Effect of omega-3 polyunsaturated fatty acids on activity of glutathione-dependent enzymes in the liver cytosol and blood erythrocytes in rats with experimental chronic bronchitis and in the norm

The influence of omega-3 polyunsaturated fatty acids (omega-3 PUFA) on the activity of glutathione reductase, glutathione transferase and glutathione peroxidase in the liver cytosole and red blood cells of normal rats and animals with experimental chronic bronchitis. omega-3 PUFA ("Tekom" medication) activate glutathione reductase of liver cytosole and glutathionperoxidase in the red blood cells in rats. In the rats with chronic inflammatory process in bronchia omega-3 PUFA corrects the glutathione-dependent systems of detoxication. Effects were more expressed in the liver cytosole in comparison with the red blood cells. The using of omega-3 PUFA as a means for treatment and prophylaxis was more effective than for treatment only.     

The morphology of <Emphasis Type="Italic">Laubieriopsis</Emphasis> sp. (Polychaeta,Fauveliopsidae) and the position of fauveliopsids in the polychaete system

The external and internal morphology of Laubieriopsis sp. from the North Sea was studied using light, scanning, and transmission microscopy. The morphology of the head end, parapodia, pigidium, body cavity, digestive tract, nervous system, and reproductive system was analyzed. The studied species was most similar to L. cabiochi (Amoreux, 1982) but displayed some significant differences. The body consists of 22 setigers (versus 21 setigers of L. cabiochi), bears bidentate modified aciculae in four anterior segments, and has paired genital papillae (unpaired in L. cabiochi) located on the eighth segment. Parapodia of the 5th–22nd segments bear one long capillary chaeta and one very short and thin chaeta in each ramus. The anterior part of the body capable of invaginating (forming an introvert) comprises only the prostomium and peristomium and does not include the first segment, as is typical of flabelligerids. The oral cavity contains well-developed dorsolateral ciliary folds. The ventral pharyngeal organ is undetectable. The ciliary folded esophagus is a straight tube without a loop even in an inverted head. The gut forms a small loop in the region of the 17th segment. The body cavity is divided by well-developed dissepiments and mesenteries, forming an intricate system of partitions in the anterior part of the body. The neuron bodies of the ventral nerve cord are homogenously distributed without forming distinct ganglia; however, the nerve cord forms two or three swellings in each segment. The position of fauveliopsids in the polychaete system is discussed. This study did not find any traits of fauveliopsids similar to Flabelligeridae and close taxa.     

Oxidation and removal of industrial textile dyes by a novel peroxidase extracted from post-harvest lentil (Lens culinaris L.) stubble

The degradation and removal of a series of dyes used in the textile industry for polyester/wool (PES/WO) blends and present in effluents, such as Green, Ash-Grey, Black, Navy Blue, Red and Yellow Domalan, and Orange and Red Bemacid, by catalytic action, in the presence of H₂O₂, of extracts of a novel peroxidase from postharvest lentil stubble was investigated. The extracts of this peroxidase (LSP) were effective in degrading these lastgeneration textile dyes, especially Green Domalan, Orange Bemacid, Grey and Black Domalan. A sensitivity study was carried out for Green Domalan biodegradation to determine the effects of process parameters such as pH, H₂O₂, enzyme and dye concentrations, contact and centrifugation times, and temperature. Standard ecotoxicity studies performed with Vibrio fischeri revealed that the dye solutions treated with peroxidase and H₂O₂ were less ecotoxic than the untreated ones.     

Role of calcium ions in response generation by the scallop abdominal sensory organ

The effect of calcium-free solution, cadmium ions, and theophylline on the global spike response in a nerve arising from the abdominal sensory organ of the scallopPatinopecten yessocensis, evoked by mechanical stimulation of that organ, was investigated. Removal of Ca ions from the external medium and addition of 10 mM CdCl₂ to it were shown to reversibly inhibit the combined spike response. Addition of theophylline to the external medium in a concentration of 5 mM caused an increase in amplitude of the spike response. These results indicate that Ca ions play a direct part in transformation of the mechanical stimulus into an electrical signal, and also that this process may be regulated by intracellular cAMP-dependent reactions.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Pacific Oceanologic Institute, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 16, No. 4, pp. 475–480, July–August, 1984.     

A novel method for preparation of HAMLET-like protein complexes

Some natural proteins induce tumor-selective apoptosis. α-Lactalbumin (α-LA), a milk calcium-binding protein, is converted into an antitumor form, called HAMLET/BAMLET, via partial unfolding and association with oleic acid (OA). Besides triggering multiple cell death mechanisms in tumor cells, HAMLET exhibits bactericidal activity against Streptococcus pneumoniae. The existing methods for preparation of active complexes of α-LA with OA employ neutral pH solutions, which greatly limit water solubility of OA. Therefore these methods suffer from low scalability and/or heterogeneity of the resulting α-LA - OA samples. In this study we present a novel method for preparation of α-LA - OA complexes using alkaline conditions that favor aqueous solubility of OA. The unbound OA is removed by precipitation under acidic conditions. The resulting sample, bLA-OA-45, bears 11 OA molecules and exhibits physico-chemical properties similar to those of BAMLET. Cytotoxic activities of bLA-OA-45 against human epidermoid larynx carcinoma and S. pneumoniae D39 cells are close to those of HAMLET. Treatment of S. pneumoniae with bLA-OA-45 or HAMLET induces depolarization and rupture of the membrane. The cells are markedly rescued from death upon pretreatment with an inhibitor of Ca²⁺ transport. Hence, the activation mechanisms of S. pneumoniae death are analogous for these two complexes. The developed express method for preparation of active α-LA - OA complex is high-throughput and suited for development of other protein complexes with low-molecular-weight amphiphilic substances possessing valuable cytotoxic properties.     

