bluuebunny/crossref_metadata_2025 huggingface dataset:
Processes Involved in Mathematical Problem Solving
Authors: Kantowski Mary Grace
Published: August 2020

The investigation was a longitudinal exploratory study of processes involved in solving mathematics problems as problem-solving ability developed under heuristic instruction in geometry. A clinical methodology was employed. The consistent use of heuristics and the regular patterns of analysis and synthesis were noted in the solutions of problems with process-product scores above the subject's own median. In most cases the tendency to use heuristics increased as problem-solving ability developed. A direction for problem-solving research is suggested and hypotheses for future studies, both clinical and experimental, are discussed.
Begle Revisited: Teacher Knowledge and Student Achievement in Algebra
Authors: Eisenberg Theodore A.
Published: August 2020

This study investigated the relationship between a teacher's knowledge of algebra and student performance. Twenty-eight Algebra I teachers and their 807 students took part in the study. Regression analysis was used to predict for each teacher an “expected” score for teaching algebraic concepts and skills. The difference between the observed score and the expected score was called “teacher effect.” The effect scores (one for algebraic concepts, the other for skills) were correlated with the teacher's knowledge of the real number system and other related algebraic structures, length of service, college mathematics grade point average, and the number of postcalculus courses taken. The only significant correlation obtained was between the teacher's knowledge of algebraic structures and the number of postcalculus courses.
Brief Reports: Certain School and Pupil Characteristics and Mathematics Test Results in Wisconsin
Authors: Coulson William F. , Howe Trevor G.
Published: August 2020

The Wisconsin Laboratory School Mathematics Committee prepared mathematics tests for Grades I through 6 that were administered throughout Wisconsin in 1969. These tests were based on behavioral objectives in Guidelines to Mathematics: K–6 (1967) published by the Department of Public Instruction of the state of Wisconsin. A comprehensive analysis of the mathematics test data was prepared by Coulson (1973). This report is a summary and selection of results from Coulson's study.
Research on Mathematics Education Reported in 1976
Authors: Suydam Marilyn N. , Weaver J. F.
Published: August 2020

This is the seventh annual listing of research on mathematics education published in JRME. The research for K–12 is organized alphabetically by author(s) within three categories—research summaries, journal-published reports, and dissertation abstracts. The subset of Piagetian-oriented research is listed separately in each of the latter two divisions. The K–12 listing is followed by references to articles and dissertations at the college and other postsecondary levels. All entries are annotated this year.
The Relationship between the Mathematical Structure of Euclidean Transformations and the Spontaneously Developed Cognitive Structures of Young Children
Authors: Moyer John C.
Published: August 2020

Preschool, kindergarten, first-, second-, and third-grade children performed a series of tasks involving two-dimensional isometries to determine if the spontaneous, intuitive cognitive structures of Euclidean transformations develop in accordance with some known mathematical organization of these ideas. Results confirmed that cognitive ability is in accord with mathematical structure in two areas: (a) explicit awareness of the physical motion associated with a translation or reflection neither helped nor hindered a child's ability to perform the transformation task; (b) the topological-like property of “surrounding” was significantly important for children regardless of age, although the use of more complex systems of relations increased with age. However, results also indicate that cognitive development departs from mathematical structure in that (a) the translations were at least as easy as the reflections, which were easier than the rotations, and (b) performance on rotations was better if the associated motion was made explicit. A final result confirmed that grade level was related to performance on the tasks, but IQ was not.
Brief Reports: Children's Difficulties on Quantitative Tasks: Are They Simply a Misunderstanding of Relational Terms?
Authors: Brush Lorelei R. , Brett Leslie J. , Sprotzer Eve R.
Published: August 2020

Earlier research conducted by the author (Brush, 1978) showed that preschool children are very competent in performing elementary arithmetic tasks. Where errors were made, it seemed that children were assessing differences in quantity in global terms such as those recounted by Piaget (1952) when di scussing children's answers to tasks involving equivalence of quantities. Piaget claimed that task difficulty was not caused by a simple linguistic misunderstanding but was conceptual. This study was designed to investigate that claim, that is, to see whether or not children who make errors on simple quantitative tasks are merely misunderstanding the experimenter's language.
Set Comparison Tactics and Strategies of Children in Kindergarten, First Grade, and Second Grade
Authors: Gullen George E.
Published: August 2020

In a unique unbiased set comparison test, 90 children in kindergarten, first grade, and second grade used 5 different set comparison tactics and 12 different set comparison strategies (sequences of tactics) when making 12 comparisons of pairs of sets in terms of “more” or “same number.” The frequencies of set comparison tactics were found to be related to both the school grade levels of the children (p<.005) and the cardinal numbers of the sets being compared (p<.005) The numbers of correct comparisons were found to be related to the children's abilities to quantify correctly the sets being compared The frequencies of the set comparison strategies were found to be related to both the school grade levels of the children (p<.005) and the cardinal numbers of the sets being compared (p<.01)
Algorithms
Authors: Louridas Panos
Published: August 2020

An accessible introduction to algorithms, explaining not just what they are but how they work, with examples from a wide range of application areas.

Digital technology runs on algorithms, sets of instructions that describe how to do something efficiently. Application areas range from search engines to tournament scheduling, DNA sequencing, and machine learning. Arguing that every educated person today needs to have some understanding of algorithms and what they do, in this volume in the MIT Press Essential Knowledge series, Panos Louridas offers an introduction to algorithms that is accessible to the nonspecialist reader. Louridas explains not just what algorithms are but also how they work, offering a wide range of examples and keeping mathematics to a minimum.

