WFUMB Guidelines/Guidance on Liver Multiparametric Ultrasound. Part 2: Guidance on Liver Fat Quantification

The World Federation for Ultrasound in Medicine and Biology (WFUMB) has promoted the development of this document on multiparametric ultrasound. Part 2 is a guidance on the use of the available tools for the quantification of liver fat content with ultrasound. These are attenuation coefficient, backscatter coefficient, and speed of sound. All of them use the raw data of the ultrasound beam to estimate liver fat content. This guidance has the aim of helping the reader in understanding how they work and interpret the results. Confounding factors are discussed and a standardized protocol for measurement acquisition is suggested to mitigate them. The recommendations were based on published studies and experts' opinion but were not formally graded because the body of evidence remained low at the time of drafting this document.

Pulmonary Arterial Pruning and Longitudinal Change in Percent Emphysema and Lung Function: The Genetic Epidemiology of COPD Study

BACKGROUND

Pulmonary endothelial damage has been shown to precede the development of emphysema in animals, and vascular changes in humans have been observed in COPD and emphysema.

RESEARCH QUESTION

Is intraparenchymal vascular pruning associated with longitudinal progression of emphysema on CT imaging or decline in lung function over 5 years?

STUDY DESIGN AND METHODS

The Genetic Epidemiology of COPD Study enrolled ever smokers with and without COPD from 2008 through 2011. The percentage of emphysema-like lung, or "percent emphysema," was assessed at baseline and after 5 years on noncontrast CT imaging as the percentage of lung voxels < -950 Hounsfield units. An automated CT imaging-based tool assessed and classified intrapulmonary arteries and veins. Spirometry measures are postbronchodilator. Pulmonary arterial pruning was defined as a lower ratio of small artery volume (< 5 mm2 cross-sectional area) to total lung artery volume. Mixed linear models included demographics, anthropomorphics, smoking, and COPD, with emphysema models also adjusting for CT imaging scanner and lung function models adjusting for clinical center and baseline percent emphysema.

RESULTS

At baseline, the 4,227 participants were 60 ± 9 years of age, 50% were women, 28% were Black, 47% were current smokers, and 41% had COPD. Median percent emphysema was 2.1 (interquartile range, 0.6-6.3) and progressed 0.24 percentage points/y (95% CI, 0.22-0.26 percentage points/y) over 5.6 years. Mean FEV1 to FVC ratio was 68.5 ± 14.2% and declined 0.26%/y (95% CI, -0.30 to -0.23%/y). Greater pulmonary arterial pruning was associated with more rapid progression of percent emphysema (0.11 percentage points/y per 1-SD increase in arterial pruning; 95% CI, 0.09-0.16 percentage points/y), including after adjusting for baseline percent emphysema and FEV1. Arterial pruning also was associated with a faster decline in FEV1 to FVC ratio (-0.04%/y per 1-SD increase in arterial pruning; 95% CI, -0.008 to -0.001%/y).

INTERPRETATION

Pulmonary arterial pruning was associated with faster progression of percent emphysema and more rapid decline in FEV1 to FVC ratio over 5 years in ever smokers, suggesting that pulmonary vascular differences may be relevant in disease progression.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00608764; URL: www.clinicaltrials.gov.

Future of breast elastography

Both strain elastography and shear wave elastography have been shown to have high sensitivity and specificity for characterizing breast lesions as benign or malignant. Training is important for both strain and shear wave elastography. The unique feature of benign lesions measuring smaller on elastography than B-mode imaging and malignant lesions appearing larger on elastography is an important feature for characterization of breast masses. There are several artifacts which can contain diagnostic information or alert to technique problems. Both strain and shear wave elastography continue to have improvements and new techniques will soon be available for clinical use that may provide additional diagnostic information. This paper reviews the present state of breast elastography and discusses future techniques that are not yet in clinical practice.

A controlled statistical study to assess measurement variability as a function of test object position and configuration for automated surveillance in a multicenter longitudinal COPD study (SPIROMICS)

PURPOSE

A test object (phantom) is an important tool to evaluate comparability and stability of CT scanners used in multicenter and longitudinal studies. However, there are many sources of error that can interfere with the test object-derived quantitative measurements. Here the authors investigated three major possible sources of operator error in the use of a test object employed to assess pulmonary density-related as well as airway-related metrics.

METHODS

Two kinds of experiments were carried out to assess measurement variability caused by imperfect scanning status. The first one consisted of three experiments. A COPDGene test object was scanned using a dual source multidetector computed tomographic scanner (Siemens Somatom Flash) with the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) inspiration protocol (120 kV, 110 mAs, pitch = 1, slice thickness = 0.75 mm, slice spacing = 0.5 mm) to evaluate the effects of tilt angle, water bottle offset, and air bubble size. After analysis of these results, a guideline was reached in order to achieve more reliable results for this test object. Next the authors applied the above findings to 2272 test object scans collected over 4 years as part of the SPIROMICS study. The authors compared changes of the data consistency before and after excluding the scans that failed to pass the guideline.

RESULTS

This study established the following limits for the test object: tilt index ≤0.3, water bottle offset limits of [-6.6 mm, 7.4 mm], and no air bubble within the water bottle, where tilt index is a measure incorporating two tilt angles around x- and y-axis. With 95% confidence, the density measurement variation for all five interested materials in the test object (acrylic, water, lung, inside air, and outside air) resulting from all three error sources can be limited to ±0.9 HU (summed in quadrature), when all the requirements are satisfied. The authors applied these criteria to 2272 SPIROMICS scans and demonstrated a significant reduction in measurement variation associated with the test object.

CONCLUSIONS

Three operator errors were identified which significantly affected the usability of the acquired scan images of the test object used for monitoring scanner stability in a multicenter study. The authors' results demonstrated that at the time of test object scan receipt at a radiology core laboratory, quality control procedures should include an assessment of tilt index, water bottle offset, and air bubble size within the water bottle. Application of this methodology to 2272 SPIROMICS scans indicated that their findings were not limited to the scanner make and model used for the initial test but was generalizable to both Siemens and GE scanners which comprise the scanner types used within the SPIROMICS study.

Insight into Best Variables for COPD Case Identification: A Random Forests Analysis

RATIONALE

This study is part of a larger, multi-method project to develop a questionnaire for identifying undiagnosed cases of chronic obstructive pulmonary disease (COPD) in primary care settings, with specific interest in the detection of patients with moderate to severe airway obstruction or risk of exacerbation.

OBJECTIVES

To examine 3 existing datasets for insight into key features of COPD that could be useful in the identification of undiagnosed COPD.

METHODS

Random forests analyses were applied to the following databases: COPD Foundation Peak Flow Study Cohort (N=5761), Burden of Obstructive Lung Disease (BOLD) Kentucky site (N=508), and COPDGene® (N=10,214). Four scenarios were examined to find the best, smallest sets of variables that distinguished cases and controls:(1) moderate to severe COPD (forced expiratory volume in 1 second [FEV1] <50% predicted) versus no COPD; (2) undiagnosed versus diagnosed COPD; (3) COPD with and without exacerbation history; and (4) clinically significant COPD (FEV1<60% predicted or history of acute exacerbation) versus all others.

RESULTS

From 4 to 8 variables were able to differentiate cases from controls, with sensitivity ≥73 (range: 73-90) and specificity >68 (range: 68-93). Across scenarios, the best models included age, smoking status or history, symptoms (cough, wheeze, phlegm), general or breathing-related activity limitation, episodes of acute bronchitis, and/or missed work days and non-work activities due to breathing or health.

CONCLUSIONS

Results provide insight into variables that should be considered during the development of candidate items for a new questionnaire to identify undiagnosed cases of clinically significant COPD.

Association between exposure to household cigarette smoking behavior and cigarette smoking in Hispanic adults: Findings from the Hispanic Community Health Study/Study of Latinos

BACKGROUND

Cigarette smoking behavior is highly determined by social influences during childhood and adolescence. This phenomenon has not been fully evaluated in the Hispanic/Latino population.

PURPOSE

To examine the association between exposure to household cigarette smoking behavior (HCSB) and adult cigarette smoking among a diverse Hispanic/Latino population living in four US urban centers. The effect of acculturation on cigarette smoking was also evaluated.

