bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Determination of the Rates of Precipitation of Authigenic Illite and Kaolinite in the Presence of Aqueous Oxalate and Comparison to the K/Ar Ages of Authigenic Illite in Reservoir Sandstones
Authors: Small J. S.
Published: August 2006

The importance of precipitation rate as an effective control on illite and kaolanite formation during diagenesis has been examined by measuring precipitation rates, from Al fluid concentration, in a Dickson fluid-sampling vessel at 160°-250° and 500 bars (50 MPa). These experiments are considered to be analogues of the precipitation of clays in sandstones from porewaters containing dissolved carboxylic acids, which have a transient stability and may influence aluminosilicate solubility. Precipitated illite had a lath-shaped morphology and its composition was consistent with authigenic illite in sandstones. Kaolinite formed tabular rather than vermicular shaped crystals. Kaolinite precipitation rate was two orders of magnitude faster than illite precipitation and was rate-limited by the decomposition of oxalate; kaolinite formation should be equilibrium-controlled at virtually all stages of burial. Extrapolation of illite precipitation rate to burial temperatures indicates that the first appearance of illite in a burial sequence may be kinetically controlled. A model of illite precipitation based on these experimental results has been used to predict the time required to precipitate illite during burial of a sandstone, taking into account temperature changes during burial. For northern North Sea examples, a predicted illitization threshold of -60°C occurring at 60–80 Ma corresponds to the observed initiation of authigenic illite precipitation. Times of around 2–5 Ma would be required to reach a 98% approach to equilibrium at this threshold. The main phase of illite precipitation in the northern North Sea basin is a later, hydrologically controlled event (30-50 Ma). Equilibrium would be approached in around 0.1 Ma during this phase, which is consistent with the narrow illite K/Ar age range (1-5 Ma) recorded for some sequences.
Nature of the Illitic Phase Associated with Randomly Interstratified Smectite/Illite in Soils
Authors: Laird D. A. , Nater E. A.
Published: August 2006

A dispersion-centrifugation-decantation procedure was used to isolate various particle size fractions from a sample of clay (<2 µm fraction) separated by sedimentation from the Ap horizon of a Webster soil (fine-loamy, mixed, mesic Typic Haplaquoll). The 0.02–0.06 µm size fraction was found to be enriched in an illitic phase associated with randomly interstratified smectite/illite. X-ray powder diffraction, chemical analysis, and high-resolution transmission electron microscopy confirmed that most of the illitic material in the 0.02–0.06 µm size fraction was composed of two-layer elementary illite particles with a layer charge of −0.47 per formula unit. The results demonstrate that this low-charge illitic phase can be physically separated from soil materials and that the low-charge illitic phase has chemical, morphological, and mineralogical properties that are uniquely different from those of smectite and illite.
Characterization of Colloidal Solids from Athabasca Fine Tails
Authors: Kotlyar L. S. , Deslandes Y. , Sparks B. D. , Kodama H. , Schutte R.
Published: August 2006

During processing of Athabasca oil sands, the finely divided solids form an aqueous suspension, which ultimately stabilizes as a gel-like structure retaining up to 90% of the process water. This gelling phenomenon is believed to be caused by colloidal inorganic components. Kaolinite and mica are the main crystalline minerals in these colloidal solids; swelling clays are present in only trace amounts. Non-crystalline components are more concentrated in the finer fraction of the solids. Although the surfaces of the colloidal solids are virtually free of Fe, some contamination with polar organic matter is observed.
Characterization of Tubular Chrysotile by Thermoporometry, Nitrogen Sorption, Drifts, and TEM
Authors: Titulaer Mark K. , van Miltenburg J. Cees , Jansen J. Ben H. , Geus John W.
Published: August 2006

The maximum crystal radius Rn of ice in hollow wet chrysotile tubes is established by thermoporometry to be between 2.8 and 3.2 nm, and the internal pore volume Vn of the tubes to be between 0.008 and 0.02 ml/g. The hollow tubes of chrysotile and, for comparative reasons, small plates of talc, are hydrothermally synthesized at temperatures between 563 and 600 K and at pressures between 75 and 120 hPa. Size and shape of the pores can be varied by changing the Mg/Si molar ratios in steps of 3/1.5 and 3/2 for chrysotile and 3/3.6 and 3/4 for talc. The tubular morphology of the aggregates dried at 393 K is investigated by 1) transmission electron microscopy (TEM), 2) nitrogen adsorption and desorption at 77 K, and 3) diffuse reflectance infrared fourier transformed spectroscopy (DRIFTS). The radius within the hollow tubes, Ri, is between 2.5 and 4.0 nm as measured by TEM, and between 2.8 and 3.2 nm as determined by nitrogen adsorption and desorption. The measured radii agree well with the value calculated from crystallographic data, which is smaller than 5.3 nm. Within the dried aggregates the tubes are clustered in regular patterns, in which each tube is surrounded by six other tubes. The external radius, Ro, between the clustered tubes is from 1.6 to 2.9 nm as observed by TEM, and from 1.8 to 2.3 nm by N2 adsorption and desorption. The external radius is not measured by thermoporometry. Where thermoporometry only measures the average pore size and pore volume within the tubes, TEM and N2 adsorption and desorption additionally provide the corresponding values between the tubes. A third pore radius, 5 to 20 nm between the clusters of chrysotile tubes, is established with N2 adsorption and desorption.
Residual Manganese(II) Entrapped in Single-Layer-Hydrate Montmorillonite Interlayers
Authors: Gehring A. U. , Fry I. V. , Lloyd T. , Sposito G.
Published: August 2006

