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1.  Tandem Dienone-Photorearrangement-Cycloaddition for the Rapid Generation of Molecular Complexity 
Journal of the American Chemical Society  2013;135(47):17978-17982.
A tandem dienone-photorearrangement-cycloaddition (DPC) reaction of novel cyclohexadienone substrates tethered with various 2π and 4π reaction partners resulted in the formation of polycyclic, bridged frameworks. In particular, use of alkynyl ether-tethered substrates led to (3+2) cycloaddition to afford strained alkenes which could be further elaborated by intra- and intermolecular cycloaddition chemistry to produce complex, polycyclic chemotypes.
PMCID: PMC3964885  PMID: 24161069
2.  Disk degeneration of the upper lumbar disks is associated with hip pain 
European Spine Journal  2012;22(4):721-726.
A possible cause of hip pain is the presence of radiating pain from the higher lumbar spine. Identification of factors associated with hip pain arising from the lumbar spine would aid the physician. The first step in identifying possible factors is to look at the association between hip pain and osteoarthritis of the lumbar spine.
In an open population based study of people 55 years and older (Rotterdam study), 2,819 lumbar radiographs were scored for the presence and severity of individual radiographic features of disk degeneration. Hip osteoarthritis was scored on anteroposterior pelvic radiographs, and questionnaires including self-reported hip pain were taken. Logistic regression adjusted for possible confounders was used to determine the association between self-reported hip pain and the individual radiographic features of lumbar disk degeneration.
The presence of dis space narrowing grade ≥1 at level L1/L2 was significantly associated with hip pain in the last month (men OR = 2.0; 95 % CI 1.1–3.8 and women OR = 1.7; 95 % CI 1.1–2.5). The presence of disk space narrowing grade ≥1 at level L2/L3 was only significantly associated with hip pain in women. The strength of the associations increased for self-reported chronic hip pain, especially in men (L1/L2 OR = 2.5; 95 % CI 1.3–5.0). The presence of disk space narrowing at the lower levels (L3/L4/L5/S1) was not significantly associated with hip pain.
Our data provide evidence for an association between hip pain and disk space narrowing at disk level L1/L2 and L2/L3. In case of uncertainty of the cause of hip pain, evaluation of lumbar radiographs may help to identify those hip pain patients who might have pain arising from the lumbar spine.
PMCID: PMC3631034  PMID: 23135791
Hip pain; Back pain; Lumbar disk degeneration
3.  Delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) Shows No Change in Cartilage Structural Composition after Viscosupplementation in Patients with Early-Stage Knee Osteoarthritis 
PLoS ONE  2013;8(11):e79785.
Viscosupplementation with hyaluronic acid (HA) of osteoarthritic (OA) knee joints has a well-established positive effect on clinical symptoms. This effect, however, is only temporary and the working mechanism of HA injections is not clear. It was suggested that HA might have disease modifying properties because of its beneficial effect on cartilage sulphated glycosaminoglycan (sGAG) content. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) is a highly reproducible, non-invasive surrogate measure for sGAG content and hence composition of cartilage. The aim of this study was to assess whether improvement in cartilage structural composition is detected using dGEMRIC 14 weeks after 3 weekly injections with HA in patients with early-stage knee OA.
In 20 early-stage knee OA patients (KLG I-II), 3D dGEMRIC at 3T was acquired before and 14 weeks after 3 weekly injections with HA. To evaluate patient symptoms, the knee injury and osteoarthritis outcome score (KOOS) and a numeric rating scale (NRS) for pain were recorded. To evaluate cartilage composition, six cartilage regions in the knee were analyzed on dGEMRIC. Outcomes of dGEMRIC, KOOS and NRS before and after HA were compared using paired t-testing. Since we performed multiple t-tests, we applied a Bonferroni-Holm correction to determine statistical significance for these analyses.
All KOOS subscales (‘pain’, ‘symptoms’, ‘daily activities’, ‘sports’ and ’quality of life’) and the NRS pain improved significantly 14 weeks after Viscosupplementation with HA. Outcomes of dGEMRIC did not change significantly after HA compared to baseline in any of the cartilage regions analyzed in the knee.
Our results confirm previous findings reported in the literature, showing persisting improvement in symptomatic outcome measures in early-stage knee OA patients 14 weeks after Viscosupplementation. Outcomes of dGEMRIC, however, did not change after Viscosupplementation, indicating no change in cartilage structural composition as an explanation for the improvement of clinical symptoms.
PMCID: PMC3819245  PMID: 24223194
4.  Human rotavirus vaccine Rotarix™ provides protection against diverse circulating rotavirus strains in African infants: a randomized controlled trial 
BMC Infectious Diseases  2012;12:213.
Rotaviruses are the most important cause of severe acute gastroenteritis worldwide in children <5 years of age. The human, G1P[8] rotavirus vaccine Rotarix™ significantly reduced severe rotavirus gastroenteritis episodes in a Phase III clinical trial conducted in infants in South Africa and Malawi. This paper examines rotavirus vaccine efficacy in preventing severe rotavirus gastroenteritis, during infancy, caused by the various G and P rotavirus types encountered during the first rotavirus-season.
