Citations

Abstract Alcohol is a risk factor for the development of osteoporosis, especially in men. Chronic alcohol abuse decreases bone mass, which contributes to the increased incidence of fractures. To better understand the mechanism of action of ethanol on bone metabolism, we have studied the dose-response effects of ethanol on conditionally immortalized human fetal osteoblasts (hFOB) in culture. Ethanol treatment had no significant effects on osteoblast number after 1 day or 7 days. Ethanol treatment did not reduce type I collagen protein levels at either time point at any dose but slightly reduced alkaline phosphatase activity after 7 days. The messenger RNA (mRNA) levels for alkaline phosphatase, type I collagen, and osteonectin were unaltered by 24 h of ethanol treatment but a high dose (200 mM) reduced mRNA levels for the two bone matrix proteins after 7 days. Ethanol treatment led to dose-dependent increases in transforming growth factor β1 (TGF-β1) mRNA levels and decreases in TGF-β2 mRNA levels. The concentration of ethanol in the medium decreased with time because of evaporation but there was little degradation caused by metabolism. These results, which show that cultured osteoblasts are less sensitive than osteoblasts in vivo, suggest that the pronounced inhibitory effects of ethanol on bone formation are not caused by direct cell toxicity.

Arterial wall stiffness can be associated with various diseases. Arteriosclerosis involves the buildup of plaques within artery walls that stiffen the arteries. The stiffness of an artery can be assessed by measurement of the pulse wave velocity (PWV). Usually, PWV is estimated using the foot-to-foot method. However, the foot of the pressure wave is not very clear due to reflected waves. Also, the blood pressure wave generated by the heart is normally a low frequency wave, hence the time resolution is low. PWV is an average indicator of artery stiffness between the two measuring positions, and therefore cannot easily identify local stiffness. In this paper a force on the arterial wall is generated noninvasively by the radiation force of ultrasound. Techniques for measuring the propagating wave due to this localized force are studied. The excitation force can be either a very short pulse or a modulated cw signal of a few hundred hertz. The temporal resolution of this method, which is in the range of microseconds, is much higher than the conventional pressure PWV method, and therefore allows the wave velocity to be measured accurately over short distances of a few millimeters.

CD4 T cells, through the release of cytokines as well as direct effector functions, have been implicated in promoting inflammation of the atherosclerotic plaque. Plaque-infiltrating CD4 T cells include a specialized subset of CD4 + CD28 − T cells that express a unique profile of regulatory receptors and are responsive to novel microenvironmental cues. Here we report that CD4 + CD28 − T cells, either isolated from the plaque tissue or from the blood of patients with acute coronary syndrome (ACS), spontaneously express interleukin (IL)-12 receptors, even in the absence of antigenic stimulation. CD4 + CD28 − IL-12R + cells responded to IL-12 stimulation with the upregulation of the chemokine receptor CCR5 and the C-type lectin receptor CD161, both implicated in regulating tissue homing of effector T cells. IL-12 treatment of CD4 + CD28 − T cells enhanced their chemotaxis and transendothelial migration toward the chemokine CCL5. In vivo relevance for the role of IL-12 in regulating the recruitment of CD4 + CD28 − T cells into the atheroma was examined in human atheroma-SCID mouse chimeras. Exposure of nonstimulated CD4 + CD28 − T cells to IL-12 was sufficient to amplify T-cell accumulation within the inflamed plaque, and coadministration of anti-CCR5 antibodies blocked T-cell recruitment into the plaque. Thus, CD4 + CD28 − T cells functionally resemble NK cells, which have proinflammatory activity even in the unprimed state and respond to any IL-12–inducing host infection with a shift in tissue trafficking and accrual in inflammatory lesions.

Most non-Hodgkin lymphomas (NHLs) are of B-cell origin, but the tumor tissue can be variably infiltrated with T cells. In the present study, we have identified a subset of CD4+CD25+ T cells with high levels of CTLA-4 and Foxp3 (intratumoral Treg cells) that are overrepresented in biopsy specimens of B-cell NHL (median of 17% in lymphoma biopsies, 12% in inflammatory tonsil, and 6% in tumor-free lymph nodes; P = .001). We found that these CD4+CD25+ T cells suppressed the proliferation and cytokine (IFN-γ and IL-4) production of infiltrating CD4+CD25- T cells in response to PHA stimulation. PD-1 was found to be constitutively and exclusively expressed on a subset of infiltrating CD4+CD25- T cells, and B7-H1 could be induced on intratumoral CD4+CD25+ T cells in B-cell NHL. Anti-B7-H1 antibody or PD-1 fusion protein partly restored the proliferation of infiltrating CD4+CD25- T cells when cocultured with intratumoral Treg cells. Finally, we found that CCL22 secreted by lymphoma B cells is involved in the chemotaxis and migration of intratumoral Treg cells that express CCR4, but not CCR8. Taken together, our results suggest that Treg cells are highly represented in the area of B-cell NHL and that malignant B cells are involved in the recruitment of these cells into the area of lymphoma.

