SARS-CoV-2 detection by targeting four loci of viral genome using graphene oxide and gold nanoparticle DNA biosensor.

The current COVID-19 pandemic outbreak poses a serious threat to public health, demonstrating the critical need for the development of effective and reproducible detection tests. Since the RT-qPCR primers are highly specific and can only be designed based on the known sequence, mutation sensitivity is its limitation. Moreover, the mutations in the severe acute respiratory syndrome ß-coronavirus (SARS-CoV-2) genome led to new highly transmissible variants such as Delta and Omicron variants. In the case of mutation, RT-qPCR primers cannot recognize and attach to the target sequence. This research presents an accurate dual-platform DNA biosensor based on the colorimetric assay of gold nanoparticles and the surface-enhanced Raman scattering (SERS) technique. It simultaneously targets four different regions of the viral genome for detection of SARS-CoV-2 and its new variants prior to any sequencing. Hence, in the case of mutation in one of the target sequences, the other three probes could detect the SARS-CoV-2 genome. The method is based on visible biosensor color shift and a locally enhanced electromagnetic field and significantly amplified SERS signal due to the proximity of Sulfo-Cyanine 3 (Cy3) and AuNPs intensity peak at 1468 cm-1. The dual-platform DNA/GO/AuNP biosensor exhibits high sensitivity toward the viral genome with a LOD of 0.16 ng/µL. This is a safe point-of-care, naked-eye, equipment-free, and rapid (10 min) detection biosensor for diagnosing COVID-19 cases at home using a nasopharyngeal sample.

Melatonin as a complementary and prophylactic agent against COVID-19 in high-risk populations: A narrative review of recent findings from clinical and preclinical studies.

The coronavirus disease 2019 (COVID-19) pandemic has been going on around the world for more than a year and has cost a lot, as well as affected the quality of life of many. The psychological stress like delirium and sleep disturbances caused by the COVID-19 has affected many people in direct or indirect way by the disease. Insomnia and sleep deprivation have a negative effect on the immune system as well as disorders of the hormonal system, including the production and secretion of melatonin, known as the sleep hormone. Melatonin is a known anti-inflammatory and antioxidant agent in addition to its role in regulating circadian rhythms. In this review, we investigated the relationship between the effect of psychological stress caused by COVID-19 on patients, their families, health care workers, and occupations as well as how melatonin might act as a prophylactic agent with sedative effects and sleep enhancement potential. Search terms "melatonin" and "COVID-19" were manually searched on PubMed or other electronic database and relevant articles were included. Based on the review of scholarly articles, it can be inferred that melatonin, as an endogenous hormone controlling and regulating sleep and wakefulness in various researches, has a good potential due to its antioxidant and anti-inflammatory with minimal side effects. These beneficial effects highlight the impact of melatonin as an adjuvant and a potential alternative for the better management of SARS-CoV-2 infection in high-risk populations.

Lipid-based Nanoparticles for the Targeted Delivery of Anticancer Drugs: A Review.

Cancer is one of the leading causes of mortality worldwide. Although chemotherapeutic agents have been effectively designed to increase the survival rates of some patients, the designed chemotherapeutic agents necessarily deliver toxic chemotherapeutic drugs to healthy tissues, resulting in serious side effects. Cancer cells can often acquire drug resistance after repeatedly administering current chemotherapeutic agents, restricting their efficacy. Given such obstacles, investigators have attempted to distribute chemotherapeutic agents using targeted drug delivery systems (DDSs), especially nanotechnology-based DDSs. The lipid-based nanoparticles (LBNPs) are a large and complex class of substances utilized to manage various diseases, especially cancers. Liposomes seem to be the most frequently employed LBNPs, owing to their high biocompatibility, bioactivity, stability, and flexibility. Solid lipid NPs and non-structured lipid carriers have lately received a lot of interest. In addition, several reports focused on novel therapies via LBNPs to manage various forms of cancer. In the present research, the latest improvements in applying LBNPs have been shown to deliver different therapeutic agents to cancerous cells and be a quite successful candidate in cancer therapy.

