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Biomedical subjects

G Murillo

Publications and source records attributed to G Murillo.

9 recordsLinked to original sources

Deguelin inhibits the growth of colon cancer cells through the induction of apoptosis and cell cycle arrest.

As previously demonstrated, deguelin [(7aS, BaS)-13, 13a-dihydro-9,10-dimethoxy-3,3-dimethyl-3H-bis[1]benzo-pyrano[3,4-b:6',5'-e]pyran-7(7aH)-one mediates anti-proliferative properties in a variety of cell types. In the present study, deguelin was found to suppress the growth of HT-29 colon cancer cells with an IC(50) of 4.32 x 10(-8) M. The cells were arrested in the G1-S-phase of the cycle. Investigations of G1/S regulatory proteins by Western blot analyses showed an upregulation of p27, and decreased expression levels of cyclin E and CDK4. Furthermore, by 24 h, exposure to deguelin resulted in an increase in the hypophosphorylated form of Rb. Since hypophosphorylated pRb binds to and inactivates E2F1, additional studies were performed and downregulation of E2F1 was observed after 24 h of treatment with deguelin. These results are consistent with the observation that deguelin arrested cells in the G1-S- phase. In addition, based on ethidium bromide/acridine orange staining, detection of digoxigenin-labelled genomic 3'-OH DNA ends, and DNA laddering, it was found that deguelin exerts its growth inhibitory effects via the induction of apoptosis. Based on these data, the potential of deguelin to serve as a cancer chemotherapeutic agent for colon cancer may be suggested.

Antineoplastic Agents↗

Cruciferous vegetables and cancer prevention.

In recent years, cancer prevention by natural products has received considerable attention. The potential protective role of cruciferous vegetables and active components present in these vegetables, such as isothiocyanates and indole-3-carbinol, has been extensively studied in experimental in vitro and in vivo carcinogenesis models. Results have consistently shown that the chemopreventive agents derived from this class of vegetables of the Cruciferae family influence carcinogenesis during initiation and promotion phases of cancer development. Similarly, reports from epidemiological studies and clinical trials support this notion. However, there is no comprehensive summary of all these aspects of the association between cruciferous vegetables and cancer prevention. We have attempted to summarize experimental carcinogenesis studies as well as clinical trials and studies on the mechanism of action of selective chemopreventive agents isolated and identified within these natural products. Results clearly point toward a positive correlation between cancer prevention of many target organs and consumption of cruciferous vegetable or their active constituents. Yet we are still far from complete understanding of the effects of combinations of chemopreventive phytochemicals present in these cruciferous vegetables and their overall mechanism(s) of action in providing protective effects.

Animals↗

Cardiovascular disease risk factors in 2 distinct ethnic groups: Indian and Pakistani compared with American premenopausal women.

BACKGROUND: Although people from the Indian subcontinent have high rates of cardiovascular disease (CVD), studies of such in Indian and Pakistani women living in the United States are lacking. OBJECTIVE: This study accounted for variability in serum lipid (total cholesterol and triacylglycerol) and lipoprotein [LDL cholesterol, lipoprotein(a), and HDL cholesterol] concentrations in Indian and Pakistani compared with American premenopausal women in the United States. Body composition, regional fat distribution, dietary intake, and energy expenditure were compared between groups. DESIGN: The 2 groups were 47 Indian and Pakistani and 47 American women. Health was assessed via medical history, physical activity, body composition (via anthropometry and dual-energy X-ray absorptiometry), dietary intake (via 7-d food records), and serum lipids. RESULTS: Serum total cholesterol, triacylglycerol, LDL cholesterol, lipoprotein(a), the ratio of total to HDL cholesterol, and the ratio of LDL to HDL cholesterol were greater (P <0.03), whereas HDL-cholesterol values were lower (P = 0.011) in Indians and Pakistanis than in Americans. Multiple regression analysis indicated that approximately 18% of the variance in total cholesterol (P = 0.0010) and LDL cholesterol (P = 0.0009) was accounted for by ethnicity, energy expenditure, and the ratio of the sum of central to the sum of peripheral skinfold thicknesses. Ethnicity, sum of central skinfold thicknesses, ratio of polyunsaturated to saturated fat, and monounsaturated fat intake accounted for approximately 43% of the variance in triacylglycerol concentration (P < 0.0001). Monounsaturated fat, percentage body fat, and alcohol intake accounted for approximately 26% of variance in HDL cholesterol. Ethnicity contributed approximately 22% of the 25% overall variance in lipoprotein(a). CONCLUSIONS: Results suggest that these Indian and Pakistani women are at higher CVD risk than their American counterparts, but that increasing their physical activity is likely to decrease overall and regional adiposity, thereby improving their serum lipid profiles.

Absorptiometry, Photon↗

Breast cancer risk factors in two distinct ethnic groups: Indian and Pakistani vs. American premenopausal women.

Asian Indians from the Indian subcontinent have low rates of breast cancer, but studies on breast cancer risk factors in Indian and Pakistani women living in the United States are lacking. This study contrasted breast cancer risk factors [serum total 17 beta-estradiol (E2), sex hormone-binding globulin-bound E2, available E2, estrone (E1), and dehydroepiandrosterone sulfate, reproductive history, family history of cancer, body composition/size, dietary intake, physical activity, and excretion of isoflavones] between two distinct ethnic groups of premenopausal women residing in the United States. We also determined the contribution of these and other factors to the variability of each sex hormone. Distributions of values for serum total E2, available E2, and sex hormone-binding globulin-bound E2 (%) were greater (p < 0.005) in American (n = 47) than in Indian and Pakistani (n = 47) women. Multiple regression analysis indicated that 26% of the variability (p < or = 0.0001) in serum E2 was accounted for by the ratio of total cholesterol to high-density-lipoprotein cholesterol, length of time in the United States, and saturated fat intake, whereas less (17%) variability was accounted for by available E2 (representing free E2 + albumin-bound E2), contributed by the ratio of total cholesterol to high-density-lipoprotein cholesterol and saturated fat intake. Five variables accounted for 31% of the variability (p < or = 0.0001) in E1. The major finding of this study was that circulating sex hormone concentrations were determined more by environmental factors than by ethnicity, which was not a significant contributor to any of the serum hormones.

Adult↗

Urbanization, the informal sector and migration: issues for research and cooperation.

Only recently have development studies begun to examine the complex set of relationships between urbanization, the growth of the informal sector, and internal migration in Latin America. This paper suggests that the economic crisis of the 1980s has resulted in significant changes in these phenomena and that 1 of the most important changes has been the growth of return international migration between Latin American countries. Also of importance are the continued migration flows to North America. The paper argues that the interconnectedness of these phenomena requires more multinational research efforts.

Americas↗

d3/2 1p

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Journal Article↗