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Biomedical subjects

S Madison

Publications and source records attributed to S Madison.

5 recordsLinked to original sources
PubMed1992

Multiphasic effect of morphine on the release of substance P from rat trigeminal nucleus slices.

It is generally accepted that morphine acts presynaptically to inhibit substance P (SP) release from afferent terminals in the trigeminal nucleus. Recent studies, however, provide evidence that opioids produce both inhibitory and excitatory effects on SP release which are concentration- and receptor subtype-dependent. In the present study, we have examined a wide range of morphine concentrations on K(+)-evoked SP release from rat trigeminal nucleus caudalis slices. Immunoreactive SP was measured in perfusates. Morphine produced multiphasic effects on K(+)-evoked SP release without affecting basal release. A very low nanomolar concentration (1 nM) suppressed release, higher nanomolar concentrations (100-300 nM) facilitated release, a low micromolar concentration (3 microM) suppressed release, and a higher micromolar concentration (30 microM) facilitated release. These effects were abolished by opioid receptor blockade with naloxone (30 nM). Thus, morphine produces a complex bi-directional modulation of SP release from TNC which is concentration- and possibly receptor subtype-dependent.

Animals↗
PubMed1992

Intracanal placement of Ca(OH)2: a comparison of techniques.

Ten extracted human maxillary first molars were selected with a variety of root curvatures. The distofacial roots were resected and the mesiofacial canals were instrumented to a size #25 K file. Three techniques were used to introduce Ca(OH)2 paste into the instrumented canals. These techniques were evaluated for their ability to carry the Ca(OH)2 to working length and also to produce a dense fill. The Lentulo spiral was most effective in carrying the paste to working length. The Lentulo spiral also produced the highest quality fill. The Calasept injection system followed by a #25 finger plugger was the second most effective technique. Counterclockwise rotation of a #25 K file was the least effective of the techniques tested.

Calcium Hydroxide↗
PubMed1992

Medications and temporaries in endodontic treatment.

We have attempted to present in this article an overview of the medications used as intracanal dressings during root canal treatment and the materials used to seal endodontic access preparations. Because all the medications reviewed have an antimicrobial effect (with the exception of steroids), they seemingly would be useful in root canal treatment. However, the potentially harmful side effects of the chemical agents, which include cytotoxicity and antigenicity, may make the treatment worse than the cure. With an improved understanding of the principles of root canal cleaning, strong medications placed into canals may be unnecessary. At best, intracanal dressings should be used only in situations that might benefit from such therapy. Temporary restoration of endodontically treated teeth is an essential part of root canal therapy. Commonly used materials and techniques for their uses have been presented. With proper temporization and timely final restoration, the potential for coronal microleakage will be minimized.

Dental Cements↗
PubMed1991

Management of endodontic emergencies.

Endodontic emergencies include situations of pain or swelling that require the immediate attention of a dentist. These emergencies interrupt the schedule of the patient and the dental team. This article reviews the clinical conditions that might require emergency therapy, etiologies of these conditions, and the minimal treatment needed to alleviate the signs and symptoms. Current opinions on these issues are presented.

Acute Disease↗