Search

It is shown that the results obtained (using the Kronecker product) for solving the -congruence Sylvester equation [9] were previously obtained by the LMI method for solving the modified matrix Sylvester equation [1], and both equations coincide up to the notation of matrix coefficients. It is noted that the algorithm proposed in [1] is more general than the algorithms presented in [9]. Contrary to the results of [9], the simplicity of the algorithm [1] allows one to use the mincx.m MATLAB package procedure for solving the matrix Sylvester equations, the numerical solution of which gives the accuracy 10-11 and 10-15 respectively in two specific examples. [ABSTRACT FROM AUTHOR]

Purpose: Adults with type 1 diabetes (T1D) are reported to be at higher risk for clinical eating disorders (ED) and other disordered eating behaviors (DEB) than their peers without diabetes. On the other hand, there is insufficient data on DEB in adults with type 2 diabetes (T2D). Our study aimed to investigate the prevalence of DEB in patients with T1D and T2D on intensive insulin therapy followed in our outpatient clinic., Methods: Diabetes Eating Problem Survey-Revised (DEPS-R), electronically delivered to the patients with T1D and T2D who were on an intensive insulin regimen followed up in the diabetes outpatient clinic in our center for the evaluation of DEB. A total of 120 participants, 80 patients with T1D and 40 patients with T2D, were included in the study. DEB was defined as a DEPS-R score ≥ 20 according to the answers given to the questionnaire., Results: Risk of DEB was observed in 35% of all individuals with diabetes and was higher in T2D (55% (n = 22)) than in T1D (25% (n = 20)) (p < 0.001). In patients with T1D, BMI was similar between the risk and normal groups in terms of DEB (p = 0.15), whereas in patients with T2D, BMI was significantly higher in the risk group in terms of DEB compared to the non-risk group (p < 0.001). There was a positive correlation between the risk of DEB and HbA1c and a negative correlation with the duration of diabetes in the T1D group (p < 0.05). Weight loss was an important goal for more than 50% of individuals with diabetes in both groups, more than 60% said they skipped a main meal or snack. 13.8% of those with T1D and 27.5% of those with T2D preferred being thin to having their diabetes better controlled., Conclusion: In our study, 35% of patients with diabetes were found to have a risk of DEB, with the risk being higher in the T2D group. Our results emphasize the importance of increasing awareness among physicians and patients about DEB, which is prevalent among patients with diabetes. Early detection of individuals at risk for DEB should be considered a crucial aspect of treatment., Competing Interests: Declarations. Ethics approval and consent to participate: The study protocol was approved by the local ethics committee (Approval Number: 686) and was managed by the principles of the Declaration of Helsinki. All participants provided written consent to participate in the study. Consent to participants: Consent was obtained from participants to publish their disease-related information without disclosing their identities. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

