A randomized clinical study to assess ingestion of dentifrice by children

This study investigated whether there was a difference in amounts of dentifrice ingested by children based on age using pea-sized instructions. The study had a randomized, single-blinded, 3-period, crossover design modelled after Barnhart et al. (1974) with one regular-flavored and two specially-flavored dentifrices used ad libitum. Subjects were enrolled in three groups: 2-4, 5-7, and 8-12 years. They were instructed to brush at home as they would normally with each dentifrice for 3 weeks (9 weeks total). On weekly study-site visits, subjects brushed with the assigned dentifrice containing a lithium marker to measure the amount of dentifrice ingested and used. Averaging across dentifrices, amounts ingested were: 0.205 g (2-4 yr), 0.125 g (5-7 yr) and 0.135 g (8-12 yr), demonstrating 2-4 year-olds ingested significantly more than older children (p ≤ 0.002). Averaging across dentifrices, amounts used were: 0.524 g (2-4 yr), 0.741 g (5-7 yr) and 0.978 g (8-12 yr) suggesting an age-related effect (p < 0.01). Findings also showed that ingestion amount for specially-flavored dentifrices may increase relative to regular-flavored dentifrice for children 2-7 years-old. This research demonstrated that dentifrice ingestion amount decreased significantly with age while usage amount increased with age. Importantly, ingestion and usage levels in younger children reflect "pea-sized" direction and were numerically lower than historical levels reported prior to this direction.

Effective half-life of caesium-137 in various environmental media at the Savannah river site

During the operational history of the Savannah River Site (SRS), many different radionuclides have been released from site facilities into the SRS environment. However, only a relatively small number of pathways, most importantly (137)Cs in fish and deer, have contributed significantly to doses and risks to the public. The "effective" half-lives (Te) of (137)Cs (which include both physical decay and environmental dispersion) in Savannah River floodplain soil and vegetation and in fish and white-tailed deer from the SRS were estimated using long-term monitoring data. For 1974-2011, the Tes of (137)Cs in Savannah River floodplain soil and vegetation were 17.0 years (95% CI = 14.2-19.9) and 13.4 years (95% CI = 10.8-16.0), respectively. These Tes were greater than in a previous study that used data collected only through 2005 as a likely result of changes in the flood regime of the Savannah River. Field analyses of (137)Cs concentrations in deer collected during yearly controlled hunts at the SRS indicated an overall Te of 15.9 years (95% CI = 12.3-19.6) for 1965-2011; however, the Te for 1990-2011 was significantly shorter (11.8 years, 95% CI = 4.8-18.8) due to an increase in the rate of (137)Cs removal. The shortest Tes were for fish in SRS streams and the Savannah River (3.5-9.0 years), where dilution and dispersal resulted in rapid (137)Cs removal. Long-term data show that Tes are significantly shorter than the physical half-life of (137)Cs in the SRS environment but that they can change over time. Therefore, it is desirable have a long period of record for calculating Tes and risky to extrapolate Tes beyond this period unless the processes governing (137)Cs removal are clearly understood.

Hyperthermic perfusion during cardiopulmonary bypass and postoperative temperature are independent predictors of acute kidney injury following cardiac surgery

Acute kidney injury (AKI) following cardiopulmonary bypass (CPB) is associated with increased mortality, requirement for dialysis, and longer intensive care unit (ICU) and hospital length of stay. Rewarming during CPB and poor oxygen delivery have been associated with AKI; however, the role of temperature management on AKI has not been clearly defined. This study aims to evaluate the role of hyperthermia during CPB and the temperature upon admission to the ICU on AKI following cardiac surgery, using the RIFLE (renal Risk, Injury, Failure, Loss of renal function and End-stage renal disease) criteria.

To determine whether CPB hyperthermia (measured as the cumulative time the arterial outlet temperature >37°C) and ICU admission temperature were independent risk factors for AKI, data from 1393 consecutive adult patients undergoing isolated on-pump coronary artery bypass graft (CABG), valve repair and/or replacement and valve/CABG procedures was analysed using a logistic multivariate model. After testing for interaction, we incorporated covariates having a p-value <0.1. AKI was defined according to the RIFLE criteria as an increase in serum creatinine >50% from baseline to peak value postoperatively. Overall, 12.3% of patients developed AKI with a 4.5-fold increase in in-hospital mortality. Variables found to be independent predictors of AKI included CPB hyperthermia (Odds ratio [OR] 1.03 per minute increase [95% confidence interval (CI) 1.01-1.05]; p = 0.01), ICU admission temperature ([OR] 1.44 per degree increase [(CI) 1.13-1.85]; p<0.001), minimum CPB haemoglobin ([OR] 0.83 per g/dL increase [(CI) 0.71-0.97]; p = 0.02), use of intra-aortic balloon pump ([OR] 2.69 [(CI) 1.24-5.82]; p = 0.01) and ICU readmission ([OR] 3.13 [(CI) 1.73-5.64]; p<0.001).

Avoiding arterial outlet hyperthermia may help decrease AKI following cardiac surgery using CPB. Both intraoperative and postoperative temperature management strategies should be the focus of future randomised studies to determine optimal interventions.

Effect of aripiprazole versus haloperidol on PANSS Prosocial items in early-episode patients with schizophrenia

BACKGROUND AND AIM

Improving social functioning is critically important in early-episode schizophrenia, if patients are to achieve functional recovery. This post-hoc, pooled analysis of two studies compared the effect of aripiprazole versus haloperidol on social functioning in early-episode schizophrenia.

METHODS

Data were pooled from two 52 week, randomized (2:1), double-blind, multicenter studies involving 1294 patients with chronic schizophrenia who were in an acute psychotic episode and had a history of positive antipsychotic response during previous episodes. The early-episode group was defined as patients who are <or=40 years of age with <or=5 years' duration of illness. Social functioning was assessed by mean change from baseline on the PANSS Prosocial subscale (ANCOVA and LOCF), comprising six PANSS items, and the Modified Prosocial subscale, comprising four PANSS items. Measurements were taken at approximately monthly intervals for up to 1 year.

RESULTS

Aripiprazole (n=237) demonstrated significant improvement versus haloperidol (n=123) as early as Week 18 on both the Prosocial subscale (-4.75 versus -3.78, p<0.05) and on the Modified Prosocial subscale (-3.16 versus -2.28, p<0.05). Patients receiving aripiprazole continued to show similar significant improvement versus haloperidol at all remaining timepoints through Week 52 using the Modified Prosocial subscale, but less consistent improvement with the Prosocial subscale. Significant advantage for the aripiprazole-treated patients was observed at Weeks 46 and 52 (endpoint) with both subscales.