METHODS

Data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) (n=13,231, ages 18-74years, collected between March 2008 and June 2011) were analyzed using logistic regression.

RESULTS

HCSB exposure was an independent risk factor for adult current cigarette smoking in Hispanic/Latinos (OR 1.7; 95% CI 1.4, 2.1) after controlling for relevant confounders including socio-demographic and cultural factors. Cubans and Puerto Ricans had the highest prevalence of HCSB exposure (59% and 47% respectively) and highest prevalence of current cigarette smoking (26% and 32%) compared with other Hispanic/Latino groups, (p<.01).

CONCLUSIONS

Our data suggest that exposure to HCSB in Hispanics/Latinos living in the US is an independent predictor of adult cigarette smoking, and this association appears to be strongest in Cubans and Puerto Ricans.

Computed tomographic measures of airway morphology in smokers and never-smoking normals

Bronchial wall area percent (WA% = 100 × wall area/total bronchial cross sectional area) is a standard computed tomographic (CT) measure of central airway morphology utilized in smokers with chronic obstructive pulmonary disease (COPD). Although it provides significant clinical correlations, the range of reported WA% is narrow. This suggests limited macroscopic change in response to smoking or that remodeling proportionally affects the airway wall and lumen dimensions such that their ratio is preserved. The objective of this study is to assess central airway wall area (WA), lumen area (Ai), and total bronchial area (Ao) from CT scans of 5,179 smokers and 92 never smoking normal subjects. In smokers, WA, Ai, and Ao were positively correlated with forced expiratory volume in 1 s (FEV1) expressed as a percent of predicted (FEV1%), and the WA% was negatively correlated with FEV1% (P < 0.0001 for all comparisons). Importantly, smokers with lower FEV1% tended to have airways of smaller cross-sectional area with lower WA. The increases in the WA% across GOLD stages of chronic obstructive pulmonary disease (COPD) can therefore not be due to increases in WA. The data suggest two possible origins for the WA% increases: 1) central airway remodeling resulting in overall reductions in airway caliber in excess of the decreased WA or 2) those with COPD had smaller native airways before they began smoking. In both cases, these observations provide an explanation for the limited range of values of WA% across stages of COPD.

Identifying Patients with Undiagnosed COPD in Primary Care Settings: Insight from Screening Tools and Epidemiologic Studies

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality, yet research suggests this disease is greatly underdiagnosed. This literature review sought to summarize the most common and significant variables associated with case-finding or missed cases of COPD to inform more effective and efficient detection of high-risk COPD patients in primary care.

METHODS

PubMed and EMBASE were searched for articles describing case-finding and epidemiologic research to detect or characterize new cases of COPD. International studies in primary and non-primary care settings, published in English from 2002-2014, were eligible for inclusion. Studies related to risk factors for development of COPD were excluded.

RESULTS

Of the 33 studies identified and reviewed, 21 were case-finding or screening and 12 were epidemiological, including cross-sectional, longitudinal, and retrospective designs. A range of variables were identified within and across studies. Variables common to both screening and epidemiological studies included age, smoking status, and respiratory symptoms. Seven significant predictors from epidemiologic studies did not appear in screening tools. No studies targeted discovery of higher risk patients such as those with reduced lung function or risks for exacerbations.

CONCLUSION

Variables used to identify new cases of COPD or differentiate COPD cases and non-cases are wide- ranging, (from sociodemographic to self-reported health or health history variables), providing insight into important factors for case identification. Further research is underway to develop and test the best, smallest variable set that can be used as a screening tool to identify people with undiagnosed, high-risk COPD in primary care.

Adhesion molecules, endothelin-1 and lung function in seven population-based cohorts

CONTEXT

Endothelial function is abnormal in chronic obstructive pulmonary disease (COPD); whether endothelial dysfunction causes COPD is unknown.

OBJECTIVE

Test associations of endothelial biomarkers with FEV1 using instrumental variables.

METHODS

Among 26 907 participants with spirometry, ICAM-1, P-selectin, E-selectin and endothelin-1 were measured in subsets.

RESULTS

ICAM-1 and P-selectin were inversely associated with FEV1 among European-Americans (-29 mL and -34 mL per standard deviation of log-transformed biomarker, p < 0.001), as was endothelin-1 among African-Americans (-22 mL, p = 0.008). Genetically-estimated ICAM-1 and P-selectin were not significantly associated with FEV1. The instrumental variable for endothelin-1 was non-informative.

CONCLUSION

Although ICAM-1, P-selectin and endothelin-1 were inversely associated with FEV1, associations for ICAM-1 and P-selectin do not appear causal.

Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) in the liver--update 2012: a WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

Subclinical atherosclerosis, airflow obstruction and emphysema: the MESA Lung Study

Airflow obstruction is an independent risk factor for cardiovascular events in the general population. The affected vascular bed and contribution of emphysema to cardiovascular risk are unclear. We examined whether an obstructive pattern of spirometry and quantitatively defined emphysema were associated with subclinical atherosclerosis in the carotid, peripheral and coronary circulations. The Multi-Ethnic Study of Atherosclerosis recruited participants aged 45-84 yrs without clinical cardiovascular disease. Spirometry, carotid intima-media thickness (IMT), ankle-brachial index (ABI) and coronary artery calcium (CAC) were measured using standard protocols. Percentage of emphysema-like lung was measured in the lung windows of cardiac computed tomography scans among 3,642 participants. Multiple linear regression was used to adjust for cardiac risk factors, including C-reactive protein. Decrements in forced expiratory volume in 1 s (FEV(1)) and FEV(1)/forced vital capacity ratio were associated with greater internal carotid IMT, particularly among smokers (p=0.03 and p<0.001, respectively) whereas percentage emphysema was associated with reduced ABI regardless of smoking history (p=0.004). CAC was associated with neither lung function (prevalence ratio for the presence of CAC in severe airflow obstruction 0.99, 95% CI 0.91-1.07) nor percentage emphysema. An obstructive pattern of spirometry and emphysema were associated distinctly and independently with subclinical atherosclerosis in the carotid arteries and peripheral circulation, respectively, and were not independently related to CAC.

Randomised aspirin assignment and risk of adult-onset asthma in the Women's Health Study

BACKGROUND

Randomised data in men show a small but significant reduction in the risk of adult-onset asthma among those given aspirin. The results from an observational study in women suggest that frequent use of aspirin decreases the risk of adult-onset asthma, but randomised data in women are lacking. A study was undertaken to test the effect of 100 mg aspirin or placebo on alternate days on the risk of adult-onset asthma in the Women's Health Study.

METHODS

A randomised, double-blind, placebo-controlled clinical trial of aspirin and vitamin E was performed in apparently healthy women with no indication or contraindication to aspirin therapy and no history of asthma at study entry. Female health professionals self-reported an asthma diagnosis on yearly questionnaires.

RESULTS

Among 37 270 women with no reported history of asthma prior to randomisation and during 10 years of follow-up, there were 872 new cases diagnosed with asthma in the aspirin group and 963 in the placebo group (hazard ratio 0.90; 95% CI 0.82 to 0.99; p = 0.027). This apparent 10% lower relative risk of incident adult-onset asthma among those assigned to aspirin was significantly modified by body mass index, with no effect in women with a body mass index of >/=30 kg/m2. The effect of aspirin on adult-onset asthma was not significantly modified by age, smoking status, exercise levels, postmenopausal hormone use or randomised vitamin E assignment.

CONCLUSIONS

In this large randomised clinical trial of apparently healthy adult women, administration of 100 mg aspirin on alternate days reduced the relative risk of a newly reported diagnosis of asthma.

Plasma hemostatic factors and endothelial markers in four racial/ethnic groups: the MESA study

BACKGROUND

Hemostatic factors and endothelial markers may play some role in racial/ethnic differences in cardiovascular disease (CVD) rates. However, little information exists on hemostatic factors and endothelial markers across racial/ethnic groups.

OBJECTIVES

To describe, in four American racial/ethnic groups (Caucasian, Black, Hispanic, and Chinese), mean levels of selected hemostatic factors and endothelial markers.

