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51.
52.
Wael K. Al-Delaimy Mark G. Myers Eric C. Leas David R. Strong C. Richard Hofstetter 《American journal of public health》2015,105(6):1213-1219
Objectives. We examined whether smokers who used e-cigarettes are more likely to quit after 1 year than smokers who had never used e-cigarettes.Methods. We surveyed California smokers (n = 1000) at 2 time points 1 year apart. We conducted logistic regression analyses to determine whether history of e-cigarette use at baseline predicted quitting behavior at follow-up, adjusting for demographics and smoking behavior at baseline. We limited analyses to smokers who reported consistent e-cigarette behavior at baseline and follow-up.Results. Compared with smokers who never used e-cigarettes, smokers who ever used e-cigarettes were significantly less likely to decrease cigarette consumption (odds ratio [OR] = 0.51; 95% confidence interval [CI] = 0.30, 0.87), and significantly less likely to quit for 30 days or more at follow-up (OR = 0.41; 95% CI = 0.18, 0.93). Ever-users of e-cigarettes were more likely to report a quit attempt, although this was not statistically significant (OR = 1.15; 95% CI = 0.67, 1.97).Conclusions. Smokers who have used e-cigarettes may be at increased risk for not being able to quit smoking. These findings, which need to be confirmed by longer-term cohort studies, have important policy and regulation implications regarding the use of e-cigarettes among smokers.The use of electronic cigarettes (e-cigarettes)—also known as electronic nicotine delivery systems, personal vaporizers, and vaping cigarettes—is a recent and rapidly expanding phenomenon. These names refer to a battery-operated device that electronically heats a liquid (sometime referred to as “e-juice”) containing nicotine and propylene glycol, plus flavors, to create a misty vapor mimicking cigarette smoke that is inhaled by the smoker (who is commonly known as the “vaper”). This increasing use of e-cigarettes has become a controversial issue among health professionals, policymakers, vapers, and the general public. According to the surgeon general’s recent recommendations, e-cigarettes need to be regulated and their use in the population closely monitored, especially given the doubling of use among youths within just 1 year (between 2011 and 2012).1The main controversy surrounding the use of e-cigarettes is whether they are of benefit to smokers, as an alternative to cigarettes and for harm reduction, or whether they cause more harm to society by introducing and propagating new forms of nicotine addiction.2 At present, there is a scarcity of data to help guide decisions regarding the potential harm versus benefits of e-cigarettes, a situation that has led to claims and counterclaims by opponents and proponents of e-cigarette use.3 If smokers quit traditional cigarettes and instead use e-cigarettes to maintain their nicotine addiction (but without the degree of exposure to known carcinogenic byproducts of tobacco combustion), this may be a viable harm reduction strategy that can become a powerful tool for tobacco control.Most of the evidence that users and proponents of e-cigarettes employ have been anecdotal and not scientifically validated; recently, however, more studies on this topic have appeared. One of the first, a pilot study funded by the manufacturers of an e-cigarette brand from Italy, included 40 smokers who were given e-cigarettes and followed up for 24 weeks. The authors reported a 22.5% rate of sustained abstinence from cigarettes among e-cigarette users, a rate comparable to the effects of nicotine replacement therapy in experimental settings.4 However, this study was underpowered because of the small number of participants. A more recent and larger 3-arm trial of e-cigarette use from New Zealand randomized participants to use e-cigarettes (nicotine or placebo) or nicotine patches to quit smoking. Abstinence rates at 6-month follow-up were low across conditions (4.1%–7.8%), with the highest rate found with nicotine e-cigarettes and the lowest with placebo e-cigarettes,5 but no significant differences emerged. In addition to its low statistical power, the study included a potential methodological bias because those in the e-cigarette arm of the trial were mailed the device and cartridges while those in the nicotine patch arm were mailed a voucher (thus requiring that they obtain the nicotine patches). The difference in dose of nicotine and type of e-cigarettes is an additional major limiting factor in interpreting these results across different studies.An earlier study of a convenience sample of 81 ever-users of e-cigarettes concluded that most participants were using them to quit smoking,6 but it provided no clear indication of how successful they were. A larger follow-up survey of e-cigarette users by the same authors indicated that almost all former smokers (96%) agreed that e-cigarettes helped them quit smoking and 57.7% of current smokers believed that e-cigarettes would help them quit or avoid relapsing.7 However, these studies were biased toward self-selected current users without any comparison groups, and the actual influence on quitting among ever-users versus never-users is unknown. More recently, a meta-analysis by Grana et al. found that all 4 prospective studies that assessed the influence of e-cigarette use on quitting behavior found that e-cigarette use did not assist smokers in quitting.8We prospectively assessed how ever using e-cigarettes, compared with never using them, affected abstinence and smoking habits among smokers in the general population. Given that previous data suggest that smokers mostly use e-cigarettes to quit smoking, we hypothesized that smokers in the general population who have tried or who currently use e-cigarettes are more likely to succeed in quitting than smokers who never used them, after controlling for level of addiction, quitting intentions, and smoking behavior. 相似文献
53.
