bluuebunny/crossref_metadata_2025 huggingface dataset:
Homeotic factor ATBF1 induces the cell cycle arrest associated with neuronal differentiation
Authors: Jung Cha-Gyun , Kim Hye-Jung , Kawaguchi Makoto , Khanna Kum Kum , Hida Hideki , Asai Kiyofumi , Nishino Hitoo , Miura Yutaka
Published: October 2005

The present study aimed to elucidate the function of AT motif-binding factor 1 (ATBF1) during neurogenesis in the developing brain and in primary cultures of neuroepithelial cells and cell lines (Neuro 2A and P19 cells). Here, we show that ATBF1 is expressed in the differentiating field in association with the neuronal differentiation markers β-tubulin and MAP2 in the day E14.5 embryo rat brain, suggesting that it promotes neuronal differentiation. In support of this, we show that ATBF1 suppresses nestin expression, a neural stem cell marker, and activates the promoter of Neurod1 gene, a marker for neuronal differentiation. Furthermore, we show that in Neuro 2A cells, overexpressed ATBF1 localizes predominantly in the nucleus and causes cell cycle arrest. In P19 cells, which formed embryonic bodies in the floating condition, ATBF1 is mainly cytoplasmic and has no effect on the cell cycle. However, the cell cycle was arrested when ATBF1 became nuclear after transfer of P19 cells onto adhesive surfaces or in isolated single cells. The nuclear localization of ATBF1 was suppressed by treatment with caffeine, an inhibitor of PI(3)K-related kinase activity of ataxa-telangiectasia mutated (ATM) gene product. The cytoplasmic localization of ATBF1 in floating/nonadherent cells is due to CRM1-dependent nuclear export of ATBF1. Moreover, in the embryonic brain ATBF1 was expressed in the cytoplasm of proliferating stem cells on the ventricular zone, where cells are present at high density and interact through cell-to-cell contact. Conversely,in the differentiating field, where cell density is low and extracellular matrix is dense, the cell-to-matrix interaction triggered nuclear localization of ATBF1, resulting in the cell cycle arrest. We propose that ATBF1 plays an important role in the nucleus by organizing the neuronal differentiation associated with the cell cycle arrest.
Fgf signaling instructs position-dependent growth rate during zebrafish fin regeneration
Authors: Lee Yoonsung , Grill Sara , Sanchez Angela , Murphy-Ryan Maureen , Poss Kenneth D.
Published: October 2005

During appendage regeneration in urodeles and teleosts, tissue replacement is precisely regulated such that only the appropriate structures are recovered, a phenomenon referred to as positional memory. It is believed that there exists, or is quickly established after amputation, a dynamic gradient of positional information along the proximodistal (PD) axis of the appendage that assigns region-specific instructions to injured tissue. These instructions specify the amount of tissue to regenerate, as well as the rate at which regenerative growth is to occur. A striking theme among many species is that the rate of regeneration is more rapid in proximally amputated appendages compared with distal amputations. However, the underlying molecular regulation is unclear. Here, we identify position-dependent differences in the rate of growth during zebrafish caudal fin regeneration. These growth rates correlate with position-dependent differences in blastemal length, mitotic index and expression of the Fgf target genes mkp3, sef and spry4. To address whether PD differences in amounts of Fgf signaling are responsible for position-dependent blastemal function, we have generated transgenic fish in which Fgf receptor activity can be experimentally manipulated. We find that the level of Fgf signaling exhibits strict control over target gene expression, blastemal proliferation and regenerative growth rate. Our results demonstrate that Fgf signaling defines position-dependent blastemal properties and growth rates for the regenerating zebrafish appendage.
SRC-1, a non-receptor type of protein tyrosine kinase, controls the direction of cell and growth cone migration inC. elegans
Authors: Itoh Bunsho , Hirose Takashi , Takata Nozomu , Nishiwaki Kiyoji , Koga Makoto , Ohshima Yasumi , Okada Masato
Published: October 2005

Src family tyrosine kinase (SFK) has been implicated in the regulation of cell adhesion and migration during animal development. We show that SRC-1, an ortholog of SFK, plays an essential role in directing cell migration in Caenorhabditis elegans. The mutation in the src-1 gene results in defective distal tip cell (DTC)-directed gonad morphogenesis in an activity-dependent and DTC cell-autonomous manners. In the src-1mutants, DTCs fail to turn and continue their centrifugal migration along the ventral muscles. The effect of the src-1 mutation is suppressed by mutations in genes that function in the CED/Rac pathway, suggesting that SRC-1 in DTCs is an upstream regulator of a Rac pathway that controls cytoskeletal remodeling. In the src-1 mutant, the expression of unc-5/netrin receptor is normally regulated, and neither the precocious expression of UNC-5 nor the mutation in the unc-5 gene significantly affects the DTC migration defect. These data suggest that SRC-1 acts in the netrin signaling in DTCs. The src-1 mutant also exhibits cell-autonomous defects in the migration and growth cone path-finding of Q neuroblast descendants AVM and PVM. However, these roles of SRC-1 do not appear to involve the CED/Rac pathway. These findings show that SRC-1 functions in responding to various extracellular guidance cues that direct the cell migration via disparate signaling pathways in different cell types.
The JIL-1 kinase interacts with lamin Dm0 and regulates nuclear lamina morphology ofDrosophilanurse cells
Authors: Bao Xiaomin , Zhang Weiguo , Krencik Robert , Deng Huai , Wang Yanming , Girton Jack , Johansen Jørgen , Johansen Kristen M.
Published: October 2005