CONCLUSION

In patients with early-episode schizophrenia, aripiprazole demonstrates greater improvement than haloperidol on PANSS items related to social functioning. The cognitive and functional implications of these findings remain to be clarified in future studies.

Continous quality improvement of perfusion practice: the role of electronic data collection and statistical control charts

In-hospital data collection may be used to improve the selection, operative techniques, and process of care for cardiac surgical patients. The aim of this report is to demonstrate the influence of the automated generation of quality indicators (QI) for cardiopulmonary bypass (CPB) and the implementation of a continuous quality improvement (CQI) programme on the CPB process of care. Adult patients undergoing CPB were divided into three consecutive groups: Group 1 (n=363); no QI data feedback, Group 2 (n = 253); automated QI data feedback alone, and Group 3 (n = 363) data feedback and implementation of CQI. There were no significant differences in demographic, procedural or clinical outcomes for each group. Significant improvement, as determined by adherence to practice protocols and reduction in practice variation, was observed for cardiac index < 1.6 L/min/m2 (min), mean arterial pressure < 40 mmHg (min), venous saturation < 60% (min), arterial blood temperature of > 37.50C (min), minimum pCO2 (mmHg), maximum pCO2 (mmHg), and minimum pO2 (mmHg). There was no change in the minimum haemoglobin (g/dl) on bypass. Automated generation of QI resulted in improved adherence to process of care guidelines, highlighting the potential of electronic data collection. This technique is optimised in a CQI programme, utilising statistical control charts for data interpretation.

Electronic data processing: the pathway to automated quality control of cardiopulmonary bypass

Electronic data collection during cardiac surgery creates an enormous data source that has many potential applications. After the introduction of the Stockert Data Management System (DMS; Munich, Germany) to our perfusion practice, we recognized that the data could be used for the purpose of quality control (QC). Our aim was to create an automated technique of data analysis and feedback for cardiopulmonary bypass (CPB) procedures. Using visual basic programming, we created a process by which data from the DMS is analyzed and processed in a Microsoft Access database after a CPB procedure. The processing is designed to transfer the collected data to a research database and create a number of CPB quality indicator (QI) parameters, such as mean arterial pressure being less than 40 mmHg for more than 5 minutes or a venous saturation of less than 60% for more than 5 minutes. In the event of QI parameter detection, a QC report is generated and e-mailed to the senior perfusionist and the perfusionist performing the procedure. The introduction of electronic data collection and subsequent development of electronic data processing techniques has enabled us to transfer the data into a readily accessible database and create a data set of perfusion variables and quality indicators for CPB procedures. This data set may be used for immediate automated QC feedback after CPB procedures and direction of performance improvement initiatives through retrospective or prospective data analysis as part of a continuous quality improvement process.

A syndromal analysis of neuropsychological outcome following coronary artery bypass graft surgery

BACKGROUND

Studies of neuropsychological outcome following coronary artery bypass graft surgery (CABG) have traditionally dichotomised patients as "impaired" or "unimpaired". This conceals the potential heterogeneity of deficits due to different mechanisms and sites of brain injury.

OBJECTIVES

To explore neuropsychological outcome following CABG and determine to what extent it conforms to prototypic cortical and/or subcortical neurobehavioral syndromes and whether different intraoperative physiologic measures are associated with different subtypes of neuropsychological outcome.

METHODS

Neuropsychological tests were administered to 85 patients before and after elective CABG and to 50 matched normal control subjects. Pre- to postoperative change scores were computed using standardised regression based norms. Change scores on selected memory measures were subjected to cluster analysis to identify qualitatively distinct subtypes of memory outcome. Emergent clusters were compared on non-memory measures, intraoperative physiologic measures, and demographic variables.

RESULTS

Three subtypes of memory outcome were identified: memory spared (48% of patients), retrieval deficit (35%), and encoding/storage deficit (17%). Contrary to expectation, the subgroups were indistinguishable on measures of confrontation naming and manual dexterity and on intraoperative cardiac surgical physiologic measures and demographic variables. The encoding/storage deficit subgroup exhibited executive dysfunction.

CONCLUSIONS

Heterogeneous profiles of neuropsychological dysfunction were found following CABG although they did not tightly conform to prototypic cortical and subcortical neurobehavioral syndromes. This challenges the value and appropriateness of the common practice of collapsing individual test scores to arrive at a single figure to define "impairment". Whether different subtypes of neuropsychological outcome are caused by different pathophysiologic mechanisms remains unknown.

The dental role in smoking cessation advice for patients with mental and behavioural disorders — time for improvement?

The past few years have seen an increasing emphasis upon the role of the dental team in smoking cessation. The recent advances in knowledge of the level and role of tobacco use in patients with mental and behavioural disorders, the biological factors involved and the influences of tobacco on psychiatric medication metabolism and side effects has not been reflected in dental postgraduate education. Perhaps it is time for an evidence based improvement in care standards by referring these patients for specialist cessation advice?

Lycopene from two food sources does not affect antioxidant or cholesterol status of middle-aged adults

Background

Epidemiological studies have reported associations between reduced cardiovascular disease and diets rich in tomato and/or lycopene. Intervention studies have shown that lycopene-containing foods may reduce cholesterol levels and lipid peroxidation, factors implicated in the initiation of cardiovascular disease. The objective of this study was to determine whether consumption of lycopene rich foods conferred cardiovascular protection to middle-aged adults as indicated by plasma lipid concentrations and measures of ex vivo antioxidants.

Methods

Ten healthy men and women consumed a low lycopene diet with no added lycopene (control treatment) or supplemented with watermelon or tomato juice each containing 20 mg lycopene. Subjects consumed each treatment for three weeks in a crossover design. Plasma, collected weekly was analyzed for total cholesterol, high density lipoprotein cholesterol (HDL-C) and triglyceride concentrations and for the antioxidant biomarkers of malondialdehyde formation products (MDA), plasma glutathione peroxidase (GPX) and ferric reducing ability of plasma (FRAP). Data were analyzed using Proc Mixed Procedure and associations between antioxidant and lipid measures were identified by Pearson's product moment correlation analysis.

Results

Compared to the control diet, the lycopene-containing foods did not affect plasma lipid concentrations or antioxidant biomarkers. Women had higher total cholesterol, HDL-C and triglyceride concentrations than did the men. Total cholesterol was positively correlated to MDA and FRAP while HDL-C was positively correlated to MDA and GPX. GPX was negatively correlated to triglyceride concentration.

Conclusions

The inclusion of watermelon or tomato juice containing 20 mg lycopene did not affect plasma lipid concentrations or antioxidant status of healthy subjects. However, plasma cholesterol levels impacted the results of MDA and FRAP antioxidant tests.

