scholarly journals Properties of Heterologous anti-Ebola Immunoglobulin after Long Storage

2020 ◽  
Vol 20 (1) ◽  
pp. 50-59
Author(s):  
S. A. Melnikov ◽  
I. V. Borisevich ◽  
E. V. Rozhdestvensky ◽  
V. B. Pantyukhov ◽  
N. K. Chernikova ◽  
...  
Keyword(s):  
High Performance ◽  
Ebola Virus ◽  
Specific Activity ◽  
Risk Groups ◽  
Test Methods ◽  
Size Exclusion ◽  
Federal State ◽  
Central Scientific Research Institute ◽  
African Green Monkey Kidney ◽  
Republic Of The Congo

Ebola outbreak in eastern parts of the Democratic Republic of the Congo in 2018–2020 proved that the virus remains highly hazardous for humans, and the outbreak in West Africa in 2014–2016, which was the largest Ebola outbreak in history, showed that it could be imported to other continents, including Russia. In 1993 the Federal State Budgetary Institution “48th Central Scientific Research Institute” of the Russian Ministry of Defence developed a specific equine immunoglobulin for emergency prophylaxis of Ebola in risk groups. The evaluation and improvement of the product’s properties is an important area in the development of biological defence technologies.The aim of the study was to examine the properties of the equine anti-Ebola immunoglobulin which had been stored for a long time at 2–8 °C.Materials and methods: the authors studied batches of heterologous anti-Ebola immunoglobulin that had been stored for 17–22 years. The properties of the product were evaluated according to the requirements of the State Pharmacopoeia of the Russian Federation, 14th ed. (Ph. Rus. 14 ed.). The specific activity of the product was determined in a plaque reduction neutralisation test using Ebola virus and African green monkey kidney cells (GMK-AH-1(D)). Immunoglobulin molecular parameters were determined by size-exclusion high-performance liquid chromatography using the test methods described in the European Pharmacopoeia 9.6 and Ph. Rus. 14 ed.Results: the storage of anti-Ebola immunoglobulin for 17–22 years at 2–8 °C resulted in a four-fold reduction of the level of virus-neutralising antibodies against Ebola, decrease in the proportion of monomers from 98 to 74–90%, increase in the proportion of dimers and polymers, and formation of immunoglobulin molecules’ fragments. Signs of toxicity for mice were observed in one of the three product batches. Conclusions: the obtained results suggest the need to perform more studies to test the quality of antiEbola immunoglobulin batches that were stored for shorter periods of time in order to assess the stability of their initial characteristics.

Changes in plasma protein extravasation in rat skin during inflammatory challenges evaluated by microdialysis

2006 ◽  
Vol 290 (5) ◽  
pp. H2108-H2115 ◽  
Author(s):  
B. Å. Borge ◽  
V. V. Iversen ◽  
R. K. Reed
Keyword(s):  
Plasma Proteins ◽  
High Performance ◽  
Capillary Permeability ◽  
Specific Activity ◽  
Fluid Pressure ◽  
Ringer Solution ◽  
Size Exclusion ◽  
Prostaglandin E ◽  
Rat Skin ◽  
Continuous Administration

