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Biomedical subjects

F Dondero

Publications and source records attributed to F Dondero.

At least 19 recordsLinked to original sources
PubMed2006

Cryopreservation and sperm DNA integrity.

Cryopreservation of sperm is an extremely important issue in the field of male infertility as freezing can have detrimental effects on a variety of sperm functions, some of them not accessible to the traditional semen quality analysis. In this study, chromatin structure variations in human spermatozoa in semen were studied with the sperm chromatin structure assay (SCSA), both before and after cryopreservation. Samples were divided into two aliquots: the first was analysed without further treatment, while the second was stored in liquid nitrogen at -196 degrees C using standard cryopreservation techniques. The fresh and thawed aliquots were also assessed by light and fluorescence microscopy (after Acridine Orange staining, AO), and computer-assisted semen analysis (CASA) of motility. Overall sperm quality was found to deteriorate after cryopreservation. When thawed spermatozoa were subjected to an extra swim-up round, a general improvement in nuclear maturity was seen in post-rise spermatozoa.

Acridine Orange↗
PubMed2005

Presence of membrane and soluble forms of Fas ligand and of matrilysin (MMP-7) activity in normal and abnormal human semen.

BACKGROUND: The aim of this study is to shed some light on the role of the Fas system in human semen, by investigating whether there is an association between the expression of the molecules regulating the Fas system [membrane-bound Fas ligand (mFasL), soluble Fas ligand (sFasL) and matrilysin, the metalloprotease cleaving mFasL to sFasL] and sperm parameters. METHODS: We investigated, by flow cytometric analysis, the presence of FasL on spermatozoa from normozoospermic and teratozoospermic subjects and, by western blot, the presence of sFasL and matrilysin in the seminal plasma of the same samples as well as on samples from azoospermic subjects. The enzymatic activity of matrilysin was examined by gel zymography. RESULTS: We observed that sperm cells expressed mFasL in 22% of normozoospermic men, whereas it was absent from spermatozoa from teratozoospermic patients. Higher levels of sFasL and augmented enzymatic activity of matrilysin were found in azoospermic samples. CONCLUSIONS: The presence of mFasL on sperm from normozoospermic men and its absence in pathological samples emphasize the role of the Fas system in human semen. Moreover, the presence of both sFasL and matrilysin in seminal plasma implies a fine regulation of the function of the Fas system and, consequently, of the apoptotic process in the human genital tract.

Adult↗
PubMed2005

Diagnosing erectile dysfunction: instruments for endocrine diagnosis.

Endocrine factors represent an important and potentially treatable cause of sexual dysfunction. The availability of a correct endocrinological diagnosis allows correct identification of most cases of sexual dysfunction in which the endocrine apparatus is involved. Not only the most frequent causes of endocrine sexual dysfunction, such as hypogonadism and hyperprolactinaemia, but almost all extra-gonadal endocrinopathies (hyper-and hypothyroidism, hyper- and hypocortisolism, steroidal secreting tumours, etc.) may have importance to a greater or lesser extent in sexual function. It is, therefore, necessary that the diagnostic process for sexual dysfunctions of an endocrine nature be as integrated and wide as possible, especially as such pathologies are normally extremely responsive to medical or surgical therapy.

Diagnostic Techniques, Endocrine↗
PubMed2005

Androgens and fertility.

Androgens play a pivotal role in the development of the male reproductive tract. The spermatogenesis requires high levels of intratesticular testosterone secreted by the Leydig cells. Testosterone exerts its action through the androgen receptor (AR), which is located both in the cytoplasm and in the nucleus of cells in the target tissue. Severe defects of the AR may result in abnormal male sexual development, while more subtle modifications can be a potential cause of male infertility. Low circulating levels of testosterone can be found in 20-30% of infertile men, but administration of testosterone or gonadotropins does not result in improved sperm production. Abuse of anabolic steroids is a frequent cause of male infertility, and substances such as endocrine disruptors can alter male fertility through an anti androgenic action.

Aged↗
PubMed2004

Full-term pregnancies achieved with ICSI despite high levels of sperm chromatin damage.

