bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluación de variables cardiovasculares en una población calchaquí de media y alta montaña de Tucumán
Authors: Holownia Damián , Palavecino Darío Omar , Abregú José Daniel , Rivas Jordán María Silvina , Silva Frias Magdalena , Rossi Agustina , Iglesias Norma , Chahla Rossana , Joo Turoni Claudio
Published: April 2021

Introducción: La comunidad Quilmes (Tucumán) abarca 2400 habitantes de media y alta montaña (1800 a 4000 metros sobre el nivel del mar). El objetivo del presente trabajo fue conocer su estado de salud cardiovascular. Material y métodos: Se efectuó una investigación cuantitativa descriptiva transversal en personas pertenecientes a dicha comunidad que asistieron voluntariamente en los días 27 a 29 de septiembre de 2018 a la evaluación prevista. Resultados: Se estudiaron 202 pobladores (125 mujeres y 77 varones; 48 ± 1,4 años). El 23% de ellos tenían hipertensión arterial (HTA); un 14% eran tabaquistas; el 4,9% tenían diabetes (DBT); el 18% presentaba dislipidemia (DLP); el 25% consumía alcohol rutinariamente (1,0 ± 0,4 L/día). Asimismo, el 29% presentaba sobrepeso y el 36% obesidad. Se registró presión arterial (PA) elevada en 48 personas al momento del estudio. La PA disminuyó en la tercera toma con respecto a la primera, pero la frecuencia cardíaca aumentó en la tercera toma (74 ± 1 latidos por minuto vs. 77 ± 1; p <0,01). La saturación de O2 (95,0 ± 0,2%) se correlacionó negativamente con la edad (Pearson r: −0,266; p <0,001). En los pobladores con PA normal, la relación E/A determinada ecográficamente fue mayor (1,2 ± 0,0) y el espesor de la pared posterior del ventrículo izquierdo fue menor (8,5 ± 0.5 mm) que en aquellos con PA elevada (0,92 ± 0,1 y 9,0 ± 0.3, respectivamente, p <0,001). El 24% presentó placas ateroscleróticas y 120 pobladores presentaron DLP. Conclusiones: La población Quilmes presenta una prevalencia de factores de riesgo cardiovascular similar a la de centros urbanos, los que podrían llevar en los próximos años a un incremento de la morbimortalidad cardiovascular en esta población
¿La colchicina puede prevenir el infarto agudo de miocardio? Revisión sistemática y metaanálisis
Authors: Masson Walter , Lobo Martín , Lavalle Cobo Augusto , Molinero Graciela
Published: April 2021

Introducción y objetivos: La asociación entre el uso de colchicina y la incidencia de infarto agudo de miocardio (IAM) es heterogénea. El objetivo principal del presente estudio fue evaluar el efecto de la colchicina sobre la incidencia de IAM. La evaluación de la incidencia de accidente cerebrovascular (ACV) y la mortalidad cardiovascular fueron los objetivos secundarios. Material y métodos: Se realizó un metaanálisis de estudios aleatorizados que evaluaron el uso de colchicina en pacientes con enfermedad aterosclerótica y que reportaron los eventos cardiovasculares, luego de una búsqueda en las bases de datos PubMed/MEDLINE, Embase, Scielo y Cochrane Controlled Trials. Se utilizó un modelo de efectos fijos o aleatorios según la heterogeneidad observada. Resultados: Se seleccionaron para el análisis del punto final primario 7 estudios (con un total de 5966 sujetos en la rama colchicina y 5948 pacientes en la rama control). Este metaanálisis demostró que la terapia con colchicina se asoció a un menor riesgo de IAM (OR: 0,76, IC 95%: 0,62-0,92; I2 =15%). Asimismo, se observó una reducción significativa en la incidencia de ACV, sin un efecto significativo en la mortalidad cardiovascular, con la intervención farmacológica. Conclusión: El uso de colchicina en pacientes con enfermedad cardiovascular aterosclerótica se asoció a una reducción significativa en la incidencia de IAM. La incorporación de la colchicina dentro del arsenal terapéutico de la enfermedad cardiovascular deberá ser considerada por las futuras guías de práctica clínica.
Estado actual de la Rehabilitación Cardiovascular en Argentina
Authors: Zeballos Cecilia , Iglesias Diego , Paz Ivana , Bustamante Julieta , González Naya Enrique , Castiello Gustavo , Davolos Ignacio
Published: April 2021

Introducción: La rehabilitación cardiovascular es una reconocida estrategia de prevención secundaria para el tratamiento de numerosas cardiopatías. Es una herramienta multicomponente donde se incluyen la educación en un estilo de vida saludable, control de los factores de riesgo, asesoramiento en aspectos psicosociales y la prescripción supervisada del ejercicio físico. Numerosos ensayos clínicos, revisiones sistemáticas y metaanálisis han demostrado su eficacia y seguridad. Sin embargo, sigue siendo una herramienta subutilizada. Existen datos descriptivos de cómo se lleva a cabo la rehabilitación cardiovascular y las características de los centros que la implementan de varios países europeos y de Norteamérica. A nivel sudamericano en su conjunto, contamos con datos reportados en el año 2014 y otros provenientes de Brasil, Colombia y Uruguay. Pero existen escasos datos provenientes de nuestro país, por ello el objetivo de este estudio se centró en conocer la situación actual de los programas de rehabilitación cardiovascular en Argentina. Material y métodos: Se trata de un estudio descriptivo, realizado por medio de un cuestionario virtual que evalúa la estructura y características de los programas de rehabilitación de nuestro país y las potenciales barreras para una rehabilitación eficiente. Resultados: Respondieron 72 centros. Los principales resultados muestran gran concentración de centros en áreas urbanas (69,23% en el AMBA), predominancia de centros privados (66,67%) inclusión de pacientes con patologías cardiovasculares denominadas como clásicas (enfermedad coronaria, insuficiencia cardíaca, posoperatorios valvulares, enfermedad vascular periférica, postrasplante cardíaco y poscolocación de dispositivos), y predominancia de centros con estrategia centrada en el ejercicio. La principal dificultad a la hora de la inclusión de pacientes a los centros es la escasa referencia de los candidatos. Conclusiones: Los datos de esta encuesta permiten hacer un diagnóstico de situación, y pueden ser el punto de partida para estrategias de mejora, que permitan implementar estándares de calidad y en un futuro establecer programas de acreditación de centros
Comparative Studies of the Shear Strength Property of Two Members of the Fabaceae Family with Respect to Their Fibres
Authors: Nweze A. E. , Ojua E. O. , Ajuziogu G. C. , Ngele I. E.
Published: April 2021

