bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of the cdk5/p25 fragment formation may explain the antiapoptotic effects of melatonin in an experimental model of Parkinson's disease
Authors: Alvira Daniel , Tajes Marta , Verdaguer Ester , Acuña‐Castroviejo Dario , Folch Jaume , Camins Antoni , Pallas Mercè
Published: January 2006

Abstract:  In this study, the effects of melatonin on MPP+‐treated cerebellar granule neurons (CGNs) in culture were investigated. Results showed that MPP+ treatment significantly decreased cell viability and increased the apoptotic cell population at 24 and 48 hr. Calpain and caspase‐3 activation was also determined, with results showing a strong increase in calpain (74%) and caspase 3 activity (70%), as measured by α‐spectrin cleavage and fluorometric and colorimetric analysis, respectively. There are several studies suggesting that the activation of the cdk5/p35 pathway at its cleavage to cdk5/p25 may play a role in neuronal cell death in neurodegenerative diseases. Moreover, these studies indicate that this cleavage is mediated by calpains, and that MPP+ prompted an increase in cdk5 expression, as well as the cleavage of p35–p25, in a time‐dependent manner. 1 mm Melatonin not only reduced the neurotoxic effects of MPP+ on cell viability, but also prevented apoptosis mediated by this Parkinsonian toxin in CGNs. 1 mm Melatonin reduced cdk5 expression, as well as the cleavage of p35–p25. These data indicate that melatonin possesses some neuro‐protective properties against MPP+‐induced apoptosis. Moreover, these data suggest that the calpain/cdk5 signaling cascade has a potential role in the MPP+‐mediated apoptotic process in CGNs.
Increase of MMP‐13 expression in multi‐stage oral carcinogenesis and epigallocatechin‐3‐gallate suppress MMP‐13 expression
Authors: Chiang W‐C , Wong Y‐K , Lin S‐C , Chang K‐W , Liu C‐J
Published: January 2006

Background:  Matrix metalloproteinases (MMPs) play pivotal roles in tumor progression. MMP‐13 (collagenase‐3) digests collagen and other extracellular components.

Materials and Methods:  Reverse transcriptase‐polymerase chain reaction (RT‐PCR), immunohistochemistry and zymograph were used to study the roles of MMP‐13 during the neoplastic process of oral squamous cell carcinoma (OSCC).

Results:  Increase of MMP‐13 mRNA and protein expression in OSCC cell lines relative to cultivated normal oral keratinocytes was found. MMP‐13 mRNA expression in OSCC was significantly higher than in non‐cancerous match tissue (NCMT) in 36 tissue pairs. Esophageal squamous cell carcinoma also exhibited high MMP‐13 mRNA expression. The percentage of OSCC exhibiting strong MMP‐13 immunoreactivity was significantly higher than pre‐invasive lesion and NCMT. Treatment with >5 μm epigallocatechin‐3‐gallate (EGCG) to OEC‐M1 cells suppressed the expression and activity of MMP‐13.

Conclusion:  MMP‐13 could be a potential tumor marker for OSCC. The effects of EGCG in tumor inhibition may act partially through the modulation of MMP‐13.
Association of asymptomatic oral candidal carriage, oral candidiasis and CD4+ lymphocyte count in HIV‐positive patients in China
Authors: Liu X , Liu H , Guo Z , Luan W
Published: January 2006

Objectives:  To compare the prevalence of asymptomatic oral candidal carriage in healthy volunteers with human immunodeficiency virus (HIV)‐positive patients in China, as well as to investigate the relationship between CD4+ lymphocyte count and oral candidal colonization or oral candidiasis.

Methods:  Oral candidal carriage and oral candidiasis were investigated in 101 patients with HIV‐infection seen at Youan Hospital, Beijing, China. Two hundred and seventeen healthy volunteers were involved as a control. Culture from saliva was used to test for the presence of oral Candida. CD4+ lymphocyte count was measured by flow cytometry. All data were analyzed statistically by SAS.

Results:  Asymptomatic oral candidal carriage rate (28.6%) in HIV‐positive group was similar to that in the healthy group (18.0%; P = 0.07). No significant difference in CD4+ lymphocyte count was found between oral Candida carriers and non‐carriers among HIV‐positive subjects (P = 0.89). However, the frequency of oral candidiasis increased with the decrease in CD4+ lymphocyte count (P < 0.0001), and pseudomembranous candidiasis was predominant in HIV‐positive patients with CD4+ <200 cells μl−1 (66.7%).

Conclusions:  In HIV‐positive subjects, asymptomatic oral candidal colonization is not related to CD4+ lymphocyte count of blood, and the carriage rate is similar to that in the healthy population. Oral candidiasis is more likely to be observed in HIV‐positive patients who have a low CD4+ lymphocyte count.
Efficacy of chlorhexidine–thymol varnish (Cervitec®) against plaque accumulation and gingival inflammation in a geriatric population
Authors: Clavero Javier , Baca Pilar , Paloma González Mª , Valderrama Mariano J
Published: January 2006

Objectives:  To determine whether the 3‐monthly application of chlorhexidine (CHX)–thymol varnish is an effective method of controlling plaque and gingivitis in a group of institutionalised elderly as a complement to their usual oral hygiene practices.

Design:  A 6‐month double‐blind clinical trial.

Setting:  Two residential homes in Almería (Spain).

Participants:  Fifty‐six dentate subjects aged above 64 years who completed the 6‐month study.

