bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Specificity of Lipoxygenase-Catalyzed Lipid Peroxidation and the Effects of Radical- Scavenging Antioxidants
Authors: Noguchi N. , Yamashita H. , Hamahara J. , Nakamura A. , Kühn H. , Niki E. 
Published: October 2004

AbstractThe oxidation of low density lipoprotein (LDL) by lipoxygenase has been implicated in the pathogenesis of atherosclerosis. It has been known that lipoxygenasemediated lipid peroxidation proceeds in general via regio, stereo and enantiospecific mechanisms, but that it is sometimes accompanied by a share of random hydroperoxides as side reaction products. In this study we investigated the oxidation of various substrates (linoleic acid, methyl linoleate, phosphatidylcholine, isolated LDL, and human plasma) by the arachidonate 15-lipoxygenases from rabbit reticulocytes and soybeans aiming at elucidating the effects of substrate, lipoxygenase and reaction milieu on the contribution and mechanism of random oxidation and also the effect of antioxidant. The specific character of the rabbit 15-lipoxygenase reaction was confirmed under all conditions employed here. However, the specificity by soybean lipoxygenase was markedly dependent on the conditions. When phosphatidylcholine liposomes and LDL were oxygenated by soybean lipoxygenase, the product pattern was found to be exclusively regio, stereo, and enantiorandom. When free linoleic acid was incorporated into PC liposomes and oxidized by soybean lipoxygenase, the free acid was specifically oxygenated, whereas esterified linoleate gave random oxidation products exclusively. Radicalscavenging antioxidants such as αtocopherol, ascorbic acid and 2-carboxy-2,5,7,8-tetramethyl-6-chromanol selectively inhibited the random oxidation but did not influence specific product formation. It is assumed that the random reaction products originate from free radical intermediates, which have escaped the active site of the enzyme and thus may be accessible to radical scavengers. These data indicate that the specificity of lipoxygenasecatalyzed lipid oxidation and the inhibitory effects of antioxidants depend on the physicochemical state of the substrate and type of lipoxygenase and that they may change completely depending on the conditions.
Calpain Function in the Differentiation of Mesenchymal Stem Cells
Authors: Yajima Yukiko , Kawashima Seiichi 
Published: October 2004

AbstractCalpain is a calciumactivated non lysosomal neutral thiol protease (EC 3.4.22.17) present in a wide variety of eukaryotic cells. Calpain is usually present as an inactive form and is activated by calcium ions and phospholipids. The ability of calpain to alter, by limited proteolysis, the activity or function of numerous cytoskeletal proteins, enzymes, and receptors suggests its involvement in various Ca2+ regulated cellular functions. In this review we focus on the differentiation of mesenchymal stem cells, such as the myoblastic, osteoblastic, chondrocytic, and adipocytic lineages, and the biological significance of calpain in its regulation. Calpain has been implicated in the differentiation of myoblasts through the turnover of glycoproteins. In preosteoblastic cells, calpain is important in mediating the proliferative and prodifferentiating effects of parathyroid hormone and bone morphogenetic proteins. For the differentiation of chondrocytes, calpain is involved in cartilagematrix mineralization. Furthermore, calpain is required for the differentiation of 3T3-L1 preadipocytes into adipocytes, involving the transcriptional activation of the C/EBPα gene and the degradation of the cyclindependent kinase inhibitor p27 during the mitotic clonal expansion phase of adipocyte differentiation. We summarize these regulatory effects of calpain on the differentiation of mesenchymal stem cells and speculate on the function and location of calpain in the differentiation processes.
Selective Release of Calpain Produced αII-Spectrin (α-Fodrin) Breakdown Products by Acute Neuronal Cell Death
Authors: Dutta Satavisha , Chiu Yuk Chun , Probert Albert W. , Wang Kevin K.W. 
Published: October 2004

