The influence of antioxidants and cycloheximide on the level of nitric oxide in the livers of mice in vivo

AbstractWhen injected into mice prior to the NO generation increase induced with lipopolysaccharide (LPS) from Escherichia coli, exogenous antioxidants diethyldithiocarbamate (DETC) or phenazan (sodium 3.5-di-tert-butyl-4-oxiphenylpropionate) as well as the inhibitor of protein biosynthesis, cycloheximide (CHI) attenuated the NO production in mouse liver in vivo. These data demonstrated the key role of free radicals, which were likely, active oxygen species, in the synthesis of inducible NO-synthase (iNOS) responsible for the NO production in this organ. Similar effects of phenazan and CHI were observed in livers of mice treated with γ-irradiation or LPS + Fe2+-citrate, which suggested that these treatments also induced 1NOS synthesis through initiating the action of active oxygen species. The rate of NO synthesis was estimated by accumulation of paramagnetic mononitrosyl iron complexes with DETC (MNIC-DETC) detected using the EPR method. The formation of MNIC-DETC complexes was found in the brain of mice pre-treated with LPS + Fe2+-citrate which seemed to be due to iNOS synthesis stimulated by this treatment

A setup for integral measurements of multiple scattering angular distributions by 10- to 100-keV electrons

A dedicated setup has been developed to study the angular distributions of electrons traversing thin films employing the low-energy beam available from the gun of the São Paulo Microtron. In this first stage, only integral measurements are possible using the fraction of the electron beam current collected in a Faraday cup and in a ring surrounding the entrance of the former. The overall normalisation is provided by measuring the beam current collected by the scattering chamber as well, thus covering the full solid angle. In this work, important construction specifications are presented. The experience gained by operating this system is also discussed regarding its critical aspects like: avoiding cross talk between the cup and the ring both at the physical and electronic levels, measurements of small charges deposited on large objects (the chamber in particular), and conditioning of the various surfaces involved. Finally, some selected results are compared to the well-known theory by Goudsmit and Saunderson with good agreement

The transcriptional repressor protein NsrR senses nitric oxide directly via a [2Fe-2S] cluster

The regulatory protein NsrR, a member of the Rrf2 family of transcription repressors, is specifically dedicated to sensing nitric oxide (NO) in a variety of pathogenic and non-pathogenic bacteria. It has been proposed that NO directly modulates NsrR activity by interacting with a predicted [Fe-S] cluster in the NsrR protein, but no experimental evidence has been published to support this hypothesis. Here we report the purification of NsrR from the obligate aerobe Streptomyces coelicolor. We demonstrate using UV-visible, near UV CD and EPR spectroscopy that the protein contains an NO-sensitive [2Fe-2S] cluster when purified from E. coli. Upon exposure of NsrR to NO, the cluster is nitrosylated, which results in the loss of DNA binding activity as detected by bandshift assays. Removal of the [2Fe-2S] cluster to generate apo-NsrR also resulted in loss of DNA binding activity. This is the first demonstration that NsrR contains an NO-sensitive [2Fe-2S] cluster that is required for DNA binding activity

European Council of Legal Medicine (ECLM) on-site inspection forms for forensic pathology, anthropology, odontology, genetics, entomology and toxicology for forensic and medico-legal scene and corpse investigation: the Parma form

Further to a previous publication by the European Council of Legal Medicine (ECLM) concerning on-site forensic and medico-legal scene and corpse investigation, this publication provides guidance for forensic medical specialists, pathologists and, where present, coroners’ activity at a scene of death inspection and to harmonize the procedures for a correct search, detection, collection, sampling and storage of all elements which may be useful as evidence, and ensure documentation of all these steps. This ECLM’s inspection form provides a checklist to be used on-site for the investigation of a corpse present at a crime or suspicious death scene. It permits the collection of all relevant data not only for the pathologist, but also for forensic anthropologists, odontologists, geneticists, entomologists and toxicologists, thus supporting a collaborative work approach. Detailed instructions for the completion of forms are provided

Direct EPR Detection of Nitric Oxide in Mice Infected with the Pathogenic Mycobacterium Mycobacterium tuberculosis

