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AIM: To present a new technique of end-to-side, ductto- mucosa pancreaticojejunostomy with seromuscular jejunal flap formation, and insertion of a silicone stent. METHODS: We present an end-to-side, duct-to-mucosa pancreaticojejunostomy with seromuscular jejunal flap formation, and the insertion of a silicone stent. This technique was performed in thirty-two consecutive patients who underwent a pancreaticoduodenectomy procedure by the same surgical team, from January 2005 to March 2011. The surgical procedure performed in all cases was classic pancreaticoduodenectomy, without preservation of the pylorus. The diagnosis of pancreatic leakage was defined as a drain output of any measurable volume of fluid on or after postoperative day 3 with an amylase concentration greater than three times the serum amylase activity. RESULTS: There were 32 patients who underwent end-to-side, duct-to-mucosa pancreaticojejunostomy with seromuscular jejunal flap formation. Thirteen of them were women and 19 were men. These data correspond to 40.6% and 59.4%, respectively. The mean age was 64.2 years, ranging from 55 to 82 years. The mean operative time was 310.2 ± 40.0 min, and was defined as the time period from the intubation up to the extubation of the patient. Also, the mean time needed to perform the pancreaticojejunostomy was 22.7 min, ranging from 18 to 25 min. Postoperatively, one patient developed a low output pancreatic fistula, three patients developed surgical site infection, and one patient developed pneumonia. The rate of overall morbidity was 15.6%. There was no 30-d postoperative mortality. CONCLUSION: This modification appears to be a significantly safe approach to the pancreaticojejunostomy without adversely affecting operative time. © 2013 Baishideng. All rights reserved.

Background: Laparoscopic sleeve gastrectomy (LSG) is a promising procedure for the treatment of morbid obesity. The stomach is usually transected near the angle of His; hence, the lower esophageal sphincter (LES) may be affected with consequences on postoperative gastroesophageal reflux disease (GERD). The purpose of this study was to examine the effect of LSG on the LES and postoperative GERD. Methods: Severely obese asymptomatic patients submitted to LSG underwent esophageal manometry and GERD evaluation preoperatively and at least 6 weeks postoperatively. Data reviewed included patient demographics, manometric measurements, GERD symptoms, and pathology. Statistical analysis was performed by SPSS software. Results: Twelve male and eleven female patients participated in the study. Mean age was 38.5 ± 10.9 years, and initial body mass index was 47.9 ± 5.1 kg/m2. At follow-up examination, mean excess body mass index loss was 32.3 ± 12.7 %. The LES total and abdominal length increased significantly postoperatively, whereas the contraction amplitude in the lower esophagus decreased. There was an increase in reflux symptoms postoperatively (p < 0.009). The operating surgeon who mostly approximated the angle of His resulted in an increased abdominal LES length (p < 0.01). The presence of esophageal tissue in the specimen correlated with increased total GERD score (p < 0.05). Conclusions: LSG weakens the contraction amplitude of the lower esophagus, which may contribute to postoperative reflux deterioration. It also increases the total and the abdominal length of the LES, especially when the angle of His is mostly approximated. However, if this approximation leads to esophageal tissue excision, reflux is again aggravated. Thus, stapling too close to the angle of His should be done cautiously. © 2013 Springer Science+Business Media New York.

The concentrations of Cd, Cu and Zn in both the whole soft tissue and separate organs (gills, mantle, muscle and digestive gland) of wild bivalves (Mytilus galloprovincialis, Pinctada radiata, Venus verrucosa and Callista chione) from three different coastal microenvironments of Greece were monitored from 2003 to 2004. In parallel, by employing appropriate analytical protocols for metal partitioning, the labile fraction of the metals was determined in the dissolved phase, suspended particulate matter and sediments. Differences in the metal levels were detected both among the study areas as well as among the bivalves examined. Significant bioaccumulation was demonstrated regarding Zn in M. galloprovincialis specimens from the highly industrialized Gulf of Elefsis and Cd in P. radiata and V. verrucosa from the Maliakos Gulf, which is influenced by extended agricultural activity occurring at the neighbouring area and a river outflow. Data of the metal levels in the various environmental phases were correlated with their concentrations in bivalves' tissues. The clear relationships obtained in many cases among the labile metal concentrations and the bioaccumulated concentrations in bivalves point out that the labile fraction of a metal is the most bioavailable. The lack of positive correlation for C. chione confirms the occurrence of effective mechanisms of internal regulation of metal concentrations. © 2012 Springer Science+Business Media B.V.

