A Comparative Study of Isolated Secondary Metabolites from Lichens and Their Antioxidative Properties.

Free radicals play a critical role in the chemical processes that occur in all cells. Pharmaceutical companies manufacture a variety of synthetically prepared antioxidants, but it is known that many of these can be carcinogenic. As a result, efforts are being made to find natural antioxidants that do not have these side effects.

A convenient synthesis of branched-chain nucleoside isothiocyanates aza-Claisen rearrangement.

Stereocontrolled introduction of a nitrogen atom at either C-2' or C-3' positions of nucleosides derived from uridine, 4--benzoylcytidine and adenosine was investigated. An efficient and rapid procedure was employed for creating new chiral centers at C-2' and C-3' positions using [3,3]-sigmatropic aza-Claisen rearrangement of allyl thiocyanates under conventional and microwave conditions. Structure of isothiocyanate products was confirmed by 1-D and 2-D NMR spectral analyses including selective H 1-D-NOE experiments.

Biological activity of selected lichens and lichen-based Ag nanoparticles prepared by a green solid-state mechanochemical approach.

Lichens dispose a wide spectrum of bioactive compounds known as secondary metabolites. Their biological effects like antioxidant and antibacterial activities are widely studied. Green synthesis of silver nanoparticles (AgNPs) is a method where the compounds/substances present in plants are used for reduction of AgNOinstead of toxic chemicals.

Fatty acid profile of ewe's milk infected with spp.

Background: Mastitis in sheep caused by spp. is a serious concern for dairy farming.

Aims: The objective of this study was to evaluate the impact of the intramammary infection (IMI) caused by spp.

Comparison of biofilm formation by Staphylococcus aureus and Staphylococcus epidermidis strains isolated from sheep milk using three diagnostic methods.

In this study we investigated 24 strains of Staphylococcus aureus and 33 strains of Staphylococcus epidermidis isolated from milk of sheep with clinical mastitis, for their ability to form biofilms. Three methods for the determination of a biofilm were used. When evaluating the growth on Congo Red agar (CRA), 79.

Effects of udder infections with Staphylococcus xylosus and Staphylococcus warneri on the composition and physicochemical changes in cows milk.

The aim of this study was an evaluation of the effects of two species of coagulase negative staphylococci (CNS), Staphylococcus xylosus and Staphylococcus warneri, on the changes in technological parameters of cows' milk. The study was conducted in a herd of Slovak Pied cattle breed (with share of HF blood). Based on the performance results from three subsequent months, cows in the 2nd and 3rd lactation with SCC up to 200 thousand/ml (8 heads, 32 quarters), and above 800 thousand/ml (8 heads, 32 quarters), after the 4th month of lactation, were selected.

An effect of mammary gland infection caused by Streptococcus uberis on composition and physicochemical changes of cows' milk.

An effect of mammary gland infection caused by Streptococcus uberis on the changes in cows' milk composition and its physicochemical properties was examined. The study was conducted in the herd of Slovak Pied breed cattle (with a share of HF blood), in 2nd and 3rd lactation, after 4th month of milking. Milk samples were collected from a quarter milking.

Effect of parenteral administration of selenium and vitamin E on health status of mammary gland and on selected antioxidant indexes in blood of dairy cows.

This study focuses on the effect of parenteral administration of Selenium (Se) and vitamin E on concentration of Se in plasma and the activity of glutathione peroxidase (GPx) in the blood of dairy cows during peripartal period and their effect on the reduction of clinical mastitis. From a 220 individuals Holstein herd in a two-four lactation-gestation cycle the control group (C), 1st (D1) and 2nd (D2) experimental group were selected. Every group consisted of 15 cows in the last phase of the pregnancy.

Limited genetic diversity of Aerococcus viridans strains isolated from clinical and subclinical cases of bovine mastitis in Slovakia.

