bluuebunny/crossref_metadata_2025_split huggingface dataset:
In‐situ product removal to enhance the yield of biocatalytic reactions with competing equilibria: α‐glucosidase catalysed synthesis of disaccharides
Authors: Ahmed Farjad , Stein Andreas , Lye Gary J 
Published: August 2002

AbstractTransglycosylations are an important class of enzyme‐catalysed reaction that occur in most living organisms and which are finding increasing application for the synthesis of therapeutic compounds. Compared with other bioconversion processes, however, they generally suffer from low product yields. This is due to the fact that in aqueous environments water is able to undergo a nucleophilic attack of the enzyme–substrate complex, increasing the rate of the competing hydrolysis reaction. The equilibrium yield of such reactions is consequently only around 10% (w/w). Here, the potential of applying in‐situ product removal (ISPR), with the boronate‐containing affinity resin Affi‐Gel® 601, to the α‐glucosidase mediated conversion of phenyl α‐D‐glucoside to phenyl α‐maltoside has been examined. ISPR can increase the product yield from such kinetically‐controlled reactions by removing the product from the bulk aqueous phase as soon as it is formed. In this way the competing hydrolysis reaction can be prevented and conversions potentially driven to completion. Initial experiments revealed that the optimum pH of the α‐glucosidase reaction in water–acetonitrile mixtures was between 5.5 and 6.5, whereas the optimum pH for binding of the product to the Affi‐Gel® 601 resin was between 8.0 and 8.5. Despite having to compromise on both the optimal conditions for glucosidation and for binding, an increase in product yield of 25% (w/w) was still possible following the implementation of ISPR at pH 8 in an aqueous medium containing 50% (v/v) acetonitrile. Similar results were found with the β‐galactosidase catalysed synthesis of phenyl α‐galactobiose, indicating the potentially generic nature of the ISPR methodology. While these initial results are promising, they indicate the need for more highly selective resins for carbohydrate adsorption (with higher capacities) if further increases in product yield are to be obtained.© 2001 Society of Chemical Industry
Sonographic detection of secondary MALT lymphoma of the submandibular gland
Authors: Matsushita Tsuyoshi , Takashima Shodayu , Takayama Fumiyoshi , Momose Mitsuhiro , Wang Jichen , Ishiyama Tetsuya 
Published: August 2002

AbstractThis report describes a case of mucosa‐associated lymphoid tissue (MALT) lymphoma of the lacrimal glands that recurred in the submandibular salivary glands. Gray‐scale sonography showed small hypoechoic nodules, measuring less than 0.5 cm in diameter, in both submandibular glands. The echogenicity and echotexture of the rest of the submandibular glands and of the parotid glands was normal. Power Doppler sonography revealed increased vascularity within the nodules. A sonographically guided aspiration biopsy of the nodules revealed MALT lymphoma. Secondary MALT lymphoma should be considered in the presence of multiple small hypoechoic nodules in the salivary glands in patients with a history of MALT lymphoma at another location. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:462–465, 2001.
Contrast‐Enhanced endosonography for the diagnosis of anal and anovaginal fistulas
Authors: Sudoł‐Szopińska Iwona , Jakubowski Wiesław , Szczepkowski Marek 
Published: August 2002

AbstractPurposeWe assessed whether contrast‐enhanced anal endosonography (AES) with hydrogen peroxide improves the identification of anal fistulas and their internal openings compared with non‐contrast AES.MethodsThe study group comprised 12 patients who had various types of anal fistulas with visible external openings. AES was performed before and about 15 seconds after injection of 1 ml of 3% hydrogen peroxide into the fistula tract through the external opening.ResultsBoth contrast and non‐contrast AES revealed 7 transsphincteric, 2 intersphincteric, 1 suprasphincteric, and 2 anovaginal fistulas. Simple tracts were found in 8 cases and complex tracts in 4 cases on non‐contrast AES. Contrast‐enhanced AES revealed 9 simple and 3 complex fistulas. One fistula that appeared complex on the non‐contrast study appeared simple after contrast agent administration. Contrast‐enhanced AES demonstrated more internal openings than non‐contrast AES did. Surgery confirmed 11 of the fistulas; an internal opening could not be located surgically for the other tract.ConclusionsContrast‐enhanced AES appears to be superior to non‐contrast AES in the preoperative assessment of anal and anovaginal fistulas and in demonstrating and locating their internal openings. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:145–150, 2002; DOI 10.1002/jcu.10042
Cytochemical study of Streptococcus agalactiae and macrophage interaction
Authors: Teixeira Cristina Ferreira , Azevedo Neide Lemos , Carvalho Técia Maria Ulisses , Fuentes Jemima , Nagao Prescilla Emy 
Published: August 2002