Efficacy of a Low Dose of Melatonin as an Adjunctive Therapy in Hospitalized Patients with COVID-19: A Randomized, Double-blind Clinical Trial.

BACKGROUND: Melatonin has been known as an anti-inflammatory agent and immune modulator that may address progressive pathophysiology of coronavirus disease 2019 (COVID-19). AIM OF THE STUDY: To evaluate the clinical efficacy of adjuvant, use of melatonin in patients with COVID-19. METHODS: This single-center, double-blind, randomized clinical trial included 74 hospitalized patients with confirmed mild to moderate COVID-19 at Baqiyatallah Hospital in Tehran, Iran, from April 25, 2020-June 5, 2020. Patients were randomly assigned in a 1:1 ratio to receive standard of care and standard of care plus melatonin at a dose of 3 mg three times daily for 14 d. Clinical characteristics, laboratory, and radiological findings were assessed and compared between two study groups at baseline and post-intervention. Safety and clinical outcomes were followed up for four weeks. RESULTS: A total of 24 patients in the intervention group and 20 patients in the control group completed the treatment. Compared with the control group, the clinical symptoms such as cough, dyspnea, and fatigue, as well as the level of CRP and the pulmonary involvement in the intervention group had significantly improved (p <0.05). The mean time of hospital discharge of patients and return to baseline health was significantly shorter in the intervention group compared to the control group (p <0.05). No deaths and adverse events were observed in both groups. CONCLUSIONS: Adjuvant use of melatonin has a potential to improve clinical symptoms of COVID-19 patients and contribute to a faster return of patients to baseline health.

Designing a fluorescence padlock probe-based biosensor and colorimetric assay for the detection of G12D KRAS mutation.

Aim: Cell-free DNA in the plasma is known to be a potential biomarker for noninvasive diagnosis of oncogenic mutations. The authors aimed to design an optimized padlock probe-based hyperbranched rolling circle amplification biosensor to detect the KRAS G12D mutation using fluorescence and colorimetric methods. Methods: Single-factor experiments, Plackett-Burman design and response surface methodology were applied to optimize the padlock probe-based hyperbranched rolling circle amplification reaction. Results: The maximum fluorescence intensity was achieved at a padlock probe concentration of 1.5 pM and target concentration of 9 pM at 38°C ligation temperature. The proposed biosensor has a low detection limit of 60 fM of target DNA and a linear response in the concentration range of 60 fM to 0.2 pM. Conclusion: The results indicated the power of these assays to detect KRAS point mutations in liquid state reactions.

A systematic review of long non-coding RNAs with a potential role in breast cancer.

The human transcriptome contains many non-coding RNAs (ncRNAs), which play important roles in gene regulation. Long noncoding RNAs (lncRNAs) are an important class of ncRNAs with lengths between 200 and 200,000 bases. Unlike mRNA, lncRNA lacks protein-coding features, specifically, open-reading frames, and start and stop codons. LncRNAs have been reported to play a role in the pathogenesis and progression of many cancers, including breast cancer (BC), acting as tumor suppressors or oncogenes. In this review, we systematically mined the literature to identify 65 BC-related lncRNAs. We then perform an integrative bioinformatics analysis to identify 14 lncRNAs with a potential regulatory role in BC. The biological function of these 14 lncRNAs, their regulatory mechanisms, and roles in the initiation and progression of BC are discussed in this review. Additionally, we elaborate on the current and future applications of lncRNAs as diagnostic and/or therapeutic biomarkers in BC.

Application of Chromosome Conformation Capture Method for Detection MYC/TRD Chromosomal Translocation in Leukemia Cell Line.