Intervention:  The study subjects were randomly assigned to one of two groups (Cervitec® or placebo). Varnishes were applied twice in the first week of the study and were applied again a month later and every 3 months until the end of the study. The patients continued with their usual oral hygiene practices throughout the study.

Measurement:  Plaque index and gingival index scores were determined at baseline and after 1, 3 and 6 months.

Results:  Treatment with Cervitec® varnish had a statistically significant effect overtime on the gingival index score (p = 0.029), but not on the plaque index score (p = 0.651). The groups did not significantly differ in reductions in plaque or gingival index scores between baseline and 1, 3 or 6 months.

Conclusion:  According to these results, Cervitec®, a CHX–thymol varnish, does not appear to reduce plaque and gingivitis by a 3‐monthly application in the institutionalised elderly with poor oral hygiene. Wider studies are required to investigate different varnishing protocols in geriatric populations.
Colonisation on the tongue surface by respiratory pathogens in residents of a nursing home – a pilot study
Authors: Sumi Y. , Miura H. , Nagaya M. , Michiwaki Y. , Uematsu H.
Published: January 2006

Objective:  The morbidity and mortality of the dependent elderly that result from aspiration pneumonia have been recognised as a major geriatric health problem. The tongue has an extremely large surface area and due to its papillary structure can retain considerable quantities of food, and thus can support and harbour a large bacterial population. The purpose of this study was to gain more information on the microflora of the tongue surface and to assess the existence of oral infectious pathogens potentially causing respiratory disease in nursing home residents.

Subjects and methods:  The tongue bacterial flora of 69 nursing home residents were examined to identify microorganisms by the culture method.

Results:  Thirteen species of microorganisms were detected from the tongue in this study. In 41 of 69 subjects (59%), potential respiratory pathogens, had colonised the tongue surface.

Conclusion:  The results of the present study revealed that bacteria that commonly cause respiratory infection colonised the tongue of nursing home residents, suggesting that it may function as a reservoir of potential respiratory pathogens to facilitate colonisation on the oropharynx.
History, Politics and Education: The Trouble with The Troubled Crusade
Authors: Reagan Timothy
Published: January 2006

Review of Diane Ravitch, The Troubled Crusade: American Education, 1945–1980.
A New Method for Assessing the Statistical Significance in the Differential Functioning of Items and Tests (DFIT) Framework
Authors: Oshima T. C. , Raju Nambury S. , Nanda Alice O.
Published: January 2006

A new item parameter replication method is proposed for assessing the statistical significance of the noncompensatory differential item functioning (NCDIF) index associated with the differential functioning of items and tests framework. In this new method, a cutoff score for each item is determined by obtaining a (1 −α) percentile rank score from a frequency distribution of NCDIF values under the no‐DIF condition by generating a large number of item parameters based on the item parameter estimates and their variance‐covariance structures from a computer program such as BIILOG‐MG3. This cutoff for each item can be used as the basis for determining whether a given NCDIF index is significantly different from zero. This new method has definite advantages over the current method and yields cutoff values that are tailored to a particular data set and a particular item. A Monte Carlo assessment of this new method is presented and discussed.
THE EFFECT OF MUTTON, GOAT, BEEF AND RABBIT‐MEAT SPECIES AND STATE OF RIGOR ON SOME TECHNOLOGICAL PARAMETERS
Authors: KARAKAYA M. , SARICOBAN C. , YILMAZ M.T.
Published: January 2006

The research consists of two steps with the goal to investigate the relationship between meat species (mutton, goat, beef and rabbit) in prerigor and postrigor stages in respect to emulsification capacity (EC), water‐holding capacity (WHC) and cooking loss (CL) parameters and the effect of rigor state of species on these parameters. For this purpose, immediately after slaughter and deboning, meat parts were assigned to both pre‐ and postrigor analyses. Tissue was ground, and then mixed to obtain homogeneous meat batches. Prerigor analyses were conducted in less than 90 min following slaughtering and deboning processes. Postrigor analyses were conducted after remaining meat parts were held for 24 h at 2C. The results showed that mutton and goat meats have higher EC and WHC values in both the pre‐ and postrigor stages. The rigor state of meat species affected significantly (P < 0.05) the pH, EC and WHC values. The prerigor stage of mutton and goat meat had the most desirable characteristics for emulsion‐type meat products.
SIMILARITIES AND DIFFERENCES IN COMPOSITION AND SELECTED SENSORY ATTRIBUTES OF REINDEER, CARIBOU AND BEEF
Authors: RINCKER P.J. , BECHTEL P.J. , FINSTADT G. , VAN BUUREN R.G.C. , KILLEFER J. , MCKEITH F.K.
Published: January 2006

The longissimus from caribou (n = 6), reindeer (n = 6) and beef (n = 6) were evaluated to determine differences in composition, color and sensory properties. Caribou contained the least fat followed by reindeer, and then beef (P < 0.05). Both venison sources contained more heme pigment and had a higher glycolytic potential than beef (P < 0.05). A trained sensory panel found both sources of venison to be more tender than beef (P < 0.05); however, Warner–Bratzler shear force yielded no significant differences. The sensory panel scored both reindeer and caribou as having a more intense off‐flavor (livery) and less intense meat‐flavor than beef (P < 0.05). Venison was darker than beef as determined by Minolta L* values (P < 0.05). No differences (P > 0.05) were found in ultimate pH or juiciness (sensory panel) among any of the products. Results from this study indicate that reindeer and caribou are a low‐fat source of protein with desirable sensory characteristics.
Solute Changes During Aquifer Storage Recovery Testing in a Limestone/Clastic Aquifer
Authors: Mirecki June E. , Campbell Bruce G. , Conlon Kevin J. , Petkewich Matthew D.
Published: January 2006

Aquifer storage recovery (ASR) was tested in the Santee Limestone/Black Mingo Aquifer near Charleston, South Carolina, to assess the feasibility for subsurface storage of treated drinking water. Water quality data obtained during two representative ASR tests were interpreted to show three things: (1) recovery efficiency of ASR in this geological setting; (2) possible changes in physical characteristics of the aquifer during ASR testing; and (3) water quality changes and potability of recovered water during short (one‐ and six‐day) storage durations in the predominantly carbonate aquifer.

