bluuebunny/crossref_metadata_2025 huggingface dataset:
Rock y violencia en España (1956-1964). Los casos de Madrid y Barcelona
Authors: Rodríguez Centeno Juan Carlos
Published: December 2020

El rock and roll llegó a España a finales de la década de 1950. La prensa franquista anunció su llegada destacando una de las características que acompañaban al nuevo fenómeno musical y socio-cultural que había triunfado unos años antes en muchos países del mundo: los brotes de violencia que se producían en los conciertos, las salas de baile, los cines, los teatros e incluso las calles. Estas manifestaciones violentas estaban protagonizadas por bandas juveniles que durante los años cincuenta aparecieron en Estados Unidos y Europa Occidental y que serían conocidas posteriormente como tribus urbanas. Los incidentes producidos durante la actuación de Bill Haley en Barcelona, en 1958, revelaron que en la España franquista también existían bandas juveniles seguidoras del rock, que crecieron en número durante la primera mitad de la década de los sesenta, y que la violencia, al igual que ocurría con sus coetáneos foráneos, también era una seña de identidad. Este trabajo se centra en la actividad de estas bandas en Madrid y Barcelona, su relación con la música rock y la visión que de ellas ofrecieron los medios de comunicación
The differential contribution of arginase and transamidinase to ornithine biosynthesis in two achromic human melanoma cell lines
Authors: Thomasset Nicole , Quash Gérard A. , Doré Jean-François
Published: July 2002

Cellular ornithine biosynthesis could be expected to play a significant role in putrescine formation and hence in growth. Two enzymes are involved in ornithine biosynthesis: arginase and transamidinase. These enzyme activities were studied in two human melanoma cell lines differing in their K
m of diamine oxidase for putrescine and in their tumorigenicity in nude mice. Arginase activity accounts for the majority of ornithine formed in the highly tumorigenic cell line, while the majority of ornithine is derived from transamidinase action in the poorly tumorigenic cell line, with concomitant formation of methyl guanidine, a potent inhibitor of diamine oxidase.
Decrease in uH2A (protein A24) of a mouse temperature‐sensitive mutant
Authors: Matsumoto Yoh-ichi , Yasuda Hideyo , Marunouchi Tohru , Yamada Masa-atsu
Published: July 2002

ts85 cell is a temperature‐sensitive mutant of cell cycle, and chromosomal protein uH2A of this mutant disappears at the non‐permissive temperature. uH2A in nucleosomes is thought to be synthesized or degradated as follows. H2A + Ubiquitin ⇆ uH2A. Up to date, the degradation of uH2A was shown to be catalyzed by uH2A lyase, however no enzymes (factors) concerning its synthesis have been elucidated. Here, we show that ATP is prerequisite for the synthesis of uH2A, and that the disappearance of uH2A at the non‐permissive temperature may be due to a reduction in the rate of synthesis rather than an increase in the rate of its degradation.
The purification of 5‐enolpyruvylshikimate 3‐phosphate synthase from an overproducing strain of Escherichia coli
Authors: Duncan Kenneth , Lewendon Ann , Coggins John R.
Published: July 2002

The Escherichia coli aroA gene which codes for the enzyme 5‐enolpyruvylshikimate 3‐phosphate synthase (EPSP synthase) has been cloned from the λ‐transducing bacteriophage λpserC. The gene has been located on a 4.7 kilobase pair PstI DNA fragment which has been inserted into the multiple copy plasmid pAT153. E. coli cells transformed with this recombinant plasmid overproduce EPSP synthase 100‐fold. A simple method for the purification of homogeneous enzyme in milligram quantities has been devised. The resulting enzyme is indistinguishable from enzyme isolated from untransformed E. coli.
Catabolism of capped (3′‐5′)‐ and (2′‐5′)‐adenylates in rat liver nuclei
Authors: Michels Winfried , Schlimme Eckhard
Published: July 2002

We describe studies concerning the ability of a nuclear dinucleoside triphosphatase to act as a decapping enzyme in RNA catabolism. The enzymatic release of GMP from the Gp3A moiety was determined in the capped RNA model compounds GP3A3′pA, Gp3A3′pA‐isoprop and Gp3A2′pA in isolated rat liver nuclei; i.e., in the environment in which the dinucleoside triphosphatase operates in vivo. The Gp3A cap moiety is hydrolyzed in (3′‐5′) linked nucleotides only, whereas an extension of the Gp3A in the 2′‐direction prevents the nuclear triphosphatase to operate.
Similarity between the bacterial histone‐like protein HU and a protein from spinach chloroplasts
Authors: Briat Jean-François , Letoffe Sylvie , Mache Régis , Rouviere-Yaniv Josette
Published: July 2002

The histone‐like protein HU isolated from E. coli is well conserved in prokaryotes. We show here that antiserum prepared against bacterial HU cross‐reacts with a DNA‐binding protein co‐sedimenting with the nucleoid of spinach chloroplasts. Antibodies prepared against cyanobacterial HU are more reactive than those raised against E. coli HU. The chloroplast protein resembles HU in that both appear to be composed of two related subunits.
Mechanism of foetal wastage following immunoneutralization of riboflavin carrier protein in the pregnant rat: disturbances in flavin coenzyme levels
Authors: Krishnamurthy Kavita , Surolia Namita , Adiga P.Radhakantha
Published: July 2002

Immunoneutralization of maternal RCP results in a >90% decrease in the content and the incorporation of [2‐14C]riboflavin into embryonic FAD as well as a percentage redistribution of both embryonic FMN and riboflavin. This is unaccompanied by any discernible changes in flavin distribution pattern in the maternal liver. Embryonic α‐glycerophosphate dehydrogenase and NADPH‐cytochrome c reductase register significant decreases in activities in the RCP antiserum‐treated rats. These alterations readily explain the arrest of foetal growth culminating in pregnancy termination in the antiserum‐treated animals.
Vitamin K‐dependent carboxylation: inhibition by a peptide containing 4‐methylene glutamic acid
Authors: Guibé Eryka , Maréchal Paulette Decottignies-Le , Le Maréchal Pierre , Azerad Robert
Published: July 2002

