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Technical Difficulties (technical + difficulty)
Selected AbstractsLaparoscopic colorectal cancer surgery: Japanese experienceASIAN JOURNAL OF ENDOSCOPIC SURGERY, Issue 2 2009F Konishi Abstract In Japan, laparoscopic colectomy for cancer started in 1992. A national survey has revealed that, since that time, the number of cases that have undergone this procedure has steadily increased, and by 2007, there were over 9000 cases. This figure includes an increase in the percentage of more advanced cases, which has occurred due to technical improvements in lymph node dissection. A Japanese randomized controlled trial comparing laparoscopic to open surgery started in November 2004, with enrollment ending in April 2009 with 1050 cases. For this study, preoperative stage T3 and T4 cases were selected for inclusion, and D3 dissection was required. To assess the technical skill of surgeons, the Japan Society of Endoscopic Surgery established the Endoscopic Surgical Skill Qualification System to encourage high-level surgical techniques. Assessment is conducted by reviewing unedited videos. The success rate for colon and rectal surgeries has ranged between 37%,40%. The Endoscopic Surgical Skill Qualification System has contributed to the establishment of standard technical skills in laparoscopic surgery, the development of an educational system for laparoscopic surgeons, and a reduction in the number complications. Technical difficulties still exist in laparoscopic rectal cancer surgery, but with the technical progress in laparoscopic colorectal surgery, the number of laparoscopic rectal cancer surgeries has been gradually increasing in number. A multicentric phase II study on the feasibility and long-term outcome for stage I and II rectal cancer started in 2008. In this study, the short-term outcomes including anastomotic leakage rate and long-term survival, will be clarified. Combined with continuously improved technologies, training techniques and surgical standards, laparoscopic colorectal surgery is steadily progressing in Japan. [source] Rice straw management: the big wasteBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 2 2010Laura Domínguez-Escribá Abstract Rice is one of the major foods, with consumption per capita of 65 kg per year, accounting for 20% of global ingested calories. Rice production is expected to increase significantly in the near future in order to feed the rising human population. Today, paddy rice culture produces 660 million tons of rice, along with 800 million dry tons of agricultural residues, mainly straw. This biomass is managed predominantly through rice straw burning (RSB) and soil incorporation strategies. RSB leads to significant air pollution and has been banned in some regions, whereas stubble and straw incorporation into wet soil during land preparation is associated with enhanced methane emissions. Therefore, both strategies have important deleterious environmental effects and fail to take advantage of the huge energy potential of rice straw. Using rice straw as lignocellulosic biomass to produce bioethanol would appear to be a promising and ambitious goal to both manage this agricultural waste and to produce environmentally friendly biofuel. Technical difficulties, however, associated with the conversion of lignocellulose into simple, fermentable sugars, have hampered the massive development of rice-straw-derived bioethanol. Recent technical advances in straw pre-treatment, hydrolysis and fermentation may, however, overcome these limitations and facilitate a dramatic turnover in biofuels production in the near future. Copyright © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd [source] Copeptin: A Biomarker of Cardiovascular and Renal FunctionCONGESTIVE HEART FAILURE, Issue 2010Nils G. Morgenthaler MD Congest Heart Fail. 2010;16(4)(suppl 1):S37,S44. ©2010 Wiley Periodicals, Inc. Arginine vasopressin (AVP or antidiuretic hormone) is one of the key hormones in the human body responsible for a variety of cardiovascular and renal functions. It has so far escaped introduction into the routine clinical laboratory due to technical difficulties and preanalytical errors. Copeptin, the C-terminal part of the AVP precursor peptide, was found to be a stable and sensitive surrogate marker for AVP release. Copeptin behaves in a similar manner to mature AVP in the circulation, with respect to osmotic stimuli and hypotension. During the past years, copeptin measurement has been shown to be of interest in a variety of clinical indications, including cardiovascular diseases such as heart failure, myocardial infarction, and stroke. This review summarizes the recent progress on the diagnostic use of copeptin in cardiovascular and renal diseases and discusses the potential use of copeptin measurement in the context of therapeutic interventions with vasopressin receptor antagonists. [source] Seasonal variation in the migration strategies of the green lacewing Chrysoperla carnea species complexECOLOGICAL ENTOMOLOGY, Issue 4 2006JASON W. CHAPMAN Abstract 1. Insect migration strategies are generally poorly understood due to the propensity for high-altitude flight of many insect species, and the technical difficulties associated with observing these movements. While some progress has been made in the study of the migration of important insect pests, the migration strategies of insect natural enemies are often unknown. 2. Suction trapping, radar monitoring, and high-altitude aerial netting were used to characterise the seasonal migrations in the U.K. of an assemblage of aphid predators: three green lacewings in the Chrysoperla carnea species complex. 