Removal of glucose from the cardiopulmonary bypass prime: a prospective clinical audit

To quantify our decision for the removal of glucose and the use of mannitol as a substitute osmotic agent in the cardiopulmonary bypass prime, we conducted a prospective clinical audit to evaluate the effects of this change on patient outcomes. Data were prospectively collected for 172 consecutive routine cardiac surgery patients. The first 85 patients (Surgeon A, 42 patients [Group 1], Surgeon B, 43 patients [Group 2]) received 1000 mL Plasmalyte 148 + 5% glucose as per institutional protocol. The remaining priming volume for each group consisted of 500 mL hemaccel or 4% albumin, 50 mL 8.4% sodium bicarbonate, 100 mL Hartmann's solution. The change to a glucose-free prime was then initiated, substituting Plasmalyte 148 (without 5% glucose) for the Plasmalyte 148 + 5% glucose, in addition 12.5 g mannitol was administered following delivery of cardioplegia to the patients operated on by Surgeon B. Surgeon A would not include mannitol at this time. Forty-one patients operated by Surgeon A (Group 3) subsequently received Plasmalyte 148, and 46 patients operated on by Surgeon B (Group 4) received Plasmalyte 148 plus mannitol. Analysis was performed stratified by surgeon to quantify the effects of removing glucose from the prime. Comparisons were made between groups 1 and 3, and 2 and 4. Net fluid changes were recorded from pre-CPB, up to 24-h postoperatively. Intraoperative data collection included serum glucose, hematocrit, osmolality, return to rhythm, arrhythmias, and blood transfusions. Post-operative variables, including cardiac enzymes, arrhythmias, intubation time, length of stay, and mortality were also collected. Removal of glucose from the CPB prime resulted in a lower serum glucose concentration (mmol/L) during CPB (Gp 1 [13.6] vs. Gp 3 [5.4]; Gp 2 [14.7] vs. Gp 4 [5.4], p < .05). The addition of 12.5 g of mannitol to the CPB prime resulted in a significantly lower net fluid gain (mL) 24 h postoperatively (Gp 2[2792] vs. Gp 4 [1970], p < .05) and greater CPB hematocrit (%) (Gp 2 [24.3] vs. Gp 4 [26], p < .05). No other results were found to be significant (except CPB plasma osmolality (Groups 2 and 4) and sodium concentration [Groups 1 and 3]). The results of our audit provide an evidence base to support our change in practice to utilize nonglucose primes.

Coronary artery baroreceptor-mediated changes in arterial pressure: a pilot study in conscious and anaesthetized sheep

1. Evidence suggesting the presence of coronary artery baroreceptors on coronary arteries has existed for over 30 years. 2. Evidence that activation of ventricular mechanoreceptors can elicit cardiovascular changes has been challenged, with those changes now thought to be due to coronary artery mechanoreceptors. 3. Studies have suggested that coronary artery mechanoreceptors act as coronary baroreceptors with a role in cardiovascular regulation. However, all evidence to date has been obtained in anaesthetized animal models in physiologically compromised intra-operative states. 4. The purpose of the present study was to design an ovine model that would allow the discrete stretch of coronary arteries without causing ischaemia or changing flow or intra-arterial pressure and that would confirm results seen in previous studies. In addition, the possibility that the technique could be used for studies of coronary artery baroreflexes in conscious sheep was investigated. 5. Controlled stretch of the proximal left anterior descending coronary artery elicited decreases in arterial pressure without changes in heart rate or electrocardiographic activity in halothane-anaesthetized sheep. Similar results were demonstrated in conscious sheep after surgical recovery of up to 2 weeks. 6. The present study supports the possibility that coronary artery baroreceptors exist and likely have a role in cardiovascular regulation. The results of the present study in anaesthetized sheep are in agreement with previous results in anaesthetized animals, but also provide the first demonstration of coronary baroreceptor activity in a conscious animal model, underscoring the potential use of the model in the study of coronary artery baroreceptors in the intact animal.

Purification and characterization of a beta-glucosidase from Citrus sinensis var. Valencia fruit tissue

A preliminary survey demonstrated activity for alpha-D-glucosidase, alpha-D-mannosidase, alpha-L-arabinosidase, beta-D-glucosidase, beta-D-xylosidase, and beta-D-galactosidase in orange fruit flavedo and albedo tissue. alpha-L-Rhamnosidase was not detected. Subsequently, a beta-glucosidase was purified from mature fruit rag tissue (composed of intersegmental septa, squeezed juice sacs, and fruit core tissue) of Citrus sinensis var. Valencia. The beta-glucosidase exhibited low levels of activity against p-nitrophenyl-beta-D-fucopyranoside (13.5%) and p-nitrophenyl-alpha-D-glucopyranoside (7.0%), compared to its activity against p-nitrophenyl-beta-D-glucopyranoside (pNPG, 100%). The enzyme was purified by a combination of ion exchange (anion and cation) and gel filtration (Superdex and Toyopearl HW-55S) chromatography. It has an apparent molecular mass of 64 kDa by denaturing electrophoresis or 55 kDa by gel filtration chromatography (BioGel P-100). Hydrolysis of pNPG demonstrated a pH optimum between 4.5 and 5.5. At pH 5.0 the temperature optimum was 40 degrees C. At pH 5.0 and 40 degrees C the K(m) for pNPG was 0.1146 mM and it had a V(max) of 5.2792 nkatal x mg(-1) protein (katal = 0.06 International Units = the amount of enzyme that produces, under standard conditions, one micromol of product per min). Of the substrates tested, the enzyme was most active against the disaccharide cellobiose (1-->4), but was not active against p-nitrophenyl-beta-D-cellobioside. High levels of activity also were observed with the disaccharides laminaribiose (1-->3), gentiobiose (1-->6), and sophorose (1-->2). Activity greater than that observed with pNPG was obtained with the flavonoids hesperetin-7-glucoside and prunin (naringenin-7-glucoside), salicin, mandelonitrile-beta-D-glucoside (a cyanogenic substrate), and sinigrin (a glucosinolate). The enzyme was not active against amygdalin, coniferin, or limonin glucoside.

Burn wound itch control using H1 and H2 antagonists

This study investigated the use of a combination of H1 and H2 antagonists and topical medications to control burn wound itch. Graeco-Latin square assignment provided an oral combination of 1) cetirizine and cimetidine or 2) diphenhydramine and placebo in four divided doses. The study protocol lasted 16 days divided into 4-day intervals, scoring itch before the initial dose of medication and at 1-hour, 6-hour, and 12-hour intervals after the first medication. A significant difference between mean itch scores across the four times was observed (Wilks' Lambda F = 26.52, df = 3, P <.0005). A three-way nested repeated measures interaction effect (Wilks' Lambda F = 9.85, df = 9, P <.0005) was observed representing a significantly different pattern on days 1 to 4 of the study compared with the remaining days. Controlling for the effect of topical medications, the cetirizine/cimetidine combination demonstrated a dramatic improvement at 1 and 6 hours, and a moderate improvement at 12 hours after initial medication for the day when compared with the diphenhydramine/placebo combination.

