Prevalence, frequency and problem rating of hot flushes persist in older postmenopausal women: impact of age, body mass index, hysterectomy, hormone therapy use, lifestyle and mood in a cross-sectional cohort study of 10,418 British women aged 54-65

OBJECTIVE

Hot flushes and night sweats (HFs/NSs) are the main menopausal symptoms, but few studies have been adequately powered to examine the dimensions or predictors of experiencing HFs/NSs. We report on these variables in a large UK cohort of postmenopausal women.

DESIGN

Cross-sectional cohort study.

SETTING

UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) cohort.

POPULATION

A cohort of 202,638 postmenopausal women, aged 50-74 years, without oophorectomy, recruited to UKCTOCS between 2001 and 2005.

METHODS

Women completed a follow-up questionnaire, and those aged 54-65 years were mailed a survey in July 2008.

MAIN OUTCOME MEASURES

  Hot flush prevalence and hot flush rating scale.

RESULTS

Of the 15,000 women mailed, 10,418 returned completed questionnaires; 90% had previously had HFs/NSs. Despite being on average 10 years postmenopausal, 54% experienced HFs/NSs (frequency of 33 per week with mean problem rating 4/10) that persisted across the age range. Past hysterectomy (OR 1.50, 95% CI 1.19-1.86), ever having smoked (OR 1.27, 95% CI 1.11-1.46) and alcohol consumption (current units) (OR 1.05, 95% CI 1.01-1.09) predicted ever having had HFs/NSs. Anxiety (OR 3.09, 95% CI 2.57-3.72), hysterectomy (OR 2.74, 95% CI 2.32-3.25), depressed mood (OR 1.57, 95% CI 1.24-1.99), years since last menstrual period (OR 0.95, 95% CI 0.94-0.96) and education (above and below 18 years) (OR 0.98, 95% CI 0.97-0.99) predicted the current prevalence of HFs/NSs. Few predictors of frequency were identified, but problem rating was associated with depressed mood, hysterectomy, skirt size increase and frequency of HFs/NSs. Past hormone therapy users who had discontinued treatment were more likely to have HFs/NSs that were more frequent and problematic.

CONCLUSIONS

To date, this is the largest UK study of the experience of HFs/NSs amongst older postmenopausal women. HFs/NSs are more prevalent in this age band than has previously been assumed. These findings and the associations of smoking, hysterectomy, anxiety, depressed mood and hormone therapy use with the experience of HFs/NSs have implications for prevention and symptom management.

Development of an aquatic pathogen database (AquaPathogen X) and its utilization in tracking emerging fish virus pathogens in North America

The AquaPathogen X database is a template for recording information on individual isolates of aquatic pathogens and is freely available for download (http://wfrc.usgs.gov). This database can accommodate the nucleotide sequence data generated in molecular epidemiological studies along with the myriad of abiotic and biotic traits associated with isolates of various pathogens (e.g. viruses, parasites and bacteria) from multiple aquatic animal host species (e.g. fish, shellfish and shrimp). The cataloguing of isolates from different aquatic pathogens simultaneously is a unique feature to the AquaPathogen X database, which can be used in surveillance of emerging aquatic animal diseases and elucidation of key risk factors associated with pathogen incursions into new water systems. An application of the template database that stores the epidemiological profiles of fish virus isolates, called Fish ViroTrak, was also developed. Exported records for two aquatic rhabdovirus species emerging in North America were used in the implementation of two separate web-accessible databases: the Molecular Epidemiology of Aquatic Pathogens infectious haematopoietic necrosis virus (MEAP-IHNV) database (http://gis.nacse.org/ihnv/) released in 2006 and the MEAP- viral haemorrhagic septicaemia virus (http://gis.nacse.org/vhsv/) database released in 2010.

Assessing the malignant potential of ovarian inclusion cysts in postmenopausal women within the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS): a prospective cohort study

OBJECTIVE

To evaluate the malignant potential of ultrasound-detected ovarian inclusion cysts in the development of ovarian cancer (OC) in postmenopausal women.

DESIGN

Prospective cohort study.

SETTING

UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS).

POPULATION

Postmenopausal women.

METHODS

In UKCTOCS, women in the ultrasound group have annual scans. Women with inclusion cysts (single/multiple anechoic ≤10-mm ovarian cysts) and normal ovaries (both uniform hypoechogenicity) on their first scan were identified and followed up through cancer registry/questionnaires.

