bluuebunny/crossref_metadata_2025 huggingface dataset:
Convenient Synthesis of the Main Tridehydropentapeptide Skeleton for a Macrocyclic Antibiotic, Sulfomycin I
Authors: Kayano Tetsuya , Yonezawa Yasuchika , Shin Chung-gi
Published: December 2003

A convenient synthesis of the main tridehydropentapeptide skeleton [Fragment B–C derivative] of a thiostrepton-type macrocyclic antibiotic, sulfomycin I, was first achieved.
Peptide Nucleic Acid for Rapid Gap-selective Hydrolysis of DNA by Ce(IV)/EDTA Complex
Authors: Yamamoto Yoji , Komiyama Makoto
Published: December 2003

When gap-structures are formed in substrate DNA by using peptide nucleic acid (PNA), these sites are rapidly and selectively hydrolyzed by Ce(IV)/EDTA complex. Scission efficiency at the gap-site is 6-fold higher than that obtained by use of the corresponding DNA additives. Site-selectivity is also higher. The DNA/PNA duplexes must take anti-parallel direction here.
Return on Marketing: Using Customer Equity to Focus Marketing Strategy
Authors: Rust Roland T. , Lemon Katherine N. , Zeithaml Valarie A.
Published: December 2003

The authors present a unified strategic framework that enables competing marketing strategy options to be traded off on the basis of projected financial return, which is operationalized as the change in a firm's customer equity relative to the incremental expenditure necessary to produce the change. The change in the firm's customer equity is the change in its current and future customers’ lifetime values, summed across all customers in the industry. Each customer's lifetime value results from the frequency of category purchases, average quantity of purchase, and brand-switching patterns combined with the firm's contribution margin. The brand-switching matrix can be estimated from either longitudinal panel data or cross-sectional survey data, using a logit choice model. Firms can analyze drivers that have the greatest impact, compare the drivers’ performance with that of competitors’ drivers, and project return on investment from improvements in the drivers. To demonstrate how the approach can be implemented in a specific corporate setting and to show the methods used to test and validate the model, the authors illustrate a detailed application of the approach by using data from the airline industry. Their framework enables what-if evaluation of marketing return on investment, which can include such criteria as return on quality, return on advertising, return on loyalty programs, and even return on corporate citizenship, given a particular shift in customer perceptions. This enables the firm to focus marketing efforts on strategic initiatives that generate the greatest return.
Internal Benefits of Service-Worker Customer Orientation: Job Satisfaction, Commitment, and Organizational Citizenship Behaviors
Authors: Donavan D. Todd , Brown Tom J. , Mowen John C.
Published: December 2003

Implementation of the marketing concept in service firms is accomplished through individual service employees and their interactions with customers. Although prior research has established a link between service-worker customer orientation and performance outcomes, little research has addressed other potentially important outcomes of customer orientation. Drawing from the literature on person–situation interaction and fit theory, the authors develop and test a model that explains how service-worker customer orientation affects several important job responses, including perceived job fit, job satisfaction, commitment to the firm, and organizational citizenship behaviors. Across three field studies in two distinct services industries, the results indicate that the positive influence of customer orientation on certain job responses is stronger for service workers who spend more time in direct contact with customers than for workers who spend less time with customers. The authors discuss the implications of the results for services marketing managers and researchers.
An Empirical Analysis of the Determinants of Retail Margins: The Role of Store-Brand Share
Authors: Ailawadi Kusum L. , Harlam Bari
Published: December 2003

The authors develop and test a model of the key determinants of margins that retailers earn on national brands and store brands. They particularly focus on the impact of store-brand share on percentage margin, dollar margin per unit, and total dollar margin of the retailer. The authors find not only that percentage retail margins on store brands are higher than on national brands but also that high store-brand share enables retailers to earn higher percentage margins on national brands. However, the dollar margin per unit may be smaller for store brands because of their lower retail price. Furthermore, heavy store-brand users contribute much less to the total dollar profit of the retailer than do light store-brand users. The authors conclude that it is important for retailers to retain a balance between store brands and national brands to attract and retain the most profitable customers.
Invited Commentaries on “Evolving to a New Dominant Logic for Marketing”
Authors: Bolton Ruth N.
Published: December 2003

In the preceding article, Vargo and Lusch (V&L; 2004) observe that an evolution is underway toward a new dominant logic for marketing. The new dominant logic has important implications for marketing theory, practice, and pedagogy, as well as for general management and public policy. Thus, their observations are likely to resonate with a broad cross-section of the business community. With the goal of stimulating discussion and debate, I invited some distinguished scholars to write brief commentaries on different aspects of V&L's article. I was delighted to receive a thoughtful and diverse set of comments. The ideas expressed in the article and the commentaries will undoubtedly provoke a variety of reactions from readers of Journal of Marketing. I hope you will enjoy reading, and thinking, about these scholars’ views on the fundamental premises of marketing as much as I did.
First in, First out? The Effects of Network Externalities on Pioneer Survival
Authors: Srinivasan Raji , Lilien Gary L. , Rangaswamy Arvind
Published: December 2003

