bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of occupation and safety practices with work-injury absence among public hospital employees in Latin America: a study from Costa Rica
Authors: Gimeno David , Felknor Sarah A , Burau Keith D , Delclos George L , Barrientos-Gutiérrez Tonatiuh
Published: August 2007

Background:Injury-related statistics in developing countries are rare.

Objective:To assess the relationship between occupational and safety-related risk factors and absences from work during the preceding 6 months due to work-related injury among public hospital employees in Costa Rica.

Methods:Data were used from a cross-sectional survey conducted in December 2000 among a stratified random sample of 1000 employees from 10 of the 29 public hospitals in Costa Rica. The questionnaire included sociodemographic data, occupational exposures, and organizational risk factors. A dichotomous variable was created to indicate work-injury absence. At-risk employees (n = 466) were classified as having had a work-injury absence if they reported having been absent for at least 1 day in the preceding 6 months because of a work-related injury. OR and 95% CI were calculated using unconditional logistic regression models.

Results:There is a greater likelihood of injury-related absence in non-professional occupational positions (ie, auxiliary personnel (OR = 2.29) and general services employees (OR = 5.55)) than in professional positions, and in employees who show poor compliance with safety practices (OR = 2.03) and have high interference from their job task (OR = 3.79) compared with their counterparts.

Conclusions:Work-injury absence appears not only to be a function of work injury, but also a function of occupation and degree of compliance with safety practices.
Effect of vegetative competition on the moisture and nutrient status of loblolly pine
Authors: Carter G. A. , Miller J. H. , Davis D. E. , Patterson R. M.
Published: August 2007

A field study examined the effects of competing vegetation on the moisture and nutrient status of 5-year-old loblolly pines (Pinustaeda L.). Similar experiments were conducted on a Piedmont site and a Coastal Plain site using individual pines as experimental units. Predawn measurements of xylem pressure potential were made using detached needle fascicles, and nutrient concentrations in soil and foliage samples were determined monthly. This study was conducted during the 3rd year of a relatively dry 3-year period. On the Piedmont site, elimination of all competing vegetation within 1.5 m of the pines significantly lowered moisture stress when compared with the no-elimination treatment; on the Coastal Plainee site, differences were significant on only half of the assay dates. Removing only arborescent vegetation on the Piedmont site reduced pine water stress one-half as much as removing all vegetation, but on the Coastal Plain site this reduction was about two-thirds of that found following removal of all vegetation. As drought length increased, stress increased, regardless of treatment. Higher levels of competing vegetation significantly reduced available potassium, calcium, magnesium, and manganese concentrations in the loamy sand of the Coastal Plain site, but only potassium was reduced on the Piedmont. None of the treatments significantly affected foliar nutrients at either site.
Changes in attitudes to solid timber species: a test of some promotional elements
Authors: Cooper R. J. , Kalafatis S.
Published: August 2007

The significance of two promotional elements (presentation and product) in explaining the variations in the attitudes towards timber species are examined in this paper. In measuring such attitudes, the original Fishbein model is used and the attitudes are expressed as a function of five pretested attributes (beauty, durability, smoothness of texture, coldness, and modernity). A detailed ANOVA showed that variations in attitudes were explained mainly by the type of product and to a lesser extent by the two-way interactions of product and the species used to produce the product while the type of presentation was not significant. It was found that the respondents had certain preconceived ideas about the properties of individual species and these ideas were directly related to products and (or) applications traditionally associated with each species. Finally, the multidimensional model of "utilities," UNICON was applied to the data. Two analyses were performed, one on the utilities of the different products, species, and types of presentation and one on the utilities of the different attributes tested. The findings corroborated those of the analysis of variance. Very different utility factors were attached to different combinations of products made out of different species while the type of presentation was not significant. Therefore, for promotional purposes a very detailed and segmented approach is needed and this will depend on the particular product and the species used and consequently different attributes must be emphasised and promoted.
A 10-year tree and stand response of jack pine to urea fertilization and low thinning
Authors: Groot Arthur , Brown Kenneth M. , Morrison Ian K. , Barker J. E.
Published: August 2007

This study examined the 10-year effects of a light (20% basal area removed) low thinning and urea fertilization (336 kg N/ha) on a 45-year-old Pinusbanksiana Lamb. stand. Thinning had no effect other than salvaging potential mortality, while fertilization resulted in an average annual gross volume growth response of about 2 m3 ha−1 year−1. Volume growth response to fertilization was greatest in the largest diameter trees, and continued until 10 years after treatment. Growth response did not begin until the second growing season after treatment. There were indications that fertilization had positive effects on form factor.
Mobilization of recently formed forest soil organic sulfur
Authors: Strickland T. C. , Fitzgerald J. W. , Swank W. T.
Published: August 2007

Soils from a mixed mature hardwood forest were assayed for their capacity to mobilize sulfur which had been previously immobilized into a nonsalt-extractable (insoluble) form. These soils rapidly released soluble organic sulfur and inorganic sulfate from this fraction. It is suggested that the former component is a depolymerization product of a more complex organic sulfur matrix. The activity of preformed extracellular depolymerase and sulfohydrolase enzymes in the soil may be responsible for the depolymerization and subsequent desulfation of the organic sulfur matrix. This is supported by observations that treatment of soil samples with sodium sulfate, sodium azide, erythromycin, or candicidin failed to inhibit the capacity of A1-horizon soils to mobilize the organic sulfur fraction. The rates and final levels of sulfur mobilization increased with an increase in temperature and decreased with sample depth.
Predicting fuel moisture in jack pine slash: a test of two systems
Authors: Simard Albert J. , Eenigenburg James E. , Blank Richard W.
Published: August 2007

