bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matricellular protein SPARC is translocated to the nuclei of immortalized murine lens epithelial cells
Authors: Yan Qi , Weaver Matt , Perdue Nikole , Sage E. Helene 
Published: November 2004

AbstractThe matricellular glycoprotein, secreted protein acidic and rich in cysteine (SPARC), has complex biological activities and is important for lens epithelial cell function and regulation of cataract formation. To understand how SPARC influences lens epithelial cell activity and homeostasis, we have studied the subcellular distribution of SPARC in murine lens epithelial cells in vitro. We demonstrate that endogenous SPARC is located in the cytoplasm of either quiescent or dividing lens epithelial cells in culture. However, cytoplasmic SPARC was translocated into the nuclei of immortalized lens epithelial cells upon a significant reduction of intracellular SPARC in these cells. Recombinant human (rh) SPARC added to the culture media was quickly and efficiently internalized into the cytosol of SPARC‐null lens epithelial cells. Moreover, cytoplasmic rhSPARC was also translocated into the nucleus after exogenous rhSPARC was removed from the culture media. The translocation of SPARC into the nucleus was therefore triggered by the reduction of SPARC protein normally available to the cells. A mouse SPARC–EGFP chimeric fusion protein (70 kDa) was expressed in lens epithelial cells and 293‐EBNA cells, and was observed both in the cytoplasm and culture medium, but not in the nucleus. SPARC does not appear to have a strong nuclear localization sequence. Alternatively, SPARC might pass through the nuclear pore complex by passive diffusion. SPARC therefore functions not only as an extracellular protein but also potentially as an intracellular protein to influence cellular activities and homeostasis. © 2004 Wiley‐Liss, Inc.
Different cation sensitivities and binding site domains of Na+–Ca2+–K+ and Na+–Ca2+ exchangers
Authors: Uehara Akira , Iwamoto Takahiro , Kita Satomi , Shioya Takao , Yasukochi Midori , Nakamura Yuki , Imanaga Issei 
Published: November 2004

AbstractWe examined inhibitory effects of external multivalent cations Ni2+, Co2+, Cd2+, La3+, Mg2+, and Mn2+ on reverse‐mode exchange of the K+‐dependent Na+/Ca2+ exchanger NCKX2 and the K+‐independent exchanger NCX1 expressed in CCL‐39 cells by measuring the rate of Ca2+ uptake with radioisotope tracer and electrophysiological techniques. The apparent affinities for block of Ca2+ uptake by multivalent cations was higher in NCKX2 than NCX1, and the rank order of inhibitory potencies among these cations was different. Additional experiments also showed that external Li+ stimulated reverse‐mode exchange by NCX1, but not NCKX2 in the presence of 5 mM K+. Thus, both exchangers exhibited differential sensitivities to not only K+ but also many other external cations. We attempted to locate the putative binding sites within the α motifs for multivalent cations by site‐directed mutagenesis experiments. The cation affinities of NCKX2 were altered by mutations of amino acid residues in the α‐1 motif, but not by mutations in the α‐2 motif. These results contrast with those for NCX1 where mutations in both α‐1 and α‐2 motifs have been shown previously to affect cation affinities. Susceptibility tests with sulfhydryl alkylating agents suggested that the α‐1 and α‐2 motifs are situated extracellularly and intracellularly, respectively, in both exchangers. A topological model is proposed in which the extracellular‐facing α‐1 motif forms an external cation binding site that includes key residues N203, G207C, and I209 in NCKX2, while both α‐1 and α‐2 motifs together form the binding sites in NCX1. © 2004 Wiley‐Liss, Inc.
Skeletal development of Macrochelys temminckii (Reptilia: Testudines: Chelydridae)
Authors: Sheil Christopher A. 
Published: November 2004

AbstractFew descriptions of the development and sequence of chondrification and ossification of the entire skeleton of turtles exist, particularly compared to other groups of reptiles. In this study, the embryonic skeleton and its ontogenesis are described for the Alligator Snapping Turtle, Macrochelys temminckii (Chelydridae). Morphological descriptions utilize cleared and double‐stained embryonic specimens and form the basis of comparison of the ontogenesis of the skeleton between this species and its extant sister taxon, Chelydra serpentina. The embryonic chondrocranium, as well as the sequences of formation and ossification of the entire skeleton, are compared between these closely related species, and afford a unique opportunity to examine differences in their patterns of skeletal formation. In M. temminckii, the first elements to ossify (Stage 17) are associated with the dermatocranium and upper jaw, followed by elements of the palate, lower jaw, and long bones of the limbs. In both species the majority of endochondral braincase elements (prootic, opisthotic, supraoccipital, and exoccipital) ossify after the majority of dermal elements of the skull. The sequences of formation of the chondral primordia of the limb elements, as well as ossification of autopodial elements, are generally congruent between these species. J. Morphol. 263:71–106, 2005. © 2004 Wiley‐Liss, Inc.
Simultaneous detection of DNA synthesis, activation and cytokine secretion in collagen II (250–270)‐activated T lymphocytes by flow cytometry
Authors: Zhu Ping , Li Xueyi , Ding Jin , Fan Chunmei , Wang Yanhong , Wang Hongkun , Chen Zhinan 
Published: November 2004

