Progesterone and progestins: applications in gynecology

Achievements obtained in infertility treatments over the past two decades have sparked interest in optimizing progesterone administration. Although progesterone is absorbed orally when ingested in micronized form, bioavailability is poor because of extensive liver metabolism. This explains why full predecidual transformation of the endometrium cannot be achieved with oral progesterone and is therefore ineffective for luteal support in in vitro fertilization (IVF). Progesterone administered non-orally can duplicate the endometrial changes normally seen in the menstrual cycle in women whose ovaries are inactive. Similar results have been reported with intramuscular (i.m.) injections and vaginal administration, although tissue levels are higher in the latter case. The recent development of a controlled and sustained release vaginal progesterone gel, Crinone(R) 8%, has made the vaginal route clinically practical by limiting the number of necessary applications to 1 per day. This regimen has been found at least as effective as intramuscular (i.m.) injections in women whose ovaries are inactive (donor egg IVF) and for luteal support in regular IVF. Hence, painful daily i.m. injections of progesterone in oil become unnecessary. The possibility of reducing the number of daily applications of vaginal progesterone to 1 per day, made possible by the sustained release gel Crinone, has opened new possibilities for long-term treatments, as in hormone replacement therapy (HRT). The low incidence of systemic side effects with use of the vaginal progesterone gel used for HRT in amenorrheic women, contrasts with findings related to use of synthetic progestins. Preliminary data suggest that vaginal progesterone can be instrumental in enhancing the notoriously poor long-term compliance of HRT.     

Evidence for in vivo primed and expanded autoreactive T cells as a specific feature of patients with type 1 diabetes

Identifying beta cell autoantigen-reactive T cells that are involved in the pathogenesis of type 1 diabetes has been troublesome for many laboratories. Disease-relevant autoreactive T cells should be in vivo Ag experienced. The aim of this study was to test this hypothesis and then use this principle as a strategy for identifying diabetes-relevant autoreactive T cells. In this study, a CSFE dilution assay was used to detect glutamic acid decarboxylase 65 (GAD65)- and insulin-responsive T cells and HLA-0201*-GAD65(114-122) pentamers were used to detect CD8(+) GAD-responsive T cells in memory CD45RO(+) and naive CD45RO(-) cell populations from patients with type 1 diabetes and healthy control subjects. T cell proliferative history was evaluated by flow cytometry telomere length measurement. CD4(+) and CD8(+) T cells specific for GAD65 and insulin were present in patients with type 1 diabetes and control subjects. Within the naive CD45RO(-) cells, CD4(+) and CD8(+) T cell responses were similar between patients and controls. Within the memory CD45RO(+) cells, CD4(+) T cell responses against whole GAD65 and insulin and HLA-0201*-GAD65(114-122) pentamer-positive CD8(+) T cells were found in patients with type 1 diabetes, but not in control subjects (p < 0.05 for all). Responding cells from the CD45RO(+) T cell population had substantially shorter telomere lengths than responding cells from the CD45RO(-) cell population. Diabetes-specific autoreactive T cells in the circulation have uniquely undergone sustained in vivo proliferation and differentiation into memory T cells. Prior selection of these cells is possible and is a way to identify diabetes-relevant target Ags and epitopes.     

Vacuolar transporters and their essential role in plant metabolism

Following the unequivocal demonstration that plants contain at least two types of vacuoles, scientists studying this organelle have realized that the plant 'vacuome' is far more complex than they expected. Some fully developed cells contain at least two large vacuoles, with different functions. Remarkably, even a single vacuole may be subdivided and fulfil several functions, which are supported in part by the vacuolar membrane transport systems. Recent studies, including proteomic analyses for several plant species, have revealed the tonoplast transporters and their involvement in the nitrogen storage, salinity tolerance, heavy metal homeostasis, calcium signalling, guard cell movements, and the cellular pH homeostasis. It is clear that vacuolar transporters are an integrated part of a complex cellular network that enables a plant to react properly to changing environmental conditions, to save nutrients and energy in times of plenty, and to maintain optimal metabolic conditions in the cytosol. An overview is given of the main features of the transporters present in the tonoplast of plant cells in terms of their function, regulation, and relationships with the microheterogeneity of the vacuome.     

