bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence of a common pathogenesis for foregut duplications and esophageal atresia with tracheo‐esophageal fistula
Authors: Qi Bao Quan , Beasley Spencer W. , Williams Andrew K. 
Published: September 2002

AbstractThe pathogenesis of the alimentary tract duplications, including foregut duplications (FgD) remains speculative. The accidental finding of FgD in fetal rats with esophageal atresia and tracheoesophageal fistula (EA‐TEF) induced by Adriamycin provided an animal model to investigate a possible relationship between these two entities. Timed‐pregnant rats were intraperitoneally injected with Adriamycin (1.75 mg/kg) on gestational Days 6 to 9. Their embryos were harvested by Caesarean section from gestational Days 14 to 21. Forty‐six of embryos were processed and serially sectioned in the transverse or sagittal planes. EA‐TEF occurred in 43/46 (93%) embryos of which 11 (24%) were found to have an associated FgD located at the level where the esophagus was absent. Six FgDs communicated with the foregut or the trachea. Five noncommunicating FgDs were located between the foregut and the vertebral column. In the control embryo, the notochord was located in the centre of the vertebral column from Day 11 of the gestation. In Day 14, 15 and 16, however, embryos exposed to Adriamycin, an abnormal notochord or branch frequently was located within the mesenchyme of the maldeveloped foregut or attached to the duplication cyst. In some, it appeared that the notochord was drawing the cyst‐like structure away from the foregut. The present study confirms that duplications adjacent to the esophagus arise from the foregut and that failure of the foregut to detach from the notochord at the normal time may contribute to the development of foregut duplications. Anat Rec 264:93–100, 2001. © 2001 Wiley‐Liss, Inc.
Human reserve pluripotent mesenchymal stem cells are present in the connective tissues of skeletal muscle and dermis derived from fetal, adult, and geriatric donors
Authors: Young Henry E. , Steele Timothy A. , Bray Robert A. , Hudson John , Floyd Julie A. , Hawkins Kristina , Thomas Karen , Austin Troy , Edwards Chris , Cuzzourt Jeremy , Duenzl Mary , Lucas Paul A. , Black Asa C. 
Published: September 2002

AbstractThis study details the profile of 13 cell surface cluster differentiation markers on human reserve stem cells derived from connective tissues. Stem cells were isolated from the connective tissues of dermis and skeletal muscle derived from fetal, mature, and geriatric humans. An insulin/dexamethasone phenotypic bioassay was used to determine the identity of the stem cells from each population. All populations contained lineage‐committed myogenic, adipogenic, chondrogenic, and osteogenic progenitor stem cells as well as lineage‐uncommitted pluripotent stem cells capable of forming muscle, adipocytes, cartilage, bone, fibroblasts, and endothelial cells. Flow cytometric analysis of adult stem cell populations revealed positive staining for CD34 and CD90 and negative staining for CD3, CD4, CD8, CD11c, CD33, CD36, CD38, CD45, CD117, Glycophorin‐A, and HLA DR‐II. Anat Rec 264:51–62, 2001. © 2001 Wiley‐Liss, Inc.
Ultrastructure of the embryonic stem cells of the 8‐day pig blastocyst before and after in vitro manipulation: Development of junctional apparatus and the lethal effects of PBS mediated cell–cell dissociation
Authors: Talbot Neil C. , Garrett Wesley M. 
Published: September 2002

AbstractUltrastructural examination of 8‐day hatched pig blastocysts (large and small), their cultured inner cell mass (ICM), and cultured epiblast tissue (embryonic stem cells) was undertaken to assess the development of epiblast cell junctions and cytoskeletal elements. In small blastocysts, epiblast cells had no desmosomes or tight junction (TJ) connections and few organized microfilament bundles, whereas in large blastocysts the epiblast cells were connected by TJ and desmosomes with associated microfilaments. ICM isolation by immunodissection damaged the endoderm cells beneath the trophectoderm cells but did not appear to damage the epiblast cells or their associated endoderm cells. Epiblast cells in cultured ICMs were similar in character to those in the intact large blastocyst except that perinuclear microfilaments were observed. Isolated pig epiblasts, cultured for ∼36 hr on STO feeder layers, formed a monolayer whose cells were connected by TJ, adherens junctions and desmosomes with prominent microfilament bundles running parallel to the apical cytoplasmic membranes. Perinuclear microfilaments were a consistent feature in the ∼36 hr cultured epiblast cells. A feature characteristic of differentiation into notochordal cells, i.e., a solitary cilium, was also observed in the cultured epiblast. Exposure of the cultured epiblast cells to Ca++‐Mg++‐free phosphate buffered saline (PBS) for 5–10 min resulted in extensive cell blebbing and lysis. The results may indicate that pig epiblast cells could be more easily dissociated from early blastocysts (∼400 μm in diameter) if immunodissection damage to the ICM can be avoided. It may be difficult, however, to establish them as embryonic stem cell lines because the cultured pig epiblast cells were easily lysed by standard cell–cell dissociation methods. Anat Rec 264:101–113, 2001. © 2001 Wiley‐Liss, Inc.
Resistance of the insect cell line IPLB‐LdFB to salsolinol‐induced apoptosis
Authors: Ottaviani Enzo , Nappi Anthony J. , Vass Emily 
Published: September 2002

