Showing papers by "University of Duisburg-Essen published in 2000"

Non-equilibrium critical phenomena and phase transitions into absorbing states

Abstract: This review addresses recent developments in non-equilibrium statistical physics. Focusing on phase transitions from fluctuating phases into absorbing states, the universality class of directed percolation is investigated in detail. The survey gives a general introduction to various lattice models of directed percolation and studies their scaling properties, field-theoretic aspects, numerical techniques, as well as possible experimental realizations. In addition, several examples of absorbing-state transitions which do not belong to the directed percolation universality class will be discussed. As a closely related technique, we investigate the concept of damage spreading. It is shown that this technique is ambiguous to some extent, making it impossible to define chaotic and regular phases in stochastic non-equilibrium systems. Finally, we discuss various classes of depinning transitions in models for interface growth which are related to phase transitions into absorbing states.

Mechanisms of DNA double-strand break repair and their potential to induce chromosomal aberrations.

Abstract: DNA double-strand breaks (DSB) are considered to be critical primary lesions in the formation of chromosomal aberrations. DSB may be induced by exogenous agents, such as ionizing radiation, but also occur spontaneously during cellular processes at quite significant frequencies. To repair this potentially lethal damage, eukaryotic cells have evolved a variety of repair pathways related to homologous and illegitimate recombination, also called non-homologous DNA end joining, which may induce small scale mutations and chromosomal aberrations. In this paper we review the major cellular sources of spontaneous DSB and the different homologous and illegitimate recombination repair pathways, with particular focus on their potential to induce chromosomal aberrations.

Different Mutations in the LMNA Gene Cause Autosomal Dominant and Autosomal Recessive Emery-Dreifuss Muscular Dystrophy

Abstract: Emery-Dreifuss muscular dystrophy (EMD) is a condition characterized by the clinical triad of early-onset contractures, progressive weakness in humeroperoneal muscles, and cardiomyopathy with conduction block. The disease was described for the first time as an X-linked muscular dystrophy, but autosomal dominant and autosomal recessive forms were reported. The genes for X-linked EMD and autosomal dominant EMD (AD-EMD) were identified. We report here that heterozygote mutations in LMNA, the gene for AD-EMD, may cause diverse phenotypes ranging from typical EMD to no phenotypic effect. Our results show that LMNA mutations are also responsible for the recessive form of the disease. Our results give further support to the notion that different genetic forms of EMD have a common pathophysiological background. The distribution of the mutations in AD-EMD patients (in the tail and in the 2A rod domain) suggests that unique interactions between lamin A/C and other nuclear components exist that have an important role in cardiac and skeletal muscle function.

Mutations in a new gene, encoding a zinc-finger protein, cause tricho-rhino-phalangeal syndrome type I.

Abstract: Mutations in a new gene, encoding a zinc-finger protein, cause tricho-rhino-phalangeal syndrome type I

α-Adrenergic Coronary Vasoconstriction and Myocardial Ischemia in Humans

Abstract: —The use of quantitative coronary angiography, combined with Doppler and PET, has recently been directed at the study of α-adrenergic coronary vasomotion in humans. Confirming prior animal experiments, there is no evidence of α-adrenergic coronary constrictor tone at rest. Again confirming prior experiments, responses to α-adrenoceptor activation are augmented in the presence of coronary endothelial dysfunction and atherosclerosis, involving both α1- and α2-adrenoceptors in epicardial conduit arteries and microvessels. Such augmented α-adrenergic coronary constriction is observed during exercise and coronary interventions, and it is powerful enough to induce myocardial ischemia and limit myocardial function. Recent studies indicate a genetic determination of α2-adrenergic coronary constriction.