Vitamin K
Carboxylation
4‐Methylene glutamic acid
γ‐Carboxyglutamic acid
Amino acid sequence analysis of the glycopeptides from human complement component C3
Authors: Welinder Karen G. , Svendsen Allan
Published: July 2002

Human complement component C3 has been cleaved completely by trypsin in the presence of 2‐propanol. The hydrolysate was fully solubilized and fractionated by reversed‐phase HPLC. Two peptides only contained glucosamine, Unambiguous sequence analyses identified Asn‐63 of the β‐chain and Asn‐268 of the α‐chain as the sites of carbohydrate attachment. A third potential Asn‐Xaa‐Thr/Ser glycosylation site, Asn‐946 of the α‐chain, is not modified. The different states of glycosylation of the three sites cannot be explained by differences in exposure or secondary structure. All three are predicted reverse turn.
Porcine tissue plasminogen activator
Authors: Pohl Gunnar , Jörnvall Hans , Kok Preben , Wallén Per
Published: July 2002

Tissue plasminogen activator was purified in high yield from pig heart by immunoaffinity chromatography and characterized by analysis of the glycosylation pattern and the N‐terminal amino acid sequence. Comparisons with the human enzyme reveals residue exchanges in the A‐chain at positions 3 (porcine Arg/human Gin) and 5 (Thr/Ile), and in the B‐chain at positions 6 (Tyr/Phe), 10 (Thr/Ala) and 20 (Val/Ala). The glycosylation pattern for the porcine activator was determined by endoglycosidase treatment followed by gel electrophoresis. The A‐chain contains a single high‐mannose type of JV‐linked glycan structure and the B‐chain contains a complex type of oligosaccharide. A similar but not identical pattern has been observed for the human activator, purified from melanoma cells.
Molecular cloning of the avian β‐nerve growth factor gene: transcription in brain
Authors: Wion Didier , Perret Christine , Fréchin Nancy , Keller Angelica , Béhar Ghislaine , Brachet Philippe , Auffray Charles
Published: July 2002

(Brain)
Gene
Nerve growth factor
Nucleotide sequence
Nucleotide sequence of cDNA clones encoding the complete ‘23 kDa’ and ‘16 kDa’ precursor proteins associated with the photosynthetic oxygen‐evolving complex from spinach
Authors: Jansen T. , Rother C. , Steppuhn J. , Reinke H. , Beyreuther K. , Jansson C. , Andersson B. , Herrmann R.G.
Published: July 2002

We present the nucleotide sequences and derived amino acid sequences of cDNAs that encode the complete precursors of the extrinsic ‘23 kDa’ and ‘16 kDa’ polypeptides associated with the photosynthetic oxygen‐evolving complex from spinach. The luminal proteins consist of 267/186 (precursor/mature 23 kDa protein) and 232/149 (16 kDa polypeptide) amino acid residues corresponding to molecular masses of 28.5/20.2 and 24.9/16.5 kDa, respectively. Secondary structure predictions disclose epitopes that are potential candidates for two‐step processing of the precursors during import and intraorganelle routing as well as for calcium sequestering, chloride binding and subunit/subunit interaction.
Characterization of a heterogeneous camel milk whey non‐casein protein
Authors: Beg Obaid Ullah , Bahr-Lindström Hedvig von , Zaidi Zafar H. , Jörnvall Hans
Published: July 2002

A milk protein, occurring in the whey fraction, has been characterized from camel milk. Determination of the primary structure reveals the existence of two related types of chain with residue differences in at least the N‐terminal region. A fragment representing an N‐terminal part of the protein was also recovered (heterogeneous at the same positions). The absence of cysteine residues in the protein shows that no disulphide bridges are present. The pattern of fragments and a parent protein resembles that for casein and its fragments, showing that fragments and a multiplicity of forms may be typical for different milk proteins.
Evidence for interaction between smooth muscle tropomyosin and caldesmon
Authors: Graceffa Philip
Published: July 2002

The viscosity of chicken gizzard smooth muscle tropomyosin is enhanced 4.7‐fold in the absence of salt and 1.43‐fold in 0.1 M salt by the presence of stoichiometric amounts of gizzard caldesmon, indicating that the two proteins interact under these conditions. Since the thin filament regulation of smooth muscle contraction by caldesmon requires the presence of tropomyosin, these results suggest that the direct interaction between tropomyosin and caldesmon on the thin filament plays a role in this regulation.
Localization of the pro‐sequence within the total deduced primary structure of human β‐hexosaminidase B
Authors: Stirling John , Leung Amy , Gravel Roy A. , Mahuran Don
Published: July 2002

The β subunit of β‐hexosaminidase (β‐N‐acetylhexosaminidase, EC 3.2.1.52) is synthesized in the rough endoplasmic reticulum as a prepropolypeptide. After the loss of the signal peptide and formation of an enzymatically active dimer, the pro‐enzyme is either secreted from the cell or transported into the lysosome for processing to its mature form. In order to characterize the early posttranslational events we have purified nearly 1 mg of pro‐hexosaminidase B from the NH4Cl containing medium of fibroblasts derived from a patient with the infantile form of Tay‐Sachs disease. The partial N‐terminal sequence was mapped to a position 42 residues C‐terminal to the first in‐frame ATG (Met residue) and 79 residues N‐terminal to the known mature N‐terminus. This position corresponds to that predicted for the cleavage of a 17 amino acid signal peptide generated through the use of the third rather than the first in‐frame ATG as the initiation site for protein synthesis.
Polypeptide composition of light‐harvesting complexes from some brown algae and diatoms
Authors: Caron L. , Remy R. , Berkaloff C.
Published: July 2002