AbstractApoptosis is a form of cell death that is manifested in Parkinson’s disease (PD) and certain other neurodegenerative disorders. Metabolites of salsolinol (SAL), an intraneuronal, dopamine‐derived tetrahydroisoquinoline (TIQ), have been shown to induce apoptosis in human dopaminergic neuroblastoma cells, implicating these molecules as causative or contributory factors in the selective killing of nigrostriatal dopaminergic neurons, a cardinal manifestation of Parkinson’s disease. Since insects employ dopamine and related catecholamines in a variety of processes including cuticular sclerotization and cellular immune reactions, it was of interest to know how insect cells metabolized exogenous SAL. Propidium iodide staining combined with flow cytometry showed that IPLB‐LdFB cells from Lymantria dispar exhibited no significant (P < 0.05) increase in apoptosis when incubated for 48 h with concentrations of SAL ranging from 10 μM to 1 mM. A significant increase in apoptosis (P < 0.05) was observed in cell cultures containing the highest concentration of SAL tested (5 mM), but only 12.4% of the cells manifested this form of cell death. High pressure liquid chromatography with electrochemical detection (HPLC‐ED) was used to document the production of two potentially cytotoxic quinonoids generated during the autoxidation of SAL, a reaction that was found to be significantly (P < 0.05) enhanced by peroxidase. The resistance of IPLB‐LdFB cells to SAL‐induced apoptosis is attributed to the ability of these insect cells to metabolize and/or detoxify such dopamine‐derived catecholic TIQs. Thus, the biochemical pathways employed by insect cells in these processes may be of considerable interest to individuals investigating certain neurodegenerative disorders. Arch. Insect Biochem. Physiol. 49:1–9, 2002. © 2002 Wiley‐Liss, Inc.
Dose‐dependent pharmacokinetics of a new neuroprotective agent for ischemia‐reperfusion damage, KR‐31378, in rats
Authors: Kim Hee J. , Kim So H. , Kim Sun‐O. , Lee Dong‐H. , Lim Hong , Yoo Sung‐E. , Lee Myung G. 
Published: September 2002

AbstractThe dose‐dependent pharmacokinetic parameters of a new neuroprotective agent for ischemia‐reperfusion damage, KR‐31378, were evaluated after intravenous and oral administration, 10, 20, and 50 mg/kg, to rats. After intravenous administration of 50 mg/kg, the dose‐normalized (10 mg/kg) AUC (994 µg min/mL) was significantly greater than that at 10 (569 µg min/ml) and 20 (660 µg min/mL) mg/kg. This could be due to slower clearance (Cl) with increasing dosage (18.5, 14.6, and 10.2 mL/min/kg for 10, 20, and 50 mg/kg, respectively). The slower Cl with increasing dosage could be due to saturable metabolism of KR‐31378 in rats and this could be supported by significantly slower Clnr and significantly greater 24‐h urinary excretion of the drug at 50 mg/kg than those at 10 and 20 mg/kg. After oral administration of 50 mg/kg, the dose‐normalized (10 mg/kg) AUC (1160 µg min/mL) was significantly greater than that at 10 (572 µg min/mL) and 20 (786 µg min/mL) mg/kg. Note that the AUCs were comparable (not significantly different) between intravenous and oral administration at each dosage, indicating that the absorption from gastrointestinal tract was almost complete and the first‐pass (gastric, intestinal, and hepatic) effect was not considerable after oral administration to rats. Copyright © 2000 John Wiley & Sons, Ltd.
Theoretical pharmacokinetic and pharmacodynamic simulations of drug delivery mediated by blood–brain barrier transporters
Authors: Mahar Doan Kelly M. , Boje Kathleen M. K. 
Published: September 2002