The Octopus II stabilizing system: biochemical and neuropsychological outcomes in coronary artery bypass surgery

INTRODUCTION

The aim of this study was to determine if coronary artery bypass graft (CABG) surgery performed utilizing the Octopus II stabilizing system provides myocardial and cerebral protection comparable to traditional CABG surgery utilizing cardiopulmonary bypass (CPB).

METHODS

Elective patients requiring surgery for double or triple vessel disease were randomized to receive either conventional CABG with CPB (n = 14) or OPCAB using the Octopus II stabilizing system (n = 12), after receiving institutional approval and written consent. Exclusion criteria included previous cardiac surgery, recent myocardial infarction, and previous cerebrovascular disease. Troponin T (TnT) was measured preoperatively and at 2, 4, 6, 8, 10, 12, 24, and 72 hours after initiation of grafting. Neuropsychological assessments (10 measures) were performed in the week prior to surgery, one week, and six months after surgery.

RESULTS

Troponin T release was reduced in the OPCAB patients at all time points (repeated measures ANOVA p = 0.043), reaching significance at 8, 10 and 12 hours (p = 0.033, 0.038, 0.019). Other factors (composite clinical end point (prolonged LOS or ICU stay or 30-day mortality), infarction, and intubation time) did not show any significant differences between the two groups. The incidence of neuropsychological deficits was not different between the two groups at both seven-day and six-month follow-up assessments.

CONCLUSIONS

Decreased TnT release suggests a myocardial benefit for the OPCAB procedure. A neuropsychological benefit remains to be demonstrated.

Evaluation of neurologic assessment and outcomes in cardiac surgical patients

It is well recognized that cardiac surgery with cardiopulmonary bypass can potentially induce a wide spectrum of central nervous system (CNS) sequelae. Our awareness of the prevalence of these CNS complications is dependent on the validity of the available diagnostic methods. Current assessment methods designed to detect both focal and diffuse cerebral ischemia include neurologic examination, imaging techniques, biochemical markers, neuropsychologic assessment, and patient perceived outcomes. These techniques vary in their sensitivity and specificity, as well as feasibility for use in everyday clinical practice. There are currently only limited standardized methodologic guidelines for the assessment of CNS complications after cardiac surgery, which has resulted in considerable interstudy variability in the identification and reporting of outcomes. The application of clearly definable endpoints for reporting of CNS outcomes would be beneficial. The wealth of available data suggests that the incidence of overt CNS injury such as stroke has declined since the 1980s and is now approximately 2%, whereas evidence suggests that up to one third of cardiac surgery patients experience postoperative cognitive deficits. One of the clear strengths of the current era is the recognition of CNS injury associated with cardiac surgery, and the quest to improve our understanding of these outcomes. The application of more uniform assessment and reporting practices is surely vital to the continued advancement of cardiac surgery.

Preoperative depression and mortality in coronary artery bypass surgery: preliminary findings

BACKGROUND

There is convincing evidence to suggest that depression significantly increases the risk of mortality following myocardial infarction. There are few data concerning depression as a risk factor for mortality following cardiac surgery. The aim of the present observational study was to determine if preoperative depressive symptoms resulted in an increased risk of late mortality following cardiac surgery.

METHODS

Preoperative assessments of depressive symptoms were performed on 158 patients undergoing coronary artery bypass surgery. Elevated preoperative depression symptoms were defined as a depression anxiety stress scale score of > or = 10.

RESULTS

Twenty-four of the 158 patients ( 15.2%) were classified as having elevated preoperative depressive symptoms. Patients were followed for a median of 25 months (range: 4-38 months). Three of the 24 patients (12.5%) with preoperative depressive symptoms died within the follow-up period, compared with three of the 134 (2.2%) non-depressed patients (odds ratio: 6.24; 95% CI: 1.18-32.98; P = 0.046). There were no other group differences on variables including population demographics, medical risk factors, surgical parameters, and indices of postoperative morbidity.

CONCLUSIONS

Elevated depressive symptoms before coronary bypass surgery may be a significant predictor of late death. Prospective studies evaluating the prevalence of depressive symptoms in cardiac surgical patients and their effect on long-term outcome must be undertaken.

A comparison of neuropsychologic deficits after extracardiac and intracaradiac surgery

OBJECTIVE

To compare the incidence of neuropsychologic deficits 1 week and 6 months after coronary artery bypass graft (CABG) surgery (extracardiac) and valve surgery with or without CABG surgery (intracardiac) using reliable change indices to define the incidence of neuropsychologic deficits.

DESIGN

Prospective study.

SETTING

Cardiac surgical unit in a university teaching hospital.

PARTICIPANTS

Patients scheduled for elective multiple-graft (> or =3 grafts) CABG surgery (n = 59), or elective valve surgery (with or without concomitant CABG surgery) (n = 50) and a matched sample of nonsurgical controls (n = 53).

INTERVENTIONS

Neuropsychologic assessments were performed 1 day before surgery, 7 days and 6 months after surgery.

MEASUREMENTS AND MAIN RESULTS

The 7-day assessment showed no significant differences between valve surgery patients and CABG surgery patients in the incidence of neuropsychologic deficits. When reassessed 6 months postoperatively, the valve group displayed a significantly higher incidence of deficits on the digit symbol test compared with the CABG group (valve 26.7% v CABG 6.8%). In the CABG group, there was a significant change in the incidence of deficits per patient from 7 days to 6 months (p = 0.03) that was not evident in the valve group.

CONCLUSION

There are some differences in the neuropsychologic outcome of extracardiac and intracardiac surgery. Patients undergoing isolated CABG surgery showed a greater reduction in the incidence of persisting deficits at 6 months than patients undergoing valve surgery with or without CABG surgery. This finding warrants further investigation, with particular attention to patients undergoing combined valve and coronary artery procedures.

Child health education for the foreign-born parent

Providing child health education for the foreign-born parent presents unique concerns related to language and culture. An innovative approach in a transcultural format used a presentation of basic child health information in English, with translators as facilitators. Foreign-born parents who need partial or complete language interpretation have ready access to translation support. The parents offer questions, comments, suggestions and evaluate the presentation through the translator. Each presentation can accommodate more than one language, since participants are grouped with the appropriate translator. The presentation is done in English and paced to allow for translation to be completed as material is offered. This type of presentation allows discussion of child health in a forum apart from the pediatric care setting. Because the presentation is the only focus, parents do not have the additional concern of immediate care of the child added to communication issues. Vocabulary relative to health care is developed from English into the parents' primary language, with the support of the translator. The pediatric nurse presenter has an opportunity to review health care practices that parents prefer, as well as interpret safety and efficacy.

