bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructural, mechanical and pozzolanic characteristics of metakaolin-based geopolymer
Authors: Abiodun Yetunde Oyebolaji , Sadiq Obanishola Muftau , Adeosun Samson Oluropo
Published: May 2020

The use of cement contributes to global CO2 emission and this leads to the depletion of ozone layer,causing global warming. The quest to reduce or eliminate this problem has resulted in the discovery of metakaolin-based geopolymer as an alternative to the use of cement in construction work. In this study, metakaolin obtainedas a result of kaolin calcination from some deposits in Nigeria; Ogun (Imeko), Edo (Okpela), Ondo (Ifon)and Ekiti (Isan-Ekiti) were characterized and used to determine the compressive and flexural strength of metakaolin-based geopolymer concrete (Mk-GPC). Cubes of 150 × 150 × 150 mm were used for the compressive strengthtest and reinforced concrete beams of size 150 × 250 × 2160 mm were produced to test for flexural strength. A water-absorption test was also carried out on Mk-GPC and the effect of ball-milling was assessed on the strengthproperties. The results from the various tests showed that 800°C for 1 hour of calcination of kaolin gives bestcombination of performance properties due to the presence of amorphous silica in metakaolin. Mk-GPC gavehigher compressive strength and at an early age than ordinary Portland cement (OPC) concrete. The water absorptioncapacities of Mk-GPC were higher than the control samples. In the flexural strength test, the reinforcedbeams failed in flexural-shear mode and the shear capacities at 28-, 56- and 90-day curing age of the beams werebetween 0.656 and 0.938 MPa for Mk-GPC beams and between 0.563 and 0.844 MPa for the control beams. Themoment capacities for the beams were between 19.25 and 33.25 (×10³ kgm²/s²) for Mk-GPC beams and were between22.75 and 28.0 (×10³ kgm²/s²) for the control beams. The study has revealed that metakaolin-based geopolymercan serve as an alternative to cement for sustainable construction in the Nigerian construction industry.
Distribution and Abundance of Cetaceans in Icelandic Waters over 30 Years of Aerial Surveys
Authors: Pike Daniel G. , Gunnlaugsson Thorvaldur , Sigurjónsson Jóhann , Víkingsson Gísli
Published: May 2020

Beginning in 1986, 7 aerial surveys covering the coastal waters of Iceland have been conducted up to 2016. In addition, several partial surveys covering portions of the same area and at different times of the year have been flown in the same 30 year time span. We present previously unpublished abundance estimates, corrected to the extent feasible for known biases, for common minke whales (Balaenoptera acutorostrata), humpback whales (Megaptera novaeangliae), white-beaked dolphins (Lagenorhynchus albirostris) and harbour porpoises (Phocoena phocoena) from some or all of the 2007, 2009 and 2016 surveys. The relative abundance of most species was comparatively low in the spring and fall, and peaked June and July when all of the main surveys have been carried out. An analysis of changes in line transect density as an index of relative abundance from all surveys indicates that common minke whale abundance decreased by 75% after 2001 and has remained at a relatively low level since then. Relative abundance of humpback whales and white-beaked dolphins has increased over the period 1986-2016. We place these observed changes in context with oceanographic and ecosystem changes documented over the same period.
Dynamics of Influenza A (H5N1) virus protein sequence diversity
Authors: Abd Raman Hadia Syahirah , Tan Swan , August Joseph Thomas , Khan Asif M.
Published: May 2020

Background

Influenza A (H5N1) virus is a global concern with potential as a pandemic threat. High sequence variability of influenza A viruses is a major challenge for effective vaccine design. A continuing goal towards this is a greater understanding of influenza A (H5N1) proteome sequence diversity in the context of the immune system (antigenic diversity), the dynamics of mutation, and effective strategies to overcome the diversity for vaccine design.

Methods

Herein, we report a comprehensive study of the dynamics of H5N1 mutations by analysis of the aligned overlapping nonamer positions (1–9, 2–10, etc.) of more than 13,000 protein sequences of avian and human influenza A (H5N1) viruses, reported over at least 50 years. Entropy calculations were performed on 9,408 overlapping nonamer position of the proteome to study the diversity in the context of immune system. The nonamers represent the predominant length of the binding cores for peptides recognized by the cellular immune system. To further dissect the sequence diversity, each overlapping nonamer position was quantitatively analyzed for four patterns of sequence diversity motifs: index, major, minor and unique.

Results

Almost all of the aligned overlapping nonamer positions of each viral proteome exhibited variants (major, minor, and unique) to the predominant index sequence. Each variant motif displayed a characteristic pattern of incidence change in relation to increased total variants. The major variant exhibited a restrictive pyramidal incidence pattern, with peak incidence at 50% total variants. Post this peak incidence, the minor variants became the predominant motif for majority of the positions. Unique variants, each sequence observed only once, were present at nearly all of the nonamer positions. The diversity motifs (index and variants) demonstrated complex inter-relationships, with motif switching being a common phenomenon. Additionally, 25 highly conserved sequences were identified to be shared across viruses of both hosts, with half conserved to several other influenza A subtypes.

