Control of ventricular unloading using an electrocardiogram-synchronized Thoratec paracorporeal ventricular assist device

OBJECTIVE: Current pulsatile ventricular assist devices operate asynchronous with the left ventricle in fixed-rate or fill-to-empty modes because electrocardiogram-triggered modes have been abandoned. We hypothesize that varying the ejection delay in the synchronized mode yields more precise control of hemodynamics and left ventricular loading. This allows for a refined management that may be clinically beneficial. METHODS: Eight sheep received a Thoratec paracorporeal ventricular assist device (Thoratec Corp, Pleasanton, Calif) via ventriculo-aortic cannulation. Left ventricular pressure and volume, aortic pressure, pulmonary flow, pump chamber pressure, and pump inflow and outflow were recorded. The pump was driven by a clinical pneumatic drive unit (Medos Medizintechnik AG, Stolberg, Germany) synchronously with the native R-wave. The start of pump ejection was delayed between 0% and 100% of the cardiac period in 10% increments. For each of these delays, hemodynamic variables were compared with baseline data using paired t tests. RESULTS: The location of the minimum of stroke work was observed at a delay of 10% (soon after aortic valve opening), resulting in a median of 43% reduction in stroke work compared with baseline. Maximum stroke work occurred at a median delay of 70% with a median stroke work increase of 11% above baseline. Left ventricular volume unloading expressed by end-diastolic volume was most pronounced for copulsation (delay 0%). CONCLUSIONS: The timing of pump ejection in synchronized mode yields control over left ventricular energetics and can be a method to achieve gradual reloading of a recoverable left ventricle. The traditionally suggested counterpulsation is not optimal in ventriculo-aortic cannulation when maximum unloading is desired.

Static and Dynamic Error Correction of a Computer-Aided Mechanical Navigation Linkage for Arthroscopic Hip Surgery

While beneficially decreasing the necessary incision size, arthroscopic hip surgery increases the surgical complexity due to loss of joint visibility. To ease such difficulty, a computer-aided mechanical navigation system was developed to present the location of the surgical tool relative to the patient¿s hip joint. A preliminary study reduced the position error of the tracking linkage with limited static testing trials. In this study, a correction method, including a rotational correction factor and a length correction function, was developed through more in-depth static testing. The developed correction method was then applied to additional static and dynamic testing trials to evaluate its effectiveness. For static testing, the position error decreased from an average of 0.384 inches to 0.153 inches, with an error reduction of 60.5%. Three parameters utilized to quantify error reduction of dynamic testing did not show consistent results. The vertex coordinates achieved 29.4% of error reduction, yet with large variation in the upper vertex. The triangular area error was reduced by 5.37%, however inconsistent among all five dynamic trials. Error of vertex angles increased, indicating a shape torsion using the developed correction method. While the established correction method effectively and consistently reduced position error in static testing, it did not present consistent results in dynamic trials. More dynamic paramters should be explored to quantify error reduction of dynamic testing, and more in-depth dynamic testing methodology should be conducted to further improve the accuracy of the computer-aided nagivation system.

NADPH P450 oxidoreductase: structure, function, and pathology of diseases

Cytochrome P450 oxidoreductase (POR) is an enzyme that is essential for multiple metabolic processes, chiefly among them are reactions catalyzed by cytochrome P450 proteins for metabolism of steroid hormones, drugs and xenobiotics. Mutations in POR cause a complex set of disorders that often resemble defects in steroid metabolizing enzymes 17α-hydroxylase, 21-hydroxylase and aromatase. Since our initial reports of POR mutations in 2004, more than 200 different mutations and polymorphisms in POR gene have been identified. Several missense variations in POR have been tested for their effect on activities of multiple steroid and drug metabolizing P450 proteins. Mutations in POR may have variable effects on different P450 partner proteins depending on the location of the mutation. The POR mutations that disrupt the binding of co-factors have negative impact on all partner proteins, while mutations causing subtle structural changes may lead to altered interaction with specific partner proteins and the overall effect may be different for each partner. This review summarizes the recent discoveries related to mutations and polymorphisms in POR and discusses these mutations in the context of historical developments in the discovery and characterization of POR as an electron transfer protein. The review is focused on the structural, enzymatic and clinical implications of the mutations linked to newly identified disorders in humans, now categorized as POR deficiency.