Network externalities are playing an increasingly important role in the economy, and they have significant implications for firms’ marketing strategies. The authors study the effects of network externalities in conjunction with other product and firm characteristics on the survival of pioneers. They apply an accelerated failure time model to data on 45 office products and consumer durables. The authors find evidence that network externalities have a negative main effect on the survival duration of pioneers. However, for more radical products and for technologically intense products, increases in network externalities are associated with increased survival duration. The larger the pioneer, the more network externalities increase its survival duration, whereas incumbent pioneers experience a decrease in survival duration compared with nonincumbents. The findings of this article contribute to theory in marketing strategy and have important implications for firms that are developing market entry strategies for products with network externalities.
Relationship Governance in a Supply Chain Network
Authors: Wathne Kenneth H. , Heide Jan B.
Published: December 2003

The authors examine how a firm's strategy in a (downstream) customer relationship is contingent on how a related relationship outside of the focal dyad is organized. Drawing on emerging perspectives on interfirm governance and networks, the authors propose that the ability to show flexibility toward a (downstream) customer under uncertain market conditions depends on the governance mechanisms that have been deployed in an (upstream) supplier relationship. The governance mechanisms take the form of (1) supplier qualification programs and (2) incentive structures based on hostages. The authors develop a set of contingency predictions and test them empirically in the context of vertical supply chain networks in the apparel industry. The tests show good support for the hypotheses. The authors discuss the implications of the findings for marketing theory and practice.
The production of route directions: investigating conditions that favour conciseness in spatial discourse
Authors: Daniel Marie‐Paule , Denis Michel
Published: December 2003

The study reported here investigated the effects of conditions expected to favour conciseness in the production of route directions. In Experiment 1, two groups of undergraduates were invited to give written descriptions of the route connecting two well‐known places on their university campus. The control group received standard instructions, and the other group was instructed to produce route directions that were as concise as possible, while remaining sufficiently informative to guide a pedestrian to the goal. Not surprisingly, instructions to be concise resulted in an overall shortening of descriptions, but this occurred in a selective manner. In particular, actions and action‐landmark combinations were the least affected, whereas the number of landmarks mentioned without being associated with actions, as well as of details describing landmarks, was considerably reduced. Furthermore, landmarks situated at points on the route involving a decision about changing direction underwent less reduction than other landmarks. In Experiment 2, conditions were created where conciseness was brought into play without any explicit instructions to be concise. Undergraduates were asked to work in groups of three, and each group was assigned the task of producing a single description. The results showed that the descriptions produced by a group were shorter than those produced by individuals. This was interpreted as reflecting that in the absence of any conciseness instructions, the feedback developed within groups during the production of route directions led to effective selection of the information content. Interestingly, the items relating actions and landmarks were almost fully preserved in the group descriptions. In Experiment 3, conciseness was shown to be further increased by combining instructions for conciseness and group production. Altogether, the three experiments revealed the primary role of propositions linking action prescriptions and landmarks at points on the route where key actions have to be taken. Copyright © 2003 John Wiley & Sons, Ltd.
Cancer mortality among French Atomic Energy Commission workers
Authors: Telle‐Lamberton M. , Bergot D. , Gagneau M. , Samson E. , Giraud J.M. , Néron M.O. , Hubert P.
Published: December 2003

Background

All causes and cancer mortality of 58,320 workers employed at the Commissariat à l'Energie Atomique (CEA) between 1946 and 1994 were compared with that of the general population in a retrospective cohort study.

Methods

Standardized Mortality Ratios (SMR) were computed with reference to the French national population.

Results

Between 1968 and 1994, 4,809 deaths occurred. A healthy worker effect is observed for men (SMR = 0.57, CI90% = [0.56;0.59]) and for women (SMR = 0.72, CI90% = [0.67;0.77]). Nine sites of cancer death were found to be in statistically significant deficit among men, none among women. An excess of pleural cancers is observed among men (SMR = 1.79, CI90% = [1.27;2.45]) and of malignant melanoma (SMR = 1.50, CI90% = [1.04;2.11]). An excess of breast cancer is observed among women on the borderline of significance (SMR = 1.14, CI90% = [0.94;1.37]).

Conclusions

Excesses observed will have to be related to occupational exposures in the on‐going cohort study on French nuclear workers which includes a retrospective exposures assessment. Am. J. Ind. Med. 45:34–44, 2004. © 2003 Wiley‐Liss, Inc.
Occupational injury mortality surveillance in the United States: An examination of census counts from two different surveillance systems, 1992–1997
Authors: Layne Larry A.
Published: December 2003

Background

The surveillance of occupational injury mortality in the United States has evolved over the last century. Currently there are two different data sources used for the study of occupational injury mortality. Each system varies in methodology, leading to different census counts. We provide an overview and analysis of similarities and differences in these two systems.

Methods

The National Traumatic Occupational Fatalities (NTOF) surveillance system and the Census of Fatal Occupational Injuries (CFOI) were examined for civilian deaths at work in the United States from 1992 to 1997.

Results

There were 31,643 occupational injury mortality cases according to NTOF and 37,023 from CFOI for civilian workers 16‐years and older in the United States for the 6‐year period of analysis. The annual average occupational injury mortality rates were 4.5 per 100,000 full time equivalent workers from NTOF and 5.2 from CFOI. The higher capture rate by CFOI was consistent across each of the 6 years. Similar patterns for demographics, industry, and occupation, and type of incident were seen for both systems.

