Facile purification of tocopherols from soybean oil deodorizer distillate in high yield using lipase

Tocopherols have been purified from deodorizer distillate produced in the final deodorization step of vegetable oil refining by a process including molecular distillation. Deodorizer distillate contains mainly tocopherols, sterols, and free fatty acids (FFA); the presence of sterols hinders tocopherol purification in good yield. We found that Candida rugosa lipase recognized sterols as substrates but not tocopherols, and that esterification of sterols with FFA could be effected with negligible influence of water content. Enzymatic esterification of sterols with FFA was thus used as a step in tocopherol purification. High boiling point substances including steryl esters were removed from soybean oil deodorizer distillate by distillation, and the resulting distillate (soybean oil deodorizer distillate tocopherol concentrate; SODDTC) was used as a starting material for tocopherol purification. Several factors affecting esterification of sterols were investigated, and the reaction conditions were determined as follows: A mixture of SODDTC and water (4∶1, w/w) was stirred at 35°C for 24 h with 200 U of Candida lipase per 1 g of the reaction mixture. Under these conditions, approximately 80% of sterols was esterified, but tocopherols were not esterified. After the reaction, tocopherols and FFA were recovered as a distillate by molecular distillation of the oil layer. To enhance further removal of the remaining sterols, the lipase-catalyzed reaction was repeated on the distillate under the same reaction conditions. As a result, more than 95% of the sterols was esterified in total. The resulting reaction mixture was fractionated to four distillates and one residue. The main distillate fraction contained 65 wt% tocopherols with low contents of FFA and sterols. In addition, the residue fraction contained high-purity steryl esters. Because the process presented in this study includes only organic solvent-free enzymatic reaction and molecular distillation, it is feasible as a new industrial purification method of tocopherols. This work was presented at the Biocatalysis symposium in April 2000, held at the 91st Annual Meeting and Expo of the American Oil Chemists Society, San Diego, CA.     

Detection and Quantitation of Left-to-Right Shunts from Radionuclide Angiocardiography Using the Homomorphic Deconvolution Technique

The homomorphic filtering method is described for the detection and quantitation of left-to-right shunts from radionuclide angiocardiography. First, the method is investigated theoreticatly and numerically using a realistic model with systemic recirculation. It is demonstrated that even in a noisy situation the shunt flow fraction can be relatively well estimated, if only the characteristics of the fiters used are suitable. Second, the method is applied to real data, i.e., the pulmonary time-activity curves from radionucUde anglocardiography. The presence or absence of a left-to-right shunt is determined using the ratio AT/MTT. The pulmonary-to-systemic flow ratios calculated from the areas of the two decomposed curves are compared with those from oximetry at cardiac catheterization. Good agreement between the Qp/Qs ratios calculated by oximetry and radionucUide angiocardiography is obtained.     

Novel non-peptide fibrinogen receptor antagonists. 1. Synthesis and glycoprotein IIb-IIIa antagonistic activities of 1,3,4-trisubstituted 2-oxopiperazine derivatives incorporating side-chain functions of the RGDF peptide

Based on the lead tetrapeptide RGDF, two possible non-peptide glycoprotein (GP) IIb-IIIa antagonists possessing an (S)-2-oxopiperazine-3-acetic acid moiety as a scaffold incorporating the indispensable Asp fragment were prepared, and (S)-4-[[trans-[4-(guanidinomethyl)-cyclohexyl]carbonyl]glycyl]-2- oxopiperazine-1,3-diacetic acid, 1a, was identified as a potential lead. A series of 3-substituted 2-oxopiperazine-1-acetic acids bearing the Arg-Gly equivalent at the 4-position were prepared and evaluated for their ability to prevent platelet aggregation and for their binding affinity for the GP IIb-IIIa receptor purified from human HEL cells. (S)-4-[(4-Amidinobenzoyl)glycyl]-3-[(methoxycarbonyl)methyl]- 2-oxopiperazine-1-acetic acid, 9 (TAK-029), inhibited in vitro human platelet aggregation with an IC50 value of 0.03 microM and GP IIb-IIIa-fibrinogen binding with an IC50 value of 0.49 nM. The [4-(2-aminoethyl)benzoyl]glycyl derivative 26 showed activity comparable to that of 9 (IC50 = 0.093 microM, guinea pig platelet aggregation assay). Compound 9 dose-dependently inhibited ex vivo platelet aggregation in guinea pigs (0.03 and 0.1 mg/kg, i.v.), and long-lasting inhibition of platelet aggregation was observed upon oral administration of 9 (3 mg/kg) to guinea pigs. On the other hand, the activity of 26 disappeared within 1 h after a dose of 1 mg/kg (i.v.). Compound 9 may therefore be useful in the clinical treatment of arterial thrombotic diseases.     