We have used a yeast two-hybrid screen to identify lamin Dm0 as an interaction partner for the nuclear JIL-1 kinase. This molecular interaction was confirmed by GST-fusion protein pull-down assays and by co-immunoprecipitation experiments. Using deletion construct analysis we show that a predicted globular domain of the basic region of the COOH-terminal domain of JIL-1 was sufficient for mediating the molecular interactions with lamin Dm0. A reciprocal analysis with truncated lamin Dm0 constructs showed that the interaction with JIL-1 required sequences in the tail domain of lamin Dm0 that include the Ig-like fold. Further support for a molecular interaction between JIL-1 and lamin Dm0 in vivo was provided by genetic interaction assays. We show that nuclear positioning and lamina morphology were abnormal in JIL-1 mutant egg chambers. The most common phenotypes observed were abnormal nurse cell nuclear lamina protrusions through the ring canals near the oocyte, as well as dispersed and mislocalized lamin throughout the egg chamber. These phenotypes were completely rescued by a full-length JIL-1 transgenic construct. Thus, our results suggest that the JIL-1 kinase is required to maintain nuclear morphology and integrity of nurse cells during oogenesis and that this function may be linked to molecular interactions with lamin Dm0.
Phosphorylation of Nlp by Plk1 negatively regulates its dynein-dynactin-dependent targeting to the centrosome
Authors: Casenghi Martina , Barr Francis A. , Nigg Erich A.
Published: October 2005

When cells enter mitosis the microtubule (MT) network undergoes a profound rearrangement, in part due to alterations in the MT nucleating and anchoring properties of the centrosome. Ninein and the ninein-like protein (Nlp) are centrosomal proteins involved in MT organisation in interphase cells. We show that the overexpression of these two proteins induces the fragmentation of the Golgi, and causes lysosomes to disperse toward the cell periphery. The ability of Nlp and ninein to perturb the cytoplasmic distribution of these organelles depends on their ability to interact with the dynein-dynactin motor complex. Our data also indicate that dynactin is required for the targeting of Nlp and ninein to the centrosome. Furthermore, phosphorylation of Nlp by the polo-like kinase 1 (Plk1) negatively regulates its association with dynactin. These findings uncover a mechanism through which Plk1 helps to coordinate changes in MT organisation with cell cycle progression, by controlling the dynein-dynactin-dependent transport of centrosomal proteins.
Improved Influence Functions For Uniform Triangular Dislocation Density Functions
Authors: H Paynter R J , Nowell D
Published: October 2005

There is increasing interest in the use of dislocation methods for stress analysis. In a recent paper, McKellar, Hills, and Sackfield presented a method for obtaining the stress field induced by a triangular area of constant dislocation density. The current paper describes a simplification of the formulae, which is more robust and easier to implement. This new formulation easily extends to any polygon.
Local Reinforcement Effect of a Strain Gauge Installation on Low Modulus Materials
Authors: Ajovalasit A , Zuccarello B
Published: October 2005

The reinforcement effect of electrical resistance strain gauges is well documented in the technical literature. In this paper the local reinforcement effect in tension is studied by using a simple theoretical model by considering a strain gauge mounted on a semi-infinite plate having the same width of the strain gauge and subjected to a uniaxial tension load. Neglecting the effect of the adhesive layer and considering the interface shear stress as an exponential distribution, the proposed model gives a closed-form solution. In detail, this model permits a simple formula to be obtained which allows the user to correct the local reinforcement effect provided that a proper calibration is performed by installing a strain gauge, of the same type as that used on the structure, on a low modulus material. Experimental evidence of the proposed method is shown. Experimental proof of the positive effect of large grid lengths on the local reinforcement effect is also reported.
Approaches to Size-selective Formation of Fullerenes by Cyclization of Highly Reactive Polyyne Chains
Authors: Umeda Rui , Sonoda Motohiro , Wakabayashi Tomonari , Tobe Yoshito
Published: October 2005

As an approach to size-selective formation of fullerenes, we developed a method based on the cyclization of reactive cyclic polyynes which were generated by [2 + 2] cycloreversion of [4.3.2]propellatriene units. This method was proven to work successfully for the first time for the formation of fullerene ions C60+ and C60− in the gas phase. This protocol is useful for generation of a small three-dimensional carbon cluster ion C36− and a large fullerene C78−, as well.
Photochromic Oligothiophenes
Authors: Tanifuji Naoki , Irie Masahiro , Matsuda Kenji
Published: October 2005

New oligothiophenes having a photochromic switching unit were synthesized. Upon irradiation with UV and visible light the oligomers underwent photochromic reactions in solution. The chain length dependence on the photoreactivity was examined to reveal that the reactivity decreased as the chain length gets longer. These molecules can be used as new photoswitching units.
Catalytic Synthesis of α-Hydroxy Ketones Using Organic–Inorganic Hybrid Polymer
Authors: Arai Takayoshi , Takasugi Hitomi , Sato Toru , Noguchi Hiroshi , Kanoh Hirofumi , Kaneko Katsumi , Yanagisawa Akira
Published: October 2005

