bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructure of sperm storage and male genital ducts in a male holocephalan, the elephant fish, Callorhynchus milii
Authors: Hamlett William C. , Reardon Matthew , Clark Joan , Walker Terence I. 
Published: August 2002

AbstractIn chondrichthyes, the process of spermatogenesis produces a spermatocyst composed of Sertoli cells and their cohort of associated spermatozoa linearly arrayed and embedded in the apical end of the Sertoli cell. The extratesticular ducts consist of paired epididymis, ductus deferens, isthmus, and seminal vesicles. In transit through the ducts, spermatozoa undergo modification by secretions of the extratesticular ducts and associated glands, i.e., Leydig gland. In mature animals, the anterior portion of the mesonephros is specialized as the Leydig gland that connects to both the epididymis and ductus deferens and elaborates seminal fluid and matrix that contribute to the spermatophore or spermatozeugmata, depending on the species. Leydig gland epithelium is simple columnar with secretory and ciliated cells. Secretory cells have periodic acid‐Schiff positive (PAS+) apical secretory granules. In the holocephalan elephant fish, Callorhynchus milii, sperm and Sertoli cell fragments enter the first major extratesticular duct, the epididymis. In the epididymis, spermatozoa are initially present as individual sperm but soon begin to laterally associate so that they are aligned head‐to‐head. The epididymis is a highly convoluted tubule with a small bore lumen and an epithelium consisting of scant ciliated and relatively more secretory cells. Secretory activity of both the Leydig gland and epididymis contribute to the nascent spermatophores, which begin as gel‐like aggregations of secretory product in which sperm are embedded. Fully formed spermatophores occur in the ductus. The simple columnar epithelium has both ciliated and secretory cells. The spermatophore is regionalized into a PAS+ and Alcian‐blue‐positive (AB+) cortex and a distinctively PAS+, and less AB+ medulla. Laterally aligned sperm occupy the medulla and are surrounded by a clear zone separate from the spermatophore matrix. Grossly, the seminal vesicles are characterized by spiral partitions of the epithelium that project into the lumen, much like a spiral staircase. Each partition is staggered with respect to adjacent partitions while the aperture is eccentric. The generally nonsecretory epithelium of the seminal vesicle is simple columnar with both microvillar and ciliated cells. J. Exp. Zool. 292:111–128, 2002. © 2002 Wiley‐Liss, Inc.
Radiohalogenated carbohydrates for use in PET and SPECT
Authors: Adam Michael J. 
Published: August 2002

AbstractRadiohalogenated carbohydrates have been of significant interest to the Nuclear Medicine community since the success of 2‐Deoxy‐2‐fluoro‐glucose (FDG)/positron emission tomography (PET) to measure glucose metabolic rates in humans. This review of this important class of compounds will be written in two parts, and will concentrate on the chemistry. The first part will cover the development of FDG, the many attempts to synthesize other radiohalogenated PET and SPECT analogs, and future prospects of a SPECT analog. The second will cover the synthesis of other radio‐halogenated carbohydrate compounds such as nucleosides, where the halogen is located on the sugar rings, as potential imaging or therapeutic agents. Copyright © 2002 John Wiley & Sons, Ltd.
Breath‐hold three‐dimensional true‐FISP imaging of coronary arteries using asymmetric sampling
Authors: Deshpande Vibhas S. , Shea Steven M. , Chung Yiu Cho , McCarthy Richard M. , Finn J. Paul , Li Debiao 
Published: August 2002