Conclusions

While NTOF provides more years of data dating back to 1980, CFOI (established in 1992) provides a more comprehensive capture of occupational injury mortality and provides greater detail of the mortality incidents. The overall injury mortality patterns, however, appear to be similar between the systems. Am. J. Ind. Med. 45:1–13, 2004. © 2003 Wiley‐Liss, Inc.
Acute occupational pesticide‐related illness in the US, 1998–1999: Surveillance findings from the SENSOR‐pesticides program
Authors: Calvert Geoffrey M. , Plate David K. , Das Rupali , Rosales Rachel , Shafey Omar , Thomsen Catherine , Male Dorilee , Beckman John , Arvizu Ernest , Lackovic Michelle
Published: December 2003

Background

Concern about the adverse public health and environmental effects of pesticide use is persistent. Recognizing the importance of surveillance for acute occupational pesticide‐related illness, we report on surveillance for this condition across multiple states.

Methods

Survey data collected between 1998 and 1999 were obtained from the seven states that conduct acute occupational pesticide‐related illness surveillance as part of the Sentinel Event Notification System for Occupational Risks (SENSOR) program. Data were collected by these state programs in a standardized manner and analyzed. Acute occupational pesticide‐related illness incidence rates for those employed in agriculture and those employed in non‐agricultural industries were also calculated.

Results

Between 1998 and 1999, a total of 1,009 individuals with acute occupational pesticide‐related illness were identified by states participating in the SENSOR‐pesticides program. The mean age was 36 years, and incidence rates peaked among 20–24 year‐old workers. The overall incidence rate was 1.17 per 100,000 full time equivalents (FTEs). The incidence rate among those employed in agriculture was higher (18.2/100,000 FTEs) compared to those employed in non‐agricultural industries (0.53/100,000 FTEs). Most of the illnesses were of low severity (69.7%). Severity was moderate in 29.6% of the cases, and high in four cases (0.4%). Three fatalities were identified. Insecticides were responsible for 49% of all illnesses.

Conclusions

Surveillance is an important tool to assess acute pesticide‐related illness, and to identify associated risk factors. Our findings suggest that these illnesses continue to be an important occupational health problem, especially in agriculture. As such, greater efforts are needed to prevent acute occupational pesticide‐related illness. Am. J. Ind. Med. 45:14–23, 2004. Published 2003 Wiley‐Liss, Inc.
Malignant mesothelioma in Italy, 1997
Authors: Nesti Massimo , Marinaccio Alessandro , Chellini Elisabetta ,   Regional Operational Centers
Published: December 2003

Background

The Italian National Mesothelioma Register (ReNaM) was set up at the Istituto Superiore Prevenzione e Sicurezza Lavoro (ISPESL), in Rome, in accordance with Art. 36 of Italian Legislative Decree No. 277 [1991].

Methods

Five Italian regions, Piedmont, Liguria, Emilia‐Romagna, Tuscany, and Apulia, agreed to record mesothelioma cases according to guidelines established by ISPESL, to define exposure to asbestos and transmit the data systematically to ISPESL.

Results

Four hundred and twenty‐nine mesothelioma cases, diagnosed in 1997, are recorded. The standardized annual incidence rate for definite pleural mesothelioma is 1.51 per 100,000 inhabitants (2.26 for males and 0.79 for females). Exposure was defined for 198 mesotheliomas with a histological diagnosis: 125 (63%) refer to occupational exposure, 10 (5%) to environmental exposure, and 5 (2.5%) to household exposure.

Conclusions

Despite the ReNaM's work, many limitations still have to be overcome. Clear‐cut information on asbestos exposure is available for a limited number of cases; and differing regional procedures in collecting and evaluating mesotheloma cases exist. At this stage the identification and evaluation of a large number of cases of mesothelioma is a worthwhile result. This epidemiological surveillance, currently being extended to other regions, will enable us to better assess the impact and diffusion of this disease in future, and to monitor more closely the effects of ceasing asbestos use in 1992, and the efficacy of preventive measures since mid '70s. Am. J. Ind. Med. 45:55–62, 2004. © 2003 Wiley‐Liss, Inc.
Integration of workers' compensation and health insurance prescription drug programs: How does it work and do employees use it?
Authors: Saleh Shadi , Washington Stephanie , Stapleton David , Livermoore Gina
Published: December 2003

Background

In 1998, New York State designed and developed an integrated workers' compensation (WC)/health plan prescription drug program, ONECARD Rx, in response to cost inefficiencies within the then current system and in an attempt to improve the quality of care provided to WC claimants. This paper describes the benefit's design and development process and factors related to its use.

Methods

Users and non‐users of the program were surveyed through a mailed questionnaire with appropriate telephone follow‐up.

Results

Eight steps were followed in the development of the benefit. Results obtained from the assessment of ONECARD Rx suggest that factors affecting use mainly relate to the knowledge of both, employees and pharmacists, of the program. The two main differences detected between users and non‐users included the state agency the employee works for and the site of residence.

Conclusions

Innovative strategies that couple private and public agencies should aim at reducing the costs and eliminating inefficiencies while improving the quality of care, of which satisfaction is an important component. Am. J. Ind. Med. 45:103–112, 2004. © 2003 Wiley‐Liss, Inc.
Immunological and respiratory changes in tobacco workers
Authors: Zuskin Eugenija , Mustajbegovic Jadranka , Schachter E. Neil , Kanceljak Bozica , Macan Jelena , Kern Josipa , Buneta Lucija , Pucarin‐Cvetkovic Jasna
Published: December 2003

Background

Tobacco workers develop respiratory changes following occupational exposure to tobacco dust.

