Cardiology

Depression medication could also protect against heart disease

The antidepression drug duloxetine could be beneficial to patients with both depression and cardiovascular disease, according to new studies performed in human blood and in mice. Globally, more than 300 million people have ...

Diseases, Conditions, Syndromes

Repurposed heart and flu drugs may help body fight sepsis

Despite continued improvements in antibiotics and hospital intensive care, staph sepsis—a bloodstream infection caused by Staphylococcus aureus bacteria—still causes severe illness or death in 20 to 30 percent of patients ...

Cardiology

Biomedical device can prevent deaths caused by blood clots

New portable technology that visualizes clots forming in flowing blood in a 3-D holographic livestream promises to dramatically improve screening and treatment of stroke, heart attack and coronavirus-induced lung failure.

Diseases, Conditions, Syndromes

Platelets may play key role in development of lupus

Platelets may play a key role in the development of lupus, according to a study published today by researchers at Université Laval and CHU de Québec-Université Laval Research Center. Extracellular DNA circulating in the ...

Diseases, Conditions, Syndromes

What blood platelets and endothelial cells may reveal about COVID-19

Yale researchers have helped identify the mechanisms behind a major cause of morbidity and mortality in COVID-19 patients. Extensive blood clots in both large and small blood vessels in the lungs and throughout many major ...

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Platelet

Platelets, or thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are small, irregularly shaped clear cell fragments (i.e. cells that do not have a nucleus containing DNA), 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes.  The average lifespan of a platelet is normally just 5 to 9 days. Platelets are a natural source of growth factors. They circulate in the blood of mammals and are involved in hemostasis, leading to the formation of blood clots.

If the number of platelets is too low, excessive bleeding can occur. However, if the number of platelets is too high, blood clots can form (thrombosis), which may obstruct blood vessels and result in such events as a stroke, myocardial infarction, pulmonary embolism or the blockage of blood vessels to other parts of the body, such as the extremities of the arms or legs.  An abnormality or disease of the platelets is called a thrombocytopathy, which could be either a low number of platelets (thrombocytopenia), a decrease in function of platelets (thrombasthenia), or an increase in the number of platelets (thrombocytosis). There are disorders that reduce the number of platelets, such as heparin-induced thrombocytopenia (HIT) or thrombotic thrombocytopenic purpura (TTP) that typically cause thromboses, or clots, instead of bleeding.

Platelets release a multitude of growth factors including Platelet-derived growth factor (PDGF), a potent chemotactic agent, and TGF beta, which stimulates the deposition of extracellular matrix.  Both of these growth factors have been shown to play a significant role in the repair and regeneration of connective tissues.  Other healing-associated growth factors produced by platelets include basic fibroblast growth factor, insulin-like growth factor 1, platelet-derived epidermal growth factor, and vascular endothelial growth factor.  Local application of these factors in increased concentrations through Platelet-rich plasma (PRP) has been used as an adjunct to wound healing for several decades.

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