bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel mutations in ribosomal proteins L4 and L22 that confer erythromycin resistance in Escherichia coli
Authors: Zaman Sephorah , Fitzpatrick Megan , Lindahl Lasse , Zengel Janice 
Published: October 2007

SummaryL4 and L22, proteins of the large ribosomal subunit, contain globular surface domains and elongated ‘tentacles’ that reach into the core of the large subunit to form part of the lining of the peptide exit tunnel. Mutations in the tentacles of L4 and L22 confer macrolide resistance in a variety of pathogenic and non‐pathogenic bacteria. In Escherichia coli, a Lys‐to‐Glu mutation in L4 and a three‐amino‐acid deletion in the L22 had been reported. To learn more about the roles of the tentacles in ribosome assembly and function, we isolated additional erythromycin‐resistant E. coli mutants. Eight new mutations mapped in L4, all within the tentacle. Two new mutations were identified in L22; one mapped outside the tentacle. Insertion mutations were found in both genes. All of the mutants grew slower than the parent, and they all showed reduced in vivo rates of peptide‐chain elongation and increased levels of precursor 23S rRNA. Large insertions in L4 and L22 resulted in very slow growth and accumulation of abnormal ribosomal subunits. Our results highlight the important role of L4 and L22 in ribosome function and assembly, and indicate that a variety of changes in these proteins can mediate macrolide resistance.
Association of chronic stress, depression symptoms and cortisol with low saliva flow in a sample of south‐Brazilians aged 50 years and older
Authors: Hugo Fernando Neves , Hilgert Juliana Balbinot , Corso Samuel , Padilha Dalva Maria Pereira , Bozzetti Mary Clarisse , Bandeira Denise R. , Pawlowski Josiane , Gonçalves Tonantzin Ribeiro 
Published: October 2007

Background:  Few studies have evaluated the relationship between depression symptoms, chronic stress or physiological measures of stress such as cortisol levels and saliva secretion.Objective:  To evaluate the association of low saliva flow with chronic stress, depression symptoms and cortisol in a population aged 50 years and older.Methods:  Participants (n = 227) were recruited from community clubhouses and among dementia caregivers. Stress was assessed using the Lipp’s Stress Symptoms Inventory and salivary cortisol measurements. In addition, taking care of a relative with dementia was included as a proxy variable for chronic stress. Depression was assessed using the Beck Depression Inventory. Saliva flow rate was assessed by measuring unstimulated and chewing‐stimulated saliva flow. Further saliva samples were collected (morning, noon, night) for cortisol analysis by means of radioimmunoassay.Results:  Gender, being a dementia caregiver, self‐reported diabetes and prescriptive medication intake were independently associated with a low stimulated saliva flow. Prescriptive medication intake was also associated with a low unstimulated saliva flow.Conclusion:  Caregiving, a proxy of chronic stress, was associated with low stimulated saliva flow, indicating that stress may have a potential role in salivary gland hypofunction.
A study on the two binding sites of hexokinase on brain mitochondria
Authors: Golestani Abolfazl , Ramshini Hassan , Nemat-Gorgani Mohsen 
Published: October 2007

Abstract

Background
Type I hexokinase (HK-I) constitutes the predominant form of the enzyme in the brain, a major portion of which is associated with the outer mitochondrial membrane involving two sets of binding sites. In addition to the glucose-6-phosphate (G6P)-sensitive site (Type A), the enzyme is bound on a second set of sites (Type B) which are, while insensitive to G6P, totally releasable by use of high concentrations of chaotropic salts such as KSCN. Results obtained on release of HK-I from these "sites" suggested the possibility for the existence of distinct populations of the bound enzyme, differing in susceptibility to release by G6P.

Results
In the present study, the sensitivity of HK-I toward release by G6P (2 mM) and a low concentration of KSCN (45 mM) was investigated using rat brain, bovine brain and human brain mitochondria. Partial release from the G6P-insensitive site occurred without disruption of the mitochondrial membrane as a whole and as related to HK-I binding to the G6P-sensitive site. While, as expected, the sequential regime release-rebinding-release was observed on site A, no rebinding was detectable on site B, pre-treated with 45 mM KSCN. Also, no binding was detectable on mitochondria upon blocking site A for HK-I binding utilizing dicyclohexylcarbodiimide (DCCD), followed by subsequent treatment with KSCN. These observations while confirmed the previously-published results on the overall properties of the two sites, demonstrated for the first time that the reversible association of the enzyme on mitochondria is uniquely related to the Type A site.

