Transcatheter Closure of Residual and Iatrogenic Ventricular Septal Defects: Tertiary Center Experience and Outcome

Residual or iatrogenic ventricular septal defects (VSDs) may result in significant hemodynamic effect. This study aimed to review our center experience in transcatheter closure of post-surgical and post-intervention residual and iatrogenic VSDs and to report on their 12-month long-term outcome. All patients who underwent transcatheter closure of residual/iatrogenic VSDs after surgical or transcatheter CHD interventions between January-2015 and January-2020 were included. Patients' medical records were reviewed and analyzed. Twenty-three patients with a mean age of 14.3 ± 8.8 years were included. The VSD was residual in 18 (78.3%) patients and iatrogenic in 5 (21.7%) patients, post-operative in 19 (82.6%) patients and post-transcatheter in 4 (17.4%) patients. The VSD site was peri-membranous in 9 (39.1%) patients, high-muscular in 6 (26.1%) patients, mid-muscular in 4 (17.4%) patients, and Gerbode shunt in 4 (17.4%) patients. The QP/QS ratio was 2.5 ± 0.7, and the VSD diameter was 6.1 ± 2.1 mm. Most, 16 (71.43%) patients underwent antegrade device deployment, and 7 (28.57%) patients underwent retrograde transaortic device deployment with 3 (13.0%) patients required two devices. Amplatzer™ Muscular VSD devices were used in 16 (69.6%) patients, Amplatzer™ Duct occlude-I devices were used in 4 (17.4%) patients, and Amplatzer™ Duct Occluder-II devices were used in 3 (13.0%) patients with a mean device size of 8.8 ± 2.8 mm. Procedural and fluoroscopy times were 55.1 ± 16.2 and 16.3 ± 4.0 min respectively. During follow-up (23.3 ± 15.9 months), no patient required re-intervention or exhibited mortality. Transcatheter closure of post-operative and post-intervention residual/iatrogenic VSDs represents a safe, feasible, and effective therapeutic approach.

Commiphora myrrha (Nees) Engl. resin extracts induce phase-I cytochrome P450 2C8, 2C9, 2C19, and 3A4 isoenzyme expressions in human hepatocellular carcinoma (HepG2) cells

Commiphora myrrha (Nees) Engl. (C. myrrha) resin is the most Middle Eastern herbal medicine used against numerous diseases. After being decocted or macerated, this resin is widely consumed among Saudi Arabian patients who are already under prescribed medication. Despite its popularity, no studies have been reported on potential modulation effects of these resin extracts on drug metabolism. Therefore, we studied C. myrrha resin extracts on the expression of cytochrome P450 (CYP) drug-metabolizing isoenzyme in human hepatocellular carcinoma cell line HepG2. The C. myrrha extracts were prepared by sonication and boiling, resembling the most popular traditional preparations of maceration and decoction, respectively. Both boiled and sonicated aqueous extracts were fingerprinted using high-performance liquid chromatography equipped with ultra-violet detector (HPLC-UVD). The viability of HepG2 cells treated with these aqueous extracts was determined using CellTiter-Glo® assay in order to select the efficient and non-toxic resin extract concentrations for phase-I metabolic CYP isoenzyme expression analysis. The isoenzyme gene and protein expression levels of CYP 2C8, 2C9, 2C19, and 3A4 were assessed using reverse transcription-quantitative polymerase chain reaction and Western blot technologies. The HPLC-UVD fingerprinting revealed different chromatograms for C. myrrha boiled and sonicated aqueous extracts. Both aqueous extracts were toxic to HepG2 cells when tested at concentrations exceeding 150 µg/ml of the dry crude extract. The CYP 2C8, 2C9, and 2C19 mRNA expression levels increased up to 4.0-fold in HepG2 cells treated with either boiled or sonicated C. myrrha aqueous extracts tested between 1 and 30 µg/ml, as compared with the untreated cells. However, CYP3A4 mRNA expression level exceeded the 2.0-fold cutoff when the cells were exposed to 30 µg/ml of C. myrrha extracts. The up-regulation of CYP mRNA expression levels induced by both boiled and sonicated C. myrrha aqueous extracts was confirmed at the CYP protein expression levels. In conclusion, both sonicated and boiled C. myrrha aqueous extracts modulate CYP 2C8, 2C9, 2C19, and 3A4 gene expression at clinically-relevant concentrations regardless of preparation methods. Further in vitro and in vivo experiments are required for CYP isoenzyme activity assessment and the establishment of herb-drug interaction profile for these traditional medicinal resin extracts.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Analysis of chronic kidney disease patients by targeted next-generation sequencing identifies novel variants in kidney-related genes

