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Selected AbstractsHistomorphometric assessment of bone turnover in uraemic patients: comparison between activation frequency and bone formation rateHISTOPATHOLOGY, Issue 6 2001P Ballanti Histomorphometric assessment of bone turnover in uraemic patients: comparison between activation frequency and bone formation rate Aims:,The histomorphometric assessment of bone formation rate (BFR/BS) in bone biopsies from uraemic patients is of crucial importance in differentiating low from high turnover types of renal osteodystrophy. However, since BFR/BS relies on osteoblasts, activation frequency (Ac.f), encompassing all remodelling phases, has recently been preferred to BFR/BS. This study was carried out to consider whether estimation of Ac.f is superior, in practical terms, to that of BFR/BS in distinguishing between different rates of bone turnover in uraemic patients. Methods and results:,Bone biopsies from 27 patients in predialysis (20 men and seven women; mean age 53 ± 12 years) and 37 in haemodialysis (22 men and 15 women; mean age 53 ± 12 years) were examined. The types of renal osteodystrophy were classified on the basis of morphology. Bone formation rate and Ac.f were evaluated according to standardized procedures. The Ac.f was calculated both as a ratio between BFR/BS and wall thickness (W.Th) and as a reciprocal of erosion, formation and quiescent periods (EP, FP and QP). Patients were affected by renal osteodystrophy with predominant hyperparathyroidism (two predialysis and 16 dialysis), predominant osteomalacia (three predialysis and seven dialysis) or that of advanced (nine predialysis and five dialysis) or mild (seven predialysis and four dialysis) mixed type or adynamic type (six predialysis and five dialysis). Activation frequency, which with either formula requires the measurement of W.Th, i.e. the thickness of bone structural units (BSUs), was not calculated in three dialysis patients with severe hyperparathyroidism and in one predialysis and four dialysis patients with severe osteomalacia, because only incomplete BSUs were found. In dialysis, EP was higher in the adynamic than in the other types of osteodystrophy. During both predialysis and dialysis, FP was higher in osteomalacia than in the other forms of osteodystrophy, and in adynamic osteopathy than in hyperparathyroidism or in advanced and mild mixed osteodystrophy. During predialysis and dialysis, QP was higher in the adynamic than in the other forms of osteodystrophy. Correlations were found between BFR/BS and Ac.f, during predialysis (r=0.97) and dialysis (r=0.95). Conclusions:,The superiority of Ac.f in assessing bone turnover, in comparison to BFR/BS, is conceptual rather than practical. The highest values for FP in osteomalacia and for QP in adynamic bone allow a clearer characterization of these low turnover conditions. [source] Recovery of Trabecular and Cortical Bone Turnover After Discontinuation of Risedronate and Alendronate Therapy in Ovariectomized RatsJOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2008Robyn K Fuchs Abstract Alendronate (ALN) and risedronate (RIS) are bisphosphonates effective in reducing bone loss and fractures associated with postmenopausal osteoporosis. However, it is uncertain how long it takes bone turnover to be re-established after treatment withdrawal, and whether this differs between the two drugs. The objective of this study was to determine the time required to re-establish normal bone turnover after the discontinuation of ALN and RIS treatment in an animal model of estrogen-deficiency osteoporosis. Two hundred ten, 6-mo-old female Sprague-Dawley rats were ovariectomized and 6 wk later were randomized into baseline controls (n = 10) and four treatment groups (n = 50/group): vehicle-treated controls (CON; 0.3 ml sterile water), ALN (2.4 ,g/kg), low-dose RIS (RIS low; 1.2 ,g/kg), and high-dose RIS (RIS high; 2.4 ,g/kg). Treatments were administered 3 times/wk by subcutaneous injection. Baseline controls were killed at the initiation of treatment. Other groups were treated for 8 wk, and subgroups (n = 10/ treatment group) were killed 0, 4, 8, 12, and 16 wk after treatment was withdrawn. Static and dynamic histological analyses were performed for cortical (tibial diaphysis) and trabecular (proximal tibia and L4 vertebrae) bone. DXA and mechanical testing was performed on the L5 vertebra. After 8 wk of treatment, trabecular bone turnover rates were significantly suppressed in all drug-treated animals. Trabecular bone formation rate (BFR/BS) remained significantly lower than vehicle in bisphosphonate-treated animals through 12 wk. Sixteen weeks after treatment withdrawal, trabecular BFR/BS in the proximal tibia was re-established in animals treated with RIS but not in animals treated with ALN compared with controls. BMD of the fifth lumbar vertebra remained significantly higher than controls 16 wk after treatment withdrawal in ALN-treated animals but not in RIS-treated animals. Despite reductions in BMD and increases in bone turnover, ultimate force of the fifth lumbar vertebra remained significantly higher in all drug-treated animals through 16 wk after withdrawal. [source] Exogenous PTH and Endogenous 1,25-Dihydroxyvitamin D Are Complementary in Inducing an Anabolic Effect on Bone,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2008Rana Samadfam Abstract PTH and 1,25(OH)2D each exert dual anabolic and catabolic skeletal effects. We assessed the potential interaction of PTH and 1,25(OH)2D in promoting skeletal anabolism by comparing the capacity of exogenous, intermittently injected PTH(1-34) to produce bone accrual in mice homozygous for the 1,(OH)ase-null allele [1,(OH)ase,/, mice] and in wildtype mice. In initial studies, 3-mo-old wildtype mice were either injected once daily (40 ,g/kg) or infused continuously (120 ,g/kg/d) with PTH(1,34) for up to 1 mo. Infused PTH reduced BMD, increased the bone resorption marker TRACP-5b, and raised serum calcium but did not increase serum 1,25(OH)2D. Injected PTH increased serum 1,25(OH)2D and BMD, raised the bone formation marker osteocalcin more than did infused PTH, and did not produce sustained hypercalcemia as did PTH infusion. In subsequent studies, 3-mo-old 1,(OH)ase,/, mice, raised on a rescue diet, and wildtype littermates were injected with PTH(1,34) (40 ,g/kg) either once daily or three times daily for 1 mo. In 1,(OH)ase,/, mice, baseline bone volume (BV/TV) and bone formation (BFR/BS) were lower than in wildtype mice. PTH administered intermittently increased BV/TV and BFR/BS in a dose-dependent manner, but the increases were always less than in wildtype mice. These studies show that exogenous PTH administered continuously resorbs bone without raising endogenous 1,25(OH)2D. Intermittently