bluuebunny/crossref_metadata_2025 huggingface dataset:
Erythrocytes as Biomarkers of Virus and Bacteria in View of Metal Ion Homeostasis
Authors: Johansson Erland , B. Falk Anders
Published: May 2021

The erythrocyte contributes to the immune system in several ways. It sequesters interferons, interleukins or chemokines and by binding nucleic acid. It binds virus and bacteria and may deliver bacteria to macrophages for phagocytosis. It may also kill bacteria directly with oxygen. For proper function of the erythrocyte, homeostasis of reactive oxygen species, selenium, metal ions and trace elements is important. Erythrocytes display morphological and metabolic changes in diseases like sepsis, and in several genetic diseases. Patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), giving rise to the coronavirus disease 2019 (Covid-19), show many erythrocyte changes as compared to healthy controls. The erythrocyte responds to hemolysins by purinergic signaling leading to hemolysis or phosphatidylserine exposure on the plasma membrane. Phosphatidylserine marks erythrocytes for clearance by spleen macrophages. Regulated erythrocyte cell death, also called eryptosis, can be induced by oxidative stress, pathogen infection, and certain diseases like sepsis. Erythrocytes may, in the future, contribute more to diagnosis based on research and diagnostic technological development.
Seismic Response Characteristics of RCC Dams Considering Fluid-Structure Interaction of Dam-Reservoir System
Authors: Ghaedi Khaled , Hejazi Farzad , Gordan Meisam , Javanmardi Ahad , Khatibi Hamed , Joharchi Ali
Published: May 2021

In analysis of different types of dams, i.e. arch, gravity, rockfill and Roller Compacted Concrete (RCC) dams, the effect of hydrodynamic water pressure as an effective factor must seriously be taken into consideration. In present study, the hydrodynamic effect is precisely deliberated in RCC dams and compared to hydrostatic pressure effect. For this purpose, Kinta RCC dam in Malaysia is selected and 2D finite element (FE) model of the dam is performed. The Lagrangian approach is used to solve the dam-reservoir interaction, fluid–structure interaction (FSI), and in order to evaluate the crack pattern, Concrete Damaged Plasticity (CDP) model is implemented. Comparisons show that hydrodynamic pressure significantly changes the dam behaviour under seismic excitations. Moreover, the hydrodynamic effect modifies the deformation shape of the dam during the ground motions, however, it increases the magnitudes of the developed stresses causing more extensive tension crack damages mostly in the heel and upstream zones of the dam.
Lipid Peroxidation as a Link between Unhealthy Diets and the Metabolic Syndrome
Authors: N. Onyango Arnold
Published: May 2021

Unhealthy diets, such as those high in saturated fat and sugar accelerate the development of non-communicable diseases. The metabolic syndrome is a conglomeration of disorders such as abdominal obesity, hypertension, impaired glucose regulation and dyslipidemia, which increases the risk for diabetes and cardiovascular disease. The prevalence of the metabolic syndrome is increasing globally, and dietary interventions may help to reverse this trend. A good understanding of its pathophysiological mechanisms is needed for the proper design of such interventions. This chapter discusses how lipid peroxidation is associated with the development of this syndrome, mainly through the formation of bioactive aldehydes, such as 4-hydroxy-2-nonenal, malondialdehyde, acrolein and glyoxal, which modify biomolecules to induce cellular dysfunction, including the enhancement of oxidative stress and inflammatory signaling. It gives a current understanding of the mechanisms of formation of these aldehydes and how dietary components such as saturated fatty acids promote oxidative stress, leading to lipid oxidation. It also outlines mechanisms, apart from free radical scavenging and singlet oxygen quenching, by which various dietary constituents prevent oxidative stress and lipid oxidation in vivo.
The Relationship Between IgA Vasculitis and Antioxidant Activity In Children
Authors: TEMEL Hayrettin
Published: May 2021

Objective: Immunoglobulin A vasculitis (IgAV) is the most common systemic vasculitis seen in children. The aim of this study is to investigate the relationship between malondialdehyde-induced oxidative stress, antioxidant system and organ involvement in IgAV patients.
Method: 32 patients and 28 healthy children were included in the study. Serum malondialdehyde, reduced glutathione, vitamin E, vitamin C, retinol, and beta-carotene levels were measured in patients (separately in both the active and remission phases) and healthy children.
Results: MDA levels were significantly higher in patients with active phase while reduced glutathione and vitamin C levels were markedly lower in both the active and the remission phases. Retinol and beta-carotene levels were lower in the active phase. It was found that retinol levels were significantly lower in patients with gastrointestinal system involvement compared to those without. Vitamin C levels were significantly lower in those with kidney involvement compared to those without. Also, a negative correlation was observed between retinol levels and the number of organs involved.
Conclusion: We consider that especially vitamin C and vitamin A may be used in the treatment of IgAV. However, whether the derangements of the oxidant/antioxidant balance in the direction of increased oxidative stress are consequences or causes of the events occurring in the active phase of IgAV are open to further investigation.
Vortioxetine for generalised anxiety disorder in adults
Authors: Meza Nicolás , Leyton Fanny
Published: May 2021

INTRODUCTION The currently accepted psychopharmacological treatment for generalised anxiety disorder in adults is associated with several adverse effects which threaten its acceptability. In this line, vortioxetine has been proposed as an alternative with less adverse effects in the treatment of this pathology. METHODS We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS We identified seven systematic reviews including five primary studies, all corresponding to randomized trials evaluating the effectiveness of vortioxetine in adult patients with generalized anxiety disorder without current treatment. We conclude that there is uncertainty whether vortioxetine increases the response to treatment or improves anxious symptoms, because the certainty of the existing evidence has been assessed as very low. Furthermore, vortioxetine may increase nausea (low certainty evidence).
Supporting Diverse Learners: Teacher Collaboration in an Inclusive Classroom
Authors: Bray Wendy S.
Published: May 2021

