Charge and Spin Order Dichotomy in NdNiO_{2} Driven by the Capping Layer.

Superconductivity in infinite-layer nickelates holds exciting analogies with that of cuprates, with similar structures and 3d-electron count. Using resonant inelastic x-ray scattering, we studied electronic and magnetic excitations and charge density correlations in Nd_{1-x}Sr_{x}NiO_{2} thin films with and without an SrTiO_{3} capping layer. We observe dispersing magnons only in the capped samples, progressively dampened at higher doping. We detect an elastic resonant scattering peak in the uncapped x=0 compound at wave vector (∼⅓,0), remindful of the charge order signal in hole doped cuprates. The peak weakens at x=0.05 and disappears in the superconducting x=0.20 film. The role of the capping on the electronic reconstruction far from the interface remains to be understood.

Tattoo removal by non-professionals--medical and forensic considerations.

Tattoos are common phenomena in the western world and the demand for their removal has become widespread in the recent years. The introduction of quality-switched lasers has provided an effective removal method that is increasingly being exploited by tattoo studios themselves. Dermatologists, however, are frequently confronted with complications and side effects of tattoo removals that were performed by non-professionals. The objective of this study is to assess potential risks and pitfalls of laser tattoo removal when performed by medical laymen. The methods followed are systematic and evidence-based review of the literature. Four major problem areas were identified: rare but potentially severe allergic or toxic effects of decomposition products of the tattoo pigments; bodily harm caused by out-of-specification usage of the laser devices; malignant disease that is obscured within the area of a tattoo and requires meticulous dermatological diagnosis; and insufficient pre-operative consultation of patients about the risks, side effects and realistic expectations on the therapeutic outcome. We came to a conclusion that tattoo laser removal by medical laymen is unacceptable from the point of view of patient safety and the laws need to ban this practice swiftly.

Frequency and structure of t(14;18) major breakpoint regions in non-Hodgkin's lymphomas typed according to the Kiel classification: analysis by direct DNA sequencing.

We have examined 165 unselected cases of non-Hodgkin's lymphomas for rearrangements involving the t(14;18) major breakpoint region using a polymerase chain reaction (PCR) and direct sequencing of amplified major breakpoint region bcl-2/JH junctional regions. The lymphomas, diagnosed according to the updated Kiel classification, consisted of 33 centroblastic-centrocytic, 37 centroblastic, 27 immunocytic, 10 immunoblastic, 10 centrocytic, 2 lymphoblastic, 2 Ki-1-positive anaplastic large cell, 14 peripheral T-cell, and 4 unclassified lymphomas. In addition 18 chronic lymphocytic leukemias, 2 hairy cell leukemias, and 6 plasmacytomas were studied. In 17 cases a bcl-2/JH gene fusion sequence was amplified by PCR. A bcl-2/JH gene fusion was detected only in three lymphoma subgroups: 13 of 33 centroblastic-centrocytic (39%), 2 of 37 centroblastic (6%), and 2 of 27 immunocytic (8%) were positive. In two cases, major breakpoint region bcl-2 rearrangements verified by genomic Southern analysis were not detected by PCR. Direct sequencing of all 17 PCR-amplified, previously uncharacterized t(14;18) junctional regions provided corroborating evidence for the specificity of the assay. The procedure gave sequencing results even from limited amounts of lymphoma cells as obtained by fine needle aspiration of lymph nodes or from clinically uninvolved sites. Clone-specific sequences were identified due to the involvement of different JH segments, the variations among the exact JH and bcl-2 breakpoint positions, and the extensive incorporation of junctional region (D-) N-nucleotides. These clone-specific sequences allow accurate identification of clinically occult lymphoma cells and reduce the threat of false positive results. The finding of exceptionally long intervening sequences in some of the junctions and the partial homology with published DH segments in three cases support the view that some of the putative N-regions harbor DH regions.

Chromatofocusing combined with the ELISA technique. A sensitive method for the analysis of immune complexes.

A sensitive method which permits analysis of IgG containing circulating immune complexes without detailed knowledge of the nature of the antigens and the specificity of the antibodies involved is described. Soluble BSA: anti-BSA were used as model immune complexes and isolated from serum. The procedure involves the use of gel chromatography for the separation of the high molecular weight fraction containing the immune complexes as measured by binding to 125I-labeled Clq, followed by absorption of the immune complex fraction to immobilized protein A-Sepharose CL-4B. After desorption from protein A-Sepharose the complexes were dissociated and separated into free antigen and antibody by chromatofocusing in the presence of urea. The isolated free antigen and antibody retained their immunological activity as shown by immunodiffusion, binding after their recombination to 125I-labeled Clq, and by recombining antigen and antibody with much enhanced sensitivity using a microplate ELISA system. By means of the ELISA recombination technique it is possible to analyze less than 1 microgram of BSA:anti-BSA model complexes. Application of this technique may provide more information about the nature of immune complex like material associated with diseases.