Discussion

The presence of distinct sequences (nonatypes) at nearly all nonamer positions represents a large repertoire of reported viral variants in the proteome, which influence the variability dynamics of the viral population. This work elucidated and provided important insights on the components that make up the viral diversity, delineating inherent patterns in the organization of sequence changes that function in the viral fitness-selection. Additionally, it provides a catalogue of all the mutational changes involved in the dynamics of H5N1 viral diversity for both avian and human host populations. This work provides data relevant for the design of prophylactics and therapeutics that overcome the diversity of the virus, and can aid in the surveillance of existing and future strains of influenza viruses.
Future sea-level rise drives rocky intertidal habitat loss and benthic community change
Authors: Kaplanis Nikolas J. , Edwards Clinton B. , Eynaud Yoan , Smith Jennifer E.
Published: May 2020

The impacts of sea-level rise (SLR) are likely to be the greatest for ecosystems that exist at the land-sea interface, where small changes in sea-level could result in drastic changes in habitat availability. Rocky intertidal ecosystems possess a number of characteristics which make them highly vulnerable to changes in sea-level, yet our understanding of potential community-scale responses to future SLR scenarios is limited. Combining remote-sensing with in-situ large-area imaging, we quantified habitat extent and characterized the biological community at two rocky intertidal study locations in California, USA. We then used a model-based approach to estimate how a range of SLR scenarios would affect total habitat area, areal extent of dominant benthic space occupiers, and numerical abundance of invertebrates. Our results suggest that SLR will reduce total available rocky intertidal habitat area at our study locations, leading to an overall decrease in areal extent of dominant benthic space occupiers, and a reduction in invertebrate abundances. As large-scale environmental changes, such as SLR, accelerate in the next century, more extensive spatially explicit monitoring at ecologically relevant scales will be needed to visualize and quantify their impacts to biological systems.
Disease Awareness and Treatment Experience of Patients with Chronic Obstructive Pulmonary Disease
Authors: Noh Hyun Jung , Kim Su Hyun , Joung Woo Joung
Published: May 2020

Purpose: The purpose of this study was to explore patients’ awareness and treatment experiences with Chronic Obstructive Pulmonary Disease (COPD) through in-depth interviews. The objective was to develop data to support patients in the successful management of their illness. Methods: Purposeful sampling was used to collect information-rich cases and participants were recruited at a university hospital in Daegu, South Korea. Data collection was done through face to face in-depth individual interviews with 10 patients with COPD from November 2016 to December 2018. Interview began with open-ended questions and each interview lasted on average one hour. All interviews were audio-taped and transcribed verbatim and transcripts were analyzed using qualitative thematic analysis. The findings were verified by the participants. Results: Four themes emerged from data analysis: ‘Feeling like the disease is not my disease,’ ‘Terminology spills like a flood,’ ‘Negligent daily disease-management with relief,’ and ‘Relying on health professionals and family members hoping for healing’. Conclusion: Participants do not have a clear understanding of their illness nor feel that they are principal agents of their health and illness for treatment and disease management; instead, they depend mainly on their family members and doctors. The findings elucidated the need for increasing patients’ awareness of the illness. Nurses should develop educational support programs to help COPD patients improve their awareness of their illness and successfully manage their treatment.
The Influence of Awareness regarding Particulate Matter, Perceived Respiratory Symptoms, and Physical Activities on Health Promotion Behavior of Elementary School Children
Authors: Park Hyoung Sook , Kim Myoung Soo , Kim Sang Hee , Ma Ryewon , Kim Myo Sung
Published: May 2020

Purpose: The purpose of this study was to identify the influence of awareness regarding particulate matter, perceived respiratory symptoms, and physical activities on health promotion behavior in elementary school children. Methods: Data were collected from 639 4th~6th grades students from 8 elementary schools in Busan and analyzed using independent t-test and ANOVA, Pearson correlation coefficients and multiple regression analysis. Results: The average for awareness regarding particulate matter was 29.84±5.63, for perceived respiratory symptoms, 0.66±0.95, and for health promotion behavior, 7.85±1.76. The mean amount of time the students spent in sleeping or sitting on an easy chair and/or activity while sitting were 10.71±3.04 and 6.60±2.84 hours a day. Factors influencing health promotion behavior in elementary school children were being a girl (β=.09, p=.015), in 4th grade (β=-.09, p=.025), residence in Busanjingu (β=-.10, p=.005), residence in Bukgu (β=-.12, p=.001), more than 10 years residence period (β=-.09, p=.020) and awareness regarding particulate matter (β=.42, p<.001). The explanation power of these variables was 23% (F=22.21, p<.001). Conclusion: It is recommended that for health education programs, gender, grade, length of residence and area’s air pollution level be considered and education program including guideline for particulate matter be provided continuously to elementary students to increase their level of awareness regarding particulate matter and proper physical activity.
Seed Priming Methods: Application in Field Crops and Future Perspectives
Authors: Rhaman Mohammad Saidur , Rauf Farjana , Tania Shaila Shermin , Khatun Mousumi
Published: May 2020

To reach in good plant stand, the life cycle of plants is faced with different critical stages such as uneven seed germination, poor and early seedling growth which ultimately results in low crop yield. It is well known that seed priming enhances germination, reduces seedling emergence time, and improves yield and yield contributing characters of plants. Seed priming is a physiological technique of seed hydration and drying to improve the metabolic process prior to germination to fasten the germination, seedling growth, and crop yield under normal, as well as different biotic and abiotic stress conditions. Many researchers have done a lot of research on seed priming in field crops to enhance the final yield. However, different priming methods and their application in field crops are poorly described. Therefore, this review paper discusses seed priming and its different methods and their application in field crops as well as future perspectives of seed priming.
Phytochemical and Anti-epileptic Studies of Ethanol Extract of Boswellia dalzielii (Frankincense Tree) Stem Bark
Authors: Medugu Asinamai Ndai , Yakubu James , Medugu Usiju Ndai , Marte Hussaini Isa , Tata Fave Yohanna , Balami Victor Musa
Published: May 2020

Aim: This research work aimed to establish scientific basis for the use of Boswellia dalzielli stem bark, in traditional medicine as anti-epileptic medication.

Methodology: The fresh stem bark of Boswellia dalzielii was extracted using absolute ethanol and screened for phytochemicals. Acute toxicity study was carried out using Lorke’s method and the antiepileptic activity was evaluated using maximal electroshock induced seizure test in day-old broiler chicks and pentylenetetrazole (PTZ) using Wistar strain mice.

