Phytochemicals: the good, the bad and the ugly?

Phytochemicals are constitutive metabolites that enable plants to overcome temporary or continuous threats integral to their environment, while also controlling essential functions of growth and reproduction. All of these roles are generally advantageous to the producing organisms but the inherent biological activity of such constituents often causes dramatic adverse consequences in other organisms that may be exposed to them. Nevertheless, such effects may be the essential indicator of desirable properties, such as therapeutic potential, especially when the mechanism of bioactivity can be delineated. Careful observation of cause and effect, followed by a coordinated approach to identify the responsible entities, has proved extremely fruitful in discovering roles for phytochemical constituents. The process is illustrated by selected examples of plants poisonous to animals and include the steroidal alkaloid toxin of Veratrum californicum (Western false hellebore), piperidine alkaloids of Lupinus species (lupines), and polyhydroxy indolizidine, pyrrolizidine and nortropane alkaloids of Astragalus and Oxytropis species (locoweeds), Castanospermum australe (Moreton Bay chestnut) and Ipomoea species (morning glories).     

Chemotaxis of the unicellular green algaDunaliella salina and the ciliatedTetrahymena pyriformis—effects of glycine,lysine, and alanine,and their oligopeptides

Chemotactic properties of amino acids (L-alanine, glycine and L-lysine) and their oligopeptides (10^–6M) and binding sites to these ligands were investigated in two unicellular models, the heterotrophicTetrahymena pyriformis and the auxotrophicDunaliella salina. Chemotaxis ofDunaliella induced by simple amino acids and their derivatives demonstrated that binding sites (receptors) for food molecules are not only present in the membrane but are also able to induce their basic physiological response. InTetrahymena, substances with special molecular structure and properties (polar, hydrophilic character of the signal peptide chain)-5-L-Lys, 5-Glywere required for chemoattraction, other peptides tested, lacking the required structure, were repellent. Divergences in chemotaxis and binding assays of both species suggest that trends of functional and binding parameters do not run parallel at this level of evolution.     

Flexibility in the order of action and in the enzymology of the nuclease, polymerases, and ligase of vertebrate non-homologous DNA end joining： relevance to cancer, aging, and the immune system

Nonhomologous DNA end joining （NHEJ） is the primary pathway for repair of double-strand DNA breaks in human cells and in multicellular eukaryotes. The causes of double-strand breaks often fragment the DNA at the site of damage, resulting in the loss of information there. NHEJ does not restore the lost information and may resect additional nucleotides during the repair process. The ability to repair a wide range of overhang and damage configurations reflects the flexibility of the nuclease, polymerases, and ligase of NHEJ. The flexibility of the individual components also explains the large number of ways in which NHEJ can repair any given pair of DNA ends. The loss of information locally at sites of NHEJ repair may contribute to cancer and aging, but the action by NHEJ ensures that entire segments of chromosomes are not lost.     

Intersectionality,the household economy,and ethnic entrepreneurship†

ABSTRACT

The literature on ethnic entrepreneurship emphasizes the role of ethnicity in facilitating group differences in enterprise based on access to ethnic-based resources. This treatment tends to conflate family-based resources with those of ethnicity. Using a framework derived from intersectionality theory, this qualitative study investigates how two aspects of the household economy, namely household composition and family ideology, shape intra-group differences among fifty middle-class Mexican-origin entrepreneurs. Findings reveal that household class and gender dynamics shape access to three family-based resources that facilitate enterprise: family labour, entrepreneurial capital, and inheritance; differences in entrepreneurial activity between family members exceed in some cases those observed between ethnic groups. This study reveals that intersectional dimensions of identity and collectivity influence entrepreneurial outcomes within ethnic households. This study encourages researchers to consider how multiple and intersecting dimensions of identity combine for a more complete understanding of American enterprise.     

Tau phosphorylation, tangles, and neurodegeneration: the chicken or the egg?

