Depletion of complement factor 3 delays the neuroinflammatory response to intracortical microelectrodes.

The neuroinflammatory response to intracortical microelectrodes (IMEs) used with brain-machine interfacing (BMI) applications is regarded as the primary contributor to poor chronic performance. Recent developments in high-plex gene expression technologies have allowed for an evolution in the investigation of individual proteins or genes to be able to identify specific pathways of upregulated genes that may contribute to the neuroinflammatory response. Several key pathways that are upregulated following IME implantation are involved with the complement system. The complement system is part of the innate immune system involved in recognizing and eliminating pathogens - a significant contributor to the foreign body response against biomaterials. Specifically, we have identified Complement 3 (C3) as a gene of interest because it is the intersection of several key complement pathways. In this study, we investigated the role of C3 in the IME inflammatory response by comparing the neuroinflammatory gene expression at the microelectrode implant site between C3 knockout (C3-/-) and wild-type (WT) mice. We have found that, like in WT mice, implantation of intracortical microelectrodes in C3-/- mice yields a dramatic increase in the neuroinflammatory gene expression at all post-surgery time points investigated. However, compared to WT mice, C3 depletion showed reduced expression of many neuroinflammatory genes pre-surgery and 4 weeks post-surgery. Conversely, depletion of C3 increased the expression of many neuroinflammatory genes at 8 weeks and 16 weeks post-surgery, compared to WT mice. Our results suggest that C3 depletion may be a promising therapeutic target for acute, but not chronic, relief of the neuroinflammatory response to IME implantation. Additional compensatory targets may also be required for comprehensive long-term reduction of the neuroinflammatory response for improved intracortical microelectrode performance.

Amniotic fluid gamma-glutamyl transferase for prediction of biliary atresia in cases of non-visualisation of the fetal gallbladder: a retrospective study using a validated analytical platform and local reference range.

INTRODUCTION: The level of amniotic fluid gamma-glutamyl transferase (AFGGT) may help identify biliary atresia (BA) in cases of non-visualisation of the fetal gallbladder (NVFGB). This study aimed to validate a serum/plasma matrix-based gamma-glutamyl transferase (GGT) assay for amniotic fluid (AF) samples, establish a local gestational age-specific AFGGT reference range, and evaluate the efficacy of AFGGT for predicting fetal BA in pregnancies with NVFGB using the constructed reference range. METHODS: The analytical performance of a serum/plasma matrix-based GGT assay on AF samples was evaluated using a Cobas c502 analyser. Amniotic fluid gamma-glutamyl transferase levels in confirmed euploid singleton pregnancies (16+0 to 22+6 weeks of gestation) were determined using the same analyser to establish a local gestational age-specific reference range (the 2.5th to 97.5th percentiles). This local reference range was used to determine the positive predictive value (PPV) and negative predictive value (NPV) of AFGGT level <2.5th percentile for identifying fetal BA in euploid pregnancies with NVFGB. RESULTS: The serum/plasma matrix-based GGT assay was able to reliably and accurately determine GGT levels in AF samples. Using the constructed local gestational age-specific AFGGT reference range, the NPV and PPV of AFGGT level <2.5th percentile for predicting fetal BA in pregnancies with NVFGB were 100% and 25% (95% confidence interval=0, 53), respectively. CONCLUSION: In pregnancies with NVFGB, AFGGT level ≥2.5th percentile likely excludes fetal BA. Although AFGGT level <2.5th percentile is not diagnostic of fetal BA, fetuses with AFGGT below this level should be referred for early postnatal investigation.

Comprehensive proteomic analysis of the differential expression of 62 proteins following intracortical microelectrode implantation.

Intracortical microelectrodes (IMEs) are devices designed to be implanted into the cerebral cortex for various neuroscience and neuro-engineering applications. A critical feature of IMEs is their ability to detect neural activity from individual neurons. Currently, IMEs are limited by chronic failure, largely considered to be caused by the prolonged neuroinflammatory response to the implanted devices. Over the past few years, the characterization of the neuroinflammatory response has grown in sophistication, with the most recent advances focusing on mRNA expression following IME implantation. While gene expression studies increase our broad understanding of the relationship between IMEs and cortical tissue, advanced proteomic techniques have not been reported. Proteomic evaluation is necessary to describe the diverse changes in protein expression specific to neuroinflammation, neurodegeneration, or tissue and cellular viability, which could lead to the further development of targeted intervention strategies designed to improve IME functionality. In this study, we have characterized the expression of 62 proteins within 180 µm of the IME implant site at 4-, 8-, and 16-weeks post-implantation. We identified potential targets for immunotherapies, as well as key pathways that contribute to neuronal dieback around the IME implant.

