Carbon monoxide and stroke: A time series study of ambient air pollution and emergency hospitalizations

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Air pollution and mortality: Effect modification by personal characteristics and specific cause of death in a case-only study

Short-term effects of air pollution on mortality have been well documented in the literature worldwide. Less is known about which subpopulations are more vulnerable to air pollution. We conducted a case-only study in Hong Kong to examine the potential effect modification by personal characteristics and specific causes of death. Individual information of 402,184 deaths of non-external causes and daily mean concentrations of air pollution were collected from 2001 to 2011. For a 10 μg/m3 increase of pollution concentration, people aged ≥∇65 years (compared with younger ages) had a 0.9–1.8% additional increase in mortality related to PM, NO2, and SO2. People dying from cardiorespiratory diseases (compared with other non-external causes) had a 1.6–2.3% additional increase in PM and NO2 related mortality. Other subgroups that were particularly susceptible were females and those economically inactive. Lower socioeconomic status and causes of cardiorespiratory diseases would increase the likelihood of death associated with air pollution.postprin

Ambient carbon monoxide and the risk of hospitalization due to chronic obstructive pulmonary disease

Data from recent experimental and clinical studies have indicated that lower concentrations of inhaled carbon monoxide might have beneficial antiinflammatory effects. Inhaled carbon monoxide has the potential to be a therapeutic agent for chronic obstructive pulmonary diseases (COPD). However, population-based epidemiologic studies of environmentally relevant carbon monoxide exposure have generated mixed findings. We conducted a time-series study in Hong Kong to estimate the association of short-term exposure to ambient carbon monoxide with emergency hospitalizations for COPD. We collected daily emergency hospital admission data and air pollution data from January 2001 to December 2007. We used log-linear Poisson models to estimate the associations between daily hospital admissions for COPD and the average daily concentrations of carbon monoxide while controlling for the traffic-related copollutants nitrogen dioxide and particulate matter with an aerodynamic diameter less than 2.5 μm. Results showed that ambient carbon monoxide was negatively associated with the risk of hospitalizations for COPD. After adjustment for levels nitrogen dioxide or particulate matter with an aerodynamic diameter less than 2.5 μm, the negative associations of carbon monoxide with COPD hospitalizations became stronger. The risk estimates were similar for female and male subjects. In conclusion, short-term exposure to ambient carbon monoxide was associated with a decreased risk of hospitalization for COPD, which suggests that carbon monoxide exposure provides some acute protection of against exacerbation of COPD.postprin

Night-sky brightness monitoring in Hong Kong - a city-wide light pollution assessment

Results of the first comprehensive light pollution survey in Hong Kong are presented. The night-sky brightness was measured and monitored around the city using a portable light sensing device called the Sky Quality Meter over a 15-month period beginning in March 2008. A total of 1,957 data sets were taken at 199 distinct locations, including urban and rural sites covering all 18 Administrative Districts of Hong Kong. The survey shows that the environmental light pollution problem in Hong Kong is severe - the urban night-skies (sky brightness at 15.0 mag per arcsec square) are on average ~100 times brighter than at the darkest rural sites (20.1 mag per arcsec square), indicating that the high lighting densities in the densely populated residential and commercial areas lead to light pollution. In the worst polluted urban location studied, the night-sky at 13.2 mag per arcsec square can be over 500 times brighter than the darkest sites in Hong Kong. The observed night-sky brightness is found to be affected by human factors such as land utilization and population density of the observation sites, together with meteorological and/or environmental factors. Moreover, earlier night-skies (at 9:30pm local time) are generally brighter than later time (at 11:30pm), which can be attributed to some public and commercial lightings being turned off later at night. On the other hand, no concrete relationship between the observed sky brightness and air pollutant concentrations could be established with the limited survey sampling. Results from this survey will serve as an important database for the public to assess whether new rules and regulations are necessary to control the use of outdoor lightings in Hong Kong.Comment: 33 pages, 13 figures, Environmental Monitoring and Assessment, in pres

