bluuebunny/crossref_metadata_2025 huggingface dataset:
Platelet serotonin concentrations in PKU patients under dietary control and tetrahydrobiopterin treatment
Authors: Ormazabal A. , Vilaseca M. A. , Pérez‐Dueñas B. , Lambruschini N. , Gómez L. , Campistol J. , Artuch R.
Published: January 2006

Tetrahydrobiopterin (BH4) supplementation has been applied in PKU treatment, resulting in successful control of blood phenylalanine (Phe) concentrations. We evaluated serotonin status in PKU patients under classical dietary treatment (n = 40) and in a group of 11 PKU patients under BH4 treatment, both during a 6‐month period. Platelet serotonin values were significantly lower in PKU patients under dietary treatment when compared with controls. A negative correlation was observed between plasma Phe and platelet serotonin concentrations (r = −0.367, p = 0.017) in PKU patients. Platelet serotonin concentration increased significantly after both 1 and 6 months of BH4 therapy when compared with baseline conditions (Wilcoxon test: p = 0.013 and p = 0.021, respectively), while no differences were observed when comparing plasma Phe concentrations at the different points. Our results indicate that PKU patients under classical treatment have decreased platelet serotonin concentrations, probably owing to continued high Phe values, while BH4 supplementation restored platelet serotonin values.
Trial of erythropoietin treatment in a boy with glutathione synthetase deficiency
Authors: Sykut‐Cegielska J. , Jurecka A. , Taybert J. , Gradowska W. , Pajdowska M. , Pronicka E.
Published: January 2006

We report a 3‐year‐old boy with glutathione synthetase deficiency, who in the newborn period developed severe persistent haemolytic anaemia. Treatment with erythropoietin was introduced with good clinical and haematological response.
Social outcome in treated individuals with inherited metabolic disorders: UK study
Authors: Bhat M. , Haase C. , Lee P. J.
Published: January 2006

Few data exist on the long‐term social outcome of patients with inherited metabolic disorders, despite the fact that increasing numbers are surviving into adulthood. Here we report the findings of 329 patients aged from 11 to 70 years, of whom 172 had phenylketonuria, 38 had homocystinuria and 33 had galactosaemia. Twenty‐eight per cent had no formal education qualifications, 59% were employed, but only 17% were in professional jobs (social classes I and II). The time of diagnosis and treatment had a significant impact on outcome in phenylketonuria, as did pyridoxine responsiveness or lack of it in homocystinuria. Effects on outcome in galactosaemia were not clear. Social integration is an important outcome of treatment of chronic disorders in childhood and warrants further study in this growing patient population.
Asymptomatic adults and older siblings with biotinidase deficiency ascertained by family studies of index cases
Authors: Baykal T. , Gokcay G. , Gokdemir Y. , Demir F. , Seckin Y. , Demirkol M. , Jensen K. , Wolf B.
Published: January 2006

We report 32 biotinidase‐deficient patients detected by family studies in the index cases. The study group consisted of 10 mothers, 4 fathers and 18 siblings. There were 17 individuals (3 mothers, 4 fathers and 10 siblings) with profound biotinidase deficiency (BD) (< 10% of mean normal activity) and 15 (7 mothers and 8 siblings) with partial BD (10–30% of mean normal activity). In the profound BD group, only three siblings were symptomatic. Dermatitis, microcephaly, developmental delay and convulsions were observed. The patients with partial BD did not have any clinical symptoms except one sibling with borderline IQ score. None of the parents was symptomatic. Family investigation of patients with BD is very important for the detection of asymptomatic patients who are at risk of exhibiting symptoms at any age. Careful evaluation of these untreated individuals with BD is important to obtain additional information about the natural history of this disorder and may provide clues to phenotype–genotype relationships and treatment regimes.
Congenital disorder of glycosylation type Ia in a 6‐year‐old girl with a mild intellectual phenotype: Two novel PMM2 mutations
Authors: Coman D. , Klingberg S. , Morris D. , McGill J. , Mercer H.
Published: January 2006

We report two novel mutations in the PMM2 gene in a girl with congenital disorder of gylcosylation type Ia (CDG Ia) and a mild intellectual phenotype.
Globoid cell leukodystrophy (Krabbe disease): Normal umbilical cord blood galactocerebrosidase activity and polymorphic mutations
Authors: Raghavan S. , Zeng B. , Torres P. A. , Pastores G. M. , Kolodny E. H. , Kurtzberg J. , Krivit W.
Published: January 2006

Globoid cell leukodystrophy is an inherited metabolic disorder of the central nervous system caused by deficiency of the lysosomal enzyme galactocerebrosidase. Haematopoietic stem cell transplantation is the only available effective treatment. The engraftment from normal donors provides competent cells able to correct the metabolic defect. Umbilical cord blood cells have proved to significantly decrease complications and improve engraftment rate compared to adult marrow cells in haematopoietic stem cell transplantation. Umbilical cord blood cells must be of sufficient activity to provide central nervous system recovery after engraftment is obtained.

