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We previously reported a strong positive association between vasectomy and the risk of prostatic cancer that arose in multiple comparisons made within data collected from 1976 to 1988 in an ongoing hospital-based surveillance study of many exposures and diseases. We have reassessed this association with data collected in the surveillance study during 1988-1992 from a new set of patients (355 cases of prostatic cancer and 2,048 controls with nonmalignant conditions). Because some studies have reported increased relative risks of lung cancer and testicular cancer in vasectomized men, we also used the surveillance database (4,126 men with various cancers, 7,027 men with nonmalignant conditions) to assess the relation of vasectomy to the risk of these and other cancers. In the newly collected data, the multivariate relative risk estimate for prostatic cancer in vasectomized men was 1.2 (95% confidence interval (CI) 0.6-2.7). For lung cancer and testicular cancer, the relative risk estimates were 1.3 (95% CI 0.8-2.1) and 0.8 (95% CI 0.4-1.9), respectively; for lung cancer occurring > or = 15 years after vasectomy, the relative risk estimate was 1.9 but it was not statistically significant (95% CI 0.7-5.0). For pancreatic cancer, the relative risk estimate was 1.8 (95% CI 1.0-3.1). For each of the other cancers considered--malignant melanoma, large bowel cancer, bladder cancer, kidney cancer, lymphoma, leukemia, and other cancers--the relative risk estimate was 1.3 or less and compatible with a value of 1.0. The present data provide little support for an association of vasectomy with the risk of prostatic cancer or other cancers. In addition, the data from two sets of cases of prostatic cancer and controls interviewed consecutively illustrate that increased relative risks detected in screening for statistically significant associations may tend to have an upward bias and to be lower in subsequent data.

The authors undertook a case-control study to explore the many factors that have been postulated to be related to the etiology of systemic lupus erythematosus. A total of 195 cases of systemic lupus diagnosed in the Philadelphia, Pennsylvania, metropolitan area between 1985 and 1987 were compared with 143 controls, friends of the cases matched to them according to age (+/- 5 years) and sex. Through personal interviews and chart reviews, data were collected on demographic factors, personal and familial medical history, reproductive history, medication history, and environmental exposures. Associations were found between systemic lupus erythematosus and having a family history of autoimmune disease (age-, sex-, and race-adjusted odds ratio (OR) = 2.3, 95% confidence interval (CI) 1.2-4.6), a history of shingles (adjusted OR = 6.4, 95% CI 1.4-28.0), a history of hives (adjusted OR = 1.8, 95% CI 1.1-3.0), and a history of medication allergies (adjusted OR = 2.6, 95% CI 1.5-4.5). No association was present between systemic lupus erythematosus and either any use or recent use of oral contraceptives (e.g., OR = 0.6 (95% CI 0.2-1.4) for use in the 3 years prior to diagnosis), family history of multiple other diseases, or a history of numerous other infections or various other types of allergies. Thus, these data indicate that systemic lupus erythematosus is associated with a family history of autoimmune diseases, a history of shingles, and a history of allergies. In contrast, if the development of systemic lupus is affected by use of oral contraceptives, this effect must be extremely modest. These findings may help clarify the possible pathogenesis of systemic lupus erythematosus, and they provide clues as to when the presence of systemic lupus should be suspected.

The relation of oral contraceptive use to the risk of ovarian cancer was assessed with data collected during 1977-1991 from patients under 65 years of age in hospitals in Boston, New York, Philadelphia, and Baltimore. We compared 441 women with recently diagnosed invasive epithelial ovarian cancer to 2,065 control women. Logistic regression was used to control risk factors for ovarian cancer. The multivariate relative risk estimate decreased with the increasing duration of oral contraceptive use (p < 0.05): the estimate was close to 1.0 for duration categories of less than 3 years; it was reduced for the categories of 3-4 years of use and greater, but it did not decline further as the duration of use increased. For > or = 3 years of use, the estimate was 0.6 (95% confidence interval 0.4-0.8). The inverse association of risk with > or = 3 years of use was consistently present across categories of age, parity, interview year, and geographic area. It was apparent for as long as 15-19 years after cessation. Many different specific oral contraceptive formulations appeared related to a decreased risk; however, data were sparse for the newer types, particularly phasic preparations, and the ability to assess specific preparations in the context of use of multiple preparations was limited. The present data confirm previous reports of an inverse association of ovarian cancer risk with oral contraceptive use of several years in duration. They also suggest that the association may persist for as long as two decades and that it is not confined to any particular type of oral contraceptive formulation.

