Voltage-gated sodium channels potentiate the invasive capacities of human non-small-cell lung cancer cell lines

Ionic channel activity is involved in fundamental cellular behaviour and participates in cancerous features such as proliferation, migration and invasion which in turn contribute to the metastatic process. In this study, we investigated the expression and role of voltage-gated sodium channels in non-small-cell lung cancer cell lines. Functional voltage-gated sodium channels expression was investigated in normal and non-small-cell lung cancer cell lines. The measurement, in patch-clamp conditions, of tetrodotoxin-inhibitable sodium currents indicated that the strongly metastatic cancerous cell lines H23, H460 and Calu-1 possess functional sodium channels while normal and weakly metastatic cell lines do not. While all the cell lines expressed mRNA for numerous sodium channel isoforms, only H23, H460 and Calu-1 cells had a 250 kDa protein corresponding to the functional channel. The other cell lines also had another protein of 230 kDa which is not addressed to the membrane and might act as a dominant negative isoform to prevent channel activation. At the membrane potential of these cells, channels are partially open. This leads to a continuous entry of sodium, disrupting sodium homeostasis and down-stream signaling pathways. Inhibition of the channels by tetrodotoxin was responsible for a 40-50% reduction of in vitro invasion. These experiments suggest that the functional expression of voltage-gated sodium channels might be an integral component of the metastatic process in non-small-cell lung cancer cells probably through its involvement in the regulation of intracellular sodium homeostasis. These channels could serve both as novel markers of the metastatic phenotype and as potential new therapeutic targets.     

Prosimian sensory capacities

This paper reviews laboratory research on sensory capacities of prosimians. Most investigations to date have concentrated on visual and auditory sensitivity with relatively little attention directed toward olfactory and gustatory sensitivity. Diurnal prosimians have at least rudimentary color vision and appear deficient to anthropoids in other visual measures such as acuity. The most striking difference between prosimian and anthropoid auditory sensitivity is the increased sensitivity of the former group to high frequencies. No psychophysical data have been published on olfactory sensitivity of prosimians, but the relatively large olfactory areas in their brains and their propensity for scent marking strongly suggest that they have acute olfactory sensitivity. Most data on gustatory thresholds in prosimians does not permit sensitivity estimation since the data are joint functions of sensitivity as well as preferences.     

Prosimian learning capacities

A survey of the literature on learning by prosimian primates contradicts a traditional view that they are untrainable. They learn simple operants such as bar pressing readily, work well for the usual rewards, and respond in predictable fashion on schedules of partial reinforcement. Two-dimensional visual discriminations involving pattern and brightness also are learned, as are three-dimensional object discriminations. In the area of complex learning, they not only acquire a variety of difficult tasks, but they also reach a final level of performance that is at or near the level of anthropoids. In each of the following areas, at least one experiment is described in which a prosimian species did as well as one or more anthropoid species: object discrimination learning set, discrimination reversal, delayed response, instrumentation, oddity, and relational problems. The anthropoids to which they are most apt to compare favorably are New World monkeys, a group which they resemble physically, especially with respect to degree of manipulativeness, cortical development, and visual acuity.     

Digestive capacities,inbreeding and growth capacities in juvenile Arctic charr Salvelinus alpinus

Genetic variation in growth performance was estimated in 26 families from two commercial strains of Arctic charr Salvelinus alpinus. Physiological determinants of growth and metabolic capacities were also assessed through enzymatic assays. A relatedness coefficient was attributed to each family using parental genotypes at seven microsatellite loci. After 15 months of growth, faster growing families had significantly lower relatedness coefficients than slower growing families, suggesting their value as indicators of growth potential. Individual fish that exhibited higher trypsin activity also displayed higher growth rate, suggesting that superior protein digestion capacities can be highly advantageous at early stages. Capacities to use amino acids as expressed by glutamate dehydrogenase (GDH) activities were lower in the liver of fast‐growing fish (13–20%), whereas white muscle of fast‐growing fish showed higher activities than that of slow‐growing fish for amino acid metabolism and aerobic capacity [22–32% increase for citrate synthase (CS), aspartate aminotransferase (AAT) and GDH]. The generally higher glycolytic capacities (PK and LDH) in white muscle of fast‐growing fish indicated higher burst swimming capacities and hence better access to food.     

Increased vital and total lung capacities in Tibetan compared to Han residents of Lhasa (3,658 m).

