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Biomedical subjects

J Jung

Publications and source records attributed to J Jung.

At least 19 recordsLinked to original sources
PubMed2001

Recovery of sodium sulfate from farm drainage salt for use in reactive dyeing of cotton.

Agricultural drainage salt generated during irrigation of crops in San Joaquin Valley, California, exceeds 600,000 tons annually and cumulates in the field at a rapid rate. As a result, the waste is occupying more farmland for salt storage and disposal, thus causing serious concern to the environment and the local agricultural industry. In searching for a potential solution to reduce or eliminate the waste, the research describe herein explored the feasibility of producing a value-added product, sodium sulfate, from the waste and utilizing the product in textile dyeing. The results indicated that sodium sulfate could be produced from the salt and could be purified by a recrystalization method in a temperature range within the highest and lowest daily temperatures during summer in the valley. The recovered sodium sulfate samples, with purities ranging from 67 to 99.91%, were compared with commercially available sodium sulfate used in reactive dyeing of cotton fabrics. The salt samples recovered from Mendota, California (>98.8% sodium sulfate), cause little color difference in the dyeing with selected reactive dyes. The purified salt (III) (99.91% sodium sulfate) is more applicable for reactive dyeing of cotton fabrics since it has no deleterious effect. The recovered sodium sulfate from certain areas in the valley could not be employed in reactive dyeing due to the high level of impurities present.

Agriculture↗
PubMed2001

The distinct roles of T cell-derived cytokines and a novel follicular dendritic cell-signaling molecule 8D6 in germinal center-B cell differentiation.

Germinal center-B (GC-B) cells differentiate into memory B cells and plasma cells (PC) through interaction with T cells and follicular dendritic cells (FDC). Activated T cell and FDC play distinct roles in this process. The detailed kinetic experiments revealed that cytokines secreted by activated T cells determined the pathway of GC-B cell differentiation. IL-4 directs GC-B cells to differentiate into memory B cells, whereas IL-10 steers them into PC. FDC/HK cells do not direct either pathway, but provide signals for proliferation of GC-B cells. A novel FDC-signaling molecule 8D6 (FDC-SM-8D6) produced by FDC augments PC generation in the GC. FDC-SM-8D6-specific mAb blocked PC generation and IgG secretion but not memory B cell proliferation. COS cells expressing FDC-SM-8D6 enhanced GC-B cell proliferation and Ab secretion, which was blocked by mAb 8D6. In the cultures with B cell subsets, PC generation was inhibited by mAb 8D6 in the cultures with CD27(+) B cells but not in the culture with CD27(-) B cells, suggesting that CD27(+) PC precursor is the specific target of FDC-SM-8D6 stimulation.

Antibodies, Blocking↗
PubMed2001

[Anticoagulation in primary prevention of thromboembolism in advanced left ventricular dysfunction].

BACKGROUND: Patients with heart failure have an increased risk for thromboembolic events. In clinical practice the physician is often confronted with the decision to establish a prophylactic anticoagulation. DATA: The incidence for clinical embolization is 1.5 to 3.5% per year. It seems that patients with a lower peak oxygen uptake and with a lower ejection fraction are at higher risk for embolic events. There is no evidence for a correlation of such events with the clinical classification (NYHA) or with the genesis of heart failure. Concerning a prophylactic anticoagulation, the results of the published studies and meta-analyses are inhomogenous with a benefit in some, no difference in others and a significant disadvantage for the patients with anticoagulation in a part of them compared to a non-treated control group. None of these data is established by a prospective, randomized, controlled study with the primary endpoint thromboembolic event in patients with or without anticoagulation. The incidence for a hemorrhage under anticoagulation is 0.6-5.3% per year for life-threatening and 0.04-0.64% for fatal bleeding. CONCLUSION: Because of similar incidences for thromboembolic events and for the bleeding complication of anticoagulation, there is no evidence for a general indication for anticoagulation of patients with heart failure, persistent sinus rhythm and lack of risk factors. In patients with high-grade heart failure (e.g. VO2max < 14 ml/min/kg body weight or left ventricular ejection fraction < 20-30%), who belong to a high-risk population, anticoagulation should be considered and may be acceptable in individual cases.