Haematopoietic stem cell transplantation for patients with myelo- dysplastic syndromes and secondary acute myeloid leukaemias: a report on behalf of the Chronic Leukaemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT)

Abstract: Allogeneic stem cell transplantation from an HLA-identical sibling donor is a curative treatment option for a young patient with myelodysplastic syndrome, limited by age and lack of sibling donors. Alternative stem cell sources have been used more recently, such as unrelated donors, non-identical family members or autologous transplants. This analysis of 1378 transplants reported to the European Group for Blood and Marrow Transplantation (EBMT) addresses the outcome of the varying procedures according to the known risk factors. The estimated disease-free survival (DFS) and estimated relapse risk at 3 years were both 36% for 885 patients transplanted with stem cells from matched siblings. In the multivariate analysis, age and stage of disease had independent prognostic significance for DFS, survival and treatment-related mortality. Patients transplanted at an early stage of disease had a significantly lower risk of relapse than patients transplanted at more advanced stages. The estimated DFS at 3 years was 25% for the 198 patients with voluntary unrelated donors, 28% for the 91 patients with alternative family donors and 33% for the 126 patients autografted in first complete remission. The non-relapse mortality was 58% for patients with unrelated donors, 66% for patients with non-identical family donors and 25% for autografted patients. The relapse rate of 18% was relatively low for patients with non-identical family donors, 41% for patients with unrelated donors and 55% for patients treated with autologous stem cell transplantation. Both allogeneic and autologous stem cell transplantation have emerged as treatment options for patients with myelodysplastic syndromes. Transplantation with an HLA-identical sibling donor is the preferred treatment option. Patients without an HLA-identical sibling donor may be treated with either autologous stem cell transplantation or an alternative donor transplantation. Patients younger than 20 years may be treated with an unrelated donor transplantation. Patients older than 40 years, and probably also patients between 20 and 40 years, may benefit most from an autologous stem cell transplantation.

Colonic masses: detection with MR colonography.

Abstract: PURPOSE: To assess magnetic resonance (MR) colonography as a method for detection of colorectal masses, with conventional colonoscopy as the reference standard. MATERIALS AND METHODS: MR colonography was performed in 132 patients referred for colonoscopy because of the possible presence of a mass. After rectal filling with a gadopentetate dimeglumine and water enema, T1-weighted three-dimensional gradient-echo MR studies were acquired with the patient in the prone and supine positions. Water-sensitive single-shot fast spin-echo MR images were also obtained. Surface-rendered virtual endoscopic endoluminal views, orthogonal sections in three planes, and water-sensitive MR images were interactively assessed for presence of colorectal masses by two radiologists. RESULTS: MR colonography was well tolerated without sedation or analgesia. MR image quality was sufficient for diagnosis in 127 (96%) patients. Most small (≤5-mm-diameter) masses were overlooked at MR colonography, but 19 of 31 6–10-mm lesions and 26 ...

The melting point alternation in a,w-alkanediols and a,w-alkanediamines: interplay between hydrogen bonding and hydrophobic interactions.

Abstract: The structural details of a,w-alkanediols and a,w-alkanediamines which are characterized by H bonding and hydrophobic interactions. These systems represent a balance between structural simplicity and interaction complexity, which makes the study of interference between interactions a feasible exercise. The anal. of the crystal structures of diols and diamines revealed the interplay between 2 important intermol. interactions that are possible in these amphiphilic compds., namely, H bonding and hydrophobic interactions. While H bonding and hydrophobic interactions operate in consonance in even members, and therefore culminate in dense packing, they run into geometrical conflicts in odd members, leading to looser packing. Accordingly, the odd members of the diol and diamine series have relatively lower densities and m.ps. than the even members.