Electron paramagnetic resonance (EPR) and Fourier transform infrared (FTIR) spectroscopy in combination with X-ray diffractometry and thermal methods were used to determine the coordination of residual exchangeable Mn(II) in an untreated sample of Wyoming montmorillonite. At room temperature, Mn(II) in a single-layer-hydrate interlayer was proposed to be coordinated directly with oxygen ions of the siloxane surface on one layer and to form water bridges to the oxygens on the siloxane surface of the opposite layer. Dehydration and collapse of the interlayer entrapped and thereby stabilized the partially solvated Mn(II) up to 600°C. A change to Mn(II) in highly symmetric coordination occurred during dehydroxylation of the montmorillonite structure between 600°C and 700°C. Manganese(II) remained coordinated at the surface but positioned in a bicapped trigonal antiprism formed by oxygens of the silicate structure. This coordination was metastable at 800°C when the structural decomposition of the clay mineral began.
Isothermal Treatments of Regularly Interstratified Montmorillonite-Beidellite at Hydrothermal Conditions
Authors: Yamada Hirohisa , Nakazawa Hiromoto
Published: August 2006

A glass in the intermediate composition of montmorillonite and beidellite, 50/50 in mole ratio, was treated under a hydrothermal pressure of 100 MPa, in the temperature range from 250 to 500°C and durations from 2 to 129 days. The phases identified in the products were plotted in a time-temperature-transformation (TTT) diagram. The TTT diagram showed that the regularly interstratified montmorillonite-beidellite (r.i.M-B) was a metastable phase above the temperature of 350°C and changed to the assemblage of Na-rectorite + saponite + quartz, through the intermediate assemblage of beidellite + saponite + quartz. The TTT diagram suggested also that the r.i.M-B might be a stable clay mineral below the temperature of 300°C in the middle region of montmorillonite-beidellite pseudo-binary system, although the laboratory confirmation of the mineral stability was not easy for the sluggish reaction.
Synthesis and CO2 Adsorption Features of a Hydrotalcite-Like Compound of the Mg2+-Al3+-Fe(CN)64- System with High Layer-Charge Density
Authors: Mao Gang , Tsuji Masamichi , Tamaura Yutaka
Published: August 2006

Hydrotalcite-like compounds (HT) with 24%–48% Al3+-substitution have been synthesized in the Mg2+-Al3+-Fe(CN)64- system. Conditioning of the synthesized and air-dried compound with K4Fe(CN)64- solution at 80°C was essential to obtain the 80%–90% pure ionic Fe(CN)64- form on an equivalent basis. A linear decrease in ao with an increase in the mole ratio of R = Al3+/(Mg2+ + Al3+) was extended to R = 0.48. The formation of highly Al3+-substituted HTs has been corroborated by the decrease in the hexagonal lattice constant ao down to 3.016 Å. The ao value was independent of the interlayer anions. The CO2 adsorption profiles were dependent upon both the Al3+-substitution and the interlayer distance. The isosteric heat of CO2 adsorption was 43.3 kJ mol-1 in the range of adsorption of 20 to 40 cm3 g-1 at 298 K and 0.1 MPa.
Briefing: Work begins on Barnsley Town ‘Gateway’
Authors: Thomas C. , Ailward C.
Published: August 2006

Barnsley Transport Interchange is the first project to be initiated as part of the Remaking Barnsley regeneration programme. The interchange is also intended to fit with Yorkshire Forward's masterplan vision for the regeneration of Barnsley over the next 30 years. The design of the £24·5 million bus and rail interchange is modern, sustainable and will improve access to the town. The design incorporates a transparent ethylene tetra-fluoro-ethylene membrane canopy requiring minimal steel framework suspended on glu-laminated timber columns and extensive use of pre-patinated copper. Leading edge design techniques have been used including advanced three-dimensional modelling.
Predicting long-term soaked CBR of gypsiferous subgrade soils
Authors: Razouki S. S. , Kuttah D. K.
Published: August 2006

Thirty-two laboratory California Bearing Ratio (CBR) tests were carried out on a CH gypsiferous subgrade soil with an initial gypsum content of 34%. The soil samples were prepared according to ASTM D 1883-99 at 95% of the maximum modified AASHTO dry density. For each 40 lb (178 N) and 70 lb (311·5 N) surcharge load, eight pairs of CBR samples were prepared, and soaked for periods of 0, 4, 7, 15, 30, 60, 120 and 180 days respectively. To develop a general empirical formula for predicting long-term soaked CBR from unsoaked CBR, use was made of available results on CH soil with a gypsum content of 15%, on granular gypsiferous soils of the SW-SM group with a gypsum content of 64%, and on SM soils with gypsum contents of 34% and 61%. The empirical equation developed in this paper enables the soaked CBR to be determined from the unsoaked CBR for all types of gypsiferous soil and for any surcharge load and soaking period. The equation's validity was examined using six different gypsiferous soils (eight case studies) including both granular and fine-grained soils. This paper also shows the invalidity of Fekpe's empirical equation in modelling the long-term behaviour of gypsiferous soils.
Evaluation of Model Complexity and Input Uncertainty of Field‐Scale Water Flow and Salt Transport
Authors: Schoups G. , Hopmans J. W.
Published: August 2006

