Optimizing scan time and bayesian penalized likelihood reconstruction algorithm in copper-64 PET/CT imaging: a phantom study.

Objectives: The aim of this study was to evaluate Cu-64 PET phantom image quality using Bayesian Penalized Likelihood (BPL) and Ordered Subset Expectation Maximum with point-spread function modeling (OSEM-PSF) reconstruction algorithms. In the BPL, the regularization parameterßwas varied to identify the optimum value for image quality. In the OSEM-PSF, the effect of acquisition time was evaluated to assess the feasibility of shortened scan duration.Methods: A NEMA IEC PET body phantom was filled with known activities of water soluble Cu-64. The phantom was imaged on a PET/CT scanner and was reconstructed using BPL and OSEM-PSF algorithms. For the BPL reconstruction, variousßvalues (150, 250, 350, 450, and 550) were evaluated. For the OSEM-PSF algorithm, reconstructions were performed using list-mode data intervals ranging from 7.5 to 240 s. Image quality was assessed by evaluating the signal to noise ratio (SNR), contrast to noise ratio (CNR), and background variability (BV).Results: The SNR and CNR were higher in images reconstructed with BPL compared to OSEM-PSF. Both the SNR and CNR increased with increasingß, peaking atß= 550. The CNR for allß, sphere sizes and tumor-to-background ratios (TBRs) satisfied the Rose criterion for image detectability (CNR > 5). BPL reconstructed images withß= 550 demonstrated the highest improvement in image quality. For OSEM-PSF reconstructed images with list-mode data duration ≥ 120 s, the noise level and CNR were not significantly different from the baseline 240 s list-mode data duration.Conclusions: BPL reconstruction improved Cu-64 PET phantom image quality by increasing SNR and CNR relative to OSEM-PSF reconstruction. Additionally, this study demonstrated scan time can be reduced from 240 to 120 s when using OSEM-PSF reconstruction while maintaining similar image quality. This study provides baseline data that may guide future studies aimed to improve clinical Cu-64 imaging.

Epidemiology of Bloodstream Infections and Antimicrobial Susceptibility Pattern in ICU and Non-ICU Wards: A Four-Year Retrospective Study in Isfahan, Iran.

Background: Bloodstream infections (BSIs) are one of the causes of morbidity and mortality in hospitalised patients. This study evaluated BSI's incidence, trend, antimicrobial susceptibility patterns and mortality in AL Zahra Hospital in Isfahan, Iran. Materials and Methods: This retrospective study was conducted in AL Zahra Hospital from March 2017 to March 2021. The Iranian nosocomial infection surveillance system was used for data gathering. The data included demographic and hospital data, type of bacteria, and antibiotic susceptibility findings and were analysed in SPSS-18 software. Results: The incidence of BSIs was 1.67% and 0.47%, and the mortality was 30% and 15.2% in the intensive care unit (ICU) and non-ICU wards, respectively. In the ICU, the mortality was correlated with the use of the catheter, type of organism and year of study, but in non-ICU, correlated with age, gender, use of the catheter, ward, year of study and duration between the incidence of BSIs and discharging/death. Staphylococcus epidermidis, Acinetobacter spp. and Klebsiella spp. were the most frequent germs isolated in all wards. Vancomycin (63.6%) and Gentamycin (37.7%) for ICU and Vancomycin (55.6%) and Meropenem (53.3) for other wards were the most sensitive antibiotics. Conclusion: Despite the few rate of BSI in the last four years in AL Zahra Hospital, our data showed that its incidence and mortality in the ICU ward are significantly more than in other hospital wards. We recommend prospective multicentre studies to know the total incidence of BSI, local risk factors and patterns of pathogens causing BSI.

Designing novel peptides for detecting the Omicron variant, specifying SARS-CoV-2, and simultaneously screening coronavirus infections.

In this study in silico a candidate diagnostic peptide-based tool was designed in four stages including diagnosis of coronavirus diseases, simultaneously identifying of COVID-19 and SARS from other members of this family, specific identification of SARS-CoV2, and diagnosis of COVID-19 Omicron. Designed candidate peptides consist of four immunodominant peptides from the proteins of the SARS-CoV-2 spike (S) and membrane (M). The tertiary structure of each peptide was predicted. The stimulation ability of the humoral immunity for each peptide was evaluated. Finally, in silico cloning was performed to develop an expression strategy for each peptide. These four peptides have suitable immunogenicity, appropriate construct, and the ability to be expressed in E.coli. These results must be experimentally validated in vitro and in vivo to ensure the immunogenicity of the kit.Communicated by Ramaswamy H. Sarma.

Designing a novel multiepitope peptide vaccine against melanoma using immunoinformatics approach.