Oxidation of silyl enolates was found to be smoothly catalyzed by [Cu(bpy)(BF4)2(H2O)2(bpy)]n (bpy = 4,4′-bipyridine) under molecular oxygen, and provided the corresponding α-hydroxy carbonyl compounds in high yield. The insoluble organic–inorganic hybrid polymer was readily recovered by centrifugation after the completion of reaction, and the recovered catalyst could be reused.
Functional characterization of the SOFAdeltaribozyme
Authors: BERGERON LUCIEN JUNIOR , REYMOND CÉDRIC , PERREAULT JEAN-PIERRE
Published: October 2005

Molecular engineering has led to the development of a novel target-dependent riboswitch that increases δribozyme fidelity. This δ ribozyme possesses a specificon/offadapter (SOFA) that switches the cleavage activity fromoff(a “safety lock”) toonsolely in the presence of the desired RNA substrate. In this report, we investigate the influence of both the structure and the sequence of each domain of the SOFA module. Analysis of the cleavage activity, using a large collection of substrates and SOFA-ribozyme mutants, together with RNase H probing provided several insights into the nature of the sequence and the optimal design of each domain of the SOFA module. For example, we determined that (1) the optimal size of the blocker sequence, which keeps the ribozymeoffin the absence of the substrate, is 4 nucleotides (nt); (2) a single nucleotide difference between the substrate and the biosensor domain, which is responsible for the initial binding of the substrate that subsequently switches the SOFA-ribozymeon, is sufficient to cause nonrecognition of the appropriate substrate; (3) the stabilizer, which joins the 5′ and 3′ ends of the SOFA-ribozyme, plays only a structural role; and (4) the optimal spacer sequence, which serves to separate the binding regions of the biosensor and catalytic domain of the ribozyme on the substrate, is from 1 to 5 nt long. Together, these data should facilitate the design of more efficient SOFA-ribozymes with significant potential for many applications in gene-inactivation systems.
Optimizing splinted ligation of highly structured small RNAs
Authors: KURSCHAT WOLFRAM C. , MÜLLER JULIUS , WOMBACHER RICHARD , HELM MARK
Published: October 2005

The synthesis of highly structured small RNAs containing nonstandard nucleotides is of high interest for structural and functional investigations. A general approach is the joining, by T4 DNA ligase-mediated splinted ligation, of two or more RNA fragments, each of which may contain its own set of modified nucleotides. The RNA fragments hybridize with a complementary DNA splint to form a ternary ligation-competent-complex (LCC), which is then turned over by the DNA ligase. We studied the formation of the LCC and its precursors using size exclusion chromatography combined with a fluorescence detector. The spatial proximity of two cyanine-dye-labeled RNA fragments in LCCs was detected by monitoring FRET. An observed correlation of LCC formation and ligation yields suggests the use of long splints to stabilize LCCs. Splint oligos of increasing length, which in general appear to reduce the number of different hybridization intermediate species found in a reaction mixture, were applied to the synthesis by T4-DNA-ligation of two highly structured target molecules, one a 73mer tRNA, the other a 49mer synthetic ribozyme. A stable LCC could be isolated and turned over with > 95% ligation efficiency. In conclusion, the use of long splints presents a generally applicable means to overcome the low propensity of highly structured RNAs for hybridization, and thus to significantly improve ligation efficiencies.
Further evidence that ribavirin interacts with eIF4E
Authors: KENTSIS ALEX , VOLPON LAURENT , TOPISIROVIC IVAN , SOLL CLIFFORD E. , CULJKOVIC BILJANA , SHAO LING , BORDEN KATHERINE L.B.
Published: October 2005

This commentary discusses the recent reports in RNA by Yan and colleagues and Westman and colleagues of the apparent failure of ribavirin to bind to recombinant eIF4E and inhibit 7-methyl guanosine cap-dependent exogenous mRNA translation of cell extracts in vitro. Measuring binding by using affinity chromatography of matrix-immobilized proteins and by using protein emission fluorescence spectroscopy in the presence of nucleotide ligands, as well as limitations of using cell extracts for the assessment of mechanisms of mRNA translation are discussed. Possible reasons for the discordant findings of Yan and colleagues and Westman and colleagues are suggested, and direct observation of the specific binding of ribavirin to eIF4E by using mass spectrometry is presented.
Investor Protection and Judicial Enforcement of Disclosure Regime in Bangladesh: A Critique
Authors: Solaiman S.M.
Published: October 2005

The effectiveness of any law largely depends on the clarity of legal provisions and the activity of their enforcement institutions. Securities law, which is inherently complex, must be unambiguous to be properly applied. Judges and lawyers dealing with securities litigation need to be trained properly to provide justice for the public. Laws governing initial public offerings in Bangladesh are ambiguous in many respects, and the judiciary lacks judges and lawyers sufficiently experienced in this area of law. As a result, judicial enforcement of disclosure requirements in prospectuses appears to have been a difficult task. The administrative enforcement of those requirements is not effective either. In such a situation, potential investors remain market-shy keeping the Bangladesh securities market moribund for years. This paper identifies the drawbacks of the existing mechanism of judicial enforcement of disclosure regime, and provides suggestions for their elimination.
Language and the Law Revisited: An Intellectual History of Contractual Interpretation
Authors: McMeel Gerard
Published: October 2005

Lawyers, like other human beings, are users of language. A facility with words is a desirable attribute for a good lawyer. On the negative side, lawyers attract both distrust and derision for their supposed abuses of ordinary language, such as the deployment of arcane terms, over-elaborate syntax and gobbledegook. The areas in which issues arising from the drafting and interpretation of legal language have attracted most attention to date are the fields of constitutional and statutory law. This is unsurprising given that such documents govern the exercise of significant social and political power. In contrast, this paper addresses issues of construction in private law, and in particular, contractual interpretation.