Prediction of large‐scale vadose zone water flow and salt transport is affected by errors due to uncertainties in model structure, that is, complexity of representation of hydrologic processes and model input uncertainties such as parameter values, boundary conditions, and initial conditions. Selection of an appropriate level of model complexity must consider these two sources of uncertainty. We illustrate this selection process for the prediction of field‐scale crop transpiration and salt drainage in irrigated agriculture given a limited number of point‐scale measurements. Various levels of model input uncertainty in hydraulic properties and infiltration rates are considered, representative of a range of spatial heterogeneities. Model complexity is defined relative to a “true” model, in terms of the level of spatial and temporal averaging used in the approximate model. This set‐up allows for the separation of the total model error into different terms representing the model input error and the structural model error. Results show that the relative contribution of structural model error to the total model error decreases as spatial heterogeneity or uncertainty in the model input increases. Model input uncertainty may be reduced by taking a larger number of point‐scale measurements. Our analysis further illustrates that there exists an optimal trade‐off between model complexity and model input uncertainty. It suggests that complex models may be replaced by more simple ones as long as the resulting structural model error is smaller than the prediction errors due to input uncertainty. The methodology provides a straightforward and objective approach to identifying an optimal level of model complexity as a function of the degree of field‐scale heterogeneity and data availability.
Expression of Hypothalamic KiSS-1 System and Rescue of Defective Gonadotropic Responses by Kisspeptin in Streptozotocin-Induced Diabetic Male Rats
Authors: Castellano Juan M. , Navarro Victor M. , Fernández-Fernández Rafael , Roa Juan , Vigo Eva , Pineda Rafael , Dieguez Carlos , Aguilar Enrique , Pinilla Leonor , Tena-Sempere Manuel
Published: August 2006

Hypogonadotropism is a common feature of uncontrolled diabetes, for which the ultimate mechanism remains to be elucidated. Kisspeptins, ligands of G protein–coupled receptor 54 (GPR54) encoded by the KiSS-1 gene, have recently emerged as major gatekeepers of the gonadotropic axis. Alteration in the hypothalamic KiSS-1 system has been reported in adverse metabolic conditions linked to suppressed gonadotropins, such as undernutrition. However, its potential contribution to defective gonadotropin secretion in diabetes has not been evaluated. We report herein analyses of luteinizing hormone (LH) responses to kisspeptin and hypothalamic expression of the KiSS-1 gene in streptozotocin (STZ)-induced diabetic male rats. In addition, functional studies involving kisspeptin replacement or continuous administration of leptin and insulin to diabetic male rats are presented. Kisspeptin administration evoked robust LH and testosterone bursts and enhanced postgonadectomy LH concentrations, despite prevailing attenuation of gonadotropic axis in diabetic animals. In addition, hypothalamic KiSS-1 mRNA levels were unambiguously decreased in diabetic male rats, and the postorchidectomy rise in KiSS-1 mRNA was severely blunted. Repeated administration of kisspeptin to diabetic rats evoked persistent LH and testosterone responses and partially rescued prostate and testis weights. In addition, central infusion of leptin, but not insulin, was sufficient to normalize hypothalamic KiSS-1 mRNA levels, as well as LH and testosterone concentrations. In summary, we provide evidence for altered expression of the hypothalamic KiSS-1 system in a model of uncontrolled diabetes. This observation, together with the ability of exogenous kisspeptin to rescue defective LH responses in diabetic rats, unravel the physiopathological implication, and potential therapeutic intervention, of the KiSS-1 system in altered gonadotropin secretion of type 1 diabetes.
Aging Correlates With Decreased β-Cell Proliferative Capacity and Enhanced Sensitivity to Apoptosis
Authors: Maedler Kathrin , Schumann Desiree M. , Schulthess Fabienne , Oberholzer José , Bosco Domenico , Berney Thierry , Donath Marc Y.
Published: August 2006

Type 2 diabetes is characterized by a deficit in β-cell mass, and its incidence increases with age. Here, we analyzed β-cell turnover in islets from 2- to 3- compared with 7- to 8-month-old rats and in human islets from 53 organ donors with ages ranging from 17 to 74 years. In cultured islets from 2- to 3-month-old rats, the age at which rats are usually investigated, increasing glucose from 5.5 to 11.1 mmol/l decreased β-cell apoptosis, which was augmented when glucose was further increased to 33.3 mmol/l. In parallel, β-cell proliferation was increased by both 11.1 and 33.3 mmol/l glucose compared with 5.5 mmol/l. In contrast, in islets from 7- to 8-month-old rats and from adult humans, increasing glucose concentrations from 5.5 to 33.3 mmol/l induced a linear increase in β-cell death and a decrease in proliferation. Additionally, in cultivated human islets, age correlated positively with the sensitivity to glucose-induced β-cell apoptosis and negatively to baseline proliferation. In rat islets, constitutive expression of Fas ligand and glucose-induced Fas receptor expression were observed only in 7- to 8-month-old but not in 2- to 3-month-old islets, whereas no age-dependent changes in the Fas/Fas ligand system could be detected in human islets. However, pancreatic duodenal homeobox (PDX)-1 expression decreased with age in pancreatic tissue sections of rats and humans. Furthermore, older rat islets were more sensitive to the high-glucose–mediated decrease in PDX-1 expression than younger islets. Therefore, differences in glucose sensitivity between human and 2- to 3-month-old rat islets may be due to both differences in age and in the genetic background. These data provide a possible explanation for the increased incidence of type 2 diabetes at an older age and support the use of islets from older rats as a more appropriate model to study glucose-induced β-cell apoptosis.
Variation Within the Gene Encoding the Upstream Stimulatory Factor 1 Does Not Influence Susceptibility to Type 2 Diabetes in Samples From Populations With Replicated Evidence of Linkage to Chromosome 1q
Authors: Zeggini Eleftheria , Damcott Coleen M. , Hanson Robert L. , Karim Mohammad A. , Rayner N. William , Groves Christopher J. , Baier Leslie J. , Hale Terri C. , Hattersley Andrew T. , Hitman Graham A. , Hunt Sarah E. , Knowler William C. , Mitchell Braxton D. , Ng Maggie C.Y. , O’Connell Jeffrey R. , Pollin Toni I. , Vaxillaire Martine , Walker Mark , Wang Xiaoqin , Whittaker Pamela , Xiang Kunsan , Jia Weiping , Chan Juliana C. N. , Froguel Philippe , Deloukas Panos , Shuldiner Alan R. , Elbein Steven C. , McCarthy Mark I. ,   for the International Type 2 Diabetes 1q Consortium
Published: August 2006

