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Biomedical subjects

J L Lyon

Publications and source records attributed to J L Lyon.

At least 91 records · Page 5Linked to original sources
PubMed1981

Citrus Tissue Culture : AUXINS IN RELATION TO ABSCISSION IN EXCISED PISTILS.

An in vitro bioassay for chemicals that affect Citrus abscission was used to identify three inhibitors of stylar abscission in lemon pistil explants incubated on defined nutrient media. The three inhibitors (picloram, 4-chlorophenoxyacetic acid, and 3,5,6-trichloropyridine-2-oxyacetic acid) are all auxins, and the most potent of them (i.e. picloram) was found to be at least 10 times more active in the bioassay than 2,4-dichlorophenoxyacetic acid. Picloram (2 micromolar) also was shown to be effective in inhibiting stylar abscission in pistil explants from other Citrus cultivars such as mandarin, Valencia, and Washington navel oranges and grapefruit. To study the physiology of auxins active as abscission inhibitors versus inactive auxins in lemon pistils, the transport and metabolism of [1-(14)C]-2,4-dichlorophenoxyacetic acid was compared with that of [2-(14)C]indole-3-acetic acid, which is without effect in the bioassay over the range from 0.1-100 micromolar. Insignificant quantities of labeled indole-3-acetic acid and/or labeled derivatives were found to reach the presumptive zone of stylar abscission under the test conditions. Labeled 2,4-dichlorophenoxyacetic acid and/or labeled derivatives also were transported slowly through pistils, but some radioactivity could be detected in the stylar abscission zone as early as 24 hours after the start of incubation. Extensive conversion of [2-(14)C]indole-3-acetic acid to labeled compounds tentatively considered to be glycoside and cellulosic glucan derivatives was found with the use of solvent extraction methodology. A significantly smaller percentage of the radioactivity in pistils incubated on [1-(14)C]-2,4-dichlorophenoxyacetic acid was found in fractions corresponding to these derivatives. Both transport and metabolism appear to be important factors affecting the activity of auxins as abscission inhibitors in the bioassay.

Journal Article↗
PubMed1980

Breast cancer and reproductive history from genealogical data.

With the use of data from the Utah State Cancer Registry and Utah genealogical data, an analysis of 236 breast cancer patients and 937 controls matched on year of birth showed that a late age at the birth of the first child was most strongly associated with incidence of breast cancer (relative odds = 2.0; P less than 0.001). A strong interaction was found between age at first delivery (AFD) and age at last delivery (ALD). The association of AFD with breast cancer incidence was strongest for women with an ALD before 35 years of age even after adjustment for partly (relative odds = 4.1; P less than 0.001). Decreased parity was not significantly associated with breast cancer.

Adult↗
PubMed1980

Cancer incidence in Mormons and non-Mormons in Utah during 1967--75.

Data from the Utah Cancer Registry were used to compare cancer incidence in Mormons and non-Mormons in Utah for the period 1967--75. Church membership was identified for 97.8% of the 20,379 cases in Utah by a search of the central membership files of the Church of Jesus Christ of Latter-Day Saints (or Mormon Church). Sites associated with smoking (lung, larynx, pharynx, oral cavity, esophagus, and urinary bladder) showed an incidence in Mormons at about one-half that of non-Mormons. Rates of cancers of the breast, cervix, and ovary were low in Mormon women; the rate for cervical cancer was about one-half of that observed in non-Mormons. Cancers of the stomach, colon-rectum, and pancreas were about one-third lower in Mormons than in others who are not members of this religious group. Most of the differences seen in cancer incidence can be explained by Mormon teachings regarding sexual activity and alcohol and tobacco use, but some differences (e.g., colon and stomach) remain unexplained.

Christianity↗
PubMed1980

Cancer risk factors: an analysis of Utah Mormons and non-Mormons.

In a comparison of Mormons and non-Mormons in Utah, more Mormon men and women married spouses of the same faith, were religiously active, were of Northern Europe ancestry, lived in rural areas, had fewer exposures to occupational hazards, were less likely to smoke cigarettes or drink coffee, tea, and alcohol, used fats in cooking, and were more often married that was the cohort of other religions. No differences existed in occupation, but Mormon men had completed more years of schooling. Mormon women were less likely to be college graduates, had fewer sexual partners, had more pregnancies, were older at first pregnancy, were less likely to use birth control pills, had fewer miscarriages and hysterectomies, examined their breasts more often, and had more breast X-rays. For women, there was only a small difference by religion for age at first intercourse and no difference for age at which they began using birth control pills. Religious activity was examined for Mormons, and in most instances inactive Mormons were more like the non-Mormon population in respect to the variables measured.

