bluuebunny/crossref_metadata_2025_split huggingface dataset:
LightCycler consensus PCR for rapid and differential detection of human erythrovirus B19 and V9 isolates
Authors: Schalasta Gunnar , Schmid Michael , Lachmund Tessa , Enders Gisela 
Published: March 2004

AbstractUntil recently, B19 virus was considered to be the only human pathogen of the genus erythrovirus. However, other non‐B19 virus strains, such as V9, have now been isolated and are thought to cause infections clinically and serologically indistinguishable from those caused by B19 virus. Whereas B19 virus related isolates have a low genetic diversity of only 1–2%, nucleotide disparity of up to 12% was found for the new isolates, suggesting that non‐B19 virus isolates may not be detectable using B19 virus specific PCR methods. To overcome this problem, we designed consensus primers and probes to enable the simultaneous detection of both B19 and non‐B19 virus and subsequent discrimination of the two lineages by melting temperature (Tm) analysis. A total of 196 clinical specimens, from 185 patients with a history of or an anamnesis resembling B19 virus infection, were analyzed using the consensus PCR test. Erythrovirus DNA was detected in 37 of these samples and was found to be B19 virus specific in each case, confirming previous results using B19 virus specific PCR. Although no non‐B19 virus DNA was detected in any of the clinical samples tested in this study, more extensive studies are warranted. The routine use of erythrovirus consensus PCR in the diagnosis of B19 virus infection should provide valuable information on the epidemiology and clinical role of non‐B19 virus isolates; its use in screening would increase the safety of blood products. J. Med. Virol. 73:54–59, 2004. © 2004 Wiley‐Liss, Inc.
Genotypic dominance and novel recombinations in HBV genotype B and C co‐infected intravenous drug users
Authors: Chen Bing‐Fang , Kao Jia‐Horng , Liu Chun‐Jen , Chen Ding‐Shinn , Chen Pei‐Jer 
Published: March 2004

AbstractPathogenic differences among hepatitis B virus (HBV) genotypes have been documented. However, the interaction between different HBV genotypes remains unclear. Herein, we chose HBV genotypes B (HBV/B) and C (HBV/C) co‐infected intravenous drug users to study this issue. HBV genotype was determined in 40 HBsAg, anti‐HCV, and anti‐HDV co‐positive intravenous drug users by using genotype‐specific primers. The distribution of HBV genotype was as follows: HBV genotype B alone in 29 (72.5%); HBV genotype C alone in 4 (10.0%); and mixed HBV genotype B and HBV genotype C in 7 (17.5%). The interaction between HBV genotype B and HBV genotype C within the same individual was further studied in the seven intravenous drug users with HBV genotype B and HBV genotype C co‐infection. By direct sequencing of the pre‐S region, only HBV genotype B was detected. When 10–21 clones of the pre‐S region were propagated from each intravenous drug user and sequenced, most of the clones were HBV genotype B. Novel recombinations between HBV genotype B and HBV genotype C occurred in four clones (M7‐5, M1‐10, M1‐21, and M1‐24) from two intravenous drug users (M7 and M1). The recombination breakpoints were estimated at nucleotide 3120–3171 for M7‐5, at nucleotide 3060–3191 for M1‐10, and at nucleotide 2910–2950 for M1‐21 and M1‐24 by SimPlot program. The recombination sites of these HBV/pre‐S C‐B and B‐C recombinants may be within the pre‐S1 region. The results in this study suggest that HBV/B is the dominant strain in HBV genotypes B and C co‐infected intravenous drug users in Taiwan, and recombinations between different HBV genotype are not unusual. The impact of recombination on the evolution of HBV and their clinical significance remains to be studied. J. Med. Virol. 73:13–22, 2004. © 2004 Wiley‐Liss, Inc.
Solubility, immunogenicity and physical properties of the nucleocapsid protein of Nipah virus produced in Escherichia coli
Authors: Tan Wen Siang , Ong Swee Tin , Eshaghi Majid , Foo Sze‐Shir , Yusoff Khatijah 
Published: March 2004

