bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antigen‐Antibody Binding Kinetics for Biosensors: The Fractal Dimension and the Binding Rate Coefficient
Authors: Sadana Ajit 
Published: March 2005

AbstractThe diffision‐limited binding kinetics of antigen (or antibody or substrate)in solution to antibody (or antigen or enzyme) immobilized on a biosensor surface is analyzed within a fractal framework. The change in the fractal dimension, Df, is in the same direction as that in the forward binding rate coefficient, k1. An increase or decrease in the fractal dimension, Df leads to an increase or decrease in the forward binding rate coefficient, k1 respectively, irrespective of whether the antigen or the antibody is immobilized on the biosensor surface. For example, an increase in the concentration of IgG (MRC OX‐19) (antigen) in solution from 1 to 10 μg/mL bound to polyclonal sheep anti‐mouse IgG (antibody) immobilized on immunomagnetic beads leads to decreases in Df from 1.93 to 0.517 and in k1 from 2.72 to 0.064, respectively. The different examples analyzed and presented together indicate one means by which the forward binding rate coefficient, k1, may be controlled, that is, by changing the fractal dimension or the disorder on the surface. The versatility of the analysis is indicated by applying it to different examples for both types of systems, wherein either the antigen or antibody is immobilized on the surface. The analysis should assist in improving the stability, sensitivity, and response time of biosensors.
Batch and Semicontinuous Aggregation and Sedimentation of Hybridoma Cells by Acoustic Resonance Fields
Authors: Pui Phylis W. S. , Trampler Felix , Sonderhoff Stefan A. , Groeschl Martin , Kilburn Douglas G. , Piret James M. 
Published: March 2005

AbstractUltrasound was used to enhance the sedimentation of hybridoma cells from medium in a 75 mL resonator chamber. Forces in the acoustic standing waves aggregated the cells, and the aggregates were then rapidly sedimented by gravity. Cell separation increased with acoustic treatment time and cell concentration. The separation efficiency was over 97% for cell concentrations between 1066 and 107 cells/mL. During acoustic treatment at 180 W/L, the medium temperature increased at a rate of 1.3 °C/min. Ultrasonic exposures up to 220 W/L did not influence the viability or subsequent growth and antibody production of the cells. A decrease in cell viability was observed at a power level of 260 W/L. Batch separation efficiencies were as high as 98%. Acoustic separation was tested under semicontinuous operation, and above 90% separation efficiency was achieved at a flow rate of 0.7 L/h.
Microbial Polysaccharides of Applied Interest: Ongoing Research Activities in Europe
Authors: Crescenzi Vittorio 
Published: March 2005

AbstractAfter an introductory note on the main reasons underlying the interest in microbial polysaccharides as subjects of fundamental structural/physicochemical investigations, as well as of applied studies, and after a brief historical account, a survey is offered of ongoing research activities in Europe in the broad field of carbohydrate polymers of microbial origin. Attention is drawn to glycopolymers of actual or potential industrial relevance.
Characterization of a Bench‐Scale System for Studying the Biodegradation of Organic Solid Wastes
Authors: Tseng David Y. , Chalmers Jeffrey J. , Tuovinen Olli H. , Hoitink Harry A. J. 
Published: March 2005

AbstractA bench‐scale system was developed that through its use contributes toward a more fundamental understanding of the composting process. The computer‐controlled system maintained temperature and moisture levels within narrow ranges in thin layers of compost positioned on nylon mesh trays within the vessel. This system minimized complications caused by gradients observed in earlier systems. Specific O2 consumption and CO2 evolution rates were determined on the basis of dynamic mass balances. Water was introduced intermittently. Microbial biomass (ATP) was monitored at specific time intervals throughout the process. The system allows close observation of decomposition of feed materials at constant temperature and moisture levels throughout the process.
Use of an Acrylic Ester Sorbent for the Selective Adsorption of Avermectins
Authors: Chaubal Mahesh V. , Payne Gregory F. 
Published: March 2005