AbstractActivation of calpain results in the breakdown of α II spectrin (αfodrin), a neuronal cytoskeleton protein, which has previously been detected in various in vitro and in vivo neuronal injury models. In this study, a 150 kDa spectrin breakdown product (SBDP150) was found to be released into the cellconditioned media from SHSY5Y cells treated with the calcium channel opener maitotoxin (MTX). SBDP150 release can be readily quantified on immunoblot using an SBDP150- specific polyclonal antibody. Increase of SBDP150 also correlated with cell death in a timedependent manner. MDL28170, a selective calpain inhibitor, was the only protease inhibitor tested that significantly reduced MTXinduced SBDP150 release. The cellconditioned media of cerebellar granule neurons challenged with excitotoxins (NMDA and kainate) also exhibited a significant increase of SBDP150 that was attenuated by pretreatment with an NMDA receptor antagonist, R()-3-(2-carbopiperazine-4-yl)propyl-1- phosphonic acid (CPP), and MDL28170. In addition, hypoxic/hypoglycemic challenge of cerebrocortical cultures also resulted in SBDP150 liberation into the media. These results support the theory that an antibody based detection of SBDP150 in the cellconditioned media can be utilized to quantify injury to neural cells. Furthermore, SBDP150 may potentially be used as a surrogate biomarker for acute neuronal injury in clinical settings.
Effect of Cysteine Proteinase Inhibitors on Murine B16 Melanoma Cell Invasion in vitro
Authors: Sever Natasa , Filipic Metka , Brzin Joze , Lah Tamara T. 
Published: October 2004

AbstractVarious types of proteinases are implicated in the malignant progression of human and animal tumors. Proteinase inhibitors may therefore be useful as therapeutic agents in antiinvasive and antimetastatic treatment. The aims of this study were (1) to estimate the relative importance of proteinases in B16 cell invasion in vitro using synthetic, classspecific proteinase inhibitors and (2) to assess the inhibitory effect of some naturally occurring cysteine proteinase inhibitors. Serine proteinase inhibitor reduced invasiveness by up to 24%, whereas inhibition of aspartic proteinases reduced invasion by 11%. Synthetic inhibitors of cysteine proteinases markedly impaired invasion: cathepsin B inhibitors, particularly Ca 074Me, inhibited invasion from 20 40%, whereas cathepsin L inhibitor Clik 148 reduced invasion by 11%. The potato cysteine proteinase inhibitor PCPI 8.7 inhibited invasion by 21%, whereas another potato inhibitor, PCPI 6.6, and the mushroom cysteine proteinase inhibitor clitocypin had no effects. As the inhibitors that inhibited cathepsin B were in general more efficient at impairing the invasiveness, we conclude that of the two cysteine proteinases, cathepsin B plays a more important role than cathepsin L in murine melanoma cell invasion.
Design of Inhibitors for Human Tissue Kallikrein Using Non-Natural Aromatic and Basic Amino Acids
Authors: Pimenta Daniel C. , Melo Robson L. , Caliendo Giuseppe , Santagada Vincenzo , Fiorino Ferdinando , Severino Beatrice , Nucci Gilberto de , Juliano Luiz , Juliano Maria A. 
Published: October 2004

AbstractWe explored the unique substrate specificity of the primary S1 subsite of human urinary kallikrein (hK1), which accepts both Phe or Arg synthesizing and assaying peptides derived from PhenylacetylPheSer ArgEDDnp, a previously described inhibitor with analgesic and antiinflammatory activities [Emim et al., Br. J. Pharmacol. 130 (2000), 1099 1107]. Phe was substituted by amino acids containing larger aliphatic or aromatic side chains as well as by nonnatural basic amino acids, which were designed to combine a large hydrophobic and/or aromatic group with a positivelycharged group at their side chains. In general, all peptides with basic amino acids represented better inhibitors than those with hydrophobic amino acids. Furthermore, the S1 subsite specificity proved to be much more selective than the mere distinction between Phe and Arg, for minor differences in the side chains of the nonnatural amino acids resulted in major differences in the Ki values. Finally, we present a series of peptides that were assayed as competitive inhibitors for human tissue kallikrein that may lead to the development of novel peptides, which are both more potent and selective.
Novel Secretory Vesicle Serpins, Endopin 1 and Endopin 2: Endogenous Protease Inhibitors with Distinct Target Protease Specificities
Authors: Hook V. Y. H. , Hwang S.-R. 
Published: October 2004