Conclusion
Use of very low concentrations of KSCN at about 10% of the level previously reported to cause total release of HK-I from the G6P- insensitive site, caused partial release from this site in a reproducible manner. In contrast to site A, no rebinding of the enzyme takes place on site B, suggesting that site A is 'the only physiologically-important site in relation to the release-rebinding of the enzyme which occur in response to the energy requirements of the brain. Based on the results presented, a possible physiological role for distribution of the enzyme between the two sites on the mitochondrion is proposed.
Parvovirus B19 infection in Tunisian patients with sickle-cell anemia and acute erythroblastopenia
Authors: Regaya Faouzi , Oussaief Lassad , Bejaoui Mohamed , Karoui Mongi , Zili Mohamed , Khelifa Ridha 
Published: October 2007

Abstract

Background
Human parvovirus B19 is the etiologic agent of erythema infectiosum in children. It is also associated with other clinical manifestations in different target groups. Patients with chronic hemolytic anemia are at high risk of developing acute erythroblastopenia following infection by the virus. They usually become highly viremic and pose an increased risk of virus transmission. Close monitoring of such high risk groups is required for epidemiologic surveillance and disease prevention activities. Here we report a molecular epidemiological study on B19 virus infection in Tunisian patients with chronic hemolytic anemia.

Methods
This study was conducted on 92 young chronic hemolytic anemia patients who attended the same ward at the National Bone Marrow Transplantation Center of Tunis and 46 controls from a different hospital. Screening for IgM and IgG anti-B19 antibodies was performed using commercially available enzyme immunoassays and B19 DNA was detected by nested PCR in the overlapping VP1/VP2 region. DNA was sequenced using dideoxy-terminator cycle sequencing technology.

Results
Anti-parvovirus B19 IgG antibodies were detected in 26 of 46 sickle-cell anemia patients, 18 of 46 β-thalassemia and 7 of 46 controls. Anti-parvovirus B19 IgM antibodies were detected only in 4 of the sickle-cell anemia patients: two siblings and two unrelated who presented with acute erythroblastopenia at the time of blood collection for this study and had no history of past transfusion. B19 DNA was detected only in sera of these four patients and the corresponding 288 bp nested DNA amplicons were sequenced. The sequences obtained were all identical and phylogenetic analysis showed that they belonged to a new B19 virus strain of Genotype1.

Conclusion
A new parvovirus B19 strain of genotype1 was detected in four Tunisian patients with sickle-cell anemia. Virus transmission appeared to be nosocomial and resulted in acute erythroblastopenia in the four patients. The possibility of independent transmission of this B19 variant to the patients is unlikely in light of the present epidemiological data. However this possibility cannot be ruled out because of the low genetic variability of the virus.
Webtag: a new web tool providing tags/anchors for RT-PCR experiments with prokaryotes
Authors: Pinto Fernando Lopes , Svensson Håkan , Lindblad Peter 
Published: October 2007

Abstract

Background
Webtag is a tool providing oligonucleotide sequences (usually called tags or anchors) that are absent from a specified genome. These tags/anchors can be appended to gene specific primers for reverse transcriptase polymerase chain reaction experiments, circumventing genomic DNA contamination.

Results
The use of a relational database, in conjunction with a series of scripts written in PHP and Perl, allows the user to rapidly obtain tags that are: 1) suitable for a specific organism, and 2) compatible with other oligonucleotides to be used in the experimental procedures.

Conclusion
This new web tool allows scientists to easily and rapidly obtain suitable tags for RT-PCR experiments, and is available at http://www.egs.uu.se/software/webtag/.
Structure of Arabidopsis thaliana 5-methylthioribose kinase reveals a more occluded active site than its bacterial homolog
Authors: Ku Shao-Yang , Cornell Kenneth A , Howell P Lynne 
Published: October 2007

Abstract

Background
Metabolic variations exist between the methionine salvage pathway of humans and a number of plants and microbial pathogens. 5-Methylthioribose (MTR) kinase is a key enzyme required for methionine salvage in plants and many bacteria. The absence of a mammalian homolog suggests that MTR kinase is a good target for the design of specific herbicides or antibiotics.

