Overview of mechanisms of action of lycopene

Dietary intakes of tomatoes and tomato products containing lycopene have been shown to be associated with decreased risk of chronic diseases such as cancer and cardiovascular diseases in numerous studies. Serum and tissue lycopene levels have also been inversely related to the risk of lung and prostate cancers. Lycopene functions as a very potent antioxidant, and this is clearly a major important mechanism of lycopene action. In this regard, lycopene can trap singlet oxygen and reduce mutagenesis in the Ames test. However, evidence is accumulating for other mechanisms as well. Lycopene at physiological concentrations can inhibit human cancer cell growth by interfering with growth factor receptor signaling and cell cycle progression specifically in prostate cancer cells without evidence of toxic effects or apoptosis of cells. Studies using human and animal cells have identified a gene, connexin 43, whose expression is upregulated by lycopene and which allows direct intercellular gap junctional communication (GJC). GJC is deficient in many human tumors and its restoration or upregulation is associated with decreased proliferation. The combination of low concentrations of lycopene with 1,25-dihydroxyvitamin D3 exhibits a synergistic effect on cell proliferation and differentiation and an additive effect on cell cycle progression in the HL-60 promyelocytic leukemia cell line, suggesting some interaction at a nuclear or subcellular level. The combination of lycopene and lutein synergistically interact as antioxidants, and this may relate to specific positioning of different carotenoids in membranes. This review will focus on the growing body of evidence that carotenoids have unexpected biologic effects in experimental systems, some of which may contribute to their cancer preventive properties in models of carcinogenesis. Consideration of solubility in vitro, comparison with doses achieved in humans by dietary means, interactions with other phytochemicals, and other potential mechanisms such as stimulation of xenobiotic metabolism, inhibition of cholesterogenesis, modulation of cyclooxygenase pathways, and inhibition of inflammation will be considered. This review will point out areas for future research where more evidence is needed on the effects of lycopene on the etiology of chronic disease.     

Shapes of curves of pH-dependence of reactions

A simple case is considered in which the rate of a two-step reaction depends on pH because the intermediate formed in the first step has to gain (or lose) a proton before it can react in the second step, and in which the rate-determining step therefore changes with pH. The curves of reaction rate against pH are shown to be symmetrical, and the sharpest peak possible has a width at half its height of 1.53pH units, i.e. of 2log(3+2 radical2). Any particular curve for this situation proves to be identical with a curve that could be generated for the pH-dependence of a single-step reaction in which the rate is proportional to the concentration of a particular ionic form of a reactant. Curves for the latter situation, however, can have forms impossible for the former case in which the rate-determining step changes, but only if the protonations that activate and deactivate the reactant are co-operative. The peak can then become even sharper, and its width at half its height can fall to 1.14pH units, i.e. to 2log(2+ radical3).     

Comparative characteristics of the ichthyoplankton of lagoon lakes of the south-eastern part of Sakhalin

Ichthyoplankton surveys are made in lagoon water bodies of the south-eastern part of Sakhalin (the Vavai-Chibisan system of lakes, Lake Tunaicha, Lake Izmenchivoe) from April until November 2002–2007. Comparative characteristics of ichthyoplankton complexes in the ice-free period is given. In the investigated lagoon lakes, differences in the species composition of the ichthyoplankton by the number and time of appearance of the maxima of abundance of eggs and larvae are noted, and also related to morphological structure and hydrological conditions of water bodies. In lagoon lake Izmenchivoe with a salinity not less than 26‰, the eggs and larvae of marine fishes only takes place while, in Vavai-Chibisan lakes, that of freshwater fishes only takes place. In brackish lake Tunaicha, the lowest number of fish species reproduce. In the Vavai-Chibisan system and in Lake Izmenchivoe, one maximum of abundance of ichthyoplankton in June is recorded and, in Lake Tunaicha, two maxima (the highest in June and less expressed in August) are recorded. Irrespective of the species composition, the ichthyoplankton complexes of lagoon lakes have general traits determined by hydrological conditions of water bodies and by their general origin and geographic situation: prevalence of eggs and larvae of low boreal fish species, the maximum species diversity in the late spring-early summer, and decrease of abundance in cooler years.     