Malignant melanoma is the most aggressive and life-threaten skin cancer. Nowadays, the prevention and treatment of melanoma are challenging areas for researchers and physicians. Therefore, we implemented an in silico-based approach to design a multi-epitope peptide vaccine for melanoma. This approach consists of immunoinformatics, molecular docking, and dynamic stimulation assessments to identify potent targets. Three most immunogenic melanoma proteins; NEYSO-1, gp-100, and MART-1were considered to predict immunodominant B and T cell epitopes. The prioritized epitopes had significant potential to induce strong humoral and cellular immunity and INF-γ responses without the possibility of allergenicity. To enhance the immunogenic properties of the vaccine, we used adjuvants HBHA, the helper epitope of PADRE, and three segments of the helper epitope from TTFrC. To design the final vaccine construct, appropriate linkers are used to join immunogenicscreened-epitopes and also the adjuvants. The physicochemical and immunological properties of the vaccine were evaluated.The designed-vaccine construct was docked to TLR4 to visualize the complex affinity and then conformational dynamics simulation was used to analyze time-dependent interaction behavior. In silico cloning demonstrated that the vaccine can be efficiently expressed in E.coli. Therefore, the designed vaccine might have the ability to induce humoral and cellular immune responses against melanoma cancer antigens. This vaccine has a high-quality structure and suitable characteristics such as high stability, solubility, and a high potential for expression in a prokaryotic system. However, these results need the experimental study to ensure the immunogenicity and safety profile of the melanoma candidate vaccine construct.

Design an Efficient Multi-Epitope Peptide Vaccine Candidate Against SARS-CoV-2: An in silico Analysis.

BACKGROUND: To date, no specific vaccine or drug has been proven to be effective against SARS-CoV-2 infection. Therefore, we implemented an immunoinformatic approach to design an efficient multi-epitopes vaccine against SARS-CoV-2. RESULTS: The designed-vaccine construct consists of several immunodominant epitopes from structural proteins of spike, nucleocapsid, membrane, and envelope. These peptides promote cellular and humoral immunity and interferon-gamma responses. Also, these epitopes have a high antigenic capacity and are not likely to cause allergies. To enhance the vaccine immunogenicity, we used three potent adjuvants: Flagellin of Salmonella enterica subsp. enterica serovar Dublin, a driven peptide from high mobility group box 1 as HP-91, and human beta-defensin 3 protein. The physicochemical and immunological properties of the vaccine structure were evaluated. The tertiary structure of the vaccine protein was predicted and refined by Phyre2 and Galaxi refine and validated using RAMPAGE and ERRAT. Results of ElliPro showed 246 sresidues from vaccine might be conformational B-cell epitopes. Docking of the vaccine with toll-like receptors (TLR) 3, 5, 8, and angiotensin-converting enzyme 2 approved an appropriate interaction between the vaccine and receptors. Prediction of mRNA secondary structure and in silico cloning demonstrated that the vaccine can be efficiently expressed in Escherichia coli. CONCLUSION: Our results demonstrated that the multi-epitope vaccine might be potentially antigenic and induce humoral and cellular immune responses against SARS-CoV-2. This vaccine can interact appropriately with the TLR3, 5, and 8. Also, it has a high-quality structure and suitable characteristics such as high stability and potential for expression in Escherichia coli .

Inflammatory and T Helper 17/ Regulatory T Cells Related Cytokines Balance in Cutaneous Lupus Erythematosus (CLE).

The cutaneous lupus erythematosus (CLE) is a common manifestation among systemic lupus erythematosus (SLE) patients. Malar rash and discoid lupus (DLE) are in the category of acute and chronic CLE, respectively. The pathogenesis of CLE is multifactorial, and cytokine imbalances contribute to immune dysfunction and the induction of organ damage. Many aspects of cytokine dysregulation are still unclear in SLE and in particular CLE. Therefore, we concurrently measured the inflammatory [Tumor necrosis factor-alpha (TNF-α) and Interleukin (IL)-6)], T helper (Th)-17 (IL-17 and IL-23) and regulatory T cells [Transforming growth factor-beta (TGFß) and IL-10)]-related cytokines in patients with CLE (patients with malar rash and/or DLE) and compared them with SLE patients and healthy individuals (n=25 in each group, a total of 75 patients). The serum levels of cytokines were assessed by Enzyme-Linked Immunosorbent Assay (ELISA) method. IL-6 cytokine was significantly higher in SLE, DLE, and malar rash patients compared to those in healthy controls (p=0.025) and in patients with arthralgia (p=0.038), and gastrointestinal involvement (p=0.048). IL-17 was significantly higher in malar rash patients compared to normal individuals (p=0.023), SLE (p=0.008) and DLE patients (p=0.019) and in patients with oropharyngeal ulcer (p=0.05) but, IL-23 was significantly higher only in DLE patients than healthy controls (p=0.019). In conclusion, inflammatory cytokines such as IL-6 involved in inflammation and differentiation of Th17 cells are probably responsible in part for Th17 activity in CLE. IL-17, IL-23, and IL-6/IL-6R (IL-6 receptor) inhibitors may be good treatments for CLE patients. So targeting these cytokines activity pathways can improve the CLE treatment strategy and may open a novel guideline for SLE and CLE treatment.

