Abstract

         Background and Objectives: Concentration low-density lipoprotein (LDL) is one of the strongest indicators of atherosclerosis and predicts the diagnosis of cardiovascular diseases. LDL measurement accuracy is very important. LDL can be measured directly, such as enzymatic and nephelometry methods or can be calculated using Friedewald's formula. Despite the development of enzymatic methods and LDL nephelometry still in most laboratories is calculated using Friedewald's formula. The aim of this study was an investigation of correlation coefficient between two methods of measuring LDL- cholesterol levels.

         Methods: This descriptive cross-sectional study, performed on the 1141 patients. Cholesterol, triglycerides, HDL, LDL all patients assayed by enzymatic method. For patients with triglyceride levels of less than 400 mg/dl had LDL levels were calculated by Friedewald's formula. Normal levels of LDL/HDL ratio of less than 3.5 were considered.

          Results: Of the 1141 patients participating in this study, 38.3 % men and 61.7 % women. The mean patient age was 46.3 ± 16.1 years. Mean serum cholesterol, triglycerides and HDL were 177.9 ± 41.1, 132.9 ± 73.2 and 45.8 ± 13.2 mg/dl, respectively. Average direct and calculated LDL concentration was 82.1 ± 23.1 and 105.5 ± 35.8, respectively. The direct measurement of LDL, LDL/HDL levels in 97.1% of cases was normal, while 85.1 % of the calculation of LDL were normal. Pearson correlation coefficients were obtained by two methods: 0.869 (p <0.001).

         Conclusion: Despite the favorable correlation between two methods of measurements of LDL, the results of a calculation method is more than direct method. This can have a negative impact on the judgment of the treating physician.

           Key words: LDL, Enzymatic Method, Friedewald's Formula.

ABSTRACT

      Background and Objective: Ochratoxin is a fungal toxin produced by Penicillium verrucosum and some Aspergillus species. Ochratoxin is usually found in grains, cereal products and also animal feed of livestock. The aim of this study was to measure the level of Ochratoxin in pasteurized milk samples of Golestan Province, Iran.

      Methods: Overall, 38 milk samples were collected from East and West of the Golestan province in accordance with standards 326 and 419 of the Institute of Standards and Industrial Research of Iran. The level of Ochratoxin was measured by ELISA method.

      Results: The mean level of Ochratoxin A in 20 raw milk samples collected from the West of the Province was 3.32 ± 3.76 ng/ml. The mean level of Ochratoxin A in 18 raw milk samples collected from the East was 6.02 ± 4.42 ng/ml. Ochratoxin A levels in most samples were higher than the limits established by the European standards.

      Conclusion: Based on the results of this study, Ochratoxin level of 84.2% and 52.6% of the samples from the West and East of the province are higher than the allowed limits (2 ng/ml), respectively.

      

ABSTRACT

       Background and Objective: The association of Triglyceride/High Density Lipoprotein-Cholesterol (TG/HDL-C) ratio with fasting serum insulin, which is an alternative method of insulin resistance (IR) measurement, is well-recognized. Thus, the measurement of TG/HDL-C ratio is useful to determine both IR and dyslipidemia, which itself is a characteristic of individuals with IR. Therefore, this study aimed to investigate the relationship between TG/HDL ratio as an indicator of IR, with different fasting blood glucose levels.

      Methods: This case-control study was performed on 343 volunteers with no history of diabetes or use of blood glucose-lowering medications and fasting blood sugar (FBS) levels of less than 126 mg/dl. After sampling, the subjects were divided into three groups based on their FBS level. First group included healthy subjects with FBS of less than 100 mg/dl. Second group consisted of subjects with impaired fasting glucose (IFG) and FBS of 110-100 mg/dl and a third group including those with impaired glucose tolerance (IGT) and FBS of 110-125 mg/dl.

