bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Social Enterprises: A Bibliometric Analysis From 1991 to 2020
Authors: Alessandra Faraudello , Manuela Barreca , Daniel Iannaci , Federica Lanzara
Published: March 2021

The aim of this work is to provide, through a bibliometric analysis of the last 30 years of thematic literature, an overview on the contribution of social enterprises to the achievement of global goals.A bibliometric method has been used to analyze the characteristics, citation patterns and content of 3318 documents published in international academic journals, books review and chapters, editorial material and proceedings papers.Considering our findings, the bibliometric analysis has shown that there are journals that have had a greater production on the topic with an impact on research. Thanks to the work of the most impactful authors, it emerges that the case study is the most used method to demonstrate the centrality of social enterprises in social innovation. The analysis also shows that the centrality of the themes is linked to innovation, impact, management and performance, demonstrating the assumption that the driver of innovation in terms of social impact is given by these types of companies. The research also shows the keyword evolution through the years.Through the coding activity, it has also been possible to demonstrate that by transposing the global sustainability objectives to the local that the more in-depth ones are addressed on the issues of sustainable economy and fair, responsible and sustainable innovation, while there is much shortcoming regarding the achievement of gender equality, sustainable water management but even more on the reduction of inequality between nations. The latter is probably conditioned by the more global target and therefore not easily approachable to social enterprises.Research limitations/implications – The study shows a limitation, related to the adoption of the bibliometric method. However, it considers books review, chapters, papers published in international and academic journals, editorial materials, reviews and proceedings papers.Originality/value – This research shows that the interest on SDG and social enterprises has grown continuously in the last 30 years, especially in the last 5. The literature puts social enterprises at the center of social innovation by focusing on performance and management issues. Therefore, with the intention of mapping the studies that have been done in this regard, the study analyzed how research on local development coherence for global development has been addressed.
Van meelwormen, krekels, sprinkhanen en andere wijzen van uitlegging van Unierecht
Authors: Defares K.J.
Published: March 2021

Van meelwormen, krekels, sprinkhanen en andere wijzen van uitlegging van Unierecht

Op 1 oktober 2020 gaf het Hof van Justitie van de Europese Unie antwoord op de door de Franse Conseil d’État gestelde prejudiciële vraag of hele insecten, zoals wormen, sprinkhanen en krekels, een novel food zijn in de zin van Verordening (EG) nr. 258/97. Tegen de achtergrond van deze vraag besteedt advocaat-generaal Michal Bobek in zijn conclusie, naast de standaardmethoden van uitlegging van het Unierecht, aandacht aan de minder vaak toegepaste dynamische uitlegging. In deze bijdrage wordt derhalve nader stilgestaan bij de beperkingen en mogelijkheden van de toepassing van de dynamische interpretatie in de context van het Unierecht.

Conclusie A-G Bobek 9 juli 2020, zaak C-526/19, ECLI:EU:C:2020:552 (Entoma)
La regulación de los obstáculos epistemológicos en el aprendizaje de la evolución
Authors: Pérez Gastón , Gómez Galindo Alma Adrianna , González Galli Leonardo
Published: March 2021

Los obstáculos epistemológicos son modos de razonar que influyen en el aprendizaje de las ciencias. El trabajo didáctico sobre ellos implica el desarrollo de una vigilancia metacognitiva de manera de prestarles atención cada vez que se construye o se utiliza un modelo científico. En este trabajo caracterizaremos los modos de regulación de los obstáculos que surgieron durante el desarrollo de una secuencia didáctica para enseñar evolución en tres cursos de nivel medio. En particular propondremos ejemplos de la regulación de la teleología, uno de los obstáculos más importantes para la enseñanza de la biología. A partir de la construcción de categorías en base a la teoría fundamentada distinguimos tres modos de regular: un señalamiento del obstáculo en explicaciones de los estudiantes, una regulación de tipo individual compleja y una regulación de tipo social compleja.
¿Qué creen y que hacen profesores chilenos al enseñar biología en Educación Secundaria?
Authors: Ravanal Moreno Eduardo , López-Cortés Francisco , Amórtegui Cedeño Elias
Published: March 2021

El estudio explora el pensamiento del profesorado sobre lo que cree y lo que hace en sus diversas prácticas de enseñanza, todo ello mediante un cuestionario de escala Likert, una entrevista episódica y una observación de clase. Se analizaron las respuestas al cuestionario de 81 profesores de biología en servicio, 15 entrevistas episódicas y 9 clases de biología. Los resultados muestran que las creencias del profesorado sobre la enseñanza están en una perspectiva constructivista cuando piensan en lo que se debe y cree hacer, y en una perspectiva tradicional cuando se refiere a la explicación que sigue un libro de texto. El profesorado, además, concibe las prácticas de enseñanza como pautas de pensamiento y acción en tres dimensiones: disciplinar, didáctica y afectiva, siendo esta última la menos evidenciada en las clases observadas, las acciones de cuestionamiento las más representativas de la dimensión didáctica y la enseñabilidad del contenido científico como acción propia de la dimensión disciplinar.
El cambio climático en el bachillerato. Aportes pedagógicos para su abordaje
Authors: Bello Benavides Laura O. , Cruz Sánchez Gloria Elena , Meira Cartea Pablo Ángel , González Gaudiano Édgar Javier
Published: March 2021

La investigación presentada tiene como propósito conocer elementos de las representaciones sociales (RS) sobre cambio climático (CC) en estudiantes de bachillerato general y tecnológico del estado de Veracruz, y formular aportaciones pedagógicas orientadas a promover acciones ecociudadanas en estudiantes de este nivel. Se ha realizado una investigación cuantitativa con una muestra de 858 estudiantes, a través de un cuestionario demoscópico conformado por 43 preguntas cerradas. La hipótesis de investigación es: si no existe diferencia significativa entre las RS sobre CC en los dos grupos de estudio, cabe pensar que es la cultura común la que configura en mayor medida dicha RS. Los resultados muestran que este colectivo construye una RS del CC limitada a su dimensión biofísica con presencia de conceptos difusos, sin identificarse diferencias significativas entre las RS de los grupos.
Preconcepciones de pendiente en estudiantes de Educación Secundaria
Authors: Rivera López Martha Iris , Dolores Flores Crisólogo
Published: March 2021

