Irina Chernova works as a scientific researcher at the Insitute of Macromolecular Compouds of Russian Academy of Sciences since 1972 in the field of isolation and purification of biologically active substances. She obtained her PhD in 1985 concerned with isolation of microbial sialidase. In 1998 she spent a year at Bath University (UK) as a visiting scientist. She has published 38 papers. The field of interest is the role of sialic acids in the regulation of intercellular interactions and occurrence of ABO-polymorphism.
Biological recognition mediated by sugar chains is an important mechanism in multicellular organisms. The N-linked sugar chains of glycohormones such as hCG may play a crucial role in their biological function. As with many specific receptors, the recognition site of hCG comprises terminal sialic acid. The aim of this work is the study of the number of sial-containing groups of natural hCG excreted by pregnant women with different blood groups. No discussion of blood group specificity of glycoprotein hormones has been found in literature and commercially available hCG-preparations are purified from urine of donors pooled regardless of their blood group. It is suspected that hCG in these preparations is not fully effective. The ion-exchange and gel chromatography for hCG purification from pregnancy urine of various blood group donors was performed (a porous carboxylic resin and Sephadex G-100 were used). The purified hCG-preparations were analyzed with HPLC. The highly purified hCG-preparations from various blood group donors were shown to differ in their sialic acid content. This is potentially important for dosage of hCG-preparations for clinical use. In the process of dose evaluation of chimiotherapeutic action of hCG the blood group of a patient should be taken into account. The optimal solution may be in differentiated use of donors’ urine during the process of hCG isolation. We studied as well the correlation between the concentrations of free and bound sialic acids in highly purified hormone preparations of various blood group donors. The level of free sialic acids was checked which could be interpreted as measure of tissue sialidase activity.
Rakan alqurainees, a medical student who is expected to graduate from medical school of Hail University, Saudi Arabia, by the end of June, 2016. He is very interested in the research field regarding the relationship between obesity and cardiovascular diseases. Currently he is working on research paper about the relationship between sex hormones and the cardiac autonomic dysfunction in obese individuals.
Introduction: Obesity has been associated with hypothyroidism and cardiac autonomic dysfunction. The present study aimed to investigate whether cardiac autonomic dysfunction in young obese males might be related to an underlying thyroid disturbance. Materials and Methods: On the basis of body mass index (BMI), 40 participants were grouped into normal weight group (NW; BMI= 18.5-25 kg/m2; n = 15), over weight group (OW; BMI= 25-29.9 kg/m2; n = 12) and obese group (OB; BMI ≥ 30 kg/m2; n = 13). Electrocardiogram was recorded using PowerLab system and the time and frequency domain measures of heart rate variability (HRV) were calculated. Fasting blood samples were drawn for measurement of serum thyroid stimulating hormone (TSH), total thyroxin (TT4) and total triiodothyronine (TT3) concentrations. Results: The levels of TSH, TT4 and TT3 were not significantly different between the groups. The frequency domain HRV parameter reflecting parasympathetic tone (high-frequency normalized units, HFnu) was significantly reduced in OB group. The parameters which reflect sympathetic activation (Heart rate, low-frequency normalized units; LFnu and the LF/HF ratio) were significantly increased in the OB group. HFnu was significantly and negatively correlated with BMI, waist hip ratio and body fat percentage, whereas LFnu and LF/HF ratio were significantly and positively correlated with the above mentioned parameters. No significant relationships were noted between the HRV parameters and the levels of TSH or thyroid hormones. Conclusion: Cardiac autonomic dysfunction in young obese adult males is not linked with underlying thyroid disturbance.