bluuebunny/crossref_metadata_2025 huggingface dataset:
Child Care Is not a Substantial Risk Factor for Gastrointestinal Infection Hospitalization
Authors: Kamper-Jørgensen Mads , Andersen Lise Geisler , Simonsen Jacob , Sørup Signe
Published: December 2008

OBJECTIVE. The objective was to study the effect of age at first enrollment into child care and other child care–related factors on the risk for hospitalization from gastrointestinal infection.

METHODS. This was a population-based prospective cohort study of 1110973 Danish children aged 0 to 5 years in the period 1989–2004. By means of Poisson regression, risk for gastrointestinal infection hospitalization was evaluated by incidence rate ratio and 95% confidence intervals.

RESULTS. Overall, children who were attending child care had an IRR of gastrointestinal infection hospitalization of 1.02 compared with children in home care. When compared within the group of children who attended child care, those who were enrolled after 18 months of age had a slightly increased risk compared with those who were enrolled before 1 year of age. The first 5 months of enrollment were associated with an IRR of 1.18 compared with later periods, and similar risks were observed in different types of child care facilities. The effect of child care was similar in most strata of the studied child, family, and demographic variables; however, children younger than 1 year who attended child care had an IRR of 1.44 compared with children of the same age in home care. Well established risk factors for gastrointestinal infection such as young age and male gender were reproduced; compared with 5-year-olds, children younger than 1 year had an IRR of 7.37 and boys had an IRR of 1.18 compared with girls.

CONCLUSIONS. The results of this study suggest that child care attendance is not a substantial risk factor for gastrointestinal infection hospitalization in most Danish children. Late enrollment and the first short period of enrollment were associated with a slightly increased risk for gastrointestinal infection hospitalization.
Visual Function at 35 and 40 Weeks' Postmenstrual Age in Low-Risk Preterm Infants
Authors: Ricci Daniela , Cesarini Laura , Romeo Domenico M.M. , Gallini Francesca , Serrao Francesca , Groppo Michela , De Carli Agnese , Cota Francesco , Lepore Domenico , Molle Fernando , Ratiglia Roberto , De Carolis Maria Pia , Mosca Fabio , Romagnoli Costantino , Guzzetta Francesco , Cowan Frances , Ramenghi Luca A. , Mercuri Eugenio
Published: December 2008

OBJECTIVES. The objectives of this study were to (1) assess visual function in low-risk preterm infants at 35 and 40 weeks' postmenstrual age, (2) compare preterm visual abilities at term-equivalent age with term-born infants, and (3) evaluate effects of preterm extrauterine life on early visual function.

METHODS. Visual function was assessed by using a validated test battery at 35 and 40 weeks' postmenstrual age in 109 low-risk preterm infants who were born at <31 weeks' gestation. The preterm findings were compared with data from term-born infants collected by using the same test protocol.

RESULTS. All preterm infants completed both assessments. The 35-week responses were generally less mature than those at 40 weeks. Preterm infants at both ages were significantly more mature than term-born infants for ocular movements and vertical and arc tracking and at 40 weeks for stripe discrimination. In contrast, tracking a colored stimulus, attention at distance, and stripe discrimination were more mature at term age (in both term-born and preterm infants) than at 35 weeks.

CONCLUSIONS. Our findings provide data for visual function at 35 and 40 weeks' postmenstrual age in low-risk preterm infants. The results suggest that early extrauterine experience may accelerate the maturation of aspects of visual function related to ocular stability and tracking but does not seem to affect other aspects that may be more cortically mediated.
Mechanisms of adrenal gland growth: signal integration by extracellular signal regulated kinases1/2
Authors: Hoeflich Andreas , Bielohuby Maximilian
Published: December 2008

The adrenal gland influences a multitude of processes during stress response, but also potently affects the immune system, glucose metabolism, electrolyte or water homeostasis, and cardiovascular functions. According to the present understanding, the adrenal cortex is tightly controlled by the hypothalamic–pituitary–adrenal axis. This axis involves hypothalamic CRH and pituitary ACTH which determine processes of adrenocortical growth and function. However, control of the adrenal gland comprises a plethora of additional endogenous or exogenous factors. Among those are diverse hormones, psychosocial parameters, physiological stress, secondary plant products, or even environmental pollutants. In the present review, we summarize the current view of endocrine growth control in the adrenal gland. We then discuss intracellular mechanisms of adrenal growth control and focus on extracellular signal regulated kinases 1/2 (ERK1/2), which have been demonstrated to be controlled by not only ACTH or angiotensin II, but also by a large number of additional effectors. On the basis of these multiple exogenous or endogenous factors which impact on the adrenal gland through ERK1/2 activity, we speculate on a mechanism by which ERK1/2 act as a central integrative growth regulatory elements in the adrenal gland.
Achieving urban resilience: understanding and tackling disasters from a local perspective
Authors: Wamsler C.
Published: December 2008

The damage caused by a dramatic worldwide increase in so-called natural disasters is staggering, with the poor in developing countries being most at risk. This paper analyses: (a) the key variables and their causal relations that underlie the complex system of risk and disaster occurrence in slums; (b) the impacts of disasters on slums; (c) the strategies used by local people to cope with risk and disasters; and (d) the reasons for weak coping. The views and knowledge of slum dwellers in El Salvador are the focus of this analysis. On this basis, five complementary ex ante risk-reduction measures have been identified and developed to match local needs, capacities and dimensions of risk—hazard reduction (or prevention), mitigation, preparedness, risk ‘financing’ and stand-by for recovery. The complementary measures provide a frame of reference that allows urban development actors to systematically search for and design potential risk reduction measures. It is concluded that keeping these measures compartmentalised and separate from each other during planning and implementation of urban development programmes helps ensure both sustainable poverty reduction and urban resilience.
Effects of perfluorooctane sulfonate on rat thyroid hormone biosynthesis and metabolism
Authors: Yu Wen-Guang , Liu Wei , Jin Yi-He
Published: December 2008

