bluuebunny/crossref_metadata_2025 huggingface dataset:
An exploration of the relationships of experiential avoidance (as measured by the aaq-ii and meaq) with negative affect, perceived stress, and avoidant coping styles
Authors: Allen M. Todd
Published: March 2021

Background

Current psychotherapies seek to reduce experiential avoidance (EA) which has also been put forth as a risk factor for anxiety disorders, depression, and post-traumatic stress disorder. EA is a potentially maladaptive self-regulatory tendency to avoid negative thoughts, feelings, memories, physical sensations, and other internal experiences. One unresolved issue with the most commonly used measures of EA, the Acceptance and Action Questionnaire-II (AAQ-II) which measures EA as a single factor and the Multidimensional Experiential Avoidance Questionnaire (MEAQ) which measures EA as six subdimensions, is what exactly is being measured. The AAQ-II appears to measure negative affect (NA), some aspects of avoidant coping, and psychological distress. In addition, the relationships of all the MEAQ subscales have not been thoroughly examined with these other constructs. In the current study, the relationships of AAQ-II and MEAQ scores with NA, avoidant coping styles, and perceived stress were examined.

Methods

Two-hundred undergraduates (154 females and 46 males) completed the AAQ-II and MEAQ, the Distressed Type D Personality Scale (DS-14) which includes a measure of NA, the Brief COPE which measures coping styles, and the Perceived Stress Scale.

Results

Scores on the AAQ-II had moderate positive relationships with the MEAQ total score and all MEAQ subscales with the exception of distress endurance which had a moderate negative relationship. The AAQ-II had a stronger relationship with NA, avoidant coping, and perceived stress than did the MEAQ. All MEAQ subscales had a positive relationship to NA, avoidant coping, and perceived stress with the exception of distress endurance which had a negative relationship with these constructs. While the AAQ-II is limited as a unitary measure of EA the multiple dimensions of the MEAQ may involve an extraneous factor of distress endurance. Future work should examine the relationships of the MEAQ with NA, avoidant coping and perceived stress with clinical populations.
Mass-Querade: Spontaneous Intramural Oesophageal Haematoma Following Thrombolysis in the Setting of Myocardial Infarction
Authors: Ramachandran Rajoo , Balakrishnan Sanchanaa Sree , Chinnappan Sheela , Sai MP Venkata
Published: March 2021

Spontaneous Intramural Oesophageal Haematoma (IEH) is a rare oesophageal emergency. This report describes the case of a 70-year-old diabetic male, who presented with chest pain and was started on thrombolysis as Electrocardiography (ECG) showed ST elevation Myocardial Infarction (MI). As the patient developed gum bleeding and neck swelling, thrombolysis was stopped. Computed Tomography (CT) showed a non-enhancing mediastinal mass, causing significant extrinsic compression of the distal trachea and a diagnosis of IEH, possibly secondary to thrombolysis was made. Although IEH generally resolves spontaneously with conservative management, the patient remained poorly ventilated despite intubation and expired due to cardiac arrest following failure of resuscitative efforts, eight days after the initial thrombolysis. Several cases of uncomplicated IEH where complete recovery was achieved with conservative treatment are reported in literature; however, there are fewer reports on the poorer outcomes in patients with multiple co-morbidities and co-existent clinical complications.
COVID-19 as a Catalyst for Digital Lifelong Learning and Reskilling
Authors: Hamburg Ileana
Published: March 2021

Due to COVID-19 and following social distancing many face-to-face business as well as educational activities have been replaced by digital ones. Progress towards the Sustainable Development Goal 4 (SDG4) to achieve quality education for all and lifelong learning will stagnate. But the radical changes within education due COVID-19 also open the way for new forms of lifelong learning by using e-learning platforms - digital lifelong learning. This paper is based on literature review as well as work of the author within the Study Group Lifelong Learning and projects. It presents first critical skills required in the next years for reskilling and methods and pedagogies that should be included into education and training. Secondly the necessity and advantages of digital lifelong learning during and after COVID-19 pandemic and how Sustainable Development Goal 4 (SDG 4) will be supported are shortly described. Thirdly how digital lifelong learning methods can be used in entrepreneurship education and some lifelong skills developed within projects worked by the author as well as used methods are discussed. Some conclusions and recommendations are given i.e., entreprene  urship educators should be better trained and critical in their methods and educational agencies should foster digital frameworks for entrepreneurship education. Research studies are necessary to know how entrepreneurship educators have embedded digital lifelong learning into their lessons, including positive and negative experiences, and if exists a correlation between a country level of COVID-19, country economic situation, digitalization and digital lifelong learning/entrepreneurship education.
Design, Characterization and In-vitro Evaluation of Favipiravir Orodispersible Films
Authors: Yamali Kalyan Chakravarthy , Gudipati Madhu , Nadendla Rama Rao
Published: March 2021

Introduction: Orodispersible films (ODF) is a thin strip that is mostly transparent, biodegradable and it has hydrophilic polymers that disintegrate and dissolves immediately when getting in contact with saliva. Different disintegrants play a crucial role in film properties such as organoleptic properties, film thickness, and in particular disintegration time of the film. The main reason for the development of oral films is for their prominent role in increased patient compliance among pediatrics and geriatrics by disintegrating faster, releasing the drug rapidly, without the need for water, and mostly decreasing the risk of choking.

Aim: To formulate orodispersible films of favipiravir and to study the effect of different superdisintegrants on various film properties.

Methods: The method used to prepare the film is the solvent casting method. In this method, the solution is prepared using polymer, drug, and superdisintegrants. This solution is casted on a film-forming apparatus using a spreader an instrument to obtain a thin film.

