bluuebunny/crossref_metadata_2025 huggingface dataset:
Miedo ante la muerte y calidad de vida en adultos mayores
Authors: Duran-Badillo Tirso , Maldonado Vidales Maria Aurelia , Martínez Aguilar Ma de la Luz , Gutierrez Sánchez Gustavo , Ávila Alpirez Hermelinda
Published: July 2020

Objetivo: Conocer la relación entre el miedo a la muerte y calidad de vida de los adultos mayores. Material y Método: Estudio correlacional en adultos mayores. La muestra fue de 99 adultos mayores, se utilizó la Escala original de Collet-Lester de Miedo a la Muerte y al Proceso de Morir y el Cuestionario WHOQOL-BREF. Resultados: No se encontró relación en la escala global del miedo ante la muerte y el proceso de morir con la calidad de vida. Se observó relación negativa entre el miedo a la propia muerte y la dimensión física de la calidad de vida (p<.05) y en el miedo al propio proceso de morir con la dimensión ambiental de la calidad de vida (p<.05). Se encontró relación positiva entre el miedo a la muerte de los otros y la dimensión social de la calidad de vida (p<.05). Conclusiones: A menor miedo a la propia muerte mayor calidad de vida en la dimensión física, a menor miedo al propio proceso de morir mayor calidad de vida en la dimensión ambiental y a mayor miedo a la muerte de otras personas mayor calidad de vida en la dimensión social.

Objective: Know the relationship between the fear of death and the quality of life ofolder adults.Materials and Method: Correlational study in older adults. The sample was 99 older adults. The original Collet-Lester Scale of Death Fear and the Dying Process and the WHOQOL-BREF Questionnaire were used.Results: No relationship found on the global scale of Death Fear and the Dying Process with the quality of life. A negative relationship was observed between the fear of own death and the physical dimension of the quality of life (p<.05), and the fear of the process of dying with the environmental dimension of quality of life (p<.05). Positive relationship was found between the fear of the death of others and the social dimension of quality of life (p <.05).Conclusions: A lesser fear of one's own death higher quality of life in the physical dimension, a lesser fear of the process of dying, greater quality of life in the environmental dimension and the greater the fear of the death of other people, the greater the quality of life in the social dimension.
Telecuidado como uma estratégia de saúde para a adesão do paciente com insuficiência cardíaca – revisão integrative
Authors: Guerreiro Maria Auxiliadora Ribeiro de Jesus , Sá Guerreiro Selma Petra Chaves , Alochio Kyra Vianna , Ribeiro Martha Tudrej Sattler
Published: July 2020

Objetivo: Identificar estrategias de telecuidado para pacientes con insuficiencia cardíaca que colaboran para la adhesión al tratamiento.Material y Método: Revisión integrativa de la literatura realizada en las bases de datos CINAHL, PubMed, Scielo y LILACS. La elaboración del problema fue guiada por la estrategia PICO que originó la siguiente pregunta: ¿Cuáles son las estrategias del telecuidado para los pacientes con insuficiencia cardíaca que contribuyen a su adhesión al tratamiento?Resultados: Dieciséis artículos atendieron a los criterios definidos por el estudio y por lo tanto, participaron del análisis de esta revisión.Conclusión: El telecuidado posibilita el acompañamiento de un número mayor de pacientes, contribuyendo al control de signos y síntomas de la insuficiencia cardiaca. Favorece la optimización de los tratamientos farmacológico y no farmacológico disminuyendo tasas de re-hospitalización y mortalidad.

Objective: Identify tele-monitoring strategies for patients with heart failure who collaborate for adherence when it comes to treatment.Material and Method: Integrative review of the literature carried out in the databases CINAHL, PubMed, Scielo and LILACS. The elaboration of the problem was guided by the PICO strategy that gave rise to the following question: "What are the tele-monitoring strategies for patients with heart failure that contribute to their adherence to treatment?".Results: Sixteen articles met the criteria defined by the study and, therefore, participated in the analysis of this review.Conclusion: Tele-monitoring allows the monitoring of a larger number of patients, contributing to the control of signs and symptoms of heart failure. Also, It favors the optimization of pharmacological and non-pharmacological treatments, reducing rates of rehospitalization and mortality.
Onset of neurophysin self‐association upon neurophysin/neuropeptide hormone precursor biosynthesis
Authors: Chaiken Irwin M. , Tamaoki Hidetsune , Brownstein Michael J. , Gainer Harold
Published: July 2002

The potential of the common biosynthetic precursor of neurophysin and neuropeptide hormones to self‐associate has been assessed by quantitative affinity chromatographic analysis. The precursor form, with the hormone sequence in the amino terminal region and assumed able to interact intramolecularly with the hormone binding site of the neurophysin domain of the folded precursor, exhibits an affinity for neurophysin‐agarose which is intermediate between those of unliganded neurophysin and non‐covalently hormone‐liganded neurophysin. The results lead to a prediction that neurophysin self‐association is established upon precursor synthesis and prior to limited proteolysis of the precursor to release mature neurophysin and hormone components. Such self‐association could play a role in packaging of the precursor into secretory granules and in regulating subsequent precursor processing events within the granules.
Effects of growth hormone‐releasing factor, somatostatin and dopamine on growth hormone and prolactin secretion from cultured ovine pituitary cells
Authors: Law Greg J. , Ray Keith P. , Wallis Michael
Published: July 2002

A synthetic form of human pancreatic growth hormone releasing factor (GRF‐44‐NH2) was shown to be a potent stimulator of growth hormone (GH) secretion and cellular cyclic AMP levels in cultured sheep pituitary cells. A small dose‐dependent stimulation of prolactin secretion was also observed. Somatostatin (0.5 μM) completely blocked the maximal GRF (1 nM)‐stimulated secretion without a significant effect on cyclic AMP levels. Dopamine (0.1 μM) inhibited the GRF‐elevated GH secretion by 50% and lowered cyclic AMP levels by 30%. Dopamine (0.1 μM) inhibition of basal prolactin secretion was not affected by GRF (1 nM). The data support the hypothesis that cyclic AMP is involved in the action of GRF but suggest that somatostatin can inhibit GRF‐induced secretion of GH independently of cyclic AMP.
A proposal for the structure of conotoxin ‐ a potent antagonist of the nicotinic acetylcholine receptor
Authors: Hider R.C.
Published: July 2002

