Abdominal decompression for abdominal compartment syndrome in critically ill patients: a retrospective study

Background. The abdominal compartment syndrome (ACS) refers to organ dysfunction that may occur as a result of increased intra-abdominal pressure (IAP). Successful management may require abdominal decompression and temporary abdominal closure (TAC). The aim of this study was to analyze the characteristics of patients requiring abdominal decompression, to describe the methods used for TAC, and to study the outcome of these patients. Methods. A series of critically ill patients who required abdominal decompression for ACS between January 2000 and March 2007 were reviewed retrospectively. Age, gender, severity of organ dysfunction before decompression and the cause of ACS as well as the type of abdominal closure system and length of ICU-stay were recorded. Definitive abdominal closure and in-hospital mortality were the main outcome parameters. Results. Eighteen patients with primary ACS and 6 with secondary ACS required decompressive laparotomy. Patients ages ranged from 18 to 89 years (mean 50.7). The median preoperative IAP was 26mmHg, and IAP decreased to 13mmHg after decompressive laparotomy. Organ function, as quantified by the SOFA scoring system, improved significantly after the intervention. Eight patients had immediate primary fascial closure after the decompressive procedure and 16 patients required TAC. The majority of the survivors underwent planned ventral hernia repair at a later stage. The mean length of stay in the ICU was 23 (+/- 16) days. Overall, fifteen patients survived (63%). Conclusions. Decompressive laparotomy was effective in reducing IAP and was associated with an improvement in organ function. In most of the patients, the abdomen could not be closed after decompression, and fascial repair was delayed

Improving the translation environment for professional translators

When using computer-aided translation systems in a typical, professional translation workflow, there are several stages at which there is room for improvement. The SCATE (Smart Computer-Aided Translation Environment) project investigated several of these aspects, both from a human-computer interaction point of view, as well as from a purely technological side. This paper describes the SCATE research with respect to improved fuzzy matching, parallel treebanks, the integration of translation memories with machine translation, quality estimation, terminology extraction from comparable texts, the use of speech recognition in the translation process, and human computer interaction and interface design for the professional translation environment. For each of these topics, we describe the experiments we performed and the conclusions drawn, providing an overview of the highlights of the entire SCATE project

Microarray-Based Transcriptomic Analysis of Differences between Long-Term Gregarious and Solitarious Desert Locusts

Desert locusts (Schistocerca gregaria) show an extreme form of phenotypic plasticity and can transform between a cryptic solitarious phase and a swarming gregarious phase. The two phases differ extensively in behavior, morphology and physiology but very little is known about the molecular basis of these differences. We used our recently generated Expressed Sequence Tag (EST) database derived from S. gregaria central nervous system (CNS) to design oligonucleotide microarrays and compare the expression of thousands of genes in the CNS of long-term gregarious and solitarious adult desert locusts. This identified 214 differentially expressed genes, of which 40% have been annotated to date. These include genes encoding proteins that are associated with CNS development and modeling, sensory perception, stress response and resistance, and fundamental cellular processes. Our microarray analysis has identified genes whose altered expression may enable locusts of either phase to deal with the different challenges they face. Genes for heat shock proteins and proteins which confer protection from infection were upregulated in gregarious locusts, which may allow them to respond to acute physiological challenges. By contrast the longer-lived solitarious locusts appear to be more strongly protected from the slowly accumulating effects of ageing by an upregulation of genes related to anti-oxidant systems, detoxification and anabolic renewal. Gregarious locusts also had a greater abundance of transcripts for proteins involved in sensory processing and in nervous system development and plasticity. Gregarious locusts live in a more complex sensory environment than solitarious locusts and may require a greater turnover of proteins involved in sensory transduction, and possibly greater neuronal plasticity

Transcriptome Analysis of the Desert Locust Central Nervous System: Production and Annotation of a Schistocerca gregaria EST Database