3. Chrysoperla carnea sens. str. was found to be very abundant at high altitudes during their summer migration, and some individuals were capable of migrating distances of , 300 km during their pre-ovipositional period. In contrast, high-altitude flights were absent in the autumn migration period, probably due to a behavioural adaptation that increases the probability that migrants will encounter their over-wintering sites. The other two species in the complex, C. lucasina and C. pallida, were much rarer, making up , 3% of the total airborne populations throughout the study period. 4. The summer migration of C. carnea sens. str. was not directly temporally associated with the summer migration of its cereal aphid prey, but lagged behind by about 4 weeks. There was also no evidence of spatial association between aphid and lacewing populations. 5. The results show that to understand the population ecology of highly mobile insect species, it is necessary to characterise fully all aspects of their migration behaviour, including the role of high-altitude flights. [source] Pharmacokinetic predictions in children by using the physiologically based pharmacokinetic modellingFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 6 2008F. Bouzom Abstract Nowadays, 50,90% of drugs used in children have never been actually studied in this population. Consequently, either our children are often exposed to the risk of adverse drug events or to lack of efficacy, or they are unable to benefit from a number of therapeutic advances offered to adults, as no clinical study has been properly performed in children. Actually the main methods used to calculate the dose for a child are based on allometric methods taking into account different categories of age, the body weight and/or the body surface area. Unfortunately, these calculation methods consider the children as small adults, which is not the case. Physiologically based pharmacokinetics is one way to integrate the physiological changes occurring in the childhood and to anticipate their impact on the pharmacokinetic processes: absorption, distribution, metabolism and excretion/elimination. From different examples, the application of this modelling approach is discussed as a possible and valuable method to minimize the ethical and technical difficulties of conducting research in children. [source] The impacts of non-native species on UK biodiversity and the effectiveness of controlJOURNAL OF APPLIED ECOLOGY, Issue 5 2000Sarah J. Manchester 1.,The introduction of non-native species continues to cause ecological concern globally, but there have been no published reviews of their effects in the UK. Impacts in the UK are therefore reviewed, along with current legislation and guidelines relating to the introduction and control of such species. 2.,A large number of non-native species have been introduced to the UK, both deliberately and accidentally, but only a small number of introduced non-native species have established and caused detrimental ecological impacts. However, general declines in UK biodiversity, and the potential effects of future climate change, may increase the susceptibility of ecosystems to invasions. 3.,Detrimental impacts of non-native species on native biota have occurred through competition, predation, herbivory, habitat alteration, disease and genetic effects (i.e. hybridization). There are potential effects on genetic biodiversity as well as species biodiversity. 4.,Several high profile examples highlight the technical difficulties, and financial implications, of removing an introduced species once it is established. Few UK control or eradication programmes have been successful. 5.,Control might be more feasible if ,problem' species could be identified at an earlier stage of establishment. However, the poor success of attempts to characterize invasive species and predict which will have negative impacts highlight the individual and unpredictable nature of invasions. The difficulties of making general predictions suggest that every proposed species introduction should be subject to rigorous ecological characterization and risk assessment prior to introduction. 6.,The plethora of UK legislation and guidelines developed to reduce impacts of non-native species only go part of the way towards ameliorating impact. Many species already established in the wild might cause future problems. Illegal releases and escapes of non-native species may augment feral populations or establish new colonies. While regulation of imports and releases is important, further enforcement of existing legislation and action against unlicensed releases is necessary. [source] Initial Clinical Experience with Cardiac Resynchronization Therapy Utilizing a Magnetic Navigation SystemJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2007PETER GALLAGHER M.D. Introduction: The placement of left ventricular (LV) leads during cardiac resynchronization therapy (CRT) involves many technical difficulties. These difficulties increase procedural times and decrease procedural success rates. Methods and Results: A total of 50 patients with severe cardiomyopathy (mean LV ejection fraction was 21 ± 6%) and a wide QRS underwent CRT implantation. Magnetic navigation (Stereotaxis, Inc.) was used to position a magnet-tipped 0.014, guidewire (CronusÔ guidewire) within the coronary sinus (CS) vasculature. LV leads were placed in a lateral CS branch, either using a standard CS delivery sheath or using a "bare-wire" approach without a CS delivery sheath. The mean total procedure time was 98.1 ± 29.1 minutes with a mean fluoroscopy time of 22.7 ± 15.1 minutes. The mean LV lead positioning time was 10.4 ± 7.6 minutes. The use of a delivery sheath was associated with longer procedure times 98 ± 32 minutes vs 80 ± 18 minutes (P = 0.029), fluoroscopy times 23 ± 15 minutes vs 13 ± 4 minutes (P = 0.0007) and LV lead positioning times 10 ± 6 minutes vs 4 ± 2 minutes (P = 0.015) when compared to a "bare-wire" approach. When compared with 52 nonmagnetic-assisted control CRT cases, magnetic navigation reduced total LV lead positioning times (10.4 ± 7.6 minutes vs 18.6 ± 18.9 minutes; P = 0.005). If more than one CS branch vessel was tested, magnetic navigation was associated