En este artículo se reportan los resultados de una investigación cuyo objetivo fue identificar las preconcepciones de pendiente en estudiantes de Educación Secundaria. Se empleó una entrevista basada en tareas para la recolección de datos de 30 estudiantes de 10.º grado y el método de análisis temático para su respectivo análisis. Los resultados muestran que las preconcepciones de pendiente que manifiestan los estudiantes son la pendiente como la longitud de un segmento de recta, un objeto, una propiedad física, el valor del ángulo, la intersección de la recta con los ejes asociada a una expresión algebraica y el cociente de los valores de las intersecciones en el eje x e y. Aunque algunos estudiantes declararon una primera experiencia con el concepto, este conocimiento tuvo una mínima influencia en sus procedimientos y justificaciones.
Cardiology and COVID: A Bidirectional Association!
Authors: Kumar Rohit , Yadav Siddharth , Goel Ashish , Kumar Amit , Ish Pranav , Gupta Nitesh
Published: March 2021

The novel corona virus pandemic has the world in its grip and infection with COVID-19 has proven to be beyond a pulmonary disease [...]
Vascular Patterns on Narrow Band Imaging (NBI) Video Bronchoscopy of Lung Cancer Patients and Its Relationship with Histology: An Analytical Cross-Sectional Study
Authors: Chauhan Nishant , Elhence Poonam , Deokar Kunal , Dutt Naveen , Sharma Prem Prakash , Kuwal Ashok , Kumar Sunil , Niwas Ram
Published: March 2021

Introduction: Narrow band imaging (NBI) video bronchoscopy provides better visualisation of submucosal vascular patterns in malignant airway lesions compared to white light bronchoscopy. This analytical cross-sectional study was aimed to look for any relationship between these NBI vascular patterns and the histologic type of lung cancer. Material and methods: After screening 78 patients with suspected lung cancer, 53 subjects underwent video bronchoscopy. Thirty-two patients showing abnormal bronchial mucosa or endobronchial growth with any of the NBI vascular patterns on bronchoscopy were enrolled in the study. These abnormal areas were then biopsied and sent for histologic examination. Results: NBI bronchoscopy revealed a dilated tortuous vascular pattern in 54.8% of the patients, a non-specific pattern in 32%, a dotted pattern in 9.7% and an abrupt ending vessels pattern in 3.2% of the patients. We did not find any statistically significant relationship between a dilated tortuous pattern and squamous-cell carcinoma (p = 0.48), adenocarcinoma (p = 0.667) or small-cell carcinoma (p = 1); between a dotted pattern and squamous-cell carcinoma (p = 1), adenocarcinoma (p = 0.54) or small-cell carcinoma (p = 1), and between an abrupt ending capillary pattern and squamous-cell carcinoma (p = 1), adenocarcinoma (p = 1) or small-cell carcinoma (p =1). Conclusion: No relationship exists between NBI vascular patterns and the histology of lung cancer. Endobronchial lesions showing any vascular pattern on NBI needs to be adequately sampled for proper histologic and molecular studies in lung cancer patients.
Black Women’s Counter-Stories of Resilience and Within-Group Tensions in the White, Patriarchal Space of Mathematics Education
Authors: Leyva Luis A.
Published: March 2021

This article proposes and employs a framework that characterizes mathematics education as a white, patriarchal space to analyze undergraduate Black women’s narratives of experience in navigating P–16 mathematics education. The framework guided a counter-storytelling analysis that captured variation in Black women’s experiences of within-group tensions—a function of internalized racial-gendered ideologies and normalized structural inequities in mathematics education. Findings revealed variation in Black women’s resilience through coping strategies for managing such within-group tensions. This analysis advances equity-oriented efforts beyond increasing Black women’s representation and retention by challenging the racialized-gendered culture of mathematics. Implications for educational practice and research include ways to disrupt P–16 mathematics education as a white, patriarchal space and broaden within-group solidarity, including Sisterhood among Black women.
Making Meaning of Numbers from a Historic Storm
Authors: Tomayko Ming C.
Published: March 2021

A series of activities uses media coverage of a natural disaster to develop quantitative literacy.
Visualizing Complex Roots of a Quadratic Equation
Authors: Edwards Thomas , Özgün-Koca S. Asli , Chelst Kenneth
Published: March 2021

A quadratic equation was the basis for activities involving both concrete and technological representations.
GPS: From Combinations to Probability
Authors: Sun Li , Jiang Chunlian
Published: March 2021

Growing Problem Solvers offers four original, related, classroom-ready mathematical tasks, one for each grade band. Together, these tasks illustrate the trajectory of learners’ growth as problem solvers across their years of school mathematics.
The Opportunities of No-Solution Problems
Authors: Gilbertson Nicholas J.
Published: March 2021

When students encounter unusual situations or exceptions to rules, they can become frustrated and can question their understanding of particular topics. In this article, I share some practical tips.
Inquiry + Math Workshop Model = Success!
Authors: O’Connor Kathryn , Dearborne Emma , Casa Tutita M.
Published: March 2021

A version of math workshop centrally positions students to inquire mathematically.
Teaching Is a Journey: A Journey in Becoming
Authors: Wolfe Jennifer A.
Published: March 2021

This department provides a space for current and past PK–12 teachers of mathematics to connect with other teachers of mathematics through their stories that lend personal and professional support.
Presidencialismo y gobernabilidad democrática en América Latina
Authors: Fernández Toro Julio César
Published: March 2021

