bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of the laminated pattern of the chick tectum opticum
Authors: Scicolone G. , Pereyra‐Alfonso S. , Brusco A. , Saavedra J. Pecci , Flores V.
Published: July 2002

Several ontogenetic studies have been devoted to the structural organization of the developing tectum opticum. They disagree in many respects because they are based on histological preparations performed with differently oriented planes of section. According to our results the differences found in the literature mainly result from the fact that the developmental gradient axis undergoes remarkable positional changes with respect to both optic lobe and neural tube longitudinal anatomical axes during the early stages of development. The present work is a dynamic description of the tectum opticum lamination based on sections coinciding with the developmental gradient. Since this latter displays a curved disposition, several slightly modified planes of section had to be used to obtain a complete picture along the developmental gradient.

The development of the tectal architecture proceeds from a relatively simple organization through increasingly complex multilaminated patterns. A dynamic interpretation of successive images of a particular region observed at increasing developmental stages or of images observed at a particular stage along the entire length of the developmental gradient axis, allows us to propose that embryonic laminae are only transient spatial arrangements of cells actively migrating from the sites where they were generated to those where they will definitively reside. These considerations led us to define a nomenclature that establishes clear correlations between the early transient organizations and the definitive one of the fully developed optic tectum. This type of nomenclature could be usefully applied to describe dynamically the development of structures displaying multilaminated patterns such as other cortical zones of the central nervous system.
Light‐induced stimulation of carbonic anhydrase activity in pea thylakoids
Authors: Moskvin Oleg V , Ivanov Boris N , Ignatova Lyudmila K , Kollmeier Michelle A
Published: July 2002

Stimulation of the bicarbonate dehydration reaction in thylakoid suspension under conditions of saturating light at pH 7.6–8.0 was discovered. This effect was inhibited by nigericin or the lipophilic carbonic anhydrase (CA) inhibitor ethoxyzolamide (EZ), but not by the hydrophilic CA inhibitor, acetazolamide. It was shown that the action of EZ is not caused by an uncoupling effect. It was concluded that thylakoid CA is the enzyme utilizing the light‐generated proton gradient across the thylakoid membrane thus facilitating the production of CO2from HCO3−and that this enzyme is covered from the stroma side of thylakoids by a lipid barrier.
From BRCA1 to RAP1: a widespread BRCT module closely associated with DNA repair
Authors: Callebaut Isabelle , Mornon Jean-Paul
Published: July 2002

Inherited mutations in BRCA1 predispose to breast and ovarian cancer, but the biological function of the BRCA1 protein has remained largely elusive. The recent correspondence of Koonin et al. [Koonin, E.V., Altschul, S.F. and Bork, P. (1996) Nature Genet. 13, 266–267] has emphasized the potential importance of the BRCA1 C‐terminal region for BRCA1‐mediated breast cancer suppression, as this domain shows similarities with the C‐terminal regions of a p53‐binding protein (53BP1), the yeast RAD9 protein involved in DNA repair, and two uncharacterized, hypothetical proteins (KIAA0170 and SPAC19G10.7). The highlighted domain has been suggested to be the result of an internal duplication, each of the tandem domains being designated as a ‘BRCT domain’ (for BRCA1 C‐terminus). Sequence analysis using hydrophobic cluster analysis reveals here the presence of 50 copies of the BRCT domain in 23 different proteins, including, in addition to BRCA1, 53BP1 and RAD9, XRCC1, RAD4, Ect2, REV1, Crb2, RAP1, terminal deoxynucleotidyltransferases (TdT) and three eukaryotic DNA ligases. Most of these proteins are known to be involved in DNA repair. The BRCT domain is not limited to the C‐termini of protein sequences and can be found in multiple copies or in a single copy as in RAP1 and TdT, suggesting that it could well constitute an autonomous folding unit of approx. 90–100 amino acids.
NMR structural characterization of the CDK inhibitor p19INK4d
Authors: Kalus Wenzel , Baumgartner Roland , Renner Christian , Noegel Angelika , Chan Francis Ka Ming , Winoto Astar , Holak Tad A
Published: July 2002

p19INK4dis a 165 amino acid protein that belongs to the INK4 family of CDK4 and CDK6 inhibitors. Assignments of1H,15N and13C resonances have enabled the determination of the secondary structure of the protein which is largely α‐helical (residues 14–18, 21–29, 54–62, 77–83, 87–95, 110–116, 120–128, 142–148 and 152–160). The protein comprises five 32‐amino acid ankyrin‐like repeats; each ankyrin repeat contains a helix‐β‐turn‐helix core. The exception is the second ankyrin repeat, which lacks the first helix. All β‐turns have a central glycine residue flanked by two residues in β‐conformations. There is also a high conservation of Ala at position 8 in the first helix and Leu‐Leu(Val) at positions 17–18 of the second helix in all ankyrin repeats of p19. The location of the helix‐turn‐helix segments found in p19 should be general for all other members of the INK4 family, including, for example, a homologous tumor suppressor p16INK4a.1H‐15N heteronuclear steady‐state NOE measurements on p19 indicate that most of the backbone of p19INK4dexists in a well defined structure of limited conformational flexibility on the nano‐ to picosecond time scale.
Biosynthesis of ketocarotenoids in transgenic cyanobacteria expressing the algal gene for β‐C‐4‐oxygenase,crtO
Authors: Harker Mark , Hirschberg Joseph
Published: July 2002

© 1997 Federation of European Biochemical Societies.
Alcohol dehydrogenase of human and rat blood vessels
Authors: Allali-Hassani Abdellah , Martı́nez Susana E , Peralba Josep M , Vaglenova Julia , Vidal Francesc , Richart Cristóbal , Farrés Jaume , Parés Xavier
Published: July 2002

