bluuebunny/crossref_metadata_2025 huggingface dataset:
Cellular Distribution of the GABAA Receptor‐Modulating 3α‐Hydroxy, 5α‐Reduced Pregnane Steroids in the Adult Rat Brain
Authors: Saalmann Y. B. , Kirkcaldie M. T. K. , Waldron S. , Calford M. B.
Published: January 2007

The 3α‐hydroxy,5α‐reduced pregnane steroids, allopregnanolone and allotetrahydrodeoxycorticosterone, are the most potent endogenous positive modulators of GABAA receptor‐mediated inhibition. This study presents the first immunohistochemical examination of the cellular distribution of 3α‐hydroxy,5α‐reduced pregnane steroids across the brain. We found a widespread distribution in the adult rat, with dense immunolabelling in the olfactory bulb, striatum and cerebral cortex, and lower density labelling in the brainstem reticular formation. In general terms, this distribution accords with the regional concentrations of 3α‐hydroxy,5α‐reduced steroids determined, in other laboratories, by brain region sampling and either gas chromatography‐mass fragmentography or radioimmunoassay. However, immunohistochemistry allowed for a more detailed examination of regional distribution and cellular specificity. All immunoreactivity was confined to the cell bodies and thick dendrites of neurones; no identifiable glia were labelled. In most brain areas, the location and morphology of labelled cells identified them as excitatory neurones. In addition, cell populations known to be projecting GABAergic neurones (e.g. cerebellar Purkinje cells) were immunoreactive, whereas local inhibitory neurones generally were not. The cellular distribution of 3α‐hydroxy,5α‐reduced steroids suggests that sensory, motor, limbic and homeostatic systems can be influenced by neurosteroids at multiple stages of processing.
Social parasitism by workers in queenless and queenrightApis ceranacolonies
Authors: NANORK P. , CHAPMAN N. C. , WONGSIRI S. , LIM J. , GLOAG R. S. , OLDROYD B. P.
Published: January 2007

We examined worker reproduction in queenless and queenrightApis ceranacolonies to determine if they are parasitized by workers from other nests. The results demonstrate that 2–6% of workers in queenright colonies are from another nest (non‐natal), but these workers are not statistically more likely to have activated ovaries than natal workers, and are therefore unlikely to be active parasites. However, in queenless colonies we found a significant difference between the proportion of non‐natal (72.7%) and natal (36.3%) workers with activated ovaries. Non‐natal workers also had significantly higher reproductive success than natal workers: 1.8% of workers were non‐natal, but these laid 5.2% of the eggs and produced 5.5% of the pupae. UnlikeA. florea, the proportion of non‐natal workers does not increase in queenless nests.
Genetic structure of the widespread and common Mediterranean bryophyte Pleurochaete squarrosa (Brid.) Lindb. (Pottiaceae) — evidence from nuclear and plastidic DNA sequence variation and allozymes
Authors: GRUNDMANN MICHAEL , ANSELL STEPHEN W. , RUSSELL STEPHEN J. , KOCH MARCUS A. , VOGEL JOHANNES C.
Published: January 2007

The Mediterranean Basin as one the world's most biologically diverse regions provides an interesting area for the study of plant evolution and spatial structure in plant populations. The dioecious moss Pleurochaete squarrosa is a widespread and common bryophyte in the Mediterranean Basin. Thirty populations were sampled for a study on molecular diversity and genetic structure, covering most major islands and mainland populations from Europe and Africa. A significant decline in nuclear and chloroplast sequence and allozyme variation within populations from west to east was observed. While DNA sequence data showed patterns of isolation by distance, allozyme markers did not. Instead, their considerable interpopulation genetic differentiation appeared to be unrelated to geographic distance. Similar high values for coefficients of gene diversity (GST) in all data sets provided evidence of geographic isolation and limited gene flow among populations (i) within islands, (ii) within mainland areas, and (iii) between islands and mainland. Notably, populations in continental Spain are strongly genetically isolated from all other investigated areas. Surprisingly, there was no difference in gene diversity and GST between islands and mainland areas. Thus, we conclude that large Mediterranean islands may function as ‘mainland’ for bryophytes. This hypothesis and its implication for conservation biology of cryptogamic plants warrant further investigation. While sexually reproducing populations were found all over the Mediterranean Basin, high levels of multilocus linkage disequilibrium provide evidence of mainly vegetative propagation even in populations where sexual reproduction was observed.
Working at the interface of phylogenetics and population genetics: a biogeographical analysis of Triaenops spp. (Chiroptera: Hipposideridae)
Authors: RUSSELL A. L. , RANIVO J. , PALKOVACS E. P. , GOODMAN S. M. , YODER A. D.
Published: January 2007

New applications of genetic data to questions of historical biogeography have revolutionized our understanding of how organisms have come to occupy their present distributions. Phylogenetic methods in combination with divergence time estimation can reveal biogeographical centres of origin, differentiate between hypotheses of vicariance and dispersal, and reveal the directionality of dispersal events. Despite their power, however, phylogenetic methods can sometimes yield patterns that are compatible with multiple, equally well‐supported biogeographical hypotheses. In such cases, additional approaches must be integrated to differentiate among conflicting dispersal hypotheses. Here, we use a synthetic approach that draws upon the analytical strengths of coalescent and population genetic methods to augment phylogenetic analyses in order to assess the biogeographical history of Madagascar's Triaenops bats (Chiroptera: Hipposideridae). Phylogenetic analyses of mitochondrial DNA sequence data for Malagasy and east African Triaenops reveal a pattern that equally supports two competing hypotheses. While the phylogeny cannot determine whether Africa or Madagascar was the centre of origin for the species investigated, it serves as the essential backbone for the application of coalescent and population genetic methods. From the application of these methods, we conclude that a hypothesis of two independent but unidirectional dispersal events from Africa to Madagascar is best supported by the data.
Unusual behaviour of epikarst in the Acqua dei Faggi carbonate aquifer (Southern Italy)
Authors: Petrella Emma , Capuano Paolo , Celico Fulvio
Published: January 2007

