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Biomedical subjects

R L Phillips

Publications and source records attributed to R L Phillips.

At least 109 records · Page 6Linked to original sources
PubMed1989

Cohort study of diet, lifestyle, and prostate cancer in Adventist men.

Dietary and lifestyle characteristics were evaluated in relation to subsequent prostatic cancer risk in a cohort of approximately 14,000 Seventh-day Adventist men who completed a detailed lifestyle questionnaire in 1976 and who were monitored for cancer incidence until the end of 1982. During the 6-year follow-up period, 180 histologically confirmed prostatic cancers were detected among some 78,000 man-years of follow-up. Increasing educational attainment was associated with significantly decreased risk of prostate cancer in this study; age at first marriage was also inversely associated with risk, although this was not significant. There was no relationship between body mass index (as measured by Quetelet's Index) and risk. A history of prostate "trouble" was associated with a 60% increase in risk which was highly significant. Although there were suggestive relationships between increasing animal product consumption and increased risk, these results did not persist after accounting for the influence of fruit and vegetable consumption. Nor was exposure to the vegetarian lifestyle during the childhood years associated with alterations in subsequent risk. However, increasing consumption of beans, lentils and peas, tomatoes, raisin, dates, and other dried fruit were all associated with significantly decreased prostate cancer risk.

Adult↗
PubMed1989

Risk factors for tumors of the brain and cranial meninges in Seventh-Day Adventists.

We studied the occurrence of tumors of the brain and cranial meninges in a cohort of 34,000 California Seventh-Day Adventists who completed a detailed life-style questionnaire in 1976 and who were followed for cancer incidence until the end of 1982. During the period of follow-up, 31 tumors were diagnosed in the cohort (21 gliomas, 10 meningiomas). Increased risk for glioma was associated with rural residence, history of a positive tuberculosis skin test and consumption of pork products; increased meningioma risk was associated with a positive reaction to a tuberculosis skin test, previous stroke, use of tranquillizers and a vegetarian life-style in childhood.

Adult↗
PubMed1989

Is early natural menopause a biologic marker of health and aging?

The relation between age at natural menopause and all-cause mortality was investigated in a sample of 5,287 White women, ages 55 to 100 years, naturally-postmenopausal, Seventh-day Adventists who had completed mailed questionnaires in 1976. The age-adjusted odds ratio of death during 1976-82 in women with natural menopause before age 40 was 1.95 (95% confidence interval = 1.24, 3.07), compared to the reference group of women reporting natural menopause at ages 50 to 54. Corresponding odds ratios of death were 1.39 (95% CI = 1.06, 1.81) for natural menopause at ages 40 to 44, and 1.03 (95% CI = 0.84, 1.25) for natural menopause at ages 45 to 49. Among 3,166 White, 55- to 100-year-old, surgically-postmenopausal, Adventist women, there was no relation between age at surgical menopause and mortality. Logistic regression analyses indicated that findings from this study were apparently not due to confounding by smoking, over- or underweight, reproductive history, or replacement estrogen use.

Adult↗
PubMed1988

Dietary habits and past medical history as related to fatal pancreas cancer risk among Adventists.

Epidemiologic studies of diet and pancreas cancer are few, and include ecologic comparisons and a limited number of prospective and case-control studies. Foods and/or nutrients that have been suggested to be associated with increased risk of this cancer include total fat intake, eggs, animal protein, sugar, meat, coffee and butter. Consumption of raw fruits and vegetables has been consistently associated with decreased risk. Dietary habits and medical history variables were evaluated in a prospective study of fatal pancreas cancer among 34,000 California Seventh-day Adventists between 1976 and 1983. Forty deaths from pancreas cancer occurred during the follow-up period. Compared to all US whites, Adventists experienced decreased risk from pancreas cancer death (standardized mortality ratio [SMR] = 72 for men; 90 for women), which was not statistically significant. Although there was a suggestive relationship between increasing meat, egg, and coffee consumption and increased pancreatic cancer risk, these variables were not significantly related to risk after controlling for cigarette smoking. However, increasing consumption of vegetarian protein products, beans, lentils, and peas as well as dried fruit was associated with highly significant protective relationships to pancreas cancer risk. A prior history of diabetes was associated with increased risk of subsequent fatal pancreas cancer, as was a history of surgery for peptic or duodenal ulcer. A history of tonsillectomy was associated with a slight, nonsignificant protective relationship as was history of various allergic reactions. These findings suggest that the protective relationships associated with frequent consumption of vegetables and fruits high in protease-inhibitor content are more important than any increase in pancreas cancer risk attendant on frequent consumption of meat or other animal products. Furthermore, the previously reported positive associations between diabetes and abdominal surgery and pancreas cancer risk are supported in these data.

Adult↗
PubMed1988

Animal product consumption and subsequent fatal breast cancer risk among Seventh-day Adventists.