The authors evaluated whether an induced or spontaneous abortion during the first six months of gestation, particularly if it occurs before the first term pregnancy, increases the risk of breast cancer. Data from a case-control study of women under 70 years of age were used: 3,200 cases of breast cancer were compared with 4,844 controls with nonmalignant nongynecologic conditions. Among both nulliparous and parous women, the risk of breast cancer was not related to the number of induced or spontaneous abortions. After allowance for all identified potential confounding factors, the estimated relative risk for nulliparous women with an induced abortion relative to those who had never been pregnant was 1.3 (95% confidence interval (CI) 0.8-2.2), and for spontaneous abortion, the corresponding estimate was 0.9 (95% CI 0.5-1.5). Among parous women, the estimated relative risks were 1.2 (95% CI 0.9-1.6) for an induced abortion and 0.9 (95% CI 0.8-1.0) for a spontaneous abortion, relative to never having had an abortion of any type. The time of the abortion had little effect: The relative risk estimates were 0.9 (95% CI 0.5-1.4) for induced abortion before the first term birth, 1.4 (95% CI 1.0-1.9) for induced abortion first occurring after the first term birth, 0.9 (95% CI 0.7-1.2) for spontaneous abortion before the first term birth, and 0.9 (95% CI 0.7-1.0) for spontaneous abortion first occurring after the first term birth. Similar results were evident for women under age 40, among whom the frequency of induced abortion was relatively high. These data suggest that the risk of breast cancer is not materially affected by abortion, regardless of whether it occurs before or after the first term birth.

Adult height has been positively associated with the risk of breast cancer in a number of recent investigations. The authors assessed height in relation to breast cancer risk in a case-control study of US black women aged 25-69 years; 674 hospital patients with newly diagnosed breast cancer and 1,155 controls hospitalized for nonmalignant conditions unrelated to height were interviewed. After control for multiple confounders, the relative risk estimate for women < 61 inches (< 154.9 cm) tall was 0.5 (95% confidence interval (Cl) 0.3-0.7) relative to the median height of 64-65 inches (162.6-165.1 cm). Among women > or = 61 inches (> or = 154.9 cm) tall, there was little indication of any variation in risk with increasing height. The findings suggest that short stature is associated with a decreased risk of breast cancer in US black women.

Some animal data have raised the possibility that benzodiazepines influence the risk of selected cancers. With data collected in 1977-1991 in a US hospital-based study, the authors assessed the relation of benzodiazepine use to the risk of 11 cancers: breast (6,056 patients), large bowel (2,203), malignant melanoma (1,457), lung (1,365), endometrium (812), ovary (767), non-Hodgkin's lymphoma (382), testis (314), Hodgkin's disease (299), thyroid (111), and liver (37). Cases were compared with cancer controls (3,777 patients with other cancers) and noncancer controls (1,919 patients admitted for acute nonmalignant disorders). Relative risks were estimated for benzodiazepine use at least 4 days a week for at least 1 month, initiated at least 2 years before admission (sustained use) by multiple logistic regression with control for confounding factors. Results derived with noncancer controls were similar to those derived with cancer controls. For sustained benzodiazepine use relative to no use, relative risk estimates for all 11 cancers were compatible with 1.0 at the 0.05 level of significance. Relative risk estimates for durations of at least 5 years were also compatible with 1.0, with the exceptions of an increased estimate, of borderline statistical significance, for endometrial cancer, and a decreased estimate for ovarian cancer. Relative risk estimates both for sustained use that continued into the 2-year period before admission and for sustained use that ended up to > or = 10 years previously were compatible with 1.0, suggesting a lack of tumor promotion and no increase in the risk after a latent interval. Results were also null for diazepam, chlordiazepoxide, and other benzodiazepines considered separately. The results suggest absence of association between benzodiazepine use and the cancers considered, with the evidence stronger for the cancers with larger numbers of subjects. The similarity of results derived with cancer and noncancer controls suggests that benzodiazepines do not influence the risk of cancer as a whole.