Hydrogeological and geophysical investigations demonstrated the existence of an epikarstic zone in a carbonate aquifer of Southern Italy, about 10 m thick. Nevertheless, the hydrogeological behaviour of the epikarst is different from that schematized by several authors. In the test site, the contrast in permeability at the bottom of the epikarst does not cause retention of percolation and storage of water in a perched temporary aquifer within the uppermost portion of the carbonate medium. Because of the high fracture density and good interconnection of openings within the underlying limestone, the percolation is diffuse also below the epikarstic zone, as well as the groundwater flow. The ‘funnelling’ effect into larger shafts does not play an important role on the hydrogeological behaviour of the aquifer.
Diachronous exhumation of HP–LT metamorphic rocks from south‐western Alps: evidence from fission‐track analysis
Authors: Schwartz S. , Lardeaux J. M. , Tricart P. , Guillot S. , Labrin E.
Published: January 2007

New fission‐track ages on zircon and apatite (ZFT and AFT) from the south‐western internal Alps document a diachronous cooling history from east to west, with cooling rates of 15–19 °C Ma−1. In the Monviso unit, the ZFT ages are 19.6 Ma and the AFT ages are 8.6 Ma. In the eastern Queyras, ZFT ages range from 27.0 to 21.7 Ma and AFT ages from 14.2 to 9.4 Ma. In the western Queyras, ZFT ages are between 94.7 and 63.1 Ma and AFT ages are between 22.2 and 22.6 Ma. The Chenaillet ophiolite yields ages of 118.1 Ma on ZFT and 67.9 Ma on AFT. The combination of these new FT data with the available petrological and geochronological data emphasize an earlier exhumation in subduction context before 30 Ma, then in collision associated with westward tilting of the Piedmont zone.
Microbial content of drinking water in Finnish and Russian Karelia – implications for atopy prevalence
Authors: Von Hertzen L. , Laatikainen T. , Pitkänen T. , Vlasoff T. , Mäkelä M. J. , Vartiainen E. , Haahtela T.
Published: January 2007

Background and aim:  The influence of microbial quality of drinking water from different sources on the occurrence of atopy has been poorly examined. This study was undertaken to clarify the association between the overall microbial content in drinking water and the occurrence of atopy among schoolchildren from two neighbouring areas with profound differences in living conditions and lifestyles.

Methods:  Drinking water samples were obtained from kitchens of nine schools in North Karelia, Finland and of nine schools from Pitkäranta, the Republic of Karelia, Russia. The pupils of these schools were participants of the Karelian Allergy Study. Occurrence of atopy, determined by skin prick test positivity (one or more) to 14 common airborne and food allergens, was measured in all 563 children, aged 7–16 years, from these 18 schools. Water samples were analysed using standard methods for drinking water analyses including viable counts for Escherichia coli, intestinal enterococci, coliform bacteria and heterotrophic bacteria. In addition, total cell counts including both viable and nonviable bacteria, algae and protozoans were assessed using epifluorescence microscope with 4′‐6‐diamidino‐2‐phenylindole (DAPI) staining.

Results:  In Finland, 29% of the children were sensitized to birch when compared with 2% of the Russian children (P < 0.0001). Overall, sensitization rates for any of the pollens were 39% and 8% (P < 0.0001), and for any of the allergens 48% and 16%, respectively (P < 0.0001). Because of substantial differences in raw water sources and treatment practices, the total numbers of microbial cells in drinking water were many‐fold higher in Russia than in Finland. A dose–response relationship was found for occurrence of atopy and the DAPI value indicative of microbial cell content in the water (P < 0.0001). Further, multivariate logistic regression analysis revealed that high (>106 cells/ml) and intermediate (105–106 cells/ml) DAPI values were associated with reduced risk of atopy (odds ratio 0.34, 95% confidence interval 0.20–0.57 and 0.39, 0.23–0.69, respectively), independently from other factors.

Conclusion:  High overall content of micro‐organisms in drinking water may be associated with reduced risk of atopy, independently from other determinants.
Significant association between TNF‐α (TNF) promoter allele (−1031C, −863C, and −857C) and cerebral malaria in Thailand
Authors: Hananantachai H. , Patarapotikul J. , Ohashi J. , Naka I. , Krudsood S. , Looareesuwan S. , Tokunaga K.
Published: January 2007

We examined a possible association of three single nucleotide polymorphisms (SNPs) of the tumor necrosis factor alpha (TNF) promoter −1031T>C (rs1799964), −863C>A (rs1800630), and −857C>T (rs1799724) with severe malaria in 466 adult patients havingPlasmodium falciparummalaria in northwest Thailand. FourTNFpromoter alleles comprising these three SNPs were detected in the studied population. The frequency of theTNF U04allele designated −1031C, −863C, and −857C was found to be significantly greater in patients with cerebral malaria than in patients with mild malaria (12.6%, cerebral malariavs5.6%, mild malaria; odds ratio = 2.5;P= 0.002). The association ofU04with susceptibility to cerebral malaria was not caused by linkage disequilibrium with any specificHLA‐Band‐DRB1alleles.
Retracted: Do patients profit from physostigmine in recovery from desflurane anaesthesia?
Authors: Röhm K. D. , Riechmann J. , Boldt J. , Schöllhorn T. , Piper S. N.
Published: January 2007

Background:  Physostigmine is the drug of choice in the central anticholinergic syndrome, but has also been used in post‐operative mental derangement secondary to sedatives and volatile anaesthetics. The aim of this double‐blind, randomized, prospective study was to determine whether physostigmine alters recovery after desflurane anaesthesia.