AbstractBecause fruits and vegetables are rich in bioactive compounds with potential cancer-preventive actions, increased consumption may reduce the risk of ovarian cancer. Evidence on the association between fruit and vegetable intake and ovarian cancer risk has not been consistent. We analyzed and pooled the primary data from 12 prospective studies in North America and Europe. Fruit and vegetable intake was measured at baseline in each study using a validated food-frequency questionnaire. To summarize the association between fruit and vegetable intake and ovarian cancer, study-specific relative risks (RR) were estimated using the Cox proportional hazards model, and then combined using a random-effects model. Among 560,441 women, 2,130 cases of invasive epithelial ovarian cancer occurred during a maximum follow-up of 7 to 22 years across studies. Total fruit intake was not associated with ovarian cancer risk—the pooled multivariate RR for the highest versus the lowest quartile of intake was 1.06 [95% confidence interval (95% CI), 0.92-1.21; P value, test for trend = 0.73; P value, test for between-studies heterogeneity = 0.74]. Similarly, results for total vegetable intake indicated no significant association (pooled multivariate RR, 0.90; 95% CI, 0.78-1.04, for the highest versus the lowest quartile; P value, test for trend = 0.06; P value, test for between-studies heterogeneity = 0.31). Intakes of botanically defined fruit and vegetable groups and individual fruits and vegetables were also not associated with ovarian cancer risk. Associations for total fruits and vegetables were similar for different histologic types. These results suggest that fruit and vegetable consumption in adulthood has no important association with the risk of ovarian cancer.

Abstract Galectin-3 (Gal-3), a β-galactoside-binding protein is expressed in a specific cell–type manner in pituitary tumors. Here we questioned the mechanism of Gal-3 expression in pituitary tumors, by using methylation-specific PCR and DNA sequence analyses to analyze the methylation status of the promoter region of the LGALS3 gene. DNA analysis of a human pituitary tumor, breast carcinoma cell lines, and thyroid carcinoma cell lines showed that in cells expressing Gal-3 protein, the LGALS3 gene was unmethylated, whereas in Gal-3 null cells, the promoter of the LGALS3 gene was methylated. Treatment of cells with 30 μmol/L 5-aza-2′-deoxycytidine induced Gal-3 mRNA and protein expression. Among pituitary tumors, 30% (7/23), mainly in follicle-stimulating hormone/luteinizing hormone–producing (38%) and null cell (57%) adenomas, the promoter of the LGALS3 was found to be methylated and silenced, although prolactin- and adrenocorticotropic hormone–producing tumors, which were unmethylated, expressed the Gal-3 protein. These results show for the first time that Gal-3 expression is regulated in part by promoter methylation in pituitary as well as in other tumors. Because it is functionally involved in cancer progression and metastasis, Gal-3 may serve as a possible therapeutic target in the treatment of pituitary tumors.

Epigenetic inheritance of heterochromatin structure is an important cellular process whose mechanism remains elusive. In this article, we describe the identification of nine enhancers of the silencing defect of a Saccharomyces cerevisiae -PCNA mutant by screening a library of ≈4,700 viable yeast deletion mutants. Of the nine mutants identified, six ( hir1 , hir3 , sas2 , sas4 , sas5 , and sir1 ) were previously known to reduce silencing synergistically with a mutation in Cac1p, the large subunit of chromatin assembly factor 1 (CAF-1). The predicted gene products that are affected in three other mutants ( nam7 , msh2 , and rtt106 ) have not been implicated previously in silencing. Characterization of the rtt106 Δ allele revealed that it synergistically reduced heterochromatin silencing when combined with a mutation in Cac1p but not with a mutation in Asf1p (a histone H3 and H4 chaperone). Moreover, Rtt106p interacted with histones H3 and H4 both in vitro and in vivo , and it displayed a nucleosome assembly activity in vitro . Furthermore, Rtt106p interacts with CAF-1 physically through Cac1p. These biochemical and genetic data indicate that Rtt106p is a previously uncharacterized histone chaperone connecting S phase to epigenetic inheritance.

Clinical Pharmacology & Therapeutics (2003) 73, P81–P81; doi: