bluuebunny/crossref_metadata_2025 huggingface dataset:
ANTIBIOTICS TARGETING RIBOSOMES: Resistance, Selectivity, Synergism, and Cellular Regulation
Authors: Yonath Ada
Published: June 2005

▪ Abstract  Antibiotics target ribosomes at distinct locations within functionally relevant sites. They exert their inhibitory action by diverse modes, including competing with substrate binding, interfering with ribosomal dynamics, minimizing ribosomal mobility, facilitating miscoding, hampering the progression of the mRNA chain, and blocking the nascent protein exit tunnel. Although the ribosomes are highly conserved organelles, they possess subtle sequence and/or conformational variations. These enable drug selectivity, thus facilitating clinical usage. The structural implications of these differences were deciphered by comparisons of high-resolution structures of complexes of antibiotics with ribosomal particles from eubacteria resembling pathogens and from an archaeon that shares properties with eukaryotes. The various antibiotic-binding modes detected in these structures demonstrate that members of antibiotic families possessing common chemical elements with minute differences might bind to ribosomal pockets in significantly different modes, governed by their chemical properties. Similarly, the nature of seemingly identical mechanisms of drug resistance is dominated, directly or via cellular effects, by the antibiotics' chemical properties. The observed variability in antibiotic binding and inhibitory modes justifies expectations for structurally based improved properties of existing compounds as well as for the discovery of novel drug classes.
EUKARYOTIC TRANSLESION SYNTHESIS DNA POLYMERASES: Specificity of Structure and Function
Authors: Prakash Satya , Johnson Robert E. , Prakash Louise
Published: June 2005

▪ Abstract  This review focuses on eukaryotic translesion synthesis (TLS) DNA polymerases, and the emphasis is on Saccharomyces cerevisiae and human Y-family polymerases (Pols) η, ι, κ, and Rev1, as well as on Polζ, which is a member of the B-family polymerases. The fidelity, mismatch extension ability, and lesion bypass efficiencies of these different polymerases are examined and evaluated in the context of their structures.One major conclusion is that, despite the overall similarity of basic structural features among the Y-family polymerases, there is a high degree of specificity in their lesion bypass properties. Some are able to bypass a particular DNA lesion, whereas others are efficient at only the insertion step or the extension step of lesion bypass. This functional divergence is related to the differences in their structures. Polζ is a highly specialized polymerase specifically adapted for extending primer termini opposite from a diverse array of DNA lesions, and depending upon the DNA lesion, it contributes to lesion bypass in a mutagenic or in an error-free manner. Proliferating cell nuclear antigen (PCNA) provides the central scaffold to which TLS polymerases bind for access to the replication ensemble stalled at a lesion site, and Rad6-Rad18-dependent protein ubiquitination is important for polymerase exchange.
Significance of Anti-HBc in the Absence of Other Hepatitis B Markers in a College-Aged Population
Authors: Stancoven K. , Hwang L.-Y. , Troisi C.L.
Published: June 2005

A study of 291 college students in the Houston (Tex., USA) area was performed to determine the relationship between alanine aminotransferase (ALT) level and antibodies to the hepatitis B virus (HBV) core antigen (anti-HBc) in the absence of other HBV markers (referred to as isolated anti-HBc). Participants were drawn from three groups: those positive only for anti-HBc (cases), those positive for hepatitis B surface antigen, a marker of acute/chronic HBV infection (control group 1), and those with no previous exposure to the HBV (control group 2). There were no significant differences between the groups in percentages of subjects with an elevated ALT level. The mean ALT level from active HBV infections was highest with HBV-negative controls having the lowest mean ALT concentration (p = 0.06), but no significant differences were found between ALT levels of those with isolated anti-HBc and either control group. This study may further aid in determining the presence of any liver damage when testing positive only for the antibodies to HBc.
Differential Astrocyte Response to Theiler’s Murine Encephalomyelitis Virus Infection
Authors: Pozner Roberto G. , Berría Maria I. , Negrotto Soledad , Schattner Mirta , Gómez Ricardo M.
Published: June 2005

Objectives: We aimed to address if selective astrocyte apoptosis is involved in the lack of murine demyelinating disease following infection by the L*-1 variant of Theiler’s virus. In addition, we investigated whether L*-1-infected astrocytes were able to selectively express molecules whose effects would play a role as pathogenic factors. Methods: Murine cultured astrocytes were infected with two Theiler viruses, the DA strain and the mutated DA variant L*-1, which does not synthesize the out of frame L* protein. Results: Neither DA nor L*-1 provoked apoptosis, although they replicated in astrocytes inducing GFAP and iNOS expression, as well as subsequent nitric oxide production. In addition, both viruses caused an enhanced expression of ICAM-1, VCAM-1 and decay accelerating factor (DAF). In this connection, values of VCAM-1 and DAF induced by L*-1 were higher and lower, respectively, than those induced by DA. Conclusions: Since no apoptosis was found, such mechanism would not be involved in the lack of TMEV-induced demyelinating disease by L*-1. In contrast, selective expression of VCAM-1 and DAF molecules induced by L*-1 could have a role in virus clearance from the central nervous system.
Activation of Interferon-Stimulated Response Element in Huh-7 Cells Replicating Hepatitis C Virus Subgenomic RNA
Authors: Pai Mirabel , Prabhu Ramesh , Panebra Alfredo , Nangle Sarah , Haque Salima , Bastian Frank , Garry Robert , Agrawal Krishna , Goodbourn Steve , Dash Srikanta
Published: June 2005

