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Biomedical subjects

P Turini

Publications and source records attributed to P Turini.

At least 19 recordsLinked to original sources
PubMed2003

Bovine embryo technologies.

Embryo technologies are a combination of assisted reproduction, cellular and molecular biology and genomic techniques. Their classical use in animal breeding has been to increase the number of superior genotypes but with advancement in biotechnology and genomics they have become a tool for transgenesis and genotyping. Multiple ovulation and embryo transfer (MOET) has been well established for many years and still accounts for the majority of the embryos produced worldwide. However, no progress has been made in the last 20 years to increase the number of transferable embryos and to reduce the side effects on the reproductive performance of the donors. In vitro embryo production (IVP) is a newer and more flexible approach, although it is technically more demanding and requires specific laboratory expertise and equipment that are most important for the quality of the embryos produced. Somatic cell cloning is a rapidly developing area and a very valuable technique to copy superior genotypes and to produce or copy transgenic animals. More knowledge in oocyte and embryo biology is expected to shed new light on the early developmental events, including epigenetic changes and their long lasting effect on the newborn.Embryo technologies are here to stay and their use will increase as advances in the understanding of the mechanisms governing basic biological processes are made.

Animals↗
PubMed2001

Embryo production by ovum pick up from live donors.

Embryo production by in vitro techniques has increased steadily over the years. For cattle where this technology is more advanced and is applied more, the number of in vitro produced embryos transferred to final recipients was over 30,000 in 1998. An increasing proportion of in vitro produced embryos are coming from oocytes collected from live donors by ultrasound-guided follicular aspiration (ovum pick up, OPU). This procedure allows the repeated production of embryos from live donors of particular value and is a serious alternative to superovulation. Ovum pick up is a very flexible technique. It can be performed twice a week for many weeks without side effects on the donor's reproductive career. The donor can be in almost any physiological status and still be suitable for oocyte recovery. A scanner with a sectorial or convex probe and a vacuum pump are required. Collection is performed with minimal stress to the donor. An average of 8 to 10 oocytes are collected per OPU with an average production of 2 transferable embryos. The laboratory production of embryos from such oocytes does not differ from that of oocytes harvested at slaughter as the results after transfer to final recipients. For other species such as buffalo and horses OPU has been attempted similarly to cattle and data will be presented and reviewed. For small ruminants, laparotomy or laparoscopy seems the only reliable route so far to collect oocytes from live donors.

Animals↗
PubMed2001

Bovine oocytes treated prior to in vitro maturation with a combination of butyrolactone I and roscovitine at low doses maintain a normal developmental capacity.

Butyrolactone I (BL-I) and Roscovitine (ROS), two specific and potent inhibitors of M-phase promoting factor (MPF) kinase activity, were used to block germinal vesicle breakdown (GVBD) of cattle oocytes. A concentration 6.25 microM BL-I and 12.5 microM ROS blocked over 93.3 +/- 2.5% of oocytes in germinal vesicle (GV) stage during a 24-hr culture period. Following a second 24-hr culture step in maturation medium (IVM) almost all (91.5 +/- 3.0%) inhibited oocytes resumed meiosis and reached the metaphase II (MII) stage. The MII kinetics was different for inhibited and control oocytes. Fifty percent MII was reached at 13-14 hr in BL-I + ROS treated oocytes, compared to 18 hr in control oocytes. Therefore, control oocytes were fertilised (IVF) after 22 hr IVM and inhibited oocytes after 16 or 22 hr IVM. After IVF, percentage of grade 1 freezable embryos on day 7 (D + 7) as well as percentage of blastocyst formation on D + 8 in the group of BL-I + ROS treated oocytes fertilised after 16 hr IVM were higher (P < 0.05) compared with the other experimental group fertilised after 22 hr IVM but not different in comparison with the control. Survival to freezing and thawing of grade 1 embryos frozen on D + 7 was employed as viability criteria and was similar in all groups. Thus, the presence of BL-I + ROS in the prematuration medium of bovine oocytes determines a reversible meiotic block, without compromising their subsequent developmental competence.

4-Butyrolactone↗
PubMed1998

Inhibitory effect of 1,3,5-triphenyl-4,5-dihydro-(1H)-pyrazole derivatives on activity of amine oxidases.

A new series of 1,3,5-triphenyl-4,5-dihydro-(1H)-pyrazole derivatives was synthesized to ascertain the contribution of substituted phenyl rings present on the 4,5-dihydro-(1H)-pyrazole nucleus to the monoamine oxidases inhibition and bovine serum amine oxidase inhibition. All compounds were tested on bovine brain mitochondria preparation containing flavin-monoamine oxidases and on purified bovine serum amine oxidases, taken as a model of trihydroxyphenylalanine quinone-copper-containing amine oxidases. The 1,3,5-triphenyl-4,5-dihydro-(1H)-pyrazole derivatives showed a good inhibitory activity and belonged to the third generation of monoamine oxidase inhibitors and bovine serum amine oxidase inhibitors which have the advantage of acting through a reversible mode. Furthermore, their activity showed a good degree of selectivity towards the bovine serum amine oxidase inhibition dependent on the substituents present on the phenyl ring at position 5 of the 4,5-dihydro-(1H)-pyrazole.

Animals↗
PubMed1995

Inhibition of diamine oxidase activity by metronidazole.

Metronidazole was found to be a non-competitive inhibitor of man, rabbit and rat intestinal diamine oxidases with an inhibition constant value of approximately 10(-4) M. The purified bovine serum amine oxidase was not inhibited, whereas the purified swine kidney enzyme gave similar results. These findings suggest that metronidazole and similar compounds, used as antibacterial and antiprotozoal drugs, should be given under careful control, especially when administered for long times, because a decrease of intestinal diamine oxidase activity was proven to be a risk factor for several pathologies of this organ.

Amine Oxidase (Copper-Containing)↗
PubMed1987

[Substances inhibiting amine oxidases. III. Synthesis and amine oxidase inhibition of imidazoquinoline derivatives].

The activity of copper and FAD dependent amine oxidases was tested with some derivatives of 3H-imidazo[4,5-h]quinoline and its isomers 3H-imidazo[4,5-f]quinoline, the chemistry of which is described in the literature (1), and Ki calculated. The methyl derivative of 3H-imidazo[4,5-f]quinoline was found to activate the copper bovine serum enzyme, but inhibits the FAD mitochondrial enzyme.

Animals↗
PubMed1980

[Monoamine oxidase inhibitors. I. Synthesis of N-cyclopropyltryptamines].

The synthesis of two new N-cyclopropyltryptamines is described. By treating 5,6-dimethoxyindole with oxalyl chloride and N-benzylcyclopropylamine, N-benzyl-N-cyclopropyl-5,6-dimethoxyindole-3-glyoxalamide is obtained. The reduction of this compound by LiAlH4, gives N-benzyl-N-cyclopropyl-5,6-dimethoxytryptamine, which is hydrogenated to N-cyclopropyl-5,6-dimethoxytryptamine. Similarly N-cyclopropyl-6,7-dimethoxytryptamine is prepared. Preliminary results indicate a different specificity of the inhibitors used on mitochondrial and bovine plasma enzyme (monoamine oxidase) attributable to the position of the methoxy groups.

5-Methoxytryptamine↗