bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of hyperosmolarity on the Na+-myo-inositol cotransporter SMIT2 stably transfected in the Madin-Darby canine kidney cell line
Authors: Bissonnette Pierre , Lahjouji Karim , Coady Michael J. , Lapointe Jean-Yves
Published: July 2008

Myo-inositol (MI) is a compatible osmolyte used by cells to compensate for changes in the osmolarity of their surrounding milieu. In kidney, the basolateral Na+-MI cotransporter (SMIT1) and apical SMIT2 proteins are homologous cotransporters responsible for cellular uptake of MI. It has been shown in the Madin-Darby canine kidney (MDCK) cell line that SMIT1 expression was under the control of the tonicity-sensitive transcription factor, tonicity-responsive enhancer binding protein (TonEBP). We used an MDCK cell line stably transfected with SMIT2 to determine whether variations in external osmolarity could also affect SMIT2 function. Hyperosmotic conditions (+200 mosM raffinose or NaCl but not urea) generated an increase in SMIT2-specific MI uptake by three- to ninefold in a process that required protein synthesis. Using quantitative RT-PCR, we have determined that hyperosmotic conditions augment both the endogenous SMIT1 and the transfected SMIT2 mRNAs. Transport activities for both SMIT1 and SMIT2 exhibited differences in their respective induction profiles for both their sensitivities to raffinose, as well as in their time course of induction. Application of MG-132, which inhibits nuclear translocation of TonEBP, showed that the effect of osmolarity on transfected SMIT2 was unrelated to TonEBP, unlike the effect observed with SMIT1. Inhibition studies involving the hyperosmolarity-related MAPK suggested that p38 and JNK play a role in the induction of SMIT2. Further studies have shown that hyperosmolarity also upregulates another transfected transporter (Na+-glucose), as well as several endogenously expressed transport systems. This study shows that hyperosmolarity can stimulate transport in a TonEBP-independent manner by increasing the amount of mRNA derived from an exogenous DNA segment.
Metabolic, enzymatic, and transporter responses in human muscle during three consecutive days of exercise and recovery
Authors: Green Howard J. , Bombardier Eric , Duhamel Todd A. , Stewart Riley D. , Tupling A. Ross , Ouyang Jing
Published: July 2008

This study investigated the responses in substrate- and energy-based properties to repetitive days of prolonged submaximal exercise and recovery. Twelve untrained volunteers (V̇o2peak = 44.8 ± 2.0 ml·kg−1·min−1, mean ± SE) cycled (∼60 V̇o2peak) on three consecutive days followed by 3 days of recovery. Tissue samples were extracted from the vastus lateralis both pre- and postexercise on day 1 (E1), day 3 (E3), and during recovery (R1, R2, R3) and were analyzed for changes in metabolism, substrate, and enzymatic and transporter responses. For the metabolic properties (mmol/kg−1 dry wt), exercise on E1 resulted in reductions ( P < 0.05) in phosphocreatine (PCr; 80 ± 1.9 vs. 41.2 ± 3.0) and increases ( P < 0.05) in inosine monophosphate (IMP; 0.13 ± 0.01 vs. 0.61 ± 0.2) and lactate (3.1 ± 0.4 vs. 19.2 ± 4.3). At E3, both IMP and lactate were lower ( P < 0.05) during exercise. For the transporters, the experimental protocol resulted in a decrease ( P < 0.05) in glucose transporter-1 (GLUT1; 29% by R1), an increase in GLUT4 (29% by E3), and increases ( P < 0.05) for both monocarboxylate transporters (MCT) (for MCT1, 23% by R2 and for MCT4, 18% by R1). Of the mitochondrial and cytosolic enzyme activities examined, cytochrome c oxidase (COX), and hexokinase were both reduced ( P < 0.05) by exercise at E1 and in the case of hexokinase and phosphorylase by exercise on E3. With the exception at COX, which was lower ( P < 0.05) at R1, no differences in enzyme activities existed at rest between E, E3, and recovery days. Results suggest that the glucose and lactate transporters are among the earliest adaptive responses of substrate and metabolic properties studied to the sudden onset of regular low-intensity exercise.
Developmental programming of a reduced nephron endowment: more than just a baby's birth weight
Authors: Moritz Karen M. , Singh Reetu R. , Probyn Megan E. , Denton Kate M.
Published: July 2008

The risk of developing many adult-onset diseases, including hypertension, type 2 diabetes, and renal disease, is increased in low-birth-weight individuals. A potential underlying mechanism contributing to the onset of these diseases is the formation of a low nephron endowment during development. Evidence from the human, as well as many experimental animal models, has shown a strong association between low birth weight and a reduced nephron endowment. However, other animal models, particularly those in which the mother is exposed to elevated glucocorticoids for a short period, have shown a 20–40% reduction in nephron endowment without discernible changes in the birth weight of offspring. Such findings emphasize that a low birth weight is one, but certainly not the only, predictor of nephron endowment and suggests reduced nephron endowment and risk of developing adult-onset disease, even among normal-birth-weight individuals. Recognition of the dissociation between birth weight and nephron endowment is important for future studies aimed at elucidating the role of a reduced nephron endowment in the developmental programming of adult disease.
Role of the kidney in iron homeostasis: renal expression of Prohepcidin, Ferroportin, and DMT1 in anemic mice
Authors: Veuthey Tania , D'Anna María Cecilia , Roque Marta Elena
Published: July 2008