Interferon-alpha (IFNα) binds to receptors on the cell surface, which initiate a cascade of signal transduction pathways that leads to transcription of selected genes. This transduction pathway involves binding of transcription factors to a common cis-acting DNA sequence called IFN-stimulated response element (ISRE). To test whether these signaling pathways are functional in hepatitis C virus (HCV)-replicating cells, we studied the regulation of ISRE-mediated transcription of firefly luciferase gene in stable replicon cell lines. A plasmid construct was prepared (pISRELuc) which contains four tandem repeats of 9-27 ISRE sequences positioned directly upstream of the herpes virus 1 thymidine kinase promoter TATA box that drives the expression of firefly luciferase. Regulation of ISRE-mediated expression of firefly luciferase by IFNα was studied by transfecting this clone into Huh-7 cells replicating HCV subgenomic HCV RNA. The significance of ISRE-mediated transcriptional activation was studied in a replicon cell line by pretreatment of cells with actinomycin D, which inhibits cellular DNA-dependent RNA transcription. IFN treatment activates ISRE-mediated expression of luciferase, indicating that this pathway is functional in Huh-7 cells. Activation of ISRE-mediated transcription of luciferase is relatively high in two Huh-7 stable cell lines replicating HCV subgenomic RNA. Inhibition of ISRE-mediated transcription of luciferase by actinomycin D also makes HCV replication totally resistant to IFNα. These in vitro studies suggest that activation of IFN-inducible genes is important in mounting a successful antiviral response against HCV.
Varicella-Zoster Virus Infection Influences Expression and Organization of Actin and α-Tubulin but Does Not Affect Lamin A and Vimentin
Authors: Kuhn Michaela , Desloges Nathalie , Rahaus Markus , Wolff Manfred H.
Published: June 2005

Objective: The aim of this study was to examine the effects of varicella-zoster virus (VZV) infection on the cytoskeletal components actin, lamin A, α-tubulin and vimentin. Methods: The expression patterns of these four proteins during VZV infection were studied by Northern and Western blotting. The filaments were also studied in their cellular environment by immunofluorescence using confocal microscopy. Treatment with nocodazole and cytochalasin B was performed to examine the effects of the destruction of actin or tubulin networks on the VZV replicative cycle. Results: The amounts of the mRNAs of actin, lamin A, α-tubulin and vimentin decreased slightly at 48 h post infection (p.i.) with VZV. The cellular content of the lamin A protein appeared to remain stable during the time period analyzed, whereas the amounts of actin, α-tubulin and vimentin decreased slightly at 24 h p.i. until the end of the viral cycle. Rearrangement of microfilaments and microtubules was observed at 24 h p.i. The addition of nocodazole or cytochalasin B decreased viral replication. Conclusions: During the VZV replicative cycle, tubulin and actin networks undergo significant changes including fiber elongation. If destroyed intentionally, viral replication is diminished, suggesting that these systems are vital for an efficient infection and viral replication.
Comparative Study of Tolerance between Unmodified and High Doses of Chemically Modified Allergen Vaccines of Dermatophagoides pteronyssinus
Authors: Casanovas Miguel , Fernández-Caldas Enrique , Alamar Remedios , Basomba Antonio
Published: June 2005

Background: The physiochemical modification of allergens to reduce allergenicity, while retaining immunogenicity, provides a chance for the administration of higher doses of immunotherapy, with a decreased risk of systemic reactions. Objective: To evaluate the safety of doses of depigmented glutaraldehyde-polymerized vaccine of Dermatophagoides pteronyssinus increasing those used in normal clinical conditions in comparison with regular doses of a non-modified vaccine. Materials and Methods: The study was double-blind, parallel and included two patient groups. Twenty-three patients were treated weekly during 9 visits for the build-up phase, followed by 2-weekly maintenance doses (a total of 11 injections per patient). Eleven patients (mean age 22 years) received immunotherapy with the standardized modified vaccine. The maximum dose used was the result of depigmenting and polymerizing 100 times the maximum dose used with the native extract. The maximum concentration used was 990 µg/ml of freeze-dried material. Twelve patients (mean age 24 years) received a standardized, unmodified allergenic extract. The maximum concentration used was 70 µg of freeze-dried material/ml, with a potency of 10 HEPL/ml. The tolerance was evaluated recording all the side reactions related to immunotherapy and graded following the recommendations of the European Academy of Allergology and Clinical Immunology. Results: In both groups, all immediate local reactions were clinically not relevant. Patients treated with the native extract experienced 42 local immediate and 24 delayed reactions (1 of them had a diameter >10 cm), whereas patients treated with the modified extract experienced 30 local immediate and 21 delayed reactions (2 of them had a diameter >10 cm). Four systemic reactions in 2 patients, 1 immediate of grade 1 and 3 delayed of grade 2 were reported in the group treated with native extract and 1 delayed of grade 2 in the group treated with the modified preparation. Conclusions: The modified extract of D. pteronyssinus, used at concentrations which are 10 times higher than those regularly administered in clinical practice, demonstrated to be safe to treat D. pteronyssinus-sensitive patients. The major ity of the local reactions (immediate and delayed) were clinically not relevant (diameter <5 cm). No systemic reactions of grade 3 or 4 were noted.
Infective Endocarditis
Authors: Baddour Larry M. , Wilson Walter R. , Bayer Arnold S. , Fowler Vance G. , Bolger Ann F. , Levison Matthew E. , Ferrieri Patricia , Gerber Michael A. , Tani Lloyd Y. , Gewitz Michael H. , Tong David C. , Steckelberg James M. , Baltimore Robert S. , Shulman Stanford T. , Burns Jane C. , Falace Donald A. , Newburger Jane W. , Pallasch Thomas J. , Takahashi Masato , Taubert Kathryn A.
Published: June 2005