with significantly shorter times for LV lead placement (16.2 ± 7.7 minutes vs 36.4 ± 23.4 minutes; P = 0.004). Conclusions: Magnetic navigation is a safe, feasible, and efficient tool for lateral LV lead placement during CRT. Magnetic navigation during CRT allows for control of the tip direction of the CronusÔ 0.014, guidewire using either a standard CS delivery sheath or "bare-wire" approach. Although there are some important limitations to the 0.014, CronusÔ magnetic navigation can decrease LV lead placement times compared with nonmagnetic-assisted control CRT cases, particularly if multiple CS branches are to be tested. [source] Evaluation of preoperative sonography in acute cholecystitis to predict technical difficulties during laparoscopic cholecystectomyJOURNAL OF CLINICAL ULTRASOUND, Issue 3 2004Kyung Soo Cho MD Abstract Purpose The aim of this study was to evaluate the role of preoperative sonography in predicting technical difficulties during laparoscopic cholecystectomy in patients with acute cholecystitis. Methods Sonographic assessment of 14 parameters was performed in 55 patients during a 9-month period: volume of gallbladder (GB), thickness of GB wall, pattern of GB wall thickening, size of largest gallstone, gallstone mobility, adhesion of GB to its bed, fat plane between GB and hepatoduodenal ligament, free fluid in GB fossa, common bile duct (CBD) dilatation, CBD stone(s), color and power Doppler signals in GB wall, and increased color and power Doppler signals in adjacent liver. Each of the 5 operative steps of laparoscopic cholecystectomy was scored as being difficult (1) or not (0). The scores for each step were added to obtain the overall difficulty score (0,5). We evaluated prospectively whether there were significant associations among the preoperative sonographic findings and the overall difficulty score, scores for each of the 5 operative steps, and operation time. Results The overall difficulty score was significantly associated with a GB volume of 50 cm3 or more, GB wall thickness of 3 mm or more, and presence of color Doppler signals in the GB wall. Increased GB volume also made dissection of adhesions from the GB and dissection of Calot's triangle more difficult. Extraction of the GB from the abdomen was more difficult with a thickened GB wall or adhesion of the GB to its bed. The presence of a CBD stone, dilatation of the CBD (, 8 mm), color Doppler signals in the GB wall, and increased power Doppler signals in the adjacent liver were significantly associated with increased operation time. Conclusions Based on our experience, preoperative determination of GB volume, GB wall thickness, and presence of color Doppler signals in the GB wall in patients with acute cholecystitis helps predict technical difficulties during laparoscopic cholecystectomy. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:115,122, 2004 [source] Learning gains associated with annotation and communication software designed for large undergraduate classesJOURNAL OF COMPUTER ASSISTED LEARNING, Issue 1 2007T. L. Wentling Abstract The purpose of this study was to explore the potential of annotation and communication software (eFuzion) developed for the improvement of students' learning and to determine the effectiveness of the software. eFuzion is designed to be useful in a significantly large classroom by allowing instructors and teaching assistants to provide immediate responses to students' questions and to provide a broader array of options for the lucid presentation of complex concepts. To determine the effectiveness of the software, two groups that took the same course were compared in terms of their learning scores, one group having used the software, the other having not used it. In the three measures of learning, the students who used the software showed significantly higher learning scores than students who did not use it. In addition, students indicated that they felt closer to the instructor and that their understanding of the lecture material was increased by using the software. The results imply that the software has great potential for improving students' learning when it is appropriately used and free of technical difficulties. [source] Chlamydia pneumoniae in atherosclerosisJOURNAL OF INTERNAL MEDICINE, Issue 3 2000P. Saikku Abstract. Saikku P (National Public Health Institute, Oulu, Finland). Chlamydia pneumoniae in atherosclerosis (Minisymposium). J Intern Med 2000; 247: 391,396. Chlamydia pneumoniae is currently the infectious agent most often associated with the inflammation found in atherosclerosis. The seroepidemiological association and the actual presence of pathogen in lesions has been confirmed in numerous studies, in which technical difficulties seem to be the only limitation. Besides animal experiments and intervention trials, we need information of possible pathogenic mechanisms. Recently, several studies have suggested mechanisms by which C. pneumoniae infection could participate in the development of atherosclerosis. [source] Transesophageal Echocardiography and Intracardiac Echocardiography Differently Predict Potential Technical Challenges or Failures of Interatrial Shunts Catheter-Based ClosureJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 1 2007GIANLUCA RIGATELI M.D. We sought to prospectively assess the role of transesophageal (TEE) and intracardiac echocardiography (ICE) in detecting potential technical difficulties or failures in patients submitted to interatrial shunts percutaneous closure. We prospectively enrolled 46 consecutive patients (mean age 35±28, 8 years, 30 female) referred to our center for catheter-based closure of interatrial shunts. All patients were screened with TEE before the intervention. Patients who met the inclusion criteria underwent ICE study before the closure attempt (40 patients). TEE detected potential technical difficulties in 22.5% (9/40) patients, whereas ICE detected technical difficulties in 32.5% (13/40 