AbstractPurposeTo evaluate the feasibility of using asymmetric sampling in a three‐dimensional, magnetization‐prepared, segmented true‐FISP (fast imaging with steady‐state precession) sequence in order to reduce the sensitivity to resonance offsets, while simultaneously improving imaging speed.Materials and MethodsAsymmetric sampling reduces the repetition time, leading to reduced resonance offset effects and improved resolution in a fixed imaging time. However, it introduces additional phase terms due to blood flow, which can cause image artifacts. Computer simulations were performed to study the off‐resonance and flow effects of asymmetric sampling in true‐FISP. Coronary artery imaging was performed in healthy volunteers.ResultsSimulations and volunteer studies show that image artifacts due to flow‐induced phase variations may be acceptable at low velocities. Volunteer studies demonstrate that relatively high‐resolution coronary artery images can then be acquired within a single breath‐hold with segmented three‐dimensional true‐FISP imaging using data asymmetry in the readout direction.ConclusionAsymmetric sampling is a useful modification to true‐FISP for reducing the off‐resonance artifacts and improving imaging speed when the flow velocities are small. J. Magn. Reson. Imaging 2002;15:473–478. © 2002 Wiley‐Liss, Inc.
Pelvic lymph node visualization with MR imaging using local administration of ultra‐small superparamagnetic iron oxide contrast
Authors: McCauley Thomas R. , Rifkin Matthew D. , Ledet Cheryl A. 
Published: August 2002

AbstractPurposeTo determine if interstitial injection of iron oxide particles improves visualization of pelvic lymph nodes at magnetic resonance imaging (MRI) and to determine the effect of injection site on location of visualized nodes.Materials and MethodsIn nine healthy volunteers, ferumoxtran‐10 iron oxide (0.28 mg iron per kg) was injected into the anterior thigh (three subjects) or perianal (three subjects) or periprostatic tissues (three subjects). MRI at 1.5 T was performed before injection and one, three, and seven days after injection.ResultsThe mean of 30 nodes seen post‐injection was greater than the mean of 5.8 seen pre‐injection (P < 0.001). After thigh injection, a mean of three internal vs. 36 external nodes were seen. Compared with thigh injection, there was a higher fraction of internal nodes with perianal (mean of nine internal vs. 14 external, P < 0.001) and periprostatic injection (mean of 11 internal vs. five external, P < 0.001). More nodes were seen with gradient‐echo sequences than with other sequences (P < 0.001).ConclusionInterstitial injection of iron oxide particles increases visualization of pelvic lymph nodes. Perianal and periprostatic injection increases the number of internal pelvic lymph nodes seen compared with thigh injection. J. Magn. Reson. Imaging 2002;15:492‐497. © 2002 Wiley‐Liss, Inc.
Effects of indomethacin on cerebral blood flow at rest and during hypercapnia: An arterial spin tagging study in humans
Authors: St. Lawrence Keith S. , Ye Frank Q. , Lewis Bobbi K. , Weinberger Daniel R. , Frank Joseph A. , McLaughlin Alan C. 
Published: August 2002

AbstractPurposeTo investigate using an arterial spin tagging (AST) approach the effect of indomethacin on the cerebral blood flow (CBF) response to hypercapnia.Materials and MethodsSubjects inhaled a gas mixture containing 6% CO2 for two 5‐minute periods, which were separated by a 10‐minute interval, in which subjects inhaled room air. In six subjects, indomethacin (i.v., 0.2 mg/kg) was infused in the normocapnic interval between the two hypercapnic periods.ResultsIndomethacin reduced normocapnic gray matter CBF by 36 ± 5% and reduced the CBF increase during hypercapnia from 43 ± 9% to 16 ± 5% in gray matter (P < 0.001) and from 48 ± 11% to 35 ± 9% in white matter (P < 0.025).ConclusionThe results demonstrate that an AST approach can measure the effects of indomethacin on global CBF increases during hypercapnia and suggest that an AST approach could be used to investigate pharmacological effects on focal CBF increases during functional activation. J. Magn. Reson. Imaging 2002;15:628–635. Published 2002 Wiley‐Liss, Inc.
Staging endometrial cancer: Role of magnetic resonance imaging
Authors: Frei Kathrin A. , Kinkel Karen 
Published: August 2002

