bluuebunny/crossref_metadata_2025 huggingface dataset:
Down‐regulation of LH/hCG receptor in rat cultured granulosa cells
Authors: Kishi Hiroshi , Minegishi Takashi , Tano Mari , Abe Yumiko , Ibuki Yoshito , Miyamoto Kaoru
Published: July 2002

Initial experiments established the experimental conditions necessary for the induction of LH receptor mRNA down‐regulation in granulosa cells isolated from diethylstilbestrol (DES)‐primed immature rats. LH/hCG receptor mRNA was first induced in granulosa cells by incubating them for 24 h with FSH. Exposure of granulosa cells to a second dose of gonadotropin caused a decrease in LH/hCG receptor mRNA and binding levels after 4 h. This effect was transient, by 12 h the mRNA levels had returned to control levels, and by 24 h the mRNA levels were higher than the control. To evaluate the ability of cAMP to down‐regulate the receptor, cells were exposed to 8‐Br‐cAMP. The pattern of sustained decrease in LH/hCG receptor mRNA levels seen with 8‐Br‐cAMP was similar to that with gonadotropins. The presence of activin with FSH or hCG is more effective than FSH or hCG alone in inducing LH/hCG receptor down‐regulation in rat granulosa cells. The LH/hCG receptor mRNA levels decreased in a dose‐dependent manner in the presence of increasing concentrations (30–100 ng/ml) of activin with FSH. These observations indicate that an increase in cAMP causes down‐regulation of LH/hCG receptor mRNA and contributes to the effect of FSH and hCG, whereas basal cAMP activity is required for LH/hCG receptor mRNA expression.
Reciprocal protection of LDL and HDL oxidised by ⋅OH free radicals in the presence of oxygen
Authors: Bonnefont-Rousselot Dominique , Khalil Abdelouahed , Gardès-Albert Monique , Delattre Jacques
Published: July 2002

© 1997 Federation of European Biochemical Societies.
Plant cell pH‐static circuit mediated by fusicoccin‐binding proteins
Authors: Drabkin Artem V , Trofimova Marina S , Smolenskaya Irina N , Klychnikov Oleg I , Chelysheva Vera V , Babakov Alexey V
Published: July 2002

On sugar beet protoplasts that carry two types of fusicoccin‐binding sites, a pH downshift in a physiological range (7.0–6.6) markedly enhanced the efficiency of fusicoccin (FC) binding, mainly owing to increased avidity of low‐affinity FC‐binding sites. This may allow the FC‐binding proteins to act as pH‐sensitive modulators of cell activity, for instance, via plasma membrane H+‐ATPase or potassium channels. © 1997 Federation of European Biochemical Societies
Lack of gradual regulation of tetracycline‐controlled gene expression by the tetracyclin‐repressor/VP16 transactivator (tTA) in cultured cells
Authors: Hop Caroline , de Waard Vivian , van Mourik Jan A. , Pannekoek Hans
Published: July 2002

© 1997 Federation of European Biochemical Societies.
Do specific linoleate 13‐lipoxygenases initiate β‐oxidation?1
Authors: Feussner Ivo , Kühn Hartmut , Wasternack Claus
Published: July 2002

The germination process of oilseed plants is characterized by a mobilization of the storage lipids which constitute the major carbon source for the growing seedling. Despite the physiological importance of the lipid mobilization, the mechanism of this process is not well understood. Recently, it was found that a specific linoleate 13‐lipoxygenase is induced during the stage of lipid mobilization in various oilseed plants and that this enzyme is translocated to the membranes of the lipid storage organelles, the so called lipid bodies. Lipoxygenase expression was paralleled by the occurrence of enantiospecific hydro(pero)xy polyenoic fatty acid derivatives in the storage lipids suggesting the in vivo action of the enzyme. Furthermore, it was reported that oxygenated polyenoic fatty acids, in particular as 13(S)‐hydro(pero)xy‐9(Z),11(E)‐octadecanoic acid [13(S)‐H(P)ODE], are cleaved preferentially from the storage lipids when compared with their non‐oxygenated linoleate residues. These findings may suggest that 13(S)‐H(P)ODE may constitute the endogenous substrate for β‐oxidation during lipid mobilization of oilseed plants.
Sequential assignment and secondary structure determination for the Src homology 2 domain of hematopoietic cellular kinase
Authors: Zhang Weixing , Smithgall Thomas E. , Gmeiner William H.
Published: July 2002

The hematopoietic cellular kinase (Hck) is a member of the Src family of non‐receptor protein–tyrosine kinases and participates in signal transduction events regulating the growth, differentiation and function of phagocytes. The secondary structure of the SH2 domain for Hck was determined for a 13C/15N‐enriched sample using multi‐dimensional NMR spectroscopy. The secondary structure for the domain was determined from chemical shift indices [1Hα, 13Cα and 13C′], sequential NOEs [d
αN(i, i+1) and d
NN(i, i+1)], and 3
J
αN scalar coupling constants. The Hck SH2 domain consists of two α‐helices and seven β‐strands. Complementary strands of β‐sheets were identified from long‐range NOEs using a novel 3D, 13C/15N‐edited HMQC‐NOESY‐(HCACO)NH experiment that correlated 1Hα resonances between β‐strands. The secondary structure for Hck SH2 is similar to that predicted from the sequence alignment of the Src‐family protein tyrosine kinases.
Unusual structural stability and ligand induced alterations in oligomerization of a galectin
Authors: Surolia Avadhesha , Swaminathan Chittoor P , Ramkumar Radha , Podder Sunil K
Published: July 2002