After discussing what an algorithm does and how its effectiveness can be measured, Louridas covers three of the most fundamental applications areas: graphs, which describe networks, from eighteenth-century problems to today's social networks; searching, and how to find the fastest way to search; and sorting, and the importance of choosing the best algorithm for particular tasks. He then presents larger-scale applications: PageRank, Google's founding algorithm; and neural networks and deep learning. Finally, Louridas describes how all algorithms are nothing more than simple moves with pen and paper, and how from such a humble foundation rise all their spectacular achievements.
Education Crossing Borders
Authors: Fisher Dara R.
Published: August 2020

The chronicle of a ten-year partnership between MIT and Singapore's Education Ministry that shows cross-border collaboration in higher education in action.

In this book, Dara Fisher chronicles the decade-long collaboration between MIT and Singapore's Education Ministry to establish the Singapore University of Technology and Design (SUTD). Fisher shows how what began as an effort by MIT to export its vision and practices to Singapore became an exercise in adaptation by actors on the ground. As cross-border higher education partnerships become more widespread, Fisher's account of one such collaboration in theory and practice is especially timely.

Despite the prevalence of cross-border higher education initiatives, there is little understanding of how these partnerships work. This book fills the gap, offering an in-depth ethnographic case study that draws on organizational behavior literature for theoretical support. Fisher describes the sometimes divergent priorities of the Singapore government and MIT as planning began in 2007; chronicles how the founding faculty, staff, and students sought to shape the new university; shows that MIT left decision making to local actors on matters it regarded as low priority (only to discover later that some of these decisions did not align with MIT values); and examines SUTD's efforts to build an independent identity as Singapore's fourth major public university within the Singaporean higher education ecosystem. Finally, Fisher develops a framework for understanding how MIT's identity and practices were communicated to and then localized by Singaporeans, examining this in terms of politics, culture, institutions, and individuals.
Play like a Feminist.
Authors: Chess Shira
Published: August 2020

Why video games need feminism and feminism needs video games.

“You play like a girl”: it's meant to be an insult, accusing a player of subpar, un-fun playing. If you're a girl, and you grow up, do you “play like a woman”—whatever that means? In this provocative and enlightening book, Shira Chess urges us to play like feminists. Furthermore, she urges us to play video games like feminists. Playing like a feminist is empowering and disruptive; it exceeds the boundaries of gender yet still advocates for gender equality. Playing like a feminist offers a new way to think about how humans play —and also a new way to think about how feminists do their feministing. Chess argues that feminism needs video games as much as video games need feminism.

Video games, Chess tells us, are primed for change. Roughly half of all players identify as female, and Gamergate galvanized many of gaming's disenfranchised voices. Games themselves are in need of a creative platform-expanding, metaphysical explosion; feminism can make games better. Chess reflects on the importance of play, and playful protest, and how feminist video games can help us rethink the ways that we tell stories. She proposes “Women's Gaming Circles”—which would function like book clubs for gaming—as a way for feminists to take back play. (An appendix offers a blueprint for organizing a gaming circle.) Play and games can be powerful. Chess's goal is for all of us—regardless of gender orientation, ethnicity, ability, social class, or stance toward feminism—to spend more time playing as a tool of radical disruption.
How to Grow a Robot
Authors: Lee Mark H.
Published: August 2020

How to develop robots that will be more like humans and less like computers, more social than machine-like, and more playful and less programmed.

Most robots are not very friendly. They vacuum the rug, mow the lawn, dispose of bombs, even perform surgery—but they aren't good conversationalists. It's difficult to make eye contact. If the future promises more human-robot collaboration in both work and play, wouldn't it be better if the robots were less mechanical and more social? In How to Grow a Robot, Mark Lee explores how robots can be more human-like, friendly, and engaging.

Developments in artificial intelligence—notably Deep Learning—are widely seen as the foundation on which our robot future will be built. These advances have already brought us self-driving cars and chess match–winning algorithms. But, Lee writes, we need robots that are perceptive, animated, and responsive—more like humans and less like computers, more social than machine-like, and more playful and less programmed. The way to achieve this, he argues, is to “grow” a robot so that it learns from experience—just as infants do.

After describing “what's wrong with artificial intelligence” (one key shortcoming: it's not embodied), Lee presents a different approach to building human-like robots: developmental robotics, inspired by developmental psychology and its accounts of early infant behavior. He describes his own experiments with the iCub humanoid robot and its development from newborn helplessness to ability levels equal to a nine-month-old, explaining how the iCub learns from its own experiences. AI robots are designed to know humans as objects; developmental robots will learn empathy. Developmental robots, with an internal model of “self,” will be better interactive partners with humans. That is the kind of future technology we should work toward.
Mutation density changes in SARS-CoV-2 are related to the pandemic stage but to a lesser extent in the dominant strain with mutations in spike and RdRp
Authors: Eskier Doğa , Suner Aslı , Karakülah Gökhan , Oktay Yavuz
Published: August 2020