AbstractThis review article summarizes and comments the role of magnetic resonance imaging (MRI) in the management of endometrial cancer. The MRI technique, appearance, and diagnostic criteria of endometrial carcinoma are discussed. The value of MRI in the preoperative staging of endometrial cancer is compared to alternative strategies. Contrast‐enhanced MRI performs best in the pretreatment evaluation of myometrial or cervical invasion, compared to ultrasonography (US), computed tomography (CT), or nonenhanced MRI. The overall costs and accuracy are similar to those of the current methods of staging, including intraoperative gross dissection of the uterus. In addition, results of MRI might decrease the number of unnecessary lymph node dissections. J. Magn. Reson. Imaging 2001;13:850–855. © 2001 Wiley‐Liss, Inc.
Use of L‐[15N] glutamic acid and homoglutathione to determine both glutathione synthesis and concentration by gas chromatography‐mass spectrometry (GCMS)
Authors: Humbert Bernard , Nguyen Patrick , Obled Christiane , Bobin Christine , Vaslin Anne , Sweeten Shawn , Darmaun Dominique 
Published: August 2002

AbstractA method for simultaneous measurement of both glutathione enrichment and concentration in a biological sample using gas chromatography mass spectrometry is described. The method is based on the preparation of N,S‐ethoxycarbonylmethyl ester derivatives of glutathione, and the use of homoglutathione (glutamyl–cysteinyl–alanine) as an internal standard. A procedure for determination of glutamate concentration and enrichment is also reported. Both methods have within‐day and day‐to‐day inter‐assay coefficients of variation less than 5%, and recoveries of known added amounts of glutathione and glutamate are close to 100%. Taken together, these methods allowed determination of glutathione concentration and fractional synthesis rate in red blood cells using L‐[15N] glutamic acid infusion. This approach was applied in vivo to investigate the effects of a 72 h fast, compared with a control overnight fast, on erythrocyte glutathione in a single dog. The 72 h fast was associated with a 39% decline in erythrocyte glutathione level, (2.9 ± 0.4 versus 4.7 ± 0.5 mmol l−1, fasting versus control) with no change in glutathione fractional synthesis (67.4 versus 71.3% d−1, fasting versus control). Copyright © 2001 John Wiley & Sons, Ltd.
Liquid chromatographic/mass spectrometric detection of the 3‐(3‐hydroxyalkanoyloxy) alkanoic acid precursors of rhamnolipids in Pseudomonas aeruginosa cultures
Authors: Lépine François , Déziel Eric , Milot Sylvain , Villemur Richard 
Published: August 2002

AbstractA series of pseudomolecular and fragment ions attributed to 3‐(3‐hydroxyalkanoyloxy)alkanoic acids (HAAs) were detected by liquid chromatography/mass spectrometry among the rhamnolipids observed in a Pseudomonas aeruginosa strain 57RP supernatant. The fragmentation mechanism leading to the formation of the fragment ions was determined by a deuterium exchange experiment and by using a standard HAA mixture obtained from the mild acidic hydrolysis of rhamnolipids of known composition. The structure and the response factor of these free HAAs were determined. The HAAs relative composition differs between free HAAs and those present in rhamnolipids, the former being enriched in lower molecular mass congeners and depleted in the heavier ones. Within an isomeric pair, the isomer with the shortest 3‐hydroxyalkaloyl residue at the hydroxyl end was more abundant than the one with the heavier 3‐hydroxyalkaloyl acid at this position, and the ratios of their relative abundances were similar for free HAAs and those in rhamnolipids. Experiments with deuterium‐labeled rhamnolipids demonstrated that free HAAs are part of a pool used for rhamnolipid biosynthesis and are not rhamnolipid degradation products. Copyright © 2001 John Wiley & Sons, Ltd.
Selective incorporation of isotopically labeled amino acids for identification of intact proteins on a proteome‐wide level
Authors: Martinović Suzana , Veenstra Timothy D. , Anderson Gordon A. , Paša‐Tolić Ljiljana , Smith Richard D. 
Published: August 2002

