bluuebunny/crossref_metadata_2025_split huggingface dataset:
NK‐active cytokines IL‐2, IL‐12, and IL‐15 selectively modulate specific protein kinase C (PKC) isoforms in primary human NK cells
Authors: Vitale Marco , Bassini Alessandra , Secchiero Paola , Mirandola Prisco , Ponti Cristina , Zamai Loris , Mariani Adriana R. , Falconi Mirella , Azzali Giacomo 
Published: October 2004

AbstractNatural killer (NK) cell function is largely modulated by growth factors and cytokines. In particular, interleukin (IL)‐2, IL‐12, and IL‐15 have major effects on the proliferative and cytotoxic activities of NK cells against tumor and virus‐infected cells. It is thought that the members of the protein kinase C (PKC) family of serine/threonine kinases play an important role in mediating the pleiotropic effects of cytokines on their target cells. We have investigated the downstream effects generated in purified human NK cells by IL‐2, IL‐12, and IL‐15 on PKCα and PKCϵ—a canonical and a novel isoform of PKC, respectively. By means of Western blotting, PKC activity assays, and immunofluorescence performed on highly purified preparations of primary human NK cells, we demonstrate that: 1) the three cytokines have similar effects on PKCα and PKCϵ activities; 2) whereas PKCϵ activity is induced by cytokine stimulation, PKCα activity is inhibited; and 3) both the induction of PKCϵ and the inhibition of PKCα functional activity are relatively early events in NK cells, while longer cytokine stimulations do not generate significant variations in enzyme activity, suggesting that the activation of both the canonical and novel isoforms of PKC are events required in the early phases of cytokine‐induced NK cell stimulation. Anat Rec 266:87–92, 2002. © 2002 Wiley‐Liss, Inc.
Functional anatomy of the deer spine: An appropriate biomechanical model for the human spine?
Authors: Kumar Naresh , Kukreti Sandeep , Ishaque Mushtaque , Sengupta Dilip K. , Mulholland Robert C. 
Published: October 2004

AbstractThe object of this study was to create a database for the biomechanical and certain functional anatomical parameters of the deer spine, for comparison with the human spine. This was done with a view toward using the deer spine as an alternative model for various biomechanical experiments, as it is difficult to procure nonembalmed, fresh human spine specimens. Bovine spongiform encephalopathy (BSE) and its human variant, Creutzfeld Jakob disease (CJD), prevent us from using bovine and sheep spine. There is a risk of transmission of disease through direct inoculation to the researcher working with infected bovine or sheep spine, and a theoretical possibility of transmission through the food chain if proper precautions for specimen disposal are not taken. We chose deer spine as an alternative for testing nonembalmed fresh human spine because, to date, there have been no reported cases of deer being carriers of prion diseases. Fifteen deer spine specimens were sectioned appropriately to obtain six functional spinal units for each level in the thoracic and lumbar spine. Each unit was tested in a Dartec materials testing machine (Dartec Ltd., Stourbridge, UK) under pure moments in three main anatomical planes. The range of motion (ROM), neutral zone (NZ), and stiffness parameters of the functional unit were determined in flexion‐extension, right/left lateral bending, and axial rotation. The data obtained were compared with the corresponding human spine data in the literature. Deer spine specimens were also studied for bone mineral density (BMD) using a DEXA scan. The results revealed the overall ROM was greater for deer spine compared to the human spine in the upper thoracic region, but less compared to human spine in the lower lumbar spine region. The only comparable region for ROM was in the lower thoracic/upper lumbar region. The stiffness coefficients were also comparable in this region. The BMD was also comparable in the two species. We conclude that the lower thoracic/upper lumbar region in the deer spine can be used as a model for some human biomechanical experiments because of its biomechanical and material similarities to the human spine of the corresponding region. Anat Rec 266:108–117, 2002. © 2002 Wiley‐Liss, Inc.
Transforming growth factor‐beta 3(Tgf‐β3) in a collagen gel delays fusion of the rat posterior interfrontal suture in vivo
Authors: Opperman Lynne A. , Moursi Amr M. , Sayne Jennifer R. , Wintergerst Ana Maria 
Published: October 2004