AbstractSecretory vesicles of neuroendocrine cells possess multiple proteases for proteolytic processing of proteins into biologically active peptide components, such as peptide hormones and neurotransmitters. The importance of proteases within secretory vesicles predicts the presence of endogenous protease inhibitors in this subcellular compartment. Notably, serpins represent a diverse class of endogenous protease inhibitors that possess selective target protease specificities, defined by the reactive site loop domains (RSL). In the search for endogenous serpins in model secretory vesicles of neuroendocrine chromaffin cells, the presence of serpins related to α1-antichymotrypsin (ACT) was detected by Western blots with antiACT. Molecular cloning revealed the primary structures of two unique serpins, endopin 1 and endopin 2, that possess homology to ACT. Of particular interest was the observation that distinct RSL domains of these new serpins predicted that endopin 1 would inhibit trypsinlike serine proteases cleaving at basic residues, and endopin 2 would inhibit both elastase and papain that represent serine and cysteine proteases, respectively. Endopin 1 showed selective inhibition of trypsin, but did not inhibit chymotrypsin, elastase, or subtilisin. Endopin 2 demonstrated crossclass inhibition of the cysteine protease papain and the serine protease elastase. Endopin 2 did not inhibit chymotrypsin, trypsin, plasmin, thrombin, furin, or cathepsin B. Endopin 1 and endopin 2 each formed SDSstable complexes with target proteases, a characteristic property of serpins. In neuroendocrine chromaffin cells from adrenal medulla, endopin 1 and endopin 2 were both localized to secretory vesicles. Moreover, the inhibitory activity of endopin 2 was optimized under reducing conditions, which required reduced Cys-374; this property is consistent with the presence of endogenous reducing agents in secretory vesicles in vivo. These new findings demonstrate the presence of unique secretory vesicle serpins, endopin 1 and endopin 2, which possess distinct target protease selectivities. Endopin 1 inhibits trypsinlike proteases; endopin 2 possesses crossclass inhibition for inhibition of papainlike cysteine proteases and elastaselike serine proteases. It will be of interest in future studies to define the endogenous protease targets of these two novel secretory vesicle serpins.
Cathepsin B Stability, But Not Activity, Is Affected in Cysteine:Cystine Redox Buffers
Authors: Pillay C. S. , Dennison C. 
Published: October 2004

AbstractIn order to test the hypothesis that the lysosomal cysteine protease cathepsin B may be redox regulated in vivo, cathepsin B activity and stability were measured in cysteine and/or cystinecontaining buffers. Cathepsin B activity in cysteinecontaining buffers was similar at pH 6.0 and pH 7.0, over all thiol concentrations tested. In contrast, the stability of the enzyme was greater at pH 6.0 than at pH 7.0. This suggests that the enzymes operational pH in vivo may be < pH 7.0. The activity of the enzyme was depressed in glutathionecontaining buffers. When assessed in cysteine:cystine redox buffers (pH 6.0 7.0) cathepsin B was active over a broad redox potential range, suggesting that cathepsin B activity may not be redox regulated. However, at pH 7.0, the stability of cathepsin B decreased with increasing reduction potential and ambient cystine concentration. This suggests that the stability of the enzyme at neutral pH is dependent on redox potential, and on the presence of oxidising agents.
Reverse Genetic Analysis of the Caenorhabditis elegans 26S Proteasome Subunits by RNA Interference
Authors: Takahashi M. , Iwasaki H. , Inoue H. , Takahashi K. 
Published: October 2004

AbstractReverse genetic analysis was performed on the Caenorhabditis elegans 26S proteasome subunit genes by doublestranded RNAmediated interference (RNAi). Embryonic and postembryonic lethality was caused by interference of all of the eight tested 20S core subunits and all of the 19S regulatory particle subunits except for CeRpn9, CeRpn10, and Ce Rpn12, where RNAi caused no abnormality. However, synthetic suppression of CeRpn10 and CeRpn12 was lethal, whereas neither the combination of Ce Rpn9 with CeRpn10 nor with CeRpn12 resulted in abnormalities in RNAi. These results indicate that the 26S proteasome is indispensable for embryogenesis and postembryonic development, although Ce Rpn9, CeRpn10, and CeRpn12 are not essential, at least under the conditions used. CeRpn10 and Ce Rpn12 are considered to compensate for the suppression of each other.
Functional Consequences of Cathepsin L Deficiency in Human Lung Epithelial Cells
Authors: Wille A. , Heimburg A. , Gerber A. , Reisenauer A. , Welte T. , Bühling F. 
Published: October 2004