Abstract L‐14, a 14‐kDa S‐type lectin shows the jelly roll tertiary structural fold akin to legume lectins yet, unlike them, it does not dissociate on thermal unfolding. In the absence of ligand L‐14 displays denaturation transitions corresponding to tetrameric and octameric entities. The presence of complementary ligand reduces the association of L‐14, which is in stark contrast with legume lectins where no alterations in quaternary structures are brought about by saccharides. From the magnitude of the increase in denaturation temperature induced by disaccharides the binding constants calculated from differential scanning calorimetry are comparable with those extrapolated from titration calorimetry indicating that L‐14 interacts with ligands essentially in the folded state.
Mannosylphosphate transfer to cell wall mannan is regulated by the transcriptional level of the MNN4 gene in Saccharomyces cerevisiae
Authors: Odani Tetsuji , Shimma Yoh-ichi , Wang Xiao-Hui , Jigami Yoshifumi
Published: July 2002

Mannosylphosphorylation is a major oligosaccharide modification that provides negative charge in the Saccharomyces cerevisiae cell wall. Although two genes, MNN6 and MNN4, which encode a mannosylphosphate transferase and its putative positive regulator, respectively, are involved in this modification, the amount of Mnn4p has been found to be a limiting factor for mannosylphosphorylation. The level of mannosylphosphorylation increased at late‐logarithmic and stationary phases of cell growth, and this was correlated to the transcriptional enhancement of MNN4. We also find that mannosylphosphate transfer to mannan is negatively regulated by the protein kinase A pathway, while the presence of 0.5 M potassium chloride enhanced MNN4 transcription. This type of transcriptional regulation is observed in many stress response genes, implying that mannosylphosphate transfer is involved in the cellular response to a variety of stresses.
Non‐Watson‐Crick base pairs modulate homologous alignments in RecA pairing reactions
Authors: Karthikeyan G , Wagle Mahendra D , Rao Basuthkar J
Published: July 2002

Complementary pairing by RecA was examined in vitro to investigate how homology is deciphered from non‐homology. Somewhere in a window of 40–50% sequence complementarity, RecA pairing begins to manifest the specificity of homology. Quantitation reveals a hierarchy among non‐Watson‐Crick mispairs: RecA reaction treats six out of 12 possible mispairs as good ones and three each of the remaining ones as moderate and bad pairs. The mispairs seem to function as independent pairing units free of sequence context effects. The overall strength of pairing is simply the sum of the constituent units. RecA mediated gradation of mispairs, free of sequence context effects, might offer a general thumb‐rule for predicting the pairing strength of any alignment that carries multiple mispairs.
Substitution of 5‐methylcytosines for cytosines enhances the stability of topoisomerase I‐DNA complexes and modulates the sequence selectivity of camptothecin‐induced DNA cleavage
Authors: Carrasco Carolina , Waring Michael J , Bailly Christian
Published: July 2002

We have investigated the binding and cleavage of DNA by human topoisomerase I using a 160 bp restriction fragment containing either natural bases or 5‐methylcytosine residues in place of cytosines. Experiments were performed in the presence and absence of the antitumour drug camptothecin which specifically inhibits topoisomerase I. Replacement of all cytosines with 5‐methylcytosine residues (i) reinforces the enzyme‐DNA interaction, (ii) enhances the stability of topoisomerase I‐DNA complexes and (iii) modulates the sequence selectivity of camptothecin‐induced DNA cleavage. The methyl group exposed in the major groove of the double helix is identified as a critical element for the interaction between topoisomerase I and DNA.
Projection map of the reaction center‐light harvesting 1 complex from Rhodopseudomonas viridis at 10 Å resolution
Authors: Ikeda-Yamasaki Ikuko , Odahara Takayuki , Mitsuoka Kaoru , Fujiyoshi Yoshinori , Murata Kazuyoshi
Published: July 2002

The photosynthetic reaction center‐light harvesting 1 complex from Rhodopseudomonas viridis was purified and reconstituted into two‐dimensional crystals. The single‐layered crystalline sheets with lattice parameters a=b=133.3 Å and γ=120° were investigated by electron cryo‐microscopy and the projection map at 10 Å resolution was calculated. The opening diameter of the light‐harvesting ring of 72 Å is sufficient to allow slight movement of the reaction center within the ring. Based on characteristic features observed in the projection map, the mechanism of energy transfer from the light‐harvesting 1 complex to the reaction center was discussed.
Human natural resistance‐associated macrophage protein is a new type of microtubule‐associated protein
Authors: Tokuraku Kiyotaka , Nakagawa Hiroyuki , Kishi Fumio , Kotani Susumu
Published: July 2002

Natural resistance‐associated macrophage protein 1 (NRAMP1) is a putative membrane protein that dominates natural resistance to infection. An NRAMP1‐glutathione S‐transferase fusion protein was used to test the ability of the NRAMP1 NH2‐terminal domain to bind to taxol‐stabilized microtubules. Co‐sedimentation analysis showed that the fusion protein binds to microtubules. Although the NH2‐terminal domain of the NRAMP1 molecule has structural homology with the Pro‐rich region of microtubule‐associated protein 4 (MAP4), the presence of the MAP4 microtubule‐binding domain fragment had little effect on the binding of the fusion protein to microtubules.
Electrogenicity accompanies photoreduction of the iron‐sulfur clusters FA and FB in photosystem I
Authors: Mamedov Mahir D , Gourovskaya Kira N , Vassiliev Ilya R , Golbeck John H , Sememov Alexey Yu
Published: July 2002