Aim: The shear strength of wood is a very significant parameter required in describing the potential of woods in making wooden structure. This study is aimed at comparing the shear strength of Pentaclethra macrophylla and Erythrophleum suaveolens with respect to their fibre. This is to determine the suitability of including Erythrophleum suaveolens in making traditional motars in order to reduce the demand load on Pentaclethra macrophylla.

Methods: The heartwood samples of Pentaclethra macrophylla and Erythrophleum suaveolens for maceration were fixed in specimen bottles containing formalin-acetic-alcohol (FAA) in the ratio 90:5:5 to prevent fungal growth. The preparations involved cutting small clear samples of the heartwood of the two timber species of fabaceae family. The shear strength parallel to the grain test was conducted using a Hounsfield Tensometer.

Results: Significant differences were recorded across the fibre characteristics of the two plant species. The share strength of the 25 wood samples from the two plants each fluctuate around 100 to 200 N/mm2.  On the average, P. macrophylla recorded higher shear strength as compared to

suaveolens however no significant difference was recorded between the means when tested for significant differences using independent sample t-test.

Conclusion: Since the shear strength of E. suaveolens is comparable to that of P. macrophylla, it  is therefore recommended its substitute for the manufacturing of wood based products where P. macrophylla has been in continual usage in order to relieve the pressure and demand on P. macrophylla.
Evaluation of Household Water, Sanitation, and Hygiene Management in a Nigerian Rural Community
Authors: Wada Ojima Zechariah , Olawade David Bamidele , Asogbon Omotayo , Makinde Fiyinfoluwa Taiwo , Adebayo Ismaeel
Published: April 2021

The Water, Sanitation, and Hygiene (WASH) disparities between the rural and urban areas have hindered the Sustainable Development Goal 6. Recent data is required in our bid to tackle this menace effectively. This study aimed to provide data on the status of household WASH facilities in a remote village in Southwestern Nigeria. The survey was cross-sectional in design, and total sampling was used to select 70 household respondents. Data were obtained via observational checklists, questionnaire, and key informant interview guide. Data was entered and analyzed using SPSS 20. Descriptive statistics like measures of frequency and proportions were used. The respondents had a mean age of 43.1 ± 16.4 years, only 2.9% had tertiary education. The village had two handpump boreholes provided by the Water Supply and Sanitation Sector Reform Programme (WSSSRP)-II. All the respondents reported that the boreholes were their primary drinking water source, and water was available all through the year. In over 80% of households, females were assigned the duty to fetch water, while most households had the boreholes within 30 minutes from their houses. The sanitation facilities were also provided via the WSSSRP-II. The majority (90%) of the respondents owned pit latrine with slab, of which only 10% shared their facilities with other households. Most (95.7%) of the respondents still practised open defecation at instances they could not access their household latrines. All the toilets had water for handwashing, and the soap commonly used by community members was palm kernel ash. The condition of water and sanitation in the village was quite progressive. However, subsequent interventions should ensure toilet facilities are available in non-household settings like farms and markets.
Diatoms Flora from a Shallow Reservoir in Ivory Coast
Authors: Kouassi Blé Alexis Tardy , Komoé Koffi , Adon Marie Paulette , Ouattara Allassane
Published: April 2021

The diatoms flora of Adzopé Reservoir in Côte d’Ivoire was investigated from January to December 2005. The species composition of the assemblage was compiled, accompanied by illustrations. Firty-one taxa were identified in the temporal survey. Five taxa (16.3%) were new for Côte d’Ivoire. Eleven common species, 9 occasional taxa and 11 rare taxa were also recorded. No spatial variations in the taxonomic composition of the populations of diatoms were found. Variations were encountered in the seasonal analysis. Variation in the dimensions of some identified taxa have been observed. The species richness of Diatoms in the Adzopé Reservoir was in relation with water current velocity.
Dder einfluss von liganden auf den assoziationsgrad des desoxy‐hämoglobins der flussneunaugen (lampetra fluviatilis L.)
Authors: Behlke J. , Scheler W.
Published: July 2002

In alkaline aqueous solution, the sedimentation coefficients of DeoxyHb, HbO2 and HbCO of Lampetra fluviatilis L. are 1.9 ± 0.1 S. This value corresponds to a molecular weight of about 17,000, i.e. the value of a single haem polypeptide chain. In weak acidic conditions, both the non‐liganded DeoxyHb and the liganded forms, HbO2 and HbCO, associate to form dimers and oligomers. The monomer‐oligomer transitions of these compounds take place at different pH values: DeoxyHb pHO.5 ∼ 6.7; HbO2 and HbCO pHO.5 ∼ 5.9. With respect to the association modus, the equilibrium: 4 Hb ⇌ 2 Hb2⇌Hb4 may be preferred.
Insulin binds to and promotes the phosphorylation of a Mr 210 000 component of its receptor in detergent extracts of rat liver microsomes
Authors: Blackshear Perry J. , Nemenoff Raphael A. , Avruch Joseph
Published: July 2002