AbstractPrevious work has shown that simple model solutes differing in their abilities to form hydrogen bonds can be selectively adsorbed from a nonpolar solvent onto an acrylic ester sorbent (Amberlite XAD‐7). The goal of this work was to determine whether these sorbents could be used for the selective adsorption of members of the avermectin family of secondary metabolites. When the individual avermectins were studied, avermectin B2a, which has four hydroxyl groups, was observed to adsorb from hexane with a higher affinity than avermectins A2a or B1a, which have only three hydroxyl groups each. When equimolar mixtures of the three avermectins were studied, it was observed that avermectin B2a was preferentially adsorbed from hexane with separation factors of 2.2 × 0.2 and 1.8 × 0.2 relative to avermectins A2a and B1a, respectively.
Metabolic Engineering of Escherichia coli To Enhance Recombinant Protein Production through Acetate Reduction
Authors: Aristidou Aristos A. , San Ka ‐Yiu , Bennett George N. 
Published: March 2005

AbstractGenetic and metabolic engineering provide powerful and effective tools for the systematic manipulation and fine tuning of cellular metabolic activities. In this study, successful application of such techniques to enhance recombinant protein production by reducing acetate accumulation in Escherichia coli is presented. The alsS gene from Bacillus subtilis encoding the enzyme acetolactate synthase was introduced into E. coli cells using a multicopy plasmid. This newly introduced heterologous enzyme modifies the glycolytic fluxes by redirecting excess pyruvate away from acetate to acetolactate. Acetolactate is then converted to a nonacidic and less harmful byproduct acetoin, which appears in the broth. Furthermore, comparative fermentation studies show that the reduction in acetate accumulation leads to a significant improvement of recombinant protein production. The expression of a model recombinant CadA/β‐galactosidase fusion protein, under the control of a strong pH‐regulated promoter, was found to increase by about 60% for the specific protein activity (to a level of 30% of total cellular protein) and 50% in terms of the volumetric activity in a batch fermenter. In fed‐batch cultivation, the engineered strain achieved a volumetric recombinant protein yield of 1.6 million units/mL (about 1.1 g/L of β‐galactosidase), which represented a 220% enhancement over the control strain. In the meantime, acetate excretion was maintained below 20 mM compared with 80 mM for the control, and the final cell density was improved by 35%.
Conversion of Mixed Waste Office Paper to Ethanol by Genetically Engineered Klebsiella oxytoca Strain P2
Authors: Brooks T. A. , Ingram L. O. 
Published: March 2005

AbstractUnsorted, mixed waste office paper (MWOP) is an excellent substrate for conversion into fuel ethanol using a recombinant strain of Klebsiella oxytoca which ferments cellobiose and cellotriose to ethanol at near theoretical yields, eliminating the need for supplemental β‐glucosidase. This organism was tested with commercial fungal cellulase in optimized simultaneous saccharification and fermentation experiments (SSF) using MWOP as a substrate (pH 5–15.2, 35 °C). Similar rates and yields were obtained with dilute acid‐pulped (hydrolysis of hemicellulose) and water‐pulped MWOP on a dry weight basis although viscosity was reduced by the acid pretreatment. In simple batch fermentations, 40 g/L ethanol was produced after 48–72 h with 100 g/L MWOP and 1000 filter paper units (FPU) of cellulase/L, a yield of 550 L of ethanol/metric ton. Cellulase usage was further reduced by recycling SSF residues containing bound enzymes in multistage fermentations. This approach reduced the requirement for fungal cellulase while retaining rapid ethanol production and high ethanol yield. In our optimal design, broths containing an average of 39.6 g/L ethanol were produced in three successive stages with an average fermentation time of 80 h (567 FPU of fungal cellulase/L; 6.1 FPU/g of substrate). This represents a yield of 0.426 g of ethanol/g of substrate, 539 L/metric ton, 129 gal/U.S. ton. MWOP contains approximately 90% carbohydrate. Thus the combined efficiency for saccharification and fermentation to ethanol was 83.3% of the theoretical maximum.
Molecular analysis of bcl‐1/IgH junctional sequences in mantle cell lymphoma: potential mechanism of the t(11;14) chromosomal translocation
Authors: Stamatopoulos Kostas , Kosmas Christos , Belessi Chrysoula , Kyriazopoulos Panagiotis , Papadaki Theodora , Anagnostou Dimitra , Loukopoulos Dimitris 
Published: March 2005