Galactocerebrosidase activity is known to be affected by two polymorphic alleles found at nucleotides 502 and 1637 of the cDNA for this gene. This enzyme activity and the polymorphic alleles noted above were analysed in 83 random samples of umbilical cord blood. The activity, assayed with the fluorogenic substrate 6‐hexadecanoylamino‐4‐methylumbelliferyl‐β‐galactopyranoside, in those with neither polymorphic allele was 4.6 ± 1.7 units (nmol/h per mg protein). This optimal choice of cord blood was found in only 24% of specimens. Homozygotes for 1637T > C with activity of only 1.5 ± 0.4 units represented 16% of the samples. Those heterozygous for 1637T > C with slightly better activity (2.3 ± 0.7 units) represented 52% of the samples. Choice of umbilical cord blood for haematopoietic stem cell transplantation, therefore, requires consideration not only of cell quantity and HLA compatibility but also selection for normal alleles to obtain maximal enzymatic activity for central nervous system correction.
Severe hypoglycaemia in isolated 3‐methylcrotonyl‐CoA carboxylase deficiency; a rare, severe clinical presentation
Authors: Oude Luttikhuis H. G. M. , Touati G. , Rabier D. , Williams M. , Jakobs C. , Saudubray J. M.
Published: January 2006

Since the introduction of neonatal screening for branched‐chain organic acidurias, it has been noted that isolated 3‐methylcrotonyl‐CoA carboxylase deficiency is probably one of the most frequent organic acidurias. Only a few cases with severe clinical presentation have been described. Profound hypoglycaemia is an uncommon but life‐threatening complication.
Purification and characterization of chymosin and pepsin from kid
Authors: Moschopoulou Ekaterini E , Kandarakis Ioannis G , Alichanidis Efstathios , Anifantakis Emmanouil M
Published: January 2006

The objective of this work was to study the characteristics of the gastric aspartic proteinases chymosin and pepsin which are constituents of the kid rennet. The two enzymes were extracted from abomasal tissue of one kid from a local indigenous breed, separated from each other by DEAE-cellulose chromatography and then were purified by gel filtration and anion-exchange chromatography. The molecular weights of the purified kid chymosin and pepsin as determined by gel filtration were 36 kDa and 40 kDa respectively. The isoelectric point of kid chymosin was as multiple forms of 3–6 zones at pH 4·6–5·1, while that of kid pepsin was at pH [les ]3·0. Kid pepsin contained 0·37 molecules phosphorous per molecule and was totally inhibited by 5 μM pepstatin A, being more sensitive than kid chymosin. Both enzymes were almost equally as proteolytic as calf chymosin on total casein at pH 5·6. Kid pepsin activity was more pH and temperature dependent than kid chymosin activity. In comparison with the calf chymosin temperature sensitivity, the order of increased sensitivity was: calf chymosin <kid chymosin <kid pepsin.
pH-Dependent behaviour of soluble protein aggregates formed during heat-treatment of milk at pH 6·5 or 7·2
Authors: Renan Marie , Mekmene Omar , Famelart Marie-Hélène , Guyomarc'h Fanny , Arnoult-Delest Véronique , Pâquet Denis , Brulé Gérard
Published: January 2006

The pH-dependent behaviour of soluble protein aggregates produced by the pre-heating of reconstituted skim milk at 90 °C for 10 min was studied, in order to understand the role of these aggregates in acid gelation of heated milk. The following milk samples were prepared: (1) control (unheated reconstituted milk, pH 6·5); (2) milk heat-treated at pH 6·5 (mHtd6·5) and (3) milk heat-treated at pH 7·2 (mHtd7·2). They were centrifuged and the supernatants (SPNT 1) pH-adjusted to yield a series of pH values ranging from 6·5 or 7·2 to 4·6 using HCl at 20 °C or GDL at 20 and 38 °C. pH-Adjusted SPNTs 1 were re-centrifuged. The resulting supernatants (SPNTs 2) were analysed by OD (at 600 and 280 nm) and SDS-PAGE in order to characterise proteins still soluble as a function of pH. Particle size in SPNTs 1 was analysed by Steric Exclusion Chromatography. The OD600 nm revealed that during acidification soluble casein in both control and heat-treated samples exhibits variations in its optical properties or size as previously shown with micellar casein. In heat-treated samples, soluble casein and heat-induced covalent soluble aggregates precipitate at the same pH value. A progressive acidification of the soluble phase did not separate them. Increasing the temperature of acidification from 20 to 38 °C resulted in an increase in the precipitation pH of the proteins. However choice of acidifier did not have a significant effect on OD profiles. The soluble covalent aggregates from mHtd7·2 were smaller, more numerous, and had a higher content of κ-casein than mHtd6·5. Both types of aggregates began to precipitate at the same pH value but precipitation occurred over a narrower pH-range for soluble aggregates prepared from mHtd7·2. This may explain the higher gelation pH of mHtd7·2 compared with mHtd6·5.
Distribution of molecular subtypes within Salmonella enterica serotype Enteritidis phage type 4 and S. Typhimurium definitive phage type 104 in nine European countries, 2000–2004: results of an international multi-centre study
Authors: GATTO A. J. , PETERS T. M. , GREEN J. , FISHER I. S. T. , GILL O. N. , O'BRIEN S. J. , MAGUIRE C. , BERGHOLD C. , LEDERER I. , GERNER-SMIDT P. , TORPDAHL M. , SIITONEN A. , LUKINMAA S. , TSCHÄPE H. , PRAGER R. , LUZZI I. , DIONISI A. M. , VAN DER ZWALUW W. K. , HECK M. , COIA J. , BROWN D. , USERA M. , ECHEITA A. , THRELFALL E. J.
Published: January 2006