AbstractThe post‐genomic era and increased demands for broad proteome measurements have greatly increased the needs for protein identification. We describe a strategy that uses accurate mass measurements and partial amino acid content information to unambiguously identify intact proteins, and show its initial application to the proteomes of Escherichia coli and Saccharomyces cerevisiae. Proteins were extracted from the organisms grown in minimal medium or minimal medium to which isotopically labeled leucine (Leu‐D10) had been added. The two protein extracts were mixed and analyzed by capillary isoelectric focusing (CIEF) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR). The incorporation of the isotopically labeled residue has no effect on the CIEF separation of proteins, and both isotopically labeled and unlabeled versions of specific proteins are observed within the same mass spectrum. The difference in the mass of the unlabeled and labeled proteins is used to determine the number of Leu residues present in a particular protein. Proteins can then often be unambiguously identified based on their accurately determined molecular mass and the additional constraint provided by number of Leu residues. The identities of proteins were further confirmed by repeating CIEF/FTICR measurements with samples that contain other isotopically labeled amino acid residues (e.g. His, Arg, Ile, Phe, Lys). A theoretical study of the amino acid composition (for a difference in the amino acid sequence) showed the constraints needed in order to identify the protein unambiguously. Additionally, the mass differences between the predicted and the experimental accurate mass measurement provide insights into the nature of simple post‐translational modifications. Copyright © 2001 John Wiley & Sons, Ltd.
Community‐based seroepidemiological survey of HCV infection in Catalonia, Spain
Authors: Domínguez Àngela , Bruguera Miquel , Vidal Josep , Plans Pere , Salleras Lluís 
Published: August 2002

AbstractThe objective of this study was to investigate the prevalence of antibodies against the hepatitis C virus (anti‐HCV) and the associated risk factors in a representative sample of the population of Catalonia, Spain. Serum samples from 2,142 subjects aged between 5 and 70 years, selected at random from urban and rural habitats, were studied. Multiple logistic regression analysis was carried out to determine variables associated independently with the presence of HCV antibodies. The age and gender standardized prevalence of anti‐HCV was 2.5% (95% confidence interval, 1.8–3.2). Prevalence increased significantly with age (P < 0.001), but no other sociodemographic variables were associated with HCV infection. Tattoos (OR: 6.2), blood transfusions (OR: 5.0) intravenous drug use (OR: 4.9) and antecedents of hospitalization (OR: 2.3) were variables associated independently with infection. HCV infection affects mainly elderly people in Spain and spares children and adolescents. This suggests that major exposure to HCV may have occurred many years ago, when infection was more widespread than in recent years. J. Med. Virol. 65:688–693, 2001. © 2001 Wiley‐Liss, Inc.
Viral vector‐mediated delivery of competing glycosyltransferases modifies epitope expression cell specifically
Authors: Baboval Thia , Liang ShuLing , Smith Frances I. 
Published: August 2002