The gene encoding the transcription factor upstream stimulatory factor (USF)1 influences susceptibility to familial combined hyperlipidemia (FCHL) and triglyceride levels. Phenotypic overlap between FCHL and type 2 diabetes makes USF1 a compelling positional candidate for the widely replicated type 2 diabetes linkage signal on chromosome 1q. We typed 22 variants in the F11R/USF1 region (1 per 3 kb), including those previously implicated in FCHL-susceptibility (or proxies thereof) in 3,726 samples preferentially enriched for 1q linkage. We also examined glucose- and lipid-related continuous traits in an overlapping set of 1,215 subjects of European descent. There was no convincing evidence for association with type 2 diabetes in any of seven case-control comparisons, individually or combined. Family-based association analyses in 832 Pima subjects were similarly negative. At rs3737787 (the variant most strongly associated with FCHL), the combined odds ratio, per copy of the rarer A-allele, was 1.10 (95% CI 0.97–1.24, P = 0.13). In 124 Utah subjects, rs3737787 was significantly associated (P = 0.002) with triglyceride levels, but direction of this association was opposite to previous reports, and there was no corroboration in three other samples. These data exclude USF1 as a major contributor to type 2 diabetes susceptibility and the basis for the chromosome 1q linkage. They reveal only limited evidence for replication of USF1 effects on continuous metabolic traits.
Cytotoxic T-Cells From T-Cell Receptor Transgenic NOD8.3 Mice Destroy β-Cells via the Perforin and Fas Pathways
Authors: Dudek Nadine L. , Thomas Helen E. , Mariana Lina , Sutherland Robyn M. , Allison Janette , Estella Eugene , Angstetra Eveline , Trapani Joseph A. , Santamaria Pere , Lew Andrew M. , Kay Thomas W.H.
Published: August 2006

Cytotoxic T-cells are the major mediators of β-cell destruction in type 1 diabetes, but the molecular mechanisms are not definitively established. We have examined the contribution of perforin and Fas ligand to β-cell destruction using islet-specific CD8+ T-cells from T-cell receptor transgenic NOD8.3 mice. NOD8.3 T-cells killed Fas-deficient islets in vitro and in vivo. Perforin-deficient NOD8.3 T-cells were able to destroy wild-type but not Fas-deficient islets in vitro. These results imply that NOD8.3 T-cells use both pathways and that Fas is required for β-cell killing only when perforin is missing. Consistent with this theory, transgenic NOD8.3 mice with β-cells that do not respond to Fas ligation were not protected from diabetes. We next investigated the mechanism of protection provided by overexpression of suppressor of cytokine signaling-1 (SOCS-1) in β-cells of NOD8.3 mice. SOCS-1 islets remained intact when grafted into NOD8.3 mice and were less efficiently killed in vitro. However, addition of exogenous peptide rendered SOCS-1 islets susceptible to 8.3 T-cell–mediated lysis. Therefore, NOD8.3 T-cells use both perforin and Fas pathways to kill β-cells and the surprising blockade of NOD8.3 T-cell–mediated β-cell death by SOCS-1 overexpression may be due in part to reduced target cell recognition.
Diabetes, Inflammation, and Functional Decline in Older Adults
Authors: Figaro M. Kathleen , Kritchevsky Stephen B. , Resnick Helaine E. , Shorr Ronald I. , Butler Javed , Shintani Ayumi , Penninx Brenda W. , Simonsick Eleanor M. , Goodpaster Bret H. , Newman Anne B. , Schwartz Ann V. , Harris Tamara B. ,   for the Health Aging and Body Composition study
Published: August 2006

OBJECTIVE—Age, diabetes, and elevated inflammatory markers independently increase the risk of functional decline. We examined the effect of C-reactive protein (CRP) and interleukin-6 (IL-6) on the incident mobility limitation in older adults with and without diabetes.

RESEARCH DESIGN AND METHODS—We analyzed data from a cohort of 2,895 well-functioning adults aged 70–79 years, followed for development of persistent functional limitation over 3.5 years. Participants were assessed for the presence of diabetes according to fasting glucose and/or hypoglycemic medication use and were divided into three equal groups (tertiles) according to level of CRP or IL-6. Persistent functional limitation was defined as difficulty climbing 10 steps or walking one-quarter mile on two consecutive semiannual assessments.

RESULTS—At baseline, 702 participants (24%) had diabetes. CRP values were (median ± SD) 2.8 ± 4.4 versus 3.7 ± 5.4 for those with normal glucose and diabetes, respectively (P < 0.001). The unadjusted incidence of functional limitation associated with increased levels of CRP and IL-6 was greater among participants with diabetes. After adjusting for clinical and demographic covariates, persistent functional limitation for the highest tertile was greater compared with that for the lowest tertile of CRP or IL-6 for those with and without diabetes. CRP hazard ratios (HRs) were 1.7 (95% CI 1.2–2.3) versus 1.4 (1.1–1.6), respectively. IL-6 HRs were 1.8 (1.3–2.5) versus 1.6 (1.4–2.0), respectively.

CONCLUSIONS—In initially high-functioning older adults, those with diabetes and higher inflammatory burden had an increased risk of functional decline. Interventions at early stages to reduce inflammation may preserve function in these individuals.
Erythropoietin Is Expressed in the Human Retina and It Is Highly Elevated in the Vitreous Fluid of Patients With Diabetic Macular Edema
Authors: Hernández Cristina , Fonollosa Alex , García-Ramírez Marta , Higuera Mónica , Catalán Roberto , Miralles Adela , García-Arumí José , Simó Rafael
Published: August 2006

OBJECTIVE—Erythropoietin has been recently found to be increased in the vitreous fluid from ischemic retinal diseases such as proliferative diabetic retinopathy (PDR). The aims of the present study were 1) to measure erythropoietin levels in the vitreous fluid from patients with diabetic macular edema (DME), a condition in which the ischemia is not a predominat event, and 2) to compare erythropoietin mRNA expression between human retinas from nondiabetic and diabetic donors without retinopathy.