MAIN OUTCOME MEASURES

Relative risk (RR) of developing OC, invasive epithelial ovarian cancer (iEOC), breast cancer (BC) and endometrial cancer (EC) in women with inclusion cysts relative to those with normal ovaries. The incidence was compared with UK age-adjusted expected rates (Office for National Statistics, 2005).

RESULTS

Postmenopausal women (n = 48,230) attended the year 1 (11 June 2001-6 December 2006) screen; 1234 (2.5%) had inclusion cysts alone and 22,914 had normal scans. By 1 November 2009 (median follow-up, 6.13 years; interquartile range, 4.96-6.98 years), four, three (one Type II), seven and 22 women with inclusion cysts and 32, 29 (20 Type II), 90 and 397 women with normal ovaries were diagnosed with OC, iEOC, EC and BC, respectively. The RR values for the respective cancers (OC [RR, 2.32; confidence interval [CI], 0.86-6.28], iEOC [RR, 1.92; CI, 0.62-5.92], EC [RR, 1.44; CI, 0.68-3.05], BC [RR, 1.12; CI, 0.73-1.73]) were not increased. There was no difference between the observed versus expected incidence rates for these cancers in women with inclusion cysts.

CONCLUSIONS

Postmenopausal women with ultrasound-detected inclusion cysts do not seem to be at increased risk of ovarian or breast/endometrial (hormone-dependent) cancers.

Why members of the public self-test: an interview study

BACKGROUND

A wide range of self-tests are available where contact with a health professional is not necessary.

OBJECTIVE

To investigate factors that influenced members of the public to use self-tests.

METHODS

Questionnaires, sent to 2335 adults from two general practices in North Birmingham, asked whether recipients had used self-tests and sought consent for contacting them about taking part in an interview. Twenty-three people were interviewed, 20 of whom had used self-tests. The interviews were transcribed verbatim, and a thematic analysis was conducted.

RESULTS

The findings were organized around two themes. 'Motivations for self-testing' describes the motivating factors surrounding participants' choices to use self-tests. This appeared to be influenced by a number of factors that were organized into four sub-themes: 'diagnosis or speculation', 'perceived benefits of self-testing', 'general attitudes to and experiences of health care' and 'general attitudes to health'. The second theme called 'experience of self-testing' describes participants' access to, and use of self-tests, and is split into three sub-themes: 'opportunistic awareness and access', 'use and application' and 'impact on life'.

CONCLUSIONS

Overall, self-testing encompasses a broad variety of beliefs and experiences. Some participants saw self-tests as a serious diagnostic tool, whereas others used them out of simple curiosity. Some were motivated by their generally positive attitude to health, but others may have been motivated by negative health care experiences. Some saw self-testing as an empowering process to be proud of, while others seemed to view it as an illegitimate activity that needed to be hidden from professionals.

Pertussis outbreak in northwest Ireland, January – June 2010

We report a community pertussis outbreak that occurred in a small town located in the northwest of Ireland. Epidemiological investigations suggest that waning immunity and the absence of a booster dose during the second year of life could have contributed to the outbreak. The report also highlights the need to reinforce the surveillance of pertussis in Ireland and especially to improve the clinical and laboratory diagnosis of cases.

Pertussis outbreak in northwest Ireland, January - June 2010

We report a community pertussis outbreak that occurred in a small town located in the northwest of Ireland. Epidemiological investigations suggest that waning immunity and the absence of a booster dose during the second year of life could have contributed to the outbreak. The report also highlights the need to reinforce the surveillance of pertussis in Ireland and especially to improve the clinical and laboratory diagnosis of cases.

Comprehensive analysis of karyotypic mosaicism between trophectoderm and inner cell mass