It has been shown that treatment of mice preinfected with Mycobacterium tuberculosis with spin NO traps (iron complexes with diethyldithiocarbamate) enables detection of large amounts of NO in internal organs 2 and 4 weeks after infection (up to 55–57 μmol/kg of wet lung tissue accumulated with spin NO traps during 30 min). The animals were infected with the drug-sensitive laboratory strain H37Rv and a clinical isolate nonrespondent to antituberculous drugs (the multidrug-resistant strain of M. tuberculosis) obtained from a patient with an active form of tuberculosis. Two weeks after infection with the multidrug-resistant strain, the NO level in the lungs, spleen, liver and kidney increased sharply concurrently with slight lesions of lung tissue. A reverse correlation, i.e., low level of NO in the lungs and other internal organs and extensive injury of lung tissue, was established for H37Rv-infected mice. Four weeks after infection, NO production in the lungs increased dramatically for both M. tuberculosis strains resulting in 80–84% damage of lung tissue. The lesion is suggested to be due to the development of defense mechanisms in M. tuberculosis counteracting NO effects

Quantum Entanglement in Nitrosyl Iron Complexes

Recent magnetic susceptibility measurements for polycrystalline samples of binuclear nitrosyl iron complexes [Fe_2(C_3H_3N_2S)_2(NO)_4] (I) and [Fe_2(SC_3H_5N_2)_2(NO)_4] (II), suggest that quantum-mechanical entanglement of the spin degrees of freedom exists in these compounds. Entanglement E exists below the temperature T_E that we have estimated for complexes I and II to be 80-90 and 110-120 K, respectively. Using an expression of entanglement in terms of magnetic susceptibility for a Heisenberg dimer, we find the temperature dependence of the entanglement for complex II. Having arisen at the temperature T_E, the entanglement increases monotonically with decreasing temperature and reaches 90-95% in this complex at T=25 K, when the subordinate effects are still small.Comment: 8 page

Drosophila circadian rhythms in semi-natural environments; the summer afternoon component is not an artifact and requires TrpA1 channels

Under standard laboratory conditions of rectangular light/dark cycles and constant warm temperature, Drosophila melanogaster show bursts of morning (M) and evening (E) locomotor activity and a “siesta” in the middle of the day. These M and E components have been critical for developing the neuronal dual oscillator model in which clock gene expression in key cells generates the circadian phenotype. However, under natural European summer conditions of cycling temperature and light intensity, an additional prominent afternoon (A) component that replaces the siesta is observed. This component has been described as an “artifact” of the TriKinetics locomotor monitoring system that is used by many circadian laboratories world wide. Using video recordings, we show that the A component is not an artifact, neither in the glass tubes used in TriKinetics monitors nor in open-field arenas. By studying various mutants in the visual and peripheral and internal thermo-sensitive pathways, we reveal that the M component is predominantly dependent on visual input, whereas the A component requires the internal thermo-sensitive channel transient receptor potential A1 (TrpA1). Knockdown of TrpA1 in different neuronal groups reveals that the reported expression of TrpA1 in clock neurons is unlikely to be involved in generating the summer locomotor profile, suggesting that other TrpA1 neurons are responsible for the A component. Studies of circadian rhythms under seminatural conditions therefore provide additional insights into the molecular basis of circadian entrainment that would otherwise be lost under the usual standard laboratory protocols

Почечная гемодинамика у больных с хроническими диффузными заболеваниями печени

Statistically confident (р < 0,05) change of blood flow parameters in segmentary and parenchymal arteries in the form of increase of resistance and pulsativity indices has been found that in patients with high-activity chronic hepatite with hyperbilirubinemia. The highest increase of the resistance and pulsativity indices of 0,88 ± 0,05 and 1,24 ± 0,07, respectively, was observed only in segmentary arteries. No statistically confident (р > 0,05) changes were found in maximal and minimal linear parameters of blood flow in these arteries.Установлено, что у больных хроническими гепатитами высокой активности с гипербилирубинемией отмечается статистически достоверное (р < 0,05) изменение параметров кровотока в сегментарных и паренхиматозных артериях в виде повышения значений индексов резистентности и пульсативности. Наибольшее повышение индексов резистентности и пульсативности выявлено только в сегментарных артериях и составляет 0,88 ± 0,05 и 1,24 ± 0,07 соответственно. При этом статистически достоверных (р > 0,05) изменений максимальной и минимальной линейных скоростей кровотока в вышеперечисленных артериях не отмечено