bluuebunny/crossref_metadata_2025 huggingface dataset:
The Pacing to Avoid Cardiac Enlargement (PACE) Trial: Clinical Background, Rationale, Design, and Implementation
Authors: FUNG JEFFREY WING‐HONG , CHAN JOSEPH YAT‐SUN , OMAR RAZALI , HUSSIN AZLAN , ZHANG QING , YIP GABRIEL , LAM KAI HUAT , FANG FANG , YU CHEUK‐MAN
Published: May 2007

Background: Deleterious effect on left ventricular (LV) function was observed with conventional right ventricular apical (RVA) pacing. Preliminary data suggested that biventricular pacing (BiV) may be superior to RVA pacing in patients with LV systolic dysfunction. However, the optimal pacing mode and site(s) for patients with normal LV systolic function remain controversial.

Methods: The Pacing to Avoid Cardiac Enlargement (PACE) trial is a prospective, multicenter, randomized, double blinded, parallel, controlled study aiming to determine if BiV pacing is better than conventional RVA pacing in preserving LV systolic function and preventing remodeling in patients with LV ejection fraction (EF) >45% indicated for pacing. This study targets to recruit 200 patients from various centers in Asia, all of whom will receive BiV pacemaker implantation before being randomized to either atrial‐based RVA or BiV pacing for 1 year. Their echocardiographic parameters including LV volumes, left ventricular ejection fraction (LVEF), and dyssynchrony index by tissue Doppler imaging, exercise capacity, quality of life assessment, neurohormone levels, and clinical events will be assessed before and after pacing. The primary endpoints are changes in LV end‐systolic volume and LVEF 1 year after pacing. It is designed with 90% power to detect a 5% difference in the LVEF after 1 year of pacing. The enrollment began in 2006. It is expected to conclude at the end of 2008.

Conclusion: The PACE trial will determine whether atrial‐based BiV pacing can preserve LV systolic function and prevent LV adverse remodeling induced by conventional RVA pacing in patients with normal LV systolic function and standard pacing indication.
Histodynamics of bone tissue formation around immediately loaded cylindrical implants in the rabbit
Authors: Vandamme Katleen , Naert Ignace , Geris Liesbet , Sloten Jozef Vander , Puers Robert , Duyck Joke
Published: May 2007

Objectives: The local mechanical environment influences early peri‐implant tissue formation. It is still unclear whether immediate loading limits or promotes peri‐implant osteogenesis and which mechanical parameters are important herein. The present study evaluated the influence of well‐controlled mechanical stimuli on the tissue response around immediately loaded cylindrical turned titanium implants at two different observation periods.

Material and methods: A repeated sampling bone chamber, consisting of dual‐structure perforated hollow cylinders with a cylindrical implant, was installed in the tibia of 14 rabbits and used to conduct three displacement‐controlled immediate loading experiments: (i) 30 μm – 400 cycles/day – 1 Hz frequency – 2 ×/week – 6 weeks; (ii) 30 μm – 400 cycles/day – 1 Hz – 2 ×/week – 6 weeks, followed by another 6 weeks with a 50 μm – 800 cycles/day – 1 Hz – 2 ×/week loading protocol; and (iii) 0 μm implant displacement for 12 weeks. A linear mixed model and logistic mixed model with α=5% were conducted on the data set.

Results: The tissue area fraction was significantly the highest after 12 weeks of loading. The bone area fraction was significantly different between all three loading conditions, with the highest values for the 12‐week loading experiment. Twelve‐week stimulation resulted in a significantly higher mineralized bone fraction than 6 weeks. Loading did have a significantly positive effect on the mineralized bone fraction. The incidence of osteoid‐to‐implant and bone‐to‐implant contact increased significantly when loading the implant for 12 weeks.

Conclusion: Immediate loading had a positive effect on the tissue differentiation and bone formation around cylindrical turned titanium implants. Controlled implant micro‐motion up to 50 μm had a positive effect on the bone formation at its interface.
Histological evaluation of oral implants inserted with different surgical techniques into the trabecular bone of goats
Authors: Shalabi Manal M. , Wolke Johannes G. C. , De Ruijter Anja J. E. , Jansen John A.
Published: May 2007

Objective: The aim of this study was to investigate the influence of implant surface topography and surgical technique on bone response.

Material and methods: For the experiment, 48 screw‐designed implants were used with two different surface finishes, i.e. machined and ‘blasted, etched’. The implants were inserted into the left and right medial femoral condyle of eight goats using three different surgical approaches: press‐fit (implant diameter=implant bed diamete(r), undersized (implant bed diameter<implant diameter) and osteotome. Each femoral condyle received three implants. After an implantation period of 12 weeks, the implants were retrieved and prepared for histological and histomorphometrical evaluation (bone contact and bone mass).

Results: Light microscopy revealed that in general, the bone response to all implants was very similar. On the other hand, histomorphometry suggested that the bone‐to‐implant contact for the ‘blasted, etched’ implants inserted by an undersized technique was higher compared with machined implants and the other surgical approaches, but the observed differences were not significant. Bone mass measurements did not reveal the occurrence of clear differences between groups and surgical approaches.