Results: The prepared oral films weights ranging from 148mg to 237mg based on the superdisintegrant concentration. The pH of the prepared films didn’t vary significantly and percent moisture absorption doesn’t have significant variation. However, the texture varied from smooth to rough and transparent to translucent. Disintegration time is varying from 28 to 42 seconds. The optimum batch formulation gave 98% of drug release.
The Most Common Causes of Transfusion-Transmitted Diseases among Blood Donors in the Middle Eastern States
Authors: Hakami Nora Yahia
Published: March 2021

The need for blood is essential, but there is no timely access to safe blood for millions of individuals who need a transfusion. Additionally, blood transfusions can also be the fastest and simplest form of checking for the existence of transfusion-transmitted diseases to the recipients. Blood safety concerns are an issue of great concern in Middle Eastern Countries in which the inaccessibility or provision of unsafe blood has an adverse effect on morbidity and mortality in the region. Additionally, many organizations and safety procedures of blood transfusion in this region need to be updated. Articles containing the key phrases Middle Eastern Countries, Blood, blood donor, blood transfusion, transfusion safety, transfusion-transmitted infections, and transfusion guidelines published from 2003 to 2020 in MEDLINE, PubMed, Scopus, and Google Scholar. Therefore, to determine the most prevalent causes of transfusion-transmitted disease among blood donors in the Middle East countries, this literature review was intended for research.

Based on the data gathered were potentially related to HBsAg and HCV prevalence in blood donors from most of the middle eastern countries. While no positive cases of either HIV Ag-Ab or syphilis antibodies have been recorded especially among the blood donated from Egypt and Saudi Arabia. Based on recent studies findings, WHO, and the Food and Drug administration   transfusion transmission of SARS-CoV-2 to recipients did not occur via blood transfusion. So that, In Middle Eastern countries, transfusion-transmitted infection remains a formidable problem. A similarly wide constellation of economic and operational challenges in the area parallels the diverse array of pathogens; this calls for a systemic solution that, as proposed by the WHO, involves regulatory, structural, and training initiatives.
Evaluation of Some Biochemical Parameters of Wistar Rats Induced by Staphylococcus aureus Isolated from Pneumonia Patients
Authors: Enwa Felix Oghenemaro , Jemikalajah Johnson Daniel , Adjekuko Collins Ohwonigho , Ogbare Clever Blessing
Published: March 2021

The effect and extent of changes in some biochemical parameters associated with pneumonia caused by Staphylococcus aureus were investigated in serum samples of Wistar rats. 0ne thousand five serum samples were collected randomly. The serum samples were tested for sodium, potassium, urea, creatinine and chloride by colorimetric methods. The concentrations of sodium ranged from 133.6±4.615 to 143.8±6.906, potassium values ranged from 5.78±1.26 to 8.02±0.779, urea gave a range of 10.143±0.69 to 14.444±2.404, chloride values ranged from 94.8±2.683 to 104.142±8.49, while creatinine values ranged from 0.489±0.033 to 1.7±2.404.  The results indicated that Staphylococcus aureus has a significant effect on the electrolyte balance causing hyperkalemia and hyponatremia when compared to normal blood value. It had a remarkable effect on creatinine level with only slight effect on urea.  There is need to monitor the electrolyte levels in Staphylococcus aureus infection since alteration in the electrolyte levels could be harmful to health.
Physico-Chemical Characterization of Paliperidone Palmitate and Compatibility Studies with its Pharmaceutical Excipients
Authors: Nadendla Rama Rao , Pinnamaneni Prachet , Morla Siva Prasad , Abhinandana Patchala
Published: March 2021

Aim: The main aim of the present study was to characterize and perform the compatibility studies of paliperidone with its excipients.

Study Design: Physico-chemical characterization and compatibility studies.

Place and Duration of the Study: Chalapathi Drug Testing Laboratory, Chalapathi Institute of Pharmaceutical Sciences, Chalapathi Nagar, Lam, Guntur-522034 between December 2020 and January 2021.

Methodology: Physico-chemical characterization and compatibility studies of paliperidone palmitate with its excipients like HPMC, lactose, magnesium stearate, talc, microcrystalline cellulose was done using the FTIR spectrophotometer, Scanning electron microscopy, X-ray diffraction, Differential scanning calorimeter.

Results: Interaction of the paliperidone palmitate with its excipients were studied by this technique. Paliperidone palmitate showed the transition at 117.920C with the specific heat of 101.9J/g. The IR spectrum of paliperidone palmitate and excipients mixture has shown a characteristic stronger band of the N-H at 3412.75cm-1, C-H at 2921.98 cm-1, stretching vibrations of C=O at 1737.47 cm-1, C=C at 1651.94 cm-1, N-O at 1541.16 cm-1 followed by C-F at 1160.46 cm-1. XRD showed good crystalline properties with relative crystallinity index of 60.01%. The photomicrographs obtained by SEM did not evidence any interaction between paliperidone palmitate and the excipients, providing visual support for the results.

Conclusion: There were no interactions of drug with selected excipients and found to be compatible. Therefore, it is a mandatory clause for the compound compatibility with various excipients in the formulation which affect the stability and efficacy of the formulation.
Vitamin D Deficiency in Patients with Attention Deficit Hyperactivity Disorder
Authors: Alruwaili Jamal
Published: March 2021

Objective: This study aimed to investigate the connection between childhood Attention Deficit Hyperactivity Disorder (ADHD) and the level of Vitamin D in the blood.

Materials and Methods: The study was undertaken in 2018 on children in the age group of 4-13 years. Twenty two children diagnosed with ADHD were selected, along with a control group comprising twenty two healthy children showing no symptoms of ADHD or any other neurological disorder or liver or kidney disease or any endocrine problem. Anyone using Vitamin D supplements was excluded from the study. Venous blood samples were acquired from the subjects and serum Vitamin D level was measured.

