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Functional amyloids are highly organized protein/peptide structures that inter alia promote biofilm formation in different bacteria. One such example is provided by a family of 20-45 residue-long peptides called phenol-soluble modulins (PSMs) from Staphylococcus aureus. External components such as eukaryotic host proteins, which alter self-assembly of bacterial amyloids, can affect the biofilm matrix. Here, we studied the effect of the highly prevalent human plasma protein fibrinogen (Fg) on fibrillation of PSMs. Fg inhibits or suppresses fibrillation of most PSMs tested (PSMα1, PSMβ1, and PSMβ2) except for PSMα3, whose already rapid aggregation is accelerated even further by Fg but leads to amorphous β-rich aggregates rather than fibrils. Fg also induces PSMβ2 to form amorphous aggregates and diverts PSMα1 into off-pathway oligomers which consist of both Fg and PSMα1 and cannot seed fibrillation. Peptide arrays showed that Fg bound to the N-terminus of PSMα1, while it bound to the entire length of PSMα3 (except the C terminus) and to the C-termini of PSMβ1 and PSMβ2. The latter peptides are all positively charged, while Fg is negatively charged at physiological pH. The positive charges complement Fg's net negative charge of -7.6 at pH 7.4. Fg's ability to inhibit PSM fibrillation reveals a potential host-defense mechanism to prevent bacterial biofilm growth and infections in the human body.

Chemical glycosylation of proteins is a powerful tool applied widely in biomedicine and biotechnology. However, it is a challenging undertaking and typically relies on recombinant proteins and site-specific conjugations. The scope and utility of this nature-inspired methodology would be broadened tremendously by the advent of facile, scalable techniques in glycosylation, which are currently missing. In this work, we investigated a one-pot aqueous protocol to achieve indiscriminate, surface-wide glycosylation of the surface accessible amines (lysines and/or N-terminus). We reveal that this approach afforded minimal if any change in the protein activity and recognition events in biochemical and cell culture assays, but at the same time provided a significant benefit of stabilizing proteins against aggregation and fibrillation - as demonstrated on serum proteins (albumins and immunoglobulin G, IgG), an enzyme (uricase), and proteins involved in neurodegenerative disease (α-synuclein) and diabetes (insulin). Most importantly, this highly advantageous result was achieved via a one-pot aqueous protocol performed on native proteins, bypassing the use of complex chemical methodologies and recombinant proteins.

Let A be an additive semigroup of real numbers the additive group generated by which is non-cyclic. Let $$I=(a,b)$$ be an open interval and $$\mathcal {A}=\left\{ f^\alpha :\alpha \in A\right\} $$ be an iteration semigroup of fixed point free increasing functions of I onto I such that $$\alpha

Background: Ionizing radiation plays a significant role in cancer treatment. Despite recent advances in radiotherapy approaches, the existence of irradiation-resistant cancer cells is still a noteworthy challenge. Therefore, developing novel therapeutic approaches are still warranted in order to increase the sensitivity of tumor cells to radiation. Many types of research rely on the role of mitochondria in radiation protection. Objective: Here, we aimed to target the mitochondria of monocyticleukemia (THP-1) radio-resistant cell line cells by a mitochondrial disrupting peptide, D (KLAKLAK)2, and investigate the synergistic effect of Gamma-irradiation and KLA for tumor cells inhibition in vitro. Material and Methods: In this experimental study, KLA was delivered into THP-1 cells using a Cell-Penetrating Peptide (CPP).The cells were then exposed to gamma-ray radiation both in the presence and absence of KLA conjugated with CPP. The impacts of KLA, ionizing radiation or combination of both were then evaluated on the cell proliferation and apoptosis of THP-1 cells using MTT assay and flow cytometry, respectively. Results: The MTT assay indicated the anti-proliferative effects of combined D (KLAKLAK)2 peptide with ionizing radiation on THP-1cells. Moreover, synergetic effects of KLA and ionizing radiation reduced cell viability and consequently enhanced cell apoptosis. Conclusion: Using KLA peptide in combination with ionizing irradiation increases the anticancer effects of radio-resistant THP-1 cells. Therefore, the combinational therapy of (KLAKLAK)2 and radiation is a promising strategy for cancer treatment the in future.

