Predictors of Acute Compartment Syndrome in Patients With Forearm Fractures: A Systematic Review

Acute compartment syndrome (ACS) is a critical orthopedic and traumatology emergency arising from elevated pressure within a confined osteofascial compartment, leading to compromised blood circulation and tissue ischemia. This systematic review aims to comprehensively identify and analyze the most predictable risk factors associated with ACS development in patients with forearm fractures. Published articles on ACS were meticulously searched and evaluated on reputable medical databases such as PubMed. The keywords "risk factors associated with the ACS in patients who have sustained forearm fractures"were used to create the search syntax on various databases. Data were gathered on raw prevalence, population under study, and methodology. A total of 10 articles that met the search criteria were identified and included in this review with a total of more than 300,000 patients across the studies. Fracture-related ACS was the most common, followed by soft tissue damage among patients with forearm fractures. This review underscores fractures as primary ACS catalysts, along with the role of soft tissue trauma. Meticulous consideration of these risk factors can enhance clinical decision-making, early detection, and intervention, improving patient outcomes and care quality.

Acute Care Surgery: Navigating Recent Developments, Protocols, and Challenges in the Comprehensive Management of Surgical Emergencies

Acute care surgery (ACS) is a crucial medical field that specifically deals with the rapid treatment of surgical emergencies. This investigation encompasses the most recent progress, procedures, and obstacles in ACS, utilizing various sources such as scholarly articles, clinical trials, and expert statements. The development of ACS as a specialized field is a significant area of concentration, particularly emphasizing its contribution to improving patient care. An examination is conducted on the efficacy of contemporary triage systems and prompt response mechanisms, specifically in diminishing the incidence of illness and death rates associated with illnesses such as trauma, acute appendicitis, and obstructed viscera. The emphasis is placed on the surgical protocols and principles that form the basis of ACS. Examining regional and international approaches provides insight into the distinctions and commonalities in surgical techniques. An assessment is conducted to determine the effects of the transition to minimally invasive procedures on patient outcomes, recuperation periods, and healthcare expenses. The assessment also examines the logistical obstacles that ACS encounters, such as resource allocation and managing diverse teams. The examination focuses on the delicate equilibrium between prompt decision-making and care grounded in evidence. It also evaluates the possible contribution of technical breakthroughs such as telemedicine and AI to improving patient care and overcoming current obstacles. The topic of training and education for surgeons in ACS is of utmost importance and requires careful consideration. The evaluation evaluates the sufficiency of existing educational frameworks and the necessity of specific training to equip surgeons for the requirements of ACS. This analysis explores the current discourse surrounding the standardization of ACS training, considering its potential ramifications for the future of surgical procedures. Exploring ethical and legal problems in ACS also includes situations when prompt decision-making may clash with patient autonomy and informed consent. The significance of proficient communication with patients and their families during emergency surgical scenarios is underscored, emphasizing the necessity for ethical awareness and interpersonal aptitude. The investigation of ACS demonstrates its dynamic character, signifying notable advancements while recognizing enduring obstacles. Continual research, interdisciplinary collaboration, and policy adjustments are necessary to improve ACS procedures. This thorough investigation offers valuable insights for professionals and researchers, facilitating future progress in managing surgical crises.

Early Major Adverse Cardiovascular Event in a Patient With Chronic Kidney Disease: A Case Report

Acute coronary syndrome (ACS) is common in people with chronic kidney disease (CKD) and is linked to poor short- and long-term outcomes. The diagnosis of myocardial infarction is challenging in patients with CKD as they have baseline elevated troponin levels. To date, there are no widely accepted guidelines to suggest what is a clinically significant change in troponin levels in these patients. We report a case of a patient with CKD who presented with chest pain to the emergency department (ED). His baseline troponin was high; however, the delta change was 11%. He was discharged from the ED for outpatient follow-up, but within 36 hours, he had significant ST elevation myocardial infarction (STEMI) with unstable hemodynamics and acute heart failure requiring urgent intubation and coronary revascularization. This case highlights the gap in clinical knowledge and practice in a relatively not uncommon presentation in emergency departments.

