bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spin densities in two‐component relativistic density functional calculations: Noncollinear versus collinear approach
Authors: Van Wüllen Christoph 
Published: August 2002

AbstractWith present day exchange‐correlation functionals, accurate results in nonrelativistic open shell density functional calculations can only be obtained if one uses functionals that do not only depend on the electron density but also on the spin density. We consider the common case where such functionals are applied in relativistic density functional calculations. In scalar‐relativistic calculations, the spin density can be defined conventionally, but if spin‐orbit coupling is taken into account, spin is no longer a good quantum number and it is not clear what the “spin density” is. In many applications, a fixed quantization axis is used to define the spin density (“collinear approach”), but one can also use the length of the local spin magnetization vector without any reference to an external axis (“noncollinear approach”). These two possibilities are compared in this work both by formal analysis and numerical experiments. It is shown that the (nonrelativistic) exchange‐correlation functional should be invariant with respect to rotations in spin space, and this only holds for the noncollinear approach. Total energies of open shell species are higher in the collinear approach because less exchange energy is assigned to a given Kohn‐Sham reference function. More importantly, the collinear approach breaks rotational symmetry, that is, in molecular calculations one may find different energies for different orientations of the molecule. Data for the first ionization potentials of Tl, Pb, element 113, and element 114, and for the orientation dependence of the total energy of I and PbF indicate that the error introduced by the collinear approximation is ∼0.1 eV for valence ionization potentials, but can be much larger if highly ionized open shell states are considered. Rotational invariance is broken by the same amount. This clearly indicates that the collinear approach should not be used, as the full treatment is easily implemented and does not introduce much more computational effort. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 779–785, 2002
Rapid screening assay of congenital adrenal hyperplasia by measuring 17α‐hydroxyprogesterone with high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry from dried blood spots
Authors: Lai Chien‐Chen , Tsai Chang‐Hai , Tsai Fuu‐Jen , Wu Jer‐Yuarn , Lin Wei‐De , Lee Cheng‐Chun 
Published: August 2002

AbstractA rapid, simple, and specific method was developed for the diagnosis of congenital adrenal hyperplasia (CAH) from dried blood spots on newborn screening cards based on high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI‐MS/MS). The usefulness of 17α‐hydroxyprogesterone (17OH‐P) determination on dried filter‐paper blood samples from patients with CAH caused by 21‐hydroxylase deficiency was evaluated. The LC/MS/MS detection of 17OH‐P was rapid, <4 min. The intra‐ and interday accuracy and precision of the method were <7%. Our procedure maintained good linearities (R2 > 0.992) and recovery rate (>83%). We used this new method to directly determine the 17OH‐P levels in dried blood specimens from abnormal children of various ages, with a detection limit of 20 ng/ml (∼240 pg), to avoid the time‐consuming derivatization steps required by the gas‐chromatography/mass spectrometry (GC/MS) method. Four dried filter‐paper blood samples of CAH patients (three girls and one boy, 1–14 years old) were all quantified in an LC/MS/MS study and revealed high 17OH‐P levels (>90 ng/ml). After treatment, all of the elevated 17OH‐P levels either decreased or disappeared. Compared with CAH patients, 17OH‐P was nearly undetectable (<20 ng/ml) in the normal infants by LC/MS/MS. This LC/MS/MS assay is not only useful for both diagnosis and monitoring of treatment of CAH in all other age groups, it also can be used as a screening test for CAH infants. In this study, we provided the first data on 17OH‐P in dried blood specimens affected with CAH using HPLC/ESI‐MS/MS. J. Clin. Lab. Anal. 16:20–25, 2002. © 2002 Wiley‐Liss, Inc.
Conceptual and ethical issues in therapy for the psychological problems of gay men, lesbians, and bisexuals
Authors: Davison Gerald C. 
Published: August 2002