PATIENTS AND METHODS

Multi-ethnic Study of Atherosclerosis baseline data were used (participant age: 45-84 years). Sex-specific analysis of covariance models, and t-tests for pairwise comparisons, were used to compare means of factors and markers. Adjustments were made for demographics and traditional CVD risk factors. Differences were significant at P < 0.05.

RESULTS

Blacks had the highest levels of factor VIII, D-Dimer, plasmin-antiplasmin (PAP), and von Willebrand factor, among the highest levels of fibrinogen and E-selectin (women only), but among the lowest levels of intercellular adhesion molecule 1 (ICAM-1), and, in men, the lowest levels of plasminogen activator inhibitor-1 (PAI-1). Whites and Hispanics tended to have intermediate levels of factors and markers, although they had the highest levels of ICAM-1, and Hispanics had the highest mean levels of fibrinogen and E-selectin (women only). Chinese participants had among the highest levels of PAI-1, but the lowest, or among the lowest, of all other factors and markers. No soluble thrombomodulin differences were observed.

CONCLUSIONS

In this large cohort, hemostatic factor and endothelial marker mean levels varied by race/ethnicity, even after adjustment for traditional CVD risk factors.

Recent exposure to particulate matter and C-reactive protein concentration in the multi-ethnic study of atherosclerosis

Ambient levels of particulate matter have been linked to cardiovascular disease. The mechanisms mediating these associations are poorly understood. One candidate mechanism is inflammation. Using data from the Multi-Ethnic Study of Atherosclerosis (2000-2002), the authors investigated the relation between exposure to particulate matter of less than or equal to 2.5 microm in diameter (PM2.5) and C-reactive protein concentration in 5,634 persons aged 45-84 years who were free of cardiovascular disease. Data from US Environmental Protection Agency monitors were used to estimate PM2.5 exposures for the prior day, prior 2 days, prior week, prior 30 days, and prior 60 days. Only the 30-day and 60-day mean exposures showed a weak positive association with C-reactive protein, and confidence intervals were wide: relative increases in C-reactive protein per 10 microg/m3 of PM2.5 adjusted for person-level covariates were 3% (95% confidence interval (CI): -2, 10) for a 30-day mean and 4% (95% CI: -3, 11.0) for a 60-day mean. The means of 7-day, 30-day, and 60-day exposures were weakly, positively, and nonsignificantly associated with the odds of C-reactive protein of greater than or equal to 3 mg/liter: adjusted odds ratios were 1.05 (95% CI: 0.96, 1.15), 1.12 (95% CI: 0.98, 1.29), and 1.12 (95% CI: 0.96, 1.32), respectively. Slightly stronger associations were observed in persons without other risk factors for elevated C-reactive protein, but this heterogeneity was not statistically significant. The authors' results are not compatible with strong effects of particulate matter exposures on population levels of C-reactive protein.

Tiotropium for stable chronic obstructive pulmonary disease: A meta-analysis

BACKGROUND

A systematic review was undertaken to evaluate the efficacy of tiotropium, a long acting anticholinergic drug, on clinical events, symptom scales, pulmonary function, and adverse events in stable chronic obstructive pulmonary disease (COPD).

METHODS

A systematic search was made of the Cochrane trials database, MEDLINE, EMBASE, CINAHL, and a hand search of 20 respiratory journals. Missing data were obtained from authors and the manufacturer. Randomised controlled trials of > or =12 weeks' duration comparing tiotropium with placebo, ipratropium bromide, or long acting beta2 agonists (LABA) were reviewed. Studies were pooled to yield odds ratios (OR) or weighted mean differences with 95% confidence intervals (CI).

RESULTS

Nine trials (8002 patients) met the inclusion criteria. Tiotropium reduced the odds of a COPD exacerbation (OR 0.73; 95% CI 0.66 to 0.81) and related hospitalisation (OR 0.68; 95% CI 0.54 to 0.84) but not pulmonary (OR 0.50; 95% CI 0.19 to 1.29) or all-cause (OR 0.96; 95% CI 0.63 to 1.47) mortality compared with placebo and ipratropium. Reductions in exacerbations and hospitalisations compared with LABA were not statistically significant. Similar patterns were evident for quality of life and symptom scales. Tiotropium yielded greater increases in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) from baseline to 6-12 months than did placebo, ipratropium, and LABA. Decline in FEV1 over 1 year was 30 ml (95% CI 7 to 53) slower with tiotropium than with placebo and ipratropium (data were not available for LABA). Reports of dry mouth and urinary tract infections were increased with tiotropium.

CONCLUSIONS

Tiotropium reduced COPD exacerbations and related hospitalisations, improved quality of life and symptoms, and may have slowed the decline in FEV1. Long term trials are warranted to evaluate the effects of tiotropium on decline in FEV1 and to clarify its role compared with LABA.

Inhaled tiotropium for stable chronic obstructive pulmonary disease

BACKGROUND

Tiotropium is a new anticholinergic therapy for chronic obstructive pulmonary disease (COPD) that differs from ipratropium by its functional relative selectivity for muscarinic receptor subtypes and which allows once-per-day dosing.

OBJECTIVES

To determine the efficacy of tiotropium on clinical endpoints such exacerbations and hospitalisations, symptom scales and pulmonary function compared to placebo and other bronchodilators used for stable COPD.

SEARCH STRATEGY

Randomised controlled trials (RCTs) were identified from the Cochrane Airways Review Group Specialised Register, a compilation of systematic searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and CINAHL, and hand searching of 20 respiratory journals. Bibliographies from included studies and reviews were searched. The date of the last search was October 2004.

SELECTION CRITERIA

Randomised clinical trials comparing tiotropium with placebo, ipratropium bromide, or long-acting ss2-agonists for greater than, or equal to, one month's duration.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data. Missing data were obtained from authors or the manufacturer of tiotropium. The data were analysed using the Cochrane Review Manager RevMan 4.2. Studies were pooled to yield weighted mean differences (WMD) or odds ratios (OR) and reported using 95% confidence intervals (CI).

MAIN RESULTS

From 69 identified references, nine RCTs (6,584 patients) met inclusion criteria. Tiotropium reduced the odds of a COPD exacerbation (OR 0.74; 95% CI 0.66 to 0.83) and related hospitalisations (OR 0.64; 95% CI 0.51 to 0.82) compared to placebo or ipratropium. When applied to an annual baseline risk of 45% for exacerbations and 10% for hospitalisation, the number of patients needed to treat with tiotropium for one year were 14 (95% CI 11 to 22) to prevent one exacerbation and 30 (95% CI 22 to 61) to prevent one hospitalisation compared to placebo and ipratropium. Reductions in these endpoints compared to long-acting ss2-agonists were not statistically significant. Similar patterns were evident for quality-of-life and symptom scales. Increases in FEV1 and FVC from baseline were significantly larger with tiotropium than with placebo, ipratropium and long-acting ss2-agonists over 6 to 12 months. The decline in trough FEV1 from steady state was 30 ml (95% CI 7 to 53 ml) less with tiotropium than with placebo or ipratropium over one year; no data on decline in FEV1 from steady state were available for long-acting ss2-agonists. Dry mouth was increased by tiotropium.

AUTHORS' CONCLUSIONS

Tiotropium reduced COPD exacerbations and related hospitalisations compared to placebo and ipratropium. It also improved health-related quality-of-life and symptom scores among patients with moderate and severe disease, and may have slowed decline in FEV1. Additional long-term studies are required to evaluate its effect on mortality and change in FEV1 to clarify its role in comparison to, or in combination with, long-acting ss2-agonists and to assess its effectiveness in mild and very severe COPD.

Effects of chewing gum on responses to routine painful procedures in children

In infants, sweet taste and sucking on a pacifier both have analgesic effects. Animal studies suggest that sweet taste may involve opioids, while rhythmic oral movements, as with a pacifier, increase the release of serotonin, which is involved in the gating of nociceptive afferents. The present study was designed to see if these effects produce an analgesic effect in children. Two studies were performed, during blood draws in a pediatric test center in 7- to 12-year-old children, and during vaccination at school in 9- to 11-year-old children. Using unsweetened or sweetened chewing gum, there were four groups: control, sweet, chew, and sweet plus chew. Overall, there was no effect of either sweet taste or chewing on pain responses. However, in boys sweet taste tended to increase pain ratings, but only in conjunction with chewing, while in girls sweet taste tended to decrease pain ratings in conjunction with chewing and increased them in the absence of chewing. Ratings of pain intensity and affective state were correlated. Affective state before the painful stimulus was related to pain response in the girls and in the boys in the test center, but not in the schools. In the schools, the presence of peers may have influenced the ratings.