The potential toxicity of perfluorooctane sulfonate (PFOS), an environmentally persistent organic pollutant, is of great concern. The present study examines the ability of PFOS to disturb thyroid function and the possible mechanisms involved in PFOS-induced thyroid hormone alteration. Male Sprague-Dawley rats were exposed to 1.7, 5.0, and 15.0 mg/L of PFOS in drinking water for 91 consecutive days. Serum was collected for analysis of total and free thyroxine (T4), total triiodothyronine (T3), and thyrotrophin (TSH). Thyroid and liver were removed for the measurement of endpoints closely related to thyroid hormone biosynthesis and metabolism following PFOS exposure. Determined endpoints were the messenger RNA (mRNA) levels for two isoforms of uridine diphosphoglucuronosyl transferases (UGT1A6 and UGT1A1) and type 1 deiodinase (DIO1) in liver, sodium iodide symporter (NIS), TSH receptor (TSHR), and DIO1 in thyroid as well as the activity of thyroid peroxidase (TPO). Serum total T4 level decreased significantly at all applied dosages, whereas total T3 level increased markedly only at 1.7 mg/L of PFOS. No statistically significant toxic effects of PFOS on serum TSH were observed. Hepatic UGT1A1, but not UGT1A6, mRNA was up-regulated at 5.0 and 15.0 mg/L of PFOS. Treatment with PFOS lowered hepatic DIO1 mRNA at 15.0 mg/L but increased thyroidal DIO1 mRNA dose dependently. The activity of TPO, NIS, and TSHR mRNA in thyroid were unaffected by PFOS treatment. These results indicate that increased hepatic T4 glucuronidation via UGT1A1 and increased thyroidal conversion of T4 to T3 via DIO1 were responsible in part for PFOS-induced hypothyroxinemia in rats.
Relating biomarkers to whole-organism effects using species sensitivity distributions: A pilot study for marine species exposed to oil
Authors: Smit Mathijs G. D. , Bechmann Renee K. , Hendriks A. Jan , Skadsheim Arnfinn , Larsen Bodil K. , Baussant Thierry , Bamber Shaw , Sanni Steinar
Published: December 2008

Biomarkers are widely used to measure environmental impacts on marine species. For many biomarkers, it is not clear how the signal levels relate to effects on the whole organism. This paper shows how species sensitivity distributions (SSDs) can be applied to evaluate multiple biomarker responses in species assemblages. To our knowledge, the present study compared for the first time SSDs based on biomarker response levels for marine species to a SSD for whole-organism responses. The comparison indicates that for exposure to dispersed oil in the marine environment, the selected biomarkers were, on average, 35- to 50-fold more sensitive than the whole-organism effect. At the 5% hazardous concentration derived from the SSD for whole-organism effects, which is a conservative threshold level, the potentially affected fraction of species showing biomarker response corresponds to approximately 80%. Variation in species sensitivity, expressed either as biomarker or as whole-organism response levels, were similar. Although uncertainties exist, the link between biomarkers and risk assessment presented here provides a preliminary guideline for deciding when biomarker responses likely are hazardous and, therefore, require further investigation.
GENERATING VARIABLE AND RANDOM SCHEDULES OF REINFORCEMENT USING MICROSOFT EXCEL MACROS
Authors: Bancroft Stacie L. , Bourret Jason C.
Published: December 2008

Variable reinforcement schedules are used to arrange the availability of reinforcement following varying response ratios or intervals of time. Random reinforcement schedules are subtypes of variable reinforcement schedules that can be used to arrange the availability of reinforcement at a constant probability across number of responses or time. Generating schedule values for variable and random reinforcement schedules can be difficult. The present article describes the steps necessary to write macros in Microsoft Excel that will generate variable‐ratio, variable‐interval, variable‐time, random‐ratio, random‐interval, and random‐time reinforcement schedule values.
EVALUATING THE ROLE OF CONTINGENCY IN DIFFERENTIALLY REINFORCED TIC SUPPRESSION
Authors: Himle Michael B. , Woods Douglas W. , Bunaciu Liviu
Published: December 2008

The current study evaluated the effects of tokens delivered on differential reinforcement of zero‐rate behavior (DRO) schedules or noncontingently on tic suppression in 4 children with tics. Tic frequency was lower in 3 of 4 children when tokens were delivered contingent on the absence of tics than when tokens were delivered noncontingently.
CONDITIONED REINFORCEMENT VALUE AND RESISTANCE TO CHANGE
Authors: Shahan Timothy A. , Podlesnik Christopher A.
Published: December 2008