SARS-CoV-2, the virus responsible for the COVID-19 pandemic, belongs to the betacoronavirus genus. This virus has a high mutation rate, which rapidly evolves into new variants with different properties, such as increased transmissibility or immune evasion. Currently, the most prevalent global SARS-CoV-2 variant is Omicron, which is more transmissible than previous variants. Current available vaccines may be less effective against some currently existing SARS-CoV-2 variants, including the Omicron variant. The S1 subunit of the spike protein of SARS-CoV-2 has been a major target for COVID-19 vaccine development. It plays a crucial role in the virus's entry into host cells and is the primary target for neutralizing antibodies. In this study, the S1 subunit of the spike protein of SARS-CoV-2 was engineered and produced at a high level in Nicotiana benthamiana plant. The expression level of the recombinant S1 protein was greater than the 0.5-g/kg fresh weight, and the purification yield was at least ~0.3 g of pure protein/kg of plant biomass, which would make a plant-produced S1 antigen an ideal vaccine candidate for commercialization. Purified, the plant-produced SARS-CoV-2 S1 protein exhibited significantly higher binding to the SARS-CoV-2 receptor, angiotensin-converting enzyme 2 (ACE2). Moreover, we also show that recombinant S1 protein/antigen-elicited antibodies can neutralize the Delta or Omicron variants. Collectively, our results demonstrate that a plant-produced S1 antigen could be a promising vaccine candidate against SARS-CoV-2 variants including Omicron., Competing Interests: TM is named as the inventor on the patent applications covering plant-produced COVID-19 vaccine development. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Mamedov, Yuksel, Gurbuzaslan, Gulec, Mammadova, Ozdarendeli, Pavel, Yetiskin, Kaplan, Uygut and Hasanova.)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel and highly pathogenic coronavirus that caused an outbreak in Wuhan City, China, in 2019 and then spread rapidly throughout the world. Although several coronavirus disease 2019 (COVID-19) vaccines are currently available for mass immunization, they are less effective against emerging SARS-CoV-2 variants, especially the Omicron (B.1.1.529). Recently, we successfully produced receptor-binding domain (RBD) variants of the spike (S) protein of SARS-CoV-2 and an antigen cocktail in Nicotiana benthamiana , which are highly produced in plants and elicited high-titer antibodies with potent neutralizing activity against SARS-CoV-2. In this study, based on neutralization ability, we demonstrate that plant-produced RBD and cocktail-based vaccine candidates are highly effective against SARS-CoV-2, independently of its emerging variants. These data demonstrate that plant-produced RBD and cocktail-based proteins are the most promising vaccine candidates and may protect against Delta and Omicron-mediated COVID-19. This is the first report describing vaccines against SARS-CoV-2, which demonstrate significant activities against Delta and Omicron variants., Competing Interests: TM is named as the inventor of the patent applications covering plant-produced COVID-19 vaccine development. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Mamedov, Yuksel, Gurbuzaslan, Ilgin, Gulec, Mammadova, Ozdarendeli, Pavel, Yetiskin, Kaplan, Uygut and Hasanova.)

Objectives: Current guidelines recommend routine Hepatitis C virus (HCV) monitoring in people with serious mental illness. We sought to determine the rates at which doctors practising in inpatient psychiatry units monitor the HCV exposure risk and HCV infection status of their patients., Methods: Electronic medical records (EMRs) of 50 short stay and 50 long stay mental health inpatients of a regional NSW hospital were retrospectively audited to determine the rates at which doctors screened for HCV and associated risk factors. Chi-squared analysis and Fisher's exact test were performed to compare the two groups., Results: Screening rates for HCV-associated risk factors varied according to the specific risk factor explored (prior incarceration 61%; intravenous drug use 55%; and tattoos/piercings 6%). Of 30 patients identified as having at least one HCV-associated risk factor, only 27% ( n = 8) were tested for HCV during their admission, and the likelihood of testing was significantly higher in the long stay group. HCV infection status was documented for only one-third (34%) of patients., Conclusions: There is significant scope for improvement in assessing HCV status and exposure risk in this setting. Improved awareness among mental health professionals as to the higher incidence of HCV in this population could elicit more widespread monitoring.

The coronavirus disease 2019 (COVID-19) pandemic, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread to more than 222 countries and has put global public health at high risk. The world urgently needs a safe, cost-effective SARS-CoV-2 vaccine as well as therapeutic and antiviral drugs to combat COVID-19. Angiotensin-converting enzyme 2 (ACE2), as a key receptor for SARS-CoV-2 infections, has been proposed as a potential therapeutic tool in patients with COVID-19. In this study, we report a high-level production (about ∼0.75 g/kg leaf biomass) of human soluble (truncated) ACE2 in the Nicotiana benthamiana plant. After the Ni-NTA single-step, the purification yields of recombinant plant produced ACE2 protein in glycosylated and deglycosylated forms calculated as ∼0.4 and 0.5 g/kg leaf biomass, respectively. The plant produced recombinant human soluble ACE2s successfully bind to the SARS-CoV-2 spike protein. Importantly, both deglycosylated and glycosylated forms of ACE2 are stable at increased temperatures for extended periods of time and demonstrated strong anti-SARS-CoV-2 activities in vitro . The half maximal inhibitory concentration (IC50) values of glycosylated ACE2 (gACE2) and deglycosylated ACE2 (dACE2) were ∼1.0 and 8.48 μg/ml, respectively, for the pre-entry infection, when incubated with 100TCID 50 of SARS-CoV-2. Therefore, plant produced soluble ACE2s are promising cost-effective and safe candidates as a potential therapeutic tool in the treatment of patients with COVID-19., Competing Interests: TM named inventor on patent applications covering plant produced ACE2. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Mamedov, Gurbuzaslan, Yuksel, Ilgin, Mammadova, Ozkul and Hasanova.)