Larger chest dimensions and lung volumes have been reported for Andean high-altitude natives compared with sea-level residents and implicated in raising lung diffusing capacity. Studies conducted in Nepal suggested that lifelong Himalayan residents did not have enlarged chest dimensions. To determine if high-altitude Himalayans (Tibetans) had larger lung volumes than acclimatized newcomers (Han "Chinese"), we studied 38 Tibetan and 43 Han residents of Lhasa, Tibet Autonomous Region, China (elevation 3,658 m) matched for age, height, weight, and smoking history. The Tibetan compared with the Han subjects had a larger total lung capacity [6.80 +/- 0.19 (mean +/- SEM) vs 6.24 +/- 0.18 l BTPS, P less than 0.05], vital capacity (5.00 +/- 0.08 vs 4.51 +/- 0.10 1 BTPS, P less than 0.05), and tended to have a greater residual volume (1.86 +/- 0.12 vs 1.56 +/- 0.09 1 BTPS, P less than 0.06). Chest circumference was greater in the Tibetan than the Han subjects (85 +/- 1 vs 82 +/- 1 cm, P less than 0.05) and correlated with vital capacity in each group as well as in the two groups combined (r = 0.69, P less than 0.05). Han who had migrated to high altitude as children (less than or equal to 5 years old, n = 6) compared to Han adult migrants (greater than or equal to 18 years old, n = 26) were shorter but had similar lung volumes and capacities when normalized for body size. The Tibetans' vital capacity and total lung capacity in relation to body size were similar to values reported previously for lifelong residents of high altitude in South and North America. Thus, Tibetans, like North and South American high-altitude residents, have larger lung volumes. This may be important for raising lung diffusing capacity and preserving arterial oxygen saturation during exercise.     

Heterotrophic capacities of Plectonema boryanum

Acquisition of the dark heterotrophic growth capacity on glucose in Plectonema boryanum involves both adaptation and enrichment of a fast-growing genotype. The adaptation includes induction of functions involved in glucose incorporation and increase in glucose-6-phosphate dehydrogenase activity. Photosynthetic products are implicated in the control of both systems. Efficient energy conversion in the dark, as measured by cyanophage multiplication, correlates in time with the increase in potential for glucose incorporation while heterotrophic growth capacity correlates with the increase in glucose-6-phosphate dehydrogenase activity. The lower efficiency of heterotrophic growth compared to photoautotrophic growth is discussed in light of the conservation of the photosynthetic potency in the heterotrophic cells.Abbreviations DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea - DTT dithiothreitol - G6P glucose-6-phosphate - NADP nicotinamide adenine dinucleotide phosphate - NTG N-methyl-N-nitro-N-nitrosoguanidine - RUDP ribulose-1,5-diphosphate - TCA trichloroacetic acid Dedicated to Prof. R. Y. Stanier on the occasion of his 60th birthday     

Cognitive capacities for cooking in chimpanzees

The transition to a cooked diet represents an important shift in human ecology and evolution. Cooking requires a set of sophisticated cognitive abilities, including causal reasoning, self-control and anticipatory planning. Do humans uniquely possess the cognitive capacities needed to cook food? We address whether one of humans'' closest relatives, chimpanzees (Pan troglodytes), possess the domain-general cognitive skills needed to cook. Across nine studies, we show that chimpanzees: (i) prefer cooked foods; (ii) comprehend the transformation of raw food that occurs when cooking, and generalize this causal understanding to new contexts; (iii) will pay temporal costs to acquire cooked foods; (iv) are willing to actively give up possession of raw foods in order to transform them; and (v) can transport raw food as well as save their raw food in anticipation of future opportunities to cook. Together, our results indicate that several of the fundamental psychological abilities necessary to engage in cooking may have been shared with the last common ancestor of apes and humans, predating the control of fire.     

Heat capacities of protein functional groups

Using a precise technique of scanning calorimetry the heat capacities of a series of carboxylic acids and their sodium salts, alcohols, and N-substituted amides have been measured from 5 to 100 degrees C. From these data, the partial molar heat capacities of CH2, CONH, COOH, and COONa groups have been determined. It is shown that the heat capacity of the CH(2) group in aqueous solution is independent of the type of compound used for its determination, is positive at low temperature, and is linearly decreasing in magnitude with an increase in temperature. In contrast, the heat capacities of COOH and COONa groups in aqueous solution are negative at room temperature and their magnitude non-linearly decreases with an increase in temperature. It appears that the partial heat capacity of CONH group in aqueous solution depends on the type of model compound used for its determination. These differences correlate with the difference in the water accessible surface area of atoms in the CONH group in different model compounds.     

Catalatic capacities in heat-shocked Euglena cells

1. Various heat treatments were applied to the wild strain Z. Klebs. of Euglena gracilis. 2. Samples of cells were taken at day 1 of the culture at 26 degrees C in a 33 mM lactate medium, when the catalatic capacities of the catalase were highest. 3. They were either submitted to heat treatments (36 and 38 degrees C), or heat-shocks (40, 42 degrees C) or non-permissive heat stress (45 degrees C) for 15 min, 1 and 2 hr. 4. After a 2-hr 45 degrees C treatment the cells were unable to recover normal physiological functions. 5. Heat treatments between 36 and 38 degrees C decreased the catalatic capacities of cells, while heat-shocks at 40 and 42 degrees C strongly reinforced these capacities of hydrogen peroxide dismutation. 6. Having been heat-shocked at 42 degrees C for 2 hr, the cells became different from control cells: (a) after several months of culture, they displayed catalatic capacities increased by 65%; (b) they were able from now on to survive a 2 hr heat shock at 45 degrees C.     

