bluuebunny/crossref_metadata_2025 huggingface dataset:
Regression and persistence: remodelling in a tissue engineered axial vascular assembly
Authors: Polykandriotis E. , Euler S. , Arkudas A. , Pryymachuk G. , Beier J. P. , Greil P. , Dragu A. , Lametschwandtner A. , Kneser U. , Horch R. E.
Published: June 2009

In later stages of vasculoangiogenesis a vascular network is going through a metamorphosis for optimal perfusion and economy of energy. In this study we make a quantitative approach to phenomena of remodelling in a bioartificial neovascular network and suggest variance of calibre as a parameter of neovascular maturation. For this study, 18 male Lewis rats were subjected to the AV loop operation in combination with a hard porous biogenic matrix and an isolation chamber. The animals were allocated into three groups for different explantation intervals set to 2, 4 and 8 weeks, respectively. Collective attributes like vascular density, percent fractional area and variance of calibre were evaluated for a predefined region of interest (ROI). Late morphogenesis was evaluated by means of scanning electron microscopy. After the fourth week the absolute number of vessels within the ROI decreased (P < 0.03) whereas, on the contrary, the fractional area of all segments increased (P < 0.02). The variance in calibre was significantly increased in the 8‐week group (P < 0.05). Lymphatic growth after week 4, early pericyte migration as well as intussusceptive angiogenesis were identified immunohistologically. Phenomena of remodelling were evaluated quantitatively in a neovascular network and variance could be proposed as a parameter of net vascular maturation.
Synergistic effects of telmisartan and simvastatin on endothelial progenitor cells
Authors: Steinmetz Martin , Brouwers Caroline , Nickenig Georg , Wassmann Sven
Published: June 2009

Circulating endothelial progenitor cells (EPC) contribute to endothelial replenishment. Telmisartan is an angiotensin‐receptor blocker with PPARγ‐agonistic properties. PPARγ‐agonists and HMG‐CoA reductase inhibitors have been shown to enhance EPC number and function. We focused on the effects of telmisartan alone or in combination with simvastatin on EPC. EPC were isolated from healthy human volunteers, cultured and stimulated with telmisartan, simvastatin, or the combination of telmisartan and simvastatin. Telmisartan significantly increased the number of acLDL/lectin double‐positive early EPC, the number of colony forming units (EC‐CFU) as well as EPC migratory capacity, inhibited TNFα‐induced EPC apoptosis and reduced glucose‐induced oxidative stress. The telmisartan effect was dose‐dependent and could be inhibited by GW9662, indicating a PPARγ‐dependent mechanism. The combination of telmisartan and simvastatin led to a significant additive increase in EPC count and function. In wild‐type mice, systemic treatment with either telmisartan or simvastatin elevated the number of sca‐1/flk‐1‐positive EPC in bone marrow and peripheral blood, spleen‐derived acLDL/lectin double‐positive EPC, EPC migration and EC‐CFU. Consistent with the in vitro findings, the combination of telmisartan and simvastatin resulted in a further enhancement of EPC counts. Re‐endothelialization after carotid injury was significantly enhanced by telmisartan, simvastatin and the combination. Telmisartan increases EPC number and function mediated by a PPARγ‐dependent mechanism. This effect is further enhanced by combination with simvastatin, suggesting a synergistic activation of potentially diverse intracellular pathways.
An outbreak of pneumonia associated with S. pneumoniae at a military training facility in Finland in 2006
Authors: VAINIO ANNI , LYYTIKÄINEN OUTI , SIHVONEN REETTA , KAIJALAINEN TARJA , TEIRILÄ LAURA , RANTALA MERJA , LEHTINEN PIRKKO , RUUSKA PEKKA , VIROLAINEN ANNI
Published: June 2009

Streptococcus pneumoniae is a well‐known cause of community‐acquired bacterial pneumonia. The purpose of this study was to assess the cause and extent of the outbreak of pneumonia which occurred among military recruits following a 1‐week hard encampment in Finland. We also assessed the carriage rate and molecular characteristics of the S. pneumoniae isolates. All pneumococcal isolates were studied for antibiotic susceptibility, serotyped, genotyped by multilocus sequence typing (MLST), and the presence of pneumococcal rlrA pilus islet was detected. The genotype results defined by MLST corresponded with the serotype results. S. pneumoniae serotype 7F, ST2331, seemed to be associated with an outbreak of pneumonia and nasopharyngeal carriage among 43 military recruits. Of the 43 military recruits, five (12%) were hospitalized with pneumonia and two (40%) of them were positive for S. pneumoniae serotype 7F, ST2331 by blood culture. Eighteen (42%) of the 43 men were found to be positive for S. pneumoniae by nasopharyngeal culture, and nine (50%) of them carried pneumococcal serotype 7F, ST2331. The outbreak strain covered 55% of all the pneumococcal findings. Outbreaks of invasive pneumococcal disease seem to occur in a crowded environment such as a military training facility even among previously healthy young men.
Inactivation of the rhlA gene in Pseudomonas aeruginosa prevents rhamnolipid production, disabling the protection against polymorphonuclear leukocytes
Authors: VAN GENNIP MARIA , CHRISTENSEN LOUISE DAHL , ALHEDE MORTEN , PHIPPS RICHARD , JENSEN PETER ØSTRUP , CHRISTOPHERSEN LARS , PAMP SÜNJE JOHANNA , MOSER CLAUS , MIKKELSEN PER JENSEN , KOH ANDREW Y. , TOLKER‐NIELSEN TIM , PIER GERALD B. , HØIBY NIELS , GIVSKOV MICHAEL , BJARNSHOLT THOMAS
Published: June 2009