AbstractPostnatal expansion of the intramembranous bones of the craniofacial skeleton occurs as bone growth at sutures. Loss of the bone growth site occurs when the suture fails to form, or when the newly formed sutures become ossified, resulting in premature obliteration. Previous experiments demonstrated that removal of dura mater from fetal rat coronal sutures, or neutralizing transforming growth factor‐beta 2 (Tgf‐β2) activity using antibodies resulted in premature obliteration of the suture in vitro. Conversely, addition of Tgf‐β3 to coronal sutures in vitro rescued them from osseous obliteration. To examine whether Tgf‐β3 rescues sutures from obliteration in vivo, a collagen gel was used as a vehicle to deliver Tgf‐β3 to the normally fusing rat posterior interfrontal (IF) suture. Surgery was done on postnatal day 9 (P9) rats, in which collagen gels containing 0, 3, or 30 ng Tgf‐β3 were placed above the IF suture, underneath the periosteum for 2 weeks. By P24, 75–100% of animals in control unoperated, sham‐operated, and collagen gel‐only groups had fused IF sutures. In contrast, 40% of sutures exposed to 3 ng Tgf‐β3 remained open, while sutures exposed to 30 ng Tgf‐β were similar to controls. By immunohistochemistry, sutures rescued from obliteration by Tgf‐β3 had the same Tgf‐β receptor type II (Tβr‐II) distribution as controls. However, Tgf‐β3‐treated sutures had altered Tgf‐β2 and Tβr‐I distribution compared to controls. Anat Rec 267:120–130, 2002. © 2002 Wiley‐Liss, Inc.
Circumferential variation in human second metacarpal cortical thickness: Sex, age, and mechanical factors
Authors: Lazenby Richard A. 
Published: October 2004

AbstractVariation in cortical thickness (CT) in four quadrants of the human second metacarpal was investigated in a sample (100 males and 72 females, skeletal age 20 to 50+ years) from a 19th‐century cemetery. Both left and right elements were studied (total N = 344). Multivariate analysis of covariance (MANCOVA) (for age, sex, and side, controlling for absolute size) was used to test the hypothesis of equality of thickness in the dorsal, palmar, medial, and lateral quadrants. Differences in regional CT posits localized regulation of resorption and formation adapting bone shape to functional loads, with implications for activity‐modulation of skeletal senescence. The palmar cortex was found to be uniformly thicker in both sexes and both sides, and at all ages (young, middle, and old adult); the medial, lateral, and dorsal cortices did not differ significantly. Patterns of age‐related loss occurring preferentially at the endocortical surface differed between men and women, with women showing significant declines across all age groups for all quadrants, and males only small decrements after middle age. The greater CT in the palmar quadrant corresponds to the region of maximum compressive strain in the second metacarpal for functions involving full flexion (grasping). Although the palmar cortex is thicker at all ages, women lose mass in that quadrant at the same rate as in other quadrants, suggesting that function does not offer protection against endocrinologically‐mediated depletion of bone mass (postmenopausal osteopenia). Anat Rec 267:154–158, 2002. © 2002 Wiley‐Liss, Inc.
Patients' perceptions of the effects of systemic lupus erythematosus on health, function, income, and interpersonal relationships: A comparison with Wegener's granulomatosis
Authors: Boomsma Maarten M. , Bijl Marc , Stegeman Coen A. , Kallenberg Cees G. M. , Hoffman Gary S. , Tervaert Jan Willem Cohen 
Published: October 2004

AbstractObjectiveTo describe the patients' perceptions of the effects of systemic lupus erythematosus (SLE) and Wegener's granulomatosis (WG) on health, function, income, and interpersonal relationships.Methods114 patients with SLE, and 79 patients with WG completed a self‐administered questionnaire. Patients had been diagnosed with SLE or WG for a median period of 10 and 5 years, respectively.ResultsAll patients experienced substantial functional morbidity. Two‐thirds of the patients with SLE or WG reported either a periodic or permanent inability to perform daily activities at home and/or at work. Furthermore, SLE as well as WG had a considerable impact upon the psychological and social life, affecting their happiness and altering relationships.ConclusionOur study demonstrates that SLE and WG are associated with substantial medical morbidity resulting in physical and occupational disability. SLE has a profound impact on patients' lives, similar to that experienced in patients with WG.
Molecular biology of Fanconi anaemia—an old problem, a new insight
Authors: Ahmad Shamim I. , Hanaoka Fumio , Kirk Sandra H. 
Published: October 2004