Recovery efficiency for both ASR tests reported here was 54%. Successive ASR tests increased aquifer permeability of the Santee Limestone/Black Mingo Aquifer. It is likely that aquifer permeability increased during short storage periods due to dissolution of carbonate minerals and amorphous silica in aquifer material by treated drinking water. Dissolution resulted in an estimated 0.3% increase in pore volume of the permeable zones. Ground water composition generally evolved from a sodium‐calcium bicarbonate water to a sodium chloride water during storage and recovery. After short duration, stored water can exceed the U.S. Environmental Protection Agency maximum contaminant level (MCL) for chloride (250 mg/L). However, sulfate, fluoride, and tri‐halomethane concentrations remained below MCLs during storage and recovery.
Assessment of Hydraulic Parameters of the Aquifers Around the Sea of Galilee
Authors: Bergelson Gregory , Nativ Ronit , Bein Amos
Published: January 2006

Lack of storativity and transmissivity data from pumping tests in the multilayered, karstified aquifer system discharging into the Sea of Galilee resulted in the use of other techniques for parameter estimation. Water level fluctuations were used to calculate specific‐storage values, which ranged from 1.6 × 10−6 to 6.8 × 10−7 m−1 and from 4 × 10−6 to 2.7 × 10−7 m−1 in the lower and upper aquifer, respectively. Depletion curves were used to calculate transmissivity, which ranged from 0.3 to 24 m2/d and from 1 to 89 m2/d in the lower and upper aquifer, respectively. Age indicators were used to calculate hydraulic conductivity values: those obtained using radiocarbon data (0.54 to 7.5 m/d and 0.4 to 4 m/d for the upper and lower aquifer, respectively) were one order of magnitude higher than those obtained by depletion curve interpretation (10−3 ‐ 0.45 m/d), reflecting either the prevailing lower porosity (0.01) typical of the aquifers, or the impact of regional‐ vs. local‐scale measurements. The higher values obtained using radiocarbon were still a sixth of that calculated from a single pumping test in the area (40 m/d). The pumping test, however, is suggested to provide values which are too high because of leakage from adjacent formations during the test. The alternative techniques for parameter estimation presented here are recommended when pumping test data are lacking (while discharge and water level data do exist), or when regional rather than point transmissivity values are required.
Using Stable Isotopes of Water and Strontium to Investigate the Hydrology of a Natural and a Constructed Wetland
Authors: Hunt Randall J. , Bullen Thomas D. , Krabbenhoft David P. , Kendall Carol
Published: January 2006

Wetlands cannot exist without water, but wetland hydrology is difficult to characterize. As a result, compensatory wetland mitigation often only assumes the proper hydrology has been created. In this study, water sources and mass transfer processes in a natural and constructed wetland complex were investigated using isotopes of water and strontium. Water isotope profiles in the saturated zone revealed that the natural wetland and one site in the constructed wetland were primarily fed by ground water; profiles in another constructed wetland site showed recent rain was the predominant source of water in the root zone. Water isotopes in the capillary fringe indicated that the residence time for rain is less in the natural wetland than in the constructed wetland, thus transpiration (an important water sink) was greater in the natural wetland. Strontium isotopes showed a systematic difference between the natural and constructed wetlands that we attribute to the presence or absence of peat. In the peat‐rich natural wetland, δ87Sr in the pore water increased along the flowline due to preferential weathering of minerals containing radiogenic Sr in response to elevated Fe concentrations in the water. In the constructed wetland, where peat thickness was thin and Fe concentrations in water were negligible, δ87Sr did not increase along the flowline. The source of the peat (on‐site or off‐site derived) applied in the constructed wetland controlled the δ87Sr at the top of the profile, but the effects were restricted by strong cation exchange in the underlying fluvial sediments. Based on the results of this study, neither constructed wetland site duplicated the water source and weathering environment of the adjoining natural wetland. Moreover, stable isotopes were shown to be effective tools for investigating wetlands and gaining insight not easily obtained using non‐isotopic techniques. These tools have potential widespread application to wetlands that have distinct isotopic endmember sources.
Suitability of Parametric Models to Describe the Hydraulic Properties of an Unsaturated Coarse Sand and Gravel
Authors: Mace Andy , Rudolph David L. , Kachanoski R. Gary
Published: January 2006