RESEARCH DESIGN AND METHODS—Vitreous samples from 12 type 2 diabetic patients with DME without significant retinal ischemia and 12 PDR patients were prospectively analyzed. Ten nondiabetic patients with macular holes served as the control group. Erythropoietin was assessed by radioimmunoassay (milliunits per milliliter). Erythropoietin mRNA expression was measured by quantitative real-time RT-PCR analysis in the retina from eight nondiabetic and eight age-matched diabetic donors without diabetic retinopathy

RESULTS—Intravitreal erythropoietin concentration was higher in both PDR and DME patients than in nondiabetic control subjects (PDR vs. control subjects: median 302 [range 117–1,850] vs. 30 mU/ml [10–75], P < 0.01; DME vs. control subjects: 430 [41–3,000] vs. 30 mU/ml [10–75], P < 0.01). However, no significant differences were found between DME and PDR patients. Erythropoietin mRNA expression was detected in the human retina, and it was higher in the retina from diabetic than from nondiabetic donors.

CONCLUSIONS—As occurs in PDR, intravitreous erythropoietin concentrations are strikingly higher in DME. Erythropoietin is expressed in the human retina, and it is upregulated in diabetic patients even without retinopathy. These findings suggest that other factors apart from ischemia are involved in the overexpression of erythropoietin in diabetic retinopathy.
Elevated fibrinogen fragment levels in uremic plasma inhibit platelet function and expression of glycoprotein IIb‐IIIa
Authors: Thekkedath Usha R. , Chirananthavat Thanit , Leypoldt John K. , Cheung Alfred K. , Mohammad Syed F.
Published: August 2006

Hemostatic dysfunction is frequently noted in uremia, but the mechanisms responsible for it are poorly understood and are assumed to be multifactorial. Preliminary findings from our laboratory suggest that elevated levels of circulating fibrinogen fragments (FF) might contribute to the hemostatic defect in uremic patients. Defibrinated plasma obtained from chronic hemodialysis (HD) patients as well as normal subjects were examined by SDS‐PAGE and immunoblotting and quantified by an immunoassay. In addition, endogenous FF isolated from normal and uremic plasma using affinity chromatography were examined by flow cytometry for their effect on glycoprotein (GP) IIb‐IIIa receptor expression and tested for their ability to inhibit platelet aggregation. The mean FF concentration in uremic plasma (1.14 ± 0.85 mg/ml) was noted to be eight times greater than in normal plasma (0.15 ± 0.01 mg/ml) (P < 0.05). Moreover, the mean FF level decreased by 48.25% following HD (from 1.14 ± 0.85 mg/ml to 0.59 ± 0.33 mg/ml; P < 0.05). SDS‐PAGE and immunoblotting experiments showed that the decrease was observed in both medium‐sized (20–60 kDa) as well as large (>100 kDa) FF. Further, FF isolated from uremic plasma inhibited platelet aggregation by (46.8 ± 18.1)% (P < 0.05) and the GP IIb‐IIIa receptor expression by (28.0 ± 7.6)% (P < 0.05 vs. control). The results show that (1) FF levels are elevated in uremic plasma, (2) HD results in significant decrease in FF and (3) endogenous FF inhibit platelet function, presumably via competitive binding to the fibrinogen receptor GP IIb‐IIIa. The decrease in plasma levels of FF > 100 kDa following HD suggests that adsorption to the dialysis membrane contributes to their removal. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Inherited thrombophilia is associated with deep vein thrombosis in a Colombian population
Authors: Torres J.D. , Cardona H. , Álvarez L. , Cardona‐Maya W. , Castañeda S.A. , Quintero‐Rivera F. , Cadavid A. , Bedoya G. , Tobón L.
Published: August 2006

The development of venous thromboembolism is influenced by a variety of genetic and environmental risk factors. A few studies have ascertained whether thrombophilic defects are risk factors for venous thromboembolism in Latin American populations with a variable degree of admixture, such as the Colombian population. To address this issue, we conducted a case–control study involving 100 consecutive patients with deep vein thrombosis and 114 healthy controls from the Hospital Universitario San Vicente de Paúl, Medellín, Colombia. Activated protein C resistance (APC resistance) was detected in 25/99 patients vs. 6/114 controls (OR = 6.08, 95% CI = 2.23–17.47). Ten of 100 patients carried the factor V Leiden mutation vs. 1/114 controls (OR = 12.56, 95% CI = 1.61–267). APC resistance was associated with the factor V Leiden mutation in only 10/25 patients. The prothrombin G20210A mutation was found in 4/100 patients, but none of the controls (P < 0.05). There was no significant difference in the proportion of homozygous carriers of methylenetetrahydrofolate reductase C677T variant among patients and controls. In conclusion, in our studied population, factor V Leiden, APC resistance, and prothrombin G20210A were associated with an increased risk of deep vein thrombosis. However, the frequencies of these thrombophilic defects and of APC resistance associated with factor V Leiden was lower than the corresponding frequencies previously reported for Caucasian populations. Further study is required to assess the influence of ethnicity on thrombophilia. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
A genome‐wide linkage search for bipolar disorder susceptibility loci in a large and complex pedigree from the eastern part of Cuba
Authors: Marcheco‐Teruel B. , Flint T.J. , Wikman F.P. , Torralbas M. , González L. , Blanco L. , Tan Q. , Ewald H. , Orntoft T. , Kruse T.A. , Børglum A.D. , Mors O.
Published: August 2006