Conotoxin, a thirteen residue neurotoxic peptide, is demonstrated, by circular dichroism measurements, to possess a high content of α‐hélix. The location of this helix in the sequence is severely limited by the structural preferences of individual amino acids and by the positioning of the two cystine links. Comparisons are made between the reactive site of elapidae snake venom postsynaptic neurotoxins and the surface of the conotoxin molecule.
Sequence homologies among mitochondrial DNA‐coded URF2, URF4 and URF5
Authors: Kikuno Reiko , Miyata Takashi
Published: July 2002

Mitochondrion
URF
Homology
Gene duplication
Evolution
The complete amino acid sequence of 3‐dehydroquinate synthase of Escherichia coli K 12
Authors: Millar Gary , Coggins John R.
Published: July 2002

The complete amino acid sequence of the Escherichia coli 3‐dehydroquinate synthase has been determined by a combined nucleotide and direct amino acid sequencing strategy. E. coli 3‐dehydroquinate synthase is 362 amino acids long and has a calculated M
r of 38 880. Analysis of the aroB nucleotide sequence and its 5'‐ and 3'‐flanking regions has identified the aroB promoter elements and a possible 3'‐terminator site.
1H‐NMR analysis of the sugar structures of glycoproteins as their pyridylamino derivatives
Authors: Koyama Satoshi , Daiyasu Hiromi , Hase Sumihiro , Kobayashu Yuji , Kyogoki Yoshimasa , Ikenaka Tokuji
Published: July 2002

The 1H‐NMR spectra of a series of pyridylamino (PA‐) derivatives of oligosaccharides were obtained and compared with those of the corresponding asparagine‐linked sugar chains in order to elucidate the effect of the PA‐group on the chemical shifts of structural‐reporter signals. The effects were found to be localized within the two residues from the end group. Thus, the data for asparagine‐linked chains in the literature are applicable to PA‐derivatives, so the combination of pyridylamination and NMR measurements greatly reduces the time required for structure analysis of sugar chains of glycoproteins, because the isolation and purification of the chains as PA‐derivatives are easy and efficient.
The influence of coupling transferrin to liposomes or minibeads on its uptake and fate in leukemic L2C cells
Authors: Vidal M. , Sainte-Marie J. , Philippot J.R. , Bienvenue A.
Published: July 2002

Coupling transferrin to liposomes or minibeads did not affect its uptake by L2C lymphocytes via the Tf specific receptors. The uptake kinetics of Tf conjugated with particles about 50 nm in diameter was as rapid as in the case of native Tf, and the receptors were recycled with a similar turnover time (about 15 min). Contrary to the generally accepted scheme, we found some Tf degradation provoked by cellular uptake. The degradation represented about 10% of the amount of ligand taken up by the cells. It occurred when transferrin was coupled to liposomes, but not when coupled to minibeads.
Crystallization of 70 S ribosomes and 30 S ribosomal subunits from Thermus thermophilus
Authors: Trakhanov S.D. , Yusupov M.M. , Agalarov S.C. , Garber M.B. , Ryazantsev S.N. , Tischenko S.V. , Shirokov V.A.
Published: July 2002

Well‐ordered three‐dimensional crystals of 70 S ribosomes and 30 S ribosomal subunits from extremely thermophilic bacteria Thermus thermophilus have been obtained. Positively stained thin sections of the crystals have been analyzed by electron microscopy. Redissolved crystalline ribosomes and small ribosomal subunits reveal sedimentation constants of 70 S and 30 S, respectively, and are functionally active in the poly(U)‐system.
Affinity labelling of neuronal acetylcholine receptors localizes acetylcholine‐binding sites to their β‐subunits
Authors: Whiting Paul , Lindstrom Jon
Published: July 2002

Neuronal nicotinic acetylcholine receptors (AChRs) from brains of chickens and rats consist of two types of subunits, α and β, of which a shares some antigenic determinants with α‐subunits from AChRs of electric organ and muscle [(1986) Biochemistry 25, 2082‐2093; (1986) J. Neurosci. G, 3061‐3069; (1986) Proc. Natl. Acad. Sci. USA, in press]. Here we demonstrate that after reduction with dithiothreitol (DTT) the AChRs can be specifically labelled with the acetylcholine‐binding site directed reagent 4‐(N‐maleimido)benzyltri [3H]methylammonium iodide. Labelling of the β‐subunits of neuronal nicotinic AChRs indicates that the acetylcholine‐binding site, and amino acids which may be homologous to Cys 192–193 of the α‐subunits of AChRs from electric organ and muscle, are located on the β‐subunit of neuronal AChRs. These results suggest that although neuronal nicotinic AChRs have some structural homologies to AChRs from muscle and electric organs, the AChRs from these sources are quite distant relatives in an extended gene family.
Yeast iso‐l‐cytochrome c: Genetic analysis of structural requirements
Authors: Hampsey D.Michael , Dast Goutam , Sherman Fred
Published: July 2002