Insulin in the presence of Mn2+ and [γ32P]ATP promoted the phosphorylation of two proteins of M
r 95 000 and M
r 210 000 in detergent extracts of rat liver microsomes. The M
r 210 000 protein was identified as a component of the insulin receptor by immunoprecipitation. It also bound [125I]insulin specifically, was phosphorylated largely on a tyrosine residue and could not be cleaved to smaller subunits under extreme reducing conditions. The M
r 210 000 protein appears to be a component of a sub‐population of liver membrane insulin receptors in which insulin‐binding and insulin‐stimulated tyrosine kinase phosphorylation site(s) reside in a single polypeptide chain.
Enzyme specificity: base recognition and hydrolysis of RNA by ribonuclease A
Authors: Borkakoti Nivedita
Published: July 2002

The substrate specificity of pancreatic ribonuclease A is discussed in light of observations based on accurate X‐ray structure analysis of several enzyme—nucleotide complexes. A hypothesis for protein—nucleic acid recognition is presented which proposes that: (a) pyrimidine bases in RNA are recognised by ribonuclease due to the charge complementarity of two groups (the amide nitrogen and the side chain oxygen (OG) of threonine 45) of the protein and relevant atoms in the heterocyclic base (O2 and N3 in pyrimidine nucleotides); (b) interaction of the protein with the ribose moiety of the nucleotides is non‐specific; and (c) conformational flexibility in the region of the scissile PO bond is provided by different locations of the phosphoryl oxygens, rather than by an overall translation of the phosphate moiety.
Citrate synthase of Escherichia coli
Authors: Robinson Martin S. , Easom Richard A. , Danson Michael J. , Weitzman P.D.J.
Published: July 2002

Guest [J. Gen. Microbiol. (1981) 124, 17–23] has cloned the citrate synthase gene from E. coli into ColE1 plasmids. This plasmid‐coded enzyme has now been purified and characterised and shown to be indistinguishable from the chromosome‐coded enzyme in molecular, catalytic and regulatory properties. The plasmid copy number has been raised to > 200/cell by treatment with chloramphenicol and the effects of this increase on the intracellular level of citrate synthase have been investigated.
Evidence for coordinated phosphorylation of keratins and vimentin during mitosis in transformed human amnion cells
Authors: Fey Stephen J. , Larsen Peter Mose , Celis Julio E.
Published: July 2002

Two‐dimensional gel electrophoresis (IEF) analysis of short‐term [32P]orthophosphate‐labelled intermediate‐sized filament proteins (keratins and vimentin) from transformed mitotic amnion cells (AMA), have shown that these proteins are modified coordinately and that the half life of the phosphate is about 13 min for the keratins and 11 min for vimentin. These results support the notion that the preferential modification of intermediate‐sized filament proteins during mitosis may play a role in modulating filament associations with organelles and other cellular structures.
Molecular mass analysis of murine immunosuppressive immunoglobulin G‐binding factors (IgG‐BFs) produced by T‐cell hybrids
Authors: Néauport-Sautès Catherine , Gelabert Maria-José , Moncuit Janine , Fridman Wolf Herman
Published: July 2002

Induced and constitutive murine IgG‐binding factors (IgG‐BFs) have been purified by affinity chromatography from supernatants of T‐cells preincubated with or without murine monoclonal IgG1 and IgG2b, respectively. IgG‐BF M
r values have been studied by SDS‐polyacrylamide gel electrophoresis (PAGE) after treatment with SDS under conditions which do not noticeably alter their immunosuppressive activities on the secondary in vitro IgG antibody response. Suppression was recovered at M
r values of 80000, 40000 and 20000. When induced IgG‐BF was tested, the isotype‐specific suppressive activity was found only at 40 kDa. The 20‐kDa moiety appeared to derive from the 40‐kDa component and the material found at 80 kDa exerted non‐specific immunosuppressive effects. We conclude therefore that isotype‐specific IgG‐BF has an apparent M
r of 40000.
Determination of the size of the packing defects in dimyristoylphosphatidylcholine bilayers, present at the phase transition temperature
Authors: van Hoogevest Peter , de Gier Johannes , de Kruijff Ben
Published: July 2002

Multilamellar liposomes of dimyristoylphosphatidylcholine, containing 4 mol% egg phosphatidic acid show at the phase transition temperature an increased permeability for non‐electrolytes of M
r values up to 900. This indicates that the packing defects occurring at the liquid crystalline/gel state phase boundary have a similar pore diameter (15–18 A) as the packing defects present in glycophorin—dioleoylphos‐phatidylcholine vesicles. This suggests that packing defects at the protein—lipid interphase are the major permeation pathway of the glycophorin—dioleoylphosphatidylcholine vesicles.
Computer graphics modelling of human renin
Authors: Sibanda Bancinyane L. , Blundell Tom , Hobart Peter M. , Fogliano M. , Bindra Jasjit S. , Dominy Beryl W. , Chirgwin John M.
Published: July 2002

A model has been constructed using computer graphics for human renin based on the sequence derived from that of the gene and the 3‐dimensional structure defined at high resolution for other homologous aspartic proteinases. Human renin can adopt a 3‐dimensional structure close to that of other aspartic proteinases, in which amino acids corresponding to intron‐exon junctions in the gene are at surface regions in the 3‐dimensional structure. As expected, the essential catalytic residues are retained and the nearby residue 304 is alanine as in the mouse sequence, supporting the idea that Asp 304 of other aspartic proteinases may contribute to the low pH of their optimal activity. There are interesting differences at subsite S'3 which may contribute to the specificity of human renin. Certain residues at the surface of the enzyme adjacent to the active site cleft are unique to renins and may play a role in recognition and binding of angiotensinogen.
Evidence that acid solutions induce plant cell elongation by acidifying the cytosol and stimulating the proton pump
Authors: Brummer Benno , Felle Hubert , Parish Roger W.
Published: July 2002