Docetaxel and prostaglandin E1 (PGE1) increase transcapillary albumin extravasation and reduce interstitial fluid pressure in the skin. In this study the microdialysate concentration (Cm) of 125I-labeled human serum albumin (125I-HSA) and different-sized endogenous plasma proteins (EPP) was compared to evaluate changes in transcapillary extravasation of plasma proteins. 125I-HSA was also used to estimate changes in the specific activity of albumin. Extravasation of 125I-HSA and EPP from plasma to interstitium in the rat skin was compared during continuous administration of docetaxel and PGE1 by using microdialysis in anesthetized rats. Also, 20 ml of Ringer solution (RS) were injected intravenously during 10 min in a separate group. Two hollow plasmapheresis fibers (3 cm, cut off 3,000 kDa), one acting as control, were placed subcutaneously on the back skin and perfused with RS (5 μl/min, 140 min, collected every 10 min). The size of the different EPP was estimated to be 73, 65, 56, 47, and 39 Å, separated by a size-exclusion high-performance liquid chromatography column and quantified by UV detection (280 nm). Docetaxel (0.5 mg/ml, n = 5) increased Cm of 125I-HSA and EPP of sizes 73, 65, 56, and 39 Å significantly ( P < 0.05) compared with control. PGE1 (20 μg/ml, n = 6) increased Cm of 125I-HSA significantly ( P < 0.05) but none of the different-sized EPP was increased compared with control. Intravenous RS (20 ml, n = 6) increased Cm of 125I-HSA and increased all the different-sized EPP significantly ( P < 0.05) compared with control. Although the microdialysis method is able to monitor qualitative changes in capillary permeability, a quantitative determination of the capillary reflection coefficient or permeability-surface area product was not possible, because steady state between plasma and dialysate was not achieved during the measurement period. The different pattern of extravasation of EPP and 125I-HSA after docetaxel, PGE1, and RS indicates increased interstitial transport rate and/or increased capillary permeability after docetaxel and RS, whereas PGE1 seems to increase transcapillary fluid flux without altering the permeability.

Application of a fractionation technique for better understanding of the removal of natural organic matter by alum coagulation

2002 ◽  
Vol 2 (5-6) ◽  
pp. 427-433 ◽  
Author(s):  
J. van Leeuwen ◽  
C. Chow ◽  
R. Fabris ◽  
N. Withers ◽  
D. Page ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
High Performance ◽  
Relative Proportion ◽  
Water Source ◽  
Size Exclusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Alum Treatment ◽  
Hydrophobic Acids

To gain an improved understanding of the types of organic compounds that are recalcitrant to water treatment, natural organic matter (NOM) isolates from two drinking water sources (Mt. Zero and Moorabool reservoirs, Victoria, Australia) were separated into fractions of distinct chemical behaviour using resins. Four fractions were obtained from each water source and were organics absorbed to: (1) XAD-8 (very hydrophobic acids, VHA); (2) DAX-4 (slightly hydrophobic acids, SHA); (3) bound to an anion exchange resin (charged organics, CHAR); and (4) not absorbed or bound to resins (neutrals, NEUT). These fractions were then tested to determine the capacity of alum to remove them from water and to correlate this with the character of each isolate. The fractions were characterised by the application of high performance size exclusion chromatography (HPSEC), bacterial regrowth potential (BRP), trihalomethane formation potential (THMFP), pyrolysis gas-chromatography mass spectrometry (Py-GC-MS) and thermochemolysis. The highest removals of dissolved organic carbon (DOC) by alum treatment were in waters spiked with the CHAR fractions while the NEUT fractions were the most recalcitrant. The number average molecular weights (Mn) of DOC of the CHAR fractions before treatment were the highest, whilst those of the NEUT fractions were the lowest. After alum treatment, the Mn of the NEUT fractions were only slightly reduced. Results from Py-GC-MS and thermochemolysis indicate that the NEUT fractions had the highest relative proportion of saccharide derived organic material. Nonetheless, the BRP of waters spiked with the NEUT fractions differed markedly, indicating that organics recalcitrant to alum treatment can vary substantially in their chemical composition and capacity to support microbial growth.

scholarly journals A novel PET tracer 18F-deoxy-thiamine: synthesis, metabolic kinetics, and evaluation on cerebral thiamine metabolism status

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Changpeng Wang ◽  
Siwei Zhang ◽  
Yuefei Zou ◽  
Hongzhao Ma ◽  
Donglang Jiang ◽  
...  
Keyword(s):  
High Performance ◽  
Specific Activity ◽  
High Accumulation ◽  
Metabolic Kinetics ◽  
Thiamine Metabolism ◽  
Pet Tracer ◽  
The Status ◽  
The Brain