We describe the use of classical and molecular genetic techniques to investigate the folding, stability, and enzymatic requirements of iso‐l‐cytochrome c from the yeast Saccharomyces cerevisiae. Interpretation of the defects associated with an extensive series of altered forms of iso‐l‐cytochrome c was facilitated by the recently resolved three dimensional structure of iso‐l‐cytochrome c [(1987) J. Mol. Biol. 199, 295–314], and by comparison with the phylogenetic series of eukaryotic cytochromes c. Residue replacements that abolish iso‐l‐cytochrome c function appear to do so by affecting either heme attachment or protein stability; no replacements that abolish electron transfer function without affecting protein structure were uncovered. Most nonfunctional forms retained at least partial covalent attachment to the heme moiety; heme attachment was abolished only by replacements of Cys19 and Cys22, which are required for thioether linkage, and His23, a heme ligand. Replacements were uncovered that retain function at varying levels, including replacements at evolutionarily conserved positions, some of which were structurally and functionally indistinguishable from wild type iso‐l‐cytochrome c.
Conformation of 1,4‐dihydropyridine — planar or boat‐like?
Authors: Hofmann H.-J. , Cimiraglia R.
Published: July 2002

The geometry of the 1,4‐dihydropyridine molecule was completely optimized employing three different ab initio basis sets (6–31 G*, 4–31 G, STO—3G). The most reliable 6–31G* basis set provides a very flat boat conformation which may easily undergo defolding to a planar ring arrangement. This result is discussed with respect to enzymatic redox cofactors and the pharmacological activity of dihydropyridine calcium antagonists.
Cyclic AMP controls the plasma membrane H+‐ATPase activity from Saccharomyces cerevisiae
Authors: Ulaszewski Stanislaw , Hilger François , Goffeau André
Published: July 2002

The thermosensitive G1‐arrested cdc35‐10 mutant from Saccharomyces cerevisiae, defective in adenylate cyclase activity, was shifted to restrictive temperature. After 1 h incubation at this temperature, the plasma membrane H+‐ATPase activity of cdc35‐10 was reduced to 50%, whereas that in mitochondria doubled. Similar data were obtained with cdc25, another thermosensitive G1‐arrested mutant modified in the cAMP pathway. In contrast, the ATPase activities of the G1‐arrested mutant cdc19, defective in pyruvate kinase, were not affected after 2 h incubation at restrictive temperature. In the double mutants cdc35‐10 cas1 and cdc25 cas1, addition of extracellular cAMP prevented the modifications of ATPase activities observed in the single mutants cdc35‐10 and cdc25. These data indicate that cAMP acts as a positive effector on the H+‐ATPase activity of plasma membranes and as a negative effector on that of mitochondria.
Sarafotoxin receptors mediate phosphoinositide hydrolysis in various rat brain regions
Authors: Kloog Y. , Ambar I. , Kochva E. , Wollberg Z. , Bdolah A. , Sokolovsky M.
Published: July 2002

Sarafotoxin‐b, a potent snake vasoconstrictor peptide homologous to the mammalian endothelial vasoconstrictor endothelin, induces phosphoinositide (PI) hydrolysis in various brain regions of the rat. Sarafotoxin‐b induced PI hydrolysis is largely independent of extracellular Ca2+ and is detected in all brain regions where toxin‐binding sites are found. These results point to the existence of a hitherto undetected neuroreceptor associated with the PI cycle.
Inhibition by glucocorticoids of tumor necrosis factor‐mediated cytotoxicity
Authors: Beyaert Rudi , Suffys Philip , Roy Frans Van , Fiers Walter
Published: July 2002

The role of the phospholipase inhibitor proteins, lipocortin‐I and ‐II, in tumor necrosis factor (TNF)‐mediated cytotoxicity against L929 fibrosarcoma cells was investigated. We previously reported that TNF‐mediated cytotoxicity was inhibited by dexamethasone (DEX), suggesting an involvement of lipocortins [1]. Now we show that, despite inhibition by DEX of TNF‐induced arachidonic acid release, DEX has no effect on the synthesis of these lipocortins. Moreover, TNF itself has no effect on the synthesis and phosphorylation of lipocortin‐I and ‐II. Also there was no difference in expression levels of lipocortin‐I and ‐II between TNF‐sensitive and ‐resistant cells. These data strongly suggest that the protective effect of DEX and other glucocorticoids is not mediated by lipocortins.
Multiple ubiquitination of calmodulin results in one polyubiquitin chain linked to calmodulin
Authors: Ziegenhagen R. , Goldberg M. , Rakutt W.-D. , Jennissen H.P.
Published: July 2002

In the presence of Ca2+ and ATP/Mg2+ mammalian calmodulin can be covalently coupled to ubiquitin by ubiquityl calmodulin synthetase (uCaMsynthetase). Three ubiquitin derivatives 125I‐CT‐ubiquitin (prepared by the chloramine‐T method), 125I‐BH‐ubiquitin (prepared by the BoltonHunter method) and methylated forms of ubiquitin were tested with native calmodulin. Alternatively native ubiquitin was tested with the Bolton‐Hunter derivative of calmodulin (125I‐BH‐calmodulin). Up to three molecules of ubiquitin can be incorporated into one molecule of calmodulin. Since both native forms of ubiquitin and calmodulin are good substrates of uCaM‐synthetase, ubiquitination is not a result of an altered conformation (i.e. denaturation) of either protein. With 125I‐BH‐calmodulin it is demonstrated that calmodulin is also present in the higher molecular weight ubiquitin conjugates. If methylated ubiquitin is employed as substrate for uCaM‐synthetase only one conjugate corresponding to the mono‐ubiquitination product of calmodulin is formed. This demonstrates that only a single lysine residue in calmodulin is conjugated to ubiquitin. All other higher molecular weight ubiquitin‐calmodulin conjugates must therefore be composed of one molecule of calmodulin to which an oligo‐ or polyubiquitin chain is linked. Since it can be shown that the mono‐ubiquitination product of calmodulin still contains ca. 1 mol calmodulin, the polyubiquitin chain is not linked to lysine 115 of calmodulin. In addition a demethylation of trimethyllysine 115 by enzymes in reticulocyte lysate or the DEAE‐enriched enzyme fraction with subsequent ubiquitination at this site of calmodulin can also be excluded.
Chromosomal reallocation of the chicken c‐myb locus and organization of 3′‐proximal coding exons
Authors: Soret Johann , Vellard Michel , Viegas-Pequignot Evani , Apiou Françoise , Dutrillaux Bernard , Perbal Bernard
Published: July 2002