The performance of parametric models used to describe soil water retention (SWR) properties and predict unsaturated hydraulic conductivity (K) as a function of volumetric water content (θ) is examined using SWR and K(θ) data for coarse sand and gravel sediments. Six 70 cm long, 10 cm diameter cores of glacial outwash were instrumented at eight depths with porous cup ten‐siometers and time domain reflectometry probes to measure soil water pressure head (h) and θ, respectively, for seven unsaturated and one saturated steady‐state flow conditions. Forty‐two θ(h) and K(θ) relationships were measured from the infiltration tests on the cores. Of the four SWR models compared in the analysis, the van Genuchten (1980) equation with parameters m and n restricted according to the Mualem (m = 1 ‐ 1/n) criterion is best suited to describe the θ(h) relationships. The accuracy of two models that predict K(θ) using parameter values derived from the SWR models was also evaluated. The model developed by van Genuchten (1980) based on the theoretical expression of Mualem (1976) predicted K(θ) more accurately than the van Genuchten (1980) model based on the theory of Burdine (1953). A sensitivity analysis shows that more accurate predictions of K(θ) are achieved using SWR model parameters derived with residual water content (θr) specified according to independent measurements of θ at values of h where θ/h ∼ 0 rather than model‐fit θr values. The accuracy of the model K(θ) function improves markedly when at least one value of unsaturated K is used to scale the K(θ) function predicted using the saturated K. The results of this investigation indicate that the hydraulic properties of coarse‐grained sediments can be accurately described using the parametric models. In addition, data collection efforts should focus on measuring at least one value of unsaturated hydraulic conductivity and as complete a set of SWR data as possible, particularly in the dry range.
A Decision Support Model to Assess Vulnerability to Salt Water Intrusion in the Great Bend Prairie Aquifer of Kansas
Authors: Sophocleous Marios , Ma Tainshing
Published: January 2006

A relatively simple ground water decision support system (DSS) was developed to assist in identifying salt‐water vulnerable areas and in developing management policies to prevent salt‐water intrusion in central Kansas. The DSS is based on a combination of numerical modeling sensitivity analyses, multiple regression analyses, and classification procedures derived from our knowledge of the area. Six ground water salinity models are proposed to evaluate irrigation well permit applications. The choice of model depends on the availability of site‐specific data. The DSS takes advantage of GIS database management procedures, and is applied to an actual salt‐water intrusion problem site in south‐central Kansas. This approach can help local ground water management districts make better decisions on protecting ground water use in salt water vulnerable areas.
Preferential Flow and Transport of Nitrate and Bromide in Clay pan Soil
Authors: Kelly Brian P. , Pomes Michael L.
Published: January 2006

The in situ measurement of water flow and chemical transport through clay pan soils is crucial to understanding potential water contamination from agricultural sources. It is important due to the large areal extent of these soils in agricultural regions of the midwestern United States and because of preferential flow paths caused by desiccation cracks, worms burrowing, and root development. A study plot at the Missouri Management Systems Evaluation Area near Centralia, Missouri, was instrumented to determine the rate of preferential flow of water and transport of NO3−1 fertilizer in the unsaturated zone through a claypan soil using 15N‐NO3−1 and Br‐1 tracers. The areal distribution of preferential flow paths was between 2 and 20% in the topsoil. Gravity lysimeter flow caused by preferential flow through the claypan was as much as 150 times greater than the estimated average rate of vertical recharge. As much as 2.4% of the volume of the soil below the clay pan may be occupied by preferential flow paths.

The 15N‐NO3−1 concentrations in ground water indicate that substantial quantities of fertilizer‐derived NO3−1 were transported to ground water through the claypan during the first recharge event following fertilizer application even though that event occurred six months after application. Hydraulic conductivity, measured at three scales, ranged from 6.2 × 10−8 to 7.5 × 10−3 cm/s. The observed increase of calculated hydraulic conductivity with each increase in scale was attributed to the inclusion of more and larger preferential flow paths within the volume over which the measurement was made, indicating hydraulic conductivity measured at one scale may not describe flow and transport at another scale.
Field Evaluation of Interfacial and Partitioning Tracers for Characterization of Effective NAPL‐Water Contact Areas
Authors: Annable M.D. , Jawitz J.W. , Rao P.S.C. , Dai D.P. , Kim H. , Wood A.L.
Published: January 2006

The use of surface‐active tracers for measuring the interfacial area between no aqueous phase liquids (NAPLs) and water was evaluated in a hydraulically isolated test cell installed in a surficial aquifer located at Hill Air Force Base (AFB), Utah. Interfacial tracers were developed at the University of Florida for quantifying immiscible fluid‐fluid interfaces (air‐water or NAPL‐water) in porous media. Sodium dodecyl benzene sulfonate (SDBS) was used as the interfacial tracer to measure the effective NAPL‐water interfacial area (aNw), while 2,2‐dimethyl‐3‐pentanol (DMP) was used as the partitioning tracer to estimate the NAPL saturation (SN). The observed retardation of SDBS and DMP when compared to a nonreactive tracer (bromide or methanol) at eight multilevel sampling locations and one extraction well, was used to quantify the aNw and SN values averaged over the interval between the injection wells and each monitoring point. The NAPL morphology index, defined here as HN= aNw/φSN (φ= porosity), varied significantly within the test cell. In locations where the magnitude of HN was large, the NAPL was assumed to be more or less uniformly spread, providing good contact with the mobile fluid. In contrast, regions with low HN values were assumed to have NAPL that was more heterogeneously distributed as isolated patches providing poor contact with the mobile fluid. The index HN, provided by the combined use of interfacial and partitioning tracers, has important implications for NAPL source region remediation employing in situ flushing technologies.
Effects of Sea Water Canals on Fresh Water Resources: An Example from Big Pine Key, Florida
Authors: Langevin C.D. , Stewart M.T. , Beaudoin C.M.
Published: January 2006

Management of the limited fresh water resources on small oceanic islands has become critical with increasing population and development in coastal areas. Canals, dredged for waterfront property and boat access, penetrate water‐bearing material and accelerate the natural discharge from fresh water lenses. Big Pine Key, located in the southern portion of the Florida Keys, is a heterogeneous, two‐layer island with several canal networks. The island is approximately 3 km wide and 10 km long. The upper hydros‐tratigraphic unit (Miami Oolite Limestone) has a hydraulic conductivity of 100 meters per day (m/day). The lower unit (Key Largo Limestone) has a hydraulic conductivity of 1200 m/day.

