bluuebunny/crossref_metadata_2025 huggingface dataset:
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

The 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

The 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

Raman 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

The 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

The 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

Raman 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
Analysis of mebendazole polymorphs by Fourier transform IR spectrometry using chemometric methods
Authors: Aboul‐Enein Hassan Y. , Bunaciu Andrei A. , Fleschin Serban
Published: October 2004

A diffuse reflectance IR Fourier transform IR spectrometry (DRIFTS) method was developed for the rapid, direct measurement of mebendazole in drugs. Conventional KBr spectra and DRIFTS spectra were compared for the best determination of the active substance in the drug formulations. Two chemometric approaches were used in the data processing: multicomponent partial least squares (PLS2) and principal component regression. The best results were obtained with the PLS2 method. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 56–60, 2002; DOI 10.1002/bip.10041
Circular dichroism study of interactions of Fungizone or AmBisome forms of amphotericin B with human low density lipoproteins
Authors: Barwicz Joanna , Beauregard Marc , Tancrède Pierre
Published: October 2004

Amphotericin B (AmB), a potent antifungal agent used to treat invasive fungal infections, is still employed more than 40 years after its introduction in the pharmacopea. When injected into the blood stream, this antibiotic is carried by low density lipoproteins (LDLs) to which it induces the formation of oxidation products responsible in part for some of the severe adverse effects of the drug. However, the oxidative damages induced to LDLs are not yet understood. We present here the effects of the Fungizone and AmBisome forms of AmB on LDLs as compared to those of CuSO4, a well‐known powerful oxidant of LDLs. We use circular dichroism (CD) spectroscopy, which is particularly useful because it allows the investigation of the structural integrity of the proteic moiety of LDL upon interaction with AmB. The CD spectra also yield information on the drug itself because in its oligomer form it presents a strong dichroic signal in a spectral region different from that of the protein. Our results show that neither form of AmB changes the secondary structure of the protein while the helical content of the LDL is increased either in the presence of CuSO4 alone or in the presence of CuSO4 and AmBisome or Fungizone. On the other hand, the CD spectra of the antibiotic indicate that Fungizone AmB suffers important oxidative damage in the presence of LDLs and CuSO4 while this damage is not present with AmBisome AmB. These observations lead us to propose that the structural modifications of the proteic part of LDLs induced by the Cu2+ ions are involved in the important oxidative damage suffered by Fungizone AmB, which in this form is much more susceptible to interaction with its environment than AmBisome. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 49–55, 2002; DOI 10.1002/bip.10042
Spectroscopic studies and PM3 semiempirical calculations of Schiff bases of gossypol with L‐amino acid methyl esters
Authors: Przybylski Piotr , Brzezinski Bogumil
Published: October 2004

Three Schiff bases of racemic gossypol with L‐amino acid methyl esters are synthesized and studied by FTIR and 1H‐NMR spectroscopy, and their structures are calculated by the PM3 semiempirical method. The Schiff bases in the study exist in the solid state and in solutions as enamine forms. The existence of diastereoisomers is very visible in the 1H‐NMR spectra. The amount of the diastereoisomers depends on the amount of time the solutions are rested in diffused light. The epimerization from D,L‐isomer to L,L‐isomer is very slow. The structures of the Schiff bases and the hydrogen bonds within these structures are discussed. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 61–69, 2002; DOI 10.1002/bip.10043
Interaction between Btk TH and SH3 domain
Authors: Okoh Michael P. , Vihinen Mauno
Published: October 2004

Several mechanisms are involved in the regulation of cellular signaling. Bruton tyrosine kinase (Btk) of the Tec family contains in the Tec homology (TH) domain a proline‐rich region (PRR) capable of interacting with several SH3 domains. The Btk has the SH3 domain adjacent to the TH domain. CD and fluorescence spectroscopy were used to study the binding of two peptides corresponding to segments in the PRR to the Btk SH3 domain. The peptide for the N‐terminal half of the PRR binds specifically, whereas the other peptide had hardly any affinity. The TH domain has about four times lower affinity to the SH3 domain than the peptide, 17.0 vs 3.9 μM. The interaction was further tested with an SH3 domain construct that contained the PRR. The two peptides cannot compete for the binding to the extended protein and the TH domain has two times lower affinity to the extended SH3 domain. The intra‐ or intermolecular interaction between the TH and SH3 domain might have regulatory function also in the other Tec family members. © 2002 Wiley Periodicals, Inc. Biopolymers 63: 325–334, 2002
Fourier transform‐Raman spectroscopic study of natural resins of archaeological interest
Authors: Brody Rachel H. , Edwards Howell G. M. , Pollard A. Mark
Published: October 2004