AbstractLight and electron microscopy were used to analyse the process of interaction of Streptococcus agalactiae (serotypes Ia, III, and V) with resident and activated mouse peritoneal macrophages. Transmission electron microscopy showed that adherence of the S. agalactiae serotype Ia, but not III and V serotypes, to the surface of activated macrophages triggers the respiratory oxidative burst as revealed by the presence of reduced nicotinamide adenine dinucleotide (phosphate) [NAD(P)H]‐oxidase in the phagocytic vacuoles. Fusion of macrophage lysosomes with bacteria‐containing phagocytic vacuoles was observed in macrophages treated with Lucifer yellow as well as by localization of acid phosphatase for all serotypes. Microsc. Res. Tech. 54:254–259, 2001. © 2001 Wiley‐Liss, Inc.
Energy and water conservation in frozen vs. supercooled larvae of the goldenrod gall fly, Eurosta solidaginis (fitch) (Diptera: Tephritidae)
Authors: Irwin Jason T. , Lee Richard E. 
Published: August 2002

AbstractInsects that tolerate severe cold during winter may either supercool or tolerate ice forming within the tissues of the body. To compare the relative advantages of freezing and supercooling, we measured rates of CO2 production and water loss in frozen and supercooled goldenrod gall fly larvae (Eurosta solidaginis). As an important first step, we measured the time required for ice content and metabolic rate to stabilize upon freezing. Ice content stabilized after only three hours of freezing at –5°C, whereas CO2 production required 12 hours to stabilize. Subsequent experiments found that freezing greatly reduced both water loss and metabolic rate. Comparisons of supercooled and frozen larvae at –5°C indicated that CO2 production fell 47% with freezing and water loss decreased 35%. As temperature decreased to –10 and –15°C, CO2 production fell exponentially and was no longer detectable at –20°C with our measurement system. Our results demonstrate that freezing significantly reduces energy consumption during the winter and may therefore improve winter survival and spring fecundity. The advantages of freezing over supercooling would drive selection toward insect freeze tolerance and also toward higher supercooling points to increase the duration of freezing each winter. J. Exp. Zool. 292:345–350, 2002. © 2002 Wiley‐Liss, Inc.
Utilisation of nutrients by embryos of the enigmatic Australian viviparous skink Niveoscincus coventryi
Authors: Thompson Michael B. , Stewart James R. , Speake Brian K. , Russell Kylie J. , McCartney Ruth J. 
Published: August 2002

AbstractThe Eugongylus species group of Australian lygosomine skinks provides an unparalleled opportunity to study the evolution of placentotrophy. Viviparity and placentotrophy have evolved in two lineages, currently recognised as the genera Pseudemoia and Niveoscincus. The genus Niveoscincus is important because it is the only lineage of squamates in which variation in placental morphology and in the pattern of embryonic nutrition is known. Niveoscincus coventryi has the least complex placental morphology among species currently assigned to the genus. We quantified the net uptake of nutrients across the placenta of N. coventryi for comparison with other species in the genus and with other viviparous and oviparous lizards. The pattern of embryonic nutrition of N. coventryi is similar to other viviparous lizards with simple placentae in that there is no net uptake of dry matter during development but there is a net uptake of water, calcium, potassium, and sodium. There is no net uptake of lipid, nitrogen (an index of protein), or magnesium. We conclude that N. coventryi is predominantly lecithotrophic. Further, if N. coventryi is the sister taxon to Tasmanian Niveoscincus, then the distribution of patterns of embryonic nutrition among members of this clade suggests that the evolution of placentotrophy occurred during radiation of this lineage in Tasmania. J. Exp. Zool. 290:291–298, 2001. © 2001 Wiley‐Liss, Inc.
Circuits through prescribed vertices in k‐connected k‐regular graphs
Authors: Häggkvist Roland , Mader Wolfgang 
Published: August 2002

