Persistent but reversible coronary microvascular dysfunction after bypass grafting

The effect of coronary artery bypass grafting (CABG) on absolute myocardial blood flow (MBF) has not been investigated previously. MBF (ml. min(-1). g(-1)) was measured at rest and during hyperemia (0.56 mg/kg iv dipyridamole) using H(2)(15)O and positron emission tomography in eight patients with three-vessel disease before surgery and 1 and 6 mo after full revascularization. Baseline MBF was 0.87 +/- 0.12 preoperatively and 1.04 +/- 0.14 and 0.95 +/- 0.13 at 1 and 6 mo after CABG, respectively (P < 0.05, 6 mo vs. preoperatively). Hyperemic MBF was 1.36 +/- 0.28 preoperatively and increased to 1.98 +/- 0.50 and 2.45 +/- 0.64 at 1 and 6 mo after CABG, respectively (P < 0.01, 6 mo vs. preoperatively). Coronary vasodilator reserve (hyperemic/baseline MBF) increased from 1.59 +/- 0.40 preoperatively to 1.93 +/- 0.13 and 2.57 +/- 0.49 at 1 and 6 mo, respectively (P < 0.05, 6 mo vs. preoperatively). Minimal (dipyridamole) coronary resistance (mmHg. min. g(-1). ml(-1)) fell progressively from 59.37 +/- 14.56 before surgery to a nadir of 35. 76 +/- 10.12 at 6 mo after CABG (P < 0.01 vs. preoperatively). The results of the present study confirm that CABG improves coronary vasodilator reserve progressively as a result of reduction in minimal coronary resistance. These data suggest persistent microvascular dysfunction that recovers slowly after surgery.     

Vertical distribution of bacterial community structure in the sediments of two eutrophic lakes revealed by denaturing gradient gel electrophoresis (DGGE) and multivariate analysis techniques

Vertical distribution of bacterial community structure was investigated in the sediments of two eutrophic lakes of China, Lake Taihu and Lake Xuanwu. Profiles of bacterial communities were generated using a molecular fingerprinting technique, denaturing gradient gel electrophoresis (DGGE) followed by DNA sequence analysis, and the results were interpreted with multivariate statistical analysis. To assess changes in the genetic diversity of bacterial communities with changing depth, DGGE banding patterns were analysed by cluster analysis. Distinct clusters were recognized in different sampling stations of Lake Taihu. Canonical correspondence analysis (CCA) was carried out to infer the relationship between environmental variables and bacterial community structure. DGGE samples collected at the same sampling site clustered together in both lakes. Total phosphorus, organic matter and pH were considered to be the key factors driving the changes in bacterial community composition.     

Discovering Candidate Chromosomal Regions Linked to Kernel Size-Related Traits via QTL Mapping and Bulked Sample Analysis in Maize

Kernel size-related traits, including kernel length, kernel width, and kernel thickness, are critical components in determining yield and kernel quality in maize (Zea mays L.). Dissecting the phenotypic characteristics of these traits, and discovering the candidate chromosomal regions for these traits, are of potential importance for maize yield and quality improvement. In this study, a total of 139 F2:3 family lines derived from EHel and B73, a distinct line with extremely low ear height (EHel), was used for phenotyping and QTL mapping of three kernel size-related traits, including 10-kernel length (KL), 10-kernel width (KWid), and 10-kernel thickness (KT). The results showed that only one QTL for KWid, i.e., qKWid9 on Chr9, with a phenotypic variation explained (PVE) of 13.4% was detected between SNPs of AX-86298371 and AX-86298372, while no QTLs were detected for KL and KT across all 10 chromosomes. Four bulked groups of family lines, i.e., Groups I to IV, were constructed with F2:3 family lines according to the phenotypic comparisons of KWid between EHel and B73. Among these four groups, Group I possessed a significantly lower KWid than EHel (P = 0.0455), Group II was similar to EHel (P = 0.34), while both Group III and Group IV were statistically higher than EHel (P < 0.05). Besides, except Group IV exhibited a similar KWid to B73 (P = 0.11), KWid of Groups I to III were statistically lower than B73 (P < 0.00). By comparing the bulked genotypes of the four groups to EHel and B73, a stable chromosomal region on Chr9 between SNPs of AX-86298372 to AX-86263154, entirely covered by qKWid9, was identified to link KWid with the positive allele of increasing phenotypic effect to KWid from B73, similar to that of qKWid9. A large amount of enzyme activity and macromolecule binding-related genes were annotated within this chromosomal region, suggesting qKWid9 as a potential QTL for KWid in maize.     

