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J L Lyon

Publications and source records attributed to J L Lyon.

At least 55 records · Page 3Linked to original sources
PubMed1990

Cohort study of thyroid disease near the Nevada Test Site: a preliminary report.

The atmospheric testing of nuclear weapons in Nevada beginning in 1951 resulted in exposure of regions surrounding the Nevada Test Site (NTS) to fallout. A cohort of children born between 1947 and 1954 in two counties near the NTS, one in Utah and one in Nevada (UT/NV), were examined in 1965-1968 for thyroid abnormalities that might have been a result of exposure to radioiodine in fallout. The prevalence of thyroid abnormalities in these children (11-18 y) was compared to that in a control group selected from a county in Arizona (AZ) that was presumed to have received little or no fallout from the NTS. Thyroid nodules were found in 76 of the 4,819 children examined (15.8/1000). Of the 76 thyroid nodules, 22 were diagnosed as neoplasms. The rate of thyroid neoplasms among the UT/NV subjects was higher (5.6/1000) than among the AZ subjects (3.3/1000) (RR = 1.7), but because the number of neoplasms was small, the difference was statistically insignificant. In 1985-1986, 3,122 of the original study subjects were reexamined. In this reexamination, thyroid nodules were found in 125 individuals (44.2/1000). Of the 125 thyroid nodules detected during this later study period, 65 were considered to be thyroid neoplasms. Rates of thyroid neoplasms in UT/NV (24.6/1000) are again slightly higher than in AZ (20.2/1000) (RR = 1.2), but the difference is not significant (p = 0.65). Based on the rates of thyroid neoplasms in the two geographic locations, we conclude that living near the NTS in the 1950s has not resulted in a statistically significant increase of thyroid neoplasms in subjects from UT/NV when compared with subjects of the same age and gender living in AZ.

Adolescent↗
PubMed1989

Infectious and noninfectious exposures in the etiology of light chain myeloma: a case-control study.

Sixty-nine subjects with light chain myeloma were interviewed in a multicenter case-control study, and their responses were compared to those of 1683 controls selected from the general population of the same geographic areas. The interview was directed at the subject's history of exposure to a variety of chemical and infectious agents. Persons with a history of a medical implant had 2.2 times the risk of other persons (95% confidence interval = 0.9-5.8), a relative risk that increased with increasing time that the implant had been present. Alkali exposure that was deemed by the subject to be unusually heavy was associated with a relative risk of light chain myeloma of 7.8 (95% confidence interval = 1.7-35.3), while similarly defined exposure to carbon monoxide increased the risk by 6.1 times (95% confidence interval = 2.0-18.2). These findings differ from those obtained in our study of the more common forms of multiple myeloma and, while the differences are plausibly due only to chance given the large number of exposures investigated, they could be an indication that light chain myeloma is an etiologically distinct entity.

Bacterial Infections↗
PubMed1989

Uncertainty in the diagnosis of histologically confirmed pancreatic cancer cases.

In doing a case-control study of cancer of the exocrine pancreas, a set of criteria was developed to classify cancer of the exocrine pancreas by pathological and diagnostic data as to the probability that the tumor arose in the pancreas. We applied these criteria to the records of 125 consecutive patients between the ages of 40-79 years who were identified as having adenocarcinomas of the exocrine pancreas from a population-based cancer registry. We found that histological confirmation by a cancer registry does not guarantee the site of origin is the pancreas. Of the histologically confirmed cases meeting our study criteria, 28.7% may not have arisen in the pancreas. Forty-seven per cent of non-histologically confirmed cases, which most studies exclude, were almost certainly of pancreatic origin based on computerized tomogram (CT) scan and/or surgical palpation and subsequent clinical course. These figures may underestimate the full extent of diagnostic misclassification, especially in older age groups. We conclude that epidemiological studies of cancer of the exocrine pancreas need more uniform criteria for defining cases, and these criteria should take into account uncertainty as to site of origin. Sufficient detail of our scheme is presented so it can be applied in other studies.

Adult↗
PubMed1989

Diet and survival of patients with colon cancer in Utah: is there an association?

