Search

Knowledge on the role of synovial signal intensity (SI) grading on static contrast-enhanced (CE) MRI of the knee for assessment of disease activity in juvenile idiopathic arthritis (JIA) is lacking. To assess the value of synovial SI on static CE-MRI of the knee for evaluation of disease activity in children with JIA. Children with clinically inactive and clinically active JIA who underwent static CE-MRI of the knee were included. Synovial SI was evaluated on post-contrast T1-weighted fat-saturated images using a 0.02 cm2 region of interest drawn in the area of the synovium that contained visually the highest SI. To control for potential time-dependent post-contrast enhancement variability, a ratio between the SI of the synovium to the musculus gastrocnemius was calculated. We included 427 JIA patients (clinically inactive JIA: 150 [35,1%]; clinically active JIA: 277 [64.9%]), 65.3% female, with a mean age of 13.3 ± 3.2 years. Mean SI synovium-to-muscle ratio was 2.1 ± 0.7 in patients with clinically inactive JIA versus 2.2 ± 0.8 in patients with clinically active JIA. Subgroup analysis showed no significant difference in SI synovium-to-muscle ratio between JIA patients with clinically inactive disease and JIA patients with clinically active disease (p -value 0.22). Evaluation of the brightness of the synovium on static CE-MRI of the knee for assessment of JIA disease activity should be avoided, as this might lead to incorrect clinical conclusions. • Knowledge on the role of synovial signal intensity (SI) grading on static CE-MRI of the knee for evaluation of disease activity in juvenile idiopathic arthritis (JIA) is lacking. • Synovial SI on static CE-MRI of the knee did not differ between patients with inactive JIA and active JIA. • More brightness of the synovium on static CE-MRI of the knee does not automatically implicate higher JIA disease activity. [ABSTRACT FROM AUTHOR]

Background: Target controlled infusion (TCI) systems use population-based pharmacokinetic (PK) models that do not take into account inter-individual residual variation. This study compares the bias and inaccuracy of a population-based vs a personalized TCI propofol titration using Bayesian adaptation. Haemodynamic and hypnotic stability, and the prediction probability of alternative PK models, was studied.Methods: A double-blinded, prospective randomized controlled trial of 120 subjects undergoing cardiac surgery was conducted. Blood samples were obtained at 10, 35, 50, 65, 75 and 120 min and analysed using a point-of-care propofol blood analyser. Bayesian adaptation of the PK model was applied at 60 min in the intervention group. Median (Absolute) Performance Error (Md(A)PE) was used to evaluate the difference between bias and inaccuracy of the models. Haemodynamic (mean arterial pressure [MAP], heart rate) and hypnotic (bispectral index [BIS]) stability was studied. The predictive performance of four alternative propofol PK models was studied.Results: MdPE and MdAPE did not differ between groups during the pre-adjustment period (control group: 6.3% and 16%; intervention group: 5.4% and 18%). MdPE differed in the post-adjustment period (12% vs. -0.3%), but MdAPE did not (18% vs. 15%). No difference in heart rate, MAP or BIS was found. Compared with the other models, the Eleveld propofol PK model (patients) showed the best prediction performance.Conclusions: When an accurate population-based PK model was used for propofol TCI, Bayesian adaption of the model improved bias but not precision.Clinical Trial Registration: Dutch Trial Registry NTR4518. [ABSTRACT FROM AUTHOR]

This review describes the basics of pharmacokinetic and pharmacodynamic drug interactions and methodological points of particular interest when designing drug interaction studies. It also provides an overview of the available literature concerning interactions, with emphasis on graphic representation of interactions using isoboles and response surface models. It gives examples on how to transform this knowledge into clinically and educationally applicable (bedside) tools. [ABSTRACT FROM AUTHOR]

Abstract: A concern regarding planting of Bt crops is that their widespread cultivation could lead to evolution of insect resistance to Bt toxins. In South Africa, the noctuid maize stem borer (Busseola fusca [Fuller]), is resistant to Bt maize (Zea mays L.; MON810) which produces Cry1Ab protein. The presence of fitness costs in resistant populations could be a valuable component of resistance management since the non-Bt maize refuge may select against resistance. The aim of the study was to determine if there are fitness costs associated with Bt resistance of B. fusca. Life history parameters were compared between individuals of a Bt maize resistant B. fusca population when feeding on Bt or non-Bt maize. Similar comparisons were done using a control population. Field collected larvae as well as their F 1-generation were used in the study. The following parameters were compared: pupal mass, moth longevity, fecundity, fertility, larval mass and survival, and sex ratio. Except for LT50-values, no fitness costs were associated with the resistance trait in the highly resistant B. fusca population. The absence of fitness costs and presence of resistant populations may promote the use of a multi-gene strategy which would be expected to impact negatively on fitness. [Copyright &y& Elsevier]

