bluuebunny/crossref_metadata_2025 huggingface dataset:
Singlet oxygen is an early intermediate in cytokine‐dependent ultraviolet‐A induction of interstitial collagenase in human dermal fibroblasts in vitro
Authors: Wlaschek Meinhard , Wenk Jutta , Brenneisen Peter , Briviba Karlis , Schwarz Agatha , Sies Helmut , Scharffetter-Kochanek Karin
Published: July 2002

Ultraviolet (UV) A irradiation of human dermal fibroblasts elicits an increase in specific mRNA amounts and bioactivities of the cytokines IL‐1α, IL‐1β, and IL‐6. These effects are enhanced in deuterium oxide‐based medium and are diminished in the presence of non‐toxic concentrations of sodium azide. Furthermore, generating singlet oxygen outside the cells by irradiation of rose bengal‐coated resin particles with visible light (λ>450 nm) results in the induction of interstitial collagenase, IL‐1 and IL‐6, similar to the response observed with UVA irradiation. These observations suggest that singlet oxygen is an early intermediate in the signaling pathway of IL‐1 and IL‐6 mediating UVA induction of interstitial collagenase (E.C. 3.4.24.7). Furthermore, singlet oxygen appears to initiate this complex UV response at the cell membrane.
Adenovirus‐mediated transfer of the smooth muscle cell calponin gene inhibits proliferation of smooth muscle cells and fibroblasts
Authors: Jiang Zhong , Grange Robert W , Walsh Michael P , Kamm Kristine E
Published: July 2002

Smooth muscle cell calponin (h1 or basic isoform) is an actin‐binding protein that inhibits actomyosin MgATPase activity and is abundantly expressed in differentiated smooth muscle. Western blots showed bovine tracheal (BT) smooth muscle cells in culture expressed only 2±1% (n=8) of the amount of calponin in tissues, while NIH‐3T3 fibroblasts expressed none. We tested the hypothesis that introduction of calponin to cultured BT and 3T3 cells would inhibit cytoskeletal activities associated with cell proliferation. To achieve high‐efficiency expression, an adenovirus encoding the CMV–calponin construct (Adv‐CaP) was generated by homologous recombination in 293 cells. With greater than 90% of BT and 3T3 cells infected with Adv‐CaP, calponin expression (32 and 11 μg/mg total protein, respectively) was similar to that in smooth muscle tissues (51 μg/mg). Cells were infected with Adv‐CaP for 48 h, replated at low density and proliferation rates were assessed by cell density and [3H]thymidine incorporation. Cell growth and DNA synthesis by Adv‐CaP‐infected cells were inhibited to one‐third control values for both BT and 3T3 cells. Expressed calponin was localized primarily on stress fibers in both cell types. Calponin may act at the cytoskeletal level to retard signaling pathways that normally lead to tight coupling between cell shape and DNA synthesis.
Comparative mechanisms and rates of free radical scavenging by carotenoid antioxidants
Authors: Mortensen Alan , Skibsted Leif H. , Sampson Julia , Rice-Evans Catherine , Everett Steven A.
Published: July 2002

The comparative mechanisms and relative rates of nitrogen dioxide (NO2
⋅), thiyl (RS⋅) and sulphonyl (RSO2
⋅) radical scavenging by the carotenoid antioxidants lycopene, lutein, zeaxanthin, astaxanthin and canthaxanthin have been determined by pulse radiolysis. All the carotenoids under study react with the NO2
⋅ radical via electron transfer to generate the carotenoid radical cation (Car⋅+). In marked contrast the glutathione and 2‐mercaptoethanol thiyl radicals react via a radical addition process to generate carotenoid‐thiyl radical adducts [RS‐Car]⋅. The RSO2
⋅ radical undergoes both radical addition, [RSO2‐Car]⋅ and electron abstraction, Car⋅+. Both carotenoid adduct radicals and radical cations decay bimolecularly. Absolute rate constants for radical scavenging were in the order of ∼107–109 M−1 s−1 and follow the sequence HO(CH2)2S⋅>RSO2
⋅>GS⋅>NO2
⋅. Although there were some discernible trends in carotenoid reactivity for individual radicals, rate constants varied by no greater than a factor of 2.5. The mechanism and rate of scavenging is strongly dependent on the nature of the oxidising radical species but much less dependent on the carotenoid structure.
Protein kinase C (PKC) ϵ enhances the inhibitory effect of TNFα on insulin signaling in HEK293 cells
Authors: Kellerer Monika , Mushack Joanne , Mischak Harald , Häring Hans Ulrich
Published: July 2002

Recently we have shown that PKC β1 and β2 are able to inhibit the tyrosine kinase activity of the human insulin receptor (HIR). Now we have investigated whether a distinct PKC isoform might be involved in the inhibitory effect of TNFα on insulin signaling in HEK293 cells. TNFα induces a rapid translocation of the PKC isoform ϵ (TNFα 10−9 M, maximal effect within 5–10 min) in rat‐1 fibroblasts, while no effect occurred on other isoforms. Cotransfection of HIR with PKC ϵ did not significantly reduce the insulin stimulated receptor kinase activity; however, when cells were incubated with TNFα for 10 min (10−9 M) a 62±17% (n=5) inhibition of the insulin receptor kinase activity was observed which was significantly (P<0.01) higher than that observed in cells which were not transfected with PKC (32±11.5%, n=5). The data suggest that translocation of PKC ϵ induced by TNFα enables this PKC isoform to interact with insulin signaling and to inhibit the insulin receptor kinase activity.
Ceramide‐activated protein phosphatase‐2A activity in insulin‐secreting cells
Authors: Kowluru Anjaneyulu , Metz Stewart A
Published: July 2002

