bluuebunny/crossref_metadata_2025_split huggingface dataset:
Further evidence that major outer membrane proteins homologous to OmpA in Porphyromonas gingivalis stabilize bacterial cells
Authors: Iwami J. , Murakami Y. , Nagano K. , Nakamura H. , Yoshimura F. 
Published: September 2007

Introduction:  Porphyromonas gingivalis is one of the most important bacteria in the progression of chronic periodontal disease. We hypothesized that the major outer membrane proteins Pgm6/7, which are homologous to the OmpA protein in Escherichia coli, might contribute to the stabilization of the cell surface. In this study, the effects of Pgm6/7 on the cell surface were examined morphologically.Methods:  Deletion mutants of Pgm6/7 (Δ694, Δ695 and Δ695–694) were constructed using the polymerase chain reaction‐based overlap extension method. Wild‐type ATCC 33277 and Pgm6/7 mutants were grown under anaerobic conditions. Whole cells and thin sections of fixed cells were stained and examined by transmission electron microscopy.Results:  Compared with the wild‐type, numerous vesicles released from cells were observed in each deletion mutant. The outer membrane appeared wavy and irregular. Increased numbers of vesicles were confirmed after their preparation from the culture supernatant. Total gingipain activity in vesicles was increased five‐ to 10‐fold in the deletion mutants.Conclusion:  This report provides further evidence that Pgm6/7 proteins in P. gingivalis play an important role in the maintenance of bacterial outer membrane integrity.
Steroid 5α‐reductase activity of Treponema denticola
Authors: Clark D. T. , Soory M. 
Published: September 2007

Introduction:  Previously we have shown that reference and freshly isolated Treponema denticola cultures possess 5α‐reductase (5α‐R) and 3β‐ and 17β‐hydroxysteroid dehydrogenase activity. A gene matching the 3‐oxo‐5α‐steroid 4‐dehydrogenase family protein (gene ID: 2739284; locus tag: TDE2697) has been identified in T. denticola ATCC 35405. The aim of the work presented here was to optimize assay conditions and determine steroid substrate specificities for the 5α‐R activity of T. denticola ATCC 33520.Methods:  5α‐R activity of cell‐free preparations was assayed with radioactive steroid substrates. 5α‐R‐reduced products were identified using thin‐layer chromatography and a radioisotope scanner. Assay conditions were optimized for co‐factor, buffer and pH requirements. Apparent substrate specificities were determined for progesterone, 4‐androstenedione, testosterone and corticosterone. The time–course for metabolism of radiolabelled progesterone and cholesterol substrates was investigated with anaerobic cultures.Results:  The optimum pH for 5α‐R was 5.5 and the preferred co‐factor was NADPH. The order of the steroids with respect to their 5α‐R substrate specificities was (in descending order): progesterone, 4‐androstenedione, testosterone and corticosterone. There are at least two intermediates in the synthesis of 5α‐dihydrocholesterol from cholesterol.Conclusion:  These results suggest that the 3‐oxo‐5α‐steroid 4‐dehydrogenase family protein gene of T. denticola codes for a functional protein that resembles mammalian 5α‐R isoenzyme 2 with regard to co‐factor requirement and pH optimum.
Antibiotic resistance in an in vitro subgingival biofilm model
Authors: Sedlacek M. J. , Walker C. 
Published: September 2007

Introduction:  The purpose of this study was to utilize an in vitro biofilm model of subgingival plaque to investigate resistances in subgingival biofilm communities to antibiotics commonly used as adjuncts to periodontal therapy.Methods:  Biofilms were grown on saliva‐coated hydroxyapatite supports in trypticase‐soy broth for 4 h–10 days and then exposed for 48 h to either increasing twofold concentrations of tetracycline, amoxicillin, clindamycin, and erythromycin or therapeutically achievable concentrations of tetracycline, doxycycline, minocycline, amoxicillin, metronidazole, amoxicillin/clavulanate, and amoxicillin/metronidazole.Results:  Concentrations necessary to inhibit bacterial strains in steady‐state biofilms were up to 250 times greater than the concentrations needed to inhibit the same strains grown planktonically. In the presence of therapeutically available antibiotic concentrations, significantly higher proportions of the biofilms remained viable as the biofilms reached steady‐state growth. The combinations of amoxicillin/clavulanate and amoxicillin/metronidazole were the most effective in suppressing growth. These combinations were particularly effective against biofilms up to and including 7 days of age and inhibited 90% or more of the bacteria present relative to untreated controls. As the biofilms approached steady state, these combinations were less effective with 50–60% of the bacteria retaining viability.Conclusion:  Most, but not all, species of subgingival bacteria are considerably more resistant in biofilms than in planktonic cultures. Resistance appeared to be age‐related because biofilms demonstrated progressive antibiotic resistance as they matured with maximum resistance coinciding with the steady‐state phase of biofilm growth.
Synthetic bromated furanone inhibits autoinducer‐2‐mediated communication and biofilm formation in oral streptococci
Authors: Lönn‐Stensrud J. , Petersen F. C. , Benneche T. , Scheie A. Aamdal 
Published: September 2007