Outcomes of Hospitalized Patients With Fecal Occult Positive Stool Prior to Cardiac Catheterization in Acute Coronary Syndrome (ACS)

Introduction Cardiac catheterization is an essential component of patient care in Acute Coronary Syndrome (ACS). Fecal occult blood testing (FOBT) has been used in the inpatient setting to evaluate the risk of bleeding with dual anti-platelet therapy prior to cardiac catheterization although no guidelines exist for this indication and FOBT testing in the inpatient setting is not recommended for evaluation of GI blood loss. We sought to assess the outcomes of patients with fecal occult positive stool prior to cardiac catheterization compared to those that did not undergo FOBT during admission for non-ST-elevation myocardial infarction (NSTEMI). Methods We identified patients between 18 and 90 years old with admission for NSTEMI in the Trinetx Research Network from January 1, 2019 to December 31, 2020. Patients were then divided into those who had an FOBT prior to cardiac catheterization and those that did not have an FOBT. We compared all-cause mortality, bleeding, troponin levels, and length of stay between propensity-matched (PSM) pairs of patients. Results We identified 46,349 that met inclusion criteria, of which 1,728 had an FOBT (3.7%) and 44,621 (96.3%) had no FOBT prior to cardiac catheterization. Patients in the FOBT group were older and had a higher prevalence of hypertension, coronary artery disease, heart failure, diabetes, chronic obstructive pulmonary disease, and higher BMI. Two well-matched groups of n=1,728/1,728 were used for comparing outcomes. The FOBT group had similar 30-day mortality (4.45% vs 4.01, P=0.56) as well as similar bleeding events (0.98% vs 0.69%, P=0.35). Troponin levels in the FOBT group were on average lower (0.41 vs 0.95, P=0.04). The FOBT groups also had a similar average length of stay of (14.1 days vs 14.2 days, P=0.42). 233 patients who received FOBT underwent endoscopic evaluation with either upper endoscopy or colonoscopy (13.5%), and there was no significant difference in 30-day mortality (6.86% vs 4.7%, P=0.321). Among patients who underwent endoscopy, 72 had some form of endoscopic intervention (30.9%). There was no difference in 30-day mortality between patients undergoing endoscopy with intervention and without intervention (14.49%/14.49%) P=1.00. Readmission was similar between patients undergoing endoscopy with and without intervention. Conclusions In a large multi-center national database, we observed similar outcomes in patients who were admitted with NSTEMI and had FOBT and those not receiving FOBT in terms of all-cause mortality and bleeding events. In patients with positive FOBT, endoscopy with and without intervention we observed no significant difference in 30-day mortality. We conclude that there is no compelling evidence for FOBT testing in patients with NSTEMI.

A Case of Peripartum Spontaneous Coronary Artery Dissection in a Woman With a History of Obesity

Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome (ACS) with a high prevalence in young pregnant females. A 38-year-old female with a history of morbid obesity status post-bariatric surgery presented with chest pain. The electrocardiogram (EKG) revealed ST-segment elevation in the inferior leads as well as slightly elevated troponin. Urgent cardiac catheterization showed SCAD, and she was subsequently managed with medical therapy. We hypothesize that the history of obesity leads to a compromise in the coronary vasculature, thereby predisposing the patient to SCAD.

Cardiovascular disease in women: A review of spontaneous coronary artery dissection

Research has demonstrated the disproportionate quality of care for women with cardiovascular disease. These findings have prompted a renewed focus on cardiovascular disease awareness and disease prevention in women. Spontaneous coronary artery dissection (SCAD) is a significant cause of myocardial infarction (MI) and sudden death that primarily affects women. ongoing research has led to improved diagnostic capabilities and changes in approaches to initial and long-term management most importantly this research has provided evidence that SCAD is more common than previously thought and must be evaluated and treated differently from atherosclerotic MI. The difference between SCAD and atherosclerotic MI is highlighted in high rates of recurrent disease, gender distribution, association with exogenous hormones, pregnancy, migraine, physical and emotional stress triggers, concurrent systemic arteriopathies, and connective tissue disease. In this review, we provide updated insights and a summary of the epidemiology, risk factors, clinical presentation, diagnosis, treatment options, prognosis, and recurrence prevention of SCAD. We aim to provide a review of SCAD as a focus on cardiovascular disease awareness and disease prevention in women.

Shortening the duration of dual antiplatelet therapy after percutaneous coronary intervention for acute coronary syndrome: A systematic review and meta-analysis

INTRODUCTION

The decision to shorten the duration of DAPT following PCI in patients with ACS remains controversial because of the concern for increased ischemic events.

METHODS

We performed a comprehensive literature search in seven databases to explore the efficacy of 1 to 3 months of DAPT in patients who underwent PCI for ACS. Randomized controlled trials that compared 1 to 3 months with 6 to 12 months of DAPT after PCI for ACS were identified. Integrated hazard ratio (HR) and 95% confidence interval (CI) were calculated by random effects model for each prespecified outcome of interest. Meta-regression analyses were performed to examine the association of outcomes with select patient characteristics.

RESULTS

A total of 9 randomized controlled trials consisting of 25,907 patients were included. There was no difference in the hazard of NACE (HR 0.92, 95% CI 0.79-1.07) and MACE (HR 0.96, 95% CI 0.78-1.17) between 1 and 3 months of DAPT and 6 to 12 months of DAPT. However, implementing 1 to 3 months of DAPT was associated with lower hazard of both any bleeding (HR 0.55, 95% CI 0.46-0.66) and major bleeding (HR 0.47, 95% CI 0.36-0.62). Meta-regression revealed a nonsignificant but increasing trend of both NACE and MACE with greater proportion of left main and left anterior descending coronary artery lesions and greater proportion of STEMI included in the trials.

CONCLUSION

Our findings suggest that 1 to 3 months of DAPT has similar efficacy for preventing ischemic events with reduced bleeding risk compared with 6 to 12 months of DAPT.

Clinical Profile of Acute Coronary Syndrome Presentation to the Ladysmith Provincial Hospital: High Prevalence Among the Minority Indian Population

Background

Cardiovascular diseases were responsible for 17% of the 460236 natural deaths in South Africa in 2015. Previous studies have reported a disproportionately higher incidence of ischemic heart disease (IHD) and its risk factors among individuals of Indian descent residing in South Africa. The aim of this study was to explore the clinical profile of patients presenting with a diagnosis of acute coronary syndrome (ACS) and to compare the characteristics of patients of Indian descent to those of non-Indian descent.

Methods

Retrospective data were derived from the medical charts of 160 consecutive patients presenting to the Ladysmith Provincial Hospital over a 44-month period with a diagnosis of ACS. Findings were described and compared.

Results

The mean (SD) age of study patients was 55.8 (±12.8) years. The majority of subjects were male (n=90, 56.3%) and unemployed (n=98, 62.3%). The racial distribution of the study sample comprised 103 (64.4%) Indian, 36 (22.5%) Black, and 21 (13.1%) White subjects. Compared to non-Indian subjects, a significantly higher proportion (p<0.05) of Indian subjects were male (64.7% vs 41.4%), cigarette smokers (52.0% vs 32.8%), had a previous history of ACS (37.3% vs 10.3%), were diabetic (33.3% vs 17.2%), and were hypertensive (58.8% vs 29.3%).

Conclusion

The disproportionately high frequency of ACS among the minority Indian population of Ladysmith is concerning. There is a need for rigorous public health interventions to create local awareness, encourage lifestyle modification, and thereby improve control of cardiovascular risk factors, especially among high-risk population groups.

The Outcomes of Acute Coronary Syndrome in Patients Suffering From Schizophrenia: A Systematic Review

Acute coronary syndrome (ACS) is a principal cause of mortality and morbidity worldwide. Recent studies have suggested poorer outcomes in ACS patients who have a concurrent diagnosis of schizophrenia as compared with those without. However, the degree of interplay between schizophrenia and ACS remains poorly understood. For this reason, we conducted a systematic review on ACS outcomes in patients with schizophrenia by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We collected relevant data from PubMed, Cochrane Library, PubMed central, Jisc Library Hub Discover, and the National Library of Medicine (NLM) and performed a thorough quality appraisal. Fourteen shortlisted, relevant studies were meticulously reviewed. Mortality and major adverse cardiac events (MACE), bleeding, and stroke were more prevalent in patients with a schizophrenia diagnosis compared to those without. Additionally, schizophrenia patients received suboptimal care and follow-up when compared to patients without a psychiatric diagnosis. Clinicians need to be aware that patients with schizophrenia have worse outcomes following ACS which may relate to biological, health care, or patient-related factors.

Impella-Assisted Intracoronary Lithotripsy of Severely Calcified Left Main Coronary Artery Bifurcation for NSTEMI With Cardiogenic Shock

High calcification of coronary artery plaque is a frequent cause of suboptimal stent expansion, which can result in stent thrombosis and restenosis. Shockwave intravascular lithotripsy (S-IVL) represents a new frontier in the treatment of highly calcified coronary lesions. It can be an excellent alternative to intracoronary atherectomy in extremely high-risk lesions. We present a case of a 57-year-old man with known severe coronary artery disease (CAD) who presented with non-ST segment elevation myocardial infarction (NSTEMI), cardiogenic shock and was successfully treated with impella-assisted shockwave-intravascular lithotripsy permitting successful percutaneous intervention of a high-risk left main coronary artery (LMCA) bifurcation in-stent restenosis.

"Two for One", Novel Dual Left Anterior Descending Artery (LAD) Variant: Type XIII

Dual left anterior descending artery (LAD) is a rare phenomenon that occurs in less than one percent of the population. To date, 12 variants have been identified. Proper identification of coronary vessels is crucial in emergent situations that require prompt action, such as percutaneous coronary intervention (PCI). We propose that our case highlights a novel 13th (type XIII) variant. We present the case of a 57-year-old African American woman with a past medical history of hypertension, glaucoma, cerebral vascular accident, dyslipidemia who presented to the ED complaining of atypical chest pain for one day duration. Electrocardiography showed normal sinus rhythm at 60 beats per minute (bpm), normal axis, normal intervals, no acute ischemic changes, and an isolated T wave inversion in DIII. Cardiac markers were within normal limits. The patient was started on aspirin 81mg, atorvastatin 40mg, and restarted on amlodipine 5mg. Echocardiography showed a left ventricular ejection fraction (LVEF): 65%, normal right ventricular size and systolic function, mild mitral valve regurgitation, and mild aortic regurgitation. Computed tomographic (CT) angiography showed a novel subtype of dual LAD, the left circumflex and right coronary arteries were patent. The patient was discharged once stabilized and advised to follow up with cardiology. Dual LAD describes a rare anatomic variant in which two coronary branches, known as short and long LAD arteries, supply the territory normally supplied by the solitary LAD artery. To date, 12 variants of dual LAD, classified by origin and course of the short and long LAD arteries, have been described in the literature. To the best of our knowledge, the current case describes a novel subtype of dual LAD, variant XIII. The LAD originates as usual from the left main coronary artery (LMCA) and initially runs in the anterior interventricular groove for a short course before bifurcating into two long LADs which both leave the interventricular groove and course out to the apex. One of the vessels courses laterally and the other courses medially of the interventricular groove. It is pertinent to identify the coronary vessels accurately before certain interventions are taken. Acknowledgement of this phenomenon can help guide accurate management in the future for patients with this condition.

Spontaneous Coronary Artery Dissection: An Unusual Cause of ST-Elevation Myocardial Infarction in Young Males

Spontaneous coronary artery dissection (SCAD) is a non-traumatic, non-iatrogenic, and non-atherosclerotic coronary artery disorder that manifests clinically as an acute coronary syndrome (ACS), arrhythmia, or sudden cardiac death (SCD). It is a rare cause of ACS (1.7-4%) and SCD (0.5%), more commonly in women than men. It is rarely reported in males. We report a case of acute ST-elevation myocardial infarction (STEMI) due to SCAD in a 44-year-old healthy male.