Results
The structure of Arabidopsis thaliana MTR kinase co-crystallized with ATPγS and MTR has been determined at 1.9 Å resolution. The structure is similar to B. subtilis MTR kinase and has the same protein kinase fold observed in other evolutionarily related protein kinase-like phosphotransferases. The active site is comparable between the two enzymes with the DXE-motif coordinating the nucleotide-Mg, the D238 of the HGD catalytic loop polarizing the MTR O1 oxygen, and the RR-motif interacting with the substrate MTR. Unlike its bacterial homolog, however, the Gly-rich loop (G-loop) of A. thaliana MTR kinase has an extended conformation, which shields most of the active site from solvent, a feature that resembles eukaryotic protein kinases more than the bacterial enzyme. The G- and W-loops of A. thaliana and B. subtilis MTR kinase adopt different conformations despite high sequence similarity. The ATPγS analog was hydrolyzed during the co-crystallization procedure, resulting in ADP in the active site. This suggests that the A. thaliana enzyme, like its bacterial homolog, may have significant ATPase activity in the absence of MTR.

Conclusion
The structure of A. thaliana MTR kinase provides a template for structure-based design of agrochemicals, particularly herbicides whose effectiveness could be regulated by nutrient levels. Features of the MTR binding site offer an opportunity for a simple organic salt of an MTR analog to specifically inhibit MTR kinase.
The risk for bloodstream infections is associated with increased parenteral caloric intake in patients receiving parenteral nutrition
Authors: Dissanaike Sharmila , Shelton Marilyn , Warner Keir , O'Keefe Grant E 
Published: October 2007

Abstract
Background
Patients receiving total parenteral nutrition (TPN) are at high risk for bloodstream infections (BSI). The notion that intravenous calories and glucose lead to hyperglycemia, which in turn contributes to BSI risk, is widely held but is unproven. We therefore sought to determine the role that hyperglycemia and parenteral calories play in the development of BSI in hospitalized patients receiving TPN.

Methods
Two hundred consecutive patients initiated on TPN between June 2004 and August 2005 were prospectively studied. Information was collected on patient age, sex, admission diagnosis, baseline laboratory values, intensive care unit (ICU) status and indication for TPN. Patients in the ICU were managed with strict glycemic control, whereas control on the general ward was more liberal. The maximum blood glucose level over each 8-hour period was recorded, as were parenteral daily intake, enteral daily intake and total daily caloric intake. The primary outcome measure was the incidence of BSI. Additional endpoints were ICU length of stay, hospital length of stay and mortality.

Results
A total of 78 patients (39%) developed at least one BSI, which were more common in ICU patients than in other hospitalized patients (60/122 patients versus 18/78 patients; P < 0.001). Maximum daily blood glucose concentrations were similar in patients with BSI and in patients without BSI (197 mg/dl versus 196 mg/dl, respectively). Patients with BSI received more calories parenterally than patients without BSI (36 kcal/kg/day versus 31 kcal/kg/day, P = 0.003). Increased maximum parenteral calories, increased average parenteral calories, and treatment in the ICU were strong risk factors for developing BSI. There was no difference in mortality between patients with and without BSI.

Conclusion
Increased parenteral caloric intake is an independent risk factor for BSI in patients receiving TPN. This association appears unrelated to hyperglycemia. Based upon our observations, we suggest that parenteral caloric intake be prescribed and adjusted judiciously with care taken to account for all intravenous caloric sources and to avoid even short periods of increased intake.
High resolution wavenumber standards for the infrared (Technical Report)
Authors: Guelachvili G. , Birk M. , Bordé Ch. J. , Brault J. W. , Brown L. R. , Carli B. , Cole A. R. H. , Evenson K. M. , Fayt A. , Hausamann D. , Johns J. W. C. , Kauppinen J. , Kou Q. , Maki A. G. , Rao K. Narahari , Toth R. A. , Urban W. , Valentin A. , Verges J. , Wagner G. , Wappelhorst M. H. , Wells J. S. , Winnewisser B. P. , Winnewisser M. 
Published: October 2007

Abstract
Chlorine - An Introduction
Authors: Porter George 
Published: October 2007

Abstract
Chlorine, in the form of its salts, has been known since the earliest days of recorded history, although its recognition as an element did not occur until the beginning of the nineteenth century when its very high reactivity as an oxidant was found remarkable after it was shown not to contain any oxygen. Its absorption by sunlight made it a key substance in the early development of photochemistry. One example of this, with both pure and applied aspects, is described in more detail. The free radical chloric oxide played an important role in the development of the technique of flash photolysis and twenty five years later these researches were of essential importance in showing how chlorine and its oxides were involved in the destruction of the ozone layer by the chlorofluorocarbons.
The Chlorine Industry
Authors: Fauvarque Jacqueline 
Published: October 2007