Conclusion: Supported by our findings, we conclude that implants provided with a ‘blasted, etched’ surface and installed in trabecular bone using an undersized preparation technique appear to support an enhanced bone–implant contact. The use of an osteotome technique did not lead to improved results.
Infection at titanium implants with or without a clinical diagnosis of inflammation
Authors: Renvert Stefan , Roos‐Jansåker Anne‐Marie , Lindahl Christel , Renvert Helena , Rutger Persson G.
Published: May 2007

Objectives: To assess the microbiota at implants diagnosed with peri‐implantitis, implant mucositis, or being clinically healthy.

Material and methods: Clinical and microbiological data were collected from 213 subjects (mean age: 65.7±14) with 976 implants in function (mean: 10.8 years, SD±1.5). Forty species were identified by the checkerboard DNA–DNA hybridization method.

Results: Implant mean % plaque score was 41.8±32.4%. Periodontitis defined by bone loss was found in 44.9% of subjects. Implant mucositis was diagnosed in 59% and peri‐implantitis in 14.9% of all cases. Neisseria mucosa, Fusobacterium nucleatum sp. nucleatum, F. nucleatum sp. polymorphum, and Capnocytophaga sputigena dominated the implant sub‐mucosal microbiota and the sub‐gingival microbiota at tooth sites. Implant probing pocket depth at the implant site with the deepest probing depth was correlated with levels of Eikenella corrodens (r=0.16, P<0.05), the levels of F. nucleatum sp. vincentii (r=0.15, P<0.05), Porphyromonas gingivalis (r=0.14, P<0.05), and Micromonas micros (r=0.17, P=0.01). E. corrodens was found in higher levels at implants with mucositis compared with implant health (P<0.05). Subjects who lost teeth due to periodontitis had higher yields of F. nucleatum sp. vincentii (P<0.02) and N. mucosa (P<0.05). Independent of implant status subjects with teeth had higher levels of P. gingivalis (P<0.05), and Leptotrichia buccalis (P<0.05).

Conclusions: At implant sites studied, few bacteria differed by whether subjects were dentate or not or by implant status.
A comparison of bone mineral density in the spine, hip and jaws of edentulous subjects
Authors: Drage Nicholas A. , Palmer Richard M. , Blake Glen , Wilson Ron , Crane Fiona , Fogelman Ignac
Published: May 2007

Objectives: The aim was to investigate the relationship between bone mineral density (BMD) of the jaws (mandible and maxilla) and other skeletal sites. In addition, the influence of gender, smoking and the number of years without natural teeth were examined.

Materials and methods: 18 edentulous patients (9 females, 9 males) with a mean age of 67.1 (sd 12.6) years had DXA scans to assess the BMD of the lumbar spine and hip, together with the ramus, body and symphysis of the mandible and the anterior of the maxilla.

Results: BMD values for the ramus were similar to those for the femur but significantly lower than the lumbar spine. The body and anterior mandible had higher values and the anterior maxilla lower values than both the femur and ramus. The ramus BMD showed moderately strong relationships with the standard measures of BMD in the spine and hip, but the BMD of other areas of the jaws showed no relationship with skeletal sites. The BMD for both the hip and the ramus showed an inverse relationship with increasing age. There was no statistically significant relationship between BMD of hip, spine and jaw and either years edentulous or cigarette years. (207)

Conclusions: Although the ramus of the mandible may show correlation of BMD with skeletal sites, the areas of the jaws where implants may be placed do not. Therefore BMD of the skeletal sites could not be used to predict BMD of the jaws.

The BMD of the jaws as measured by DXA showed no relationship with either years edentulous or cigarette smoking.
A topical lipophilic niacin derivative increases NAD, epidermal differentiation and barrier function in photodamaged skin
Authors: Jacobson Elaine L. , Kim Hyuntae , Kim Moonsun , Williams Joshua D. , Coyle Donna L. , Coyle W. Russell , Grove Gary , Rizer Ronald L. , Stratton M. Suzanne , Jacobson Myron K.
Published: May 2007

Abstract: The effects of myristyl nicotinate (MN), a nicotinic acid derivative designed to deliver nicotinic acid to skin without vasodilatation, on subjects with photodamaged skin have been studied. MN increased skin cell nicotinamide adenine dinucleotide (NAD) by 25% (P = 0.001) demonstrating effective delivery of nicotinic acid to skin. Relative to placebo, MN treatment of photodamaged facial skin increased stratum corneum thickness by approximately 70% (P = 0.0001) and increased epidermal thickness by approximately 20% (P = 0.001). In two separate studies, MN treatment increased rates of epidermal renewal by 6% (P = 0.003) to 11% (P = 0.001) and increased the minimal erythemal dose by 8.9 (P = 0.07) and 10% (P = 0.05) relative to placebo. MN treatment resulted in reductions in the rates of transepidermal water loss (TEWL) of approximately 20% relative to placebo on cheeks (P = 0.012) and arms (P = 0.017) of study subjects. Results of a tape stripping challenge before and after MN treatment demonstrated a significant correlation (P = 0.03) between increased skin NAD content and resistance to changes in TEWL for MN treated but not placebo subjects. Rates of TEWL changed more rapidly and to a greater extent in atopic subjects compared with normal subjects. The results indicate that MN enhances epidermal differentiation and barrier function in skin, suggesting that this method of nicotinic acid delivery may prove useful in limiting progression of actinic skin damage and possibly in treating other conditions involving skin barrier impairment.
Anchorless keratinocyte survival: an emerging pathogenic mechanism for squamous cell carcinoma in recessive dystrophic epidermolysis bullosa
Authors: Rodeck Ulrich , Fertala Andrzej , Uitto Jouni
Published: May 2007

