OBJECTIVEStudies on the substance with nourishment Yin for a reasonable and rational auality appraise for turtleback.

METHODTo separate by chromatography and identifying with MS, 1H NMR, 13C NMR, IR.

RESULTTwo compounds were separated and identified as hexadecanoyl cholesterol ester and cholesterol.

CONCLUSIONThe two compounds are isolated from turtleback for the first time.

Animals ; Cholesterol ; isolation & purification ; Cholesterol Esters ; chemistry ; isolation & purification ; Materia Medica ; chemistry ; Turtles

Polyethylene glycol (PEG) lipid derivatives could increase the stability of liposomes in vivo and in vitro and prolong the circulation time of liposomes in vivo. However, the chemical bond between PEG and lipid was so stable that liposomes modified with traditional PEG-lipid derivatives could not release their contents at targeted tissue immediately and the pharmacodynamic effect was reduced. The concept of cleavable PEG-lipid was raised in recent years and these PEG-lipid derivatives could break under physiological or pathological condition. The cleavable PEG-lipid derivatives could prolong the circulation time of liposomes, and after arriving at targeted location, PEG fragment had cleaved from the surface of liposomes, so liposomes could bind with pathological cells and release contents into cells. Removal of the protective polymer layer is necessary once the liposome close to the tumour to allow to fuse and release drug. Attempts have been made to increase the circulation time and reconstitute the cellular affinity of liposomes by incorporating PEG-lipid derivatives. This review focused on the kinds of cleavable PEG-lipid derivatives, types of cleavage, the application feature to liposomes and the advantages and localizations.
Cholesterol ; analogs & derivatives ; chemistry ; Drug Delivery Systems ; methods ; Humans ; Liposomes ; chemistry ; Phosphatidylethanolamines ; chemistry ; Polyethylene Glycols ; chemistry

OBJECTIVETo discuss the feasibility of preparing gypenosides liposomes with sphingomyelin and cholesterol, and optimize the preparation process and prescription.

METHODGypenosides liposomes were prepared with sphingomyelin and cholesterol. The entrapment efficiency was determined by the protamine precipitation method. The entrapment efficiency was taken as the evaluation index to screen out the optimum preparation process for the new-type gypenosides liposomes. The preparation process was optimized by the orthogonal design. The new-type gypenosides liposomes were characterized by grain size, potential and atomic force microscope (AFM).

RESULTEthanol injection was the optimum process to prepare gypenosides liposome with sphingomyelin and cholesterol as follow: the ratio of gypenosides to sphingomyelin was 1: 10, the ratio of sphingomyelin to cholesterol was 4: 1, the pH of PBS buffer solution was 7.0, the hydration temperature was 45 degrees C, the entrapment efficiency was 79.06%, particle size was 191.4 nm, the Zeta potential was -33.16 mV, and the morphology were round under AFM.

CONCLUSIONIt was feasible to prepare gypenosides liposome with sphingomyelin and cholesterol. The gypenosides liposomes prepared by the optimum preparation process were good in morphology, particle size and reproducibility.

Cholesterol ; chemistry ; Drug Carriers ; chemistry ; Drug Compounding ; methods ; Gynostemma ; chemistry ; Liposomes ; chemistry ; Particle Size ; Plant Extracts ; chemistry ; Sphingomyelins ; chemistry

It is reported that polyethylene glycol-lipid (PEG-lipid) derivatives increase liposomes stability, prolong the blood circulation of liposomes, enhance their tumor-targeting efficiency, and improve drug efficacy. Therefore, it is of great importance to investigate the influence of modified PEG-lipid derivatives on the physical, chemical, and biological characteristics of liposomes for the promotion of dealing with the existed problems, such as the accelerated blood clearance (ABC) phenomenon when repeated intravous injection at a certain time-interval, and developing novel targeted pharmaceutical preparations. In this review, the effects of modified PEG-lipid derivatives were summarized in many aspects. It indicats that the chemical bonds (amide, ether, ester, and disulfide) between PEG and lipid, as well as the species of lipids, such as the commonly used phosphatidylethanolamine, cholesterol, and diacylglycerol have substantial effects on the grafted liposomes stability in vitro and in vivo. Besides, the properties of lipids (the fatty acid chain length and saturation) and the groups (methoxy, carboxylic and amino) at the distal ends of the PEG chains were also considered to be important factors. In the end, the influence of the average molecular weight of PEG and the molar ratio of PEG-lipid derivatives in the total lipid were further focused.
Cholesterol ; chemistry ; Drug Delivery Systems ; methods ; Drug Stability ; Fatty Acids ; chemistry ; Liposomes ; chemistry ; pharmacokinetics ; Phosphatidylethanolamines ; chemistry ; Polyethylene Glycols ; chemistry