It is known that renal tissue plays a role in normal iron homeostasis. The current study examines kidney function in iron metabolism under hemolytic anemia studying renal expression of Prohepcidin, Ferroportin (MTP1), and divalent metal transporter 1 (DMT1). The relationship between these proteins and iron pigments was also investigated. Immunohistochemical procedures to study renal expression of Prohepcidin, MTP1, and DMT1 were performed in healthy and anemic mice. Renal tissue iron was determined by Prussian blue iron staining. To assess anemia evolution and erythropoietic recovery, we used conventional tests. In healthy mice, Prohepcidin expression was marked in proximal tubules and inner medulla and absent in outer medulla. Cortical tissue of healthy mice also showed MTP1 immunostaining, mainly in the S2 segment of proximal tubules. Medullar tissue showed MTP1 expression in the inner zone. In addition, S2 segments showed intense DMT1 immunoreactivity with homogeneous DMT1 distribution throughout renal medulla. The main cortical findings in hemolytic anemia were in S2 segments of proximal tubules where we found that decreased Prohepcidin expression coincided with an increment in Ferroportin and DMT1 expression. This expression pattern was concomitant with increased iron in the same tubular zone. However, in medullar tissue both Prohepcidin and MTP1 decreased and DMT1 was detected mainly in larger diameter tubules. Our findings clearly demonstrate that in hemolytic anemia, renal Prohepcidin acts in coordination with renal Ferroportin and DMT1, indicating the key involvement of kidney in iron homeostasis when iron demand is high. Further research is required to learn more about these regulatory mechanisms.
Erythropoietin expands a stromal cell population that can mediate renoprotection
Authors: Bi Baoyuan , Guo Jiankan , Marlier Arnaud , Lin Shin Ru , Cantley Lloyd G.
Published: July 2008

Recent studies have demonstrated that erythropoietin (EPO) receptors are expressed on tubular epithelial cells and that EPO can protect tubular cells from injury in vitro and in vivo. Separate studies have demonstrated that marrow stromal cells (MSCs) exert a renoprotective effect in ischemia-reperfusion and cisplatin tubular injury via the secretion of factors that reduce apoptosis and increase proliferation of tubular epithelial cells. In the present study we demonstrate that MSCs express EPO receptors and that EPO can protect MSCs from serum deprivation-induced cell death and can stimulate MSC proliferation in vitro. The administration of EPO to mice resulted in the expansion of CD45-Flk1-CD105+ MSCs in the bone marrow and in the spleen and mobilized these cells as well as CD45-Flk1+ endothelial progenitor cells into the peripheral circulation. Consistent with previous reports, the administration of EPO diminished the decline in renal function associated with cisplatin administration. This effect was partially reproduced by intraperitoneal injection of cultured EPO-mobilized cells in cisplatin-treated mice. Thus the in vivo expansion and/or activation of these cells may contribute to the renoprotective effects of EPO to protect tubular cells from toxic injury.
Effects of dietary salt on renal Na+ transporter subcellular distribution, abundance, and phosphorylation status
Authors: Yang Li E. , Sandberg Monica B. , Can Argun D. , Pihakaski-Maunsbach Kaarina , McDonough Alicia A.
Published: July 2008

During high-salt (HS) diet the kidney increases urinary Na+ and volume excretion to match intake. We recently reported that HS provokes a redistribution of distal convoluted tubule Na+-Cl− cotransporter (NCC) from apical to subapical vesicles and decreases NCC abundance. This study aimed to test the hypothesis that the other renal Na+ transporters' abundance and or subcellular distribution is decreased by HS diet. Six-week-old Sprague-Dawley rats were fed a normal (NS) 0.4% NaCl diet or a HS 4% NaCl diet for 3 wk or overnight. Kidneys excised from anesthetized rats were fractionated on density gradients or analyzed by microscopy; transporters and associated regulators were detected with specific antibodies. Three-week HS doubled Na+/H+ exchanger (NHE)3 phosphorylation at serine 552 and provoked a redistribution of NHE3, dipeptidyl peptidase IV (DPPIV), myosin VI, Na+-Pi cotransporter (NaPi)-2, ANG II type 2 receptor (AT2R), aminopeptidase N (APN), Na+-K+-2Cl− cotransporter (NKCC2), epithelial Na+ channel (ENaC) β-subunit, and Na+-K+-ATPase (NKA) α1- and β1-subunits from low-density plasma membrane-enriched fractions to higher-density intracellular membrane-enriched fractions. NHE3, myosin VI, and AT2R retraction to the base of the microvilli (MV) during HS was evident by confocal microscopy. HS did not change abundance of NHE3, NKCC, or NKA α1- or β1-subunits but increased ENaC-β in high-density intracellular enriched membranes. Responses to HS were fully apparent after just 18 h. We propose that retraction of NHE3 to the base of the MV, driven by myosin VI and NHE3 phosphorylation and accompanied by redistribution of the NHE3 regulator DPPIV, contributes to a decrease in proximal tubule Na+ reabsorption during HS and that redistribution of transporters out of low-density plasma membrane-enriched fractions in the thick ascending limb of the loop of Henle and distal nephron may also contribute to the homeostatic natriuretic response to HS diet.
Activity of the p110-α subunit of phosphatidylinositol-3-kinase is required for activation of epithelial sodium transport
Authors: Wang Jian , Knight Zachary A. , Fiedler Dorothea , Williams Olusegun , Shokat Kevan M. , Pearce David
Published: July 2008

