Cationic carbosilane dendrimers and oligonucleotide binding: an energetic affair

GENERATION 2 CATIONIC CARBOSILANE DENDRIMERS HOLD GREAT PROMISE AS INTERNALIZING AGENTS FOR GENE THERAPY AS THEY PRESENT LOW TOXICITY AND RETAIN AND INTERNALIZE GENETIC MATERIAL AS OLIGONUCLEOTIDE OR SIRNA. IN THIS WORK WE CARRIED OUT A COMPLETE IN SILICO STRUCTURAL AND ENERGETICAL CHARACTERIZATION OF THE INTERACTIONS OF A SET OF 2G CARBOSILANE DENDRIMERS, SHOWING DIFFERENT AFFINITY TOWARDS TWO SINGLE STRAND OLIGONUCLEOTIDE (ODN) SEQUENCES IN VITRO. OUR SIMULATIONS PREDICT THAT THESE FOUR DENDRIMERS AND THE RELEVANT ODN COMPLEXES ARE CHARACTERIZED BY SIMILAR SIZE AND SHAPE, AND THAT THE MOLECULE-SPECIFIC ODN BINDING ABILITY CAN BE RATIONALIZED ONLY CONSIDERING A CRITICAL MOLECULAR DESIGN PARAMETER: THE NORMALIZED EFFECTIVE BINDING ENERGY \u394GBIND,EFF/NEFF I.E., THE PERFORMANCE OF EACH ACTIVE INDIVIDUAL DENDRIMER BRANCH DIRECTLY INVOLVED IN A BINDING INTERACTIO

The Ant mimic, Myrmarachne Plataleoides

Volume: XI

Identification of novel non-myelin biomarkers in multiple sclerosis using an improved phage-display approach

Although the etiology of multiple sclerosis is not yet understood, it is accepted that its pathogenesis involves both autoimmune and neurodegenerative processes, in which the role of autoreactive T-cells has been elucidated. Instead, the contribution of humoral response is still unclear, even if the presence of intrathecal antibodies and B-cells follicle-like structures in meninges of patients has been demonstrated. Several myelin and non-myelin antigens have been identified, but none has been validated as humoral biomarker. In particular autoantibodies against myelin proteins have been found also in healthy individuals, whereas non-myelin antigens have been implicated in neurodegenerative phase of the disease. To provide further putative autoantigens of multiple sclerosis, we investigated the antigen specificity of immunoglobulins present both in sera and in cerebrospinal fluid of patients using phage display technology in a new improved format. A human brain cDNA phage display library was constructed and enriched for open-read-frame fragments. This library was selected against pooled and purified immunoglobulins from cerebrospinal fluid and sera of multiple sclerosis patients. The antigen library was also screened against an antibody scFv library obtained from RNA of B cells purified from the cerebrospinal fluid of two relapsing remitting patients. From all biopanning a complex of 14 antigens were identified; in particular, one of these antigens, corresponding to DDX24 protein, was present in all selections. The ability of more frequently isolated antigens to discriminate between sera from patients with multiple sclerosis or other neurological diseases was investigated. The more promising novel candidate autoantigens were DDX24 and TCERG1. Both are implicated in RNA modification and regulation which can be altered in neurodegenerative processes. Therefore, we propose that they could be a marker of a particular disease activity state

Pteridine-2,4-diamine derivatives as radical scavengers and inhibitors of lipoxygenase that can possess anti-inflammatory properties

BACKGROUND: Reactive oxygen species are associated with inflammation implicated in cancer, atherosclerosis and autoimmune diseases. The complex nature of inflammation and of oxidative stress suggests that dual-target agents may be effective in combating diseases involving reactive oxygen species. RESULTS: A novel series of N-substituted 2,4-diaminopteridines has been synthesized and evaluated as antioxidants in several assays. Many exhibited potent lipid antioxidant properties, and some are inhibitors of soybean lipoxygenase, IC50 values extending down to 100 nM for both targets. Several pteridine derivatives showed efficacy at 0.01 mmol/kg with little tissue damage in a rat model of colitis. 2-(4-methylpiperazin-1-yl)-N-(thiophen-2-ylmethyl)pteridin-4-amine (18f) at 0.01 mmol/kg exhibited potent anti-inflammatory activity (reduction by 41%). CONCLUSION: The 2,4-diaminopteridine core represents a new scaffold for lipoxygenase inhibition as well as sustaining anti-inflammatory properties

Risk of seizure recurrence in people with single seizures and early epilepsy - Model development and external validation

PURPOSE: Following a single seizure, or recent epilepsy diagnosis, it is difficult to balance risk of medication side effects with the potential to prevent seizure recurrence. A prediction model was developed and validated enabling risk stratification which in turn informs treatment decisions and individualises counselling. METHODS: Data from a randomised controlled trial was used to develop a prediction model for risk of seizure recurrence following a first seizure or diagnosis of epilepsy. Time-to-event data was modelled via Cox's proportional hazards regression. Model validity was assessed via discrimination and calibration using the original dataset and also using three external datasets - National General Practice Survey of Epilepsy (NGPSE), Western Australian first seizure database (WA) and FIRST (Italian dataset of people with first tonic-clonic seizures). RESULTS: People with neurological deficit, focal seizures, abnormal EEG, not indicated for CT/MRI scan, or not immediately treated have a significantly higher risk of seizure recurrence. Discrimination was fair and consistent across the datasets (c-statistics: 0.555 (NGPSE); 0.558 (WA); 0.597 (FIRST)). Calibration plots showed good agreement between observed and predicted probabilities in NGPSE at one and three years. Plots for WA and FIRST showed poorer agreement with the model underpredicting risk in WA, and over-predicting in FIRST. This was resolved following model recalibration. CONCLUSION: The model performs well in independent data especially when recalibrated. It should now be used in clinical practice as it can improve the lives of people with single seizures and early epilepsy by enabling targeted treatment choices and more informed patient counselling

