Predicting patient outcomes after treatment with immune checkpoint blockade: A review of biomarkers derived from diverse data modalities

Immune checkpoint blockade (ICB) therapy targeting cytotoxic T-lymphocyte-associated protein 4, programmed death 1, and programmed death ligand 1 has shown durable remission and clinical success across different cancer types. However, patient outcomes vary among disease indications. Studies have identified prognostic biomarkers associated with immunotherapy response and patient outcomes derived from diverse data types, including next-generation bulk and single-cell DNA, RNA, T cell and B cell receptor sequencing data, liquid biopsies, and clinical imaging. Owing to inter- and intra-tumor heterogeneity and the immune system's complexity, these biomarkers have diverse efficacy in clinical trials of ICB. Here, we review the genetic and genomic signatures and image features of ICB studies for pan-cancer applications and specific indications. We discuss the advantages and disadvantages of computational approaches for predicting immunotherapy effectiveness and patient outcomes. We also elucidate the challenges of immunotherapy prognostication and the discovery of novel immunotherapy targets.

Tutorial: integrative computational analysis of bulk RNA-sequencing data to characterize tumor immunity using RIMA

RNA-sequencing (RNA-seq) has become an increasingly cost-effective technique for molecular profiling and immune characterization of tumors. In the past decade, many computational tools have been developed to characterize tumor immunity from gene expression data. However, the analysis of large-scale RNA-seq data requires bioinformatics proficiency, large computational resources and cancer genomics and immunology knowledge. In this tutorial, we provide an overview of computational analysis of bulk RNA-seq data for immune characterization of tumors and introduce commonly used computational tools with relevance to cancer immunology and immunotherapy. These tools have diverse functions such as evaluation of expression signatures, estimation of immune infiltration, inference of the immune repertoire, prediction of immunotherapy response, neoantigen detection and microbiome quantification. We describe the RNA-seq IMmune Analysis (RIMA) pipeline integrating many of these tools to streamline RNA-seq analysis. We also developed a comprehensive and user-friendly guide in the form of a GitBook with text and video demos to assist users in analyzing bulk RNA-seq data for immune characterization at both individual sample and cohort levels by using RIMA.

Hippo Signaling Pathway Regulates Cancer Cell-Intrinsic MHC-II Expression

MHC-II is known to be mainly expressed on the surface of antigen-presenting cells. Evidence suggests MHC-II is also expressed by cancer cells and may be associated with better immunotherapy responses. However, the role and regulation of MHC-II in cancer cells remain unclear. In this study, we leveraged data mining and experimental validation to elucidate the regulation of MHC-II in cancer cells and its role in modulating the response to immunotherapy. We collated an extensive collection of omics data to examine cancer cell-intrinsic MHC-II expression and its association with immunotherapy outcomes. We then tested the functional relevance of cancer cell-intrinsic MHC-II expression using a syngeneic transplantation model. Finally, we performed data mining to identify pathways potentially involved in the regulation of MHC-II expression, and experimentally validated candidate regulators. Analyses of preimmunotherapy clinical samples in the CheckMate 064 trial revealed that cancer cell-intrinsic MHC-II protein was positively correlated with more favorable immunotherapy outcomes. Comprehensive meta-analyses of multiomics data from an exhaustive collection of data revealed that MHC-II is heterogeneously expressed in various solid tumors, and its expression is particularly high in melanoma. Using a syngeneic transplantation model, we further established that melanoma cells with high MHC-II responded better to anti-PD-1 treatment. Data mining followed by experimental validation revealed the Hippo signaling pathway as a potential regulator of melanoma MHC-II expression. In summary, we identified the Hippo signaling pathway as a novel regulator of cancer cell-intrinsic MHC-II expression. These findings suggest modulation of MHC-II in melanoma could potentially improve immunotherapy response.

Machine learning on syngeneic mouse tumor profiles to model clinical immunotherapy response

Most patients with cancer are refractory to immune checkpoint blockade (ICB) therapy, and proper patient stratification remains an open question. Primary patient data suffer from high heterogeneity, low accessibility, and lack of proper controls. In contrast, syngeneic mouse tumor models enable controlled experiments with ICB treatments. Using transcriptomic and experimental variables from >700 ICB-treated/control syngeneic mouse tumors, we developed a machine learning framework to model tumor immunity and identify factors influencing ICB response. Projected on human immunotherapy trial data, we found that the model can predict clinical ICB response. We further applied the model to predicting ICB-responsive/resistant cancer types in The Cancer Genome Atlas, which agreed well with existing clinical reports. Last, feature analysis implicated factors associated with ICB response. In summary, our computational framework based on mouse tumor data reliably stratified patients regarding ICB response, informed resistance mechanisms, and has the potential for wide applications in disease treatment studies.