Ascertaining the meaning of the language deployed by contracting parties constitutes a large proportion of the business of courts and tribunals dealing with commercial disputes. It is tempting to see this as a problem inherent to language due to its flexibility and vagueness, or else to detect a link with the supposed nit-picking mentality of lawyers, always keen to identify an unintended ambiguity in words or loophole in documentation. In practice though, most disputes which have to be resolved by resorting to interpretation are not problems about the meanings of words or ones which require familiarity with grammatical niceties. Rather, they are problems about the application of the language of a contract to the (perhaps unexpected) events which have subsequently transpired. As such they represent an unavoidable source of potential dispute.
Consumer Sovereignty and the Regulatory History of the European Market for Genetically Modified Foods
Authors: Carson Lisa , Lee Robert
Published: October 2005

This paper examines the history of GM laws within four time bands of pre-1997, 1997, 1998–2002 and the 2003–4 reforms. Its first aim is a seemingly modest, though technically difficult one of piecing together the jigsaw that is the regulatory framework for GM food. In the second part of the paper the authors offer a summary of the law immediately prior to the 2003 reforms with a particular emphasis on issues of tracing and labelling that are vital to our theme of consumer choice. This is followed by a third section, and a discussion of the latest round of reforms under the 2003 Regulations, comparing regulatory safeguards before and after the adoption of these regulations. In the fourth and final section of the paper, they assess the extent to which GM regulation, including the latest reforms, can be said to support consumer sovereignty. The authors conclude by questioning whether the highly complex regulatory interventions on tracing and labelling are actually necessary, or whether market incentives to boost sales by making claims about the non-GM status of food might not prove more effective in a European consumer market that is highly aware of the GM issue and prepared to buy or to boycott in accordance with GM content.
Environmental Offences: The Reality of Environmental Crime
Authors: Watson Michael
Published: October 2005

Economic instruments, informational devices, voluntary agreements and command and control regulation are just some of the techniques modern states use to protect the environment. The last of these — command and control — is sometimes dismissed as an increasingly obsolete strategy. It is often alleged that environmental offences are not ‘real’ crimes. They are merely ‘quasi-criminal’ regulatory offences. This article rejects this view. It argues that environmental crime is a serious and growing problem. It examines fly-tipping in the United Kingdom and claims that environmental offenders often have very strong financial incentives to break the law. It claims that fines are currently too low and that serious consideration should be given to the increased use of civil and administrative penalties.
Pompey v Saints: A Case Study in Crowd Segregation
Authors: Frosdick Steve
Published: October 2005

In the United Kingdom, spectator violence at sports events, particularly at football (soccer) matches, is an ancient yet current policing problem. ‘Football hooliganism’ has received considerable academic scrutiny, however the main focus has been on who the hooligans are and why they behave as they do. Other salient issues, for example the policing of spectator violence, have received rather less research attention.

One aspect of such policing involves the physical segregation of rival sets of supporters. This paper is an empirical case study of the crowd segregation arrangements adopted for the 2003–2004 Derby1 matches between Southampton and Portsmouth football clubs. This case study outlines the concept of segregation and describes the two stadiums. It then gives a participant observer account of the segregation arrangements and incidents at the matches. Finally, the paper suggests six more general conclusions based upon the case study. Segregation remains necessary and is best achieved by management rather than physical measures. The proximity of the visiting fans coach (bus) arrival point is important, and it is easier to manage the staggered arrival of small groups of fans. What happens outside the ground has a direct effect on what happens inside and experienced stewards are more effective at ‘policing’ fans than the public police service.
Compstat: The Manager's Perspective
Authors: Vito Gennaro F. , Walsh William F. , Kunselman Julie
Published: October 2005

Originally established by Commissioner William Bratton and his colleagues in the New York City Police Department, Compstat has emerged as a new organisational paradigm in policing. This paper presents data drawn from the written views of police managers from across the USA. The respondents were attending the Administrative Officer's Course at the Southern Police Institute of the University of Louisville, Kentucky. During the course of their studies, they read several works on Compstat, including Silverman's (1999) work, NYPD Battles Crime. Content analysis of their written comments reveals the strengths and weaknesses that they associate with the Compstat model.
Expert Testimony in the Dock
Authors: Wilson Adam
Published: October 2005

This article focuses predominantly on the recent miscarriages of justice in the cases of Angela Cannings and Sally Clark. The article identifies possible causes of error in trials involving expert testimony. It is suggested that admission of scientific evidence may inevitably elicit such miscarriages of justice. In order to reduce their frequency, however, experts need training in both scientific and forensic methodology. The science community must also ensure vigilance against scientific dogma. The cases show that responsibility does not lie solely at the feet of expert witnesses. Advocates need training in how to deal with expert testimony. Finally, the use of the jury in complex scientific trials is considered and approved.
Thyroid Function and Prevalence of Anti-Thyroperoxidase Antibodies in a Population with Borderline Sufficient Iodine Intake: Influences of Age and Sex
Authors: Hoogendoorn Elizabeth H , Hermus Ad R , de Vegt Femmie , Ross H Alec , Verbeek Andre LM , Kiemeney Lambertus ALM , Swinkels Dorine W , Sweep Fred CGJ , den Heijer Martin
Published: October 2005

Background: We present a large European population-based study of thyroid function, performed in a population with longstanding borderline sufficient iodine intake.