In the course of our studies concerning the tissue‐specific expression of the c‐myb proto‐oncogene, we have established the nucleotide sequence of the chicken c‐myb 3′‐proximal coding exons. In situ hybridization performed with different genomic DNA probes corresponding to nearly all the c‐myb gene allowed us to localize the corresponding locus on the large acrocentric chromosome 3 in chicken. Our sequencing data also indicate that the 3′‐proximal noncoding sequences represented in c‐myb mRNA species are derived from non‐contiguous exons.
Cloning and sequencing of the inulinase gene of Kluyveromyces marxianus var. marxianus ATCC 12424
Authors: Laloux Olivier , Cassart Jean-Pol , Delcour Jean , Van Beeumen Jozef , Vandenhaute Jean
Published: July 2002

Cell wall inulinase (EC 3.2.1.7) was pirified from Kluyveromyces marxianus var. marxianus (formerly K. fragilis) and its N‐terminal 33‐amino acid sequence was established. PCR amplification of cDNA with 2 sets of degenerate primers yielded a genomic probe which was then used to screen a genomic library established in the YEp351 yeast shuttle vector. One of the selected recombinant plasmids allowed an invertase‐negative Saccharomyces cerevisiae mutant to grow on inulin. It was shown to contain an inulinase gene (INU I) encoding a 555‐amino acid precursor protein with a typical N‐terminal signal peptide. The sequence of inulinase displays a high similarity (67%) to S. cerevisiae invertase, suggesting a common evolutionary origin for yeast ß‐fructosidases with different substrate preferences.
Lipoylation of H‐protein of the glycine cleavage system The effect of site‐directed mutagenesis of amino acid residues around the lipoyllysine residue on the lipoate attachment
Authors: Fujiwara Kazuko , Okamura-Ikeda Kazuko , Motokawa Yutaro
Published: July 2002

H‐protein of the glycine cleavage system has lipoic acid on the Lys59 residue. Comparison of amino acid sequences around the lipoate attachment site of H‐proteins from various sources and acyltransferases of α‐keto acid dehydrogenase complexes indicated that Gly43, Glu56, Glu63 and Gly70 of bovine H‐protein are highly conserved among these proteins. Modification of these conserved residues by site‐directed mutagenesis indicated that Glu56 and Gly70 are important for the lipoylation of H‐protein and suggested that the proper conformation around the lipoic acid attachment site is required for the association of H‐protein to the enzyme responsible for the lipoylation.
The Pro117 to glycine mutation of staphylococcal nuclease simplifies the unfolding—folding kinetics
Authors: Kuwajima Kunihiro , Okayama Naoki , Yamamoto Kaori , Ishihara Tsuyoshi , Sugai Shintaro
Published: July 2002

Kinetics of unfolding and refolding of a staphylococcal nuclease mutant, in which Pro117 is replaced by glycine, have been investigated by stopped‐flow circular dichroism, and the results are compared with those for the wild‐type protein. In contrast to the biphasic unfolding of the wild‐type nuclease, the unfolding of the mutant is represented by a single‐phase reaction, indicating that the biphasic unfolding for the wild‐type protein is caused by cis‐trans isomerization about the prolyl peptide bond in the native state. The proline mutation also simplifies the kinetic refolding. Importance of the results in elucidating the folding mechanism is discussed.
Over‐expression of the small heat‐shock protein, hsp25, inhibits growth of Ehrlich ascites tumor cells
Authors: Knauf Ursula , Bielka Heinz , Gaestel Matthias
Published: July 2002

hsp25 is a small, growth‐related, mammalian stress protein which is highly accummulated in the stationary phase or Ehrlich ascites tumor in vivo. Ehrlich ascites cells cultivated in vitro under conditions of continuous exponential growth express hsp25 only at a low level. These cells were stably transfected with an eukaryotic expression vector carrying the coding sequence of the small heat‐shock protein, hsp25, under control of the murine metallothionein promoter. The resulting cell lines (EAT 116 and EAT 118) exhibit constitutive over‐expression of the small heat‐shock protein. hsp25, which can be further increased by induction with cadmium. Both cell lines show increased thermoresistance. The in vitro proliferation rate of the transfected cell lines EAT 116 and EAT 118 is significantly decreased depending on the degree of cadmium‐regulated over‐expression of hsp25. Furthermore, a significant delay in Ehrlich ascites tumor growth in mice using the hsp25 over‐expressing cells for primary inoculation could be demonstrated.
Zinc‐induced tyrosine phosphorylation of hippocampal p6Oc‐scr is catalyzed by another protein tyrosine kinase
Authors: Vener Alexander V. , Loeb Jacques
Published: July 2002

Tyrosine phosphorylation of p60c‐src induced by Zn2+ in rat hippocampal membranes is shown to inhibit Src tyrosine kinase activity, Zn2+ catalyzes the phosphorylation of p60c‐scr in the membranes but does not activate autophosphorylation of p60c‐scr immunoprecipitated with anti‐Scr monoclonal antibody. Moreover, the immunoprecipitated Src kinase has no Zn2+‐induced activity in phosphorylation of exogenous substrate, enolase. Cyanogen bromide cleavage of p60c‐src phosphorylated in the presence of Zn2+ yields a 4‐kDa phosphopeptide corresponding to phosphorylation of a carboxy‐terminal tyrosine residue of Src kinase. In conclusion, hippocampal membranes contain a Zn2+‐stimulated protein tyrosine kinase capable of regulating the p60c‐src activity.
Association of the wasp venom peptide mastoparan with electrically neutral lipid vesicles
Authors: Schwarz Gerhard , Blochmann Uwe
Published: July 2002

