bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of endodontic sealer cement on fibreglass post bond strength to root dentine
Authors: Menezes M. S. , Queiroz E. C. , Campos R. E. , Martins L. R. M. , Soares C. J.
Published: March 2008

Aim  To test the hypothesis that the composition of endodontic sealer cements and the time elapsed between root filling and fibreglass post fixation interferes with adhesion to root canal dentine.

Methodology  Sixty bovine incisor roots were divided into five groups (n = 12): CI, unfilled; SI, filled with a calcium hydroxide‐based cement‐Sealer 26, and immediate post fixation; S7, Sealer 26 and post fixation after 7 days; EI, filled with a zinc oxide and eugenol‐based cement‐Endofill and immediate fixation; and E7 Endofill and post fixation after 7 days. The posts were cemented with adhesive system and dual resin cement. Ten roots were cross‐sectioned to obtain two 1‐mm‐thick discs for each cervical (TC), middle (TM) and apical (TA) third of the prepared root portion. The posts were submitted to a micropush‐out test. The other two teeth were evaluated using scanning electron microscopy to analyse the bond interface. Data were analysed using anova, Tukey and Dunnett tests (P < 0.05).

Results  Group EI was associated with a significant reduction in bond strength values irrespective of the root region; TC = 3.50 MPa (P = 0.0001); TM = 2.22 MPa (P = 0.0043) and TA = 1.45 MPa (P = 0.003). Region of canal had an influence on the values for the cement used in group E7, in which only the TA presented differences from the CI.

Conclusions  Endofill interfered negatively with the bond to root dentine along its full length and in the TA when post fixation was delayed for 7 days. Bond strength decreased from crown to apex in all groups.
Ethical sensitivity in professional practice: concept analysis
Authors: Weaver Kathryn , Morse Janice , Mitcham Carl
Published: March 2008

Title.  Ethical sensitivity in professional practice: concept analysis

Aim.  This paper is a report of a concept analysis of ethical sensitivity.

Background.  Ethical sensitivity enables nurses and other professionals to respond morally to the suffering and vulnerability of those receiving professional care and services. Because of its significance to nursing and other professional practices, ethical sensitivity deserves more focused analysis.

Data sources.  A criteria‐based method oriented toward pragmatic utility guided the analysis of 200 papers and books from the fields of nursing, medicine, psychology, dentistry, clinical ethics, theology, education, law, accounting or business, journalism, philosophy, political and social sciences and women’s studies. This literature spanned 1970 to 2006 and was sorted by discipline and concept dimensions and examined for concept structure and use across various contexts. The analysis was completed in September 2007.

Findings.  Ethical sensitivity in professional practice develops in contexts of uncertainty, client suffering and vulnerability, and through relationships characterized by receptivity, responsiveness and courage on the part of professionals. Essential attributes of ethical sensitivity are identified as moral perception, affectivity and dividing loyalties. Outcomes include integrity preserving decision‐making, comfort and well‐being, learning and professional transcendence. Our findings promote ethical sensitivity as a type of practical wisdom that pursues client comfort and professional satisfaction with care delivery.

Conclusion.  The analysis and resulting model offers an inclusive view of ethical sensitivity that addresses some of the limitations with prior conceptualizations.
Hierarchical Bayes estimation of species richness and occupancy in spatially replicated surveys
Authors: Kéry M. , Royle J. A.
Published: March 2008

Species richness is the most widely used biodiversity metric, but cannot be observed directly as, typically, some species are overlooked. Imperfect detectability must therefore be accounted for to obtain unbiased species‐richness estimates. When richness is assessed at multiple sites, two approaches can be used to estimate species richness: either estimating for each site separately, or pooling all samples. The first approach produces imprecise estimates, while the second loses site‐specific information.

In contrast, a hierarchical Bayes (HB) multispecies site‐occupancy model benefits from the combination of information across sites without losing site‐specific information and also yields occupancy estimates for each species. The heart of the model is an estimate of the incompletely observed presence–absence matrix, a centrepiece of biogeography and monitoring studies. We illustrate the model using Swiss breeding bird survey data, and compare its estimates with the widely used jackknife species‐richness estimator and raw species counts.

Two independent observers each conducted three surveys in 26 1‐km2 quadrats, and detected 27–56 (total 103) species. The average estimated proportion of species detected after three surveys was 0·87 under the HB model. Jackknife estimates were less precise (less repeatable between observers) than raw counts, but HB estimates were as repeatable as raw counts. The combination of information in the HB model thus resulted in species‐richness estimates presumably at least as unbiased as previous approaches that correct for detectability, but without costs in precision relative to uncorrected, biased species counts.

Total species richness in the entire region sampled was estimated at 113·1 (CI 106–123); species detectability ranged from 0·08 to 0·99, illustrating very heterogeneous species detectability; and species occupancy was 0·06–0·96. Even after six surveys, absolute bias in observed occupancy was estimated at up to 0·40.

Synthesis and applications. The HB model for species‐richness estimation combines information across sites and enjoys more precise, and presumably less biased, estimates than previous approaches. It also yields estimates of several measures of community size and composition. Covariates for occupancy and detectability can be included. We believe it has considerable potential for monitoring programmes as well as in biogeography and community ecology.
Niche overlap between marsupial and eutherian carnivores: does competition threaten the endangered spotted‐tailed quoll?
Authors: Glen A. S. , Dickman C. R.
Published: March 2008

The significance of top‐down regulation by carnivores is receiving increasing global recognition. As a consequence, key objectives in many programmes that seek to maintain ecosystem function now include conserving carnivores and understanding their interactions. This study examined overlap in resource use (space and diet) of introduced eutherian carnivores and an endangered marsupial carnivore, the spotted‐tailed quoll Dasyurus maculatus, in eastern Australia. We also investigated mechanisms of niche partitioning and evidence for interspecific aggression.