AbstractWe show that every set of $k+\lfloor{1\over 3}\sqrt{k}\rfloor$ vertices in a k‐connected k‐regular graph belongs to some circuit. © 2002 John Wiley & Sons, Inc. J Graph Theory 39: 145–163, 2002
Domination in planar graphs with small diameter*
Authors: Goddard Wayne , Henning Michael A. 
Published: August 2002

AbstractMacGillivray and Seyffarth (J Graph Theory 22 (1996), 213–229) proved that planar graphs of diameter two have domination number at most three and planar graphs of diameter three have domination number at most ten. They also give examples of planar graphs of diameter four having arbitrarily large domination numbers. In this paper we improve on their results. We prove that there is in fact a unique planar graph of diameter two with domination number three, and all other planar graphs of diameter two have domination number at most two. We also prove that every planar graph of diameter three and of radius two has domination number at most six. We then show that every sufficiently large planar graph of diameter three has domination number at most seven. Analogous results for other surfaces are discussed. © 2002 Wiley Periodicals, Inc. J Graph Theory 40: 1–25, 2002
Small odd cycles in 4‐chromatic graphs*
Authors: Jiang Tao 
Published: August 2002

AbstractIt is shown that every 4‐chromatic graph on n vertices contains an odd cycle of length less than $2\sqrt {n}\,+3$. This improves the previous bound given by Nilli [J Graph Theory 3 (1999), 145–147]. © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 115–117, 2001
On the Thomassen's conjecture*
Authors: Li Jianping 
Published: August 2002

AbstractC. Thomassen proposed a conjecture: Let G be a k‐connected graph with the stability number α ≥ k, then G has a cycle C containing k independent vertices and all their neighbors. In this paper, we will obtain the following result: Let G be a k‐connected graph with stability number α = k + 3 and C any longest cycle of G, then C contains k independent vertices and all their neighbors. This solves Thomassen's conjecture for the case α = k + 3. © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 168–180, 2001
Synthesis of 11C‐labelled acamprosate for PET studies
Authors: Courtyn Jan , Goethals Patrick , Eycken Johan Van der , Dams Richard 
Published: August 2002

AbstractA method for labelling acamprosate (calcium N‐acetyl homotaurinate), an anti‐craving compound for ethanol, with 11C, has been developed for in vivo studies with positron emission tomography (PET). The synthesis was based on the acylation of homotaurinate using [11C]acetyl chloride as the labelling agent. Reversed‐phase HPLC in highly aqueous mobile phase conditions was used for product purification. The radiochemical yield achieved was about 1.14 GBq (31 mCi) with a specific radioactivity of 8.14 GBq/µmol (220 mCi/µmol). For the identification of 11C‐radioactivity and determination of specific radioactivities, HPLC and 1H‐NMR were used. Copyright © 2001 John Wiley & Sons, Ltd.
Arterial wall MRI characteristics are associated with elevated serum markers of inflammation in humans
Authors: Weiss Clifford R. , Arai Andrew E. , Bui Minh N. , Agyeman Kwabena O. , Waclawiw Myron A. , Balaban Robert S. , Cannon Richard O. 
Published: August 2002

AbstractInflammation contributes to atherosclerosis, but assessment in humans is largely restricted to measurement of markers in blood. We determined whether MRI properties of large arteries were associated with markers of inflammation in serum. Double inversion recovery, fast spin‐echo images of the common carotid arteries and infrarenal aorta were obtained at 1.5 T both before and after gadolinium‐DTPA (0.1 mmol/kg) in 52 subjects ≥40 years of age, 17 of whom had no risk factors for atherosclerosis and thus served as controls. Twenty‐two study participants had increases in wall thickness (14), T2‐weighted signal intensity (11), and/or contrast enhancement values (7) that were >2 standard deviations (SDs) from control group mean values. Ten subjects in this group had evidence of focal plaques in the carotids (5) and/or aorta (6). Compared with the remaining 30 subjects, these 22 had significantly higher levels of interleukin‐6 (3.53 ± 2.46 vs. 1.97 ± 1.37 pg/mL, P = 0.004), C‐reactive protein (0.56 ± 0.98 vs. 0.30 ± 0.52 mg/dL, P = 0.019), vascular cell adhesion molecule‐1 (572 ± 153 vs. 471 ± 130 ng/mL, P = 0.012), and intercellular adhesion molecule‐1 (244 ± 80 vs. 202 ± 45 ng/mL, P = 0.015), and nonsignificant differences in levels of E‐selectin (46.1 ± 18.9 vs. 42.3 ± 11.3 ng/mL, P = 0.369). Thus, MRI characteristics of the aorta and carotid arteries were associated with elevated serum markers of inflammation, frequently in the absence of definite atheroma. MRI of large arteries may provide a new approach to investigate the contribution of inflammation to atherogenesis. J. Magn. Reson. Imaging 2001;14:698–704. © 2001 Wiley‐Liss, Inc.
Electron ionization‐induced fragmentation of 3‐cyclopropanospiro and 3‐cyclobutanospiro derivatives of Benzo‐ and pyridosultams
Authors: Danikiewicz Witold , Wojciechowski Krzysztof , Kosiński Szymon , Olejnik Marian 
Published: August 2002

