Poly(2-oxazoline)-Based Thermoresponsive Stomatocytes

The design of biocompatible and biodegradable nanostructures with controlled morphological features remains a predominant challenge in medical research. Stimuli-responsive vesicles offer significant advantages in drug delivery, biomedical applications, and diagnostic techniques. The combination of poly(2-oxazoline)s with biodegradable polymers could provide exceptional biocompatibility properties and be proposed as a versatile platform for the development of new medicines. Therefore, poly(2-ethyl-2-oxazoline) (PEtOx) and poly(2-isopropyl-2-oxazoline) (PiPrOx) possessing a hydroxy terminal group that acts as an initiator for the ring-opening polymerization of d,l-lactide (DLLA) have been utilized in this study. The resulting amphiphilic block polymers were used to create polymersomes, which undergo solvent-dependent reorganization into bowl-shaped vesicles or stomatocytes. By blending PEtOx-b-PDLLA and PiPrOx-b-PDLLA copolymers, a thermoresponsive stomatocyte was generated, where the opening narrowed and irreversibly closed with a slight increase in the temperature. Detailed transmission electron microscopy analysis reveals the formation of both closed and fused stomatocytes upon heating the sample above the critical solution temperature of PiPrOx.

Impaired Peripheral Vascular Function Following Ischemic Stroke in Mice: Potential Insights into Blood Pressure Variations in the Post-Stroke Patient

High systolic blood pressure and increased blood pressure variability after the onset of ischemic stroke are associated with poor clinical outcomes. One of the key determinants of blood pressure is arteriolar size, determined by vascular smooth muscle tone and vasodilatory and vasoconstrictor substances that are released by the endothelium. The aim of this study is to outline alterations in vasomotor function in isolated peripheral arteries following ischemic stroke. The reactivity of thoracic aortic segments from male C57BL/6 mice to dilators and constrictors was quantified using wire myography. Acetylcholine-induced endothelium-dependent vasodilation was impaired after ischemic stroke (LogIC50 Sham = -7.499, LogIC50 Stroke = -7.350, p = 0.0132, n = 19, 31 respectively). The vasodilatory responses to SNP were identical in the isolated aortas in the sham and stroke groups. Phenylephrine-induced vasoconstriction was impaired in the aortas isolated from the stroke animals in comparison to their sham treatment counterparts (Sham LogEC50= -6.652 vs. Stroke LogEC50 = -6.475, p < 0.001). Our study demonstrates that 24 h post-ischemic stroke, peripheral vascular responses are impaired in remote arteries. The aortas from the stroke animals exhibited reduced vasoconstrictor and endothelium-dependent vasodilator responses, while the endothelium-independent vasodilatory responses were preserved. Since both the vasodilatory and vasoconstrictor responses of peripheral arteries are impaired following ischemic stroke, our findings might explain increased blood pressure variability following ischemic stroke.

Can we use serum SCUBE 1 levels as a biomarker in obstructive sleep apnea hypopnea syndrome?

OBJECTIVE

To examine the SCUBE1 level, a biomarker in vascular biology that could determine the prognosis of cardiovascular events during OSA treatment.

METHODS

In total, 129 patients were included in the study. Thirty were diagnosed with simple snoring and 99 with OSA.

RESULTS

In males, significant correlation was determined between SCUBE1 non-REM AHI, hypopnea index, total apnea index, mean SO2, minimum SO2, and < 90% saturation duration.

CONCLUSION

Serum SCUBE1 levels increased more in male patients with severe OSA compared to other OSA levels, and high serum SCUBE1 levels were found to be associated with lower oxygen levels in OSA patients. The SCUBE1 biomarker can correlate with severe OSA in males. There was a statistically significant difference between OSA groups in terms of SCUBE1 score for male patients (p = 0.002) but not for females (p = 0.498). It is important that future SCUBE1 studies evaluate males vs. females.

Design, implementation and usability analysis of patient empowerment in ADLIFE project via patient reported outcome measures and shared decision making

INTRODUCTION

This paper outlines the design, implementation, and usability study results of the patient empowerment process for chronic disease management, using Patient Reported Outcome Measurements and Shared Decision-Making Processes.

BACKGROUND

The ADLIFE project aims to develop innovative, digital health solutions to support personalized, integrated care for patients with severe long-term conditions such as Chronic Obstructive Pulmonary Disease, and/or Chronic Heart Failure. Successful long-term management of patients with chronic conditions requires active patient self-management and a proactive involvement of patients in their healthcare and treatment. This calls for a patient-provider partnership within an integrated system of collaborative care, supporting self-management, shared-decision making, collection of patient reported outcome measures, education, and follow-up.