Methods: The Nijmegen Biomedical Study is a population-based survey conducted in the eastern part of The Netherlands. Randomly selected inhabitants received a postal questionnaire on lifestyle and medical history, which was filled out by 9371 individuals (41.7%). We measured serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), and anti-thyroperoxidase antibodies (TPOAbs) in 6434 responders. A reference population of 5167 individuals was selected by excluding those at risk for thyroid disease.

Results: Overt thyrotoxicosis was found in 0.4% of the total population and subclinical thyrotoxicosis in 0.8%. Overt hypothyroidism was found in 0.4% and subclinical hypothyroidism in 4.0%. In individuals older than 60 years, mean FT4 concentrations increased with age. Mean TSH decreased with age, from 1.46 mIU/L at 18–24 years to 1.07 mIU/L after 85 years. The mean TSH in the total population did not differ from the mean TSH in the reference population; the exclusion of those at risk for thyroid disease, however, lowered the upper limit of the TSH reference interval considerably. In the total population, 8.6% of males and 18.5% of females had positive TPOAbs. The presence of TPOAbs was associated with abnormally high and low TSH concentrations.

Conclusion: In inhabitants of the eastern part of The Netherlands, serum TSH gradually decreases with age, whereas after age 60, serum FT4 increases, possibly because of the development of thyroid autonomy after longstanding borderline sufficient iodine intake.
Population Differences in the Polyalanine Domain and 6 New Mutations in HLXB9 in Patients with Currarino Syndrome
Authors: Garcia-Barceló Mercè , So Man-ting , Lau Danny Ko-chun , Leon Thomas Yuk-yu , Yuan Zheng-wei , Cai Wei-song , Lui Vincent Chi-hang , Fu Ming , Herbrick Jo-Anne , Gutter Emily , Proud Virginia , Li Long , Pierre-Louis Jacqueline , Aleck Kirk , van Heurn Ernest , Belloni Elena , Scherer Stephen W , Tam Paul Kwong-hang
Published: October 2005

Background: The combination of partial absence of the sacrum, anorectal anomalies, and presacral mass constitutes Currarino syndrome (CS), which is associated with mutations in HLXB9.

Methods: We analyzed 5 CS families and 6 sporadic cases for HLXB9 mutations by direct sequencing. Potentially pathologic expansions of HLXB9 GCC repeats were analyzed in patients, 4 general populations [Chinese, Japanese, Yoruba, and Centre du Etude Polymorphisme Human (CEPH)] from the HapMap project, and 145 healthy Chinese.

Results: We identified 6 novel mutations affecting highly conserved residues (Ser185X, Trp215X, Ala26fs, Ala75fs, Met1Ile, and Arg273Cys). GCC allele and genotype distributions showed marked statistically significant differences. (GCC)11 was the most common allele overall; its frequency ranged from 90% in CEPH to 68% in Yoruba and 50% in Chinese and Japanese populations. (GCC)9 was almost as common as (GCC)11 in Chinese and Japanese populations, whereas its frequency was <10% in Yoruba and CEPH populations. The Yoruba population had the highest frequency of the largest alleles [(GCC)12 and (GCC)13], which were almost absent in the other groups.

Conclusions: Lack of HLXB9 mutations in some patients and the presence of variable phenotypes suggest DNA alterations in HLXB9 noncoding regions and/or in other genes encoding HLXB9 regulatory molecules or protein partners. If HLXB9, like other homeobox genes, has a threshold beyond which triplet expansions are pathologic, those populations enriched with larger alleles would be at a higher risk. The data illustrate the importance of ethnicity adjustment if these polymorphic markers are to be used in association studies.
Normalizers of space groups: A useful tool in crystal-structure description, comparison and determination
Authors: Koch Elke , Fischer Werner
Published: October 2005

After an illustrative example for the ‘symmetry of symmetry’ the group-theoretical concept of normalizers is introduced by a series of definitions. Subsequently, this concept is applied to space groups for which Euclidean and affine normalizers are discussed. Their implications on point configurations, Wyckoff positions and coordinate descriptions of crystal structures are explained. The derivation of all equivalent descriptions of a crystal structure with the aid of the tables of normalizers given in the International Tables for Crystallography, Vol. A is elucidated by several examples.
Opechowski's magic relations
Authors: Kopský Vojtěch
Published: October 2005

Transformation properties of tensors under the action of the full magnetic group SO(3) × E

o
are specified by the intrinsic symmetry which defines how the tensor transforms under the action of the proper rotation group SO(3) and by their parity which defines how the tensor transforms under the action of the group of inversions E

o
= {e, i, e′, i′}, where i denotes the space inversion, e′ the magnetic inversion and i′ = i.e′ their combination. There exist therefore four types of tensors to each intrinsic symmetry whose transformation properties under the group SO(3) are identical while their transformation under the group E

o
determines their parities with respect to the three inversions. As a result of this separation, transformation properties of tensors of the same intrinsic symmetry under the action of magnetic groups of the same oriented Laue class are strongly correlated by relations for which we propose the name Opechowski's magic relations in homage to late Prof. Opechowski. The origin of these relations is explained and tables which describe them are presented. It is found, in particular, that the number of different forms of tensor decompositions under the action of groups of oriented Laue class of magnetic point groups equals the number of one-dimensional real irreducible representations of the proper rotation group which generates the Laue class. Accordingly, there exists also the same number of allowed forms of tensors which do not vanish.
Topological transformations performed on nets via their quotient graphs
Authors: Eon Jean-Guillaume
Published: October 2005

