bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prenatal Stress, Glucocorticoids and the Programming of the Brain
Authors: Welberg L. A. M. , Seckl J. R. 
Published: August 2010

AbstractA large body of human epidemiological data, as well as experimental studies, suggest that environmental factors operating early in life potently affect developing systems, permanently altering structure and function throughout life. This process with its persistent organizational effects has been called ‘programming’. The brain is a key target for such effects. This review focuses on the effects of adverse early environments, notably exposure to stress or glucocorticoids, upon subsequent adult hypothalamus‐pituitary‐adrenal axis activity, behaviour and cognition. We discuss the effects observed, the proposed underlying molecular and cellular mechanisms and the consequences for pathophysiology. The data suggest that key targets for programming include glucocorticoid receptor gene expression and the corticotrophin‐releasing hormone system. Increasing evidence for analogous processes in humans is also reviewed. Early life programming of neuroendocrine systems and behaviour by stress and exogenous or endogenous glucocorticoids appears to be a fundamental process underpinning common disorders. Approaches to minimize or reverse the consequences of such early life events may have therapeutic importance.
Effects of Glucocorticoids on Adrenal Chromaffin Cells
Authors: Hodel A. 
Published: August 2010

AbstractThe mammalian adrenal gland consists of two anatomically distinct parts: an outer cortex that synthesizes steroids and a central medulla that contains catecholamine‐producing chromaffin cells. Although derived from different embryological origins, the two secretory tissues in the adult animal are functionally as well as structurally linked. Glucocorticoids, a class of steroid hormones produced by the cortex, exert a variety of effects on medullary chromaffin cells. They modulate the expression of specific genes via activation of glucocorticoid receptors that act as transcription factors and either up‐ or down‐regulate mRNA synthesis. The direct binding to and modulation of cation channels by glucocorticoids as well as the control of mRNA or protein stability are other proposed mechanisms of glucocorticoid action. The activity of phenylethanolamine N‐methyltransferase, the enzyme that converts noradrenaline into adrenaline, is stimulated by glucocorticoids, which causes the conversion of noradrenergic to adrenergic chromaffin cells. Other phenotypic manifestations of glucocorticoid action include the upregulation of catecholamine synthesis, storage, and secretion. Furthermore, glucocorticoids have been implicated in chromaffin cell differentiation. However, recent gene knockout experiments suggest that glucocorticoid signalling is required only for the acquisition of the adrenergic but not the noradrenergic phenotype.
FACTORS THAT INFLUENCE ACYL PROLINE CLEAVAGE BY SODIUM IN LIQUID AMMONIA
Authors: Marglin Arnold 
Published: August 2010

The reductive cleavage of aminoacyl proline bonds by sodium in liquid ammonia was compared by a simple chromatographic technic for various protected and unprotected analogs of the C‐terminal tetrapeptide of the insulin B‐chain, ‐Thr‐Pro‐Lys‐Ala‐OH. The literature suggests that the Thr‐Pro bond in this peptide is especially sensitive to Na‐NN 3, compared to various other acyl proline bonds. The present study shows that this is true regardless of whether the sidechains, the α‐amino, and the α‐carboxyl groups are protected or free when they are introduced into liquid ammonia; there is no difference in the amount of reductive Thr‐Pro cleavage despite the different numbers of protons released into liquid ammonia by the functional groups of the residues surrounding the Thr‐Pro bond. The C‐terminal tetrapeptide and its blocked derivatives, prepared by solid phase synthesis, were reduced by Na‐NH 3 to the same extent as similarly synthesized B‐chains and natural B‐chain. Thr‐Pro cleavage could be minimized by sharply limiting the amount of sodium and the time of exposure of the peptide to it. The results are therefore useful in planning synthetic approaches to the B‐chain.The Ser‐Pro bond shares the lability of the Thr‐Pro bond to Na‐NH 3 reduction, whereas the Val‐Pro bond is only half as labile.
STUDIES ON SILK FIBROIN. III. GEL FILTRATION STUDY OF FIBROINS
Authors: Pandit M. W. , Sagar A. J. , Rao M. S. Narasinga 
Published: August 2010