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

TISMO: syngeneic mouse tumor database to model tumor immunity and immunotherapy response

Syngeneic mouse models are tumors derived from murine cancer cells engrafted on genetically identical mouse strains. They are widely used tools for studying tumor immunity and immunotherapy response in the context of a fully functional murine immune system. Large volumes of syngeneic mouse tumor expression profiles under different immunotherapy treatments have been generated, although a lack of systematic collection and analysis makes data reuse challenging. We present Tumor Immune Syngeneic MOuse (TISMO), a database with an extensive collection of syngeneic mouse model profiles with interactive visualization features. TISMO contains 605 in vitro RNA-seq samples from 49 syngeneic cancer cell lines across 23 cancer types, of which 195 underwent cytokine treatment. TISMO also includes 1518 in vivo RNA-seq samples from 68 syngeneic mouse tumor models across 19 cancer types, of which 832 were from immune checkpoint blockade (ICB) studies. We manually annotated the sample metadata, such as cell line, mouse strain, transplantation site, treatment, and response status, and uniformly processed and quality-controlled the RNA-seq data. Besides data download, TISMO provides interactive web interfaces to investigate whether specific gene expression, pathway enrichment, or immune infiltration level is associated with differential immunotherapy response. TISMO is available at http://tismo.cistrome.org.

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.

Two endogenous gonadotropin-releasing hormones generate dissimilar Ca(2+) signals in identified goldfish gonadotropes

Ca(2+) signals are involved in the signal transduction of neuroendocrine regulators. In goldfish, two endogenous gonadotropin-releasing hormones, salmon (s)GnRH and chicken (c)GnRH-II, control maturational gonadotropin secretion. Although considerable evidence suggests that sGnRH and cGnRH-II exert their activity on goldfish gonadotropes through a single population of receptors, differences in signal transduction mechanisms between these peptides have been demonstrated. We used ratiometric Fura-2 Ca(2+) imaging of single morphologically identified gonadotropes to quantitatively compare the Ca(2+) signals evoked by sGnRH and cGnRH-II. The amplitude and the rate of rise of sGnRH- and cGnRH-II-evoked Ca(2+) signals increased with concentration. At maximal concentrations, Ca(2+) signals generated by cGnRH-II rose significantly faster than those elicited by sGnRH, while other parameters such as the maximum amplitude, average Ca(2+) increase, and latency did not differ between the two peptides. Ca(2+) signals evoked by sGnRH or cGnRH-II were often spatially restricted to one part of the cell over the duration of the response. We provide a comprehensive account of the spatial and temporal aspects, including calculated kinetics, of GnRH-evoked Ca(2+) signals in single identified gonadotropes. This is the first report of quantified differences in Ca(2+) signals generated by two endogenous GnRH neuropeptides, which may act through the same receptor population in this cell type.

Monitoring cocaine use in substance-abuse-treatment patients by sweat and urine testing

Sweat and urine specimens were collected from 44 methadone-maintenance patients to evaluate the use of sweat testing to monitor cocaine use. Paired sweat patches that were applied and removed weekly (on Tuesdays) were compared with 3-5 consecutive urine specimens collected Mondays, Wednesdays, and Fridays. All patches (N = 930) were extracted in 2.5 mL of solvent and analyzed by ELISA immunoassay (cutoff concentration 10 ng/mL); a subset of patches (N = 591) was also analyzed by gas chromatography-mass spectrometry (GC-MS) for cocaine, benzoylecgonine (BZE), and ecgonine methyl ester (EME) (cutoff concentration 5 ng/mL). Urine specimens were subjected to qualitative analysis by EMIT (cutoff 300 ng/mL) and subsets were analyzed by TDx (semiquantitative, LOD 30 ng/mL) and by GC-MS for cocaine (LOD 5 ng/mL). Results were evaluated to (1) determine the relative amounts of cocaine and its metabolites in sweat; (2) assess replicability in duplicate patches; (3) compare ELISA and GC-MS results for cocaine in sweat; and (4) compare the detection of cocaine use by sweat and urine testing. Cocaine was detected by GC-MS in 99% of ELISA-positive sweat patches; median concentrations of cocaine, BZE, and EME were 378, 78.7, and 74 ng/mL, respectively. Agreement in duplicate patches was approximately 90% by ELISA analysis. The sensitivity, specificity, and efficiency of sweat ELISA cocaine results as compared with sweat GC-MS results were 93.6%, 91.3%, and 93.2%, respectively. The sensitivity, specificity, and efficiency between ELISA sweat patch and EMIT urine results were 97.6%, 60.5%, and 77.7%, respectively. These results support the use of sweat patches for monitoring cocaine use, though further evaluation is needed.