AbstractThe nucleocapsid (N) protein of Nipah virus (NiV) can be produced in three Escherichia coli strains [TOP10, BL21(DE3) and SG935] under the control of trc promoter. However, most of the product existed in the form of insoluble inclusion bodies. There was no improvement in the solubility of the product when this protein was placed under the control of T7 promoter. However, the solubility of the N protein was significantly improved by lowering the growth temperature of E. coli BL21(DE3) cell cultures. Solubility analysis of N‐ and C‐terminally deleted mutants revealed that the full‐length N protein has the highest solubility. The soluble N protein could be purified efficiently by sucrose gradient centrifugation and nickel affinity chromatography. Electron microscopic analysis of the purified product revealed that the N protein assembled into herringbone‐like particles of different lengths. The C‐terminal end of the N protein contains the major antigenic region when probed with antisera from humans and pigs infected naturally. J. Med. Virol. 73:105–112, 2004. © 2004 Wiley‐Liss, Inc.
African links and hepatitis B virus genotypes in the Republic of Yemen
Authors: Sallam Talal A. , William Tong C.Y. 
Published: March 2004

AbstractHepatitis B virus (HBV) genotypes in three different communities in the Republic of Yemen with and without significant African links were studied. The subjects included indigenous Yemeni blood donors (n = 987), Africans who had settled down in Yemen for several generations (n = 97) and Soqotrans living on an island in the Indian Ocean close to the African coast (n = 99). Phylogenetic analysis of HBV surface region sequences showed the presence of two major genotypes; A and D: sequences from the blood donors were all genotype D (17/17); those from Africans residing in Yemen were predominantly genotype D (7/8) although one sequence was genotype A; whereas a mixture of genotype A and D was found among the Soqotrans (5/8 and 3/8 respectively). Genotype A sequences were associated with higher viral load, but the difference was not statistically significant. Human migration and international travel, may lead to an interaction between HBV genotypes. The Republic of Yemen is at a location where genotypes A and D meet. The results from this study suggest that genotype A is found only in communities with continuing African links and that genotype D remains the dominant genotype in settled populations. More studies are needed to examine possible long‐term changes in HBV genotypes in this region. J. Med. Virol. 73:23–28, 2004. © 2004 Wiley‐Liss, Inc.
Antigenic and molecular analysis of influenza A (H3N2) virus strains isolated from a localised influenza outbreak in South Africa in 2003
Authors: Besselaar Terry G. , Botha Lizelle , McAnerney Jo M. , Schoub Barry D. 
Published: March 2004

AbstractA severe acute institutional influenza outbreak occurred in a police residential college in Pretoria amongst new recruits and staff members at the end of May 2003. The outbreak was characterised by marked illness which affected a total of 648 students, 26 of whom were admitted to hospital. Symptoms included pyrexia, severe headache, and myalgia. The attack rate per dormitory building ranged from 20 to 47%, with an overall attack rate of 34%. Throat swabs and bronchoalveolar lavage specimens were sent to the National Institute for Communicable Diseases (NICD) from 20 patients. All were positive for influenza A by multiplex PCR and/or indirect immunofluorescence, and were further identified as subtype H3N2. Additional specimens from sporadic influenza cases in Johannesburg and surrounding areas were collected through the NICD active viral surveillance programme for respiratory viral testing and were also positive for influenza A H3N2 viruses. Viruses isolated from patients from both the institutional outbreak as well as from sporadic cases were analysed both antigenically and at the molecular level to determine the characteristics of the influenza strain responsible for the epidemic. The results showed clearly that the outbreak was caused by the introduction in 2003 into South Africa of the novel A/Fujian/411/02‐like H3N2 influenza strain, which is antigenically distinct from the A/Panama/2007/99 vaccine strain. The rapid spread of these variant viruses to the southern hemisphere indicates that the H3N2 component of the influenza vaccine needs to be updated for the 2004 southern hemisphere winter. J. Med. Virol. 73:71–78, 2004. © 2004 Wiley‐Liss, Inc.
Spontaneous and stimulated Raman scattering and infrared spectra of benzil (C14H10O2) crystal: promoting modes of the stimulated effect, anharmonicity and scaling factors of fundamental vibrations
Authors: Hanuza J. , Sa̧siadek W. , Kucharska E. , Michalski J. , Ma̧czka M. , Kaminskii A. A. , Koronienko A. A. , Dunina E. B. , Klapper H. , Hulliger J. , Mohmed A. F. A. 
Published: March 2004

AbstractStimulated Raman scattering spectra of benzil (C14H10O2) crystal were measured using picosecond pumping at 300 K. Their lasing components are related to those of polarized IR and spontaneous Raman spectra of an oriented crystal. The nature and assignment of vibrational modes are discussed on the basis of quantum chemical calculations. The B3LYP and MPW1PW91 hybrid functionals that include a mixture of HF and DFT exchange correlation were applied. The results of the chemical quantum calculations were compared with those of normal coordinate analysis performed previously. The role of the anharmonic effects was analyzed and the scaling factors of the vibrational wavenumbers were determined. Copyright © 2004 John Wiley & Sons, Ltd.
Nanostructured polymer gels
Authors: Hu Zhibing 
Published: March 2004