54.
Mei Ling Yap Bok Ai Choo Yiong Huak Chan Jay Jiade Lu Khai Mun Lee Ivan WK Tham 《Journal of Medical Imaging and Radiation Oncology》2012,56(5):548-553
Introduction: Patients with locally advanced nasopharyngeal carcinoma (NPC) commonly present with cranial nerve (CN) involvement, which can cause significant morbidity. We aimed to characterise the pattern of involvement and outcomes of these patients, as well as determine if these differed according to the mode of diagnosis. Methods: Patients were included if they had non‐distant metastatic NPC, presented with CN involvement and completed radiotherapy treatment between 2002 and 2008. The clinical response was categorised as complete response, partial response, stable or progressive disease. The radiological response was assessed using the Response Evaluation Criteria in Solid Tumors criteria. The loco‐regional control and disease‐free survival rates were estimated with the Kaplan–Meier method. Results: Forty‐seven patients fulfilled the inclusion criteria. CN lesions were diagnosed on clinical examination in 15% of patients, radiologically in 40% and both clinically and radiologically in 45% of patients. A complete or partial response of the CN lesions was seen clinically in 82% and radiologically in 95% of patients. The 3‐year local relapse free survival was 64.3%, distant metastasis‐free survival was 46.1% and overall survival was 82.8%. There were no differences in outcomes between patients with clinically versus radiologically detected CN lesions. Conclusion: Most of these patients are likely to undergo clinical and/or radiological resolution of the nerve lesions following chemoradiotherapy, but the outcome was not determined by the mode of diagnosis (radiological or clinical). 相似文献
55.
Berna DL Broekhuizen Alfred PE Sachs Arno W Hoes Karel GM Moons Jan WK van den Berg Willem H Dalinghaus Ernst Lammers Theo JM Verheij 《The British journal of general practice》2010,60(576):489-494
Background
Chronic obstructive pulmonary disease (COPD) and asthma are underdiagnosed in primary care.Aim
To determine how often COPD or asthma are present in middle-aged and older patients who consult their GP for persistent cough.Design of study
A cross-sectional study in 353 patients older than 50 years, visiting their GP for persistent cough and not known to have COPD or asthma.Setting
General practice in the Netherlands.Method
All participants underwent extensive diagnostic work-up, including symptoms, signs, spirometry, and body plethysmography. All results were studied by an expert panel to diagnose or exclude COPD and/or asthma. The reproducibility of the panel diagnosis was assessed by calculation of Cohen''s κ statistic in a sample of 41 participants.Results
Of the 353 participants, 102 (29%, 95% confidence interval [CI] = 24 to 34%) were diagnosed with COPD. In 14 of these 102 participants, both COPD and asthma were diagnosed (4%, 95% CI = 2 to 7%). Asthma (without COPD) was diagnosed in 23 (7%, 95% CI = 4 to 10%) participants. Mean duration of cough was 93 days (median 40 days). The reproducibility of the expert panel was good (Cohen''s κ = 0.90).Conclusion
In patients aged over 50 years who consult their GP for persistent cough, undetected COPD or asthma is frequently present. 相似文献56.