Introduction: Colonic metastasis following curative surgery for renal cell carcinoma has rarely been described in the literature. Case Presentation: We present a case of a 64-year-old man who previously had a left nephrectomy for renal cell carcinoma. Five months post-operatively the patient presented with microscopic intestinal bleeding and anemia. Colonoscopic surveillance revealed a metastatic lesion in the ascending colon, and a right hemicolectomy was subsequently performed. Discussion: Colonic metastasis following resection for renal cell carcinoma is a rare entity, as evidenced by its lack of description in the literature. Imaging scans, such as computed tomography, have little diagnostic value and an increased medical suspicion is warranted for prompt diagnosis. © 2013 Versita Warsaw and Springer-Verlag Berlin Heidelberg.

Einleitung: In den letzten Jahrzenten haben sich die Staging- Methoden weiterentwickelt. Es gibt trotzdem ein kleines Anteil von Patienten mit lokoregionelen Metastasen oder Fernmetastasen eines Ősophagus Karzinoms, besonders bei Peritonealmetastasis, das übersehen wird, bevor eine operative[for full text, please go to the a.m. URL], 130. Kongress der Deutschen Gesellschaft für Chirurgie

Background: A number of experimental protocols have been used to try to reproduce the clinical scenarios of hemorrhagic shock. The present study reports on an experimental swine model of controlled hemorrhagic shock that incorporates microdialysis monitoring for the evaluation of tissue perfusion and oxygenation. The aim of our study was to provide a reproducible, accurate, and reliable model for the testing and evaluation of therapeutic interventions in the area of hemorrhagic shock. Methods: Landrace swine (n = 8) were subjected to controlled hemorrhagic shock, with a mean arterial pressure of 35 ± 5 as the endpoint. Six more pigs were used as the control group. Microdialysis monitoring of the tissue lactate/pyruvate ratio was used. The mean arterial pressure, heart rate, hematocrit, hemoglobin, and lactate/pyruvate ratio measurements were obtained just before (phase A) and 30 min after (phase B) hemorrhage in the study group; the control group underwent the same measurements at the corresponding points. Results: The mean arterial pressure, hematocrit, and hemoglobin were lower (P < 0.05) in the study group than in the control group at phase B and compared with the values for the study group at phase A. Also, the lactate/pyruvate ratio and heart rate were greater (P < 0.05) in the study group than in control group at phase B and compared with the values for the study group at phase A. Conclusions: This model of hemorrhagic shock is effective and correlates with the clinical parameters of tissue oxygenation, as documented by microdialysis. © 2013 Elsevier Inc. All rights reserved.

INTRODUCTION: Esophageal perforation after bariatric operations is rare. We report two cases of esophageal perforation after bariatric operations indicating the dangers of a common practice - like insertion of esophageal tubes - and we describe our management of that complication. PRESENTATION OF CASE: A 56 year old woman who underwent laparoscopic sleeve gastrectomy and a 41 year old woman who underwent laparoscopic adjustable gastric banding respectively. In both operations a bougie has been used and led to esophageal perforation. DISCUSSION: The insertion of bougie and especially of inflated bougie is a common practice. It is an invasive procedure that in most cases is performed by the anesthesiologist team. CONCLUSION: Bougie insertion is an invasive procedure with risks and should always be attempted under direct supervision of surgical team or should be inserted by a surgeon. © 2011 Published by Elsevier Ltd on behalf of Surgical Associates Ltd.

MAPK (mitogen-activated protein kinase) pathway is considered a control regulator in various malignant tumors but its role in esophageal carcinomas remains elusive. In our study, we examined the possible prognostic significance of MAPK pathway in human esophageal cancer. We searched for mutations in exons 18-21 of EGFR gene, codons 12 and 13 of K-RAS gene and exon 15 of B-RAF gene by high resolution melting analysis (HRMA) and pyrosequencing in 44 esophageal carcinomas. Immunohistochemistry was performed in 29 cases in order to evaluate expression levels of pERK (extracellular-signal regulated kinase). In one laser microdissected squamous cell carcinoma, a somatic K-RAS mutation at codon 12 was detected, whereas none of the cases displayed mutations in EGFR and B-RAF genes. Elevated nuclear as well as cytoplasmic pERK expression (100% and 62% of cases respectively) was observed independently of EGFR and B-RAF mutational status. Increasing pERK nuclear and cytoplasmic expression as well as the intensity of nuclear staining was found to be significantly correlated with tumor grade in univariate and multivariate statistical analysis. Our findings depict the presence of activated ERK despite the low frequency of upstream alterations, implicating ERK activation in the acquisition of a more aggressive phenotype in esophageal cancer. © 2012 Elsevier GmbH.

