bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mutations in the signature motif in MutS affect ATP‐induced clamp formation and mismatch repair
Authors: Acharya Samir 
Published: July 2008

SummaryMutS protein dimer recognizes and co‐ordinates repair of DNA mismatches. Mismatch recognition by the N‐terminal mismatch recognition domain and subsequent downstream signalling by MutS appear coupled to the C‐terminal ATP catalytic site, Walker box, through nucleotide‐mediated conformational transitions. Details of this co‐ordination are not understood. The focus of this study is a conserved loop in Escherichia coli MutS that is predicted to mediate cross‐talk between the two ATP catalytic sites in MutS homodimer. Mutagenesis was employed to assess the role of this loop in regulating MutS function. All mutants displayed mismatch repair defects in vivo. Biochemical characterization further revealed defects in ATP binding, ATP hydrolysis as well as effective mismatch recognition. The kinetics of initial burst of ATP hydrolysis was similar to wild type but the magnitude of the burst was reduced for the mutants. Given its proximity to the ATP bound in the opposing monomer in the crystal and its potential analogy with signature motif of ABC transporters, the results strongly suggest that the loop co‐ordinates ATP binding/hydrolysis in trans by the two catalytic sites. Importantly, our data reveal that the loop plays a direct role in co‐ordinating conformational changes involved in long‐range communication between Walker box and mismatch recognition domains.
Sedimentology, petrography and geochemistry of a limestone breccia (Pietra di Billiemi) from north‐west Sicily, Italy: implications for evolution of the Tethyan basins around the Triassic/Jurassic boundary
Authors: SCOPELLITI GIOVANNA , NERI RODOLFO , BELLANCA ADRIANA , DI STEFANO PIETRO , BARBIERI MARIO 
Published: July 2008

AbstractIn this study, the Pietra di Billiemi, a famous dimension stone, is investigated because it records the tectonic evolution of the south Tethys continental margin and preserves a record of major environmental changes occurring near the Triassic/Jurassic boundary. The Pietra di Billiemi is a grey, coarse‐grained and clast‐supported limestone breccia cropping out in an area of the Palermo Mountains representing a segment of the Apennine–Maghrebian chain in western Sicily. The rock consists of metre‐sized to centimetre‐sized angular clasts, derived from Upper Triassic sponge boundstones and rudstones, with a differently coloured, silt‐grained matrix. Fitted fragments are observed commonly which suggest an in situ origin for the bulk of the breccia. The matrix is characterized by the absence of biogenic components and by variable mineralogy and geochemistry. Petrographic features and Sr‐isotope values indicate that the most important and earliest fillings of the breccia consist of black matrix and white matrix temporally referable to Hettangian–Sinemurian times. Clotted micrite, carbonate fluorapatite and abundant pyrite, in addition to relatively high contents of redox‐sensitive elements (V, Ni, Zn and S), are consistent with deposition in anoxic conditions that favoured microbial mediation for authigenic carbonate (calcite and dolomite) precipitation in the matrix. As a whole, the Billiemi breccia can be considered a product of tectonic fragmentation of a Tethyan carbonate platform edge around the Triassic/Jurassic boundary, formed when the drowned platform edge was covered by hemipelagic mudstones recording the anoxic conditions existing during Early Jurassic times.
Comparative Bone Histology of Adult Horses (Equus caballus) and Cows (Bos taurus)
Authors: Zedda M. , Lepore G. , Manca P. , Chisu V. , Farina V. 
Published: July 2008

SummaryBone microstructure of domestic herbivores is still not completely understood. Indeed, works focused on the bone histology of numerous Mammalian species frequently led to misunderstandings because of the high number of variations such as the kind of bone, section orientation, species, breed and age. Moreover, attempts to identify the species in archaeozoological studies by a mere qualitative approach have not been encouraging and in recent years quantitative methods, based on image processing and statistical analysis, have appeared. The present study was undertaken to determine whether morphometrical and morphological differences exist in the compact bone structure of the femur and humerus between horses and cows. Measurements such as area, perimeter, minimum and maximum diameter of osteons and Haversian canals as well as the osteonal density were carried out on cross sections of eight humeri and eight femurs of the two herbivores investigated. In agreement with other authors, the qualitative investigation confirmed that the compact bone of horses and cows can be classified as dense Haversian tissue. Osteons of the horse were more numerous and composed of a higher number of well‐defined lamellae when compared with the cow. Diameter, perimeter and area of osteons and Haversian canals were always higher in horses than in cows and this pattern could be related to the different locomotor behaviour of these animals.
Textilien mit antimykotischen und antibakteriellen Eigenschaften
Authors: Hipler U. C. 
Published: July 2008

