Psychostimulants in the treatment of adults with psychosis and attention deficit disorder

Whether conceptualized as comorbid ADD with psychosis or as a distinct diagnostic entity--ADD psychosis--patients with features of both ADD and psychosis benefit from treatment with psychostimulants. It is hypothesized that psychostimulants have their therapeutic effect via amelioration of frontal lobe dysfunction.

A randomized, double-blind comparison of intravenous diltiazem and digoxin for atrial fibrillation after coronary artery bypass surgery

BACKGROUND

Atrial fibrillation (AF) after coronary bypass graft surgery may result in hypotension, heart failure symptoms, embolic complications, and prolongation in length of hospital stay (LOHS). The purpose of this study was to determine whether intravenous diltiazem is more effective than digoxin for ventricular rate control in AF after coronary artery bypass graft surgery. A secondary end point was to determine whether ventricular rate control with diltiazem reduces postoperative LOHS compared with digoxin.

METHODS AND RESULTS

Patients with AF and ventricular rate > 100 beats/min within 7 days after coronary artery bypass graft surgery were randomly assigned to receive intravenous therapy with diltiazem (n = 20) or digoxin (n = 20). Efficacy was measured with ambulatory electrocardiography (Holter monitoring). Safety was assessed by clinical monitoring and electrocardiographic recording. LOHS was measured from the day of surgery. Data were analyzed with the intention-to-treat principle in all randomly assigned patients. In addition, a separate intention-to-treat analysis was performed excluding patients who spontaneously converted to sinus rhythm. In the analysis of all randomly assigned patients, those who received diltiazem achieved ventricular rate control (> or = 20% decrease in pretreatment ventricular rate) in a mean of 10 +/- 20 (median 2) minutes compared with 352 +/- 312 (median 228) minutes for patients who received digoxin (p < 0.0001). At 2 hours, the proportion of patients who achieved rate control was significantly higher in patients treated with diltiazem (75% vs 35%, p = 0.03). Similarly, at 6 hours, the response rate associated with diltiazem was higher than that in the digoxin group (85% vs 45%, p = 0.02). However, response rates associated with diltiazem and digoxin at 12 and 24 hours were not significantly different. At 24 hours, conversion to sinus rhythm had occurred in 11 of 20 (55%) patients receiving diltiazem and 13 of 20 (65%) patients receiving digoxin (p = 0.75). Results of the analysis of only those patients who remained in AF were similar to those presented above. There was no difference between the diltiazem-treated and digoxin-treated groups in postoperative LOHS (8.6 +/- 2.2 vs 7.7 +/- 2.0 days, respectively, p = 0.43).

CONCLUSIONS

Ventricular rate control occurs more rapidly with intravenous diltiazem than digoxin in AF after coronary artery bypass graft surgery. However, 12- and 24-hour response rates and duration of postoperative hospital stay associated with the two drugs are similar.

The central role of the CD40-ligand and CD40 pathway in T-lymphocyte-mediated differentiation of B lymphocytes

This review summarizes recent findings concerning the role of CD40-ligand and CD40 interactions in B-cell differentiation. CD40-ligand on helper CD4+ T lymphocytes interacts with CD40 on B cells and directs the selection and differentiation of clones of B lymphocytes to generate specific antibody-dependent immune responses. CD40-ligand is necessary for normal B-cell differentiation and plays several distinctive roles in this multistage process. The CD40 signaling pathway that normally regulates B-cell death appears to be usurped by the Epstein-Barr virus to mediate B-cell transformation.

Glycine binding to rat cortex and spinal cord: binding characteristics and pharmacology reveal distinct populations of sites

Glycine is the principal inhibitory neurotransmitter in posterior regions of the brain. In addition, glycine serves as an allosteric regulator of excitatory neurotransmission mediated by the N-methyl-D-aspartate (NMDA) acidic amino acid receptor subtype. The studies presented here characterize [3H]glycine binding to washed membranes prepared from rat spinal cord and cortex, areas enriched in glycine inhibitory and NMDA receptors, respectively, in an attempt to define the glycine recognition sites on the two classes of receptors. Specific binding for [3H]glycine was seen in both cortex and spinal cord. Saturation analyses in cortex were best fitted by a two-site model with respective equilibrium dissociation constants (KD values) of 0.24 and 5.6 microM and respective maximal binding constants (Bmax values) of 3.4 and 26.7 pmol/mg of protein. Similar analyses in spinal cord were best fitted by a one-site model with a KD of 5.8 microM and Bmax of 20.2 pmol/mg of protein. Na+ had no effect on [3H]glycine binding to cortical membranes but increased the binding to spinal cord membranes by greater than 15-fold. This Na+-dependent binding may reflect glycine binding to the recognition site of the high-affinity, Na+-dependent glycine uptake system. Several short-chain, neutral amino acids displaced [3H]glycine binding from both cortical and spinal cord membranes. The most potent displacers of [3H]glycine binding to cortical membranes were D-serine and D-alanine, followed by the L-isomers of serine and alanine and beta-alanine. In contrast, D-serine and D-alanine were similar in potency to L-serine in spinal cord membranes. Compounds active at receptors for the acidic amino acids had disparate effects on the binding of [3H]glycine. At 10 microM, NMDA resulted in a 25% increase, whereas D- and L-2-amino-5-phosphonovaleric acid at 100 microM resulted in a 30% decrease, in [3H]glycine binding to cortical membranes. Kynurenic acid was the most potent of the acidic amino acid-related compounds at displacing [3H]glycine binding. In cortical membranes, kynurenic acid displacement was resolved into a high- and a low-affinity component; the high-affinity component displaced the high-affinity component of [3H]glycine binding.(ABSTRACT TRUNCATED AT 400 WORDS)

Alteration of methylcholanthrene-mediated suppression of cutaneous delayed hypersensitivity by benzoflavone treatment of C57BL/6J mice

The potential role of the cytochromes P-450 in methylcholanthrene (MC)-mediated suppression of cutaneous delayed hypersensitivity (CDH) in C57BL/6J (B6) mice was evaluated indirectly by treating mice with agents known to induce or inhibit hepatic cytochromes P-450 prior to contact sensitization. Subsequent alterations in aryl hydrocarbon hydroxylase (AHH) activity and CDH, as measured by suppression of 2,4-dinitrofluorobenzene (DNFB)-induced ear swelling, were measured. MC administration resulted in a dose-dependent suppression of ear swelling and a concomitant dose-dependent induction of hepatic AHH activity. Treatment of B6 mice with phenobarbital (PB), 80 mg/kg daily X 3, a broad spectrum inducer of P-450, resulted in a 2.5-fold increase in benzo[a]pyrene (B[a]P) hydroxylase activity without affecting CDH. Animals treated with the same PB protocol prior to an ED20 dose of MC showed no difference in suppression of CDH compared to animals treated with MC alone. In contrast, successive treatment with the selective P1-450 inducer, 5,6-benzoflavone (beta NF), prior to and following an ED20 dose of MC significantly increased suppression of CDH (p less than 0.001) usually seen at this MC dose. Treatment with a known inhibitor of cytochrome P1-450 activity, 7,8-benzoflavone (alpha NF), did not prevent AHH induction when administered prior to and following MC (ED100) nor did it suppress CDH when administered alone. However, this alpha NF treatment completely prevented suppression of CDH usually seen at this MC dose. These data provide evidence suggesting that metabolic activation by cytochrome P1-450 is required for the expression of the immunosuppressive activity of MC.