Optimization of methods for peripheral blood mononuclear cells isolation and expansion of human gamma delta T cells

Human Vg9/Vδ2 T cells (γδ T cells) are immune surveillance cells both in innate and adaptive immunity and are a possible target for anticancer therapies, which can induce immune responses in a variety of cancers. Small non-peptide antigens such as zoledronate can do activation and expansion of T cells in vitro. It is evident that for adoptive cancer therapies, large numbers of functional cells are needed into cancer patients. Hence, optimization of methods needs to be carried out for the efficient expansion of these T cells. Standardization of peripheral blood mononuclear cells (PBMCs) isolation was devised. Cytokines (interleukin 2 (IL-2) and interleukin 15 (IL-15)) and zoledronate were also standardized for different concentrations. It was found that an increased number of PBMCs were recovered when washing was done at 1100 revolution per minute (rpm). Significantly high expansion fold was (2524 ± 787 expansion fold) achieved when stimulation of PBMCs was done with 1 µM of zoledronate and both cytokines IL-2 and IL-15 supported the expansion and survival of cells at the concentrations of 100 IU/ml and 10 ng/ml respectively. 14-day cultures showed highly pure (91.6 ± 5.1%) and live (96.5 ± 2.5%) expanded γδ T cells. This study aimed to standardize an easy to manipulate technique for the expansion of γδ T cells, giving a higher yield.     

Solid state production of polygalacturonase and xylanase by Trichoderma species using cantaloupe and watermelon rinds

Different solid state fermentation (SSF) sources were tested such as cantaloupe and watermelon rinds, orange and banana peels, for the production of polygalacturonase (PG) and xylanase (Xyl) by Trichoderma harzianum and Trichoderma virens. The maximum production of both PG and Xyl were obtained by T. harzianum and T. virnes grown on cantaloupe and watermelon rinds, respectively. Time course, moisture content, temperature, pH, supplementation with carbon and nitrogen sources were optimized to achieve the maximum production of both PG and Xyl of T. harzianum and T. virens using cantaloupe and watermelon rinds, respectively. The maximum production of PG and Xyl of T. harzianum and T. virens was recorded at 4–5 days of incubation, 50–66% moisture, temperature 28–35°C and pH 6–7. The influence of supplementary carbon and nitrogen sources was studied. For T. harzianum, lactose enhanced PG activity from 87 to 120 units/g solid, where starch and maltose enhanced Xyl activity from 40 to 55–60 units/g solid for T. virnes. Among the nitrogen sources, ammonium sulphate, ammonium nitrate, yeast extract and urea increased PG activity from 90 to 110–113 units/g solid for T. harzianum. Similarly, ammonium chloride, ammonium sulphate and yeast extract increased Xyl activity from 45 to 55–70 units/g solid for T. virens.     

The Effects of Selenium Supplementation on Clinical Symptoms and Gene Expression Related to Inflammation and Vascular Endothelial Growth Factor in Infertile Women Candidate for In Vitro Fertilization

Biological Trace Element Research - This study was performed to determine the effects of selenium supplementation on clinical symptoms and gene expression related to inflammatory markers in...     

