Evaluation of a Density-Based Rapid Diagnostic Test for Sickle Cell Disease in a Clinical Setting in Zambia

Although simple and low-cost interventions for sickle cell disease (SCD) exist in many developing countries, child mortality associated with SCD remains high, in part, because of the lack of access to diagnostic tests for SCD. A density-based test using aqueous multiphase systems (SCD-AMPS) is a candidate for a low-cost, point-of-care diagnostic for SCD. In this paper, the field evaluation of SCD-AMPS in a large (n = 505) case-control study in Zambia is described. Of the two variations of the SCD-AMPS used, the best system (SCD-AMPS-2) demonstrated a sensitivity of 86% (82–90%) and a specificity of 60% (53–67%). Subsequent analysis identified potential sources of false positives that include clotting, variation between batches of SCD-AMPS, and shipping conditions. Importantly, SCD-AMPS-2 was 84% (62–94%) sensitive in detecting SCD in children between 6 months and 1 year old. In addition to an evaluation of performance, an assessment of end-user operability was done with health workers in rural clinics in Zambia. These health workers rated the SCD-AMPS tests to be as simple to use as lateral flow tests for malaria and HIV.     

Production of volatile phenols by Lactobacillus plantarum in wine conditions

Some lactic acid bacteria produce volatile phenols in culture medium but this activity has not been extensively studied in wine conditions. Red and white wines were mixed with MRS medium at different ratios to study the influence of wine on the metabolism of p-coumaric and ferulic acids by Lactobacillus plantarum. In MRS broth supplemented with these precursors at 10 mg l^?1, only 4-ethylphenol was produced (1 mg l^?1) while, in the presence of wine, 4-vinylphenol was also obtained. Both volatile phenols are produced in nearly equal amounts (1 mg l^?1) or almost only 4-vinylphenol depending on the MRS:wine ratio. Thus, wine favours the accumulation of 4-vinylphenol. Ferulic acid was not or was weakly metabolized in the conditions studied.     

Assessing physiological tipping point of sea urchin larvae exposed to a broad range of pH

Our ability to project the impact of global change on marine ecosystem is limited by our poor understanding on how to predict species sensitivity. For example, the impact of ocean acidification is highly species‐specific, even in closely related taxa. The aim of this study was to test the hypothesis that the tolerance range of a given species to decreased pH corresponds to their natural range of exposure. Larvae of the green sea urchin Strongylocentrotus droebachiensis were cultured from fertilization to metamorphic competence (29 days) under a wide range of pH (from pH_T = 8.0/pCO₂ ≈ 480 μatm to pH_T = 6.5/pCO₂ ≈ 20 000 μatm) covering present (from pH_T 8.7 to 7.6), projected near‐future variability (from pH_T 8.3 to 7.2) and beyond. Decreasing pH impacted all tested parameters (mortality, symmetry, growth, morphometry and respiration). Development of normal, although showing morphological plasticity, swimming larvae was possible as low as pH_T ≥ 7.0. Within that range, decreasing pH increased mortality and asymmetry and decreased body length (BL) growth rate. Larvae raised at lowered pH and with similar BL had shorter arms and a wider body. Relative to a given BL, respiration rates and stomach volume both increased with decreasing pH suggesting changes in energy budget. At the lowest pHs (pH_T ≤ 6.5), all the tested parameters were strongly negatively affected and no larva survived past 13 days post fertilization. In conclusion, sea urchin larvae appeared to be highly plastic when exposed to decreased pH until a physiological tipping point at pH_T = 7.0. However, this plasticity was associated with direct (increased mortality) and indirect (decreased growth) consequences for fitness.     

Antifungal stress metabolites from Solanum aviculare

The steroidal alkaloids 5β-solasodan-3-one and solasodenone were isolated as antifungal stress metabolites from leaves of Solanum aviculare stressed by vacuum infiltration with water. The constitutive leaf alkaloids, solasodine and solamargine, also showed antifungal activity.     

Tissue- and temporal-specific regulation of 11beta-hydroxysteroid dehydrogenase type 1 by glucocorticoids in vivo.

11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1) catalyses the interconversion of active corticosterone and inert 11-dehydrocorticosterone. Short-term glucocorticoid excess upregulates 11β-HSD-1 in liver and hippocampus leading to suggestions that 11β-HSD-1 ameliorates the deleterious effects of glucocorticoid excess by its 11β-dehydrogenase activity. However the predominant activity of 11β-HSD-1 in vivo is 11β-reduction, thus generating active glucocorticoid. We have re-examined the time-course of glucocorticoid regulation of 11β-HSD-1 in the liver, hippocampus and kidney of adult male rats in vivo.

Sham operation markedly reduced 11β-HSD-1 mRNA expression in all tissues, and reduced 11β-HSD bioactivity in liver and hippocampus when compared to untouched controls. Adrenalectomy reduced 11β-HSD-1 expression in all tissues in the short-term (7 days), followed by subsequent recovery of enzyme activity by 21 days in liver and hippocampus. Dexamethasone replacement of adrenalectomised rats attenuated the initial decrease in hepatic 11β-HSD-1 activity, but by 21 days dexamethasone reduced activity compared to control levels.