Introduction:  Autoinducer‐2 (AI‐2) is a widespread communication‐signal molecule that allows bacteria to sense and react to environmental factors. In some streptococci AI‐2 is reported to be involved in virulence expression and biofilm formation. It has earlier been shown that the alga Delisea pulchra produces bromated furanones, which prevent bacterial colonization of the algae.Methods and results:  We have previously published a novel and simple synthesis of (Z)‐5‐bromomethylene‐2(5H)‐furanone. In this study we showed that our synthesized furanone inhibited biofilm formation and bioluminescence induction by Streptococcus anginosus, Streptococcus intermedius, and Streptococcus mutans, as well as bioluminescence induction by Vibrio harveyi BB152.Conclusion:  We suggest that the effect is linked to interference with the AI‐2 signaling pathway because adding furanone to the medium had no effect on the ability of the AI‐2‐defective S. anginosus luxS and S. intermedius luxS mutants to form biofilms.
Human cytomegalovirus is present in odontogenic cysts
Authors: Andric M. , Milasin J. , Jovanovic T. , Todorovic L. 
Published: September 2007

Introduction:  Recent studies suggest that some viruses, including human cytomegalovirus (CMV), may be involved in the pathogenesis of periapical lesions. Since periapical cysts (PCs) represent the next stage in the evolution of periapical granuloma, it seemed reasonable to investigate the presence of CMV in PCs and any possible relationship between its presence and the clinical features of those cysts, as well as to compare the results obtained with corresponding findings in non‐inflammatory lesions, like odontogenic keratocysts (OKCs).Methods:  Samples of 33 PCs and 10 OKCs, obtained at the time of surgery, were used for the detection of CMV DNA by polymerase chain reaction. Presence of the virus was correlated with clinical and radiographic features of the cysts.Results:  CMV was detected in 18 PCs (54.5%) and six OKCs (60%). The presence of CMV was more frequent in cyst samples collected from patients who reported previous episodes of acute infection. The presence of sinus tract was more frequent in CMV‐positive cysts and CMV presence was less frequent in a group of cysts showing signs of acute inflammation at the time of sample collection. The mean sizes of CMV‐positive and CMV‐negative PCs were almost the same; CMV‐positive OKCs were slightly larger than CMV‐negative OKCs. None of these results proved to be statistically significant.Conclusion:  The presence of CMV in the cystic wall is a common feature of both inflammatory and non‐inflammatory odontogenic cysts. Although this study has not proved that CMV affects pathogenesis of odontogenic cysts, such a possibility could not be ruled out.
Morphometric and Ultrastructural Changes in Ciliated Cells of the Oviductal Epithelium in Prolific Chinese Meishan and Large White Pigs during the Oestrous Cycle
Authors: Abe H , Hoshi H 
Published: September 2007