Silk fibroin samples obtained by extraction of silk fibre with boiling, Na2CO3 solution for different intervals of time were examined in 6M guanidine hydrochloride solution by gel filtration on agarose.
All the samples studied were heterogeneous. The weight‐average molecular weight of the samples estimated by gel filtration method was lower than that obtained by the Archibald ultracentrifuge method in 0.1 M KNO3 solution.
This discrepancy was observed to be due to the dissociating effect of 6 M guanidine hydrochloride.
Sodium dodecyl sulfate and β‐mercaptoethanol also caused dissociation.
The thermal degradation of silk fibroin in Na2CO3 solution followed a first order reaction kinetics.
Electrophoresis of the fibroins on polyacrylamide gels could not be performed since the protein remained at the top of the gel either due to precipitation of the protein or because of interaction with the gel. The experiments with buffer containing 6 M urea or 0.1% SDS also failed.
ADRENODOXIN REDUCTASE, THE FLAVOPROTEIN COMPONENT OF ADRENAL MITOCHONDRIAL STEROID HYDROXYLASES:
Authors: Wickramasinghe Rohan H. 
Published: August 2010

The activity of purified bovine adrenodoxin reductase was studied. The activity of the enzyme in reducing 2,6,‐dichlorophenolindophenol was maximal at about pH 6.5. The enzyme activity was affected by the ionic strength of the medium.Low concentrations of the cofactor FAD restored much of the activity of enzyme preparations which reduced dichlorophenolindophenol slowly. Higher concentrations of FAD inhibited both this reduction by adrenodoxin reductase and steroid hydroxylation by extracts of adrenal mitochondrial protein. These inhibitory effects may be the result of the reduction (with subsequent autoxidation under aerobic conditions) of FAD by NADPH in the presence of adrenodoxin reductase. The latter effect was demonstrated under anaerobic conditions.Some possible reasons for and implications of the observations are discussed.
STUDY BY PMR SPECTROSCOPY AND GEL CHROMATOGRAPHY OF THE UNFOLDING OF SUBSTITUTED KERATEINES IN 8 M UREA
Authors: Bradbury J. H. , Peters D. E. 
Published: August 2010

Various S‐substituted derivatives of the reduced low sulphur and high sulphur proteins from wool have been prepared in which the substituted group is hydrogen, carboxymethyl, carboxyethyl, methyl, carbamidomethyl, cyanoethyl and aminoethyl. The proton magnetic resonance (PMR) spectra and gel filtration chromatography of these proteins have been examined in 8 M urea solution as a function of pH in order to determine conditions under which the proteins occur as random coils in solution with no evidence for the occurrence of non‐covalent interactions.The PMR method described in an earlier paper (1) provides an easier and much more sensitive method for the observation of non‐covalent interactions in random coil proteins than does the measurement of elution volumes in gel chromatography. The results obtained by both methods are consistent and show that the widest range of pH for which unfolding occurs in 8 M urea is obtained with the S‐carboxymethyl, S‐carboxyethyl, S‐methyl and S‐carbamidomethyl derivatives.
PURIFICATION AND HETEROGENEITY OF HUMAN KININOGEN.
Authors: Hamberg Ulla , Elg Peter , Nissinen Erkki , Stelwagen Patrick 
Published: August 2010

