bluuebunny/crossref_metadata_2025 huggingface dataset:
The "Quantum Temporal Lattice" (QTL)
Authors: - Dishana Rupani , - Vanshika Sachdeva
Published: February 2025

The Quantum Temporal Lattice (QTL) theory delves into mathematical models, philosophical implications, and potential real-world applications of advanced theories like M-theory, the holographic principle, and brane dynamics, aiming to bridge the gap between advanced physics. QTL integrates quantum vacuum fluctuations and holographic encoding to control the flow of time within a lattice allowing for localized time shifts, enabling the creation of closed timelike curves (CTCs). While speculative, the QTL aims to provide a new way to investigate spacetime manipulation and temporal phenomena, holding potential applications in theoretical physics and cosmology.
Enhancing Biometric Security with Artificial Intelligence: A Cutting-Edge Approach
Authors: - Mr. Chaitanya Jain , - Mr. Hardik Bhawani , - Mr. Aryan Saxena
Published: February 2025

Biometric security has emerged as a critical component in safeguarding digital assets, physical spaces, and personal information. This research paper provides a comprehensive review of the intersection between biometrics and artificial intelligence (AI), aiming to explore the latest advancements, challenges, and prospects in this dynamic field. The paper begins by introducing the fundamental concepts of biometrics and AI, highlighting their symbiotic relationship in enhancing security protocols. It delves into the various biometric modalities, including facial recognition, fingerprinting, iris scanning, vital sign, psychological and voice recognition, and examines how AI techniques have transformed the
accuracy and robustness of these methods. Special attention is given to the developments in deep learning algorithms, neural networks, and convolutional neural networks (CNNs), which have revolutionized biometric authentication by enabling feature extraction, pattern recognition, and anomaly detection with unprecedented precision.
Balancing Security and Scalability Implementing Zero-Trust Architectures in Azure for Insurance Platforms
Authors: - Radhakrishnan Arikrishna Perumal
Published: February 2025

The primary issue for insurance platforms running in cloud environments is to scale to meet changing demands while maintaining strong security. To overcome these obstacles, this article investigates using Zero-Trust architecture in Microsoft Azure. Only authorized users and devices interact with critical insurance data thanks to Zero-Trust principles, which strongly emphasize stringent access controls and ongoing verification. This strategy reduces the risk of breaches while enabling smooth expansion by utilizing Azure's native tools and services, such as Conditional Access and Azure Active Directory. The paper offers a paradigm for combining scalable infrastructure with security rules while adhering to legal requirements such as GDPR and HIPAA. Real-world use cases are investigated to show how well Zero-Trust designs work to reduce risks and improve operational efficiency in the insurance industry. The results emphasize combining adaptable cloud solutions with cutting-edge security frameworks to balance system performance and data safety.
Reading Meredith Talusan’s Fairest: A Queer Decolonial Critique of the U.S. Empire
Authors: Ma Ying
Published: February 2025

This essay examines Meredith Talusan’s Fairest, the first book-length memoir by and about a trans Asian woman. I argue that Talusan’s gender and sexual reconstruction is an ongoing process of accepting, negotiating, and rejecting ideas deeply rooted in the white heteropatriarchy that prevails throughout the U.S. transnational empire. I first investigate Talusan’s critique of the colonial mentality that is imposed on Filipinos, and their suggestion to resist such a sense of indigenous inferiority. Next, I explore how Talusan molded themself to blend into the masculinity-obsessed American gay culture that renders Asian men undesirable, but they ultimately realized that either passing as white or gay erased certain parts of who they really are. Last, I analyze how Talusan proposes a new direction of trans feminism that centers on woman-identification while rejecting the male privileges that they had enjoyed before gender transition. Inspired by nineteenth-century British women writers, Talusan revisits the colonial history of Filipino transgender people as victims of gender-based violence.
The Kv2.2 channel mediates the inhibition of Prostaglandin E2 on glucose-stimulated insulin secretion in pancreatic β-cells
Authors: Pan Chengfang , Liu Ying , Wang Liangya , Fan Wenyong , Ni Yunzhi , Zhang Xuefeng , Wu Di , Li Chenyang , Li Jin , Li Zhaoyang , Liu Rui , Hu Changlong
Published: February 2025

Prostaglandin E2 (PGE2) is an endogenous inhibitor of glucose-stimulated insulin secretion (GSIS) and plays an important role in pancreatic β-cell dysfunction in type 2 diabetes mellitus (T2DM). This study aimed to explore the underlying mechanism by which PGE2 inhibits GSIS. Our results showed that PGE2 inhibited Kv2.2 channels via increasing PKA activity in HEK293T cells overexpressed with Kv2.2 channels. Point mutation analysis demonstrated that S448 residue was responsible for the PKA-dependent modulation of Kv2.2. Furthermore, the inhibitory effect of PGE2 on Kv2.2 was blocked by EP2/4 receptor antagonists, while mimicked by EP2/4 receptor agonists. The immune fluorescence results showed that EP1-EP4 receptors are expressed in both mouse and human β-cells. In INS-1(832/13) β-cells, PGE2 inhibited voltage-gated potassium currents and electrical activity through EP2/4 receptors and Kv2.2 channels. Knockdown of Kv2.2 reduced the action potential firing frequency and alleviated the inhibition of PGE2 on GSIS in INS-1(832/13) β-cells. PGE2 impaired glucose tolerance in wild-type mice but did not alter glucose tolerance in Kv2.2 knockout mice. Knockout of Kv2.2 reduced electrical activity, GSIS and abrogated the inhibition of PGE2 on GSIS in mouse islets. In conclusion, we have demonstrated that PGE2 inhibits GSIS in pancreatic β-cells through the EP2/4-Kv2.2 signaling pathway. The findings highlight the significant role of Kv2.2 channels in the regulation of β-cell repetitive firing and insulin secretion, and contribute to the understanding of the molecular basis of β-cell dysfunction in diabetes.
Enhancing Data Utilization in Human Development Programmes: A Structured Programme Analytical Framework for Improved Decision-Making
Authors: Cheboi Asseneth Jerotich , Kalanda Boniface Francis
Published: February 2025

