Role of late amniocentesis in the era of modern genomic technologies.

OBJECTIVE: Traditionally, amniocentesis is performed between 17 and 23 weeks of gestation. This enables decisions regarding the course of pregnancy to be made before viability. Less frequently, amniocentesis is performed in the third trimester. Advanced genomic technologies such as chromosomal microarray analysis (CMA) provide more detailed information about the fetus compared with traditional G-banded chromosomal analysis. The aim of this study was to assess the indications for and safety of late amniocentesis, genetic-test results (especially in the context of CMA technology) and outcome of pregnancies that underwent the procedure after 24 weeks. METHODS: Medical records were analyzed retrospectively of all women in whom amniocentesis was performed at a gestational age of 24 + 0 to 38 + 6 weeks, at Hadassah Medical Center, between June 2013 and March 2017. Parameters investigated included indications for late amniocentesis, complications, CMA results and pregnancy outcome. RESULTS: During the study period, 291 women (303 fetuses, 277 singleton and 14 twin pregnancies; in two twin pairs, one fetus was terminated before amniocentesis) underwent late amniocentesis. CMA was performed in all instances of amniocentesis. The most frequent indication was abnormal sonographic finding(s) (204/303 fetuses, 67%). Preterm delivery occurred in 1.7% and 5.1% of pregnancies within the first week and within 1 month following the procedure, respectively. Aneuploidy was detected in nine (3%) fetuses and nine (3%) others had a pathogenic/likely pathogenic copy number variant, suggesting that CMA doubled the diagnostic yield of traditional karyotyping. Maximal diagnostic yield (17.5%) was achieved for the subgroup of fetuses referred with abnormal sonographic findings in two or more fetal anatomical systems. Variants of uncertain significance or susceptibility loci were found in another nine (3%) fetuses. CONCLUSIONS: In pregnancies undergoing late amniocentesis, CMA increased detection rates of fetal abnormalities and had a shorter turnaround time compared with traditional chromosomal analysis; therefore, late amniocentesis may serve as a helpful tool for detecting fetal abnormalities or reassuring parents following late-appearing abnormal sonographic findings. However, CMA may expose findings of uncertain significance, about which the couple should be precounseled. The procedure appears to be safe. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Randomized Trial of Motivational Interviewing to Prevent Early Childhood Caries in Public Housing.

INTRODUCTION: Caries experience among preschool-age children has remained relatively unchanged for the past 2 decades, despite recently documented decreases in untreated decay. OBJECTIVES: In a community-based cluster-randomized controlled trial, a motivational interviewing (MI) intervention administered to primary caregivers was hypothesized to reduce caries increment over 2 y as compared with controls, among children aged 0 to 5 y at baseline living in public housing. METHODS: Public housing residents, who served as interventionists, were trained in MI with a focus on early childhood caries prevention. All 26 eligible public housing developments were randomized to either control (quarterly clinical examinations, fluoride varnish applications, toothbrush/toothpaste, and educational brochures) or intervention (same procedures as control plus MI counseling). Quarterly MI sessions were delivered in English or Spanish over 2 y, audio recorded, and assessed for treatment fidelity. The primary outcome was the increment in dmfs (decayed, missing, and filled tooth surfaces) as assessed by clinical examination at baseline, 12 mo, and 24 mo. Secondary outcomes included caregiver oral health knowledge and child oral health behaviors (child toothbrushing and sugar-sweetened beverage intake). Baseline characteristics were compared between groups and adjusted for housing-site clusters. Longitudinal outcomes were analyzed with mixed models. RESULTS: A total of 1,065 children (49% female, 55% non-White, 61% Hispanic, 89% below poverty level, n = 686 control) and their caregivers were enrolled. During 2 y of follow-up, the mean dmfs increment increased in both groups; however, there were no statistically significant group differences at 24 mo or group × time interactions. The mean increase in intervention caregivers' knowledge was significantly greater than that of control, F(2, 1,593) = 3.48, P = 0.0310, but there were no significant intervention effects on caregiver-reported child sugar-sweetened beverage intake or child toothbrushing. CONCLUSION: MI counseling plus intensive caries prevention activities resulted in knowledge increases but did not improve oral health behaviors or caries increment (ClinicalTrials.gov NCT01205971). KNOWLEDGE TRANSFER STATEMENT: When viewed in light of the findings from the companion Pine Ridge study and other recent MI studies, the results of this study suggest that when the complex disease of early childhood caries is addressed in high-risk populations, MI is not effective, and alternative approaches are warranted.