The polypeptide composition of some Chromophyte light‐harvesting complexes was investigated by SDS‐PAGE and compared to LHCP of higher plants. According to the species, one or two major polypeptides were found in the range 17–25 kDa, which is noticeably lower than for higher plant LHCP polypeptides. Evidence is provided for three species LH polypeptides possessing different molecular masses that they all possess some immunological analogy with a maize LHCP. In addition, Fucus serratus LH was proved to be able to phosphorylate.
An endogenous ligand for the central sulfonylurea receptor
Authors: Virsolvy-Vergine A. , Brück M. , Dufour M. , Cauvin A. , Lupo B. , Bataille D.
Published: July 2002

An endogenous ligand for the rat central sulfonylurea receptor has been evidenced in the rat central nervous system. The characteristics of this ligand (extractibility, non‐dialysability, chromatographic behaviour on different media, sensitivity to proteases) indicate that it is a neutral to slightly basic peptide.
Characterization of low molecular mass proteins of photosystem II by N‐terminal sequencing
Authors: Schröder Wolfgang P. , Henrysson Tomas , Åkerlund Hans-Erik
Published: July 2002

The N‐terminal amino acid sequence of four chloroplast proteins with the apparent molecular masses of 3.7, 6.5, 7 and 8 kDa has been determined. Two of the proteins (6.5 and 7 kDa) turned out to have the same amino acid sequence. This sequence, and the sequence of the 3.7 kDa protein, did not correspond to any of the known chloroplast protein sequences, or to any of the open reading frames of the chloroplast genome. The 8 kDa protein, which could be distinguished from the cytochrome b‐559 band only at increased urea concentrations, was partially purified and found to be a degradation product of the extrinsic 16 kDa protein.
Prosomes discriminate between mRNA of adenovirus‐infected and uninfected HeLa cells
Authors: Horsch Andrea , de Sa Cezar Martins , Dineva Bistra , Spindler Ernst , Schmid Hans-Peter
Published: July 2002

Prosomes are small cytoplasmic RNP complexes associated with repressed mRNA. In in vitro translation, they discriminate between the mRNA of adenovirus‐infected HeLa cells and those of uninfected cells grown under normal conditions. Prosomes as well as their RNA constituents interact much more strongly with poly(A)+ mRNA of infected cells and inhibit their translation in vitro preferentially. A possible role of prosomes in the differential regulation of translation is discussed.
An in vitro demonstration of peroxisome proliferation and increase in peroxisomal β‐oxidation system mRNAs in cultured rat hepatocytes treated with ciprofibrate
Authors: Thangada Shobha , Alvares Keith , Mangino Mario , Usman Mohammed I. , Rao M.Sambasiva , Reddy Janardan K.
Published: July 2002

Using the normal adult rat hepatocytes, plated on rat tail collagen‐coated dishes and fed a chemically defined medium, we demonstrate here that ciprofibrate at 0.1 mM concentration, increases significantly the mRNA levels of fatty acyl‐CoA oxidase, enoyl‐CoA hydratase/3‐hydroxyacyl‐CoA dehydrogenase bifunctional protein, and thiolase (the three enzymes of the β‐oxidation system), and causes peroxisome proliferation. Increase in mRNA levels of these genes was evident within 1 h and was maximal 24 h after the addition of ciprofibrate. In hepatocytes cultured in the absence of ciprofibrate, the basal levels of these enzymes were low and further declined with time. Concomitant treatment of hepatocytes with cycloheximide did not inhibit or superinduce the mRNA levels, indicating that this induction may represent a primary (direct) effect of this compound on the expression of these genes and does not apparently involve short‐lived repressor protein(s).
Substrate specificity of wheat embryo calcium‐dependent protein kinase
Authors: Polya Gideon M. , Morrice Nick , Wettenhall Richard E.H.
Published: July 2002

Wheat embryo Ca2+ ‐dependent protein kinase (CDPK) phosphorylates a variety of synthetic peptides having a Basic‐X‐X‐Ser sequence but peptides with a Basic‐Basic‐X‐Ser(Thr) sequence are relatively poor substrates. Wheat germ CDPK phosphorylates a variety of proteins of which histone H1 and bovine serum albumin are among the better substrates. A single phosphorylated tryptic peptide was purified from bovine histone H1 phosphorylated by wheat embryo CDPK and subjected to Edman degradation yielding the sequence Gly97‐Thr‐Gly‐Ala‐Ser‐Gly‐Ser(PO4)‐Phe‐Lys105. Ser103 on bovine histone H1 is also the residue phosphorylated by rat brain protein kinase C.
Interleukin 1‐ and tumor necrosis factor‐stimulation of prostaglandin E2 synthesis in MDCK cells, and potentiation of this effect by cycloheximide
Authors: Leighton Jonathan D. , Pfeilschifter Josef
Published: July 2002

The effects of interleukin (IL)‐ lα, IL‐ 1β and TNFα on prostaglandin‐E2 synthesis in Madin‐Darby canine kidney (MDCK) cells were investigated. IL‐lβ time‐ and dose‐dependently stimulated prostaglandin‐E2 synthesis. While TNFα produced a comparatively small but significant stimulation of PGE2 release, coincubation of IL‐lβ with TNFα produced a marked synergistic stimulation of PGE2 release. The effect of IL‐lβ and of IL‐1β and TNFα was apparent as early as after 2 h of incubation. The enhanced PGE2 synthesis was inhibited by indomethacin as well as actinomycin D, while cycloheximide surprisingly potentiated PGE2 synthesis in response to both IL‐1β and TNFα. IL‐1α alone was ineffective in stimulating a significant release of PGE2 at concentrations as high as 10 nM. However, it also showed a marked synergistic interaction with TNFα in stimulating PGE2 release.
Uniform labeling of a recombinant antibody Fv‐fragment with 15N and 13C for heteronuclear NMR spectroscopy
Authors: Riechmann Lutz , Cavanagh John , McManus Siobhan
Published: July 2002