Dietary overlap between quolls, red foxes Vulpes vulpes and wild dogs Canis lupus ssp. was assessed by analysis of scats. Trapping, radio‐tracking and direct observations were used to quantify spatial overlap between quolls, foxes, wild dogs and feral cats Felis catus.

Dietary overlap among the carnivores was extensive. Medium‐sized mammals were the most important prey for all three predators, indicating potential for exploitative interactions. However, hunting of different size classes of secondary prey and consumption by quolls of more arboreal prey than their counterparts may assist coexistence. Remains of quoll were found in two dog scats, and cat hair in another, possibly indicating intraguild predation.

We observed extensive spatial overlap between quolls and eutherian carnivores. However, we inferred from dietary data that quolls foraged primarily in forested habitat, while canids foraged mainly in cleared habitat.

Synthesis and applications. Our results indicate strong potential for competition between spotted‐tailed quolls and eutherian carnivores, and thus a situation where control of introduced predators may be desirable, not only for the conservation of prey species but also for the protection of native carnivores. Concern over potential non‐target mortality of quolls has hindered efforts to control foxes in eastern Australia using poison baits. We contend that, rather than harming quoll populations, baiting for foxes should aid the conservation of quolls and should be implemented in areas of sympatry where fox numbers are high.
Characterization of Proteinases Excreted by Bacillus subtilis Marburg Strain during Sporulation
Authors: Millet Jacqueline
Published: March 2008

Summary. This study has characterized 3 proteolytic enzymes during sporulation by Bacillus subtilis Marburg strain when grown in nutrient broth. A method of purification is described which permits the separation of 2 different proteinases: one belonging to the metal enzyme group and the other to the serine enzyme group. The third enzyme, probably an esterase, showed a high esterolytic activity, but only low proteolytic activity. Determination of the 3 enzymes in a mixture was accomplished by using specific substrates and inhibitors. They were excreted simultaneously between the end of the growth phase until the appearance of the prespores. During this entire period, 20% of the total proteolytic activity was due to the metal proteinase; 80% of the proteolytic activity and 15% of the esterolytic activity was due to the serine proteinase; 85% of the esterolytic activity was the result of the esterase. These findings will contribute to a more complete phenotypic characterization of those mutants of sporulation that appear to be involved in the production of extracellular hydrolytic enzymes.
Research priorities in nursing – a Delphi study among Swedish nurses
Authors: Bäck‐Pettersson Siv , Hermansson Evelyn , Sernert Ninni , Björkelund Cecilia
Published: March 2008

Aims and objectives.  The main aim was to illuminate essential areas for future patient‐related nursing research. The secondary aim was to stimulate nurses to explore important research areas based on clinical practice.

Background.  Priority‐setting is regarded as one of the main strategies to ensure excellence in nursing science, to direct nursing research and develop healthcare practice accordingly as well as strengthening the nursing profession's research commitment.

Design and method.  A three‐round Delphi survey was conducted. A panel of 118 clinicians, in various nursing, teaching and administrative positions participated. Ninety‐five panel members completed all three rounds (81%). The majority were female, aged 25–67 (mean 49) years, with an average of 23 (range 1–40) years in nursing, working in hospitals (42%), primary healthcare centres, community care (44%) and administration/education (14%). Sixty‐six per cent had graduate diplomas and 34% had an academic education, ranging from bachelors’ to doctoral degrees.

Results.  Three hundred and eighty nursing research areas were identified, evaluated and ranked using content analysis and descriptive statistics. The participants’ prioritised research aimed at preserving humanistic values and developing cross‐organisational collaboration in the healthcare system. Nursing research aimed at preserving human dignity in geriatric care, respectful transfers, continuity of care and exploring the characteristics of a caring encounter were ranked high relative to the patient welfare, to the healthcare organisation and to the nursing profession.

Conclusions.  Nurses prioritise research that will improve clinical practice, assure patients’ wellbeing and a caring environment. Nurses can reach consensus on the objectives of patient‐related nursing research despite differences in age, workplace, educational period and level of academic degree.

Relevance to clinical practice.  When prioritising important areas for patient‐related nursing research, informed nursing practitioners’ commitment initiates knowledge development within clinical practice from a nursing science perspective as well as expanding cross‐professional and cross‐organisational collaboration.
Fight or flight: antipredator strategies of baleen whales
Authors: FORD JOHN K. B. , REEVES RANDALL R.
Published: March 2008

The significance of killer whaleOrcinus orcapredation on baleen whales (Mysticeti) has been a topic of considerable discussion and debate in recent years. Discourse has been constrained by poor understanding of predator‐prey dynamics, including the relative vulnerability of different mysticete species and age classes to killer whales and how these prey animals avoid predation. Here we provide an overview and analysis of predatory interactions between killer whales and mysticetes, with an emphasis on patterns of antipredator responses.

