Synthesis and spectroscopic characterization of dicyclohexyltin derivatives of dipeptides, andin vitro effects against MDA-MB 231 breast cancer cells…

1992

Dicyclohexyltin derivatives Cy2SnL (Cy = cyclohexyl) of the dipeptides H2L, glycylglycine, glycylalanine, alanylglycine, glycylvaline, glycylmethionine, glycylphenylalanine and glycyltyrosine, have been obtained by neutralization of Cy2SnO and H2L. The crystal structures of Cy2SnL (L = glycylglycinate, glycylalaninate) have been determined by single X-ray diffraction. Tin in each case has a distorted trigonal bipyramidal environment with the dipeptide acting as a tridentate NNO-ligand. From IR-data, and in some cases from 119Sn Mossbauer and 119Sn NMR data, analogous molecular structures are inferred for the other compounds Cy2SnL. Spectroscopic data indicate that the solid-state structures…

Steatocrit test: Normal range and physiological variations in preterm and low-birth-weight full-term newborns

1992

CHARACTERIZATION OF CHRONIC HEPATITIS B IN CHILDHOOD USING MOLECULAR BIOLOGY TECHNIQUES

1992

The introduction of molecular biology techniques in the diagnostics of chronic hepatitis B virus infection proved HBV DNA to be the most sensitive marker of viral replication and infectivity. The aim of our study was to characterize the HBV DNA status in children with chronic hepatitis B with various molecular biology techniques in relation to conventional HBV markers. Methods: 206 sera of 172 and liver tissue of 108 children with chronic hepatitis B infection were investigated by dot blot-, Southern blot-, and in situ hybridization. In dot blot and Southern blot negative specimens polymerase chain reaction (PCR) was performed. Results: 111 of the 206 sera were positive for HBV DNA by dot b…

A new improved synthesis of the 110 K bismuth superconducting phase: freeze-drying of acetic solutions

1992

Abstract Metastability has greatly hindered the separated synthesis of the high-temperature superconducting phases represented as (Bi1−x, Pbx)2Sr2Can−1CunO4 + 2n (n = 2, 2-2-1-2, Tc≈80 K, and n = 3, 2-2-2-3, Tc≈110 K). By careful control of the synthetic variables, it becomes possible to obtain the 110 K phase as the only superconducting one through processing of freeze-dried acetic solutions. This technique leads to homogeneously sized (5–10 μm) micaceous platelets of the superconducting material.

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1992

A series of copolymers are synthesized by repetitive Diels-Alder polyaddition reaction of bifunctional cyclohepta-1,3,5-trienes with bifunctional 1,2,4-triazoline-3,5-diones. The copolymers of different bistriazolinediones with a bisdiene, or of different biscycloheptatrienes with a dienophile, have good solubility in CH2Cl2 and CHCl3, while the homopolymers are poorly soluble. The copolymers were characterized by standard analytical techniques to test the structural regularity of these systems. Due to the kinetic control, it is possible to apply copolymerization statistics to these systems. Based on a model study, it is concluded that alipatic and aromatic bistriazolinediones have the same…

Determination of acetazolamide in human urine samples by reversed-phase high-performance liquid chromatography in the presence of xanthines.

1992

A simple, rapid and selective high-performance liquid chromatographic assay for the determination of acetazolamide in urine samples is described. After extraction with ethyl acetate, the drug is chromatographed on an HP-Hypersil ODS-C18 column with a mobile phase of acetonitrile-phosphate buffer (pH 3) and ultraviolet detection at 275 nm. The efficiency of the extraction, the linearity and the reproducibility of the method permit the evaluation of acetazolamide urinary excretion a long time after its administration.

Siderophores and related outer membrane proteins produced by pseudomonads isolated from eels and freshwater.