Anticoagulants↗
PubMed2001

Effects of amount of milk, milk flow and access to a rubber teat on cross-sucking and non-nutritive sucking in dairy calves.

The aim of this study was to test the effects of different amounts of milk, flow rate of milk, and access to a teat after milk intake on non-nutritive sucking on an empty teat and on cross-sucking on other calves in Bos taurus dairy calves. An additional aim was to test if calves prefer to perform non-nutritive sucking on a teat with the taste of milk or on a clean teat. First experiment involved 11 groups of three calves during gradual decrease from 5 to 2.5 and 1 to 0l of whole milk per meal twice daily. Milk flow was either 0.5 or 1l/min, and the teat buckets were either left or removed after milk intake. When the calves were fed with 5l of milk, non-nutritive sucking and cross-sucking decreased (P<0.001), compared to 1 and 2.5l. Removing the empty teat after milk intake increased cross-sucking (P<0.001). Slow milk flow reduced non-nutritive sucking after milk intake (P<0.05), but did not influence cross-sucking. Duration of recorded milk intake was similar with fast flow and 5l of milk, compared to slow flow and 2.5l of milk. The latter combination increased non-nutritive sucking and cross-sucking, suggesting that amount of milk is more important than duration of milk intake.Second experiment was carried out on 12 individually kept calves. The calves received 2.5l of milk either in an open bucket, in a rubber teat bucket, or half/half in both buckets. When not used for feeding, the open bucket and the teat bucket were filled and emptied again to make them 'tasty' with some drops of milk. The tasty teat bucket was either removed or present after milk intake. The calves had always access to a second clean teat bucket. Source of milk had no influence on recorded behaviour after milk intake. The tasty teat was sucked for twice as long as the clean one when both teats were present (P<0.001). When the tasty teat was removed, the calves increased sucking on the clean teat (P<0.001), but decreased total time spent sucking (P<0.001). We conclude that a high amount of milk and the presence of the teat bucket after milk intake reduces cross-sucking, and that a clean teat is less effective in encouraging calves to suck than a teat with taste of milk.

Journal Article↗
PubMed2001

COBRA encodes a putative GPI-anchored protein, which is polarly localized and necessary for oriented cell expansion in Arabidopsis.

To control organ shape, plant cells expand differentially. The organization of the cellulose microfibrils in the cell wall is a key determinant of differential expansion. Mutations in the COBRA (COB) gene of Arabidopsis, known to affect the orientation of cell expansion in the root, are reported here to reduce the amount of crystalline cellulose in cell walls in the root growth zone. The COB gene, identified by map-based cloning, contains a sequence motif found in proteins that are anchored to the extracellular surface of the plasma membrane through a glycosylphosphatidylinositol (GPI) linkage. In animal cells, this lipid linkage is known to confer polar localization to proteins. The COB protein was detected predominately on the longitudinal sides of root cells in the zone of rapid elongation. Moreover, COB RNA levels are dramatically upregulated in cells entering the zone of rapid elongation. Based on these results, models are proposed for the role of COB as a regulator of oriented cell expansion.

Amino Acid Sequence↗
PubMed2001

Interaction of the alpha subunit of Na,K-ATPase with cofilin.

