Carbon dots-embedded N-acetylneuraminic acid and glucuronic acid-imprinted polymers for targeting and imaging of cancer cells.

Diagnosis, treatment, and prediction of cancer progression require new targeting agents to specifically target cell surface receptors. Herein, we demonstrated fluorescent carbon quantum dots-molecularly imprinted polymer (CQD-MIP) for selective targeting and imaging of cancer cells. Carbon quantum dots (CQDs) were synthesized and characterized. The synthesized CQDs had average size of 1.5 nm and show intense fluorescence emission at wavelength of 450 nm with excitation at 370 nm. CQD-MIP nanoparticles imprinted with N-acetylneuraminic acid and glucuronic acid were prepared and characterized. CQD-MIPs were successfully applied for selective targeting and imaging of MCF-7, HepG-2, and NIH-3T3 cell lines. Non-imprinted polymer (NIP) showed no binding properties toward a target molecule. Non-imprinted polymer (NIP) and non-cancerous human cell lines were used for controlling the imprinting and targeting effects, respectively. Acceptable results were obtained with imprinted polymers on cancer cells.

Molecular typing of Clostridium difficile isolates cultured from patient stool samples and gastroenterological medical devices in a single Iranian hospital.

This study aimed to characterize Clostridium difficile isolates cultured from stool samples of patients with C. difficile infection (CDI) and swabs from a medical environment in a gastroenterology center in Tehran, Iran. A total of 158 samples (105 stool samples from hospitalized patients and 53 swabs from medical devices and the environment) were collected from January 2011 to August 2011 and investigated for the presence of C. difficile by direct anaerobic culture on a selective media for C. difficile. C. difficile isolates were further characterized by capillary electrophoresis (CE) ribotyping and toxin gene multiplex PCR. Of 158 samples, C. difficile was cultured in 19 of 105 stool samples (18%) and in 4 of 53 swabs (7.5%). C. difficile PCR ribotype (RT) 126 was the most common RT in the study (21.7%). Further RTs were: 001, 003, 014, 017, 029, 039, 081, 103 and 150. RTs 126, 001, 150 were cultured from both the stool samples and swabs of medical devices and the hospital environment which suggest a possible route of transmission.

The frequency of bacterial contamination and diversity of drug resistance patterns in devices and staff of endoscopy and colonoscopy units.

Background: This study aimed at analyzing microbial contamination in medical equipment, environment, and staff of a gastroenterology unit. Methods: Samples of gastrointestinal imaging devices, the environment, and staff were collected using standard swab-rinse technique and biochemical or molecular characteristics of the isolates, their susceptibility to antibiotics, and similarity of the resistance patterns were investigated. Results: Out of 107 samples, bacterial contamination was detected in the hands of staff (54.1%), imaging devices (56.7%), and in the environment (54.5%). While Pseudomonas spp. were detected only in the imaging devices (13.5%), Bacillus spp. (32.4% and 31.5%), Enterococcus spp. (14.3% and 5.9%), Clostridium difficile (10.8% and 10.5%), and Staphylococcus epidermidis (5.4% and 15.9%) were orderly the most common isolates from samples of the imaging devices and the environment. Nearly, 40% of P. aeruginosa strains were resistant to cefepime, while resistance to cephalosporins and ß-lactamase inhibitor was detected in 33% and 75% of S. aureus strains, respectively. Homology of resistance patterns was detected between the imaging devices and hands of the staff. Conclusion: Our results proposed biofilm and spore forming bacteria as main contaminants of imaging devices in this hospital. Homology of the resistance patterns proposed involvement of staff in contamination of the equipment.

Association of Emotional Response Indicators with the Risk of Recurrence and Hospitalization in Coronavirus Patients.

Anxiety, stress, and fear can adversely affect the mental and physical health of people. The present study aimed to examine the association of these emotional response indicators with outcomes (recurrence, hospitalization, and mortality) in coronavirus 2019 (COVID-19) patients. A prospective cohort study was conducted between February 2020 and July 2021 in three hospitals in Tehran, Iran. The included patients (n=350) completed three questionnaires on COVID-19-related anxiety, stress, and fear. Patients with at least one emotional response indicator were assigned to the exposed group (n=157) and those without to the unexposed group (n=193). After one month of follow-up, the medical condition of all participants was determined through phone calls. Data were analyzed with logistic and multivariate regression models using STATA 9 software. The number of patients with COVID-19 recurrence in the exposed and unexposed groups was 71 (45%) and 16 (8%), respectively, and for hospitalization 79 (50%) and 16 (8%), respectively. The relative risk of recurrence and hospitalization due to COVID-19 in the exposed group was 5.62 and 6.25 higher than in the unexposed group, respectively (P<0.001 for both). The results of regression analysis showed that underlying diseases were not significantly associated with recurrence and hospitalization. The total number of deaths was six, all of which were in the exposed group. Given the greater risk of recurrence and hospitalization in COVID-19 patients with anxiety, stress, or fear, there is a need to devise and implement appropriate strategies to prevent and manage mental disorders.