administered PTH can increase bone accrual in the absence of 1,25(OH)2D, but 1,25(OH)2D complements this PTH action. An increase in endogenous 1,25(OH)2D may therefore facilitate an optimal skeletal anabolic response to PTH and may be relevant to the development of improved therapeutics for enhancing skeletal anabolism. [source] Climbing Exercise Increases Bone Mass and Trabecular Bone Turnover Through Transient Regulation of Marrow Osteogenic and Osteoclastogenic Potentials in Mice,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2003Toshiharu Mori Abstract To investigate the relationship between the effects of bone turnover and bone marrow cell development in bone cells, we developed a mouse voluntary climbing exercise model. Climbing exercise increased bone volume and transient osteogenic potential of bone marrow. This model would be suitable for investigating the mechanistic roles of mechanical loading. Introduction: The relationship between bone mass gain and local bone formation and resorption in mechanically loaded bone is not well understood. Materials and Methods: Sixty-five C57BL/6J mice, 8 weeks of age, were assigned to five groups: a baseline control and two groups each of ground control and climbing exercise mice for 2 and 4 weeks. Mice were housed in a 100-cm tower and had to climb toward a bottle placed at the top to drink water. Results: Compared with the ground control, bone mineral density of the left femur increased in the climbing mice at 4 weeks. At 2 and 4 weeks, bone formation rate (BFR/BS) of periosteal surface, the cross-sectional area, and moment of inertia were increased in the climbing mice, whereas BFR/BS and eroded surface (ES/BS) of endosteal surface did not differ. The trabecular bone volume (BV/TV) of the proximal tibia increased in climbing mice, and osteoclast surface (Oc.S/BS) and osteoclast number decreased at 2 weeks. At 4 weeks, there were increases in BV/TV and parameters of bone formation, including mineralized surface, mineral apposition rate, and bone formation rate. In marrow cell cultures from the tibia, the number of alkaline phosphatase+ colony forming units-fibroblastic and the area of mineralized nodule formation in climbing mice were increased, and the number of osteoclast-like TRACP+ multinucleated cells was lower at 2 weeks. At 4 weeks, these parameters recovered to the levels of the ground controls. Conclusion: Our results indicate that climbing increased trabecular bone volume and reduced bone resorption, with a subsequent increase in bone formation. Intermittent climbing downregulates marrow osteoclastogenic cells and upregulates osteogenic cells initially, but further exercise seemed to desensitize them. Cortical envelopes were enlarged earlier, but the response seems to differ from trabecular bone. [source] Role of Inducible Nitric Oxide Synthase in Skeletal Adaptation to Acute Increases in Mechanical Loading,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2002Makoto Watanuki M.D. Abstract To clarify the role of nitric oxide (NO) in regulation of bone metabolism in response to skeletal loading, we examined inducible NO synthase (iNOS) gene knockout mice in the tail-suspension model. Histomorphometric analyses of proximal tibias revealed that 7 days of tail suspension decreased the bone volume (BV/TV) and bone formation rate (BFR/BS) and increased the osteoclast surface (Oc.S/BS) in mice with all iNOS genotypes. Both iNOS+/+ and iNOS+/, mice responded to subsequent 14-day reloading, with increases in BV/TV and BFR/BS and a decrease in Oc.S/BS, whereas these responses were abolished in iNOS,/, mice. The osteoblasts flattened after tail suspension appeared cuboidal during subsequent reloading. Immunoreactivity for iNOS was detected in these osteoblasts and osteocytes by immunohistochemistry. These defective responses after reloading were rescued in iNOS,/, mice by treatment with an NO donor nitroglycerine (NG). Conversely, the responses in iNOS+/+ mice were inhibited by treatment with an NOS inhibitor aminoguanidine (AG). In bone marrow cell cultures, mineralized nodules derived from iNOS,/, mice after reloading were significantly reduced. Taken together, our results suggest that NO generated by iNOS in osteoblasts plays a critical role in adjusting bone turnover and increasing osteogenic activity in response to the acute increase in mechanical loading after tail suspension. [source] Effect of isometric exercise and body scanning on cigarette cravings and withdrawal symptomsADDICTION, Issue 7 2009Michael Ussher ABSTRACT Aims To examine the acute effects of a guided relaxation routine (body scan) and isometric exercise on desire to smoke and tobacco withdrawal symptoms. Design Experimental comparison of three conditions. Participants Forty-eight individuals reporting smoking ,10 cigarettes daily. Intervention Random assignment to one of three interventions delivered via a 10-minute audio: isometric exercise (IE, n = 14), body scanning (BS, n = 18) or a reading about natural history (control group, n = 16). Interventions were delivered twice on the same day: in the laboratory, then in their ,normal' environment. Measurements Desire to smoke (primary outcome) and withdrawal symptoms were rated at pre-intervention and up to 30 minutes post-intervention. Findings Controlling for baseline scores, post-intervention desire to smoke and withdrawal symptoms were significantly lower for IE and BS groups, compared with the controls, in both environments. There were no significant differences for IE versus BS. For desire to smoke, controlling for baseline values, ratings in the laboratory were significantly lower for IE and BS versus the control up to 30 minutes post-intervention. In the normal environment, these ratings were significantly lower only up to 5 minutes post-intervention. Conclusions Brief IE and BS interventions are effective for reducing desire to smoke and withdrawal symptoms in temporarily abstaining smokers. These interventions were found to be more effective in the laboratory than in the smoker's normal environment, but this may be an artefact of there not being a sufficient ,wash-out' period between interventions. These techniques may be beneficial for managing desire to smoke and tobacco withdrawal. [source] DR JAMES H.S. SIMON, BS, DDS University of Southern California School of Dentistry California USAENDODONTIC TOPICS, Issue 1 2006Article first published online: 21 SEP 200 No abstract is available for this article. [source] High viral infection rates in Antarctic and Arctic bacterioplanktonENVIRONMENTAL MICROBIOLOGY, Issue 1 2007Christin Säwström Summary The frequency of visibly phage-infected bacterial cells (FVIB) and the average number of phages per cell [i.e. burst size (BS)] were determined in Antarctic and Arctic