bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular modeling of cornulin (CRNN) for docking with phytocompounds from Justicia adhatoda L.
Authors:   Department of Biochemistry, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai - 600 077, India, Selvaraj Jayaraman
Published: February 2021

Cornulin (CRNN) is linked with tumour progression. Therefore, it is of interest to document data on the molecular modeling of cornulin (CRNN) for docking with phytocompounds (Pyrazinamide, Anisotine, Vasicinone, Vasicoline) from Justicia adhatoda L. Thus, we document the optimal binding features of these compounds with the cornulin model for further consideration
ЛИНГВОСТРАНОВЕДЕНИЕ КАК СОСТАВНАЯ ЧАСТЬ ИЗУЧЕНИЯ ИНОСТРАННОГО ЯЗЫКА: ЛЕКСИКОГРАФИЧЕСКИЙ АСПЕКТ
Authors:   Ивановский филиал Российского экономического университета им. Г.В. Плеханова, Егошина Нина Борисовна
Published: February 2021

В данной статье ставится цель доказать, что изучение иностранного языка как средства общения невозможно без изучения культурной и общественной жизни народа страны изучаемого языка. Знакомство с миром носителей языка способствует пониманию особенностей речевого построения, дополнительных смысловых нагрузок, политических, исторических, культурных коннотаций слов и высказываний. Социологические исследования, широко используемые в научной работе кафедры гуманитарных и естественнонаучных дисциплин Ивановского филиала РЭУ им. Г.В. Плеханова, подтвердили тот факт, что собственно языковых знаний совершенно недостаточно для успешного овладения иностранным языком. Лингвистическая информация должна сопровождаться фактами, относящимися к историко-культурному фону, т.е. к той естественной среде, в которой язык живет и развивается. Главный вывод статьи: Лингвострановедение, в каком бы объёме эта дисциплина ни была представлена в общей программе по иностранному языку, позволяет расширить культурный и исторический кругозор студентов, совершенствовать общую филологическую подготовку, формировать навыки работы с лингвистическими и экстралингвистическими объектами.
Le façonnement des élites économiques québécoises par la financiarisation des entreprises
Authors: Laurin-Lamothe Audrey
Published: February 2021

L’article décrit les caractéristiques structurantes du phénomène de la financiarisation des entreprises et cherche à montrer comment ce régime d’accumulation contribue à la transformation des élites économiques. La présente étude des réseaux sociaux d’entreprises et d’organisations québécoises a permis de comparer l’élite économique et l’élite financière, la première se rattachant au processus d’accumulation capitaliste en général et la seconde à la dynamique de financiarisation en particulier. Les résultats ont montré que l’élite financière, sur les plans du profil individuel et professionnel ainsi que du pouvoir qu’elle exerce, était mieux en mesure que l’élite économique de maximiser ses intérêts, de profiter de la crise financière de 2008 et de consolider ses liens dans le réseau.
Les héritiers du Québec. Le rôle de l’école privée et du capital culturel dans la diplomation universitaire chez les enfants issus des élites
Authors: Moulin Stéphane , Gingras Guillaume
Published: February 2021

Dans cet article, nous dressons une cartographie des élites au Québec et de leurs stratégies de fréquentation de l’école privée, et nous comparons la diplomation universitaire des enfants issus de différentes fractions de ces élites. Nous observons comment les élites se différencient selon le type de capital détenu par les parents (capital culturel ou économique) et selon le type d’établissement secondaire fréquenté (public ou privé). Nous montrons que les enfants des élites culturelles sont surreprésentés dans le privé et que l’effet de la scolarisation dans le privé sur les chances d’obtention d’un diplôme universitaire au Québec est entièrement modéré par un effet de composition culturelle, soit le fait qu’un fort pourcentage des élèves de ces écoles secondaires ont des parents diplômés de l’université. C’est donc doublement que l’on peut parler d’un primat du capital culturel dans l’explication de la réussite scolaire des élites, en distinguant d’une part l’effet direct du capital culturel de la famille et, d’autre part, l’effet indirect de la concentration de parents diplômés universitaires dans les écoles.
Vivre en milieu périurbain : rapport au lieu et lien social. Le cas des Grandbasilois
Authors: Benoit Carmelle
Published: February 2021

Les changements sociaux contemporains liés à l’expansion de la banlieue et du milieu périurbain sont l’objet de préoccupations quant au rôle du rapport au lieu et de ses conséquences sur la détermination des liens sociaux et des interdépendances entre les individus. On peut se demander si, dans les circonstances, le lien social est affaibli voire menacé. Une étude de cas composée de quarante et un entretiens semi-dirigés effectués auprès de citoyens de la ville de Saint-Basile-le-Grand sur la Rive-Sud de Montréal nous sert d’outil d’analyse. En résultat, nous constatons un rapport au lieu marqué, à savoir un enracinement local et un ancrage familial soutenu qui témoigne d’un caractère familialiste et « localiste ». La sociabilité et les interrelations sociales sont notables et le rôle des enfants y est prépondérant. Le sentiment d’appartenance et l’identité sociale sont manifestes. Le portrait n'est toutefois pas unilatéral : individualité et sociabilité, engagement et distanciation, autonomie et isolement créent des tensions chez les individus et laissent poindre un rapport au lieu et des liens sociaux reconfigurés.
L’utilisation militaire de l’espace extra-atmosphérique est-elle licite selon le droit international public?
Authors: Imhof Pascal
Published: February 2021