METHODS

ADLIFE follows an outcome-based and patient-centered approach where PROMs represent an especially valuable tool to evaluate the outcomes of the care delivered. We have selected 11 standardized PROMs for evaluating the most recent patients' clinical context, enabling the decision-making process, and personalized care planning. The ADLIFE project implements the "SHARE approach' for enabling shared decision-making via two digital platforms for healthcare professionals and patients. We have successfully integrated PROMs and shared decision-making processes into our digital toolbox, based on an international interoperability standard, namely HL7 FHIR. A usability study was conducted with 3 clinical sites with 20 users in total to gather feedback and to subsequently prioritize updates to the ADLIFE toolbox.

RESULTS

User satisfaction is measured in the QUIS7 questionnaire on a 9-point scale in the following aspects: overall reaction, screen, terminology and tool feedback, learning, multimedia, training material and system capabilities. With all the average scores above 6 in all categories, most respondents have a positive reaction to the ADLIFE PEP platform and find it easy to use. We have identified shortcomings and have prioritized updates to the platform before clinical pilot studies are initiated.

CONCLUSIONS

Having finalized design, implementation, and pre-deployment usability studies, and updated the tool based on further feedback, our patient empowerment mechanisms enabled via PROMs and shared decision-making processes are ready to be piloted in clinal settings. Clinical studies will be conducted based at six healthcare settings across Spain, UK, Germany, Denmark, and Israel.

Optimization of RT-QuIC Assay Duration for Screening Chronic Wasting Disease in White-Tailed Deer

Real-time quaking-induced conversion (RT-QuIC) assays have become a common tool to detect chronic wasting disease (CWD) and are very sensitive provided the assay duration is sufficient. However, a prolonged assay duration may lead to non-specific signal amplification. The wide range of pre-defined assay durations in current RT-QuIC applications presents a need for methods to optimize the RT-QuIC assay. In this study, receiver operating characteristic (ROC) analysis was applied to optimize the assay duration for CWD screening in obex and retropharyngeal lymph node (RLN) tissue specimens. Two different fluorescence thresholds were used: a fixed threshold based on background fluorescence (Tstdev) and a max-point ratio (maximum/background fluorescence) threshold (TMPR) to determine CWD positivity. The optimal assay duration was 33 h for obex and 30 h for RLN based on Tstdev, and 29 h for obex and 32 h for RLN based on TMPR. The optimized assay durations were then evaluated for screening CWD in white-tailed deer from an affected farm. At a replicate level, using the optimized assay durations with TStdev and TMPR, the level of agreement with enzyme-linked immunosorbent assay (ELISA) was significantly higher (p < 0.05) than that when using a 40 h assay duration. These findings demonstrate that the optimization of assay duration via a ROC analysis can improve RT-QuIC assays for screening CWD in white-tailed deer.

Poly(2-oxazoline)/saRNA Polyplexes for Targeted and Nonviral Gene Delivery

RNA delivery has been demonstrated to be a potent method of vaccine delivery, as demonstrated by the recent success of the COVID-19 vaccines. Polymers have been shown to be effective vehicles for RNA delivery, with poly(ethylene imine) (PEI) being the current gold standard for delivery. Nonetheless, PEI has toxicity concerns, and so finding alternatives is desirable. Poly(2-oxazoline)s are a promising alternative to PEI, as they are generally biocompatible and offer a high degree of control over the polymer structure. Here, we have synthesized an ionizable primary amine 2-oxazoline and combined it with a double bond containing oxazoline to synthesize a small library of charged statistical and block copolymers. The pendant double bonds were reacted further to decorate the polymers with glucose via a thiol-ene click reaction. All polymers were shown to have excellent cell viability, and the synthesized block polymers showed promising complexation efficiencies for the saRNA, demonstrating a clear structure-property relationship. The polymer transfection potential was tested in various cell lines, and a polymer composition with an amine/glucose ratio of 9:27 has demonstrated the best transfection potential across all cell lines tested. Overall, the results suggest that block polymers with a cationic segment and high levels of glycosylation have the best complexation efficiency and RNA expression levels.

