bluuebunny/crossref_metadata_2025 huggingface dataset:
Juan Carlos Tous: "Internet ni canibaliza ni es una amenaza"
Authors: Clares Gavilán Judith
Published: March 2021

En esta entrevista a Juan Carlos Tous, CEO y socio fundador de CAMEO y filmin, analizamos el impacto que está suponiendo la irrupción de Internet en la industria cinematográfica y especialmente en el sector de la distribución. Su impacto en el sector del home-video, la traslación del alquiler tradicional al consumo bajo demanda vía plataformas de Video on Demand (VoD) como filmin, o la apuesta por estrenos en paralelo en cines y en VoD de títulos como Carmina o revienta o distribuciones singulares como Barcelona nit d’estiu son algunas de las cuestiones abordadas.

El curso 2014-15, la Universitat Oberta de Catalunya (UOC) arrancará la 4ª edición del posgrado en Distribución audiovisual: VoD y nuevos modelos de negocio, que puso en marcha conjuntamente con filmin en 2012 con el objetivo de formar alrededor de los cambios que está conllevando la irrupción de Internet en la industria del cine.
COVID-19 Emergency: Faux Healthcare Service Causes Distress and Life Dissatisfaction
Authors: Bhattacharjee A. , Bansal V. , Juman M. K. I.
Published: March 2021

Background and Aims: In Bangladesh, a significant number of individuals experienced a faux coronavirus test, especially at the profit oriented private hospitals or clinics during the COVID-19 emergency. Therefore, the prime purpose of the study was to investigate the impact of healthcare service faux pas on the mental health of Bangladeshi people during the COVID-19 pandemic. Additionally, the current study even explored the changes in life satisfaction of Bangladeshi individuals due to the faux SARS-CoV-2 tests in the country. Moreover, the study also dealt with the satisfaction of the people on the healthcare service during the COVID-19 emergency in Bangladesh. 

Study Design: The current research was conducted as a descriptive and bi-monthly cross-sectional study and used the snowball sampling technique to collect the survey data in Bangladesh.

Place and Duration of Study: This study was employed in Dhaka division and Comilla division of Bangladesh between June and July in 2020.

Methodology: In this study, we surveyed 393 Bangladeshi individuals from two divisions of the country. We measured mental & physical health (SF12), depression (PHQ2), anxiety (GAD2), distress (K6), life satisfaction and overall satisfaction on healthcare service. Survey data was analyzed on STATA platform to find the study findings.

Results: This research found that Bangladeshi people experienced lower levels of mental and physical health conditions with the mean (STD) values of 23.1 (6.9) and 37.2 (9.1) respectively. Among the study participants, female individuals (60.05%) were mostly dissatisfied with the COVID-19 emergency healthcare service and dealt with more severe mental and physical disorders than male persons (39.95%) in the country. In this perspective, the study explored a dramatic increase in the mental stress and steady decline in life satisfaction of Bangladeshi individuals due to the false COVID-19 test certificates. Therefore, most of them had to go through multiple coronavirus tests to confirm the infected status. Additionally, participants visited at private hospitals for SARS-CoV-2 emergency support had higher levels of distress and dissatisfaction on the private healthcare services. Finally, the study found literally poor life satisfaction among all participants.  

Conclusion: The study found mental distress and life dissatisfaction caused by a private healthcare service faux pas in Bangladesh. So, this study suggests that a surge in the private healthcare service faux pas during or post coronavirus pandemic needs sustainable policy standards by the Government and nongovernment concerns. Fruitfully, the proper implementation of new policies especially for the private healthcare organizations is indeed essential to ensure a stress free healthy healthcare environment as well as higher life satisfaction for every individual in the country.
Evaluation of Different Chaba (Piper chaba) Germplasm for Growth and Yield Performances
Authors: Islam Md. Riazul , Mehedi Md. Nazmul Hasan , Ara Rumman , Obaidullah Abu Jafor Mohammad , Moniruzzaman Md. , Aktar Nahida
Published: March 2021

Genetic diversity is the base for survival of plants in nature and for crop improvement. Diversity in plant genetic resources provides opportunity for plant breeders to develop new and improved cultivars with desirable characteristics. Therefore, an experiment was employed to determine the genetic variability and evaluate the growth performing parameters of different Chaba germplasm at the research field of Regional Spices Research Centre, Bangladesh Agricultural Research Institute, Magura during kharif 1 season in 2018-19 following completely randomized design with three replications.  Six germplasm namely PCmag-001, PCmag-002, PCmag-003, PCmag-004, PCmag-005 and PCmag-006 were collected from khulna region of Bangladesh and transplanted adjunct to different tree species mainly mango. Among the six germplasm heighest plant height (450 cm), number of branch (35), number of leaves (350), internodes length (16 cm) and vine diameter (2.5 cm) after one year of planting was recorded from PCmag-001 germplasm followed by PCmag-002 while the lowest plant height (450 cm), number of branch (35), number of leaves (350), internodes length (16 cm) and vine diameter (2.5 cm) were found from the germplasm PCmag-005. Through the observation of one year field trail in terms of growing characteristics the germplasm PCmag-001 and PCmag-002 can be chosen for future breeding material to release a commercial variety in southern part of Bangladesh.
Microbial Diversity of Nigerian Sludge and Its Potential for Use as Biofertilizer
Authors: Fatunla Opeyemi , Essien Joseph , Ofon Utibe , Shaibu Solomon , Dan Emmanuel
Published: March 2021