The expression of functional antibody fragments in Escherichia coli enables a detailed analysis by NMR spectroscopy. This is demonstrated with the uniform labeling of an Fv‐fragment (25 kDa) comprising the antigen binding site of an anitbody against 2‐phenyloxazolone with 15N and 13C. The antigen‐complexed Fv‐fragment was analysed for a potential assignment by heteronuclear multi‐dimensional NMR spectroscopy. For almost all backbone amides 15N/1H crosspeaks and for 80% of them TOCSY crosspeaks were observed. In a 13C‐edited‐HCCH‐2D experiment 17 out of 18 threonine spin‐systems were identified. Thus detailed assignments are possible, but some amino acid specific labeling in addition to uniform labeling will be required for complete assignments of Fv‐fragments.
Location of dinucleoside triphosphatase in the matrix space of rat liver mitochondria
Authors: Bernet Diego , Pinto Rosa Maria , Sillero Antonio , Cameselle José Carlos
Published: July 2002

The submitochondrial location of dinucleoside triphosphatase (EC 3.6.1.29). previously shown to be in part associated with mitochondria, has been studied in rat liver. The precipitability and latency of activity in organelle suspensions, and the profile of solubilization by digitonin, were like those of the matrix space marker glutamate dehydrogenase, and differed from those other submitochondrial fractions. This, and the synthesis of diadenosine polyphosphates by mitochondrial aminoacyl‐tRNA synthetases, suggest the occurrence of a pathway for the intramitochondrial turnover of diadenosine 5′,5‴‐P
1,P
3‐triphosphate (Ap2A).
Membrane fusion during infection of Escherichia coli cells by phage T4
Authors: Tarahovsky Y.S. , Khusainov A.A. , Deev A.A. , Kim Y.V.
Published: July 2002

Phage T4 infection of Escherichia coli was studied by thin‐section and freeze‐fracture electron microscopy. It was found that phage T4 induces the formation of a bridge between the outer and inner membranes of E coli. A membrane fusion during the infection is suggested.
Stimulation of DNA synthesis in Jurkat cells by synergistic action between adenine and guanine nucleotides
Authors: Tokumitsu Yukiko , Yanagawa Yoshiki , Nomura Yasuyuki
Published: July 2002

P2‐purinoceptor agonists stimulated the DNA synthesis of Jurkat cells via a pathway independent of cAMP and intracellular free calcium. The response was greatly enhanced by the synergistic action between adenine and guanine nucleotides, suggesting that binding sites of these nucleotides are different from each other, and the proliferation is stimulated by a novel interaction between adenine and guanine nucleotide receptors. The stimulatory effects of P2‐agonists on proliferation were completely abolished by cholera toxin and attenuated by pertussis toxin, which suggests that substrates for cholera toxin and pertussis toxin are involved in the proliferative pathways associated with P2‐purinoceptors.
Purification and subunit composition of a GTP‐binding protein from maize root plasma membranes
Authors: Bilushi Sevo V. , Shebunin Alexander G. , Babakov Alexey V.
Published: July 2002

When frozen plasma membranes isolated from maize seedling roots are thawed, a significant portion of GTP‐binding activity goes into solution. The GTP‐binding protein was purified by ion exchange chromatography on Mono‐Q and gel filtration on Superose 6. Its molecular weight was estimated at 61 kDa by gel filtration. The same molecular weight was obtained upon solubilization of the GTP‐binding protein with cholic acid followed by gel filtration in the presence of this detergent. SDS‐PAGE demonstrated that the isolated GTP‐binding protein consists of two types of subunit of molecular weights 27 kDa and 34 kDa.
A lipoxygenase is the main lipid body protein in cucumber and soybean cotyledons during the stage of triglyceride mobilization
Authors: Feußner Ivo , Kindl Helmut
Published: July 2002

The 90‐kDa lipid body protein characterized earlier by its high expression during the stage of fat degradation was identified as a form of lipoxygenase. This organelle form was compared with lipoxygenase species purified from the cytosol. It is further shown that the antibodies raised against the lipid body membrane lipoxygenase from cucumber cotyledons cross‐react with both cytosolic and lipid body lipoxygenase from soybean.
Identification and solubilization of a signal peptidase from the phototrophic bacterium Rhodobacter capsulatus
Authors: Wieseler Beate , Schiltz Emile , Müller Matthias
Published: July 2002

In Gram‐negative bacteria, exported proteins are synthesized with an amino‐terminal signal sequence which is cleaved off by the signal peptidase during, or shortly after the translocation process. Here, we report the identification and solubilization of a signal peptidase from the phototrophic bacterium Rhodobacter capsulatus which cleaves homologous and heterologous precursor proteins at the authentic cleavage site. This signal peptidase is the first identified component of the R. capsulatus protein export machinery.
Design, synthesis and solution structure of a renin inhibitor Structural constraints from NOE, and homonuclear and heteronuclear coupling constants combined with distance geometry calculations
Authors: Reily Michael D. , Thanabal Venkataraman , Lunney Elizabeth A. , Repine Joseph T. , Humblet Christine C. , Wagner Gerhard
Published: July 2002