El artículo analiza el posible impacto del sistema de gobierno presidencial sobre la gobernabilidad democrática en América Latina, que ha sido el objeto del debate presidencialismo versus parlamentarismo desarrollado en los ambientes políticos y académicos. El debate se examina mediante una visión integral de la relación entre la variable institucional y el resultado político. Con ese propósito, el análisis se apoya en la idea de separación de poderes, un principio apodíctico del constitucionalismo democrático, que persigue con el diseño de un arreglo orgánico-funcional limitar el poder de los gobernantes para preservar la libertad de los ciudadanos. Por último, el artículo enumera las debilidades y desafíos de las presidencias latinoamericanas, y las alternativas para mejorar su capacidad de gestión y para garantizar la gobernabilidad democrática.
El diálogo entre tribunales en el marco europeo
Authors: Freixes Sanjuán Teresa
Published: March 2021

En este trabajo se aborda la interacción entre jurisdicciones situadas en distintos niveles, desde la perspectiva de poder delimitar influencias entre ellas en un sistema jurídico multinivel.
Se analizan las distintas jurisdicciones, internas, internacionales y supranacionales, así como los procedimientos a través de los cuales se efectúa ese diálogo. Especialmente se pone atención en las relaciones, bilaterales y multilaterales entre los Tribunales Constitucionales, el Tribunal Europeo de Derechos Humanos y el Tribunal de Justicia de la Unión Europea.
Y se señalan algunas de las disfunciones existentes al mismo tiempo que se proponen también algunas reformas dirigidas a reforzar y mejorar el diálogo multinivel entre las distintas jurisdicciones.
What Happened to Antimatter?
Authors:   Institute for Space-Earth Environmental Research (ISEE), Nagoya University, Tajima Hiroyasu
Published: March 2021

The Belle-II experiment is designed to explore new mechanisms of matter-antimatter asymmetry that may resolve the mystery behind the dominance of matter over anti-matter in the universe.
Compositional and functional profiling of the rhizosphere microbiomes of the invasive weed Ageratina adenophora and native plants
Authors: Xia Yun , Dong Minghua , Yu Lei , Kong Lingdong , Seviour Robert , Kong Yunhong
Published: March 2021

The rhizosphere soil microbiome (RSM) plays an important role in the nutritional metabolism of the exotic weed Ageratina adenophora. However, our understanding of the composition and metabolic activity of this microbiome is limited. We used high-throughput sequencing of bacterial 16S rRNA genes and fungal internal transcribed spacer fragments in combination with transcriptome analysis to compare the composition and metabolic features of the RSMs of A. adenophora and the native plant species Artemisia indica and Imperata cylindrica. A. indica cohabitates with the weed and I. cylindrica grows in uninvaded soil areas. We found fungi belonging to the phyla Ascomycota and Basidiomycota and bacteria belonging to the phyla Proteobacteria, Acidobacteria and Bacteroidetes were highly abundant in the RSMs of A. adenophora and both native plant species. The RSM of A. adenophora differed to varying degrees in the relative abundances of bacterial and fungal phyla and genera, and in levels of expression of functional genes from those of both the native species. The RSM of A. adenophora was more metabolically active than both of these, as indicated by marked increases in the expression levels of genes associated with cell wall, membrane, and envelope biogenesis, energy production and conversion, and the transport and metabolism of carbohydrates, amino acids, coenzymes, nucleotides, and secondary metabolites. Ascomycota and Basidiomycota contributed most significantly to these differences. The composition and metabolic activities of A. adenophora RSM differed less to the RSM of A. indica than to the RSM of I. cylindrica. Fungal communities contributed most to the metabolic genes in the RSM of A. adenophora. These included the arbuscular mycorrhizal fungi Glomeromycota. The different relative abundances in the RSMs of these three plant populations may explain why A. adenophora is more successful in colonizing soils than the two native populations.
Maniraptoran pelvic musculature highlights evolutionary patterns in theropod locomotion on the line to birds
Authors: Rhodes Matthew M. , Henderson Donald M. , Currie Philip J.
Published: March 2021

Locomotion is a fundamental aspect of palaeobiology and often investigated by comparing osteological structures and proportions. Previous studies document a stepwise accumulation of avian-like features in theropod dinosaurs that accelerates in the clade Maniraptora. However, the soft tissues that influenced the skeleton offer another perspective on locomotory adaptations. Examination of the pelvis for osteological correlates of hind limb and tail musculature allowed reconstruction of primary locomotory muscles across theropods and their closest extant relatives. Additionally, the areas of pelvic muscle origins were quantified to measure relative differences within and between taxa, to compare morphological features associated with cursoriality, and offer insight into the evolution of locomotor modules. Locomotory inferences based on myology often corroborate those based on osteology, although they occasionally conflict and indicate greater complexity than previously appreciated. Maniraptoran pelvic musculature underscores previous studies noting the multifaceted nature of cursoriality and suggests that a more punctuated step in caudal decoupling occurred at or near the base of Maniraptora.
Study of the binding of jatrophone to Escherichia coli s‐ribonucleic acid
Authors: D'Alagni Maria , De Petris Marco , Battista Marini-Bettolo Giovanni , Temussi Piero Andrea
Published: July 2002

The interaction of jatrophone with sRNA with sRNA from Escherichia coli has been investigated through UV, CD, and 1H NMR measurements. The results obtained show that the interaction with jatrophone increases the stability of the polynucleotide. It appears that the optical properties of jatrophone depend upon the jatrophone/nucleotide ratio. The observed behaviour can only be explained by the existence of different types of interaction between jatrophone and sRNA. Even for a jatrophone/nucleotide ratio as low as 0.17 the 1H NMR spectra show a multiplicity of resonances that can only be explained by the simultaneous existence of two different binding modes involving the jatrophone molecules.
Cyclic AMP, calcium and control of cell growth
Authors: Ralph R.K.
Published: July 2002

