Quantitative analysis of ephedrines in urine by HPLC

Simultaneous determination of six ephedrines in urine sample has been achieved by high performance liquid chromatography on a Lichrospher RP-18 column, using methylamphetamine as internal standard. The 6 ephedrines are well separated in 25 minutes with resolution better than 1.8. This method has high recovery, selectivity and reproducibility, and the linearity is satisfactory from 1.5 micrograms/ml to 25 micrograms/ml with correlation coefficients better than 0.999.     

Synthesis of Hexp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1-->O) (CH2)7 CH3 probes for exploration of the substrate specificity of glycosyltransferases: Part II, Hex = 3-O-methyl-beta-D-Gal, 3-deoxy-beta-D-Gal, 3-deoxy-3-fluoro-beta-D-Gal, 3-amino-3-deoxy-beta-D-Gal, beta-D-Gul, alpha-L-Alt, or beta-L-Gal

Seven analogues of the trisaccharide beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1-->O)(CH 2)7CH3 have been synthesized as potential substrates for glycosyltransferases involved in the chain-termination of N-acetyllactosamine-type N-glycans. These compounds include: 3-O-methyl-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp -(1-->O) (CH2)7CH3, 3-deoxy-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1 -->O) (CH2)7CH3, 3-deoxy-3-fluoro-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-M anp- (1-->O)(CH2)7Ch3, 3-amino-3-deoxy-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Ma np- (1-->O)(CH2)7CH3, beta-D-Gulp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1-- >O)(CH2)7CH3, beta-L-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1-->O)(CH 2)7CH3, and alpha-L-Altp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1- ->O) (CH2)7CH3. All trisaccharides were obtained by condensation of suitably modified glycosyl donors based on imidates or thioglycosides with the same disaccharide acceptor, octyl 3,4,6-tri-O-benzyl-2-O-(3,6-di-O-benzyl-2-deoxy-2-phthalimido-beta-D- glucopyranosyl)-alpha-D-mannopyranoside, followed by deprotection.     

Revised cutoff values of serum aminotransferase in detecting viral hepatitis among CAPD patients: experience from Taiwan, an endemic area for hepatitis B

BACKGROUND: To determine the best cutoff values of aspartate aminotransferase (AST) and alanine amino-transferase (ALT) in detecting viral hepatitis C infection among patients of continuous ambulatory peritoneal dialysis (CAPD). METHODS: 90 (44 male and 46 female) CAPD patients and 526 adult controls (266 male, 260 female) were enrolled. Serum AST and ALT were measured by an auto-analyser monthly. Serum HBsAg was examined using a RIA method and anti-HCV by an second-generation EIA method. The best cutoff values of AST and ALT for detecting viral hepatitis were obtained from the ROC (receiver-operating characteristic) curve. RESULTS: The prevalence of anti-HCV(+) was significantly higher in CAPD patients (16.7%) than in normal controls (4.9%), while that of HBsAg(+) was similar in both groups. CAPD patients had significantly lower levels of serum aminotransferases compared to normal controls. Mean AST were 23.8 IU/l in normal control and 18.8 IU/l in the CAPD patients (P < 0.001). Mean ALT were 21.9 IU/l in normal controls and 15.3 IU/l in the CAPD patients (P < 0.001). CAPD patients with HCV infection had higher serum AST and ALT levels than those without. However, HBV infection did not cause significant serum aminotransferase elevation in patients. The conventional cutoff values of AST (40 IU/l) and ALT (40 IU/l) for detecting viral hepatitis yielded only a sensitivity of 27.3 and 18.2% respectively; on the contrary, our revised cutoff values of AST (24 IU/l) and ALT (17 IU/l) had better sensitivities (AST, 72.7%; ALT, 63.6%). For serial aminotransferase values, the sensitivity of AST and ALT for detecting HCV were 36.4 and 27.3% by conventional criteria, and were both 81.8%, by our newly revised criteria. CONCLUSIONS: Serum aminotransferase cutoff values should be modified for screening viral hepatitis in a CAPD population. Our new cutoff criteria had important clinical implications in providing benefits of earlier detection and possible prevention from chronic hepatic deteriorations.     

Multi-input,multi-output flight control system design for the YF-16 using nonlinear QFT and pilot compensation

Nonlinear quantitative feedback theory (QFT) and pilot compensation techniques are used to design a 2 × 2 flight control system for the YF-16 aircraft over a large range of plant uncertainty. The design is based on numerical input-output time histories generated with a FORTRAN implemented nonlinear simulation of the YF-16. The first step of the design process is the generation of a set of equivalent linear time-invariant (LTI) plant models to represent the actual nonlinear plant. It has been proven that the solution to the equivalent plant problem is guaranteed to solve the original nonlinear problem. Standard QFT techniques are then used in the design synthesis based on the equivalent plant models. A detailed mathematical development of the method used to develop these equivalent LTI plant models is provided. After this inner-loop design, pilot compensation is developed to reduce the pilot's workload. This outer-loop design is also based on a set of equivalent LTI plant models. This is accomplished by modelling the pilot with parameters that result in good handling qualities ratings, and developing the necessary compensation to force the desired system responses.     

Partial congenital defect of the left pericardium: angiographic diagnosis and treatment by thoracoscopic pericardiectomy: case report

Twenty-six patients with an intracardiac myxoma underwent surgical resection at our institution from 1977 through 1992. Left atrial myxoma was diagnosed in 22 patients, left ventricular in 1, right atrial in 2, and right ventricular in 1. Six patients were asymptomatic; preoperative symptoms included dyspnea, arrhythmias, embolic episodes, and syncope. The diagnosis was established with transthoracic echocardiography in all cases but one. Surgery was performed in all cases with the aid of cardiopulmonary bypass with moderate hypothermia and cold crystalloid cardioplegia. One patient with a left ventricular myxoma died in a comatose state during the immediate postoperative period. Long-term clinical and echocardiographic evaluation was performed in 19 patients; results were excellent (all the patients were in New York Heart Association functional class I or II), and no recurrences were documented. The clinical characteristics, diagnostic methods, and surgical approach are presented and discussed.     

A hyperplastic anterior choroidal artery with double persistent anastomotic channels

We describe a case of a hyperplastic anterior choroidal artery (AChA) with double persistent anastomotic channels. This hyperplastic AChA, which was detected at vertebral angiography, is different from previously reported cases, because it has an unusual, secondary anastomotic channel.     

A PC program for diagnosing abnormal growth, growth velocity and acceleration from longitudinal observations

A human fibroblastic cell line transformed by the SV40-T antigen sequence and continuously cultured for 7 months displayed large periodic variations in cell proliferation. This contrasted with other characteristics of this cell line that remained constant: mosaic cell shape, absence of cell contact inhibition, and predominance of a hypodiploid population. Similar fluctuations in proliferative capacity were also found during the long-term growth of a transformed but nonimmortalized human fibroblastic line prior to senescence, and in the established hamster fibroblastic Nil cell line. This growth pattern suggests a recurrent stimulation of growth in these three transformed cell lines. The proliferation pattern from cultured transformed cells may thus be complex and requires further investigation. These variations presumably influence major cell functions. This observation has important implications for the analysis of data from such cell lines.