Abstract Background Some neuropsychological diseases are associated with abnormal thiamine metabolism, including Korsakoff–Wernicke syndrome and Alzheimer’s disease. However, in vivo detection of the status of brain thiamine metabolism is still unavailable and needs to be developed. Methods A novel PET tracer of 18F-deoxy-thiamine was synthesized using an automated module via a two-step route. The main quality control parameters, such as specific activity and radiochemical purity, were evaluated by high-performance liquid chromatography (HPLC). Radiochemical concentration was determined by radioactivity calibrator. Metabolic kinetics and the level of 18F-deoxy-thiamine in brains of mice and marmosets were studied by micro-positron emission tomography/computed tomography (PET/CT). In vivo stability, renal excretion rate, and biodistribution of 18F-deoxy-thiamine in the mice were assayed using HPLC and γ-counter, respectively. Also, the correlation between the retention of cerebral 18F-deoxy-thiamine in 60 min after injection as represented by the area under the curve (AUC) and blood thiamine levels was investigated. Results The 18F-deoxy-thiamine was stable both in vitro and in vivo. The uptake and clearance of 18F-deoxy-thiamine were quick in the mice. It reached the max standard uptake value (SUVmax) of 4.61 ± 0.53 in the liver within 1 min, 18.67 ± 7.04 in the kidney within half a minute. The SUV dropped to 0.72 ± 0.05 and 0.77 ± 0.35 after 60 min of injection in the liver and kidney, respectively. After injection, kidney, liver, and pancreas exhibited high accumulation level of 18F-deoxy-thiamine, while brain, muscle, fat, and gonad showed low accumulation concentration, consistent with previous reports on thiamine distribution in mice. Within 90 min after injection, the level of 18F-deoxy-thiamine in the brain of C57BL/6 mice with thiamine deficiency (TD) was 1.9 times higher than that in control mice, and was 3.1 times higher in ICR mice with TD than that in control mice. The AUC of the tracer in the brain of marmosets within 60 min was 29.33 ± 5.15 and negatively correlated with blood thiamine diphosphate levels (r = − 0.985, p = 0.015). Conclusion The 18F-deoxy-thiamine meets the requirements for ideal PET tracer for in vivo detecting the status of cerebral thiamine metabolism.

scholarly journals PTSD, depression and anxiety in Ebola virus disease survivors in Beni town, Democratic Republic of the Congo

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Célestin Kaputu-Kalala-Malu ◽  
Eric Mafuta Musalu ◽  
Tim Walker ◽  
Olga Ntumba-Tshitenge ◽  
Steve Ahuka-Mundeke
Keyword(s):  
Ebola Virus ◽  
Democratic Republic ◽  
Short Term Memory ◽  
Virus Disease ◽  
Ebola Virus Disease ◽  
Depression And Anxiety ◽  
Short Term ◽  
Republic Of The Congo ◽  
Persistent Headache