Adults seeking treatment for marijuana dependence: a comparison with cocaine-dependent treatment seekers

Sixty-two individuals seeking treatment for marijuana dependence completed a comprehensive assessment. Sociodemographics, substance use, psychosocial functioning, psychiatric symptoms, and medical status were compared with similar data collected from 70 treatment-seeking, cocaine-dependent individuals. Substantial psychosocial and psychiatric problems were observed in both groups. In general, the marijuana group reported substance-use histories and a range of impairment comparable with the cocaine group; however, they showed less severe dependence. The marijuana group was more ambivalent and less confident about stopping their marijuana use than the cocaine group was about stopping their cocaine use. These findings indicate that treatment-seeking, marijuana-dependent individuals exhibit substantial problems and that further efforts to develop effective treatments for this population are warranted.

Broad beneficial effects of cocaine abstinence reinforcement among methadone patients

Escalating reinforcement for sustained abstinence has been effective in treating cocaine abuse. Under this schedule, patients receive vouchers for cocaine-free urine samples; vouchers have monetary values that increase with the number of consecutive cocaine-free urine samples. Cocaine-abusing methadone patients were randomly assigned to receive vouchers for 12 weeks under (a) an escalating schedule (n = 20), (b) an escalating schedule with start-up bonuses (n = 20), or (c) a noncontingent schedule (n = 19). Start-up bonuses were designed to provide added reinforcement for initiating abstinence; however, they did not improve outcomes. Both contingent interventions significantly increased cocaine abstinence. In addition, the contingent interventions increased abstinence from opiates and decreased reports of cocaine craving. These results replicate the efficacy of cocaine abstinence reinforcement and show that it can have broad beneficial effects.

Broad beneficial effects of cocaine abstinence reinforcement among methadone patients

Escalating reinforcement for sustained abstinence has been effective in treating cocaine abuse. Under this schedule, patients receive vouchers for cocaine-free urine samples; vouchers have monetary values that increase with the number of consecutive cocaine-free urine samples. Cocaine-abusing methadone patients were randomly assigned to receive vouchers for 12 weeks under (a) an escalating schedule (n = 20), (b) an escalating schedule with start-up bonuses (n = 20), or (c) a noncontingent schedule (n = 19). Start-up bonuses were designed to provide added reinforcement for initiating abstinence; however, they did not improve outcomes. Both contingent interventions significantly increased cocaine abstinence. In addition, the contingent interventions increased abstinence from opiates and decreased reports of cocaine craving. These results replicate the efficacy of cocaine abstinence reinforcement and show that it can have broad beneficial effects.

Lung function and general illness symptoms in a semiconductor manufacturing facility

Large quantities of potent gases, dopants, photoactive chemicals (photoresists, photoinitiators), solvents, and ionizing radiation are used in the semiconductor manufacturing process, but little is known about the occurrence of respiratory disease from exposures in this industry. The purpose of this study was to assess the pulmonary risk by conducting pulmonary function tests and symptoms survey in a semiconductor plant in Taiwan. This study is part of a clinical survey conducted on 926 workers in a semiconductor plant in Taiwan in July 1995. The study items included a standard self-administered questionnaire, chest x-rays, pulmonary function tests, and physical examinations in 249 workers. There was a borderline significance of higher prevalence (P = 0.06) of restrictive lung abnormality in male photolithographic workers (4 of 21; 19.1%) than in male control workers (0 of 17; 0%), and the smoking- and age-adjusted odds ratio was 4.1 (95% confidence interval [CI], 0.41-41.6). There was a significantly higher prevalence (P = 0.02) of restrictive lung abnormality in male ion-implantation workers (5 of 19; 26.3%) than in male control workers (0 of 17; 0%), and the smoking- and age-adjusted odds ratio was 3.7 (95% CI, 0.52-26.7). There were significantly higher prevalences of airway irritation, eye irritation, headache, stress, tiredness, and poor memory in female photolithographic or etch/diffusion workers than in control workers. This study suggests that restrictive lung abnormality is a potential health effect in male silicon-wafer fabrication workers in the semiconductor industry. The tasks of male process, maintenance, and equipment engineers put them at risk for intermittent short-term peak exposure. This may account for a higher prevalence of mild restrictive lung abnormality among male engineers of photolithographic and ionimplantation sections. The findings of this medical surveillance are tentative, but they suggest that further investigation of the etiologic factors and the subsequent health effects is necessary.