Seventh-day Adventist women experience lower mortality rates from breast cancer than other white females in the United States. To evaluate the role of diet in relation to breast cancer within this unique population (more than one-half of all Adventist women are lacto-ovo-vegetarians), a nested case-control study was conducted including 142 cases of fatal breast cancer and 852 matched controls among California Seventh-day Adventist women in 1960-1980. No significant relations between the consumption of animal products (meat, milk, cheese, and eggs) and breast cancer were evident. Odds ratios of 1.00, 1.22, and 1.03 were observed for meat consumption categories of none or occasional, 1-3 days/week, and 4+ days/week, respectively. However, among those women who experienced a relatively early age at natural menopause (less than or equal to 48 years), a suggestive though nonsignificant, positive association between meat consumption and risk was noted. These relations remained unchanged after simultaneously controlling for the effects of other covariates (menstrual characteristics and obesity) via conditional logistic regression analysis. Risk was not related to age at first exposure to the vegetarian lifestyle nor to duration of exposure to the vegetarian lifestyle.

Adult↗
PubMed1987

Factors affecting survival of children with malignant gliomas.

Fourty-four patients (23 male and 21 female, aged 2 to 20 years (mean, 9.6], harboring pathologically proven malignant glioma (Grades III and IV) were treated between 1976 and 1985. Tumor sites included the cerebral hemisphere (26 patients), thalamus (6 cases), brain stem (7 cases), and the cerebellum (5 cases). All patients underwent operation and initial treatment with steroids. Irradiation was given in 35 patients; 3 had adjuvant chemotherapy. At the time of study, 22 were deceased. The longest period of follow-up was 65 months. Survival curves were calculated from the date of the first visit to the date of the last evaluation or death. The mean survival times were 30 months for all patients, 14 months for cerebellar cases, 17 months for brain stem cases, 26 months for thalamic cases, and 33 months for cerebral hemisphere cases. However, the differences between mean survival times were not statistically significant. The patient's age was the single most significant factor, with those 5 to 10 years old having the worst survival curve (P = 0.0036). Irradiation was associated with an improved mean survival time (34 vs. 19 months); however, this was not statistically significant (P = 0.15). Girls had shorter mean survival times than boys (16.5 vs. 37 months, P = 0.0511). Otherwise, there was no clinical or radiological factor that indicated a better prognosis. This was also confirmed by chi 2 analyses comparing 72 factors between patients with more than 24 months of survival and those with less than 24 months of survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

The structure of the maize ribosomal DNA spacer region.

A combination of a single stranded plasmid vector and ordered deletions were used to determine the complete nucleotide sequence of a rDNA spacer region isolated from the DNA of maize Black Mexican Sweet suspension cells. The sequence reveals the presence of ten "200 base" subrepeats within the maize rDNA spacer region. By S1 protection experiments we have tentatively determined that the start of maize rRNA transcription is 144 bases 3' of the end of the last spacer subrepeat. We propose that the spacer subrepeats may have an important role in regulating maize rRNA transcription.

Base Sequence↗
PubMed1986

Fast neutron r.b.e. for lethality and genotoxicity in a wild-type and a repair-deficient strain of yeast.

The relative biological effectiveness (r.b.e.) of cyclotron-produced fast neutrons (11 MeV) in relation to 60Co gamma-rays, was studied in a wild-type and a DNA repair-deficient yeast strain for cell killing and genotoxicity. In the wild-type (D7) strain the r.b.e. varied from 2.7 to 4.1 for lethality, 2.8 to 7.1 for reverse mutation and 3.5 to 7.8 for mitotic gene conversion. At different survival levels, the repair deficient strain (D7 rad 52/rad 52) generally showed a lower r.b.e. for both cell killing and genotoxicity (25.2 to 37.2 per cent reduction for the cell death and 24.8 to 70.6 per cent for mutation and gene conversion) compared to the wild type. Except at very low dose levels, the r.b.e. values for cell killing and genotoxicity were similar within a given strain. At similar survival levels, neutrons were no more genotoxic than gamma-rays.

Cell Survival↗
PubMed1985

Carcinoma of the nasopharynx: survival and patterns of recurrence.

We have analyzed survival, disease-free (NED) survival, and patterns of recurrence for 76 patients with carcinoma of the nasopharynx treated from June 1964 through July 1979. Patients with Stages I through IV, who were treated for cure, comprise the study group. Megavoltage teletherapy treatment was delivered to the primary bilateral neck and supraclavicular areas. Dose to the nasopharynx ranged from less than 55 Gy to 70 Gy with several patients receiving higher doses. The observed 5 year NED survival rates were: Stage I, 75%; Stage II, 20%; Stage III, 42%; and Stage IV, 31%. During a 5-year minimum follow-up for all patients, 46 or 60.5% failed. Ninety-five percent of these failures occurred within 3 years; only two patients relapsed after more than 5 years.

Adolescent↗
PubMed1985

DNA amplification patterns in maize endosperm nuclei during kernel development.