Methods

This study investigated 102 tobacco workers as well as a group of 30 matched control workers. Immunological testing, symptom questionnaire, and lung function measurements were performed in all workers.

Results

Increased total IgE was found in 12.7% of tobacco workers but in none of the controls (P < 0.05). Increased specific IgE (tobacco allergen) was recorded in 26.7% of tobacco workers with positive skin tests to tobacco extract but in none of the controls (P < 0.05). Regression analysis of ventilatory tests in female tobacco workers indicated a significant association of FEF75 to employment and smoking among workers with positive skin tests to tobacco. There were, however, no other associations between positive immunologic findings and lung function abnormalities and symptoms.

Conclusions

Our study found increased immunological reactions in the tobacco workers. However, with the possible exception of lung function at low lung volume in female workers, these reactions do not appear to contribute significantly to the symptoms and lung function abnormalities seen in these workers. Am. J. Ind. Med. 45:76–83, 2004. © 2003 Wiley‐Liss, Inc.
Mercury, cadmium, and arsenite enhance heat shock protein synthesis in chick embryos prior to embryotoxicity
Authors: Papaconstantinou Andriana D. , Brown Ken M. , Noren Bradley T. , McAlister Terence , Fisher Benjamin R. , Goering Peter L.
Published: December 2003

BACKGROUND: Cells respond to adverse environmental stimuli by enhancing the expression of specific genes, the products of which include a suite of proteins known as heat shock proteins (hsps), a response often attributed to cellular protection. METHODS:In this study, we characterized alterations in hsp expression in chick embryos (Hamburger‐Hamilton stage 17, 72 h) exposed in ovo to arsenite (As), mercury (Hg), and cadmium (Cd), known developmental toxicants. Embryos were incubated for 2 h following exposure to 3, 10, 30, or 100 nmol metal, or for 2, 4, 12, or 24 h following treatment with 10 nmol metal. RESULTS: An enhanced de novo synthesis of 24‐, 70‐, and 90‐kD, 70‐ and 90‐kD, and 70‐kD proteins was observed with As, Hg, and Cd treatments, respectively. These responses were transient; apparent rates of protein synthesis were maximal 2–4 h after exposure and returned to control rates by 24 h. Actinomycin D experiments demonstrated that arsenite‐induced expression of these proteins is transcriptionally regulated. Immunoblotting experiments identified the 24‐, 70‐, and 90‐kD proteins as the heat shock proteins hsp24, hsp70, and hsp90, respectively. Exposure duration‐related abnormalities were noted in the neural tube with all metals and in the ganglia and somites with Cd and As. Retina, allantois, and limb defects were specific to Cd‐treated embryos, and branchial arch defects were specific to As‐treated embryos. CONCLUSIONS: The data support metal‐induced developmental abnormalities, which are preceded by synthesis of stress proteins. Birth Defects Res B 68:456–464, 2003. Published 2003 Wiley‐Liss, Inc.
Prenatal window of susceptibility to perfluorooctane sulfonate‐induced neonatal mortality in the Sprague‐Dawley rat
Authors: Grasty Rayetta C. , Grey Brian E. , Lau Christopher S. , Rogers John M.
Published: December 2003

The critical period for increased neonatal mortality induced by perfluorooctane sulfonate (PFOS) exposure was evaluated in the rat. Timed‐pregnant Sprague‐Dawley rats were treated by oral gavage with 25 mg/kg/d PFOS/K+ on four consecutive days (gestation days (GD) 2–5, 6–9, 10–13, 14–17, or 17–20) or with 0, 25, or 50 mg/kg/d PFOS/K+ on GD 19–20. Controls received vehicle (10 ml/kg 0.5% Tween‐20) on these days. Maternal weight gain was reduced in treated animals during dosing, as were food and water consumption. Following a 4‐day treatment, litter size at birth was unaffected while pup weight was similarly reduced in the three earliest PFOS groups. All PFOS groups experienced decreases in survival while controls remained near 100%. Neonatal survival decreased in groups dosed later during gestation, approaching 100% with dosing on GD 17–20. Most deaths occurred before postnatal day (PND) 4, with the majority in the first 24 hours. Maternal serum PFOS levels on GD 21 were higher in groups exhibiting higher mortality. Following a 2‐day treatment, PFOS groups experienced significant pup mortality by PND 1. Neonatal mortality continued through PND 5, when survival was 98, 66, and 3% for the 0, 25, and 50 mg/kg groups, respectively. Pup weight was reduced in treated groups with surviving litters. Gross dissection and histological examination of lungs revealed differences in maturation between control and treated animals on PND 0. We conclude that exposure to PFOS late in gestation is sufficient to induce 100% pup mortality and that inhibition of lung maturation may be involved. Birth Defects Res B 68:465–471, 2003. Published 2003 Wiley‐Liss, Inc.
Regulatory issues concerning the safety, efficacy and quality of herbal remedies
Authors: Rousseaux Colin G. , Schachter Howard
Published: December 2003