Background—

Despite advances in medical, surgical, and critical care interventions, infective endocarditis remains a disease that is associated with considerable morbidity and mortality. The continuing evolution of antimicrobial resistance among common pathogens that cause infective endocarditis creates additional therapeutic issues for physicians to manage in this potentially life-threatening illness.

Methods and Results—

This work represents the third iteration of an infective endocarditis “treatment” document developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It updates recommendations for diagnosis, treatment, and management of complications of infective endocarditis. A multidisciplinary committee of experts drafted this document to assist physicians in the evolving care of patients with infective endocarditis in the new millennium. This executive summary addresses the major points detailed in the larger document that contains more extensive background information and pertinent references. For the first time, an evidence-based scoring system that is used by the American College of Cardiology and the American Heart Association was applied to treatment recommendations. Tables also have been included that provide input on the use of echocardiography during diagnosis and treatment of infective endocarditis, evaluation and treatment of culture-negative endocarditis, and short-term and long-term management of patients during and after completion of antimicrobial treatment. To assist physicians who care for children, pediatric dosing was added to each treatment regimen.

Conclusions—

The recommendations outlined in this summary should assist physicians in all aspects of patient care in the diagnosis, medical and surgical treatment, and follow-up of infective endocarditis, as well as management of associated complications. Clinical variability and complexity in infective endocarditis, however, dictate that these guidelines be used to support and not supplant physician-directed decisions in individual patient management.
Infective Endocarditis
Authors: Baddour Larry M. , Wilson Walter R. , Bayer Arnold S. , Fowler Vance G. , Bolger Ann F. , Levison Matthew E. , Ferrieri Patricia , Gerber Michael A. , Tani Lloyd Y. , Gewitz Michael H. , Tong David C. , Steckelberg James M. , Baltimore Robert S. , Shulman Stanford T. , Burns Jane C. , Falace Donald A. , Newburger Jane W. , Pallasch Thomas J. , Takahashi Masato , Taubert Kathryn A.
Published: June 2005

Background—

Despite advances in medical, surgical, and critical care interventions, infective endocarditis remains a disease that is associated with considerable morbidity and mortality. The continuing evolution of antimicrobial resistance among common pathogens that cause infective endocarditis creates additional therapeutic issues for physicians to manage in this potentially life-threatening illness.

Methods and Results—

This work represents the third iteration of an infective endocarditis “treatment” document developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It updates recommendations for diagnosis, treatment, and management of complications of infective endocarditis. A multidisciplinary committee of experts drafted this document to assist physicians in the evolving care of patients with infective endocarditis in the new millennium. This extensive document is accompanied by an executive summary that covers the key points of the diagnosis, antimicrobial therapy, and management of infective endocarditis. For the first time, an evidence-based scoring system that is used by the American College of Cardiology and the American Heart Association was applied to treatment recommendations. Tables also have been included that provide input on the use of echocardiography during diagnosis and treatment of infective endocarditis, evaluation and treatment of culture-negative endocarditis, and short-term and long-term management of patients during and after completion of antimicrobial treatment. To assist physicians who care for children, pediatric dosing was added to each treatment regimen.

Conclusions—

The recommendations outlined in this update should assist physicians in all aspects of patient care in the diagnosis, medical and surgical treatment, and follow-up of infective endocarditis, as well as management of associated complications. Clinical variability and complexity in infective endocarditis, however, dictate that these guidelines be used to support and not supplant physician-directed decisions in individual patient management.
Test Construction for Cognitive Diagnosis
Authors: Henson Robert , Douglas Jeff
Published: June 2005

Although cognitive diagnostic models (CDMs) can be useful in the analysis and interpretation of existing tests, little has been developed to specify how one might construct a good test using aspects of the CDMs. This article discusses the derivation of a general CDM index based on Kullback-Leibler information that will serve as a measure of how informative an item is for the classification of examinees. The effectiveness of the index is examined for items calibrated using the deterministic input noisy “and” gate model (DINA) and the reparameterized unified model (RUM) by implementing a simple heuristic to construct a test from an item bank. When compared to randomly constructed tests from the same item bank, the heuristic shows significant improvement in classification rates.
Monte Carlo Test Assembly for Item Pool Analysis and Extension
Authors: Belov Dmitry I. , Armstrong Ronald D.
Published: June 2005