Observed jack pine (Pinusbanksiana Lamb.) slash moisture was compared with U.S. National Fire-Danger Rating System (NFDRS) and Canadian Fire Weather Index (FWI) predictions. The NFDRS models underestimated wood and foliage moisture; the FWI models overestimated wood moisture but were accurate for foliage moisture. Differences in predictive accuracy between the two sets of regression equations were not significant. The NFDRS equations were somewhat more data dependent, however, and their residuals tended to be biased. Significant differences in moisture profiles were noted among three fuel size classes, between fuels with and without bark, and between litter and needles. Differences between fuels on the ground and above the ground were not significant. The results should be applicable to most fuels influenced by moist climates.
Role of stratification, temperature, and light in Fraser fir germination
Authors: Adkins Craig R. , Hinesley L. Eric , Blazich Frank A.
Published: August 2007

Fraser fir (Abiesfraseri (Pursh) Poir.) germination was examined as affected by cold–moist stratification, temperature, and light. There were strong interactions among these factors in the germination response. Germination was accelerated by cold–moist stratification and (or) warm germination temperatures. Stratification periods up to 12 weeks improved germination at low temperatures (8-/16-h thermoperiod of 20/10 °C, respectively), whereas 8 weeks was sufficient for seed germinated at high temperatures (30/20 °C). Germination was influenced by temperature regime, but temperature and light sensitivity decreased with increased durations of stratification. Except at low temperatures, a close relationship existed between daily heat input and germination. Maximum germination occurred at 500–600 degree-hours per 24-h cycle. A 1-h daily light treatment during the 8-h temperature cycle broadened the temperature range for optimum germination. For a 42-day germination period, the effect of a daily 1-h light treatment was essentially equivalent to 4 weeks stratification at 4 °C.
EL-500: an effective growth retardant for dwarfing southern pine seedlings
Authors: Hare Robert C.
Published: August 2007

Seed-orchard operations would benefit if trees could be kept short without sacrificing seed yield on a given area. To test the feasibility of chemical dwarfing, five growth-retarding chemicals were applied to foliage or bark of 2-year-old loblolly (Pinustaeda L.) and slash (P. elliottii Engelm. var. elliottii) pines in February. The most effective chemical for reducing height growth without toxicity was EL-500 (α-(l-methylethyl)-α-(4-(trifluoromethoxy)phenyl)-5-pyrimidinemethanol), a compound related to ancymidol (α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol). It reduced 1-year growth to about half that of the controls in both species when applied as an aqueous foliar spray or an oil-based bark band. Although the dwarfed growth appeared otherwise normal, the possible effects of EL-500 on future flowering and seed yield have yet to be determined.
Biomass predicted by soil-site factors: a case study in north central West Virginia
Authors: Frank Jr. P. S. , Hicks Jr. R. R. , Harner Jr. E. J.
Published: August 2007

Soil-site characteristics and the biomass of trees larger than 5 cm dbh (diameter at breast height) were measured in a 50-year-old hardwood forest on a 269-ha watershed on the Allegheny Plateau. A weighted stepwise multiple regression model explained 65% of the variation in biomass. The significant variables were, in order of importance: aspect; iron and copper in the B horizon; lime requirement and calcium in the A horizon; calcium in the B horizon; surface stoniness; A horizon manganese, potassium, and iron.
The effectiveness of mycelial slurries of mycorrhizal fungi for the inoculation of container-grown jack pine seedlings
Authors: Danielson R. M. , Visser S. , Parkinson D.
Published: August 2007

Mycelial slurries prepared from agar plates of ectomycorrhizal fungi were used to inoculate 7-week-old container-grown jack pine. Seven of 15 species formed mycorrhizae after 18 weeks and included Thelephoraterrestris Ehrhart ex Fr., Laccariaproximo Boudier, Hebeloma sp., Pisolithustinctoris (Pers.) Coker & Couch, Sphaerosporellabrunnea (Alb. & Schw. ex Fr.) Svrcek & Kubicka, Cenococcwngeophilum Fr., and an E strain (sensu Mikola) isolate. Species of Tricholoma, Suillus, Amphinema, and Hydnum failed to form mycorrhizae. The use of a mycelial slurry has the advantage of saving considerable time in inoculum preparation and should be useful for experimental purposes.
Growth and acetylene reduction of black alder seedlings in response to water stress
Authors: Seiler John R. , Johnson Jon D.
Published: August 2007

Black alder, Alnusglutinosa (L.) Gaertn., seedlings were grown and kept well watered for 10 weeks, and then subjected to moisture stress conditioning for 5 subsequent weeks, where one-half of the seedlings were watered only when visibly wilted. The remaining seedlings (controls) were kept well watered. Moisture stress conditioning greatly reduced shoot, root, nodule, and total plant dry weight. The root–shoot ratio (grams/grams) of seedlings was significantly increased from 0.28 in the control seedlings to 0.33 in the water-stressed treatment. Acetylene reduction rates decreased only slightly in the range of water potentials between −0.50 and −1.29 MPa, then dropped rapidly below water potentials of −1.30 MPa. Moisture stress conditioning had no significant influence on this response. Although not significantly different, leaf and nodule osmotic potentials were consistently lower in the water-stressed plants.
Estimation of twig xylem water potential in young Douglas-fir trees
Authors: Kelliher F. M. , Black T. A. , Barr A. G.
Published: August 2007