The Aerococcus viridans isolates from bovine mastitis in Slovakia were isolated and characterized by classical microbiological and biochemical, and molecular techniques including IGS-PCR and rep-PCR, ARDRA and 16S rDNA gene sequencing. The substantial variability of antibiotic resistance patterns was observed. The majority of strains were resistant to beta-lactam antibiotics, the resistance to tetracycline was observed in 3 tested strains, resistance to lincomycin was found in 4 strains and practically all tested strains were sensitive to neomycin and ciprofloxacin.

[Dynamics of changes in the cytological picture of vaginal smears and circulating ovarian hormones during the puerperal period in ewes].

A postparturient period is characterized by low basal secretion of adenohypophysis gonadotropins with the following appropriate changes in ovarian hormones and their response to the morphology of vaginal epithelium. In this study the dynamics of the cytological picture of vaginal swabs and ovarian hormones 17 beta-oestradiol (E2) and progesterone was investigated in the puerpery of ewes. The objective was to obtain and extend the knowledge of cytological changes in vaginal epithelium and levels of ovarian hormones of ewes after parturition and of their relationships from the first several days after lambing until the 51st day of the period of observation.

[Dynamics of changes in the serum levels of cholesterol, thyroid and ovarian hormones in the postpartum period in ewes].

Postparturient anoestry, spontaneously changing over to seasonal anoestry, represents an important reserve of full utilization of the reproductive potential of sheep. In spite of the fact that the length of gestation in sheep only amounts to 148 days (+/- 5 days), inability of most sheep to enter the cycle during the spring season acts as a factor limiting the number of lambings--and at the same time production of lambs--to one lambing per year. In order to obtain more detailed knowledge of hormonal conditions in sheep puerpery, the presented work was directed at the study of dynamic changes in concentrations of thyroxine (T4), triiodothyronine (T3), 17 beta-estradiol (E2), progesterone (P4) and cholesterol (Chol) in the blood serum of ewes and at their mutual correlative dependences between the 36th hour and the 51st postparturient day.

[Biometric parameters of the uterus and ovaries in sheep after administration of Depotocin inj. Spofa in early puerperium].

Objectivisation of the physiological course of puerpery and control of involution processes of uterus represent topical questions of an increased frequency of lambing. Our study was directed at the determination of the weight, length of body and horns of uterus as well as of the weight, length, width and height of ovaries, following the administration of carbetocin (Depotocin inj. Spofa), in the puerperal period of Slovak Merino sheep.

[Biometric parameters of the uterus, ovaries and levels of 17 beta-estradiol (E2) after delivery in sheep].

Biometric changes of uterus, ovaries, follicles and 17 beta-oestradiol (E2) concentrations were investigated in 15 lambing ewes of the Slovak Merino breed in the puerperal period. The sex organs were excised immediately after bleeding from ewes slaughtered on days 1, 7, 17, 25 and 34 post partum (p. p.

[The effect of steroidal dominance on cAMP, cGMP, progesterone and 17 beta-estradiol levels in the fluid of the largest follicle].

Concentrations and mutual correlations of the cyclic adenosin monophosphate (cAMP), quanosin monophosphate (cGMP), progesterone (P4) and 17-beta-estradiol (E2) were studied in the fluid of the largest follicles in cows, in dependence on the steroid dominance: estrogen-dominant (ED), progesterone-dominant (PD) follicles. Mean cAMP and cGMP concentrations in the follicular fluid in the estrogen-dominant follicles were significantly higher than in the progesterone-dominant follicles; in both cases at P less than 0.01.

[Changes in blood levels of progesterone, triiodothyronine and thyroxine and the results of quantitative histological analysis of the placentoma and corpus luteum in cows after prolonged labor].

Changes in the cell structure of the placentoma and the corpus luteum were subjected to quantitative histological investigation, parallel with the examination of the concentrations of progesterone (P4), triiodotyronine (T3) and tyroxin (T4) during parturition (Oth hour) and two and six hours after parturition. The hormone concentrations were determined by the RIA method. The results of the quantitative histological analysis of the placentomae and the corpus luteum suggest that when the placenta is retained there is a significantly higher number of maintained epithelial cells in the placentoma crypts and a higher number of unchanged small, dark and large, light lutein serraetion cells in the biopsy of the corpus luteum during the period under investigation.