Okadaic acid (OKA)‐sensitive phosphatase (PP2A) activity may modulate nutrient‐induced insulin secretion from pancreatic β cells [Kowluru et al., Endocrinology 137 (1996) 2315–2323]. Ceramides, a new class of lipid second messengers may regulate PP2A [Dobrowsky and Hannun, J. Biol. Chem. (1992) 267, 5048–5051], and might play a role in cytokine‐mediated apoptosis in β cells [Sjöholm, FEBS Lett. 367 (1995) 283–286]. Therefore, we investigated the regulation of PP2A‐like activity by ceramides in isolated β (HIT‐T15 or INS‐1) cells. Cell‐permeable (C2, C6 or C18) ceramides stimulated OKA‐sensitive (but not ‐insensitive) phosphatase activity in a concentration‐dependent manner (0–12.5 μM), with maximal stimulation (+50–100%) at <12.5 μM. C2‐dihydroceramide (a biologically inactive analog of C2 ceramide) failed to augment PP2A‐like activity. Stimulatory effects of ceramides do not appear to be mediated via activation of the carboxyl methylation of the catalytic subunit of protein phosphatase 2A, since no effects of ceramides (up to 25 μM) were demonstrable on this parameter. These data identify a ceramide‐activated protein phosphatase as a possible locus at which ceramides might exert their effects on β cells leading to altered insulin secretion, and decreased cell viability followed by apoptotic cell demise.
Vascular endothelial growth factor stimulates prostacyclin production and activation of cytosolic phospholipase A2 in endothelial cells via p42/p44 mitogen‐activated protein kinase
Authors: Wheeler-Jones Caroline , Abu-Ghazaleh Robin , Cospedal Rosario , Houliston Rebecca A , Martin John , Zachary Ian
Published: July 2002

Vascular endothelial growth factor (VEGF) stimulated a time‐ and concentration‐dependent increase in PGI2 synthesis in human umbilical vein endothelial cells with a mean maximum increase of 2‐fold above basal levels at 25 ng/ml after 60 min. VEGF also rapidly stimulated the release of arachidonic acid and phosphorylation and activation of cytosolic phospholipase A2 (cPLA2). The VEGF‐related factor, placenta growth factor (PlGF), had little effect on PGI2 synthesis, arachidonic acid release or cPLA2 activation. PD98059, a selective inhibitor of MAP kinase kinase, caused complete inhibition of VEGF‐stimulated MAP kinase activity, PGI2 synthesis and cPLA2 gel retardation, but had no effect on VEGF‐induced vWF secretion. These findings provide the first evidence that VEGF can stimulate PGI2 synthesis via cPLA2‐mediated arachidonic acid release and indicate that VEGF stimulation of this biosynthetic pathway may occur, at least in part, via activation of p42/p44 MAP kinases.
The N‐terminal globular domain of the laminin α1 chain binds to α1β1 and α2β1 integrins and to the heparan sulfate‐containing domains of perlecan
Authors: Ettner Norbert , Göhring Walter , Sasaki Takako , Mann Karlheinz , Timpl Rupert
Published: July 2002

The N‐terminal domains VI plus V (62 kDa) and V alone (43 kDa) of the laminin α1 chain were obtained as recombinant products and shown to be folded into a native form by electron microscopy and immunological assays. Domain VI alone, which corresponds to an LN module, did not represent an autonomously folding unit in mammalian cells, however. Fragment α1VI/V, but not fragment α1V, bound to purified α1β1 and α2β1 integrins, to heparin, and to heparan sulfate‐substituted domains I and V of perlecan. This localized the binding activities to the LN module, which contains two basic sequences suitable for heparin interactions.
Functional characterization of mongoose nicotinic acetylcholine receptor α‐subunit: resistance to α‐bungarotoxin and high sensitivity to acetylcholine
Authors: Asher Orna , Lupu-Meiri Monica , Jensen Bo S , Paperna Tamar , Fuchs Sara , Oron Yoram
Published: July 2002

The mongoose is resistant to snake neurotoxins. The mongoose muscle nicotinic acetylcholine receptor (AChR) α‐subunit contains a number of mutations in the ligand‐binding domain and exhibits poor binding of α‐bungarotoxin (α‐BTX). We characterized the functional properties of a hybrid (α‐mongoose/βγδ‐rat) AChR. Hybrid AChRs, expressed in Xenopus oocytes, respond to acetylcholine with depolarizing current, the mean maximal amplitude of which was greater than that mediated by the rat AChR. The IC50 of α‐BTX to the hybrid AChR was 200‐fold greater than that of the rat, suggesting much lower affinity for the toxin. Hybrid AChRs exhibited an apparent higher rate of desensitization and higher affinity for ACh (EC50 1.3 vs. 23.3 μM for the rat AChR). Hence, changes in the ligand‐binding domain of AChR not only affect the binding properties of the receptor, but also result in marked changes in the characteristics of the current.
The intramitochondrial ATP/ADP‐ratio controls cytochrome c oxidase activity allosterically1
Authors: Arnold Susanne , Kadenbach Bernhard
Published: July 2002