Beta(2)-adrenoceptor polymorphism and body mass index are associated with adult-onset asthma in sedentary but not active women

STUDY OBJECTIVE

Beta(2)-adrenoceptor Gly16 polymorphism has been associated with asthma severity and beta(2)-adrenoceptor receptor downregulation, but not with the diagnosis of asthma. Glu27 polymorphism may limit beta(2)-adrenoceptor downregulation and predict body mass index (BMI), particularly among sedentary persons. In addition, BMI predicts asthma. We hypothesized that these DNA sequence variants predict adult-onset asthma only in sedentary women.

DESIGN

Nested case-control study.

SETTING

Nurses' Health Study, a large, prospective cohort study with participants throughout the United States.

PARTICIPANTS

Among lifelong nonsmokers, 171 women with adult-onset, medication-requiring asthma and 137 age-matched control subjects.

MEASUREMENTS

Physical activity and BMI were self-reported by previously validated questionnaire items. Genomic DNA was obtained from buccal brushings collected via first-class mail.

RESULTS

Of 76 sedentary women, the adjusted odds ratios of Gly16 allele were 7.4 (p = 0.047) for asthma and 13.8 (p = 0.02) for steroid-requiring asthma. No similar associations were observed among 232 active women (p = 0.91). Sedentary individuals with both Gly16 and Glu27 alleles had a less elevated risk for asthma. BMI was associated with asthma and Glu27 allele among sedentary women.

CONCLUSION

This exploratory analysis suggests an important gene/environment interaction for asthma involving physical activity level. Further study in larger populations is warranted to confirm if sedentary lifestyle unmasks a genetic risk for asthma.

Neighborhood poverty and the resurgence of tuberculosis in New York City, 1984-1992

OBJECTIVES

The resurgence of tuberculosis (TB) in NewYork City has been attributed to AIDS and immigration; however, the role of poverty in the epidemic is unclear. We assessed the relation between neighborhood poverty and TB at the height of the epidemic and longitudinally from 1984 through 1992.

METHODS

Census block groups were used as proxies for neighborhoods. For each neighborhood, we calculated TB and AIDS incidence in 1984 and 1992 with data from the Bureaus of Tuberculosis Control and AIDS Surveillance and obtained poverty rates from the census.

RESULTS

For 1992, 3,343 TB cases were mapped to 5,482 neighborhoods, yielding a mean incidence of 46.5 per 100,000. Neighborhood poverty was associated with TB (relative risk = 1.33; 95% confidence interval = 1.30, 1.36 per 10% increase in poverty). This association persisted after adjustment for AIDS, proportion foreign born, and race/ethnicity. Neighborhoods with declining income from 1980 to 1990 had larger increases in TB incidence than did neighborhoods with increasing income.

CONCLUSIONS

Leading up to and at the height of the TB epidemic in New York City, neighborhood poverty was strongly associated with TB incidence. Public health interventions should target impoverished areas.

Pacifier use, early weaning, and cry/fuss behavior: a randomized controlled trial

CONTEXT

The World Health Organization and the United Nations Children's Fund strongly discourage use of pacifiers because of their perceived interference with breastfeeding. Observational studies have reported a strong association between pacifier use and early weaning, but such studies are unable to determine whether the association is causal.

OBJECTIVES

To test whether regular pacifier use is causally related to weaning by 3 months postpartum and to examine differences in results according to randomized intervention allocation vs observational use or nonuse of pacifiers.

DESIGN

Double-blind, randomized controlled trial conducted from January 1998 to August 1999.

SETTING

Postpartum unit of a university teaching hospital in Montreal, Quebec.

PARTICIPANTS

A total of 281 healthy, breastfeeding women and their healthy, term singleton infants.

INTERVENTIONS

Participants were randomly allocated to 1 of 2 counseling interventions provided by a research nurse trained in location counseling. The experimental intervention (n = 140) differed from the control (n = 141) by recommending avoidance of pacifier use and suggesting alternative ways to comfort a crying or fussing infant.

MAIN OUTCOME MEASURES

Early weaning, defined as weaning within the first 3 months, compared between groups; 24-hour infant behavior logs detailing frequency and duration of crying, fussing, and pacifier use at 4, 6, and 9 weeks.

RESULTS

A total of 258 mother-infant pairs (91.8%) completed follow-up. The experimental intervention increased total avoidance of pacifier use (38.6% vs 16.0% in the control group), reduced daily use (40.8% vs 55.7%), and decreased the mean number of pacifier insertions per day (0.8 vs 2.4 at 4 weeks [P<.001]; 0.8 vs 3.0 at 6 weeks [P<.001]; and 1.3 vs 3.0 at 9 weeks [P =.004]). In the analysis based on randomized intervention allocation, the experimental intervention had no discernible effect on weaning at 3 months (18.9% vs 18.3% in the experimental vs control group; relative risk [RR], 1.0; 95% confidence interval [CI], 0.6-1.7), and no effect was observed on cry/fuss behavior (in the experimental vs control groups, respectively, total daily duration, 143 vs 151 minutes at 4 weeks [P =.49]; 128 vs 131 minutes at 6 weeks [P =.81]; and 110 vs 104 minutes at 9 weeks [P =.58]). When randomized allocation was ignored, however, we observed a strong observational association between exposure to daily pacifier use and weaning by 3 months (25.0% vs 12.9% of the exposed vs unexposed groups; RR, 1.9; 95% CI, 1.1-3.3).

CONCLUSIONS

We found a strong observational association between pacifier use and early weaning. No such association was observed, however, when our data were analyzed by randomized allocation, strongly suggesting that pacifier use is a marker of breastfeeding difficulties or reduced motivation to breastfeed, rather than a true cause of early weaning.

A clinical comparison of the safety and efficacy of MultiHance (gadobenate dimeglumine) and Omniscan (Gadodiamide) in magnetic resonance imaging in patients with central nervous system pathology

RATIONALE AND OBJECTIVES

The safety and diagnostic efficacy of MultiHance (gadobenate dimeglumine) in the central nervous system (CNS) were evaluated in a double-blind, multicenter, phase III clinical trial.

METHODS

Two hundred five patients highly suspected of having a CNS lesion (by previous imaging exam) were enrolled at 16 sites in the United States. Patients were randomized to one of three incremental dosing regimens. Magnetic resonance imaging with Omniscan (gadodiamide) at doses of 0.1 and 0.3 mmol/kg was compared with MultiHance (gadobenate dimeglumine) at doses of 0.05 and 0.15 mmol/kg and at 0.1 and 0.2 mmol/kg.

RESULTS

Compared with predose images alone, efficacy was demonstrated in each of the gadobenate dimeglumine and gadodiamide groups (single and cumulative doses) as indicated by the level of diagnostic information, number of lesions detected, and contrast-to-noise ratio measurements. The level of diagnostic information from gadobenate dimeglumine at 0.1 mmol/kg was equivalent to that with gadodiamide at the same dose. One of the two blinded reviewers found equivalence between the gadobenate dimeglumine 0.05 mmol/kg dose and gadodiamide at 0.1 mmol/kg. Both reviewers found the level of diagnostic information to be equivalent after the second dose of contrast for all three dosing regimens. The cumulative doses of gadobenate dimeglumine were well tolerated and as safe as gadodiamide.

CONCLUSIONS

Gadobenate dimeglumine is comparable to gadodiamide in terms of safety and efficacy for imaging of CNS lesions, with a possible advantage in imaging applications owing to enhanced T1 relaxivity.