The role of cyclic AMP and calcium in the control of normal and tumour cell growth is considered in relation to the question whether cyclic AMP is a true mitogen or co‐mitogen. It is proposed that cyclic AMP normally controls the cell cycle at a point in G1 phase only by virtue of its ability to exclude calcium required by cells to progress past this point into S phase. Therefore increased influx of calcium by other routes induced by various factors can bypass the inhibitory effect of cyclic AMP and stimulate growth. In these circumstances cyclic AMP or calcium may or may not facilitate further progress into S phase according to the metabolic requirements of individual cells. The relevance to cancer cells is considered.
The binding of human milk lactoferrin to immunoglobulin A
Authors: Watanabe Toshiteru , Nagura Hiroshi , Keiichi Watanabe , Brown William R.
Published: July 2002

It was recognized that in human milk some amounts of lactoferrin (LF) were naturally bound to secretory IgA (sIgA). Since not only secretory component (SC) but also LF was released from sIgA by disulfide bond cleavage, it is conceivable that LF is naturally bound to IgA as well as SC. An in vitro binding test to LF and IgA was performed and the binding was confirmed by the use of an IgA—Sepharose 4B affinity column.
Affinity Chromatographic studies on antigen‐antibody dissociation
Authors: Fornsted Nermin
Published: July 2002

Antigen‐antibody complex
Affinity chromatography
Mild desorption
Desensitization by histamine of H2 receptor‐mediated adenylate cyclase activation in the human gastric cancer cell line HGT‐1
Authors: Prost Annie , Emami Shahin , Gespach Christian
Published: July 2002

Desensitization
Histamine H2receptor
Adenylate cyclase
Acid secretion
HGT‐1 cell
S‐phase patterns of cyclin (PCNA) antigen staining resemble topographical patterns of DNA synthesis
Authors: Madsen Peder , Celis Julio E.
Published: July 2002

The sequence of cyclin (proliferating cell nuclear antigen, PCNA), antigen staining throughout the cell cycle of African green monkey kidney cells (BS‐C‐1) has been determined by indirect immunofluorescence using PCNA autoantibodies specific for this protein. Patterns of cyclin staining observed between the beginning of S‐phase and maximum DNA synthesis are similar to those reported in human AMA cells [(1985) Proc. Natl. Acad. Sci. USA 82, 3262‐3266], while those detected thereafter are significantly different; the most striking feature being the continuous staining of the nucleoli up to or very near the S/G2 border of the cell cycle. Using [3H]thymidine autoradiography and indirect immunofluorescence of the same cells we show a remarkable correlation between cyclin antigen distribution and topographical patterns of DNA synthesis. In addition, we present evidence showing that DNase I treatment of Triton‐extracted monolayers abolishes cyclin antigen staining but does not result in a substantial release of this protein. Taken together the above observations argue for a role of cyclin in some aspect of DNA replication.
Expression of the vasopressin and oxytocin genes in human hypothalami
Authors: Mohr Evita , Hillers Mären , Ivell Richard , Haulica Ion D. , Richter Dietmar
Published: July 2002

Poly(A)+ RNA isolated from post‐mortem human hypothalami has been used to characterize the polyprotein precursors to vasopressin and oxytocin. Translation in a cell‐free system and subsequent immunoprecipitation with antibodies raised against either vasopressin or neurophysin identified a product of M
r 19000 (prepro‐vasopressin). A second less intense product of M
r 16500 was tentatively identified as prepro‐oxytocin. A cDNA library derived from the human hypothalamic poly(A)+ RNA was screened for vasopressin and oxytocin‐encoding cDNA using heterologous probes; clones encoding the two precursors were identified and found to be organized as their rat and bovine counterparts. Northern blot analysis shows that the mRNAs for the two prepro‐hormones consist of ~ 840 (AVP) and ~ 700 (OT) nucleotides.
Phosphorylation of carnitine palmitoyltransferase and activation by glucagon in isolated rat hepatocytes
Authors: Harano Y. , Kashiwagi A. , Kojima H. , Suzuki M. , Hashimoto T. , Shigeta Y.
Published: July 2002

Effects of glucagon and forskolin on the phosphorylation and changes of activity of carnitine palmitoyl‐transferase (CPT) have been studied in isolated rat hepatocytes using anti‐CPT immunoglobulin. When the activity was determined in lysed hepatocytes after glucagon or forskolin treatment, it was found to be stimulated 30–80% mainly through increased affinity for palmitoyl‐CoA. By SDS electrophoresis of the immuno‐precipitates, CPT subunit (M
r 69000) was noted to be phosphorylated 4–5‐fold with glucagon (1.2 × 10−7 M) and forskolin (0.1 mM) over control. These results indicate that hepatic ketogenesis is regulated with glucagon by phosphorylation of CPT through cAMP‐dependent protein kinase.
A wasp venom mastoparan‐induced polyphosphoinositide breakdown in rat peritoneal mast cells
Authors: Okano Yukio , Takagi Hajime , Tohmatsu Toyohiko , Nakashima Shigeru , Kuroda Yoichiro , Saito Kazuki , Nozawa Yoshinori
Published: July 2002

The phospholipid metabolism of rat peritoneal mast cells stimulated with mastoparan, a secretagogue purified from wasp venom, was investigated. Mastoparan at 20 caused a rapid secretion of histamine. Mastoparan induced a transient decrease of phosphatidylinositol 4,5‐bisphosphate on 32P labeling and generation of a water‐soluble degradation product, inositol trisphosphate on [3H]inositol labeling, suggesting the activation of phospholipase C upon stimulation.
A surface NAD‐glycohydrolase of human platelets may influence their aggregation
Authors: Del Principe D. , Menichelli A. , Casini A. , Di Giulio S. , Mancuso G. , Finazzi-Agrò A.
Published: July 2002