Programme data analysis, often the weakest link in the management of human development programmes, undermines the quality of programmes and delivery of results. Organizations implementing human development programmes have vast amounts of programme monitoring data collected through various data collection methods such as field monitoring visits, surveys, and interviews. Often, these data are not optimally used because of a lack of an established and institutionalized Programme Analytical Framework (PAF). In this study, the need for a structured approach for an organization implementing human development programmes to analyse programme data using a Programme Analytical Framework (PAF) has been highlighted. In the Theory of Change (ToC) which sought to articulate the key issues and pathways of change to improve programme analyses, we identified three key issues – organizational culture change, skills for analysis and an analytical framework – as the critical enablers for improved analysis in an organization. Furthermore, the paper outlines the various areas of focus for analysis to be considered when developing a Programme Analytical Framework (PAF) and the emphasis on the dissemination of analytical products with actionable insights for use in decision-making. Overall, this proposed Programme Analytical Framework (PAF) seeks to improve the analysis and use of programme data which ultimately improves the quality and delivery of results for human development programmes.
Optimizing Jasmine Flower Extraction: A Review of Modern Approaches
Authors: Ali Syed Mazar , Nidoni Uday kumar , G. S Krishna Reddy
Published: February 2025

Jasmine, renowned for its enchanting fragrance and therapeutic properties, holds significant cultural, economic, and industrial value globally. Primarily cultivated for its flowers, jasmine is widely used in perfumery, cosmetics, aromatherapy, and pharmaceuticals. Value addition, such as producing essential oils, teas, and skincare products, enhances profitability, extends shelf life, and reduces post-harvest losses. Traditional extraction methods like steam distillation (SD) and solvent extraction (SE) face limitations, including low yield, long extraction times, and degradation of heat-sensitive compounds. To overcome these challenges, innovative technologies such as supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), subcritical water extraction (SWE), pulsed electric field (PEF), and cold plasma extraction have emerged. These methods offer higher efficiency, improved yield, and reduced environmental impact. For example, SFE using supercritical CO₂ achieves superior oil yields, while MAE and UAE reduce extraction time and energy consumption. SWE eliminates organic solvents, making it a sustainable alternative, and PEF and cold plasma enhance extraction by disrupting cell membranes. Despite their advantages, challenges such as high equipment costs, scalability, and optimization of parameters remain. Future research should focus on techno-economic analysis, environmental impact assessment, and scalable industrial prototypes. By integrating these advanced technologies, the jasmine industry can achieve sustainable growth, support rural livelihoods, and meet the rising demand for natural and organic products. This review highlights advancements in jasmine processing, emphasizing the potential of innovative extraction methods to revolutionize the industry while preserving its aromatic and therapeutic qualities.
Analysis of Climate Change Adaptation Strategies and Constraints Faced by Cocoa Farmers in Cross River State, Nigeria
Authors: O. O. Osim, , F.O. Ogebe, , J. A. C. Ezihe,
Published: February 2025

This study analyzed the climate adaptation strategies and constraints faced by cocoa farmers in Cross River State, Nigeria, using the factor analysis. Primary data was collected using structured questionnaires to examine cocoa farmers' adaptation strategies for mitigating climate change effects on cocoa production and the challenges they face in adopting these strategies. This study identifies three major climate change adaptation strategies used by cocoa farmers, and these strategies explained 72.4% of the variance in the dataset. Factor 1 (crop management) includes practices like changing planting dates, drought-resistant varieties, and crop diversification. Factor 2 (water and soil conservation) focuses on irrigation, mulching, shade trees, and contour farming. Factor 3 (institutional and financial strategies) highlights training programs, weather forecasts, credit access, and collaboration. These strategies demostrated farmers' proactive efforts to manage climate risks through a combination of on-farm practices, resource management, and external support systems. The study also identifies key constraints faced by cocoa farmers in adapting to climate change using factor analysis. Two main factors explain 94.3% of the observed variance in adaptation constraints. Factor 1, (representing institutional, economic, and resource constraints), includes issues like price volatility, lack of mechanization, poor infrastructure, and limited access to technology, which hinder adaptation efforts. Factor 2 (social and organizational challenges), highlights challenges such as resistance to change, lack of training, ineffective cooperatives, and financial constraints. These barriers reduce productivity, limit resilience, and stall adaptation. The study calls for improved infrastructure, government support, cooperatives, and training to enhance farmers' capacity for climate adaptation.
Evaluating Biochar as a Potting Mixture Substitute: Impacts on Coffee Seedling Growth and Soil Properties
Authors: Gopinandhan T. N. , Channabasamma B.B.
Published: February 2025