Three experiments examined the effects of conditioned reinforcement value and primary reinforcement rate on resistance to change using a multiple schedule of observing‐response procedures with pigeons. in the absence of observing responses in both components, unsignaled periods of variable‐interval (Vi) schedule food reinforcement alternated with extinction. observing responses in both components intermittently produced 15 s of a stimulus associated with the VI schedule (i.e., S+). in the first experiment, a lower‐valued conditioned reinforcer and a higher rate of primary reinforcement were arranged in one component by adding response‐independent food deliveries uncorrelated with S+. In the second experiment, one component arranged a lower valued conditioned reinforcer but a higher rate of primary reinforcement by increasing the probability of VI schedule periods relative to extinction periods. In the third experiment, the two observing‐response components provided similar rates of primary reinforcement but arranged different valued conditioned reinforcers. Across the three experiments, observing‐response rates were typically higher in the component associated with the higher valued conditioned reinforcer. Resistance to change was not affected by conditioned reinforcement value, but was an orderly function of the rate of primary reinforcement obtained in the two components. One interpretation of these results is thatS+ value does not affect response strength and that S+ deliveries increase response rates through a mechanism other than reinforcement. Alternatively, because resistance to change depends on the discriminative stimulus‐reinforcer relation, the failure of S+ value to impact resistance to change could have resulted from a lack of transfer of S+ value to the broader discriminative context.
REINFORCER CONTROL BY COMPARISON‐STIMULUS COLOR AND LOCATION IN A DELAYED MATCHING‐TO‐SAMPLE TASK
Authors: Alsop Brent , Jones B. Max
Published: December 2008

Six pigeons were trained in a delayed matching‐to‐sample task involving bright‐ and dim‐yellow samples on a central key, a five‐peck response requirement to either sample, a constant 1.5‐s delay, and the presentation of comparison stimuli composed of red on the left key and green on the right key or vice versa. Green‐key responses were occasionally reinforced following the dimmer‐yellow sample, and red‐key responses were occasionally reinforced following the brighter‐yellow sample. Reinforcer delivery was controlled such that the distribution of reinforcers across both comparison‐stimulus color and comparison‐stimulus location could be varied systematically and independently across conditions. Matching accuracy was high throughout. The ratio of left to right side‐key responses increased as the ratio of left to right reinforcers increased, the ratio of red to green responses increased as the ratio of red to green reinforcers increased, and there was no interaction between these variables. However, side‐key biases were more sensitive to the distribution of reinforcers across key location than were comparison‐color biases to the distribution of reinforcers across key color. An extension of Davison and Tustin's (1978) model of DMTS performance fit the data well, but the results were also consistent with an alternative theory of conditional discrimination performance (Jones, 2003) that calls for a conceptually distinct quantitative model.
INSTRUCTIONAL EFFECTS ON PERFORMANCE IN A MATCHING‐TO‐SAMPLE STUDY
Authors: Drake Chad E. , Wilson Kelly G.
Published: December 2008

Conducting studies using an undergraduate participant pool is fraught with difficulties. Among them are problems with adequately motivating subjects both to come to the study, and once there, to actively engage the experimental task. Thirty‐one college students participated in a matching‐to‐sample (MTS) study involving substantial training, testing, retraining, and retesting of conditional discriminations and equivalence relations among four 4‐member classes of nonsensical words. The study was conducted during the end of the semester, when performance often had been observed to be poorer than at other points in the semester. Eleven of the participants, in addition to standard instructions about the task, received additional instructions specifying molar consequences for high rates of “correct” responses throughout the procedure. This subset of participants displayed markedly improved performance as compared to those who did not receive the additional instructions. Results suggest that specification of molar contingencies improves participants' sensitivity to molecular contingencies within the study. Instructions that specify and increase the consequential functions of feedback provided during MTS trials may be one means of reducing unwanted variability in human MTS performance.
Administration of High Doses of Caffeine Increases Alveolar Bone Loss in Ligature‐Induced Periodontitis in Rats
Authors: Bezerra Joyce Pinho , da Silva Luiz Ricardo Ferreira , de Alvarenga Lemos Vanessa Adélia , Duarte Poliana Mendes , Bastos Marta Ferreira
Published: December 2008

Background: Although some studies have reported a negative influence of caffeine on bone metabolism, there is no information about its effect on the progression of periodontitis. The aim of this study was to evaluate the effect of high doses of caffeine on ligature‐induced periodontitis in rats.

Methods: Twenty‐two Wistar rats were assigned to one of the following groups: non‐caffeine group (n = 12) = animals without caffeine ingestion; caffeine group (n = 10) = animals ingesting 10 mg/100 g body weight/day of caffeine via drinking water for 56 days. Two weeks after the beginning of caffeine intake, one of the mandibular molar was randomly assigned to receive a ligature, whereas the contralateral molar was left unligated. Forty‐two days later, the animals were sacrificed, and the specimens were processed to obtain decalcified sections. The area of periodontal ligament and/or bone loss in the furcation region of the first molars was histometrically determined.

Results: Caffeine intake did not have a direct effect on the alveolar bone loss in unligated teeth. But on the ligated tooth, a greater area of bone loss was observed in the animals that ingested caffeine compared to those that did not (P <0.05).

Conclusion: The present study demonstrated that daily intake of high doses of caffeine may enhance ligature‐induced periodontitis progression.
High-Risk Behaviors Among Men Who Have Sex With Men in 6 US Cities: Baseline Data From the EXPLORE Study
Authors: Koblin Beryl A. , Chesney Margaret A. , Husnik Marla J. , Bozeman Sam , Celum Connie L. , Buchbinder Susan , Mayer Kenneth , McKirnan David , Judson Franklyn N. , Huang Yijian , Coates Thomas J. ,   the EXPLORE Study Team
Published: December 2008

Objectives. We describe the prevalence of risk behaviors at baseline among men who have sex with men (MSM) who were enrolled in a randomized behavioral intervention trial conducted in 6 US cities.