AbstractCathepsin L is a cysteine protease of the papain family. Lung epithelial cells play an important role in host defence. The aim of the present study was to investigate the functional role of cathepsin L in the human lung carcinoma cell line A549. Cathepsin Ldeficient A549 clones were generated. They showed a significant lower proliferation and secreted 5- to 8-fold more IL-8 than the control cells. The production of IL 6, IL-18, and TGFβ1/2 was not affected significantly. It was shown that the cells upregulate IL-8 transcription and that IL-8 in the culture supernatant is necessary for the containment of cellular proliferation. In conclusion, the data show that suppression of cathepsin L expression in A549 cells leads to a growth inhibition which is partially compensated by an upregulation of IL-8 production.
Kaposis Sarcoma and Human Chorionic Gonadotropin: Mechanisms, Moieties and Mysteries
Authors: Bisacchi D. , Noonan D. M. , Carlone S. , Albini A. , Pfeffer U. 
Published: October 2004

AbstractKaposis Sarcoma (KS) is a highly angiogenic neoplasm associated with infection by the human γherpesvirus, HHV-8 or Kaposis sarcoma herpes virus (KSHV). When in 1872 the Hungarian scientist Moritz Kaposi described the sarcoma, which was later named after him, he was dealing with a rare dermatologic disease. Today, KS is a more common pathology due to its high incidence in AIDS, in immunosuppressed transplantation patients and, in its endemic form, in Africa. The introduction of highly active antiretroviral therapy (HAART) has led to a drastic reduction of KS incidence in HIVinfected patients, but in some cases KS resists the treatment. KS is more common in men than in women. The observation of spontaneous remissions during pregnancy stimulated investigations into the potential antiKS activity of the pregnancy hormone human chorionic gonadotropin (hCG). The variable effect in clinical trials using urinary preparations of the hormone (uhCG) has led to the hypothesis that contaminating moieties present in these preparations may account for the antiKS effect observed in vitro. While the discrepancy between laboratory tests and clinical trials remains a mystery, little is known about potential antiKS mechanisms of the hormone itself and/or other active moieties present in uhCG.
Lipid Rafts in Protein Sorting and Cell Polarity in Budding Yeast Saccharomyces cerevisiae
Authors: Bagnat M. , Simons K. 
Published: October 2004

AbstractCellular membranes contain many types and species of lipids. One of the most important functional consequences of this heterogeneity is the existence of microdomains within the plane of the membrane. Sphingolipid acyl chains have the ability of forming tightly packed platforms together with sterols. These platforms or lipid rafts constitute segregation and sorting devices into which proteins specifically associate. In budding yeast, Saccharomyces cerevisiae, lipid rafts serve as sorting platforms for proteins destined to the cell surface. The segregation capacity of rafts also provides the basis for the polarization of proteins at the cell surface during mating. Here we discuss some recent findings that stress the role of lipid rafts as key players in yeast protein sorting and cell polarity.
Protein Transduction: A Novel Tool for Tissue Regeneration
Authors: Cardoso M. C. , Leonhardt H. 
Published: October 2004

AbstractTissue regeneration in humans is limited and excludes vitals organs like heart and brain. Transformation experiments with oncogenes like T antigen have shown that retrodifferentiation of the respective cells is possible but hard to control. To bypass the risk of cancer formation a protein therapy approach has been developed. The transient delivery of proteins rather than genes could still induce terminallydifferentiated cells to reenter the cell cycle. This approach takes advantage of proteintransducing domains that mediate the transfer of cargo proteins into cells. The goal of this brief review is to outline the basics of protein transduction and to discuss potential applications for tissue regeneration.
Processing and Activation of Lysosomal Proteinases
Authors: Ishidoh K. , Kominami E. 
Published: October 2004

AbstractLysosomal proteinases are translated as preproenzymes, transferred through the Golgi apparatus as proenzymes, and localized in lysosomes as the mature enzymes. Pulsechase analyses and the immunoisolation of proenzymes or recombinant proenzymes are useful tools for analyzing this process, but the processing proteinases that participate in this pathway are largely unknown. Recently, we developed a new method for analyzing processing proteinases using Bafilomycin A1 and proteinase inhibitors. Here we summarize the recent progress including our results obtained using this method.
The Promoter Context Determines Mutual Repression or Synergism between NF-κB and the Glucocorticoid Receptor
Authors: Hofmann T.G. , Schmitz M.L. 
Published: October 2004