As of the writing of this report, Network Virtualization is a domain undergoing innovation and development. It is a domain concerned with the networking aspect of cloud computing, whose popularity has skyrocketed in the previous years. The Grid computing community is investigating cloud computing services, adding their own priorities in what they expect from network virtualization. This report describes the design and implementation of a solution for network provisioning in cloud infrastructures, which tries to combine open-source cloud platforms with network topology management and hardware configuration. The project was the final project for the Stan Ackerman's Institute Software Technology program, Eindhoven University of Technology, and was performed on behalf of Nikhef, a Grid infrastructure provider. This report is of technical nature and targets an audience familiar with object-oriented software and networking. For an elaboration of the needs the system fulfills, readers should refer to Chapters 2-3. The design and deployment of the system is described in Chapters 4-6. Lastly, for results and conclusions, the reader should refer to Chapter 8.

Introduction. Intramuscular myxoma is a rare benign soft tissue tumor. The lack of specific symptoms and widely used laboratory tests makes the diagnosis quite difficult. We present a case of an Intramuscular myxoma associated with an increased carbohydrate antigen 19.9 level. To the best of our knowledge, there have not been any reported cases of an association of Intramuscular myxoma with tumor markers in the literature. Case presentation. A 45-year-old Caucasian woman presented to our department for resection of a mass in her left groin area, discovered incidentally on a triplex ultrasonography of her lower extremities. The diagnosis of Intramuscular myxoma was confirmed on histopathology after the complete surgical excision of the tumor. On laboratory examination, the serum level of carbohydrate antigen 19.9 was found to be elevated, but it returned to normal six months after resection of the mass. Conclusion: Carbohydrate antigen 19.9 is a tumor marker that increases in a variety of malignant and benign conditions. After the exclusion of all other possible reasons for carbohydrate antigen 19.9 elevation, we assumed a possible connection of carbohydrate antigen 19.9 elevation and Intramuscular myxoma, an issue that requires needs further investigation. © 2011 Theodorou et al; licensee BioMed Central Ltd.

The propagation stage of uncertainty evaluation, known as the propagation of distributions, is in most cases approached by the GUM (Guide to the Expression of Uncertainty in Measurement) uncertainty framework which is based on the law of propagation of uncertainty assigned to various input quantities and the characterization of the measurand (output quantity) by a Gaussian or a t-distribution. Recently, a Supplement to the ISO-GUM was prepared by the JCGM (Joint Committee for Guides in Metrology). This Guide gives guidance on propagating probability distributions assigned to various input quantities through a numerical simulation (Monte Carlo Method) and determining a probability distribution for the measurand. In the present work the two approaches were used to estimate the uncertainty of the direct determination of cadmium in water by graphite furnace atomic absorption spectrometry (GFAAS). The expanded uncertainty results (at 95% confidence levels) obtained with the GUM Uncertainty Framework and the Monte Carlo Method at the concentration level of 3.01 μg/L were ±0.20 μg/L and ±0.18 μg/L, respectively. Thus, the GUM Uncertainty Framework slightly overestimates the overall uncertainty by 10%. Even after taking into account additional sources of uncertainty that the GUM Uncertainty Framework considers as negligible, the Monte Carlo gives again the same uncertainty result (±0.18 μg/L). The main source of this difference is the approximation used by the GUM Uncertainty Framework in estimating the standard uncertainty of the calibration curve produced by least squares regression. Although the GUM Uncertainty Framework proves to be adequate in this particular case, generally the Monte Carlo Method has features that avoid the assumptions and the limitations of the GUM Uncertainty Framework. © 2010 Elsevier B.V. All rights reserved.

The concentration dependence of self-diffusivity is investigated by means of a novel method, extending our previously developed second-order Markov process model to periodic media. Introducing the concept of minimum-crossing surface, we obtain a unique decomposition of the self-diffusion coefficient into two parameters with specific physical meanings. Two case studies showing a maximum in self-diffusivity as a function of concentration are investigated, along with two cases where such a maximum cannot be present. Subsequently, the method is applied to the large cavity pore network of the ITQ-1 (Mobil tWenty tWo, MWW) zeolite for methane (displaying a maximum in self-diffusivity) and carbon dioxide (no maximum), explaining the diffusivity trend on the basis of the evolution of the model parameters as a function of concentration. J Chem Phys

Introduction: The purpose of this study was to evaluate the incidence of TBI in Greece and to provide evidence on the epidemiologic characteristics of the disease. Patients and methods: This is a prospective observational study initiated by the Hellenic Society of Trauma and Emergency Surgery. Thirty hospitals participated in the registry. All trauma patients requiring admission transfer to a higher level centre and those who arrived dead were included in the study. This report evaluated the epidemiologic characteristics of patients with brain trauma, the cause and the severity of the injury and the final outcome. Results: Eight thousand eight hundred and sixty-two patients were included in the registry. Of them, 3383 had at least one brain injury. There were 2451 males and 932 females. Traffic accidents were the leading cause of TBI (54.1%), followed by falls (27.7%). The most affected age group was the 15-44 year olds (48.0%), but TBIs were more lethal in the 45-64 age group (17.8%). Interestingly, a 3.4% mortality was recorded if a TBI was present, even if ISS was relatively low (0-9 ISS group). Conclusion: TBI is a major element of trauma. Knowledge of the epidemiologic characteristics of the disease is imperative for adequate planning and future quality assessment. © 2010 Informa UK Ltd All rights reserved.