Contact and nutrient caregiving effects on newborn infant pain responses

To understand how the 'caregiving context' could affect responses to procedural pain, the authors sought to determine whether (1) the combined effects of sweet taste and holding (caregiving contact) were greater than the effects of either alone, (2) any combined effects were additive or interactive, and (3) the interventions had similar effects on behavioral (crying and facial activity) and physiological (heart rate, vagal tone) responses to the heel-stick procedure in newborn infants in a randomized two-factorial intervention trial. Eighty-five normally developing newborn infants were studied with a mean gestational age of 39.4 weeks on the 2nd or 3rd day of life. Infants were randomized in blocks of eight to receive (1) no holding and water taste (control participants), (2) no holding and sucrose taste (sucrose group), (3) holding and water taste (holding group), or (4) holding and sucrose taste (holding and sucrose group). Crying was reduced significantly by taste and holding, and the interventions combined additively. Facial activity was only significantly reduced by holding. For physiological measures, the interventions interacted with each other and preintervention levels to reduce heart rate and lower vagal tone more during the procedure in infants in whom heart rate and vagal tone were higher before intervention. Consequently, sweet taste and holding interventions combined in complex ways when acting on different behavioral and physiological response systems to modify stressful pain experiences. The results suggest that providing a caregiving context when painful procedures are performed may be a simple and practical method of reducing pain experience in infants, and that no one measure captures these effects.

Methyl-xanthines for exacerbations of chronic obstructive pulmonary disease

BACKGROUND

International guidelines currently recommend the use of methyl-xanthines for exacerbations of chronic obstructive pulmonary disease (COPD) for patients who have incomplete responses to bronchodilators. However, available clinical trials are small and underpowered to evaluate the benefits and risks of methyl-xanthines in this acute setting.

OBJECTIVES

To determine the benefit of methyl-xanthines compared to standard care for COPD exacerbations.

SEARCH STRATEGY

Randomised controlled trials (RCTs) were identified from the Cochrane Airways Review Group COPD Register which is a compilation of systematic searches of CINAHL, EMBASE, MEDLINE and CENTRAL and hand searching of 20 respiratory journals. In addition, primary authors and content experts were contacted to identify eligible studies. Bibliographies from included studies, known reviews and texts were also searched.

SELECTION CRITERIA

Only RCTs were eligible for inclusion. Studies were included if patients presented with acute COPD exacerbations and were treated with either methyl-xanthines (oral or intravenous) or placebo (with or without standard care) early in the acute treatment. Studies also needed to report either pulmonary function or admission results. Two reviewers independently selected potentially relevant articles and selected articles for inclusion. Methodological quality was independently assessed by two reviewers.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers if the authors were unable to verify the validity of information. Missing data were obtained from authors or calculated from other data presented in the paper. The data were analysed using the Cochrane Review Manager 4.0.4 Studies were pooled to yield weighted mean differences (WMD) or odds ratios (OR) and reported using 95% confidence intervals (95%CI).

MAIN RESULTS

From 28 identified references, 4 RCTs met inclusion criteria (172 patients). Mean change in forced expiratory volume in one second (FEV1) at 2 hours was similar in methyl-xanthine and placebo groups (FEV1 WMD: -8 ml; 95% CI: -85 to 69 ml). The only study to report hospitalization rates showed a non-significant reduction with methyl-xanthines (OR: 0.3; 95% CI: 0.1 to 1.8) among 39 patients. Patients receiving methyl-xanthines had similar improvements in symptom scores, but reported more gastrointestinal side effects (OR: 5.3; 95% CI: 1.3 to 21.0) than patients receiving placebo.

REVIEWER'S CONCLUSIONS

There is no evidence to support the routine use of methyl-xanthines for COPD exacerbations. Methyl-xanthines do not appreciably improve FEV1 during COPD exacerbations and cause adverse effects; evidence of their effect on admissions is limited.

Behavioral and physiological responsivity, sleep, and patterns of daily cortisol production in infants with and without colic

To describe the behavioral and physiological responses associated with colic, the responses of 20 two-month-old infants with and 20 without colic were studied during a physical examination. Parents kept a diary of infant behaviors (including crying and fussing) for 3 days following the visit. Using Wessel, Cobb, Jackson, Harris, & Detwiler criteria, colic was defined as fussing/crying for 3 hr or more on each of the 3 days. Behavioral data coded by "blind" observers showed that during the physical exam, colic infants cried twice as much, cried more intensely, and were more inconsolable than were control infants. Despite these behavioral differences, heart rate, vagal tone, and cortisol measures indicated no appreciable difference in physiological responsivity for the two groups. At home, parents collected saliva cortisol samples at wakeup, midmorning, midafternoon, and evening for 2 days. In a finding similar to that shown by the laboratory data, the colic and control infants did not have different levels of daily average cortisol. These laboratory and home data provide no evidence of greater responsivity in the physiological substrate of difficult temperament for colic infants and are consistent with evidence of similarity in temperament once colic is resolved. At home, compared with control infants, colic infants did display a blunted rhythm in cortisol production. By diary, they also slept about 2 hr less per day than did control infants. Nighttime sleep was still significantly different when fussing/crying was statistically controlled. These data suggest that colic might be associated with a disruption or delay in the establishment of the circadian rhythm in activity of the hypothalamic-pituitary-adrenocortical axis and associated sleep-wake activity.

Sudden-onset asthma exacerbations: clinical features, response to therapy, and 2-week follow-up. Multicenter Airway Research Collaboration (MARC) investigators

Sudden-onset asthma exacerbations may have different triggers and responses to treatment than slower-onset exacerbations. The authors studied this hypothesis among patients with severe asthma exacerbations. The Multicenter Airway Research Collaboration prospectively enrolled patients presenting to 64 North American emergency departments with asthma exacerbations. Of 1,847 patients aged 18-54 yrs, 900 had severe exacerbations (peak expiratory flow rate (PEFR) <50% predicted or hospitalized without PEFR). These patients were divided into sudden-onset (< or =3 h of symptoms) and slower-onset (>3 h of symptoms) groups. Fourteen per cent (95% confidence interval, 11-16%) of patients with severe asthma exacerbations had sudden-onset exacerbations. Sudden-onset patients were similar to slower-onset patients, except triggers of their exacerbations were more often respiratory allergens, exercise or psychosocial stress and less often respiratory infections. Sudden-onset patients were more likely to have used oral beta-agonists and salmeterol in the preceding 4 weeks. Although initial PEFRs and management were similar, sudden-onset patients had a greater improvement in PEFR (35 versus 28% p<0.001). Sudden-onset patients were less often discharged on systemic corticosteroids, but had similar 2-week relapse rates compared with slower-onset patients. Among patients presenting with severe asthma exacerbations, sudden-onset exacerbations had a different pattern of triggers and greater improvement with treatment than slower-onset exacerbations.

[The ice storm: an opportunity to study the effects of prenatal stress on the baby and the mother.]

Over the last several years, studies have shown that stressful experiences during the pregnancy can predict levels of neurological development, as well as cognitive and psychological functioning, during childhood and adulthood. For example, Mednick (1997) has been studying the effects of a major earthquake in China on the psychological and intellectual development of the unborn child. Twenty-three years after the quake, significant differences have been found between the earthquake group and a control group born one year later in terms of intellectual functioning, depression, and the size of certain brain regions. Less severe events, such as a divorce or job loss during the pregnancy, may also increase the risk of obstetric complications and may have an effect on the baby's neurological well being, weight and head circumference at birth. Death of the baby's father during the pregnancy and natural disasters have both been associated with increased rates of depression, schizophrenia and criminality in adulthood. Several of these same effects have been found in studies of prenatal stress in non-human primates. Many of these studies suggest that the second trimester of pregnancy is a particularly critical period during which stressful events may compromise development of the fetus. Methodological constraints limit research on prenatal maternal stress. Animal studies are able to control for pre- and postnatal environments. However, animal studies have limited generalizability to humans for whom numerous risk and protective factors are in operation. Studies of human pregnancies cannot randomly assign subjects to stress conditions. Maternal personality and temperament may be associated with characteristics of a woman's child not only through genetic transmission of personality, but possibly also through differential exposure to difficult life conditions which may, in part, be self-imposed. In addition, studies of prenatal life events in humans have severely restricted variance; very large samples of women must be screened to identify even small numbers of women who have experienced major life events during the pregnancy. Finally, follow-back studies which show an association between prenatal events and later rates of mental illness, do not include timely evaluations of actual rates of exposure to the event, nor the pregnant woman's subjective or biological reactions to the event. In this paper, we present a review of the literature on prenatal maternal stress followed by a discussion of how the January 1998 Québec ice storm could be used to study the mechanisms by which prenatal stress may influence mental health outcomes in the unborn child.