Methods:  One hundred patients undergoing urologic or surgical procedures were enrolled to receive either NaCl 0.9% (n= 50) or 2 mg of physostigmine (n= 50) at the end of general anaesthesia with propofol, fentanyl, cisatracurium and desflurane. Times to extubation, stating name, birthday and place of residence, and obeying commands such as eye opening and hand squeezing were noted. Haemodynamics, Aldrete and pain scores, the analgesic requirements, and any adverse side‐effects were documented until the 1st post‐operative day.

Results:  Demographic, peri‐operative data including duration of anaesthesia, surgery and postanaesthetic care unit (PACU) stay, and consumption of anaesthetics were comparable in both groups. No significant difference between the groups was found for extubation time or other emergence parameters. Patients undergoing anaesthesia >150 min showed after receiving physostigmine significantly (P < 0.05) faster spontaneous breathing (2.6 ± 3.1 vs. placebo 5.0 ± 4.2 min) and extubation time (6.2 ± 3.7 vs. placebo 8.8 ± 5.0 min). Women showed significantly shorter extubation times (5.5 ± 3.4 min) and eye opening (5.5 ± 2.6 min) with physostigmine than placebo (7.7 ± 4.5 and 7.8 ± 4.0 min). The incidence of post‐operative nausea and vomiting (PONV) was significantly higher after physostigmine than placebo, whereas shivering occurred more often after placebo.

Conclusion:  Physostigmine does not alter desflurane‐based anaesthesia compared with placebo. An option is to use physostigmine in patients with a duration of anaesthesia >150 min who profit in earlier return to spontaneous breathing and shorter extubation time.
In Vitro and In Vivo Temporal Aspects of ACTH Secretion: Stimulatory Actions of Corticotropin‐Releasing Hormone and Vasopressin in Cattle
Authors: Carroll J. A. , McArthur N. H. , Welsh T. H.
Published: January 2007

The objective of the present study was to evaluate the temporal aspects associated with corticotropin‐releasing hormone (CRH) and vasopressin (VP) stimulated bovine adrenocorticotropic hormone (ACTH) secretion in vitro and in vivo. For the in vitro studies, bovine anterior pituitary glands were enzymatically dispersed to establish primary cultures. On day 5 of culture, cells were challenged for 3 h with medium alone (Control) or various combinations and concentrations of bovine CRH (bCRH) and VP. Both CRH and VP each increased (P < 0.05) ACTH secretion. Maximal increases in ACTH secretion occurred in response to 0.1 μm CRH (5.5‐fold) and 1 μm VP (3.7‐fold), relative to Control cells. The in vivo portion of the study examined possible temporal differences in the activation of the pituitary‐adrenal axis by CRH and VP. Jersey cows were randomly assigned to one of four groups (n = 8 cows/group): (i) Control (saline); (ii) bCRH (0.3 μg/kg BW); (iii) VP (1 μg/kg BW) and (iv) bCRH (0.3 μg/kg BW) + VP (1 μg/kg BW). Jugular blood samples were collected at 15‐min intervals for 4 h pre‐ and for 6 h post‐treatment; samples were also taken at 1, 5 and 10 min post‐treatment. Plasma concentration of ACTH did not differ among treatment groups for the 4‐h pre‐treatment period. At 1 min post‐treatment, bCRH + VP, VP and bCRH increased ACTH secretion by 22.4‐, 9.6‐ and 2.2‐fold, respectively, relative to Control (32.7 ± 7.2 pg/ml). Maximal plasma concentration of ACTH occurred at 5, 10 and 15 min post‐treatment for the VP (1017.7 ± 219.9 pg/ml), bCRH + VP (1399.8 ± 260.1 pg/ml) and bCRH (324.8 ± 126.2 pg/ml) treatment groups respectively. Both the in vitro and in vivo data demonstrated that while VP acutely activates the bovine pituitary‐adrenal axis, CRH‐induced ACTH secretion is slower in onset but of longer duration. The present study also provides insight into the dynamics of ACTH and cortisol (CS) responsiveness to CRH and VP in cattle.
Pharmacokinetics of Intramuscular Ketamine in Young Ostriches Premedicated with Romifidine
Authors: De Lucas J. J. , Rodríguez C. , Marín M. , González F. , Ballesteros C. , San Andrés M. I.
Published: January 2007

Ketamine is a short‐acting dissociative anaesthetic for chemical restraint and surgical anaesthesia in domestic and non‐domestic animals. The present study was designed to determine the pharmacokinetics of a single dose of ketamine (10 mg/kg) after intramuscular (i.m.) administration to young ostriches premedicated with romifidine. Ketamine was rapidly absorbed after i.m. administration. Maximal ketamine concentration (Cmax) of 2.93 ± 0.61 μg/ml was reached at 12.5 ± 2.50 min and thereafter ketamine concentrations decreased rapidly. The elimination half‐life (t1/2z) obtained was 62.37 ± 17.37 min and mean residence time (MRT) was 77.33 ± 19.12 min. The area under the curve (AUC) was 114.19 ± 15.76 μg·min/ml.
Plasma Antioxidant Capacity in Dogs with Naturally Occurring Heart Diseases
Authors: Hetyey C. S. , Manczur F. , Dudás‐Györki Z. , Reiczigel J. , Ribiczey P. , Vajdovich P. , Vörös K.
Published: January 2007