© 1997 Federation of European Biochemical Societies.
Comparison of lipid vesicle fusion induced by the putative fusion peptide of fertilin (a protein active in sperm‐egg fusion) and the NH2‐terminal domain of the HIV2 gp41
Authors: Martin Isabelle , Ruysschaert Jean-Marie
Published: July 2002

A peptide representing a putative fusion domain of fertilin, a sperm surface protein involved in sperm‐egg fusion was synthesized. Its interaction with model membranes was characterized and compared with that of a synthetic peptide representing the fusion peptide of HIV‐2rod gp41. The fertilin fusion peptide interaction with lipid vesicles is dependent upon the presence of negatively charged lipids in the membrane. Its fusogenic activity does not require PE and is not inhibited by addition of lysolecithin in the medium. These conditions are quite opposite to those obtained with the HIV2 peptide and suggest that the lipid mixing mediated by the two peptides corresponds to two different molecular mechanisms.
Function of the repeated sequence in the 3′ flanking region of theEscherichia colirnpBgene on transcription termination and RNA processing
Authors: Kim Semi , Lee Younghoon
Published: July 2002

The 3′ flanking region of theEscherichia colirnpBgene‐encoding M1 RNA, the RNA component of RNase P, contains a 113 bp repeated sequence. This sequence, successively reiterating 3.5 times, includes the region for intrinsic termination. In vivo termination of transcription occurs mostly at the first terminator (T1). Analysis of deletions at the 3′ flanking region revealed that the second terminator (T2) and third (T3) are functional in vivo and that the sequences preceding the region coding for an RNA‐terminator hairpin and U‐rich 3′ tail are essential for efficient termination. Transcripts terminating at T2 and T3 were also processed at the 3′ end in a manner similar to those terminating at T1.
Reduction of thymine hydroperoxide by phospholipid hydroperoxide glutathione peroxidase and glutathione transferases
Authors: Bao Yongping , Jemth Per , Mannervik Bengt , Williamson Gary
Published: July 2002

Thymine hydroperoxide (5‐hydroperoxymethyluracil), a model compound representing products of oxidative damage to DNA, is a substrate for glutathione peroxidase and some isoforms of glutathione transferase. In this paper, we show that selenium‐dependent human phospholipid hydroperoxide glutathione peroxidase (Se‐PHGPx) exhibits about four orders of magnitude higher activity on thymine hydroperoxide than that of other human enzymes such as selenium‐dependent glutathione peroxidase and various representatives of glutathione transferases. The results indicate that Se‐PHGPx may be an important enzyme in repairing oxidatively damaged DNA.
HIV‐1 gp120 glycoprotein affects the astrocyte control of extracellular glutamate by both inhibiting the uptake and stimulating the release of the amino acid
Authors: Vesce Sabino , Bezzi Paola , Rossi Daniela , Meldolesi Jacopo , Volterra Andrea
Published: July 2002

The mechanisms of HIV‐1 neurotoxicity remain still undefined although the induction of signalling events and a modest inhibition of glutamate uptake induced by the envelope glycoprotein, gp120, have called attention to astrocytes. Here we demonstrate that the levels at which the viral glycoprotein affects glutamate homeostasis of astrocyte cultures are at least two: not only the inhibition of uptake, due to an effect at site(s) away from the transporters of the amino acid but also a slow stimulation of release. The combination of these two events accounts for a considerable steady increase of the extracellular concentration of the excitatory amino acid which could play an important role in the neurotoxicity often observed in AIDS patients.
The conformational preference of gramicidin channels is a function of lipid bilayer thickness1
Authors: Mobashery Niloufar , Nielsen Claus , Andersen Olaf S
Published: July 2002

In order to understand how the material properties of lipid bilayers could affect integral membrane protein function, we examined the effect of a hydrophobic mismatch on the structure and function of membrane‐spanning gramicidin channels. Changes in lipid bilayer thickness affect the conformational preference of membrane‐spanning gramicidin A (gA) channels (single–stranded [SS] dimers ↔ double‐stranded [DS] dimers) and induces an additional conductance state in the standard (SS) β6.3‐helical channel. These results provide experimental evidence for the importance of energetic coupling between the bilayer and imbedded inclusions.
Acylphosphate formation by the Menkes copper ATPase
Authors: Solioz Marc , Camakaris James
Published: July 2002

The Menkes ATPase is the product of theMNKgene, defective in some inherited human disorders of copper metabolism. We here show the formation of an acylphosphate intermediate by the murineMNKhomologue in membranes from normal and copper resistant Chinese hamster ovary cells. In the latter, fivefold higher levels of acylphosphate were formed. Challenging these cells with copper, which induces relocation of theMNKATPase from thetrans‐Golgi network to the plasma membrane, did not influence acylphosphate formation. The kinetics of phosphorylation, metal dependence, and sensitivity to inhibitors were investigated. The results show that theMNKATPase is an active P‐type ATPase and provide a direct functional test for this enzyme.
Involvement of a metalloprotease in the shedding of human neutrophil FcγRIIIB
Authors: Middelhoven P.J , Ager A , Roos D , Verhoeven A.J
Published: July 2002