Biochar is a carbon rich product derived from agricultural waste biomasses through pyrolysis widely reported to enhance the soil fertility. Coffee cherry husk, a by-product of the hulling process in coffee curing factories presents an opportunity for biochar production. While previous studies have explored biochar as a peat substitute in growth media, research on its role in nursery potting mixtures for coffee seedlings is lacking. This study aimed to evaluate the effects of biochar derived from cherry husk on the growth of coffee seedlings and soil properties. Biochar was produced using an electric biomass pyrolyzer at 500°C for one hour and incorporated into the nursery potting medium. The experiment included four treatments: T1 (jungle soil: farmyard manure: sand, control), T2 (biochar: farmyard manure: sand), T3 (jungle soil: biochar: sand), and T4 (jungle soil: farmyard manure: biochar). Results showed that seedling growth in T1 and T4 was statistically similar (CD-0.05%), while growth in T2 and T3 was comparatively lower. Substitution of biochar at the rate of 2% in the potting mixture was found to be optimal for the better growth of coffee seedlings. These findings suggest that biochar can serve as a viable alternative to sand in nursery potting mixtures, potentially improving soil properties and promoting sustainable seedling production.
Enhancing Sustainability, Profitability, and Energy Efficiency through Input Interventions in Existing Farming System in Southern Plain Zone of Rajasthan, India
Authors: Singh Hari , Nai Gopal , Lamba Hemant Kumar , Yadav Narendra
Published: February 2025

Introduction: India is one of the major players in the agriculture sector worldwide and it is the primary source of livelihood for around 55% of India’s population. According to second advance estimates, agriculture & allied sector share 17.60 % in total GVA at current prices in year 2023-24 and the share of industry and service is 27.60 % and 54.90 % respectively. For strengthening the agriculture and enhancing the contribution of agriculture in total GVA, we need to some interventions in for achieve the stated objectives. This study examines input interventions to enhance the sustainability, profitability, and energy efficiency of small and marginal farmers in the Southern Plain Zone of Rajasthan, India.
Methodology:

Analytical tools: - Tabular analysis and energy efficiency tools were used for the reached to findings of the study.
Data Collection: - The primary data collection were conducted from two study period, i.e Period-I (2012-13 to 2015-16), Period-II (2016-17 to 2021-22). In period-I, 60 farmers were selected from Udaipur district and in period-II, 60 farmers were selected from Dungarpur district. A multistage sampling technique was used for the sampling. The District were selected on the basis of higher and lower productivity of maize and wheat crop in tribal area, respectively, and the village were selected by random sampling.

Findings: Introduction of improved maize and wheat cultivars resulted in yield increases of 25%-43% in Udaipur and 47%-61% in Dungarpur compared to conventional varieties. Successful vegetable cultivation led to average net returns of 145.9% (₹127989) in Udaipur and 153.17% (₹121039) in Dungarpur, increasing employment opportunities. Livestock management interventions improved milk yield by 650-850 liters per lactation, and Goatery and poultry farming revenue increased by 16.07% and 14.20%-15.70%, respectively.
Energy efficiency ratios varied across farming systems, with Crop alone exhibiting the highest ratio (3.25) in Udaipur and Crop + Dairy + Horticulture showing notable efficiency (1.56) in Dungarpur. Integration of goat rearing decreased energy use efficiency by up to 10.88%, while vegetable cultivation and poultry rearing increased efficiency by up to 7.58% and 2.75%, respectively.
Conclusion: Intervention of high yielding varieties enhance the farm income of sample farmers in study area but livestock systems were least efficient due to high feed requirements. Dungarpur showed higher energy efficiency in crop and vegetable production but lower efficiency in Goatery compared to Udaipur. These findings highlight the significance of technological interventions for improving farming sustainability, profitability, and energy efficiency.
Impact of Soybean Waste and Pigeon Dropping in the Total Hydrocarbon Content of Crude-oil Polluted Soil
Authors: A. O. Nengi-Benwari, , E. Iboroma, , E. Fidelia, , V.K Robinson,
Published: February 2025

The impact of soybean waste (SBW) and pigeon dropping (PD) in the bioremediation of crude oil polluted soil was investigated. Uncontaminated soil sample was collected from the Rivers State University Research FarmLand. Furthermore, soil sample was contaminated with 5% bonny-light crude oil. SBW and PD were used as the organic supplements. The experimental set-up consisted of 500g of contaminated soil supplemented with SBW and PD separately and in consortium with a control. Bacterial and fungal isolates were determined using standard microbiological methods while the physicochemical parameters were determined using the standard method. The total heterotrophic bacterial load of the soil ranged from 9.5×104 to 1.2×107 CFU/g. The hydrocarbon utilising bacterial load ranged from 7.1×104 to 2.5×105 CFU/g. Fungal load ranged from 7.5×103 to 1.4×105 SFU/g while the hydrocarbon utilising fungal load ranged from 1.3×104 to 5.6×104 SFU/g. Bacillus, Serratia, Pseudomonas and Mycobacterium sp were the hydrocarbon utilising bacteria while Mucor, Aspergillus, Penicillium sp and Saccharomyces sp represented the hydrocarbon utilising fungi. The physicochemical properties of the soil samples before bioremediation showed that the pH ranged from 6.14 to 7.75. The nitrate ranged from 0.813 to 1.216mg/kg; the phosphate ranged from 0.196 to 0.857mg/kg; the total organic carbon (TOC) ranged from 0.88 to 4.89mg/kg and the total hydrocarbon content (THC) ranged from 1419 to 5320mg/kg. The ranges of the physicochemical properties after bioremediation showed that the pH was 6.11 to 7.10, nitrate content 1.903 to 3.016mg/kg, phosphate 0.011 to 0.03 mg/kg, TOC 1.38 to 2.56mg/kg and THC 920 to 4631 mg/kg. The percentage reduction of the THC showed that the highest percentage reduction 52.26% was observed in the crude oil polluted soil amended with SBW followed by the crude oil polluted soil amended with the consortium (50.56%) and PD amended soil had 50.38%, respectively. The % reduction of THC of the unamended crude oil polluted soil was 12.95%). There was no significant difference (P>0.05) in the reduction of THC amongst the treatment. Thus, the use of soybean waste and pigeon droppings for bioremediation is recommended.
Carbon dioxide hydration activity and metal—substrate distances of manganese (II) human carbonic anhydrase B determined by 13C magnetization—transfer NMR
Authors: Led Jens J. , Neesgaard Ebbe , Johansen Jack T.
Published: July 2002