Abstract
Numerous products, such as polymers, chemicals or pharmaceuticals and ultra-pure metals, which often do not actually contain chlorine, are produced using either chlorine or its derivatives. They are essential in all industrial sectors and in our daily lives. New chlorine production units have adopted the membrane electrolytic process, but the century-old diaphragm and mercury processes retain their high-performance characteristics when appropriately modernised and improved.
Persistent, Ecotoxic and Bioaccumulative Compounds and their Possible Environmental Effects
Authors: Ballschmiter K. 
Published: October 2007

Abstract
The relationship between physicochemical properties, environmental distribution and effects of organochlorine compounds as a major class of persistent organic pollutants (POPs) are discussed. The environmental fate of a compound includes its transport and dispersion in the environment as well as its accumulation and transformation in defined environmental compartments. Accumulation and transformation as the result of environmental distribution may have long-term consequences; this is indicated by the ultimate accumulation and long-term bioactivity of several widely spread organochlorines, and is clearly evident in the decomposition of chlorofluorocarbons in the stratosphere.
Depending on the order of trophic levelsbiomagnifiaction factors of 10,000 up to 100,000 are encountered for persistentsemivolatile organochlorines such as 4,4'-DDE, PCB congeners or some Toxapheneconstituents. Mammals show intra-species pollutant transfer during thelactation period. While the mother animal is partly depleting its bodyburden, the calve accumulates in a critical period of its life via themilk a concentrated input of persistent organochlorines. A similar depletionphenomenon is also found for fish and crustacean which enrich in the eggsa substantial part of the accumulated body burden of the female.
The air skimming of semivolatiles by plantsurfaces leads to surprisingly high levels of pollutants in the uppersoil layers of forests that otherwise would be considered pristine interms of human activities.
Toxicology of Environmentally Persistent Chlorinated Organic Compounds
Authors: Hanberg Annika 
Published: October 2007

Abstract
The chlorinated organic compounds comprise a large group of compounds with a complex diversity of biologic effects and mechanisms of action. Based on the persistence and high toxicity of dioxins, PCBs, and DDT, this chapter focuses primarily on the toxicology of these organochlorine compounds. Not even these groups of compounds can be regarded as homogenous since the individual congeners show diverse environmental fates and toxicities. In this chapter, we will consider primarily the critical effects suspected to occur at human exposure at background levels, i.e. cancer, and effects on reproduction, neurobehaviour and the immune system. In recent years, interactions between these compounds and hormonal systems have received increasing attention. They have also been shown to be particularly toxic to the developing embryo, fetus and infant. In order to conduct accurate risk assessment, there is a need for further mechanistical data, and additional epidemiological studies, especially with regard to effects on reproductive, neurobehavioural and immune systems. The data presently available suggest that such effects already occur in the human population and thus, in order to reduce the exposure to these compounds, further release into the environment should be prevented.
Organochlorine Waste Management
Authors: Papp Roger 
Published: October 2007

Abstract
Sound environmental management includes the proper management of waste. This chapter reviews the basic rules of good management practice illustrated by some examples from chlorine derivatives production and gives the main considerations governing the Best Available Techniques for organochlorine waste thermal treatment. A review of the main degradation pathways of organochlorines - dispersal, distribution, degradation pathways, and environmental half-lives - demonstrates a very large range of characteristics, justifying the need for a separate study for each substance. Finally, the paper examines the latest developments in organochlorine contaminated site remediation technology.
Isolation of hematopoietic progenitors. An approach to two different immunomagnetic methods at the lab scale
Authors: Cancelas J. A. , Querol S. , Martín-Henao G. , Canals C. , Azqueta C. , Petriz J. , Inglés-Esteve J. , Amill B. , García J. 
Published: October 2007

Abstract
Structure and function of the potassium channel inhibitor from black scorpion venom
Authors: Grishin E. V. , Korolkova Yu. V. , Kozlov S. A. , Lipkin A. V. , Nosyreva E. D. , Pluzhnikov K. A. , Sukhanov S. V. , Volkova T. M. 
Published: October 2007

