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Biomedical subjects

G Jagiello

Publications and source records attributed to G Jagiello.

At least 19 recordsLinked to original sources
PubMed1998

Preliminary pharmacokinetic studies of Ukrain in rats.

Ukrain (thiophosphoric acid derivative of Chelidonium majus L. alkaloids) was administered to rats i.p. at a dose of 28 mg/kg (equivalent to 0.1 LD50). A high performance liquid chromatography (HPLC) method for rapid determination of Ukrain in plasma has been described. It was found that Ukrain rapidly penetrated into the plasma of the rats and the elimination of the drug from the plasma was slower. The results obtained were as follows: absorption rate constant ka = 0.0432 [min-1]; elimination rate constant K = 0.0113 [min-1]; drug half-life t1/2 = 61.32 min; actual concentration of Ukrain in the plasma C = 33 e-0.0113t - 39 e-0.0432t [microgram/ml]; and delay in drug absorption T0 = 5.23 min.

Alkaloids↗
PubMed1995

Rearranged mitochondrial genomes are present in human oocytes.

Using quantitative PCR, we have determined that a human oocyte contains approximately 100,000 mitochondrial genomes (mtDNAs). We have also found that some oocytes harbor measurable levels (up to 0.1%) of the so-called common deletion, an mtDNA molecule containing a 4,977-bp rearrangement that is present in high amounts in many patients with "sporadic" Kearns-Sayre syndrome (KSS) and progressive external ophthalmoplegia (PEO). This is the first demonstration that rearranged mtDNAs are present in human oocytes, and it provides experimental support for the supposition that pathogenic deletions associated with the ontogeny of sporadic KSS and PEO can be transmitted in the female germ line, from mother to child. The relevance of these finding to the accumulation of extremely low levels of deleted mtDNAs in both somatic and germ-line tissues during normal human aging is also discussed.

Chromosome Mapping↗
PubMed1989

Colcemid effects on homologue pairing and crossing over during fetal mouse oogenesis.

Colcemid was administered to gestational day 13 female mice to test effects on homologue pairing, synapsis and recombination of fetal oogenesis. Pairing abnormalities were detected in pachytene oocytes by light and electron microscopy examination of bivalents and synaptonemal complexes. Reduction of total chiasmata per treated diplotene oocyte (22.74) compared to controls (31.07) was found.

Animals↗
PubMed1986

DNA synthesis studies in pre-meiotic mouse oogenesis.

DNA fiber autoradiography was used in mouse oogenesis to test Callan's hypothesis that a longer S phase results from a reduction in the number of active initiation sites. The data indicated that the premeiotic increase in the duration of S phase in mouse oogenesis was characterized by a rapid initial rate of chain growth and a larger replicon size when compared with replicating DNA of somatic mouse cells. These findings were at variance with those in mouse spermatogenesis and also did not support the Callan hypothesis of activation site repression.

Animals↗
PubMed1985

Unique effects of spindle inhibitors on mammalian oocyte meiosis.

The effects of Nocodazole, reported to be a rapidly reversible inhibitor of microtubules in somatic cells (1), and Colcemid, a classic microtubule inhibitor, were studied for their effects on mouse and cow oocyte in vitro meiotic resumption. When present throughout the maturation period to Metaphase II/Polar Body I, both compounds predictably inhibited progression at Metaphase I (MI). An unexpected effect was seen on mouse germinal vesicle breakdown (GVB) with both inhibitors, but not in cow oocytes tested with Nocodazole. Recovery from Nocodazole was notably retarded in mouse oocytes even with brief exposure times. Addition of 1 microgram/ml of Nocodazole 10 min after commencement of mouse and cow oocyte incubation was sufficient time to allow normal GVB, while inhibition at MI still took place suggesting that the critical events of GVB occur very quickly in vitro.

Animals↗
PubMed1983

Fiber DNA studies of premeiotic mouse spermatogenesis.

The technique of fiber DNA measurement was used to study the possibility that the lengthening of the DNA "S" phase previously reported for mouse premeiotic spermatogonia was due to a reduced number of initiation sites. The mean replicon size of neonatal mouse preleptotene cells was similar to sizes reported for adult mouse somatic cells. A slow rate of DNA chain growth was observed in all cells from day 1 through days 10-12 of age. It was felt that the meiotic entry in male mouse germ cells may involve a slower replication fork rate and other factors which increased the time between activation and replication of replicon families.