Abstract: Ten fungal isolates belonging to the genera Beauveria (3), Hypocrea (1), Gibberella (1), Metarhizium (2), Trichoderma (1) and Fusarium (2) were evaluated in the laboratory to determine whether they could become endophytic in two pea leafminer (Liriomyza huidobrensis) host plants (Vicia faba and Phaseolus vulgaris), and to assess their possible negative effects on leafminers. Beauveria (ICIPE279), Hypocrea, Gibberella, Fusarium and Trichoderma isolates colonized roots, stems and leaves of both host plant species. Beauveria isolates G1LU3 and S4SU1 colonized roots, stems, and leaves of P. vulgaris but only the root and stem of V. faba. Isolates of Metarhizium failed to colonize the two host plants. The effects of endophytically colonized fungal pathogens on mortality, oviposition, emergence and longevity of L. huidobrensis were investigated after endophytic colonization of V. faba plants. All the fungal isolates that succeeded in colonizing the host plant were pathogenic to L. huidobrensis, causing 100 % mortality within 13.2 ± 0.7–15.0 ± 0.6 d. However, Hypocrea outperformed the other isolates (p < 0.0 001) in reducing longevity of the progeny (11.2 ± 1.0 vs. 17.8 ± 1.4 d in the control), the number of pupae (80.0 ± 6.7 vs. 387.0 ± 21.7 pupae in the control), and adult longevity (3.8 ± 1.0 vs. 9.9 ± 1.8 d in the control). Adult emergence was significantly reduced (p < 0.0 001) in Hypocrea (21.4 %) and Beauveria (38.0 %) treatments compared to the control (82.9 %). [Copyright &y& Elsevier]

Abstract: Sand waves are more or less parallel ridges, making bed patterns in shallow seas. Due to their dimensions and migration rate, they can have a considerable effect on offshore human activities. In relation to such activities especially the variation in the sand wave characteristics (wave length, height and migration) are of importance. Due to the large spatial scale of sand waves and the different time scales involved for the tidal flow (hours) and the bed pattern changes (years to decades), modelling the sand wave behaviour from its initial stage up to its final equilibrium shape is a challenge, let alone to include the spatial variation within a sand wave field. In this paper a numerical solver is presented that describes sand waves from their initial state up to their final equilibrium. It is a 2DV idealized model, based on non-linear stability analysis. Both the model equations and the numerical setup are described and the model is validated against linear stability analysis. To investigate variations in a field of sand waves and the interaction between individual waves, simulations on large domains are presented and show that this solver is able to describe the development of a realistic sand wave field, with variations, from an initially flat sand bed with small random disturbances. The solver shows to be a promising tool, it is computational fast due to the efficient numerical algorithms and is easy to extend with other physical processes. Results show good agreement with analytical results in the linear regime and with field data. [Copyright &y& Elsevier]

Abstract: Bt maize has been grown at the Vaalharts irrigation scheme in South Africa since its first release during 1998. Interest in Bt maize refuge compliance, pest incidence and production practices at Vaalharts were recently stimulated by the first report of field resistance of Busseola fusca (Lepidoptera: Noctuidae) to Bt maize. Objectives of this study were to evaluate farmer''s perceptions of the regulatory aspects guiding the planting of Bt maize and refugia and how the field situation developed between 1998 and 2008. A survey, using a self-administered questionnaire, was conducted amongst 80 farmers at the irrigation scheme. The questionnaire addressed signing of contracts upon purchasing genetically modified (GM) seed, refuge compliance, refuge design and general farming practices. Farmers were also questioned on the perceived benefits and disadvantages of Bt maize and their perceptions of the pest status of B. fusca. The two greatest advantages associated with Bt maize were indicated to be convenient management (88%) and increased productivity (61.3%) while 42.5% indicated that they perceived Bt-technology to be environmental friendly. Initial levels of refuge compliance were low, and even though farmers were obligated to plant a refuge area for each Bt maize field, only 7.7% of farmers planted refuges during 1998. This number increased to 100% during 2008. Eight percent of farmers, however, indicated that they did not plant a refuge field for each Bt maize field, which was justified on the basis of small farm sizes (25ha). Nearly all farmers (99.8%) allow no spatial separation between the Bt maize field and adjacent refuge area. Farmers preferred to plant the refuge option where 5% of the field area is planted to conventional maize, which is not sprayed with insecticide instead of the 20% refuge area on which insecticide application against the target pest is allowed. In South Africa stewardship programs instituted during the 2008/2009 growing season, involve grower education programs as well as the compulsory signing of contracts between companies and farmers that contractually bind them to comply with refuge requirements accompanied by on-farm inspections. It appears that stem borer resistance to Bt maize in the Vaalharts area resulted from a combination of a late general planting date with consequent increased levels of infestation and variance in time of planting providing a continuous supply of moths. [Copyright &y& Elsevier]

