Biomedical subjects

R Santucci

Publications and source records attributed to R Santucci.

At least 19 recordsLinked to original sources

PubMed2007

A preliminary study of oscillating electromagnetic field effects on human spermatozoon motility.

Some effects of extremely low frequency electromagnetic fields (ELF-EMFs) on human spermatozoa are reported. Significant increases in the values of the motility and of the other kinematic parameters have been observed when spermatozoa were exposed to an ELF-EMF with a square waveform of 5 mT amplitude and frequency of 50 Hz. By contrast, a 5 mT sine wave (50 Hz) and a 2.5 mT square wave (50 Hz) exposure did not produce any significant effect on sperm motility. The effects induced by ELF-EMF (50 Hz; 5 mT) during the first 3 h of exposure persisted for 21 h after the end of the treatment. These results indicate that ELF-EMF exposure can improve spermatozoa motility and that this effect depends on the field characteristics.

Cells, Cultured↗

PubMed2006

The inhibition of the human sperm phosphatidylinosytol 3-kinase by LY294002 does not interfere with sperm/oocyte interaction.

It has recently been reported that the selective inhibition of phosphatidylinosytol 3-kinase (PI3K) enhances human sperm motility. However, little information exists on a possible role of PI3K in other sperm functions involved in the fertilization process. In this study, we investigated whether LY294002 could affect human sperm ability to fuse with oocytes, by means of the hamster egg penetration test (HEPT). The effect on acrosome reactions (AR) and on sperm/zona pellucida (ZP) binding was also evaluated. The pre-incubation with scalar doses of LY294002 (0.1, 1 and 10 microm) did not interfere with sperm ability to fuse with oocytes either in the conventional version of the HEPT or in the version enhanced with progesterone (P). No interference with the stimulatory effect on AR exerted by P or mannose-bovine serum albumin (mannose-BSA) was revealed. Finally, LY294002 had no effect on sperm/ZP binding. These results indicate that the inhibition of PI3K by LY294002 does not interfere with sperm interaction with oocytes. This is noteworthy in the view of a possible clinical use of LY294002 as an in vitro stimulator of the sperm motility of asthenozoospermic patients for assisted reproduction techniques.

Acrosome Reaction↗

PubMed2006

Porcine small intestinal submucosa is not an ideal graft material for Peyronie's disease surgery.

PURPOSE: The incidence of Peyronie's disease is up to 7% in some series. While there are numerous nonsurgical methods of treatment, they do not have a high rate of success. Nesbit plication was once the accepted surgery for Peyronie's disease. Tunical lengthening procedures became popular because they avoided penile shortening caused by the Nesbit procedure. More urologists now perform plaque incision or excision, followed by grafting with different materials. Small intestinal submucosa offered promise as an ideal graft material. It is available off the shelf as 1 or 4-ply graft material. In several studies it appeared to function as a collagen based scaffold with graft incorporation in host tissue. MATERIALS AND METHODS: A single reconstructive urologist performed plaque incision and small intestinal submucosa grafting in 4 cases of Peyronie's disease using the same surgical technique. RESULTS: Although early results were positive, we have achieved less than satisfactory results with this material. The penis was straight in the immediate postoperative period but there was recurrent curvature in 3 of the 4 patients, of whom 2 had recurrence within 4 months of the procedure. CONCLUSIONS: We observed disappointing results with small intestinal submucosa for Peyronie's disease surgery with a high percent of recurrent curvature. Further studies are needed to determine if 1 or 4-ply small intestinal submucosa is an ideal graft material for the tunica albuginea.

Animals↗

PubMed2005

Monoclonal antibody c262 counteracts the stimulatory effect of progesterone on sperm-oocyte fusion.

Some evidence suggests that the non-genomic effects exerted by progesterone (P) on human spermatozoa are mediated by membrane receptor(s) displaying the C-terminal domain, but not the N-terminal domain of the genomic P receptor (PR). This study aimed at determining whether the monoclonal antibody (mAb) c-262, directed against the C-terminal domain of the genomic PR, counteracts the stimulatory effect of P on the human sperm ability to fuse with oocytes. Sperm/oocyte fusion was evaluated by means of the hamster egg penetration test. The brief exposure of capacitated spermatozoa to P produced a stimulatory effect on sperm/oocyte fusion. mAb c262 counteracted this stimulatory effect in a dose-dependent manner. No counteraction was observed when capacitated spermatozoa were pre-exposed to PGR-312, a mAb directed against the N-terminal domain of the genomic PR. These results reinforce the hypothesis that the non-genomic effects exerted by P on human spermatozoa are mediated by membrane receptor(s) displaying the C-terminal domain, but not the N-terminal domain of the genomic PR.