Seizure first aid training for people with epilepsy attending emergency departments and their significant others: the SAFE intervention and feasibility RCT

Background No seizure first aid training intervention exists for people with epilepsy who regularly attend emergency departments and their significant others, despite such an intervention’s potential to reduce clinically unnecessary and costly visits. Objectives The objectives were to (1) develop Seizure first Aid training For Epilepsy (SAFE) by adapting a broader intervention and (2) determine the feasibility and optimal design of a definitive randomised controlled trial to test SAFE’s efficacy. Design The study involved (1) the development of an intervention informed by a co-design approach with qualitative feedback and (2) a pilot randomised controlled trial with follow-ups at 3, 6 and 12 months and assessments of treatment fidelity and the cost of SAFE’s delivery. Setting The setting was (1) third-sector patient support groups and professional health-care organisations and (2) three NHS emergency departments in England. Participants Participants were (1) people with epilepsy who had visited emergency departments in the prior 2 years, their significant others and emergency department, paramedic, general practice, commissioning, neurology and nursing representatives and (2) people with epilepsy aged ≥ 16 years who had been diagnosed for ≥ 1 year and who had made two or more emergency department visits in the prior 12 months, and one of their significant others. Emergency departments identified ostensibly eligible people with epilepsy from attendance records and patients confirmed their eligibility. Interventions Participants in the pilot randomised controlled trial were randomly allocated 1 : 1 to SAFE plus treatment as usual or to treatment as usual only. Main outcome measures Consent rate and availability of routine data on emergency department use at 12 months were the main outcome measures. Other measures of interest included eligibility rate, ease with which people with epilepsy could be identified and routine data secured, availability of self-reported emergency department data, self-reported emergency department data’s comparability with routine data, SAFE’s effect on emergency department use, and emergency department use in the treatment as usual arm, which could be used in sample size calculations. Results (1) Nine health-care professionals and 23 service users provided feedback that generated an intervention considered to be NHS feasible and well positioned to achieve its purpose. (2) The consent rate was 12.5%, with 53 people with epilepsy and 38 significant others recruited. The eligibility rate was 10.6%. Identifying people with epilepsy from attendance records was resource intensive for emergency department staff. Those recruited felt more stigmatised because of epilepsy than the wider epilepsy population. Routine data on emergency department use at 12 months were secured for 94.1% of people with epilepsy, but the application process took 8.5 months. Self-reported emergency department data were available for 66.7% of people with epilepsy, and people with epilepsy self-reported more emergency department visits than were captured in routine data. Most participants (76.9%) randomised to SAFE received the intervention. The intervention was delivered with high fidelity. No related serious adverse events occurred. Emergency department use at 12 months was lower in the SAFE plus treatment as usual arm than in the treatment as usual only arm, but not significantly so. Calculations indicated that a definitive trial would need ≈ 674 people with epilepsy and ≈ 39 emergency department sites. Limitations Contrary to patient statements on recruitment, routine data secured at the pilot trial’s end indicated that ≈ 40% may not have satisfied the inclusion criterion of two or more emergency department visits. Conclusions An intervention was successfully developed, a pilot randomised controlled trial conducted and outcome data secured for most participants. The consent rate did not satisfy a predetermined ‘stop/go’ level of ≥ 20%. The time that emergency department staff needed to identify eligible people with epilepsy is unlikely to be replicable. A definitive trial is currently not feasible. Future work Research to more easily identify and recruit people from the target population is required. Trial registration Current Controlled Trials ISRCTN13871327. Funding This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 8, No. 39. See the NIHR Journals Library website for further project information

Benznidazole in cerebrospinal fluid: A case series of chagas disease meningoencephalitis in hiv-positive patients

Chagas disease reactivation in HIV-positive people is an opportunistic infection with 79 to 100% mortality. It commonly involves the central nervous system (CNS). Early treatment with trypanocidal drugs such as benznidazole (BNZ) is crucial for this severe manifestation of Trypanosoma cruzi infection. However, limited BNZ clinical pharmacology data are available, especially its concentration in the CNS. We report a series of HIV-positive patients undergoing treatment for T. cruzi meningoencephalitis, their clinical response, and cerebrospinal fluid (CSF) and plasma BNZ concentrations. Measurements were carried out using leftover samples originally obtained for routine medical care. A high-performance liquid chromatography/tandem mass spectrometry bioanalytical method designed for BNZ plasma measurements was adapted and validated for CSF samples. Six patients were enrolled in this study from 2015 to 2019. A total of 6 CSF and 19 plasma samples were obtained. Only three of the CSF samples had detectable BNZ levels, all under 1mg/ml. Fifteen plasma samples had detectable BNZ, and 13 were above 2mg/ml, which is the putative trypanocidal level. We observed BNZ concentrations in human CSF and plasma. CSF BNZ concentrations were low or not measurable in all patients, suggesting that the usual BNZ doses may be suboptimal in HIV-positive patients with T. cruzi meningoencephalitis. While drug-drug and drug-disease interactions may be in part responsible, the factors leading to low CSF BNZ levels remain to be studied in detail. These findings highlight the potential of therapeutic drug monitoring in BNZ treatment and suggest that the use of higher doses may be useful for Chagas disease CNS reactivations