Cette contribution décrit la situation juridique actuelle de l’utilisation militaire de l’espace extra-atmosphérique au sens du droit international public. Les principales étapes de la course à l’espace, ses utilisations à des fins militaires et les technologies militaires actuelles utilisées dans cet environnement singulier sont brièvement présentées. Les principales caractéristiques du droit de l’espace sont ensuite décrites succinctement. À travers un exercice d’interprétation critique des dispositions pertinentes de traités du droit de l’espace, du droit de la maîtrise des armements, de droit international général, mais également de droit international humanitaire, cette étude montre dans quelle mesure la militarisation de l’espace est bel et bien licite à ce jour. De plus, cet article démontre en quoi le déploiement d’armements dans l’espace ne contrevient pas, malgré quelques interdictions spécifiques, aux normes de droit international en vigueur. Actuellement, face à l’incapacité des institutions onusiennes à préciser la situation juridique et aux apports très limités des instruments non contraignants en la matière, seules des initiatives émanant de la société civile telles que le manuel de McGill et celui de Woomera, semblent être à même de clarifier, dans un futur proche, la lex lata en matière d’utilisation militaire de l’espace extra-atmosphérique.
L’exception de sécurité du GATT sous le prisme des surtaxes américaines sur l’acier et l’aluminium : une analyse à l’aune du rapport du Groupe spécial dans l’affaire Russie – Trafic en transit
Authors: Foucault Maël , Ouellet André-Philippe , Warnier Stella
Published: February 2021

L’invocation par les États membres de l’Organisation mondiale du commerce (OMC) de l’exception de sécurité prévue par l’Accord général sur les tarifs douaniers et le commerce (GATT) de 1994 constitue l’un des enjeux les plus pressants au sein de l’Organe de règlement des différends (ORD). La conclusion du Groupe spécial dans l’affaire Russie – Trafic en transit constitue une première interprétation de cette mesure d’exception prévue à l’article XXI du GATT, dont la portée met en relief le délicat équilibre entre la libéralisation du commerce international et celui de la protection des intérêts essentiels de sécurité. Compte tenu notamment de l’invocation répétée de cette exception dans des contentieux en lien avec l’acier et l’aluminium, opposant les États-Unis à sept autres membres, ce premier jalon interprétatif doit être étudié dans sa dimension politique. Il s’agit en effet d’un moyen pour le Groupe spécial de favoriser la stabilité et l’effectivité du système, et ce en refusant aux membres invoquant l’article XXI une pleine autonomie de jugement. L’importance du rapport du Groupe spécial réside dans sa construction visant à limiter un recours abusif à l’exception de sécurité de la part des membres dans un contexte d’instabilité internationale. Afin de bien apprécier la portée de ce rapport, le présent article propose trois analyses. Dans un premier temps, un retour sur les arguments des parties et des tierces parties dans l’affaire Russie – Trafic en transit permettra de contextualiser les conclusions du Groupe spécial pour traiter, dans un second temps, de la politique interprétative propre à l’ORD. Finalement, les notions d’activisme judiciaire et de la charge persuasive du rapport sont examinées à l’aune des différends en cours dans lesquels l’exception de sécurité a été invoquée. Cet exposé doit permettre d’appréhender la question des exceptions de sécurité dans le contexte plus global des défis auquel est confrontée aujourd’hui l’OMC, notamment en lien avec la paralysie de l’Organe d’appel à compter du 11 décembre 2019.
Tras el éxito de la feminidad mediática, ¿dónde queda el feminismo?
Authors: Esquirol Meritxell
Published: February 2021

No es extraño ver cómo las mujeres tenemos papeles cada vez más relevantes en la ficción televisiva y en las narraciones cinematográficas, del mismo modo que desde la industria del ocio y el entretenimiento se ofrecen productos pensados y distribuidos de una manera estratégica para los públicos femeninos. Así pues, a primera vista, podemos pensar que estamos de enhorabuena.
La actualidad terminológica compartida en la red
Authors: Vàzquez Garcia Mercè
Published: February 2021

En los últimos años la difusión de la actualidad terminológica ha pasado por un proceso de profunda transformación. Empezó siendo un boletín distribuido en papel, más adelante pasó a ser un contenido enviado periódicamente por correo electrónico –formato que actualmente todavía se mantiene muy arraigado–, para convertirse en un contenido multiformato fácil de distribuir y compartir. En estos momentos la actualidad terminológica se difunde diariamente por medio de webs institucionales, blogs personales, plataformas en línea o herramientas que permiten crear y compartir información, y, en paralelo, se da a conocer en las redes sociales.
¿Necesitamos un día del libro?
Authors: Lalueza Ferran
Published: February 2021

Aunque en Cataluña lo celebramos desde 1926, a nivel mundial el día del libro es un invento relativamente reciente. Fue instaurado por la UNESCO en 1995, de modo que este 23 de abril cumple 20 primaveras: la misma edad que la UOC.
Riannodando le fila del discorso
Authors: Sergio Giuseppe
Published: February 2021

Old men ought to be explorers Here or there does not matter We must be still and still moving Into another intensity For a further union, a deeper communion Through the dark cold and the empty desolation, The wave cry, the wind cry, the vast waters Of the petrel and the porpoise. In my end is my beginning.
Research progress of spin-orbit torques based on two-dimensional materials
Authors: He Cong-Li , Xu Hong-Jun , Tang Jian , Wang Xiao , Wei Jin-Wu , Shen Shi-Peng , Chen Qing-Qiang , Shao Qi-Ming , Yu Guo-Qiang , Zhang Guang-Yu , Wang Shou-Guo ,   Institute of Advanced Materials, Beijing Normal University, Beijing 100875, China,   Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China,   Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Hong Kong 999077, China
Published: February 2021

