bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell‐free protein synthesis inhibition assay for the cyanobacterial toxin cylindrospermopsin
Authors: Froscio Suzanne M. , Humpage Andrew R. , Burcham Philip C. , Falconer Ian R. 
Published: August 2002

AbstractThe cyanobacterial toxin cylindrospermopsin (CYN) is known to be a potent inhibitor of protein synthesis. This paper describes the use of a rabbit reticulocyte lysate translation system as a protein synthesis inhibition assay for CYN. A dose response curve for protein synthesis inhibition by CYN was constructed and was modeled to a sigmoidal dose response curve with variable slope (R2=0.98). In this assay, CYN has an IC50 of 120 nM [95% chemical interaction (CI)=111−130 nM] with a detection limit in the region of 50 nM in the assay solution. Application of the assay allows quantification of toxin samples within the range 0.5–3.0 μM (200–1200 μg/L) CYN. To assess the usefulness of this assay, a range of toxic and nontoxic Cylindrospermopsis raciborskii extracts, including both laboratory strains and environmental samples, were assayed by protein synthesis inhibition. These CYN quantifications were then compared to quantifications obtained by high performance liquid chromatography (HPLC) and HPLC‐tandem mass spectrometry (HPLCMS–MS). The results demonstrate that the protein synthesis inhibition assay correlates well with both HPLCMS–MS (r2=0.99) and HPLC (r2=0.97) quantifications. We conclude that this is an accurate and rapid assay for the measurement of cylindrospermopsin in cyanobacterial extracts. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 408–412, 2001
Identification of genes implicated in toxin production in the cyanobacterium Cylindrospermopsis raciborskii
Authors: Schembri Mark A. , Neilan Brett A. , Saint Christopher P. 
Published: August 2002

AbstractCylindrospermopsis raciborskii is a bloom‐forming cyanobacterium found in both tropical and temperate climates which produces cylindrospermopsin, a potent hepatotoxic secondary metabolite. This organism is notorious for its association with a significant human poisoning incident on Palm Island, Australia, which resulted in the hospitalization of 148 people. We have screened 13 C. raciborskii isolates from various regions of Australia and shown that both toxic and nontoxic strains exist within this species. No association was observed between geographical origin and toxin production. Polyketide synthases (PKSs) and peptide synthetases (PSs) are enzymes involved in secondary metabolite biosynthesis in cyanobacteria. Putative PKS and PS genes from C. raciborskii strains AWT205 and CYP020B were identified by PCR using degenerate primers based on conserved regions within each gene. Examination of the strain‐specific distribution of the PKS and PS genes in C. raciborskii isolates demonstrated a direct link between the presence of these two genes and the ability to produce cylindrospermopsin. Interestingly, the possession of these two genes was also linked. They were also identified in an Anabaena bergii isolate that was demonstrated to produce cylindrospermopsin. Taken together, these data suggest a likely role for these determinants in secondary metabolite and toxin production by C. raciborskii. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 413–421, 2001
Synchrotron x‐ray fluorescence and secondary ion mass spectrometry in tree ring microanalysis: applications to dendroanalysis
Authors: Martin R. R. , Sham T. K. , Wong Won G , Jones K. W. , Feng H. 
Published: August 2002

AbstractMining operations in the Sudbury district of northern Ontario have resulted in environmental damage caused by acid rain and heavy metal pollution. Remedial liming (Ca/MgCO3) has been used in an attempt to restore the pH of the lake water and soil to natural levels. The spatial and temporal variation of metal concentrations in the annual growth rings of trees may be a useful indicator of the effects of the pollutants and the liming operation. We used synchrotron radiation‐induced x‐ray emission (SRIXE) and secondary ion mass spectrometry (SIMS) to examine the distribution of selected metals in the annual growth rings of red pine (Pinus resinosa) from an area damaged by acid rain and heavy metal pollution which had been subjected to remedial liming (Ca/MgCO3). The results show a non‐uniform distribution of metals in the stemwood, including seasonal variations and changes in the Ca/Mn ratio consistent with the increased soil pH following liming. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation of energy‐dispersive x‐ray spectra of low‐Z elements from electron‐probe microanalysis of individual particles
Authors: Osán J. , de Hoog J. , Van Espen P. , Szalóki I. , Ro C.‐U. , Van Grieken R. 
Published: August 2002