       Results: The amount of TG/HDL-C ratio was 3.8 ± 2.8, 4.0 ± 2.1 and 5.4 ± 3.8 for the healthy group, individuals with IFG and IGT, respectively. The TG/HDL index was significantly different among the tested groups with no significant difference between healthy subjects and subjects with IFG. Moreover, there was a statistically significant difference between the IGT and IFG groups with healthy individuals.

       Conclusion: Considering the significant increase of the TG/HDL ratio in groups with impaired glucose, using this index can be helpful in evaluation of glycemic disorder.

  

ABSTRACT

       Background and Objective: Measurement of amino acids is an important tool for metabolic studies and evaluation of patients’ clinical condition. The aim of this study was to analyze the plasma amino acids using reverse phase high performance liquid chromatography techniques (RP-HPLC) with pre-column derivatization by o-phthalaldehyde (OPA) in combination with 3- mercaptopropionic acid (3-MPA).

       Methods: Overall, 107 neonates and babies suspected of having metabolic disorder were enrolled in this study. The level of amino acids in plasma samples was analyzed within 65 minutes by HPLC with pre-column derivatization by OPA/3-MPA. This was a gradient RP-HPLC method that was performed using two solvents with a ratio of methanol and sodium acetate. L-norvaline internal standard was used as the reference peak for amino acids. Standard mixture of amino acids was used to determine the concentrations of amino acids.

        Results: According to the values of coefficient of variation obtained for each amino acid, the results indicated a good chromatographic separation of amino acids by this method. The use of OPA/3-MPA derivative reagent increased the efficiency and resolution of amino acids chromatographic separation.

      Conclusion: Due to simple preparation and accurate assessment, determination of plasma amino acids using OPA/3-MPA derivatives and RP-HPLC is a suitable method in many clinical samples.

ABSTRACT

         Cardiovascular disease (CVD) is one of the most important causes of mortality worldwide. Several risk factors have been proposed to be associated with CVD. The main risk factors include family history, smoking, hypertension, history of diabetes, hyperlipidemia and obesity. However, new factors have been recently proposed to be associated with CVD. These include blood homocysteine, fibrinogen, plasma factor VII activity, lipoprotein (a) and several other factors. Nowadays, the role of homocysteine in the development and exacerbation of several diseases has been demonstrated. Extensive studies have been performed on the role of homocysteine in diabetes, preeclampsia, depression, Alzheimer's disease and multiple sclerosis. Homocysteine level increases with age. Moreover, absorption of micronutrients, especially vitamin B12, decreases in old age that could cause a further increase in homocysteine level. On the other hand, elasticity of blood vessels decline with aging, and increased levels of homocysteine accelerate atherosclerosis. The sum of these processes highlights the role of homocysteine in the development and exacerbation of several diseases.

         Keywords: Homocysteine, Cardiovascular Disease, Diabetes, Preeclampsia, Depression, Alzheimer's Disease.

ABSTRACT
        Background and Objectives: The unfavorable lipid profile in obese individuals is associated with high incidence of various diseases including cardiovascular disease, hypertension, etc. Dieting for weight loss and physical activity are among the most important factors affecting the serum lipid profile. The aim of this study was to compare the effect of diet with and without physical activity on body mass index and serum lipid profile of obese women.
      Methods: This clinical trial was performed in 2011 on 39 obese women referred to a weight loss and nutrition counseling center. Subjects were randomly divided into an active group (diet and exercise) and inactive group (diet without exercise). Blood sampling was done before the intervention and two months after the intervention. Data was analyzed using SPSS-16 and t-test.
       Results: Mean level of triglyceride reduced significantly in both groups. Mean level of cholesterol and low-density lipoprotein decreased significantly only in the active group. The Mean level of high-density lipoprotein in the two groups had no significant difference.
Conclusion: The results indicate that dieting for weight loss along with short-term physical activity improves serum levels of cholesterol and low-density lipoprotein, but does not affect serum HDL level.
        Keywords: Diet, Exercise, Triglyceride, Cholesterol, LDL, HDL.