Background: Nosocomial infections are a frequent and continuously increasing problem worldwide, have a rapidly increasing multidrug resistance to antibiotics, and are associated with significant morbidity and mortality. Objective: Our objectives were to evaluate Acinetobacter baumannii infection incidence in our surgical intensive care unit (SICU), the clinical features and outcome of these patients, and, particularly, to investigate predictors of A baumannii infection-related mortality. Methods: Ours was a prospective study of all patients with ICU-acquired A baumannii infection from January 1, 2006, to December 31, 2007. Results: Among 680 patients, 60 (8.8%) sustained A baumannii infection. Mean age was 68.4 ± 6.2 years, Acute Physiology and Chronic Health Evaluation (APACHE) II score on SICU admission 20.6 ± 8.1 and Sequential Organ Failure Assessment (SOFA) score on infection day 9.5 ± 4.2 (women: 50%). Multidrug resistance, morbidity, and mortality were 45%, 65%, and 46.6% (n = 28), respectively. In multivariate analysis, age (P = .03; odds ratio [OR], 1.13; 95% confidence interval [CI]: 1.018-1.259), acute renal failure (P = .001; OR, 17.9; 95% CI: 6.628-75.565), and thrombocytopenia (P = .03; OR, 26.4; 95% CI: 1.234-56.926) complicating the infection and subsequent Enterococcus faecium bacteremia (P = .01; OR, 3.5; 95% CI: 1.84-6.95) were mortality predictors. Conclusion: A baumannii infections are frequent and associated with high drug multiresistance, morbidity, and mortality. Age, renal failure, thrombocytopenia, and subsequent E faecium bacteremia were predictors of A baumannii infection-associated mortality. Copyright © 2010 by the Association for Professionals in Infection Control and Epidemiology, Inc.

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The molecular motion of methane (CH(4)) and carbon dioxide (CO(2)) sorbed in the two independent pore networks, being termed hereafter as large cavity (LC) and sinusoidal channel (SC) regions of the siliceous MWW-framework-type zeolite ITQ-1, is studied by means of atomistic computer simulation. Equilibrium molecular dynamics predicts different loading dependences for the two gases, for both the self and the collective (Maxwell-Stefan) diffusion coefficients; in particular, the transport coefficients of CH(4) go through a maximum as its loading in the zeolite increases, whereas CO(2) dynamics exhibits the decreasing trend with loading usually observed in nanoporous materials. The different loading dependence of the self-diffusivity for the two sorbates is attributed to their different probability density distribution within the supercages in the LC system of the ITQ-1 unit cell. The composition and occupancy dependence of the self-diffusivity of each component in their binary mixtures can be explained in terms of the selectivity for CO(2) sorption thermodynamics in the zeolite. The collective diffusivity loading dependence of the single and binary sorbate system is explainable on the basis of the strength of intermolecular interactions along the diffusion direction connecting the supercages by invoking the quasichemical mean field theory. J Phys Chem B

Introduction. Low anterior resection is usually the procedure of choice for rectal cancer, but a series of complications often accompany this procedure. This case report describes successful management of an intricate anastomotic leak after a low anterior resection. Case presentation. A 66-year-old Caucasian man was admitted to our hospital and diagnosed with a low rectal adenocarcinoma. He underwent a low anterior resection but subsequently developed fecal peritonitis due to an anastomotic leak. He was operated on again but developed abdominal compartment syndrome, multi-organ failure and sepsis. He was aggressively treated in the intensive care unit and in the operating room. Overall, the patient underwent four laparotomies and stayed in the intensive care unit for 75 days. He was discharged after 3 months of hospitalization. Conclusion. Abdominal compartment syndrome may present as a devastating complication of damage control laparotomy. Prompt recognition and goal-directed management are the cornerstones of treatment. © 2009 Toutouzas et al; licensee BioMed Central Ltd.

Introduction. Although mural thrombus in an abdominal aortic neurysm is frequent and its role has been studied extensively, complete thrombosis of an abdominal aneurysm is extremely rare and its natural history in relation to the risk of rupture is not known. The case of a patient with a completely thrombosed infrarenal aneurysm is presented along with a literature review. Case presentation. We report the case of a 56-year-old Caucasian man with an infrarenal abdominal aortic aneurysm, presenting at our hospital due to critical ischemia of his right lower limb. Computed tomography and angiography demonstrated complete aneurysm thrombosis and obstruction of both common iliac arteries. Conclusion. During the operation, systolic and mean intrathrombotic pressures, measured in different levels, constituted 74.5-90.2% and 77.5-92.5% of systolic and mean intraluminal pressure and 73-88.4% and 76.5-91.3% of systemic pressure, respectively. Our findings show that there may be a continuing risk of rupture in cases of a thrombosed abdominal aortic aneurysm. © 2009 Filis et al; licensee BioMed Central Ltd.

