Search PubMedSearch

SEARCH · Search PubMed

Results for “Collateral Circulation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

8 recordsLinked to original sources

Distinct immune-metabolic phenotypes underlie poor coronary collateral circulation.

BACKGROUND: Coronary collateral circulation (CCC) significantly impacts myocardial perfusion and clinical outcomes in coronary artery disease patients, yet the underlying molecular heterogeneity remains inadequately characterized. OBJECTIVE: To identify distinct molecular phenotypes in patients with poor CCC, validate these phenotypes using clinical parameters, and evaluate their prognostic implications. METHODS: This study enrolled 149 patients (80 with good CCC and 69 with poor CCC) for high-throughput proteomic profiling. Unsupervised consensus clustering identified molecular subtypes within poor CCC patients, followed by differential expression analysis and KEGG pathway enrichment. Boruta feature selection was implemented, and multiple machine learning algorithms were tested on clinical data, with XGBoost optimization (accuracy 80.0%, F1-score 80.31%) and SHAP value interpretation. External validation was performed using the MIMIC database. Kaplan-Meier analysis and Cox regression models assessed major adverse cardiovascular events (MACE). RESULTS: Two distinct phenotypes emerged among poor CCC patients: Cluster 1 (n&#x2009;=&#x2009;39, Complement-Driven Vascular Remodeling [CDVR]) and Cluster 2 (n&#x2009;=&#x2009;30, Immuno-Thrombotic Myocardial Dysfunction [ITMD]). An XGBoost model incorporating fasting glucose, eosinophil percentage, and HbA1c achieved excellent discrimination (AUC&#x2009;>&#x2009;0.91). External validation confirmed the phenotype-specific clinical patterns. Notably, Cluster 2 demonstrated significantly higher MACE incidence compared to Cluster 1 (Log-rank p&#x2009;<&#x2009;0.05), with KEGG analysis revealing significant upregulation of platelet activation, diabetic cardiomyopathy, and metabolic pathways in the ITMD phenotype. CONCLUSION: Poor CCC encompasses distinct immune-metabolic phenotypes that can be accurately classified using integrated proteomic-clinical modeling. This classification enables more precise risk stratification and may guide personalized therapeutic strategies for coronary artery disease patients with inadequate collateralization.

Humans

Epilepsy of infancy with migrating focal seizures: A scoping review of clinical features, diagnostic testing including genetics, long-term outcomes, mortality, and current and emerging therapeutic strategies.

BACKGROUND: Epilepsy of infancy with migrating focal seizures (EIMFS) is among the most severe developmental and epileptic encephalopathies (DEEs), marked by intractable multifocal seizures migrating across both hemispheres, profound developmental arrest, and high early mortality. Advances in next-generation sequencing have revealed a heterogeneous genetic architecture dominated by KCNT1 gain-of-function variants across more than 30 implicated genes, creating opportunities for precision therapeutics. OBJECTIVE: To systematically map published evidence on the clinical, electrophysiological, neuroimaging, genetic, and therapeutic landscape of EIMFS, and to delineate critical knowledge gaps and future research priorities. METHODS: A scoping review was conducted following the Arksey and O'Malley framework, searching PubMed, Ovid MEDLINE, Embase, Cochrane Library/CENTRAL, and ClinicalTrials.gov. RESULTS: Of 643 articles screened, 89 met inclusion criteria. Beyond confirmation of the canonical electroclinical phenotype, several gaps emerged: neonatal versus post-neonatal onset stratification by genetic etiology remains largely uncharacterized; genotype-specific EEG biomarkers are lacking except for a single small KCNT1 study; and the clinical significance of atypical EEG features-including burst suppression and hypsarrhythmia-is undefined. Neuroimaging literature documents progressive cerebral atrophy and myelination abnormalities without quantitative volumetry, diffusion tractography markers, or attribution to seizure burden, medication effects, or underlying etiology. Genetic diagnostic yield was 70-80%, with KCNT1 accounting for 30-50% of solved cases; however, genotype-outcome stratification is limited. Seizures were broadly refractory; potassium bromide, ketogenic diet, cannabidiol, and quinidine (in KCNT1-confirmed cases) showed partial efficacy. Emerging precision approaches include sodium channel blockers for SCN2A gain-of-function variants, novel small molecules, fluoxetine, antisense oligonucleotides, and divalent siRNA targeting KCNT1. Systemic-to-pulmonary collateral circulation causing severe cardiopulmonary complications was reported across multiple cases, yet no consensus screening protocol exists. CONCLUSIONS: EIMFS remains one of the most refractory epilepsy syndromes of infancy. Precision genetic diagnosis is essential to guide targeted therapy. International collaborative registries, standardized outcome measures, genotype-stratified biomarker studies, and rapid point-of-care genomic testing are urgently needed to advance evidence-based care for this highly vulnerable population.