Resins from several different genera are studied using Fourier transform (FT)‐Raman spectroscopy. Tree resins can be broadly divided into those that contain diterpenoid components and those that contain triterpenoid components. The diterpenoid resins analyzed are from the genera Pinus, Cedrus, and Agathis (kauri resin) and the triterpenoid resins examined are samples from Pistacia, Boswellia (frankincense), and Commiphora (myrrh) genera. A protocol is developed to nondestructively distinguish diterpenoid and triterpenoid resins and to differentiate the genera within the two types. The effects of oxidation on the discrimination of the FT‐Raman spectra are considered. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 129–141, 2002
Medical applications of Raman spectroscopy: From proof of principle to clinical implementation
Authors: Choo‐Smith L.‐P. , Edwards H. G. M. , Endtz H. P. , Kros J. M. , Heule F. , Barr H. , Robinson J. S. , Bruining H. A. , Puppels G. J.
Published: October 2004

Raman spectroscopy has recently been applied ex vivo and in vivo to address various biomedical issues such as the early detection of cancers, monitoring of the effect of various agents on the skin, determination of atherosclerotic plaque composition, and rapid identification of pathogenic microorganisms. This leap in the number of applications and the number of groups active in this field has been facilitated by several technological advancements in lasers, CCD detectors, and fiber‐optic probes. However, most of the studies are still at the proof of concept stage. We present a discussion on the status of the field today, as well as the problems and issues that still need to be resolved to bring this technology to hospital settings (i.e., the medical laboratory, surgical suites, or clinics). Taken from the viewpoint of clinicians and medical analysts, the potential of Raman spectroscopic techniques as new tools for biomedical applications is discussed and a path is proposed for the clinical implementation of these techniques. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 1–9, 2002; DOI 10.1002/bip.10064
Preferred conformations of RGDX tetrapeptides to inhibit the binding of fibrinogen to platelets
Authors: Park Hae Sook , Kim Choonmi , Kang Young Kee
Published: October 2004

The conformational study on Arg–Gly–Asp (RGD)‐containing tetrapeptides in the unhydrated and hydrated states has been carried out using the force field ECEPP/3 and the hydration shell model. The tetrapeptides studied here are H–RGDX–OH (X = Trp, Tyr, Phe, Leu, Val, Cys, Gln, and Ser), which show the inhibitory activity for binding of fibrinogen to platelets in the order of RGDW ≈ RGDY ≈ RGDF ≈ RGDL > RGDV ≥ RGDC ≥ RGDQ ≥ RGDS. The backbone conformations with two C7 backbone‐to‐backbone hydrogen bonds between Asp and Arg residues and between Xaa and Gly residues are in common most probable for the RGD sequence of RGDX tetrapeptides in the hydrated state. The dominant β‐turns for RGDX are found to be the types V′ and IV at Gly–Asp and Asp–Xaa sequences, respectively, which are quite similar to the types II′ and I (or II), respectively. However, it cannot be ruled out that the extended conformations are also remarkably feasible for RGDX tetrapeptides in water by peering the distributions of backbone conformations. These calculated results are consistent with the experimental results on RGD‐containing proteins and conformationally constrained RGD‐containing peptides. The reason why the RGDX becomes more potent as the side chain of the X residue is more hydrophobic may be ascribed to that the more hydrophobic is the residue X, the more populated are β‐turn structures for the Gly–Asp sequence. The hydrophobic side chain of X residue exposed to water is likely to interact with the hydrophobic region of receptor easily. © 2002 Wiley Periodicals, Inc. Biopolymers 63: 298–313, 2002
Synthesis, conformational analysis, and spectroscopic characterization of peptides based on Daf, the first rigid transition‐metal receptor, cyclic Cα,α‐disubstituted glycine
Authors: Peggion Cristina , Crisma Marco , Formaggio Fernando , Toniolo Claudio , Wright Karen , Wakselman Michel , Mazaleyrat Jean‐Paul
Published: October 2004