The pathways implicated in the control of epithelial Na+channel (ENaC)-dependent Na+transport in renal collecting duct cells share substantial parallels with those implicated in insulin-regulated glucose metabolism. Notably, both are inhibited by wortmannin and LY294002 and signal through phosphatidylinositol-3-kinase (PI3K)-dependent kinases SGK1 and Akt. The inhibitor pattern is thought to reflect dependence on PI3K activity since wortmannin and LY294002 are both effective inhibitors of this kinase. However, these inhibitors block a variety of kinases from different families and lack specificity within the PI3K family. To begin to dissect more precisely the pathways required for signaling and for control of Na+transport in renal collecting duct cells, we have examined the effect of a set of PI3K inhibitors, which selectively block distinct subsets of PI3K catalytic subunit isoforms. We have found that ENaC-dependent Na+transport was blocked by inhibitors of the p110-α isoform of PI3K, but not by inhibitors of p110-β, -γ, or -δ. Inhibitors that block Na+current also blocked SGK1 and Akt phosphorylation. In contrast to insulin-stimulated glucose uptake in muscle cells, p110-β inhibition did not enhance sensitivity to p110-α inhibition. These data support the conclusion that ENaC-dependent Na+current is controlled exclusively by p110-α, the same isoform that is the principal mediator of insulin effects on glucose metabolism, and lacks any dependence on p110-β. These findings further underscore the extent to which Na+and glucose regulation are intertwined and provide additional insight into the interconnections between diabetes and hypertension.
Rapid exercise-induced changes in PGC-1α mRNA and protein in human skeletal muscle
Authors: Mathai Anila S. , Bonen Arend , Benton Carley R. , Robinson D. L. , Graham Terry E.
Published: July 2008

The mRNA of the nuclear coactivator peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) increases during prolonged exercise and is influenced by carbohydrate availability. It is unknown if the increases in mRNA reflect the PGC-1α protein or if glycogen stores are an important regulator. Seven male subjects [23 ± 1.3 yr old, maximum oxygen uptake (V̇o2 max) 48.4 ± 0.8 ml·kg−1·min−1] exercised to exhaustion (∼2 h) at 65% V̇o2 max followed by ingestion of either a high-carbohydrate (HC) or low-carbohydrate (LC) diet (7 or 2.9 g·kg−1·day−1, respectively) for 52 h of recovery. Glycogen remained depressed in LC ( P < 0.05) while returning to resting levels by 24 h in HC. PGC-1α mRNA increased both at exhaustion (3-fold) and 2 h later (6.2-fold) ( P < 0.05) but returned to rest levels by 24 h. PGC-1α protein increased ( P < 0.05) 23% at exhaustion and remained elevated for at least 24 h ( P < 0.05). While there was no direct treatment effect (HC vs. LC) for PGC-1α mRNA or protein, there was a linear relationship between the changes in glycogen and those in PGC-1α protein during exercise and recovery ( r = −0.68, P < 0.05). In contrast, PGC-1β did not increase with exercise but rather decreased ( P < 0.05) below rest level at 24 and 52 h, and the decrease was greater ( P < 0.05) in LC. PGC-1α protein content increased in prolonged exercise and remained upregulated for 24 h, but this could not have been predicted by the changes in mRNA. The β-isoform declined rather than increasing, and this was greater when glycogen was not resynthesized to rest levels.
Role of Axonal NaV1.6 Sodium Channels in Action Potential Initiation of CA1 Pyramidal Neurons
Authors: Royeck Michel , Horstmann Marie-Therese , Remy Stefan , Reitze Margit , Yaari Yoel , Beck Heinz
Published: July 2008

In many neuron types, the axon initial segment (AIS) has the lowest threshold for action potential generation. Its active properties are determined by the targeted expression of specific voltage-gated channel subunits. We show that the Na+ channel NaV1.6 displays a striking aggregation at the AIS of cortical neurons. To assess the functional role of this subunit, we used Scn8a med mice that are deficient for NaV1.6 subunits but still display prominent Na+ channel aggregation at the AIS. In CA1 pyramidal cells from Scn8a med mice, we found a depolarizing shift in the voltage dependence of activation of the transient Na+ current ( INaT), indicating that NaV1.6 subunits activate at more negative voltages than other NaV subunits. Additionally, persistent and resurgent Na+ currents were significantly reduced. Current-clamp recordings revealed a significant elevation of spike threshold in Scn8a med mice as well as a shortening of the estimated delay between spike initiation at the AIS and its arrival at the soma. In combination with simulations using a realistic computer model of a CA1 pyramidal cell, our results imply that a hyperpolarized voltage dependence of activation of AIS NaV1.6 channels is important both in determining spike threshold and localizing spike initiation to the AIS. In addition to altered spike initiation, Scn8a med mice also showed a strongly reduced spike gain as expected with combined changes in persistent and resurgent currents and spike threshold. These results suggest that NaV1.6 subunits at the AIS contribute significantly to its role as spike trigger zone and shape repetitive discharge properties of CA1 neurons.
Assessment of Individual Finger Muscle Activity in the Extensor Digitorum Communis by Surface EMG
Authors: Leijnse J.N.A.L. , Campbell-Kyureghyan N. H. , Spektor D. , Quesada P. M.
Published: July 2008