Role of FGFRL1 and other FGF signaling proteins in early kidney development

The mammalian kidney develops from the ureteric bud and the metanephric mesenchyme. In mice, the ureteric bud invades the metanephric mesenchyme at day E10.5 and begins to branch. The tips of the ureteric bud induce the metanephric mesenchyme to condense and form the cap mesenchyme. Some cells of this cap mesenchyme undergo a mesenchymal-to-epithelial transition and differentiate into renal vesicles, which further develop into nephrons. The developing kidney expresses Fibroblast growth factor (Fgf)1, 7, 8, 9, 10, 12 and 20 and Fgf receptors Fgfr1 and Fgfr2. Fgf7 and Fgf10, mainly secreted by the metanephric mesenchyme, bind to Fgfr2b of the ureteric bud and induce branching. Fgfr1 and Fgfr2c are required for formation of the metanephric mesenchyme, however the two receptors can substitute for one another. Fgf8, secreted by renal vesicles, binds to Fgfr1 and supports survival of cells in the nascent nephrons. Fgf9 and Fgf20, expressed in the metanephric mesenchyme, are necessary to maintain survival of progenitor cells in the cortical region of the kidney. FgfrL1 is a novel member of the Fgfr family that lacks the intracellular tyrosine kinase domain. It is expressed in the ureteric bud and all nephrogenic structures. Targeted deletion of FgfrL1 leads to severe kidney dysgenesis due to the lack of renal vesicles. FgfrL1 is known to interact mainly with Fgf8. It is therefore conceivable that FgfrL1 restricts signaling of Fgf8 to the precise location of the nascent nephrons. It might also promote tight adhesion of cells in the condensed metanephric mesenchyme as required for the mesenchymal-to-epithelial transition.

A Robust Parser of Czech

Mr. Kubon's project was inspired by the growing need for an automatic, syntactic analyser (parser) of Czech, which could be used in the syntactic processing of large amounts of texts. Mr. Kubon notes that such a tool would be very useful, especially in the field of corpus linguistics, where creating a large-scale "tree bank" (a collection of syntactic representations of natural language sentences) is a very important step towards the investigation of the properties of a given language. The work involved in syntactically parsing a whole corpus in order to get a representative set of syntactic structures would be almost inconceivable without the help of some kind of robust (semi)automatic parser. The need for the automatic natural language parser to be robust increases with the size of the linguistic data in the corpus or in any other kind of text which is going to be parsed. Practical experience shows that apart from syntactically correct sentences, there are many sentences which contain a "real" grammatical error. These sentences may be corrected in small-scale texts, but not generally in the whole corpus. In order to be able to complete the overall project, it was necessary to address a number of smaller problems. These were; 1. the adaptation of a suitable formalism able to describe the formal grammar of the system; 2. the definition of the structure of the system's dictionary containing all relevant lexico-syntactic information, and the development of a formal grammar able to robustly parse Czech sentences from the test suite; 3. filling the syntactic dictionary with sample data allowing the system to be tested and debugged during its development (about 1000 words); 4. the development of a set of sample sentences containing a reasonable amount of grammatical and ungrammatical phenomena covering some of the most typical syntactic constructions being used in Czech. Number 3, building a formal grammar, was the main task of the project. The grammar is of course far from complete (Mr. Kubon notes that it is debatable whether any formal grammar describing a natural language may ever be complete), but it covers the most frequent syntactic phenomena, allowing for the representation of a syntactic structure of simple clauses and also the structure of certain types of complex sentences. The stress was not so much on building a wide coverage grammar, but on the description and demonstration of a method. This method uses a similar approach as that of grammar-based grammar checking. The problem of reconstructing the "correct" form of the syntactic representation of a sentence is closely related to the problem of localisation and identification of syntactic errors. Without a precise knowledge of the nature and location of syntactic errors it is not possible to build a reliable estimation of a "correct" syntactic tree. The incremental way of building the grammar used in this project is also an important methodological issue. Experience from previous projects showed that building a grammar by creating a huge block of metarules is more complicated than the incremental method, which begins with the metarules covering most common syntactic phenomena first, and adds less important ones later, especially from the point of view of testing and debugging the grammar. The sample of the syntactic dictionary containing lexico-syntactical information (task 4) now has slightly more than 1000 lexical items representing all classes of words. During the creation of the dictionary it turned out that the task of assigning complete and correct lexico-syntactic information to verbs is a very complicated and time-consuming process which would itself be worth a separate project. The final task undertaken in this project was the development of a method allowing effective testing and debugging of the grammar during the process of its development. The problem of the consistency of new and modified rules of the formal grammar with the rules already existing is one of the crucial problems of every project aiming at the development of a large-scale formal grammar of a natural language. This method allows for the detection of any discrepancy or inconsistency of the grammar with respect to a test-bed of sentences containing all syntactic phenomena covered by the grammar. This is not only the first robust parser of Czech, but also one of the first robust parsers of a Slavic language. Since Slavic languages display a wide range of common features, it is reasonable to claim that this system may serve as a pattern for similar systems in other languages. To transfer the system into any other language it is only necessary to revise the grammar and to change the data contained in the dictionary (but not necessarily the structure of primary lexico-syntactic information). The formalism and methods used in this project can be used in other Slavic languages without substantial changes.

