Prevalence and distribution of coronary artery calcium in a southeast asian cohort

Funding Acknowledgements

Type of funding sources: None.

Background

The coronary artery calcium score (CACS) independently predicts the risk of cardiovascular disease and major adverse cardiovascular events. While previous studies have demonstrated regional and ethnic differences in coronary calcification, the distribution of CACS in Southeast Asian (SEA) adults has not been investigated.

Purpose

The aim of this study was to determine CACS distribution in a SEA cohort living in Singapore.

Methods

This study involved 4945 asymptomatic patients who underwent CT coronary angiography and calcium scoring as part of screening for cardiovascular disease. Similar to the MESA study, patients with diabetes were analyzed separately due an increased prevalence of coronary calcification. A nonparametric analytical approach was used to determine CACS distribution stratified by age, gender and ethnicity.

Results

A positive CACS was seen in 43.7% of the overall SEA cohort with a higher prevalence in males (45.2%) than females (36.7%). The onset and burden of coronary calcification was also earlier and more severe in male subjects. There were no significant differences in CACS distribution amongst the three major ethnic groups in our study (p = 0.177). The presence of coronary calcification (CACS >0) was associated with increasing age, male gender and hypertension. Ethnicity, dyslipidemia, smoking and a family history of coronary artery disease did not significantly affect the presence of CACS.

Conclusions

This study provides a reference CACS distribution in an asymptomatic SEA population. There were no significant differences in CACS distribution amongst the three major ethnic groups living in Singapore.

Clinical characteristics and outcomes of myocardial infarction with nonobstructive coronary arteries

Background

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is caused by a heterogenous group of conditions with clinically significant sequelae.

Purpose

This study aims to compare the clinical characteristics and prognosis of MINOCA with myocardial infarction with obstructive coronary artery disease (MICAD).

Methods

Data was obtained from the Singapore Cardiac Longitudinal Outcomes Database (SingCLOUD), a national multicenter registry of patients with cardiovascular disease. Patients with a first presentation of acute myocardial infarction who underwent coronary angiography between 1 January 2011 and 31 December 2014 were extracted from the database. Follow up was conducted until 31 December 2017. Subjects were classified as having either MICAD or MINOCA based on angiographic findings. The primary outcomes were all-cause mortality and major adverse cardiac events (MACE) defined as a composite of all-cause mortality, recurrent myocardial infarction, hospitalization for heart failure and ischemic stroke.

Results

All 4124 patients who met the inclusion criteria were included in this study, of which 159 (3.9%) were diagnosed with MINOCA. Patients with MINOCA were more likely to be female, present with a non-ST elevation myocardial infarction (NSTEMI), have a higher left ventricular ejection fraction and less likely to have diabetes mellitus, previous ischemic stroke or smoking history. Over a mean follow-up duration of 4.5 years, MINOCA patients had a lower incidence of all-cause mortality (10.1% vs. 16.5%, p=0.030) and MACE (20.8% vs. 35.5%, p<0.0001) compared to patients with MICAD. On multivariable analysis, patients with MINOCA had a significantly lower risk of all-cause mortality (HR 0.42; 95% CI 0.21–0.82; p=0.011), MACE (HR 0.42; 95% CI 0.26–0.69; p=0.001) and recurrent myocardial infarction (HR 0.35; 95% CI 0.15–0.85; p=0.021). Within the MINOCA group, older age, higher creatinine, a STEMI presentation and the absence of antiplatelet use predicted all-cause mortality and MACE.

Conclusions

While patients with MINOCA had better clinical outcomes compared to MICAD patients, MINOCA is not a benign entity with about one in five patients experiencing a major adverse cardiovascular event in the mid-term.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Medical Research Council Project Grant

A prospective cohort study to determine the relationship between serum infliximab concentration and efficacy in patients with luminal Crohn's disease

BACKGROUND

Patients with Crohn's disease (CD) may experience disease relapse on maintenance infliximab. Anti-drug antibodies likely contribute to loss of response, and serum infliximab levels likely correlate with efficacy.

AIM

To prospectively evaluate the relationship between trough serum infliximab concentration and disease activity.

METHODS

Adult patients (N = 327) with a diagnosis of CD who had received at least five consecutive infliximab infusions and who planned to receive at least two additional infusions were enrolled. The Crohn's Disease Activity Index (CDAI), serum infliximab, C-reactive protein (CRP) and antibodies-to-infliximab (ATI) were assessed at baseline, week 4 and week 8. Receiver operating characteristic (ROC) analysis examined the relationship between infliximab concentrations and disease activity.