Methodology, based on water flow theory, is described which can be used to estimate twig xylem water potential for 10–15 m tall Douglas-fir (Pseudotsugamenziesii) (Mirb.) Franco) trees. Using pressure chamber measurements, values of needle xylem water pressure potential were found to be similar to twig xylem water pressure potential. For root zone soil water potential (ψs) > −0.4 MPa, measured predawn total twig xylem water potential (ψTtx) of these Douglas-fir trees was significantly less than ψs. A transpiration rate (E) dependent single soil to twig liquid resistance (Rst) accounted for the difference between predawn ψTtx and ψs. For ψs > −0.4 MPa, during the daytime when E was high, Rst could be described by a logarithmic function of ψs. The effect of capacitance on twig xylem water potential (ψtx) was small. A model incorporating the transpiration dependent Rst accurately estimated the course of ψtx on a clear day when ψs was −0.04 MPa.
An instrument for measuring the average stomatal conductance of conifer seedlings
Authors: Livingston N. J. , Black T. A. , Beames D. , Dunsworth B. G.
Published: August 2007

A ventilated, transient-type porometer was designed to nondestructively measure the average stomatal conductance of conifer seedlings. The porometer consists of a low-power microprocessor unit and a stainless steel chamber which encloses the seedling. Conductance is calculated from the measured rate of increase in chamber relative humidity above the ambient level. Consequently, chamber air does not have to be dried prior to measurement. Direct readout of stomatal conductance is provided by means of a liquid crystal display and a serial (RS232) port. Porometer calibration over a range of humidities showed that the effective chamber volume was consistently 25% larger than the actual chamber volume. Stomatal conductance measurements made on Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings using the porometer agreed well with average values obtained with a ventilated diffusion porometer using four needle samples. The porometer proved to be very convenient to use in a forest clearcut environment, with the measurement procedure taking about 1 min. Measurements can be made on a seedling over the growing season because the use of the instrument causes no injury to stem, branches, and needles.
Price elasticities for softwood plywood and structural particleboard in the United States
Authors: Spelter Henry
Published: August 2007

A multiequation model analyzing the price elasticities for construction panels (softwood plywood and structural particleboard) was developed. The response of softwood plywood demand to price was found to have declined substantially over the 30-year span of analysis, dropping from an estimated 0.83 in 1950 to 0.10 in 1981. This decline indicates the maturing of softwood plywood markets and the limited growth opportunities for the product. The price elasticity of structural particleboard, by contrast, was estimated at substantially higher levels in the late 1970's. These particleboards compete for some of the same markets as softwood plywood and are priced at substantial discounts in most markets. The model results indicate the demand for structural particleboards is highly sensitive to price, and pricing will be a key variable determining its growth.
Variations in beech bark disease and its effects on species composition and structure of northern hardwood stands in central New England
Authors: Twery Mark J. , Patterson III William A.
Published: August 2007

The extent of beech bark disease was examined on 41 permanent inventory plots in western Massachusetts and on 25 plots in Bartlett Experimental Forest in New Hampshire. The amounts of disease-caused mortality and defect were correlated to differences in species composition and 12 other site variables. Stands dominated by hemlock had significantly more beech mortality than other stands. Importance of both beech and yellow birch decreased on plots with beech bark disease mortality. Hemlock benefited most from the loss of beech. Beech bark disease has not noticeably changed understory composition on these plots. In the long term, beech bark disease appears to have caused minor compositional changes on most of the areas studied.
Optimal staffing of a forest fire fighting organization
Authors: Aneja Yash P. , Parlar Mahmut
Published: August 2007

This paper deals with finding the optimal size of a forest fire fighting organization. Fire occurrence and fire growth rate are assumed to be random variables with given probability densities. An objective function representing the expected cost is developed by using probabilistic arguments. The resulting nonlinear programming problem with nonnegativity constraints is solved and an extensive sensitivity analysis is presented for cost related and noncost parameters of the problem.
Asymbiotic N2-fixing bacteria associated with three boreal conifers
Authors: Florence L. Z. , Cook F. D.
Published: August 2007

Azotobacter spp., Azospirillum spp., and Desulfovibrio spp., were identified as the predominant nitrogen-fixing bacteria associated with seedling root sections collected from natural stands of Pinusbanksiana Lamb., Piceamariana (Mill.) B.S.P., and Larixlaricina (Du Roi) K. Koch growing in Alberta. Samples from the sandy upland habitat of P. banksiana exhibited lower average rates of nitrogen fixation relative to the wet lowland occupied by P. mariana and L. laricina. Average nitrogen-fixing capacity (by acetylene reduction) was greater among bacteria isolates from L. laricina than those from P. mariana. Azospirillum spp. were strongly associated with P. mariana, while Azotobacter spp. were isolated more frequently from L. laricina.
Response of loblolly pine and sweetgum seedlings to oxyfluorfen
Authors: South David B.
Published: August 2007

Oxyfluorfen (2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene) was applied at a rate equivalent to a field application rate of 3 kg active ingredient/ha to seed and to 1- to 6-week-old seedlings of loblolly pine (Pinustaeda L.) and sweetgum (Liquidambarstyraciflua L.) under greenhouse conditions. Loblolly pine was more tolerant of oxyfluorfen than sweetgum at all ages. Emergence of sweetgum was completely inhibited by oxyfluorfen, while loblolly pine seedling emergence was reduced by 33%. Tolerance to oxyfluorfen by both species increased with increasing seedling age. Except for the 6-week-old loblolly pine seedlings, dry weights of shoots and roots of treated seedlings were lower than controls. Oxyfluorfen injured the apical meristem of sweetgum at all ages but meristems of loblolly pine seedlings older than 2 weeks did not show any injury.
The Rule of Law
Authors: Ohnesorge John K.M.
Published: August 2007