Results: The mean average level of Vitamin D in the research subjects exhibiting ADHD (18.60±6.33 ng/ml) was found to be lower than the control group (34.34±8.19) (P-value < 0.0005).

Conclusions: This study has shed some light on the role played by Vitamin D in maintaining the antioxidant status of the brain. The study has shown that the Vitamin D is much lower in children diagnosed with ADHD. Vitamin D increases the expression of the enzyme, Gamma-Glutamyl Transferase (GGT). This enzyme is involved in the metabolism of Glutathione, which is considered an important antioxidant in the brain.
Thermodynamic Concepts on Efficiency of Aircraft Engines
Authors: Faradiba Faradiba , Yuniarti Endah
Published: March 2021

Along with the development of engine technology to be able to produce maximum efficiency in aircraft jet engines, various modifications were made to the machine tools. Modifications are made by taking into account four main factors, namely: maximum power output, reduced engine weight, low fuel consumption and maximum aircraft payload. This research uses a meta-analysis method, namely the analysis of several research results in line with what has been done previously regarding the efficiency of aircraft jet engines. The thermodynamic concept related to the heat engine which implements the brayton cycle that maximum efficiency can be done by reducing wasted heat energy and maximizing the work produced. From this concept, several attempts to maximize aircraft efficiency, such as modification of design that have a significant impact on weight reduction, fuel barrier design with low fan pressure, high bypass design ratio are also carried out in an effort to reduce aircraft noise levels. Aircraft noise levels can also be minimized by modifying the nozzle and ejector on the engine.
Location of haem‐binding sites in the mitochondrial cytochrome b
Authors: Saraste Matti
Published: July 2002

Amino acid sequences of 6 mitochondrial cytochromes b are analysed to locate the binding sites of the two protohaems. Four invariant histidines are found in two protein segments which span the membrane. In each, two histidines are separated by 13 residues. This would place them on the same sides of α‐helices, and the protohaems could be sandwiched as bis‐imidazole complexes between the two transmembrane segments. In this model the haems are located in different halves of the bilayer; the Fe–Fe distance is about 20 Å.
Glycogen synthase in rat adipocytes and skeletal muscle is phosphorylated on both serine and threonine
Authors: Hiken Jeffrey F. , Lawrence John C.
Published: July 2002

Glycogen synthase is phosphorylated both in vivo and in vitro on multiple sites per subunit. All phosphorylations of the enzyme thus far identified occur on serines which are found in two cyanogen bromide fragments, denoted CB‐1 and CB‐2. We have immunoprecipitated [32P]glycogen synthase from rat adipocytes and epitrochlearis muscles incubated with [32P]phosphate. Phosphoamino acid analyses by two‐dimensional electrophoresis after acid hydrolysis revealed no [32P]phosphotyrosine, but significant levels of [32P]phosphothreonine (6–14% of the [32P](phosphoserine). The [32P]phosphothreonine was recovered in the large CNBr‐fragment (CB‐2), indicative of a hitherto unknown phosphorylation site(s)
Detection of a bromoperoxidase in Streptomyces phaeochromogenes
Authors: van Pée Karl-Heinz , Lingens Franz
Published: July 2002

A bromoperoxidase could be detected after fractionation in the chloramphenicol producing actinomycete, Streptomyces phaeochromogenes. This enzyme is capable of catalyzing the bromination of the antifungal antibiotic pyrrolnitrin [3‐chloro‐4‐(2‐nitro‐3‐chlorophenyl)pyrrole] in the 2‐position of the pyrrole ring. The enzyme had a pH optimum of 5.0. This procaryotic bromoperoxidase requires the presence of H2O2 and can also brominate monochlorodimedone, but cannot catalyze chlorination. This enzyme is the first haloperoxidase described from procaryotic sources.
Heat‐shock proteins during growth and sporulation of Bacillus subtilis
Authors: Todd J.A. , Hubbard T.J.P. , Travers A.A. , Ellar D.J.
Published: July 2002

Four major heat‐shock proteins (hsps) with apparent molecular masses of 84, 69, 32 and 22 kDa were detected in exponentially growing stationary phase and sporulating cells of Bacillus subtilis heat‐shocked from 30 to 43°C. The most abundant, hsp69, is probably analogous to the E. coli groEL protein. These proteins were transiently inducible by heat‐shock. Partial purification of RNA polymerase revealed several other minor hsps. One of these, a 48 kDa polypeptide probably corresponds to σ43. The synthesis of this polypeptide and at least two other proteins appeared to be under sporulation and heat‐shock regulation and was affected by the SpoOA mutation.
Thermodynamics of the binding of calcium and strontium to bovine α‐lactalbumin
Authors: Schaer Jean-Jacques , Milos Mladen , Cox Jos A.
Published: July 2002

Microcalorimetry and equilibrium gel filtration were used to determine the thermodynamic functions ΔH°, ΔG° and ΔS° guiding the interaction of Ca2+ and Sr2+ with bovine α‐lactalbumin. Two methods of nearly complete metal removal from the protein gave identical results. The single Ca‐ and Sr‐binding site, which has moderate affinity for these ions (K
ca = 2.5 × 106 M−1 and K
Sr = 5.1 × 105 M−1), displays unusually large enthalpy changes of −118 kJ · mol−1 for Ca2+ and −75 kJ·mol−1 for Sr2+. The concomitant reaction entropies equal −273 and −142 J·K−1· mol−1, respectively.
Measurement of the lateral diffusion coefficients of ubiquinones in lipid vesicles by fluorescence quenching of 12‐(9‐anthroyl)stearate
Authors: Fato Romana , Battino Maurizio , Castelli Giovanna Parenti , Lenaz Giorgio
Published: July 2002