The aim of the study was to compare the plasma levels of antioxidants by measuring total antioxidant activity (TAS) and ferric reducing ability of the plasma (FRAP) in healthy dogs and in those that are suffering from dilated cardiomyopathy (DCM) or from mitral endocardiosis (ME). Dogs with echocardiographically diagnosed ME (10 dogs) as well as DCM (23 dogs) were sampled. Of dogs with DCM, eight having DCM with sinus rhythm (SR) were included in the DCM‐SR group and 15 having DCM with atrial fibrillation (AF) in the DCM‐AF group. Total antioxidant levels measured by TAS assay differed neither significantly between the cardiac patients and the control group nor between the heart disease groups. Ferric reducing ability of the plasma in animals with cardiac disease was significantly higher than in the control animals, and the difference was also significant in between the two DCM groups. However, the differences between the antioxidant levels of the DCM and ME groups did not reach significance in none of the antioxidant (TAS and FRAP) tests. Summarizing the results of this study it can be concluded that there is an increased antioxidant reactivity detected by the FRAP, but not by the TAS assay in the blood of dogs with naturally occurring cardiac disorders. The magnitude of this increase seems to be more affected rather by the severity of the cardiac insufficiency and/or by the heart rate or rhythm disorder than by the underlying heart disease itself.
Infusion of anti‐nerve growth factor into the cisternum magnum of chick embryo leads to decrease cell production in the cerebral cortical germinal epithelium
Authors: Mashayekhi F. , Salehi Z.
Published: January 2007

There has been considerable recent progress in understanding the processes involved in cerebral cortical development. Several mitogenic and trophic factors have been implicated in the processes of cortical cell proliferation and differentiation. Anti‐nerve growth factor (NGF) antibody was administered to 15 days chick foetuses through the cisternum magnum. Control group received phosphate buffered saline (PBS). To identify cells born in the cerebral cortex at the time of antibody or PBS injection, 5′‐bromo‐2′‐ deoxyuridine was administered to the foetuses by intravenous injection into an outlying vein using micromanipulation. After injection, the foetuses were re‐incubated for another 3 days. All the foetuses were collected on day 18, the brains fixed in paraformaldehyde, cut with a microtome and stained with methyl green pyronin and anti‐NGF antibody. Quantitative measurements showed that the thickness of the germinal epithelium (GE) and cerebral cortex in the anti‐NGF antibody injected foetuses was decreased when compared with normal control embryos. The number of cells produced in the GE of antibody injected foetuses was decreased when compared with normal control embryos. The results from this study using neutralizing antibody suggests that NGF is an important factor in cerebral cortical development, stimulating neuronal precursor proliferation.
Gadamer and Theology
Authors: EBERHARD PHILIPPE
Published: January 2007

Abstract:  This article examines the role of theology in Gadamer and what theology can learn from it. Gadamer owes a great deal to theology for his account of understanding, but the few times he reveals his own theology he does not apply to it the insights he gleaned from theology. This article proposes to open more fully the door back to theology Gadamer left ajar.

Following a middle‐voiced reading of understanding as standing under, it articulates theology in terms of a middle‐voiced process in and of which we partake when we get involved in it.
Stretch‐induced injury in organotypic hippocampal slice cultures reproduces in vivo post‐traumatic neurodegeneration: role of glutamate receptors and voltage‐dependent calcium channels
Authors: Cater Heather L. , Gitterman Daniel , Davis Susan M. , Benham Christopher D. , Morrison Barclay , Sundstrom Lars E.
Published: January 2007

The relationship between an initial mechanical event causing brain tissue deformation and delayed neurodegeneration in vivo is complex because of the multiplicity of factors involved. We have used a simplified brain surrogate based on rat hippocampal slices grown on deformable silicone membranes to study stretch‐induced traumatic brain injury. Traumatic injury was induced by stretching the culture substrate, and the biological response characterized after 4 days. Morphological abnormalities consistent with traumatic injury in humans were widely observed in injured cultures. Synaptic function was significantly reduced after a severe injury. The N‐methyl‐D‐aspartate (NMDA) receptor antagonist MK‐801 attenuated neuronal damage, prevented loss of microtubule‐associated protein 2 immunoreactivity and attenuated reduction of synaptic function. In contrast, the NMDA receptor antagonists 3‐[(R)‐2‐carboxypiperazin‐4‐yl]‐propyl‐1‐phosphonic acid (CPP) and GYKI53655, were neuroprotective in a moderate but not a severe injury paradigm. Nifedipine, an L‐type voltage‐dependent calcium channel antagonist was protective only after a moderate injury, whereas ω‐conotoxin attenuated damage following severe injury. These results indicate that the mechanism of damage following stretch injury is complex and varies depending on the severity of the insult. In conclusion, the pharmacological, morphological and electrophysiological responses of organotypic hippocampal slice cultures to stretch injury were similar to those observed in vivo. Our model provides an alternative to animal testing for understanding the mechanisms of post‐traumatic delayed cell death and could be used as a high‐content screen to discover neuroprotective compounds before advancing to in vivo models.
Oxidative stress activates protein tyrosine kinase and matrix metalloproteinases leading to blood–brain barrier dysfunction
Authors: Haorah James , Ramirez Servio H. , Schall Kathy , Smith Daniel , Pandya Rita , Persidsky Yuri
Published: January 2007

