Invertebrate responses to the management of genetically modified herbicide-tolerant and conventional spring crops. I. Soil-surface-active invertebrates.

The effects of herbicide management of genetically modified herbicide-tolerant (GMHT) beet, maize and spring oilseed rape on the abundance and diversity of soil-surface-active invertebrates were assessed. Most effects did not differ between years, environmental zones or initial seedbanks or between sugar and fodder beet. This suggests that the results may be treated as generally applicable to agricultural situations throughout the UK for these crops. The direction of the effects was evenly balanced between increases and decreases in counts in the GMHT compared with the conventional treatment. Most effects involving a greater capture in the GMHT treatments occurred in maize, whereas most effects involving a smaller capture were in beet and spring oilseed rape. Differences between GMHT and conventional crop herbicide management had a significant effect on the capture of most surface-active invertebrate species and higher taxa tested in at least one crop, and these differences reflected the phenology and ecology of the invertebrates. Counts of carabids that feed on weed seeds were smaller in GMHT beet and spring oilseed rape but larger in GMHT maize. In contrast, collembolan detritivore counts were significantly larger under GMHT crop management.

Invertebrate responses to the management of genetically modified herbicide-tolerant and conventional spring crops. II. Within-field epigeal and aerial arthropods.

The effects of the management of genetically modified herbicide-tolerant (GMHT) crops on the abundances of aerial and epigeal arthropods were assessed in 66 beet, 68 maize and 67 spring oilseed rape sites as part of the Farm Scale Evaluations of GMHT crops. Most higher taxa were insensitive to differences between GMHT and conventional weed management, but significant effects were found on the abundance of at least one group within each taxon studied. Numbers of butterflies in beet and spring oilseed rape and of Heteroptera and bees in beet were smaller under the relevant GMHT crop management, whereas the abundance of Collembola was consistently greater in all GMHT crops. Generally, these effects were specific to each crop type, reflected the phenology and ecology of the arthropod taxa, were indirect and related to herbicide management. These results apply generally to agriculture across Britain, and could be used in mathematical models to predict the possible long-term effects of the widespread adoption of GMHT technology. The results for bees and butterflies relate to foraging preferences and might or might not translate into effects on population densities, depending on whether adoption leads to forage reductions over large areas. These species, and the detritivore Collembola, may be useful indicator species for future studies of GMHT management.

Segregation analysis of two lung function indices in a random sample of young families: the Humboldt Family Study.

The Humboldt Family Study was conducted in the town of Humboldt, Saskatchewan, in 1993. Familial correlations and segregation analyses of lung function were carried out in 799 individuals in 214 nuclear families that included 214 fathers, 214 mothers, and 371 children. Forced expiratory volume in 1 second (FEV1) and maximal mid-expiratory flow rate (MMFR) were first regressed on age, height, weight, and their quadratic and cubic terms as well as on smoking status in four groups separately (mothers, fathers, daughters, and sons), with terms significant at the 0.10 level being retained. Residual phenotypes were standardized within the four groups. Class D regressive models were used to perform familial correlations and segregation analyses. For both FEV1 and MMFR, father-mother correlations were not significantly different from zero, and mother-offspring, father-offspring, and sibling-sibling correlations showed no statistically significant difference from each other. Based on the "polygenic" models, the estimated intraclass correlation is 0.132 (+/- 0.035) for FEV1 and 0.171 (+/- 0.039) for MMFR, and the narrow-sense heritability is 0.264 for FEV1 and 0.342 for MMFR. Segregation analysis shows that the "mixed" model with both single locus and polygenic components had a better fit for FEV1 than single-locus or polygenic only models. However, the model which included a nontransmitted environmental factor [tau(AA) = tau(AB) = tau(BB) = qA] and polygenic loci had a better fit than the Mendelian model [tau(AA) = 1, tau(AB) = 1/2, tau(BB) = 0] [Akaike's information criterion (AIC) = 2219.47 vs. AIC = 2222.14]. For MMFR, the Mendelian "mixed" model gave a nonsignificant improvement in loge likelihood compared to the simple polygenic model. Comparison of the single-locus model and Mendelian "mixed" model shows no difference in fitting the data. This study suggests that FEV1 and MMFR are controlled by many loci with no major effects and/or common environmental factors.

The influence of smoking cessation on body weight may be temporary.

The relationships of bodyweight and body mass index with smoking cessation were examined among 1633 adults in Humboldt, Saskatchewan, Canada. Mean body mass index was highest in ex-smokers and lowest in smokers, and that of non-smokers was intermediate. Body mass index decreased significantly with increasing years after smoking cessation in female ex-smokers after adjusting for age, education, location of work, and physical activity. This trend, however, was not significant in men. The body weight data showed similar results. The prevalence of obesity (body mass index greater than 30 kg/m2) in all subjects showed a decrease with increasing years after smoking cessation.