Abstract:  Squamous cell carcinomas in patients sufering from recessive dystrophic epidermolysis bullosa are highly invassive and frequently metastatic. Expression of a collagen VII fragement (NC1) has been described as a prerequisite for the development of this tumor form. This commentary focuses on potential molecular mechanisms by which expression of the NC1 fragment may augment anchorage‐independent growth and survival of malignant keratinocytes.
Experimental models of epidermolysis bullosa acquisita
Authors: Sitaru Cassian
Published: May 2007

Abstract:  Epidermolysis bullosa acquisita (EBA) is an organ‐specific autoimmune disease with a well‐defined antigen‐autoantibody system. Recently, mutually complementary ex vivo and animal models were developed for this disease. The blister formation of EBA can be reproduced by passively transferring antibodies against type VII collagen into mice. In addition, the Fc‐dependent interaction of autoantibodies with granulocytes resulting in dermal–epidermal separation can be studied using patient autoantibodies and leukocytes from healthy donors in cryostat sections of normal human skin. Finally, the autoimmune response and the active blistering disease are replicated by immunizing mice with autologous type VII collagen. The results obtained using these experimental systems provided conclusive evidence that EBA is an antibody‐mediated autoimmune disease. In addition, these models represent powerful new tools for understanding EBA pathophysiology and will likely offer unique opportunities to investigate the molecular mechanisms of antibody‐mediated autoimmune diseases in general. Thus, due to improved disease modelling, EBA emerges as an exquisitely instructive model disease to study fundamental, biologically and clinically crucial aspects of antibody‐mediated organ‐specific autoimmune diseases that extend well beyond the limits of autoimmunity against type VII collagen. The new mechanistic insights gained from investigating EBA pathogenesis will facilitate the design of immunomodulatory interventions for this and other pathogenetically related organ‐specific, antibody‐dependent autoimmune diseases.
Developing Good Practice in the Clinical Assessment of People With Profound Intellectual Disabilities and Multiple Impairment
Authors: Carnaby Steve
Published: May 2007

Abstract  The task of assessing people with profound intellectual disabilities and multiple impairments can be a daunting one, for experienced and newly qualified clinicians and practitioners alike. Difficulties with definitions in the context of challenging, excluding service delivery models can sometimes lead to incoherent and inconsistent approaches. The author examines a number of issues, including the paucity of adequately sensitive, standardized assessment tools, the importance of collaborative working, and the acknowledgment that services can be ill‐equipped to face the challenges presented by people with such complex and chronic support needs. The role of an overly generic service philosophy in potentially limiting the work of clinicians is noted, and the author notes that evaluating development is a crucial factor in any overall assessment. The author concludes with a number of recommendations for developing good practice in this crucial area of the support process, including: agree on terminology and inclusion criteria; take a transdisciplinary approach; use a developmental model; consider the impact of neurological conditions; select measures and informants carefully; and consider the assessment as an intervention.
Integration of Education and Care Given to Children With Profound Multiple Disabilities in Switzerland
Authors: Petitpierre G. , Wolf D. , Dietrich A. , Benz M. , Adler J.
Published: May 2007

Abstract  The authors studied how care provision and educational and therapeutic support for children with profound multiple disabilities are organized and coordinated in the German‐, French‐, and Italian‐speaking parts of Switzerland. Study questions were: (a) how do the care and educational elements of support coexist in the everyday life of these children, and (b) at the organizational level, who provides the respective support in schools and institutions? The study was conducted via questionnaires sent to 103 schools and institutions, and involved 177 children with profound multiple disabilities, 150 teachers or “special educators,” and two subgroups made up of 26 pairs of healthcare professionals and teachers. Results showed a significant correlation between the allocation of health and personal care and personalized educational and therapeutic support, and that teaching staff undertake tasks relating to health and personal care, just as healthcare professionals also have an educational capacity. However, these two groups of professionals have differing perceptions of their roles and functions in caring for children with profound multiple disabilities. The complementarities of care provision and educational support in Switzerland can be confirmed to some extent. The nature of the support required often forces staff to work outside of their traditional fields of expertise. The authors note that there is a genuine distribution of tasks between different professionals, but they do not confirm a common perception of such tasks.
An Investigation into the Dimensionality of TOEFL Using Conditional Covariance‐Based Nonparametric Approach
Authors: Jang Eunice Eunhee , Roussos Louis
Published: May 2007

This article reports two studies to illustrate methodologies for conducting a conditional covariance‐based nonparametric dimensionality assessment using data from two forms of the Test of English as a Foreign Language (TOEFL). Study 1 illustrates how to assess overall dimensionality of the TOEFL including all three subtests. Study 2 is aimed at illustrating how to conduct dimensionality analyses for a testlet‐based test by focusing on the Reading Comprehension (RC) section in combination with item content analyses and hypothesis testing. The results of Study 1 indicated that both TOEFL forms involve two dominant dimensions corresponding to the Listening Comprehension section and the combination of the Reading Comprehension section and Structure and Written Expression section. The extensive RC analyses from Study 2 revealed strong evidence that a significant amount of the RC multidimensionality came from testlet effects. Confirmatory analyses coupled with exploratory cluster analyses and substantive item content analyses further identified dimensionality structure having to do with reading subskills.
The Sensitivity of Value‐Added Teacher Effect Estimates to Different Mathematics Achievement Measures
Authors: Lockwood J. R. , McCaffrey Daniel F. , Hamilton Laura S. , Stecher Brian , Le Vi‐Nhuan , Martinez José Felipe
Published: May 2007