Recently the signal transduction function for oxidative phosphorylation was found to be second order in ADP [Jeneson, J.A.L., Wiseman, R.W., Westerhoff, H.V. and Kushmerick, M.J. (1996) J. Biol. Chem. 271, 27995–27998], but the molecular mechanism of signal transduction remained unclear. Previously we described inhibition of cytochrome c oxidase by intramitochondrial ATP, accompanied by a change of hyperbolic into sigmoidal kinetics. The present study describes a sigmoidal relationship also between the ascorbate respiration of reconstituted cytochrome c oxidase and intraliposomal ADP concentration. Its possible role in the control of oxidative phosphorylation and cell respiration is discussed.
Kinetic and spectroscopic characterization of an intermediate peroxynitrite complex in the nitrogen monoxide induced oxidation of oxyhemoglobin1
Authors: Herold Susanna
Published: July 2002

Stopped‐flow spectroscopy studies of the nitrogen monoxide mediated oxidation of oxyhemoglobin in the pH range 5–10.5 show that an intermediate can be characterized at alkaline pH. The rate of decay of this species to methemoglobin increases significantly with decreasing pH such that it does not accumulate in quantities large enough to be observed under neutral or acidic conditions. Kinetic and spectroscopic properties of this intermediate support its assignment as a methemoglobin peroxynitrite complex.
Expression of uncoupling protein‐3 and mitochondrial activity in the transition from hypothyroid to hyperthyroid state in rat skeletal muscle
Authors: Lanni A , Beneduce L , Lombardi A , Moreno M , Boss O , Muzzin P , Giacobino J.P , Goglia F
Published: July 2002

We sought a correlation between rat skeletal muscle triiodothyronine (T3)‐mediated regulation of uncoupling protein‐3 (UCP3) expression and mitochondrial activity. UCP3 mRNA expression increased strongly during the hypothyroid‐hyperthyroid transition. The rank order of mitochondrial State 3 and State 4 respiration rates was hypothyroid<euthyroid<hyperthyroid. The State 4 increase may have been due to the increased UCP3 expression, as the proton leak kinetic was stimulated in the hypothyroid‐hyperthyroid transition and a good correlation exists between the State 4 and UCP3 mRNA level. As a significant proportion of an organism's resting oxygen consumption is dedicated to opposing the proton leak, skeletal muscle mitochondrial UCP3 may mediate part of T3's effect on energy metabolism.
PPARγ activators down‐regulate the expression of PPARγ in 3T3‐L1 adipocytes
Authors: Camp Heidi S , Whitton Amy L , Tafuri Sherrie R
Published: July 2002

Transcriptional activation of PPARγ by the anti‐diabetic compound troglitazone enhances the rate of 3T3‐L1 adipocyte differentiation. In this study, we examined the effects of troglitazone, a specific PPARγ ligand, on the expression of PPARγ during and after 3T3‐L1 adipocyte differentiation. Troglitazone treatment caused a significant decrease in PPARγ proteins and DNA binding activity. This reduction was associated with a similar decrease in transcription of PPARγ mRNA. These data suggest that in 3T3‐L1 cells, the expression of PPARγ is auto‐regulated.
Serum‐stimulated cell cycle entry of fibroblasts requires undisturbed phosphorylation and non‐phosphorylation interactions of the catalytic subunits of protein kinase CK2
Authors: Lorenz Peter , Ackermann Karin , Simoes-Wuest Paula , Pyerin Walter
Published: July 2002

Protein kinase CK2 is a pleiotropic Ser/Thr kinase occurring as α2β2, α′2β2, or αα′β2 tetramers. A requirement in serum‐stimulated cell cycle entry in both the cytoplasm and the nucleus of human fibroblasts for phosphorylation(s) by CK2 has been concluded from stimulation inhibition by microinjected antibodies against the regulatory subunit (β). We have now examined this idea more directly by microinjection‐mediated perturbation of phosphorylation and non‐phosphorylation interactions of the catalytic subunits (α and α′), and by verifying the supposed matching of the cellular partition of CK2 subunits in the fibroblasts employed. While immunostaining and cell fractionation indicate that the partitions of subunits indeed match each other (with their predominant location in the nucleus in both quiescent and serum‐stimulated cells), microinjection of substrate or pseudosubstrate peptides competing for the CK2‐mediated phosphorylation in vitro resulted in significant inhibition of serum stimulation when placed into the nucleus but not when placed into the cytoplasm. Also inhibitory were nuclear but not cytoplasmic injections of antibodies against α and α′ that affect neither their kinase activity in vitro nor their complexing to β. The data indicate that the role played by CK2 in serum‐stimulated cell cycle entry is predominantly nuclear and more complex than previously assumed, involving not only phosphorylation but also experimentally separable non‐phosphorylation interactions by the catalytic subunits.
A novel anti‐hypertensive peptide derived from ovalbumin induces nitric oxide‐mediated vasorelaxation in an isolated SHR mesenteric artery
Authors: Matoba Nobuyuki , Usui Hachiro , Fujita Hiroyuki , Yoshikawa Masaaki
Published: July 2002

In this report, we deal with the isolation of a novel vasorelaxing peptide from a chymotryptic digest of ovalbumin and its vasorelaxing activities. This peptide is composed of Arg‐Ala‐Asp‐His‐Pro‐Phe (RADHPF) in its sequence, corresponding to residues 359–364 of ovalbumin. This peptide (30–300 μM) exerted a dose‐dependent vasodilation in an isolated mesenteric artery from a spontaneously hypertensive rat which was pre‐constricted by phenylephrine, besides the relaxation being endothelium‐dependent. It is noteworthy that the nitric oxide synthase inhibitor N
G‐nitro‐L‐arginine methyl ester inhibited this relaxation, implying involvement of nitric oxide in its mechanism of action. Following oral administration of RADHPF at a dose of 10 mg/kg, the systolic blood pressure in a spontaneously hypertensive rat was significantly lowered.
Caspases‐3 and ‐7 are activated in goniothalamin‐induced apoptosis in human Jurkat T‐cells
Authors: Inayat-Hussain Salmaan H. , Osman Annuar B. , Din Laily B. , Ali Abdul M. , Snowden Roger T. , MacFarlane Marion , Cain Kelvin
Published: July 2002