Results: Phytochemical screening of ethanol extract of B. dalzielii stem bark revealed that the presence of saponins, tannins, flavonoids and steroids/terpenoides. The intrapertoneal median lethal dose value (LD50) of BDE in mice was 2592.3 mg/kg, indicating the stem bark extract is relatively safe. The extract at the dose of 500 mg/kg body weight protected 40% of animals against PTZ-induced convulsion and also protected 20% of chicks against Tonic Hindlimb Extension (THLE) phase of the Maximal Electroshock Test (MEST) significantly (p<0.05).

Conclusion: The antiepileptic investigation suggests that ethanol extract of B. dalzielii stem bark has antiepileptic activity.
Trend and Variability Analysis of Rainfall and Extreme Temperatures in Burundi
Authors: Niyongendako Marc , Lawin Agnidé Emmanuel , Manirakiza Célestin , Lamboni Batablinlè
Published: May 2020

This study investigated the variability and trend of rainfall and extreme temperatures over three eastern and northeastern regions of Burundi during the period 1980-2015. Data used were collected from seven stations belonging to the geographical institute of Burundi. Annual and seasonal variability are assessed using standardized anomaly, coefficient of variance and precipitation concentration index. In addition, non parametric statistic tests Mann Kendall and Sen’s slope estimator are used to detect trends in rainfall, maximum and minimum temperatures. The results reveal a high monthly and inter-annual variability of rainfall whereas the temperature does not show high fluctuation at monthly scale. The northern region presents the lowest amount of rainfall for the first rainfall season (October-January) when drought is frequently observed. No significant rainfall trend detected over all regions at seasonal and annual scales whereas significant increasing trend was observed for both maximum and minimum temperatures over all regions. The spatial distribution of rainfall and extreme temperatures displays also a wide variation across the region depending on topography of the study area.
Role of Non-cultivated Flowering Plants in Conservation of Pollinators
Authors: . Zameeroddin , Belavadi V. V.
Published: May 2020

A study was conducted to emphasize the importance of non-cultivated plants/weeds in North Bangalore, Karnataka from October 2014 to March 2015 in three locations. The pollinators were collected using sweep net method on cultivated and non-cultivated flowering plants. A total of 22 non-cultivated plant species and 11 cultivated plant species were observed on which 85 and 56 pollinator species were collected respectively belonging to the four families (Apidae, Halictidae, Megachilidae and Scoliidae) of Hymenoptera and two families (Syrphidae and Bombyliidae) of Diptera. It is found that association of pollinators were more towards non-cultivated plants than cultivated plants. Among cultivated flowering plants, Ocimum americanum was highly attractive followed by Field bean and Lavandula angustifolia. Among non-cultivated flowering plants, Alternanthera sessilis was highly attractive on which majority were Dipterans followed by Leucas aspera and Hyptis suaveolens indicating the importance of non-cultivated flowering plants/weeds in conservation of pollinators.
Phytochemical Study and Antioxidant Properties of Aqueous Extracts of Murraya paniculata Leaf
Authors: Monir Tania Sabnam Binta , Afroz Sadia , Jahan Ishrat , Hossain Tanvir
Published: May 2020

Aims: To investigate the chemical groups present, total phenolic compound, total flavonoid and to evaluate the possible antioxidant activity of aqueous extracts of Murraya paniculata leaf.

Place and Duration of Study: Department of Applied Chemistry and Chemical Engineering Department, Noakhali Science and Technology University, Bangladesh, in 2017

Methodology: The dry leaves were boiled and extracted with water. The extracts were concentrated and then investigated for their total phenolic compound, total flavonoid, evaluated the antioxidant activity. The preliminary screening of the various extracts was carried out using standard methods. Total phenolic content (TPC) was determined by the modified Folin-Ciocalteu method, total antioxidant capacity (TAC) and total flavonoid content were measured according to the Phosphomolybdate-method and Dowd-method respectively.

Results: The aqueous extract showed good antioxidant activity with good phenolic and flavonoid contents (400±0.44 mg ascorbic acid equivalent/g dried weight, 263±0.62 mg gallic acid equivalent/g dried weight, 63±0.19 mg quercetin equivalent/g dried weight respectively).

Conclusion: The research work revealed the presence of various bioactive phytochemical compounds which show the medicinal importance of leaves Murraya paniculata through a facile extracting method.
Steady states of general multi‐enzyme networks and their associated properties. Computational approaches
Authors: Burns J.A.
Published: July 2002

The program has been devised to be as flexible as possible to permit the user to investigate the effects of changing the concentration or kinetic properties of an individual enzyme. Alternatively, the concentrations of enzymes required to maintain a given flux may be computed. The program will deal with a network of up to about 30 enzymes.
Action du dibutyryl 3′5′‐AMP cyclique sur la lipogenese et la neoglucogenese chez la souris vivante
Authors: Rous S. , Luthi L. , Rivier F.
Published: July 2002

N6‐2′‐O‐dibutyryl cyclic AMP stimulates glycogenolysis and inhibits fatty acid synthesis in rat liver in vivo but has little effect on gluconeogenesis. In adipose tissue: it enhances lipogenesis and glycogenesis. These last effects can be explained by an increase of insulin release.
Reactivity of carboxyl groups in modified proteins
Authors: Frater R.
Published: July 2002

The reactivities of carboxyl groups to carbodiimides in non‐reduced, S‐carboxymethyl, and S‐cyanoethyl proteins have been compared. When disulphide bonds are split, a decrease in reactivity was found, relatively minor in the S‐carboxymethyl derivative and almost complete loss of reactivities in the S‐cyanoethyl derivative.
Mise en evidence d'un recepteur d'UDP‐glucose dans les membranes microsomiques des hepatocytes de rat
Authors: Frot-Coutaz J. , Berthillier G. , Got R.
Published: July 2002