Evolutionary changes in Primate sensory capacities

This paper is a review of laboratory research on sensory capacities in Primates with emphasis on evolutionary changes in the capacities. Man, great apes and Old World monkeys have virtually identical color vision, a result consistent with the generalization that these relatively diverse species have reached a plateau in the evolution of color vision, Capuchin and squirrel monkeys are protonomalous trichromats thus suggesting a widespread relative insensitivity to red among New World monkeys. Of the prosimians, only tree shrews have been extensively tested for color vision capability and they are deuteranopic dichromats.There is clear evidence of a decline in the upper audible frequencies and the most audible frequencies during Primate evolution. Although the olfactory portion of the brain has declined markedly in relative size during Primate evolution, there is no corresponding research showing difference in olfactory sensitivity across the living Primate genera. Existing research on gustatory sensitivity in Primates is too limited to permit any evolutionary conclusions.     

Magnetophoretic mobilities correlate to antibody binding capacities

METHODS: A methodology and a mathematical theory have been developed, which allow quantitation of the expression levels of cellular surface antigens using immunomagnetic labels and cell tracking velocimetry (CTV) technology. RESULTS: Quantum Simply Cellular (QSC) microbeads were immunomagnetically labeled with anti-CD2 fluorescein isothiocyanate (FITC) antibodies and anti-FITC MACS paramagnetic nanoparticles. Magnetophoretic mobility has been defined as the magnetically induced velocity of the labeled cell or microbead divided by the magnetophoretic driving force, proportional to the magnetic energy density gradient. DISCUSSION: Using computer imaging and processing technology, the mobility measurements were accomplished by microscopically recording and calculating the velocity of immunomagnetically labeled QSC microbeads in a nearly constant magnetic energy gradient. A calibration curve correlating the measured magnetophoretic mobility of the immunomagnetically labeled microbeads to their antibody binding capacities (ABC) has been obtained. CONCLUSION: The results, in agreement with theory, indicate a linear relationship between magnetophoretic mobility and ABC for microbeads with less than 30,000 ABC. The mathematical relationships and QSC standardization curve obtained allow determination of the number of surface antigens on similarly immunomagnetically labeled cells.     

Leptin regulates functional capacities of polymorphonuclear neutrophils

Recent studies report that leptin may be able to modulate some functions of cells involved in non-specific immune response. We recently found that a functional leptin receptor is present on polymorphonuclear neutrophils (PMNs) and may be able to influence their oxidative capacities. We demonstrate here for the first time that leptin is also able to stimulate chemotaxis of PMNs and exerts by itself a chemoattractive effect comparable to that of well-known formyl-methionyl-leucyl-phenylalanine, and a stimulating effect on intracellular hydrogen peroxide production, without modification of phagocytosis     

Evolution of learning capacities and learning levels

Humans strongly depend on individual and social learning, both of which are highly effective and accurate. I study the effects of environmental change on the evolution of the effectiveness and accuracy of individual and social learning (individual and social learning levels) and the number of pieces of information learned individually and socially (individual and social learning capacities) by analyzing a mathematical model. I show that individual learning capacity decreases and social learning capacity increases when the environment becomes more stable; both decrease when the environment becomes milder. I also show that individual learning capacity increases when individual learning level increases or social learning level decreases, while social learning capacity increases when individual or social learning level increases. The evolution of high learning levels can be triggered when the environment becomes severe, but a high social learning level can evolve only when a high individual learning level can simultaneously evolve with it.     

Evaluation of antioxidant capacities of green microalgae

Three strains of green microalgae, Chlorococcum sp.C53, Chlorella sp. E53, and Chlorella sp.ED53 were studied for their antioxidant activities. Crude extracts of these microalgae in hot water and in ethanol were examined for their total phenolic contents and for their antioxidant capacities. In order to determine their phenolic contents, the Folin–Ciocalteu method was used. As for the determination of their antioxidant capacities, four different assays were used: (1) total antioxidant capacity determination; (2) DPPH radical scavenging assay; (3) ferrous ion chelating ability assay; and (4) inhibition of lipid peroxidation (using thiobarbituric acid reactive substance). For all the strains we have studied, their ethanolic extract showed more antioxidant activities than their hot water extract. Categorically, the ethanolic extract of Chlorella sp.E53 exhibited both the highest total phenolic content of 35.5?±?0.14 mg gallic acid equivalent (GAE) g^?1 dry weight and the highest DPPH radical scavenging of 68.18?±?0.38 % at 1.4 mg mL^?1 (IC₅₀ 0.81 mg mL^?1), whereas Chlorella sp.ED53 showed both the highest ferrous ion chelation activity of 42.78?±?1.48 % at 1 mg mL^?1 (IC₅₀ 1.23 mg mL^?1) and the highest inhibition of lipid peroxidation of 87.96?±?0.59 % at 4 mg mL^?1. This high level of inhibition is comparable to 94.42?±?1.39 % of butylated hydroxytoluene, a commercial synthetic antioxidant, at the same concentration.