The effect of propofol and desflurane anaesthesia on human hepatic blood flow: a pilot study.

This study tested the hypothesis that propofol is associated with a higher hepatic blood flow in humans compared with desflurane. Using a cross over study design, 10 patients received first propofol and then desflurane, and a further 10 patients received desflurane and then propofol. Blood flow index in the right and middle hepatic veins, stroke volume index and cardiac index were assessed by transoesophageal echocardiography. Mean arterial blood pressure, stroke volume index and cardiac index were the same in both groups. Propofol was associated with significantly greater blood flow index in the right hepatic vein (median (IQR [range]) 199 (146-237 [66-388]) vs. 149 (112-189 [42-309]) ml.min(-1).m(-2); p = 0.005) and middle hepatic vein (150 (122-191 [57-341]) vs. 125 (92-149 [47-362]) ml.min(-1).m(-2); p < 0.001) compared with desflurane. In routine clinical conditions, propofol anaesthesia was associated with significantly greater hepatic blood flow than desflurane anaesthesia.

[Influence of fixation mechanism on changes of the supra- and infrarenal segment of the aorta after endovascular treatment of infrarenal aortic aneurysm]. / Einfluss des Verankerungsmechanismus auf Veränderungen des supra- und infrarenalen Aortensegments nach endovaskulärer Ausschaltung infrarenaler Bauchaortenaneurysmen.

INTRODUCTION: Dilatation of the infrarenal aortic segment determines the long-term outcome after endovascular repair of abdominal aortic aneurysms. This segment is crucial for sealing and preventing stent-graft migration. The purpose of this study was to evaluate influence of fixation mechanism on changes of supra- and infrarenal aortic diameters over a 10-year period. METHODS: We reviewed all our endovascular procedures for abdominal aortic aneurysms and follow-up CT scans between 1998 and 2008. Only patients with the three most frequently implanted self-expandable stent-graft types and a minimal follow-up of three months were included in this study. Further inclusion criteria were elective repair and follow-up at our department to consistent data formats. A total of 103 patients, 35 with suprarenal fixation without hooks (Medtronic Talent®, Medtronic World Medical, Sunrise, FL, USA), 29 with suprarenal fixation with hooks (Cook Zenith®, Cook Inc. Bloomington, IN, USA) and 39 with infrarenal fixation with anchors (Gore Excluder®, W. L. Gore & Associates, Flagstaff, Ariz, USA) met the inclusion criteria. All measurements were performed in duplicate by two different investigators to determine intra- and interobserver errors. Based on this error a minimal change of 2 mm of infrarenal aortic neck diameter was determined as aortic neck dilatation. RESULTS: During a mean follow-up time of 39.4 (3-108.8) months, infrarenal aortic neck dilatation was found in 28.57% in the Medtronic group, 10.26% in the Gore group and 31.03 in the Cook group. Suprarenal changes were 17.14%, 20.51% and 17.24%, respectively. Reduction of the maximal diameter could be achieved in 74.3% (Medtronic), 79.5% (Gore), and 75.8% (Cook). Seven of 23 patients with a notable dilatation of the infrarenal neck required reintervention. All of them were stent-grafts with suprarenal fixation. No statistical significance was found between the 3 groups regarding changes of suprarenal or infrarenal diameters or migration rates. CONCLUSION: Although no statistical significance was found among the groups, infrarenal fixation showed the lowest rate of infrarenal dilatation.

[Blunt and penetrating thoracic trauma]. / Stumpfes und penetrierendes Thoraxtrauma.

In most cases blunt chest trauma leads to fractures of the bony thorax, i. e. ribs. In the case of accompanying hemothorax or pneumothorax initial management consists of chest tube drainage by mini-thoracotomy. Subsequently patients with blunt chest trauma have to be transferred to the intensive care unit as these patients are at risk of pulmonary insufficiency or persistent blood loss via the chest tube. Injury to the great vessels or heart requires trauma care in specialized centers. Penetrating trauma is always surgically treated and the foreign body is removed in the operating room (OR). Life-threatening conditions, such as tension pneumothorax have to be treated by thorax drainage prior to hospital admission.

In vitro evidence for senescent multinucleated melanocytes as a source for tumor-initiating cells.

Oncogenic signaling in melanocytes results in oncogene-induced senescence (OIS), a stable cell-cycle arrest frequently characterized by a bi- or multinuclear phenotype that is considered as a barrier to cancer progression. However, the long-sustained conviction that senescence is a truly irreversible process has recently been challenged. Still, it is not known whether cells driven into OIS can progress to cancer and thereby pose a potential threat. Here, we show that prolonged expression of the melanoma oncogene N-RAS(61K) in pigment cells overcomes OIS by triggering the emergence of tumor-initiating mononucleated stem-like cells from senescent cells. This progeny is dedifferentiated, highly proliferative, anoikis-resistant and induces fast growing, metastatic tumors. Our data describe that differentiated cells, which are driven into senescence by an oncogene, use this senescence state as trigger for tumor transformation, giving rise to highly aggressive tumor-initiating cells. These observations provide the first experimental in vitro evidence for the evasion of OIS on the cellular level and ensuing transformation.

Cryopreserved porcine hepatocyte cultures.