Photovoltage responses accompanying electron transfer on the acceptor side of photosystem I (PS I) were investigated in proteoliposomes containing PS I complexes from the cyanobacterium Synechococcus sp. PCC 6301 using a direct electrometrical technique. The relative contributions of the FX→FB and the FX→FA electron transfer reactions to the overall electrogenicity were elucidated by comparing the sodium dithionite‐induced decrease in the magnitude of the total photoelectric responses in control and in FB‐less (HgCl2‐treated) PS I complexes. The results obtained suggest that the electrogenesis on the acceptor side of PS I is related to electron transfers between both FX and FA and FA and FB. Based on the electrogenic nature of the latter reaction in PS I complexes, we conclude that FA rather than FB is the acceptor proximal to FX.
Secretion of D‐aspartic acid by the rat testis and its role in endocrinology of the testis and spermatogenesis
Authors: D'Aniello Antimo , Di Fiore Maria Maddalena , D'Aniello Gemma , Colin Frantz E. , Lewis Giavonni , Setchell Brian P.
Published: July 2002

The D‐isomer of aspartic acid (D‐Asp) has been found in rat testes. In the present study, samples of testicular venous blood plasma, rete testis fluid, interstitial extracellular fluid, luminal fluid from the seminiferous tubules, testicular parenchymal cells, epididymal spermatozoa and peripheral blood plasma were collected and analyzed for D‐Asp by two methods, an enzymatic and a chromatographic HPLC method. The two methods gave very similar results for all samples. The highest concentrations of D‐Asp (about 120 nmol/ml) were found in testicular venous blood plasma, with slightly lower concentrations in rete testis fluid (95 nmol/ml) and epididymal spermatozoa (80 nmol/g wet weight). Lower levels were found in testicular parenchymal cells (which would comprise mostly spermatids and spermatocytes), luminal fluid from the seminiferous tubules and interstitial extracellular fluid (26, 23 and 11 nmol/ml respectively). However, these values were all higher than those for peripheral blood plasma (6 nmol/ml). It would appear that D‐Asp is being secreted by the testis mostly into the venous blood, passing thence into the rete testis fluid and being incorporated into the spermatozoa at the time or after they leave the testis. The distribution of D‐Asp is thus quite different from that of testosterone, and its role and the reason for its high concentration in the male reproductive tract remain to be elucidated.
A recombinant ribosome‐inactivating protein from the plant Phytolacca dioica L. produced from a synthetic gene1
Authors: Del Vecchio Blanco Francesca , Cafaro Valeria , Di Maro Antimo , Scognamiglio Roberta , Siniscalco Gesualdo , Parente Augusto , Di Donato Alberto
Published: July 2002

Phytolacca dioica L. leaves produce at least two type‐I ribosome‐inactivating proteins. Each polypeptide chain is subjected to different post‐translational modifications giving rise to PD‐L1 and PD‐L2, and PD‐L3 and PD‐L4, each polypeptide pair having the same primary structure. With the aim of exploiting the cytotoxic properties of these proteins as potential biological phytodrugs, a gene encoding PD‐L4 was designed based on criteria expected to maximize the translation efficiency in tomato. The gene was constructed from 18 oligonucleotides and preliminarily expressed in Escherichia coli, using the T7 promoter system. The protein produced was insoluble and accumulated in inclusion bodies to about 300 mg/l of culture. Ribosome‐inactivating activity was generated by controlled oxidation of the reduced and denatured protein. The recombinant protein was indistinguishable from natural PD‐L4 as isolated from leaves of Phytolacca dioica, in both catalytic activity and primary structure.
Pyrimidinoceptor potentiation by ATP in NG108‐15 cells
Authors: Sak Katrin , Kelve Merike , Uri Asko , Järv Jaak
Published: July 2002

Regulation of inositol phospholipid hydrolysis by UTP and UDP in neuroblastoma×glioma hybrid cell line NG108‐15 was potentiated in the presence of ATP. The effect of ATP was dose dependent and shifted the EC50 value for these uracil nucleotides up to three powers of magnitude, having no influence on the maximal value of the response. Adenine nucleotides (ADP, AMP, adenosine 5′‐O‐(3‐thiotriphosphate) (ATPγS), β,γ‐methyleneadenosine 5′‐triphosphate (βγMeATP), 3′‐O‐(4‐benzoyl)benzoyl ATP (BzATP) and 3′‐deoxyadenosine 5′‐O‐(1‐thio)triphosphate (dATPαS)) as well as adenosine, had no influence on the pyrimidinoceptor response. The potentiation effect was abolished by excess of EDTA. The results were in agreement with the hypothesis of pyrimidinoceptor affinity regulation via extracellular phosphorylation of the receptor protein, initiated by ATP. This mechanism may have physiological implication for functioning of uracil nucleotides as endogenous signaling molecules.
Analysis of the conserved acidic residues in the regulatory domain of PhoB
Authors: Zundel Cara J. , Capener Dale C. , McCleary William R.
Published: July 2002

