Biomedical subjects

Imre Földesi

Publications and source records attributed to Imre Földesi.

3 recordsLinked to original sources

PubMed2006

Elevated levels of circulating insulin-like growth factor-I, IGF-binding globulin-3 and testosterone predict hormone-dependent breast cancer in postmenopausal women: a case-control study.

There is increasing evidence that different types of breast cancers are related to distinct risk factors. We analyzed the risk of breast cancer with respect to circulating insulin-like growth factor (IGF)-I, IGF-binding protein (IGFBP)-3, 17beta-estradiol, estrone, testosterone, androstenedione and sex hormone-binding globulin (SHBG), taking into consideration the characteristics of the tumors. Plasma hormone levels of 102 postmenopausal patients with breast cancer detected by mammography screening, and 102 matched controls were analyzed in relation to the histological type, the status of the estrogen receptor (ER), the progesterone receptor (PR) and the HER2 in the tumors. Significant positive associations were revealed between the IGF-I concentration and the overall risk of breast cancer (OR=3.1, 95% CI: 1.5-6.2), ER+PR+ breast cancer (OR=2.4, 95% CI: 1.1-5.4) and ER+PR- breast cancer (OR=4.3, 95% CI: 1.2-14.3) when the highest and the lowest ranges of IGF-I were compared. Significant associations were also found between the highest and the lowest quartiles of testosterone, resulting in OR=4.1 (95% CI: 1.8-9.4) for the risks of breast cancer and OR=5.8 (96% CI: 2.1-16.2) of ER+PR+ breast cancer. A synergy was seen between IGF-I and testosterone levels. When both plasma IGF-I and testosterone were in the highest quartile ranges, an OR=26.4 (95% CI: 1.6-426.5, p=0.021) was computed for breast cancer overall. No significant synergistic effects could be demonstrated with other parameters. There were significant, 2.5-fold (95% CI: 1.2-5.6), and 16-fold (95% CI: 2.0-133.5) increases in the overall risks of breast cancer and of ER+PR- breast cancer, respectively, when the highest and the lowest quartiles of IGFBP-3 were compared. No associations were found between any of the hormones and the risk of ER-PR- tumors. The increased prevalence of ER+ breast cancers in patients with higher levels of IGF-I, IGFBP-3 or testosterone implicate these hormones in the etiology of hormone-dependent breast cancer. Additional analyses specific for breast cancer subtypes may shed light on the value of hormone determinations for tailored chemoprevention.

Aged↗

PubMed2005

Pregnancy-induced decrease in the relaxant effect of terbutaline in the late-pregnant rat myometrium: role of G-protein activation and progesterone.

The effectiveness of beta2-agonists in preterm delivery is reduced by several factors. The aim of this study was to determine the influence of late pregnancy in the uterus-relaxing effect of terbutaline in the rat in vitro. Rat uterine tissues from late pregnancy (days 15, 18, 20 and 22) were used. In vitro electrical field-stimulation (EFS) was used to evoke contractions. The radioligand-binding technique, reverse transcription-polymerase chain reaction and radioimmunoassay technique were used to determine the beta-adrenergic receptor density and mRNA level and the plasma sex hormone level, respectively. The activated G-protein level of the beta-adrenergic receptors was investigated by a radiolabelled GTP binding assay.EFS-induced contractions were inhibited by terbutaline. This effect decreased towards term with respect to both the EC50 and maximal inhibition values. A drop in plasma progesterone level was also detected. Binding studies revealed an increase in beta-adrenergic receptor number on the last day of pregnancy, which correlated with the change in receptor mRNA level. The G-protein-activating effect of terbutaline decreased continuously between days 15 and 20. Surprisingly, terbutaline decreased the G-protein activation to below the basal level on day 22. However, progesterone pretreatment set back the uterine action of terbutaline, increased the density of the beta2-adrenergic receptors and their mRNA level and increased the G-protein-activating property of terbutaline. These data provide evidence of a pregnancy-induced decrease in activated G-protein level after beta2-agonist stimulation. The decrease in plasma progesterone level has a crucial role in this process. The effects of beta2-adrenergic receptor agonists in tocolytic therapy may possibly be potentiated with progesterone.

Animals↗

PubMed2004

Beta 2-agonist treatment enhances uterine oxytocin receptor mRNA expression in pregnant rats.

The objective of this study was to disclose an interaction between Beta(2)-adrenergic (Beta(2)-ARs) and oxytocin (OT) receptors (OTRs) in the late-pregnant rat uterus. We investigated the level of uterine OTR mRNA expression after the administration of Beta(2)-AR agonists fenoterol and hexoprenaline to rats from day 18 to 22 of pregnancy, and also tested the effect of fenoterol on uterine explants. Hexoprenaline induced a maximum 24% increase of OTR mRNA. Fenoterol in vivo elicited a maximum 125% increase of OTR mRNA, in vitro produced a maximum fourfold increase in OTR mRNA. In fenoterol-treated rats the maximal contractility increasing effect of OT on isolated uterine rings was significantly higher than in intact term pregnant rats, but the EC50 values were not statistically different. It was concluded that the enhanced expression of OTR mRNA induced by Beta(2)-agonists in the late-pregnant rat uterus may be a possible drawback to effective therapy of preterm uterine contractions with Beta(2)-agonists.

Adrenergic beta-Agonists↗