ultra-oligotrophic freshwater environments. Water samples were collected from two Antarctic freshwater lakes and cryoconite holes from a glacier in the Arctic. Data from this bipolar study show the highest FVIB (average 26.1%, range 5.1% to 66.7%) and the lowest BS (average 4, range 2,15) ever reported in the literature. The bacterial density is low in these ultra-oligotrophic freshwater environments but a large proportion of the bacteria are visibly infected. Our results suggest that a constant virioplankton population can be maintained in these extreme environments even though host density is low and often slow growing. [source] Generalized Birnbaum-Saunders distributions applied to air pollutant concentrationENVIRONMETRICS, Issue 3 2008Víctor Leiva Abstract The generalized Birnbaum-Saunders (GBS) distribution is a new class of positively skewed models with lighter and heavier tails than the traditional Birnbaum-Saunders (BS) distribution, which is largely applied to study lifetimes. However, the theoretical argument and the interesting properties of the GBS model have made its application possible beyond the lifetime analysis. The aim of this paper is to present the GBS distribution as a useful model for describing pollution data and deriving its positive and negative moments. Based on these moments, we develop estimation and goodness-of-fit methods. Also, some properties of the proposed estimators useful for developing asymptotic inference are presented. Finally, an application with real data from Environmental Sciences is given to illustrate the methodology developed. This example shows that the empirical fit of the GBS distribution to the data is very good. Thus, the GBS model is appropriate for describing air pollutant concentration data, which produces better results than the lognormal model when the administrative target is determined for abating air pollution. Copyright © 2007 John Wiley & Sons, Ltd. [source] VIQ-PIQ Discrepancies in Partial Epilepsy: On the Relation to Lat- eralities of Focal MRI Lesions, P3 Peaks, and Focal Spikes.EPILEPSIA, Issue 2000Osamu Kanazawa Purpose: A number of previous ncurophysiological studies have indicated that the glutamatergic system is important in the induction of epileptiform activity and the dcvelopment of epileptogenesis. Clutamate transport is the primary mechanism of inactivation of syiiaptically released glutamate. GLAST is classified BS an astrocytic transporter and occurs in high concentrations in the ccrebcllum. The pathophysiologic rolc of GLAST in epilepsy is not known in detail. To investigate the role of thc astroglial glutamatc transporter GLAST in epileptogenesis, we compared amygdalu-kindling and pentylenctetrazolc (PTZ) induced seizures in GLAST-deficient mice (GLAST(-/-)) wild-type mice (GLAST(+/+)), and maternal C57Black6/J mice (C57). Purpose: Subtest IQ such as verbal IQ (VIQ) and performance IQ (PIQ) in WAIS or WISC are thought to represent neuropsychological functions of the left and right hemispheres, respectively. The P300 (P3) event-related potential reflects cognitive processes. We do not ye1 know the brain site of P3 origin or how epileptogenic foci (EF) influ- ence P3 potentials. To examine neuropsychological influence by partial epilepsy (PE), we studied VIQ-PIQ discrepancies in PE in relation to lateralities of focal MRI lesions, P3 peaks, and EF. Methods: Thirteen patients showed VIQ-PIQ discrepancies significant at the p7lt;O.O5 level, represented by a>l2-point spread for the WAIS in adults, and a 15-point spread in the WISC in children. We evoked P3 potentials in the individuals with discrepant IQ differences by asking them to keep a mental count of rare tones, including introduction of oddbail tones. EEGs were recorded by the international 10,20 system and P3 peaks were shown in a topographical view by offline analysis. Patients were divided into normal and abnormal groups according to MRI findings, and were examined for the laterali- ties of the dominant side in subtest IQ (conventionally, we regarded higher VIQ as left hemisphere dominant and higher PIQ as right hemisphere dominant), P3 peaks, and EF. We did not correlate results with lert or right handedness. Results: Five patients (38.5%) were in the normal group and 8 patients (61.5%) were in the abnormal group. Concordance of the lateralities in P3 peaks and dominant side in subtest IQ was shown in 1 patient (20%) in the normal group and 5 patients (62.5%) in the abnormal group. In the normal group, all patients showed contralateral P3 peak shift to EF, and all except I patient showed contralateral P3 peak shift to the dominant side in subtest IQ. The other 3 patients in the abnormal group showed unilateral focal cortical dysplasias (FCD), ipsilateral P3 shift, and contralateral dominant side in subtest IQ to the focal MRI lesions. Conclusion: In our partial epilepsy series with VIQ-PIQ discrepancies, concordance of the lateralities in P3 peaks and dominant side in subtest IQ was shown in < half of the patients. Epileptogenic foci seem to have 3 different grades of influence on P3 peak shift and dominant side in subtest IQ according to the severities of accompanying focal MRI lesions: 1. Without MRI lesions, EF can make P3 peak shift contralaterally, but the dominant side in the subtest IQ shift ipsilaterally; 2. With less severe focal MRI lesions such as hippocampal atrophy etc., EF can make not only P3 peaks but also the dominant side in the subtest IQ shift contralaterally; 3. With severe focal MRI lesions such as FCD, EF can make the dominant side in the subtest IQ shift contralaterally, but the P3 peak may shift ipsilaterally. Epileptogenic foci without MRI lesions seem to control ipsilateral P3 potentials. MRI lesions render a hemisphere unlikely to become dominant, but epileptogenic foci can coexist with apparently normal neuropsychological function. [source] Exploiting the short,term and long,term channel properties in space and time: Eigenbeamforming concepts for the BS in WCDMAEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 5 2001Christopher Brunner The deployment of adaptive antennas at base stations considerably increases the spectral efficiency of wireless communication systems. To reduce the computational complexity and increase performance of space,time (ST) processing, processing may take place in reduced dimension, i. e., pre,filtering takes place which is related to linear estimation theory based on second order statistics. To this end, long,term and short,term channel estimates are integrated into specific Tx/Rx systems. In this article, we present a new ST rake structure for uplink reception in WCDMA which operates in reduced dimension. Accordingly, our approach combines short,term and long,term spatial and temporal channel properties using an