Responses of baleen whales to predatory advances and attacks by killer whales appear to fall into two distinct categories, which we term thefightandflightstrategies. Thefightstrategy consists of active physical defence, including self‐defence by single individuals, defence of calves by their mothers and coordinated defence by groups of whales. It is documented for five mysticetes: southern right whaleEubalaena australis, North Atlantic right whaleEubalaena glacialis, bowhead whaleBalaena mysticetus, humpback whaleMegaptera novaeangliaeand grey whaleEschrichtius robustus. Theflightstrategy consists of rapid (20–40 km/h) directional swimming away from killer whales and, if overtaken and attacked, individuals do little to defend themselves. This strategy is documented for six species in the genusBalaenoptera.

Many aspects of the life history, behaviour and morphology of mysticetes are consistent with their antipredator strategy, and we propose that evolution of these traits has been shaped by selection for reduced predation.Fightspecies tend to have robust body shapes and are slow but relatively manoeuvrable swimmers. They often calve or migrate in coastal areas where proximity to shallow water provides refuge and an advantage in defence. Mostfightspecies have either callosities (rough and hardened patches of skin) or encrustations of barnacles on their bodies, which may serve (either primarily or secondarily) as weapons or armour for defence.Flightspecies have streamlined body shapes for high‐speed swimming and they can sustain speeds necessary to outrun pursuing killer whales (>15–20 km/h). These species tend to favour pelagic habitats and calving grounds where prolonged escape sprints from killer whales are possible.

The rarity of observed successful attacks by killer whales on baleen whales, especially adults, may be an indication of the effectiveness of these antipredator strategies. Baleen whales likely offer low profitability to killer whales, relative to some other marine mammal prey. High‐speed pursuit offlightspecies has a high energetic cost and a low probability of success while attacks onfightspecies can involve prolonged handling times and a risk of serious injury.
Anthropogenic causes of the western Steller sea lion Eumetopias jubatus population decline and their threat to recovery
Authors: ATKINSON SHANNON , DEMASTER DOUGLAS P. , CALKINS DONALD G.
Published: March 2008

The western Steller sea lion Eumetopias jubatus population has experienced a chronic decline since the 1960s. The causes are likely multifactorial and a combination of anthropogenic and natural factors. A draft revised recovery plan for the Steller sea lion has been published by the US National Marine Fisheries Service, listing both anthropogenic and natural factors that may have contributed to the observed decline or which may be a threat to the recovery of the western Steller sea lion population. The purpose of this review is to consider the anthropogenic threats to this stock.

Anthropogenic sources of mortality include fisheries competition resulting in nutritional stress, mortality incidental to commercial fisheries (i.e. fisheries by‐catch), subsistence hunts, legal and illegal shooting, commercial hunts, anthropogenic‐related contamination, and research‐induced mortalities.

We present evidence that the following anthropogenic factors likely contributed to the decline of the western Steller sea lion population over the last 40 years: (i) mortality incidental to commercial fisheries (i.e. by‐catch); (ii) commercial hunting of western Steller sea lions; and (iii) legal and illegal shooting; whereas the subsistence hunts for western Steller sea lions and mortality incidental to research were not likely to be contributors to the observed decline.

Further, we present evidence that the following can be excluded as significant anthropogenic threats to the recovery of the western Steller sea lion population: (i) mortality incidental to commercial fishing; (ii) legal and illegal shooting; (iii) commercial hunts of Steller sea lions; (iv) subsistence hunting; and (v) mortality incidental to research.

Competition with fisheries resulting in nutritional stress, and the potential impacts of contaminants, are two anthropogenic factors that should continue to be a priority for the various organizations currently doing research on this population.
A widespread riboswitch candidate that controls bacterial genes involved in molybdenum cofactor and tungsten cofactor metabolism
Authors: Regulski Elizabeth E. , Moy Ryan H. , Weinberg Zasha , Barrick Jeffrey E. , Yao Zizhen , Ruzzo Walter L. , Breaker Ronald R.
Published: March 2008

We have identified a highly conserved RNA motif located upstream of genes encoding molybdate transporters, molybdenum cofactor (Moco) biosynthesis enzymes, and proteins that utilize Moco as a coenzyme. Bioinformatics searches have identified 176 representatives in γ‐Proteobacteria, δ‐Proteobacteria, Clostridia, Actinobacteria, Deinococcus‐Thermus species and DNAs from environmental samples. Using genetic assays, we demonstrate that a Moco RNA in Escherichia coli associated with the Moco biosynthetic operon controls gene expression in response to Moco production. In addition, we provide evidence indicating that this conserved RNA discriminates against closely related analogues of Moco. These results, together with extensive phylogenetic conservation and typical gene control structures near some examples, indicate that representatives of this structured RNA represent a novel class of riboswitches that sense Moco. Furthermore, we identify variants of this RNA that are likely to be triggered by the related tungsten cofactor (Tuco), which carries tungsten in place of molybdenum as the metal constituent.
Hysteretic and graded responses in bacterial two‐component signal transduction
Authors: Igoshin Oleg A. , Alves Rui , Savageau Michael A.
Published: March 2008