Three series of terminally protected model oligopeptides to the nonamer level, based on 9‐amino‐4,5‐diazafluorene‐9‐carboxylic acid, the first rigid bipyridine‐type Cα,α‐disubstituted glycine, and either Gly, L‐Ala, or Aib residues were synthesized by solution methods and fully characterized. The molecular structures of two derivatives and one tripeptide were determined in the crystal state by x‐ray diffraction. Moreover, the solution preferred conformations of these peptides were assessed by Fourier transform infrared absorption and 1H‐NMR techniques. A comparison with the known structural tendencies of the strictly related Cα,α‐disubstituted glycyl residues 1‐aminocyclopentane‐1‐carboxylic acid and 9‐aminofluorene‐9‐carboxylic acid is made, and the implications for the use of the 9‐amino‐4,5‐diazafluorene‐9‐carboxylic acid residue in conformationally constrained analogs of bioactive peptides are briefly examined. A spectroscopic (uv absorption, fluorescence, CD) characterization of this novel heteroaromatic Cα,α‐disubstituted glycine is also reported. Finally, preliminary conformational data and membrane activity measurements are discussed for an analog of the lipopeptaibol antibiotic [L‐Leu11–OMe] trichogin GA IV in which a 9‐amino‐4,5‐diazafluorene‐9‐carboxylic acid residue was synthetically incorporated in position 1 (replacing the original Aib residue). © 2002 Wiley Periodicals, Inc. Biopolymers 63: 314–324, 2002
Time‐resolved FTIR difference spectroscopy as tool for investigating refolding reactions of ribonuclease T1 synchronized with trans → cis prolyl isomerization
Authors: Moritz Ralf , Reinstädler Diane , Fabian Heinz , Naumann Dieter
Published: October 2004

The structurally well‐characterized enzyme ribonuclease T1 was used as a model protein to further evaluate time‐resolved Fourier transform IR difference spectroscopy in conjunction with temperature‐jump techniques as a useful detection technique for protein folding studies. Compared to the wild‐type protein, it was confirmed that the lack of one cis‐proline bond at position 55 of the S54G/P55N variant is sufficient to significantly simplify and accelerate the refolding process. This result was sustained by the characterization of the early refolding events that occurred within the experimental dead time. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 145–155, 2002
Analysis of peptide rotational diffusion by homonuclear NMR
Authors: Malliavin Thérèse E. , Giudice Emmanuel
Published: October 2004

The analysis of the rotational diffusion of a molecule using homonuclear NMR is investigated. The homonuclear longitudinal and transverse cross‐relaxation rates, which can be quantitatively measured using off‐Resonance Rotating frame nuclear Overhauser Effect Spectroscopy (ROESY), are used to build a distribution, which exhibits a solid‐state‐like pattern characteristic of the diffusion tensor. The distributions of the antimicrobial peptide ranalexin in water and in 30% of trifluoracetic acid (TFE) are compared, and the peptide rotational diffusion is shown to be more isotropic in water than in 30% TFE. This difference is further supported by the analysis of NMR ranalexin conformers in 30% TFE, and by the analysis of a molecular dynamics simulation of peptide in water. © 2002 Wiley Periodicals, Inc. Biopolymers 63: 335–342, 2002
Stability studies of recombinant Saccharomyces cerevisiae in the presence of varying selection pressure
Authors: Gupta Jagdish C. , Mukherjee K. J.
Published: October 2004

A recombinant yeast plasmid carrying the Ieu2 gene for auxotrophic complementation and a reporter gene for β‐galactosidase under the control of Gal10 promoter was studied in Saccharomyces cerevisiae. Growth, product formation, and plasmid stability were studied in defined, semi‐defined, and complex media. The biomass concentration and specific activity were higher in complex medium than in defined medium, which was selective for the growth of plasmid‐containing cells, leading to a 10‐fold increase in volumetric activity. However, plasmid instability was very high in complex media with 50% plasmid‐free cells emerging in the culture within 75 h of cultivation. In order to control instability, the growth rates of the plasmid‐containing and plasmid‐free cells were determined in semi‐defined media, which consisted of defined medium supplemented with different concentrations of yeast extract. Below a critical concentration of yeast extract (0.05 g/L), the plasmid‐containing cells had a growth rate advantage over the plasmid‐free cells. This was possibly because, at this concentration of yeast extract, the availability of leucine became the rate‐determining factor in the specific growth rate of plasmid‐free cells. A feeding strategy was designed which maintained a low concentration of the residual yeast extract in the medium and thus continuously provided the plasmid‐containing cells with a competitive advantage over the plasmid‐free cells. This resulted in high stability as well as high cell density under non‐selective conditions, which led to a 10‐fold increase in the volumetric activity compared to that achieved in defined selective media. A simple mathematical model was formulated to verify the experimental data. The important state variables and process parameters, i.e., biomass concentration, β‐galactosidase expression, sucrose consumption, yeast extract consumption, and specific growth rates of the two cell populations, were evaluated. These variables and parameters along with the differential equations based on material balances as well as the experimental results obtained were used in a mathematical model for the fed‐batch cultivation. These correctly verified the experimental data and clearly illustrated the concept behind the success of the fed‐batch strategy under yeast extract starvation. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 78: 475–488, 2002.
Mechanism of adaptation of an atypical alkaline p‐nitrophenyl phosphatase from the archaeon Halobacterium salinarum at low‐water environments
Authors: Marhuenda‐Egea Frutos C. , Piera‐Velázquez Sonsoles , Cadenas Chiquinquirá , Cadenas Eduardo
Published: October 2004