RESULTS

The mean CDAI score, which decreased 1.05 points between infusions, did not correlate with the mean change in trough infliximab concentration (+0.39 μg/mL; r = 0.099, P = 0.083), but was associated with the mean change in CRP concentration (r = 0.19, P < 0.001). Trough infliximab concentrations below 2.8-4.6 μg/mL best predicted a ≥ 70 point increase in the CDAI between infusions, and those below 2.7-2.8 μg/mL best predicted CRP >5 mg/mL at the second infusion. ATI at either visit decreased the proportion of patients with therapeutic infliximab trough levels compared with patients who were ATI negative (17.5% vs. 77.3% at visit 1 and 13.8% vs. 75.6% at visit 3; P < 0.001 for both comparisons).

CONCLUSIONS

This prospective study confirms the relationship between trough infliximab concentrations, inflammation and antibodies-to-infliximab. Infliximab trough concentrations below 3 μg/mL may increase the likelihood of symptoms and inflammation (ClinicalTrials.gov identifier: NCT00676988).

High-resolution measurements of small field beams using polymer gels

Small field sizes are increasingly becoming important in radiotherapy particularly since the introduction of intensity-modulated radiation therapy (IMRT) techniques. It is normally a challenging task to reliably measure the delivered dose and to determine its distribution in a medium for such small fields using conventional-type dosimeters such as gas ionisation chambers. Recently, attempts have been made to use films, but they are not tissue equivalent, they measure the dose only in two dimensions and they are not as responsive to radiations. In the present work, polyacrylamide gel (PAG) dosimeters are employed to measure the dose and its distribution in three dimensions for very small field sizes, such as those typically used in stereotactic radiosurgery. Field sizes of 6 x 6 and 18 x 18 mm in width are investigated. The results show an agreement with radiochromic film and ionisation diode measurements, with some variation in measured doses near the edge of the field, where the gel data decreases more rapidly than the other methods.

Modulation of gonadotropin II release by K+ channel blockers in goldfish gonadotropes: a novel stimulatory action of 4-aminopyridine

The effects of K+ channel blockers on basal gonadotropin II (GTH-II) release were examined in cultured goldfish gonadotropes. Tetraethylammonium (TEA) inhibited basal GTH-II release, whereas 4-aminopyridine (4-AP) increased basal release, although both K+ channel blockers generated increases in [Ca2+]i. Other K+ channel blockers had no significant effect on GTH-II release. We examined whether Ca2+ entry that arises from blockade of K+ channels by 4-AP mediates the secretory response. Secretion evoked by 4-AP was slightly reduced by TEA but was unaffected by reducing Ca2+ entry using either an inhibitor of Ca2+ channels, verapamil, or nominally Ca2+-free medium. In contrast, the Ca2+ signal evoked by 4-AP was largely blocked by Ca2+-free medium, as predicted by its inhibitory action on K+ channels. Together, these data suggest that the hormone release response to 4-AP is independent of entry of extracellular Ca2+. Finally, the mechanism of hormone release evoked by 4-AP appeared to be independent of mechanism(s) evoked by caffeine since 4-AP did not affect caffeine-evoked release and caffeine did not affect 4-AP evoked release. That both 4-AP and TEA generated Ca2+ signals but affected hormone release in either an extracellular Ca2+ independent (4-AP) or inhibitory (TEA) manner suggests that Ca2+ entry is linked to GTH-II secretion in a highly nonlinear fashion.

Shaping cocaine abstinence by successive approximation

Cocaine-using methadone-maintenance patients were randomized to standard contingency management (abstinence group, n = 49) or to a contingency designed to increase contact with reinforcers (shaping group, n = 46). For 8 weeks, both groups earned escalating-value vouchers based on thrice-weekly urinalyses: The abstinence group earned vouchers for cocaine-negative urines only; the shaping group earned vouchers for each urine specimen with a 25% or more decrease in cocaine metabolite (first 3 weeks) and then for negative urines only (last 5 weeks). Cocaine use was lower in the shaping group, but only in the last 5 weeks, when the response requirement was identical. Thus, the shaping contingency appeared to better prepare patients for abstinence. A 2nd phase of the study showed that abstinence induced by escalating-value vouchers can be maintained by a nonescalating schedule, suggesting that contingency management can be practical as a maintenance treatment.