Methods. Data analyses involved MSM who were negative for HIV antibodies and who reported having engaged in anal sex with 1 or more partners in the previous year.

Results. Among 4295 men, 48.0% and 54.9%, respectively, reported unprotected receptive and insertive anal sex in the previous 6 months. Unprotected sex was significantly more likely with 1 primary partner or multiple partners than with 1 nonprimary partner. Drug and alcohol use were significantly associated with unprotected anal sex.

Conclusions. Our findings support the continued need for effective intervention strategies for MSM that address relationship status, serostatus of partners, and drug and alcohol use.
Predictors of Risky Sexual Behavior Among Young African American Men Who Have Sex With Men
Authors: Hart Trevor , Peterson John L. ,   The Community Intervention Trial for Youth Study Team
Published: December 2008

This study examined the prevalence and correlates of unprotected anal intercourse among 758 young African American men who have sex with men. A quarter of the sample reported unprotected anal intercourse in the past 3 months; nonsupportive peer norms and not carrying condoms predicted risky sexual behavior. Effective interventions are needed that promote the use of condoms by changing peer norms and encouraging carrying condoms.
Hydroclimatic analysis of an ice-scar tree-ring chronology of a high-boreal lake in Northern Québec, Canada
Authors: Lemay Mickaël , Bégin Yves
Published: December 2008

Ice-scars were investigated to reconstruct the ice-flood history of Corvette Lake in Northern Québec in an attempt to determine the hydrological threshold of shore ice and identify the accompanying climatic conditions. The ice-scar record started around 1850 and showed a rapid increase in frequency at the start of the 1930s, while trees damaged by the ice were already mature and established over several decades. The study supports the hypothesis that this shift could correspond to an increase in flood discharge. Hydrological analysis of every event that occurred since 1961, the year during which instrumental recording began, indicated that scar frequency and scar maximum height were strongly correlated with average recession discharge, average flood discharge, peak discharge and flood onset. Ice-scars provided a discontinuous record of discrete events triggered by hydrologic extremes that were used to document the instrumental record using logistic regression. Results from multiple regressions suggested that ice-scars correspond to years with highs in total precipitation from January to March and from May to June, in the sum of degree-days of frost in April, and in the sum of degree-days of heat from October to April. Although imperfect for reconstructing past events, this study exemplifies the potential use of ice-scars for extending the historical record of ice-floods with hydroclimatic significance.
Assessing the value of Cl− and δ18O data in modelling the hydrological behaviour of a small upland catchment in northeast Scotland
Authors: Dunn Sarah M. , Bacon Jeffrey R.
Published: December 2008

Model simulation of Cl− and δ18O in stream waters has been investigated as a means of improving interpretation of catchment-scale hydrological processes. The procedure has been evaluated for a small upland catchment which is one of the UK Environmental Change Network sites. Precipitation and stream samples have been analysed for hydrochemical determinands since the mid 1990s and, since November 2004, measurement of δ18O has also been undertaken. A conceptual hydrological model STREAM (STorage REsidence times And Mixing) was applied to the catchment to simulate the hydrology and responses of Cl− and δ18O. Results from model simulations confirmed that the catchment generally behaves as a well-mixed system. The feasibility of flow contributions from a deep groundwater source and infiltration excess runoff was examined, in addition to the apparently dominant shallow groundwater response. The ability to estimate mean residence times and draw strong conclusions about catchment processes was limited by the range of uncertainties in the experimental data and modelling. Integration of the tracer data in the model was found to be of value for probing model sensitivities and developing hypotheses that inform the design of further field experimentation. In this way, the modelling provides key feedback within a catchment learning framework.
Prediction of Tire Profile Wear by Steady-State FEM
Authors: Smith K. R. , Kennedy R. H. , Knisley S. B.
Published: December 2008

Much research is being done in the tire industry in order to reduce tire development time as well as cost. One such field of particular importance is that of tread wear, where testing time for indoor tests is measured in days, compared to weeks for outdoor tests. Development time could be further reduced if a “virtual wear test” could be performed using a finite element approach to predict friction energy. The purpose of this study is to investigate the link between indoor tread wear profile and steady-state finite element prediction of friction energy. Blank grooved tires of a common construction with three different tread compounds are run through indoor wear tests of different severities to study severity versus compound interaction. The drive files provide a mix of low-speed cornering maneuvers that simulate city driving as well as highway speed steady-state rolling with acceleration and braking events. One drive file places more emphasis on the city maneuvers while the other places emphasis on the highway driving. Using the steady-state finite element model, a composite friction energy is calculated from friction energy predictions at selected loading conditions taken from the drive file events. The composite friction energy profile is finally compared to laser measurements of the worn tire profile to examine the feasibility of a “virtual wear test.”
In vivo effects of intra-articular injection of gelatin hydrogen microspheres containing basic fibroblast growth factor on experimentally induced defects in third metacarpal bones of horses
Authors: Sasaki Naoki , Minami Takuto , Yamada Kazutaka , Yamada Haruo , Inoue Yoshinobu , Kobayashi Mitsutoshi , Tabata Yasuhiko
Published: December 2008

Objective—To evaluate the effect of intra-articular injection of gelatin hydrogel microspheres containing basic fibroblast growth factor (bFGF) on experimentally induced defects in third metacarpal bones (MC3s) of horses, in vivo.

Animals—6 healthy adult Thoroughbreds.

