Effect of the Deposit Temperature of ZnO Doped with Ni by HFCVD.

The effect of the deposit temperature of zinc oxide (ZnO) doped with nickel (Ni) by hot filament chemical vapor deposition (HFCVD) technique is reported in this work. The technique allows depositing ZnO:Ni in short intervals (1 min). A deposit of undoped ZnO is used as a reference sample. The reference sample was deposited at 500 °C. The ZnO:Ni samples were deposited at 500 °C, 400 °C, 350 °C, and 300 °C. The samples were studied using structural, morphological, and optical characterization techniques. The Ni incorporation to the ZnO lattice was verified by the shift of the X-ray diffraction peaks, the Raman peaks, the band gap, and the photoluminescence measurements. It was found that the deposit temperature affects the structural, morphological, and optical properties of the ZnO:Ni samples too. The structure of the ZnO:Ni samples corresponds to the hexagonal structure. Different microstructures shapes such as spheres, sea urchins, and agglomerate were found in samples; their change is attributed to the deposit temperature variation. The intensity of the photoluminescence of the ZnO:Ni improves concerning the ZnO due to the Ni incorporation, but it decreases as the deposit temperature decreases.

Paediatric asthma hospital utilization varies by demographic factors and area socio-economic status.

OBJECTIVES: Associations of emergency department (ED) visits and hospital admissions for asthma in children with demographics and area socio-economic status (SES) were examined to evaluate long-term trends and identify vulnerable populations. STUDY DESIGN: Retrospective population-based trend and cross-sectional analyses. METHODS: Asthma hospital admissions (2000-2007) and ED visits (2005-2007) for children aged 0-14 years living in Orange County, California were linked with zip-code-level SES data (2000 US Census). Annual population estimates were obtained to calculate age-specific admissions and ED visit rates. Average annual percentage changes (AAPC) were calculated with joinpoint analyses. The risks of ED visits and hospital admissions were estimated from SES indicators with negative binomial regression. RESULTS: Rates of asthma hospital admissions and ED visits were highest among children aged 0-4 years, males and African Americans, and lowest among Asian/Pacific Islanders. African Americans and Hispanics/Latinos were more likely to be uninsured. Asthma admissions decreased significantly for all age groups over the study period. The greatest declines per 100,000 were among children aged 0-4 years (AAPC: -15.3%, 95% confidence interval -17.0% to -13.4%). Rates of hospital admissions and ED visits were significantly higher in low-SES groups. Hospital admission rates were 30-60% higher and ED visits were 80-90% higher in zip codes in the lowest tertile of median household income compared with the highest tertile of median household income. CONCLUSIONS: Paediatric asthma hospitalizations and ED visit rates are declining in Orange County. However, certain groups are disproportionately affected, including those living in areas with low SES. This information will help in targeting intervention strategies to children at highest risk for severe asthma episodes.

Organic compound characterization and source apportionment of indoor and outdoor quasi-ultrafine particulate matter in retirement homes of the Los Angeles Basin.

UNLABELLED: Quasi-ultrafine (quasi-UF) particulate matter (PM(0.25)) and its components were measured in indoor and outdoor environments at four retirement communities in Los Angeles Basin, California, as part of the Cardiovascular Health and Air Pollution Study (CHAPS). The present paper focuses on the characterization of the sources, organic constituents and indoor and outdoor relationships of quasi-UF PM. The average indoor/outdoor ratios of most of the measured polycyclic aromatic hydrocarbons (PAHs), hopanes, and steranes were close to or slightly lower than 1, and the corresponding indoor-outdoor correlation coefficients (R) were always positive and, for the most part, moderately strong (median R was 0.60 for PAHs and 0.74 for hopanes and steranes). This may reflect the possible impact of outdoor sources on indoor PAHs, hopanes, and steranes. Conversely, indoor n-alkanes and n-alkanoic acids were likely to be influenced by indoor sources. A chemical mass balance model was applied to both indoor and outdoor speciated chemical measurements of quasi-UF PM. Among all apportioned sources of both indoor and outdoor particles, vehicular emissions was the one contributing the most to the PM(0.25) mass concentration measured at all sites (24-47% on average). PRACTICAL IMPLICATIONS: Although people (particularly the elderly retirees of our study) generally spend most of their time indoors, a major portion of the PM(0.25) particles they are exposed to comes from outdoor mobile sources. This is important because, an earlier investigation, also conducted within the Cardiovascular Health and Air Pollution Study (CHAPS), showed that indoor-infiltrated particles from mobile sources are more strongly correlated with adverse health effects observed in the elderly subjects living in the studied retirement communities compared with other particles found indoors (Delfino et al., 2008).