patients). In patients with positive TEE/ICE the procedural success (92.4% versus 100% and, P = ns) and follow-up failure rate (7.7% versus 0%, P = ns) were similar to patients with negative TEE/ICE, whereas the fluoroscopy time (7 ± 1.2 versus 5 ± 0.7 minutes, P < 0.03), the procedural time (41 ± 4.1 versus 30 ± 8.2 minutes, P ± 0.03), and technical difficulties rate (23.1% versus 0%, P = 0.013) were higher. Differences between ICE and TEE in the evaluation of rims, measurement of ASD or fossa ovalis, and detection of venous valve and embryonic septal membrane remnants impacted on technical challenges and on procedural and flouroscopy times but did not influence the success rate and follow-up failure rate. [source] An Unusual Case of an Accessory Coronary Artery to Pulmonary Artery Fistula:JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 1 2004Successful Closure with Transcatheter Coil Embolization Coronary artery fistulae (CAF) are rare congenital anomalies. Surgical ligation is the standard treatment for symptomatic CAF, but is associated with higher morbidity. In a select group of patients, transcatheter coil embolization (TCE) is a reasonable alternative to standard surgical treatment. In this article, we present a unique (not previously reported) case of a tortuous accessory anomalous right coronary artery to pulmonary artery fistula with coronary steal phenomenon. TCE of highly tortuous fistulae can be technically difficult and are usually referred for surgery. In this case report we describe how utilization of adult coronary interventional wires and balloon catheters may help overcome some of the technical difficulties encountered with catheter-based closure of CAF. (J Interven Cardiol 2004;17:59,63) [source] Lack of protein expression of the simian virus 40 large T antigen in human lymphomas,,JOURNAL OF MEDICAL VIROLOGY, Issue 6 2008Philip Went Abstract Several studies have detected Simian virus 40 (SV40) deoxyribonucleic acid sequences in human tumor tissues, including lymphomas, mainly by the polymerase chain reaction, but these data were not confirmed by subsequent investigations. Regional differences in the distribution of the SV40 and/or technical difficulties have been taken into account to explain these divergent results, but because only a few such studies dealt with the expression of SV40 proteins in tumor tissues, we investigated the expression of the SV40 large T antigen in human lymphomas by immunohistochemistry. Tissue microarrays containing Non-Hodgkin's-lymphomas and Hodgkin's-lymphomas were constructed utilizing archival samples encompassing the years 1974,2001 from Italian, Swiss and Austrian patients. Expression of the SV40 large T antigen was analysed by highly specific and sensitive immunohistochemistry using a mouse monoclonal antibody. Protein expression of the large T antigen was not detected in 655 Non-Hodgkin's-lymphomas or in 337 Hodgkin's- lymphomas. The results suggest the absence of an association between SV40 large T antigen and human lymphomas. J. Med. Virol. 80:1112,1115, 2008. © 2008 Wiley-Liss, Inc. [source] Reliability of a new ultrasonic cardiac output monitor in recipients of living donor liver transplantation,,§¶LIVER TRANSPLANTATION, Issue 7 2008Bai-Chuan Su The ultrasonic cardiac output monitor (USCOM) is a new Doppler device for noninvasive hemodynamic monitoring. The aim of this prospective nonrandomized study was to test the feasibility, perioperative reliability, and clinical applicability of using USCOM as an alternative to pulmonary artery catheterization in recipients of living donor liver transplantation. Thirteen patients scheduled to receive living donor liver transplants were initially recruited. Three were subsequently excluded prior to the commencement of surgery because of technical difficulties in obtaining diagnostic-quality images with USCOM. Ten patients proceeded to be studied. Cardiac output measurements by thermodilution and USCOM were compared at 30-minute intervals throughout the procedure and at 10 specific procedural reference points during the surgery when hemodynamic changes were most likely to be observed. The data were analyzed with Lin's concordance coefficient and Bland-Altman analysis. Two hundred ninety paired cardiac output values were obtained from the 10 patients. The concordance between both methods was excellent in 8 patients and satisfactory in 2. Bland-Altman analysis of all data produced a mean bias of , 0.02 L/minute for USCOM, and the 95% limits of agreement were ,1.06 to +1.10 L/minute. Further analysis of the 10 reference time points showed minimal bias and high levels of agreement between the methods. We conclude that USCOM provides an accurate and noninvasive method for cardiac output measurement during liver transplantation. It may therefore represent an alternative to pulmonary artery catheter placement with consequent reduction in patient's risk and morbidity associated with catheterization. Liver Transpl 14:1029,1037, 2008. © 2008 AASLD. [source] Teaching consultation skills: a survey of general practice trainersMEDICAL EDUCATION, Issue 3 2001Alison Evans Background Consultation skills are vitally important in general practice (GP), and now form part of the summative assessment of GP registrars in the UK. GP trainers need to be skilled in teaching consultation skills, and also need the time and resources to ensure that their registrars are competent in consultation skills. Aims To describe the teaching methods used by GP trainers in one deanery, the frequency of teaching of consultation skills, the problems encountered and the training that GP trainers have themselves received both in consultation skills and how to teach them. Method Postal questionnaire survey of all the 164 trainers in the Yorkshire Deanery. Results Replies were received from 129 trainers (response rate 79%) of which 123 could be analysed. Of these trainers, 45 (37%) trainers taught consultation skills fewer than