Step-Growth Glycopolymers with a Defined Tacticity for Selective Carbohydrate-Lectin Recognition

Glycopolymers are potent candidates for biomedical applications by exploiting multivalent carbohydrate-lectin interactions. Owing to their specific recognition capabilities, glycosylated polymers can be utilized for targeted drug delivery to certain cell types bearing the corresponding lectin receptors. A fundamental challenge in glycopolymer research, however, is the specificity of recognition to receptors binding to the same sugar unit (e.g., mannose). Variation of polymer backbone chirality has emerged as an effective method to distinguish between lectins on a molecular level. Herein, we present a facile route toward producing glycopolymers with a defined tacticity based on a step-growth polymerization technique using click chemistry. A set of polymers have been fabricated and further functionalized with mannose moieties to enable lectin binding to receptors relevant to the immune system (mannose-binding lectin, dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin, and dendritic and thymic epithelial cell-205). Surface plasmon resonance spectrometry was employed to determine the kinetic parameters of the step-growth glycopolymers. The results highlight the importance of structural complexity in advancing glycopolymer synthesis, yet multivalency remains a main driving force in lectin recognition.

The role of TAS2R38 genotype in surgical outcomes and culturable bacteria in chronic rhinosinusitis with or without nasal polyps

BACKGROUND

Recent studies reported the relationship between genetic variations and TAS2R38, which is a bitter taste receptor expressed in the cilia of human sinonasal epithelial cells, among the predisposing factors playing role in immune response to upper respiratory tract bacterial infection. The present study aims to examine the relationship of TAS2R38 genotype with the active microorganism and the effect of genotype on the surgical outcomes among chronic rhinosinusitis patients.

METHODOLOGY

34 patients undergoing endoscopic sinus surgery (ESS) for chronic rhinosinusitis with or without polyps (23 CRSwNP, 11 CRSsNP) and 30 patients undergoing septoplasty surgery for isolated nasal septum deviation were included. All the patients were genotyped for TAS2R38. Scoring was made using endoscopic Modified Lund-Kennedy and radiological Lund-Mackay systems preoperatively. Sino-Nasal Outcome Test with 22 items (SNOT-22) was implemented preoperatively and postoperatively. Nasal swab culture samples were taken intraoperatively from CRS patients and the active microorganism were isolated.

RESULTS

In the TAS2R38 genotyping of the study group, PAV/PAV was found in 32.4% of patients, PAV/AVI in 47.1%, and AVI/AVI in 20.6%. In the control group, PAV/PAV was found in 26.7%, PAV/AVI in 36.7%, and AVI/AVI in 36.7%. In the study group, there was no statistically significant difference between the CRS and CRS subgroups in terms of TAS2R38 genotype distributions. The changes in patients' preoperative and postoperative SNOT-22 scores were similar between the genotypes. Proliferation was detected in culture in the whole AVI-AVI group, 81.8% of PAV-PAV group, and 56.3% of PAV-AVI group but the difference was not found to be statistically significant. The proliferation level of Staphylococcus epidermidis by TAS2R38 genotype was found to be statistically significantly higher among patients, who had AVI-AVI genotype, in CRSwNP.

CONCLUSIONS

We did not find a statistically significant relationship between the TAS2R38 genotype and CRS subtype, sinonasal bacterial infection risk increase and surgical success rate in CRS patients. Long-term and large-scale studies are needed, which are to be carried out by individual genotyping and sequencing to provide more information on the effects of these genetic variants.

Treatment Approach of Acute Coronary Thrombosis without Dissection in a Bleeding Patient with Multiple Trauma

Trauma is one of the causes of acute myocardial infarction (AMI). In the literature, coronary dissection or vasospasm is thought to play a role in the aetiology of AMI, but the presence of coronary thrombosis without coronary dissection is uncommon. If bleeding pathologies occur in addition to traumatic coronary thrombosis, this may make the situation more complicated. A 32-year male patient was brought to a tertiary emergency service due to a car accident. We detected femoral shaft fracture, hemothorax, subdural haemorrhage, and coronary thrombosis without dissection in the patient. A chest tube was inserted and emergency coronary angiography was performed. Total occlusion of the left anterior descending artery (LAD) was detected. Balloon angioplasty was done and a stent was applied to the LAD. Acetyl salicylic acid and clopidogrel were started despite his bleeding pathologies. In trauma patients, coronary thrombosis without coronary dissection may occur with bleeding pathologies. Electrocardiography should be performed in patients with chest trauma. Thrombosis-bleeding balance should be carefully evaluated during treatment and treatment should be determined by taking this situation into consideration. Key Words: Coronary thrombosis, Multiple trauma, Bleeding, Angioplasty, Antiplatelet therapy.

