Successful Prolonged Desensitization to Epoetin-Alfa Hypersensitivity in an Adult Patient With Advanced Chronic Kidney Disease.

The use of erythropoiesis-stimulating agents (ESAs) reduces the need for recurrent blood transfusions in patients with advanced kidney disease. Rarely, allergic reactions to recombinant human erythropoietin can develop, complicating anemia management due to cross-reactivity between these agents. We report the use of an outpatient desensitization protocol, which was successfully completed in an adult patient who developed a maculopapular rash as a form of delayed-type hypersensitivity reaction (DTH) to epoetin-alfa (EPO) use, followed by successful re-introduction of EPO and continued tolerance.

Cerebral Venous Sinus Thrombosis with Bilateral Abducens Palsy in a Patient with Heterozygous Prothrombin G20210A Mutation.

We present a rare case of cerebral venous thrombosis in a patient with heterozygous mutation of the prothrombin G20210A gene. A 24-year-old Caucasian male complained of sudden onset diplopia due to bilateral abducens palsy and throbbing headache with pulsatile tinnitus. Computed tomography revealed extensive thrombus in the right sigmoid sinus, right transverse sinus, and the superior sagittal sinus. Except for the prothrombin mutation, no other predisposing risk factors were found. The patient was treated with heparin, later transitioned to enoxaparin and warfarin, and subsequently, the symptoms improved on follow-up. This case reveals the rare occurrence of cerebral venous thrombosis in a patient having prothrombin gene G20210A mutation alone. Early diagnosis and treatment can lead to a good prognosis.

Photochemical interaction of ascorbic acid and nicotinamide in aqueous solution: A kinetic study.

The photodegradation of ascorbic acid (AH2) in the presence of nicotinamide (NA) at pH 2.0-12.0 has been studied using a 30 W UV radiation source. The reaction follows first-order kinetics and the values of apparent first-order rate constants (kobs) at 1 × 10-3 M NA concentration range from 1.17 (pH 2.0) to 3.61 × 10-3 min-1 (pH 12.0). The values of these rate constants (k0) in the absence of NA range from 0.50 (pH 2.0) to 1.75 × 10-3 min-1 (pH 12.0), indicating that the values of kobs for the photodegradation of AH2 in the presence of NA are about 2 fold compared to those of the AH2 alone. The second-order rate constants (k') for the photochemical interaction of AH2 and NA are in the range of 0.67 (pH 2.0) and 1.86 × 10-3 M-1 min-1 (pH 12.0). The k'-pH profile shows a gradual increase in the rate as a function of pH. This is due to the ionization of AH2 to give ascorbyl anions (AH-) which are more susceptible to photodegradation compared to the neutral molecule (AH2). NA appears to undergo photochemical interaction with AH2 during the reaction by acting as an electron acceptor to enhance its rate of photodegradation. The concentrations of AH2 and NA in degraded solutions have been determined by a two-component spectrometric method at 243 and 261 nm (pH 2.0) with a precision of ±2%. The method has been validated and the results are comparable to the HPLC method.