Rule of Law rhetoric is increasingly common, both in U.S. legal literature and in the realm of international governance. In the field of law and economic development, the Rule of Law revival is lead by the international financial institutions (IFIs). Rule of Law discourse has also come to play an important role in the fields of comparative politics and comparative law, particularly with respect to East Asia. This review begins with a discussion of Rule of Law rhetoric in the Anglo-American tradition. It then discusses the international Rule of Law renaissance, focusing on the roles that Rule of Law rhetoric plays in the development activities of the IFIs. Because the claim is that the Rule of Law is key to economic development, this review explores the extent to which Northeast Asia's outstanding economic development conformed to the Rule of Law. An exploration follows of how the Rule of Law–economic development literature has evolved over time, in line with changing ideas about economics and about development itself. Finally, this review explores how Rule of Law is used in the literatures of comparative politics and comparative law.
Vasopressin is a physiological substrate for the insulin-regulated aminopeptidase IRAP
Authors: Wallis Michelle G. , Lankford Miles F. , Keller Susanna R.
Published: August 2007

Insulin-regulated aminopeptidase (IRAP) is a membrane aminopeptidase and is homologous to the placental leucine aminopeptidase, P-LAP. IRAP has a wide distribution but has been best characterized in adipocytes and myocytes. In these cells, IRAP colocalizes with the glucose transporter GLUT4 to intracellular vesicles and, like GLUT4, translocates from these vesicles to the cell surface in response to insulin. Earlier studies demonstrated that purified IRAP cleaves several peptide hormones and that, concomitant with the appearance of IRAP at the surface of insulin-stimulated adipocytes, aminopeptidase activity toward extracellular substrates increases. In the present study, to identify in vivo substrates for IRAP, we tested potential substrates for cleavage by IRAP-deficient (IRAP−/−) and control mice. We found that vasopressin and oxytocin were not processed from the NH2terminus by isolated IRAP−/−adipocytes and skeletal muscles. Vasopressin was not cleaved from the NH2terminus after injection into IRAP−/−mice and exhibited a threefold increased half-life in the circulation of IRAP−/−mice. Consistent with this finding, endogenous plasma vasopressin levels were elevated twofold in IRAP−/−mice, and vasopressin levels in IRAP−/−brains, where plasma vasopressin originates, showed a compensatory decrease. We further established that insulin increased the clearance of vasopressin from control but not from IRAP−/−mice. In conclusion, we have identified vasopressin as the first physiological substrate for IRAP. Changes in plasma and brain vasopressin levels in IRAP−/−mice suggest a significant role for IRAP in regulating vasopressin. We have also uncovered a novel IRAP-dependent insulin effect: to acutely modify vasopressin.
Effects of fasting on insulin action and glucose kinetics in lean and obese men and women
Authors: Bergman Bryan C. , Cornier Marc-Andre , Horton Tracy J. , Bessesen Daniel H.
Published: August 2007

The development of insulin resistance in the obese individual could impair the ability to appropriately adjust metabolism to perturbations in energy balance. We investigated a 12- vs. 48-h fast on hepatic glucose production (Ra), peripheral glucose uptake (Rd), and skeletal muscle insulin signaling in lean and obese subjects. Healthy lean [ n = 14; age = 28.0 ± 1.4 yr; body mass index (BMI) = 22.8 ± 0.42] and nondiabetic obese ( n = 11; age = 34.6 ± 2.3 yr; BMI = 36.1 ± 1.5) subjects were studied following a 12- and 48-h fast during 2 h of rest and a 3-h 40 mU·m−2·min−1hyperinsulinemic-euglycemic clamp (HEC). Basal glucose Radecreased significantly from the 12- to 48-h fast (lean 1.96 ± 0.23 to 1.63 ± 0.15; obese 1.23 ± 0.07 to 1.07 ± 0.07 mg·kg−1·min−1; P = 0.004) and was equally suppressed during the HEC after both fasts. The increase in glucose Rdduring the HEC after the 12-h fast was significantly decreased in lean and obese subjects after the 48-h fast (lean 9.03 ± 1.17 to 4.16 ± 0.34, obese 6.10 ± 0.77 to 3.56 ± 0.30 mg·kg FFM−1·min−1; P < 0.001). After the 12- but not the 48-h fast, insulin-stimulated AKT Ser473phosphorylation was greater in lean than obese subjects. We conclude that 1) 48 h of fasting produces a marked decline in peripheral insulin action, while suppression of hepatic glucose production is maintained in lean and obese men and women; and 2) the magnitude of this decline is greater in lean vs. obese subjects.
GSK-3β activity is increased in skeletal muscle after burn injury in rats
Authors: Fang Cheng-Hui , Li Bingguo , James J. Howard , Yahya Ayesha , Kadeer Nijiati , Guo Xialing , Xiao Chun , Supp Dorothy M. , Kagan Richard J. , Hasselgren Per-Olof , Sheriff Sulaiman
Published: August 2007

