Antimicrobial resistance patterns, virulence genes, and biofilm formation in enterococci strains collected from different sources.

BACKGROUND: Currently, antibiotic-resistant strains of Enterococcus are considered to be one of the critical health challenges globally. This study aimed to investigate the antibiotic susceptibility pattern, biofilm formation capacity, and virulence genes of enterococci isolated from different sources. METHODS: In this cross-sectional study, environmental and fecal samples were collected from the hospital environment, volunteers, and hospital staff from October 2018 to August 2019. The isolates were identified by morphological and biochemical tests (gram staining, catalase, bile resistance, esculin hydrolysis, carbohydrate fermentation, growth in 6.5% NaCl, Pyrrolidonyl arylamidase, arginine dehydrolase), and PCR for ddl gene. An antimicrobial susceptibility test was performed by the standard disk agar diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Quantitative microplate assays were used to assess biofilm production. The bacterial DNAs were extracted by alkaline lysis method and polymerase chain reaction technique was used detect the esp, ace, and efaA virulence genes. RESULTS: Out of 145 isolates, 84 (57.9%) were identified as E. faecalis and 61 (42.1%) as E. faecium. Resistance to kanamycin and quinupristin-dalfopristin was 82.1% (69/84) and 85.7% (72/84), respectively, in E. faecalis isolates. Out of 61 E. faecalis isolates, 38 (62.4%) were resistant to kanamycin. Among the E. faecalis isolates, esp was the most dominant virulence gene (73.80%), followed by efaA, and ace, which were detected in 60.71%, and 30.95% isolates, respectively. In total, 68.27% of the strains were biofilm producers. Further, esp and efaA genes were more frequently found among E. faecalis strains with moderate and strong biofilm biomass. CONCLUSIONS: According to the findings of our study, enterococci strains isolated from different samples possess distinctive patterns of virulence genes. The esp, ace, and efaA genes were more prevalent among E. faecalis than E. faecium. Besides, the high level antibiotic resistance of normal flora and environmental enterococci strains is alarming the researchers.

Characterization of Antimicrobial Activities of Bifidobacterium lactis BB-12 and Their Inhibitory Effect Against Some Foodborne Pathogens.

Bifidobacterium animalis subsp. lactis BB-12, a probiotic, has shown potential to promote health benefits and control pathogens. This study aimed to investigate the effectiveness of BB-12 and its cell-free supernatant (CFS) in inhibiting the growth of Listeria monocytogenes and Salmonella enterica serovar Typhimurium. To assess the antimicrobial activity of BB-12, agar well diffusion, disk diffusion, and minimum inhibitory concentration (MIC) tests were conducted. The bicinchoninic acid (BCA) assay was performed to measure the protein concentration in CFS. The study's results indicated that the BB-12 strain inhibited the pathogens' growth. The disk diffusion test using BB-12 showed inhibitory results ranging from 11 to 14 mm for both bacteria. The agar well diffusion test reported the zone of inhibition ranging from 11.6 to 16 mm for both bacteria. The MIC test was conducted as a confirmatory test, which demonstrated the highest inhibitory zone using 2 McFarland (6 × 108 CFU/mL) concentrations of probiotics on L. monocytogenes (44.98%) and S. Typhimurium (66.41%). The disk diffusion test revealed that the probiotic CFS had a significant inhibitory impact on S. Typhimurium with a 16.6 mm zone of inhibition. The BCA test findings indicated that the 24- and 48-h CFSs exhibited inhibitory properties against infections. Notably, the 24-h CFS, including a protein level of 78.47 µg/mL, demonstrated a more pronounced inhibitory impact on both pathogens. The findings highlight that utilizing the BB-12 strain and its CFS can serve as a viable approach to battle infections, enhancing food safety and public health.

The Role of MexCD-OprJ and MexEF-OprN Efflux Systems in the Multiple Antibiotic Resistance of Pseudomonas aeruginosa Isolated from Clinical Samples.