The extensor digitorum communis (ED) is a slender muscle group in the dorsal forearm from which tendons arise to the index (D2), medius (D3), ring (D4), and little (D5) fingers. Limited independence has been attributed to the parts that actuate the individual fingers. However, in a detailed anatomical analysis, it was found that the ED parts to the different fingers have constant and widely spaced anatomical locations that promote independent function. These observations and the superficial muscle belly locations prompted the hypothesis that these ED parts would be individually assessable by small anatomically placed surface EMG electrodes. In the present study, this hypothesis was evaluated by measuring electromyography (EMG) from the ED parts and surrounding muscles during individual finger tapping tasks with the forearm resting on a flat surface. It was found that individual ED activity can be well measured in ED2, ED3, ED4, and extensor digiti minimi (EDM). ED3 did not give nor did its electrodes receive significant crosstalk from other ED parts. ED4 electrodes recorded an EMG level of 30 ± 19% (mean ± SD) ED2 EMG in D2 tapping and ED2 electrodes a level of 53 ± 22% ED4 EMG in D4 tapping, by hypothesis mostly crosstalk. EDM electrodes may record EMG at the level of ED4 EMG in D4 tapping. In D2 tapping, the mutual ED2 and extensor indicis redundancy reflected in large intersubject EMG differences with sometimes one or the other almost silent. The results may expand the possibilities of EMG analysis and finger muscle electrostimulation in ergonomic and clinical applications.
Inter- and Intralaminar Subcircuits of Excitatory and Inhibitory Neurons in Layer 6a of the Rat Barrel Cortex
Authors: Kumar Pratap , Ohana Ora
Published: July 2008

Approximately half the excitatory neurons in layer 6 (L6) of the rat barrel cortex project to the thalamus with axon collaterals ramifying in the granular L4; the remaining project within cortex with collaterals restricted to infragranular laminae. In analogy, L6 inhibitory neurons also include locally arborizing and inter-laminar projecting neurons. We examined whether L6 neurons participating in different laminar interactions were also morphologically and electrically distinct. Corticothalamic (CT) neurons were labeled by in vivo injections of a retrogradely transported fluorescent tracer into the primary thalamic nucleus. Whole cell current-clamp recordings were performed from labeled and unlabeled L6 neurons in brain slices of juvenile rats; the morphology of cells was subsequently recovered and reconstructed. Corticocortical (CC) neurons were distinguished from CT cells based on the absence of a subcortical projection and the predominantly infragranular arborization of their axon collaterals. Two morphological CC subtypes could be further distinguished based on the structure of their apical dendrite. Electrically, CT neurons had shorter membrane time-constants and action potential (AP) durations and higher rheobase currents. CC neurons fired high-frequency spike doublets or triplets on sustained depolarization; the burst frequency also distinguished the two morphological CC subtypes. Among inhibitory L6 cells, the L4-projecting (L6iL4) and local (L6iL6) inhibitory neurons also had contrasting firing properties; L6iL4 neurons had broader APs and lower maximal firing rates. We propose that L6 excitatory and inhibitory neurons projecting to L4 constitute specialized subcircuits distinct from the infragranular network in their connectivity and firing patterns.
The Power of Monitoring Stations and a CO2 Fertilization Effect: Evidence from Causal Relationships between NDVI and Carbon Dioxide
Authors: Kaufmann R. K. , Paletta L. F. , Tian H. Q. , Myneni R. B. , D’Arrigo R. D.
Published: July 2008

Two hypotheses are tested: 1) monitoring stations (e.g., Mauna Loa) are not able to measure changes in atmospheric concentrations of CO2 that are generated by changes in terrestrial vegetation at distant locations; 2) changes in the atmospheric concentration of carbon dioxide do not affect terrestrial vegetation at large scales under conditions that now exist in situ, by estimating statistical models of the relationship between satellite measurements of the normalized difference vegetation index (NDVI) and the atmospheric concentration of carbon dioxide measured at Mauna Loa and Point Barrow. To go beyond simple correlations, the notion of Granger causality is used. Results indicate that the authors are able to identify locations where and months when disturbances to the terrestrial biota “Granger cause” atmospheric CO2. The authors are also able to identify locations where and months when disturbances to the atmospheric concentration of carbon dioxide generate changes in NDVI. Together, these results provide large-scale support for a CO2 fertilization effect and an independent empirical basis on which observations at monitoring stations can be used to test hypotheses and validate models regarding effect of the terrestrial biota on atmospheric concentrations of carbon dioxide.
Trends in Intergenerational Class Mobility in Modern Britain: Evidence From National Surveys, 1972—2005
Authors: Goldthorpe John H. , Mills Colin
Published: July 2008

We present analyses of intergenerational social class mobility based on data from representative samples of the British population from 1972 to 2005. We distinguish throughout between absolute and relative rates of mobility. As regards absolute rates, we find little or no change in total mobility rates over the period covered. In the case of men, there is also little change in rates of upward and downward mobility — in contrast with the middle decades of the twentieth century when upward mobility steadily increased while downward mobility fell. This latter pattern does, however, prevail in the case of women. As regards relative rates, we again find, for men and women alike, an essential constancy over time. This, then, indicates that such changes as are apparent in absolute rates derive from shifts in class distributions rather than from any significant increase or decrease in social fluidity. Our results are contrary to the prevailing view in political and media circles that in Britain today the level of social mobility is in decline, although for men the pattern of mobility has become less favourable. We end with some remarks on policy implications.
The Budget Process as Complex Civic Space
Authors: Dennard Linda F.
Published: July 2008