BACKGROUND: Sperm DNA integrity is essential for the accurate transmission of genetic information. The clinical significance of this assessment lies in its association with not only natural conception rates, but also the success of assisted reproduction technology (ART). It has been reported that sperm chromatin structure assay (SCSA) identified thresholds for negative pregnancy outcome after ART when the DNA fragmentation index (DFI), previously known as COMPalphat, was >30%. METHODS: In a prospective clinical study, we examined 34 male infertile patients, the husbands of women undergoing conventional IVF or ICSI. SCSA and ART were carried out on semen aliquots taken from the same ejaculate. Fertilization rate, embryo quality and pregnancy rates were correlated to SCSA parameters, DFI and highly DNA stainable (HDS) cells. RESULTS: No differences were seen in SCSA parameter values between patients initiating pregnancies and not doing so in either ICSI or conventional IVF. Pregnancies and normal delivery were obtained even with high levels of DFI. CONCLUSIONS: There is still controversy over whether analytical techniques currently in use are able to identify the level of damage to spermatozoa. Large-scale studies should be conducted in different clinical settings to determine the effects of sperm DNA damage on the outcome of ART.

Adult↗
PubMed2004

Might erectile dysfunction be due to the thermolabile variant of methylenetetrahydrofolate reductase?

Hyperhomocysteinemia is considered one of the most important cardiovascular risk factors increasing considerably the risk of stroke and myocardial infarction. With respect to endothelial function, direct effects of hyperhomocysteinemia on vascular endothelial cells have been demonstrated through the reduction of endothelial nitric oxide production. In this paper, we report the case of a young man with homozygote genotype mutated with 5-methylenetetrahydrofolate reductase (MTHFR) thermolabile variant who, in the absence of relational stress, developed an erectile dysfunction (ED) refractory to the vasoactive type-V phosphodiesterase (PDE5) inhibitor therapy. After one month of treatment with 5 mg/day folic acid and 1000 microg/day cyanocobalamin, the patient restarted the assumption of 50 mg sildenafil, obtaining satisfying erections during sexual intercourse. We suggest that hyperhomocysteinemia may interfere with penile blood supply and, thus, be responsible for ED. If this relationship is confirmed, plasma levels and urinary homocysteine (HCy) should be evaluated in selected young patients with vascular ED. Furthermore, careful attention should be given to the risk of ED when dealing with this metabolic disturbance.

Adult↗
PubMed2003

Heat-shock protein 70 favours human liver recovery from ischaemia-reperfusion.

BACKGROUND: Pringle's manoeuvre controls excessive bleeding, but results in ischaemia-reperfusion injury during liver surgery. Activation of the heat-shock protein system of cell defense has been demonstrated after ischaemia-reperfusion injury in animal tissues. The aim of the present study was to determine whether the ischaemia-reperfusion accompanying hepatic surgery induces heat-shock protein 70 (HSP70) in human liver and whether the induction of HSP70 is related to the recovery of liver function. METHODS: Heat-shock protein 70 and gamma-actin mRNAs were assayed in the liver biopsies of 10 subjects undergoing partial hepatectomy for localized lesions. Measurements were performed before the Pringle's manoeuvre and at the end of the surgery. Transaminases and fibrinogen were measured before and at 12, 24 and 36 h following hepatectomy. RESULTS: After an average 40 +/- 8-min period of warm ischaemia, a significant increase of HSP70 mRNA (187 +/- 67%, 2P < 0.05) was observed. The acute increase of HSP70 mRNA correlates with the decrease of transaminases (AST: rs -0.964, ALT: rs -0.891, P < 0.002) and the increase of fibrinogen (rs -0.7, P < 0.02) observed between 12 and 24 h following surgery. CONCLUSIONS: Heat-shock protein 70 is induced by ischaemia-reperfusion injury in human liver. Its induction seems to have beneficial effects, including a prompt reduction of transaminases and a rapid recovery of fibrinogen synthesis.

Analysis of Variance↗
PubMed2003

Endocrinological diagnosis in sexology.

Endocrine factors represent an important and potentially treatable cause of sexual dysfunction. The availability of a correct endocrinological diagnosis allows correct identification of most cases of sexual dysfunction in which the endocrine apparatus is involved. Not only the most frequent causes of endocrine sexual dysfunction, such as hypogonadism and hyperprolactinemia, but almost all extra-gonadal endocrinopathies (hyper- and hypothyroidism, hyper- and hypocortisolism, steroidal secreting tumors, etc.) may play a role to a greater or lesser extent in sexual function. It is therefore necessary that the diagnostic process for sexual dysfunctions of an endocrine nature be as integrated and wide as possible, especially as such pathologies are usually extremely responsive to medical or surgical therapy.

Endocrine System Diseases↗
PubMed2002

Polyunsaturated fatty acids of germ cell membranes, glutathione and blutathione-dependent enzyme-PHGPx: from basic to clinic.

