Analysis of Cholesterol in All Lipoprotein Classes by Single Vertical Ultracentrifugation of Fingerstick Blood and Controlled-Dispersion Flow Analysis

This new, highly sensitive analytical system, based on controlled dispersion of the flowing sample, gives a rapid, continuous, and direct analysis for cholesterol in all lipoprotein classes, separated by single vertical-spin density-gradient ultracentrifugation. In this Vertical Auto Profile-II fingerstick system, designated VAP-IIfs, a narrow-bore Teflon coil serves as the reactor with no segmentation of the analytical stream by air bubbles, in contrast to the Technicon AutoAnalyzer used in the VAP-I method. Concentrations of high-, low-, intermediate-, and very-low-density lipoprotein cholesterol and lipoprotein(a) cholesterol are determined by decomposing the spectrophotometric absorbance curve for the continuous analysis of the centrifuged sample, with use of software developed in this laboratory. Total cholesterol is determined from the total area under the absorbance curve. For assaying total cholesterol, the CV between aliquots within a rotor ranged from 1.35% to 3.15%; the CV between rotors was 2.45%. Because only 18 microL of sample is required, VAP-IIfs can be readily adapted to analysis for lipoprotein cholesterol profiles in capillary blood samples. Total cholesterol values by VAP-IIfs for fingerstick and venous samples from 23 subjects agreed well: slope = 1.01 (SD 0.03), intercept = -21 (SD 51) mg/L, Sy/x = 50 mg/L, and r = 0.992. Results by VAP-IIfs also correlated highly with results for duplicate samples analyzed at the Northwest Lipid Research Laboratories.

Sarcomatoid carcinoma of the hand: a clinical case with an aggressive and uncommon presentation

Cutaneous sarcomatoid carcinoma is a high-grade malignancy. We describe a clinical case of an aggressive sarcomatoid carcinoma in an 87-year-old woman, who presented to the outpatients department with a haemorrhagic nodule on the dorsum of her right hand. By the time of excision 3 weeks later, the nodule had enlarged to 100 × 90 × 65 mm in size. On histological examination, a poorly differentiated carcinoma was seen, with both carcinomatous and sarcomatous elements, in keeping with a sarcomatoid carcinoma. The tumour was positive for cytokeratin, epithelial, smooth-muscle actin, and vimentin stains. Two months later, the patient presented with a recurrent growth on the excised scar along with numerous large right axillary lymph nodes. A right axillary dissection along with excision of the growth confirmed tumour recurrence with metastasis to lymph nodes. Soon after, the patient developed cerebral metastasis, which proved fatal. This case thus highlights the aggressive potential of sarcomatoid carcinoma.

Studies on the immunomodulatory activity of flavonoidal fraction of Tephrosia purpurea

The flavonoid fraction of Tephrosia purpurea (FFTP) was studied for its effect on cellular and humoral functions and on macrophage phagocytosis in mice. Oral administration of FFTP (10-40 mg/kg) significantly inhibited sheep red blood cells (SRBC)-induced delayed-type hypersensitivity reactions. It also produced a significant, dose-related decrease in sheep erythrocyte-specific haemagglutination antibody titre. However, the fraction failed to show a significant change in the macrophage phagocytic activity. The results obtained indicate the ability of the flavonoidal fraction of T. purpurea to modulate both the cell-mediated and the humoral components of the immune system.

Influence of ethanolic extract of Tephrosia purpurea Linn. on mast cells and erythrocytes membrane integrity

The ethanolic extract of T. purpurea Linn. was studied for its in vitro effect on rat mast cell degranulation and erythrocyte membrane integrity in vitro. The extract in concentration of 25-200 microg/ml showed a dose-dependant inhibition of rat mast cell degranulation induded by compound 48/80 and egg albumin. T. purpurea extract was found to inhibit haemolysis of erythrocytes induced by hypotonic solution but accelerated haemolysis induced by heat at a concentration of 100 microg/ml. The studies reveal that the ethanolic extract of T. purpurea may inhibit degranulation of mast cells by a mechanism other than membrane stabilization.

A sensitive and convenient method for lipoprotein profile analysis of individual mouse plasma samples

A simple and convenient method to determine plasma cholesterol profiles in individual mouse plasma samples is not presently available. With commonly used methods, plasma samples from several animals in a study group must often be pooled and analyzed, usually by the fast phase liquid chromatography (FPLC) method. The Column Lipoprotein Profile (or CLiP) method described here is a modification of the FPLC method that provides a simple and convenient procedure for determining plasma lipoprotein cholesterol profiles in small sample volumes, allowing determination of profiles from individual animals rather than from pooled plasma. The CLiP method is reproducible; a human sample measured five times over several days produced coefficients of variation as follows: VLDL, 10.0%; LDL, 0.93%; and HDL, 2.51%. CLiP-derived total cholesterol values of five different human samples (with total cholesterol levels ranging from 198 to 263 mg/dL) differed from VAP-II by -1.88% +/- 2.57%. Linearity of differing concentrations for each of the lipoprotein classes was determined by measuring the same sample with different aliquot sizes. The linear regression from VLDL had an r value of 0.996, while LDL, HDL, and total cholesterol all had r values of greater than 0.999. We present a direct comparison of plasma cholesterol profiles from several mouse models with gene modification or expression of transgenic proteins. In conclusion, the CLiP method provides a simple, reliable, and reproducible procedure for determination of plasma cholesterol profiles from individual plasma samples with very low sample volumes, using readily available equipment and reagents.