We have measured circular dichroism signals of aqueous mastoparan and mastoparan‐X when titrated with electrically neutral phospholipid unilamellar vesicles. The data could be converted into association isotherms (binding curves) under various conditions of salt content. In spite of the absence of a net charge in the lipid moiety, substantial salt effects have been observed regarding the partition coefficient of the peptide and its conformation in the associated state. These results are discussed on the basis of a general thermodynamic approach for peptide association with lipid bilayers.
The phorbol derivatives thymeleatoxin and 12‐deoxyphorbol‐13‐O‐phenylacetate‐10‐acetate cause translocation and down‐regulation of multiple protein kinase C isozymes
Authors: Roivainen Reina , Messing Robert O.
Published: July 2002

Phorbol esters such as phorbol 12‐myristate,13‐acetate (PMA) are potent activators of protein kinase C (PKC), and activate all PKC isozymes except ζ, and λ. Recently, 12‐deoxyphorbol‐13‐O‐phenylacetate‐20‐acetate (dPPA) and thymeleatoxin (Tx) were reported to selectively activate PKCβ1 (dPPA) and PKCα, ‐β, and ‐γ (Tx), but not PKCδ or PKCϵ in vitro. We examined the ability of these phorbol derivatives to translocate and down‐regulate PKC isozymes in intact cells. Our findings demonstrate that dPPA and Tx cause translocation and down‐regulation of multiple PKC isozymes, including δ and ϵ.
The MyoD binding site is dispensable for cardiac actin gene expression in the somites of later stage Xenopus embryos
Authors: Su Xi-Lin , Woodland Hugh R.
Published: July 2002

We have studied the transcription directed by the promoter of a Xenopus borealis cardiac actin gene fused to a globin reporter sequence after injection into X.laevis embryos. This promoter is known to be effective specifically in somites of neurula stage embryos, and work on a very similar X. laevis gene has indicated the importance of an upstream MyoD binding site (E box) in this process. We show that, although in the absence of the MyoD site there is a small amount of tissue‐specific expression in neurulae, transcription is abundant in the tailbud embryo a few hours later. Thus, although the E box is initially essential, other sequences must adopt the same role soon afterwards.
Structure and organization of the gene encoding a mouse mitochondrial stress‐70 protein
Authors: Michikawa Yuichi , Baba Tadashi , Arai Yuji , Sakakura Teruyo , Kusakabe Moriaki
Published: July 2002

We have previously found that an antigenic protein specific for C3H strain mouse (C3H strain‐specific antigen, CSA) is identical to peptide‐binding protein 74 (PBP74). PBP74/CSA is a novel member of the stress‐70 protein family in mitochondria. In this study, mouse genomic clones encoding PBP74/CSA, including the 5'‐ and 3'‐flanking regions of the gene, have been isolated and sequenced. The PBP74/CSA gene contained 17 exons interrupted by 16 introns. Two dimeric repeats of the consensus sequence of the heat‐shock element are present in the 5'‐flanking region of the PBP74/CSA gene. Moreover, the first intron is interrupted within the amino‐terminal leader sequence, the pattern of which is similar to that of cytochrome c
1, located in the mitochondria.
Characterization of AWN‐1 glycosylated isoforms helps define the zona pellucida and serine proteinase inhibitor‐binding region on boar spermadhesins
Authors: Calvete Juan J. , Sanz Libia , Dostàlovà Zuzana , Töpfer-Petersen Edda
Published: July 2002

Spermadhesin AWN‐1 (14 kDa) belongs to a recently described family of boar sperm surface‐associated proteins. AWN‐1 is a multifunctional protein which possesses heparin‐, serine proteinase inhibitor‐, and zona pellucida glycoprotein‐binding capability. Therefore it has been implicated in sperm capacitation and sperm‐oocyte attachment. Here, we report the characterization of 22–25 kDa isoforms of AWN‐1 isolated by heparin‐affinity chromatography, which fail to bind to zona pellucida glycoproteins or serine proteinase inhibitors. Our results show that the structure of the high and low molecular mass AWN‐1 forms differ in that the former is N‐glycosylated at Asp50 and truncated at the C‐terminus. The inability of the glycosylated AWN‐1 molecules to bind ligands is due solely to the presence of the oligosaccharide moieties, however. This indicates that glycosylation of AWN‐1 may modulate its ligand‐binding capabilities. On the other hand, the effect of glycosylation on ligand‐binding suggests that both the zona pellucida‐ and the serine proteinase inhibitor binding domain(s) may be located around the glycosylation point.
Recognition of UUN codons by two leucine tRNA species from Escherichia coli
Authors: Takai Kazuyuki , Horie Nobuyuki , Yamaizumi Ziro , Nishimura Susumu , Miyazawa Tatsuo , Yokoyama Shigeyuki
Published: July 2002

Codon recognition by Escherichia coli tRNALeu
4 and tRNALeu
5 was investigated by analysis of the competition between two aminoacyl‐tRNA species in an in vitro protein synthesis. Both tRNA species strictly obey the wobble rule when they are in competition with other tRNA species. This is probably due to the post‐transcriptional modifications at the first position of the anticodon of these tRNALeu species, supporting the proposal that the conformational rigidity of post‐transcriptionally modified pyrimidine nucleotides guarantees the correct codon recognition.
The structure of a complex between carbonic anhydrase II and a new inhibitor, trifluoromethane sulphonamide
Authors: Håkansson K. , Liljas A.
Published: July 2002

It has recently been shown that aliphatic sulphonamides are good inhibitors of carbonic anhydrase (CA) provided that the pK of the sulphonamide is low. We have determined the structure of the complex between CAII and CF3SO2NH2 by X‐ray crystallographic methods. The nitrogen of the sulphonamide is bound to the zinc ion of the enzyme in the usual manner. The other parts of the inhibitor show a different mode of binding from aromatic sulphonamides since the trifluoromethyl group is bound at the hydrophobic part of the active site instead of pointing out from the active site. It should be possible to design new inhibitors specific for the different isoenzymes, starting from the present structure.
Identification of a novel mammalian member of the NSF/CDC48p/Pas1p/TBP‐1 family through heterologous expression in yeast
Authors: Périer François , Coulter Kathryn L. , Liang Hong , Radeke Carolyn M. , Gaber Richard F. , Vandenberg Carol A.
Published: July 2002

