high titer
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2022 ◽  
Vol 12 ◽  
Author(s):  
Le Deng ◽  
Qipeng Huang ◽  
Jiang Wang ◽  
Kaiping Luo ◽  
Jiarong Liu ◽  
...  

Background: This study aimed to evaluate clinical features and prognosis and therapy option of patients with different risk ranks based on antibody against the M-type phospholipase-A2-receptor (PLA2Rab) level in seropositive M-type phospholipase-A2-receptor (PLA2R)-associated membranous nephropathy (MN) in a large sample size, multi-center study.Method: Based on the unvalidated cut-off value of PLA2Rab above 150 RU/ml as one of the clinical criteria for high risk of progressive kidney function loss in MN according to 2020 Kidney Disease: Improving Global Outcomes (KDIGO) draft guidelines recommendation, a total of 447 patients who received cyclophosphamide (CTX) or tacrolimus (TAC) combined with corticosteroids treatment for 12 months were divided into high titer (>150 RU/ml) group and non-high titer (20–150 RU/ml) group, which were subdivided into CTX subgroup and TAC subgroup. The overall cohort was classified into CTX group and TAC group as well. Clinical parameters levels and remission rates were recorded at 3, 6, and 12 months follow-up. PLA2Rab was tested by enzyme-linked immunosorbent assay.Results: Patients with high titer PLA2Rab were associated with more severe proteinuria and hypoalbuminemia compared to those with non-high titer antibody, accompanied by lower complete remission (CR) and total remission (TR) rates at 3, 6, and 12 months, which even took longer to remission. Similar remission rates differences between the two titer groups were observed in the CTX and TAC groups, respectively. PLA2Rab level at baseline was an independent predictive factor for CR and TR. In the high titer group, CR and TR rates in the CTX subgroup were significantly higher than those in the TAC subgroup at 12 months, although serious adverse events were more frequent in the former.Conclusion: High-risk rank patients with PLA2Rab level above 150 RU/ml have higher disease activity and worse prognosis among patients with seropositive PLA2R-associated MN, even under different immunosuppressive therapeutic models; moreover, CTX combined with corticosteroids was preferred compared to TAC plus corticosteroids, although serious adverse events were more frequent in the former. Additionally, baseline PLA2Rab level was an independent predictive factor for clinical remission.


2022 ◽  
Author(s):  
Taiwei Yang ◽  
Peiling Wu ◽  
Yang Zhang ◽  
Jifeng Yuan

Aromatic amines are widely used in the pharmaceutical industry. Here, we reported the establishment of a bacterial platform for synthesizing three types of aromatic amines, namely, tyramine, dopamine, and phenylethylamine. Firstly, we expressed aromatic amino acid decarboxylase from Enterococcus faecium (pheDC) in an Escherichia coli strain with an increased shikimate (SHK) pathway flux toward L-tyrosine or L-phenylalanine synthesis. We found that glycerol served as a better carbon source than glucose, resulting in 940 mg/L tyramine from 4% glycerol. Next, the genes of lactate dehydrogenase (ldhA), formate acetyltransferase (pflB), phosphate acetyltransferase (pta), and alcohol dehydrogenase (adhE) were deleted to mitigate the fermentation byproduct formation. The tyramine level was further increased to 1.965 g/L in shake flasks, corresponding to 2.1 times improvement compared with that of the parental strain. By using a similar strategy, we also managed to produce 703 mg/L dopamine and 555 mg/L phenethylamine. In summary, we have demonstrated that the knockout of ldhA-pflB-pta-adhE is an effective strategy in improving aromatic amine productions, and achieved the highest aromatic amine titers in E. coli under shake flasks reported to date.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
◽  
Paula M. Berguer ◽  
Matías Blaustein ◽  
Luis M. Bredeston ◽  
Patricio O. Craig ◽  
...  

