The synthesis and purification of short model messenger RNAs modified with undecagold cluster are described. A monoamino undecagold cluster was introduced on the oxidized 3' cis-glycol group of the mRNA followed by reduction of the formed Schiff's base. The stability of the modified mRNA under the conditions used for in vitro messenger RNA translation is studied. The possibility of the formation of a specific translational initiation complex with bacterial ribosomes and modified mRNAs is shown. The results of these experiments indicate that the attachment of an undecagold cluster to a mRNA is a useful tool for electron microscopic and crystallographic studies.

Base Sequence↗

PubMedDate not supplied

Synthesis of an acetylcholine receptor-specific toxin derivative regioselectively labeled with an undecagold cluster.

The regioselective modification of a snake curaremimetic toxin is described. Toxin-alpha from Naja nigricollis was derivatized with an electron-dense maleimido undecagold cluster 5. The cluster-bound obtained toxin 8 has a very high affinity for the cholinergic binding site (Ki = 70 pM) of Torpedo marmorata nicotinic receptor. It is harboring a compact heavy atom core of about 8 A which makes it very useful for electron microscopy experiments.

Animals↗

PubMedDate not supplied

Nicotinic acetylcholine receptor labeled with a tritiated, photoactivatable agonist: a new tool for investigating the functional, activated state.

Upon agonist activation, the nicotinic acetylcholine receptor undergoes allosteric transitions leading to channel opening and sodium ion influx. The molecular structure of the agonist binding site has been mapped previously by photoaffinity labeling, but most photosensitive probes used for this purpose interact only with closed receptor states (resting or desensitized). We have synthesized two novel photoactivatable 4-diazocyclohexa-2,5-dienone derivatives as cholinergic agonist candidates, with the objective of identifying structural changes at the acetylcholine binding site associated with receptor activation. One of these ligands, 9b, is a functional agonist at muscle acetylcholine receptors in human TE 671 cells. In photolabeling experiments with 9b, up to 35% inactivation of agonist binding sites was observed at Torpedo acetylcholine receptors. Tritiated 9b was synthesized, and photolabeling was found to occur mainly on the alpha-subunit in a partially protectable manner. This novel radiolabeled photoprobe appears to be suitable for future investigation of the molecular dynamics of allosteric transitions occurring at the active acetylcholine receptor binding site.

Animals↗

PubMedDate not supplied

Complications of port-access cardiac surgery.

Port-Access cardiac surgery is a recent technology that is undergoing rapid development. The learning curve associated with this technique is a challenge even for the skilled and experienced cardiac surgeon. Mainly because of femoral cannulation, the use of guidewires, and working through small incisions, Port-Access cardiac surgery contains certain pitfalls that are clearly associated with the technology involved. These pitfalls currently require troubleshooting, but as the technology progresses, this may become less of an issue. Communicating these pitfalls to others is important to help others to avoid or better manage complications and to contribute to improving the technology of Port-Access techniques.

Cardiac Surgical Procedures↗

PubMedDate not supplied

Mandatory continuing education for hospital managers.

Because hospital managers and supervisors are more aware of the necessity to regularly upgrade their knowledge and skills, a health care center has created a mandatory management development program that not only fills employee and hospital needs but also provides empirical data for merit reviews. How this highly structured program was developed and organized is presented in this article.

Administrative Personnel↗