Goniothalamin, a plant styrylpyrone derivative isolated from Goniothalamus andersonii, induced apoptosis in Jurkat T‐cells as assessed by the externalisation of phosphatidylserine. Immunoblotting showed processing of caspases‐3 and ‐7 with the appearance of their catalytically active large subunits of 17 and 19 kDa, respectively. Activation of these caspases was further evidenced by detection of poly(ADP‐ribose) polymerase cleavage (PARP). Pre‐treatment with the caspase inhibitor benzyloxycarbonyl‐Val‐Ala‐Asp fluoromethyl ketone (Z‐VAD.FMK) blocked apoptosis and the resultant cleavage of these caspases and PARP. Our results demonstrate that activation of at least two effector caspases is a key feature of goniothalamin‐induced apoptosis in Jurkat T‐cells.
An antigenic HIV‐1 peptide sequence engineered into the surface structure of transferrin does not elicit an antibody response
Authors: Ali Stuart A , Joao Heidi C , Hammerschmid Franz , Eder Jörg , Steinkasserer Alexander
Published: July 2002

One novel approach for the biological delivery of peptide drugs is to incorporate the sequence of the peptide into the structure of a natural transport protein such as human serum transferrin (HST). However, a potential drawback is that the HST may increase the immunoreactivity of the peptide, in the same way that carrier proteins can be used to generate highly immunogenic peptide hapten conjugates. In this study we have generated a recombinant HST carrier protein that contains a peptide substrate of HIV‐1 protease (VSQNYPIVL). The protein retained native HST function, and the peptide was surface exposed since it was immunoreactive in native dot blots, and was cleaved by HIV‐1 protease. Immunisation of rabbits with the recombinant protein elicited only a very poor anti‐peptide immune response. In contrast, strong anti‐peptide immune responses were raised against both the peptide alone, and a chemical conjugate of the peptide with HST. These data demonstrate that it is possible to attenuate the immune response normally directed against an immunogenic peptide sequence by engineering into a surface exposed loop of HST. These findings may have an important impact on the future design of peptide delivery systems.
Unique sequence of a high molecular weight myosin light chain kinase is involved in interaction with actin cytoskeleton
Authors: Kudryashov Dmitry S. , Chibalina Margarita V. , Birukov Konstantin G. , Lukas Thomas J. , Sellers James R. , Van Eldik Linda J. , Watterson D.Martin , Shirinsky Vladimir P.
Published: July 2002

Myosin light chain kinase (MLCK) is the key regulator of cell motility and smooth muscle contraction in higher vertebrates. We searched for the features of the high molecular weight MLCK (MLCK‐210) associated with its unique N‐terminal sequence not found in a more ubiquitous lower molecular weight MLCK (MLCK‐108). MLCK‐210 demonstrates stronger association with the Triton‐insoluble cytoskeletons than MLCK‐108, suggesting the role for this sequence in subcellular targeting. Indeed, the expressed unique domain of MLCK‐210 binds and bundles F‐actin in vitro and colocalises with the microfilaments in transfected cells reproducing endogenous MLCK‐210 distribution. Thus, MLCK‐210 features an extensive actin binding interface and, perhaps, acts as an actin cytoskeleton stabiliser.
Adrenomedullin suppresses interleukin‐1β‐induced tumor necrosis factor‐α production in Swiss 3T3 cells
Authors: Isumi Yoshitaka , Kubo Atsushi , Katafuchi Takeshi , Kangawa Kenji , Minamino Naoto
Published: July 2002

We demonstrated that adrenomedullin (AM) inhibited interleukin‐1β‐induced tumor necrosis factor‐α (TNF‐α) secretion and gene transcription in Swiss 3T3 fibroblasts maximally to 23% and 18% of control, while the other peptides elevating intracellular cAMP levels elicited much weaker effects. AM rapidly reduced the gene transcript level of TNF‐α, inducing a maximal effect within 1 h. The inhibitory effect of AM was restored with an AM receptor antagonist as well as a cAMP‐dependent protein kinase inhibitor. These findings indicate that AM is a potent and quick suppressor of TNF‐α production in Swiss 3T3 cells acting through the cAMP protein kinase A pathway. As TNF‐α is a major inflammatory cytokine and stimulates AM production in fibroblasts, AM is deduced to be an autocrine or paracrine factor suppressing inflammation through the inhibition of TNF‐α production.
Pelvic examination, transvaginal ultrasound and transvaginal color Doppler sonography as predictors of ovarian cancer
Authors: Buckshee K. , Temsu I. , Bhatla N. , Deka D.
Published: July 2002