This study investigates the distribution of pulsed-field gel electrophoresis (PFGE) profiles within Salmonella enterica serotype Enteritidis phage type (PT) 4 and S. Typhimurium definitive phage type (DT) 104, from cases of human infection in nine European countries from 2000 to 2004. Isolates were subtyped using standardized methods and gel images submitted by each participating country to the coordinating centre (Health Protection Agency Centre for Infections, London, UK), where they were entered into a central database, developed within BioNumerics software, and designated using an agreed nomenclature. S. Enteritidis PT4 (n=3637) was differentiated into 38 different profiles. Simpson's index of diversity (D) of profiles ranged from 0·2 to 0·4. Profile SENTXB.0001 represented at least 80% of all profiles in each country. S. Typhimurium DT104 (n=1202) was differentiated into 28 different profile types. Simpson's D was at least 0·6 in all countries except in Austria and Italy. In both these countries over 74% of S. Typhimurium DT104 profiles were STYMXB.0013. Profile STYMXB.0061, was predominant in Denmark, Spain, Finland and England & Wales where it represented between 36% and 45% of profiles. Profile STYMXB.0001 represented nearly half of all profiles in Scotland and 23% in England & Wales. PFGE is proving useful for further discrimination within S. Enteritidis PT4 and S. Typhimurium DT104. Ascertainment of international outbreaks involving common serotypes and phage types may be increased by the timely pooling of PFGE profiles within a central database readily accessible to all participating countries.
Absolute paleointensity at 1.27 Ga from the Mackenzie dyke swarm (Canada)
Authors: Macouin M. , Valet J. P. , Besse J. , Ernst R. E.
Published: January 2006

Paleointensity studies have been conducted on 6 mafic dykes from the 1270 Ma Mackenzie swarm in the Slave Province (Canada). The mean direction of the characteristic magnetization coincides with results of an earlier study in which the primary origin of the magnetization was established on the basis of a contact test. High unblocking temperatures, magnetic mineralogy, and grain‐size experiments suggest that the magnetization is dominated by pseudo‐single domain or single domain grains of magnetite. Paleointensity experiments were conducted with a specially designed oven, using a revised version of the Thellier‐Coe method. Thirteen successful determinations of paleointensity were obtained for 4 dykes. The paleofield estimates vary between 4.3 and 22.1 μT, yielding virtual dipole moments (VDMs) between 1.3 ± 0.2 and 4.5 ± 0.9 × 1022 Am2. These new results increase the number of low field determinations during the Precambrian, which largely dominate the database with an averaged field of 3.1 ± 2.5 × 1022 Am2. They also emphasize the importance of additional studies to understand the differences with the strong paleointensities obtained using new techniques.
Correction of direct irradiance measurements of Brewer spectrophotometers due to the effect of internal polarization
Authors: Cede Alexander , Kazadzis Stelios , Kowalewski Matt , Bais Alkis , Kouremeti Natalia , Blumthaler Mario , Herman Jay
Published: January 2006

Due to the combined effect of two polarization sensitive elements, the entrance window and grating, the sensitivity of Brewer spectrophotometers for direct‐sun measurements changes with solar zenith angle (SZA). We determined this SZA‐polarization dependence with four independent methods, which agreed within ±1.5%. For SZA < 50° this effect is negligible. At SZA = 60°, 70°, and 80° the Brewer's sensitivity is reduced by 1%, 4%, and 10%, relative to SZA = 35°, when the direct solar irradiance is perpendicular to the entrance window. Differential absorption algorithms for retrieving trace gases (e.g., ozone) are unaffected since the polarization effect is almost wavelength independent. However, systematic errors are introduced in Langley extrapolations (2–4% overestimation of the zero air mass factor), retrievals of aerosol optical depth (overestimation of 0.01–0.04), and aerosol single scattering albedo. Therefore, Brewer direct irradiance measurements should be corrected for the SZA‐polarization dependence. The effect in sky‐radiance measurements can be removed only by hardware modifications.
A model of the earthquake cycle along the San Andreas Fault System for the past 1000 years
Authors: Smith Bridget R. , Sandwell David T.
Published: January 2006

We simulate 1000 years of the earthquake cycle along the San Andreas Fault System by convolving best estimates of interseismic and coseismic slip with the Green's function for a point dislocation in an elastic plate overlying a viscoelastic half‐space. Interseismic slip rate is based on long‐term geological estimates while fault locking depths are derived from horizontal GPS measurements. Coseismic and postseismic deformation is modeled using 70 earthquake ruptures, compiled from both historical data and paleoseismic data. This time‐dependent velocity model is compared with 290 present‐day geodetic velocity vectors to place bounds on elastic plate thickness and viscosity of the underlying substrate. Best fit models (RMS residual of 2.46 mm/yr) require an elastic plate thickness greater than 60 km and a substrate viscosity between 2 × 1018 and 5 × 1019 Pa s. These results highlight the need for vertical velocity measurements developed over long time spans (>20 years). Our numerical models are also used to investigate the 1000‐year evolution of Coulomb stress. Stress is largely independent of assumed rheology, but is very sensitive to the slip history on each fault segment. As expected, present‐day Coulomb stress is high along the entire southern San Andreas because there have been no major earthquakes over the past 150–300 years. Animations S1 and S2 of the time evolution of vector displacement and Coulomb stress are available as auxiliary material.
Low Vp/Vs ratios in the crust and upper mantle beneath the Sea of Okhotsk inferred from teleseismic pMP, sMP, and sMS underside reflections from the Moho
Authors: Zheng Yingcai , Lay Thorne
Published: January 2006