Validation of the driver behaviour questionnaire using behavioural data from an instrumented vehicle and high-fidelity driving simulator.

Data from two previously published studies were used to examine the correlations between scores on the violation, error and lapse sub-scales of the driver behaviour questionnaire, and observed driving speed. One dataset utilised data from an instrumented vehicle, which recorded driver speed on bends on a rural road. The other utilised data from a driving simulator study. Generally in both datasets the DBQ violation subscale was associated with objectively-measured speed, while the error and lapse sub-scales were not. These findings are consistent with the idea that the DBQ is a valid measure of observed behaviour in real driving (its original intended use) and also in simulated driving. The fact that associations were the same in real and simulated driving lends further support to the relative validity of driving simulation. The need for larger and more focused studies examining the role of different motivations in different driving situations is discussed.

Evidence for the long term cost effectiveness of home care reablement programs.

BACKGROUND: The objectives of this study were to determine whether older individuals who participated in a reablement (restorative) program rather than immediately receiving conventional home care services had a reduced need for ongoing support and lower home care costs over the next 57 months (nearly 5 years). MATERIALS AND METHODS: Data linkage was used to examine retrospectively the service records of older individuals who had received a reablement service versus a conventional home care service to ascertain their use of home care services over time. RESULTS: Individuals who had received a reablement service were less likely to use a personal care service throughout the follow-up period or any other type of home care over the next 3 years. This reduced use of home care services was associated with median cost savings per person of approximately AU $12,500 over nearly 5 years. CONCLUSION: The inclusion of reablement as the starting point for individuals referred for home care within Australia's reformed aged care system could increase the system's cost effectiveness and ensure that all older Australians have the opportunity to maximize their independence as they age.

Changes in self-reported driving intentions and attitudes while learning to drive in Great Britain.

Novice drivers are overrepresented in traffic collisions, especially in their first year of solo driving. It is widely accepted that some driving behaviours (such as speeding and thrill-seeking) increase risk in this group. Increasingly research is suggesting that attitudes and behavioural intentions held in the pre-driver and learning stage are important in determining later driver behaviour in solo driving. In this study we examine changes in several self-reported attitudes and behavioural intentions across the learning stage in a sample of learner drivers in Great Britain. A sample of 204 learner drivers completed a self-report questionnaire near the beginning of their learning, and then again shortly after they passed their practical driving test. Results showed that self-reported intentions regarding speed choice, perceptions regarding skill level, and intentions regarding thrill-seeking (through driving) became less safe over this time period, while self-reported intentions regarding following distance and overtaking tendency became safer. The results are discussed with reference to models of driver behaviour that focus on task difficulty; it is suggested that the manner in which behind-the-wheel experience relates to the risk measures of interest may be the key determining factor in how these change over the course of learning to drive.

Judgments of approach speed for motorcycles across different lighting levels and the effect of an improved tri-headlight configuration.