Photodynamic therapy for facial squamous cell carcinoma in cats using Photofrin

BACKGROUND

Photodynamic therapy (PDT) has been shown to be an effective treatment modality for surface-oriented neoplasms of the skin, respiratory, gastrointestinal, and urogenital systems. The purpose of our study was to assess the safety and efficacy of PDT using Photofrin in the treatment of squamous cell carcinomas of feline facial skin.

MATERIALS AND METHODS

Cats with naturally occurring squamous cell carcinomas of the skin were entered into the study. PDT was delivered to the tumors using an argon-pumped dye laser 48 hours after the administration of the photosensitizer porfimer sodium (Photofrin). Following treatment, the tumors were evaluated for complete response rates and local control durations.

RESULTS

Eight tumors were staged T1a, 9 staged T1b, and 14 staged T2b. Complete response rates as well as local control durations were significantly related to stage (p < 0.0001). Complete response was achieved in 100% of the T1a tumors and 53% of the T1b tumors; the overall 1-year local control rate for all treated tumors was 62%. Clinical, hematological, and biochemical evidence of toxicity was not seen in any cat following drug administration.

CONCLUSION

PDT with the photosensitizer Photofrin was safe and effective in treating early stage squamous cell carcinomas of the feline skin.

Connections of the basal forebrain of the weakly electric fish, Eigenmannia virescens

The organization of the ventral nucleus of the ventral telencephalon (Vv) was examined in the weakly electric fish, Eigenmannia virescens. This nucleus, which is considered the teleost homologue to the basal forebrain nuclei of other vertebrates, was subdivided into dorsal and ventral subdivisions, based upon cytoarchitectonic, immunohistochemical, and connectional criteria. Afferent projections were observed from the medial olfactory bulb as well as the terminal nerve ganglion. Telencephalic afferents to the Vv were very restricted, consisting of the supracommissural and the dorsal intermediate nuclei of the ventral telencephalon, the nucleus taenia, and the medial region of the posterior nucleus of the dorsal telencephalon. However, the major afferents to the Vv were diencephalic, particularly those originating from the rostral preoptic area and other hypothalamic nuclei. Additional afferents included the posterior tubercular nucleus, the locus coeruleus, the medial perilemniscal nucleus, and the periventricular nucleus of the posterior tuberculum. Relatively weak projections were observed from the ventral thalamus and the dorsal posterior thalamic nucleus. As described previously, the diencephalic complex of the central posterior thalamic nucleus/prepacemaker nucleus (CP/PPn), which also has cells that innervate the pacemaker circuitry controlling the production of an electric organ discharge, projects to the Vv. Terminal fields of the Vv were observed to be coextensive with afferent cell groups in the preoptic area, lateral and caudal hypothalamic nuclei, and thalamus. An additional efferent target of the Vv was the pretectal nucleus electrosensorius. That many cell groups that are connected with the Vv are also connected with the CP/PPn, particularly the preoptic and hypothalamic nuclei, suggests that the electrocommunicatory system is intimately linked with basal forebrain limbic pathways.

Afferent and efferent connections of the diencephalic prepacemaker nucleus in the weakly electric fish, Eigenmannia virescens: interactions between the electromotor system and the neuroendocrine axis

The afferent and efferent connections of the gymnotiform central posterior nucleus of the dorsal thalamus and prepacemaker nucleus (CP/PPn) were examined by retrograde and anterograde transport of the small molecular weight tracer, Neurobiotin. The CP/PPn was identified by physiological assay and received a local iontophoretic injection of Neurobiotin. Retrogradely labeled somata were observed in the ventral telencephalon, hypothalamus, and the pretectal nucleus electrosensorius. Anterogradely labeled fibers were traced from the CP/PPn to the ventral telencephalon, the hypothalamus, the neuropil immediately adjacent to the most rostral subdivision of the nucleus electrosensorius, the optic tectum, and the pacemaker nucleus. Retrograde transport of tracer following injections into the ventral telencephalon, preoptic area, lateral hypothalamus, tectum, and pacemaker nucleus confirmed these efferent targets. A rostromedial subarea of the CP/PPn can be identified that projects to basal forebrain regions and to a lateral region of the CP/PPn that contains afferents to the pacemaker. Many of the targets, which are connected with the CP/PPn, have been linked to reproductive behavior or neuroendocrine control in other fishes. A comparative analysis reveals that the efferent pathways of the CP/PPn appear similar and may be homologous to efferent pathways of some components of the auditory thalamus among tetrapods.

