SCREENING FOR ALCOHOLISM IN GENERAL MEDICAL PATIENTS

Medical patients (N = 108) were administered a brief screeninginstrument (LAMSI) and a structured diagnostic interview (SUDDS).Twenty-five patients met DSM-III criteria for an alcohol usedisorder, 20 current, five in remission. The four-item scaleembedded in the screen identified the alcoholics with 88% sensitivityand 96% specificity.     

Application of an Allosteric Ternary Complex Model to the Technique of Pharmacological Resultant Analysis

A simple ternary complex model of drug-receptor interaction has been used to extend the procedure of pharmacological resultant analysis, enabling the quantitation of interactions between allosteric modulators and orthosteric antagonists. Equations derived in the theoretical treatment were used to analyse functional data for the interaction between the allosteric modulator gallamine and the orthosteric antagonist scopolamine, with oxotremorine as the agonist, at rat tracheal muscarinic acetylcholine receptors. Quantitative estimates of the affinity of gallamine for the allosteric site (pK_Z = 4.7) and the extent of negative, heterotropic co-operativity between gallamine and scopolamine (α′ = 13.1) were obtained. Furthermore, an alternative direct, model-fitting approach, that does not rely on the determination of concentration ratios, was also developed, and yielded similar results. It is suggested that the approach presented in this paper is useful for quantifying interactions between orthosteric antagonists and allosteric modulators, particularly when the extent of co-operativity is low or the modulators possess multiple pharmacological properties, or both.     

Identification of Babesia bigemina infected erythrocyte surface antigens containing epitopes conserved among strains

The presence of previously uncharacterized antigens (new antigens) on the surface of intact erythrocytes infected with three strains of Babesia bigemina from Kenya and one each from Puerto Rico, Mexico, St. Croix, and Texcoco-Mexico was demonstrated by indirect immunofluorescent antibody (IFA) reactions. These antigens were not strain specific because antibodies in bovine immune serum to either the Mexico or Kenya isolates reacted with all seven strains tested. Homologous and heterologous immune serum antibodies bound a maximum of 83% and 55%, respectively, of intact erythrocytes infected with the Kenya-Ngong strain but not uninfected erythrocytes. Both sera caused agglutination of only infected erythrocytes. Antibodies eluted from the surface of glutaraldehyde (0.25%) fixed infected erythrocytes had IFA reaction patterns among strains similar to those of immune sera before elation. Eluted antibodies were used to determine if these antigens were protein and encoded by B. bigemina. Eluted antibodies bound seven parasite-encoded proteins of 240, 220, 66, 62, 58, 52 and 38 kDa in an erythrocyte surfacespecific immunoprecipitation reaction of ³⁵-methionine labelled proteins. It was concluded that the surface of B. bigemina infected erythrocytes had parasite-encoded proteins and that these proteins had surface exposed epitopes that were conserved among the seven strains examined which were from two continents.     

Titration of Power Output During Radiofrequency Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia

Radiofrequency lesions in the anterior, superior aspect of the tricuspid annulus result in selective elimination of fast pathway function in patients with typical atrioventricular (AV) nodal reentry tachycardia. This technique is simple and effective, but has been associated with a significant risk of inadvertent complete AV block. The purpose of this study was to compare the safety and effectiveness of two different techniques for radiofrequency catheter ablation of the fast AV nodal pathway. Initially, a fixed power output was used at each target site. This method was compared retrospectively to a newer technique where power output was gradually incremented at each site. Radiofrequency power was initially applied at 10 watts for 10–15 seconds. If no junctional ectopy or a change in PR intervoi was seen, power output was incremented by 2 to 4 watts every 10 to 15 seconds up to a maximum of 30 watts. Thirty seven of 38 (96%) patients treated using this incremental power output were cured of their AV nodal reentry tachycardia. None of these patients developed inadvertent complete AV block. In contrast, 92% of historic controls treated with a fixed power output between 20 and 30 watts achieved a primary success and nine of these 89 (10%) historic controls developed inadvertent complete AV block (P = 0.04). There was no difference in the amplitudes of atrial, His, or ventricular electrograms at the effective sites between the two groups. Conclusions: (1) the anterior approach to radiofrequency catheter ablation of typical AV nodal reentry is associated with a significant risk of inadvertent complete AV block if a fixed power output is used; (2) starting at low power and gradually incrementing the output during radiofrequency energy application reduces the risk of complete AV block; (3) this incremental technique does not compromise efficacy.     