Humans

Atherosclerotic cerebral infarction: pathophysiologic aspects.

When the supply of substrate to the brain is threatened, homeostatic mechanisms induce cerebral vasodilatation to compensate for the insufficiency. When a region of the brain is rendered completely ischemic, local infarction occurs. The size of the infarct depends partly on the availability of collateral circulation and the adequacy of the homeostatic mechanisms controlling blood flow in stillpatent vessels. Several approaches to acute-phase treatment of stroke derive from clinical and experimental studies of cerebral blood flow and metabolism. We must conclude that both surgical and nonsurgical therapeutic measures have been of limited value in the treatment of cerebral infarction and that the basic therapy for completed stroke remains good medical management of complications and attentive nursing care.

Blood Flow Velocity

Effects of graded infusions of monomethylmethacrylate on coagulation, blood lipids, respiration and circulation. An experimental study in dogs.

In 4 dogs injected intravenously (i.v.) with 125I labeled fibrinogen, 51Cr labeled platelets and 99mTc labeled albumin, and subjected to successively increasing amounts of i.v. infused monomethylmethacrylate, doses corresponding to the amounts released into the blood stream following implantation of acrylic cement during total hip replacements did not affect the clotting mechanism, did not cause trapping of platelets and fibrin in the lungs, did not generate fat emboli, and did not cause depression of the arterial oxygen tension or blood pressure. Monomethylmethacrylate in whole blood was associated with both blood cells and plasma.

Animals

Effects of regional ischemia on metabolism of glucose and fatty acids. Relative rates of aerobic and anaerobic energy production during myocardial infarction and comparison with effects of anoxia.

The rate of coronary flow reaching the oxygen-linited heart appears to be crucial in determining the myocardial tissue metabolic response. The tissue metabolic response to anoxia, well studied in hearts perfused with anoxic media, differs in many important ways from the response to ischemia. In regional ischemia (developing infarction) there is still a residual oxygen uptake which is reduced approximately to the same extent as the delivery of O2; there is also decreased delivery of substrates and decreased removal of CO2, H+, and lactate, with increased concentrations of these metabolites. Contents of hexose monophosphates rise rather than fall in anoxia. Measurements of glycolytic intermediates show an initial burst of accelerated glycolytic flux lasting less than 1 minute after coronary artery ligation; thereafter rates of flux decrease to control values or even less at 120 minutes. Relative inhibition of phosphofructokinase (PFK) activity may be explained by a slow rate of fall of ATP and a developing intracellular acidosis. In this model, glucose accounts for a greater part of the residual oxidative metabolism than does free fatty acid (FFA).

Adenosine Triphosphate

Effects of metabolic and pharmacologic interventions on myocardial infarct size following coronary occlusion.

A number of hemodynamic, pharmacologic and metabolic interventions were found to change the extent of acute ischemic injury of the myocardium and subsequent necrosis following experimental coronary artery occlusion. Reduction in myocardial damage occurred by decreasing myocardial oxygen demands (beta-adrenergic blocking agents, intra-aortic balloon counterpulsation, external counterpulsation, nitroglycerin, decreasing afterload in hypertensive patients, inhibition of lipolysis, and digitalis in the failing heart); by increasing myocardial oxygen supply either directly (coronary artery reperfusion or elevating arterial pO2), or through collateral vessels (elevation of coronary perfusion pressure by alpha-adrenergic agonists, intra-aortic balloon counterpulsation); or by increasing plasma osmolality (mannitol, hypertonic glucose); presumably by augmenting anaerobic metabolism (glucose-insulin-potassium, hypertonic glucose); by enhancing transport to the ischemic zone of substrates utilized in energy production (hyaluronidase); by protecting against autolytic and heterolytic damage (hydrocortisone, cobra venom factor, aprotinin). Augmentation of myocardial ischemic damage occurred as a consequence of increasing myocardial oxygen requirements (isoproterenol, glucagon, ouabain, bretylium tosylate, tachycardia); by decreasing myocardial oxygen supply either directly (hypoxia, anemia) or through reduction of collateral flow (hemorrhagic hypotension, minoxidil) or by decreasing substrate availability glycemia). Pilot studies have been carried out in patients with hyaluronidase, nitroglycerin, intra-aortic balloon counterpulsation, beta-blocking agents and Arfonad and have shown that these interventions may also reduce myocardial damage, suggesting that the concept of reduction in infarct size following coronary occlusion is applicable clinically.

Acute Disease