ZusammenfassungAuf der Basis des ZIMMER Lyocell Verfahrens erfolgt die Herstellung von SeaCell® und SeaCell® Active Fasern. Eine besondere Fähigkeit der SeaCell® Faser ist, Stoffe zu binden und zu absorbieren. Die spezielle Fähigkeit der Metallsorption wird bei der Aktivierung von SeaCell® Fasern ausgenutzt. Dabei kann das bakterizid wirkende Metall Silber vom bereits fertig ausgeformten cellulosischen Faserkörper absorbiert werden. Die vorliegende Studie zeigt die antimykotische Wirkung von SeaCell®Active in einem In‐vitro‐Testsystem gegenüber Candida albicans (DSM 11225), Candida tropicalis (ATCC 1169) und Candida krusei (ATCC 6258). Darüber hinaus wurde die antibakterielle Aktivität der Fasern mit unterschiedlichen Mengen an SeaCell® Active dosisabhängig gegenüber Staphylococcus aureus (ATCC 22923) und Escherichia coli (ATCC 35218) nachgewiesen. Ob diese Faser in bioaktiven Textilien Verwendung finden kann, die für spezifische anatomische Regionen und Hautbedingungen mit einer Suszeptibilität für Pilz‐und Bakterieninfektionen, speziell Candida‐Spezies, Staphylococcus aureus und Escherichia coli geeignet ist, muss durch weitere Untersuchungen, insbesondere in‐vivo‐Tests am Menschen, unter Berücksichtigung möglicher allergischer und toxischer Effekte der Fasern, sichergestellt werden.
Lungenembolie durch Aspergillose (sog. Pilzembolie) Pulmonary embolism by aspergillosis (so called fungal embolism)
Authors: Schwesinger G. , Eckel L. , Wollert H.‐G. 
Published: July 2008

ZusammenfassungEin 71jähriger Mann entwickelte bei einem Zustand nach Schrittmacherimplantation bei Arrhythmie und Mehrfachrevisionen wegen Schrittmachertascheninfektionen einen Tumor im rechten Ventrikel. Notfallmäßiger Trikuspidalklappenersatz durch ein Carpentier Edwards Xenograft. Die Schrittmachersonden und das Endokard waren durch Aspergillus in Gestalt eines Aspergilloms infiziert. Durch dieses Material kam es zu einer Lungenembolie, was relativ selten ist.
Fall‐Bericht: Analyse der kritischen Zeitverzögerungen vom Fieberanstieg bis zur ersten Antimykotika‐Gabe bei der Diagnostik einer Candidämie
Authors: Kappe Reinhard , Fuchs Erika , Gorges Alexander , Rimek Dagmar 
Published: July 2008

ZusammenfassungIn einem Schwerpunkt‐Klinikum mit eigenem mikrobiologischen Labor wurde bei einer 84‐jährigen Patientin mit Candidämie die Zeitdauer der einzelnen diagnostischen Schritte vom Fieberbeginn bis zur Verabreichung der ersten Antimykotika‐Dosis bestimmt. Die Gesamtdauer betrug 25 Stunden und zehn Minuten. Die größte Verzögerung von acht Stunden lag zwischen dem positiven Signal der Blutkultur in der Nacht und dem Beginn der Verarbeitung der Blutkultur frühmorgens. Beschleunigungen erscheinen sowohl im klinischen als auch im labormedizinischen Bereich erreichbar durch Optimierung von Präanalytik, Analytik und Postanalytik.
Mapping of rhizoctonia root rot resistance genes in sugar beet using pathogen response‐related sequences as molecular markers
Authors: Lein J. C. , Sagstetter C. M. , Schulte D. , Thurau T. , Varrelmann M. , Saal B. , Koch G. , Borchardt D. C. , Jung C. 
Published: July 2008