AbstractReviewed here are a number of conceptual and ethical issues surrounding the study and treatment of gay men, lesbians, and bisexuals (GLB), with particular emphasis on the frequently overlooked political and ethical dimensions of what therapists choose to treat, indeed, on the goals patients themselves want to work towards. Several issues are discussed, including the relevance and irrelevance of sexual orientation and the role of therapist biases in assessment and treatment planning, the need for better understanding of how the problems of GLB patients are construed and the associated dangers of stereotyping, the challenges of coming out and the ways therapists can help patients make the decision and how to implement it, the extra effort required to be a GLB person in terms of the formation of an unconventional social and sexual identity, the trust issues that can arise when one partner in a committed relationship requests protected sex, the challenges and rewards of parents “coming out” as family members of a gay son or daughter, the social invisibility of lesbians and the deleterious effects this can have on them, social support issues for GLB youth, and the need for professionals to take a broad, institutional community psychology perspective to their study and treatment of GLB individuals. © 2001 John Wiley & Sons, Inc. J Clin Psychol/In Session 57: 695–704, 2001.
Transcriptional regulation of podocyte specification and differentiation
Authors: Quaggin Susan E. 
Published: August 2002

AbstractGlomerular visceral epithelial cells (podocytes) are highly specialized cells found in the vertebrate and invertebrate kidney and make up a major portion of the filtration barrier between blood and urinary spaces. During development, specification and differentiation of the podocyte lineage must be tightly orchestrated to produce highly specialized characteristics such as foot processes and slit diaphragms. Furthermore, podocytes are poised to direct incoming endothelial and mesangial cells during glomerular development. They express a number of growth factors that likely play a major role in these processes. Recent findings from transgenic and knockout mouse models and the identification of genes responsible for human podocyte disease have provided insight into transcriptional regulation of some of these processes. These transcription factors include Pax2, WT1 (the Wilms tumor suppressor gene), Pod1 (capsulin, epicardin), Kreisler (maf‐1), lmx1b, and mf2. Furthermore, regulatory regions from a podocyte‐restricted gene, NPHS1 (nephrin) that are required to direct podocyte‐specific expression have been identified from both human and murine genes and provide a tool to further dissect the transcriptional regulation of podocyte‐specific gene expression. This article reviews the present state of knowledge regarding transcriptional regulation of podocyte specification and differentiation. Microsc. Res. Tech. 57:208–211, 2002. © 2002 Wiley‐Liss, Inc.
Theoretical versus experimental resolution in optical microscopy
Authors: Kozubek Michal 
Published: August 2002

AbstractThe aim of this article is to compare experimental resolution under different conditions with theoretical resolution predicted using electromagnetic diffraction theory. Imaging properties of fluorescent beads of three different diameters (0.1 μm, 0.2 μm, and 0.5 μm) as well as imaging properties of four different fluorescence‐stained DNA targets (ABL gene, BCR gene, centromere 6, and centromere 17) are studied. It is shown how the dependence of the resolution on object size varies with wavelength (520 nm versus 580 nm), type of microscopy (wide‐field, confocal using Nipkow disk, confocal laser scanning) and basic image processing steps (median and gaussian filters). Furthermore, specimen influence on the resolution was studied (the influence of embedding medium, coverglass thickness, and depth below the coverglass). Both lateral and axial resolutions are presented. The results clearly show that real objects are far from being points and that experimental resolution is often much worse than the theoretical one. Although the article concentrates on fluorescence imaging using high NA objectives, similar dependence can also be expected for other optical arrangements. Microsc. Res. Tech. 53:157–166, 2001. © 2001 Wiley‐Liss, Inc.
Association of neuronal nitric oxide synthase (nNOS) with α1‐syntrophin at the sarcolemma
Authors: Miyagoe‐Suzuki Yuko , Takeda Shin'Ichi 
Published: August 2002

Abstractα1‐syntrophin is a PDZ‐containing dystrophin‐associated protein, expressed predominantly in striated muscle and brain. α1‐syntrophin null mice generated by gene targeting technique showed no overt muscular dystrophic phenotype. Though other dystrophin‐associated proteins were localized at the sarcolemma, neuronal nitric oxide synthase (nNOS) was selectively lost from the membrane fraction but remained in the cytoplasm. Thus, the α1‐syntrophin null mice are useful in the elucidation of the functional importance of nNOS targeting at the sarcolemma. In addition, the mice would facilitate identification of other signaling molecules, which are targeted to dystrophin complex via interaction with α1‐syntrophin. Microsc. Res. Tech. 55:164–170, 2001. © 2001 Wiley‐Liss, Inc.
Characterization of the Xp21–23 region in the wood lemming, a region involved in XY sex reversal
Authors: Liu Wan‐Sheng , Nordqvist Katarina , Lau Yun‐Fai Chris , Fredga Karl 
Published: August 2002