The lateral diffusion coefficients of some ubiquinone homologues have been measured in phospholipid vesicles exploiting the fluorescence quenching of the probe 12‐(9‐anthroyl)stearate by the quinones. Diffusion coefficients higher than 10−6cm2 · s−1 have been found at 25°C, compatible with the localization of the ubiquinones in the low‐viscosity midplane region of the bilayer.
Glutamate‐glutamine metabolism in the perfused rat liver
Authors: Desmoulin F. , Canioni P. , Cozzone P.J.
Published: July 2002

13C‐NMR has been used te follow the metabolism of 13C‐enriched substrates in isolated perfused rat liver. The fate of 90% enriched [2‐13C]acetate has been studied in the perfused liver in order to investigate mitochondrial metabolism and the interrelations between cytosolic and mitochondrial pools of metabolites. Some compounds of the intermediary metabolism where found to be extensively labelled, e.g. glutamate, glutamine, acetoacetate and β‐hydroxybutyrate. Under our experimental conditions, labelling of glutamate reached a steady‐state within 30 min after the onset of perfusion of 20 mM acetate. In addition, the observed incorporation of 13C into glutamine can be linked to the operation of the glutamate‐glutamine antiport and to the high activity of cytosolic glutamate synthetase. The finding of both active glutaminase and glutamine synthetase activity in the same liver cells is evidence of the existence of an active glutamine‐glutamate futile cycle.
Reversible photochemical holeburning in Rhodopseudomonas viridis reaction centers
Authors: Boxer Steven G. , Middendorf Thomas R. , Lockhart David J.
Published: July 2002

The change in absorption of the band assigned to the primary electron donor in R. viridis reaction centers (P960) has been measured at 1.4–2.1 K following narrow bandwidth excitation at many wavelengths within the P960 absorption band. In all cases nearly the entire band was photobleached (full width at half‐maximum about 400 cm−1). This result can be explained by either an ultra‐fast decay process from the initially excited state or a substantial difference in the equilibrium nuclear configuration between the ground and excited state of the donor. The latter may arise if the excited state of the donor has substantial charge transfer character. The results suggest a charge separation step which precedes formation of a bacteriopheo‐phytin b anion.
Is phylloquinone an obligate electron carrier in photosystem I?
Authors: Palace Gerard P. , Franke James E. , Warden Joseph T.
Published: July 2002

Comparative quantitative analysis of phylloquinone content and photochemically competent P‐700 has been performed on photosystem I particles subjected to photolysis with ultraviolet irradiation. Nonirradiated control particles exhibit a phylloquinone/P‐700 stoichiometry of 1.9 ± 0.2. Photolysis of the photosystem I particles induces a progressive depletion of phylloquinone, however, photochemistry as assayed at room temperature by the photooxidation of P‐700 is unaffected. These data are not consistent with the assignment of phylloquinone as a functional intermediate at room temperature between P‐700 and the iron‐sulfur clusters, center A and center B.
On the role of the light‐harvesting B880 in the correct insertion of the reaction center of Rhodobacter capsulatus and Rhodobacter sphaeroides
Authors: Jackson W.Jim , Kiley Patricia J. , Haith Copper E. , Kaplan Samuel , Prince Roger C.
Published: July 2002

The purple, non‐sulfur photosynthetic bacteria Rhodobacter capsulatus and Rhodobacter sphaeroides have two types of pigment‐protein complexes that absorb incident light and funnel it to the photochemical reaction center. One of these, B880, is present at an essentially constant ratio to the reaction center, while the abundance of the other, B800–850, varies with growth conditions. Independent work in our two laboratories has indicated that while the absence of B800–850 permits photosynthetic growth in both organisms, the lack of B880 produces a different phenotype in the two species. Thus R. sphaeroides is still photosynthetically competent when it lacks this complex, while R. capsulatus is not. This unanticipated difference in what appear to be very closely related organisms has caused us to reexamine the properties of the two mutants simultaneously, under identical conditions. We find that the original descriptions are indeed correct; the reaction center of R. capsulatus is not correctly inserted into the photosynthetic membrane in the absence of B880, while that of R. sphaeroides is.
A unique amino acid substitution in the outer membrane protein OmpA causes conjugation deficiency in Escherichia coli K‐12
Authors: Ried Georg , Henning Ulf
Published: July 2002

The outer membrane protein OmpA of E. coli K‐12 can serve as a receptor for phages and is required for stabilizing mating aggregates during F′‐mediated conjugation. Selection for resistance to OmpA‐specific phages yields mutants with alterations in the protein at four cell surface exposed sites. It is shown that conjugation deficiency can be caused by apparently only one type of amino acid substitution at one of these sites, the replacement of glycine‐154 by aspartic acid. This suggests that, in contrast to binding of phages, a ligand of the donor cell recognizes only a very small area of the protein.
On the role of transducin GTPase in the quenching of a phosphodiesterase cascade of vision
Authors: Arshavsky V.Yu. , Antoch M.P. , Philippov P.P.
Published: July 2002

The rate of GTP hydrolysis in the active site of transducin and that of the release of the phosphate thus formed have been measured. The former step has been found to be a rate‐limiting one. The rate constant for GTP hydrolysis is equal to 0.027 s−1 at 23°C, and 0.07 s−1 at 37°C. Bedsides, it has been shown that the rate of GTPase reaction on the transducin α‐subunit does not depend on the concentration of a complex of transducin β‐ and γ‐subunits or on the presence of cGMP phosphodiesterase and a 48 kDa protein from rod outer segments. According to the results, GTP hydrolysis on transducin proceeds too slowly to account for the rapid quenching of a phosphodiesterase cascade in rod outer segments.
Are guanine nucleotide‐binding proteins involved in regulation of thylakoid protein kinase activity?
Authors: Millner Paul A.
Published: July 2002