Increasing antimicrobial resistance and the development of multi-drug resistant (MDR) Pseudomonas aeruginosa is dependent on the expression of efflux pumps. This study aimed to investigate the role of overexpression of MexCD-OprJ and MexEF-OprN efflux pumps in reduced susceptibility to antimicrobial agents among P. aeruginosa strains. Totally, 100 clinical isolates of P. aeruginosa were collected from patients and the strains were identified by standard diagnostic tests. The MDR isolates were detected using the disk agar diffusion method. The expression levels of MexCD-OprJ and MexEF-OprN efflux pumps were evaluated by the real-time PCR. Forty-one isolates showed MDR phenotype, while piperacillin-tazobactam and levofloxacin were the most- and least-effective antibiotics, respectively. Also, all 41 MDR isolates showed a more than tenfold increase in the expression of mexD and mexF genes. In this study, a significant relationship was observed between the rate of antibiotic resistance, the emergence of MDR strains, and increasing the expression levels of MexEF-OprN and MexCD-OprJ efflux pumps (P < 0.05). Efflux systems mediated resistance was a noteworthy mechanism causative to multidrug resistance in P. aeruginosa clinical isolates. The study results demonstrated mexE and mexF overexpression as the primary mechanism conferring in the emergence of MDR phenotypes among P. aeruginosa strains. In addition, we also show that piperacillin/tazobactam exhibited a stronger ability in the management of infections caused by MDR P. aeruginosa in this area.

Tigecycline antibacterial activity, clinical effectiveness, and mechanisms and epidemiology of resistance: narrative review.

Tigecycline is unique glycylcycline class of semisynthetic antimicrobial agents developed for the treatment of polymicrobial infections caused by multidrug-resistant Gram-positive and Gram-negative pathogens. Tigecycline evades the main tetracycline resistance genetic mechanisms, such as tetracycline-specific efflux pump acquisition and ribosomal protection, via the addition of a glycyclamide moiety to the 9-position of minocycline. The use of the parenteral form of tigecycline is approved for complicated skin and skin structure infections (excluding diabetes foot infection), complicated intra-abdominal infections, and community-acquired bacterial pneumonia in adults. New evidence also suggests the effectiveness of tigecycline for the treatment of severe Clostridioides difficile infections. Tigecycline showed in vitro susceptibility to Coxiella spp., Rickettsia spp., and multidrug-resistant Neisseria gonnorrhoeae strains which indicate the possible use of tigecycline in the treatment of infections caused by these pathogens. Except for intrinsic, or often reported resistance in some Gram-negatives, tigecycline is effective against a wide range of multidrug-resistant nosocomial pathogens. Herein, we summarize the currently available data on tigecycline pharmacokinetics and pharmacodynamics, its mechanism of action, the epidemiology of tigecycline resistance, and its clinical effectiveness.

High frequency of multidrug-resistant (MDR) Klebsiella pneumoniae harboring several ß-lactamase and integron genes collected from several hospitals in the north of Iran.