Teleseismic ground motion recordings of deep earthquakes often contain clear seismic wave reflections from the free surface above the source (pP, sP, sS), with isolated precursors (pMP, sMP, and sMS) produced by underside reflections from the Moho (the crust‐mantle boundary) below the free surface reflection points. The waveforms of the depth phases and their precursors are readily modeled, providing constraints, for steep angles of incidence, on integrated two‐way crustal travel times and Moho shear and compressional impedance contrasts above deep earthquake source regions. We model surface reflection waveforms in stacks of three‐component, long‐period WWSSN and digital broadband seismograms for signals traversing the crust and upper mantle beneath the Sea of Okhotsk, which overlies deep earthquakes in the subducted Kurile slab. The crust beneath most of the Sea of Okhotsk is 19–25 km thick, indicating a submerged continental margin, with minor crustal thinning toward the Kuril back‐arc basin, where thin oceanic crust is found. Modeling pMP and sMS phases that sample the same subregion provides tight constraints on the Vp/Vs ratio in the crust and uppermost mantle (assuming common density structure and consistent crustal thickness for P and S waves); the absolute velocities are not constrained by the data. We find unusually low Vp/Vs ratios in the range 1.6–1.7 for the uppermost mantle under the Sea of Okhotsk and comparably low average Vp/Vs ratios for the crust in several regions. The presence of fluids and extensive silica enrichment, possibly involving low‐temperature veining, are viable explanations for the anomalous Vp/Vs ratios; this may represent an important process of continentalization taking place landward from the volcanic arc in subduction zones.
Evaluation of daytime measurements of aerosols and water vapor made by an operational Raman lidar over the Southern Great Plains
Authors: Ferrare Richard , Turner David , Clayton Marian , Schmid Beat , Redemann Jens , Covert David , Elleman Robert , Ogren John , Andrews Elisabeth , Goldsmith John E. M. , Jonsson Haflidi
Published: January 2006

Raman lidar water vapor and aerosol extinction profiles acquired during the daytime over the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site in northern Oklahoma (36.606 N, 97.50 W, 315 m) are evaluated using profiles measured by in situ and remote sensing instruments deployed during the May 2003 Aerosol Intensive Operations Period (IOP). The automated algorithms used to derive these profiles from the Raman lidar data were first modified to reduce the adverse effects associated with a general loss of sensitivity of the Raman lidar since early 2002. The Raman lidar water vapor measurements, which are calibrated to match precipitable water vapor (PWV) derived from coincident microwave radiometer (MWR) measurements were, on average, 5–10% (0.3–0.6 g/m3) higher than the other measurements. Some of this difference is due to out‐of‐date line parameters that were subsequently updated in the MWR PWV retrievals. The Raman lidar aerosol extinction measurements were, on average, about 0.03 km−1 higher than aerosol measurements derived from airborne Sun photometer measurements of aerosol optical thickness and in situ measurements of aerosol scattering and absorption. This bias, which was about 50% of the mean aerosol extinction measured during this IOP, decreased to about 10% when aerosol extinction comparisons were restricted to aerosol extinction values larger than 0.15 km−1. The lidar measurements of the aerosol extinction/backscatter ratio and airborne Sun photometer measurements of the aerosol optical thickness were used along with in situ measurements of the aerosol size distribution to retrieve estimates of the aerosol single scattering albedo (ωo) and the effective complex refractive index. Retrieved values of ωo ranged from (0.91–0.98) and were in generally good agreement with ωo derived from airborne in situ measurements of scattering and absorption. Elevated aerosol layers located between about 2.6 and 3.6 km were observed by the Raman lidar on 25 and 27 May. The airborne measurements and lidar retrievals indicated that these layers, which were likely smoke produced by Siberian forest fires, were primarily composed of relatively large particles (reff ∼ 0.23 μm) and that the layers were relatively nonabsorbing (ωo ∼ 0.96–0.98). Preliminary results show that major modifications that were made to the Raman lidar system during 2004 have dramatically improved the sensitivity in the aerosol and water vapor channels and reduced random errors in the aerosol scattering ratio and water vapor retrievals by an order of magnitude.
Phosphate concentration and association as revealed by sequential extraction and microprobe analysis: The case of sediments from two Argentinean reservoirs
Authors: Borgnino L. , Orona C. , Avena M. , Maine M. A. , Rodríguez A. , De Pauli C. P.
Published: January 2006

This article reports the general characteristics of the sediments of two Argentinean reservoirs, which are used for water supply. The chemical composition, granulometry, and specific surface area are presented together with a study of total phosphate concentration and phosphate association by combining sequential extraction and microprobe analysis. In general, the sediments of both reservoirs have similar characteristics. Sequential extraction reveals that the main P fractions in the studied sediments are Ca‐bound phosphate in river mouths and Fe‐bound phosphate in the rest of the reservoir stations. Microprobe analysis appears to be an important complementary technique to sequential extraction. Combined with chemical fractionation and specific surface area measurements, these analyses indicate that Ca‐bound phosphate is mainly distributed within grains or particles highly concentrated in Ca and P, whereas Fe‐bound phosphate is rather homogeneously distributed in the sediments at the surface of fine particles. Microprobe analyses also revealed an important coating of phyllosilicate surfaces with Fe (hydr)oxides, which explains the good correlation found between Fe‐bound phosphate, clay fraction, and specific surface area. The role of sediments as a potential source of phosphate is discussed in terms of P association in the solid phase and dissolved oxygen concentration profiles in the water column.
Explicit solutions of the classical Calogero and Sutherland systems for any root system
Authors: Sasaki R. , Takasaki K.
Published: January 2006