Molecular characterization of the equine collagen, type IX, alpha 2 (COL9A2) gene on horse chromosome 2p16-->p15

The mammalian collagen, type IX, alpha 2 gene (COL9A2) encodes the alpha-2 chain of type IX collagen and is located on horse chromosome 2p16-->p14 harbouring a quantitative trait locus for osteochondrosis. We isolated a bacterial artificial chromosome (BAC) clone containing the equine COL9A2 gene and determined the complete genomic sequence of this gene. Cloning and characterization of equine COL9A2 revealed that the equine gene consists of 32 exons spanning approximately 15 kb. The COL9A2 transcript encodes a single protein of 688 amino acids. Thirty two single nucleotide polymorphisms (SNPs) equally distributed in the gene were detected in a mutation scan of eight unrelated Hanoverian warmblood stallions, including one SNP that affects the amino acid sequence of COL9A2. Comparative analyses between horse, human, mouse and rat indicate that the chromosomal location of equine COL9A2 is in agreement with known chromosomal synteny relationships. The comparison of the gene structure and transcript revealed a high degree of conservation towards the other mammalian COL9A2 genes. We chose three informative SNPs for association and linkage disequilibrium tests in three to five paternal half-sib families of Hanoverian warmblood horses consisting of 44 to 75 genotyped animals. The test statistics did not reach the significance threshold of 5% and so we could not show an association of COL9A2 with equine osteochondrosis.

Genetic analysis of syndactyly in German Holstein cattle

Congenital syndactyly with a variable number of affected feet was observed in eight black and white German Holstein calves. Analysis of the pedigree data revealed that all affected individuals could be traced back to a single founder. The pedigree was consistent with monogenic autosomal recessive inheritance and variable expressivity. Bovine syndactyly or "mulefoot" has been previously shown to map on the telomeric end of bovine chromosome 15 and we performed PCR genotyping of microsatellite markers spanning 27 cM of this chromosomal region to test the new cases for genetic linkage with the phenotype. The haplotype segregation confirmed the suggested inheritance pattern of the mulefoot mutation in this family and markers RM004, BM848 and BMS820 showed significant linkage to the phenotype. The results confirmed the chromosomal location of the mulefoot gene in this pedigree. Furthermore the study demonstrated that although marker testing has been available for nearly a decade the use of mulefoot carriers in cattle breeding remains uncontrolled. The presented family provides a resource for positional cloning of the causative mutation.

The structural architecture of adult mammalian articular cartilage evolves by a synchronized process of tissue resorption and neoformation during postnatal development