Serial evaluation of left ventricular function in congestive heart failure by measurement of peak aortic blood acceleration

Peak acceleration of blood in the ascending aorta, an index of global systolic left ventricular (LV) function, can be measured noninvasively using a continuous wave Doppler velocimeter applied suprasternally. The feasibility of this approach as a tool for detecting improvement of LV function was studied in 16 patients with congestive heart failure (CHF). Measurements were made daily for 6 consecutive days. The daily variability of peak acceleration examined in 11 normal subjects was +/- 2 m/s/s. In 11 of 16 patients with CHF, peak acceleration increased more than 2 m/s/s by day 6 compared with day 1 (group 1). In 5 of 16 patients, peak acceleration remained unchanged (group 2). In group 1, peak acceleration was 11 +/- 1 m/s/s on day 1 and increased to 16 +/- 1 m/s/s on day 6 (p less than 0.001). In this group, CHF resolved by day 6 in 9 of 11 patients. In group 2, peak acceleration was 9 +/- 1 m/s/s on day 1 and remained unchanged through day 6. In these 5 patients, the signs and symptoms of CHF persisted through day 6. The results suggest that peak acceleration measured noninvasively with continuous wave Doppler can detect improvement of LV function in patients with CHF. The approach provides a simple and reliable bedside means for serial evaluation of LV systolic function.

Model study on the bioreduction of paraquat, MPP+, and analogs. Evidence against a "redox cycling" mechanism in MPTP neurotoxicity

The ability of paraquat, MPP+, and analogs to be reduced by chemical reductants and by NADPH, as catalyzed by liver microsomes or purified NADPH cytochrome P-450 reductase, is reported. The analogs span a range of electrochemical potential, including values in-between that of paraquat and MPP+. Analogs with an Eo below -.55 V (vs. NHE) are not reduced by either the NADPH-microsomes or NADPH-reductase systems. The inability of MPP+ to be bio-reduced or to stimulate the production of superoxide during aerobic reduction is evidence against a redox-cycling (oxidant stress) role of MPP+ in MPTP neurotoxicity.

Rate and extent of recovery of left ventricular function in patients following acute myocardial infarction

To determine the rate and extent of recovery of left ventricular (LV) performance following acute myocardial infarction (MI), peak aortic blood acceleration was measured serially in 26 patients and in 11 normal volunteers with a continuous wave Doppler placed suprasternally. In patients, Doppler measurements were made 20 +/- 2 hours after the acute onset of chest discomfort and were repeated daily for 6 consecutive days. Infarction patients were divided into two groups. Group I consisted of 15 patients who did not have a previous MI and whose present course was not complicated by congestive heart failure (CHF). Group II consisted of 11 patients who had either a previous MI or developed CHF during the present admission. Peak acceleration in the normal volunteers showed minimal daily variations over a period of 6 days. Peak acceleration in the entire group of 26 MI patients increased from 13 +/- 3 m/sec/sec on the day of admission (day 1) to 18 +/- 6 m/sec/sec on day 6 (p less than 0.001). In group I, peak acceleration increased from 13 +/- 4 to 20 +/- 6 m/sec/sec between day 1 and day 6 (p less than 0.001). In group II, however, peak acceleration was 12 +/- 2 m/sec/sec on day 1 and increased to only 15 +/- 4 m/sec/sec on day 6 (NS). These results indicate that LV performance, based upon peak acceleration of blood in the ascending aorta, improves markedly within 6 days in patients suffering their first MI uncomplicated by CHF.(ABSTRACT TRUNCATED AT 250 WORDS)

Two-dimensional echocardiographic assessment of infective endocarditis in children

We examined 11 children with infective endocarditis initially and serially by two-dimensional echocardiography. Nine (82%) of the 11 patients had echocardiographic findings at initial examination compatible with infective endocarditis. These results provided strong evidence in support of the diagnosis before bacteriologic confirmation was available. Congestive heart failure, major emboli, and/or the need for surgical intervention occurred in seven of the nine patients with positive two-dimensional echocardiograms. Echocardiographic evidence of vegetations persisted during antibiotic therapy and resolved slowly during many months. Serial echocardiograms were useful in cases in which obvious valve destruction or marked increase in vegetation size imaged echocardiographically could be combined with clinical evidence of progressive heart failure to support a decision for early surgical intervention. Two-dimensional echocardiography can make important contributions to the diagnosis and management of children with infective endocarditis.