FcγRIIIb is a glycosylphosphatidylinositol(GPI)‐anchored, low‐affinity IgG receptor, expressed exclusively on human neutrophils. Upon activation or apoptosis of neutrophils, FcγRIIIb is shed from the cell surface, but the enzyme(s) responsible for this process is (are) still unknown. Recently, metalloproteases have been suggested to mediate the shedding of cell surface proteins such as l‐selectin and TNF‐α. Using hydroxamic acid‐based inhibitors of this class of proteases (BB‐3103, Ro31‐9790), we have observed a clear inhibitory effect on FcγRIIIb shedding after PMA stimulation of neutrophils or induction of apoptosis. These inhibitors did not affect PMA‐induced degranulation or superoxide generation.
Release of cytochrome c and decrease of cytochrome c oxidase in Bax‐expressing yeast cells, and prevention of these effects by coexpression of Bcl‐xL
Authors: Manon Stéphen , Chaudhuri Bhabatosh , Guérin Martine
Published: July 2002

The characteristics of mitochondria of yeast cells expressing the pro‐apoptotic gene Bax or coexpressing Bax and the anti‐apoptotic gene Bcl‐xL have been investigated in whole cells, isolated mitochondria and permeabilized spheroplasts. It is found that Bax‐induced growth arrest of yeast cells is related to two defects in the respiratory chain: (i) a decrease in the amount of cytochrome c oxidase, the terminal enzyme of the respiratory chain, and (ii) a dramatic increase in the release of cytochrome c to the cytosol. Other components of the inner mitochondrial membrane (bc1 complex and F0F1‐ATPase) are unaffected. Coexpression of Bcl‐xL almost fully prevented the effect of Bax. Surprisingly, these results obtained in yeast parallel similar observations reported in mammalian cells.
Resveratrol, a remarkable inhibitor of ribonucleotide reductase
Authors: Fontecave Marc , Lepoivre Michel , Elleingand Eric , Gerez Catherine , Guittet Olivier
Published: July 2002

Resveratrol, a natural phytoalexin found in grapes, is well known for its presumed role in the prevention of heart disease, associated with red wine consumption. We show here that it is a remarkable inhibitor of ribonucleotide reductase and DNA synthesis in mammalian cells, which might have further applications as an antiproliferative or a cancer chemopreventive agent in humans.
β‐Carotene to zeaxanthin conversion in the rapid turnover of the D1 protein of photosystem II
Authors: Depka Brigitte , Jahns Peter , Trebst Achim
Published: July 2002

The carotenoid composition was investigated during enhanced D1 protein turnover inChlamydomonas reinhardtiiexposed to high light. After 2 h of high light there was no loss of the D1 protein yet. However, the β‐carotene content was significantly reduced. In parallel, an increase of the zeaxanthin content was found, which was higher than can be accounted for by the light‐induced de‐epoxidation of violaxanthin in the xanthophyll cycle reactions. We therefore assume that β‐carotene of photosystem II (PS II) is hydroxylated to zeaxanthin under high light stress. Inhibitors of carotene biosynthesis led to the loss of both PS II activity and D1 protein, indicating the requirement of β‐carotene synthesis for the reassembly of PS II in high light. Diuron blocked D1 protein as well as β‐carotene turnover. In the presence of chloramphenicol – which allows just one turnover of the D1 protein – 15% of the total β‐carotene was lost, calculated to be two β‐carotene.
Selective activation of G‐protein subtypes by vertebrate and invertebrate rhodopsins
Authors: Terakita Akihisa , Yamashita Takahiro , Tachibanaki Shuji , Shichida Yoshinori
Published: July 2002

We have quantitatively investigated specificities in activating G‐protein subtype by bovine and squid rhodopsins to examine whether or not the phototransduction cascade in each of the photoreceptor cells is determined by the colocalization of a large amount of G‐protein subtype (Gt or Gq). In contrast to the efficient activation of respective Gt and Gq, bovine and squid rhodopsins scarcely activated G‐protein counterparts. Exchange of α‐ and βγ‐subunits of Gt and Gq indicated the critical role of the α‐subunit in specific binding to respective rhodopsins. Thus the specific recognition of G‐protein subtype by each rhodopsin is a major mechanism in determining the phototransduction cascade.
Real‐time observation of acrosomal dispersal from mouse sperm using GFP as a marker protein
Authors: Nakanishi Tomoko , Ikawa Masahito , Yamada Shuichi , Parvinen Martti , Baba Tadashi , Nishimune Yoshitake , Okabe Masaru
Published: July 2002

We produced transgenic mouse lines that accumulate mutated green fluorescent protein (EGFP) in sperm acrosome, a membrane limited organelle overlying the nucleus. The sperm showed normal fertilizing ability and the integrity of their acrosome was easily examined in a non‐invasive manner by tracing the GFP in individual ‘live’ sperm with fluorescent microscopy. The time required for the dispersal of acrosomal contents was demonstrated to be approximately 3 s after the onset of acrosome reaction.
Novel enzymatic oxidation of Mn2+ to Mn3+ catalyzed by a fungal laccase
Authors: Höfer Christine , Schlosser Dietmar
Published: July 2002

Fungal laccases are extracellular multinuclear copper‐containing oxidases that have been proposed to be involved in ligninolysis and degradation of xenobiotics. Here, we show that an electrophoretically homogenous laccase preparation from the white rot fungus Trametes versicolor oxidized Mn2+ to Mn3+ in the presence of Na‐pyrophosphate, with a K
m value of 186 μM and a V
max value of 0.11 μmol/min/mg protein at the optimal pH (5.0) and a Na‐pyrophosphate concentration of 100 mM. The oxidation of Mn2+ involved concomitant reduction of the laccase type 1 copper site as usual for laccase reactions, thus providing the first evidence that laccase may directly utilize Mn2+ as a substrate.
Troglitazone inhibits angiotensin II‐induced extracellular signal‐regulated kinase 1/2 nuclear translocation and activation in vascular smooth muscle cells
Authors: Goetze Stephan , Xi Xiao-Ping , Graf Kristof , Fleck Eckart , Hsueh Willa A. , Law Ronald E.
Published: July 2002