AbstractThe glycoconjugate epitopes 3‐fucosyl‐N‐acetyllactosamine (CD15) and sulfoglucuronylcarbohydrate (SGC) mediate cell adhesion events in several systems, and are regulated both spatially and temporally during cerebellar development. In cotransfection studies using COS‐1 cells, competition between glycosyltransferases that utilize a common precursor involved in the final synthetic steps of these epitopes, can modulate epitope expression. For example, cotransfection of rat α1,3‐fucosyltransferase IV (Fuc‐TIV) and either rat glucuronic acid transferase P (GlcAT) or pig α1,3‐galactosyltransferase (GalT) resulted in the dominance of either SGC or GalαGal epitope expression, respectively, with blockage of CD15 epitope expression. Viral vectors expressing these glycosyltransferases were used to determine whether competition plays a role in establishing epitope dominance in cerebellar cells, and whether overexpression of competing glycosyltransferases could be used to block epitope expression. Infection of cerebellar astrocytes with viral vectors expressing either Fuc‐TIV, or Fuc‐TIX, caused dramatic increases in CD15 expression in the presence of continued endogenous SGC epitope expression. Likewise, viral transduction with GalT resulted in GalαGal expression without affecting endogenous CD15 or SGC expression. Thus, competition between these enzymes does not appear to play a role in establishing epitope expression in astrocytes, and transduction of these enzymes does not provide a method of blocking the expression of endogenous epitopes. In contrast to what was observed for astrocytes, infection with viral vectors expressing either Fuc‐T, GlcAT, or GalT did not result in significant expression of the relevant epitopes (CD15, SGC or GalαGal, respectively) on granule neurons. These results suggest a different complement of precursors are present in granule neurons and astrocytes, presumably due to the presence of different complements of glycosyltransferases in these cells. © 2002 Wiley‐Liss, Inc.
Identification of neuronal cell lineage‐specific molecules in the neuronal differentiation of P19 EC cells and mouse central nervous system
Authors: Kotani Masaharu , Osanai Taka , Tajima Youichi , Kato Hiroko , Imada Masato , Kaneda Hideki , Kubo Hideo , Sakuraba Hitoshi 
Published: August 2002

AbstractP19 embryonic carcinoma (EC) cells are one of the simplest systems for analyzing the neuronal differentiation. To identify the membrane‐associated molecules on the neuronal cells involved in the early neuronal differentiation in mice, we generated two monoclonal antibodies, SKY‐1 and SKY‐2, by immunizing rats with a membrane fraction of the neuronally committed P19 EC cells as an antigen. SKY‐1 and SKY‐2 recognized the carbohydrate moiety of a 90 kDa protein (RANDAM‐1) and the polypeptide core of a 40 kDa protein (RANDAM‐2), respectively. In the P19 EC cells, the expression of RANDAM‐1 was colocalized to a part of Nestin‐positive cells, whereas that of RANDAM‐2 was observed in most Nestin‐positive cells as well as β‐III‐tubulin positive neurons. In the embryonic and adult brain of mice, RANDAM‐1 was expressed at embryonic day 8.5 (E8.5), and the localization of antigen was restricted on the neuroepithelium and choroid plexus. The RANDAM‐2 expression commenced at E6.0, and the antigen was distributed not only on the neuroepithelium of embryonic brain but on the neurons of adult brain. Collectively, it was concluded that RANDAM‐1 is a stage specific antigen to express on the neural stem cells, and RANDAM‐2 is constitutively expressed on both the neural stem cells and differentiated neuronal cells in mouse central nervous system (CNS). © 2002 Wiley‐Liss, Inc.
Erythropoietin protects neurons against chemical hypoxia and cerebral ischemic injury by up‐regulating Bcl‐xL expression
Authors: Wen Tong‐Chun , Sadamoto Yasutaka , Tanaka Junya , Zhu Peng‐Xiang , Nakata Kimihiko , Ma Yong‐Jie , Hata Ryuji , Sakanaka Masahiro 
Published: August 2002

AbstractErythropoietin (EPO) promotes neuronal survival after cerebral ischemia in vivo and after hypoxia in vitro. However, the mechanisms underlying the protective effects of EPO on ischemic/hypoxic neurons are not fully understood. The present in vitro experiments showed that EPO attenuated neuronal damage caused by chemical hypoxia at lower extracellular concentrations (10−4–10−2 U/ml) than were previously considered. Moreover, EPO at a concentration of 10−3 U/ml up‐regulated Bcl‐xL mRNA and protein expressions in cultured neurons. Subsequent in vivo study focused on whether EPO rescued hippocampal CA1 neurons from lethal ischemic damage and up‐regulated the expressions of Bcl‐xL mRNA and protein in the hippocampal CA1 field of ischemic gerbils. EPO was infused into the cerebroventricles of gerbils immediately after 3 min of ischemia for 28 days. Infusion of EPO at a dose of 5 U/day prevented the occurrence of ischemia‐induced learning disability. Subsequent light microscopic examinations showed that pyramidal neurons in the hippocampal CA1 field were significantly more numerous in ischemic gerbils infused with EPO (5 U/day) than in those receiving vehicle infusion. The same dose of EPO infusion caused significantly more intense expressions of Bcl‐xL mRNA and protein in the hippocampal CA1 field of ischemic gerbils than did vehicle infusion. These findings suggest that EPO prevents delayed neuronal death in the hippocampal CA1 field, possibly through up‐regulation of Bcl‐xL, which is known to facilitate neuron survival. © 2002 Wiley‐Liss, Inc.
Slow axonal transport of the cytosolic chaperonin CCT with Hsc73 and actin in motor neurons
Authors: Bourke Gregory J. , El Alami Wathik , Wilson Suzanne J. , Yuan Aidong , Roobol Anne , Carden Martin J. 
Published: August 2002