AbstractPharmacokinetic/pharmacodynamic simulations were performed to assess the feasibility of central nervous system (CNS) drug delivery via endogenous transporters resident at the blood–brain barrier (BBB). Pharmacokinetic models were derived for intravenous bolus dosing of a hypothetical drug in the absence or presence of an endogenous, competing transport inhibitor. These models were linked to CNS pharmacodynamic models where the effect sites were either cell surface receptors or intracellularly localized enzymes. The response of the dependent parameter, the duration of effect (tdur), was examined in relationship to changes in the independent parameters, i.e. dose, elimination rate constant (ke1), BBB transport parameters (Km1 and Vmax1) and EC50 (effective concentration that elicits a 50% response). As expected, tdur increased with (a) increases in drug doses, (b) decreases in ke1 or (c) decreases in EC50, irrespective of the effect site. Surprisingly, endogenous transport inhibition produced decreases in drug terminal half‐life and corresponding decreases in tdur. Interestingly, tdur was independent of assigned transporter Km and Vmax when the dose/EC50 ratio (dose/EC50) was >1 (irrespective of endogenous transport inhibition), but highly dependent on Km1 and Vmax1 when dose/EC50 was (a) <1 (no endogenous transport inhibition) or (b) equal to 1 (with endogenous transport inhibition). Oral input of the endogenous transport inhibitor produced a decrease in tdur when the dose/EC50 range was 0.1–10. These simulations highlight that (a) systemic pharmacokinetic and BBB transport parameters influence tdur, (b) drug terminal half‐life is inversely related to circulating levels of endogenous inhibitors, and (c) oral ingestion of endogenous transport inhibitor(s) reduces tdur. Overall, these simulations provide insight for the feasibility of rational CNS drug design/delivery via endogenous transporters. Copyright © 2000 John Wiley & Sons, Ltd.
Why girls want to be boys
Authors: Beukeboom Leo W. , de Jong Tom J. , Pen Ido 
Published: September 2002

AbstractThe mechanisms by which sex is genetically determined are bewilderingly diverse and appear to change rapidly during evolution.(1) What makes the sex‐determining process so prone to perturbations? Two recent articles(2,3) explore theoretically the role of genetic conflict in sex determination evolution. Both studies use the idea that selection on sex‐determining genes may act differently in parents and in offspring and they suggest that the resulting conflict can drive changes in sex‐determining mechanisms. BioEssays 23:477–480, 2001. © 2001 John Wiley & Sons, Inc.
It ain't over till it's ova: germline sex determination in C. elegans
Authors: Kuwabara Patricia E. , Perry Marc D. 
Published: September 2002

AbstractSex determination in most organisms involves a simple binary fate choice between male or female development; the outcome of this decision has profound effects on organismal biology, biochemistry and behaviour. In the nematode C. elegans, there is also a binary choice, either male or hermaphrodite. In C. elegans, distinct genetic pathways control somatic and germline sexual cell fate. Both pathways share a common set of globally acting regulatory genes; however, germline‐specific regulatory genes also participate in the decision to make male or female gametes. The determination of sexual fate in the germline of the facultative hermaphrodite poses a special problem, because first sperm then oocytes are produced. It has emerged that additional layers of post‐transcriptional regulation have been imposed to modulate the activities of the global sex‐determining genes, tra‐2 and fem‐3; the balance between these activities is crucial in controlling sexual cell fate in the hermaphrodite germline. BioEssays 23:596–604, 2001. © 2001 John Wiley & Sons, Inc.
Pathways to photoreceptor cell death in inherited retinal degenerations
Authors: Pierce Eric A. 
Published: September 2002

AbstractThe mutations that cause many forms of inherited retinal degenerations have been identified, yet the mechanisms by which these mutations lead to death of photoreceptor cells of the retina are not completely understood. Investigations of the pathways from mutation to retinal degeneration have focused on spontaneous and engineered animal models of disease. Based on the studies performed to date, four major categories of degeneration mechanism can be identified. These include disruption of photoreceptor outer segment morphogenesis, metabolic overload, dysfunction of retinal pigment epithelial cells, and chronic activation of phototransduction. Future investigations will likely identify additional mechanisms of photoreceptor damage. This review will summarize what has been learned from studying animal models of non‐syndromic inherited retinal degenerations. BioEssays 23:605–618, 2001. © 2001 John Wiley & Sons, Inc.
Ethylene hormone receptor action in Arabidopsis
Authors: Chang Caren , Stadler Ruth 
Published: September 2002