Functional outcomes and 8-year survival after hip arthroscopy in patients with degenerative hip disease. / Resultados funcionales y supervivencia a ocho años de la artroscopia de cadera en pacientes con patología degenerativa de cadera.

BACKGROUND AND PURPOSE: The purpose of this study is to identify which variables may have a significant impact in mid-term survivorship following hip arthroscopy. METHODS: This a single-centre single-surgeon retrospective study including 102 patients who underwent a hip arthroscopy procedure between August 2007 and October 2011. Each subject completed three questionnaires at final follow- up: Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sport (HOS-S) and Modified Harris Hip Score (m-HHS). RESULTS: Thirty-nine patients (40 hips) were finally included in our study. Mean age was 43.1 ± 9.9 years with a three-year minimum follow-up (75.43 ± 25.2 months). Younger patients and those with a shorter duration of symptoms obtained significantly higher HOS-S and m-HSS scores. Patients who had undergone previous lumbar spinal surgery obtained significantly worse HOS-ADL scores. Patient acceptable symptom state (PASS) was achieved in 23 patients (57.5%) for m-HHS, 22 patients (55%) for HOS-ADL and 25 patients for HOS-S scores. No major complication was observed. Only four patients had minor complications. Mean survival time was 97.1 months (95% CI, 85.1 to 109.1 months), with a survival at 8 years of 69% (95% CI, 53% to 85%). CONCLUSIONS: Our findings suggest that hip arthroscopy is a safe procedure with acceptable functional outcomes after a long follow-up. Care should be taken when treating patients with prior lumbar surgery. LEVEL OF EVIDENCE: Level IV.

Obesity, waist size and prevalence of current asthma in the California Teachers Study cohort.

BACKGROUND: Obesity is a risk factor for asthma, particularly in women, but few cohort studies have evaluated abdominal obesity which reflects metabolic differences in visceral fat known to influence systemic inflammation. A study was undertaken to examine the relationship between the prevalence of asthma and measures of abdominal obesity and adult weight gain in addition to body mass index (BMI) in a large cohort of female teachers. METHODS: Prevalence odds ratios (ORs) for current asthma were calculated using multivariable linear modelling, adjusting for age, smoking and race/ethnicity. RESULTS: Of the 88 304 women in the analyses, 13% (n = 11,500) were obese (BMI > or = 30 kg/m(2)) at baseline; 1334 were extremely obese (BMI > or = 40 kg/m(2)). Compared with those of normal weight, the adjusted OR for adult-onset asthma increased from 1.40 (95% confidence interval (CI) 1.31 to 1.49) for overweight women to 3.30 (95% CI 2.85 to 3.82) for extremely obese women. Large waist circumference (>88 cm) was associated with increased asthma prevalence, even among women with a normal BMI (OR 1.37, 95% CI 1.18 to 1.59). Among obese women the OR for asthma was greater in those who were also abdominally obese than in women whose waist was < or = 88 cm (2.36 vs 1.57). Obese and overweight women were at greater risk of severe asthma episodes, measured by urgent medical visits and hospital admissions. CONCLUSIONS: This study confirms the association between excess weight and asthma severity and prevalence, and showed that a large waist was associated with increased asthma prevalence even among women considered to have normal body weight.

Repeated respiratory hospital encounters among children with asthma and residential proximity to traffic.

