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Biomedical subjects

M Dimitrov

Publications and source records attributed to M Dimitrov.

At least 37 records · Page 2Linked to original sources
PubMed1987

[Use of tribestan on rams with sexual disorders].

An experiment was carried out to define the stimulating effect of Tribestan on rams that were intended for breeding as well as on rams that exhibited sexual impotence and deteriorated semen qualities. The oral application of the preparation, following the pattern suggested by the authors, led to extending the period of sexual activity and to improvement of the semen production of the rams over the service period. The results of Tribestan therapy with rams having affected libido sexualis showed that the animals could recover up to the 7th-8th day with no essential morphologic changes in the structure of both testes and epididymides. The use of the preparation led to considerably influencing the endocrine activity of the testis, raising the testosterone level, and normalizing the sexual activity of rams affected with coital impotence.

Animals↗
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↗
PubMed1985

Initiation of transcription by bacteriophage T4-modified RNA polymerase independently of host sigma factor.

After infection of Escherichia coli with bacteriophage T4 a series of modifications of RNA polymerase takes place including the association of several small polypeptides. We isolated RNA polymerase from cells abortively infected with a series of T4 mutants which arrest phage development at different stages and found that different sets of associated proteins are present in RNA polymerase in each case. The patterns of associated polypeptides seem to correlate with DNA content in the infected cells, suggesting that some of them can be involved both in DNA replication and in the transcription apparatus. One of the modified forms of RNA polymerase contains stoichiometric amounts of a protein with Mr = 25,000 (25K protein), which remains associated with the core enzyme after the removal of sigma factor by chromatography on phosphocellulose. The 25K protein was purified to homogeneity and its effect on transcription selectivity was analyzed in an in vitro system using fragments of T4 DNA as templates. The 25K protein exists in two functional forms which direct core RNA polymerase to utilize two different types of transcription start sites (class I and class II promoters). Both activities do not require host sigma factor. The two forms of 25K protein seem to compete with each other for the core enzyme. The isolated 25K protein can form stable dimers, suggesting that its two activities are associated with the dimeric and monomeric forms. Class I (but not class II) promoters can also be utilized in response to the host sigma factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoradiography↗
PubMed1985

[Microclimate parameters in an isolation nursery for calves].

An experiment was carried out to establish the dynamic of some microclimate parameters on a transformed premise for the raising of calves up to 15 days of age. The newborns were accommodated in group boxes (2 to 5 animals) located in two rows, with a central path between them. The illumination coefficient was 1:14, and air exchange was effected through natural ventilation. The feeding of the newborn calves on the first and second day took place four times with colostrum and milk taken from their own dams and from the third day on it was performed three times a day. From the fourth day pooled milk was used, and from the seventh day the calves were offered concentrated fodder, hay, and water. The temperature and humidity regime of the air was investigated via thermohygrograph TZ18, and air velocity was checked periodically by means of Hill's catathermometer; the amount of carbon dioxide was measured after Wolpert, and that of ammonia gas--colorimetrically through indicator tubes. It was found that in the nursery under investigation no optimal temperature and humidity regime of the air was provided in the winter and transitive seasons. In winter there were highest percent of gastrointestinal and respiratory diseases. The air cooling coefficient was higher than the optimal one in the winter season, and it was lower in summer. Air velocity and gas admixture values proved within the admissible hygiene range.

Air Movements↗
PubMed1984

[Use of amopen foaming tablets in treating chronic endometriosis in cows].

Pharmaceutic studies were carried out with a total of 89 cows affected with chronic endometritis, following up the biopharmacokinetic and therapeutic effect of amopen foaming tablets that contained amoxicillin trihydrate at the rate of 30,000 and 45,000 IU. Andreev's catheter was used to introduce the tablets into the uterus. It was found that the use of 600,000 IU amoxicillin developed therapeutic concentrations within the uterus up to the 48 h-72nd hour. Amoxicillin persisted in the blood serum up to the sixth hour. It was not eliminated by milk. The therapeutic effect with such cows (in which the causative organisms were susceptible to amoxicillin) to which the amopen tablets were introduced into the uterus (14 t. x 630,000 IU) three to four times at 48-hour intervals was shown to be 76 per cent. The use of 5 tablets of 45,000 IU at the 24th hour after the last insemination of cows that failed to conceive, exhibiting no symptoms of inflammation, raised the conception rate by 24.1 per cent.

Administration, Topical↗
PubMed1982

[Attempt to stimulate labor in cows and heifers].

Attempts were made to induce delivery in 79 cows and 20 heifers, using the preparations dexametasone, cloprostenol, and dinolytic. The level of progesterone and estradiol was determined in four cows. A group of 20 heifers were injected with the preparation fortecortin at the rate of 30 mg. Four cows with induced parturition were used to evaluate the changes setting in with the blood level of estradiol 17 beta and progesterone. The following conclusions were made: 1. Best effects with regard to the indices duration of calving parturition and post-partal complications, and independence and service period are produced with the combined application of 50 mg sodium selenite and 680 UI vitamin E with 30 mg dexametasone. 2. The decrease in liveweight of the newborn calves from heifers at an average of 6 kg leads to the prevention of dystocia and the shortening of the post-partal period.

Adrenal Cortex Hormones↗
PubMed1980

[Morphological study of animal erythocytes using the scanning electron microscope].

The questions are discussed of erythrocyte morphology of various animal species and the changes occuring therein as a result of their ageing and pathologic and stress states. The investigation was effected with electron scanning microscope ISM-35 (IEOL--Japan). Shown are the morphologic pictures at direct fixation of erythrocytes--basic forms, sizes and percentage ratios for 8 animal species. The process of erythrocyte morophologic modifications during storage as whole blood in Olsever conservant for 168 h was studied and graphically presented. Recorded were also the changes in immunized animals and in stress state.

Animals↗
PubMed1979

[Effect of various methods of the preservation and preparation for study of human peripheral blood on erythrocyte morphology (scanning electron microscopy)].

In the paper the authors describe the influence of various ways of preservation and preparation of peripheral human blood on the morphology of erythrocytes. The investigation was performed by a scanning electrone microscope JSM-35 JEOL--Japan). The basic types of erythrocytes were shown, which were encountered in the samples. It was established that dehydratation and various methods for fixation of erythrocytes did not affect their morphology. The authors found changes, which occurred in erythrocyte morphology after blood preservation in anticoagulant,FBFR and as a whole blood at various intervals. The action of centrifugal forces in the process of centrifugation of blood on various types of erythocytes was indicated as well. The results of the studies were illustrated with 21 pictures, made at magnification of 3000 X up to 15 000 X.

Blood Preservation↗
PubMed1979

[Effect of certain procedures on the puerperal period in cows].

The course and duration of the post delivery period, uterine involution, independence and service period, number of fertilizations and the percentage of complications were studied in 82 cows aged 3 to 7 years, reared by two differing technoligies. One group (experimental) of 53 cows was reared together with the calves until the 6th day post delivery, while the other group (control) of 29 cows was reared without the calves. Both groups were subdivided into groups with and without complications; It was established that the proposed technology of cow rearing with the calves sucking until the 6th day post delivery creates good conditions for the course of puerperium. Clinically uterine involution lasts 27.5 +/- 0.88 days, the independence period lasts 95.8 +/- 5.94 days, the service period -- 115.9 +/- 4.28 days, and the fertilization index is 1.26 +/- 0.21. The proposed technology of cow rearing letting the calves suck until the 6th day post delivery can be applied in animal rearing practice.

Animals↗