1992

A total of 46 environmental pseudomonads, together with six type strains, were examined for their siderophore-producing activity. All strains were able to grow under iron-limiting conditions, gave orange halos in the CAS agar assay, and produced hydroxamates, and some of them also produced phenolate-type compounds. Bioassays showed that all strains, except Pseudomonas aeruginosa, promoted growth of mutant strain Arthrobacter flavescens JG-9, deficient in hydroxamate production, and some of them promoted growth of Salmonella typhimurium enb-1, which requires enterobactin for growth. The presence of iron-regulated outer membrane proteins was observed, the molecular size of the main induced pr…

Semiphenomenological approach to nucleon properties in nuclear-matter

1992

We have evaluated the nucleon self-energy in a model that has proper analytical properties, satisfies the low density theorem and provides values of Im \ensuremath{\Sigma} for high densities comparable to those of realistic microscopic approaches. The model, however, relies only upon the NN experimental cross sections and the empirical spin-isospin interaction, which induces an important polarization of the medium. The results obtained for the spectral functions, occupation numbers, and effective masses are quite reasonable. The model does not give the absolute value of the nucleon self-energy but only differences with respect to the Fermi energy. On the other hand, it provides an easy and …

The significance of serum soluble IL-2 receptor as a marker for active visceral leishmaniasis in Sicilian patients

1992

SUMMARY Sera from nine Sicilian patients with confirmed visceral leishmaniasis (Leishmania donovani infantum; VL), at the moment of the diagnosis, during the course of the disease and after clinical recovery, were analysed for the concentration of soluble IL-2 receptor (sIL-2R). The results show that sIL-2R is a marker of disease activity, since it is in high concentration at the beginning of infection and returns to the normal range following successful chemotherapy. At the same time of serum analysis for sIL-2R, peripheral blood mononuclear cells (PBMC) of VL patients were stimulated with phytohaemagglutinin (PHA) or antigen and supernatant tested for IL-2 and interferon-gamma (IFN-γ) pro…

Effect of the abundance of three predominating copepod species on adequate sample volume and sample size in Bransfield Strait (Antarctic Peninsula) a…

1992

The effect on adequate sample size and sample volume of the abundances of three predominant copepod species, Metridia gerlachei, Calanus propinquus and Calanoides acutus, were studied in Bransfield Strait (Antarctic Peninsula) in the austral summer of 1988–1989 and waters north of the Weddell Sea in 1989–1990. Copepod abundances were higher in the area north of the Weddell Sea, with the exception of Metridia gerlachei, which was evenly distributed over both areas. Local (intra-station) patchiness was not found, indicating random distribution over small areas. In the assessment of inter-station variability in Bransfield Strait, with standard error of the mean set arbitrarily at 20% of the av…

The hydration shell of myoglobin.

1992

The space in the unit cell of a metmyoglobin crystal not occupied by myoglobin atoms was filled with water using Monte Carlo calculations. Independent calculations with different amounts of water have been performed. Structure factors were calculated using the water coordinates thus obtained and the known coordinates of the myoglobin atoms. A comparison with experimental structure factors showed that both the low and the high resolution regime could be well reproduced with 814 Monte Carlo water molecules per unit cell with a B-value of 50 A2. The Monte Carlo water molecules yield a smaller standard R-value (0.166) than using a homogeneous electron density for the simulation of the crystal w…

Parenterale Ernährung in der Behandlung des Minderwuchses bei Adoleszenten mit Morbus Crohn

1992

Growth retardation and delayed puberty occur in 20-35% of children and adolescents with Crohn's disease. Alternate day corticosteroid treatment, use of azathioprine, enteral or parenteral hyperalimentation and surgery have been advocated to reverse growth failure. Because of nonacceptance of elemental diet 7 patients with Crohn's disease and growth retardation received parenteral nutrition for 2-3 months (maximal for more than 30 months in one patient). All of them exhibited a mean weight gain of 10 kg and a mean increase of their height velocity from 2.4 to 7.1 cm/year. Main problems were bacterial infections and dislocations of the central lines. Surgery was performed in 3 adolescents imm…

The dynamic properties of neuronal chromatin are modulated by triiodothyronine.