Differential calming responses to sucrose taste in crying infants with and without colic

BACKGROUND

Colic is a behavioral syndrome of early infancy of unknown etiology whose core symptom is increased crying. Both clinical anecdotal descriptions and controlled observations converge in suggesting that a defining characteristic of the crying behavior is the longer duration of the crying bouts, especially during the second month of life when colic is at its peak. This implies that, once infants with colic begin crying, they do not calm as well as infants without colic. To investigate this difference objectively, we used response to sucrose taste as a probe of colic-normal differences in regulation of crying for three reasons. First, sucrose taste has been shown to be a potent regulator of crying in human newborns. Second, convergent evidence from studies in both nonhuman and human infants suggests that sucrose calming reflects the function of central distress regulatory systems that are opioid-dependent. Third, effectiveness of sucrose calming diminishes in normal infants by 4 to 6 weeks of age, consistent with the developmental increase in crying duration common to infants with and without colic. Consequently we predicted that, if the regulation of crying by sucrose taste is relevant to the crying of infants with colic, calming responses to sucrose taste should be less effective in 6-week-old infants with colic compared with those without.

OBJECTIVES

To investigate the clinical observation that infants with and without colic differ in their ability to regulate their crying behavior, our primary objective was to determine if there were differential crying responses to intraoral sucrose tastes (relative to water) in crying infants with and without colic. Based on previous studies of calming responses to sucrose taste, it was predicted that sucrose-specific calming before a feeding would be less effective in infants with colic than in those without. A secondary and more exploratory aim was to assess calming responses to sucrose (relative to water) on spontaneous crying after a feed in both groups.

METHODS

Nineteen infants meeting modified Wessel's criteria for colic were compared with 19 age- and sex-matched normal infants without colic in a within-subject controlled observation of calming and mouthing responses to both intraoral sucrose and water tastes. Both before and after two feedings on the same day, each infant was observed until she or he cried continuously for 15 consecutive seconds, at which time three 250-microL tastes of 48% sucrose solution or sterile water were administered 30 seconds apart, and infant responses videotaped. Outcome measures derived from second-by-second coding of the videorecordings were percent time crying per minute for 4 minutes and percent time mouthing per minute for 2 minutes after stimulus administration.

RESULTS

As predicted, the crying of infants with colic was less affected than the crying of infants without colic after sucrose but not water tastes before feedings. After feedings, the crying of infants with colic was less affected than the crying of infants without colic for both sucrose and water tastes, and sucrose was more effective than water in both groups of infants. These calming differences could not be attributed to differences in mouthing responses because the calming effects persisted after mouthing ceased, and there were no differences in mouthing responses between groups before or after feedings.

CONCLUSIONS

As in newborns, a significant calming effect of sucrose taste that persisted beyond the cessation of mouthing could be elicited in crying 6-week-old infants, but it required a stronger taste stimulus to do so. As predicted, infants with colic were less effectively calmed by sucrose taste than infants without. These differential effects could not be accounted for by differences in crying when the stimulus was applied or by differences in mouthing behavior. Before a feed, these differences in calming were specific to sucrose taste. After a feed, infants with c

The response of crying newborns to sucrose: is it a "sweetness" effect?

Intraoral sucrose (and other sweet carbohydrates) induce rapid and sustained calming in crying newborns and transiently increase mouthing and hand-mouth contact ("sucrose effects"). To investigate whether these effects are due to the sweetness of sucrose, 60 crying newborns were randomized to receive 250 microL of 24% sucrose solution, 0.12% of aspartame solution of equivalent sweetness (to adults), or 24% polycose, a soluble carbohydrate that is only very slightly sweet (to adults), as well as water in a mixed parallel crossover design. Relative to water, sucrose persistently reduced crying, and transiently increased mouthing and hand-mouth contact, as previously demonstrated. Aspartame also reduced crying, and transiently increased mouthing and hand-mouth contact, virtually mimicking the time course and the magnitude of the effects obtained in response to sucrose. By contrast, polycose solution had no specific effects on crying, mouthing, or hand-mouth contact. The results imply that the responses of crying newborns to intraoral sucrose are neither specific to sucrose nor to the general class of carbohydrates, and that these effects are more appropriately understood as "sweetness" effects.

Colic and crying syndromes in infants

Colic or excessive crying is one of the most frequent problems presented to pediatricians by new parents. Organic disease accounts for <5% of infants presenting with colic syndrome. Colic may be best viewed as a clinical manifestation of normal emotional development, in which an infant has diminished capacity to regulate crying duration.

Crying in the first year of life: good news in the midst of distress

Excessive crying and colic in the first 3 months of life remain as mysterious and unsolved clinical problems. The mystery is contributed to by the relative lack of long-term follow-up studies. The findings from four new follow-up studies of infants with prior colic are analyzed in an attempt to derive a clearer picture of what 'life after colic' might be like for parents, infants, and their interactions. The bad news is that, for a subgroup of infants and parents, especially those with substantial additional risk factors, early excessive crying may not resolve, but evolve into a more generalized 'persistent mother-infant distress' syndrome. For some mothers of infants with colic, the risk of depressive symptoms or decreased self-efficacy may be increased. However, there appears to be good news for a substantial majority of infants with colic and for their parents. This includes a significant reduction over time in the amount of crying, intact parental and infant capacities to be responsive in interactive contexts, no significant maternal stress, and normal attachment relationships.

Run-in periods in randomized trials: implications for the application of results in clinical practice

Prerandomization run-in periods are being used to select or exclude patients in an increasing number of clinical trials, but the implications of run-in periods for interpreting the results of clinical trials and applying these results in clinical practice have not been systematically examined. We analyzed illustrative examples of reports of clinical trials in which run-in periods were used to exclude noncompliant subjects, placebo responders, or subjects who could not tolerate or did not respond to active drug. The Physicians' Health Study exemplifies the use of a prerandomization run-in period to exclude subjects who are nonadherent, while recent trials of tacrine for Alzheimer disease and carvedilol for congestive heart failure typify the use of run-in periods to exclude patients who do not tolerate or do not respond to the study drug. The reported results of these studies are valid. However, because the reported results apply to subgroups of patients who cannot be defined readily based on demographic or clinical characteristics, the applicability of the results in clinical practice is diluted. Compared with results that would have been observed without the run-in period, the reported results overestimate the benefits and underestimate the risks of treatment, underestimate the number needed to treat, and yield a smaller P value. The Cardiac Arrhythmia Suppression Trial exemplifies the use of an active-drug run-in period that enhances clinical applicability by selecting a group of study subjects who closely resembled patients undergoing active clinical management for this problem. Run-in periods can dilute or enhance the clinical applicability of the results of a clinical trial, depending on the patient group to whom the results will be applied. Reports of clinical trials using run-in periods should indicate how this aspect of their design affects the application of the results to clinical practice.

A one-hour active coping stressor reduces small bowel transit time in healthy young adults

OBJECTIVE

To examine the effect of a prolonged active coping stressor on the transit of a substance from the mouth through small intestine in normal human volunteers.

METHOD

Twelve healthy undergraduate males were administered 10 g of the nonabsorbable carbohydrate lactulose in two experimental sessions. In normal individuals, lactulose produces hydrogen gas upon exposure to bacteria residing in the colon. Repeated measurements of breath hydrogen were obtained for 2 hours. In one session, subjects rested quietly for the 2-hour period. In the other counterbalanced session, subjects avoided mild electric shocks by playing videogames for the first hour.

RESULTS

Stress produced a statistically and clinically significant reduction in mean transit time, from 79 to 55 minutes. The magnitude of stress-induced reduction in small bowel transit time was significantly correlated with change in an index of cardiac sympathetic activity, pulse transit time.