The extent to which diet influenced colon cancer survival was examined in 411 colon cancer cases identified in Utah between 1976 and 1981 using data from two population based case-control studies. After adjustment by proportional hazards regression models for the effects of tumour stage, age, sex, and religion, the hazard rate ratios (HRR) comparing highest to lowest quartile of intake for total calories, fat and protein were 0.60, 0.81 and 0.66 respectively, with the effect of calories being greatest for short-term survival (less than or equal to 24 months), HRR = 0.49. By contrast, the highest quartile of dietary fibre intake was associated with decreased survival (HRR = 1.53) when compared with the lowest quartile. More extensive studies are needed to verify these findings and to identify mechanisms underlying these associations.

Adult↗
PubMed1989

Association of obesity and ovarian cancer in a case-control study.

Data from a population-based case-control study conducted in Washington State and Utah were used to assess whether obesity is associated with an altered risk of epithelial ovarian cancer. Quetelet index, defined as weight (kg) at age 30 years divided by height (m) squared, was calculated for each woman, and the values for all subjects were divided into five categories of approximately equal size. Compared with women in the lowest category, women in the highest category had an odds ratio of 1.7 (95 per cent CI 1.1-2.7). Risks for women in the three intermediate Quetelet index categories also exceeded the risk for women in the lowest group, but to a much smaller degree. Among women with serous tumors, those in the highest Quetelet index category were at a greater than twofold excess risk (OR = 2.2, 95 per cent CI 1.1-4.2), but the risk was not increased in the intermediate categories. For endometrioid tumors, risk increased consistently with increasing Quetelet index, and the odds ratio in the highest category was 4.7 (95 per cent CI 1.0-22.7). For both serous and endometrioid tumors, the excess risk was largely confined to premenopausal women. The results of this analysis suggest that for at least some types of ovarian tumor, obesity may warrant further attention as a possible etiologic factor.

Adult↗
PubMed1989

Dietary intake and colon cancer: sex- and anatomic site-specific associations.

A case-control study was conducted in Utah between July 1979 and June 1983 in which 231 cases of colon cancer identified through the Utah Cancer Registry and 391 controls identified through random digit dialing were interviewed. Odds ratios (OR) were calculated comparing the highest exposure categories with the lowest exposure categories. The highest quintile of body mass index (weight (kg)/height (m)2 for males; weight (kg)/height (m)1.5 for females) was associated with increased risk in both males (OR = 2.1) and females (OR = 2.3). In females, total dietary fat (OR = 1.9) and energy intake (OR = 1.5) were associated with an increased colon cancer risk after adjusting for age, body mass index, and crude fiber. Fiber was protective in females (OR = 0.5) after adjusting for age, body mass index, and energy intake, as was beta-carotene (OR = 0.5) after also adjusting for crude fiber. Adjusted risk estimates in males were 2.0 for total dietary fat, 3.8 for polyunsaturated fat, 2.1 for monounsaturated fat, 2.1 for energy intake, 2.5 for protein, 0.3 for fiber, 0.4 for beta-carotene, and 0.3 for cruciferous vegetables. Risk estimates differed by site of cancer within the colon. In males, protein (OR = 3.8) was a risk factor for cancer of the descending colon, while fats (OR = 2.7-8.8) increased the risk of cancer of the ascending colon. The hypotheses that dietary fat increases colon cancer risk while dietary fiber decreases colon cancer risk and that fat and protein may be independently associated with colon cancer risk are supported.

Aged↗
PubMed1989

Chronic lymphocytic leukemia in relation to chemical exposures.

As part of a population-based case-control study carried out in four areas of the United States, 427 cases of chronic lymphocytic leukemia diagnosed between July 1, 1977, and December 31, 1981, and 1,683 controls were interviewed regarding their history of chemical exposure. Respondents were asked if they had ever been "highly exposed" at home, at work, or elsewhere to one or more of a list of chemicals or to any other such substances not on the list. These chemicals were categorized into 20 exposure groups based on chemical composition. Odds ratios were calculated adjusting for age, sex, race, education level, and geographic location by means of unconditional logistic regression. Increased risks were associated with reported past exposure to acid-containing chemicals, "other caustic substances," aliphatic hydrocarbons, and chlorinated hydrocarbons. Because of the large number of exposures investigated in this study, and because of the relatively imprecise means the authors had to assess exposure, further research is needed to verify these findings.