Pathological aggregation of the microtubule-associated protein tau is a common feature of many neurodegenerative diseases. Although tau aggregation is associated with abnormal tau phosphorylation, the role of phosphorylation in the initiation of neurodegeneration has been unclear. Now, several animal models and data from human patients provide converging evidence that aberrant tau phosphorylation can cause a neurodegenerative phenotype similar to that seen in human neurodegenerative diseases.     

Comparative Study of the Absorption,Plasma Levels,and Urinary Excretion of the “New” and the “Old” Lanoxin

A comparative study was performed of the absorption, the plasma level at equilibrium, and the urinary excretion of digoxin using two types of Lanoxin tablets, those produced before and after the 1972 alteration of the tablet manufacture.After a single dose the absorption rate of the new tablets was about twice as great as the old, both in young subjects and in the elderly patients. There were no significant differences in the plasma levels of digoxin for the two tablets 15 hours after the last administration in patients on an equal maintenance dose. The urinary excretion of digoxin increased about 40% when the “old” Lanoxin was replaced by the “new.” In elderly patients a daily dose of 0·125 mg twice daily of the new tablets should be sufficient to reach the therapeutic range. Young people need a higher dosage. If the kidney function is reduced by as much as 50% the dose should be reduced.     

Did the lumbriculids provide the ancestors of the branchiobdellidans,acanthobdellidans and leeches?

Revision of the literature concerning Agriodrilus (Oligochaeta, Lumbriculidae) and Acanthobdella (Acanthobdellida), both supposedly intermediate links in the traditional single line of evolution between lumbriculids, branchiobdellidans, and leeches, supports the alternative hypothesis of an independent origin of most if not all of these groups. Discovery of Phagodrilus, a lumbriculid that is clearly convergent with Agriodrilus in terms of the pharynx, lends further support to this concept. No decision as to the rankings of the various taxa can be made until new material of Acanthobdella is examined and all variable characters are used to determine synapomorphic character states and monophyletic groupings within this complex.     

Gifted and non-gifted students’ diurnal preference and the relationship between personality,sleep, and sleep quality

The current study had two main objectives. First, we examined gifted and non-gifted students’ diurnal preferences. Secondly, we examined the relationships among age, gender, personality, sleep quality, and chronotype of gifted students. Data were gathered from 276 gifted students and 1921 non-gifted students whose ages range between 7 and 17 years old, in same three cities in Turkey using the Composite Scale of Morningness (CSM) to assess diurnal preference, the Big Five Inventory (BIG-5) to assess personality and the Pittsburgh Sleep Quality Index (PSQI) to measure sleep quality. The first result indicated that gifted students were more morning-oriented compared to non-gifted students. The other main result was that the conscientiousness was the best predictor of CSM scores in gifted students. Additionally, conscientiousness, age, and global PSQI predicted CSM scores, respectively. Moreover agreeableness, conscientiousness, and emotional stability were positively related to morning orientation, while age, sleep quality, sleep latency, daytime dysfunction, and global PSQI were negatively related with chronotype in gifted students.     

The Fly Agaric,Soma,Father Christmas and the Vikings

1　ThemushroomTheFlyAgaric (Amanitamuscaria (L :Fr.)Hooker)belongstothegenusAmanitaPers .,agroupwhichhasplayedmajorrolesinhumanaffairsthrough outhistory .Itincludesboththemostlydeadlypoi sonousspeciesandpossiblythemostdeliciousspeciesofalloftheediblewildmushrooms.TheFlyAgaricrepresentsthebestknownofallthewildmushroomsandhadthegreatesteffectuponmankindandworldhistory .Itistobeseeninmanychildren′sbooksasthelarge ,brightredmushroomwiththewhitespots,invariablyassociatedwithfairiesandelves.It…     

