Multi-user interference mitigation under limited feedback requirements for WCDMA systems with base station cooperation

One of the techniques that has been recently identified for dealing with multi-user interference (MUI) in future communications systems is base station (BS) cooperation or joint processing. However, perfect MUI cancellation with this technique demands severe synchronization requirements, perfect and global channel state information (CSI), and an increased backhaul and signaling overhead. In this paper, we consider a more realistic layout with the aim of mitigating the MUI, where only local CSI is available at the BSs. Due to synchronization inaccuracies and errors in the channel estimation, the system becomes partially asynchronous. In the downlink of wideband code division multiple access based systems, this asynchronism stands for the loss of the orthogonality of the spreading codes allocated to users and thus, for an increase in the MUI level of the system. In this contribution, we propose a framework for mitigating the MUI which builds in three main steps: definition of a cooperation area based on the channel characteristics, statistical modeling of the average MUI power experienced by each user and a specific spreading code allocation scheme for users served with joint processing. This code allocation assigns spreading codes to users in such a way that minimum average cross-correlation between active users can be achieved. Interestingly, these steps can be performed with a limited amount of extra feedback from the user's side

Immunohistochemical evaluation of cell proliferation and apoptosis markers in ovaries and uterus of tamoxifen-treated rats

WOS: 000252208100023PubMed ID: 17466037The aim of the study was to evaluate the immunohistochemical expression of cell proliferation and apoptosis markers in the ovaries and uterus of tamoxifen-treated rats. Twelve rats (150-200 g) were divided into two equal groups. The study group received daily intraperitoneal injections of tamoxifen dissolved in 5% dimethyl sulfoxide (n = 6). The control group received only the vehicle (n = 6). The rats were sacrificed at the 20th day of injection and were perfused. The ovaries and uterus of the rats were extracted. The sections were immunohistochemically stained with cell proliferation marker Ki-67 and the apoptosis markers PTEN and CD95. The expressions of the markers were quantified by a semiquantitative H-score method in myometrium, endometrial glands, ovarian surface epithelium, ovarian follicles, corpus luteum, and ovarian stroma separately. The mean H-scores of CD95 and PTEN obtained from myometrium, glandular endometrium, ovarian surface epithelium, ovarian follicles, corpus luteum, and ovarian stroma did not show significant difference between the study and the control groups. Proliferative index (Ki-67) of endometrial glands was significantly higher in the study group than in the control group (P < 0.05). In addition, proliferative index (Ki-67) of corpus luteum was significantly higher in the study group than in the control group (P < 0.05). Tamoxifen treatment has a potential to stimulate the cell proliferation of endometrial glands and corpus luteum in tamoxifen-treated rats. Apoptosis markers of PTEN and CD95 did not demonstrate significant difference after the tamoxifen treatment

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

Congenital cystic adenomatoid malformation type 4 and aneurysm of the vein of Galen: a rare coincidence or possibly related association.

As far as the prognosis is concerned, it is important to diagnose the exact type of congenital cystic adenomatoid malformation (CCAM) in order to exclude associated anomalies, as well as the risk of development of malignancies in later life. The frequency of associated malformations of CCAM type 4 is unknown. We report a 4-month-old boy with CCAM type 4 and aneurysmal malformation of the vein of Galen (AVG). Although AVG is the most frequent arteriovenous malformation during childhood, this is the first case report, to our knowledge, of CCAM type 4 in association with an anomaly. In addition, we speculate that the relation between CCAM type 4 and AVG appears to be more likely a possibly related association rather than a rare coincidence, as both malformations develop at the same stages of embryonic life, and pathogenetically, apoptosis play a significant role in both entities. However, further studies are needed to validate this speculation placing emphasis on the association of the two anomalies, otherwise a rare coincidence cannot be excluded

Expression of Bcl-2, Bax and p53 proteins in pituitary adenomas: an immunohistochemical study.

Aims and background: Although pituitary adenomas are usually benign lesions, their growth rate is highly variable and unpredictable. Apoptosis appears to be an important process in neoplastic lesions. The purpose of this study was to investigate the expression of apoptosis-related proteins including Bcl-2, bax and p53 in pituitary adenomas and its correlation with hormone function, tumor size, local control, and proliferative activity