A CO2 hydration activity for Mn(II) human carbonic anhydrase B (MnHCAB) of 7% of the activity of the native Zn2+ enzyme has been determined using a 13C magnetization—transfer NMR approach, that involves two complementary experiments. As this approach also allows a determination of the individual relaxation rates of the enzyme‐bound CO2 and HCO−
3, an evaluation could be made of the distances between these substrates and the paramagnetic Mn2+ in the active site. Thus HCO−
3 is found to bind directly to Mn2+, whereas CO2 is attached relatively weakly to the enzyme without a direct bond to the metal ion.
Base specific interaction of reductively activated nitroimidazoles with DNA
Authors: Declerck P.J. , De Ranter C.J. , Volckaert G.
Published: July 2002

To exert biological activity, nitroimidazole drugs require reductive activation in vivo. Nucleic acids are susceptible to the activated drug in vitro and are presumably the major target in vivo. We carried out electrolytical reduction of several 5‐nitroimidazoles at a controlled potential either in the presence or prior to the addition of DNA. Using a nucleotide sequence specific test to analyse cleavage products, specific interaction of the reduced nitroimidazole intermediate(s) towards the guanine residues is prominent. Since the strand scission depends on subsequent piperidine treatment, it can be concluded that the primary interaction between the activated drug and guanine is a covalent modification weakening the glycosidic bond.
Reduction in p53 synthesis during differentiation of Friend‐erythroleukemia cells
Authors: -Dori Ronit Ben , Resnitzki Dalia , Kimchi Adi
Published: July 2002

The process of cell differentiation in Friend‐erythroleukemia cells was accompanied by 80–90% inhibition of p53 synthesis. This decrease was found to be linked to changes in cell‐cycle distribution characteristics of the growth arrest program during differentiation rather than to the induction of the globin genes. The shut‐off in the expression of p53 always preceded the specific arrest of cells in the G0/G1 phase. Interferon did not modulate down the expression of p53 if added to transformed non‐induced Friend‐erythroleukemia cells; however, it slightly enhanced the extent of reduction in p53 synthesis if added during cell differentiation, thus suggesting a differential effect of interferon between cells at different stages of differentiation
Isolation and characterization of α‐endorphin and γ‐endorphin from single human pituitary glands
Authors: Burbach J.Peter H. , Wiegant Victor M.
Published: July 2002

α‐endorphin and γ‐endorphin, two closely related peptides of the pro‐opiomelanocortin family with characteristics biological activities, were purified to homogeneity from single human pituitary glands and chemically identified. Isolation of the peptides was based on size fractionation by Sephadex G‐75 chromatography followed by two HPLC steps using reverse‐phase and paired‐ion reverse‐phase systems and was monitored by radioimmunoassay. During the isolation procedure α‐and γ‐endorphin‐sized material behaved chromatographically and immunologically indistinguishably from synthetic α‐ and γ‐ endorphin. The amino acid composition and NH2‐terminus of isolated peptides demonstrated their identity as authentic α‐endorphin and γ‐endorphin. Acetylated forms were absent. In addition, evidence is provided that large forms with α‐ and γ‐endorphin immunoreactivity detected during gel filtration are human lipotropin‐(1–74) and ‐(1–75), respectively. The data substantiate that α‐endorphin and γ‐endorphin exist as endogenous peptides in the human pituitary gland.
A phosphorus NMR study of the reaction products of cis‐diamminedichloroplatinum (II) with a double‐helical oligonucleotide and with DNA
Authors: den Hartog Jeroen H.J. , Altona Cornelis , van Boom Jacques H. , Reedijk Jan
Published: July 2002

The structural distortion of oligonucleotides upon cis‐PtCl2(NH3)2{d(T‐C‐T‐C‐G‐G‐T‐C‐T'‐C‐N7(5) N7(6)} reveals shifting of 4 phosphorus resonances due to platination. 3 Resonances could be assigned by selective 31P‐irradiation, showing P(6) (P between the two Gs) to be shifted 1.5 ppm to low field. In the concomitant double strands P(6) is shifted 0.9 ppm to lower field. A similar peak has been observed in platinated salmon sperm DNA (37°C), indicating that Pt‐binding to GpG‐fragments in DNA is similar to that found for the decanucleotide, so the distortion of DNA might be comparable.
Isolation of a novel calcium‐binding protein from streptomyces erythreus
Authors: Leadlay Peter F. , Roberts Graham , Walker John E.
Published: July 2002

A small, acidic protein has been isolated from Streptomyces erythreus. Like eukaryotic calcium‐binding proteins, it exhibits a calcium‐dependent shift in mobility on SDS‐polyacrylamide gel electrophoresis. Its N‐terminal amino acid sequence contains a potential calcium‐binding site which shows striking homology to the corresponding sites in calmodulin. Direct binding studies using 45Ca showed that the protein, either purified or in cell‐free extracts, is capable of binding calcium with high affinity.
Phosphorylation of p36 in vitro with pp60src
Authors: Glenney John R.
Published: July 2002