Animals↗
PubMed1983

Complete chromomere map of mid/late pachytene human oocytes.

A complete chromomere map of the mid/late human pachytene oocyte has been developed from ovaries of 35 fetuses at 18-22 weeks gestation. Bivalents, which were all specifically identifiable, were more extended than comparable human spermatocyte bivalents. The total number of chromomeres found was 639, exceeding both the number of human pachytene spermatocytes and the number of mitotic bands seen in metaphase somatic chromosomes. Each oocyte bivalent contained more chromomeres than the number of corresponding prometaphase chromosome bands. Similarities and differences were noted in regional comparisons of chromomere distribution between oocytes and spermatocytes.

Chromosome Banding↗
PubMed1982

Alterations of mammalian oocyte meiosis I with divalent cations and calmodulin.

Experiments using a Ca2+/Mg2+, serum free media were carried out aimed at clarifying proposed effects of these divalent cations on in vitro meiotic maturation of mouse and cow oocytes. Agents known to perturb intracellular Ca2+ or calmodulin were also studied. Total absence of both cations restricts both oocyte species from completing meiosis I. Media containing Mg2+ and no Ca2+ permitted some maturation in both species. Absence or small amounts of Mg2+ in the media containing control amounts of Ca2+ was much more inhibitory for the cow than the mouse oocyte. Studies of mouse oocyte maturation with Verapamil, Epinephrine and A23187 demonstrated an inhibition of maturation perhaps by the intracellular Ca2+ changes these agents are alleged to induce. A dependency of mouse oocyte maturation on active Ca-Calmodulin complexes was suggested by the calmodulin inhibitor studies.

Animals↗
PubMed1981

A note on the inhibition of in vitro meiotic maturation of mammalian oocytes by dibutyryl cyclic AMP.

Cytogenetic data are presented which indicate species differences in the response of oocytes maturing in vitro in the presence of dibutyryl cyclic AMP (dbcAMP). Inhibition of ewe oocyte maturation was noted at germinal vesicle, MI, and MII in the presence of 25-750 microgram/ml of dbcAMP. Cow oocytes were primarily affected at MI and MII by similar concentrations, and only 750 microgram/ml delayed golden hamster oocytes at these stages. These findings highlight the variability between the responses of the oocytes of these mammals and the rat, mouse, or pig.

Animals↗
PubMed1981

A pachytene map of the mouse spermatocyte.

Pachytene chromomere maps of early and mid/late mouse spermatocytes have been prepared which permit exact identification of each bivalent. The average total number of chromomeres on the autosomal bivalents was 248 in the early cells and 184 in the mid/late. There was close correspondence between early and mid/late chromomeres in 122 locations. Comparisons of early pachytene chromomeres with published prometaphase dark G bands revealed 1.6 more chromomeres in the meiotic autosomal bivalents, with close correspondence of larger chromomeres and major mitotic bands. Fewer chromomeres were found in pachytene spermatocytes than had been seen in a previous study of pachytene oocytes. Comparisons of chromomeres of spermatocytes and oocytes revealed several differences.

Animals↗
PubMed1980

A pachytene map of the mouse oocyte.

A map of the mouse oocyte has been constructed utilizing early and mid/late pachytene stages. Each bivalent was clearly identified. At the mid/late stage 195 chromomeres corresponded directly to precursor chromomeres in the early stage, whilst 84 chromomers were derived from two chromomers from the early stage. The X and 13 bivalents were found to have a single chromomere in the early stage which later yielded two sites. There were approximately twice as many total chromomeres as mitotic bands, with good correspondence between pachytene chromomeres and major mitotic bands. Application of the use of mapping to a previously reported bivalent bearing a pleiomorphic region is noted.

Animals↗
PubMed1979

Analyses of diplotene chiasma frequencies in mouse oocytes and spermatocytes in relation to ageing and sexual dimorphism.

Diplotene chiasma frequencies from "early" (day 16) fetal oocytes are significantly greater than the average from "late" (day 18) oocytes. A decrease in chiasma frequencies from both ages was found at diakinesis/MI in oocytes of young or old adults females, indicating a loss of chiasmata and/or terminalization. A greater number of type I univalents was found in "late" oocytes than "early" oocytes entering diplotene. No difference were found in chiasma frequencies of male diplotene spermatocytes studied at 23 days, 2 months, or 24 months of age. A greater chiasma frequency was generally found in the female than the male at all ages studied.

Age Factors↗