The PhoB protein from Escherichia coli is a member of the two‐component signal transduction pathway that controls an adaptive response to limiting phosphate. Activation involves its phosphorylation on a conserved aspartate. Site‐directed mutations were introduced at conserved acidic residues. The E9D, D10E, D10N, E11A, E11D and E11Q mutants were each able to induce alkaline phosphatase under low phosphate growth conditions whereas the E9A, D10A, D53A, D53E and D53N could not. The E9Q mutant was constitutively active. Phosphorylation assays showed that only the E9D, E11A, E11Q and E11D mutants were phosphorylated by acetyl phosphate. Most mutants also displayed defects in magnesium binding.
The aminoacceptor stem of the yeast tRNALys contains determinants of mitochondrial import selectivity
Authors: Kazakova H.A , Entelis N.S , Martin R.P , Tarassov I.A
Published: July 2002

Yeast tRNALys
CUU is nucleus‐encoded and is partially imported into the mitochondria. Another lysine isoacceptor, tRNALys
SUU, is also nucleus‐encoded but is not imported. These two tRNAs differ in 21 bases. We have previously localised import selectivity determinants in the anticodon arm. By in vitro import of mutant transcripts and by expression of mutant tRNA genes in vivo we show here that the first base pair (1:72) and the discriminator base 73 are also relevant to import selectivity. Replacement of bases 1:72 in tRNALys
SUU by those of tRNALys
CUU makes it importable with a transport efficiency similar to natural.
Basic homopolyamino acids, histones and protamines are potent antagonists of angiogenin binding to ribonuclease inhibitor
Authors: Moenner Michel , Chauvière Muriel , Chevaillier Philippe , Badet Josette
Published: July 2002

A radio‐ribonuclease inhibitor assay based on the interaction of 125I‐angiogenin with ribonuclease inhibitor (RI) was used to detect pancreatic‐type ribonucleases and potential modulators of their action. We show that highly basic proteins including the homopolypeptides poly‐arginine, poly‐lysine and poly‐ornithine, core histones, spermatid‐specific S1 protein and the protamines HP3 and Z3 were strong inhibitors of angiogenin binding to RI. A minimum size of poly‐arginine and poly‐lysine was required for efficient inhibition. The inhibition likely resulted from direct association of the basic proteins with the acidic inhibitor, as RI bound to poly‐lysine and protamines while 125I‐angiogenin did not. Antagonists of the angiogenin‐RI interaction are potential regulators of either angiogenin‐triggered angiogenesis and/or intracellular RI function, depending on their preferential target.
Nitric oxide inhibits cardiac energy production via inhibition of mitochondrial creatine kinase
Authors: Kaasik Allen , Minajeva Ave , De Sousa Elvira , Ventura-Clapier Renée , Veksler Vladimir
Published: July 2002

Nitric oxide biosynthesis in cardiac muscle leads to a decreased oxygen consumption and lower ATP synthesis. It is suggested that this effect of nitric oxide is mainly due to the inhibition of the mitochondrial respiratory chain enzyme, cytochrome c oxidase. However, this work demonstrates that nitric oxide is able to inhibit soluble mitochondrial creatine kinase (CK), mitochondrial CK bound in purified mitochondria, CK in situ in skinned fibres as well as the functional activity of mitochondrial CK in situ in skinned fibres. Since mitochondrial isoenzyme is functionally coupled to oxidative phosphorylation, its inhibition also leads to decreased sensitivity of mitochondrial respiration to ADP and thus decreases ATP synthesis and oxygen consumption under physiological ADP concentrations.
Single channel analysis of recombinant major outer membrane protein porins from Chlamydia psittaci and Chlamydia pneumoniae
Authors: Wyllie S. , Longbottom D. , Herring A.J. , Ashley R.H.
Published: July 2002

We recently demonstrated that the major outer membrane protein of Chlamydia psittaci, the primary vaccine candidate for combating chlamydial infections, functions as a porin‐like ion channel. In this study, we have cloned, expressed and functionally reconstituted recombinant major outer membrane proteins from C. psittaci and Chlamydia pneumoniae and analysed them at the single channel level. Both form porin‐like ion channels that are functionally similar to those formed by native C. psittaci major outer membrane protein. Also, like the native channels, recombinant C. psittaci channels are modified by a native major outer membrane protein‐specific monoclonal antibody. This is the first time that native function has been demonstrated for recombinant chlamydial major outer membrane proteins. Future bilayer reconstitution will provide a strategy for detailed structure/function studies of this new subclass of bacterial porins and the work also has important implications for successful protein refolding and the development of improved subunit vaccines.
The titrations of Asp‐85 and of the cation binding residues in bacteriorhodopsin are not coupled
Authors: Eliash T , Ottolenghi M , Sheves M
Published: July 2002