Human platelets may hydrolyze externally added NAD+ yielding ADPR and nicotinamide. The extent of hydrolysis is significantly higher when the platelets are stimulated. The presence of external NAD+ strongly inhibits the aggregation induced by every agonist used. It seems that adenosine or ADPR itself generated by NAD+ hydrolysis may be responsible for the inhibition of aggregation. Evidence is given that some of the NAD+ hydrolysis product is taken up by stimulated platelets.
Phosphorylation of type‐L pyruvate kinase in intact hepatocytes Localisation of the phosphorylation site in response to both glucagon and the Ca2+‐linked agonist phenylephrine
Authors: Hsu Ying Chang , Bloxham David P. , Giles Ian G.
Published: July 2002

Pyruvate kinase is one of the enzymes which can be phosphorylated by stimulation of the cell with either glucagon or Ca2+‐linked hormones. Whether these two classes of hormones phosphorylate the same site on the enzyme is unclear. Our results demonstrate that isolation of [32P]phosphorylated type‐L pyruvate kinase from glucagon‐treated hepatocytes followed by aspartyl‐prolyl cleavage yields a [32P]phosphorylated peptide of M
r 17000. This fragment is also phosphorylated in response to the Ca2+‐mediated agonist phenylephrine.
Phosphorylation of the EGF receptor from A431 epidermoid carcinoma cells by three distinct types of protein kinase C
Authors: Ido Motoharu , Sekiguchi Kazuo , Kikkawa Ushio , Nishizuka Yasutomi
Published: July 2002

Three distinct types of protein kinase C obtained from rat brain cytosol phosphorylated the EGF receptor of A431 epidermoid carcinoma cells at different rates. This receptor was phosphorylated most rapidly by type III protein kinase C, but slowly by type I enzyme. Type II enzyme showed intermediate activity. Chromatographic analysis indicated that A431 cells possessed only one of the three types found in rat brain, which apparently corresponded to type III enzyme. This type of protein kinase C, that is encoded by the α‐sequence or a closely related sequence, appeared to be expressed commonly in many tissues and organs. The result implies that type III enzyme may play roles in growth promotion.
A 40 kDa inhibitor of protein kinase C purified from bovine brain
Authors: Hucho Ferdinand , Krüger Helmut , Pribilla Iris , Oberdieck Ulrich
Published: July 2002

An inhibitor of protein kinase C has been purified to homogeneity from bovine brain cytosol by a four‐step method. It is heat stable, has an apparent molecular mass of 40 kDa and is composed of two polypeptide chains of 19 kDa.
Genotyping of human class I alcohol dehydrogenase Analysis of enzymatically amplified DNA with allele‐specific oligonucleotides
Authors: Gennari Katharina , Wermuth Bendicht , Muellener Daniel , Ehrig Torsten , von Wartburg Jean-Pierre
Published: July 2002

Large inter‐individual differences are noted in the susceptibility to alcohol‐related problems. Part of this variation may be due to the different isoenzyme patterns of the alcohol‐metabolizing enzymes and, consequently, different pharmacokinetics of alcohol degradation. We have used the polymerase chain reaction and oligonucleotide hybridization to amplify and analyze class I alcohol dehydrogenase isoenzyme‐specific genomic DNA. The method unambiguously distinguishes between different allelic variants and thus provides a new means of elucidating the alcohol dehydrogenase isoenzyme pattern of humans.
A cDNA clone encoding a 10.8 kDa photosystem I polypeptide of barley
Authors: Okkels Jens Sigurd , Jepsen Lars Bæk , Hønberg Lisbeth Skou , Lehmbeck Jan , Scheller Henrik Vibe , Brandt Peter , Høyer-Hansen Gunilla , Stummann Bjarne , Henningsen Knud W. , von Wettstein Diter , Møller Birger Lindberg
Published: July 2002

A cDNA clone encoding the barley photosystem I polypeptide which migrates with an apparent molecular mass of 16 kDa on SDS‐polyacrylamide gels has been isolated. The 634 bp sequence of this clone has been determined and contains one large open reading frame coding for a 15 457 Da precursor polypeptide. The molecular mass of the mature polypeptide is 10 821 Da. The amino acid sequence of the transit peptide indicates that the polypeptide is routed towards the stroma side of the thylakoid membrane. The hydropathy plot of the polypeptide shows no membrane‐spanning regions.
Isolation and characterization of the porcine nuclear factor I (NFI) gene
Authors: Meisterernst Michael , Rogge Lars , Donath Cornelia , Gander Irene , Lottspeich Friedrich , Mertz Ronald , Dobner Thomas , Föckler Renate , Stelzer Gertraud , Winnacker Ernst-L.
Published: July 2002

This study describes the isolation of a major portion of the gene for nuclear factor I (NFI) including its 5′‐flanking region with transcriptional start sites. We screened a porcine liver, genomic DNA library in phage EMBL3A with synthetic oligonucleotides derived from tryptic and cyanogen‐bromide peptide sequences obtained from purified NFI protein. The NFI gene is present as a single copy in porcine DNA.
Isolation and characterisation of GLP‐1 7–36 amide from rat intestine Elevated levels in diabetic rats
Authors: Kreymann B. , Yiangou Y. , Kanse S. , Williams G. , Ghatei M.A. , Bloom S.R.
Published: July 2002

