Search

Dolichol and dolichyl derivatives have an important function as glycosyl carriers in the assembly of the N-asparaginyllinked oligosaccharide core region of glycoproteins. Dolichols are synthesized through the cholesterol biosynthesis pathway in all mammalian organs and are present in all tissues, and are also associated with lipoproteins in the blood circulation. However, the origin and metabolic pathway of blood dolichols remain unknown. Abetalipoproteinaemia is a disorder of the secretion of very low-density lipoprotein (VLDL) from the liver and of chylomicrons from the intestine into the blood circulation. Therefore, examination of blood dolichols in this disorder may provide valuable information on their origin and metabolic pathway. Dolichols were exclusively associated with the high-density lipoprotein (HDL) fraction (80·7±6·3% of total dolichols) in control human blood. Serum from a patient also contained dolichols in the HDL fraction (82·8% of total dolichols). The total amount of dolichols was higher in the patient (207·0 ng/mL) than in the controls (106·2±22·7 ng/mL, n= 14). The compositions of dolichols were very similar to each other. These results indicated that, at least in the patient with abetalipoproteinaemia, the HDL-associated dolichols were possibly derived from the liver not through other lipoproteins but through dolichol transfer protein, or were possibly taken up and carried by HDL from peripheral tissues.

A combination of electrophysiological, pathological, and biochemical studies were performed in myopathy induced by 3-hydroxy-3-methylglutaryl–coenzyme A (HMG–CoA) reductase inhibitors. Simvastatin (a lipophilic inhibitor) or pravastatin (a hydrophilic inhibitor) were administered by gavage to rabbits. In Group I (simvastatin-treated group, 50 mg/kg/day for 4 weeks), four rabbits showed muscle necrosis and high serum creatine kinase (CK) levels, and all six rabbits showed electrical myotonia. In Group II (pravastatin-treated group, 100 mg/kg/day for 4 weeks), no rabbit showed either condition. In Group III (pravastatin-treated group, 200 mg/kg/day for 3 weeks plus 300 mg/kg/day for 3 weeks), one rabbit showed muscle necrosis and high serum CK level and two rabbits showed electrical myotonia. The pathological findings were muscle fiber necrosis and degeneration with increased acid phosphatase activity by light microscopy, autophagic vacuoles and mitochondrial swelling, and disruption and hypercontraction of myofibrils by electron microscopy. Ubiquinone content decreased in skeletal muscle by 22 to 36% in Group I, by 18 to 52% in Group II, and by 49 to 72% in Group III. However, mitochondrial enzyme activities of respiratory chain were normal in all groups. These results indicate that myopathy was not induced by a secondary dysfunction of mitochondrial respiration due to low ubiquinone levels.

Abstract: To avoid intraabdominal abscess and biliary fistula, which may lengthen hospital stay or result in lethal complications after major hepatic resection, it is important to control postoperative bleeding and bile leakage. We employed a technique for preventing postoperative bleeding and bile leakage, using omental packing with fibrin glue for the transected surface of the remnant liver after hepatic resection. This procedure was employed in 50 patients who underwent major hepatic resection. There was no postoperative bleeding or biliary fistula, and drain tubes were removed within 5 days in all patients. Omental packing with fibrin glue could be a very useful procedure of preventing postoperative biliary fistula, bleeding, and abscess after major hepatic resection.