Background: Chromosomal breakpoints are the most common cause of hereditary diseases and cancers. Today, many standard clinical methods such as cytogenetic and PCR based techniques are used which have limitation regarding detection resolution. Chromosome conformation capture is a method for detecting gene proximity and chromosomal rearrangements. Materials and Methods: In this study, SKW3 cell line was used for detecting t(8;14)(q24;q11) using a 3C-based technique. SKW3 cell line was used for 3C library preparation. For Inverse PCR, two regions were selected in upstream and downstream of the viewpoint locus on chromosome 8-MYC gene based on EcoRI restriction sites. The captured sequence with intra-chromosomal interaction between chr8-c-MYC and chr14-TRD was selected for the translocation PCR primer design. Results: The DNA fragment captured in 3C PCR showed a specific TRD sequence translocated downstream of the MYC gene. Translocation PCR demonstrated the existence of (8; 14) (q24; q11) MYC /TRD in both library and genomic DNA. Conclusion: This result demonstrated 3C- based method could be used as a useful low-cost easy operating technique in chromosomal rearrangements detection. In this study, the integration of whole genome library monitoring and PCR method was used as a high- through put method in chromosomal breakpoints detection.

Clinical characteristics and outcome of hospitalized COVID-19 patients with diabetes: A single-center, retrospective study in Iran.

AIM: To describe the epidemiological and clinical characteristics along with outcomes of hospitalized Coronavirus Disease 2019 (COVID-19) patients with and without diabetes. METHODS: This retrospective, single-center study included 595 consecutive hospitalized patients with confirmed COVID-19 at Baqiyatallah Hospital in Tehran, Iran, from February 26, 2020 to March 26, 2020. Demographic data, clinical, laboratory, and radiological findings were collected and compared between patients based on diabetes status. Complications and clinical outcomes were followed up until April 4, 2020. RESULTS: From among the 595 hospitalized patients with COVID-19, the median age was 55 years and 401 (67.4%) were male. The most common symptoms included fever (419 [70.4%]), dry cough (368 [61.8%]) and dyspnea (363 [61%]). A total of 148 patients (24.9%) had diabetes, and compared with patients without diabetes, these patients had more comorbidities (eg, hypertension [48.6% vs. 22.3%; P < 0.001]); had higher levels of white blood cell count, neutrophil count, C-reactive protein, erythrocyte sedimentation rate and blood urea nitrogen, and had a higher proportion of patchy ground-glass opacity in chest computed tomography findings (52.7% vs. 25.7%; P < 0.001). Significantly, patients with diabetes had more complications and needed more respiratory support than those without diabetes (P < 0.001). At the end of the follow-up, treatment failure and death was significantly higher in patients with diabetes compared to those without diabetes (17.8% vs. 8.7%; P = 0.003). CONCLUSION: COVID-19 patients with diabetes are at a higher risk of complications and a higher in-hospital mortality during hospitalization. Diabetes status of COVID-19 patients and frequent monitoring of glycemia would be helpful to prevent deteriorating clinical conditions.

The Effect of Lactobacillus casei Consumption in Improvement of Obsessive-Compulsive Disorder: an Animal Study.

Obsessive-compulsive disorder (OCD) is an important neuropsychiatric disorder worldwide. Common treatments of OCD include serotonergic antidepressants, which can cause potentially serious side effects. We assessed the effects of Lactobacillus casei (L. casei) Shirota consumption in an animal model of OCD. OCD-like symptoms were induced in rats by the chronic injection of the D2/D3 dopamine agonist quinpirole hydrochloride. Rats were classified into five groups of 6 rats. Four groups were injected chronically with quinpirole (0.5 mg/kg, twice weekly for 5 weeks). They were fed with L. casei Shirota (109 CF/g, daily for 4 weeks) (group 1), fluoxetine (10 mg/kg, daily for 4 weeks) (group 2), combination of L. casei Shirota and fluoxetine (group 3), and normal saline (positive control group). The last group did not receive dopamine agonist and was only injected with saline (negative control group). Expression levels of brain-derived neurotrophic factor (Bdnf), solute carrier family 6 member 4 (Slc6a4), and 5-hydroxytryptamine receptor type 2A (Htr2a) were assessed in orbitofrontal cortex tissues of all rats. Behavioral tests showed improvement of OCD signs in rats treated with L. casei Shirota, fluoxetine, and a combination of drugs. Quantitative PCR analysis showed a remarkable decrease in the expression of Bdnf and an increase in the expression of Htr2a in quinpirole-treated rats. After treatment with L. casei Shirota and fluoxetine, the expression level of Bdnf was increased remarkably, whereas Htr2a expression was decreased. The current study showed the effectiveness of L. casei Shirota in the treatment of OCD in a rat model. The beneficial effects of this probiotic are possibly exerted through the modulation of serotonin-related genes expression.