Shaping cocaine abstinence by successive approximation

Cocaine-using methadone-maintenance patients were randomized to standard contingency management (abstinence group, n = 49) or to a contingency designed to increase contact with reinforcers (shaping group, n = 46). For 8 weeks, both groups earned escalating-value vouchers based on thrice-weekly urinalyses: The abstinence group earned vouchers for cocaine-negative urines only; the shaping group earned vouchers for each urine specimen with a 25% or more decrease in cocaine metabolite (first 3 weeks) and then for negative urines only (last 5 weeks). Cocaine use was lower in the shaping group, but only in the last 5 weeks, when the response requirement was identical. Thus, the shaping contingency appeared to better prepare patients for abstinence. A 2nd phase of the study showed that abstinence induced by escalating-value vouchers can be maintained by a nonescalating schedule, suggesting that contingency management can be practical as a maintenance treatment.

Transfusion practice in elective orthopaedic surgery

. The transfusion requirements of 2233 patients who underwent total hip or knee joint arthroplasty procedures at nine Canadian hospitals during 1995-1996 were evaluated. Although 64% of patients were eligible for participation in an autologous blood donation (ABD) programme, only 8% predonated blood. Patients who were eligible for ABD were younger (62 years vs. 70 years) and had fewer medical illnesses (18% vs. 44%) than those who did not predonate. The rate of allogeneic transfusion was 9.0% (95% confidence interval 4.9-13.1%) in patients who predonated as compared with 24.1% (95% confidence interval 22.2-25.9%) in those who did not. Risk factors for the occurrence of an allogeneic transfusion were type of procedure (primary or revision hip arthroplasty), lower baseline haemoglobin, lower body weight, older age and presence of rheumatoid arthritis (P < 0.001). Only patients without risk factors were predicted to have a less than 10% risk of receiving an allogeneic transfusion. Use of preventive strategies was minimal. Two models designed to predict the occurrence of an allogeneic transfusion were evaluated. If allogeneic transfusion rates are to be reduced, eligible patients should be encouraged to participate in ABD programmes. For patients who are ineligible, other preventative strategies should be introduced.

Signal transduction mechanisms mediating secretion in goldfish gonadotropes and somatotropes

The intracellular signal transduction mechanisms mediating maturational gonadotropin and somatotropin secretion in goldfish are reviewed. Several major signaling mechanisms, including changes in intracellular [Ca2+], arachidonic acid cascades, protein kinase C, cyclic AMP/protein kinase A, calmodulin, nitric oxide, and Na+/H+ antiport, are functional in both cell types. However, their relative importance in mediating basal secretion and neuroendocrine-factor-regulated hormone release differs according to cell type. Similarly, agonist- and cell-type-specificity are also present in the transduction pathways leading to neuroendocrine factor-modulated maturational gonadotropin and somatotropin release. Specificity is present not only in the actions of different regulators within the same cell type and with the same ligand in the two cell types, but this also exists between isoforms of the same neuroendocrine factor within a single cell type. Other evidence suggests that function-selectivity of signaling may also result from differential modulation of Ca2+ fluxes from different sources. The interaction of different second messenger systems provide the basis by which regulation of maturational gonadotropin and somatotropin release by multiple neuroendocrine factors can be integrated at the target cell level.

Caffeine stores and dopamine differentially require Ca(2+) channels in goldfish somatotropes

The regulation of growth hormone (GH) secretion by intracellular Ca(2+) stores was studied in dissociated goldfish somatotropes. We characterized a caffeine-activated intracellular store that had been shown to mediate GH release in response to gonadotropin-releasing hormone. The peak response of caffeine stimulation was reduced by approximately 28% by 100 microM ryanodine in a use-dependent manner suggesting that the first 10 min of GH release is partially mediated by a caffeine-activated ryanodine receptor. The temporal sensitivities of caffeine- and dopamine-evoked GH release to blockade of Cd(2+)-sensitive Ca(2+) channels were compared. We demonstrated that the initial phase of dopamine-evoked release was dependent on Ca(2+) channels, whereas the initial phase of caffeine-evoked release was sensitive only to pretreatment blockade. This would suggest that the maintenance of one class of caffeine-activated intracellular stores requires entry of Ca(2+) through Cd(2+)-sensitive Ca(2+) channels. This differential temporal requirement for Ca(2+) channels in Ca(2+) signaling may be a mechanism to segregate intracellular signaling pathways of multiple neuroendocrine regulators in the teleost pituitary.