Two suppressors of the growth deficiency of a potassium transport mutant of Saccharomyces cerevisiae were isolated from a mouse cDNA expression library. These suppressors, SKD1 and SKD2 (uppressor of
+ transport growth efect), were cDNAs encoding members of a family of ATPases involved in membrane fusion (N‐ethylmaleimide‐sensitive fusion protein, NSF), cell division cycle regulation (CDC48p), peroxisome assembly (Pas1p), and transcriptional regulation (TBP‐1). The SKD1 protein constitutes a novel member of this family with 49–58% amino acid sequence similarity with other family members, and contains a single ATP binding site. The SKD2 polypeptide is the mouse homolog of NSF.
Facilitated intramolecular electron transfer in cytochrome bo‐type ubiquinol oxidase initiated upon reaction of the fully reduced enzyme with dioxygen
Authors: Orii Yutaka , Mogi Tatsushi , Kawasaki Masato , Anraku Yasuhiro
Published: July 2002

Flow‐flash and double‐flash studies of the reaction of fully reduced bo‐type quinol oxidase with oxygen have revealed that a single turnover of the enzyme proceeds much faster than mammalian cytochrome c oxidase. Facilitated intramolecular electron transfer in the bo‐type oxidase with k ⪢ 5 × 104 s−1 at pH 7.4 and 20°C is responsible for this fast turnover. The kinetics of this reaction indicates that the oxygen reduction does not require electron exchange between quinol oxidase molecules, each having three metal centers. Thus, a bound quinol in the fully reduced enzyme is suggested to be an electron source for complete reduction of dioxygen into water supplementing electrons provided by the metal centers. A single turnover of the quinol oxidase yields a novel spectral species with a Soret maximum at 415 nm corresponding to a ‘pulsed’ state of mammalian cytochrome c oxidase.
p53 mutant His175 identified in a newly established fallopian tube carcinoma cell line secreting interleukin 6
Authors: Runnebaum Ingo B. , Tong Xiao W. , Möbus Volker J. , Kieback Dirk G. , Rosenthal Heike E. , Kreienberg Rolf
Published: July 2002

Fallopian tube carcinoma is a lethal gynecologic malignancy. Etiologic factors are unknown. No experimental data on molecular alterations exist so far. For an in vitro model, we established the permanent human tubal carcinoma cell line FT‐MZ‐1. The median doubling time was 14 days with 24.2% in S phase. A point missense mutation of the p53 tumor suppressor gene resulting in the His175 mutant was identified. Aberrant p53 protein accumulated in nucleus and cytoplasm. FT‐MZ‐1 substantially secreted interleukin 6 (Il‐6) coinciding with the inactivation of p53 as a transrepressor on the Il‐6 gene promoter.
Human‐Xenopus chimeras of Gsα reveal a new region important for its activation of adenylyl cyclase
Authors: Antonelli Marcelo , Birnbaumer Lutz , Allende Jorge E. , Olate Juan
Published: July 2002

G proteins are heterotrimeric GTPases that play a key role in signal transduction. The α subunit of Gs bound to GTP is capable of activating adenylyl cyclase. The amino acid sequences derived from two X. laevis cDNA clones that apparently code for Gsα subunits are 92% identical to those found in the short form of human Gsα. Despite this high homology, the X. laevis Gsα clones expressed in vitro, yielded a protein that are not able to activate the adenylyl cyclase present in S49 cyc− membranes in contrast with human Gsα similarly expressed. This finding suggested that the few amino acid substitutions found in the amphibian subunit are important in defining the functionality of the human Gsα. The construction of chimeras composed of different fractions of the cDNAs of the two species was adopted as an approach in determining the regions of the molecule important in its functionality in this assay. Four pairs of chimeras were constructed using reciprocal combinations of the cDNAs coding for human and Xenopus Gsα. These eight constructs were expressed in vitro and equivalent amounts of the resulting proteins were assayed in the activation of adenylyl cyclase with GTPγs and isoproterenol. The results obtained here clearly indicate that the Gα sequence that extends from amino acid 70 to 140, is important for the functionality of human Gsα in activating adenylyl cyclase.
Organisation of the murine 5‐HT3 receptor gene and assignment tohuman chromosome 11
Authors: Uetz Peter , Abdelatty Fawzy , Villarroel Alfredo , Rappold Gudrun , Weiss Birgit , Koenen Michael
Published: July 2002

We have isolated the murine gene encoding the 5‐HT3 receptor (5‐HT3R), a member of the ligand‐gated ion channels, that mediates a variety of physiological effects in central and peripheral neurons. DNA sequence analysis of the 5‐HT3R gene revealed its organisation in 9 exons distributed over approximately 12 kbp of DNA. Alternative use ofexon 9 splice acceptor sites generated two 5‐HT3R variants. The 5‐HT3R gene, whose structure is closely related to neuronal and muscle AChRα genes, as demonstrated by four common splice junctions, was localised on human chromosome 11.
Kinetic and spectral properties of pea cytosolic ascorbate peroxidase
Authors: Marquez Leah A. , Quitoriano Mannix , Zilinskas Barbara A. , Dunford H.Brian
Published: July 2002

Sufficient highly purified native pea cytosolic ascorbate peroxidase was obtained to characterize some of its kinetic and spectral properties. Its rate constant for compound I formation from reaction with H2O2 is 4.0 × 107 M−1 s−1, somewhat faster than is typical for peroxidases. Compound I has the typical optical spectrum of an iron(IV)‐porphyrin‐π‐cation radical, despite considerable homology with yeast cytochrome c peroxidase. The rate constant for compound I reduction by ascorbate is extremely fast (8.0 × 107 M−1 s−1 at pH 7.8), again in marked contrast to the behavior of the yeast enzyme. The pH‐rate profile for compound I formation indicates a pK
a value of 5.0 for a group affecting the active site reaction.
Spontaneous resolution of fetal mediastinal cystic hygroma
Authors: Wu M.‐P. , Wu R.‐C. , Lee J.‐S. , Yao W.‐J. , Kuo P.‐L.
Published: July 2002