A methodological study was performed in 1992 to evaluate the accuracy of self-reported use of nonsteroidal antiinflammatory drugs (NSAIDs) and noncontraceptive estrogens that had been dispensed during the previous 12 years. A sample of 560 individuals dispensed NSAIDs or estrogens, and 140 individuals without NSAID/estrogen dispensations were selected from the Group Health Cooperative pharmacy database. Demographic, behavioral, and drug information was ascertained by telephone interview for 356 persons with and 98 persons without NSAID/estrogen dispensations. Of those with only a single NSAID dispensation, 41% (95% confidence interval (CI) 32-50%) were able to recall any NSAID use compared with 85% (95% CI 76-94%) for those with multiple NSAID dispensations. Thirty percent (95% CI 24-36%) recalled the NSAID name, and 15% (95% CI 10-20%) recalled both the name and dose. For estrogens, 78% (95% CI 70-86%) recalled the name, but only 26% (95% CI 17-34%) recalled the name and dose. Age, but not sex, appeared to influence recall accuracy: Persons 50-65 years of age recalled the NSAID name more accurately than those aged 66-80 (odds ratio (OR) = 1.8, 95% confidence interval (CI) 1.0-3.4). A similar advantage was noted for 50- to 65-year-old women in recalling the estrogen name (OR = 1.5, 95% CI 0.6-3.9). Drug name was recalled more frequently for exposures stopped 2-3 years prior to interview than for those stopped 7-11 years prior (OR = 3.0, 95% CI 1.6-5.7, and OR = 2.4, 95% CI 0.9-6.7, for NSAIDs and estrogens, respectively). Specificity was consistently high, ranging from 92% to 100%. This study suggests significant underascertainment of self-reported prescription drug exposure but little evidence that exposures are overreported.

It has been suggested that gallbladder removal may protect against subsequent development of myocardial infarction because of increased gastrointestinal cholesterol excretion resulting from increased enterohepatic cycling. To test this hypothesis, the authors used data from two large case-control studies of myocardial infarction--one conducted in 1976-1979 in 155 US hospitals and one conducted in 1980-1983 in 78 US hospitals. First, 550 female myocardial infarction cases were compared to 1,658 controls. Simultaneously adjusting for possible confounding variables using logistic regression, the odds ratio for development of a myocardial infarction subsequent to cholecystectomy was 0.8 (95% confidence interval, 0.5-1.1). Second, 1,511 male myocardial infarction cases were compared to 3,837 controls. With similar adjustments, the odds ratio was 0.8 (95% confidence interval, 0.5-1.2). The risk did not decline as the interval following cholecystectomy increased. The present data are compatible with a protective effect of cholecystectomy on the risk of subsequent myocardial infarction, but they are not conclusive.

Jeffrey pine, Pinus jeffreyi Greville and Balfour, is a dominant yellow pine and important overstory component of forests growing on diverse sites from southwestern Oregon to Baja California to western Nevada. The Jeffrey pine beetle, Dendroctonus jeffreyi Hopkins (Coleoptera: Curculionidae: Scolytinae), is monophagous on Jeffrey pine and its primary insect pest. Despite the importance of P. jeffreyi, difficult terrain, environmental concerns, and lack of roads can constrain pest management activities. Semiochemicals are often easier to apply and more environmentally acceptable than other options, but they are lacking in this system. Attractants have been identified, but field bioassays have been limited because of infrequent or short duration outbreaks and a lack of beetles during nonoutbreak periods. Disruptant semiochemicals have not been assessed for D. jeffreyi during outbreak conditions; however, commercially available semiochemicals have been implicated as disruptants for this bark beetle. The objective of this study was to identify the most effective commercially available attractant and disruptant semiochemicals for D. jeffreyi. Our highest observed catch occurred with the blend of 5% 1-heptanol and 95% n-heptane. When this was used to challenge potential disruptant semiochemicals, the combination of S-(-)-verbenone and the green leaf volatile blend (cis-3-Hexenol and 1-Hexanol) reduced trap catch by ˜80%. However, frontalin was most effective, reducing the number of D. jeffreyi caught by >96%. Within each year of the study, the percentage female of D. jeffreyi caught with our attractant decreased from start to end of the experimental period. On average, our first collection in a year (mid-June to early July) was 59% female, whereas our last (mid-August) was 34%. Frontalin was equally or more effective against females (the pioneering sex) than males, providing optimism that semiochemical disruption may be possible for protecting Jeffrey pines from D. jeffreyi.