AbstractElectron ionization‐induced fragmentations of 3‐cyclopropanospiro and 3‐cyclobutanospiro derivatives of selected benzo‐ and pyridosultams were studied and compared with the thermal decomposition of these compounds. 3‐Cyclopropanospirobenzosultams and the corresponding pyridosultams were found to be thermally stable up to 400 °C. At higher temperatures they eliminate an SO2 molecule yielding several dimethylindole derivatives together with other isomeric compounds. Loss of SO2 is also the main fragmentation process of the molecular ions of these compounds with the exception of the 4‐NO2 derivative, for which elimination of CH2O is observed. 3‐Cyclobutanospirobenzosultams and ‐pyridosultams eliminate SO2 on heating above 200 °C, yielding the corresponding 2‐aryl‐1,3‐butadienes. Under EI conditions expulsion of SO2 from the molecular ions is also observed. However, elimination of C2H4 is the dominant process except for the 5‐OCH3 derivative. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of molecular mass distribution of silicone oils by supercritical fluid chromatography, matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry and their off‐line combination
Authors: Chmelík Josef , Planeta Josef , Řehulka Pavel , Chmelík Josef 
Published: August 2002

AbstractAn Erratum has been published for this article in Journal of Mass Spectrometry 37(3) 2002; 343.Silicone oil samples were characterized by supercritical fluid chromatography (SFC), matrix‐assisted laser desorption ionization–time‐of‐flight mass spectrometry (MALDI–TOF MS), and their off‐line combination. SFC was used to separate samples of silicone oils on micropacked capillary columns. The fractions for the identification studies were obtained from SFC runs at defined time intervals, when the restrictor was pulled out from the chromatographic flame ionization detector (FID) and inserted into a glass vial with acetone. MALDI–TOF MS was used for the identification of individual oligomers in the fractions separated. The molecular mass distributions determined based on SFC and MALDI–TOF MS measurements were compared. From this comparison, it follows that the results are in good agreement. However, certain differences were observed: MALDI–TOF MS was capable of detecting somewhat larger oligomers than the SFC‐FID, but the lower molecular mass oligomers were not present in the MALDI spectra. Differences in the region of lower molecular masses can be explained by evaporation of the more volatile low molecular mass oligomers resulting from heating of the sample during the MALDI–TOF MS measurements as a result of the absorption of the laser shot energy. The fact that no high mass discrimination effects of the MALDI–TOF MS measurements, compared with SFC, were observed is very promising for further applications of MALDI–TOF MS in characterizing synthetic polymers of moderate polydispersity. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of regioselectivity in ring opening of tert‐butylaziridinones by a combination of 15N labeling and electrospray ionization‐ion trap mass spectrometry
Authors: Talaty E. R. , Van Stipdonk M. J. , Hague M. J. , Provenzano F. A. , Boese C. A. 
Published: August 2002

AbstractThe ring opening of 1,3‐di‐tert‐butylaziridinone by tert‐butylamine and aniline was investigated by using electrospray ionization and collision‐induced dissociation in an ion trap mass spectrometer in conjunction with 15N labeling of the two amine nucleophiles. Using the MSn capabilities of the ion trap instrument, we were able to monitor the retention of the 15N label through successive fragmentation steps. Both amines exhibited a remarkable degree of selectivity in that they both cleaved exclusively the 1,3‐bond (the alkyl–nitrogen bond). This result is in contrast to that obtained previously with methylamine, which cleaved just the opposite bond, namely, the 1,2‐bond (the acyl–nitrogen bond). These contrasting results could not have been predicted by previously published guidelines. Copyright © 2001 John Wiley & Sons, Ltd.
Differentiation of betamethasone and dexamethasone using liquid chromatography/positive electrospray tandem mass spectrometry and multivariate statistical analysis
Authors: Antignac Jean‐Philippe , Le Bizec Bruno , Monteau Fabrice , Andre François 
Published: August 2002