Since its emergence in Wuhan, China in late 2019, the origin and evolution of SARS-CoV-2 have been among the most debated issues related to COVID-19. Throughout its spread around the world, the viral genome continued acquiring new mutations and some of them became widespread. Among them, 14408 C>T and 23403 A>G mutations in RdRp and S, respectively, became dominant in Europe and the US, which led to debates regarding their effects on the mutability and transmissibility of the virus. In this study, we aimed to investigate possible differences between time-dependent variation of mutation densities (MDe) of viral strains that carry these two mutations and those that do not. Our analyses at the genome and gene level led to two important findings: First, time-dependent changes in the average MDe of circulating SARS-CoV-2 genomes showed different characteristics before and after the beginning of April, when daily new case numbers started levelling off. Second, this pattern was much delayed or even non-existent for the “mutant” (MT) strain that harbored both 14408 C>T and 23403 A>G mutations. Although these differences were not limited to a few hotspots, it is intriguing that the MDe increase is most evident in two critical genes, S and Orf1ab, which are also the genes that harbor the defining mutations of the MT genotype. The nature of these unexpected relationships warrants further research.
The Safety and Efficacy of Total Laparoscopic Distal Gastrectomy With Delta-Shaped Anastomosis Compared With Laparoscopic-Assisted Distal Gastrectomy
Authors: Gao Y. B. , Jin W. D. , Cao J. , Zhang Z. Y. , Cai X. , Fu T. , Ma L. T.
Published: August 2020

Aim:

To evaluate the safety and short-time benefits of enhanced recovery after surgery on hospital stay, recovery of gastrointestinal function and complications after total laparoscopic distal gastrectomy (TLDG) with delta-shaped anastomosis, comparing with laparoscopic-assisted distal gastrectomy (LADG).

Methods:

A retrospective analysis was performed in 134 patients with gastric cancer who were treated at Wuhan General Hospital of Guangzhou Military Area Command from November 2013 to August 2015. A total of 70 patients underwent TLDG, and 64 patients underwent LADG. All patients were performed elective standard D2 total gastrectomy by 1 group of experienced surgeons. The short-term therapeutic benefits, including duration of flatus and defecation, postoperative pain, duration of postoperative stay, and complications between the 2 groups were analyzed.

Results:

Compared with LADG, TLDG had shorter time to the first flatus (74.09 ± 11.08 h versus 84.11 ± 12.18 h, P < 0.001), earlier postoperative liquid diet intake (98.83 ± 10.63 h versus 108.58 ± 13.08 h, P < 0.001), less dosage of pain killers (2.01 ± 0.85 versus 2.41 ± 0.85, P = 0.009), faster recovery with a shorter postoperative hospital stay (8.14 ± 0.3.43 d versus 9.97 ± 4.53 d, P = 0.009), There were no significant difference in operation time, blood loss, the number of lymph nodes retrieved, or the incidence of postoperative complications (anastomotic bleeding or leakage, wound infection, digestive tract dysfunction, thrombosis, or death; P > 0.05).

Conclusions:

TLDG with delta-shaped anastomosis is a safe and effective fast-tract surgical approach for earlier gastric cancer, which would probably achieve the short-term curative effect. Further studies based on larger volumes and long-term effects are required to confirm these findings.
Isolation of two variants of native one‐chain tissue plasminogen activator
Authors: Rånby Mats , Bergsdorf Nils , Pohl Gunnar , Wallén Per
Published: July 2002

The native one‐chain tissue plasminogen activator from the human melanoma cell line (Bowes) occurs in two variants as demonstrated by sodium dodecylsulphate—polyacrylamide gel electrophoresis of reduced and carboxymethylated samples. The two variants were isolated by affinity chromatography on arginine—Sepharose using a guanidinium—HCl gradient. in the order of elution, the variants were designated tissue plasminogen activator I and II. Variant I was found to be 3000 M
r larger than variant II and the difference was found to reside in the N‐terminal half of the molecule. No substantial difference in carbohydrate content nor in enzymatic activity was demonstrated.
A hypothesis for the mechanism of sodium channel opening by batrachotoxin and related toxins
Authors: Kosower Edward M.
Published: July 2002

FEBS Lett. (1983) 155, 245; ibid. 157, 144; Biophys. J. (1983) 45, in press).
Product of extracellular‐superoxide dismutase catalysis
Authors: Marklund Stefan L.
Published: July 2002

Extracellular‐superoxide dismutase is a tetrameric enzyme containing four copper atoms. It has previously been shown to catalyse the decay of the Superoxide radical, but the resulting product was not determined. In a xanthine oxidase‐xanthine system in which about 30% of the electron flux resulted in Superoxide radical formation, accumulation of hydrogen peroxide was determined. Catalysis of Superoxide radical decay by extracellular‐superoxide dismutase was found to result in hydrogen peroxide formation. The catalysed reaction is thus identical to those of previously investigated Superoxide dismutases. Human manganese superoxide dismutase was also found to dismute the Superoxide radical to hydrogen peroxide and water.
Purification of two astroglial growth factors from bovine brain
Authors: Pettmann B. , Weibel M. , Sensenbrenner M. , Labourdette G.
Published: July 2002

Growth factor
Cell culture
Glial cell
Nucleotide sequence divergence and functional constraint in VIP precursor mRNA evolution between human and rat
Authors: Nishizawa Mikio , Hayakawa Yumiko , Yanaihara Noboru , Okamoto Hiroshi
Published: July 2002

Rat VIP
Rat PHI‐27
VIP precursor
VIP precursor mRNA
Human PHM‐27
Sequence homology
Induction of protein synthesis in response to ultraviolet light, nalidixic acid and heat shock in the cyanobacterium Phormidium laminosum
Authors: Nicholson Paul , Osborn Rupert W. , Howe Christopher J.
Published: July 2002