eigenanalysis. By choosing dominant eigenbeams in time and space, the algorithm enhances interference suppression as well as spatial and temporal receive diversity. In contrast to previously introduced well,known receiver structures, the ST eigenrake inherently adapts to different propagation environments and achieves higher spectral efficiency than other receivers. This is illustrated by Monte,Carlo simulations. Then we extend the proposed concept to the downlink. The downlink eigenbeamformer improves closed,loop downlink diversity compared to other proposals in standardization (3GPP) which only exploit short,term channel properties. Even though the short,term feedback rate remains unchanged, additional antenna elements can be included to increase antenna and diversity gain. We also present a tracking solution to the downlink eigenbeamforming in WCDMA. To this end, we propose a distributed implementation of the eigenspace/,beam tracking at the mobile terminal and base station (BS), respectively. Moreover, the specific nature of the deployed tracking scheme offers an advantageous feedback signalling. [source] Isolation and structural characterization of the Ndh complex from mesophyll and bundle sheath chloroplasts of Zea maysFEBS JOURNAL, Issue 11 2005Costel C. Darie Complex I (NADH: ubiquinone oxidoreductase) is the first complex in the respiratory electron transport chain. Homologs of this complex exist in bacteria, mitochondria and chloroplasts. The minimal complex I from mitochondria and bacteria contains 14 different subunits grouped into three modules: membrane, connecting, and soluble subcomplexes. The complex I homolog (NADH dehydrogenase or Ndh complex) from chloroplasts from higher plants contains genes for two out of three modules: the membrane and connecting subcomplexes. However, there is not much information about the existence of the soluble subcomplex (which is the electron input device in bacterial complex I) in the composition of the Ndh complex. Furthermore, there are contrasting reports regarding the subunit composition of the Ndh complex and its molecular mass. By using blue native (BN)/PAGE and Tricine/PAGE or colorless-native (CN)/PAGE, BN/PAGE and Tricine/PAGE, combined with mass spectrometry, we attempted to obtain more information about the plastidal Ndh complex from maize (Zea mays). Using antibodies, we detected the expression of a new ndh gene (ndhE) in mesophyll (MS) and bundle sheath (BS) chloroplasts and in ethioplasts (ET). We determined the molecular mass of the Ndh complex (550 kDa) and observed that it splits into a 300 kDa membrane subcomplex (containing NdhE) and a 250 kDa subcomplex (containing NdhH, -J and -K). The Ndh complex forms dimers at 1000,1100 kDa in both MS and BS chloroplasts. Native/PAGE of the MS and BS chloroplasts allowed us to determine that the Ndh complex contains at least 14 different subunits. The native gel electrophoresis, western blotting and mass spectrometry allowed us to identify five of the Ndh subunits. We also provide a method that allows the purification of large amounts of Ndh complex for further structural, as well as functional studies. [source] Detailed determination of smoke gas contents using a small-scale controlled equivalence ratio tube furnace methodFIRE AND MATERIALS, Issue 8 2007Per Blomqvist Abstract A series of tests including seven different materials and products have been conducted using a controlled equivalence ratio tube furnace test method. The main objective of the tests was to determine yields of fire-generated products at defined combustion conditions. The tube furnace test method was set up and run in close agreement with that described in BS 7990:2003. At the time of experimental work the new tube furnace method was in the process of becoming an international standard. It was thus of interest to make an assessment of the capability of the method for determining production yields of important toxic fire products from different types of materials and products. The test series included solid wood, flexible polyurethane (PUR), fire-retarded rigid PUR, a polyvinyl chloride (PVC) carpet, a high-performance data cable with fluorine-containing polymer matrix, a PVC-based cable sheathing material and fire-retarded polyethylene cable insulation material. Duplicate tests were generally conducted at both well-ventilated and vitiated combustion conditions with these materials. The smoke gases produced from the combustion were quantified for inorganic gases by FTIR technique in all tests. A more detailed analysis of the smoke gases was conducted for some of the materials. This extended analysis contained a detailed assessment of organic compounds including, e.g. volatile organic compounds, isocyanates, aldehydes and polycyclic aromatic hydrocarbons. The analysis further included measurement of the size distribution of fire-generated particles for some of the materials. The quantification of toxic inorganic gases produced by combustion at both well-ventilated and vitiated conditions was successful regarding repeatability and stability. Typical yields for the two fire stages investigated were determined for a wide range of materials and products. The detailed analysis of organic compounds further corroborated that the new tube furnace method can replicate defined combustion conditions. Copyright © 2007 John Wiley & Sons, Ltd. [source] Amphibolite and blueschist,greenschist facies metamorphism, Blue Mountain inlier, eastern JamaicaGEOLOGICAL JOURNAL, Issue 5 2008Richard N. Abbott Jr Abstract Cretaceous (possibly older) metamorphic rock occurs mainly in the Blue Mountain inlier in eastern Jamaica. Fault-bounded blocks reveal two styles of metamorphism, Westphalia Schist (upper amphibolite facies) and Mt. Hibernia Schist (blueschist (BS),greenschist (GS) facies). Both Westphalia Schist and Mt. Hibernia Schist preserve detailed records of retrograde P,T paths. The paths are independent, but consistent with different parts of the type-Sanbagawa metamorphic facies series in Japan. For each path, phase relationships and estimated P,T conditions support a two-stage P,T history involving residence at depth, followed by rapid uplift and cooling. Conditions of residence vary depending on the level in a tectonic block. For the critical mineral reaction (isograd) in Westphalia Schist, conditions were P ,7.5,kbars, T ,600°C (upper amphibolite facies). Retrograde conditions in Hibernia Schist were P,=,2.6,3.0,kbars, T,=,219,237°C for a(H2O),=,0.8,1.0 (GS facies). Mt. Hibernia Schist may represent a volume of rock that was separated and uplifted at an early time from an otherwise protracted P,T path of the sort that produced the Westphalia Schist. Reset K,Ar ages for hornblende and biotite indicate only that retrograde metamorphism of Westphalia