AbstractRhizoctonia root and crown rot caused by the fungus Rhizoctonia solani is a serious disease of sugar beet. An F2:3 population from a cross between a resistant and a susceptible parent has been tested for R. solani resistance and a genetic map has been constructed from the corresponding F2 parents. The map encompasses 38 expressed sequence tags (ESTs) with high similarity to genes which are involved in resistance reactions of plants (R‐ESTs) and 25 bacterial artificial chromosomes (BACs) containing nucleotide binding site (NBS)‐motifs typical for disease resistance genes. Three quantitative trait loci (QTL) for R. solani resistance were found on chromosomes 4, 5 and 7 collectively explaining 71% of the total phenotypic variation. A number of R‐ESTs were mapped in close distance to the R. solani resistance QTL. In contrast, the NBS‐BACs mapped to chromosomes 1, 3, 7 and 9 with two major clusters of NBS‐BACs on chromosome 3. No linkage between NBS‐BACs and R. solani resistance QTL was found. The data are discussed with regard to using R‐ESTs and NBS markers for mapping quantitative disease resistances.
Cryo‐scanning Electron Microscopy Discloses Differences in Dehydration of Frozen Boar Semen Stored in Large Containers
Authors: Ekwall H 
Published: July 2008

ContentsIn general, freezing in flat plastic polyethylene terephthalate (PET) bags (FlatPacks) at 50°C/min gives better post‐thaw viability, in terms of sperm motility and membrane integrity, than does freezing in plastic maxi‐straws, probably owing to differences in cryobiology. To test the hypothesis that this better survival post‐thaw relates to the degree of sperm dehydration during freezing, the present study investigated the structure of boar semen in a frozen state using cryo‐scanning electron microscopy (cryo‐SEM) to compare two different packages (FlatPacks and maxi‐straws) for single artificial insemination (AI) doses, and three different freezing rates. The semen was split‐sample frozen in maxi‐straws or FlatPacks (both holding 5 ml) using 3% glycerol as cryoprotectant. Three freezing rates were applied from −5°C to −100°C, namely 2°C/min, 50°C/min and 1200°C/min, the lattermost by plunging the samples into liquid nitrogen (LN2). The samples were thereafter fractured into LN2 and larger areas of extra‐cellular, unbound frozen water (‘ice lakes’) were measured to determine the degree of dehydration of the spermatozoa. These areas decreased in size with an increase in cooling rate, the differences in size being more dramatic for maxi‐straws than for FlatPacks. Size of ice lakes was also influenced by location within package in relation to cooling rate, the central values being always smaller in maxi‐straws than in Flatpacks (p < 0.05 at 2°C/min and 50°C/min) but not at 1200°C/min, which suggested the FlatPack allows for more homogenous freezing of boar semen.
ELECTROPHYSIOLOGICAL EFFECTS OF KETAMINE ON HUMAN ATRIAL MYOCYTES AT THERAPEUTICALLY RELEVANT CONCENTRATIONS
Authors: Deng Chun‐Yu , Yu Xi‐Yong , Kuang Su‐Juan , Rao Fang , Yang Min , Shan Zhi‐Xin , Qian Wei‐Min , Zhou Zhi‐Ling , Lin Qiu‐Xiong , Wu Shu‐Lin , Zhang You‐Yi , Lin Shu‐Guang 
Published: July 2008

SUMMARY

Ketamine is widely used for the induction of anaesthesia in high‐risk patients with cardiovascular instability or severe hypovolaemia. However, the ionic mechanisms involved in the effects of ketamine at therapeutically relevant concentrations in human cardiac myocytes are unclear. The present study was designed to investigate the effects of ketamine on L‐type Ca2+ (ICa), transient outward K+ (Ito), ultra‐rapid delayed rectifier K+ (IKur) and inward rectifier potassium (IK1) currents, as well as on action potentials, in human isolated atrial myocytes.
Atrial myocytes were isolated enzymatically from specimens of human atrial appendage obtained from patients undergoing coronary artery bypass grafting. The action potential and membrane currents were recorded in both current‐ and voltage‐clamp modes using the patch‐clamp technique.
Ketamine inhibited ICa with an IC50 of 1.8 µmol/L. In addition, 10 µmol/L ketamine decreased the ICa peak current at +10 mV from 5.1 ± 0.3 to 2.1 ± 0.4 pA/pF (P < 0.01), but did not change the threshold potential, peak current potential and reverse potential.
Ketamine had no effect on Ito, IKur or IK1, but it reversibly shortened the duration of the action potential in human atrial myocytes.
In conclusion, ketamine, at a clinically relevant concentration, shortens the action potential duration of the human atrial myocytes, probably by inhibiting ICa.
DOES MODERATE PRETERM BIRTH LEAD TO ALTERED ARTERIAL PRESSURE? STUDIES IN SHEEP
Authors: De Matteo Robert , Stacy Victoria , Probyn Megan E , Brew Nadine , Blasch Natasha , Harding Richard 
Published: July 2008