Rat liver microsomal membranes have been shown to contain a biosynthetic pathway of UDP‐glucose. In addition, they are able to bind UDP‐glucose in a reversible manner. As UDP‐glucose is also metabolized in these membranes, the study of the binding has been performed with a microsomal Triton X 100 extract. This reversible binding depends on pH (maximum at pH 8.1) and manganous ions, and disappears at pH 6.5. It exhibits a high affinity (Kdiss = 3 μM), and a narrow specifity for UDP‐glucose. Proteolytic digestion inhibits the binding up to 90%, showing that the UDP‐glucose receptor has a proteic nature. These binding characteristics have been also found in the membranes themselves, indicating that the detergent solubilization does not destroy the protein binding capacity.
Konformationsänderungen vor und nach DNA‐synthese verstärken zellgenetisch letale strahlenschäden
Authors: Hagemann Gerd , Mellmann Jürgen
Published: July 2002

Chinese hamster ovary fibroblasts were synchronized by mitotic selection and showed cytogenetic lethally acting radiation damages, which depended on age at irradiation time. The development of cell cultures was followed by counting of the killed cells in the 3rd daughter generation of the irradiated ones and by evaluation of the colony size spectra 73.5 h after innoculation. At a dose of 300 rads two narrow but high peaks of radiation sensitivity were induced, which appeared at the beginning and at the end of the S‐phase of the cell cycle and therefore are reduced to conformational changes of the DNA. Consequently the DNA‐superstructures linking pieces of the nucleoprotein‐fibre during fastening to, and detaching from, the nuclear membrane are assumed to be the loci of the increased radiation sensitivity.
Etude de la structure de membranes chloroplastiques isolées de la souche sauvage et d'un mutant sans activité du photosystème I de Chlamydomonas reinhardtii
Authors: Picaud Alain , Acker Suzanne
Published: July 2002

It is possible, therefore, to correlate the absence of photosystem I activity with the lack of protein‐pigment complex I (mol. wt = 70 000) and, also, with the lack of Chl a
690 form.
Mechanism of chain initiation by dextransucrase
Authors: Parnaik Veena K. , Mayer Robert M.
Published: July 2002

Dextran was synthesized using dextransucrase from Streptococus sanguis 10558 and (F)‐[14C]sucrose as substrate to test the possibility that sucrose may be the initial acceptor for glucose. If sucrose is the initial acceptor, then dextran chains should have [14C] fructose in a terminal ‘sucrose’ linkage which can be cleaved under mild conditions. Although incorporation of [14C]fructose into dextran was observed, the label was not released by mild hydrolysis, indicating that sucrose is not the initiator for dextran synthesis. Incorporation of [14C]fructose into dextran might represent its ability to act as an acceptor, as suggested by the isolation of leucrose as a by‐product in the reaction.
Regulation of hepatic carnitine palmitoyltransferase activity during the foetal‐neonatal transition
Authors: David Saggerson E. , Carpenter Carol A.
Published: July 2002

Overt carnitine palmitoyl transferase (CPT1) activity was measured in liver mitochondria from foetal rats (21 days gestation) and from neonatal rats (1 day post‐partum). Birth was accompanied by a 6‐fold increase in CPT1 activity, a 14‐fold decrease in sensitivity to inhibition by malonyl CoA and an increase in the n
H and the S
0.5 from palmitoyl CoA. The activity of latent enzyme (CPT2) was unaffected at birth.
Ecdysone and 20 hydroxyecdysone: new hormones for the human parasite Schistosoma mansoni
Authors: Nirde Ph. , Torpier G. , De Reggi M.L. , Capron A.
Published: July 2002

The insect moulting hormones, ecdysone and 20 hydroxyecdysone, were detected by the combined use of radioimmunoassay and high performance liquid chromatography in the human parasite Schistosoma mansoni. On day 11 after infection only the ecdysone form is present, but, on day 40 after infection the ratio between ecdysone and 20 hydroxyecdysone changes with anatomic localization of the adult worms in mammalian host. In the eggs, the ratio of these two hormones is identical to the ratio found in sexually mature worms located in mesenteric veins. These data demonstrate for the first time that S. mansoni synthesizes the steroid hormones ecdysone and 20 OH ecdysone which are potent molecules in stimulating growth and vitello‐genesis of this gonochoric trematode.
Are plant genes different?
Authors: Lycett Grantly W. , Delauney Ashton J. , Croy Ronald R.D.
Published: July 2002

The mRNAs from animal systems are now known to have some conserved sequences in common, and a characteristic codon usage. Very few plant genes or cDNAs have been sequenced so far and it has not been possible to say therefore whether they share these characteristics as well. This paper presents sequence data from cDNAs coding for the major storage proteins of pea and compares these plant data with the concensus features of animal genes. The codon usage of plants is different from that of animals and more variability occurs in the conserved sequences in the 3′ untranslated region.
Interaction of AMP with cytosolic apo‐aspartate aminotransferase
Authors: Di Donato A. , Fiore R. , Garzillo A.M. , Marino G.
Published: July 2002

Interaction of cytosolic apo‐aspartate aminotransferase with AMP has been studied under equilibrium conditions: e.g., equilibrium dialysis and spectrophotometric titration. Results show that a 1:1 stoichiometric complex AMP—apo‐aspartate aminotransferase monomer is formed. The calculated dissociation constants with the two different experimental techniques are 40.4 × 10−6 M−1 and 31.4 × 10−6 M−1, respectively. These findings substantiate a previous hypothesis of control of the reconstitution of cytosolic apo‐aspartate aminotransferases exerted by AMP.
Structure of DNA in metaphase chromosomes of mouse fibroblasts
Authors: Belyaev N.D. , Budker V.G. , Dubrovskaya V.A. , Matveeva N.M.
Published: July 2002