Despite the enormous economic and societal burden of chronic kidney disease (CKD), its pathogenesis remains elusive, impeding specific diagnosis and targeted therapy. Herein, we sought to elucidate the genetic causes of end-stage renal disease (ESRD) and identify genetic variants associated with CKD and related traits in Saudi kidney disease patients. We applied a genetic testing approach using a targeted next-generation sequencing gene panel including 102 genes causative or associated with CKD. A total of 1,098 Saudi participants were recruited for the study, including 534 patients with ESRD and 564 healthy controls. The pre-validated NGS panel was utilized to screen for genetic variants, and then, statistical analysis was conducted to test for associations. The NGS panel revealed 7,225 variants in 102 sequenced genes. Cases had a significantly higher number of confirmed pathogenic variants as classified by the ClinVar database than controls (i.e., individuals with at least one allele of a confirmed pathogenic variant that is associated with CKD; 279 (0.52) vs. 258 (0.45); p-value = 0.03). A total of 13 genetic variants were found to be significantly associated with ESRD in PLCE1, CLCN5, ATP6V1B1, LAMB2, INVS, FRAS1, C5orf42, SLC12A3, COL4A6, SLC3A1, RET, WNK1, and BICC1, including four novel variants that were not previously reported in any other population. Furthermore, studies are necessary to validate these associations in a larger sample size and among individuals of different ethnic groups.

A 2-Year-Old Boy Who Developed an Aortoesophageal Fistula After Swallowing a Button Battery, Managed Using a Novel Procedure with Vascular Plug Device as a Bridge to Definitive Surgical Repair

Patient: Male, 2-year-old

Final Diagnosis: Aortoesophageal fistula

Symptoms: Esophageal foreign body • gastrointestinal bleeding

Medication: —

Clinical Procedure: —

Specialty: Gastroenterology and Hepatology • Pediatrics and Neonatology

Can Fasting Blood Sugar be Used as an Indicator of Long-Term Diabetic Control Instead of Estimated Average Glucose?

BACKGROUND

Diabetes mellitus is a chronic illness that is a worldwide issue. HbA1c has been used to monitor glycemic control in patients with diabetes for many years. Although HbA1c measurement is needed for calculating estimated average blood glucose (eAG), it is now recommended that eAG is used instead of HbA1c for expression of blood glucose control and communication with patients and health care providers. This study, investigated fasting blood glucose (FBS) as an indicator of overall chronic blood sugar control by assessing the correlation between FBS with eAG derived from HbA1c.

METHODS

The blood samples for HbA1c assay were collected in EDTA tubes and were analyzed by an HPLC analyzer (G8 Tosoh, Japan). Blood samples for FBS were collected in serum separator tubes, transported, and centrifuged for 15 minutes at 3,000 g. FBS levels were determined in serum samples with the enzymatic hexokinase method by a clinical chemistry analyzer (Architect 8000, Abbott, USA).