Many of the virulence factors produced by the opportunistic human pathogen Pseudomonas aeruginosa are quorum‐sensing (QS) regulated. Among these are rhamnolipids, which have been shown to cause lysis of several cellular components of the human immune system, e.g. monocyte‐derived macrophages and polymorphonuclear leukocytes (PMNs). We have previously shown that rhamnolipids produced by P. aeruginosa cause necrotic death of PMNs in vitro. This raises the possibility that rhamnolipids may function as a ‘biofilm shield’in vivo, which contributes significantly to the increased tolerance of P. aeruginosa biofilms to PMNs. In the present study, we demonstrate the importance of the production of rhamnolipids in the establishment and persistence of P. aeruginosa infections, using an in vitro biofilm system, an intraperitoneal foreign‐body model and a pulmonary model of P. aeruginosa infections in mice. Our experimental data showed that a P. aeruginosa strain, unable to produce any detectable rhamnolipids due to an inactivating mutation in the single QS‐controlled rhlA gene, did not induce necrosis of PMNs in vitro and exhibited increased clearance compared with its wild‐type counterpart in vivo. Conclusively, the results support our model that rhamnolipids are key protective agents of P. aeruginosa against PMNs.
New developments in our understanding of acne pathogenesis and treatment
Authors: Kurokawa Ichiro , Danby F. William , Ju Qiang , Wang Xiuli , Xiang Leihong Flora , Xia Longqing , Chen WenChieh , Nagy István , Picardo Mauro , Suh Dae Hun , Ganceviciene Ruta , Schagen Silke , Tsatsou Fragkiski , Zouboulis Christos C.
Published: June 2009

Abstract:  Interest in sebaceous gland physiology and its diseases is rapidly increasing. We provide a summarized update of the current knowledge of the pathobiology of acne vulgaris and new treatment concepts that have emerged in the last 3 years (2005–2008). We have tried to answer questions arising from the exploration of sebaceous gland biology, hormonal factors, hyperkeratinization, role of bacteria, sebum, nutrition, cytokines and toll‐like receptors (TLRs). Sebaceous glands play an important role as active participants in the innate immunity of the skin. They produce neuropeptides, excrete antimicrobial peptides and exhibit characteristics of stem cells. Androgens affect sebocytes and infundibular keratinocytes in a complex manner influencing cellular differentiation, proliferation, lipogenesis and comedogenesis. Retention hyperkeratosis in closed comedones and inflammatory papules is attributable to a disorder of terminal keratinocyte differentiation. Propionibacterium acnes, by acting on TLR‐2, may stimulate the secretion of cytokines, such as interleukin (IL)‐6 and IL‐8 by follicular keratinocytes and IL‐8 and ‐12 in macrophages, giving rise to inflammation. Certain P. acnes species may induce an immunological reaction by stimulating the production of sebocyte and keratinocyte antimicrobial peptides, which play an important role in the innate immunity of the follicle. Qualitative changes of sebum lipids induce alteration of keratinocyte differentiation and induce IL‐1 secretion, contributing to the development of follicular hyperkeratosis. High glycemic load food and milk may induce increased tissue levels of 5α‐dihydrotestosterone. These new aspects of acne pathogenesis lead to the considerations of possible customized therapeutic regimens. Current research is expected to lead to innovative treatments in the near future.
An imbalance in Akt/mTOR is involved in the apoptotic and acantholytic processes in a mouse model of pemphigus vulgaris
Authors: Pretel Maider , España Agustín , Marquina Miren , Pelacho Beatriz , López‐Picazo Jose María , López‐Zabalza Maria J.
Published: June 2009

Abstract: Pemphigus vulgaris (PV) is an autoimmune blistering disease characterized by the presence of IgG autoantibodies against Dsg3. Our aim was to investigate the molecular events implicated in the development and localization of apoptosis and acantholysis in PV. We used a passive transfer mouse model together with immunohistochemical (IHC) techniques and the TUNEL assay, with quantification analysis in the basal layer of the epidermis. The activated signalling molecules analysed and apoptotic cells detected showed an identical localization. Herein, we found for the first timein vivoan increased expression of activated HER receptor isoforms in the basal layer in PV lesions. Besides, we observed the almost total lack of activated Akt compared with a higher level of activated mTOR within the basal cells of the epidermis. Our observations strongly support that the restriction of acantholysis to the basal layer may be due, at least in part, to the selective and increased presence of activated HER receptor isoforms in these cells. After phosphorylation of HER receptor isoforms, intracellular signalling pathways are activated in the basal layer. In addition, the imbalance in Akt/mTOR that takes place in the basal cells may provide intracellular signals necessary for the development of apoptosis and acantholysis.
Oral supplementation with Lactobacillus rhamnosus CGMCC 1.3724 prevents development of atopic dermatitis in NC/NgaTnd mice possibly by modulating local production of IFN‐γ
Authors: Tanaka Akane , Jung Kyungsook , Benyacoub Jalil , Prioult Guenolée , Okamoto Noriko , Ohmori Keitaro , Blum Stephanie , Mercenier Annick , Matsuda Hiroshi
Published: June 2009