Sludge samples were collected from a wastewater treatment plant in Nigeria for characterization and evaluation for agricultural applications. Conventional and Molecular techniques were adopted for the isolation and identification of indigenous microorganisms and resulting isolates were characterized and identified by consulting Bergey’s manual of determinative bacteriology and subjected to further screenings to assess their biofertilizer potential using standard microbiological techniques. The viable cells obtained were enumerated and were found to be in the range of 1.03 ± 0.09 x103 cfu/g to 7.45 ± 0.78 x103 cfu/g for heterotrophic Bacteria and 1.63 ± 0.74 x103 cfu/g for fungal community. The Molecular analysis carried out revealed a rich assemblage of diverse species of microorganisms with Bacteria (99.40%) being the most dominant group, followed by Fungi (0.39%) and others (0.21%). Thirty (30) isolates belonging to four (4) Phyla was recovered culturally and identified with Firmicutes 9(30%) being the most dominant group, followed by Proteobacteria 8(26.7%) and Zygomycota 1(3.33%) was the least dominant. The phosphate solubilization index range from 0.86 to 6.3 for bacterial and 2.5 to 3.8 for fungal isolates respectively. The molecular analysis also revealed microbes adept at improving soil fertility to include those in the order Rhizobiales and Actinomycetales. Although pathogens are of a concern in the land application of sludge, our findings have revealed rich microbial consortia of heterotrophic microorganisms whose beneficial attributes can be harnessed to produce nutrient rich biofertilizer and soil amendment.
Acid Challenge on Push-Out Bond Strength of Three Different Tricalcium Silicate Cements: An In-vitro Study
Authors: Babu Mattapudi Basavaiah , Raju T. B. V. G. , Varma N. Mahendra , Dondapati Gowtam Dev , Podili Srivalli , Sowjanya Thangi
Published: March 2021

Aim: To evaluate the impact of environmental pH on intra-radicular dentin push-out bond strengths of MTA, MTA HP, and Biodentine.

Materials and Methodology: Freshly extracted human mandibular single-rooted premolars or maxillary anterior incisors that were either intact or contained only small carious lesions were selected.120 mid root dentins is horizontally divided into 1.0 mm thick slices and divided into 3 MTA, MTA HP, BIODENTINE groups. The compressive load is applied at a speed of 0.5 mm/min by exerting a downward pressure on the outer surface of MTA using a 1.00 mm diameter cylindrical stainless-steel plunger. Maximum load to MTA was reported in newtons at the time of dislodgement and converted to megapascals. The 1-way analysis of variance test was used to compare the push-out bond strength of the groups with the same storage time (4 or 34 days), followed by the pair-wise comparison of the Tukey post hoc test. The Student's t-test was used to evaluate 3-group means. At P = .005, the degree of significance was set. Thus the clinical importance of the present study states that considering several factors like microhardness, composition by products, particle sizes and the environmental pH plays a critical role in selection of root end filling material.

Results: There was significant difference between groups (P = .001) after 4 days of PBS and Acid condition, where Bio dentine had significantly the highest bond strength.

Conclusion: The strength of MTA HP, BIODENTINE, MTA materials at dentine interface increases over 30 days in the storage of PBS solution at pH 7.4, after an initial acid challenge by acetic acid of pH 5.4, which decreases initial bond strength.
Analysis of Renal Platinum Content as a Novel Approach to Protect against Cisplatin Nephrotoxicity: A Review
Authors: Mahran Yasmen F. , Kamaly Omkulthom M. Al
Published: March 2021

Cisplatin (cis-diamine-dichloroplatinum (II), CDDP) is a prominent member of the effective broad-spectrum antitumor drugs. However, its clinical usage is restricted due to serious side effects particularly nephrotoxicity. The vulnerability of the kidney to CDDP is almost certainly related to its primary role in the excretion of the drug as intact CDDP and its platinum containing products are excreted mainly in the urine. There is a correlation between the level of platinum in urine and nephrotoxicity because of renal uptake of the drug. Some analytical methods were applied for the determination of platinum content in biological fluids such as plasma, urine, serum, and peritoneal fluid. Studies have not documented a strong correlation between the renoprotective mechanism and the diminution of renal platinum content.
Mothers Education and Respiratory Infection in Under-Five Children in Nigeria
Authors: Paul Joseph , Osu-Kure Dorcas Afanyinya
Published: March 2021

Respiratory infection is one of the major causes of child ill health and mortality not only in Nigeria, but in most developing countries of the world. This study therefore, investigated the causal relationship between mothers’ level of education and under-five age respiratory infection in Nigeria. Probit regression is used to analyse data from Nigeria Multiple indicator cluster survey 2017. Results from the bivariate regression indicated a significant negative relationship between mothers’ educational level and respiratory infection in under-five age children in Nigeria. Mothers’ educational level became insignificant after controlling for other important covariates which signifies an indirect relationship with child respiratory infection. This implies that mothers’ education influences child respiratory disorder through other variables like place of residence and immunization. Other variables found to influence child respiratory infection includes region of residence, age of child, immunization and ethnicity. On the other hand, sex of child and wealth index were not found to be significant determinants of child respiratory infection. Nigerian government should encourage girl child education through the provision of free quality education at least to secondary school level. Programs to target free diagnosis, treatment and prevention of respiratory infection especially among under-five children should be prioritized by the ministry of health. Health care providers should also intensify awareness to mothers on preventive measures of child respiratory infection especially during antenatal care programs.
Ricin B chain converts a non‐cytotoxic antibody‐ricin A chain conjugate into a potent and specific cytotoxic agent
Authors: McIntosh D.P. , Edwards D.C. , Cumber A.J. , Parnell G.D. , Dean C.J. , Ross W.C.J. , Forrester J.A.
Published: July 2002

We report the conversion of a non‐cytotoxic antibody‐ricin A chain conjugate to one displaying specific cytotoxic effects comparable with that of native ricin, by the addition of ricin B chain as a second stage reagent. The results suggest that this conversion is achieved by the association of the added B chain with the A chain of the conjugate, and not through a primary binding of B chain at the cell surface.
Diazepam inhibits cell respiration and induces fragmentation of mitochondrial reticulum
Authors: Vorobjev Ivan A. , Zorov Dmitry B.
Published: July 2002