We show tht N‐1 in adenine of chromosomal DNA is methylated by treatment of metaphase chromosomes with dimethylsulphate while this is not the case in chromatin. The data on methylation are consistent with those obtained from the experiments with S1‐nuclease treatment of chromatin and chromosomes. This suggests a disarrangement of DNA secondary structure in the metaphase chromosomes.
Caldesmon, a calmodulin‐binding, F actin‐interacting protein, is present in aorta, uterus and platelets
Authors: Kakiuchi Ritsu , Inui Makoto , Morimoto Kouichi , Kanda Keiko , Sobue Kenji , Kakiuchi Shiro
Published: July 2002

Caldesmon, a protein originally found in chicken gizzard, was concluded also to be present in bovine aorta, uterus, and human platelets by demonstration of a protein with the following properties: (a) Ca2+‐dependent calmodulin‐binding; (b) binding to F actin in such way that the binding was broken on Ca2+‐dependent binding of calmodulin; (c) cross‐reactivity in immune blotting procedures with affinity‐purified antibody against gizzard caldesmon; (d) similar subunit M
r‐values on SDS‐gel to those of gizzard caldesmon. Like gizzard caldesmon, platelet caldesmon was composed of two polypeptide bands of M
r 150000 and 147000, but caldesmon in aorta and uterus gave a single band of M
r 150000. A polypeptide of M
r 165000 that was immunologically distinct from caldesmon but, like caldesmon, bound to calmodulin and F actin in a flip‐flop fashion, was also demonstrated in aorta and uterus.
Organization of ribosomal DNA in yellow lupine (Lupinus luteus) and sequence of the 5.8 S RNA gene
Authors: Rafalski Jan Antoni , Wiewiórowski Maciej , Söll Dieter
Published: July 2002

The large ribosomal repeat of the Lupinus luteus genome is 8.8 kb in length as revealed by Southern blotting and hybridization to 5.8 S rRNA and cloned rDNA fragments of L. luteus and Schizosaccharomyces pombe. It codes for 18 S,5.8 S and 28 S rRNAs. A cloned 3.7 kb EcoR1 subfragment of the rDNA repeat, coding for 5.8 S rRNA and a large portion of the 28 S rRNA, has been sequenced in the region of 5.8 rRNA gene. The predicted rRNA sequence is homologous to broad bean 5.8 S rRNA and can be arranged in the generalized model of 5.8 S RNA secondary structure.
An anti‐acetylcholine receptor monoclonal antibody cross‐reacts with phosvitin
Authors: Pizzighella Sergio , Gordon Adrienne S. , Souroujon Miry C. , Mochly-Rosen Daria , Sharp Ayala , Fuchs Sara
Published: July 2002

Rabbit and mouse anti‐Torpedo acetylcholine receptor antibodies cross‐reacted partially with the highly phosphorylated protein, phosvitin. We have selected an anti‐Torpedo acetylcholine receptor monoclonal antibody which binds specifically to phosvitin; this binding is inhibited by acetylcholine receptor. These findings suggest that a phosphorylated amino acid residue may be a part of the determinant on the acetylcholine receptor recognized by this monoclonal antibody.
Isolation and characterization of 15‐hydroxylated metabolites of leukotriene C4
Authors: Örning Lars , Hammarström Sven
Published: July 2002

A polar metabolite of leukotriene C4 was formed by sequential conversions with soybean lipoxygenase I and liver peroxidase. The structure of this product was found to be 5(S), 15(S)‐dihydroxy‐6(R)‐S‐glutathionyl‐7,9,13‐trans‐11‐cis‐eicosatetraenoic acid (15‐hydroxy‐Δ13‐trans‐leukotriene C3). The HPLC behaviour, the molar extinction coefficient and the biological activity of the metabolite are reported. Preliminary evidence suggests that this product is formed by mammalian tissues.
Purification of a pituitary polypeptide that stimulates the replication of adipocyte precursors in culture
Authors: Lau David C.W. , Roncari Daniel A.K. , Yip Dominic K. , Kindler Sara , Nilsen Sandra G.E.
Published: July 2002

A bovine anterior pituitary polypeptide that stimulates the replication of rat and human adipocyte precursors has been purified. It M
r is 44 000–53 000 and its isoelectric point is 9.8–10.3. While pituitary basic fibroblast growth factor is equally mitogenic on adipocyte precursors and skin fibroblasts, the polypeptide described here is selectively more active on the precursors. We postulate that this adipocyte growth factor plays a physiological role by modulating the number of adipocyte precursors.
Adenylate cyclase inhibition by hormones
Authors: Bockaert Joel , Sebben-Perez Michele
Published: July 2002

In washed anterior pituitary membranes, there is enough GTP to occupy N
s and therefore to obtain activation of adenylate cyclase by vasointestinal peptide. GTP concentrations needed to obtain adenylate cyclase inhibition by dopamine (above 5 × 10− M) stimulate the adenylate cyclase. The dopamine efect is a blockade of this stimulation. We propose that at least in this system, N
i does not inhibit but stimulates the adenylate cyclase and that inhibitory hormones block this stimulation. We also demonstrate in several adenylate cyclase systems that hormones produced adenylate cyclase inhibition by lowering their Mg affinity A general model for adenylate cyclase activation and inhibition is proposed.
Amplification of the rudimentary gene in a PALA‐resistant Drosophila cell line
Authors: Giorgi Dominique , Laval Monique , Pardo Daniel
Published: July 2002