SUMMARY

Low birth weight (LBW) is associated with an increased risk of cardiovascular disease. Preterm birth is a major determinant of LBW and has been shown to result in elevated arterial pressure (AP) in humans, but few studies have investigated the effects of preterm birth in the absence of potentially confounding factors. Our aim was to determine whether moderately preterm birth per se alters the postnatal development of AP in lambs.
Preterm lambs were delivered approximately 14 days before term (i.e. ~133 days of gestation); controls were born at term (~147 days). Mean arterial pressure (MAP), heart rate (HR), blood composition and indices of growth were measured at 4 and 8 weeks post term‐equivalent age (PTEA). We also studied a separate cohort of preterm and term sheep as young adults (~1.1 years).
Preterm lambs had significantly lower birth weights than term lambs, but bodyweights were not significantly different by Day 12 PTEA. In addition, MAP, HR and most blood variables did not differ between term and preterm lambs at 4 or 8 weeks PTEA. Preterm birth per se did not alter MAP or HR in young adult sheep.
Low birth weight due to preterm birth does not result in an altered AP during early postnatal life or at maturity. Moderate intrauterine growth restriction (IUGR) due to twinning, which further reduces birth weight, does not affect MAP in preterm lambs. Other factors, such as the degree of prematurity or IUGR, exposure to corticosteroids or postnatal nutrition, may be important in the later development of elevated AP.
COMPARATIVE PROTEIN BINDING, STABILITY AND DEGRADATION OF SATRAPLATIN, JM118 AND CISPLATIN IN HUMAN PLASMA IN VITRO
Authors: Bell Deanna N , Liu Johnson J , Tingle Malcolm D , Rattel Benno , Meyer Thorsten Ulf , McKeage Mark J 
Published: July 2008

SUMMARY

Satraplatin is an investigational orally administered platinum‐based antitumour drug. The present study compared the plasma protein binding, stability and degradation of satraplatin with that of its active metabolite JM118 and cisplatin.
The platinum complexes were incubated in human plasma for up to 2 h at 37°C and quantified in plasma fractions by inductively coupled plasma–mass spectrometry on‐ or off‐line to high‐performance liquid chromatography.
All three platinum drugs became irreversibly bound to plasma proteins and showed negligible reversible protein binding. They were also unstable in plasma and generated one or more platinum‐containing degradation products during their incubation. However, the three platinum complexes differed in the kinetics of their instability and protein binding, as well as in the number of degradation products formed during their incubation.
In conclusion, the plasma protein binding, instability and degradation of satraplatin and its active metabolite JM118 are qualitatively similar to that of cisplatin and other clinically approved platinum‐based drugs. Quantitative differences in their irreversible protein binding and degradation were related to their respective physiochemical properties and bioactivation mechanisms.
SPATIAL AND TEMPORAL ASPECTS OF cAMP SIGNALLING IN CARDIAC MYOCYTES
Authors: Iancu Radu V , Ramamurthy Gopalakrishnan , Harvey Robert D 
Published: July 2008

SUMMARY

β1‐Adrenoceptor and M2 muscarinic receptor regulation of cAMP production plays a pivotal role in autonomic regulation of cardiac myocyte function. However, not all responses are easily explained by a uniform increase or decrease in cAMP activity throughout the entire cell.
Adenovirus expression of fluorescence resonance energy transfer (FRET)‐based biosensors can be used to monitor cAMP activity in protein kinase A (PKA) signalling domains, as well as the bulk cytoplasmic domain of intact adult cardiac myocytes.
Data obtained using FRET‐based biosensors expressed in different cellular microdomains have been used to develop a computational model of compartmentalized cAMP signalling.
A systems biology approach that uses quantitative computational modelling together with experimental data obtained using FRET‐based biosensors has been used to provide evidence for the idea that compartmentation of cAMP signalling is necessary to explain the stimulatory responses to β1‐adrenoceptor activation as well as the complex temporal responses to M2 muscarinic receptor activation.
Serotoninergic modulation of sensory transmission to brainstem reticulospinal cells
Authors: Antri Myriam , Auclair François , Albrecht Jonathan , Djeudjang Nsima , Dubuc Réjean 
Published: August 2008

