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Biomedical subjects

G Vasilev

Publications and source records attributed to G Vasilev.

13 recordsLinked to original sources
PubMed2006

Needle exchange use, sexual risk behaviour, and the prevalence of HIV, hepatitis B virus, and hepatitis C virus infections among Bulgarian injection drug users.

At a time when the rates of HIV, hepatitis C virus (HCV), and hepatitis B virus (HBV) infections have risen among injection drug users (IDUs) in other countries in the region, little is known about the prevalence of these infections among Bulgarian injectors and about their sexual risk behaviours. IDUs (n = 773) in a community-based needle exchange programme (NEP) and two major drug treatment facilities in Sofia completed a structured interview and were tested for HIV, HBV, and HCV antibodies. While HCV prevalence in the sample was 73.9%, HBV and HIV prevalence was low -6% and 0.5%, respectively. Having more than 10 sexual partners, having sex with someone with hepatitis C or another IDU, and never using a condom with another IDU were common among those who were recruited through NEP. As 40% of the IDUs reported using NEP, it appears that needle exchange provides an opportunity to reach high-risk populations and prevent sexual transmission of blood-borne pathogens.

Adult↗
PubMed1986

[Methods for synchronizing estrus and selecting recipient heifers in embryo transplantation].

Threefold thorough gynecological investigations were carried out with a total of 108 heifers with normal cycle, which remained uninseminated--in their choice, treatment with hormonal preparations, and transplantation of embryos, reducing their number up to 76. With the first test group of 35 heifers estrus was synchronized with implants, containing 3 mg norgestomet each. On the 9th day these were removed, and the heifers were injected with 500 IU PMSG (Intervet) each. The animals of the second test group (73 in number) were injected with 7.5 mg prostaglandin F2-alfa at 11-day intervals. The conception rate was 31 per cent higher with heifer-recipients treated with norgestomet implants and serum gonadotropins. Death was established with 47 transplanted embryos (61.8 per cent). With 19 embryos (25 per cent) death set in on the 21st day, and with 28 ones (26.8 per cent)--within the period of the 60th days of pregnancy up to calving. In 17.10 per cent of the transplanted embryos migration was seen toward the opposite horn, on the side of which the ovary contained no yellow body.

Animals↗
PubMed1986

[Superovulation induction in donor cows using the embryo transfer method].

A total of 108 cows were gynecologically investigated. Twenty-four of them were found to be suitable as donors. These were within the range of the 40th to the 60th day following calving, were not inseminated, and had no complications at calving and over the puerperal period. Estrus was synchronized via implants (3 mg norgestomet Synchromate B, Intervet in s/c application); 8 days later the donors were injected with 3000 IU PMSG each in order to induce superovulation. On the 10th day the implants were removed, and each animal was injected with 22 mg prostaglandin F3 alpha. At the 24th hour following the onset of estrus half of the donors were injected with anti-PMSG (i/v). It was found that the capacity of cows to respond with superovulation after hormonal treatment was quite individual. The application of antigonadotropic sera on the first day of estrus limited superovulation and raised the number of fertilized ova, resp., of embryos able to be transplanted. It was demonstrated also that to shorten the period from washing the uterus up to the impregnation of the donor animals it is necessary to apply hormonal therapy and preventive measures in dependence on the functional and morphologic state of the ovaries and the sexual apparatus.

Animals↗
PubMed1986

[Experiments to increase the conception rate in cows with disordered ovulation and spontaneous estrus].

Studied was the time period for the setting in of an ovulation that did not really take place, and the follicular cysts in cows following calving with regard to the effectiveness of the preparation Gn-RH vet. "Berlin-Chemie" in the treatment of the diseased animals. Attempts were made to raise the conception rate of cows manifesting delayed ovulation (with estral and postestral metrorrhagia). It was found that the preparation was effective in the treatment of cows with follicular cysts when applied at the rate of 1 mg in i/m injections. The therapeutic result was 75.4 percent. When introduced at 0.5 mg some 60 min prior to insemination (that is to be performed before the appearance, resp., the presence of estral and post-estral bleeding) the preparation was shown to induce ovulation. It also prevented hemorrhages, and raised the conception rate at first insemination.

Animals↗
PubMed1985

[Outlook for the programmed insemination of sheep in the anestrual season].

Studied were certain methods for programming the estrus and fixing the optimal term for the insemination of sheep. A record was kept of the changes taking place in the genital apparatus in various periods of time following the use of hormonal preparations during the anestral period. The fertility of sheep was also taken into consideration both after the first treatment with serum gonadotropin and after the two-fold programmed insemination at a 16-day interval with regard to the total fertility. It was shown that the optimal time for programmed insemination of sheep was between the 36th and the 56th hour after the three-fold injection with Prolosan at 12-hour intervals so far as periods other than the breeding season were concerned. Fertility at two-fold injection rated at 121 per cent, and conception--at 78.2 per cent.

Anestrus↗
PubMed1984

[Comparative studies of hormonal methods for affecting the reproductive functions of cows being raised by different technics].

Studied was the effect of two raising technologies in the industrial rearing of cows (tied and loose housing) along with the effect of the use of hormonal-and-stimulating therapy on their reproductive functions. It was found that the duration of the service period with the two technologies without using hormones was considerably long (respectively 124.3 +/- 7.8 up to 133.0 +/- 5.1 days, and 138.5 +/- 8.1 up to 144.0 +/- 3.3 days). The rate of conception at first insemination with tie-up housing varied from 20.23 to 56.67 per cent, and the total conception--from 74.41 to 86.67, whereas the fertilization of a cow required 2.35 to 2.77 doses of semen. At loose box housing the conception rate varied from 25.13 to 47.69 per cent and 75.15 to 84.61 per cent, and the used doses of semen were 2.40 to 2.69. Treatment with gravohormon between the 40th to 60th day following calving raised the total conception and the conception at first insemination--54.70 and 94.70 per cent at loose box housing, and 62.65 and 95.18 per cent at tie-up housing. Combined hormonal treatment with gravohormon and oroestron within the interval of the 100th-160th day following calving with the two technologies led to the very high clinical manifestation of the estrus, however, it did not raise the conception rate. Treatment with estrumate between the 100th and the 160th day after calving produced a higher effect with regard to conception as against the combined treatment with gravohormon and oroestron. The stimulating hormonal therapy had a higher effect on the conception at first insemination with the technology of tie-up housing.

Animal Husbandry↗
PubMed1979

[Ultrastructural-morphometric study of cardiac myocytes in the cell culture].

Ultrastructural-morphometric studies of the right and left heart ventricles of 4-day young rat were carried out during 7-day cultivation to examine morphologic and sterologic parameters of mitochondria and myofibrils. The morphometric data demonstrated a recurrent character of mitochondria and myofibril structural changes. The changes occurred should not be regarded as structural cell differentiations but rather as adaptation to the cultivation conditions.

Animals↗
PubMed1976

Chromosome rearrangements from spermatogonial chronic neutron irradiation in mice.

Adult male mice were given a range of neutron doses at 80 +/- 20 mrad/h from a plutonium-beryllium source. Cytogenetic analysis indicated that chronic spermatogonial exposure to a mean total dose of 10, 30, 52, 98 or 150 rad produced translocations, sampled in spermatocytes four months later, amounting to 0.32, 0.99. 1.69, 1.91 and 1.65%, respectively. The dose response for the 0-52 rad range was linear. For higher doses, a better fit to the data was an expression with dose exponent above unity.

Animals↗