A look at the challenges inherent in a pilot study looking at the impact of mathematics reform on students with exceptionalities. This article explores some of the ways these second-grade teachers support the mathematics learning of the diverse group of students in their class and how readers can support a diverse student population in their own classrooms.
Problem Solvers: Measuring Up
Authors: Britton Barbara , Tayeh Carla
Published: May 2021

The goal of the “Problem Solvers” department is to foster improved communication among teachers by posing one problem each month for K—6 teachers to try with their students. Every teacher can become an author: pose the problem, reflect on your students' work, analyze the classroom dialogue, and submit the resulting insights to this department. Every teacher can help us all better understand children's capabilities and thinking about mathematics with their contributions to the journal. Remember that even student misconceptions provide valuable information.
Calculators for Students with Special Needs
Authors: Thompson Tony , Sproule Stephen
Published: May 2021

A framework to aid instructional decision-making regarding classroom calculator use. The guide focuses on both teacher goals and the students' needs and abilities. The reader is challenged to rethink the possible role that calculators can serve for all students, in particular, as a classroom accommodation for students with special needs.
Teaching without Telling: Computational Fluency and Understanding through Invention
Authors: Heuser Daniel
Published: May 2021

First– and second–grade students work in a simulated candy factory to learn to add and subtract fluently and with understanding. A goal of this project was to encourage children's inventions of numerical computational strategies. The author describes ways for classroom teachers to achieve this goal and others through the successful implementation of this project.
Getting Started with Open-Ended Assessment
Authors: Leatham Keith R. , Lawrence Kathy , Mewborn Denise S.
Published: May 2021

This article discusses the nature of open-ended assessment items, their benefit to student learning, and how one teacher began using such items in her fourth-grade classroom. Also included are suggestions for getting started using open-ended assessment items in the elementary classroom.
Math by the Month: Natural Wonders
Authors: Marsh Julia , Loesing Jenine , Soucie Marilyn
Published: May 2021

The “Math by the Month” activities are designed to engage students to think like mathematicians. Students may work on the activities individually or in small groups, or they may be used with the whole class as problems of the week. No solutions are suggested so that students will look to themselves for mathematical justification, thereby developing the confidence to validate their work.
Are dimensions of gender inequality uniformly associated with human values?
Authors: Stefani Serena , Prati Gabriele
Published: May 2021

A previous work of Schwartz and Rubel-Lifschitz (2009, https://doi.org/10.1037/a0015546) highlighted the association between human values and gender equality. However, gender equality is not a monolith. Indeed, it is a multidimensional phenomenon. We started from this multidimensionality to understand how the relative importance of human values varies through the different dimensions of Gender Equality Index (GEI)—namely work, money, knowledge, time, power, and health. We have designed a cross-national study based on secondary data analysis from international databases (i.e., European Social Survey [ESS] and GEI). Through the Bayesian correlational analysis of 18 European countries, findings revealed that 1) universalism, benevolence and self-direction are strongly and positively correlated to gender equality; 2) security, power and achievement are strongly and negatively correlated to equality while 3) conformity, tradition, stimulation, and hedonism have weak/non-significant correlation coefficients with gender equality. Relevance to cultural values and ideologies that support social equality are discussed. Furthermore, we find that some values are related to certain specific gender equality dimensions. Our results provide a more fine-grained analysis compared to previous findings, by outlining a more complex scenario.
From a clinical case to a review of literature: Struma ovarii associated with ascites and high serum CA125
Authors: Minciuna Corina-Elena , Tudor Stefan , Herlea Vlad , Vasilescu Catalin
Published: May 2021

Struma ovarii is a rare dermoid tumor of the ovary (1% of all ovarian tumors and 2,7% of ovarian teratomas), with more than 50% of the overall tissue being thyroid. Approximately one third of the cases present ascites. Pseudo-Meigs syndrome has been reported in fewer than 10 cases and 5-8% present thyroid hyperfunction. However, only 26 cases
reported the association of ascites or pseudoMeigs’ syndrome, elevated cancer antigen 125 and benign struma ovarii in the literature. The authors submit a case of benign struma ovarii that presented as a pelvic mass with ascites and highly elevated CA 125 serum levels and an extensive literature survey on this topic.
Hepatic mucinous cystadenoma of the left liver in a pacient with right hepatectomy for hepatic hydatid cyst
Authors: Ciuntu Bogdan Mihnea
Published: May 2021

Cystadenoma of the liver is a rare benign neoplasm with a intrahepatic ingrowth, with a representation of only
5 % of the hepatic cystic lesions The literature describes the malignant degeneration in average of 10 % of
cases. Material and met|hod: We present the case of a 48 year old patient with personal surgical history of
right hepatectomy for hepatic hidatic cyst, with a tumoral mass in the epigastric region accompanied by pain
that appears spontaneous and by palpation . The abdominal-pelvic computer tomography performed carried
out raised the suspicion of hepatic hidatid cyst. During surgery we identified the presence of a serous
hepaticcyst inthe segment IV of the liver. The result of the anatomical pathological examinationhas reviled a
cystic mucinous neoplasm with low-grade dysplasia (cystadenoma of the liver). Discussion The biochemical
tests are in most cases normal, the alkaline phosphatase and Bilirubin can be modified in the case in which
the mass creates compression on the biliary ducts. As regards the tumor markers CA 19-9, they can have the
value slightly raised; The surgical intervention is the treatment proposed in the majority of cases, within the
oncological limits of resection. In this case, the patient’s surgical antecedents (right hepatectomy) have made
the resection in oncological limits impossible, the only option being the oncological dispensarisation and
periodic biochemical and imaging monitoring . Results The clinical presentations of the hidatid hepatic cyst
and hepatic cystadenoma may be similar as well as the imaging scans, such as ultrasonography, computer
tomography, magnetic resonance, imaging may not establish a diagnosis of certainty.
On a New Analytic Theory of the Moon's Motion III: Further Corrections
Authors: Calvet Ramon Gonzalez
Published: May 2021