Proteasome-associated autoinflammatory syndromes (PRAASs) form a family of recently described rare autosomal recessive disorders of disturbed proteasome assembly and proteolytic activity caused by mutations in genes coding for proteasome subunits. The treatment options for these proteasome disorders consist of lifelong immunosuppressive drugs or Janus kinase inhibitors, which may have partial efficacy and noticeable side effects. Because proteasomes are ubiquitously expressed, it is unknown whether hematopoietic stem cell transplantation (HSCT) may be a sufficient treatment option. Our aim was to report the case of a young boy with a treatment-resistant cutaneous vasculitis that was initially suspected to be associated with a gene variant in SH2D1A. Whole-exome sequencing was performed to identify the genetic defect. Molecular and functional analyses were performed to assess the impact of variants on proteasomal function. The immune characterization led to the decision to perform HSCT on our patient and conduct follow-up over the 7-year period after the transplant. Because loss of myeloid chimerism after the first HSCT was associated with relapse of autoinflammation, a second HSCT was performed. After the successful second HSCT, the patient developed mild symptoms of lipodystrophy, which raised the suspicion of a PRAAS. Genetic analysis revealed 2 novel heterozygous variants in PSMB4 (encoding proteasomal subunit β7). Retrospective analysis of patient cells stored before the first HSCT and patient cells obtained after the second HSCT demonstrated that HSCT successfully rescued proteasome function, restored protein homeostasis, and resolved the interferon-stimulated gene signature. Furthermore, successful HSCT alleviated the autoinflammatory manifestations in our patient. Patients with treatment-resistant PRAAS can be cured by HSCT. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Maize, expressing Cry1Ab insecticidal proteins produced by the bacterium Bacillus thuringiensis (Bt), was introduced for control of Busseola fusca (Fuller) (Lepidoptera: Noctuidae) and Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) in South Africa in 1998. In the light of the reportedly lower toxicity of Bt maize to certain noctuid borers, the effect of Bt maize was evaluated on Sesamia calamistis (Hampson) (Lepidoptera: Noctuidae) in South Africa. The characteristic larval behaviour of S. calamistis may result in reduced exposure to Bt toxin and subsequent high levels of survival since larvae do not feed on plant whorls like other borer species, but penetrate stems directly from behind leaf sheaths. Growth and survival of larvae were determined in a greenhouse bioassay with two Bt maize hybrids (Monsanto event MON810 and Syngenta event Bt11) and their non-Bt, isoline hybrids. Potted plants were artificially infested with 1st instar larvae. Percentage larval survival and mean larval mass were recorded over time. Bt maize of both events was shown to be highly toxic to S. calamistis. No larvae survived longer than 9 days on plants of either of the Bt events. S. calamistis is stenophagous and occurs in mixed populations with other borer species, with which it shares several parasitoid species in Africa. The ecological impact of local extinction of S. calamistis caused by this highly effective transgenic event is therefore not expected to be great. [Copyright &y& Elsevier]

Abstract: The groundnut leafminer (GLM), Aproaerema modicella (Deventer) (Lepidoptera: Gelechiidae), is an important pest of groundnut in India and some parts of Africa. This is the first study examining the levels of infestation and rates of parasitization of this pest on groundnut in South Africa. A general survey was done of GLM parasitoids at several sites in the groundnut production areas together with a 2-year study of GLM infestation and parasitism levels at the Tshiombo irrigation scheme. GLM larvae or pupae on infested groundnut leaves were collected and held for emergence of moths or parasitoids. Nine species of parasitic Hymenoptera parasitized GLM immatures, which was low in comparison to the large number of parasitoids known to attack the pest in Asia, the origin of the pest. Hypomicrogaster sp. (Braconidae) and Baryscapus sp. (Eulophidae) were recorded for the first time on GLM. Larval parasitization rates ranged between 3.7 and 54.2% and pupal parasitization rates ranged between 4.8 and 43.7%. Mean infestation levels of GLM (larvae and pupae) were between 1.2 and 1.9 (SE ±0.6) per plant during 2006 and 1.0 and 26.9 (SE ±2.8) per plant during 2007. In the second year of the study, the economic threshold for this pest, between 2 and 10 larvae per plant, was surpassed indicating that GLM is an important economic pest on groundnut in South Africa. [Copyright &y& Elsevier]