OBJECTIVE: During postnatal development, mammalian articular cartilage acts as a surface growth plate for the underlying epiphyseal bone. Concomitantly, it undergoes a fundamental process of structural reorganization from an immature isotropic to a mature (adult) anisotropic architecture. However, the mechanism underlying this structural transformation is unknown. It could involve either an internal remodelling process, or complete resorption followed by tissue neoformation. The aim of this study was to establish which of these two alternative tissue reorganization mechanisms is physiologically operative. We also wished to pinpoint the articular cartilage source of the stem cells for clonal expansion and the zonal location of the chondrocyte pool with high proliferative activity. METHODS: The New Zealand white rabbit served as our animal model. The analysis was confined to the high-weight-bearing (central) areas of the medial and lateral femoral condyles. After birth, the articular cartilage layer was evaluated morphologically at monthly intervals from the first to the eighth postnatal month, when this species attains skeletal maturity. The overall height of the articular cartilage layer at each juncture was measured. The growth performance of the articular cartilage layer was assessed by calcein labelling, which permitted an estimation of the daily growth rate of the epiphyseal bone and its monthly length-gain. The slowly proliferating stem-cell pool was identified immunohistochemically (after labelling with bromodeoxyuridine), and the rapidly proliferating chondrocyte population by autoradiography (after labelling with (3)H-thymidine). RESULTS: The growth activity of the articular cartilage layer was highest 1 month after birth. It declined precipitously between the first and third months, and ceased between the third and fourth months, when the animal enters puberty. The structural maturation of the articular cartilage layer followed a corresponding temporal trend. During the first 3 months, when the articular cartilage layer is undergoing structural reorganization, the net length-gain in the epiphyseal bone exceeded the height of the articular cartilage layer. This finding indicates that the postnatal reorganization of articular cartilage from an immature isotropic to a mature anisotropic structure is not achieved by a process of internal remodelling, but by the resorption and neoformation of all zones except the most superficial (stem-cell) one. The superficial zone was found to consist of slowly dividing stem cells with bidirectional mitotic activity. In the horizontal direction, this zone furnishes new stem cells that replenish the pool and effect a lateral expansion of the articular cartilage layer. In the vertical direction, the superficial zone supplies the rapidly dividing, transit-amplifying daughter-cell pool that feeds the transitional and upper radial zones during the postnatal growth phase of the articular cartilage layer. CONCLUSIONS: During postnatal development, mammalian articular cartilage fulfils a dual function, viz., it acts not only as an articulating layer but also as a surface growth plate. In the lapine model, this growth activity ceases at puberty (3-4 months of age), whereas that of the true (metaphyseal) growth plate continues until the time of skeletal maturity (8 months). Hence, the two structures are regulated independently. The structural maturation of the articular cartilage layer coincides temporally with the cessation of its growth activity - for the radial expansion and remodelling of the epiphyseal bone - and with sexual maturation. That articular cartilage is physiologically reorganized by a process of tissue resorption and neoformation, rather than by one of internal remodelling, has important implications for the functional engineering and repair of articular cartilage tissue.

Automatic extraction of the mid-facial plane for cranio-maxillofacial surgery planning

Recently developed computer applications provide tools for planning cranio-maxillofacial interventions based on 3-dimensional (3D) virtual models of the patient's skull obtained from computed-tomography (CT) scans. Precise knowledge of the location of the mid-facial plane is important for the assessment of deformities and for planning reconstructive procedures. In this work, a new method is presented to automatically compute the mid-facial plane on the basis of a surface model of the facial skeleton obtained from CT. The method matches homologous surface areas selected by the user on the left and right facial side using an iterative closest point optimization. The symmetry plane which best approximates this matching transformation is then computed. This new automatic method was evaluated in an experimental study. The study included experienced and inexperienced clinicians defining the symmetry plane by a selection of landmarks. This manual definition was systematically compared with the definition resulting from the new automatic method: Quality of the symmetry planes was evaluated by their ability to match homologous areas of the face. Results show that the new automatic method is reliable and leads to significantly higher accuracy than the manual method when performed by inexperienced clinicians. In addition, the method performs equally well in difficult trauma situations, where key landmarks are unreliable or absent.

Comparison of spatial and temporal pattern for fMRI obtained with BOLD and arterial spin labeling

Functional magnetic resonance imaging (fMRI) is presently either performed using blood oxygenation level-dependent (BOLD) contrast or using cerebral blood flow (CBF), measured with arterial spin labeling (ASL) technique. The present fMRI study aimed to provide practical hints to favour one method over the other. It involved three different acquisition methods during visual checkerboard stimulation on nine healthy subjects: 1) CBF contrast obtained from ASL, 2) BOLD contrast extracted from ASL and 3) BOLD contrast from Echo planar imaging. Previous findings were replicated; i) no differences between the three measurements were found in the location of the activated region; ii) differences were found in the temporal characteristics of the signals and iii) BOLD has significantly higher sensitivity than ASL perfusion. ASL fMRI was favoured when the investigation demands for perfusion and task related signal changes. BOLD fMRI is more suitable in conjunction with fast event related design.