A new test assembly algorithm based on a Monte Carlo random search is presented in this article. A major advantage of the Monte Carlo test assembly over other approaches (integer programming or enumerative heuristics) is that it performs a uniform sampling from the item pool, which provides every feasible item combination (test) with an equal chance of being built during an assembly. This allows the authors to address the following issues of pool analysis and extension: compare the strengths and weaknesses of different pools, identify the most restrictive constraint(s) for test assembly, and identify properties of the items that should be added to a pool to achieve greater usability of the pool. Computer experiments with operational pools are given.
The Timing of First Marriage
Authors: Xu Xiaohe , Hudspeth Clark D. , Bartkowski John P.
Published: June 2005

Using survey data from a nationally representative sample, this article explores how marriage timing varies across major religious denominations. Survival analysis indicates that net of statistical controls, Catholics, moderate Protestants, conservative Protestants, and Mormons marry significantly earlier than their unaffiliated counterparts. This holds true for women and men. However, no statistical differences emerge between Jews, liberal Protestants, and the unaffiliated. As surmised, auxiliary statistical tests reveal additional religious subcultural variations: (a) Jews tend to marry later than Catholics, conservative Protestants, and Mormons; (b) Catholics also marry later than conservative Protestants and Mormons; (c) no statistical difference surfaces between Mormons and conservative Protestants; and (d) differences between Catholics and liberal Protestants as well as between Jews and liberal Protestants are statistically negligible. These findings systematically support the denominational subcultural paradigm in the case of marriage timing.
Restraining Orders in California
Authors: Sorenson Susan B. , Shen Haikang
Published: June 2005

The authors tabulated statewide administrative data for all types of restraining orders. On June 6, 2003, there were 227,941 active restraining orders against adults in California; most were for domestic violence. Rates of restraining orders (i.e., restrained persons) were highest for men, African Americans, and 25- to 34-year-olds. In 72.2% of the orders, a woman was to be protected and a man was to be restrained; in 19.3%, the restrained and protected persons were of the same sex. Although state law prohibits the purchase or possession of a firearm by persons against whom a restraining order is issued, 9.2% of the orders documented no firearm restrictions.
A Novel Catalyst for the Selective Hydrogenation of Furfural to Furfuryl Alcohol
Authors: Ying Hao Xiang- , Zhou Wei , Wang Jun-Wei , Zhang Yin-Qing , Liu Shuangxi
Published: June 2005

MCM-41 supported CuO catalyst with high metal loading level and dispersion degree was prepared via a novel preparative method. The catalyst shows remarkable high activity and selectivity in the hydrogenation of furfural to furfuryl alcohol.
Size-tuning and Optical Properties of High-quality CdSe Nanoparticles Synthesized from Cadmium Stearate
Authors: Teranishi Toshiharu , Nishida Masami , Kanehara Masayuki
Published: June 2005

High-quality CdSe nanoparticles were synthesized with a hot-injection method from cadmium stearate and selenium powder in the size range of 2.0 ± 0.2 to 8.6 ± 2.3 nm, corresponding to blue to red emission. The pod-shaped nanoparticles were formed at low reaction temperature, and exhibited sharp emission peak.
Heteroferrocene: The Synthesis of Bis[(3a,4,5,6,6a-η)-1,3,4,5,6-pentamethylcyclopenta[d]imidazo-2-thionoyl]iron(II)
Authors: Arduengo Anthony J , Bannenberg Thomas P , Tapu Daniela , Marshall William J
Published: June 2005

The synthesis of bis[(3a,4,5,6,6a-η)-1,3,4,5,6-pentamethylcyclopenta[d]imidazo-2-thionoyl]iron(II) is reported. Structural determination of the unusual hetero-substituted metallocene by X-ray crystallographic analysis is described. Preliminary electrochemical studies reveal that oxidation and reduction potentials for the subject ferrocene lie midway between those of ferrocene and decamethylferrocene.
A Reagentless Biosensor of Oxygen Based on the Direct Electrochemistry of Cytochrome c on the Surface of Multiwalled Carbon Nanotubes
Authors: Yin Zheng-Zhi , Zhao Guang-Chao , Wei Xian-Wen
Published: June 2005

Direct electrochemical response of cytochrome c (Cyt c), which was adsorbed onto the surface of multiwalled carbon nanotubes (MWNTs) through a simple cyclic potential scan technique, was observed. Cyt c adsorbed on MWNTs showed an enzyme-like activity to catalyze the reduction of oxygen (O2). Thus, a third generation O2 reagentless biosensor was constructed.
Highly trans-Selective Synthesis of β-Lactams by Tandem Phenoxide Anion-catalyzed Mannich-type Addition and Cyclization
Authors: Takahashi Eiki , Fujisawa Hidehiko , Yanai Toshiharu , Mukaiyama Teruaki
Published: June 2005