Acid‐induced growth
Cell wall acidification
Cytosolic acidification
Indoleacetic acid
Membrane potential
Zea mays
Equilibrium of conformers in solution: spin‐labelled angiotensin
Authors: Vesterman B. , Sekacis I. , Bētiņš J. , Podiņš L. , Nikiforovich G.V.
Published: July 2002

The number of structural parameters were determined for spin‐labelled angiotensin in aqueous solution with the use of fluorescence spectroscopy and 1H NMR relaxation induced by the spin label. At the same time all measured parameters were estimated theoretically by means of energy calculations and Monte‐Carlo techniques. The matching procedure for experimental and computational data allows one to suggest a dynamic equilibrium between conformers of the molecule in aqueous solution and to estimate the values of their weights.
Mechanisms responsible for carbon tetrachloride‐induced perturbation of mitochondrial calcium homeostasis
Authors: Albano E. , Bellomo G. , Carini R. , Biasi F. , Poli G. , Dianzani M.U.
Published: July 2002

Incubation of isolated hepatocytes with CCl4 results in early reduction of the intracellular calcium content, mostly due to loss from the mitochondrial compartment. CCl4 treatment directly affects mitochondrial functions as indicated by the inhibition of Ca2+ uptake in cells permeabilized to the ion by digitonin exposure and by the reduction of intracellular ATP content in hepatocytes incubated in a glucose‐free medium. Such mitochondrial damage is not caused by CCl4‐induced stimulation of lipid peroxidation since it is not prevented by α‐tocopherol, used at a concentration able to inhibit completely peroxidative reactions without interfering with CCl4 activation. All data together are in favour of a direct action of CCl4‐reactive metabolites on liver cell calcium homeostasis.
Energy transfer within the isolated light‐harvesting chlorophylla/bprotein of photosystem II (LHC‐II)
Authors: Gillbro Tomas , Sundström Villy , Sandström Åke , Spangfort Michael , Andersson Bertil
Published: July 2002

Picosecond absorption spectroscopy has been used to study energy transfer within the isolated light‐harvesting chlorophylla/bprotein complex of photosystem II (LHC‐II). The results suggest: (i) a fast transfer (τ = 6 ± 4 ps) from chlorophyllbto chlorophylla, (ii) during the lifetime of the chlorophyllbexcited state there is no transfer of excitation energy between differently oriented molecules of chlorophyllb, (iii) a fast redistribution (τ = 20 ps) of excitation energy between different chlorophyllachromophores.
The effect of a rat plasma high‐density lipoprotein subfraction on the synthesis of bile salts by rat hepatocyte monolayers
Authors: Ford Robert P. , Botham Kathleen M. , Suckling Keith E. , Boyd George S.
Published: July 2002

The effect of a rat high‐density lipoprotein subfraction (HDL2) on the synthesis of bile salts by rat hepatocyte monolayers prepared from rats fed a diet containing cholestyramine, was investigated. The synthesis of bile salts as measured by radioimmunoassay of conjugated cholic, chenodeoxycholic and β‐muricholic acids was significantly increased when hepatocytes were incubated with a physiological concentration (500 μg HDL, protein·ml−1) of HDL2.
The effect of 2,4,6‐trinitrobenzenesulfonate on mercuric reductase, glutathione reductase and lipoamide dehydrogenase
Authors: Carlberg Inger , Sahlman Lena , Mannervik Bengt
Published: July 2002

Among the three closely related enzymes, lipoamide dehydrogenase, mercuric reductase, and glutathione reductase only the latter is inhibited by 2,4,6‐trinitrobenzenesulfonate (TNBS). On the other hand, all three enzymes exhibit high rates of TNBS‐dependent NADPH oxidation. In the case of glutathione reductase and mercuric reductase this TNBS‐dependent activity displays substrate inhibition by excess of NADPH and is strongly stimulated by NADP+. The stimulation is especially pronounced with mercuric reductase, 25‐fold under some conditions. Neither substrate inhibition nor stimulation by NAD+ is observed with lipoamide dehydrogenase.
Characterization of the sites phosphorylated on tyrosine hydroxylase by Ca2+ and phospholipid‐dependent protein kinase, calmodulin‐dependent multiprotein kinase and cyclic AMP‐dependent protein kinase
Authors: Vulliet P.Richard , Woodgett James R. , Ferrari Stefano , Hardie D.Grahame
Published: July 2002

Tyrosine hydroxylase purified from rat pheochromocytoma is phosphorylated rapidly by the Ca2+‐ and phospholipid‐dependent protein kinase (protein kinase C) purified from rat or sheep brain. Phosphorylation was stimulated 14‐fold by Ca2+ and phosphatidylserine and occurred at a rate comparable with that of the phosphorylation of histone H1. The phospholipid‐dependent protein kinase phosphorylates a single site which is identical to that phosphorylated by cyclic AMP‐dependent protein kinase and to the secondary site of phosphorylation by the calmodulin‐dependent multiprotein kinase. The implications of these results with respect to the regulation of catecholamine biosynthesis in adrenal medulla are discussed.
Phorbol ester stimulates catecholamine synthesis in isolated bovine adrenal medullary cells
Authors: Houchi Hitoshi , Nakanishi Atsushi , Uddin Mir Misbah , Ohuchi Takeshi , Oka Motoo
Published: July 2002

In isolated bovine adrenal medullary cells, the phorbol ester 12‐O‐tetradecanoyl phorbol 13‐acetate (TPA), an activator of protein kinase C, stimulated [14C]catecholamine synthesis from [14C]tyrosine, but not from [14C]DOPA. This stimulatory effect of TPA on [14C]catecholamine synthesis was not dependent upon extracellular Ca2+, and TPA did not affect the uptake of 45Ca2+ or the release of catecholamine by the cells. TPA also did not affect the intracellular cyclic AMP (cAMP) level. 4α‐Phorbol 12,13‐didecanoate, which is not an activator of protein kinase C, did not stimulate the synthesis of [14C]catecholamine from [14C]tyrosine. The stimulatory effect of TPA on [14C]catecholamine synthesis was additive with that of carbamylcholine, but not with that of dibutyryl cAMP (DB‐cAMP). From these results, it was suggested that protein kinase C is involved in the regulation of tyrosine hydroxylase activity and that this regulatory mechanism might be similar to that involving cAMP.
Regulation of [3H]forskolm binding to human platelet membranes by GppNHp, NaF, and prostaglandin E1
Authors: Nelson Carol A. , Seamon Kenneth B.
Published: July 2002

