Optical coherence tomography in central nervous system demyelinating diseases related optic neuritis

AIM: To compare the thickness of the peripapillary retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) among patients with various forms of optic neuritis (ON) and to identify whether any particular parameters or their thinning pattern can be used to distinguish the type of ON. METHODS: This prospective study was conducted at the Department of Ophthalmology, Faculty of Medicine, Siriraj Hospital, Thailand, between January, 2015 and December, 2016. We enlisted patients over 18 years of age with history of ON and categorized patients into 4 groups: 1) aquaporin 4 antibodies (AQP4-IgG) positive; 2) multiple sclerosis (MS); 3) myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) positive; 4) idiopathic-ON patients. Healthy controls were also included during the same study period. All patients underwent complete ophthalmological examination and spectral domain optical coherence tomography (OCT) imaging to analyze RNFL and GCIPL thickness after at least 3mo since the last episode of acute ON. The generalized estimating equation (GEE) models were used to compare the data amongst ON groups. RESULTS: Among 87 previous ON eyes from 57 patients (43 AQP4-IgG+ON, 17 MS-ON, 8 MOG-IgG+ON, and 19 idiopathic-ON), mean logMAR visual acuity of AQP4-IgG+ON, MS-ON, MOG-IgG+ON, and idiopathic-ON groups was 0.76±0.88, 0.12±0.25, 0.39±0.31, and 0.75±1.08, respectively. Average, superior, and inferior RNFL were significantly reduced in AQP4-IgG+ON, MOG-IgG+ON and idiopathic-ON eyes, relative to those of MS-ON. Differences were not statistically significant for RNFL or GCIPL between the AQP4-IgG+ON and MOG-IgG+ON groups, whereas visual acuity in MOG-IgG+ON was slightly, but not significantly, better (0.39 vs 0.76). Although RNFL thickness in MOG-IgG+ON was significantly reduced as compared to MS-ON, mean visual acuity and GCIPL were not different. CONCLUSION: Thinning of superior and inferior quadrants of RNFL are more commonly seen in MOG-IgG+ON and AQP4-IgG+ON. Long term visual acuity in MOG-IgG+ON is often better than AQP4-IgG+ON, whereas the structural change from OCT is comparable

Effective enhancement of <it>Pseudomonas stutzeri</it> D-phenylglycine aminotransferase functional expression in <it>Pichia pastoris</it> by co-expressing <it>Escherichia coli</it> GroEL-GroES

Abstract Background D-phenylglycine aminotransferase (D-PhgAT) of Pseudomonas stutzeri ST-201 catalyzes the reversible stereo-inverting transamination potentially useful in the application for synthesis of D-phenylglycine and D-4-hydroxyphenylglycine using L-glutamate as a low cost amino donor substrate in one single step. The enzyme is a relatively hydrophobic homodimeric intracellular protein difficult to express in the soluble functionally active form. Over-expression of the dpgA gene in E. coli resulted in the majority of the D-PhgAT aggregated into insoluble inclusion bodies that failed to be re-natured. Expression in Pichia pastoris was explored as an alternative route for high level production of the D-PhgAT. Results Intracellular expression of the codon-optimized synthetic dpgA gene under the PAOX1 promoter in P. pastoris resulted in inactive D-PhgAT associated with insoluble cellular fraction and very low level of D-PhgAT activity in the soluble fraction. Manipulation of culture conditions such as addition of sorbitol to induce intracellular accumulation of osmolytes, addition of benzyl alcohol to induce chaperone expression, or lowering incubation temperature to slow down protein expression and folding rates all failed to increase the active D-PhgAT yield. Co-expression of E. coli chaperonins GroEL-GroES with the D-PhgAT dramatically improved the soluble active enzyme production. Increasing gene dosage of both the dpgA and those of the chaperones further increased functional D-PhgAT yield up to 14400-fold higher than when the dpgA was expressed alone. Optimization of cultivation condition further increased D-PhgAT activity yield from the best co-expressing strain by 1.2-fold. Conclusions This is the first report on the use of bacterial chaperones co-expressions to enhance functional intracellular expression of bacterial enzyme in P. pastoris. Only two bacterial chaperone genes groEL and groES were sufficient for dramatic enhancement of functionally active D-PhgAT expression in this yeast. With the optimized gene dosage and chaperone combinations, P. pastoris can be attractive for intracellular expression of bacterial proteins since it can grow to a very high cell density which is translated into the higher volumetric product yield than the E. coli or other bacterial systems.</p

Independent saturation of three TrpRS subsites generates a partially assembled state similar to those observed in molecular simulations

Two new crystal structures of Bacillus stearothermophilus tryptophanyl-tRNA synthetase (TrpRS) afford evidence that a closed interdomain hinge angle requires a covalent bond between AMP and an occupant of either pyrophosphate or tryptophan subsite. They also are within experimental error of a cluster of structures observed in a nonequilibrium molecular dynamics simulation showing partial active-site assembly. Further, the highest energy structure in a minimum action pathway computed by using elastic network models for Open and Pretransition state (PreTS) conformations for the fully liganded TrpRS monomer is intermediate between that simulated structure and a partially disassembled structure from a nonequilibrium molecular dynamics trajectory for the unliganded PreTS. These mutual consistencies provide unexpected validation of inferences drawn from molecular simulations

Health-related quality of life of daily-life-affected benign essential blepharospasm: Multi-center observational study

Purpose To compare Thais’ health-related quality of life (HRQOL) and severity grading, efficacy and safety in daily-life-affected benign essential blepharospasm (BEB) patients at baseline and after Botulinum toxin type A (BTX-A) treatment. Design Prospective-observational study. Participants BEB patients with Jankovic rating scale (JRS) at least 3 in both severity and frequency graded from 14 institutes nationwide were included from August 2020 to June 2021. Methods Demographic data, HRQOL evaluated by the Thai version of EQ-5D-5L and NEI-VFQ-25 questionnaires, and severity grading score evaluated by Jankovic rating scale (JRS) at baseline, 1, and 3 months after the treatment were collected. The impact of the BTX-A injections and their complications were recorded. Results 184 daily-life-affected BEB patients were enrolled; 159 patients (86.4%) had complete data with a mean age of 61.40±10.09 years. About 88.05% were female, and 10.1% were newly diagnosed. Most of the patients had bilateral involvement (96.9%) and 12.6% had history of BEB-related accident. After BTX-A treatment, HRQOL improved significantly in 4 dimensions of EQ-5D-5L, except self-care. The EQ_VAS (mean±SD) was 64.54±19.27, 75.13±15.37, 73.8±15.85 (pConclusion Daily-life-affected BEB impacted HRQOL in most dimensions from both generic and visual-specific questionnaires. BTX-A treatment not only decreased disease severity, but also improved quality of life