Body weight and weight gain related to pulmonary function decline in adults: a six year follow up study.

BACKGROUND: Obesity increases the risk of cardiovascular disease, hypertension, diabetes, digestive diseases, and some cancers. Several studies have shown that excess weight or weight gain is related to pulmonary dysfunction, but this issue needs to be further clarified. METHODS: The analysis was based on data of the Humboldt cohort study which was conducted in the town of Humboldt, Saskatchewan, Canada. The baseline survey in 1977 included 1202 adults, comprising 94% of all residents aged 25-59 years. Of these, 709 (59%) were followed up in 1983. Pulmonary function (forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and maximal mid expiratory flow rate (MMFR) and weight were measured in both surveys. Weight gain was determined by subtracting weight at baseline from weight at follow up. A residual analysis was used to examine the relationship between body mass index (BMI) at baseline, weight gain, and pulmonary function decline. RESULTS: Both BMI at baseline and weight gain were significantly related to pulmonary function at follow up. The effect of weight gain during the study period, however, was more prominent. The results showed that both mean residual FVC and FEV1 were highest in the group that gained < 1.0 kg, lowest in the group that gained > or = 4.0 kg, and intermediate in the group that gained 1.0-3.9 kg in both men and women after taking age, BMI at baseline, and smoking into account. The effect of weight gain on pulmonary function was greater in men than in women. Multiple regression analysis showed that each kilogram of weight gain was associated with an excess loss of 26 ml in FVC and 23 ml in FEV1 in men, and 14 ml and 9 ml respectively in women. CONCLUSIONS: Weight gain is significantly related to lung dysfunction. The effect of weight gain on pulmonary function is greater in men than in women.

Risk factors for reduced pulmonary function in women. A possible relationship between Pi phenotype, number of children, and pulmonary function.

Smoking and severe deficiency of protease inhibitor (Pi Z phenotype) both contribute significantly to the development of chronic obstructive pulmonary disease (COPD). The role of moderate Pi deficiency (Pi MZ phenotype) remains controversial. During a community-wide study of respiratory health which included 1,633 individuals, of whom 897 were women, we measured forced vital capacity (FVC), forced expired flow in 1 s (FEV1), midmaximum expired flow rate (MMFR), flow rate at 50 percent of FVC (Vmax50%) and flow rate at 25 percent of FVC above residual volume (Vmax25%). We carried out Pi phenotyping on 544 of these women, including 22 who were Pi MZ or FZ phenotypes. There were no statistically significant differences in mean pulmonary function (pf) values between the Pi MZ and Pi M women. Examination of residual pf values (difference between observed and expected) by means of multiple multivariate regression analysis revealed that in Pi MZ women, FEV1/FVC%, MMFR, Vmax50%, and Vmax25% had significantly greater values with increasing numbers of children, whereas there was no relationship in the Pi M women. These results suggest that some factors may interact differently in individuals with Pi M and MZ phenotypes. In addition, the results suggest that pregnancy or pregnancy-induced increased Pi levels may have significant effects on the pulmonary health of Pi MZ women.

Combined effect of grain farming and smoking on lung function and the prevalence of chronic bronchitis.

The combined effect of grain farming and smoking on lung function and the prevalence of chronic bronchitis was examined in 1633 residents 20 to 65 years of age from the town of Humboldt, Saskatchewan. Multiple multivariate analysis indicated that in women grain farming and smoking had a significant synergistic effect on the values of forced expired volume in one second/forced vital capacity (FEV1/FVC), mid-expiratory flow rate (MMFR), flow rate at 50% and 25% of total volume (Vmax50 and Vmax25) after adjustment for covariates including age and height. No other factors were found to change the results. The combined effect of grain farming and smoking on lung function was not statistically significant in men. The data also show that female non-smoking grain farmers had an identical prevalence of chronic bronchitis compared with non-smoking female non-farmers, 2.0% versus 2.1%. But in women with a positive smoking history, the prevalence was 13.2% and 5.9% respectively, giving an adjusted odds ratio in grain farmers compared to non-farmers of 3.55 (95% confidence interval (Cl): 1.06-11.30). It was found that the prevalence of chronic bronchitis increased more rapidly with increasing cigarette consumption in grain farmers than in non-farmers in women. It was estimated that 85%, 72% and 66% of the prevalence of chronic bronchitis was attributed to the joint effects of grain farming and ex-smoking, light smoking (1-19 cigarettes/day) or heavy smoking (20+ cigarettes/day) status, respectively. In contrast to women, the effect of grain farming on the prevalence of chronic bronchitis was similar in men with and without a positive smoking history. Our data suggest that there is a positive interactive effect of grain farming exposure and smoking on lung function and the prevalence of chronic bronchitis in women. The difference in the interaction between men and women requires further study.