Previous reports suggest that burn-induced muscle proteolysis can be inhibited by treatment with GSK-3β inhibitors, suggesting that burn injury may be associated with increased GSK-3β activity. The influence of burn injury on muscle GSK-3β activity, however, is not known. We determined the effect of a 30% total body surface full-thickness burn injury in rats on muscle GSK-3β activity by measuring GSK-3β activity and tissue levels of serine 9 phosphorylated GSK-3β, p(Ser9)-GSK-3β, by Western blot analysis and immunohistochemistry. Because burn-induced muscle wasting is, at least in part, mediated by glucocorticoids, we used dexamethasone-treated cultured muscle cells in which GSK-3β expression was reduced with small interfering RNA (siRNA) to further assess the role of GSK-3β in muscle atrophy. Burn injury resulted in a seven-fold increase in GSK-3β activity in skeletal muscle. This effect of burn was accompanied by reduced tissue levels of p(Ser9)-GSK-3β, suggesting that burn injury stimulates GSK-3β in skeletal muscle secondary to inhibited phosphorylation of the enzyme. In addition, burn injury resulted in inhibited phosphorylation and activation of Akt, an upstream regulatory mechanism of GSK-3β activity. Reducing the expression of GSK-3β in cultured muscle cells with siRNA inhibited dexamethasone-induced protein degradation by ∼50%. The results suggest that burn injury stimulates GSK-3β activity in skeletal muscle and that GSK-3β may, at least in part, regulate glucocorticoid-mediated muscle wasting.
Increasing length of wakefulness and modulation of hypocretin-1 in the wake-consolidated squirrel monkey
Authors: Zeitzer Jamie M. , Buckmaster Christine L. , Lyons David M. , Mignot Emmanuel
Published: August 2007

The neuropeptides hypocretins (orexins), the loss of which results in the sleep disorder narcolepsy, are hypothesized to be involved in the consolidation of wakefulness and have been proposed to be part of the circadian-driven alertness signal. To elucidate the role of hypocretins in the consolidation of human wakefulness we examined the effect of wake extension on hypocretin-1 in squirrel monkeys, primates that consolidate wakefulness during the daytime as do humans. Wake was extended up to 7 h with hypocretin-1, cortisol, ghrelin, leptin, locomotion, and feeding, all being assayed. Hypocretin-1 ( P < 0.01), cortisol ( P < 0.001), and locomotion ( P < 0.005) all increased with sleep deprivation, while ghrelin ( P = 0.79) and leptin ( P = 1.00) did not change with sleep deprivation. Using cross-correlation and multivariate modeling of these potential covariates along with homeostatic pressure (a measure of time awake/asleep), we found that time of day and homeostatic pressure together explained 44% of the variance in the hypocretin-1 data ( P < 0.001), while cortisol did not significantly contribute to the overall hypocretin-1 variance. Locomotion during the daytime, but not during the nighttime, helped explain < 5% of the hypocretin-1 variance ( P < 0.05). These data are consistent with earlier evidence indicating that in the squirrel monkey hypocretin-1 is mainly regulated by circadian inputs and homeostatic sleep pressure. Concomitants of wakefulness that affect hypocretin-1 in polyphasic species, such as locomotion, food intake, and food deprivation, likely have a more minor role in monophasic species, such as humans.
PGE2 inhibits apical K channels in the CCD through activation of the MAPK pathway
Authors: Jin Yan , Wang Zhijian , Zhang Yan , Yang Baofeng , Wang Wen-Hui
Published: August 2007

We used the patch-clamp technique and Western blot analysis to explore the effect of PGE2 on ROMK-like small-conductance K (SK) channels and Ca2+-activated big-conductance K channels (BK) in the cortical collecting duct (CCD). Application of 10 μM PGE2 inhibited SK and BK channels in the CCD. Moreover, either inhibition of PKC or blocking mitogen-activated protein kinase (MAPK), P38 and ERK, abolished the effect of PGE2 on SK channels in the CCD. The effect of PGE2 on SK channels was completely blocked in the presence of SC-51089, a specific EP1 receptor antagonist, and mimicked by application of sulprostone, an agonist for EP1 and EP3 receptors. To determine whether PGE2 stimulates the phosphorylation of P38 and ERK, we treated mouse CCD cells (M-1) with PGE2. Application of PGE2 significantly stimulated the phosphorylation of P38 and ERK within 5 min. The dose-response curve of PGE2 effect shows that 1, 5, and 10 μM PGE2 increased the phosphorylation of P38 and ERK by 20–21, 50–80, and 80–100%, respectively. The stimulatory effect of PGE2 on MAPK phosphorylation was not affected by indomethacin but abolished by inhibition of PKC. This suggests that the effect of PGE2 on MAPK phosphorylation is PKC dependent. Also, the expression of cyclooxygenase II and PGE2 concentration in renal cortex and outer medulla was significantly higher in rats fed a K-deficient diet than those on a normal-K diet. We conclude that PGE2 inhibits SK and BK channels and that there is an effect of PGE2 on SK channels in the CCD through activation of EP1 receptor and MAPK pathways. Also, high concentrations of PGE2 induced by K restriction may be partially responsible for increasing MAPK activity during K restriction.
Response Facilitation From the “Suppressive” Receptive Field Surround of Macaque V1 Neurons
Authors: Ichida Jennifer M. , Schwabe Lars , Bressloff Paul C. , Angelucci Alessandra
Published: August 2007