Using longitudinal data from a cohort of middle school students from a large school district, we estimate separate “value‐added” teacher effects for two subscales of a mathematics assessment under a variety of statistical models varying in form and degree of control for student background characteristics. We find that the variation in estimated effects resulting from the different mathematics achievement measures is large relative to variation resulting from choices about model specification, and that the variation within teachers across achievement measures is larger than the variation across teachers. These results suggest that conclusions about individual teachers' performance based on value‐added models can be sensitive to the ways in which student achievement is measured.
WEDDELL SEAL UNDERWATER CALLING RATES DURING THE WINTER AND SPRING NEAR MAWSON STATION, ANTARCTICA
Authors: Rouget P. A. , Terhune J. M. , Burton H. R.
Published: May 2007

Abstract

Underwater vocalization monitoring and surveys, both on ice and underwater, were used to determine if Weddell seals (Leptonychotes weddellii) near Mawson Station, Antarctica, remain under the fast ice during winter within close range of breeding sites. Daytime and nighttime underwater calling rates were examined at seven breeding sites during austral winter and spring to identify seasonal and diel patterns. Seals rarely hauled out at any of the sites during winter, although all cohorts (adult males, females, and juveniles) were observed underwater and surfacing at breathing holes throughout winter (June–September) and spring (October–December). Seal vocalizations were recorded during each sampling session throughout the study (n= 102 daytime at seven sites collectively, and n= 5 24‐h samples at each of two sites). Mean daytime calling rate was low in mid‐winter (July) (mean = 18.9 ± 7.1 calls/min) but increased monthly, reaching a peak during the breeding season (November) (mean = 62.6 ± 15.7 calls/min). Mean nighttime calling rate was high throughout the winter and early spring (July–October) with mean nocturnal calling rate in July (mean = 61.8 ± 35.1 calls/min) nearly equal to mean daytime calling rate in November (during 24‐h daylight). Reduced vocal behavior during winter daylight periods may result from animals utilizing the limited daylight hours for nonvocal activities, possibly feeding.
QUANTIFICATION OF TERRESTRIAL HAUL‐OUT AND ROOKERY CHARACTERISTICS OF STELLER SEA LIONS
Authors: Ban Stephen , Trites Andrew W.
Published: May 2007

Abstract

Steller sea lions (Eumetopias jubatus) are known to have occupied the same terrestrial haul‐out and rookery sites across the North Pacific Rim for centuries, but it is not known why they choose and stay at these locations, or what defines their preferred habitat. Classifying and comparing the shoreline type of haul‐outs and rookeries against sites not used by Steller sea lions showed that they preferentially locate their haul‐outs and rookeries on exposed rocky shorelines and wave‐cut platforms. However, no preference was found for selecting rookeries on sheltered shore types. Shoreline types used less frequently by sea lions included fine‐to‐medium‐grained sand beaches, mixed sand and gravel beaches, gravel beaches, and sheltered rocky shores. Quantifying the shoreline types used by sea lions confirms anecdotal reports of habitat preferences and may prove useful in identifying and protecting sea lion terrestrial habitat, or in forecasting how climate change might affect the distribution of sea lions.
SITE FIDELITY, ASSOCIATIONS, AND MOVEMENTS OF CUVIER'S (ZIPHIUS CAVIROSTRIS) AND BLAINVILLE'S (MESOPLODON DENSIROSTRIS) BEAKED WHALES OFF THE ISLAND OF HAWAI‘I
Authors: McSweeney Daniel J. , Baird Robin W. , Mahaffy Sabre D.
Published: May 2007

Abstract

Although the Ziphiidae are the second‐most speciose family of cetaceans, information on beaked whale species and populations has been limited by the difficulties in finding and approaching free‐ranging individuals. Site fidelity, patterns of association, and movements of two species, Cuvier's (Ziphius cavirostris) and Blainville's (Mesoplodon densirostris) beaked whales, were assessed using a 21‐yr photographic data set from the west coast of the island of Hawaii. Resightings of individuals of both species spanned 15 yr, suggesting long‐term site fidelity to the area. Long‐term resightings were documented primarily from adult females of both species. Group sizes for both species were small and most groups had only a single adult male present. For Blainville's beaked whales, repeated associations between adult females and adult males were documented for all resightings of adult males over periods from 1 to 154 d. Among adult females, although repeated associations occurred up to 9 yr apart, individuals were seen separately in intervening years. Individuals of both species seen on multiple occasions were typically documented in multiple months/seasons, suggesting they may use the study area throughout the year. Such long‐term site fidelity has implications both for potential population structure and for susceptibility of beaked whale populations to anthropogenic impacts.
Effects of Vegetable Juice Powder Concentration and Storage Time on Some Chemical and Sensory Quality Attributes of Uncured, Emulsified Cooked Sausages
Authors: Sindelar J.J. , Cordray J.C. , Sebranek J.G. , Love J.A. , Ahn D.U.
Published: May 2007