Further corrections to the analytic theory of the lunar motion deduced from the first-order approximation to the Lagrange equations of the Sun-Earth-Moon system expressed in relative coordinates and accelerations are evaluated. Those terms arising from the second-order approximation, the planetary perturbations and Earth's spheroidal shape are calculated and bounded, all of them being very small. Finally, Earth's gravitational parameter is calculated from gravity data finding a value slightly higher than that provided by Jet Propulsion Laboratory.
Development of an inexpensive matrix-assisted laser desorption—time of flight mass spectrometry method for the identification of endophytes and rhizobacteria cultured from the microbiome associated with maize
Authors: LaMontagne Michael G. , Tran Phi L. , Benavidez Alexander , Morano Lisa D.
Published: May 2021

Many endophytes and rhizobacteria associated with plants support the growth and health of their hosts. The vast majority of these potentially beneficial bacteria have yet to be characterized, in part because of the cost of identifying bacterial isolates. Matrix-assisted laser desorption-time of flight (MALDI-TOF) has enabled culturomic studies of host-associated microbiomes but analysis of mass spectra generated from plant-associated bacteria requires optimization. In this study, we aligned mass spectra generated from endophytes and rhizobacteria isolated from heritage and sweet varieties ofZea mays. Multiple iterations of alignment attempts identified a set of parameters that sorted 114 isolates into 60 coherent MALDI-TOF taxonomic units (MTUs). These MTUs corresponded to strains with practically identical (>99%) 16S rRNA gene sequences. Mass spectra were used to train a machine learning algorithm that classified 100% of the isolates into 60 MTUs. These MTUs provided >70% coverage of aerobic, heterotrophic bacteria readily cultured with nutrient rich media from the maize microbiome and allowed prediction of the total diversity recoverable with that particular cultivation method.Acidovoraxsp.,Pseudomonassp. andCellulosimicrobiumsp. dominated the library generated from the rhizoplane. Relative to the sweet variety, the heritage variety c ontained a high number of MTUs. The ability to detect these differences in libraries, suggests a rapid and inexpensive method of describing the diversity of bacteria cultured from the endosphere and rhizosphere of maize.
Compromiso en Twitter: métodos analíticos para #Somos70porcento
Authors:   Universidade Federal de Santa Catarina, Paulino Rita ,   Universidade Federal de Santa Catarina
Published: May 2021

Considerando que las redes sociales se han convertido en escenario de debates y movimientos políticos en la historia reciente, y que estos datos pueden servir de base para la promoción de investigaciones sobre engagement y polarización, este artículo presenta tres métodos de análisis de redes sociales: Análisis de red; Análisis textual y Análisis de emoji. El objetivo es demostrar la aplicación de estas metodologías y enseñar brevemente cómo aplicar cada herramienta para que otros investigadores puedan aprovechar estos recursos. Aprovechando el escenario de la pandemia de 2020, esta investigación utiliza 45.121 tuits como muestra con la etiqueta #Somos70porcento, recopilado con el software Netlytic. Por último, se observa que cada método puede revelar comportamientos, perfiles y sentimientos de la red. #Somos70porcento representa una voz de revuelta en un momento de crisis de salud como los vividos en 2020 y refuerza las Redes Sociales como espacio democrático y de debate.
Big y Small data: ver y discutir series de televisión en streaming
Authors:   Universidad de Alcalá, Martínez Rut , Lacasa Pilar ,   Universidad de Alcalá, Del Castillo Héctor ,   Universidad de Alcalá
Published: May 2021

Este trabajo analiza los procesos de comunicación en medios en línea sobre cuatro series de televisión, todas ellas en Netflix (La Casa de Papel, Peaky Blinders, Elite y Educación Sexual). Nos interesa cómo estas series de streaming son reconstruidas por audiencias específicas en las redes sociales. Nos fijamos en las conversaciones organizadas alrededor de estas series por parte de comunidades digitales de fans en Twitter, Facebook, YouTube, y otros contextos digitales (por ejemplo, las revistas en línea). Se generó un total de 408.536 menciones y 189.040 usuarios como corpus de datos. El proceso de análisis requiere de una canalización del flujo de datos, definiendo un sistema coherente de temas y categorías. El artículo muestra los elementos presentes en las comunidades de fans para reconstruir las historias, por ejemplo, mencionando a actores o a personajes. Aparecen dimensiones muy similares tanto en relación con las historias como con la forma en la que se construyen a partir de una situación pandémica.
Predictores psicosociales de la exposición y difusión de noticias falsas en Costa Rica
Authors:   Universidad de Costa Rica, Brenes Peralta Carlos , Pérez Sánchez Rolando ,   Universidad de Costa Rica, Siles González Ignacio ,   Universidad de Costa Rica
Published: May 2021