Effect of conditioning polarization of soma of giant neurons of mollusks on the mechanism of action-potential generation

To ascertain the properties of an excitable membrane of the soma of giant neurons of mollusks, experiments were carried out to study the effect of conditioning shift of the membrane potential on the mechanism of action-potential generation. The effect of conditioning was assessed from changes in the action-potential curve and its first derivative, as well as from the curve of transmembrane currents under voltage clamp conditions. It was found that a change in membrane potential evokes at least two reactions which have opposite effects on the mechanism of generation of action potentials. These reactions evidently have different time characteristics. One of these does not differ notably from the reaction recorded for other excitable structures, and is manifested in the activation (with hyperpolarization) or inactivation (with depolarization) of the mechanism generating action potentials. The other reaction contributes either to an increase (with depolarization) or a decrease (with hyperpolarization) in the efficiency of this mechanism. Conditioning polarization also has a marked effect on the system responsible for repolarization of the membrane during generation of action potentials. This effect is manifested in a change in the reaction of this system to tetraethylammonium ions. The specific membrane systems sustaining excitability and reacting to changes in the strength of the membrane's electrical field were found to be very inert. After a shift in the potential to a given stable level a rearrangement, lasting sometimes tens of seconds, takes place in the membrane.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 2, No. 1, pp. 91–99, January–February, 1970.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

Correction of distortion of histologic sections of arteries

Histologic sections of arteries can be used to generate three-dimensional (3D) geometric models and identify structural constituents. However, geometric distortions are introduced by fixation, embedding and sectioning; distortions which can, for example, lead to errors in stresses predicted by finite element models. We developed a method to measure and correct for distortions caused by acrylic processing and applied it to intact, healthy porcine coronary arteries. Micro-computed tomography was used to image arteries in the fresh and embedded states. Tissue blocks were sectioned, stained and imaged using a light microscope. Each section contained four registration marks used to determine strains introduced by sectioning and staining. Using these three image sets, 3D geometric models were generated and distortions were measured. Fixation, processing, and embedding resulted in shrinkage of 6.4+/-2.3% axially and 35.4+/-5.0% in mean cross-sectional area (n=5). Shrinkage in a cross section was well characterized by a uniform, equibiaxial strain. Sectioning and staining resulted in additional compressive strains in the sectioning direction of 0.067+/-0.011 and, in the direction perpendicular to sectioning, of 0.023+/-0.005 (n=5). These strains are assumed uniform and form the basis for correcting section geometry. Reconstructions using corrections for sectioning and shrinkage-related distortions had errors of 1.6+/-0.5% (n=5) and 4.0+/-1.7% (n=5), respectively.     

Some causes of the variable shape of flocks of birds

Flocks of birds are highly variable in shape in all contexts (while travelling, avoiding predation, wheeling above the roost). Particularly amazing in this respect are the aerial displays of huge flocks of starlings (Sturnus vulgaris) above the sleeping site at dawn. The causes of this variability are hardly known, however. Here we hypothesise that variability of shape increases when there are larger local differences in movement behaviour in the flock. We investigate this hypothesis with the help of a model of the self-organisation of travelling groups, called StarDisplay, since such a model has also increased our understanding of what causes the oblong shape of schools of fish. The flocking patterns in the model prove to resemble those of real birds, in particular of starlings and rock doves. As to shape, we measure the relative proportions of the flock in several ways, which either depend on the direction of movement or do not. We confirm that flock shape is usually more variable when local differences in movement in the flock are larger. This happens when a) flock size is larger, b) interacting partners are fewer, c) the flock turnings are stronger, and d) individuals roll into the turn. In contrast to our expectations, when variability of speed in the flock is higher, flock shape and the positions of members in the flock are more static. We explain this and indicate the adaptive value of low variability of speed and spatial restriction of interaction and develop testable hypotheses.     