Feline ocular epithelial response to growth factors in vitro

OBJECTIVE

To examine the proliferative abilities of growth factors known to participate in wound healing on feline lens, iris pigment, ciliary, and retinal pigment epithelium cultured in vitro.

ANIMALS

8 clinically normal cats.

PROCEDURE

Iris pigment, lens, ciliary, and retinal pigment epithelia of normal eyes of cats were isolated and cultured. Morphologic characteristics of primary cell cultures were studied by light and electron microscopy. Subcultures of epithelial cells were exposed to media supplemented with 0.5% fetal bovine serum plus various combinations of insulin and/or growth factors, including transforming growth factor-alpha, epidermal growth factor, acidic fibroblast growth factor, and basic fibroblast growth factor. Growth promoting effects were evaluated by counting with an electronic cell counter.

RESULTS

Cells retained many of the morphologic characteristics of in vivo cells. Cell proliferation assays indicated that transforming growth factor-alpha stimulated lens and ciliary epithelial cell growth, and epidermal growth factor enhanced lens and iris pigment epithelial cell growth. Acidic fibroblast growth factor had proliferative effects on lens, iris pigment, and ciliary epithelium. Basic fibroblast growth factor was the most potent stimulator of all mitogens used, and caused substantial proliferation in all cell types. Insulin alone stimulated lens and ciliary epithelial proliferation but, combined with other growth factors, had a synergistic effect with those causing cell proliferation, except acidic fibroblast growth factor with iris pigment epithelium.

CONCLUSION

Morphologic studies support the argument that pigment-producing cells are involved in feline ocular sarcoma. Growth factor studies indicated that ciliary epithelium has the most profound proliferative effect of all growth factors used. These data may help guide future studies in determining the cell of origin for feline ocular sarcoma.

Motor control of the jamming avoidance response of Apteronotus leptorhynchus: evolutionary changes of a behavior and its neuronal substrates

The two closely related gymnotiform fishes, Apteronotus and Eigenmannia, share many similar communication and electrolocation behaviors that require modulation of the frequency of their electric organ discharges. The premotor linkages between their electrosensory system and their medullary pacemaker nucleus, which controls the repetition rate of their electric organ discharges, appear to function differently, however. In the context of the jamming avoidance response, Eigenmannia can raise or lower its electric organ discharge frequency from its resting level. A normally quiescent input from the diencephalic pre-pacemaker nucleus can be recruited to raise the electric organ discharge frequency above the resting level. Another normally active input, from the sublemniscal pre-pacemaker nucleus, can be inhibited to lower the electric organ discharge frequency below the resting level (Metzner 1993). In contrast, during a jamming avoidance response, Apteronotus cannot lower its electric organ discharge frequency below the resting level. The sublemniscal pre-pacemaker is normally completely inhibited and release of this inhibition allows the electric organ discharge frequency to rise during the jamming avoidance response. Further inhibition of this nucleus cannot lower the electric organ discharge frequency below the resting level. Lesions of the diencephalic pre-pacemaker do not affect performance of the jamming avoidance response. Thus, in Apteronotus, the sublemniscal pre-pacemaker alone controls the changes of the electric organ discharge frequency during the jamming avoidance response.

Does self-administration of a quality of life index for inflammatory bowel disease change the results?