P36 is a major substrate of the tyrosine protein kinases. P36 isolated from bovine intestine was used in phosphorylation reactions with pp60src. Phosphorylation was stimulated 3–5‐fold by Ca2+, however the K
m was the same (2.5μM) at high or low Ca2+. Although the level of free Ca2+ needed for this enhanced phosphorylation was 10−4–10−3)−3 M, phosphatidylserine shifted the Ca2+ sensitivity to the 10−6–10−5 M range. Independent evidence suggested that p36 interacts directly with liposomes containing phosphatidylserine. This raises the possibility that p36, like c‐kinase, is a Ca2+‐activated, phospholipid‐dependent protein.
Molecular cloning and nucleotide sequence of a cDNA clone coding for rat brain myelin proteolipid
Authors: Dautigny André , Alliel Patrick M. , d'Auriol Luc , Dinh Daniéle Pham , Nussbaum Jean-Louis , Galibert Francis , Joliès Pierre
Published: July 2002

A cDNA library from rat brain was constructed in pBR322 and screened with a 14‐mer mixed oligonucleotide probe based on residues 231–235 of bovine proteolipid (PLP). A positive clone was isolated: it contained a 1334‐base‐pair cDNA insert and was subjected to DNA sequence analysis. The cDNA encoded information for the 276 amino acids of rat PLP. Comparison with bovine PLP sequence showed a complete amino acid sequence homology except for 4 amino acid residues.
Dual effects of organic solvents on chloroplast phosphoribulokinase and NADP‐glyceraldehyde‐3‐P dehydrogenase
Authors: Wolosiuk Ricardo A. , Corley Esteban , Crawford Nancy A. , Buchanan Bob.B.
Published: July 2002

Organic solvents miscible in water (cosolvents) exerted a dual effect on the activation stage of two thioredoxin‐linked enzymes of the reductive pentose phosphate cycle, phosphoribulokinase and NADP‐glyceraldehyde‐3‐P dehydrogenase, both from spinach chloroplast; the enzyme specific activity was stimulated and inhibited by low and high concentrations of alcohols, respectively. On the contrary, cosolvents inhibited the catalytic process. In the stimulation of phosphoribulokinase activation, organic solvents reduced the requirement for thioredoxin‐f and changed the thiol specificity, so that monothiols became functional. The cosolvent‐mediated enhancement of NADP‐glyceraldehyde‐3‐P dehydrogenase was obtained in the absence of modulators. With both enzymes, the concentration of the organic solvents required for activation was inversely proportional to its hydrophobicity (1‐butanol < 1‐propanol < 2‐propanol < ethanol). The present results demonstrate the participation of a new component, the enzyme microenvironment, in the regulation of thioredoxin‐linked chloroplast enzymes.
Characterization of new gangliosides of the lactotetraose series in murine xenografts of a human glioma cell line
Authors: Månsson J.-E. , Fredman P. , Bigner D.D. , Molin K. , Rosengren B. , Friedman H.S. , Svennerholm L.
Published: July 2002

The major mono–and disialogangliosides of the extensively characterized established human glioma line D54MG were isolated and purified from subcutaneous solid xenografts grown in athymic (nu/nu) mice. Structural determination showed that they belonged to the lactotetraosylceramide series. The sialyllactotetraosylceramide contained 90% N–glycolyl– and 10% N–acetylneuraminic acid linked in an α2–3 linkage (IV3NeuGc–LcOse4Cer, IV3NeuAc–LcOse4Cer). The disialogangliosides had a previously undescribed type of structure with sialic acids linked to the terminal galactose in an α2–3 linkage and to N–acetylglucosamine in an α2–6 linkage. Not only did species with NeuAc or NeuGc occur, but also species with mixtures of the two sialic acids, e.g. NeuAC and NeuGc. The schematic structures of the new disialogangliosides are
Isolation of a rat pineal gland cDNA clone homologous to tyrosine and phenylalanine hydroxylases
Authors: Darmon Michèle C. , Grima Brigitte , Cash Christopher D. , Maitre Michel , Mallet Jacques
Published: July 2002

A rat pineal gland cDNA expression library has been probed with an antiserum raised against rat tryptophan hydroxylase. A clone has been isolated and its sequence reveals a high degree of homology with those of tyrosine and phenylalanine hydroxylases.
Transfer of functional opiate receptors from membranes to recipient cells by polyethylene glycol‐induced fusion
Authors: Tocqué B. , Pfeiffer A. , Klee A.
Published: July 2002

Opiate receptor‐mediated inhibition of adenylate cyclase activity was elicited in membranes of C6BUI glioma cells and S49 cyc− lymphoma cells after fusion with opiate receptor‐containing membranes derived from NG108‐15 neuroblastoma × glioma hybrid cells. The fusion was induced by polyethylene glycol using procedures developed by Orly and Schramm [(1976) Proc. Natl. Acad. Sci. USA 73, 4410–4414]. Prior to fusion, the adenylate cyclase activity of the donor, NG108‐15 cell membrane, was inactivated by N‐ethylmaleimide treatment. Prostaglandin E1 receptors and the stimulatory GTP‐binding protein Ns were transferred to the recipient cells along with opiate receptors. Thus, inhibitory receptors can be tranferred to foreign adenylate cyclase systems just as stimulatory receptors had earlier been found to do. Furthermore, opiate receptors have been shown to function in non‐neuronal cells.
Murine erythroleukaemia cells (Friend cells) possess high‐affinity binding sites for erythropoietin
Authors: Mayeux P. , Billat C. , Jacquot R.
Published: July 2002