Common errors in the treatment of suicidal patients.

As a suicidology consultant to a county coroner and to several hospitals, the author has noted 5 common errors by the mental health caretakers in the treatment and management of suicidal patients. Prototypical cases of these errors are presented and discussed along with suggestions for prevention.

High-dose chemotherapy with autologous peripheral blood stem cell transplantation for metastatic gastric leiomyosarcoma.

We report a case of metastatic gastrointestinal leiomyosarcoma treated with high-dose combination chemotherapy and autologous peripheral blood stem cell transplantation. After incomplete surgical resection, enteral, peritoneal and hepatic involvement remained. Postoperatively, standard-dose chemotherapy with etoposide, ifosfamide, cisplatin and epirubicine, and high-dose chemotherapy with the same agents (carboplatin replacing cisplatin) was given. Treatment was well tolerated and the patient remains in complete remission at 36+ months. We conclude that high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation may be of use as treatment for inoperable residual disease after resection of the primary lesion in gastrointestinal and other soft tissue sarcomas.

Metastatic breast cancer with constantly low CEA blood levels. A subgroup with unfavorable prognosis?

The capability of breast cancer to secrete CEA might have biological significance. In 105 patients with metastatic breast cancer serial CEA determinations and clinical follow-up data were available during progression of disease up to death. In this series, 39 patients (37%) had constantly low CEA levels (less than 10 ng/ml), whereas 66 patients (63%) showed CEA values exceeding 10 ng/ml with progression. The patients with low CEA levels had significantly shorter median survival times (P = 0.001) after mastectomy (39 versus 65 months) and after recurrence (18 versus 28 months) than the patients with high CEA levels. This difference was due first to a poor-risk group of 13 patients with rapidly disseminating tumors, very short survival (less than 12 months), and low CEA levels. Secondly, there were more patients with pulmonary involvement and unfavorable prognosis and fewer patients with osseous metastases and long survival in the low-CEA group. In conclusion, there might be a subtype of breast cancer with rapid progression and low CEA secretion. This clinical observation has to be confirmed by histological grading and CEA staining of these tumors.

Polymerase Chain Reaction Analysis of t(14;18) Junctional Regions in B-Cell Lymphomas.

The polymerase chain reaction (PCR) procedure was used for rapid and highly specific amplification of the t(14;18) bcl-2/JH DNA junctional regions in B-cell lymphomas. By using Taq-polymerase and relatively long oligonucleotide primers-a 33-mer for bcl-2 and an universal 25-mer complementary to the JH consensus sequence-the primer annealing and primer extension steps could be carried out at the same temperature (70°C), thus markedly reducing the reaction time and significantly improving the specificity of the reaction. The specificity of the amplification allowed visual identification of the bcl-2/JH PCR-products in ethidium bromide stained agarose gels. DNA-sequence analysis of PCR-amplified, previously uncharacterized t(14; 18) junctional regions, confirmed the specificity of this assay. Moreover, preliminary data show that the procedure is capable of documenting the presence of occult lymphoma cells in both the peripheral blood and bone marrow.

Neural network models and the visual cortex: the missing link between orientation selectivity and the natural environment.

Orientation selectivity is a basic property of neurones in the visual cortex of higher vertebrates. Such neurones can be seen to act as 'feature detectors', which provide an efficient cortical representation of the outside world. More recently, the removal of correlations between the signals of cortical neurones has been suggested as suitable theoretical concept for explaining the development of receptive fields. Corresponding neural network simulations yielded oriented 'receptive field' structures resembling those observed by neurophysiologists. The findings suggest that the 'decorrelation approach' can provide a causal relationship between characteristics of the physical world and brain function. However, we were able to reveal a basic deficit of the decorrelation approach which we illustrate by the construction of two artificial 'worlds', a 'Gaussian' one and an 'orientation-only' one. We show that, according to the decorrelation approach, oriented environmental features would be neither necessary nor sufficient for the development of oriented receptive fields. Thus the link between environmental structure and cortical orientation selectivity still awaits a theoretical explanation.

DNA single and double strand breaks induced by aliphatic and aromatic aldehydes in combination with copper (II).

