体外循环期间含三甲氧苄嗪低温保护液肺灌注对肺保护作用

目的：观察体外循环期间低温保护液肺动脉灌注对肺脏的保护作用以及添加细胞保护因子三甲氧苄嗪后对保护液作用的影响。方法：18只杂种犬随机分为对照组、试验组和TMZ组,每组6只。主动脉阻断后,对照组经右肺动脉灌注4C乳酸林格液,实验组经右肺动脉分别灌注4C肺保护液,TMZ组经右肺动脉分别灌注4C含三甲氧苄嗪肺保护液。体外循环结束后90min,取左右肺下叶背段组织做丙二醛（MDA）、髓过氧化物酶（MPO）、一氧化氮（NO）、含水量及组织病理学检查。结果：CPB后对照组肺组织MDA含量和MPO活性明显升高,加入肺保护荆的实验组明显下降,而TMZ组在CPB后虽有增高．但明显低于对照组和实验组。同时肺组织中的NO含量明显高于其它两组,肺组织含水量明显低于其他两组（P〈0．05）。光镜及透射电镜下观察肺泡及肺泡Ⅱ型上皮细胞。实验组、TMZ组右肺组织结构变化不明显。结论：CPB期间肺动脉灌注低温肺保护液可明显减轻CPB造成的肺组织损伤,而含三甲氧苄嗪的肺保护液具有更明显的优势。     

Mapping dynamic protein interactions in MAP kinase signaling using live-cell fluorescence fluctuation spectroscopy and imaging

Fluorescence correlation spectroscopy (FCS), fluorescence cross-correlation spectroscopy (FCCS), and photon counting histograms (PCH) are fluctuation methods that emerged recently as potentially useful tools for obtaining parameters of molecular dynamics, interactions, and oligomerization in vivo. Here, we report the successful implementation of FCS, FCCS, and PCH in live yeast cells using fluorescent protein-tagged proteins expressed from their native chromosomal loci, examining cytosolic dynamics and interactions among components of the mitogen activated protein kinase (MAPK) cascade, a widely occurring signaling motif, in response to mating pheromone. FCS analysis detailed the diffusion characteristics and mobile concentrations of MAPK proteins. FCCS analysis using EGFP and mCherry-tagged protein pairs observed the interactions of Ste7 (MAPK kinase) with the MAPKs, Fus3 or Kss1, and of the scaffold protein, Ste5, with Ste7 and Ste11 (MAPK kinase kinase) in the cytosol, providing in vivo constants of their binding equilibrium. The interaction of Ste5 with Fus3 in the cytosol was below the limit of detection, suggesting a weak interaction, if it exists, with K(d) >400-500 nM. Using PCH, we show that cytosolic Ste5 were mostly monomers. Artificial dimerization of Ste5, as confirmed by PCH, using a dimerizing tag, stimulated the interaction between Ste5 and Fus3. Native Ste5 was found to bind Fus3 preferentially at the cortex in pheromone-treated cells, as detected by fluorescence resonance energy transfer (FRET). These results provide a quantitative spatial map of MAPK complexes in vivo and directly support the model that membrane association and regulation of the Ste5 scaffold are critical steps in MAPK activation.     

Successful high-dose intravenous immunoglobulin therapy for a patient with fulminant myocarditis

A 45-year-old man developed fulminant myocarditis for which ventricular assist devices (intra-aortic balloon pumping and percutaneous cardiopulmonary support) were required for hemodynamic support. Echocardiography showed left ventricular akinesis and, since no improvement was noted on the following day, immunoglobulin (70 g/day for 2 days) was added to the therapy. The left ventricular ejection fraction increased to 25% and 40% at 12 and 36 h, respectively, representing a marked improvement in wall motion within a very short period. An endomyocardial biopsy specimen revealed focal lymphomononuclear infiltrate with adjacent myocytolysis, and acute lymphocytic myocarditis was diagnosed. Two days after administration of immunoglobulin, the serum level of interleukin-6 decreased rapidly from 180 to 5.9 pg/ml. In this patient, cardiac function improved immediately after immunoglobulin administration, suggesting the usefulness of this therapy. Three years after the diagnosis the patient is in good health, with steady normal left ventricular ejection fraction. We conclude that there are cases of acute myocarditis in which high-dose intravenous immunoglobulin therapy is effective.     