[Pregnancy in dairy cows in various times of the year in relation to thyroxine and triiodothyronine levels].

Conception of dairy cows was investigated in relation to changes in thyroxine (T4) and triiodothyronine (T3) concentrations in March (n = 15), June (n = 10) November (n = 7) after oestrus synchronization by cloprostenol (Oestrophan Spofa) at a dose of 0.05 mg per head. The cows were inseminated from 8.

[Radioimmunologic determination of progesterone and rectal ovarian palpation in embryonic death in cows].

Repeated radio-immunological assays of progesterone in milk and ovary rectal palpation were used for indirect determination of embryonal mortality in cows. Milk sampling and rectal examination were made in the insemination period and then in two- to three-day intervals, mostly from the 21st day after insemination till the early pregnancy determination made after the 42nd day on the basis of the double wall phenomenon. Observation was made in 185 animals from two herds.

[Changes in surface follicles and ovarian weight in testing for responsiveness in dairy cows after induction of superovulation using PMSG and cloprostenol].

We evaluated the ovaries of 34 cows cross-bred of the Slovak Pied and Lowland Black-pied breeds which were culled and intended for slaughter during the winter type of feed rations. For superovulation treatment we used PMSG in the preparation Serum Gonadotropin (Bioveta, Nat. Ent.

[The effect of beta-carotene on thyroxine and cholesterol levels in pregnant heifers before and after parturition].

Thyroxine (T4) and cholesterol concentrations and their dynamic changes and differences were studied in 20 pregnant heifers 10 days before calving until 56 days after calving. Ten control heifers were fed the feed ration for pregnant heifers according to Czechoslovak Standard CSN 46 7070. The feed ration given to another ten (experimental) heifers was fortified with 300 mg of synthetic beta-carotene per head/day within the period of five months before insemination, during pregnancy and till the 56th day after parturition.

[Levels of thyroxine, beta carotene and vitamin A during successful and unsuccessful insemination of heifers].

We studied the concentrations of thyroxine (T4), beta-carotene and vitamin A (vit. A) on the day (zero-th day) of the first successful and unsuccessful insemination of 63 heifers that were administered feed rations balanced according to the Czechoslovak standard CSN 46,7070, housed all the year round, inseminated at uniform time (8:00-9:00 a. m.

[Concentrations of thyroxine, beta carotene, vitamin A and pregnancy in heifers after administration of beta carotene].

Serum concentrations of thyroxine (T4), beta-carotene (beta K), vitamin A and conception after the first insemination on the zero, sixth and 21st day were studied in 63 heifers fed synthetic beta K supplement in groups I to IV at stanchion housing and low-carotene diet. The following amount of beta K was supplemented per head/day: I--0 mg (control, n = 17), II--100 mg (n = 16), III--200 mg (n = 14) and IV--400 mg (n = 16). The parameters were evaluated separately according to groups and conception.

[Correlation between the thyroxine, 17-beta-estradiol and luteinizing hormones in the systemic circulation and the rectal and vaginal temperature in heifers and cows after administration of cloprostenol].

Changes in the concentration of 17beta-oestradiol (E2) and luteinizing hormone (LH) and in the rectal and vaginal temperatures (RT and VT) were studied along with the changes in thyroxine concentration (T4) in three cows and three heifers in the luteal stage of the cycle; the animals had been intramuscularly treated with 2 ml Oestrophan (cloprostenol). The closeness of the correlation between T4 and the remaining parameters under study was determined by the calculation of the correlation coefficient and statistical significance. The concentrations of T4 before and during cloprostenol administration were high in comparison with the post-treatment levels.

[Micromorphology of the endometrium of dairy cows after estrus synchronization with cloprostenol].

Trials were conducted to study and describe the micromorphological parameters of endometrium in five cows of the Black-Pied breed after the expiration of the synchronizing effect of cloprostenol in the Oestrophan inj. Spofa preparation. Two animals four to five days after oestrus were used as control and three cows on the sixth day of sexual cycle with rectally palpated corpora lutea were treated intramuscularly with 0.