We assessed the effect of self-administration of a disease-specific health-related quality of life instrument, the Inflammatory Bowel Disease Questionnaire (IBDQ), on score results. Patients were assessed at two visits in two tertiary centers. "Experienced" patients (N = 31) with Crohn's disease had previously completed the IBDQ several times while "novices" (N = 37) with Crohn's disease or ulcerative colitis had no prior exposure to the IBDQ. At each visit a self-administered IBDQ followed by a nurse-administered IBDQ (score range, 1-7; absolute score range, 32-224) and disease activity were assessed. At visit 1, the mean rates of discrepant responses between nurse and self-administered scores were 24 +/- 15% in experienced patients and 34 +/- 17% in novice patients (p = 0.018), which fell to 21 +/- 16 and 23 +/- 10%, respectively, by visit 2 (p = NS). However, discrepancy rates were not significantly different between novice and experienced patients when adjusted by center. Discrepancies occurred randomly in all 32 IBDQ items. Eighty percent of all discrepant responses differed by only one grade of a seven-point Likert scale. Baseline self-administered scores for all patients were 4.80 +/- 1.24 (absolute score, 153.0 +/- 39.9). Mean score differences at each visit (nurse minus self) were very small, ranging from 0.029 to 0.136, and would not be considered clinically important. Intraclass correlation coefficients between the nurse and self-administered IBDQ and the four dimensional scores were > or = 0.97 by visit 2, indicating excellent concordance and minimal observer error. Mean changes in score over time were of comparable magnitude for both self (0.320 +/- 0.819) and nurse (0.260 +/- 0.831) assessments. We conclude that the IBDQ may be reliably used as a self-administered instrument in clinical trials.

Increasing opiate abstinence through voucher-based reinforcement therapy

Heroin dependence remains a serious and costly public health problem, even in patients receiving methadone maintenance treatment. This study used a within-subject reversal design to assess the effectiveness of voucher-based abstinence reinforcement in reducing opiate use in patients receiving methadone maintenance treatment in an inner-city program. Throughout the study subjects received standard methadone maintenance treatment involving methadone, counseling, and urine monitoring (three times per week). Thirteen patients who continued to use opiates regularly during a 5-week baseline period were exposed to a 12-week program in which they received a voucher for each opiate-free urine sample provided: the vouchers had monetary values that increased as the number of consecutive opiate-free urines increased. Subjects continued receiving standard methadone maintenance for 8 weeks after discontinuation of the voucher program (return-to-baseline). Tukey's posthoc contrasts showed that the percentage of urine specimens that were positive for opiates decreased significantly when the voucher program was instituted. (P < or = 0.01) and then increased significantly when the voucher program was discontinued during the return-to-baseline condition (P < or = 0.01). Rates of opiate positive urines in the return-to-baseline condition remained significantly below the rates observed in the initial baseline period (P < or = 0.01). Overall, the study shows that voucher-based reinforcement contingencies can decrease opiate use in heroin dependent patients receiving methadone maintenance treatment.

Localization and developmental expression of surfactant proteins D and A in the respiratory tract of the mouse

Surfactant protein D (SP-D) is synthesized and secreted by pulmonary epithelial cells. Like surfactant protein A (SP-A), SP-D is a collagen-like glycoprotein belonging to the "collectin" class of C-type lectins that may play an important role in pulmonary host defense. To begin studies on SP-D gene regulation and function using the mouse as an animal model, we identified the cellular sites of SP-D gene expression in adult mouse lung and trachea and characterized the developmental expression of SP-D mRNA in murine fetal and newborn lungs. We compared these findings with similar studies for murine SP-A, which has an established role in surfactant function and metabolism and a probable role in pulmonary host defense. SP-D mRNA and protein were readily detected by in situ hybridization and immunocytochemistry in alveolar type II and nonciliated bronchiolar epithelial cells of the lung, as well as in cells of the tracheal epithelium and tracheal submucosal glands of the adult mouse. Although SP-A mRNA and protein were also localized to alveolar and nonciliated bronchiolar epithelial cells of the murine lung, there was no detectable labeling for either SP-A mRNA or protein in the murine trachea. Expression of murine SP-D mRNA was first detected by Northern blot analysis on d 16 of gestation in timed-pregnant mice, with an average gestational period of 17 d, and this increased dramatically before birth and during the immediate postnatal period. The developmental expression of murine SP-A mRNA paralleled that of SP-D except that there was a small decrease in mRNA content on postnatal d 5. These studies provide the first description of the cellular distribution and developmental expression of SP-D in mouse lung, which will be important for interpreting future studies of SP-D gene expression in transgenic animal models. In addition, these studies provide the first documentation that, unlike SP-A, SP-D is synthesized not only in the lung but also in submucosal glands of the trachea.

A randomized study of the influence of perfusion technique and pH management strategy in 316 patients undergoing coronary artery bypass surgery. I. Mortality and cardiovascular morbidity

The impact of perfusion technique and mode of pH management during cardiopulmonary bypass has not been well characterized with respect to postoperative cardiovascular outcome.