AbstractSeveral applications require the determination of low‐Z elements such as C, N and O in individual microparticles. Electron‐probe microanalysis (EPMA) using a thin‐window energy‐dispersive x‐ray detector offers the possibility to detect light elements. To achieve at least semi‐quantitative information on the chemical composition of each individual particle, accurate determination of x‐ray intensities is critical. The energy‐dispersive x‐ray spectra under 1 keV are complex. The L and M lines of heavier elements can strongly overlap with light‐element K lines. Also, the transmission of the detector window and the shape of the bremsstrahlung background should be taken into account. Because of the strong overlap of the characteristic lines, the ‘top‐hat’ filter used for on‐line evaluation of conventional computer‐controlled EPMA spectra cannot be applied for thin‐window EPMA spectra under 1 keV. Therefore, the spectra were processed using a non‐linear least‐squares fitting algorithm (AXIL). The applicability and the limitations of the method were tested by a series of measurements of particulate standards in the size range of 0.3–10 µm, made from analytical‐reagent grade chemicals. The composition and thickness of the thin window of the detector were modelled using the transmission data given by the manufacturer. The elemental composition of each individual particle was approximated using a new data evaluation method (EP‐PROC) based on an iterative Monte Carlo simulation with combination of successive approximation. The dependence of the K/L intensity ratios of the elements Ca–Zn on the size and composition of the particles was studied extensively by Monte Carlo simulations and measurements of standard particles. By taking into account the L‐line contributions of K, Ca, Ti or Cr in the spectral evaluation, the estimation of the light‐element concentrations was improved significantly, especially when K, Ca, Ti or Cr were present at high concentrations. Copyright © 2001 John Wiley & Sons, Ltd.
Quality control of commercial tea by x‐ray fluorescence
Authors: Salvador Marcos J. , Lopes Guido N. , Nascimento Filho Virgílio F. , Zucchi Orghêda L. A. D. 
Published: August 2002

AbstractBased on the energy‐dispersive x‐ray fluorescence (EDXRF) technique, the concentrations of elements (22 ≤ Z ≤ 30) were assessed in five kinds of commercial tea from six commercial suppliers: Matricaria chamomilla L. (camomile), Mentha piperita L. (mint), Cymbopogon citratus (DC) Stapf. (herb ‘cidreira’), Malus domestica Borkh. (apple tea) and Camellia sinensis (L.) O. Kuntze (black tea). The samples were excited by an x‐ray tube with an Mo anode (25 kV and 10 mA), with a Zr filter, and the characteristic x‐ray were detected by an Si(Li) detector coupled to a multichannel analyzer. Using standard samples, the relationship between the detection limit and the atomic numbers of Fe, Co, Ni, Cu and Zn was determined. In some tea samples Ti was detected, but it is not an essential microelement for the plant growth. Fe, Ni and Cu were detected in all tea samples analyzed; Ti, Cr, Co and Zn were detected in Matricaria chamomilla and Malus domestica; Ti, Co and Zn in Mentha piperita and Ti, Mn, Co and Zn in Cymbopogon citratus. The inorganic constitution profile of this matrix type and the fingerprints in the production process can be evaluated by employing the EDXRF quality control of the commercial products. Copyright © 2002 John Wiley & Sons, Ltd.
Characterization of porous microstructure by x‐ray microtomography
Authors: Appoloni Carlos R. , Macedo Álvaro , Fernandes Celso P. , Philippi Paulo C. 
Published: August 2002

AbstractKnowledge of the porous structure of amorphous material is of fundamental importance in calculating geometric parameters such as total porosity, pore size distribution and physical parameters related to fluid flow inside void space. This work involved the measurement of microstructural parameters of petroleum reservoir rocks and porous ceramic filters. Microtomographic measurements of samples were performed by employing an x‐ray tube. Bremsstrahlung radiation was filtered in transmission mode with an Sn filter at 58.5 and 28.3 keV. The beam width was about 80 µm at the sample position center. Images were analyzed in two ways. In the first method, transepts of the images were analyzed in order to calculate the total porosity by means of the average particle and media linear attenuation coefficients. In the second method, images were studied using image analysis software, named Imago, allowing the calculation of total porosity and pore size distribution. The total measured porosity of the filter C90 was 73.8, 71.1, 74.4 and 71.5% using the Archimedes method, simple gamma‐ray transmission, transept and image analysis of the microtomography at 28.3 keV, respectively. Measured total porosity for one of the sandstones was 23.23, 24.70, 23.43, 29.68, 29.65 and 27.80% using Hg and gas porosimetry, the Archimedes method, simple gamma‐ray transmission and transept analysis of the microtomography at 58.5 and 28.2 keV, respectively. Copyright © 2002 John Wiley & Sons, Ltd.
CaALK8, an alkane assimilating cytochrome P450, confers multidrug resistance when expressed in a hypersensitive strain of Candida albicans
Authors: Lata Panwar Sneh , Krishnamurthy Shankarling , Gupta Vinita , Alarco Anne‐Marie , Raymond Martine , Sanglard Dominique , Prasad Rajendra 
Published: August 2002