Wallerian degeneration of the corticospinal tracts: postmortem MR-pathologic correlations

Postmortem magnetic resonance (MR) images were correlated with the histological findings in two autopsy-proven cases of Wallerian degeneration of the corticospinal and corticopontine tracts associated with cerebral embolic infarction. T2 hyperintensities seen in Wallerian degeneration showed vacuolation of myelin in the early stage, and marked loss of myelin and axons with macrophages in the subacute and chronic stages. Similar T2 hyperintensities seen in the different stages of Wallerian degeneration reflect different histological findings.     

High-resolution ultrasound of peripheral neurogenic tumors

Peripheral nerve tumors are not frequent, but due to their association with a nerve they are somewhat special. They may be encountered incidentally during evaluation of a soft-tissue mass or when a nerve lesion is clinically suspected and the recognition of such a lesion and its differential diagnosis is key for successful therapy and patient prognosis. As sonography is often the first line modality in the work-up of a soft-tissue mass, the sonographer should be aware of the typical features of such lesions in order to arrive at the correct diagnosis, and this article tries to give an overview of the histological subtypes of peripheral nerve tumors and their sonographic characteristics.     

Increasing compression depth during manikin CPR using a simple backboard

BACKGROUND: The quality of external chest compressions (ECC) is influenced by the surface supporting the patient. The aim of this study was to compare chest compression depth with and without a rigid backboard. The authors hypothesized that the presence of a backboard would result in an increased depth of chest compressions. METHODS: A randomized, double-blinded, cross-over trial. We simulated in-hospital cardiac arrest using a resuscitation manikin placed in a standard hospital bed. In total, 23 hospital orderlies were randomly assigned to perform ECC for 2 min on two identical ResusciAnne manikins, under one of which a rigid backboard had been placed. Data were recorded using the Laerdal PC-Skill Reporting System. RESULTS: Mean chest compression depth increased from 43 to 48 mm (P < 0.0001) when a backboard was present (mean difference 5 mm, 95% CI 3.6-7.5 mm, SD 4.6). There was a significant increase in mean proportion of compressions >40 mm when using a backboard Mean 92% vs. 69%, P= 0.0007). No difference was found between the two groups in the following variables: duty cycle, compression rate, mean proportion of compressions of correct depth (40-50 mm) or proportion of compressions with incomplete release. CONCLUSIONS: Applying a backboard significantly increases depth of chest compressions during cardiopulmonary resuscitation when performed on a manikin model.     

Misplaced and dislodged endotracheal tubes may be detected by the defibrillator during cardiopulmonary resuscitation

We present two cases of unrecognized endotracheal tube misplacements in out-of-hospital cardiopulmonary resuscitation recognized by the analysis of transthoracic impedance. In Case 1, ventilation-induced changes in transthoracic impedance disappeared after an intubation attempt corresponding to oesophageal intubation. This was clinically recognized after several minutes, the endotracheal tube was repositioned and alterations in transthoracic impedance resumed. In Case 2, the initial ventilation-induced signal change following endotracheal intubation weakened after a few minutes. At that time, the defibrillator gave vocal and visual feedback to the rescuers on ventilatory inactivity, a pharyngeal air leak was discovered simultaneously and the tube was found to be dislodged. Continuous monitoring of transthoracic impedance provided by the defibrillator during cardiopulmonary resuscitation may contribute to the early detection of an initially misplaced or later dislodged endotracheal tube.     