Diazepam (70–150 μg/ml) significantly inhibits oxygen consumption by pig kidney embryo cells and causes the cellular ATP level to fall. The maximum inhibitory effect develops after 1.5–2.5 h of diazepam treatment. In isolated mitochondria diazepam inhibits respiration in state 2 and 3u with glutamate and in state 3u with succinate. Ethylrhodamine staining and electron microscopic study reveal fragmentation of mitochondria in living cells.
In vivo 31P nuclear magnetic resonance saturation transfer measurements of phosphate exchange reactions in the yeast Saccharomyces cerevisiae
Authors: Campbell Sharon L. , Jones Kerri A. , Shulman Robert G.
Published: July 2002

31P saturation transfer techniques have been used to measure phosphate kinetics in the yeast Saccharomyces cerevisiae. The phosphate consumption rate observed in acetate grown mid‐log cells was combined with measurements of O2 consumption to yield P/O ratios of 2.2 and 2.9, for cells respiring on glucose and ethanol, respectively. However, no phosphate consumption activity was observed in saturation transfer experiments on anaerobic glucose fed cells. The phosphate consumption rates measured by saturation transfer in cells respiring on glucose and ethanol was attributed to the unidirectional rates of mitochondria! ATP synthesis.
Evidence for a symmetrical uptake of fluorescent dyes through electro‐permeabilized membranes of Avena mesophyll protoplasts
Authors: Mehrle W. , Zimmermann U. , Hampp R.
Published: July 2002

The permeability properties of the plasmalemma of oat mesophyll protoplasts during the application of an electric field pulse were studied. As a measure, the intracellular fluorescence resulting from the uptake of DNA and RNA staining dyes (ethidium bromide, berberine hemisulfate), showing a very low rate of permeation across the plasmalemma of intact protoplasts, were determined microphotometrically. The results show that membrane breakdown, caused by supercritical field strengths, leads to an uptake of the charged dyes only via those membrane sites oriented toward the positive electrode. Mechanisms possibly underlying this asymmetrical uptake as well as its practical application are discussed.
NMR studies of fluorophenylalanine‐containing carbonic anhydrase
Authors: Gamcsik M.P. , Gerig J.T.
Published: July 2002

Rabbits ingesting 4‐fluorophenylalanine are known to incorporate small amounts of this fluorinated amino acid into their proteins. Carbonic anhydrase I isolated‐from the erythrocytes of animals so maintained exhibits a well‐resolved fluorine NMR signal for each phenylalanine in the sequence. The chemical shifts of most of these signals respond to the binding of inhibitors, suggesting that most if not all of the tertiary structure of the enzyme adjusts to the presence of inhibitors at the the active site.
Amino acid sequence determination of guuanyl‐specific ribonuclease Sa from Streptomyces aureofaciens
Authors: Shiyapnikov S.V. , Both V. , Kulikov V.A. , Dementiev A.A. , Ševčík J. , Zeiinka J.
Published: July 2002

Using automated Edman degradation of two nonfractionated peptide mixtures of tryptic and staphylococcal protease digests of the protein, the complete amino acid sequence of the guanyl‐specific ribonuclease Sa from Streptomyces aureofaciens was established. Ribonuclease Sa contains 96 amino acid residues (M
r 10 566). A 50% sequence homology of ribonuclease Sa to the guanyl‐specific ribonuclease St from S. erythrew was found.
Reconstitution of the active rat liver 60 S ribosomal subunit from different preparations of core particles and split proteins
Authors: Lavergne Jean-Pierre , Marzouki Abdelkader , Reboud Jean-Paul , Reboud Anne-Marie
Published: July 2002

Proteins extracted from the 60 S rat liver ribosomal subunit with 50% ethanol/0.5 M KCl produced only a partial reactivation of the corresponding core particles. In contrast, the same split proteins were able to reactivate the core particles prepared with dimethyl‐maleic anhydride (DMMA) to the same level as that observed using the DMMA‐split proteins, i.e. 60–80% of the control according to the catalytic activities tested. Comparative analysis of the two split protein fractions showed only four common proteins: P1–P2, which alone restored part of the activities, especially the EF‐2‐dependent GTPase one, and L10a, L12, which must be responsible for the additional reactivation. The poor ability of the ethanol/KCl core particles to be reactivated was shown to be probably related to a conformational alteration which destabilized the 5 S RNA‐protein complex. Proteins present in the ethanol/KCl wash of Saccharomyces cerevisiae 60 S subunits were found to be partly active in subunit reconstitution using rat liver DMMA core particles.
Tumor necrosis factor and interleukin 1 activate phospholipase in rat chondrocytes
Authors: Suffys Philip , Van Roy Frans , Fiers Walter
Published: July 2002

Tumor necrosis factor (TNF) and interleukin 1 (IL‐1) are both cytokines of macrophage origin with similar activity on several cell types. We investigated whether TNF can, analogously to IL‐1, stimulate phospholipase activity of chondrocytes. Addition of each of these cytokines to cells, isolated from the xiphisternum of adult rats, resulted in a time‐ and dose‐dependent increase in phospholipase activity in both secreted and membrane‐associated form. Moreover, TNF and IL‐1 both induce a transformation of chondrocyte morphology. In conclusion, TNF stimulates chondrocyte phospholipase activity and extends the long list of actions shared by IL‐1 and TNF in a diversity of cellular systems.
Possible adsorption sites of cellulases on crystalline cellulose
Authors: Henrissat Bernard , Vigny Béatrice , Buleon Alain , Perez Serge
Published: July 2002