The investigation of the G-quadruplex aptamer selectivity to Pb2+ ion: a joint molecular dynamics simulation and density functional theory study

Abstract

The aptamers with the ability to form a G-quadruplex structure can be stable in the presence of some ions. Hence, study of the interactions between such aptamers and ions can be beneficial to determine the highest selective aptamer toward an ion. In this article, molecular dynamics (MD) simulations and quantum mechanics (QM) calculations have been applied to investigate the selectivity of the T30695 aptamer toward Pb²⁺ in comparison with some ions. The Free Energy Landscape (FEL) analysis indicates that Pb²⁺ has remained inside the aptamer during the MD simulation, while the other ions have left it. The Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) binding energies prove that the conformational stability of the aptamer is the highest in the presence of Pb²⁺. According to the compaction parameters, the greatest compressed ion-aptamer complex, and hence, the highest ion-aptamer interaction have been induced in the presence of Pb²⁺. The contact maps clarify the closer contacts between the nucleotides of the aptamer in the presence of Pb²⁺. The density functional theory (DFT) results show that Pb²⁺ forms the most stable complex with the aptamer, which is consistent with the MD results. The QM calculations reveal that the N-H bonds and the O…H distances are the longest and the shortest, respectively, in the presence of Pb²⁺. The obtained results verify that the strongest hydrogen bonds (HBs), and hence, the most compressed aptamer structure are induced by Pb²⁺. Besides, atoms in molecules (AIM) and natural bond orbital (NBO) analyses confirm the results.

Communicated by Ramaswamy H. Sarma     

Jelly-falls historic and recent observations: a review to drive future research directions

The biological pump describes the transport of particulate matter from the sea surface to the ocean’s interior including the seabed. The contribution by gelatinous zooplankton bodies as particulate organic matter (POM) vectors (“jelly-falls”) has been neglected owing to technical and spatiotemporal sampling limitations. Here, we assess the existing evidence on jelly-falls from early ocean observations to present times. The seasonality of jelly-falls indicates that they mostly occur after periods of strong upwelling and/or spring blooms in temperate/subpolar zones and during late spring/early summer. A conceptual model helps to define a jelly-fall based on empirical and field observations of biogeochemical and ecological processes. We then compile and discuss existing strategic and observational oceanographic techniques that could be implemented to further jelly-falls research. Seabed video- and photography-based studies deliver the best results, and the correct use of fishing techniques, such as trawling, could provide comprehensive regional datasets. We conclude by considering the possibility of increased gelatinous biomasses in the future ocean induced by upper ocean processes favouring their populations, thus increasing jelly-POM downward transport. We suggest that this could provide a “natural compensation” for predicted losses in pelagic POM with respect to fuelling benthic ecosystems.     

Bi-directional PCR allele-specific amplification (bi-PASA) for detection of caspase-8 -652 6N ins/del promoter polymorphism (rs3834129) in breast cancer

Caspase-8 (CASP8) plays a critical role in regulating apoptosis, and its functional polymorphisms may modify cancer risk. We investigated the possible association between CASP8 -652 6N ins/del (rs3834129) and the risk of breast cancer in a sample of Iranian population. This case-control study was done on 236 breast cancer patients and 203 cancer free healthy female. We designed a rapid and simple bi-directional PCR allele-specific amplification (bi-PASA) for detection of CASP8 -652 6N ins/del polymorphism. The results showed that the CASP8 -652 6N del/dl genotype was inversely associated with breast cancer risk (OR=0.33, 95% CI=0.17-0.65, p=0.001). The frequencies of the del allele in cases and controls were 29.1% and 38.6%, respectively. An inverse association between CASP8 6N del variant and the risk of breast cancer (OR=0.66, 95% CI=0.66-0.87, p=0.002) was found. In conclusion, the result suggests that the CASP8 -652 6N del polymorphism plays a protective role in susceptibility to breast cancer in our population. Further studies in other populations with larger samples are needed to confirm these findings.     

The potential therapeutic use of stem cells in cartilage repair

As our population demographics change, osteoarthritis and cartilage defects are becoming more prevalent. The discovery of stems cells and their ability for indefinite regeneration has revolutionised the way cartilage problems are viewed. Tissue engineering has been shown to be the ideal way of repairing articular cartilage lesions, i.e. back to native tissue. Cartilage is an ideal tissue engineering target as it is avascular, aneural and alymphatic. The two main types of stem cells being investigated in chondrogenesis are embryological and mesenchymal stem cells. Research into embryological stem cells has been surrounded by controversy because of ethical, religious and social concerns. We discuss the use of embryological and mesenchymal stem cells in cartilage repair and the various factors involved in the differentiation into chondrocytes. We also discuss commonly used mesenchymal stem cell markers and their limitations.