Numerical Simulations and Long-Column Tests of LNAPL Displacement and Trapping by a Fluctuating Water Table

Long-column laboratory tests were performed to validate improvements to the MOFAT program for simulating LNAPL displacement and entrapment in response to a fluctuating water table. The long-column tests consisted of a fluctuating water table and its subsequent displacement and entrapment of an LNAPL. The modifications of MOFAT include a linear LNAPL trapping estimate and a new scaling technique for the inhibition portion of the fluctuation (water table rise). Improved prediction of the LNAPL trapping was obtained by assuming the amount of LNAPL that is trapped by a rising water table is proportional to the antecedent water content of the porous medium. The pressure-saturation relationship for the air-water drainage system was scaled to estimate the LNAPL-water and air-LNAPL drainage relationships. Scaled inhibition pressure-saturation relationships are improved by incorporating a correction for contact angle hysteresis and surface roughness. The incorporation of these changes into MOFAT led to noticable improvements in the numerical simulation of the experimental data.     

An insertion vector for the analysis of gene expression during herpes simplex virus infection

A herpes simplex virus type 1 (HSV-1) insertion vector, pGal8, was designed for analysis of herpesvirus promoters during virus infection. This vector contains a multiple cloning site (MCS) positioned at the 5' end of the lacZ gene for the insertion of promoter sequences. The MCS and lacZ are flanked by sequences from the HSV-1 thymidine kinase encoding gene (tk) to direct homologous recombination into the tk locus of the viral genome. The utility of this vector is demonstrated by construction and comparison of recombinant viruses that express lacZ from the promoters of the genes encoding glycoprotein C, glycoprotein H and glycoprotein E.     

Transdominant inhibition of wild-type human immunodeficiency virus type 2 replication by an envelope deletion mutant.

The envelope glycoprotein of human immunodeficiency virus type 2 (HIV-2) is primarily responsible for virus attachment and entry into the target cell population. We constructed an HIV-2 mutant virus containing an in-frame deletion within the putative CD4-binding sequences of the envelope glycoprotein and confirmed that the mutant envelope is unable to bind CD4 and that the mutant virus is noninfectious. To investigate whether this mutant could dominantly interfere with wild-type replication, we coexpressed proviral DNAs of both wild-type and mutant viruses in cells and assayed the production of infectious HIV-2 virions. Interference with virus replication was indeed observed with mutant DNA, and a maximal effect was achieved with 10-fold excess mutant DNA over wild-type DNA in the cotransfection experiments. The transdominant effect on virus replication does not appear to be at the level of wild-type envelope expression or gp120-CD4 interaction. Rather, the interference may be at the level of mixed-oligomer formation during progeny virus assembly and may occur by either destabilizing the multimeric structure of gp120 or forming a defective mixed multimeric gp120 which is unable to complete the receptor binding and/or postbinding events needed for infection.     

Role of the fusogenic peptide sequence in syncytium induction and infectivity of human immunodeficiency virus type 2.

Syncytium induction is a characteristic feature of infection by human immunodeficiency virus (HIV) in vitro. The hydrophobic amino terminus of the transmembrane glycoprotein of HIV type 1 is an essential determinant of virus entry into the target cell population and the formation of syncytia in cell culture. To define the role of the HIV type 2 fusion peptide during infection and syncytium formation, we introduced 8 amino acid substitutions into the hydrophobic amino terminus of gp41, changing either the hydrophobicity, the charge, or the polarity of the amino acid. Viruses containing the envelope mutations were analyzed for their syncytium-inducing capacities, levels of infectivity, and envelope processing and expression. Mutations that increased the hydrophobic nature of the fusion peptide increased syncytium formation, whereas mutations which increased the charge and the polarity and/or decreased the hydrophobicity of the fusion domain severely reduced the capacity of the virus to induce syncytia. However, viruses severely compromised for syncytium formation exhibit only slightly lower levels of infectivity.     

Lung tissue extracellular matrix-derived hydrogels protect against radiation-induced lung injury by suppressing epithelial–mesenchymal transition

