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Biomedical subjects

M R Andersen

Publications and source records attributed to M R Andersen.

15 recordsLinked to original sources
PubMed1999

The direct antiatherogenic effect of estrogen is present, absent, or reversed, depending on the state of the arterial endothelium. A time course study in cholesterol-clamped rabbits.

BACKGROUND: This study further investigated the relationship between estrogen, arterial endothelium, and nitric oxide (NO) in cholesterol-clamped rabbits. METHODS AND RESULTS: Rabbits were ovariectomized, balloon-injured in the thoracic aorta, and grouped to receive cholesterol-enriched chow together with either 17beta-estradiol or vehicle for 1, 2, 4, or 8 weeks. In the undamaged aorta, cholesterol accumulation of the placebo rabbits was significantly increased from week 4 to 8 (P<0.001). This increase was almost completely inhibited by estrogen (P<0.001). In the balloon-injured aorta, the estrogen and placebo rabbits accumulated similar amounts of cholesterol in the reendothelialized areas. In the deendothelialized areas, the estrogen group surprisingly accumulated significantly more cholesterol than the placebo group. This difference was apparent from week 2 and became significant at week 8 (P<0.01). Circulating nitrite/nitrate were significantly increased by estrogen at weeks 1, 2, and 4 but not at week 8. Similarly, in additional experiments, basal NO release was significantly higher in estrogen-treated than in placebo-treated rabbits after 4 (P<0.05) but not after 8 weeks. Stimulated NO release and endothelial NO synthase activity did not differ between groups. Mononuclear-endothelial cell binding was reduced by 50% by estrogen after 4 weeks (P<0.05). This difference, however, was abolished by coadministration of N(G)-nitro-L-arginine methyl ester, an inhibitor of NO production. CONCLUSIONS: The direct antiatherogenic effect of estrogen was present, absent, or reversed, depending on the state of the arterial endothelium, and preceded by a transient increase in NO production followed by a reduced mononuclear-endothelial cell binding.

Analysis of Variance↗
PubMed1999

Prostate-specific antigen for prostate cancer screening. Do physician characteristics affect its use?

PURPOSE: Screening for prostate cancer with the prostate-specific antigen (PSA) test remains controversial. This controversy is reflected in a lack of consensus in the medical literature and among professional and policy organizations regarding routine screening by PSA. It is not known how physicians respond when recommendations from experts are inconsistent. METHODS: A questionnaire was mailed to 1369 primary care physicians in active practice in Washington State in 1994. Response rate to the survey was 63%. Chi-square tests and multivariate logistic regression analysis were used to examine the effects of physician characteristics on physicians' self report of use of the PSA test for screening asymptomatic male patients, aged 50 to 80, for prostate cancer. RESULTS: Of the 714 physicians included in the analysis, 68% reported routine use of PSA. Use of PSA varied among physicians on the basis of practice setting, years since medical school graduation, and whether compensation was fee-for-service or salaried. Male physicians trained before 1974 and physicians receiving fee-for-service were significantly more likely than other physicians to recommend screening by PSA. CONCLUSIONS: Results suggest that physicians' personal characteristics such as year of medical school graduation, gender, and mode of reimbursement are related to self-reported PSA use.

Chi-Square Distribution↗
PubMed1999

Community attitudes and mammography use: does it really matter what other people think?

This study examined whether community characteristics, particularly community attitudes regarding mammography use, are associated with women's use of mammography in rural communities. Forty communities in predominantly rural areas of Washington State were selected for inclusion in this study based on their size and distance from an urban center. Characteristics of the communities were assessed as were characteristics of women living in the communities. From each community, random samples of 352 women between 50 and 80 years old participated by completing a telephone survey that included questions on a variety of topics, including their use of mammography. Logistic regression analyses revealed community of residence to be a significant predictor of individual women's mammography use after adjusting for individual level predictors of mammography use including age, education, employment, marital status, financial situation, and ease of access to medical services. An examination of the influence of community characteristics revealed women living in communities with supportive community attitudes towards mammography use report higher levels of mammography use than do women living in communities with less supportive attitudes. The presence or absence of male or female physicians or of mammography facilities in a local community was not associated with statistically significant effects on women's mammography use. Community attitudes are associated with mammography use in rural communities. Public health interventions that change community attitudes may have effects that extend beyond the people directly contacted by these interventions.