Enzymes suspended in organic solvents represent a versatile system for studying the involvement of water in catalytic properties and their flexibility in adapting to different environmental conditions. The extremely halophilic alkaline p‐nitrophenylphosphate phosphatase from the archaeon Halobacterium salinarum was solubilized in an organic medium consisting of reversed micelles of hexadecyltrimethylammoniumbromide in cyclohexane, with 1‐butanol as cosurfactant. Hydrolysis of p‐nitrophenylphosphate was nonlinear with time when the enzyme was microinjected into reversed micelles that contained substrate. These data are consistent with a kinetic model in which the enzyme is irreversibly converted from an initial form to a final stable form during the first seconds of the encapsulation process. The model features a rate constant (k) for that transition and separate hydrolysis rates, v1 and v2, for the two forms of the enzyme. The enzyme conversion may be governed by the encapsulation process. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 78: 497–502, 2002.
Microbial synthesis of semiconductor CdS nanoparticles, their characterization, and their use in the fabrication of an ideal diode
Authors: Kowshik Meenal , Deshmukh Neelima , Vogel W. , Urban J. , Kulkarni S. K. , Paknikar K. M.
Published: October 2004

Cadmium sulfide nanoparticles were synthesized intracellularly by a Schizosaccharomyces pombe strain when challenged with 1 mM cadmium in solution. The nanoparticles, a known semiconducting material, exhibited an absorbance maximum at 305 nm. X‐ray scattering data showed that the nanoparticles had a Wurtzite (Cd16S20)‐type hexagonal lattice structure and most of the nanoparicles were in the size range of 1–1.5 nm. The nanoparticles were used in the fabrication of a heterojunction with poly (p‐phenylenevinylene). The diode exhibited ∼75 mA/cm2 current at 10 V when forward biased and the breakdown occurred at ∼15 V in the reverse biased mode. These characteristics are considered ideal for a diode. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 78: 583–588, 2002.
Production of wild‐type and peptide fusion cutinases by recombinant Saccharomyces cerevisiae MM01 strains
Authors: Calado Cecília R. C. , Mannesse Maurice , Egmond Maarten , Cabral Joaquim M. S. , Fonseca Luis P.
Published: October 2004

This study focused on the growth of Saccha‐romyces cerevisiae MM01 recombinant strains and the respective production of three extracellular heterologous cutinases: a wild‐type cutinase and two cutinases in which the primary structure was fused with the peptides (WP)2 and (WP)4, respectively. Different cultivation and strategies were tested in a 2‐L shake flask and a 5‐L bioreactor, and the respective cell growth and cutinase production were analyzed and compared for the three yeast strains. The highest cutinase productions and productivities were obtained in the fed‐batch culture, where wild‐type cutinase was secreted up to a level of cutinase activity per dry cell weight (specific cell activity) of 4.1 Umg−1 with activity per protein broth (specific activity) of 266 Umg−1, whereas cutinase‐(WP)2 was secreted with a specific cell activity of 2.1 Umg−1 with a specific activity of 200 Umg−1, and cutinase‐(WP)4 with a specific cell activity of 0.7 Umg−1 with a specific activity of 15 Umg−1. The results indicate that the fusion of hydrophobic peptides to cutinase that changes the physical properties of the fused protein limits cutinase secretion and subsequently leads to a lower plasmid stability and lower yeast cell growth. These effects were observed under different cultivation conditions (shake flask and bioreactor) and cultivation strategies (batch culture versus fed‐batch culture). © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 78: 692–698, 2002.
A case of acute myocardial infarction treated with a new thrombectomy system
Authors: Nishida Takahiro , Nakamura Masato , Tsunoda Taro , Iijima Raisuke , Shiba Masanori , Wada Masamichi , Nakajima Rintaro , Kitagawa Yoko , Yajima Suguru , Wakayama Megumi , Shibuya Kazutoshi , Yamaguchi Tetsu
Published: October 2004

