bluuebunny/crossref_metadata_2025_split huggingface dataset:
The analysis of maxillary sinus aeration according to aging process; volume assessment by 3‐dimensional reconstruction by high‐resolutional CT scanning
Authors: Jun Beom‐Cho , Song Sun‐Wha , Park Chan‐Soon , Lee Dong‐Hee , Cho Kwang‐Jae , Cho Jin‐Hee 
Published: March 2005

OBJECTIVETo evaluate change of the maxillary sinus volume according to patient age and gender by using a 3‐dimensional (3‐D) reconstruction of computed tomography images.STUDY DESIGN AND SETTINGOne hundred seventy‐three people (totaling 238 maxillary sinuses) who had undergone paranasal sinus CT scan between December 2000 and November 2003 and had no evidence of inflammation or hypoplasia in the CT finding and had no specific history of paranasal sinus surgery or maxillofacial trauma were retrospectively analyzed. The 3‐D reconstruction images were obtained by using a surface‐rendering technique (Vworks; CybeMed, Seoul, Korea) on a personal computer. The mean volume of maxillary sinus was evaluated according to patient chronologic age and gender. The ratio of the maximum horizontal and half‐horizontal extension for the estimation of the morphological change of maxillary sinus and the degree of descent of the sinus below the nasal floor were evaluated in the 3‐D image.RESULTSThe development of the maxillary sinus continued until the 3rd decade in males and until the 2nd decade in females. The mean maxillary sinus volume in early adults was 24,043 mm3 (males) and 15,859.5 mm3 (females). There was a significance difference in the sinus volume (P < 0.05) according to gender, and there was a significant difference in the maxillary sinus volume according to age before it reached maximum. After its maximum growth period, however, there was no significant difference in the volume change of maxillary sinus and the descent below the nasal floor between two adjacent groups.CONCLUSIONSThe growth of the maxillary sinus continues until the 3rd decade in males and the 2nd decade in females. Therefore, a maxillary sinus operation affecting the bony structures before these ages might affect the development of the sinus and needs to be performed carefully
Bryophyte colonisation in experimental microcosms: the role of nutrients, defoliation and vascular vegetation
Authors: Aude E. , Ejrnæs R. 
Published: March 2005

A three‐year multi‐factorial microcosm experiment simulating fertilisation, defoliation and the composition of vascular vegetation in a dry grassland succession was used to test four hypotheses concerning the establishment and survival of bryophytes in grassland vegetation. H1: bryophyte cover may be used to predict bryophyte species richness. H2: bryophyte richness is suppressed at high nutrient levels and promoted by defoliation of vascular plants. H3: species richness of bryophytes is influenced by the species composition of the vascular vegetation. H4: bryophyte species richness is negatively correlated with vascular plant biomass.The relationship between bryophyte richness and bryophyte cover was found to follow the classical species‐area richness curve. Bryophyte species richness responded positively to defoliation and negatively to fertilisation. The species composition of vascular vegetation had no significant effect on bryophyte richness. Bryophyte species richness was lower at high vascular plant biomass and vascular plant dry weight above 400 g m−2 appeared fatal to bryophytes. At high nutrient levels, defoliation increased bryophyte richness, but defoliation did not fully compensate for the negative effect of fertilisation. The study reinforces the concern for short lived shuttle bryophytes in the agricultural landscape.
Influence of Salts on RNA Synthesis by DNA‐Dependent RNA‐Polymerase from Escherichia coli
Authors: Fuchs E. , Millette R. L. , Zillig W. , Walter G. 
Published: March 2005

The effect of salt concentration on RNA synthesis by DNA‐dependent RNA‐polymerase from Escherichia coli has been investigated. For a double stranded template the following influences are observed: (1) Free enzyme and enzyme bound to DNA, but not synthesizing RNA, are inhibited above an ionic strength of about 0.15. (2) The rate of RNA‐synthesis, by those enzyme molecules which have started RNA chains, is stimulated by increasing the salt concentration up to an optimum. Magnesium salts cause a larger stimulation than monovalent cations. However, the optimal effect always occurs at an ionic strength of about 0.36. (3) This stimulatory effect is distinguished from the cofactor function which requires only low concentrations of divalent cations (Mg2+, Co2+, Mn2+). (4) RNA synthesis stops at low ionic strength (<0.2) due to a first order inactivation of the synthesizing enzyme. At high ionic strength synthesis continues over many hours at a slowly decreasing rate. Raising the ionic strength after RNA synthesis has stopped at low ionic strength causes an immediate resumption of synthesis. Mg2+ and spermidine are most effective in this action. However, Co2+ and Mn2+ are unable to reactivate the enzyme once it has stopped.With single stranded DNA as template neither a first order inactivation of synthesizing enzyme at low ionic strength nor a stimulation of RNA synthesis by monovalent salts is observed. The effect of divalent cations on enzyme activity can be due to their cofactor function.
Synchronized Yeast Cells
Authors: Eckstein H. , Paduch V. , Hilz H. 
Published: March 2005