Increased susceptibility to lung dysfunction in female smokers.

The interaction between sex and smoking habits on pulmonary function was examined among 1,149 adults 25 to 59 yr of age in a rural community in Saskatchewan. Pulmonary function tests included FVC, FEV1, maximal midexpiratory flow rate (MMFR), the slope of phase III of the single-breath nitrogen test (delta N2/L), and closing volume as a percent of vital capacity (CV/VC). The data show that after fixing the effects of age, height, and weight by analysis of covariance, the adjusted means of delta N2/L in nonsmokers, ex-smokers, and current smokers were 0.92, 1.10, and 1.60% in women and 0.97, 1.05, and 1.23% in men, respectively. The difference in the adjusted means for delta N2/L between smokers and nonsmokers was larger in women than in men, 0.67% versus 0.26%, respectively. Multiple multivariate analyses show that the regression slopes for the residuals of FEV1, MMFR, and delta N2/L versus pack-years were significantly different between men and women. The regressions of FEV1 and MMFR decreased and the regression of delta N2/L increased with increasing pack-years more rapidly in women than in men. The combined effect of sex and pack-years on pulmonary function was not significant for ex-smokers. These data suggest that cigarette smoking may be more detrimental in its effects on lung function in women than in men.

Ethnicity as a possible factor contributing to the development of chronic airflow limitation and asthma.

Race or ethnicity have occasionally been cited as possible factors contributing to the risk of developing obstructive lung disease. In a hospital based case-control study of Caucasian patients with asthma or chronic airflow limitation (CAL), we determined the frequency of each of five major European ethnic groups in the patients. We then compared the two patient groups to each other and to the frequencies reported by Canada Census and found significant differences in their ethnic constitution. Our results suggest that the British are more likely than other groups, especially North Eastern Europeans, to develop CAL, while North Eastern Europeans and Scandinavians are more likely to develop asthma. These differences could be due to genetic differences among the various groups or to environmental factors associated with particular ethnic groups. They suggest that ethnicity is an additional factor to consider in future epidemiological studies of CAL or asthma.

Possible protective effect against chronic obstructive airways disease by the GC2 allele.

The frequencies of GC phenotypes in 104 patients with chronic obstructive airways disease (COAD) were compared with those in 413 control subjects. The distributions were significantly different with fewer patients with the GC 2 allele than expected (relative risks = 0.8, 0.7 and 0.5 for 2-2, 2-1S and 2-1F, respectively) and more 1F-1F patients than expected (relative risk = 4.8). These data suggest that the GC 2 allele exerts a protective effect, whereas 1F, when homozygous, increases the risk of developing COAD.

Ethnic differences in the prevalence of pulmonary airflow obstruction among grain workers.

World Health Organization data suggest that British males over 45 have a higher death rate from chronic bronchitis, emphysema, and asthma combined than do other Europeans. Although widely supposed that this is due to particularly unfavorable environmental factors in the British Isles, as well as a higher rate of tobacco consumption, ethnicity itself may be a significant factor in determining risk of obstructive airways disease. To test this hypothesis, we have analyzed the prevalence of airflow obstruction (100 x FEV1:FVC less than 68% and FEV1 less than 84 percent predicted) in Saskatchewan grain workers of British, German, and Eastern European ancestry using the Mantel-Haenszel odds ratio (OMH) and stepwise logistic regression. We found that the British grain workers had a significantly greater prevalence of airflow obstruction (OMH = 3.2; p less than 0.01) than the Eastern Europeans. We also found that ethnic origin made a significant contribution to the estimation of risk of airflow obstruction among grain workers independent of the effects of age and smoking.

Pulmonary function in Pi M and MZ grainworkers.

Twenty-eight men with the Pi MZ phenotype who have been employed in the Saskatchewan country grain elevators and thus regularly exposed to high levels of grain dust, were case matched for age, years of employment, employment status, smoking status, and smoking history with grainworkers of type Pi M. Individuals answered a questionnaire, had a chest roentgenogram, skin tests, and performed a battery of pulmonary function tests. There were no differences between the two groups in prevalence of symptoms or atopy. Although not statistically significant, the MZ group had three times as many individuals with abnormal roentgenograms suggestive of COPD as the M group. The Pi MZ grainworkers had consistently poorer mean results for the pulmonary function tests with significantly lower mean values for FEV1, FEV1/FVC, MMFR, and Vmax50, leading us to suggest that Pi MZ individuals may be at higher risk of COPD than Pi M individuals, but only in the presence of other risk factors such as grain dust exposure.