BACKGROUND: Klebsiella pneumoniae is one of the leading causes of hospital outbreaks worldwide. Also, antibiotic-resistant K. pneumoniae is progressively being involved in invasive infections with high morbidity and mortality. The aim of the current study was to determine antimicrobial susceptibility patterns and the incidence of resistance genes (integron types and ß-lactamase-encoded genes) among clinical isolates of K. pneumoniae. METHODS: In this cross-sectional study, a total of 100 clinical samples were obtained from hospitalized patients in three teaching hospitals in the north of Iran, from November 2018 and October 2019. Antimicrobial susceptibility testing was performed using disk agar diffusion test in line with CLSI recommendations. For colistin, minimum inhibitory concentration (MIC) was determined using broth microdilution. Based on antibiogram, multi-drug resistant (MDR) and extensive-drug resistant (XDR) strains were detected. Finally, integron types and ß-lactamase resistance genes were identified using polymerase chain reaction technique. RESULTS: The most and least clinical samples were related to the urine and bronchoalveolar lavage, respectively. Based on the antibiogram results, amikacin and gentamicin exhibited good activity against K. pneumoniae strains in vitro. The high resistance rate (93%) to ampicillin/sulbactam predicts the limited efficacy of this antibiotic, in the hospitals studied. Among all the 100 isolates, the frequency of MDR and XDR phenotypes were 58% and 13%, respectively, while no pan-drug resistant (PDR) strains were found. In the MDR K. pneumoniae strains, the prevalence of blaSHV, blaTEM, blaCTX-M-15, blaKPC, blaOXA-48, blaNDM ß-lactamase genes were 91.4%, 82.7%, 79.3%, 29.3%, 36.2% and 6.9%, respectively, however 91.4% of the isolates were carrying intI gene. Class II and III integrons were not detected in any isolates. CONCLUSION: The MDR K. pneumoniae is becoming a serious problem in hospitals, with many strains developing resistance to most available antimicrobials. Our results indicate co-presence of a series of ß-lactamase and integron types on the MDR strains recovered from hospitalized patients. The increasing rate of these isolates emphasizes the importance of choosing an appropriate antimicrobial regimen based on antibiotic susceptibility pattern.

Correlation between antimicrobial resistance and biofilm formation capability among Klebsiella pneumoniae strains isolated from hospitalized patients in Iran.

BACKGROUND: Klebsiella pneumoniae is a common cause of nosocomial infections. Antibiotic resistance and ability to form biofilm, as two key virulence factors of K. pneumoniae, are involved in the persistence of infections. The purpose of this study was to investigate the correlation between antimicrobial resistance and biofilm formation capability among K. pneumoniae strains isolated from hospitalized patients in Iran. METHODS: Over a 10-month period, a total of 100 non-duplicate K. pneumoniae strains were collected. Antibiotic susceptibility was determined by Kirby-Bauer disk diffusion method according to CLSI. Biofilm production was assessed by tissue culture plate method. Finally, polymerase chain reaction was conducted to detect four families of carbapenemase: blaIMP, blaVIM, blaNDM, blaOXA-48; biofilm formation associated genes: treC, wza, luxS; and K. pneumoniae confirming gene: rpoB. RESULTS: Most of the isolates were resistant to trimethoprim-sulfamethoxazole (52 %), cefotaxime (51 %), cefepime (43 %), and ceftriaxone (43 %). Among all the 100 isolates, 67 were multidrug-resistant (MDR), and 11 were extensively drug-resistant (XDR). The prevalence of the blaVIM, blaIMP, blaNDM, and blaOXA-48 genes were 7 , 11 , 5 , and 28 %, respectively. The results of biofilm formation in the tissue culture plate assay indicated that 75 (75 %) strains could produce biofilm and only 25 (25 %) isolates were not able to form biofilm. Among these isolates, 25 % formed fully established biofilms, 19 % were categorized as moderately biofilm-producing, 31 % formed weak biofilms, and 25 % were non-biofilm-producers. The antimicrobial resistance among biofilm former strains was found to be significantly higher than that of non-biofilm former strains (p < 0.05). Molecular distribution of biofilm formation genes revealed that 98 , 96 , and 34 % of the isolates carried luxS, treC, and wza genes, respectively. CONCLUSIONS: The rise of antibiotic resistance among biofilm-producer strains demonstrates a serious concern about limited treatment options in the hospital settings. All of the data suggest that fundamental actions and introduction of novel strategies for controlling of K. pneumoniae biofilm-related infections is essential.

Rapid and label-free electrochemical DNA biosensor based on a facile one-step electrochemical synthesis of rGO-PPy-(L-Cys)-AuNPs nanocomposite for the HTLV-1 oligonucleotide detection.