What is optimal flow and how to validate this

Since the introduction of cardiopulmonary bypass, clinicians have tried to define the optimal blood flow for a given patient. The difficulty in determining a correct blood flow lies in the fact that cardiac surgery is done in a very inhomogeneous population, from neonates to the octogenarian, and often under non-physiologic conditions (hypothermia, hemodilution, low flow, etc.). Although clinicians acknowledge that maintaining a minimum oxygen delivery is more meaningful than using a fixed flow rate based on the metabolic needs of awake resting volunteers, the latter is most used in clinical practice. This is explained by the fact that no values are available on critical oxygen delivery for adequate tissue oxygenation under a given clinical condition. This was an overview of the relevant literature. In most centers, perfusionists use in-line monitoring, such as venous saturation or venous blood gases, for estimation of adequacy of tissue perfusion. Unfortunately, these oxygen-derived parameters have a poor correlation with anaerobic energy supply. Measurement of intermittent whole blood lactate concentration is used to compensate for this poor relationship, but as it monitors the concentration at given time points, it precludes optimally timely intervention by the perfusionist. The physiologic buffering by bicarbonate of the acid generated by converting pyruvate into lactate will produce carbon dioxide. As a consequence, carbon dioxide-derived parameters do have a good correlation with inadequate tissue perfusion. In-line monitoring of carbon dioxide production gives real-time information on tissue perfusion. Use of a standard reference flow for each patient is a poor option, because it does not reflect the metabolic need of the patient. Oxygen-derived parameters, such as venous saturation or partial venous oxygen tension, are poor predictors of anaerobic metabolism. A combination of intermittent whole blood lactate measurement with carbon dioxide-derived parameters predicts anaerobic energy production and allows proactive intervention by the perfusionist.     

Autotransfusion management during and after cardiopulmonary bypass alters fibrin degradation and transfusion requirements

The coagulation-fibrinolytic profile during cardiopulmonary bypass (CPB) has been widely documented. However, less information is available on the possible persistence of these alterations when autotransfusion is used in management of perioperative blood loss. This study was designed to explore the influence of autotransfusion management on intravascular fibrin degradation and postoperative transfusions. Thirty patients, undergoing elective primary isolated coronary bypass grafting, were randomly allocated either to a control group (group A; n=15) or an intervention group (group B; n=15) in which mediastinal and residual CPB blood was collected and processed by a continuous autotransfusion system before re-infusion. Intravascular fibrin degradation as indicated by D-dimer generation was measured at five specific intervals and corrected for hemodilution. In addition, chest tube drainage and need for homologous blood were monitored. D-dimer generation increased significantly during CPB in group A, from 312 to 633 vs. 291 to 356 ng/mL in group B (p = .001). The unprocessed residual blood (group A) revealed an unequivocal D-dimer elevation, 4131 +/- 1063 vs. 279 +/- 103 ng/mL for the processed residual in group B (p < .001). Consequently, in the first post-CPB period, the intravascular fibrin degradation was significantly elevated in group A compared with group B (p = .001). Twenty hours postoperatively, no significant difference in D-dimer levels was detected between both groups. However, a significant intra-group D-dimer elevation pre- vs. postoperative was noticed from 312 to 828 ng/mL in group A and from 291 to 588 ng/mL in group B (p < .01 for both). Postoperative chest tube drainage was higher in the patients from group A, which also had the highest postoperative D-dimer levels. Patients in group A perceived a higher need for transfusions of red cells suspensions postoperatively. These data clearly indicate that autotransfusion management during and after CPB suppresses early postoperative fibrin degradation. Keywords: cardiopulmonary bypass, cardiotomy suction, coronary surgery, autotransfusion, fibrin degradation.     

Preventing gaseous microemboli during blood sampling and drug administration: an in vitro investigation

The detection and prevention of gaseous microemboli (GMEs) during cardiopulmonary bypass has generated considerable interest within the cardiac surgical community. There have been several landmark papers that have used transcranial Doppler devices during cardiopulmonary bypass to detect gaseous microemboli activity in the patients' middle cerebral artery during perfusionist interventions. To determine if this source of emboli could be prevented, a shunt was developed between the oxygenator's sampling manifold and the oxygenator's venous line. This shunt bypassed the venous line and emptied into the oxygenator's integral cardiotomy. An in vitro experiment was performed using three open system oxygenators (Sorin Synthesis, Sorin PrimeOx2, and Terumo Capiox SX25) to compare post-arterial filter emboli detection using the Hatteland CMD20 Microbubble Detector under tightly controlled conditions. After injection of air through the sampling manifold, the PrimeOx2 and the Synthesis oxygenators had statistically significant fewer GMEs with the shunt used than when the shunt was not used. Using a shunt in the sampling manifold during perfusionist interventions will dramatically reduce or eliminate gaseous microemboli transmission to the patient during bypass with both the PrimeOx2 and Synthesis oxygenators. However, results indicate that further study of GME handling with all oxygenator's integral cardiotomies is warranted.