Procedures—Horses were anesthetized, and a hole (diameter, 4.5 mm) was drilled into the medial condyle of both MC3s of each horse. One milliliter (100 μg) of a solution of gelatin hydrogel microspheres (2 mg) containing bFGF was injected into the joint capsule of the right metacarpophalangeal joint of each horse (bFGF joint). One milliliter of saline (0.9% NaCl) solution was injected into the left metacarpophalangeal joint (control joint). Radiography was performed 1 day and 4, 8, 12, and 16 weeks after surgery to evaluate bone defect refilling. Sixteen weeks after surgery, multidetector-row computed tomography (MDRCT) was performed to determine the degree of refilling at the bone defect site.

Results—Radiography revealed healing of bone defects at 4 to 12 weeks after surgery in bFGF joints and at 8 to 16 weeks after surgery in control joints. In addition, MDRCT revealed a higher degree of healing in bFGF versus control joints. Mean ± SD MDRCT score for bFGF joints (411.7 ± 135.6 Hounsfield units) was significantly higher than that for control joints (240.8 ± 133.1 Hounsfield units).

Conclusions and Clinical Relevance—Treatment of horses with gelatin hydrogel microspheres that contained bFGF enhanced bone regeneration and healing of experimentally induced defects. This treatment strategy may be useful for treating horses with fractures.
Effects of simulated digests of Biota orientalis and a dietary nutraceutical on interleukin-1– induced inflammatory responses in cartilage explants
Authors: Pearson Wendy , Orth Michael W. , Karrow Niel A. , Lindinger Michael I.
Published: December 2008

Objective—To test the hypothesis that simulated digests of Biota orientalis (BO) and a dietary nutraceutical (DN; composed of mussel, shark cartilage, abalone, and BO seed lipid extract) inhibit prostaglandin E2 (PGE2), nitric oxide (NO), and glycosaminoglycan (GAG) production in interleukin (IL)-1–stimulated cartilage explants.

Sample Population—Cartilage tissue from 12 pigs.

Procedures—Articular cartilage explants were conditioned with a simulated digest of BO (BOsim) or DN (DNsim) at concentrations of 0, 0.06, or 0.18 mg/mL or indomethacin (INDOsim; 0 or 0.02 mg/mL) for 72 hours. Control explants received digest vehicle only. Explants were or were not stimulated with recombinant human-IL-1β (10 or 0 ng/mL) during the final 48 hours of culture. Concentrations of PGE2, GAG, and NO in media samples (mPGE2,mGAG, and mNO concentrations, respectively) were analyzed, and explant tissue was stained fluorochromatically to determine chondrocyte viability. Treatment effects during the final 48-hour culture period were analyzed.

Results—IL-1 increased mPGE2, mGAG, and mNO concentrations in control explants without adversely affecting cell viability. Treatment with INDOsim blocked PGE2 production and increased mNO concentration in IL-1–stimulated and unstimulated explants and increased mGAG concentration in unstimulated explants. Treatment with DNsim (0.06 and 0.18 mg/mL) reduced mPGE2 concentration in IL-1–stimulated and unstimulated explants, reduced mNO concentration in IL-1–stimulated explants, and increased mNO concentration in unstimulated explants. Treatment with 0.18 mg of DNsim/mL increased cell viability in the presence of IL-1. In IL-1–stimulated explants, BOsim (0.06 and 0.18 mg/mL) reduced mPGE2 concentration, but 0.18 mg of BOsim/mL increased cell viability.

Conclusions and Clinical Relevance—Effects of IL-1 on cartilage explants in vitro were modulated by DNsim and BOsim.
Effect of coinfection with genogroup 1 porcine torque teno virus on porcine circovirus type 2–associated postweaning multisystemic wasting syndrome in gnotobiotic pigs
Authors: Ellis John A. , Allan Gordon , Krakowka Steven
Published: December 2008

Objective—To determine whether genogroup 1 porcine torque teno virus (g1-TTV) can potentiate clinical disease associated with porcine circovirus type 2 (PCV2).

Sample population—33 gnotobiotic baby pigs.

Procedures—Pigs were allocated into 7 groups: group A, 5 uninoculated control pigs from 3 litters; group B, 4 pigs oronasally inoculated with PCV2 alone; group C, 4 pigs inoculated IP with first-passage g1-TTV alone; group D, 4 pigs inoculated IP with fourth-passage g1-TTV alone; group E, 6 pigs inoculated IP with first-passage g1-TTV and then oronasally inoculated with PCV2 7 days later; group F, 6 pigs inoculated IP with fourth-passage g1-TTV and then inoculated oronasally with PCV2 7 days later; and group G, 4 pigs inoculated oro-nasally with PCV2 and then inoculated IP with fourth-passage g1-TTV 7 days later.

Results—6 of 12 pigs inoculated with g1-TTV prior to PCV2 developed acute onset of postweaning multisystemic wasting syndrome (PMWS). None of the pigs inoculated with g1-TTV alone or PCV2 alone or that were challenge exposed to g1-TTV after establishment of infection with PCV2 developed clinical illness. Uninoculated control pigs remained healthy.

Conclusions and Clinical Relevance—These data implicated g1-TTV as another viral infection that facilitates PCV2-induced PMWS. This raises the possibility that torque teno viruses in swine may contribute to disease expression currently associated with only a single infectious agent.
Evaluation of the effects of porcine genogroup 1 torque teno virus in gnotobiotic swine
Authors: Krakowka Steven , Ellis John A.
Published: December 2008

Objective—To determine whether porcine genogroup 1 torque teno virus (g1-TTV) can infect and cause disease in gnotobiotic swine.

Sample Population—20 conventional baby pigs and 46 gnotobiotic baby pigs.