The alpha1 subunit of rat Na,K-ATPase, composed of 1018 amino acids, is arranged in the membrane so that the middle third of the polypeptide forms a large cytoplasmic loop bordered on both sides by multiple transmembrane segments. To identify proteins that might interact with the large cytoplasmic loop of Na,K-ATPase and potentially affect the function and/or the disposition of the pump in the cell, the yeast two-hybrid system was used to screen a rat skeletal muscle cDNA library. Several cDNA clones were isolated, some of which coded for cofilin, an actin-binding protein. Cofilin was co-immunoprecipitated with the alpha subunit of Na,K-ATPase from extracts of COS-7 cells transiently transfected with haemagglutinin-epitope-tagged cofilin cDNA as well as from yeast extracts. By means of deletion analysis we showed that the segment of cofilin between residues 45 and 99 is essential for functional association with the large cytoplasmic loop of Na,K-ATPase. Recombinant cofilin was shown to bind to the membrane-bound Na,K-ATPase; the association between the two proteins was demonstrated by confocal microscopy. The increased level of cofilin in transfected COS-7 cells caused an increase in the rate of ouabain-sensitive (86)Rb(+) uptake, indicating that cofilin elicits, either directly or indirectly, enhanced Na,K-ATPase activity and that the interaction occurs in vivo.

Actin Depolymerizing Factors↗
PubMed2001

A soluble auxin-binding protein, ABP57. Purification with anti-bovine serum albumin antibody and characterization of its mechanistic role in the auxin effect on plant plasma membrane H+-ATPase.

ABP(57) is an auxin-binding protein that possesses receptor function. In this study, a protocol for ABP(57) purification was developed on the basis of cross-reactivity shown between ABP(57) and antisera raised against bovine serum albumin, which enabled us to purify ABP(57) with a high yield and to further characterize it. ABP(57) activates plant plasma membrane H(+)-ATPase (PM H(+)-ATPase) via direct interaction. The binding of indole-3-acetic acid (IAA) to the primary binding site on ABP(57) caused a marked increase in the affinity of ABP(57) for PM H(+)-ATPase, which was accompanied by a change in ABP(57) conformation. Meanwhile, additional IAA binding to the secondary site on ABP(57) nullified the initial effect without inducing further conformational change. When ABP(57) with IAA occupying only the primary site interacted with PM H(+)-ATPase, no IAA could access the secondary site. These results suggest that IAA-induced biphasic alteration in the affinity of ABP(57) for PM H(+)-ATPase correlates with a bell-shaped dose response of the enzyme to IAA. There is also a possibility that, whereas the stimulation phase of the response is associated with a conformational change of ABP(57), the destimulation phase probably results from hindrance arising directly from the presence of IAA at the secondary site.

Animals↗
PubMed2001

Microscopic and macroscopic approaches of Cu(II) removal by FSM-16.

The removal of Cu(II) by a mesoporous material, FSM-16, was studied using electron paramagnetic resonance (EPR) spectroscopy and surface complexation modeling (SCM). Free copper ions, adsorbed and precipitated Cu(II) species were qualitatively identified by in situ EPR spectroscopy of Cu-FSM-16 suspensions at room temperature and at 77 K. In addition, the adsorbed species was identified as a Cu(II) species with an axial symmetry from an analysis of the EPR spectra of "dry" Cu-FSM-16 at 77 K. On the basis of the EPR results, the removal of Cu(II) as a function of pH under various experimental conditions was successfully simulated by assuming two removal mechanisms such as surface complexation and surface precipitation. In the acidic pH range (< pH 6), free copper ions were predominant, and surface complexed then surface precipitated species became dominant as the pH increased.

Adsorption↗
PubMed2001

Development and application of a sorption data base for the performance assessment of a radwaste repository.

A sorption data base (SDB) provides readily available data for the performance assessment of a radwaste repository when site-specific and/or reference data are needed. The software developed at KAERI, SDB-21C, is a graphic user interface (GUI) program that provides efficient and user-friendly tools for evaluating large amount of sorption data. In addition, the most comprehensive sorption data base that contains about 11,000 NEA data and 2,000 KAERI data was compiled in the program. Besides the simple Kd approach, a parametric model and its compiled data sets are also included in the SDB-21C. In order to evaluate the versatility of SDB-21C, several applications were performed for relevant hypothetical situations.

Adsorption↗
PubMed2001

Protein structure prediction.