Radiofrequency Catheter Ablation of AtypicalAtrioventricular Nodal Reentrant Tachycardia

Ablation of Atypical Atrioventricular Nodal Reentrant Tachycardia, Introduction: Published reports of radiofrequency ablation of atypical atrioventricular nodal reentranttacbycardia (AVNRT) have been limited. We present our experience in 10 consecutive patientswith atypical AVNRT wbo underwent radiofrequency ablation of the "slow" AV nodal pathway.
Methods and Resttlts: there were 9 females and 1 male; their mean age was 44 ± 19 years (± SD), the mean AVNRT cycle length and ventriculoatrial (VA) interval at the His positionduring AVNRT were 340 ± 50 msec and 200 ± 70 msec, respectively. the slow pathway wassuccessfully ablated in all patients with a mean of 10 ± 7 radiofrequency energy applications inthe posteroseptal right atritim near the coronary sinus os. The mean procedure duration was 100 ± 35 minutes. There were no complications. In 4 patients, target sites were identified during sinus rhythm by mapping for possible slow pathway potentials, In the other 6 patients, target sites were identified by mapping retrograde atrial activation during AVNRT or ventricularpacing, The VA times at successful target sites were a mean of 45 ± 30 msec less tban the VAtime at the His cathetcr during AVNRT, There were no differences in success rate, number ofradiofrequency energy applications, or procedure duration between patients in whom mappingwas guided by possible slow pathway potentials or by retrograde atrial activation, During 6 ± 3 months of followup, 1 patient bad a recurrence of atypical AVNRT and underwent a secondablation procedure, which was successful.
Conclusion: Radiofrequency ablation of atypical AVNRT can be safely and effectivelyaccomplisbed when target sites are identified based either on possible slow pathway potentialsduring sinus rbytbm or retrograde atrial activation times during tachycardia.     

First 24 Hours of Acute Pancreatitis

Differences in metabolic Iiomeostasis in 12 patients with initial vs. eight patients with repeated attacks of acute pancreatitis have been compared during the acute phase of the disease. As a group, subjects vvitli a previous history of pancreatitis had significantly lower glucagon concfiitrations (P < 0.002) for the over all 24-hour study period. Conversely, the serum concentrations of blood sugar, insulin. growth hormone, gastrin, cortisol. nonesterified fatty acids, triglycerides and cholesterol failed to distinguish between the two patient groups. Likewise, immunoreactive plasma parathyroid hormone and calcitonin levels were comparable in both patient populations. Of the measurements considered. it would appear therefore that plasma immunoreactive glucagon is the best indicator of previous pancreatic inflanunation. Evaluation of parenchymal integrity during an episode of acute pancreatitis would he ol prognostic therapeutic value in this disease.     

Radiofrequency Ablation of Idiopathic Left Anterior Fascicular Tachycardia

Left Anterior Fascicular Tachycardia. Introduction: A 45-year-old man with idiopathic ventricular tachycardia (VT) having a right bundle branch block configuration with right-axis deviation underwent au electrophysiologic test.
Methods and Results: Mapping demonstrated a site on the auterobasal wall of the left ventricle where there was an excellent pace map and an endocardial activation time of -20 msec, hut radiofrequency catheter ablation at this site was unsuccessful. At a nearby site, a presumed Purkinje potential preceded the QRS complex by 30 msec during VT and sinus rhythm, and catheter ablation was effective despite a poor pace map and an endocardial ventricular activation time of zero.
Conclusion: Idiopathic VT with a right bundle branch configuration and right-axis deviation may originate in the area of the left anterior fascicle. A potential presumed to represent a Purkinje potential may he more helpful than endocardial ventricular activation mapping or pace mapping in guiding ablation of this type of VT.     

Differential Effect of Adenosine on Anterograde and Retrograde Fast Pathway Conduction in Patients with Atrioventricular Nodal Reentrant Tachycardia

Adenosine and Retrograde Fast Pathway Conduction . Introduction : Several studies have shown that the fast pathway is more responsive to adenosine than the slow pathway in patients with AV nodal reentrant tachycardia. Little information is available regarding the effect of adenosine on anterograde and retrograde fast pathway conduction.
Methods and Results : The effects of adenosine on anterograde and retrograde fast pathway conduction were evaluated in 116 patients (mean age 47 ± 16 years) with typical AV nodal reentrant tachycardia. Each patient received 12 mg of adenosine during ventricular pacing at a cycle length 20 msec longer than the fast pathway VA block cycle length and during sinus rhythm or atrial pacing at 20 msec longer than the fast pathway AV block cycle length. Anterograde block occurred in 98% of patients compared with retrograde fast pathway block in 62% of patients ( P < 0.001). Unresponsiveness of the retrograde fast pathway to adenosine was associated with a shorter AV block cycle length (374 ± 78 vs 333 ± 74 msec, P < 0.01), a shorter VA block cycle length (383 ± 121 vs 307 ± 49 msec, P < 0.001), and a shorter VA interval during tachycardia (53 ± 23 vs 41 ± 17 msec, P < 0.01).
Conclusion : Although anterograde fast pathway conduction is almost always blocked by 12 mg of adenosine, retrograde fast pathway conduction is not blocked by adenosine in 38% of patients with typical AV nodal reentrant tachycardia. This indicates that the anterograde and retrograde fast pathways may be anatomically and/or functionally distinct. Unresponsiveness of VA conduction to adenosine is not a reliable indicator of an accessory pathway.