AbstractT cell activation and secretion of cytokines from activated peripheral blood mononuclear cells (PBMC) in culture have traditionally been measured by 3H‐thymidine incorporation for assessment of cell proliferation. However, this method has many disadvantages that limit its usage in analyzing antigen‐specific T responses, because of the low specific frequencies of the cells. Collagen II (250–270) may be an important autoantigen involved in the pathology of rheumatoid arthritis (RA). To further study the specific T cells response to CII 250–270, we developed an improved method for measuring lymphocyte proliferation and activation, and intracellular cytokine production, by flow cytometry at the single cell level. BrdU, an analog of thymidine, was incorporated into cellular DNA as a marker of individual cell proliferation. The cells were fixed and permeabilized, and a monoclonal antibody against BrdU conjugated with a fluorescent dye was used to measure BrdU incorporation. A Tris staining technique for the simultaneous determination of cell surface activation markers (CD69 or CD25) and intracellular cytokine production was also used and the parameters were assessed by 3‐color flow cytometry. Optimal conditions were selected to improve the sensitivity and specificity of the assays. This method allowed simultaneous detection of lymphocytic DNA synthesis, phenotype analysis and cytokine production at the single cell level, and thus it may be a useful tool for analyzing immune responses.
Comparing quality of care in non‐profit and for‐profit nursing homes: a process perspective
Authors: Chesteen Susan , Helgheim Berit , Randall Taylor , Wardell Don 
Published: November 2004

AbstractUsing data from a sample of nursing homes, this paper uses an operations centric approach to test the economic hypothesis asserting that quality in non‐profit healthcare entities will exceed quality in for‐profit counterparts [Arrow, K., 1963. Uncertainty and welfare economics of medical care. The American Economic Review, 5, 941–973]. For‐profit healthcare entities face an inherent conflict between providing profits to investors and health welfare to patients. Thus, non‐profit entities exist as a signal and evidence of higher quality services. To date, research examining differences in quality between for‐profit and non‐profit nursing homes has focused on a direct link between outcome quality and non‐profit status. These studies have produced inconclusive or mixed results. We argue that non‐profit or for‐profit status and outcome quality are linked via two intermediate factors, namely process quality and input quality. Consistent with many prior studies, we report no direct link between non‐profit status and outcome quality. However, we report that process quality is indeed higher at non‐profit nursing homes than for‐profit nursing homes, but that input quality is lower. We also examine the association between outcome quality with process and input quality. We report that different aspects of process quality are tied to better outcome quality, but report several notable exceptions. This research provides support for Arrow's hypothesis at the process level and gives insights into the link between process quality, input quality and outcome quality in the nursing home environment.
*-REPRESENTATION TYPE OF *-DOUBLES OF FINITE-DIMENSIONAL ALGEBRAS
Authors: Mazorchuk Volodymyr , Turowska Lyudmila 
Published: November 2004

AbstractWe determine when the $*$-double of a finite-dimensional complex algebra is $*$-finite, $*$-tame and $*$-wild.AMS 2000 Mathematics subject classification: Primary 46K10; 16G60
The intestinal anti‐inflammatory effect of quercitrin is associated with an inhibition in iNOS expression
Authors: Camuesco Desiree , Comalada Monica , Rodríguez‐Cabezas M Elena , Nieto Ana , Lorente Maria D , Concha Angel , Zarzuelo Antonio , Gálvez Julio 
Published: November 2004