Procedures—Porcine g1-TTV was transmitted from conventional swine to gnotobiotic pigs via pooled leukocyte-rich plasmas (n = 18) that had positive results for g1-TTV DNA. Bone marrow–liver homogenates that had positive results for torque teno virus (TTV) were used in 4 serial passages in gnotobiotic pigs (2 pigs/passage). A pathogenesis experiment was conducted with in vivo passages of g1-TTV in various groups of gnotobiotic pigs.

Results—All g1-TTV inoculated pigs had no clinical signs but developed interstitial pneumonia, transient thymic atrophy, membranous glomerulonephropathy, and modest lymphocytic to histiocytic infiltrates in the liver after inoculation with the TTV-containing tissue homogenate; these changes were not detected in uninoculated control pigs or pigs injected with tissue homogenate devoid of TTV DNAs. In situ hybridization was used to identify g1-TTV DNAs in bone marrow mononuclear cells.

Conclusions and Clinical Relevance—Analysis of these data revealed that porcine g1-TTV was readily transmitted to TTV-naïve swine and that infection was associated with characteristic pathologic changes in gnotobiotic pigs inoculated with g1-TTV. Thus, g1-TTV could be an unrecognized pathogenic viral infectious agent of swine. This indicated a directly associated induction of lesions attributable to TTV infection in swine for a virus of the genus Anellovirus.
Comparison of the pharmacokinetic properties of bisoprolol and carvedilol in healthy dogs
Authors: Beddies Gerald , Fox Philip R. , Papich Mark D. , Kanikanti Venkata-Rangaro , Krebber Ralph , Keene Bruce W.
Published: December 2008

Objective—To compare the pharmacokinetic properties and bioavailability following oral and IV administration of bisoprolol, a second-generation β1-adrenoceptor–selective blocking agent, with those of carvedilol, a third-generation β1/β2 and α1-adrenoceptor blocking agent, in dogs.

Animals—12 healthy adult Beagles.

Procedures—A prospective, parallel group study was performed. The dogs were allocated to 1 of 2 groups (6 dogs/group) and were administered orally a 1 mg/kg dose of either bisoprolol or carvedilol. Following a 1-week washout period, each cohort received a 1 mg/kg dose of the same drug IV. Blood samples were collected before and after drug administration, and serum concentrations, pharmacokinetic variables, and bioavailability for each agent were assessed.

Results—After oral administration of bisoprolol, the geometric mean value of the area under the concentration-time curve extrapolated to infinity (AUCinf) was 2,195 μg/L (coefficient of variation [CV], 15%). After IV administration of bisoprolol, the dose-normalized geometric mean AUCinf was 2,402 μg/L (CV, 19%). Oral bioavailability of bisoprolol was 91.4%. After oral administration of carvedilol, the geometric mean AUCinf was 70 μg/L (CV, 81%). After IV administration of carvedilol, the geometric mean AUCinf was 491 μg/L (CV, 23%). Oral bioavailability of carvedilol was 14.3%. Total body clearance was low (0.42 L/h/kg) for bisoprolol and high (2.0 L/h/kg) for carvedilol.

Conclusions and Clinical Relevance—After oral administration, carvedilol underwent extensive first-pass metabolism and had limited bioavailability; bisoprolol had less first-pass effect and higher bioavailability. Collectively, these differences suggested that, in dogs, bisoprolol has less interindividual pharmacokinetic variability, compared with carvedilol.
Economic evaluation of an oral rabies vaccination program for control of a domestic dog–coyote rabies epizootic: 1995–2006
Authors: Shwiff Stephanie A. , Kirkpatrick Katy N. , Sterner Ray T.
Published: December 2008

Objective—To conduct a benefit-cost analysis of the results of the domestic dog and coyote (DDC) oral rabies vaccine (ORV) program in Texas from 1995 through 2006 by use of fiscal records and relevant public health data.

Design—Retrospective benefit-cost analysis.

Procedures—Pertinent economic data were collected in 20 counties of south Texas affected by a DDC-variant rabies epizootic. The costs and benefits afforded by a DDC ORV program were then calculated. Costs were the total expenditures of the ORV program. Benefits were the savings associated with the number of potentially prevented human postexposure prophylaxis (PEP) treatments and animal rabies tests for the DDC-variant rabies virus in the epizootic area and an area of potential disease expansion.

Results—Total estimated benefits of the program approximately ranged from $89 million to $346 million, with total program costs of $26,358,221 for the study period. The estimated savings (ie, damages avoided) from extrapolated numbers of PEP treatments and animal rabies tests yielded benefit-cost ratios that ranged from 3.38 to 13.12 for various frequen-cies of PEP and animal testing.

Conclusions and Clinical Relevance—In Texas, the use of ORV stopped the northward spread and led to the progressive elimination of the DDC variant of rabies in coyotes (Canis latrans). The decision to implement an ORV program was cost-efficient, although many unknowns were involved in the original decision, and key economic variables were identified for consideration in future planning of ORV programs.
Assessment of arteriovenous malformations with 3-Tesla time-resolved, contrast-enhanced, three-dimensional magnetic resonance angiography
Authors: Kunishima Kanako , Mori Harushi , Itoh Daisuke , Aoki Shigeki , Kabasawa Hiroyuki , Koga Tomoyuki , Maruyama Keisuke , Masumoto Tomohiko , Abe Osamu , Ohtomo Kuni
Published: December 2008

Object

Although conventional catheter angiography is commonly used in the evaluation of intracranial arteriovenous malformations (AVMs), less invasive tools are more suitable for screening or follow-up. Older MR angiography techniques cannot provide high enough temporal and spatial resolution for assessing AVMs. Threetesla time-resolved imaging of contrast kinetics (TRICKS)—a time-resolved, contrast-enhanced 3D MR angiography technique—achieves subsecond time resolution without sacrificing spatial resolution. The purpose of this study was to assess the accuracy of TRICKS at 3 T in the evaluation of AVMs.