OBJECTIVE: The prevalence of adverse respiratory outcomes among children has been frequently associated with measurements of traffic-related exposures, and other data suggest asthma severity is worsened with residence near heavy traffic. We examined the association between neighbourhood traffic burden and repeated acute respiratory illnesses that required emergency department visits and/or hospitalisation for children with a primary or secondary diagnosis of asthma (89% acute bronchitis or pneumonia). METHODS: This is a hospital-based longitudinal study of a southern California urban catchment area around two adjacent children's hospitals. Subjects' home addresses were geocoded and linked to nearby traffic data. Recurrent event proportional hazard analysis was used to estimate the hazard of repeated hospital encounters. RESULTS: We found living within 300 metres of arterial roads or freeways increased risk of repeated hospital encounters in 3297 children age 18 years or less. At highest risk were children in the top quintile of traffic density (HR = 1.21; 95% CL 0.99 to 1.49) and those who had 750 metres or more of arterial road and freeway length within 300 metres of their residence (HR = 1.18; 95% CL 0.99 to 1.41). Associations between repeated hospital encounters and residence near heavy traffic were stronger in females than males and in children without insurance or who required government sponsored insurance than children with private insurance. The gender disparity was most notable among infants (age 0) and children ages 6-18 years. CONCLUSIONS: Results suggest exposure to traffic-related air pollution increases asthma severity as indicated by hospital utilisation. The finding in infants suggests this is an especially vulnerable population, although the validity of asthma diagnosis at this age is unknown. Females and children who do not have private insurance may also be more vulnerable to air pollution from traffic.

The relationship of respiratory and cardiovascular hospital admissions to the southern California wildfires of 2003.

OBJECTIVE: There is limited information on the public health impact of wildfires. The relationship of cardiorespiratory hospital admissions (n = 40 856) to wildfire-related particulate matter (PM(2.5)) during catastrophic wildfires in southern California in October 2003 was evaluated. METHODS: Zip code level PM(2.5) concentrations were estimated using spatial interpolations from measured PM(2.5), light extinction, meteorological conditions, and smoke information from MODIS satellite images at 250 m resolution. Generalised estimating equations for Poisson data were used to assess the relationship between daily admissions and PM(2.5), adjusted for weather, fungal spores (associated with asthma), weekend, zip code-level population and sociodemographics. RESULTS: Associations of 2-day average PM(2.5) with respiratory admissions were stronger during than before or after the fires. Average increases of 70 microg/m(3) PM(2.5) during heavy smoke conditions compared with PM(2.5) in the pre-wildfire period were associated with 34% increases in asthma admissions. The strongest wildfire-related PM(2.5) associations were for people ages 65-99 years (10.1% increase per 10 microg/m(3) PM(2.5), 95% CI 3.0% to 17.8%) and ages 0-4 years (8.3%, 95% CI 2.2% to 14.9%) followed by ages 20-64 years (4.1%, 95% CI -0.5% to 9.0%). There were no PM(2.5)-asthma associations in children ages 5-18 years, although their admission rates significantly increased after the fires. Per 10 microg/m(3) wildfire-related PM(2.5), acute bronchitis admissions across all ages increased by 9.6% (95% CI 1.8% to 17.9%), chronic obstructive pulmonary disease admissions for ages 20-64 years by 6.9% (95% CI 0.9% to 13.1%), and pneumonia admissions for ages 5-18 years by 6.4% (95% CI -1.0% to 14.2%). Acute bronchitis and pneumonia admissions also increased after the fires. There was limited evidence of a small impact of wildfire-related PM(2.5) on cardiovascular admissions. CONCLUSIONS: Wildfire-related PM(2.5) led to increased respiratory hospital admissions, especially asthma, suggesting that better preventive measures are required to reduce morbidity among vulnerable populations.

Breast cancer, passive and active cigarette smoking and N-acetyltransferase 2 genotype.

