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E Greco

Publications and source records attributed to E Greco.

At least 55 records · Page 3Linked to original sources
PubMed1998

Treatment of severe male infertility by micromanipulation-assisted fertilization: news and views.

Recent progress in cell micromanipulation has made it possible to achieve fertilization even with highly deficient male gametes, by injecting them directly to oocyte cytoplasm. This technique, known as intracytoplasmic sperm injection (ICSI), has proved efficient in most types of sperm pathology. However, ICSI fails when injected spermatozoa are not capable of supporting the process of oocyte activation or when they carry genetic abnormalities incompatible with normal embryonic development. Abnormalities of oocyte activation and the transmission of genetic anomalies to the progeny are also two major concerns relating to the clinical use of ICSI. The use of micromanipulation-assisted fertilization in cases of male germ cell maturation arrest, namely fertilization by round spermatid injection (ROSI), has brought preliminary clinical results, and the improvement of ROSI clinical efficacy remains a major challenge for future research.

Acrosome Reaction↗
PubMed1998

Differentiation of spermatogenic cells during in-vitro culture of testicular biopsy samples from patients with obstructive azoospermia: effect of recombinant follicle stimulating hormone.

In-vitro differentiation of spermatogenic cells is a potential approach to the treatment of male sterility due to spermatogenic arrest. This is a pilot study evaluating meiotic, morphogenetic and cytoplasmic maturation of spermatogenic cells from 18 patients with obstructive azoospermia, during in-vitro culture of partly disintegrated testicular biopsy samples in the presence or absence of recombinant follicle stimulating hormone (rFSH). Meiotic progression was detectable only in the presence of rFSH in culture medium. FSH-dependent condensation, peripheral migration and protrusion of spermatid nuclei, together with FSH-independent flagellar growth, were the main events indicating post-meiotic sperm cell differentiation. rFSH also promoted the progression of spermatid cytoplasmic maturation, reflected by acceleration of acrosomal development. These differentiation events appeared to be mediated by humoral activity of Sertoli cells, without the need for a direct Sertoli-sperm cell contact. These findings provide a background for similar studies in patients with non-obstructive azoospermia. If reproducible in the latter group, transmeiotic in-vitro differentiation of primary spermatocytes may be useful in cases of complete maturation arrest, whereas the development of culture-specific forms may help select viable spermatids in cases of complete spermiogenesis failure.

Acrosome↗
PubMed1998

Preincubation of human oocytes may improve fertilization and embryo quality after intracytoplasmic sperm injection.

The aim of this study was to examine the relationship between different preincubation periods of oocytes and the outcome of intracytoplasmic sperm injection (ICSI). We analysed retrospectively 95 ICSI treatment cycles performed to alleviate severe male-factor infertility. Oocyte collection was performed approximately 36 h after human chorionic gonadotrophin administration. The cumulus-corona-oocyte complexes obtained were incubated until the moment of ICSI. Fertilization, embryo development and implantation rates were analysed in four groups, which were divided according to the time lapse between oocyte retrieval and ICSI: group I, < or =3 h (18 cycles); group II, >3-< or =6 h (52 cycles); group III, >6-< or =9 h (14 cycles); and group IV, >9-< or =12 h (11 cycles). Immediately before ICSI the cumulus and corona cells were removed from the oocytes. A total of 723 metaphase II oocytes were injected: 126 from group I, 380 from group II, 126 from group III and 91 from group IV. The fertilization rates obtained were 52.3, 66.8, 65.1 and 69.2% respectively [P < 0.05 (using the chi2 test) between group I and groups II, III and IV]. Cleavage rates were similar in all groups (68.1, 69.7, 79.2 and 79.3% respectively), but the proportion of good quality embryos (< or =20% fragmentation) was significantly lower (P < 0.05) in group I (24.2%) compared with groups II (39.8%) and IV (39.6%). However, no statistically significant differences were observed between the four groups with regard to implantation rates (11.7, 13.2, 10.4 and 20.4% respectively). The results suggest that a preincubation period between oocyte retrieval and ICSI can improve the fertilization rate and embryo quality. This period might be necessary for some oocytes to reach full cytoplasmic maturity, leading to a higher activation rate upon microinjection.

