Nasopharyngeal carcinoma: the role of the dentist in assessment, early diagnosis and care before and after cancer therapy.

Nasopharyngeal carcinoma (NPC) may present first to the dental profession as facial pain, neck masses, difficulty in speech and swallowing, ear, nose and throat symptoms, or as symptoms of temporomandibular disorders (TMD). Recognition of the signs and symptoms are essential in order to lead to the correct diagnosis, and to avoid inappropriate intervention that may further delay diagnosis and initiation of treatment of the cancer. Differentiation between NPC and TMD may be facilitated by specific questioning of other symptoms that are not frequently associated with TMD such as neck masses, nasal obstruction, recent unilateral hearing deficit and epistaxis. The general dentist can become involved at three stages of a patient's experience with NPC: Stage 1, recognition of signs and symptoms; Stage 2, pre-treatment dental assessment; and Stage 3, post-treatment support. This paper is intended to: (1) alert the general dentist of the signs and symptoms associated with NPC, such that timely and appropriate treatment may ensue; (2) provide a basic outline for assessment, preparation, palliation and continuing care of a patient diagnosed with NPC; and (3) underline the significant role of the general dentist in achieving an optimal quality of life for these patients

A computer-based system for controlling plasma opioid concentration according to patient need for analgesia.

Microprocessor-controlled infusion pumps, which allow a patient to self-administer bolus doses of an analgesic to relieve pain, are becoming commonplace. While these patient-controlled analgesia (PCA) systems overcome the large interpatient variations in pharmacokinetics, they do not provide steady relief from pain since they rely on delivering a drug in small, incremental doses. To overcome this problem, the authors developed an algorithm and computer-pump system that allows patients to control their own plasma concentration of analgesic. This approach uses individually predetermined pharmacokinetic parameters to provide steady plasma opioid concentrations that can be increased or decreased by the patient in line with the need for more pain relief or fewer side effects. The control software uses a novel, recursive algorithm to compute the pump rates necessary to maintain constant plasma drug (e.g. morphine) concentrations at desired values and to reach a new steady concentration in response to patient requests. This report describes the mathematical approach to the problem of control of plasma opioid concentration, the application of this new drug delivery system to management of persistent pain in cancer patients undergoing bone marrow transplantation, and the magnitude of pharmacokinetic variability with morphine in this patient population. Results are presented from individual patients using this adjustable drug delivery system continuously for up to 2 weeks to control pain from oral mucositis.

Patient-controlled analgesic administration. A comparison of steady-state morphine infusions with bolus doses.

The authors have shown previously that bone marrow transplant (BMT) patients who self-administered bolus doses of morphine gained equal oral mucositis pain relief while using less drug compared with similar patients receiving morphine by staff-controlled continuous infusion. In a follow-up study they compared the efficacy and side effects of morphine in two groups of marrow transplant patients who controlled their own analgesic administration either by conventional bolus-dose, patient-controlled analgesia (PCA) or by adjusting the rate of continuous morphine infusion to increase or decrease their plasma morphine concentration. Patients controlling their morphine infusion rates (pharmacokinetically based patient-controlled analgesia [PKPCA] group) obtained more relief from oral mucositis pain than did patients using conventional PCA. Patients in the PKPCA group used more morphine than PCA patients and achieved superior pain relief without significant increases in side effects (e.g., nausea, mood changes, sedation). The authors conclude that PKPCA improves the management of prolonged, severe pain in marrow transplant patients and that this approach to patient-controlled analgesia may be useful in other types of persistent pain.

Comparison of the effects of dopamine, dobutamine, and dopexamine upon renal blood flow: a study in normal healthy volunteers.

1. We compared the effects of dopexamine, dopamine and dobutamine on the heart rate, blood pressure and renal blood flow of six healthy volunteers in an open triple crossover trial. 2. The results suggest that at the dose ranges investigated dopamine was the most effective agent for increasing renal blood flow.

Anesthesia for tonsillectomy and adenoidectomy.

Despite advances in the anesthetic pharmacopeia and improved noninvasive monitoring techniques, subjective bias and individual clinical experience remain major determinants of individual practice. Medicolegal pressures have increased in recent years, as has the concept of shared responsibility for surgical and anesthetic complications. New standards of anesthesia monitoring and practice are evolving in response to the need for perioperative risk management and cost-effective surgical care. Continued vigilance and close communication between the otolaryngologist and anesthesiologist remain key elements for safe anesthetic practice.

Drawover anaesthetic systems. Factors determining the inspired oxygen concentration.

The factors that determine the inspired oxygen concentration delivered by drawover anaesthetic systems were studied in the laboratory and in anaesthetised patients. The inspired oxygen concentration is dependent upon oxygen flow, reservoir volume and total ventilation; respiratory rate and inspiration:expiration ratio have a small influence. A reservoir of at least of 1 m corrugated tube (internal volume 415 ml) makes optimal use of a 4 litres/minute oxygen flow. Delivery of a safe inspired oxygen concentration can be ensured with economical oxygen flows.

Pulse oximetry. An assessment in anaesthetised dental patients.

The applications of a pulse oximeter were studied in dental day case surgery using nasal mask anaesthesia. Changes in arterial oxygen saturation were sensitively and rapidly detected, in the absence of cyanosis. Impaired oxygenation can be detected before cyanosis develops.

Anaesthesia and mediastinal masses. A case report and review of the literature.

A case in which a mediastinal tumour caused complications including airway obstruction unrelieved by intubation during inhalational induction is described. Other case reports are reviewed and the anaesthetic management of patients with mediastinal tumours is discussed.

Binding of [14C]inosine to gustatory tissues of the turbot, Scophthalmus maximus.

Reversible specific binding of [14C]inosine has been demonstrated in turbot (Scophthalmus maximus) buccal tissues rich in taste buds. A highly significant correlation was found for a series of nucleosides and nucleotides between their feeding stimulant activity and their ability to displace bound [14C]inosine. It is concluded that the binding of inosine is the first step in the gustatory process.

Drugs from the sea--fact or fantasy?

Drugs from the sea are as much a potential marine resource as cultivated fish, and mineral deposits. The study of the chemical structure and properties of unusual metabolic products of marine life is a subject where marine ecology and the experimental sciences of chemistry, biochemistry, pharmacology and medicine share a common and complementary interest. The development of ad hoc collaboration between specialists has advanced basic knowledge and resulted in a significant feedback to marine biology and ecology as well as in the development of some useful drugs.

Partial characterization of a biologically active steroid glycosideisolated from the starfish Marthasterias glacialis.

1. A steroid glycoside (M(2)), which induces avoidance and other reactions in the mollusc Buccinum undatum, has been isolated from extracts of the starfish Marthasterias glacialis by ion-exchange chromatography. 2. The steroid glycoside was homogeneous by t.l.c. and contained glucose, quinovose, fucose and sulphate in the molar proportions 1:2:1:1, in addition to a water-insoluble aglycone. 3. The aglycone was identified as a cholestane derivative containing an unusual Delta(24)-23-ketone system, two secondary hydroxyl groups and an olefinic double bond, and had the molecular formula C(27)H(42)O(3). 4. The rates of release of sugars and sulphate suggested that fucose was at the non-reducing end of the oligosaccharide, with glucose glycosidically linked to the steroid. The sulphate group appeared to be linked to the other hydroxyl group of the steroid.