Shawn A Ritchie Pearson WK Ahiahonu Dushmanthi Jayasinghe Doug Heath Jun Liu Yingshen Lu Wei Jin Amir Kavianpour Yasuyo Yamazaki Amin M Khan Mohammad Hossain Khine Khine Su-Myat Paul L Wood Kevin Krenitsky Ichiro Takemasa Masakazu Miyake Mitsugu Sekimoto Morito Monden Hisahiro Matsubara Fumio Nomura Dayan B Goodenowe 《BMC medicine》2010,8(1):1-20
Background
There are currently no accurate serum markers for detecting early risk of colorectal cancer (CRC). We therefore developed a non-targeted metabolomics technology to analyse the serum of pre-treatment CRC patients in order to discover putative metabolic markers associated with CRC. Using tandem-mass spectrometry (MS/MS) high throughput MS technology we evaluated the utility of selected markers and this technology for discriminating between CRC and healthy subjects.Methods
Biomarker discovery was performed using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Comprehensive metabolic profiles of CRC patients and controls from three independent populations from different continents (USA and Japan; total n = 222) were obtained and the best inter-study biomarkers determined. The structural characterization of these and related markers was performed using liquid chromatography (LC) MS/MS and nuclear magnetic resonance technologies. Clinical utility evaluations were performed using a targeted high-throughput triple-quadrupole multiple reaction monitoring (TQ-MRM) method for three biomarkers in two further independent populations from the USA and Japan (total n = 220).Results
Comprehensive metabolomic analyses revealed significantly reduced levels of 28-36 carbon-containing hydroxylated polyunsaturated ultra long-chain fatty-acids in all three independent cohorts of CRC patient samples relative to controls. Structure elucidation studies on the C28 molecules revealed two families harbouring specifically two or three hydroxyl substitutions and varying degrees of unsaturation. The TQ-MRM method successfully validated the FTICR-MS results in two further independent studies. In total, biomarkers in five independent populations across two continental regions were evaluated (three populations by FTICR-MS and two by TQ-MRM). The resultant receiver-operator characteristic curve AUCs ranged from 0.85 to 0.98 (average = 0.91 ± 0.04).Conclusions
A novel comprehensive metabolomics technology was used to identify a systemic metabolic dysregulation comprising previously unknown hydroxylated polyunsaturated ultra-long chain fatty acid metabolites in CRC patients. These metabolites are easily measurable in serum and a decrease in their concentration appears to be highly sensitive and specific for the presence of CRC, regardless of ethnic or geographic background. The measurement of these metabolites may represent an additional tool for the early detection and screening of CRC. 相似文献57.
Wael K Al-Delaimy Graeme N Mahoney Frank E Speizer Walter C Willett 《Cancer epidemiology, biomarkers & prevention》2002,11(11):1400-1404
Currently used biomarkers of tobacco smoke exposure have several disadvantages, including that they reflect short-term exposure and can therefore be affected by day-to-day variations. The aim of this study was to assess the validity of toenail nicotine levels as a biomarker of exposure to tobacco smoke for use in epidemiological studies. Toenails were collected in 1982 from 62,641 women participating in the Nurses' Health Study, whereas questionnaire data at that time provided information on active and passive smoke exposure. A stratified random sample of stored toenails from 106 women were selected according to their reported exposure category. Toenails were analyzed for nicotine levels by high-performance liquid chromatography. Toenail nicotine levels differed significantly according to tobacco smoke exposure (P < 0.0001). Among nonactive smokers, there was a significant difference in toenail nicotine levels between passive smokers (mean = 0.28 ng/mg) and nonexposed women (mean = 0.08 ng/mg; P = 0.0006). Among active smokers, there was also a significant difference (P = 0.04) in mean nicotine levels according to categories of cigarettes smoked (means for smokers of 1-14, 15-24, and 25 or more cigarettes/day were 0.94, 1.81, and 2.40 ng/mg). An overlap of the distribution of nicotine levels among passive and active smokers was found. Among all women, the correlation between nail nicotine levels and smoking exposure categories was r = 0.80 (P < 0.0001). The results of this study indicate that toenail nicotine level measurement is a valid biomarker for assessment of active and passive exposure to tobacco smoke. Nail nicotine levels may reflect aspects of active and passive exposure not captured by standard questionnaires and, thus, have the potential to provide better assessment of associations with health risk. 相似文献
58.
A prospective study of self-reported sleep duration and incident diabetes in women 总被引:29,自引:0,他引:29
Ayas NT White DP Al-Delaimy WK Manson JE Stampfer MJ Speizer FE Patel S Hu FB 《Diabetes care》2003,26(2):380-384
Short-term sleep restriction results in impaired glucose tolerance. To test whether habitually short sleep duration increases the risk of developing diabetes, we studied a cohort of 70,026 women enrolled in the Nurses Health Study, without diabetes at baseline, and who responded to a question about daily sleep duration in 1986. Subjects were followed until 1996 for the diagnosis of diabetes (1,969 cases). Long and short sleep durations were associated with an increased risk of diabetes diagnosis. The relative risks (RRs) for short (slept < or =5 h per day) and long (slept > or =9 h per day) sleepers were 1.57 (95% CI 1.28-1.92) and 1.47 (1.19-1.80), respectively. After adjustment for BMI and a variety of confounders, the RR was not significantly increased for short sleepers (1.18 [0.96-1.44]) but remained modestly increased for long sleepers (1.29 [1.05-1.59]). We then performed a similar analysis using only symptomatic cases (n = 1,187). Adjusted RRs for symptomatic diabetes were modestly elevated in both short (1.34 [1.04-1.72]) and long (1.35 [1.04-1.75]) sleepers. Our data suggest that the association between a reduced self-reported sleep duration and diabetes diagnosis could be due to confounding by BMI, or sleep restriction may mediate its effects on diabetes through weight gain. Sleep restriction may be an independent risk factor for developing symptomatic diabetes. 相似文献
59.