Interleukin-27 gene variant rs153109 is associated with enhanced cytokine serum levels and susceptibility to Behçet's disease in the Iranian population.

Behcet's disease (BD) is a systemic vasculitis, characterized by recurrent oral aphthous, genital ulcers, ocular lesions, and other organ involvement. Interleukin (IL)-27 with its pro- and anti-inflammatory effects might be an important effective cytokine in this disease. The aim of this study was to investigate the association of IL-27 serum concentration and a single-nucleotide polymorphism (SNP) rs153109 (-964 A > G) with the risk and clinical features of the patients with BD. IL-27 Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the IL-27 serum levels were measured using enzyme-linked immunosorbent assay (ELISA). It is shown that AG, GG, and AG + GG genotypes, as well as G allele of rs153109, can significantly increase the risk of BD in total and in male individuals. Significantly higher frequencies of AG and GG genotypes and G allele were observed in total and male patients with an active form of BD. AG and GG genotypes were associated with joint (p = 0.046) and vascular (p = 0.02) involvement. The frequency of the G allele was higher in all patients, as well as in female patients with vascular involvement (p = 0.02). Serum cytokine analysis indicated an increased level of IL-27 in BD patients compared to healthy subjects (p = 0.038). Additionally, a higher level of IL-27 was detected in patients carrying the rs153109 GG genotype (p = 0.04) and those with renal (p = 0.009) and skin (p = 0.05) involvement. In conclusion, this study underscores the involvement of IL-27 rs153109 variants and increased serum level in BD susceptibility and pathogenesis.

Predominant role of innate pro-inflammatory cytokines in vitiligo disease.

Vitiligo is a skin disorder with melanocyte destruction and an autoimmune basis. Given the importance of cytokines in autoimmunity, we aimed to find the cytokine profile of innate and adaptive immunity in vitiligo patients, and correlate them with clinical parameters. The serum levels of innate immunity [interleukin(IL)-1α, IL-1ß, IL-6, IL-8, IL-12, IL-15 and tumor necrosis factor (TNF)-α] and T helper(Th)1 [IL-2, interferon (IFN)-γ, TNF-ß], Th2 (IL-4, IL-5, IL-10, IL-13) and Th17 (IL-17, IL-23) cytokines in 44 vitiligo patients were measured by multiplex cytokine assay and compared with 44 healthy subjects. All innate immunity (p < 0.04), Th1 (p < 0.01), Th2 (p < 0.05) and Th17 (p < 0.001) cytokines were higher in patients than controls. Total summation levels of innate immunity and adaptive immunity cytokines showed a remarkable up-regulation in the patients (p < 0.0001). The ratio of innate immunity to Th1 (p = 0.03), Th2 (p = 0.01) and Th17 (p = 0.03) cytokines was significantly higher in patients vs. controls. We found significant higher ratio of Th1 to Th2 cytokines and TNF-ß elevated levels in patients with a family history of autoimmunity (p < 0.05). IL-4 and IL-13 (p < 0.04) levels were lower in patients with amelanotic hair. Increased IL-10 level was observed in patients with stable disease (p = 0.02).In conclusion, the profile of cytokines in patients showed a dominant role of innate immunity pro-inflammatory cytokines in vitiligo, which suggests the potential of targeting these cytokines for vitiligo treatment. While a higher ratio of Th1/Th2 cytokines was observed in the patients, association of decreased Th2 cytokines with disease complications suggests a protective role for Th2 pathway.

Prevalence of herpes simplex virus-1 in hospitalized adult patients with clinical diagnosis of meningoencephalitis using real-time polymerase chain reaction: A single-center, cross-sectional study.

