bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of [13C6]‐ϵ‐caprolactam and [13C6]‐hexamethyleneimine
Authors: Ellames George J. , Herbert John M. 
Published: September 2002

AbstractAn efficient route is described for the preparation of [13C6]‐ϵ‐caprolactam (1b), and thence to [13C6]‐hexamethyleneimine (2b) hydrochloride. The sequence, from [13C6]‐phenol, uses a rhodium‐catalysed hydrogenation to generate labelled cyclohexanol, and thence cyclohexanone, whose oxime was subjected to a Beckmann rearrangement to give 1a. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of tritium labelled delta sleep‐inducing peptide
Authors: Giraud Matthieu , Morgat Jean‐Louis , Cavelier Florine , Martinez Jean 
Published: September 2002

AbstractThe α,β‐dehydro precursor of the delta sleep‐inducing peptide (DSIP) for tritiation was prepared prior to tritiation using a 3+6 fragment coupling strategy on a solid support. The first fragment, α,β‐dehydrotripeptide, was prepared in solution in five steps in 79% overall yield while the second fragment was obtained by a step by step peptide synthesis on a Wang resin using an Fmoc strategy. The α,β‐dehydrotripeptide was coupled to the fragment linked to the resin, followed by a deprotection/cleavage step to yield the α,β‐dehydro‐DSIP, 7. Catalytic reduction of unsaturated DSIP using tritium gas and palladium oxide as catalyst gave [3H]DSIP having a specific activity of 1.184 TBq/mmol(32 Ci/mmol). Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of the [3H] labelled potent and selective peripheral benzodiazepine receptor ligand CB 34
Authors: Latrofa A. , Trapani G. , Franco M. , Harris M.J. , Serra M. , Biggio G. , Liso G. 
Published: September 2002

AbstractThe synthesis of the [3H] labelled peripheral benzodiazepine receptor (PBR) ligand CB 34, useful for binding assay, tissue distribution studies, and elucidation of the physiological role of PBR, is described. Catalytic reduction with 3H2 gas and 10% Pd/C catalyst of the key intermediate 2 afforded the product at a specific activity of 111 Ci/mmol. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis and deuterium labeling of some 4‐phenyl, 3‐substituted isochromanes
Authors: Guyard Anne‐Laure , Valleix Alain , Rousseau Bernard , Cintrat Jean‐Christophe 
Published: September 2002

AbstractThe preparation of a number of 4‐phenyl isochromanes as well as the deuterated analogs is described using a simple strategy starting from easily obtained acetals. The diasteresoselectivity and the enantioselectivity of the adopted approach are both good. The deuterated analogs are prepared using tributyltin deuteride or triethyl deuterosilane. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of 4‐dihydroxyboryl‐2‐[18F]fluorophenylalanine with relatively high‐specific activity
Authors: Vähätalo Jyrki K. , Eskola Olli , Bergman Jörgen , Forsback Sarita , Lehikoinen Pertti , Jääskeläinen Juha , Solin Olof 
Published: September 2002

AbstractAn alternative procedure to produce 4‐dihydroxyboryl‐2‐[18F]fluorophenylalanine ([18F]FBPA) for positron emission tomography studies in boron neutron capture therapy is described. Relatively high‐specific activity electrophilic radiofluorine is produced using a post‐target conversion of [18F]F– to [18F]F2. Liquid chromatography with mass spectrometric detection is used to estimate the specific radioactivity of [18F]FBPA and to verify the quality control for chemical identity of the target compound. [18F]FBPA produced according to this method fulfilled the pharmaceutical quality requirements for an injection in patients. Copyright © 2002 John Wiley & Sons, Ltd.
Reactions of actinide ions with ethylene oxide
Authors: Gibson John K. 
Published: September 2002