Glucagon‐like peptide‐1 (GLP‐1) was purified to homogeneity by HPLC and anion‐exchange chromatography. A molecular mass of 3297.4 Da was obtained by FAB mass spectrometry which corresponded exactly to GLP‐1 7–36 NH2, providing evidence that amidation occurs at an arginine residue during the post‐translational processing of GLP‐1. The distribution of GLP‐1 7–36 NH2‐like immunoreactivity (GLP‐1 7–36 NH2 IR) was determined in the rat gastrointestinal tract. Highest concentrations were found in terminal ileum and colon. Streptozocin‐induced diabetic rats, who showed a significant increase in food intake, had a significant increase of GLP‐1 7–36 NH2 IR in the colon.
[14C]Acetate incorporation into glycerolipids from cauliflower proplastids and sycamore amyloplasts
Authors: Alban Claude , Dorne Albert-Jean , Joyard Jacques , Douce Roland
Published: July 2002

Formation of glycerolipids from [14C]acetate within proplastids from cauliflower buds and amyloplasts from sycamore cells was compared. In cauliflower proplastids, when sn‐glycerol 3‐phosphate was present, most of the radioactivity was recovered as diacylglycerol, which was converted into MGDG after addition of UDP‐galactose. The MGDG molecular species synthesized in these conditions was C18:1/C16:0 and was rapidly desaturated into C18:3/C16:0. In sycamore amyloplasts, phosphatidic acid, and not diacylglycerol, was the major compound to be synthesized in the presence of sn‐glycerol 3‐phosphate, therefore, MGDG synthesis from [14C]acetate was not possible in sycamore amyloplasts. We conclude that non‐green plastids almost behave like chloroplasts from C16:3 or C18:3 plants as far as lipid biosynthesis is concerned.
D‐Glycerate kinase deficiency as a cause of D‐glyceric aciduria
Authors: Van Schaftingen Emile
Published: July 2002

D‐Glycerate kinase was measured in human livers thanks to a new, sensitive radiochemical assay. The enzyme was extremely unstable in extracts prepared in water, but was partly stabilized in a homogenization mixture containing inorganic phosphate, D‐glycerate and EGTA. When extracted in such a stabilizing mixture, glycerate kinase activity amounted to 0.86 ± 0.21 U/g in control livers and to 0.03 U/g in the liver of a patient with D‐glyceric aciduria. In contrast, D‐glycerate dehydrogenase (glyoxylate reductase) and triokinase activities were not deficient in the liver of the same patient. It is concluded that D‐glycerate kinase deficiency is a cause of D‐glyceric aciduria.
Mechanisms of phototaxis and aerotaxis in Halobacterium halobium
Authors: Bibikov S.I. , Skulachev V.P.
Published: July 2002

DCCD and cyanide, the H+‐ATPase and respiratory chain inhibitors, increase the sensitivity of Halobacteriwn halobium to the attractant effect of light. This phenomenon requires the presence of bacteriorhodopsin and occurs at high light intensities (about 100 W/m2). Strains lacking both bacteriorhodopsin and halorhodopsin exhibit an increased sensitivity of aerotaxis. These observations are in good agreement with the hypothesis that Δg̃mH reception is one of the mechanisms responsible for phototaxis and aerotaxis in H. halobium.
Studies on the mechanism of inhibition of nuclear triiodothyronine binding by fatty acids
Authors: van der Klis F.R.M. , Wiersinga W.M. , de Vijlder J.J.M.
Published: July 2002

Studies were designed to elucidate the mechanism by which unsaturated fatty acids inhibit the binding of triiodothyronine (T3) ro rat liver nuclei. The possibility of a direct interaction between oleic acid and T3 was excluded by dialysis experiments. Oleic acid inhibits nuclear T3 binding in a strictly competitive manner. The K
i value of oleic acid was approx. 104 times greater than that of T3. The inhibitory effect of oleic acid could be reversed by bovine serum albumin.
Photoaffinity labelling of the oxytocin receptor in plasma membranes from rat mammary gland
Authors: Müller Michael , Soloff Melvyn S. , Fahrenholz Falk
Published: July 2002

Plasma membranes from rat mammary gland containing a high concentration of [3H]oxytocin binding sites (2.8 pmol/mg protein) were used for photoaffinity labelling experiments. Competitive binding experiments show that these receptors bind with high affinity the specific oxytocin agonist [Thr4, Sar7]oxytocin and the analogue of 1‐deamino‐[8‐lysine]vasopressin containing a photoreactive azidobenzoyl group (Abz) at the side chain of lysine. The tritium‐labelled (50 Ci/mol) photoreactive analogue incorporated into a membrane protein with an apparent relative molecular mass of 65000 ± 3000 Da (n = 16). The labelling of this protein was completely suppressed by an excess of oxytocin.
The microheterogeneity of rat TBG
Authors: Vranckx Roger , Savu Lia , Nunez Emmanuel A.
Published: July 2002

Isoelectric focusing (IEF) of native sera from immature or adult rats and of purified or partially purified rat serum thyroid hormone‐binding proteins, demonstrates that rat TBG is a microheterogeneous protein. Autoradiography and radioactivity scans of the IEF plates show that it consists of at least four main isoforms, with bands at pH 4.35, 4.45, 4.5 and 4.55. This pattern is remarkably similar to that reported for human TBG. This is the first demonstration of the polymorphism of this recently discovered major binding protein of the rat.
Dependence of the length of the heavy chain of chymotryptic subfragment 1 on the temperature of myosin digestion
Authors: Pliszka Barbara , Rȩdowicz Maria J. , Strzelecka-Gołaszewska Hanna
Published: July 2002

Limited digestion of filamentous myosin with chymotrypsin at 0°C in the absence of divalent cations generates two forms of subfragment 1 (S1), with heavy chains of 95 kDa and 98 kDa. The difference is at the C‐terminal end of the chain. The 98 kDa form prevails, in contrast to the preparations obtained by digestion at room temperature which consist of the shorter species and only traces of the longer one. The results support the idea of a temperature‐dependent conformational transition at the head‐rod junctional region of the myosin heavy chain.
The rat β1 ‐subunit of the GABAA receptor forms a picrotoxin‐sensitive anion channel open in the absence of GABA
Authors: Sigel Erwin , Baur Roland , Malherbe Pari , Möhler Hanns
Published: July 2002