The aliphatic n-butyr-and n-valeraldehyde as well as the aromatic benz- and anisaldehyde induced DNA strand breaks in PM2 DNA in the presence of CuCl2. Neither aldehydes nor CuCl2 alone showed DNA breakage properties. The maximum of single strand breaks (SSBs) induced by the combination of CuCl2 and aldehydes was dependent on the CuCl2-concentration. The aliphatic aldehydes induced SSBs and double strand breaks (DSBs) at lower concentrations than aromatic aldehydes when optimal CuCl2 concentration were used. Catalase and neocuproine nearly completely inhibited strand break formation induced by aromatic aldehydes/CuCl2. The prevention of strand breaks induced by aliphatic aldehydes/CuCl2 was less effective. While the inhibition by neocuproine was only 25%, catalase was totally ineffective. In all aldehydes/CuCl2 mixtures the formation of Cu(I) was observed. The results point to different DNA damaging species produced during redox reactions of aromatic and aliphatic aldehydes in combination with CuCl2.

Different DNA damaging species as a result of oxidation of n-butyraldehyde and iso-butyraldehyde by Cu(II).

The isomers n- and iso-butyraldehyde (BuA) in combination with Cu(II) induced single and double strand breaks in PM2 DNA, whereas the aldehydes, or Cu(II) alone had only negligible effect. The DNA damage was the result of radical oxidations of the aldehydes under formation of Cu(I). Cu(I) formation was independent of molecular oxygen. Extensive DNA degradation was only observed in the presence of molecular oxygen. Characterization of DNA damage pointed to different ultimate DNA damaging species. While catalase and neocuproine inhibited strand break formation induced by iso-BuA/Cu(II) to a high degree, these inhibitors were less effective in the n-BuA/Cu(II) reaction. On the other hand, sodium azide showed a high strand break inhibition in the n-BuA/Cu(II) reaction, but low inhibition in the iso-BuA/Cu(II) reaction. 2-Deoxyguanosine was hydroxylated in the 8-position by iso-BuA/Cu(II) but little reaction occurred with n-BuA/Cu(II). Chemiluminescence was detected during both BuA/Cu(II) reactions, whereby the intensity of the luminescence signal was 3.5-fold higher for n-BuA/Cu(II) than for iso-BuA/Cu(II). We suppose that the copper(II)-driven oxidation of n- and iso-BuA proceeds via different pathways with different DNA damaging consequences. Whereas the oxidation of iso-BuA mainly results in damage by .OH-radicals, the oxidation of n-BuA may lead to a radical reaction chain whereby excited states are involved and the resulting DNA-damaging species are not .OH-radicals.

Relative determination of W-values for alpha particles in tissue-equivalent and other gases.

W (the average energy to form an ion pair) for 5.4 MeV 241Am alpha particles in a Rossi-type tissue-equivalent (TE) gas, argon and methane was determined to an accuracy better than 0.2% using a new automated data handling system. A vibrating reed electrometer and current digitiser were used to measure the current produced by completely stopping the alpha particles in a large cylindrical ionisation chamber. A multichannel analyser, operating in a slow multiscaler mode, was used to store pulses from the current digitiser. The dwell time, of the order of 60 min per channel, was selected with an external timer gate. Current measurements were made at reduced pressures (200 Torr) to reduce ion recombination. The average current, over many repeated measurements, was compared to the current produced in nitrogen and its previously published W-value of 36.39+/-0.04 eV per ion pair. The resulting W-values were, in eV per ion pair, 26.29+/-0.05 for argon, 29.08+/-0.03 for methane and 30.72+/-0.04 for TE gas, which had an analysed composition of 64.6% methane, 32.4% CO2 and 2.7% nitrogen. Although the methane and argon values agree within 0.1% with previously published values, the value for TE is 1.2% lower than the single previously reported value.

Synergistic DNA damage by oxidative stress (induced by H2O2) and nongenotoxic environmental chemicals in human fibroblasts.

Genotoxic combination effects of oxidative stress (induced by H2O2) and eight nongenotoxic environmental chemicals (4-chloroaniline, 2,3,4,6-tetrachlorophenol, lindane, 2,4-dichloroacetic acid (2,4-D), m-xylene, glyphosate, nitrilotriacetic acid and n-hexanol) were determined in human fibroblasts. Genotoxicity was measured quantitatively by the single cell gel electrophoresis assay. The nongenotoxic chemicals were used in non cytotoxic concentrations. H2O2 was used in concentrations producing low (50 microM) and no cytotoxicity (40 microM). All environmental chemicals acted in a synergistic way with H2O2 except DMSO which effectively inhibited H2O(2)-induced DNA damage. The most effective enhancers were 4-chloroaniline, 2,3,4,6-tetrachlorophenol, m-xylene, and n-hexanol. Synergistic effects of hexanol/H2O2 were still evident at a concentration of 0.09 noec (no observed effect concentration). In contrast to synergistic DNA damage in the cell antagonism was found measuring DNA breakage in isolated PM2 DNA. From the results we concluded that synergisms between H2O2 and nongenotoxic chemicals may be a general phenomenon which is not observed on the level of isolated DNA.