CONCLUSIONS

A prolonged active coping stressor with minimal motor requirements produced a decrease in small bowel transit time comparable with that observed in several studies of the effects of physical exercise and in comparisons between normal controls and patients with diarrhea-predominant irritable bowel syndrome.

Differential response to intraoral sucrose, quinine and corn oil in crying human newborns

Intraoral sucrose induces rapid and sustained calm in crying newborns and transiently increases mouthing and hand-mouth contact. To determine whether these effects are specific to sucrose and to explore which properties of orogustatory stimuli might contribute to this effect, 60 crying newborns were randomized to receive 250 ul of 24% sucrose solution, 0.25% quinine hydrochloride solution, or corn oil as well as water in a mixed parallel crossover design. Relative to water, sucrose persistently reduced crying, and transiently increased mouthing and hand-mouth contact as previously demonstrated. While quinine produces a "disgust" face in calm infants, in crying infants it transiently decreased crying and increased mouthing, but did not affect hand-mouth contact. Corn oil had no specific effect on crying, mouthing or hand-mouth contact. The results imply that crying newborns respond differentially to orogustatory stimuli, that taste "salience" rather than positive hedonic valence may account for initial crying reduction and increased mouthing, and that these behavioral effects are not induced by at least one lipid nutrient.

Acalculous gallbladder disease: US evaluation after slow-infusion cholecystokinin stimulation in symptomatic and asymptomatic adults

PURPOSE

To evaluate the measurement with ultrasonography (US) of the gallbladder ejection fraction after slow-infusion cholecystokinin stimulation in patients with biliary symptoms and in individuals without symptoms.

MATERIALS AND METHODS

Gallbladder volumes were calculated in 60 healthy volunteers after a 30-minute infusion of sincalide. The time to maximum response, the gallbladder ejection fraction, and the rate of initial contraction were obtained at US. A total of 100 symptomatic patients were evaluated with this technique. Reference standards included surgical outcome or results of clinical follow-up of at least 1 year.

RESULTS

The average ejection fraction +/- 2 standard deviations was 80% +/- 30. A fraction greater than 60% was considered to be a normal response to cholecystokinin stimulation. There was no statistically significant sex difference. Slow infusion did not produce any side effects. A sensitivity of 75% and a specificity of 100% for determination of gallbladder ejection fraction at US were obtained in patients with surgical and histopathologic proof of disease.

CONCLUSION

The slow-infusion method is reliable, safe, and reproducible in evaluating gallbladder contraction. The cholecystokinin-stimulated gallbladder ejection fraction test may be useful in determining which patients could benefit from surgery.

Acoustic characteristics of naturally occurring cries of infants with "colic"

Although infantile colic has long been defined by a perceived excessive amount of crying, acoustic attributes of the cry sound may also contribute to perceptions that this early social behavior is excessive or problematic. From an original sample of 76 infants (38 infants referred to physicians for problematic crying, or "colic," and 38 pair-matched comparison infants), 48 infants who produced naturally occurring cry bouts both before and after an evening feeding were studied: 11 infants with Wessel's colic, 15 infants with non-Wessel's colic, and 22 comparison infants. Standard and vociferous cry segments were selected from up to 2 min of tape-recorded crying for spectrum analysis. Vociferous cry segments had a longer duration, a higher fundamental frequency, and a greater percentage of dysphonation than did standard segments. No differences between infant groups were found in cries before feeding. After feeding, infants who were problematic criers, independent of Wessel's criteria, showed a greater percentage of dysphonation in the vociferous cry segment than did comparison infants. This finding resulted from a decrease in dysphonation in the cries of comparison infants after feeding and an increase in those of infants with non-Wessel's colic. The dominant frequency also increased after feeding in the vociferous cries of infants with Wessel's colic, resulting in these infants having higher-pitched cries after feeding than infants in the other 2 groups. Results indicate that infants who are perceived to have problematic crying have objectively different acoustic features in their cry sounds that are particularly aversive, and that complaints about excessive crying cannot be accounted for simply on the basis of reporting bias in overly concerned or emotionally labile parents.

Nonadherence in tuberculosis treatment: predictors and consequences in New York City

BACKGROUND

Poor adherence to antituberculosis treatment is the most important obstacle to tuberculosis control.

PURPOSE

To identify and analyze predictors and consequences of nonadherence to antituberculosis treatment.

PATIENTS AND METHODS

Retrospective study of a citywide cohort of 184 patients with tuberculosis in New York City, newly diagnosed by culture in April 1991-before the strengthening of its control program-and followed up through 1994. Follow-up information was collected through the New York City tuberculosis registry. Nonadherence was defined as treatment default for at least 2 months.

RESULTS

Eighty-eight of the 184 (48%) patients were nonadherent. Greater nonadherence was noted among blacks (unadjusted relative risk [RR] 3.0, 95% confidence interval [CI] 1.1 to 8.6, compared with whites), injection drug users (RR 1.5, 95% CI 1.1 to 2.0), homeless (RR 1.4, 95% CI 1.0 to 1.8), alcoholics (RR 1.4, 95% CI 1.0 to 1.9), and HIV-infected patients (RR 1.4, 95% CI 1.1 to 1.9); also, census-derived estimates of household income were lower among nonadherent patients (P = 0.018). In multivariate analysis, only injection drug use and homelessness predicted nonadherence, yet 46 (39%) of 117 patients who were neither homeless nor drug users were nonadherent. Nonadherent patients took longer to convert to negative culture (254 versus 64 days, P < 0.001), were more likely to acquire drug resistance (RR 5.6, 95% CI 0.7 to 44.2), required longer treatment regimens (560 versus 324 days, P < 0.0001), and were less likely to complete treatment (RR 0.5, 95% CI 0.4 to 0.7). There was no association between treatment adherence and all-cause mortality.

CONCLUSIONS

In the absence of public health intervention, half the patients defaulted treatment for 2 months or longer. Although common among the homeless and injection drug users, the problem occurred frequently and unpredictably in other patients. Nonadherence may contribute to the spread of tuberculosis and the emergence of drug resistance, and may increase the cost of treatment. These data lend support to directly observed therapy in tuberculosis.

Crying patterns in preterm infants

Healthy infants born at term cry most in the first three months of life, with a peak and increased crying in the evening during the second month. To determine whether the crying of preterm infants manifests similar features, the pattern of crying from 40 weeks gestational age through 24 weeks corrected age was described for 35 relatively healthy preterm infants born between 28 and 34 weeks gestational age. Despite their additional extra-uterine experience, they still cried significantly more after 40 weeks gestational age, with a peak and evening clustering at 6 weeks corrected age. The age of peak crying was not related to gestational age at birth, weight for gestational age, or a variety of perinatal and neurological indices. The results support the argument that the early-peak pattern is a robust maturational feature of early development and may be universal to human infancy.

Ethidium bromide binding to unstructured and structured 2' GMP

For disordered 2' GMP and 5' GMP the ethidium cation (Etd) was found to form 1:1 and 2:1 Eth:nucleotide complex. For alkali metal solution self-structured 2'GMP and 5'GMP Etd was found to form 1:1 and 2:1 Etd: order nucleotide complex. The best computer fit was obtained for a structured nucleotide stoichiometry of Na4(2'GMP)8. Binding constants for the Etd:disordered 2'GMP complexes were determined to be (1.6 +/- 0.1) x 10(4)M(-1) and 6.3 +/- 0.5 M(-1) at O degrees C and (1.1 +/- 0.2) x 10(4) M(-1) and 18 +/- 11M(-1) for 5'GMP at 5 degrees C for the 1:1 and 1:2 complex, respectively. For the 1:1 and 1:2 2'GMP:Etd species the enthalpies were determined to be -19.8 +/- 1.0 kcal/mole and 0.1 +/- 0.3 kcal/mole, respectively, and the entropies were -53.3 +/- 6.6 eu and 3.9 +/- 1.6 eu, respectively. Binding constants for the Etd: structured 2'GMP complex, assuming a complex with stoichoimetry (Na+)4 (2'GMP)8 for the structured unit, were determined to be (1.9 +/- 0.1) x 10(4)M(-1) and 5.8 +/- 0.6) x 10(2)M(-1), respectively at 0 degrees C.