The Effects of Lipopolysaccharide Derivatives in Rodent Models of Cardiac Arrhythmia

BACKGROUND

Several previous studies have suggested that sublethal doses of Escherichia coli lipopolysaccharide (endotoxin) and monophosphoryl lipid A Re595, a nonpyrogenic derivative of Salmonella minnesota lipopolysaccharide, exhibit antiarrhythmic effects in the rat model of ischemia-reperfusion arrhythmias.

METHODS

In this study, the protective effect of lipopolysaccharide derivatives was also further investigated in drug (aconitine or ouabain)-induced arrhythmia models, and conclusions were drawn with particular emphasis on the molecular characteristics of different types of lipopolysaccharide.

RESULTS

The importance of the molecular structure for the antiarrhythmic effect of monophosphoryl lipid A and E. coli lipopolysaccharide was tested in the ischemia-reperfusion arrhythmia model. In contrast to monophosphoryl lipid A from Salmonella typhimurium SL 684 which has only monophosphoryl residue in its structure, monophosphoryl lipid A Re595, obtained from S. minnesota, and E. coli lipopolysaccharide which have both mono and diphosphoryl residue reduced the duration of ventricular tachycardia (e.g., during reperfusion: vehicle: 176 ± 22.8; monophosphoryl lipid A Re595: 132.83 ± 12.1, as second, n=8-10, P < .05) and the incidence of ventricular fibrillation. The antiarrhythmic effects of E. coli lipopolysaccharide and monophosphoryl lipid A Re595 in ischemia-reperfusion arrhythmia model were absent in either aconitine- (e.g., onset time for ventricular ectopic beats: saline 25.3 5.0, E. coli lipopolysaccharide 24.3 ± 7.1; vehicle: 24.0 ± 4.5, monophosphoryl lipid A SL684 23.8 ± 4.3, as second, n=6, P > .05) or ouabain-induced arrhythmia models in mice.

CONCLUSION

Therefore, we conclude that lipopolysaccharide derivatives exhibit antiarrhythmic effect only in ischemia-reperfusion arrhythmias, and lipopolysaccharide should possess diphosphoryl groups in its subcomponent composition for this antiarrhythmic effect.

Learning Curve of Laparoscopic Surgery for Colorectal Cancer at a New Regional State Hospital: A Single-Surgeon Experience Of 106 Consecutive Cases Without Supervision

BACKGROUND

Laparoscopic surgery for colorectal cancer is mostly performed in university hospitals or experienced centers. This study aimed at determining the learning curve of laparoscopic surgery for colorectal cancer at a new regional state hospital.

PATIENTS AND METHODS

Clinico-pathological data of 106 consecutive patients who underwent laparoscopic surgery for colorectal cancer at a new regional state hospital between August 2018 and September 2021 were prospectively recorded and analyzed. All surgeries were performed by a single inexperienced surgeon without supervision. The primary outcome of the study was the operative time, which was used for a Cumulative Sum (CUSUM) analysis of the learning curve. The secondary outcomes included a comparison of preoperative, intraoperative, and postoperative outcomes during the learning curve period.

RESULTS

According to the CUSUM analysis, the learning curve consisted of three unique phases: phase 1 [the initial learning period (cases 1-53)], phase 2 [the consolidation period (cases 54-68)], and phase 3 [the experienced period (cases 69-106)]. Of the intraoperative outcomes, operative time and estimated blood loss were significantly reduced from phase 1 to phase 3 (p<0.001). Of the postoperative outcomes, time to pass stool (p<0.05), time to oral feeding (p=0.001), drain removal time (p<0.001), and length of hospital stay (p=0.042) were shorter in phase 3 compared to phases 1 and 2. Of the histopathological results, the specimen length and the number of harvested lymph nodes increased with experience (p=0.001).

CONCLUSIONS

The present results suggest that a surgeon at a new regional state hospital must experience 53-68 cases to achieve competence in laparoscopic colorectal cancer surgery.

An Analysis of Percutaneous Endoscopic Gastrostomy Complications

OBJECTIVE

To determine the indications of early and late complications in 224 patients who underwent Percutaneous Endoscopic Gastrostomy (PEG) procedure.

STUDY DESIGN

Observational study.

PLACE AND DURATION OF STUDY

Department of General Surgery, Karatay University and Medipol University, Turkey, from January 2014 to December 2020.

METHODOLOGY

Patients' age, gender, primary diseases, PEG indications, morbidity, mortality, and complications were recorded by performing the PEG procedure. Hospitalisation, follow-up periods of the patients, and the re-insertion of PEG were evaluated.