The possible adsorption sites of cellulases on crystalline cellulose were investigated by molecular graphic representation of a crystal of cellulose and estimation of the accessibility of the various glycosidic bonds to enzymatic attack. The results show that only certain glycosidic bonds of certain surface cellulose chains are susceptible to enzymatic hydrolysis. These preferential sites correlate well with previous electron microscopy observations of the adsorption sites of 1,4‐β‐D‐glucan cellobiohydrolase I (CBHI) from Trichoderma reesei on Valonia cellulose.
Expression of the vasopressin and oxytocin genes in rats occurs in mutually exclusive sets of hypothalamic neurons
Authors: Mohr Evita , Bahnsen Ulrich , Kiessling Christiane , Richter Dietmar
Published: July 2002

The genes for the hypothalamic hormones vasopressin and oxytocin are located in close proximity to each other within the rat genome. They are separated by only approx. 11 kbp of DNA sequence and oriented in such a way that their transcription occurs on opposite DNA strands. Although the two genes are structurally very similar including common potential regulatory elements in their putative promotor regions, they are expressed in discrete populations of magnocellular neurons of the hypothalamus. In rats placed under osmotic stress, the vasopressin gene is unregulated; concomitantly transcription of the oxytocin gene is also stimulated. To address the question of whether this coordinated rise in oxytocin‐encoding mRNA is the result of switching on oxytocin gene transcription in vasopressinergic neurons, in situ hybridization with double labelled cRNA probes was carried out. Biotinylated and [α‐35S]CTP labelled antisense cRNA probes specific for either vasopressin or oxytocin mRNA were constructed and hybridized to hypothalamic sections from salt‐loaded rats. The results demonstrate that upregulation of oxytocin gene transcription is restricted solely to oxytocinergic cells; no oxytocin gene transcripts can be detected in vasopressinergic neurons.
Carbonic anhydrase II is induced in HL‐60 cells by 1,25‐dihydroxyvitamin D3: A model for osteoclast gene regulation
Authors: Shapiro Linda Hillstrom , Venta Patrick J. , Yu Ya-Shiou L. , Tashian Richard E.
Published: July 2002

Carbonic anhydrase II (CA II) generates the H+ required for osteoclast‐mediated bone resorption in humans. We have developed the human promyelocytic cell line HL‐60 as a model system with which to study the osteoclast‐specific expression of the CA II gene. Treatment of the cell line with 1,25‐dihydroxyvitamin D3 resulted in a dramatic de novo induction of CA II at both the protein and mRNA levels. CA II mRNA was also induced to a lesser extent by 12‐O‐tetradecanoyl phorbol 13‐acetate. Treatment with dimethyl sulfoxide did not increase CA II mRNA. These findings indicate that the HL‐60 cell line will be a useful model system to study the osteoclast‐specific expression of the CA II gene.
Synergistic enhancement of type I and III collagen production in cultured fibroblasts by transforming growth factor‐β and ascorbate
Authors: Appling W.Douglas , O'Brien Wanda R. , Johnston Dennis A. , Duvic Madeleine
Published: July 2002

Transforming growth factor‐β (TGF‐β) is a prototype of a family of polypeptides that regulates cellular growth and phenotypic differentiation [(1986) Science 233, 532‐534; (1987) Cell 49, 437‐438]. TGF‐β injection induces angiogenesis and fibrosis locally [(1986) Proc. Natl. Acad. Sci. USA 83, 4167‐4171; (1987) Science 237, 1333‐1336] and stimulates the synthesis of extracellular matrix proteins, fibronectin, collagens, and proteoglycans in vitro in many cell types [(1986) J. Biol. Chem. 261, 4337‐4345; (1987) Biochem J. 247, 597‐604]. Ascorbate is also known to induce collagen synthesis and to promote wound healing [(1988) J. Invest. Dermatol. 90, 420‐424; (1986) Coll. Rel. Res. 6, 455‐466]. We report that in cultured human skin fibroblasts, ascorbate and TGF‐β synergistically enhance the biosynthesis of type I and III collagens and their steady‐state mRNAs. TGF‐β alone has no enhancing effect on type III collagen synthesis. The cooperation between ascorbate and TGF‐β may be of significance in wound healing and in disorders of fibrosis.
ATP‐synthase complex: The mechanism of control of ion fluxes induced by cumene hydroperoxide in mitochondria
Authors: Novgorodov S.A. , Gudz T.I. , Mohr Yu.E. , Goncharenko E.N. , Yaguzhinsky L.S.
Published: July 2002

In state 4, the cumene hydroperoxide‐induced decrease of mitochondrial transmembrane potential is prevented by the free radical scavenger, butylhydroxytoluene. This decrease is accompanied by accumulation of lipid hydroperoxides. Oligomycin suppresses the cumene hydroperoxide‐induced uncoupling of mitochondria, but has no significant effect on lipid peroxidation. The transition of mitochondria from state 4 to state 3 by ADP addition leads to the suppression of both lipid peroxidation and mitochondrial uncoupling. This effect on lipid peroxidation is prevented by carboxyatractyloside and oligomycin.
Monoclonal antibodies against defined regions of the muscular dystrophy protein, dystrophin
Authors: Man Nguyen thi , Cartwright A.J. , Morris G.E. , Love D.R. , Bloomfield J.F. , Davies K.E.
Published: July 2002

Nineteen monoclonal antibodies which bind to native dystrophin in the plasma membrane of frozen muscle sections were obtained using a recombinant fusion protein as immunogen. On Western blots of normal mouse muscle extracts, the antibodies bind specifically to a 400 000 M
r protein which is absent from dystrophic mouse (mdx) muscle. At least four distinct epitopes have been identified by cleavage mapping methods. Although the fusion protein contained 25% of the human dystrophin sequence (Cys816‐Asp1747; M
r 108 000), most of the monoclonal antibodies (15 out of 19) recognize a single fragment of M
r 27 500.
Stimulation of nerve growth factor synthesis/secretion by 1,4‐benzoquinone and its derivatives in cultured mouse astroglial cells
Authors: Takeuchi Rie , Murase Katsuhito , Furukawa Yoshiko , Furukawa Shoei , Hayashi Kyozo
Published: July 2002