Abstract: During the past two decades, panicle-feeding Hemiptera (head bugs) became serious pests of sorghum in West and Central Africa. Of the more than 100 sorghum insect pests reported in Africa, 42 species are reported to be panicle-feeding pests. Prior to this study, no research had been done on the panicle-feeding Hemiptera in South Africa. The objectives of the study were to determine the abundance and diversity of panicle-feeding Hemiptera on sorghum. Surveys were conducted between November 2004 and June 2006 at 26 sites in four provinces of South Africa. Collection was done using a plastic bag method and a D-Vac. A checklist was compiled and the temporal distribution of different Hemiptera species determined during panicle development. The total number of adults and nymphs collected during this study was 23,798. Thirty-nine herbivorous Hemiptera species were collected. The most abundant family was the Miridae followed by the Lygaeidae, which made up 41% and 17%, respectively, of the total number of individuals. Eurystylus bellevoyi, Campylomma sp., Creontiades pallidus, Nysius natalensis, Nezara viridula and Sthenaridea suturalis were the most abundant species and also occurred widely in the sorghum production area. Infestation levels of these species were generally low compared with those in other parts of Africa, but comparatively high infestation levels were observed at some sites. There was no clear distinction between the different panicle development stages during which panicles were infested by different species. The general tendency was that nearly all species were present from the flowering stage onwards and that numbers declined when grain hardened. [Copyright &y& Elsevier]

Policy-related research in general, and impact assessments in particular, are too loosely connected to decision-making processes. The result is often sub-optimal or even undesirable, as one of two situations arises: (1) much research is done; however, those with the real power to make decisions do not make use of all of the resulting information, or (2) advocates of contrary opinions struggle with each other, using policy-related research as ammunition. To avoid these unwanted situations, the connection between the world of knowledge and the world of decision-making should be carefully constructed, by connecting the process of decision-making to the academic research and carefully developing research goals in response to the demands of decision-makers. By making these connections in a stepwise manner, knowledge may generate new insights and views for involved decision-makers and stakeholders, thus changing perceptions and problem definitions. In this way, these actors learn about the possibilities of several alternatives as well as each other''s perceptions, and thus can make educated decisions leading to the most desirable and socially acceptable solution. The way this proposed method works is illustrated using two cases in The Netherlands: the project “Mainport Rotterdam” (the enlargement of the port of Rotterdam), the project “A fifth runway for Amsterdam Airport (Schiphol)”. [Copyright &y& Elsevier]

Bioelectrical impedance analysis (BIA) is a simple technique for determining body water and calculating body composition. It has been validated in healthy control subjects but not in patients with liver disease. We examined the ability of BIA to detect changes in total body water (TBW) due to removal of ascites. In 12 cirrhotic patients, BIA of the whole body and of body segments was performed before and after treatment of ascites with paracentesis (n = 12) and diuretics (n = 2). TBW changes predicted by BIA, by using two prediction equations, were significantly less than body weight changes (51% and 45% of the weight loss). BIA of body segments showed highly significant changes in both the trunk and the leg and small changes in the arm. These data indicate that BIA of the whole body is not a suitable technique for monitoring fluid changes in cirrhotic patients with ascites. Changes in BIA ofbody segments may be due to mobilization of edema after the removal of ascites. [ABSTRACT FROM AUTHOR]

Objectives: To assess the capability of the pixel-by-pixel DCE-MRI time intensity curve (TIC)-shape analysis method in the evaluation of juvenile idiopathic arthritis (JIA) disease activity by correlating DCE-MRI parameters with semi-quantitative conventional-MRI scores of synovitis.Methods: Clinical, laboratory, and (DCE)-MRI datasets of 85 JIA patients were prospectively obtained. TIC-shapes of each voxel were classified into one of seven predefined color-coded TIC shape categories. Spatial information on the relative amount of TIC-shapes, maximal enhancement (ME), maximal initial slope (MIS), initial area under the curve (iAUC), time-to-peak (TTP), enhancing volume (EV) was calculated of the synovial membrane. The grade of synovitis was scored on conventional MR images by two readers using the validated JAMRIS system. The Bonferroni method was used to correct for multiple testing, therefore, a P value of <0.0056 is considered significant (0.05/9=0.0056).Results: The semi-quantitative JAMRIS synovitis score correlated substantially with the ME, EV, and iAUC (Rs=0.658, P<0.001; Rs=0.618, P<0.001; Rs=0.639, P<0.001), and moderately with MIS (Rs=0.453, P<0.001). A poor correlation was observed between the relative number of TIC-shapes 2-5 and the JAMRIS synovitis score (Rs=0.209, P=0.054; Rs=0.328, P=0.002; Rs=0.241, P=0.023; Rs=-0.241, P=0.026).Conclusion: In this explorative study, both TIC shape and semi-quantitative DCE-MRI analysis methods showed moderate to substantial correlations with conventional MRI scores of disease activity, indicating that this methods are feasible. Further research is warranted whether DCE-MRI holds potential to become an objective and quantitative method for the evaluation of disease activity in JIA. [ABSTRACT FROM AUTHOR]