In primary visual cortex (V1), neuronal responses to optimally oriented stimuli in the receptive field (RF) center are usually suppressed by iso-oriented stimuli in the RF surround. The mechanisms and pathways giving rise to surround modulation, a possible neural correlate of perceptual figure-ground segregation, are not yet identified. We previously proposed that highly divergent and fast-conducting top-down feedback connections are the substrate for fast modulation arising from the more distant regions of the surround. We have recently implemented this idea into a recurrent network model ( Schwabe et al. 2006 ). The purpose of this study was to test a crucial prediction of this feedback model, namely that the suppressive “far” surround of V1 neurons can be facilitatory under conditions that weakly activate neurons in the RF center. Using single-unit recordings in macaque V1, we found iso-orientation far-surround facilitation when the RF center was driven by a low-contrast stimulus and the far surround by a small annular stimulus. Suppression occurred when the center stimulus contrast or the size of the surround stimulus was increased. This suggests that center-surround interactions result from excitatory and inhibitory mechanisms of similar spatial extent, and that changes in the balance of local excitation and inhibition, induced by surround stimulation, determine whether facilitation or suppression occurs. In layer 4C, the main target of geniculocortical afferents, lacking long-range intra-cortical connections, far-surround facilitation was rare and large surround fields were absent. This strongly suggests that feedforward connections do not contribute to far-surround modulation and that the latter is generated by intra-cortical mechanisms, likely involving top-down feedback.
Proliferative Activity, Apoptosis, and Histogenesis in the Early Stages of Rat Tooth Extraction Wound Healing
Authors: Sato Hirotaka , Takeda Yasunori
Published: August 2007

We examined the proliferative activity, apoptosis, and histogenesis in the early stages of the rat healing socket from just after extraction until new bone formation occurs. Thirty 11-week-old male Wistar rats underwent bilateral maxillary first molar tooth extraction. Five craniomaxillary tissue specimens were dissected at the following time points: at 12 h, days 1, 3, 5, 7 and 10 after surgery. The immunohistochemical expression of both proliferating cell nuclear antigen (PCNA) and the Ki67 counterpart of rodent (MIB5) for proliferative activity and both the TUNEL reaction and the immunohistochemical expression of single-strand DNA for apoptosis were evaluated using 6-µm-thick serial paraffin sections, which were prepared in the coronal plane. The positive cell counts in the socket were converted into the cell numbers per mm2 as either the proliferative index (PI) or the apoptotic index (AI). The PI and the AI showed maximum levels at 5 days and 12 h after extraction, respectively. The proliferative activity in the early stages of extraction wound healing is initially distributed in the remaining periodontium with load-induced apoptosis, next in the proliferative fibrous tissue, and then around the trabeculae of the new bone marking its peak.
Experimental Koebner Phenomenon in Patients with Psoriasis
Authors: Kalayciyan Aylin , Aydemir Ertugrul H. , Kotogyan Agop
Published: August 2007

Background: The Koebner phenomenon is defined as ‘the development of psoriasis at sites of traumatized skin’. The ‘all-or-none principle’ means that, if psoriasis occurs in one area of injury, all injured areas develop psoriasis or vice versa. The aim is to demonstrate the concordance of patients with the all-or-none principle when a standard method of trauma is employed. Methods: Sixty-two patients with psoriasis were enrolled in the study. Demographic data and disease characteristics were recorded. The medial aspects of both forearms, devoid of lesions, were pricked using two sets of five 30-gauge needles at an angle of 30°, with 2-cm intervals. On days 14 and 28, the patients’ forearms were checked for the presence of a typical psoriatic plaque of white scales on an erythematous papule. Results: On day 28, 45 patients (72.5%) had a negative Koebner response in all prick sites whereas 1 patient (1.6%) had psoriatic papules in 10 out of 10 prick sites. The rest of the patients (n = 16, 25.8%) had between 1 and 9 papules in number. Conclusion: Using standard methods of trauma, it is possible to induce psoriasis lesions as a Koebner response but this response is not always in concordance with the all-or-none principle previously described.
Epidemiology and Comorbidity of Erysipelas in Primary Care
Authors: Bartholomeeusen Stefaan , Vandenbroucke Jan , Truyers Carla , Buntinx Frank
Published: August 2007

Background/Aims: Most studies on the epidemiology of erysipelas are done in hospitals, resulting in patient selection. The aim of this study is to determine epidemiological characteristics and comorbidity of erysipelas based on primary care data. Methods: Incidence rate study and nested case-control study. A database containing data from 52 general practices in Flanders, Belgium, with morbidity data on 160,000 different patients in the period 1994–2004. Excess comorbidity was determined in patients with erysipelas in 2004. Results: In the period 1994–2004, the age-standardized incidence of erysipelas increased significantly from 1.88 (95% confidence interval, CI, 1.62–2.13) per 1,000 patients to 2.49 (95% CI 2.24–2.74). Of patients with erysipelas, 16% had one or more recurrences. Local factors such as dermatophytosis, chronic ulcer of the skin, varicose veins of the leg and phlebitis and general disorders such as obesity, non-insulin-dependent diabetes and heart failure increased the risk of erysipelas. Conclusion: The incidence of erysipelas increased from 1994 to 2004. More attention should be paid to local factors such as dermatophytosis to prevent erysipelas.
Atopic Dermatitis: Impact on the Quality of Life of Patients and Their Partners
Authors: Misery L. , Finlay A.Y. , Martin N. , Boussetta S. , Nguyen C. , Myon E. , Taieb C.
Published: August 2007

Background: The impact of atopic dermatitis (AD) on the patient’s quality of life is relatively well known. However, the influence on the patient’s spouse has never been studied. Objective: To evaluate the impact of AD on the quality of life, sleeping and sexual life of patients and their partners. Methods: In this cross-sectional study, patients and their partners completed a number of questionnaires asking about their general health and their quality of life [Short Form 12, Epworth, Dermatology Life Quality Index (DLQI)] and completed an idiosyncratic measure asking about their sexual functioning. AD severity was clinician rated using Scoring atopic dermatitis (SCORAD). Results: A total of 266 patients were included. The mean DLQI score was 8.8. The physical and mental composite 12 scores were 50.7 and 39.5, respectively. These 3 scores were significantly related to SCORAD. A decrease in sexual desire due to AD was noted in 57.5% of patients. The quality of life of partners did not appear to be particularly impaired, but 36.5% reported that the appearance of eczema had an impact on their sex life. Conclusion: The influence of AD on sex life is significant both for the patients and their partners.
5% Topical Imiquimod Tolerance in Transplant Recipients
Authors: Ben M’barek Lilia , Mebazaa Amel , Euvrard Sylvie , Frances Camille , Thervet Eric , Morel Patrice , Menasché Suzanne , Legendre Christophe , Lebbe Celeste
Published: August 2007