Methods

Between November 2006 and November 2007, 31 patients who were known to have AVMs underwent evaluation in a 3-T unit with the TRICKS technique. The TRICKS images were then evaluated independently by 2 radiologists for nidus detection, early venous filling detection, and Spetzler-Martin classification, and these results were compared with the results of catheter angiography.

Results

Time-resolved imaging of contrast kinetics achieved 96% sensitivity and 100% specificity both in nidus detection and early venous filling detection. The Spetzler-Martin grades also showed excellent correlation with catheter angiography findings (κ= 0.89).

Conclusions

Although this is a preliminary study, the authors' results indicate that time-resolved contrast-enhanced 3D MR angiography at 3 T is a good tool to assess AVMs, and has the potential to replace catheter angiography in screening or follow-up examinations of patients with AVMs.
Treatment of idiopathic head drop (camptocephalia) by deep brain stimulation of the globus pallidus internus
Authors: Sakas Damianos E. , Panourias Ioannis G. , Boviatsis Efstathios J. , Themistocleous Marios S. , Stavrinou Lambis C. , Stathis Pantelis , Gatzonis Stylianos D.
Published: December 2008

Deep brain stimulation of the globus pallidus internus has been shown to be beneficial in a small number of patients suffering from axial dystonias. However, it has not yet been reported as an effective treatment for the alleviation of idiopathic head drop. The authors describe a 49-year-old woman with idiopathic cervical dystonia (camptocephalia) who was unable to raise her head > 30° when standing or sitting; her symptoms would abate when lying down. This disabling neurological condition was treated successfully with bilateral chronic electrical stimulation of the globus pallidus internus.
Determination of Economic Injury Levels of Maruca vitrata in Mungbean
Authors: Zahid MA , Islam MM , Begum MR
Published: December 2008

Maruca vitrata is considered to be one of the major pests of mungbean. The damage potential and economic threshold levels of Maruca vitrata larvae on mungbean were worked out at ARS, BARI, Burirhat, Rangpur during rabi 2005-2006 and 2006-2007. On an average single larva per m row reduced the yield to the extent of 154 kg/ha and 106 kg/ha in 2005-2006 and 2006-2007 cropping seasons, respectively. The ratio of the value of yield saved to the cost of insecticide application at one larva per m row in 2005-2006 was 1.45 and same in 2006-2007 was 1.34. EIL for Maruca vitrata were determined as 1.0 and 1.16 larvae per m row in 2005-2006 & 2006-2007respectively. ET value was determined from EILs and those were found to be at 0.75 and 0.87 larvae per m row in 2005-2006 & 2006-2007 respectively. On the basis of means of two years the EIL and ETL values of Maruca vitrata were 1.08 & 0.81 larvae per m row, respectively. Key words: ETL, EIL, Maruca vitrata, Mungbean. doi:10.3329/jard.v6i1.1662 J Agric Rural Dev 6(1&2), 91-97, June 2008
Gene-Environment Interactions in the Development of Complex Disease Phenotypes
Authors: Ramos Rosemarie G. , Olden Kenneth
Published: December 2008

The lack of knowledge about the earliest events in disease development is due to the multi-factorial nature of disease risk. This information gap is the consequence of the lack of appreciation for the fact that most diseases arise from the complex interactions between genes and the environment as a function of the age or stage of development of the individual. Whether an environmental exposure causes illness or not is dependent on the efficiency of the so-called “environmental response machinery” (i.e., the complex of metabolic pathways that can modulate response to environmental perturbations) that one has inherited. Thus, elucidating the causes of most chronic diseases will require an understanding of both the genetic and environmental contribution to their etiology. Unfortunately, the exploration of the relationship between genes and the environment has been hampered in the past by the limited knowledge of the human genome, and by the inclination of scientists to study disease development using experimental models that consider exposure to a single environmental agent. Rarely in the past were interactions between multiple genes or between genes and environmental agents considered in studies of human disease etiology. The most critical issue is how to relate exposure-disease association studies to pathways and mechanisms. To understand how genes and environmental factors interact to perturb biological pathways to cause injury or disease, scientists will need tools with the capacity to monitor the global expression of thousands of genes, proteins and metabolites simultaneously. The generation of such data in multiple species can be used to identify conserved and functionally significant genes and pathways involved in geneenvironment interactions. Ultimately, it is this knowledge that will be used to guide agencies such as the U.S. Department of Health and Human Services in decisions regarding biomedical research funding and policy.
Vehicle-Dependent Disposition Kinetics of Fluoranthene in Fisher-344 Rats
Authors: Harris Deacqunita L. , Hood Darryl B. , Ramesh Aramandla
Published: December 2008