AbstractNaked and oxo‐ligated actinide (An) monopositive ions were reacted with ethylene oxide, cyclo‐C2H4O (EtO). Along with An = U, Np, Pu and Am, ions of two lanthanide (Ln) elements, Ln = Tb and Tm, were studied for comparison. Metal and metal oxide ions, M+, MO+ and MO2+, were generated by laser ablation and immediately reacted with EtO. Unreacted and product ions were detected by time‐of‐flight mass spectrometry. It was apparent that the overall reaction cross‐sections decreased in the order U+ ≥ Np+ > Pu+ > Am+. A primary reaction channel for each studied metal was the formation of MO+ from M+, in accord with the expected exothermicity of oxygen abstraction from EtO. For U, Np and Pu, the dioxides were also major products, indicating OAn+—O dissociation energies of at least 350 kJ mol−1, the energy required for O‐atom abstraction from EtO. For Am, Tb and Tm, the dioxides were only very minor products, reflecting the stabilities of the trivalent states and resistance to oxidation to higher valence states; the structures/bonding in these MO2+ are intriguing given that the formal pentavalent bonding state is effectively unattainable. It was demonstrated that EtO, unlike more thermochemically favorable but kinetically restricted O‐donors, is effective at achieving facile oxidation of actinide metal ions to the monoxide, and to the dioxide if the second O‐abstraction reaction is exothermic. Several intriguing minor products were also identified, most of which incorporate metal–oxygen bonding and are attributed to the oxophilicity of the f‐block elements; the contrast to the behavior of first‐row d‐block transition elements is striking in this regard. Particularly noteworthy was the formation of MH4+ (and MOH4+), evidently via abstraction of all four H atoms from a single C2H4O molecule; the structures/bonding in these novel ‘hydride’ species are indeterminate and warrant further attention. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of the electron affinities of α‐ and β‐naphthyl radicals using the kinetic method with full entropy analysis. The C — H bond dissociation energies of naphthalene
Authors: Lardin Harvey A. , Squires Robert R. , Wenthold Paul G. 
Published: September 2002

AbstractThe C — H bond dissociation energies for naphthalene were determined using a negative ion thermochemical cycle involving the gas‐phase acidity (ΔHacid) and electron affinity (EA) for both the α‐ and β‐positions. The gas‐phase acidity of the naphthalene α‐ and β‐positions and the EAs of the α‐ and β‐naphthyl radicals were measured in the gas phase in a flowing afterglow–triple quadrupole apparatus. A variation of the Cooks kinetic method was used to measure the EAs of the naphthyl radicals by collision‐induced dissociation of the corresponding α‐ and β‐naphthylsulfinate adducts formed by reactions in the flow tube portion of the instrument. Calibration references included both π and σ radicals, and full entropy analysis was performed over a series of calibration curves measured at collision energies ranging from 3.5 to 8 eV (center‐of‐mass). The measured EAs are 33.0 ± 1.4 and 31.4 ± 1.0 kcal mol−1 (1 kcal = 4.184 kJ) for the α‐ and β‐naphthyl radicals, respectively. The gas‐phase acidities for naphthalene were measured by the DePuy silane cleavage method, which utilizes the relative abundances of aryldimethylsiloxides and trimethylsiloxide that result from competitive cleavages from a proposed pentacoordinate hydroxysiliconate intermediate. The measured acidities are 394.0 ± 5.0 and 397.6 ± 4.8 kcal mol−1 for the α‐ and β‐ positions, respectively. The C — H bond dissociation energies calculated from the thermochemical cycle are 113.4 ± 5.2 and 115.4 ± 4.9 kcal mol−1 for the α‐ and β‐positions, respectively. These energies are, to within experimental error, indistinguishable and are approximately the same as the first bond dissociation energy for benzene. Copyright © 2001 John Wiley & Sons, Ltd.
Detection of water‐soluble vitamins by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry using porphyrin matrices
Authors: Chen Yi‐Ting , Ling Yong‐Chien 
Published: September 2002

AbstractThe detection of water‐soluble vitamins B1, B2, B6, B12 and C by matrix‐assisted laser desorption/ionization (MALDI) time‐of‐flight mass spectrometry (TOFMS) was attempted by studying 17 porphyrin matrices. Comparative studies of porphyrin matrices, useful mass spectral window, matrix/analyte molar ratio (M/A), ultraviolet–visible absorption characteristics and quantitative results were made. Most porphyrin matrices provide a useful mass spectral window in the low‐mass range. The optimal M/A increases with increasing molecular mass of the vitamin. Vitamin B12 possesses the highest molecular mass and requires a higher M/A. The presence of hydroxyl or carboxyl groups in the porphyrin is an indicator of a useful MALDI matrix. Vitamins B2 and B6 were readily ionized upon irradiation with a 337 nm laser without the use of any porphyrin matrix. Improved linearity and sensitivity of the calibration curves were obtained with samples prepared with a constant M/A. The limits of detection and quantitation are at the picomole level. The results indicate that MALDI‐TOFMS with porphyrin matrices is a rapid and viable technique for the detection of low molecular mass water‐soluble vitamins. Copyright © 2002 John Wiley & Sons, Ltd.
Mass spectrometry of cis‐diamminedichloroplatinum(II) adducts with the dinucleosidemonophosphates d(ApG), d(GpG) and d(TpC) in an ion trap
Authors: Hagemeister Timo , Linscheid Michael 
Published: September 2002