Background: Topical imiquimod is a new immunomodulator agent approved for genital warts, actinic keratosis (AK) or carcinoma, occurring in immunocompetent patients. Objectives: This study aimed to assess the safety and efficacy of imiquimod for the treatment of warts, AK and bowenoid papulosis (BP) in transplant patients. Methods: 24 transplant patients (18 kidney, 4 kidney-pancreas and 2 heart) were included in this retrospective study conducted between June 2000 and February 2003 at the department of dermatology of 3 hospitals. Imiquimod cream was applied 3 times a week over a median period of 9 weeks. Results: Graft function was not altered under therapy. Local tolerance was excellent. Complete responses were observed in 1 patient (1/12) with cutaneous warts and 1 (1/6) with AK. Two patients of 3 with BP had total clearance of their lesions. Partial responses were observed in 3 of the 6 AK-treated patients, 5 of 12 patients with cutaneous warts and 1 of 2 patients with anogenital warts. Conclusions: Imiquimod 5% cream is a promising, well-tolerated therapy for warts, AK and BP in transplant recipients.
Unwanted Facial Hair: Affects, Effects and Solutions
Authors: Blume-Peytavi U. , Gieler U. , Hoffmann R. , Lavery S. , Shapiro J.
Published: August 2007

The following is a review of a satellite symposium held at the EHRS Meeting in June 2006. U.B.P. reminded the audience that unwanted facial hair (UFH) is an important issue; over 40% of the women in the general population have some degree of UFH, and its psychological and psychosocial impact should not be underestimated. The treatment of UFH involves many different disciplines, and the symposium offered the latest thinking in different aspects of the disorder. S.L. outlined the current concepts surrounding polycystic ovarian syndrome, and U.G. addressed the psychological aspects of UFH. J.S. described the current treatment options for UFH, followed by U.B.P.’s evidence-based therapy review. Finally, R.H. reviewed the latest trial results with Trichoscan, a method being investigated for assessing UFH removal.
Extraneural Arterial Blood Vessels of Human Fetal Sciatic Nerve
Authors: Ugrenovic Slađana Z. , Jovanovic Ivan D. , Vasović Ljiljana P. , Stefanović Bratislav D.
Published: August 2007

Nerves get segmental blood supply either from the neighboring muscular and cutaneous branches or from the regional main arterial trunks. The aim of our research was to detect, in the gluteal and posterior femoral region, the blood vessels which are involved in the blood supply of the human fetal sciatic nerve, as well as to establish their origin. Micro-dissection was performed on 48 fetal lower extremities which were previously fixed in 10% formalin. Micropaque solution (barium sulfate) was injected into their blood vessels. The fetal gestational age was established by measuring the crump-crown length and it ranged from the third to the ninth lunar month. The observed nutritional arteries of the human sciatic nerve originated from the inferior gluteal artery, medial circumflex femoral artery, perforating branches, and popliteal artery. The anastomotic arterial chain of the human sciatic nerve was observed in all cases. In 75% of the cases it was composed of the branches of the inferior gluteal artery, the medial circumflex femoral artery and the first two perforating arteries. The nutrient branch of the third perforating branch was less frequently (in 14.5% of the cases) part of this anastomotic arterial chain.
Altered Transcription Profiles of Key-Enzymes of Androgen Biosynthesis in Genital Skin Fibroblasts from Patients with 46,XY Disorders of Sex Development (DSD)
Authors: Hoppe U. , Wünsch L. , Holterhus P.-M. , Jocham D. , Richter-Unruh A. , Hiort O.
Published: August 2007

Normal synthesis and action of androgens is essential for normal male sex differentiation. 17β-hydroxysteroid dehydrogenase (17β-HSD) and 5α-reductase isoenzymes play essential roles in normal androgen biosynthesis. We hypothesized that differences in expression of these enzymes in genital skin could contribute to the pathogenesis of 46,XY disorders of sex development (DSD). We investigated the mRNA transcription patterns of 17β-hydroxysteroid dehydrogenase-isoenzymes type 1, 2, 3, 4, 5, 7, and 10, 5α-reductase type 1 and 2 and the androgen receptor in genital skin fibroblasts from foreskin and scrotal skin obtained from healthy males and patients with unclassified 46,XY DSD. mRNA expression was semi-quantified by real-time PCR. Although no systematic differences of gene expression of any enzyme between normal controls and hypospadias patients could be detected, we found in nearly half of all investigated patients’ samples noticeable differences in the transcription profiles of 17β-hydroxysteroid dehydrogenase type 5. In scrotal skin samples of patients a significantly higher transcription of the androgen receptor was detected. A role for an altered expression pattern of different enzymes of steroidogenesis in the etiology of genital malformations in some patients may be postulated.
Hemosuccus Pancreaticus in the Era of Capsule Endoscopy and Double Balloon Enteroscopy Complicated by Multifocal Mycobacterium chelonae/abscessus Infection
Authors: Pasha Shabana F. , Blair Janis E. , Garvey Patrick B. , Gray Richard J. , Mulligan David C. , Collins Joseph M. , Heigh Russell I.
Published: August 2007