Various methods of preparing human kininogen were investigated with an aim to limit the immunoreactive contaminant proteins to permit purification by immunosorption. A five‐step procedure is described giving 7.5% yield of highly purified kininogen (pharmacological purity 14–20) from pooled human plasma, and containing approximately 30% alpha‐2HS‐glycoprotein and 2.8% albumin. Alpha‐2HS could not be removed by polyacrylamide gel electrophoresis or isoelectric focusing in column.Analysis of heterogeneity of kininogen after chromatography on DEAE‐Sephadex using various linear gradients and gel filtration on Sephadex G‐100 suggested that a minor component may be an aggregate, not included in the yield. It remains uncertain whether this component derives from an occasionally observed high molecular form of active kininogen in the primary purification steps in the 7–12 S sieve fractions from Sephadex G‐200, and excluded from further purification by pooling.Purification with immunosorbents was investigated using batch operations with antibody specific polymers prepared with antisera insolubilized with ethylchloroformate. It was found that the adsorption‐desorption procedure was favourable for immunization purposes in producing highly specific immunologically pure kininogen. The kininogen obtained by this method or by the removal of contaminant alpha‐2HS and albumin with the corresponding antibody specific polymers gave similar heterogenous patterns by polyacrylamide gel electrophoresis, indicating a main band of kininogen and several faintly stained bands which responded only to anti‐kininogen. With 200 μg of the kininogen protein purified by immunosorption using monospecific antiserum the kininogen precipitation titre was 1:8 after 6–8 weeks in rabbits. With a polymer prepared with 4 ml anti‐kininogen serum (1:8) and incubated with 800 μg highly purified kininogen approximately half the protein was desorbed with 2 M and 3 M sodium iodide in the first adsorption‐desorption procedure.
STUDIES ON TRYPSIN INHIBITORS
Authors: Guggi Augusto , Tomatis Roberto , Benassi Carlo A. , Rocchi Raniero 
Published: August 2010

Synthesis is described of the protected undecapeptide tert‐butyloxycarbonylisoleucyl‐threonyltyrosylserylasparaginyl‐γ‐ tert‐butylglutamyl‐S‐acetamidomethylcysteinyl‐valylleucyl‐S‐acetamidomethylcysteinylserine hydrazide corresponding to positions 25–35 of the amino acid sequence of porcine pancreatic secretory trypsin inhibitor II (Kazal).The heptapeptide free base methyl asparaginyl‐γ‐tert‐butylglutamyl‐S‐aceta‐midomethylcysteinylvalylleucyl‐S‐acetamidomethylcysteinylserinate (sequence 29–35) was acylated, by the azide procedure, with the tetrapeptide tert‐butyloxycarbonyl‐isoleucylthreonyltyrosylserine hydrazide (sequence 25–28) and the resulting tert‐butyloxycarbonylundecapeptide methyl ester was transformed into the corresponding hydrazide by hydrazinolysis.The stereochemical homogeneity of the final product was assessed, after partial deprotection with aqueous 90% trifluoroacetic acid, by digestion with papain and aminopeptidase M followed by quantitative amino acid analysis.
PRIMARY STRUCTURE OF EQUINE GROWTH HORMONE
Authors: Zakin M. M. , Poskus E. , Langton A. A. , Ferrara P. , Santomé J. A. , Dellacha J. M. , Paladini A. C. 
Published: August 2010

The study of the structure of the peptides arising from native, oxidized, reduced and alkylated or citraconylated equine growth hormone on incubation with trypsin and chymotrypsin is reported.The data obtained, combined with results already published, support the assembly of a unique sequence of amino acids for the polypeptide chain of the protein.
THE SECONDARY STRUCTURE OF HISTONE IV AND ITS STABILITY
Authors: Pekary A. Eugene , Chan Sunney I. 
Published: August 2010

The secondary structure within histone IV and its fragments obtained by cyanogen bromide (CNBr) cleavage at Met 84 has been examined by circular dichroism and spectrophotometric pH titration measurements. These studies have confirmed the existence of stable secondary structure within the C‐terminal fragment of histone IV (C‐peptide) which can be perturbed only by 6 M urea at pH > 8 or 8M guanidine ˙ HCl. In contrast, the N‐terminal fragment (N‐peptide) appears to lack significant secondary structure at low ionic strengths but acquires approximately 15%β‐sheet conformation and 5%α‐helix upon aggregation at ionic strengths ≥ 0.4.The rates of nitration of the N‐ and C‐peptides by tetranitromethane (TNM) have also been measured as a function of ionic strengths. Under comparable conditions, the rate constant for nitration of the N‐peptide was found to be about six times greater than that for the C‐peptide, further evidence in support of the presence of stable secondary structure within the C‐terminal region of histone IV. After binding these histone IV fragments to DNA, however, the nitration reaction rate constants for the N‐ and C‐peptide in the bound form are found to be 2% and 27% of the corresponding free peptides. Reconstituted nucleohistone IV is about 10% as reactive to TNM as histone IV at comparable ionic strength.
SIZE AND SHAPE OF TWO INTESTINAL DIPEPTIDASES
Authors: Sjöström Hans , NoréN Ove 
Published: August 2010

