Unstimulated primary CD4+ T cells from HIV-1-positive elite suppressors are fully susceptible to HIV-1 entry and productive infection

Elite controllers or suppressors (ES) are a group of HIV-1-infected individuals who maintain viral loads below the limit of detection of commercial assays for many years. The mechanisms responsible for this remarkable control are under intense study, with the hope of developing therapeutic vaccines effective against HIV-1. In this study, we addressed the question of the intrinsic susceptibility of ES CD4(+) T cells to infection. While we and others have previously shown that CD4(+) T cells from ES can be infected by HIV-1 isolates in vitro, these studies were confounded by exogenous activation and in vitro culture of CD4(+) T cells prior to infection. In order to avoid the changes in chemokine receptor expression that have been associated with such exogenous activation, we infected purified CD4(+) T cells directly after isolation from the peripheral blood of ES, viremic patients, and uninfected donors. We utilized a green fluorescent protein (GFP)-expressing proviral construct pseudotyped with CCR5-tropic or CXCR4-tropic envelope to compare viral entry using a fluorescence resonance energy transfer-based, single-round virus-cell fusion assay. The frequency of productive infection was also compared by assessing GFP expression. CD4(+) T cells from ES were as susceptible as or more susceptible than cells from viremic patients and uninfected donors to HIV-1 entry and productive infection. The results of this physiological study strongly suggest that differences in HIV-1 entry and infection of CD4(+) T cells alone cannot explain the elite control of viral replication.     

Effects of fusaric acid treatment on the protocorm-like bodies of <Emphasis Type="Italic">Dendrobium</Emphasis> sonia-28

Dendrobium sonia-28 is a popular orchid hybrid due to its flowering recurrence and dense inflorescences. Unfortunately, it is being decimated by fungal diseases, especially those caused by Fusarium proliferatum. In this study, selection of F. proliferatum-tolerant protocorm-like bodies (PLBs) was carried out by assessing the effects of differing concentrations of fusaric acid (FA). PLBs were cultured on Murashige and Skoog (MS) medium supplemented with 0.05 to 0.2 millimolar (mM) concentrations of FA. Higher concentrations of FA increased mortality of PLBs and reduced their growth. The survival rate for 0.05 mM FA was 20 % but only 1 % at the highest dose of 0.2 mM. Additionally, two different size ranges of PLBs were investigated, and growth increased more at lower FA concentrations for larger PLBs, whilst the growth rate of smaller PLBs was inhibited at an FA concentration of 0.2 mM. Histological examination using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses disclosed severe cell wall and organelle damage, as well as stomatal closure in PLBs treated with the high FA concentrations. Reductions in plantlet growth were much greater at the highest concentrations of FA. Some randomly amplified polymorphic DNA (RAPD) markers clearly discriminated between selected and non-selected variants of Dendrobium sonia-28, showing different banding patterns for each FA concentration and specific bands for selected and control plants.     

Candidate Gene Identification with SNP Marker-Based Fine Mapping of Anthracnose Resistance Gene Co-4 in Common Bean

Anthracnose, caused by Colletotrichum lindemuthianum, is an important fungal disease of common bean (Phaseolus vulgaris). Alleles at the Co–4 locus confer resistance to a number of races of C. lindemuthianum. A population of 94 F_4:5 recombinant inbred lines of a cross between resistant black bean genotype B09197 and susceptible navy bean cultivar Nautica was used to identify markers associated with resistance in bean chromosome 8 (Pv08) where Co–4 is localized. Three SCAR markers with known linkage to Co–4 and a panel of single nucleotide markers were used for genotyping. A refined physical region on Pv08 with significant association with anthracnose resistance identified by markers was used in BLAST searches with the genomic sequence of common bean accession G19833. Thirty two unique annotated candidate genes were identified that spanned a physical region of 936.46 kb. A majority of the annotated genes identified had functional similarity to leucine rich repeats/receptor like kinase domains. Three annotated genes had similarity to 1, 3-β-glucanase domains. There were sequence similarities between some of the annotated genes found in the study and the genes associated with phosphoinositide-specific phosphilipases C associated with Co-x and the COK–4 loci found in previous studies. It is possible that the Co–4 locus is structured as a group of genes with functional domains dominated by protein tyrosine kinase along with leucine rich repeats/nucleotide binding site, phosphilipases C as well as β-glucanases.     

Characterization of Lung Fibroblasts More than Two Decades after Mustard Gas Exposure

Purpose

In patients with short-term exposure to the sulfur mustard gas, the delayed cellular effects on lungs have not been well understood yet. The lung pathology shows a dominant feature consistent with obliterative bronchiolitis, in which fibroblasts play a central role. This study aims to characterize alterations to lung fibroblasts, at the cellular level, in patients with delayed respiratory complications after short-term exposure to the sulfur mustard gas.

Methods

Fibroblasts were isolated from the transbronchial biopsies of patients with documented history of exposure to single high-dose sulfur mustard during 1985–7 and compared with the fibroblasts of control subjects.

Results

Compared with controls, patients’ fibroblasts were thinner and shorter, and showed a higher population doubling level, migration capacity and number of filopodia. Sulfur mustard decreased the in vitro viability of fibroblasts and increased their sensitivity to induction of apoptosis, but did not change the rate of spontaneous apoptosis. In addition, higher expression of alpha smooth muscle actin showed that the lung''s microenvironment in these patients is permissive for myofibroblastic differentiation.