AbstractA brief review of our recent work on polymer gel opals is given in memory of late Professor Tanaka. The central idea is to first synthesize monodisperse polymer gel nanoparticles, then self‐assemble them into a 3D network, and eventually covalently bond them. The covalent bonding contributes to the structural stability, while self‐assembly provides them with crystal structures that diffract light, resulting in colors. N‐isopropylacrylamide (NIPA) gel has been used as a model system for this study. The nanostructured NIPA gel, which contain up to 97 wt% water, displays a striking iridescence like precious opal but are soft and flexible like gelatin.
Structural and optical properties of poly(4‐vinyl pyridine)/pyridine gels
Authors: Vaganova Evgenia , Yitzchaik Shlomo 
Published: March 2004

AbstractA study of photoinduced processes in pyridine‐based gels is presented. Poly(4‐vinyl pyridine) dissolved in pyridine with water addition forms a photosensitive material. Under irradiation at the main absorption at 250 nm, a new intense absorption at 360 nm and an emission at 515 nm appeared. Upon continuation of radiation, together with an increase in the intensity of the new absorption, a prolonged tail through the whole visible range is observed. A new far red‐shifted emission arises in correlation with the absorption spectrum changes. The presence of lower energy aggregates leads to polymer morphology changes. Short‐range aggregates enhance polymer‐polymer interactions. Long range aggregates have a tendency to crystallize. The photoinduced morphology changes was studied by transmission electron microscopy (TEM) of the polymer thin film and differential scanning calorimetry (DSC) of the gel. Phase separated species, micelles‐like forms with domain size over 200 nm, and nanocrystals with average size 20‐30 nm are demonstrated.
Image analysis of the spatial distribution of paramagnetic Pr3+ ions in a polymer gel by a 1H‐chemical shift NMR imaging method
Authors: Yokota Satomi , Sasaki Akitsugu , Hotta Yoshio , Yamane Yuji , Kimura Hideaki , Kuroki Shigeki , Ando Isao 
Published: March 2004

Abstract1H‐chemical shift NMR imaging patterns of a poly(methacrylic acid) gel containing water with paramagnetic praseodymium ions(Pr3+) were successfully observed, in order to elucidate spatial distribution of Pr3+ ions in the gel. The 1H chemical shift of water associated with Pr3+ ions in the gel moves largely downfield. By analyzing these experimental results, the immersion process of Pr3+ ions into the network of the polymer gel was spatially clarified. Further, it is shown that the chemical shift NMR imaging method is a useful means for determining the spatial distribution of paramagnetic metal ions in polymer gels.
Water diffusion in methacrylate based copolymer hydrogels of 2‐hydroxyethyl methacrylate
Authors: Hill David J.T. , Chowdhury Mohammad , Ghi Phuong Y. , Moss Naomi G. , Whittaker Andrew K. 
Published: March 2004

AbstractThe diffusion of water into cylinders of polyHEMA and copolymers of HEMA with THFMA, BMA and CHMA were studied over a range of copolymer compositions. The diffusion of water into the polymers was found to follow a Fickian, or case I mechanism. The diffusion coefficients of water were determined from mass measurements and NMR imaging studies. They were found to vary from 1.7 ± 0.2 x 10−11 m2 s−1 for polyHEMA at 37°C to lower values for the copolymers. The mass of water absorbed at equilibrium relative to the mass of dry polymer varied from 52‐58 wt% for polyHEMA to lower values for the copolymers.
Ionic strength/temperature‐induced gelation of aqueous poly(N‐isopropylacrylamide‐co‐vinylimidazole) solution
Authors: Yi Jin Woo , Na Kun , Bae You Han 
Published: March 2004

AbstractA high molecular weight copolymer of N‐isopropylacrylamide (NiPAAm) and vinyl imidazole (VI) was synthesized and its phase transition behavior in aqueous solutions (5 wt%) by simultaneous changes of ionic strength and temperature was investigated. At low ionic strengths, the copolymer solution showed two phases (clear and opaque solutions), which were freely mobile, as increasing temperatures up to 65°C due to repulsion interaction of positive charges developed by basic imidazole group on the polymer aggregates. However, at the physiological condition (I=0.15, T=37°C), four distinctive phases (clear solution, opaque solution, gel and shrunken gel) were observed because of charge shielding effect by added salts. The gel state was stable and maintained from 32°C to 55°C. In particular, the phase transition from opaque solution to gel rapidly occurred by the change in ionic strength (from ∼ 0 to 0.15) at 37°C. This characteristic can be utilized as a liquid embolic agent.
Bioconjugates of smart polymers and proteins: synthesis and applications
Authors: Hoffman Allan S. , Stayton Patrick S. 
Published: March 2004