Synthesis of three polypeptides (43, 34 and 26 kDa) was enhanced or induced in the thermophilic cyanobacterium Phormidium laminosum following irradiation with UV light. Synthesis of several polypeptides was also enhanced/induced following treatment with nalidixic acid. Three had similar molecular masses to those induced by UV. One of these (43 kDa) was also apparently enhanced following prolonged heat shock, as were a number of other polypeptides with a wide range of molecular masses. The specific induction of the 34 and 26 kDa polypeptides following DNA damage and inhibition of replication suggests that they may be involved in DNA repair and, possibly, also in recombination.
Cloning and expression of cDNA encoding human basic fibroblast growth factor
Authors: Kurokawa Tsutomu , Sasada Reiko , Iwane Makoto , Igarashi Koichi
Published: July 2002

A cDNA encoding human basic fibroblast growth factor (bFGF) was isolated from a human foreskin fibroblast cDNA library. The cDNA, 4 kilobases in size, had a coding sequence, 5' and 3' untranslated regions, and a poly(A) chain. Isolation of additional cDNA clones that had a short 3' untranslated region suggested the presence of multiple mRNA forms. By Northern blot analysis, at least five bFGF mRNA species were detected in cultured fibroblast cells. Transfection of the cDNA to COS cells resulted in the detection of mitogenic activity in the culture medium of the transfected cells, suggesting that a part of the synthesized protein might be secreted from cells despite its unusual short signal sequence.
Release of clotting factors from photosensitized endothelial cells: A possible trigger for blood vessel occlusion by photodynamic therapy
Authors: Ben-Hur E. , Heldman E. , Crane S.W. , Rosenthal I.
Published: July 2002

Photodynamic treatment of solid tumors results in the occlusion of blood vessels in the treated tissue. We hypothesize that this process is triggered by the release of one or more clotting factors from the photodamaged endothelial cells. Experimental evidence is presented that immediately after photodynamic treatment, cultured endothelial cells start releasing clotting factors into the medium in a dose range of minimal cytotoxicity.
Reactive oxygen species induce antigenic changes in DNA
Authors: Blount S. , Griffiths H.R. , Lunec J.
Published: July 2002

Reactive oxygen species (ROS) are released at sites of inflammation during the respiratory burst which accompanies the phagocytic process. Using an in vitro system to simulate this process we have shown that ROS induce antigenic changes in DNA. More specifically, results of experiments using ROS scavengers have shown that hydroxyl radicals produced in close proximity to DNA‐bound metal ions play a predominant role. ROS‐mediated attack resulted in increased binding of anti‐DNA antibodies to the denatured DNA. These changes were detected using IgG, IgA and IgM isotype binding to antibodies in systemic lupus erythematosus sera. Of these the IgA isotype was most discriminating in its detection of hydroxyl radical‐induced damage.
Interleukin‐1β induces synthesis and secretion of interleukin‐6 in human chondrocytes
Authors: Bender S. , Haubeck H.-D. , Van de Leur E. , Dufhues G. , Schiel X. , Lauwerijns J. , Greiling H. , Heinrich P.C.
Published: July 2002

Increased concentrations of interleukin‐6 (IL‐6) have been found in the synovial fluid of patients with osteoarthritis, rheumatoid arthritis and crystal‐related joint deseases. It is therefore of great interest to identify the cells responsible for the production of IL‐6, and to investigate whether IL‐6 plays a role in the pathogenesisof degenerative or inflammatory joint diseases. Here we show that human interleukin‐1β (IL‐1β) induces IL‐6 synthesis and secretion in differentiated human chondrocytes. In organ cultures resembling closely the in vivo system 106 chondrocytes incubated with 100 units of interleukin‐1β per ml of medium led to the release of 6 × 103 units of IL‐6 within 24 h. Chondrocytes cultured in agarose or as monolayers similary incubated with IL‐1β produced even higher amounts of IL‐6: 70 × 103 units per 106 cells within 24 h. The induction of IL‐6 synthesis by IL‐1β was also shown at the mRNA level. IL‐6 secreted by stimulated chondrocytes showed heterogeneity upon Western blot analysis.
The delivery of foreign genes into fertilized fish eggs using high‐velocity microprojectiles
Authors: Zelenin Alexander V. , Alimov Andrey A. , Barmintzev Vladimir A. , Beniumov Alexei O. , Zelenina Inessa A. , Krasnov Alexei M. , Kolesnikov Viktor A.
Published: July 2002

Fertilized eggs of loach (Misgurnus fossilis), rainbow trout (Salmo gairdneri) and zebrafish (Brachydanio rerio) were bombarded with high‐velocity tungsten microprojectiles covered with plasmid DNA containing sequences of β‐galactosidase and neomycin phosphotransferase genes. About 70% of the eggs survived the bombardment. The activity of both transferred genes was revealed in the fish developed from the bombarded eggs. Neomycin phosphotransferase gene sequences were detected by means of PCR amplification and Southern hybridization in the total DNA of zebrafish that survived after G418 treatment.
Sequence similarity between opioid peptide precursors and DNA‐binding proteins
Authors: Bakalkin Georgy Ya. , Ponomariev Dmitry , Sarkisyan Raphik A. , Terenius Lars
Published: July 2002

The opioid peptide precursors, preprodynorphin and preproenkephalin show structure similarity with a transcription factor, hunchback and the putative helix‐loop‐helix DNA‐binding proteins, lil‐1, tal and twist. Segments with similarity contain the three enkephalin sequences in preprodynorphin and one in preproenkephalin which are present within heptapeptide repeats characteristic of an α‐helical coiled‐coil structure distinctive of an amphipathic helix‐loop‐helix DNA‐binding motif, Hunchback and the opioid prohormones also have cystein‐rich regions characteristic of zinc‐finger domains in common.
Endosomal association of a protein phosphatase with high dephosphorylating activity against a coronavirus nucleocapsid protein
Authors: Mohandas Devaki V. , Dales Samuel
Published: July 2002