Este estudio investiga los predictores psicosociales y sociodemográficos de la exposición a noticias falsas entre adultos costarricenses, así como su autopercepción de la capacidad de reconocerlas y de difundirlas. Se condujo una encuesta representativa por muestreo estratificado aleatorio aplicada a 805 usuarios de teléfonos celulares en 2019, con un 67% de mujeres y una edad promedio de 38,83 (DT=15,75). En el ámbito actitudinal, los resultados muestran una asociación positiva entre el autoritarismo de derecha y la difusión intencional de noticias falsas en redes sociales. En el ámbito motivacional, se encontraron asociaciones positivas entre una motivación defensiva y la exposición a noticias falsas en medios de comunicación y vía WhatsApp, así como asociaciones entre motivaciones defensivas y de precisión con la autopercepción de la capacidad de reconocer noticias falsas. Las mujeres, las personas con mayor nivel educativo y las más jóvenes se exponen más a noticias falsas, mientras que los hombres y las personas con mayor educación dicen ser más capaces de identificar noticias falsas.
Desafíos éticos en el estudio de comunidades digitales: una propuesta basada en un caso empírico
Authors:   Pontificia Universidad Católica de Chile, López Escarcena Ignacio
Published: May 2021

Este artículo busca aplicar a un caso empírico algunas de las principales preocupaciones éticas para investigadores con respecto al estudio de comunidades en la comunicación digital. En ese sentido, una consideración esencial se relaciona con las acciones que pueden resguardar a los participantes que comentan públicamente en línea de sufrir daño cuando se utilizan los contenidos generados por los usuarios para estudios académicos. Con esto en mente, se toma como caso empírico un estudio sobre tres plataformas en línea, en las que sus integrantes discuten acerca de cine. Por medio de una metodología que plantea aplicar un disfraz leve a la hora de divulgar los resultados, este artículo busca resaltar la importancia de modificar los nombres de los usuarios, más allá de las características de la plataforma en cuestión. Si bien es necesario considerar que la comunicación digital supone evaluar cada investigación desde un punto de vista ético, alterar los datos de los participantes ayuda a resguardar a quienes compartieron contenido sin tener presente que este material pudiera ser analizado en un estudio académico.
Memes sobre las tecnologías en las escuelas. Un estudio de las producciones estudiantiles
Authors:   Instituto de Investigaciones en Ciencias de la Educación, Universidad de Buenos Aires, Carp Dafne , Saez Virginia ,   CONICET / Instituto de Investigaciones en Ciencias de la Educación, Universidad de Buenos Aires
Published: May 2021

Los memes constituyen objetos culturales que, por su potencia y proyección, generan modos novedosos de construcción del conocimiento. Como objetivo general nos proponemos caracterizar y analizar las producciones del concurso de fotografías y memes Los Medios en las Escuelas 2019 en el contexto argentino. Los participantes, de entre 12 a 18 años, fueron motivados a expresar su reflexión sobre los medios y tecnologías en el aula mediante memes. A partir del análisis cualitativo de una muestra de 32 piezas, estos últimos se evidencian como recursos simbólicos significativos para los adolescentes, por su capacidad de condensación de sentidos identitarios, en su relación con las tecnologías y su diferenciación con los adultos.
Neutrophil Gelatinase-Associated Lipocalin (NGAL): An Early Dual Biomarker in Diagnosis of Ascitic Fluid Infection and Acute Kidney Injury in Liver Cirrhosis in a Tertiary Centre, Egypt
Authors: Nassar Dalia Kamal , Elkenawy Mohammed Fouad , El-Naggar Mohammed Mahmoud , Khalil El-Sayed Abdul-Maksoud , Barakat Ghada Ibrahim
Published: May 2021

Background: This study aimed to evaluate the ascitic Neutrophil gelatinase-associated lipocalin (NGAL) as a diagnostic biomarker for bacterial translocation or bactDNA translocation in ascites of cirrhotic patients and to evaluate the urinary NGAL for identifying renal dysfunction in patients with liver cirrhosis.

Methods: This study included 44 patients with ascites.  Study participants were divided into two groups. Group (1) had 22 patients with neutrocytic ascites and/or positive ascitic fluid (AF) culture while group (2) included 22 patients with culture negative non neutrocytic ascites (CNNNA), recruited as controls. AF and urine samples were collected from all studied participants. ELISA kit was used for measurement of NGAL levels in AF and urine. DNA extraction and PCR were done.

Results: Values of NGAL in ascitic fluid were statistically significantly higher in bactDNA positive group. At cutoff 143.9 ng/ml, ascites NGAL had 86.4% sensitivity, 45.5% specificity, 61.3% positive predictive value (PPV) and 76.9% negative predictive value (NPV). When comparing ascites NGAL between bactDNA positive and negative group, NGAL has a sensitivity of 86.2% and a specificity of 46.7%, PPV of 75.8%, NPV of 63.6%. As for urine NGAL, patients with AKI had statistically significant higher levels of NGAL. Urine NGAL achieved sensitivity of 77.3%, specificity of 50%, PPV of 60.7%, NPV of 68.75%.