Previously we reported that astroglial cells cultured from mouse brain synthesize and secrete nerve growth factor (NGF) and that, in quiescent cells, catecholamines markedly increase the NGF content in the conditioned medium (CM). We wished to further assess the structural properties required for exhibition of such effect of compounds containing a ring structure analogous to that of catechol on astroglial NGF synthesis. During our study, we found that hydroquinone, which was confirmed not to stimulate NGF synthesis in mouse flbroblast cells in another of our investigations, is a potent stimulator of NGF synthesis in astroglial cells and that 1,4‐benzoquinone, an oxidized form of hydroquinone, is a more effective stimulator than hydroquinone itself. In addition, the results of experiments with 1,2‐benzoquinone derivatives indicated that the presence of a long aliphatic side chain in the molecule eliminates the stimulatory effect of 1,4‐benzoquinone on NGF synthesis in astroglial cells.
Cloning and sequence analysis of a cDNA for human glycosylasparaginase
Authors: Fisher Krishna J. , Tollersrud Ole K. , Aronson Nathan N.
Published: July 2002

We have isolated a full‐length cDNA (HPAsn.6) for human placenta glycosylasparaginase using a 221‐bp PCR amplified fragment containing rat liver asparaginase gene sequences. The deduced amino acid sequence from the human clone showed sequence identity to both the α and β subunits of the rat enzyme. The human enzyme is encoded as a 34.6 kDa polypeptide that is post‐translationally processed to generate two subunits of approx. 19.5 (α) and 15 (β) kDa. A charge enriched region is present at the predicted site where cleavage occurs. Using polyclonal antibodies against the α and β subunits of rat liver asparaginase, we have shown that the human enzyme is similar in structure to the rat enzyme.
Bryophyllum fedtschenkoi protein phosphatase type 2A can dephosphorylate phosphoenolpyruvate carboxylase
Authors: Carter P.J. , Nimmo H.G. , Fewson C.A. , Wilkins M.B.
Published: July 2002

Phosphoenolpyruvate carboxylase, which catalyses the nocturnal fixation of CO2 in Crassulacean acid metabolism (CAM) plants, is regulated by reversible phosphorylation. The phosphorylated ‘night’ form of the enzyme is ten‐fold less sensitive to inhibition by malate than is the dephosphorylated ‘day’ form. The phosphoenolpyruvate carboxylase of the CAM plant Bryophyllum fedtschenkoi can be dephosphorylated by rabbit muscle protein phosphatase type 2A but not by type 1. B. fedtschenkoi leaves contain protein phosphatase activity that can dephosphorylate phosphoenolpyruvate carboxylase. Inhibitor studies show that this enzyme is a type 2A protein phosphatase.
High affinity ryanodine binding sites in rat liver endoplasmic reticulum
Authors: Shoshan-Barmatz Varda
Published: July 2002

The binding of [3H]ryanodine to liver microsomal subfractions was investigated. The smooth microsomal membranes were enriched with ryanodine binding sites and also with a polypeptide of 360 kDa. Caffeine completely inhibited [3H]ryanodine binding. Ryanodine also affected the membrane Ca2+ permeability. At low concentrations (< 10 μM) ryanodine stimulated Ca2+ efflux and at higher concentrations (> 50 μM) it blocked Ca2+ efflux. These results suggest that hepatic microsomes contain ryanodine binding sites which can modify the membrane permeability for Ca2+.
The role of lipid peroxidation products in cumene hydroperoxide‐induced Ca2+ efflux from mitochondria
Authors: Gogvadze V.G. , Zhukova A.A.
Published: July 2002

Cumene hydroperoxide‐induced calcium release from mitochondria has been studied. Activation of lipid peroxidation by increasing concentrations of cumene hydroperoxide does not enhance calcium efflux induced by low (up to 50 μM) concentration of cumene hydroperoxide. It is concluded that cumene hydroperoxide‐induced calcium release depends mainly on processes coupled to hydroperoxide reduction by an endogenous enzyme system.
Nitroprusside stimulates the cysteine‐specific mono(ADP‐ribosylation) of glyceraldehyde‐3‐phosphate dehydrogenase from human erythrocytes
Authors: Kots Alexander Ya. , Skurat Alexander V. , Sergienko Edward A. , Bulargina Tamara V. , Severin Eugene S.
Published: July 2002

In human erythrocyte membranes incubated with [adenylate‐32P]NAD the 36 kDa protein is predominantly labeled. The labeling is greatly stimulated by nitroprusside in the presence of dithiothreitol. We have purified the 36 k Da protein and identified this modification as crysteine‐specific mono(ADP‐ribosylation) because: (i) labeling occured only when [32P]NAD was replaced by adenine [U‐14C]NAD, but not by [carbonyl‐14C]NAD; (ii) treatment of the prelabeled protein with snake venom phosphodiesterase led to releasing 5′‐[32P]AMP; (iii) the bond between the protein and the nucleotide was hydrolyzed by HgCl2, but was resistant to hydroxylamine. The 36 kDa protein reacted on Western blots with two different monoclonal antibodies (MAbs) against glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) and was immunoprecipitated by both MAbs.
A new gene of the ƒ1 operon of Y. pestis involved in the capsule biogenesis
Authors: Karlyshev A.V. , Galyov E.E. , Smirnov O.Yu. , Guzayev A.P. , Abramov V.M. , Zav'yalov V.P.
Published: July 2002