We present results from a genome‐wide scan of a six generation pedigree with 28 affected members with apparently dominant bipolar I disorder from eastern Cuba. Genotypes were obtained using the early access version of the Genechip Mapping 10K Xba array from AFFYMETRIX. Parametric and non‐parametric linkage analyses under dominant and recessive models were performed using GENEHUNTER v2.1r5. Two phenotypic models were included in the analyses: bipolar I disorder and recurrent depressive disorder, or bipolar I disorder only. LOD scores were calculated for the entire family combined, and for four subdivisions of the family. For the entire family a suggestive parametric LOD score was obtained under the dominant model and the broader phenotype at 14q11.2‐12 (LOD = 2.05). In the same region, a non‐parametric LOD score close to genome‐wide significance was also obtained, based on the entire family (NPL = 7.31,P‐value = 0.07). For two individual branches of the pedigree, genome‐wide significance (P < 0.005) was obtained with NPL scores of 8.71 and 12.99, respectively, also in the same region on chromosome 14. Chromosome 5q21.3‐22.3 also showed close to genome‐wide significant linkage for the complete pedigree (NPL = 7.26,P = 0.07), also supported by significant linkage in one individual branch (NPL = 9.86,P < 0.005). In addition, genome‐wide significant nonparametric results (P‐values <0.005) were obtained for individual branches at 5p13.1‐q12.3, 6p22.3, 8q13.3‐21.13, and 10q22.3‐23.32. Finally, 2p25.1‐25.3, 2p13.3‐14, 3p14.2, 6p22.3‐24.1, 7p14.1‐14.2, 8q12.2‐12.3, 10q21.1‐21.2, 14q13.1‐21.1, 15q15.1‐21.2, and 22q12.3‐13.32 showed suggestive linkage in the complete family. Most of these potential susceptibility loci overlap with, or are close, to previous linkage findings. The locus on 5q may, however, represent a novel susceptibility locus. © 2006 Wiley‐Liss, Inc.
Absence of association with DAT1 polymorphism and response to methylphenidate in a sample of adults with ADHD
Authors: Mick Eric , Biederman Joseph , Spencer Thomas , Faraone Stephen V. , Sklar Pamela
Published: August 2006

A polymorphism in the dopamine transporter gene (DAT1) has been previously associated with ADHD and methylphenidate has been hypothesized to block the dopamine transporter. The goal of this study was to examine whether a 40‐bp variable number of tandem repeats (VNTR) of DAT1 moderate response and adverse effects associated with methylphenidate treatment of adults with ADHD. Subjects were 106 adults with ADHD enrolled in 6‐week randomized placebo‐controlled parallel design trials of methylphenidate (OROS and immediate release preparations). There was no evidence of an association between DAT1 VNTR and response to methylphenidate (F(2,100) = 0.04, P = 0.9). Similarly, there was no pattern of statistically significant association with DAT1 VNTR and cardiovascular or spontaneously reported adverse effects. We failed to identify an association with DAT1 and the response or tolerability of methylphenidate in adults with ADHD. © 2006 Wiley‐Liss, Inc.
Possible role of preproghrelin gene polymorphisms in susceptibility to bulimia nervosa
Authors: Ando Tetsuya , Komaki Gen , Naruo Tetsuro , Okabe Kenjiro , Takii Masato , Kawai Keisuke , Konjiki Fujiko , Takei Michiko , Oka Takakazu , Takeuchi Kaori , Masuda Akinori , Ozaki Norio , Suematsu Hiroyuki , Denda Kenzo , Kurokawa Nobuo , Itakura Kotarou , Yamaguchi Chikara , Kono Masaki , Suzuki Tatsuyo , Nakai Yoshikatsu , Nishizono‐Maher Aya , Koide Masanori , Murakami Ken , Nagamine Kiyohide , Tomita Yuichiro , Ookuma Kazuyoshi , Tomita Kazumi , Tonai Eita , Ooshima Akira , Ishikawa Toshio , Ichimaru Yuhei
Published: August 2006

Previous investigations have suggested that ghrelin, an endogenous orexigenic peptide, is involved in the pathology of eating disorders. We conducted a study to determine whether any preproghrelin gene polymorphisms are associated with eating disorders. Three hundred thirty‐six eating disorder patients, including 131 anorexia nervosa (AN)‐restricting types (AN‐R), 97 AN‐binge eating/purging types (AN‐BP) and 108 bulimia nervosa (BN)‐purging types (BN‐P), and 300 healthy control subjects participated in the study. Genotyping was performed to determine the polymorphisms present, and with this information, linkage disequilibrium (LD) between the markers was analyzed and the distributions of the genotypes, the allele frequencies, and the haplotype frequencies were compared between the groups. The Leu72Met (408 C > A) (rs696217) polymorphism in exon 2 and the 3056 T > C (rs2075356) polymorphism in intron 2 were in LD (D′ = 0.902, r2 = 0.454). Both polymorphisms were significantly associated with BN‐P (allele‐wise: P = 0.0410, odds ratio (OR) = 1.48; P = 0.0035, OR = 1.63, for Leu72Met and 3056 T > C, respectively). In addition, we observed a significant increase in the frequency of the haplotype Met72‐3056C in BN‐P patients (P = 0.0059, OR = 1.71). Our findings suggest that the Leu72Met (408 C > A) and the 3056 T > C polymorphisms of the preproghrelin gene are associated with susceptibility to BN‐P. © 2006 Wiley‐Liss, Inc.
Association between the interleukin‐1 receptor antagonist gene and negative symptom improvement during antipsychotic treatment†
Authors: Mata Ignacio , Crespo‐Facorro Benedicto , Pérez‐Iglesias Rocío , Carrasco‐Marín Eugenio , Arranz Maria Jesús , Pelayo‐Terán José Maria , Leyva‐Cobían Francisco , Vázquez‐Barquero José Luis
Published: August 2006

