Some practical perspectives for educating gifted children

This article identifies common characteristics of educationally related programs that form a common basis for understanding and working with gifted programs. Special approaches and programs for educational enrichment as well as specific activities that have been successful are discussed.     

Conversion of Ouabain-Induced Ventricular Tachycardia in Dogs with Epicardial Lidocaine: Pharmacodynamics and Functional Effects

Epicardial antiarrhythmic drug administration was studied as a therapeutic approach for experimental ventricular tachycardia (VT) in an open-chest dog model. Lidocaine-polyurethane matrices (28%, w/w) were formulated as a model system. Matrices were placed on the left ventricular epicardium in each of 23 anesthetized open-chest dogs with ouabain-induced VT, to evaluate effectiveness in restoring sinus rhythm. Conversion occurred in all animals treated with matrices containing 300 mg or more of lidocaine after 1.5 to 7.0 min. The matrix lidocaine content correlated linearly with the time required for conversion to sinus rhythm (r = 0.75, P = 0.0002); irrespective of matrix size the myocardial/plasma lidocaine ratio was 20.1 ± 4.2 (mean ± SD) at the time of conversion. In a separate series of five dogs without ventricular tachycardia, systolic wall thickening measured with sonomicrometers after 5 min of controlled-release lidocaine administration (500- to 1000-mg matrix lidocaine content, 7.48 ± 3.49-mg/kg dose) was only minimally diminished (–14.1%) and this effect was observed only at the site of matrix placement on the anterior-apical epicardium. In contrast, intracoronary injection of 0.3 or 1.0 mg/kg of lidocaine-HCl resulted in complete elimination of wall thickening or replacement by systolic thinning. Thus epicardial administration of lidocaine from polyurethane matrices was an effective means of treating ouabain-induced ventricular tachycardia. Regional myocardial function in the vicinity of the matrices was modified to a very limited degree, supporting the view that the matrices can be used safely, without serious risk to ventricular contractile performance.     

Stimulus functions of drugs and the assessment of abuse liability

The development of a unifying framework for conceptualizing the commonalities in various forms of substance abuse must encompass the data base focused upon the stimulus functions of drugs. In the first instance, for example, the research on drug self-administration has provided convincing evidence of a remarkable concordance between laboratory animals and human substance abusers in the reinforcing stimulus functions of a range of chemical agents. The recognition of these cross-species and cross-drug generalities has radically changed conceptualizations of substance abuse from a reactive to a more active process and has encouraged the kind of functional analysis of drug-seeking and drug-taking that has proven productive and useful in the study of other behavioral interactions. In this regard as well, recent refinements in the analysis of the discriminative stimulus functions of drugs have provided a more comprehensive basis for characterizing a chemical agent's spectrum of action and evaluating its abuse liability. While the correlation between the discriminative stimulus functions and the reinforcing stimulus functions is remarkably high for some drug classes, there are notable exceptions. Finally, the assessment of abuse liability requires an analysis of the eliciting stimulus functions of drugs as reflected by the physiological and behavioral changes, both acute and chronic, that follow drug administration. The methods used to evaluate both physiological dependence and behavioral toxicity in relationship to sensory and motor effects for a range of abused drugs have depended heavily upon an assessment of the eliciting stimulus functions of such compounds.     

Relationship of "bleeding on probing" and "gingival index bleeding" as clinical parameters of gingival inflammation

Abstract Bleeding on probing (BOP) and the gingival index have been used to clinically characterize the degree of gingival inflammation. It is, however, unclear to what extent these parameters correlate to each other and to probing pocket depth (PD). The purpose of this clinical study was to evaluate the association between BOP and GI bleeding (scores of 2 and 3), as well as the relationship of these variables to PD, in a group of patients presenting with naturally-occurring gingivitis. Based on screening examinations of 125 subjects with at least 20 teeth, no more than 4 sites with PD over 6 mm, a BOP frequency of 30% or greater, and no systemic condition that would influence the inflammatory response, were selected. 2 weeks after screening they were examined at 6 sites per tooth for plaque index, GI, PD and BOP. A standardized pressure sensitive probe (Florida Probe) with 20 g probing force was used for BOP and PD measurements. In this population, means of 40.9% (S.E.= 1.36) BOP sites and 35.3% (S.E, = 1.81) GI bleeding sites per patient were found. A total of 20,008 sites ranging in PD up to 5.9 mm were evaluated; however, the majority of sites (19,723, 98.6%) presented with <4 mm PD. When sites were evaluated, BOP demonstrated a positive correlation with PD, whereas GI bleeding correlated with PH. For sites characterized by the absence of BOP as well as the absence of GI bleeding (scores 0 and 1), the highest % of agreement between the 2 indices (77.7%) was found in shallow sites (0.1–2 mm). In contrast, when sites presenting with both BOP and GI bleeding were analyzed, the highest % of agreement (85,4%) was found for sites with PD >4.0 mm. In this gingivitis population group, it appears that BOP and GI bleeding evaluate distinct inflammatory1 conditions of the gingival tissues, and the relationship between the 2 clinical parameters may vary according to PD at the individual site examined.     