The structural basis of GABA‐gated chloride channels in mammalian brain is presently explored by the functonal expression of cDNAs coding for the α, β or γ‐subunits of the receptor and their isoforms. In this context, we expressed the cloned cDNA coding for the rat β1‐subunit of the GABAA receptor in the Xenopus oocyte. Surprisingly, efficient expression of a functional ion channel was found. The channel was anion‐selective, and able to open in the absence of GABA. Since this channel could be shut by the GABA‐channel blocker picrotoxin, we conclude that the β1 ‐subunit of the GABAA receptor is sufficient to form binding sites for picrotoxin.
Augmented production of platelet‐activating factor in human polymorphonuclear leukocytes by ketone bodies
Authors: Sugiura Takayuki , Ojima-Uchiyama Ayako , Masuzawa Yasuo , Waku Keizo
Published: July 2002

The production of platelet‐activating factor (PAF) in A23187‐stimulated human polymorphonuclear leukocytes was markedly increased in the presence of 5 mM acetoacetate and β‐hydroxybutyrate. Such an augmentation was observed even at 500 μM but not at 50 μm. The augmented production of PAF by acetoacetate was also observed in the presence of autologous serum and was most prominent in the case of opsonized zymosan‐stimulation rather than A23187‐stimulation. These observations suggest that increased levels of acetoacetate and μ‐hydroxybutyrate in blood may lead to the augmented production of PAF, which would amplify the various PAF‐mediated biological reactions.
Evidence for a single butyrylcholinesterase gene in individuals carrying the C5 plasma cholinesterase variant (CHE2)
Authors: Masson Patrick , Chatonnet Arnaud , Lockridge Oksana
Published: July 2002

DNA of 3 unrelated individuals carrying the human plasma butyrylcholinesterase C5 variant (CHE2) was isolated from white blood cells. Southern blot patterns of DNA restriction fragments probed with each of the 4 butyrylcholinesterase exons provided evidence that the production of C5 is not directed by a second butyrylcholinesterase gene. This finding supports the suggestion that the C5 variant is a hybrid enzyme resulting from the association of butyrylcholinesterase subunits with a non‐cholinesterase protein.
Acetyl‐L‐carnitine increases cytochrome oxidase subunit I mRNA content in hypothyroid rat liver
Authors: Gadaleta M.N. , Petruzzella V. , Fracasso F. , Fernandez-Silva P. , Cantatore P.
Published: July 2002

The effect of acetyl‐L‐carnitine on the quantity of the messenger RNA for the subunit I of cytoehrome oxidase in the liver mitochondria of hypothyroid rat was measured by Northern blot and solution hybridization. Three hours after pre‐treatment of hypothyroid rat with acetyl‐L‐carnitine, the level of the transcript increased strongly. This effect was also obtained when acetyl‐L‐carnitine was administered to T3 pre‐treated hypothyroid rats. These results add further evidence to the suggestion that acetyl‐L‐camitine is able to stimulate mitochondrial transcription under altered metabolic conditions.
Microheterogeneity and interspecific variability of the nuclear sperm proteins from Mytilus
Authors: Mogensen Catherine , Carlos Steve , Ausio Juan
Published: July 2002

We have used acetic acid‐urea‐triton (AUT) gel electrophoresis and ionic exchange chromatography in order to analyze the interspecific, variability and microheterogeneity pattern of the protamine‐like (PL) protiens of the sperm or 4 different species or the bivalve molluse, Mytilus. We have found that based upon these 2 criteria, it is possible to unambiguously distinguish each species from the rest. We have thus been able to corroborate the identity or M. irossulus, We have also analyzed the amino acid composition of some of the PL components for each different species, In the case of the PL‐11* fraction, we have analyzed the composition of its major protein subcomponents.
15N NMR studies of the conformation of E. coli dihydrofolate reductase in complex with folate or methotrexate
Authors: Huang Fu-Yung , Yang Qing-Xian , Huang Tai-huang
Published: July 2002

We have employed 15N NMR to characterize the conformations of Escherichia coli dihydrofolate reductase (ECDHFR) in complex with [5‐15N]folate or [5‐15N]methotrexate (MTX). Two 15N resonances were observed for DHFR/MTX binary complex. The relative population of these two conformations is pH dependent. Addition of NADP+ or NADPH results in the disappearance of the low field resonance. In contrast, only one conformation was observed for both the DHFR/folate and DHFR/folate/NADP+ complexes. However, the 15N chemical shift of [5‐15N]folate in the binary DHFR/folate complex is 7.28 ppm upfield from that of the ternary complex, suggesting the possible loss of a hydrogen bonding to N5 of folate in the ternary complex.
Chromaffin granule H+‐ATPase has F1‐like structure
Authors: Moriyama Yoshinori , Yamamoto Akitsugu , Tashiro Yutaka , Futai Masamitsu
Published: July 2002

Isolated H+‐ATPase from chromaffin granules was reconstituted into liposomes and the resultant proteoliposomes were further purified by Ficoll density gradient centrifugation. Studies by electron microscopy showed that proteoliposomes had particle structures (average diameter, about 10 nm) on their outer surface. These particles could be removed from the proteoliposomes by cold treatment. Immuno‐electron microscopy showed that these particles were recognized by antibodies against the hydrophilic sector of the enzyme. These results indicate that the H+‐ATPase has a peripheral membrane structure similar to that of F1‐ATPase.
Efficient in vitro folding of the three‐disulfide derivatives of hen lysozyme in the presence of glycerol
Authors: Sawano Hiroshi , Koumoto Yasuko , Ohta Katsuyuki , Sasaki Yukio , Segawa Shin-ichi , Tachibana Hideki
Published: July 2002