Mantle cell lymphoma (MCL) is characterized by the t(11;14) translocation that juxtaposes the bcl‐1 locus to immunoglobulin (Ig) gene sequences and leads to deregulation of cyclin D1 gene. t(11;14) is thought to result from an error of the recombinase during D‐JH Ig gene assembly; however, data on the underlying mechanism and candidate recombination‐targeting motifs in the major translocation cluster (MTC) of the bcl‐1 gene are lacking.bcl‐1/IgH junctional sequences from seven MCL patients were amplified by PCR using primers targeting MTC and JH sequences on chromosomes 11q13 and 14q32, respectively. PCR products were directly sequenced and junctional sequences were searched for homology to known germline D genes. bcl‐t MTC breakpoints were searched for the presence of possible recombination target motifs; heptamers, nonamers, binding sequence of the bp45 nuclease, x‐like sequences and D gene segments.bcl‐1/JH junctions were found to bear homology to D gene segments (DLR3, DM and DIR5) in 3/7 MCL samples. A computer‐based search in previously published and/or submitted to GenBank bcl‐1/JH junctional sequences identified homology to D genes in 1/4 MCL tumour samples and 1/4 MCl cell lines; DXP4 or D23/7 and DHQ52 or D22/21 or DXP5, respectively. The MTC locus contained motifs with homology to bp45 nuclease binding sequence, x‐like sequences, heptamers/nonamers, D‐like DIR genes and non‐homologous recombination short (6 bp) DNA sequences.The above data indicate that the t(11;14) translocation in MCL may also occur at a more mature stage of B‐cell ontogeny than previously thought, i.e. during VH‐to‐DJH rearrangement. Various known recombination motifs within MTC may contribute to an illegitimate recombination event between bcl‐1 and DJH.
Characterizing CD43 expression in haematogones using multicolor flow cytometric analysis
Authors: Tsao Lawrence , Colovai Adriana I. , Jiang Jie‐Gen , Bhagat Govind , Alobeid Bachir 
Published: March 2005

SummaryHaematogones are precursor B cells commonly detected in small numbers in the bone marrow. Morphologically, haematogones can mimic lymphoblasts and are best distinguished using multicolour flow cytometry with antibody combinations. Haematogones show characteristic and reproducible patterns of antigen expression representing the B‐cell maturation sequence. CD43 expression, widely seen in haematopoietic elements, has not been well characterized in haematogones. We demonstrate that CD43 is consistently expressed in haematogones in a reproducible pattern similar to that of CD10 when combined with CD20. We propose that in combination with other markers, CD43 can be useful in the identification of haematogones.
Requirement for myeloid growth factors in the differentiation of acute promyelocytic leukaemia
Authors: Matsui William , Douglas Smith B. , Vala Milada , Beal Nikeshia , Huff Carol Ann , Diehl Louis F. , Jones Richard J. 
Published: March 2005

SummaryIt is well known that the differentiation of acute promyelocytic leukaemia (APL) cells by all‐trans‐retinoic acid (ATRA) may be enhanced by myeloid growth factors, but the requirement for growth factors in this process is unclear. Our previous studies in multiple myeloma and non‐APL acute myeloid leukaemia demonstrated that lineage‐specific growth factors are required for the maximal activity of many pharmacologic differentiating agents in vitro. Thus, we studied whether the differentiation of APL is similarly dependent on growth factors. We found that the myeloid growth factors granulocyte colony‐stimulating factor or granulocyte‐macrophage colony‐stimulating factor markedly increased the differentiation of NB4 cells or APL blasts from clinical samples treated with ATRA, arsenic trioxide (ATO), or bryostatin‐1 as evidenced by the enhanced expression of myeloid surface antigens and the inhibition of clonogenic growth. Furthermore, myeloid growth factors were necessary for the differentiation of APL cells since the activity of each pharmacologic agent could be blocked by specific growth factor‐neutralizing antibodies. Each differentiating agent was active only at concentrations that inhibited cell cycling, suggesting that this property is also required for differentiation. These data demonstrate that both pharmacologic differentiating agents and myeloid growth factors are required, but neither sufficient, for the differentiation of APL cells. The combined use of pharmacologic differentiating agents and growth factors may improve the clinical efficacy of differentiation therapy in APL.
Clocks and the Black Box: Circadian Influences on Gonadotropin‐Releasing Hormone Secretion
Authors: Chappell P. E. 
Published: March 2005