Quantum approach to coupling classical and quantum dynamics

Abstract: We present a consistent framework of coupled classical and quantum dynamics. Our result allows us to overcome severe limitations of previous phenomenological approaches, such as evolutions that do not preserve the positivity of quantum states or that allow one to activate quantum nonlocality for superluminal signaling. A ‘‘hybrid’’ quantum-classical density is introduced, and its evolution equation derived. The implications and applications of our result are numerous: it incorporates the back-reaction of quantum on classical variables, and it resolves fundamental problems encountered in standard mean-field theories, and remarkably, also in the quantum measurement process; i.e., the most controversial example of quantum-classical interaction is consistently described within our approach, leading to a theory of dynamical collapse. Opinions vary about the coexistence of and interaction between classical and quantum systems. In orthodox quantum theory, classical macrosystems and quantized microsystems coexist; their interaction is described asymmetrically. The influence of macrovariables upon microsystems is precisely taken into account as external forces. The backreaction of quantized microsystems upon classical macrosystems is largely ignored, except for detector variables which are typically sensitive to certain microvariables. The theory of this specific back-reaction, called measurement theory@1#, predicts the statistics of the final states after the interaction. However, the interpretation of quantized dynamics is exclusively based on this nondynamical model of back-reaction ~cf. collapse of the quantum state!; without it we could not test the validity of quantized dynamics at all. Possibly, quantization extends to macrosystems, indeed the criteria of being macroscopic or microscopic are loosely if ever defined. Contrary to quantized microvariables, quantized macrovariables may have significant back-reactions on generic classical macrovariables as well. This becomes apparent in the widely used mean-field approximation@2# which, however, has several fundamental drawbacks @3#, as we shall recall in this paper. The measurement theory also describes back-reaction, but only for idealized detectors. In some attempts to define quantum gravity, matter and some fields are quantized, while other fields ~gravity in particular! are treated as classical, thus requiring a definite hybrid—i.e., a coupled classical and quantum—dynamics. Thus a general model of the backreaction is desirable. Such a theory would describe the ‘‘collapse’’ of the wave function dynamically @4#, would replace mean-field approximations in a systematic way @5‐7#, and could have deep implications for quantum cosmology. The first conceptual attempts @4‐6# were followed by ups and downs @8#, until severe limitations were clarified @9#. In this paper we use a straightforward transformation of the problem which automatically leads to a consistent model of hybrid dynamics.

Regional brain metabolism during alcohol intoxication.

Abstract: Background: Ethanol has a broad range of actions on many neurotransmitter systems. The depressant actions of ethanol in the brain are related in part to facilitation of γ-aminobutyric acid (GABA) neurotransmission via its interaction with the benzodiazepine/GABA receptor complex. The purpose of this study was to evaluate the effects of ethanol on regional brain metabolism in 10 healthy right-handed men. The results were compared with those we previously published in a different group of 16 normal male subjects who received intravenous lorazepam, a benzodiazepine drug that also enhances GABA neutrotranmission. Methods: The subjects were scanned with positron emission tomography and [F-18] fluorodeoxyglucose twice: 40 min after the end of placebo (diet soda) or ethanol (0.75 g/kg) oral administration. Image data sets were analyzed by using both the region of interest and the statistical parametric mapping (SPM) approach. SPM was used to generate a difference image between baseline and ethanol, which we compared to the difference image between baseline and lorazepam (30 μg/kg). Results: Ethanol significantly increased self-reports of high (p≤ 0.0001), dizziness (p≤ 0.004), and intoxication (p≤ 0.0001). Ethanol significantly decreased whole brain (-25 ±6%,p≤ 0.0001) and regional metabolism. Normalization of the regional measures by whole brain metabolism (relative measures) showed that ethanol decreased relative metabolic activity in occipital cortex (-4.9 ± 4.1%, p ≤ 0.006), whereas it increased relative metabolic act in left temporal cortex (+3.5 ± 2.9%, p≤ 0.006) and left basal ganglia (+9 ± 6.3%, p≤ 0.0009). SPM analyses revealed the same pattern of responses as the relative measures, showing decreases in occipital cortex and increases in left temporal cortex. Comparison of the relative measures and the SPM analyses obtained with lorazepam data revealed a similar pattern of effects, with relative decreases in occipital cortex (-7.8 ± 4.8%) and relative increases in left temporal cortex (+3.8 ± 5.7%). Lorazepam, but not ethanol, also decreased thalamic metabolism (-11.2 ± 7.2%). Conclusions: These results support similar though not identical mechanisms for the effects of alcohol and benzodiazepines on brain glucose metabolism. The fact that lorazepam, but not alcohol, reduced thalamic metabolism, an effect associated with sleepiness, could explain the higher sedative effects of lorazepam than of alcohol.

The prognostic value of cyclin D1, p53, and MDM2 protein expression in uveal melanoma.