The relationship of breast cancer to cigarette smoking is inconsistent in the literature, possibly due in part to heterogeneity in carcinogen metabolism. N-acetyltransferase 2 (NAT2) enzyme activity is believed to play a role in the activation of tobacco smoke carcinogens. We examined the effect of NAT2 genetic polymorphisms on risk of breast cancer from active and passive smoking. Women were recruited from those who had suspicious breast masses detected clinically and/or mammographically. Questionnaire data were collected prior to biopsy diagnosis to blind subjects and interviewers. Histopathology showed 113 cases with mammary carcinoma (30 carcinoma in situ) and 278 controls with benign breast disease. NAT2 genotype was determined using allele-specific polymerase chain reaction amplification to detect slow acetylator mutations. Effects of passive and active tobacco smoke and of NAT2 genotype on breast cancer risk were examined with logistic regression controlling for known risk factors. Models first included all controls, and subsequently 107 with no or low risk (normal breast or no hyperplasia), and finally 148 with high risk (hyperplasia, atypical hyperplasia, complex fibroadenomas). Referents had no active or passive smoke exposure. We found no association between breast cancer risk and NAT2, smoking status (never, former, current), smoking duration, or cigarettes per day. There were no effects of passive exposure among never-smokers. Models were unchanged across control groups. There were no statistical interactions between tobacco smoke exposure and NAT2. The results were similar when restricting the analysis to invasive cancers. These findings do not support the hypothesis that NAT2 is a risk factor for breast cancer or that it alters susceptibility to tobacco smoke.

Ozone exposure assessment in a southern California community.

An ozone exposure assessment study was conducted in a Southern California community. The Harvard ozone passive sampler was used to monitor cohorts of 22 and 18 subjects for 8 weeks during the spring and fall of 1994, respectively. Ozone exposure variables included 12-hr personal O3 measurements, stationary outdoor O3 measurements from a continuous UV photometer and from 12-hr Harvard active monitors, and time-activity information. Results showed that personal O3 exposure levels averaged one-fourth of outdoor stationary O3 levels, attributable to high percentages of time spent indoors. Personal O3 levels were not predicted well by outdoor measurements. A random-effect general linear model analysis indicated that variance in personal exposure measurements was largely accounted for by random error (59-82%), followed by inter-subject (9-18%) and between-day (9-23%) random effects. The microenvironmental model performs differently by season, with the regression model for spring cohorts exhibiting two times the R2 of the fall cohorts (R2 = 0.21 vs. 0.09). When distance from the stationary monitoring site, elevation, and traffic are taken into account in the microenvironmental models, the adjusted R2 increased almost twofold for the fall personal exposure data. The low predictive power is due primarily to the apparent spatial variation of outdoor O3 and errors in O3 measurements and in time-activity records (particularly in recording the use of air conditioning). This study highlights the magnitude of O3 exposure misclassification in epidemiological settings and proposes an approach to reduce exposure uncertainties in assessing air pollution health effects.

Symptoms in pediatric asthmatics and air pollution: differences in effects by symptom severity, anti-inflammatory medication use and particulate averaging time.