The spin-orbit torque generated by charge current in a strong spin-orbit coupling material provides a fast and efficient way to manipulate the magnetic moment in adjacent magnetic layers, which is expected to be used for developing low-power, high-performance spintronic devices. Two-dimensional materials have attracted great attention, for example, they have abundant species, a variety of crystal structures and symmetries, good adjustability of spin-orbit coupling strength and conductivity, and good ability to overcome the lattice mismatch to form high-quality heterojunctions, thereby providing a unique platform for studying the spin-orbit torques. This paper covers the latest research progress of spin-orbital torques in two-dimensional materials and their heterostructures, including their generations, characteristics, and magnetization manipulations in the heterostructures based on non-magnetic two-dimensional materials (such as MoS2, WSe2, WS2, WTe2, TaTe2, MoTe2, NbSe2, PtTe2, TaS2, etc.) and magnetic two-dimensional materials (such as Fe3GeTe2, Cr2Ge2Te6, etc.). Finally, some problems remaining to be solved and challenges are pointed out, and the possible research directions and potential applications of two-dimensional material spin-orbit torque are also proposed.
Implementation of the computer tomography parallel algorithms with the incomplete set of data
Authors: Pleszczyński Mariusz
Published: February 2021

Computer tomography has a wide field of applicability; however, most of its applications assume that the data, obtained from the scans of the examined object, satisfy the expectations regarding their amount and quality. Unfortunately, sometimes such expected data cannot be achieved. Then we deal with the incomplete set of data. In the paper we consider an unusual case of such situation, which may occur when the access to the examined object is difficult. The previous research, conducted by the author, showed that the CT algorithms can be used successfully in this case as well, but the time of reconstruction is problematic. One of possibilities to reduce the time of reconstruction consists in executing the parallel calculations. In the analyzed approach the system of linear equations is divided into blocks, such that each block is operated by a different thread. Such investigations were performed only theoretically till now. In the current paper the usefulness of the parallel-block approach, proposed by the author, is examined. The conducted research has shown that also for an incomplete data set in the analyzed algorithm it is possible to select optimal values of the reconstruction parameters. We can also obtain (for a given number of pixels) a reconstruction with a given maximum error. The paper indicates the differences between the classical and the examined problem of CT. The obtained results confirm that the real implementation of the parallel algorithm is also convergent, which means it is useful.
Extremely low nucleotide diversity among thirty-six new chloroplast genome sequences fromAldama(Heliantheae, Asteraceae) and comparative chloroplast genomics analyses with closely related genera
Authors: Loeuille Benoit , Thode Verônica , Siniscalchi Carolina , Andrade Sonia , Rossi Magdalena , Pirani José Rubens
Published: February 2021

Aldama(Heliantheae, Asteraceae) is a diverse genus in the sunflower family. To date, nearly 200 Asteraceae chloroplast genomes have been sequenced, but the plastomes ofAldamaremain undescribed. Plastomes in Asteraceae usually show little sequence divergence, consequently, our hypothesis is that species ofAldamawill be overall conserved. In this study, we newly sequenced 36 plastomes ofAldamaand of five species belonging to other Heliantheae genera selected as outgroups (i.e.,Dimerostemma asperatum, Helianthus tuberosus, Iostephane heterophylla, Pappobolus lanatusvar. lanatus, and Tithonia diversifolia). We analyzed the structure and gene content of the assembled plastomes and performed comparative analyses withinAldamaand with other closely related genera. As expected,Aldamaplastomes are very conserved, with the overall gene content and orientation being similar in all studied species. The length of the plastome is also consistent and the junction between regions usually contain the same genes and have similar lengths. A large ∼20 kb and a small ∼3 kb inversion were detected in the Large Single Copy (LSC) regions of all assembled plastomes, similarly to other Asteraceae species. The nucleotide diversity is very low, with only 1,509 variable sites in 127,466 bp (i.e., 1.18% of the sites in the alignment of 36Aldamaplastomes, with one of the IRs removed, is variable). Only one gene,rbcL, shows signatures of positive selection. The plastomes of the selected outgroups feature a similar gene content and structure compared toAldamaand also present the two inversions in the LSC region. Deletions of different lengths were observed in the geneycf2. Multiple SSRs were identified for the sequencedAldamaand outgroups. The phylogenetic analysis shows thatAldamais not monophyletic due to the position of the Mexican speciesA. dentata. All Brazilian species form a strongly supported clade. Our results bring new understandings into the evolution and diversity of plastomes at the species level.
Spatial temporal distribution of COVID-19 risk during the early phase of the pandemic in Malawi
Authors: Ngwira Alfred , Kumwenda Felix , Munthali Eddons C.S. , Nkolokosa Duncan
Published: February 2021

Background

COVID-19 has been one of the greatest challenges the world has faced since the second world war. This study aimed at investigating the distribution of COVID-19 in both space and time in Malawi.

Methods

The study used publicly available data of COVID-19 cases for the period from 2 April 2020 to 28 October 2020. Semiparametric spatial temporal models were fitted to the number of monthly confirmed cases as an outcome data, with time and district as independent variables, where district was the spatial unit, while accounting for sociodemographic factors.

Results

The study found significant effects of location and time, with the two interacting. The spatial distribution of COVID-19 risk showed major cities being at greater risk than rural areas. Over time, the COVID-19 risk was increasing then decreasing in most districts with the rural districts being consistently at lower risk. High proportion of elderly people was positively associated with COVID-19 risk (β = 1.272, 95% CI [0.171, 2.370]) than low proportion of elderly people. There was negative association between poverty incidence and COVID-19 risk (β = −0.100, 95% CI [−0.136, −0.065]).