Explicit solutions of the classical Calogero (rational with/without harmonic confining potential) and Sutherland (trigonometric potential) systems is obtained by diagonalization of certain matrices of simple time evolution. The method works for Calogero & Sutherland systems based on any root system. It generalizes the well-known results by Olshanetsky and Perelomov for the A type root systems. Explicit solutions of the (rational and trigonometric) higher Hamiltonian flows of the integrable hierarchy can be readily obtained in a similar way for those based on the classical root systems.
Surface-layer effect in CaCu3Ti4O12
Authors: Wang C. C. , Zhang L. W.
Published: January 2006

Low-frequency (∼100Hz) dielectric properties of CaCu3Ti4O12 were investigated in detail near room temperature. A dielectric relaxation peak was observed at about 250 K with an activation energy of 0.54 eV. This peak can be tuned by annealing treatment in nitrogen and oxygen. The results can be well explained by considering the surface-layer effect. The inhomogeneous distribution of oxygen vacancies leads to the formation of surface layer, resulting in the observed Maxwell–Wagner-type dielectric relaxation.
Anisotropy of domain broadening in periodically poled lithium niobate crystals
Authors: Sheng Yan , Wang Ting , Ma Boqin , Qu E , Cheng Bingying , Zhang Daozhong
Published: January 2006

We experimentally study the dependence of reversed domain broadening of lithium niobate (LiNbO3) wafers on their poling electrode configurations. Experiments show that the reversed domain area is anisotropic and has 60° symmetry. The slightest domain broadening takes place as the poling stripe electrode parallels to the diagonals of hexagonal domain walls. We suppose the anisotropy of domain expansions is directly related to the symmetry of LiNbO3 crystal lattices, and it can be understood by considering the anisotropoic distributions of tangential component of electric field and the spontaneous polarization on domain walls.
Emotion enhances remembrance of neutral events past
Authors: Anderson Adam K. , Wais Peter E. , Gabrieli John D. E.
Published: January 2006

Emotional events are bestowed with special prominence in memory. This may reflect greater attention oriented to these events during encoding, and/or enhancement of memory consolidation after emotional events have passed. Here we show invoked emotional arousal results in a retrograde enhancement of long-term memory, determining what will later be remembered or forgotten. Subjects saw pictures of neutral faces and houses followed by emotionally arousing scenes at varying intervals. Self-reported emotional arousal responses predicted a retrograde enhancement of memory for preceding neutral events in a 1-week delayed recognition memory test. At longer picture-scene intervals, no enhancement was found, implicating a critical window in which emotional arousal must occur for retrograde memory enhancement. Postencoding manipulation of emotional arousal specifically enhanced conscious recollection rather than familiarity-based discrimination. An additional study revealed no retrograde enhancement for pictures preceding highly memorable, but nonarousing, distinctive scenes. These findings indicate an important role for emotional arousal in the postencoding enhancement of episodic memory consolidation.
Zinc supplementation of young men alters metallothionein, zinc transporter, and cytokine gene expression in leukocyte populations
Authors: Aydemir Tolunay Beker , Blanchard Raymond K. , Cousins Robert J.
Published: January 2006

An effective measure to assess zinc status of humans has remained elusive, in contrast to iron, where a number of indicators of metabolism/function are available. Using monocytes, T lymphocytes, and granulocytes isolated by magnetic sorting and dried blood spots (DBS) derived from 50 μl of peripheral blood, we evaluated the response of metallothionein (MT), zinc transporter, and cytokine genes to a modest (15 mg of Zn per day) dietary zinc supplement in human subjects. Transcript abundance was measured by quantitative real-time RT-PCR (QRT-PCR). Zinc supplementation increased MT mRNA abundance by up to 2-fold in RNA from leukocyte subsets, and 4-fold in RNA from DBS. Transcript levels for the zinc transporter genes ZnT1 and Zip3 were increased and decreased, respectively, by zinc supplementation. Expression of the ZnT and Zip genes among leukocyte subsets differ by up to 270-fold. Monocytes and granulocytes from supplemented subjects were activated by LPS, whereas T lymphocytes were activated by mimicking antigen presentation. With zinc consumption, TNF-α and IL-1β expression was greater in activated monocytes and granulocytes, and IFN-γ mRNA levels were higher in activated T lymphocytes. These studies show that QRT-PCR is a tool to reliably measure transcript abundance for nutritionally responsive genes in human subjects, and that a small sample of whole dried blood, when appropriately collected, can be used as the source of total RNA for QRT-PCR analysis. The results obtained also show that zinc supplementation of human subjects programs specific leukocytic subsets to show enhanced cytokine expression upon activation by stimulators of immunity.
LuxS impacts on LytA-dependent autolysis and on competence in Streptococcus pneumoniae
Authors: Romao Susana , Memmi Guido , Oggioni Marco R. , Trombe Marie-Claude
Published: January 2006

The ubiquitous protein LuxS with S-ribosylhomocysteinase activity is involved in S-adenosyl methionine detoxification, C-1 unit recycling and the production of autoinducers that allow the cell to sense and respond to cell density. Independent reports describe the impact of LuxS deficiency on Streptococcus pneumoniae virulence in the mouse. In vitro, LuxS deficiency confers discrete phenotypes. A combined approach using genetic dissection and mixed-culture experiments allowed the involvement of LuxS in the developmental physiology of S. pneumoniae to be investigated. Functional LuxS was found to be related on the one hand to down-regulation of competence, and on the other hand to attenuation of autolysis in cultures entering stationary phase. The competence phenotype of luxS mutant bacteria was complemented by media conditioned by competence-defective ComAB0 bacteria, but not by BSA. The autolytic phenotype was complemented by BSA, but not by conditioned supernatants. It is suggested that the impact of LuxS on competence, but not on autolysis, involves cell–cell communication. The phenotype of luxS mutant strains reveals a hierarchy in the competence regulatory networks of S. pneumoniae.
Zinc metalloproteinase genes in clinical isolates of Streptococcus pneumoniae: association of the full array with a clonal cluster comprising serotypes 8 and 11A
Authors: Camilli Romina , Pettini Elena , Grosso Maria Del , Pozzi Gianni , Pantosti Annalisa , Oggioni Marco R.
Published: January 2006