"Sucrose analgesia" and diphtheria-tetanus-pertussis immunizations at 2 and 4 months

In human newborns, small amounts of sucrose reduce crying with procedural pain by about 50%. To determine whether "sucrose analgesia" could be extended to painful procedures beyond the newborn period, 57 infants were randomly assigned to receive three 250-microliters doses of 50% sucrose solution (g/100 mL) or water before their diphtheria-tetanus-pertussis immunizations at 2 and 4 months of age. Crying during and after injection was measured separately to determine whether sucrose modified crying during the noxious stimulus, recovery from the stimulus, or both. Sucrose was effective in reducing crying only from 83 to 69%, and the reduction was limited to the postinjection period. We conclude that, although sucrose continues to have some effect beyond the newborn period, the effect is limited to recovery from the noxious stimulus, is clinically modest, and is probably smaller than in the newborn period.

Do high doses of stimulants impair flexible thinking in attention-deficit hyperactivity disorder?

OBJECTIVE

To test the hypothesis that high doses of methylphenidate (MPH) impair cognitive flexibility in attention-deficit hyperactivity disorder (ADHD).

METHOD

A double-blind crossover design was used in an acute dosage trial to assess effects of three dosages (0.3, 0.6, and 0.9 mg/kg) of MPH on the performance of 17 ADHD children on five tasks designed to assess divergent thinking, perseveration, and ability to shift mental set. The tasks also assessed convergent thinking, problem solving, and speed and accuracy of processing.

RESULTS

There was minimal evidence of deleterious effects on flexible thinking or other cognitive processes, either in the ADHD group as a whole or in any subgroup. The most common pattern indicated linear improvement across dosages.

CONCLUSIONS

Under the acute dosage conditions used in this study, MPH doses up to 0.9 mg/kg had an increasingly positive effect on measures of mental flexibility and other cognitive processes. Rather than eliciting perseveration, MPH appeared to improve persistence. The generalized nature of the cognitive and motivational changes observed suggests that MPH acts on central, self-regulatory processes. Because effects of two or more daily doses can accumulate when MPH is prescribed in the clinical situation, clinical doses of more than 0.6 mg/kg were not recommended.

Supplementary carrying compared with advice to increase responsive parenting as interventions to prevent persistent infant crying

OBJECTIVE

To compare two interventions (supplementary carrying, increased parental responsiveness) introduced from birth for their effectiveness in reducing the amounts of crying in general community infants at 2, 6, and 12 weeks age.

DESIGN AND PARTICIPANTS

Mothers and infants in newborn wards of maternity hospitals were assigned to carrying intervention, responsiveness intervention, or control groups. Follow-up measures were used to confirm that the interventions were implemented and to determine their effects on infant crying. SETTING AND MEASUREMENTS: Diary measurements completed in the home were employed to measure the aspects of parental behavior targeted by the interventions. Audio recordings, diaries, and questionnaires assessed the amounts the infants cried and the impact of the crying on their mothers and the health services. Sample sizes at 6 weeks of age were 59 (carrying intervention), 57 (responsiveness intervention), and 94 infants (control group).

RESULTS

The carrying intervention successfully increased the amounts the infants were carried, particularly while settled, to the target levels. The responsiveness intervention led to more limited increases in carrying and to a modest increase in feeding frequency, but did not affect measures of parental interactiveness and play. No differences in amounts of crying and fussing were found between the three groups of infants on any of the measures. Subsidiary analyses confirmed that the dependent variable (infant fuss/crying) and main independent variable (carrying while settled) were not significantly correlated.

CONCLUSION

It is not, at present, possible to recommend either supplementary carrying or increased parental responsiveness as primary, preventative interventions to reduce infant crying.

Structure sensitivity of amino proton exchange in 2'- and 5' - guanosine monophosphate dianions

Proton NMR line broadening methods were used to determine the rates of amino proton exchange for disordered 2'- and 5' - GMP dianions in aqueous solutions containing tetramethylammonium (TMA+) cations. Replacing TMA+ with Na+ does not substantially alter the exchange rates, provided that H-bonded, Na(+)-directed tetramer structures are absent. Activation enthalpies (kcal/mol) and entropies (eu) for 2'-GMP are: delta H not equal to = 18.5 +/- 1.3, delta S not equal to = 9.6 +/- 4.2 for TMA+ salt at pH 8.10, and delta H not equal to = 14.7 +/- 2.6, delta S not equal to = -3.7 +/- 8.0 for the Na+ salt at pH 8.11. Extrapolated values of pseudo first-order rate constants at 25 degrees C are in the range of k = 1-10 sec-1. At suitable concentrations and temperatures, the Na+ salts of both 2'- and 5' - GMP formed stacked and unstacked tetramer units. Relative to the exchange kinetics observed for the disordered nucleotide, the exchange process in the tetramer units was catalyzed in half the amino protons and inhibited in the other half. The catalytic process (k > 10(3) sec-1) has been attributed to amino protons not involved in interbase H-bonding, where as the inhibited process (k < 10(-1) sec-1) was assigned to those protons which do form such bonds. The structure-catalyzed process in both the stacked and unstacked tetramers was manifested by a loss of NMR amino proton intensity due to weighted time-averaging with the resonance for bulk water. A bridging water molecule between an amino proton and a phosphate on an adjacent nucleotide in the tetramer unit may provide a mechanistic pathway for the structure-catalyzed process.

The effect of war on tuberculosis. Results of a tuberculin survey among displaced persons in El Salvador and a review of the literature

SETTING

During wartime, civilian populations usually experience a drop in caloric intake, disruption of housing, and a diminution in availability of medical services. These disturbances might be expected to result in increased reactivation of tuberculosis, which may result in increased transmission. Such privations occurred in El Salvador during its 1980-92 civil war, particularly among the 20% of the population, or over 1 million people, who were displaced.

OBJECTIVE

(1) To estimate the rate of transmission of tuberculosis among displaced Salvadorians prior to and during the war, and (2) to compare this result with experience in the literature.

DESIGN

(1) A tuberculin survey was conducted in El Salvador in July 1992 among all residents aged 1-30 years in 12 communities of formerly displaced persons. (2) The English language literature on tuberculosis during wartime was reviewed.

RESULTS

(1) Overall, 21.2% of the non-BCG vaccinated had significant tuberculin reactions, equivalent to an annual risk of infection of 2.3%. The trend in the annual risk of infection was upward over the latter 6 years of the war, stable over the first 6 years, and was downward prior to the war years. The estimated incidence of smear positive pulmonary tuberculosis was 125 per 100,000 or 3 times the reported rate for El Salvador. (2) A review of the literature showed consistent evidence for increased morbidity and mortality from tuberculosis during wartime. Increased transmission was suggested by those studies showing a rise in both incidence of tuberculous meningitis during war years and excess morbidity and mortality many years after a war. Two major population-based studies found no evidence of increased transmission based on the calculated annual risk of infection; however other studies examining younger or more severely affected populations, or following more prolonged wars, detected an apparent increase in the transmission of tuberculosis.

CONCLUSIONS

Conditions of war are associated with a rapid increase in morbidity and mortality from tuberculosis, which appears to result in increased transmission among populations most severely affected by war. This increased transmission will result in increased morbidity and mortality for many years, underscoring the need for improved tuberculosis control in the post-war period in countries such as El Salvador that have been devastated by war.

Effects of intra-oral sucrose on crying, mouthing and hand-mouth contact in newborn and six-week-old infants

To determine whether a single intra-oral administration of sucrose would calm infants and elicit mouthing and hand-mouth contact, crying newborn and six-week-old infants were given sucrose solution before one feed and sterile water before another in a cross-over trial. Six-week-old infants were also given sucrose and water after feeding. For the newborn infants, the calming effect was rapid, substantial and lasted for at least four minutes. Mouthing and hand-mouth contact increased, but for shorter durations. For the six-week-old infants, sucrose calmed for one minute only before feeding, but had no effects on mouthing or hand-mouth contact. The results imply that intra-oral sucrose has acute age-related effects on crying and suckling-feeding behaviour mediated by a pre-absorptive mechanism. Sucrose may tap a functional system for reducing distress related to feeding and/or regulation of infant state.