BACKGROUND: Early diagnosis of herpes simplex virus-1 (HSV-1) meningoencephalitis is very important because antiviral therapy significantly decreases mortality and morbidity. Polymerase chain reaction (PCR) is a reliable method with high sensitivity and specificity in detection of HSV-1. The aim of this study is to determine the prevalence of HSV-1 in patients with diagnosis of meningoencephalitis using real-time PCR. MATERIALS AND METHODS: The cerebrospinal fluid samples were collected from 126 patients with clinical diagnosis of HSV-1 meningoencephalitis in Alzahra Referral Hospital in Isfahan, Iran. After deoxyribonucleic acid (DNA) extraction, real-time PCR was performed by fluorescence resonance energy transfer assay and participants underwent brain magnetic resonance imaging, as well. RESULTS: Among 126 patients, 68.3% were male and 31.7% were female. The mean age of the participants was 41.96 ± 22.36 years. Most of the participants were in the age group of 20-29 years. Three patients (2.4%) had positive and 123 patients (97.6%) had negative HSV-1 DNA test. Among three positive cases, two were in the age group of 20-29 years and one in the age group of ≥80 years. No HSV-2 DNA was detected. CONCLUSION: According to the estimated prevalence of HSV-1 meningoencephalitis in the current study, it seems that the prevalence of HSV-1 meningoencephalitis is not too high in our community; therefore, initial empiric acyclovir therapy is frequently overused.

Pseudomonas aeruginosa-producing Metallo-ß-lactamases (VIM, IMP, SME, and AIM) in the Clinical Isolates of Intensive Care Units, a University Hospital in Isfahan, Iran.

BACKGROUND: Pseudomonas aeruginosa is a severe challenge for antimicrobial therapy, due to the chromosomal mutations or exhibition of intrinsic resistance to various antimicrobial agents such as most ß-lactams. We undertook this study to evaluate the existence of SME, IMP, AIM, and VIM metallo-ß-lactamases (MBL) encoding genes among P. aeruginosa strains isolated from Intensive Care Unit (ICU) patients in Al-Zahra Hospital in Isfahan, Iran. MATERIALS AND METHODS: In a retrospective cross-sectional study that was conducted between March 2012 and April 2013, a total of 48 strains of P. aeruginosa were collected from clinical specimens of bedridden patients in ICU wards. Susceptibility test was performed by disc diffusion method. All of the meropenem-resistant strains were subjected to modified Hodge test for detection of carbapenemases. Multiplex polymerase chain reaction was performed for detection of blaVIM, blaIMP, blaAIM, and blaSME genes. RESULTS: In disk diffusion method, imipenem and meropenem showed the most and colistin the least resistant antimicrobial agents against P. aeruginosa strains. Of the 48 isolates, 36 (75%) were multidrug resistant (MDR). Amplification of ß-lactamase genes showed the presence of blaVIM genes in 7 (%14.6) strains and blaIMP genes in 15 (31.3%) strains. All of the isolates were negative for blaSME and blaAIM genes. We could not find any statistically significant difference among the presence of this gene and MDR positive, age, or source of the specimen. CONCLUSION: As patients with infections caused by MBL-producing bacteria are at an intensified risk of treatment failure, fast determination of these organisms is necessary. Our findings may provide useful insights in replace of the appropriate antibiotics and may also prevent MBLs mediated resistance problem.

Resting and Activated Natural Tregs Decrease in the Peripheral Blood of Patients with Atherosclerosis.

BACKGROUND: Atherosclerosis is a chronic inflammatory disease affecting large and medium arteries. CD4+ T cells are known to play a role in the progression of the disease. CD4+CD25+Foxp3+ natural Treg (nTreg) cells seem to have a protective role in the disease and their reduction in acute coronary syndrome is recently shown. OBJECTIVE: To investigate the frequency of nTreg subsets in the peripheral blood of patients with atherosclerosis. METHODS: Confirmation of atherosclerosis was done by angiography and 15 ml heparinized blood was obtained from each of the 13 non-diabetic patients and 13 non-diabetic, non-smoker individuals with normal/insignificant coronary artery disease confirmed by angiography. Lipid profiles of the patients and controls were measured at the time of sampling. Mononuclear cells were used for both RNA extraction and immunophenotyping by real-time PCR and flowcytometry techniques, respectively. RESULTS: In natural Treg subsets, the frequency of CD4+CD45RO-CD25+Foxp3lo T-cells (resting nTregs) was greater in controls than patients (p=0.02). The frequency of CD4+CD45RO+CD25hiFoxp3hi T-cells (activated nTregs) was significantly higher in controls compared with patients (p=0.02). However, the frequency of CD4+CD25+CD45RO+Foxp3- T-cells (effector/memory T-cell) increased in patients compared with controls (p=0.01). Both the MFI and gene expression of Foxp3 were higher in control group than in patients (p=0.015 and p=0.017, respectively). Moreover, the TGF-ß gene expression showed a decrease in the peripheral blood mononuclear cells of patients compared with controls (p=0.03). CONCLUSION: Decrease in both subsets of resting and activated nTregs along with a decrease in the expression of Foxp3 and TGF-ß genes in patients with atherosclerosis suggests phenotypic changes in these subsets, which may as well be correlated with a more inflammatory profile in their lymphocytes.