Topological transformations in nets resulting from the insertion or deletion of edges or vertices are analyzed through the analogous operations performed on their quotient graphs. The role of strong rings and cages of the net is emphasized. It is shown that closed trails of the oriented quotient graph define the topology of 3-periodic nets derived from regular, vertex and edge transitive, 4-periodic minimal nets.
Optimal ball packings for crystallographic groups of the cubic crystal system and their Dirichlet-Voronoi cells
Authors: Prok István , Szirmai Jenö
Published: October 2005

In this paper we look for densest ball packings of Euclidean space E3 to given symmetry groups. We restrict our investigation to the 36 space groups of the cubic crystal system, and we search for only those packings where the group acts simply transitively on the balls. In order to find the centre of a ball and its radius for the case of an optimal packing we will apply an algorithm and the corresponding computer program, which was developed by the second author [21, 12]. In the list of our results we will give the coordinates of the ball centre and the radius, moreover, we will compute the density of the optimal packing and display the corresponding D-V cell for each space group above (see also [14, 15]).
Applications of injectable polymeric implants for protein and DNA delivery
Authors: Eliaz Rom E. , Kost Joseph
Published: October 2005

We developed a monolithic protein and gene delivery system where an implant is formed following injection to the site of need. This implant can be used for the controlled release of small molecules, proteins, and genes over a 2‐month period. As an example of the protein delivery system, sustained release of the soluble tumor necrosis factor (TNF) receptor (sp55‐R) from the injectable implant was used as a long‐term protection device against the harmful pathological effects of TNF. When the system is used to release DNA, a robust and prolonged gene expression at the site of need can be obtained. Furthermore, when the system was used for controlled delivery of the appropriate plasmid DNA, it resulted in the sustained expression of luciferase, the persistent appearance of secreted alkaline phosphatase in the serum, and small blood vessel formation in the vicinity of the implant from the delivery of the development endothelial locus‐1 gene. This delivery system involves simple preparation procedures and can be injected directly into the site, and therefore should be a useful approach to drug delivery, protein therapy, and plasmid‐based gene transfer for vaccination and tissue engineering.
Hypoxia and Serum Deprivation-Induced Apoptosis in Mesenchymal Stem Cells
Authors: Zhu Weiquan , Chen Jinghai , Cong Xiangfeng , Hu Shengshou , Chen Xi
Published: October 2005

In recent years, the understanding that regeneration progresses at the level of the myocardium has placed stem cell research at the center stage in cardiology. Despite an increasing interest in cell transplant research, relatively little is known about the biochemical regulation of the stem cell itself after transplantation into an ischemic heart. We demonstrated here, using rat mesenchymal stem cells (MSCs), that cells undergo caspase-dependent apoptosis in response to hypoxia and serum deprivation (SD), which are both components of ischemia in vivo. In particular, the treated cells exhibited mitochondrial dysfunction, including cytochrome C release, loss in ΔΨm, and Bax accumulation, but in a p53-independent manner. Although the cells treated by hypoxia/SD possess the activity of caspase-8, zIEDT-fmk, a specific caspase-8 inhibitor, failed to inhibit cell apoptosis induced in our system. Taken together, our findings indicate that MSCs are sensitive to hypoxia/SD stimuli that involve changes in mitochondrial integrity and function but are potentially independent of caspase-8.
Evaluation of Long‐Term Implant Success
Authors: Schwartz‐Arad Devorah , Herzberg Ran , Levin Liran
Published: October 2005

Implant success criteria, regarding marginal bone loss and other parameters, were first suggested in 1986 and today are still frequently referred to as the gold standard for implant success. However, according to the recent abundance of data on marginal bone loss and a better understanding of bone and soft tissue behavior around the implant neck and body, these criteria are inaccurate for the wide variety of implant systems. The purpose of this article is to review some of the relevant literature regarding marginal bone loss and to propose guidelines for a novel approach to evaluate the long‐term success of implants regarding marginal bone loss. Four hypothetical patterns of implant marginal bone loss after the first year are suggested: a low‐rate marginal bone loss over the years (Albrektsson's pattern); low‐rate marginal bone loss in the first few years followed by a rapid loss of bone support; high‐rate marginal bone loss in the first few years followed by almost no bone loss; and continuous high‐rate marginal bone loss leading to a complete loss of bone support.
Gingipain‐Specific IgG in the Sera of Patients With Periodontal Disease Is Necessary for Opsonophagocytosis of Porphyromonas gingivalis
Authors: Gibson Frank C. , Savelli Juan , Van Dyke Thomas E. , Genco Caroline Attardo
Published: October 2005

Background: Porphyromonas gingivalis is a primary etiologic agent of generalized aggressive periodontitis (GAgP), and gingipains, a group of cysteine proteinases, are critical virulence factors expressed by this organism. GAgP patients develop specific antibodies to gingipains; however, the function of these antibodies in the clearance of P. gingivalis infection is poorly understood.

Methods: In this study, we defined the levels of gingipain‐specific antibodies in GAgP patient sera and examined the ability of gingipain‐specific antibodies to facilitate opsonophagocytosis of P. gingivalis by human polymorphonuclear leukocytes (PMNs) using a fluorescent phagocytosis assay.

