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Biomedical subjects

L Vincenti

Publications and source records attributed to L Vincenti.

12 recordsLinked to original sources
PubMed2006

Isolation, culture, and characterization of embryonic cell lines from vitrified sheep blastocysts.

This study was conducted to isolate, to culture, and to characterize embryonic cell lines from in vitro produced vitrified sheep blastocysts. Embryos were produced and vitrified at the expanded blastocyst stage. Ten inner cell masses arising from day 6-7 blastocysts were isolated by immunosurgery, disaggregated, and cultured onto mitomocin-C-inactivated mouse STO fibroblasts (MIF). After 5 or 6 days of culture the primary cell colonies were disaggregated, seeded in a new MIF, and cultured for 3 or 4 days to form new colonies called Passage 1. These cells were then disaggregated and cultured for other two passages. The primary cell colonies and Passage 2 colonies expressed stage specific embryonic markers SSEA-1, SSEA-3, and SSEA-4, and were alkaline phosphatase positive. In the absence of feeder layer and human leukemia inhibitory factor (LIF), these cells differentiated into variety of cell types and formed embryoid bodies. When cultured for an extended period of time, embryoid bodies differentiated into derivatives of three embryonic germ (EG) layers. These were characterized by detection of specific markers for differentiation such early mesoderm (FE-C6), embryonic myosin (F1-652), neural precursor (FORSE-1), and endoderm (anti-cytokeratin 18). To our knowledge, this is the first time that embryonic cell lines from in vitro produced and vitrified ovine blastocysts have been isolated and examined for detection of SSEA markers, and embryoid bodies have been cultured and examined for specific cell surface markers for differentiation.

Animals↗
PubMed2005

The effect of Mycoplasma mycoides ssp. mycoides LC of bovine origin on in vitro fertilizing ability of bull spermatozoa and embryo development.

Several Mycoplasma species may adversely affect bovine spermatozoa viability and embryo development. Mycoplasma mycoides ssp. mycoides large-colony (LC) has been isolated from naturally aborted bovine fetuses and from bull semen. The objective of this study was to evaluate whether M. mycoides ssp. mycoides LC contaminated bovine ejaculates could (i) impair in vitro fertilizing ability of bull spermatozoa, (ii) impair embryo development, and (iii) evaluate potential spread by reproductive technologies. In the present study, spermatozoa of 10 fertile bulls were contaminated with M. mycoides ssp. mycoides LC, at a final concentration of 1.5 million CFU/ml and incubated for 60 min before evaluating spermatozoa motility and acrosome reaction inducibility with calcium ionophore. In addition, in vitro contaminated semen of a bull previously shown to have a good in vitro fertilizing ability, was used in an IVF procedure. Embryo development stage on Day-7 of culture was evaluated. Spermatozoa and embryos at morula and blastocyst stages were routinely processed for transmission electron microscopy observation. Both mean total and progressive motility decreased (P < 0.01 ) upon spermatozoa incubation with Mycoplasma. One-hour incubation with calcium ionophore increased the percentage of acrosome-reacted spermatozoa, although Mycoplasma contamination reduced calcium ionophore treatment efficacy (P < 0.05). Ultrastructurally, Mycoplasma microorganisms appeared as moderately electron-dense sphere-shaped particles, adhering to cell membranes. Sperm mid-piece sections showed numeric aberrations of the central singlets such as nine + zero or nine + one of the axonemal complex. Further morphological abnormalities included partial or total absence of dinein arms and radial fibers, with lack of the bridge and the central ring in 35.00 +/- 4.20% of contaminated cells, whereas these abnormalities were not observed in uninfected ones. The IVF trials showed that two-four cell blocks were higher (P < 0.05) in the infected group. Ultrastructure of Day-7 contaminated embryos showed Mycoplasma particles adhering and infiltrating the outer layer of the zona pellucida. Our investigations suggest that M. mycoides ssp. mycoides LC contaminating the bovine ejaculate induced adverse effects on in vitro spermatozoa-fertilizing ability and embryonic development. Some satisfactory quality transferable embryos could be produced in contaminated IVF systems. This could imply a potential transmission of this microorganism through reproductive technologies.

Acrosome Reaction↗
PubMed2003

Evaluation of cabergoline and buserelin efficacy for oestrous induction in the bitch.

