68 research outputs found
Natural genetic variation in Calligonum Tunisian genus analyzed by RAPD markers
The Calligonum genus is one of the most economically important resources of the Tunisian desert, playing an important role in the lives of desert local population. A great range of genetic diversity could be seen in diverse populations of this genus which are spread all over Tunisian areas. DNA-based molecular markers are playing increasingly important role in the analysis of genetic diversity in wide range of plants. This study is an attempt to collect, compile and collate information on the existing natural genetic diversity, at intra-specific and inter-populational levels in Calligonum genus (C.azel, C.arich and C.comosum). This study deals with 16 genotypes of Calligonum (Polygonaceae) collected from different regions of Tunisian desert using random amplified polymorphic DNA (RAPD) marker. In total, 46 polymorphic bands amplified by 4 random primers, with the polymorphic rate of 89.06% were recorded. The commercial software package SPSS 16 was used to develop similar matrices based on the Dice coefficient which is defined as 2a/2a+u, where “a” is the number of positive matches and “u” is the number of non-matches. From the analysis, it is imperative that predominantly obligate out breeding behavior of Calligonum genus, helps these diverse accessions to spread and occupy specific geographical niches in the Tunisian arid regions.Key words: Calligonum, genetic diversity, Inter-specific variation, RAPD marker, Tunisian desert
The Role and Therapeutic Potential of miRNAs in Colorectal Liver Metastasis
Colorectal cancer (CRC) is the fourth leading cause of cancer-related deaths worldwide. Liver metastasis is the major cause of CRC patient mortality, occurring in 60% patients with no effective therapies. Although studies have indicated the role of miRNAs in CRC, an in-depth miRNA expression analysis is essential to identify clinically relevant miRNAs and understand their potential in targeting liver metastasis. Here we analyzed miRNA expressions in 405 patient tumors from publicly available colorectal cancer genome sequencing project database. Our analyses showed miR-132, miR-378f, miR-605 and miR-1976 to be the most significantly downregulated miRNAs in primary and CRC liver metastatic tissues, and CRC cell lines. Observations in CRC cell lines indicated that ectopic expressions of miR-378f, -605 and -1976 suppress CRC cell proliferation, anchorage independent growth, metastatic potential, and enhance apoptosis. Consistently, CRC patients with higher miR-378f and miR-1976 levels exhibited better survival. Together, our data suggests an anti-tumorigenic role of these miRNAs in CRC and warrant future in vivo evaluation of the molecules for developing biomarkers or novel therapeutic strategies
Maternal and neonatal outcome in pregnancy with previous lower segment caesarean section undergoing trial of scar
Background: Women with previous LSCS often have to make a decision about mode of delivery of their second baby. As the rate of caesarean section is continuously increasing, vaginal birth after caesarean section (VBAC) is a good strategy to decrease caesarean rate. The present study was planned to assess the fetomaternal outcome in pregnancies with previous lower segment caesarean section undergoing trial of scar and to identify the factors, which can influence the outcome of trial of scar.Methods: This was a prospective observational study on 100 patients at a tertiary care institute. Pregnant women with previous LSCS were selected randomly for the study on the basis of the inclusion and exclusion criteria. Each labor monitored closely using a partogram. Decision for repeat emergency caesarean was taken by consultant. All women included in the study were followed through delivery and till discharge.Results: Out of 100 pregnant women 49 % cases had successful VBAC, 50% had emergency caesarean and one patient had laparotomy for rupture uterus. In women, who also had a prior vaginal delivery, 72% delivered vaginally, as compared to 40% of the women who did not undergo prior vaginal delivery (p value=0.003). Women who were in spontaneous labor, 59.21% delivered vaginally, whereas women who were induced, 16.6% delivered vaginally. The rate of perinatal complication was more in the patients who required an emergency CS after a failed trial. Conclusions: Our findings may encourage obstetricians to encourage VBAC in the properly screened ANC patients and decrease the rate of recommending caesarean section
Blue light effects on rose photosynthesis and photomorphogenesis
Through its impact on photosynthesis and morphogenesis, light is the environmental factor that most affects plant architecture. Using light rather than chemicals to manage plant architecture could reduce the impact on the environment. However, the understanding of how light modulates plant architecture is still poor and further research is needed. To address this question, we examined the development of two rose cultivars, Rosa hybrida‘Radrazz’ and Rosa chinensis‘Old Blush’, cultivated under two light qualities. Plants were grown from one-node cuttings for 6 weeks under white or blue light at equal photosynthetic efficiencies. While plant development was totally inhibited in darkness, blue light could sustain full development from bud burst until flowering. Blue light reduced the net CO2 assimilation rate of fully expanded leaves in both cultivars, despite increasing stomatal conductance and intercellular CO2 concentrations. In ‘Radrazz’, the reduction in CO2 assimilation under blue light was related to a decrease in photosynthetic pigment content, while in both cultivars, the chl a/b ratio increased. Surprisingly, blue light could induce the same organogenetic activity of the shoot apical meristem, growth of the metamers and flower development as white light. The normal development of rose plants under blue light reveals the strong adaptive properties of rose plants to their light environment. It also indicates that photomorphogenetic processes can all be triggered by blue wavelengths and that despite a lower assimilation rate, blue light can provide sufficient energy via photosynthesis to sustain normal growth and development in roses
Thermal stability of the essential oils isolated from Tunisian Thymus capitatus Hoff. et Link.: Effect on the chemical composition and the antioxidant and antibacterial activities
The chemical composition, the antioxidant and the antibacterial activities of essential oils, isolated from the aerial parts of Tunisian Thymus capitatus during the flowering phase, and stored in the dark during 37 days in the oven, at 60 degrees C were evaluated. Samples taken periodically were used to evaluate the chemical composition, the antioxidant and the antibacterial activities. With some fluctuations, carvacrol (68-74%) was the major component of the oil independent of the storage period. alpha-Terpinene and gamma-terpinene decreased over time, whereas p-cymene increased in the same period. Despite the thirty-seven days of storage at 60 degrees C, T. capitatus essential oil still showed high antioxidant and stable antimicrobial activity
Hybrid case‑base maintenance approach for modeling large scale case‑based reasoning systems
YesCase-based reasoning (CBR) is a nature inspired paradigm of machine learning capable
to continuously learn from the past experience. Each newly solved problem and its
corresponding solution is retained in its central knowledge repository called case-base.