ContentsThere are some differences in reproductive features between the Chinese Meishan (CM) pig and Large White (LW) pig. The aim of the present study was to investigate the quantitative changes and ultrastructural features of ciliated cells in the various regions of the CM and LW pig oviduct during the follicular and luteal phases of the oestrous cycle. In the fimbrial and ampullar epithelia at the follicular phase, the ciliated cells were more plentiful than in the isthmic region in both pigs. In the CM pigs, there was a striking decrease in the percentage and cell height of ciliated cells in the luteal phase compared with the follicular phase. Although similar quantitative changes were observed in the LW pig oviduct, these changes were less dramatic than that in the CM pig oviduct. In both pigs, the percentage and cell height of ciliated cells in the isthmus were unchanged between the follicular and luteal phases. The ultrastructure of ciliogenic and ciliated cells was observed. In the fimbrial and ampullar epithelia during the follicular phase, most of the ciliated cells showed normal morphology, having many elongated cilia and mitochondria, but in the CM pig oviduct during the luteal phase many of the ciliated cells possessed immature cilia and swollen mitochondria. Cells undergoing ciliogenesis were frequently observed in the fimbriae and ampulla, and occasionally in the isthmus. Cytoplasmic protrusions containing variable numbers of ciliary axonemal complexes occurred in the fimbrial and ampullar epithelium in the CM pigs at the luteal phase, suggesting that deciliation of cells occurs by membrane‐bound cilia packets forming at the apices of cells and pinching off. These results demonstrate that there are regional variations in the cyclic changes associated with the oviductal ciliated cells of the pigs, while there are marked morphometrical and ultrastructural changes in oviductal ciliated cells of the CM pigs compared with that of the LW pigs.
Oral administration of taurine improves experimental pancreatic fibrosis
Authors: Shirahige Akinori , Mizushima Takaaki , Matsushita Koki , Sawa Kiminari , Ochi Koji , Ichimura Mitsuko , Tanioka Hiroaki , Shinji Toshiyuki , Koide Norio , Tanimoto Mitsune 
Published: September 2007

AbstractBackground and Aim: The mechanism of pancreatic fibrosis is unclear. Taurine is used in the clinical treatment of a wide variety of diseases, but its effect on improving pancreatic fibrosis is unknown. We examined whether a diet with added taurine improves pancreatic fibrosis induced by dibutyltin dichloride (DBTC) in an experimental chronic pancreatitis rat model. In addition, we examined the influence of taurine on pancreatic stellate cells.Methods: Pancreatic fibrosis was induced by DBTC. Rats were fed a taurine‐containing diet or a normal diet and were killed at 4 weeks. Pancreatic stellate cells were isolated from male Wistar rats. Cultured pancreatic stellate cells were incubated with or without taurine chloramine. Type I collagen and transforming growth factor‐β1 secretion was evaluated by ELISA, and matrix metalloproteinase activity was assessed by gelatin zymography. Interleukin‐6, interleukin‐2, and transforming growth factor‐β1 levels in the supernatants of pancreatic tissue homogenates were measured.Results: Pancreatic fibrosis induced by DBTC was improved remarkably by the oral administration of the taurine‐containing diet. Taurine chloramine decreased type I collagen, transforming growth factor‐β1, and matrix metalloproteinases 2 of the pancreatic stellate cell culture supernatant. Increased interleukin‐6 and decreased interleukin‐2 were found in the supernatants of the pancreatic tissue homogenates of DBTC‐induced pancreatitis rats compared with other groups.Conclusion: The oral administration of taurine improves pancreatic fibrosis. Taurine chloramine inhibits transforming growth factor‐β1 produced from activated pancreatic stellate cells and improves pancreatic fibrosis.
PLAYING GOD AND THE ETHICS OF DIVINE NAMES: AN ISLAMIC PARADIGM FOR BIOMEDICAL ETHICS
Authors: SHAHZAD QAISER 
Published: September 2007

ABSTRACTThe notion of ‘playing God’ frequently comes to fore in discussions of bioethics, especially in religious contexts. The phrase has always been analyzed and discussed from Christian and secular standpoints. Two interpretations exist in the literature. The first one takes ‘God’ seriously and playing ‘playfully’. It argues that this concept does state a principle but invokes a perspective on the world. The second takes both terms playfully. In the Islamic Intellectual tradition, the Sufi concept of ‘adopting divine character traits’ provides a legitimate paradigm for ‘playing God’. This paradigm is interesting because here we take both terms ‘God’ and ‘playing’ seriously. It is significant for the development of biomedical ethics in contemporary Islamic societies as it can open new vistas for viewing biotechnological developments.
TRANSHUMANISM AND MORAL EQUALITY
Authors: WILSON JAMES 
Published: September 2007