RESULTS

Statistical analysis was performed on 1,740 patients with type 2 diabetes mellitus with HbA1c levels above 6.5 mmol/L. The difference between FBS (9.3 ± 3.7 mmol/L) and eAG (11.14 ± 2.7 mmol/L) was statistically signif-icant (p < 0.0001). The correlation coefficient between FBS and eAG was r = 0.65 (95% CI; 0.62 - 0.69), with a p-value < 0.0001. While the correlation coefficient between FBS and eAG at HbA1c < 6.5% was r = 0.251 (95% CI, 0.16 - 0.34), with a significant p-value of < 0.00001. The combined data, standard deviation (SD), median, and interquartile range of eAG and FBS for all of the diabetic groups (n = 2,315), were 10.1 ± 3.00 mmol/L, 9.5 mmol/L, and 7.75 - 12.03 mmol/L for eAG, respectively. Similarly, these values were 8.5 ± 3.6 mmol/L, 7.5 mmol/L, and 6.0 - 10.00 mmol/L for FBS, respectively.

CONCLUSIONS

We concluded that there is a moderate and significant positive correlation between fasting blood sugar and the estimated average blood glucose derived from HbA1c. Although FBS might be helpful for daily monitoring of diabetes. Further studies must be conducted to provide solid results to support that FBS and its derived variable eAG can replace HbA1c as an indicator of long-term overall control of T2DM patients.

Cardiac Catheterisation Interventions in Neonates and Infants Less Than Three Months

Introduction

Pediatric cardiac catheterization interventions become an established way of care for selected patients with congenital heart diseases. Cardiac catheterization for neonates and small infants can be challenging. The indications for diagnostic cardiac catheterization have decreased with the advent of advanced non-invasive imaging modalities.

Patients and method

Between June 2012 and July 2017 patients less than three months who had cardiac catheterization in two centers were reviewed.

Results

During the study period, 174 patients underwent interventional cardiac catheterization,83.3% of them had CHD with two-ventricle circulation and 29 patients (16.7%) had single ventricle pathophysiology. Procedures include diagnostic cath, BAS, balloon pulmonary and aortic valvuloplasty, coarctation angioplasty, and stenting procedures. The vascular access depends upon the type of procedure. All except one had general anesthesia. ICU admission was required on 106 patients (62%). Patients were divided according to the type of cardiac lesion (single versus biventricular pathology) as well as according to the type of intervention (stenting and non-stenting procedures). Comparing these groups revealed that: stent procedures and procedures for patients with single ventricle pathologies were performed at an earlier age, with more contrast, fluoro and procedure time than for non-stent procedures and procedures for patients with biventricular pathologies. Complications include transient arrhythmias in most patients, perforation of the RVOT in one and lower limb hypoperfusion in 12 patients. ICU complications include low cardiac output symptoms (LCOS) in 10 (7%), and sepsis in 8. No intra-procedure mortality. The overall survival was 94%. Ten patients died, with one early and 9 late mortality. 60% of the dead patients had PDA stenting. Reintervention varies according to the patient's diagnosis.

Conclusion

Cardiac catheterization intervention an important modality in the management of neonates and infants with critical CHD. Well planned procedures and team expertise are essential. Stenting procedures and procedures for patients with single ventricles carries higher morbidity and mortality.

Attitudes and practices of physicians toward law enforcement on dispensing antibiotics without prescription antibiotics: Findings from a cross-sectional survey

Background

The government of Saudi Arabia implemented a law to enforce the law and regulations prohibiting the dispensing of antibiotics without a prescription, and studies have been conducted to assess the impact of such a law in Saudi Arabia. However, the extent to which law enforcement has changed the perceptions and attitudes of health care professionals, mainly physicians, toward antibiotic resistance is unknown in Saudi Arabia.

Material and Methods

A cross-sectional study was conducted in Riyad, Saudi Arabia, on 378 physicians. These physicians were mainly working in primary care centers. An online questionnaire was sent to the physicians, and it consisted of 35 items and was divided into four sections: 6 items were on sociodemographic characteristics of participants; 13 items were on the knowledge of physicians about antibiotic resistance; 8 items were on the attitude the physicians toward enforcement law, and the final 8 items were on the attitude the patients toward enforcement law in an outpatient setting.