The misperception of vehicle approach speed is a key contributory factor to road traffic crash involvement. Past research has indicated that individuals use the rate of visual looming to calculate the time to passage (TTP) of a vehicle, and that smaller vehicles loom to a lesser extent than larger vehicles. Despite a disproportionate number of fatal injuries occurring on the road after dark, and a higher than average number of accidents involving automobile drivers violating the right of way of a motorcyclist occurring in low light conditions, there has been very little consideration of the accuracy of TTP for smaller and larger vehicles under low levels of luminance. We investigated drivers' judgments of motorcycle and car approach speeds across a number of levels of luminance within a virtual city scene, as well as the effectiveness of a tri-headlight formation on motorcycle speed judgments. The accuracy of car approach speed judgments were not affected by changes in lighting conditions, but speed judgments for the solo headlight motorcycle became significantly less accurate as lighting reduced in the early night and night-time conditions. Incorporation of a tri-headlight formation onto the standard motorcycle frame resulted in improved accuracy of approach speed judgments, relative to the solo headlight motorcycle, as ambient light levels reduced. The practical implications of the findings are discussed in terms of road safety and motorcycle design.

Errors in judging the approach rate of motorcycles in nighttime conditions and the effect of an improved lighting configuration.

One of the key contributory factors for accident involvement is misjudgment of approach speed (Department for Transport, 2010). Past research has indicated that individuals can use the rate of visual looming in order to the judge time to passage (TTP) of approaching vehicles, and that smaller vehicles loom to a lesser extent than larger vehicles (e.g., Horswill et al., 2005). However, the judgment of TTP in nighttime conditions has received little attention. This paper explores drivers' abilities to make judgments of motorcycles and car approach speeds in nighttime driving conditions, when only the headlights are visible, as well as the effectiveness of a tri-headlight configuration on the accuracy of motorcycle speed judgments. Results showed that individuals were significantly more accurate at judging the speed of two car headlights compared with the standard solo headlight motorcycle. However, the inclusion of a tri-headlight formation on a standard motorcycle frame significantly improved these judgments. A further investigation demonstrated that tri-headlight configurations with separation between headlights on the horizontal and vertical axes are most effective for yielding accurate speed judgments. The implications of the results for road safety and motorcycle design are discussed.

[Effect of the populations of Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) on cotton crop at two sowing distances]. / Efecto de las poblaciones de Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) en cultivos de algodón a dos distanciamientos.

The objective of this research was to evaluate the incidence of damage by the leafworm Alabama argillacea (Hübner) on yields of cotton grown under rows spaced 0.38 m and 0.76 m at the irrigation area of Santiago del Estero, Argentina. The period evaluated was extended from first flower to first open boll. Treatments were T1 - without control of larvae, T2 - with control of larvae, T3 - control since first flower to the end of effective blooming, and T4 - with larval control since the end of effective blooming to first open boll. The effect of injuries on the crop was evaluated trough boll cotton yield. Larvae were sampled in a weekly basis and insects were present from the first flower until harvest. Populations of A. argillacea decreased crop yields in the two distances tested, by decreasing the weight or number of open bolls.

A comparison of coronary heart disease event rates among urban Australian Aboriginal people and a matched non-Aboriginal population.

BACKGROUND: Age-specific death from cardiovascular disease among Australian Aboriginals is estimated to be four to seven times that of general population, and the major cause of premature death. There is little reliable information on the incidence of coronary heart disease (CHD). This study compares CHD event rates in urban-dwelling Aboriginal people and the general population. METHODS: The Perth Aboriginal Atherosclerosis Risk Study (PAARS) cohort was assessed at baseline (1998/1999) and 913 participants followed-up to 2006. A comparison group of age-matched, sex-matched and postcode-matched non-Aboriginals (n=3582) were selected from the Perth, Western Australia, Electoral Roll. Electronic record linkage captured prior CHD and first CHD events in both groups. The rates of first CHD events (hospital admission or CHD death) per 1000 person years (PY) and incidence rate ratios (IRR) were calculated. RESULTS: The event rate for the PAARS population was 14.9 per 1000 PY (95% CI 12.3 to 18.2) versus 2.4 (1.9 to 3.1) for the general population. The IRR was 6.1 (4.5 to 8.4). For Aboriginal men the rate was 15.0 (11.2 to 20.0) versus 3.8 (2.5 to 5.0) per 1000 PY, with age-specific rates being two to five times that of non-Aboriginals. Incidence for Aboriginal women was 15.0 (11.5 to 19.5) versus 1.4 (0.9 to 2.1) with age-specific rates being 8-25 times that of non-Aboriginals. CONCLUSIONS: Age and sex-specific CHD event rates in urban Aboriginals far exceeded that of a matched general population. Events occurred at a much younger age among the Aboriginal participants and were equally excessive among men and women.