Schist took place prior to 76.5,Ma (pre-Campanian). Uplift may have commenced with an Albian,Aptian (,112,Ma) orogenic event. Copyright © 2008 John Wiley & Sons, Ltd. [source] Syndrome-causing mutations of the BLM gene in persons in the Bloom's Syndrome Registry,,HUMAN MUTATION, Issue 8 2007James German Abstract Bloom syndrome (BS) is caused by homozygous or compound heterozygous mutations in the RecQ DNA helicase gene BLM. Since the molecular isolation of BLM, characterization of BS-causing mutations has been carried out systematically using samples stored in the Bloom's Syndrome Registry. In a survey of 134 persons with BS from the Registry, 64 different mutations were identified in 125 of them, 54 that cause premature protein-translation termination and 10 missense mutations. In 102 of the 125 persons in whom at least one BLM mutation was identified, the mutation was recurrent, that is, it was shared by two or more persons with BS; 19 of the 64 different mutations were recurrent. Ethnic affiliations of the persons who carry recurrent mutations indicate that the majority of such persons inherit their BLM mutation identical-by-descent from a recent common ancestor, a founder. The presence of widespread founder mutations in persons with BS points to population genetic processes that repeatedly and pervasively generate mutations that recur in unrelated persons. Hum Mutat 28(8), 743,753, 2007. Published 2007 Wiley-Liss, Inc. [source] Oral contrast-enhanced sonography for the diagnosis and grading of postsurgical recurrence of Crohn's diseaseINFLAMMATORY BOWEL DISEASES, Issue 9 2008Fabiana Castiglione MD Abstract Background: Postsurgical recurrence (PSR) is very common in patients with Crohn's disease (CD) and previous surgery. Endoscopy is crucial for the diagnosis of PSR, also showing high prognostic value. Bowel sonography (BS) with or without oral contrast enhancement (OCBS) is accurate for CD diagnosis but its role in PSR detection and grading is poorly investigated. The aim was to evaluate the diagnostic accuracy of BS and OCBS for PSR compared to the endoscopical Rutgeerts's grading system. Methods: We prospectively performed endoscopy, BS, and OCBS in 40 CD patients with previous bowel resection to provide evidence of possible PSR. Endoscopy, BS, and OCBS were executed 1 year after surgery, with PSR diagnosis and grading made in accordance with Rutgeerts. BS and OCBS were considered suggestive for PSR in the presence of bowel wall thickness (BWT) >3 mm. OCBS was performed after ingestion of 750 mL of polyethylene glycol (PEG). Also, a receiver operating characteristic (ROC) curve was constructed in order to define the best cutoff of BWT to discriminate mild from severe PSR (grade 0,2 versus 3,4 of Rutgeerts) for both BS and OCBS. Results: In all, 22 out of the 40 CD showed an endoscopic evidence of PSR (55%). A severe PSR was present in 14 patients (64%). Sensitivity, specificity, and positive and negative predictive values were 77%, 94%, 93%, and 80% for BS, and 82%, 94%, 93%, and 84% for OCBS. On the ROC curve a BWT >5 mm showed sensitivity, specificity, and positive and negative predictive values of 93%, 96%, 88%, and 97% for the diagnosis of severe PSR at BS, while a BWT >4 mm was the best cutoff differentiating the mild from the severe CD recurrence for OCBS, with a sensitivity, specificity, and positive and negative predictive values of 86%, 96%, 97%, and 79%, respectively. Conclusions: Both BS and OCBS show good sensitivity and high specificity for the diagnosis of PSR in CD, with a BWT >5 mm for BS and BWT >4 mm for OCBS strongly indicative of severe endoscopic PSR. Accordingly, these techniques could replace endoscopy for the diagnosis and grading of PSR in many cases. (Inflamm Bowel Dis 2008) [source] Commentary by Bun San Chong Chong BS, Pitt Ford TR, Hudson MB (2003) A prospective clinical study of Mineral Trioxide Aggregate and IRM when used as root-end filling materials in endodontic surgery.INTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2009International Endodontic Journal 3 No abstract is available for this article. [source] Fabrication and Tunable Dielectric Properties of (Ba0.7Sr0.3)TiO3 -Glass-Based Thick-Film CapacitorsINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 2 2009Pulipparambil Vasu Divya Ferroelectric glass,ceramics of composition 0.90 (Ba0.7Sr0.3) TiO3,0.10(B2O3:SiO2) (0.90 BST:0.10 BS) synthesized by sol,gel method have been used for the preparation of dielectric thick-film inks. The particle dispersion of the glass,ceramic powders in the thick-film ink formulations have been studied through rheological measurements for fabricating thick-film capacitors by screen printing technique. The thick films derived from such glass,ceramics are found to sinter at considerably lower temperatures than the pure ceramic, and exhibit good dielectric characteristics with a tunability of 32% at 1 MHz under a dc bias field of 35 kV/cm. [source] Joint power, subcarrier and subframe allocation in Multihop relay networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 7 2009Tolga Girici Abstract In this paper we study the problem of subframe, subchannel and power allocation in OFDMA-based multihop relay networks. The system consists of a base station (BS), a number of relay stations (RS) and mobile stations (MS). We consider frame by frame scheduling, where the frame is divided into two subframes such as BS-RS and RS-MS subframes. We study two different problems, satisfying link rate requirements with minimum-weighted total power and maximizing proportional fairness. For the first problem, we find the optimal solution and also propose a less complex subframe and bandwidth allocation scheme with good performance. For the second problem, we propose an algorithm that outperforms an existing scheme with less feedback. Copyright © 2009 John Wiley & Sons, Ltd. [source] Joint packet scheduling and dynamic base station assignment for CDMA data networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 2 2008Christian Makaya Abstract In current code division multiple access (CDMA) based wireless systems, a base station (BS) schedules packets independently of its neighbours, which may lead to resource wastage and the degradation of the system's performance. In wireless networks, in order to achieve an efficient packet scheduling, there are two conflicting performance metrics that have to be optimized: throughput and fairness. Their maximization is a key goal, particularly in next-generation wireless networks. This paper proposes joint packet scheduling and BS assignment schemes for a cluster of interdependent neighbouring BSs in CDMA-based wireless networks, in order to enhance the system performance through dynamic load balancing. The proposed schemes are based on sector