Toxicological characteristics of ampicillin]

Toxocity of ampicillin trihydrate was studied in acute and chronic experiments. It was shown that the antibiotic had low acute toxicity, did not cumulate and had no skin-irritating effect. On its inhalation in concentrations of 5 mg/m3 for 4 months, ampicillin induced allergization of albino rats, decreased their immunity. The general toxic effect of the drug was slightly pronounced. Ampicillin in a concentration of 0.1 mg/m3 induced tension of the immunological reactivity of the organism. The maximum permissible concentration (MPC) of ampicillin in the working premises equal to 0.1 mg/m3 is recommended. Mark "Allergen" is necessary.     

Lipidomic Analysis of α-Synuclein Neurotoxicity Identifies Stearoyl CoA Desaturase as a Target for Parkinson Treatment

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Size exclusion chromatography on soft and semi-rigid packing materials in the dynamic axial compression mode

The effect of dynamic axial compression within a range of up to 5 bar upon the structure of the bed packed with soft and semi-rigid packing materials (Sephadex G-25, Bio-Gel P2 and Toyopearl HW-40) and the associated chromatographic parameters were studied for size exclusion chromatography. Continuous packing compression is accomplished by use of a special column with controlled external pressure applied to the packing. Compression has been shown to favor an overall increase in the resolution with pressure optima observed in some cases.     

Biodegradation of methyl parathion and <Emphasis Type="Italic">p</Emphasis>-nitrophenol: evidence for the presence of a <Emphasis Type="Italic">p</Emphasis>-nitrophenol 2-hydroxylase in a Gram-negative <Emphasis Type="Italic">Serratia</Emphasis> sp. strain DS001

A soil bacterium capable of utilizing methyl parathion as sole carbon and energy source was isolated by selective enrichment on minimal medium containing methyl parathion. The strain was identified as belonging to the genus Serratia based on a phylogram constructed using the complete sequence of the 16S rRNA. Serratia sp. strain DS001 utilized methyl parathion, p-nitrophenol, 4-nitrocatechol, and 1,2,4-benzenetriol as sole carbon and energy sources but could not grow using hydroquinone as a source of carbon. p-Nitrophenol and dimethylthiophosphoric acid were found to be the major degradation products of methyl parathion. Growth on p-nitrophenol led to release of stoichiometric amounts of nitrite and to the formation of 4-nitrocatechol and benzenetriol. When these catabolic intermediates of p-nitrophenol were added to resting cells of Serratia sp. strain DS001 oxygen consumption was detected whereas no oxygen consumption was apparent when hydroquinone was added to the resting cells suggesting that it is not part of the p-nitrophenol degradation pathway. Key enzymes involved in degradation of methyl parathion and in conversion of p-nitrophenol to 4-nitrocatechol, namely parathion hydrolase and p-nitrophenol hydroxylase component “A” were detected in the proteomes of the methyl parathion and p-nitrophenol grown cultures, respectively. These studies report for the first time the existence of a p-nitrophenol hydroxylase component “A”, typically found in Gram-positive bacteria, in a Gram-negative strain of the genus Serratia. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

A new species of <Emphasis Type="Italic">Pterothominx</Emphasis> Freitas, 1959 (Nematoda: Capillariidae) parasitising psittacine birds (Psittaciformes)

A new species, Pterothominx (Pterothominx) moraveci n. sp. (Trichinelloidea: Capillariidae) is described from an Australian parrot, Barnardius zonarius Shaw (Psittacidae: Psittaciformes), imported from Germany and kept in captivity in the Czech Republic. Males of the new taxon differ from all other species of the subgenus Pterothominx Freitas, 1959, which mainly parasitise galliform birds, in having a shorter spicule (0.925–1.338; mean 1.050 mm), a shorter body length and a different form of armed spicular sheath and bursa. Females differ in having the smallest eggs (40–50 × 20–25; mean 48 × 23 μm) and in other morphometrical characters. From the species P. (P.) totani (Linstow, 1875), which parasitises charadriiform birds, the new species differs in its smaller number of stichocytes (females 42–46, mean 44; versus 50–54), different form of the bursa and praebursal alae, and other characters. This is the only species of Pterothominx that parasitises psittacine birds.     

Pressure monitoring of continuous-flow solid-phase peptide synthesis.

We describe the noninvasive real-time pressure monitoring of Boc- and Fmoc-based peptide synthesis. Pressure was measured using a resistance strain gauge attached to the inlet of a continuous-flow reactor of variable volume. In the assembly of the 'difficult' polyalanine sequence, it was shown that pressure monitoring can reveal structural variations of the peptide-resin, e.g. the onset, development and termination of aggregation. This method provided washing minimization that favored substantial saving of solvents. The obtained results demonstrated the advantage of pressure monitoring over swellographic monitoring.     

High stability of the hinge region in the membrane-active peptide helix of zervamicin: paramagnetic relaxation enhancement studies

Zervamicin IIB is a 16 amino acid peptaibol that forms voltage dependent ion channels with multilevel conductance states in planar lipid bilayers and vesicular systems. Stability of the hinge region and intermolecular interactions were investigated in the N- and C-terminally spin-labelled peptide analogues. Intermolecular and intramolecular paramagnetic enhancement indicates that zervamicin behaves as a rigid helical rod in methanol solution. There are no high amplitude hinge-bending motions, and the peptaibol is monomeric up to concentration 1.5 mM. Stability of the hinge region illustrates the helix stabilising propensity of the Pro residue in membrane mimic environments and implies absence of significant conformational rearrangement due to voltage peptaibol activation.     

The first species of Thelastoma Leidy, 1849 (Nematoda: Thelastomatidae) parasitising the scorpion Euscorpius italicus (Chactidae: Scorpionidea)

A new species, Thelastoma euscorpii, (Thelastomatidae: Oxyuroidea) is described from Euscorpius italicus (Chactidae) on Pag Island (Kvarner Islands), Croatia. The new taxon differs from all other species of Thelastoma in having a cuticle with fine transverse striae. The excretory pore of the female specimens is located in a prebulbar position, the tail is short and subfiliform (5.5-9.3% of the total body length), and the eggs are small (47-52×24-29 m). The males have a short oesophagus and no spicules. This is the first nematode species found in scorpions (Scorpionidea).