The DNA sequence determination or the ƒ1 operon between the genes encoding the F1 subunit (caf1) and chaperone‐like protein (caf1M) revealed a large open reading frame that codes for a polypeptide similar to some E. coli proteins involved in the biogenesis of fimbria. The deletion and in trans complementation analyses showed that this gene is not necessary for extracellular transport or the F1 subunit but plays a role in the capsule assembly.
Isolation of a thermostable enzyme catalyzing disulfide bond formation from the archaebacterium Sulfolobus solfataricus
Authors: Guagliardi Annamaria , Cerchia Laura , De Rosa Mario , Rossi Mosè , Bartolucci Simonetta
Published: July 2002

A disulfide bond‐forming enzyme was purified from the cytosol of the archaebacterium Sulfolobus solfataricus, strain MT‐4. The enzyme, assayed by its ability to oxidize and reactivate reductively denatured ribonuclease A, had a small molecular size and displayed a high thermostability. The N‐terminal amino acid sequence is reported.
Coordinate regulation of murein peptidase activity and AmpC β‐lactamase synthesis in Escherichia coli
Authors: Bishop Russell E. , Weiner Joel H.
Published: July 2002

In the periplasmic space of Escherichia coli, the (l)‐m‐A2pm‐(d)‐m‐A2pm peptide, the lipoprotein, and the AmpC β‐lactamase are controlled by growth rate. To explain this coordinate regulation, it is proposed that the AmpC protein functions as an ld‐endopeptidase in addition to its known function as a β‐lactamase. As ld‐peptides, dd‐peptides and β‐lactams are structurally similar, ld‐peptidases may belong to the larger family of dd‐peptidases and serine β‐lactamases. In contrast to E. coli, many related bacteria possess an inducible AmpC protein. Several gene systems necessary for AmpC induction are known to affect various aspects of peptidoglycan metabolism. It is proposed that AmpC induction occurs indirectly via a recyclable cell wall peptide.
A long‐lived state for influenza virus—erythrocyte complexes committed to fusion at neutral pH
Authors: Schoch Christian , Blumenthal Robert , Clague Michael J.
Published: July 2002

The low pH‐induced fusion of influenza virus with intact erythrocyte plasma membranes is preceded by a delay time following pH reduction, that is itself pH‐ and temperature dependent. At 37°C/pH 4.8, lipid mixing between virus and target membranes begins < 2s after pH reduction, whereas at 4°C/pH 4.8, fusion does not commence until > 10 min after pH reduction. We have found that within this time period at 4°C, a population of virus acquires the capacity to subsequently undergo fusion with high efficiency at elevated temperatures and pH 7.4. Both the kinetics and the extent of this pH 7.4 fusion depend upon the time of pre‐incubation at pH 4.8/4°C. Incubation at pH 7.4/4°C, following this pre‐incubation does not result in fusion, but the capacity to fuse at pH 7.4/37°C is retained for a time period exceeding 1 h. The longevity of this fusion committed state makes it amenable to biochemical and immunological analysis. We have shown that it is insensitive to dithiothreitol, neuraminidase and trypsin, but is incapacitated by thermolysin or protease K. We conclude that only the HA2 sub‐unit of influenza haemagglutinin is a necessary protein component of later stages of the fusion pathway.
Incorporation of N‐acyl‐2‐amino‐2‐deoxy‐hexoses into glycosphingolipids of the pheochromocytoma cell line PC 12
Authors: Kayser Holger , Geilen Christoph C. , Paul Christine , Zeitler Reinhard , Reutter Werner
Published: July 2002

The synthesis of N‐acyl‐2‐amino‐2‐deoxy‐hexoses, their metabolism and their incorporation into glycosphingolipids of rat pheochromocytoma cell line PC 12 were investigated. The data indicate that in PC 12 cells the N‐acyl‐2‐amino‐2‐deoxy‐hexoses, N‐propanoyl‐d‐glucosamine and N‐butanoyl‐d‐glucosamine are metabolized to the corresponding phosphates, and that N‐propanoyl‐d‐glucosamine is also metabolized to N‐propanoyl neuraminic acid. Using variously radiolabelled N‐acyl‐2‐amino‐2‐deoxy‐hexoses, their incorporation into glycosphingolipids was shown.
Amino acid sequence similarities between low molecular weight endo‐1,4‐β‐xylanases and family H cellulases revealed by clustering analysis
Authors: Törrönen Anneli , Kubicek Christian P. , Henrissat Bernard
Published: July 2002

The amino acid sequences of seventeen family G xylanases and the two known family H cellulases have been compared by hydrophobic cluster analysis. A weak but significant similarity was demonstrated between these two families suggesting that these enzymes share the same molecular mechanism and catalytic residues and that they have related 3D folds. The major differences were found in the N‐terminal regions.
The role of N‐glycosylation in the targeting and stability of GLUT1 glucose transporter
Authors: Asano Tomoichiro , Takata Kuniaki , Katagiri Hideki , Ishihara Hisamitsu , Inukai Kouichi , Anai Motonobu , Hirano Hiroshi , Yazaki Yoshio , Oka Yoshitomo
Published: July 2002

The cDNAs encoding the GLUT1 glucose transporter protein were altered by site‐directed mutagenesis at consensus sites for the addition of N‐linked glycosylation. These cDNAs were transfected into CHO cells with an expression vector and the subcellular distribution and stability of the expressed glycosylation‐defective GLUT1 protein were analyzed. Immunohistochemical analysis with a specific antibody demonstrated that a significant portion of glycosylation‐defective GLUT1 protein remained in the intracellular compartment. By contrast, most of the wild‐type GLUT1 proteins expressed with the same procedures resided in the plasma membranes. Metabolic labeling studies revealed that the half‐life of the glycosylation‐defective GLUT1 protein was significantly shorter than that of wild‐type GLUT1 protein. These results indicate that N‐glycosylation of the glucose transporter affects its intracellular targeting and protein stability.
Free hydroxyl radicals are formed on reaction between the neutrophil‐derived species Superoxide anion and hypochlorous acid
Authors: Candeias Luis P. , Patel Kantilal B. , Stratford Michael R.L. , Wardman Peter
Published: July 2002