COVID-19 Infection Complicated by a Complete Occlusion of the Left Circumflex Artery With Acute Restenosis After Drug-Eluting Stent Placement

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause a hypercoagulable state that can complicate the management of patients presenting with acute myocardial infarction (MI). We present the case of a patient with coronavirus disease 2019 (COVID-19) with ST elevation MI who was treated with percutaneous coronary intervention and stenting to the left circumflex artery. He was treated appropriately with anticoagulation with appropriate activated clotting time. However, the coronary angiogram course was complicated with heavy thrombosis that involved the left circumflex artery and the left anterior descending artery. Physicians are urged to suspect heparin resistance in COVID-19 patients, particularly if those patients have venous thromboembolism or acute coronary syndrome while taking heparin.

Role of Cardio-Specific Micro-Ribonucleic Acids and Correlation with Cardiac Biomarkers in Acute Coronary Syndrome: A Comprehensive Systematic Review

Acute coronary syndrome (ACS) is an acute and severe manifestation of coronary artery disease (CAD); thus, timely diagnosis can save a life. Commonly, cardiac troponin T (CTnT), cardiac troponin I (CTnI) or creatine kinase muscle/brain subtype (CK-MB) have been used as cardiac biomarkers to assess ACS with certain limitations, such as increased time to rise for diagnosis and increased levels in the patients with chronic kidney disease (CKD). Recently, micro-ribonucleic acids (miRNAs) have become potential candidates as biomarkers for cardiac ischemia due to their remarkable stability and reproducibility. Certain miRNAs, for instance, miR-1, miR-133a/b, miR-208a/b, and miR-499a, strongly increase in the serum or plasma of patients with acute cardiac ischemia, making them as cardio-specific miRNAs and prospective biomarkers in ACS. This literature review gives enlightenment about the regulation of cardio-specific miRNA in acute myocardial ischemia (AMI) and correlation with common cardiac biomarkers and time at which they increase in the blood.

The state of cartilage regeneration: current and future technologies

It is clear that mature human articular cartilage does not have the innate ability to regenerate. Due to this, much effort has been put forth to work on bestowing this ability. While early data focused on more basic outcomes such as percentage of defect fill, the tissue formed was a "cartilage scar" or "hyaline-like" tissue. Even with more advanced technologies, it is clear that no current procedure is able to reconstitute the native structure and function of true hyaline cartilage. As research advancement has somewhat plateaued in this regard, it is crucial that future work focuses on a multifactorial approach, treating the joint as an organ system. The purpose of this review is to update readers on the most recent literature and controversies surrounding articular cartilage regeneration. Specific focus will be placed on current technologies available in the USA and the basic science to support them.

The spatiotemporal program of replication in the genome of Lachancea kluyveri

We generated a genome-wide replication profile in the genome of Lachancea kluyveri and assessed the relationship between replication and base composition. This species diverged from Saccharomyces cerevisiae before the ancestral whole genome duplication. The genome comprises eight chromosomes among which a chromosomal arm of 1 Mb has a G + C-content much higher than the rest of the genome. We identified 252 active replication origins in L. kluyveri and found considerable divergence in origin location with S. cerevisiae and with Lachancea waltii. Although some global features of S. cerevisiae replication are conserved: Centromeres replicate early, whereas telomeres replicate late, we found that replication origins both in L. kluyveri and L. waltii do not behave as evolutionary fragile sites. In L. kluyveri, replication timing along chromosomes alternates between regions of early and late activating origins, except for the 1 Mb GC-rich chromosomal arm. This chromosomal arm contains an origin consensus motif different from other chromosomes and is replicated early during S-phase. We showed that precocious replication results from the specific absence of late firing origins in this chromosomal arm. In addition, we found a correlation between GC-content and distance from replication origins as well as a lack of replication-associated compositional skew between leading and lagging strands specifically in this GC-rich chromosomal arm. These findings suggest that the unusual base composition in the genome of L. kluyveri could be linked to replication.