Aneuploidy has been well-documented in blastocyst embryos, but prior studies have been limited in scale and/or lack mechanistic data. We previously reported preclinical validation of microarray 24-chromosome preimplantation genetic screening in a 24-h protocol. The method diagnoses chromosome copy number, structural chromosome aberrations, parental source of aneuploidy and distinguishes certain meiotic from mitotic errors. In this study, our objective was to examine aneuploidy in human blastocysts and determine correspondence of karyotypes between trophectoderm (TE) and inner cell mass (ICM). We disaggregated 51 blastocysts from 17 couples into ICM and one or two TE fractions. The average maternal age was 31. Next, we ran 24-chromosome microarray molecular karyotyping on all of the samples, and then performed a retrospective analysis of the data. The average per-chromosome confidence was 99.95%. Approximately 80% of blastocysts were euploid. The majority of aneuploid embryos were simple aneuploid, i.e. one or two whole-chromosome imbalances. Structural chromosome aberrations, which are common in cleavage stage embryos, occurred in only three blastocysts (5.8%). All TE biopsies derived from the same embryos were concordant. Forty-nine of 51 (96.1%) ICM samples were concordant with TE biopsies derived from the same embryos. Discordance between TE and ICM occurred only in the two embryos with structural chromosome aberration. We conclude that TE karyotype is an excellent predictor of ICM karyotype. Discordance between TE and ICM occurred only in embryos with structural chromosome aberrations.

Prevalence of the use of self-tests by adults in the United Kingdom: a questionnaire survey

BACKGROUND

Self-tests that people can do without a health professional are widely available, but there is little information about how many people have used one. Our aim was to describe the prevalence of use.

METHODS

An initial questionnaire, sent to 8048 adults registered with six general practices in North Birmingham and Warwickshire and Worcestershire, asked whether the person had self-tested. A second questionnaire validated the use for people from the final four practices by asking how each self-test had been obtained and why it had been used.

RESULTS

The age-standardised prevalence of confirmed use for any self-test other than for pregnancy or high blood pressure was 47 (95% confidence interval (CI): 37-57) per 1000 women and 22 (95% CI: 14-30) per 1000 men. If everyone who initially reported use but did not return an eligible second questionnaire had the same rates of confirmed use as eligible responders, this would increase to 95 (95% CI: 81-110) per 1000 women and 55 (95% CI: 41-68) per 1000 men.

CONCLUSION

An appreciable minority of the population have self-tested for medical conditions.

Using electronic mail to improve MMR uptake amongst third level students

This study assessed the usefulness of email in informing third level students about special MMR clinics being provided on campus during a mumps outbreak in the North West of Ireland. Email messages were sent directly to students, informing them of the clinics, inviting them to make a clinic appointment by email and providing details of walk-in clinics. At the clinics, all 177 attendees were asked to fill out a questionnaire and the response rate was 89% (n=158). Regarding the main sources of information about the vaccination clinics, email was selected by 117 (74%) students, word-of-mouth by 27 (17%), posters/leaflets by 8 (5%), and other sources by 6 (4%). Use of email as a source of information was rated as very good/excellent by 115 (73%), as good by 35 (22%) and poor/fair by 8 (5%). This study demonstrates that email is a useful and acceptable way of informing third level students about immunisation clinics in an outbreak situation.

Validation studies from the Western Australian Congenital Malformations Registry

A series of studies was undertaken in 1989 to validate the data held by the Western Australian Congenital Malformations Registry. Comparison with hospital discharge data identified 1585 children six years of age or younger with malformations discharged from hospitals in Western Australia in 1986, 226 of whom were not already recorded on the Congenital Malformations Register. When the records of a special register for cleft lip and palate were examined, all cases of facial cleft known to the special register were also recorded on the Malformations Register. Comparison of the Western Australian data for major groups of malformations with data from the South Australian Birth Defects Register raised the possibility of under ascertainment in Western Australia of cases of congenital heart disease. Multiple sources of ascertainment and evaluation of the ways in which such sources are tapped are important factors in striving for complete and accurate information on congenital malformations for research and public health purposes.

Preclinical validation of a microarray method for full molecular karyotyping of blastomeres in a 24-h protocol

BACKGROUND

Preimplantation genetic screening (PGS) has been used in an attempt to determine embryonic aneuploidy. Techniques that use new molecular methods to determine the karyotype of an embryo are expanding the scope of PGS.

METHODS

We introduce a new method for PGS, termed 'parental support', which leverages microarray measurements from parental DNA to 'clean' single-cell microarray measurements on embryonic cells and explicitly computes confidence in each copy number call. The method distinguishes mitotic and meiotic copy errors and determines parental source of aneuploidy.