Conclusion: Early and accurate diagnosis of BT or bactDNA translocation  can be aided by utilizing NGAL especially in ruling out infection in those reported to have negative culture results, besides, it can help in early detection of complication of cirrhosis and infection especially AKI helping in the improving the prognosis of cirrhotic patients. It is an advantage that a single marker can detect both infection and kidney injury.
Performance Assessment of Ship Hull Metal in Seawater Media
Authors: Idiapho Clement A. , Awwal Sani I. , Emmaunel Udosoh N.
Published: May 2021

This research was undertaken to determine the effects of corrosion on material performance using mild steel and Aluminum as selected material in seawater media. The result from the experiment showed higher corrosion rate in uncoated mild steel coupon as higher corrosion rate ranges from 0.0494 mmpy, 0.0565 mmpy, and 0.0656 mmpy was evident, while a reduction in corrosion rate from 0.0369mmpy, 0.0432 mmpy and 0.0452mmpy was observed in the fourth week, fifth week and sixth week. Corrosion rate for coated mild steel ranges from 0.0396 mmpy in the first week and reduces to 0.0333 mmpy and continually reduces to 0.0206 mmpy in the sixth week. From the hardness testing device using MITECH 320, uncoated Mild steel metal specimen gave an average Brinell hardness reading of 112 before immersion and 105 after immersion to seawater. Also, the tensile strength of the uncoated mild steel specimen deteriorated from 414 Mpa before immersion to 403Mpa after immersion to seawater media. Also, uncoated Aluminum specimen gave a brinell average reading of 163 before immersion and 152 after immersion to the seawater media. Likewise, the tensile strength result of the aluminum specimen gave 776M pa before immersion and 744 Mpa after immersion to the seawater media. The overall result from weight loss technique and metal hardness using MITECH 320 showed aluminum metal is more resistive to corrosion attack.
Variation quantitative de la fraction d'histone specifique aux erythrocytes, au cours du developpement du poulet
Authors: Mazen A. , Champagne M.
Published: July 2002

Aminoacid analysis and disc electrophorosis on extracts “F1” demonstrate that specific histone fraction F1‐cF3 occurs in smaller percentage in the early stages of chicken development; it increases from 6% (by weight of the total DNA) in 3 days old chicken to 16% in 21 days old chicken. But the percentage of F1‐cF1 fraction (8% by weight of total DNA) remains constant in the same conditions.
Purification of soluble murine transplantation antigens by isoelectric focusing
Authors: Jolles P. , Schoentgen F. , Halle-Pannenko O.
Published: July 2002

Hydrosoluble transplantation antigens were prepared from membranes and microsomes of C3H mice (BP8 tumoral cells) and purified by isoelectric focusing. A biologically active fraction which seems homogenous by acrylamide gel electrophoresis was characterized: it specifically inhibits anti C3H hemagglutinin antibodies and provokes a highly significant prolongation of skin graft.
Mitochondrial peptide chain elongation factors from Neurospora crassa
Authors: Grandi Maria , Küntzel Hans
Published: July 2002

Two complementary peptide chain elongation factors (G and T) have been isolated from a mitochondrial 100,000 g supernatant. Both factors are specific for 70 S ribosomes and can be crossed with T and G factors from E. coli.
Isolation of glucagon‐37 (bioactive enteroglucagon/oxyntomodulin) from porcine jejuno‐ileum
Authors: Bataille D. , Tatemoto K. , Gespach C. , Jörnvall H. , Rosselin G. , Mutt V.
Published: July 2002

A peptide isolated from porcine gut according to its glucagon‐like activity in liver (bioactive enteroglucagon) has been characterized immunologically, biologically and chemically: its potency relative to pancreatic glucagon in interacting with an antiglucagon antibody, hepatic glucagon‐binding sites and hepatic adenylate cyclase was ∼100%, 20% and 10%, respectively. In contrast, it is ∼20‐times more potent than glucagon in oxyntic glands, justifying the term ‘oxyntomodulin’. Chemically, it consists in the 29 amino acid‐peptide glucagon elongated at its C‐terminal end by the octapeptide Lys—Arg—Asn—Lys—Asn—Asn—Ile &—Ala; accordingly, it is called ‘glucagon‐37’
A biotin‐dependent sodium pump: glutaconyl‐CoA decarboxylase from Acidaminococcus fermentans
Authors: Buckel Wolfgang , Semmler Roswitha
Published: July 2002

The decarboxylation of glutaconyl‐CoA to crotonyl‐CoA in the anaerobic bacterium Acidaminococcus fermentans is catalysed by a membrane‐bound, biotin‐dependent enzyme which requires Na+ for activity. Inverted vesicles from A. fermentans accumulated Na+ only if glutaconyl‐CoA was decarboxylated. The Na+ uptake was inhibited by avidin but not by the avidin biotin complex. Detergents and ionophores such as monensin also prevented the Na+ transport. The results indicate that the enzyme is able to convert the free energy of decarboxylation (ΔG
o′ ≈−30 kJ/mol) into a Na+ gradient.
A further characterisation of the B890 light‐harvesting pigment—protein complex from Rhodospirillum rubrum strain S1
Authors: Cogdell Richard J. , Lindsay J.Gordon , Valentine Jane , Durant Irene
Published: July 2002

An intact B890 light‐harvesting pigment—protein complex has been obtained from Rhodospirillum rubrum strain S1. We show that this complex contains two types of low‐M
r polypeptide. Both these polypeptides are present in the intact chromatophore membrane. Analysis of the pigment content of this complex suggests that per pair of polypeptides the complex contains 2 molecules of bacteriochlorophyll and one molecule of carotenoid.
Induction of ornithine decarboxylase by treatment of guinea pig lymphocytes with phospholipase C
Authors: Kuramoto Ayako , Otani Shuzo , Matsui Isao , Morisawa Seiji
Published: July 2002

Treatment of guinea pig lymphocytes with Clostridium perfringens phospholipase C but not with Naja naja snake venom phospholipase A2 increased ornithine decarboxylase activity. The increase in ornithine decarboxylase activity was suppressed by actinomycin D or cycloheximide, suggesting that de novo syntheses of RNA and protein are necessary for the increase in the enzyme activity. These results suggest that the activation of phospholipase C rather than that of phospholipase A2 is responsible for induction of ornithine decarboxylase during lymphocyte transformation.
Arginine activation of N‐acetylglutamate synthetase in mouse liver
Authors: Kawamoto Susumu , Tatibana Masamiti
Published: July 2002

