bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractThe 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

AbstractHerbal 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

AbstractA 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

AbstractChitosan 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

AbstractOn 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

AbstractThe 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

AbstractIn 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

AbstractUtilization 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

AbstractEtiological 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

AbstractThere 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractWe 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

AbstractCYP1A2 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

AbstractThe 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.