Pharmacokinetics and Enterohepatic Circulation of 2-(Quinoline-8-carboxamido)benzoic Acid (2-QBA) in Mice.

The quinoline alkaloid 2-(quinoline-8-carboxamido)benzoic acid (2-QBA), which is isolated from Aspergillus sp. SCSIO06786, a deep sea-derived fungus, has been suggested as a therapeutic candidate for the treatment of Parkinson's disease. We developed an analytical method for 2-QBA using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) in mouse plasma, in which a protein precipitation method for the sample preparation of 2-QBA in mouse plasma was used due to its simplicity and good extraction recovery rates (80.49-97.56%). The linearity of the calibration standard sample, inter- and intraday precision and accuracy, and stability of three quality control samples were suitable based on the assessment criteria and the lower limit of quantification (LLOQ) of the 2-QBA was 1 ng/mL. A pharmacokinetic study of 2-QBA was performed in mice divided into oral (2.0, 5.0, and 15 mg/kg) and intravenous (0.5 and 1.0 mg/kg) administration groups. The absolute oral bioavailability (BA) range of 2-QBA was calculated as 68.3-83.7%. Secondary peaks were observed at approximately 4-8 h after the oral administration of 2-QBA at all doses. The elimination half-life of the orally administered 2-QBA was significantly longer than that of the intravenous 2-QBA. In addition, glucuronide metabolites of 2-QBA were identified. They were transformed into 2-QBA using the ß-glucuronidase treatment. Furthermore, the 2-QBA was readily absorbed from the jejunum to lower ileum. Taken together, the secondary peaks could be explained by the enterohepatic circulation of 2-QBA. In conclusion, the reabsorption of orally administered 2-QBA could contribute to the high oral BA of 2-QBA and could be beneficial for the efficacy of 2-QBA. Moreover, the simple and validated analytical method for 2-QBA using LC-MS/MS was applied to the pharmacokinetic study and BA assessments of 2-QBA in mice and would be helpful for subsequent pharmacokinetic studies, as well as for evaluations of the toxicokinetics and pharmacokinetic-pharmacodynamic correlation of 2-QBA to assess its potential as a drug.

Predictors of Quality of Life Decline in Patients with Oligometastases treated with Stereotactic Ablative Radiotherapy: Analysis of the Population-Based SABR-5 Phase II Trial.

AIMS: Most patients experience stable quality of life (QoL) after stereotactic ablative radiotherapy (SABR) treatment for oligometastases. However, a subset of patients experience clinically relevant declines in QoL on post-treatment follow-up. This study aimed to identify risk factors for QoL decline. MATERIALS AND METHODS: The SABR-5 trial was a population-based single-arm phase II study of SABR to up to five sites of oligometastases. Prospective QoL was measured using treatment site-specific tools at pre-treatment baseline and 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after treatment. The time to persistent QoL decline was calculated as the time from SABR to the first decline in QoL score meeting minimum clinically important difference with no improvement to baseline score on subsequent assessments. Univariable and multivariable logistic regression analyses were carried out to determine factors associated with QoL decline. RESULTS: One hundred and thirty-three patients were included with a median follow-up of 32 months (interquartile range 25-43). Thirty-five patients (26%) experienced a persistent decline in QoL. The median time until persistent QoL decline was not reached. The cumulative incidence of QoL decline at 2 and 3 years were 22% (95% confidence interval 14.0-29.6) and 40% (95% confidence interval 28.0-51.2), respectively. In multivariable analysis, disease progression (odds ratio 5.23, 95% confidence interval 1.59-17.47, P = 0.007) and adrenal metastases (odds ratio 9.70, 95% confidence interval 1.41-66.93, P = 0.021) were associated with a higher risk of QoL decline. Grade 3 or higher (odds ratio 3.88, 95% confidence interval 0.92-16.31, P = 0.064) and grade 2 or higher SABR-associated toxicity (odds ratio 2.24, 95% confidence interval 0.85-5.91, P = 0.10) were associated with an increased risk of QoL decline but did not reach statistical significance. CONCLUSIONS: Disease progression and adrenal lesion site were associated with persistent QoL decline following SABR. The development of grade 3 or higher toxicities was also associated with an increased risk, albeit not statistically significant. Further studies are needed, focusing on the QoL impact of metastasis-directed therapies.