Abstract: Malignant uveal melanoma is the commonest primary intraocular tumour in adults. It metastasizes frequently and 50% of patients die within 10 years of diagnosis. The expression of cyclin D1, p53, and MDM2 in uveal melanoma and their relationship to metastasis-free 5-year survival was determined, in order to investigate whether these proteins help to distinguish those patients with a favourable prognosis from those with a poorer one. Ninety-six eyes enucleated for uveal melanomas were immunohistochemically analysed for the protein expression of cyclin D1 and related cell-cycle markers, p53 and MDM2. The evaluation of the specimens was undertaken by two independent pathologists without knowledge of the outcome. Statistical analysis of clinical, morphological, and immunohistological features was performed. A 'favourable outcome' was defined as survival of at least 5 years after diagnosis, without metastases (n=57). An 'unfavourable outcome' was defined as death from metastases within the first 5 years after diagnosis of uveal melanoma (n=39). Cyclin D1 positivity (>15% positive tumour cells) as well as p53 positivity (>15% positive tumour cells) was associated with an unfavourable outcome (for cyclin D1: odds ratio=4. 2, 95% confidence interval 1.5-11.8, p=0.006; for p53: odds ratio=3. 2, 95% confidence interval 1.1-9.3, p=0.03). In addition, cyclin D1 positivity was associated with the presence of extraocular extension of the tumour (p=0.01), with the mixed or epithelioid cell type (p=0. 02), and with the tumour cell MIB-1 positivity (p=0.0001). MDM2 immunoreactivity of the tumour cells showed a potential correlation with clinical outcome (odds ratio=2.1, 95% confidence interval 0.8-5. 8, p=0.13). Multiple logistic regression models showed that cyclin D1 positivity is an independent prognostic factor after control for other prognostic markers. The expression of cyclin D1 in uveal melanoma is associated with a more aggressive course and histologically unfavourable disease. This could serve as a further independent prognostic factor in uveal melanoma.

Molecular Recognition of Carbohydrates by Artificial Polypyridine and Polypyrimidine Receptors

Abstract: Despite their acyclic structure, the simple host molecules 1 and 2 can effectively hydrogen bond to monosaccharides. They show marked binding affinities to glucopyranosides in chloroform, and they are able to participate in three-dimensional recognition of monosaccharides.

Naked Au55 clusters: dramatic effect of a thiol-terminated dendrimer

Abstract: Reaction of the thiol-terminated fourth-generation dendrimer 2-G4 (96 SH groups) with the gold cluster compound Au55(PPh3)12Cl6 in a 3:1 molar ratio in dichloromethane results in the formation of bare Au55 clusters. The cuboctahedrally shaped Au55 particles coalesce to well-formed microcrystals (Au55) infinity. The role of the dendrimer is not only to remove the phosphine and chlorine ligands but also to act as an ideal matrix for perfect crystal growth. Transmission electron microscopy (TEM), small- and wide-angle X-ray diffraction (SAXRD and WAXRD) measurements indicate a structure where rows of edge-linked Au55 building blocks form a distorted cubic lattice. The X-ray data fit best if a 5% reduction of the Au-Au bond length in the Au55 clusters is assumed, in agreement with previous extended X-ray absorption fine structure (EXAFS) measurements. Energy-dispersive X-ray spectroscopy (EDX) analyses and IR investigations show the absence of PPh3 and Cl in the microcrystals.

Strategies for the Anchoring of Metal Complexes, Clusters, and Colloids Inside Nanoporous Alumina Membranes