Pneumococci display large zinc metalloproteinases on the surface, including the IgA protease, which cleaves human IgA1 in the hinge region, the ZmpC proteinase, which cleaves human matrix metalloproteinase 9 (MMP-9), and two other proteinases, ZmpB and ZmpD, whose substrates have not yet been identified. Surface metalloproteinases are antigenic and have been linked to virulence. The genes encoding these proteinases reside in three distinct loci: two loci specific forzmpBandzmpC, and a third, theigalocus, containingigaandzmpD. Data obtained by this and other groups have shown that pneumococcal metalloproteinase genes are transcribed and yield mature and enzymatically active proteins. Since the presence of the four proteinase genes is variable in the pneumococcal strains whose genomes have been sequenced, the presence of these genes in a collection of 218 pneumococcal isolates, mostly from invasive disease, was investigated. The data showed thatzmpBandigawere present in all the isolates examined, whilezmpCandzmpDwere present in a variable proportion of the isolates (in 18 and 49 %, respectively). Interestingly, isolates carrying bothzmpCandzmpDwere found to belong mainly to two serotypes (sts), 8 and 11A. By molecular typing, st 8 and st 11A isolates appeared to belong to the same clonal cluster. The presence of these two additional metalloproteinases could contribute to the fitness of particular pneumococcal clones.
Distribution of epidemic antibiotic-resistant pneumococcal clones in Scottish pneumococcal isolates analysed by multilocus sequence typing
Authors: Smith A. J. , Jefferies J. , Clarke S. C. , Dowson C. , Edwards G. F. S. , Mitchell T. J.
Published: January 2006

Sequence types of pneumococci isolated in Scotland between 1996 and 2003 were compared with those of globally prevalent antibiotic-resistant clones. Multilocus sequence typing was performed on 252 invasive pneumococcal isolates referred to the Scottish Meningococcus and Pneumococcus Reference Laboratory. Isolates were not preselected for antimicrobial resistance, patient age or disease caused. Sequence types were compared with globally significant antimicrobial-resistant clones identified by the Pneumococcal Molecular Epidemiology Network (PMEN). Sequence types identical with three of the 26 PMEN clones were present in the Scottish collection; the clones were the Spain9V-3 clone (sequence type 156, seven isolates), the England14-9 clone (sequence type 9, eight isolates) and the Utah35B-24 clone (sequence type 377, one isolate). Many Scottish isolates related to PMEN clones had lower antimicrobial MICs than those described for the corresponding PMEN type strain. A number of single- (SLVs) and double-locus variants (DLVs) were present. Fifteen SLVs related to PMEN sequence types 37, 67, 90, 81, 156, 236 and 377 were detected. The collection contained 10 DLVs related to PMEN sequence types 37, 156, 173 and 338. The majority of SLVs and DLVs were penicillin- or erythromycin-sensitive variants of the resistant PMEN type strains. Capsule switching in isolates related to the PMEN clones was also detected. The highest levels of penicillin resistance were detected in sequence type 320 (serotype 19F), which is not a PMEN clone. These data suggest that PMEN clones are not widely distributed in disease-causing isolates in Scotland.
Regulation of Serratia marcescens ompF and ompC porin genes in response to osmotic stress, salicylate, temperature and pH
Authors: Begic Sanela , Worobec Elizabeth A.
Published: January 2006

Serratia marcescensis a Gram-negative enterobacterium that has become an important opportunistic pathogen, largely due to its high degree of natural antibiotic resistance. One factor contributing to this natural antibiotic resistance is reduced outer membrane permeability, which is controlled in part by OmpC and OmpF porin proteins. OmpF expression is regulated bymicF, an RNA transcript encoded upstream of theompCgene, which hybridizes with theompFtranscript to inhibit its translation. Regulation ofS. marcescensporin gene expression, as well as that ofmicF, was investigated usingβ-galactosidase reporter gene fusions in response to 5, 8 and 10 % sucrose, 1, 5 and 8 mM salicylate, and different pH and temperature values.β-Galactosidase activity assays revealed that a lower growth temperature (28 °C), a more basic pH (pH 8), and an absence of sucrose and salicylate induce the transcription of theompFgene, whereas the induction ofompCis stimulated at a higher growth temperature (42 °C), acidic pH (pH 6), and maximum concentrations of sucrose (10 %) and salicylate (8 mM). In addition, when multiple conditions were tested, temperature had the predominant effect, followed by pH. In this study, it was found that the MicF regulatory mechanism does not play a role in the osmoregulation of theompFandompCgenes, whereas MicF does repress OmpF expression in the presence of salicylate and high growth temperature, and under low pH conditions.
Putative glycogen-accumulating organisms belonging to the Alphaproteobacteria identified through rRNA-based stable isotope probing
Authors: Meyer Rikke Louise , Saunders Aaron Marc , Blackall Linda Louise
Published: January 2006