AbstractThe wood lemming (Myopus schisticolor) harbors two types of X chromosome, a normal X and a variant X, designated X*. The X* chromosome contains a mutation that causes XY sex reversal. We have previously demonstrated that the Xp21–23 region is deleted from X* and is associated with XY sex reversal. To further analyze the deleted region, we have constructed and characterized seven X chromosome‐ and region‐specific recombinant DNA libraries. Further, we have screened mouse fetal gonad cDNA libraries with the microdissected Xp21–23 DNA as a probe in an attempt to identify homologous and expressed sequences from the deletion. Fourteen positive clones were isolated, and sequence analyses showed that ten of these contained identical sequences homologous to mouse γ‐satellite sequences. One of the remaining four was perfectly homologous to the mouse gene Ccth (chaperonin containing t‐complex polypeptide 1, η subunit). Southern blot indicated that the Ccth cDNA was located on the X chromosome, not deleted from the X* but closely linked to the deletion region. Although the role of the Ccth containing region in sex determination of the wood lemming requires additional studies, the isolation of the mouse Ccth gene by the deletion Xp21–23 probe could be important since this gene is mainly expressed in testis. J. Exp. Zool. 290:551–557, 2001. © 2001 Wiley‐Liss, Inc.
Big laws, small catches: global ocean governance and the fisheries crisis
Authors: Allison Edward H. 
Published: August 2002

AbstractThe world's fisheries are perceived to be in crisis, leading to livelihood and nutritional insecurity in fishery‐dependent areas of developing countries. This paper reviews institutional responses to this crisis. Within the last decade, there has been a shift from emphasis on ‘hard laws’ regulating fisheries in sovereign‐states' territorial waters, towards governance through ‘soft’ global voluntary codes of conduct, market incentives and partnerships between fisherfolk and governments. The new governance regime inherits daunting problems and will require sustained international political commitment to succeed. Given this political will, new enabling institutions and the ecological resilience of many marine species could restore and sustain the fisheries. Copyright © 2001 John Wiley & Sons, Ltd.
Current and emerging commercial optical biosensors
Authors: Baird Cheryl L. , Myszka David G. 
Published: August 2002

AbstractThe field of commercial optical biosensors is rapidly evolving, with new systems and detection methods being developed each year. This review outlines the currently available biosensor hardware and highlights unique features of each platform. Affinity‐based biosensor technology, with its high sensitivity, wide versatility and high throughput, is playing a significant role in basic research, pharmaceutical development, and the food and environmental sciences. Likewise, the increasing popularity of biosensors is prompting manufacturers to develop new instrumentation for dedicated applications. We provide a preview of some of the emerging commercial systems that are dedicated to drug discovery, proteomics, clinical diagnostics and routine biomolecular interaction analysis. Copyright © 2001 John Wiley & Sons, Ltd.
Distamycin A affects the stability of NF‐κB p50‐DNA complexes in a sequence‐dependent manner
Authors: Speight Robert E. , Hart Darren J. , Blackburn Jonathan M. 
Published: August 2002

AbstractThe effect of two different DNA minor groove binding molecules, Hoechst 33258 and distamycin A, on the binding kinetics of NF‐κB p50 to three different specific DNA sequences was studied at various salt concentrations. Distamycin A was shown to significantly increase the dissociation rate constant of p50 from the sequences PRDII (5′‐GGGAAATTCC‐3′) and Ig‐κ B (5′‐GGGACTTTCC‐3′) but had a negligible effect on the dissociation from the palindromic target‐κB binding site (5′‐GGGAATTCCC‐3′). By comparison, the effect of Hoechst 33258 on binding of p50 to each sequence was found to be minimal. The dissociation rates for the protein–DNA complexes increased at higher potassium chloride concentrations for the PRDII and Ig‐κB binding motifs and this effect was magnified by distamycin A. In contrast, p50 bound to the palindromic target‐κB site with a much higher intrinsic affinity and exhibited a significantly reduced salt dependence of binding over the ionic strength range studied, retaining a KD of less than 10 pM at 150 mM KCl. Our results demonstrate that the DNA binding kinetics of p50 and their salt dependence is strongly sequence‐dependent and, in addition, that the binding of p50 to DNA can be influenced by the addition of minor groove‐binding drugs in a sequence‐dependent manner. Copyright © 2002 John Wiley & Sons, Ltd.
Kinetic energy release distributions in mass spectrometry
Authors: Laskin J. , Lifshitz C. 
Published: August 2002