five times a year, 45 (37%) five to 10 times, and 14 (11%) more than 10 times a year. A total of 24 trainers reported problems with teaching consultation skills, most commonly lack of time, technical difficulties, and unreceptive registrars, and 97 (79%) trainers had had some postgraduate training in consultation skills with 112 (91%) reporting some form of teacher training. Conclusion There is considerable variation in the reported frequency of teaching consultation skills, the models used, and the preparation of trainers for teaching, despite a systematic approach to teacher training in the Yorkshire Deanery. [source] Microsurgical tracheotomy: A pediatric model in growing ratsMICROSURGERY, Issue 5 2003Mônica Cecília Bochetti Manna M.D. Previous studies described controversial opinions about pediatric tracheotomy concerning type of tracheal incision and long-term results, which remain as important research subjects. Experimental studies on rat tracheas are scarce, probably because of technical difficulties related to the structures' small dimensions. As many rat organ and system operative procedures were studied successfully by using microsurgical techniques, we decided to develop a pediatric tracheotomy model in growing rats which would permit long-term studies. Forty-four Wistar EPM-1 growing rats weighing 86 g and aged 35 days were divided into three groups: submitted to longitudinal, transverse, and segment excision of the trachea. Under sterile technique and intramuscular anesthesia (ketamine/xylazine), the trachea was exposed and incised, according to group, and a hand-made endotracheal cannula was inserted into the organ. This cannula was assembled using a segment of 1.5-cm-long 3 French silicone catheter passed through hexagonal-shaped silicone screen. The tracheal cannula was removed after 7 days, when we evaluated body weight, secretions, and dehiscence. In conclusion, this microsurgical tracheotomy model in growing rats is feasible, allowing studies on long-term repercussions of pediatric tracheotomy. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:530,534 2003 [source] Ambulatory foot temperature measurement: A new technique in polyneuropathy evaluationMUSCLE AND NERVE, Issue 6 2003Peter B. Kang MD Abstract Complaints of abnormal foot temperature are common among patients with polyneuropathy. However, there is no published method of ambulatory foot temperature measurement to identify possible thermoregulatory disturbances in these patients. We configured a digital electronic thermometer and thermocouple to measure and record distal foot and ambient temperatures simultaneously every minute for 24 to 48 h. Sixteen patients with polyneuropathy and 5 normal subjects were studied; 12 patients with polyneuropathy and 4 normal subjects had at least 24 h of successful recording. The data obtained from these patients were consistent and easily summarized by standard statistical methods. In the others, technical difficulties produced nonphysiological readings. In the patients with polyneuropathy, changes in foot temperature mirrored ambient temperature fluctuations more closely than in normal subjects. This technique shows promise in studying temperature regulation in the feet and may provide new insights into neuropathy-associated pain and the pathogenesis of polyneuropathy. Muscle Nerve 27: 737,742, 2003 [source] Plasticity and ambiguity of the electrophysiological phenotypes of enteric neuronsNEUROGASTROENTEROLOGY & MOTILITY, Issue 9 2009K. Nurgali Abstract, Advances in knowledge of enteric neurons electrophysiological characteristics have led to the realisation that the properties of the neurons are dependent on the state of the intestine, the region, the method of recording and the species. Thus, under different experimental conditions, electrophysiological studies cannot provide a reliable signature that identifies the functional type of neuron. In the normal guinea-pig small intestine, taken as a model tissue, neurons can be separated into two electrophysiological groups, S and AH neurons. Combined morphological and physiological studies place several classes of motor and interneurons in the S group, and intrinsic primary afferent neurons in the AH group. There is some evidence for subgroups of S neurons, in which electrophysiological differences are correlated with functional subtypes, but these subgroups have been incompletely investigated. Morphologically characterized Dogiel type II (DII) neurons are recognisable in many species, from mouse to human, but their electrophysiological characteristics are only partly conserved across species or cannot be satisfactorily defined due to technical difficulties. There is a strong need for a comprehensive analysis of channels and currents of S/Dogiel type I neuron subtypes, similar to the comprehensive analysis of AH/DII neurons in the guinea-pig, and similar studies need to be conducted in human and other species. The purpose of this review is to highlight that criteria used for electrophysiological definition of enteric neurons might not be sufficient to distinguish between functional classes of neurons, due to intrinsic properties of neuronal subpopulations, plasticity in pathological conditions and differences in recording techniques. [source] Successful adult-to-child renal transplantation utilizing the ovarian vein in children with inferior vena cava/iliac vein thrombosisPEDIATRIC TRANSPLANTATION, Issue 6 2010Ran Tao Tao R, Shapiro R. Successful adult-to-child renal transplantation utilizing the ovarian vein in children with inferior vena cava/iliac vein thrombosis. Pediatr Transplantation 2010: 14:E70,E74. © 2009 John Wiley & Sons A/S. Abstract:, IVC/iliac vein thrombosis has previously been considered to be a contraindication to renal transplantation because of the technical difficulties and the increased risk of graft thrombosis. We report two successful cases of adult-to-child kidney transplantation in which we