Laboratory values change with age and interpreting laboratory results from elderly people using the reference intervals for younger adults may not be appropriate. The authors investigated the distribution patterns of routine chemistry values from elderly people to determine whether current reference intervals are also valid for elderly people. A total of 1,215 persons older than 65 years and 1,827 healthy adults below 65 years of age were evaluated. Blood samples were collected after an overnight fast and analyzed for chemistry tests. Computing the central 95th percentile showed that the total protein, albumin, ALP, LD, creatinine, uric acid, triglyceride, HDL-cholesterol, and electrolytes of elderly people were within the standard reference intervals used in our laboratory. For AST and ALT, the upper range of the central 95th percentile in the elderly population was found to be outside the common reference interval. However, the central 90th percentile values of AST and ALT were compatible with the common reference intervals. GGT, BUN, total cholesterol, LDL-cholesterol, and glucose showed higher values than the upper limits of the reference intervals. For common clinical chemistry tests, the common reference values in general should be applicable to elderly people, even though some parameters showed wider distributions in the elderly.
Adult ; Aged ; Chemistry, Clinical ; Cholesterol ; Clinical Chemistry Tests ; Creatinine ; Electrolytes ; Glucose ; Humans ; Reference Values ; Uric Acid

A hydrophobic low-density lipoprotein cholesterol (LDL-C) adsorbent was synthesized with lauric acid and chitosan. The condition for adsorption was obtained by investigating the influence of adsorbent amount and adsorption time. The results of adsorption in vitro showed that the average adsorption rates for total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C) and total protein (TP) were 47.7%, 84.7%, 18.1% and 5.9% respectively. The adsorbent possesses good selectivity in removing LDL-C.
Adsorption ; Blood Component Removal ; methods ; Chitosan ; chemistry ; Cholesterol, LDL ; blood ; isolation & purification ; Lauric Acids ; chemistry

BACKGROUND: It is known that the blood collection tube used can cause fluctuations in laboratory test results. We compared test results obtained when blood was collected in V-tube (AB Medical, Korea), BD Vacutainer Tubes (BD, USA), and Greiner Vacuette Tubes (Greiner, USA) in clinical chemistry and thyroid hormone assays. METHODS: One hundred volunteers from three hospitals were recruited and the peripheral blood samples were collected in each of the three serum separation tubes (SSTs). These samples were used for 28 routine clinical chemistry assays and three thyroid hormone assays. The results were analyzed by the Student paired t-test and the Bland-Altman plot. For stability tests, the initial results were compared with the day 1 (24±2 hours), day 3 (72±2 hours), and day 7 (168±2 hours) results, respectively. RESULTS: The difference in the test results obtained from the samples in each tube (V-Tube vs. BD-Tube, V-Tube vs. Greiner-Tube, and BD-Tube vs. Greiner-Tube) were satisfied with the Clinical Laboratory Improvement Amendments of 1988 allowable difference ranges. Except for four analytes (low-density lipoprotein cholesterol, magnesium, potassium, and thyroid-stimulating hormone), all analytes were within the allowable critical difference range based on biological variability. The paired t-test revealed significant differences between the results of nine assays for samples in V-Tube vs. BD-Tube and seven assays for samples in V-Tube vs. Greiner-Tube, but each set of results showed good correlations. The test results on different days showed a significant difference in several assays, but they were within the allowable difference range. CONCLUSIONS: The assay results for blood samples collected in SST V-Tubes were comparable to those obtained when blood was collected in BD Tubes and Greiner Tubes, and the blood collected in V-Tubes also showed excellent results in the stability tests.
Chemistry ; Chemistry, Clinical* ; Cholesterol ; Humans ; Lipoproteins ; Magnesium ; Potassium ; Thyroid Gland* ; Vacuum* ; Volunteers