Exosome loaded alginate hydrogel promotes tissue regeneration in full-thickness skin wounds: An in vivo study.

Wound healing is known as one of the most complicated biological processes for injured skin caused by surgical, trauma, burns, or diabetic diseases, which causes a nonfunctioning mass of fibrotic tissue. Recent reports have suggested that exosomes (EXOs) secreted by this type of stem cells may contribute to their paracrine effect. In this study, the EXOs were isolated from the supernatant of cultured adipose-derived stem cells (ADSCs) via ultracentrifugation and filtration. The EXO loaded in the alginate-based hydrogel was used as a bioactive scaffold to preserve the EXO in the wound site in the animal model. The physical and biochemical properties of EXO loaded Alg hydrogel were characterized and results proved that fabricated structure was biodegradable and biocompatible. This bioactive wound dressing technique has significantly improved wound closure, collagen synthesis, and vessel formation in the wound area. Results offer a new viewpoint and a cell-free therapeutic strategy, for wound healing through the application of the composite structure of EXO encapsulated in alginate hydrogel.

Developing a DNA aptamer-based approach for biosensing cystatin-c in serum: An alternative to antibody-based methods.

Oligonucleotide aptamers are short, synthetic and single-stranded DNA or RNA molecules capable of binding to a wide range of molecules, from small molecules to large cells. Nowadays, aptamers are valuable tools in research, clinical diagnosis and treatment. Their small size and high specificity in addition to their lack of immunogenicity make them great alternatives to other diagnosing candidates such as antibodies. In this study, we have introduced a new method based on competitive Enzyme-Linked Aptamer Sorbent Assay (ELASA) using single-stranded DNA (ssDNA) aptamers to measure cystatin-c levels in serum samples. To this aim, through a Systematic Evolution of Ligands by Exponential Enrichment (SELEX) process a number of aptamers were selected from which an aptamer with a Kd (dissociation constant) value of 65.5 ±â€¯0.007 nM was chosen for further analyses. The limit of detection (LoD) was found to be 216.077 pg/ml. The results of the analytical application of this method in serum samples were comparable to those of commonly used commercial kits.

Evaluation and statistical optimization of a method for methylated cell-free fetal DNA extraction from maternal plasma.

PURPOSE: Methylated cell-free fetal DNA (cffDNA) in maternal plasma can potentially be used as a biomarker for accurate noninvasive prenatal testing (NIPT) of fetal disorders. Recovery and purification of cffDNA are key steps for downstream applications. In this study, we aimed to developed and evaluated different aspects of an optimized method and compared its efficiency with common methods used for extraction of methylated cffDNA. METHODS: Single factor experiments, Plackett-Burman (PB) design, and response surface methodology (RSM) were conducted for conventional Triton/Heat/Phenol (cTHP) method optimization. The total cell-free DNA (cfDNA) was extracted from pooled maternal plasma using the optimized method called the Triton/Heat/Phenol/Glycogen (THPG), cTHP method, a column-based kit, and a magnetic bead-based kit. In the next step, methylated cfDNA from the extracted total cfDNA was enriched using a methylated DNA immunoprecipitation (MeDIP) kit. Real-time quantitative polymerase chain reaction was performed on the RASSF1 gene and hyper region to determine the genomic equivalents per milliliter (GEq/ml) values of the methylated cfDNA and cffDNA, respectively. RESULTS: The optimum values of the significant factors affecting cfDNA extraction from 200 µl of plasma were 3% SDS, 1% Triton X-100, 0.9 µg/µl glycogen, and 0.3 M sodium acetate. The GEq/ml values of methylated cffDNA extracted using the THPG method were significantly higher than for the tested extraction methods (p < 0.001). CONCLUSIONS: Our results indicate that the THPG method is more efficient than the other tested methods for extraction of low copy number methylated cffDNA from a small volume of maternal plasma.

Ultrahigh sensitive enhanced-electrochemiluminescence detection of cancer biomarkers using silica NPs/graphene oxide: A comparative study.