Thrombotic occlusion in the culprit lesion of acute myocardial infarction was successfully recanalized using a 4.5 Fr thrombectomy catheter (RESCUE), which was also used to normalize the coronary blood flow. The retrieved specimens were white thrombi containing red thrombi and cholesterol crystals, indicating plaque rupture. Cathet Cardiovasc Intervent 2002;55:239–243. © 2002 Wiley‐Liss, Inc.
Intravascular ultrasound evaluation of ruptured plaque in the left main coronary artery misinterpreted as an aneurysm by angiography
Authors: Li Yuxin , Honye Junko , Takayama Tadateru , Saito Satoshi
Published: October 2004

We report a patient who demonstrated a left main coronary aneurysm by angiography. Intravascular ultrasound (IVUS) revealed that it was in fact an ulceration, which indicated ruptured plaque. This case provides evidence that IVUS can permit a more powerful definition of ruptured plaque than angiography. On IVUS, ulceration exhibits significantly different characteristics from aneurysm. Cathet Cardiovasc Interv 2004;63:314–316. © 2004 Wiley‐Liss, Inc.
Gadolinium‐based balloon angioplasty for pulmonary artery stenosis in an infant with a right isomerism
Authors: Sugiyama Hisashi , Kadono Toshie , Hoshiai Minako , Tan Tetsushi , Koizumi Keiichi , Sakamoto Hajime , Nakazawa Simpei
Published: October 2004

We report here the first described case of utilizing gadolinium‐based contrast material as the contrast agent during a catheter intervention treatment for pulmonary artery stenosis. The patient, a male infant with complex heart disease associated with a right isomerism, had a history of severe allergic reaction to iodine‐containing contrast agents. A combination of digital subtraction angiography and a gadolinium contrast agent, however, provided us with good‐quality images both before and after balloon angioplasty without any associated complications. This method should therefore be considered as an alternative angiographic procedure in children with a high risk of iodine‐related allergic complications. Catheter Cardiovasc Interv 2004;63:346–350. © 2004 Wiley‐Liss, Inc.
Atypical hemodynamic manifestations of cardiac tamponade
Authors: Sharma Naveen , Panchal Vipul , Kalaria Vijay G.
Published: October 2004

Clinical examination and transthoracic echocardiography play a vital role in the management of patients with pericardial effusion and cardiac tamponade physiology. We report patients in advanced phase 3 cardiac tamponade with variant clinical and hemodynamic presentations. These atypical cardiac tamponade cases include: A patient with severe aortic valve regurgitation who lacked pulsus paradoxus; a patient with systemic sclerosis without hypotension; and a patient with pulmonary hypertension lacking right heart collapse on echocardiography. Recognition of these atypical clinical and hemodynamic manifestations of cardiac tamponade will avoid undue delay in the treatment. Catheter Cardiovasc Interv 2004;63:339–345. © 2004 Wiley‐Liss, Inc.
Phase I study of eniluracil and oral 5‐fluorouracil in combination with docetaxel in the treatment of patients with metastatic breast carcinoma
Authors: Rivera Edgardo , Valero Vicente , Cristofanilli Massimo , Frye Debra K. , Booser Daniel J. , Rosales Marguerite M. , Hortobagyi Gabriel N.
Published: October 2004

PURPOSE

The authors conducted a single‐institution Phase I clinical trial to determine the maximum tolerated doses and to define the toxic effects of oral eniluracil and oral 5‐fluorouracil (5‐FU) combined with docetaxel in patients with metastatic breast carcinoma.

PATIENTS AND METHODS.

Patients with metastatic breast carcinoma were eligible if they had disease progression after anthracycline‐based therapy and had never been exposed to taxanes. The starting doses of oral eniluracil and oral 5‐FU were 11.5 mg/m2 and 1.15 mg/m2, respectively, twice daily on Days 1–14. Docetaxel was given intravenously at a starting dose of 50 mg/m2 on Day 1 only. The dose of docetaxel was escalated among cohorts until a maximum tolerated dose was reached. Courses were repeated every 21 days.