A new "mesoscopic" stochastic model has been developed to describe the diffusive behavior of a system of particles at equilibrium. The model is based on discretizing space into slabs by drawing equispaced parallel planes along a coordinate direction. A central role is played by the probability that a particle exits a slab via the face opposite to the one through which it entered (transmission probability), as opposed to exiting via the same face through which it entered (reflection probability). A simple second-order Markov process invoking this probability is developed, leading to an expression for the self-diffusivity, applicable for large slab widths, consistent with a continuous formulation of diffusional motion. This model is validated via molecular dynamics simulations in a bulk system of soft spheres across a wide range of densities. J Chem Phys

To evaluate the impact of the perioperative administration of norepinephrine on the perfusion of the esophageal graft. This is an experimental study. Six swine underwent transhiatal esophagectomy; the stomach was used to replace the resected esophagus. We provoked hemorrhagic shock to the animals and then we administered noradrenaline to restore the blood pressure. We monitored the graft perfusion perioperatively using the technique of microdialysis. In all animals, the graft experienced severe hypoperfusion after the administration of noradrenaline that was statistically significant. Our data support the hypothesis that norepinephrine should be used with extreme caution in the perioperative setting after esophagectomy. Further studies, however, will be required to evaluate the clinical significance of this finding. © 2008 The Society for Surgery of the Alimentary Tract.

Introduction: Gastrointestinal tract small cell carcinoma is an infrequent and aggressive neoplasm that represents 0.1-1% of gastrointestinal malignancies. Very few cases of small cell esophageal carcinoma arising in Barrett's esophagus have been reported in the literature. An extremely rare case of primary small cell carcinoma of the distal third of the esophagus arising from dysplastic Barrett's esophagus is herein presented. Case presentation: A 62-year-old man with gastroesophageal reflux history presented with epigastric pain, epigastric fullness, dysphagia, anorexia, and weight loss. Esophagogastroscopy revealed an ulceroproliferative, intraluminar mass in the distal esophagus obstructing the esophageal lumen. Biopsy showed small cell esophageal carcinoma. Contrast-enhanced chest and abdominal computed tomography demonstrated a large tumor of the distal third of the esophagus without any lymphadenopathy or distant metastasis. Preoperative chemotherapy with cisplatine and etoposide for 3 months resulted in a significant reduction of the tumor. After en block esophagectomy with two field lymph node dissection, proximal gastrectomy, and cervical esophagogastric anastomosis, the patient was discharged on the 14th postoperative day. Histopathology revealed a primary small cell carcinoma of the distal third of the esophagus arising from dysplastic Barrett's esophagus. The patient received another 3 month course of postoperative chemotherapy with the same agents and remained free of disease at 12 month review. Conclusion: Although small cell esophageal carcinoma is rare and its association with dysplastic Barrett's esophagus is extremely infrequent, the high carcinogenic risk of Barrett's epithelium should be kept in mind. Prognosis is quite unfavorable; a better prognosis might be possible with early diagnosis and treatment strategies incorporating chemotherapy along with oncological radical surgery and/or radiotherapy as part of a multimodality approach. Since treatment protocols are not well established due to the rarity of the neoplasm, multi-institutional studies are needed to obtain sufficiently large populations for investigation and optimization of therapy of the disease. © 2008 Markogiannakis et al; licensee BioMed Central Ltd.

Objectives: This study was designed to evaluate Acinetobacter baumannii infections incidence in our Surgical Intensive Care Unit, clinical features and outcome of these patients, and multi-resistance incidence to identify predictors of such a resistance. Methods: Prospective study of all patients with ICU-acquired Acinetobacter baumannii infection from June 1, 2003 to May 31, 2005. Patients with multi-resistant infection, susceptible exclusively to colistin, were compared with those sustaining non-multi-drug resistant infection. Results: Among 411 patients, 52 (12.6%) developed Acinetobacter infection. Their mean age was 66.3 ± 8.4 years and APACHE II 20.4 ± 7.3 (men: 51.9%). Infection sites were: bloodstream (46.2%), respiratory tract (32.7%), central venous catheter (11.5%), surgical site (7.7%), and urinary tract (1.9%). High multi-resistance (44.2%), morbidity (63.4%), and mortality (44.2%) were identified. Colistin was the most effective antibiotic (100% susceptibility), whereas resistance against all other antibiotics was >60%. Previous septic shock (p = 0.04), previous adult respiratory distress syndrome (ARDS) (p = 0.01), number of previous antibiotics (p = 0.01), previous aminoglycoside use (p = 0.04), and reoperation (p = 0.01) were risk factors for multi-resistance in univariate analysis. Morbidity in the multi-resistant group was significantly higher than the non-multi-resistant group (82.6% vs. 48.2%, p = 0.02). Mortality in the multi-resistant group also was higher; however, this difference did not marginally reach statistical significance (60.8% vs. 31.1%, p = 0.06). Multivariate analysis identified previous septic shock (p = 0.04; odds ratio (OR), 9.83; 95% confidence interval (CI), 1.003-96.29) and reoperation (p = 0.01; OR, 8.45; 95% CI, 1.52-46.85) as independent predictors of multi-resistance. Conclusion: Acinetobacter baumannii infections are frequent and associated with high morbidity, mortality, and multi-resistance. Avoidance of unnecessary antibiotics is a high priority, and specific attention should be paid to patients with previous ARDS and, particularly, previous septic shock and reoperation. When such risk factors are identified, colistin may be the only appropriate treatment. © 2008 Société Internationale de Chirurgie.