This study aimed to examine whether lung tissue extracellular matrix (ECM) hydrogels have protective effects on radiation-induced lung injury (RILI). The cytocompatibility and histocompatibility were tested for the obtained ECM-derived hydrogel. Sprague–Dawley rats were randomly divided into three groups (n = 18): control group (control); rats receiving irradiation and intratracheal injection of normal saline (IR + NS); and rats receiving irradiation and intratracheal injection of lung ECM-derived hydrogel (IR + ECM). The wet/dry weight ratio was used to evaluate the congestion and edema of the lungs. Histopathological analysis of lung tissues was performed using hemotoxylin and eosin staining and Masson's trichrome staining. Immunohistochemical staining and western blot analyses were carried out to determine the expression of epithelial–mesenchymal transition (EMT)-related proteins in lung tissues (E-cadherin, α-smooth muscle actin [α-SMA], and vimentin). In addition, tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1) and interleukin-6 (IL-6), hydroxyproline, malondialdehyde (MDA), and superoxide dismutase (SOD) levels were also evaluated. The ECM-derived hydrogels had good cytocompatibility and histocompatibility. ECM-derived hydrogel treatment improved lung histopathology injury and pulmonary edema. Higher expression of E-cadherin and lower expression of vimentin and α-SMA were found in the IR + ECM group compared with those in the IR + NS group. Hydroxyproline levels were reduced by ECM-derived hydrogel treatment compared with those in the IR + NS group. Obvious increases of TNF-α, IL-6, and TGF-β1 were identified following irradiation. Marked reductions in MDA content and increases in SOD were induced by ECM-derived hydrogel treatment in rats after radiation. ECM-derived hydrogels were shown to protect against RILI, potentially by reducing EMT, inflammation, and oxidative damage.     

In vitro selection and characterization of influenza A (A/N9) virus variants resistant to a novel neuraminidase inhibitor, A-315675

With the recent introduction of neuraminidase (NA) inhibitors into clinical practice for the treatment of influenza virus infections, considerable attention has been focused on the potential for resistance development and cross-resistance between different agents from this class. A-315675 is a novel influenza virus NA inhibitor that has potent enzyme activity and is highly active in cell culture against a variety of strains of influenza A and B viruses. To further assess the therapeutic potential of this compound, in vitro resistance studies have been conducted and a comparative assessment has been made relative to oseltamivir carboxylate. The development of viral resistance to A-315675 was studied by in vitro serial passage of influenza A/N9 virus strains grown in MDCK cells in the presence of increasing concentrations of A-315675. Parallel passaging experiments were conducted with oseltamivir carboxylate, the active form of a currently marketed oral agent for the treatment of influenza virus infections. Passage experiments with A-315675 identified a variant at passage 8 that was 60-fold less susceptible to the compound. Sequencing of the viral population identified an E119D mutation in the NA gene, but no mutations were observed in the hemagglutinin (HA) gene. However, by passage 10 (2.56 microM A-315675), two mutations (R233K, S339P) in the HA gene appeared in addition to the E119D mutation in the NA gene, resulting in a 310-fold-lower susceptibility to A-315675. Further passaging at higher drug concentrations had no effect on the generation of further NA or HA mutations (20.5 microM A-315675). This P15 virus displayed 355-fold-lower susceptibility to A-315675 and >175-fold-lower susceptibility to zanamivir than did wild-type virus, but it retained a high degree of susceptibility to oseltamivir carboxylate. By comparison, virus variants recovered from passaging against oseltamivir carboxylate (passage 14) harbored an E119V mutation and displayed a 6,000-fold-lower susceptibility to oseltamivir carboxylate and a 175-fold-lower susceptibility to zanamivir than did wild-type virus. Interestingly, this mutant still retained susceptibility to A-315675 (42-fold loss). This suggests that cross-resistance between A-315675- and oseltamivir carboxylate-selected variants in vitro is minimal.     

Mapping of citrullinated fibrinogen B-cell epitopes in rheumatoid arthritis by imaging surface plasmon resonance

Introduction  

Rheumatoid arthritis (RA) frequently involves the loss of tolerance to citrullinated antigens, which may play a role in pathogenicity. Citrullinated fibrinogen is commonly found in inflamed synovial tissue and is a frequent target of autoantibodies in RA patients. To obtain insight into the B-cell response to citrullinated fibrinogen in RA, its autoepitopes were systematically mapped using a new methodology.     

Association of 25-Hydroxyvitamin D status and genetic variation in the vitamin D metabolic pathway with FEV1 in the Framingham Heart Study

Background

Vitamin D is associated with lung function in cross-sectional studies, and vitamin D inadequacy is hypothesized to play a role in the pathogenesis of chronic obstructive pulmonary disease. Further data are needed to clarify the relation between vitamin D status, genetic variation in vitamin D metabolic genes, and cross-sectional and longitudinal changes in lung function in healthy adults.

Methods

We estimated the association between serum 25-hydroxyvitamin D [25(OH)D] and cross-sectional forced expiratory volume in the first second (FEV₁) in Framingham Heart Study (FHS) Offspring and Third Generation participants and the association between serum 25(OH)D and longitudinal change in FEV₁ in Third Generation participants using linear mixed-effects models. Using a gene-based approach, we investigated the association between 241 SNPs in 6 select vitamin D metabolic genes in relation to longitudinal change in FEV₁ in Offspring participants and pursued replication of these findings in a meta-analyzed set of 4 independent cohorts.

