in the preservation media after a kidney has been stored cold and that higher concentrations are found when the organ has been subjected to prior normothermic ischemia. The measurement of these vasoactive substances before transplantation may reveal that the kidney has been subjected to previous ischemic events. Moreover, these vasoactive substances could be involved in the early recovery of renal function after kidney transplantation.     

Anaesthetic management of acute blunt thoracic trauma

Sunnybrook Health Science Centre is an adult regional trauma unit serving metropolitan Toronto and environs. We undertook a nvo-year retrospective review of patients admitted to our institution with blunt thoracic trauma. Three hundred and thirty-three patients with blunt trauma and an injury severity score (ISS) greater than 17 required emergency surgery. Of these, 208 had blunt thoracic injuries while 125 did not have chest injuries. Both groups were similar with respect to age but patients with thoracic trauma had a greater ISS. (P < 0.05) and greater intraoperative mortality (P < 0.01). The aetiology of the intraoperative deaths with one exception was exsanguination. Emergency thoracotomy or sternotomy indicated a poor prognosis with a mortality rate of 80%. The most common intraoperative problem was an elevated airway pressure. Awake intubation was undertaken in 77.5% of patients requiring anaesthesia and surgery because of the potentially compromised airways and difficult intubations due to the nature of the associated injuries. Finally, 74% of patients undergoing urgent surgery required mechanical postoperative ventilation. The presence of blunt chest trauma should be considered a marker of the severity of injury sustained by the patient.     

Randomized parallel study of doxorubicin plus paclitaxel and doxorubicin plus cyclophosphamide as neoadjuvant treatment of patients with breast cancer.

PURPOSE: This randomized, noncomparative, parallel-group study was designed to evaluate the pathologic complete response (pCR) rate of combined doxorubicin plus paclitaxel (AP) and doxorubicin plus cyclophosphamide (AC) as neoadjuvant chemotherapy in patients with previously untreated breast cancer who were unsuitable for conservative surgery. PATIENTS AND METHODS: A total of 200 patients with T2-3, N0-1, M0 disease were randomly assigned in a 2:1 ratio to receive preoperative chemotherapy with either doxorubicin 60 mg/m(2) plus paclitaxel 200 mg/m(2) as a 3-hour infusion (AP) or doxorubicin 60 mg/m(2) plus cyclophosphamide 600 mg/m(2) (AC) every 3 weeks for 4 courses followed by surgery. RESULTS: A pCR (eradication of invasive carcinoma in tumor and in axillary lymph nodes) was found in 16% and 10% of patients in the AP and AC arms, respectively, by study center pathologists, and in 8% and 6% of patients, respectively, by independent pathologists. Patients with pCRs tended to have unifocal disease, tumors with negative hormonal receptor status, and less differentiation (Scarff, Bloom, and Richardson scale grade 3). Breast-conserving surgery was performed in 58% and 45% of patients in the AP and AC arms, respectively. An objective clinical response was achieved in 89% of patients in the AP arm and 70% in the AC arm. At a median follow-up of 31 months, disease-free survival (DFS) was higher in patients who reached pCR versus those without pCR (91% v 70%). CONCLUSION: The encouraging pathologic and clinical responses of patients with breast cancer after neoadjuvant chemotherapy with doxorubicin plus paclitaxel warrant additional investigation of paclitaxel in the neoadjuvant setting of breast cancer management.     

Combined treatment with arsenic trioxide and all-trans-retinoic acid in patients with relapsed acute promyelocytic leukemia.

PURPOSE: Arsenic trioxide (ATO) is capable of inducing a high hematologic response rate in patients with relapsed acute promyelocytic leukemia (APL). Preclinical observations have indicated that all-trans-retinoic acid (ATRA) may strongly enhance the response to ATO. PATIENTS AND METHODS: Between 1998 and 2001, we conducted a randomized study of ATO alone versus ATO plus ATRA in 20 patients with relapsed APL, all previously treated with ATRA-containing chemotherapy. The primary objective was to demonstrate a significant reduction in the time necessary to obtain a complete remission (CR) in the ATO/ATRA group compared with the ATO group. Secondary objectives were safety and molecular response. RESULTS: The CR rate after one ATO with or without ATRA induction cycle was 80%. Clinical and pharmacokinetic observations indicated that the main mechanism of action of ATO in vivo was the induction of APL cell differentiation. Hematologic and molecular response, time necessary to reach CR, and outcome were comparable in both treatment groups. Of 16 CR patients, three patients who reached a molecular remission after one induction cycle had all received chemotherapy for a treatment-induced hyperleukocytosis. Three additional patients who received further additional ATO with or without ATRA cycles converted later to molecular negativity. CONCLUSION: ATRA did not seem to significantly improve the response to ATO in patients relapsing from APL. Other potential combinations, including ATO plus chemotherapy, have to be tested.     

小鼠胚胎干细胞磁标记共振成像的研究

目的 应用超顺磁氧化铁（SPIO）标记小鼠胚胎干细胞（ESC）,并行磁共振成像,为心肌细胞移植体内示踪作初步准备。方法 小鼠ESC及其分化的心肌细胞与SPIO孵育后行电镜分析、细胞内铁含量测定、[Ca^2＋]共聚焦测定和MR成像。结果 铁颗粒分布在胞质吞饮小泡内;使用转染技术的铁摄取高于未使用组;T2WI和T2^＊ WI扫描序列均见标记细胞呈信号下降,程度随标记浓度的增加而增强;T2^＊ WI图像信号强度变化更大。标记心肌细胞在T2^＊ WI序列也呈显著的低信号改变。结论 SPIO可有效标记ESC及其分化的心肌细胞,对细胞活性和分化能力无明显影响。常规1．5TMR仪可进行标记细胞成像。     

A Procedure to Measure the in-Situ Hygrothermal Behavior of Earth Walls

Rammed earth is a sustainable material with low embodied energy. However, its development as a building material requires a better evaluation of its moisture-thermal buffering abilities and its mechanical behavior. Both of these properties are known to strongly depend on the amount of water contained in wall pores and its evolution. Thus the aim of this paper is to present a procedure to measure this key parameter in rammed earth or cob walls by using two types of probes operating on the Time Domain Reflectometry (TDR) principle. A calibration procedure for the probes requiring solely four parameters is described. This calibration procedure is then used to monitor the hygrothermal behavior of a rammed earth wall (1.5 m × 1 m × 0.5 m), instrumented by six probes during its manufacture, and submitted to insulated, natural convection and forced convection conditions. These measurements underline the robustness of the calibration procedure over a large range of water content, even if the wall is submitted to quite important temperature variations. They also emphasize the importance of gravity on water content heterogeneity when the saturation is high, as well as the role of liquid-to-vapor phase change on the thermal behavior.