Bacterial two‐component systems (TCS) are key signal transduction networks regulating global responses to environmental change. Environmental signals may modulate the phosphorylation state of sensor kinases (SK). The phosphorylated SK transfers the phosphate to its cognate response regulator (RR), which causes physiological response to the signal. Frequently, the SK is bifunctional and, when unphosphorylated, it is also capable of dephosphorylating the RR. The phosphatase activity may also be modulated by environmental signals. Using the EnvZ/OmpR system as an example, we constructed mathematical models to examine the steady‐state and kinetic properties of the network. Mathematical modelling reveals that the TCS can show bistable behaviour for a given range of parameter values if unphosphorylated SK and RR form a dead‐end complex that prevents SK autophosphorylation. Additionally, for bistability to exist the major dephosphorylation flux of the RR must not depend on the unphosphorylated SK. Structural modelling and published affinity studies suggest that the unphosphorylated SK EnvZ and the RR OmpR form a dead‐end complex. However, bistability is not possible because the dephosphorylation of OmpR∼P is mainly done by unphosphorylated EnvZ. The implications of this potential bistability in the design of the EnvZ/OmpR network and other TCS are discussed.
Rapid in vitro microindexing of viroids in citrus
Authors: Kapari‐Isaia T. , Kyriakou A. , Papayiannis L. , Tsaltas D. , Gregoriou S. , Psaltis I.
Published: March 2008

A new laboratory technique combining shoot‐tip grafting in vitro and biological indexing on indicator plants was explored for the detection of citrus exocortis and related viroids. Τhree in vitro laboratory methods were used and compared with the classical biological method. With the classical in vivo method, diagnosis is based on the expression of symptoms on indicators 11–14 weeks after inoculation. In contrast, with the first in vitro method, microindexing in vitro of citron seedlings by graft inoculation, diagnosis was possible 12 days after inoculation; with the second method, microindexing in vitro of citron cuttings by graft inoculation, 20 days after inoculation; and with the third method, microindexing in vitro of citron cuttings by injection inoculation, 40 days after inoculation. Inoculated Etrog citron plantlets grown in vitro and tested by RT‐PCR showed the same viroid content as the source plants. Of the three in vitro viroid indexing methods, microindexing on cuttings by grafting was easier and more reliable than microindexing either on seedlings or on cuttings by injection.
Ferritin is required for rapid remodeling of the photosynthetic apparatus and minimizes photo‐oxidative stress in response to iron availability in Chlamydomonas reinhardtii
Authors: Busch Andreas , Rimbauld Blandine , Naumann Bianca , Rensch Stefan , Hippler Michael
Published: March 2008

Ferritin is a key player in the iron homeostasis due to its ability to store large quantities of iron. Chlamydomonas reinhardtii contains two nuclear genes for ferritin (ferr1 and ferr2) that are induced when Chlamydomonas cells are shifted to iron‐deficient conditions. In response to the reduced iron availability, degradation of photosystem I (PSI) and remodeling of its light‐harvesting complex occur. This active PSI degradation slows down under photo‐autotrophic conditions where photosynthesis is indispensable. We observed a strong induction of ferritin correlated with the degree of PSI degradation during iron deficiency. The PSI level can be restored to normal within 24 h after iron repletion at the expense of the accumulated ferritin, indicating that the ferritin‐stored iron allows fast adjustment of the photosynthetic apparatus with respect to iron availability. RNAi strains that are significantly reduced in the amount of ferritin show a striking delay in the degradation of PSI under iron deficiency. Furthermore, these strains are more susceptible to photo‐oxidative stress under high‐light conditions. We conclude that (i) ferritin is used to buffer the iron released by degradation of the photosynthetic complexes, (ii) the physiological status of the cell determines the strategy used to overcome the impact of iron deficiency, (iii) the availability of ferritin is important for rapid degradation of PSI under iron deficiency, and (iv) ferritin plays a protective role under photo‐oxidative stress conditions.
Structural analysis and haplotype diversity in swine LEP and MC4R genes
Authors: D'Andrea M. , Pilla F. , Giuffra E. , Waddington D. , Archibald A.L.
Published: March 2008

Knowledge about structural variation of candidate genes could be important to improve breeding selection scheme and preserve genetic variability in livestock species. Leptin (LEP) and melanocortin‐4 receptor (MC4R) genes are involved in the energetic pathway and are obvious candidate genes for fatness. By sequencing LEP and MC4R genes in 72 pigs belonging to lean (Large White and Duroc), fat (Meishan and Casertana) breeds and also Wild Boar, 98 polymorphic sites, of which 91 were novel, were found in the Leptin sequence while only the previously described mutation was found in the MC4R gene. A total of 18 LEP haplotypes were observed and their distribution was unequal among the breeds. The phylogenetic analysis showed two haplotype branches distinguishing between lean and fat breeds.
Effect of parental genotypes and paternal heterosis on litter traits in crossbred goats
Authors: Tsukahara Y. , Choumei Y. , Oishi K. , Kumagai H. , Kahi A.K. , Panandam J.M. , Mukherjee T.K. , Hirooka H.
Published: March 2008

The effect of parental genotype and paternal heterosis on litter size (LS), total litter birth weight (TLW) and average litter birth weight (ALW) was analysed utilizing data from a crossbreeding programme involving the exotic German Fawn goats and local Katjang goats in Malaysia. In this study, these traits were regarded as traits of the litter to consider the effect of service sire genotype. The results revealed that LS was significantly influenced by the genotype of sire. The genotypes of sire and dam had significant effects on TLW and ALW. Estimates of crossbreeding parameter showed significant and negative influence of paternal heterosis on TLW and ALW while there was no significant effect of paternal heterosis on LS. The results of this study stress the need to reconsider the use of local males in the tropics.
Association analysis of the constructed linkage maps covering TLR2 and TLR4 with clinical mastitis in Norwegian Red cattle
Authors: Opsal M.A. , Lien S. , Brenna‐Hansen S. , Olsen H.G. , Våge D.I.
Published: March 2008