Herbal remedies and alternative medicines are used throughout the world, and in the past herbs were often the original sources of most drugs. Today we are witnessing an increase in herbal remedy use throughout the Western world raising the question as to how safe are these preparations for the unborn fetus? Many women use herbal products during pregnancy. The dilemma facing most regulatory authorities is that the public considers these products as either traditional medicines or natural food supplements. The user sees no reason for regulation. Most countries have laws concerning foods, drugs, and cosmetics, the details of which seldom clearly define to what section of the law and regulations alternative remedies belong. In most countries alternative remedies are regulated as foods, provided that no medicinal claim is made on the label. The global regulatory sector, however, is changing rapidly. The Therapeutic Goods Administration (TGA) in Australia created a Complimentary Medicines Evaluation Committee in late 1997 to address this issue, and Canada has created a new Natural Health Products Directorate in the realigned Therapeutic Products and Foods Branch in 2000. In parallel, the European Agency for the Evaluation of Medicinal Products has drafted test procedures and acceptance criteria for herbal drug preparations and herbal medicinal products. In the US, the Food and Drug Administration classifies these natural products as dietary supplements. Manufacturers must label a dietary supplement thus: “this statement has not been evaluated by the FDA [, and] this product is not intended to diagnose, treat, cure or prevent any disease.” Whether these products are foods or drugs is undecided. To add complexity to this issue, most of the potential deleterious effects of natural products on the unborn may be related to hormonal effects (e.g., phytoestrogens) and nutriceutical drug interactions (e.g., St. John's Wort and antidepressants), rather than direct embryotoxicity per se. We suggest that ensuring quality of herbal products should receive immediate attention by regulatory authorities, before embarking on the more arduous tasks of safety and efficacy. Birth Defects Res B 68:505–510, 2003. © 2003 Wiley‐Liss, Inc.
Statistical correlation between protein secondary structure and messenger RNA stem‐loop structure
Authors: Jia Mengwen , Luo Liaofu , Liu Ciquan
Published: December 2003

A new integrated sequence‐structure database, called IADE (Integrated ASTRAL‐DSSP‐EMBL), incorporating matching mRNA sequence, amino acid sequence, and protein secondary structural data, is constructed. It includes 648 protein domains. Based on the IADE database, we studied the relation between RNA stem‐loop frequencies and protein secondary structure. It was found that the α‐helices and β‐strands on proteins tend to be preferably “coded” by mRNA stem region, while the coils on proteins tend to be preferably “coded” by mRNA loop region. These tendencies are more obvious if we observe the structural words (SWs). An SW is defined by a four‐amino‐acid‐fragment that shows the pronounced secondary structural (α‐helix or β‐strand) propensity. It is demonstrated that the deduced correlation between protein and mRNA structure can hardly be explained as the stochastic fluctuation effect. © 2003 Wiley Periodicals, Inc. Biopolymers 73: 16–26, 2004
Chitosan hollow fiber membranes
Authors: Modrzejewska Zofia , Eckstein Wojciech
Published: December 2003

Chitosan hollow fibers were produced by wet spinning, taking advantage of the unique rheological properties of highly viscous chitosan solutions in acetic acid. The mechanical and separation properties of hollow fibers were tested. The mechanical properties were determined by measuring tensile force, tensile stress, elongation, and initial elasticity module. The separation properties were specified by determining retention coefficients of particular blood components and determining cut‐off of the membrane by the analysis of dextran molecular weight distribution in the feed and permeate using a technique of gel chromatography (GPC)—Shimadzu gel chromatograph. © 2003 Wiley Periodicals, Inc. Biopolymers 73: 61–68, 2004
Gelation behaviors of schizophyllan‐sorbitol aqueous solutions
Authors: Fang Yapeng , Nishinari Katsuyoshi
Published: December 2003

On addition of D‐sorbitol, schizophyllan (SPG) aqueous solution forms a thermoreversible gel upon cooling. The gelation process is characterized by rheology, differential scanning calorimetry (DSC), and optical rotation measurement (ORD). It is found that the Winter‐Chambon criterion works well in determining the critical gelation point of the present system, although the criterion has been scarcely applicable to systems that show weak‐gel properties even before gelation. Moreover, ORD and DSC results indicate that a disordered to ordered conformational change accompanies the gelation process, which is attributed to the transition from SPG triple helix II to I. The gelation temperature of SPG‐sorbitol aqueous solution is almost independent of SPG concentration in the examined concentration range and is slightly decreased by lowering SPG molecular weight, while greatly influenced by sorbitol content. The gelation is considered to be induced by the transition from SPG triple helix II to I, which leads to a three‐dimensional network constituted by the extremely entangled and stiff SPG triple helices I. Furthermore, it is proved that neither junction zone nor aggregation of SPG triple helices is involved in the SPG‐sorbitol gels. The SPG‐sorbitol gel is structurally like a solution that is unable to flow within a timescale of usual observation. © 2003 Wiley Periodicals, Inc. Biopolymers 73: 44–60, 2004
The hairpin ribozyme
Authors: Ferré‐D'Amaré Adrian R.
Published: December 2003

