Osage orange, a tree native to Texas, Oklahoma, and Arkansas, was planted widely in the United States as a living fence from 1850-1875. It has naturalized over much of its planted range and is an ...early successional species. Economically the tree has had a wide number of uses including for bows, yellow dye, and building materials. It is used for fence posts and is a potential source for a proteolytic enzyme. Its taxonomy, anatomy, morphology, chemical constitutents, medicinal uses, and toxicity are discussed in this paper and related to its economic importance.
Albolabrin is a snake toxin that contains a RGD-(Arg-Gly-Asp) sequence motif and competes with fibrinogen to bind to the integrin alpha IIb beta 3 (GpIIb-IIIa) on platelets. It thus inhibits platelet ...aggregation and cell-cell adhesion. It shows a high sequence similarity to other disintegrins, yet the reported disulfide bonding pattern for this peptide differs from that of others in this family. Recently we reported the assignment of the 1H-NMR spectrum of albolabrin and a preliminary description of its secondary structure Jaseja, M., Smith, K.J., Lu, X. Williams, J.A., Trayer, H., Trayer, I.P. & Hyde, E.I. (1993) Eur. J. Biochem. 218, 853-860. Here we present a more detailed description of the secondary and the tertiary structure, based on the 1H NMR results and simulated annealing methods. The structure of albolabrin in solution was calculated using 318 distance and 18 dihedral angle restraints. The average atomic RMS deviation between 12 refined structures and the mean structure was 3.1 A for the backbone. The protein appears to be highly mobile. Its structure is dominated by a series of turns and by three hairpins, each with a short region of distorted antiparallel beta-pleated sheet, held together by six disulfide bridges. The most well defined area is the hydrophobic core, residues 21-47 and 57-67, which is clustered around F40 and has a backbone atomic RMS deviation of only 1.3 A from the mean structure. The RGD adhesion sequence is found at the highly mobile tip of one of the beta-hairpins, protruding from the body of the protein. Many of these structural features are similar to those of other disintegrins, and differences in the disulfide bonding pattern of the disintegrins can be accomodated without significant energy penalty. Comparison of this structure with other proteins of similar function suggests that it is the RGD-loop, rather than the precise technology of the proteins, that is important to antagonist activity.
Albolabrin is a naturally occurring peptide from snake venom containing the sequence Arg‐Gly‐Asp (RGD). It inhibits platelet aggregation by blocking the binding of fibrinogen to the glycoprotein Gp ...IIb‐IIIa, on the surface of activated platelets. Albolabrin consists of 73 residues with six intramolecular disulphide bonds. The
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H‐NMR spectrum of albolabrin has been assigned using homonuclear two‐dimensional techniques and its secondary structure determined. Like kistrin and echistatin, two related peptides from snake venom, albolabrin appears to have little regular secondary structure in solution. Several bends and two short distorted β sheets are observed. The RGD sequence, important for binding to the receptor, lies in a mobile loop joining two strands of one of these β sheets. This loop undergoes a pH‐dependent conformational change.
Albolabrin is a naturally occurring peptide from snake venom containing the sequence Arg‐Gly‐Asp (RGD). It inhibits platelet aggregation by blocking the binding of fibrinogen to the glycoprotein Gp ...IIb‐IIIa, on the surface of activated platelets. Albolabrin consists of 73 residues with six intramolecular disulphide bonds. The 1H‐NMR spectrum of albolabrin has been assigned using homonuclear two‐dimensional techniques and its secondary structure determined. Like kistrin and echistatin, two related peptides from snake venom, albolabrin appears to have little regular secondary structure in solution. Several bends and two short distorted β sheets are observed. The RGD sequence, important for binding to the receptor, lies in a mobile loop joining two strands of one of these β sheets. This loop undergoes a pH‐dependent conformational change.
We evaluated the time course of carotid baroreflex adaptation to arterial pressure elevations induced by phenylephrine infusion (1 microgram/kg per min) in 13 normotensive volunteers. ...Vagally-mediated carotid baroreceptor-cardiac reflex responses were assessed serially with a staircase pressure/suction sequence delivered to a neck chamber. Carotid baroreflex stimulus-response relations shifted up the response (R-R interval) axis and to the right on the stimulus (pressure) axis (determined as the carotid distending pressure at saturation) within 90-120 s (time between measurements) during the first 10 min. The shifts in position of the reflex relation were sustained throughout the infusion. The position of operational point pressure, relative to carotid distending pressure at saturation, was unchanged throughout the infusion period. These data suggest that human carotid baroreceptor reflex relations change within minutes to retain beat-to-beat pressure regulation as the prevailing pressure increases.
Using the new capabilities of the Spitzer Space Telescope and extensive multiwavelength data from the Spitzer Infrared Nearby Galaxies Survey (SINGS), it is now possible to study the infrared ...properties of star formation in nearby galaxies down to scales equivalent to large HII regions. We are therefore able to determine what fraction of large, infrared-selected star-forming regions in normal galaxies are highly obscured and address how much of the star formation we miss by relying solely on the optical portion of the spectrum. Employing a new empirical method for deriving attenuations of infrared-selected star-forming regions we investigate the statistics of obscured star formation on 500pc scales in a sample of 38 nearby galaxies. We find that the median attenuation is 1.4 magnitudes in H-alpha and that there is no evidence for a substantial sub-population of uniformly highly-obscured star-forming regions. The regions in the highly-obscured tail of the attenuation distribution (A_H-alpha > 3) make up only ~4% of the sample of nearly 1800 regions, though very embedded infrared sources on the much smaller scales and lower luminosities of compact and ultracompact HII regions are almost certainly present in greater numbers. The highly-obscured cases in our sample are generally the bright, central regions of galaxies with high overall attenuation but are not otherwise remarkable. We also find that a majority of the galaxies show decreasing radial trends in H-alpha attenuation. The small fraction of highly-obscured regions seen in this sample of normal, star-forming galaxies suggests that on 500pc scales the timescale for significant dispersal or break up of nearby, optically-thick dust clouds is short relative to the lifetime of a typical star-forming region.
Portrait Painter to the Elite Jones, Harvey L; Driesbach, Janice T; Holland, Katherine Church
Art of the Gold Rush,
03/1998
Book Chapter
Late in 1849 San Francisco gained its first resident professional painter when William Smith Jewett arrived on 17 December. Like many Argonauts, Jewett had traveled with a mining company, which broke ...up shortly after their ship reached port. The adventurers’ arrival amidst heavy rains, which soaked the city to the extent that “everything... here looks as though it had been shaken into a complete jelly,” delayed their progress to the goldfields.¹
Jewett had met with mixed success in his practice in the East,² but within six weeks of his arrival in California he reported securing a number of commissions. Although
Mitoquidone (MTQ) is the first member of a new group of pentacyclic pyrroloquinones developed for clinical evaluation as a potential anticancer agent. MTQ demonstrated good activity in a range of ...experimental solid tumour models, but was weakly active against standard prescreens such as the P388 murine leukaemia. Bone marrow suppression or other significant toxicity was not observed in preclinical studies. Twenty-seven patients were treated with MTQ given as a 4-h infusion either once every 21 days (150-600 mg/m2), once a week (200 mg/m2 per week), or as 5 daily doses repeated every 28 days (60-180 mg/m2 per day). The major adverse events encountered included nausea and vomiting (in virtually all patients), dyspnoea, tumour-related pain, and thrombocytopenia in several patients with pretreatment bone-marrow impairment. Phase I studies were suspended without a maximum tolerated dose being reached because of formulation difficulties. There were no major responses, although stable disease was observed in a number of patients with gastrointestinal malignancies. Temporary remission of B-symptoms occurred in two patients with lymphoma. The plasma pharmacokinetics of MTQ were investigated using an HPLC assay with fluorescence detection. Linear pharmacokinetics were observed with a terminal plasma half-life of 2.9 +/- 2.1 h (n = 18 doses). The volume of distribution was 3.4 +/- 2.6 l/kg and plasma clearance was 629 +/- 469 ml/min per m2. Several soluble analogues with similar antitumour activity are currently under investigation.
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