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PubMed1988

Comparative bone marrow clastogenicity of cigarette sidestream, mainstream and recombined smoke condensates in mice.

The chromosome-damaging effects of cigarette sidestream (SS) and mainstream (MS) smoke condensates and a mixture of these were compared in 8-week-old NMRI mice by intraperitoneal administration. Each filtered commercial brand of cigarette was smoked by a smoking machine under the standard conditions, and the separately collected SS and MS smoke condensates were extracted with acetone/methanol as described elsewhere. The extracts were tested before and after treatment of animals with an enzyme inducer (Aroclor 1254) or inhibitor (Metyrapone). Increased formation of micronuclei within polychromatic erythrocytes (PCEs) of femural bone marrow 30 h after injection of the extracts was regarded as being due to a clastogenic effect. Regardless of the type of smoke extract injected, the increased formation of micronuclei was found to be dose dependent. The SS smoke condensate induced approximately 29% more micronuclei than the MS smoke condensate, the difference being significant (P less than 0.01). The overall clastogenicity of a 1:1 mixture of SS and MS smoke condensates was not substantially different from the activity of either SS or MS smoke condensate alone. Pretreatment of animals with Aroclor clearly enhanced the differences between the number of micronucleated PCEs caused by SS versus MS smoke condensate; SS smoke condensate induced 50% more micronuclei than did MS smoke condensate (P less than 0.001). Pretreatment of mice with Metyrapone did not modify appreciably the induction of micronuclei by either type of smoke. These results are discussed with reference to our previous data involving inhalation experiments and the recent issue of passive smoking.

Animals↗

PubMed2004

Evaluation of DNA damage in mice topically exposed to total particulate matter from mainstream and sidestream smoke from cigarettes and bidis.

The genotoxic potential of total particulate matter (TPM) from mainstream smoke (MS) and sidestream smoke (SS) of Indian smoking products, namely cigarettes and bidis, as well as a brand of US cigarettes, was studied by determining the levels of bulky aromatic DNA adducts in mouse tissues. TPM from MS or SS of various smoking products [equal weights (2.5 mg) or the amount derived from equal (0.25) cigarette/bidi] was applied topically to mouse skin once a day for four consecutive days and adduct levels were determined in DNA from skin and lung by (32)P-post-labelling analysis. Relatively higher levels of bulky aromatic DNA adducts were noted in mouse skin treated with MS from a single Indian non-filter (INF) cigarette when compared with MS of a single bidi (with about half the product weight and one-quarter the tobacco compared with a cigarette), while comparable adduct levels were noted with SS from these two products. Considering the differences in the yields of constituents of tobacco smoke from the different products analyzed, the genotoxic potential of INF, Indian filter king (IFK) and American filter (AF) cigarettes as well as bidis was determined by topically applying an equal amount of TPM (rather than equal product-derived TPM). SS-derived TPM from all the products showed relatively higher levels of total polycyclic aromatic hydrocarbons and induced relatively higher levels of bulky aromatic DNA adducts than those derived from MS. The data indicate that TPM (MS + SS) from cigarettes appears to be more genotoxic than that from bidis and the contribution of tendu leaf (a non-tobacco bidi wrapper) to the generation of bulky aromatic DNA adducts appears to be significant, particularly in SS of bidis. Topical pretreatment with curcumin decreased the levels of TPM-derived adducts while pretreatment with dietary turmeric failed to show such protection.

Acetone↗

PubMed2002

Mainstream and sidestream cigarette smoke inhibit growth and angiogenesis in the day 5 chick chorioallantoic membrane.

The purpose of this study was to test the hypothesis that components in mainstream (MS) and sidestream (SS) cigarette smoke inhibit growth and angiogenesis using the chick chorioallantoic membrane (CAM). Varying doses of whole or gas-phase MS and SS smoke solutions were placed on day 5 CAMs, and their effects on angiogenesis were evaluated on day 6. All parameters evaluated (CAM area, major blood vessel area, major blood vessel diameter, blood vessel pattern formation, and capillary plexus formation) were inhibited to different degrees in a dose-dependent manner by both MS and SS smoke treatment. Inhibition of growth and vessel development was correlated with inhibition of cell proliferation. Inhibition of capillary plexus formation was caused by failure of mesodermal blood vessels to migrate to the ectoderm. SS smoke solution was more inhibitory than MS smoke solution in all assays, except for capillary plexus formation. In all assays, the toxicants in SS smoke partitioned mainly with the gas phase, whereas those in MS smoke were deduced to be mainly in the particulate phase in the proliferation-dependent assays (CAM area, blood vessel area, blood vessel diameter) and in both the gas and particulate phase in the pattern formation and plexus formation assays. Some of the inhibitory doses of MS and SS smoke solutions had nicotine concentrations within the range found in human smokers. Taken together, these data demonstrate that exposure to complex mixtures of chemicals in MS and SS cigarette smoke adversely affect growth, vessel development, vessel migration, and cell proliferation.