Displaceable binding of [3H]forskolin to human platelet membranes can be detected in the presence of magnesium. There is an increase in the number of [3H]forskolin binding sites when membranes are incubated with GppNHp or NaF in the presence of magnesium. Prostaglandin E1, which stimulates human platelet adenylate cyclase, does not affect the binding of [3H]forskolin in the absence of GppNHp. However, the dose‐response curve for the GppNHp‐dependent increase in [3H]forskolin binding sites is shifted to lower concentrations in the presence of prostaglandin E1. Prostaglandin E1 potentiates the effect of GppNHp on [3H]forskolin binding most likely by facilitating the binding of the guanine nucleotide at the stimulatory quanine nucleotide regulatory protein of adenylate cyclase.
Catalysis of plastocyanin electron self‐exchange by redox‐inert multivalent cations
Authors: Armstrong Fraser A. , Driscoll Paul C. , Allen H. , Hill O.
Published: July 2002

Plastocyanin
Electron self‐exchange
NMR
Protein‐protein interaction
Multivalent cation
Blue copper protein
Incorporation of synthetic 1,2‐diacylglycerol into platelet phosphatidylinositol is increased by cyclic AMP
Authors: Lapetina Eduardo G.
Published: July 2002

1,2‐Didecanoylglycerol (diC10) is taken up by human platelets and sequentially converted to 1,2‐didecanoyl‐phosphatidic acid (PA10) and 1,2‐didecanoylphosphatidylinositol (PI10). Agents that increase cyclic AMP in platelets, such as prostacyclin and forskolin, sequentially convert diC10 to pa10 and PI10. They decrease formation of PA10 with a parallel accumulation of PI10. This might reflect an inhibition of phosphatidylinositol kinase.
Organization of the human genes for insulin‐like growth factors I and II
Authors: de Pagter-Holthuizen P. , van Schaik F.M.A. , Verduijn G.M. , van Ommen G.J.B. , Bouma B.N. , Jansen M. , Sussenbach J.S.
Published: July 2002

Recently, we have reported the isolation of cDNAs encoding the precursors of insulin‐like growth factors I and II (IGF‐I and II) [(1983) Nature 306, 609‐611; (1985) FEBS Lett. 179, 243‐246. These cDNAs were employed as specific probes to detect and isolate the corresponding genes from human cosmid DNA libraries. Three cosmids were detected, together containing the entire cDNA sequence of IGF‐I, and one cosmid containing the sequence of IGF‐II cDNA. Southern blot hybridization, physical mapping and nucleotide sequence analysis of these cosmids revealed that the IGF‐I and ‐II genes have a discontinous structure. The IGF‐I gene contains at least four exons spanning a region of probably more that 45 kilobasepairs (kb), while the IGF‐II gene consists of at least five exons, spanning a region of 16 kb.
Extensive homologies between lectins from non‐leguminous plants
Authors: Chapot M.-P. , Peumans W.J. , Strosberg A.D.
Published: July 2002

Sequence studies were performed on lectins from two non‐leguminous plants: rice and nettle. Extensive homologies were found between these two proteins and wheat germ agglutinin in support of the conservation of lectin sequences among non‐leguminous plants. The number and positions of the cysteine residues were particularly well conserved suggesting a similar folding of the polypeptide chains.
Selective phosphorylation of human DNA methyltransferase by protein kinase C
Authors: DePaoli-Roach Anna , Roach Peter J. , Zucker Keith E. , Smith Steven S.
Published: July 2002

Human DNA methyltransferase, the enzyme thought to be responsible for the somatic inheritance of patterns of DNA methylation, is an effective substrate for phosphorylation by protein kinase C. This provides a plausible mechanistic link between the action of tumor promoting phorbol esters, which stimulate protein kinase C, and abnormal patterns of DNA methylation often observed in transformed cells.
Homology with hemopexin suggests a possible scavenging function for S‐protein/vitronectin
Authors: Stanley K.K.
Published: July 2002

S‐protein is an abundant plasma protein which has recently been shown to be identical to vitronectin and serum spreading factor [(1985) EMBO J. 4, 3153‐3157]. It therefore has multiple binding sites for terminal complement complexes, thrombin‐antithrombin III, heparin, and a specific cell receptor. In this report a structural and sequence homology with hemopexin is described which suggests that the principle function of S‐protein could be as a scavenging molecule, clearing spent complement and coagulation complexes from the circulation
Free fatty acids decouple oxidative phosphorylation by dissipating intramembranal protons without inhibiting ATP synthesis driven by the proton electrochemical gradient
Authors: Rottenberg Hagai , Steiner-Mordoch Sonia
Published: July 2002

Free fatty acids (FFA) uncouple oxidative phosphorylation and reverse electron transport and inhibit ATP‐Pi exchange in beef heart submitochondrial particles. In this, they resemble classical uncouplers and ionophores. However, in contrast to the latter agents, FFA do not collapse the substrate generated proton electrochemical potential and do not inhibit ATP synthesis when the latter is driven by artificially imposed H. These results lend further support to the suggestion that oxidative phosphorylation depends, in part, on direct intramembranal proton transfer ‐ a process which is specifically uncoupled by FFA and other membrane perturbing agents (e.g. general anesthetics).
Evidence of a small hydrophobic domain in the core protein of the heparan sulfate proteoglycan from human colon carcinoma cells
Authors: Iozzo Renato V. , Ketterer Cynthia L. , Slaymaker Diana J.
Published: July 2002