ABSTRACT:  Uncured, no‐nitrate/nitrite‐added meat products can be manufactured with vegetable juice powder (VJP) and a starter culture containing Staphylococcus carnosus, resulting in quality and sensory attributes similar to traditional cured products. The 1st objective of this study was to determine the effects of varying concentrations of VJP and incubation times (MIN‐HOLD) on quality characteristics, including lipid oxidation, color, and cured meat pigment concentrations, of emulsified‐frankfurter‐style‐cooked (EFSC) sausages over a 90‐d storage period. The 2nd objective was to compare residual nitrate and nitrite content resulting from different processing treatments and the 3rd objective was to assess sensory properties of finished products. Four EFSC sausage treatments (TRT) (TRT 1: 0.20% VJP, 30 MIN‐HOLD; TRT 2: 0.20% VJP, 120 MIN‐HOLD; TRT 3: 0.40% VJP, 30 MIN‐HOLD; TRT 4: 0.40% VJP, 120 MIN‐HOLD) and a sodium nitrite‐added control (C) were used for this study. No differences for lipid oxidation (TBARS) between any TRTs and C or over time were observed. No differences (P > 0.05) for CIE L* values were found between TRTs. CIE a* and reflectance ratio values revealed that TRTs 2, 4, and C were redder than TRTs 1 and 3 at day 0. Trained sensory intensity ratings for cured aroma, cured color, cured flavor, uniform color, and firmness determined that all but TRT 1 were similar to C. These results indicate a longer incubation time (120 compared with 30 min) was found more critical than VJP level (0.20% or 0.40%) to result in products comparable to a sodium nitrite‐added control.
Chemical Characterisation of Geological Raw Materials Used in Traditional Ceramics
Authors: Gazulla Maria Fernanda , Gomez Maria Pilar , Barba Antonio , Orduña Monica
Published: May 2007

A wide range of natural raw materials is used in the manufacture of traditional ceramic products such as ceramic tiles, frits, glazes and pigments. The chemical composition of these raw materials needs to be strictly controlled to assure end‐product quality and enable the identification of the origin of defects caused by impurities or contamination. Six types of ceramic raw materials (silica sand, clays and kaolin, feldspars and related minerals, calcium and magnesium carbonates, sodium and calcium borates, and zirconium silicates) have been analysed in this study. X‐ray fluorescence (XRF), potentiometry, coulometry and atomic absorption spectrometry (AAS) were used in this chemical characterisation. A methodology has been established for characterising each studied raw material, by identifying the chemical elements to be determined, selecting the most appropriate technique and validating each measurement. The reference materials used for validation were BCS CRM 267, 313/1, 393 and 388 (BAS), GBW 03103, GBW 07404, NIST SRM 181, 201a and 1835, Euronorm CRM 782‐1 and Syenite SY‐2. The results showed that most of the elements present in the geological samples used as traditional ceramic raw materials could be determined by XRF. The determination of light elements, such as lithium, fluorine and boron, is more suitably conducted by ICP‐AES/AAS, potentiometry or potentiometry/ICP‐AES respectively. Organic and inorganic carbon could be determined by coulometry. Inorganic carbon (CO2) could also be determined by coulometry or by thermogravimetry, if samples did not contain clay minerals. Loss on ignition was always determined by gravimetry.
Sampling, Sample Preparation and ICP‐MS Chemical Analysis of Lake Baikal Sponges
Authors: Paradina Ludmila Ph. , Kulikova Natalie N. , Suturin Alexander N. , Saibatalova Yelena V.
Published: May 2007

Procedures for sampling, sample preparation and ICP‐MS analysis of endemic sponges from Lake Baikal have been developed. Sample decomposition was carried out using an open acid decomposition with ultrasound treatment. The distribution of nineteen elements (Mg, Al, P, Ca, Ti, Mn, Co, Ni, Cu, Rb, Sr, Y, Cd, Ba, La, Ce, Pb, Th and U) in different parts of a sponge's body (outer and inner layers and layers adjacent to the substratum) was studied. Detection limits were determined; these ranged from 0.013 to 4.12 μg g‐1 for trace elements and from 23 to 130 μg g‐1 for biogenic elements. The degree of elemental uptake by living substances is discussed with regard to the environment.
Platinum‐Group Element and Rhenium Concentrations in Low Abundance Reference Materials
Authors: Meisel Thomas , Moser Johann
Published: May 2007

One or two gram aliquots of twelve reference materials with low platinum‐group element (PGE) abundances (Ir concentrations ranging from 30 to 510 pg g‐1) were analysed by isotope dilution ICP‐MS using an on‐line chromatographic matrix separation after acid digestion in a high pressure asher (HPA‐S) to determine the concentrations of Ru, Pd, Re, Ir and Pt. Osmium concentrations were determined via ID‐ICP‐MS but as volatile OsO4, whereas Rh concentrations were calculated by comparing the peak areas of the chromatographic peak with that of a standard solution. Validation of the method was performed and the concepts of traceability and measurement uncertainty were applied to assure comparability. The reference materials BCR‐2, BHVO‐1, BHVO‐2, BIR‐1, DNC‐1, EN026 10D‐3, MAG‐1, RGM‐1, SCo‐1, SDO‐1, TDB‐1 and W‐2 were investigated to test for their usefulness for certification. The use of TDB‐1 is highly recommended because it is homogeneous at the two gram level and many values based on several different analytical procedures have been published. It is recommended that our efforts should focus on the certification of this reference material to reduce the uncertainties of its currently certified values (Pd and Pt only) and to assign certified values to the other PGE and Re. It is necessary to have at least one well‐characterised RM for validation of methods applied to the analysis of PGE and Re in low abundance samples, although the matrix of TDB‐1 might not completely match those of many samples.
Sampling the Environment: Twelve Key Questions That Need Answers
Authors: Ramsey Michael H.
Published: May 2007