Cellular Senescence↗
PubMed1998

Spermatids as gametes: indications and limitations.

The feasibility of achieving viable embryos, developing to term after transfer into the uterus, by fertilizing oocytes with spermatids has been demonstrated both in animal studies and in preliminary human clinical trials. Here we review the current clinical indications of spermatid conception and discuss the predictable success rates associated with each of these indications. Potential health hazards relating to the use of spermatids for conception are updated taking into account the risk of abnormal or incomplete epigenetic modifications of newly discovered human imprinted genes. We also add new experimental data showing the occurrence of spermatids in patients lacking spermatozoa and demonstrating that round spermatids recovered from patients with complete spermiogenesis failure (no elongated spermatids or spermatozoa ever detected in the patient's history) are often deficient in the factor(s) responsible for oocyte activation. The possible consequences of this deficiency for the occurrence of abnormal fertilization patterns and for the impairment of further preimplantation and post-implantation development are discussed. It is concluded that the development of diagnostic tests to assess the intrinsic quality of spermatids, with regard to their ability to act as gametes, is urgently needed as part of pre-treatment diagnosis before infertile couples are included in a spermatid conception programme. Centres wishing to use spermatids in human assisted reproduction should also be prepared to offer adequate diagnostic methods to control genomic imprinting abnormalities in the progeny.

Female↗
PubMed1998

Germ cell apoptosis in men with complete and incomplete spermiogenesis failure.

Germ cell apoptosis was evaluated in 11 men suffering from nonobstructive azoospermia and enrolled in a spermatid conception programme. In six of these patients, round spermatids (Sa stage) were the most advanced spermatogenic cells recovered from testicular biopsy samples. This condition is referred to as complete spermiogenesis failure. In the remaining five men, a few late elongated spermatids (Sd stage) were unexpectedly found in the testicular biopsy samples on the day of treatment. This condition is referred to as incomplete spermiogenesis failure. Germ cell apoptosis in both groups of patients was examined by analysing cell smears prepared from mechanically disintegrated testicular tissues using terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL), which detects apoptosis-specific DNA fragmentation, and annexin-V binding, detecting apoptosis-related translocation of plasma membrane phosphatidylserine to the membrane's outer surface. Both methods were combined, in double-fluorescence labelling preparations, with immunocytochemical detection of proacrosin, a specific germline marker. Patients with complete spermiogenesis failure had significantly higher frequencies of primary spermatocytes and round spermatids carrying the apoptosis-specific DNA damage in comparison with patients with incomplete spermiogenesis failure. Surprisingly, apoptosis-related phosphatidylserine externalization occurs rarely until the advanced stages of spermiogenesis. Since externalized phosphatidylserine is expected to be involved in the recognition of apoptotic cells by phagocytes, apoptotic spermatocytes and round spermatids may not be removed easily by phagocytosis. The high frequency of DNA damage in round spermatids from patients with complete spermiogenesis failure explains the low success rates of spermatid conception in these cases. The evaluation of apoptosis can help predict success rates of spermatid conception.

Annexin A5↗
PubMed1998

Analysis of Helicobacter pylori vacA and cagA genotypes and serum antibody profile in benign and malignant gastroduodenal diseases.