Enhancing methane production of co-digested food waste with granular activated carbon coated with nano zero-valent iron in an anaerobic digester.

Anaerobic digestion (AD) possesses dual benefits of waste treatment and energy generation. The use of conductive additives in AD matrix has potential to improve process yield. Hence, the study aimed to investigate a thermophilic AD (TAD) inserted by granular activated carbon coated with nano zero-valent iron (GAC/nZVI) in the matrix and was operated for mono-digestion and co-digestion of cow manure with food wastes (rice and bread) to check the bioprocess improvement. The results were compared with the control TAD without conductive additives. Biogas production increased by 11 folds upon using GAC/nZVI addition compared to the control TAD. Moreover, the addition of GAC/nZVI increased the methane in biogas by 20.7 folds compared to control one. With GAC/nZVI, the maximum COD removal of 78.29% and 85.21% were noticed for co-digestion and mono digestion, respectively. Such improvement of TAD performance was due to easy bacterial communication and electron exchange through the conductive particles.

Shiga toxin-producing bacteria as emerging enteric pathogens associated with outbreaks of foodborne illness in the Islamic Republic of Iran.

BACKGROUND: Detection of the cause of diarrhoeal diseases is important for the management of the outbreaks. AIMS: This study investigated the prevalence of Shiga toxin-producing bacteria in stool samples of patients with diarrhoea associated with outbreaks of foodborne illness in the Islamic Republic of Iran. METHODS: A total of 532 stool and rectal swab samples from 70 sporadic outbreaks during May 2014 to August 2015 were examined for infection with Shiga toxin-producing bacteria. The isolates were examined for carriage of the virulence genes stx1 and stx2 in all isolates and eae/ehxA in Escherichia coli. RESULTS: E. coli, Shigella spp., Citrobacter spp., Enterobacter spp., Klebsiella spp. and other enteric bacteria were detected in 77.7% (376/484), 5.0% (24/484), 3.9% (19/484), 0.4% (2/484), 3.7% (18/484) and 9.3% (45/484) of the samples respectively. Of the 196 sorbitol-negative E. coli strains, 3 (1.5%) carried the stx1 gene as did 2 of the 19 (10.5%) Citrobacter strains. CONCLUSION: Shiga toxin-producing Citrobacter spp. strains should be considered as a newly emerging foodborne pathogen in outbreaks.

Effect of Mechanical Load Cycling on Microleakage of Restorative Glass Ionomers Compared to Flowable Composite Resin in Class V Cavities.

OBJECTIVES: Microleakage is the most important factor responsible for the destruction of restoration margins. The aim of this study was to assess the effect of mechanical load cycling on microleakage of four types of glass ionomer cement (GIC) in comparison with a flowable composite resin. MATERIALS AND METHODS: In this in-vitro experimental study, 100 Class V cavities were prepared on the buccal and lingual surfaces of 50 intact premolars. The prepared cavities were divided into five groups of (A) Z350, (B) Equia Forte, (C) encapsulated Fuji II LC, (D) hand-mixed Fuji II LC, and (E) Ketac Molar. All the samples were thermocycled (×2,000, 5-55°C), and half of the samples in each group were load cycled. All the teeth were then immersed in 0.5% basic fuchsine for 24 hours, sectioned, and observed under a stereomicroscope. Data were analyzed with Kruskal-Wallis and Mann-Whitney-U tests. Comparison between the incisal and gingival microleakage was made with Wilcoxon test. P<0.05 was considered statistically significant. RESULTS: Load cycling and type of restorative material had a significant effect on microleakage. Gingival microleakage was significantly higher than occlusal microleakage with Equia Forte, encapsulated Fuji II LC, hand-mixed Fuji II LC, and Ketac Molar in the absence of loading, and with Z350 after loading. CONCLUSION: The sealing ability of Z350 under load cycling was better than that of Equia Forte, hand-mixed Fuji II LC, and Ketac Molar. The marginal integrity of encapsulated Fuji II LC was not significantly different than that of Z350.

Characterization of clarithromycin heteroresistance among Helicobacter pylori strains isolated from the antrum and corpus of the stomach.