We demonstrate that the cell surface heparan sulfate proteoglycan of human colon carcinoma cells has an affinity for a hydrophobic matrix. This property is mediated by sequences in the core protein, since papain‐or alkaline borohydride‐released heparan sulfate chains do not bind to the matrix. Trypsin releases a [3H]leucine‐rich, unsulfated, hydrophobic peptide, with M
r ~ 5000. This domain is present in neither the proteoglycan released into the medium nor in the intracellular degradation products. It is proposed that this peptide may represent the portion of the core protein intercalated into the plasma membrane.
Detection of a new chloroperoxidase in Pseudomonas pyrrocinia
Authors: Wiesner Wolfgang , van Pee Karl-Heinz , Lingens Franz
Published: July 2002

A new chloroperoxidase could be detected in Pseudomonas pyrrocinia ATCC 15 958, a bacterium that produces the antifungal antibiotic pyrrolnitrin. This enzyme was separated from a ferriprotoporphyrin IX containing bromoperoxidase which was also produced by this bacterium. The enzyme is capable of catalyzing the chorination of indole to 7‐chloroindole. This procaryotic chloroperoxidase requires the presence of H2O2 and can also brominate monochlorodimedone, but cannot catalyze its chlorination. This enzyme is the first chloroperoxidase described from procaryotic sources.
A mouse renin promoter containing the conserved decanucleotide element binds the same B‐cell factors as an authentic immunoglobulin heavy chain promoter
Authors: Ekker Marc , Doyen Noelle , Leblond-Francillard Marie , Rougeon François
Published: July 2002

A mouse renin‐1 gene promoter fragment, normally inactive in B‐cells, becomes a potent promoter in these cells after insertion of the highly conserved decanucleotide (dc/cd sequence) of immunoglobulin heavy and light chain promoters [(1987) EMBO J. 6, 1685–1690]. We observe retarded complexes of the same electrophoretic mobility when the cd‐containing renin promoter fragment or an authentic immunoglobulin heavy chain promoter fragment is incubated with a nuclear extract from myeloma cells, suggesting that the renin promoter is activated due to its acquired ability to bind a B‐cell‐specific positive factor. No retarded complexes are observed with the original renin promoter fragment thus questioning the presence of a repressor as an explanation for its lack of activity in B‐cells.
Cyclin (PCNA, auxiliary protein of DNA polymerase δ) is a central component of the pathway(s) leading to DNA replication and cell division
Authors: Celis Julio E. , Madsen Peder , Celis Ariana , Nielsen Henrik V. , Gesser Borbala
Published: July 2002

Cyclin, also known as PCNA or the auxiliary protein of mammalian DNA polymerase δ, is a stable cell cycle regulated (synthesized mainly in S‐phase) nuclear protein of apparent M
r 36 000 whose rate of synthesis correlates directly with the proliferative state of normal cultured cells and tissues. Cyclin (PCNA) is absent or present in very low amounts in normal non‐dividing cells and tissues, but it is synthesized in variable amounts by proliferating cells of both normal and transformed origin. All available information indicates that this ubiquitous and tightly regulated DNA replication protein is a central component of the pathway(s) leading to DNA replication and cell division.
Molecular mechanism underlying impaired platelet responsiveness in liver cirrhosis
Authors: Laffi Giacomo , Cominelli Fabio , Ruggiero Mareo , Fedi Sandra , Chiarugi Vincenzo , Gentilini Paolo
Published: July 2002

We have studied platelet function in 10 patients with severe liver cirrhosis, compared to healthy subjects. Using washed platelets, we have investigated the molecular mechanism underlying the defect in platelet aggregation frequently observed in these patients. We have found that platelets from cirrhotic patients have a reduced responsiveness to thrombin and collagen in terms of aggregation, and receptor‐dependent activation of phospholipase C, A2 and cyclooxygenase/thromboxane synthetase. We thus suggest that this impairment in transmembrane signalling is responsible for the defective platelet function observed in cirrhosis.
Ca‐dependent‐chloride and potassium currents in rat Leydig cells
Authors: Duchatelle Pascal , Joffre Michel
Published: July 2002

Voltage‐clamped membrane currents have been investigated from whole‐cell patch‐clamp recordings performed on single Leydig cells isolated from the adult rat testis. Two outward membrane currents were evoked by depolarizing voltage steps. A potassium current was recorded in cells dialyzed with low (10−9−10−8 M) calcium media. This current was decreased by TEA (10 mM). A chloride current was recorded in cells dialyzed with high (10−7 − 10−6 M) calcium media. This current was decreased by an external exposure to glutamate. Comparison of the currents at low and high internal calcium concentrations suggests that an increase of the intracellular calcium activates a chloride current.
Chromogranin A can act as a reversible processing enzyme inhibitor
Authors: Seidah N.G. , Hendy G.N. , Hamelin J. , Paquin J. , Lazure C. , Metters K.M. , Rossier J. , Chrétien M.
Published: July 2002

Bovine parathyroid chromogranin A inhibits the cleavage of Z‐Ala‐Lys‐Arg‐AMC by either trypsin or IRCM‐serine protease 1 (IRCM‐SP1), a putative novel processing enzyme originally isolated from porcine pituitary anterior and neurointermediate lobes. On larger substrates, chromogranin A is a reversible competitive inhibitor of the cleavage at pairs of basic amino acids by IRCM‐SP1. The substrates tested included pituitary ACTH and adrenal medulla pro‐enkephalin‐derived peptides such as the 8.6 kDa synenkephalincontaining precursor and peptide B. Chromogranin A is itself selectively processed by IRCM‐SP1, and ACTH was shown to compete for such cleavage. These data suggest that chromogranins as a class of acidic proteins could participate in the tissue‐specific processing of pro‐hormones.
Regulatory role of the ATPase inhibitor protein on proton conduction by mitochondrial H+‐ATPase complex
Authors: Guerrieri Ferruccio , Scarfò Rosanna , Zanotti Franco , Che Yan Wu , Papa Sergio
Published: July 2002