RESULTS

The authors treated 19 patients with Stage IV breast carcinoma, of whom 5 had received prior chemotherapy for their metastatic disease. Fifty‐three percent had a performance status of 1, and 53% had bone or soft tissue involvement as the dominant site of disease. All patients had received prior therapy with doxorubicin. The dose‐limiting toxicity was neutropenic fever. No episodes of sepsis were observed. Significant antitumor activity was observed with a total of two complete and nine partial responses. The recommended doses for Phase II studies are 72 mg/m2 docetaxel on Day 1 and 10.0/1.0 mg/m2 oral eniluracil/5‐FU twice daily for a total of 14 days, with courses being repeated every 21 days.

CONCLUSIONS

The combination of oral eniluracil/5‐FU and intravenous docetaxel is a safe and well tolerated regimen. Significant antitumor activity is associated with this combination. Cancer 2002;94:2321–6. © 2002 American Cancer Society.

DOI 10.1002/cncr.10488
CD56+ TdT+ blastic natural killer cell tumor of the skin
Authors: Khoury Joseph D. , Medeiros L. Jeffrey , Manning John T. , Sulak Laura E. , Bueso‐Ramos Carlos , Jones Dan
Published: October 2004

BACKGROUND

An unusual cutaneous tumor that has blastic morphology and coexpresses CD56 and terminal deoxynucleotidyl transferase (TdT) has been recently recognized and termed blastic natural killer cell lymphoma.

METHODS

The authors identified seven cases of such CD56+TdT+ blastic tumors presenting in skin at their institution. The authors correlated clinical course with histomorphology and immunophenotype.

RESULTS

All 7 patients (6 men, 1 woman, 52‐85 years) presented with rapidly growing, frequently multiple cutaneous nodules. All patients had low level bone marrow involvement at diagnosis and frequently had lymph node involvement. Tumor cells were of intermediate size with irregular nuclear contours, fine chromatin, and indistinct small nucleoli. The expression of TdT varied between 5% and over 90% of the neoplastic cell population. Tumor cells were negative for surface CD3, CD5, and CD20 in all cases, but some patients showed expression of CD2 (three out of five), cytoplasmic CD3 (two out of seven), CD4 (six out of seven), and CD16 (three out of seven). Molecular studies showed absence of T‐cell receptor gene rearrangements in all cases. All seven patients had rapid progression of disease, and six patients have died of their disease or complications. Three patients developed progressively increasing numbers of bone marrow blasts that had a myeloid immunophenotype and were negative for TdT and CD56. Two patients met criteria for acute myeloid leukemia at 11 and 22 months after presentation, respectively.

CONCLUSIONS

CD56+ TdT+ blastic tumor presenting in skin is a systemic malignancy likely of primitive/undifferentiated hematopoietic origin. Patients might subsequently develop tumors of myeloid or myelomonocytic phenotype, indistinguishable from acute myelogenous leukemia. Cancer 2002;94:2401–8. © 2002 American Cancer Society.

DOI 10.1002/cncr.10489
Two schedules of second‐line irinotecan for metastatic colon carcinoma
Authors: Earle Craig C. , Kwok Ambrose , Gazelle G. Scott , Fuchs Charles S.
Published: October 2004

BACKGROUND

In a recently reported, randomized trial, it was found that a regimen of irinotecan once every 3 weeks for patients with advanced colorectal carcinoma was associated with a lower incidence of severe diarrhea compared with weekly treatment, and both regimens had similar efficacy.

METHODS

Resource utilization was captured prospectively for all 291 patients who were included in the trial. Utilities were estimated by transformation of the global quality‐of‐life (QOL) item on the Eastern Organization for Research and Treatment of Cancer QLQ‐C30 instrument.

RESULTS

Patients in the every‐3‐week arm incurred an average incremental cost of $1362, because they received higher average weekly doses and because the every‐3‐week regimen resulted in less toxicity, allowing delivery of 97% of the planned doses compared with delivery of only 75% of the planned doses in the weekly arm. This lower toxicity also resulted in offsetting savings from decreased hospitalization and less requirement for supportive medications. Non‐chemotherapy‐related treatment administration costs also were lower, because the every‐3‐week regimen could be delivered with half the number of infusions. Utility declined less in the every‐3‐week arm, resulting in a saving of 6.3 quality‐adjusted days. The base‐case cost:utility ratio was $78,627 per quality‐adjusted life year for patients on the every‐3‐week schedule. However, that ratio was very sensitive to the cost of irinotecan.