The slow ATP‐induced decrease in chlorophyll fluorescence associated with the phosphorylation of LHC II seen in spinach thylakoids was inhibited by GTP and its non‐hydrolysable analogues β, γ‐imidoguanosine 5′‐triphosphate and guanosine 5′‐O‐(3‐thiotriphosphate), but not by other nucleotide triphosphates or diphosphates. Inhibition by guanosine 5′‐O‐(3‐thiotriphosphate) appeared to require prior exposure of the thylakoid membranes to the guanine nucleotide under conditions where the protein kinase was active but unable to turnover. Binding studies with thylakoid membranes using [5′,8‐3H]GTP or [35S]guanosine 5′‐O‐(3‐thiotriphosphate) show that under similar conditions an increase in specific binding of these radiolabelled nucleotides occurs. The data presented provide evidence for the existence of a guanine nucleotide‐binding regulatory protein that is able to interact with the thylakoid protein kinase.
Amino acid sequences of the human kidney cathepsins H and L
Authors: Ritonja Anka , Popović Tatjana , Kotnik Matjaž , Machleidt Werner , Turk Vito
Published: July 2002

The complete amino acid sequences of human kidney cathepsin H (EC 3.4.22.16) and human kidney cathepsin L (EC 3.4.22.15) were determined. Cathepsin H contains 230 residues and has an M
r of 25 116. The sequence was obtained by sequencing the light, heavy and mini chain and the peptides produced by cyanogen bromide cleavage of the single‐chain form of the enzyme. The glycosylated mini chain is a proteolytic fragment of the propeptide of cathepsin H. Human cathepsin L has 217 amino acid residues and an M
r of 23720. Its amino acid sequence was deduced from N‐terminal sequences of the heavy and light chains and from the sequences of cyanogen bromide fragments of the heavy chain. The fragments were aligned by comparison with known sequences of cathepsins H and L from other species. Cathepsins H and L exhibit a high degree of sequence homology to cathepsin B (EC 3.4.22.1) and other cysteine proteinases of the papain superfamily.
The interaction between the 33 kDa manganese‐stabilising protein and the D1/D2cytochrome b‐559 complex
Authors: Gounaris Kleoniki , Chapman David J. , Barber James
Published: July 2002

Using affinity chromatography with the extrinsic 33 kDa protein as the immobilised ligand, it was demonstrated that the reaction centre complex of photosystem II, composed of the D1, D2 and cytochrome b‐559 polypeptides, can directly interact with the 33 kDa protein. By this approach it was possible to purify the reaction centre from solubilised photosystem II core complexes since neither the 47 kDa nor the 43 kDa protein would bind to the ligand.
Evidence for direct binding of vinculin to actin filaments
Authors: Ruhnau Klaus , Wegner Albrecht
Published: July 2002

The interaction of vinculin with actin filaments was investigated by methods which exclude interference by contaminating proteins which may occur in vinculin preparations. Vinculin which was blotted from SDS‐polyacrylamide gels onto nitrocellulose, was stained specifically by fluorescently labeled polymeric actin (100 mM KCl, 2 mM MgCl2). Vinculin which was purified from α‐actinin and an actin polymerization‐inhibiting protein (HA1), was found to be cosedimented with polymeric actin. Maximally one vinculin molecule was cosedimented per one hundred actin filament subunits. Half maximal binding of vinculin was observed at about 0.25 μM free vinculin. Vinculin could be replaced from actin by the addition of tropomyosin.
Translation arrest of potato virus X RNA in Krebs‐2 cell‐free system: RNase H cleavage promoted by complementary oligodeoxynucleotides
Authors: Miroshnichenko Nadezhda A. , Karpova Olga V. , Morozov Sergei Yu. , Rodionova Nina P. , Atabekov Joseph G.
Published: July 2002

Translation arrest of genomic potato virus X (PVX) RNA promoted by complementary oligodeoxynucleotides in Krebs‐2 cell‐free system is described. 14–15 mer oligodeoxynucleotides complementary to the 5′‐proximal cistron of PVX RNA were shown to induce specific truncation of the major non‐structural polypeptide coded by PVX RNA. Evidence is presented that effective translational arrest of PVX RNA in the presence of complementary oligonucleotides restults from the site‐specific cleavage of RNA by endogenous RNase H intrinsic to the Krebs‐2 extract. No similar translational arrest was found in the rabbit reticulocyte lysate cell‐free system.
Construction of a heat‐inducible chimaeric gene to increase the cytokinin content in transgenic plant tissue
Authors: Schmülling T. , Beinsberger S. , De Greef J. , Schell J. , Van Onckelen H. , Spena A.
Published: July 2002

The ipt gene of Agrobacterium tumefaciens T‐DNA encodes an isopentenyltransferase which causes cytokinin overproduction and developmental alterations in transformed plants. A chimaeric gene constructed by positioning the ipt coding region under the control of the hsp70 gene from Drosophila melanogaster allows heat‐regulated expression in transgenic plant tissue. Heat‐shock treatment of tobacco calli transgenic for the chimaeric hsipt gene increases the endogenous cytokinin concentration and enables these calli to grow on cytokinin‐free medium. Transgenic plants regenerated from calli transformed with the hsipt gene and grown at normal temperature are phenotypically normal.
Abnormal tau species are produced during Alzheimer's disease neurodegenerating process
Authors: Flament Stéphane , Delacourte André
Published: July 2002