Background: Since the COVID-19 pandemic, several cases of cerebral venous sinus thrombosis (CVST) have been reported in SARS-CoV-2 infected individuals. This study provides a series of patients with CVST and SARS-CoV-2 infection.Methods: Consecutive patients with documented SARS-CoV-2 infection, as well as clinical and radiological characteristics of CVST, were reported from three teaching hospitals in the South West, North West, and the center of Iran from June to July 2020. We also searched the abstract archives until the end of August 2020 and gathered 28 reported cases. The diagnostic criteria for SARS-CoV-2 infection were determined according to SARS-CoV-2 detection in oropharyngeal or nasopharyngeal samples in clinically suspected patients. Demographics, main COVID-19 symptoms, confirmatory tests for SARS-CoV-2 infection diagnosis, the interval between the diagnosis of SARS-CoV-2 infection and CVST, clinical and radiological features of CVST, therapeutic strategies, CVST outcomes, rate of hemorrhagic transformation, and mortality rate were investigated.Results: Six patients (aged 31 to 62 years old) with confirmed CVST and SARS-CoV-2 infection were admitted to our centers. Four patients had no respiratory symptoms of SARS-CoV-2 infection. Five out of six patients developed the clinical manifestations of CVST and SARS-CoV-2 infection simultaneously. Three patients had known predisposing factors for CVST. Despite receiving CVST and SARS-CoV-2 infection treatments, four out of six patients passed away.Conclusions: The role of SARS-CoV-2 as a “cause” versus an “additive contributor” remains to be elucidated. Practitioners should be aware of the possibility of CVST in SARS-CoV-2 infection.

This longitudinal study was designed to evaluate the association between acute prestroke stress and the severity stroke and its outcomes including mortality, recurrence, disability and functional dependency. Patients with first-ever stroke (FES) were recruited from the Mashhad Stroke Incidence Study. Patients were asked about any acute severe prestroke stress in the two weeks prior to index stroke. Disability and functional disability were defined using modified the Rankin Scale and Barthel Index, respectively. We used logistic and ordinal regression tests to assess the association between acute prestroke stress and study outcomes. Among 624 patients with FES, 169 reported acute prestroke stress. Patients with acute prestroke stress were younger than those without stress (60.7 ± 14.4 vs. 66.2 ± 14.7; p

Let A be a set of positive reals, I be a real interval and A{fα:α∈A} be a set of functions of I into itself. We determine necessary and sufficient conditions on A, A and I for the system of Poincar...

In this paper, we propose a new field effect (FE) sensor for fast detection of glycated albumin (GA) based on thiol modified aptamer (TMA). A p-type Si/ (100 nm) SiO2 wafer was used, where the SiO2 layer acts as the gate insulator. This gate insulator is then decorated with a layer of randomly oriented ZnO nanorods, coated with 40 nm of Au to act as binding sites for the TMA. We have shown that the addition of GA significantly reduces the conductivity of the p-type Si channel, which can be used to determine the GA concentration in the test solution. The ZnO/Au/TMA/GA layer can induce negative charges in the Si channel underneath the gate insulator, which is followed by the depletion of the positively charged carriers of the Si, decreasing the conductivity. Accordingly, the charge carriers in the Si channel show a steady decline with increasing GA concentration. We have shown that this decrease in conductivity can be further tuned by varying the gate voltage. The sensor presented here can be used as a fast and reliable sensor for determination of GA.

Aggregation of the 140-residue protein ��-synuclein (��SN) is a key factor in the etiology of Parkinson's disease. Although the intensely anionic C-terminal domain (CTD) of ��SN does not form part of the amyloid core region or affect membrane binding ability, truncation or reduction of charges in the CTD promotes fibrillation through as yet unknown mechanisms. Here, we study stepwise truncated CTDs and identify a threshold region around residue 121; constructs shorter than this dramatically increase their fibrillation tendency. Remarkably, these effects persist even when as little as 10% of the truncated variant is mixed with the full-length protein. Increased fibrillation can be explained by a substantial increase in self-replication, most likely via fragmentation. Paradoxically, truncation also suppresses toxic oligomer formation, and oligomers that can be formed by chemical modification show reduced membrane affinity and cytotoxicity. These remarkable changes correlate to the loss of negative electrostatic potential in the CTD and highlight a double-edged electrostatic safety guard.