AbstractThe receptor binding domain (RBD) of the Spike protein from SARS-CoV-2 is a promising candidate to develop effective COVID-19 vaccines since it can induce potent neutralizing antibodies. We have previously reported the highly efficient production of RBD in Pichia pastoris, which is structurally similar to the same protein produced in mammalian HEK-293T cells. In this work we designed an RBD multimer with the purpose of increasing its immunogenicity. We produced multimeric particles by a transpeptidation reaction between RBD expressed in P. pastoris and Lumazine Synthase from Brucella abortus (BLS), which is a highly immunogenic and very stable decameric 170 kDa protein. Such particles were used to vaccinate mice with two doses 30 days apart. When the particles ratio of RBD to BLS units was high (6–7 RBD molecules per BLS decamer in average), the humoral immune response was significantly higher than that elicited by RBD alone or by RBD-BLS particles with a lower RBD to BLS ratio (1–2 RBD molecules per BLS decamer). Remarkably, multimeric particles with a high number of RBD copies elicited a high titer of neutralizing IgGs. These results indicate that multimeric particles composed of RBD covalent coupled to BLS possess an advantageous architecture for antigen presentation to the immune system, and therefore enhancing RBD immunogenicity. Thus, multimeric RBD-BLS particles are promising candidates for a protein-based vaccine.


Viruses ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 131
Author(s):  
Peter Hodoameda ◽  
Linus Addae ◽  
Rollie J. Clem

The mechanisms involved in determining arbovirus vector competence, or the ability of an arbovirus to infect and be transmitted by an arthropod vector, are still incompletely understood. It is well known that vector competence for a particular arbovirus can vary widely among different populations of a mosquito species, which is generally attributed to genetic differences between populations. What is less understood is the considerable variability (up to several logs) that is routinely observed in the virus titer between individual mosquitoes in a single experiment, even in mosquitoes from highly inbred lines. This extreme degree of variation in the virus titer between individual mosquitoes has been largely ignored in past studies. We investigated which biological factors can affect titer variation between individual mosquitoes of a laboratory strain of Aedes aegypti, the Orlando strain, after Sindbis virus infection. Greater titer variation was observed after oral versus intrathoracic infection, suggesting that the midgut barrier contributes to titer variability. Among the other factors tested, only the length of the incubation period affected the degree of titer variability, while virus strain, mosquito strain, mosquito age, mosquito weight, amount of blood ingested, and virus concentration in the blood meal had no discernible effect. We also observed differences in culture adaptability and in the ability to orally infect mosquitoes between virus populations obtained from low and high titer mosquitoes, suggesting that founder effects may affect the virus titer in individual mosquitoes, although other explanations also remain possible.


2022 ◽  
Vol 98 (6) ◽  
pp. 657-663
Author(s):  
V. K. Ilyin ◽  
V. V. Boyarintsev ◽  
D. V. Komissarova ◽  
K. A. Toniyan ◽  
N. A. Usanova ◽  
...  

Introduction. Currently, the participation of women in space flights is increasing. In this regard, questions about the influence of space factors on the state of the female body arise inevitably. Model experiments, in particular, "dry" immersion, are most convenient for studying the influence of individual factors of space flight on the organism. The aim of this work is a comparative assessment of the state of the vaginal microbiota of 6 female volunteers before and after three-day "dry" immersion.Materials and methods. Microbial samples of all volunteers were stained according to Gram with a sequential culture study in accordance with the medical technology. The species identification of microorganisms was performed by MALDI-TOF-MS analysis using an Autoflex III time-of-flight mass spectrometer with Maldi BioTyper software.To assess changes in the state of the vaginal microflora and microflora of the cervical canal, eubiotic index was used. It reflects the number of positive states of microbiota to the number of negative ones.Results. After 3 days of "dry" immersion volunteers, who had high titer of aerobic microorganisms before isolation, had significant increase of the amount of aerobic microorganisms, while the number of lactobacilli decreased. The other group of volunteers showed activation of colonization resistance of the vaginal microflora. Volunteers, who had a significant contamination with anaerobic opportunistic microflora before isolation, had reduction of the number of all anaerobes, including lactobacilli. The eubiotic index, calculated for the cervical canal, decreased after 3 days of immersion. The data obtained indicate that after 3 days of isolation, the state of the microflora has deteriorated.