The effect of denture adhesive on mandibular movement during chewing

BACKGROUND

The authors conducted a study to determine if reducing mandibular denture movement through the use of a denture adhesive improves chewing function in edentulous patients.

METHODS

The authors compared the mean chewing rates of 10 denture wearers who used and did not use a denture adhesive with that of a control group of 10 dentate people. The authors recorded mandibular movements using a multichannel magnetometer tracking system while the subjects chewed standardized pieces of dried apricots and fresh white bread. They made recordings for the test subjects without the use of denture adhesive and at zero, two and four hours after Fixodent denture adhesive cream (Procter & Gamble Co.) was applied to the mandibular denture.

RESULTS

The mean chewing rate for the control group was significantly faster than that of the test group at baseline (P < .01). The authors found statistically significant increases in the mean chewing rates for the test group after the denture adhesive was applied at all time points for both foods. None of the after--adhesive-application rates were significantly different from the control group's rate (P > .05).

CONCLUSIONS

Use of denture adhesive increased the mean chewing rate in test subjects immediately after and at two and four hours after denture adhesive was applied to a rate that approximated that observed in control subjects (P > .05).

CLINICAL IMPLICATIONS

These findings show that using a denture adhesive promotes a faster and more natural rate of chewing.

Coordinated control of XerC and XerD catalytic activities during Holliday junction resolution

Site-specific recombinases XerC and XerD function in the segregation of circular bacterial replicons. In a recombining nucleoprotein complex containing two molecules each of XerC and XerD, coordinated reciprocal switches in recombinase activity ensure that only XerC or XerD is active at any one time. Mutated recombinases that carry sub?stitutions of a catalytic arginine residue stimulate cleavage and strand exchange mediated by the partner recombinase on DNA substrates that are normally recombined poorly by the partner. This is associated with a reciprocal impairment of the recombinase's own ability to initiate catalysis. The extent of this switch in catalysis is modulated by changes in recombination site sequence and is not a direct consequence of any catalytic defect. We propose that altered interactions between the mutated proteins and their wild-type partners lead to an increased level of an alternative Holliday junction intermediate that has a conformation appropriate for resolution by the partner recombinase. The results indicate how subtle changes in protein-DNA architecture at a Holliday junction can redirect recombination outcome.

Mood state as a predictor of neuropsychological deficits following cardiac surgery

OBJECTIVES

mood disorders and neuropsychological deficits are both commonly reported occurrences after cardiac surgery. We examined the relationship between mood state and postoperative cognitive deficits in this population.

METHODS

assessments of neuropsychological functions and mood state (depression, anxiety, stress scales; DASS) were performed preoperatively and postoperatively on 147 patients undergoing cardiac surgery.

RESULTS

the incidence of preoperative depression, anxiety, and stress symptomatology was 16%, 27%, and 16%, respectively. The incidence of postoperative anxiety symptomatology significantly increased to 45% (p<0.001), while the incidence of depression and stress symptomatology remained stable (19% and 15%, respectively; ns). Changes in mood state did not influence changes in neuropsychological performance. Preoperative mood was a strong predictor of postoperative mood, and was related to postoperative deficits on measures of attention and memory.

CONCLUSIONS

an assessment of preoperative mood is critical in identifying patients at risk of postoperative mood disorders and neuropsychological deficits. Measures assessing somatic manifestations of anxiety may not be suitable for a surgical population.

Differential regulation of neuropeptide Y mRNA expression in the arcuate nucleus and locus coeruleus by stress and antidepressants

In rats, circulating corticosterone and insulin are involved in regulation of the hypothalamic neuropeptide Y (NPY) system, which in turn, is involved in regulation of the hypothalamic-pituitary-adrenal (HPA) axis. Since the HPA axis and stress responsivity is altered in diseases such as depression, we investigated interactions between the effects of stress and antidepressant drug treatment on arcuate nucleus and locus coeruleus NPY mRNA expressions using in-situ hybridization histochemistry. After acute (2 h) and repeated immobilization (2 h daily, for 14 days), plasma concentrations of corticosterone increased, and those of insulin decreased. The expression of NPY mRNA was significantly increased in the arcuate nucleus, but was unchanged in the locus coeruleus following acute and repeated immobilization. Adrenalectomized rats with systemic corticosterone replacement (ADX+CORT), whose corticosterone concentration was maintained at approximately 50-100 ng/ml during repeated stress, showed a decrease in plasma insulin and an increase in arcuate nucleus NPY mRNA similar to that observed in sham rats, suggesting that changes in NPY mRNA levels are more closely tied to circulating insulin than to circulating corticosterone. In contrast, locus coeruleus NPY mRNA expressions in ADX+CORT rats were significantly higher than those in sham rats after repeated stress. Desmethylimipramine (DMI) treatment for 24 days did not affect basal plasma concentrations of corticosterone or insulin, or arcuate nucleus NPY mRNA expressions, but significantly decreased basal levels of locus coeruleus NPY mRNA compared to saline-treated rats. After repeated immobilization (2 h daily, for 4 days), DMI significantly reduced the stress-induced rise in locus coeruleus NPY mRNA levels, but potentiated the stress-induced rise in arcuate nucleus NPY mRNA expression. These results demonstrate that: (1) the increase in arcuate nucleus NPY mRNA expressions in stressed rats closely follows the decrease in plasma concentrations of insulin; (2) increases in NPY mRNA expressions occur in the absence of changes in plasma corticosterone; and (3) desipramine treatment potentiated the effect of stress on arcuate nucleus NPY mRNA expressions, but blocked the repeated stress-induced increase in locus coeruleus NPY mRNA expressions. Thus, NPY mRNA expression in the arcuate nucleus and the locus coeruleus is sensitive to the effects of stress and to the antidepressant drug desipramine, but the arcuate nucleus NPY system is regulated by different mechanisms than the locus coeruleus NPY system. The results provide further evidence for the importance of circulating insulin in the regulation of the arcuate nucleus NPY system.