Allantois↗

PubMed2002

The relative toxicity of substituted phenols reported in cigarette mainstream smoke.

Cigarette mainstream smoke (MS) contains a number of structurally diverse substituted phenols. Recent quantitative structure activity relationship (QSAR) studies on phenols show that substituted phenols with electron-releasing groups can form potentially toxic phenoxyl-free radicals. In contrast, substituted phenols with electron-withdrawing groups do not form phenoxyl-free radicals but exert their toxicity primarily through lipophilicity. The chemical structures of 253 different substituted phenols reported in MS have been described in sufficient detail to allow identification of the individual compounds. From a laterally validated equation based on published data on the toxic effects of phenols on cultured cells, the relative toxicity, on a molar basis, of the 253 MS phenols has been determined. Based on this scheme, the most toxic phenols in MS include, in descending order of toxicity, 2-(dimethylamino)-phenol, 2-ethyl-6-methyl-1,4-benzenediol, 2-methoxy-1,4-benzenediol, and 4-ethyl-2-methoxy-6-methylphenol. The least toxic phenols include, in ascending order of toxicity, 4-hydroxybenzoic acid and 3-hydroxybenzenepropanoic acid. In the human exposure situation, the toxicity of MS phenols is a complex interaction, with contributions made by the following factors: toxicity per mole; MS concentration; synergistic, additive or antagonistic interactions with other MS components; host susceptibility; metabolism; and individual smoking behavior and inhalation patterns. In the absence of data to the contrary, reduction in the number and concentration of toxic MS smoke components may be considered to be advantageous. Studies of this type can play an important role in identifying MS components for reduction or removal.

Animals↗

PubMed2004

Lung tumorigenicity in A/J and rasH2 transgenic mice following mainstream tobacco smoke inhalation.

Hypothesizing that their respective genetic backgrounds would confer an increased sensitivity to lung tumorigenesis, the plausibility of selected rodent models for the inhalation testing of mainstream tobacco smoke (MTS) was evaluated. Strain A/J and rasH2 transgenic (Tg) mice were exposed to MTS from Kentucky 1R4F research cigarettes using either a whole-body or nose-only exposure regimen. The whole-body regimen consisted of a 20-week exposure period [0.200 mg wet total particulate matter/liter (WTPM/l), 6 h/day, 5 days/week]; nose-only dosing proceeded for 28 weeks [0.040, 0.125, or 0.400 mg WTPM/l, 3 h/day, 5 days/week]. Both regimens included a 16-week recovery period. Gross and microscopic examinations of the lungs were used to evaluate tumor formation, with experimental results supporting the following conclusions: 1. Evaluation of MTS-induced tumorigenicity based on gross evaluation versus microscopic confirmation provides strikingly disparate results, indicating that serial sectioning is necessary for a definitive assessment of lung tumors. 2. While the dosing regimens employed do not allow for a definitive comparison, whole-body exposure appeared to be more effective for inducing statistical changes in tumor multiplicity and incidence compared to nose-only exposure. 3. Exposure-related stress, evidenced as reductions in both body weight gain and background tumor formation, represents a potential confounder during inhalation testing of MTS tumorigenicity, with additional investigation warranted to validate the specificity of exposure-related responses. 4. Comparative findings between A/J and rasH2 Tg mice suggest that the former may be overly sensitive to exposure-related stress, potentially influencing tumorigenic responses.

Administration, Intranasal↗

PubMed2004

Chronic inhalation exposure to mainstream cigarette smoke increases lung and nasal tumor incidence in rats.