AbstractWe report the isolation of a novel C. albicans gene designated CaALK8, by its ability to complement drug hypersensitivity of a pdr5 (ABC: ATP‐binding cassette drug extrusion pump) null mutant of S. cerevisiae (JG436). CaALK8 in JG436 conferred resistance to drugs such as cycloheximide (CYH), fluconazole (FCZ), O‐phenanthroline (PHE) and 4‐nitroquinoline oxide (NQO). The gene was so designated because its sequence was identical to a partial sequence entry named as ALK8 in the Candida database (http://alces.med.umn.edu/candida.html). CaALK8 encodes for a putative 515 amino acid protein highly homologous to alkane‐inducible cytochromes P450 (CYP52 gene family) of C. maltosa and C. tropicalis. The ability of CaALK8 to confer drug resistance was also established by its expression in another drug‐hypersensitive strain of S. cerevisiae (AD 1234568), which was deleted in seven ABC efflux pumps. The homozygous disruption of CaALK8 in a wild‐type C. albicans strain (CAI4) did not result in altered drug susceptibilities. The overexpression of CaALK8 in CAI4 resulted in only FCZ resistance. However, a distinct MDR phenotype was evident when CaALK8 was overexpressed in a drug‐hypersensitive C. albicans strain disrupted in both CDR1 and CDR2 (ABC drug extrusion pumps of C. albicans). Alk8p, similar to other Alk proteins from C. maltosa and C. tropicalis, could hydroxylate alkanes and fatty acids. In this study we demonstrate that several drugs could compete with the hydroxylation activity by directly interacting with CaAlk8p. Taken together, our results suggest that a member of the CYP52 gene family could mediate MDR in C. albicans, although it does not seem to be involved in the development of azole resistance in clinical isolates. The nucleotide sequence reported in this paper has been submitted to GenBank under Accession No. Y14766. Copyright © 2001 John Wiley & Sons, Ltd.
Hormonal and behavioral relationships during estrus in the giant panda
Authors: Lindburg D.G. , Czekala N.M. , Swaisgood R.R. 
Published: August 2002

AbstractNonlactating female giant pandas experience a single estrus during the spring mating season. Although both hormonal and behavioral aspects of estrus have been reported on captive females, little is known about the relationship between them. Data were collected on a single captive female during three successive seasons, revealing a high degree of regularity in both estrogen profiles and the temporal pattern of associated behaviors. The birth of a live cub in the last of the three seasons, using artificial insemination, confirmed the time of ovulation as occurring shortly after a peak in urinary estrogen values. In this study, we examined the occurrence of female scent marking, rear presentations, chirp and bleat vocalizations, and the tail‐up display, and plotted their occurrence relative to the underlying estrogen values. We conclude that the role of estrogen in the expression of these behaviors is neither simple nor directly causal. Temporal associations indicate that a triggering rather than a maintenance function for estrogen is implicated. This analysis provides a clear identification of estrous behaviors, but in both the time and form of occurrence these behaviors most likely vary between females and seasons. Zoo Biol 20:537–543, 2001. © 2002 Wiley‐Liss, Inc.
Automatic Verification of a Lip-Synchronisation Protocol Using Uppaal
Authors: Bowman H. , Faconti G. , Katoen J.-P. , Latella D. , Massink M. 
Published: August 2002