Vertebral artery dissection: presenting findings and predictors of outcome

BACKGROUND AND PURPOSE: Few data exist about clinical, radiologic findings, clinical outcome, and its predictors in patients with spontaneous vertebral artery dissection (sVAD). METHODS: Clinical characteristics, imaging findings, 3-month outcomes, and its predictors were investigated in consecutive patients with sVAD. RESULTS: One hundred sixty-nine patients with 195 sVAD were identified. Brain ischemia occurred in 131 patients (77%; ischemic stroke, n=114, 67%; transient ischemic attack, n=17, 10%). Three patients with ischemic stroke showed also signs of subarachnoid hemorrhage (SAH); 3 (2%) had SAH without ischemia. The 134 patients with brain ischemia or SAH had head and/or neck pain in 118 (88%) and pulsatile tinnitus in seven (5%) patients. The remaining 35 patients (21%) had isolated head and/or neck pain in 21 (12%) cases, asymptomatic sVAD in 13 (8%), and cervical radiculopathy in one case (1%). Location of sVAD was more often in the pars transversaria (V2; 35%) or atlas loop (V3; 34%) than in the prevertebral (V1; 20%) or intracranial (V4; 11%) segment (P=0.0001). Outcome was favorable (modified Rankin scale score 0 or 1) in 88 (82%) of 107 ischemic stroke patients with follow up. Two (2%) patients died. Low baseline National Institutes of Health Stroke Scale score (P<0.0001) and younger age (P=0.007) were independent predictors of favorable outcome. CONCLUSIONS: sVAD is predominantly located in the pars transversaria (V2) or the atlas loop (V3). Most patients show posterior circulation ischemia. Favorable outcome is observed in most ischemic strokes and independently predicted by low National Institutes of Health Stroke Scale score and younger age.

Inferences regarding the diet of extinct hominins: structural and functional trends in dental and mandibular morphology within the hominin clade

This contribution investigates the evolution of diet in the Pan – Homo and hominin clades. It does this by focusing on 12 variables (nine dental and three mandibular) for which data are available about extant chimpanzees, modern humans and most extinct hominins. Previous analyses of this type have approached the interpretation of dental and gnathic function by focusing on the identification of the food consumed (i.e. fruits, leaves, etc.) rather than on the physical properties (i.e. hardness, toughness, etc.) of those foods, and they have not specifically addressed the role that the physical properties of foods play in determining dental adaptations. We take the available evidence for the 12 variables, and set out what the expression of each of those variables is in extant chimpanzees, the earliest hominins, archaic hominins, megadont archaic hominins, and an inclusive grouping made up of transitional hominins and pre-modern Homo . We then present hypotheses about what the states of these variables would be in the last common ancestor of the Pan – Homo clade and in the stem hominin. We review the physical properties of food and suggest how these physical properties can be used to investigate the functional morphology of the dentition. We show what aspects of anterior tooth morphology are critical for food preparation (e.g. peeling fruit) prior to its ingestion, which features of the postcanine dentition (e.g. overall and relative size of the crowns) are related to the reduction in the particle size of food, and how information about the macrostructure (e.g. enamel thickness) and microstructure (e.g. extent and location of enamel prism decussation) of the enamel cap might be used to make predictions about the types of foods consumed by extinct hominins. Specifically, we show how thick enamel can protect against the generation and propagation of cracks in the enamel that begin at the enamel– dentine junction and move towards the outer enamel surface.

Penetration ability and microleakage of a fissure sealant applied on artificial and natural enamel fissure caries

OBJECTIVES AND METHODS: This study investigated the sealing ability of a current available unfilled fissure sealant applied over sound (n=80), artificially created (n=80) and naturally carious fissures (n=80) under different humidity conditions (90+/-2 and 45+/-2% relative humidity) and etching times (40 and 60s). All samples were submitted to 5000 thermal cycles and examined by light microscopy after sectioning. Microleakage, penetration ability, fissure type, fissure entrance angle, sealant occlusal length, caries location and caries depth were assessed. RESULTS: The significantly longer sealant occlusal length and larger entrance angle exhibited by shallow fissures, contributed to their higher microleakage and smaller amounts of unfilled areas compared to deep fissures. Sealant microleakage was significantly influenced by the condition of the enamel (sound, artificial and natural caries) and the caries location in the fissures, but not by enamel caries depth (D1 and D2), etching time, or humidity condition. Natural caries exhibited significantly higher microleakage than sound or artificially created carious fissures. CONCLUSIONS: Based on the results of this study, it can be concluded that location of caries in the fissure rather than its depth should be taken into account when applying a fissure sealant. When the borders of the fissure sealant are on carious enamel, a significantly higher microleakage must be expected. The artificial caries model was not a suitable method to assess the behavior of natural fissure caries.