ABSTRACTConservative thinkers such as Francis Fukuyama have produced a battery of objections to the transhumanist project of fundamentally enhancing human capacities. This article examines one of these objections, namely that by allowing some to greatly extend their capacities, we will undermine the fundamental moral equality of human beings. I argue that this objection is groundless: once we understand the basis for human equality, it is clear that anyone who now has sufficient capacities to count as a person from the moral point of view will continue to count as one even if others are fundamentally enhanced; and it is mistaken to think that a creature which had even far greater capacities than an unenhanced human being should count as more than an equal from the moral point of view.
Rolling Back the African State: Implications for Social Development in Ghana
Authors: Laird Siobhan E. 
Published: September 2007

AbstractThe New Policy Agenda of the Reagan and Thatcher years has profoundly influenced aid flows from the industrialized countries of North America and Western Europe to the developing nations of sub‐Saharan Africa. The application of neo‐liberal principles to the disbursement of multilateral and bilateral aid for social development has resulted in the diversion of donor funding away from the public sector towards non‐governmental organizations. The consequences of relegating the role of the public sector in social development is explored through qualitative research conducted in Ghana with state‐employed community development workers. The study exposes how severe financial constraint within the state sector distorts the targeting of beneficiaries and social development activity. This differs from findings revealed by interviews with social development workers employed by international non‐governmental organizations. These indicate that such agencies are able to sustain effectively resourced fieldworkers who are in a position to form positive working relationships with beneficiaries. The circumstances of the Department of Community Development and its relationships with non‐governmental agencies in Ghana are used to explore the effects on state‐building of the New Policy Agenda in the sub‐Saharan region.
The Organization of Decision‐making and the Dynamics of Policy Drift: A Canadian Health Sector Example
Authors: Gildiner Alina 
Published: September 2007

AbstractThis historical‐institutionalist case study of public–private change in the rehabilitation health sector in Ontario, Canada, seeks to build on literature about the politics of policy drift, particularly with respect to health care systems. Rather than turning to higher‐order institutional factors, such as federalism and overall financing agreements between states and the medical profession, or to economic indicators such as change in expenditures, however, it posits that the particularities of how welfare‐policy sectors are organized with respect to their decision‐making contribute to drift. Such organization is framed by two factors. The first is the set of rules by which the public–private boundary is drawn, and the second is the structuring of public institutions that set legislation and regulation, and organize the policy networks attendant on them, around these boundaries. The degree of coordination or fragmentation among these, this case suggests, is a factor in the politics and dynamics of drift.
The mycorrhiza helper bacteria revisited
Authors: Frey‐Klett P. , Garbaye J. , Tarkka M. 
Published: September 2007

SummaryIn natural conditions, mycorrhizal fungi are surrounded by complex microbial communities, which modulate the mycorrhizal symbiosis. Here, the focus is on the so‐called ‘mycorrhiza helper bacteria’ (MHB). This concept is revisited, and the distinction is made between the helper bacteria, which assist mycorrhiza formation, and those that interact positively with the functioning of the symbiosis. After considering some examples of MHB from the literature, the ecological and evolutionary implications of the relationships of MHB with mycorrhizal fungi are discussed. The question of the specificity of the MHB effect is addressed, and an assessment is made of progress in understanding the mechanisms of the MHB effect, which has been made possible through the development of genomics. Finally, clear evidence is presented suggesting that some MHB promote the functioning of the mycorrhizal symbiosis. This is illustrated for three critical functions of practical significance: nutrient mobilization from soil minerals, fixation of atmospheric nitrogen, and protection of plants against root pathogens. The review concludes with discussion of future research priorities regarding the potentially very fruitful concept of MHB.

Contents

Summary
22

I.
Introduction
23

II.
Evidence for the occurrence of MHB
23

III.
Ecological and evolutionary implications of MHB
23

IV.
The question of MHB specificity
27

V.
Mechanisms of the MHB effect
28

VI.
Role of MHB in mycorrhizal functions
31

VII.
Conclusions and research priorities
32

References
33
Sentinels at the wall: cell wall receptors and sensors
Authors: Humphrey Tania V. , Bonetta Dario T. , Goring Daphne R. 
Published: September 2007

SummaryThe emerging view of the plant cell wall is of a dynamic and responsive structure that exists as part of a continuum with the plasma membrane and cytoskeleton. This continuum must be responsive and adaptable to normal processes of growth as well as to stresses such as wounding, attack from pathogens and mechanical stimuli. Cell expansion involving wall loosening, deposition of new materials, and subsequent rigidification must be tightly regulated to allow the maintenance of cell wall integrity and co‐ordination of development. Similarly, sensing and feedback are necessary for the plant to respond to mechanical stress or pathogen attack. Currently, understanding of the sensing and feedback mechanisms utilized by plants to regulate these processes is limited, although we can learn from yeast, where the signalling pathways have been more clearly defined. Plant cell walls possess a unique and complicated structure, but it is the protein components of the wall that are likely to play a crucial role at the forefront of perception, and these are likely to include a variety of sensor and receptor systems. Recent plant research has yielded a number of interesting candidates for cell wall sensors and receptors, and we are beginning to understand the role that they may play in this crucial aspect of plant biology.

