An effective pre-treatment method for eliminating interference by serum albumin for analysis of anti-rHSA antibodies.

Analysis of anti-drug antibodies (ADAs) is important for risk assessment in clinical trials. ADA detection can be very difficult in the presence of high circulating levels of drugs or target proteins. We present an effective pretreatment method for eliminating interference by endogenous albumin for analyses of recombinant human serum albumin (rHSA) ADAs. Polyethylene glycol (PEG) precipitation was used to extract albumin-ADA immune complexes from serum samples. Following acid dissociation, albumin-reactive antibodies could be detected through an electrochemiluminescence (ECL) method. Normal human serum was used to establish detectable cut points. Goat anti-human albumin was used as the positive control to evaluate the assay performance. With regard to detection of anti-HSA antibodies, pretreatment with PEG could reduce the interference from albumin in serum. We discovered that the optimized PEG precipitation and acid dissociation (PandA) method had good performance in terms of sensitivity, drug tolerance, and selectivity.

A Long Short-Term Memory Network for Plasma Diagnosis from Langmuir Probe Data.

Electrostatic probe diagnosis is the main method of plasma diagnosis. However, the traditional diagnosis theory is affected by many factors, and it is difficult to obtain accurate diagnosis results. In this study, a long short-term memory (LSTM) approach is used for plasma probe diagnosis to derive electron density (Ne) and temperature (Te) more accurately and quickly. The LSTM network uses the data collected by Langmuir probes as input to eliminate the influence of the discharge device on the diagnosis that can be applied to a variety of discharge environments and even space ionospheric diagnosis. In the high-vacuum gas discharge environment, the Langmuir probe is used to obtain current-voltage (I-V) characteristic curves under different Ne and Te. A part of the data input network is selected for training, the other part of the data is used as the test set to test the network, and the parameters are adjusted to make the network obtain better prediction results. Two indexes, namely, mean squared error (MSE) and mean absolute percentage error (MAPE), are evaluated to calculate the prediction accuracy. The results show that using LSTM to diagnose plasma can reduce the impact of probe surface contamination on the traditional diagnosis methods and can accurately diagnose the underdense plasma. In addition, compared with Te, the Ne diagnosis result output by LSTM is more accurate.

Assessment of five satellite-derived LAI datasets for GPP estimations through ecosystem models.

Ecosystem models have been widely used for obtaining gross primary productivity (GPP) estimations at multiple scales. Leaf area index (LAI) is a critical variable in these models for describing the vegetation canopy structure and predicting vegetation-atmosphere interactions. However, the uncertainties in LAI datasets and the effects of their representation on simulated GPP remain unclear, especially over complex terrain. Here, five most popular datasets, namely the Long-term Global Mapping (GLOBMAP) LAI, Global LAnd Surface Satellite (GLASS) LAI, Geoland2 version 1 (GEOV1) LAI, Global Inventory Monitoring and Modeling System (GIMMS) LAI, and Moderate Resolution Imaging Spectroradiometer (MODIS) LAI, were selected to examine the influences of LAI representation on GPP estimations at 95 eddy covariance (EC) sites. The GPP estimations from the Boreal Ecosystem Productivity Simulator (BEPS) model and the Eddy Covariance Light Use Efficiency (EC-LUE) model were evaluated against EC GPP to assess the performances of LAI datasets. Results showed that MODIS LAI had stronger linear correlations with GLASS and GEOV1 than GIMMS and GLOMAP at the study sites. The GPP estimations from GLASS LAI had a better agreement with EC GPP than those from other four LAI datasets at forest sites, while the GPP estimations from GEOVI LAI matched best with EC GPP at grass sites. Additionally, the GPP estimations from GLASS and GEOVI LAI presented better performances than the other three LAI datasets at crop sites. Besides, the results also showed that complex terrain had larger discrepancies of LAI and GPP estimations, and flat terrain presented better performances of LAI datasets in GPP estimations. Moreover, the simulated GPP from BEPS was more sensitive to LAI than those from EC - LUE, suggesting that LAI datasets can also lead to different uncertainties in GPP estimations from different model structures. Our study highlights that the satellite-derived LAI datasets can cause uncertainties in GPP estimations through ecosystem models.

A randomized controlled dose-escalation study of SSS07, a humanized rabbit anti-human TNF alpha antibody, in healthy Chinese adults.

AIMS: SSS07 is a rabbit derived humanized anti-human TNF-α antibody. This study aimed to explore the pharmacokinetics, safety, and immunogenicity of SSS07 when administrated subcutaneously in healthy adults. METHODS: This was a double-blind, dose-escalation study of SSS07 in 71 adults. Dose cohorts were set to 5 mg, 15 mg, 30 mg, 50 mg, 75 mg, and 100 mg. In each dosage group, other than 100 mg, twelve healthy participants were randomly assigned to receive a single dose of SSS07 (n = 10) or placebo (n = 2). Blood samples were taken for pharmacokinetics and immunogenicity analysis. RESULTS: No deaths, serious adverse events or drug-related withdrawals occurred in this trial. No drug limited toxicity appeared. After subcutaneous injection, SSS07 was absorbed slowly with Tmax ranging from 60 to 264 h but eliminated quickly with a short half-life ranging from 21.69 to 78.4 h (1-3 days). From 5 mg to 100 mg, dose-exposure proportionality analysis found a 90% confidence interval (CI) of ß of Cmax (1.015-1.193), AUC0-t (1.096-1.263) and AUC0-∞ (0.999-1.174) partially within the range 0.926-1.074. The plasma concentration of TNF-α decreased significantly post-dose, but a few days later, levels of TNF-α elevated rapidly and exceeded its baseline value. All participants receiving SSS07 were found to be anti-drug antibody positive during the study. CONCLUSIONS: A single-dose injection of SSS07 was safe and well-tolerated in healthy adults. Doses of SSS07 from 5 mg to 100 mg could not be regarded as nonlinear, based on dose-exposure proportionality analysis. A high incidence of anti-drug antibodies indicated strong immunogenicity, which may influence the pharmacokinetics profile and interfere with the TNF-α inhibition capability of SSS07.