To quantify the effects of canals on the fresh water lens of Big Pine Key, a numerical model was developed using the Dupuit and Ghyben‐Herzberg assumptions. The thickness of the fresh water lens is sensitive to the location of the boundary between the upper and lower hydros‐tratigraphic layers. A simulation of present‐day Big Pine Key, including canals, compared with predevel‐opment conditions shows that the total volume of the lens has decreased by 20% in response to the dredging of canals. As dredging of canals will certainly continue in the future, the numerical model was also used to investigate the types of canals that are most detrimental to a fresh water lens. For an island 3 km wide and 10 km long, a canal that penetrates 2 km lengthwise into the island reduces the volume of the fresh water lens by 6.5%. For the same island dimensions, a canal that penetrates 2 km through the mid‐section of the island reduces the volume of the fresh water lens by 7.1 %. Several short canals, with a combined total length of 2 km decrease the volume of the fresh water lens by 4.0 %. The deeper the penetration of the canal into the lens, the greater the influence of the canal. Therefore, several short canals are preferred over one long canal because shorter canals have less of an effect on the total volume of the fresh water lens. Canals also focus ground water discharge. The three configurations of 2000 m long canals each discharge 13 to 15% of the total recharge to the island.
Semi analytical Evaluation of Three‐Dimensional Velocity Near a Partially Penetrating Well in an Unconfined Aquifer
Authors: Zlotnik Vitaly , Chen Xunhong , Sun Bei
Published: January 2006

This paper presents an effective semi analytical method for computation of ground water velocities near a partially penetrating well in an unconfined aquifer. The Neuman solution (1974) is presented as the sum of the Hantush solution (1964) and a correction term for water table conditions. Hydraulic gradients are directly evaluated from the Hantush solution, whereas the gradients for the Neuman correction are calculated using a numerical inversion of the Laplace transform. The method presented here is verified by comparing it with the results of a finite‐difference approximation of hydraulic gradients. Calculations of velocities near a pumping well in an unconfined aquifer indicate that, after an initial increase, the vertical velocity decreases before reaching steady state. The method provides a useful tool for the study of well hydraulics and contaminant transport to a pumping well in an unconfined aquifer.
A Controlled Experiment in Ground Water Flow Model Calibration
Authors: Hill Mary C. , Cooley Richard L. , Pollock David W.
Published: January 2006

Nonlinear regression was introduced to ground water modeling in the 1970s, but has been used very little to calibrate numerical models of complicated ground water systems. Apparently, nonlinear regression is thought by many to be incapable of addressing such complex problems. With what we believe to be the most complicated synthetic test case used for such a study, this work investigates using nonlinear regression in ground water model calibration. Results of the study fall into two categories. First, the study demonstrates how systematic use of a well designed nonlinear regression method can indicate the importance of different types of data and can lead to successive improvement of models and their parameterizations. Our method differs from previous methods presented in the ground water literature in that (1) weighting is more closely related to expected data errors than is usually the case; (2) defined diagnostic statistics allow for more effective evaluation of the available data, the model, and their interaction; and (3) prior information is used more cautiously. Second, our results challenge some commonly held beliefs about model calibration. For the test case considered, we show that (1) field measured values of hydraulic conductivity are not as directly applicable to models as their use in some geostatistical methods imply; (2) a unique model does not necessarily need to be identified to obtain accurate predictions; and (3) in the absence of obvious model bias, model error was normally distributed. The complexity of the test case involved implies that the methods used and conclusions drawn are likely to be powerful in practice.
A Method to Infer In Situ Reaction Rates from Push‐Pull Experiments
Authors: Snodgrass Mark F. , Kitanidis Peter K.
Published: January 2006

A method to evaluate first‐order and zero‐order in situ reaction rates from a push‐pull test is presented. A single‐well push‐pull test starts with the rapid injection of a well‐mixed slug containing a known quantity of a conservative tracer and a reactive solute into the saturated zone. The slug is then periodically extracted and sampled from the same well. For zero‐ or first‐order reactions, in the absence of sorption and assuming negligible background concentrations, these measurements can be used to evaluate reaction rate coefficients directly. The method does not involve computer‐based solute transport models and requires no knowledge of regional ground water flow or hydraulic parameters. The method performs well when the dominate processes are advection, dispersion, and zero‐ or first‐order irreversible reactions. Regional flow velocities must be sufficiently low such that the slug stays within the area of the well during the sampling phase. In the case of zero‐order reactions, results using the method proposed here are compared with those obtained through the traditional method of calibrating a computer‐based transport model. The two methods give similar estimates of the reaction rate coefficient. The method is general enough to work with a broad range of push‐pull experiment designs and sampling techniques.
Modeling a Complex Multi‐Aquifer System: The Waterloo Moraine
Authors: Martin P.J. , Frind E.G.
Published: January 2006

