Towards Validation of a New Computerised Test of Goal Neglect: Preliminary Evidence from Clinical and Neuroimaging Pilot Studies

Objective

Goal neglect is a significant problem following brain injury, and is a target for rehabilitation. It is not yet known how neural activation might change to reflect rehabilitation gains. We developed a computerised multiple elements test (CMET), suitable for use in neuroimaging paradigms.

Design

Pilot correlational study and event-related fMRI study.

Methods

In Study 1, 18 adults with acquired brain injury were assessed using the CMET, other tests of goal neglect (Hotel Test; Modified Six Elements Test) and tests of reasoning. In Study 2, 12 healthy adults underwent fMRI, during which the CMET was administered under two conditions: self-generated switching and experimenter-prompted switching.

Results

Among the clinical sample, CMET performance was positively correlated with both the Hotel Test (r = 0.675, p = 0.003) and the Modified Six Elements Test (r = 0.568, p = 0.014), but not with other clinical or demographic measures. In the healthy sample, fMRI demonstrated significant activation in rostro-lateral prefrontal cortex in the self-generated condition compared with the prompted condition (peak 40, 44, 4; Z_E = 4.25, p_(FWEcorr) = 0.026).

Conclusions

These pilot studies provide preliminary evidence towards the validation of the CMET as a measure of goal neglect. Future studies will aim to further establish its psychometric properties, and determine optimum pre- and post-rehabilitation fMRI paradigms.     

Nucleotide sequences of four pathogen-induced alfalfa peroxidase-encoding cDNAs

We constructed an alfalfa cDNA library from mRNA extracted from leaves after infection with Pseudomonas syringae (incompatible interaction). Screening with oligodeoxyribonucleotides designed from regions conserved in all known peroxidases allowed the isolation of four cDNAs (MsprxlA, 1B, 1C and 2). Sequence analysis revealed the presence of open reading frames of 351, 355, 358 and 323 amino acids, respectively, with the characteristic consensus sequences of plant peroxidases. Sequence comparison showed that the Msprx2 product is significantly different from the others and, particularly, lacks a C-terminal propeptide which might be required for vacuolar targeting.     

Impaired beta-cell compensation to dexamethasone-induced hyperglycemia in women with polycystic ovary syndrome

Deterioration in glucose tolerance occurs rapidly in women with polycystic ovary syndrone (PCOS), suggesting that pancreatic beta-cell dysfunction may supervene early. To determine whether the compensatory insulin secretory response to an increase in insulin resistance induced by the glucocorticoid dexamethasone differs in women with PCOS and control subjects, we studied 10 PCOS and 6 control subjects with normal glucose tolerance. An oral glucose tolerance test (OGTT) and a graded glucose infusion protocol were performed at baseline and after subjects took 2.0 mg of dexamethasone orally. Basal (Phi(b)), static (Phi(s)), dynamic (Phi(d)), and global (Phi) indexes of beta-cell sensitivity to glucose were derived. Insulin sensitivity (S(i)) was calculated using the minimal model; a disposition index (DI) was calculated as the product of S(i) and Phi. PCOS and control subjects had nearly identical fasting and 2-h glucose levels at baseline. Phi(b) was higher, although not significantly so, in the PCOS subjects. The Phi(d), Phi(s), and Phi indexes were 28, 19, and 20% higher, respectively, in PCOS subjects. The DI was significantly lower in PCOS (30.01 +/- 5.33 vs. 59.24 +/- 7.59) at baseline. After dexamethasone, control subjects averaged a 9% increase (to 131 +/- 12 mg/dl) in 2-h glucose levels; women with PCOS had a significantly greater 26% increase to 155 +/- 6 mg/dl. The C-peptide-to-glucose ratios on OGTT increased by 44% in control subjects and by only 15% in PCOS subjects. The accelerated deterioration in glucose tolerance in PCOS may result, in part, from a relative attenuation in the response of the beta-cell to the demand placed on it by factors exacerbating insulin resistance.     

Mammalian osmolytes and S-nitrosoglutathione promote Delta F508 cystic fibrosis transmembrane conductance regulator (CFTR) protein maturation and function

In cystic fibrosis, the absence of functional CFTR results in thick mucous secretions in the lung and intestines, as well as pancreatic deficiency. Although expressed at high levels in the kidney, mutations in CFTR result in little or no apparent kidney dysfunction. In an effort to understand this phenomenon, we analyzed Delta F508 CFTR maturation and function in kidney cells under conditions that are common to the kidney, namely osmotic stress. Kidney cells were grown in culture and adapted to 250 mM NaCl and 250 mM urea. High performance liquid chromatography analysis of lysates from kidney cells adapted to these conditions identified an increase in the cellular osmolytes glycerophosphorylcholine, myo-inositol, sorbitol, and taurine. In contrast to isoosmotic conditions, hyperosmotic stress led to the proper folding and processing of Delta F508 CFTR. Furthermore, three of the cellular osmolytes, when added individually to cells, proved effective in promoting the proper folding and processing of the Delta F508 CFTR protein in both epithelial and fibroblast cells. Whole-cell patch clamping of osmolyte-treated cells showed that Delta F508 CFTR had trafficked to the plasma membrane and was activated by forskolin. Encouraged by these findings, we looked at other features common to the kidney that may impact Delta F508 maturation and function. Interestingly, a small molecule, S-nitrosoglutathione, which is a substrate for gamma glutamyltranspeptidase, an abundant enzyme in the kidney, likewise promoted Delta F508 CFTR maturation and function. S-Nitrosoglutathione-corrected Delta F508 CFTR exhibited a shorter half-life as compared with wild type CFTR. These results demonstrate the feasibility of a small molecule approach as a therapeutic treatment in promoting Delta F508 CFTR maturation and function and suggest that an additional treatment may be required to stabilize Delta F508 CFTR protein once present at the plasma membrane. Finally, our observations may help to explain why Delta F508 homozygous patients do not present with kidney dysfunction.     

