Formation of electrical connections between cultured identified neurons and muscle fibers of the snail Helisoma.

We studied the formation of connections between identified neurons removed from the buccal ganglion of the snail Helisoma and muscle fibers dissociated from the buccal mass. Three types of identified neurons--B19, B5, and B4--were placed into cell culture and muscle fibers from the supralateral tensor muscle (SLT), normally innervated by B19, were subsequently plated adjacent to the neuronal cell bodies. Growth cones from the neurons contacted the muscle fibers within 6-12 h after isolation.

Human thyroid cells transfected with SV40 DNA retain the TSH receptor.

Human thyroid cells were transfected with SV40 DNA using the calcium phosphate co-precipitation technique. The transfected cells grew rapidly and could be passaged readily. TSH and the immunoglobulin fraction from a patient with hyperthyroid Graves' disease stimulated adenylate cyclase activity in the transfected cells.

Pharmacokinetics of nalbuphine during parturition.

Nalbuphine hydrochloride (Nubain) is a relatively new agonist-antagonist analgesic, chemically related to both oxymorphone and naloxone, which can be used as a systemic obstetric analgesic. After intravenous administration to six patients in labor at term, serial maternal serum specimens were obtained and assayed for their nalbuphine concentration. The maternal disposition of nalbuphine followed a two-compartment pharmacokinetic model, with an initial distribution phase of 4 to 20 minutes and a terminal elimination half-life of 2.

Thyrotropin-induced formation of functional follicles in primary cultures of ovine thyroid cells.

In primary cultures of ovine thyroid cells, TSH induced the expression of several differentiated functions including the formation of follicles, and synthesis and storage of iodinated thyroglobulin in the follicular lumen. In the present report, these follicles were shown by transmission (TEM) and scanning electron microscopy (SEM) to be intact, comprised of two or more cells and to possess numerous microvilli on the inner cell membranes facing the follicular lumen. The TSH-induced formation of follicles was reversible and dynamic, with the kinetics of formation preceding that of iodination.

A dosing nomogram for continuous infusion intravenous naloxone.

Naloxone hydrochloride is extremely valuable for diagnosing and managing the opioid overdose. Due to naloxone's short half life and a long duration of action of most opioids, repeated naloxone dosing often is required to prevent the recurrence of respiratory depression. An alternative to repeated bolus administration is a continuous IV infusion.