The blood–brain barrier (BBB) formed by brain microvascular endothelial cells (BMVEC) regulates the passage of molecules and leukocytes in and out of the brain. Oxidative stress is a major underlying cause of neurodegenerative and neuroinflammatory disorders and BBB injury associated with them. Using human BMVEC grown on porous membranes covered with basement membrane (BM) matrix (BBB models), we demonstrated that reactive oxygen species (ROS) augmented permeability and monocyte migration across BBB. ROS activated matrix metalloproteinases (MMP‐1, ‐2, and ‐9) and decreased tissue inhibitors of MMPs (TIMP‐1 and ‐2) in a protein tyrosine kinase (PTK)‐dependent manner. Increase in MMPs and PTK activities paralleled degradation of BM protein and enhanced tyrosine phosphorylation of tight junction (TJ) protein. These effects and enhanced permeability/monocyte migration were prevented by inhibitors of MMPs, PTKs, or antioxidant suggesting that oxidative stress caused BBB injury via degradation of BM protein by activated MMPs and by PTK‐mediated TJ protein phosphorylation. These findings point to new therapeutic interventions ameliorating BBB dysfunction in neurological disorders such as stroke or neuroinflammation.
Role of activity‐dependent mechanisms in the control of dopaminergic neuron survival
Authors: Michel Patrick P. , Alvarez‐Fischer Daniel , Guerreiro Serge , Hild Audrey , Hartmann Andreas , Hirsch Etienne C.
Published: January 2007

Dopaminergic neurons that constitute the nigrostriatal pathway are characterized by singular electrical properties that allow them to discharge in vivo spontaneously in a spectrum of patterns ranging from pacemaker to random and bursting modes. These electrophysiological features allow dopaminergic neurons to optimize the release of dopamine in their terminal fields. However, there is emerging evidence indicating that electrical activity might also participate in the control of dopaminergic neuron survival, not only during development, but also in the adult brain, thus raising the possibility that alterations in ionic currents could contribute actively to the demise of these neurons in Parkinson disease. This review focuses on the mechanisms by which activity‐dependent mechanisms might modulate dopaminergic cell survival.
Enhancing the benefit of continuing professional development: a randomized controlled study of personal development plans for dentists
Authors: Bullock Alison , Firmstone Vickie , Frame John , Bedward Julie
Published: January 2007

The aim of this study was to investigate the implementation and impact of personal development plans (PDPs) for UK dentists. Eighty‐seven UK dentists were divided into two groups, experimental (n = 42; supported by a tutor in developing a PDP) and control (n = 45). Both groups recorded their continuing professional development (CPD) activities over a 6‐month period in 2002 and rated their relation to learning needs, extent of new learning, immediate and longer‐term impact on practice. All in the experimental group were interviewed 1 month after completing a PDP, 6 months later they rated the match of their CPD activities with their PDP, and at 12 months a sub‐sample of 10 were interviewed. The results show that developing a PDP with the aid of a tutor was viewed positively. Participants undertook a median number of 17 educational activities in the 6‐month period (mean of 50 hours). Most frequent activities were reading and courses. Ratings for impact, both immediate and later, were higher among the experimental group who had been supported in the development of a PDP, and this was particularly true for reading. For courses, the impact of the intervention was more clearly in evidence when there was a good match between the PDP and the CPD activities actually undertaken. In conclusion, these data, based on self‐ratings within a controlled study, show that dentists in the experimental group, who were supported to develop a PDP, derived greater benefit from their CPD than the control group.
Zinc in wound healing: Theoretical, experimental, and clinical aspects
Authors: Lansdown Alan B. G. , Mirastschijski Ursula , Stubbs Nicky , Scanlon Elizabeth , Ågren Magnus S.
Published: January 2007

Zinc is an essential trace element in the human body and its importance in health and disease is appreciated. It serves as a cofactor in numerous transcription factors and enzyme systems including zinc‐dependent matrix metalloproteinases that augment autodebridement and keratinocyte migration during wound repair. Zinc confers resistance to epithelial apoptosis through cytoprotection against reactive oxygen species and bacterial toxins possibly through antioxidant activity of the cysteine‐rich metallothioneins. Zinc deficiency of hereditary or dietary cause can lead to pathological changes and delayed wound healing. Oral zinc supplementation may be beneficial in treating zinc‐deficient leg ulcer patients, but its therapeutic place in surgical patients needs further clarification. Topical administration of zinc appears to be superior to oral therapy due to its action in reducing superinfections and necrotic material via enhanced local defense systems and collagenolytic activity, and the sustained release of zinc ions that stimulates epithelialization of wounds in normozincemic individuals. Zinc oxide in paste bandages (Unna boot) protects and soothes inflamed peri‐ulcer skin. Zinc is transported through the skin from these formulations, although the systemic effects seem insignificant. We present here the first comprehensive account of zinc in wound management in relation to current concepts of wound bed preparation and the wound‐healing cascade. This review article suggests that topical zinc therapy is underappreciated even though clinical evidence emphasizes its importance in autodebridement, anti‐infective action, and promotion of epithelialization.
Streptolysin O enhances keratinocyte migration and proliferation and promotes skin organ culture wound healing in vitro
Authors: Tomic‐Canic Marjana , Mamber Stephen W. , Stojadinovic Olivera , Lee Brian , Radoja Nadezda , McMichael John
Published: January 2007