Conclusion

Future or present strategies to limit the spread of COVID-19 should target major cities and the focus should be on time periods that had shown high risk. Furthermore, the focus should be on elderly and rich people.
A Rare Case of Adult-onset Best Disease
Authors: Janti Siddharam S , Paul Shinisha Damodaran , Karunakaran Stephen Sudhakar
Published: February 2021

Best Disease also known as Vitelliform Macular Dystrophy (VMD), classically presents with defective central vision. Macula which is responsible for the central vision and colour perception is affected. Individuals affected by Best disease, initially have normal vision followed by decrease in central visual acuity as well as metamorphopsia. The case presented a 49-years-old female with complaints of progressive and painless defective Vision of her Left Eye (LE) with previous history of diabetes. A well-circumscribed single greyish lesion of size 0.5DD was noted in the macula, which was conformed to be Best disease.
Incidence of Cirrhotic Cardiomyopathy among Hundred Patients of Tamil Nadu, India- A Cross-sectional Study
Authors: Koushik AK , Ganesh P , Shanmuganathan S
Published: February 2021

Introduction: Cardiac dysfunction in cirrhosis may affect quality of life, prognosis and also may aggravate the course in patients undergoing invasive procedures such as surgery, insertion of a Transjugular Intrahepatic Portosystemic Shunts (TIPS), and liver transplantation. Aim: To evaluate the association of cardiomyopathy in cirrhotic patients of Tamil Nadu region in India. Materials and Methods: This cross-sectional study included 100 diagnosed cirrhotic patients. The patient’s cardiac status was obtained from Electrocardiography (ECG) and echocardiography. Liver profile was obtained from biochemical assays and ultrasonography of abdomen. The patients were classified as per cirrhosis grading system, Child Toucotte Pugh (CTP) scoring. The association was analysed using frequency analysis, percentage analysis and Chi-square test. Results: Prolonged QTc (>0.44 sec) was seen in 35% of the study population (p-value-0.014). A 10% of patients had systolic dysfunction and 25% showed diastolic dysfunction. Also, these patients showed positive troponin T and elevated Brain Natriuretic Peptide (BNP). The incidence of cardiomyopathy in cirrhotic patients was 28% in this study. Conclusion: This study established 28% incidence of cardiomyopathy in cirrhotic patients. This association may further be evaluated in larger study samples to provide a better prognosis and quality of life in cirrhotic patients treated with liver transplantation or other surgical procedures.
Computer Coding for Early Psychosis—An Innovative Pilot Study
Authors: Lecomte Tania , Corbière Marc , Cellard Caroline , Hache-Labelle Catherine , Merlo Raphaëlle , Baki Amal Abdel , Villeneuve Marie , Thériault Jean-Denis , Arthur Kate
Published: February 2021

People with psychotic disorders are at higher risk of not completing an educational degree and tend to get low-wage jobs. We offered computer coding classes to 14 participants. The training was deemed feasible, acceptable, and appeared to increase their motivation for school or work, not only in computer-related domains.
Isolation of a GABA receptor from bovine brain using a benzodiazepine affinity column
Authors: Sigel Erwin , Mamalaki Cleanthi , Eric A Barnard
Published: July 2002

Benzodiazepine receptor solubilized from bovine cortical membranes was bound to a new benzodiazepine affinity column, the synthesis of which is described. Bio‐specific elution with the benzodiazepine compound chlorazepate resulted in the elution of fractions highly enriched in specific binding for the GABA receptor agonist muscimol. Specific activity for [3H]muscimol binding was >1.3 nmol/mg protein. It is shown that [3H]flunitrazepam binding activity can be recovered by removal of chlorazepate from the purified fraction. These results strongly support a model which suggests that the 2 binding sites reside on the same physical entity.
Ontogenic appearance of Ca2+ channels characterized as binding sites for nitredipine during development of nervous, skeletal and cardiac muscle systems in the rat
Authors: Kazazoglou Théodossia , Schmid Annie , Renaud Jean-François , Lazdunski Michel
Published: July 2002

The appearance of specific receptors for the Ca2+ channel antagonist nitrendipine has been followed during the fetal and post‐natal development of rat brain without cerebellum, cerebellum, skeletal muscle and cardiac muscle. The number of nitrendipine receptors is low at the fetal stage and increases drastically during post‐natal development of brain, cerebellum, skeletal muscle and cardiac muscle. The time course of this increase is different for each type of tissue studied. No significant change in receptor ligand dissociation constant (K
d) can be detected over the development period studied. The results are discussed in relation with the known properties of the differentiation process in the four types of excitable tissues studied.
Biosynthetic relationship between the major matrix proteins of adrenal chromaffin granules
Authors: Kilpatric Lynn , Gavine Fiona , Apps David , Phillips John
Published: July 2002

The matrix of the chromaffin granule contains a family of acidic proteins, collectively known as the chromogranins. It has been suggested that this family results protease action on the major component, chromogranin A. Evidence for this has now been obtained from in vitro translation of adrenal medullary messenger RNA and immunoprecipitation of translation products using an antiserum directed against chromogranin A, but which also recognises other chromogranins.
Cyclic AMP‐dependent protein kinase stimulates the formation of polyphosphoinositides in lymphocyte plasma membrane
Authors: Sarkadi B. , Enyedi Ágnes , Faragó Anna , Mészáros G. , Kremmer T. , Gárdos G.
Published: July 2002

Inside‐out vesicles from lymphocyte plasma membrane were phosphorylated in the presence of [γ‐32P]ATP. The dissociated catalytic subunit of cyclic AMP‐dependent protein kinase stimulated both membrane protein and membrane lipid phosphorylation, indicating the presence of a phosphorylation cascade. The phosphorylated membrane lipids were analyzed by thin‐layer chromatography. Increase of 32P‐labelling stimulated by the cyclic AMP‐dependent protein kinase was found exclusively in polyphosphoinositides.
Calcium‐dependent hydrophobic interaction chromatography of calmodulin, troponin C and their proteolytic fragments
Authors: Vogel Hans J. , Lindahl Lennart , Thulin Eva
Published: July 2002