In Drosophila melanogaster the rudimentary locus encodes for a multifunctional protein catalyzing the first three enzymatic activities of pyrimidine biosynthesis. Cell lines were selected which were resistant to PALA (N‐(phosphonoacetyl)‐L‐aspartate), a specific inhibitor of aspartate transcarbamylase, the second enzyme of this pathway. In a cell line where the enzyme production is increased 5 times, Southern blot analyses show that the rudimentary gene and surrounding regions are amplified about 5 times. In this case gene amplification could therefore account for the observed enzyme overproduction.
Effects of phenothiazines on low density lipoprotein metabolism in cultured human fibroblasts
Authors: Maziere J.C. , Maziere C. , Gardette J. , Routier J.D. , Wolf C. , Rainteau D. , Polonovski J.
Published: July 2002

Treatment of cultured human fibroblasts with trifluoperazine or chlorpromazine resulted in a biphasic effect on low density lipoprotein (LDL) catabolism, depending upon the dose. At up to 10−5 M, a marked increase in LDL binding, internalization and degradation was observed. This phenomenon took place within the first hours of incubation with the drugs, suggesting a direct effect on cell membrane physical characteristics, probably related to the lipophilic properties of phenothiazines. Concentrations above 2 × 10−5 M resulted in a relative decrease in LDL binding and internalization, and in a dramatic decrease in LDL degradation, which may be related to an inhibition of calmodulin‐dependent processes.
Evidence for the presence of N2‐(1,3‐dicarboxypropyl)‐L‐amino acids in crown‐gall tumors induced by Agrobacterium tumefaciens strains 181 and EU6
Authors: Chang Chi-Cheng , Chen Chong-Maw
Published: July 2002

Using crown‐gall tumors induced by Agrobacterium tumefaciens strains 181 and EU6 several unusual compounds have been isolated in a single fraction. Physicochemical analysis of the compounds in this fraction showed that they are N
2‐(1,3‐dicarboxypropyl)‐L‐amino acids derived from neutral and acidic amino acids. Asparagine and glutamine derivatives (asparaginopine and glutaminopine) are the main components. Synthesis of asparaginopine from asparagine, α‐ketoglutarate and NADPH, and degradation of asparaginopine to asparagine have also been demonstrated using enzyme prepared from Pinto bean strain 181 tumor.
Cellular RNA is not degraded in interferon‐treated HeLa cells after poliovirus infection
Authors: Muñoz Alberto , Harvey Robert , Carrasco Luis
Published: July 2002

A drastic inhibition of protein synthesis occurs in HeLa cells treated with human lymphoblastoid interferon and infected with poliovirus. At the time when this inhibition has been established no degradation of 32P‐labelled ribosomal RNA can be detected. Isolation of the mRNAs from poliovirus‐infected cells plus or minus interferon treatment, followed by translation in a reticulocyte lysate indicates that cellular mRNAs remain active. These results suggest that gross degradation of cellular RNA does not occur in interferon‐treated poliovirus‐infected HeLa cells and that a non‐specific nuclease induced by 2′–5′ A is not responsible for the inhibition of protein synthesis observed.
The effect of dichloroacetate and hydroxypyruvate on the entry of 14C from [1‐14C]alanine into urea in rat hepatocytes
Authors: Hems Reginald
Published: July 2002

Entry of metabolic 14CO2 into urea is shown to be decreased by dichloroacetate although the production of 14CO2 is stimulated 2‐fold. Hydroxypyruvate, a product of dichloroacetate metabolism, increases the incorporation of metabolic 14CO2 into urea. It is proposed that these effects result from changes in the cytoplasmic‐mitochondrial pH gradient.
Detection of inactive precursors of β‐glucanases in Saccharomyces cerevisiae
Authors: Hernandez Luis M. , Olivero Isabel , Larriba German
Published: July 2002

Accumulation and secretion of β‐glucanases have been studied in vivo by using a thermosensitive secretory mutant of Saccharomyces cerevisiae blocked at the endoplasmic reticulum level (sec 18‐1). When incubated at the restrictive temperature no accumulation of active glucanases was observed. Following a shift to permissive conditions in the presence of cycloheximide a rise in the internal activity took place. The increase in total glucanase activity was partially due to the activation of an exo‐glucanase that hydrolyzes PNPG. It is concluded that glucanases are synthesized in inactive precursor forms and are converted to the active forms in their secretory pathway.
Neurotransmitter‐caused increase in [3H]inositol incorporation into phosphatidylinositol de novo synthesis vs exchange
Authors: Lupu Monica , Oron Yoram
Published: July 2002

[3H]inositol and 32Pi were simultaneously incorporated into rat parotid phosphatidylinositol. The ratio of [3H]/32Pi incorporation dropped dramatically following stimulation with muscarinic or α‐adrenergic agonists and returned to control values following the addition of appropriate antagonists. The drop in [3H]/32Pi ratio can be explained by a rapid increase in de‐ novo synthesis of phosphatidylinositol following its receptor‐mediated breakdown. The change in this ratio also provided evidence for the existence of CDP‐DG + inositol ⇄ phosphatidylinositol exchange reaction in the intact tissue.
Fate of newly synthesized histones in G1 and G0 cells
Authors: Wu Roy S. , Perry Linda J. , Bonner William M.
Published: July 2002

We have shown that quiescent cells as well as those in the G1 phase of the cell cycle synthesize histones at a reduced but significant rate. Now, we show that the histones synthesized during G0 and G1 are stably incorporated into nuclei soon after synthesis. Micrococcal nuclease digestion of nuclei isolated from cells in G0 and G1 revealed that the specific histone variants synthesized in these different physiological states are found associated with DNA as nucleosomes. Nucleosomes were separated by polyacrylamide gel electrophoresis in a reducing buffer so that histone spot morphology, particularly that of the H3s was improved.
Is transcription of higher plant chloroplast ribosomal operons regulated by premature termination?
Authors: Briat Jean François , Dron Michel , Mache Régis
Published: July 2002