Healthy infants aged 5–10 weeks were enrolled and randomized into three groups to receive either two (10 and 14 weeks) or three doses of Rotarix™ (together forming the pooled Rotarix™ group) or three doses of placebo at a 6,10,14-week schedule. Weekly home visits were conducted to identify gastroenteritis episodes. Rotaviruses were detected by ELISA and genotyped by RT-PCR and nucleotide sequencing. The percentage of infants with severe rotavirus gastroenteritis caused by the circulating G and P types from 2 weeks post-last dose until one year of age and the corresponding vaccine efficacy was calculated with 95% CI.
Overall, 4939 infants were vaccinated and 4417 (pooled Rotarix™ = 2974; placebo = 1443) were included in the per protocol efficacy cohort. G1 wild-type was detected in 23 (1.6%) severe rotavirus gastroenteritis episodes from the placebo group. This was followed in order of detection by G12 (15 [1%] in placebo) and G8 types (15 [1%] in placebo). Vaccine efficacy against G1 wild-type, G12 and G8 types were 64.1% (95% CI: 29.9%; 82%), 51.5% (95% CI:-6.5%; 77.9%) and 64.4% (95% CI: 17.1%; 85.2%), respectively. Genotype P[8] was the predominant circulating P type and was detected in 38 (2.6%) severe rotavirus gastroenteritis cases in placebo group. The remaining circulating P types comprised of P[4] (20 [1.4%] in placebo) and P[6] (13 [0.9%] in placebo). Vaccine efficacy against P[8] was 59.1% (95% CI: 32.8%; 75.3%), P[4] was 70.9% (95% CI: 37.5%; 87.0%) and P[6] was 55.2% (95% CI: -6.5%; 81.3%)
Rotarix™ vaccine demonstrated efficacy against severe gastroenteritis caused by diverse circulating rotavirus types. These data add to a growing body of evidence supporting heterotypic protection provided by Rotarix™.
Trial registration number
PMCID: PMC3462149  PMID: 22974466
5.  Effect of Arthritic Synovial Fluids on the Expression of Immunomodulatory Factors by Mesenchymal Stem Cells: An Explorative in vitro Study 
Background: In diseased joints, the catabolic environment results in progressive joint damage. Mesenchymal stem cells (MSCs) can have immunomodulatory effects by secreting anti-inflammatory factors. To exert these effects, MSCs need to be triggered by pro-inflammatory cytokines. To explore the potential of MSCs as a treatment for diseased joints, we studied the effect of synovial fluid (SF) from donors with different joint diseases and donors without joint pathology on the immunomodulatory capacities of human MSCs in vitro. We hypothesized that SF of diseased joints influences the immunomodulatory effects of MSCs. Materials and Methods: MSCs were cultured in medium with SF of six osteoarthritis (OA) or six rheumatoid arthritis (RA) donors and three donors without joint pathology were used as control. Gene expressions of IL-6, HGF, TNFa, TGFb1, and indoleamine 2,3-dioxygenase (IDO) were analyzed. l-kynurenine concentration in conditioned medium (CM) by MSCs with SF was determined as a measure of IDO activity by MSCs. Furthermore, the effect of CM with SF on proliferation of activated lymphocytes was analyzed. Results: Addition of SF significantly up-regulated the mRNA expression of IL-6 and IDO in MSCs. SF(OA) induced significantly higher expression of IDO than SF(control), although no difference in IDO activity of the MSCs could be shown with a l-kynurenine assay. Medium conditioned by MSCs with SF(OA or RA) suppressed activated lymphocyte proliferation in vitro more than medium conditioned by MSCs without SF or with SF(control). Discussion: SF can influence the expression of genes involved in immunomodulation by MSCs and the effect on lymphocyte proliferation. We found indications for disease-specific differences between SFs but the variation between donors, even within one disease group was high. These data warrant further research to examine the potential application of MSC therapy in arthritic joints.
PMCID: PMC3410447  PMID: 22876244
MSC; osteoarthritis; rheumatoid arthritis; synovial fluid; immunomodulation
6.  Floating Filters, a Novel Technique for Isolation and Enumeration of Fastidious, Acidophilic, Iron-Oxidizing, Autotrophic Bacteria 
Nuclepore polycarbonate filters floating on a liquid, FeSO4-containing medium (pH 1.6) were used to isolate a moderately thermophilic bacterium from a pyrite-oxidizing enrichment culture. The isolate failed to grow on any of the conventional solid media tried. To test the general applicability of the method, the enumeration of a fastidious acidophilic organism, Thiobacillus ferrooxidans, was carried out and the results compared with those obtained with other filters, solid media, and the most probable number technique. T. ferrooxidans showed better viability on the floating polycarbonate filters and grew in a much shorter time (4 to 5 days) than with the other techniques.
PMCID: PMC184860  PMID: 16348297

Results 1-6 (6)