Withρ the regular use of the CBR system, the case-base cardinality keeps on growing.
It results into performance bottleneck as the number of comparisons of each new
problem with the existing problems also increases with the case-base growth. To
address this performance bottleneck, different case-base maintenance (CBM) strategies are used so that the growth of the case-base is controlled without compromising
on the utility of knowledge maintained in the case-base. This research work presents
a hybrid case-base maintenance approach which equally utilizes the benefits of case
addition as well as case deletion strategies to maintain the case-base in online and
offline modes respectively. The proposed maintenance method has been evaluated
using a simulated model of autonomic forest fire application and its performance has
been compared with the existing approaches on a large case-base of the simulated
case study.Authors acknowledge the internal funding support received from Namal College Mianwali to complete the research work
Pathophysiological role of microRNA-29 in pancreatic cancer stroma
poster abstractBackground: Dense fibrotic stroma associated with pancreatic ductal adenocarcinoma
(PDAC) has been a major obstacle for drug delivery to the tumor bed and may impede
attempts to slow down PDAC progression and metastasis. However, current antistromal
drugs have not improved tumor response to chemotherapy or patient survival.
Thus, a better understanding of the molecular mechanisms associated with tumorstromal
interactions is desperately needed to develop novel anti-stromal therapeutic
approaches. MicroRNAs (miRNAs) are an abundant class of highly conserved, small
non-coding RNAs that function as key regulators of eukaryotic gene expression and
cellular homeostasis. miR-29 is known to play a paramount role in the fibrotic process of
several organs by providing crucial functions downstream of pro-fibrotic signaling
pathways such as TGF-β1 and regulates the expression of extracellular matrix (ECM)
proteins, a major component in the PDAC stroma. Upregulation of TGF-β1 is associated
with PDAC pathogenesis and is known to activate stromal cells. Furthermore, vascular
endothelial growth factor (VEGF) that stimulates tumor angiogenesis is a predicted
target of miR-29. We hypothesize that miR-29 may be misregulated in TGF-β1 activated
PDAC stromal cells and lead to excessive accumulation of ECM proteins and VEGF.
Kwon et al. 2015 Annual AACR Meeting Restored expression of miR-29 could be therapeutically beneficial to modulate tumorstromal interactions.
Methods: Northern blot or qPCR techniques were used to assess miR-29 levels in vitro
stromal cells, murine PDAC model, and PDAC patient biopsies, and stromal
deposition/fibrosis was determined by Sirius red staining. In murine and human PDAC
samples, stromal specific miR-29 expression was determined via in situ hybridization by
co-staining pancreatic tissues with glial fibrillary acidic protein a marker for stromal cells
and miR-29. miR-29 functional studies were conducted by transfection of stroma cells
with synthetic miR-29 mimics and locked nucleic acid, a miR-29 inhibitor, and ECM
protein/VEGF expression was analyzed by western blot analysis. The effect of miR-29
overexpression in stromal cells on cancer colony growth was evaluated by direct coculture
of stromal cells ectopically expressing miR-29 with pancreatic cancer cells, and
subsequently, cancer colony number and stromal accumulation was determined by
crystal violet and sirius red stains respectively.
Results: In both in vitro and in vivo models as well as PDAC patient biopsies, we
observed loss of miR-29 is a common phenomenon of activated stromal cells, and is
associated with a significant increase in ECM and VEGF accumulation. Restored
expression of miR-29 in stromal cells reduced the deposition of matrix proteins, VEGF
expression, and cancer colony formation in direct co-culture.
Conclusion: These results provide insight into the mechanistic role of miR-29 in PDAC
stroma and its potential use as an anti-stromal/angiogenic therapeutic agent
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Indexação morfossemântica de imagens no contexto da saúde visando à recuperação de informações
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