AbstractThe detection and fragmentation behaviour of adducts of the chemotherapeutic cis‐diamminedichloroplatinum(II) (cisplatin) with the dinucleosidemonophosphates d(ApG), d(GpG) and d(TpC) as model compounds for DNA adducts in an ion trap with electrospray ionization were studied. Mainly the monofunctional adduct, the bifunctional adduct and the bifunctional adduct with platinum bridging two dinucleosidemonophosphates were detected. In addition, several more complex adducts were seen resulting from reactions among these species. Adduct formation was low in the case of d(TpC). Fragmentation could be controlled strongly by varying the temperature of the transfer capillary; furthermore, tandem mass spectrometric (MS/MS) experiments on both the monofunctional and the bifunctional adducts were performed. For the adducts of d(ApG) and d(GpG) losses of NH3 and HCl were the most dominant reactions, followed by the losses of one, then another two units of 98 amu from the sugar–phosphate backbone, whereas d(TpC)–Pt predominantly forms the dinucleosidemonophosphate. In the gas phase, the conversion of the monofunctional into the bifunctional adducts through binding to another site in the dinucleotide accompanied by loss of NH3 or HCl could also be observed. The removal of a ligand from the coordination sphere of the square‐planar platinum complexes appeared to be the crucial step for the induction of further fragmentation of the dinucleotide ligand. MSn experiments of the bifunctional adducts of d(ApG) and d(GpG) revealed different fragmentation pathways involving the loss of phosphoric acid, metaphosphoric acid, deoxyribose units (intact or dehydrated) and the nucleobases in different orders, leaving characteristic binding site‐determining fragments. Fragmentation of these ions was also performed, mainly resulting in fragmentation of the bases. The study confirmed the remarkable stability of the platinum–guanine bond compared with other nucleobases. Copyright © 2002 John Wiley & Sons, Ltd.
Hepatitis B virus genotypes in Uzbekistan and validity of two different systems for genotyping
Authors: Kato Hideaki , Ruzibakiev Ruslan , Yuldasheva Nodira , Hegay Tatyana , Kurbanov Fuat , Achundjanov Bakhodir , Tuichiev Lazis , Usuda Sadakazu , Ueda Ryuzo , Mizokami Masashi 
Published: September 2002

AbstractHepatitis B virus (HBV) has been classified into seven genotypes, designated A–G. The HBV genotype has a characteristic geographical distribution. The Republic of Uzbekistan is located in the heart of Asia and has been considered to be a region with high endemicity of hepatitis viruses. However, the present distribution of hepatitis virus infection in this region is unknown. The aim of this study was to investigate the distribution of HBV genotypes and to elucidate the validity of two genotyping systems in Uzbekistan. Fifty‐four patients with hepatitis B surface antigen were investigated. HBV genotypes were determined by two methods: one based on restriction fragment length polymorphism (RFLP) targeting to S region, and another on enzyme‐linked immunosorbent assay (ELISA), using monoclonal antibodies to pre‐S2 region. Seven (13%) and 47 (87%) of the 54 subjects were classified into genotypes A and D, respectively. Dual infection of two viral populations of the same genotype was observed in one subject. No significant difference of ALT level (203.3 ± 244.7 vs. 190.6 ± 39.5) and HBeAg (42.9% vs. 42.6%) were found between genotypes A and D. In this study, the validity of the genotyping systems in this region was confirmed. J. Med. Virol. 67:477–483, 2002. © 2002 Wiley‐Liss, Inc.
High prevalence of human herpesvirus 8 (HHV‐8) infection in south Texas children
Authors: Baillargeon Jacques , Leach Charles T. , Deng Jian‐Hong , Gao Shou‐Jiang , Jenson Hal B. 
Published: September 2002