ML‐05, a modified form of the hemolytic and cytotoxic bacterial toxin, streptolysin O, is currently being investigated as a treatment for collagen‐related disorders such as scleroderma and fibrosis. Furthermore, ML‐05 may be effective in promoting wound healing and alleviating the formation of hypertrophic scars and keloids. To investigate the effects of ML‐05 on wound‐healing processes, in vitro wound‐healing scratch assays (using human primary epidermal keratinocytes and dermal fibroblasts) and a human skin organ culture wound model were utilized. ML‐05 markedly enhanced keratinocyte migration and proliferation in wound scratch assays. ML‐05 did not affect either proliferation or migration of dermal fibroblasts, indicating that ML‐05's effects on cell migration/proliferation may be keratinocyte‐specific. ML‐05 was tested in a dose‐dependent manner in a skin organ culture wound model using two different application methods: Through the culture media (dermal exposure) or direct topical treatment of the wound surface. ML‐05 was found to accelerate wound healing as measured by reepithelialization, particularly after topical application. Therefore, ML‐05 may have potential as a wound‐healing agent that promotes reepithelialization through stimulation of keratinocyte migration and proliferation.
A cold Early Palaeozoic subduction zone in the North Qilian Mountains, NW China: petrological and U‐Pb geochronological constraints
Authors: ZHANG J. X. , MENG F. C. , WAN Y. S.
Published: January 2007

The north Qilian high‐pressure (HP)/low‐temperature (LT) metamorphic belt is composed mainly of blueschists, eclogites and greenschist facies rocks. It formed within an Early Palaeozoic accretionary wedge associated with the subduction of the oceanic crust and is considered to be one of the best preserved HP/LT metamorphic belts in China. Here we report new lawsonite‐bearing eclogites and eclogitic rocks enclosed within epidote blueschists in the North Qilian Mountains. Five samples contain unaltered lawsonite coexisting with omphacite and phengite as inclusions in garnet, indicating eclogite facies garnet growth and lawsonite pseudomorphs were observed in garnet from an additional 11 eclogites and eclogitic rocks. Peak pressure conditions estimated from lawsonite omphacite‐phengite‐garnet assemblages were 2.1–2.4 GPa at temperatures of 420–510 °C, in or near the stability field of lawsonite eclogite, and implying formation under an apparent geothermal gradient of 6–8 °C km−1, consistent with metamorphism in a cold subduction zone. SHRIMP U‐Pb dating of zircon from two lawsonite‐bearing eclogitic metabasites yields ages of 489 ± 7 Ma and 477 ± 16 Ma, respectively. CL images and mineral inclusions in zircon grains indicate that these ages reflect an eclogite facies metamorphism. An age of 502 ± 16 Ma is recorded in igneous cores of zircon grains from one lawsonite pseudomorph‐bearing eclogite, which is in agreement with the formation age of Early Ordovician for some ophiolite sequences in the North Qilian Mountains, and may be associated with a period of oceanic crust formation. The petrological and chronological data demonstrate the existence of a cold Early Palaeozoic subduction zone in the North Qilian Mountains.
Imputation Approaches for Estimating Diagnostic Accuracy for Multiple Tests from Partially Verified Designs
Authors: Albert Paul S.
Published: January 2007

SummaryInterest often focuses on estimating sensitivity and specificity of a group of raters or a set of new diagnostic tests in situations in which gold standard evaluation is expensive or invasive. Various authors have proposed semilatent class modeling approaches for estimating diagnostic accuracy in this situation. This article presents imputation approaches for this problem. I show how imputation provides a simpler way of performing diagnostic accuracy and prevalence estimation than the use of semilatent modeling. Furthermore, the imputation approach is more robust to modeling assumptions and, in general, there is only a moderate efficiency loss relative to a correctly specified semilatent class model. I apply imputation to a study designed to estimate the diagnostic accuracy of digital radiography for gastric cancer. The feasibility and robustness of imputation is illustrated with analysis, asymptotic results, and simulations.
Mapping of the functional phosphate groups in the catalytic core of deoxyribozyme 10–23
Authors: Nawrot Barbara , Widera Kinga , Wojcik Marzena , Rebowska Beata , Nowak Genowefa , Stec Wojciech J.
Published: January 2007

The RNA phosphodiester bond cleavage activity of a series of 16 thio‐deoxyribozymes 10–23, containing a P‐stereorandom single phosphorothioate linkage in predetermined positions of the catalytic core from P1 to P16, was evaluated under single‐turnover conditions in the presence of either 3 mmMg2+or 3 mmMn2+. A metal‐specificity switch approach permitted the identification of nonbridging phosphate oxygens (proRPorproSP) located at seven positions of the core (P2, P4 and P9–13) involved in direct coordination with a divalent metal ion(s). By contrast, phosphorothioates at positions P3, P6, P7 and P14–16 displayed no functional relevance in the deoxyribozyme‐mediated catalysis. Interestingly, phosphorothioate modifications at positions P1 or P8 enhanced the catalytic efficiency of the enzyme. Among the tested deoxyribozymes, thio‐substitution at position P5 had the largest deleterious effect on the catalytic rate in the presence of Mg2+, and this was reversed in the presence of Mn2+. Further experiments with thio‐deoxyribozymes of stereodefined P‐chirality suggested direct involvement of both oxygens of the P5 phosphate and theproRPoxygen at P9 in the metal ion coordination. In addition, it was found that the oxygen atom at C6 of G6contributes to metal ion binding and that this interaction is essential for 10–23 deoxyribozyme catalytic activity.
“Something Special to Offer”: Meritocracy in the Universities
Authors: Kabaservice Geoffrey
Published: January 2007