Superoxide anion reacts with hypochlorous acid to yield free hydroxyl radicals, as shown by the hydroxylation of benzoate. This reaction is analogous to the Haber‐Weiss reaction but in the absence of metal ions is at least six orders of magnitude faster.
Retinal oxidase is identical to aldehyde oxidase
Authors: Tomita Shuhei , Tsujita Maki , Ichikawa Yoshiyuki
Published: July 2002

Retinal oxidase (EC 1.2.3.11) and aldehyde oxidase (EC 1.2.3.1) were compared with respect to their enzymatic and physicochemical properties. It was found that the molecular weights, subunits, optical spectra, chemical and immunological properties, cellular localization and substrate specificities of the two oxidases are identical on almost all points. The physiological function of aldehyde oxidase appears to be the synthesis of retinoic acid from retinal.
Immobilizing DNA on gold via thiol modification for atomic force microscopy imaging in buffer solutions
Authors: Hegner Martin , Wagner Peter , Semenza Giorgio
Published: July 2002

Thiols, dialkylsulfides, and dialkyldisulfides are known to be chemisorbed with high affinity on gold. We have prepared DNAs of specific length and sequence carrying thiol groups at each end. For this purpose, primers with an HS‐(CH2)6‐arm at the 5'‐end were used to amplify segments of plasmid DNA via the polymerase chain reaction. These thiolated DNAs bind strongly to the large, ultraflat Au surfaces which we have recently described [Hegner, M. et al. (1993) Surface Sci. 291, 39‐46], and can be imaged by AFM in liquids (aqueous solutions or propanol). The lengths obtained in the AFM images are consistent with the DNA being in a native B‐confonnation.
Kin recognition
Authors: Nilsson Tommy , Slusarewicz Paul , Hoe Mee H. , Warren Graham
Published: July 2002

The surprising result that the spanning domain causes retention of proteins in the Golgi stack poses the question as to the actual mechanism. Here we present a simple model that might have general applicability.
Detection of complex gangliosides in human amniotic fluid
Authors: Rueda Ricardo , Tabsh Khalil , Ladisch Stephan
Published: July 2002

Gangliosides are possibly very potent immunosuppressive molecules. Here we show that human amniotic fluid contains high concentrations of a number of previously unnoted, structurally complex and highly polar gangliosides. These unusual molecules are present early in pregnancy (first trimester), increase in concentration with gestational age, and reach maximum levels (0.8 μM) at term. Since similar gangliosides have been detected in human placenta, trophoblast, and amnion, we suggest that these molecules are shed into the amniotic fluid bathing these tissues.
Dp71, the nonmuscle product of the Duchenne muscular dystrophy gene is associated with the cell membrane
Authors: Rapaport Debora , Greenberg David S. , Tal Michael , Yaffe David , Nudel Uri
Published: July 2002

The 70.8 kDa protein, Dp71, is the major Duchenne muscular dystrophy (DMD) gene product in many nonmuscle tissues including the brain. Dp71 shares most of the C‐terminal and cysteine‐rich domains with the dystrophins but lacks the entire large rod shaped domain of spectrin‐like repeats, and the N‐terminal actin‐binding domain. The function of Dp71 is unknown. Using subcellular fractionation and immunostaining we show that Dp71 is associated with the plasma membrane. Dp71 is also associated with the plasma membrane in mdx myogenic cells transfected with a vector expressing Dp71.
A role for central A3‐adenosine receptors
Authors: Jacobson Kenneth A. , Nikodijević Olga , Shi Dan , Gallo-Rodriguez Carola , Olah Mark E. , Stiles Gary L. , Daly John W.
Published: July 2002

The behavioral effects of a selective A3 adenosine receptor agonist 3‐IB‐MECA (N
6‐(3‐iodobenzyl)‐5'‐N‐methylcarboxamidoadenosine) in mice and the localization of radioligand binding sites in mouse brain were examined. Low levels of A3 adenosine receptors were detected in various regions of the mouse brain (hippocampus, cortex, cerebellum, striatum), using a radioiodinated, high‐affinity A3‐agonist radioligand [125I]AB‐MECA (N
6‐(3‐iodo‐4‐aminobenzyl)‐5'‐N‐methylcarboxamidoadenosine). Scatchard analysis in the cerebellum showed that the K
d value for binding to A3 receptors was 1.39 ± 0.04 nM with a B
max of 14.8 ±2.1 protein. 3‐IB‐MECA at 0.1 i.p. was a locomotor depressant with > 50% reduction in activity. Although selective A1 or A2a antagonists reversed locomotor depression elicited by selective A1 or A2a agonists, respectively, the behavioral depressant effects of 3‐IB‐MECA were unaffected. 3‐IB‐MECA also caused scratching in mice, which was prevented by coadministration of the histamine antagonist cyproheptadine. The demonstration of a marked behavioral effect of A3 receptor activation suggests that the A3 receptor represents a potential new therapeutic target.
Artificial antifreeze proteins can improve NaCl tolerance when expressed in E. coli
Authors: Holmberg Niklas , Lilius Gösta , Bülow Leif
Published: July 2002

A chemically synthesized DNA fragment encoding an artificial antifreeze protein was expressed in E. coli as a translational fusion with a truncated protein A. Two constructions were made, with two and four antifreeze domains, respectively. The fusion proteins stimulated the growth of their bacterial host cells at inhibitory NaCl concentrations. The fusion protein carrying four antifreeze domains also conferred improved tolerance towards freezing.
αA‐crystallin confers cellular thermoresistance
Authors: van den Ijssel Paul R.L.A. , Overkamp Perry , Knauf Ursula , Gaestel Matthias , de Jong Wilfried W.
Published: July 2002