AbstractAlthough the mechanisms underlying hypothalamic surge secretion of gonadotropin‐releasing hormone (GnRH) in rodent models have remained enduring mysteries in the field of neuroendocrinology, the identities of two fundamental constituents are clear. Elevated ovarian oestrogen, in conjunction with circadian signals, combine to elicit GnRH surges that are confined to the afternoon of the proestrus phase. The phenomenon of oestrogen positive feedback, although extensively investigated, is not completely understood, and may involve the actions of this steroid directly on GnRH perikarya, as well as on the activity of neuronal afferents. Additionally, whereas many studies have focused upon regulation of GnRH surge secretion by the neuroanatomical biological clock, the suprachiasmatic nucleus, it remains unclear why this daily signal is capable of stimulating surges only in the presence of oestrogen. This review re‐examines multiple models of circadian control of reproductive neurosecretion, armed with the recent characterisation of the intracellular transcriptional feedback loops that comprise the circadian clock, and attempts to evaluate previous studies on this topic within the context of these new discoveries. Recent advances reveal the presence of oscillating circadian clocks throughout the central nervous system and periphery, including the anterior pituitary and hypothalamus, raising the possibility that synchrony between multiple cellular clocks may be involved in GnRH surge generation. Current studies are reviewed that demonstrate the necessity of functional clock oscillations in generating GnRH pulsatile secretion in vitro, suggesting that a GnRH‐specific intracellular circadian clock may underlie GnRH surges as well. Multiple possible steroidal and neuronal contributions to GnRH surge generation are discussed, in addition to how these signals of disparate origin may be integrated at the cellular level to initiate this crucial reproductive event.
Tuberculosis verrucosa cutis: antitubercular therapy, a well‐conceived diagnostic criterion
Authors: Sehgal Virendra N. , Sardana Kabir , Bajaj Promila , Bhattacharya Sambit N. 
Published: March 2005

A 39‐year‐old housewife sustained inadvertent trauma to the right index finger about 6 years ago, whilst stitching clothes. A couple of weeks later, the site of trauma became hard and gritty. Ever since, it has progressed slowly, without any appreciable outward sign. It was not associated with any discomfort/pain. Consequent on an opinion from a surgeon, it was decided to operate on the right index finger. During the operation, under local anesthesia, a hard and gritty material was removed. The material was subjected to histopathologic study. Several stitches were applied to the wound. It failed to respond to antimicrobial therapy over a 4‐week period, prompting the patient to seek another opinion. Examination of the skin surface revealed a plaque with an irregular configuration on and around the distal interphalangeal joint of the right index finger. It was erythematous and pigmented. The top of the plaque was irregular and had alternating elevations and depressions (Fig. 1). Diascopy was negative for apple jelly nodule. A bacillus Calmette–Guérin (BCG) vaccination scar was identified on the left deltoid. There was no regional lymphadenopathy or systemic abnormality. Mantoux test with intradermal injection of 0.1 mL SPAN's tuberculin (purified protein derivative/5 tuberculin units/0.1 mL) (Span Diagnostic Ltd., Murat, India) was negative after 72 h. Investigations, including total and differential leukocyte count, erythrocyte sedimentation rate, serum biochemistry, and renal and liver function tests, were within the normal range, as was a chest X‐ray.Tuberculosis verrucosa cutis before (a) and after (b) antitubercular therapy (ATT)imageHematoxylin and eosin‐stained sections prepared from the biopsy taken from the lesion revealed noteworthy changes in the epidermis and the dermis. The former was marked by the presence of hyperkeratosis, acanthosis, and papillomatosis, whilst the latter contained tubercle granulomas. Each of the granulomas was well formed and consisted of large numbers of lymphocytes, histiocytes, and foreign body (Langerhans’) giant cells (Fig. 2). Caseation necrosis and acid‐fast bacilli could not be demonstrated. The preceding revelations were fairly conducive to the diagnosis. Accordingly, antitubercular therapy (ATT), comprising 450 mg of rifampicin, 300 mg of isonicotinic acid hydrazide, and 800 mg of ethambutol, was recommended for oral administration each day for 60 days. The outcome of the treatment was satisfactory, resulting in perceptible regression of the skin lesion (Fig. 1b). The patient was advised to continue the treatment for another 30 days, after which 450 mg of rifampicin and 300 mg of isonicotinic acid hydrazide were to be continued for another 6 months.Tuberculosis verrucosa cutis depicting well‐formed tubercle(s) comprising lymphocytes, histiocytes, neutrophils, and a few giant cells (hematoxylin and eosin, × 100)image
RECENT ADVANCES IN INTERNATIONAL FINANCE: INTRODUCTION
Authors: Cheung Yin‐Wong 
Published: March 2005

