Biomedical subjects

A V Arutjunyan

Publications and source records attributed to A V Arutjunyan.

6 recordsLinked to original sources

PubMed2003

Low leucocyte myeloperoxidase activity in patients with multiple sclerosis.

The gene for myeloperoxidase (MPO) has been implicated in multiple sclerosis (MS). By measuring H(2)O(2) dependent oxidation of 3,3'5,5'-tetramethylbenzidine with spectrophotometry the authors investigated MPO activity in peripheral blood leucocytes from 42 patients with MS (12 with secondary progressive MS, 17 with primary progressive MS, and 13 with relapsing remitting benign MS) and 32 healthy controls. Leucocyte MPO activity was significantly lower in patients with benign MS (mean (SEM) 0.086 (0.029) U/mg protein; p<0.01), secondary progressive MS (0.038 (0.009) U/mg protein; p<0.001), and primary progressive MS (0.057 (0.016) U/mg protein; p<0.001) compared with healthy controls (0.322 (0.053) U/mg protein). These data suggest that low MPO, which may be genetically determined, plays a part in MS pathogenesis.

Adult↗

PubMed2001

Cooling garment treatment in MS: clinical improvement and decrease in leukocyte NO production.

Ten heat-sensitive patients with MS were randomly allocated in a cross-over study to wear a cooling garment for 60 minutes at 7 degrees C (active cooling) and 26 degrees C (sham cooling). In contrast to sham cooling, active cooling improved fatigue and postural stability with eyes closed and muscle strength. There was no decrease in tympanic temperature, but active cooling was associated with a 41% decrease in mean leukocyte nitric oxide (NO) production (p = 0.004). This effect on NO could be relevant because it blocks conduction in demyelinated axons.

Adult↗

PubMed2001

Melatonin increases both life span and tumor incidence in female CBA mice.

From the age of 6 months until their natural deaths, female CBA mice were given melatonin with their drinking water (20 mg/l) for 5 consecutive days every month. Intact mice served as controls. The results of this study show that the consumption of melatonin did not significantly influence food consumption, but it did increase the body weight of older mice; it did not influence physical strength or the presence of fatigue; it decreased locomotor activity and body temperature; it inhibited free radical processes in serum, brain, and liver; it slowed down the age-related switching-off of estrous function; and it increased life span. However, we also found that treatment with the used dose of melatonin increased spontaneous tumor incidence in mice. For this reason, we concluded that it would be premature to recommend melatonin as a geroprotector for long-term use.

Aging↗

PubMed2001

Effects of pineal peptide preparation Epithalamin on free-radical processes in humans and animals.

OBJECTIVES: The review on our own data on the effect of the pineal peptide preparation Epithalamin on free radical processes in rodents and humans is presented in this paper. RESULTS: The activity of Cu, Zn-superoxide dismutase (SOD) was found decreased in the brain of aged rats (30 months old) by 46.8% as compared to young animals. Concentration of Schiff's bases in the brain also went down with age (by 13.6%), while the level of dien conjugates (DC) and protein peroxidation (PPO) remained unchanged. General antioxidation activity (AOA) in the brain also remained stable with age. The liver of aged rats showed significant increase of Schiff's bases (by 27.1%) and PPO products (by 109.2%) and considerable decrease of SOD activity. The level of DC and general AOA in the liver remained unchanged with age. Considerable elevation of protein and lipid peroxidation products contents was registered in the blood serum of aged rats. At the same time, general AOA and SOD activity remarkably decreased. The results obtained evidence from both significant age-related alterations in the activity of free radical processes in animal organism and organic peculiarities of their dynamics. Application of peptide drug epithalamin suppressed significantly the intensity of peroxide chemoluminescence in the blood serum (2.8-fold) and lipid peroxide oxidation (LPO) expressed in the considerably decreased DC contents (4,1-fold). The contents of Schiff's bases showed only a tendency towards decrease (by 14.4%, p > 0.05) and PPO level remained unchanged. Epithalamin administration was followed by considerable (by 36.6%, p < 0.01) increase of general AOA and increased SOD activity (by 19.7%) in males. Epithalamin decreased significantly the contents of conjugated hydroperoxides and ketodienes in tissues of D.melanogaster females, increased catalase activity in drosophila males and females, and increased SOD activity in males of D.melanogaster by 41%. Humans reveal significant age-related decrease of antioxidation defence indices. CONCLUSION: Epithalamin administration to patients with age-related pathology eliminates imbalance in prooxidation and antioxidation systems.

Adult↗

PubMed2001

Disturbances of diurnal rhythms of biogenic amines contents in hypothalamic nuclei as an evidence of neurotropic effects of enterotropic carcinogen 1,2-dimethylhydrazine.

OBJECTIVES: Our data on the contents of norepinephrine (NE), dopamine (DA) and the metabolite of serotonin 5-hydroxyindoleacetic acid (5-HIAA) measured in the suprachiasmatic nuclei (SCN), preoptic area (PA) and median eminence (ME) of hypothalamus of rats after single subcutaneous injection of 1,2-dimethylhydrazine (DMH) as well as the effect of this carcinogen on formation of reactive oxygen species (ROS) in the PA are presented in this paper. RESULTS: Diurnal changes of DA in all studied brain structures and of NE in the PA have been observed in the control group. Their morning levels were higher than evening ones. Rhythms of 5-HIAA in the SCN and diurnal changes of ROS formation have been shown to have contrary changes in control. Both the morning (11 a.m.) and evening (11 p.m.) subcutaneous administration of DMH at the dose of 21 mg/kg of body weight resulted in changes of all rhythms observed in control. In some cases a phase shift was found, in others the rhythms of neurotransmitters and ROS formation disappeared entirely. CONCLUSION: The data obtained confirm the idea of dopaminergic and serotoninergic systems taking part in mechanisms of a response of the hypothalamic nuclei to non-photic stimuli. It is suggested that the effect of DMH on the content and diurnal rhythms of neurotransmitters in the hypothalamic structures under study is due to its affecting activities of the enzymes of biogenic amines synthesis, synaptic transmission, melatonin synthesis and secretion rhythms. The change in ROS formation that is caused by administration of DMH is likely to be due to a disturbance of diurnal rhythms of neurotransmitters that are one of the sources of formation of free radicals in the brain.

1,2-Dimethylhydrazine↗

PubMed1999

Functional and biochemical criteria for investigation of brain development disorders.

Functional state and creatine kinase (CK) activity in the amniotic fluid and blood of anencephalic fetuses was studied in the second trimester of pregnancy with the following pathomorphological investigation of the state of their CNS to reveal possible markers of development disorders. The extent of neurological disorders in newborn infants was retrospectively compared with data from functional studies of components of a biophysical profile (motor-cardiac reflex, heart rhythm oscillations, respiratory movements) and with CK activity in the amniotic fluid and blood of fetuses with hemolytic disease and fetuses of diabetic mothers and normal mothers in the third trimester of pregnancy. The results revealed informative indices of fetal CNS developmental disorders in the prenatal period that are of importance for predicting a prognosis of the extent of neurological disorders in newborn infants. These results will allow the establishment of criteria for evaluation of fetuses to reveal possible disorders in the formation of the CNS.

Amniocentesis↗