AbstractFanconi anaemia (FA) comprises a group of autosomal recessive disorders resulting from mutations in one of eight genes (FANCA, FANCB, FANCC, FANCD1, FANCD2, FANCE, FANCF and FANCG). Although caused by relatively simple mutations, the disease shows a complex phenotype, with a variety of features including developmental abnormalities and ultimately severe anaemia and/or leukemia leading to death in the mid teens. Since 1992 all but two of the genes have been identified, and molecular analysis of their products has revealed a complex mode of action. Many of the proteins form a nuclear multisubunit complex that appears to be involved in the repair of double‐strand DNA breaks. Additionally, at least one of the proteins, FANCC, influences apoptotic pathways in response to oxidative damage. Further analysis of the FANC proteins will provide vital information on normal cell responses to damage and allow therapeutic strategies to be developed that will hopefully supplant bone marrow transplantation. BioEssays 24:439–448, 2002. © 2002 Wiley Periodicals, Inc.
Hydrodynamic properties of rigid macromolecules composed of ellipsoidal and cylindrical subunits
Authors: García de la Torre J. , Carrasco B. 
Published: October 2004

AbstractA procedure is devised for the calculation of hydrodynamic properties of rigid macromolecules composed subunits that are modeled as ellipsoids of revolution and cylinders. Owing to the axial symmetry of these shapes, smooth shell models can be constructured for the subunit structure. The bead shell model so constructed is employed for the calculation of the properties. A computer program, HYDROSUB, has been written implementing both the model building and the hydrodynamic calculation. A detailed example of the use of this methodology is presented for the case of the solution properties of the human antibody molecule immunoglobulin G3 (IgG3). Finally, hints are given on other uses and applications of the procedure. © 2002 John Wiley & Sons, Inc. Biopolymers 63: 163–167, 2002; DOI 10.1002/bip.10013
Molecular dynamics calculations on amylose fragments. I. Glass transition temperatures of maltodecaose at 1, 5, 10, and 15.8% hydration
Authors: Momany Frank A. , Willett J. L. 
Published: October 2004

AbstractMolecular dynamics simulations (NPT ensembles, 1 atm) using the all atom force field AMB99C (F. A. Momany and J. L. Willett, Carbohydrate Research, Vol. 326, pp 194–209 and 210–226), are applied to a periodic cell containing ten maltodecaose fragments and TIP3P water molecules. Simulations were carried out at 25 K intervals over a range of temperatures above and below the expected glass transition temperature, Tg, for different water concentrations. The amorphous cell was constructed through successive dynamic equilibration steps at temperatures above Tg and the temperature lowered until several points of reduced slope (1/T vs volume) were obtained. This procedure was carried out at each hydration level. Each dynamics simulation was continued until the volume remained constant without up or down drift for at least the last 100 ps. For a given temperature, most simulations required 400–600 ps to reach an equilibrium state, but longer times were necessary as the amount of water in the cell was reduced. A total of more than 30 ns of simulations were required for the complete study. The Tg for each hydrated cell was taken as that point at which a discontinuity in slope of the volume (V), potential energy (PE), or density (ρ) vs 1/T was observed. The average calculated Tg values were 311, 337, 386, and 477 K for hydration levels of 15.8, 10, 5, and 1%, respectively, in generally good agreement with experimental values. The Tg for anhydrous amylose is above the decomposition temperature for carbohydrates and so cannot be easily measured. However, it has also been difficult to obtain a value of Tg for anhydrous amylose using simulation methods. Other molecular parameters such as end‐to‐end distances, mean square distributions, and pair distributions are discussed. Published 2002 John Wiley & Sons, Inc. Biopolymers 63: 99–110, 2002
A molecular dynamics study of the stoichiometric complex formed by poly (α, L‐glutamate) and octyltrimethylammonium ions in chloroform solution
Authors: Zanuy David , Alemán Carlos , Muñoz‐Guerra Sebastián 
Published: October 2004

AbstractWe present a molecular dynamics simulation at 300 K in explicit solvent environment of chloroform of the stoichiometric complex formed by poly(α,L‐glutamate) and octyltrimethylammonium ions. We observed that the α‐helix conformation of the polypeptide chain remains stable during a 2‐ns run. The surfactant ions predominantly adopted an extended conformation that is stabilized by favorable interactions with the organic solvent. Analysis of the organization of the surfactant with respect to the polypeptide chain indicated that each octyltrimethylammonium cation was preferentially bound to more than one carboxylate group. It was found that the most populated arrangement was that with the surfactant cations interacting with two carboxylate groups simultaneously. © 2002 John Wiley & Sons, Inc. Biopolymers 63: 151–162, 2002; DOI 10.1002/bip.10016
Mode of action of recombinant Azotobacter vinelandii mannuronan C‐5 epimerases AlgE2 and AlgE4
Authors: Hartmann Martin , Holm Olav B. , Johansen Gunn A. B. , Skjåk‐Bræk Gudmund , Stokke Bjørn T. 
Published: October 2004