A macrocyclic renin inhibitor was designed using molecular modeling and a model of human renin. The synthesized molecule displayed poor binding affinity. To investigate the reasons for the observed inactivity, the structure of the compound has been studied by NMR spectroscopy and distance geometry. Structural constraints for distance geometry calculations were derived from nuclear Overhauser effects and homonuclear and heteronuclear three bond coupling constants. Homonuclear coupling constants were measured directly from the resolution‐enhanced proton spectra and heteronuclear coupling constants were measured from the natural abundance 15N‐ and 13C‐edited TOCSY experiments. One φ angle was determined uniquely by this method and two were reduced to two possible values each. By using a statistical analysis of 400 structures generated with distance geometry, two families of structures were found to be consistent with the NMR data. The solution structures so derived were different from the originally designed structure, including an internal hydrogen bond. This provides a possible explanation for the lack of effectiveness of this compound.
Interaction between d‐glyceraldehyde‐3‐phosphate dehydrogenase and 3‐phosphoglycerate kinase and its functional consequences
Authors: Khoroshilova Natalia A. , Muronetz Vladimir I. , Nagradova Natalia K.
Published: July 2002

E. Coli
d‐glyceraldehyde‐3‐phosphate dehydrogenase covalently bound to Sepharose was shown to form a complex with soluble E. coli 3‐phosphoglycerate kinase with a stoichiometry of 1.77±0.61 kinase molecules per tetramer of the dehydrogenase and an apparent K
d of 1.03±0.68μM (10 mM sodium phosphate, 0.15 M NaCl). No interaction was detected between E. coli
d‐glyceraldehyde‐3‐phosphate dehydrogenase and rabbit muscle 3‐phosphoglycerate kinase. The species‐specificity of the bienzyme association made it possible to develop a kinetic approach to demonstrate the functionally significant interaction between E. coli
d‐glyceraldehyde‐3‐phosphate dehydrogenase and E. coli 3‐phosphoglycerate kinase, which consists of an increase in steady‐state rate of the coupled reaction.
Interaction between oleic acid‐containing pH‐sensitive and plain liposomes Fluorescent spectroscopy studies
Authors: Torchilin V.P. , Lukyanov A.N. , Klibanov A.L. , Omelyanenko V.G.
Published: July 2002

The energy transfer method has been applied to study the interaction between pH‐sensitive liposomes (phosphatidyl ethanolamine/oleic acid/cholesterol, 4:2:4 molar ratio) and plain liposomes (phosphatidyl choline/phosphatidyl ethanolamine/cholesterol, 4:2:3 molar ratio). It was shown that a slow fusion process occurs between two types of liposomes. Also, the transfer of oleic acid from pH‐sensitive liposomes to plain liposomes takes place. This transfer results in the increased permeability of both pH‐sensitive and plain liposomes, facilitating the release of liposome‐entrapped fluorescent dye. The data obtained were used for a possible explanation of the mechanism of intracytoplasmic drug delivery by pH‐sensitive oleic acid‐containing liposomes.
Complex formation between glutamyl‐tRNA synthetase and glutamyl‐ tRNA reductase during the tRNA‐dependent synthesis of 5‐aminolevulinic acid in Chlamydomonas reinhardtii
Authors: Jahn Dieter
Published: July 2002

The formation of a stable complex between glutamyl‐tRNA synthetase and the first enzyme of chlorophyll biosynthesis glutamyl‐tRNA reductase was investigated in the green alga Chlamydomonas reinhardtii. Apparently homogenous enzymes, purified after previously established purification protocols were incubated in various combinations with ATP, glutamate, tRNAGlu and NADPH and formed complexes were isolated via glycerol gradient centrifugation. Stable complexes were detected only after the preincubation of glutamyl‐tRNA synthetase, glutamyl‐tRNA reductase with either glutamyl‐tRNA or free tRNAGlu, ATP and glutamate, indicating the obligatory requirement of aminoacylated tRNAGlu for complex formation. The further addition of NADPH resulting in the reduction of the tRNA‐bound glutamate to glutamate 1‐semialdehyde led to the dissociation of the complex. Once complexed to the two enzymes tRNAGlu was found to be partially protected from ribonuclease digestion. Escherichia coli, Bacillus subtilis and Synechocystis 6803 tRNAGlu were efficiently incorporated into the protein—RNA complex. The detected complexes provide the chloroplast with a potential channeling mechanism for Glu‐tRNAGlu into chlorophyll synthesis in order to compete with the chloroplastic protein synthesis machinery.
New virus‐specific T‐helper epitopes of foot‐and‐mouth disease viral VP1 protein
Authors: Volpina Olga M. , Gelfanov Vasily M. , Yarov Aleksey V. , Surovoy Andrey Yu. , Chepurkin Anatoly V. , Ivanov Vadim T.
Published: July 2002

Immunogenicity studies of synthetic peptides from different regions of VP1 protein of foot‐and‐mouth disease virus strain A22 revealed the following active fragments: 39–61, 50–69, 135–159, 175–189, 170–189 and 197–213. Testing of virus neutralizing antibody production in rabbits primed by peptides and then inoculated by the virus showed that only peptides 135–159 and 170–189 were able to induce the functional T‐cell helper activity. Localization of virus‐specific T‐cell recognition sites in sequences 135–159 and 170–189 was confirmed in in vitro recognition experiments of the virus by peptide activated mice lymphocytes.
Molecular cloning of a cDNA encoding calmodulin from Neurospora crassa
Authors: Capelli Nicolas , van Tuinen Diederik , Perez Ruben Ortega , Arrighi Jean-F. , Turian Gilbert
Published: July 2002