Retinol supplementation and mesothelioma incidence in workers earlier exposed to blue asbestos (Crocidolite) at Wittenoom, Western Australia.

Owing to the high rates of malignant mesothelioma in workers exposed to crocidolite earlier at Wittenoom and evidence of protection against cancer by vitamin A, a population-based cancer prevention programme providing retinol supplements (25 000 IU/day) was commenced in 1990. The former workers at Wittenoom known to be alive and living in Western Australia in June 1990 constitute the study population. The participants were classified into two groups: those who received supplemental retinol (intervention group) and those who received none (comparison group). The relative rate of mesothelioma for those receiving retinol was estimated using Cox regression, adjusting for cumulative asbestos exposure and age at first exposure to asbestos. Nine hundred and twenty-eight former Wittenoom workers received retinol at some stage of the programme, whereas 1471 workers never received retinol (comparison group). Those who received retinol were younger, had a greater exposure to asbestos and smoked less than the comparison group. There were 65 cases of mesothelioma in the retinol group and 88 in the comparison group. After adjustment, the hazard ratio was 0.99 (95% confidence interval=0.70-1.41). This result did not alter when the participants who received only retinol once or those who received beta-carotene earlier were excluded from the analysis. In conclusion, this study provides little support for possible preventive effects of retinol against mesothelioma in workers exposed to blue asbestos.

The use of coronary revascularisation procedures in urban Australian Aboriginals and a matched general population coronary procedures in Aboriginals.

BACKGROUND: Coronary revascularisation procedures may be under-used for Aboriginal Australians with ischaemic heart disease (IHD). We compared the use of procedures in an urban Aboriginal population and a non-Aboriginal external comparison group. METHODS: The Perth Aboriginal Atherosclerosis Risk (PAARS) cohort (n=998) and 3695 age- and sex-matched non-Aboriginals were electronically linked to Western Australian hospital morbidity data to identify admissions and revascularisation procedures between 1980 and 2006. RESULTS: There were 731 admissions for IHD for 983 PAARS participants with hospital admissions and 391 in 3150 non-Aboriginals. There were 136 first procedures overall; 43% of Aboriginals having a procedure were women versus 18.5% of non-Aboriginals. 41% of Aboriginal patients and 48% of non-Aboriginals had procedures (p=0.12). Aboriginals were more likely to have coronary artery bypass grafts (CABG) (40.5%) than a percutaneous coronary intervention (PCI), compared to the general population (23%, p=0.02). The proportion of first procedures for acute coronary syndrome (ACS) admissions was 61% for both groups, 80% and 85%, respectively, being PCI. CONCLUSIONS: Coronary revascularisation procedures for IHD were used with equal frequency in Aboriginal people and matched non-Aboriginals. Aboriginal people were more likely to have CABG than PCI. Revascularisation rate and type in ACS admissions were the same.

Measuring the gap: accuracy of the Western Australian hospital morbidity data in the identification of adult urban Aboriginal and Torres Strait Islander people.

