Conversion to docosahexaenoic acid-containing phosphatidylserine from squid skin lecithin by phospholipase D-mediated transphosphatidylation

Phospholipase D (PLD)-mediated transphosphatidylation of squid skin lecithin with L-serine was examined to prepare docosahexaenoic acid-containing phosphatidylserine (DHA-PS). When a biphasic system with organic solvent and 0.2 M acetate buffer (pH 5.5) was used, PS synthesis was significantly affected by the amount of 3.4 M L-serine-containing acetate buffer. L-Serine concentration in the acetate buffer and choice of organic solvent were also crucial. In a typical reaction with 0.8 unit of PLD (Streptomyces sp.), 2.5 mL of ethyl acetate substrate solution containing 30 mg of squid skin lecithin in combination with 3 mL of 3.4 M L-serine-containing 0.2 M acetate buffer (pH 5.5), PS content in the recovered phospholipid fraction increased to 43.1% after 24 h. DHA composed 37.6% of fatty acids in the converted PS. This was the same DHA level as in the substrate. Phosphatidylcholine (squid skin PC, DHA 44.2%) in the squid skin lecithin was more effectively converted to PS than phosphatidylethanolamine.

Hepatotoxicity caused by both tacrolimus and cyclosporine after living donor liver transplantation

We present a case report of a posttransplant patient who had hepatotoxicity due to both tacrolimus and cyclosporine and cholestatic jaundice due to tacrolimus. The patient did not show sustained improvement in enzyme and bilirubin abnormalities after an initial change from tacrolimus to cyclosporine or with a change back to tacrolimus, but he ultimately showed improvement when the blood concentration of tacrolimus was lowered. A 56-year-old man with subacute fulminant hepatitis induced by acarbose was admitted to our hospital for living donor liver transplantation. The liver graft consisted of the left lobe from his ABO-identical son. The early posttransplant course was uneventful. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin improved initially, but the ALT and AST levels later increased. A liver biopsy suggested a presumptive diagnosis of drug reaction. All drugs were discontinued, the immunosuppressive agent was changed from tacrolimus to cyclosporine. After initial improvement, the ALT and AST levels increased again. Assuming a reaction to cyclosporine, we decreased the concentration of cyclosporine in the blood. The enzyme levels improved temporarily but again began to rise. We changed the immunosuppressive agent to tacrolimus, which resulted in improvements in the ALT and AST levels; however, the total bilirubin level increased. We interpreted this increase as tacrolimus-induced cholestasis; in response, we decreased the blood concentration of tacrolimus to between 3 and 5 ng/dL and added 1,000 mg of mycophenolate mofetil to the drug regimen. The patient recovered without further complications. Repeated liver biopsies throughout the hospital course suggested that the mild mononuclear cell infiltration observed in a few triads had not been caused by acute rejection but had possibly been drug-induced.

Quantitation of apolipoprotein A-I in pooled human serum by single radial immunodiffusion and sodium dodecyl sulfate-polyacrylamide gel electrophoresis

Apolipoprotein A-I was released from human HDL particles by treatment with 8 M urea, and the free apolipoprotein exhibited identical antigenicity and the same low mobility as purified apolipoprotein A-I in electrophoresis. Treatment of serum with 8 M urea enabled enabled quantitation of apolipoprotein A-I by single radial immunodiffusion assay, as judged by comparison with sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Effect of macrophage colony-stimulating factor on the function of resident peritoneal macrophages

Resident peritoneal cells of monocyte/macrophage lineage were collected by lavage of mice and incubated in vitro for 1-3 d in a culture medium containing various concentrations of macrophage colony-stimulating factor (M-CSF). Stimulation of the cells by zymosan showed that the potency of producing luminol-dependent chemiluminescence had been markedly increased in the CSF-treated cells, indicating increased generation of active oxygen species in these cells. There was an optimal concentration of M-CSF for the enhancement, and the potency of the cells was notably decreased by an overdose of M-CSF. The result was interpreted as being due to the down-regulation of M-CSF receptor.

Androgen-induced production of colony-stimulating factor (CSF) and colony-inhibitory factor (CIF) in the submandibular gland in female mice

Both testosterone (T) and 5 alpha-dihydrotestosterone (DHT) significantly increased colony-stimulating factor (CSF) as well as colony-inhibitory factor (CIF) in the submandibular gland (SMG) in female mice. The CIF activity was completely inactivated by heating at 60 degrees C for 15 min, while the CSF activity was stable against the heat treatment. It was found that the CSFs obtained from the androgen-treated female mice and from normal male mice behaved identically in chromatography on hydroxylapatite and Ultro-gel AcA 34 columns. The potency of DHT to increase CSF activity was about 10 times greater than that of T.

Modal-noise evaluation in multimode-fiber transmission

Modal noise that occurs at fiber connecting points has been investigated theoretically and experimentally. Visibility, an important factor that determines the modal-noise power, has been obtained as a function of laser-diode (LD) coherency and fiber bandwidth. Modal-noise formulas, with such parameters as visibility, fiber-connection loss, and the number of modes that the fiber supports, are presented. Modal noise that is due to LD mode-partition noise is also discussed. The analytical results agree well with the experimnental ones.