Adult↗
PubMed1988

B cell neoplasms and occupational asbestos exposure.

To evaluate the etiologic role of asbestos exposure in B cell neoplasms, we compared the estimated level of occupational exposure to asbestos of cases with chronic lymphocytic leukemia (CLL; N = 429) and multiple myeloma (MM; N = 698) with that of controls (N = 1,683). Cases were identified through four population-based cancer registries in the U.S. and controls were randomly selected from the same geographic areas. Exposure to asbestos was assessed by classifying each job held by a subject into one of four categories, based on the estimated intensity of exposure to asbestos. Evidence was found for a modest increasing risk of CLL with increasing asbestos exposure. Relative to persons with no known occupational exposure to asbestos, the risk for CLL was 1.1 (95% confidence interval (CI) = 0.8-1.6) for low, 1.2 (CI = 0.8-1.8) for medium, and 1.4 (CI = 0.8-2.3) for high peak asbestos exposure (p value for trend = 0.13). The association was strongest in white study subjects and in those individuals exposed 10 to 19 years prior to the interview. No association was observed between MM and occupational exposure to asbestos in the entire study population or within specific subgroups. Given the pattern of immunologic abnormalities that occur with increased frequency in asbestos-exposed persons, our observation of an association between occupational asbestos exposure and CLL deserves attention in subsequent studies.

Aged↗
PubMed1988

Fried foods and the risk of colon cancer.

High-temperature cooking of foods produces a variety of mutagenic substances. Because of the association of such substances with carcinogenesis, the authors used a case-control study of colon cancer conducted in Utah between 1977 and 1979 with 246 cases and 484 controls to test the hypothesis that persons with colon cancer would report more frequent use of fried and broiled meats. Intake of food was measured by a food frequency questionnaire which focused on food use five years before the interview. For men, the odds ratios for the highest level of use were 1.2 (90% confidence interval (CI): 0.8-1.9) for fried meats and 0.7 (90% CI: 0.5-1.0) for broiled meats; for women, the odds ratios were 1.3 (90% CI: 0.8-2.1) for fried meats and 1.1 (90% CI: 0.7-1.7) for broiled meats. The reported use of fried and broiled vegetables was too infrequent to permit evaluation. The authors conclude that the ingestion of fried and broiled meats five years before diagnosis of colon cancer had little influence on the development of this cancer.

Adult↗
PubMed1987

Antigenic stimulation and the occurrence of multiple myeloma.

To evaluate whether potent or prolonged stimulation of the immune system increases the risk of multiple myeloma, the authors compared 698 myeloma cases which occurred between July 1, 1977 and June 30, 1981 in four geographic areas of the United States with 1,683 demographically similar controls from the same areas. Cases and controls were interviewed about past exposures which may have involved antigenic challenge. Although few positive associations emerged, those most consistent with the immune stimulation hypothesis were modest associations between myeloma and a history of rheumatic fever (relative risk (RR) = 1.74, 95% confidence interval (CI) = 1.09-2.77) and between myeloma and urinary tract infection (RR = 1.30, 95% CI = 1.00-1.69, when self-respondent cases were compared with controls). Little association was found between the risk of myeloma and the number of past viral illnesses, number of bacterial illnesses, or number of allergy desensitization injections. Myeloma risk was found to be inversely related to the number of diseases against which a subject reported having been immunized, perhaps because of differences in socioeconomic status between cases and controls. These findings provide little support for the immune system stimulation hypothesis of myeloma etiology, but because of the limitations of interview techniques for assessing antigen exposure, further studies using laboratory methods may be warranted.

Aged↗
PubMed1987

Energy intake: its relationship to colon cancer risk.