Background: An umbilical metastatic lesion is called 'Sister Mary Joseph's nodule'. It is an uncommon clinical or radiographic finding, and it is rare as the first sign of a malignant disease. Case presentation: We report three cases of Sister Mary Joseph's nodule. In the three cases presented, the primary tumor was an adenocarcinona of the sigmoid colon, a carcinoma of the bladder, and an adenocarcinoma of the gallbladder, respectively. Conclusion: The differential diagnosis of an umbilical lesion should always include metastatic disease apart from benign lesions and primary neoplasms. © 2008 Larentzakis et al; licensee BioMed Central Ltd.

Objective In this prospective observational study we present preliminary results of a modification of the translaryngeal tracheostomy technique that was introduced by Fantoni in 1997. The study was conducted in a five-bed surgical intensive care unit of a university teaching hospital. Patients and Methods The study included 14 consecutive surgical patients (8 men, 6 women) who underwent a modified translaryngeal tracheostomy in a 6-month period. In our modification of the technique, we keep the basic principle of the inside-to-outside approach of the Fantoni technique, and combine it with a blind needle insertion, as reported in the classic subcricoid retrograde intubation technique. The technique that we use involves two medical doctors and a nurse. Results Mean patient age was 68.9 years (range: 31-85 years) and mean APACHE II score was 15.8 (range: 6-31). Mean operative time for the procedure was 15.2 min (range: 11.5-22 min). Eight of the patients died during the postoperative course in the ICU from causes relevant to their surgical pathology. One patient survived to be discharged from the ICU but died of an acute myocardial infraction later in the same hospital stay. Five patients survived to be discharged from the hospital. Conclusions The modified translaryngeal tracheostomy seems to be as reliable and safe as the original technique. In addition, the modified technique is faster and can be performed without the use of an endoscope.

Mesoscopic kinetic Monte Carlo simulations and pulsed field gradient nuclear magnetic resonance (PFG NMR) measurements are compared in order to investigate the transport of ethane in a bed of NaX crystals. A novel molecular mechanics particle-based reconstruction method is employed for the digital representation of the bed, enabling for the first time a parallel study of the real system and of a computer model tailored to reproduce the void fraction, particle shape and average size of the real system. Simulation of the long-range diffusion of ethane in the bed over the Knudsen, transient, and molecular diffusion regimes is consistent with the PFG NMR measurements in yielding tortuosity factors which depend upon the regime of diffusion; more specifically, tortuosity factors defined in the conventional way are higher in the Knudsen than in the molecular diffusion regime. Detailed statistical analysis of the computed molecular trajectories reveals that this difference arises in a nonexponential distribution of the lengths and in a correlation between the directions of path segments traversed between collisions with the solid in the Knudsen regime. When the Knudsen tortuosity is corrected to account for these features, a single, regime-independent value is obtained within the error of the calculations. J Chem Phys

Background: Extra-adrenal, intra-abdominal paraganglioma constitutes a rare neoplasm and, moreover, its location in the greater omentum is extremely infrequent. Case presentation: A 46-year-old woman with an unremarkable medical history presented with an asymptomatic greater omentum mass that was discovered incidentally during ultrasonographic evaluation due to menstrual disturbances. Clinical examination revealed a mobile, non-tender, well-circumscribed mass in the right upper and lower abdominal quadrant. Blood tests were normal. Contrast-enhanced abdominal computed tomography (CT) scan confirmed a huge (15 × 15 cm), well-demarcated, solid and cystic, heterogeneously enhanced mass between the right liver lobe and right kidney. Exploratory laparotomy revealed a large mass in the greater omentum. The tumor was completely excised along with the greater omentum. Histopathology offered the diagnosis of benign greater omentum paraganglioma. After an uneventful postoperative course, the patient was discharged on the 4th postoperative day. She remains free of disease for 2 years as appears on repeated CT scans as well as magnetic resonance imaging (MRI) and scintigraphy performed with radiotracer-labeled metaiodobenzyl-guanidine (MIBG) scans. Conclusion: This is the second reported case of greater omentum paraganglioma. Clinical and imaging data of patients with extra-adrenal, intra-abdominal paragangliomas are variable while many of them may be asymptomatic even when the lesion is quite large. Thorough histopathologic evaluation is imperative for diagnosis and radical excision is the treatment of choice. Since there are no definite microscopic criteria for the distinction between benign and malignant tumors, prolonged follow-up is necessary. © 2007 Archontovasilis et al; licensee BioMed Central Ltd.