N‐Acetyl‐L‐glutamate sythetase catalyzes the synthesis of N‐acetyl‐L‐glutamate, an allosteric and esential activator of carbamoyl‐phosphate synthetase I in the liver of ureotelic animals. The enzyme is activated specifically by arginine. We report here that the sensitivity of the synthetase to activation by arginine increases markedly after intraperitoneal administration to mice of inhibitors of nucleic acid and protein synthesis, including actinomycin D, aurintricarboxylic acid, cycloheximide, emetine and puromycin. The effects of cycloheximide were investigated in detail and an amino acid analysis was made of the homogenate of freeze‐clamped livers of control or cycloheximide‐treated mice.
High affinity binding of [125I]monoiodoapamin to isolated guinea‐pig hepatocytes
Authors: Cook Nigel S. , Haylett Dennis G. , Strong Peter N.
Published: July 2002

The bee venom neurotoxin apamin has been labelled with 125I and its binding to isolated guinea‐pig hepatocytes measured under physiological conditions. A single saturable component of [125I]monoiodoapamin binding with a K
d of 350 pM and B
max of 0.99 fmol/mg dry wt was identified. Native apamin displaced labelled apamin with a K
d of 376 pM which is broadly in keeping with the concentrations found to inhibit K loss from guinea‐pig hepatocytes. These observations, together with the binding found in other tissues, suggest that specific binding of labelled apamin is particularly associated with apamin‐sensitive, Ca‐activated K‐channels.
Novel cell‐binding activity specific for N‐acetyl‐D‐glucosamine in an Escherichia coli strain
Authors: Väisänen-Rhen Vuokko , Korhonen Timo K. , Finne Jukka
Published: July 2002

Escherichia coli strains isolated from patients with different levels of urinary tract infection and from healthy persons were tested for their ability to haemagglutinate endo‐β‐galactosidase‐treated human erythrocytes. Among the 104 strains studied one revealed a strong agglutination reaction with the enzyme‐treated erythrocytes. From the monosaccharides tested N‐acetyl‐D‐glucosamine inhibited agglutination most effectively. Orosomucoid and asialo‐orosomucoid had no effect on the haemagglutination whereas β‐galactosidase treated asialo‐orosomucoid was inhibitory. These findings indicate that the E. coli strain studied contains a novel cell‐binding activity with specificity for terminal N‐acetyl‐D‐glucosamine residues.
Lamprey 48‐kDa lens protein represents a novel class of crystallins
Authors: Stapel Steven O. , de Jong Wilfried W.
Published: July 2002

SDS—PAGE revealed a major M
r 48000 polypeptide of pI around 8 in the water‐soluble fraction of lamprey lenses. It occurs as a monomeric protein, and its amino acid composition and tryptic peptides show no resemblances to α‐, β‐, γ‐ or δ‐crystallin. Immunoblotting with antiserum against the 48‐kDa protein revealed an immunologically related polypeptide of similar M
r in reptiles, several birds and a fish, but showed no cross‐reactivity with any other water‐soluble lens component. The 48‐kDa protein is not detected in many birds and fishes, and in the investigated mammals and amphibians.
Modulation of membrane fluidity by catalytic hydrogenation affects the chilling susceptibility of the blue‐green alga, Anacystis nidulans
Authors: Vigh L. , Joó F.
Published: July 2002

All the changes, i.e. the phase separation temperature of thylakoid lipids, shift in the chilling induced increase of K+ permeability and decline in photosynthetic O2‐production, respectively, brought about by temperature acclimation in Anacystis nidulans, can be accomplished by homogeneous catalytic hydrogenation of the fatty acids, as well, using a new water‐soluble Pd(II) complex, hitherto unknown in biological applications. Since the thermo‐adaptation replaced by proper hydrogenation conducted under isothermal condition results in a similar modification of chilling susceptibility, it afforts direct evidence that chilling response is mediated by changing the degree of fatty acid unsaturation in Anacystis nidulans.
Monovalent carboxylic ionophores inhibit transport of carbomoyl‐phosphate synthetase I into mitochondria in Reuber hepatoma H‐35 cells and cause accumulation of enzyme precursor
Authors: Kitagawa Yasuo , Murakami Akihiko , Sugimoto Etsuro
Published: July 2002

Transport of the precursor for carbamoyl‐phosphate synthetase I into mitochondria in Reuber hepatoma H‐35 cells was inhibited by adding monensin or nigericin to the culture medium at a concentration of 0.5 μM, and the enzyme precursor accumulated, mainly in the cytosolic fraction. Accumulated precursor was degraded slowly with a half‐life of more than 16 min. Valinomycin, nonactin, A23187, X‐537A (lasalocid), bromo‐lasalocid, and carbonyl cyanide m‐chlorophenylhydrazone did not exhibit these effects at concentrations at which they did not inhibit protein synthesis of the cells.
Ribosomal protein L16 binds to the 3′‐end of transfer RNA
Authors: Maimets Toivo , Remme Jaanus , Villems Richard
Published: July 2002

Escherichia coli 50 S ribosomal subunits were reconstituted with and without protein L16 present. The latter particles, although active in puromycin reaction, were unable to use CACCA‐Phe as an acceptor substrate. We also found that L16 interacts directly with this oligonucleotide and, in the complex with tRNA, protects its 3′‐end from pancreatic ribonuclease digestion. We suggest that the role of L16 is in the fixation of the aminoacyl stem of tRNA to the ribosome at its A‐site.
Synthesis and partial maturation of the α‐ and γ‐subunits of the mouse submaxillary gland nerve growth factor in Xenopus laevis oocytes
Authors: Wion Didier , Dicou Eleni , Brachet Philippe
Published: July 2002