BACKGROUND: Helicobacter pylori species comprise different strains, cytotoxic and non-cytotoxic, which can be identified on the basis of their genomic pattern. AIMS: (1) To evaluate the polymorphism of the vacA gene and to ascertain whether the cagA gene is present in patients with gastric adenocarcinoma. (2) To study the anti-H pylori antibody profile using western blotting. PATIENTS: Twenty one patients with gastric adenocarcinoma and 71 with H pylori associated benign disease (nine gastric ulcer, 29 duodenal ulcer, 25 antral gastritis, and eight duodenitis). METHODS: The polymerase chain reaction was used to verify the presence or absence of cagA and to study the polymorphism of vacA in gastric mucosal samples obtained during endoscopy for patients with benign diseases and at surgery for patients with gastric adenocarcinoma. Fasting sera were used to assess anti-H pylori antibodies against different H pylori antigens by western blotting. RESULTS: CagA gene and the allele s1 of vacA were significantly less frequent in patients with antral gastritis (60% and 60%) compared with patients with gastric adenocarcinoma (94% and 100%) and with other non-malignant gastroduodenal diseases (93% and 87%) (chi 2 = 16.01, p < 0.001; and chi 2 = 13.97, p < 0.01). In patients with gastric adenocarcinoma, antibodies against a 74 kDa H pylori antigen were less frequently found than in patients with benign diseases. CONCLUSIONS: H pylori infection caused by cagA positive/vacA s1 strains is a frequent finding in patients with gastric adenocarcinoma. Prospective studies are needed to confirm whether the low incidence of positive serological response to the 74 kDa H pylori antigen in patients with gastric adenocarcinoma is important.

Adenocarcinoma↗
PubMed1998

Human spermatogenesis in vitro: respective effects of follicle-stimulating hormone and testosterone on meiosis, spermiogenesis, and Sertoli cell apoptosis.

In spite of the availability of abundant data about in vitro spermatogenesis in laboratory animals, studies on human in vitro spermatogenesis are scarce. This study employed a relatively simple culture system, involving all cell types of seminiferous tubules, to analyze the effects of FSH and testosterone (T) on different characteristics of human germ and Sertoli cells in culture. By using fluorescence in-situ hybridization, we show that in vitro reduction of germ cell ploidy can be stimulated by FSH but not by T. FSH, but not T, also induced unexpectedly rapid (24-48 h) morphological changes resembling spermiogenesis, although individual changes (spermatid nucleus condensation and protrusion, cell body elongation, and flagellar growth) proceeded in an uncoordinated way and mostly resulted in the development of abnormal forms of elongated spermatids. Though ineffective alone, T potentiated the effects of FSH on meiosis and spermiogenesis. These effects of T were probably caused by the prevention of Sertoli cell apoptosis, an effect that could not be mimicked by FSH. These data show that, in the presence of high concentrations of FSH and T, human spermatogenesis can proceed in vitro with an unusual speed, but the resulting gametes are morphologically abnormal. The potential practical relevance of these findings to assisted reproduction remains to be assessed.

Adult↗
PubMed1996

Heparin-coated circuit in coronary surgery. A clinical study.

We performed a randomized study in 101 patients who underwent routine isolated coronary bypass graft surgery. In 50 cases an entire coated Carmeda circuit was used (coated group), and an uncoated circuit in the remaining 51 (uncoated group). A Medtronic Maxima oxygenator and a Biomedicus Biohead were used in all cases. Patients with coated circuits received low systemic heparinization with a heparin loading dose of 200 IU/kg, and 300 IU/kg for the control. Activated coagulation time was maintained at more than 275 s for the coated group versus more than 400 s for the uncoated one. The mean age of patients was 64.1 +/- 9.6 for coated and 63.5 +/- 9.7 for the uncoated group. The number of coronary grafts was 3.1 +/- 0.7 for the coated group and 3.1 +/- 0.1 for the uncoated one. Cross-clamp and bypass times were 53 +/- 14 and 98 +/- 24 min for the coated, versus 57 +/- 15 and 104 +/- 24 for the uncoated, group. Chest drainage was 989.4 +/- 509.5 ml for the coated group versus 1435 +/- 1027 for the uncoated one (P < 0.02). The amount of transfused homologous blood was 723 +/- 597 ml for the coated group versus 1071 +/- 831 ml for the uncoated one (P < 0.03). Postoperative endotracheal intubation time was 12.1 +/- 3.6 h for the coated and 14.6 +/- 4.5 h for the uncoated group (P < 0.05). Bleeding required rethoracotomy in 1/50 of the coated group, and in 4/51 of the uncoated one. Hospital mortality was 1/50 in the coated, and 4/51 in the uncoated, group. In our preliminary experience, heparin coating of an extracorporeal circuit reduces post-operative blood loss and blood transfusions in routine coronary bypass operations.