2022 ◽  
pp. 1-5
Author(s):  
Emily Molina ◽  
Lisa Christopher-Stine ◽  
Jemima Albayda

The clinical presentation of dermatomyositis (DM) is diverse, with varied phenotypes that may be correlated with specific autoantibodies. The anti-melanoma differentiation-associated gene 5 (MDA5) antibody in DM is associated with an amyopathic phenotype of DM, with several unusual cutaneous manifestation and increased risk for rapidly progressive interstitial lung disease. Initial presentation may be subtle, but early diagnosis is key to initiation of proper immunosuppressive therapy. In this report, we describe perinasal edema and erythema as a presenting complaint of anti-MDA5 DM in an otherwise healthy 40-year-old woman. The edema began shortly after heavy sun exposure and was followed by painful papules in her hands and arthritis within a few weeks. She was found to have high titer of anti-CCP and anti-MDA5, and thus was diagnosed with DM and rheumatoid arthritis overlap. A CT chest, abdomen, and pelvis showed patchy ground-glass and interstitial opacities in bilateral lower lobes consistent with mild interstitial lung disease without evidence of malignancy. Perinasal cutaneous findings and arthralgias improved with initiation of prednisone. To our knowledge, this is the first report of perinasal edema as a presenting symptom for DM and should raise suspicion for MDA-5 disease.


Pathogens ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 66
Author(s):  
Arnaud John Kombe Kombe ◽  
Jiajia Xie ◽  
Ayesha Zahid ◽  
Huan Ma ◽  
Guangtao Xu ◽  
...  

Varicella and herpes zoster are mild symptoms-associated diseases caused by varicella–zoster virus (VZV). They often cause severe complications (disseminated zoster), leading to death when diagnoses and treatment are delayed. However, most commercial VZV diagnostic tests have low sensitivity, and the most sensitive tests are unevenly available worldwide. Here, we developed and validated a highly sensitive VZV diagnostic kit based on the chemiluminescent immunoassay (CLIA) approach. VZV-glycoprotein E (gE) was used to develop a CLIA diagnostic approach for detecting VZV-specific IgA, IgG, and IgM. The kit was tested with 62 blood samples from 29 VZV-patients classified by standard ELISA into true-positive and equivocal groups and 453 blood samples from VZV-negative individuals. The diagnostic accuracy of the CLIA kit was evaluated by receiver-operating characteristic (ROC) analysis. The relationships of immunoglobulin-isotype levels between the two groups and with patient age ranges were analyzed. Overall, the developed CLIA-based diagnostic kit demonstrated the detection of VZV-specific immunoglobulin titers depending on sample dilution. From the ELISA-based true-positive patient samples, the diagnostic approach showed sensitivities of 95.2%, 95.2%, and 97.6% and specificities of 98.0%, 100%, and 98.9% for the detection of VZV-gE-specific IgA, IgG, and IgM, respectively. Combining IgM to IgG and IgA detection improved diagnostic accuracy. Comparative analyses on diagnosing patients with equivocal results displaying very low immunoglobulin titers revealed that the CLIA-based diagnostic approach is overall more sensitive than ELISA. In the presence of typical VZV symptoms, CLIA-based detection of high titer of IgM and low titer of IgA/IgG suggested the equivocal patients experienced primary VZV infection. Furthermore, while no difference in IgA/IgG level was found regarding patient age, IgM level was significantly higher in young adults. The CLIA approach-based detection kit for diagnosing VZV-gE-specific IgA, IgG, and IgM is simple, suitable for high-throughput routine analysis situations, and provides enhanced specificity compared to ELISA.


2022 ◽  
Author(s):  
Hairui Ji ◽  
Le Wang ◽  
Furong Tao ◽  
Zhipeng Yao ◽  
Xuezhi Li ◽  
...  