AbstractBetamethasone and dexamethasone are two corticosteroids differing in the stereoisomery of their C‐16 methyl group. These two compounds are imperfectly separated by reversed‐phase liquid chromatography and their mass spectra are very similar, leading to a difficult unambiguous identification according to European criteria. A method is proposed for differentiating betamethasone and dexamethasone using liquid chromatography/tandem mass spectrometry and multivariate statistical analysis. Multiple analysis of variance was used for the justification and the selection of diagnostic ions. Principal component analysis permitted the suitability of the approach to be tested on a large number of samples. Discriminant factorial analysis was finally performed to build a decisional model based on the six most significant ions. This novel utilization of mass spectrometric data appeared efficient for the unambiguous identification of the target analytes in urine samples. Copyright © 2001 John Wiley & Sons, Ltd.
Continuous flow isotope ratio mass spectrometry for the measurement of nanomole amounts of 13CO2 by a reverse isotope dilution method
Authors: Guitton J. , Grand F. , Magat L. , Désage M. , Francina A. 
Published: August 2002

AbstractA simple method for the determination of nanomole amounts of 13CO2 generated from an in vitro reaction is reported. The incubation medium contains a known amount of unlabeled sodium bicarbonate and the gaseous 13CO2 enriches the atmosphere upon which a measurement of the isotopic enrichment (13CO2/12CO2) is made corresponding to a reverse isotope dilution. The quantification of the 13CO2 was performed by gas chromatography/isotope ratio mass spectrometry. This assay was validated in terms of linearity, accuracy and precision using three different substrates which produce 13CO2 either by enzymatic reaction [13C]urea, sodium [13C]formate) or by chemical reaction (sodium [13C]bicarbonate). Four calibration curves were tested for each 13C‐labeled substrate, allowing the quantification of 13CO2 from 25 pmol to 150 nmol. The dynamics of the assay were obtained as a function of the quantity of unlabeled sodium bicarbonate added to each sample. Copyright © 2001 John Wiley & Sons, Ltd.
Multicenter randomized study comparing initial daily induction with high dose lymphoblastoid interferon vs. standard interferon treatment for chronic hepatitis c
Authors: Diago Moisés , Suárez Dolores , García‐Villarreal Luis , Castro Angeles , Domínguez Agustín , Pardo Margarita , del Olmo Juan A. , Pérez‐Hernández Francisco , Aguilar José , Quiroga Juan Antonio , Carreño Vicente 
Published: August 2002

AbstractOne hundred fifty‐five chronic hepatitis C patients were assigned at random to receive natural lymphoblastoid interferon (IFN)α‐n1, s.c., for 13 months in one of three treatment regimens: initial daily induction with 10 million units (MU) followed (group 1, n = 50) or not (group 2, n = 52) by 1 month of rest and then three times weekly 10 MU (2 months), 5 MU (2 months), and 3 MU (8 months); group 3 (n = 53) received tiw 5 MU (2 months) followed by 3 MU (11 months). By intention‐to‐treat analysis, ALT normalization at completion of treatment was greater in patients who received continuous IFNα‐n1 therapy with initial daily induction (group 2: 24/52, 46%) compared with those given intermittent therapy with initial daily induction (group 1: 17/50, 34%) and those who received standard IFNα‐n1 therapy (group 3, 18/53, 34%; P not significant). The sustained ALT response was 26%, 27% and 21% and the sustained virological response was 20%, 27%, and 19%, in groups 1, 2, and 3, respectively. A trend was observed towards a higher biochemical and virological end‐of‐treatment response in patients given induction therapy (17%) compared with standard therapy (6%, P  =  0.053). Sustained biochemical and virological responses were 20%, 27%, and 17% in groups 1, 2, and 3, respectively. Platelet and leukocyte counts decreased following daily high‐dose treatment and remained low until therapy cessation (P < 0.001). The data suggest that daily s.c. induction with 10 MU IFNα‐n1 followed by intermittent or continuous maintenance therapy for 1 year does not improve the results achieved with the standard 1‐year IFNα course in the treatment of chronic hepatitis C patients. J. Med. Virol. 64:460–465, 2001. © 2001 Wiley‐Liss, Inc.