Agonist-specific Ca2+ signaling systems, composed of multiple intracellular Ca2+ stores, regulate gonadotropin secretion

Ca2+ signals regulate many cellular functions, including hormone secretion. Agonist-specific Ca2+ signaling may arise from the differential mobilization of multiple Ca2+ stores. Although they act through the same receptor subtype, two gonadotropin-releasing hormones (sGnRH and cGnRH-II) generate quantifiably different Ca2+ signals in goldfish gonadotropes, suggesting that their Ca2+-dependent signaling cascades may differ. We combined electrophysiology, Ca2+ imaging, and radioimmunoassay detection of gonadotropin (GTH-II) secretion to determine the role of intracellular Ca2+ stores in GnRH-stimulated exocytosis. Our findings suggest that voltage-gated Ca2+ channels do not mediate acute GnRH-signaling. Instead, both sGnRH- and cGnRH-II-stimulated GTH-II releases are dependent on Ca2+ mobilized from TMB-8/CPA-sensitive compartments. However, sGnRH, but not cGnRH-II, utilizes intracellular stores sensitive to caffeine and xestospongin C. We also identified a homeostatic mechanism where reduced extracellular Ca2+ availability increase GTH-II release by mobilizing Ca2+ stores. Our results are the first to suggest that several classes of intracellular Ca2+ stores differentially participate in agonist signaling and homeostasis in gonadotropes.

Erythropoietin with iron supplementation to prevent allogeneic blood transfusion in total hip joint arthroplasty. A randomized, controlled trial

BACKGROUND

The optimum regimen of epoetin alfa for prevention of allogeneic blood transfusion is unknown.

OBJECTIVE

To determine whether a modified regimen of epoetin alfa reduces allogeneic blood transfusion in patients undergoing hip arthroplasty.

DESIGN

Randomized, double-blind, multicenter trial comparing two modified dose regimens of epoetin alfa with placebo.

SETTING

13 teaching hospitals and 4 community hospitals in Canada.

PATIENTS

201 patients undergoing primary hip arthroplasty who had a hemoglobin concentration of 98 to 137 g/L and did not predonate blood.

INTERVENTION

Patients were assigned in a 3:5:5 ratio to receive four weekly doses of epoetin alfa, 40 000 U (high-dose; n = 44) or 20 000 U (low-dose; n = 79), or placebo (n = 78), starting 4 weeks before surgery. All patients received oral iron supplementation, 450 mg/d, for 42 or more days before surgery.

MEASUREMENTS

The primary end point was allogeneic transfusion. Secondary end points were thromboembolic events and change in reticulocyte count and hemoglobin concentration.

RESULTS

Both modified epoetin alfa regimens significantly reduced the need for allogeneic transfusion: Five (11.4%) patients in the high-dose group (P = 0.001) and 18 (22. 8%) patients in the low-dose group (P = 0.003) had transfusion, compared with 35 (44.9%) patients in the placebo group. The hematologic response was substantial in patients who received epoetin alfa. In the high-dose group, low-dose group, and placebo group, the preoperative increase in reticulocyte count was 58.8, 37. 0 and 1.8 x 10(9) cells/L (P < 0.001), respectively, and the increase in hemoglobin concentration was 19.5, 17.2, and 1.2 g/L (P < 0.001). The incidence of thromboembolic events did not differ among groups.

CONCLUSIONS

Both modified epoetin alfa regimens were effective compared with placebo in reducing allogeneic transfusion in patients undergoing hip arthroplasty. Patients who received high-dose epoetin alfa had the lowest transfusion rate.

Predictors of symptom resolution in patients with community-acquired pneumonia

Previous studies have demonstrated that a substantial number of patients with community-acquired pneumonia (CAP) experienced CAP-related symptoms up to 3 months after the completion of antibiotic treatment. We evaluated the frequency of symptoms in a cohort of 535 patients with CAP who presented to a hospital emergency department and completed symptom questionnaires 2 and 6 weeks after the completion of a course of antibiotic therapy. Six weeks after cessation of antibiotic therapy, 64% of patients still reported > or = 1 CAP-related symptoms. Exploratory analyses were performed to identify potential predictors of complete symptom resolution. Logistic regression analysis identified younger age, absence of asthma or chronic obstructive pulmonary disease, and levofloxacin treatment as predictors of complete symptom resolution (all P < .05). Randomized controlled trials should be performed to evaluate the relative efficacy of different antibiotic therapies on the rate of resolution of symptoms.