Homogenates and extracts of yeast cells (Saccharomyces cerevisiae) exhibit DNA polymeras activity as revealed by incorporation of labeled dATP into DNAase‐sensitive, RNAase‐resistent acid‐insoluble material, the incorporation being dependent on the presence of all four deoxynucleotide triphosphates and primer DNA.Extracts from synchronized yeast cells exhibit DNA polymerase activity in an oscillating manner during the cell cycle, maximum activity being found just before the onset of DNA replication. Degradation and resynthsis, or transformation to an inactive “zymogen” are discussed as possible mechanisms of the oscillating behavior of polymerase activity.X‐irradiation brings about a dissociation of DNA replication and oscillating appearance of the polymerase. Whereas DNA replication is temporarily delayed, the rhythmic appearance of the enzyme is unaffected. However, the height of the activity maxima remains unchanged until DNA is reduplicated again. The observations are discussed with regard to the apparent intactness of the DNA template functions and to the persistence of the sequential transcription of genes in the proliferation‐inhibited irradiated yeast cells.
The Role of Free Amino Groups in the Blood Group Activity of M and N Mucoids
Authors: Lisowska E. , Morawiecki A. 
Published: March 2005

The M and N blood group substances were treated with different amino‐group reagents, such as: acetic‐, succinic‐, and phthalic‐anhydrides, benzyloxycarbonylchloride, dinitrofluorobenzene, nitrous acid and O‐methyl‐isourea.
It was shown that htese reagents blocked or destroyed 2–4 free amino groups (mainly lysine ɛ‐NH2 groups) per one subunit of M or N blood group substance of mol. wt. 30,000. No other effects were found under the conditions used.
The blocking or decomposition of amino groups, connected with the loss of their positive charge, lowered the blood activity of M and N mucoids and did not decrease their activity towards phytoagglutinins and the inhibitory activity of viral hemagglutination. The guanidylation of amino groups did not destroy the blood group activity of M and N mucoids.
On the Interaction of Bovine Cobalt Carbonic Anhydrase with Sulfonamides
Authors: Lindskog S. , Thorslund A. 
Published: March 2005

The pH‐dependence of the inhibition of cobalt carbonic anhydrase by three different sulfonamides has been measured employing p‐nitrophenyl acetate as substrate. The binding of these inhibitors is linked to two ionizing groups. One of these seems to be identical to the group in the enzyme previously shown to control the catalytic activity. The pK of the second group is characteristic for the individual inhibitor and agrees with pK‐values obtained by titration of the sulfonamides.
Sulfanilamide and the anionic inhibitor, NO3−, appear to compete for one binding site on the enzyme.
When the sulfanilamide inhibition of the CO2‐hydration activity was studied by the stopped‐flow method, some anomalous behavior was observed. From the initial part of the reactions, apparent noncompetitive inhibition was obtained. The rates increased over a short time period, however, to give essentially a competitive pattern. The results can be explained by assuming that the substrate and the inhibitor are competitive, but that equilibration is not immediately achieved due to a comparatively slow rate of dissociation of the inhibitor from the enzyme.
The apparent second order rate constant for the formation of the enzyme‐sulfanilamide complex has been estimated as 7 × 104 M−1 sec−1 at pH 7.9 and 25°. In the presence of CO2, the reaction is slower to an extent which is compatible with a competition for a common binding site.
A simple, though not unique, mechanism for the sulfonamide inhibition of bovine cobalt carbonic anhydrase, accounting for both rate and equilibrium data, implies the formation of the enzyme‐inhibitor complex through a direct reaction of the ionized sulfonamide with the inactive, acid form of the enzyme.
Organization of Fatty Acid Oxidation in Rat Kidney Mitochondria
Authors: ROSSI C. R. , ALEXANDRE A. , SARTORELLI L. 
Published: March 2005