Experimental research in humans and animals points to the importance of adverse respiratory effects from short-term particle exposures and to the importance of proinflammatory effects of air pollutants, particularly O(subscript)3. However, particle averaging time has not been subjected to direct scientific evaluation, and there is a lack of epidemiological research examining both this issue and whether modification of air pollutant effects occurs with differences in asthma severity and anti-inflammatory medication use. The present study examined the relationship of adverse asthma symptoms (bothersome or interfered with daily activities or sleep) to O(3) and particles (less than or equal to)10 micrometer (PM10) in a Southern California community in the air inversion zone (1200-2100 ft) with high O(3) and low PM (R = 0.3). A panel of 25 asthmatics 9-17 years of age were followed daily, August through October 1995 (n = 1,759 person-days excluding one subject without symptoms). Exposures included stationary outdoor hourly PM10 (highest 24-hr mean, 54 microgram/m(3), versus median of 1-hr maximums, 56 microgram/m(3) and O(3) (mean of 1-hr maximums, 90 ppb, 5 days (greater than or equal to)120 ppb). Longitudinal regression analyses utilized the generalized estimating equations (GEE) model controlling for autocorrelation, day of week, outdoor fungi, and weather. Asthma symptoms were significantly associated with both outdoor O(3) and PM(10) in single pollutant- and co-regressions, with 1-hr and 8-hr maximum PM(10) having larger effects than the 24-hr mean. Subgroup analyses showed effects of current day PM(10) maximums were strongest in 10 more frequently symptomatic (MS) children: the odds ratios (ORs) for adverse symptoms from 90th percentile increases were 2.24 [95% confidence interval (CI), 1.46-3.46] for 1-hr PM10 (47 microgram/m(3); 1.82 (CI, 1.18-2.81) for 8-hr PM10 (36 microgram/m(3); and 1.50 (CI, 0.80-2.80) for 24-hr PM10 (25 microgram/m(3). Subgroup analyses also showed the effect of current day O(subscript)3 was strongest in 14 less frequently symptomatic (LS) children: the ORs were 2.15 (CI, 1.04-4.44) for 1-hr O(3) (58 ppb) and 1.92 (CI, 0.97-3.80) for 8-hr O(3) (46 ppb). Effects of 24-hr PM10 were seen in both groups, particularly with 5-day moving averages (ORs were 1.95 for MS and 4. 03 for LS; p(less than or equal to)0.05). The largest effects were in 7 LS children not on anti-inflammatory medications [5-day, 8-hr PM10, 9.66 (CI, 2.80-33.21); current day, 1-hr O(3), 4.14 (CI, 1.71-11.85)]. Results suggest that examination of short-term particle excursions, medication use, and symptom severity in longitudinal studies of asthma yields sensitive measures of adverse respiratory effects of air pollution.

The effect of outdoor fungal spore concentrations on daily asthma severity.

The relationship between day-to-day changes in asthma severity and combined exposures to community air pollutants and aeroallergens remains to be clearly defined. We examined the effects of outdoor air pollutants, fungi, and pollen on asthma. Twenty-two asthmatics ages 9-46 years were followed for 8 weeks (9 May-3 July 1994) in a semirural Southern California community around the air inversion base elevation (1,200 ft). Daily diary responses included asthma symptom severity (6 levels), morning and evening peak expiratory flow rates (PEFR), and as-needed beta-agonist inhaler use. Exposures included 24-hr outdoor concentrations of fungi, pollen, and particulate matter with a diameter < 10 microns (PM10; maximum = 51 micrograms/m3) and 12-hour day-time personal ozone (O3) measurements (90th percentile = 38 ppb). Random effects longitudinal regression models controlled for autocorrelation and weather. Higher temperatures were strongly protective, probably due to air conditioning use and diminished indoor allergens during hot, dry periods. Controlling for weather, total fungal spore concentrations were associated with all outcomes: per minimum to 90th percentile increase of nearly 4,000 spores/m3, asthma symptom scores increased 0.36 (95% CI, 0.16-0.56), inhaler use increased 0.33 puffs (95% CI, -0.02-0.69), and evening PEFR decreased 12.1 l/min (95% CI, -1.8-22.3). These associations were greatly enhanced by examining certain fungal types (e.g., Alternaria, basidiospores, and hyphal fragments) and stratifying on 16 asthmatics allergic to tested deuteromycete fungi. There were no significant associations to low levels of pollen or O3, but inhaler use was associated with PM10 (0.15 inhaler puffs/10 micrograms/m3; p < 0.02). These findings suggest that exposure to fungal spores can adversely effect the daily respiratory status of some asthmatics.

Demographic differences in prostate cancer incidence and stage: an examination of population diversity in California.