Intravenous cocaine decreases cardiac vagal tone, vagal index (derived in lorenz space), and heart period complexity (approximate entropy) in cocaine abusers

We assessed the effects of i.v. cocaine on parasympathetic and sympathetic nervous system activity, and on the complexity vs. regularity of changes in heart rate over time. Fourteen otherwise healthy men with histories of i.v. cocaine abuse received bolus injections of cocaine (20 mg or 40 mg) and placebo (saline) on different days. Cardiovascular measures derived from the electrocardiogram, including heart rate, Porges' vagal tone (respiratory sinus arrhythmia), the 0.10 Hz rhythm, Toichi's vagal index, Toichi's sympathetic index, and approximate entropy (ApEn), were measured continuously. As predicted, cocaine produced tachycardia, accompanied by pronounced decreases in response to 40 mg cocaine in two different vagal tone indexes that precisely mirrored the increases in heart rate. The measure of sympathetic (and vagal) neural influences on the heart (0.10 Hz wave) also decreased in response to cocaine. Converging evidence from Toichi's vagal index supported the conclusion that the tachycardia from cocaine was due to withdrawal of cardiac vagal tone. These findings, and evidence that cocaine decreased cardiovascular complexity, contradict the prevailing assumption that the mechanism by which cocaine produces tachycardia is sympathetic (beta-adrenergic). We discuss implications for cardiac arrhythmias associated with cocaine abuse and death due to overdose.

Monitoring opiate use in substance abuse treatment patients with sweat and urine drug testing

Although urine testing remains the standard for drug use monitoring, sweat testing for drugs of abuse is increasing, especially in criminal justice programs. One reason for this increase is sweat testing may widen the detection window compared to urine testing. Drug metabolites are rapidly excreted in urine limiting the window of detection of a single use to a few days. In contrast, sweat collection devices can be worn for longer periods of time. This study was designed to compare the efficacy of sweat testing versus urine testing for detecting drug use. Paired sweat patches that were applied and removed weekly on Tuesdays were compared to 3-5 consecutive urine specimens collected Mondays, Wednesdays, and Fridays (355 matched sweat and urine specimen sets) from 44 patients in a methadone-maintenance outpatient treatment program. All patches (N = 925) were extracted in 2.5 mL of solvent and analyzed by ELISA immunoassay for opiates (cutoff concentration 10 ng/mL). A subset (N = 389) of patches was analyzed by gas chromatography-mass spectrometry (GC-MS). Urine specimens (N = 1886) were subjected to qualitative analysis by EMIT (cutoff 300 ng/mL). Results were evaluated to (1) determine the identity and relative amounts of opiates in sweat; (2) assess replicability in duplicate patches; (3) compare ELISA and GC-MS results for opiates in sweat; and (4) compare the detection of opiate use by sweat and urine testing. Opiates were detected in 38.5% of the sweat patches with the ELISA screen. GC-MS analysis confirmed 83.4% of the screen-positive sweat patches for heroin, 6-acetylmorphine, morphine, and/or codeine (cutoff concentration 5 ng/mL) and 90.2% of the screen-negative patches. The sensitivity, specificity, and efficiency of ELISA opiate results as compared to GC-MS results in sweat were 96.7%, 72.2%, and 89.5%, respectively. Heroin and/or 6-acetylmorphine were detected in 78.1% of the GC-MS-positive sweat patches. Median concentrations of heroin, 6-acetylmorphine, morphine, and codeine in the positive sweat samples were 10.5, 13.6, 15.9, and 13.0 ng/mL, respectively. Agreement in paired sweat patch test results was 90.6% by ELISA analysis. For the purposes of this comparison of ELISA sweat patch to EMIT urine screening for opiates, the more commonly used urine test was considered to be the reference method. The sensitivity, specificity, and efficiency of sweat patch results to urine results for opiates were 68.6%, 86.1%, and 78.6%, respectively. There were 13.5% false-negative and 7.9% false-positive sweat results as compared to urine tests. Analysis of sweat patches provides an alternate method for objectively monitoring drug use and provides an advantage over urine drug testing by extending drug detection times to one week or longer. In addition, identification of heroin and/or 6-acetylmorphine in sweat patches confirmed the use of heroin in 78.1% of the positive cases and differentiated illicit heroin use from possible ingestion of codeine or opiate-containing foods. However, the percentage of false-negative results, at least in this treatment population, indicates that weekly sweat testing may be less sensitive than thrice weekly urine testing in detecting opiate use.