Sera raised against the α‐, β‐ and γ‐subunits of the mouse 7 S NGF were used to characterize translation products coded by submaxillary gland mRNAs microinjected into Xenopus oocytes. Anti‐βNGF sera did not cross‐react with any material. In contrast, the precursors of the α‐ and γ‐subunits, as well as that of renin were identified. Use of tunicamycin, and a comparison of the translation products obtained in oocytes or in the reticulocyte lysate indicated that oocytes achieved the cleavage of signal sequences, the glycosylation of the α‐ and γ‐precursors, and the subsequent secretion of the 3 proteins. In the submaxillary gland, however, the mature forms of αNGF, γNGF and renin are composed of peptides of smaller size than those produced by the oocytes. These latter appear to lack specific proteases involved in the terminal processing of the submaxillary gland proteins.
Correlative variations of the free energies for enzyme‐substrate complex formation and the transition‐state stabilization for RNases
Authors: Yakovlev Gennady I. , Bocharov Alexander L. , Moiseyev Gennady P.
Published: July 2002

It was found for RNases of different specificities that changes in the free energy for substrate‐enzyme binding induced by variations in the nucleotide base structure are accompanied by proportional changes in k
cat/K
m. This was considered to be a consequence of the strain in the enzyme‐substrate complex.
A highly basic N‐terminal extension of the mitochondrial matrix enzyme ornithine transcarbamylase from rat liver
Authors: Mclntyre Peter , Graf Lynda , Mercer Julian , Peterson Gregory , Hudson Peter , Hoogenraad Nicholas
Published: July 2002

We have deduced the amino acid sequence of the N‐terminal leader peptide of the mitochondrial enzyme ornithine transcarbamylase from a cDNA clone obtained from a rat liver cDNA library. The sequence is remarkable in being highly basic, having 4 arginine, 3 lysine and 1 histidine with no acidic residues in a total of 32 residues. The leader sequence has no extensive hydrophobic stretches, has 72% homology with the leader peptide of human ornithine transcarbamylase [1], and in terms of its basic character resembles the N‐terminal extensions on a number of fungal mitochondrial [2‐5] and pea chloroplast [6] proteins. Thus the basic nature of these leader peptides may constitute the signal for mitochondrial import.
Hb Okazaki [β93(F8) Cys → Arg], a new hemoglobin variant with increased oxygen affinity and instability
Authors: Harano Keiko , Harano Teruo , Shibata Susumu , Ueda Satoshi , Mori Hiroo , Seki Masami
Published: July 2002

A new abnormal hemoglobin, Hb Okazaki [β93(F9) Cys → Arg], with an amino acid substitution at the tyrosine pocket of the β chain as well as at the α2β1 contact of the quaternary structure of molecule, was discovered in a Japanese man. This hemoglobin showed increased oxygen affinity and molecular instability.
Movement of the 3'‐end of 16 S RNA towards S21 during activation of 30 S ribosomal subunits
Authors: Odom O.W. , Stöffler G. , Hardesty B.
Published: July 2002

Fluorescence techniques were used to study conformational changes that occur in inactive E. coli 30 S ribosomal subunits during activation by heating in 12 mM Mg2+. Activation is associated with movement of a fluorophore on the 3'‐end of 16 S RNA into a less polar environment and towards a probe on the cysteine thiol of ribosomal protein S21. The conformational change causes an apparent decrease in distance between the probes from 59 to 52 Å as determined by non‐radiative energy transfer.
Complete nucleotide sequence of RNA 5 from cucumber mosaic virus (strain Y)
Authors: Hidaka Soh , Ishikawa Kiichi , Takanami Yoichi , Kubo Susumu , Miura Kin-ichiro
Published: July 2002

Cucumber mosaic virus Nucleotide sequence RNA 5
Structure of the retinal chromophore in halorhodopsin
Authors: Alshuth T. , Stockburger M. , Hegemann P. , Oesterhelt D.
Published: July 2002

Resonance Raman (RR) spectra of the light‐driven chloride pump halorhodopsin (HR) were recorded after isolation of the protein from cell membranes of Halobacterium halobium. The spectra of the unphotolyzed state HR578 were compared with those of two unphotolyzed species of the light‐driven proton pump bacteriorhodopsin, BR570 and BR548, which were obtained from light‐ and dark‐adapted purple membranes. Identical structural components in the retinal chromophores of HR578 and BR570 are found, both having the all‐trans configuration of the retinal chain and a protonated Schiff base linkage to the protein with anti‐position of the two hydrogens. Only minor conformational differences between the chromophoric structures in the two proteins could be inferred from the vibrational structure of the RR spectra. The function of the two chromophores as triggers of light‐induced chloride or proton transport emphasizes the role of the protein part in the ion specificity of the pumps.
Tetrahydromethanopterin, a coenzyme involved in autotrophic acetyl coenzyme A synthesis from 2 CO2 in Methanobacterium
Authors: Länge S. , Fuchs G.
Published: July 2002

Methanobacterium thermoautotrophicum, a methane forming archaebacterium, grows autotrophically by synthesizing activated acetic acid from 2 CO2. It is demonstrated in vitro that the methyl group of acetate is derived from methenyl tetrahydromethanopterin, which is known to be a one‐carbon carrying coenzyme in CO2 reduction to methane. The direct acetate precursors are suggested to be methyl tetrahydromethanopterin (“activated methanol”) and “activated carbon monoxide”.
Spermine promotes the translocation of phosphatidate phosphohydrolase from the cytosol to the microsomal fraction of rat liver and it enhances the effects of oleate in this respect
Authors: Martin-Sanz Paloma , Hopewell Roger , Brindley David N.
Published: July 2002