Effect of paracetamol (acetaminophen) and ibuprofen on body temperature in acute ischemic stroke PISA, a phase II double-blind, randomized, placebo-controlled trial [ISRCTN98608690]

Background

Body temperature is a strong predictor of outcome in acute stroke. In a previous randomized trial we observed that treatment with high-dose acetaminophen (paracetamol) led to a reduction of body temperature in patients with acute ischemic stroke, even when they had no fever. The purpose of the present trial was to study whether this effect of acetaminophen could be reproduced, and whether ibuprofen would have a similar, or even stronger effect.

Methods

Seventy-five patients with acute ischemic stroke confined to the anterior circulation were randomized to treatment with either 1000 mg acetaminophen, 400 mg ibuprofen, or placebo, given 6 times daily during 5 days. Treatment was started within 24 hours from the onset of symptoms. Body temperatures were measured at 2-hour intervals during the first 24 hours, and at 6-hour intervals thereafter.

Results

No difference in body temperature at 24 hours was observed between the three treatment groups. However, treatment with high-dose acetaminophen resulted in a 0.3°C larger reduction in body temperature from baseline than placebo treatment (95% CI: 0.0 to 0.6 °C). Acetaminophen had no significant effect on body temperature during the subsequent four days compared to placebo, and ibuprofen had no statistically significant effect on body temperature during the entire study period.

Conclusions

Treatment with a daily dose of 6000 mg acetaminophen results in a small, but potentially worthwhile decrease in body temperature after acute ischemic stroke, even in normothermic and subfebrile patients. Further large randomized clinical trials are needed to study whether early reduction of body temperature leads to improved outcome.     

Combining the Sterile Insect Technique with Wolbachia-Based Approaches: II- A Safer Approach to Aedes albopictus Population Suppression Programmes,Designed to Minimize the Consequences of Inadvertent Female Release

Due to the absence of a perfect method for mosquito sex separation, the combination of the sterile insect technique and the incompatible insect technique is now being considered as a potentially effective method to control Aedes albopictus. In this present study first we examine the minimum pupal irradiation dose required to induce complete sterility in Wolbachia triple-infected (HC), double-infected (GUA) and uninfected (GT) female Ae. albopictus. The HC line is a candidate for Ae. albopictus population suppression programmes, but due to the risk of population replacement which characterizes this triple infected line, the individuals to be released need to be additionally irradiated. After determining the minimum irradiation dose required for complete female sterility, we test whether sterilization is sufficient to prevent invasion of the triple infection from the HC females into double-infected (GUA) populations. Our results indicate that irradiated Ae. albopictus HC, GUA and GT strain females have decreased fecundity and egg hatch rate when irradiated, inversely proportional to the dose, and the complete sterilization of females can be acquired by pupal irradiation with doses above 28 Gy. PCR-based analysis of F₁ and F₂ progeny indicate that the irradiated HC females, cannot spread the new Wolbachia wPip strain into a small cage GUA population, released at a 1:5 ratio. Considering the above results, we conclude that irradiation can be used to reduce the risk of population replacement caused by an unintentional release of Wolbachia triple-infected Ae. albopictus HC strain females during male release for population suppression.     

Relation between Red Cell Distribution Width and Fibroblast Growth Factor 23 Cleaving in Patients with Chronic Kidney Disease and Heart Failure

Objective

In chronic kidney disease (CKD), both anemia and deregulated phosphate metabolism are common and predictive of adverse outcome. Previous studies suggest that iron status influences phosphate metabolism by modulating proteolytic cleavage of FGF23 into C-terminal fragments. Red cell distribution width (RDW) was recently identified as a strong prognostic determinant for cardiovascular morbidity and mortality, independently of iron status. We assessed whether RDW is associated with FGF23 cleaving in CKD patients with heart failure.

Materials and Methods

The associations between RDW and either intact FGF23 (iFGF23), C-terminal FGF23 (cFGF23, reflecting iFGF23 and C-terminal fragments together) and the iFGF23/cFGF23 ratio were analyzed in 52 patients with CKD (eGFR 34,9 ± 13.9 ml/min/1.73m²) and chronic heart failure (CHF). Associations between RDW and FGF23 forms were studied by linear regression analysis adjusted for parameters of renal function, iron metabolism, phosphate metabolism and inflammation.

Results

Median cFGF23 levels were 197.5 [110–408.5] RU/ml, median iFGF23 levels were 107.3 [65.1–162.2] pg/ml and median FGF23 ratio was 0.80 [0.37–0.86]. Mean RDW was 14.1 ± 1.2%. cFGF23 and RDW were associated (β = 1.63x10^-3, P <0.001), whereas iFGF23 and RDW were not (β = -1.38x10^-3, P = 0.336). The iFGF23/cFGF23 ratio was inversely associated with RDW. The difference between cFGF23 and iFGF23 (cFGF23- iFGF23) was positively associated with RDW (β = 1.74x10^-3, P< 0.001). The association between cFGF23 and RDW persisted upon multivariable linear regression analysis, adjusted for parameters of renal function, phosphate metabolism, iron metabolism and inflammation (β = 0.97x10^-3, P = 0.047).

Conclusion

RDW is associated with cFGF23 but not with iFGF23 levels in patients with CKD and CHF. This suggests a connection between RDW and FGF23 catabolism, independent of iron status and inflammation. Future studies are needed to unravel underlying mechanisms and whether these pertain to the link between RDW and outcome.