The thiazolidinedione troglitazone inhibits angiotensin II‐induced extracellular signal‐regulated kinase 1/2 mitogen‐activated protein kinase activity in vascular smooth muscle cells. Activation of extracellular signal‐regulated kinase 1/2 by angiotensin II is a multistep process involving both its phosphorylation by mitogen‐activated protein kinase extracellular signal‐regulated kinase kinase in the cytoplasm and a subsequent translocation to the nucleus. The cytoplasmic activation of extracellular signal‐regulated kinase 1/2 in vascular smooth muscle cells proceeds through the protein kinase Cζ→mitogen‐activated protein kinase extracellular signal‐regulated kinase kinase→extracellular signal‐regulated kinase pathway. Troglitazone did not affect the angiotensin II‐induced activation of protein kinase Cζ or its downstream signaling kinases extracellular signal‐regulated kinase 1/2 in the cytosol. In contrast, angiotensin II‐induced activation of protein kinase Cζ and extracellular signal‐regulated kinase 1/2 in the nucleus were both inhibited by troglitazone. Nuclear translocation of extracellular signal‐regulated kinase 1/2 induced by angiotensin II was completely blocked by troglitazone. Protein kinase Cζ, however, did not translocate upon angiotensin II stimulation. Troglitazone, therefore, inhibits both angiotensin II‐induced nuclear translocation of extracellular signal‐regulated kinase 1/2 and the nuclear activity of its upstream signaling kinase protein kinase Cζ. Since extracellular signal‐regulated kinase 1/2 nuclear translocation may be a critical signaling step for multiple growth factors that stimulate vascular smooth muscle cells proliferation and migration, troglitazone may provide a new therapeutical approach for the prevention and treatment of atherosclerosis and restenosis.
Antagonistic effect of ganglioside GM1 and GM3 on the activity and conformation of sarcoplasmic reticulum Ca2+‐ATPase
Authors: Wang Yuling , Tsui Zhaochun , Yang Fuyu
Published: July 2002

It was found that rabbit skeletal muscle sarcoplasmic reticulum (SR) contained two main gangliosides: NeuNAcα 2→3 Galβ 1→4 Glcβ 1→1′ceramide (GM3) and Galβ 1→3 GalNAcβ 1→4(NeuNAcα 2→3) Galβ 1→4 Glcβ 1→1′ceramide (GM1), and that the most abundant ganglioside GM3 could positively modulate the SR Ca2+‐ATPase activity. In this paper, the effect of GM1 on Ca2+‐ATPase was further investigated and compared with that of GM3. The study demonstrates that GM1 has an opposite effect with respect to GM3 on the activity of SR Ca2+‐ATPase. Using assays, including intrinsic and time‐resolved fluorescence and fluorescence quenching, the conformational changes of SR Ca2+‐ATPase induced by GM1 and GM3 were compared. Obtained results indicate that GM1 could make the Ca2+‐ATPase molecules less compact in the hydrophilic domain but more compact in the hydrophobic domain, while GM3 makes the enzyme more compact in both the hydrophilic and hydrophobic domain. Homogeneous GM1 and GM3 with the same ceramide moiety had similar effects on SR Ca2+‐ATPase activities compared to their natural counterparts, suggesting that the carbohydrate chain may be the key moiety of the ganglioside molecule to be responsible for the difference of the effect on enzyme activity.
Effects of multiagent chemotherapy and independent risk factors in the treatment of high‐risk GTT —25 years experiences of KRI‐TRD
Authors: Kim S.J. , Bae S.N. , Kim J.H. , Kim C.T. , Han K.T. , Lee J.M. , Jung J.K.
Published: July 2002

A retrospective and comparative study of high‐risk gestational trophoblastic tumor (GTT) treated with different chemoregimen from 1971 to 1995 was performed and to find most effective chemotherapy regimen and independent risk factors.

Three hundred seven patients in scoring over 8 points in WHO classification were categorized into high‐risk group among 802 GTT cases received chemotherapy in the 2,418 GTD patients registered at KRI‐TRD (Korean Research Institute for Gestational Trophoblastic Disease), Catholic University Medical College in Korea. Study groups of multiagent combination chemotherapy in 227 patients of the high‐risk GTT were divided such as 49 cases of combination chemotherapy with MTX + folinic acid and Act‐D, 40 cases of MAC regimen, 42 cases of CHAMOCA regimen, and 96 cases of EMA/CO.

Initial tumor response according to hCG titer decrease was found in good response (log fall) 69.8%, of EMA /CO regimen group. On the other hand, good response was shown in only 24.5% of MTX + ACT‐D, 32.5% of MAC regimen, and 52.4%, of CHAMOCA regimen respectively.

Remission rate of EMA/CO regimen was 90.6% (87/96) and courses of chemotherapy until remission was 8.5 ± 2.2. However, remission rate of other regimens of MTX + Act‐D, MAC, and CHAMOCA were 63.3%, (31/49) 67.5% (27/40) and 76.2% (32/45) respectively, with 10.0 ± 4.0, 10.7 ± 4.3, 9.1 ± 3.9 chemotherapy courses respectively until remission. Therefore, EMA/CO regimen groups were found to have low drug toxicity, early remission and a low failure rate.