Results: GAgP patient sera possessed elevated levels of P. gingivalis‐, arginine‐gingipain (Rgp)A‐, RgpB‐, and lysine‐gingipain (Kgp)‐specific IgG (Kgp > RgpA > P. gingivalis > RgpB). Adsorption of GAgP sera with P. gingivalis whole organisms, RgpA, RgpB, and Kgp conjugated to sepharose beads reduced opsonophagocytosis of P. gingivalis by PMNs.

Conclusions: Our studies demonstrate that GAgP patient sera possess elevated levels of P. gingivalis‐ and gingipain‐specific IgG. Furthermore, we show that gingipain antibodies promote uptake of P. gingivalis by PMNs, and our data suggest that gingipain‐specific antibodies may be important for the control of P. gingivalis infections.
Regenerative Potential of Platelet‐Rich Plasma Added to Xenogenic Bone Grafts in Peri‐Implant Defects: A Histomorphometric Analysis in Dogs
Authors: Sánchez Andrés R. , Sheridan Phillip J. , Eckert Steven E. , Weaver Amy L.
Published: October 2005

Background: The purpose of this investigation was to evaluate the regenerative influence of platelet‐rich plasma (PRP) added to xenogenic bone grafts on bone histomorphometric parameters in a dog model.

Methods: Ninety endosseous dental implants were inserted in the mandibles of nine hound dogs. Mesial and distal 3‐wall peri‐implant defects were surgically created adjacent to the implants. Defects were randomly assigned to three groups: demineralized freeze dried bone with platelet‐rich plasma (DFDB + PRP), DFDB alone, and no treatment (NT). Animals were sacrificed at 1, 2, and 3 months according to a previously established randomization schedule, and specimens were subjected to histomorphometric analysis. Percentages of bone area inside the implant threads (BiIT), bone‐to‐implant contact (BIC), and bone area outside implant threads (BoIT) were recorded. Treatment effects were evaluated using analysis of variance models.

Results: The effect of the three treatments on the outcome measures did not differ significantly by healing time (P >0.05 for the healing time by treatment interaction). However, the average (standard deviation) percentage of BIC and BoIT was significantly different between the treatment groups. In particular, the average percentage of BIC differed between peri‐implant defects treated with DFDB + PRP (33.8% [11.0]) and those treated with DFDB alone (28.5% [10.8]; P = 0.042), as well as those in the NT group (27.9% [11.0]; P = 0.024). Furthermore, the average percentage of BoIT differed significantly between defects treated with DFDB + PRP compared to defects in the NT group (51.6% [12.2] versus 43.3% [10.3]; P = 0.005). There was borderline evidence to suggest that the average percentage of BiIT and BIC was significantly different depending on the length of the healing time (P = 0.054 and P = 0.085, respectively).

Conclusion: This study found that the addition of PRP to xenogenic bone grafts demonstrated a low regenerative potential in this animal model.
The Effects of Three Oral Sprays on Plaque and Gingival Inflammation
Authors: Bozkurt F. Yesim , Öztürk Mine , Yetkin Zuhal
Published: October 2005

Background: The aim of this clinical trial was to compare the effects of three oral sprays containing chlorhexidine (CHX), benzydamine hydrochloride (B‐HCl), and CHX plus B‐HCl (CHX/B‐HCl) on plaque and gingivitis.

Methods: Fifty‐one periodontally healthy volunteers, randomly divided into three spray groups, refrained from all mechanical oral hygiene measures for 7 days and, instead, used one of the randomly assigned sprays twice daily. The plaque index (PI), gingival index (GI), and gingival bleeding time index (GBTI) were assessed at days 0 and 7. Side effects were also evaluated.

Results: In all groups, PI, GI, and GBTI showed significant increases from the baseline to day 7. There were no significant side effects for B‐HCl spray and CHX spray at day 7, but, for CHX/B‐HCl, burning sensation significantly increased from the baseline. For all parameters, there were significant differences between B‐HCl and CHX/B‐HCl and between B‐HCl and CHX, but no significant differences were observed between CHX/B‐HCl and CHX. In addition, a significant difference was found between CHX/B‐HCl and CHX with regard to burning sensation.

Conclusions: These results indicate that both CHX and CHX/B‐HCl sprays have equal clinical effectiveness, but only B‐HCl spray has less anti‐plaque and anti‐gingivitis effects. Furthermore, CHX/B‐HCl spray causes more side effects.
Involvement of Porphyromonas gingivalis fimA Genotype in Treatment Outcome Following Non‐Surgical Periodontal Therapy
Authors: Fujise Osamu , Miura Mayumi , Hamachi Takafumi , Maeda Katsumasa
Published: October 2005

Background: Porphyromonas gingivalis is considered a critical pathogen in periodontal diseases. It is classified into six genotypes based on diversity of the fimA gene encoding fimbrillin. The present study evaluated the involvement of the fimA genotype in treatment outcome following non‐surgical periodontal therapy.

Methods: Chronic periodontitis patients were enrolled in this study; all received clinical and microbiological examinations at baseline. The detection of subgingival species and identification of P. gingivalis fimA genotypes were performed using polymerase chain reaction based methods. In total, 160 P. gingivalis positive sites with bleeding on probing (BOP) and a probing depth of ≥4 mm were accepted. They were followed up after scaling and root planing.