The Regional Municipality of Waterloo in Ontario, Canada (population 250,000) depends on ground water for most of its water supply. The ground water is extracted from the Waterloo Moraine, an extensive and complex glacial aquifer system extending over a 400 km2 area. A methodology is being developed to inventory the ground water resource, to define its susceptibility to contamination, and to create the basis for optimal management and protection strategies. A key component of this methodology is a three‐dimensional conceptual hydrogeologic model based on the geologic characteristics of the multiple‐aquifer Moraine system. The steps in the development of the model include screening of the large database, interpretation and interpolation of the data to define the variable hydrostatigraphy and to generate consistent hydraulic conductivity functions, and model calibration. The numerical basis is a fully three‐dimensional finite element model that provides flexibility and adaptability in representing the natural boundaries, the highly irregular stratigraphy, and the numerous wellfields. The model has the capability to automatically find the location of the water table consistent with given recharge and pumping conditions, and to direct recharge from low‐permeability areas to higher‐permeability areas. Capture zones generated by the model are found to be highly sensitive with respect to the geologic structure, in particular the presence or absence of windows in the aquitard units. Professional judgment is found to be an essential component of the modeling process.
Cytokine Response and Survival of Mice Immunized with an Adenovirus Expressing
Bacillus anthracis
Protective Antigen Domain 4
Authors: McConnell Michael J. , Hanna Philip C. , Imperiale Michael J.
Published: January 2006

Adenovirus vectors are promising for use in vaccinating against potential agents of bioterrorism and emerging infections because of their proven safety in humans and their ability to elicit rapid immune responses. Here, we describe the construction and evaluation of an adenovirus vaccine expressing domain 4 of
Bacillus anthracis
protective antigen, Ad.D4. Ad.D4 elicited antibodies to protective antigen 14 days after a single intramuscular injection, which were further increased upon boosting. Furthermore, two doses of Ad.D4 4 weeks apart were sufficient to protect 67% of mice from toxin challenge. Additionally, we have characterized the release of inflammatory cytokines from vaccinated mice after lethal-toxin challenge. We demonstrate that interleukin 1β (IL-1β) levels in mice that survive lethal toxin challenge are similar to levels in nonsurvivors and that IL-6 levels are higher in survivors than in nonsurvivors. These findings suggest that lethal-toxin-mediated death may not be a direct result of inflammatory-cytokine release.
Correlation of Molecular Characteristics, Isotype, and In Vitro Functional Activity of Human Antipneumococcal Monoclonal Antibodies
Authors: Baxendale H. E. , Goldblatt D.
Published: January 2006

Structure-function correlations of pneumococcal antibodies are important in predicting how changes in the pneumococcus (Pnc)-specific B-cell repertoire will influence humoral immunity against invasive Pnc disease. Using a unique panel of human hybridomas derived from memory B cells after pneumococcal conjugate vaccination, we analyzed the structure-function relationship of nine monoclonal antibodies (MAbs) reactive to Pnc polysaccharides. The avidities of the antibodies correlated with the avidity of donor immune serum (R, 0.7;P< 0.025), and this relationship was particularly strong for immunoglobulin A clones (R, 1;P< 0.0005), suggesting that the MAbs may represent important clones contributing to serological memory. Common heavy-light chain combinations and amino acid replacement mutations were seen for clones with the same serospecificity from different individuals. The two highest-avidity MAbs used Vh3-48, and two MAbs with the same serospecificity, using the same V gene pairings (Vh3-7 and Vk2A17), had similar avidities, suggesting that canonical V gene use makes an important contribution to avidity. Although all clones had mutation levels consistent with their being derived from memory B cells, low levels of replacement mutation were associated with high avidities. This relationship was strongest for Vh genes (R, 0.8;P< 0.01). Opsonophagocytosis was demonstrated for all clones, and there was a trend toward clones using canonical genes with low levels of mutation having high opsonophagocytic activities (R, 0.5). These data suggest that the use of canonical genes in the Pnc antibody response is associated with highly functional antibodies and that most somatic mutations seen in these genes are not antigen selected.
Cre Reporter System To Monitor the Translocation of Type III Secreted Proteins into Host Cells
Authors: Briones Gabriel , Hofreuter Dirk , Galán Jorge E.
Published: January 2006

Central to the study of type III secretion systems is the availability of reporter systems to monitor bacterial protein translocation into host cells. We report here the development of a bacteriophage P1 Cre recombinase-based system to monitor the translocation of bacterial proteins into mammalian cells. Bacteriophage P1 Cre recombinase fused to the secretion and translocation signals of
Salmonella enterica
serovar Typhimurium of the type III secreted protein SopE was secreted in a type III secretion system-dependent fashion. More importantly, the SopE-Cre chimera was translocated into host cells via the type III secretion system and activated the expression of luciferase and green fluorescent protein reporters of Cre recombinase activity.
Virulence of
Staphylococcus aureus
Small Colony Variants in the
Caenorhabditis elegans
Infection Model
Authors: Sifri Costi D. , Baresch-Bernal Andrea , Calderwood Stephen B. , von Eiff Christof
Published: January 2006

