101 research outputs found
Saving Lives: The Principle of Distinction and the Realities of Modern War
WOS: 000332942700005PubMed ID: 24778561In this study, we assessed the feasibility of fetal RhD genotyping by analysis of cell-free fetal DNA(cffDNA) extracted from plasma samples of Rhesus (Rh) D-negative pregnant women by using real-time polymerase chain reaction (PCR). Fetal genotyping was performed on 30 RhD-negative women between 9 and 39 weeks of gestation who were referred to us for invasive testing [amniocentesis/chorionic villi sampling (CVS)]. The fetal RHD genotype was determined based on real-time PCR method. Exons 7 and 10 of the RHD and SRY genes were targeted. Among the pregnant women, 12 were carrying male and 17 were carrying female fetuses. Out of 29 pregnant women, 21 had RhD-positive and nine had RhD-negative fetuses. One sample) case 12, whose blood group was found to be AB Rh [+] (was excluded due to controversial results from repeated serological analyses. All prenatal results were in concordance with postnatal RhD status and fetal sex without false-positive or -negative results. Performing real-time PCR on cffDNA showed accurate, efficient and reliable results, allowing rapid and high throughput non invasive determination of fetal sex and RhD status in clinical samples
Electric-Field Breakdown of Absolute Negative Conductivity and Supersonic Streams in Two-Dimensional Electron Systems with Zero Resistance/Conductance States
We calculate the current-voltage characteristic of a two-dimensional electron
system (2DES) subjected to a magnetic field at strong electric fields. The
interaction of electrons with piezoelectric acoustic phonons is considered as a
major scattering mechanism governing the current-voltage characteristic. It is
shown that at a sufficiently strong electric field corresponding to the Hall
drift velocity exceeding the velocity of sound, the dissipative current
exhibits an overshoot. The overshoot of the dissipative current can result in a
breakdown of the absolute negative conductivity caused by microwave irradiation
and, therefore, substantially effect the formation of the domain structures
with the zero-resistance and zero-conductance states and supersonic electron
streams.Comment: 5 pages, 4 figure
Genome-Wide Transcriptional Reorganization Associated with Senescence-to-Immortality Switch during Human Hepatocellular Carcinogenesis
Cataloged from PDF version of article.Senescence is a permanent proliferation arrest in response to cell stress such as DNA damage. It contributes strongly to tissue aging and serves as a major barrier against tumor development. Most tumor cells are believed to bypass the senescence barrier (become "immortal") by inactivating growth control genes such as TP53 and CDKN2A. They also reactivate telomerase reverse transcriptase. Senescence-to-immortality transition is accompanied by major phenotypic and biochemical changes mediated by genome-wide transcriptional modifications. This appears to happen during hepatocellular carcinoma (HCC) development in patients with liver cirrhosis, however, the accompanying transcriptional changes are virtually unknown. We investigated genome-wide transcriptional changes related to the senescence-to-immortality switch during hepatocellular carcinogenesis. Initially, we performed transcriptome analysis of senescent and immortal clones of Huh7 HCC cell line, and identified genes with significant differential expression to establish a senescence-related gene list. Through the analysis of senescence-related gene expression in different liver tissues we showed that cirrhosis and HCC display expression patterns compatible with senescent and immortal phenotypes, respectively; dysplasia being a transitional state. Gene set enrichment analysis revealed that cirrhosis/senescence-associated genes were preferentially expressed in non-tumor tissues, less malignant tumors, and differentiated or senescent cells. In contrast, HCC/immortality genes were up-regulated in tumor tissues, or more malignant tumors and progenitor cells. In HCC tumors and immortal cells genes involved in DNA repair, cell cycle, telomere extension and branched chain amino acid metabolism were up-regulated, whereas genes involved in cell signaling, as well as in drug, lipid, retinoid and glycolytic metabolism were down-regulated. Based on these distinctive gene expression features we developed a 15-gene hepatocellular immortality signature test that discriminated HCC from cirrhosis with high accuracy. Our findings demonstrate that senescence bypass plays a central role in hepatocellular carcinogenesis engendering systematic changes in the transcription of genes regulating DNA repair, proliferation, differentiation and metabolism