Highly trans-selective synthesis of β-lactams by tandem Lewis base-catalyzed Mannich-type addition and cyclization was established; that is, reaction of benzylideneanilines and trimethylsilyl enolates derived from S-ethyl thioates proceeded smoothly to afford the corresponding β-lactams in good to high yields with high trans-selectivity by using Lewis base catalyst such as lithium phenoxide or tetrabutyl ammonium phenoxide in DMF at −45 °C or THF at −78 °C, respectively.
An Analysis of a Strategic Decision in the Sport of Curling
Authors: Willoughby Keith A. , Kostuk Kent J.
Published: June 2005

We apply decision analysis to an important decision in the sport of curling. In particular, we examine the choice between taking a single point or blanking an end in the latter stages of a curling game. There are benefits and drawbacks associated with each alternative. Taking a single point provides the team with an additional point but transfers the last-shot advantage to the opposition. Blanking an end foregoes an additional point but retains the last-shot advantage. Based on the observation of world-class competitions, North American curlers will always attempt to blank an end, while their European counterparts have been known to opt for the single point. We develop a decision tree to conceptualize the choices. Then, we use data from over 900 national championship curling games to empirically determine the expected values of each alternative. Our results indicate that blanking the end is the better alternative.
A Multiple-Objective Decision Analysis of Stakeholder Values to Identify Watershed Improvement Needs
Authors: Merrick Jason R. W. , Parnell Gregory S. , Barnett Jamison , Garcia Margot
Published: June 2005

This paper describes the use of multiple-objective decision analysis to qualitatively and quantitatively assess the quality of an endangered watershed and guide future efforts to improve the quality of the watershed. The Upham Brook Watershed is an urban watershed that lies at the interface of declining inner-city Richmond, Virginia, and growth-oriented Henrico County. A section of stream within the watershed has been identified as so dangerously polluted that it threatens the health of the residents who live within the watershed boundaries. With funding provided by the National Science Foundation, the Upham Brook Watershed project committee was formed to address the quality of the Upham Brook Watershed; it consisted of experts from multiple disciplines: stream ecology, environmental policy, water policy, ground and surface water hydrology and quality, aquatic biology, political science, sociology, citizen participation, community interaction, psychology, and decision and risk analysis. Each member's values and goals were brought together using a watershed management framework to meet the overall objective of the committee: to maximize the quality of the Upham Brook Watershed. The resulting model was used to identify the largest value gaps and to identify future programs needed to improve the quality of the watershed.
How Do Prior Outcomes Affect Risk Attitude? Comparing Escalation of Commitment and the House-Money Effect
Authors: Weber Martin , Zuchel Heiko
Published: June 2005

When making sequential decisions, do prior gains induce more or less risk taking than prior losses? Prior studies have found evidence for a house-money effect, where risk taking increases following gains. These studies also found seemingly contradictory evidence for escalation of commitment, where risk taking increases following losses. We present an experimental study investigating this apparent contradiction. By manipulating the presentation format of a decision problem we can induce both types of behavior. When the problem is presented as a portfolio decision, risk taking is greater following losses than following gains, consistent with escalation of commitment. When the problem is presented as a two-stage betting game, risk taking is greater following gains than following losses, consistent with the house-money effect. Some of these results can be accounted for using the prospect-theory value function. Escalation of commitment in our experiment does not appear to be driven by a need to justify or rationalize the initial decision. These results are potentially relevant to modeling risk preference in multiperiod investment decisions.
Genetic Evaluation of a Great Lakes Lake Trout Hatchery Program
Authors: Page Kevin S. , Scribner Kim T. , Bast Dale , Holey Mark E. , Burnham‐Curtis Mary K.
Published: June 2005

Efforts over several decades to restore lake trout Salvelinus namaycush in U.S. waters of the upper Great Lakes have emphasized the stocking of juveniles from each of six hatchery broodstocks. Retention of genetic diversity across all offspring life history stages throughout the hatchery system has been an important component of the restoration hatchery and stocking program. Different stages of the lake trout hatchery program were examined to determine how effective hatchery practices have been in minimizing the loss of genetic diversity in broodstock adults and in progeny stocked. Microsatellite loci were used to estimate allele frequencies, measures of genetic diversity, and relatedness for wild source populations, hatchery broodstocks, and juveniles. We also estimated the effective number of breeders for each broodstock. Hatchery records were used to track destinations of fertilized eggs from all spawning dates to determine whether adult contributions to stocking programs were proportional to reproductive effort. Overall, management goals of maintaining genetic diversity were met across all stages of the hatchery program; however, we identified key areas where changes in mating regimes and in the distribution of fertilized gametes and juveniles could be improved. Estimates of effective breeding population size (Nb) were 9–41% of the total number of adults spawned. Low estimates of Nb were primarily attributed to spawning practices, including the pooling of gametes from multiple males and females and the reuse of males. Nonrandom selection and distribution of fertilized eggs before stocking accentuated declines in effective breeding population size and increased levels of relatedness of juveniles distributed to different rearing facilities and stocking locales. Adoption of guidelines that decrease adult reproductive variance and promote more equitable reproductive contributions of broodstock adults to juveniles would further enhance management goals of maintaining genetic diversity and minimize probabilities of consanguineous matings among stocked individuals when sexually mature.
Genetic Analyses of Juvenile Steelhead, Coastal Cutthroat Trout, and Their Hybrids Differ Substantially from Field Identifications
Authors: Baumsteiger Jason , Hankin David , Loudenslager Eric J.
Published: June 2005