Quercitrin, 3‐rhamnosylquercetin, is a bioflavonoid with antioxidant properties, which exerts anti‐inflammatory activity in experimental colitis. In the present study, different in vivo experiments were performed in order to evaluate the mechanisms of action involved in this effect, with special attention to its effects on proinflammatory mediators, including nitric oxide (NO).
Experimental colitis was induced in female Wistar rats by incorporation of dextran sodium sulfate (DSS) in drinking water. Oral treatment of quercitrin (1 or 5 mg kg−1 day−1) to colitic rats ameliorated the evolution of the inflammatory process induced when administered in a preventative dosing protocol. When quercitrin (1 mg kg−1 day−1) was administered on established colitis, it facilitated the recovery of the inflamed mucosa.
The beneficial effects exerted by quercitrin were evidenced both histologically and biochemically, and were associated with an improvement in the colonic oxidative status, altered as a consequence of the colonic insult induced by DSS. In addition, a reduction of colonic NO synthase activity was observed, probably related to a decreased expression in the inducible form of the enzyme via downregulation in the colonic activity of the nuclear factor‐κB.
Immunohistochemical studies showed that quercitrin treatment reduced macrophage and granulocyte infiltration in the inflamed tissue.

British Journal of Pharmacology (2004) 143, 908–918. doi:10.1038/sj.bjp.0705941
Modulation of voltage‐gated channel currents by harmaline and harmane
Authors: Splettstoesser Frank , Bonnet Udo , Wiemann Martin , Bingmann Dieter , Büsselberg Dietrich 
Published: November 2004

Harmala alkaloids are endogenous substances, which are involved in neurodegenerative disorders such as M. Parkinson, but some of them also have neuroprotective effects in the nervous system.
While several sites of action at the cellular level (e.g. benzodiazepine receptors, 5‐HT and GABAA receptors) have been identified, there is no report on how harmala alkaloids interact with voltage‐gated membrane channels.
The aim of this study was to investigate the effects of harmaline and harmane on voltage‐activated calcium‐ (ICa(V)), sodium‐ (INa(V)) and potassium (IK(V))‐channel currents, using the whole‐cell patch‐clamp method with cultured dorsal root ganglion neurones of 3‐week‐old rats. Currents were elicited by voltage steps from the holding potential to different command potentials.
Harmaline and harmane reduced ICa(V), INa(V) and IK(V) concentration‐dependent (10–500 μM) over the voltage range tested. ICa(V) was reduced with an IC50 of 100.6 μM for harmaline and by a significantly lower concentration of 75.8 μM (P<0.001, t‐test) for harmane. The Hill coefficient was close to 1. Threshold concentration was around 10 μM for both substances.
The steady state of inhibition of ICa(V) by harmaline or harmane was reached within several minutes. The action was not use dependent and at least partly reversible.
It was mainly due to a reduction in the sustained calcium channel current (ICa(L+N)), while the transient voltage‐gated calcium channel current (ICa(T)) was only partially affected.
We conclude that harmaline and harmane are modulators of ICa(V) in vitro. This might be related to their neuroprotective effects.

British Journal of Pharmacology (2005) 144, 52–58. doi:10.1038/sj.bjp.0706024
A novel member of the GCN5-related N-acetyltransferase superfamily from Caenorhabditis elegans preferentially catalyses the N-acetylation of thialysine [S-(2-aminoethyl)-L-cysteine]
Authors: ABO-DALO Benjamin , NDJONKA Dieudonne , PINNEN Francesco , LIEBAU Eva , LÜERSEN Kai 
Published: November 2004

The putative diamine N-acetyltransferase D2023.4 has been cloned from the model nematode Caenorhabditis elegans. The 483 bp open reading frame of the cDNA encodes a deduced polypeptide of 18.6 kDa. Accordingly, the recombinantly expressed His6-tagged protein forms an enzymically active homodimer with a molecular mass of approx. 44000 Da. The protein belongs to the GNAT (GCN5-related N-acetyltransferase) superfamily, and its amino acid sequence exhibits considerable similarity to mammalian spermidine/spermine-N1-acetyltransferases. However, neither the polyamines spermidine and spermine nor the diamines putrescine and cadaverine were efficiently acetylated by the protein. The smaller diamines diaminopropane and ethylenediamine, as well as L-lysine, represent better substrates, but, surprisingly, the enzyme most efficiently catalyses the N-acetylation of amino acids analogous with L-lysine. As determined by the kcat/Km values, the C. elegans N-acetyltransferase prefers thialysine [S-(2-aminoethyl)-L-cysteine], followed by O-(2-aminoethyl)-L-serine and S-(2-aminoethyl)-D,L-homocysteine. Reversed-phase HPLC and mass spectrometric analyses revealed that N-acetylation of L-lysine and L-thialysine occurs exclusively at the amino moiety of the side chain. Remarkably, heterologous expression of C. elegans N-acetyltransferase D2023.4 in Escherichia coli, which does not possess a homologous gene, results in a pronounced resistance against the anti-metabolite thialysine. Furthermore, C. elegans N-acetyltransferase D2023.4 exhibits the highest homology with a number of GNATs found in numerous genomes from bacteria to mammals that have not been biochemically characterized so far, suggesting a novel group of GNAT enzymes closely related to spermidine/spermine-N1-acetyltransferase, but with a distinct substrate specificity. Taken together, we propose to name the enzyme ‘thialysine Nε-acetyltransferase’.
Spermidine/spermine-N1-acetyltransferase-2 (SSAT2) acetylates thialysine and is not involved in polyamine metabolism
Authors: COLEMAN Catherine S. , STANLEY Bruce A. , JONES A. Daniel , PEGG Anthony E. 
Published: November 2004