Abstract:  Prevalence of allergies has increased during the last two decades. Alteration of the gut microbiota composition is thought to play a crucial role in development of atopic diseases. Oral administration of probiotics has been reported to treat and/or prevent symptoms of atopic diseases in infants, but the results are still controversial. We investigated the potential efficacy of dietary interventions by a probiotic strain on prevention and treatment of atopic dermatitis (AD) in a human‐like AD model, NC/NgaTnd mice by perinatal administration. Pregnant NC/NgaTnd mice were orally treated with the probiotic strain Lactobacillus rhamnosus CGMCC 1.3724 (LPR), which was followed by treatment of pups until 12 weeks of age. LPR‐treated mice exhibited significant lower clinical symptoms of dermatitis, reduced scratching frequency, lower levels of plasma total Immunoglobulin E and higher levels of interferon‐γ in skin biopsies, compared with untreated mice. The protective effect was also observed when mice started to be treated at weaning time (5 weeks of age) even with limited supplementation period of 2 weeks. However, treatment of mice with the probiotic starting 1 week after the onset of the disease (8 weeks of age) had limited effects. The usefulness of LPR for primary prevention of AD was supported.
A review of genetic disorders of hypopigmentation: lessons learned from the biology of melanocytes
Authors: Dessinioti Clio , Stratigos Alexander J. , Rigopoulos Dimitris , Katsambas Andreas D.
Published: June 2009

Abstract:  Inherited diseases of pigmentation were among the first traits studied in humans because of their easy recognition. The discovery of genes that regulate melanocytic development and function and the identification of disease‐causative mutations have greatly improved our understanding of the molecular basis of pigmentary genodermatoses and their underlying pathogenetic mechanisms. Pigmentation mutants can account for hypo‐/amelanosis, with or without altered melanocyte number, resulting in different phenotypes, such as Waardenburg syndrome, piebaldism, Hermansky‐Pudlak syndrome, Chediak‐Higashi syndrome, oculocutaneous albinism and Griscelli syndrome. In this review, we summarize the basic concepts of melanocyte biology and discuss how molecular defects in melanocyte development and function can result in the development of hypopigmentary hereditary skin diseases.
Association of thymic stromal lymphopoietin gene −847C>T polymorphism in generalized vitiligo
Authors: Cheong Kyung Ah , Chae Soo‐Cheon , Kim Yong‐Shin , Kwon Hyok Bu , Chung Hun‐Taeg , Lee Ai‐Young
Published: June 2009

Abstracts:  Thymic stromal lymphopoietin (TSLP) induces naïve CD4+ T cells to produce Th2 cytokines. In addition, to low production of Th2 cytokines, strong Th1 response, which plays an important role in vitiligo development, has been induced by blockade of TSLP or TSLP receptor. This study examined whether a functional TSLP polymorphism was associated with vitiligo. One hundred and sixty Korean patients with vitiligo and 568 healthy Korean individuals were examined for the four SNPs of TSLP gene. Luciferase activity was measured for promoter assay. The genotype and allele frequencies of −847C>T polymorphism were lower in vitiligo patients compared with the controls, whereas those of wild type were higher (P = 0.004, P = 0.017 respectively). None the less, the promoter activity of −847C decreased significantly (P = 0.013) compared with −847T, expecting lower TSLP mRNA levels in the polymorphism. Collectively, C allele at the TSLP −847C>T polymorphism may increase susceptibility to generalized vitiligo through decreasing TSLP mRNA expression levels.
Size‐dependent energy storage and winter mortality of perch
Authors: Heermann L. , Eriksson L.‐O. , Magnhagen C. , Borcherding J.
Published: June 2009

Abstract –  Size is a crucial factor affecting the survival of fish during winter. Pond and laboratory experiments with three size classes of perch (small: 40–70 mm, medium: 71–100 mm, large: 101–186 mm) revealed that the feeding history of perch prior to winter is reflected in the amount and type of accumulated energy reserves. The minimal amount of reserves was 2% of the perch’s biomass for fat and 9% for protein. An increase in glycogen levels either reflected mobilisation of energy in the body when perch were starving or an increase in accumulated energy over winter. In the laboratory, only the smallest perch suffered from high mortality rates, even if all were fed with low amounts of food. However, feeding the fish reduced the mortality rate after a certain time lag. Size‐selective mortality rates occurred in the pond experiments as well. Small perch which survived the winter were able to rebuild their energy stores.
Scale as a lurking factor: incorporating scale‐dependence in experimental ecology
Authors: Sandel Brody , Smith Adam B.
Published: June 2009

Ecologists have recognized for decades the importance of spatial scale in ecological processes and patterns, as well as the complications scale poses for understanding ecological mechanisms. Here we highlight the opportunity attention to scale offers experimental ecology. Despite many advantages to considering scale, a review of the literature indicates that multi‐scale experimental studies are rare. Although much work has focused on scale as a primary factor (e.g. island size), we draw attention to scale as a ‘lurking’ variable: one which influences the relationship between two or more variables that are not usually understood to be scale‐dependent.

We highlight three basic observations from which scale‐dependence arises: abundance increases with area, environmental conditions vary across space, and the effect of an organism on its environment is spatially limited. From these arise first‐order scale‐dependence, which relates an ecological variable of interest to a measure of scale. Combining first‐order relationships together, we can produce second‐order scale‐dependencies, which occur when the relationship between two or more variables is mediated by scale. It is these relationships that are of particular interest, as they have the potential to confound experimental results.