Small colony variants (SCVs) of
Staphylococcus aureus
are slow-growing morphological variants that have been implicated in persistent, relapsing, and antibiotic-resistant infections. The altered phenotype of SCVs in most strains has been attributed to defects in electron transport due to mutations in hemin or menadione biosynthesis. The pathogenic capacity of SCVs compared to phenotypically normal strains is variable depending on the attribute examined, with some studies showing reduced virulence of SCVs and others demonstrating normal or heightened virulence. Recently, the nematode
Caenorhabditis elegans
has been successfully employed as an alternative host to investigate virulence mechanisms of a variety of bacterial pathogens, including
S. aureus
. In this study, we show that clinical SCVs as well as
hemB
- and
menD
-deficient mutants of
S. aureus
are greatly reduced in virulence in the
C. elegans
infection model.
TheHelicobacter pyloriUrease B Subunit Binds to CD74 on Gastric Epithelial Cells and Induces NF-κB Activation and Interleukin-8 Production
Authors: Beswick Ellen J. , Pinchuk Irina V. , Minch Kyle , Suarez Giovanni , Sierra Johanna C. , Yamaoka Yoshio , Reyes Victor E.
Published: January 2006

The pathogenesis associated withHelicobacter pyloriinfection is the result of both bacterial factors and the host response. We have previously shown thatH. pyloribinds to CD74 on gastric epithelial cells. In this study, we sought to identify the bacterial protein responsible for this interaction.H. pyloriurease from a pool of bacterial surface proteins was found to coprecipitate with CD74. To determine how urease binds to CD74, we used recombinant urease A and B subunits. Recombinant urease B was found to bind directly to CD74 in immunoprecipitation and flow cytometry studies. By utilizing both recombinant urease subunits and urease B knockout bacteria, the urease B-CD74 interaction was shown to induce NF-κB activation and interleukin-8 (IL-8) production. This response was decreased by blocking CD74 with monoclonal antibodies. Further confirmation of the interaction of urease B with CD74 was obtained using a fibroblast cell line transfected with CD74 that also responded with NF-κB activation and IL-8 production. The binding of theH. pyloriurease B subunit to CD74 expressed on gastric epithelial cells presents a novel insight into a previously unrecognizedH. pyloriinteraction that may contribute to the proinflammatory immune response seen during infection.
Unique Transcriptome Signature of
Mycobacterium tuberculosis
in Pulmonary Tuberculosis
Authors: Rachman Helmy , Strong Michael , Ulrichs Timo , Grode Leander , Schuchhardt Johannes , Mollenkopf Hans , Kosmiadi George A. , Eisenberg David , Kaufmann Stefan H. E.
Published: January 2006

Although tuberculosis remains a substantial global threat, the mechanisms that enable mycobacterial persistence and replication within the human host are ill defined. This study represents the first genome-wide expression analysis of
Mycobacterium tuberculosis
from clinical lung samples, which has enabled the identification of
M. tuberculosis
genes actively expressed during pulmonary tuberculosis. To obtain optimal information from our DNA array analyses, we analyzed the differentially expressed genes within the context of computationally inferred protein networks. Protein networks were constructed using functional linkages established by the Rosetta stone, phylogenetic profile, conserved gene neighbor, and operon computational methods. This combined approach revealed that during pulmonary tuberculosis,
M. tuberculosis
actively transcribes a number of genes involved in active fortification and evasion from host defense systems. These genes may provide targets for novel intervention strategies.
The Established Intimin Receptor Tir and the Putative Eucaryotic Intimin Receptors Nucleolin and β1 Integrin Localize at or near the Site of Enterohemorrhagic
Escherichia coli
O157:H7 Adherence to Enterocytes In Vivo
Authors: Sinclair James F. , Dean-Nystrom Evelyn A. , O'Brien Alison D.
Published: January 2006

For enterohemorrhagic
Escherichia coli
(EHEC) O157:H7 to adhere tightly to the intestinal epithelium and produce
a
ttach and
e
fface (A/E) lesions, the organism must express the adhesin intimin and insert the bacterially encoded
t
ranslocated
i
ntimin
r
eceptor Tir into the plasma membrane of the host enterocyte. Additionally, some reports based on tissue culture experiments indicate that intimin has affinity for the eucaryotic proteins nucleolin and β1 integrin. To address the potential biological relevance of these eucaryotic proteins in the infection process in vivo, we sought to compare the proximity of Tir, nucleolin, and β1 integrin to regions of EHEC O157:H7 attachment in intestinal sections from three different inoculated animals: piglets, neonatal calves, and mice. Piglets and neonatal calves were chosen because intimin-mediated adherence of EHEC O157:H7 and subsequent A/E lesion formation occur at high levels in these animals. Mice were selected because of their ease of manipulation but only after we first demonstrated that in competition with the normal mouse gut flora, an EHEC O157:H7 strain with a nonpolar deletion in the intimin gene was cleared faster than strains that produced wild-type or hybrid intimin. In all three animal species, we noted immunostained Tir beneath and stained nucleolin closely associated with adherent bacteria in intestinal sections. We also observed immunostained β1 integrin clustered at locations of bacterial adherence in porcine and bovine tissue. These findings indicate that nucleolin and β1 integrin are present on the luminal surface of intestinal epithelia and are potentially accessible as receptors for intimin during EHEC O157:H7 infection.
Glucosyltransferases of Viridans Group Streptococci Modulate Interleukin-6 and Adhesion Molecule Expression in Endothelial Cells and Augment Monocytic Cell Adherence
Authors: Yeh Chiou-Yueh , Chen Jen-Yang , Chia Jean-San
Published: January 2006