A full‐length cDNA encoding Neurospora crassa calmodulin was isolated from λZAP II cDNA expression library. The open reading frame encodes a protein of 148 amino acid residues with a calculated M
r, of 16,865 Da. Using site‐directed mutagenesis, the complete cDNA was ligated into a trc promoter‐regulated bacterial expression vector to allow expression of N. crassa calmodulin in E. coli. The expressed protein was found to be identical to the native protein on the basis of some of its biochemical properties. Finally, Southern analysis of restriction digests of genomic DNA indicates that calmodulin is encoded by a single‐copy gene.
Unique reaction of a barley peroxidase with hydrogen peroxide
Authors: Rasmussen C.B. , Bakovic M. , Welinder K.G. , Dunford H.B.
Published: July 2002

The reaction of barley peroxidase BP 1 with H2O2 is markedly different from that of other peroxidases. Saturation kinetics and a strong pH dependence over the accessible pH range from 3.09 to 5.08 are observed. At pH 3.8, native BP 1 has maxima at 401, 498 and 635 nm, cpd I at 403 nm, and cpd II at 407 and 521 nm with a shoulder at 553 nm. Both cpds I and II appear to be incompletely formed. Isosbestic points between native BP 1 and cpd I occur at 365 and 416 nm, while an isosbestic point in the Soret region between cpd I and cpd II has been observed at 410 nm. Between cpd II and a not yet identified intermediate isosbestic points have been observed at 408, 455 and 526 nm.
The Drosophila ankyrin repeat protein cactus has a predominantly α‐helical secondary structure
Authors: Gay Nicholas J. , Ntwasa Monde
Published: July 2002

The cactus protein is the Drosophila homologue of the mammalian IKB family of cytoplasmic anchor proteins. We have expressed in E. coli and purified a cactus fusion protein, CACT‐Bgl. CACT‐Bgl protein contains the six ankyrin repeat sequences which are necessary for specific binding to the Drosophila rel family transcription factor dorsal. We show that the purified CACT‐Bgl protein can bind specifically to dorsal and, using circular dichroism spectroscopy, that the protein adopts a largely α‐helical secondary structure. A further analysis of the ankyrin repeat domains of cactus, using an improved secondary structure prediction program indicates that the N‐terminal of the repeat will form into a loop structure and the C‐terminal section into an interrupted, amphipathic α‐helix. On the basis of these findings we propose that the ankyrin repeats of cactus fold together into helical bundles interconnected by diverged loops.
Effect of carnitine feeding on the levels of heart and skeletal muscle carnitine of elderly mice
Authors: Costell Mercedes , Grisolia Santiago
Published: July 2002

Aging has been associated with an increase in muscle dysfunction and weakness. We found a decrease in muscle carnitine with age [Biochem. Biophys. Res. Commun., 161 (1989) 1135‐1143], Prolonged oral administration to both young (2‐month‐old) and adult (7‐month‐old) mice with l‐carnitine increased its content in blood by 50%. The levels of carnitine in skeletal and heart muscle of old treated animals became higher than in untreated mice of the same age. However, this extensive restoration did not reach the maximum values present in skeletal muscle of young mice. Our findings indicate that an alteration of the carnitine carrier in the sarcolemma could be responsible for the decrease with age of carnitine in skeletal but not in heart muscle.
Differential expression of a gene encoding an acidic dehydrin in chilling sensitive and freezing tolerant gramineae species
Authors: Danyluk Jean , Houde Mario , Rassart Éric , Sarhan Fathey
Published: July 2002

We have characterized a new wheat cold‐regulated cDNA clone, Wcor410, that accumulates to equivalent levels in root, crown and leaf tissues during cold acclimation. The Wcor410 cDNA contains an ORF encoding a dehydrin‐like glutamate‐rich protein of 28 kDa with a pI of 5.1. However, the acidic nature, the absence of the glycine‐rich repeat and of the conserved N‐terminal region, DEYGNP, suggest that Wcor410 belongs to a different subgroup of the D11 protein family. Northern analysis showed that this gene is expressed only in freezing tolerant gramineae, whereas Southern analysis showed that the Wcor410 gene is present in all monocot species tested. The presence of freezing tolerance‐associated genes in sensitive species such as rice and corn is interesting. Characterization of the regulatory factors controlling these genes may help to establish an appropriate strategy to improve freezing tolerance.
Cloning and expression of human brain type I inositol 1,4,5‐trisphosphate 5‐phosphatase High levels of mRNA in cerebellar Purkinje cells
Authors: De Smedt Florence , Verjans Benoît , Mailleux Pierre , Erneux Christophe
Published: July 2002

In brain and many other tissues, Type I inositol 1,4,5‐trisphosphate (InsP3) 5‐phosphatase is the major isozyme hydrolysing the calcium‐mobilizing second messenger InsP3. We recently reported the cloning and expression of dog thyroid InsP3 5‐phosphatase. During the course of this cloning, screening of a human brain cDNA library allowed us to isolate a cDNA clone D1 with 91% sequence identity with the thyroid sequence. When clone D1 was expressed in Escherichia coli, the fusion protein had InsP3 5‐phosphatase activity. M
r estimates of the recombinant enzyme made by unmunodetection, activity assay after SDS/PAGE or silver staining were consistent with the calculated molecular mass. In situ hybridization on human cerebellum sections localised the mRNA for this enzyme to the Purkinje cells.
Bromelain protease F9 reduces the CD44 mediated adhesion of human peripheral blood lymphocytes to human umbilical vein endothelial cells
Authors: Munzig E. , Eckert K. , Harrach T. , Graf H. , Maurer H.R.
Published: July 2002