Murine erythroleukaemia cells represent erythroid precursors blocked near the CFU‐E or proerythroblast stage. In contrast to their non‐leukaemic equivalents, neither their proliferation nor their differentiation seems to be affected by erythropoietin. However, we show in this paper that both uncommitted and committed, benzidine‐positive, cells bind iodinated erythropoietin. The binding is of high affinity (K
d = 490 ± 160 pM) and reversible with a half‐life of the complex of 77 ± 19 min. The number of binding sites is low (300–600 per cell). In contrast the haematopoietic non‐erythroid cell lines HL 60 and L 1210 and the myeloiderythroid human cell line K 562 do not exhibit specific binding. If these binding sites represent true hormone receptors, their presence on a permanent cell line should facilitate erythropoietin receptor purification
Tight binding dopamine reuptake inhibitors as cocaine antagonists
Authors: Rothman Richard B. , Mele Andrea , Reid Audrey A. , Akunne Hyacinth , Greig Nigel , Thurkauf Andrew , Rice Kenner C. , Pert Agu
Published: July 2002

The experiments reported in this study tested the hypothesis that tight binding dopamine (DA) reuptake inhibitors might act as cocaine antagonists. Binding studies demonstrated that the high affinity dopamine reuptake inhibitor, 1‐[2‐[bis(4‐fluorophenyl)methoxy]ethyl]‐4‐[3‐phenylpropyl]piperazine (GBR12909) produced a wash‐resistant inhibition of the DA transporter in rat striatal membranes as labeled by [3H]cocaine or [3H]1‐[2‐(diphenyl‐methoxy)ethyl]‐4‐(3‐phenylpropyl)piperazine ([3H]GBR12935), indicative of tight binding. In vivo microdialysis experiments showed that administration of 25 GBR12909 to rats produced a modest, but not statistically significant, increase in the extracellular levels of striatal DA, while this same dose of GBR12909 inhibited the ability of cocaine to elevate extracellular DA levels by 64%. These data suggest that tight binding DA reuptake blockers may provide a fruitful approach for developing a cocaine antagonist.
Accumulation of ornithine decarboxylase mRNA accompanies activation of human and mouse monocytes/macrophages
Authors: Messina Luigi , Arcidiacono Antonio , Spampinato Giuseppina , Malaguarnera Lucia , Berton Giorgio , Kaczmarek Leszek , Messina Angelo
Published: July 2002

Accumulation of ornithine decarboxylase (ODC) mRNA was investigated in human monocytes and mouse peritoneal macrophages. Treatment of both populations of mononuclear phagocytes with bacterial lipopolysaccharide induced a marked and rapid increase in the accumulation of the ODC gene transcript. A similar phenomenon, albeit less pronounced, was also observed following treatment of human monocytes with human recombinant interferon‐γ. These results suggest a role for ODC, and therefore polyamines, in the regulation of mononuclear phagocyte functions.
Insertion and translocation of proteins into and through membranes
Authors: Lazdunski Claude J. , Benedetti Hélène
Published: July 2002

In prokaryotic and eukaryotic organisms proteins are efficiently sorted to reach their final destinations in a whole range of subcellular compartments. Targeting is mediated by Hydrophobie signal sequences or hydrophilic targeting sequences depending upon the compartment, these sequences being often processed. Proteins cannot be translocated through a membrane in a tightly folded stage, they must have a loose conformation, the so‐called ‘translocation competent state’, which is usually kept through interactions with chaperones. In addition to these cytosolic receptor‐like components, receptors are also present on the target membranes. Depending upon the organelles and organisms, two different energy sources have been identified, energy rich phosphate bonds (ATP and GTP) and a potential across the target membrane. Besides the signal peptides various classes of signals have been identified to account for topologies of membrane proteins. Protein secretion in bacterial organisms has been extensively studied. Various classes of proteins use different strategies some of these may also be used in eukaryotic cells.
The yeast DNA repair proteins RAD1 and RAD7 share similar putative functional domains
Authors: Schneider Rainer , Schweiger Manfred
Published: July 2002

Sequence information on eukaryotic DNA repair proteins provided so far only few clues concerning possible functional domains. Since the DNA repair process involves a strict sequential complex formation of several proteins [(1988) FASEB J. 2, 2696–2701], we searched for special protein‐protein interacting domains, which consist of tandemly repeated leucine rich motifs (LRM). Search algorithms, capable of detecting even largely divergent repeats by assessing their significance due to the tandem repetitivity, revealed that the yeast DNA repair proteins RAD1 and RAD7 contain 9 and 12 tandem LRM repeats, respectively. These results represent the first clues concerning specific domains in these proteins and assign them to the LRM superfamily, which includes such members as yeast adenylate cyclase, cell surface protein receptors and ribonuclease/angiogenin inhibitor, all exerting their function by specific protein‐protein interactions involving LRM domains [(1988) EMBO J. 7, 4151–4156; (1990) Proc. Natl. Acad. Sci. USA 87, 8711–8715; (1989) Science 245, 494–499; (1990) Mol. Cell. Biol. 10, 6436–6444; (1989) Proc. Natl. Acad. Sci. USA 86, 6773–6777].
Refined crystal structure of ytterbium‐substituted carp parvalbumin 4.25 at 1.5 Å, and its comparison with the native and cadmium‐substituted structures
Authors: Kumar Vinod D. , Lee Lana , Edwards Brian F.P.
Published: July 2002

The crystal structure of carp parvalbumin 4.25 containing a 1:1 molar ratio of ytterbium chloride to protein has been refined at 1.5 Å resolution by restrained least‐squares methods to a crystallographic R value of 0.199. The crystal structure confirms the NMR studies, which suggest that low concentrations of ytterbium cause an extensive displacement of calcium from the EF metal binding site. A comparison of the ytterbium‐substituted model with the native and cadmium‐substituted structure show no significant differences, except around the substituted EF metal‐binding region. The displacement of calcium by ytterbium at the EF site has caused a movement in the polypeptide backbone of Ser‐91 and Asp‐92. This movement resulted in an increase in the number of oxygen ligands bound to ytterbium in the EF site from seven to eight.
Induction of cytokines in glial cells by trans activator of human T‐cell lymphotropic virus type I
Authors: Sawada Makoto , Suzumura Akio , Kondo Noriaki , Marunouchi Tohru
Published: July 2002