Multi-stage nature of the thermal denaturation process in collagen.

Thermal denaturation of acid-soluble collagen from polar cod (Eleginus gracialis) skin has been studied by scanning microcalorimetry and intrinsic spectrofluorimetry methods. The thermal denaturation process occurs in three independent stages reflecting the melting of 33 kDa, 97 kDa, and 230 kDa domains. Thermodynamical parameters of the collagen denaturation have been determined.     

Functional features of electroreceptors (small pit organs) in the catfish

Characteristics of responses of the small pit organs of the catfishIctalurus nebulosus to the action of electrical stimuli of varied polarity, intensity, and duration were studied. Single fibers of the lateral nerve innervating these organs possessed regular spontaneous activity with a frequency of 35–45/sec or grouped activity, coinciding with the rhythm of the animal's swimming movements. Threshold current densities varied from 10⁻¹¹ to 10⁻¹⁰ A/mm². Electrical stimuli evoked a phasic-tonic response of the receptor. The latent period was 10–50 msec for on-responses and 10–200 msec for off-responses. In the presence of strong electric fields the receptor responded to a cathodal stimulus by excitation, whereas under ordinary experimental conditions an anodal stimulus is excitatory. The properties of small pit organs are compared with the characteristics of other electroreceptors.     

Zinc-, cobalt- and iron-chelated forms of adenylate kinase from the Gram-negative bacterium Desulfovibrio gigas

Adenylate kinase (AK) from the sulphate-reducing bacterium Desulfovibrio gigas (AK) has been characterized earlier as a Co²⁺/Zn²⁺-containing enzyme, which is an unusual characteristic for adenylate kinases from Gram-negative bacteria, in which these enzymes are normally devoid of metal ions. AK was overexpressed in E. coli and homogeneous Co²⁺-, Zn²⁺- and Fe²⁺-forms of the enzyme were obtained under in vivo conditions. Their structural stability and spectroscopic and kinetic properties were compared. The thermal denaturation of Co²⁺- and Zn²⁺-forms of AK was studied as a cooperative two-state process, sufficiently reversible at pH 10, which can be correctly interpreted in terms of a simple two-state thermodynamic model. In contrast, the thermally induced denaturation of Fe²⁺-AK is irreversible and strongly dependent upon the scan rate, suggesting that this process is under kinetic control. Practically identical contents of secondary-structure elements were found for all the metal-chelated-forms of AK upon analysis of circular dichroism data, while their tertiary structures were significantly different. The peculiar tertiary structure of Fe²⁺-AK, in contrast to Co²⁺- and Zn²⁺-AK, and the consequent changes in the physico-chemical and enzymatic properties of the enzyme are discussed.     

Thermal stability of peroxidase from the african oil palm tree Elaeis guineensis.

The thermal stability of peroxidase from leaves of the African oil palm tree Elaeis guineensis (AOPTP) at pH 3.0 was studied by differential scanning calorimetry (DSC), intrinsic fluorescence, CD and enzymatic assays. The spectral parameters as monitored by ellipticity changes in the far-UV CD spectrum of the enzyme as well as the increase in tryptophan intensity emission upon heating, together with changes in enzymatic activity with temperature were seen to be good complements to the highly sensitive but integral method of DSC. The data obtained in this investigation show that thermal denaturation of palm peroxidase is an irreversible process, under kinetic control, that can be satisfactorily described by the two-state kinetic scheme, N -->(k) D, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation; N is the native state, and D is the denatured state. On the basis of this model, the parameters of the Arrhenius equation were calculated.     

Semper's (zoanthid) larvae: pelagic life,parentage and other problems

Semper's larvae were obtained from <300 out of 1800 plankton tows taken in the world's oceans (1964–1993). Zoanthellae (larvae of Sphenopidae) occurred at 217 stations and zoanthinae (larvae of Zoanthidae) at 86, the two larval types showing distributions clearly delimited by a minimum sea temperature (22 °C for zoanthellae, 18 °C for zoanthinae; a statistically significant difference, P<0.001). Length of formalin-fixed zoanthellae was 2–8.6 mm and of zoanthinae 1.5–5.9 mm. Endodermal zooxanthellae were present in 9/24 zoanthinae but in no zoanthellae (of 19). Three larvae contained an endo-commensal/parasitic amphipod. Septa were externally visible in larger zoanthinae and were counted in transverse sections of other larvae, a majority of which (both kinds) had 12 septa, the normal maximum. The pattern was brachycnemic in 40/43 larvae and anomalous (but non-macrocnemic) in three. If macrocnemic genera reproduce by Semper's larvae, they should have been represented in such a large sample. The distribution of adult Epizoanthus was examined: many species are deep sea (recorded down to 5000 m) but shallow-water species are relatively plentiful in, for example, the Adriatic and North Seas. No Semper's larva has ever been recorded from either. Some Parazoanthus species also occur in shallow water, especially associated with western Atlantic reef sponges. If they produce Semper's larvae, these have never been found. It is probable that macrocnemic zoanthids settle from planulae that do not develop into recognizable zoanthellae or zoanthinae.