anastomosed the graft renal vein to the recipient ovarian vein in the presence of IVC and/or iliac vein thrombosis, with no short or long term vascular complications. Our experience, which adds to the successful reports from several other centers, suggests that the inability to use the iliocaval axis should no longer be considered a contraindication to pediatric renal transplantation. [source] On the 13C/12C isotopic signal of day and night respiration at the mesocosm levelPLANT CELL & ENVIRONMENT, Issue 6 2010GUILLAUME TCHERKEZ ABSTRACT While there is currently intense effort to examine the 13C signal of CO2 evolved in the dark, less is known on the isotope composition of day-respired CO2. This lack of knowledge stems from technical difficulties to measure the pure respiratory isotopic signal: day respiration is mixed up with photorespiration, and there is no obvious way to separate photosynthetic fractionation (pure ci/ca effect) from respiratory effect (production of CO2 with a different ,13C value from that of net-fixed CO2) at the ecosystem level. Here, we took advantage of new simple equations, and applied them to sunflower canopies grown under low and high [CO2]. We show that whole mesocosm-respired CO2 is slightly 13C depleted in the light at the mesocosm level (by 0.2,0.8,), while it is slightly 13C enriched in darkness (by 1.5,3.2,). The turnover of the respiratory carbon pool after labelling appears similar in the light and in the dark, and accordingly, a hierarchical clustering analysis shows a close correlation between the 13C abundance in day- and night-evolved CO2. We conclude that the carbon source for respiration is similar in the dark and in the light, but the metabolic pathways associated with CO2 production may change, thereby explaining the different 12C/13C respiratory fractionations in the light and in the dark. [source] Shotgun proteomic analysis of human-induced sputumPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 15 2006Ben Nicholas Dr. Abstract Induced sputum is a readily accessible biological fluid whose composition may alter as a consequence of disease. To date, however, the proteins that routinely populate this biofluid are largely unknown, in part due to the technical difficulties in processing such mucin-rich samples. To provide a catalogue of sputum proteins, we have surveyed the proteome of human-induced sputum (sputome). A combination of 2-D gel analysis and GeLC-MS/MS allowed a total of 191 human proteins to be confidently assigned. In addition to the expected components, several hitherto unreported proteins were found to be present, including three members of the annexin family, kallikreins 1 and 11, and peroxiredoxins 1, 2 and 5. Other sets of proteins identified included four proteins previously annotated as hypothetical or conserved hypothetical. Taken together, these data represent the first extensive survey of the proteome of induced sputum and provide a platform for future identification of biomarkers of lung disease. [source] Isotope ratio mass spectrometry coupled to liquid and gas chromatography for wine ethanol characterizationRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 20 2008Ana I. Cabañero Two new procedures for wine ethanol 13C/12C isotope ratio determination, using high-performance liquid chromatography and gas chromatography isotope ratio mass spectrometry (HPLC/IRMS and GC/IRMS), have been developed to improve isotopic methods dedicated to the study of wine authenticity. Parameters influencing separation of ethanol from wine matrix such as column, temperature, mobile phase, flow rates and injection mode were investigated. Twenty-three wine samples from various origins were analyzed for validation of the procedures. The analytical precision was better than 0.15,, and no significant isotopic fractionation was observed employing both separative techniques coupled to IRMS. No significant differences and a very strong correlation (r,=,0.99) were observed between the 13C/12C ratios obtained by the official method (elemental analyzer/isotope ratio mass spectrometry) and the proposed new methodology. The potential advantages of the developed methods over the traditional one are speed (reducing time required from hours to minutes) and simplicity. In addition, these are the first isotopic methods that allow 13C/12C determination directly from a liquid sample with no previous ethanol isolation, overcoming technical difficulties associated with sample treatment. Copyright © 2008 John Wiley & Sons, Ltd. [source] A simple and economical method for the manual construction of frozen tissue arraysAPMIS, Issue 10 2010SHU-CHUAN TSAO Tsao S-C, Wu C-C, Wen C-H, Huang Y-C, Chai C-Y. A simple and economical method for the manual construction of frozen tissue arrays. APMIS 2010; 118: 739,43. Tissue microarray has been developed to enable multiple cores of tissue in one or more new paraffin blocks. Currently, almost all tissue microarrays are made by coring cylindrical tissues from formalin-fixed and paraffin-embedded tissues. The disadvantages of formalin-fixed and paraffin-embedded tissues include the poor preservation of antigenicity of certain proteins and mRNA degradation induced by the fixation and embedding process. However, frozen tissue array construction presents technical difficulties, and tissue array devices are expensive, particularly for small- and medium-sized laboratories. We describe a simple manual method for producing well-aligned tissue arrays by a capsule freeze method that allows us to successfully perform hematoxylin,eosin and immunohistochemical stain. All 120 tissue samples were collected and constructed into blocks by this capsule freeze method. The capsules were not affected during the sectioning process, and the capsule material always disappeared during the aqueous steps of the stain processing. The frozen tissue arrays were smoothly sectioned without the use of a tape transfer system and immunohistochemical study