Long‐chain fatty acids are oxidized by intact rat kidney mitochondria under experimental conditions which permit the location of three long‐chain acyl‐CoA synthesizing systems.Oleate oxidation which is 2,4‐dinitrophenol‐insensitive and which is inhibited by arsenate and excess phosphate, is probably energized by GTP. The isolation of the GTP‐dependent acyl‐CoA synthetase from sonicated kidney mitochondria supports this hypothesis.Oleate oxidation which is insensitive to phosphate and arsenate and requires oligomycin, utilizes “endogenous” ATP and is not linked to added carnitine.The third oleate oxidation system requires added ATP, CoA and phosphate and depends on a carnitine‐linked transport mechanism.
Zur Bildung von Chinolinalkaloiden in Pflanzen
Authors: COBET M. , LUCKNER M. 
Published: March 2005

Last year it was shown that the quinoline nucleus of the furoquinolines dictamnine and skimmianine is biogenetically derived from anthranilic acid and acetate. The labelling pattern indicates that the C‐atoms 4,12,5–8 and 9 and the nitrogen arise from anthranilic acid whilst C‐10 and C‐11 come from the carboxylic and the methyl group of acetic acid, respectively. Until now no intermediates of this biosynthetic pathway were known.To proof the activity of 2‐amino‐benzoylacetic acid and its amide 2,4‐dihydroxyquinoline (both compounds are in a pH dependent equilibrium) as precursors of the furoquinolines we have synthesised 2,4‐dihydroxy‐3‐14C‐quinoline. After feeding this compound to plants of Ruta graveolens L. Kokusaginine (4,6,7‐trimethoxy‐furoquinoline) was isolated. The high incorporation rate which was found leads to the conclusion that 2,4‐dihydroxyquinoline (and 2‐amino‐benzoylacetic acid) are direct precursors of this alkaloid.
Metal Content of Cysteamine Oxygenase
Authors: CAVALLINI D. , DUPRÉ S. , SCANDURRA R. , GRAZIANI M. T. , COTTA‐RAMUSINO F. 
Published: March 2005

Cysteamine oxygenase has been analysed for the presence of metals, by spectrographic analysis, and X‐ray fluorescence. Iron, copper, and zinc have been found in the enzyme in the quantity accounting for 1 atom of each metal per molecule of enzyme.Passage of the enzyme through a chelating resin column did not appreciable change the specific activity but the metal content was decreased below the value of one atom per molecule of enzyme. Possible explanations for this finding are suggested.The effect of several chelating agents on enzymic activity has been studied. All the chelating agents assayed were found inhibitory when tested in suitable concentration. The highest inhibition was observed with 8‐hydroxyquinoline, diethyldithiocarbamate and o‐phenanthroline. KCN also was a good inhibitor.It is concluded that cysteamine oxygenase is a metal‐containing enzyme and that the metals should play a functional role.
Myo‐Inositol, a Cofactor in the Biosynthesis of Stachyose
Authors: TANNER W. , KANDLER O. 
Published: March 2005

In extracts from Phaseolvs vulgaris seeds an enzyme has been found which transfers the galactosyl moiety of galactinol to raffinose giving rise to stachyose and myo‐inositol.
Two tests to measure the enzyme activity are described.
The reaction is reversible. An equilibrium constant of approximately 4 has been determined for . The enzyme catalyzes exchange reactions between galactinol and myo‐[14C]inositol and between stachyose and [14C]raffinose. Specifically labeled galactinol and stachyose can be prepared in this way.
The Km values for galactinol and for the two best galactosyl acceptors, raffinose and melibiose, have been measured.
Besides the galactinol: raffinose‐6‐galactosyl transferase the extract of the seeds also contains an α‐galactosidase, which separates from the transferase during the purification. The transferase is strongly inhibited by p‐chloromercuribenzoate.
Ripening seeds contain an enzyme which catalyzes the reaction UDP‐galactose + myoinositol → galactinol + UDP. However, no direct transfer of galactose from UDP‐galactose to raffinose has been observed.
The physiological importance of the results is discussed.
Isolement, purification et quelques caractéristiques physicochimiques de deux β‐hexosidases du suc digestif d'Helix pomatia
Authors: GOT R. , MARNAY A. 
Published: March 2005