AbstractThe enzymes mannuronan C‐5 epimerases catalyze conversion of β‐D‐mannuronic acid to α‐L‐guluronic acid in alginates at the polymer level and thereby introduce sequences that have functional properties relevant to gelation. The enzymatic conversion by recombinant mannuronan C‐5 epimerases AlgE4 and AlgE2 on alginate type substrates with different degree of polymerization and initial low fraction of α‐L‐guluronic acid was investigated. Essentially no enzymatic activity was found for fractionated mannuronan oligomer substrates with an average degree of polymerization, DPn, less than or equal 6, whereas increasing the DPn yielded increased epimerization activity. This indicates that these enzymes have an active site consisting of binding domains for consecutive residues that requires interaction with 7 or more consecutive residues to show enzymatic activity. The experimentally determined kinetics of the reaction, and the residue sequence arrangement introduced by the epimerization, were modeled using Monte Carlo simulation accounting for the various competing intrachain substrates and assuming either a processive mode of action or preferred attack. The comparison between experimental data and simulation results suggests that epimerization by AlgE4 is best described by a processive mode of action, whereas the mode of action of AlgE2 appears to be more difficult to determine. © 2002 John Wiley & Sons, Inc. Biopolymers 63: 77–88, 2002
Vibrational coupling as diagnostic for intramolecular hydrogen bonds of carbohydrates in aqueous solution
Authors: Carmona Pedro , Molina M. , Aboitiz N. , Vicent C. 
Published: October 2004

AbstractThe coupling of νCO and δOD vibrations in the 1200–900 cm−1 IR range leads to band shifting in opposite directions, which provides information on intramolecular hydrogen bonding of carbohydrates in aqueous solution. The aqueous solution IR spectra of 2‐acetamide‐1,6‐anhydro‐2‐deoxy‐D‐glucopyranose and cis‐1,2‐cyclopentanediol and tetrahydrofuran–ethanol mixtures are reported. Frequency upshifting upon deuteration is observed for the νCO bands of both a hydrogen bond acceptor and donor in ether–hydroxyl and hydroxyl–hydroxyl contacts. The 1200–900 cm−1 range can be used to reveal the presence of intramolecular hydrogen bonds in aqueous carbohydrates, unlike the OH stretching region, which cannot be used in this sense due to carbohydrate band masking by the strong νOH IR absorption of water. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 20–25, 2002; DOI 10.1002/bip.10024
Characterization of dioxygenated cobalt(II)–carnosine complexes by Raman and IR spectroscopy
Authors: Torreggiani A. , Taddei P. , Fini G. 
Published: October 2004

AbstractRaman and IR studies are carried out on carnosine (β‐alanyl‐L‐histidine, Carnos) and its complexes with cobalt(II) at different metal/ligand ratios and basic pH. Binuclear complexes that bind molecular oxygen are formed and information regarding the OO bridge is obtained from the Raman spectra. When the Co(II)/Carnos ratio is ≤1, peroxobinuclear complexes are the predominant species and two forms (monobridged and dibridged) are identified by the presence of two Raman peaks in the νOO region (750–850 cm−1). These peroxo complexes can be oxidized to yield a superoxo complex when the metal slightly exceeds the Carnos concentration, and there are consequent shifts of the νOO band to higher wavenumbers. In addition, the chelated species in the 2 : 1 Co(II)/Carnos system is found to bind oxygen to a lesser degree. With respect to the coordination sites, each Co(II) ion of the binuclear dioxygenated complexes is bound to one oxygen atom and four nitrogen atoms: Nπ and Nτ of two Carnos molecules, the peptide, and the terminal amino nitrogen atoms. Conversely, when the metal/ligand ratio is 2, in addition to the dioxygenated complexes, a complex is formed in which the imidazole moiety of Carnos binds two different cobalt ions because the Nπ and Nτ nitrogens are both deprotonated. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 70–81, 2002; DOI 10.1002/bip.10025
Changes in protein conformation and dynamics upon complex formation of brain‐derived neurotrophic factor and its receptor: Investigation by isotope‐edited Fourier transform IR spectroscopy
Authors: Li Tiansheng , Talvenheimo Jane , Zeni Lisa , Rosenfeld Robert , Stearns George , Arakawa Tsutomu 
Published: October 2004