Acute pretreatment tumor lysis syndrome is a rare complication of cancer. Early recognition and aggressive management are mandatory for prevention of the adverse sequelae of the syndrome. Here we present 2 cases of pretreatment tumor lysis syndrome, concluding that this clinical entity should be in the differential diagnosis of acute renal failure associated with malignancy, as early recognition is in fact the mainstay of treatment.

The aim of Ms study was to evaluate the safety, efficacy, and effects of administration of very high doses of norepinephrine (>4 μg kg-1 min-1) in catecholamine-resistant septic shock. We reviewed the charts of all patients with nonresponding to commonly used norepinephrine doses (≤4 μg kg-1 min-1) septic shock from January 1999 to December 2002 in our Surgical Intensive Care Unit. All patients were treated with high norepinephrine doses (>4 μg kg-1 min-1), after initial resuscitation, so as to achieve a mean arterial pressure higher than or equal to 65 mmHg. During this 4-year period, 12 consecutive patients with catecholamine-resistant septic shock were included in our study. When compared with the values obtained prior to the administration of very high norepinephrine doses, the values of mean arterial pressure (p = 0.003) and systemic vascular resistance (p = 0.002) significantly increased after the administration of such doses, and additionally, lactate concentrations (p = 0.003) decreased. In contrast, no significant changes were observed regarding mean central venous pressure, pulmonary capillary wedge pressure, and pulmonary arterial pressure. Administration of high norepinephrine doses in our patients resulted in a survival rate of 33.4%. Management of catecholamine-resistant septic shock patients poses a challenging problem. Administration of very high norepinephrine doses is safe and effective and may improve survival of these patients with otherwise extremely high mortality rates. © 2006 Prous Science. All rights reserved.

Objective: This prospective randomized study was conducted in order to define the contribution of the generated oxygen and nitrogen reactive species on postlobectomy morbidity and mortality. Patients and methods: Between 2001 and 2003, 132 patients with non-small cell lung cancer (NSCLC) were prospectively studied. The patients were grouped according to one-lung ventilation (OLV) use or not and to the duration of lung’s atelectasis. Group A included 50 patients with confirmed non-small cell lung cancer who were subjected to lobectomy without one-tung ventilation. Group B included 30 patients subjected to 60 min OLV. Group C included 30 patients subjected to 90 min OLV. Group D included 22 patients subjected to 120 min OLV. Preoperative, intraoperative and postoperative strict blood sampling protocol was followed. Malondiadehyde (MDA) plasma levels were measured. The groups were statistically compared for the occurrence of postoperative complications. OLV (groups B-D) along with other clinical parameters were entered in multivariate analysis as risk factors for complication development. Measurements and results: Comparison of group A with groups B-D (OLV) documented significant increase (p < 0.001) of MDA levels during lung reexpansion. The magnitude of oxidative stress was related to OLV duration (group D > group C > group B, all p < 0.001). Univariate analysis disclosed a higher incidence of acute respiratory failure, cardiac arrhythmias and pulmonary hypertension in group D. Multivariate analysis revealed OLV as an independent risk factor for postoperative development of cardiac arrhythmias and pulmonary hypertension. Conclusion: Protracted (> 1 h) OLV should be considered a potential cause for cardiovascular complications through the generation of severe oxidative stress due to lung reexpansion. (c) 2006 Published by Elsevier B.V.

New quasi-elastic neutron scattering (QENS) data are presented for the self-diffusion of normal alkanes up to hexadecane in the zeolite silicalite at low occupancy. Measured diffusivities at 300 K are higher than in Na-ZSM-5 and agree with the predictions of molecular dynamics and a hierarchical transition-state theory/Brownian dynamics conducted on the same systems. Activation energies for diffusion are around 5 kJ/mol for C1-C6 but rise with carbon number for C8-C16 to approximately 15 kJ/mol for C16. An explanation is suggested by the hierarchical simulation, which finds that C1-C6 tend to reside entirely within the interiors of single channel segments and diffuse through jumps across energetically less favorable channel intersections, while longer molecules straddle channel intersections and must undergo conformational rearrangements in order to diffuse. The agreement between QENS and simulations reflects that the two methods probe motion over the same small (nm) length scales. Self-diffusivities measured by pulsed field gradient nuclear magnetic resonance (PFG-NMR) in the same systems are appreciably lower. This is because PFG-NMR probes motion over significantly longer (m) length scales and is therefore more sensitive to defects in the silicalite crystals.