Protein dynamics, activity and cellular localization of soybean lipoxygenases indicate distinct functional roles for individual isoforms

Vegetative lipoxygenases (VLXs) in soybean are hypothesized to function in nitrogen storage and partitioning. Isoform-specific antibodies for four of the five known VLX isoenzymes were used to investigate the influence of source-sink status on protein levels, as well as to analyze the tissue and subcellular localization of the different isoforms. VLXD responded most strongly to sink limitation, although the levels of VLXA, B and C increased as well. After sink limitation, VLXD and the vegetative storage protein, VSPalpha, accumulated in the vacuoles of bundle sheath and paraveinal mesophyll cells, while VLXA, B and C localized to the cytosol of these cells. All five known VLX isoenzymes were active with both linoleic and linolenic acid substrates after expression in Escherichia coli. The strong upregulation of VLXD levels after sink limitation as well as the localization of this isoform to the vacuoles of paraveinal mesophyll and bundle sheath cells (where VSPs are found) strongly suggest that VLXD should be considered as a major storage protein in soybean leaves. Furthermore, since VLXA, B and C also accumulate in sink-limited soybean leaves, are located in the cytosol of paraveinal mesophyll cells and are active at pH values typically found in this compartment, their activities may well contribute to lipid metabolism in this tissue. This multi-gene family is thus ideally poised to play a pivotal role in the balance of N deposition relative to lipid-based storage, defense or signaling, by modulating contributions to these processes in the transient storage cells of the paraveinal mesophyll.

Specific chromosome alterations in fluconazole-resistant mutants of Candida albicans

The exposure of Candida albicans to fluconazole resulted in the nondisjunction of two specific chromosomes in 17 drug-resistant mutants, each obtained by an independent mutational event. The chromosomal changes occurred at high frequencies and were related to the duration of the drug exposure. The loss of one homologue of chromosome 4 occurred after incubation on a fluconazole medium for 7 days. A second change, the gain of one copy of chromosome 3, was observed after exposure for 35 or 40 days. We found that the mRNA levels of ERG11, CDR1, CDR2, and MDR1, the candidate fluconazole resistance genes, remained either the same or were diminished. The lack of overexpression of putative drug pumps or the drug target indicated that some other mechanism(s) may be operating. The fluconazole resistance phenotype, electrophoretic karyotypes, and transcript levels of mutants were stable after growth for 112 generations in the absence of fluconazole. This is the first report to demonstrate that resistance to fluconazole can be dependent on chromosomal nondisjunction. Furthermore, we suggest that a low-level resistance to fluconazole arising during the early stages of clinical treatment may occur by this mechanism. These results support our earlier hypothesis that changes in C. albicans chromosome number is a common means to control a resource of potentially beneficial genes that are related to important cellular functions.

Effect of juice extractor settings on juice cloud stability

Juice was extracted from Valencia oranges using three different extractor settings. Differential juice cloud stability was observed. Soft-extracted juice was the most stable, and hard-extracted juice was the least stable. The medium-extracted juice had intermediate cloud stability. Yearly (1997 versus 1998) differences were observed, but the relationship among the juices did not change. Addition of protein extracts, obtained from each juice, to pasteurized juice also resulted in differential cloud stability. Using pectinmethylesterase (PME) activity estimated at pH 4.5, the effects of the protein extract mirrored results from raw juice. Estimating PME activity at pH 7.5 produced contradictory results, indicating that predicting consequences of PME activity estimated at pH 7.5 is unreliable.

Neuropsychological dysfunction after minimally invasive direct coronary artery bypass grafting

BACKGROUND

We compared postoperative neuropsychological dysfunction after minimally invasive direct coronary artery bypass grafting (MIDCAB) operation with coronary artery bypass graft operations using cardiopulmonary bypass.

METHODS

Neuropsychological assessment was performed preoperatively and before discharge on 7 patients undergoing MIDCAB procedures, 9 patients undergoing single-graft cardiopulmonary bypass operation, and 27 patients undergoing multiple-graft cardiopulmonary bypass operation. From a matched control group of 40 normal subjects reliable change indices were derived for each measure and used to determine the incidence of postoperative decline.

RESULTS

There was little difference between the MIDCAB and single-graft cardiopulmonary bypass groups on the incidence of neuropsychologic decline. However, the multiple-graft cardiopulmonary bypass group had a significantly higher incidence of decline than the MIDCAB and single-graft cardiopulmonary bypass groups on specific neuropsychologic measures, coupled with a significantly greater number of postoperative deteriorations per patient.

CONCLUSIONS

The elimination of cardiopulmonary bypass does not prevent neuropsychological dysfunction after cardiac operation as patients undergoing MIDCAB and single-graft cardiopulmonary bypass experience similar deteriorations in performance. However, the deterioration is markedly worsened when the number of surgical grafts is increased.

Temporal and spatial patterns of c-fos mRNA induced by intravenous interleukin-1: a cascade of non-neuronal cellular activation at the blood-brain barrier

Brain cells responsive to a peripheral immune challenge, identified by in situ hybridization of c-fos mRNA following intravenous administration of the proinflammatory cytokine interleukin-1beta (IL-1) or sterile saline, were investigated at 0.5, 1, and 3 hours postinjection in rats. Doses of IL-1 ranged from 0.05 to 10 microg/kg; induction of c-fos mRNA occurred at > or = 0.5 pg/kg. The majority of IL-1-induced c-fos mRNA-positive cells were non-neuronal cells located in barrier regions of the brain. The cells became radiolabeled in two separate but related spatiotemporal patterns. The first pattern, occurring at 0.5 hour, was characterized by c-fos mRNA labeling of cells of the outer meninges (mainly arachnoid), blood vessels (arteries, veins, and capillaries), and choroid plexus. This activation pattern disappeared at 1 hour. At 3 hours, a second activation pattern appeared in cells located just inside the now quiescent barrier cells. In addition, the circumventricular organs each showed characteristic spatiotemporal labeling patterns resulting from successive activation of specific cell types, with a general spread of activation directed away from the circumventricular organs over time. At 3 hours post IL-1, c-fos and glial fibrillary acidic protein (GFAP) mRNAs showed colocalization in the arcuate nucleus/median eminence/glia limitans region. We propose that the first wave of activation is elicited by blood-borne immune signals, but the second wave is caused by molecules generated within the first set of activated cells. The transduced signal appears to propagate to neighboring receptive cells by extracellular diffusion. In this manner, blood-brain barrier cells can transduce peripheral IL-1 signals in widespread areas of the brain, although the circumventricular organs may be the most effective loci for signal transduction.

Somatostatin stimulates the brush-tailed possum sphincter of Oddi in vitro and in vivo

BACKGROUND & AIMS

Somatostatin, a neuropeptide and hormone, is found in the biliary tract of several species. The aim of this study was to map the distribution of somatostatin-like immunoreactive nerve fibers in the extrahepatic biliary tract of the Australian possum and to determine the pharmacological effects of somatostatin 1-14 on sphincter of Oddi activity in vitro and in vivo.

METHODS

Tissue was harvested for immunohistochemistry and sphincter of Oddi for circular or longitudinal muscle contractility. In anesthetized possums, sphincter of Oddi motility was measured by manometry, and transsphincteric flow was measured gravimetrically.