Abstract.
We present the formal specification and verification of a lip-synchronisation protocol using the real-time model checker Uppaal. A number of specifications of this protocol can be found in the literature, but this is the first automatic verification. We take a published specification of the protocol, code it up in the Uppaal timed automata notation and then verify whether the protocol satisfies the key properties of jitter and skew. The verification reveals some aws in the protocol. In particular, it shows that for certain sound and video streams the protocol can time-lock before reaching a prescribed error state. We also discuss our experience with Uppaal, with particular reference to modelling timeouts and to deadlock analysis.
History of Clinical Transplantation
Authors: Starzl Thomas E. 
Published: August 2002

Abstract.The emergence of transplantation has seen the development of increasingly potent immunosuppressive agents, progressively better methods of tissue and organ preservation, refinements in histocompatibility matching, and numerous innovations in surgical techniques. Such efforts in combination ultimately made it possible to successfully engraft all of the organs and bone marrow cells in humans. At a more fundamental level, however, the transplantation enterprise hinged on two seminal turning points. The first was the recognition by Billingham, Brent, and Medawar in 1953 that it was possible to induce chimerism‐associated neonatal tolerance deliberately. This discovery escalated over the next 15 years to the first successful bone marrow transplantations in humans in 1968. The second turning point was the demonstration during the early 1960s that canine and human organ allografts could self‐induce tolerance with the aid of immunosuppression. By the end of 1962, however, it had been incorrectly concluded that turning points one and two involved different immune mechanisms. The error was not corrected until well into the 1990s. In this historical account, the vast literature that sprang up during the intervening 30 years has been summarized. Although admirably documenting empiric progress in clinical transplantation, its failure to explain organ allograft acceptance predestined organ recipients to lifetime immunosuppression and precluded fundamental changes in the treatment policies. After it was discovered in 1992 that long‐surviving organ transplant recipients had persistent microchimerism, it was possible to see the mechanistic commonality of organ and bone marrow transplantation. A clarifying central principle of immunology could then be synthesized with which to guide efforts to induce tolerance systematically to human tissues and perhaps ultimately to xenografts.
Longmire Lecture: My 50 Years at the University of California, Los Angeles
Authors: Terasaki Paul I. 
Published: August 2002

Abstract.The main concept driving my work has been the humoral theory of immunity to allografts. It led to the development of the microlymphocytotoxicity test, which is used to look for the relevant transplant antigens using alloantisera. Using alloantibodies produced by pregnancies, the HLA system was defined through a series of international histocompatibility workshops. It was then shown that the HLA system was important for matching donors and recipients for bone marrow transplants and organ transplants. More than 6000 HLA‐matched kidney transplants from cadaver donors have now been shared in the United States. HLA antigens were found to be of importance in anthropologic and disease susceptibility studies. Currently HLA antibodies are being studied intensively to determine their role in chronic rejection. If it is proven that these antibodies trigger intimal proliferation, occluding arterioles, HLA antibodies will become essential to the monitoring of chronic rejection.
Short Bowel Syndrome
Authors: Wilmore Douglas W. , Robinson Malcolm K. 
Published: August 2002

AbstractThe short bowel syndrome is a symptom complex that occurs in adults who have less than 200 cm of jejunum‐ileum remaining after intestinal resection. Similar symptoms are observed in infants and children following massive bowel resection or congenital anomalies and in individuals with longer segments of intestine with severe mucosal disease. Initial care should focus on a thorough excision of nonviable bowel, an exact measurement of the remaining viable bowel, placing all intestine in continuity at the initial or subsequent operation, and controlling initial food intake. With time, adaptation of the remnant intestine occurs, and absorptive function may be maximized by enhancing the enteral diet and minimizing parenteral nutrition. Growth factors and specialized nutrients may also enhance this process. Intestinal transplantation should be considered in selected individuals with the short bowel syndrome who fail intestinal rehabilitation protocols.
Preoperative Localization of Parathyroid Adenoma in Patients with Concomitant Thyroid Nodular Disease
Authors: Krausz Yodphat , Lebensart Pinchas D. , Klein Martin , Weininger Jolie , Blachar Arye , Chisin Roland , Shiloni Eitan 
Published: August 2002