The COVID-19 pandemic has put global public health at high risk, rapidly spreading around the world. Although several COVID-19 vaccines are available for mass immunization, the world still urgently needs highly effective, reliable, cost-effective, and safe SARS-CoV-2 coronavirus vaccines, as well as antiviral and therapeutic drugs, to control the COVID-19 pandemic given the emerging variant strains of the virus. Recently, we successfully produced receptor-binding domain (RBD) variants in the Nicotiana benthamiana plant as promising vaccine candidates against COVID-19 and demonstrated that mice immunized with these antigens elicited a high titer of RBD-specific antibodies with potent neutralizing activity against SARS-CoV-2. In this study, we engineered the nucleocapsid (N) protein and co-expressed it with RBD of SARS-CoV-2 in Nicotiana benthamiana plant to produce an antigen cocktail. The purification yields were about 22 or 24 mg of pure protein/kg of plant biomass for N or N+RBD antigens, respectively. The purified plant produced N protein was recognized by N protein-specific monoclonal and polyclonal antibodies demonstrating specific reactivity of mAb to plant-produced N protein. In this study, for the first time, we report the co-expression of RBD with N protein to produce a cocktail antigen of SARS-CoV-2, which elicited high-titer antibodies with potent neutralizing activity against SARS-CoV-2. Thus, obtained data support that a plant-produced antigen cocktail, developed in this study, is a promising vaccine candidate against COVID-19.

The COVID-19 pandemic, caused by SARS-CoV-2, has rapidly spread to more than 222 countries and has put global public health at high risk. The world urgently needs cost-effective and safe SARS-CoV-2 vaccines, antiviral, and therapeutic drugs to control it. In this study, we engineered the receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein and produced it in the plant Nicotiana benthamiana in a glycosylated and deglycosylated form. Expression levels of both glycosylated (gRBD) and deglycosylated (dRBD) RBD were greater than 45 mg/kg fresh weight. The purification yields were 22 mg of pure protein/kg of plant biomass for gRBD and 20 mg for dRBD, which would be sufficient for commercialization of these vaccine candidates. The purified plant-produced RBD protein was recognized by an S protein-specific monoclonal antibody, demonstrating specific reactivity of the antibody to the plant-produced RBD proteins. The SARS-CoV-2 RBD showed specific binding to angiotensin converting enzyme 2 (ACE2), the SARS-CoV-2 receptor. In mice, the plant-produced RBD antigens elicited high titers of antibodies with a potent virus-neutralizing activity. To our knowledge, this is the first report demonstrating that mice immunized with plant-produced deglycosylated RBD form elicited high titer of RBD-specific antibodies with potent neutralizing activity against SARS-CoV-2 infection. Thus, obtained data support that plant-produced glycosylated and in vivo deglycosylated RBD antigens, developed in this study, are promising vaccine candidates for the prevention of COVID-19.