RESULTS

The most common indication for PEG tube insertion was nutritional disorder associated with cerebrovascular diseases in 81 (37%) patients. No mortality was perceived due to the PEG tube insertion. However, mortality was observed in 84 (38.4%) patients in the first six months, in 6 (2.7%) patients between the sixth and twelfth month, and in 8 (3.7%) patients after the twelfth month. All these mortalities were attributed to the primary disease. In the early and late periods, complications were observed in the total of 45 (20.4%) patients. Among them, 17 (7.7%) patients experienced early period complications, whereas 28 (12.7%) patients experienced late period complications.

CONCLUSION

Enteral nutrition should be preferred in order to avoid complications of parenteral nutrition in the patients who need long-term nutrition. In enteral nutrition, PEG should be preferred to surgical gastrostomy because it has less morbidity and mortality, can be done at the bedside and outpatiently when necessary, does not require general anesthesia, and is cheaper and practical.

KEY WORDS

Gastrostomy, Percutaneous Endoscopic gastrostomy, Enteral nutrition, PEG complications.

Hierarchy of Complex Glycomacromolecules: From Controlled Topologies to Biomedical Applications

Carbohydrates bearing a distinct complexity use a special code (Glycocode) to communicate with carbohydrate-binding proteins at a high precision to manipulate biological activities in complex biological environments. The level of complexity in carbohydrate-containing macromolecules controls the amount and specificity of information that can be stored in biomacromolecules. Therefore, a better understanding of the glycocode is crucial to open new areas of biomedical applications by controlling or manipulating the interaction between immune cells and pathogens in terms of trafficking and signaling, which would become a powerful tool to prevent infectious diseases. Even though a certain level of progress has been achieved over the past decade, synthetic glycomacromolecules are still lagging far behind naturally existing glycans in terms of complexity and precision because of insufficient and inefficient synthetic techniques. Currently, specific targeting at a cellular level using synthetic glycomacromolecules is still challenging. It is obvious that multidisciplinary collaborations are essential between different specialized disciplines to enhance the carbohydrate receptor-targeting paradigm for new biomedical applications. In this Perspective, recent developments in the synthesis of sophisticated glycomacromolecules are highlighted, and their biological and biomedical applications are also discussed in detail.

The diagnostic importance of periostin as a biomarker in chronic rhinosinusitis with nasal polyp

PURPOSE

The current studies in the literature report that periostin contributes to the formation of nasal polyps and may be a molecular biomarker for chronic rhinosinusitis with nasal polyps (CRSwNP). This study aims to investigate the effect of periostin in determining polyp burden in CRSwNP patients and evaluate its impact on postoperative surgical results and its functionality as a biomarker.

METHODS

The study included 26 patients who underwent endoscopic sinus surgery due to CRSwNP and 30 patients who were scheduled to undergo septoplasty due to isolated nasal septum deviation. We performed preoperative Lund-Mackay scoring and preoperative and postoperative SNOT-22 and Modified Lund-Kennedy scoring for the patients. Tissue and serum samples were collected from all patients in surgery and another serum sample was taken from CRSwNP patients at postoperative month 6.

RESULTS

Tissue eosinophil (p < 0.001), preoperative serum (p < 0.001), and tissue (p = 0.002) periostin were significantly higher in the CRSwNP group. We observed a statistically significant positive correlation between tissue eosinophil values and tissue periostin values in CRSwNP patients (p = 0.004). We found a statistically significant positive correlation between the tissue periostin values and postoperative SNOT-22 scores of the CRSwNP group patients (p = 0.005).

CONCLUSION

According to the results of our study, we think that periostin can be used as a biomarker in the prediction, determination of disease severity, and prognosis of CRSwNP. Comprehensive cohort studies with larger patient series are needed to provide more information on the role and effects of periostin in cases of CRSwNP undergoing surgical treatment.

