Improved resolution of liver and bone alkaline phosphatase isoenzymes using wheat germ lectin or neuraminidase pretreatment with the introduction of some technical modifications

This study aims to establish a routine reliable electrophoresis method with improved separation of liver and bone alkaline phosphatase isoenzymes, which allows for their quantitation. Modifications of the already available techniques will also be studied. Samples were collected from patients with liver diseases [n = 26], with bone diseases and from children [n = 24] and from pregnant females in the third trimester [n = 10]. Control sera containing liver and intestinal isoenzymes were also used. Samples were subjected to liver function tests, calcium and phosphorus determination, cellulose acetate electrophoresis : ordinary, with germ wheat lectin and with neuraminidase pretreatment. Agarose gel electrophoresis was done with and without lectin. Samples were also subjected to sequential heat inactivation. Results showed that cellulose acetate electro-phoresis gave better separation of liver and bone fractions when done with germ wheat lectin or when samples were pretreated with neuraminidase. Several modifications were suggested to improve the technique. Agarose gel affinity electrophoresis [i.e., with lectin] gave the best separation of liver and bone isoenzymes into sharply defined bands. Sequential heat inactivation was tedious and needed scrupulous control of time and temperature. It overestimated the liver isoenzyme due to inclusion of biliary and intestinal fractions in its estimation. Excellent correlation was found between the different methods used for both bone and liver isoenzymes, Biliary isoenzyme was best separated by ordinary electrophoresis whether on cellulose acetate or agarose gel. Placental isoenzyme separation required preheating the sample at 65°C for 10 minutes to destroy the bone fraction which had the same migration mobility as placental isoenzyme. It was concluded that agarose affinity gel electrophoresis gave the sharpest and clearest separation of liver and bone fractions. On the other hand, cellulose acetate electrophoresis was less expensive, more sensitive and precise. Both methods were more suitable than the heat separation analysis method

Apolipoprotein B and other lipid parameters in coronary atherosclerosis

92 patients undergoing coronary angiography, in the cardiology Department of Ain Shams University Hospital. were chosen. According to the results of the angiogram, patients were divided into control group, with normal patent coronary arteries and patient group with atherosclerosis in one or more coronary arteries. To exclude the effect of non lipid risk factors, the paired "t" test was applied to match pairs of patients and controls. Results showed that apo B, TC, LDL-C and B lipoprotein were significantly higher in patient group than in control group; whereas, HDL-C, and a lipoprotein were significantly lower. The ratios of TC/HDL-C and LDL-C/HDL-C were significantly increased in the patient group. To assess the relation of the studied parameters to the severity of the condition, the patient group was further subdivided into a group of moderate atherosclerosis, with lesions in one or two coronary arteries and severe atherosclerosis with lesions in three or more coronary arteries. Comparing both groups together, and to the control group, it was found that apo B was the only parameter, which showed significant difference between both groups. We concluded that apo B had a much better predictive value in relation to CAD risk. It is the only parameter, which is related to the severity of the atherosclerotic process

Comparison between two methods for measuring serum low density lipoprotein cholesterol

Two methods for low density lipoprotein cholesterol [LDL-C]. estimation were compared at different triglycerides [TG] levels. These were the quantitative determination by Helena cellulose acetate electrophoresis methods and the indirect calculation using Friedwald formula. Eighty fasting samples were selected and classified into 4 groups according to their TG levels. LDL-C was determined in each sample by both methods. Strongly significant correlation coefficients, between the 2 methods were obtained at normal, slightly, and moderately increased TG levels [r = 0.99, 0.97 and 0.94 respectively]. At TG levels >350 mg/dl the correlation became much weaker [r =0.77]. Thirty samples at different TG levels, were examined in duplicate for accuracy and precision. The electrophoretic quantitation of LDL-C was, much more precise [CV = 2.6%] than the indirectly calculated one. The latter depends on the imprecision of methods used in measuring total cholesterol, TG and HDL-C by precipitation method [CV = 2.7%, 3.8% and 8.5% respectively]. Paired t test showed no significant difference between LDL-C values obtained by both methods [P>0.05] However, in all cases of hypertriglyceridemia, the calculated LDL-C values showed constant insignificant lower values [6 - 12% lower] which might be sufficiently erroneous to cause misinterpretation of hypercholesterolemia at the critical LDL-C levels when medical interventions required. We recommended using the Fridewald formula as a screening test for LDL-C estimation and the electrophoresis method at TG levels> 350 mg/dl, LDL-C levels> 200 mg/dl or when abnormal lipoproteins are present