Objective: To assess and compare the efficacy of pelvic examination, transvaginal ultrasound and transvaginal color Doppler imaging in differentiating benign and malignant ovarian tumors. Methods: 34 patients with ovarian tumors scheduled for laparotomy underwent pelvic examination and a diagnosis of benign or malignant tumor was made. Transvaginal ultrasound was carried out to study the ovarian morphology followed by color Doppler imaging. A score of ≥9 on Sassone scoring system or a pulsatility index <1 was taken as suspicious for malignancy. Results: Of all the three indicators (pelvic examination, transvaginal sonography and Doppler) transvaginal sonography had the highest sensitivity (100%) and Doppler had maximum specificity (96.29%) for predicting malignancy. However, statistical analysis did not show any difference in the predicting ability of these three modalities. Conclusion: Pelvic examination, transvaginal sonography and Doppler all had similar ability to predict malignancy in an adnexal mass.
Microspectrofluorometry of autofluorescence emission from human leukemic living cells under oxidative stress
Authors: Bondza‐Kibangou Patrick , Millot Christine , Dufer Jean , Millot Jean‐Marc
Published: July 2002

Summry— Image cytometry was applied to study the intracellular localization of autofluorescence and the influence of an oxidative stress on this emission. K562 erythroleukemia cancer cells were analyzed with a microspectrofluorometer, coupled with a Argon laser (Ar+) (363 nm). From each cell, 15 × 15 emission spectra were recorded in the 400‐600 nm spectral range to generate a spectral image of autofluorescence. The intracellular locations of the autofluorescence emission and of the specific mitochondrial probe rhodamine 123 (R123) were matched. Under a 363 nm excitation, all spectra from K562 cells show equivalent profiles with a 455 nm maximum emission, near of reduced nicotinamide adenine dinucleotide‐(Phosphate) solution (NAD(P)H) (465 nm maximum emission). The spatial distribution of autofluorescence is homogeneous and different from the one of R123. Hydrogen peroxide (H2O2) (200 μM) and menadione (Men) (5 μM) induce a weak spectral change and a decrease in autofluorescence intensity, down to 40% of the initial emission. Doxorubicin (Dox) induces a dose‐dependent decrease in autofluorescence emission and a release of intracellular free radicals. When cells were pre‐treated 1 h with 1 mM glutathione (GSH), Dox induces a lower free radicals release, no significant variation of autofluorescence intensity and a lower growth inhibitory effect. Images cytometry of autofluorescence suggest that the intracellular NAD(P)H would not be restricted to mitochondrial compartments. The release of free radicals was associated with a decrease in autofluorescence intensity, mainly attributed to NAD(P)H oxidation both inside and outside mitochondria.
Physiological activity‐dependent ultrastructural plasticity in normal adult rat neuromuscular junctions
Authors: Tomas Josep , Santafé Manel , Lanuza Maria A , Fenoll‐Brunet Maria R
Published: July 2002

The major finding of the present study is that the ultrastructural organization of the neuromuscular synapse can be modified by a small, 4‐week‐long, physiological increase in the locomotor activity of the extensor digitorum longus muscle of normal adult rats trained to walk. This study measures these plastic adaptations using several synaptic morphological parameters. The observed changes in neuromuscular junctions affect both pre‐ and postsynaptic membranes. In particular, the presynaptic membrane densities in the active zones and the postsynaptic adaxonal membrane densities become larger, which shows that in the normal adult mammal neuromuscular junction, there is an activity‐dependent modulation of the neurotransmission‐related structures in response to slight physiologic functional demands. The nature and magnitude of these changes are discussed.
Human issues in service design
Authors: Cook Lori S. , Bowen David E. , Chase Richard B. , Dasu Sriram , Stewart Doug M. , Tansik David A.
Published: July 2002

A heightened awareness of the fundamental behavioral science principles underlying human interactions can be translated directly into service design. Service encounter design can be approached with the same depth and rigor found in goods production. Service encounters can be designed to enhance the customer’s experience during the process and their recollection of the process after it is completed. This paper summarizes the key concepts from a panel discussion at the DSI National Meeting in Orlando in November 2000. The panel brought together a number of leading academic researchers to investigate current research questions relating to the human side of the design, development and deployment of new service technologies. Human issues from the customer and service provider vantage are illustrated and challenges to researchers for exploring this perspective are presented.
An international comparison of environmental management in operations: the impact of manufacturing flexibility in the U.S. and Germany
Authors: Klassen Robert D , Angell Linda C
Published: July 2002

Pressures to improve environmental management in the U.S. and Germany are among the strongest in the world, demanding quick responsiveness from managers of manufacturing firms. However, even in these countries, the managerial implications of environmental regulation can vary dramatically. Our synthesis of related literatures indicates that manufacturing flexibility, by enabling efficient adaptation to change and uncertainty, can support environmental management. This paper empirically explores the linkage between flexibility and environmental management in the U.S. and Germany. Environmental management was operationalized along two dimensions: level of environmental ambition, defined as scope of environmental efforts; and level of regulatory‐driven motivation. Survey data were collected from a sample of 218 U.S. and German manufacturing sites. Neither the probability of having a dedicated environmental department nor of having an environmental policy statement differed between countries; however, the impact of flexibility on the level of ambition was found to vary significantly between countries. One potential explanation is that command‐and‐control regulation of the manufacturing process is heavily emphasized in the U.S., while closed loop (recycling) regulation of final product disposition is predominant in Germany. Thus, manufacturing firms need to evaluate general regulatory differences between countries before using manufacturing flexibility to support environmental management. Future research needs to explore whether other operational capabilities, such as quality, also support environmental management across international contexts.
The relationship of strategy, fit, productivity, and business performance in a services setting
Authors: Smith Thomas M , Reece James S
Published: July 2002