Thorough knowledge of laparoscopic suturing is of great importance to the laparoscopic surgeon, especially during the performance of advanced laparoscopic procedures. Intracorporeal and extracorporeal knot tying enhances the technical capabilities of the laparoscopic access, thus extending the spectrum of laparoscopic procedures to that of open surgery. We describe herein a new extracorporeal knot designed with an emphasis on simplicity and safety. (c) 2006 Excerpta Medica Inc. All rights reserved.

Laparoscopic vertical banded gastroplasty (LVGB), is a safe and efficient bariatric operation, with low intraoperative complications. We report an unusual cause of conversion of a LVGB to an open procedure due to the fracture of the spike of the circular stapler during gastric penetration.

Objective: The authors conducted a prospective analysis in order to investigate through lipid peroxidation metabolites the generation of oxygen free radicals after one-lung ventilation (OLV). Methods: From 2001 to 2003, 212 patients were prospectively studied for lung reexpansion/reperfusion injury. They were classified in six groups. Group A, non-OLV lobectomy group; B, OLV pneumonectomy group; C‐E, OLV lobectomy of 60, 90, and 120 min duration, respectively; F, normal subjects as baseline group. Preoperative, intraoperative and postoperative strict blood sampling protocol was followed. Malondialdehyde (MDA) plasma levels were measured. The recorded values were analyzed and statistically compared between groups and within each one. Results: Comparison of groups C‐E (OLV) to all other documented significant (P!0.001) increase of MDA levels during lung reexpansion and for the following 12 h. The magnitude of oxidative stress was related to OLV duration (group EODOC, all P!0.001). The removal of cancer-associated parenchyma led to MDA level decrease postoperatively (P!0.001) especially after pneumonectomy (A vs. B, P!0.001). Conclusions: (1) Lung reexpansion provoked severe oxidative stress. (2) The degree of the amount of generated oxygen free radicals was associated to the duration of OLV. (3) Patients with lung cancer had a higher production of oxygen free radicals than normal population. (4)Tumor resection removes a large oxidative burden from the organism. (5) Mechanical ventilation and surgical trauma are weak free radical generators. (6) Manipulated lung tissue is also a source of oxygen free radicals, not only intraoperatively but also for several hours later. q 2005 Elsevier B.V. All rights reserved.

Molecular dynamics simulation is used to model the microscopic structure (free volume in particular) and thermodynamic properties of a silicon-containing rubbery polymer that exhibits promising membrane properties for hydrocarbon separation. For this purpose, an accurate united atom force field is developed based on density functional theory calculations. Furthermore, molecular simulation is used to model the solubility and diffusivity of various n-alkanes in the polymer. Overall, the agreement between experimental data and simulation results is very satisfactory. (c) 2004 Elsevier B.V. All rights reserved. Fluid Phase Equilibria

Objective: The authors conducted a prospective analysis in order to investigate through lipid peroxidation metabolites the generation of oxygen free radicals after one-lung ventilation (OLV). Methods: From 2001 to 2003, 212 patients were prospectively studied for lung reexpansion/reperfusion injury. They were classified in six groups. Group A, non-OLV lobectomy group; B, OLV pneumonectonny group; C-E, OLV lobectomy of 60, 90, and 120 min duration, respectively; F, normal subjects as baseline group. Preoperative, intraoperative and postoperative strict blood sampling protocol was followed. Malondialdehyde (MDA) plasma levels were measured. The recorded values were analyzed and statistically compared between groups and within each one. Results: Comparison of groups C-E (OLV) to A other documented significant (P < 0.001) increase of MDA levels during lung reexpansion and for the following 12 h. The magnitude of oxidative stress was related to OLV duration (group E > D > C, all P < 0.001). The removal of cancer-associated parenchyma led to MDA level decrease postoperatively (P < 0.001) especially after pneumonectomy (A vs. B, P < 0.001). Conclusions: (1) Lung reexpansion provoked severe oxidative stress. (2) The degree of the amount of generated oxygen free radicals was associated to the duration of OLV. (3) Patients with lung cancer had a higher production of oxygen free radicals than normal population. (4)Tumor resection removes a large oxidative burden from the organism. (5) Mechanical ventilation and surgical trauma are weak free radical generators. (6) Manipulated lung tissue is also a source of oxygen free radicals, not only intraoperatively but also for several hours later. (c) 2005 Elsevier B.V. All rights reserved.