Tobramycin-loaded complexes to prevent and disrupt Pseudomonas aeruginosa biofilms

Carbohydrate-based materials are increasingly investigated for a range of applications spanning from healthcare to advanced functional materials. Synthetic glycopolymers are particularly attractive as they possess low toxicity and immunogenicity and can be used as multivalent ligands to target sugar-binding proteins (lectins). Here, we utilised RAFT polymerisation to synthesize two families of novel diblock copolymers consisting of a glycopolymers block containing either mannopyranose or galactopyranose pendant units, which was elongated with sodium 2-acrylamido-2-methyl-1-propanesulfonate (AMPS) to generate a polyanionic block. The latter enabled complexation of cationic aminoglycoside antibiotic tobramycin through electrostatic interactions (loading efficiency in the 0.5-6.3 wt% range, depending on the copolymer). The resulting drug vectors were characterized by dynamic light scattering, zeta-potential, and transmission electron microscopy. Tobramycin-loaded complexes were tested for their ability to prevent clustering or disrupt biofilm of the Pseudomonas aeruginosa Gram-negative bacterium responsible for a large proportion of nosocomial infection, especially in immunocompromised patients. P. aeruginosa possesses two specific tetrameric carbohydrate-binding adhesins, LecA (PA-IL, galactose/N-acetyl-D-galactosamine-binding) and LecB (PA-IIL, fucose/mannose-binding), and the cell-associated and extracellular adhesin CdrA (Psl/mannose-binding) thus ideally suited for targeted drug delivery using sugar-decorated tobramycin-loaded complexes here developed. Both aliphatic and aromatic linkers were utilised to link the sugar pendant units to the polyacrylamide polymer backbone to assess the effect of the nature of such linkers on bactericidal/bacteriostatic properties of the complexes. Results showed that tobramycin-loaded complexes efficiently suppressed (40 to 60% of inhibition) in vitro biofilm formation in PAO1-L P. aeruginosa and that preferential targeting of PAO1-L biofilm can be achieved using mannosylated glycopolymer-b-AMPS_m.

Synthetic Glycomacromolecules of Defined Valency, Absolute Configuration, and Topology Distinguish between Human Lectins

Carbohydrate-binding proteins (lectins) play vital roles in cell recognition and signaling, including pathogen binding and innate immunity. Thus, targeting lectins, especially those on the surface of immune cells, could advance immunology and drug discovery. Lectins are typically oligomeric; therefore, many of the most potent ligands are multivalent. An effective strategy for lectin targeting is to display multiple copies of a single glycan epitope on a polymer backbone; however, a drawback to such multivalent ligands is they cannot distinguish between lectins that share monosaccharide binding selectivity (e.g., mannose-binding lectins) as they often lack molecular precision. Here, we describe the development of an iterative exponential growth (IEG) synthetic strategy that enables facile access to synthetic glycomacromolecules with precisely defined and tunable sizes up to 22.5 kDa, compositions, topologies, and absolute configurations. Twelve discrete mannosylated "glyco-IEGmers" are synthesized and screened for binding to a panel of mannoside-binding immune lectins (DC-SIGN, DC-SIGNR, MBL, SP-D, langerin, dectin-2, mincle, and DEC-205). In many cases, the glyco-IEGmers had distinct length, stereochemistry, and topology-dependent lectin-binding preferences. To understand these differences, we used molecular dynamics and density functional theory simulations of octameric glyco-IEGmers, which revealed dramatic effects of glyco-IEGmer stereochemistry and topology on solution structure and reveal an interplay between conformational diversity and chiral recognition in selective lectin binding. Ligand function also could be controlled by chemical substitution: by tuning the side chains of glyco-IEGmers that bind DC-SIGN, we could alter their cellular trafficking through alteration of their aggregation state. These results highlight the power of precision synthetic oligomer/polymer synthesis for selective biological targeting, motivating the development of next-generation glycomacromolecules tailored for specific immunological or other therapeutic applications.

Atypical macular hole formation after Anti-VEGF therapy for neovascular age-related macular degeneration: Coincidence or consequence?

INTRODUCTION AND OBJECTIVES

Age-related macular degeneration (AMD) is the primary cause of blindness in developed countries, particularly in older adults. Anti-vascular endothelial growth factor (anti-VEGF) intravitreal injection is the current standard treatment for neovascular form of AMD. Studies reporting macular hole (MH) formation following anti-VEGF treatment are limited, and the exact pathogenesis is still under discussion. With the present study, we aim to analyse the clinical features of eyes developing MH after anti-VEGF therapy for neovascular AMD.

MATERIALS AND METHODS

Patients were treated with intravitreal anti-VEGF agents for at least one year and stable for at least six months. Best-corrected visual acuity (BCVA) and optical coherence tomography findings were evaluated.