Three stem‐loop structures (H1, H2, H3) can be formed in the leader transcript of the chloroplast rDNA of spinach, tobacco and maize. H2 and H3 partially overlap and cannot exist simultaneously. These potential hairpins lead us to postulate that higher plant chloroplast rDNA is regulated by premature termination. This mechanism could be controlled by the presence or absence of a ribosome translating an hypothetical leader peptide encoded in the rDNA leader sequence of these 3 higher plants.
A compact three‐dimensional crystal form of the large ribosomal subunit from Bacillus stearothermophilus
Authors: Yonath A. , Piefke J. , Müssig J. , Gewitz H.-S. , Wittmann H.G.
Published: July 2002

A new form of well‐ordered three‐dimensional crystals of intact 50 S ribosomal subunits from Bacillus stearothermophilus have been obtained. Electron micrographs of positively stained sections of these crystals revealed that the ribosomal particles are packed closely. The cell parameters have been determined. Representative electron micrographs and their computed contoured filtered images are shown.
Crystallographic data for horse heart ferritin
Authors: Bolognesi Martino , Gatti Giuseppina , Levi Sonia , Gabri Elena , Arosio Paolo
Published: July 2002

Horse heart and spleen feritins were subjected to crystallization experiments with polyethylene glycols. Crystals suitable for preliminary X‐ray diffraction experiments were obtained from polyethylene glycol (6000 average M
r), under controlled conditions of pH and ionic strength. Heart ferritin crystallizes in space group F432, with unit cell edges a = b = c = 183 Å, with a single subunit in the crystallographic asymmetric unit.
Effects of proteolysis on the actions of monovalent cations and 1‐O‐octadecyl‐2‐O‐acetyl‐sn‐glyceryl‐3‐phosphorylcholine on platelet adenylate cyclase
Authors: Williams Kimberley A. , Vanderwel Marianne , Haslam Richard J.
Published: July 2002

NaCl stimulated the adenylate cyclase activities of human and rabbit platelet particulate fractions prepared in the presence of ethylene glycol bis(β‐aminoethyl ether)‐N,N,N′,N′‐tetraacetate, but inhibited the activities of particulate fractions proteolysed by endogenous Ca2+‐activated protease or treatment with α‐chymotrypsin. Studies with other monovalent cations showed that LiCl had weak effects similar to those of NaCl, whereas KCl inhibited the enzyme in both proteolysed and non‐proteolysed preparations. The results suggest that NaCl exerts stimulatory and inhibitory effects through different sites. NaCl potentiated and proteolysis greatly reduced the inhibition of platelet adenylate cyclase by 1‐O‐octadecyl‐2‐O‐acetyl‐sn‐glyceryl‐3‐phosphorylcholine (platelet‐activating factor).
A new reaction useful for chemical cross‐linking between nucleic acids and proteins
Authors: Nitta Noriko , Kuge Osamu , Yui Seiko , Tsugawa Akiko , Negishi Kazuo , Hayatsu Hikoya
Published: July 2002

Cytosine in nucleic acids can be converted into N
4‐aminocytosine by treatment with a mixture of hydrazine and bisulfite. The hydrazino group thus formed at position 4 of the pyrimidine ring can be linked to a sulhydryl group in proteins by the use of bromopyruvate as a linker. Successful use of this scheme of chemical cross‐linking between nucleic acid and protein was demonstrated in the linking of poly(C) with glutathione, and of RNA with protein in the E. coli 30 S ribosomal subunit.
An efficient method for labelling antibodies with 111In
Authors: Buckley R.G. , Searle F.
Published: July 2002

Using a new method, rabbit IgG and a monoclonal antibody have been conjugated with the chelating agent DTPA. This was accomplished with reaction conditions that should entail lower antibody damage than existing methods. Gel filtration of the 111In‐labelled antibody conjugate indicated minimal damage to the antibody and radioimmunoassay showed no significant change in its immunological activity.
The amino acid sequence of rabbit skeletal muscle calmodulin
Authors: Nairn Angus C. , Grand Roger J.A , Victor Perry S.
Published: July 2002

The amino acid sequence of calmodulin which can be extracted from rabbit skeletal muscle with low ionic strength buffer and presumably activates myosin light chain kinase has been determined. It is a single polypeptide chain of 148 residues with a blocked N terminus. The sequence of the N terminal tripeptide and residues 98 and 99 were not determined unequivocally nor were the amide assignments of residues 48, 50, 58 and 60. The protein is otherwise identical with the subunit of phosphorylase kinase and bovine uterus calmodulin and very similar to all other mammalian calmodulins.
Nucleotide sequence of the Galleria mellonella nuclear polyhedrosis virus origin of DNA replication
Authors: Blinov V.M. , Gutorov V.V. , Holodilov N.G. , Iljichev A.A. , Karginov V.A. , Mikrjukov N.N. , Mordvinov V.A. , Nikonov I.V. , Petrov N.A. , Urmanov I.H. , Vasilenko S.K.
Published: July 2002

The initiation sites of the Galleria mellonella L. nuclear polyhedrosis virus (G.m. NPV) DNA replication were revealed. For this purpose SCLd 135 cells permitting the G.m. NPV productive reproduction were transformed by the recombinant plasmids containing the viral genome individual fragments in pRSF 2124 and pBR 322 vectors. It was revealed that 2 of the 32 recombinant plasmids can autonomously replicate in the eucaryotic cells. According to the Maxam‐Gilbert method the DNA G.m. NPV fragment (1300 bp) primary structure of pHBR plasmid was determined. The structure analysis revealed the typical regulator signals as in the replicons. The possible regulation mechanisms of the DNA G.m. NPV synthesis initiation was supposed.
The Mg2+ requirements of nonactivated and activated rat liver phosphorylase kinase
Authors: Chrisman Ted D. , Sobo Gwenn E. , Exton John H.
Published: July 2002