Most ecological experiments have incorporated scale either implicitly or not at all. We suggest that an explicit consideration of scale could help resolve some long‐standing debates when scale is turned from a lurking variable into a working variable. Finally, we review and evaluate four different experimental sampling designs and corresponding statistical analyses that can be used to address the effects of scale in ecological experiments.
Indirect blue light does not suppress nocturnal salivary melatonin in humans in an automobile setting
Authors: Lerchl Alexander , Schindler Carina , Eichhorn Karsten , Kley Franziska , Erren Thomas C.
Published: June 2009

Abstract:  In 2007, the International Agency for Research on Cancer (IARC) classified shift work that involves circadian disruption as being probably carcinogenic to humans (Group 2A). In this context, light exposure during the night plays a key role because it can suppress nocturnal melatonin levels when exposures exceed a certain threshold. Blue light around 464 nm is most effective in suppressing melatonin because of the spectral sensitivity of melanopsin, a recently discovered photopigment in retinal ganglion cells; the axons of these cells project to the suprachiasmatic nucleus, a circadian master clock in the brain. Due to advances in light technologies, normal tungsten light bulbs are being replaced by light‐emitting diodes which produce quasi‐monochromatic or white light. The objective of this study was to assess whether the light–melanopsin–melatonin axis might be affected in automobiles at night which employ the new generation diodes. To this end, we have tested in an experimental automobile setting whether indirect blue light (λmax = 465 nm) at an intensity of 0.22 or 1.25 lx can suppress salivary melatonin levels in 12 male volunteers (age range 17–27 years) who served as their own controls. Daytime levels were low (2.7 ± 0.5 pg/mL), and night‐time levels without light exposure were high (14.5 ± 1.1 pg/mL), as expected. Low‐intensity light exposures had no significant effect on melatonin levels (0.22 lx: 17.2 ± 2.8 pg/mL; P > 0.05; 1.25 lx: 12.6 ± 2.0 pg/mL; P > 0.05). It is concluded that indirect blue light exposures in automobiles up to 1.25 lx do not cause unintentional chronodisruption via melatonin suppression.
Melatonin provides neuroprotection by reducing oxidative stress and HSP70 expression during chronic cerebral hypoperfusion in ovariectomized rats
Authors: Ozacmak Veysel H. , Barut Figen , Ozacmak Hale S.
Published: June 2009

Abstract:  Oxidative stress is believed to contribute to functional and histopathologic disturbances associated with chronic cerebral hypoperfusion (CCH) in rats. Melatonin has protective effects against cerebral ischemia/reperfusion injury. This effect has mainly been attributed to its antioxidant properties. In the present study, we evaluate the effects of melatonin on chronic cerebral hypoperfused rats and examined its possible influence on oxidative stress, superoxide dismutase (SOD) activity, reduced glutathione (GSH) levels, and heat shock protein (HSP) 70 induction. CCH was induced by permanent bilateral common carotid artery occlusion in ovariectomized female rats. Extensive neuronal loss in the hippocampus at day 14 following CCH was observed. The ischemic changes were preceded by increases in malondialdehyde (MDA) concentration and HSP70 induction as well as reductions in GSH and SOD. Melatonin treatment restored the levels of MDA, SOD, GSH, and HSP70 induction as compared to the ischemic group. Histopathologic analysis confirmed the protective effect of melatonin against CCH‐induced morphologic alterations. Taken together, our results document that melatonin provides neuroprotective effects in CCH by attenuating oxidative stress and stress protein expression in neurons. This suggests melatonin may be helpful for the treatment of vascular dementia and cerebrovascular insufficiency.
The effect of rapid diagnostic testing for influenza on the reduction of antibiotic use in paediatric emergency department
Authors: Özkaya E , Cambaz N , Çoşkun Y , Mete F , Geyik M , Samancı N
Published: June 2009

Aim:  To determine the influence of rapid diagnosis of influenza on antibiotic prescribing to children presenting with influenza‐like illness in the emergency department in a inner city hospital in İstanbul, Turkey.

Methods:  Patients aged 3 to 14 years presenting to an urban children’s teaching hospital emergency department were screened for fever and cough, coryza, myalgias and/or malaise. After obtaining informed consent, patients were allocated into two groups. Group 1: patients were prescribed antibiotics after only physical examination; or Group 2: patients were prescribed antibiotics after rapid influenza testing. Nasopharyngeal swabs obtained from all patients were immediately tested in a single‐blind manner with Influenza A/B Rapid Test® for influenza A and B.

Results:  A total of 97 patients were enrolled, and 33 (34%) of these tested positive for influenza. Although frequency of positive results for influenza between the groups was similar (36% vs 32%, respectively), patients in Group 2 were less likely to be prescribed antibiotics when compared to those in Group 1 (32% vs 100%, respectively, p < 0.0001).

Conclusion:  Rapid diagnosis of influenza in the paediatric emergency department may allow a significant reduction in the over‐prescription of antibiotics.
Strategy for increasing detection rates of drug and alcohol abuse in paediatric emergency departments
Authors: Kozer E , Bar‐Hamburger R , Rosenfeld N , Dalal I , Landu O , Fainmesser P , Ben‐Yehuda Y , Berkovitch M
Published: June 2009

Aim:  To determine whether implementation of criteria for performing a toxicology screen and increasing staff awareness improve detection of substance abuse among adolescents presenting to the emergency department.

Methods:  Patients 12 to 18 years of age presenting to one of three emergency departments in Israel were included in a prospective cohort study. In the ‘study’ hospital, a set of criteria for urine toxicology screen and measurements of ethanol serum level were implemented. No specific interventions were implemented in the two other hospitals. The main outcome measure was the rate of substance abuse detection.

Results:  The number of adolescents seen in the participating centres was 3200 at the study hospital, and 3493 and 2792 at the two other hospitals. High blood ethanol concentrations were found in 49 patients at the study hospital compared with 30 and 19 patients at the two other hospitals (p < 0.001).