Spermine (0.5–2 mM) promoted the translocation of phosphatidate phosphohydrolase from the soluble to the microsomal fraction in a cell‐free system derived from rat liver. By contrast, spermidine (1 mM) and putrescine (1 mM) had no significant effect on the translocation when added alone. Spermine, and to a lesser extent, spermidine, enhanced the translocating action of oleate and increased its effectiveness in transferring the phosphohydrolase from the soluble ot the microsomal fraction. It is proposed that the phosphohydrolase becomes metabolically active when it combines with membranes and that polyamines might help to regulate this interaction. This could facilitate the action of fatty acids and enable cells to increase their capacity for triacylglycerol synthesis to match an increased availability of fatty acids.
The phosphate potential maintained by mitochondria in State 4 is proportional to the proton‐motive force
Authors: Woelders Henri , van der Zande Wim J. , Colen Anne-Marie A.F. , Wanders Ronald J.A. , van Dam Karel
Published: July 2002

Evidence is presented for a proportional relationship between the extramitochondrial phosphate potential (ΔG
ex
p) and the proton‐motive force (ΔgmH+
) across the mitochondrial membrane in rat‐liver mitochondria oxidising succinate in State 4, when ΔgmH+
is varied by addition of uncouplers or malonate. This relationship was found when precautions were taken to minimise interference with the determination of ΔG
p
ex and ΔgmH+
by intramitochondrial nucleotides, adenylate kinase activity, the quenching method, and ΔgmH+
‐dependent changes in matrix volume. A non‐proportional ΔG
p
ex/ΔgmH+
relationship was obtained when these precautions were omitted. Our results do not support mosaic protonic coupling, but are not necessarily in conflict with other localised coupling schemes.
Stimulation of the respiratory and phosphorylating activities in rat brain mitochondria by idebenone (CV‐2619), a new agent improving cerebral metabolism
Authors: Sugiyama Yasuo , Fujita Takeshi
Published: July 2002

The effects of 6‐(10‐hydroxydecyl)‐2,3‐dimethoxy‐5‐methyl‐l,4‐benzoquinone (CV‐2619) on the respiration and non‐respiratory oxygen consumption induced by ascorbate and Fe2+ in rat brain mitochondria were studied. When CV‐2619 (100 and 300 ) was orally administered to rats for 3 days, it increased the state 3 respiration stimulated by ADP, slightly decreased the state 4 respiration after the consumption of ADP and resulted in a significant increase of the respiratory control index (RCI) by 14–19% for glutamate oxidation(P<0.01) and 10–17% for succinate oxidation (P<0.05), respectively. The RCI increasing effect of CV‐2619 was dose dependent, but the compound had no effect on the ADP/O ratio. CV‐2619 significantly suppressed by about 10% the non‐respiratory oxygen consumption (P<0.02), which closely associated with non‐enzymatic reactions such as lipid peroxidation, membrane lysis and swelling of mitochondria. Thus, CV‐2619 may contribute to stimulate the net ATP formation by the well‐coupling of electron and energy transfer, and by the reduction of non‐respiratory oxygen consumption in cerebral metabolism.
Conformational changes induced by Mg2+ on actin monomers
Authors: Roustan C. , Benyamin Y. , Boyer M. , Bertrand R. , Audemard E. , Jauregui-Adell J.
Published: July 2002

The effect of Mg2+ ions on the conformation of G‐actin and in particular on the accessibility of its antigenic regions has been tested. Experiments were performed with G‐actin coupled to Sepharose 4B which was, therefore, maintained in the monomeric state. The results presented her show that the 2mM MgCl2‐perturbed antigenic site is located in a central region of the actin sequence.
The site of cyclic AMP‐dependent protein kinase catalyzed phosphorylation of cytochrome P‐450 LM2
Authors: Müller R. , Schmidt W.E. , Stier A.
Published: July 2002

The phenobarbital‐inducible form of cytochrome P‐450 purified from rabbit liver microsomes is phosphorylated by cAMP‐dependent protein kinase at a single site, the serine residue in position 128 of the amino acid sequence. The serine is located in a characteristic recognition sequence for cAMP‐dependent protein kinase and is part of a primary structure which is conserved during evolution, present also in phenobarbitalinducible rat cytochrome and cytochrome P‐450 CAM from Pseudomonas putida. The contribution of these findings to our understanding of the structure and membrane topology of cytochrome P‐450 LM2 and its turnover regulated by phosphorylation is discussed.
ATP‐dependent translocation of amino phospholipids across the human erythrocyte membrane
Authors: Tilley Leann , Cribier Sophie , Roelofsen Ben , den Kamp Jos A.F.Op , van Deenen Laurens L.M.
Published: July 2002

Trace amounts of radiolabeled phospholipids were inserted into the outer membrane leaflet of intact human erythrocytes, using a non‐specific lipid transfer protein. Phosphatidylcholine, phosphatidylserine and phosphatidylethanolamine were transferred from the donor lipid vesicles to the membrane of the intact red cell with equal ease, whilst sphingomyelin was transferred 6‐times less efficiently. The transbilayer mobility and equilibrium distribution of the labeled phospholipids were assessed by treatment of the intact cells with phospholipases. In fresh erythrocytes, the labeled amino phospholipids appeared to move rapidly towards the inner leaflet. The choline phospholipids, on the other hand, approached an equilibrium distribution which strongly favoured the outer leaflet. In ATP‐depleted erythrocytes, the relocation of the amino phospholipids was markedly retarded.