OBJECTIVE: To assess the sensitivity of the recording of Aboriginality in the Western Australia Linked Data. METHODS: This was a follow-up study using record linkage. Demographic data was obtained from 993 adult, urban-dwelling Aboriginal Australian participants in the Perth Aboriginal Atherosclerosis Risk study (PAARS). These were linked to the Western Australian Linked Data (State-wide hospital admissions and discharges, and deaths) to provide the number of admissions and Indigenous status coding from 1980 to 2006. RESULTS: There were 14,413 admissions for PAARS participants in the study period. The sensitivity of coding of Indigenous status in hospital admissions data significantly improved over time, exceeding 0.9 in every year since 2002. Prior to 2002 sensitivity was around 0.8, but poorer for males, with some anomalous years. CONCLUSIONS: The coding of Indigenous status in the Western Australia Hospital Morbidity Database since 2002 has improved. The data from earlier decades must be approached with more caution. IMPLICATIONS: The improved accuracy of identification of Indigenous status in the Western Australia Hospital Morbidity Database allows comparative studies of adult Aboriginal and non-Aboriginal population health outcomes to be undertaken with confidence.

Coronary heart disease events in Aboriginal Australians: incidence in an urban population.

OBJECTIVE: To determine the incidence of coronary heart disease (CHD) events in an urban Aboriginal population. DESIGN, SETTING AND PARTICIPANTS: Cohort study of 906 Aboriginal people without CHD from 998 who had undergone risk-factor assessment in the Perth Aboriginal Atherosclerosis Risk Study (PAARS) in 1998-1999. PAARS cohort data were electronically linked to a range of databases that included Western Australian hospital morbidity data and death registry data. We analysed data from January 1980 to December 2006 to identify previous admissions for CHD from 1980 to baseline (1998-1999) and new events from baseline to 2006. MAIN OUTCOME MEASURE: First CHD event (hospital admission or death). RESULTS: There were 891 linked records for the 906 participants without previous CHD. The event rate was 12.6/1000 person-years (95% CI, 10.2-15.6/1000 person-years). Annual CHD event rates ranged from 8 to 18/1000 person-years. After adjustment for age (sex was not associated with the risk factors assessed), factors associated with risk of a CHD event in the PAARS cohort were a history of diabetes, overweight or obesity (indicated by body mass index), smoking, and hypertension, but not waist circumference. People with these risk factors were 1.9-2.7 times more likely to experience a CHD event. Compared with previously published information from a remote Aboriginal community in the Northern Territory, the incidence of CHD events among urban-dwelling Aboriginal people was not significantly different (P > 0.05 overall and for subgroups defined by age and sex). CONCLUSIONS: City-dwelling Aboriginal Australians have an incidence of CHD events comparable to that of Aboriginal people living in remote northern Australia.

The effect of alcohol intake on breastfeeding duration in Australian women.

AIM: This study investigated the relationships between alcohol consumption and breastfeeding initiation and duration. DESIGN AND SETTING: A 12-month longitudinal study was conducted in two public hospitals in Perth, Australia between September 2002 and July 2003. INTERVENTION: Participating mothers completed a self-administered baseline questionnaire. Follow-up telephone interviews were conducted at 4, 10, 16, 22, 32, 40 and 52 weeks. MAIN OUTCOME MEASURES: Association of the relationships between alcohol consumption and breastfeeding initiation and duration. RESULTS: After 6 months of follow-up, women who consumed alcohol at levels of more than two standard drinks per day were almost twice as likely to discontinue breastfeeding than women who drank below these levels (HR 1.9, 95% CI 1.1, 3.0). CONCLUSION: Consuming alcohol in excess of two standard drinks per day during lactation was found to be independently associated with shorter breastfeeding duration, even after consideration of previously identified predictors of breastfeeding duration. Guidelines that provide direction on safe alcohol consumption for lactating mothers may help support extended breastfeeding duration.

Plasma vitamin concentrations and incidence of mesothelioma and lung cancer in individuals exposed to crocidolite at Wittenoom, Western Australia.