Results

Around 90% of the physicians acknowledged that physicians should stop prescribing antibiotics without indication. About 29.1 % of the physicians agreed, and 56.3% showed strong agreement that law enforcement is for the patient's benefit. Similarly, 33.6% agreed, and 50.8% strongly agreed that law enforcement limits the resistance of bacteria. Around 24.3% of the patients disagreed, and 23% strongly disagreed that law enforcement does not affect anything. Around one-third of the physicians (34.4%) agreed, and 23.5% strongly agreed that the new regulation of law enforcement of antibiotic prescription increases public awareness regarding the misuse of antibiotics.

Conclusion

It seems that law enforcement has impacted the knowledge and attitude of physicians as they agree with law enforcement and its associated benefits for patients. They also acknowledged that law enforcement could limit the resistance to bacteria. However, not all physicians agree that law enforcement has an effect on anything, and new regulation of antibiotic prescription law increases public awareness regarding the misuse of antibiotics.

Surgical Management of a Right Coronary Artery Fistula After Failed Transcatheter Closure: A Case Report

A coronary artery fistula (CAF) is an abnormal communication between a coronary artery and a great vessel or cardiac chamber. CAFs are very rare and are mostly of congenital origin, but they can also be acquired. Patients are usually asymptomatic since the majority of CAFs are small in size; hence, most cases are usually discovered incidentally during routine angiographic investigations. Moderate or large CAFs can be symptomatic, causing angina pectoris due to coronary steal phenomenon, and can carry a high risk of serious complications such as myocardial infarction, heart failure, or even sudden cardiac death. Consequently, prompt management with the appropriate choice of intervention - surgical versus transcatheter closure - is essential to prevent such complications. We present a case of a 52-year-old male patient with a right coronary artery-coronary sinus fistula managed with surgical closure.

Knowledge of kindergarten and elementary schools’ teachers regarding attention deficit hyperactivity disorder

Background

Attention deficit hyperactivity disorder (ADHD) is one of the most common mental disorders that manifest among children. Despite the fact that the teacher's role is essential in the assessment and management of pupils with ADHD and the recommendation of participation of teachers for the success and efficiency of diagnoses and treatment, the vast majority of teachers have neither understanding nor knowledge of ADHD.

Objectives

The current study explores the kindergarten and elementary school teachers’ knowledge regarding early detection and management of ADHD.

Methods

Cross sectional survey using stratified random sampling technique was carried out in governmental and private elementary and kindergarten schools in four cities of Qassim region, Saudi Arabia.

Results

The study included 1095 teachers, 711 (59.3%) did not get information about ADHD during undergraduate studies. Teachers’ overall ADHD knowledge mean was 21.7 + 5.5 out of 38 marks. Teachers with high qualification degree and kindergarten specialty scored 56.4% and 60.2%, respectively. Teachers who attended conferences related to ADHD scored 64.5%, while teachers who read about ADHD or have been ever asked to diagnose/teach an ADHD student had 59.4% and 62.1%, respectively. The sources for those who got their information through reading were statistically significant in overall knowledge, general knowledge and treatment dimensions. As scientific studies and books were the highest with percentage of 24.6% and 23.3%, respectively, 4% and 3.6%, respectively, 3% and 3%, respectively. The level of ADHD knowledge perception showed that 76% of teachers were knowledgeable in relation to overall ADHD perception.