Adult↗
PubMed1980

Cancer in Utah: risk by religion and place of residence.

We compared cancer incidence during 1967--75 between Mormons and non-Mormons living in urban and rural areas of Utah. The non-Mormon urban men had a 34% higher risk of cancer compared with their rural counterparts. Most of this increase in risk occurred in sites associated with tobacco and for cancers of the stomach, colon, and prostate gland. Urban Mormon males had no significant increase in risk. The urban female population was at higher risk than was the rural regardless of religion. The increase was not as striking as that observed in non-Mormon men (8 vs. 34%); cancers of the respiratory and gastrointestinal tracts and female genitalia contributed to the elevated risk. We concluded that personal habits such as smoking and drinking and reproductive factors were possible explanations for the previously observed urban-rural gradients in cancer risk.

Adolescent↗
PubMed1979

Childhood leukemias associated with fallout from nuclear testing.

Continuing concern over the possible carcinogenic effects of low-level radiation prompted us to study the population of Utah because of its exposure to fallout from 26 nuclear tests between 1951 and 1958. Certain rural counties (high-fallout counties) received most of the fallout during that period. We reviewed all deaths from childhood (under 15 years of age) cancers occurring in the entire state between 1944 and 1975 and assigned them to a cohort of either high or low exposure, depending on whether 15 between 1951 and 1958. For reasons unknown, leukemia mortality among the low-exposure cohort in the high-fallout counties was about half that of the United States and the remainder of the state. Mortality increased by 2.44 times (95 per cent confidence, 1.18 to 5.02) to just slightly above that of the United States in the high-exposure cohort residing in the high-fallout counties, and was greatest in 10- to 14-year-old children. For other childhood cancers, no consistent pattern was found in relation to fallout exposure. The increase in leukemia deaths could be due to fallout or to some other unexplained factor.

Adolescent↗
PubMed1979

Mormon health.

Explore the source record for details and available documents.

Demography↗
PubMed1978

Gastric cancer in a coal mining region.

A significant excess incidence of gastric cancer was previously reported in the coal mining counties of Utah for 1965-1969. A repeat study for the period 1970-1975 showed the rates to be close to expectation and are in line with the slight excess mortality reported by Creagan et al. from United States coal mining counties. A cluster of 12 cases out of 43 reported for the 11-year period occurred in 1965. Cases during 1966-1975 appear to have occurred at random by year. The previous suggestion that the high incidence of gastric cancer in Carbon and Emery Counties could be related to frequent exposure to coal-carrying hydrocarbons appears to be unwarranted.

Adolescent↗
PubMed1978

Colon cancer in a low-risk population.

Data are presented on colon mortality in Utah. For the years 1950 to 1969, the state population had 34% fewer deaths from colon cancer than the average United States population. Colon cancer incidence was also studied for the years 1966 to 1970, both for the state and for a large subgroup (Mormons) who abstain from tobacco and alcohol for religious reasons; the colon cancer incidence of Mormons was 37% below the United States average, and that of non-Mormons was 18% below the United States average. A preliminary dietary survey found little difference in meat, fat, and fiber consumption between the population of Utah and that of the United States as a whole.

Christianity↗
PubMed1978

Cardiovascular mortality in Mormons and non-Mormons in Utah, 1969--1971.

Cardiovascular mortality in the State of Utah is among the lowest in the United States. The religion of 72% of the state residents (Mormon) proscribes the use of tobacco and alcohol; a large number of Mormons adhere to this proscription. This study analyzed the 6108 cardiovascular disease deaths between 1969--1971 in Utah of members in the Mormon Church. For both sexes, Mormons had 35% less mortality than expected from US rates for ischemic heart disease, while non-Mormons were not significantly different from US whites. These results support the relationship between cigarette smoking and mortality from cardiovascular disease. Mormon men also had lower mortality from hypertensive heart disease and Mormon women from rheumatic heart disease than non-Mormons in Utah.

Aged↗
PubMed1977

Low cancer incidence and mortality in Utah.

Utah cancer mortality for the years 1950-1969 and morbidity for the years 1966-1970 are reported. Utah had 18% fewer cases of cancer than expected based on the Third National Cancer Survey, and 24% fewer cancer deaths than expected based on national mortality data. Cancer sites associated with cigarette smoking and alcohol use accounted for nearly half of these differences. Several major sites not strongly associated with smoking showed lower incidence and mortality than expected. These included pancreas, colon, rectum, female breast, uterine cervix and ovary. A marked excess occurrence above expectation was observed for cancer of the lip. Some possible explanations of these findings are discussed, including some of the unique aspects of the Utah population.

Adolescent↗