AbstractHuman herpesvirus 8 (HHV‐8), also known as Kaposi's sarcoma‐associated herpesvirus, is etiologically associated with Kaposi's sarcoma and other rare malignancies. HHV‐8 infection is common in certain areas of Africa and Italy, but occurs in only 0–15% of populations in North America and Europe. The epidemiology and prevalence of HHV‐8 infection among children in the United States has not been determined, but is assumed to be low based on limited studies. The objective of this study was to determine the seroprevalence and possible risk factors of HHV‐8 infection in children living in south Texas. Questionnaire data were collected and HHV‐8 serologic tests were performed from a consecutive, non‐probability sample of 123 healthy children (ages 4–13 years) attending general pediatric clinics in south Texas. Serum was tested for HHV‐8 antibodies by latent immunofluorescence assay and ORF65 enzyme‐linked immunosorbent assay confirmed by immunoblot. HHV‐8 prevalence and 95 percent confidence intervals were calculated using standard epidemiologic methods. Logistic regression was used to assess independent risk factors associated with HHV‐8 seropositivity. The overall prevalence of HHV‐8 infection was 26%. No statistically significant associations were exhibited between HHV‐8 prevalence and the variables under study. The prevalence of HHV‐8 infection among children in south Texas, particularly among those under the age of 12 years, indicates that non‐sexual transmission of this virus is likely to occur among this population. Future investigations of larger study samples will be necessary to develop an understanding of specific routes and risk factors of HHV‐8 transmission among children in south Texas. J. Med. Virol. 67:542–548, 2002. © 2002 Wiley‐Liss, Inc.
Detection and characterisation of human astroviruses in children with acute gastroenteritis in Blantyre, Malawi
Authors: Cunliffe Nigel A. , Dove Winifred , Gondwe Jailosi S. , Thindwa Benson D.M. , Greensill Julie , Holmes Jennifer L. , Bresee Joseph S. , Monroe Stephan S. , Glass Roger I. , Broadhead Robin L. , Molyneux Malcolm E. , Hart C. Anthony 
Published: September 2002

AbstractIn a 2‐year hospital‐based study of paediatric gastroenteritis in Blantyre, Malawi, astroviruses were detected by enzyme immunoassay in 15 (1.9%) of 786 inpatients and in 9 (2.3%) of 400 outpatients. Greater disease severity was noted in children coinfected with human immunodeficiency virus (HIV). Six human astrovirus (HAstV) genotypes were identified, including HAstV‐1 (25%), HAstV‐2 (21%), HAstV‐3 (25%), HAstV‐4 (13%), HAstV‐5 (4%), and HAstV‐8 (13%). Although astroviruses are not major causes of gastroenteritis among children admitted to hospital in Blantyre, concomitant HIV infection appears to be a risk factor for increased severity of disease. J. Med. Virol. 67:563–566, 2002. © 2002 Wiley‐Liss, Inc.
Molecular detection and sequence analysis of human caliciviruses from acute gastroenteritis outbreaks in Hungary
Authors: Farkas T. , Berke T. , Reuter G. , Szûcs G. , Matson D.O. , Jiang X. 
Published: September 2002

AbstractThree viral gastroenteritis (VGE) outbreaks that occurred in 1998–1999, in Hungary were investigated for the presence of human caliciviruses (HuCVs). HuCVs in stool specimens were detected by reverse transcription‐polymerase chain reaction (RT‐PCR) using primer pair 289/290, which was designed based on the RNA‐dependent RNA polymerase (RdRp) sequence. RT‐PCR results were confirmed by sequencing showing that all three outbreak strains belonged to genogroup II of “Norwalk‐like viruses” (NLVs). Two strains had high sequence identity with strains in known genetic clusters (Hawaii and Lordsdale clusters). The third strain (MOH) had distinct RdRp sequence, sharing 77/86% (nt/aa) identity with Snow Mountain virus (SMV), the closest genogroup II virus. To characterize MOH further, we cloned, sequenced, and expressed in baculovirus its capsid gene. It had 75/79% (nt/aa) identity with SMV, but 97/98% (nt/aa) identity with NLV/Hillingdon/90/UK, a recently identified genetic cluster of HuCVs. The recombinant MOH (rMOH) capsid protein self‐assembled into virus‐like particles (VLPs), which is antigenically distinct from other recombinant HuCV capsid antigens available in our laboratory. Further study of this VLP will have important applications in antigenic characterization and diagnosis of HuCVs. J. Med. Virol. 67:567–573, 2002. © 2002 Wiley‐Liss, Inc.
HPV16 and HPV18 in genital tumors: Significantly different levels of viral integration and correlation to tumor invasiveness
Authors: Badaracco Gianna , Venuti Aldo , Sedati Alfonso , Marcante Maria Luisa 
Published: September 2002