This review discusses the vital importance of field sampling as the first stage in the process of measuring the concentration of any components in the environment. The priorities for future research in this subject are identified by reference to twelve key questions that need to be addressed. These questions raise controversial issues, which need resolution before significant progress can be made in improving the quality of environmental measurements, and perhaps more importantly, the reliability of the decisions that are made worldwide that are based on these measurements.
Comparison of Theories for the Variance Caused by the Sampling of Random Mixtures of Non‐Identical Particles
Authors: Geelhoed Bas , Glass Hylke‐Jan
Published: May 2007

When sampling a random mixture of non‐identical particles, the minimum sample size can be determined once the relationship between the sample size and the variance is known. Many different theories have been proposed to describe this relationship. This article provides a novel and systematic comparison of existing theories based on a set of objective criteria. It is found that none of the existing theories meet all criteria, making further research into the development of a suitable theory necessary.
A Comparison of Statistical Techniques for Detecting Analytical Bias in Geoanalysis
Authors: de Castilho Márcio Veloso
Published: May 2007

Detecting analytical bias is a valuable step during method validation and, in the case of the mining industry, fundamental when one validates the geological databases used for resource estimation. This will generally affect the costs of future investments in new or expanding projects. This paper details frequently used techniques for doing this, with their theoretical background, advantages and shortcomings, providing a deeper insight in how to choose a method for special applications. This is done by means of a review of the specialised literature, and by showing practical applications. The latter is done by choosing some of the most commonly used methods, comparing them using Monte Carlo simulations and testing in some real applications (analytical methods used in Brazilian prospects for copper, gold and iron). Consequently, laboratory specialists will have a better understanding of statistical tools for this purpose, being able to provide their customers with a very consistent assurance of chemical analytical results. It is shown that some commonly used statistical methods for this type of comparison are not applicable, and in some cases, one must resort to more complicated models. These are, however, easily implemented computationally, and the mathematical details are shown.
Spontaneous ruptured primary hepatic angiosarcoma coincident with Schistosoma Japonica liver fibrosis
Authors: Wang Ze‐sheng , Wang Wei‐xing , Xiong Cheng‐long , Zhan Na , Li Hui
Published: May 2007

Aim:  We report herein a case of spontaneous ruptured primary hepatic angiosarcoma coincident with Schistosoma Japonica liver fibrosis and review the correlative literature.

Methods:  The resected specimen was examined by histopathological and immunohistochemical evaluation.

Results:  The final diagnosis was spontaneous ruptured primary hepatic angiosarcoma coincident with Schistosoma Japonica liver fibrosis

Conclusion:  Considering the nature of primary hepatic angiosarcoma, in particular the ruptured hepatic angiosarcoma, it is obviously desirable to avoid any unnecessary delay or definitive surgical treatment. It is presumed that angiosarcoma in the liver has a possible association with S. japonicum and the deposition of ovae in liver.
Bezafibrate induces multidrug‐resistance P‐Glycoprotein 3 expression in cultured human hepatocytes and humanized livers of chimeric mice
Authors: Shoda Junichi , Okada Kosuke , Inada Yoichi , Kusama Hiroshi , Utsunomiya Hirotoshi , Oda Koji , Yokoi Tsuyoshi , Yoshizato Katsutoshi , Suzuki Hiroshi
Published: May 2007

Aim and Methods:   A decreased function of multidrug‐resistance 3 P‐glycoprotein (MDR3), limiting the rate of biliary phospholipid secretion, predisposes individuals to cholestasis and/or cholangitis. Fibrates induce the expression of mdr2 (homolog of human MDR3) in rodents. To investigate the effects of bezafibrate (BF) on the expression levels of MDR3 in cultured human hepatocytes and human livers, the amount of protein and subcellular localization of MDR3 was assessed in HepG2 cells treated with BF and humanized livers of BF‐treated chimeric mice.

Results:  In HepG2 cells, while treatment with BF did not increase the protein levels of MDR3, the treatment caused a redistribution of MDR3 in the bile canaliculi. In humanized livers of chimeric mice, oral administration of BF induced a large increase in the protein amount of MDR3 and its redistribution in the bile canaliculi. Moreover, the modulatory effects of BF on key factors involved in hepatic cholesterol and bile acid metabolism in human subjects were traced in the humanized livers of BF‐treated chimeric mice.

Conclusion:  BF causes an induction of MDR3 expression in human livers. This provides a rationale for the beneficial role of BF in improving cholestasis and/or cholangitis associated with defective MDR3 expression and function in various types of cholestatic hepatobiliary diseases.
Alpha‐fetoprotein‐specific transfer factors downregulate alpha‐fetoprotein expression and specifically induce apoptosis in Bel7402 alpha‐fetoprotein‐positive hepatocarcinoma cells
Authors: Zhang Hui , Bai Zengliang , Chen Jing , Wang Ze , Li Juan
Published: May 2007

Aim:  To investigate the mechanisms of AFP‐specific transfer factors (AFP‐TF) in induced Bel7402 cells apoptosis. Further, we investigate the interaction between AFP‐TF and AFP in the apoptosis.