On the assumption that dephosphorylation of the neurotropic coronavirus JHM (JHMV) nucleocapsid protein (N) may be connected with initiation of the infectious cycle we searched for a relevant host enzyme activity. Analysis of subcellular fractions from L‐2 murine fibroblasts, separated by dual Percoll density gradients, revealed the presence of a phosphoprotein phosphatase (PPPase), co‐sedimenting with the endososomal/prelysosomal material, which possesses high activity against N. With purified [22P]N as substrate it was demonstrated that this PPPase, distinguishable from acid and alkaline phosphatases, acts optimally at neutral pH in the presence of Mn2+ following treatment with a detergent. Complete inhibition with okadaic acid at 0.9–4.5 μM but not at 1–10 nM relegates this PPase to a type I protein phosphatase. Similar PPPase activity for N was present in the endosome fraction of a rat Roc‐1 astrocytoma‐oligodendrocyte cell line and in homogenates of brain and cultured oligodendrocytes. Our data suggest that the phosphorylated N of the inoculum may be modified by the endosomal PPPase in host cells, including those from the CNS so as to facilitate the JHMV infectious process.
Expression of an inwardly rectifying K+ channel from rat basophilic leukemia cell mRNA in Xenopus oocytes
Authors: Lewis Deborah L. , Ikeda Stephen R. , Aryee Dave , Joho Rolf H.
Published: July 2002

Rat basophilic leukemia cells (RBL‐2H3) have previously been shown to contain a single type of voltage‐activated channel, namely an inwardly rectifying K+ channel, under normal recording conditions. Thus, RBL‐2H3 cells seemed like a logical source of mRNA for the expression cloning of inwardly rectifying K+ channels. Injection of mRNA isolated from RBL‐2H3 cells into Xenopus oocytes resulted in the expression of an inward current which (1) activated at potentials negative to the K+ equilibrium potential (EK), (2)decreased in slope conductance near EK, (3) was dependent on [K+]o and (4) was blocked by external Ba2+ and Cs+. These properties were similar to those of the inwardly rectifying K+ current recorded from RBL‐2H3 cells using whole‐cell voltage clamp. Injection of size‐fractionated mRNA into Xenopus oocytes revealed that the current was most strongly expressed from the fraction containing mRNA of approximately 4–5 kb. Expression of this channel represents a starting point for the expression cloning of a novel class of K+ channels.
Neurotransmitter transporters A novel family of integral plasma membrane proteins
Authors: Schloss Patrick , Mayser Wolfgang , Betz Heinrich
Published: July 2002

The re‐uptake of neurotransmitters into the nerve terminal terminates synaptic transmission at most central synapses and constitutes a key step in the modulation of synaptic efficacy. Recently, the cloning of several Na+‐driven neurotransmitter transporters has resulted in the description of a novel family of homologous membrane proteins, each with 12 transmembrane segments. These transporters constitute major targets of widely used drugs, and modulation of transporter gene expression and/or activity may represent an important substrate for plasticity in the nervous system.
Prooxidant role of vitamin E in copper induced lipid peroxidation
Authors: Maiorino Matilde , Zamburlini Adriana , Roveri Antonella , Ursini Fulvio
Published: July 2002

When exposed to Cu2+, α‐tocopherol, in detergent dispersion, is rapidly oxidised. Moreover, if phospholipids and traces of their hydroperoxide derivatives are included in these dispersions, Cu2+ initiates lipid peroxidation, the rate of which is dramatically stimulated by α‐tocopherol. The observation that the rate of α‐tocopherol consumption is identical in the absence and in the presence of lipids undergoing peroxidation, apparently rules out any antioxidant effect. These results are consistent with a prooxidant effect of vitamin E, mediated by its capability to reduce Cu2+ to Cu+ which, in turn, produces, from lipid hydroperoxides, the highly reactive alkoxyl radicals. Present data highlight the risk of misleading results in interpreting the significance of lags in peroxidation of LDL challenged with Cu2+.
Cloning of CRP2, a novel member of the cysteine‐rich protein family with two repeats of an unusual LIM/double zinc‐finger motif
Authors: Okano Ichiro , Yamamoto Takeshi , Kaji Akira , Kimura Toru , Mizuno Kensaku , Nakamura Toshikazu
Published: July 2002

The cDNA coding for a novel member of the cysteine‐rich protein family was isolated from a rat brain cDNA library. It encodes a protein, denoted cysteine‐rich protein 2 (CRP2), of 208 amino acid residues containing two tandem repeats of an unusual LIM/double zinc‐finger‐like motif. The ubiquitous tissue distribution and high level of expression of CRP2 mRNA suggest an important role for CRP2 in cell functions.
The role of 2', 3'‐cyclic phosphodiesters in the bovine pancreatic ribonuclease A catalysed cleavage of RNA: intermediates or products?
Authors: Cuchillo Claudi M. , Parés Xavier , Guasch Alícia , Barman Tom , Travers Franck , Nogués M.Victòria
Published: July 2002