Pi MZ phenotype and an increased prevalence of reported psoriasis in a community survey.

In a community survey of 953 adults we identified 40 who reported having had psoriasis. Eight of these cases were subsequently documented from physicians' records. alpha 1-Antitrypsin (alpha 1-AT) phenotyping identified 35 MZ individuals, 4 (11.4%) of whom reported psoriasis. Among the 918 non-MZ individuals 36 (3.9%) reported psoriasis, yielding a relative incidence of 3.2 (p less than 0.05). This is consistent with previous reports suggesting an association between moderate alpha 1-AT deficiency and psoriasis.

Pi type MZ and an increased risk of pneumonia.

Among 114 men of Pi type or MZ, 42% (17/40) of those of Pi type MZ reported having been told by a physician that they had had pneumonia at least once whereas only 18% (13/74) of those of Pi type M did so (p less than 0.05). This significant difference could not be accounted for by differences in age, smoking status, occupation or baseline lung function (FEV1). Examination of medical records of those reporting pneumonia for the preceding 20 years provided confirmation of the diagnosis of pneumonia and support for the association; 12% (5/40) of the MZ group but only 3% (2/74) of the M group had confirmed episodes of pneumonia during the preceding 20 years. Since alpha 1-antitrypsin has been implicated as a factor in inflammatory response, reduced levels may permit the development of more frequent and/or more serious episodes of pneumonia.

Alpha 1-antitrypsin phenotypes in Canadian Metis.

Alpha 1-antitrypsin phenotyping was performed on serum of 344 Metis living in an isolated northern Saskatchewan community. Only PiM and PiMZ phenotypes were observed with phenotype frequencies of 98.5 and 1.5 respectively. Gene frequencies were 0.993 for PiM and 0.007 for PiZ. The low frequency of non-M phenotypes is similar to that in another population of North American natives, the Eskimos of Igloolik as well as Finnish and Norwegian Lapps.

A new anodal alpha 1-antitrypsin variant associated with emphysema: Pi Bsaskatoon.

A new anodal alpha 1-antitrypsin (alpha 1 AT) variant was identified in a 48-yr-old woman with severe pulmonary emphysema. Isoelectric focusing produced extra bands lying between those of the Pi B and Pi C variants. The new variant was present in 2 of her 3 siblings, 5 of 11 offspring, and probably in her father, all in the heterozygous state. Mean serum alpha 1 AT concentrations and elastase inhibitory capacities were the same in variant and M offspring. The father had reported emphysema, the 2 variant siblings had documented emphysema, and 1 of 5 variant offspring had an area of focal emphysema. The Pi type M sibling and the remaining 10 offspring had no emphysema. Despite normal concentrations and activities, this new variant, which has been designated "Bsaskatoon," may be associated with the development of emphysema within this family.

Increased mortality in the siblings and offspring of Pi type MS and MZ men from Saskatchewan. Mortality and Pi type.

alpha 1-Antitrypsin phenotypes were determined in 1,395 male Saskatchewan grain buyers. These included 1,254 type M, 80 MS, 35 MZ and 26 which were untyped or other rare phenotypes. Sibling and offspring of the MS men had a significantly greater number of deaths (p less than 0.01). Offspring of MZ men also had an increased number of deaths. These appeared to occur in all age except in those 2-17 years of age. This finding raises questions about the role of both the S and Z alleles.

Pulmonary emphysema associated with the FZ alpha 1-antitrypsin phenotype.

In one family three brothers were found to have a moderate deficiency of alpha 1-antitrypsin associated with the unusual Pi (protease inhibitor) phenotype FZ. The Pi phenotypes of their six living siblings were found to be FM (in three), M (in two) and MZ (in one). The three FZ brothers all had moderate to severe obstructive airways disease, and two had at least moderately severe pulmonary emphysema. Additional risk factors included moderate cigarette smoking in two and prolonged exposure to grain dust in all three. The same risk factors applied to the six non-FZ siblings, but they had only mild symptoms and pulmonary dysfunction or no lung problems at all; one, a female smoker with the MZ phenotype, had probable early emphysema demonstrated radiologically. The three FZ men may have had reduced fertility, as they produced only 1 child among them, as compared with 39 among the other eight siblings. This family study thus suggests that individuals with the FZ phenotype are at risk for pulmonary emphysema and chronic obstructive airways disease, particularly in the presence of other risk factors, such as cigarette smoking and grain dust exposure.