APO B 3' HVR polymorphism in healthy population: relationships to serum lipid levels

We have analyzed allele frequency distribution at the hypervariable locus 3' to the apolipoprotein B gene in a healthy population sample (241 women and 246 men) from the Belgrade area. The bimodal distribution of sixteen different hypervariable region (HVR) alleles and the heterozygosity index (average 0.76) in both samples are similar to ones reported for other Caucasian populations. However, we found the hypervariable element containing 34 repeats-HVE34 allele to be the most common one in both female and male samples, and that there was a lower frequency of the HVE>36 alleles. For further analysis of 3'HVR allele frequency and its possible association with serum lipid levels, all HVR alleles were grouped into five main types (HVE<32, HVE32, HVE34, HVE36, and HVE>36), and the samples were divided into lipid quartiles. We found that (1) apo B gene 3'HVR polymorphism is associated with variation of normal lipid levels in males, (2) HVE32 alleles are associated with decreased serum levels of total cholesterol, LDL cholesterol, and triglycerides, and (3) HVR genotypes containing HVE34 and HVE36 alleles are associated with elevated serum levels of total cholesterol, low density lipoprotein (LDL) cholesterol, and triglycerides.

Hepatitis C virus RNA testing by nested PCR in blood preparations in Yugoslavia

Patients receiving any kind of human blood preparations are in permanent danger of any infection including hepatitis C (HCV) infection. Testing for the presence of HCV in blood preparations is one of the steps towards safe medical treatment. One of the approaches for this testing is a detection of HCV nucleic acid. In this paper we describe a simple method for isolation of HCV RNA from blood preparations and control of HCV RNA presence in 19 intravenous and intramuscular products, manufactured in the National Blood Transfusion Institute in Belgrade. RT-PCR was performed according the rules saving RNA. Primers were located in 5' conserved region. Seven out of 19 batches of gamma-globulin, albumin, anti-tetanus and anti-rabies immunoglobulin preparations were found to be HCV RNA positive. For the time being, the PCR method is too expensive for routine HCV RNA testing of hundreds of blood donors per day. Serological screening test of blood donors and nested PCR testing for HCV RNA in blood preparations could be an efficient combination of tests in prevention of posttransfusion hepatitis C.

Genetic variation at the apoB 3'hypervariable region in a Serbian population

We investigated common length polymorphism caused by a variable number of tandem repeats in the hypervariable region located at the 3' end of the human apolipoprotein B gene in 696 Serbian (Belgrade area) unrelated individuals of both genders. After using the polymerase chain reaction to amplify this polymorphic region, 17 different alleles, containing 22-54 repeats, were distinguished. The bimodal distribution and the heterozygosity index (average 0.71) obtained in both genders are similar to those reported for other Caucasian populations. However, the HVE34 allele was found to be the commonest in both female and male samples. There was also a lower frequency of the HVE > 36 alleles than in other Caucasian populations studied.

Study of apoB gene signal peptide insertion/deletion polymorphism in a healthy Serbian population: no association with serum lipid levels

The apolipoprotein B (apoB) signal peptide polymorphism was studied in unrelated healthy individuals. A total of 232 women and 222 men were analyzed separately. The relative frequencies of Del allele in women and men were 0.42 and 0.37, respectively. More heterozygous individuals were detected in comparison with other populations, using a modified silver staining method on polyacrylamide gel for visualization of Ins and Del alleles. There was no statistically significant difference in mean lipid levels adjusted for age, BMI, smoking habit and blood pressure between the three Ins/Del genotypes in both samples (ANOVA). Therefore, no differences were shown in the genotype frequency distribution throughout the lipid quartiles.

[Detection of the presence of the hepatitis C viral genome in immunoglobulin preparations using RT-PCR]

Contemporary methods of molecular genetics were used to investigate the presence of hereditary matter, i.e., virus hepatitis C genome in immunoglobulin preparations of the Institute for blood transfusion of the Republic of Serbia. ELISA test in immunoglobulin preparations indicated the presence of antibodies to an antigen of hepatitis C virus. After RNA isolation and reverse transcription (RT), double reaction of in vitro DNA amplification (PCR) was done using two pairs of oligonucleotide. After several repeated tests and positive control from blood of the diseased it was concluded that neither of 11 investigated immunoglobulin preparations contained the nucleic acid (RNA) of the HCV origin, that meant that all preparations could be used with no danger of virus hepatitis C infection. Regarding the current experience in relation to the use of PCR for testing of contamination by hepatitis C virus in preparations from human blood, that are used in the therapy of various conditions and diseases, it is recommendable to use this method due to its sensitivity and specificity.

Apolipoprotein B gene DNA polymorphisms (EcoRI and MspI) and serum lipid levels in the Serbian healthy population: interaction of rare alleles and smoking and cholesterol levels

The frequency of restriction fragment length polymorphisms (RFLPs) of the apolipoprotein B (apo B) gene, detected by EcoRI and MspI, and their influence on serum lipids were studied in a total of 239 healthy subjects from the Belgrade area. The influence of interaction between different genotypes and smoking was also studied. The relative frequency of both rare R2 and M2 alleles (lacking the cutting site) was similar to that reported in other groups of Caucasians (0.16 and 0.11, respectively). No association was observed between the apo B genotypes and serum lipid levels adjusted for age, body mass index, and blood pressure either in the whole sample or in either women or men. When smokers and non-smokers were considered separately, smoking had a significant impact on total cholesterol variability in all individuals with genotype M1M2 and high density lipoprotein (HDL) cholesterol variability in women with genotype R1R2. The presence of the rare alleles of these two polymorphisms in smokers was associated with lower lipid levels in the whole sample and in both women and men analyzed separately, except for an increase of HDL cholesterol level in male smokers, heterozygous for EcoRI polymorphism (R1R2).

Implications of interscapular brown adipose tissue removal and sucrose overfeeding on the sympatho-adrenal activity and metabolic responses

1. The influence of sucrose overfeeding on the sympatho-adrenal (SA) and metabolic responses was studied in sham-operated (SHAM) rats and in those with interscapular brown adipose tissue (IBAT) removed. 2. Sucrose feeding significantly increased the SA activity, mobilized the free fatty acids (FFA), but did not change glucose homeostasis in sham-operated rats. 3. IBAT removal in control rats fed a stock diet modified the SA activity whereas the levels of both blood glucose and serum FFA were unchanged. 4. However, sucrose in rats void of IBAT potentiated the activity of sympathetic nervous system only and prevented the FFA rise, which is seen in sham-operated sucrose fed rats indicating that the enhanced level of serum FFA in these animals principally originated from the IBAT.

Sympatho-adrenal activity and metabolic responses in fasted rats--the role of interscapular brown adipose tissue

1. Sympatho-adrenal (SA) and metabolic responses to fasting were studied in sham-operated (SHAM) rats and in those with interscapular brown adipose tissue (IBAT) removed. 2. Fasting significantly increased adrenaline (A) excretion and serum free fatty acids (FFA), but decreased noradrenaline (NA) excretion and blood glucose level in SHAM rats. 3. IBAT removal did not change metabolic responses while it markedly altered the SA activity. Fasting in animals void of IBAT potentiated the activity of adrenal medulla, inhibited the FFA rise and prevented glucose reduction, which is normally observed in SHAM-fasted rats. 4. Results suggest the significance of IBAT in the regulation of the blood level of energy substrates in fasted rats and in maintaining the basal level of NA excretion.