1992

The effect of triiodothyronine (T3) on the rate of synthesis of nuclear proteins was studied during terminal differentiation of rat cortical neurons cultured in a serum-free medium. To this aim total and acid soluble nuclear proteins were analyzed by different electrophoretic techniques. Our results show that: 1) during maturation in vitro, neuronal nuclei undergo a dramatic change in the rate at which different classes of histones and high mobility group (HMG) proteins are synthesized; the synthetic activity, measured as incorporation of radioactive precursors into nuclear proteins, slows indeed down with age: especially evident is the decrease in core histones synthesis; at day 15, on the…

Synthesis and magnetic characterization of trans-dichloroplatinum blues with creatinine

1992

Abstract By reaction of trans -[Pt II Cl 4 ] 2− with the amidate ligand creatinine two new paramagnetic blue platinum complexes have been obtained, namely violet and green varieties. These complexes have been characterized from thermal analysis, EPR and magnetic susceptibility. The violet complex has been formulated as trans -[Pt(creat)(H 2 O)Cl] 4 Cl. This compound has shown to be very stable, showing an extensive hyperfine structure in the powder EPR spectra. This result is a clear evidence of a tetranuclear oligomeric structure with one delocalized unpaired spin in the unit. EPR spectra in frozen solutions indicate that this mixed-valence complex maintains its oligomeric structure upon d…

Potassic dyke swarm in the Sapucai Graben, Eastern Paraguay: Petrographical, mineralogical and geochemical outlines.

1992

Abstract The western side of the Parana Basin of Brazil extends to central Paraguay, where repeated and widespread magmatic activity developed from Lower Cretaceous to Oligocene, associated with late Mesozoic crustal extension trending NE-SW. In central Paraguay this trend is characterized by a zone of NW-SE normal faults which formed the Asuncion-Sapucai graben, up to 45 km wide and 200 km long, where alkaline rocks occur as volcanic domes, complexes, lava-flows and dykes. These rocks, 128 Ma aged, are dominantly potassic and ne-normative. A swarm of at least 200, mainley NW-SE trending, dykes occurs in the Sapucai region and seems to be formed by two main lineages: tephrite to phonolite (…

Correlation between mortality trends of ischaemic cardiopathy and some nutritional factors in Spain 1968?1986

1992

After describing the evolution of mortality from ischaemic cardiopathy (IC) in Spain from 1951 to 1986, which is tending to stabilize in some age groups, and from cerebrovascular accidents (CVA), which is clearly declining, an attempt is made to relate these developments to the prevalence of the main risk factors (hypertension, cholesterol, tobacco) associated with IC and CVA. Certain advances, though of a limited number, have been made in recent years in the control of arterial hypertension in Spain, although campaigns on a national scale as in other countries have not been carried out. Regarding alimentary factors, there is an obvious increase in the consumption of food rich in proteins a…

Improved Skyrme forces for Hartree-Fock seniority calculations

1992

Abstract The relationship between Skyrme parameters and physical quantities in nuclear matter is discussed in detail and bounds for some parameters are derived. Improved density-dependent two-body Skyrme forces are obtained by a least-squares fit of all the parameters simultaneously to a large set of data, including nuclear matter, mass formula and Landau parameters, and data of finite nuclei. Special attention is paid to the pairing properties of the interaction. These forces are used to perform self-consistent calculations in spherical closed-shell nuclei and Ca open-shell isotopes, within the Hartree-Fock seniority method. Good agreement with experimental data is obtained.

High-performance liquid chromatographic determination of diuretics in urine by micellar liquid chromatography.