Recruitment of monocytes plays important roles during vegetation formation and endocardial inflammation in the pathogenesis of infective endocarditis (IE). Bacterial antigens or modulins can activate endothelial cells through the expression of cytokines or adhesion molecules and modulate the recruitment of leukocytes. We hypothesized that glucosyltransferases (GTFs), modulins of viridans group streptococci, may act directly to up-regulate the expression of adhesion molecules and also interleukin-6 (IL-6) to augment monocyte attachment to endothelial cells. Using primary cultured human umbilical vein endothelial cells (HUVECs) as an in vitro model, we demonstrated that GTFs (in the cell-bound or free form) could specifically modulate the expression of IL-6, and also adhesion molecules, in a dose- and time-dependent manner. Results of inhibition assays suggested that enhanced expression of adhesion molecules was dependent on the activation of nuclear factor κB (NF-κB) and extracellular signal-regulated kinase and that p38 mitogen-activated protein kinase pathways also contributed to the release of IL-6. Streptococcus-infected HUVECs or treatment with purified IL-6 plus soluble IL-6 receptor α enhanced the expression of ICAM-1 and the adherence of the monocytic cell line U937. These results suggest that streptococcal GTFs might play an important role in recruiting monocytic cells during inflammation in IE through induction of adhesion molecules and IL-6, a cytokine involved in transition from neutrophil to monocyte recruitment.
Naturally Elicited Antibodies to Glycosylphosphatidylinositols (GPIs) of
Plasmodium falciparum
Require Intact GPI Structures for Binding and Are Directed Primarily against the Conserved Glycan Moiety
Authors: Naik Ramachandra S. , Krishnegowda Gowdahalli , Ockenhouse Christian F. , Gowda D. Channe
Published: January 2006

Immunization with a synthetic glycan corresponding to
Plasmodium falciparum
glycosylphosphatidylinositols (GPIs) has been proposed as a vaccination strategy against malaria. We investigated the structural requirements for binding of naturally elicited anti-GPI antibodies to parasite GPIs. The data show that anti-GPI antibody binding requires intact GPI structures and that the antibodies are directed predominantly against GPIs with a conserved glycan structure with three mannoses and marginally against the terminal fourth mannose. The results provide valuable insight for exploiting GPIs for the development of malaria vaccines.
Immune Responses Induced in Cattle by Vaccination with a Recombinant Adenovirus Expressing Mycobacterial Antigen 85A and
Mycobacterium bovis
BCG
Authors: Vordermeier H. Martin , Huygen Kris , Singh Mahavir , Hewinson R. Glyn , Xing Zhou
Published: January 2006

Cattle were vaccinated with an adenovirus expressing the mycobacterial antigen 85A (rAd85A), with
Mycobacterium bovis
BCG followed by rAd85A heterologous boosting, or with rAd85A followed by BCG boosting. BCG/rAd85A resulted in the highest direct gamma interferon responses. Cultured enzyme-linked immunospot assay analysis demonstrated that memory responses were induced by all three protocols but were strongest after BCG/rAd85A and rAd85A/BCG vaccination.
Clearance of EntericSalmonella entericaSerovar Typhimurium in Chickens Is Independent of B-Cell Function
Authors: Beal Richard K. , Powers Claire , Davison T. Fred , Barrow Paul A. , Smith Adrian L.
Published: January 2006

Salmonella entericaserovar Typhimurium colonizes the gut of chickens and is cleared from the intestine within about 3 weeks. Infection induces high levels of specific antibody, but B cells do not play an essential role in clearance of primary infection or in the enhanced clearance after secondary challenge.
Toll-Like Receptor 4 Protects against LethalLeptospira interrogansSerovar Icterohaemorrhagiae Infection and Contributes to In Vivo Control of Leptospiral Burden
Authors: Viriyakosol Suganya , Matthias Michael A. , Swancutt Mark A. , Kirkland Theo N. , Vinetz Joseph M.
Published: January 2006

The roles of innate immune responses in protection from or pathogenesis of severe leptospirosis remain unclear. We examined the role of Toll-like receptors (TLRs) in mouse infection and macrophage responses toLeptospira. C3H/HeJ mice (TLR4 deficient) and C3H/HeJ-SCID mice, but not C3H/OuJ mice (TLR4 intact), died after intraperitoneal infection withLeptospira interrogansserovar Icterohaemorrhagiae. Death in both C3H/HeJ mouse strains was associated with jaundice and pulmonary hemorrhage, similar to the patient from whom the isolate was obtained. In chronic sublethal infection, TLR4-deficient mice harbored more leptospires in liver, lung, and kidney than control mice. Heat-killedLeptospirastimulated macrophages to secrete proinflammatory cytokines, tumor necrosis factor alpha, interleukin-6, and macrophage inflammatory protein 2 not inhibited by polymyxin B, suggesting that leptospiral lipopolysaccharide (LPS) did not drive these responses. Anti-TLR4 and anti-MD-2 but not anti-CD14 monoclonal antibodies inhibited cytokine production. Peritoneal macrophages from CD14−/−and TLR2−/−mice exhibited no defect in cytokine responses toLeptospiracompared to controls. Macrophages from C3H/HeJ, TLR4−/−, and MyD88−/−mice secreted far-lower levels of cytokines than wild-type macrophages in response toLeptospira. TLR4 plays a crucial role in protection from acute lethal infection and control of leptospiral burden during sublethal chronic infection. Cytokine responses in macrophages correlated with leptospiral clearance. These TLR4-dependent but CD14/TLR2-independent responses are likely mediated by a leptospiral ligand(s) other than LPS.