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Biomedical subjects

M Nikolova

Publications and source records attributed to M Nikolova.

At least 91 records · Page 5Linked to original sources
PubMed1976

[Effect of adepren on the behavior and brain catecholamines of rats in an open field setup].

The authors carried out experimental studies with the Bulgarian preparat on Adepren on the behaviour of rats in open field procedure together with parallel electroencephalographic studies and examined the changes in the content of cerebral catecholamines during acute and chronic administration. The preparation after single application had depresive effect on both components of the motor activity: horisontal and vertical. The horizontal component of the motor activity surpassed the norm with almost 20% at the end of the experimental period after chronic administration. There was desynchronizing effect in the KEG recordings. Adepren after acute and chronic application elevated significantly the level of noradrenaline and dopamine in the brain. The obtained results gave a foundation to the authors to suggest that the examined preparation and maoinhibiting effect.

Aminoquinolines↗
PubMed1976

[Effectiveness of a Bulgarian vaccine against Marek's disease in broilers].

Studies were carried out to establish the effectiveness of the immunization of broilers against Marek's disease using a Bulgarian vaccine produced with strain C3-1 of a turkey herpes virus. The experiments were done under the conditions of an industrial poultry dressing combine with a total of 52,450 day-old hybrid birds vaccinated at the rate of 1000 plaque-forming units (PFU), 39,450 birds vaccinated with 500 PFU each, and 91,564 unvaccinated control birds. After the 60-63-day fattening period was over the average value of the mortality rate was 2.17 per cent and 2.48 per cent in the vaccinated birds and the controls, respectively. The vaccinated groups of birds showed also a comparatively higher weight gain--by 73 g, on an average, recorded prior to slaughter--as against the control groups. No differences were found in these indices between the groups immunized with 1000 and 500 PFU. In a laboratory test with 255 birds divided into four groups immunized with 100, 500, 250, PFU and controls, challenged in the third week with a pathogenic herpes virus it was found that up to the 6th month the first two groups developed Marek's disease as accounted by 1.65 per cent of the birds, while those vaccinated at the rate of 250 PFU were not properly protected, showing a higher morbidity rate--9.23 per cent. It is concluded that the Bulgarian vaccine--strain C3-1--confers solid immunity in a dose of 500 PFU, the vaccination of broilers being economically profitable.

Animals↗
PubMed1976

[Testing the preventive properties of polyvalent inactivated vaccine (IBR, PI-3, Adenovirus 1,3) at a cattle-breeding farm].

Tested was an inactivated polyvalent vaccine. It was shown to produce virus-neutralizing antibodies against the respiratory viruses in high titers. The vaccine proved highly immunogenic, reactogenic, and harmless in doses of 2,3,5,7, and 10 cm3 for 30-45-day-old calves and pregnant cows in their 7th or 8th month of pregnancy. The morbidity rate among the unvaccinated calves ranged from 51 to 66 per cent, and among the vaccinated ones it was from 0 to 5 per cent on the four farms studied. The abortions caused by the IBR vicontrol was cows about 17 per cent, and with the vaccinated ones it was 1.14 per cent. Calves born by untreated control cows contracted respiratory virus infections (76 per cent), while calves from vaccinated cows did not. When there was an acute virus respiratory disease on the farms all calves were treated with a hyper-immune serum against respiratory viruses, and after recovery of the herd vaccinations and revaccinations of all calves were carried out. Discussed is the problem of the protection properties of the vaccine in the case of pregnant cows and its advantages as compared with the live vaccines in order to discontinue the transmission of live viruses onto the industrial cattle-breeding farms.

Adenoviridae Infections↗
PubMed1976

[Effectiveness of Deptavac HVT vaccine on broiler parents during the egg-laying period].

Experiments were carried out with 4 flocks-a total of 16,940 layers of the White Plymouth Rock breed (10,865 vaccinated and 6075 untreated) and 3000 cocks of the White Cornish breed (502 vaccinated and 1498 untreated). The test birds had been vaccinated at the age of one day. The average month mortality rate among the vaccinated birds was 1.5 per cent, and among the untreated it was 4.9 per cent; for the whole exploitation period these values were 15.35 and 47.17 per cent, respectively. Mortality rate caused by Marek's disease and lymphoid leukosis (specific mortality) in the test groups was 4 times lower as compared with that of the control groups (11.54 as against 44.75 per cent), and the coefficient of epizootiologic effectiveness was 74.4 per cent. Considerable variation was established in the intensity and dynamics of the epizootic process with the vaccinated and unvaccinated birds, on the one hand, and the layers and cocks, on the other. White Cornish cocks proved more resistant to Marek's disease and more sensitive to lymphoid leukosis, while the layers of the White Plymouth Rock breed were more sensitive to Marek's disease and more resistant to lymphoid leukosis. These differences could explain the dynamics peculiarity of the specific mortality exhibited by layers and cocks. The egg-laying capacity of a "forage" layer up to the age of 62 weeks of age in the test flocks was 9.2 (7.2) per cent higher than that of the untreated layers. In exploitation up to the 70th week of age each test layer gave 23 eggs more as compared to the untreated. It is calculated on the basis of the experimental data that a total of 55,200 eggs and more could be obtained from 6000 parental birds vaccinated against Marek's disease during a 10-month laying period.

Age Factors↗
PubMed1975

[Study of immunity in coccidiosis in chickens experimentally infected with Marek's disease].

The immunity was studied against coccidiosis in birds that had preliminary been infected with Marek's disease. Results showed that birds infected with Marek's disease are unable to build up stable immunity against an oocyst infection of Eimeria tenella. The rate of mortality due to Marek's disease in birds infected with the virus of Marek's disease and additionally infected with oocysts of E. tenella was higher as compared with that in birds that were infected only with the virus of Marek's disease.

Animals↗