RESULTS

Somatostatin immunoreactivity was evident in gallbladder ganglia nerve cell bodies and in nerve fibers of the common bile duct and sphincter of Oddi. Somatostatin 1-14 increased circular and longitudinal muscle contraction amplitude 3-4-fold (P < 0.05), but only the longitudinal muscle contraction amplitude was tetrodotoxin sensitive. Somatostatin 1-14 stimulated spontaneous sphincter of Oddi motility in a tetrodotoxin-insensitive manner, increasing basal pressure, contraction frequency, and amplitude 2-4-fold (P < 0.05) and reducing transsphincteric flow to 25% of control (P < 0.0001).

CONCLUSIONS

Somatostatin-like immunoreactivity is present in the extrahepatic biliary tree, and somatostatin 1-14 stimulates sphincter of Oddi smooth muscle and nerves. The major action is direct stimulation of sphincter of Oddi circular muscle, which reduces transsphincteric flow.

Retention, antimicrobial activity, and clinical outcomes following use of a bioerodible tetracycline gel in moderate-to-deep periodontal pockets

This randomized, examiner masked, split mouth study evaluated a new model to test periodontal therapy involving a novel bioerodible copolymer gel containing tetracycline hydrochloride. Responses to the tetracycline gel and untreated control were compared for product tolerance and 3 different measures of effectiveness (drug retention, changes in microbial levels, and clinical status). The test gel was administered by syringe into the periodontal pockets of 18 systemically healthy adult volunteers, each of whom presented with 3 or more sites with 6 mm probing depths. Gingival crevicular fluid samples were used to monitor daily drug levels over 7 days, while clinical responses were assessed at day 30. Overall, the test gel was well-tolerated by all patients. For the 3 effectiveness measures, tetracycline was released throughout the observation period and mean levels exceeded 100 microg/mL over 6 days, statistically significant reductions in selected periodontal pathogens were evident at day 7 but not at day 30, and mean probing depth reductions at test sites were 1.12 mm at 30 days versus 0.36 mm at untreated control sites (P=0.012). The safety profile, longer-term drug retention, antimicrobial activity, and clinical response in this Phase I study suggest that this tetracycline-containing copolymer gel platform may represent a safe and effective bioerodible therapy for periodontitis. The experimental model also shows merit for early phase clinical testing of novel therapeutic agents.

Neuropsychologic changes after coronary artery bypass grafting: use of reliable change indices

BACKGROUND

A method of defining change in neuropsychologic test scores that accounts for test reliability and practice effects was applied to determine accurately the incidence of acquired neuropsychologic deficits after coronary artery bypass grafting.

METHODS

Neuropsychologic assessment was performed on 50 patients before and at 7 days after either hypothermic or normothermic coronary artery bypass grafting. From a matched control group of 24 normal subjects who were examined twice over a similar interval, reliable change indices that controlled for measurement error and practice effects were calculated for each neuropsychologic measure. With the use of these indices, the incidence of postoperative decline among the study patients was determined. For comparison, the incidence of decline using the "one standard deviation" criterion also was calculated.

RESULTS

Comparing the reliable change and standard deviation methods, statistically significant differences in the incidence of decline were observed in 5 of 11 neuropsychologic measures. The reliable change method identified more patients with neuropsychologic deficits on most measures.

CONCLUSIONS

The control of measurement error and practice effects can alter significantly the calculated incidence of neuropsychologic impairment after coronary artery bypass grafting.

Substance P stimulates sphincter of Oddi motility and inhibits trans-sphincteric flow in the Australian brush-tailed possum

Substance P containing nerves are widely distributed throughout the gastrointestinal tract. The aims of this study were to determine the distribution of substance P containing nerves in the extrahepatic biliary tree of the Australian brush-tailed possum and to characterize the effect of exogenous substance P on the sphincter of Oddi (SO) motility and transphincteric flow in vivo. Immunohistochemical staining of fixed specimens (n = 8) found moderate numbers of substance P containing nerve cell bodies and fibres throughout the neural plexuses of the SO, in particular in the serosal and intraluminal nerve trunks of the SO and gallbladder. Synthetic porcine substance P (1-2000 ng kg-1), administered by close intra-arterial injection (i.a.; n = 7), produced a dose-dependent elevation in basal pressure [P < 0.01] and an associated dose-dependent reduction in trans-sphincteric flow [P < 0.0001]. Substance P had no significant dose-dependent effect on SO phasic contraction amplitude or frequency. Tetrodotoxin (9 micrograms kg-1, i.a.) did not inhibit the effect of substance P on SO motility and trans-sphincteric flow (n = 5). In conclusion, substance P containing nerves are found throughout the possum extrahepatic biliary tree. Exogenous substance P stimulates SO motility and reduces trans-sphincteric flow in vivo by acting directly on the sphincter smooth muscle.

The buccal space: a doorway for percutaneous CT-guided biopsy of the parapharyngeal region

We performed percutaneous CT-guided needle biopsies with a transfacial approach in the diagnosis of lesions of the parapharyngeal region. Via the buccal space, core needle biopsy specimens were obtained in eight patients with known parapharyngeal abnormalities identified by CT and/or MR imaging. In all cases, sufficient tissue was obtained to provide a definitive histologic diagnosis. There were no significant complications. This approach provides a reliable method for evaluation of parapharyngeal lesions.

Perioperative use of 0.12% chlorhexidine gluconate for the prevention of alveolar osteitis: efficacy and risk factor analysis

OBJECTIVES

The purposes of this study were to evaluate the use of 0.12% chlorhexidine gluconate as a prophylactic therapy for the prevention of alveolar osteitis and to further examine subject-based risk factors associated with alveolar osteitis.

STUDY DESIGN

The trial was a randomized, double-blind, placebo-controlled, parallel-group study conducted among 279 subjects, each of whom required oral surgery for the removal of a minimum of one impacted mandibular third molar. Subjects were instructed to rinse twice daily with 15 ml of chlorhexidine or placebo mouthrinse for 30 seconds for 1 week before and 1 week after the surgical extractions. This regimen included a supervised presurgical rinse. Alveolar osteitis diagnosis was based on the subjective finding of increasing postoperative pain at the surgical site that was not relieved with mild analgesics, supported by clinical evidence of one or more of the following: loss of blood clot, necrosis of blood clot, and exposed alveolar bone.

