Sildenafil Prevents Cardiovascular Changes after Bone Marrow Fat Embolization in Sheep

Background: Sudden, intraoperative cardiovascular deterioration as a result of pulmonary embolization of bone marrow fat is a potentially fatal complication during total hip and knee arthroplasty, intramedullary nailing, and spine surgery. Anesthetic management is challenging in the presence of increased right ventricular afterload due to pulmonary hypertension. Selective pulmonary vasodilation may be an appropriate prophylactic or therapeutic measure. The effect of sildenafil (phosphodiesterase inhibitor) on cardiovascular deterioration after bone marrow fat embolization was therefore investigated.

Methods: Bone cement (polymethylmethacrylate) was injected into three lumbar vertebrae in 12 sheep. Invasive blood pressures and heart rate were recorded continuously until 60 min after the last injection. Cardiac output and arterial and mixed venous blood gas variables were measured at selected time points. Before the first cement injection, 6 animals received a bolus injection (0.7 mg/kg) of sildenafil, with continuous infusion (0.2 mg [middle dot] kg-1 [middle dot] h-1) thereafter. Postmortem lung and kidney biopsies were taken for semiquantitative analysis of intravascular fat.

Results: Fat embolism was associated with a transient increase (21 +/- 7mmHg) in pulmonary arterial pressure. A transient decrease in arterial blood pressure and temporary increases in central venous pressure and dead space were also observed. No significant changes in any cardiovascular variable were observed after fat embolism in the sildenafil group. There was significantly (P < 0.05) less intravascular fat in the lungs of the sildenafil (median count of 5 emboli per microscopic view) compared with the control group (median count of 1).     

Protein C concentrate prevents peripartum thrombosis.

A protein C deficient woman, with a past history of recurrent thrombosis and purpura fulminans, was successfully treated with protein C concentrate in the peripartum period. © 1992 Wiley-Liss, Inc.     

The antiphlogistic,antinociceptive and antipyretic properties of fenclorac

Fenclorac (a,m-dichloro-p-cyclohexylphenylacetic acid, diethylammonium salt) is a potent nonsteroidal anti-inflammatory agent with significant analgesic and antipyretic activity. Fenclorac had an ED₅₀ of 7.9 mg/kg in the carrageenan paw edema assay and had a duration of action of 18–22 hours. Comparative tests in the carrageenan paw edema assay in the rat indicated that the potency of fenclorac was 13 times that of aspirin, 3.4 times phenylbutazone, 3 times ibuprofen and 0.3 times indomethacin. Fenclorac was less potent than indomethacin, but more potent than phenylbutazone or aspirin in treatment of developing or established adjuvant arthritis. The anti-inflammatory effectiveness of fenclorac did not depend upon the integrity of the adrenopituitary axis and was not affected by the route of administration or sex of the test animal. Fenclorac was 77 times more potent than aspirin and more than twice as potent as indomethacin in reducing fever in rats rendered hyperthermic with brewer's yeast. Fenclorac did not affect normal body temperatures. Fenclorac did not interfere with cellular immune mechanisms as measured by its lack of effectiveness in experimental allergic encephalomyelitis. Antinociceptive testing indicated that fenclorac had peripheral but not central analgesic activity. Fenclorac had an acute oral LD₅₀ in rats and mice of 285 and 430 mg/kg, respectively. The acute gastric lesion UD₅₀ for fenclorac was 7 mg/kg in the fasted rat. Studies using⁵¹Cr-tagged erythrocytes indicated that fenclorac did not produce significant fecal blood loss in the rat at twice the therapeutic ED₅₀ dose for up to 12 days after dosing. Extensive and prolonged fecal blood loss was observed with a corresponding dose of indomethacin for up to nine days after administration. Comparison of the antiinflammatory pharmacology, Therapeutic Ratio and the data obtained from the⁵¹Cr-fecal blood loss studies indicated that fenclorac was well tolerated after acute or subacute administration to the rat.     

Complete nucleotide sequence of wound tumor virus genomic segments encoding nonstructural polypeptides

Sequence analysis of the genomic segments which encode the five wound tumor virus nonstructural polypeptides has been completed. The complete nucleotide sequence of segments S4 (2565 bp), S6 (1700 bp), S9 (1182 bp), and S10 (1172 bp) are presented in this report while the sequence of segment S12 (851 bp) has been described previously (T. Asamizu, D. Summers, M. B. Motika, J. V. Anzola, and D. L. Nuss, 1985, Virology 144, 398-409). Comparison of the only published sequence for another member of the genus Phytoreovirus, that of rice dwarf virus segment S10, with the combined available wound tumor virus sequence data revealed similarity with WTV segment S10: 54.9 and 30.6% at the nucleotide and amino acid level, respectively. Although wound tumor virus and rice dwarf virus differ in plant host range, tissue specificity, vector range, and disease symptom expression, the level of sequence similarity shared by the two segments suggests a common origin for these viruses. The potential use of a phytoreovirus sequence database for predicting functions of viral encoded gene products is considered.