We present a case of prenatally diagnosed mediastinal cystic hygroma with spontaneous resolution. To our knowledge, this is only the second case report of mediastinal cystic hygroma diagnosed prenatally, and the first one with spontaneous resolution perinatally. Our case shows that, in the absence of hydrops fetalis, mediastinal cystic hygroma in a fetus with normal karyotype can be associated with a normal outcome. Therefore we recommend fetal karyotyping, a careful search for other anomalies and close sonographic follow‐up in such cases.
Retention rates in two naltrexone programmes for heroin addicts in Vitoria, Spain
Authors: Gutiérrez M , Ballesteros J , González-Oliveros R , de Apodaka J Ruíz
Published: July 2002

The main finding of a former Spanish multicenter study (SMS) on the effectiveness of naltrexone maintenance in heroin addicts, was the high retention rate achieved at 24 weeks of follow-up since naltrexone induction (40%). The authors claimed this rate was one of the highest ever reported in the literature for a non-selected sample of opiate addicts and discussed the possible relevance of a set of variables — like motivations and expectations due to a new treatment — on the findings. To assess the possible effects of these variables, we have compared the retention rates in two similar naltrexone programmes. The first programme (hospital sample) included 56 individuals who were also included in the SMS where they accounted for 37% of the total sample. That programme was developed formerly to the naltrexone marketing. The second sample (ambulatory sample) included 67 individuals who were recruited at least a year apart since naltrexone marketing was approved by the Spanish Health Boards. The time-lag between the beginnig of both studies was in the range of 15 to 25 months.

The subjects in both programmes had similar distributions regarding age (p = 0.27), sex (p = 0.79), weeks on treatment after naltrexone induction (p = 0.20), and program compliance (p = 0.78). The retention rates evaluated over a period of 24 weeks were also similar (p = 0.45). The only difference appeared at 12 weeks of follow-up, showing in higher retention the hospital sample than the ambulatory sample (+23%; p < 0.05). The results are discussed according to other studies and it is concluded that findings reported in the former SMS and in this study are not unusual but compatible with recent research. Also underlined is the potential importance of naltrexone as a concomitant treatment for extinguishing high risk behaviours and the conditional stimuli associated with treatment relapse in heroin addicts.
Platelet monoamine oxidase in attempted suicide. Relations to sex, psychiatric diagnosis, mode of attempt, and previous attempts
Authors: Tripodianakis J , Markianos M , Sarantidis D , Istikoglou C , Andara A , Bistolaki E
Published: July 2002

Platelet monoamine oxidase (MAO) activities were assessed in 82 patients, 57 females and 25 males, who were admitted to the medical ward of a general hospital after a suicide attempt. The enzyme activities were compared to the activities of healthy subjects, 35 females and 26 males. In addition, MAO activities were analyzed in relation to sex, psychiatric diagnosis, mode of attempt, drugs ingested, and previous attempts. Compared to normal controls, only female patients showed lower MAO activities. In the male population, lower activities were found in the subgroup of patients who had made previous attempts. In relation to diagnosis, analysis performed in the female population revealed lower MAO activities in the dysthymic and personality disorder, and not in the adjustment or major affective disorder subgroups. MAO activities were not related to the violent mode of attempt, the type of medication used, or the score in the Beck Suicidal Intent scale. The finding of low platelet MAO activities in dysthymic disorder, indicates the need for further studies of biological variables in this underdiagnosed and undertreated diagnostic group.
Smoking and coffee intake following alcohol withdrawal in alcoholic inpatients
Authors: Aubin HJ , Tilikete S , Laureaux C , Nguyen Hac HT , Roullet-Volmi MC , Troupel S , Barrucand D
Published: July 2002

The aim of this study was to assess alcoholic inpatients' smoking and coffee intake variation following withdrawal. Only moderate smokers (less than 30 cigarettes/day) showed a significant increase of cigarette consumption after alcohol withdrawal. However, their urinary cotinine level did not vary, suggesting a behavioral, and not biological, compensation through smoking following alcohol withdrawal. Heavy smokers (30 cigarettes/day or more) showed no significant clinical or biological variation of smoking behavior. Coffee consumption increased after alcohol withdrawal in all patients, irrespective of smoking habits.
Cyclosporin A increases basal intracellular calcium and calcium responses to endothelin and vasopressin in human coronary myocytes
Authors: Frapier Jean Marc , Choby Cécile , Mangoni Matteo E. , Nargeot Joël , Albat Bernard , Richard Sylvain
Published: July 2002

Cyclosporin A (CsA) is a widely used immunosuppressive agent with severe side effects including hypertension. Here, we investigated the effects of CsA on intracellular free calcium ([Ca2+]i) and the mechanisms involved in vasoconstriction in cultured human coronary myocytes. We used the Fura‐2 technique for Ca2+ imaging. Acute application of CsA at therapeutic concentrations (0.1–10 μmol/l) had no effect. Chronic exposure to CsA (1 μmol/l) for 24 h induced a small (20 nmol/l) but highly significant increase of basal [Ca2+]i and enhanced the occurrence of spontaneous Ca2+ oscillations. Endothelin‐ and vasopressin‐induced rises of [Ca2+]i were also enhanced. The demonstration that CsA increases basal [Ca2+]i in addition to its impact on agonist receptor stimulation is of major importance for new therapeutic approaches.
Actomyosin cross‐linking by caldesmon in non‐muscle cells
Authors: Goncharova Elena A. , Shirinsky Vladimir P. , Shevelev Alexander Ya. , Marston Steven B. , Vorotnikov Alexander V.
Published: July 2002