Toll‐like receptors (TLR) are important cell‐surface molecules mediating immune responses. Previous studies have identified TLR2 and TLR4 as potential candidate genes for disease resistance. In this study, dense linkage maps comprising single nucleotide polymorphisms (SNPs) have been constructed for the chromosomal regions harbouring TLR2 and TLR4 on bovine chromosome 17 and 8. The most likely marker orders for both regions were compared with the corresponding human map positions and used to reorder bovine scaffolds available from the bovine genome sequence assembly (Btau_3.1). A combined linkage and linkage disequilibrium method was used to investigate possible associations between the TLR genes and mastitis susceptibility recorded in the Norwegian Red cattle population. The analysis did not detect any significant association between the chromosomal regions surrounding TLR2 and TLR4 and mastitis in Norwegian Red cattle.
In vivo confocal microscopy in a patient with conjunctival amyloidosis
Authors: Bozkurt Banu , Kiratli Hayyam , Soylemezoglu Figen , Irkec Murat
Published: March 2008

Abstract

Conjunctival amyloidosis is a rare clinical entity. We herein reported in vivo confocal microscopic features of conjunctival amyloidosis and correlated the results with the histopathological findings. Histopathological examination of the biopsy specimen revealed acellular, amorphous, eosinophilic material in the substantia propria of the conjunctiva and positive staining with Congo red confirmed that the material was amyloid. Confocal microscopy with Heidelberg Retina Tomograph II Rostock Cornea Module showed hyporeflective material deposited in a lobular pattern in the substantia propria and around the blood vessels. The material seemed acellular and no inflammatory or dendriform cell accumulation was noted within or around the lesion. Further studies should be done to understand the confocal characteristics of the conjunctival diseases and find specific clues for the diagnosis.
The one‐eye trial and fellow eye response to prostaglandin analogues
Authors: Dayanir Volkan , Cakmak Harun , Berkit Ilker
Published: March 2008

Abstract

Background:  To determine if the intraocular pressure (IOP) reduction in one‐eye trial correlates with the IOP reduction in the fellow eye when IOP variability during office hours is taken into account.

Methods:  This retrospective observational case series includes 50 high tension (primary open‐angle glaucoma, exfoliative glaucoma and ocular hypertension; Group 1) and 21 normal tension (Group 2) glaucoma patients. Charts of bilateral open‐angle glaucoma patients at Glaucoma Unit, School of Medicine, Adnan Menderes University who had pretreatment baseline office IOP measurements at 9:30, 11:30 and 15:30; were put on a one‐eye trial with prostaglandin analogues, and then subsequently received the same medication in the fellow eye were reviewed. Pretreatment baseline office IOP measurements and reductions in the first and second eyes were compared to determine variability and correlation, respectively.

Results:  Both groups showed significant variability in pretreatment baseline office IOP measurements. Peak IOP level was before noon in at least 70% of eyes in Group 1, 50% in Group 2. IOP dropped a mean of 8.8 ± 4.8 mmHg (34%, P = < 0.0001) in Group 1 and 4.9 ± 2.4 mmHg (30%, P = < 0.0001) in Group 2 during the one‐eye trial. Following bilateral use of the medication a mean drop of 7.5 ± 4.0 mmHg (31%, P = < 0.0001) in Group 1 and 2.9 ± 1.9 mmHg (18%, P = < 0.0001) in Group 2 were obtained. The IOP reduction between fellow‐eye pairs were significantly correlated in Group 1 (r = 0.541, P = < 0.0001) but not Group 2 (r =−0.310, P = 0.171).

Conclusions:  One‐eye trial is a feasible method to determine the effectiveness of prostaglandin analogues and to predict the amount of IOP reduction in the fellow eye in patients with high tension glaucoma.
Documentation of corneal epithelial defects with fluorescein‐enhanced digital fundus camera photography
Authors: Dean Simon J , Novitskaya Elena S , Moore Tara CB , Moore Johnny E , Sharma Anant
Published: March 2008

Abstract

The advent of digital photography in the ophthalmic setting has provided not only a means of documenting pathology, but with instantaneous results, it is possible to aid clinical diagnosis and management. This study was designed to demonstrate the ability to image corneal epithelial lesions stained with fluorescein, with a digital fundus camera set on fluorescein angiography settings. The contrast of this technique demonstrated both gross and subtle corneal epithelial lesions better than traditional methods. The results obtained demonstrated the high sensitivity and high contrast images this technique can facilitate in every ophthalmic practice equipped with a fundus camera with digital fluorescein angiography capability.
Joint capsule treatment with enkephalin‐encoding HSV‐1 recombinant vector reduces inflammatory damage and behavioural sequelae in rat CFA monoarthritis
Authors: Lu Ying , McNearney Terry A. , Wilson Steven. P. , Yeomans David C. , Westlund Karin N.
Published: March 2008

