1,991 research outputs found
The correlation between telomerase activity and BaX/BcL-2 ratio in valproic acid-treated MCF-7 breast cancer cell line
Objective(s): Valproic acid (VPA), a drug used in the treatment of neurological disorders, has been shown to have cytotoxic effects on cancer cells through different mechanisms. Telomerase, a ribonucleoprotein reverse transcriptase, is responsible for elongation of the telomere and is activated in cancers. A relation between telomerase activity and resistance to apoptosis has been established. This study focused on probable effects of VPA on MCF-7 cancer cells. In particular, we investigated VPA effects on viability, apoptosis and telomerase activity. Materials and Methods: Cytotoxicity effects of VPA on MCF-7 cells were determined by neutral red uptake assay. Cells were treated with different concentrations of VPA (0-32 mM) and telomerase activity and Bax and Bcl-2 protein levels were determined using TRAP assay (PCR-ELISA) method and ELISA method, respectively. Results: The cytotoxic effects of different concentration of VPA on MCF-7 cells were observed as a reduction in cell viability and telomerase activity and altered expression of Bcl-2 family protein levels. The results also showed that there is a significant correlation between reduction of telomerase activity and increase in Bax/Bcl-2 ratio (P=0.001). Conclusion: Our study demonstrated that cell viability of MCF-7 cells was decreased after treatment with VPA, probably through a reduction of telomerase activity and an increase in Bax/bcl-2 ratio. Therefore, it could be concluded that VPA is a potent anti-cancer agent for breast cancer cells through inhibition of telomerase activity and induction of apoptosis. © 2015, Mashhad University of Medical Sciences. All rights reserved
Impact of ethnicity upon body composition assessment in Iranian northern children
Objective: This study was designed to determine secular growth among rural children between two ethnic groups (Sisstanish and Non-Sisstanish ) in north of Iran. Methods: We chose 20 villages from 118 by cluster and simple sampling. All of 25-60 months old children in this area were considered in this study. Sample size was 1569 cases (632=Sisstanish and 937=Non- Sisstanish). Height, weight and personal identification were recorded by questioner. BMI percentile and under -1sd, -2sd and -3sd from NCHS were used for comparison. X2 test and T.test were used to analyze by software SPSS. Results: Sisstanish children were 900 g lighter and 4.39 cm taller than non-Sisstanish among all of age groups. T.test is significant between two groups based on weight and height (P<0.05). Stunting and underweight were observed in Sisstanish group 23% and 5.9% respectively more than in non-Sisstanish by -2sd criterion. There is a significant difference between two groups by stunting (P<0.05). Overweight (1.52%) and obesity (12.4%) were shown in Sisstanish group more than in non-Sisstanish group and Statistical differences is significant between them based on obesity (P<0.05). Conclusion: Secular growth in two groups is disproportionate and in Non-Sisstanish group is better than Sisstanish group. Sisstanish children suffer from severe height deficit and BMI high. Thereby, malnutrition is the most health problem in rural area in the north of Iran and nutritional intervention is necessary for solving these problems
The Capacity of Three-Receiver AWGN Broadcast Channels with Receiver Message Side Information
This paper investigates the capacity region of three-receiver AWGN broadcast
channels where the receivers (i) have private-message requests and (ii) know
the messages requested by some other receivers as side information. We classify
these channels based on their side information into eight groups, and construct
different transmission schemes for the groups. For six groups, we characterize
the capacity region, and show that it improves both the best known inner and
outer bounds. For the remaining two groups, we improve the best known inner
bound by using side information during channel decoding at the receivers.Comment: This is an extended version of the same-titled paper submitted to
IEEE International Symposium on Information Theory (ISIT) 201
Double point self-intersection surfaces of immersions
A self-transverse immersion of a smooth manifold M^{k+2} in R^{2k+2} has a
double point self-intersection set which is the image of an immersion of a
smooth surface, the double point self-intersection surface. We prove that this
surface may have odd Euler characteristic if and only if k is congruent to 1
modulo 4 or k+1 is a power of 2. This corrects a previously published result by
Andras Szucs.
The method of proof is to evaluate the Stiefel-Whitney numbers of the double
point self-intersection surface. By earier work of the authors these numbers
can be read off from the Hurewicz image h(\alpha ) in H_{2k+2}\Omega ^{\infty
}\Sigma ^{\infty }MO(k) of the element \alpha in \pi _{2k+2}\Omega ^{\infty
}\Sigma ^{\infty }MO(k) corresponding to the immersion under the
Pontrjagin-Thom construction.Comment: 22 pages. Published copy, also available at
http://www.maths.warwick.ac.uk/gt/GTVol4/paper4.abs.htm
Optimal Coding Schemes for the Three-Receiver AWGN Broadcast Channel with Receiver Message Side Information
This paper investigates the capacity region of the three-receiver AWGN
broadcast channel where the receivers (i) have private-message requests and
(ii) may know some of the messages requested by other receivers as side
information. We first classify all 64 possible side information configurations
into eight groups, each consisting of eight members. We next construct
transmission schemes, and derive new inner and outer bounds for the groups.
This establishes the capacity region for 52 out of 64 possible side information
configurations. For six groups (i.e., groups 1, 2, 3, 5, 6, and 8 in our
terminology), we establish the capacity region for all their members, and show
that it tightens both the best known inner and outer bounds. For group 4, our
inner and outer bounds tighten the best known inner bound and/or outer bound
for all the group members. Moreover, our bounds coincide at certain regions,
which can be characterized by two thresholds. For group 7, our inner and outer
bounds coincide for four members, thereby establishing the capacity region. For
the remaining four members, our bounds tighten both the best known inner and
outer bounds.Comment: Authors' final version (to appear in IEEE Transactions on Information
Theory
Coding Schemes for a Class of Receiver Message Side Information in AWGN Broadcast Channels
This paper considers the three-receiver AWGN broadcast channel where the
receivers (i) have private-message requests and (ii) know some of the messages
requested by other receivers as side information. For this setup, all possible
side information configurations have been recently classified into eight groups
and the capacity of the channel has been established for six groups (Asadi et
al., ISIT 2014). We propose inner and outer bounds for the two remaining
groups, groups 4 and 7. A distinguishing feature of these two groups is that
the weakest receiver knows the requested message of the strongest receiver as
side information while the in-between receiver does not. For group 4, the inner
and outer bounds coincide at certain regions. For group 7, the inner and outer
bounds coincide, thereby establishing the capacity, for four members out of all
eight members of the group; for the remaining four members, the proposed bounds
reduce the gap between the best known inner and outer bounds.Comment: accepted and to be presented at the 2014 IEEE Information Theory
Workshop (ITW
A Unified Scheme for Two-Receiver Broadcast Channels with Receiver Message Side Information
This paper investigates the capacity regions of two-receiver broadcast
channels where each receiver (i) has both common and private-message requests,
and (ii) knows part of the private message requested by the other receiver as
side information. We first propose a transmission scheme and derive an inner
bound for the two-receiver memoryless broadcast channel. We next prove that
this inner bound is tight for the deterministic channel and the more capable
channel, thereby establishing their capacity regions. We show that this inner
bound is also tight for all classes of two-receiver broadcast channels whose
capacity regions were known prior to this work. Our proposed scheme is
consequently a unified capacity-achieving scheme for these classes of broadcast
channels.Comment: accepted and to be presented at the 2015 IEEE International Symposium
on Information Theory (ISIT 2015
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