A comparison of methotrexate with placebo for the maintenance of remission in Crohn's disease. North American Crohn's Study Group Investigators

BACKGROUND

Patients with Crohn's disease often have relapses. Better treatments are needed for the maintenance of remission. Although methotrexate is an effective short-term treatment for Crohn's disease, its role in maintaining remissions is not known.

METHODS

We conducted a double-blind, placebo-controlled, multicenter study of patients with chronically active Crohn's disease who had entered remission after 16 to 24 weeks of treatment with 25 mg of methotrexate given intramuscularly once weekly. Patients were randomly assigned to receive either methotrexate at a dose of 15 mg intramuscularly once weekly or placebo for 40 weeks. No other treatments for Crohn's disease were permitted. We compared the efficacy of treatment by analyzing the proportion of patients who remained in remission at week 40. Remission was defined as a score of 150 or less on the Crohn's Disease Activity Index.

RESULTS

Forty patients received methotrexate, and 36 received placebo. At week 40, 26 patients (65 percent) were in remission in the methotrexate group, as compared with 14 (39 percent) in the placebo group (P=0.04; absolute reduction in the risk of relapse, 26.1 percent; 95 percent confidence interval, 4.4 percent to 47.8 percent). Fewer patients in the methotrexate group than in the placebo group required prednisone for relapse (11 of 40 [28 percent] vs. 21 of 36 [58 percent], P=0.01). None of the patients who received methotrexate had a severe adverse event; one patient in this group withdrew because of nausea.

CONCLUSIONS

In patients with Crohn's disease who enter remission after treatment with methotrexate, a low dose of methotrexate maintains remission.

Treatment and outcomes of community-acquired pneumonia at Canadian hospitals

BACKGROUND

Community-acquired pneumonia is a common disease with a large economic burden. We assessed clinical practices and outcomes among patients with community-acquired pneumonia admitted to Canadian hospitals.

METHODS

A total of 20 hospitals (11 teaching and 9 community) participated. Data from the charts of adults admitted during November 1996, January 1997 and March 1997 were reviewed to determine length of stay (LOS), admission to an intensive care unit and 30-day in-hospital mortality. Multivariate analyses examined sources of variability in LOS. The type and duration of antibiotic therapy and the proportion of patients who were treated according to clinical practice guidelines were determined.

RESULTS

A total of 858 eligible patients were identified; their mean age was 69.4 (standard deviation 17.7) years. The overall median LOS was 7.0 days (interquartile range [IQR] 4.0-11.0 days); the median LOS ranged from 5.0 to 9.0 days across hospitals (IQR 6.0-7.8 days). Only 22% of the variability in LOS could be explained by known factors (disease severity 12%; presence of chronic obstructive lung disease or bacterial cause for the pneumonia 2%; hospital site 7%). The overall 30-day mortality was 14.1% (95% confidence interval [CI] 11.8%-16.6%); 13.6% of the patients were admitted to an intensive care unit (95% CI 11.4%-16.1%). The median duration of intravenous antibiotic therapy was 5 days (range 3.0-6.5 days across hospitals). Although 79.8% of patients received treatment according to clinical practice guidelines, the rate of compliance with the guidelines ranged from 47.9% to 100% across hospitals.

INTERPRETATION

Considerable heterogeneity exists in the management of community-acquired pneumonia at Canadian hospitals, the causes of which are poorly understood.

Contingent reinforcement increases cocaine abstinence during outpatient treatment and 1 year of follow-up

This study assessed whether contingent incentives can be used to reinforce cocaine abstinence in dependent outpatients. Seventy cocaine-dependent outpatients were randomized into 2 conditions. All participants received 24 weeks of treatment and 1 year of follow-up. The treatment provided to all participants combined counseling based on the community reinforcement approach with incentives in the form of vouchers exchangeable for retail items. In 1 condition, incentives were delivered contingent on cocaine-free urinalysis results, whereas in the other condition incentives were delivered independent of urinalysis results. Abstinence-contingent incentives significantly increased cocaine abstinence during treatment and 1 year of follow-up compared with noncontingent incentives.