AbstractOver the past 20 years we have been deeply involved with the synthesis and applications of stimuli‐responsive polymer systems, especially polymer‐biomolecule conjugates. The work of Toyoichi Tanaka has been a constant inspiration for our work and this article is dedicated to him. This article summarizes the research that we have carried out along with many collaborators on polymer‐protein conjugates. We include conjugates prepared by random polymer conjugation to lysine amino groups, and also those prepared by site‐specific conjugation of the polymer to specific amino acid sites that are genetically‐engineered into the known amino acid sequence of the protein. We describe the preparation and properties of thermally‐sensitive, random conjugates to enzymes and several affinity recognition proteins. We have also prepared site‐specific conjugates to streptavidin. with temperature‐sensitive polymers, pH‐sensitive polymers, and light‐sensitive polymers. The preparation of these conjugates and their many fascinating applications are reviewed in this article.
Characterization of stimuli‐sensitive polymers for biomedical applications
Authors: Yoo Mi Kyong , Seok Won Kyung , Sung Yong Kiel 
Published: March 2004

AbstractStimuli‐sensitive polymers were synthesized by copolymerizing varying ratios of N‐isopropyl acrylamide(NIPAAm) and acrylic acid(AAc). The influence of polyelectrolytes on the lower critical solution temperatures(LCSTs) of these temperature/pH sensitive polymers was investigated in the pH range of 2‐12. Polyelectrolyte complexes were prepared by mixing poly(NIPAAm‐co‐AAc) as anionic polyelectrolyte with poly(allyl amine)(PAA) or poly(L‐lysine)(PLL) as cationic polyelectrolytes, respectively. Back titration was performed to determine the pKa values of PAAc in poly(NIPAAm‐co‐AAc) and to study the effect of comonomer ionization on the cloud point temperature. The effect of polyelectrolyte complex formation on the conformation of PLL was studied as a function of temperature by means of circular dichroism(CD). The swelling ratio of poly(NIPAAm‐co‐AAc) hydrogels as a function of pH at various temperature was obtained by measuring the weight of the hydrogels in buffer solutions. The LCSTs of the poly(NIPAAm‐co‐AAc) were strongly affected by pH, polyelectrolyte solutes, AAc content, and charge density. The influence of more hydrophobic PLL as a polyelectrolyte on the cloud point of PNIPAAm/water in the copolymer was stronger than that of poly(allyl amine)(PAA). Indomethacin was loaded into these hydrogels, and controlled release of this molecule from the hydrogel was determined under various temperature and pH conditions using UV/Vis spectrophotometry.
The use of hydrophobic spacers in the development of new temperature‐ and pH‐sensitive polymers
Authors: Licea‐Claveríe A. , Rogel‐Hernández E. , Salgado‐Rodríguez R. , López‐Sánchez J.A. , Castillo L.A. , Cornejo‐Bravo J.M. , Arndt K.‐F. 
Published: March 2004

AbstractThe preparation and characterization of two series of methacrylic acid derivative polymers is described. One series contains aliphatic spacers with one to ten methylene units, while the other series includes an aromatic ring with changes in the position of the acid, as spacer. Both series of polymers were obtained as methoxy‐ester protected acid polymers and as polymers containing free acid groups in different amounts. pH‐sensitive gels and temperature‐sensitive N‐isopropylacrylamide (NIPAAm) copolymers were prepared by using some of the monomeric structures described. The pH of the swelling transition of the gels changed from 3.5 up to 9.0 as a function of the spacer length and type. The lower critical solution temperature (LCST) of NIPAAm copolymers in water was lowered from 33.6°C to 6°C as a function of the co‐monomer content and type. The observed changes in the pH of the swelling transition of gels and in the LCST of NIPAAm copolymers can only be explained if hydrophobic‐hydrophobic and hydrogen‐bonding interactions are considered in connection with the specific chemical structure of the monomers used.
Novel swelling/shrinking behaviors of glucose‐binding hydrogels and their potential use in a microfluidic insulin delivery system
Authors: Siegel Ronald A. , Gu Yuandong , Baldi Antonio , Ziaie Babak 
Published: March 2004