An A-B Subunit Chimera of the E.Coli Verotoxin 1 Provides A Receptor Probe and Potential Vaccine Approach.

We have generated a chimera between the enzymatically active A subunit of the E coli derived AB5 verotoxin and a single receptor-binding B subunit. The construct was made by in frame fusion of the 3’ terminus of the A subunit gene with the 5’ end of the B subunit gene via the deletion of the intervening bases of the verotoxin operon such that the C terminus of the A subunit is continuous with the N terminus of a single B subunit. The gene product is a single fusion protein of 38kDa molecular weight, reactive with polyclonal and monoclonal antibodies against either the A or B subunits of the wild type toxin. The chimera showed a 104-105 fold reduction in cell vero cell cytotoxicity but no toxicity for the globotriaosyl ceramide (Gb3) deficient VRP subclone. No Gb3 binding by TLC overlay was detected. Polyclonal rabbit anti-VT1A-B chimera serum neutralizes VT1 cytotoxicity in vitro but reacts only with the A subunit of the wildtype holotoxin by western blot. This A-B chimera illustrates the importance of the pentameric B subunit in receptor binding and potentially identifies a novel attenuation vaccination strategy.

Increased rate of apoptosis and decreased expression of bcl-2 protein in peripheral blood lymphocytes from patients with active systemic lupus erythematosus.

Defective regulation of apoptosis may play a role in the development of autoimmune diseases, and the proto-oncogene bcl-2 is known to inhibit cells from undergoing apoptosis. We studied the rate of apoptosis with the expression of bcl-2 in peripheral blood lymphocytes of patients with systemic lupus erythematosus (SLE). A lower proportion of lymphocytes were bcl-2+ in SLE patients with active disease (median 84.9%) than in patients with inactive disease or normal (medians 95.3% and 97.1% respectively, p < 0.05). The rate of apoptosis of freshly isolated PBL was significantly higher in SLE patients than in normal (medians 1.2% vs 0.5%, p < 0.05). After 48-hour culture the apoptotic rate was further increased in SLE patients, particularly those with active disease (SLE overall 34.2%, active 62% inactive 27.5%, normal 11.25%). These findings support the theory that in SLE patients increased apoptosis may provide a source of extracellular nuclear antigens which stimulate the autoimmune response and form immune complexes with autoantibodies.

Comparison of counter immunoelectrophoresis with immunoblotting for detection of anti-extractable nuclear antigen antibodies in systemic lupus erythematosus.

Anti-extractable nuclear antigen (ENA) antibodies were assayed by counter immunoelectrophoresis (CIE) and immunoblotting in patients with systemic lupus erythematosus (SLE). We found the two methods showed good concordance rates, the lowest being 67% for anti-SS-A. Immunoblotting was more sensitive in detecting anti-Sm, anti-SS-B and anti-PCNA (proliferating cell nuclear antigen); CIE was more sensitive for anti-nRNP and anti-SS-A. Overall, the prevalence of these anti-ENA antibodies in SLE was increased by 9-20% if immunoblotting was used in addition to CIE. Sera specific for the 52 kDa peptide of the SS-A antigen (anti-52kDa SS-A) were better detected by immunoblotting. Anti-PCNA antibody was found in 6.3% of SLE patients and was associated with active disease and hemolytic anemia. The positive rate of anti-Sm was 9% by CIE and 23.7% by immunoblotting and this antibody was a specific marker for SLE using either method. It was concluded that using immunoblotting in addition to CIE, the overall sensitivity of detection of anti-ENA antibodies in SLE was increased and clinically useful antibodies such as anti-52kDa SS-A and anti-PCNA could be detected.

Peripheral blood lymphocyte subsets after allogeneic bone marrow transplantation: reconstitution and correlation with the occurrence of acute graft-versus-host disease.

Peripheral blood lymphocyte subsets were enumerated at regular intervals during the first year after allogeneic bone marrow transplantation (BMT) in 21 Chinese patients. Eight of these patients had acute graft-versus-host disease (GVHD) while they were assessed at the time of engraftment. Our results show in patients receiving allogeneic BMT: (1) T and NK cells were the predominant lymphocyte subsets in the early reconstitution stage while B cells were severely depleted; (2) absolute numbers of the major lymphocyte subsets normalised in 4-5 months; (3) an increased percentage of T cells that expressed the activation antigen HLA-DR and a reversed CD4:CD8 ratio were observed throughout the first 12 months after BMT; (4) patients with acute GVHD had significantly higher white cell count and NK cell percentage than those not complicated by acute GVHD.