Abstract Background Ebola Virus Disease (EVD) is a deadly and feared infectious disease, which can be responsible of debilitating physical and psychological sequelae in survivors including depression and anxiety disorders. Unfortunately, there are scarce data on survivor sequelae in Democratic Republic of the Congo. So this study assessed PTSD, depression and anxiety symptoms among EVD survivors enrolled in the follow-up program of the psychosocial care team of Beni town’s general hospital. Methods A cross-sectional study used consecutive sampling to recruit 144 Ebola virus disease survivors who came for follow up from October 23 to November 13; 2019. Basic socio-demographic data, presence of headache and short-term memory function were assessed. The Post-traumatic Checklist Scale and Hospital Anxiety and Depression Scale were used to assess psychological burden among participants. Descriptive statistics were used to summarized data and Pearson’s or likelihood chi-square were used to test association between psychiatric disorders and associated factors. Results The prevalence of PTSD, depression and anxiety was 24.3, 24.3 and 33.3% respectively. Being male (OR = 0.42, 95% CI: 0.16, 0.95, p = 0.049), suffering from persistent headache (OR = 2.62, 95% CI: 1.12, 6.14, p = 0.014), losing a loved one because of EVD (OR: 2.60, 95% CI: 1.11, 6.15, p = 0. 015) and being young − 18-24 years - (OR: 0. 261, 95% CI: 0. 08, 0.82, p = 0,026) were statistically associated with PTSD diagnosis. Having short-term memory impairment and suffering from persistent headache were statistically associated with depression and anxiety diagnoses (OR = 2.44, 95% CI: 1.03, 5.82, p = 0.026); (OR = 2.24, 95% CI: 1.04, 4.85, p = 0.025); (OR = 2.62, 95% CI: 1.12, 6.14, p = 0.014); (OR = 2.31, 95% CI: 1.06, 5.01, p = 0.020). Conclusion The prevalence of PTSD, depression and anxiety is high among EVD survivors. Development of specialized psychiatric services to sustain psychiatric and psychological health amongst survivors in the cultural context of the Eastern part of the DRC should be considered by the teams fighting against EVD in the DRC.

scholarly journals Periplasmic synthesis and purification of the human prolactin antagonist Δ1-11-G129R-hPRL

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Miriam F. Suzuki ◽  
Larissa A. Almeida ◽  
Stephanie A. Pomin ◽  
Felipe D. Silva ◽  
Renan P. Freire ◽  
...  
Keyword(s):  
Size Exclusion Chromatography ◽  
High Performance ◽  
Signal Sequence ◽  
Osmotic Shock ◽  
Size Exclusion ◽  
Specific Expression ◽  
E Coli ◽  
Human Prolactin ◽  
Exclusion Chromatography

AbstractThe human prolactin antagonist Δ1-11-G129R-hPRL is a 21.9 kDa recombinant protein with 188 amino acids that downregulates the proliferation of a variety of cells expressing prolactin receptors. Periplasmic expression of recombinant proteins in E. coli has been considered an option for obtaining a soluble and correctly folded protein, as an alternative to cytoplasmic production. The aim of this work was, therefore, to synthesize for the first time, the Δ1-11-G129R-hPRL antagonist, testing different activation temperatures and purifying it by classical chromatographic techniques. E. coli BL21(DE3) strain was transformed with a plasmid based on the pET25b( +) vector, DsbA signal sequence and the antagonist cDNA sequence. Different doses of IPTG were added, activating under different temperatures, and extracting the periplasmic fluid via osmotic shock. The best conditions were achieved by activating at 35 °C for 5 h using 0.4 mM IPTG, which gave a specific expression of 0.157 ± 0.015 μg/mL/A600 at a final optical density of 3.43 ± 0.13 A600. Purification was carried out by nickel-affinity chromatography followed by size-exclusion chromatography, quantification being performed via high-performance size-exclusion chromatography (HPSEC). The prolactin antagonist was characterized by SDS-PAGE, Western blotting, reversed-phase high-performance liquid chromatography (RP-HPLC) and MALDI-TOF–MS. The final product presented > 95% purity and its antagonistic effects were evaluated in vitro in view of potential clinical applications, including inhibition of the proliferation of cancer cells overexpressing the prolactin receptor and specific antidiabetic properties, taking also advantage of the fact that this antagonist was obtained in a soluble and correctly folded form and without an initial methionine.

scholarly journals (−)-Epicatechin—An Important Contributor to the Antioxidant Activity of Japanese Knotweed Rhizome Bark Extract as Determined by Antioxidant Activity-Guided Fractionation

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 133
Author(s):  
Urška Jug ◽  
Katerina Naumoska ◽  
Irena Vovk
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
High Performance ◽  
Radical Scavenging ◽  
Size Exclusion ◽  
Solvent Mixtures ◽  
Japanese Knotweed ◽  
Compound Identification ◽  
Rp Hplc ◽  
Ic50 Value