Tau proteins were detected in human brain using two polyclonal antibodies: anti‐paired helical filaments and anti‐human native tau proteins. Both antisera detected identically the normal set of tau proteins in control brains. Moreover they detected two abnormal tau variants of 64 and 69 kDa exclusively in brain areas showing neurofibrillary tangles and senile plaques. Tau 64 and 69 were abnormally phosphorylated as revealed by the decrease in their molecular mass observed after alkaline phosphatase treatment. Therefore, tau 64 and 69 are specific markers of the neurofibrillary degeneration of the Alzheimer type and might be useful tools for studying the first pathological events that lead to neuronal death.
Phosphoinositide hydrolysis in permeabilized SH‐SY5Y human neuroblastoma cells is inhibited by mastoparan
Authors: Wojcikiewicz Richard J.H. , Nahorski Stefan R.
Published: July 2002

The effects of mastoparan on phospholipase C‐catalysed phosphoinositide hydrolysis were examined in [3H]inositol‐labelled human neuroblastoma SH‐SY5Y cells. [3H]Inositol phosphate formation in intact cells was not altered by 20 μM mastoparan. In contrast, [3H]inositol phosphate formation in electrically permeabilized cells stimulated with guanosine 5′[γ‐thio]triphosphate and/or carbachol was inhibited by mastoparan with half‐maximal effects at approx. 3 μM. The peptide was much less effective in inhibiting stimulatory effects of Ca2+. Similar but less potent inhibitory effects were observed with the cations, neomycin and spermine, indicating that direct interaction of mastoparan with polyphosphoinositides might account for its inhibitory effects on inositol phosphate formation.
Structural predictions for the central domain of dystrophin
Authors: Cross R.A. , Stewart Murray , Kendrick-Jones J.
Published: July 2002

The animo acid sequence of dystrophin indicates that the molecule has globular N‐ and C‐terminal domains separated by a long central rod domain. The central rod contains multiple repeats, about 100 amino acids long and of variable length. These diverge sufficiently in sequence that, in previous studies, only 14 of the most similar repeats have been aligned and analysed in any detail. We show here that a heptad pattern of hydrophobic residues is preserved across all repeats. Using the heptad pattern together with a consensus sequence template, we identified and aligned 25 repeats in the dystrophin rod sequence. Each repeat consists of a constant‐length core helix of 54 residues, coupled via a short linker to a weakly conserved variable‐length helix, and then via a second linker to the next core. The variable‐length helix appears truncated in repeats 10 and 13 and extended in repeats 4 and 20. The extension of repeat 20 is particularly interesting since it corresponds to a hotspot of dystrophy‐inducing mutations. Detailed modelling suggests that the classical Speicher‐Marchesi [(1984) Nature 311, 177‐180] model for spectrin may not be appropriate to dystrophin without some modification. We propose that whilst the repeating structural motif in dystrophin is probably a bead of triple coiled coil, this bead is twice as massive as, and out of phase with, those proposed for spectrin. Our model raises the possibility that the rod domain of dystrophin may confer elasticity on the molecule. Deletions which truncate this region would then reduce the extensibility of the molecule without affecting actin crosslinking, consistent with their typically producing the relatively benign Becker phenotype of muscular dystrophy.
Translocation of proteins into isolated chloroplasts requires cytosolic factors to obtain import competence
Authors: Waegemann Karin , Paulsen Harald , Soll Jürgen
Published: July 2002

The precursor form of the major‐harvesting chlorophyll a/b‐binding protein (pLHCP) of chloroplast thylakoids was overproduced in E. coli cells and used to study the influence of soluble factors on post‐translational protein import into isolated pea chloroplasts. pLHCP solubilised in 8 M urea was not import‐competent. However, if pLHCP was dialysed in the presence of soluble proteins (leaf extract) after urea treatment, import competence was gained. Dialysis of pLHCP in the presence of leaf extract alters its protease sensitivity. Stremai proteins, ovalbumin, trypsin inhibitor or chloroplast lipids could not produce import competence of pLHCP. Two components from leaf extract seem to be necessary, one of which can be mimicked by purified hsc 70, the other one requiring ATP. We conclude that soluble proteins from outside the stromal compartment are necessary for post‐translational import of proteins into chloroplasts.
Two forms of the rat D2 dopamine receptor as revealed by the polymerase chain reaction
Authors: Rao Donald D. , McKelvy Jeffrey , Kebabian John , MacKenzie Robert G.
Published: July 2002

We have used the polymerase chain reaction technique (PCR) to clone the cDNA of the D2 dopamine receptor from rat striatal mRNA. Two major PCR products were produced; one product was identical to a previously published rat cDNA, while the other, more abundant product differed only by an 87‐nucleotide insert located in the region of the putative third cytoplasmic loop of the D2 receptor. A PCR approach for determining message abundance was used to determine the relative message abundance of the two forms of the D2 receptor in a variety of tissues. Possible implications of the two forms of the D2 receptor for dopamine‐mediated signal transduction are discussed.
The primary structure of rat ribosomal protein S16
Authors: Chan Yuen-Ling , Paz Veronica , Olvera Joe , Wool Ira G.
Published: July 2002

The amino acid sequence of rat ribosomal protein S16 was deduced from the sequence of nucleotides in a recombinant cDNA and confirmed from the NH2‐terminal amino acid sequence of the protein. S16 contains 145 amino acids (the NH2‐terminal methionine is removed after translation of the mRNA) and has a molecular mass of 16304. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 11–13 copies of the S16 gene. The mRNA for the protein is about 700 nucleotides in length. Rat S16 is homologous to mouse S16 (there are 2 amino acid changes and a residue is deleted) and related to Halobacterium morismortui ribosomal protein S3 and to Escherichia coli S9.
Translational regulation of plastid gene expression in Euglena gracilis
Authors: Reinbothe Steffen , Parthier Benno
Published: July 2002