Results

We found a positive cross-sectional association between 25(OH)D and FEV₁ in FHS Offspring and Third Generation participants (P = 0.004). There was little or no association between 25(OH)D and longitudinal change in FEV₁ in Third Generation participants (P = 0.97). In Offspring participants, the CYP2R1 gene, hypothesized to influence usual serum 25(OH)D status, was associated with longitudinal change in FEV₁ (gene-based P < 0.05). The most significantly associated SNP from CYP2R1 had a consistent direction of association with FEV₁ in the meta-analyzed set of replication cohorts, but the association did not reach statistical significance thresholds (P = 0.09).

Conclusions

Serum 25(OH)D status was associated with cross-sectional FEV₁, but not longitudinal change in FEV₁. The inconsistent associations may be driven by differences in the groups studied. CYP2R1 demonstrated a gene-based association with longitudinal change in FEV₁ and is a promising candidate gene for further studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0238-y) contains supplementary material, which is available to authorized users.     

Familial longevity is marked by lower diurnal salivary cortisol levels: the Leiden Longevity Study

Background

Reported findings are inconsistent whether hypothalamic-pituitary-adrenal (HPA) signaling becomes hyperactive with increasing age, resulting in increasing levels of cortisol. Our previous research strongly suggests that offspring from long-lived families are biologically younger. In this study we assessed whether these offspring have a lower HPA axis activity, as measured by lower levels of cortisol and higher cortisol feedback sensitivity.

Methods

Salivary cortisol levels were measured at four time points within the first hour upon awakening and at two time points in the evening in a cohort comprising 149 offspring and 154 partners from the Leiden Longevity Study. A dexamethasone suppression test was performed as a measure of cortisol feedback sensitivity. Age, gender and body mass index, smoking and disease history (type 2 diabetes and hypertension) were considered as possible confounding factors.

Results

Salivary cortisol secretion was lower in offspring compared to partners in the morning (Area Under the Curve = 15.6 versus 17.1 nmol/L, respectively; p = 0.048) and in the evening (Area Under the Curve = 3.32 versus 3.82 nmol/L, respectively; p = 0.024). Salivary cortisol levels were not different after dexamethasone (0.5 mg) suppression between offspring and partners (4.82 versus 5.26 nmol/L, respectively; p = 0.28).

Conclusion

Offspring of nonagenarian siblings are marked by a lower HPA axis activity (reflected by lower diurnal salivary cortisol levels), but not by a difference in cortisol feedback sensitivity. Further in-depth studies aimed at characterizing the HPA axis in offspring and partners are needed.     

Clinical features and predictors for disease natural progression in adults with Pompe disease: a nationwide prospective observational study

Background

Due partly to physicians’ unawareness, many adults with Pompe disease are diagnosed with great delay. Besides, it is not well known which factors influence the rate of disease progression, and thus disease outcome. We delineated the specific clinical features of Pompe disease in adults, and mapped out the distribution and severity of muscle weakness, and the sequence of involvement of the individual muscle groups. Furthermore, we defined the natural disease course and identified prognostic factors for disease progression.

Methods

We conducted a single-center, prospective, observational study. Muscle strength (manual muscle testing, and hand-held dynamometry), muscle function (quick motor function test), and pulmonary function (forced vital capacity in sitting and supine positions) were assessed every 3–6 months and analyzed using repeated-measures ANOVA.

Results

Between October 2004 and August 2009, 94 patients aged between 25 and 75 years were included in the study. Although skeletal muscle weakness was typically distributed in a limb-girdle pattern, many patients had unfamiliar features such as ptosis (23%), bulbar weakness (28%), and scapular winging (33%). During follow-up (average 1.6 years, range 0.5-4.2 years), skeletal muscle strength deteriorated significantly (mean declines of ?1.3% point/year for manual muscle testing and of ?2.6% points/year for hand-held dynamometry; both p<0.001). Longer disease duration (>15 years) and pulmonary involvement (forced vital capacity in sitting position <80%) at study entry predicted faster decline. On average, forced vital capacity in supine position deteriorated by 1.3% points per year (p=0.02). Decline in pulmonary function was consistent across subgroups. Ten percent of patients declined unexpectedly fast.

Conclusions

Recognizing patterns of common and less familiar characteristics in adults with Pompe disease facilitates timely diagnosis. Longer disease duration and reduced pulmonary function stand out as predictors of rapid disease progression, and aid in deciding whether to initiate enzyme replacement therapy, or when.