Abstract
While the biochemical mechanisms mediating repression
of NFκB activity by glucocorticoids (GCs)
are relatively well studied, the role of promoter architecture
for the effects of GCs on NFκB remains poorly
characterized. Therefore we constructed a set of
synthetic promoter reporter constructs containing
various numbers of GCresponsive elements (GREs)
in distinct distances to NFκB binding sites. TNFαinduced
activity of a synthetic promoter controlled by
three NFκB binding sites was repressed by dexamethasone.
The presence of only one GRE in the vicinity
of the κB sites abolished this repression and allowed
synergistic transcriptional activation by NFκB
and the glucocorticoid receptor (GR). The synergism
identified here was not affected by the number of
GREs, but strictly depends on the spacing between
GREs and κB sites. These experiments reveal that the
functional interplay between NFκB and the GR also
involves dependent on the promoter context synergistic
stimulation of transcription.
The Chemical Nature of Kiln Brown Stain in Radiata Pine
Authors: McDonald Armando G. , Fernandez Marc , Kreber Bernhard , Laytner Frank 
Published: October 2004

Summary
This paper presents results of a study on the chemical nature of kiln brown stain (KBS) that develops in
kiln dried radiata pine (Pinus radiata D. Don) sapwood. KBS is a chocolate brown discolouration which
develops approximately 0.5 mm under the timber surface. Stain free radiata pine was achieved during
drying trials on “green” radiata pine sapwood which had been treated to extensive cold and hot water
extraction. Differences in chemical composition between the sap and hot water extract were observed.
Chemical analyses (of the water-soluble extracts) by a combination of chromatographic and spectroscopic
techniques, demonstrated that carbohydrates, cyclitols, amino acids, protein, and phenolics were
the main compound classes present. The presence of reducing sugars (glucose and fructose) and amino
acids (glutamic acid) in the sap and hot water extracts support the theory that Amadori-Maillard type
reactions significantly contribute to the formation of colour in KBS. Furthermore, lignin was also detected
and is suspected to contribute to KBS formation. The relative contributions of colour formation to
KBS intensity from either phenolics or Maillard-Amadori mechanisms is unknown.
X-Ray Diffraction as an Analytical Method in Wood Preservatives
Authors: Zhang J. , Kamdem D. P. 
Published: October 2004

Summary
X-ray diffraction (XRD) technique was used to analyze qualitatively and semi-quantitatively solid crystal
deposits in wood treated with some preservatives. Chromated copper arsenate type-C (CCA), copper
ethanolamine (Cu-EA), copper naphthenate (Cu-N), copper dimethyldithiocarbamate (CDDC) and boric
acid treated southern pine was investigated. The solid deposit in post-treatment steamed Cu-N and Cu-EA treated wood samples was identified as cuprous oxide (Cu2O) by using XRD. The presence of CDDC
crystals was observed in CDDC treated wood samples. The XRD pattern of boric acid treated wood
shows that crystalline boric acid is present in the treated wood. After washing boric acid treated wood
with distilled water, the crystalline signal of boric acid disappeared. An XRD technique was also developed
to semi-quantify the amount of solid crystals in post-treatment steamed Cu-N treated and CDDC
treated samples. It was estimated that about 50% of cupric copper was converted to cuprous oxide
(Cu2O) in Cu-N treated wood after post treatment steaming whereas no cuprous oxide was found in non
post-treatment steamed Cu-N treated samples. The CDDC content determined by XRD was consistently
10–20% lower than the value calculated from the copper content using atomic absorption spectroscopy
(AAS) analysis.
Preparation of Wood with Thermoplastic Properties, Part 2. Simplified Technologies
Authors: Timar Maria Cristina , Maher Kevin , Irle Mark , Mihai Maria Daniela 
Published: October 2004

SummaryAspen wood (Populus tremula) as sawdust was chemically modified through a two-step procedure: esterification with maleic anhydride and subsequent oligoesterification with glycidyl methacrylate and maleic anhydride. Simplified techniques consisting of impregnation by immersion followed by thermal treatment using conventional or microwave heating were employed. Chemical analyses and infra-red spectroscopy showed some differences in the chemical composition and structure of the resulting oligoesterified wood depending on the synthesis technique. However, the thermoplastic properties, clearly revealed by thermomechanical analysis, were quite similar and comparable to those exhibited by the oligoesterified wood resultingviaclassical synthesis. Moreover, similar degrees of chemical modification were obtained for a significantly shorter duration of the process when microwave heating was employed instead of conventional heating.