There is a considerable degree of ambiguity in the literature regarding the role of the 2',3'‐cyclic phosphodiesters formed during the reaction of RNA cleavage catalysed by ribonuclease. Usually the reaction is considered to take place in two steps: in the first step there is a transphosphorylation of the RNA 3',5'‐phosphodiester bond broken yielding a 2',3'‐cyclic phosphodiester which in the second step is hydrolysed to a 3'‐nucleotide. Although in many occasions, either explicitly or implicitly, the reaction is treated as taking place sequentially, this is not the case as it has been shown that the 2',3'‐phosphodiesters are actually released to the medium as true products of the reaction and that no hydrolysis of these cyclic compounds takes place until all the susceptible 3',5'‐phosphodiester bonds have been cyclised. Comparison of the hydrolysis and alcoholysis of the 2',3'‐phosphodiesters catalysed by RNase A indicates that the hydrolysis reaction has to be considered formally as a special case of the transphosphorylation back reaction in which the R group of the R‐OH substrate is just H. It is thus concluded that the 2',3'‐cyclic phosphodiesters formed in the ribonuclease A reaction are true products of the transphosphorylation reaction and not intermediates as usually considered.
Regulation by growth factors (IGF‐I, b‐FGF and TGF‐β) of protooncogene mRNA, growth and differentiation of bovine adrenocortical fasciculata cells
Authors: Viard I. , Jaillard C. , Saez J.M.
Published: July 2002

Nuclear proto‐oncoproteins have been implicated in the regulation of gene expression by peptidic hormones and growth factors during cell proliferation and differentiation. In the present study we have investigated in bovine adrenal cells (BAC) the effects of basic fibroblast growth factor (b‐FGF), insulin‐like growth factor 1 (IGF‐I) and transforming growth factor β (TGF‐/β) on c‐jun, jun‐B and c‐fos mRNA levels and on cell growth and differentiation. Factors able to enhance the three proto‐oncogenes (IGF‐I, b‐FGF and angiotensin II (A‐II)) stimulate cell growth, whereas those inhibiting cell growth (TGF‐β and ACTH) decrease c‐jun mRNA level. These results suggest that expression of c‐jun may be required to induce cell proliferation. The relation between proto‐oncogenes and the expression of differentiated functions appears to be more complex. Whereas IGF‐I, b‐FGF and A‐II increase the three nuclear proto‐oncogenes, the effects of IGF‐I and b‐FGF on cytochrome P450 17α‐hydroxylase mRNA levels are opposite to those of A‐II. On the other hand, while TGF‐β and A‐II have inhibitory effects on P450 17 α mRNA level, they have opposite effects on c‐jun mRNA.
Cloning and functional expression of a brain G‐protein‐coupled ATP receptor
Authors: Webb Tania E. , Simon Joseph , Krishek Belinda J. , Bateson Alan N. , Smart Trevor G. , King Brian F. , Burnstock Geoffrey , Barnard Eric A.
Published: July 2002

A cDNA encoding a novel member of the G‐protein‐coupled receptor (GCR) superfamily, an ATP receptor, has been isolated from an embryonic chick whole brain cDNA library by hybridization screening. The encoded protein has a sequence of 362 amino acids (41 kDa) and shares no more than 27% amino acid identity with any known GCR. When expressed as a complementary RNA (cRNA) in Xenopus oocytes a slowly‐developing inward current was observed in response to application of ATP. The pharmacology of this expressed protein defines it as a P2Y purinoceptor.
Pulmonary surfactant is a potential endogenous inhibitor of proteolytic activation of Sendai virus and influenza A virus
Authors: Kido Hiroshi , Sakai Kentaro , Kishino Yasuo , Tashiro Masato
Published: July 2002

The pathogenicities of influenza viruses and paramyxoviruses have been proposed to be primarily determined by a host cell protease(s) that activates viral infectivity by proteolytic cleavage of the envelope glycoproteins. We recently isolated a trypsin‐type endoprotease, named tryptase Clara, from rat bronchial and bronchiolar epithelial Clara cells, which is secreted into the airway lumen and activates Sendai virus and influenza A virus proteolytically. We report here that surfactant in the bronchial fluid inhibited tryptase Clara specifically, having a K
i value of 0.13 μM, and inhibited the proteolytic activations by tryptase Clara in vitro and in organ cultures of rat lung. Intranasal infection of rats with Sendai virus was shown to stimulate secretion of tryptase Clara without changing the amount of surfactant in the bronchial lumen, resulting in a preferable condition for proteolytic viral activation and multiplication.
Kinetics and equilibria of S‐nitrosothiol—thiol exchange between glutathione, cysteine, penicillamines and serum albumin
Authors: Meyer David J. , Kramer Harry , Özer Nazmi , Coles Brian , Ketterer Brian
Published: July 2002

The kinetics and equilibria of S‐nitrosothiol‐thiol (SNO—SH) exchange reactions were determined using differential optical absorption. At pH 7.4 and 37°C, k
2 values ranged from 0.9 M−1 · s−1 for the reaction between S‐nitroso‐glutathione (GSNO) and N‐acetyl‐penicillamine, and up to 279 M−1 · s−1 for the exchange between S‐nitroso‐penicillamine (penSNO) and GSH. SNO—SH exchange involving GSH/GSNO and cysteine/cySNO was relatively rapid, k
2 approx. 80 M−1 · s−1 with an equilibrium constant slightly in favour of GSNO. GSNO was strongly favoured in equilibrium with penSNO, k
eq 0.0039. In the case of SNO—SH exchange between S‐nitroso human serum albumin (albSNO) and GSH or cysteine k
2 values were 3.2 and 9.1 M−1 · s−1, respectively. The results show that the initial rate of SNO—SH exchange between physiological albSNO (7 μM) and venous plasma levels of GSH and cysteine is very slow, < 1%/min. On the other hand, if a nitrosothiol such as cySNO were to enter a cell, it would be rapidly converted to GSNO (43%/s).
1‐Acyl‐2‐lysophosphatidylcholine transport across the blood—retina and blood—brain barrier
Authors: Alberghina Mario , Infarinato Salvatore , Anfuso Carmelina D. , Lupo Gabriella
Published: July 2002