Because of their similar appearance and frequent hybridization, juvenile steelhead Oncorhynchus mykiss and coastal cutthroat trout O. clarkii clarkii are difficult to distinguish visually. Nevertheless, field biologists often use visual methods to classify juvenile individuals. This study investigated hybridization between these species and determined the accuracy of field identification where hybridization occurred. Using a five‐point classification system, two evaluators identified 500 fish collected from three watersheds in Humboldt County, California. Individuals were then genotyped at seven single‐copy nuclear DNA genes and one mitochondrial gene, all assumed to be diagnostic for each species. Single‐locus Hardy–Weinberg equilibrium, pairwise genotypic disequilibrium, and cytonuclear disequilibrium calculations revealed that subpopulations of these species were mating assortatively. Presumptive F1 hybrid individuals were rare, whereas introgressed individuals were more common. These presumptive later‐generation backcross hybrids were produced with both parental species but were more frequently produced with coastal cutthroat trout. Interspecific matings appeared to be bidirectional. Conditional classification probabilities between evaluator identifications and genotypes showed that both evaluators had moderate to substantial success identifying individuals less than 85 mm total length, whereas individuals 85 mm and larger were identified less successfully. Evaluators successfully identified coastal cutthroat trout but had moderate difficulty identifying steelhead (sometimes misidentified as hybrids) and always misidentified hybrids as coastal cutthroat trout. Although visual identifications are not without error, approximately unbiased estimates of the percentage of hybrids may be generated from a combination of visual assignments and supplementary genetic analyses.
Identification and Characterization of Migratory and Nonmigratory Bull Trout Populations in the St. Mary River Drainage, Montana
Authors: Mogen Jim T. , Kaeding Lynn R.
Published: June 2005

Populations of migratory and nonmigratory bull trout Salvelinus confluentus were identified in the St. Mary River drainage, Montana. Migratory fish were most conspicuous because they were caught in traps operated near creek mouths or moved between creeks. Capture of postspawning bull trout in traps during four consecutive years suggested that most migratory fish had spawned by late September. Migratory bull trout reached maturity mainly as age‐5 fish that were typically 300 mm or larger in total length. Estimates based on the recapture of tagged fish in traps indicated that populations of migratory adult bull trout were significantly larger than the mean values from annual catches of trapped fish. Juvenile migratory bull trout departed natal creeks mainly as age‐2 or age‐3 fish. The scarcity of age‐4 bull trout in trap samples indicated that most migratory age‐4 fish were immature and inhabited either the downstream lakes or main‐stem river. Conversely, the abundance of age‐4 bull trout in electrofishing samples was primary evidence of nonmigratory populations in creeks. The occurrence of age‐0 bull trout in electrofishing samples indicated recent spawning and reproduction in five creeks, and annual reproduction was indicated by multiple age‐classes of young bull trout. Bull trout had growth rates similar to those of bull trout elsewhere, including marked growth of age‐4 fish that ostensibly resulted from their transition to a largely piscivorous diet. Migratory bull trout in the St. Mary River drainage are more common than previously believed and may be more common than in many other regions of the species' natural range.
Downstream Passage of Steelhead Kelts through Hydroelectric Dams on the Lower Snake and Columbia Rivers
Authors: Wertheimer Robert H. , Evans Allen F.
Published: June 2005

After spawning, iteroparous steelhead Oncorhynchus mykiss from the Columbia River basin must navigate several hydroelectric dams on their way to the Pacific Ocean. We used radiotelemetry to investigate migration rates, downstream passage routes, and success of adult steelhead kelts migrating past lower Snake River and Columbia River dams during the springs of 2001 and 2002. Seaward‐migrating kelts were collected, radio‐tagged, and volitionally released from the juvenile bypass facilities at Lower Granite Dam (LGR) on the Snake River and at McNary Dam (McN) and John Day Dam (JDD) on the Columbia River. Migration success rates from LGR to the study area exit (8 km east of Portland, Oregon) were poorer during the low‐flow nonspill conditions of 2001 (4.1%) than in the more typical flow year of 2002 (15.6%). Kelts tagged and released at Columbia River dams had substantially higher migration success than those released on the Snake River; 59.6% and 62.3% of the kelts released at McN and 63.6% and 80.0% of those released at JDD were contacted at the study area exit during 2001 and 2002, respectively. Kelt dam passage was predominately via spillways and surface flow routes, and during periods of spill 90.0% or more kelts typically passed via nonturbine routes. Only 47.2% of kelts were guided out of turbine intakes by screen systems during nonspill periods. Turbine passage, the primary alternative route during nonspill periods, may be a substantial source of kelt mortality. The poor migration success rate of Snake River kelts in both 2001 and 2002 suggests that additional management (i.e., kelt reconditioning, transportation, or both) may be warranted to boost iteroparity rates in this population.
Sense of Coherence as a Determinant of Toothbrushing Frequency and Level of Oral Hygiene
Authors: Savolainen Jarno J. , Suominen‐Taipale Anna‐Liisa , Uutela Antti K. , Martelin Tuija P. , Niskanen Mirka C. , Knuuttila Matti L.E.
Published: June 2005

Background: Antonovsky's salutogenic theory seeks to find general health‐promoting factors in individuals as distinct from characteristics that function as risks for specific diseases. A central construct of the theory is sense of coherence (SOC). Individuals with a strong SOC have the ability to define events as less stressful (because of comprehensibility); to mobilize resources to deal with encountered stressors (manageability); and to possess the motivation, desire, and commitment to cope (meaningfulness). Our aim is to investigate whether SOC, self‐reported toothbrushing frequency, and objectively assessed levels of oral hygiene are related.