Human T cell leukemia virus type 1 (HTLV-1) as the first human retrovirus is currently a serious endemic health challenge. Despite the use of assorted molecular or serological assays for HTLV-1 detection, there are several limitations due to the lack of a confirmatory test that may affect the accuracy of the results. Herein, a novel label-free biosensor for the detection of HTLV-1 Tax gene has been reported. An electrochemical facile ecofriendly synthesis method has been demonstrated based on a synthesis of nanocomposite of reduced graphene oxide, polypyrrole, and gold nanoparticles (rGO-PPy-(l-Cys)-AuNPs) deposited on the surface of screen-printed carbon electrode. Electrochemical techniques were used to characterize and study the electrochemical behavior of the rGO-PPy-(l-Cys)-AuNPs, which exhibited a stable reference peak at 0.21 V associated with hybridization forms by applying the differential pulse voltammetry. The designed DNA biosensor presented a wide linear range from 0.1 fM to 100 µM and a low detection limit of 20 atto-molar. The proposed biosensor presented in this study provides outstanding selectivity, sensitivity, repeatability, and reproducibility.

An overview and bibliometric analysis on the colorectal cancer therapy by magnetic functionalized nanoparticles for the responsive and targeted drug delivery.

With the growing demands for personalized medicine and medical devices, nanomedicine is a modern scientific field, and research continues to apply nanomaterials for therapeutic and damaged tissue diagnosis. In this regard, substantial progress has been made in synthesizing magnetic nanoparticles with desired sizes, chemical composition, morphologies, and surface chemistry. Among these materials, nanomagnetic iron oxides have demonstrated promise as unique drug delivery carriers due to cancer treatment. This carrier could lead to responsive properties to a specific trigger, including heat, pH, alternative magnetic field, or even enzymes, through functionalization and coating of magnetic nanoparticles, along with biocompatibility, good chemical stability, easy functionalization, simple processing, and ability to localize to the tumor site with the assistance of external magnetic field. Current studies have focused on magnetic nanoparticles' utilities in cancer therapy, especially for colorectal cancer. Additionally, a bibliometric investigation was performed on the public trends in the field of the magnetic nanoparticle to drug delivery and anticancer, which represented progressing applications of these carriers in the multidisciplinary zones with a general view on future research and identified potential opportunities and challenges. Furthermore, we outline the current challenges and forthcoming research perspective for high performance and fostering advanced MNPs in colorectal cancer treatment.

Early-stage cervical cancer diagnosis based on an ultra-sensitive electrochemical DNA nanobiosensor for HPV-18 detection in real samples.

BACKGROUND: In several years ago, infection with human papillomaviruses (HPVs), have been prevalent in the worlds especially HPV type 18, can lead to cervical cancer. Therefore, rapid, accurate, and early diagnosis of HPV for successful treatment is essential. The present study describes the development of a selective and sensitive electrochemical biosensor base on DNA, for early detection of HPV-18. For this purpose, a nanocomposite of reduced graphene oxide (rGO) and multiwalled carbon nanotubes (MWCNTs) were electrodeposited on a screen-printed carbon electrode (SPCE). Then, Au nanoparticles (AuNPs) were dropped on a modified SPCE. Subsequently, single strand DNA (ssDNA) probe was immobilized on the modified electrode. The link attached between AuNPs and probe ssDNA provided by L-cysteine via functionalizing AuNPs (Cys-AuNPs). The differential pulse voltammetry (DPV) assay was also used to electrochemical measurement. The measurement was based on the oxidation signals of anthraquninone-2-sulfonic acid monohydrate sodium salt (AQMS) before and after hybridization between the probe and target DNA. RESULTS: The calibration curve showed a linear range between 0.01 fM to 0.01 nM with a limit of detection 0.05 fM. The results showed that the optimum concentration for DNA probe was 5 µM. The good performance of the proposed biosensor was achieved through hybridization of DNA probe-modified SPCE with extracted DNA from clinical samples. CONCLUSIONS: According to the investigated results, this biosensor can be introduced as a proprietary, accurate, sensitive, and rapid diagnostic method of HPV 18 in the polymerase chain reaction (PCR) of real samples.