In their review of the operations strategy literature, Anderson et al. [Anderson, J.C., Cleveland, G., Schroeder, R.G., 1989. Operations strategy: a literature review. J. Operations Manage., 8(2): 133‐158] contend that the hypothesis that a company will perform better if it links its operations strategy to the business strategy is intuitively appealing, but lacks empirical verification. In light of this contention, this research attempts to: (1) define and measure the concept of fit as it applies to operations strategy; (2) show how fit leads to better performance; and (3) investigate the interrelationships between fit, business strategy, productivity, and performance. These objectives are investigated through field‐based research within a wholesale distribution service setting. Utilizing the classificatory framework of Venkatraman [Venkatraman, N., 1989. The concept of fit in strategy research: toward verbal and statistical correspondence. Acad. Manage. Rev., 14(3): 423‐444], fit is defined as the degree to which operational elements match the business strategy. This precise definition closely resembles the concept of ‘external fit’ that began with the work of Skinner [Skinner, W., 1969. Manufacturing–missing link in corporate strategy. Harvard Bus. Rev., 47(3): 136‐145]. A conceptual model of business performance is used with productivity as a mediating variable between the independent variables of business strategy and external fit and the dependent variable of business performance. Path analysis is used to analyze the effect of external fit on performance and to investigate the interrelationships between fit, business strategy, productivity, and performance. The results show that external fit has a significant positive and direct effect on business performance. When coupled with the nonsignificant direct effects of the strategy variables, this suggests that the fit of the operational elements with the strategy is of greater importance than the particular choice of strategy. Although all three business strategies (low cost, a combination of low cost and high customer service, and high customer service) had no significant direct effects on performance, a high customer service strategy did have a significant positive effect on the intervening productivity variable. Finally, the particular design of the research and the findings suggest that much of the conceptual work in operations strategy may be applicable to service operations as well as manufacturing.
Collagen gene expression and mechanical properties of intervertebral disc cell–alginate cultures
Authors: Baer Anthony E. , Wang Jean Y. , Kraus Virginia B. , Setton Lori A.
Published: July 2002

Cells of the intervertebral disc have a limited capacity for matrix repair that may contribute to the onset and progression of degenerative disc changes. In this study, the biosynthetic capacity of cells isolated from specific regions of the porcine intervertebral disc was evaluated in vitro. Using a competitive reverse transcription‐polymerase chain reaction technique, gene expression levels for types I and II collagen were quantified in cells cultured for up to 21 d in a three‐dimensional alginate culture system and compared to levels obtained for cells in vivo. The mechanical properties of cell‐alginate constructs were measured in compression and shear after periods of culture up to 16 weeks. Cells from the anulus fibrosus expressed the most type I collagen mRNA in vivo and in vitro, while cells from the transition zone expressed the most type II collagen mRNA in vivo and in vitro. Mechanical testing results indicate that a mechanically functional matrix did not form at any time during the culture period; rather, decreases of up to 50% were observed in the compressive and shear moduli of the cell–alginate constructs compared to alginate with no cells. Together with results of prior studies, these results suggest that intervertebral disc cells maintain characteristics of their phenotype when cultured in alginate, but the molecules they synthesize are not able to form a mechanically functional matrix in vitro. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Phospholipid composition of articular cartilage boundary lubricant
Authors: Sarma A. V. , Powell G. L. , LaBerge M.
Published: July 2002

The mechanism of lubrication in normal human joints depends on loading and velocity conditions. Boundary lubrication, a mechanism in which layers of molecules separate opposing surfaces, occurs under severe loading. This study was aimed at characterizing the phospholipid composition of the adsorbed molecular layer on the surface of normal cartilage that performs as a boundary lubricant. The different types of phospholipid adsorbed onto the surface of cartilage were isolated by extraction and identified by chromatography on silica gel paper and mass spectroscopy. The main phospholipid classes identified were quantified by a phosphate assay. Gas chromatography and electrospray ionization mass spectrometry were used to further characterize the fatty acyl chains in each major phospholipid component and to identify the molecular species present. Phosphatidylcholine (41%), phosphatidylethanolamine (27%) and sphingomyelin (32%) were the major components of the lipid layer on the normal cartilage surface. For each lipid type, a mixture of fatty acids was detected, with a higher percentage of unsaturated species compared to saturated species. The most abundant fatty acid observed with all three lipid types was oleic acid (C18:1). Additional work to further quantify the molecular species using electrospray ionization mass spectrometry is recommended. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Oxidative stress, brain white matter damage andintrauterine asphyxia in fetal lambs
Authors: Ikeda Tomoaki , Choi Ben H. , Yee Simon , Murata Yuji , Quilligan Edward J.
Published: July 2002

In order to examine the role of oxidative stress in asphyxia‐induced perinatal braindamage, near‐term fetal lambs were subjected to umbilical cord occlusion for approximately 60 min until fetal arterial pH diminished to less than 6.9 and base excess to less than −20 meq/l. Thelevels of superoxide, hydrogen peroxide, glutathione (GSH) and thiobarbiturate‐reactivesubstances (TBARS) within brain grey and white matter were determined at 72 h to correlatewith morphological changes. Although the topography and extent of brain damage variedsomewhat from case to case, ranging from focal infarction in grey or white matter to subtle andpatchy alterations of white matter, the telencephalic white matter appeared to bear the brunt ofdamage as compared to other regions. The parietal white matter, in particular was often the seatof early pathological changes that could be seen in isolation. These white matter changes wereaccompanied by significant increases in hydrogen peroxide and TBARS levels as compared tothose in grey matter. In another set of experiments, 8 different brain regions were assayed forTBARS, GSH and superoxide dismutase (SOD). A highly significant rise in the levels of TBARSwas again noted in the parietal and frontal white matter. SOD levels were higher in the frontal andparietal white matter, basal ganglia and cerebellum. Cerebral cortical and hippocampal neuronswere relatively unaffected until accompanied by more severe damage to grey and white matter atother sites. These results suggest that the developing telencephalic white matter appears to bemost vulnerable to the effects of intrauterine fetal asphyxia and that oxidative stress may be amajor contributing factor in the pathogenesis of perinatal hypoxic–ischemic encephalopathy.
Polydipsia and water intoxication in 353 psychiatric inpatients: an epidemiological and psychopathological study
Authors: Mercier-Guidez E. , Loas G.
Published: July 2002