METHODS

This double-blind, randomized study comparing outcomes after alpha-stat or pH-stat management and pulsatile or nonpulsatile perfusion during moderate hypothermic cardiopulmonary bypass was undertaken in 316 patients undergoing coronary artery bypass operations.

RESULTS

Cardiovascular morbidity and mortality were not affected by pH management, and the incidence of stroke (2.5%) did not differ between groups. Overall in-hospital mortality was 2.8%, eight of the nine deaths occurring in the nonpulsatile group (5.1% versus 0.6%; p = 0.018). The incidence of myocardial infarction was 5.7% in the nonpulsatile group and 0.6% in the pulsatile group (p = 0.010), and use of intraaortic balloon pulsation was significantly more common in the nonpulsatile group (7.0% versus 1.9%; p = 0.029). The overall percentage of patients having major complications was also significantly higher in the nonpulsatile group (15.2% versus 5.7%; p = 0.006). Duration of cardiopulmonary bypass, age, and use of nonpulsatile perfusion all correlated significantly with adverse outcome.

CONCLUSIONS

Use of pulsatile perfusion during cardiopulmonary bypass was associated with decreased incidences of myocardial infarction, death, and major complications.

A randomized study of the influence of perfusion technique and pH management strategy in 316 patients undergoing coronary artery bypass surgery. II. Neurologic and cognitive outcomes

This double-blind, randomized comparison of pulsatile or nonpulsatile perfusion and alpha-stat or pH-stat management during cardiopulmonary bypass was designed to assess postoperative central nervous system outcomes.

METHODS

Neurologic and cognitive testing was conducted before the operation and 7 days and 2 months after the operation in 316 patients having coronary artery bypass and in a reference cohort of 40 patients having major vascular and thoracic operations.

RESULTS

As detailed in part I of this study, mortality in patients having coronary bypass was 2.8%. The incidence of stroke was 2.5% and did not differ among bypass groups. Mortality was 2.5% for the major surgery cohort. The incidence of cognitive (p = 0.003) and either neurologic or cognitive dysfunction (p = 0.0002) was higher at 7 days for the coronary bypass group than for the major surgery cohort. The incidence of neurologic dysfunction remained higher (p = 0.050) at 2 months in the coronary bypass group. Cognitive dysfunction at 2 months was less prevalent after 90 minutes of cardiopulmonary bypass in patients managed with alpha-stat than with pH-stat strategy (27% versus 44%, p = 0.047).

CONCLUSIONS

Postoperative central nervous system dysfunction is more prevalent in patients having coronary bypass than in those having major operations. Pulsatility has no effect on central nervous system outcomes, but alpha-stat management is associated with a decreased incidence of cognitive dysfunction in patients undergoing prolonged cardiopulmonary bypass.

Serial cranial and spinal cord magnetic resonance imaging in multiple sclerosis

Twenty-nine mildly disabled patients with multiple sclerosis underwent serial clinical and magnetic resonance imaging (MRI) evaluations (pre- and postgadolinium cranial and spinal cord MRI) on at least 3 occasions at 13-week intervals and during periods of suspected relapse. Using clinical judgment of the presence of recent active disease as the gold standard, combined MRI studies confirmed the clinical impression of active disease in 93% of follow-up visits (sensitivity) and the absence of active MS in 63% of follow-up visits (specificity). None of the cranial and spinal MRI-detected abnormalities disappeared. Gadolinium administration particularly increased the yield of spinal MRI. Cranial MRI alone detected 80% of the MRI-active visits. Clinical and MRI concordance was significantly better for the presence of recent disease activity than for the anatomical localization of the presumed site of activity. MRI evidence of apparent ongoing disease activity was seen more frequently in patients believed to have active multiple sclerosis in the preceding year (13 of 21) than in patients who had been in clinical remission for at least the 2 preceding years (2 of 8). Although clinical evidence of new disease activity was much less common in patients with active, chronic-progressive disease (1 of 8) than in patients with active, relapsing disease (9 of 13), the proportion of patients with either infrequent relapses, frequent relapses, or slow chronic-progressive disease in the preceding year in whom MRI activity developed and the pattern of this new MRI activity was similar between these types of active patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular responses to naloxone challenge in opiate-dependent individuals

Vagally mediated tachycardia appears to be a common response to abused drugs and, therefore, has implications for abuse liability. To test the specificity of this common factor, we determined whether the tachycardia to naloxone in opiate-dependent individuals has a significant vagal component. Naloxone challenge (0.4 mg, IM) in 19 opiate-dependent men and women was associated with highly reliable tachycardia, but no significant change in vagal tone index, a noninvasive measure of parasympathetic inhibitory control of the heart. We conclude that tachycardia during naloxone-precipitated withdrawal is not vagally mediated. Thus, there is some degree of specificity to the common factor of vagally mediated tachycardia to abused drugs because it was ruled out in at least one drug (naloxone) with aversive subjective effects.