The homologous calcium‐binding proteins calmodulin and skeletal and cardiac troponin C bind in the presence of 1 mM Ca2+ to phenyl‐Sepharose and can be eluted in buffers containing chelators. Results obtained with a series of proteolytic fragments, which were prepared by limited tryptic or thrombic degradation, showed that this Ca2+‐dependent hydrophobic interaction chromatography provides a convenient method for the large scale purification of some of these peptides. Moreover, it was found that in troponin C only one Ca2+‐induced hydrophobic site is located in the amino‐terminal half of the protein, but that calmodulin contained such sites in both the amino‐ and carboxy‐terminal halves of the molecule. The probable location of the latter site is discussed.
Effect of leukotriene B4, prostaglandin E2 and arachidonic acid on cytosolic‐free calcium in human neutrophils
Authors: Lew P.Daniel , Dayer Jean-Michel , Wollheim Claes B. , Pozzan Tullio
Published: July 2002

Changes in cytosolic free calcium [Ca2+]i and release of beta‐glucuronidase in response to leukotriene B4 (LTB4) were measured in intact neutrophils loaded with the fluorescent Ca2+ indicator, quin 2. LTB4 (10−10 M or higher) caused a rapid rise in [Ca2+]i due to influx from the extracellular medium and release from intracellular pools as well as enzyme release. PGE2 (3 μM) did not alter [Ca2+]i whereas arachidonic acid (10 μM) raised [Ca2+]i. Pretreatment of cells with the chemotactic peptide FMLP inhibited the subsequent rise of [Ca2+]i induced by LTB4. Since chemotactic peptides activate the lipoxygenase pathway of arachidonic acid metabolism, it may be speculated that endogenous LTB4 generation is involved in neutrophil activation.
Epoxygenation of arachidonic acid by rat anterior pituitary microsomal fractions
Authors: Capdevila J. , Snijder G.D. , Falck J.R.
Published: July 2002

Microsomal fractions isolated from rat anterior pituitary glands catalyze the oxygenation of arachidonic acid. By a combination of Chromatographic and mass spectrometric techniques, we have identified epoxy‐eicosatrienoic acids as reaction products and thus documented the presence of an NADPH‐dependent arachidonic acid epoxygenase activity in rat adenohypophysis.
The contribution of α‐helices to the surface activities of proteins
Authors: Krebs K.E. , Phillips M.C.
Published: July 2002

The amphilicity of an α‐helical segment in a protein may be quantitated by calculating its mean helical hydrophobic moment (μH). For proteins whose hydrophobic interactions with interfaces are mediated by α‐helices, the surface pressures exerted at the air‐water interface correlate with the product () × F) where is the mean helical hydrophobic moment averaged over all helices in the entire molecule, and F is the fraction of α‐helix in the protein. Knowledge of μH permits a description of the contribution ofamphipathic α‐helices to the surface activities at the air‐water interface of serum apolipoproteins, surface‐seeking peptides, and globular water‐soluble proteins.
Proteolytic activation of tissue plasminogen activator by plasma and tissue enzymes
Authors: Ichinose Akitada , Kisiel Walter , Fujikawa Kazuo
Published: July 2002

Tissue kallikrein and factor Xa were found to activate tissue plasminogen activator (t‐PA) at a rate comparable with that of plasmin. During the activation reaction, the single‐chain molecule was converted into a two‐chain form. A slight t‐PA activating activity was also found in plasma kallikrein. Other activated coagulation factors, factor XIIa, factor XIa, factor IXa, factor VIIa, thrombin and activated protein C had no effect on t‐PA activation. t‐PA was also activated by a tissue kallikrein‐like enzyme that was isolated from the culture medium of melanoma cells. These results indicate that tissue kallikrein and factor Xa may participate in the extrinsic pathway of human fibrinolysis.
Cyclic AMP‐dependent protein kinase and Ca2+‐calmodulin stimulate the formation of polyphosphoinositjdes in a sarcoplasmic reticulum preparation of rabbit heart
Authors: Enyedi Ágnes , Faragó Anna , Sarkadi B. , Gárdos G.
Published: July 2002

A rabbit heart membrane fraction enriched in sarcoplasmic reticulum was incubated in a reaction mixture containing [γ‐32P]ATP. The catalytic subunit of cyclic AMP‐dependent protein kinase enhanced the 32P‐labelling of both phosphatidylinositol‐4‐phosphate and phosphatidylinositol‐4,5‐bisphosphate. Ca2+‐calmodulin also increased the 32P‐incorporation into both polyphosphoinositides. Upon SDS gel‐electrophoretic analysis of the membrane proteins, phospholamban was found to be concurrently phosphorylated by the exogenous catalytic subunit as well as by an endogenous Ca2+‐calmodulm‐dependent protein kinase.
Calmodulin activates adenylate cyclase from rabbit heart plasma membranes
Authors: Panchenko M.P. , Tkachuk V.A.
Published: July 2002

It was shown that calmodulin (CM) activates the adenylate cyclase (AC) of rabbit heart light sarcolemma in the presence of micromolar free Ca2+ concentrations and this effect is blocked by trifluoroperazine and troponin I. GTP (in the presence of isoproterenol) and Gpp(NH)p are able to increase the CM‐dependent activity of enzyme. It was concluded that there is no special CM‐dependent ‘form’ of AC in the heart and the common catalytic component of AC can be regulated both by CM and guanine nucleotide‐binding regulatory component (N‐protein). In the presence of Ca2+ and guanine nucleotide heart AC exists as a complex: CM‐catalytic component‐N‐protein.
Monovalent nickel in hydrogenase from Chromatium vinosum
Authors: van der Zwaan J.W. , Albracht S.P.J. , Fontijn R.D. , Slater E.C.
Published: July 2002