Aged↗
PubMed1998

Quantification of multiple human cytochrome P450 mRNA molecules using competitive reverse transcriptase-PCR.

We developed a quantitative competitive reverse transcriptase-polymerase chain reaction (QC RT-PCR) assay to measure mRNA levels of seven human cytochrome P450 (P450, CYP) genes and microsomal epoxide hydrolase (EH) simultaneously. This assay employs an exogenous recombinant RNA (rcRNA) molecule as an internal standard that shares PCR primer and hybridization probe sequences with CYP1A1, CYP1A2, CYP2A6/7, CYP2D6, CYP2E1, CYP2F1, CYP3A4/5/7, and EH mRNA. Because each rcRNA molecule contains several primer sequences, an entire battery of genes that exhibit differential responsiveness to various classes of xenobiotics may be measured simultaneously from one population of cDNA molecules. In this study, we demonstrated the precision and power of the assay using small amounts of human liver total RNA. We also report for the first time quantitative profiles of P450 and EH mRNA abundance in eight human livers. Cytochrome P450 2E1 mRNA maintained the highest abundance (average 6.67 x 10(7) molecules/microg of total RNA) and least variation (13 fold) in all livers examined. Cytochrome P450 1A2, CYP2A6/7, CYP2D6, CYP3A4/5, and EH mRNAs were approximately one order of magnitude less abundant than CYP2E1 transcripts, with CYP2D6 levels exhibiting the greatest variation (220 fold) between individuals. This QC RT-PCR assay should prove valuable for measuring basal and induced mRNAs in different cell types in vitro, as well as in biomonitoring applications where individuals are exposed or hypersusceptible to certain xenobiotic-initiated toxicities.

Adolescent↗
PubMed1998

The use of mammography by survivors of breast cancer.

OBJECTIVES: Survivors of breast cancer are at high risk for development of a second breast cancer and are thus a group for whom annual mammography screening is recommended. However, survivors' use of mammography rarely has been examined. METHODS: We surveyed a representative population sample of survivors who lived in rural communities about their mammography use after cancer. RESULTS: Of these women, 30% had not received a mammogram in the preceding year. Predictors of mammography use included physician recommendation and whether the original cancer had been detected by mammography. CONCLUSIONS: Physicians should recommend mammography to survivors of breast cancer to ensure regular use.

Aged↗
PubMed1997

Confirmatory analysis of opinions regarding the pros and cons of mammography.

This investigation extends prior research to apply decision-making constructs from the transtheoretical model (TTM) of behavior change to mammography screening. Study subjects were 8,914 women ages 50-80, recruited from 40 primarily rural communities in Washington State. Structural equation modeling showed that favorable and unfavorable opinions about mammography (i.e., pros and cons) fit the observed data. Analysis of variance supported the associations between readiness to obtain screening (i.e., stage of adoption) and opinions about mammography (i.e., decisional balance) previously found in research using smaller samples from another geographic region. This report extends these earlier studies by using structural equation modeling, opinion scales based both on principal component analyses and on a priori definitions, a developmental sample and a confirmatory sample, and by sampling from a different geographic region. It is recommended that future research examine whether opinions regarding the cons of mammography are more individually specific than the pros.

Aged↗
PubMed1997

Physician gender and screening: do patient differences account for differences in mammography use?

Women are more likely to receive mammography if they see a female, rather than a male, physician (Lurie et al., 1993). This difference in mammography use could arise from differences in the behavior of male and female physicians, or from differences in their patients. This paper examines the extent to which differences in mammography use are attributable to physician differences, controlling for patient differences, and expands on previous research by examining both demographic and attitudinal differences between the patients of male and female physicians. A population based sample of Washington State women (n = 852) between the ages of 50 and 80 years old were asked to complete an extensive telephone interview regarding their demographic and attitudinal characteristics, their mammography use, and the gender of their primary care physician. Women patients of male and female physicians were not found to differ significantly in their education, financial status, employment, assertiveness with their physician, or values regarding physician characteristics including preventive care and communication skills. Analyses conducted to examine the contribution of physician gender to mammography use revealed almost a two-fold reduction in screening associated with having a male physician (adjusted odds ratio 1.95; p < .05). Differences in mammography use associated with male and female physicians do not appear to arise from characteristic demographic or attitudinal differences between their patient populations.

Aged↗
PubMed1996

Somatostatin in the treatment of gastrointestinal bleeding caused by angiodysplasia.