Conclusion

Teachers who have higher qualifications or training in identifying ADHD children scored higher in our study.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Plasmin Inhibitor in Health and Diabetes: Role of the Protein as a Therapeutic Target

The vascular obstructive thrombus is composed of a mesh of fibrin fibers with blood cells trapped in these networks. Enhanced fibrin clot formation and/or suppression of fibrinolysis are associated with an increased risk of vascular occlusive events. Inhibitors of coagulation factors and activators of plasminogen have been clinically used to limit fibrin network formation and enhance lysis. While these agents are effective at reducing vascular occlusion, they carry a significant risk of bleeding complications. Fibrin clot lysis, essential for normal hemostasis, is controlled by several factors including the incorporation of antifibrinolytic proteins into the clot. Plasmin inhibitor (PI), a key antifibrinolytic protein, is cross-linked into fibrin networks with higher concentrations of PI documented in fibrin clots and plasma from high vascular risk individuals. This review is focused on exploring PI as a target for the prevention and treatment of vascular occlusive disease. We first discuss the relationship between the PI structure and antifibrinolytic activity, followed by describing the function of the protein in normal physiology and its role in pathological vascular thrombosis. Subsequently, we describe in detail the potential use of PI as a therapeutic target, including the array of methods employed for the modulation of protein activity. Effective and safe inhibition of PI may prove to be an alternative and specific way to reduce vascular thrombotic events while keeping bleeding risk to a minimum. Key Points Plasmin inhibitor (PI) is a key protein that inhibits fibrinolysis and stabilizes the fibrin network.This review is focused on discussing mechanistic pathways for PI action, role of the molecule in disease states, and potential use as a therapeutic target.

Transcatheter Closure of Residual and Iatrogenic Ventricular Septal Defects: Tertiary Center Experience and Outcome

Aim

This study aimed to review our center experience in transcatheter closure of post-surgical and post-intervention residual and iatrogenic VSDs and to report on their 12-month long-term outcome.

Methods

All patients who underwent transcatheter closure of residual ventricular septal defects (R-VSDs) and iatrogenic ventricular septal defects (I-VSDs) after either surgical corrections or transcatheter interventions for any congenital heart disease (CHD) between January 2015 and January 2020 were included in the study. Patients' medical records were reviewed and analyzed.

Results

Twenty-three patients with a mean age of 14.3 ± 8.8 years, a mean weight of 36.2 ± 20.4 Kg, and a mean body surface area of 1.18 ± 0.36 m2 were included. Thirteen (56.5%) patients were males. The VSD was residual in 18 (78.3%) patients and iatrogenic in 5 (21.7%) patients, post-operative in 19 (82.6%) patients and post-transcatheter in 4 (17.4%) patients. The remaining VSD site was peri-membranous in 9 (39.1%) patients, high-muscular in 6 (26.1%) patients, mid-muscular in 4 (17.4%) patients, and Gerbode shunt in 4 (17.4%) patients. The QP/QS ratio was 2.5 ± 0.7, and the VSD diameter was 6.1±2.1 mm with a VSD-aorta rim of 5.4 ± 2.0 mm. Most, 16 (71.43%) patients underwent antegrade device deployment, and 7 (28.57%) patients underwent retrograde transaortic device deployment, with only 3 (13.0%) patients required two devices/patient. Amplatzer™ Muscular VSD devices were used in 16 (69.6%) patients, Amplatzer™ Duct occlude-I devices were used in 4 (17.4%) patients, and Amplatzer™ Duct Occluder-II devices were used in 3 (13.0%) patients with a mean device size of 8.8 ± 2.8 mm. The mean procedural time was 55.1 ± 16.2 minutes, fluoroscopy time was 16.3 ± 4.0 minutes, and the contrast used was 33.8 ± 10.9 ml. Concomitant balloon pulmonary valvuloplasty was done at the same catheterization set in 2 (8.7%) patients. Acute procedural success, satisfactory immediate were achieved in all patients. During follow-up (23.3 ± 15.9 months), no patient required re-intervention or exhibited mortality.

Conclusions

Transcatheter closure of post-operative, and post-intervention residual and iatrogenic VSDs represents an attractive therapeutic approach. This approach is safe, feasible, effective, and less invasive alternative treatment option for such remaining VSDs.

P272 The need for vasodilators use prior to transradial cardiac catheterization in high volume cardiac center

Funding Acknowledgements

This study received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors

Background

Radial artery spasm (RAS) is one of the most common complication encountered by operators while performing trans-radial artery cardiac catheterization. Due to the technological advances in recent years and the increase number of experts in high volume centers, the prophylactic use of vasodilators may be unnecessary. To date, there are no clear recommendations for using these vasodilators and when to be used in day to day practice. Basically, It depends on operators discretion and hospital protocol. Therefore, further research in this area is warranted due to the conflicting findings of the prior studies.

purpose

To evaluate the need of using prophylactic vasodilators prior to trans-radial approach in high volume cardiac center and to identify factors associated with the development of RAS.

Methods

It is a prospective, randomized, double blind and placebo-controlled trial conducted in a single high volume cardiac center in Saudi Arabia from July to November 2017. Patients who met the inclusion criteria were randomized to either a cocktail vasodilators (nitroglycerin and verapamil) or matching placebo (normal saline) in 1:1 ratio. Subjective definition of RAS was utilized, consistent with previous studies. The primary outcome is the development of RAS in both groups. The secondary outcome is identifying the factors associated with the development of RAS. The calculated sample size is 315 patients. Data analysis was performed using SPSS 20 and STATA 15 softwares. Multiple stepwise logistic regression was used to examine the association between the study variables and incidence of RAS.

Results

A total of 490 patients were randomized (244 in placebo and 246 in treatment groups). There were no differences in the baseline demographic and clinical characteristics between both groups. Significantly, higher proportion of patients on the placebo group had RAS compared to those on the treatment group (23% vs 11%; p = 0.001). After controlling for the other factors, patients on the treatment were less likely to develop RAS than those on the placebo (OR= 0.32; p &lt;0.001). The independent risk factors associated with the occurrence of RAS are: female gender (OR= 6.18; p &lt;0.001), multiple puncture attempts (OR= 2.83; p = 0.003), current smoking (OR= 3.02; p =0.03) and using dihydropyridine calcium channel blockers (OR= 4.60; p &lt;0.001). We did not find a significant relationship between operators’ level of experience and the occurrence of RAS.

Conclusion

The use of cocktail vasodilators reduces the incidence of RAS regardless to the hospital volume and operators experience. Further studies on factors associated with RAS is warranted.

Transcatheter Mitral Valve Repair Technique in Specific Severe Mitral Regurgitation: Tips, Tricks, and Outcomes

Background

In specific patients with severe mitral regurgitation (MR), mitral valve (MV) pathology is unique and requires creative transcatheter repair techniques. This study aimed to evaluate the feasibility and safety of a new transcatheter MV repair technique, using occluder devices in symptomatic high-surgical-risk patients with severe MR, either due to MV leaflet (MVL) perforations or due to post-clips residual MR, and to report on their 6-month outcomes.

Methods

The study enrolled all high-risk patients with severe MR due to MVL perforations and post-clips residual MR who underwent transcatheter MV repair using occluder devices, from November 2016 to August 2019.

Results

The study enrolled 16 patients; 9 (56.25%) with MVL perforations and 7 (43.75%) with post-MitraClip (Abbott Laboratories, Abbott Park, Illinois) residual MR, with a mean age of 55.75 ± 16.69 years. Mean perforation/jet diameters were 5.75 ± 1.67 and 6.5 ± 1.93 mm, and the mean 3D-vena contracta area was 0.54 ± 0.14 cm². Perforations were crossed retrograde (transaortic in 7 [43.75%] patients and transapical in 2 [12.5%] patients), and post-MitraClip devices residual jets were crossed antegrade (transvenous/transseptal). Six (37.5%) patients required arteriovenous loop formation for device deployment, that was antegrade transvenous/transseptal in 13 (81.25%) patients and retrograde transapical in 3 (18.75%) patients. Devices used were Amplatzer-ASO in 10 (62.5%) patients and Amplatzer-VP-II in 6 (37.5%) patients. Mean procedural and fluoroscopy times were 55.13 ± 16.24 and 16.25 ± 4.03 ​minutes, respectively. Patients passed successfully, without MV gradient change or device-related complications.

Conclusions

Transcatheter MV repair of MVL perforations/post-clips residual MR is a new, feasible, and safe technique for high-surgical-risk patients.

Achillea fragrantissima (Forssk.) Sch.Bip Flower Dichloromethane Extract Exerts Anti-Proliferative and Pro-Apoptotic Properties in Human Triple-Negative Breast Cancer (MDA-MB-231) Cells: In Vitro and In Silico Studies

The aggressive triple-negative breast cancer (TNBC) is a challenging disease due to the absence of tailored therapy. The search for new therapies involves intensive research focusing on natural sources. Achillea fragrantissima (A. fragrantissima) is a traditional medicine from the Middle East region. Various solvent extracts from different A. fragrantissima plant parts, including flowers, leaves, and roots, were tested on TNBC MDA-MB-231 cells. Using liquid chromatography, the fingerprinting revealed rich and diverse compositions for A. fragrantissima plant parts using polar to non-polar solvent extracts indicating possible differences in bioactivities. Using the CellTiter-Glo™ viability assay, the half-maximal inhibitory concentration (IC₅₀) values were determined for each extract and ranged from 32.4 to 161.7 µg/mL. The A. fragrantissima flower dichloromethane extract had the lowest mean IC₅₀ value and was chosen for further investigation. Upon treatment with increasing A. fragrantissima flower dichloromethane extract concentrations, the MDA-MB-231 cells displayed, in a dose-dependent manner, enhanced morphological and biochemical hallmarks of apoptosis, including cell shrinkage, phosphatidylserine exposure, caspase activity, and mitochondrial outer membrane permeabilization, assessed using phase-contrast microscopy, fluorescence-activated single-cell sorting analysis, Image-iT™ live caspase, and mitochondrial transition pore opening activity, respectively. Anticancer target prediction and molecular docking studies revealed the inhibitory activity of a few A. fragrantissima flower dichloromethane extract-derived metabolites against carbonic anhydrase IX, an enzyme reported for its anti-apoptotic properties. In conclusion, these findings suggest promising therapeutic values of the A. fragrantissima flower dichloromethane extract against TNBC development.

Use of Affimer technology for inhibition of α2-antiplasmin and enhancement of fibrinolysis

ABSTRACT

Hypofibrinolysis is a documented abnormality in conditions with high risk of vascular occlusion. A key inhibitor of fibrinolysis is α2-antiplasmin (α2AP), and we hypothesize that the Affimer technology, comprising small conformational proteins with 2 9-amino-acid variable regions, can be used to modulate α2AP activity and facilitate fibrinolysis. Using a phage display system, a library of Affimers was screened against α2AP. A total of 28 α2AP-specific Affimers were isolated, of which 1, termed Affimer A11, inhibited protein function and enhanced fibrinolysis. Affimer A11 displayed a monomeric form and consistently reduced the lysis time of clots made from plasma samples of individuals with type 2 diabetes mellitus (n = 15; from 150.8 ± 100.9 to 109.8 ± 104.8 minutes) and those with cardiovascular disease (n = 15; 117.6 ± 40.6 to 79.7 ± 33.3 minutes; P < .01 for both groups). The effects of A11 on fibrinolysis were maintained when clots were made from whole blood samples. Mechanistic studies demonstrated that A11 did not affect clot structure or interfere with the incorporation of α2AP into fibrin networks but significantly enhanced plasmin activity and accelerated plasmin generation. Affimer A11 reduced α2AP binding to plasmin(ogen), whereas molecular modeling demonstrated interactions with α2AP in an area responsible for binding to plasminogen, explaining the effects on both plasmin activity and generation. Affimer A11, at 0.15 to 0.60 mg/mL, had the ability to bind 70% to 90% of plasma α2AP. In conclusion, we demonstrate that Affimers are viable tools for inhibiting α2AP function and facilitating fibrinolysis, making them potential future therapeutic agents to reduce thrombosis risk.