subdivision in terms of average required resource per mobile station and utility function approach. The fairness is achieved by minimizing the variance of the delay for the remaining head-of-queue packets. Inter-cell and intra-cell interferences from scheduled packets are also minimized in order to increase the system capacity and performance. The simulation results show that our proposed schemes perform better than existing schemes available in the open literature. Copyright © 2007 John Wiley & Sons, Ltd. [source] Development of a novel mop fanINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 7 2001S. B. Riffat Abstract A novel fan that operates as an air moving device as well as a filter has been investigated. The unit utilizes a brush disk, instead of bladed impellers, within a centrifugal fan casing and is known as a ,mop fan'. The performance of the mop impellers as fans was tested and their characteristic curves were found to be similar to those of centrifugal fans. The characteristics of the mop fan in terms of airflow rate, pressure, and efficiency were tested using a standard method, BS 848. The tests allowed mops of different fibre number and fibre diameter to be constructed and so optimize mop fan performance. Copyright © 2001 John Wiley & Sons, Ltd. [source] Theory of chemical bonds in metalloenzymes.INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 15 2010Abstract Reaction mechanisms of oxygen evolution in native and artificial photosynthesis II (PSII) systems have been investigated on the theoretical grounds, together with experimental results. First of all, our previous broken-symmetry (BS) molecular orbitals (MO) calculations are reviewed to elucidate the instability of the d,-p, bond in high-valent (HV) Mn(X)O systems and the d,-p,-d, bond in HV MnOMn systems. The triplet instability of these bonds entails strong or intermediate diradical characters: ,Mn(IV)O, and ,MnOMn,; the BS MO resulted from strong electron correlation, leading to the concept of electron localizations and local spins. The BS computations have furthermore revealed guiding principles for derivation of selection rules for radical reactions of local spins. As a continuation of these theoretical results, the BS MO interaction diagrams for oxygen-radical coupling reactions in the oxygen evolution complex (OEC) in the PSII have been depicted to reveal scope and applicability of local singlet diradical (LSD) and local triplet diradical (LTD) mechanisms that have been successfully utilized for theoretical understanding of oxygenation reactions mechanisms by p450 and methane monooxygenase (MMO). The manganese-oxide cluster models examined are London, Berlin, and Berkeley models of CaMn4O4 and related clusters Mn4O4 and Mn3Ca. The BS MO interaction diagrams have revealed the LSD and/or LTD mechanisms for generation of molecular oxygen in the total low-, intermediate and high-spin states of these clusters. The spin alignments are found directly corresponding to the spin-coupling mechanisms of oxygen-radical sites in these clusters. The BS UB3LYP calculations of the clusters have been performed to confirm the comprehensive guiding principles for oxygen evolution; charge and spin densities by BS UB3LYP are utilized for elucidation and confirmation of the LSD and LTD mechanisms. Applicability of the proposed selection rules are examined in comparison with a lot of accumulated experimental and theoretical results for oxygen evolution reactions in native and artificial PSII systems. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 [source] Theory of chemical bonds in metalloenzymes XIII: Singlet and triplet diradical mechanisms of hydroxylations with iron-oxo species and P450 are revisitedINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 15 2009Kizashi Yamaguchi Abstract Electronic structures of the Compound I (CpdI) in P450 are investigated on the basis of spin coupling forms of iron-oxo (Fe(IV)O) cores and radical ligand (,L) groups to generalize previous singlet and triplet diradical (TD) mechanisms for oxygenations of alkanes with Fe( IV)O. Orbital interaction schemes for four lower-lying spin configurations of CpdI with HC bond of substrate are examined to elucidate how magnetic coupling modes correlate with radical reaction pathways for hydroxylation reactions on the basis of the broken symmetry (BS) molecular orbital (MO) model. The configuration correlation diagrams for the four configurations model are depicted on the basis of the isoelectronic analogy among O, O2, and Fe( IV)O, in addition to Coulomb exchange energy on the iron site, which determines its local spin configuration. Important role of ligand spin (,L) of CpdI for regulation of hydroxylation mechanisms is clarified with the aid of the spin coupling forms. Transition states for one quartet and three doublet configurations under the BS MO approximation are examined on the basis of potential curve crossings along reaction pathways. The four transition structures and corresponding radical intermediates for methane and trimethyl methane with CpI are located by the BS hybrid Kohn,Sham density functional theory (DFT) (B3LYP) method to confirm the orbital interaction schemes. Spin density populations obtained by the BS B3LYP calculations are found to be consistent with the theoretical predictions based on the four configurations model. The configuration and state correlation diagrams by BS B3LYP before and after spin projection are also consistent with the BS MO interaction schemes, which provide local SD and TD mechanisms of hydroxylation with CpdI. The present BS MO-theoretical framework is useful for systematic understanding of a lot of recent BS hybrid DFT computational results for hydroxylation reactions with CpdI and configuration correlation diagrams reported by several groups. Implications of the present theoretical and computational results are discussed in relation to several experimental characteristics of hydroxylation reactions with iron-oxo species and P450. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source] Extended Hartree,Fock theory of chemical reactions.INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 15 2009Abstract Symmetry and broken symmetry (BS) in molecular orbital description of transition structures and intermediates in oxygenation reactions have been revisited to elucidate states correlation diagrams and mechanisms for addition reactions of molecular oxygen and metal-oxo MO (M = Mn(II) and Fe(II)) species to CC double bonds. Relative stabilities between diradical (DR) and perepoxide (PE) intermediates were thoroughly investigated by several BS hybrid DFT (HDFT) methods and BS CCSD(T) method with and without spin projection. It has been found that recovery of spin symmetry, namely eliminating spin contamination error from the BS solutions, is crucial for the elucidation of reasonable state correlation diagrams and energy differences of the key structures in the oxygenation reactions because the singlet-triplet energy gap for molecular oxygen is large (22 kcal/mol). The BS HDFT followed by spin correction reproduced activation barriers for transition structures along both PE and DR reaction pathways by the use of the CASPT2 method. Basis set dependence on the relative stability between PE and DR intermediates were also examined thoroughly. Solvation effect for DR and PE intermediates was further examined with self-consistent reaction field (SCRF) and SCIPCM methods. Both BS HDFT and CASPT2 have concluded that the DR mechanism is favorable for the addition reaction of singlet oxygen to ethylene, supporting our previous conclusions. The BS HDFT with spin correction was concluded to be useful enough for theoretical investigations of mechanisms of oxygenation reactions. Implications of the computational results were discussed in relation to the theoretical framework (four configuration model) for elucidation of possible mechanisms of epoxidation reactions with Fe(IV)O cores in metalloenzymes on the basis of isolobal analogies among O, OO, and Fe(IV)O. Correspondence between magnetic coupling mode and radical pathway in oxygenations with these species was clarified based on the BS MO interaction diagrams, leading to local singlet and triplet diradical mechanisms for epoxidations. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source] Geometry optimization method based on approximate spin projection and its application to F2, CH2, CH2OO, and active site of ureaseINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 15 2007Yasutaka Kitagawa Abstract A new geometry optimization method based on an approximate spin projection (AP) procedure is proposed to eliminate a spin contamination effect in an optimized structure on a low spin (LS) state of a broken symmetry (BS) method. First, an energy gradient with the AP (AP gradient) is derived and it is applied to the geometry optimization of F2, CH2, and CH2OO in order to obtain their structures without the spin contamination. The optimization method corrects HCH angle of the CH2 about 10° in comparison with the BS method, and indicates that the spin contamination in optimized geometry of the BS LS states is considerably large. Next, an active site of Urease that consists of two Ni(II) ions is optimized by the AP method. The result indicates that structure of the active site is sensitive to a water molecule called W3. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 [source] Correlation between Braden Scale and Palliative Performance Scale in advanced illnessINTERNATIONAL WOUND JOURNAL, Issue 4 2008Vincent Maida Abstract This study describes the significant correlation between the Braden Scale (BS) and the Palliative Performance Scale (PPS) in patients with advanced illness that has not been previously reported. The analysis was based on a prospective sequential case series of 664 patients suffering from advanced illness who were referred to a regional palliative medicine programme in Toronto, Canada. Baseline BS and PPS scores assessed within 24 hours of referral were considered for analysis. After controlling for age, gender, consult site and diagnosis (cancer versus non cancer), we observed a significant positive correlation between baseline PPS and BS scores (r = 0·885, P < 0·001). These findings suggest that for patients with advanced illness where BS is not routinely used, PPS could be considered as a proxy for pressure ulcer risk assessment. [source] A male bovine linkage map for the ADR granddaughter designJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 5 2000H. Thomsen Summary The aim of this paper is to present the construction of a male genetic linkage map as a result of the bovine genome mapping project, which is a common effort of the German cattle breeding federation (ADR), four animal breeding institutes, three blood group laboratories and two animal data and breeding value evaluation centres. In total 20 grandsires with 1074 sires were provided from the German cattle population as reference families, 16 of these paternal half-sib groups are German Holstein families (DH), three are German Simmental (ST) families, and one is a Brown Swiss family (BS). Of 265 markers included in the linkage map, 248 were microsatellite markers, five were bovine blood group systems, eight SSCP markers and four proteins and enzymes. More than 239 000 genotypes resulted from typing the offspring for the respective markers and these were used for the construction of the map. On average 478 informative meioses were provided from each marker of the map. The summarized map length over all chromosomes was 3135.1 cM with an average interval size of 13.34 cM. About 17, 35.7 and 79.1% of the map intervals showed a maximum genetic distance between the adjacent markers of 5, 10 and 20 cM, respectively. The number of loci ranged from two (pseudoautosomal region of the sex chromosome, BTAY) to 15 (BTA23) with an average of 8.8 markers per chromosome. Comparing the length of the chromosomes shows variation from 49.6 cM for BTA26 to 190.5 cM for BTA1 with a mean of 107.7 cM for all autosomes of the genetic linkage map. It was possible to identify chromosomal discrepancies in locus order and map intervals by comparison with other published maps. The map provided sufficient marker density to serve as a useful tool for a scan of segregating quantitative trait loci. Zusammenfassung Im vorliegenden Artikel wird die Erstellung der genetischen Markerkarten für das Rindergenom im Rahmen des Genomanalyseprojektes der Arbeitsgemeinschaft Deutscher Rinderzüchter (ADR) vorgestellt. Auf der Basis des ,Granddaughter Designs' wurde ein Familienmaterial bestehend aus 20 väterlichen Halbgeschwistergruppen mit 1074 Söhnen für die Typisierung mit genetischen Markern bereitgestellt. Insgesamt 16 dieser paternalen Halbgeschwisterfamilien lassen sich der Rasse Deutsche Holsteins zuordnen, drei Familien entstammen der Rasse Deutsches Fleckvieh, und eine Familie gehört der Rasse Deutsches Braunvieh an. Dabei variiert die Anzahl der Söhne von 19,128 pro Vater. Für die Typisierung wurden 248 Mikrosatellitenmarker aus bereits publizierten Karten ausgewählt. Zusätzlich konnten 8 SSCP-und RFLP Marker, 5 Blutgruppensysteme und 4 Proteinmarker zur Entwicklung der genetischen Karte herangezogen werden. Die Anzahl der Marker variierte von 2 (pseudoautosomaler Bereich des Geschlechtschromosoms) bis 15 (Chromosom 23), wobei durchschnittlich 8.8 genetische Marker pro Chromosom typisiert wurden. Im Durchschnitt lieferten die genetischen Marker 478 informative Meiosen pro Marker. Alle Typisierungsergebnisse wurden