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Biomedical subjects

J Andersen

Publications and source records attributed to J Andersen.

At least 379 records · Page 21Linked to original sources
PubMedDate not supplied

Phylogeny of the 5S ribosomal RNA from Synechococcus lividus II: the cyanobacterial/chloroplast 5S RNAs form a common structural class.

The complete nucleotide sequence of the 5S ribosomal RNA from the cyanobacterium Synechococcus lividus II has been determined. The sequence is (sequence in text) This 5S RNA has the cyanobacterial- and chloroplast-specific nucleotide insertion between positions 30 and 31 (using the numbering system of the generalized eubacterial 5S RNA) and the chloroplast-specific nucleotide-deletion signature between positions 34 and 39. The 5S RNA of S. lividus II has 27 base differences compared with the 5S RNA of the related strain S. lividus III. This large difference may reflect an ancient divergence between these two organisms. The electrophoretic mobilities on nondenaturing polyacrylamide gels of renatured 5S RNAs from S. lividus II, S. lividus III, and spinach chloroplasts are identical, but differ considerably from that of Escherichia coli 5S RNA. This most likely reflects differences in higher-order structure between the 5S RNA of E. coli and these cyanobacterial and chloroplast 5S RNAs.

Base Sequence↗
PubMedDate not supplied

Leiomyoma primary cultures have elevated transcriptional response to estrogen compared with autologous myometrial cultures.

OBJECTIVE: We tested the hypothesis that uterine leiomyomas are hypersensitive to estrogen as compared with autologous human myometrium. METHODS: The estrogen-induced transcriptional responses of uterine leiomyoma and myometrial primary cultures were determined by transient expression assays. The relative levels of estrogen receptor (ER) in myometrial and leiomyoma tissues were determined by immunoblot. RESULTS: Myometrial and leiomyoma primary cultures were transcriptionally responsive to the estrogen ethinyl estradiol (eE2). The partial agonist tamoxifen did not elicit a positive transcriptional response and antagonized estrogen-induced transcription in the cultured cells. The responses of hormone-treated leiomyoma cells averaged 4.5-fold higher than those in controls with no hormone (P = .0001). The myometrial cells from women in the follicular phase exhibited little if any transcriptional response to eE2, whereas myometrial cells from women in the luteal phase had a transcriptional response to eE2 averaging threefold higher than that in no-hormone controls (P = .0083). Differences in response between autologous myometrial and leiomyoma cultures were statistically significant by the two-tailed Wilcoxon paired nonparametric signed-rank test (n = 11; P = .0137). These differences were more pronounced in cultures from women in the follicular or early luteal phase. In addition, the levels of ER increased in follicular and early luteal phase myometrial tissues, which correlated well with the number of days from the last menstrual period (n = 8; r = 0.9046; P = .002). Estrogen-receptor levels in myometrial tissues decreased during the late luteal phase. Levels in leiomyoma tissues did not follow the same pattern as in the myometrium and were elevated in tissues taken from women in the follicular phase. CONCLUSIONS: Autologous leiomyoma cultures have a significantly higher response to estrogen than do matched myometrial cultures, especially if the cultures are derived from the follicular phase. The levels of ER in leiomyoma tissue from women in the follicular phase are significantly elevated.

Adult↗
PubMedDate not supplied

Abnormal gene expression in uterine leiomyomas.

Uterine leiomyomas, benign tumors of myometrial origin, are the most common neoplasms of the uterus and occur in 20-30% of women over 30 years of age. Despite their high prevalence, little is known about the pathophysiology of these tumors. Recently, several studies have compared leiomyoma gene expression with that of normal myometrium. In general, the major differences in leiomyoma and myometrial gene expression are found for estrogen-regulated genes, which have elevated expression in myometrium during pregnancy. The tumors appear to maintain high sensitivity to estrogen during the estrogen-dominated follicular phase of the menstrual cycle, unlike normal myometrium. The abnormal gene expression of leiomyomas suggests that they are tumors of dysregulated differentiation and resemble the myometrium of pregnancy in several aspects.

Adult↗
PubMedDate not supplied

Long-term follow-up confirms a survival advantage of the paclitaxel-cisplatin regimen over the cyclophosphamide-cisplatin combination in advanced ovarian cancer.

Two independent and consecutive randomized clinical trials, conducted by the American Gynecological Oncology Group and by an European-Canadian Intergroup, have shown superiority, in clinical response rate, progression-free survival, and overall survival, of a cisplatin-paclitaxel regimen over cisplatin-cyclophosphamide given as first-line chemotherapy for women with advanced epithelial ovarian cancer. The results of these studies, published with a median follow-up of about 3 years, have been updated with a 6.5-year follow-up: In each case, an 11% absolute gain in survival favoring the paclitaxel arm is shown; this advantage remains both statistically and clinically significant and supports a role for paclitaxel in frontline chemotherapy for advanced ovarian cancer.

Antineoplastic Combined Chemotherapy Protocols↗