1992

The use of micellar liquid chromatography for the determination of diuretics in urine by direct injection of the sample into the chromatographic system is discussed. The retention of the urine matrix at the beginning of the chromatograms was observed for different sodium dodecyl sulphate (SDS) mobile phases. The eluent strengths of a hybrid SDS-methanol micellar mobile phase for several diuretics were compared and related to the stationary phase/water partition coefficient with a purely micellar mobile phase. The urine band was appreciably narrower with a mobile phase of 0.05 M SDS-5% methanol (v/v) at 50 degrees C (pH 6.9). With this mobile phase the determination of bendroflumethiazide an…

Theoretical spectroscopic parameters of the alkali monofluorides LiF, NaF and KF

1992

Abstract Multireference configuration interaction and second-order perturbation theory are used to determine accurate spectroscopic parameters for the ground state of the alkali monofluorides from LiF to KF. Systematic saturation of the spdf subspaces of the atomic basis sets for the electron affinity of fluorine and the ionization potential of the metals have been shown to be more efficient than for the approximate dissociation energies in the molecule. the calculated rotational and vibrational constants and transitions for the three systems show excellent agreement with the expeirmental data.

On the Derivatization of Drugs Using 1-Nitroso-2-naphthol, 4-aminoantipyrine and 2,6-Dihaloquinone Chlorimides

1992

Coupling of 1-nitroso-2-naphthol (1N2N), 4-aminoantipyrine (4-AAP), 2,6-dichloroquinone chlorimide (DCQC) and 2,6-dibromoquinone chlorimide (DBQC) with several bioactive substances, including adren...

The Carini Experimental Station for Wastewater Reuse in Agriculture – Preliminary Indications

1992

A two year experiment, to study the feasibility of wastewater reuse for a safe irrigation in the Sicilian context, has been initiated. Eight plots in two fields, totalling 629 m2, were planted with cowpeas (Vigna unguiculata L. Walp.), the irrigation water being supplied by a pilot plant treating 22 m3/day of municipal wastewater. The plant consists of an extended aeration biological system followed by rapid sand filtration and a choice of disinfection systems. Analyses performed on all waters used in the experiment indicate that safe irrigation water, virtually pathogen-free, can be produced if careful operational techniques are adopted. Despite all possible care, however, soil samples tak…

Rapid left ventricular filling in untreated hypertensive subjects with or without left ventricular hypertrophy

1992

In this study, independent contribution of age, HR, BMI, casual and ambulatory blood pressure, LVM and LVEF in evaluating diastolic filling have been investigated in 34 never-treated hypertensive patients and in 15 healthy normotensive subjects. All the subjects were free from coronary artery disease, valvular disease, heart failure, renal disease and psychiatric problems. All the hypertensive subjects (never treated) were subgrouped according to presence or absence of LVH. The PFR decreased significantly and tPFR increased significantly in hypertensive patients in comparison with normotensive subjects and they did not change in the presence vs absence of LVH. The PFR was inversely correlat…

The Psychopathy Checklist and non-violent offender groups

1992

Cleckley’s concept of psychopathy includes characteristics such as superficial charm, unreliability, and affective poverty. In this study, the Psychopathy Checklist (PCL) and personality questionnaires (MMPI, CPI, EPQ, and SSS) were used to assess 92 non-violent male offenders. The variable-based approach was applied in order to study the structure of the PCL and the relationships between the PCL, the PCL factors and the personality questionnaire scores. The results indicated that the personality scale scores failed to correlate positively with the PCL score, with the exception of the MMPI hypomania score. Two PCL factors emerged: factor 1 related to the core personality characteristics of …

Predominance of Th1-type T cells in synovial fluid of patients with Yersinia-induced reactive arthritis

1992

The pathogenetic mechanisms underlying the development of reactive arthritis and the functional capacities of synovial T cells specific for Yersinia enterocolitica are still unclear. In this study we have determined the cytokine secretion patterns of 24 CD4+ synovial fluid (SF)-derived T cell clones from 2 patients with Yersinia-induced reactive arthritis, 16 clones specific for different Yersinia antigens and 8 clones as controls. The clones specific for Yersinia antigens predominantly belong to the T helper cell 1 (Th1) subset with production of interferon (IFN)-gamma and interleukin (IL)-2, but no IL-4, whereas SF T cells not reactive with Yersinia antigens produce IL-2, IL-4 and IFN-gam…

Oxcarbazepine does not affect the anticoagulant activity of warfarin.