Aggregation of the 140-residue protein α-synuclein (αSN) is a key factor in the etiology of Parkinson’s disease. Although the intensely anionic C-terminal domain (CTD) of αSN does not form part of the amyloid core region or affect membrane binding ability, truncation or reduction of charges in the CTD promotes fibrillation through as yet unknown mechanisms. Here, we study stepwise truncated CTDs and identify a threshold region around residue 121; constructs shorter than this dramatically increase their fibrillation tendency. Remarkably, these effects persist even when as little as 10% of the truncated variant is mixed with the full-length protein. Increased fibrillation can be explained by a substantial increase in self-replication, most likely via fragmentation. Paradoxically, truncation also suppresses toxic oligomer formation, and oligomers that can be formed by chemical modification show reduced membrane affinity and cytotoxicity. These remarkable changes correlate to the loss of negative electrostatic potential in the CTD and highlight a double-edged electrostatic safety guard.

Let f : R + → R + be an increasing continuous function having no fixed point such that the differential d : = lim x → 0 + ⁡ f ( x ) x exists and 0 d 1 . In this paper we present practical tests to check if the Schroder equation σ ( f ( x ) ) = d σ ( x ) has a regularly varying solution on R + . To do this we associate to f a sequence { u 0 , u 1 , … } of continuous functions of [ 0 , 1 ] onto itself in such a way that the desired solution exists if and only if the iterative sequence U n : = u n ∘ u n − 1 ∘ ⋯ ∘ u 0 converges uniformly. Concerning this, we present three tests called: The Norm Test, The Root Test of Iterations, The Alternating Iterative Sequence Test.

Let f:R+→R+ be an increasing homeomorphism with no fixed point such that the derivative d:=limx→0+f(x)x exists and 0

Background: Little is known about the association between socioeconomic status and long-term stroke outcomes, particularly in low- and middle-income countries. Methods: Patients were recruited from the Mashhad Stroke Incidence Study in Iran. We identified different socioeconomic variables including the level of education, occupation, household size, and family income. Residential location according to patient’s neighbourhood was classified into less privileged area (LPA), middle privileged area and high privileged area (HPA). Using Cox regression, competing risk analysis and logistic regression models, we determined the association between socioeconomic status and 1- and 5-year stroke outcomes. Generalized linear model was used for adjusting associated variables for stroke severity. Results: Six hundred twenty-four patients with first-ever stroke were recruited in this study. Unemployment prior to stroke was associated with an increased risk of 1- and 5-year post-stroke mortality (1 year: adjusted hazard ratio [aHR] 3.3; 95% CI 1.6–7.06: p = 0.001; 5 years: aHR 2.1; 95% CI 1.2–3.6: p = 0.007). The 5-year mortality rate was higher in less educated patients (p = 0.03). Patients living in LPA compared to those living in HPAs experienced a more severe stroke at admission (aB 3.84; 95% CI 0.97–6.71, p = 0.009) and disabling stroke at 1 year follow-up (OR 6.1; 95% CI 1.3–28.4; p = 0.02). Conclusion: A comprehensive stroke strategy should also address socioeconomic disadvantages.

Creating and characterizing individual genetic variants remains limited in scale, compared to the tremendous variation both existing in nature and envisioned by genome engineers. Here we introduce retron library recombineering (RLR), a methodology for high-throughput functional screens that surpasses the scale and specificity of CRISPR-Cas methods. We use the targeted reverse-transcription activity of retrons to produce single-stranded DNA (ssDNA) in vivo, incorporating edits at >90% efficiency and enabling multiplexed applications. RLR simultaneously introduces many genomic variants, producing pooled and barcoded variant libraries addressable by targeted deep sequencing. We use RLR for pooled phenotyping of synthesized antibiotic resistance alleles, demonstrating quantitative measurement of relative growth rates. We also perform RLR using the sheared genomic DNA of an evolved bacterium, experimentally querying millions of sequences for causal variants, demonstrating that RLR is uniquely suited to utilize large pools of natural variation. Using ssDNA produced in vivo for pooled experiments presents avenues for exploring variation across the genome.