Antiplatelet and antithrombin strategies in acute coronary syndrome: state-of-the-art review

Antiplatelet and antithrombotic agents significantly alter the clinical course of patients with acute coronary syndrome (ACS) and hence form the bedrock of the management pathway of this closely related continuum of coronary pathologies. The contemporary therapeutic armamentarium for the treatment of ACS now reflects the many technical and pharmacological advances that took place over the last two decades. In the original 1996 American College of Cardiology/ American Heart Association (ACC/AHA) guidelines for the management of acute myocardial infarction, only one antiplatelet agent (Aspirin) and one anticoagulant (unfractionated heparin) were recommended as class I therapies. Since then many newer agents have been developed and approved for routine clinical use in ACS patients. Recent research has focussed on improving efficacy on one hand and reducing bleeding complications on the other. This review focuses on the mechanism, efficacy, safety profile and clinical trial evidence of P2 Y12 receptor antagonist antiplatelet agents, glycoprotein IIb/IIIa receptor inhibitors (GPI), protease-activated receptor-1 (PAR-1) inhibitors, thrombin inhibitor bivalirudin and Factor Xa inhibitors fondaparinaux and rivaroxaban.

Parallel reconstruction using null operations

A novel iterative k-space data-driven technique, namely parallel reconstruction using null operations (PRUNO), is presented for parallel imaging reconstruction. In PRUNO, both data calibration and image reconstruction are formulated into linear algebra problems based on a generalized system model. An optimal data calibration strategy is demonstrated by using singular value decomposition, and an iterative conjugate-gradient approach is proposed to efficiently solve missing k-space samples during reconstruction. With its generalized formulation and precise mathematical model, PRUNO reconstruction yields good accuracy, flexibility, and stability. Both computer simulation and in vivo studies have shown that PRUNO produces much better reconstruction quality than generalized autocalibrating partially parallel acquisition (GRAPPA), especially under high accelerating rates. With the aid of PRUNO reconstruction, ultra-high accelerating parallel imaging can be performed with decent image quality. For example, we have done successful PRUNO reconstruction at a reduction factor of 6 (effective factor of 4.44) with eight coils and only a few autocalibration signal lines.

Effects of abscisic acid on ethylene biosynthesis and perception in Hibiscus rosa-sinensis L. flower development

The effect of the complex relationship between ethylene and abscisic acid (ABA) on flower development and senescence in Hibiscus rosa-sinensis L. was investigated. Ethylene biosynthetic (HrsACS and HrsACO) and receptor (HrsETR and HrsERS) genes were isolated and their expression evaluated in three different floral tissues (petals, style-stigma plus stamens, and ovaries) of detached buds and open flowers. This was achieved through treatment with 0.1 mM 1-aminocyclopropane-1-carboxylic acid (ACC) solution, 500 nl l(-1) methylcyclopropene (1-MCP), and 0.1 mM ABA solution. Treatment with ACC and 1-MCP confirmed that flower senescence in hibiscus is ethylene dependent, and treatment with exogenous ABA suggested that ABA may play a role in this process. The 1-MCP impeded petal in-rolling and decreased ABA content in detached open flowers after 9 h. This was preceded by an earlier and sequential increase in ABA content in 1-MCP-treated petals and style-stigma plus stamens between 1 h and 6 h. ACC treatment markedly accelerated flower senescence and increased ethylene production after 6 h and 9 h, particularly in style-stigma plus stamens. Ethylene evolution was positively correlated in these floral tissues with the induction of the gene expression of ethylene biosynthetic and receptor genes. Finally, ABA negatively affected the ethylene biosynthetic pathway and tissue sensitivity in all flower tissues. Transcript abundance of HrsACS, HrsACO, HrsETR, and HrsERS was reduced by exogenous ABA treatment. This research underlines the regulatory effect of ABA on the ethylene biosynthetic and perception machinery at a physiological and molecular level when inhibitors or promoters of senescence are exogenously applied.

Comparison of Framingham, PROCAM, SCORE, and Diamond Forrester to predict coronary atherosclerosis and cardiovascular events

BACKGROUND

Cardiologists are often confronted with patients presenting with chest pain, in whom clinical risk profiling is required. We studied four frequently used risk scores in their ability to predict for coronary artery disease (CAD) and major adverse cardiovascular events in patients presenting with stable chest pain at the cardiology outpatient clinic.