Hemosuccus pancreaticus is a rare etiology of obscure gastrointestinal bleeding characterized by bleeding into the pancreatic duct. The diagnosis may be delayed for months to years, due to the episodic nature of bleeding and failure to consider the diagnosis. Patients often undergo multiple endoscopies and radiologic evaluations prior to diagnosis. Incidental gastrointestinal findings may lead to unnecessary endoscopic and surgical interventions. This report describes a patient with hemosuccus pancreaticus diagnosed in the era of video capsule endoscopy and double balloon enteroscopy, whose management was complicated by multifocal Mycobacteria chelonae/abscessus infection.
Geranylgeranylacetone Protects the Human Gastric Mucosa from Diclofenac-Induced Injury via Induction of Heat Shock Protein 70
Authors: Yanaka Akinori , Zhang Songhua , Sato Daisuke , Tauchi Masafumi , Suzuki Hideo , Shibahara Takeshi , Matsui Hirofumi , Nakahara Akira , Hyodo Ichinosuke
Published: August 2007

Background/Aim: Geranylgeranylacetone (GGA) enhances gastric mucosal protection against nonsteroidal anti-inflammatory drugs by upregulating mucosal heat shock proteins (HSP), but the effects of GGA on the human gastric mucosa have not been well examined. This study was conducted to determine whether a clinical dose of GGA protects the human gastric mucosa from diclofenac (DIC)-induced gastric mucosal injury. Methods: The study group comprised 40 healthy volunteers: 20 subjects were randomly assigned to take either placebo (lactose 1.5 g/day) or GGA (150 mg/day) for 2 weeks (study 1), and 20 subjects were assigned to take DIC (75 mg/day) plus placebo (lactose 1.5 g/day) or DIC (75 mg/day) plus GGA (150 mg/day) for 2 weeks (study 2). In both studies, gastroscopic biopsy specimens were obtained before and after treatment. Mucosal HSP70 expression and DNA damage were analyzed by measuring the levels of HSP70 and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-OHdG), respectively. Results: In study 1, GGA increased the mucosal HSP70 expression without increasing the 8-OHdG production. In study 2, DIC treatment increased the 8-OHdG production, whereas the combination of GGA and DIC enhanced the HSP70 expression and attenuated the increase in 8-OHdG induced by DIC. Conclusion: The clinical dose of GGA enhanced the gastric mucosal HSP70 expression and inhibited the DIC-induced gastric mucosal damage in humans.
Pancreatic Duct Stents in the Prophylaxis of Pancreatic Damage after Endoscopic Retrograde Cholangiopancreatography: A Systematic Analysis of Benefits and Associated Risks
Authors: Andriulli Angelo , Forlano Rosario , Napolitano Grazia , Conoscitore Pasquale , Caruso Nazario , Pilotto Alberto , Di Sebastiano Pier Luigi , Leandro Gioacchino
Published: August 2007

Methods: The efficacy of pancreatic stenting in the prevention of pancreatitis following endoscopic retrograde cholangiopancreatography (ERCP) was evaluated by a meta-analysis of 6 controlled studies; 12 additional uncontrolled studies were analyzed for rates of associated risk. Results: Post-ERCP pancreatitis (PEP) developed in 16.5% of controls, and in 5.1 or 9.6% of the stent group at the per-protocol (PP) or intention-to-treat (ITT) analyses. By analyzing only the 4 randomized trials, PEP developed in 24.1% of controls, and in 6.1 or 12.0% of the stented patients at the PP or ITT analyses. Risk was significantly lower in the stent group when compared with controls: OR 0.44 (95% CI 0.24–0.81). The absolute risk reduction is 12.0 (95% CI 3.0–21.0), the number needed to treat 8 (95% CI 5–34), and the publication bias 2. ORs for mild to moderate PEP were reduced in the stent group (OR = 0.537, 95% CI 0.283–1.021), as were those for severe PEP (OR = 0.123, 95% CI 0.021–0.726). Non-pancreatic complications were 4.2%, and included early stent migration (1.4%), perforations (0.4%), bleeding (1.4%), and infections (1.0%). Conclusion: Available trials show benefit for pancreatic stenting in the prophylaxis of PEP, but more randomized studies are needed before endorsing a routine use of this endoscopic procedure.
Hormone Replacement Therapy after Treatment of Endometrial Cancer
Authors: Tangjitgamol Siriwan , Manusirivithaya Sumonmal , Hanprasertpong Jitti , Kavanagh John J.
Published: August 2007

Hormone replacement therapy (HRT) after endometrial cancer (EMC) treatment is an uncertain subject with limited exploration among gynecologic cancer research. Because estrogen is a well-recognized etiologic factor of EMC, most physicians are probably reluctant to provide a replacement therapy, or limit its use to only a selected group of patients. In order to give an overview on this subject, we searched the English-language literature to identify relevant studies or reports. We found that HRT did not appear to increase the recurrence or death rates in EMC. However, most information came from retrospective studies with selection bias, or from a small prospective non-randomized study. The only randomized controlled trial of the Gynecologic Oncology Group could also not provide a definite answer regarding its safety and recommendation. In conclusion, on the basis of the currently available studies, HRT after EMC treatment does not appear to have an adverse effect on EMC. Nevertheless, because of a limitation of data, the physician should thoroughly consider all possible benefits and theoretical risks of recurrence or mortality in each individual to provide the best of care for their patients.