BACKGROUND: Bleeding due to gastrointestinal angiodysplasia is occasionally very difficult to treat by conventional means. METHODS: A 37-year-old woman with recurrent anemia caused by angiodysplasia was treated with a somatostatin analogue, given at a dose of 100 micrograms subcutaneously twice daily. RESULTS: After 26 months of treatment the patient was without any signs or symptoms of bleeding from her gastrointestinal angiodysplasia. CONCLUSIONS: Somatostatin may be efficacious in the treatment of gastrointestinal bleeding due to angiodysplasia. Further investigation is needed.

Adult↗
PubMed1993

[AIDS--knowledge, behavior and attitude at the University of Aarhus in 1990. A questionnaire study].

To describe knowledge, attitude and behaviour regarding AIDS among students and employees at the University of Aarhus an anonymous self-administered questionnaire survey was conducted in April 1990. Of the 2169 and 850 questionnaires to students and employees, respectively, 1548 (71.4%) and 568 (67%) were returned. The study group had an excellent knowledge about AIDS and the transmission of HIV-virus. However, when defining "risk behaviour" in relation to transmission of HIV-virus among heterosexuals as "> or = 2 sexual partners within the past year without using condoms" 27% of the male and 20% of the female students showed risk behaviour. Among employees the rate was highest (23%) among the male scientific staff than among the remainder (17%). It is concluded that risk behaviour was not related to age and occurred in spite of the fact that 42% of the students and 31% of the employees, who showed risk behaviour were also aware of a personal risk of being infected. There is still a need for information about AIDS, and future campaigns should be directed towards all age groups as risk behaviour is not only a phenomenon among young people.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Direct extraction of bacterial plasmids from food for polymerase chain reaction amplification.

In this report we describe a simple and rapid technique using DNA affinity columns that permits direct extraction of bacterial plasmids from a variety of foods for polymerase chain reaction amplification. The procedure was used to detect virulent enteroinvasive Escherichia coli in several artificially seeded matrices, including seafoods, greens, dairy products, enrichment media, and water. Polymerase inhibitors present in both foods and enrichment media were removed efficiently.

DNA, Bacterial↗
PubMed1986

Analysis of various classes of drugs by capillary supercritical fluid chromatography.

Three classes of drugs were screened for analysis feasibility by capillary column supercritical fluid chromatography. These included steroids, therapeutic antibiotic drugs, and drugs of abuse, such as cannabinoids. Supercritical fluid carbon dioxide was used as the mobile phase in conjunction with a methylpolysiloxane stationary phase capillary column and a flame ionization detector. All compounds considered were analyzed either as single component solutions, simple mixtures, or in actual complex mixtures.

Adrenal Cortex Hormones↗
PubMed1986

Nickel in Danish food.

The nickel content of food items consumed in Denmark was estimated on the basis of analysis by atomic absorption spectrophotometry. The highest concentrations (1-10 mg nickel/kg fresh weight) were found in cocoa, licorice, lucerne seeds, dried beans, peanuts, hazel nuts, sunflower seeds, oat meal and wheat bran. A diet instruction sheet is proposed as an aid to reduce the amount of nickel ingested. The nickel intake of 8 normal volunteers for 24-hour periods was measured when they ingested their usual diet, reduced nickel intake by adherence to the diet instruction sheet, and when they made a conscious effort to increase nickel intake. It is concluded that it is possible to reduce daily nickel intake in food items.

Denmark↗
PubMed1984

Pharmacokinetics of topical gentamicin in total hip arthroplasty.

Two different ways of administering topical gentamicin were examined in patients undergoing total hip arthroplasty. 160 mg gentamicin, dissolved in isotonic saline, was instilled into the wounds of five out of ten patients. In the other five patients, the components of the prostheses were inserted by means of gentamicin-containing cement, 0.5 g per 40 g powder. Both the serum concentrations and the wound concentrations of gentamicin were determined constantly during the postoperative period. The average half-lives of gentamicin in the surgical wounds of the two groups of patients were found to be 3 1/2 and 25h, respectively. The average wound concentration was found to be higher than the minimum inhibitory concentration for staphylococci and aerobic Gram-negative rods for 18 and 11 h, respectively, in the group of patients treated with gentamicin solution compared with 160 and 67 h, respectively, in the group treated with the gentamicin-containing cement.

Administration, Topical↗