The phase behaviour of dispersions of Bis-Azo PC: photoregulation of bilayer dynamics via lipid photochromism

A phospholipid, 1,2-bis(4-(n-butyl)phenylazo-4'-phenylbutyroyl)phosphatidylcholine (Bis-Azo PC), has been synthesised and shown to form stable bilayer vesicles. Light-scattering measurements and differential scanning calorimetry show that a dispersion of the lipid has a cooperative phase transition at a similar temperature to that of dipalmitoylphosphatidylcholine, which Bis-Azo PC resembles in overall size. The phase behaviour of Bis-Azo PC has been investigated by fluorescence spectroscopy and using a series of spin-labelled fatty acid probes. Fluorescence measurements using chlorophyll a as probe sense the onset of the cooperative phase transition, but this is not clearly revealed by any of the spin probes tested. Hysteresis in the phase transition is detected both by light scattering measurements and by fluorescence spectroscopy. No transition is observed for a lipid analogue having a palmitic acid chain and a single azo-containing substituent. Bis-Azo PC is reversibly photochromic, isomerising on exposure to ultraviolet light to a photostationary state mixture where cis isomer predominates. Electron microscopy shows that photoisomerisation decreases average vesicle size, and light scattering and calorimetry demonstrate that the cooperative phase transition is abolished. Illumination with visible light establishes a new photostationary state where trans isomer predominates, and the phase transition is restored. The ability to modulate bilayer phase behaviour reversibly has possible application to relaxation studies of bilayer membrane function, and to drug delivery research.     

The benzodiazepine receptor ligand, methyl beta-carboline-3-carboxylate, is both sedative and proconvulsant in chicks

Certain pharmacological properties of methyl beta-carboline-3-carboxylate (beta-CCM), a benzodiazepine receptor ligand, have been investigated in chicks. Although beta-CCM has been established previously as an "inverse agonist" of benzodiazepine receptors in rodents, having effects opposite to those of benzodiazepines in a variety of tests, in chicks this compound had a different pharmacological profile. Firstly, in contrast to the overt convulsant action of beta-CCM in other species, beta-CCM (0.05-40 mg/kg) did not produce convulsions by itself in chicks, but it was only proconvulsant. Secondly and most surprisingly, beta-CCM, like diazepam, produced in chicks a sedation which could be blocked by the benzodiazepine receptor antagonist Ro 15-1788. Thus it appears that beta-CCM can function both as an agonist and as an inverse agonist in this animal.     

Analysis of acute explosive training modalities to improve lower-body power in baseball players

Complex training is the simultaneous combination of heavy resistance training and plyometrics. The objective of this study was to test the effects of complex training vs. heavy resistance or plyometric interventions alone on various power-specific performance measures. Forty-five male division II junior college baseball players participated in 3 separate 4-week resistance training interventions. Subjects were randomly assigned to one of three groups. In a counterbalanced rotation design, each group participated in complex, heavy resistance, and plyometric training interventions. Each individual was tested in 20-yd (SP20), 40-yd (SP40), 60-yd (SP60), vertical jump, standing broad jump, and T-agility measures pre- and post-4-week training interventions. There was no statistical significant difference (p = 0.11) between groups across all performance measures. Review of each distinct training intervention revealed greater percent improvements in SP20 (0.55; -0.49; -0.12), SP40 (0.26; -0.72; -1.33), SP60 (0.27; 0.15; -0.27), standing broad jump (1.80; 0.67; 1.1), and T-agility (2.33; 1.23; -0.04) with complex training interventions than with the heavy resistance or plyometric training interventions, respectively. Plyometric-only training showed greater percent changes in vertical jump (1.90) than with complex (0.97) or heavy resistance training (0.36). The present results indicate that complex training can provide strength and conditioning professionals equal, if not slightly greater, improvements in muscular power than traditional heavy resistance- and plyometric-only interventions in moderately trained athletes. Complex training can be another valuable method for short-term power and speed improvements in athletes in isolation or in conjunction with other power development methods.     

Synthesis,initial SAR and biological evaluation of 1,6-dihydroimidazo[4,5-d]pyrrolo[2,3-b]pyridin-4-amine derived inhibitors of IκB kinase

A new series of tricyclic-based inhibitors of IKK have been derived from an earlier lead compound. The synthesis and structure–activity relationships (SAR) are described. Compound 4k inhibited TNF production in rats stimulated with LPS.     

Enhanced transpiration rate in the high pigment 1 tomato mutant and its physiological significance

Tomato high pigment (hp) mutants represent an interesting horticultural resource due to their enhanced accumulation of carotenoids, flavonoids and vitamin C. Since hp mutants are known for their exaggerated light responses, the molecules accumulated are likely to be antioxidants, recruited to deal with light and others stresses. Further phenotypes displayed by hp mutations are reduced growth and an apparent disturbance in water loss. Here, we examined the impact of the hp1 mutation and its near isogenic line cv Micro-Tom (MT) on stomatal conductance (gs), transpiration (E), CO(2) assimilation (A) and water use efficiency (WUE). Detached hp1 leaves lost water more rapidly than control leaves, but this behaviour was reversed by exogenous abscisic acid (ABA), indicating the ability of hp1 to respond to this hormone. Although attached hp1 leaves had enhanced gs, E and A compared to control leaves, genotypic differences were lost when water was withheld. Both instantaneous leaf-level WUE and long-term whole plant WUE did not differ between hp1 and MT. Our results indicate a link between exaggerated light response and water loss in hp1, which has important implications for the use of this mutant in both basic and horticultural research.     

Signet ring adenocarcinoma metastatic to the bronchus and mimicking goblet cell hyperplasia. A case report

BACKGROUND: Goblet cells in the lower respiratory tract are metaplastic bronchial epithelial cells usually associated with asthma or chronic bronchitis. Goblet cells acquire their name by a tendency to distend with mucus, with subsequent distortion in cell shape. Due to similarity of shape, metaplastic goblet cells and signet ring cells can be easily confused in cytologic samples. CASE: A 55-year-old male with a history of gastrointestinal adenocarcinoma underwent brushing, washing and biopsy of a bronchial lesion. The bronchial wash and brush samples showed a very cellular specimen, with large aggregates of distended columnar cells. These were arranged in long strips, thick bundles and occasional three-dimensional aggregates. Some aggregates contained numerous rounded cells with markedly distended cytoplasm. The rounded cells were slightly larger than the distended columnar cells. These cells had a relatively large but innocuous-appearing nucleus displaced to the periphery of the cell. The corresponding bronchial biopsy revealed signet ring adenocarcinoma, presumably metastatic from the gastrointestinal primary. CONCLUSION: Signet ring adenocarcinoma, either primary or metastatic, can be difficult to diagnose in cytologic and histologic specimens. There are numerous mimics of signet ring cells, both benign and neoplastic. In respiratory cytologic specimens, one of the benign imposters is goblet cell metaplasia.