was performed with satisfactory results. This alternative method can be applied in any laboratory, and is both simple and economical. [source] Live feeds for early stages of fish rearingAQUACULTURE RESEARCH, Issue 5 2010Luís E C Conceição Abstract Despite the recent progress in the production of inert diets for fish larvae, feeding of most species of interest for aquaculture still relies on live feeds during the early life stages. Independently of their nutritional value, live feeds are easily detected and captured, due to their swimming movements in the water column, and highly digestible, given their lower nutrient concentration (water content>80%). The present paper reviews the main types of live feeds used in aquaculture, their advantages and pitfalls, with a special emphasis on their nutritional value and the extent to which this can be manipulated. The most commonly used live feeds in aquaculture are rotifers (Brachionus sp.) and brine shrimp (Artemia sp.), due to the existence of standardized cost-effective protocols for their mass production. However, both rotifers and Artemia have nutritional deficiencies for marine species, particularly in essential n-3 highly unsaturated fatty acids (HUFA, e.g., docosahexaenoic acid and eicosapentaenoic acid). Enrichment of these live feeds with HUFA-rich lipid emulsions may lead to an excess dietary lipid and sub-optimal dietary protein content for fish larvae. In addition, rotifers and Artemia are likely to have sub-optimal dietary levels of some amino acids, vitamins and minerals, at least for some species. Several species of microalgae are also used in larviculture. These are used as feed for other live feeds, but mostly in the ,green water' technique in fish larval rearing, with putative beneficial effects on feeding behaviour, digestive function, nutritional value, water quality and microflora. Copepods and other natural zooplankton organisms have also been used as live feeds, normally with considerably better results in terms of larval survival rates, growth and quality, when compared with rotifers and Artemia. Nonetheless, technical difficulties in mass-producing these organisms are still a constraint to their routine use. Improvements in inert microdiets will likely lead to a progressive substitution of live feeds. However, complete substitution is probably years away for most species, at least for the first days of feeding. [source] Development of a New Tissue-Engineered Sheet for Reconstruction of the StomachARTIFICIAL ORGANS, Issue 10 2009Masato Araki Abstract We have developed tissue-engineered digestive tracts composed of collagen scaffold and an inner silicon sheet and successfully used it to repair defects in parts of the esophagus, stomach, and small intestine. However, some improvements were demanded for clinical usage because the silicon sheet presented technical difficulties for suturing and endoscopic removal. New tissue-engineered sheet (New-sheet) was composed of a single-piece and reinforced collagen scaffold with biodegradable copolymer. One beagle dog was used to evaluate whether New-sheet could withstand suturing in comparison with native digestive tracts using a tensile tester. Seven beagle dogs had a 5-cm circular defect created in the stomach. New-sheet soaked with autologous peripheral blood or bone marrow aspirate was sutured to the gastric wall. Endoscopic, histological, and immunohistochemical assessment was performed to evaluate regeneration of the stomach up to 16 weeks. Tensile strength testing showed that the mucosal side of New-sheet had strength almost equivalent to the mucosa of the esophagus (P = 0.61). Endoscopically, regeneration of the mucosa started from the circumference after 4 weeks, but a small linear ulcer was still evident at 16 weeks. The regenerated stomach shrank by 60,80% of its original size and histologically showed villous mucosa and underlying dense connective tissue. Immunohistochemically, the regenerated area expressed ,-smooth-muscle actin but was negative for basic calponin, irrespective of the source of soaked blood. New-sheet shows sufficient strength for suturing, no dehiscence, and better biocompatibility for clinical use, although further examination will be necessary to create a functional digestive tract. [source] Effective Bilirubin Reduction by Single-Pass Albumin Dialysis in Liver FailureARTIFICIAL ORGANS, Issue 8 2009Ussanee Boonsrirat Abstract Albumin dialysis is widely accepted as a liver-support technique for patients with liver failure. The Molecular Adsorbent Recirculating System, the widely accepted albumin dialysis technique, has limited use in developing countries because of its technical difficulties and high cost. Therefore, we assessed the efficacy of the more practical modality, the single-pass albumin dialysis (SPAD), in terms of bilirubin reduction, as a marker of albumin-bound toxins removal, as well as the patient outcomes. Twelve acute or acute-on-chronic patients with liver failure who had hyperbilirubinemia (total bilirubin > 20 mg/dL) were treated with SPAD by using 2% human serum albumin dialysate for 6 h. SPAD treatment significantly improved the levels of total bilirubin, conjugated bilirubin, urea, and creatinine (P < 0.001 for all parameters). The reduction ratios of these four parameters were 22.9 ± 3.8%, 20.9 ± 5%, 19.0 ± 4.1%, and 27.7 ± 3.2%, respectively. No significant difference was observed between serum ammonia before and after treatment. No significant changes in mean arterial pressures were noted during the maneuver, representing cardiovascular tolerability. No treatment-related complications were found. The 15-day in-hospital survival was 16.7%. However, a subgroup of the patients who had moderate severity showed 100% 15-day-survival rate (2 of 2 patients). In conclusion, SPAD is salutarily effective in reducing bilirubin in patients with liver failure. The procedure is safe and simply set up. [source] The Troughton & Simms transit