Two enzymes, G1 et G2, that hydrolyse o‐nitrophenyl‐β‐d‐galactopyranoside (ONPG), were isolated from the digestive juice of the snail Helix pomatia. Preparation involved precipitation with 30 vol.‐% acetone at pH 5.4 and −12°, filtration on Sephadex G‐200, precipitation with 2.8 M ammonium sulfate, chromatography on CM‐cellulose for G1 and on DEAE‐sephadex for G2; yield is approximately 7% for G1 and 25% for G2 from total activity.Pure enzymes were free from β‐glucuronidase and N‐acetyl‐glucosaminidase activities. Their homogeneity was established by criteria such as ultracentrifugation, immunoelectrophoresis and electrophoresis on cellulose acetate and in polyacrylamide or starch gel.Enzymes had a carbohydrate content of about 15‐16%, with galactose, mannose, glucose, fucose and glucosamine, but without sialic acid. Isoelectric points and electrophoretic mobilities of the two enzymes were also similar, but migration on starch gel and sedimentation coefficients (respectively 6.4 S and 10.4 S) were different. They had no immunological identity.The pH optima, in constant ionic strength 0.1 M sodium phosphate‐citric acid buffers, for hydrolysis of ONPG and lactose were respectively 5.4 for G1 and 5.2 for G2. Both enzymes attacked cellobiose, p‐nitrophenyl‐β‐d‐glucopyranoside and p‐nitrophenyl‐β‐d‐fucoside at the same pH as lactose or ONPG. Michaelis constants were determined by the method of Eadie. Values were lower for G2 than for G1.Evidences were produced that β‐galactosidase and β‐glucosidase activities reside in a single protein.
The Fractionation of the Histones of Group F2(b) from Calf Thymus
Authors: JOHNS E. W. 
Published: March 2005

The histones of group F2(b) have been fractionated by acetone precipitation and by column chromatography on carboxymethylcellulose at pH 9.The acetone precipitation method enables F2(b), prepared on a large scale by extraction methods, to be further purified in bulk, the resulting product having 84% N‐terminal proline.The column chromatography on carboxymethylcellulose at pH 9 has given 5 main fractions, two of which contain over 25% acidic amino acids (or their amides) and over 24% basic amino acids.
Structure sous‐unitaire de la thyroglobuline de mouton
Authors: LISSITZKY S. , ROLLAND M. , REYNAUD J. , SAVARY J. , LASRY S. 
Published: March 2005

Full reduction of the disulfide bridges of pure 19 S sheep thyroglobulin has been obtained by 2‐mercaptoethanol in 0.1 M Tris‐acetate pH 8.6 containing 8 M urea followed by alkylation (iodoacetate or iodoacetamide) of the thiol groups formed.
The S‐carboxymethylderivative is soluble only in the presence of concentrated urea or guanidine hydrochloride. Dissolved in the presence of 5 M or 6 M guanidine at pH 7.0 or 8.6 it sediments in the ultracentrifuge as a single homogeneous boundary.
In 5 M or 6 M guanidine at 20° and 25° the sedimentation constants extrapolated to zero concentration are: s°20, guan 6 M= 1.2 S; s°25, guan 5 M= 2.0 S. The values for the diffusion constant and for the intrinsic viscosity are: D°25, guan 5 M= 3.4; 100 [η]20, guan 6 M= 85; 100 [η]25, guan 5 M= 78.
Using these values, 0.705 for v and the values of s/D determined by equilibrium or approach‐to‐equilibrium sedimentation, the following molecular weight have been calculated: M1= 80 × 103 or 85 × 103 (equilibrium sedimentation), M2= 81 × 103 (approach‐to‐equilibrium in 0.017 M SDS at pH 8.6), M3= 70 × 103 (Svedberg equation). The molecular weight computed from the values of s and [η] in 5M and 6M guanidine were 160 × 103 and 114 × 103 respectively.
By gel filtration on Sephadex G‐200 in 0.1 M Tris‐acetate pH 8.6 containing 0.017 M sodium dodecylsulphate, the S‐carboxymethyl derivative of thyroglobulin is more retarded than γ‐globulin 7 S and serumalbumin. After correction for protein‐bound sodium dodecylsulphate the apparent molecular weight calculated for S‐carboxymethyl thyroglobulin by gel filtration agrees fairly well with the molecular weight (80 × 103) computed from the hydrodynamic properties. A similar value has been obtained by gel filtration on Sephadex G‐200 in Tris‐acetate 0.1 M pH 8.6 containing 5 M guanidine.
The discrepancy between the values of the molecular weight computed from the measurements of s and [η] on the one hand and by the measurement of s/D or s and D on the other hand is discussed in relation to data in the literature.
It is concluded that the 12 S subunit of thyroglobulin is most probably constituted by two different peptide chains (A = B = 80 × 103) in a proportion which remains to be determined.
Erreurs dans l'incorporation de certains amino‐acides après bromuration des RNA de transfert de levure
Authors: BAKES J. , EHRESMANN C. , BEFORT N. , WEIL J. H. , EBEL J. P. 
Published: March 2005