Abstract.Arguably, international finance is one of the most exciting areas in economics. The development of international finance is influenced and shaped, at least in part, by the continuing process of globalization and integration. In the last 25 years the profession has witnessed the proliferation of both theoretical models and empirical analyses in international finance. The analysis of both new and existing issues has benefited from increasingly elaborate modelling techniques and sophisticated empirical tools.
Factors associated with virological response in HIV‐infected patients failing antiretroviral therapy: a prospective cohort study
Authors: Fournier S , Chaffaut C , Maillard A , Loze B , Lascoux C , Gérard L , Timsit J , David F , Bergmann J‐F , Oksenhendler E , Sereni D , Chevret S , Molina J‐M 
Published: March 2005

ObjectivesTo assess the antiviral response to optimized therapy following genotypic resistance testing and to identify factors associated with virological response in HIV‐1‐infected patients failing antiretroviral therapy.MethodsA prospective cohort study was conducted in 344 HIV‐1‐infected patients who underwent genotypic resistance testing because of virological failure. Virological response was defined as a plasma HIV RNA level below 200 HIV‐1 RNA copies/mL or a drop of plasma viral load from baseline of more than 1 log10. A multivariate logistic regression analysis was performed to identify factors associated with virological response.ResultsThe median age of the patients was 40 years, with a male to female ratio of 4:1. Fifty‐one per cent of patients had received the three major classes of antiretrovirals and the median duration of previous antiretroviral therapy was 4.6 years. At baseline, the median plasma HIV RNA level was 4.4 log10 copies/mL and the median CD4 cell count was 274 cells/μL. At 3 months, 55% of patients (188 of 344) had a virological response, which was sustained at 6 months (53%). Predictors of virological response were exposure to two or fewer protease inhibitors [odds ratio (OR) 1.8; P=0.046], and use in optimized therapy of a new class of antiretrovirals (OR 2.9; P=0.006), of more than two new drugs (OR 3.0; P<0.0001), of abacavir (OR 1.9; P=0.03), or of lopinavir/ritonavir (OR 3.7; P=0.0002).ConclusionsA high proportion of patients achieved a short‐term virological response in this cohort study. Patients with the least experience of protease inhibitor treatment and in whom a new class of antiretroviral, more than two new drugs, abacavir or lopinavir/ritonavir was used in optimized therapy had the best virological outcome.
Prevalence of pervasive developmental disorders in children and adolescents with mental retardation
Authors: De Bildt Annelies , Sytema Sjoerd , Kraijer Dirk , Minderaa Ruud 
Published: March 2005

Background:  Insight into the prevalence of pervasive developmental disorder (PDD) in children and adolescents with mental retardation (MR) is known to be of clinical importance. However, estimating this prevalence is complicated. The literature reports prevalence rates ranging from 3% through 50%. This variation seems to be related to the concepts of PDD under study, the instruments used, and the studied populations. The present study aimed to estimate a reliable prevalence rate of PDD.Methods:  A total population‐based screening with the PDD‐MRS and the ABC (n = 825) was followed by further assessment of children and adolescents at high risk for PDD according to these instruments, and for controls, with the ADI‐R, ADOS‐G and a DSM‐IV‐TR classification (n = 188).Results:  The instruments lead to different prevalence rates that range from 7.8% to 19.8%. The differences in the estimated prevalence rates are related to the concept of PDD and the instruments they represent. The DSM‐IV‐TR prevalence (16.7%) seems to be the most reliable and well‐founded estimate, since this prevalence rate is based on information from multiple informants and multiple time periods.Conclusions:  The reported prevalence rates provide policy makers with an up‐to‐date and more substantiated guideline for the allocation of resources for children and adolescents with MR and PDD. The height of the prevalence should alert professionals that PDD is widespread in the population with MR.