Synergistic DNA damaging effects of malondialdehyde/Cu(II) in PM2 DNA and in human fibroblasts.

Malondialdehyde (MDA) is a product of lipid peroxidation (LPO). In combination with CuCl2 MDA induced single strand breaks in PM2 DNA whereas MDA or CuCl2 alone had no effect. Cu(II) oxidized MDA by a radical mechanism under formation of Cu(I). DNA strand break induction was inhibited by catalase (98%), neocuproine (76%) and DMSO (61%). The synergistic damaging effect of MDA and Cu(II) was also demonstrated in human fibroblasts measured by alkaline elution. The combination MDA/CuCl2 caused extensive DNA breakage while neither MDA nor CuCl2 alone induced DNA damage within the cell. Synergistic cytotoxic effects were observed 18 h after a simultaneous treatment of the cells with MDA and CuCl2 for 1 h.

Characterization and applicability of a cytotoxicity assay determining growth inhibition after a 1-hour treatment with xenobiotics in human cell culture.

A cytotoxicity assay to determine growth inhibition after a 1-hr treatment with xenobiotics in serum-free medium and subsequent re-incubation in serum-containing medium without test chemicals was characterized and optimized for cytotoxicity screening. Our results indicated that after treatment of human fibroblasts with the test chemicals a 44-hr re-incubation period is most suitable for measuring the growth inhibitory effects of a broad spectrum of chemicals. Applying the assay, the activity to inhibit growth by 10% (log IC(10)) correlated with the lipophilicity (specified as octanol-water partition coefficient = log K(ow)) of 19 xenobiotics. The linear regression coefficient was r = 0.91. This close correlation between toxicity and lipophilicity shows that the test, which avoids long-term incubation in serum-containing medium, is suitable for cytotoxicity screening and structure-activity analysis.

Nonlinear image operators for the evaluation of local intrinsic dimensionality.

Local intrinsic dimensionality is shown to be an elementary structural property of multidimensional signals that cannot be evaluated using linear filters. We derive a class of polynomial operators for the detection of intrinsically 2-D image features like curved edges and lines, junctions, line ends, etc. Although it is a deterministic concept, intrinsic dimensionality is closely related to signal redundancy since it measures how many of the degrees of freedom provided by a signal domain are in fact used by an actual signal. Furthermore, there is an intimate connection to multidimensional surface geometry and to the concept of ;Gaussian curvature'. Nonlinear operators are inevitably required for the processing of intrinsic dimensionality since linear operators are, by the superposition principle, restricted to OR-combinations of their intrinsically 1-D eigenfunctions. The essential new feature provided by polynomial operators is their potential to act on multiplicative relations between frequency components. Therefore, such operators can provide the AND-combination of complex exponentials, which is required for the exploitation of intrinsic dimensionality. Using frequency design methods, we obtain a generalized class of quadratic Volterra operators that are selective to intrinsically 2-D signals. These operators can be adapted to the requirements of the signal processing task. For example, one can control the "curvature tuning" by adjusting the width of the stopband for intrinsically 1-D signals, or the operators can be provided in isotropic and in orientation-selective versions. We first derive the quadratic Volterra kernel involved in the computation of Gaussian curvature and then present examples of operators with other arrangements of stop and passbands. Some of the resulting operators show a close relationship to the end-stopped and dot-responsive neurons of the mammalian visual cortex.

The efficacy of large volume plasma exchange in chemotherapy resistant malignancies.

Chemotherapy resistance in cancer patients may be due to serum blocking factors, which can be diminished or eliminated by large volume plasma exchange (PE). This procedure was performed with the IBM blood cell separator in 69 patients resistant to chemotherapy. Immediately after PE the chemotherapy was given but it was reinstituted, if clinical evaluation revealed partial remission, minor response or no change. 37 out of 69 patients (53.6%) responded again, 32 (46.4%) did not. Response duration ranged from 2 to 45 weeks. Best clinical results were obtained in patients with colorectal cancer, 15 out of 23 showed improvement between 4 to 45 weeks. Serum blocking activity was measured using a modified mixed lymphocyte culture assay (MLC). There was a 80% positive correlation between clinical course of patients and MLC levels, if basic activity before the first PE was compared to MLC inhibition before the following PE's.