AbstractMolecular chaperones are well known for their role in facilitating the folding of nascent and newly synthesized proteins, but have other roles, including the assembly, translocation and renaturation of intracellular proteins. Axons are convenient tissues for the study of some of these other roles because they lack the capacity for significant protein synthesis. We examine the axonal transport of the cytosolic chaperonin containing T‐ complex polypeptide 1 (CCT) by labeling lumbar motor neurons with [35S]methionine and examining sciatic nerve proteins by 2‐D gel electrophoresis and immunoblotting. All CCT subunits identifiable with specific antibodies, namely CCTα, CCTβ, CCTγ and CCTϵ/CCTθ (the latter two subunits colocalized in analyses of rat nerve samples), appeared to be labeled in “slow component b” of axonal transport along with the molecular chaperone Hsc73 and actin, a major folding substrate for CCT. Our results are consistent with molecular chaperones having a post‐translational role in maintaining the native form of actin during its slow transport to the axon terminal and ensuring its correct assembly into microfilaments. © 2002 Wiley‐Liss, Inc.
Subcellular localization and detergent solubility of MVP17/rMAL, a lipid raft‐associated protein in oligodendrocytes and myelin
Authors: Kim Taeyoon , Pfeiffer Steven E. 
Published: August 2002

AbstractDetergent‐insoluble, glycosphingolipid‐cholesterol‐enriched microdomains (lipid rafts) have been implicated in both protein trafficking and signal transduction. Previously we identified in oligodendrocytes and myelin the lipid raft‐associated, integral membrane protein myelin vesicular protein of 17 kDa (MVP17)/rMAL. Here we have examined the subcellular localization and/or detergent insolubility of native and recombinant MVP17/rMAL in transfected oligodendrocytes and COS‐7 cells and purified myelin. Consistent with our previous report regarding the insolubility of MVP17/rMAL in the zwitterionic detergent 3‐[(3‐chloramidopropyl)‐dimethylammonio]‐1‐propane‐sulfonate (CHAPS), MVP17/rMAL from purified myelin and oligodendrocytes in culture was mostly insoluble upon extraction at 4°C with the non‐ionic detergent Triton X‐100 and floated to a low density in sucrose gradient ultracentrifugation, but became detergent soluble at 37°C. Data obtained by immunofluorescence microscopy of the expression of epitope‐tagged MVP17/rMAL transfected into oligodendrocytes and COS‐7 cells were consistent with a model in which both the N‐ and C‐termini of this protein face the cytoplasm. Mutational analysis identified domains of MVP17/rMAL important for its subcellular localization and for its detergent solubility profile. In particular, insertional mutagenesis of loop II prevented the insertion of the mutant protein into the plasma membrane of COS‐7 cells and rendered it insoluble in TX‐100. Expression of full‐length constructs of MVP17/rMAL in COS‐7 cells resulted in an enlargement of transfected COS‐7 cells, consistent with a proposed role of rMAL in vesicular trafficking. © 2002 Wiley‐Liss, Inc.