Contents

Summary
7

I.
Introduction
8

II.
Cell expansion and plant growth
8

III.
Cell wall responses to stress
11

IV.
Pathogen attack and mechanical stimuli
11

V.
Lessons from yeast
12

VI.
Candidate sensors and receptors in plants
14

VII.
Conclusions
17

Acknowledgements
17

References
17
Regulatory proteins of eukaryotic initiation factor 2‐alpha subunit (eIF2α) phosphatase, under ischemic reperfusion and tolerance
Authors: García‐Bonilla Lidia , Cid Cristina , Alcázar Alberto , Burda Jozef , Ayuso Irene , Salinas Matilde 
Published: September 2007

AbstractPhosphorylation of the α subunit of eukaryotic translation initiation factor 2 (eIF2α), which is one of the substrates of protein phosphatase 1 (PP1), occurs rapidly during the first minutes of post‐ischemic reperfusion after an episode of cerebral ischemia. In the present work, two experimental models of transient global ischemia and ischemic tolerance (IT) were used to study PP1 interacting/regulatory proteins following ischemic reperfusion. For that purpose we utilized PP1 purified by microcystin chromatography, as well as 2D DIGE of PP1α and PP1γ immunoprecipitates. The highest levels of phosphorylated eIF2α found after 30 min reperfusion in rats without IT, correlated with increased levels in PP1 immunoprecipitates of the inhibitor DARPP32 as well as GRP78 and HSC70 proteins. After 4 h reperfusion, the levels of these proteins in PP1c complexes had returned to control values, in parallel to a significant decrease in eIF2α phosphorylated levels. IT that promoted a decrease in eIF2α phosphorylated levels after 30 min reperfusion induced the association of GADD34 with PP1c, while prevented that of DARPP32, GRP78, and HSC70. Different levels of HSC70 and DARPP32 associated with PP1α and PP1γ isoforms, whereas GRP78 was only detected in PP1γ immunoprecipitates. Here we suggest that PP1, through different signaling complexes with their interacting proteins, may modulate the eIF2α phosphorylation/dephosphorylation during reperfusion after a transient global ischemia in the rat brain. Of particular interest is the potential role of GADD34/PP1c complexes after tolerance acquisition.
A novel biological function for CD44 in axon growth of retinal ganglion cells identified by a bioinformatics approach
Authors: Ries Albert , Goldberg Jeffrey L. , Grimpe Barbara 
Published: September 2007

AbstractThe failure of CNS regeneration and subsequent motor and sensory loss remain major unsolved questions despite massive accumulation of experimental observations and results. The sheer volume of data and the variety of resources from which these data are generated make it difficult to integrate prior work to build new hypotheses. To address these challenges we developed a prototypic suite of computer programs to extract protein names from relevant publications and databases and associated each of them with several general categories of biological functions in nerve regeneration. To illustrate the usefulness of our data mining approach, we utilized the program output to generate a hypothesis for a biological function of CD44 interaction with osteopontin (OPN) and laminin in axon outgrowth of CNS neurons. We identified CD44 expression in retinal ganglion cells and when these neurons were plated on poly‐l‐lysine 3% of them initiated axon growth, on OPN 15%, on laminin‐111 (1×) 41%, on laminin‐111 (0.5×) 56%, and on a mixture of OPN and laminin (1×) 67% of neurons generated axon growth. With the aid of a deoxyribozyme (DNA enzyme) to CD44 that digests the target mRNA, we demonstrated that a reduction of CD44 expression led to reduced axon initiation of retinal ganglion cells on all substrates. We suggest that such an integrative, applied systems biology approach to CNS trauma will be critical to understand and ultimately overcome the failure of CNS regeneration.