Translation of plastid messenger RNAs depends on aminoacyl‐tRNAs formed by charging plastid‐encoded tRNAs with cognate amino acids. The enzymes involved, chloroplast aminoacyl‐tRNA synthetases, are encoded in the nucleus. Both the tRNAs and the aminoacyl‐tRNA synthetases are stimulated in synthesis if dark‐grown cells are exposed to light. However, their accumulation during light‐induced chloroplast development in Euglena gracilis starts with an appreciable lag‐phase. During this period the availability of charged tRNAs probably limits protein synthesis. Due to the contemporary need of glutamyl‐tRNAGlu
GAA in chlorophyll synthesis this particular tRNA is very likely depleted. Based on an analysis of glutamate codon frequency in known plastid genes, the effect of a glutamyl‐tRNAGlu
GAA limitation on the translation of plastid messages is discussed.
The principal difference in regulation of the catalytic activity of water‐soluble and membrane forms of enzymes in reversed micelles
Authors: Kabanov Alexander V. , Nametkin Sergey N. , Levashov Andrey V.
Published: July 2002

The regularities of their functioning of enzyme, water‐soluble and membrane forms, in the systems of the reversed micelles of surfactants in organic solvents are compared. Using as examples γ‐glutamyltransferase (in AOT reversed micelles in octane) and aminopeptidase (in Brij 96 reversed micelles in cyclohexane), the principal difference in the catalytic activity regulation of water‐soluble and membrane forms is demonstrated. The catalytic activity of the membrane form depends considerably on the surfactant concentration at the constant degree of hydration, whereas the activity of the water‐soluble form is constant under these conditions. The catalytic activity dependence on the surfactant concentration is regarded as a test for enzyme membrane activity.
The octapeptide corresponding to the region of the highest homology between α‐interferon and thymosin‐α1 effectively competes with both cytokines for common high‐affinity receptors on murine thymocytes
Authors: Zav'yalov V.P. , Navolotskaya E.V. , Abramov V.M. , Galaktionov V.G. , Isaev I.S. , Kaurov O.A. , Kozhich A.T. , Malorov V.A. , Prusakov A.N. , Vasilenko R.N. , Volodina E.Yu.
Published: July 2002

The octapeptide corresponding to human interferon‐α2 (Hu IFN‐α2) sequence 131–138 hu??? high affinity to murine thymocyte receptors (K
6 = 4.2 × 10−11 M, about 700 receptors per cell). The peptide/receptor binding is inhibited by both Hu rl FN‐α1(K
1 = 8.6 × 10−10 M) and thymosin‐α1 (TM‐α1) (K
1 = 3 × 10−??? M) as well as by the octapeptide homologous to the TMα‐α1 sequence 16–23 (K
1 = 4.5 × 10−1 M). The peptide from IFN‐α1 (131–138) activates murine thymocyte blast transformation at a concentration of 10−11 M in the presence of 2.5 μ/ml of concanavalin A.
Platelet‐derived growth factor stimulates phosphorylation of the 25 kDa mRNA cap binding protein (eIF‐4E) in human lung fibroblasts
Authors: Bu Xin , Hagedorn Cert H.
Published: July 2002

Platelet‐derived growth factor exerts rapid effects on protein synthesis and polysome formation in cultured cells. We report that platelet‐derived growth factor stimulates a rapid phosphorylation of eIF‐4E in WI‐38 human lung fibroblasts. The effect was dependent on both time and PDGF concentrations. Phosphoserine was the sole phosphoamino acid identified and tryptic phosphopeptide maps showed a single phosphopeptide under both control and PDGF conditions. Phosphorylation of eIF‐4E may be one of the events required for initiating entry into G1 and commitment into S phase of the cell cycle.
Regulation of protein synthesis at the elongation stage New insights into the control of gene expression in eukaryotes
Authors: Ryazanov Alexey G. , Rudkin Brian B. , Spirin Alexander S.
Published: July 2002

There are many reports which demonstrate that the rate of protein biosynthesis at the elongation stage is actively regulated in eukaryotic cells. Possible physiological roles for this type of regulation are: the coordination of translation of mRNA with different initiation rate constants; regulation of transition between different physiological states of a cell, such as transition between stages or the cell cycle; and in general, any situation where the maintenance of a particular physiological state is dependent on continuous protein synthesis. A number of covalent modifications of elongation factors offer potential mechanisms for such regulation. Among the various modifications of elongation factors, phosphorylation of eEF‐2 by the specific Ca2+/calmodulin‐dependent eEF‐2 kinase is the best studied and perhaps the most important mechanism for regulation of elongation rate. Since this phosphorylation is strictly Ca2+‐dependent, and makes eEF‐2 inactive in translation, this mechanism could explain how changes in the intracellular free Ca2+ concentration may regulate elongation rate. We also discuss some recent findings concerning elongation factors, such as the discovery of developmental stage‐specific elongation factors and the regulated binding of eEF‐1α to cytoskeletal elements. Together, these observations underline the importance of the elongation stage of translation in the regulation of the cellular processes essential for normal cell life.
Legume lectins interact with muramic acid and N‐acetylmuramic acid
Authors: Ayouba Ahidjo , Chatelain Christian , Rougé Pierre
Published: July 2002

