: 152  Tapering from the inner to the outermost surface, they have a diameter of 2.5 μm near the pulp, 1.2 μm in the middle of the dentin, and 0.9 μm at the dentino-enamel junction. Their density is 59,000 to 76,000 per square millimeter near the pulp, whereas the density is only half as much near the enamel. Within the tubules, there is an odontoblast process, which is an extension of an odontoblast, and dentinal fluid, which contains a mixture of albumin, transferrin, tenascin and proteoglycans. In addition, there are branching canalicular systems that connect to each other. These branches have been categorized by size, with major being 500-1000 nm in diameter, fine being 300-700 nm, and micro being less than 300 nm. : 155  The major branches are the terminal ends of the tubules. About every 1-2 μm, there are fine branches diverging from dentinal tubules at 45 degree angles. The microtubules diverge at 90 degree angles. The dentinal tubules contain the cytoplasmic extensions of odontoblasts that once formed the dentin and maintain it. The cell bodies of the odontoblasts are aligned along the inner aspect of dentin against a layer of predentin where they also form the peripheral boundary of the dental pulp Because of dentinal tubules, dentin has a degree of permeability, which can increase the sensation of pain and the rate of tooth decay.
Though safety has been established through previous clinical trials, there is ongoing debate about whether this is an effective treatment for ischemic stroke, and significant ongoing discussion between Emergency Physicians, Neurologists and Pharmacists about whether this treatment should be used for that indication. The American Heart Association/American Stroke Association 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke supports considering tenecteplase over alteplase in patients without contraindication to intravenous thrombolytics. Pharmacokinetics
Distribution: approximates plasma volume
Metabolism: Primarily hepatic
Half-life elimination: Biphasic: Initial: 20–24 minutes; Terminal: 90–130 minutes
Excretion: Clearance: Plasma: 99-119 mL/minute

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MedlinePlus DrugInfo uspdi-500145