Methods:  Bel7402 and HepG2 AFP‐positive hepatocarcinoma cell lines, SK‐Hep‐1 AFP‐negative hepatocarcinoma cell line and Changliver normal liver cell line are used. Cell viability is evaluated by MTT assay and apoptosis is measured by Hoechst33342 staining and TUNEL assay. FACS is used to analyze the cell cycle. AFP expression is examined by RT‐PCR, Western blotting and immunocytochemistry. The interaction between AFP‐TF and AFP in the apoptosis is investigated by addition of AFP in cultures or AFP transfection in Bel7402 cells prior to AFP‐TF treatment. Mitochondrial membrane potential (ΔΨm) and intracellular Ca2+ concentration are respectively measured by Rhodamine123 and Fluo‐3 AM Ester. Western blotting detects the involvement of several apoptosis‐related proteins. Finally, caspase‐3 and Caspase‐9 activity are respectively examined.

Results:  AFP‐TF can induce apoptosis in Bel7402 and HepG2 AFP‐positive hepatocarcinoma cells, but not SK‐Hep‐1 and Changliver cells. AFP‐mRNA level changes little in apoptotic Bel7402 cells; while AFP expression is downregulated and uniformly dispersed throughout the whole cell. Addition of exogenous AFP or overexpression of intracellular AFP can reduce such apoptotic effect. Besides, apoptotic Bel7402 cells show a disruption of ΔΨm, an immediate elevation of Ca2+ concentration, a prominently decreased ratio of bcl‐2 to bax, a release of cytochrome c from mitochondria to cytosol, and ultimately an activation of caspase‐9 and caspase‐3.

Conclusion:  AFP‐TF induced Bel7402 cells apoptosis is mitochondrial‐dependent and is mediated by the interaction of AFP‐TF with intracellular AFP.
Associated benign liver tumors in idiopathic granulomatous hepatitis: A case report
Authors: Grazi Gian Luca , Vetrone Gaetano , Ercolani Giorgio , Cescon Matteo , Ravaioli Matteo , Zanello Matteo , Corti Barbara , Pinna Antonio Daniele
Published: May 2007

We report a unique association of ruptured hepatocellular adenoma, focal nodular hyperplasia and granulomatous hepatitis in a young woman taking oral contraceptives. Diffuse granulomatous hepatitis was found in the liver parenchyma, which was associated with a large granulomatous mass of the left lobe and loco‐regional granulomatous lymphadenitis. We cannot give a full explanation of the situation, which represented a challenge in the diagnosis and in the treatment of this patient.
Inhibition of nuclear factor‐kappa B induces inflammatory cell migration and exacerbates severe liver injury in hepatitis B virus transgenic mice
Authors: Satake Shinichi , Nagaki Masahito , Kimura Kiminori , Moriwaki Hisataka
Published: May 2007

Aim:  Nuclear factor‐kappa B (NF‐κB) has a central role in co‐ordinating the expression of a wide variety of genes that control the immune response and it is also recognized as an antiapoptotic transcription factor. In this study, we focused on the role of the NF‐κB signaling pathway in liver injury induced in hepatitis B virus (HBV) transgenic mice.

Methods:  A fulminant hepatitis model was created in mice by the adoptive transfer of antigen‐specific cytotoxic T lymphocytes (CTLs) into HBV transgenic mice. We used an adenovirus expressing a mutant form of the IκB super‐repressor (Ad5IκB), an NF‐κB inhibitor, to inhibit the NF‐κB signaling pathway.

Results:  We observed that pretreatment with Ad5IκB increased the migration of inflammatory cells into the liver 6–24 h after a single intravenous injection of antigen‐specific CTLs, in comparison to pretreatment with a control adenovirus. We also demonstrated that the presence of the NF‐κB inhibitor exacerbated severe liver injury and hepatocellular apoptosis 24 h after the injection of the antigen‐specific CTLs.

Conclusion:  These results suggest that the inhibition of NF‐κB activity induces severe fulminant hepatitis in HBV transgenic mice.
Size-Dependent Elastic
State of Ellipsoidal Nano-Inclusions Incorporating Surface∕Interface
Tension
Authors: Sharma P. , Wheeler L.
T.
Published: May 2007

Using a tensor virial method of moments, an approximate solution to the relaxed elastic state of embedded ellipsoidal inclusions is presented that incorporates surface∕interface energies. The latter effects come into prominence at inclusion sizes in the nanometer range. Unlike the classical elastic case, the new results for ellipsoidal inclusions incorporating surface∕interface tension are size-dependent and thus, at least partially, account for the size-effects in the elastic state of nano-inclusions. For the pure dilatation case, exceptionally simple expressions are derived. The present work is a generalization of a previous research that addresses simplified spherical inclusions. As an example, the present work allows us, in a straightforward closed-form manner, the study of effect of shape on the size-dependent strain state of an embedded quantum dot.
New First-Order Shear Deformation Plate Theories
Authors: Shimpi R. P. , Patel H. G. , Arya H.
Published: May 2007