A review on anti-adhesion therapies of bacterial diseases.

BACKGROUND: Infections caused by bacteria are a foremost cause of morbidity and mortality in the world. The common strategy of treating bacterial infections is by local or systemic administration of antimicrobial agents. Currently, the increasing antibiotic resistance is a serious and global problem. Since the most important agent for infection is bacteria attaching to host cells, hence, new techniques and attractive approaches that interfere with the ability of the bacteria to adhere to tissues of the host or detach them from the tissues at the early stages of infection are good therapeutic strategies. METHODS: All available national and international databanks were searched using the search keywords. Here, we review various approaches to anti-adhesion therapy, including use of receptor and adhesion analogs, dietary constituents, sublethal concentrations of antibiotics, and adhesion-based vaccines. RESULTS: Altogether, the findings suggest that interference with bacterial adhesion serves as a new means to fight infectious diseases. CONCLUSION: Anti-adhesion-based therapies can be effective in prevention and treatment of bacterial infections, but further work is needed to elucidate underlying mechanisms.

Correction to: A review on anti-adhesion therapies of bacterial diseases.

The presentation of Table  was incorrect. The corrected table is given below.

Extraction and purification of the H9N2 virus nucleoprotein: A simple and practical method.

Background: Avian Influenza disease annually entails a significant economic loss to the poultry industry around the world. Influenza virus is a polymorphic virus of the orthomyxoviridae family (single-stranded RNA genome), and nucleoprotein (NP) is the structural and internal protein of the virus. The aim of the work was to purify nucleoprotein for further investigations with a simple, low-cost, fast and practical method. Methods: In this study, H9N2 influenza virus was isolated in specific pathogen-free embryonated chicken eggs by allantoically inoculating 103 to 105 egg-infective doses (EID50) for 9 to 11 days, purified by 10% (W/V) polyethylene glycol (PEG) 6000 with a sucrose gradient of 60% to 30%. The influenza virus proteins were collected and prepared as fractions by preparative electrophoresis. Finally, the purified NP was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot procedures. Results: The protein analysis with SDS-PAGE and silver nitrate staining indicated that the desired samples contained purified nucleoprotein and lacked other viral proteins. The results of the investigation of lyophilized fractions containing nucleoprotein on the SDS-PAGE revealed the absence of viral RNA in nucleoprotein and its high purity. Conclusion: According to this study, purified nucleoprotein can be used to produce nucleoprotein vaccines, as well as to study structural, molecular and diagnostic and therapeutic materials.

Determination of Helicobacter pylori virulence-associated genes in duodenal ulcer and gastric biopsies.

Background:Helicobacter pylori (H. pylori or Hp) has been strongly associated with the peptic ulcer diseases, chronic gastritis, ulcers, and gastric cancer. Genes associated with pathogenicity have been designated for H. pylori, and some of them appear to be related to more severe clinical consequences of the infection. The present study was conducted to determine cagA, vacA, cagE, iceA1, oipA, and iceA2 genes in H. pylori strains isolated from gastroduodenal patients, who referred to Shariati hospital in Tehran, Iran. Methods: Gastric biopsy specimens were collected during endoscopy from patients, who referred to the Shariati hospital in Tehran, Iran during January and November 2015. After isolation of H. pylori from the biopsy culture, genomic DNA was extracted and subsequently used to identify H. pylori and virulence genes using specific primers. Results: The isolation rate of H. pylori strains was 65.7% (169/257). The frequency of cagA, vacA, cagE, iceA1, oipA, and iceA2 was 143 (% 84.6), 169 (100%), 131 (77.5%), 97 (57.3%), 89 (52.6%), and 72 (42.6%), respectively. Conclusion: In this study, a significant difference was observed between investigated genes and strains isolated from PUD and GC patients (p<0.05).

Nano-Anatase TiO2 for High Performance Optical Humidity Sensing on Chip.