Physicochemical parameters were determined on glycyl‐L‐leucine hydrolase (glycyl‐leucine dipeptidase, EC 3.4.13.2) and aminoacyl‐L‐proline hydrolase (proline dipeptidase, EC 3.4.13.9), purified from pig small intestine. The native molecular weights were found to be 115,000 and 113,000, respectively, as determined by a sedimentation equilibrium technique. Under denaturing conditions the molecular weights were found to be 51,000 and 63,200, respectivemy, using the same technique. It is concluded that each dipeptidase is composed of two subunits of equal molecular weight.The two dipeptidases have the same Stokes radius, 4.2 nm, analysed by gel chromatography. The sedimentation coefficients were found to be 5.8 S and 6.5 S and the intrinsic viscosities 5.4 ml/g and 5.8 ml/g, respectively. For both dipeptidases the measured physicochemical parameters are in accordance with the model of a prolate ellipsoid of revolution, having an axial ratio of about 5.
REMOVAL OF t‐BUTYL AND t‐BUTOXYCARBONYL PROTECTING GROUPS WITH TRIFLUOROACETIC ACID
Authors: Lundt Behrend F. , Johansen Nils L. , Vølund Aage , Markussen Jan 
Published: August 2010

The trifluoroacetic acid‐mediated removal of t‐butyl groups in protected amino acids leads to the formation of t‐butyl trifluoroacetate. This t‐butyl ester alkylates in trifluoroacetic acid methionine and tryptophan. The t‐butyl trifluoroacetate ester can be destroyed by scavengers commonly employed for t‐butyl cations, and the reaction rates of the scavengers with the ester are used in the evaluation of scavengers. Scavengers of sulphide structure react with t‐butyl trifluoroacetate to form sulphonium compounds, which possess alkylating properties.In the presence of a scavenger during acidolysis, the trifluoroacetic acid and the scavenger will compete in reacting with the t‐butyl cations. Kinetic studies show comparable reaction rates with thiophenol as scavenger. The usefulness of adding scavengers to trifluoroacetic acid in deblocking reactions is due to the removal of t‐butyl trifluoroacetate in addition to the removal of t‐butyl cations.Isobutene reacts with trifluoroacetic acid and yields t‐butyl trifluoroacetate. The reaction reaches an equilibrium displaced in favour of the ester at room temperature. Hence no isobutene can be expected to escape during a deblocking reaction in trifluoroacetic acid.
PURIFICATION AND PROPERTIES OF NON‐PRECIPITATING ANTIBODIES TO COBROTOXIN*
Authors: Yang C.C. , Chang C.C. , Lin M.F. , Lee H.Y. , Chuang L.Y. 
Published: August 2010

The heterogeneity of precipitating and non‐precipitating antibodies to cobrotoxin was demonstrated by their elution pattern on cobrotoxin‐Sepharose and chromatography on DEAE‐cellulose column.Gel filtration patterns on a Sepharose 6B column revealed that the soluble complexes formed from non‐precipitating antibody and HNB‐cobrotoxin at a different molar ratio all emerged in the void volume, indicating that the molecular weight of the soluble complex is around 4,000,000 or larger. Unreacted free non‐precipitating antibody coincided with the peak of IgG and was proved to be free from HNB‐cobrotoxin. The molar ratio of antibody to antigen for the soluble complex was found to be 0.79 to 0.97 indicating that 1.58–1.94 molecules of non‐precipitating antibody are bound to HNB‐cobrotoxin instead of three molecules as in the case of precipitating antibody.
RABBIT LUTROPIN: PREPARATION, CHARACTERIZATION OF THE HORMONE, ITS SUBUNITS AND RADIOIMMUNOASSAY
Authors: WARD DARRELL N. , DESJARDINS CLAUDE , MOORE WILLIAM T. , NAHM HYUN S. 
Published: August 2010