CONCLUSIONS

The schedule of irinotecan once every 3 weeks schedule was more costly but achieved lower toxicity, resulting in modestly improved utility. The cost‐per‐utility ratio was comparable to other commonly accepted contemporary treatments. Cancer 2004. © 2004 American Cancer Society.
Morphology of horizontal cells in the retina of the capuchin monkey, Cebus apella: How many horizontal cell classes are found in dichromatic primates?
Authors: dos Reis José Wesley L. , de Carvalho Walther Augusto , Saito Cézar A. , Silveira Luiz Carlos L.
Published: October 2004

The morphology of horizontal cells was studied in the retina of dichromatic capuchin monkeys, Cebus apella. The cells were labeled with the carbocyanine dye, 1,1′,dioctadecyl‐3,3,3′,3′‐tetramethylindocarbocyanine perchlorate (DiI), and the labeling was then photoconverted to a stable product by using a diaminobenzidine reaction. The sizes of cell body, dendritic field, and axon terminal, as well as the number of dendritic clusters and cone convergence, were measured at increasing distance from the fovea. Three distinct morphological classes of horizontal cells were identified. Their dendritic and axonal morphology resembles those of H1, H2, and H3 cells described in trichromatic primates. The size of the cell bodies, dendritic fields, and axon terminals of all cell classes increases towards retinal periphery. H3 cells have larger dendritic fields and more dendritic clusters than H1 cells. All labeled horizontal cells located in selected patches of retina were further analyzed to quantify the differences between H1 and H3 cells. H1 cells have smaller dendritic field area, smaller total length of primary dendrites, more dendritic branching points, and larger fractal dimension than H3 cells. We have distinguished H1 and H3 cells based solely in morphological criteria. Their physiology should be further analyzed with detail, but their presence in both dichromatic and trichromatic primates suggests that neither of them have a specialized role in the red‐green color opponent channel of color vision. J. Comp. Neurol. 443:105–123, 2002. © 2002 Wiley‐Liss, Inc.
Androgenic regulation of expression of androgen receptor protein in the perineal motoneurons of aged male rats
Authors: Matsumoto Akira , Prins Gail S.
Published: October 2004

Androgen might regulate expression of androgen receptors (AR) in AR‐containing motoneurons in young animals. In the present study, it was examined whether expression of AR was also regulated by androgen in aged animals. Twelve male rats were castrated at 26 months of age. Five days following castration, the animals were treated with testosterone propionate (TP; six males) or vehicle (six males) and killed 2 hours later. Six sham‐castrated rats served as controls. AR immunoreactivity was examined in motoneurons of the spinal nucleus of the bulbocavernosus (SNB) in these animals by immunohistochemistry using the polyclonal antibody PG21. In control animals, slightly intense AR immunoreactivity was confined to the nuclei of the motoneurons. AR immunoreactivity was completely eliminated in the motoneurons of castrated rats. In castrated, aged animals treated with TP, the intensity of AR immunoreactivity in the nuclei of SNB motoneurons was increased. Plasma levels of testosterone in castrated, aged animals 2 hours following treatment with TP were significantly greater than those in controls. These results suggest that expression of AR in motoneurons of the SNB in aged male rats is up‐regulated in response to androgen and that androgen may be, at least in part, involved in the process of aging of the SNB in male rats. J. Comp. Neurol. 443:383–387, 2002. © 2002 Wiley‐Liss, Inc.
Several subpopulations of neuropeptide Y– containing neurons exist in the infundibular nucleus of sheep: An immunohistochemical study of animals on different diets
Authors: Chaillou Elodie , Baumont René , Chilliard Yves , Tillet Yves
Published: October 2004