Methods: The sample of the present study consisted of 4,131 30‐ to 64‐year‐old dentate Finns belonging to a large nationally representative sample. The questionnaire and home interview included information about socioeconomic and demographic factors, behavioral variables, such as oral health behaviors (toothbrushing frequency), and a 12‐item SOC scale, used here as a unidimensional measure categorized into quintiles. The level of oral hygiene was measured during clinical oral examination. Chi‐square test, ordinal, and ordinary logistic regression analyses were used.

Results: Subjects belonging to the strongest SOC quintile were found to be significantly more often two, or more, times a day brushers compared to those with less strong SOC. After controlling for toothbrushing frequency, sociodemographic and socioeconomic factors, smoking habits, and number of teeth, both strong and moderate levels of SOCs were also found to be related to a good level of oral hygiene compared with moderate and poor levels of oral hygiene. Furthermore, subjects within the weakest SOC quintile were found to have significantly more often than others poor levels of oral hygiene.

Conclusions: Our results suggest that a weak sense of coherence increases both the probability of having a poor level of oral hygiene and a frequency of toothbrushing of less than once a day. This and the theory concerning the development of SOC suggest that sense of coherence may be taken as a determinant of both the frequency and the quality of toothbrushing. J Periodontol 2005;76:1006‐1012.
Immediate Functional Loading of Edentulous Maxilla: A 5‐Year Retrospective Study of 388 Titanium Implants
Authors: Degidi Marco , Piattelli Adriano , Felice Pietro , Carinci Francesco
Published: June 2005

Background: Immediate functional loading is a new surgical‐prosthetic technique that can be used extensively in implant placement. Because of a lack of experimental reports regarding edentulous maxilla, we decided to evaluate the survival rate of immediately loaded dental implants in this area.

Methods: Forty‐three patients (44.4% male) with a median age of 55 years receiving 388 implants (mean 9.0 per case) were enrolled in this study. Cross‐arch acrylic provisional restorations were performed in the same stage. Data were analyzed by Kaplan‐Meier product limit estimation. Stratification of implants survival was performed for the available variables of interest, and comparisons were analyzed by a log rank test. Cox algorithm was used for multivariable analysis.

Results: At 5‐year follow‐up, the crude survival rate (overall survival not stratified according to any available variable) was 98%. All failures occurred within 6 months from loading. We found differences in survival relating to: 1) implant diameter (99.37% for diameter ≤5.25 mm and 93.75% for diameter >5.25 mm); 2) number of implants (99.29% for ≤10 implants and 96.30% for >10); and 3) gender (97.08% and 99.54% for males and females, respectively). Cox regression analysis showed that diameter of implants adjusted for patient age and gender was associated to an average risk of failure (hazard rate) of 3.13 (P value = 0.042, 95% confidence interval 1.04 to 9.43) per mm (from 3 to 6.5).

Conclusions: Immediate functional loading is a reliable surgical‐prosthetic procedure in edentulous maxillae. Implants with wider diameter are associated with a higher risk of failure. J Periodontol 2005;76:1016‐1024.
A Combined Therapeutic Approach to Manage Oral Halitosis: A 3‐Month Prospective Case Series
Authors: Roldán Silvia , Herrera David , O'Connor Ana , González Itziar , Sanz Mariano
Published: June 2005

Background: Clinical research assessing different therapeutic protocols aimed at treating oral halitosis is scarce. The aim of this study was to evaluate the effects of a combined mechanical and pharmacological approach to treat oral halitosis on clinical and microbiological outcomes on patients followed for 3 months.

Methods: Nineteen subjects with oral malodor participated. At baseline, all subjects completed a questionnaire and carried out an examination including full‐mouth organoleptic and volatile sulfur compound (VSC) levels and the Winkel tongue coating index. Standard periodontal outcome variables were assessed at six teeth. Standardized microbiological samples of subgingival plaque, unstimulated saliva, and tongue coating were obtained for culture analysis. The treatment protocol included supragingival prophylaxis; instructions in oral hygiene (toothbrushing, interproximal cleaning, and tongue scraping); and gargling with a mouthrinse containing chlorhexidine, cetylpiridinium chloride, and zinc lactate. The same outcome variables were registered 1 and 3 months after baseline.