This study assessed enkephalin expression induced by intra‐articular application of recombinant, enkephalin‐encoding herpes virus (HSV‐1) and the impact of expression on nociceptive behaviours and synovial lining inflammation in arthritic rats. Replication‐conditional HSV‐1 recombinant vectors with cDNA encoding preproenkephalin (HSV‐ENK), or control transgene β‐galactosidase cDNA (HSV‐β‐gal; control) were injected into knee joints with complete Freund's adjuvant (CFA). Joint temperatures, circumferences and nociceptive behaviours were monitored on days 0, 7, 14 and 21 post CFA and vector treatments. Lumbar (L4–6) dorsal root ganglia (DRG) and spinal cords were immunostained for met‐enkephalin (met‐ENK), β‐gal, HSV‐1 proteins and Fos. Joint tissues were immunostained for met‐ENK, HSV‐1 proteins, and inflammatory mediators Regulated on Activation, Normal T‐cell Expressed and Secreted (RANTES) and cyclo‐oxygenase‐2, or stained with haematoxylin and eosin for histopathology. Compared to exuberant synovial hypertrophy and inflammatory cell infiltration seen in arthritic rats treated with CFA only or CFA and HSV‐β‐gal, the CFA‐ and HSV‐ENK‐treated arthritic rats had: (i) striking preservation of synovial membrane cytoarchitecture with minimal inflammatory cell infiltrates; (ii) significantly improved nociceptive behavioural responses to mechanical and thermal stimuli; (iii) normalized Fos staining in lumbar dorsal horn; and (iv) significantly increased met‐ENK staining in ipsilateral synovial tissue, lumbar DRG and spinal cord. The HSV‐1 and transgene product expression were confined to ipsilateral lumbar DRG (HSV‐1, met‐ENK, β‐gal). Only transgene product (met‐ENK and β‐gal) was seen in lumbar spinal cord sections. Targeted delivery of enkephalin‐encoding HSV‐1 vector generated safe, sustained opioid‐induced analgesia with protective anti‐inflammatory blunting in rat inflammatory arthritis.
Auditory Scene Analysis: the interaction of stimulation rate and frequency separation on pre‐attentive grouping
Authors: De Sanctis Pierfilippo , Ritter Walter , Molholm Sophie , Kelly Simon P. , Foxe John J.
Published: March 2008

Segregation of auditory inputs into meaningful acoustic groups is a key element of auditory scene analysis. Previously, we showed that two interwoven sets of tones differing widely along multiple feature dimensions (duration, pitch and location) were pre‐attentively separated into different groups, and that tones separated in this manner did not elicit the mismatch negativity component with respect to each other. Grouping was studied with human subjects using a stimulus rate too slow to induce streaming. Here, we varied the separation of tone sequences along a single feature dimension, i.e. frequency. Frequency differences were either 24 Hz (small) or 1054 Hz (large). Two relatively slow stimulus rates were used (2.7 or 1 tone/s) to explicitly investigate grouping outside the so‐called ‘streaming effect’, which requires rates of about 4 tones/s or faster. Two tones were presented in a quasi‐random manner with embedded trains of one to four identical tones in a row. Deviants were defined as frequency switches after trains of four identical tones. Mismatch negativity was only elicited for small frequency switches at the slower stimulation rate. The data indicate that pre‐attentive grouping of tones occurred when the frequency difference that separated them was large, regardless of stimulation rate. For small frequency differences, inputs were only grouped separately when the stimulation rate was relatively fast.
Cytoplasmic calcium mediates oxidative damage in an excitotoxic /energetic deficit synergic model in rats
Authors: Pérez‐De La Cruz Verónica , Konigsberg Mina , Pedraza‐Chaverri José , Herrera‐Mundo Nieves , Díaz‐Muñoz Mauricio , Morán Julio , Fortoul‐van der Goes Teresa , Rondán‐Zárate Adrián , Maldonado Perla D. , Ali Syed F. , Santamaría Abel
Published: March 2008

Excessive calcium is responsible for triggering different potentially fatal metabolic pathways during neurodegeneration. In this study, we evaluated the role of calcium on the oxidative damage produced in an in vitro combined model of excitotoxicity/energy deficit produced by the co‐administration of quinolinate and 3‐nitropropionate to brain synaptosomal membranes. Synaptosomal fractions were incubated in the presence of subtoxic concentrations of these agents (21 and 166 µm, respectively). In order further to characterize possible toxic mechanisms involved in oxidative damage in this experimental paradigm, agents with different properties – dizocilpine, acetyl l‐carnitine, iron porphyrinate and S‐allylcysteine – were tested at increasing concentrations (10–1000 µm). Lipid peroxidation was assessed by the formation of thiobarbituric acid‐reactive substances. For confirmatory purposes, additional fractions were incubated in parallel in the presence of the intracellular calcium chelator 1,2‐bis(2‐aminophenoxy)ethane‐N,N,N′,N′‐tetraacetic acid‐acetoxymethyl ester (BAPTA‐AM). Under physiological conditions of extracellular calcium availability, synaptomes exposed to both toxins displayed an increased lipoperoxidation (76% above controls), and this effect was partially attenuated by the tested agents as follows: dizocilpine = iron porphyrinate > acetyl l‐carnitine > S‐allylcysteine. When the incubation medium was deprived of calcium, the lipoperoxidative effect achieved in this experimental paradigm was still high (49% above the control), and the order of attenuation was: iron porphyrinate > S‐allylcysteine > acetyl l‐carnitine > dizocilpine. BAPTA‐AM was effective in preventing the pro‐oxidant action of both toxins, promoting even lower peroxidative levels than those quantified under basal conditions. Our results suggest that the lipid peroxidation induced in synaptosomal fractions by quinolinate plus 3‐nitropropionate is largely dependent on the cytoplasmic concentrations of calcium.
Metabotropic glutamate receptor 1 (mGluR1) and 5 (mGluR5) regulate late phases of LTP and LTD in the hippocampal CA1 region in vitro
Authors: Neyman Sergey , Manahan‐Vaughan Denise
Published: March 2008