The purpose of this work was to compare two different protocols of oestrous induction, using either a dopamine agonist (cabergoline) or a GnRH agonist (buserelin) in anoestrus bitches. The clinical trial involved 22 Beagle bitches, randomly allotted to two treatment groups: group A (n = 12) was orally administered cabergoline (Galastop(R); Centralvet-Vetem, Milan, Italy; 5 microg/kg SID), until the onset of cytological oestrus or for a maximum of 30 days and group B (n = 10) was treated with buserelin acetate, (Suprefact(R); Aventis Pharma, Milan, Italy), administered subcutaneously t.i.d., at 1.5 microg/kg for 11 days and 0.75 microg/kg for the following 3 days. Blood samples were collected twice a week to measure progesterone and prolactin concentration. Both cabergoline and buserelin produced a significant early decline in prolactin concentration (p < 0.01), but the effect of cabergoline lasted longer. Progesterone concentration was significantly affected by buserelin administration, showing a significant increase (p < 0.01) from day 3 to day 6 of treatment. Cabergoline confirmed its effectiveness in inducing oestrus as 10 of 12 bitches responded to the treatment, were mated and whelped. On the contrary, oestrus was observed in only three of 10 buserelin-treated bitches and in two of them 7 and 13 days after the end of treatment. These same two bitches accepted mating and conceived. The results suggest that in a clinical setting, dopaminergic treatment is the treatment of choice as it yields more consistent results and involves a much easier administration protocol.

Administration, Oral↗
PubMed2000

Hypoosmotic swelling (HOS) as a screening.

Semen from 5 Piedmontese bulls was subjected to the hypoosmotic swelling (HOS) test in order to determine if the results could be correlated to the fertilizing capacity in vitro. Semen was routinely prepared for in vitro fertilization (IVF), with aliquots being sampled after thawing, after separation on a Percoll gradient and after capacitation in a medium containing heparin. The aliquots were added to a fructose-sodium citrate hypoosmotic solution (100 mOsm) and incubated at 37 degrees C for 5 min. At least 200 spermatozoa were observed at x 400 and classified according to the presence or the absence of a swollen tail. After capacitation, spermatozoa were used to fertilize in vitro-matured bovine oocytes (1.5 x10(6) cells/mL); IVF was performed in Fert-TALP medium supplemented with 6 mg/mL BSA and 10 microL/mL heparin in a humidified atmosphere with 5% CO2 and 5% oxygen. Presumptive zygotes were cultured in SOF medium supplemented with 8 mg/mL BSA and amino acids. There were no significant differences in the in vitro fertility of the bulls, but a significant difference was found between bulls in the response to the HOS test. The 3 assays were significantly correlated, while no significant correlation was observed between the percentage of swollen spermatozoa and in vitro fertility. The HOS test does not appear to be sufficiently sensitive to discriminate between semen samples of intermediate fertility like those used in this preliminary research.

Animals↗
PubMed1997

Differential effects of pharmacologically generated reactive oxygen species upon functional activity of epididymal mouse spermatozoa.

Several studies indicate that reactive oxygen species (ROS) are involved in defective sperm function pathophysiology. In this study we attempted to determine differentially the effects of xanthine (0.12 mM) plus xanthine oxidase (0.035 U/mL) (X+XO, a ROS promoter system), ROS scavengers (Tiron (TIR, 15 mM); catalase (CAT, 10 micrograms/mL); dimethylsulfoxide (DMSO, 140 mM)), and X+XO plus scavengers on several epididymal mouse spermatozoa functional parameters, incubated in NTPC medium, for 29 min. In the presence of X+XO, progressive gametes significantly diminished. TIR or CAT attenuated this effect, but DMSO did not. Inversely, X+XO increased the bending-forms population; only TIR reversed this phenomenon. The ROS promoter system diminished the viable cell population; all scavengers assayed maintained sperm viability at levels similar to control ones. When exposed to hypoosmotic shock after 29 min incubation with X+XO, the percentage of swollen cells decreased; TIR, CAT, or DMSO did not prevent this effect. Our experiments demonstrate that it is possible to differentiate the deleterious ROS effects upon sperm functional activity. O-2. and H2O2 preferentially seem to modify sperm motility, O-2. exhibiting the greatest ability for generating bending-form gametes, OH-being the most lethal ROS. In addition, sperm membrane clearly appears as the most damaged structure.

Animals↗
PubMed1996

Changes in corticosterone levels and sperm functional activity by chronic stress in rats.