Preclinical evaluation of the efficacy, pharmacokinetics and immunogenicity of JS-001, a programmed cell death protein-1 (PD-1) monoclonal antibody.

JS-001 is the first monoclonal antibody (mAb) against programmed cell death protein-1 (PD-1) approved by the China Food and Drug Administration (CFDA) into the clinical trails. To date, however, no pre-clinical pharmacological and pharmacokinetic (PK) data are available. In this study, we investigated the efficacy of JS-001 and conducted a preclinical PK study, including the monitoring of anti-drug antibodies (ADAs). We found that JS-001 specifically bound to PD-1 antigen with an EC50 of 21 nmol/L, and competently blocked the binding of PD-1 antigen to PD-L1 and PD-L2 with IC50 of 3.0 and 3.1 nmol/L, respectively. Furthermore, JS-001 displayed distinct species cross-reactivity: it could bind to the PD-1 antigen on the peripheral blood mononuclear cells (PBMCs) of humans and cynomolgus monkeys, but not to those of mice and woodchucks; the Kd values for the interaction between JS-001 and PD-1 antigens on CD8+ T cells of human and cynomolgus monkey were 2.1 nmol/L and 1.2 nmol/L, respectively. In vitro, treatment with JS-001 (0.01-10 µg/mL) dose-dependently stimulated human T cell proliferation, as well as IFN-γ and TNF-α secretion. In HBsAg-vaccinated cynomolgus monkeys, the expression of PD-1+/CD4+ and PD-1+/CD8+ was significantly elevated, intramuscular injection of JS-001 (1 and 10 mg/kg) resulted in dramatic decreases in PD-1+/CD4+ and PD-1+/CD8+ expression in a dose-dependent manner, which was supported by PD-1 receptor occupancy (RO) results. In the PK study, 18 cynomolgus monkeys treated with single, ascending doses of 1, 10, and 75 mg/kg, and another 6 cynomolgus monkeys received 10 mg/kg successive administration. The plasma clearance of JS-001 followed a linear PK profile with single administration in the 1 and 10 mg/kg groups and a non-linear PK profile in the 75 mg/kg group. In the successive 10 mg/kg administration group, no drug accumulation was observed. But the AUC from the last exposure was lower than that of the first administration, which was probably due to the production of ADAs, as demonstrated in immunogenicity study. These non-clinical data are encouraging and provide a basis for the efficacy and safety of JS-001 in clinical trials.

Genetic diversity of Chinese rabies viruses: evidence for the presence of two distinct clades in China.

There have been three major rabies epidemics in China since the 1950s. To gain more insights into the molecular epidemiology of rabies viruses (RVs) for the third (the current) epidemic, we isolated RV from dogs and humans in major endemic areas, and characterized these isolates genetically by sequencing the entire glycoprotein (G) gene and the G-L non-coding region. These sequences were also compared phylogenetically with RVs isolated in China during previous epidemics and those around the world. Comparison of the entire G genes among the Chinese isolates revealed up to 21.8% divergence at the nucleotide level and 17.8% at the amino acid level. The available Chinese isolates could be divided into two distinct clades, each of which could be further divided into six lineages. Viruses in clade I include most of the Chinese viruses as well as viruses from southeast Asian countries including Indonesia, Malaysia, the Philippines, Thailand, and Vietnam. The viruses in the other clade were found infrequently in China, but are closely related to viruses distributed worldwide among terrestrial animals. Interestingly, most of the viruses isolated during the past 10 years belong to lineage A viruses within clade I whereas most of the viruses isolated before 1996 belong to other lineages within clades I and II. Our results indicated that lineages A viruses have been predominant during the past 10 years and thus are largely responsible for the third and the current epidemic in China. Our results also suggested that the Chinese RV isolates in clade I share a common recent ancestor with those circulating in southeast Asia.

[Activity of separase and its regulation].

Sister chromatids separation is under precise regulation during cell cycle. Any turbulence happened in the separation process can cause instability in the transmission of inherited material, and may cause: death or disease of cell or even individual. In eukaryotic cells, one conserved mechanism governs the separation of sister chromatids. Cohesion between sister chromatids is established during DNA replication and depends on a multiprotein complex called cohesin. At the metaphase to anaphase transition, separase is activated by proteolysis of securin. Separase can cleave one of cohesin's subunits, and then promote cohesin dissociation and sister chromatids separation.