The hairpin ribozyme is a naturally occurring RNA that catalyzes sequence‐specific cleavage and ligation of RNA. It has been the subject of extensive biochemical and structural studies, perhaps the most detailed for any catalytic RNA to date. Comparison of the structures of its constituent domains free and fully assembled demonstrates that the RNA undergoes extensive structural rearrangement. This rearrangement results in a distortion of the substrate RNA that primes it for cleavage. This ribozyme is known to achieve catalysis employing exclusively RNA functional groups. Metal ions or other catalytic cofactors are not used. Current experimental evidence points to a combination of at least four mechanistic strategies by this RNA: (1) precise substrate orientation, (2) preferential transition state binding, (3) electrostatic catalysis, and (4) general acid base catalysis. © 2003 Wiley Periodicals, Inc. Biopolymers 73: 71–78, 2004
Mechanistic studies on acyl‐transferase ribozymes and beyond
Authors: Hodgson David R. W. , Suga Hiroaki
Published: December 2003

In vitro selection has allowed the isolation of many new ribozymes that are able to catalyze an ever‐widening array of chemical transformations. Mechanistic studies on these selected ribozymes have provided valuable insight into the methods that RNA can invoke to overcome different catalytic tasks. We focus on the methods employed in these mechanistic studies using the acyl‐transferase family of selected ribozymes as well‐studied reference systems. Chemical and biochemical techniques have been used in tandem in order to draw conclusions on the various modes of catalysis employed by the different family members. In turn, this type of mechanistic information may provide a means for the redesign and optimization of existing ribozymes or the basis for new selection systems for more powerful RNA catalysts. © 2003 Wiley Periodicals, Inc. Biopolymers 73: 130–150, 2004
Catalytic roles for proton transfer and protonation in ribozymes
Authors: Bevilacqua Philip C. , Brown Trevor S. , Nakano Shu‐ichi , Yajima Rieko
Published: December 2003

Utilization of proton transfer in catalysis, which is well known in the mechanisms of protein enzymes, has been described only relatively recently for RNA enzymes. In this article, we present a current understanding of proton transfer by nucleic acids. Rate enhancement and specificity conferred by general acid–base catalysis are discussed. We also present possibilities for electrostatic catalysis from general acids and bases as well as cationic base pairs. The microenvironments of a large RNA provide the possibility of histidine‐like pKas for proton transfer, as well as lysine‐ and arginine‐like pKas for electrostatic catalysis. Discussion on proton transfer focuses on the hepatitis delta virus (HDV) and hairpin ribozymes, with select examples drawn from the protein literature. Discussion on electrostatic catalysis also draws on these two ribozymes, and a postulate for electrostatic catalysis by a cationic base pair in the mechanism of peptidyl transfer in the ribosome is presented. We also provide a perspective on possibilities for phosphoryl transfer mechanisms involving phosphorane intermediates and unusual tautomeric forms of the bases. Lastly, a distinction is made between ground state and “transition state” pKas. We favor a model in which changes in pH lead to changes in the distribution of reactive and nonreactive ionizations of the ribozyme molecules in the ground state, and therefore suggest that “pKa changes in the transition state” do not provide an acceptable explanation for observed pH‐rate profiles. © 2003 Wiley Periodicals, Inc. Biopolymers 73: 90–109, 2004
Subtypes of adolescent offenders: affective traits and antisocial behavior patterns
Authors: Vincent Gina M. , Vitacco Michael J. , Grisso Thomas , Corrado Raymond R.
Published: December 2003

Etiological models of life‐course persistent offending often emphasize behavioral explanations. Suggestions that persistent offenders have psychopathy ignore the distinct non‐behavioral features of the psychopathy disorder. Using a three‐factor model of the PCL‐YV and cluster analysis with 259 incarcerated adolescents, we identified four distinct juvenile subtypes on the basis of affective, interpersonal, and behavioral dimensions. Prospective and retrospective comparisons of antisocial behavior patterns found the cluster comprising all three psychopathy dimensions to be the most chronic and severe. Impulsive features alone were strongly associated with severe antisocial behaviors retrospectively, but not prospectively. Findings rebut the proposal that disruptive behavioral and impulsive symptoms can identify “fledgling psychopaths.” Assessments that disregard callous–unemotional traits will likely result in high false positive rates among serious adolescent offenders. Implications for developmental models of chronic offending are discussed in light of the need for further follow‐up into adulthood. Copyright © 2003 John Wiley & Sons, Ltd.
The validity of the Antisocial Process Screening Device as a self‐report measure of psychopathy in adolescent offenders
Authors: Lee Zina , Vincent Gina M. , Hart Stephen D. , Corrado Raymond R.
Published: December 2003

There is a growing interest in the assessment of adolescent psychopathy to enable early treatment and intervention. Recently, a self‐report measure has been developed to assess psychopathic traits in adolescents. The Antisocial Process Screening Device (APSD), a self‐report measure of psychopathic traits, and the Psychopathy Checklist: Youth Version (PCL:YV), a clinical rating scale, were administered to a sample of 100 incarcerated male adolescent offenders to assess the concurrent validity of the APSD. Results indicated that the APSD had limited concurrent validity with respect to the PCL:YV and that there appears to be a method effect in the measurement of psychopathy. Thus, it appears the APSD did not assess psychopathy in a manner parallel to that of the PCL:YV. Copyright © 2003 John Wiley & Sons, Ltd.
Tensile properties of fresh human calcaneal (achilles) tendons
Authors: Louis‐Ugbo John , Leeson Benjamin , Hutton William C.
Published: December 2003