The group I metabotropic glutamate receptors, mGluR1 and mGluR5, exhibit differences in their regulation of synaptic plasticity, suggesting that these receptors may subserve separate functional roles in information storage. In addition, although effects in vivo are consistently described, conflicting reports of the involvement of mGluRs in hippocampal synaptic plasticity in vitro exist. We therefore addressed the involvement of mGluR1 and mGluR5 in long‐term potentiation (LTP) and long‐term depression (LTD) in the hippocampal CA1 region of adult male rats in vitro. The mGluR1 antagonist (S)‐(+)‐α‐amino‐4‐carboxy‐2‐methylbenzene‐acetic acid (LY367385) impaired both induction and late phases of both LTP and LTD, when applied before high‐frequency tetanization (HFT; 100 Hz) or low‐frequency stimulation (LFS; 1 Hz), respectively. Application after either HFT or LFS had no effect. The mGluR5 antagonist 2‐methyl‐6‐(phenylethynyl)pyridine (MPEP), when given before HFT, inhibited both the induction and late phases of LTP. When given after HFT, late LTP was inhibited. MPEP, given prior to LFS, impaired LTD induction, although stable LTD was still expressed. Application after LFS significantly impaired late phases of LTD. Activation of protein synthesis may comprise a key mechanism underlying the group I mGluR contribution to synaptic plasticity. The mGluR5 agonist (R,S)‐2‐chloro‐5‐hydroxyphenylglycine (CHPG) converted short‐term depression into LTD. Effects were prevented by application of the protein synthesis inhibitor anisomycin, suggesting that protein synthesis is triggered by group I mGluR activation to enable persistency of synaptic plasticity. Taken together, these data support the notion that both mGluR1 and mGluR5 are critically involved in bidirectional synaptic plasticity in the CA1 region and may enable functional differences in information encoding through LTP and LTD.
Mushroom bodies modulate salience‐based selective fixation behavior in Drosophila
Authors: Xi Wang , Peng Yueqing , Guo Jianzeng , Ye Yizhou , Zhang Ke , Yu Feng , Guo Aike
Published: March 2008

Mushroom bodies (MBs), one of the central brain structures in Drosophila melanogaster, are involved in several cognitive behaviors, such as olfactory learning and memory, visual context generalization, choice behavior facing conflicting cues. Attention is a cognitive behavior, and it facilitates a focus on the attended event while filtering out irrelevant events, thereby allowing more rapid and accurate reactions at a lower threshold in primates. Using the visual orientation paradigm in a flight simulator, we observed that MBs modulate salience‐based selective fixation behavior, which resembles attention in primates to a certain degree. We found that the fixation ability of MB‐deficient flies was significantly reduced when the contrast levels were lowered as well as when a certain amount of background noise was applied. Moreover, MB‐deficient flies exhibited poor object fixation ability in the presence of an olfactory ‘distracter’. Furthermore, during visual selection among multiple objects of different contrast, flies with MBs were able to ‘pop‐out’ of the most salient object in a three‐object selection paradigm. Finally, we determined that flies exhibited cross‐modal synergistic integration between olfactory and visual signals during object‐fixation behavior, which was independent of MBs. Taken together, our findings suggest that MBs do not contribute to cross‐modal synergetic integration between olfactory and visual signals; instead, they confer sensory gain control and inhibitory gating in flies, this property allows entry of the salient signal as well as filters out background noise and irrelevant signals.
Use of episcopic differential interference contrast microscopy to identify bacterial biofilms on salad leaves and track colonization by Salmonella Thompson
Authors: Warner J. C. , Rothwell S. D. , Keevil C. W.
Published: March 2008

Zoonotic pathogens such as Salmonella can cause gastrointestinal illness if they are ingested with food. Foods such as salads pose a greater risk because they are consumed raw and have been the source of major outbreaks of disease from fresh produce. The novel light microscopy methods used in this study allow detailed, high resolution imaging of the leaf surface environment (the phyllosphere) and allow pathogen tracking. Episcopic differential interference contrast microscopy coupled with epifluorescence was used to view the natural microflora in situ on salad leaves and their topographical distribution. Fluorescent nucleic acid staining was used to differentiate between bacterial colonists and inorganic debris. Salmonella enterica serovar Thompson expressing green fluorescent protein was inoculated onto individual spinach leaves for 24 h at 22°C in order to observe spatial and temporal patterning of colonization on the two surfaces of each leaf under different osmotic conditions. The results obtained show that salad leaves are host to high numbers of bacteria, typically 105 per square millimetre. Cells are present in complex three‐dimensional aggregations which often have a slimy appearance, suggesting the presence of biofilms. Washing of the leaves had little effect on the number of adherent pathogens, suggesting very strong attachment. Episcopic differential interference contrast microscopy is a rapid alternative to both scanning electron microscopy and confocal laser scanning microscopy for visualizing leaf topography and biofilm formation in the natural state.
Vertical distribution of methane metabolism in microbial mats of the Great Sippewissett Salt Marsh
Authors: Buckley Daniel H. , Baumgartner Laura K. , Visscher Pieter T.
Published: March 2008