The lipid metabolism in sperm cells is important both for energy production and for cell structure. A special composition of membrane phospholipids, rich in polyunsaturated fatty acids (PUFA), and the different composition of sperm and immature germ cell membrane are described and discussed. Testis germ cells as well as epididymal maturing spermatozoa are endowed with enzymatic and non-enzymatic scavenger systems to prevent lipoperoxidative damage. Catalase, superoxide dismutase, and glutathione-dependent oxidoreductases are present in variable amounts in the different developmental stages. Phospholipid hydroperoxide glutathione peroxidase (PHGPx) activity and roles in caput and cauda epididymal sperm cells are discussed. Also seminal plasma has a highly specialized scavenger system that defends the sperm membrane against lipoperoxidation and the degree of PUFA insaturation acts to achieve the same goal. Systemic predisposition and a number of pathologies can lead to an anti-oxidant/pro-oxidant disequilibrium. Scavengers, such as glutathione can be used to treat these cases as they can restore the physiological constitution of PUFA in the cell membrane.

Animals↗
PubMed2001

Improved human sperm recovery using superoxide dismutase and catalase supplementation in semen cryopreservation procedure.

The aim of this work was to evaluate the effects of ROS scavenger supplementation in human semen samples undergoing cryopreservation procedures.After screening out andrological pathologies, we selected 25 male partners of infertile couples with the following semen profile: volume >/= 2.0 ml, normal viscosity, sperm count >/=20 x 10(6)/ml, straight progressive motility (classes 1 and 2) >/= 40% (Mazzilli, Rossi, Delfino and Nofroni (1999) Andrologia 31: 187-194), atypical forms </= 70%, WBCs < 1.0 times 10(6)/ml.After liquefaction, standard semen analysis and the Hypoosmotic Viability Test (HVT) were carried out; the samples were then divided into 4 aliquots. The first was untreated as a control; 200 U/ml of superoxide dismutase (SOD) was added to the second, 200 U/ml of catalase to the third and both SOD (100 U/ml) and catalase (100 U/ml) were added to the fourth aliquot. Each aliquot was mixed (v/v) with TEST yolk buffer freezing medium (Irvine Scientific) and then frozen at -196 degrees C. The percent recovery of progressive motile and swollen spermatozoa was evaluated after thawing.No significant variation in the recovery of progressive motility was seen in the aliquots with added SOD or catalase alone, compared to the control group. On the other hand, a significant improvement in sperm parameter recovery was seen in the aliquot with both SOD and catalase supplementation; perhaps because of their combined and simultaneous action on superoxide anion and hydrogen peroxide. These results suggest that, in some selected cases, SOD and catalase supplementation can contribute greatly to the prevention of sperm membrane lipid peroxidation by ROS and thus allow good sperm parameter recovery after freezing-thawing procedures.

Journal Article↗
PubMed2001

A new objective method for scoring human sperm hyperactivation based on head axis angle deviation.

The aims of the present study were, first to develop a new method for evaluating sperm hyperactivation (HA) based on sperm head axis angle deviation, and second to apply this method in scoring selected sperm populations during capacitation. This was made possible by improving our original superimposed image analysis system (SIAS). The new option on the system enables us to determine the real angular deviation of the entire head in successive superimposed frames. The entire procedure for each spermatozoon requires 10-20 sec, according to the frame/rate utilized. A clear cut-off between the values of hyperactivated, transitional and non-hyperactivated spermatozoa was found at 11 and 21 frames/sec. However, at 6 frames/sec, a partial overlap between the three classes was found. We defined sperm activity as follows. At 11 frames/sec, hyperactivated: angle sum > or = 405 degrees; transitional: 200 degrees < or = angle sum < 405 degrees. At 21 frames/sec, hyperactivated: angle sum > or = 760 degrees; transitional: 350 degrees < or = angle sum < 760 degrees. The results, in agreement with previous research, show the peaks of activity at 3 h, dropping to a minimum at 6 h. This phenomenon was significantly more evident in fertile compared with subfertile semen samples.

Humans↗
PubMed2000

Myth and reality of the decline in semen quality: an example of the relativity of data interpretation.

Many hypotheses have been put forward to explain a suspected decline in semen quality. Up to now many sources of data were used but conflicting results are present in the literature. To study whether modifications of sperm parameters actually exist we used data from two groups of patients checked and two small groups of sperm bank donors selected at the beginning '80s and '90s. We tried to reduce bias to a minimum: all the semen analyses were carried out by the same biologist, using the same methods, groups were clinically evaluated by the same andrological team, the study groups were homogeneous for age, geographic-ethnic origin, residence, monthly-seasonal distribution and abstinence period. Comparing patients from the '80s and the '90s, sperm concentration and motility showed a significant reduction. Furthermore, the decrease in concentration and motility was mainly due to the higher age classes. In donors, no decline was observed. These results seem to indicate that sperm donors remain unaffected, while patients with lower levels of semen quality are experiencing a real decline. Unfortunately, many confounding variables, analyzed in detail in this review, still remain despite efforts at standardization.