AbstractSmall gaseous molecules play important roles in biological signaling in both animal and plant physiology. The hydrocarbon gas ethylene has long been known to regulate diverse aspects of plant growth and development, including fruit ripening, leaf senescence and flower abscission. Recent progress has been made toward identifying components involved in ethylene signal transduction in the plant Arabidopsis thaliana. Ethylene is perceived by five receptors that have similarity to two‐component signaling proteins. The hydrophobic amino‐terminus of the receptors binds ethylene, and mutations in this domain both prevent ethylene binding and confer ethylene insensitivity to the plant; the carboxyl‐terminal portion of the receptors has similarity to bacterial his tidine protein kinases. Genetic data suggest a model in which ethylene binding inhibits receptor signaling, yet precisely how these receptors function is unclear. Two of the receptors have been found to associate with a negative regulator of ethylene responses called CTR1, which appears to be a mitogen‐activated protein kinase (MAPK) kinase kinase. BioEssays 23:619–627, 2001. © 2001 John Wiley & Sons, Inc.
Utilizing genetically engineered bacteria to produce plant‐specific glucosides
Authors: Arend Joachim , Warzecha Heribert , Hefner Tobias , Stöckigt Joachim 
Published: September 2002

AbstractPlant‐derived glucosides have attracted much attention due to their widespread applications. This class of products is difficult to isolate or to synthesize in pure form because of the resulting low yields. Thus, simple approaches for the generation of such glucosides would be highly beneficial. We purified and characterized a novel glucosyltransferase from plant cell suspension cultures of Rauvolfia serpentina, which showed rather low substrate specificity. We obtained its cDNA and expressed the active recombinant protein in bacteria (Escherichia coli) with excellent plant‐specific glucosylation efficiencies. Compared with the plant system, the bacteria delivered the new enzyme, which was in the form of a soluble or matrix‐bound enzyme, approximately 1800 times more efficiently for the synthesis of a wide range of glucosides. More importantly, the engineered E. coli strain allowed for in vivo glucosylation and release of the product into the culture medium, as shown by the formation of arbutin, which is a potent inhibitor of human melanin biosynthesis with commercial value. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 76: 126–131, 2001.
Three novel high performance affinity chromatographic media for the separation of antithrombin III from human plasma
Authors: Zhao Yingxin , Zhao Rui , Shangguan Dihua , Xiong Shaoxiang , Liu Guoquan 
Published: September 2002

AbstractNovel monodisperse, non‐porous, cross‐linked poly (glycidyl methacrylate) beads (PGMA) were employed as the support for high performance affinity chromatography. Heparin was covalently attached to PGMA beads by three different coupling methods. Heparin‐PGMA‐I was prepared by directly coupling amino‐groups of heparin with PGMA. Heparin‐PGMA‐II and III were prepared by the coupling of heparin to amino‐PGMA, which was obtained by amination of PGMA. Heparin‐PGMA‐II was prepared by coupling the carboxyl groups of heparin to amino‐PGMA by using water‐soluble carbodiimide as coupling reagent, and heparin‐PGMA‐III was prepared by the reductive amination of heparin and amino‐PGMA with sodium cyanoborohydride. The heparin contents of heparin‐PGMA‐I, II and III were 1.6, 10.2 and 1.0 mg/g beads, respectively. Their affinity capacities for antithrombin III were investigated. Their binding activity to antithrombin III was not proportional to the content of heparin immobilized, and heparin‐PGMA‐I was the most efficient affinity medium for antithrombin III. The resultant affinity media presented minimal non‐specific interaction with other proteins and can be used in a wide pH range. All the three heparin‐PGMA beads were exploited for the separation of antithrombin III from human plasma. The purity of antithrombin III obtained was higher than 90%, which was confirmed by high performance size exclusion chromatography. Copyright © 2001 John Wiley & Sons, Ltd.
Quantitative determination of nitrendipine and its metabolite dehydronitrendipine in human plasma using liquid chromatography–tandem mass spectrometry
Authors: Chen Xiaoyan , Zhong Dafang , Yang Hanyu , Luan Yan , Xu Haiyan 
Published: September 2002