An outstanding problem relating to the structure and function of bacteriorhodopsin (bR), which is the only protein in the purple membrane of the photosynthetic microorganism Halobacterium salinarium, is the relation between the titration of Asp‐85 and the binding/unbinding of metal cations. An extensively accepted working hypothesis has been that the two titrations are coupled, namely, protonation of Asp‐85 (located in the vicinity of the retinal chromophore) and cation unbinding occur concurrently. We have carried out a series of experiments in which the purple⇔blue equilibrium and the binding of Mn2+ ions (monitored by electron spin resonance) were followed as a function of pH for several (1–4) R=[Mn2+]/[bR] molar ratios. Data were obtained for native bR, bR mutants, artificial bR and chemically modified bR. We find that in the native pigment the two titrations are separated by more than a pK
a unit [ΔpK
a=pK
a(P/B)−pK
a(Mn2+)=(4.2−2.8)=1.4]. In the non‐native systems, ΔpK
a values as high as 5 units, as well as negative ΔpK
as, are observed. We conclude that the pH titration of cation binding residues in bR is not directly related to the titration of Asp‐85. This conclusion is relevant to the nature of the high affinity cation sites in bR and to their role in the photosynthetic function of the pigment.
Interaction of the p70 subunit of RPA with a DNA template directs p32 to the 3′‐end of nascent DNA
Authors: Kolpashchikov D.M. , Weisshart K. , Nasheuer H.-P. , Khodyreva S.N. , Fanning E. , Favre A. , Lavrik O.I.
Published: July 2002

Human replication protein A is a heterotrimeric protein involved in various processes of DNA metabolism. To understand the contribution of replication protein A individual subunits to DNA binding, we have expressed them separately as soluble maltose binding protein fusion proteins. Using a DNA construct that had a photoreactive group incorporated at the 3′‐end of the primer strand, we show that the p70 subunit on its own is efficiently cross‐linked to the primer at physiological concentrations. In contrast, crosslinking of the p32 subunit required two orders of magnitude higher protein concentrations. In no case was the p14 subunit labelled above background. p70 seems to be the predominant subunit to bind single‐stranded DNA and this interaction positions the p32 subunit to the 3′‐end of the primer.
Cell‐free synthesis of the Ras‐binding domain of c‐Raf‐1: binding studies to fluorescently labelled H‐Ras
Authors: Sydor Jens R , Seidel Ralf P , Goody Roger S , Engelhard Martin
Published: July 2002

It has previously been shown that the transient kinetics of the interaction between the Ras‐binding domain of c‐Raf‐1 and the proto‐oncoprotein Ras can be followed by stopped‐flow measurements using the 2′,3′‐(N‐methylanthraniloyl) fluorescence of 2′,3′‐(N‐methylanthraniloyl) guanyl‐5′‐yl‐imidodiphosphate‐labelled Ras. In continuation of this work, we demonstrate that the His‐tagged Ras‐binding domain of c‐Raf‐1 can also be synthesized in a cell‐free expression system. After purification by Ni2+ affinity chromatography, His‐tagged Ras‐binding domain of c‐Raf‐1 could be isolated in sufficient amounts for biochemical and biophysical investigations. The results obtained describe the first example of a cell‐free synthesized protein which has been used for stopped‐flow measurements to determine the transient kinetics of protein‐protein interactions with an effector.
Essential arginine residues in maize starch synthase IIa are involved in both ADP‐glucose and primer binding
Authors: Imparl-Radosevich Jennifer M , Keeling Peter L , Guan Hanping
Published: July 2002

The arginine‐specific reagent phenylglyoxal inactivated the activity of maize starch synthase IIa (SSIIa), due to the modification of at least one arginine residue out of a possible 42. The addition of ADPGlc completely protected SSIIa from the inactivation, indicating that arginine may be involved in the interaction of this anionic substrate with SSIIa. However, site‐directed mutagenesis of the conserved Arg‐214 in SSIIa showed that this amino acid is important for apparent affinity of SSIIa for its primer (amylopectin and glycogen), as evidenced by a marked increase in theKmfor primer upon substitution of this amino acid with no concomitant change inVmax,Kmfor ADPGlc, or secondary structure. Therefore, Arg‐214 of SSIIa appears to play a role in its primer binding.
Mutations in the yeast two pore K+ channel YKC1 identify functional differences between the pore domains
Authors: Vergani Paola , Blatt Michael R.
Published: July 2002

The K+ channel of Saccharomyces cerevisiae encoded by the YKC1 gene includes two pore‐loop sequences that are thought to form the hydrophilic lining of the pore. Gating of the channel is promoted by membrane depolarisation and is regulated by the extracellular K+ concentration ([K+]o) both in the yeast and when expressed in Xenopus oocytes. Our previous work showed that substitutions of equivalent residues L293 and A428 within the pore‐loops had qualitatively similar effects on both the [K+]o‐sensitivity of channel gating and its voltage‐dependence. Here, we report that mutations of equivalent residues N275 and N410, N‐terminal from the K+ channel signature sequences of the two pores, have very different actions on channel gating and, in this case, are without effect on its voltage‐sensitivity. The mutation N410D slowed current activation in a [K+]o‐dependent manner and it accelerated deactivation, but without significant effect on the apparent affinity for K+. The N275D mutant, by contrast, had little effect on the [K+]o‐sensitivity for activation and it greatly altered the [K+]o‐dependence of current deactivation. Neither mutant affected the voltage‐dependence of the steady‐state current nor the ability for other alkali cations to substitute for K+ in regulating gating. The double mutant N410D‐N275D showed characteristics of N410D in the [K+]o‐sensitivity of current activation and of N275D in the [K+]o‐sensitivity of deactivation, suggesting that little interaction occurs between pore domains with mutations at these sites. The results indicate that the two pore domains are not functionally equivalent and they suggest that the regulation of gating by external K+ is mediated by K+ binding at two physically distinct sites with different actions.
B‐myb proto‐oncogene products interact in vivo with each other via the carboxy‐terminal conserved region
Authors: Kim Taenam , Jung Haiyoung , Min Sanghyun , Kim Kyong-Tai , Ha Hyunjung
Published: July 2002