Introduction

According to several authors, water intoxication can lead to irreversible brain damage and could be the cause of nearly a fifth of the deaths of schizophrenic patients below the age of 53 years. The aim of our study was first to determine the prevalence of polydipsia and water intoxication in a population of psychiatric inpatients of a well-defined French geographic area (the Somme), and secondly to determine the clinical and socio-demographic factors associated with this disorder.

Methods

A cross-sectional survey was done on the 450 psychiatric beds whose catchment area had a total population of 559,429 inhabitants. Using staff reports and patients’ charts, the drinking habits of 353 psychiatric inpatients hospitalised during the survey in the 450 psychiatric beds of this area were examined.

Results

Thirty-eight patients (10.76%; 95% confidence interval: 7.53–13.99%) among the 353 inpatients were polydipsic. About one-third of these patients were at risk of water intoxication. Polydipsia appeared to be significantly associated with male gender, smoking, celibacy and chronicity. The polydipsic patients presented also a high prevalence of schizophrenia, mental retardation, pervasive developmental disorders and high frequency of somatic disorders.
Amisulpride has a superior benefit/risk profile to haloperidol in schizophrenia: results of a multicentre, double-blind study (the Amisulpride Study Group*
Authors: Carrière P. , Bonhomme D. , Lempérière T.
Published: July 2002

In a multicentre, double-blind, flexible-dose study, 199 patients with paranoid schizophrenia or schizophreniform disorders received haloperidol (10–30 mg/d) or amisulpride (400–1200 mg/d) for four months. More patients in the haloperidol group withdrew prematurely (44% vs 26%;P = 0.0077) due to a higher incidence of adverse events. Amisulpride was at least as effective as haloperidol in reducing the Brief Psychiatric Rating Scale (BPRS) total score (–27.3 vs –21.9) (non-inferiority test;P < 0.001). The PANSS positive score improved to a similar extent in both groups whilst improvement in the PANSS negative score was significantly greater with amisulpride (–10.5 vs –7.2;P = 0.01). The percentage of responders on the Clinical Global Impression scale was also significantly greater with amisulpride (71% vs 47%;P < 0.001). Both the Quality of Life Scale (QLS) and the Functional Status Questionnaire (FSQ) improved to a significantly greater extent under amisulpride. Haloperidol was associated with a greater incidence in extrapyramidal symptoms and with a greater increase in the Simpson-Angus score than was seen with amisulpride (0.32 vs 0.02;P < 0.001). In conclusion, amisulpride is globally superior to haloperidol in the treatment of acute exacerbations of schizophrenia and significantly improves patients’ quality of life and social adjustment.
On the conceptualisation of subaffective personality disorders
Authors: Herpertz S , Steinmeyer EM , Saß H
Published: July 2002

The reconceptualisation of German traditional constructs of subaffective personality disorders (PDs) was stimulated by clinical and some empirical evidence of mild and enduring alterations of mood and drive in patients who never developed one of the full-blown mood disorders. The aim of the study was to clarify the status of historical concepts of subaffective PDs (as there are the depressive, hyperthymic, cyclothymic, and asthenic type) in relation to the modern Diagnostic and Statistical Manual (DSM)-III-R conceptions of personality disorders and the five factor theory of personality. A consecutive psychiatric sample and a normal control sample were used to investigate these relationships. By means of a non-metric multi-dimensional scaling procedure, and facet theoretical interpretation, the depressive and asthenic PDs were demonstrated to correspond highly with the global construct of PD as well as with the personality factor neuroticism which proved to be elevated in most types of PDs within the clinical sample. The hyperthymic and cyclothymic categories displayed differences to most DSM-III-R constructs of PD in the clinical but not in the control sample. The findings may explain the chronic course of some depressive or somatization disorders that are difficult to influence by pharmacotherapy and that may require special treatment strategies.
Alterations in myocardial creatinine kinase (CK) and lactate dehydrogenase (LDH) isoenzyme‐distribution in a model of left ventricular dysfunction
Authors: Muders Frank , Neubauer Stefan , Luchner Andreas , Fredersdorf Sabine , Ickenstein Guntram , Riegger Günter A.J. , Horn Michael , Elsner Dietmar
Published: July 2002