RESULTS

Validation with 459 single cells of known karyotype indicated that per-cell false-positive and false-negative rates are roughly equivalent to the 'gold standard' metaphase karyotype. The majority of the cells were run in parallel with a clinical commercial PGS service. Computed confidences were conservative and roughly concordant with accuracy. To examine ploidy in human embryos, the method was then applied to 26 disaggregated, cryopreserved, cleavage-stage embryos for a total of 134 single blastomeres. Only 23.1% of the embryos were euploid, though 46.2% of embryos were mosaic euploid. Mosaicism affected 57.7% of the embryos. Counts of mitotic and meiotic errors were roughly equivalent. Maternal meiotic trisomy predominated over paternal trisomy, and maternal meiotic trisomies were negatively predictive of mosaic euploid embryos.

CONCLUSIONS

We have performed a major preclinical validation of a new method for PGS and found that the technology performs approximately as well as a metaphase karyotype. We also directly measured the mechanism of aneuploidy in cleavage-stage human embryos and found high rates and distinct patterns of mitotic and meiotic aneuploidy.

Is Metabolic Syndrome and Central Obesity Relevent to Biology and Progression of Postmenopausal Breast Cancer?

Introduction: Obesity isassociated with both an increased risk of postmenopausal breast cancer and increased mortality rates. The mechanism is unclear, and central (visceral) obesity, insulin resistance, altered sex steroids, and altered adipokines, are mooted as possible factors. These features may cluster in the so-called Metabolic Syndrome (MetS), and the focus of this study was to systematically relate MetS to standard clinicopathological indices of breast cancer.Methods: Postmenopausal women with newly diagnosed breast cancer (n=105) were prospectively recruited. A detailed clinical and dietary history was performed, as well as body composition analysis, metabolic screen, and plasma measurement of adipokines and inflammatory markers. MetS was defined according to the International Diabetes Federation definition.Results: One hundred and five patients were recruited, the median age was 68 years (40-94) and the mean BMI was 28.3 ± 5.2 kg/m2, with 87% of patients centrally obese. MetS was diagnosed in 39% of patients, and was significantly (p<0.005) associated with 13cm greater waist circumference, higher total and trunk fat mass and increased inflammation with CRP levels almost double for MetS patietns compared to non MetS (10.3 ± 2.7 V's 5.8 ± 1.0 mg/L; p=0.084).Patients with later pathological stage (II- IV) were significantly more likely to be obese (BMI) (45% Vs 16%; p=0.007), centrally obese (waist circumference) (94% Vs 72%; p=0.009), hyperglycaemic (31% Vs 12%; p=0.047), hyperinsulinaemia (19% Vs 0; p=0.026) and 51% had MetS compared to 12% for early stage disease (Path stage 0-I). Patients with node positive disease were significantly more likely to be hyperinsulaemic (22% V's 5%; p=0.030) and have MetS (50% V's 30%; p=0.028) than node negative disease.MetS was not associated with hormone receptor status or serum levels of oestradiol, progesterone, testosterone, or SHBG levels. However, SHBG levels decreased with obesity (p=0.002) and as the number of features of MetS increased (0 features: 87 ± 15.8 compared to 5 features: 32 ±2.7; p=0.003). Insulin levels increased with obesity (p=0.006), and with increasing number of features of MetS.Discussion: MetS and central obesity are common in Irish postmenopausal breast cancer patients. MetS appears to be associated with aggressive tumour biology, and this may have significance in preventive and novel treatment approaches.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1051.

Vandetanib, a Dual Inhibitor of Vascular Endothelial Growth Factor Receptor (VEGFR) and Epidermal Growth Factor Receptor (HER1), Potentiates Anti-Tumor Effects of Combined Endocrine and Trastuzumab Treatment in Estrogen Receptor-Positive (ER+)/HER2-Overexpressing Xenografts