Using the yeast two‐hybrid assay and in vivo binding assay, we investigated whether B‐myb oncogene products (B‐myb) can associate with each other. Specificity tests of the yeast two‐hybrid system showed a self‐association of B‐myb proteins in yeast. Cotransfection experiments demonstrated that B‐myb proteins form a complex in vivo. Deletion analysis revealed that this binding was sufficiently mediated by the carboxy‐terminal conserved region of B‐myb. In addition, the B‐myb self‐association is directly dependent on the amount of expressed B‐myb in cells and slightly increased by the dephosphorylation state. These results suggested that B‐myb could form a complex and influence its transcriptional activity.
A single‐stranded loop in the 5′ untranslated region of cucumber mosaic virus RNA 4 contributes to competitive translational activity
Authors: Kwon Chang Seob , Chung Won-Il
Published: July 2002

The 5′ untranslated region (UTR) of cucumber mosaic virus (CMV) RNA 4 confers a highly competitive translational advantage on a heterologous luciferase open reading frame. Here we investigated whether secondary structure in the 5′ UTR contributes to this translational advantage. Stabilization of the 5′ UTR RNA secondary structure inhibited competitive translational activity. Alteration of a potential single‐stranded loop to a stem by substitution mutations greatly inhibited the competitive translational activity. Tobacco plants infected with wild type virus showed a 2.5‐fold higher accumulation of maximal coat protein than did plants infected with a loop‐mutant virus. Amplification of viral RNA in these plants could not explain the difference in accumulation of coat protein. Phylogenetic comparison showed that potential single‐stranded loops of 12–23 nucleotides in length exist widely in subgroups of CMV.
Identification of the two histidine residues responsible for the inhibition by malonyl‐CoA in peroxisomal carnitine octanoyltransferase from rat liver
Authors: Morillas Montserrat , Clotet Josep , Rubı́ Blanca , Serra Dolors , Asins Guillermina , Ariño Joaquı́n , Hegardt Fausto G.
Published: July 2002

Carnitine octanoyltransferase (COT), an enzyme that facilitates the transport of medium chain fatty acids through peroxisomal membranes, is inhibited by malonyl‐CoA. cDNAs encoding full‐length wild‐type COT and one double mutant variant from rat peroxisomal COT were expressed in Saccharomyces cerevisiae. Both expressed forms were expressed similarly in quantitative terms and exhibited full enzyme activity. The wild‐type‐expressed COT was inhibited by malonyl‐CoA like the liver enzyme. The activity of the enzyme encoded by the double mutant H131A/H340A was completely insensitive to malonyl‐CoA in the range assayed (2–200 μM). These results indicate that the two histidine residues, H131 and H340, are the sites responsible for inhibition by malonyl‐CoA. Another mutant variant, H327A, abolishes the enzyme activity, from which it is concluded that it plays an important role in catalysis.
Neonatal outcome following maternal opiate use in late pregnancy
Authors: Sinha C. , Ohadike P. , Carrick P. , Pairaudeau P. , Armstrong D. , Lindow S.W.
Published: July 2002

Objective: To determine the neonatal outcome in the form of use of morphine and triclofos to treat the neonatal abstinence syndrome following maternal opiate use in late pregnancy. Methods: Retrospective case study of 51 pregnancies associated with maternal opiate use between January 1992 and December 1997. Results: There were 51 pregnancies which resulted in 51 live births. In the third trimester 22 women took methadone only, 19 women used heroin and 10 women stopped opiate use during pregnancy. Babies of methadone using mothers were less likely to be treated with morphine or triclofos than heroin using women. Morphine, triclofos use was more common in high dose methadone users compared with low users. Conclusions: Successful methadone substitution compared with continued heroin use results in reduced morphine and triclofos use in the babies exposed.
Reversible contraception: issues faced by emerging countries
Authors: Garza‐Flores J
Published: July 2002

There is no doubt that fertility regulation represents an important contribution to reproductive health. The role of fertility regulation in decreasing maternal mortality has been well documented. Thus, the use of contraceptives in developing countries has been projected to increase from 51% (1990) to 59% in the year 2000. Accordingly, 151 million surgical procedures for female and male sterilization, 8.7 billion cycles of oral contraceptives (OCs), 663 million doses of injectables, 310 million intrauterine devices (IUDs), and 44 billion condoms will be required in developing countries during the 1990s. Contraceptives are currently being manufactured in at least 27 developing countries. Subsidiaries of multinational companies are often involved in the local production of OCs and condoms, whereas most domestic IUD manufacturing ventures have been undertaken by local private companies. External assistance agencies have been active in supporting the local production of contraceptives.
IAMANEH and the new concept of reproductive health
Authors: Pinotti J.A , Drezzet J
Published: July 2002

Prof. Hubbert De Watteville, first Secretary General and founder of the International Federation of Gynecologists and Obstetricians (FIGO), created the International Association for Maternal and Neonatal Health (IAMANEH) in 1977, after realizing that the improvements in maternal and neonatal health observed in developed countries were not benefiting the so‐called Third World. The purpose of IAMANEH was to stimulate local associations to take initiatives to improve the health of the women and their children. Lack of attention to women's own health has been characteristic of the emphasis on antenatal care to protect the newborn or family planning to reduce demographic growth, with little attention to the needs of women themselves. The evolution to the more comprehensive concepts of reproductive health has been slow and moved by a few visionaries in the Obstetrics and Gynecology establishment and by the women's rights movement. Currently, the concept has been accepted at world conferences, such as those of Cairo (1994) and Beijing (1995). Brazil officially incorporated an even wider concept of Comprehensive Women's Health Care, originated at the State University of Campinas and formally adopted by the Federal Government in 1984. It was placed in practice in the state of São Paulo between 1987 and 1990, showing important improvements in the quantity and quality of services provided to women.
The promise of public/private sector collaboration in the development of new contraceptives: the experience of CICCR
Authors: Harper M.J.K.
Published: July 2002