The increasing progress in using nano-biomaterials for medical purposes has opened new horizons toward researchers around the globe. To investigate the presence of these nanomaterials and the impacts they might have, a comparative enhanced-electrochemiluminescence immunosensing study has been designed. The effects of utilizing graphene oxide, silica, and gold nanoparticles in cancer diagnosis were evaluated during the quantification of two major cancer biomarkers (CEA and AFP) in different approaches. In other words, first and second approaches were designed to employ nanomaterials while third and fourth approaches were developed in absence of those. Accordingly, resulted LODs experienced dramatic amplification when nano-biomaterials were included in the immunosensor modification (for AFP: 1st and 3rd approaches: 1.36fg/ml in comparison with 0.39ng/ml, and for CEA: 2nd and 4th approaches: 1.90fg/ml versus 0.46ng/ml, respectively). Correspondingly, capability of nano-biomaterials for developing highly sensitive and more efficient immunosensors was validated through selectivity, stability, reproducibility, and feasibility examinations.

Performance and Predictive Value of First Trimester Screening Markers for Down Syndrome in Iranian Pregnancies.

Objective: To investigate the performance of first trimester Down syndrome (DS) screening markers in Iranian pregnancies.Although sonographic and serum markers are currently recommended for the first trimester screening of Down syndrome, the screening performance of the markers depends on the race and ethnicity. Materials and methods: A retrospective case-control study using first trimester screening results recorded with the prenatal diagnostic multi-centers in Iran. A total of 6,384 pregnant women were examined from March 2012 to February 2017. Totally 100 Down syndrome cases and 266 matched controls were selected and the maternal characteristics, sonographic and biochemical screening data were collected. Statistical analysis was performed using logistic regression and descriptive statistics. A decision tree model was designed using the chi-squared automatic interaction detection method based on serum markers. Results: For screening of DS pregnancies, PAPP-A (cut-off 0.795 MoM) yielded the highest sensitivity (86%) and NB marker presented highest specificity (96.24%). combination of the biochemical markers PAPP-A and ß-hCG (cut-off: 1.55 MoM) showed the highest sensitivity over other combined markers. The decision-tree model based on serum markers improved (91% DR For a 5% FPR) first trimester screening performance. Conclusion: The novel decision-tree model base on serum markers revealed a better predictive value to achieve high sensitivity and specificity of first trimester Down syndrome screening in Iranian population.

Antibiotic Susceptibility Patterns of Extended Spectrum beta-lactamase and non Extended Spectrum beta-lactamase Pseudomonas aeruginosa Clinical Isolates.

BACKGROUND: Pseudomonas aeruginosa is known as an opportunistic pathogen responsible for nosocomial infections. Multidrug (MDR) resistance bacteria are considered as a worldwide issue. The current research goal to investigate the antibiotic susceptibility pattern in Extended Spectrum beta-lactamase and non Extended Spectrum beta-lactamase producing P. aeruginosa clinical isolates. METHODS: A total of 76 P.aeruginosa clinical isolates were collected from Milad hospital in Tehran, Iran, during 8 months period in 2012. P.aeruginosa clinical isolates were subjected for ESBL production by phenotypic methods. The antibiotic susceptibility patterns were identified in ESBL and non-ESBL P. aeruginosa by MIC. RESULTS: our results demonstrated that 76.3% (n =58) isolates were resistant to more than three antibiotics and classified as MDR. The majority of MDR strains were found in ESBL producer P. aeruginosa. ceftazidim as 3rd generation of cephalosporins, ciprofloxacin, Ticarcillin and aztreonam were found as a base for definition of MDR in the current research. The effectiveness antibiotics against ESBL and non-ESBL were meropenem and amikacin, respectively. CONCLUSION: based on our knowledge obtained from results, both ESBL and non-ESBL P. aeruginosa were resistant to extended antibiotics and this is a major health care problem. On the other hand, MDR strains more identified in ESBL producer P .a eruginosa. Also, carabapenem resistance observed in non-ESBL producer strains. Hence, it is recommended that the MDR strains should be following up. the prescription of ceftazidim, ciprofloxacin, Ticarcillin and aztreonam should be limited.