RESULTS

In comparison with use of the placebo mouthrinse, prophylactic use of the chlorhexidine mouthrinse resulted in statistically significant (p < 0.05) reductions in the incidence of alveolar osteitis. With chlorhexidine therapy, the subject- and extraction-based incidences of alveolar osteitis in the evaluable subset (271 subjects) were reduced, relative to placebo, by 38% and 44%, respectively. The corresponding odds ratios that describe the increased odds of experiencing alveolar osteitis in the placebo group were 1.87 and 2.05 for subject- and extraction-based analyses, respectively. In comparison with nonuse of oral contraceptives, the use of oral contraceptives in female subjects was related to a statistically significant increase in the incidence of alveolar osteitis (odds ratio = 1.92, p = 0.035). Relative to male subjects, the observed incidence of alveolar osteitis for female subjects not using oral contraceptives was not statistically significant (odds ratio = 1.18, p = 0.64). Smoking did not increase the incidence of alveolar osteitis relative to not smoking (odds ratio = 1.20, p = 0.33).

CONCLUSIONS

These data confirm that the prophylactic use of 0.12% chlorhexidine gluconate mouthrinse results in a significant reduction in the incidence of alveolar osteitis after the extraction of impacted mandibular third molars. In addition, oral contraceptive use in females was confirmed to be a risk factor for the development of alveolar osteitis.

A survey of the microbial population and ethanol content of bagged salad

Five nationally and regionally distributed brands of ready-to-eat salads in sealed bags were sampled from major supermarket chains. At time of purchase, product temperature was 4 to 7 degrees C; the mean mesophilic microbial population was 1.0 x 10(7) CFU/g; the yeast population was 210 CFU/g; the mean headspace O2 and CO2 concentrations were 1.2 and 12%, respectively; and the ethanol content was 700 ppm. For samples analyzed on the expiration date (14 to 16 days after packaging) the mean mesophilic microbial population was 6 x 10(7) CFU/g; ethanol content was 1,500 ppm; and the headspace gas had not markedly changed from time of purchase.

The adhesion-associated sca operon in Streptococcus gordonii encodes an inducible high-affinity ABC transporter for Mn2+ uptake

ScaA lipoprotein in Streptococcus gordonii is a member of the LraI family of homologous polypeptides found among streptococci, pneumococci, and enterococci. It is the product of the third gene within the scaCBA operon encoding the components of an ATP-binding cassette (ABC) transporter system. Inactivation of scaC (ATP-binding protein) or scaA (substrate-binding protein) genes resulted in both impaired growth of cells and > 70% inhibition of 54Mn2+ uptake in media containing < 0.5 microM Mn2+. In wild-type and scaC mutant cells, production of ScaA was induced at low concentrations of extracellular Mn2+ (< 0.5 microM) and by the addition of > or = 20 microM Zn2+. Sca permease-mediated uptake of 54Mn2+ was inhibited by Zn2+ but not by Ca2+, Mg2+, Fe2+, or Cu2+. Reduced uptake of 54Mn2+ by sca mutants and by wild-type cells in the presence of Zn2+ was abrogated by the uncoupler carbonylcyanide m-chlorophenylhydrazone, suggesting that Mn2+ uptake under these conditions was proton motive force dependent. The frequency of DNA-mediated transformation was reduced > 20-fold in sca mutants. The addition of 0.1 mM Mn2+ to the transformation medium restored only partly the transformability of mutant cells, implying an alternate role for Sca proteins in the transformation process. Cells of sca mutants were unaffected in other binding properties tested and were unaffected in sensitivity to oxidants. The results show that Sca permease is a high-affinity mechanism for the acquisition of Mn2+ and is essential for growth of streptococci under Mn2+-limiting conditions.

Activated T helper 1 and T helper 2 cells differentially express the beta-2-adrenergic receptor: a mechanism for selective modulation of T helper 1 cell cytokine production

We recently reported that resting clones of murine Th1 cells, but not resting Th2 cells, expressed a detectable level of the beta-2-adrenergic receptor (beta 2AR). In the present study, we proposed that the level of beta 2AR expression on anti-CD3 mAb-activated CD4+ effector Th cells may differ from the level on resting cells, and that a change in receptor expression may alter the functional responsiveness of these cells to either the beta 2AR-selective ligand terbutaline or the sympathetic neurotransmitter norepinephrine. Following anti-CD3 activation, the beta 2AR was expressed on Th1 cells, but not Th2 cells. The number of binding sites on Th1 cells was maintained, with no change in affinity, over a 24-h activation period. When Th clones were exposed to terbutaline following anti-CD3 activation, Th1 cell, but not Th2 cell, cytokine production was modulated. IL-2 production by Th1 cells was decreased, while IFN-gamma production was not significantly altered. The decrease in IL-2 production was concentration dependent and was blocked by an antagonist. In comparison with control supernatants, the lower level of IL-2 present in terbutaline-exposed culture supernatants supported the proliferation of an IL-2-dependent Th1 clone to a lesser degree. Additionally, norepinephrine down-modulates IL-2, but not IFN-gamma, production by binding specifically to the beta-adrenergic receptor. Thus, a detectable level of the beta 2AR is expressed on activated Th1 cells, but not activated Th2 cells, thereby providing a mechanism by which IL-2 production is preferentially modulated by an endogenous and therapeutic ligand following Th1 cell activation.

Activated T helper 1 and T helper 2 cells differentially express the beta-2-adrenergic receptor: a mechanism for selective modulation of T helper 1 cell cytokine production

We recently reported that resting clones of murine Th1 cells, but not resting Th2 cells, expressed a detectable level of the beta-2-adrenergic receptor (beta 2AR). In the present study, we proposed that the level of beta 2AR expression on anti-CD3 mAb-activated CD4+ effector Th cells may differ from the level on resting cells, and that a change in receptor expression may alter the functional responsiveness of these cells to either the beta 2AR-selective ligand terbutaline or the sympathetic neurotransmitter norepinephrine. Following anti-CD3 activation, the beta 2AR was expressed on Th1 cells, but not Th2 cells. The number of binding sites on Th1 cells was maintained, with no change in affinity, over a 24-h activation period. When Th clones were exposed to terbutaline following anti-CD3 activation, Th1 cell, but not Th2 cell, cytokine production was modulated. IL-2 production by Th1 cells was decreased, while IFN-gamma production was not significantly altered. The decrease in IL-2 production was concentration dependent and was blocked by an antagonist. In comparison with control supernatants, the lower level of IL-2 present in terbutaline-exposed culture supernatants supported the proliferation of an IL-2-dependent Th1 clone to a lesser degree. Additionally, norepinephrine down-modulates IL-2, but not IFN-gamma, production by binding specifically to the beta-adrenergic receptor. Thus, a detectable level of the beta 2AR is expressed on activated Th1 cells, but not activated Th2 cells, thereby providing a mechanism by which IL-2 production is preferentially modulated by an endogenous and therapeutic ligand following Th1 cell activation.