HPLC on chiral support with polarimetric detection: application to conglomerate discovery

In conglomerates, each single crystal contains only one of the two possible enantiomeric forms--either dextrorotatory or levorotatory. The analysis of a single crystal by liquid chromatography on chiral support associated with chiroptical detection is a very efficient tool to reveal the occurrence of a conglomerate. In terms of rapidity and easiness, this method compares favorably with the classical methods used to show this occurrence. Two examples are provided.     

Interleukin 1/Toll-like Receptor-induced Autophosphorylation Activates Interleukin 1 Receptor-associated Kinase 4 and Controls Cytokine Induction in a Cell Type-specific Manner

IRAK4 is a central kinase in innate immunity, but the role of its kinase activity is controversial. The mechanism of activation for IRAK4 is currently unknown, and little is known about the role of IRAK4 kinase in cytokine production, particularly in different human cell types. We show IRAK4 autophosphorylation occurs by an intermolecular reaction and that autophosphorylation is required for full catalytic activity of the kinase. Phosphorylation of any two of the residues Thr-342, Thr-345, and Ser-346 is required for full activity, and the death domain regulates the activation of IRAK4. Using antibodies against activated IRAK4, we demonstrate that IRAK4 becomes phosphorylated in human cells following stimulation by IL-1R and Toll-like receptor agonists, which can be blocked pharmacologically by a dual inhibitor of IRAK4 and IRAK1. Interestingly, in dermal fibroblasts, although complete inhibition of IRAK4 kinase activity does not inhibit IL-1-induced IL-6 production, NF-κB, or MAPK activation, there is complete ablation of these processes in IRAK4-deficient cells. In contrast, the inhibition of IRAK kinase activity in primary human monocytes reduces R848-induced IL-6 production with minimal effect on NF-κB or MAPK activation. Taken together, these studies define the mechanism of IRAK4 activation and highlight the differential role of IRAK4 kinase activity in different human cell types as well as the distinct roles IRAK4 scaffolding and kinase functions play.     

Effects of an Immunosuppressive Treatment in the GRMD Dog Model of Duchenne Muscular Dystrophy

The GRMD (Golden retriever muscular dystrophy) dog has been widely used in pre-clinical trials targeting DMD (Duchenne muscular dystrophy), using in many cases a concurrent immune-suppressive treatment. The aim of this study is to assess if such a treatment could have an effect on the disease course of these animals. Seven GRMD dogs were treated with an association of cyclosporine A (immunosuppressive dosage) and prednisolone (2 mg/kg/d) during 7 months, from 2 to 9 months of age. A multi-parametric evaluation was performed during this period which allowed us to demonstrate that this treatment had several significant effects on the disease progression. The gait quality as assessed by 3D-accelerometry was dramatically improved. This was consistent with the evolution of other parameters towards a significant improvement, such as the clinical motor score, the post-tetanic relaxation and the serum CK levels. In contrast the isometric force measurement as well as the histological evaluation argued in favor of a more severe disease progression. In view of the disease modifying effects which have been observed in this study it should be concluded that immunosuppressive treatments should be used with caution when carrying out pre-clinical studies in this canine model of DMD. They also highlight the importance of using a large range of multi-parametric evaluation tools to reliably draw any conclusion from trials involving dystrophin-deficient dogs, which reproduce the complexity of the human disease.     

Multi-center evaluation of post-operative morbidity and mortality after optimal cytoreductive surgery for advanced ovarian cancer

Purpose

While optimal cytoreduction is the standard of care for advanced ovarian cancer, the related post-operative morbidity has not been clearly documented outside pioneering centers. Indeed most of the studies are monocentric with inclusions over several years inducing heterogeneity in techniques and goals of surgery. We assessed the morbidity of optimal cytoreduction surgery for advanced ovarian cancer within a short inclusion period in 6 referral centers dedicated to achieve complete cytoreduction.

Patients and Methods

The 30 last optimal debulking surgeries of 6 cancer centers were included. Inclusion criteria included: stage IIIc- IV ovarian cancer and optimal surgery performed at the site of inclusion. All post-operative complications within 30 days of surgery were recorded and graded using the Memorial secondary events grading system. Student-t, Chi2 and non-parametric statistical tests were performed.

Results

180 patients were included. There was no demographic differences between the centers. 63 patients underwent surgery including intestinal resections (58 recto-sigmoid resection), 24 diaphragmatic resections, 17 splenectomies. 61 patients presented complications; One patient died post-operatively. Major (grade 3–5) complications requiring subsequent surgeries occurred in 21 patients (11.5%). 76% of patients with a major complication had undergone an ultraradical surgery (P = 0.004).

Conclusion

While ultraradical surgery may result in complete resection of peritoneal disease in advanced ovarian cancer, the associated complication rate is not negligible. Patients should be carefully evaluated and the timing of their surgery optimized in order to avoid major complications.     

Two dual-specific (anti-IgG and anti-dsDNA) monoclonal autoantibodies derived from the NZB/NZW F1 recognize an epitope in the hinge region

The anti-IgG properties of two dual-specific (anti-dsDNA and anti-IgG) monoclonal NZB/NZW F1-derived autoantibodies, BV 17–45 and BV 16–13, were studied to resolve the location and possible commonality of the IgG epitope. To determine if BV 17–45 and BV 16–13 recognized the same IgG epitope, the relative temperature sensitivity of the conformational IgG epitopes were evaluated using the conformational sensitive immunoassay. Comparison of the temperature sensitivity of the conformational immunoglobulin epitopes over a temperature range of 25–100°C suggested that the epitope recognized by BV 17–45 was the same as the IgG epitope recognized by BV 16–13. Further studies with papain- and pepsin-generated F(ab′)₂, Fab, and Fc fragments of BV 17–45 and BV 16–13 revealed that the dual-specific autoantibodies BV 17–45 and BV 16–13 both bound an epitope in the hinge region of the IgG molecule. The potential correlation between these studies and the pathogenic nature of dual-specific autoantibodies is discussed.     