The prediction of protein structure, based primarily on sequence and structure homology, has become an increasingly important activity. Homology models have become more accurate and their range of applicability has increased. Progress has come, in part, from the flood of sequence and structure information that has appeared over the past few years, and also from improvements in analysis tools. These include profile methods for sequence searches, the use of three-dimensional structure information in sequence alignment and new homology modeling tools, specifically in the prediction of loop and side-chain conformations. There have also been important advances in understanding the physical chemical basis of protein stability and the corresponding use of physical chemical potential functions to identify correctly folded from incorrectly folded protein conformations.

Animals↗
PubMed2001

Kinetic analysis of disruption of excess activated sludge by Dyno Mill and characteristics of protein release for recovery of useful materials.

Solubilization of excess sludge (ES) cultivated in a laboratory and that obtained from real wastewater treatment plants by continuous Dyno Mill disruption were studied for the purpose of effective reuse of ES. The total soluble protein concentration released during the ES disruption was found to be closely dependent upon the released protease activity, which suggests the possibility of the enzyme recovery as one of the ES reuse methods. The operating parameters of Dyno Mill significantly affected the ES solubilization. A high ES solubilization ratio of about 53%, defined by soluble TOC per total carbon contained in the laboratory-cultivated ES, was achieved by using glass beads of 0.5mm in diameter with the 60% (v/v) bead loading at the disc agitating speed of 3200rpm. The ES solubilization by the continuous mill disruption was successfully analyzed by a kinetic model consisting of first-order disruption kinetics. The collision frequency between the moving beads correlated well with the ES solubilization rate constant under all the operating conditions. This study proposes the applicability of mill disruption to the ES solubilization and to its reuse process.

Journal Article↗
PubMed2001

Establishment of a follicular lymphoma cell line (FLK-1) dependent on follicular dendritic cell-like cell line HK.

A novel cell line, FLK-1, was established from bone marrow cells of a patient with follicular lymphoma by means of co-culture with follicular dendritic cell (FDC)-like cell line HK. Immunophenotypic analysis showed that FLK-1 expressed CD10, CD19, CD20, CD38, IgG and HLA-DR, which is a typical feature of germinal center B cells. Cytogenetic analysis of FLK-1 demonstrated t(14;18)(q32;q21) translocation involving BCL2 and immunoglobulin heavy chain genes. Especially noteworthy is that the growth of FLK-1 was found to be dependent on a FDC line, HK. When HK cells were removed from the culture, FLK-1 cells stopped growing and eventually died. An apoptotic mechanism appeared to be involved as indicated by the presence of chromosome condensation and DNA ladder formation. The culture experiment using micropore membranes showed that soluble factor(s) of HK cells supported the growth, while direct cell-to-cell contact appeared to be necessary for longterm cell proliferation. These findings suggest the importance of the micro-environment for follicular lymphoma cells to grow. The FLK-1 cell line may thus prove to be useful for studying the growth mechanism of follicular lymphoma and provide new insights into the pathogenesis of follicular lymphoma.

Cell Communication↗
PubMed2001

Circularly permuted proteins in the protein structure database.

Some proteins are homologous to others after their sequence is circularly permuted. A few such proteins have been recognized, mainly by sequence comparison, but also by comparing their three-dimensional structures. Here we report the result of a systematic search for all protein pairs in the SCOP 90% id domain database that become structurally superimposable when the sequence of one of the pairs is circularly permuted. Using a reasonable set of criteria, we find that 47% of all protein domains are superimposable to at least one other protein domain in the database after their sequence is circularly permuted. Many of these are symmetric proteins, which superimpose to another protein both with and without a circular permutation of the sequence. However, 412 of the total 3035 domains are nonsymmetric, and these become structurally superimposable to another protein only after a circular permutation of the sequence. These include most known and many previously undetected circularly permuted proteins with remote homology.

Amino Acid Sequence↗
PubMed2001

Classification of endocardial electrograms using adapted wavelet packets and neural networks.