The bovine eye lens protein αA‐crystallin has been overexpressed both by stable transfection of HeLa cells and by transient transfection of NIH 3T3 cells. In both experimental systems αA‐crystallin overexpression results in an increased cellular thermoresistance as judged by different clonal survival assays. In contrast, similar overexpression of another stable lens protein, βB2‐crystallin, does not confer thermoresistance. These results indicate that the structural relationship of αA‐crystallin to the small heat shock proteins HSP25/27 and to αB‐crystallin is sufficient for the shared thermoprotective function of all of these molecules and strongly suggests that the chaperone‐like properties that they have in common are responsible for the conferred cellular thermoresistance.
A calcium switch for the functional coupling between α (hslo) and β subunits (KV, Caβ) of maxi K channels
Authors: Meera P , Wallner M , Jiang Z , Toro L
Published: July 2002

K
V
,
Ca

β subunit dramatically increases the apparent calcium sensitivity of the α subunit of MaxlK channels when probed in the micromolar [Ca2+]i range. Analysis in a wide range of [Ca2+]i revealed that this functional coupling is exquisitely modulated by [Ca2+]i. Ca2+ ions switch MaxiK α+β complex into a functionally coupled state at concentrations beyond resting [Ca2+]i. At [Ca2+] ≤ 100 nM, MaxiK activity becomes independent of Ca2+, is purely voltage‐activated, and its functional coupling with its β subunit is released. The functional switch develops at [Ca2+]i that occur during cellular excitation, providing the molecular basis of how MaxiK channels regulate smooth muscle excitability and neurotransmitter release.
Actomyosin‐based motility of endoplasmic reticulum and chloroplasts in Vallisneria mesophyll cells*
Authors: Liebe Susanne , Menzel Diedrik
Published: July 2002

Summary— Intracellular localization and motile behaviour of the endoplasmic reticulum (ER), plastids and mitochondria were studied in living mesophyll cells of Vallisneria using the vital fluorochrome 3,3'‐dihexyloxacarbocyanine iodide (DIOC6(3)). In quiescent cells, the ER was composed of a three‐dimensional network of tubular and lamellar elements. Chloroplasts were distributed evenly throughout the cell periphery and appeared embedded within the ER network. The ER network was relatively stationary, with the exception of rare motile episodes occurring as movement of tubular ER strands and adjacent areas of the polygonal network in localized areas of the cell. During experimental induction of streaming, most of the lamellar ER elements transformed into tubules and together with the chloroplasts they began to translocate to the anticlinal walls to establish the circular streaming around the circumference of the cell. Microwave‐accelerated fixation followed by immunofluorescence revealed an hitherto unknown phase of actin reorganization occurring within the cells and most interestingly at the surface of the chloroplasts during streaming induction. Myosin was localized in an ER‐like pattern in quiescent as well as in streaming cells, with bright fluorescent label localized on mitochondria and proplastids. In addition, myosin label appeared on the surface of the chloroplasts, preferentially in streaming mesophyll cells. Motile activities were impeded by the actin‐depolymerizing drug cytochalasin D (CD), the thioreagent N‐ethylmaleimide (NEM), and thapsigargin, an inhibitor of the ER‐Ca2+‐ATPase. These inhibitors also interfered with the integrity of actin filaments, the intracellular distribution of myosin and calcium‐homeostasis, respectively. These effects suggested an obligate association of at least one type of myosin with the membranes of ER and smaller organelles and are consistent with the appearance of another type of myosin on the chloroplast surface upon streaming induction.
The N‐terminal domain of the light‐harvesting chlorophyll a/b‐binding protein complex (LHCII) is essential for its acclimative proteolysis
Authors: Yang Dan-Hui , Paulsen Harald , Andersson Bertil
Published: July 2002

Variations in the amount of the light‐harvesting chlorophyll a/b‐binding protein complex (LHCII) is essential for regulation of the uptake of light into photosystem II. An endogenous proteolytic system was found to be involved in the degradation of LHCII in response to elevated light intensities and the proteolysis was shown to be under tight regulation [Yang, D.‐H. et al. (1998) Plant Physiol. 118, 827–834]. In this study, the substrate specificity and recognition site towards the protease were examined using reconstituted wild‐type and mutant recombinant LHCII. The results show that the LHCII apoprotein and the monomeric form of the holoprotein are targeted for proteolysis while the trimeric form is not. The N‐terminal domain of LHCII was found to be essential for recognition by the regulatory protease and the involvement of the N‐end rule pathway is discussed.
Effects of fatty acids, nucleotides and reactive oxygen species on durum wheat mitochondria
Authors: Pastore Donato , Fratianni Alessandra , Di Pede Sergio , Passarella Salvatore
Published: July 2002

Linoleic acid (LA) and other fatty acids added to respiring durum wheat mitochondria (DWM) were found to cause a remarkable membrane potential (ΔΨ) decrease, as monitored by measuring safranin fluorescence. The rate of ΔΨ decrease showed (i) saturation dependence on LA concentration; (ii) fatty acid specificity; (iii) inhibition by externally added ATP, GDP, GTP and Mg2+ and (iv) sigmoid dependence upon initial ΔΨ, thus suggesting the existence of an active plant mitochondrial uncoupling protein (PUMP) in mitochondria from monocotyledonous species (durum wheat, Triticum durum Desf.). Surprisingly, the rate of the linoleate dependent ΔΨ decrease was found to be activated by reactive oxygen species (ROS) (hydrogen peroxide and superoxide anion) and, moreover, linoleate proved to lower the mitochondrial generation of superoxide anion. These results suggest that ROS can activate PUMP, thus protecting the cell against mitochondrial ROS production.