Can we make participatory NTFP monitoring work? Lessons learnt from the development of a multi-stakeholder system in Northern Laos

Monitoring natural resources is essential for their successful and sustainable management. Community participation should enable local people to take ownership of the monitoring and ensure that it is cost-effective. But even then, success is often elusive. We developed a participatory Non Timber Forest Product (NTFP) monitoring system in 6 upland villages of Luang Prabang Province, Lao PDR, using focus group discussions, interviews, village meetings and direct observations. We used simple approaches to select resources, discuss issues, and develop a cost-effective NTFP monitoring system. Communities usually relied on shifting cultivation, fishing and collection of NTFPs. Gold mining activities affected livelihoods in three villages, which had better access to markets. Participatory monitoring looks less successful when external economic pressures or a major environmental threat disturbs local livelihoods. In the case of gold mining, we observed the prioritization of villagers’ activities towards this sudden new economic opportunity. In contrast, communities not impacted by mining participated more actively in data collection. They understood how the data could be used to influence the local government, to achieve more beneficial land management for all stakeholders concerned. We believe that participatory NTFP monitoring can work and is an important tool for decision-making and economic empowerment for local communities. We identified the conditions under which participatory NTFP monitoring could work: reaching a shared understanding of what needs to be monitored and how; testing and refining a simple monitoring system; and integrating local government concerns with those of other stakeholders.     

Whole-exome-sequencing-based discovery of human FADD deficiency

Germline mutations in FASL and FAS impair Fas-dependent apoptosis and cause recessively or dominantly inherited autoimmune lymphoproliferative syndrome (ALPS). Patients with ALPS typically present with no other clinical phenotype. We investigated a large, consanguineous, multiplex kindred in which biological features of ALPS were found in the context of severe bacterial and viral disease, recurrent hepatopathy and encephalopathy, and cardiac malformations. By a combination of genome-wide linkage and whole-exome sequencing, we identified a homozygous missense mutation in FADD, encoding the Fas-associated death domain protein (FADD), in the patients. This FADD mutation decreases steady-state protein levels and impairs Fas-dependent apoptosis in vitro, accounting for biological ALPS phenotypes in vivo. It also impairs Fas-independent signaling pathways. The observed bacterial infections result partly from functional hyposplenism, and viral infections result from impaired interferon immunity. We describe here a complex clinical disorder, its genetic basis, and some of the key mechanisms underlying its pathogenesis. Our findings highlight the key role of FADD in Fas-dependent and Fas-independent signaling pathways in humans.     

Mutations in the TGFβ binding-protein-like domain 5 of FBN1 are responsible for acromicric and geleophysic dysplasias

Geleophysic (GD) and acromicric dysplasia (AD) belong to the acromelic dysplasia group and are both characterized by severe short stature, short extremities, and stiff joints. Although AD has an unknown molecular basis, we have previously identified ADAMTSL2 mutations in a subset of GD patients. After exome sequencing in GD and AD cases, we selected fibrillin 1 (FBN1) as a candidate gene, even though mutations in this gene have been described in Marfan syndrome, which is characterized by tall stature and arachnodactyly. We identified 16 heterozygous FBN1 mutations that are all located in exons 41 and 42 and encode TGFβ-binding protein-like domain 5 (TB5) of FBN1 in 29 GD and AD cases. Microfibrillar network disorganization and enhanced TGFβ signaling were consistent features in GD and AD fibroblasts. Importantly, a direct interaction between ADAMTSL2 and FBN1 was demonstrated, suggesting a disruption of this interaction as the underlying mechanism of GD and AD phenotypes. Although enhanced TGFβ signaling caused by FBN1 mutations can trigger either Marfan syndrome or GD and AD, our findings support the fact that TB5 mutations in FBN1 are responsible for short stature phenotypes.     

Inherited MST1 Deficiency Underlies Susceptibility to EV-HPV Infections

Epidermodysplasia verruciformis (EV) is characterized by persistent cutaneous lesions caused by a specific group of related human papillomavirus genotypes (EV-HPVs) in otherwise healthy individuals. Autosomal recessive (AR) EVER1 and EVER2 deficiencies account for two thirds of known cases of EV. AR RHOH deficiency has recently been described in two siblings with EV-HPV infections as well as other infectious and tumoral manifestations. We report here the whole-exome based discovery of AR MST1 deficiency in a 19-year-old patient with a T-cell deficiency associated with EV-HPV, bacterial and fungal infections. MST1 deficiency has recently been described in seven patients from three unrelated kindreds with profound T-cell deficiency and various viral and bacterial infections. The patient was also homozygous for a rare ERCC3 variation. Our findings broaden the clinical range of infections seen in MST1 deficiency and provide a new genetic etiology of susceptibility to EV-HPV infections. Together with the recent discovery of RHOH deficiency, they suggest that T cells are involved in the control of EV-HPVs, at least in some individuals.