Redox titrations with hydrogenase from Chromatium vinosum show that its nickel ion can exist in 3, possibly 4, different redox states: the 3 +, 2 +, 1 + and possibly a zero valent state. The 1 + state is unstable: oxidation to Ni(II) occurs unless H2 gas is present. The Ni(I) coordination, but not that of Ni(III), is highly light sensitive. A photoreaction occurs on illumination. It is irreversible below 77 K, but reversible at 200 K. The rate of this photodissociation reaction in 2H2O is nearly 6‐times slower than in H2O, indicating the breakage of a nickel‐hydrogen bond. This forms the first evidence for an H atom in the direct coordination sphere of Ni in hydrogenase and for the involvement of this metal in the reaction with hydrogen.
Further characterization of cardiodigin, Na+ K+‐ATPase inhibitor extracted from mammalian tissues
Authors: Fagoo M. , Godfraind T.
Published: July 2002

This study was undertaken to characterize endogenous digitalis‐like activity in water extract from mammalian tissues. Prepurified samples obtained from guinea‐pig heart were analysed by reverse‐phase HPLC using an acetonitrile gradient. The eluent was assayed for its activity as inhibitor of human heart Na+, K+‐ATPase and digoxin‐like immunoreactivity. Both activities were recovered in the same fraction after two successive chromatographic steps. These results provide further evidence for the presence of an endogenous digitalislike factor, cardiodigin, in mammalian heart.
Subcellular localization and some properties of the enzymes hydrolysing inositol polyphosphates in rat liver
Authors: Joseph Suresh K. , Williams Rebecca J.
Published: July 2002

The hydrolysis of inositol [32P]trisphosphate (IP3) and inositol [32P]bisphosphate (IP2) has been examined in subcellular fractions of rat liver. IP3 was degraded by an enzyme located in the plasma membrane which did not degrade IP2. Cytosolic fractions were found to degrade both IP3 and IP3. The IP3 phosphatase activity of liver plasma membranes displayed a neutral pH optimum, was Mg2+ dependent and was not inhibited by high concentrations of Li+. Half‐maximal activity of the enzymes hydrolysing IP3 and IP2 was obtained with substrate concentrations in the range 1–2μM. The significance of these observations to the proposed Ca2+ ‐mobilizing role of IP3 is discussed.
Major acute phase α1‐protein of the rat is homologous to bovine kininogen and contains the sequence for bradykinin: its synthesis is regulated at the mRNA level
Authors: Cole Tim , Inglis Adam S. , Roxburgh Charles M. , Howlett Geoffrey J. , Schreiber Gerhard
Published: July 2002

Major acute phase protein
Bradykinin
Kininogen
Protein‐biosynthesis regulation
Acute phase reaction
Inflammation
Defects of thrombin‐induced protein phosphorylation in platelets from stroke‐prone spontaneously hypertensive rats
Authors: Umegaki Keizo , Ikeda Masahiko , Nakamura Kazuki , Tomita Takako
Published: July 2002

Aggregation and secretion of washed platelets from stroke‐prone spontaneously hypertensive rats (SHRSP) were greatly reduced by the development of the hypertension compared with those of platelets from agematched normotensive Wistar‐Kyoto rats (WKY). Concomitantly, thrombin‐induced phosphorylation of the 47 kDa protein in SHRSP platelets was significantly decreased. However, TPA‐induced aggregation, secretion and 47 kDa protein phosphorylation in SHRSP platelets were similar to those in WKY platelets. These results suggest that protein kinase C activity and its substrate were normally present in SHRSP platelets and that defects in the receptor‐mediated activation of protein kinase C. This defective protein phosphorylation may be an underlying mechanism for the dysfunction of SHRSP platelets.
The actin‐activated ATPase of regulated and unregulated scallop heavy meromyosin
Authors: Jackson Andrew P. , Warriner Karen E. , Wells Christine , Bagshaw Clive R.
Published: July 2002

Single‐turnover kinetic analysis indicates that scallop heavy meromyosin (HMM) preparations contain a small fraction of unregulated molecules which dominate the steady‐state ATPase activity in the absence of Ca2+. This fraction was removed by rapid centrifugation during an effective single turnover of the ATPase in the presence of actin. The maximum ATPase activity of a scallop myosin head was estimated as 10 s−1 by cross‐linking subfragment 1 to F‐actin. HMM became Ca2+‐insensitive during the cross‐linking procedure. Attachment of spectroscopic probes to the reactive thiol group of scallop HMM resulted in the retention of ATPase activity but a loss in Ca2+ sensitivity.
Characterization of furosemide‐sensitive Mg2+ influx in Yoshida ascites tumor cells
Authors: Günther T. , Vormann J. , Averdunk R.
Published: July 2002

Partially Mg2+‐depleted Yoshida ascites tumor cells took up Mg2+ after reincubation in Mg2+‐and HCO3
−‐containing media. Mg2+ influx was insensitive to ouabain, amiloride and disulfonic stilbenes, but was noncompetitively inhibited by furosemide (K
i = 0.4 mM) and bumetanide. Mg2+ influx obeyed Michaelis‐Menten kinetics with respect to Mg2+ concentration (K
m = 1.1 mM) and was sigmoidal with respect to HCO3
− concentration. Electroneutral Mg2+, HCO3
− cotransport was supposed to be the mechanism of Mg2+ influx.
Increased levels of cytochrome oxidase and sodium‐proton antiporter in the plasma membrane of Anacystis nidulans after growth in sodium‐enriched media
Authors: Molitor Véronique , Erber Walter , Peschek Günter A.
Published: July 2002

Typical rates of horse heart ferrocytochrome c oxidation by purified plasma membrane preparations of the cyanobacterium Anacystis nidulans after one week of growth at low (0.03 M) and high (0.4–0.5 M) Na+ concentrations were 15 and 170 per mg protein, respectively. Virtually no change was observed in the cytochrome oxidase activity of isolated and purified thylakoid membranes (approx. 3–5 nmol cyt per mg protein irrespective of Na+ concentration during growth). Concomitantly, the rate of whole cell respiration (oxygen uptake) and the capacity for Na+/H+ exchange (per mg dry wt cells) by 0.4 M NaCl‐grown cells were 7‐ and 5‐fold enhanced, respectively, compared with control cells. The data are in accordance with electron transport‐driven Na+ extrusion from respiring A. nidulans, primarily mediated by the plasma membrane‐bound cytochrome oxidase.
Synthesis and biological properties of two dimeric forms of human α‐atrial natriuretic peptide
Authors: Kambayashi Yoshikazu , Kawabata Tomoji , Hara Seijiro , Yamauchi Akira , Ueda Akira , Kono Masao , Doteuchi Masami , Nakamura Masuhisa , Inouye Ken
Published: July 2002