Abstract: Two complementary strategies are presented for the anchoring of molecular palladium complexes, of cobalt or platinum clusters or of gold colloids inside the nanopores of alumina membranes. The first consists in the one step condensation of an alkoxysilyl functional group carried by the metal complex with the hydroxy groups covering the surface of the membrane pores. Thus, using the short-bite alkoxysilyl-functionalized diphosphane ligands (Ph2P)2N(CH2)3Si(OMe)3 (1) and (Ph2P)2N(CH2)4SiMe2(OMe)] (2) derived from (Ph2P)2NH (dppa) (dppa bis(diphenylphosphanyl)amine), the palladium complexes [Pd(dmba)(kappa2-P,P-(Ph2P)2N(CH2)3Si(OMe)3)] Cl (3) and [Pd(dmba)[kappa2-P,P-(Ph2P)2N(CH2)4SiMe2(OMe)]]Cl (4) (dmba-H = dimethylbenzylamine). respectively, were tethered to the pore walls. After controlled thermal treatment. confined and highly dispersed palladium nanoparticles were formed and characterized by transmission electron microscopy (TEM). This method could not be applied to the cobalt cluster [Co4(CO)8(mu-dppa)[mu-P,P-(Ph2P)2N(CH2)4SiMe2(OMe)]] (7) owing to its too limited solubility. However, its anchoring was achieved by using the second method which consisted of first derivatizing the pore walls with 1 or 2. The covalent attachment of the diphosphane ligands provides a molecular anchor that allows subsequent reaction with the cluster [Co4(CO)10(mu-dppa)] 6 to generate anchored 7 and this step was monitored by UV/Vis spectroscopy. In addition, the presence of carbonyl ligands in the cluster provides for the first time a very sensitive spectroscopic probe in the IR region which confirms both cluster incorporation and the retaining of its molecular nature inside the membrane. The presence of the bridging dppa ligand in 6 provides additional stabilization and accounts for the selectivity of the procedure. Using this method, platinum clusters (diameter ca. 2 nm) and gold colloids (diameter ca. 13 nm) were immobilized after passing their solution through the functionalized membrane pores. The resulting membranes were characterized by TEM which demonstrated the efficiency of the complexation and showed the high dispersion of the metal loading. The successful application of these methods has demonstrated that nanoporous alumina membranes are not only unique supports to incorporate metal complexes, clusters, or colloids but can also be regarded as functional matrices or microreactors, thus opening new fields for applications.

C–H group acidity and the nature of C–H···N interactions: crystal structural analysis of pyrazine and methyl substituted pyrazines

Abstract: Crystal structures of methyl-, 2,3-, 2,5- and 2,6-dimethyl-, and trimethylpyrazine (2–6) have been determined by X-ray diffraction analysis. Four of these compounds (2–4 and 6) are liquids and their single crystals have been grown in situ on the diffractometer using a miniature zone melting procedure. These structures are analysed together with those of pyrazine (1) and tetramethylpyrazine (7) in the context of C–H···N interactions. Compounds 1–7 were chosen because they contain only C, H and N atoms, and also C–H groups of variable acidity. This facilitates the comparison of C–H···N geometries with respect to the C–H group acidity. Compounds 1 and 2 are dominated by sp2 C–H groups in their molecules and their supramolecular structures are generated by sp2 C–H···N. On the other hand the domination of sp3 C–H groups at the molecular level in 6 and 7 results in crystal structures that are governed by sp3 C–H···N. A balance of sp2 and sp3 C–H groups in the dimethyl derivatives 3–5 leads to a situation where both kinds of C–H groups play a structure directing role. While the sp2 C–H groups form C–H···N, the sp3 C–H groups are involved in C–H···π interactions. Thus the C–H group interactions follow a property unique to hydrogen bonds—stronger donors interact with stronger acceptors while weaker donors approaching weaker acceptors. Inter-structural comparison revealed that H···N distances decrease with increasing C–H acidity and therefore C–H···N interactions could be considered as weak hydrogen bonds.

Is there a graft-versus-leukaemia effect in the absence of graft-versus-host disease in patients undergoing bone marrow transplantation for acute leukaemia?

Abstract: During a 13-year period, 5200 autografts, 1039 HLA-identical sibling transplants without acute or chronic graft-vs.-host disease (GVHD) and 67 twins were reported to the European Group for Blood and Marrow Transplantation EBMT. Follow-up time was a median of 32 months. Diagnoses were acute myeloid leukaemia (AML, 4521) and acute lymphoblastic leukaemia (ALL, 1785) in first complete remission. The probability of relapse at 5 years was 51 +/- 1% in the autografts, 45 +/- 8% in the twins and 34 +/- 2% among the HLA-identical siblings (auto vs. sibs, P < 0.0001). In multivariate analyses, the following factors were significantly associated with an increased risk of relapse: ALL vs. AML M3 [relapse rate (RR) 2.29, P < 0.0001], AML non-M3 vs. AML M3 (RR 1.8, P < 0.0001), autograft vs. sibling transplant (RR 1.76, P < 0.0001), interval diagnosis to transplantation < 261 d (RR 1.45, P < 0.001) and other conditioning vs. total body irradiation (RR 1.16, P = 0.001). Transplant-related mortality was the same in the three groups at approximately 10% at 2 years. Five-year leukaemia-free survival was 42 +/- 1% in the autografts, 44 +/- 8% in the twins and 58 +/- 2% among the siblings (auto vs. sibs, P < 0.0001). The factors significant for relapse were also significant in multivariate analyses for leukaemia-free survival. In addition, children had a significantly better leukaemia-free survival than adults (RR 0.82, P < 0.0001). Recipients of bone marrow from HLA-identical siblings without GVHD had a lower risk of relapse and a better leukaemia-free survival than recipients of autografts. This may be as a result of a graft-vs.-leukaemia effect in the absence of GVHD.