Some amino acids, such as isoleucine, valine, glutamic acid and lysine, which normally are not transferred from the corresponding aminoacyl‐tRNA's into polypeptides in the presence of poly U, are transferred when they are carried by brominated tRNA's. These errors are also observed in the presence of natural messenger RNA's: In a non‐preincubated cell‐free system which has been saturated with normal isoleucyl‐tRNA, the addition of bromiated isoleucyl‐tRNA produces an extra incorporation of isoleucine, whereas the addition of normal isoleucyl‐tRNA does not cause any further incorporation of isoleucine. These experiments suggests that the brominated isoleucyl‐tRNA molecules can recognize other triplets than those which normally code for the aminoacid isoleucine.In a non‐preincubated cell‐free system, in the presence of natural messenger RNA, there is a competition between normal phenylalanyl‐tRNA and brominated isoleucyl‐tRNA, and this suggests that the brominated isoleucyl‐tRNA molecules are able to recognize the UUU or UUC triplets. In the formation of the complex aminoacyl‐tRNA‐ribosomes‐poly U, the incorporation of brominated isoleucyl‐tRNA in the complex is greater than that of normal isoleucyl‐tRNA, and this is also in favor of the recognition of the UUU code words by brominated isoleucyl‐tRNA.
Myeloperoxidase of Human Leukaemic Leucocytes
Authors: ZGLICZYŃSKI J. M. , STELMASZYŃSKA T. , OSTROWSKI W. , NASKALSKI J. , SZNAJD J. 
Published: March 2005

Myeloperoxidase was isolated from leucocytes obtained from the blood of patients suffering from chronic granulocytic leukaemia. The enzyme was purified 850 fold and was homogeneous in ultracentrifuge and free boundary electrophoresis. The molecular weight of the enzyme was found to be about 160,000.The enzyme forms a spectrally characteristic complex with hydrogen peroxide with absorption maximum at 458 mμ. The spectrum of the native enzyme has absorption maxima at 430 and 570 mμ. The reduced enzyme is characterized by a spectrum with absorption maxima at 472 and 637 mμ.The investigated myeloperoxidase catalysed oxidation of amino acids by hydrogen peroxide. Products of the oxidation of amino acids were ammonia, carbon dioxide, and an aldehyde corresponding to the oxidized amino acid. The observed reaction of deamination and decarboxylation is activated by chloride ions. In the presence of the chloride ions the optimum of the reaction is shifted toward the higher pH values.The velocity of the reaction was found to be dependent on the concentration of the amino acid studied. Km values for various amino acids increased in the range 3.4 × 10−4 to 10−3 M in proportion to rising hydrophobic properties of the substrates. Taurine was found to be a competitive inhibitor in the examined reaction, and Ki values were in the range of 2 to 3 × 10−4 M, for different amino acids.
Energy Requirements in the Incorporation of Choline by Isolated Rat Liver Mitochondria
Authors: BYGRAVE F. L. , KAISER W. 
Published: March 2005

Optimal concentrations of ATP, CTP and ADP for the incorporation of 14C‐labelled choline into phospholipid by isolated rat liver mitochondria were 0.7 mM, 0.25 mM and 1.0 mM respectively. Higher concentrations markedly depressed the incorporation. Substitution of CTP for other nucleotide triphosphates led to lower rates of incorporation.Inhibitors of electron transport and of oxidative phosphorylation inhibited the respiration‐supported but not the ATP‐supported incorporation of choline. It is concluded that high energy intermediates of oxidative phosphorylation are not obligatory for the incorporation process.
Incorporation of Glucose into an Insoluble Polyglycoside during Oscillatory Controlled Glycolysis in Yeast Cells
Authors: Betz A. , Hinrichs R. 
Published: March 2005

In the first few minutes of oscillatory controlled glycolysis yeast cells convert 50% of all glucose taken up into ethanol and glycerol, and incorporate 80–90% of the rest into some in‐soluble polyglycoside.Glucose uptake in glycolysing yeast cells is a pulsatory process which is in phase with fruc‐tose‐1,6‐diphosphate synthesis. The concentration of UDPG, an intermediate in polyglucoside synthesis, is oscillating in phase with glucose‐6‐phosphate.The cells use 80–90% of all ATP synthesized in glycolysis for uptake and storage of glucose.