Medullary thyroid carcinoma (MTC) originates from parafollicular C cells. Estrogen receptor b (ERb) expression was detected in normal parafollicular C cells and MTC tumor tissue, but ERa expression in MTC tumors still remains undetermined. The appearance and loss of ERa or ERb expression has been known to play a role in the development and progression of many human cancers. We performed immunohistochemical studies of ERa, ERb, and Ki67, a mitotic index, in 11 human MTC tissue samples. ERa was detected in 10 cases (91%), and ERb expression was observed in 8 cases (72 . 7%). A majority (8/10) of ERa-positive tumors showing ERb Ki67 expression was detected in three cases (27 . 3%). Neither clinical parameters nor tumor node metastasis (TNM) tumor staging was correlated with the positivity for ERs or Ki67. To investigate the biological role of each ER, we used ER-negative MTC TT cells and adenoviral vectors carrying ERa (Ad-ERa), ERb (Ad-ERb), estrogen response element (ERE)-Luc (Ad-ERE-Luc), and activator protein 1 (AP1)-Luc (Ad-AP1-Luc). Estrogen stimulated and anti-estrogen, ICI 182 780, suppressed ERE reporter activity in TT cells expressing ERa or ERb, suggesting that both ERs use the same classical ERE-mediated pathway. Ad-ERa infection stimulated TT cell growth; in contrast, Ad-ERb infection suppressed their growth. Apoptosis was detected in Ad-ERb-infected TT cells. Estrogen and antiestrogen suppressed AP1 activity in Ad-ERa-infected cells, whereas upon Ad-ERb infection estrogen further stimulated AP1 activity which in turn is suppressed by anti-estrogen, suggesting that each ER acts differently through a non-EREmediated pathway. Our results suggest that ERa and ERb may play different roles in MTC tumor growth and progression.
Although low bone mass has been associated with atherosclerosis even after adjustment for age, little is known about the association between vertebral fractures and calcified atherosclerotic plaques. Our objective was to investigate whether osteoporotic vertebral fractures are independently related to the prevalence of atherosclerotic carotid plaques in postmenopausal women with low bone mass. We enrolled 195 postmenopausal women with osteopenia or osteoporosis. Bone mineral density and the presence of vertebral fractures were assessed. Intima media thickness and atherosclerotic plaques of the carotid artery were assessed using ultrasonography. Of the 195 subjects in the study, 84 had no plaques and 111 had at least one. The percentage of women with vertebral fractures was significantly higher in subjects with echogenic carotid plaques than in those without (27% vs. 11%, respectively; P < 0.05). However, there was no difference in the prevalence of vertebral fractures between women with echolucent plaques and those without (10.9% vs. 10.7%, respectively; P = nonsignificant). By logistic regression analysis with multivariate adjustment, age (P < 0.01), dyslipidemia (P < 0.05), and the presence of vertebral fracture (P < 0.05) were independent risk factors for echogenic carotid plaques. Osteoporotic vertebral fractures are associated with an increased risk of echogenic atherosclerotic plaques in postmenopausal women with low bone mass. It appears that the high association of echogenic atherosclerotic plaques and vertebral fractures could partially explain why osteoporotic vertebral fractures are linked to increased mortality.
Radish (Raphanus sativus L.) belongs to the family Brassicaceae, and is an important plant that is cultivated throughout Asia. Korean varieties are rich in vitamins B and C and have important medicinal properties. However, many of these varieties are susceptible to various pathogens and conventional breeding is not successful in introducing resistance genes into the varieties because of limited availability of germplasm. Alternatively, it is required to establish a genetic transformation system of this species to transfer resistance genes from various sources rather than radish germplasm. The importance and needs for the genetic improvement of radish have recently been reviewed by Curtis (2003). A floral-dip method previously developed for genetic transformation of Arabidopsis (Clough and Bent 1998) was used for radish, resulting in genetic transformation frequencies of 1.1%-1.4% (Curtis and Nam 2001;Curtis et al. 2002). However, transgenic plants produced only 50-100 seeds per individual. Furthermore, many of the plants were siblings (Curtis et al. 2004). Therefore, Agrobacterium-mediated transformation might be more appropriate to this species as demonstrated in a vast array of other crops. A few efficient adventitious shoot regeneration systems were developed for Japanese (Matsubara and Hegazi 1990), Chinese (Pua et al. 1996), and Korean ecotypes of radish (Curtis et al. 2004). However, there have been no reports on production of transgenic radish by Agrobacteriummediated transformation. This paper describes Agrobacterium-mediated genetic transformation of radish using adventitious shoot formation on hypocotyl explants.Zygotic embryos of F1 hybrid radish (Raphanus sativus L. cv. Jin Ju Dae Pyong) were used. Seeds were surface disinfected with 70% ethanol for 1 min and then with 0.4% sodium hypochlorite solution for 15 min. They were rinsed three times with sterile deionizeddistilled water before being placed on MS medium (Murashige and Skoog 1962) without growth regulators contained in Petri dishes. The pH of all media was adjusted before autoclaving. Twenty-five ml of medium was dispensed into 90ϫ15-mm plastic Petri dishes. After 5 to 7 days of incubation in the dark, hypocotyls, 4 to 6-cm long, were decapitated from 5 to 7 day old seedlings and then cut into 5 to 7-mm long segments (hypocotyl explants). To determine the optimum concentration and combination of growth regulators for adventitious shoot formation, hypocotyl explants were cultured on MS Abstract In order to generate transgenic radish (Raphanus sativus L., cv. Jin Ju Dae Pyong), hypocotyl explants were cultured on Murashige and Skoog medium containing 4 mg l Ϫ1 AgNO 3 , 5 mg l Ϫ1 acetosyringone, 4 mg l Ϫ1 6-benzyladenine, and 3 mg l Ϫ1 a-naphthaleneacetic acid in addition to either 10 mg l Ϫ1 hygromycin or 100 mg l Ϫ1 paromomycin after cocultivation with disarmed Agrobacterium tumefaciens harboring a plant expression binary vector. Explants co-cultivated with A. tumefaciens GV3101 harboring pCAMBIA1301 and A. tumefaciens EHA101 harboring pPTN290...
The fat gene in mice represents a recessive mutation at the carboxypeptidase E (Cpe) locus. The mutant allele (Cpe(fat)) encodes a highly unstable enzyme and produces an obesity phenotype characterized by attenuated processing of prohormones such as proinsulin that require this exopeptidase for full maturation. This article presents a preliminary physiologic and endocrinologic characterization of the stock of C57BLKS/LtJ-Cpe(fat)/Cpe(fat) mice at the backcross generation (N10) currently distributed by The Jackson Laboratory. Although previously reported not to be diabetogenic at N5, an additional five backcrosses to the C57BLKS/J background resulted in a male-biased development of both obesity and diabetes. Major differences distinguishing this mutant stock from the phenotypes produced by either the diabetes (Lepr(db)) or obese (Lep(ob)) mutations on the same inbred strain background are lack of hyperphagia and hypercorticism, sensitivity of diabetic males to exogenous insulin, and a milder and male-biased diabetes syndrome that is not associated with widespread beta-cell necrosis and islet atrophy, and that often remits with age.
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