AbstractKinetic energy releases (KERs) in unimolecular fragmentations of singly and multiply charged ions provide information concerning ion structures, reaction energetics and dynamics. This topic is reviewed covering both early and more recent developments. The subtopics discussed are as follows: (1) introduction and historical background; (2) ion dissociation and kinetic energy release: kinematics; potential energy surfaces; (3) the kinetic energy release distribution (KERD); (4) metastable peak observations: measurements on magnetic sector and time‐of‐flight instruments; energy selected results by photoelectron photoion coincidence (PEPICO); (5) extracting KERDs from metastable peak shapes; (6) ion structure determination and reaction mechanisms: singly and multiply charged ions; biomolecules and fullerenes; (7) theoretical approaches: phase space theory (PST), orbiting transition state (OTS)/PST, finite heat bath theory (FHBT) and the maximum entropy method; (8) exit channel interactions; (9) general trends: time and energy dependences; (10) thermochemistry: organometallic reactions, proton‐bound clusters, fullerenes; and (11) the efficiency of phase space sampling. Copyright © 2001 John Wiley & Sons, Ltd.
Association of tumour necrosis factor alpha and interleukin 6 levels with cytomegalovirus DNA detection and disease after renal transplantation
Authors: Tong C.Y.W. , Bakran A. , Williams H. , Cuevas L.E. , Peiris J.S.M. , Hart C.A. 
Published: August 2002

AbstractCytokines such as tumour necrosis factor alpha (TNF‐α) and interleukin 6 (IL‐6) are thought to be important in the pathogenesis of post‐transplant cytomegalovirus (CMV) disease. CMV infection increases the production of TNF‐α and IL‐6. Conversely, TNF‐α switches on the replication of CMV. To study the association of these two cytokines with CMV activity and disease, TNF‐α and IL‐6 levels were assayed in plasma samples taken serially from three groups of renal transplant recipients. Group A (n = 12) had CMV disease and syndrome; Group B (n = 11) had detectable CMV DNA in plasma or peripheral blood leucocytes without disease, i.e., presumed asymptomatic CMV infection, and Group C (n = 11) had no detectable CMV DNA nor disease. The median peak TNF‐α levels in patients with CMV disease (Group A) were significantly higher than that in Group B or Group C (P < 0.02) whereas the median peak IL‐6 levels in group C patients were significantly lower than that in group A (P < 0.04) or group B (P < 0.03). A TNF‐α level of above 100 pg/ml was significantly associated with CMV disease and high plasma CMV load (> 10,000 copies/ml). IL‐6 levels above 15 pg/ml were significantly associated with CMV DNA detection, but not with CMV disease or elevated CMV load. High levels of TNF‐α or IL‐6 were not associated with CMV donor/recipient serostatus, HHV‐6 or HHV‐7 DNA detection, immunosuppressive regimen or rejection episodes. The role of TNF‐α in the pathogenesis of CMV disease deserves further investigation. J. Med. Virol. 64:29–34, 2001. © 2001 Wiley‐Liss, Inc.
TT virus (TTV) loads associated with different peripheral blood cell types and evidence for TTV replication in activated mononuclear cells
Authors: Maggi Fabrizio , Fornai Claudia , Zaccaro Lucia , Morrica Antonietta , Vatteroni Maria Linda , Isola Patrizia , Marchi Santino , Ricchiuti Angelo , Pistello Mauro , Bendinelli Mauro 
Published: August 2002