Deterioration of enhanced biological phosphorus removal (EBPR) has been linked to the proliferation of glycogen-accumulating organisms (GAOs), but few organisms possessing the GAO metabolic phenotype have been identified. An unidentified GAO was highly enriched in a laboratory-scale bioreactor and attempts to identify this organism using conventional 16S rRNA gene cloning had failed. Therefore, rRNA-based stable isotope probing followed by full-cycle rRNA analysis was used to specifically identify the putative GAOs based on their characteristic metabolic phenotype. The study obtained sequences from a group of Alphaproteobacteria not previously shown to possess the GAO phenotype, but 90 % identical by 16S rRNA gene analysis to a phylogenetic clade containing cloned sequences from putative GAOs and the isolate Defluvicoccus vanus. Fluorescence in situ hybridization (FISH) probes (DF988 and DF1020) were designed to target the new group and post-FISH chemical staining demonstrated anaerobic–aerobic cycling of polyhydroxyalkanoates, as per the GAO phenotype. The successful use of probes DF988 and DF1020 required the use of unlabelled helper probes which increased probe signal intensity up to 6·6-fold, thus highlighting the utility of helper probes in FISH. The new group constituted 33 % of all Bacteria in the lab-scale bioreactor from which they were identified and were also abundant (51 and 55 % of Bacteria) in two other similar bioreactors in which phosphorus removal had deteriorated. Unlike the previously identified Defluvicoccus-related organisms, the group identified in this study were also found in two full-scale treatment plants performing EBPR, suggesting that this group may be industrially relevant.
Production and properties of the native Chromobacterium violaceum fucose-binding lectin (CV-IIL) compared to homologous lectins of Pseudomonas aeruginosa (PA-IIL) and Ralstonia solanacearum (RS-IIL)
Authors: Zinger-Yosovich Keren , Sudakevitz Dvora , Imberty Anne , Garber Nachman C. , Gilboa-Garber Nechama
Published: January 2006

Chromobacterium violaceum is a versatile, violet pigment (violacein)-producing β-proteobacterium, confined to tropical and subtropical regions, dwelling in soil and water, like Pseudomonas aeruginosa and Ralstonia solanacearum. These three bacteria are saprophytes that occasionally become aggressive opportunistic pathogens virulently attacking animals (the first two) and plants (the third). The recent availability of their genome sequences enabled identification in the C. violaceum genome of an ORF (locus no. 1744) that is similar to those of P. aeruginosa and R. solanacearum lectins, PA-IIL and RS-IIL, respectively. A recombinant protein, CV-IIL, encoded by that ORF exhibited fucose>mannose-specific lectin activity resembling PA-IIL. This paper describes production and properties of the native CV-IIL, which, like PA-IIL and RS-IIL, is probably also a quorum-sensing-driven secondary metabolite, appearing concomitantly with violacein. Its formation is repressed in the CV026 mutant of C. violaceum, which lacks endogenous N-acylhomoserine lactone. The upstream extragenic sequence of its ORF contains a 20 bp sequence (5′-101–120) with partial similarities to the luxI-box and the related P. aeruginosa and R. solanacearum promoter boxes of quorum-sensing-controlled genes. The lectin level is augmented by addition of trehalose to the medium. The subunit size of CV-IIL (around 11·86 kDa) is similar to those of PA-IIL (11·73 kDa) and RS-IIL (11·60 kDa). Like PA-IIL, in the tetrameric form CV-IIL preferentially agglutinates α1-2 fucosylated H-positive human erythrocytes (regardless of their A, B or O type), as opposed to the Oh Bombay type, but differs from it in having no interaction with rabbit erythrocytes and in displaying stronger affinity to l-galactose than to l-fucose. The greater similarity of CV-IIL to PA-IIL than to RS-IIL might be related to the selective adaptation of both C. violaceum and P. aeruginosa to animal tissues versus the preferential homing of R. solanacearum to plants.
The DNA-binding domain of the Escherichia coli CpxR two-component response regulator is constitutively active and cannot be fully attenuated by fused adjacent heterologous regulatory domains
Authors: Tapparel Caroline , Monod Antoinette , Kelley William L.
Published: January 2006

Two-component systems (TCS) based on a sensor histidine kinase and a phosphorylated cognate target regulator allow rapid responses to environmental changes. TCS are highly evolutionarily conserved, though in only a few cases are the inducing signals understood. This study focuses on theEscherichia coliCpxR response regulator that responds to periplasmic and outer-membrane stress. N-terminal deletion mutations have been isolated that render the transcription factor constitutively active, indicating that the N terminus functions, in part, to keep the C-terminal winged-helix DNA-binding effector domain in an inactive state. Analysis of truncations spanning the CpxR interdomain region revealed that mutants retaining theα5 helix significantly augment activation. Hybrid proteins obtained by fusing the CpxR effector domain to structurally similar heterologous N-terminal regulatory domains, or even GFP, failed to restore repression to the C-terminal domain. These findings shed light on the mechanism of CpxR effector domain activation and on the investigation of constitutive mutants obtained by truncation in other TCS.
Identification, prevalence and population structure of non-typable Streptococcus pneumoniae in carriage samples isolated from preschoolers attending day-care centres
Authors: Sá-Leão Raquel , Simões Alexandra S. , Nunes Sónia , Sousa Natacha G. , Frazão Nelson , de Lencastre Hermínia
Published: January 2006