This study shows that the natural inhibitor protein of mitochondrial H+‐ATPase complex (IF1) inhibits, in addition to the catalytic activity, the proton conductivity of the complex. The inhibition of ATPase activity by IF1 is less effective in the purified F1 than in submitochondrial particles where F1 is bound to F0. No inhibition of H+ conductivity by F0 is observed in F1‐depleted particles
The ‘molten globule’ state is involved in the translocation of proteins across membranes?
Authors: Bychkova Valentina E. , Pain Roger H. , Ptitsyn Oleg B.
Published: July 2002

Strong evidence exists that the translocation of proteins across a variety of membranes involves a non‐native or denatured conformational states. On the other hand a compact state having secondary but not rigid tertiary structure and called the ‘molten globule’ state has been identified as being stable under mild denaturing conditions. A similar state has been shown to accumulate on the folding pathway of globular proteins. These states are compact though sufficiently expanded to include water, and they are internally mobile. It is proposed that these molten globule states may be suitable candidates for protein translocation across biological membranes.
Renin inhibitors Improvements in the stability and biological activity of small peptides containing novel Leu‐Val replacements
Authors: Kleinert Hollis D. , Luly Jay R. , Marcotte Patrick A. , Perun Thomas J. , Plattner Jacob J. , Stein Herman
Published: July 2002

We have designed a novel class of potent (0.3–7 nM) renin inhibitors which contain a dihydroxyethylene replacement for what is formally the Leu1O‐Val11 amide bond. Good potency (0.6 nM), water solubility (> 10 mg/ml at 37°C), stability toward degradation by chymotrypsin (t

=82O min), and in vivo activity in a primate model (15% drop in mean arterial pressure in association with complete inhibition of plasma renin activity) are properties which have been incorporated into compound 10, an interesting new agent to be used in the study of hypertension.
Does the channel for nascent peptide exist inside the ribosome? Immune electron microscopy study
Authors: Ryabova L.A. , Selivanova O.M. , Baranov V.I. , Vasiliev V.D. , Spirin A.S.
Published: July 2002

MS2 phage RNA‐directed synthesis of an N‐terminal polypeptide of the phage coat protein on Escherichia coli 70 S ribosomes was initiated in a cell‐free system with the N‐dinitrophenyl derivative of methionyl‐tRNAMet
F and performed in the absence of tyrosine, lysine, cysteine and methionine. As a result, the translating ribosomes carried peptides up to 42 amino acid residues in length with the dinitrophenyl hapten at the N‐ends. Using the immune electron microscopy technique the positions of the nascent peptide N‐ends on the 70 S ribosomes have been visualized. It has been found that (i) the N‐ends of nascent peptides of these lengths are accessible to antibodies, (ii) the exit site of a nascent peptide is the pocket between the base of the central protuberance and the L1 ridge on the 50 S subunit, i.e. presumably its peptidyl transferase center, and (iii) the further pathway of a nascent peptide seems to proceed along the groove on the external surface of the 50 S subunit.
Characterisation of the reactivity of autoantibodies in primary biliary cirrhosis
Authors: Fussey Shelley P.M. , Bassendine Margaret F. , James Oliver F.W. , Yeaman Stephen J.
Published: July 2002

Autoantibodies in the sera of patients with primary biliary cirrhosis, shown previously to recognise the E2 polypeptide of the mammalian pyruvate dehydrogenase complex (PDC), have been demonstrated to react with the E2 component of PDC from bacteria (E. coli) and yeast (S. cerevisiae). Limited tryptic digestion, which cleaves E2 into well‐characterised domains, followed by Western blotting indicates that the main immunodominant region of PDC E2 lies within the lipoic acid‐containing domains of the polypeptide.
A 10 kDa polypeptide associated with the oxygen‐evolving complex of photosystem II has a putative C‐terminal non‐cleavable thylakoid transfer domain
Authors: Webber Andrew N. , Packman Leonard C. , Gray John C.
Published: July 2002

The N‐terminal amino acid sequence of the 10 kDa polypeptide associated with the oxygen‐evolving complex of wheat photosystem II has been determined and shown to be homologous to the amino acid sequence of the product of the ST‐LS1 gene from potato. The N‐terminal sequence of the mature protein indicates that the polypeptide is synthesized with a 39 amino acid N‐terminal presequence which is similar to chloroplast import sequences but which lacks a hydrophobic domain for transfer of the protein across the thylakoid membrane. The mature polypeptide has a C‐terminal hydrophobic region which shows homology to the hydrophobic thylakoid transfer domain of other lumenal proteins and this hydrophobic region of the 10 kDa polypeptide is suggested to facilitate transfer of the protein across the thylakoid membrane.
Extracellular Na+ removal enhances granule secretion in platelets 3‐evidence that Na+/H+ exchange is inhibitory to secretion induced by some agonists
Authors: Krishnamurthi Sushila , Morgan Winston A. , Kakkar Vijay V.
Published: July 2002