Illicit drugs were detected in 13, 4 and 1 patients, respectively (p = 0.002).

Conclusions:  Introducing structured guidelines for ordering toxicological screening increases the detection of alcohol and drug of abuse among adolescents presenting to paediatric emergency departments.
Ants accelerate succession from mountain grassland towards spruce forest
Authors: Vlasáková Blanka , Raabová Jana , Kyncl Tomáš , Dostál Petr , Kovářová Marcela , Kovář Pavel , Herben Tomáš
Published: June 2009

Question: What is the role of mound‐building ants (Lasius flavus) in successional changes of a grassland ecosystem towards a spruce forest?

Location: Slovenské Rudohorie Mountains, Slovakia; ca. 950 m a.s.l. near the Obrubovanec point (1020 m a.s.l.; 48°41′N, 19°39′E).

Methods: Both chronosequence data along a successional gradient and temporal data from long‐term permanent plots were collected on ants, spruce establishment, and vegetation structure, together with additional data on spruce growth.

Results: There are more spruce seedlings on ant mounds (4.72 m−2) than in the surrounding vegetation (0.81 m−2). Spruce seedlings grow faster on these mounds compared to surrounding areas. The first colonization wave of seedlings was rapid and probably occurred when grazing prevailed over mowing. Ant colony presence, mound volume, and plant species composition change along the successional gradient. Mounds become bigger when partly shaded but shrink in closed forest, when ant colonies disappear. Shade‐tolerant acidophylic species replace grassland plants both on the mounds and in surrounding areas.

Conclusions: The massive occurrence of Lasius flavus anthills contributes to a runaway feedback process that accelerates succession towards forest. The effect of ants as ecosystem engineers is scale‐dependent: although they stabilize the system at the scale of an individual mound, they may destabilize the whole grassland system over a longer time scale if combined with changes in mowing regime.
Insights into succession processes using temporally repeated habitat models: results from a long‐term study in a post‐mining landscape
Authors: Baasch Annett , Tischew Sabine , Bruelheide Helge
Published: June 2009

Questions: The early phases of primary succession are governed by chance events and dispersal‐related processes in an environment that is largely free of competition. Thus, the predictability of vegetation patterns using environmental site factors can be expected to be low and spatial autocorrelation to be high. We asked whether the match between vegetation and environment becomes better in the course of succession, and whether vegetation types shift their realized niche with time.

Location: Lignite mining region in Central Germany, the post‐mining landscape “Goitzsche” (Saxony‐Anhalt).

Methods: Vegetation types were mapped in a 10‐m grid (total area 4.8 ha), starting in 1995, at 3‐year intervals until 2007. We used a temporal comparison of habitat models. We applied: GLS regression to partition the variation in coverage of vegetation types into environmental (soil pH) and spatial components; logistic regression to model the presence/absence of vegetation types along a soil acidity gradient; and autologistic regression allowing for soil acidity and neighbourhood effects.

Results: For most vegetation types, the proportion of variation explained by space was high but declined during succession. The outcome of autologistic models suggests that soil acidity often plays a minor role compared to neighbourhood effects in the earlier phase of succession than 12 years later. For four vegetation types, the pH range in which the type was expected to be dominant clearly became smaller with time. These trends support the view that the role of processes related to chance and dispersal decrease with time, while those related to environmental filtering mediated by biotic interactions increase.

Conclusions: We conclude that temporal comparisons of spatially explicit habitat models provide insights into changing biotic community processes and their effects on habitat specificity of species or their communities. Thus, this approach may be particularly important for analysis of ecological systems that are not in equilibrium with their environmental drivers.
MAGNETIC RESONANCE IMAGING FINDINGS IN HORSES WITH RECENT ONSET NAVICULAR SYNDROME BUT WITHOUT RADIOGRAPHIC ABNORMALITIES
Authors: SAMPSON SARAH N. , SCHNEIDER ROBERT K. , GAVIN PATRICK R. , HO CHARLES P. , TUCKER RUSSELL L. , CHARLES ELIZABETH M.
Published: June 2009

Seventy‐two horses with recent onset of navicular syndrome and normal radiographs were assessed. Horses underwent magnetic resonance (MR) imaging of both front feet. All abnormalities were characterized and the most severe abnormality identified, if possible. Abnormal signal intensity in the navicular bone was the most severe abnormality in 24 (33%) horses. Pathologic change in the deep digital flexor tendon was the most severe abnormality in 13 (18%) horses. Pathologic change in the collateral sesamoidean ligament was the most severe abnormality in 11 (15%) horses. Pathologic change in the distal sesamoidean impar ligament was the most severe abnormality in seven (10%) horses. Multiple abnormalities were observed in 13 (18%) horses in which an abnormality that was more severe than the others could not be determined. Abnormalities were not observed in the navicular bone or its supporting soft tissues in four (5%) horses. Fifty‐six horses had abnormalities that were most severe in one limb; in 52 (93%) horses, the most severe abnormalities were in the foot of the most lame limb. In 7% (4/56) of horses, the most severe findings were in the opposite limb, and in 16 horses, the findings on both limbs were similar. MR imaging is a useful technique for evaluating horses with navicular syndrome and can differentiate between multiple abnormalities. This provides a more specific diagnosis which affects further treatment of the horse. Pathologic changes in different locations in the foot can cause similar clinical signs that, before MR imaging, were categorized as one syndrome.
DYNAMIC COMPUTED TOMOGRAPHY TO MEASURE TISSUE PERFUSION IN SPONTANEOUS CANINE TUMORS
Authors: NITZL DAGMAR , OHLERTH STEFANIE , MUELLER‐SCHWANDT FABIENNE , ANGST ANDREA , ROOS MALGORZATA , KASER‐HOTZ BARBARA
Published: June 2009