A liquid chromatography-mass spectrometry method for the quantitative analysis of urinary endogenous estrogen metabolites

The ability to measure estrogen metabolites (EMs) quantitatively is important for investigating their individual roles in cancer screening, treatment and prevention, as well as in a host of other hormone-related disorders. In this protocol we describe a method that is capable of quantitating 15 distinct EMs in urine. Endogenous EMs are quantitatively measured using a liquid chromatography-tandem mass spectrometry method in which the spectrometer operates in a selected reaction monitoring mode. This method is capable of quantifying estrone and its 2-, and 4- and 16alpha-hydroxy and its 2-, 4-methoxy derivatives, and 2-hydroxyestrone-3-methyl ether; 17beta-estradiol and its 2-hydroxy, and 2- and 4-methoxy derivates, and estriol, 16-epiestriol, 17-epiestriol, and 16-ketoestradiol. The method requires only 0.5 ml of urine and approximately 60 urine samples can be quantitatively analyzed per week.     

G1 phase-dependent nucleolar accumulation of human histone H1x.

BACKGROUND INFORMATION: H1 histones are a protein family comprising several subtypes. Although specific functions of the individual subtypes could not be determined so far, differential roles are indicated by varied nuclear distributions as well as differential expression patterns of the H1 subtypes. Although the group of replication-dependent H1 subtypes is synthesized during S phase, the replacement H1 subtype, H1 degrees , is also expressed in a replication-independent manner in non-proliferating cells. Recently we showed, by protein biochemical analysis, that the ubiquitously expressed subtype H1x is enriched in the micrococcal nuclease-resistant part of chromatin and that, although it shares common features with H1 degrees , its expression is differentially regulated, since, in contrast to H1 degrees , growth arrest or induction of differentiation did not induce an accumulation of H1x. RESULTS: In the present study, we show that H1x exhibits a cell-cycle-dependent change of its nuclear distribution. This H1 subtype showed a nucleolar accumulation during the G(1) phase, and it was evenly distributed in the nucleus during S phase and G(2). Immunocytochemical analysis of the intranucleolar distribution of H1x indicated that it is located mainly in the condensed nucleolar chromatin. In addition, we demonstrate that the amount of H1x protein remained nearly unchanged during S phase progression, which is in contrast to the replication-dependent subtypes. CONCLUSION: These results suggest that the differential localization of H1x provides a mechanism for a control of H1x activity by means of shuttling between nuclear subcompartments instead of a controlled turnover of the protein.     

DNA Repair 2006: ninth biennial meeting of the German Society for Research on DNA repair

A comprehensive meeting on current aspects of DNA repair organized by, Jochen Dahm-Daphi, Ekkehard Dikomey, Alexander B_rkle, Marlis Frankenberg-Schwager, Frank Grosse, Andrea Hartwig, George Iliakis, Bernd Kaina, J_rgen Thomale, and Lisa Wiesm_ller was held in Hamburg, Germany from September 12 to 15, 2006. This article summarizes information of invited lectures and proferred papers of six plenary sessions.     

Transport of primary metabolites across the plant vacuolar membrane

Mesophyll cells and most types of storage cells harbor large central vacuoles representing the main cellular store for sugars and other primary metabolites like carboxylic- or and amino acids. The general biochemical characteristics of sugar transport across the vacuolar membrane are already known since a couple of years but only recently the first tonoplast sugar carriers have been identified on the molecular level. A candidate sucrose carrier has been identified in a proteomic approach. In Arabidopsis, the tonoplast monosaccharide transporters (TMT) represent a small protein family comprising only three members, which reside in the vacuolar membrane. Two of three tmt genes are induced upon cold, drought or salt stress and tmt knock out mutants exhibit altered monosaccharide levels upon cold induction. These observations indicate that TMT proteins represent the first examples of tonoplast sugar carriers involved in the cellular response upon osmotic stress stimuli.     

Copper conjugates of nimesulide Schiff bases targeting VEGF, COX and Bcl-2 in pancreatic cancer cells

Copper conjugates of Schiff base derivatives of nimesulide (1), a well-known cyclooxygenase-2 (COX-2) inhibitor, were synthesized, structurally characterized and evaluated for their COX selectivity indices and cytotoxicities on pancreatic tumor, BxPC-3 (COX-2 positive) and MiaPaCa (COX-2 negative) cell lines. Copper conjugates exhibit distorted square planar geometries as revealed by the single crystal X-ray structure determination of Cu(L1)(2) and show significant growth inhibition in both cell lines (IC50 values 3-26 microM for COX-2 positive and 5-9 microM for COX-2 negative cell line) than the parent nimesulide (35 microM for COX-2 positive and >100 microM for COX-2 negative cell line). The mechanistic pathway for the biological activity involves inhibition of vascular endothelial growth factor (VEGF) and COX inhibition, as well as down regulation of antiapoptotic Bcl-2 and Bcl-(XL) proteins.