Increased rates of death from asbestos-related diseases have been reported in former workers and residents exposed to crocidolite (blue asbestos) at Wittenoom (Western Australia). The relationships between plasma concentrations of retinol, carotene and vitamin E and incidence of mesothelioma and lung cancer in a cohort of people from this town were examined. The relationships were evaluated by survival analyses using data obtained at the first visit, at each visit and with the rate of change of each vitamin during the period of follow-up. Of 1953 study participants, 65 developed mesothelioma during the follow-up, and 47 developed lung cancer. A lower incidence of mesothelioma was related to plasma concentrations of retinol at the first visit [hazard ratio (HR)=0.63, 95% confidence interval=0.41-0.99], and to measurements at each visit (HR=0.71, 95% confidence interval=0.50-1.00). Plasma carotene concentrations at the first measurement, but not during the follow-up period, were associated with lower incidence of lung cancer in men and in workers. No significant associations were found between carotene concentrations and incidence of mesothelioma. Vitamin E concentrations were not significantly associated with mesothelioma or lung cancer incidence. These findings suggest that people with chronically low plasma levels of retinol have increased risk of developing mesothelioma and lung cancer.

Which women stop smoking during pregnancy and the effect on breastfeeding duration.

BACKGROUND: Cigarette smoking during pregnancy increases the risk of adverse pregnancy outcomes and women who quit smoking at this time are able to reduce the risk of low birth weight, preterm labour, spontaneous abortion and perinatal death. This study investigates the socio-demographic characteristics of pregnant women who stop smoking during pregnancy and the association between stopping smoking and breastfeeding duration. METHODS: A 12 month longitudinal study was conducted in two public maternity hospitals in Perth, Australia between mid-September 2002 and mid-July 2003. While in hospital, participating mothers completed a self-administered baseline questionnaire. Follow up telephone interviews were conducted at 4, 10, 16, 22, 32, 40 and 52 weeks. RESULTS: A total of 587 (55%) mothers participated in the study. Two hundred and twenty six (39%) mothers reported smoking prior to pregnancy and 77 (34%) of these stopped smoking during pregnancy. Women who were pregnant for the first time were twice as likely (OR = 2.05; 95% CI 1.047 - 4.03; p < 0.05) to quit smoking as multiparous women. Women who smoked more than 10 cigarettes per day were significantly less likely to quit smoking during pregnancy (OR = 0.36; 95% CI 0.18 - 0.69; p < 0.05). Women who consumed alcohol before pregnancy were three times more likely to quit smoking (OR = 2.58; 95% CI 1.00 - 6.66; p < 0.05). Quitting smoking during pregnancy was significantly associated with breastfeeding for longer than six months (OR = 3.70; 95% CI 1.55 - 8.83; p < 0.05). CONCLUSION: Pregnancy is a time when many women are motivated to quit smoking and providing targeted smoking cessation interventions at this time, which take into account factors predictive of quitting smoking, are more likely to be successful.

Effects of asbestos and smoking on gas diffusion in people exposed to crocidolite.

OBJECTIVE: To examine the effects of asbestos exposure and tobacco smoking on the level and rate of change of the diffusing capacity of the lung for carbon monoxide (DLCO). DESIGN AND PARTICIPANTS: A cohort study of 934 people (including both mine workers and town residents) exposed to crocidolite (blue asbestos) at the asbestos mines and in the town of Wittenoom, Western Australia, between 1943 and 1966. DLCO measurements were taken during a follow-up period from 1992 to 2002. MAIN OUTCOME MEASURES: Baseline levels of DLCO and change in levels over time. RESULTS: 2980 DLCO measurements were done on 934 people (of whom 818 were men and 724 were workers) who underwent a median of 2 (range, 1-17) measurements during the follow-up period. Radiographic asbestosis at baseline and asbestos exposure at a younger age were associated with lower DLCO values. The average rate of decline in DLCO was 0.33 (95% CI, 0.31-0.35) units per year, plus an additional decrement of 0.22 (95% CI, 0.12-0.32) units per year if the participant had radiographic asbestosis at the beginning of the follow-up period. Compared with never-smokers, current smokers and ex-smokers had lower DLCO at baseline, but smoking status did not affect the change in DLCO during the follow-up period. CONCLUSIONS: Our results confirm a continuous deleterious effect of crocidolite on DLCO, especially on people with asbestosis. Smoking was associated with lower DLCO levels, but was not a significant predictor of rate of change in DLCO. Smoking status did not affect the relationships between crocidolite exposure and the level or rate of change of DLCO in this population.