First-order shear deformation theories, one proposed by Reissner and another one by Mindlin, are widely in use, even today, because of their simplicity. In this paper, two new displacement based first-order shear deformation theories involving only two unknown functions, as against three functions in case of Reissner’s and Mindlin’s theories, are introduced. For static problems, governing equations of one of the proposed theories are uncoupled. And for dynamic problems, governing equations of one of the theories are only inertially coupled, whereas those of the other theory are only elastically coupled. Both the theories are variationally consistent. The effectiveness of the theories is brought out through illustrative examples. One of the theories has striking similarity with classical plate theory.
Diphenyl Furans and Aza Analogs: Effects of Structural Modification on In Vitro Activity, DNA Binding, and Accumulation and Distribution in Trypanosomes
Authors: Mathis Amanda M. , Bridges Arlene S. , Ismail Mohamed A. , Kumar Arvind , Francesconi Iris , Anbazhagan Mariappan , Hu Qiyue , Tanious Farial A. , Wenzler Tanja , Saulter Janelle , Wilson W. David , Brun Reto , Boykin David W. , Tidwell Richard R. , Hall James Edwin
Published: May 2007

Human African trypanosomiasis is a devastating disease with only a few treatment options, including pentamidine. Diamidine compounds such as pentamidine, DB75, and DB820 are potent antitrypanosomal compounds. Previous investigations have shown that diamidines accumulate to high concentrations in trypanosomes. However, the mechanism of action of this class of compounds remains unknown. A long-hypothesized mechanism of action has been binding to DNA and interference with DNA-associated enzymes. The fluorescent diamidines, DB75 and DB820, have been shown to localize not only in the DNA-containing nucleus and kinetoplast of trypanosomes but also to the acidocalcisomes. Here we investigate two series of analogs of DB75 and DB820 with various levels of in vitro antitrypanosomal activity to determine whether any correlation exists between trypanosome accumulation, distribution, and in vitro activity. Despite wide ranges of in vitro antitrypanosomal activity, all of the compounds investigated accumulated to millimolar concentrations in trypanosomes over a period of 8 h. Interestingly, some of the less potent compounds accumulated to concentrations much higher than those of more potent compounds. All of the compounds were localized to the DNA-containing nucleus and/or kinetoplast, and many were also found in the acidocalcisomes. Accumulation in the nucleus and kinetoplast should be important to the mechanism of action of these compounds. The acidocalcisomes may also play a role in the mechanism of action of these compounds. This investigation suggests that the extent of accumulation alone is not responsible for killing trypanosomes and that organelle-specific accumulation may not predict in vitro activity.
Fosamprenavir plus Ritonavir Increases Plasma Ketoconazole and Ritonavir Exposure, while Amprenavir Exposure Remains Unchanged
Authors: Wire Mary B. , Ballow Charles H. , Borland Julie , Shelton Mark J. , Lou Yu , Yuen Geoffrey , Lin Jiang , Lewis Eric W.
Published: May 2007

Plasma ketoconazole (KETO), amprenavir (APV), and ritonavir (RTV) pharmacokinetics were evaluated in 15 healthy subjects after being treated with KETO at 200 mg once daily (QD), fosamprenavir (FPV)/RTV at 700/100 mg twice daily (BID), and then KETO at 200 mg QD plus FPV/RTV at 700/100 mg BID in this open-label study. The KETO area under the concentration-time curve at steady state was increased 2.69-fold with FPV/RTV. APV exposure was unchanged, and RTV exposure was slightly increased.
Pegylated Interferon Alfa-2b Monotherapy and Pegylated Interferon Alfa-2b plus Lamivudine Combination Therapy for Patients with Hepatitis B Virus E Antigen-Negative Chronic Hepatitis B
Authors: Kaymakoglu Sabahattin , Oguz Dilek , Gur Gurden , Gurel Selim , Tankurt Ethem , Ersöz Galip , Ozenirler Seren , Kalayci Cem , Poturoglu Sule , Cakaloglu Yılmaz , Okten Atilla
Published: May 2007

Forty-eight hepatitis B virus (HBV) E antigen-negative chronic hepatitis B patients received pegylated interferon alfa-2b either alone or with lamivudine for 48 weeks and were followed for an additional 24 weeks. At the end of follow-up, virological response rates (HBV DNA levels of <400 copies/ml) were similar in the monotherapy (24%) and combination therapy (26%) groups.
Location of Persisting Mycobacteria in a Guinea Pig Model of Tuberculosis Revealed by R207910
Authors: Lenaerts Anne J. , Hoff Donald , Aly Sahar , Ehlers Stefan , Andries Koen , Cantarero Luis , Orme Ian M. , Basaraba Randall J.
Published: May 2007

The lengthy chemotherapy of tuberculosis reflects the ability of a small subpopulation of
Mycobacterium tuberculosis
bacteria to persist in infected individuals. To date, the exact location of these persisting bacteria is not known. Lung lesions in guinea pigs infected with
M. tuberculosis
have striking similarities, such as necrosis, mineralization, and hypoxia, to natural infections in humans. Guinea pigs develop necrotic primary lesions after aerosol infection that differ in their morphology compared to secondary lesions resulting from hematogenous dissemination. In infected guinea pigs conventional therapy for tuberculosis during 6 weeks reduced the bacterial load by 1.7 logs in the lungs and, although this completely reversed lung inflammation associated with secondary lesions, the primary granulomas remained largely unaffected. Treatment of animals with the experimental drug R207910 (TMC207) for 6 weeks was highly effective with almost complete eradication of the bacteria throughout both the primary and the secondary lesions. Most importantly, the few remnants of acid-fast bacilli remaining after R207910 treatment were to be found extracellular, in a microenvironment of residual primary lesion necrosis with incomplete dystrophic calcification. This zone of the primary granuloma is hypoxic and is morphologically similar to what has been described for human lung lesions. These results show that this acellular rim may, therefore, be a primary location of persisting bacilli withstanding drug treatment.