Pharmacokinetics of two alternative dosage forms for cyclosporine: liposomes and intralipid

Cyclosporine (CsA), commercially available as iv or oral Sandimmune, is a potent immunosuppressant which can induce dose-related nephrotoxocity. In addition, the iv product contains a solubilizing agent, Cremophore EL, which in itself is reported to be nephrotoxic and can induce, in sensitized patients, anaphylactic reactions. Solubilization of CsA with liposomes or lipid emulsions could provide a suitable alternative dosage form for iv administration. With this in mind, male New Zealand white rabbits were given iv CsA (10 mg/kg) in three different dosage forms: (1) CsA:liposomes; (2) CsA:Intralipid (soybean oil and phospholipids); and (3) the commercially available Sandimmune (cyclosporine). The CsA concentration in whole blood samples was analyzed by HPLC. The terminal disposition half-life of CsA (t1/2 beta) ranged from 400 to 475 min and was not statistically different among the three groups. However, the distribution characteristics of CsA changed dramatically depending on the dosage form. The volume of distribution of CsA at steady state (Vdss) in Sandimmune was 2.7 +/- 0.2 L/kg and was significantly lower than that of either Intralipid (10.6 +/- 2.7 L/kg) or liposomes (7.4 +/- 2.3 L/kg). A significantly lower total body clearance (TBC) of CsA also was seen for Sandimmune (12.7 +/- 0.3 mL/min/kg) as compared with that of either Intralipid (24.4 +/- 8.2 mL/min/kg) or liposomes (18.9 +/- 3.9 mL/min/kg). Since CsA is extensively bound to lipoproteins, it is surprising that both test vehicles showed a different distribution pattern.(ABSTRACT TRUNCATED AT 250 WORDS)     

Recombinant activated factor VII for intractable bleeding post splenectomy in a patient with myeloproliferative disorder.

Recombinant activated factor VII has been Food and Drug Administration approved to treat hemorrhages in hemophiliac patients with inhibitors and in acquired hemophilia patients. Recombinant activated factor VII use has also been considered for the management of uncontrolled bleeding in a number of congenital and acquired hemostatic abnormalities. The myeloproliferative disorders are a group of clonal hematologic diseases where, frequently, abnormal platelet function is considered a hallmark. This is the first case report addressing the clinical benefit of off-label use of recombinant activated factor VII in an attempt to control intractable bleeding in a patient with a myeloproliferative disorder after splenectomy.     

Folic acid in the treatment of acute watery diarrhoea in children: a double-blind, randomized, controlled trial

One-hundred and six male children aged 6-23 months with a history of acute watery diarrhoea of less than 72 h duration were randomized to receive either folic acid in a dose of 5 mg at 8-h intervals or placebo for 5 d. There were 54 children in the folic acid group and 52 in the placebo group. The admission characteristics were comparable between the two groups. No significant differences were observed in the intake of oral rehydration solution or stool output between the groups. The mean ± SD of total stool output (g kg⁻¹) was 532 ± 476 vs 479 ± 354 and the duration (h) of diarrhoea was 108 ± 68 vs 103 ± 53 in the folic acid vs placebo group, respectively. The findings, therefore, should have a positive influence on preventing the inappropriate use of folic acid in acute diarrhoea.     

An Alternative Surgical Technique in Orthotopic Cardiac Transplantation

A bstract Forty patients underwent orthotopic cardiac transplantation at Wythenshawe Hospital between May 1991 and November 1992. Twenty patients had transplantation using an alternative technique that preserves the shape of the left atrium and leaves the right atrium intact (group A). The remaining twenty had conventional transplantation using the technique described by Lower and Shumway (group B). The patients were randomized to either the new or the conventional technique on an alternate basis. There was no mortality in group A, but two patients in group B developed right ventricular failure and died. Two patients in each group developed nodal rhythm and all four recovered sinus rhythm. Echocardiography and Doppler velocimetry at the transvalvular level confirmed normal atrial function in group A with erratic atrial contraction wave in group B. There was also slightly lower incidence of mitral and tricuspid valve regurgitation in group A than in group B. The improved atrial function in group A may play a part in the prevention of right sided failure following cardiac transplantation.     

Molecular and genetic characterizations of five pathogenic and two non-pathogenic monoclonal antiphospholipid antibodies

Antiphospholipid syndrome (APS) is an autoimmune disease that is characterized by thrombosis, recurrent fetal loss and thrombocytopenia. Antiphospholipid antibodies, detected by enzyme-linked immunoabsorbent assays (aCL) and/or in vitro blood clotting assays (LAC) are strongly associated with APS. Both the molecular structures used by pathogenic antiphospholipid antibodies and the genetic mechanisms leading to their production are unknown. We describe here the variable region genes of seven IgG antiphospholipid antibodies derived from two APS patients. Of these, five are pathogenic as defined in a mouse model of thrombosis and two are not. Analyses of the expressed variable region genes show no preferential V gene usage. However, similar to anti-DNA antibodies, pathogenic antiphospholipid antibodies contain an increased number of arginine residues in the third complimentarity-determining region (CDR3) of their H chains. The increased accumulation of arginine residues in the V(H) CDR3 may act to enhance antigen binding, promote disease and point to the importance of the H chain in the pathogenic potential of certain antiphospholipid antibodies.