Rosuvastatin is a substrate for certain transporter proteins including the hepatic uptake transporter organic anion -transporting polyprotein 1B1 (OATP1B1) and efflux transporter breast cancer resistance protein (BCRP). Concomitant administration of rosuvastatin calcium with medications that are inhibitors of these transporter proteins (. cyclosporine, certain HIV protease inhibitors) may result in increased rosuvastatin plasma concentrations and an increased risk of myopathy [see DOSAGE AND ADMINISTRATION ]. It is recommended that prescribers consult the relevant product information when considering administration of such products together with rosuvastatin calcium.
Toxic acute tubular necrosis is characterized by proximal tubular epithelium necrosis (no nuclei, intense eosinophilic homogenous cytoplasm, but preserved shape) due to interference of ingested toxic agents (poisons, organic solvents, drugs, heavy metals) with epithelial cell metabolism. Necrotic cells fall into the tubule lumen, obliterating it, and determining acute renal failure (oligo-anuria). Basement membrane is intact, so the tubular epithelium regeneration is possible, if the patient survives. The interstitium and glomeruli are not affected. (H&E, ob. x20)
By far the most common isotope of calcium in nature is 40 Ca, which makes up % of all natural calcium. It is produced in the silicon-burning process from fusion of alpha particles and is the heaviest stable nuclide with equal proton and neutron numbers; its occurrence is also supplemented slowly by the decay of primordial 40 K . Adding another alpha particle would lead to unstable 44 Ti, which quickly decays via two successive electron captures to stable 44 Ca; this makes up % of all natural calcium and is the second-most common isotope. The other four natural isotopes, 42 Ca, 43 Ca, 46 Ca, and 48 Ca, are significantly rarer, each comprising less than 1% of all natural calcium. The four lighter isotopes are mainly products of the oxygen-burning and silicon-burning processes, leaving the two heavier ones to be produced via neutron-capturing processes. 46 Ca is mostly produced in a "hot" s-process , as its formation requires a rather high neutron flux to allow short-lived 45 Ca to capture a neutron. 48 Ca is produced by electron capture in the r-process in type Ia supernovae , where high neutron excess and low enough entropy ensures its survival.