An animal model of lung carcinogenicity induced by chronic inhalation of mainstream cigarette smoke would be useful for research on carcinogenic mechanisms, smoke composition-response relationships, co-carcinogenicity, and chemoprevention. A study was conducted to determine if chronic whole-body exposures of rats would significantly increase lung tumor incidence. Male and female F344 rats (n = 81 to 178/gender) were exposed whole-body 6 h/day, 5 days/week for up to 30 months to smoke from 1R3 research cigarettes diluted to 100 (LS) or 250 (HS) mg total particulate matter/m(3), or sham-exposed to clean air (C). Gross respiratory tract lesions and standard lung and nasal sections were evaluated by light microscopy. A slight reduction of survival suggested that the HS level was at the maximum tolerated dose as commonly defined. Cigarette smoke exposure significantly increased the incidences of non-neoplastic and neoplastic proliferative lung lesions in females, while nonsignificant increases were observed in males. The combined incidence of bronchioloalveolar adenomas and carcinomas in females were: HS = 14%; LS = 6%; and C = 0%. These incidences represented minima because only standard lung sections and gross lesions were evaluated. Mutations in codon 12 of the K-ras gene occurred in 4 of 23 (17%) tumors. Three mutations were G to A transitions and one was a G to T transversion. The incidence of neoplasia of the nasal cavity was significantly increased at the HS, but not the LS level in both males and females (HS = 6%, LS = 0.3%, C = 0.4% for combined genders). These results demonstrate that chronic whole-body exposure of rats to cigarette smoke can induce lung cancer.

Administration, Inhalation↗

PubMed1995

Ciliary beat frequency of hamster oviducts is decreased in vitro by exposure to solutions of mainstream and sidestream cigarette smoke.

Epidemiological data support a correlation between smoking and increased incidence of ectopic pregnancy, yet the causal mechanism responsible for this relationship is unknown. The purpose of this study was to examine the effect of solutions containing dissolved mainstream (MS) or sidestream (SS) cigarette smoke on ciliary beat frequencies (CBF) in explants of hamster oviducts. MS smoke is the puff inhaled by an active smoker, while SS smoke leaves the burning end of cigarette. SS smoke is inhaled by both active and passive smokers. Experiments were performed in handmade perfusion chambers using infundibula from hamster oviducts. After a short incubation in Earle's balanced salt solution containing HEPES buffer (EBSS-H), chambers were flushed with one of six types of smoke solution prepared in EBSS-H, and incubation continued 19 min. A second perfusion (washout) was then done using EBSS-H alone to determine whether effects induced by the smoke solutions could be reversed. CBF were determined at three times in both the smoke and washout solutions, and means were compared to values obtained in the initial EBSS-H incubation. All smoke solutions except the SS particulate solution inhibited CBF in a dose-dependent manner. Whole MS and whole SS smoke solution at the highest strength tested caused the greatest inhibition and in some cases completely stopped ciliary beating. Both single-strength and 0.1-strength MS gas phase solutions, which contained concentrations of nicotine in the range found in typical human smokers, produced about 50% inhibition of ciliary beating. Inhibition was generally seen within 2-12 min of adding smoke solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1999

Mainstream personality psychology and the study of religion.

In this commentary, I make some general observations about the study of personality and religion and some specific comments about individual articles from the perspective of contemporary personality psychology. Most of the authors represented here treat religion as a domain of human experience and behavior that can be understood in terms of familiar personality principles and processes. I therefore urge greater attention to the Five-Factor Model of personality traits, especially Openness to Experience, in understanding religious phenomena. Mainstream psychologists, including longitudinal researchers, behavior geneticists, and epidemiologists, should consider the inclusion of religious variables in their research designs.

Humans↗

PubMed2006

Mainstreaming risk reduction in urban planning and housing: a challenge for international aid organisations.

The effects of 'natural' disasters in cities can be worse than in other environments, with poor and marginalised urban communities in the developing world being most at risk. To avoid post-disaster destruction and the forced eviction of these communities, proactive and preventive urban planning, including housing, is required. This paper examines current perceptions and practices within international aid organisations regarding the existing and potential roles of urban planning as a tool for reducing disaster risk. It reveals that urban planning confronts many of the generic challenges to mainstreaming risk reduction in development planning. However, it faces additional barriers. The main reasons for the identified lack of integration of urban planning and risk reduction are, first, the marginal position of both fields within international aid organisations, and second, an incompatibility between the respective professional disciplines. To achieve better integration, a conceptual shift from conventional to non-traditional urban planning is proposed. This paper suggests related operative measures and initiatives to achieve this change.

City Planning↗

PubMed2006

Can mainstream health services provide meaningful care for people who self-harm? A critical reflection.

People who self-harm currently access health care based in a wide variety of settings. These include primary care, accident and emergency departments, and specialist mental health providers. This paper considers whether meaningful care for people who self-harm can be provided within these mainstream health services. The paper begins by clarifying the meaning of self-harm and distinguishes self-harm from suicide. Four treatment models applied in clinical practice are identified: (i) psychodynamic, (ii) behavioural, (iii) biosocial and (iv) feminist. Each of these is critically considered in terms of practical utility, professional attitudes and wider organizational/policy context.