Background: Limited available animal and human data suggest an association between dysbiosis of gut microbiota and PCOS. We aimed to determine whether gut microbiota in lean women with PCOS shows any alterations compared to healthy women., Materials and Methods: Twenty-four lean patients with PCOS phenotype A according to the Rotterdam 2003 diagnostic criteria and 22 BMI-matched healthy women were included in this study. Anthropometric, hormonal and biochemical measurements were carried out in all participants. 16S rRNA gene V3-V4 region amplicon sequencing was performed on stool samples. Preprocessing of the raw data was performed using QIIME, and both QIIME and R packages were used for microbiome analysis., Results: Bacterial richness and diversity did not show a significant difference between patients and controls. Beta diversity was similar between the groups. However, Erysipelotrichaceae, Proteobacteria, Gammaproteobacteria, Enterobacteriaceae, Planococcaceae, Gemmules and Bacillales were significantly abundant in PCOS group according to LEfSe analysis. Clostridium cluster XVII showed increased abundance in patient group, while Clostridium sensustricto and Roseburia were decreased compared to controls. Random forest prediction analysis revealed Clostridium cluster XIVb as the most discriminative feature of patient group and Roseburia for healthy controls. Testosterone and androstenedione were negatively correlated with alpha and phylogenetic diversity., Conclusions: Our results suggest that gut microbiome of lean PCOS patients with full phenotype shows compositional alterations with similar bacterial richness and diversity compared to controls and that hyperandrogenism is associated with dysbiosis., (© 2020 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.)

Pfs48/45 is a leading antigen candidate for a transmission blocking (TB) vaccine. However, efforts to produce affordable, safe and correctly folded full-length Pfs48/45 using different protein expression systems have not produced an antigen with satisfactory TB activity. Pfs48/45 has 16 cysteines involved in disulfide bond formation, and the correct formation is critical for proper folding and induction of TB antibodies. Moreover, Pfs48⁄45 is not a glycoprotein in the native hosts, but contains potential glycosylation sites, which are aberrantly glycosylated during expression in eukaryotic systems. Here, we demonstrate for the first time that full length, Endo H in vivo enzymatic deglycosylated Pfs48/45 antigen is produced at a high level in plants and is structurally stable at elevated temperatures. Sera from mice immunized with this antigen showed strong inhibition in SMFA. Thus, Endo H in vivo enzymatic deglycosylated Pfs48/45 is a promising candidate for the development of an affordable TB vaccine, which may have the potential to save millions.

A plant expression platform with eukaryotic post-translational modification (PTM) machinery has many advantages compared to other protein expression systems. This promising technology is useful for the production of a variety of recombinant proteins including, therapeutic proteins, vaccine antigens, native additives, and industrial enzymes. However, plants lack some of the important PTMs, including furin processing, which limits this system for the production of certain mammalian complex proteins of therapeutic value. Furin is a ubiquitous proprotein convertase that is involved in the processing (activation) of a wide variety of precursor proteins, including blood coagulation factors, cell surface receptors, hormones and growth factors, viral envelope glycoproteins, etc. and plays a critical regulatory role in a wide variety of cellular events. In this study, we engineered the human furin gene for expression in plants and demonstrated the production of a functional active recombinant truncated human furin in N. benthamiana plant. We demonstrate that plant produced human furin is highly active both in vivo and in vitro and specifically cleaved the tested target proteins, Factor IX (FIX) and Protective Antigen (PA83). We also demonstrate that both, enzymatic deglycosylation and proteolytic processing of target proteins can be achieved in vivo by co-expression of deglycosylating and furin cleavage enzymes in a single cell to produce deglycosylated and furin processed target proteins. It is highly expected that this strategy will have many potential applications in pharmaceutical industry and can be used to produce safe and affordable therapeutic proteins, antibodies, and vaccines using a plant expression system., Competing Interests: The authors have declared that no competing interests exist.

A tyrosine-phosphorylated protein of 33 kDa is shown to be present in the solubilized yolk fraction of Xenopus laevis oocytes, eggs, and early embryos. The phosphoprotein is lipovitellin 2 as demonstrated by immunoprecipitation and mass spectrometry studies, and is termed pp33/LV2. Sub-cellular fractionation and immunoblotting studies demonstrate that pp33/LV2 is stably present in the Triton X-100-resistant and SDS-soluble yolk fractions during oogenesis, oocyte maturation, and early embryogenesis. From after the swimming tadpole stages (stage 39∼), however, it becomes partly soluble to Triton X-100-containing buffer and all disappear thereafter (stage 48∼49). In vitro enzyme assays with the use of the tyrosine phosphatase LAR and the tyrosine kinase Src demonstrate the reversible nature of the tyrosine phosphorylation of pp33/LV2. Microinjection studies demonstrate that the solubilized yolk fractions, but not those immunodepleted of pp33/LV2 or those pretreated with LAR, inhibit progesterone- or insulin-induced oocyte maturation. A pp33/LV2-like protein seems to present in two Xenopus subspecies, one other frog species, and two fish species, but not in other amphibian species, such as newt and salamander. These results suggest that LV2, in its tyrosine-phosphorylated form, serves in a cellular function in a species-specific manner, but the mechanism is still unknown.