In recent years, there has been a growing interest in the late Aaron Wildavsky's pluralist cultural and political theory. Wildavsky, who is an icon in the policy literature of American public administration, has often been at odds with the rational/linear paradigm that dominated the field of public policy. His work, which has found a new home in complexity theory, spans several disciplines. Yet, the greatest value of Wildavsky's early systems thinking, including his theory of radical incrementalism, may be that it provides both a theoretical base and ethical reasoning with which to meaningfully discuss the possibilities of complexity theory as a new paradigm for governing.
A methodology to support product platform optimization using multi-objective evolutionary algorithms
Authors: Zhongkai Li  , Yixiong Feng  , Jianrong Tan  , Zhe Wei
Published: July 2008

A critical step when designing a successful product family is to determine a cost-saving platform configuration along with an optimally distinct set of product variants that target different market segments. A multi-objective optimization-based platform design methodology (MOPDM) was presented to optimize the individual product performances with a feasible platform commonality level. The process and optimization model for scale-based product platform was constructed firstly, and then the MOPDM was carried out in two stages using the non-dominated sorting genetic algorithm II (NSGA-II). A mechanism based on fuzzy set theory was developed to extract one of the Pareto-optimal solutions as the best compromise one. During the first stage of MOPDM, each product in the family was optimized independently with NSGA-II. Those design variables that show small deviations were held constant to form the product platform. The scaling variables of each instance product were optimized in the second stage. The efficiency and effectiveness of proposed method is illustrated by optimizing a family of six capacitor-run single-phase induction motors, and the results are compared against previous work.
Three-dimensional dynamic modelling of robotic fish: simulations and experiments
Authors: Junzhi Yu  , Lizhong Liu  , Min Tan
Published: July 2008

This paper deals with a three-dimensional (3-D) dynamic model for a free-swimming, multi-link fish-like robot to predict the dynamic characteristics of an artificial fish system using the Schiehlen method in the context of multibody dynamics. The robotic fish, according to propulsive mechanisms employed by fish, propels itself using lateral oscillations and achieves a climb or descent manoeuvre exploiting a pair of pectoral fins. Mechanically, the robotic fish consists of a stiff head, a flexible rear body and an oscillating lunate caudal fin, which can essentially be viewed as an open, tree-like multibody system. The kinematic analysis is then integrated with hydrodynamic analysis on multiple moving elements to derive complete dynamic equations in a form suited for computer implementation as well as controller design. A variety of locomotion behaviours, through regulating parametric sets, can be reproduced. Numerical simulations and actual experiments on degenerative planar swimming and combined motions are finally compared, which partially demonstrate the effectiveness of the built model.
Consequences of Ignoring Guessing When Estimating the Latent Density in Item Response Theory
Authors: Woods Carol M.
Published: July 2008

In Ramsay-curve item response theory (RC-IRT), the latent variable distribution is estimated simultaneously with the item parameters. In extant Monte Carlo evaluations of RC-IRT, the item response function (IRF) used to fit the data is the same one used to generate the data. The present simulation study examines RC-IRT when the IRF is imperfectly matched to the data. In particular, guessing is ignored: The two-parameter logistic IRF is fitted to data generated from the three-parameter logistic IRF. The empirical histogram method (EHM) implemented in the BILOG-MG program is also applied for comparison. Results indicate that apparent nonnormality in a density estimate from either RC-IRT or the EHM can be entirely due to misspecification of the IRF, and it may be difficult to tell which IRF is best when the latent density is estimated. It is recommended that practitioners first identify the best IRF with the latent density fixed at normal and then subsequently examine the normality assumption about the latent density.
Complexity Theory and School Reform
Authors: Siu Wanda
Published: July 2008

There is a paucity of studies that assess the influence of communication in facilitating educational change. The purpose of this study was to examine the role of communication for high school principals in the implementation of education reform. Overall, the study found that top-down communication strategy was more prevalent in high schools. These findings are consonant with complexity theory, which posits that self-organizing activities are best promoted by interactions and connection among staff members.
Examining Male Underachievement in Public Education
Authors: Clark Mary Ann , Sang Min Lee  , Goodman William , Yacco Summer
Published: July 2008

Educational statistics and worldwide media have reported a gender gap in academic achievement, with boys falling behind girls with regard to grades, high school graduation, and college enrollment and retention. This mixed methods study involved interviews with educators and the examination of quantitative data to investigate this issue in a school district. Local results mirrored national statistics regarding gender differences in achievement and school success factors. Themes are explored and recommendations are made to enhance school success skills for male students.
Being a Sociologist and Becoming a Whiteheadian
Authors: Halewood Michael , Michael Mike
Published: July 2008

This article is an attempt to operationalize A.N. Whitehead's ontological approach within sociology. Whitehead offers lessons and clues to a way of re-envisioning `sociological practice' so that it captures something of the nature of a `social' that is at once real and constructed, material and cultural, and processual and actual. In the course of the article, the terms `operationalize' and `sociology' will themselves be transformed, not least because the range of objects and relations of study will far outstrip those common to sociology; further, the term `operationalize' would seem to retain the notion of a stable sociologist-subject translating precepts into methods. So, the article will follow Whitehead's shift in emphasis toward an understanding of much more relational, heterogeneous and emergent entities — which in turn will require new methodological approaches. In staking out these claims, we follow in an intellectual lineage in which Whitehead's presence has been profound but generally oblique. For it is clear that, while Whitehead has informed various writing, little attempt has been made to draw out, more or less systematically, some of the general methodological tactics that would allow us to practise a Whiteheadian sociology.
The Effect of Local Anesthetics Administered via Pain Pump on Chondrocyte Viability
Authors: Dragoo Jason L. , Korotkova Tatiana , Kanwar Raj , Wood Billy
Published: July 2008

Background

Chondrolysis initiated by postoperative, intra-articular pain pumps has recently been described by multiple institutions.