In the study of independent risk factors in the 165 cases of high‐risk gestational trophoblastic tumor patients received EMA/CO regimen, stepwise Coxs proportional hazard's regression of prognostic factors using multivariate analysis revealed tumor age, number of metastatic organs, metastatic site and inadequate previous chemotherapy. According to the performance of fitted logistic regression model, the prediction rate of death and survival was 80.5%.

Conclusions: The most effective chemotherapy to high‐risk GTT was EMA/CO regimen than other regimens. The following factors showed poor prognosis; 1) Tumor age is over 12 month, 2) more than 2 organs had metastatic lesion, 3) inadequate previous therapy that includes unplanned operation and inadequate previous chemotherapy.
The impact of human resource management practices on manufacturing performance
Authors: Jayaram Jayanth , Droge Cornelia , Vickery Shawnee K
Published: July 2002

A human resource management (HRM) analysis framework is proposed and tested using data from first tier suppliers to the Big 3 in North America. Relationships among underlying dimensions of human resource management practices and manufacturing performance are examined. The study found support for the proposed framework, suggesting that human resource management practices can be grouped into five distinct factors, four of which are associated with specific manufacturing competitive dimensions (quality, flexibility, cost and time). The remaining HRM factor is generic. The four priority‐specific HRM factors are strongly related to their respective manufacturing performance dimensions.
Developing breakthrough products: challenges and options for market assessment
Authors: Deszca Gene , Munro Hugh , Noori Hamid
Published: July 2002

Competitive pressures and market forces are augmenting the importance of product innovation as a source of competitive advantage. Key drivers underpinning market success have the capacity to develop the “right” products for the “right” customers, using the “right” channels, with a shorter development cycle than competitors. But when breakthrough products (BTPs) are involved, how do we sort out what is “right”? How do we identify customers' future requirements when the technology platforms are still unfolding, products are still in development and customers lack experience with the product? Traditional product development market research techniques are problematic since they assume the customer has historical experience with products similar to those being created. The objective of this paper is to raise the awareness of the OM community with the strengths and weaknesses of existing methodologies for developing and introducing innovative products to market. Further, it suggests promising future directions for both practice and research when BTPs are involved. This is important because of the central role OM plays in managing the success of the BTP development process.
Chondrocyte necrosis and apoptosis in impact damaged articular cartilage
Authors: Chen Chih‐Tung , Burton‐Wurster Nancy , Borden Caroline , Hueffer Karsten , Bloom Stephen E. , Lust George
Published: July 2002

A decrease in chondrocyte numbers is one characteristic of osteoarthritic cartilage. This decrease may be the result of apoptosis or other forms of cell death induced by mechanical damage. Furthermore, cell death may contribute to the structural and metabolic changes found in osteoarthritic cartilage. Therefore, we investigated cell viability and the mode of cell death in cartilage subjected to an increasing severity of impact loads expected to cause compositional damage and osteoarthritic‐like metabolic alterations. Canine cartilage explants were subjected to cyclic indentation impacts of 5 megapascals at 0.3 Hz for 0, 2, 20, and 120 min and then kept in culture for 2, 4, 48, and 144 h. Cell death was assessed by the TUNEL assay and by uptake of propidium iodide. Viable cells were detected by the ability to metabolize fluorescein diacetate. Nuclear morphology and ultrastructure of the cell were examined using Hoechst 33342 fluorescent staining and transmission electron microscopy (TEM). As controls for necrosis and apoptosis, cartilage was, respectively, frozen and thawed or incubated with mitomycin‐C, an apoptosis inducer. In cartilage that had been loaded for 2 h, 32% of the chondrocytes in the loaded core took up propidium iodide within 2 h after loading. Most of these were in the middle to superficial zones and reflected leaky cell membranes usually characteristic of necrosis. Less than 1% of these chondrocytes were positive in the TUNEL assay after 4 h. After additional culture for 2 days, however, the proportion of chondrocytes which were positive in the TUNEL assay reached 73%. A dose dependent response to duration of loading was detected with the TUNEL assay at this time. The TUNEL assay was not specific for apoptosis since 92% of chondrocytes in freeze/thawed cartilage were TUNEL positive. However, some cells with apoptotic bodies and chromatin condensation characteristic of apoptosis were found in the transition zone between necrotic and normal chondrocytes, but not in the superficial and upper zones, in impact damaged cartilage. We concluded that in this study, necrosis occurred first, followed by apoptosis. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
The extent of matrix damage and chondrocyte death in mechanically traumatized articular cartilage explants depends on rate of loading
Authors: Ewers B. J. , Dvoracek‐Driksna D. , Orth M. W. , Haut R. C.
Published: July 2002

Mechanical loads can lead to matrix damage and chondrocyte death in articular cartilage. This damage has been implicated in the pathogenesis of secondary osteoarthritis. Studies on cartilage explants with the attachment of underlying bone at high rates of loading have documented cell death adjacent to surface lesions. On the other hand, studies involving explants removed from bone at low rates of loading suggest no clear spatial association between cell death and matrix damage. The current study hypothesized that the observed differences in the distribution of cell death in these studies are attributed to the rate of loading. Ninety bovine cartilage explants were cultured for two days. Sixty explants were loaded in unconfined compression to 40 MPa in either a fast rate of loading experiment (∼900 MPa/s) or a low rate of loading experiment (40 MPa/s). The remaining 30 explants served as a control population. All explants were cultured for four days after loading. Matrix damage was assessed by measuring the total length and average depth of surface lesions and the release of glycosaminoglycans to the culture media. Explants were sectioned and stained with calcein and ethidium bromide homodimer to document the number of live and dead cells. Greater matrix damage was documented in explants subjected to a high rate of loading, compared to explants exposed to a low rate of loading. The high rate of loading experiments resulted in cell death adjacent to fissures, whereas more dead cells were observed in the low rate of loading experiments and a more diffuse distribution of dead cells was observed away from the fissures. In conclusion, this study indicated that the rate of loading can significantly affect the degree of matrix damage, the distribution of dead cells, and the amount of cell death in unconfined compression experiments on explants of articular cartilage. © 2001 Orthopaedic Research Society. Punlished by Elsevier Science Ltd. All rights reserved.
Effects of cholinergic depletion on evoked activity inthe cortex of young and aged rats
Authors: Herron Paul , Li Zhicheng , Schweitzer John B.
Published: July 2002