The thiol protease bromelain has been shown to remove T‐cell CD44 molecules from lymphocytes and to affect T‐cell activation. We investigated the effect of a highly purified bromelain protease F9 (F9) on the adhesion of peripheral blood lymphocytes (PBL) to human umbilical vein endothelial cells (HUVEC). Preincubation of the lymphocytes with F9 reduced the adherence to about 20% of unstimulated and to about 30% of phorboldibutyrate (P(Bu)2) stimulated lymphocytes. Using flow cytometry, both crude bromelain and protease F9 reduced the expression of CD44, but not of LFA‐1, on PBL. F9 was about 10 times more active than crude bromelain; at 2.5 μg/ml of F9 about 97% inhibition of CD44 expression was found. A mAb against CD44 was tested and found to block the F9‐induced decrease in PBL‐binding to HUVEC. The results indicate that F9 selectively decreases the CD44 mediated binding of PBL to HUVEC.
Changes in activation gating of IsK potassium currents brought about by mutations in the transmembrane sequence
Authors: Wilson Gary G. , Sivaprasadarao Asipu , Findlay John B.C. , Wray Dennis
Published: July 2002

Expression of the rat kidney IsK protein in Xenopus oocytes produces slowly‐activating potassium channel currents. We have investigated the relationship between structure and function of the single putative membrane‐spanning domain using site‐directed mutagenesis. Six mutants were constructed in which consecutive individual amino acids (53 to 58) of the transmembrane region were substituted by cysteine. Expression of four of these mutants in Xenopus oocytes resulted in currents which were similar to wild‐type. However, for one mutant (position 55) activation curves were shifted in a hyperpolarising direction and for another mutant (position 58) activation curve were shifted in a depolarising direction. This suggests that the hydrophobic phenylalanine residues at positions 55 and 58 may play a critical role in IsK activation gating. This spacing of functional amino acids at every third residue may indicate an α‐helical conformation for the membrane‐spanning domain of IsK. Furthermore, these results also indicate that one face of the helix may represent a region of subunit association.
Direct visualization of lipid aggregates in native human bile by light‐ and cryo‐transmission electron‐microscopy
Authors: Kaplun Alon , Talmon Yeshayahu , Konikoff Fred M. , Rubin Moshe , Eitan Arie , Tadmor Maria , Lichtenberg Dov
Published: July 2002

The evolution of microstructures present in human gallbladder and hepatic bile was observed simultaneously by video‐enhanced light microscopy (VELM) and transmission electron microscopy of vitrified specimens (cryo‐TEM), as a function of time after withdrawal from patients. Fresh centrifuged gallbladder bile samples contained small (6 nm) spherical micelles in coexistence with vesicles (40 nm). Out of the seven bile samples investigated four contained, in addition, two types of elongated aggregates that have not been previously described. Uncentrifuged gallbladder bile also contained a mixture of ribbon‐ and plate‐like crystals seen by VELM, but not by cryo‐TEM. In aged (3–6‐week‐old) gallbladder bile samples VELM also revealed spiral and helical crystal structures. No such crystals were present in hepatic bile samples, although microcrystals, not observable by VELM were seen by cryo‐TEM in addition to micelles and vesicles. The similarity of these observations to those observed in bile models lends strong support for the validity of the model systems. Furthermore, the presence of microcrystals in hepatic bile samples, apparently devoid of crystals by light microscopy, indicates that under certain conditions the common criterion of ‘nueleation time’ (NT), based on light microscopy, does not represent the real time of nucleation. In the human bile samples investigated in this study the dissociation between NT and the time of observation of microcrystals was seen in hepatic but not in gallbladder bile samples. Hence, crystal growth may be rate limiting only in dilute biles.
Induction of cell fusion in cultured fibroblasts and epithelial cells by microinjection of EGTA, GTPγS and antifodrin antibodies
Authors: Eskelinen Sinikka , Lehto Veli-Pekka
Published: July 2002

CaCl2, EGTA, GTPγS and anti‐α‐fodrin antibodies were injected into fibroblast‐like IMR‐33 cells and Madin‐Darby bovine kidney (MDBK) epithelial cells cultured both in the presence and absence of cycloheximide and fetal calf serum. EGTA, GTPγS and antifodrin antibody induced fusion of MDBK cells within one hour after injection. The cells formed polykaryons with up to 15 nuclei, reaching an average fusion index of 20%. IMR‐33 cells fused at a slower kinetics and only upon injection of GTPγS or antifodrin antibodies. No fusions were seen in serum‐deprived, quiescent cells. On the other hand, cycloheximide treatment did not prevent the fusions. The results show that cells can be induced to fuse by using agents that interfere with the regulation of the G‐proteins, intracellular calcium level or membrane skeleton. We suggest that the putative fusogens are resident proteins of the plasma membrane which become exposed upon destabilization of the membrane skeleton.
Immunocytochemical localization of Ca2+‐dependent protease from Allomyces arbuscula
Authors: Huber Denise , Ojha Mukti
Published: July 2002

The Ca2+‐dependent protease antisera and the purified specific antibodies from Allomyces arbuscula have shown very specific recognition when blotted against the total protein extract or the purified 43–40 kDa Ca2+‐dependent protease from this aquatic fungus. By immunoblotting and immunofluorescence techniques using specific antibodies, we have shown that the enzyme activity is developmentally regulated and is related to the presence of antigen and not to any specific inhibitor. The immunofluorescence was absent in zoospores but appeared in polarized forms in germinating spores. In elongating hyphae the protease was mainly localized along the cytoplasmic membrane and in the cytoplasm, with predominance at the apex.
In vitro binding of the two‐finger repressor CreA to several consensus and non‐consensus sites at the ipnA upstream region is context dependent
Authors: Espeso Eduardo A. , Peñalva Miguel A.
Published: July 2002

The two zinc‐fingers of the Aspergillus nidulans repressor CreA recognize the consensus hexanucleotide 5'‐SYGGRG‐3'. We have determined all the CreA binding sites in a ∼2 kb region upstream the ipnA gene. Our analysis shows that (i) CreA binds to certain consensus sites in a context‐dependent manner; (ii) five non‐consensus 6‐bp sequences are also recognized by CreA; this non‐canonical binding correlates with the presence of a second, neighbouring CreA binding site, suggesting that recognition of two linked sites stabilizes CreA binding. Our results suggest that the binding possibilities of CreA might be more complex than originally envisaged.
Molecular cloning and expression of human caldecrin
Authors: Tomomura Akito , Akiyama Masashi , Itoh Hirotaka , Yoshino Izumi , Tomomura Mineko , Nishii Yasuho , Noikura Takenori , Saheki Takeyori
Published: July 2002