Purpose

To evaluate the in vitro chondrotoxicity of anesthetic formulations commonly used in pain pumps.

Study Design

Controlled laboratory study.

Methods

Freshly isolated human articular chondrocytes were cultured for 24-, 48-, and 72-hour trials in a custom bioreactor that mimics the metabolism of synovial fluid. Chondrocytes were perfused in Dulbecco's Modified Eagle's Medium 10% fetal bovine serum and one of the following medications: 1 % lidocaine, 1 % lidocaine with epinephrine, 0.25% bupivacaine, 0.25% bupivacaine with epinephrine, 0.5% bupivacaine, or 0.5% bupivacaine with epinephrine. Static and perfusion cultures with growth media were used as controls. All experiments were run in duplicate. Live/dead staining was performed, and the ratio of dead: Live cells was assessed by fluorescent microscopy and histomorphometry.

Results

Significantly more chondrocyte necrosis was found in all cultures with medications containing epinephrine ( P < .05) at all time points. Similar necrosis rates were exhibited in 0.25% and 0.5% bupivacaine compared with controls at 24 and 48 hours. However, 0.5% bupivacaine produced significantly more cell death at 72 hours. Similar necrosis rates were exhibited with 1 % lidocaine compared to controls at 24 hours.

Conclusion

In this in vitro model, 0.25% and 0.5% bupivacaine caused minimal chondrocyte necrosis when used in pain pumps for a maximum of 48 hours. All anesthetics containing epinephrine (pH  4) were chondrotoxic and cannot be advocated for pain pump use. The use of 0.5% bupivacaine for greater than 48 hours is not recommended.

Clinical Relevance

The results of this study may help improve the safety of intra-articular pain pump use by examining the effects of local anesthetics on chondrocyte viability.
Pediatric Sciatic Neuropathies Due to Unusual Vascular Causes
Authors: Srinivasan Jayashri , Escolar Diane , Ryan Monique , Darras Basil , Jones H. Royden
Published: July 2008

Four cases of pediatric sciatic neuropathies due to unusual vascular mechanisms are reported. Pediatric sciatic neuropathies were seen after umbilical artery catheterization, embolization of arteriovenous malformation, meningococcemia, and hypereosinophilic vasculitis. Electrophysiologic studies demonstrated abnormalities in motor studies of peroneal and tibial nerves. Sensory studies demonstrated abnormalities of sural and superficial peroneal nerves. Results of needle electromyography were abnormal in sciatic-innervated muscles. Prognosis was variable and depended on the severity of the initial nerve injury.
Choroid Plexus Hyperplasia and Monosomy 1p36: Report of New Findings
Authors: Puvabanditsin Surasak , Garrow Eugene , Patel Neisha , D'Elia Alexis , Zaafran Ahmed , Phattraprayoon Nanthida , Davis Suzanne Elizabeth
Published: July 2008

Monosomy 1p36 is a newly delineated multiple congenital anomalies/mental retardation syndrome characterized by mental retardation, growth delay, epilepsy, congenital heart defects, characteristic facial appearance, and precocious puberty. It is now considered to be one of the most common subtelomeric micro-deletion syndromes. This article reports new findings of choroid plexus hyperplasia and dextrocardia with situs solitus in a patient who had deletion of chromosome 1p26.33 with a brief review of the literature.
Infected Lumbar Dermoid Cyst Presenting With Tetraparesis Secondary to Holocord Central Lesion
Authors: Tufan Kadir , Cekinmez Melih , Sener Levent , Erdogan Bulent
Published: July 2008

We report an unusual case of a 6-year-old boy with a sinus tract terminating with an intramedullary dermoid cyst and holocord central lesion, presenting with tetraparesis secondary to intramedullary abscess. Total excision of dermal sinus tract, dermoid cyst, and the intramedullary abscess by means of a L2–S3 laminectomy, followed by antibiotic therapy resulted in good functional recovery. Strengths of the upper extremities have fully recovered, and a remarkable improvement was detected in the muscles of the lower extremities. Postoperative magnetic resonance imaging (MRI) of the spine showed complete removal of the dermoid cyst, decreased inflamed granulation tissue over the medullary conus, and disappearance of the holocord high intensity lesion. The pathomechanism of holocord central lesion is discussed herein.
Resolution of Brachial Plexus Palsy Due to Hemangioma After Intravenous Corticosteroid Therapy
Authors: Naqvi Ali H. , Alfonso Daniel T. , Flores Patricia , Grossman John A. I. , Restrepo Ricardo , Alfonso Israel
Published: July 2008