Increased DNA levels in centrally located endosperm nuclei are shown to be related to endosperm development in Zea mays. Mitotic activity sharply decreases in endosperm cells 10-12 days after pollination. At this time nuclear size and DNA content per nucleus (where C = haploid content) sharply increase until peak levels are reached at about 14-18 days after pollination. Mean DNA content per endosperm nucleus in strain A188 was shown by Feulgen cytophotometry to increase to about 90C by this peak stage, with the pattern being remarkably consistent over four consecutive growing seasons. Some individual nuclei achieved levels of >200C. Most other strains compared during one growing season averaged even higher peak levels of DNA per nucleus than did A188. Individual nuclei in those strains reached levels as high as 690C. A decrease in DNA level was observed in older endosperms with most strains. Endosperm mutant strains did not show a significant reduction in DNA. Opaque-2 mutants in several backgrounds achieved higher levels of DNA per nucleus. DNA levels from F(1) endosperms did not indicate heterosis. Regardless of differences in DNA content, the pattern of DNA increasing as development proceeds followed by a DNA decrease was observed for most strains. Cytological studies reveal much variation in chromatin strandedness, a maximum of three nucleoli, a maximum of three nucleolar organizer regions, and approximately 30 diffuse chromatin masses in older endosperm tissue. A form of DNA amplification, perhaps polytenization, appears to be occurring during endosperm development.

Journal Article↗
PubMed1985

A strategy for interunit problem solving.

The complexities of today's nursing unit, and especially the ICU, require greater interunit cooperation than ever before. As the complexity of the ICU structure increases, so does the potential for interunit conflict and organizational strain.

California↗
PubMed1985

Does a vegetarian diet reduce the occurrence of diabetes?

We propose the hypothesis that a vegetarian diet reduces the risk of developing diabetes. Findings that have generated this hypothesis are from a population of 25,698 adult White Seventh-day Adventists identified in 1960. During 21 years of follow-up, the risk of diabetes as an underlying cause of death in Adventists was approximately one-half the risk for all US Whites. Within the male Adventist population, vegetarians had a substantially lower risk than non-vegetarians of diabetes as an underlying or contributing cause of death. Within both the male and female Adventist populations, the prevalence of self-reported diabetes also was lower in vegetarians than in non-vegetarians. The associations observed between diabetes and meat consumption were apparently not due to confounding by over- or under-weight, other selected dietary factors, or physical activity. All of the associations between meat consumption and diabetes were stronger in males than in females.

Adult↗
PubMed1985

Dietary relationships with fatal colorectal cancer among Seventh-Day Adventists.

Associations between fatal colon or colorectal cancer and frequency of use of meat, cheese, milk, eggs, green salad, and coffee, as well as percent desirable weight, are described with the use of 21 years of follow-up for 25,493 white California Seventh-Day Adventists. Associations are presented in terms of relative risk (RR) of colorectal cancer for heavy or light exposure versus rare exposure. There were no clear relationships evident between colon or rectal cancer and meat, cheese, milk, or green salad use. Egg use was positively associated with risk of fatal colon cancer in both males (RR = 1.6) and females (RR = 1.7). Coffee use was positively associated with both colon and rectal cancer mortality in males and females, particularly for colon cancer during the last 11 years of follow-up (male RR = 3.5; female RR = 1.9). Overweight (percent of desirable weight greater than or equal to 125) was associated with an increased risk of fatal rectal cancer in both sexes combined (RR = 2.8) and colon cancer in males only (RR = 3.3). Furthermore, eggs, coffee, and overweight appear to be independently associated with risk of both colon and colorectal cancer. These three factors may explain a substantial portion of the colorectal cancer mortality differential between Adventists and U.S. whites (62% for males; 30% for females).

Adult↗
PubMed1984

Ribosomal RNA contents of maize genotypes with different ribosomal RNA gene numbers.

Ribosomal RNA (rRNA) contents were determined in 16 maize genotypes whose individual rRNA gene numbers varied from 5000 to 23,000 per 2C nucleus. Analytical polyacrylamide gel electrophoresis of total RNA showed that no obvious relation existed between rRNA gene number and rRNA content. Only two of nine common inbred lines contained more rRNA than W-23, the inbred with the lowest rRNA gene number. Two of four lines with altered protein content (due to long-term experimental selection) had rRNA contents significantly reduced from those of W-23. A line with an apparent duplication of the nucleolus organizer region of chromosome 6 (called 2-NOR) was expected to possess an elevated quantity of rRNA because it possesses a larger nucleolus; however, we produced a 2-NOR isogenic version and found no difference in rRNA content. The rRNA genes in maize are distributed throughout the NOR-heterochromatin and the NOR-secondary constriction portions of the NOR. The absence of an obvious correlation between rRNA gene number and cellular rRNA content may reflect the presence of a large number of rRNA genes in an inactive state, at least during the stage of growth examined in these experiments.

Gene Expression Regulation↗