Incubation of rat liver phosphorylase kinase in the presence of MgATP results in a time‐dependent increase in activity, i.e., activation. Determination of the magnitude of activation depends, in large part, on the relative concentrations of Mg2+ and ATP used in the phosphorylase kinase activity assay, such that as the Mg2+ to ATP ratio increases less activation is detectable. Prior to activation, maximal activity of nonactivated phosphorylase kinase requires a 2–3 fold molar excess of Mg2+ (i.e., free Mg2+) over ATP. MgATP‐dependent activation of the enzyme results in an alteration in the free Mg2+ requirement such that the activity of the activated enzyme is sharply inhibited by the free cation. Inhibition by free Mg2+ of the activated enzyme is rapidly reversed by removal of free Mg2+ but is not affected by addition of Ca2+. Both nonactivated and activated forms of enzyme appear to be inhibited by free ATP4–. The results show that the use of high concentrations of free Mg2+ in the phosphorylase kinase activity assay can blunt or completely obscure changes in enzyme activity following activation of the enzyme.
Raman spectroscopic analysis of the secondary structure in Panulirus interruptus hemocyanin
Authors: Williams Robert W. , Hendrickson Wayne A.
Published: July 2002

The secondary structure content of Panulirus interruptus hemocyanin crystals is estimated to be 29±5% helix and 42±4% ß‐strand. These estimates are obtained from an analysis of the Raman amide I spectrum. This report constitutes a test of this method of analyzing Raman spectra since the X‐ray structure of P. interruptus, which is unknown to us, is under intensive study. Also, the amide I spectrum of P. interruptus in solution, at a somewhat higher pH, is significantly different from the spectrum of crystals which indicates that the secondary structure content may be different in the solution sample.
New functions for the components of glucocorticoid receptor apparatus?
Authors: Seleznev Yu.M. , Shnyra A.A. , Medvedeva L.A.
Published: July 2002

By ammonium sulphate precipitation, phosphocellulose and DEAE—Sephacel chromatography and Sephadex G‐75 gel filtration, a factor was separated from rat liver cytosol which was shown to suppress the inhibitory effect of the steroid deoxycorticosterone (DOC) on the specific [3H]glucocorticoid binding to cytoplasmic receptors. By SDS‐polyacrylamide gel electrophoresis (SDS—PAGE) of factor‐containing fractions its M
r was suggested to be about 40000. The possible role of this factor in the regulation of glucocorticoid receptor apparatus function is discussed.
Partial purification and characterization of a soluble haemoprotein, having spectral properties similar to cytochrome a1, from anaerobically grown Escherichia coli
Authors: Baines Baldev S. , Williams Huw D. , Hubbard Julia A.M. , Poole Robert K.
Published: July 2002

‘Soluble’ fractions obtained after high‐speed differential centrifugation of extracts from ultrasonically disrupted Escherichia coli, grown anaerobically with glycerol and fumarate, contain at least two haemoproteins, distinguishable by their CO‐binding characteristics. Reduced minus oxidized spectra show a maximum at 598 nm and a shoulder to the Soret region near 440 nm, features generally attributed to ‘cytochrome a
1’. CO‐reduced minus reduced difference spectra show the more rapidly CO‐binding component to have a trough at 444 nm, also generally attributable to an a‐type cytochrome. The partially purified a
1‐like component has catalase and peroxidase activities, and lacks copper. An appropriate nomenclature for the a
1‐like haemoprotein and its similarity to catalase are discussed.
The ribosomal binding domain for the bacterial release factors RF‐1, RF‐2 and RF‐3
Authors: McCaughan Kim K. , Ward Christina D. , Trotman Clive N.A. , Tate Warren P.
Published: July 2002

The Escherichia coli ribosomal proteins, L7/L12, are dominant over L11 in modulating the binding of RF‐1 and RF‐2 to ribosomes. The elevated activity of RF‐2 on L11‐lacking ribosomes over those containing L11 is abolished by IgG against L7/L12 or by removing the L7/L12 proteins. Adding back L7/L12 restores the original phenotype. The stimulatory factor, RF‐3, is active on ribosomes depleted of L7/L12 but on those which lack L11 the stimulatory effects are less pronounced or often not seen. RF‐3 cannot restore activity with RF‐1 or RF‐2 to ribosomes lacking both these sets of proteins. The stimulatory effects of an absence of either L11 or RF‐3 on the activity of RF‐2 are not additive or synergistic.
Na,K‐dependent adenosine triphosphate phosphohydrolase: activation of the phosphatase reaction by ATP analogs
Authors: Boldyrev Alexander A. , Lopina Olga D. , Gulyaev Nikita N. , Baranova Lyudmila A. , Severin Evgeny S.
Published: July 2002

The effect of N1‐substituted analogs of ATP on the hydrolysis of umbelliferone phosphate by Na,K‐ATPase has demonstrated: (i) analogs having a negatively charged substituent (N
1‐oxy‐ or N
1‐carbo‐methoxy‐ATP) and capable of accepting H+ induce an activation similar to that of ATP; ii) N
1‐methoxy‐ATP, containing an uncharged substituent, does not affect the phosphatase reaction at low concentration and inhibits it at higher concentration. It has been assumed that ATP binding to Na,K‐ATPase induces formation of a hydrogen bond between the nitrogen atom at the first position of the purine base and appropriate amino acid of active centre, with a subsequent attachment of H+ to ATP, thus facilitating the transition of Na,K‐ATPase from the K+‐ to the Na+‐form.