An on-chip optical humidity sensor using Nano-anatase TiO2 coating is presented here. The coating material was prepared so that the result is in solution form, making the fabrication process quick and simple. Then, the solution was effortlessly spin-coated on an SU8 straight channel waveguide. Investigating the sensitivity and performance (response time) of the device revealed a great linearity in the wide range (35% to 98%) of relative humidity (RH). In addition, a variation of more than 14 dB in transmitted optical power was observed, with a response time of only ~0.7 s. The effect of coating concentration and UV treatment was examined on the performance and repeatability of the sensor. Interesting observations were found, and the attributed mechanisms were described. In addition, the proposed sensor was extensively compared with other state-of-the-art proposed counterparts from the literature and remarkable advantages were found. Since a high sensitivity of ~0.21 dB/%RH and high dynamic performances were demonstrated, this sensor is proposed for use in biomedical applications.

The effect of elderly-specific spinal orthoses on muscle function and kyphosis angle in elderly subjects: systematic review and meta-analysis.

PURPOSE: Age-related postural hyper-kyphosis is an exaggerated anterior curvature of the thoracic spine, that impairs balance and increases the risk of falls and fractures in elderly subjects. Our objectives are to review the effect of elderly-specific spinal orthoses on muscle function and kyphosis angle in this subjects. MATERIALS AND METHODS: We searched PubMed, Scopus, ISI web of Knowledge, ProQuest and Cochrane library to identify relevant studies that assessed efficacy of spinal orthoses on muscle function and kyphosis angle of elderly subjects with elderly with hyper-kyphosis. Quality assessment was implemented using the Downs and Black scale. RESULTS: Results for 709 individuals were described in 18 articles which 12 studies involved RCT. There was significant difference for kyphosis angle after use of orthosis of 148 participants (SMD: -3.79, 95% CI -7.02 to -0.56, p < 0.01). Except one study, all of studies showed significantly increased on the back muscle strength when the participants wore the spinal orthosis and this effect was significantly better in long-term follow up (MD: 84.73; 95% CIs, 23.24 to 146.23; p < 0.01). In the outcome of pain, the efficacy brought by orthosis was large and significant (SMD: -1.66; 95% CIs, -2.39 to 0.94; p < 0.01). CONCLUSIONS: Spinal orthosis may be an effective treatment for elderly hyper-kyphosis. However, the small number, and heterogeneity of the included studies, indicate that higher-quality studies should be conducted to verify the effectiveness and orthosis in hyper-kyphosis.

Age-related postural hyper kyphosis is an exaggerated anterior curvature of the thoracic spine, that impairs balance and increases the risk of falls and fractures in elderly subjects.Based on the findings of this review, elderly specific spinal orthoses may be recommended as effective device for elderly hyper kyphotic subjects.Spinal orthoses prescription is important for health practitioners to consider when planning treatment.

Overuse of computed tomography for mild head injury: A systematic review and meta-analysis.