RESULTS

Nineteen eyes of 18 patients were included in this study. Patients had an average age of 77.7 years at first visit and eight were female. The average number of injections before the MH formation was four. MH developed after a mean follow-up of 5.1 months after the last injection. Sixteen eyes had (84.2%) had choroidal neovascular membrane without any abnormal vitreomacular traction. Eleven eyes (57.8%) had retinal pigment epithelium detachment (PED), two (10.5%) had an epiretinal membrane (ERM), and one (5.2%) had retinal pigment epithelium (RPE) tear. The mean first and last BCVA was 1.07±0.48 LogMAR (0.3-1.8) and 1.16±0.38 logMAR (0.4-1.8), respectively.

CONCLUSIONS

A macular hole can be observed in AMD patients receiving anti-VEGF therapy. Increased fibrovascular scar tissue due to subretinal fluid resolution, neovascular membrane contraction, and the presence of PED, RPE tear, and ERM may contribute to MH formation.

ECG Intervals on Acute Carbon Monoxide Poisoning

OBJECTIVE

To evaluate the usability of electrocardiography (ECG) intervals in the diagnosis and treatment monitoring of acute carbon monoxide (CO) poisoning.

STUDY DESIGN

An observational study.

PLACE AND DURATION OF STUDY

Department of Emergency Medicine, Kayseri City Hospital, Turkey, from November 2018 to May 2019.

METHODOLOGY

Each of 80 patients for study and control groups were prospectively included. For study group, pre- and post-treatment ECG intervals (P-wave and QRS complex periods, PP, PR, RR, QT, and QTc intervals) and carboxyhemoglobin (COHb) levels of the patients were evaluated. For control group, ECG intervals and COHb levels of the patients during admission to the Emergency Department were evaluated.

RESULTS

As a result of the statistical analysis in which measurements of the study group and control group were compared, a statistically significant difference was found in the following values: pre-treatment group COHb level (p<0.001), PR interval (p=0.046), PP interval (p<0.001), QT interval (p<0.001), QTC interval (p=0.016), RR interval (p<0.001), and post-treatment group COHb level (p<0.001), PR interval (p=0.009), PP interval (p=0.041), QTC interval (p=0.010), and RR interval (p=0.036). QT interval values in the post-treatment group were similar to those of the control group (p=0.342). In the ROC analysis where the diagnostic performance of ECG intervals was evaluated, the area under the curve (AUC) scale was between 0.29 and 0.62.

CONCLUSION

ECG intervals do not provide as much benefit as COHb measurement in the diagnosis of acute CO poisoning. However, the QT interval is a useful ECG interval in the treatment monitoring of acute CO poisoning. Key Words: Acute carbonmonoxide poisoning, ECG interval, QT interval, Emergency Department.

Factors Affecting Cecal Intubation Time in Colonoscopy: Impact of Obesity

Objective

This study aims to determine the factors that prolong cecal intubation time (CIT) and determine the effect of obesity on CIT measured using multiple indexes.

Methods

Patients who underwent elective colonoscopy between July 10, 2020, and January 20, 2021, were evaluated in this prospective observational study. Age, gender, constipation, bowel preparation, presence of diverticulosis, previous surgery history, auxiliary maneuver and additional analgesic requirement, cecum intubation length (CL) and obesity indices [body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR)] were analyzed. Factors affecting CIT were assessed by both univariate and multivariate logistic regression (LR) analyses.

Results

A total of 512 patients were analyzed. Mean CIT was 5.6 ± 1.6 min, and median CIT was 5.17 min. The CIT median was ≤5.17 min in 264 (51.5%) of the patients, and the CIT median was >5.17 min in 248 (48.5%). In the univariate LR results, young age, constipation, poor bowel preparation, increased CL, additional analgesic requirement, low WHtR, and low BMI (<25 kg/m2) were the factors that prolonged CIT (p <0.05). In the multivariate LR analysis results, WHtR >0.5 and BMI >30 kg/m2 were found to be independent factors that decrease CIT [OR: 0.01 (0.01 0.03) p <0.001; OR: 0.28 (0.13 0.57) p <0.001].

Conclusion

Younger age, low WHtR, low BMI, increased CL, constipation, inadequate bowel preparation, and the use of extra analgesics were found to be associated with longer CIT. When all factors were evaluated together, obesity measured by only WHtR (>0.5) and BMI (>30 kg/m2) were the best predictors of decreased CIT.