Conversely to rodents, the involvement of hypothalamic neuropeptide Y (NPY) neurons in the control of nutrition is poorly understood in ruminants such as sheep. Therefore, the aim of this work was to describe the NPY neurons of the diencephalon in ewes submitted to different diets. In colchicine‐treated animals, large populations of NPY‐immunoreactive (‐ir) neurons were observed in a ventral and a lateral subpopulation of the infundibular nucleus (IN), in the median eminence, the pituitary stalk, and the dorsomedian and dorsocaudal nuclei. No labeled perikaryon was observed in the magnocellular neurons of the hypothalamus, although numerous labeled fibers were noted in the neural part of the pituitary. The pattern of distribution of NPY‐ir neurons in the sheep hypothalamus is similar in many ways to those of rodents, but it presents also many specific characteristics that have not been previously described. In ewes that were fasted for 24 hours, or fed ad libitum, the number of NPY‐ir neurons was the same whatever the hypothalamic structures. In underfed ewes (40% of maintenance for 24 weeks), the lateral subpopulation of the IN presented a higher number of NPY‐ir neurons than observed in the 100% fed ewes. Conversely, in the ventral subpopulation, the animals refed ad libitum (at least 150% of maintenance for 4 days) presented a lower number of NPY‐ir neurons than the other groups. The other NPY neuronal populations of the hypothalamus were not significantly modified by the dietary treatments. For the first time, we demonstrated the presence of two functionally distinct subpopulations of NPY neurons in the sheep IN. The variations of labeled neurons were correlated with plasma nonesterified fatty acid levels but not with leptinemia. J. Comp. Neurol. 444:129–143, 2002. © 2002 Wiley‐Liss, Inc.
Expression patterns of Notch1, Notch2, and Notch3 suggest multiple functional roles for the Notch‐DSL signaling system during brain development
Authors: Irvin Dwain K. , Zurcher Shelley D. , Nguyen Theanh , Weinmaster Gerry , Kornblum Harley I.
Published: October 2004

The Notch‐DSL signaling system consists of multiple receptors and ligands, and plays many roles in development. The function of Notch receptors and ligands in mammalian brain, however, is poorly understood. In the current study, we examined the expression patterns for three receptors of this system, Notch1, 2, and 3, in late embryonic and postnatal rat brain by in situ hybridization. The three receptors have overlapping but different patterns of expression. Messenger RNA for all three proteins is found in postnatal central nervous system (CNS) germinal zones and, in early postnatal life, within numerous cells throughout the CNS. Within zones of cellular proliferation of the postnatal brain, Notch1 mRNA is found in both the subventricular and the ventricular germinal zones, whereas Notch2 and Notch3 mRNAs are more highly localized to the ventricular zones. Both Notch1 and Notch3 mRNAs are expressed along the inner aspect of the dentate gyrus, a site of adult neurogenesis. Notch2 mRNA is expressed in the external granule cell layer of the developing cerebellum. In several brain areas, Notch1 and Notch2 mRNAs are relatively concentrated in white matter, whereas Notch3 mRNA is not. Neurosphere cultures (which contain CNS stem cells), purified astrocyte cultures, and striatal neuron‐enriched cultures express Notch1 mRNA. However, in these latter cultures, Notch1 mRNA is produced by nestin‐containing cells, rather than by postmitotic neurons. Taken together, these results support multiple roles for Notch1, 2, and 3 receptor activation during CNS development, particularly during gliogenesis. J. Comp. Neurol. 436:167–181, 2001. © 2001 Wiley‐Liss, Inc.
Vanilloid receptor VR1 is both presynaptic and postsynaptic in the superficial laminae of the rat dorsal horn
Authors: Valtschanoff Juli G. , Rustioni Aldo , Guo Athena , Hwang Se Jin
Published: October 2004

Terminals in the rat spinal cord that express the vanilloid receptor VR1 are from small and medium dorsal root ganglion (DRG) neurons and appear prominent in lamina I and inner lamina II. Because primary afferents from these neurons can be myelinated or unmyelinated and their terminals in these laminae can be of various morphological and functional types, we undertook this study to identify the type(s) of VR1‐positive afferent fibers and terminals. In the DRG, many small and medium‐sized neurons are immunopositive. Under electron microscopy, dorsal root afferents that are immunopositive for VR1 are predominantly unmyelinated. Large numbers of VR1‐positive terminals in lamina I are of the nonglomerular type and may contain dense core vesicles. VR1 immunoreactivity in terminals in lamina I is in good agreement with data on noxious, heat‐sensitive neurons in the dorsal horn. Two types of glomerular afferent terminals in lamina II also are immunopositive for VR1. In both laminae, most VR1‐positive terminals are distinct from substance P‐positive terminals. However, the immunoreactivity in lamina II also is prominent in dendrites that are contacted by primary afferent endings. Because we also observed patchy immunostaining in cell bodies in lamina II, this unexpected result may reflect synthesis of VR1 by neurons in this lamina. However, because dorsal rhizotomy abolishes VR1 staining in both laminae I and II, it is suggested that the expression and intracellular dynamics of VR1 in lamina II neurons are controlled by presynaptic input. J. Comp. Neurol. 436:225–235, 2001. © 2001 Wiley‐Liss, Inc.