AbstractWe have previously demonstrated the role of high‐resolution ultrasonography (US) in preoperative localization of parathyroid adenoma in patients with primary hyperparathyroidism (PHPT) and no thyroid abnormalities. The present study prospectively evaluated the possible additional value of 99mTc‐sestamibi (MIBI) in patients with PHPT and concomitant multinodular thyroid disease (MND). Patients with PHPT underwent US and MIBI scintigraphy prior to neck exploration. Imaging data were correlated with the site and pathology of the parathyroid tissue removed and were analyzed separately for patients with MND and those with a normal thyroid gland. Among 77 patients with a solitary parathyroid adenoma at surgery, 40 had concomitant MND, whereas 37 patients had no morphologic changes in the thyroid gland, on US or at surgery. Prior to surgery, MIBI scintigraphy depicted 58 of the 77 adenomas (75%) and US localized 51 (66%); the combined sensitivity was 87% (67/77). Among the 37 patients with no thyroid nodules, MIBI located 29 (78%) and US identified 30 (81%) of the adenomas; the combined sensitivity was 89%. In the 40 patients with MND, MIBI identified 29 adenomas (73%) and US localized only 53% (21/40); the combined sensitivity was 85%. Overall, the positive predictive value (PPV) of MIBI for detecting a solitary parathyroid adenoma was 94%, for US it was 88%, and with the two tests combined it was 97%. In patients with no thyroid abnormalities, the PPV of MIBI and US was 97%, but it decreased to 91% and 78%, respectively, in patients with MND. Two patients with false‐positive findings on both MIBI and US had associated thyroid disease. Hence MIBI scintigraphy contributes to localization of a solitary parathyroid adenoma mainly in patients with concomitant MND. The combined MIBI and US modalities result in sparing these patients bilateral neck exploration.
Peritoneal Echinococcosis
Authors: Karavias Dionissios D. , Vagianos Constantine E. , Kakkos Stavros K. , Panagopoulos Constantine M. , Androulakis John A. 
Published: August 2002

AbstractPeritoneal echinococcosis is rare, even in areas where hydatid disease is endemic. Although the liver and lungs are the organs most commonly involved, peritoneal echinococcosis, either primary or secondary, represents an uncommon but significant manifestation of the disease. We reviewed the medical records of 121 patients with abdominal echinococcosis operated on in our department over the past 12 years. Peritoneal echinococcosis was found in 17 patients, usually combined with liver disease. The presenting symptoms were mostly atypical, and a few cases were discovered accidentally during routine follow‐up after operations for hepatic echinococcosis. Surgery remains the best curative or palliative treatment for peritoneal echinococcosis, although anthelmintics can be an effective alternative for the treatment of small and asymptomatic cysts.
De Novo Hepatitis B and C Viral Infection after Liver Transplantation
Authors: Cavallari Antonino , De Raffele Emilio , Bellusci Roberto , Miniero Rita , Vivarelli Marco , Galli Silvia , Luchetti Rita , Fruet Fiorenza , Giordano Emanuele , Mazziotti Alighiero , Conte Roberto , Sprovieri Giuseppe 
Published: August 2002

AbstractHepatitis B (HBV) and hepatitis C (HCV) viral infections often recur after orthotopic liver transplantation (OLT), but viral infections acquired with OLT have not been widely investigated. The aim of the study was to evaluate the incidence, evolution, and diagnostic problems of de novo HBV and HCV infections in liver transplant recipients with long‐term follow‐up. Altogether 121 transplant recipients entered the study. HBV, HDV, and HCV infections were diagnosed by means of serology and the polymerase chain reaction (PCR). Three patients became hepatitis B surface antigen (HBsAg)‐positive after OLT, all of whom showed signs of persistent viral replication. Twelve patients became anti‐HCV‐positive after OLT: After clearance of passive antibodies, active anti‐HCV seroconversion was usually delayed. The viral genome was detected in 9 of 12 patients, with fluctuations of viremia during their follow‐up. The other three patients, who were HBsAg‐positive before and after OLT, were repeatedly HCV‐RNA‐negative despite persistent anti‐HCV reactivity. Four pre‐OLT HBsAg‐positive patients had evidence of HBV‐related liver transplant disease. The remaining 8 of 12 patients experienced repeated alanine aminotransferase increases more than two times normal after transplant. De novo infections due to primary hepatotropic viruses were frequent after OLT in our experience. Early diagnosis of infection, especially when the HCV is involved, may be problematic and should be taken into account in patients showing persistent aminotransferase abnormalities. Monitoring viral markers and accurate evaluation of biopsy specimens are mandatory. The interference between HBV and HCV might play a role in the replicative cycle of one or both viruses in co‐infected patients.