The role of myosin‐binding in cytoskeletal arrangement of non‐muscle low molecular weight caldesmon (l‐caldesmon) was studied. The N‐terminal myosin‐binding domain of caldesmon (N152) colocalized with myosin in transiently transfected chicken fibroblasts. When added exogenously to the Triton‐insoluble cytoskeleton, N152 enhanced l‐caldesmon displacement by exogenous C‐terminal actin‐binding fragment (H1). Thus, a significant fraction of l‐caldesmon cross‐links actin and myosin. In contrast, in epithelioid HeLa cells most of l‐caldesmon was only actin‐bound as H1 alone was enough for its displacement. Phosphorylation by mitogen‐activated protein kinase reduced the capability of H1 to displace endogenous l‐caldesmon, suggesting it may represent a regulatory mechanism for actin–caldesmon interaction in vivo.
Exploring the active site of yeast xylose reductase by site‐directed mutagenesis of sequence motifs characteristic of two dehydrogenase/reductase family types
Authors: Klimacek Mario , Szekely Margarete , Grießler Richard , Nidetzky Bernd
Published: July 2002

Starting from a common tyrosine, yeast xylose reductases (XRs) contain two conserved sequence motifs corresponding to the catalytic signatures of single‐domain reductases/epimerases/dehydrogenases (Tyr
n
‐(X)3‐Lys
n+4) and aldo/keto reductases (AKRs) (Tyr
n
‐(X)28‐Lys
n+29). Tyr51, Lys55 and Lys80 of XR from Candida tenuis were replaced by site‐directed mutagenesis. The purified Tyr51→ Phe and Lys80→Ala mutants showed turnover numbers and catalytic efficiencies for NADH‐dependent reduction of D‐xylose between 2500‐ and 5000‐fold below wild‐type levels, suggesting a catalytic role of both residues. Replacing Lys55 by Asn, a substitution found in other AKRs, did not detectably affect binding of coenzymes, and enzymatic catalysis to carbonyl/alcohol interconversion. The contribution of Tyr51 to rate enhancement of aldehyde reduction conforms with expectations for the general acid catalyst of the enzymatic reaction.
A somatostatin analogue inhibits MAP kinase activation and cell proliferation in human neuroblastoma and in human small cell lung carcinoma cell lines
Authors: Cattaneo M.G. , Amoroso D. , Gussoni G. , Sanguini A.M. , Vicentini L.M.
Published: July 2002

Somatostatin possesses antisecretory and antiproliferative activity on some human tumors. We herein report that, in a human neuroblastoma cell line, the somatostatin analogue BIM 23014 inhibited mitogen‐activated protein (MAP) kinase activity stimulated by either insulin‐like growth factor‐1, whose receptor bears a tyrosine kinase, or carbachol, which acts at a G‐protein coupled receptor. In a human small cell lung carcinoma line BIM inhibited serum‐stimulated MAP kinase activation. These inhibitory actions occur in a dose range quite similar to that observed for suppression of proliferation induced by the analogue in the same cell lines. The decrease in cAMP elicited by the analogue in the two cell lines is not responsible for its inhibitory action on MAP kinase and cell growth. Moreover, the analogue did not modify intracellular [Ca2+] and pH. An involvement of a phosphatase activity is suggested.
N‐like intermediate in the photocycle of the acid purple form of bacteriorhodopsin
Authors: Tokaji Zsolt , Dér András , Keszthelyi Lajos
Published: July 2002

© 1997 Federation of European Biochemical Societies.
Massive glycation of protein HC, a low molecular weight lipocalin, in non‐diabetic individuals
Authors: Bonay Pedro , Solı́s Juan , de la Calle Hermenegildo , Fresno Manuel , Grubb Anders , Méndez Enrique
Published: July 2002

Human protein HC is a member of the lipocalin superfamily with unique properties since it carries a covalently bound fluorescent chromophore mediating the linkage of the major part of protein HC to several plasma proteins, with IgA as the dominating complex partner. Native protein HC displays characteristic absorption and fluorescence spectra similar to those of glycated proteins with advanced glycosylation end products (AGEs). In vitro glycation of protein HC induces the formation of fibril aggregates with a corresponding increase of absorption in the visible region of the spectrum. Boronate‐affinity chromatography and a novel galactosyltransferase assay indicate that protein HC is modified with residues of glucose exposed in a terminal non‐reducing position which is typical of glycated proteins. The glycation level of several isolated batches of protein HC as measured by both assays was around 35%, which represents the highest level described for human plasma‐derived proteins from healthy individuals.
Kinetic study of penicillin acylase from Alcaligenes faecalis
Authors: Švedas Vytas , Guranda Dorel , van Langen Luuk , van Rantwijk Fred , Sheldon Roger
Published: July 2002

Penicillin acylase from Alcaligenes faecalis has a very high affinity for both natural (benzylpenicillin, K
m=0.0042 mM) and colorimetric (6‐nitro‐3‐phenylacetamidobenzoic acid, K
m=0.0045 mM) substrates as well as the product of their hydrolysis, phenylacetic acid (K
i=0.016 mM). The enzyme is partially inhibited at high benzylpenicillin concentrations but the triple SES complex formed still retains 43% of the maximal catalytic activity; the affinity of benzylpenicillin for the second substrate molecule binding site is much lower (K
S′=54 mM) than for the first one. Phenylmethylsulfonyl fluoride was shown to be a very effective irreversible inhibitor, completely inactivating the penicillin acylase from A. faecalis in a few minutes at micromolar concentrations; this compound was used for enzyme active site titration. The absolute values of the determined kinetic parameters for enzymatic hydrolysis of 6‐nitro‐3‐phenylacetamidobenzoic acid (k
cat=95 s−1 and k
cat/K
m=2.1×10−7 M−1 s−1) and benzylpenicillin (k
cat=54 s−1 and k
cat/K
m=1.3×10−7 M−1 s−1) by penicillin acylase from A. faecalis were shown to be highest of all the enzymes of this family that have so far been studied.