Cryopreservation of freshly isolated hepatocytes is regarded the standard technique for long term storage of liver cells. Frankly, we were not successful in reproducing viability rates of about 70% of that which have been reported by most authors as results of various freezing protocols for hepatocyte suspensions. In fact, we saw mostly devastating results. We assume that intracellular ice crystal formation as well as osmotic changes during freezing and thawing of liver cells cause hazardous effects, especially on membranes of cells after enzymatic isolation, and, thus, generally result in a severe loss in number and impaired specific hepatocyte functions in subsequent culture. We tried to improve results by freezing cell cultures instead. We allowed hepatocytes to regain a more stable condition prior to storage and placed them in tissue flasks in a uniform configuration, rather than to pack cell suspensions in vials or bags under rather indefinable conditions. Porcine hepatocytes (viability 92+/-2%) were isolated from slaughterhouse organs and cultured in a double gel (sandwich) configuration. At day 3, cultures were rate controlled frozen (RCF) and stored in a cell bank for three hours (Group A) or 14 days at -80 degrees C (Group B), respectively. Non-frozen cells (NF) and cultures subjected to a linear freezing rate of -10 degrees C/min (LFR, Group C) with 3 h of storage served as controls from identical cell batches. Upon thawing, at day 2 of subsequent culture, fluorescence microscopy studies revealed a survival rate of 75+/-10% (mean+/-S.D.) in the RCF groups. Time of storage (3 h, 14 d) did not influence results. Survival in Group C was 10+/-5%. Cell integrity was measured by LDH-release, which indicated a larger damage of cells in the LFR group, and thereby resembled the morphological findings. Functional parameters, such as albumin synthesis and CYT P 450-activity were comparable to non-frozen liver cells at 48 h after thawing in the RCF groups (A + B), and showed significantly higher levels in these groups as compared to the LFR Group (C). We recommend to freeze hepatocytes in culture in a rate controlled fashion rather than cell suspensions. This way a cell bank of cryopreserved hepatocyte cultures for batch controlled investigations can be easily obtained. This could ameliorate the availability of rare (human) cell material and might also improve the quality of data generated from in vitro experiments in hepatology or pharmacology/toxicology with liver cells from identical sources. It remains to be seen whether this technique might also be of value in hybrid bioartificial liver devices to make these systems become readily available upon clinical demand.

Overlap between Atlantic bluefin tuna spawning grounds and observed Deepwater Horizon surface oil in the northern Gulf of Mexico.

The 2010 Deepwater Horizon oil spill impacted the northern Gulf of Mexico (GOM) during the spring spawning season of Atlantic bluefin tuna (BFT). Overlap between BFT spawning habitat and surface oil in the northern GOM was examined using satellite-derived estimates of oil coverage, and spawning habitat models. Results suggested that although eggs and larvae were likely impacted by oil-contaminated waters in the eastern GOM, high abundances of larvae were located elsewhere, especially in the western GOM. Overall, less than 10% of BFT spawning habitat was predicted to have been covered by surface oil, and less than 12% of larval BFT were predicted to have been located within contaminated waters in the northern GOM, on a weekly basis. Our results provide preliminary but important initial estimates of the effects of the spill on larval BFT mortality, as concern continues over the appropriate management responses to impacts of the spill.

[Fast track in thoracic surgery]. / Fast Track in der Thoraxchirurgie.

Patients undergoing thoracic surgery are threatened by pulmonary complications such as pneumonia and atelectasis. Age, preoperative FEV(1), operative time and extent of resection are predictors for adverse outcome. Reported morbidity after lung resection is as high as 42% and mortality up to 7%. Fast track in thoracic surgery aims at reducing morbidity and mortality rates after lung resection by introducing specific measures into the pre-, intra- and postoperative periods. Basic fast track elements in thoracic surgery are smoking cessation, preoperative physiotherapy, micronutrient supplementation, high thoracic epidural anesthesia, fluid restriction, early mobilization and enteral feeding. The effectiveness of these individual measures has been proven of value in perioperative care, however, evidence on multimodal therapy regimens in thoracic surgery is limited. In particular it remains to be elucidated which patients should be fast tracked in order to improve outcomes.

Experimental urinary stone formation following persorption.

The 'effect of Herbst' was combined with the production of renal calcium oxalate sediments by oral administration of ethyleneglycol and acidification with NH4Cl. This investigation was made to see whether persorbed bodies may form nuclei in crystallization in the genesis of stone. Lead sulphide crystals and 45Ca-labelled calcium oxalate crystals were used as persorbable model bodies. It became apparent that lead sulphide crystals given by mouth could be found both in the urine and kidneys, but these did not form nuclei in calcium oxalate sediments. Radioactive-labelled calcium, however, could be proved histoautoradiographically within the renal concretions. Our experiments showed that persorbed calcium oxalate crystals can represent nuclei for stone formation.

Lymph node staging in lung cancer using [18F]FDG-PET.

BACKGROUND: Mediastinal lymph node staging is essential to determine treatment options in patients with NSCLC. Positron emission tomography (PET) detects increased glucose uptake in malignant tissue using the glucose analogue 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG). PATIENTS AND METHODS: In the present study were evaluated 155 patients with focal pulmonary tumors who underwent both preoperative computed tomography (CT) and FDG-PET scanning (116 malignant and 39 benign lesions). RESULTS: Findings in 155 patients included 116 malignant and 39 benign lesions. For N-staging, FDG-PET showed a sensitivity of 88%, a specificity of 91%, and an accuracy of 89%. Corresponding figures for CT were 77%, 76%, and 77%, respectively. CONCLUSIONS: FDG-PET is an effective, noninvasive method for staging thoracic lymph nodes in patients with lung cancer and is superior to CT scanning in the assessment of hilar and mediastinal nodal metastases. With regard to operability, FDG-PET could differentiate reliable between patients with N1/N2 disease and those with unresectable N3 disease.