Differential expression of Caveolin-1 in hepatocellular carcinoma: correlation with differentiation state, motility and invasion
WOS: 000264914000001PubMed ID: 19239691Turkish Scientific and Technological Research Council (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [SBAG-107S026]; Dokuz Eylul University Research FoundationDokuz Eylul University [05.KB.SAG.071]We thank Prof. Mehmet Ozturk for providing us HCC cell lines and for his critical reading of the manuscript; and Prof. Aykut Uren for his helpful discussions on the manuscript. We also thank to Evin Ozen for her technical assistance. This work was supported by grants to Nese ATABEY from the Turkish Scientific and Technological Research Council (TUBITAK, SBAG-107S026) and Dokuz Eylul University Research Foundation (05.KB.SAG.071)
The expression of HSP60 and HSP10 in large bowel carcinomas with lymph node metastase
BACKGROUND: The involvement of Heat Shock Proteins (HSP) in cancer development and progression is a widely debated topic. The objective of the present study was to evaluate the presence and expression of HSP60 and HSP10 in a series of large bowel carcinomas and locoregional lymph nodes with and without metastases. METHODS: 82 Astler and Coller's stage C2 colorectal cancers, of which 48 well-differentiated and 34 poorly-differentiated, were selected along with 661 lymph nodes, including 372 with metastases and 289 with reactive hyperplasia only, from the same tumours. Primitive tumours and both metastatic and reactive lymph nodes were studied; specifically, three different compartments of the lymph nodes, secondary follicle, paracortex and medullary sinus, were also analysed. An immunohistochemical research for HSP60 and HSP10 was performed and the semiquantitative results were analysed by statistical analysis to determine the correlation between HSPs expression and 1) tumour grading; 2) degree of inflammation; 3) number of lymph nodes involved; 4) lymph node compartment hyperplasia. Moreover, western blotting was performed on a smaller group of samples to confirm the immunohistochemical results. RESULTS: Our data show that the expression of HSP60, in both primary tumour and lymph node metastasis, is correlated with the tumoral grade, while the HSP10 expression is not. Nevertheless, the levels of HSP10 are commonly higher than the levels of HSP60. In addition, statistical analyses do not show any correlation between the degree of inflammation and the immunopositivity for both HSP60 and HSP10. Moreover, we find a significant correlation between the presence of lymph node metastases and the positivity for both HSP60 and HSP10. In particular, metastatic lymph nodes show a higher percentage of cells positive for both HSP60 and HSP10 in the secondary follicles, and for HSP10 in the medullary sinuses, when compared with hyperplastic lymph nodes. CONCLUSION: HSP60 and HSP10 may have diagnostic and prognostic significance in the management of this tumour and their overexpression in tumoral cells may be functionally related to tumoral progression. We hypothesise that their expression in follicular and medullary cells of lymph nodes may be induced by formation of metastases. Further studies based on these observations could lead to a better understanding of the HSPs involvement in colorectal cancer progression, as well as other neoplasms
Expression of transforming growth factor-beta-1 and p27Kip1 in pancreatic adenocarcinomas: relation with cell-cycle-associated proteins and clinicopathologic characteristics
Altered IGF-I receptor expression in chorioamniotic cells in premature fetal membranes