The authors aimed to get insights into the population structure of non-(sero)typable pneumococci (NTPn), a specific group of natural atypical pneumococci whose identification is often difficult, and which has remained insufficiently studied. A total of 265 presumptive NTPn, isolated between 1997 and 2003 from the nasopharynx of children, were characterized. Strains were confirmed to be pneumococci on the basis of bile solubility, and PCR detection or Southern blotting hybridization oflytAandpsaA, genes ubiquitous in this species. Multilocus sequence typing (MLST) was used to exclude two isolates that gave ambiguous results. Non-typability was confirmed by the Quellung reaction using Omniserum. A total of 213 isolates were considered to be true NTPn. The molecular analysis of the true NTPn by PFGE and MLST showed that this population was genetically diverse, although a dominant cluster, accounting for 66 % of the isolates, was identified. Antimicrobial resistance was observed in most genetic backgrounds, and multidrug resistance to penicillin, erythromycin, clindamycin, tetracycline and sulfamethoxazole-trimethoprim was associated with strains belonging to the dominant cluster. Comparison with PFGE fingerprints and sequence types of large collections of serotypable strains showed that the genetic backgrounds of all but two NTPn were different from those found in serotypable strains. In addition, we found that NTPn strains with similar genetic backgrounds to those identified in our study had been isolated from disease sources in other countries. These observations seem to indicate that NTPn have diverse genetic backgrounds and may have evolved as a distinct group of pneumococcal isolates.
Structures and the oxygen deficiency of tetragonal and monoclinic zirconium oxide nanoparticles
Authors: Yashima Masatomo , Tsunekawa Shin
Published: January 2006

The crystal structure of zirconium oxide nanoparticles was refined by the Rietveld analysis of synchrotron X-ray powder diffraction data measured at 298 K. In the nanoparticles, two phases of tetragonal ZrO2 − δ (average particle size: 11 ± 2 nm) and monoclinic ZrO2 (average particle size: 24 ± 4 nm) existed, where the weight fractions were estimated to be 84.9 and 15.1 wt%, respectively. The structural refinement suggests that the tetragonal ZrO2 − δ has an oxygen deficiency [δ = 0.031 (7)] and that the monoclinic ZrO2 − δ has less oxygen deficiency (δ ≃ 0), where δ is the vacancy concentration. The monoclinic ZrO2 has a larger unit-cell volume. The maximum-entropy method analysis indicated covalent bonding between Zr and O atoms.
Five varieties of hydrogen bond in 1-formyl-3-thiosemicarbazide: an electron density study
Authors: Munshi Parthapratim , Thakur Tejender S. , Guru Row Tayur N. , Desiraju Gautam R.
Published: January 2006

In an attempt to investigate the putative S—H...N hydrogen bond, we have studied the title compound, 1-formyl-3-thiosemicarbazide, which was revealed in a CSD search as a crystal structure which might show such an interaction. However, a redetermination of the structure at room temperature and careful analysis showed that the earlier study [Saxena et al. (1991). Acta Cryst. C47, 2374–2376] on which the CSD search was based was in error and that the possibility of an S—H...N hydrogen bond is negated. The presence of five other varieties of hydrogen bond (N—H...O, N—H...S, N—H...N, C—H...O, C—H...S) in the crystal packing prompted us to redirect our efforts and to undertake a study of the charge-density distribution at 90 K. The topological analysis of these five varieties of hydrogen bond was carried out with Bader's quantum theory of `atoms in molecules' and by applying Koch–Popelier's criteria. The analysis reveals that the hydrogen-bond strength is highest for N—H...O and lowest for C—H...S with N—H...S, N—H...N and C—H...O forming the middle order.
Relationship between structure and photoinitiating abilities of selected bromide salts of 2-oxo-2,3-dihydro-1H-imidazo[1,2-a]pyridine (IMP): influence of the solvent and the substitution in benzaldehyde on the course of its reaction with IMP
Authors: Plutecka Agnieszka , Hoffmann Marcin , Rychlewska Urszula , Kucybała Zdzisław , Pączkowski Jerzy , Pyszka Ilona
Published: January 2006

2-Oxo-2,3-dihydro-1H-imidazo[1,2-a]pyridinium bromide and its C3-substituted derivatives have been synthesized and structurally characterized by X-ray crystallography and quantum chemical calculations. Their potential as photoinitiators for free-radical polymerization has been investigated experimentally and compared with theoretical results. It has been established that the course of the reaction that introduces the substituted benzylidene group to the imidazole ring is different in the protic and dipolar aprotic solvents, and also depends on the character of the substituent, as the energy change in the reaction favours either R
1
R
2C=CHR
3 or R
1
R
2CH—CH(OCH3)R
3 formation.
Monitoring structural transformations in crystals. 8. Monitoring molecules and a reaction center during a solid-state Yang photocyclization
Authors: Turowska-Tyrk Ilona , Trzop Elżbieta , Scheffer John R. , Chen Shuang
Published: January 2006

Structural changes taking place in a crystal during an intramolecular photochemical reaction [the Yang photocyclization of the α-methylbenzylamine salt with 1-(4-carboxybenzoyl)-1-methyladamantane] were monitored step-by-step using X-ray structure analysis. This is the first example of such a study carried out for an intramolecular photochemical reaction. During the photoreaction, both the reactant and product molecules change their orientation, but the reactant changes more rapidly after the reaction is about 80% complete. The distance between directly reacting atoms in the reactant molecule is almost constant until about 80% reaction progress and afterwards decreases. The torsion angle defined by the reactant atoms that form the cyclobutane ring also changes in the final stages of the photoreaction. These phenomena are explained in terms of the influence of many product molecules upon a small number of reacting molecules. The adamantane portion shifts more than the remaining part of the anionic reactant species during the reaction, which is explained in terms of hydrogen bonding. The structural changes are accompanied by changes in the cell constants. The results obtained in the present study are compared with analogous results published for intermolecular reactions.