Attitude of Health Personnel↗

PubMed2006

Atrial fibrillation ablation: reaching the mainstream.

INTRODUCTION AND AIMS: Ablation of atrial fibrillation (AF) has evolved rapidly in the decade since its inception. We aimed to review the results of this evolution as reflected in the published literature. METHODS: Publications through 2005 were reviewed, and data included if there was information on the technique used, and follow-up of at least 6 months. RESULTS: More than 23,000 patients met criteria for inclusion. There has been a steady improvement in reported outcomes (P<0.001). Variations on radiofrequency catheter ablation for pulmonary vein isolation result in apparent elimination ("cure") or improvement of AF in 75%, and surgical techniques are even better. CONCLUSIONS: Catheter ablation of AF is now a mainstream procedure. Continuing technical advances are needed to achieve better results with more uniformity and reduced procedure times.

Atrial Fibrillation↗

PubMed2005

The prevalence of child-psychiatric disorders among 8-9-year-old children in Danish mainstream schools.

OBJECTIVE: Prevalence rates for child psychopathology in Denmark are unknown; and efficient screening and non-respondent analyses are essential for epidemiological purposes. METHOD: A multi-method strategy involving a two-step design: first screening of 621 children between the ages of 8-9 years attending mainstream education using the Child Behaviour Checklist (CBCL). Second, screen-positive probands and a sample of screen-negative probands were given in-depth child-psychiatric assessment. In cases of non-respondents, children were assessed by teachers. RESULTS: CBCL screening results were compared with case status in clinical assessment. A positive predictive value of 0.25 and a correct classification rate (CCR) of 0.72 were obtained. The teacher interviews, used in cases of non-respondents, had a CCR of 0.87. According to DSM-IV criteria, the prevalence rate of psychiatric disorders was 10.l% [95% CI; 7.0-13.2]. CONCLUSIONS: The CBCL proved an effective screening tool. The brief interview with teachers is a valid assessment of psychiatric disorders among non-respondents.

Child↗

PubMed1965

POLONIUM-210 CONTENT OF MAINSTREAM CIGARETTE SMOKE.

When eleven brands of cigarettes were smoked in a standardized manner, differences in the polonium-210 content of various brands were found. The differences were not directly related to the presence of a filter or to the construction of the filter, but were related to the amount of particulate matter in the mainstream smoke.

Chemistry Techniques, Analytical↗

PubMed2004

Determination of tar, nicotine, and carbon monoxide yields in the mainstream smoke of selected international cigarettes.

OBJECTIVE: Survey of nicotine, tar, and carbon monoxide (CO) smoke deliveries from 77 cigarette brands purchased in 35 countries was conducted using a standardised machine smoking method. The goal of this study was to determine regional variations and differences in the tar, nicotine, and CO smoke yields of a cigarette brand manufactured by a leading transnational corporation and of non-US locally popular cigarette brands. DESIGN: The majority of the cigarettes were purchased in each of the participating countries by delegate members of the World Health Organization and forwarded to the Centers for Disease Control and Prevention for analysis. Smoke deliveries were determined using a standardised smoking machine method and subsequent gravimetric and gas chromatography analysis. RESULTS: The smoke deliveries varied widely. Mainstream smoke deliveries varied from 6.8 to 21.6 mg tar/cigarette, 0.5 to 1.6 mg nicotine/cigarette, and 5.9 to 17.4 mg CO/cigarette. In addition to the smoke deliveries, the cigarettes were examined to determine physical parameters such as filter composition, length, and ventilation levels. CONCLUSION: Analysis of the smoke deliveries suggested that cigarettes from the Eastern Mediterranean, Southeast Asia, and Western Pacific WHO regions tended to have higher tar, nicotine, and CO smoke deliveries than did brands from the European, American, or African WHO regions surveyed.

Air Pollutants↗

PubMed1999

[Motivation for the choice of complementary and mainstream medicine. Patients' behavior in a pluralistic medical system].