INTRODUCTION: Geographic and racial/ethnic variability in prostate cancer incidence rates and stage distribution may be partly attributed to differences in screening and early detection. METHODS: Using California Cancer Registry data we aimed to characterize variability in prostate cancer rates statewide and to examine differences in the stage at diagnosis of prostate cancer by racial/ethnic group statewide and by census tract per capita income in San Diego County. We calculated annual average (1988-1991) age-adjusted incidence rates per 100,000 (AAIR) of prostate cancer for 49,880 men over age 34 years. Racial/ethnic groups were compared using incidence rate ratios (IRR) (AAIR localized plus regional stages divided by AAIR distant stage). RESULTS: Statewide, Caucasians showed a higher IRR [6.16, 95% confidence interval (CI), 6.00-6.30] than did African Americans (2.34, 95% CI, 1.89-2.89), Hispanics (3.84, 95% CI, 3.63-4.05), or Asian/others (3.61, 95% CI, 1.80-7.22). Within San Diego County, Caucasians living in higher per capita income census tracts (> or = 65th percentile) had a significantly higher IRR (8.80, 95% CI 7.84-9.89) than did lower-income tracts (5.68, 95% CI, 5.13-6.30). CONCLUSION: Findings from the present and similar studies suggest that outcomes research is needed to determine the impact of these demographic differences on prostate cancer mortality and quality of life. This is particularly important given the current controversy regarding the treatment of clinically localized prostate cancers, increasingly found through early detection, which often involve difficult choices between aggressive therapies including prostatectomy or watchful waiting.

Cancer risk among Scandinavian immigrants in the US and Scandinavian residents compared with US whites, 1973-89.

Studies of migrants can generate hypotheses on the aetiology of cancer. Such studies are most informative when cancer incidence data are available both in the source and host country. We compared the incidence rate ratio of cancers (stomach, lung, female breast, colorectal and prostate) in Scandinavian immigrants to the US to US-born whites, using data from the SEER registry, 1973-89. Odds ratios (OR) for cancer sites in relation to birthplace were estimated using logistic regression. We also compared rate ratios (RR) for Scandinavian and US residents, using Poisson regression. Compared with US whites, most Scandinavian migrant groups had elevated OR for stomach cancer (1.58 to 3.92), and lower OR for lung cancer (0.38 to 0.88). Similarly, compared with US whites, residents of most Scandinavian countries had elevated RR for stomach cancer (1.47 to 3.33) and lower RR for lung cancer (0.27 to 0.97). Therefore, risk factors for lung and stomach cancers, such as smoking habits and Helicobacter pylori infection, respectively, may have been retained upon migration. Risks for breast, colorectal and prostate cancer among immigrants approached risks in the US (contrasting Scandinavian risks) suggesting assimilation of environmental and/or lifestyle factors.

Smoking and moods in adolescents with depressive and aggressive dispositions: evidence from surveys and electronic diaries.

Surveys and electronic diaries were used to examine depressive and extemalizing dispositions as they relate to smoking and moods in 170 early adolescents. Negative moods were prevalent, with anger and anxiety reported on 26%-60% and sadness on 16%-40% of occasions. The risk of smoking, urges to smoke, and alcohol intake were elevated in teens with aggressive and depressive dispositions, as were diary reports of feeling hassled, angry, and sad. Girls high in depression and aggression also reported more anxiety, stress, and fatigue and less happiness and well-being than did their peers. For boys, depression seemed to dampen the elevated smoking risks associated with externalizing behaviors. Discussion focuses on gender differences in personality-smoking linkages, adolescent negative affectivity, the unique contributions of survey and diary methods, and the promise of targeted preventive interventions such as affect regulation training.

The relationship of ventricular drainage to aneurysmal rebleeding.