Venous Irritation Related to Intravenous Administration of Phenytoin versus Fosphenytoin

Study Objective . To compare the frequency, severity, and time course of venous irritation after administration of a single intravenous dose of phenytoin with an equimolar dose of fosphenytoin, a water-soluble phenytoin prodrug. Design . Randomized, double-blind, two-period, crossover study. Setting . University hospital clinical research unit. Patients . Twelve healthy volunteers within 15% of ideal body weight and with no clinically significant abnormalities on physical examination, medical history, or laboratory assessment. Interventions . Volunteers randomly received a 30-minute infusion of phenytoin sodium 250 mg (250 mg/5 ml) or an equimolar dose of fosphenytoin 375 mg (375 mg/5 ml). Subjects returned for the crossover treatment 14–21 days later. Measurements and Main Results . Subjects assessed venous irritation (pain, burning, itching), and investigators evaluated phlebitis (erythema, swelling, tenderness), induration, exudation, and cording. Phenytoin was associated with a significantly higher degree of pain at the infusion site in all subjects and a significant degree of phlebitis in eight subjects (p<0.05); cording occurred in six subjects. The time course of phenytoin-induced phlebitis was bimodal. Erythema and tenderness were prominent at the end of the infusion and again at 24 hours. Cording was first noted between 24 hours and 1 week after infusion. In contrast, fosphenytoin was associated with mild pain in two subjects, one incident of phlebitis, and no erythema or cording. Conclusions . Fosphenytoin administration resulted in significantly less venous irritation and phlebitis compared with an equimolar dose of phenytoin. The clinical use of this water-soluble phenytoin prodrug should minimize the frequency and severity of infusion-site reactions and should allow convenient, rapid, intravenous administration of drug, undiluted or admixed with intravenous solutions.     

Phase II evaluation of merbarone in renal cell carcinoma

Summary The Southwest Oncology Group (SWOG) studied the response rate and toxicity of merbarone (1,000 mg/m² IV continuous infusion days 1–5, q 21 days) in patients with advanced metastatic renal cell carcinoma. Among 36 eligible patients, there was one partial response for a response rate of 3% (95% C.I. 0.1–15%). There were no mixed responses. There were no treatment related deaths or adverse drug reactions. Significant anemia, diarrhea, and hypercalcemia were observed. Mild to moderate degrees of malaise/fatigue/lethargy, dizziness/vertigo, hyperglycemia, creatinine increase, nausea, vomiting, weight loss, pedal edema, dyspnea, and granulocytopenia were noted. Merbarone does not have significant activity as a single agent in advanced renal cell carcinoma.     

The effect of cigarette smoke on the bovine lens

Smoking has recently been identified from epidemiological studies as a possible cause of cataract but the mechanism involved is not known. Therefore, our laboratory has initiated studies aimed at elucidating these mechanisms. Whole bovine lenses were cultured to examine possible effects of cigarette smoke on amino acid uptake and protein synthesis. Cigarette smoke, filtered to remove nicotine and tar which would not reach the eye in vivo, was bubbled through culture medium. Bovine lenses were incubated in this medium in the presence of [¹⁴C]-leucine for four days. A significant decrease in uptake of [¹⁴C]-leucine and a decrease in protein synthesis were found with smoke treated lenses. This is the first demonstration of an effect of cigarette smoke on the lens. Further work is needed to determine how this metabolic upset is mediated and how it could lead to cataract.