METHODS AND RESULTS

We enrolled 1,296 stable chest pain patients, who underwent cardiac computed tomographic angiography (CCTA) to assess CAD (any, significant: stenosis ≥50%). Framingham (FRS), PROCAM, SCORE risk score, and Diamond Forrester pre-test probability were calculated. All patients were followed up for a mean 19 ± 9 months for all cardiovascular events (mortality, acute coronary syndrome, revascularization >90 days after CCTA). In ROC-analysis for prediction of significant CAD, the areas under the curve for FRS; 0.68 (95% confidence interval: 0.64-0.72) and for SCORE; 0.69 (95% confidence interval: 0.65-0.72) were significantly higher than for PROCAM; 0.64 (95% confidence interval: 0.61-0.68; P ≤ .001), as well as marginally higher than for Diamond Forrester; 0.65 (95% confidence interval: 0.61-0.68; P ≤ .05). Low FRS category showed the lowest number of patients with significant CAD, compared to patients with low risk using PROCAM, SCORE or Diamond Forrester (P < .001). Also, low FRS category showed less events (compared to PROCAM and SCORE; P < .001, for Diamond Forrester; P = .14).

CONCLUSION

Our data show that in a stable chest pain population, the ability of FRS and SCORE to predict for CAD was similar and better compared to PROCAM and Diamond Forrester. The number of low risk patients showing significant CAD or events was lower using FRS. Consequently, risk categorization using FRS seems to be safest to stratify stable chest pain patients prior to CCTA.

Protocol: An updated integrated methodology for analysis of metabolites and enzyme activities of ethylene biosynthesis

BACKGROUND

The foundations for ethylene research were laid many years ago by researchers such as Lizada, Yang and Hoffman. Nowadays, most of the methods developed by them are still being used. Technological developments since then have led to small but significant improvements, contributing to a more efficient workflow. Despite this, many of these improvements have never been properly documented.

RESULTS

This article provides an updated, integrated set of protocols suitable for the assembly of a complete picture of ethylene biosynthesis, including the measurement of ethylene itself. The original protocols for the metabolites 1-aminocyclopropane-1-carboxylic acid and 1-(malonylamino)cyclopropane-1-carboxylic acid have been updated and downscaled, while protocols to determine in vitro activities of the key enzymes 1-aminocyclopropane-1-carboxylate synthase and 1-aminocyclopropane-1-carboxylate oxidase have been optimised for efficiency, repeatability and accuracy. All the protocols described were optimised for apple fruit, but have been proven to be suitable for the analysis of tomato fruit as well.

CONCLUSIONS

This work collates an integrated set of detailed protocols for the measurement of components of the ethylene biosynthetic pathway, starting from well-established methods. These protocols have been optimised for smaller sample volumes, increased efficiency, repeatability and accuracy. The detailed protocol allows other scientists to rapidly implement these methods in their own laboratories in a consistent and efficient way.

Ripening-associated ethylene biosynthesis in tomato fruit is autocatalytically and developmentally regulated

To investigate the regulatory mechanism(s) of ethylene biosynthesis in fruit, transgenic tomatoes with all known LeEIL genes suppressed were produced by RNA interference engineering. The transgenic tomato exhibited ethylene insensitivity phenotypes such as non-ripening and the lack of the triple response and petiole epinasty of seedlings even in the presence of exogenous ethylene. Transgenic fruit exhibited a low but consistent increase in ethylene production beyond 40 days after anthesis (DAA), with limited LeACS2 and LeACS4 expression. 1-Methylcyclopropene (1-MCP), a potent inhibitor of ethylene perception, failed to inhibit the limited increase in ethylene production and expression of the two 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) genes in the transgenic fruit. These results suggest that ripening-associated ethylene (system 2) in wild-type tomato fruit consists of two parts: a small part regulated by a developmental factor through the ethylene-independent expression of LeACS2 and LeACS4 and a large part regulated by an autocatalytic system due to the ethylene-dependent expression of the same genes. The results further suggest that basal ethylene (system 1) is less likely to be involved in the transition to system 2. Even if the effect of system 1 ethylene is eliminated, fruit can show a small increase in ethylene production due to unknown developmental factors. This increase would be enough for the stimulation of autocatalytic ethylene production, leading to fruit ripening.