The discrimination of ventricular tachycardias with 1:1 retrograde conduction from sinus tachycardia still remains a challenge for rate based algorithms commonly used in dual-chamber implantable cardioverter defibrillators. Morphology based analysis techniques for a classification of antegrade and retrograde atrial activation patterns can be used to cope with this problem. Here time-domain template matching techniques are known approaches. However, a time-domain representation of endocardial electrograms is not optimal for classification tasks as the dimensionality of the underlying signal space is high and features being irrelevant for a signal characterization are involved in the analysis. Therefore, the aim of this study is to develop an enhanced morphological analysis tool for a classification of antegrade and retrograde atrial activation by using a transform domain representation of endocardial electrograms. For this, we applied an adapted wavelet-packet decomposition to extract discriminating features in endocardial electrograms representing antegrade and retrograde activation patterns. Further, a feed-forward neural network was utilized to produce a classification based on the extracted information. In using our hybrid method, no false classification of the physiological and pathological cardiac state was made. It is concluded that the proposed classification scheme represents a highly efficient approach for a classification of antegrade and retrograde atrial activation.

Algorithms↗
PubMed2001

A bipotential precursor population for pancreas and liver within the embryonic endoderm.

The pancreas emerges independently from dorsal and ventral domains of embryonic gut endoderm. Gene inactivation experiments in mice have identified factors required for dorsal pancreas development, but factors that initiate the ventral pancreas have remained elusive. In this study, we investigated the hypothesis that the emergence of the ventral pancreas is related to the emergence of the liver. We find that the liver and ventral pancreas are specified at the same time and in the same general domain of cells. Using embryo tissue explantation experiments, we find that the default fate of the ventral foregut endoderm is to activate the pancreas gene program. FGF signalling from the cardiac mesoderm diverts this endoderm to express genes for liver instead of those for pancreas. No evidence was found to indicate that the cell type choice for pancreas or liver involves a selection for growth or viability. Cardiac mesoderm or FGF induces the local expression of sonic hedgehog, which in turn is inhibitory to pancreas but not to liver. The bipotential precursor cell population for pancreas and liver in embryonic development and its fate selection by FGF has features that appear to be recapitulated in the adult pancreas and are reflected in the evolution of these organs.

Animals↗
PubMed2001

Enhancement of nitrifying biofilm formation using selected EPS produced by heterotrophic bacteria.

The possibility of enhancing nitrifying biofilm formation rate with the aid of selected EPS produced by heterotrophic bacteria was investigated. When EPS production characteristics were examined for four kinds of heterotrophs isolated from a domestic wastewater treatment reactor, two strains obtained from biofilms (B1, B2) exhibited a higher polysaccharide production rate than those from suspended flocs (A1, A2). Among EPS components, the concentration of uronic acids gave a good correlation with flocculation ability, which suggests that acidic polysaccharides play a major role in bioaggregate formation. Addition of 1 g/L D-glucuronic acid as an EPS substitute enhanced the homocoagulation rate of autotrophic Nitrosomonas europaea and altered its zeta potential from ñ30.4 mV to +4.3 mV, which indicates a possibility that particular EPS components produced by heterotrophs are utilized as neutralising reagents for nitrifying biofilm formation. Moreover, when heterotrophic isolates with Nitrobacter winogradskyi were cultured in batch with fabric supports, biofilm formed on the substratum. These experimental results suggest the application of selected EPS for enhancing nitrifying biofilm formation.

Bacteria↗
PubMed2000

Identification of the self-interaction of rat TCTP/IgE-dependent histamine-releasing factor using yeast two-hybrid system.

To further understand the biological function of translationally controlled tumor protein (TCTP), also known as IgE-dependent histamine-releasing factor (HRF), the yeast two-hybrid system was used to screen interacting molecules. We isolated cDNA clones coding for TCTP/HRF, suggesting that it may have a self-interacting property. Domain mapping of the interaction revealed that the C-terminal region of residue 126-172 is involved in self-interaction. The self-interacting property of TCTP/HRF was further supported by FPLC gel-filtration chromatography and coimmunoprecipitation analysis from transfected COS-7 cells. Our data suggests that TCTP/HRF may have a potential to self-interact through the C-terminal region, and the self-interaction property may be related to its biological function.

Animals↗