AbstractThe interactions of brain‐derived neurotrophic factor (BDNF) with the extracellular domain of its receptor (trkB) are investigated by employing isotope‐edited Fourier transform IR (FTIR) spectroscopy. The protein secondary structures of individual BDNF and trkB in solutions are compared with those in their complex. The temperature dependence of the secondary structures of BDNF, trkB, and their complex is also investigated. Consistent with the crystal structure, we observe by FTIR spectroscopy that BDNF in solution contains predominantly β strands (∼53%) and relatively low contents of other secondary structures including β turns (∼16%), disordered structures (∼12%), and loops (∼18%) and is deficient in α helix. We also observe that trkB in solution contains mostly β strands (52%) and little α helix. Conformational changes in both BDNF and trkB are observed upon complex formation. Specifically, upon binding of BDNF, the conformational changes in trkB appear to involve mostly β turns and disordered structures while the majority of the β‐strand conformation remains unchanged. The IR data indicate that some of the disordered structures in the loop regions are likely converted to β strands upon complex formation. The FTIR spectral data of BDNF, trkB, and their complex indicate that more amide NH groups of trkB undergo H–D exchange within the complex than those of the ligand‐free receptor and that the thermal stability of trkB is decreased slightly upon binding of BDNF. The FT‐Raman spectra of BDNF, trkB, and their complex show that the six intramolecular disulfide bonds of trkB undergo significant conformational changes upon binding of BDNF as a result of changes in the tertiary structure of trkB. Taken together, the FTIR and Raman data are consistent with the loosening of the tertiary structure of trkB upon binding of BDNF, which leads to more solvent exposure of the amide NH group and decreased thermal stability of trkB. This finding reveals an intriguing structural property of the neurotrophin ligand–receptor complex that is in contrast to other ligand–receptor complexes such as a cytokine–receptor complex that usually shows protection of the amide NH group and increased thermal stability upon complex formation. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 10–19, 2002; DOI 10.1002/bip.10038
Physical properties of compounds promoting oral delivery of macromolecular drugs
Authors: Desamero Ruel Z. B. , Cheng Hu , Cahill Sean , Girvin Mark , Deng Hua , Callender Robert , Rath Parshuram , Variano Bruce , Smart John E. 
Published: October 2004

AbstractThe spectroscopic and solution properties of a series of amidated acids (delivery agents), which promote the gastrointestinal absorption of USP heparin and other drugs that show poor oral bioavailability, are investigated using Raman and NMR spectroscopy. The results show evidence for self‐association at low concentrations of delivery agents that increases as the concentration of the delivery agent is increased. The self‐associate is characterized by ring–ring stacking interactions, and the best geometrical arrangement for the stacking is the parallel‐shifted arrangement of the rings. In addition, the amide group participates in the formation of intermolecular hydrogen bonds in the self‐associate. Unlike the rigid ring, the tails of these delivery agents remain relatively flexible in the self‐associate. It is suggested that the limited solubility of the delivery agents at physiological pH arises from a percentage of protonated carboxyls. Their presence promotes the formation of intermolecular hydrophobic and ring stacking interactions, which are otherwise weakened by an ionized carboxyl group. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 26–40, 2002; DOI 10.1002/bip.10039
Interactions of amidated acids with heparin
Authors: Desamero Ruel Z. B. , Cheng Hu , Cahill Sean , Girvin Mark , Deng Hua , Callender Robert , Rath Parshuram , Variano Bruce , Smart John E. 
Published: October 2004

AbstractRaman and NMR studies are performed to characterize the solution structures of complexes between heparin and a group of amidated acids, which act as delivery agents that facilitate the gastrointestinal absorption of orally administered heparin. At concentrations typically employed for the oral drug delivery of heparin, the contact points between heparin complexed with the delivery agents include points near the OH groups of heparin. The results suggest that heparin interacts rather nonspecifically with the amidated acids as monomers and with self‐associated complexes of the delivery agents. It is also found that the carboxyl groups of at least one of the bioactive delivery agents easily protonates when it forms complexes with itself or heparin. This attribute may be one reason why this class of compounds is effective in the oral delivery of heparin. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 41–48, 2002; DOI 10.1002/bip.10040