Plasma concentrations of retinol, carotene, and vitamin E and mortality in subjects with asbestosis in a cohort exposed to crocidolite in Wittenoom, Western Australia.

OBJECTIVE: We sought to examine the relationships between plasma concentrations of retinol, carotene, and vitamin E and mortality associated with asbestosis in people previously exposed to crocidolite. METHODS: Cox regression modeling was applied to examine these relationships at the first measurement of each vitamin, at the measurement at each visit, and with the rate of change of each vitamin during the follow-up. RESULTS: There were 76 deaths of people with asbestosis during the follow-up period and 1885 subjects censored. Mortality in subjects with asbestosis was inversely related to plasma levels of retinol and Vitamin E concentrations and to their rate of increase during the follow-up. Carotene concentrations at first visit were associated with lower mortality but not during the follow up period. CONCLUSIONS: Chronically low levels of these vitamins are associated with an increased risk of dying with asbestosis.

Plasma retinol, carotene and vitamin E concentrations and lung function in a crocidolite-exposed cohort from Wittenoom, Western Australia: a cohort study.

BACKGROUND: Increased rates of death from asbestos related diseases have been reported for people previously employed in the mining and milling operations at Wittenoom (Western Australia), and people who lived in the nearby town, where they were environmentally exposed to crocidolite. METHODS: Annual measurements of forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) and plasma concentrations of retinol, carotene and vitamin E have been made since 1992. Mixed effects models were used to examine the associations between lung function and the plasma vitamin levels of retinol, carotene and vitamin E. RESULTS: After adjusting for potential confounders, higher plasma retinol and carotene concentrations were significantly associated with higher levels of lung function at entry into the study, while vitamin E concentrations were associated with lower entry lung function. Retinol was associated with a less steep decline of lung function over time, while carotene concentrations were associated with an increased decline of lung function over time and vitamin E levels were not associated with changes of lung function over time. CONCLUSION: These results support a beneficial relationship between plasma concentrations of retinol on the levels and rates of change of lung function, while showing no such consistent beneficial effect for plasma levels of beta-carotene or vitamin E.

PGE(2) activation of apical membrane Cl(-) channels in A6 epithelia: impedance analysis.

Measurements of transepithelial electrical impedance of continuously short-circuited A6 epithelia were made at audio frequencies (0.244 Hz to 10.45 kHz) to investigate the time course and extent to which prostaglandin E(2) (PGE(2)) modulates Cl(-) transport and apical membrane capacitance in this cell-cultured model epithelium. Apical and basolateral membrane resistances were determined by nonlinear curve-fitting of the impedance vectors at relatively low frequencies (<50 Hz) to equations (Paunescu, T. G., and S. I. Helman. 2001. Biophys. J. 81:838--851) where depressed Nyquist impedance semicircles were characteristic of the membrane impedances under control Na(+)-transporting and amiloride-inhibited conditions. In all tissues (control, amiloride-blocked, and amiloride-blocked and furosemide-pretreated), PGE(2) caused relatively small (< approximately 3 microA/cm(2)) and rapid (<60 s) maximal increase of chloride current due to activation of a rather large increase of apical membrane conductance that preceded significant activation of Na(+) transport through amiloride-sensitive epithelial Na(+) channels (ENaCs). Apical membrane capacitance was frequency-dependent with a Cole-Cole dielectric dispersion whose relaxation frequency was near 150 Hz. Analysis of the time-dependent changes of the complex frequency-dependent equivalent capacitance of the cells at frequencies >1.5 kHz revealed that the mean 9.8% increase of capacitance caused by PGE(2) was not correlated in time with activation of chloride conductance, but rather correlated with activation of apical membrane Na(+) transport.