AbstractTT virus (TTV) loads associated with the peripheral blood cells of seven patients known to carry the virus in plasma were investigated by real‐time PCR. Whereas red cells/platelets were uniformly negative, six and four patients yielded positive peripheral blood mononuclear cells (PBMCs) and polymorphonuclear leukocytes, respectively, but viral titres were generally low. Fractionation of PBMCs into monocyte‐ and B, T4, and T8 lymphocyte‐enriched subpopulations showed no pattern in the viral loads that might suggest the preferential association of TTV to one or more specific cell types. TTV‐negative PBMCs absorbed measurable amounts of virus when incubated with infected plasma at 4°C. Furthermore, cultures of TTV‐negative phytohaemagglutinin‐stimulated PBMCs exposed in vitro to virus‐positive plasma and faecal extracts released considerable levels of infectious TTV into the supernatant fluid and the same was true for TTV‐positive stimulated PBMCs. These results indicate that, whereas freshly harvested resting PBMCs seem to produce little, if any TTV, stimulated PBMCs actively replicate the virus. J. Med. Virol. 64:190–194, 2001. © 2001 Wiley‐Liss, Inc.
Characterization of hepatitis A virus isolates from subgenotypes IA and IB in Rio de Janeiro, Brazil*
Authors: de Paula Vanessa S. , Baptista Marcia L. , Lampe Elisabeth , Niel Christian , Gaspar Ana M.C. 
Published: August 2002

AbstractHepatitis A virus (HAV) isolates from around the world have been classified into seven genotypes (I–VII). Most human strains belong to genotype I, which has been divided into two subgenotypes, A and B. South America has provided a small number of strains studied at the genome level. In the present study, IgM anti‐HAV antibodies were detected in 116 out of 250 (46%) serum samples collected from consecutive patients with acute hepatitis referred to the Brazilian Reference Center for Viral Hepatitis, Rio de Janeiro. Viral RNA were extracted from all 250 samples and submitted to a reverse transcription‐polymerase chain reaction (RT‐PCR) assay designed to amplify a genome segment in the VP1/2A junction region. HAV RNA was detected in 54/116 (47%) and 17/134 (13%) IgM anti‐HAV‐positive and ‐negative sera, respectively. In addition, HAV RNA was detected in 17/35 (49%) IgM anti‐HAV‐positive sera that had been collected at a day care center where cases of acute hepatitis were being observed for 3 months. Nucleotide sequences (168 bp) of PCR products were determined for 30 HAV isolates. Phylogenetic analysis showed that 21 belonged to subgenotype IB, while 9 were of subgenotype IA. Interestingly, a concomitant circulation of isolates from subgenotypes IA and IB was observed in the day care center. J. Med. Virol. 66:22–27, 2002. © 2002 Wiley‐Liss, Inc.
Frequent detection of the replicative form of TT virus DNA in peripheral blood mononuclear cells and bone marrow cells in cancer patients
Authors: Zhong Sheng , Yeo Winnie , Tang Mandy , Liu Cuiling , Lin Xiao‐rong , Ho Wing M. , Hui Pun , Johnson Philip J. 
Published: August 2002

AbstractThe TT virus (TTV), a member of a family of human viruses related to the circoviridae viruses, was associated initially with acute and chronic liver diseases. TTV consists of a single‐stranded, circular DNA genome of 3.8 kilobases (kb) and at least three open reading frames (ORFs). The objective of the present study was to determine whether or not TTV replicated in peripheral blood mononuclear cells (PBMCs) and bone marrow cells (BMCs). DNA was extracted from the PBMCs or BMCs of 153 cancer patients and from the PBMCs of 50 healthy blood donors (the controls). By using a single round of polymerase chain reaction (PCR), TTV was detected in 98.6% (141 of 143) of the PBMCs and in 90% (9 of 10) of the BMCs from cancer patients. TTV DNA was detected in significantly fewer control subjects at 86% (43 of 50; P < 0.05). Strand‐specific PCR (SSPCR) targeting the ORF2 of the common genotypes of TTV was developed specifically to detect TTV positive or negative strand DNA and to examine TTV replication. TTV positive strand DNA, which may be an intermediate of viral replication, was detected in 55.3% (78 of 141) of the TTV‐infected PBMCs of the cancer patients and in 7% (3 of 43) of the controls (P < 0.001). The replicative form of TTV was also detectable in 55.6% (5 of 9) of the TTV‐infected BMCs. The existence of double‐strand (positive and negative strands) TTV DNA in PBMCs and BMCs of the cancer patients was also supported by the finding that TTV DNA extracted from these cells was resistant to S1 nuclease. Using in situ hybridization, TTV DNA was also demonstrated to be present in the nucleus of PBMCs. It is concluded that replicative intermediate forms of TTV DNA are present in both PBMCs and BMCs, indicating that blood cells may be a site of TTV replication. J. Med. Virol. 66:428‐434, 2002. © 2002 Wiley‐Liss, Inc.