1992

The possible interaction of the antiepileptic drug oxcarbazepine (OCBZ) on the anticoagulant effect of warfarin was investigated in 10 healthy male volunteers. After reaching steady-state conditions by repeated administration of warfarin, the prothrombin time (Quick value) was assessed before and after single (600 mg) and multiple dosing (450 mg twice daily in 1 week) of OCBZ. In 7 of the 10 volunteers with evaluable data, the prothrombin time was not significantly different (paired t test) from baseline either after single (p = 0.299) or repeated dosing (p = 0.333), indicating that OCBZ does not interact to any relevant extent with the hypothrombinemic effect of warfarin.

Cytokine-mediated regulation of monocyte/macrophage cytotoxicity in human immunodeficiency virus-1 infection.

1992

Monocyte/macrophage-mediated tumor cytotoxicity was studied in patients infected with human immunodeficiency virus-1 (HIV-1) at various stages [Center for disease control (CDC) classification] of the disease. using the P-815 tumor cell line as target cells, the results demonstrated reduced monocyte/macrophage cytotoxicity early in HIV-1-related disease (CDCIII, P0.01). This cellular dysfunction sustained during the progression of the disease. Evidence could be presented that neither exogenous application of macrophage-stimulating cytokines (e.g. interferons) nor their endogenous induction in vitro restored monocyte/macrophage cytotoxicity. However, enhanced tumor necrosis factor (TNF)-alpha…

Positive inotropic response to 5-HT in human atrial but not in ventricular heart muscle

1992

The effects of 5-hydroxytryptamine (5-HT) on force of contraction (FC), action potential (AP) and calcium current (ICa) were studied in human right atrial and left ventricular heart muscle. 5-HT exerted a concentration-dependent increase in FC in multicellular atrial preparations; the EC50 was approximately 3 x 10(-7) mol/l. Maximal increases in FC (252 +/- 58% of control values; mean +/- SEM, n = 6) were obtained at 5-HT 10(-5) mol/l. At this concentration, ICa was increased four- to sevenfold in enzymatically isolated atrial myocytes. In contrast, ventricular preparations did not respond to 5-HT; FC, AP and ICa remained unaffected. In the same preparations, FC was increased by isoprenalin…

C-erbB-2-oncogene expression in breast carcinoma: Analysis by S1 nuclease protection assay and immunohistochemistry in relation to clinical parameters

1992

The c-erbB-2 mRNA was detected by the S1 nuclease protection assay and Northern blotting in breast cancer tissues. In contrast to the Northern blot analysis which has been used in all recent publications concerning c-erbB-2 expression on the level of RNA, the S1-nuclease protection assay has distinct advantages with respect to sensitivity, reproducibility, and handling of radioactive probes. We compared the expression of c-erbB-2 in 120 breast carcinomas which were operated in the years 1989-1990 on the level of the mRNA (S1 nuclease protection assay) and the protein (immunohistochemistry), respectively. In general, results obtained with both methods were in good agreement. Only minor diffe…

Shape coexistence in the A ∼ 70 region including neutron-proton interaction and unnatural-parity correlations in the mean field

1992

Abstract The recent investigations of the shape-coexistence phenomena dominating the structure of the even-even nuclei in the A ∼ 70 mass region are extended by introducing neutron-proton and unnatural-parity correlations in the mean field, while keeping the time-reversal invariance and the axial-symmetry restrictions. Selected low-lying states in 68Ge, 72Ge and 72Kr nuclei are investigated within the FED VAMPIR or EXCITED FED VAMPIR approaches. The results obtained using real and complex mean fields in a relatively large model space are compared with the experimental data. Similar qualitative features are obtained with both real and complex calculations concerning the evolution of the shap…

Collective Effects in Random Sequential Adsorption of Diffusing Hard Squares

1992

We study by Monte Carlo computer simulations random sequential adsorption (RSA) with diffusional relaxation, of lattice hard squares in two dimensions. While for RSA without diffusion the coverage approaches its maximum jamming value (large-time fractional coverage) exponentially, added diffusion allows the deposition process to proceed to the full coverage. The approach to the full coverage is consistent with the t**(-1/2) power law reminiscent of the equilibrium cluster coarsening in models with nonconserved order-parameter dynamics.