β-decay,Bremsstrahlen, and the origin of molecular chirality

Summary A brief review is presented of the Vester-Ulbricht -decay Bremsstrahlen hypothesis for the origin of optical activity, and of subsequent experiments designed to test it. Certain of our experiments along these lines, begun in 1974 and involving the irradiation of racemic and optically active amino acids in a 61.7 KCi⁹⁰Sr–⁹⁰Y Bremsstrahlen source, have now been completed and are described. After 10.89 years of irradiation with a total Bremsstrahlen dose of 2.5×10⁹ rads, crystallinedl-leucine, norleucine, and norvaline suffered 47.2, 33.6, and 27.4% radiolysis, respectively, but showed no evidence whatsoever of asymmetric degradation.d- andl-Leucine underwent about 48% radiolysis and showed 2.4–2.9% radioracemization. Other samples in solution were too severely degraded to analyze. Probable intrinsic reasons for the failure of the Vester-Ulbricht mechanism to afford asymmetric radiolysis in the present and related experiments involving -decay Bremsstrahlen are enumerated.A portion of this material was presented at the 7th International Conference on the Origins of Life, Mainz, FRG, July 10–15, 1983     

Neuronal cholecystokinin,gastrin-releasing peptide,neurotensin, and β-endorphin in the intestine of the guinea pig

Summary The guinea-pig intestine was found to harbor nerve fibers containing immunoreactive cholecystokinin (CCK), gastrin-releasing peptide (GRP), neurotensin or - endorphin. Such fibers occurred in the myenteric and submucous ganglia and in the smooth muscle. GRP- and CCK-fibers, in addition, were found in the mucosa. Following colchicine treatment, neuronal perikarya in the myenteric ganglia displayed CCK-, GRP-, or -endorphin immunoreactivity. CCK-immunoreactive perikarya were located also in the submucous ganglia. Neurotensin-immunoreactive cell bodies could not be detected. The presence of immunoreactive neuronal perikarya in intramural ganglia indicates that CCK-, GRP- and -endorphin-containing fibers are intrinsic to the gut wall. GRP, neurotensin, and -endorphin were identified in extracts of smooth muscle by immunochemical and Chromatographic analysis.CCK-8, GRP and neurotensin contracted the isolated taenia coli. Tetrodotoxin reduced the response to CCK-8 but not that to GRP and neurotensin, suggesting that the two latter peptides act directly on smooth muscle receptors. The effect of CCK-8 is partly mediated by cholinergic nerves, since not only tetrodotoxin but also atropine greatly reduced the CCK-8-induced contractile response. The substance P (SP) antagonist, (d-Pro², d-Trp^7,9)-SP_1–11 had no effect on the CCK-8-induced contraction of the taenia. CCK-8 enhanced the SP-mediated (atropine-resistant) contractile response to electrical stimulation but not that mediated by acetylcholine. -Endorphin had no effect on the tension of the muscle but reduced the response to electrical stimulation (cholinergic as well as SP-mediated) through a naloxone-sensitive mechanism.While CCK-8 and -endorphin seem to play neuromodulatory roles in the taenia coli, the significance of GRP and neurotensin remains enigmatic.     

The composition,structure, and dynamics of the nekton of the upper epipelagic layer in the Aleutian and Commander basins,western Bering Sea,in the fall seasons of 2002–2013

The data on the composition and abundance of nekton species and their interannual variations within the upper epipelagic layer (0–50 m) in the Aleutian and Commander basins in the western Bering Sea that are considered in the article were collected during complex surveys that were conducted by the Pacific Research Fisheries Center in September and October of 2002–2013. The core species structures of the nekton communities in these two areas were similar: the chum salmon Oncorhynchus keta and the boreopacific gonate squid Boreoteuthis borealis were the most abundant species. Simpson’s dominance index varied synchronously in both areas, with higher values in the Aleutian Basin, until 2009. In the subsequent years, the values of the index for the studied areas became equal and varied asynchronously. An analysis of abundance showed that two types of species structure most often prevailed (with the dominance of either chum salmon or squid); in some years the species structure differed from that in other years. Species of the low-boreal and low-boreal-subtropical complexes were more abundant in the Commander Basin, reaching particularly high proportions in 2006, 2008, and 2012. Certain species showed similarity in the year-to-year dynamics of their abundance; however, these coincidences were frequently accidental. After the climate regime shift in 2006–2007, the total biomass of nekton in the Aleutian Basin decreased from 3241 to 1736 kg/km² (46%); in the Komandorskiye Basin it decreased from 2459 to 1976 kg/km² (20%).