BACKGROUND: Computed tomography (CT) scan is a common imaging technique used to evaluate the severity of a head injury. The overuse of diagnostic interventions in the health system is a growing concern worldwide. Objectives: The aim of this systematic review is to investigate the rate of CT scan overuse in cases of mild head injury. METHODS: Eligibility criteria: We encompassed observational studies-either designed as cohort, case-control, or cross-sectional investigations-that reported on CT scan overuse rates for mild head injuries. Studies had to be published in peer-reviewed, English-language sources and provide full content access Information sources: Web of Sciences, Scopus, Medline via PubMed, the Cochrane Library and Embase were searched from inception until April 1, 2023. Studies were included if reporting the overuse of CT scans for mild head injuries using validated criteria. Risk of bias: We used the Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) tool to evaluate the risk bias assessment of included studies. Two independent reviewers evaluated the eligibility of studies, extracted data, and assessed study quality by using the Newcastle-Ottawa Scale. Synthesis of results: Overuse estimates were calculated using a random-effects model. Subgroup analyses were performed to investigate any sources of heterogeneity. Point rate of overuse of CT scans for mild head injuries was the main outcome measured as percentage point estimates with corresponding 95% CIs. RESULTS: Included studies: Of the 913 potentially relevant studies identified, eight studies were selected for the final analysis. Synthesis of results: The pooled rate of CT scan overuse in patients with mild head injury was found to be 27% [95% CI: 16-43; I2 = 99%]. The rate of CT scan overuse in mild head injury cases varied depending on the criteria used. The rate of CT scan overuse was 37% [95% CI: 32-42; I2 = 0%] with the Glasgow Coma Scale (GCS), 30% [95% CI: 16-49; I2 = 99%] with the Canadian computed tomography head rule, and 10% [95% CI: 8-14; I2 = 0%] with the Pediatric Emergency Care Applied Research Network criterion (PERCAN). Based on subgroup analyses, the rate of CT scan overuse in mild head injury cases was observed to be 30% with the Canadian computed tomography head rule criterion, 43% with the National Institute for Health and Clinical Excellence criterion, and 18% with the New Orleans criterion. CONCLUSION: Limitations of evidence: The restricted number of included studies may impact generalizability. High heterogeneity was observed, leading to subgroup analyses based on age, assessment criteria, and study region. Absent data on overuse causes hinders drawing conclusions on contributing factors. Furthermore, this study solely addressed overuse rates, not associated harm or benefits. Interpretation: The overuse of CT scans in mild head injury patients is concerning, as it can result in unnecessary radiation exposure and higher healthcare costs. Clinicians and policymakers should prioritize the implementation of guidelines to reduce unnecessary radiation exposure, healthcare costs, and potential harm to patients. TRIAL REGISTRATION: The study protocol of this review was registered in PROSPERO under the identification code CRD42023416080. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023416080.

Tradeoffs between Radiation Exposure to the Lens of the Eyes and Diagnostic Image Quality in Pediatric Brain Computed Tomography.

Background: Computed tomography (CT) of the brain is associated with radiation exposure to the lens of the eyes. Therefore, it is necessary to optimize scan settings to keep radiation exposure as low as reasonably achievable without compromising diagnostic image information. The aim of this study was to compare the effectiveness of the five practical techniques for lowering eye radiation exposure and their effects on diagnostic image quality in pediatric brain CT. Methods: The following scan protocols were performed: reference scan, 0.06-mm Pbeq bismuth shield, 30% globally lowering tube current (GLTC), reducing tube voltage (RTV) from 120 to 90 kVp, gantry tilting, and combination of gantry tilting with bismuth shielding. Radiation measurements were performed using thermoluminescence dosimeters. Objective and subjective image quality was evaluated. Results: All strategies significantly reduced eye dose, and increased the posterior fossa artifact index and the temporal lobe artifact index, relative to the reference scan. GLTC and RTV increased image noise, leading to a decrease signal-to-noise ratio and contrast-to-noise ratio. Except for bismuth shielding, subjective image quality was relatively the same as the reference scan. Conclusions: Gantry tilting may be the most effective method for reducing eye radiation exposure in pediatric brain CT. When the scanner does not support gantry tilting, GLTC might be an alternative.

Evaluation of the Presence of Bacterial and Viral Agents in the Semen of Infertile Men: A Systematic and Meta-Analysis Review Study.