Results: Longitudinal investigation indicated that fimA type I positive sites at baseline were followed by a significantly higher frequency of persistent BOP after treatment than type I negative sites (51.6% versus 27.9%), while types Ib and II were not. Type I positive sites also showed more persistence of Tannerella forsythensis and P. gingivalis after treatment than type I negative sites. In post‐treatment investigation, type I positive sites showed higher frequencies of BOP and T. forsythensis detection than type I negative sites (77.8% versus 43.5% and 100% versus 76.1%, respectively).

Conclusions: BOP in initially type I positive sites showed little improvement with treatment, and the combined persistence of fimA type I and T. forsythensis seemed to be involved in this poor treatment outcome. The present study demonstrated the potential of P. gingivalis fimA type I as a predictor of persistent BOP after treatment.
Periodontal Regeneration With Peptide‐Enhanced Anorganic Bone Matrix in Particulate and Putty Form in Dogs
Authors: Vastardis Sotirios , Yukna Raymond A. , Mayer Elizabeth T. , Atkinson Brent L.
Published: October 2005

Background: Peptide‐enhanced (using the peptide 15 [P‐15] synthetic peptide) anorganic bone matrix (ABM) particulate (PPart) grafts have demonstrated clinical and histologic success in human periodontal defects. Dispersion of ABM/P‐15 in sodium hyaluronate carrier (PPutty) improves the handling properties of the graft material. The healing of ABM/P‐15 particulate and ABM/P‐15 putty was compared in critical‐sized fenestration defects in 16 mongrel dogs.

Methods: After full thickness flap reflection, 7 mm diameter fenestrations were made with a trephine in the mid‐root of both maxillary canines in each dog. Bone, periodontal ligament, and cementum were removed as completely as possible with hand root planing within the trephine‐produced notches. By random allocation, each defect was filled with PPart or PPutty, and the flaps were closed with sutures. One dog contributing two defects served as a negative control. Block sections were retrieved at 3 and 8 weeks for histologic processing. Three 6‐μ step serial sections in the center of the defects were used for analysis. Parameters measured included the original length of the wound, linear amount of periodontal regeneration including new cementum, bone and connective tissue, and area measurements of new bone and remaining particles. PPutty and PPart results were compared for significant differences using the Wilcoxon rank sum test.

Results: Clinical healing was uneventful in all cases. There was no evidence of inflammation or adverse tissue reactions with either material. The controls showed minimal regeneration at the periphery of the defect. Histomorphometric evaluation of the grafted defects revealed the following: at 3 weeks, there was minimal new bone formation (occupying 4.2% of the grafted area for the PPutty and 1.2% for the PPart). The grafted particles occupied 21.2% and 35.6% of the area for the PPutty and PPart, respectively (P = 0.039). At 8 weeks, there was a tendency for greater new bone formation compared to 3 weeks with both materials. There was significantly more new bone with the PPutty (49.3%) compared to the PPart (14.8%) (P = 0.045). The grafted particles occupied 7.9% and 17% of the grafted area for the PPutty and PPart, respectively (no significant difference). There were no significant differences for any of the linear measurements. ABM/P‐15 PPutty had superior handling characteristics.

Conclusions: Both ABM/P‐15 materials yielded satisfactory healing and resulted in the greater regeneration of fenestration defects in dogs at 8 weeks compared to controls. In addition, AMB/P‐15 putty resulted in more bone formation compared to ABM/P‐15 particulate.
Biological Factors Involved in the Osseointegration of Oral Titanium Implants With Different Surfaces: A Pilot Study in Minipigs
Authors: Schierano Gianmario , Canuto Rosa Angela , Navone Roberto , Peirone Bruno , Martinasso Germana , Pagano Marco , Maggiora Marina , Manzella Carlo , Easton Michael , Davit Annalisa , Trombetta Antonella , Amedeo Stefano , Biolatti Bartolomeo , Carossa Stefano , Preti Giulio
Published: October 2005

Background: The stability of titanium implants is determined by the rigid load‐bearing connections that are formed by the bone, a process that involves a complex network of cells, pro‐ and anti‐inflammatory mediators, and growth factors. The osseointegration processes at the interfaces of machined and porous implants were studied using molecular and histological techniques.

Methods: Two machined and two porous titanium implants were inserted into the tibiae of four minipigs. The animals were sacrificed at 15, 30, 60, and 90 days post‐implantation. The levels of bone morphogenetic protein (BMP)‐4, transforming growth factor (TGF)‐β1, and tumor necrosis factor (TNF)‐α were quantified in the peri‐implant osseous samples. The levels of interleukin (IL)‐1β, IL‐6, IL‐10, and TNF‐α in the serum were also assessed.

Results: Histomorphological analysis showed evidence of bone ossification around the porous implant at 60 days. Surrounding the machined implants, highly sclerotic fibrous pads started the healing response at 90 days, and the levels of TGF‐β1 and BMP‐4 began to increase at 60 days, at which time bone ossification around the porous implants was already evident. TNF‐α was not present in the bone next to the implants. The serum levels of cytokines IL‐1β, IL‐6, and IL‐10 were not increased. The serum level of TNF‐α increased during the healing process.

Conclusions: We observed that the levels of BMP‐4 and TGF‐β1, which play essential roles in the osteogenesis process, increased earlier around the porous implants than around the machined implants. Similarly, the ossification process was initiated earlier at the surfaces of the porous implants than at the surfaces of the machined implants.