Histochemical studies of monoamine oxidase of the brain of rodents

Summary MAO of the brain was investigated histochemically in mice, rats, guinea pigs and rabbits. Fresh frozen sections were subjected to the tryptamine-tetrazolium method by Glenner, Burtner and Brown (1957).MAO activity of the brain of 4 animal species is generally similar with respect to its pattern of distribution. However, the intensity of enzyme action of the brain as a whole differs somewhat in animal species, being highest in guinea pigs, intermediate in rats and lowest in mice and rabbits. The enzyme action occurs mainly in the neuropil of the cerebral grey matter, while weak or negative activity is generally observed in the white matter excepting the tractus retroflexus of Meynert.The marked activity is encountered in the interpeduncular nucleus, locus coeruleus, area postrema, dorsal nucleus of the vagus nerve, hypothalamus, habenular nuclei and midline nuclear group of the thalamus, nucleus of the brachium conjunctivum, and central grey matter. The enzyme activity is weak or negative in the neocortex, striatum, mamillary body, thalamic nuclei (excepting the habenula and midline nuclear group), subthalamic nucleus, substantia nigra, red nucleus and nuclei of the somatic cranial nerves.The possible function and significance of MAO in the brain were discussed particularly by comparing the sites of this enzyme with those of succinic dehydrogenase and cytochrome oxidase, and the inverse relation between these enzymes was suggested.     

湖南省实验动物中几种常见的人兽共患病监测

目的对2003年至2007年湖南省实验动物中沙门氏菌、汉坦病毒、仙台病毒、淋巴细胞脉络丛脑膜炎病毒、弓形虫病等几种常见的人兽共患病的流行病学进行调查。方法按《GB14922．2-2001》和《GB14922．1-2001》抽检动物。结果实验大、小鼠汉坦病毒（HV）和仙台病毒（Sendai）出现抗体阳性,实验小鼠淋巴细胞脉络丛脑膜炎病毒（LCM）出现抗体阳性,实验鼠沙门氏菌（Salmonella）检测结果阳性,实验大鼠和普通级兔弓形体（Toxoplasma）检测结果阳性。结论应加强对实验动物流行病学的监测。     

青蒿素生物合成机理研究现状

本文总结了目前有关青蒿素生物合成机理方面的研究,主要包括青蒿素生物合成中生理因子的影响,青蒿素生物合成中间体及前体,青蒿素生物合成细胞定位等。指出了存在的一些问题及今后的研究发展前景。     

Mode of Operation of Ampullae of Lorenzini of the Skate, Raja

Ampullae of Lorenzini are sensitive electroreceptors. Applied potentials affect receptor cells which transmit synaptically to afferent fibers. Cathodal stimuli in the ampullary lumen sometimes evoke all-or-none "receptor spikes," which are negative-going recorded in the lumen, but more frequently they evoke graded damped oscillations. Cathodal stimuli evoke nerve discharge, usually at stimulus strengths subthreshold for obvious receptor oscillations or spikes. Anodal stimuli decrease any ongoing spontaneous nerve activity. Cathodal stimuli evoke long-lasting depolarizations (generator or postsynaptic potentials) in afferent fibers. Superimposed antidromic spikes are reduced in amplitude, suggesting that the postsynaptic potentials are generated similarly to other excitatory postsynaptic potentials. Anodal stimuli evoke hyperpolarizations of nerves in preparations with tonic activity and in occasional silent preparations; presumably tonic release of excitatory transmitter is decreased. These data are explicable as follows: lumenal faces of receptor cells are tonically (but asynchronously) active generating depolarizing responses. Cathodal stimuli increase this activity, thereby leading to increased depolarization of and increased release of transmitter from serosal faces, which are inexcitable. Anodal stimuli act oppositely. Receptor spikes result from synchronized receptor cell activity. Since cathodal stimuli act directly to hyperpolarize serosal faces, strong cathodal stimuli overcome depolarizing effects of lumenal face activity and are inhibitory. Conversely, strong anodal stimuli depolarize serosal faces, thereby causing release of transmitter, and are excitatory. These properties explain several anomalous features of responses of ampullae of Lorenzini.     