Earlier we reported the primary structure of serum calcium‐decreasing factor (caldecrin) from rat pancreas, a protein which is considered to be a member of the elastase family. In this report, we describe the isolation of the two homologous cDNA clones encoding caldecrin from human pancreas, the structures of which are identical except for one base and the corresponding amino acid residue. These human caldecrin isoforms are composed of a signal peptide of 16 amino acids, a propeptide of 13 amino acids, and a mature form of 239 amino acids. Both recombinant caldecrins showed the same chymotrypsin‐type protease activity and hypocalcemic activity. The hypocalcemic activity of both remained intact even after treatment with PMSF to abolish their protease activity. These results suggest that human caldecrin possesses hypocalcemic activity that has no connection with its protease activity.
Fetal transverse cerebellar diameter/abdominal circumference ratio in assessing fetal size
Authors: Haller H. , Petrović O. , Rukavina B.
Published: July 2002

Objective: To test the usefulness of the fetal transverse cerebellar diameter/abdominal circumference (TCD/AC) ratio in predicting known small‐for‐gestational‐age (SGA) infants. Method: The relationship between fetal TCD and AC throughout the second half of pregnancy was investigated in 635 well‐dated, normal pregnancies and examined with regard to gestational age and infant birth weight percentiles. Results: One hundred eighteen (19%) fetuses were excluded due to inadequate visualization of the fetal cerebellum. A strong correlation was noted between gestational age determined by the last menstrual period and both fetal TCD (r2 = 0.91338) and AC (r2 = 0.89361) in fetuses with birth weights between the 10th and 90th percentiles (n = 407; mean 14.4, S.D. 1.2). Although the TCD/AC ratio showed a poor correlation with gestational age (r2 = 0.15788), a slight increase was noted during gestation. A TCD/AC ratio greater than 15.5 was present in 80% of SGA infants when measurements were performed within 1 week of delivery. Conclusion: Fetal TCD/AC ratio as a gestational age‐independent method could improve diagnostic sensitivity and specificity in the early detection of fetal growth abnormalities.
The diagnostic value of laparoscopy in 2365 patients with acute and chronic pelvic pain
Authors: Kontoravdis A. , Chryssikopoulos A. , Hassiakos D. , Liapis A. , Zourlas P.A.
Published: July 2002

Objective: To discriminate the etiology in 2365 patients with acute and chronic pelvic pain (APP, CPP). Methods: Diagnostic laparoscopy was carried out in 736 patients (31.1%) with APP and in 1629 (68.9%) with CPP. In 315 patients (13.3%) the diagnostic procedure was extended to operative laparoscopy. Results: The most frequent laparoscopic findings in patients with APP were acute salpingitis and pelvic adhesions (22.8%) and ectopic pregnancy (19%), while in patients with CPP the most frequent findings were pelvic adhesions (35.4%) and endometriosis (24.6%). In 7.5% of patients with APP and 24% with CPP, laparoscopy did not reveal any pathological finding in the pelvis. Among the 315 patients in whom operative laparoscopy was carried out, 40% suffered from APP and 60% from CPP. In the 446 patients (18.9%) without laparoscopic findings no treatment was given, while of the remaining 905 patients 40% were subjected to laparotomy and 60% received conservative treatment. The total incidence of side effects reached 4.7% and serious side effects resulting from emergency laparotomy occurred in 0.15% of patients with pelvic pain. Conclusion: Our results in a large group of patients with pelvic pain show that there are discrepancies in the incidence of laparoscopic findings between patients with APP and CPP. Discrepancies between the two groups of patients were also found during operative laparoscopy, the treatment administered after laparoscopic diagnosis and the complications encountered.
The postpartum period: the key to maternal mortality
Authors: Li X.F. , Fortney J.A. , Kotelchuck M. , Glover L.H.
Published: July 2002

Objectives: To assess postpartum care at an international level, we reviewed published literature on postpartum maternal deaths. Methods: Meta‐analysis was used to summarize the literature reviewed. Postpartum deaths in developing countries were compared with those in the United States. Results: In both developing countries and the United States, >60% of maternal deaths occurred in the postpartum period; 45% of postpartum deaths occurred within 1 day of delivery, >65% within 1 week, >80% within 2 weeks. In developing countries, 80% of postpartum deaths caused by obstetric factors occurred within 1 week. Conclusions: The first 24 h postpartum and the first postpartum week is the high risk of postpartum deaths, and the risk remains significant until the second week after delivery. In developing countries, hemorrhage, pregnancy‐induced hypertension complications, and obstetric infection are commonest causes of postpartum deaths. We suggest primary prevention, early detection, and secondary prevention of postpartum deaths.
Translational selection shapes codon usage in the GC‐rich genome of Chlamydomonas reinhardtii
Authors: Naya Hugo , Romero Héctor , Carels Nicola , Zavala Alejandro , Musto Héctor
Published: July 2002

In unicellular species codon usage is determined by mutational biases and natural selection. Among prokaryotes, the influence of these factors is different if the genome is skewed towards AT or GC, since in AT‐rich organisms translational selection is absent. On the other hand, in AT‐rich unicellular eukaryotes the two factors are present. In order to understand if GC‐rich genomes display a similar behavior, the case of Chlamydomonas reinhardtii was studied. Since we found that translational selection strongly influences codon usage in this species, we conclude that there is not a common pattern among unicellular organisms.