in die Kieler Markerdatenbank übertragen und auf etwaige Fehler geprüft. Als Ergebnis konnten die genetischen Karten für alle 29 Autosomen und den pseudoautosomalen Bereich des Geschlechtschromosoms erstellt werden. Dabei wurde ein Bereich von 3135.1 cM des Rindergenoms abgedeckt, wobei die Länge des durchschnittlichen Markerintervalls 13.34 cM beträgt. Die Längen der Chromosomen zeigten eine Variation von 49.6 cM für Chromosom 26 bis zu 190.5 cM für Chromosom 1. Aufgrund der Anzahl informativer Meiosen und der Markerdichte bildet diese genetische Markerkarte in gutes Instrument für eine genomweite Suche nach segregierenden Genorten, die für die Variation von quantitativen Merkmalen verantwortlich sind. [source] Relationship among five populations of Bactrocera dorsalis based on mitochondrial DNA sequences in western Yunnan, ChinaJOURNAL OF APPLIED ENTOMOLOGY, Issue 7 2008P. Chen Abstract Genetic variation in the Oriental fruit fly, Bactrocera dorsalis (Hendel), was analysed using five populations from western Yunnan, China, to elucidate the distribution and likely dispersal patterns of this fly. A 503-bp portion of the mitochondrial cytochrome oxidase gene was sequenced from a minimum of seven individuals from each of five fly populations; 25 haplotypes were observed among 57 individuals in these populations. High genetic diversity within populations was detected. Genetic distances between haplotypes reached 1.2%. Mantel tests did not indicate any isolation because of geographic distance. The Ruili (RL) population was significantly isolated from the others (pairwise Fst ranging from 0.10 to 0.21, and average genetic distances being higher than for all other four population comparisons). RL is geographically separated from the other sites by the Gaoligong Mountains. The Liuku (LK) population had a close genetic relationship with the Lujiangba (LJB) population, suggesting that the LK population probably originated from LJB that is located in the same valley to the south. The Baoshan (BS) and Dali (DL) populations were also geographically isolated from the others, not originating from LJB and RL, where the fly is present year-round. The north-south orientation of mountains and valleys in western Yunnan appears to prevent latitudinal gene exchange by dispersing flies and thus divides the five populations into four relatively independent zones, namely BS, DL, LK-LJB and RL. In addition, air currents that generally flow south to north appear to assist dispersing flies, especially in valleys between the mountain chains. [source] Overexpression of RGPR-p117 enhances regucalcin gene promoter activity in cloned normal rat kidney proximal tubular epithelial cells: Involvement of TTGGC motifJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2006Natsumi Sawada Abstract A novel protein RGPR-p117 was discovered as regucalcin gene promoter region-related protein that binds to the TTGGC motif using a yeast one-hybrid system. RGPR-p117 is localized in the nucleus of kidney cells, and overexpression of RGPR-p117 can modulate regucalcin protein and its mRNA expression in the cloned normal rat kidney proximal tubular epithelial NRK52E cells. This study was undertaken to determine whether overexpression of RGPR-p117 enhances the regucalcin promoter activity using the ,710/+18 LUC construct (wild-type) or ,710/+18 LUC construct (mutant) with deletion of ,523/,435 including TTGGC motif. NRK52E cells (wild-type) or stable HA-RGPR-p117/phCMV2-transfected cells (transfectant) were cultured in Dulbecco's minimum essential medium (DMEM) containing 5% bovine serum (BS). Wild-type cells or transfectants were transfected with the ,710/+18 LUC construct vector or the ,710/+18 LUC construct with deletion of ,523/,435. Wild-type cells or transfectants with subconfluency were cultured for 48 h in a DMEM medium containing either vehicle, BS (5%), or parathyroid hormone (1,34) (PTH; 10,7 M). Luciferase activity in wild-type cells was significantly increased with culture of BS or PTH. This increase was significantly blocked in the presence of various protein kinase inhibitors (staurosporine and PD 98059). Luciferase activity in transfectants was significantly increased as compared with that of wild-type cells in the absence of BS or PTH. The increase in luciferase activity in transfectants was completely decreased in mutant with deletion of ,523/,435 sequence of regucalcin promoter. This was also seen using the ,710/+18 LUC construct with deletion of ,523/,503 sequence containing TTGGC motif. The increase in luciferase activity in transfectants was not significantly enhanced with culture of BS (5%), PTH (10,7 M), Bay K 8644 (10,6 M), phorbol 12-myristate 13-acetate (PMA; 10,6 M), or N6, 2,-dibutyryl cyclic adenosine 3,, 5,-monophosphate (DcAMP; 10,4 M). The increase in luciferase activity in transfectants was completely inhibited with culture of dibucaine (10,6 M), staurosporine (10,9 M), PD 98059 (10,8 M), wortmannin (10,8 M), genistein (10,6 M), vanadate (10,6 M), or okadaic acid (10,6 M) which are inhibitors of various kinases and protein phosphatases. This study demonstrates that RGPR-p117 can enhance the regucalcin promoter activity which is related to the NF-1 consensus sequences including TTGGC motif, and that its enhancing effect is partly mediated through phosphorylation and dephosphorylation in NRK52E cells. J. Cell. Biochem. 99: 589,597, 2006. © 2006 Wiley-Liss, Inc. [source] Chemical Characterization of Liver Lipid and Protein from Cold-Water Fish SpeciesJOURNAL OF FOOD SCIENCE, Issue 6 2006Peter J. Bechtel ABSTRACT:, The largest US harvests of marine fish for human consumption are from Alaska waters. Livers from these fish are combined with other fish offal and made into fish meal and oil or discarded. The purpose of this study was to characterize liver lipids and proteins from important commercial species including walleye pollock (WP), pink salmon (PS), Pacific halibut (PH), flat head sole (FS), and spiny head rock fish (RF), and underutilized species including arrow tooth flounder (AF) and big mouth sculpin (BS). Liver lipid content ranged from 50.3% in WP to 3.3% in PS. Protein content ranged from 7.7% in WP to 18.4% in BS. PS livers had the highest content of ,-3 fatty acids at 336 mg/g of oil and AF had the lowest content at 110 mg/g of oil. There were significant differences in the content of 9 amino acids with methionine and lysine values ranging from 2.66% to 3.43% and 7.19% to 9.45% of the total amino acids, respectively. Protein from the cold water marine fish livers was of high quality and the oils contained substantial quantities of ,-3 fatty acids. Fish livers had distinct chemical properties and can be used for the development of unique food ingredients. 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