The reasons for choosing between various therapeutic possibilities depend in part on rational and in part on emotional factors. This project dealt with the systematic verification of some decision factors most of which were known already. The project was divided in a qualitative and a quantitative part. The qualitative segment was based on semistructured interviews with patients of general practitioners or of naturopaths. This procedure is often used in ethnological research. It identified and evaluated the main motives for the individual choices of therapies by the patients. The quantitative part of the study was carried out by a procedure often used in social sciences, namely by strictly structured telephone interviews of several thousand policyholders of the health insurance fund Helvetia. The aim of this part of the study was to verify the findings of the qualitative study and to investigate the possible significance of additional sociological factors for the choice between different therapies. The conclusions drawn from the abundance of data show that a widespread use of complementary medicine is a reality. Both parts of the project came to the same conclusions. The patients use complementary medicine in a very pragmatic way, be it alternately, be it in parallel but not necessarily in addition to mainstream medicine. The behavior of the patients is very complex, depends on many factors, and can neither be predicted nor easily influenced, not even by an additional free insurance for complementary medicine which was offered to one of the subgroups of the study (in conjunction with J. Sommer's project 'A Randomized Experiment Studying the Effect of Including Complementary Medicine in the Mandatory Benefit Package of Health Insurance Funds in Switzerland'). The interpretation of the telephone interviews concerning the significance of some of the registered sociological factors turned out to be difficult. The project aimed primarily at illustrating the use of complementary medicine and at characterizing its users.

Attitude to Health↗

PubMed1999

[Quality of life of pregnant women in homeopathic or mainstream medical type of care and the course of the pregnancy].

This study investigated 120 pregnant women cared for and treated by physicians specialized in homeopathy and 85 pregnant women cared for and treated by mainstream gynecologists. Quality of life was assessed twice during pregnancy and once shortly after delivery by the instrument SEIQoL (Schedule for the Evaluation of Individualized Quality of Life). In addition, the study registered individual personality characteristics, the psychological situation, the attitude towards the forthcoming delivery, and the functional state before and after delivery. It turned out that women who preferred homeopathic care judged their quality of life lower than women from the other group. However, their criteria for medical decisions and for the assessment of their own personal situation differed as well. There was some correlation between quality of life and age, number of deliveries, partnership and certain personality characteristics. The study showed the importance of paying more attention to the subjective world of the pregnant women. This applies especially in an analysis of two dissimilar therapeutic systems. It could also be concluded that the SEIQoL was a useful instrument for such a study. Finally it turned out that the two populations investigated were different.

Attitude to Health↗

PubMed1998

Stroke risk management: changes in mainstream practice.

BACKGROUND: Research shows that identification and control of risk factors reduces ischemic stroke. The impact of this evidence and health initiatives on mainstream practice remains unknown. METHODS: The purpose of this observational study was to investigate prior management of risk factors (hypertension, atrial fibrillation, previous stroke/transient ischemic attacks) in patients with acute cerebral infarction. Data were collected on the frequency of known risk factors before the incident stroke and their management compared with predefined criteria for appropriateness. The proportion of patients receiving treatment for risk factors before the acute episode was studied over 3 years. RESULTS: One thousand seventy-four patients (median age, 76 years; 60% women) were included in the study over 3 years. The proportion of patients with known hypertension (41% to 46%), diabetes (12% to 13%), previous stroke or transient ischemic attack (TIA) (21% to 31%), and atrial fibrillation (16% to 21%) remained stable. Overall, approximately 45% patients with atrial fibrillation, 60% patients with hypertension, and 70% with cerebrovascular disease were being actively managed. Time trends analysis showed a significant increase in the proportion of patients being treated for risk due to known cerebrovascular disease (59% to 85%), atrial fibrillation (18% to 59%), ischemic heart disease (35% to 72%), and carotid disease (13% to 85%) between the first and third year. The proportion of patients receiving treatment for hypertension remained unchanged. Patients with preexisting symptomatic vascular disease were more likely to receive appropriate risk management compared with asymptomatic patients (72% versus 46%, P<.001). CONCLUSIONS: Although a significant number of ischemic events remain potentially preventable, there appears to be a positive trend in improved control of stroke risk.

Acute Disease↗

PubMedDate not supplied

A review of chronic inhalation studies with mainstream cigarette smoke in rats and mice.

In this paper, I review the results of a representative selection of chronic inhalation studies with rats and mice exposed to mainstream cigarette smoke and describe the inhalation exposures and the histopathological changes reported by various authors. Many of the studies used nose-only exposure systems, whereas others simply used large whole-body chambers. Smoke-induced epithelial hypertrophy, hyperplasia, and squamous metaplasia were reported in the conducting airways in most of the studies, along with increased numbers of intra-alveolar macrophages that were occasionally associated with alveolar metaplasia. Lung adenomas and adenocarcinomas were reported in only a few of the studies. No statistically significant increase in the incidence of malignant lung tumors was seen in either species as a result of smoke exposure, a finding that does not agree with the results of epidemiological studies in humans. Possible reasons for this lack of correlation are given.

Animals↗