The purpose of this study was to measure the tensile properties of fresh human calcaneal (Achilles) tendons. Twenty fresh cadaveric (age range = 57–93 years) bone‐Achilles tendon complexes were harvested within 24 hr postmortem. The calcaneus together with 15 cm of the Achilles tendon extending proximally from the insertion on the calcaneus was clamped and biomechanically tested. Each tendon was firmly fixed in clamps in an MTS Systems Corporation MTS testing machine and tension was applied at a displacement rate of 8 cm per minute until the tendon failed. The tensile force and tensile strain (as measured using an extensometer) were recorded and plotted using onboard software. The narrow age range of our donors prevented any meaningful correlation between age and tensile properties; however, the results showed that: 1) the average ultimate tensile strength (UTS) of the human Achilles tendon was 1189 N (range = 360–1,965), 2) there was a correlation between left and right legs for UTS, 3) there was a correlation between left and right legs in regard to cross sectional area, and 4) there was no correlation between UTS and cross‐sectional area. Clin. Anat. 17:30–35, 2004. © 2003 Wiley‐Liss, Inc.
Pes anserinus: Layered supportive structure on the medial side of the knee
Authors: Mochizuki Tomoyuki , Akita Keiichi , Muneta Takeshi , Sato Tatsuo
Published: December 2003

The pes anserinus is composed of a combination of tendinous insertions of the sartorius, gracilis and semitendinosus muscles. Precise knowledge of the structures on the medial side of the knee and the relationships between fascia and tendons is critical for diagnosis, surgery, and the development of improved operative procedures of the knee. To obtain precise data on the layered structures associated with the fascia cruris on the medial side of the knee and the fibrous bundles attached to them, we dissected nine legs of five adult cadavers. We observed a superficial longitudinal fibrous bundle on the superficial surface of the sartorius and a deep longitudinal fibrous bundle on the aponeurotic membrane covering the tendon of the gracilis muscle. The distal parts of the tendons of the gracilis and semitendinosus were found to have aponeurotic membranes, and these membranes were fused with the fascia cruris. These two longitudinal fibrous bundles and the aponeurotic membranes from the gracilis and semitendinosus tendons fused with the fascia cruris, and a small tendinous expansion from the semimembranosus muscle fused with the aponeurotic membrane from the semitendinosus tendon and tibial collateral ligament as well as the fascia covering the medial head of the gastrocnemius and fascia cruris. Based on the considerable tension from the sartorius, gracilis, semitendinosus, semimembranosus and gastrocnemius muscles, these bundles, membranes, and muscles may act as a complex tensor fasciae cruris muscle and play a significant role as stabilizers of the medial side of the knee joint in the upright posture. Clin. Anat. 17:50–54, 2004. © 2003 Wiley‐Liss, Inc.
Internal anal sphincter: An anatomic study
Authors: Uz A. , Elhan A. , Ersoy M. , Tekdemir I.
Published: December 2003

The anatomy of the internal anal sphincter and surrounding structures was investigated in 24 cadavers using a surgical microscope (6–25× magnification). An understanding of the anatomy of the internal anal sphincter is helpful in avoiding complications during surgical procedures in the anorectal region. The external anal sphincter was composed of three ellipsoid rings of skeletal muscle (subcutaneous, superficial, and deep) that encircle the anal canal; in contrast, we found that the internal anal sphincter was composed of flat rings of smooth muscle bundles stacked one on top of the other, like the slats of a Venetian blind. In each anal canal, the average number of ring‐like slats observed was 26.33 ± 2.93 (range = 20–30) and each was covered by its own fascia. The smooth muscle fibers and fascia coalesced at three equidistant points around the anal canal to form three columns that extended distally into the lumen and differed in form from the other anal columns. When viewed from an anterior position, the columns were located anteriorly at the observer's right (5 o'clock position), posteriorly at the right (1 o'clock position), and laterally at the left (9 o'clock position). This heretofore unreported anatomy of the internal anal sphincter may play an important role in closing off the lumen of the anal canal and maintaining bowel continence. Clin. Anat. 17:17–20, 2004. © 2003 Wiley‐Liss, Inc.
Penetration of muscles by branches of the mandibular nerve: A possible cause of neuropathy
Authors: Shimokawa Takashi , Akita Keiichi , Sato Tatsuo , Ru Fei , Yi Shuang‐Qin , Tanaka Shigenori
Published: December 2003

We carried out detailed dissections of the branches of the mandibular nerve and muscles innervated by these branches to investigate their positional relationships. We made the following observations: 1) small branch of the auriculotemporal nerve penetrated the lateral pterygoid muscle; 2) the entire lingual nerve penetrated the medial pterygoid muscle; and 3) branch of the mylohyoid nerve penetrated the mylohyoid muscle and communicated with the submandibular ganglion. No detailed descriptions of these nerve branches have been reported previously. The existence of these nerve branches that penetrate muscles might result in the neuralgic pain in the trigeminal region when such pain is of unknown origin. Clin. Anat. 17:2–5, 2004. © 2003 Wiley‐Liss, Inc.
Genotype and allele frequencies of polymorphic cytochromes P450 CYP1A2 and CYP2E1 in Mexicans
Authors: Mendoza‐Cantú Ania , Castorena‐Torres Fabiola , Bermudez Mario , Martínez‐Hernández Roberto , Ortega Arturo , Salinas Juan E. , Albores Arnulfo
Published: December 2003