Life, as the poets have observed, imitates art. Nicholas Lemann has produced the most fascinating brief against meritocracy since Michael Young's 1957 novel that gave the world the term. And Lemann's critique is in a way prefigured in the populist “Chelsea Manifesto” that appears near the end of Young's The Rise of the Meritocracy:

The classless society would be one which both possessed and acted upon plural values. Were we to evaluate people, not only according to their intelligence and their education, their occupation, and their power, but according to their kindliness and their courage, their imagination and sensitivity, their sympathy and generosity, there could be no classes. Who would be able to say that the scientist was superior to the porter with admirable qualities as a father, the civil servant with unusual skill at gaining prizes superior to the lorry-driver with unusual skill at growing roses?

The Lemann Manifesto, so to speak, does not appear until the Afterword of The Big Test, but its message permeates “The Master Plan,” the second part of the book. In this section, Lemann takes on the postwar rise of the University of California system and the transformation of old “Episcopacy” institutions such as Yale into academic powerhouses with highly selective undergraduate admissions. He also introduces the issue of race and the apparent contradiction that low African-American SAT scores pose to the idea of meritocracy as a fair system of social mobility.
Academy Students in the Mid-Nineteenth Century: Social Geography, Demography, and the Culture of Academy Attendance
Authors: Beadie Nancy
Published: January 2007

Academies and academy students increased substantially in number during the period from the American Revolution to the Civil War. Why? Who were these students and what did academy attendance mean to them? Theodore R. Sizer asked these questions in 1964, but his ability to answer them was limited by the absence of studies that focused on academy students. In this essay I reexamine Sizer's understanding of academies in light of evidence provided by subsequent studies of student populations. These studies include my own comparative analysis of data from nearly 500 Regents academies that operated in New York State between 1835 and 1890, as well as in-depth case studies of individual institutions by myself and others.
Hispanic, Latino, Chicano, or “Other”?: Deconstructing the Relationship between Historians and Hispanic-American Educational History
Authors: MacDonald Victoria-María
Published: January 2007

The educational history of Hispanic Americans is not a “new” history. Hispanic peoples began exploration, settlement, and even schooling in North America in the sixteenth century. A more appropriate metaphor is to think of Hispanic educational history as a rich, unearthed site awaiting the work of archivists and researchers. There is no doubt that the large post-1965 immigration of Latinos to the United States renewed interest among scholars in the history of these peoples. Yet contemporary social, political, economic, and educational issues raise the troubling question of why Hispanic-American history has remained neglected for so long. This essay is a beginning towards understanding the relationship between historians and the educational history of Hispanic Americans during the last century. Specifically, this historiographical inquiry examines some barriers that have dissuaded scholars from exploring the history of Latino influences in North America, assesses current writings, and recommends new directions for scholars wishing to pursue inquiry into the field of Hispanic-American educational history.
“The Pacific Era Has Arrived”: Transnational Education among Japanese Americans, 1932–1941
Authors: Azuma Eiichiro
Published: January 2007

Looking back on the two years at Keisen Girls' School, I am so grateful for the opportunity to have been able to study here…. Our teachers have taught us that it was mistaken if we simply aspired to mimic the ways of Japanese woman. Cognizant of our special position as Americans of Japanese ancestry, we must instead strive to promote the U.S.-Japan friendship. Furthermore, we must adapt the merits of the Japanese spirit [that we have acquired here] to our Americanism. Back in the United States, we will dedicate ourselves to the good of our own society as best possible citizens, cooperating with Americans of other races and learning from each other…. Such is the mission of the Nisei as a bridge between Japan and the United States—one that we have come to appreciate [through our schooling in Japan].

Just about two years before Pearl Harbor, a young Japanese American woman took this pledge to herself when she completed a special study program in Tokyo, Japan. Although the shadow of war loomed increasingly over the Pacific, thousands of American-born Japanese (Nisei) youth like her flocked to their parents' native land during the 1930s to pursue cultural and language learning, as well as formal secondary and higher education. In any given year following 1932, an estimated 1,500 young Nisei students from North America resided in Tokyo and other urban areas of Japan. Often referred to as Kibei after returning to their native land, these young women and men attempted to embrace their ethnic heritage and identity during their sojourn in Japan with the support of Japanese educators.
Writing Autobiographies on Brown in the History Classroom
Authors: Weis Tracey M.
Published: January 2007

About fifteen years ago, I heard Anne Firor Scott, W.K. Boyd Professor Emerita at Duke University, recount an exercise that she assigned to incoming Duke students: “How did your hometown respond to the Brown decision?” Students were required to consult local newspapers and public records, to interview relatives, neighbors, teachers, and public officials, and to carry out other research to address this query. Intrigued by this investigation, I devised an autobiographical version of this writing assignment for students at my northern campus. For the past several years, I have launched sections of my African American History II course with a first-person version of Scott's inquiry: “How has race, and especially the Brown decision, affected your educational history?” It began as a first-day, in-class writing assignment, but the most recent iteration asks them to draw upon course readings and library research resources to illuminate their personal experiences of race and education, from elementary grades to present-day college years. Students submit their first drafts near the beginning of the semester, reflect on historical readings and class discussions, and then revise their autobiographies by the end of the course. Student postings on our electronic discussion board make their reflections more public than traditional writing assignments, sparking discussions about how our perspectives have been shaped by different experiences of race and education.
Effective Mass of an Oscillating Spring
Authors: Rodríguez Eduardo E. , Gesnouin Gabriel A.
Published: January 2007