Degeneration of cholinergic neurons in the basal forebrain is a neural marker ofAlzheimers disease and is associated with perceptual and cognitive deficits. An idea that hasattracted scientific scutiny is that aging makes the brain more susceptible to neurodegenerativediseases such as Alzheimers. The purpose of this study was to compare the effects of the loss ofcholinergic input from nucleus basalis of Meynert on evoked activity in the posteromedial barrelsubfield of the somatosensory cortex in young (2–2.5 months) and aged (28–30 months) maleFisher hybrid rats. The mean firing rate and receptive fields of single neurons in the posteromedialbarrel subfield of the somatosensory cortex were examined after selective lesions of cholinergicneurons in the nucleus basalis of Meynert with an immunotoxin, IgG 192‐saporin.

Functional properties of single neurons in young animals were affected much moresignificantly by cholinergic depletion than those in aged animals. In cholinergic‐depleted younganimals, the mean firing rate of evoked activity and receptive field of posteromedial barrel subfieldneurons were significantly decreased. Cholinergic depletion caused a 14% decrease in evokedactivity and a 33% increase in receptive field size in young animals. The mean firing rate andreceptive field of single neurons were not affected by cholinergic depletion in aged animals. It isconcluded that functional properties of cortical sensory neurons in young animals are morevulnerable to cholinergic depletion than are those of aged animals and that cholinergic depletiondoes not further impact the properties of neurons exposed to the processes of aging.
Alcohol dependence and gender-role orientation
Authors: Möller-Leimkühler A.M. , Schwarz R. , Burtscheidt W. , Gaebel W.
Published: July 2002

Objective

The overall increase of female alcoholism is supposed to be associated with the change of the traditional female role, and it is especially seen as a consequence of role convergence or gender-role conflicts. The aim of the present pilot study is to explore whether the approach of gender-role orientation would be empirically useful in contributing to these hypotheses.

Method

One hundred twelve patients with alcohol dependence meeting DSM-III-R criteria were explored after detoxification; gender-role orientation was measured by a German version of the ‘Extended Personal Attributes Questionnaire’, categorising gender-role orientation into four subgroups: masculine, feminine, androgynous, and undifferentiated.

Results

In comparison with a population-based sample, there are significant differences in the distribution of the four subgroups of gender-role orientation, showing a predominance of the undifferentiated self-concept in the alcoholic sample (49%). Alcoholic females describe themselves as rather undifferentiated, and rather feminine than masculine. Low masculinity and low femininity, as well as high femininity, correlate positively with distress, depressiveness, social anxiety, insecurity and concomitant personality disorders.

Conclusion

Our data do not support the convergence hypothesis related to gender-role orientation, but support the traditional feminine self-concept as an unspecific risk factor for vulnerability. The question whether an undifferentiated self-concept could be a specific risk factor for alcoholism is discussed.
Ssri-related toxic serotonin syndrome: improvement by discontinuation of treatment and propranolol
Authors: Dursun SM , Burke JG , Nielsen F , Mlynik-Szmid A , Reveley MA
Published: July 2002

We report three cases in which toxic serotonin syndrome developed in relation to three different selective serotonin reuptake inhibitors (SSRI) (ie, fluoxetine, sertraline, paroxetine), and which all responded to the discontinuation of the SSRI and also to an additional propranolol treatment.
Improvement of cardiac output in patients with severe heart failure by use of ACE‐inhibitors combined with the AT1‐antagonist eprosartan
Authors: Gremmler B. , Kunert M. , Schleiting H. , Ulbricht L.J.
Published: July 2002

Background:

The efficacy of ACE‐inhibitor therapy is well documented in the treatment of chronic heart failure. As pharmacological mechanisms of ACE‐inhibition and angiotensin II AT1‐receptor‐antagonists differ, an additional positive effect concerning left ventricular function can be expected in combining both classes of drugs.

Methods:

Twenty patients (64.9 ± 8.5 years) with advanced chronic heart failure (NYHA class III) receiving long‐term medication with digitalis, diuretics and ACE‐inhibitors were randomized to either eprosartan (540 ± 96 mg/day) or placebo, according to a blinded protocol. Hemodynamic measurements by impedance cardiography were performed at baseline and after 8.85 ± 1.5 days of study medication treatment.

Results:

Additional treatment with eprosartan resulted in a higher cardiac output than in the control group (P < 0.05). While in the active treatment group cardiac output increased significantly from baseline (2.27–3.24 l/min, P = 0.039), there was no change in the control group.