The contribution of immune system to schizophrenia has been an important area of focus in schizophrenia research. Several genetic variants in the cytokine system have been associated with the pathogenesis of schizophrenia. The purpose of this study was to determine whether a pharmacogenetic relationship exists between a variable number of tandem repeats (VNTR) polymorphism in the interleukin‐1 receptor antagonist gene (IL‐1RN) and clinical improvement during antipsychotic treatment in patients with a first non‐affective psychotic episode. One hundred and fifty‐four subjects presenting with a first non‐affective psychotic episode were randomly assigned to treatment with haloperidol, risperidone, or olanzapine and rated with the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS) both at baseline and after 6 weeks of treatment. A control sample of 336 blood bank donors was also included. No differences in genotype or allele distributions were found between patients and controls. However, after controlling for baseline SANS scores, the genotype in the VNTR polymorphism in the IL‐1RN gene significantly predicted negative symptom improvement, accounting for approximately 7% of the variance (F = 5.23, df = 2, P = 0.006). The mean decrease in SANS scores was 58% for the IL‐1RN* 2/2, 44% for the IL‐1RN* 1/2, and 14% for the IL‐1RN* 1/1 subjects, respectively. These results suggest that the VNTR polymorphism in the IL‐1RN gene may be a useful predictor of negative symptom improvement in schizophrenic patients treated with antipsychotic drugs. © 2006 Wiley‐Liss, Inc.
Are raw RSS feeds suitable for broad issue scanning? A science concern case study
Authors: Thelwall Mike , Prabowo Rudy , Fairclough Ruth
Published: August 2006

Broad issue scanning is the task of identifying important public debates arising in a given broad issue; really simple syndication (RSS) feeds are a natural information source for investigating broad issues. RSS, as originally conceived, is a method for publishing timely and concise information on the Internet, for example, about the main stories in a news site or the latest postings in a blog. RSS feeds are potentially a nonintrusive source of high‐quality data about public opinion: Monitoring a large number may allow quantitative methods to extract information relevant to a given need. In this article we describe an RSS feed‐based coword frequency method to identify bursts of discussion relevant to a given broad issue. A case study of public science concerns is used to demonstrate the method and assess the suitability of raw RSS feeds for broad issue scanning (i.e., without data cleansing). An attempt to identify genuine science concern debates from the corpus through investigating the top 1,000 “burst” words found only two genuine debates, however. The low success rate was mainly caused by a few pathological feeds that dominated the results and obscured any significant debates. The results point to the need to develop effective data cleansing procedures for RSS feeds, particularly if there is not a large quantity of discussion about the broad issue, and a range of potential techniques is suggested. Finally, the analysis confirmed that the time series information generated by real‐time monitoring of RSS feeds could usefully illustrate the evolution of new debates relevant to a broad issue.
Detection of Cryptosporidium parvum oocysts using a microfluidic device equipped with the SUS micromesh and FITC‐labeled antibody
Authors: Taguchi Tomoyuki , Arakaki Atsushi , Takeyama Haruko , Haraguchi Satoshi , Yoshino Masato , Kaneko Masao , Ishimori Yoshio , Matsunaga Tadashi
Published: August 2006

Development of a microfluidic device equipped with micromesh for detection of Cryptosporidium parvum oocyst was reported. A micromesh consisting of 10 × 10 cavities was microfabricated on the stainless steel plate by laser ablation. Each cavity size, approximately 2.7 µm in diameter, was adopted to capture a single C. parvum oocyst. Under negative pressure operation, suspensions containing microbeads or C. parvum oocysts flowed into the microchannel. Due to strong non‐specific adsorption of microbeads onto the PDMS microchannel surface during sample injection, the surface was treated with air plasma, followed by treatment with 1% sodium dodecyl sulfate (SDS) solution. This process reduced the non‐specific adsorption of microbeads on the microchannel to 10% or less in comparison to a non‐treated microchannel. This microfluidic device equipped with the SUS micromesh was further applied for the capture of C. parvum oocysts. Trapped C. parvum oocysts were visualized by staining with FITC‐labeled anti‐C. parvum oocyst antibody on a micromesh and counted under fluoroscopic observation. The result obtained by our method was consistent with that obtained by direct immunofluorescence assay coupled with immunomagnetic separation (DFA‐IMS) method, indicating that the SUS micromesh is useful for counting of C. parvum oocysts. The newly designed microfluidic device exploits a geometry that allowed for the entrapment of oocysts on the micromesh while providing the rapid introduction of a series of reagents and washes through the microfluidic structure. Our data indicate that this microfluidic device is useful for high‐throughput counting of C. parvum oocysts from tap water sample. Biotechnol. Bioeng. 2007;96: 272–280. © 2006 Wiley Periodicals, Inc.
Alkaline‐cell lysis through in‐line static mixer reactor for the production of plasmid DNA for gene therapy
Authors: Chamsart Saethawat , Karnjanasorn Tanyawat
Published: August 2006