Background: Studies have examined the function of PI 3-kinase in the early developmental processes that operate in oocytes or early embryos of various species. However, the roles of egg-associated PI 3-kinase and Akt, especially in signal transduction at fertilization, are not well understood., Results: Here we show that in Xenopus eggs, a potent inhibitor of phosphatidylinositol 3-kinase (PI 3-kinase), LY294002 inhibits sperm-induced activation of the tyrosine kinase Src and a transient increase in the intracellular concentration of Ca2+ at fertilization. LY294002 also inhibits sperm-induced dephosphorylation of mitogen-activated protein kinase, breakdown of cyclin B2 and Mos, and first embryonic cleavage, all of which are events of Ca2+-dependent egg activation. In fertilized eggs, an 85-kDa subunit of PI 3-kinase (p85) undergoes a transient translocation to the low-density, detergent-insoluble membranes (membrane microdomains) where Src tyrosine kinase signaling is operating. However, the tyrosine phosphorylation of p85 in fertilized eggs is not as evident as that in H2O2-activated eggs, arguing against the possibility that PI 3-kinase is activated by Src phosphorylation. Nevertheless, sperm-induced activation of PI 3-kinase has been demonstrated by the finding that Akt, a serine/threonine-specific protein kinase, is phosphorylated at threonine-308. The threonine-phosphorylated Akt also localizes to the membrane microdomains of fertilized eggs. Application of bp(V), an inhibitor of PTEN that dephosphorylates PIP3, the enzymatic product of PI 3-kinase, promotes parthenogenetic activation of Xenopus eggs. In vitro kinase assays demonstrate that PIP3 activates Src in a dose-dependent manner., Conclusions: These results suggest that PI 3-kinase is involved in sperm-induced egg activation via production of PIP3 that would act as a positive regulator of the Src signaling pathway in Xenopus fertilization.

Here we address the molecular mechanism of serum-independent survival and growth of human bladder carcinoma cell line 5637. Serum starvation promoted tyrosine phosphorylation of a 145-kDa protein and activation of the tyrosine kinase Src and the receptor for epidermal growth factor (EGFR) over a slow time course (>8 hours). The phosphorylated 145-kDa protein was identified as the beta-subunit of c-Met/hepatocyte growth factor (HGF) receptor, p145(met), in which tyrosine residues 1003, 1234, and 1235 were phosphorylated. Inhibitors of Src (PP2, SU6656) or EGFR (AG99), but not p145(met) (K252a), effectively blocked tyrosine phosphorylation of p145(met) and promoted cell death accompanied by activation of caspase-like proteases. Conditioned medium from the serum-starved 5637 cells or purified EGF readily promoted the activation of Src and EGFR, and tyrosine phosphorylation of p145(met) in normally grown 5637 cells, suggesting that autocrine signaling of EGFR ligands is responsible for signal transduction events in serum-starved cells. Consistent with this idea, a monoclonal antibody against EGFR that would interfere with the ligand binding to EGFR blocked tyrosine phosphorylation events and promoted the caspase activation and cell death in serum-free conditions. Such apoptotic cell death was also induced by pretreatment of cells with a high concentration of HGF that downregulated endogenous p145(met). Nevertheless, Cu2+ ions, competitive inhibitors for HGF-binding to p145(met), did not show any effect on cellular functions in serum-free conditions. These results suggest that the serum-independent growth of 5637 cells involves the transmembrane signaling cascade via EGFR ligand(s) (but not HGF), EGFR, Src and p145(met).