The inhibitory potency of both muramic acid (MurAc) and N‐acetylmuramic acid (MurNAc) on various legume lectins, including Glc/Man‐ and Gal/GalNAc‐specific lectins, was investigated by a haemagglutination inhibition technique. Data indicated that many lectins, especially those specific for Glc/Man, specifically interact with MurAc and MurNAc often to a greater extent than with other monosaccharides and their derivatives, such as N‐acetylglucosamine (GlcNAc) and sialic acid. Glc/Man‐specific lectins were also shown to interact with the muramyl‐dipeptide MurNAc‐D‐Ala‐D‐isoGln. These interactions could explain why various lectins readily agglutinate some bacterial strains or which cell walls contain peptidoglycans with high amounts of MurNAc.
Site‐directed mutagenesis reveals the importance of disulfide bridges and aromatic residues for structure and proliferative activity of human Interleukin‐4
Authors: Kruse Niels , Lehrnbecher Thomas , Sebald Walter
Published: July 2002

Mutant proteins (muteins) of human Interleukin‐4 (IL4) were constructed by means of in vitro mutagenesis. The muteins were expressed in E. coli, submitted to a renaturation and purification protocol and analysed for biological activity. Exchange of the cysteines at either position 46 or 99 which form one of the three disulfide bridges resulted in a nearly complete loss of biological activity and an unstable protein. The exchange of tyrosine 124 also inactivated the protein, while a mutation of tyrosine 56 left some residual activity. Exchange of the other four cysteines or of the single tryptophane had smaller effects.
Nucleotide sequence of a cDNA clone encoding a major allergenic protein in rice seeds Homology of the deduced amino acid sequence with members of α‐amylase/trypsin inhibitor family
Authors: Izumi Hidehiko , Adachi Takahiro , Fujii Noboru , Matsuda Tsukasa , Nakamura Ryo , Tanaka Kunisuke , Urisu Atsuo , Kurosawa Yoshikazu
Published: July 2002

A cDNA clone of rice major allergenic protein (RAP) was isolated from a cDNA library of maturing rice seeds. The cDNA had an open reading frame (486 nucleotides) which coded a 162 amino acid residue polypeptide comprising a 27‐residue signal peptide and a 135‐residue mature protein of Mr
14,764. The deduced amino acid sequence of RAP showed a considerable similarity to barley trypsin inhibitor [1983, J. Biol. Chem. 258, 7998–8003] and wheat α‐amylase inhibitor [1981, Phytochemistry 20, 1781–1784].
d‐Glyceraldehyde‐3‐phosphate dehydrogenase purified from rabbit muscle contains phosphotyrosine
Authors: Sergienko Edward A. , Kharitonenkov Alexey I. , Bulargina Tamara V. , Muronetz Vladimir V. , Nagradova Natalia K.
Published: July 2002

Homogeneous preparations of d‐glyceraldehyde‐3‐phosphate dehydrogenase purified from rabbit muscle were found to contain 0.2–0.7 moles of covalently bound phosphate per mole of the enzyme. With the use of anti‐phosphotyrosine antibodies, evidence was obtained that the enzyme is phosphorylated at tyrosine residues.
Rainbow trout ovarian cholesterol side‐chain cleavage cytochrome P450 (P450scc)
Authors: Takahashi Mika , Tanaka Minoru , Sakai Noriyoshi , Adachi Shinji , Miller Walter L. , Nagahama Yoshitaka
Published: July 2002

A cDNA clone encoding cholesterol side‐chain cleavage cytochrome P450 (P450scc) was isolated from a rainbow trout ovarian follicle cDNA library. The cDNA contains an open reading frame of 1,542 nucleotides encoding a protein of 514 amino acids. The predicted amino acid sequence of trout P450scc shows 48% homology with that of human, and 46% homology with that of rat, bovine and pig. P450scc activity was confirmed by transfected COS‐1 monkey kidney tumour cells with an expression vector for trout P450scc cDNA and subsequent detection of conversion from 25‐hydroxycholesterol to pregnenolone by radioimmunoassay. The cDNA only hybridized to a single 1.8 kb RNA transcript. The transcript was not found in early vitellogenic follicles, barely detected in postvitellogenic follicles, and abundant in postovulatory follicles.
Cell cycle regulation of deoxycytidine kinase
Authors: Hengstschläger Markus , Denk Claudia , Wawra Edgar
Published: July 2002

Deoxycytidine kinase enzyme activity and deoxycitidine kinase mRNA content were determined at different positions of the cell cycle in permanent cell lines. There was no variation of deoxycytidine kinase activity during the cell cycle in two cell lines, whereas in two other lines the enzyme activity was induced (10‐ and 15‐fold) at the G1/S boundary. In contrast, the level of deoxycytidine kinase mRNA never displayed any cell cycle‐dependent changes. The decay of enzymatic activity was measured after addition of cycloheximide in different phases of the cell cycle; the enzyme was much more stable in cells with constant activity. We suggest that post‐transcriptional mechanisms account for the periodic behaviour of the enzyme activity, and that whether this regulation can be detected depends on the half‐life of deoxycytidine kinase.
Selective inhibition of Colorado potato beetle cathepsin H by oryzacystatins I and II
Authors: Michaud Dominique , Nguyen-Quoc Binh , Yelle Serge
Published: July 2002

The use of oryzacystatins I and II, two cysteine proteinase inhibitors naturally produced in rice grains, represents an attractive way for the control of Coleoptera insect pests. The present study was done to analyze the inhibitory effect of recombinant oryzacystatins produced in Escherichia coli as fusion proteins against digestive proteinases of the major pest Colorado potato beetle (Leptinotarsa decemlineata Say). Both inhibitors had a significant effect on total proteolytic activity, but maximal inhibitions ranged from 20 to 80% for pHs varying from 5.0 to 7.0, respectively. This pH‐dependent efficiency of plant cystatins was due to the selective inactivation of potato beetle cathepsin H, as demonstrated by the use of inhibitors with different specificities against cathepsins B and H. These results demonstrate the importance of having an adequate knowledge of insect proteinases specifically recognized by the inhibitors to be used in pest control strategies.