Background: Compelling evidence suggests that cross-talk between the pathways of ER and HER1/HER2 contributes to endocrine resistance. Using a xenograft model of human ER+ breast cancer cells engineered to overexpress HER2 (MCF-7/HER2-18), we have shown that tamoxifen (Tam) stimulates tumor growth resulting in de novo resistance. Anti HER1/HER2 targeted treatment overcomes this Tam resistant phenotype, though these effects are transient using single agents like the anti-HER2 antibody trastuzumab (T), thus suggesting that a more potent anti-HER therapy or simultaneous inhibition of alternative pathways is required to reverse resistance. Both ER and HER2 are known to promote angiogenesis. Vandetanib (V) (ZD6474, ZACTIMA) is an orally active, VEGFR/HER1 tyrosine kinase inhibitor that has shown both anti-angiogenic and anti tumor cell activities in different models. We thus hypothesize that in ER+/HER2+ tumors, the addition of V to the combination regimen of Tam+T would increase antitumor effect and delay onset of resistance due to inhibition of tumor angiogenesis and delivery of a more complete blockade of the HER network.Methods: Mice bearing MCF-7/HER2-18 tumors were randomized and treated with Tam given alone or in combination with T (10 mg/Kg, bi-weekly), V (50 mg/Kg, 5 d/week), or T+V. Tumor volumes were followed weekly. Mean tumor regression (M-TR) ± SD and median time to tumor progression (M-TTP, defined by tumor doubling from its size at randomization) and 95% CIs were analyzed by Wilcoxon Rank Sum and survival analysis methods (Kaplan-Meier estimates and generalized Wilcoxon test), respectively. All statistical tests were two-sided and adjusted (Holm) for multiple comparisons.Results: Tam monotherapy had minimal effect on tumor growth (M-TR 22%±15 SD) after which all tumors progressed rapidly [M-TTP 42 (35-56) days, 95% CI]. The addition of either T or V to Tam significantly improved tumor regression compared to Tam monotherapy (M-TR 66%±27, P=0.0012, and 67%±25, P=0.001, respectively) and significantly delayed time to tumor progression [M-TTP 91 (70-119) days, P=0.012, and 77 (63-98) days, P=0.02, respectively]. However, the combined regimen of T+V with Tam was significantly more effective than either T or V added separately to Tam, resulting in further significant tumor regression (M-TR 81%±29, P=0.0086 vs. T and 0.0012 vs. V) and a prolonged M-TTP (>154 d, P=0.02 vs. T and 0.01 vs. V).Conclusions: This study supports the concept that the dual VEGFR/HER1 inhibitor vandetanib can improve efficacy of combined endocrine and anti-HER trastuzumab therapy in ER+/HER2+ tumors, probably due to angiogenesis inhibition and to a more potent blockade of HER family signaling and its cross-talk with ER. Clinical studies to examine this approach are warranted.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5128.

A Culturally-Specific Dietary Plan To Manage Weight Gain among African American Breast Cancer Survivors: A Feasibility Study

Background. African American (AA) women are less likely to survive for five years after a breast cancer diagnosis than Caucasian women. The higher prevalence of obesity in AA women may contribute to this disparity. Weight gain following breast cancer treatment is one of the few modifiable risk factors for breast cancer recurrence and mortality. AA breast cancer survivors face unique cultural and economic barriers to adopting diets which reduce the likelihood of weight gain.Objective. To determine the feasibility of adopting and maintaining a culturally-specific low-fat eating plan in a population of low to middle income AA breast cancer survivors.Participants. AA women recruited through urban medical centers who were between 30 to 75 years old, had a confirmed diagnosis of stage 0, I, II, III, or IIIA primary breast cancer, and had incomes < $50,000 per year.Methods. A culturally-specific dietary intervention was developed, based on the Women's Intervention Nutrition Study (WINS), to reduce consumption of dietary fat to 25% of total calories, while increasing fruits and vegetables.Eligible participants were enrolled in a one-year feasibility study. Participants received the Culturally-Specific WINS Low-Fat Eating Plan (WLEP) and 8 individual nutritional counseling sessions with a trained diet technician, to help reduce and maintain their fat intake to 25% of total calories. The intervention also included bi-monthly educational group meetings and follow-up telephone contacts with diet technicians.Study Measures. Dietary patterns were assessed with 3-day food records at baseline and follow-up. Compliance with the Culturally-Specific WLEP was defined as 1) dietary fat intake ≤ 25% of total calories; and 2) at least 6 to 7 servings of fruits and vegetables per day. Psychosocial factors and dietary biomarkers were also measured at baseline and follow-up to examine their association with study outcomes. Psychosocial factors included perceived susceptibility to recurrence, quality of life, and social support. Dietary biomarkers included weight, height, waist-hip circumference, blood pressure, lipids, serum fatty acid concentrations, insulin and insulin-like growth factors, glucose, and levels of sex hormone-binding globulins.Results. A total of 9 AA breast cancer survivors are enrolled and receiving the intervention. Baseline and six-month follow-up results for the psychosocial factors and dietary biomarkers associated with dietary compliance and weight maintenance will be reported in October 2009.Conclusions. A population of low to middle income AA breast cancer survivors with limited education and resources demonstrated compliance with the Culturally-Specific WLEP, thereby reducing their risk of cancer recurrence through diet. Procedures and data from this feasibility study will be used in a multi-center clinical trial of the Culturally-Specific WLEP.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1053.