circle of Coimbra Astronomical Observatory from the 1850s: An example of the dissemination of technological developmentsASTRONOMISCHE NACHRICHTEN, Issue 6 2009V. Bonifácio Abstract Yesterday, as today, technological developments led by large and expensive instrumental projects are later on disseminated to smaller and more affordable devices. In 1847, Airy requested a new transit circle for the Greenwich Observatory. When the first observation was performed, on 4 January 1851, Airy's Greenwich Transit Circle (ATC) was the largest instrument of its class in the world. The construction of the ATC implied solving several technical difficulties, for example, the maintenance of the instrument rigidity and the illumination of the graduated circle and telescope field of view. After the ATC completion Troughton & Simms stand at the 1851 Great London Exhibition included two small transit instruments which were praised for their telescope field of view/eyepiece wires illumination. One of which, was based upon the design implemented beforehand on the ATC. In this paper we will discuss the field and eyepiece wire illumination innovations introduced on the ATC and the Simms transit instruments exhibited in 1851. We will also describe the small Troughton & Simms transit circle currently belonging to Coimbra Astronomical Observatory collection that is, we believe, one of the earliest implementation of this ATC lead development (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Manufacturing antibodies in the plant cellBIOTECHNOLOGY JOURNAL, Issue 12 2009Diego Orzáez Dr. Abstract Plants have long been considered advantageous platforms for large-scale production of antibodies due to their low cost, scalability, and the low chances of pathogen contamination. Much effort has therefore been devoted to efficiently producing mAbs (from nanobodies to secretory antibodies) in plant cells. Several technical difficulties have been encountered and are being overcome. Improvements in production levels have been achieved by manipulation of gene expression and, more efficiently, of cell targeting and protein folding and assembly. Differences in mAb glycosylation patterns between animal and plant cells are being successfully addressed by the elimination and introduction of the appropriate enzyme activities in plant cells. Another relevant battlefield is the dichotomy between production capacity and speed. Classically, stably transformed plant lines have been proposed for large scale mAb production, whereas the use of transient expression systems has always provided production speed at the cost of scalability. However, recent advances in transient expression techniques have brought impressive yield improvements, turning speed and scalability into highly compatible assets. In the era of personalized medicines, the combination of yield and speed, and the advances in glyco-engineering have made the plant cell a serious contender in the field of recombinant antibody production. [source] Historical review of breast lymphatic studiesCLINICAL ANATOMY, Issue 5 2009Hiroo Suami Abstract The gross anatomy of the lymphatic system is one of the least studied areas of anatomy, primarily because of the technical difficulties encountered in demonstrating this almost invisible yet vast system. Similarly, there have been very few studies of the gross lymphatic anatomy of the adult human breast. Previous studies used young pregnant female cadavers. When mercury was injected into the lactiferous ducts or breast lymphatic channels, these cadavers enabled early anatomists to see the breast lymphatics. Both Cruikshank (1786) and Cooper (1840) located the axillary lymph pathway as well as accessory pathways directly from the breast. Sappey (1874) concluded that all lymphatics arising from the breast drained into the axilla via the subareolar plexus. Current descriptions of the breast lymphatics may be traced back to the diagram made by Poirier and Cuneo (1902). However, it is apparent that this diagram is a composite of adult breast studies by Sappey, their fetal studies and even clinical feedback. This study provides an historical perspective of the methods that have been previously used to study the lymphatics of the breast and introduces an update on current investigative approaches. Clin. Anat. 22:531,536, 2009. © 2009 Wiley-Liss, Inc. [source] Universality at the edge of the spectrum for unitary, orthogonal, and symplectic ensembles of random matricesCOMMUNICATIONS ON PURE & APPLIED MATHEMATICS, Issue 6 2007Percy Deift We prove universality at the edge of the spectrum for unitary (, = 2), orthogonal (, = 1), and symplectic (, = 4) ensembles of random matrices in the scaling limit for a class of weights w(x) = e,V(x) where V is a polynomial, V(x) = ,2mx2m + · · ·, ,2m > 0. The precise statement of our results is given in Theorem 1.1 and Corollaries 1.2 and 1.4 below. For the same class of weights, a proof of universality in the bulk of the spectrum is given in [12] for the unitary ensembles and in [9] for the orthogonal and symplectic ensembles. Our starting point in the unitary case is [12], and for the orthogonal and symplectic cases we rely on our recent work [9], which in turn depends on the earlier work of Widom [46] and Tracy and Widom [42]. As in [9], the uniform Plancherel-Rotach-type asymptotics for the orthogonal polynomials found in [12] plays a central role. The formulae in [46] express the correlation kernels for , = 1, 4 as a sum of a Christoffel-Darboux (CD) term, as in the case , = 2, together with a correction term. In the bulk scaling limit [9], the correction term is of lower order and does not contribute to the limiting form of the correlation kernel. By contrast, in the edge scaling limit considered here, the CD term and the correction term contribute to the same order: this leads to additional technical difficulties over and above [49]. © 2006 Wiley Periodicals, Inc. [source] | ||||||||||||||||||||||||||||||||||