Biological safety concepts of genetically modified live bacterial vaccines

Live vaccines possess the advantage of having access to induce cell-mediated and antibody-mediated immunity; thus in certain cases they are able to prevent infection, and not only disease. Furthermore, live vaccines, particularly bacterial live vaccines, are relatively cheap to produce and easy to apply. Hence they are suitable to immunize large communities or herds. The induction of both cell-mediated immunity as well as antibody-mediated immunity, which is particularly beneficial in inducing mucosal immune responses, is obtained by the vaccine-strain's ability to colonize and multiply in the host without causing disease. For this reason, live vaccines require attenuation of virulence of the bacterium to which immunity must be induced. Traditionally attenuation was achieved simply by multiple passages of the microorganism on growth medium, in animals, eggs or cell cultures or by chemical or physical mutagenesis, which resulted in random mutations that lead to attenuation. In contrast, novel molecular methods enable the development of genetically modified organisms (GMOs) targeted to specific genes that are particularly suited to induce attenuation or to reduce undesirable effects in the tissue in which the vaccine strains can multiply and survive. Since live vaccine strains (attenuated by natural selection or genetic engineering) are potentially released into the environment by the vaccinees, safety issues concerning the medical as well as environmental aspects must be considered. These involve (i) changes in cell, tissue and host tropism, (ii) virulence of the carrier through the incorporation of foreign genes, (iii) reversion to virulence by acquisition of complementation genes, (iv) exchange of genetic information with other vaccine or wild-type strains of the carrier organism and (v) spread of undesired genes such as antibiotic resistance genes. Before live vaccines are applied, the safety issues must be thoroughly evaluated case-by-case. Safety assessment includes knowledge of the precise function and genetic location of the genes to be mutated, their genetic stability, potential reversion mechanisms, possible recombination events with dormant genes, gene transfer to other organisms as well as gene acquisition from other organisms by phage transduction, transposition or plasmid transfer and cis- or trans-complementation. For this, GMOs that are constructed with modern techniques of genetic engineering display a significant advantage over random mutagenesis derived live organisms. The selection of suitable GMO candidate strains can be made under in vitro conditions using basic knowledge on molecular mechanisms of pathogenicity of the corresponding bacterial species rather than by in vivo testing of large numbers of random mutants. This leads to a more targeted safety testing on volunteers and to a reduction in the use of animal experimentation.

Modeling of electroosmotic and electrophoretic mobilization in capillary and microchip isoelectric focusing

Our dynamic capillary electrophoresis model which uses material specific input data for estimation of electroosmosis was applied to investigate fundamental aspects of isoelectric focusing (IEF) in capillaries or microchannels made from bare fused-silica (FS), FS coated with a sulfonated polymer, polymethylmethacrylate (PMMA) and poly(dimethylsiloxane) (PDMS). Input data were generated via determination of the electroosmotic flow (EOF) using buffers with varying pH and ionic strength. Two models are distinguished, one that neglects changes of ionic strength and one that includes the dependence between electroosmotic mobility and ionic strength. For each configuration, the models provide insight into the magnitude and dynamics of electroosmosis. The contribution of each electrophoretic zone to the net EOF is thereby visualized and the amount of EOF required for the detection of the zone structures at a particular location along the capillary, including at its end for MS detection, is predicted. For bare FS, PDMS and PMMA, simulations reveal that EOF is decreasing with time and that the entire IEF process is characterized by the asymptotic formation of a stationary steady-state zone configuration in which electrophoretic transport and electroosmotic zone displacement are opposite and of equal magnitude. The location of immobilization of the boundary between anolyte and most acidic carrier ampholyte is dependent on EOF, i.e. capillary material and anolyte. Overall time intervals for reaching this state in microchannels produced by PDMS and PMMA are predicted to be similar and about twice as long compared to uncoated FS. Additional mobilization for the detection of the entire pH gradient at the capillary end is required. Using concomitant electrophoretic mobilization with an acid as coanion in the catholyte is shown to provide sufficient additional cathodic transport for that purpose. FS capillaries dynamically double coated with polybrene and poly(vinylsulfonate) are predicted to provide sufficient electroosmotic pumping for detection of the entire IEF gradient at the cathodic column end.