Herpetin (HPT) is an active monomer constituent isolated from lignanoid in seeds of Herpetospermum caudigerum. HPT shows inhibitory effects in hepatic injury and HBV-DNA and the replication. In the study, we successfully prepare herpetin liposomes by film dispersion method for the first time. The prescription process was optimized, with the entrapment efficiency as the index. According to the optimized prescription, the mass ratio of HPT: phospholipids: cholesterol was 2.44:78.05: 19.51, the hydration and de-molding process was performed with 0.5% F68 solution at 50 degrees C, and the water-bath ultrasonic time was 20 min. The HPT liposomes prepared by this method showed an average entrapment efficiency of (94.50 +/- 2.15)% and a particle size of (119.2 +/- 10.7) nm, which was consistent with the trial expectations and will lay a solid foundation for the hepatic targeting delivery system in future.
Chemistry, Pharmaceutical ; methods ; Cholesterol ; chemistry ; Drug Compounding ; methods ; Drugs, Chinese Herbal ; chemistry ; Lignans ; chemistry ; isolation & purification ; Liposomes ; chemistry ; Phospholipids ; chemistry ; Ultrasonics

BACKGROUND: Results of automated clinical chemistry tests are affected by many factors including analytical variability. In 1976, the College of American Pathologists (CAP) Conference on the analytical goals in clinical chemistry recommended that analytical variability should be less than 1/4 of the appropriate biological variability to improve distinction between normal and diseased populations. This study is conducted to evaluate whether automated clinical chemisty analyses performed in our laboratory is in conformance with the CAP's recommendation. METHODS: Routine chemistry and electrolyte tests were performed using Hitachi 747 automatic analyzer on 22 healthy volunteers. Blood samples were obtained from the volunteers' same vein twice in one week interval to study the total variability. Serum samples from 12 subjects were tested in duplicate immediately after blood collection for within-run analytical variability; and samples from another 10 subjects were repeated after 6 hours for within-day analytical variability. Within-run analytical variability plus within-day analytical variability make total analytical variability. Biological variability was defined as the difference between total variability and the analytical variability. Finally, ratios of analytical and biological variabilities were calculated. RESULTS: The ratios of analytical and biological variabilities of uric acid, glucose, and K were less than 0.25. But ratios of BUN, PO4, alkaline phosphatase, total bilirubin, AST, cholesterol, ALT, Cl, and protein exceeded 0.25. The ratios of Na, Ca, albumin, CO2, and creatinine could not be calculated. CONCLUSIONS: It is suggested that the analytical processes of the automated clinical chemistry tests be improved so as to be in conformity with the CAP's recommendation.
Alkaline Phosphatase ; Bilirubin ; Chemistry ; Chemistry, Clinical* ; Cholesterol ; Clinical Chemistry Tests* ; Creatinine ; Glucose ; Healthy Volunteers ; Uric Acid ; Veins

OBJECTIVEFamilial hypercholesterolemia (FH) is an autosomal dominant disease with an estimated worldwide prevalence of 0.2%. It is caused by a multitude of low density lipoprotein receptor gene mutations. It is characterized with high levels of total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and a high incidence of coronary artery disease in young adults. Cord blood cholesterol concentration is used for mass screening of FH. The purpose of this study was to detect the lipid levels of cord blood in newborn infants from China and to determine the cut-off point after 1 to 2 years follow-up.

METHODSTC, triglycerides (TG), LDL-C and high density lipoprotein cholesterol (HDL-C) were determined in 242 healthy full-term newborn infants.

RESULTSThe mean values of TC, TG, LDL-C and HDL-C in cord blood were (1.69 +/- 0.40) mmol/L, (0.23 +/- 0.12) mmol/L, (0.81 +/- 0.21) mmol/L and (0.58 +/- 0.16) mmol/L (mean +/- standard deviation), respectively. The HDL-C concentration in male neonates was lower than that in female neonates (P < 0.05).

CONCLUSIONAfter the follow-up of 1 to 2 years for FH, the recommended screening cut-off points were TC > or = 2.47 mmol/L and LDL-C > or = 0.89 mmol/L.

China ; Cholesterol ; blood ; Cholesterol, HDL ; blood ; Cholesterol, LDL ; blood ; Female ; Fetal Blood ; chemistry ; Humans ; Hyperlipoproteinemia Type II ; blood ; diagnosis ; Infant, Newborn ; Male ; Triglycerides ; blood