Four derivatives of hen lysozyme, each lacking one native disulfide bond of the four in authentic lysozyme, were produced in Escherichia coli by expressing synthetic mutant genes. In the reoxidation reaction of the reduced derivatives purified from inclusion bodies, the addition of glycerol significantly enhanced the efficiency of folding and ‘correct’ disulfide bond formation. This enabled simple chromatographical purification of refolded materials. Purified 3SS‐derivatives all showed lytic activities and secondary structures comparable to authentic lysozyme, which directly showed that none of the four native disulfide bonds is a prerequisite for ‘correct’ in vitro folding.
Cell density‐dependent expression of heparin‐binding growth‐associated molecule (HB‐GAM, p18) and its down‐regulation by fibroblast growth factors
Authors: Merenmies Jussi
Published: July 2002

Heparin‐binding growth‐associated molecule (HB‐GAM) is a developmentally regulated protein that is intensely expressed during the rapid postnatal growth phase of rat brain. The expression of HB‐GAM studied in 12 cell lines was restricted to C6 rat glioma cell line and BALB/c 3T3 cells. In BALB/c 3T3 cells the expression of HB‐GAM enhanced in confluent and quiescent cell cultures. When the confluent cultures were treated with bFGF the expression of HB‐GAM mRNA was strongly reduced and the protein disappeared rapidly from proliferating cells. The data presented suggest involvement of HB‐GAM in cell differentiation phenomena rather than in cell proliferation.
Cloning, sequence analysis and expression in Escherichia coli of the cDNA encoding a precursor of peanut agglutinin
Authors: Rodriguez-Arango Esperanza , Arango Rafael , Adar Rivka , Galili Gad , Sharon Nathan
Published: July 2002

The cDNA coding for pre‐peanut agglutinin (PNA) was isolated from a bacterial expression library. It codes for a polypeptide of 273 amino acids composed of a hydrophobic signal peptide of 23 amino acids and a mature protein of 250 amino acids. The sequence of the latter is identical to that of native PNA, determined very recently by conventional methods, except that it contains 14 additional amino acids at the C‐terminus. Bacterial cells harboring a plasmid with the prePNA—cDNA, produced two PNA cross‐reacting proteins; one migrated on SDS‐PAGE identically with the native lectin (apparent mol. wt. 31 kDa); the other, at 35 kDa, was a β‐galactosidase pre‐PNA fusion protein. The former protein possessed an N‐terminal sequence identical to that of the mature, native PNA, suggesting that it was processed from the 35 kDa prePNA precursor. Only the 31 kDa protein was exported into the bacterial periplasmic space, and had the ability to bind to galactose—Sepharose. The isolated processed protein had the same hemagglutinating activity as the native lectin, when assayed with sialidase‐treated human erythrocytes. Like the native lectin, it did not agglutinate the untreated cells, was not inhibited by N‐acetylgalactosamine, and was inhibited by GAlβl→3GalNAc 30‐times more strongly than by galactose.
Prostaglandin H synthase
Authors: Mevkh Alevtina T. , Miroshnikov Konstantin A. , Igumnova Natalia D. , Varfolomeev Sergey D.
Published: July 2002

Prostaglandin H synthase (PGHS) as apo‐PGHS, holo‐PGHS, and holo‐PGHS, inactivated in the course of catalysis was studied using chemical modification with diethyl pyrocarbonate (DEPC). The exhausted reaction with DEPC corresponded to the modification of 7 histidine residues in apo‐PGHS and 4 in holo‐PGHS. All 18 histidine residues became accessible for modification with DEPC in the enzyme, inactivated in the course of catalysis. The velocities of tryptic cleavage of all the three forms into two fragments were fairly different but independent of modification. Based on the results we hypothesize fast and dramatic changes in the protein structure in the course of the substrate conversion.
Catalytic and activating protons follow different pathways in the H+‐ATPase of potato tuber mitochondria
Authors: Valerio Marie , Haraux Francis
Published: July 2002

The effect of some F0F1 inhibitors on the activation of the H+‐ATPase by the electrochemical proton gradient was investigated in mitochondria extracted from potato tubers. Transient activated state of the ATPase was revealed by addition of ATP and of the detergent lauryldimethylamine oxide (LDAO) to energized mitochondria. Venturicidin, tri‐n‐butyltin and aurovertin at high concentrations did not affect the process of Δ/̃gmH+‐activation, whereas oligomycin fully blocked it. The results support the idea of separate pathways or binding sites for catalytic and activating protons.
Conformational study of three endothelin antagonists with 1H NMR at low temperature and molecular dynamics
Authors: Verheyden Patricia , Van Assche Ivo , Brichard Marie-Hélène , Demaude Thierry , Paye Ingrid , Scarso Alain , Van Binst Georges
Published: July 2002

The conformations of three endothelin antagonists, a cyclic pentapeptide, a linear tripeptide and a linear hexapeptide, are compared by 1H NMR and molecular dynamics. The three analogues have a Leu and a dTrp side chain which are oriented parallel, and an acidic group next to the dTrp residue.
Oncogenically activated or ligand‐stimulated neu kinase stimulates neurite outgrowth in PC12 cells
Authors: Gamett Daniel C. , Cerione Richard A.
Published: July 2002

Retroviral vectors pDOL/NeuN and pDOL/NeuT were used to express normal and transforming rat neu cDNAs in PC12 cells. DOL/ NeuT‐infected cells exhibited a high frequency of spontaneous neurite outgrowth while DOL/NeuN‐infected cells showed neurite outgrowth in the presence of heregulin, a putative ligand for the neu receptor tyrosine kinase. In both cases, neurite outgrowth was preceded by phosphorylation of p185neu and several other cellular proteins. Thus the neu tyrosine kinase can elicit morphological and biochemical changes resembling, but distinct from, those stimulated by NGF, and heregulin stimulates neu to elicit these effects in PC12 cells.