Human T‐cell lymphotropic virus type I (HTLV‐I), the cause of adult T‐cell leukemia, is also associated with the neurological disease, TSP/HAM (tropical spastic paraparesis/HTLV‐I associated myelopathy). The HTLV‐I genome encodes a protein, Tax, that trans activates viral and cellular gene transcription. To understand the mechanisms for the production of cytokines by HTLV‐I in nervous tissue, we examined their expression in glial cells which carried the Tax‐expressing vector. We demonstrated that Tax expression enhanced the production by glial cells of interleukin (IL)‐1, IL‐6, granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) and transforming growth factor (TGF)β. We suggest that the excessive production of cytokines in nervous tissue may play a role in pathogenesis of TSP/HAM, Glial cells that carry the tax gene may provide a model useful for in vitro study of the mechanism of production of cytokines in the nervous system.
Molecular cloning of a cDNA clone for tobacco lipid transfer protein and expression of the functional protein in Escherichia coli
Authors: Masuta Chikara , Furuno Masahiro , Tanaka Hideo , Yamada Mitsuhiro , Koiwai Akira
Published: July 2002

A cDNA clone encoding a lipid transfer protein (LTP) was isolated from tobacco by screening a library with a PCR‐amplified spinach LTP gene, DNA sequence analysis showed a large open reading frame (344 bp) encoding a polypeptide of 114 amino acids. The first 23 amino acids of the deduced protein have the characteristics of a signal peptide for protein secretion or targeting into dense microbody‐like vesicles. The cDNA clone was then inserted into an expression vector, pMAL, and expressed in E. coli as a fusion with the maltose binding protein (MBP). The MBP‐LTP fusion protein was purified to homogeneity and subjected to factor Xa cleavage to yield the LTP domain. A lipid transfer assay demonstrated that the resulting LTP was functional. The availability of the expression system in E. coli will facilitate the elucidation of in vivo function(s) of plant LTPs.
Three‐dimensional structure of a barnase‐3'GMP complex at 2.2Å resolution
Authors: Guillet Valéric , Lapthorn Adrian , Mauguen Yves
Published: July 2002

Barnase has been co‐crystallized at neutral pH with its natural product the 3'‐guanylic acid. The X‐ray structure was solved by molecular replacement methods and refined to a final R‐factor of 18.7%. The protein folding is essentially the same as that of the native form. The base recognition site is almost identical to that of the homologous binase‐3'GMP complex, but the nucleotide is bound in a productive binding mode for a substrate with a syn glycosyl torsion angle allowing the general base Glu73 to hydrogen bond with the 2'O of the nucleotide as is assumed in the classical catalytic mechanism. The two molecules of the asymmetric unit form a dimer and the positions of the two nucleotides partially mimic the interaction of the RNA with the enzyme, one of the inhibitors being located in a secondary subsite.
Hepatocyte growth factor‐like protein is identical to macrophage stimulating protein
Authors: Shimamoto Akira , Kimura Toru , Matsumoto Kunio , Nakamura Toshikazu
Published: July 2002

Although the hepatocyte growth factor‐like protein (HLP) shares a 50% homology with the hepatocyte growth factor, the biological function of HLP has remained unknown. Addition of conditioned medium of COS‐7 cells transfected with the expression plasmid for HLP cDNA to cultures of resident peritoneal macrophages induced specific activation of macrophages, and the factor which stimulates macrophages was purified from the conditioned medium. The purified protein showed M
r of 85 kDa on SDS‐PAGE, and this M
r is in agreement with that of macrophage‐stimulating protein (MSP) previously purified from human serum, as well as with the predicted M
r of HLP. Amino acid composition of the purified protein coincided with the compositions of human HLP and MSP. Together with the finding that the partial amino acid sequences of MSP are highly homologous to that of HLP, we conclude that the biological function of HLP is to activate macrophages and that HLP and MSP are identical molecules.
Inversion of Ca2+ current modulation during recovery of neuroblastoma cells from pertussis toxin pretreatment
Authors: Friederich P. , Nürnberg B. , Schultz G. , Hescheler J.
Published: July 2002

Human neuroblastoma cells (SH‐SY5Y) differentiated by retinoic acid exhibited high threshold‐activated N‐type Ca2+ currents, which were largely inhibited by the two enkephalins, DAGO and DPDPE, as well as by dopamine and somatostatin. The inhibitory effects were fully abolished after pretreatment of cells with pertussis toxin. After washing out the toxin, the inhibitory effects re‐established with a time constant of about 16 h. The recovery of Ca2+ current inhibition was similar for all tested agonists. Unexpectedly, we observed a neurotransmitter‐induced stimulation of Ca2+ currents in approximately 10% of all investigated cells during the recovery phase. Such a stimulatory effect by otherwise inhibitory receptors was never seen in control cells. It did also not occur when exogenous purified G‐proteins of the Gi family were reconstituted via the patch pipette, suggesting that additional mechanisms may play a role in the appearance of stimulatory effects during the recovery phase after pertussis toxin pretreatment.
Production of biologically active light chain of tetanus toxin in Escherichia coli
Authors: Fairweather Neil F. , Sanders Dagmar , Slater Debbie , Hudel Martina , Habermann E. , Weller Ulrich
Published: July 2002