We present an experimental method to obtain the effective mass of an unloaded oscillating spring. We measure the period T(n) of the partial springs that result when hanging n of the total N coils of a given spring. Data are correlated with the expectation of a simple model for T(n) that takes into account the effective mass of the hanging spring. We analyze results for metal and plastic springs of different masses and strengths, and conclude that the method provides the effective mass with a good degree of reliability.
Trioxaquines Are New Antimalarial Agents Active on All Erythrocytic Forms, Including Gametocytes
Authors: Benoit-Vical Françoise , Lelièvre Joël , Berry Antoine , Deymier Caroline , Dechy-Cabaret Odile , Cazelles Jérôme , Loup Christophe , Robert Anne , Magnaval Jean-François , Meunier Bernard
Published: January 2007

Malaria is the third most significant cause of infectious disease in the world. The search for new antimalarial chemotherapy has become increasingly urgent due to parasite resistance to classical drugs. Trioxaquines are synthetic hybrid molecules containing a trioxane motif (which is responsible for the antimalarial activity of artemisinin) linked to an aminoquinoline entity (which is responsible for the antiplasmodial properties of chloroquine). These trioxaquines are highly potent against young erythrocytic stages of
Plasmodium falciparum
and exhibit efficient activity in vitro against chloroquine-sensitive and -resistant strains of
P. falciparum
(50% inhibitory concentration, 4 to 32 nM) and are also active in vivo against
P. vinckei petteri
and
P. yoelii nigeriensis
in suppressive and curative murine tests. The trioxaquine DU1302 is one of these promising antimalarial agents. The present study confirms the absence of toxicity of this drug on cell lines and in a mice model. Moreover, DU1302 exhibits potent activity against gametocytes, the form transmitted by mosquitoes, as killing of the gametocytes is essential to limit the spread of malaria. The ease of chemical synthesis of this trioxaquine prototype should be considered an additional advantage and would make these drugs affordable without perturbations of the drug supply.
Miltefosine Affects Lipid Metabolism in
Leishmania donovani
Promastigotes
Authors: Rakotomanga M. , Blanc S. , Gaudin K. , Chaminade P. , Loiseau P. M.
Published: January 2007

Miltefosine (hexadecylphosphocholine [HePC]) is the first orally active antileishmanial drug. Transient HePC treatment of
Leishmania donovani
promastigotes at 10 μM significantly reduced the phosphatidylcholine content and enhanced the phosphatidylethanolamine (PE) content in parasite membranes, suggesting a partial inactivation of PE-
N
-methyltransferase. Phospholipase D activity did not seem to be affected by HePC. In addition, the enhancement of the lysophosphatidylcholine content could be ascribed to phospholipase A2 activation. Moreover, transient HePC treatment had no effect on the fatty acid alkyl chain length or the fatty acid unsaturation rate. Concerning sterols, we found a strong reduction of the C
24
alkylated sterol content, and the enhancement of the cholesterol content could be the result of the HePC condensation effect with sterols. Because some of the effects observed after transient HePC treatment were different from those previously observed in HePC-resistant parasites, it could be hypothesized that continuous in vitro drug pressure induces the mechanisms of regulation in
Leishmania
lipid metabolism.
Pharmacokinetic/Pharmacodynamic Factors Influencing Emergence of Resistance to Linezolid in an In Vitro Model
Authors: Boak Lauren M. , Li Jian , Rayner Craig R. , Nation Roger L.
Published: January 2007

Emerging resistance threatens the usefulness of linezolid for the treatment of severe infections caused by multidrug-resistant gram-positive bacteria. Optimal pharmacokinetic (PK)/pharmacodynamic (PD) indices have been described for the antimicrobial efficacy of linezolid (area under the concentration-time curve over 24 h at steady state divided by the MIC, >100; the cumulative percentage of a 24-h period that the drug concentration exceeds the MIC under steady-state PK conditions, >85). The aim of this study was to investigate the influence of these PK/PD indices on the development of resistance to linezolid by using an in vitro PK/PD model. Four dosage regimens were simulated over 72 h (two intermittent bolus regimens of 600 mg every 12 h [q12h] and 120 mg q12h and two continuous-infusion regimens of 120 mg/24 h and 30 mg/24 h) against four reference strains: methicillin-resistant
Staphylococcus aureus
(MRSA), heteroresistant vancomycin-intermediate
S. aureus
(hVISA), vancomycin-intermediate
S. aureus
(VISA), and vancomycin-resistant
Enterococcus faecium
(VRE). Linezolid concentrations were measured by high-performance liquid chromatography. Changes in susceptibility were characterized by pre- and posttreatment MIC measurements and population analysis profiles (PAPs). The linezolid concentrations that were achieved closely matched those that were targeted. The simulation with 600 mg q12h provided a >3-log
10
reduction in the number of CFU/ml for all four strains, as did the 120-mg-q12h regimen for hVISA and VISA and the 30-mg/24-h continuous infusion for VRE and VISA. After 72 h of exposure to the 120-mg/24-h continuous-infusion simulation, the area under the PAP curve for all strains increased substantially (40 to 178%); increases in the MICs for the MRSA and hVISA strains were observed. The results demonstrate that PK/PD considerations are important in optimizing both antibacterial activity and the development of resistance to linezolid. The potential for resistance development appears to be higher when a constant concentration is maintained in the vicinity of the MIC of the bacteria.