CYP1A2 and CYP2E1 are two of the main cytochrome P450 isoforms involved in the metabolism of commonly used drugs and xenobiotic compounds considered to be responsible for or possible participants in the development of several human diseases. Individual susceptibility to developing these pathologies relies, among other factors, on genetic polymorphism which depends on ethnic differences, as the frequency of mutant genotypes varies in different human populations. Thus the aim of this study was to investigate the frequency of CYP1A2 5′‐flanking region and CYP2E1 Rsa I/Pst I polymorphisms in Mexicans by PCR‐RFLP methods. The DNA of 159 subjects was analysed and mutant allele frequencies of 30% for CYP2E1 Rsa I/Pst I sites and 43% for CYP1A2 5′‐flanking region were found. These frequencies are higher than those previously reported for other human populations. Copyright © 2003 John Wiley & Sons, Ltd.
Effects of additional vitamin E and selenium supply on antioxidative defence mechanisms in the kidney of rats treated with high doses of glucocorticoid
Authors: Beytut Ebru , Erişir Mine , Aksakal Mesut
Published: December 2003

The aim of this work was to determine the effects of dietary vitamin E and selenium (Se) on lipid peroxidation as thiobarbituric acid reactive substances (TBARS) and on the antioxidative defence mechanisms in the kidney of rats treated with high‐doses of prednisolone. Two hundred and fifty adult male Wistar rats were randomly divided into five groups. The rats were fed a normal diet, but groups 3, 4, and 5 received a daily supplement in their drinking water of 20 mg vitamin E, 0.3 mg Se, and a combination of vitamin E and Se, respectively, for 30 days. For 3 days subsequently, the control group (group 1) was treated with a placebo, and the remaining four groups were injected intramuscularly with 100 mg kg−1 body weight (bw) prednisolone. After the last administration of prednisolone, 10 rats from each group were killed at 4, 8, 12, 24, and 48 h and the activities of glutathione peroxidase (GSH‐Px) and catalase (CAT) enzymes, and the levels of glutathione (GSH) and TBARS in their kidneys were measured. GSH‐Px and CAT enzyme activities and GSH levels in the prednisolone treatment group (group 2) began to decrease gradually at 4 h, falling respectively to 48 and 65% of the control levels by 24 h, and recovering to the control levels at 48 h. In contrast, prednisolone administration caused an increase in TBARS in the kidneys, reaching up to twice the levels of the control group at 24 h. However, supplementation with vitamin E and Se had a preventive effect on the elevation of kidney TBARS and improved the diminished activities of the antioxidative enzymes and the levels of GSH. Therefore, the present study demonstrates the effectiveness of vitamin E and Se in reducing kidney damage in glucocorticoid‐treated rats and suggests that reductions in increased TBARS due to prednisolone may be an important factor in the action of vitamin E and Se. Copyright © 2003 John Wiley & Sons, Ltd.
Dephosphorylation of inner arm 1 is associated with ciliary reversals in Tetrahymena thermophila
Authors: Deckman Cassandra M. , Pennock David G.
Published: December 2003

In many organisms, depolarizing stimuli cause an increase in intraciliary Ca2+, which results in reversal of ciliary beat direction and backward swimming. The mechanism by which an increase in intraciliary Ca2+ causes ciliary reversal is not known. Here we show that Tetrahymena cells treated with okadaic acid or cantharidin to inhibit protein phosphatases do not swim backwards in response to depolarizing stimuli. We also show that both okadaic acid and cantharidin inhibit backward swimming in reactivated, extracted cell models treated with Ca2+. In contrast, treatment of whole cells or extracted cell models with protein kinase inhibitors has no effect on backward swimming. These results suggest that a component of the axonemal machinery is dephosphorylated during ciliary reversal. The phosphorylation state of inner arm dynein 1 (I1) was determined before and after cells were exposed to depolarizing conditions that induce ciliary reversal. An I1 intermediate chain is phosphorylated in forward swimming cells but is dephosphorylated in cells treated with a depolarizing stimulus. Our results suggest that dephosphorylation of Tetrahymena inner arm dynein 1 may be an essential part of the mechanism of ciliary reversal in response to increased intraciliary Ca2+. Cell Motil. Cytoskeleton 57:73–83, 2004. © 2004 Wiley‐Liss, Inc.
Overexpression of profilin reduces the migration of invasive breast cancer cells
Authors: Roy Partha , Jacobson Ken
Published: December 2003

The exact role profilin plays in cell migration is not clear. In this study, we have evaluated the effect of overexpression of profilin on the migration of breast cancer cells. Overexpression was carried out by stably expressing GFP‐profilin in BT474 cells. It was observed that even a moderate level of overexpression of profilin significantly impaired the ability of BT474 cells to spread on fibronectin‐coated substrate and migrate in response to EGF. GFP‐profilin expressing cells also showed increased resistance to detachment in response to trypsin and increased tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin compared to the parental and GFP‐expressing (control) cell lines. These results suggest that perturbation of profilin levels may offer a good strategy for controlling the metastatic potential of breast cancer cells. Cell Motil. Cytoskeleton 57:84–95, 2004. © 2004 Wiley‐Liss, Inc.