The antioxidant activities of Japanese knotweed rhizome bark extracts, prepared with eight different solvents or solvent mixtures (water, methanol, 80% methanol(aq), acetone, 70% acetone(aq), ethanol, 70% ethanol(aq), and 90% ethyl acetate(aq)), were determined using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay. Low half maximal inhibitory concentration (IC50) values (2.632–3.720 µg mL−1) for all the extracts were in the range of the IC50 value of the known antioxidant ascorbic acid at t0 (3.115 µg mL−1). Due to the highest extraction yield (~44%), 70% ethanol(aq) was selected for the preparation of the extract for further investigations. The IC50 value calculated for its antioxidant activity remained stable for at least 14 days, while the IC50 of ascorbic acid increased over time. The stability study showed that the container material was of great importance for the light-protected storage of the ascorbic acid(aq) solution in a refrigerator. Size exclusion–high-performance liquid chromatography (SEC-HPLC)–UV and reversed phase (RP)-HPLC-UV coupled with multistage mass spectrometry (MSn) were developed for fractionation of the 70% ethanol(aq) extract and for further compound identification, respectively. In the most potent antioxidant SEC fraction, determined using an on-line post-column SEC-HPLC-DPPH assay, epicatechin, resveratrol malonyl hexoside, and its in-source fragments (resveratrol and resveratrol acetyl hexoside) were tentatively identified by RP-HPLC-MSn. Moreover, epicatechin was additionally confirmed by two orthogonal methods, SEC-HPLC-UV and high-performance thin-layer chromatography (HPTLC) coupled with densitometry. Finally, the latter technique enabled the identification of (−)-epicatechin. (−)-Epicatechin demonstrated potent and stable time-dependent antioxidant activity (IC50 value ~1.5 µg mL−1) for at least 14 days.

scholarly journals Aggregate Removal Nanofiltration of Human Serum Albumin Solution Using Nanocellulose-Based Filter Paper

Biomedicines ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 209 ◽  
Author(s):  
Lulu Wu ◽  
Athanasios Mantas ◽  
Simon Gustafsson ◽  
Levon Manukyan ◽  
Albert Mihranyan
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Filter Paper ◽  
High Performance ◽  
Size Exclusion ◽  
Transmembrane Pressure ◽  
Protein Loss ◽  
Virus Removal ◽  
Model Virus

This study is dedicated to the rapid removal of protein aggregates and viruses from plasma-derived human serum albumin (HSA) product to reduce the risk of viral contamination and increase biosafety. A two-step filtration approach was implemented to first remove HSA aggregates and then achieve high model virus clearance using a nanocellulose-based filter paper of different thicknesses, i.e., 11 μm (prefilter) and 22 μm (virus filter) at pH 7.4 and room temperature. The pore size distribution of these filters was characterized by nitrogen gas sorption analysis. Dynamic light scattering (DLS) and size-exclusion high performance liquid chromatography (SE-HPLC) were performed to analyze the presence of HSA aggregates in process intermediates. The virus filter showed high clearance of a small-size model virus, i.e., log10 reduction value (LRV) > 5, when operated at 3 and 5 bar, but a distinct decrease in LRV was detected at 1 bar, i.e., LRV 2.65–3.75. The throughput of HSA was also dependent on applied transmembrane pressure as was seen by Vmax values of 110 ± 2.5 L m−2 and 63.6 ± 5.8 L m−2 at 3 bar and 5 bar, respectively. Protein loss was low, i.e., recovery > 90%. A distribution of pore sizes between 40 nm and 60 nm, which was present in the prefilter and absent in the virus filter, played a crucial part in removing the HSA aggregates and minimizing the risk of virus filter fouling. The presented results enable the application of virus removal nanofiltration of HSA in bioprocessing as an alternative to virus inactivation methods based, e.g., on heat treatment.

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