Corticosterone levels and epididymal sperm functional activity have been studied in rats subjected to immobilization stress (A: 12 days) or variable chronic stress (B: 24 days; C: 32 days and D: 32 days plus 28 days without stress). Plasma corticosterone levels were significantly enhanced in B and C groups. Body and testicular weight significantly decreased in C and D groups. A decrease in viability or percentage of progressive epididymal spermatozoa was detected in C and D groups. Responses of spermatozoa to hypoosmotic shock remained unaltered in all groups. Results suggest that sustained increase in activity of the hypothalamo-adenohypophyseal-adrenal cortical system alters the activity of the hypothalamo-adenohypophyseal-testicular axis.

Animals↗
PubMed1992

[The correlation between the conventional spermogram parameters and the osmotic resistance tests in patients from among fertile and infertile couples].

It is well accepted that routine semen analysis is a useful tool for valuation of male potential fertility. In our environment, HOST has been recently applied as an additional approach which early detects structural and/or functional alterations of the sperm membranes. We investigated the possible relationship between some semen parameters and HOST in males from A) fertile couples (23-32 years old; n = 11) and B) sterile couples (25-35 years old; n = 171. Sperm concentration, motility, morphology and HOST (semen incubation in hypoosmotic saline solution-sodium citrate and fructose, 150 m0sm/1--, 37 degrees C during 60 min) were evaluated. In HOST determinations, results higher than 60% of swollen cells are considered within the normal range. In our study, sperm from males of B group showed a significantly lower percentage of hyperhydrated cells than those from A group (55.7 + 2.2% and 70.4 + 2.3% respectively; p < .001). In addition, a significant statistical correlation between HOST vs motility or normal morphology was found. On the contrary, we detected no correlation between HOST vs sperm concentration or volume. We suggest that development and application of HOST as a routine, can play an important role in the evaluation and prognosis of an infertile couple.

Adult↗
PubMed1987

Hyperactivated motility induced in mouse sperm by calcium ionophore A23187 is reversible.

The reversibility of hyperactivated motility was tested in caudal epididymal mouse sperm by treating them with 1 microM calcium ionophore A23187 in dimethyl sulfoxide (DMSO), followed 2 min later by the addition of medium containing high levels of bovine serum albumin (BSA) (final concentrations: 0.5 microM A23187, 22 mg/ml BSA). Controls received DMSO alone, followed by BSA. Immediately following treatment with A23187, motility was weak and vibratory. Two minutes after the addition of high levels of BSA, motility was hyperactivated, as determined by videotape analysis of linearity of trajectory and acuteness of flagellar bending. Ten minutes after the addition, the movement pattern returned to that of fresh, uncapacitated epididymal sperm. Control sperm retained the linear swimming pattern of fresh caudal epididymal sperm during the 10 min of observation. Ninety minutes later, however, both control and treated sperm became hyperactivated. The percentage of motile sperm was not affected by treatment or time. Thus, ionophore-induced hyperactivation is reversible and does not interfere with the normal development of hyperactivation during incubation under capacitating conditions in vitro.

Analysis of Variance↗
PubMedDate not supplied

[Optimal reconstruction after resection of the rectum in cancer surgery].

The efficacy of colon-J-pouch anal anastomosis (CPAA) in reducing defecatory frequency and urgency and the incidence of anastomotic fistulas has been proved by several studies but only as compared to straight colo-anal anastomosis (CAA) of the end-to-end type. We investigated the role played by the colon pouch in the strict sense, without the influence of a different CAA model, in a randomised prospective study comparing CPAA and straight side-to-end CAA. Over the period from 1994 to 1998 we selected 66 of 118 patients operated on for rectal cancer: a CPAA was constructed in 35 (group P) and a direct side-to-end CAA in 31 (group D). The two groups were well matched for surgeon, type of patient, stage of disease and incidence of radiotherapy and presented no differences in operative mortality, general and anastomotic morbidity, or need for reoperation. Functional results: after 3, 12 and 36 months, defecatory frequency > or = 4 movements/day was observed in 93.4, 67.7 and 41.6% of cases, respectively, in group D as against 25.7, 14.2 and 13%, respectively, in group P (P < 0.05), while defecatory urgency was recorded in 77.4, 35.4 and 27.9% of cases, respectively, in group D as against 34.2, 17.1 and 9%, respectively, in group P (p < 0.05). In the long term, incontinence was also significantly lower in group P. The colon pouch improves sphincter rehabilitation after anal recanalization compared to straight side-to-end CAA. It does not affect anastomotic morbidity but affords a protective effect on function in irradiated patients. CPAA proves to be the optimal reconstruction option after excision of the rectum.

Adult↗