Increased prevalence of smaller and denser LDL particles in Asian Indians

There is increasing evidence to believe that Asian Indians are at an increased risk of coronary heart disease (CHD), which cannot be attributed to the common risk factors. Individuals with small, dense LDL phenotype are also known to be at increased risk of CHD. Our objective was to examine whether the prevalence of smaller and denser LDL particles is increased in Asian Indians. Thirty-nine Asian Indians (22 men and 17 women), aged 25 to 45 years, were matched with 39 whites for age and gender. Cholesterol profiles of lipoprotein classes and LDL subclasses were measured using the Vertical Auto Profile-II (VAP-II) and LDL-VAP-II methods, respectively. Six LDL subclasses (LDL1 to LDL6) have been identified using the LDL-VAP-II, with LDL1 and LDL6, respectively, being the most and least buoyant subclasses. The prevalence of small, dense LDL type (subjects with major LDL subclass 5 or 6) was significantly higher in Asian Indians compared with white subjects (44% versus 21%; P<0.05). The relative position of the major LDL density peak (LDL-Rf) on 0 to 1 scale in LDL-VAP-II density gradient was also significantly decreased in Asian Indians (0.462+/-0.076 versus 0. 505+/-0.086; P<0.02), suggesting an increased LDL density. Furthermore, this increased prevalence of small, dense LDL type appears to be due to the increased triglycerides (TG) (r for LDL-Rf versus TG=0.681, P<0.001), with fasting insulin being one of the important determinants of TG (r for TG versus fasting insulin=0.572, P<0.001). In addition, fasting insulin was significantly increased in Asian Indians with small, dense LDL type compared with other Asian Indians, suggesting a significant role of insulin resistance in increasing the prevalence of small, dense LDL type. We conclude that the increased prevalence of small, dense LDL observed in Asian Indians might contribute to their increased CHD risk.

Mast cell stabilizing and lipoxygenase inhibitory activity of Cedrus deodara (Roxb.) Loud. wood oil

Volatile oil of C. deodara, administered orally at the doses of 50, 100 and 200 mg/kg body weight, significantly inhibited the pedal edema induced by compound 48/80 in rats. The oil significantly inhibited compound 48/80 induced degranulation of isolated rat peritoneal mast cells at concentrations ranging from 25-200 micrograms/ml. C. deodara wood oil also significantly inhibited the enzyme lipoxygenase at a concentration of 200 micrograms/ml. Thus, the anti-inflammatory activity of C. deodara wood oil could be attributed to its mast cell stabilizing activity and the inhibition of leukotriene synthesis.

Quantification of HDL2 and HDL3 cholesterol by the Vertical Auto Profile-II (VAP-II) methodology

Of the several existing methods for quantification of major subspecies of high density lipoprotein (HDL), HDL2 and HDL3, the methods based upon double precipitation are particularly useful for large-scale studies or for routine assay because of their high speed and low cost. The Vertical Auto Profile-II (VAP-II) method developed in our laboratory primarily for the direct single test measurement of cholesterol (C) in all major lipoproteins, including Lp[a] and IDL, is rapid, highly sensitive, and suitable for large-scale studies. Here we describe the modification of this procedure so as to be able to quantify both HDL2- and HDL3-C in addition to all major lipoproteins without any additional assay steps, time, or cost. The VAP-II procedure was validated by comparison with four other methods using plasma samples obtained from 35 healthy subjects: 1) HDL-VAP-II (a variation of the VAP-II procedure designed specifically to separate HDL subspecies); 2) dextran sulfate (DS)/Mg2+ double precipitation method performed at Northwest Lipid Research Laboratories (NWLRL), Seattle, WA; 3) 4-30% polyacrylamide-agarose (4/30 PAA) nondenaturing gradient gel electrophoresis (GGE); and 4) analytical ultracentrifugation (AUC), with both GGE and AUC performed at the Donner Laboratory, University of California at Berkeley. Both HDL2- and HDL3-C measurements by VAP-II correlated well with the measurements by all comparison methods (r for HDL3-C: HDL-VAP-II, 0.948; NWLRL, 0.947; GGE, 0.861; and AUC, 0.706, and r for HDL2-C: HDL-VAP-II, 0.867; NWLRL, 0.854; GGE, 0.885; and AUC, 0.721). The measurements of HDL2- and HDL3-C by the VAP-II method are reproducible, with the long-term between-rotor CV of 5.0% for HDL3-C and 9.0% for HDL2-C.