Dynamic computed tomography (CT) is widely used in humans to determine tumor perfusion via time–attenuation curves. Five types of time–attenuation curves have been identified and shown to have prognostic relevance in humans. The goal of our study was to assess the feasibility of this technology in spontaneous canine tumors and to determine time–attenuation curves and perfusion patterns in different tumor types. Thirty‐one dogs with tumors accessible for biopsy were evaluated (15 carcinomas, 16 sarcomas). Dynamic CT was performed at the level of the largest tumor cross‐section. Time–attenuation curves were calculated and ratios from the tumor to a contralateral artery were derived for wash‐in, peak attenuation, time to peak attenuation, wash‐out, and perfusion. Median perfusion was significantly higher and median time to peak ratio was significantly shorter in carcinomas and bone sarcomas compared with soft tissue sarcomas (P=0.03 and 0.01). There was a trend of lower median upslope and wash‐out ratio in soft tissue sarcomas in comparison with carcinomas (P=0.06 and 0.09). Although peak ratio was lowest in soft tissue sarcomas, differences were not significant (P=0.3). The most common type of time–attenuation curve for all tumors had a slow to moderately rapid wash‐in with a low to moderate attenuation peak followed by a plateau phase. In conclusion, dynamic CT is feasible and time‐activity curve‐derived measurements differed between spontaneous canine tumors. More data has to be collected in a larger number of patients and correlated with response to treatment and outcome.
MYELOGRAPHY VS. COMPUTED TOMOGRAPHY IN THE EVALUATION OF ACUTE THORACOLUMBAR INTERVERTEBRAL DISK EXTRUSION IN CHONDRODYSTROPHIC DOGS
Authors: HECHT SILKE , THOMAS WILLIAM B. , MARIONI‐HENRY KATIA , ECHANDI RITA L. , MATTHEWS ANDREA R. , ADAMS WILLIAM H.
Published: June 2009

Myelography and/or computed tomography (CT) are commonly used to evaluate acute intervertebral disk extrusion in chondrodystrophic dogs. The purpose of this study was to evaluate the sensitivity of myelography and two different CT protocols in determining level and lateralization of acute thoracolumbar intervertebral disk extrusion in comparison with surgical findings, investigate interobserver variability, and determine examination duration times. Results of conventional CT, helical CT, and myelography were compared with surgical findings in 19 chondrodystrophic dogs with acute thoracolumbar intervertebral disk extrusion. Agreement among investigators was determined for different imaging modalities, and examination times were recorded. In the diagnosis of level of disk extrusion there was agreement of myelography, conventional CT, and helical CT with surgical findings in 94.7%, 100%, and 94.7% of dogs, respectively (P=0.144). In the diagnosis of level and lateralization of disk extrusion there was agreement of myelography, conventional CT, and helical CT with surgical findings in 78.9%, 87.4%, and 85.3% of dogs, respectively (P=0.328). Interobserver agreement was very good for all imaging modalities (myelography κ=0.87; conventional CT κ=0.86; helical CT κ=0.95). There were significant differences in median examination duration times between helical CT (4 min), conventional CT (8 min), and myelography (32 min) (P<0.001). Both helical and conventional CT appear to be accurate for evaluation of acute thoracolumbar intervertebral disk extrusion in chondrodystrophic dogs and are faster to perform than myelography.
ASSOCIATIONS BETWEEN CARDIOPULMONARY VARIABLES AND THE CEREBROSPINAL FLUID SIGNAL‐VOID SIGN IN SMALL‐BREED DOGS
Authors: FREER SEAN R. , SCRIVANI PETER V. , ERB HOLLIS N.
Published: June 2009

The cerebrospinal fluid (CSF) signal‐void sign is a CSF signal loss, especially on T2‐weighted magnetic resonance (MR) images. The CSF signal‐void sign is often seen in small dogs with hydrocephalus and syringomyelia. In people, this sign is attributed to high velocity or turbulent CSF flow resulting from normal arterial pulsations, but is more pronounced in hydrocephalic patients with reduced intracranial compliance. If dogs are similar, then detection of this sign might be influenced by cardiovascular variables affected by anesthesia or related to intracranial compliance (e.g., blood pressure) or that affect CSF flow (e.g., heart rate). Therefore, the purpose of this study was to investigate whether the CSF signal‐void sign is associated with these cardiovascular variables. The sample population consisted of 53 small‐breed (<15 kg) anesthetized dogs undergoing spin echo, T2‐weighted MR imaging of the neurocranium. Heart rate, blood pressure (systolic, mean, diastolic, pulse), and end‐tidal CO2 were recorded and dogs were grouped as having a CSF signal‐void sign in the mesencephalic aqueduct (19/53) or not (34/53). Normality was confirmed and t‐tests used. No statistical difference was detected between groups for any of the cardiovascular variables. However, the sample size was too small to accept the null hypothesis that no difference existed between groups for any of the variables assessed. Therefore, although it is uncertain whether the investigated variables alter the frequency of detecting a CSF signal‐void sign, any possible relationship does not appear strong.
DISTAL ABDOMINAL AORTIC THROMBOSIS DIAGNOSED BY THREE‐DIMENSIONAL CONTRAST‐ENHANCED MAGNETIC RESONANCE ANGIOGRAPHY
Authors: SHARPLEY JENELLE , THODE HANK , SESTINA LISBETH , PARK RICHARD , MONNET ERIC , KRAFT SUSAN L.
Published: June 2009