Calcium influx in human uterine epithelial RL95-2 cells triggers adhesiveness for trophoblast-like cells. Model studies on signalling events during embryo implantation

Abstract: RL95-2 is a human uterine epithelial cell line that exhibits adhesion competence on its apical surface for trophoblast-like JAR cells. Using confocal microscopy and an adhesion assay we have found that changes in intracellular free calcium ([Ca(2+)](i)) in RL95-2 cells are involved in binding of JAR spheroids. Impact of spheroids upon, and movement of spheroids across, monolayers of RL95-2 cells produced a transient increase in [Ca(2+)](i). Pretreatment of RL95-2 cells with the Ca(2+) channel inhibitor, diltiazem, reduced the [Ca(2+)](i) increase. Interestingly, resting of JAR spheroids on RL95-2 cells caused no detectable alterations in [Ca(2+)](i) although cell-cell bonds were formed during prolonged contact. However, separation of established bonds did produce an increase in [Ca(2+)](i) which could be reduced by the Ca(2+) channel blocker, SKF-96365, but not by diltiazem. SKF-96365 also reduced adhesion of JAR spheroids to RL95-2 cells. In all experiments, the increase in [Ca(2+)](i) was due to influx from the external medium, as it could be blocked both by removing extracellular Ca(2+) and by nickel. These results suggest that the plasma membrane of uterine RL95-2 cells contains two types of Ca(2+) channels that are involved in trophoblast adhesion, i.e. diltiazem-sensitive channels contributing to initiation of JAR cell binding and SKF-96365-sensitive channels participating in a feedback loop that controls the balance of bonds.

Supporting collaborative activities in computer integrated classrooms-the NIMIS approach

Abstract: The paper presents the concept of a collaborative computer integrated classroom (CiC) specially designed to achieve a unique combination of interactive and collaborative software with spatial arrangements, special furniture, and new peripherals including furniture ("roomware"). Although, technologically innovative, the CiC approach respects grown pedagogical traditions and classroom procedures. In line with the notion of ubiquitous computing, it tries to augment the real classroom instead of defining a virtual learning environment. Based on these principles, the European NIMIS project has put into practice a specific classroom environment for early learning with general tools and specific applications supporting literacy-related activities. In addition to the collaborative nature of the classroom scenario as such, specific mechanisms for co-construction in shared workspaces are provided.

Human herpesvirus 6 is an important pathogen in infectious lung disease after allogeneic bone marrow transplantation.

Abstract: Two hundred and ten bronchoalveolar lavage (BAL) samples were obtained from 50 patients 10 days before and on defined days after allogeneic bone marrow transplantation (BMT). The samples were examined for human cytomegalovirus (HCMV) and human herpesvirus-6 (HHV-6) by polymerase chain reaction (PCR). Fifteen patients (30%) had a positive result for HCMV in at least one sample and 25 (50%) were positive for HHV-6 in at least one sample. Five patients developed HCMV-associated interstitial pneumonia (HCMV-IP) within 100 days after allogeneic BMT. Four of these patients were positive for both HCMV and HHV-6. Conspicuous HHV-6 positivity was detected in BAL samples obtained because of respiratory symptoms. No association was found between detection of HHV-6 and acute graft-versus-host disease. Engraftment failure or a delay in engraftment was observed in none of the 50 patients. The data from this study indicate that HHV-6 is a pathogen in HCMV-associated, as well as in non-HCMV-associated infectious lung disease after BMT.