Identification and cholesterol quantification of low density lipoprotein subclasses in young adults by VAP-II methodology

Low density lipoprotein (LDL) particles are heterogeneous in size, density, and chemical composition; small, dense LDL may be more atherogenic than large, buoyant LDL. We have developed a rapid microscale method called LDL VAP-II (Vertical Auto Profile-II) for quantification of cholesterol in LDL subclasses. The method is based upon a short (1 h) single vertical spin density-gradient ultracentrifugation and on-line VAP-II analyzer. LDL VAP-II is rapid and reproducible. Using this method five LDL subclasses, designated as LDL-1 (most buoyant) through LDL-5 (most dense), have been identified in a population consisting of 195 medical students (ages, 22-29 years). The Rf (relative position of the major LDL peak in the density gradient; the higher the Rf value, the lower the peak density) was significantly positively correlated with cholesterol levels of high density lipoprotein (HDL) (r = 0.594), HDL3 (0.350) and HDL2 (0.625), and significantly negatively correlated with triglycerides (TG) (-0.355) and cholesterol levels of very low density lipoprotein (VLDL) (-0.386) and intermediate density lipoprotein (IDL) (-0.432). These results are consistent with those obtained by other investigators. The Rf value was significantly correlated with peak particle diameter as determined by non-denaturing gradient gel electrophoresis (r = 0.859). In a forward stepwise multivariate analysis comparing Rf with sex, VLDL, LDL, Lp[a], IDL, HDL3, HDL2, and triglyceride, only HDL2 remained in the model.

Quantification of cholesterol in all lipoprotein classes by the VAP-II method

We have developed a high resolution microvolume Vertical Auto Profile (VAP) method for the simultaneous measurement of cholesterol in all lipoprotein classes, including lipoprotein[a] (Lp[a]) and intermediate density lipoprotein (IDL). This method, designated as VAP-II, uses a non-segmented continuous flow (controlled-dispersion flow) analyzer for the enzymatic analysis of cholesterol in lipoprotein classes separated by a short spin (47 min) single vertical ultracentrifugation. Cholesterol concentrations of high (HDL), low (LDL), very low (VLDL), and intermediate (IDL) density lipoproteins, as well as Lp[a], are determined by decomposing the spectrophotometric absorbance curve, obtained from the continuous analysis of the centrifuged sample, into its components using software developed in this laboratory. Analysis by VAP-II is rapid and sensitive (as little as 40 microliters plasma is required per assay). The resolution of lipoprotein peaks is considerably enhanced in the present analyzer compared to the previous analyzer (VAP-I, which used the Technicon AutoAnalyzer); improvement is especially noticeable for Lp[a] and IDL. Total and lipoprotein cholesterol values obtained by VAP-II correlated well with the values obtained by Northwest Lipid Research Laboratories (NWLRL). VAP-II Lp[a] cholesterol values also correlated well with the Lp[a] mass values obtained by an immunoassay technique performed at NWLRL (r = 0.907). The reproducibility and accuracy of the method are within the requirements of the CDC-NHLBI (Centers for Disease Control-National Heart, Lung, and Blood Institute) Lipid Standardization Program.

Analysis of cholesterol in all lipoprotein classes by single vertical ultracentrifugation of fingerstick blood and controlled-dispersion flow analysis

This new, highly sensitive analytical system, based on controlled dispersion of the flowing sample, gives a rapid, continuous, and direct analysis for cholesterol in all lipoprotein classes, separated by single vertical-spin density-gradient ultracentrifugation. In this Vertical Auto Profile-II fingerstick system, designated VAP-IIfs, a narrow-bore Teflon coil serves as the reactor with no segmentation of the analytical stream by air bubbles, in contrast to the Technicon AutoAnalyzer used in the VAP-I method. Concentrations of high-, low-, intermediate-, and very-low-density lipoprotein cholesterol and lipoprotein(a) cholesterol are determined by decomposing the spectrophotometric absorbance curve for the continuous analysis of the centrifuged sample, with use of software developed in this laboratory. Total cholesterol is determined from the total area under the absorbance curve. For assaying total cholesterol, the CV between aliquots within a rotor ranged from 1.35% to 3.15%; the CV between rotors was 2.45%. Because only 18 microL of sample is required, VAP-IIfs can be readily adapted to analysis for lipoprotein cholesterol profiles in capillary blood samples. Total cholesterol values by VAP-IIfs for fingerstick and venous samples from 23 subjects agreed well: slope = 1.01 (SD 0.03), intercept = -21 (SD 51) mg/L, Sy/x = 50 mg/L, and r = 0.992. Results by VAP-IIfs also correlated highly with results for duplicate samples analyzed at the Northwest Lipid Research Laboratories.