A state‐of‐the‐art in‐line static mixer reactor (ISMR) was invented to lyse E. coli cells and neutralize the cell lysate continuously and efficiently for the extraction of plasmid DNA. It comprised two connected static dynamic mixers, each 0.01 m in diameter and 0.9 m in length, one for lysis and one for neutralization. Cells were lysed using concentrated alkaline with 1% SDS and the lysate was neutralized at feed rates of cell suspension:lysis solution:neutralization solution of 125:250:125, 250:500:250, and 500:1,000:500 mL/min. Distances for the mixtures to reach color homogeneity were dependent on feed rates. The higher the feed rates the shorter the mixing distances and times. However, complete cell lysis and neutralization were independent of color homogeneity. Lysate viscosity and neutralized floc size decreased and floc density increased, as distances and feed rates increased. High plasmid yields were obtained from both lysis and neutralization at feed rate ratios of 125:250:125 and 250:500:250 mL/min within mixing distances ≤0.6 m. Poor mixing performance and plasmid yield were obtained at a high feed rate of 500:1,000: 500 mL/min when residence and reaction times were less than 2 s and from mixing distances ≥0.6 m at all feed rates due to a longer exposure to strong alkali and shear flow. This invention showed excellent performance with scaleable potential for the commercial manufacture of plasmid DNA. Biotechnol. Bioeng. 2007;96: 471–482. © 2006 Wiley Periodicals, Inc.
Microparticle adhesive dynamics and rolling mediated by selectin‐specific antibodies under flow
Authors: Ham Anthony Sang Won , Goetz Douglas J. , Klibanov Alexander L. , Lawrence Michael B.
Published: August 2006

In vitro studies were performed to characterize the relative performance of candidate receptors to target microparticles to inflammatory markers on vascular endothelium. To model the interactions of drug‐bearing microparticles or imaging contrast agents with the vasculature, 6 micron polystyrene particles bearing antibodies, peptides, or carbohydrates were perfused over immobilized E‐ or P‐selectin in a flow chamber. Microparticles conjugated with HuEP5C7.g2 (HuEP), a monoclonal antibody (mAb) specific to E‐ and P‐selectin, supported leukocyte‐like rolling and transient adhesion at venular shear rates. In contrast, microparticles conjugated with a higher affinity mAb specific for P‐selectin (G1) were unable to form bonds at venular flow rates. When both HuEP and G1 were conjugated to the microparticle, HuEP supported binding to P‐selectin in flow which allowed G1 to form bonds leading to stable adhesion. While the microparticle attachment and rolling performance was not as stable as that mediated by the natural ligands P‐selectin Glycoprotein Ligand‐1 or sialyl Lewisx, HuEP performed significantly better than any previously characterized mAb in terms of mediating microparticle binding under flow conditions. HuEP may be a viable alternative to natural ligands to selectins for targeting particles to inflamed endothelium. Biotechnol. Bioeng. 2007;96: 596–607. © 2006 Wiley Periodicals, Inc.
Optimal design of non‐Newtonian, micro‐scale viscous pumps for biomedical devices
Authors: da Silva A.K. , Kobayashi M.H. , Coimbra C.F.M.
Published: August 2006

The present paper addresses the numerical optimization of geometrical parameters of non‐Newtonian micro‐scale viscous pumps for biomedical devices. The objective is to maximize the mass flow rate per unit of shaft power consumed by the rotor when an external pressure load is applied along the channel that houses the rotor. Two geometric parameters are considered in the optimization process: (i) the height of the channel that houses the rotor (H) and (ii), the eccentricity (ε) of the rotor. Three different micro‐scale viscous pump configurations were tested: a straight‐housed pump (I‐shaped housing) and two curved housed pumps (L‐ and U‐shaped housings). The stress–strain constitutive law is modeled by a power‐law relation. The results show that the geometric optimization of micro‐scale viscous pumps is critical since the mass flow rate propelled by the rotor is highly dependent on ε and H. Numerical simulations indicate that mass flow rate is maximized when ε ∼ 0, namely when the rotor is placed at a distance of 0.05 radii from the lower wall. The results also show that micro‐scale viscous pumps with curved housing provide higher mass flow rate per unit of shaft power consumed when compared with straight‐housed pumps. The results are presented in terms optimized dimensions of all three configurations (i.e., Hopt and εopt) and for values of the power‐law index varying between 0.5 (shear thinning fluids) and 1.5 (shear‐thickening fluids). Biotechnol. Bioeng. 2007;96: 37–47. © 2006 Wiley Periodicals, Inc.
Parvovirus B19 and immune disorders
Authors: Pugliese Agostino , Beltramo Tiziana , Torre Donato , Roccatello Dario
Published: August 2006

Parvovirus B19 (PVB19) is the causative agent of erythema infectiosum and sometimes the infection is correlated with severe haematological complications, or in pregnancy to fetalis hydrops. Moreover some authors suggest an infection involvement in some autoimmune diseases. To this purpose we evaluated seroprevalence for PVB19 in following the autoimmune or dysreactive pathologies: systemic lupus erythematosus (SLE), cryoglobulinemia, idiopathic systemic—ANCA associated vasculitis, rheumatoid arthritis (RA). In the case of LES, 31/42 patients were positive for PVB19 versus 21/42 of blood donors, as controls subjects (73.8% vs. 50%; significant difference for p < 0.05), moreover a significant difference for p < 0.001 was detected comparing mean titre values of IgGs against PVB19 of two groups (UI 1.94 ± 0.90 vs. 1.24 ± 0.80). In contrast no significant differences were found in the case of percent seropositivity of cryoglobulinemic subjects (37/57 = 64.9%, the majority of whom were HCV+) in comparison with the control group (50%). However mean units index (UI) was 1.63 ± 0.81; p = 0.019 versus the control group. Similar result, with regard to the percentage of seropositivity, was found for vasculitis (9/17 = 52.9%). The data reported here can confirm a possible correlation between PVB19 prior infection and LES and also suggest possible implications in the case of cryoglobulinemia. In fact, most of our patients were affected by a nephropathic or systemic form of HCV+ cryoglobulinemia and the presence of other infective cofactors could be suggestive in the evolution of this clinical situation. Copyright © 2006 John Wiley & Sons, Ltd.