AbstractA sensitive and high‐throughput LC‐MS‐MS method was developed for simultaneous determination of nitrendipine (NIT) and its major metabolite, dehydronitrendipine (DNIT) in human plasma using nifedipine as the internal standard. Plasma samples were prepared based on a simple liquid–liquid extraction. The extracted samples were analyzed on a Zorbax SB C18 column interfaced with a triple quadrupole tandem mass spectrometer. Positive atmospheric pressure chemical ionization was employed as the ionization source. The analytes were detected by use of selected reaction monitoring mode. Standard curves were linear (r ≥ 0.995) over the concentration range of 0.4–40 ng/mL for NIT and 0.2–20 ng/mL for DNIT. The intra‐ and inter‐run precision was measured to be below 8.5% for NIT and DNIT. The inter‐run accuracy was less than 4% for the analytes. The overall extraction recoveries of NIT and DNIT were determined to be about 75% and 78% on average, respectively. The chromatographic run time was approximately 3 min. More than 120 samples could be assayed daily with this method, including sample preparation, data acquisition and processing. The method developed was successfully used to investigate plasma concentrations of NIT and DNIT in a pharmacokinetic study of volunteers who received NIT orally. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of clarithromycin in human plasma by HPLC with electrochemical detection: validation and application in pharmacokinetic study
Authors: Niopas Ioannis , Daftsios Athanasios C. 
Published: September 2002

AbstractA rapid, specific, precise and accurate HPLC method with electrochemical detection was developed and validated for the determination of clarithromycin in human plasma. After addition of the internal standard, the analytes were extracted from plasma under alkaline conditions with ethyl acetate:hexane 1:1. The inter‐run precision of the method was less than 4.7%, the inter‐run accuracy was better than 97.3% and the recovery of clarithromycin and roxithromycin (internal standard) were better than 82.5% and 86.2%, respectively. The method was found to be suitable for the quantitation of clarithromycin in bioequivalence and pharmacokinetic studies. Copyright © 2001 John Wiley & Sons, Ltd.
Inspection of the reversal of enantiomer migration order in ligand exchange micellar electrokinetic capillary chromatography
Authors: Lin Jin‐Ming , Hobo Toshiyuki 
Published: September 2002

AbstractEnantiometers of D,L‐phenylalanine were separated by capillary electrophoresis based on the principle of ligand exchange. Copper (II) complex of 4‐hydroxy‐L‐proline was used as chiral selector. The separation and the migration order of D‐ and L‐phenylalanine were strongly affected by adding an anion surfactant sodium dodecylsulfate (SDS). Without SDS in the electrolyte, the separation was also carried out but the resolution was very small. With SDS added into the electrolyte, the resolution decreased with increasing concentration of SDS until 5.0 mM. When the concentration of SDS in the electrolyte was over 5.0 mM, inversion of the migration order of DL‐phenylalanine was observed and the resolution was also increased with increasing concentration up to 20 mM. It was interesting to find that the inversion of the migration order took place not only in the enantioscparation but also in the positional isomers. A family of a fluorinated amino acid, o‐, m‐ and p‐fluoro‐D,L‐phenylalanine was separated and the inversion of the migration order is discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Combined percutaneous biosense‐guided laser myocardial revascularization and coronary intervention
Authors: Laham Roger J. , Baim Donald S. 
Published: September 2002

AbstractLaser myocardial revascularization is a promising new treatment strategy for patients with severe ischemic heart disease who are not candidates for conventional percutaneous or surgical revascularization. The open chest surgical approach to transmyocardial revascularization has been approved by the FDA for the treatment of angina in inoperable patients, but has had limited use as a stand‐alone procedure. More recently, use of fiber‐optic catheters has made it possible to use a holmium:yttrium aluminum garnet laser to perform percutaneous catheter‐based transmyocardial revascularization. To the extent that many patients have a combination of ischemic sources, some amenable to conventional revascularization and some not, combination or hybrid approaches have been considered. We report herein two patients with class IV angina who underwent laser myocardial revascularization using the Biosense system and complex percutaneous coronary intervention during the same procedure. Areas amenable to conventional percutaneous coronary intervention (PCI) were so treated, and viable but ischemic areas were supplied by totally occluded native vessels and bypass grafts underwent Biosense‐guided laser myocardial revascularization (LMR). As the results of more controlled and blinded studies of laser myocardial revascularization become available (if results continue to be promising) and a better understanding of the mechanism of action of this treatment modality is achieved, LMR‐PTCA hybrid will be performed in increasing frequency. However, even after establishing LMR efficacy, studies of LMR‐PTCA hybrid should be conducted to determine the efficacy of this approach. Cathet Cardiovasc Intervent 2001;53:235–240. © 2001 Wiley‐Liss, Inc.