Results: Statistically significant reductions in organoleptic scores ( P<0.001), VSC levels ( P<0.05), and tongue coating index (P<0.05) were observed after 1 and 3 months. Mean probing depth and plaque levels also demonstrated significant reductions after 3 months ( P<0.05). Total anaerobic counts were significantly reduced at all three locations after 1 month ( P<0.05), and in samples from tongue coating and subgingival plaque at 3 months ( P<0.05). Aerobic counts were significantly reduced in saliva at 1 month (P<0.05), and the anaerobic/aerobic ratio significantly increased in the tongue samples. Among the selected pathogens evaluated, Porphyromonas gingivaliswas the most affected of the three microflora evaluated.

Conclusions: The evaluated therapeutic approach demonstrated its efficacy in the management of oral halitosis, demonstrating statistically significant improvements in both organoleptic and VSC values at 1 and 3 months. The proposed clinical protocol significantly affected the microbial composition in tongue coating, saliva, and subgingival microflora. J Periodontol 2005; 76:1025‐1033.
Evaluation of the Safety and Efficacy of Periodontal Applications of a Living Tissue‐Engineered Human Fibroblast‐Derived Dermal Substitute. I. Comparison to the Gingival Autograft: A Randomized Controlled Pilot Study
Authors: McGuire Michael K. , Nunn Martha E.
Published: June 2005

Background: Periodontists have found the gingival autograft to be an effective and predictable technique to increase the amount of attached gingiva around teeth, but this technique requires the surgeon to harvest donor tissue from a remote surgical site. The present study seeks to evaluate the safety and effectiveness of a tissue‐engineered skin equivalent, a living human fibroblast‐derived dermal substitute (HF‐DDS), compared to a gingival autograft (GA) consisting of donor tissue harvested from the patient's palate in a procedure designed to increase the amount of keratinized tissue around teeth that do not require root coverage.

Methods: Twenty‐five patients with insufficient attached gingiva associated with at least two teeth in contralateral quadrants of the same jaw were treated. One tooth in each patient was randomized to receive either a GA (control) or a HF‐DDS graft (test). Clinical parameters measured at baseline and 3, 5, 7, 9, and 12 months included recession, clinical attachment level, keratinized tissue height, and plaque index. Probing depth was measured at 7, 9, and 12 months. Inflammation of each site was scored and texture and color of the grafted tissue were compared to the surrounding tissue. Resistance to muscle pull was evaluated and a questionnaire was used to determine patient preference. Surgical position of the graft and alveolar bone level were recorded at the surgical visit and patients were evaluated weekly for the first 4 weeks at which time recession and level of oral hygiene were measured. Biopsies and persistence studies were performed on a subset of the patients.

Results: Results for both test and control groups were similar for all measured clinical parameters with the exception of amount of keratinized tissue and percent shrinkage of keratinized tissue. The control group exhibited an average of 1.0 to 1.2 mm more keratinized tissue over time than the test group (P <0.001) and the control group had about half as much shrinkage as the test group over time (P <0.001). Test sites demonstrated significantly better color match over time compared to control sites. Similarly, tissue texture for test sites was significantly better than control sites over time.

Conclusions: Based on the results of this investigation, the tissue engineered HF‐DDS graft was safe and capable of generating keratinized tissue without the morbidity and potential clinical difficulties associated with donor site surgery. The GA generated more keratinized tissue and shrank less than the HF‐DDS graft, but the test graft generated tissue that appeared more natural. J Periodontol 2005;76:867‐880.
Platelet‐Rich Plasma Combined With a Porous Hydroxyapatite Graft for the Treatment of Intrabony Periodontal Defects in Humans: A Comparative Controlled Clinical Study
Authors: Okuda Kazuhiro , Tai Hideaki , Tanabe Kiyoshi , Suzuki Hironobu , Sato Tadashi , Kawase Tomoyuki , Saito Yoshinori , Wolff Larry F. , Yoshiex Hiromasa
Published: June 2005

Background: The aim of the present controlled clinical study was to compare platelet‐rich plasma (PRP) combined with a biodegradable ceramic, porous hydroxyapatite (HA) with a mixture of HA and saline in the treatment of human intrabony defects.

Methods: Seventy interproximal intrabony osseous defects in 70 healthy, non‐smoking subjects diagnosed with chronic periodontitis were included in this study. Thirty‐five subjects each were randomly assigned to either the test group (PRP and HA) or control group (HA with saline). Clinical and radiographic measurements were determined at baseline and the 12‐month evaluation.

Results: When compared to baseline, the 12‐month results indicated that, while both treatment modalities resulted in significant changes in all clinical parameters (gingival index, bleeding on probing, probing depth, clinical attachment level, and intrabony defect fill; P <0.001), the test group exhibited statistically significant changes compared to the control sites in probing depth reduction: 4.7 ± 1.6 mm versus 3.7 ± 2.0 mm (P <0.05); clinical attachment gain: 3.4 ± 1.7 mm versus 2.0 ± 1.2 mm (P <0.001); and vertical relative attachment gain: 70.3% ± 23.4% versus 45.5% ± 29.4% (P <0.001).

Conclusion: Treatment with a combination of PRP and HA compared to HA with saline led to a significantly more favorable clinical improvement in intrabony periodontal defects. J Periodontol 2005;76:890‐898.