AbstractHydrogels based on lightly crosslinked poly(methacrylamidophenylboronic acid‐co‐acylamide) swell monototically at pH 7.4 with exposure to increasing concentrations of glucose. At pH 10 these hydrogels first shrink and then reswell with increasing glucose concentration. A mechanism for these disctinct behaviors is proposed and preliminary results validating this mechanism are presented. A simple microfabricated glucose‐sensitive valve based on this hydrogel is described.
Noradrenaline levels rise significantly in rat arterial grafts at 6 hours postoperatively, and take 48 hours to come down
Authors: Penttilä Heikki , Huttunen Pirkko , Von Smitten Karl , Waris Timo , Ashammakhi Nureddin 
Published: March 2004

AbstractThe aim of this study was to investigate the rate of disappearance of noradrenaline in arterial grafts after their transplanation. Arterial grafts were harvested from AO/Ks:OC strain rats. In each rat, a graft was harvested from the femoral artery and transplanted into the common carotid artery. A contralateral unoperated femoral artery served as control. High‐performance liquid chromatography (HPLC) with electrochemical detection was used to determine the noradrenaline content in grafts and controls. Immediately after grafting, the noradrenaline content was 76% of control value, at 6 h 130% of control value, and at 48 h 4% of control value. The drop in graft noradrenaline content (from 0–48 h) was statistically significant (P = 0.005). The difference between 0‐h, 12‐h, and 24‐h groups was statistically insignificant. Compared to control specimens, grafts contained less noradrenaline after 12 h, and it disappeared almost completely from femoral arterial grafts in rats within 48 h. © 2004 Wiley‐Liss, Inc.
Concept of arteriovenous loupes in high‐risk free‐tissue transfer: history and clinical experiences
Authors: Brüner Simone , Bickert Berthold , Sauerbier Michael , Germann Günter 
Published: March 2004

AbstractThe present study describes the concepts of arteriovenous (A‐V) loupes prior to microsurgical free flap transfer in a selected high‐risk group of patients. A one‐stage concept was employed in 26 patients; 5 patients underwent two‐stage flap transfer. Seven thrombotic occlusions of the A‐V fistula or flap vessels were recorded; 6 patients underwent successful revision. Overall flap survival was 96.8% and compared favorably to reports in the literature. Defect coverage could be achieved in all but one case. It can be concluded from the data that in selected high‐risk patient groups, i.e., following radiation, compound trauma, chronic infection, or multiple comorbidities, the creation of an A‐V fistula prior to flap transfer may facilitate innovative reconstructive solutions. © 2004 Wiley‐Liss, Inc.
Versatility of rectus abdominis free flap for reconstruction of soft‐tissue defects in extremities
Authors: Xing‐Quan Zhang , Shao‐Dong Wang , Qing‐Yu Fan , Bao‐An Ma 
Published: March 2004

AbstractRectus abdominis flaps, whose blood supply is mainly provided by superior and deep inferior epigastric vessels, are suitable not only for local transfer but also as free flaps. Based on abundant anastomoses of deep inferior epigastric vessels with other vessels such as superior epigastric vessels, lower intercostal vessels, subcostal vessels, lumbar vessels, superficial epigastric vessels, and superficial and deep iliac circumflex vessels, the rectus abdominis flap may be designed as a vertical flap, transverse flap, or oblique flap. From September 1995–October 2002, 42 free rectus abdominis flaps were transferred to reconstruct a variety of soft‐tissue defects. The size of rectus abdominis flaps ranged from 6–25 cm in length and 5–12 cm in width. The overall success rate was 100% (42 of 42). The donor area was closed directly in 8–10‐cm‐wide flaps, leaving an inconspicuous scar. Larger flaps required skin grafting. After a mean 7‐month (range, 3 weeks–18 months) follow‐up, all flaps have healed uneventfully, and donor abdominal morbidity is minimal. © 2004 Wiley‐Liss, Inc.
Preoperative CT angiography for free fibula transfer
Authors: Karanas Yvonne L. , Antony Anuja , Rubin Geoffrey , Chang James 
Published: March 2004

AbstractThe role of preoperative imaging prior to free fibula flap harvest remains controversial. The standard method of preoperative imaging has been arteriography. However, arteriography is associated with known risks and potential complications to the patient. Alternatives to traditional angiography have been sought to attempt to reduce these risks. CT angiography is a noninvasive imaging modality that can accurately assess the arterial and venous circulation, while providing images equal to those of traditional angiography. CT angiography was used in 7 patients prior to free fibula flap harvest. There were no complications from the CT angiogram or the fibula harvest. We describe our use of CT angiography for vascular imaging of the lower extremity prior to free fibula harvest. © 2004 Wiley‐Liss, Inc.