The Consortium for Industrial Collaboration in Contraceptive Research (CICCR) was established in 1995 with funding from two philanthropic foundations. Now just over 3 years later, it is supported by five foundations and a United Nations agency. Work in three priority areas of male methods, vaginal methods and monthly methods for women is progressing well. Collaboration with 10 industrial entities has been established, and more than 60 contracts with investigators at not‐for‐profit institutions have been funded. It can be concluded that CICCR has provided an efficient and effective mechanism for promoting industrial collaboration in contraceptive R&D, and fills a need not covered by other agencies active in the field.
Dissecting glioma invasion: interrelation of adhesion, migration and intercellular contacts determine the invasive phenotype
Authors: Kaczmarek Elzbieta , Zapf Svenja , Bouterfa Hakim , Tonn Jörg C. , Westphal Manfred , Giese Alf
Published: July 2002

The invasive cellular behavior of malignant gliomas is determined by receptor mediated cell–substratum contacts and cell–cell interaction as well as cellular locomotion. This study attempts to break down the complex phenomena of the invasive process into their components of attachment to neighboring cells, aggregate formation, adhesion to matrix substratum, migration and invasion into three‐dimensional cellular aggregates separately analyzed in different in vitro assay systems. Using a panel of 13 glioma cell lines, adhesion to non‐specifically or merosin coated surfaces was correlated to monolayer cell migration and dissemination of tumor cells from aggregates plated on these substrates. The formation kinetics of aggregates were determined and compared to the ability of these cells to rapidly attach and form mechanically stable cell–cell contacts. The motility rates in the different assay systems as well as cell–cell attachment was correlated to invasion of re‐aggregated tumor cells into fetal rat brain.

A tight positive correlation was found for substrate adhesion and monolayer migration. In contrast, cell–substratum contacts had little influence on dissemination of cells out of three‐dimensional aggregates and no association between monolayer migration and migration of cells out of aggregates was detected. The ability of glioma cells to rapidly form aggregates was associated with enhanced migration out of aggregates. The capacity to invade fetal rat brain aggregates was correlated with the capacity to form stable intercellular adhesion as measured in a cell–cell adhesion assay. Invasion in this system was not found to be associated with migration in monolayer or with migration out of tumor aggregates. This study highlights that current in vitro assays for invasion only represent isolated aspects of the multi‐cascade process which is involved in tumor cell invasion.
Are washout periods useful in antidepressant trials?
Authors: Even C. , Friedman S. , Dardennes R.
Published: July 2002

Single-blind placebo washout periods before randomisation enable the elimination of the psychotropic agents previously received. They subdue carryover effects which could be achieved without using a placebo. Washout periods also purport to identify and eliminate the placebo responders. Trivedi et al. performed a meta-analysis which included 101 studies. They demonstrated that placebo washout periods do not reduce the response rate in the placebo group and do not increase the difference between the placebo and the treated group. This held true for all the different antidepressant classes. In another study, Greenberg et al. analysed 28 antidepressant controlled trials published between 1983 and 1992 and found no difference between trials with or without a placebo washout period in terms of response rate in either the placebo or the treated group. Therefore, placebo washout periods, although appealing and widely used, may not reduce the number of patients who respond to placebo. Besides, the patients who respond during the washout period have very diverse outcomes after three months. This subgroup is likely to be heterogeneous and should be better studied. Some authors have stated that washout periods may bring in confounding effects such as lowering the observed difference between the treated and placebo group. Their explanation was that response to placebo is not a stable characteristic and that responding to placebo during the washout period may subsequently lower the level of placebo-induced improvement. It would also be cumbersome if washout periods covered the problems related to the placebo and blindness issues, which are often neglected. Finally, it appears necessary to further assess the usefulness of single-blind washout periods.
Social integration and the quality of life of schizophrenic patients in different types of complementary care
Authors: Leiße M , Kallert T.W
Published: July 2002

Following reunification in Germany in 1990 the new states in the Federal Republic faced the task of restructuring and rebuilding the structures of complementary care for the chronically mentally ill. First and foremost, residential facilities had to be established that would correspond to and meet the currently high need for de-hospitalization by making different types of care and care concepts available. Five groups of patients with chronic schizophrenic psychoses (N = 245 patients) who live in different types of psychiatric care facilities (psychiatric nursing home, social therapeutic hostel, sheltered community residence) or at home, either with or without a family network, were studied. In addition to the sociodemographic data, the psychopathology and the extent of social disabilities were also surveyed, as well as data on the living situation and the subjective quality of life with an emphasis on ‘social relationships’, ‘recreation/leisure activities’, and ‘general independence’.