Thus glucocorticoids regulate 11β-HSD-1 in a complex tissue- and temporal-specific manner. This pattern of regulation suggests glucocorticoids repress 11β-HSD-1 at least in the liver, a pattern of regulation more consistent with the evidence that 11β-HSD-1 is an 11β-reductase in vivo. Operational stress per se down-regulates 11β-HSD-1 which has implications for interpretation and design of in vivo studies of 11β-HSD-1.     

Increased phloem transport of S-methylmethionine positively affects sulfur and nitrogen metabolism and seed development in pea plants

Seeds of grain legumes are important energy and food sources for humans and animals. However, the yield and quality of legume seeds are limited by the amount of sulfur (S) partitioned to the seeds. The amino acid S-methylmethionine (SMM), a methionine derivative, has been proposed to be an important long-distance transport form of reduced S, and we analyzed whether SMM phloem loading and source-sink translocation are important for the metabolism and growth of pea (Pisum sativum) plants. Transgenic plants were produced in which the expression of a yeast SMM transporter, S-Methylmethionine Permease1 (MMP1, YLL061W), was targeted to the phloem and seeds. Phloem exudate analysis showed that concentrations of SMM are elevated in MMP1 plants, suggesting increased phloem loading. Furthermore, expression studies of genes involved in S transport and metabolism in source organs, as well as xylem sap analyses, support that S uptake and assimilation are positively affected in MMP1 roots. Concomitantly, nitrogen (N) assimilation in root and leaf and xylem amino acid profiles were changed, resulting in increased phloem loading of amino acids. When investigating the effects of increased S and N phloem transport on seed metabolism, we found that protein levels were improved in MMP1 seeds. In addition, changes in SMM phloem loading affected plant growth and seed number, leading to an overall increase in seed S, N, and protein content in MMP1 plants. Together, these results suggest that phloem loading and source-sink partitioning of SMM are important for plant S and N metabolism and transport as well as seed set.     

The synthesis and structure–activity relationship of 4-benzimidazolyl-piperidinylcarbonyl-piperidine analogs as histamine H3 antagonists

A structure–activity relationship study of the lead piperazinylcarbonylpiperidine compound 3 resulted in the identification of 4-benzimidazolyl-piperidinylcarbonyl-piperidine 6h as a histamine-3 (H₃) receptor antagonist. Additional optimization of 6h led to the identification of compounds 11i–k with K_i ? 0.5 nM and good in vivo activity.     

Association of FcγRIIa R131H polymorphism with idiopathic pulmonary fibrosis severity and progression

Background

Health status, dyspnea and psychological status are important clinical outcomes in chronic obstructive pulmonary disease (COPD). However, forced expiratory volume in one second (FEV₁) measured by spirometry, the standard measurement of airflow limitation, has only a weak relationship with these outcomes in COPD. Recently, in addition to spirometry, impulse oscillometry (IOS) measuring lung resistance (R) and reactance (X) is increasingly being used to assess pulmonary functional impairment.

Methods

We aimed to identify relationships between IOS measurements and patient-reported outcomes in 65 outpatients with stable COPD. We performed pulmonary function testing, IOS, high-resolution computed tomography (CT), and assessment of health status using the St. George's Respiratory Questionnaire (SGRQ), dyspnea using the Medical Research Council (MRC) scale and psychological status using the Hospital Anxiety and Depression Scale (HADS). We then investigated the relationships between these parameters. For the IOS measurements, we used lung resistance at 5 and 20 Hz (R5 and R20, respectively) and reactance at 5 Hz (X5). Because R5 and R20 are regarded as reflecting total and proximal airway resistance, respectively, the fall in resistance from R5 to R20 (R5-R20) was used as a surrogate for the resistance of peripheral airways. X5 was also considered to represent peripheral airway abnormalities.

Results

R5-R20 and X5 were significantly correlated with the SGRQ and the MRC. These correlation coefficients were greater than when using other objective measurements of pulmonary function, R20 on the IOS and CT instead of R5-R20 and X5. Multiple regression analyses showed that R5-R20 or X5 most significantly accounted for the SGRQ and MRC scores.

Conclusions

IOS measurements, especially indices of peripheral airway function, are significantly correlated with health status and dyspnea in patients with COPD. Therefore, in addition to its simplicity and non-invasiveness, IOS may be a useful clinical tool not only for detecting pulmonary functional impairment, but also to some extent at least estimating the patient's quality of daily life and well-being.     

Separation of 2-aminobenzamide labeled glycans using hydrophilic interaction chromatography columns packed with 1.7 μm sorbent

Separation by hydrophilic interaction chromatography (HILIC) with fluorescence detection utilizing a sub-2 μm glycan column for the separation of 2-aminobenzamide (2-AB) labeled N-linked glycans is described. The HILIC column packed with a 1.7 μm amide sorbent improves the peak capacity compared to a 3.0 μm HILIC column by a similar degree as observed in reversed-phase ultra-performance liquid chromatography (RP-UPLC). The results indicated that the optimal peak capacity was achieved at flow rate 0.2–0.5 mL/min. HILIC method transfer guidelines were shown to further enhance the resolution of glycans by changing initial gradient conditions, flow rate, column temperature, and different column lengths. Additionally, excellent resolution can be achieved in the separation of 2-AB labeled glycans released from fetuin, RNase B, and human IgG with a rapid analysis time.