The authors report a 7-day-old girl born with a hemangioma involving the right side of the scalp and neck who developed ipsilateral brachial plexus palsy at 5 days of age. Imaging studies confirmed the presence of a cavernous hemangioma in the vicinity of the brachial plexus. She was treated with intravenous corticosteroids and her palsy resolved in 5 days. Only 1 prior case of hemangioma producing brachial plexus palsy has been reported; this patient was not treated with corticosteroids and had a partial recovery. The authors believe that the quick recovery after initiating systemic steroids was due to relief of nerve compression (neuropraxia) resulting from shrinkage of the cavernous hemangioma. The purpose of this article is to describe an uncommon cause of neonatal brachial plexus palsy and to report the effectiveness of early intravenous corticosteroid treatment in a patient with brachial plexus palsy due to a cavernous hemangioma.
Progressive Leukoencephalopathy Associated With Aluminum Deposits in Myelin Sheath
Authors: Itoh Masayuki , Suzuki Yoshiko , Sugai Kenji , Ozuka Naofumi , Ohsawa Maki , Otsuki Taisuke , Goto Yu-ichi
Published: July 2008

A 20-year-old woman with progressive leukoencephalopathy developed mental and motor disabilities and fell into a coma after suffering head trauma and febrile episodes from infancy. Brain imaging showed massive abnormal signals in the white matter. The electron spectroscopic imaging of biopsied brain tissue confirmed the electron-dense deposits to be associated with aluminum accumulation in the myelin sheath. Her brain pathology, which showed ferritin- and naphtochrome green-positive deposits, supported the imaging analysis. The clinicopathological features indicate a new form of progressive leukoencephalopathy.
Like Father, Like Son: Periventricular Nodular Heterotopia and Nonverbal Learning Disorder
Authors: McCann Marcia V. , Pongonis Stephen J. , Golomb Meredith R. , Edwards-Brown Mary , Christensen Celanie K. , Sokol Deborah K.
Published: July 2008

Periventricular nodular heterotopia is a common malformation of cortical development in which the migration of developing neurons destined for the cerebral cortex is abbreviated. Bilateral periventricular nodular heterotopia is most commonly an X-linked disorder that involves mutations in the filamin A (FLNA) gene, but an autosomal recessive form and sporadic forms have been identified. To our knowledge, autosomal dominant transmission of isolated periventricular nodular heterotopia has not been reported. Periventricular nodular heterotopia has a heterogeneous phenotype, associated commonly with seizure disorder, and more recently with reading deficits and visual-spatial deficits in some patients. We present a father and son with bilateral periventricular nodular heterotopia and similar visual–spatial learning deficits, consistent with nonverbal learning disability.
Feasibility and Clinical Utility of Early Electroencephalogram (EEG) in Children With First Seizure
Authors: Hamiwka Lorie , Singh Neetu , Kozlik Silvia , Wirrell Elaine
Published: July 2008

The feasibility and clinical utility of early electroencephalogram (within 48 hours) was studied in 127 children (age, 1 month-17 years) referred for a “first seizure.” The electroencephalogram was considered late after 48 hours. Electroencephalogram abnormalities were classified as nonepileptiform or epileptiform. Children were classified as having an “epileptic” or “nonepileptic” event. An early electroencephalogram was obtained in 23 (18%). Late referral (n = 36), weekend event (n = 23), difficulty contacting families (n = 11), parental schedules (n = 9), and laboratory scheduling (n = 11) resulted in late electroencephalograms. All 94 children with an epileptic event had an electroencephalogram, 19 (20%) within 48 hours. Results were abnormal in 9 (47%) early (7 epileptiform, 2 nonepileptiform) and 35 (44%) late (30 epileptiform, 5 nonepileptiform). Increased abnormalities were not seen with early electroencephalography ( P = .50). Early electroencephalograms may not be feasible in the pediatric population and did not show a higher yield of abnormalities.
Neurological and Magnetic Resonance Imaging Findings in Children With Developmental Language Impairment
Authors: Webster Richard I. , Erdos Caroline , Evans Karen , Majnemer Annette , Saigal Gaurav , Kehayia Eva , Thordardottir Elin , Evans Alan , Shevell Michael I.
Published: July 2008

Neurologic and radiologic findings in children with well-defined developmental language impairment have rarely been systematically assessed. Children aged 7 to 13 years with developmental language impairment or normal language (controls) underwent language, nonverbal cognitive, motor and neurological assessments, standardized assessment for subtle neurological signs, and magnetic resonance imaging. Nine children with developmental language impairment and 12 controls participated. No focal abnormalities were identified on standard neurological examination. Age and developmental language impairment were independent predictors of neurological subtle signs scores (r2 = 0.52). Imaging abnormalities were identified in two boys with developmental language impairment and no controls ( P = .17). Lesions identified were predicted neither by history nor by neurological examination. Previously unsuspected lesions were identified in almost 25% of children with developmental language impairment. Constraints regarding cooperation and sedation requirements may limit the clinical application of imaging modalities in this population.
Effectiveness of Selective Dorsal Rhizotomy in 2 Patients With Progressive Spasticity Due to Neurodegenerative Disease
Authors: Grunt Sebastian , van der Knaap Marjo S. , van Ouwerkerk Willem J. R. , Strijers Rob L. M. , Becher Jules G. , Vermeulen R. Jeroen
Published: July 2008

