Molecular gas clumps from the destruction of icy bodies in the ß Pictoris debris disk.

Many stars are surrounded by disks of dusty debris formed in the collisions of asteroids, comets, and dwarf planets, but is gas also released in such events? Observations at submillimeter wavelengths of the archetypal debris disk around ß Pictoris show that 0.3% of a Moon mass of carbon monoxide orbits in its debris belt. The gas distribution is highly asymmetric, with 30% found in a single clump 85 astronomical units from the star, in a plane closely aligned with the orbit of the inner planet, ß Pictoris b. This gas clump delineates a region of enhanced collisions, either from a mean motion resonance with an unseen giant planet or from the remnants of a collision of Mars-mass planets.

Long term storage of callus cultures at low temperatures or under mineral oil layer.

Plant tissue cultures from various species were stored at low temperatures or under mineral oil overlay for 4 to 6 months without subcultures. After transfer to normal culture conditions, it was checked, with 3 strains, that growth characteristics and secondary metabolite production were preserved. The storage with a mineral oil overlay (easy to run and economical method) could be a possible alternative to cryogenic or low temperature storage for a large number of strains.

Chelerythrine is a potent and specific inhibitor of protein kinase C.

The benzophenanthridine alkaloid chelerythrine is a potent, selective antagonist of the Ca++/phospholopid-dependent protein kinase (Protein kinase C: PKC) from the rat brain. Half-maximal inhibition of the kinase occurs at 0.66 microM. Chelerythrine interacted with the catalytic domain of PKC, was a competitive inhibitor with respect to the phosphate acceptor (histone IIIS) (Ki = 0.7 microM) and a non-competitive inhibitor with respect to ATP. This effect was further evidenced by the fact that chelerythrine inhibited native PKC and its catalytic fragment identically and did not affect [3H]- phorbol 12,13 dibutyrate binding to PKC. Chelerythrine selectively inhibited PKC compared to tyrosine protein kinase, cAMP-dependent protein kinase and calcium/calmodulin-dependent protein kinase. The potent antitumoral activity of celerythrine measured in vitro might be due at least in part to inhibition of PKC and thus suggests that PKC may be a model for rational design of antitumor drugs.

Benzophenanthridine alkaloids isolated from Eschscholtzia californica cell suspension cultures interact with vasopressin (V1) receptors.

Chelerythrine and sanguinarine, two benzophenanthridine alkaloids, have been isolated from a crude methanolic extract of Eschscholtzia californica cell suspension cultures by successive fractionations. These two molecules exhibited affinity for rat liver vasopressin V1 receptors and are competitive inhibitors of [3H]-vasopressin binding within the micromolar range (Ki). Chelerythrine and sanguinarine represent two of the first non-peptidic structures providing original chemical leads for the design of synthetic vasopressin compounds.

Ability of different flavonoids to inhibit the procoagulant activity of adherent human monocytes.

Sixty-five natural flavonoids of various chemical classes were screened for their ability to inhibit the procoagulant activity of adherent human monocytes stimulated by endotoxin and interleukin-1 beta in vitro. Eighteen of these compounds inhibited the interleukin-1 beta-induced expression of tissue factor on human monocytes, but the most active compound was a biflavonoid: hinokiflavone.

Verbascoside isolated from Lantana camara, an inhibitor of protein kinase C.

Verbascoside [1] isolated from Lantana camara is an inhibitor of protein kinase C (PKC) from the rat brain. Half-maximal inhibition of the kinase occurs at 25 microM. Verbascoside interacted with the catalytic domain of PKC and was a competitive inhibitor with respect to ATP (Ki = 22 microM) and a non-competitive inhibitor with respect to the phosphate acceptor (histone IIIS). This effect was further evidenced by the fact that verbascoside inhibited native PKC and its catalytic fragment identically and did not affect [3H]-phorbol-12,13-dibutyrate binding to PKC. The antitumor activity of verbascoside measured in vitro might be due at least in part to inhibition of PKC.

Khusimol, a non-peptide ligand for vasopressin V1a receptors.

In the course of a random screen of various plant extracts, khusimol [1], a non-peptide molecule isolated from the root of Vetiveria zizanioides, was found to competitively inhibit the binding of vasopressin to rat liver V1a receptors (Ki = 50 microM). The 1H- and 13C-nmr spectra of this sesquiterpene alcohol were assigned unambiguously.

[Postoperative pulmonary complications following surgery for carcinoma of the esophagus]. / Complications pulmonaires post-opératoires de la chirurgie carcinologique de l'oesophage.

Pulmonary complications frequently occur during the postoperative period following surgery for neoplasms of the oesophagus. The aetiology varies according to the time of their onset but the clinical signs and treatment are essentially the same. The problems encountered and related either to anaesthesia, to the surgical approach to the position of the patient. It is after the third day that complication develop related at one and the same to the past history, classical in such patients, (tobacco, chronic bronchitis, alcoholism) and the ectopic position of an abdominal viscus.