A controlled trial of a critical pathway for treatment of community-acquired pneumonia. CAPITAL Study Investigators. Community-Acquired Pneumonia Intervention Trial Assessing Levofloxacin

CONTEXT

Large variations exist among hospitals in the use of treatment resources for community-acquired pneumonia (CAP). Lack of a common approach to the diagnosis and treatment of CAP has been cited as an explanation for these variations.

OBJECTIVE

To determine if use of a critical pathway improves the efficiency of treatment for CAP without compromising the well-being of patients.

DESIGN

Multicenter controlled clinical trial with cluster randomization and up to 6 weeks of follow-up.

SETTING

Nineteen teaching and community hospitals in Canada.

PATIENTS

A total of 1743 patients with CAP presenting to the emergency department at 1 of the participating institutions between January 1 and July 31, 1998.

INTERVENTION

Hospitals were assigned to continue conventional management (n = 10) or implement the critical pathway (n = 9), which consisted of a clinical prediction rule to guide the admission decision, levofloxacin therapy, and practice guidelines.

MAIN OUTCOME MEASURES

Effectiveness of the critical pathway, as measured by health-related quality of life on the Short-Form 36 Physical Component Summary (SF-36 PCS) scale at 6 weeks; and resource utilization, as measured by the number of bed days per patient managed (BDPM).

RESULTS

Quality of life and the occurrence of complications, readmission, and mortality were not different for the 2 strategies; the 1-sided 95% confidence limit of the between-group difference in the SF-36 PCS change score was 2.4 points, which was within a predefined 3-point boundary for equivalence. Pathway use was associated with a 1.7-day reduction in BDPM (4.4 vs 6.1 days; P = .04) and an 18% decrease in the admission of low-risk patients (31% vs 49%; P = .01). Although inpatients at critical pathway hospitals had more severe disease, they required 1.7 fewer days of intravenous therapy (4.6 vs 6.3 days; P = .01) and were more likely to receive treatment with a single class of antibiotic (64% vs 27%; P<.001).

CONCLUSION

In this study, implementation of a critical pathway reduced the use of institutional resources without causing adverse effects on the well-being of patients.

Contingent reinforcement increases cocaine abstinence during outpatient treatment and 1 year of follow-up

This study assessed whether contingent incentives can be used to reinforce cocaine abstinence in dependent outpatients. Seventy cocaine-dependent outpatients were randomized into 2 conditions. All participants received 24 weeks of treatment and 1 year of follow-up. The treatment provided to all participants combined counseling based on the community reinforcement approach with incentives in the form of vouchers exchangeable for retail items. In 1 condition, incentives were delivered contingent on cocaine-free urinalysis results, whereas in the other condition incentives were delivered independent of urinalysis results. Abstinence-contingent incentives significantly increased cocaine abstinence during treatment and 1 year of follow-up compared with noncontingent incentives.

Electrical stimulation of the preoptic area in Eigenmannia: evoked interruptions in the electric organ discharge

The functional role of the basal forebrain and preoptic regions in modulating the normally regular electric organ discharge was determined by focal brain stimulation in the weakly electric fish, Eigenmannia. The rostral preoptic area, which is connected with the diencephalic prepacemaker nucleus, was examined physiologically by electrical stimulation in a curarized fish. Electrical stimulation of the most rostral region of the preoptic area with trains of relatively low intensity current elicits discrete bursts of electric organ discharge interruptions in contrast to other forebrain loci. These responses were observed primarily as after-responses following the termination of the stimulus train and were relatively immune to variations in the stimulus parameters. As the duration and rate of these preoptic-evoked bursts of electric organ discharge interruptions (approximately 100 ms at 2 per s) are similar to duration and rate of natural interruptions, it is proposed that these bursts might be precursors to natural interruptions. These data suggest that the preoptic area, consistent with its role in controlling reproductive behaviors in vertebrates, may be influencing the occurrence of electric organ discharge courtship signals by either direct actions on the prepacemaker nucleus or through other regions that are connected with the diencephalic pre-pacemaker nucleus.