Adult↗
PubMed2000

Chromosomal alterations and male infertility.

Reduced male fertility can be caused by genetic factors affecting gamete formation or function; in particular, chromosome abnormalities are a possible cause of male subfertility as shown by their higher frequency in infertile men than in the general male population. Meiotic studies in a number of these males have shown spermatogenesis breakdown, often related to alterations in the process of chromosome synapsis. Indeed, any condition that can interfere with X-Y bivalent formation and X-chromosome inactivation is critical to the meiotic process; furthermore, asynapsed regions may themselves represent a signal for the meiotic checkpoint that eliminates spermatocytes with synaptic errors. We performed cytogenetic, hormonal and seminal studies in 333 infertile patients selected because azoospermic, severely oligozoospermic or normozoospermic with failure to fertilize the partner's oocytes in an in vitro fertilization (IVF) program. Our findings: 1) confirm the high incidence of chromosomal anomalies among infertile males; 2) highlight the relevance in male infertility of quantitative/positional modifications of the constitutive heterochromatin; and 3) underline the relevance of cooperation between andrologists and cytogenetists prior to every kind of assisted reproduction, above all prior to intracytoplasmic sperm injection, in which selective hurdles eliminating abnormal germ cells are bypassed.

Adult↗
PubMed2000

Psychosocial factors and male seminal parameters.

The relationships between (a) alexithymia, (b) extroversion (E), neuroticism (N), psychoticism (P), (c) coping style towards stressors, and seminal parameters, were assessed in 132 males on their first seminal fluid examination by means of a multivariate approach. They were given the TAS-20, the EPQ, and the Coping Inventory for Stressful Situations (CISS). Seminal parameters were: (1) sperm concentration; (2) total sperm count; (3) forward motility; (4) atypical forms. Multiple regressions considering quantitative parameters of seminal status as criterion showed a negative relationship with P, difficulty describing feelings (DDF), while a positive relationship was found for N, and emotion-oriented coping. A discriminant analysis also showed that P, N and DDF distinguished between two groups of normozoospermic and oligozoospermic subjects with a high probability of correct classifications. Results confirm the hypothesis that biological and psychological variables are not completely independent or randomly related in people with an impaired seminal status, although the correlations between psychosocial and biological data are not very strong.

Adaptation, Psychological↗
PubMed2000

Study of apoptotic DNA fragmentation in human spermatozoa.

The aim of our work was to define and better understand apoptosis in the spermatozoa of normal subjects, infertile patients and patients affected by specific tumoral diseases employing the method of the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling and confirming the results by electron microscopy. We studied 23 healthy, normozoospermic subjects (group A), 29 oligoasthenoteratozoospermic patients, affected by various andrological pathologies (group B), 28 patients with Hodgkin's disease (C1) and 30 patients with testicular cancer (C2). Our data demonstrate that the percentage of apoptosis in normozoospermic subjects (group A) is significantly lower than in all the other groups (B, C1, C2) (P < 0.001). This confirms that high DNA fragmentation is one of the characteristics of spermatogenetic failure. The induction of apoptosis, which can also be a basic response to neoplastic disease, can even act right up to the mature male gamete. Our results suggest that apoptosis could be the final result of various pathologies and of a deregulation of spermatogenesis control systems.

Adult↗
PubMed2000

Fatty acid composition of spermatozoa and immature germ cells.

A great deal of attention has recently been given to the essential role of polyunsaturated fatty acids (PUFA) of sperm membranes. We studied the fatty acid composition of the immature germ cells (IGC) and of the sperm populations separated by Percoll gradient in the ejaculate of normozoospermic patients. Fatty acid pattern was analysed by combined gas chromatography-mass spectrometry on a capillary column. In IGC, differences were found compared with mature spermatozoa, with a higher percentage of saturated fatty acids and of essential fatty acids. On the contrary, the long-chain PUFA were significantly lower in IGC. The highest concentration of n3 PUFA docohexaenoic acid (DHA) was detected in the spermatozoa deriving from 70-100% Percoll layers and a direct linear correlation was found between the increase of DHA and increased percentage of Percoll gradient. An inverse relationship between the percentage of atypical sperm forms in each layer and the percentage of DHA was also observed. This study demonstrates that the human germ cell line can elongate and desaturate essential fatty acids and that the percentage of long-chain PUFA is correlated with the normal morphology of sperm cells.

Fatty Acids↗