WOS: 000222167800016PubMed ID: 15283060OBJECTIVE: To investigate the presence and distribution of type I insulinlike growth factor receptor (IGF-IR) in the cells of the chorioamniotic membrane and to search for any alterations occurring in IGF-IR expression in premature rupture of membranes (PROM) patients. STUDY DESIGN: Fetal membranes collected at delivery from 42 pregnancies between 36 and 40 gestational weeks were included in the study. Seventeen of 42 cases had premature rupture of membranes, and 25 cases had intact membranes prior to delivery. Paraffin sections of the fetal membranes were stained with IGF-IR antibody by the streptavidin-biotin-immunoperoxidase method. The staining was scored and compared statistically between PROM and control cases. RESULTS: The fetal membranes of PROM cases had significantly reduced IGF-IR expression in chorionic trophoblastic cells when compared with the control group (P =.006, chi(2)). CONCLUSION: Our immunohistochemical findings revealed that changes in IGF-IR levels in chorionic amniotic cells may play a pathogenetic role in PROM cases, but the mechanism is speculative and needs further investigation
Altered IGF-I receptor expression in chorioamniotic cells in premature rupture of fetal membranes
PubMed ID: 15283060OBJECTIVE: To investigate the presence and distribution of type I insulinlike growth factor receptor (IGF-IR) in the cells of the chorioamniotic membrane and to search for any alterations occurring in IGF-IR expression in premature rupture of membranes (PROM) patients. STUDY DESIGN: Fetal membranes collected at delivery from 42 pregnancies between 36 and 40 gestational weeks were included in the study. Seventeen of 42 cases had premature rupture of membranes, and 25 cases had intact membranes prior to delivery. Paraffin sections of the fetal membranes were stained with IGF-IR antibody by the streptavidin-biotin-immunoperoxidase method. The staining was scored and compared statistically between PROM and control cases. RESULTS: The fetal membranes of PROM cases had significantly reduced IGF-IR expression in chorionic trophoblastic cells when compared with the control group (P=.006, ? 2). CONCLUSION: Our immunohistochemical findings revealed that changes in IGF-IR levels in chorionic amniotic cells may play a pathogenetic role in PROM cases, but the mechanism is speculative and needs further investigation
Role of apoptosis, bcl-2 and bax protein expression in premature rupture of fetal membranes
WOS: 000178826800002PubMed ID: 12418062OBJECTIVE: To examine the degree of apoptosis in human fetal membranes associated with premature rupture Of membranes (PROM) as compared with normal pregnancies and to evaluate the expression of proapoptotic bax and antiapoptotic bcl-2 gene products. STUDY DESIGN: Fetal membranes from 50 pregnancies were included in the study. Thirty of 50 pregnancies had PROM. Twenty pregnancies with intact membranes served as controls. Chorioamniotic membrane biopsies were taken from the rupture site of the membrane and periphery of the rupture side. In the control group, membrane biopsies were taken from the artificial rupture site, cervical pole of the membranes and, membranes close to the edge of the placenta. In recognizing apoptotic figures, routinely processed samples were stained with hematoxylin and eosin for light microscopic evaluation. Quantification of the apoptotic cells was performed with high-power fields and expressed as the number per 100 cells. The membranes of both groups were then stained with bcl-2 and bax antibodies by using the standard steptavidin-biotin-immunoperoxidase method. Staining with both antibodies were compared between two groups. RESULTS: Apoptotic cells were detected in the amniotic epithelium, in chorionic cells and fibroblastic layer of the fetal membranes. Apoptotic cells were found mostly in the chorionic cells. There was a statistically significant difference between the apoptotic index in PROM and the control group in both rupture and peripheral sites (P<.05), although within each group peripheral and rupture sites showed no difference in terms of apoptotic cell counts. Both bax and bcl-2 expression was observed in 40% of control cases and in 57% and 50% of cases with PROM, respectively, mostly in the chorionic trophoblastic cells. The PROM and control groups showed no statistically significant difference in terms of bcl-2 and bax protein expression. CONCLUSION: Apoptosis may play a role in the pathogenesis of PROM, but the changes in apoptosis do not seem to be mediated by bcl-2 and bax genes in the amniotic membrane. Other regulatory mechanisms must be investigated
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