Contrast enhanced magnetic resonance angiography (MRA) can provide noninvasive relatively rapid three‐dimensional high‐detailed vascular images over large anatomic areas. There are few descriptions of the use of contrast‐enhanced MRA in veterinary patients. This is a report illustrating the use of contrast‐enhanced MRA to localize the full extent of distal aortic, external iliac, and femoral artery thrombi confirmed surgically in four dogs. Distal aorta contrast‐enhanced MRA was anatomically accurate in detecting the full extent of thrombi involving the aorta, external iliac and femoral arteries in these four canine patients. This procedure can provide important information for surgery.
INTRAHEPATIC VENOUS COLLATERALS PREVENTING SUCCESSFUL STENT‐SUPPORTED COIL EMBOLIZATION OF INTRAHEPATIC SHUNTS IN DOGS
Authors: SCHNEIDER MATTHIAS , PLASSMANN MADELEINE , RAUBER KLAUS
Published: June 2009

The purpose of the following study was to evaluate stent‐supported coil embolization of the hepatic vein in combination with antithrombotic treatment as a method for treatment of intrahepatic shunts, and to describe the complications associated with this procedure. Seven dogs with an intrahepatic shunt were included in a prospective clinical trial. A stepwise procedure was performed. First intervention: transjugular retrograde portography and stent implantation into caudal vena cava; second intervention: hepatic vein embolization combined with an antithrombotic treatment; third intervention in dogs with residual shunting: hepatic vein embolization without antithrombotic treatment. A right shunt was found in one dog and a left shunt in six dogs. Primary intrahepatic venous collaterals were found in one dog and hepatic vein embolization was not performed. Stent implantation into the caudal vena cava was performed in the other six dogs. There was no stent migration or thrombosis. Following the first coil intervention two dogs died due to vessel laceration while removing an oversized or migrated coil. On follow‐up the shunt was completely closed in one dog. Secondary intrahepatic venous collaterals developed after the first or second coil intervention in two and one dog, respectively. In conclusion, stent‐supported coil embolization of the hepatic vein in combination with an antithrombotic treatment was of limited success because primary or secondary intrahepatic venous collaterals tend to occur.
A COMPLEMENTARY RADIOGRAPHIC PROJECTION OF THE EQUINE TEMPOROMANDIBULAR JOINT
Authors: EBLING ALESSIA J. , MCKNIGHT ALEXIA L. , SEILER GABRIELA , KIRCHER PATRICK R.
Published: June 2009

The complexity of the equine skull makes the temporomandibular joint a difficult area to evaluate radiographically. The goal of this study was to determine the optimal angle for a complementary radiographic projection of the equine temporomandibular joint based on a computed tomography (CT) cadaver study. CT was performed on six equine cadaver heads of horses that were euthanized for other reasons than temporomandibular joint disease. After the CT examination, 3D reconstruction of the equine skull was performed to subjectively determine the angle for a complementary radiographic projection of the temporomandibular joint. The angle was measured on the left and right temporomandibular joint of each head. Based on the measurements obtained from the CT images, a radiographic projection of the temporomandibular joint in a rostral45°ventral‐caudodorsal oblique (R45°V‐CdDO) direction was developed by placing the X‐ray unit 30° laterally, maintaining at the same time the R45°V‐CdDO angle (R45°V30°L‐CdDLO). This radiographic projection was applied to all cadaver heads and on six live horses. In three of the live horses abnormal findings associated with the temporomandibular joint were detected. We conclude that this new radiographic projection of the temporomandibular joint provides superior visualization of the temporomandibular joint space and the articular surface of the mandibular condyle.
MAGNETIC RESONANCE IMAGING ANATOMY OF THE NORMAL EQUINE LARYNX AND PHARYNX
Authors: PEKARKOVA MARTA , KIRCHER PATRICK R. , KONAR MARTIN , LANG JOHANN , TESSIER CAROLINE
Published: June 2009

The purpose of the present study was to describe normal magnetic resonance (MR) imaging anatomy of the equine larynx and pharynx and to present the optimal protocol, sequences, and possible limitations of this examination technique. Using a 0.3 T unit, the laryngeal and pharyngeal regions was imaged in two horses. The protocol consisted of sagittal and transverse T2‐weighted (T2w) fast spin echo, transverse T1‐weighted (T1w) spin echo, and dorsal high‐resolution T1w gradient echo (both pre‐ and postcontrast enhancement) sequences. Euthanasia was performed at the end of the imaging procedure. Macroscopic anatomy of the cadaver sections were compared with the MR images in transverse, midsagittal, and parasagittal planes. There was good differentiation of anatomic structures, including soft tissues. The laryngeal cartilages, hyoid apparatus, and upper airway muscle groups with their attachments could be clearly identified. However, it was not always possible to delineate individual muscles in each plane. Most useful were both T2w and T1w transverse sequences. Intravenous application of contrast medium was helpful to identify blood vessels. The MR images corresponded with the macroscopic anatomy of cadaver sections.
IMAGING DIAGNOSIS—NECROTIZING MENINGOMYELITIS AND POLYARTHRITIS
Authors: PARRY ANDREW T. , PENNING VICTORIA A. , SMITH KEN C. , KENNY PATRICK J. , LAMB CHRISTOPHER R.
Published: June 2009