Location of motoneurons innervating the middle ear muscle of the chicken, (Gallus domesticus)

The motoneuron pool for the musculus columellae, the avian equivalent to the m. stapedius, was identified by retrograde labeling with WGA-HRP. It consists of a discrete group of approximately 65 neurons located along the dorsolateral border in the ventral subnucleus of the facial nuclear complex. Other facial motoneurons were only labeled when diffusion of the tracer into neighbor structures was not excluded. The dorsal subnucleus of the facial nerve innervates the m. depressor mandibulae.

Clinical correlates of white-matter changes on magnetic resonance imaging scans of the brain

We report our observations on the clinical and radiologic correlates of changes in cerebral white matter based on 94 subjects undergoing magnetic resonance imaging in a prospective study of dementia. Periventricular hyperintensity occurred twice as often in patients with Alzheimer's disease as in healthy control subjects. Within the control group, the presence of periventricular hyperintensity correlated significantly with one measure of cerebral atrophy and with the presence of changes in the adjoining deep white matter. The significance of white-matter changes distinct from the ventricles (leuko-araiosis) remains unsettled. Leuko-araiosis on the magnetic resonance imaging scan, unlike its correlate on the computed tomographic scan, was not shown to relate to cognitive decline or to the presence of focal abnormalities on neurologic examination. This is likely to reflect the heterogeneity of the changes detected with magnetic resonance imaging and their limited extent in our subjects.

Improved recognition of leukoaraiosis and cognitive impairment in Alzheimer's disease

We identified 85 patients in a longitudinal study of dementia who had uncomplicated Alzheimer's disease and in whom computed tomography of the head and psychometric testing were conducted within a 6-month period following their entry into the study. Thirty-four patients (40%) had leukoaraiosis, which was disproportionately common in female patients (62% vs 15% in male patients). Analysis of covariance demonstrated a relative reduction of scores on the Extended Scale for Dementia in those patients who had leukoaraiosis, after adjusting for the confounding effects of age, sex, educational level, and duration of illness. Leukoaraiosis was also much more common in women, even after adjusting for the possible confounding effects of age, duration of illness, Extended Scale for Dementia score, and hypertension. Multiple regression analysis showed that leukoaraiosis accounted for 11.6% of the variance of the Extended Scale for Dementia scores. Leukoaraiosis, together with duration of illness, accounted for 18.2% of the variance. Leukoaraiosis is associated with a greater degree of cognitive impairment in patients with Alzheimer's disease.

Routine intrauterine insemination and the effect of spermatozoal washing as assessed by computer-assisted semen analyzer

We present the results from 283 cycles of intrauterine insemination (IUI) performed on 237 patients. Their indications for treatment included cervical factor infertility, spermatozoal antibodies, idiopathy, poor postcoital test, and oligozoospermia. Pregnancies arose in all groups, with 28 pregnancies from natural cycles, and 17 from clomiphene citrate-supplemented cycles. A live birth rate per cycle of 12.7% (36/283) was achieved following nine miscarriages. A further 133 patients, with only cervical factor or idiopathic infertility, underwent 144 cycles of IUI in natural cycles; this more homogeneous group had their spermatozoal performance monitored by a computer-assisted semen analyzer (CASA) before and after spermatozoal washing for IUI. All factors in the spermatozoal profile changed significantly after washing. Twelve clinical pregnancies resulted from these 144 cycles of IUI, and a comparison was made between the spermatozoal profiles, as assessed by CASA, of conceptual and nonconceptual cycles. Post-wash spermatozoal concentration was slightly greater (P less than .1) in the conceptual cycles, whilst spermatozoal velocity was significantly less (P less than .005). The relevance of these findings to the definition of a "hyperactivational" state for human spermatozoa is discussed, and the general applicability of IUI as a "frontline" treatment for nontubal infertility is proposed.