Schuler D; Otteneder M; Sagelsdorff P; Eder E; Gupta RC; Lutz WK 《Carcinogenesis》1997,18(12):2367-2371
8-Oxo-2'-deoxyguanosine (8-oxo-dG) is emerging as a useful marker for
oxidative DNA damage. Reported basal levels determined by 32P- postlabeling
(PPL) method were 10-fold or more higher than those obtained with
HPLC/electrochemical detection (ECD). This discrepancy was investigated. In
commercial calf thymus DNA, levels of 4 +/- 1 and 64 +/- 14 8-oxo-dG per
10(6) 2'-deoxynucleosides (dN) were measured by the standard HPLC/ECD and
PPL methods, respectively. DNA digestion by micrococcal nuclease/spleen
phosphodiesterase and nuclease P1 (as used in the standard PPL method),
followed by ECD analysis resulted in a level of 8 +/- 3. In calf thymus DNA
spiked with chemically synthesized 8-oxo-dGp to give an increment of 9
8-oxo-dG/10(6) dN, the added standard produced a significant increase with
HPLC/ECD but not PPL. After spiking the DNA with 90 8-oxo-dG/10(6) dN, the
added 8-oxo-dGp was detectable also with PPL, with a labeling efficiency of
65%. In order to investigate the role of ionizing radiation from 32P for
the higher 8-oxo-dG levels in PPL, incubation times and amounts of
radioactivity in the phosphorylation reaction with commercial dGp were
increased, and external irradiation of commercial dG with 32P was
investigated. All modifications resulted in higher values of 8-oxo-dG
measured, but the effect was not large enough to fully explain the
discrepancy between PPL and HPLC/ECD. Using [gamma-33P]ATP instead of
[gamma-32P]ATP or adding [33P]phosphate to a 32P-PPL assay resulted in even
higher levels of 8-oxo-dG measured. The increase in 8-oxo-dG levels during
the PPL workup is attributed to the presence and oxidation of unmodified
dGp in the reaction mixture. For a determination of true basal levels, the
PPL method will have to be modified, including the removal of dGp prior to
the phosphorylation reaction.
相似文献
60.
A series of promoting and non-promoting barbiturates and hydantoins were
examined for their ability to sustain the growth of a phenobarbital
(PB)-dependent hepatocyte line in cell culture. The effective liver tumor
promoters, pentobarbital, allobarbital and 5- ethyl-5-phenylhydantoin,
replaced PB and supported 6/27C1 hepatocyte colony formation in vitro at
52-87% of the level induced by PB. The weak promoters secobarbital and
amobarbital supported colony formation at only 11-19% of the PB control. A
significant correlation was observed for in vivo and in vitro promotion
activities of barbiturates and hydantoins, indicating that clonal expansion
by 6/27C1 hepatocytes was promoter-dependent. Cell density also appeared to
influence hepatocyte growth in vitro. Hepatocyte colonies acquired the
ability to grow in the absence of PB, such that after 10 days incubation
with PB, approximately 50% of colonies continued to grow in the absence of
promoter. This phenomenon of clone-size-dependent hepatocyte growth
suggested the operation of an autocrine growth factor pathway. Addition of
the hepatocyte mitogen and autocrine growth factor, transforming growth
factor-alpha (TGF-alpha), to culture medium lacking PB induced a
dose-dependent increase in 6/27C1 hepatocyte colony formation. At the
optimal concentration of 3 ng/ml, TGF-alpha sustained hepatocyte clonal
expansion at 84% of the level induced by 2 mM PB. Individual 6/27C1
colonies that grew from single cells in the presence of TGF-alpha were
tested for promoter-dependent colony formation. Either PB or TGF-alpha
supported colony formation by these cells at similar levels and when
combined at optimal concentrations, the response appeared to be saturated.
When these factors were tested in combination at suboptimal concentrations,
the two compounds were additive for supporting colony formation by the
parental 6/27C1 line. The ability of TGF-alpha to replace PB and sustain
hepatocyte clonal expansion was confirmed with the tumorigenic 6/15
hepatocyte line. These results suggest that TGF- alpha and PB may promote
hepatocarcinogenesis by stimulating a common signal transduction pathway.
相似文献