The purification of rabbit lutropin is described. A product with a potency of 1.53 × NIH‐LH‐Sl was obtained as assayed by the ovarian ascorbic acid depletion assay. In a homologous radioimmunoassay, which is described, rabbit lutropin has a potency 4.83 × NIH‐LH‐Sl. In a radioligand assay, utilizing labeled ovine lutropin as the trace, the relative potency was 0.47 × NIH‐LH‐Sl measured by 50% inhibition comparison since rabbit lutropin response in this system did not parallel ovine lutropin.A counter‐current distribution procedure for separation of rabbit lutropin subunits is described. Amino acid composition of the isolated subunits and intact rabbit lutropin was determined. The carbohydrate composition of the latter is presented; only amino sugar determinations are available for the subunits. The NH2‐terminal amino acids are phenylalanine (alpha subunit) and alanine (beta subunit). Preliminary data on COOH‐terminal amino acids are provided.
Conformational study of the basic proline‐rich polypeptides from human parotid saliva
Authors: Shibata S. , Asakura J. , Isemura T. , Isemura S. , Saitoh E. , Sanada K. 
Published: August 2010

The conformational study of two basic proline‐rich polypeptides from human parotid saliva, P—D and P—E of known primary structures, was performed by CD and 1H—n.m.r. spectra measurements. These polypeptides contain consecutive sequences of five prolyl residues in their amino acid sequences. The troughs in CD spectra of P—D and P—E were found at 202 and 201 nm, respectively. These wavelengths were different from the value of 206 nm of poly‐l‐proline form II conformation. In spite of this, the existence of poly‐l‐proline form II conformation was suggested in the structure of P—D, because the trough for a fragmental peptide of P—D containing five consecutive prolyl residues was found at 204 nm.No remarkable change was detected in CD and 1H—n.m.r. spectra of P—D and P—E in the range of pH 3.0–11.0. The result suggests that no folding of polypeptide which might be affected by ionic interaction exists in its structure.
Systematic study of substance P analogs
Authors: WANG JIAN‐XIN , DIPASQUALEI ANGELA J. , BRAY ANDREW M. , MAEJI N. JOE , SPELLMEYER DAVID C. , GEYSEN H.MARIO 
Published: August 2010

Recent developments in multiple peptide synthesis have made it feasible to synthesize and screen large numbers of peptide analogs simultaneously. We report here a model study of large scale screening of stereoisomers of substance P with systematic d‐aminO acid replacements. Such studies are useful in exploring conformational requirements of peptide‐receptor interaction and to provide empirical information for peptide drug design.512 stereoisomers of SP were prepared by the multipin peptide synthesis method. Receptor binding affinities of these analogs were estimated by an iterative competition assay. Results obtained form a comprehensive database on the stereochemical requirement of SP binding to central NK1 receptor. Data from analogs with single d‐amino acid replacement are consistent with those previously reported showing that SP binding is highly sensitive to the chirality change of the C‐terminal residues (Gln6‐Leu10), but less sensitive to the chirality change of the N‐terminal residues (Arg1‐Gln5). A qualitative analysis of the database by comparison of series of peptide pairs revealed a repeated pattern of affinity change with d‐amino acid replacement, suggesting a largely additive binding activity of SP from each residue. On the other hand, possible intramolecular interactions between some N‐terminal and C‐terminal residues to form an optimal binding conformation were also found.A set of 189 peptides with IC50 values less than 5 μM was subjected to an empirical QSAR analysis using a linear additive model. The relative contribution coefficients obtained agreed with the observation that the predominant contribution comes from the C‐terminal residues, suggesting considerable independency of each residue on binding to NK1 receptors. However, the possibility of interactions among residues in forming an optimal binding conformation can not be excluded as implied by a marginal fitting of the data to this model (R2= 0.61). The poor prediction of binding activity by the model used emphasizes the importance of systematic, empirical approaches in discovery and designing new peptide analogs, which is now achievable using multipeptide synthesis techniques.
Migration of monocytes in the presence of elastolytic fragments of elastin and in synthetic derivates Structure‐activity relationships
Authors: BISACCIA F. , MORELLI M.A. CASTIGLIONE , BIASI M. DE , TRANIELLO S. , SPISANI S. , TAMBURRO A.M. 
Published: August 2010