Brain vasopressin is involved in stress-induced suppression of immune function in the rat

A well-designed, adequately funded clinical trial based on sound science and conducted by experienced investigators and staff can falter if participating trial clinics are not managed well. Ten commandments for successful trial clinic management address key organizational and operational issues. Commandment I: Thou shalt know and follow thy rules. Commandment II: Thou shalt know and fulfill thy roles. Commandment III: Thou shalt meet thy commitments. Commandment IV: Thou shalt collaborate. Commandment V: Thou shalt communicate. Commandment VI: Thou shalt document. Commandment VII: Thou shalt honor thy participants. Commandment VIII: Thou shalt keep thy participants' secrets. Commandment IX: Thou shalt revere thy data. Commandment X: Thou shalt know and accept thy limitations. This report puts these commandments into context by providing concrete examples in the clinical trial setting. These commandments could serve as guidelines to the spectrum of personnel involved in the operations of a trial clinic, namely, principal investigators and co-investigators, trial coordinators, data managers, technicians, administrators, and support staff.     

Functional alveolar ridge reconstruction with prefabricated iliac crest free flap and osseointegrated implants after hemimaxillectomy

We achieved functional alveolar ridge reconstruction after hemimaxillectomy using a prefabricated iliac crest flap. The iliac crest was vascularized secondarily by a long rectus abdominis muscle flap with its inferior epigastric vessels intact to obtain an ideal anatomic location between the maxillary defect and microvascular anastomosis site. The iliac crest was tightly resurfaced with a split-thickness skin graft as well. After a bony surgical delay, the prefabricated iliac crest flap was microsurgically transferred to the face. Three osseointegrated implants were placed in the prefabricated iliac crest, and a dental prosthesis was worn with immobilization and stability. Our procedure enabled recovery of a satisfactory facial appearance and excellent masticatory function.     

Differential roles of apamin- and charybdotoxin-sensitive K+ conductances in the generation of inferior olive rhythmicity in vivo

The basic electrical rhythmicity of the olivocerebellar system was investigated in vivo using multiple electrode recordings of Purkinje cell (PC) complex spike (CS) activity. CSs demonstrate a 10 Hz rhythmicity, thought to result from the interaction of Ca2+ and Ca2+-dependent K+ conductances present in inferior olivary (IO) neurons. To assess the roles of different K+ channels in generating this rhythmicity, intraolivary microinjections of charybdotoxin (CTX) and apamin were used. Both K+ channel blockers increased average CS spike-firing rates. However, apamin produced a tonic increase in firing with a decrement in the CS rhythmicity. In contrast, after CTX administration, highly rhythmic CS discharges were interleaved with silent periods, suggesting that apamin- and CTX-sensitive K+ channels have distinct rhythmogenic roles in IO neurons. CTX-sensitive channels seem to be functionally coupled to low threshold Ca2+ channels, whereas the apamin-sensitive channels relate to high threshold Ca2+ channels. Blocking intraolivary GABAA receptors increases IO excitability and the spatial distribution of synchronized CS activity while disrupting its rostrocaudal banding pattern (). The present experiments show that K+ channel blockers increase IO excitability without causing widespread synchronization of CS activity. Thus, changes in the IO excitability have relatively little effect in determining the spatial organization of CS synchrony. In contrast, the degree of CS rhythmicity seemed to influence the patterns of CS synchrony. Thus, after CTX, increased CS rhythmicity was associated with increased intraband synchrony and decreased interband synchrony, whereas apamin had the opposite effects on intra- and interband synchronization.     

The relationship between stapling doughnuts: characteristics and functional results after total gastrectomy

BACKGROUND/AIMS: The objective of this study was to determine whether the thickness of the esophageal doughnut is related to postoperative results in total gastrectomy. METHODOLOGY: Thirty-eight total gastrectomy patients were studied, including 18 who underwent jejunal pouch reconstruction and 20 who did not have pouch reconstruction. We used the Proximate-ILS circular stapler, with purse-string suturing at the cut end of the esophagus performing only the mucosal layer manually in all cases. We divided the esophageal doughnuts after stapling into two groups: Group A: doughnut involving muscle tissue of 0-25% of the esophageal circumference; Group B: doughnut involved muscle tissue of 25-100% of the esophageal circumference. Reflux scores and the scintigraphic reflux index were determined. RESULTS: No significant difference was found between the two groups in reflux score or scintigraphic reflux index. CONCLUSIONS: These findings indicate that the degree of postoperative reflux esophagitis was not affected by the amount of the muscular layer included in the esophageal doughnut. Continuity, and not variability of the degree of involved muscle in the esophageal doughnut, is an important factor at the time of stapling.