The purpose of the current study was to evaluate myocardial creatinine kinase (CK) and lactate dehydrogenase (LDH) systems in a model of epinephrine‐induced cardiomyopathy in rabbits. Eight rabbits received four repetitive epinephrine infusions (300 mg/kg/60 min, i.v.) in 12‐day intervals and eight untreated rabbits served as controls (CTRL). Echocardiography demonstrated a significant deterioration of LV function as well as increased LV‐diameter and ‐mass index in catecholamine‐induced cardiomyopathy. Histological examination revealed that repetitive catecholamine infusion resulted in LV fibrous areas with collagenous content and an increase in myocyte width (16.9 ± 0.8 μm vs. CTRL 12.9 ± 0.9; P < 0.05). LV dysfunction was associated with a decreased total LV lactate dehydrogenase activity (LDH; 0.43 ± 0.03 IU/mg protein vs. CTRL 0.52 ± 0.04; P < 0.05) whereas total creatinine kinase activity was unchanged (CK; 7.30 ± 0.63 IU/mg protein vs. CTRL 9.20 ± 0.49, n.s.). Furthermore, myocardial LDH isoenzymes were shifted with a decrease in LDH1 and an increase in LDH2 and LDH3 (LDH1: 84.90 ± 2.60% vs. CTRL 94.50 ± 0.40; LDH2: 7.30 ± 1.20% vs. 1.50 ± 0.13; LDH3: 5.40 ± 0.90% vs. 3.20 ± 0.25; all P < 0.05). Foetal B‐CK isoenzymes were significantly increased (CK‐MB 5.30 ± 0.66 vs. 2.20 ± 0.35%; P < 0.05). The current study demonstrates changes in cardiac energy metabolism including an impaired LDH activity with a shift towards anaerobic isoenzymes as well as a more efficient CK system in a model of catecholamine‐induced LV dysfunction.
Aspirin does not influence the effect of angiotensin‐converting enzyme inhibition on left ventricular ejection fraction 3 months after acute myocardial infarction
Authors: Hurlen Mette , Hole Torstein , Seljeflot Ingebjørg , Arnesen Harald
Published: July 2002

The aim of the present study was to evaluate the possible interaction between chronic aspirin therapy and angiotensin‐converting enzyme inhibitor (ACE‐I) on left ventricular ejection fraction (LVEF) in patients surviving an acute myocardial infarction (AMI). Forty‐two patients with reduced LVEF were recruited from the warfarin aspirin reinfarction study (WARIS‐II), a randomized, open study comparing enteric coated aspirin (160 mg/d), warfarin (INR 2.8–4.2) and the combination of aspirin (75 mg/d) and warfarin (INR 2.0–2.5) on mortality, reinfarction and stroke after AMI. LVEF and relevant biochemical measurements were performed before discharge and after 3 months. The overall LVEF increased during the study period from median 35 to 39% (P < 0.001). There was no difference between patients on aspirin and warfarin regarding the main end point, LVEF. Furthermore, neither endothelin‐1 nor ANP showed significant differences between the treatment groups. A possible interaction between ACE‐I and aspirin might theoretically lead to reduced levels of renin activity in patients on aspirin, but we did not find any such inter‐group difference. In conclusion, we did not find evidence of interaction between ACE‐I and low‐dose aspirin.
Malnutrition in patients suffering from chronic heart failure; the nurse's care
Authors: Anna Jacobsson , Pihl‐Lindgren Emma , Bengt Fridlund
Published: July 2002

Chronic heart failure is associated with a bad prognosis with considerably shortened survival and repeated hospitalisations. Patients suffering from heart failure also have symptoms that can affect their food intake, for example, tiredness when strained, breathing difficulties and gastrointestinal symptoms like nausea, loss of appetite and ascites. Pharmacological therapy can lead to a loss of appetite, which will make the intake of food inadequate to fill the required energy and nutritional needs. The nurse's interest in and knowledge of diet issues can improve these patients' nutritional status. The aim of this literature review was to describe the nurse's interventions regarding malnutrition in patients suffering from chronic heart failure. The literature search gave 13 articles, which were analysed, and sentences whose content was related to the aim were identified. Three areas of content appeared; drug treatment and consequences, gastrointestinal effects, and information and education. The results show that the nutritional status of these patients can be significantly improved by means of simple nursing interventions. Future research should focus on controlled experimental studies to evaluate differences in body weight, body mass index and quality of life between patients suffering from chronic heart failure, who are taking part in a fully enriched nutrition intervention, and patients suffering from chronic heart failure, who are eating their normal diet.
Endoscopic Visualization of Contact Line Dynamics during Pool Boiling on Capillary‐Activated Copper Microchannels
Authors: Li Jiaqi , Zhu Gaohua , Kang Daniel , Fu Wuchen , Zhao Yongyi , Miljkovic Nenad
Published: November 2020

Microchannel surfaces are common to microfluidics, biofluidics, thermal management, and energy applications. Due to processing limitations for the majority of metallic materials, the majority of hyperfine microchannels used in microfluidics and thermo‐fluids are fabricated on non‐metallic substrates, for example, silicon and polydimethylsiloxane. Here, a technique to fabricate ultrasmall microchannels on arbitrary metallic materials is developed using photolithography in combination with electrochemical deposition. The technique is used to prepare copper microchannels and to investigate the pool boiling heat transfer performance with a focus on the three‐phase contact line dynamics. The hydrodynamics of nucleating bubbles during boiling are observed in situ using in‐liquid endoscopy. The results show that the variation of critical heat flux enhancement has a linear relationship with the contact line increase ratio. The scalable microchannel surfaces exhibit superior heat transfer performance with a maximum heat transfer coefficient) enhancement of 930% with ultra‐low wall superheat of 5 °C. This work not only develops a scalable manufacturing method to develop ultra‐small microchannels on metallic materials, it outlines design guidelines for structure optimization of pool boiling heat transfer for temperature sensitive applications, such as electronics thermal management.