Spermidine/spermine-N1-acetyltransferase (SSAT1) is a short-lived polyamine catabolic enzyme inducible by polyamines and polyamine analogues. Induction of SSAT1 plays an important role in polyamine homoeostasis, since the N1-acetylated polyamines can be excreted or oxidized by acetylpolyamine oxidase. We have purified a recombinant human acetyltransferase (SSAT2) that shares 45% identity and 61% homology with human SSAT1, but is only distally related to other known members of the GNAT (GCN5-related N-acetyltransferase) family. Like SSAT1, SSAT2 is widely expressed, but did not turn over rapidly, and levels were unaffected by treatments with polyamine analogues. Despite similarity in sequence to SSAT1, polyamines were found to be poor substrates of purified SSAT2, having Km values in the low millimolar range and kcat values of &lt;0.01 s−1. The kcat/Km values for spermine and spermidine for SSAT2 were &lt;0.0003% those of SSAT1. Expression of SSAT2 in NIH-3T3 cells was not detrimental to growth, and did not reduce polyamine content or increase acetylpolyamines. These results indicate that SSAT2 is not a polyamine catabolic enzyme, and that polyamines are unlikely to be its natural intracellular substrates. A promising candidate for the physiological substrate of SSAT2 is thialysine [S-(2-aminoethyl)-L-cysteine], which is acetylated predominantly at the ε-amino group with Km and kcat values of 290 μM and 5.2 s−1. Thialysine is a naturally occurring modified amino acid that can undergo metabolism to form cyclic ketimine derivatives found in the brain and as urinary metabolites, which can undergo further reaction to form antioxidants. SSAT2 should be renamed ‘thialysine Nε-acetyltransferase’, and may regulate this pathway.
A crustacean Ca2+-binding protein with a glutamate-rich sequence promotes CaCO3 crystallization
Authors: ENDO Hirotoshi , TAKAGI Yasuaki , OZAKI Noriaki , KOGURE Toshihiro , WATANABE Toshiki 
Published: November 2004

The DD4 mRNA of the penaeid prawn Penaeus japonicus was shown previously to be expressed in the epidermis adjacent to the exoskeleton specifically during the post-moult period, when calcification of the exoskeleton took place. The encoded protein possessed a Ca2+-binding site, suggesting its involvement in the calcification of the exoskeleton. In the present study, an additional ORF (open reading frame) of 289 amino acids was identified at the 5′ end of the previous ORF. The newly identified part of the encoded protein included a region of approx. 120 amino acids that was highly rich in glutamate residues, and contained one or more Ca2+-binding sites. In an immunohistochemical study, signals were detected within calcified regions in the endocuticular layer of the exoskeleton. Bacterially expressed partial segments of the protein induced CaCO3 crystallization in vitro. Finally, a reverse transcription-PCR study showed that the expression was limited to an early part of the post-moult period, preceding significant calcification of the exoskeleton. These observations argue for the possibility that the encoded protein, renamed crustocalcin (CCN), promotes formation of CaCO3 crystals in the exoskeleton by inducing nucleation.
Mechanisms of Naringenin‐induced Apoptotic Cascade in Cancer Cells: Involvement of Estrogen Receptor a and ß Signalling
Authors: Totta Pierangela , Acconcia Filippo , Leone Stefano , Cardillo Irene , Marino Maria 
Published: November 2004