The five groups differed with regard to various sociodemographic and disorder-related variables, particularly with regard to the extent of social disabilities. Especially relevant, however, are the differences among the patient groups in the extent of daily social life and recreational/leisure activities that are partially reflected in their statements on the subjective quality of life. Primarily for the two groups of home residents, but also in part for the patients living in sheltered community care, social contacts are more or less limited to the residential situation and patients are more or less otherwise socially isolated. This is due among other things to the fact that patients who have been hospitalized for long periods do not as a rule return to their prior area of residence; thus, the available compensatory mediation of relationships with the social environment does not suffice. Demands for the further development of complementary systems of psychiatric care derive from these findings.
Alcoholism and drug addictions
Authors: Hoes MJAJM
Published: July 2002

In this symposium the nature, epidemiology and extent of psychiatric disorders comorbid with addictions, especially alcoholism, was exposed. Internationally reknown authors from several European countries highlight the diversity and complexity of this problem in particular for depression, anxiety and suicide. The conclusion is that every psychiatrist should be well acquainted with addiction disorders and that no addiction center be allowed to refuse treatment to patients with a psychiatric comorbid disorder. Comorbidity of schizophrenia with addictions should be a future focus of research. Multicultural Europe is an exciting area for further research of the comorbidity problems.
Ideology and ethics. The perversion of German psychiatrists' ethics by the ideology of national socialism
Authors: Singer L
Published: July 2002

As soon as Adolf Hitler came to into power in 1933, four laws on racial segregation and race protection were edicted between 1934 and 1935. Schizophrenia, manic-depressive psychoses, epilepsy and alcoholism were regarded as hereditary mental illnesses. These laws were responsible for the sterilisation of 350,000 individuals who were thought to be at the source of the propagation of hereditary illnesses which might endanger the health and the future of the Aryan Germans. On September 1, 1939, Action T4 was launched: it required that all the mentally ill be exterminated. This action, which was run by the highest level of the Reich's chancellery with the help of psychiatrists coming from all backgrounds including university professors, was supposed to grant a serene death to all the mentally ill considered as untreatable. The death sentences were carried out by the medical staff in psychiatric hospitals specially equipped with gas chambers. Following protests, Action T4 was officially stopped on August 24, 1941, but, in reality, continued until the end of the war. The death sentences were carried out using either lethal doses of medication or food deprivation. One hundred and fifty thousand individuals fell victim to that therapeutic extermination which played an economic role as important as the one deemed to social protection. Many German academics, researchers, psychiatrists, geneticians and anthropologists played and active part in these murders which were carried out in the name of Nazi ideology based upon the supremacy of the Northern Germanic race and the necessity to protect it from miscegenation, especially from Jews. In the final part of this paper, the author gives an explanation of the perversion of ethics carried out by German psychiatrists.
Heart failure in patients seeking medical help at outpatients clinics. Part I. General characteristics
Authors: Rywik Stefan L. , Wągrowska Henryka , Broda Grażyna , Sarnecka Aleksandra , Pytlak Aleksandra , Polakowska Maria , Drewla Joanna , Korewicki Jerzy
Published: July 2002

Background

During the last decade, the beneficial changes in lifestyle and in medical care increased average life expectancy, particularly in patients with chronic diseases such as hypertension and coronary heart disease. Unfortunately this also increased the number of patients, particularly among the elderly, who are susceptible to complications of these conditions such as heart failure. Uncontrolled hypertension is known to be a primary cause of heart failure and is also known to be very prevalent and frequently uncontrolled in the Polish population.

Aim

To estimate the prevalence and characteristics of heart failure among patients of 65 years and older seeking medical care in outpatient clinics in Poland.

Methods

The study is a cross‐country epidemiological project in which 417 physicians from outpatient clinics were asked to register 50 consecutive patients aged 65 years and above seeking medical care for any cause. Information on case history, physical examination (diagnosis of heart failure, NYHA class, heart failure symptoms), laboratory tests (resting ECG, chest X‐ray, echocardiogram) and data concerning pharmacology management during the 2 weeks prior to the index visit was obtained.

Results

Over 5 months, 19877 eligible patients (7324 men and 12553 women) presented to the 417 participating physicians (90% physicians registered 46–50 patients). Among the patients, 53% were diagnosed with heart failure (3901 men and 6678 women), prevalence did not differ by gender. Among patients with heart failure there were 38% of men in NYHA class III or IV and 34% of women. Coronary heart disease was a predominant cause of heart failure in 87% of men (26% of cases with isolated coronary heart disease, 53% with concomitant hypertension and 8% with other diseases), while percentages for women were 80% (15%, 61% and 4%, respectively). Isolated hypertension was a further cause of heart failure in 8% of men and 13% of women. Cardiac arrhythmia was found in approximately 20% of patients, enlargement of heart size in 32% of patients and peripheral leg edema in 54% of men and 64% of women. These symptoms increased with age. Chest X‐ray revealed cardiomegaly in 68% of men and women and increased cardiothoracic ratio (>50%) in approximately 40% of patients. From resting ECGs, cardiac arrhythmia was recorded in 21% of patients with heart failure, with atrial fibrillation as a predominant disorder (19%). Left ventricular hypertrophy on resting ECG was noted in 42% of men and women and old myocardial infarction or cardiac ischemia was diagnosed in 71% of men and 66% of women.

Conclusions

(1) Heart failure was diagnosed in over half of outpatients aged 65 and older; in more than a third of these it was NYHA class III and IV. (2) Outpatients with heart failure had a high frequency of co‐existing diseases such as arrhythmia, coronary heart disease and hypertension.