With the exception of responses to semiochemicals, host selection behaviors of D. frontalis are largely unstudied. To better understand the host finding behavior of D. frontalis, and to identify potential visual disruptants, we evaluated the response of D. frontalis to multiple-funnel traps of eight different colors. Multiple-funnel traps provide an attractive vertical silhouette, similar to a host stem, that aids in capturing bark beetles and allows for controlled evaluation of visual cues. Evaluation of mean trap catch of each color by analysis of variance (ANOVA) produced two separate groups: white and yellow traps caught significantly fewer D. frontalis than the other six colors tested (black, blue, brown, gray, green, red). Examination of spectral reflectance curves showed that the eight colors could be naturally placed into two groups, those with high peak reflectance (white and yellow) and those with low peak reflectance (black, blue, brown, gray, green, red). When high and low peak reflectance were substituted for color in a separate ANOVA, reflectance group was as good as color at explaining the variability in trap catch (r2 = 0.88 versus 0.92). Therefore, hue (dominant wavelength) was unimportant in affecting D. frontalis host finding behavior at the reflectance levels we tested and, thus, we found no strong evidence that differential wavelength sensitivity affected the response of D. frontalis. These results show that dark colored silhouettes (those with low reflectance values), regardless of hue, are best for capturing D. frontalis, while white or yellow are the best candidate colors for disrupting host finding.

Host choice of late instar (LA-L6) gypsy moths, Lymantria dispar (L.), was evaluated using stems and foliage of loblolly pine, Pinus taeda L., and sweetgum, Liquidambar styraciflua L. Upon release as 4th instars, larvae were free to roam within arenas, where their location was recorded several times per day until all had pupated. The number of larvae on a particular host species was highly dependent on larval age. After release into experimlintal arenas, there was nearly unidirectional movement from loblolly pine to sweetgum, resulting in 75% of larvae being found on this host after 4 d. Sweetgum remained the preferred host for most of the larval stage; however, as larvae neared pupation there was strong movement to loblolly pine, which was preferred over sweetgum ˜3 to 1 for pupation. The initial host of release had no effect on larval host-choice for pupation. Host sequence, defined by host of release and host of pupation, affected larval duration and pupal weight only in the following cases. Insects that began and pupated on loblolly pine developed at a slower rate and weighed less than those that began and pupated on sweetgum. Individuals that switched hosts for pupation generally were not significantly different (in pupal weight or development time) from either of these. Implications of the observed pattern of host use, especially the overwhelming choice of loblolly pine for pupation, on gypsy moth interactions with natural enemies in the southeastern United States are discussed.

To assess the extent of inhibitory activity of the host compound 4-allylanisole, we conducted field studies with three scolytid species. These species are geographically widespread and economically important. Trials were completed with Dendroctonus brevicomis LeConte (California), D. ponderosae Hopkins (Oregon), and Ips pini (Say) (Wisconsin) by using multiple-funnel traps with appropriate pheromone-based attractants. With the Dendroctonus species, the effects of 4-allylanisole were compared with verbenone, an aggregation inhibitor produced by beetles themselves. We also determined effects of the treatments on the most abundant coleopterous predators in each trial. Inhibition of bark beetle aggregation behavior by 4-allylanisole was demonstrated for D. ponderosae (Oregon) and I. pini (Wisconsin). In Oregon, 4-allylanisole reduced the catch of D. ponderosae at attractant-baited traps by 77%, whereas verbenone reduced the catch by 91% compared with attractant alone. Although both reductions were significant, the effect of verbenone was significantly greater than that of 4-allylanisole. In Wisconsin, addition of 4-allylanisole to attractant-baited traps resulted in a significant reduction (43%) in numbers of I. pini caught, compared with attractant alone. In the California trials, mean trap catches of D. brevicomis were reduced by both 4-allylanisole (35%) and verbenone (27%) compared with attractant alone, but neither reduction was significant. Sex ratios of target scolytids were not affected by inhibitory treatments in any trial. The predator Temnochila chlorodia (Mannerheim) (Coleoptera: Trogositidae) was not affected by 4-allylanisole in California; however, verbenone significantly reduced the number caught. Although captures were low, numbers of T. chlorodia caught by traps containing 4-allylanisole in Oregon were significantly higher than those containing verbenone or attractant alone (numbers in verbenone and attractant traps were not significantly different). Numbers of the predatory beetles counted in Wisconsin-Thanasimus dubius (F.) (Coleoptera: Cleridae), Platysoma parallelum Say (Coleoptera: Histeridae), and P. (Cylistix) cylindrical (Paykull) (Coleoptera: Histeridae)-were not affected by elution of 4-allylanisole with the attractant. Implications of these results for protection of individual trees and management of bark beetle populations are discussed.