Methane metabolism was investigated with respect to depth in intertidal microbial mats of the Great Sippewissett Salt Marsh, Massachusetts. Although sulfate‐reducing organisms dominate anaerobic carbon consumption in marine microbial mats, methanogens persist and their activity varies vertically and temporally in the mat system. In the Sippewissett mats, potential methane production for all mat layers was higher in the spring (17.2 ± 4.5 nmol CH4 cm−2 day−1) than in the fall (3.0 ± 1.1 nmol CH4 cm−2 day−1) and maximal rates were consistently observed in proximity to the chemocline (5–10 mm depth). The methane flux from the mat surface did not vary appreciably over time due to the ability of methanotrophic activity to limit net methane production. Evidence indicates that both aerobic and anaerobic oxidation of methane occurs in this system. The importance of H2 as a substrate for methanogenesis appeared to be the greatest at the mat surface (0–10 mm), and the proportion of methylotrophic methanogens generally increased with depth. These results suggest that both non‐equilibrium H2 dynamics and the use of non‐competitive substrates permit coexistence of methanogens and sulfate‐reducing organisms in the mat system.
Intestinal obstruction from inspissated barium (Barolith): a systematic review of all cases from 1950 to 2006
Authors: Kurer M. A. , Davey C. , Chintapatla S.
Published: March 2008

Objective  Having encountered a case of large bowel obstruction secondary to a barolith and successfully treated it using colonoscopic dissolution, we systematically reviewed all cases of barolith obstruction to appreciate its incidence and explore its methods of treatment.

Method  A literature search was carried out in the databases British Nursing Index, Cinahal, Embase, Medline, and Pub Med. There was no restriction placed on language of publication in the search.

Results  There were 22 reports describing a total of 31 cases. About one third of the reported cases were successfully treated with conservative measures including the use of laxatives. Significantly, surgery was performed in nearly half of the patients. Interestingly, endoscopic dissolution was attempted in only 3 cases and it was successful in all of them.

Conclusion  This systematic review reveals several reported cases of barolith obstruction from 1950–2006. Only three case reports described colonoscopic dissolution. In our institute, we have recently encountered a case of large bowel obstruction secondary to a barolith and we successfully treated it using colonoscopic dissolution. Given the absence of guidelines to treat barolith induced obstruction, we are of the opinion that should a barolith obstruction occur, in the absence of perforation or ischaemic bowel, endoscopic dissolution by an experienced endoscopist under general anaesthetic offers a safe, effective, and minimally invasive method of relieving the obstruction. Should this fail surgery is indicated.
Antidiabetic and toxicological evaluations of naringenin in normoglycaemic and NIDDM rat models and its implications on extra‐pancreatic glucose regulation
Authors: Ortiz‐Andrade R. R , Sánchez‐Salgado J. C. , Navarrete‐Vázquez G. , Webster S. P. , Binnie M. , García‐Jiménez S. , León‐Rivera I. , Cigarroa‐Vázquez P. , Villalobos‐Molina R. , Estrada‐Soto S.
Published: March 2008

Aim:  The present investigation was designed to determine the in vivo antidiabetic effect of naringenin (NG) in normoglycaemic and diabetic rat models through blood glucose (GLU) measurements following acute and subchronic time periods. Possible modes of action of NG were investigated and its acute toxicity determined.

Methods:  Normoglycaemic and non‐insulin‐dependent diabetes mellitus (NIDDM) rat models were treated for acute and subchronic (5 days) time periods with 50 mg/kg/day of NG. Blood biochemical profiles were determined after 5 days of the treatment in normoglycaemic and NIDDM rats using commercial kits for GLU, triglycerides (TG), total cholesterol (CHOL) and high‐density lipoprotein (HDL). In order to elucidate its antidiabetic mode of action, NG was administered intragastrically and an oral glucose tolerance test performed using GLU and sucrose (2 g/kg) as substrates. The inhibitory effect of a single concentration of NG (10 μM) on 11β‐hydroxysteroid dehydrogenase type 1 (11β‐HSD1) activity in vitro was determined. Finally, the preclinical safety and tolerability of NG was determined by toxicological evaluation in mice and rats using Organization for Economic Cooperation and Development (OECD) protocols.

Results:  Intragastrically administered NG (50 mg/kg) induced a significant decrease in plasma GLU in normoglycaemic and NIDDM rat models (p < 0.05) following acute and subchronic time periods. After 5 days of administration, NG produced significant diminished blood GLU and TG levels in streptozotocin–nicotinamide–induced diabetic rats. The administration of NG to normal rats significantly increased the levels of TG, CHOL and HDL (p < 0.05). NG (5 and 50 mg/kg) induced a total suppression in the increase of plasma GLU levels after administration of substrates (p < 0.01), but NG did not produce inhibition of α‐glucosidase activity in vitro. However, NG (10 μM) was shown to inhibit 11β‐HSD1 activity by 39.49% in a cellular enzyme assay. Finally, NG showed a Medium Lethal Dose LD50 > 5000 mg/kg and ranking at level five based on OECD protocols.

Conclusion:  Our findings suggest that NG may exert its antidiabetic effect by extra‐pancreatic action and by suppressing carbohydrate absorption from intestine, thereby reducing the postprandial increase in blood GLU levels.