The transport of lysophospholipids through the rat blood—retina and blood—brain barrier was determined by using radioactive 1‐palmitoyl‐2‐lysophosphatidylcholine (Pam‐lysoPtdCho) and by measuring the uptake of this labeled compound into the retina and various brain regions after short in situ carotid perfusion. The transport was not affected by probenecid (0.25 mM), but it was inhibited, in a dose‐dependent manner, by circulating albumin which is able to bind tightly to lysophosphatidylcholine and lowered the availability of the latter for tissue extraction. Radiotracer transfer in the retina was higher than in brain regions. The permeability‐surface area products (PS) changed with the inclusion of unlabeled Pam‐lysoPtdCho, showing that transport across retinal and brain microvessels is mainly saturable. The data provided an estimate of transport constants (V
max, K
m and non‐saturable constant K
d). However, we could not distinguish whether this saturable process represents the saturation of a transport carrier or simple passive diffusion followed by the saturation of enzymatic reactions. In brain tissue lipid extract, 20 s after carotid injection, radiolabel was associated by 45% to unmetabolized Pam‐lysoPtdCho. Partial acylation to phosphatidylcholine, as well as hydrolysis and redistribution of the fatty acyl moiety into main phospholipid classes also occurred. The present results, compared to our previous data, indicate that PamlysoPtdCho is transported faster and/or in greater amounts than unesterified fatty acids.
Oxidative degradation of non‐phenolic lignin during lipid peroxidation by fungal manganese peroxidase
Authors: Bao Wuli , Fukushima Yaichi , Jensen Kenneth A. , Moen Mark A. , Hammel Kenneth E.
Published: July 2002

A non‐phenolic lignin model dimer, 1‐(4‐ethoxy‐3‐methoxyphenyl)‐2‐phenoxypropane‐1,3‐diol, was oxidized by a lipid peroxidation system that consisted of a fungal manganese peroxidase, Mn(II), and unsaturated fatty acid esters. The reaction products included 1‐(4‐ethoxy‐3‐methoxyphenyl)‐1‐oxo‐2‐phenoxy‐3‐hydroxypropane and 1‐(4‐ethoxy‐3‐methoxyphenyl)‐1‐oxo‐3‐hydroxypropane, indicating that substrate oxidation occurred via benzylic hydrogen abstraction. The peroxidation system depolymerized both exhaustively methylated (non‐phenolic) and unmethylated (phenolic) synthetic lignins efficiently. It may therefore enable white‐rot fungi to accomplish the initial delignification of wood.
A point mutation within the ATP‐binding site inactivates both catalytic functions of the ATP‐dependent protease La (Lon) from Escherichia coli
Authors: Fischer Heinrich , Glockshuber Rudi
Published: July 2002

A point mutant in the ATP‐binding motif (GPPGVGK362T) of the ATP‐dependent protease La from Escherichia coli was investigated in which the lysine at position 362 was replaced by an alanine. The catalytic efficiency of the K362A mutant is at least two orders of magnitude lower than that of wild‐type protease La due to a decreased Vmax and an increased K
M for ATP. Simultaneously, the peptidase activity of La K362A is almost completely eliminated. Since selective inactivation of the peptidase activity of La does not affect its intrinsic ATPase activity, coupling of proteolysis with ATP hydrolysis is only uni‐directional in this energy‐dependent protease.
Interleukin‐13 stimulates interleukin‐6 production by human keratinocytes
Authors: Derocq J.-M. , Segui M. , Poinot-Chaze C. , Minty A. , Caput D. , Ferrara P. , Casellas P.
Published: July 2002

Interleukin‐13 (IL‐13) is a recently described human lymphokine which is produced by activated T‐cells. Its effect on the production of IL‐6 by normal keratinocytes and keratinocyte cell lines of human origin was studied and compared to that of IL‐4. IL‐13, similarly to IL‐4, stimulated IL‐6 expression by these cells in a dose‐ and time‐dependent manner. Contamination with endotoxin was excluded by the use of polymyxin B and heat‐inactivated cytokines. Further, we showed that IL‐13, like IL‐4, not only stimulated IL‐6 production but also was able to induce overexpression of this cytokine in response to an inflammatory signal such as lipopolysaccharide (LPS). In a previous study, we demonstrated that IL‐13, by inhibiting IL‐6 and other cytokines produced by monocytes, exhibited an ‘anti‐inflammatory profile’ comparable to that displayed by IL‐4. In contrast, we show here that IL‐13, by stimulating IL‐6 production by keratinocytes, may favour the installation of an inflammatory process at a local level and, here again, it acted like IL‐4. Therefore, according to the type of target cell, these two ‘TH2 type’ cytokines induce similar opposing effects on IL‐6 production and are likely to be important cytokines in the regulation of inflammation at both systemic and local levels.
Phage antibodies against an unstable hapten: Oxygen sensitive reduced flavin
Authors: Bruggeman Yvonne E. , Boogert Anja , van Hoek Arie , Jones Peter T. , Winter Greg , Schots Arjen , Hilhorst Riet
Published: July 2002

It is difficult to raise antibodies against haptens and antigens that are unstable under the physiological conditions of the serum. Here we have used a phage antibody library to isolate antibody fragments against oxygen sensitive reduced flavin, by selection of the phage under anaerobic and reducing conditions at pH 5 and a pre‐elution step with the oxidized flavin. The binding of the reduced hapten to one of the antibody fragments was characterised by time‐resolved polarised fluorescence, and shown to be highly specific for the reduced flavin.
Ectopic expression of CHOP (GADD153) induces apoptosis in M1 myeloblastic leukemia cells
Authors: Matsumoto Makoto , Minami Masashi , Takeda Kiyoshi , Sakao Yoshimitsu , Akira Shizuo
Published: July 2002