Given the widespread use of continuous external ventricular drainage in patients with aneurysmal subarachnoid hemorrhage (SAH), this investigation was undertaken to define the relationship of ventricular drainage to aneurysmal rebleeding. A historical cohort study of 128 patients with confirmed aneurysmal SAH was performed using a multivariate stepwise logistic regression analysis to examine the relationship between aneurysmal rerupture and ventricular drainage, while controlling for important clinical and radiological independent variables. The variables for ventricular drainage selected in the regression analysis were clinical grade, aneurysm size, and presence of hydrocephalus. The rate of rerupture was significantly higher in cases with ventricular drainage (odds ratio 5.31:1, p less than 0.05), poor clinical grade (odds ratio 4.90:1, p less than 0.02), and large aneurysm size (odds ratio 11.25:1, p less than 0.01). The significant effect of ventricular drainage was limited to patients with hydrocephalus. The increased risk of aneurysmal rebleeding in patients undergoing ventricular drainage may result from both: 1) a rise in aneurysmal transmural pressure, since intracranial pressure is lowered by ventricular drainage; and 2) an association between ventricular drainage and a more severely disrupted aneurysm which is more prone to rebleed as part of its natural history. This study found an increased risk of aneurysmal rebleeding among patients undergoing ventricular drainage, particularly in the presence of hydrocephalus.

Evaluation of a real-time passive personal particle monitor in fixed site residential indoor and ambient measurements.

Recent experimental findings in animals and humans indicate adverse respiratory effects from short-term exposures to particulate air pollutants, especially in sensitive subpopulations such as asthmatics. The relationship between air pollution and asthma has mainly been determined using particulate matter (PM) measurements from central sites. Validated tools are needed to assess exposures most relevant to health effects. Recently, a personal passive particulate sampler (personal Data-RAM, pDR, MIE Inc., Bedford, MA) has become available for studying personal exposures to PM with time resolution at 1 min. The pDR measures light scatter from PM in the 0.1-10 microM range, the significant range for health effects. In order to assess the ability of the pDR in predicting gravimetric mass, pDRs were collocated with PM2.5 and PM10 Harvard Impactors (HI) inside and outside nine homes of asthmatic children and at an outdoor central Air Pollution Control District site. Results are presented of comparisons between the HI samplers and the pDR in various modes of operation: passive, active, and active with a heated inlet. When used outdoors at fixed sites the pDR readings exhibit interference from high relative humidity (RH) unless operated with a method for drying inlet air such as a heater, or if readings at times of high RH are adjusted. The pDR correlates more highly with the HI PM2.5 than with the HI PM10 (r2 = 0.66 vs. 0.13 for outdoors, r2 = 0.42 vs. 0.20 for indoors). The pDR appears to be a useful tool for an epidemiologic study that aims to examine the relationship between health outcomes and personal exposure to peaks in PM.

Subacute left ventricular free wall rupture complicating acute myocardial infarction. Successful surgical repair with a sutureless technique.

The high mortality index related to surgical therapy with direct suture of rupture of left ventricular free wall following acute myocardial infarction, suggested we analyze and use alternative techniques. So we applied sutureless technique described by Padro to two patients. We used a Teflon patch fixed to the ventricular wall with a biocompatible synthetic glue, an ethyl-2-cyanoacrylate monomer, without any direct suturing of the infarcted myocardium. The two patients survived the operation and were discharged from the hospital 12 and 14 days after surgery. The sutureless technique allows, in our opinion, a more confident and safe aggressive attitude to subacute left ventricular free wall rupture.

Reliability of hospital data for population-based studies of air pollution.

The use of hospital databases for research into the respiratory effects of air pollution has been questioned. In an attempt to address that issue, reabstracts of 1,279 discharge records from 14 Montreal hospitals were compared with the universal health insurance database of Quebec. Agreement levels on discharge diagnoses were 94.9% for asthma; 75.5% for all other respiratory diagnoses combined, including upper airway infections, pneumonia, and coronary obstructive pulmonary disease (COPD) (90% after ignoring disagreements between closely related respiratory diagnoses); and 93.1% for a nonrespiratory comparison group. Factors associated with misclassification included use of nonurgent admissions; delays in hospital admission from emergency rooms; and differences in levels of diagnostic agreement between hospitals, age groups, and outcome groups. These should be taken into account in air pollution epidemiologic research in which databases of the kind commonly maintained in North American health care systems are used.