) displays a fascinating type of phenotypic plasticity, designated as ‘phase polyphenism’. Depending on environmental conditions, one genome can be translated into two highly divergent phenotypes, termed the solitarious and gregarious (swarming) phase. Although many of the underlying molecular events remain elusive, the central nervous system (CNS) is expected to play a crucial role in the phase transition process. Locusts have also proven to be interesting model organisms in a physiological and neurobiological research context. However, molecular studies in locusts are hampered by the fact that genome/transcriptome sequence information available for this branch of insects is still limited. EST information is highly complementary to the existing orthopteran transcriptomic data. Since many novel transcripts encode neuronal signaling and signal transduction components, this paper includes an overview of these sequences. Furthermore, several transcripts being differentially represented in solitarious and gregarious locusts were retrieved from this EST database. The findings highlight the involvement of the CNS in the phase transition process and indicate that this novel annotated database may also add to the emerging knowledge of concomitant neuronal signaling and neuroplasticity events. EST data constitute an important new source of information that will be instrumental in further unraveling the molecular principles of phase polyphenism, in further establishing locusts as valuable research model organisms and in molecular evolutionary and comparative entomology

Optimization of estimating glomerular filtration rate equations for the evaluation of kidney function in children, adolescents and adults

The glomerular filtration rate (GFR) is widely considered as the best overall index of kidney function in health and disease. Direct measurements of GFR are technically complicated and impractical to perform in routine clinical settings. That is why more simple methods to estimate the GFR are so successful. The calculation of the estimated (e)GFR using mathematical formulas has been encouraged as a simple, rapid and reliable way of assessing kidney function. In those formulas, serum creatinine (Scr) is most commonly used as a marker for renal function. A typical problem related to the use of creatinine-based eGFR-formulas is the existing diversity of methods to determine Scr. It has been shown that small analytical changes in Scr can create major shifts in the distributions of eGFR-results, which then cause differences in the Chronic Kidney Disease (CKD) classification of patients. So it is clear that control of laboratory analysis of Scr and worldwide standardized Scr measurements are necessary. Manufacturers already made efforts to standardize their Scr measurements to have calibration traceable to the isotope dilution mass spectrometry (IDMS) gold standard method. However calibration traceability does not address (analytical) non-specificity which remains of concern. Lately there have been recommendations to abandon the Jaffe Scr assay in favor of the enzymatic Scr assay since the enzymatic assays have been reported to have generally fewer interferences than the Jaffe methods. However the higher cost of the enzymatic assay is the main reason why some clinical labs still use Jaffe or compensated (compensation made for the mean creatinine-interference) Jaffe assays. Because of the evolution in laboratory testing of Scr to IDMS-standardized techniques, new eGFR-formulas have been developed for adults and children during the last decade but no attempts have been undertaken to develop new formulas for adolescents. Pediatric eGFR-formulas are often used in the adolescent population although these equations were not developed to be used in these patients and are not accurate for the adolescent population. Besides the use of eGFR-formulas, clinicians also often rely on 24-hour creatinine clearance (24h-CrCl) to estimate the kidney function. An advantage over the use of eGFR-formulas is that CrCl can be performed in people of all ages and in patients for whom Scr-based eGFR-formulas are not applicable (eg. pregnant women). However CrCl-determination has also its own specific problems such as the lack of accuracy of the 24h-urine collection and the huge diversity in serum and urine creatinine measurement methods which may lead to different CrCl-results. In the first part of this PhD-project (Chapter 2) we focused on the problems that may arise when working with Scr assays. To investigate the effect of Scr assays on 24h-CrCl we have set up a study to compare the CrCl calculated from three different type of assays (Jaffe (J), compensated Jaffe (CJ) and enzymatic (E) assay). We showed that CrCl determination is extremely assay-dependent. To evaluate the reliability of 24h-CrCl for estimating the kidney function, we compared the CrCl with eGFR-values calculated with the CKD-EPI eGFR-formula. The deviation of the body surface area indexed CrCl from the CKD-EPI eGFR illustrates that the use of CrCl in clinical practice remains questionable. Two compensating errors in the CrCl-J calculation result in a closer agreement with CKD-EPI eGFR, than between CrCl-CJ or CrCl-E and CKD-EPI eGFR. We therefore recommend clinical labs that work with compensated Jaffe assays not to compensate for the protein effect when a CrCl is requested. In a second study we investigated the accuracy and precision of commonly used Scr assays (J, CJ and E) in Flanders. Our interest was to study how results can vary among laboratories using different type of Scr assays and instruments. We conclude that although most assays claim to be traceable to IDMS, large inter-assay differences still exist. The inaccuracy in the lower concentration range is of particular concern and may lead to clinical misinterpretation when the creatinine-based eGFR of the patient is used for CKD staging. The second objective of the PhD-project (Chapter 3) was to develop and validate an equation based on IDMS-standardized Scr for estimating the GFR in adolescents. The new formula is based on the concept of population-normalized Scr. We first introduced this concept by reshaping existing eGFR-formulas for adults. Then we showed that the same concept could be used to develop a simple height-independent eGFR-formula for children. Next we extended the idea of normalized Scr to develop and validate two new eGFR-equations for adolescents and young adults. We also illustrated that the newly developed formulas have their limitations and are not applicable in patients with abnormally low Scr, such as Duchenne muscular dystrophy patients. Since separate equations for children, adolescents, adults and elderly lack continuity with aging, we also proposed a GFR estimating equation (by extending the equations for children and adolescents based on population-normalized Scr) valid for the full age spectrum. In the third part of the PhD-project (Chapter 4) we criticize the current CKD classification system which has been developed for adults, but is also considered to be applicable for children and adolescents. We presented an alternative CKD classification system based on normalized Scr. The alternative approach has the advantage of reducing the proportion of elderly that are (falsely) classified with CKD and increases sensitivity in classifying CKD in children and young adults. We also showed that abnormal GFR for children, adolescents and young adults starts below 75mL/min/1.73m², suggesting that this would be a good alternative for the CKD cut-off of 60 mL/min/1.73m².status: publishe