Abstract
Developing a general strategy for the solid supported synthesis of heterocycles: Applications to the generation of molecular diversity and drug discovery
Authors: Nuss J. M. , Desai M. C. , Zuckermann R. N. , Singh R. , Renhowe P. A. , Goff D. A. , Chinn J. P. , Wang L. , Dorr Hilary , Brown E. G. , Subramanian S. 
Published: October 2007

Abstract
Stereoselective cycloaddition reactions of carbohydrate derivatives
Authors: Herczegh Pál , Kovács Imre , Erdösi Gyöngyi , Varga T. , Agócs Atilla , Szilágyi L. , Sztaricskai F. , Berecibar Amaya , Lukacs Gabor , Olesker A. 
Published: October 2007

Abstract
Total synthesis of non-natural compounds for molecular recognition. The double challenge
Authors: de Mendoza J. , Alcázar Victoria , Botana Enrique , Galán A. , Lu Guoyuan , Magrans J. O. , Martín-Portugués Marta , Prados P. , Salmerón A. , Sánchez-Quesada J. , Seel C. , Segura M. 
Published: October 2007

Abstract
Notations and conventions in molecular spectroscopy: Part 1. General spectroscopic notation (IUPAC Recommendations 1997)
Authors: Schutte C. J. H. , Bertie J. E. , Bunker P. R. , Hougen J. T. , Mills I. M. , Watson J. K. G. , Winnewisser B. P. 
Published: October 2007

Abstract
Notations and conventions in molecular spectroscopy: Part 3. Permutation and permutation-inversion symmetry notation (IUPAC Recommendations 1997)
Authors: Bunker P. R. , Schutte C. J. H. , Hougen J. T. , Mills I. M. , Watson J. K. G. , Winnewisser B. P. 
Published: October 2007

Abstract
Carotenoid levels in human lymphocytes, measured by Raman microspectroscopy
Authors: Ramanauskaite R. B. , Segers-Nolten I. G. M. J. , de Grauw K. J. , Sijtsema N. M. , van der Maas L. , Greve Jan , Otto C. , Figdor C. G. 
Published: October 2007

Abstract
Redesigning nucleic acids
Authors: Benner S. A. , Battersby T. R. , Eschgfäller Bernd , Hutter Daniel , Kodra J. T. , Lutz Stefan , Arslan Tuncer , Bäschlin D. K. , Blättler M. , Egli Martin , Hammer Christophe , Held H. A. , Horlacher Jennifer , Huang Zh. , Hyrup Birgitte , Jenny T. F. , Jurczyk S. C. , König H. A. , von Krosigk U. , Lutz M. J. , MacPherson L. J. , Moroney S. E. , Müller E. , Nambiar K. P. , Piccirilli J. A. , Switzer C. Y. , Vögel J. J. , Richert C. , Roughton A. L. , Schmidt J. , Schneider K. C. , Stackhouse J. 
Published: October 2007

Abstract
Sugar mimics from sugar lactones
Authors: Fleet G. W. J. , Estevez J. C. , Smith M. D. , Blériot Y. , la Fuente C. , Krülle T. M. , Besra G. S. , Brennan P. J. , Nash R. J. , Johnson L. N. , Oikonomakos N. G. , Stalmans W. 
Published: October 2007

Abstract
An overview on the solution thermodynamics of lower rim functionalised calixarene derivatives and metal cations. New derivatives containing amino and thioalkyl functional groups
Authors: Namor A. F. D. , Hutcherson R. G. , Velarde F. J. S. , Zapata-Ormachea M. L. , Salazar L. E. P. , Jammaz Ibrahim , Rawi N. 
Published: October 2007

Abstract
Iron porphyrins reinvistigated by new method: Mössbauer spectroscopy using synchrotron radiation
Authors: Trautwein A. X. , Winkler H. , Schwendy S. , Grünsteudel H. , Meyer-Klaucke W. , Leupold O. , Rüter H. D. , Gerdau E. , Haas M. , Realo E. , Mandon D. , Weiss R. 
Published: October 2007

Abstract
Creating regular arrangements of nucleobases through metal ion coordination and H bond formation
Authors: Lippert B. , Amo-Ochoa Pilar , Brüning W. , Freisinger Eva , Lüth M.-S. , Meier S. , Meiser Cordula , Metzger S. , Rauter H. , Schreiber A. , Sigel R. K. O. , Witkowski H. 
Published: October 2007

Abstract