Age-Related Changes of Myelin Basic Protein in Mouse and Human Auditory Nerve

Age-related hearing loss (presbyacusis) is the most common type of hearing impairment. One of the most consistent pathological changes seen in presbyacusis is the loss of spiral ganglion neurons (SGNs). Defining the cellular and molecular basis of SGN degeneration in the human inner ear is critical to gaining a better understanding of the pathophysiology of presbyacusis. However, information on age-related cellular and molecular alterations in the human spiral ganglion remains scant, owing to the very limited availably of human specimens suitable for high resolution morphological and molecular analysis. This study aimed at defining age-related alterations in the auditory nerve in human temporal bones and determining if immunostaining for myelin basic protein (MBP) can be used as an alternative approach to electron microscopy for evaluating myelin degeneration. For comparative purposes, we evaluated ultrastructural alternations and changes in MBP immunostaining in aging CBA/CaJ mice. We then examined 13 temporal bones from 10 human donors, including 4 adults aged 38–46 years (middle-aged group) and 6 adults aged 63–91 years (older group). Similar to the mouse, intense immunostaining of MBP was present throughout the auditory nerve of the middle-aged human donors. Significant declines in MBP immunoreactivity and losses of MBP+ auditory nerve fibers were observed in the spiral ganglia of both the older human and aged mouse ears. This study demonstrates that immunostaining for MBP in combination with confocal microscopy provides a sensitive, reliable, and efficient method for assessing alterations of myelin sheaths in the auditory nerve. The results also suggest that myelin degeneration may play a critical role in the SGN loss and the subsequent decline of the auditory nerve function in presbyacusis

Mild postnatal anemia: Is it a problem?

Mild postnatal anemia is common. However, determination of postnatal hemoglobin level or iron supplementation are not routine in many obstetric units. This study was designed to evaluate the impact of mild postnatal anemia and iron supplementation on women. One hundred fifty women who had postnatal hemoglobin levels between 80 and 99 g/L were randomly assigned into two groups with iron tablets or placebo provided from the time of diagnosis until reassessment at 6 weeks. The patients' general well-being, hemoglobin levels, iron status, side effects, and compliance were assessed. One hundred twenty-two women returned for reassessment. Twelve (9.8%) of the 122 women recruited and four (3.2%) of 122 nonanemic matched controls complained of dizziness 2 days after delivery; the difference was statistically significant (χ 2 test, p < 0.05). At 6 weeks postpartum, significantly more women were anemic (χ 2 test, p < 0.05) and iron deficient (χ 2 test, p < 0.01) in the placebo group. The score of general well-being as assessed by a 4-point scale was significantly higher in the iron supplementation group (Mann-Whitney test, p < 0.05). The amounts of drugs consumed in both groups were comparable and the incidences of side effects were similar. Copyright © 2005 by Thieme Medical Publishers, Inc.link_to_subscribed_fulltex

A retrospective review on atypical glandular cells of undetermined significance (AGUS) using the Bethesda 2001 classification

Objectives The Bethesda system for reporting cervicovaginal cytologic diagnoses was recently revised in 2001. Pathologists are required to report not only whether the smear favors neoplastic changes, but also the origin of the abnormal cells. In this study, archival smears were reviewed to evaluate the usefulness of the new classification. Methods Smears having atypical glandular cells taken between January 1995 and December 1997 were reviewed and subclassified according to the revised Bethesda classification. Case records were then reviewed and cases with discrepancies between the cytological evaluation and corresponding final histological diagnoses were further reviewed. Results There were 138 smears reviewed. The mean age of the patients was 47 (range, 18 to 78). Thirty-four smears favored neoplasia and 104 favored "NOS" ("not otherwise specified"). Sixty smears favored endocervical origin and 78 endometrial origin. Forty-three patients (31%) had significant pathologies, including 12 (8.7%) patients with high-grade CIN, 2 (1.4%) with low-grade CIN, 5 (3.6%) with HPV infection, 7 (5.1%) with carcinoma of the corpus, 1 (0.7%) with cervical adenocarcinoma in situ, 4 (2.9%) with adenocarcinoma of the cervix, 3 (2.2%) with endometrial hyperplasia, and 5 (3.6%) with carcinoma of the ovary. Two (1.4%) patients had double primary female genital malignancies and 2 patients (1.4%) had extragenital malignancies. Significant correlation was found between smears "favor neoplasia" and a final diagnosis with significant pathology (χ 2 test, P < 0.05). Significant association was found between AGC favored endocervical origin and a final diagnosis with cervical diseases (χ 2 test, P < 0.05). Four of the 43 patients who had significant pathologies had lesions found during their subsequent visits and all of them had cervical smears classified as AGC "favor neoplasia". Conclusions AGC found on cervical smears are an indication for early and intensive investigation. © 2003 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex