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Polyenyne macrocycles with π-extended [9]- and [12]radialene frameworks have been synthesized. These radialenes exhibit restricted rotation of the aromatic rings, and the D3- and D4-symmetric structures in solutions have been determined by dynamic NMR. The macrocyclic radialenes bear small to medium inner cavities, and the small cavity of the π-extended [9]radialene can incorporate a silver cation.

Introduction: Recombinant human bone morphogenetic protein-2 (rh-BMP2) has osteoinductive properties. The sequence of osteogenesis induced by rh-BMP2 in a rat calvarial bone defect model was evaluated histologically. Material and methods: Atelopeptide type I collagen was selected as the carrier matrix for rh-BMP2. This collagen was mixed with 50@mg of rh-BMP2 and treated by lyophilization to make a suitable form for filling bone defects. Thirty Wistar rats (male; 10 weeks old) underwent craniotomy resulting in a round bone defect with a diameter of 4mm. Three weeks after the operation, the defect site was exposed to implant collagen with rh-BMP2 in the experimental group and collagen only in the control group. Three, 6 and 9 weeks after implantation, calvarial specimens were harvested and stained with haematoxylin/eosin. In addition, bromodeoxyuridine (BrdU) immunohistochemical staining was performed. Results: In the experimental group, marked ossification was found. In contrast, there was no tendency towards osteogenesis in the control group, 9 weeks after collagen implantation. In BrdU immunohistochemical staining, the number of BrdU-positive cells was significantly higher in the experimental group than in the control group, and was significantly higher at the periosteal site than at other sites at 3 and 6 weeks after implantation. Conclusions: rh-BMP2 exhibited osteoinductive properties, and markedly stimulated proliferation of periosteal cells.

Three extended [4]radialenes with two tricyclic rings connected with exocyclic butatriene units have been synthesized. The compounds, possessing thioxanthene and dihydroanthracene moieties as the terminal substituents, show a fast rotation around the butatriene bonds at ambient temperatures (ΔG^&thermod; = 13.7 and 14.9 kcal/mol, respectively). In contrast, the fluorene-substituted analogue shows a much higher rotational barrier (ΔG^&thermod; = 17.8 kcal/mol) of the butatriene bonds due to the reduced steric repulsion between the two fluorene moieties at the ground state.

[(OEP)As(OH)2]ClO4 (4-ClO4) and [(OEP)As(Ph)(OH)]ClO4 (12-ClO4) are synthesized in good yields by oxidative conversion of (OEP)AsCl (2) and (OEP)AsPh (10), respectively, with pyridinium tribromide followed by hydrolysis and counteranion exchange. 4-Cl is converted to [(OEP)As(R)(OH)]ClO4 (6-ClO4, R = Me; 8-ClO4, R = Et) and [(OEP)As(R)2]X (7-ClO4, R = Me; 9-PF6, R = Et) by the reaction with (COBr)2 followed by treatment with trialkylaluminum (alkyl = Me, Et) and counteranion exchange. The reaction of 6-Cl with PCl3 gives the corresponding chloride [(OEP)As(Me)(Cl)]Cl (13-Cl), from which [(OEP)As(Me)(OR)]ClO4 (14-ClO4, R = Me; 15-ClO4, R = Et; 16-ClO4, R = i-Pr), [(OEP)As(Me)(NH-n-Bu)]ClO4 (17-ClO4), [(OEP)As(Me)(NH-p-CH3C6H4)]ClO4 (18-ClO4), and [(OEP)As(Me)(Et)]ClO4 (19-ClO4) are synthesized. These compounds are stable toward air and moisture. The OH protons of [(OEP)As(R)(OH)]Cl (6-Cl, R = Me; 8-Cl, R = Et, 12-Cl, R = Ph) are acidic enough to generate [(OEP)As(R)(&dbd;O)] (20, R = Me; 21, R = Et, 22, R = Ph) by treatment of a solution of 6-Cl, 8-Cl, and 12-Cl with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). 6-Cl, 8-Cl, and 12-Cl are regenerated by treating a solution of 20, 21, and 22 with dilute HCl. The first characterization of an arsenic porphyrin 6-ClO4, by X-ray crystallographic analysis is presented.

Corticotropin (ACTH) secretion by the anterior pituitary is stimulated by catecholamines in vivo and in vitro. The nature of the response in vivo is controversial but appears to be mediated by beta-adrenergic receptors, whereas the response is dependent on alpha-adrenergic receptors in cultured anterior pituitary cells. In the present studies, by using a superfusion technique, we demonstrate that catecholamine stimulation of ACTH release from rat anterior pituitaries changes with time from a predominantly beta-adrenergic-mediated event to a predominantly alpha-adrenergic-mediated event. From 0 to 2 hr after initiating the superfusion, release of ACTH from anterior pituitary glands is stimulated up to 2.4-fold by the beta-adrenergic agonist l-isoproterenol. However, the ACTH secretory response to the alpha-adrenergic agonist l-phenylephrine is less than or equal to 5% of that to l-isoproterenol during the same time period. Beginning 2 hr after the start of the superfusion, the responsiveness to the beta-adrenergic agonist declines, and the response to the alpha-adrenergic agonist increases until, 10 hr after removal, greater than 95% of the catecholamine-inducible ACTH release is mediated by an alpha-adrenergic pathway. The addition of interleukin 1 alone to the medium from the beginning of the superfusion does not modify basal ACTH secretion rates and does not affect the acquisition of the response to phenylephrine. However, the presence of interleukin 1 does allow the maintenance of the full ACTH secretory response to isoproterenol. This effect of interleukin 1 is reversed by an interleukin 1 antagonist. These observations suggest an additional way in which immune regulators might interact with the hypothalamic-pituitary-adrenal axis.

In an isothermal atmosphere with an absorbing gas having a constant mixing ratio, the exact solution for the transmission for Lorentz lines is derived for any straight-line path between different pressure levels. A method to evaluate the transmission along a non-isothermal path is also developed under the same restriction for the absorbing gas. The method consists of reducing the actual path to an equivalent isothermal path. Comparison of the Curtis-Godson, Goody and the present approximations is made in evaluating the transmission due to several lines in the 15 micron CO2band in a non-isothermal atmosphere.

The infrared spectral radiance has been calculated near the limb of the earth, using a curved refracting atmosphere. Radiance was calculated in narrow spectral intervals for four atmospheric models representing a wide range of meteorological conditions. Comparison is made of the radiance across the limb for each model atmosphere in several narrow spectral intervals; two hypothetical filters are then convoluted with spectral radiance to show the effective radiance across the limb, as it might be viewed by a horizon sensor. The results indicate that the 15-μ carbon dioxide band and the rotational vapor band are best suited for horizon sensing and that neither is decisively superior on the basis of radiance. It is also shown that radiative flux calculated using the exact radiance values near the limb is only about 1% more precise than that calculated from an extrapolation to the limb of radiance values determined at zenith angles where the plane parallel approximation is valid.