Response to the letter from Kallner: Comments on 'Does the type of creatinine assay affect creatinine clearance determination?'

peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=iclb20status: publishe

New insights in glomerular filtration rate formulas and chronic kidney disease classification

BACKGROUND: The MDRD Study equation is the most popular equation for estimating the glomerular filtration rate (eGFR) from serum creatinine (Scr), age, sex and race. Many articles deal with ethnic factors, correcting the MDRD Study equation for different populations, with more or less success. The new CKD-EPI equation introduced the concept of a population-normalized Scr in the eGFR equation for white men (Scr/0.90) and white women (Scr/0.70). METHODS: We introduce alternative mathematical forms for the MDRD Study equation and the CKD-EPI equation, using the concept of a population-normalized Scr, resulting in a more general and mathematically less complicated form for the eGFR equation. RESULTS: We show that the normalization constant corresponds to the mean Scr-value for the specific healthy population. We compared the established equations with the new alternative forms, and show that the differences are minimal. The sex/race dependency is completely comprehended in the normalization constant, making the alternative eGFR equations independent of sex and race. CONCLUSION: The age-dependency of eGFR remains and consequently age-dependent cutoff values for the classification of Chronic Kidney Disease (CKD) look more appropriate, contrary to the current classification rules. The population-normalized Scr which is independent of age, sex and race may serve as an alternative for the classification of CKD.status: publishe

Abnormal glomerular filtration rate in children, adolescents and young adults starts below 75 mL/min/1.73 m(2.)

The chronic kidney disease (CKD) classification system for children is similar to that for adults, with both mainly based on estimated glomerular filtration rate (eGFR) combined with fixed cut-off values. The main cut-off eGFR value used to define CKD is 60 mL/min/1.73 m(2), a value that is also applied for children older than 2 years of age, adolescents and young adults.status: publishe