Conclusions:

The additional treatment with the AT1‐receptor antagonist eprosartan, given to severe heart failure patients, who received digitalis, diuretics and ACE‐inhibitors, resulted in a beneficial effect by increasing cardiac output. This effect may be due to eprosartan's additional property of blocking the autocrine interaction of locally and not ACE‐generated angiotensin II with their respective vascular and myocardial AT1‐receptors as well as the influence on prejunctional AT1‐receptors located on sympathetic nerve terminals.
Risk stratification in middle‐aged patients with congestive heart failure: prospective comparison of the Heart Failure Survival Score (HFSS) and a simplified two‐variable model
Authors: Zugck Christian , Krüger Carsten , Kell Robert , Körber Sven , Schellberg Dieter , Kübler Wolfgang , Haass Markus
Published: July 2002

Aims:

The performance of a US‐American scoring system (Heart Failure Survival Score, HFSS) was prospectively evaluated in a sample of ambulatory patients with congestive heart failure (CHF). Additionally, it was investigated whether the HFSS might be simplified by assessment of the distance ambulated during a 6‐min walk test (6′WT) instead of determination of peak oxygen uptake (peakVO2).

Methods and Results:

In 208 middle‐aged CHF patients (age 54 ± 10 years, 82% male, NYHA class 2.3 ± 0.7; follow‐up 28 ± 14 months) the seven variables of the HFSS: CHF aetiology; heart rate; mean arterial pressure; serum sodium concentration; intraventricular conduction time; left ventricular ejection fraction (LVEF); and peakVO2, were determined. Additionally, a 6′WT was performed. The HFSS allowed discrimination between patients at low, medium and high risk, with mortality rates of 16, 39 and 50%, respectively. However, the prognostic power of the HFSS was not superior to a two‐variable model consisting only of LVEF and peakVO2. The areas under the receiver operating curves (AUC) for prediction of 1‐year survival were even higher for the two‐variable model (0.84 vs. 0.74,P< 0.05). Replacing peakVO2with 6′WT resulted in a similar AUC (0.83).

Conclusion:

The HFSS continued to predict survival when applied to this patient sample. However, the HFSS was inferior to a two‐variable model containing only LVEF and either peakVO2or 6′WT. As the 6′WT requires no sophisticated equipment, a simplified two‐variable model containing only LVEF and 6′WT may be more widely applicable, and is therefore recommended.
Angiotensin‐II type 1 receptor gene polymorphism and long‐term survival in patients with idiopathic congestive heart failure
Authors: Andersson Bert , Blange Irina , Sylvén Christer
Published: July 2002

Background:

It has been suggested that a genetic polymorphism in the angiotensin II type 1 receptor gene (ATRG) and the ACE gene DD genotype might have a synergistic influence on the risk of developing cardiovascular disease.

Aims:

To study the possible interaction between polymorphisms in the ACE gene and the ATRG, regarding survival and left ventricular function.

Methods:

Polymorphism of the two genes was studied in a population‐based cohort of 194 patients with idiopathic heart failure, recruited from the western part of Sweden 1985–1988. The patients were investigated by echocardiography. The survival status was checked during the 7‐year follow‐up period.

Results:

Although there was no statistically significant additive risk of the ATRG polymorphism, patients carrying the ACE gene DD genotype in combination with a C allele of the ATRG tended to have a poorer prognosis. DD + AA, OR 1.24 (95% CI 0.67–2.32, P = 0.49); DD + AC, OR 1.64 (95% CI 0.95–2.83, P = 0.08); DD + CC, OR 3.54 95% CI 0.78–16.1, P = 0.10); DD + AC/CC, OR 1.84 (95% CI 1.10–3.08, P = 0.02). Patients with the DD + AC/CC genotypes tended to have lower ejection fraction and increased left ventricular mass.

Conclusions:

There was a trend toward a worse prognosis in patients with the combination of a C‐allele in the ATRG and the ACE gene DD genotype, suggesting an interaction of these two genetic polymorophisms on disease severity.
Ile209 of Leishmania donovani xanthine phosphoribosyltransferase plays a key role in determining its purine base specificity
Authors: Patel Bhumi , Patel Dhaval , Pappachan Anju
Published: July 2021

Xanthine phosphoribosyltransferase (XPRT) and hypoxanthine‐guanine phosphoribosyltransferase (HGPRT) are purine salvaging enzymes of Leishmania donovani with distinct 6‐oxopurine specificities. LdXPRT phosphoribosylates xanthine, hypoxanthine, and guanine, with preference toward xanthine, whereas LdHGPRT phosphoribosylates only hypoxanthine and guanine. In our study, LdXPRT was used as a model to understand these purine base specificities. Mutating I209 to V, the conserved residue found in HGPRTs, reduced the affinity of LdXPRT for xanthine, converting it to an HGXPRT‐like enzyme. The Y208F mutation in the active site indicated that aromatic residue interactions with the purine ring are limited to pi‐pi binding forces and do not impart purine base specificity. Deleting the unique motif (L55‐Y82) of LdXPRT affected enzyme activity. Our studies established I209 as a key residue determining the 6‐oxopurine specificity of LdXPRT.
Raman Spectroscopic Characterization of Environmentally Friendly Binder Systems for Carbon‐Bonded Filters
Authors: Brehm Simon , Himcinschi Cameliu , Kraus Jakob , Bock-Seefeld Benjamin , Aneziris Christos , Kortus Jens
Published: July 2021

A contribution to the production of zero‐defect materials is the development of carbon‐bonded alumina foam filters for removing nonmetallic inclusions from molten metals. Herein, such filters containing various mixtures of Carbores P, lactose, and tannin as binder are investigated by Raman spectroscopy. The filter samples differ in whether or not they are fired and whether or not n‐Si is added to them. Raman measurements are also performed on samples of the individual binder substances, which have been preannealed at temperatures up to 1400 °C. The variation of the sp2 carbon cluster sizes due to the heat treatment is estimated using the intensity ratio of the D and G bands as determined from these measurements. The conversion of the samples from hydrogen‐rich amorphous carbon systems to nanocrystalline graphite is observed. The results show no significant differences between the binders in regard to the material properties that can be studied with Raman spectroscopy.
Reassembly of MXene Hydrogels into Flexible Films towards Compact and Ultrafast Supercapacitors
Authors: Wu Zhitan , Liu Xiaochen , Shang Tongxin , Deng Yaqian , Wang Ning , Dong Ximan , Zhao Juan , Chen Derong , Tao Ying , Yang Quan‐Hong
Published: July 2021