Excitation modes for fourier transform-ion cyclotron resonance mass spectrometry.

1992

AbstractVarious geometric configurations for the excitation of coherent ion motion in Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR/MS) are analyzed (in some cases for the first time) with unified notation. The instantaneous power absorption, F·v, in which v is ion velocity and F the force produced by the applied excitation electric field (harmonic, single frequency, on-resonance, in-phase), is time averaged and then set equal to the time rate of change of ion total (cyclotron + magnetron + trapping) energy, to yield a differential equation that is readily solved for the (time-dependent) amplitude of each of the various ion motions. The standard FT-ICR excitation (name…

NONCOMMUTATIVE GEOMETRY AND GRADED ALGEBRAS IN ELECTROWEAK INTERACTIONS

1992

The Standard Model of Electroweak Interactions can be described by a generalized Yang-Mills field incorporating both the usual gauge bosons and the Higgs fields. The graded derivative by means of which the Yang-Mills field strength is constructed involves both a differential acting on space-time and a differential acting on an associative graded algebra of matrices. The square of the curvature for the corresponding covariant derivative yields the bosonic Lagrangian of the Standard Model. We show how to recover the whole fermionic part of the Standard Model in this framework. Quarks and leptons fit naturally into the smallest typical and nontypical irreducible representations of the graded …

PION DOUBLE CHARGE EXCHANGE REACTIONS LEADING TO DOUBLE PIONIC ATOMS

1992

We study theoretically pion double charge exchange reactions leading to double pionic atoms. The reaction cross-sections with two pions in the deeper bound pionic orbits in 208Pb are calculated with realistic pionic atom wave functions and distortion effects. The cross-sections are found to be d2σ/dEdΩ~10−3−10−4 µ b/srMeV , which are only a small fraction of the double charge exchange background.

Suppression by cholinesterase inhibition of a Ca(2+)-independent efflux of [3H]acetylcholine from the neuromuscular junction of the isolated rat diap…

1992

Abstract Endplate preparations of the left rat hemidiaphragm were incubated with [ 3 H]choline to label neuronal acetylcholine stores. Elevation of the concentration (13.5–135 mmol/l) of extracellular potassium chloride (KC1) stimulated the release of [ 3 H]acetylcholine in a concentration-dependent manner. KC1 (27 mmol/l) still caused a significant efflux of [ 3 H]acetylcholine in a Ca 2+ -free medium. Inhibitors of cholinesterase (physostigmine, diisopropylfluorophosphate) suppressed by 80% this Ca 2+ -independent efflux of [ 3 H]acetylcholine. Vesamicol (10 μmol/l), the blocker of the vesicular acetylcholine carrier, also suppressed the stimulated, Ca 2+ -independent efflux of [ 3 H]acet…

Deep Levels in Silicon Doped n-Indium Selenide

1992

Neutron-scattering studies on CeM2Ge2(M=Ag, Au, and Ru)

1992

The results of elastic, quasielastic, and inelastic neutron-scattering studies on polycrystalline CeM 2 Ge 2 (M=Ag, Au, and Ru) are presented. All compounds reveal long-range magnetic order at low temperatures. Ferromagnetic (M=Ru), antiferromagnetic (M=Au), and incommensurate (M=Ag) structures were detected. Using time-of-flight (TOF) techniques, the crystalline electric-field splittings were determined. With high-resolution TOF experiments the temperature and wave-vector dependence of the magnetic relaxation rate was studied