Two dimeric forms of human α‐atrial natriuretic peptide (α‐ANP) were synthesized by solution methods and compared with monomeric α‐ANP in terms of some biological and immunochemical properties. The parallel form (β'‐ANP) and the antiparallel form (β‐ANP) were equipotent in smooth muscle relaxant activity in isolated rat aorta and their ED50 values were estimated to be 1.7 × 10−8 M and 1.6 × 10−8 M, respectively. Diuretic and natriuretic responses induced by β‐ANP and β'‐ANP in anesthetized rats were equally less potent but exhibited a significantly longer duration than those induced by α‐ANP. β‐ANP and β'‐ANP possessed immunoreactivities of 60–100% and 50–90% (α‐ANP, 100% on a molar basis), respectively, with three different antisera raised against α‐ANP‐related peptides.
Large scale, rapid purification of recombinant tissue‐type plasminogen activator
Authors: Dodd I. , Jalalpour S. , Southwick W. , Newsome P. , Browne M.J. , Robinson J.H.
Published: July 2002

Recombinant tissue‐type plasminogen activator (rt‐PA) from cultures of a genetically manipulated Bowes melanoma cell line (TRBM6) was purified in batches of average volume 451 using an autoclavable, reusable, continuous chromatography system comprising zinc chelate‐Sepharose CL4B and lysine‐Sepharose CL4B. After eight successive purifications the rt‐PA was ultrafiltered to yield a preparation containing 4.9 mg protein/ml and 2.7 × 106
. Analysis by SDS‐polyacrylamide gel electrophoresis followed by staining with Coomassie brilliant blue R250 showed major protein bands at M
r = 63000 and 65000; most of the material was in the 1‐chain form. The potential usefulness of a simple, rapid continuous chromatography system that can be operated under aseptic conditions is discussed.
The accumulation of essential oils by tissue cultures of Pelargonium fragrans (Willd.)
Authors: Brown J.T. , Charlwood B.V.
Published: July 2002

Essential oils are not generally accumulated in morphologically undifferentiated cell suspension cultures. A correlation between morphological differentiation and accumulation is confirmed but it is demonstrated that this level of differentiation is not a prerequisite for product synthesis. In this paper we demonstrate that fine cell suspensions do retain their ability to synthesise essential oils and that accumulation can be induced by manipulation of the photoperiod. It is also shown that morphologically undifferentiated immobilised and aggregate cell systems are capable of essential oil synthesis.
Isolation of two different subpopulations of the light‐harvesting chlorophylla/bcomplex of photosystem II (LHCII)
Authors: Spangfort Michael , Larsson Ulla K. , Anderson Jan M. , Andersson Bertil
Published: July 2002

Isolated LHCII from spinach has been solubilized and fractionated by non‐denaturing isoelectric focusing to yield two subpopulations with different polypeptide but equal chlorophyll composition. One LHCII subpopulation contains only a 27 kDa polypeptide while the other contains the 27 and 25 kDa polypeptides in about equal amounts. The polypeptide patterns of the two subpopulations closely correspond to those suggested previously for the inner LHCII and peripheral LHCII, respectively.
The functional activity of the rat c‐Ha‐ras promoter requires the coordinate involvement of multiple elements
Authors: Damante G. , Filetti Sebastiano , Rapoport Basil
Published: July 2002

Promoter activity in the rat c‐Ha‐ras promoter region was assessed in NIH 3T3 cells using the chloramphenicol acetyltransferase (CAT) reporter gene. Promoter activity was orientation dependent. Deletion of the GC box closest to the transcriptional start site, or the upstream GC box and the two CAAT boxes, greatly diminished promoter activity. The GC boxes in the SV40 early promoter could not functionally replace the downstream c‐Ha‐ras GC box, but specifically competed for expression of rat c‐Ha‐ras promoter activity. Serum‐stimulated growth of 3T3 cells stably transfected with p035‐ras‐CAT was not associated with increased promoter activity. These data indicate that the GC and CAAT boxes in the rat c‐Ha‐ras gene are related to constitutive, and not regulatory, promoter activity, and that these elements are involved in a coordinate manner.
Does the inositol tris/tetrakisphosphate pathway exist in rat heart?
Authors: Renard D. , Poggioli J.
Published: July 2002

Appearance of two isomers of inositol trisphosphate (InsP3) was observed when [3H]inositol prelabelled rat heart ventricles were stimulated for 10 and 30 s with noradrenaline. In contrast, inositol tetrakisphosphate (InsP4) could not be detected. However the existence of the inositol tris/tetrakisphosphate pathway was demonstrated by studying [3H]inositol 1,4,5‐trisphosphate (Ins‐1,4,5‐P3) metabolism in a soluble fraction of rat heart. There, [3H]Ins‐1,4,5‐P3 was phosphorylated to form [3H]Ins‐1,3,4,5‐P4. Raising [Ca2+] from 1 nM to 1, μM increased InsP3 kinase activity by 2‐fold (EC50 for Ca2+ approx. 56 nM). This effect appeared to be due to an increase of the apparent V
max of the enzyme while the apparent K
m was unchanged.
c‐Ha‐ras gene products are potent inhibitors of cathepsins B and L
Authors: Hiwasa Takaki , Yokoyama Shigeyuki , Ha Jong-Myung , Noguchi Shigeru , Sakiyama Shigeru
Published: July 2002

c‐Ha‐ras proteins produced by Escherichia coli inhibited the activities of cathepsins B and L which had been partially purified from rat kidney. Furthermore, amino acid sequence homology between c‐Ha‐ras proteins and thiol proteinase inhibitors has been found.
Rapid filtration measurements of Ca2+ release from cisternal sarcoplasmic reticulum vesicles
Authors: Sumbilla Carlota , Inesi Giuseppe
Published: July 2002