The activity of the light (L) chain of tetanus toxin, and of mutants constructed by site‐directed mutagenesis, was studied by expression and purification of the proteins from E. coli. Wild‐type recombinant L chain (pTet87) was active in the inhibition of exocytosis from cultured bovine adrenal chromaffin cells, although at a level 5–15% of that of L chain purified from tetanus toxin. L chain mutants which terminated at Leu‐438 (pTet89), or which contained a Cys‐to‐Ser mutation at residue 439 (pTet88) were equally as active as the full‐length recombinant protein. The reduced activity of pTet87 L chain correlated with C‐terminal proteolysis of the protein upon purification. A tryptic fragment derived from native light chain and which terminated at Leu‐434 also showed reduced activity in the exocytosis assay, consistent with a requirement of the C‐terminal region of the L chain for maximal activity. pTet87 L chain, but neither of the mutants, could be associated with purified H (heavy) chain to form a covalent dimer which induced the symptoms of tetanus in mice. The ability to form biologically active toxin using recombinant L chain will be of great value in structure‐function studies of tetanus toxin.
A synthetic peptide mimics troponin I function in the calcium‐dependent regulation of muscle contraction
Authors: Van Eyk Jennifer E. , Strauss John D. , Hodges Robert S. , Rüegg J.Casper
Published: July 2002

A new technique for treating skinned cardiac muscle fibers has been developed in which troponin I is extracted, giving rise to unregulated fibers. The effect of the 12‐residue troponin I peptide on these fibers indicates that this region of troponin I is solely responsible for muscle relaxation (inhibition of force). Furthermore, troponin I peptide‐troponin C reconstituted fibers are stable through several contraction‐relaxation cycles indicating the peptide can switch binding sites between actin and troponin C. The troponin I peptide can substitute for the native protein as part of the calcium‐sensitive molecular switch that controls muscle regulation.
Receptors for mammalian steroid hormones in microbes and plants
Authors: Agarwal M.K.
Published: July 2002

Steroids are of universal occurrence, present variously as cell wall constituents and bioregulators. A number of bacteria, fungi, and photosynthetic vascular plants synthesize steroids that are hormonally active in the animal world. The cellular effect of such steroids in microbes and plants appears by and large to be comparable to that in mammals. Available evidence suggests that steroid action in botanical phyla is mediated via receptors organized in a manner similar to that seen in animals. Therefore, the ancestry of ligand induced transactivation via zinc finger proteins appears to date farther back than the early Cambrian burst of metazoan evolution 500 million years ago.
Isolation and characterization of two cDNAs encoding for compartment specific isoforms of O‐acetylserine (thiol) lyase from Arabidopsis thaliana
Authors: Hell Rüdiger , Bork Christiane , Bogdanova Natascha , Frolov Igor , Hauschild Rüdiger
Published: July 2002

cDNAs encoding for two isoforms of O‐acetylserine (thiol) lyase (OAS‐TL), which catalyzes the synthesis of cysteine, have been isolated from Arabidopsis thaliana. Secondary structure together with expression patterns derived during photomorphogenesis indicate cellular localizations in the cytosol and plastids, thus allowing a direct comparison of compartment‐specific forms within one species. The cytosolic OAS‐TL complemented an E. coli auxotrophic mutant lacking cysteine synthesis. Both isoforms are represented by small gene families. They are expressed under all conditions investigated and were observed to increase in expression in plants grown with limited sulfate supply.
Identification of amino acid residues associated with the [2Fe‐2S] cluster of the 25 kDa (NQO2) subunit of the proton‐translocating NADH‐quinone oxidoreductase of Paracoccus denitrificans
Authors: Yano Takahiro , Sled Vladimir D. , Ohnishi Tomoko , Yagi Takao
Published: July 2002

In order to identify the ligand residues of the [2Fe‐2S] cluster of the 25 kDa (NQO2) subunit of the proton‐translocating NADH‐quinone oxidoreductase of Paracoccus denitrificans, we mutated individually all seven cysteine residues (C61, C96, C101, C104, C113, C137, and C141) and one conserved histidine residue (H92) to Ser or Ala and expressed them in E. coli. After purification of the mutated 25 kDa subunits, the effect of mutations on the iron‐sulfur cluster were characterized by chemical analyses and UV‐visible and EPR spectroscopy. All mutated subunits, especially mutants of conserved cysteines, contained lower amounts of non‐heme iron than wild‐type. The subunits of three non‐conserved cysteine residues (C61, C104, and C113) mutated to Ser and a histidine residue (H92) mutated to Ala exhibited essentially the same spectroscopic properties as those of the wild‐type subunit. In contrast, mutation of the four conserved cysteine residues (C96, C101, C137, and C141) to Ser or Ala considerably altered the UV‐visible and EPR spectra from the wild‐type subunit. These results indicate that the four conserved cysteine residues coordinate the [2Fe‐2S] cluster in the P. denitrificans 25 kDa subunit.
Amiodarone‐induced hypercholesterolemia is associated with a decrease in liver LDL receptor mRNA
Authors: Hudig F. , Bakker O. , Wiersinga W.M.
Published: July 2002

Amiodarone decreases plasma and tissue triiodothyronine (T3) and increases plasma cholesterol levels resembling changes seen during hypothyroidism. To elucidate the mechanism of amiodarone‐induced hypercholesterolemia we investigated gene expression of three key proteins in cholesterol metabolism (cholesterol 7α‐hydroxylase, LDL receptor, HMG‐CoA reductase) in livers of rats. Animals were treated with amiodarone or propylthiouracil (to induce mild hypothyroidism). The LDL receptor mRNA was downregulated (≈50%) in both amiodarone‐treated and hypothyroid animals, while the other mRNA remained unchanged after 14‐day treatment. The results suggest that amiodarone‐induced hypercholesterolemia is associated with decreased LDL receptor mRNA levels.