Study of the Mode of Action of Some Nitrodiphenyl Ethers

Nitrosoderivatives of the nitrodiphenyl ether herbicides (nitrofen, bifenox) have been studied. UV irradiation in different organic solvents gives degradation products. In buffered aqueous media, in the presence of chloroplasts and spin traps such as DMPO, hydroxy and peroxy radicals have been characterized.

In organic media and in the presence of spin traps such as DMPO, PBN, 4-POBN, solvent radicals (CHCIl₂, CCI₃, CH₂O) have been formed.

Nitro-derivatives have been studied under UV irradiation and in the presence of tetramethylethylene (TME), alkenylhydroxylamines are formed which autoxidize in nitroxide radicals. The formation of the stable nitroxide radical occurs in the dark process after continuous irradiation. The intensity of the signal decreases strongly when a new irradiation is applied. Radical species, with analogous ESR spectral characteristics are formed on reaction with nitrodiphenyl ethers and fatty acids.

The reactivity of these herbicides in micellar media (SDS, Brij 35, and CTAB) has been investigated. The kinetics of formation of the ESR signal corresponding to the photoreduction of the nitrodiphenyl ether in the presence of TME behave differently in a micellar environment as compared to solution. The intensity of the formation of the nitroxide increases under irradiation and decreases in the dark; the rotational correlation time t_c has been determined for each type of micelle.

Synthetic nitrosodiphenyl ether made by the reduction of nitrodiphenyl ether using hydrogen gas and PtO₂ as a catalyst gives the corresponding amine, which is oxidized with rneta-chloroperbenzoic acid (m.CPBA). The nitrosodiphenyl ether in the presence of soja azolectin liposorne containing a fluorescent probe has been analysed. When this synthetic nitrosodiphenyl ether is added to a medium containing soja azolectin liposomes and a carboxyfluorescein, fluorescent probe placed inside the liposornes, a rapid increase in the fluorescence of the medium is observed. The nitrosodiphenyl ether induce a break in the liposorne membrane.     

Determination of stoichiometry of radioiodination of proteins

A sensitive method for the detection of small quantities of hydrophobic antioxidant free radical scavengers such as butylatedhydroxytoluene (BHT) and butylatedhydroxyanisole (BHA) in aqueous samples is described. The procedure involves extraction of the hydrophobic free radical scavenger into an organic solvent phase, followed by the subsequent reaction of an aliquot of this extract with the stable cation radical tris(p-bromophenyl)amminium hexachloroantimonate (TBACA). In experiments with BHT and BHA, the loss of TBACA absorbance at 730 nm was found to be linearly proportional to the amount of antioxidant added, with quantities of BHT as small as 200 pmol being easily detectable. In aqueous suspensions of dimyristoylphosphatidylcholine vesicles, assays of the aqueous BHT concentration showed that BHT partitioned strongly into the membrane phase, achieving very high BHT/phospholipid ratios. For a given concentration of BHT, partitioning into the membrane phase was greater in large, multilamellar liposomes than in either small, single-walled vesicles or in purified rat brain synaptic vesicle membranes. Direct assay of BHT and BHA in phospholipid membranes, however, was complicated by a nonspecific interaction between TBACA and the phospholipid.     

Comparative study of genomes of two species of flax by C-banding of chromosomes

C-banding patterns of the karyotypes of two closely related wild flax species, Linum austriacum L. (2n = 18) and Linum grandiflorum Desf. (2n = 16), were studied. The karyotypes of both species were similar in the chromosome morphology and size. In each species, metacentric and acrocentric chromosomes (1.7-4.3 microns) and one satellite chromosome were observed. In the karyotypes of the species studied, all homologous chromosome pairs were identified, and quantitative ideograms were constructed. Eight chromosome pairs in the two species had similar C-banding patterns. A low level of intraspecific polymorphism in the intercalary and telomeric C-bands was shown in both species. The results indicate that the genomes of two flax species originated from one ancestral genome with the main chromosome number of 8 or 9. Apparently, the doubling of chromosome number or loss of one chromosome with subsequent redistribution of the chromosome material in the ancestral form resulted in the divergence into two species, L. austriacum L. and L. grandiflorum Desf. A considerable similarity of chromosomes in these species provides evidence for their close phylogenetic relatedness, which makes it possible to place them in one section within the Linum genus.     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Peculiarities of urea distribution in tissues of rats of different age