Combining Inducible Lectin Expression and Magnetic Glyconanoparticles for the Selective Isolation of Bacteria from Mixed Populations

The selective isolation of bacteria from mixed populations has been investigated in varied applications ranging from differential pathogen identification in medical diagnostics and food safety to the monitoring of microbial stress dynamics in industrial bioreactors. Selective isolation techniques are generally limited to the confinement of small populations in defined locations, may be unable to target specific bacteria, or rely on immunomagnetic separation, which is not universally applicable. In this proof-of-concept work, we describe a novel strategy combining inducible bacterial lectin expression with magnetic glyconanoparticles (MGNPs) as a platform technology to enable selective bacterial isolation from cocultures. An inducible mutant of the type 1 fimbriae, displaying the mannose-specific lectin FimH, was constructed in Escherichia coli allowing for "on-demand" glycan-binding protein presentation following external chemical stimulation. Binding to glycopolymers was only observed upon fimbrial induction and was specific for mannosylated materials. A library of MGNPs was produced via the grafting of well-defined catechol-terminal glycopolymers prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization to magnetic nanoparticles. Thermal analysis revealed high functionalization (≥85% polymer by weight). Delivery of MGNPs to cocultures of fluorescently labeled bacteria followed by magnetic extraction resulted in efficient depletion of type 1 fimbriated target cells from wild-type or afimbriate E. coli. Extraction efficiency was found to be dependent on the molecular weight of the glycopolymers utilized to engineer the nanoparticles, with MGNPs decorated with shorter Dopa-(ManAA)₅₀ mannosylated glycopolymers found to perform better than those assembled from a longer Dopa-(ManAA)₂₀₀ analogue. The extraction efficiency of fimbriated E. coli was also improved when the counterpart strain did not harbor the genetic apparatus for the expression of the type 1 fimbriae. Overall, this work suggests that the modulation of the genetic apparatus encoding bacterial surface-associated lectins coupled with capture through MGNPs could be a versatile tool for the extraction of bacteria from mixed populations.

Hyaluronan (HA)-inspired glycopolymers as molecular tools for studying HA functions

Hyaluronic acid (HA), the only non-sulphated glycosaminoglycan, serves numerous structural and biological functions in the human body, from providing viscoelasticity in tissues to creating hydrated environments for cell migration and proliferation. HA is also involved in the regulation of morphogenesis, inflammation and tumorigenesis through interactions with specific HA-binding proteins. Whilst the physicochemical and biological properties of HA have been widely studied for decades, the exact mechanisms by which HA exerts its multiple functions are not completely understood. Glycopolymers offer a simple and precise synthetic platform for the preparation of glycan analogues, being an alternative to the demanding synthetic chemical glycosylation. A library of homo, statistical and alternating HA glycopolymers were synthesised by reversible addition-fragmentation chain transfer polymerisation and post-modification utilising copper alkyne-azide cycloaddition to graft orthogonal pendant HA monosaccharides (N-acetyl glucosamine: GlcNAc and glucuronic acid: GlcA) onto the polymer. Using surface plasmon resonance, the binding of the glycopolymers to known HA-binding peptides and proteins (CD44, hyaluronidase) was assessed and compared to carbohydrate-binding proteins (lectins). These studies revealed potential structure-binding relationships between HA monosaccharides and HA receptors and novel HA binders, such as Dectin-1 and DEC-205 lectins. The inhibitory effect of HA glycopolymers on hyaluronidase (HAase) activity was also investigated suggesting GlcNAc- and GlcA-based glycopolymers as potential HAase inhibitors.

One-pot synthesis of amphiphilic multiblock poly(2-oxazoline)s via para-fluoro-thiol click reactions

A clickable initiator, pentafluoro benzyl bromide, has been investigated for the cationic ring opening polymerization of poly(2-oxazolines).

Self-Assembled Multi- and Single-Chain Glyconanoparticles and Their Lectin Recognition

In this work, we describe the physicochemical characterization of amphiphilic glycopolymers synthesized via copper(0)-mediated reversible-deactivation radical polymerization (Cu-RDRP). Depending on the chemical composition of the polymer, these glycopolymers are able to form multi-chain or single-chain polymeric nanoparticles. The folding of these polymers is first of all driven by the amphiphilicity of the glycopolymers and furthermore by the supramolecular formation of helical supramolecular stacks of benzene-1,3,5-tricarboxamides (BTAs) stabilized by threefold hydrogen bonding. The obtained polymeric nanoparticles were subsequently evaluated for their lectin-binding affinity toward a series of mannose- and galactose-binding lectins via surface plasmon resonance. We found that addition of 2-ethylhexyl acrylate to the polymer composition results in compact particles, which translates to a reduction in binding affinity, whereas with the addition of BTAs, the relation between the nature of the particle and the binding ability system becomes more unpredictable.