YGVG and GLVPG, two new chemokinetic peptides, were identified in elastolytic digests of elastin, besides the known chemoattractant hexapeptide VGVAPG. In order to identify possible sequences responsible for the chemotactic and chemokinetic activities and to obtain structure‐activity relationships we synthesized some analogues of these peptides: FGVG (an analogue of YGVG), GVAPG and VGAPG (derived from the hexapeptide by deletion of Val1 or Val3). FGVG has a higher chemotactic activity than YGVG (chemotactic indices of 0.62 and 0.49, respectively, at 10−11 M) and is both chemotactic and chemokinetic.Checkerboard analysis demonstrated that both peptides derived from the hexapeptide present, in addition to the chemotactic activity, a cheniokinetic activity. The chemotactic index of GVAPG is 0.66 at 10−10M, while for VGAPG it is 0.86 at 10−9 M.These results indicate that the deletion of the N‐terminal residue of the elastin chemotactic peptides, VGVAPG and GFGVG, gives rise to chemokinetic activity.CD and NMR studies showed that all peptides are largely unordered in aqueous solution. © Munksgaard 1994.
Versuche mit Rauhfuttermitteln in Automatenrationen für Schweine
Authors: Thomke Sigvard 
Published: August 2010

ZusammenfassungEs wird über die Versuchsergebnisse von drei Versuchen mit je vier Gruppen zu je vier Tieren berichtet, welche im Automatenfutter 10 % Heuhäcksel, 10 % Haferspreu bzw. 6 % Strohhäcksel als “Verdünnungsmittel” in den drei Versuchen erhielten. Es war be‐absichtigt, durch diese Maßnahme die Einwirkung der groben Futtermittel auf das Wachstum und auf die Rückenspeckdicke sowie auf die Futterverwertung zu kontrol‐lieren. Die Versuche ergaben, daß mit Hilfe gröberer Futterrationen bei der Automa‐tenfütterung die Möglichkeit gegeben ist, auf Kosten der Tageszunahmen und der Futterverwertung das Muskel‐Fettverhältnis günstig zu beeinflussen. Wachstumsbe‐grenzende Ursachen werden diskutiert, welche auch den Fettansatz zu beeinflussen scheinen.Eine statistische Auswertung des Materials erbrachte folgendes: Die auf den gleichen Schlachtverlust korrigierten durchschnittlichen Tageszunahmen werden durch die Er‐höhung der “Sperrigkeit” des Futters signifikant herabgesetzt, während für die wie oben korrigierte Futterverwertung sowie insbesondere für die Rückenspeckdicke starke Tendenzen eines herabsetzenden Einflusses zu verzeichnen sind.In der Diskussion wird die Möglichkeit erörtert, an Stelle der pro Wachstumsein‐heit geltenden Verwertungsausdrucke solche zu berechnen, welche dem variierenden Energiegehalt bei unterschiedlichem Muskel‐Fettverhältnis Rcchnung tragen. Es wird an Hand der Erfahrungen im vorliegenden Versuch darauf hingewiesen, daß man bei der Erzeugung vollwertiger Schlachtkörper die Aufmerksamkeit nicht nur auf die Fütterungsverhältnisse und auf das Futter zu richten hat, sondern auch auf den An‐lagentyp der Schweine, welchem etwa die gleiche Bedeutung wie dem Fütterungsmilieu zukommt. Durch eine geeignete Kombination der Zuchtwahl und der Fütterung er‐scheint es Verf. möglich, die Automatenfütterung weiterhin auszubauen.