A case-control study was conducted to assess the role of diet in the etiology of colon cancer. Diet was measured by means of a comprehensive quantifiable food frequency history instrument in 246 cases and 484 controls drawn from the general population of Utah. Each subject's diet was described by major nutrient groups and total energy based on the nutritional content of foods reported. Cases reported higher daily food intake 5 years preceding diagnosis than controls [men, rate ratio (RR) = 2.5; women, RR = 3.6], as measured by total energy content of the diet. Higher risk of colon cancer with increasing energy intake was independent of stage of disease at diagnosis and obesity, as measured by body mass. Fat, protein, and carbohydrate intake all had elevated RRs but could not be assessed as risk factors independent of energy intake because of their strong correlations with total calories. Due to the higher energy intake of the cases, odds ratios for the daily intake of dietary fiber and vitamins A and C were also greater than 1. However, adjusting for caloric intake removed this effect, and dietary fiber showed a weak protective effect. Total energy intake must be evaluated before attempting to assign a causal role to any food or nutrient that may be postulated to play a role in colon cancer.

Adult↗
PubMed1986

Structural requirements for the binding of phenylglycosides to the surface of protoplasts.

A variety of phenylglycosides have been synthesized and tested for binding to the surface of protoplasts from suspension-cultured cells of "Paul's Scarlet" rose (Rosa sp.). Multivalent phenylglycosides in the form of Yariv antigens (1,3,5,-tri-[p-glycosyloxyphenylazo]-2,4,6,-trihydroxybenzene) agglutinated the protoplasts. Fluorescence-labeled derivatives of other monovalent and polyvalent phenyl-beta-glycosides did not bind to the protoplast surface. Agglutination was induced by Yariv antigens only if these probes contained beta-anomeric, O-glycosidic linkages. Yariv antigens containing alpha-anomeric or thio-glycosidic linkages did not agglutinate protoplasts. These same structural features of Yariv antigens were also required for the precipitation of gum arabic-Yariv antigen complexes. The results suggest that plasma membranes of "Paul's Scarlet" rose protoplasts contain arabinogalactan-proteins that interact with phenyl-beta-glycosides. The results further show that binding at these plasma membrane sites is not solely dependent upon the carbohydrate portion of single phenylglycosides, but may also require specific spatial orientations of adjacent phenylglycosides.

Journal Article↗
PubMed1986

Toxic substance exposure and multiple myeloma: a case-control study.

By means of a population-based, multicenter case-control investigation, certain toxic substances were evaluated as risk factors for multiple myeloma. Interviews were completed on 698 subjects with newly diagnosed multiple myeloma, and 1,683 controls were selected from the same geographic areas as those of the cases. Respondents were asked if they had ever been "highly" exposed" to one or more of a list of toxic substances or to other substances not on the list. With the aid of a toxicologist, responses were then categorized into 20 exposure groups. Those who reported past exposure to pesticides had an estimated relative risk of 2.6 for multiple myeloma [95% confidence interval (CI) = 1.5-4.6]. Subjects exposed to a variety of compounds commonly used by painters had an estimated relative risk of 1.6 (95% CI = 1.1-2.4). An increased risk also was found for those who were exposed to sources of carbon monoxide (relative risk = 1.8, 95% CI = 1.0-3.2). Associations of borderline statistical significance were found for metals and organically high polymers (plastics and elastomers). No statistically significant associations were seen for exposure to fertilizers; dyes and inks; alkalies; acids; other caustic substances; chemical asphyxiants; aliphatic, chlorinated, or aromatic hydrocarbons; aldehydes and ketones; ethers; esters; oils; dusts; or asbestos.

Adult↗
PubMed1985

Mortality among New Zealand Maori and non-Maori Mormons.

Mortality rates for New Zealand Maori and non-Maori Mormons in the period 1970-77 have been compared with those for non-Mormons in the census year 1976 to measure the impact of the Mormon lifestyle on differences in mortality between Maoris and non-Maoris. Maori mortality was much lower among Mormons than non-Mormons suggesting that environmental, rather than genetic factors, play a predominant role in the relatively high overall Maori mortality. However the prevalence of smoking among Maori Mormons was not much lower than for the general Maori population. Reasons for the relative mortality advantage of Maori Mormons were therefore not clear, although attitudes to health and health services utilization, and the influence of strong social support networks, might be involved. Paradoxically, non-Maori Mormon mortality rates were similar to those for non-Mormons. A combination of factors appeared to contribute to this finding including the fact that 26% of non-Maori Mormons were of Pacific Island origin, non-Maori Mormons were of lower socioeconomic status than other non-Maoris, and part Maoris probably constitute a high, but unknown, proportion of Mormons classified as non-Maoris.

Adolescent↗