The content of urea was studied in protein-free filtrates of the liver kidneys, skeletal muscles, myocardium, spleen, brain tissues and blood serum as well as in urine of 1, 3, 6, 12 and 24-month rats. It is shown that at the age of 6 months the content of urine in most tissues under study is significantly decreased (by 42-73%), at the age of 12 months in the spleen and at the age of 24 months in the brain tissues as compared to the one-month animals. The level of urine decrease in the liver and brain tissues of 24-month animals is less pronounced than in other tissues, that corresponds to age peculiarities of their protein metabolism. A decrease of blood consumption per weight unit and a relative increase in the amount of nitrogen excreted with urine are observed with ageing. The arginase activity in the liver decreases essentially only in 3-month animals. A conclusion is drawn that peculiarities of food consumption and the character of changes in the urea content in tissues and urine are adaptation manifestation of an age decrease in the intensity of nitrogen metabolism and protein demand of the organism.     

肠道菌群分析及粪便炎性标志物检测在 炎症性肠病活动度评估中的作用

目的探讨肠道菌群和粪便炎性标志物在炎症性肠病(IBD)活动度评估中的临床价值。方法共纳入120例IBD患者为研究组,其中溃疡性结肠炎(UC)患者68例,克罗恩病(CD)患者52例。选择30例经结肠镜检查正常的健康体检者为对照组。采集全部研究对象的新鲜粪便标本进行粪便细菌培养及炎性标志物检测,比较不同疾病活动度IBD患者的肠道菌群及粪便钙卫蛋白(FC)、乳铁蛋白(LF)、基质金属蛋白酶-9(MMP-9)、髓过氧化酶(MPO)水平的变化。结果与对照组比,UC和CD患者肠道中肠杆菌、肠球菌、拟杆菌、消化球菌及酵母菌数量均明显增加(P0.05),双歧杆菌、乳杆菌及真杆菌数量明显减少(P0.05)。UC患者梭菌数量较对照组增加(P0.05),CD患者梭菌数量较对照组减少(P0.05)。UC、CD活动期患者肠杆菌、肠球菌、拟杆菌、消化球菌及酵母菌数量明显多于缓解期患者(P0.05),双歧杆菌、乳杆菌及真杆菌数量明显少于缓解期患者(P0.05),且重度活动期患者肠道菌群改变较轻、中度活动期改变更明显(P0.05)。UC活动期患者梭菌数量明显多于缓解期(P0.05),CD活动期患者梭菌数量明显少于缓解期(P0.05)。UC和CD患者粪便中FC、LF、MMP-9及MPO水平均显著高于对照组(P0.05)。UC、CD活动期患者FC、LF、MMP-9及MPO水平显著高于缓解期患者(P0.05),且重度活动期患者高于轻、中度活动期患者(P0.05)。结论肠道菌群变化和粪便中FC、LF、MMP-9及MPO水平可作为IBD患者疾病活动性评估的辅助指标。     

Length of polymorphisms of restriction fragments of rat mitochondrial DNAs

Differences were found in the HpaII cleavage patterns of two types of rat (Rattus norvegicus) mtDNA, types A and B. One HpaII fragment, Hpa5, of type A was about 30 base pairs smaller than that of type B, but no 30-base pair fragment was detectable in an HpaII digest of type A mtDNA. Moreover, one HaeIII fragment, which is overlapped by Hpa5 in the cleavage map, was also about 30-base pairs smaller in type A than in type B. Thus, the length polymorphism of Hpa5 in the two types is probably not caused by HpaII site gain or loss, but by sequence deletion or insertion.