Mixed infections and heteroresistance of Helicobacter pylori contribute to decreased efficacy of treatments. This study aimed to investigate frequency of clarithromycin heteroresistance and its link with mixed infections, medication history, and disease severity. A total of 40 pairs of H. pylori strains were isolated from the antrum and corpus of 97 patients. Susceptibility of the strains to clarithromycin was measured by agar dilution method. Site-specific mutations of 23S rRNA at A2143G, A2142G, and A2142C positions were analyzed by PCR and genomic relatedness of pairs of the strains was determined by random amplified polymorphic DNA (RAPD)-PCR. The results showed a prevalence of 35% (14/40) clarithromycin resistance. Diversity of the antrum and corpus isolates in resistance to clarithromycin was detected among 17.5% (7/40) of the patients. Similarly, diversity in MIC value was also detected in two patients infected with the sensitive strains. Significant difference in frequency of resistance was detected among patients with peptic ulcer disease (PUD) (MIC90 32 µg/mL) and severe gastritis (MIC90 16 µg/mL), compared with those who suffered from non-ulcer dyspepsia (NUD) (MIC90 8 µg/mL) and chronic gastritis (MIC90 0.25 µg/mL). MIC values showed 8-32 folds increased levels in the corpus. A2142G, A2143G, and A2142C mutations were detected in three, two, and two patients, respectively, but not observed in 46% of the resistant strains. RAPD-PCR fingerprints showed identical molecular patterns for the isolates of the corpus and antrum in each patient. In conclusion, microevolution of H. pylori strains during chronic infection, rather than mixed infection, and inappropriate medication appear to be main reasons of treatment failure in adults.

Safety and effectiveness of selective carotid angioplasty prior to cardiac surgery: a single-centre matched case-control study.

OBJECTIVES: Reducing the rate of postoperative stroke after cardiac surgery remains challenging, especially in patients with occlusive cerebrovascular disease. Angioplasty in all patients with high-grade carotid artery stenosis has not been shown to be effective in reducing the post-surgical stroke rate. In this study, we present the initial results of a different approach using selective carotid angioplasty only in patients with poor intracranial collaterals. METHODS: We conducted a single-centre study to assess the safety of this procedure. The postangioplasty complication rate of the study group was compared to that of patients who were scheduled for symptomatic carotid artery angioplasty. To determine the effectiveness of this procedure, the post-cardiac surgery complication rate of the study group was compared with that of the matched case controls. RESULTS: Twenty-two patients were treated with selective carotid angioplasty without developing persistent major neurological complications. All patients except 1 patient subsequently underwent surgery without developing persistent major neurological disabilities. Two patients died of cardiogenic shock within 30 days. CONCLUSIONS: Selective carotid angioplasty prior to cardiac surgery in patients with a presumed high risk of stroke was relatively safe and effective in this study group. Although this strategy does not prevent stroke in these high-risk patients, data suggest that this approach shifts the postoperative type of stroke from a severe haemodynamic stroke towards a minor embolic stroke with favourable neurological outcomes. Larger studies are needed to determine whether this strategy can effectively eliminate the occurrence of haemodynamic stroke after cardiac surgery.

In vitro evaluation of veneering composites and fibers on the color of fiber-reinforced composite restorations.

OBJECTIVE: Color match between fiber-reinforced composite (FRC) restorations and teeth is an imperative factor in esthetic dentistry. The purpose of this study is to evaluate the influence of veneering composites and fibers on the color change of FRC restorations. MATERIALS AND METHODS: Glass and polyethylene fibers were used to reinforce a direct microhybrid composite (Z250, 3M ESPE) and a microfilled composite (Gradia Indirect, GC). There were eight experimental groups (n=5 disks per group). Four groups were used as the controls (non-FRC control) and the others were used as experimental groups. CIELAB parameters (L*, a* and b*) of specimens were evaluated against a white background using a spectrophotometer to assess the color change. The color difference (ΔE*) and color coordinates were (L*, a* and b*) analyzed by two-way ANOVA and Tukey's test. RESULTS: Both types of composite and fiber influenced the color parameters (ΔL*, Δa*). The incorporation of fibers into the composite in the experimental groups made them darker than the control groups, except in the Gradia Indirect+ glass fibers group. Δb* is affected by types of fibers only in direct fiber reinforced composite. No statistically significant differences were recognized in ΔE* among the groups (p>0.05). CONCLUSION: The findings of the present study suggest that the tested FRC restorations exhibited no difference in color in comparison with non-FRC restoration. Hence, the types of veneering composites and fibers did not influence the color change (ΔE*) of FRC restorations.