Aged↗
PubMed1995

Nitric oxide release during hypothermic versus normothermic cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) produces hemodynamic and inflammatory disorders involving changes in vascular permeability and regional blood flow and alterations of coagulation and complement systems. It has been reported that an abnormal release of vasoactive substances during CPB, like bradykinin or nitric oxide, could play a role. The aim of this study was to investigate the changes in nitric oxide (NO) release occurring in patients undergoing CPB, under both hypothermic and normothermic conditions. Forty patients (mean age 61.4 +/- 8.4 years) undergoing coronary bypass surgery were studied. In 20 patients (group A) systemic hypothermic CPB and antegrade cold intermittent crystalloid cardioplegia were used. The remaining 20 cases (group B) underwent surgery under systemic normothermic CPB and with antegrade warm blood intermittent cardioplegia. Nitric oxide was measured as the nitrite plasma level (NPL) by the Gries reaction. The time course of changes in NPL were obtained by collecting five whole blood samples: before CPB, 10 and 30 min after the start of CPB, and 10 and 60 min after the end of CPB. Although there were no significant variations of NPL shortly after the start of CPB (10 min after), values measured 30 min after CPB commencement and 10 min after the end of CPB showed a significant increase (P < 0.0001) in both groups. Considering the two groups separately, NPL changes seemed to be similar, so independent of temperature; however, in group B higher values of NPL were measured during (30 min) and after (60 min) CPB (P < 0.0001). In conclusion, during CPB there is a progressive increase, independent of temperature in NO release.

Blood Pressure↗
PubMed1995

Combined coronary bypass grafting and mitral valve surgery: Early and late results.

It is reported that the mortality rate for combined coronary bypass grafting and mitral valve replacement is greater than for either isolated operation. To evaluate the effects of various predicting factors we analyzed the results of 67 consecutive patients undergoing combined mvr and CABG. The mean age was 61.3 +/- 7 years. There were 55 males and 12 females and the mean follow-up was 59.4 +/- 7 months. The hospital mortality rate was 13.4% (9/67). Preoperative NYHA functional class (p<0.05), left-ventricular motion score (increased scores indicating impaired function, (p<0.05), and aortic cross-clamp time (p<0.05) were associated with hospital mortality. There was no significant relationship of age (>60), cause of mitral valve disease, severity of mitral regurgitation, number of grafts, or previous myocardial infarction with hospital mortality. There were 7 late deaths, and survival at five years was 76.1%. Although there was a trend for preoperative NYHA class and aortic cross-clamp time to be associated with late survival, the only factor significantly related to late survival was global wall-motion score (p<0.05). Severity of mitral regurgitation and cause of mitral valve disease have been reported as being related to late survival, but we have found no such relationship. Our results indicate that both hospital and late mortality are strongly correlated with preoperative left ventricular function.

Adult↗
PubMed1995

Styles of regulation in the bipolar spectrum.

Styles of regulation were assessed with the Serial Color-Word Test in a group of 35 compensated DSM-III--R bipolar patients (Bipolar) and in 3 control groups: Major Depression (n = 35), Schizophrenia (n = 50), and self-rated Personality Disorder (n = 40). On several measures of nonlinear change (V), patients in the Bipolar group had mean scores between those of the Personality Disorder and the Schizophrenic groups, and overlapped with those of the Major Depression group. Patients in the Bipolar group with clearcut temperaments (hyperthymic or depressive) were significantly more dissociative and less stabilized than other patients in the same group. A further group of nonclinical subjects with hyperthymic temperament (n = 20) was significantly more dissociative than the Personality Disorder group.

Adolescent↗
PubMed1995

Left thoracotomy for coronary revascularization after esophagoplasty with substernal colon interposition.

A 66-year-old man was referred to our institution with recurrent angina pectoris caused by 95% stenosis of the left anterior descending coronary artery. Twelve years earlier, he had undergone esophagoplasty with substernal colon interposition for an esophageal burn caused by a caustic substance. A left thoracotomy approach and femoro-femoral bypass were used safely for coronary artery revascularization.

Aged↗