Objectives: Infections in the male genitourinary system with bacterial and viral agents may play a significant role in male infertility. These agents usually infect the urethra, seminal vesicles, prostate, epididymis, vas deferens, and testes retrograde through the reproductive system. A meta-analysis review study was performed to evaluate the presence of bacterial and viral agents in the semen of infertile men and its correlation with infertility. Methods: Relevant cross-sectional and/or case-control studies were found by an online review of national and international databases (Web of Science, PubMed, Scopus, Science Direct, and Google scholar), and suitable studies were selected. A checklist determined the qualities of all studies. Heterogeneity assay among the primary studies was evaluated by Cochran's Q test and I2 index (significance level 50%). A statistical analysis was conducted using the Comprehensive Stata ver. 14 package (StataCorp, College Station, TX, United States). Results: Seventy-two studies were included in this meta-analysis. Publication bias was compared with Egger's test, and the impact of each research on overall estimate was evaluated by sensitivity analysis. In 56 studies, the rate of bacterial infections in the semen of infertile men was 12% [95% confidence interval (CI): 10-13]. Also, in 26 case-control studies, the association of infertility in men with bacterial infections was evaluated. The results show that the odds ratio of infertility in men exposed to bacterial infections is 3.31 times higher than that in non-infected men (95% CI: 2.60-4.23). Besides, in 9 studies that examined the prevalence of human papillomavirus (HPV), herpes simplex virus 1 (HSV1), herpes simplex virus 2 (HSV2), and herpes simplex virus 1-2 (HSV1-2) in infertile men, the frequency of these viruses was 15% (95% CI: 9-21). In 6 case-control studies, the association between human cytomegalovirus (HCMV), Cytomegalovirus (CMV), and HPV and male infertility was evaluated. The chance of male infertility due to exposure to these viruses was 2.24 times higher than those without exposure to these viruses (CI 95%: 1.9-4.52). The results show that the chance of infertility in men exposed to bacteria was significantly higher than that in the uninfected population. Conclusion: This meta-analysis showed that viral and bacterial infections are a risk factor and could impair male fertility potential. Moreover, our study supports the hypothesis that bacterial and viral infections of the genital tract correlate positively with impairment of sperm quality in the male population.

The Efficacy of "Anatomical Posture Control Orthosis" on the Activity of Erector spinae Muscle, Risk of Falling, Balance Confidence, and Walking Speed in Osteoporotic Hyperkyphotic Subjects.

Background: Osteoporosis is a silent and asymptomatic disease that leads to thoracic hyperkyphosis, which can interfere with the normal function of the paraspinal musculature and balance control. There is no evidence regarding the effect of the anatomical posture control (APC) orthosis in older people with osteoporotic thoracic hyperkyphosis. This study aimed to examine the effects of this novel orthosis on the electromyography (EMG) of the erector spinae (ES) and balance control in this group of patients. Methods: In total, 22 elderly osteoporotic subjects with thoracic hyperkyphosis were enrolled in this study. The participants used the orthosis for 4 weeks. The clinical balance assessment scales assessing fall risk and surface EMG (sEMG) signals were recorded from the erector spinae muscles bilaterally before and after the use of orthosis. The marginal model was used with the generalized estimating equation analysis for investigating the effect of this orthosis on the sEMG of the paraspinal muscles and the balance control in this longitudinal study. Results: The normalized root mean square of sEMG of the lumbar and thoracic ES muscles reduced significantly (P<0.05), and significant improvement was observed (P<0.05) in the balance control test when the participants used this new-designed orthosis (P<0.05). Conclusion: APC orthosis can decrease the activity of ES muscles during static standing and improve the static and dynamic balance in the hyperkyphotic osteoporotic subjects.

A Survey on Exposure Parameters Variation due to Aging in Radiology Devices.

The inevitable use of medical imaging examinations and lack of a suitable alternative lead to the need to control and minimize the amount of radiation from such artificial medical sources. To assess the relation between exposure parameters and lifetime of radiology devices, quality control tests were carried out on 13 radiology devices in 11 general hospitals. In this study, a barracuda dosimeter, SE-43137 Sweden, was calibrated to measure and record the quantities of kVp, mAs and exposure parameters. In all the devices using applying the minimum and maximum values of kVp, the minimum and maximum values of the internal resistances were calculated. The lowest mR/mA for the device C was observed at a flow rate of 200 mA (equal to 2,425), while the highest value was for the device A (2) at a current intensity of 200 mA (equal to 14.625). By increasing the age of the device, the output of the device is reduced. Therefore, to compensate for this decrease in the output, higher exposure conditions are usually applied to the device, which can greatly increase the damage to the device.