AbstractThe flavanone naringenin (Nar), especially abundant in the Mediterranean diet, is reported to have anti‐proliferative effects in many cancer cell lines. Antioxidant activities, kinase and glucose uptake inhibition have been proposed as molecular mechanisms for these effects. In addition, an anti‐estrogenic activity has been observed but, at the present, it is poorly understood whether this latter activity could play a role in the Nar anti‐tumoral effects. Here, we tested the ability of Nar to activate a specific, rapid signal transduction pathway committed to the generation of an apoptotic cascade in the presence of one of the two estrogen receptor (ER) isoforms (i.e., ERα or ERβ). Cancer cells containing transfected (human cervix epitheloid carcinoma HeLa cells) or endogenous ERα (human hepatoma HepG2 cells) or ERβ (human colon adenocarcinoma DLD‐1 cells) were used. Our results show that Nar exerts an anti‐proliferative effect only in the presence of ERα or ERβ. Moreover, Nar stimulation induces the activation of p38/MAPK leading to the pro‐apoptotic caspase‐3 activation and to the poly(ADP‐ribose) polymerase cleavage in all cancer cell lines considered. Notably, Nar shows an anti‐estrogenic effect only in ERα containing cells; whereas in ERβ containing cells, Nar mimics the 17β‐estradiol effects. These findings indicate new steps in the mechanism underlying ER‐dependent anti‐proliferative effects of Nar suggesting new potential chemopreventive actions of flavonoids on cancer growth. IUBMB Life, 56: 491‐499, 2004
Emerging Role of P53, Bcl‐2 and Telomerase Activity in Egyptian Breast Cancer Patients
Authors: Swellam Menha , Ismail Manal , Eissa Sanaa , Hamdy Mohamed , Mokhtar Nadia 
Published: November 2004

AbstractApoptotic cell death represents an important mechanism for the precise regulation of cell numbers, and a defense mechanism against tumor cells. Both bcl‐2 and mutant p53 gene products have been involved in apoptotic pathways. On the other hand, cell proliferation capacity and tumorgenesis have been controlled by telomerase. The purpose of our study is to assess the prognostic significance of additional markers implicated in apoptosis and tumorgenesis. Fifty‐one fresh tissue samples of primary breast carcinoma and 26 tissue samples of benign breast lesions were included in this study. Expression of bcl‐2 in cell lysates and mutant p53 protein in nuclear fraction were measured by Oncogene Science EIA procedures. Telomerase activity was analyzed using the Telomerase‐PCR‐ELISA based on the TRAP (telomerase repeat amplification protocol) method. On the same specimens, steroid hormone receptors (ER and PgR) were measured in cytosol fraction using Abbott EIA assays. In addition, information regarding surgical‐pathological features of the tumor was obtained. Univariate and Multivariate analysis was done to identify variables predictive of poor prognosis. Significant expression of bcl‐2, mutant p53 proteins and relative telomerase activity were observed in malignant cases when compared to benign ones. Univariate analysis revealed significant association in the level of both mutant p53 and relative telomerase activity with tumor size and disease recurrence. Moreover, telomerase activity was significantly expressed in late stages than early ones. Multivariate analysis revealed that bcl‐2, mutant p53, telomerase activity, PgR and age were independent prognostic factors. Among a panel of molecular genetic factors investigated, mutant p53 and relative telomerase activity were strongly associated with disease recurrence; hence they exert a significant prognostic role in breast cancer. IUBMB Life, 56: 483‐490, 2004
FULL QCD ON APE100 MACHINES
Authors: ANTONELLI STEFANO , BELLACCI MARCO , DONINI ANDREA , SARNO RENATA 
Published: November 2004

We present the first tests and results from a study of QCD with two flavours of dynamical Wilson fermions using the Hybrid Monte Carlo Algorithm (HMCA) on APE100 machines. The simulations have been performed on 64 lattice for the pure gauge HMCA and on 84, 123×32 lattices for full QCD configurations. We discuss the inversion algorithm for the fermionic operator, the methods used to overcome the problems arising using a 32 bit machine and the implementation of a new random number generator for APE100 machines. We propose different scenarios for the simulation of physical observables, with respect to the memory capacity and speed of different APE100 configurations.
DESIGN AND SIMULATION OF THE ON-LINE TRIGGER AND RECONSTRUCTION FARM FOR THE HERA-B EXPERIMENT
Authors: LEGRAND I.C. , GENSCH U. , LEICH H. , WEGNER P. 
Published: November 2004

The common third level trigger and forth level reconstruction farm for the future HERA-B experiment will have to perform full on-line event reconstruction and calibration for an expected input rate of 2000 events/s. More than a hundred powerful RISC processors connected in a network capable of distributing several hundreds of MB/s with low latency are likely to be necessary for this task. Proper simulation of the real time multi-processor systems is central for an optimal design (hardware and software protocol) of a scalable and flexible parallel data processing architecture. A discrete event, process oriented simulation developed in concurrent μC++ is used as a framework for modelling and evaluating different farm architectures. An object oriented graphic interface to the simulation allows the monitoring of various features and provides an easier way to optimize the system.