The objective of this study was to evaluate how the vehicles of choice affect the pharmacokinetics of orally administered Fluoranthene [FLA] in rats. Fluoranthene is a member of the family of polycyclic aromatic hydrocarbon chemicals. Fluoranthene exposure to humans may occur as a result of cigarette smoking, consumption of contaminated food and water, heating woods in stoves and boilers, industrial sources such as coal gasification, carbon and graphite electrode manufacturing. Adult male Fisher-344 rats were given single oral doses of 25 and 50 μg/kg FLA in tricaprylin, peanut oil, cod liver oil, tween 80/isotonic saline (1:5) and 2% Alkamuls-EL620 through gavage. After administration, the rats were housed individually in metabolic cages and sacrificed at 2, 4, 6, 8, 10 and 12 hours post FLA exposure. Blood, lung, liver, small intestine, adipose tissue samples, urine, and feces were collected at each time point. Samples were subjected to a liquid-liquid extraction using methanol, chloroform, and water. The extracts were analyzed by a reverse-phase HPLC, equipped with a fluorescence detector. The results revealed a dose-dependent increase in FLA concentrations in plasma and tissues for all the vehicles used. Plasma and tissue FLA concentrations were greater for peanut oil; cod liver oil, and tricaprylin vehicles compared to Alkamuls (p < 0.05), and tween 80/isotonic saline (1:5). Most of the FLA administered through peanut oil, cod liver oil and tricaprylin was cleared from the body by 8 hours (90%) and 12 hours (80%) post administration for the 25 μg/kg and 50 μg/kg dose groups, respectively. With both doses employed, the metabolism of FLA was highest when cod liver oil was used as a vehicle and lowest in vehicles containing detergent/water [cod liver oil > peanut oil > tricaprylin > alkamuls > tween 80/isotonic saline (1:5)]. These findings suggest that uptake and elimination of FLA is accelerated when administered through oil-based vehicles. The low uptake of FLA from alkamuls and tween 80/isotonic saline may have been a result of the poor solubility of the chemical. In summary, our findings reiterate that absorption characteristics of FLA were governed by the dose as well as the dosing vehicle. The vehicle-dependent bioavailability of FLA suggests a need for the judicious selection of vehicles in evaluating oral toxicity studies for risk assessment purposes.
Geospatial Information Systems Analysis of Regional Environmental Change along the Savannah River Basin of Georgia
Authors: Twumasi Yaw A. , Merem Edmund C.
Published: December 2008

This paper uses remote sensing and geographic information systems (GIS); and descriptive statistics in the assessment of environmental change along the Savannah River Basin of Georgia. Results of the study show that Savannah River basin side of Georgia has been experiencing environmental change due to several decades of relentless pressure induced by anthropocentric activities and host of other socio-economic factors. Normalized Difference Vegetation Index (NDVI) analysis of the area also shows a decline in vegetation cover. The pace of ecological change showed some variations across time and space. Generally, the results point to a decline in water bodies, vegetation, and increase in population, loss of harvested cropland, farms and increasing threats to the environmental systems of the region.
The Value of the Freshwater Snail Dip Scoop Sampling Method in Macroinvertebrates Bioassessment of Sugar Mill Wastewater Pollution in Mbandjock, Cameroon
Authors: Takougang Innocent , Barbazan Phillipe , Tchounwou Paul B. , Noumi Emmanuel
Published: December 2008

Macroinvertebrates identification and enumeration may be used as a simple and affordable alternative to chemical analysis in water pollution monitoring. However, the ecological responses of various taxa to pollution are poorly known in resources-limited tropical countries. While freshwater macroinvertebrates have been used in the assessment of water quality in Europe and the Americas, investigations in Africa have mainly focused on snail hosts of human parasites. There is a need for sampling methods that can be used to assess both snails and other macroinvertebrates. The present study was designed to evaluate the usefulness of the freshwater snail dip scoop method in the study of macroinvertebrates for the assessment of the SOSUCAM sugar mill effluents pollution. Standard snail dip scoop samples were collected upstream and downstream of the factory effluent inputs, on the Mokona and Mengoala rivers. The analysis of the macroinvertebrate communities revealed the absence of Ephemeroptera and Trichoptera, and the thriving of Syrphidae in the sections of the rivers under high effluent load. The Shannon and Weaver diversity index was lower in these areas. The dip scoop sampling protocol was found to be a useful method for macroinvertebrates collection. Hence, this method is recommended as a simple, cost-effective and efficient tool for the bio-assessment of freshwater pollution in developing countries with limited research resources.
Compartmentalization of Aquaporins in the Human Intestine
Authors: Cohly Hari H. P. , Isokpehi Raphael , Rajnarayanan Rajendram V.
Published: December 2008

Improper localization of water channel proteins called aquaporins (AQP) induce mucosal injury which is implicated in Crohn’s disease and ulcerative colitis. The amino acid sequences of AQP3 and AQP10 are 79% similar and belong to the mammalian aquaglyceroporin subfamily. AQP10 is localized on the apical compartment of the intestinal epithelium called the glycocalyx while AQP3 is selectively targeted to the basolateral membrane. Despite the high sequence similarity and evolutionary relatedness, the molecular mechanism involved in the polarity, selective targeting and function of AQP3 and AQP10 in the intestine is largely unknown. Our hypothesis is that the differential polarity and selective targeting of AQP3 and AQP10 in the intestinal epithelial cells is influenced by amino acid signal motifs. We performed sequence and structural alignments to determine differences in signals for localization and posttranslational glycosylation. The basolateral sorting motif “YRLL” is present in AQP3 but absent in AQP10; while Nglycosylation signals are present in AQP10 but absent in AQP3. Furthermore, the C-terminal region of AQP3 is longer compared to AQP10. The sequence and structural differences between AQP3 and AQP10 provide insights into the differential compartmentalization and function of these two aquaporins commonly expressed in human intestines.