The freestanding MXene films are promising for compact energy storage ascribing to their high pseudocapacitance and density, yet the sluggish ion transport caused by the most densely packed structure severely hinders their rate capability. Here, a reassembly strategy for constructing freestanding and flexible MXene‐based film electrodes with a tunable porous structure is proposed, where the Ti3C2Tx microgels disassembled from 3D structured hydrogel are reassembled together with individual Ti3C2Tx nanosheets in different mass ratios to form a densely packed 3D network in microscale and a film morphology in macroscale. The space utilization of produced film can be maximized by a good balance of the density and porosity, resulting in a high volumetric capacitance of 736 F cm−3 at an ultrahigh scan rate of 2000 mV s−1. The fabricated supercapacitor yields a superior energy density of 40 Wh L−1 at a power density of 0.83 kW L−1, and an energy density of 21 Wh L−1 can be still maintained even when the power density reaches 41.5 kW L−1, which are the highest values reported to date for symmetric supercapacitors in aqueous electrolytes. More promisingly, the reassembled films can be used as electrodes of flexible supercapacitors, showing excellent flexibility and integrability.
Advances in Coaxial Additive Manufacturing and Applications
Authors: Rafiee Mohammad , Granier Floriane , Therriault Daniel
Published: July 2021

Coaxial additive manufacturing (AM) is an emerging technology involving the simultaneous deposition of two or more materials with a common longitudinal axis. It has the potential to overcome the disadvantages associated with conventional single‐material AM for the production of core‐shell or multi‐core‐shell multimaterial structures. The coaxial AM techniques can be classified into extrusion and material jetting technologies. The extrusion‐based technologies rely on the co‐extrusion of multiple materials through a coaxial nozzle whereas the material jetting technologies are based on the introduction of a high voltage electric field between a coaxial nozzle and a grounded collector plate. This review is aimed to provide a comprehensive overview of multimaterial coaxial AM, including the technologies, nozzle designs, materials, and applications. The advances in coaxial AM and the benefits of this novel technology in various fields are highlighted. For instance, in biomedicine coaxial AM offers an exciting alternative to single‐material bioprinting for the fabrication of bio‐scaffolds and vascular networks as well as for tissue engineering and cell encapsulations. Coaxial AM is also a subject of growing interest in the fields of flexible sensors, e‐textiles, and printed electronics. Perspectives on the limitations, existing challenges, opportunities, and future directions for further development are also provided.
Colorimetric Detection of Mechanical Deformation in Metals using Thin‐Film Mechanochromic Sensor
Authors: Bae Gijoon , Seo Minseok , Lee Sangjun , Bae Donghyun , Lee Myeongkyu
Published: July 2021

As metals form the backbone of many engineering structures including bridges and buildings, the detection of their mechanical deformation is of technological importance. Several optical techniques such as holographic interferometry, speckle interferometry, and digital image correlation have been developed to map the surface strains and displacements of various materials. However, these techniques have stringent requirements for stability and repeatability, which limit their application outside the laboratory. Herein, a colorimetric method for detecting mechanical deformation in metals based on the color change in an attached mechanochromic sensor is proposed. This study shows that a mechanically adaptable thin‐film sensor bonded to a block of metal can not only visualize the surface strain of the metal but also quantitatively measure it. The spatial distribution of the strain field can be mapped with high resolution by capturing the sensor image using a smartphone and analyzing its red, green, and blue components. This colorimetric method is applicable in both indoor and outdoor environments and can also be effective for detecting cracking or cleavage in rigid bodies.
High Efficiency Luminescent Solar Concentrator based on Organo‐Metal Halide Perovskite Quantum Dots with Plasmon Enhancement
Authors: Mendewala Benaz , Vickers Evan T. , Nikolaidou Katerina , DiBenedetto Albert , Delmas William G. , Zhang Jin Z. , Ghosh Sayantani
Published: July 2021

Organo‐metal halide perovskites (OMHPs) are currently one of the most exciting candidates for photovoltaics. However, their impact in other areas related to carrier photogeneration, such as in luminescent solar concentrators (LSCs), has been limited. OMHP thin films have demonstrated encouraging results as LSCs, but for a scalable platform with minimal losses, discrete emitters are preferable. Perovskite quantum dots (PQDs) possess higher photoluminescence quantum yield (PLQY) than their thin film counterparts, and have the added advantage of size tunability, which make them well‐suited as LSC active media. However, since PQDs are not amenable to Stokes shift modulation, large‐scale samples will suffer from increased self‐absorption (SA) losses. In this work, a facile dip‐coating approach is established to fabricating large‐scale LSCs with CH3NH3PbBr3 (methylammonium lead bromide) PQDs by leveraging their plasmonic interactions with gold nanoparticles (AuNPs) to offset SA losses. Optical characterization through emission, lifetime, and spatially resolved photoluminescence measurements provide insight into the effect of plasmon resonance on deposited PQDs, and leveraging this AuNP‐PQD coupling, 2.87% efficiency is achieved in a 100 cm2 LSC with a geometric gain of 50.