AbstractSensory inputs are subjected to modulation by central neural networks involved in controlling movements. It has been shown that serotonin (5‐HT) modulates sensory transmission. This study examines in lampreys the effects of 5‐HT on sensory transmission to brainstem reticulospinal (RS) neurons and the distribution of 5‐HT cells that innervate RS cells. Cells were recorded intracellularly in the in vitro isolated brainstem of larval lampreys. Trigeminal nerve stimulation elicited disynaptic excitatory responses in RS neurons, and bath application of 5‐HT reduced the response amplitude with maximum effect at 10 μm. Local ejection of 5‐HT either onto the RS cells or onto the relay cells decreased sensory‐evoked excitatory postsynaptic potentials (EPSPs) in RS cells. The monosynaptic EPSPs elicited from stimulation of the relay cells were also reduced by 5‐HT. The reduction was maintained after blocking either N‐methyl‐d‐aspartate (NMDA) or α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA) receptors. The local ejection of glutamate over RS cells elicited excitatory responses that were only slightly depressed by 5‐HT. In addition, 5‐HT increased the threshold for eliciting sustained depolarizations in response to trigeminal nerve stimulation but did not prevent them. Combined 5‐HT immunofluorescence with axonal tracing revealed that the 5‐HT innervation of RS neurons of the middle rhombencephalic reticular nucleus comes mainly from neurons in the isthmic region, but also from neurons located in the pretectum and caudal rhombencephalon. Our results indicate that 5‐HT modulates sensory transmission to lamprey brainstem RS cells.
Decrease of D2 receptor binding but increase in D2‐stimulated G‐protein activation, dopamine transporter binding and behavioural sensitization in brains of mice treated with a chronic escalating dose ‘binge’ cocaine administration paradigm
Authors: Bailey A. , Metaxas A. , Yoo J. H. , McGee T. , Kitchen I. 
Published: July 2008

AbstractUnderstanding the neurobiology of the transition from initial drug use to excessive drug use has been a challenge in drug addiction. We examined the effect of chronic ‘binge’ escalating dose cocaine administration, which mimics human compulsive drug use, on behavioural responses and the dopaminergic system of mice and compared it with a chronic steady dose (3 × 15 mg/kg/day) ‘binge’ cocaine administration paradigm. Male C57BL/6J mice were injected with saline or cocaine in an escalating dose paradigm for 14 days. Locomotor and stereotypy activity were measured and quantitative autoradiographic mapping of D1 and D2 receptors, dopamine transporters and D2‐stimulated [35S]GTPγS binding was performed in the brains of mice treated with this escalating and steady dose paradigm. An initial sensitization to the locomotor effects of cocaine followed by a dose‐dependent increase in the duration of the locomotor effect of cocaine was observed in the escalating but not the steady dose paradigm. Sensitization to the stereotypy effect of cocaine and an increase in cocaine‐induced stereotypy score was observed from 3 × 20 to 3 × 25 mg/kg/day cocaine. There was a significant decrease in D2 receptor density, but an increase in D2‐stimulated G‐protein activity and dopamine transporter density in the striatum of cocaine‐treated mice, which was not observed in our steady dose paradigm. Our results document that chronic ‘binge’ escalating dose cocaine treatment triggers profound behavioural and neurochemical changes in the dopaminergic system, which might underlie the transition from drug use to compulsive drug use associated with addiction, which is a process of escalation.
Short‐acting insulin analogues vs. regular human insulin in type 2 diabetes: a meta‐analysis
Authors: Mannucci E. , Monami M. , Marchionni N. 
Published: July 2008

Aim:  Short‐acting insulin analogues, in comparison with regular human insulin (HRI), provide a greater control of postprandial glucose, while their superiority on haemoglobin A1c (HbA1c) is controversial.Method:  All randomized controlled trials (RCTs) with a duration >4 weeks comparing short‐acting insulin analogues (lispro, aspart or glulisine) with HRI in type 2 diabetic patients were retrieved; data on HbA1c and postprandial glucose et end‐point and incidence of severe hypoglycaemia were extracted and meta‐analysed.Results:  A total of 13 RCTs (7, 4 and 2 with lispro, aspart and glulisine, respectively) were retrieved and included in the analysis. Short‐acting analogues reduced HbA1c by 0.4% (0.1–0.6%) (p = 0.027) in comparison with HRI. A significant improvement was observed also in self‐monitored 2 h postbreakfast and dinner blood glucose. The overall rate of severe hypoglycaemia was not significantly different with short‐acting analogues and HRI [Mantel–Haenszel odds ratio for 95% confidence interval 0.61 (0.25–1.45)].Conclusion:  In type 2 diabetic patients, short‐acting insulin analogues provide a better control of HbA1c and postprandial glucose than regular human insulin, without any significant reduction of the risk of severe hypoglycaemia.