Selective dorsal rhizotomy at the lumbar level is a neurosurgical procedure, which reduces spasticity in the legs. Its effect has mainly been studied in children with spastic cerebral palsy. Little is known about the outcome of selective dorsal rhizotomy in patients with neurodegenerative disorders. We report the clinical course after selective dorsal rhizotomy in 2 patients with progressive spasticity. Leg spasticity was effectively and persistently reduced in both patients, facilitating care and improving sitting comfort. However, spasticity of the arms and other motor disturbances, such as spontaneous extension spasms and the ataxia, increased gradually in time. Selective dorsal rhizotomy leads to a disappearance of leg spasticity in patients with a neurodegenerative disease. Other motor signs are not influenced and may increase due to the progressive nature of the underlying disease.
Expanding the Neurologic Phenotype of Oculodentodigital Dysplasia in a 4-Generation Hispanic Family
Authors: Amador Claudia , Mathews Anne M. , del Carmen Montoya Maria , Laughridge Mary E. , Everman David B. , Holden Kenton R.
Published: July 2008

We report a 4-generation Hispanic family with oculodentodigital dysplasia whose members were found to have typical phenotypic characteristics of this disorder, as well as a variable expression of neurologic manifestations in multiple generations ranging from a mild spastic gait to moderate to severe spastic tetraparesis/quadriplegia with epilepsy and an abnormal brain and spinal cord magnetic resonance imaging result. Gene testing documented a previously reported missense mutation in GJA1 (connexin 43) exon 2 (c.389T>C;p.I130T). Our evaluation not only expands the phenotypes associated with GJA1 gene mutations but also demonstrates that a great degree of variability in neurological defects can exist within a single family without evidence of genetic anticipation. A genotype-phenotype correlation between the p.I130T mutation and neurologic dysfunction appears more likely with the addition of this report's neurologic and GJA1 gene mutation findings. These findings expand the neurologic phenotype and prognosis and underscore the importance of counseling families with oculodentodigital dysplasia about the possibility of neurologic involvement.
“Working rules for financial statements” and pre-Second World War financial reporting of Japanese industrial firms: the case of chemical firms
Authors: Noguchi Masayoshi , Nakajima Michiyasu
Published: July 2008

The purpose of this study is (1) to explore how financial reporting was practised under the condition of shareholders' effective governance that operated in Japanese industrial firms in the pre-Second World War period and (2) to investigate reasons why the Working Rules for Financial Statements issued in 1934 had no important impact upon financial reporting practice by examining empirical data for the pattern of reporting adopted by 18 chemical firms. The study demonstrates that the reason for the absence of practical impact of the Working Rules was not simply the lack of enforcement power, as suggested in prior studies, but that financial reporting practice was influenced by: an extreme concealment policy founded on the unfinished separation of management from ownership; the formation of the new business concerns in the Japanese chemical industry; and a prolonged industrial slump in the chemical industry during the 1920s and the early 1930s.
Role of Dopamine in the Motivational and Cognitive Control of Behavior
Authors: Cools Roshan
Published: July 2008

Brain dopamine has often been implicated in impulsive and/or inflexible behaviors, which may reflect failures of motivational and/or cognitive control. However, the precise role of dopamine in such failures of behavioral control is not well understood, not least because they implicate paradoxical changes in distinct dopamine systems that innervate dissociable neural circuits. In addition, there are large individual differences in the response to dopaminergic drugs with some individuals benefiting from and others being impaired by the same drug. This complicates progress in the understanding of dopamine's role in behavioral control processes, but also provides a major problem for neuropsychiatry, where some individuals are disproportionately vulnerable to the adverse effects of dopamine-enhancing drugs on motivation and cognition. Recent progress is reviewed from cognitive and behavioral neuroscience research on motivation and cognitive control, which begins to elucidate the factors that mediate the complex roles of mesolimbic, mesocortical, and nigrostriatal dopamine in behavioral control. NEUROSCIENTIST 14(4):381–395, 2008. DOI: 10.1177/1073858408317009
Should SDMT substitute for PASAT in MSFC? A 5-year longitudinal study
Authors: Brochet B , Deloire MSA , Bonnet M , Salort-Campana E , Ouallet JC , Petry KG , Dousset V
Published: July 2008

Background

The multiple sclerosis functional composite (MSFC) includes the Paced Auditory Serial Addition test (PASAT) as a measure of cognition.

Objectives and methods

We compared the MSFC incorporating the Symbol Digit Modalities test (SDMT) (MSFC [sdmt]) to the usually applied MSFC (MSFC [pasat]) in a sample of 46 ptients with relapsing–remitting MS who were followed over a five-year period. Magnetic resonance imaging was performed at baseline.

Results

The Expanded Disability Status scale (EDSS) deteriorated significantly over 5 years ( P < 0.01), but MSFC scores remained stable. MSFC [sdmt] correlated with EDSS at all time points of evaluation, but MSFC [pasat] correlated with EDSS only at baseline, 1, and 5 years. The 5-year EDSS correlated significantly with baseline MSFC [sdmt] and MSFC [pasat] but did not correlate after adjustment for baseline EDSS. No significant correlation was found at baseline between MSFC and imaging parameters (lesion load, brain parenchymal fraction [BPF], ventricular fraction, mean magnetization transfer ratio of lesions and normal-appearing brain tissue), but baseline BPF correlated significantly with changes of SDMT z score ( P = 0.0003), MSFC [pasat] ( P = 0.006), and MSFC [sdmt] ( P = 0.0002) over 5 years.

Conclusion

We propose not to substitute PASAT by SDMT in the MSFC but to consider SDMT as a complementary useful approach to evaluate overall MS disease.