Background: Rituximab is a monoclonal antibody against CD20 antigen present on mature B lymphocytes. It is commonly used in some hematologic, rheumatologic as well as neurologic disorders, including multiple sclerosis (MS) and neuromyelitis optica (NMO). Although there are some data about the safety of rituximab in patients with MS and NMO, there are few experiences regarding its safety in the Iranian population with MS, and known complications are often related to the studies conducted on the patients in other countries or with other autoimmune diseases and malignancies that are different from the population of patients with MS in terms of the underlying disease status and the concomitant medications or previous medications used. Objectives: The aim of this study was to investigate the infusion related, short-term and delayed side effects of rituximab on patients with MS and NMO in the population of the south of Iran. Methods: This was a longitudinal study on patients with MS and neuromyelitis optica who were referred to the health centers affiliated to Shiraz University of Medical Sciences from September 2018 to February 2019 and received Rituximab. They were observed for side effects from the first infusion of the drug to at least 6 months later. A checklist prepared by the researcher was used to collect the data. Independent t-test and chi-square test were used for data analysis. The significance level was considered 0.05 in this study. Results: In this study, 37% of the patients had at least one side effect during the first infusion. The most common side effect was chills (shivering). Short-term side effects occurred in 15.5% of the patients. The most common type was skin manifestations. These side effects led to hospitalization in two patients. Delayed side effect was developed in 20.7% of the patients. The most common delayed side effect was skin manifestations. Conclusions: Overall, there was no unexpected side effect in patients under the study and the side effects developed were comparable to previous studies as well as those conducted on patients other than patients with MS and neuromyelitis optica. Side effects were often mild, with only two cases leading to hospitalization, both of which were self-limiting as well, and there were no serious life-threatening side effects, except for one case with bradycardia.

Tremendous genetic variation exists in nature, but our ability to create and characterize individual genetic variants remains far more limited in scale. Likewise, engineering proteins and phenotypes requires the introduction of synthetic variants, but design of variants outpaces experimental measurement of variant effect. Here, we optimize efficient and continuous generation of precise genomic edits in Escherichia coli, via in-vivo production of single-stranded DNA by the targeted reverse-transcription activity of retrons. Greater than 90% editing efficiency can be obtained using this method, enabling multiplexed applications. We introduce Retron Library Recombineering (RLR), a system for high-throughput screens of variants, wherein the association of introduced edits with their retron elements enables a targeted deep sequencing phenotypic output. We use RLR for pooled, quantitative phenotyping of synthesized variants, characterizing antibiotic resistance alleles. We also perform RLR using sheared genomic DNA of an evolved bacterium, experimentally querying millions of sequences for antibiotic resistance variants. In doing so, we demonstrate that RLR is uniquely suited to utilize non-designed sources of variation. Pooled experiments using ssDNA produced in vivo thus present new avenues for exploring variation, both designed and not, across the entire genome.

The ability to efficiently and dynamically change information stored in genomes would enable powerful strategies for studying cell biology and controlling cellular phenotypes. Current recombineering-mediated DNA writing platforms in bacteria are limited to specific laboratory conditions, often suffer from suboptimal editing efficiencies, and are not suitable forin situapplications. To overcome these limitations, we engineered a retroelement-mediated DNA writing system that enables efficient and precise editing of bacterial genomes without the requirement for target-specific elements or selection. We demonstrate that this DNA writing platform enables a broad range of applications, including efficient, scarless, andcis-element-independent editing of targeted microbial genomes within complex communities, the high-throughput mapping of spatial information and cellular interactions into DNA memory, and the continuous evolution of cellular traits.One Sentence SummaryHighly-efficient, dynamic, and conditional genome writers are engineered for DNA memory, genome engineering, editing microbial communities, high-resolution mapping of cellular connectomes, and modulating cellular evolution.

Objective: Few data are available on the associations between the level of pre-stroke physical activity and long-term outcomes in patients with stroke. This study is designed to assess the associations between pre-stroke physical activity and age of first-ever stroke occurrence and long-term outcomes. Methods: Six hundred twenty-four cases with first-ever stroke were recruited from the Mashhad Stroke Incidence Study a prospective population-based cohort in Iran. Data on Physical Activity Level (PAL) were collected retrospectively and were available in 395 cases. According to the PAL values, subjects were classified as inactive (PAL < 1.70) and active (PAL ≥ 1.70). Age at onset of stroke was compared between active and inactive groups. Using logistic model, we assessed association between pre-stroke physical activity and long-term (5-year) mortality, recurrence, disability, and functional dependency rates. We used multiple imputation to analyze missing data. Results: Inactive patients (PAL < 1.70) were more than 6 years younger at their age of first-ever-stroke occurrence (60.7 ± 15.5) than active patients (67.0 ± 13.2; p < 0.001). Patients with PAL< 1.7 also had a greater risk of mortality at 1 year [adjusted odds ratio (aOR) = 2.31; 95%CI: 1.14–4.67, p = 0.02] and 5 years after stroke (aOR = 1.81; 95%CI: 1.05–3.14, p = 0.03) than patients who were more physically active. Recurrence rate, disability, and functional dependency were not statistically different between two groups. Missing data analysis also showed a higher odds of death at one and 5 years for inactive patients. Conclusions: In our cohort, we observed a younger age of stroke and a higher odds of 1- and 5-year mortality among those with less physical activity. This is an important health promotion strategy to encourage people to remain physically active.