A vaccinated 2‐year‐old female neutered Weimaraner had bilateral pelvic limb ataxia that progressed over 12 h. The dog became nonambulatory, with signs of pain on palpation of the lumbar spine. The dog also developed multiple joint effusions. On magnetic resonance (MR) imaging, there was a diffuse, asymmetric T2‐hyperintensity in the thoracolumbar spinal cord which was characterized by contrast enhancement. Lumbar cerebrospinal fluid (CSF) analysis had an elevated white blood cell count and protein. On the basis of MR images and CSF analysis, a presumptive diagnosis of diffuse myelitis was made. The dog became paraplegic and was euthanized. Postmortem examination confirmed the presence of myelitis with vasculitis and nonerosive polyarthritis.
ULTRASONOGRAPHIC DIAGNOSIS OF COXOFEMORAL SUBLUXATION IN HORSES
Authors: BRENNER SUZANNE , WHITCOMB MARY BETH
Published: June 2009

The clinical and ultrasonographic features of seven horses with coxofemoral subluxation are presented. Affected horses included five adult geldings (11–20 years), one large pony (6 years) and a 3‐month‐old filly. All were lame at the walk except for the pony with grade 3/5 lameness. Lameness was acute in all horses, but three horses progressed after initial improvement. Crepitus, muscle atrophy, and pelvic asymmetry were inconsistent findings. Ultrasonographic diagnosis of subluxation required dynamic visualization of femoral head displacement from the acetabulum while placing weight on the affected limb and subsequent replacement into its normal position upon limb resting. Acetabular rim fractures and joint effusion were visible regardless of weight bearing status in six horses each. No fractures were identified in the pony; the only patient with a good outcome. Six horses had a poor outcome with severe chronic lameness, four of which were euthanized. Postmortem ventrodorsal radiographs obtained in two horses confirmed subluxation only on extended limb projections, but not on hip‐flexed projections. Acetabular rim fractures were not visible radiographically in either horse but were confirmed at necropsy. Subluxation was due to an elongated but intact ligament of the head of the femur in both horses. Osteoarthrosis was evident ultrasonographically, radiographically, and at necropsy. Dynamic ultrasonography was readily performed in the standing horse and produced diagnostic images with a low frequency curvilinear transducer. The apparent poor prognosis for horses with subluxation and acetabular fracture illustrate the importance of this imaging technique to identify affected horses.
Supervisor–Subordinate Guanxi: Developing a Three-Dimensional Model and Scale
Authors: Chen Ying , Friedman Ray , Yu Enhai , Fang Weihua , Lu Xinping
Published: June 2009

We develop a three-dimensional concept of supervisor-subordinate guanxi. This concept includes affective attachment, personal-life inclusion, and deference to supervisor. Based on this concept, we conducted three studies to develop and validate a three-dimensional supervisor-subordinate guanxi measure and to examine its relationship with related constructs, such as leader-member exchange. Results from Study 1 and Study 2 provide evidence of convergent and discriminant validity of the scale, while Study 3 demonstrates the scale's incremental validity and replicates results from Study 2. Furthermore, in Study 3, we found that the three dimensions of supervisor-subordinate guanxi had different significant effects on commitment, turnover intention, and procedural justice, providing further evidence of criterion-related validity. Overall, these empirical results provide support for our three-dimensional model of supervisor-subordinate guanxi.
Screening of edentulous patients in a dental school population using the prosthodontic diagnostic index
Authors: Ntala Polyxeni Chr. , Niarchou Artemis P. , Polyzois Gregory L. , Frangou Maria J.
Published: June 2009

doi:10.1111/j.1741‐2358.2009.00317.x
 
Screening of edentulous patients in a dental school population using the prosthodontic diagnostic index

Purpose:  The aim of this study was to classify a number of completely or partially edentulous patients who attended undergraduate clinics at the Dental School of Athens using the prosthodontic diagnostic index (PDI) to identify the complexity of the cases treated by the students.

Background:  There is a scarcity of studies, concerning prosthodontic patients and screening them according to a classification system such as the PDI.

Material and methods:  The survey was conducted on 181 patients who attended the clinics for treatment. The PDI categorised the patients into four classes (Class I–IV) according to the severity of certain diagnostic findings.

Results:  From the 110 completely edentulous patients, 27 patients were in Class I, 21 in Class II, 15 in Class III and 47 in Class IV. From the 71 partially edentulous patients, two were in Class I, 17 in Class II, 29 in Class III and 23 in Class IV.

Conclusion:  Our results showed that the majority of patients were categorised in Class III (partially edentulous) and IV (completely edentulous). This indicates the need to introduce a proper screening tool, such as the PDIs, during the initial examination, to achieve a successful treatment.
An overview of osteoporosis for the practising prosthodontist
Authors: Singh Saumyendra V. , Tripathi Arvind
Published: June 2009

doi:10.1111/j.1741‐2358.2009.00324.x
 
An overview of osteoporosis for the practising prosthodontist

Osteoporosis is an insidious and common bone disorder of the modern age, as a result of the rapidly increasing number of older people in the total population. It has long been concluded that this disease has definite deleterious effects on the stomatognathic system and is therefore of major concern to a Prosthodontist. If features on a dental radiograph, which are the most commonly required radiographs, can be detected regularly and consistently, it would place a prosthodontist in a position to refer the patient for timely management and also modify his treatment plan, greatly improving the prognosis. Available literature was therefore reviewed for pathophysiology, dental radiographic screening measures, implications and management of osteoporosis from the perspective of a prosthodontist.