Abstract The biomass pretreatment strategies using organic acids facilitate lignin removal and enhance the enzymatic digestion of cellulose. However, lignin always suffers a severe and irreversible condensation. The newly generated C-C bonds dramatically affect its further upgrading. In this study, we used a recyclable hydrotrope (p-Toluenessulfonic acid, p-TsOH) to dissolve lignin under mild condition and stabilized lignin with a quenching agent (formaldehyde, FA) during extraction, achieving both value-added lignin extraction and efficient enzymatic saccharification of cellulose. Approximately 63.7% of lignin was dissolved by 80% (wt. %) p-TsOH with 1.5% FA addition at 80 o C, 30 min. The obtained lignin was characterized by FTIR spectroscopy, TGA, 2D HSQC NMR spectroscopy, and GPC. The results indicated that the extracted lignin exhibited excellent properties, such as light color, a low molecular weight (Mw, 5371 g/mol), and a narrow polydispersity (Mw/Mn, 1.63). The pretreated substrate was converted to ethanol via a quasi-simultaneous saccharification and fermentation process (Q-SSF). After fermentation of 60 h, the ethanol concentration reached 38.7±3.3 g/L which was equivalent to a theoretical ethanol yield of 82.9±2.2% based on the glucan content, while the residual glucose concentration was only 4.69±1.4 g/L. In short, this pretreatment strategy protected lignin to form new C-C linkages and improved the enzymatic saccharification of glucan for high-titer ethanol production.


2022 ◽  
Author(s):  
John S Decker ◽  
Romel Menacho-Melgar ◽  
Michael D Lynch

Across the biomanufacturing industry, innovations are needed to improve efficiency and flexibility, especially in the face of challenges such as the COVID-19 pandemic. Here we report an improved bioprocess for Q-Griffithsin, a broad-spectrum antiviral currently in clinical trials for COVID-19. Q-Griffithsin is produced at high titer in E. coli and purified to anticipated clinical grade without conventional chromatography or the need for any fixed downstream equipment. The process is thus both low-cost and highly flexible, facilitating low sales prices and agile modifications of production capacity, two key features for pandemic response. The simplicity of this process is enabled by a novel unit operation that integrates cellular autolysis, autohydrolysis of nucleic acids, and contaminant precipitation, giving essentially complete removal of host cell DNA as well as reducing host cell proteins and endotoxin by 3.6 and 2.4 log10 units, respectively. This unit operation can be performed rapidly and in the fermentation vessel, such that Q-GRFT is obtained with 100% yield and >99.9% purity immediately after fermentation and requires only a flow-through membrane chromatography step for further contaminant removal. Using this operation or variations of it may enable improved bioprocesses for a range of other high-value proteins in E. coli.


2021 ◽  
Vol 3 (4) ◽  
pp. 1-5
Author(s):  
Yuling LIANG ◽  
Yan LEI ◽  
Jiaqi XU ◽  
Liqi HUANG ◽  
Lian LIN ◽  
...  

Interstitial lung disease is often a serious complication of connective tissue disease(CTD), representing the first cause of death in CTD. However, there are few reports of SSc-RA overlap-associated interstitial pneumonia. Respiratory dysfunction as the first clinical manifestation is even rarely reported. We herein described a case of a male patient who developed significant respiratory dysfunction as the principal clinical sign for the past 6 months, plus newly developed skin thickening in bilateral upper limbs and pain and swelling of multiple joints for the past 6 weeks. Extensive immunological screening showed high titer of antinuclear antibodies(ANA), rheumatoid factor(RF), anti-cyclic peptide containing citrulline (anti-CCP),and positive anti-Scl-70 antibody. Chest high resolution computed tomography(HRCT) was performed and hence ILD was confirmed. Pulmonary function test (PFT) revealed obstructive ventilatory dysfunction rather than restrictive ventilatory dysfunction. So bronchodilation test was performed and asthma was considered. Finally, after a multidisciplinary team (MDT) discussion, the diagnosis of asthma and ILD associated with SSc-RA overlap was established. It is important to note that CTD associated pulmonary interstitial fibrosis must be considered as the differential diagnosis of any newly diagnosed interstitial pulmonary disease. In addition, if patient with dyspnea is highly suspicious of pulmonary interstitial fibrosis, bronchodilation test is still needed to exclude asthma in order to avoid misdiagnosis.


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