AbstractThe integration of the high‐risk HPV16 and HPV18 types into the cell genome is considered an important step in malignant transformation. The relationship between the physical status of the virus and clinical/pathological parameters was studied by type‐specific and multiplex PCR for E6, E2, and E1 sequences in 86 genital tumors from different sites, consisting of 69 invasive carcinomas (including 5 microinvasive carcinomas), 9 carcinomas in situ, 6 severe dysplasias, and 2 moderate dysplasias. Forty tumors contained HPV16 (46.6%), 7 HPV18 (8.1%), and 39 both viruses (45.3%). HPV16 DNA was found either as pure integrant (35.4%), or pure episome (36.7%), or a mixture of both (27.8%). Conversely, all 46 lesions containing HPV18 showed pure integrated forms. The physical status of both types was not related to the tumor site, the tumor/node/metastasis stage, or the histological differentiation grade of the invasive carcinomas. HPV16 integration was significantly associated with invasiveness. Interestingly, in double infections when HPV16 coexisted with HPV18, its genome was found more frequently in episomal form than in single infections where, conversely, it was mostly integrated (P < 0.0001), suggesting a sort of competition for cell integration sites. The complete HPV18 integration, even in pre‐neoplastic lesions, indicates a different behavior in genital transformation compared with HPV16 and may reflect a major aggressiveness of this viral type. In conclusion, virus typing in conjunction with the evaluation of the integration status may provide a better prognostic evaluation together with an improved diagnosis. J. Med. Virol. 67:574–582, 2002. © 2002 Wiley‐Liss, Inc.
Prevalence and genotype distribution of cervical human papillomavirus infection: Comparison between pregnant women and non‐pregnant controls
Authors: Chan Paul K.S. , Chang Alexander R. , Tam Wing‐Hung , Cheung Jo L.K. , Cheng Augustine F. 
Published: September 2002

AbstractControversies exist on the effect of pregnancy on human papillomavirus (HPV) infection. A cross‐sectional section study was conducted to compare the prevalence and genotype distribution of cervical HPV infection between pregnant and non‐pregnant women in Hong Kong. Cervical samples were collected from 308 pregnant women and from the same number of age‐matched controls recruited from a cervical cancer screening center located at the same hospital. HPV was detected by the polymerase chain reaction, followed by genotype identification by restriction fragment length polymorphism and direct sequencing analyses. The prevalence of HPV for pregnant women was 10.1%, without significant variation with age, gestation, gravidity and parity. The prevalence of HPV for non‐pregnant group was 11.4% and did not show significant difference when compared to the pregnant group either by overall or age‐stratified subgroup analyses. When the analysis was stratified according to the risk‐type of HPV infection, still no significant difference between pregnant and non‐pregnant groups was observed (all types: 10.1 vs. 11.4%, P = 0.602; high‐risk types: 5.8 vs. 7.8%, P = 0.338; low‐risk types: 1.0 vs. 2.9%, P = 0.080; unknown‐risk types: 3.2% vs. 1.3%, P = 0.105). The results of this study show no evidence for an influence of pregnancy on HPV prevalence, and a majority of HPV‐infected pregnant women had normal cervical cytology. HPV positive results in pregnant women per se should be managed conservatively. J. Med. Virol. 67:583–588, 2002. © 2002 Wiley‐Liss, Inc.
Detection of measles virus RNA in whole blood stored on filter paper
Authors: Katz Russell S. , Premenko‐Lanier Mary , McChesney Michael B. , Rota Paul A. , Bellini William J. 
Published: September 2002

AbstractThe purpose of this study was to evaluate the use of dried blood spots stored on filter paper as a means to provide specimens for virologic surveillance for measles virus (MV) in situations when the reverse cold chain is not available. Two single‐step RT‐PCR assays were evaluated for sensitivity of detection of MV nucleoprotein gene RNA. The more sensitive assay was then used to assess the stability of MV RNA in dried whole blood stored on filter paper. MV RNA was found to be stable in dried blood spots for up to 2 months at room temperature or 1 month at 37°C. As few as 100 infected human peripheral blood mononuclear cells (PBMC) per blood spot could be detected using a single‐step RT‐PCR reaction and ethidium bromide detection. MV RNA was also detected in dried blood spots obtained from rhesus macaques after challenge with wild‐type MV. In the rhesus samples, the single‐step RT‐PCR reaction could detect approximately 103 TCID50 per blood spot, while nested PCR detected 3 TCID50 per blood spot. The results of this laboratory‐based study suggest that the use of dried blood spots stored on filter has the potential to improve virologic surveillance for MV in some areas, and they emphasize the need for continued testing under field conditions. J. Med. Virol. 67:596–602, 2002. © 2002 Wiley‐Liss, Inc.