Role of weak hydrogen bonds in the crystal structures of phenazine, 5,10-dihydrophenazine and their 1:1 and 3:1 molecular complexes

Abstract: Phenazine (1) and 5,10-dihydrophenazine (2) form not only a 1:1 complex (3), as expected from N–H···N hydrogen bond requirements, but surprisingly also a 3:1 complex (4). Single crystal X-ray analyses of compound 2 and complexes 3 and 4 have been carried out. While the overall packing in complex 3 is as efficient as in pure 1 and 2, acidic C–H groups, which contribute actively to the structural assembly in pure 2, are not involved in hydrogen bonding in 3. It is shown that the quest for hydrogen bonding by these C–H groups steers the formation of complex 4 with an unprecedented N–H···N and C–H···N hydrogen bond mediated tape structure.

Renal growth in children with severe vesicoureteral reflux: 10-year prospective study of medical and surgical treatment: the International Reflux Study in Children (European branch).

Abstract: PURPOSE: To determine whether medical or surgical treatment better promotes renal growth in children with severe vesicoureteric reflux (VUR) and to examine factors influencing renal growth. MATERIALS AND METHODS: Three hundred two children younger than 11 years with urinary tract infection and grade III or IV VUR were randomly assigned to surgical (n = 149) or medical (n = 153) treatment and were followed up at serial intravenous urography for up to 5 years; 223, for up to 10 years (surgical, n = 110; medical, n = 113). Renal size was measured planimetrically on serial intravenous urograms and was related to the virtual height of L1 through L3 by expressing it as an SD score. RESULTS: There was no significant difference in mean renal growth between patients treated surgically or those treated medically after 5- or 10-year follow-up. Bilateral renal size of 80 surgical and 75 medical patients remained within 1 SD score. In patients entering the study at 2 years of age or younger and in those with grade IV ...

SETA: a novel SH3 domain-containing adapter molecule associated with malignancy in astrocytes.

Abstract: Differential display polymerase chain reaction analysis was used to compare five differentiation states of the O-2A progenitor-like cell line CG4: progenitor cells and cells at 12 h or 4 days after the induction of differentiation into oligodendrocytes or astrocytes. This led to the identification of 52 sequence tags that were expressed differentially with cellular phenotype. One sequence was upregulated during differentiation of CG4 cells and represented a novel gene that we named SETA (SH3 domain-containing gene expressed in tumorigenic astrocytes). This gene encodes an SH3 domain-containing adapter protein with sequence similarity to the CD2AP (CD2 adapter protein) and CMS (Cas ligand with multiple Src homology) genes. SETA mRNA was expressed at high levels in the developing rat brain but was barely detectable in the normal adult rat or human brain. However, SETA mRNA was found in approximately one half of the human gliomas tested, including astrocytomas grades II, III, and IV, as well as oligodendrogliomas, mixed oligoastrocytomas, and human glioma-derived cell lines. A rat glioma generated by treatment with the alkylating carcinogen ethylnitrosourea on postnatal day 1 and a derived cell line also expressed SETA mRNA. Furthermore, in an in vitro model of astrocytoma progression based on p53-/- astrocytes, expression of SETA was restricted to cells that are tumorigenic.

Biological effects of stroma-derived factor-1α on normal and CML CD34 + haemopoietic cells

Abstract: Biological effects of stroma-derived factor-1α on normal and CML CD34 + haemopoietic cells

Monetary regionalism: regional integration without financial crises

Abstract: The financial crises of the late 1990s have marked a watershed for the global economy and for regionalism. Prior to these crises, deregulation and liberalisation, in particular of financial markets, enjoyed widespread support. On the other hand, regional integration was aimed at improving conditions for regional trade and was based on Bela Balassa’s forty year old theory of regional integration. At the beginning of the 21 st century, the theoretical approach to regional integration will have to be a different one. Regionalism will have to offer enhanced protection against financial crises, whereas trade liberalisation in an era of rapid trade liberalisation both offers fewer benefits and may be too complicated to implement due to high administrative costs associated in particular with free trade areas. The aim of this paper is to provide a theoretical framework for the emerging new monetary regionalism. Regions that wish to strengthen their co-operation in monetary and financial affairs today have the option of regionalism without trade agreements. East Asia is the most likely candidate for the implementation of monetary regionalism, also because East Asian policy makers continue to be frustrated with the lack of progress in the IMF’s reform process.