CHOP (GADD153) is a member of the C/EBP family and a stress‐induced protein. To investigate the role of CHOP in cellular growth, we expressed CHOP conditionally in M1 myeloblastic leukemia cells that do not express p53 protein. More than 60% of M1 cells died through apoptosis 72 h after CHOP induction. Site‐directed mutagenesis revealed that this process requires leucine zipper domain but neither intact basic region nor trans‐activation domain. CHOP‐mediated apoptosis accompanied downregulation of bcl‐2 mRNA and overexpression of Bcl‐2 delayed the process. Our results indicate that CHOP can induce apoptosis in a p53‐independent manner.
Preoperative sonography in detecting small benign cystic teratomas
Authors: Caspi B. , Elchalal U. , Dgani R. , Appelman Z.
Published: July 2002

Identification of small ovarian benign cystic teratomas (dermoid cysts) is difficult and sometimes impossible by clinical findings alone. They may be missed even on direct inspection during laparotomy or laparoscopy. There are several typical ovarian sonographic signs which are known to occur frequently in women with benign ovarian cystic teratomas. High‐resolution sonography can identify the cysts based on their typical sonographic signs. Since these very small dermoid cysts are sometimes undetected by the naked eye during the operation, ultrasonography with particular attention to the signs is very important. We present three case reports that illustrate the problem and stress the contribution of preoperative sonography in the diagnosis and treatment of such cases.
Targeted disruption of NDST‐1 gene leads to pulmonary hypoplasia and neonatal respiratory distress in mice
Authors: Fan Guoping , Xiao Lei , Cheng Lu , Wang Xinhui , Sun Bo , Hu Gengxi
Published: July 2002

In order to address the biological function of GlcNAc N‐deacetylase/N‐sulfotransferase‐1 (NDST‐1), we disrupted the NDST‐1 gene by homologous recombination in mouse embryonic stem cells. The NDST‐1 null mice developed respiratory distress and atelectasis that subsequently caused neonatal death. Morphological examination revealed type II pneumocyte immaturity, which was characterized by an increased glycogen content and a reduced number of lamellar bodies and microvilli. Biochemical analysis further indicated that both total phospholipids and disaturated phosphatidylcholine were reduced in the mutant lung. Our data revealed that NDST‐1 was essential for the maturation of type II pneumocytes and its inactivation led to a neonatal respiratory distress syndrome.
Cloning, genomic organization, chromosomal assignment and expression of a novel mosaic serine proteinase: epitheliasin
Authors: Jacquinet Eric , Rao Narayanam V. , Rao Gopna V. , Hoidal John R.
Published: July 2002

We report the isolation of a cDNA encoding a novel murine serine proteinase, epitheliasin. The cDNA spans 1753 bp and encodes a mosaic protein with a calculated molecular mass of 53 529 Da. Its domains include a cytoplasmic tail, a type II transmembrane domain, a low‐density lipoprotein receptor class A domain, a cysteine rich scavenger receptor‐like domain and a serine proteinase domain. The proteinase portion domain shows 46–53% identity with mouse neurotrypsin, acrosin, hepsin and enteropeptidase. The gene, located in the telomeric region in the long arm of mouse chromosome 16, consists of 14 exons and 13 introns and spans approximately 18 kb. Epitheliasin is expressed primarily in the apical surfaces of renal tubular and airway epithelial cells.
Preparation of synthetic human islet amyloid polypeptide (IAPP) in a stable conformation to enable study of conversion to amyloid‐like fibrils
Authors: Higham Claire E. , Jaikaran Emma T.A.S. , Fraser Paul E. , Gross Michael , Clark Anne
Published: July 2002

Human synthetic islet amyloid polypeptide (hIAPP) is rapidly converted to β‐sheet conformation and fibrils in aqueous media. Optimal solubility conditions for hIAPP were determined by circular dichroism spectroscopy and transmission electron microscopy. hIAPP in trifluoroethanol or hexafluoro‐2‐isopropanol (HFIP) diluted in water or phosphate buffer (PB) exhibited random structure which was converted to β‐sheet and fibrils with time. hIAPP, solubilised in HFIP, filtered and lyophilised remained in stable random structure for up to 7 days in water; in PB, insoluble aggregates precipitated from which protofilaments and fibrils formed with time. This suggests that amorphous aggregates of hIAPP could initiate islet amyloidosis in vivo.
Characteristics and antifungal activity of a chitin binding protein from Ginkgo biloba
Authors: Huang Xu , Xie Wei-jun , Gong Zhen-zhen
Published: July 2002

An antifungal peptide from leaves of Ginkgo biloba, designated GAFP, has been isolated. Its molecular mass of 4244.0 Da was determined by mass spectrometry. The complete amino acid sequence was obtained from automated Edman degradation. GAFP exhibited antifungal activity towards Pellicularia sasakii Ito, Alternaria alternata (Fries) Keissler, Fusarium graminearum Schw. and Fusarium moniliforme. Its activities differed among various fungi. GAFP could also cause increased hyphal membrane permeabilization and a rapid alkalization of the medium when applied at 100 μg/ml to Pellicularia sasakii Ito hyphae. The amino acid sequence of GAFP shows characteristics of the cysteine/glycine‐rich chitin binding domain of many chitin binding proteins. The cysteine residues are well conserved.