The effect of extracellular Na+ ([Na+]e) removal on agonist‐induced granule secretion in platelets in relation to [ph]i and [Ca2+]i changes was investigated. Substitution of [Na+]e with choline+ of K+ resulted in a significant enhancement of 5HT secretion induced by thrombin, collagen, U46619 and the protein kinase C activators, PMA and diC8. Increases in [Ca2+]i induced by thrombin and U46619 were slightly inhibited or unaffected in these buffers, but [pH]i increases induced by thrombin, U46619, PMA and diC8 were abolished and a drop in [pH]i (0.05–0.1 units below resting) was observed. Although preincubation with potassium acetate produced a big drop in [pH]i and greatly increased secretion with all the agonists, particularly in the absence of [Na+]e, clear evidence that [pH]i rises due to Na+/H+ exchange are inhibitory to secretion was obtained only with thrombin. Thus, (i) NH4Cl, which restored the increase in [pH]i in the absence of [Na+]e reduced the potentiated secretory response to thrombin, (ii) no increase in thrombin‐induced secretion was observed when Na+ was replaced with Li+, which allowed a normal increase in [pH]i and (iii) ethyl isopropyl amiloride (EIPA) abolished the [pH]i rise and potentiated thrombin‐induced secretion. With collagen and U46619, the results suggest that removal of [Na+]e per se rather than inhibition of Na+/H+ exchange results in enhanced secretion. It is concluded that [Na+]e per se and [pH]i elevations via Na+/H+ exchange both have important inhibitory roles in the control of platelet granule secretion.
Molecular cloning and sequence analysis of cDNA encoding rat adrenal cytochrome P‐45011β
Authors: Nonaka Yasuki , Matsukawa Naomichi , Morohashi Ken-ichirou , Omura Tsuneo , Ogihara Toshio , Teraoka Hiroshi , Okamoto Mitsuhiro
Published: July 2002

A cDNA clone encoding cytochrome P‐45011β of rat adrenal has been cloned and sequenced using a bovine P‐45011β cDNA insert (pcP‐450(11β)‐2; (1987) J. Biochem. 102, 559–568) as a probe. The nucleotide sequence contains an open reading frame sufficient to encode the entire amino acid sequence of a P‐45011β precursor protein consisting of 499 amino acids including an extension peptide of 24 amino acids at the NH2‐terminus. The cDNA contains 1247 nucleotides at the 3′‐noncoding region including 51 nucleotides of poly A, but lacks the 5′‐noncoding region. The deduced amino acid sequence shows 61% similarity to that of bovine P‐45011β. Putative binding sites for heme and steroid are highly conserved among steroidogenic P‐450s of known structure.
Human gelatinase/type IV procollagenase is a regular plasma component
Authors: Vartio Tapio , Baumann Marc
Published: July 2002

Gelatin zymograms revealed in human plasma a constant 66 kDa proteolytically active polypeptide. In most plasma samples other major proteolytic activities were seen at M
r92 000,130 000 and 225 000. All four proteases were Ca2+‐dependent metalloproteases and bound quantitatively to gelatin‐Sepharose. Immunoblotting results indicated that the 66 kDa protease was the human fibroblast gelatinase/type IV procollagenase and that the other three proteases were macrophage/granulocyte‐derived gelatinase components. The 66 kDa protease did not bind to conA‐ nor lentil lectin‐Sepharose allowing its separation from the 92, 130 and 225 kDa proteases. During the isolation procedure the plasma gelatinase/type IV procollagenase tended to form a proteolytically active spontaneous disulfide‐bonded dimer and a 62 kDa component that could also be obtained by digestion with trypsin. The same polypeptide changes occurred also in stored preparations of the corresponding protease isolated from fibroblast culture medium while the freshly purified protein contained only the 66 kDa proform.
Involvement of electrostatic phenomena in phospholamban‐induced stimulation of Ca uptake into cardiac sarcoplasmic reticulum
Authors: Chiesi Michele , Schwaller Roland
Published: July 2002

The activity of the Ca‐pumping ATPase of cardiac sarcoplasmic reticulum (SR) is controlled by the phosphorylation of the intrinsic regulatory protein phospholamban (PLB), which affects both the apparent K
m(Ca) and the V
max of the transport process. We have investigated the correlation between phosphorylation of PLB and the surface potential of the SR membrane. This latter influences the local concentration of relevant ionic species near biological membranes and thus modulates the activity of ion pumps and channels. The partitioning of the anionic probe 8‐anilino‐1‐naphthalenesulfonate (ANS−) into the SR membrane was found to be dependent on the phosphorylation level of PLB. Changes of the surface membrane potential up to 7 mV could be obtained by phosphorylation. The increase in the apparent affinity of the Ca pump for Ca2+ induced by PLB phosphorylation was clearly reduced at high ionic strength, i.e. under conditions known to reduce the surface membrane potential and all processes dependent on it. The results show that electrostatic phenomena can account, in good part, for the modulation of the Ca pump by PLB in cardiac SR.
Myristic acid is the NH2‐terminal blocking group of the 43‐kDa protein of Torpedo nicotinic post‐synaptic membranes
Authors: Carr Christina , Tyler Andrew N. , Cohen Jonathan B.
Published: July 2002

The NH2‐terminal blocking group of the 43‐kDa peripheral membrane protein (43‐kDa protein) of Torpedo post‐synaptic membranes has been identified as myristic acid. To identify that blocking group pure 43‐kDa protein was digested with trypsin and the blocked tryptic peptide was isolated by reverse phase HPLC. That peptide coeluted with and had the same amino acid composition as a synthetic peptide, myristoyl‐Gly‐Gln‐Asp‐Gln‐Thr‐Lys, the structure of the amino terminus predicted from the protein sequence deduced from a cDNA clone. The presence of myristate was confirmed by the precise molecular mass of the peptide, 886.5266, determined by fast atom bombardment mass spectroscopy.
Molecular cloning of a novel G protein‐coupled receptor that may belong to the neuropeptide receptor family
Authors: Eva Carola , Keinänen Kari , Monyer Hanna , Seeburg Peter , Sprengel Rolf
Published: July 2002

A novel cDNA encoding a putative G protein‐coupled receptor was isolated from a rat forebrain cDNA library by homology screening. Sequence comparison demonstrates that the encoded polypeptide containing seven transmembrane domains shows highest homology with tachykinin receptors, particularly in the transmembrane domains and the first intracellular loop. The mRNA for this new receptor seems specifically expressed in brain and is prominently localized in specific nuclei of the rat brain, including thalamus, cerebral cortex and hippocampus. We speculate that a neuropeptide may be the natural ligand of this novel G protein‐coupled receptor.