Despite recent declines in stroke mortality in high-income countries, the incidence and mortality of stroke have increased in many low- and middle-income countries. Population-based information on stroke in such countries is a research priority to address this rising trend. This study was designed to evaluate 5-year stroke mortality and its associated factors.During a 12-month period beginning from November 2006, 624 patients with first-ever stroke (FES) living in Mashhad, Iran, were recruited and followed longitudinally. Kaplan-Meier analyses were used to determine the cumulative risk of death. Prognostic variables associated with death were assessed using a Cox proportional hazard, backward logistic regression model.The 5-year cumulative risk of death was 53.8% for women and 60.5% for men (log rank = .1). The most frequent causes of death were stroke (41.2%), myocardial infarction/vascular diseases (16.4%), and pneumonia (14.2%). In multivariable Cox proportional hazard analysis, male gender (hazard ratio [HR]: 1.29, 95% confidence interval [CI]: 1.01-1.64), age (HR: 1.04, 95% CI: 1.03-1.05, per 1-year increase), National Institute of Health Stroke Scale score at admission (HR: 1.11, 95% CI: 1.09-1.12, per 1-point increase), atrial fibrillation (HR: 1.78, CI: 1.24-2.54), and education 12 years (HR: 1.61, 95% CI: 1.08-2.4) were associated with greater 5-year case fatality.Long-term case fatality following stroke in Iran is greater than that observed in many high-income countries. Targeting strategies to reduce the poor outcome following stroke, such as treating AF, is likely to reduce this disparate outcome.

Background: Little is known about the risk of recurrent stroke in low- and middle-income countries. This study was designed to identify the long-term risk of stroke recurrence and its associated factors. Methods: From November 21, 2006 for a period of 1 year, 624 patients with first-ever stroke (FES) were registered from the residents of 3 neighborhoods in Mashhad, Iran. Patients were followed up for the next 5 years after the index event for any stroke recurrence or death. We used competing risk analysis and cause-specific Cox proportional hazard models to estimate the cumulative incidence of stroke recurrence and its associated variables. Results: The cumulative incidence of stroke recurrence was 14.5% by the end of 5 years, with the largest rate during the first year after FES (5.6%). Only advanced age (adjusted hazard ratio [HR] 1.02; 95% CI 1.01–1.04) and severe stroke (National Institutes of Health Stroke Scale score >20; HR 2.23; 95% CI 1.05–4.74) were independently associated with an increased risk of 5-year recurrence. Case fatality at 30 days after first recurrent stroke was 43.2%, which was significantly greater than the case fatality at 30 days after FES of 24.7% (p = 0.001). Conclusion: A substantial number of our patients either died or had stroke recurrences during the study period. Advanced age and the severity of the index stroke significantly increased the risk of recurrence. This is an important finding for health policy makers and for designing preventive strategies in people surviving their stroke.

Let f be a fixed point free increasing homeomorphism of R + onto itself such that the limit d : = lim n → ∞ ⁡ f n + 1 ( x ) f n ( x ) exits, belongs to the interval ( 0 , 1 ) and is independent of x ∈ R + . For each α ∈ R + we define the α-bi-iterative limits f α , ∞ _ and f α , ∞ ‾ of f to be the lower and the upper limits of the sequence { f − n ( α f n ( x ) ) : n ∈ N , x ∈ R + } , respectively. We show that the following statements are equivalent: (a) The Schroder equation σ ( f ( x ) ) = d σ ( x ) has a continuous regularly varying solution. (b) The set consisting of the differentials at zero of the bi-iterative limits of f is dense in the multiplicative group R + . (c) There exists α ∈ R + such that β : = lim x → 0 + ⁡ f α , ∞ _ ( x ) / x exists, belongs to R + and log ⁡ β / log ⁡ d is irrational.