MRI of intracranial toxoplasmosis after bone marrow transplantation

Abstract: Toxoplasma encephalitis was confirmed by biopsy in three patients with bone marrow (BMT) or peripheral blood stem-cell transplantation (PBSCT). All had MRI before antimicrobial therapy. The intensity of contrast enhancement was very variable. One patient had one large, moderately enhancing cerebral lesion and several smaller almost nonenhancing lesions. The second had small nodular and haemorrhagic lesions without any enhancement. The third had late cerebral toxoplasmosis and showed multiple lesions with marked contrast enhancement. The moderate or absent contrast enhancement in the two patients in the early phase of cerebral toxoplasmosis may be related to a poor immunological response, with a low white blood cell count in at least one patient. Both received higher doses of prednisone than the patient with late infection, leading to a reduced inflammatory response. In patients with a low leukocyte count and/or high doses of immunosuppressive therapy, typical contrast enhancement may be absent.

The detection of wt-1 transcripts is not associated with an increased leukemic relapse rate in patients with acute leukemia after allogeneic bone marrow or peripheral blood stem cell transplantation

Abstract: We studied the role of wt-1 as a minimal residual disease (MRD) marker in 46 patients with acute leukemia (AL) (1st CR n = 24; 2nd CR n = 9, in relapse n = 13) after allogeneic bone marrow or peripheral blood stem cell transplantation. Prior to allogeneic transplant, wt-1 transcripts were detected by PCR in 38 of 46 patients (83%) with AL. After transplant, in 14 of 38 patients (37%) wt-1 transcripts were detected in at least one PCR assay at a median of 12 months post transplant (range 1-89 months). Twelve of the 38 patients relapsed after transplant, but only seven of the 12 were wt-1 positive after transplant. In five relapsing patients the wt-1 test remained negative 0 to 3 months prior to relapse. On the other hand, only seven of 14 patients with a positive test for wt-1 after transplant, relapsed consecutively. In 17 of the 46 study patients chromosomal abnormalities had been found prior to transplant (AML-M4eo with inv16 n = 7, AML-M2 with t(8;21) n = 3, AML-M3 with t(15;17) n = 1, AML-M5 with t(4;11) n = 1, ALL with t(9;22) n = 5). In these 17 patients, we analyzed the wt-1 transcript simultaneously with a specific chimeric transcript characteristic for the corresponding chromosomal abnormality. In 32 of 45 samples (71%) the results for the MRD marker and wt-1 transcript were concordant, but differed in 13 patients. We conclude that detection of wt-1 transcripts does not predict leukemic relapse reliably and is therefore not a suitable MRD marker in patients with acute leukemia after allogeneic BM or PBSC transplantation. Bone Marrow Transplantation (2000) 25, 91-96.

Why is the melting point of propane the lowest among n-alkanes?

Abstract: Ethane, propane and n-butane form layer structures in the solid state. By describing their molecular geometries as a rectangle, an irregular pentagon and an irregular hexagon, respectively, it is shown here that propane cannot close-pack like its congeners. The melting point of propane is therefore lower than expected in the series.

Molecular aspects of arrhythmias associated with cardiomyopathies.

Abstract: The increased risk of sudden cardiac death in patients with myocardial hypertrophy and heart failure is the result of remodeling that occurs in both the myocyte and interstitial compartments of the heart. Action potential prolongation is a hallmark of hypertrophied and failing myocardium and is a consequence of differential expression and function of membrane currents and transporters. Functional downregulation of K currents in the ventricle is a recurring theme in hypertrophy and failure; the reduction in the density of the transient outward current (I(to)) is the most consistent observation, whereas data on the density of the inward (I(K1)) and the delayed rectifier (I(K)) currents are more contradictory. The altered intracellular Ca handling of the myopathic hearts prolongs the decay of the L-type Ca current and favors extrusion of cytosolic Ca2+ via the Na+-Ca2+ exchanger. The interaction between such altered membrane currents and a changed neurohumoral milieu creates a substrate that is highly susceptible to potentially lethal ventricular arrhythmias.