A radioactive tracer and rapid filtration method was applied to the study of Ca2+ release from sarcoplasmic reticulum (SR) vesicles which were preloaded passively (equilibration with millimolar Ca2+) or actively (in the presence of ATP or acetyl phosphate). The method allows complete substitution of the loading mixture with release medium in constant flow, and time resolution between 0.01 and 10.0 s. Net release can be clearly distinguished from isotope exchange. The latter is prominent in longitudinal SR vesicles. Net Ca2+ release is observed only from cisternal SR vesicles, is Ca2+ (micromolar) dependent, and is accelerated by inactive ATP analogues, or ATP itself, even in the presence of Mg2+. Net release has a strong pH dependence (between 6 and 7), and very little temperature dependence (consistent with a passive channel). In media of physiological significance (1 mM ATP, 1 mM magnesium, and free Ca2+ in the micromolar range), net Ca2+ release proceeds with a rate constant of approx. 100 s−1.
cAMP‐dependent activation of protein synthesis correlates with dephosphorylation of elongation factor 2
Authors: Sitikov A.S. , Simonenko P.N. , Shestakova E.A. , Ryazanov A.G. , Ovchinnikov L.P.
Published: July 2002

The addition of 5 mM cAMP to a cell‐free translation system from rabbit reticulocytes increases the rate of protein synthesis 3–5‐fold. Lower concentrations of cAMP (0.005, 0.05 and 0.5 mM) have no effect on translation in this system. cAMP at all the concentrations tested stimulates the phosphorylation of the same pattern of polypeptides, while 5 mM cAMP additionally stimulates dephosphorylation of the 95 kDa polypeptide identified as elongation factor 2 (EF‐2). Testing of the preparations of EF‐2 with a different content of the phosphorylated form in poly(U)‐directed poly(Phe) synthesis reveals that the EF‐2 activity correlates with the fraction of non‐phosphorylated EF‐2. Thus cAMP‐dependent activation of protein synthesis seems to be due to dephosphorylation of EF‐2.
Nuclear matrix associated poly(ADP‐ribose) metabolism in regenerating rat liver
Authors: Alvarez-Gonzalez Rafael , Ringer David P.
Published: July 2002

We have examined a possible role for protein poly(ADP‐ribosylation) during in vivo DNA replication by studying the metabolism of poly(ADP‐ribose) in the nuclear matrix fraction from normal and regenerating rat liver. This fraction contains the newly replicated DNA and thus allows for the examination of the events closely associated with the replication process. It was found that 55% of the total nuclear protein‐bound poly(ADP‐ribose) and 15–35% of the total nuclear poly(ADP‐ribose)‐polymerase activity were tightly associated with this subnuclear compartment in normal liver. Surgical removal of two‐thirds of the liver initiated a time‐dependent decrease in nuclear matrix associated polymers of ADP‐ribose and poly(ADP‐ribose) polymerase activity which reached a minimum of 40% of control livers after 24 h, before returning to normal levels at 41 h post‐partial hepatectomy. In contrast, the total levels of poly(ADP‐ribose) in intact liver and the total polymerase activity of isolated nuclei exhibited a 2‐fold increase over basal levels. These results are consistent with the conclusion that the nuclear matrix is a major poly(ADP‐ribosylation) site within the nucleus and that this metabolic reaction may be closely connected with the events modulating DNA replication in this fraction.
Acid phospholipase A activities in rat hepatocytes
Authors: Kunze Hans , Löffler Bernd-Michael , Schmidt Michael
Published: July 2002

Cultured rat hepatocytes exhibit acid phospholipase A activity. On the basis of product formation from stereospecifically radiolabeled phosphatidylethanolamine substrates, phospholipases A1and A2have been identified with optimal activities at pH 4.5. According to subcellular fractionation studies, the acid phospholipases in hepatocytes appear to be located in the lysosomal compartment. Application of specific inhibitors of the biosynthesis, glycosylation, and translocation of lysosomal enzymes in hepatocyte cultures suggests a half‐life of approx. 1 day for the acid lysosomal phospholipase A1. About the same value for the half‐life was obtained for the lysosomal marker enzymes, acid phosphatase and β‐N‐acetyl‐D‐hexosaminidase.
New carbohydrate site in mutant antithrombin (7 Ile→Asn) with decreased heparin affinity
Authors: Brennan Stephen O. , Borg Jeanne-Yvonne , George Peter M. , Soria Claudine , Soria Jeannette , Caen Jacques , Carrell Robin W.
Published: July 2002

A mutant antithrombin was isolated from the plasma of a patient with pulmonary embolism. The new protein, which accounted for 55% of the antithrombin, had decreased heparin affinity and contained two components when analysed on the basis of either charge or molecular mass. Sialidase and endo‐β‐N‐acetylglucosaminidase F treatment suggested that this heterogeneity was due to a partial glycosylation occurring at a new carbohydrate attachment sequence. Peptide mapping by reverse‐phase HPLC showed that the abnormality involved the N‐terminal tryptic peptide. Sequence analysis demonstrated that the underlying mutation was 7 Ile→Asn which introduces a new Asn‐Cys‐Thr glycosylation sequence. This new oligosaccharide attachment site occupies the base of the proposed heparin‐binding site, and the finding explains the consequent decrease in heparin affinity.