Radiomimetic Cell Cycle Delay Induced by Tetranodecanoyl Phorbol Acetate is Enhanced by Caffeine and by the Protein Kinase Inhibitor 2-aminopurine

The tumour promoter and protein kinase C agonist, 12-O-tetranodecanoyl-phorbol-13-acetate (TPA), has been reported to show a radiomimetic action because it transiently delays the passage of HeLa cells through the G2 phase, as do ionizing radiation and other DNA damaging agents. Caffeine is known to override the G2 delay imposed by DNA damage; it is shown here that caffeine does not override the radiomimetic delay imposed by TPA in HeLa, but instead enhances it, without affecting G2 progression in control cells. Most of the other agents which more specifically affect some of the diverse range of caffeine targets either do not affect G2 progression after TPA, or delay G2 progression in control cells and exert a further delay in the presence of TPA. The exception is 2-aminopurine, a protein kinase inhibitor which has been shown to have an action similar to that of caffeine is allowing progression of the cell cycle to mitosis after the inhibition of DNA synthesis, without affecting normal cycle progression through G2. This agent, like caffeine, also has the contrary action of retarding cycle progression after TPA. It is concluded that the G2 delays induced by ionizing radiation and by TPA operate by different mechanisms, which are modulated in opposite senses by mechanisms involving protein kinase inhibition.

VTE prophylaxis across the continuum of care in U.S. cancer patients

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Background: The period of VTE risk in cancer patients extends beyond the hospital stay. This analysis evaluated VTE prophylaxis patterns for US cancer patients across the continuum of care. Methods: Premier's Perspective inpatient data were cross-matched with Ingenix LabRx outpatient data from the I3 database (January 2005-December 2007) to assess VTE prophylaxis patterns in medical cancer patients at risk of VTE (according to the American College of Chest Physicians 2004 guidelines) and with no contraindications for anticoagulation. Inpatient anticoagulant groups were assigned based on the drug the patient received during hospital stay and were followed by their outpatient prophylaxis use. Patients were evaluated on drug utilization, diagnoses and clinical practice patterns during and after hospitalization. Results: Overall, 75.3% of 2,337 cancer patients did not receive anticoagulation during their hospital stay. Of the 577 patients receiving prophylaxis, 66% received UFH and 25% received enoxaparin ( Table ). The mean length of hospital stay was 3 days after which 97.9% of patients did not receive any prophylaxis within the following 30 days. Of the 50 patients who received outpatient prophylaxis, 60% received warfarin alone and 22% received both enoxaparin and warfarin. Conclusions: This unique analysis presents VTE prophylaxis patterns across the continuum of care. Most cancer patients did not receive anticoagulation in the inpatient or outpatient settings. Further efforts are needed to identify optimal VTE prevention in cancer patients, namely the duration of prophylaxis and how healthcare providers can increase awareness. Financial and editorial support was provided by sanofi-aventis US, Inc.

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Defining hybrid poplar (Populus deltoides x Populus trichocarpa) tolerance to ozone: identifying key parameters

This study examined whether two genotypes of hybrid poplar (Populus deltoides x Populus trichocarpa), previously classified as ozone tolerant and ozone sensitive, had differing physiological and biochemical responses when fumigated with 120 nL L(-1) ozone for 6 h per day for eight consecutive days. Isoprene emission rate, ozone uptake and a number of physiological and biochemical parameters were investigated before, during and after fumigation with ozone. Previous studies have shown that isoprene protects plants against oxidative stress. Therefore, it was hypothesized that these two genotypes would differ in either their basal isoprene emission rates or in the response of isoprene to fumigation by ozone. Our results showed that the basal emission rates of isoprene, physiological responses and ozone uptake rates were all similar. However, significant differences were found in visible damage, carotenoids, hydrogen peroxide (H(2)O(2)), thiobarbituric acid reactions (TBARS) and post-fumigation isoprene emission rates. It is shown that, although the classification of ozone tolerance or sensitivity had been previously clearly and carefully defined using one particular set of parameters, assessment of other key variables does not necessarily lead to the same conclusions. Thus, it may be necessary to reconsider the way in which plants are classified as ozone tolerant or sensitive.