GSTM1 genotypes have a significant effect on the metabolism of sulforaphane derived from standard or high-glucosinolate broccoli. It is possible that the difference in metabolism may explain the greater protection that GSTM1-positive persons gain from consuming broccoli. The potential consequences of consuming glucosinolate-enriched broccoli for GSTM1-null and -positive persons are discussed.
The feasibility of developing a forecasting system for carpogenic germination of Sclerotinia sclerotiorum sclerotia was investigated in the laboratory by determining key relationships among temperature, soil water potential, and carpogenic germination for sclerotia of two S. sclerotiorum isolates. Germination of multiple burials of sclerotia to produce apothecia also was assessed in the field with concurrent recording of environmental data to examine patterns of germination under different fluctuating conditions. Carpogenic germination of sclerotia occurred between 5 and 25 degrees C but only for soil water potentials of >/=-100 kPa for both S. sclerotiorum isolates. Little or no germination occurred at 26 or 29 degrees C. At optimum temperatures of 15 to 20 degrees C, sclerotia buried in soil and placed in illuminated growth cabinets produced stipes after 20 to 27 days and apothecia after 27 to 34 days. Temperature, therefore, had a significant effect on both the rate of germination of sclerotia and the final number germinated. Rate of germination was correlated positively with temperature and final number of sclerotia germinated was related to temperature according to a probit model. Thermal time analysis of field data with constraints for temperature and water potential showed that the mean degree days to 10% germination of sclerotia in 2000 and 2001 was 285 and 279, respecttively, and generally was a good predictor of the observed appearance of apothecia. Neither thermal time nor relationships established in the laboratory could account for a decline in final percentage of germination for sclerotia buried from mid-May compared with earlier burials. Exposure to high temperatures may explain this effect. This, and other factors, require investigation before relationships derived in the laboratory or thermal time can be incorporated into a forecasting system for carpogenic germination.
Sulforaphane (SF), a dietary phytochemical obtained from broccoli, has been implicated in several physiological processes consistent with anticarcinogenic activity, including enhanced xenobiotic metabolism, cell cycle arrest, and apoptosis. In this study, we report changes in global gene expression in Caco-2 cells exposed to physiologically appropriate concentrations of SF, through the use of replicated Affymetrix array and RT-PCR experiments. After exposure to 50 micromol/L SF, 106 genes exhibited a >2-fold increase in expression and 63 genes exhibited a >2-fold decrease in expression. There were fewer changes in gene expression at lower SF concentrations. The majority of these genes had not previously been shown to be modulated by SF, suggesting novel mechanisms of possible anticarcinogenic activity, including induction of differentiation and modulation of fatty acid metabolism. The changes in the expression of 10 of these genes, together with 4 additional genes of biological interest, were further quantified in independent studies with RT-PCR. These genes include several that have recently become associated with carcinogenesis, such as Krüppel-like factor (KLF)4, a gut-enriched transcription factor associated with induction of differentiation and reduction in cellular proliferation; DNA (cytosine-5-)-methyltransferase 1, associated with methylation; and alpha-methylacyl-CoA racemase (AMACR), a marker associated with the development of colon and prostate cancer. The expression of 5 of these genes [caudal type homeo box transcription factor 2 (CDX-2), KLF4, KLF5, cyclin-dependent kinase inhibitor 1A (p21), and AMACR] was additionally studied after in vitro exposure to SF of surgically resected healthy and cancerous colon tissue from each of 3 patients. The study suggests the complex effects that SF has on gene expression and highlights several potential mechanisms by which the consumption of broccoli may reduce the risk of carcinogenesis.
Epidemiological studies suggest that a diet rich in broccoli can reduce the risk of cancer at several sites. The anticarcinogenic activity has been largely attributed to the biological activity of sulforaphane (SF), the isothiocyanate derived from 4-methylsulphinylbutyl glucosinolate, which accumulates in broccoli. SF induces xenobiotic metabolizing genes in both cell cultures and animal models and induces genes associated with cell cycle arrest and apoptosis. However, it is not known whether these genes are induced in humans after consumption of broccoli. Sixteen subjects were recruited into a randomized, 3-phase crossover dietary trial of standard broccoli, high glucosinolate broccoli, and water. Global changes in gene expression that occurred 6 h after consuming broccoli soups or water were quantified in gastric mucosal tissue, using Affymetrix whole genome microarrays (n = 4), and in selected genes by real-time RT-PCR in the other individuals. Consumption of high glucosinolate broccoli resulted in up-regulation of several xenobiotic metabolizing genes, including thioredoxin reductase, aldoketoreductases, and glutamate cysteine ligase modifier subunit, which have previously been reported to be induced in cell and animal models after exposure to SF. Only 1 such gene was significantly up-regulated after consumption of standard broccoli. The consequences of these results in relation to the potential anticarcinogenic action of broccoli are discussed.
Passive or emotion-focused coping strategies are typically related to worse pain and adjustment among chronic pain patients. Emotional approach coping (EAC), however, is a type of emotion-focused coping that appears to be adaptive in some nonpain populations but has not yet been examined in a chronic pain population. In a sample of 80 patients (75% women, M = 48.67 years of age) with chronic myofascial pain, we contrasted how EAC (assessed with the Emotional Approach Coping Scale) and 5 passive pain-coping strategies (assessed with the Vanderbilt Multidimensional Pain Coping Inventory (VMPCI)) were related to sensory and affective pain, physical impairment, and depression. Passive coping strategies were positively correlated with one another, but EAC was inversely correlated with most of them. The VMPCI passive strategies were substantially positively related to negative affect, whereas EAC was inversely related to negative affect. Controlling for potentially confounding demographics, higher EAC was related to less affective pain and depression, even after controlling for negative affect. Using passive coping strategies, in contrast, was associated with more pain, impairment, and depression, although these relations were greatly attenuated after controlling for negative affect. When considered simultaneously, EAC, but not passive coping, was related to affective pain, and both EAC and passive coping were significant correlates of depression, although in opposite directions. In secondary analyses, we found that EAC was related to less pain (particularly sensory) among men and to less depression among women. Unlike the use of passive pain-coping strategies, which are associated with worse pain and adjustment, the use of EAC (emotional processing and emotional expression) with chronic pain is associated with less pain and depression. This suggests that some emotion-focused types of pain coping may be adaptive, and it highlights the need to assess emotional coping processes that are not confounded with distress or dysfunction.
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