Conclusions

These findings suggest that in patients under the study, the delayed pulmonary complications of sulfur mustard should be considered as a unique pathology, which might need a specific management by manipulation of cellular components.     

Investigation of TiO2 anatase (1 0 1), (1 0 0) and (1 1 0) facets as immobilizer for a potential anticancer RNA aptamer: a classical molecular dynamics simulation

One of the most outstanding properties of TiO₂ nanosheets is their lack of harmful effects on the public health and environment, which makes them an appropriate agent for medical applications such as drug delivery. Interaction of an RNA aptamer with (1 0 1), (1 0 0) and (1 1 0) surfaces of TiO₂ anatase were investigated using the molecular dynamics simulation. The structural parameters including root-mean-square deviation and fluctuation, and the distance between the center-of-mass of RNA aptamer and the considered surfaces were discussed in detail. Besides, the effect of water between adsorbed aptamer and surface was investigated and analyzed by the help of dipole moment orientation, hydrogen bonds and density profile of these water molecules. Analysis of the structural parameters and interaction energies shows that the (1 1 0) surface is energetically more favorable for the adsorption of considered RNA aptamer than the (1 0 0) and (1 0 1) surfaces. Consequently, our results suggest a great potential of (1 1 0) surface of TiO₂ as an efficient candidate for drug delivery applications.     

The Arabidopsis expansin gene (AtEXPA18) is capable to ameliorate drought stress tolerance in transgenic tobacco plants

Molecular Biology Reports - Expansins are cell wall proteins loosening plant cell in pH-dependent manner. This study aimed to investigate the role of AtEXPA18 in different morphological,...     

Vascular endothelial growth factor (VEGF) +405 C/G polymorphism is associated with essential hypertension in a population from Tehran of Iran

Vascular endothelial growth factor (VEGF) has long been recognized as a hypotensive mediator. Little is known regarding the contribution of polymorphisms in VEGF gene to essential hypertension (EH), however. We aimed to investigate the association between +405 VEGF C/G single nucleotide polymorphism (SNP) and occurrence of EH in a sample of patients with diabetes. A study population of 474 subjects with diabetes of which 45.6% (216) had EH was enrolled in this study. Interviews and physical examinations were performed in a clinical setting. Subjects were matched in baseline anthropometric and biochemical characteristics except for total cholesterol. Genotyping of +405 VEGF C/G (rs2010963) SNP was carried out using polymerase chain reaction–restriction fragment length polymorphism. The allelic distribution of the sample did not violate Hardy–Weinberg equilibrium. Subjects with EH had a higher frequency of G allele (P = 0.005). Additionally, those with EH had a significantly higher frequency of GG genotype (P = 0.015). In multivariate logistic regression models controlling for possible confounders, having GG against CC genotype was associated with an odds ratio of 2.51 (95% CI: 1.44–4.38; P = 0.001). Moreover, presence of each G allele was linked to a 1.58-fold increase in risk of having EH (95% CI: 1.200–2.086; P = 0.001). In conclusion, +405 VEGF C/G SNP is associated with EH in patients with diabetes, suggesting presence of G allele and GG or CG genotype confer susceptibility towards EH.     

Development and validation of a rapid HPLC method for simultaneous determination of tramadol, and its two main metabolites in human plasma

Tramadol, an analgesic agent, and its two main metabolites O-desmethyltramadol (M1) and N-desmethyltramadol (M2) were determined simultaneously in human plasma by a rapid and specific HPLC method. The sample preparation was a simple extraction with ethyl acetate. Chromatographic separation was achieved with a Chromolith Performance RP-18e 50 mm x 4.6 mm column, using a mixture of methanol:water (13:87, v/v) adjusted to pH 2.5 by phosphoric acid, in an isocratic mode at flow rate of 2 ml/min. Fluorescence detection (lambda(ex)=200 nm/lambda(em)=301 nm) was used. The calibration curves were linear (r(2)>0.997) in the concentration range of 2.5-500 ng/ml, 1.25-500 ng/ml and 5-500 ng/ml for tramadol, M1 and M2, respectively. The lower limit of quantification was 2.5 ng/ml for tramadol, 1.25 ng/ml for M1 and 5 ng/ml for M2. The within- and between-day precisions in the measurement of QC samples at four tested concentrations were in the range of 2.5-9.7%, 2.5-9.9% and 5.9-11.3% for tramadol, M1 and M2, respectively. The developed procedure was applied to assess the pharmacokinetics of tramadol and its two main metabolites following administration of 100mg single oral dose of tramadol to healthy volunteers.     

Selenium deficiency and hypothyroidism

Three female children presented with different clinical symptoms that could be related to impaired thyroid function. They underwent an accurate pediatric-endocrinologic diagnosis. Laboratory tests revealed no pathological findings, except latent hypothyroidism and selenium deficiency. Hypothyroidism was diagnosed by elevated basal TSH and by a pathological iv-TRH-stimulation test. After treating the children with sodium selenite orally for 4 wk, their metabolism had returned to normal and we saw a marked improvement of all clinical symptoms. For the first time, we have been able to describe hypothyroidism caused exclusively by selenium deficiency, the pathophysiology of which may be expressed as a malfunction of human 5′-deiodinases.