Antibodies, Monoclonal↗

PubMed2004

Expression of gp20, a human sperm antigen of epididymal origin, is reduced in spermatozoa from subfertile men.

gp20, a sialylglycoprotein of human sperm homologous to CD52, is present everywhere on the surface of the freshly ejaculated sperm but is prevalently localized in the equatorial region of the head of capacitated sperm. In the present study, we confirmed this feature on large scale and correlated equatorial exposure of the antigen to the presence of serum albumin (SA) in the capacitation medium. Furthermore, we analyzed the relationship between the presence of the antigen and its equatorial exposure after capacitation and fertility, by comparing immunostaining for gp20 in the motile fraction of spermatozoa from fertile and subfertile men. A significantly higher percentage of nonimmunostained spermatozoa before capacitation (38.5% +/- 23 vs. 12% +/- 7, P < 0.0001) and a lower increase in the percentage of sperm with equatorial localization after capacitation (19.3% +/- 25 vs. 34.6% +/- 22, P = 0.039) were observed in subfertile men (n = 60) compared to fertile men (n = 15). In the whole study group, a positive correlation was also found between the percentage of spermatozoa exhibiting equatorial localization in capacitated samples and normal head forms (R = 0.50; P < 0.0001).

Adult↗

PubMed2003

Evaluation of the effect of 17alphaOH-progesterone and 17beta-oestradiol on human sperm ability to fuse with oocytes: comparison and possible interference with the effect of progesterone.

The demonstration of a stimulatory effect of progesterone (P) on the sperm/oocyte fusion has provided the most relevant biological evidence of the effect of P on sperm functions involved in fertilization. Some evidence exists that 17alpha-hydroxyprogesterone (17alphaOH-P) and 17beta-oestradiol (17beta-E2), could also exert non-genomic effects on human spermatozoa and a role for 17beta-E2 as a possible physiological modulator of P action on spermatozoa has been suggested. This study aimed to determine the effect of the exposure of human spermatozoa to 17alphaOH-P and 17beta-E2 on sperm/oocyte fusion as well as the possible interference of 17beta-E2 with the effect of P. The effect of steroids on sperm/oocyte fusion was assessed by means of the hamster egg penetration test (HEPT). The exposure of capacitated sperm suspensions to scalar doses of 17alphaOH-P produced a significant enhancement of penetrations/oocytes with a dose/response effect. It was equal to 75.3% of that produced by equimolar doses of P. Conversely, 17beta-E2 (from 100 nM to 50 microM) did not produce any significant effect when added either before or after capacitation. Moreover, the sperm pre-incubation with 17beta-E2 did not interfere with the stimulatory effect of P. These results support a physiological role for 17OH-P in the process of fertilization, but not a role for 17beta-E2 as a possible physiological modulator of P action on spermatozoa.

17-alpha-Hydroxyprogesterone↗

PubMed2002

Local dynamic properties of the heme pocket in native and solvent-induced molten-globule-like states of cytochrome c.

We report the Soret absorption band, down to cryogenic temperature, of native and molten-globule-like state of horse heart cytochrome c. The band profile is analyzed in terms of vibronic coupling of the heme normal modes to the electronic transition in the framework of the Franck-Condon approximation. From the temperature dependence of the Gaussian broadening and of the peak position, we obtain information on the 'bath' of low frequency harmonic motions of the heme group within the heme pocket. The reported data indicate that, compared to the native state, the less rigid tertiary structure of the molten globule is reflected in a higher flexibility of the heme pocket and in greater conformational disorder, allowing the transduction of large-amplitude motion of the protein to the dynamics of the heme pocket.

Binding Sites↗

PubMed2002

Cancer surveillance in ulcerative colitis: critical analysis of long-term prospective programme.

BACKGROUND: Patients with longstanding ulcerative colitis are at increased risk of colorectal cancer. In the literature, no agreement has yet been reached regarding prevention strategies. Our report sums up a prospective study started in 1980. METHODS: A total of 65 patients affected by ulcerative colitis for more than seven years were admitted to a regular colonoscopic and biopsy follow-up programme. RESULTS: Some 20 years after the beginning of the study, 23 (35.3%) patients have been operated upon, 2 patients have died but not from cancer 29 (44.66%) patients have abandoned the programme. Only 11 (16.9%) patients have remained under colonoscopic surveillance. CONCLUSION: These results cast some doubts on the significance of such a programme and on its long-term feasibility.

Aged↗

PubMed2002

Effect of human sperm exposure to progesterone on sperm-oocyte fusion and sperm-zona pellucida binding under various experimental conditions.

In this study, the effect of human sperm exposure to progesterone on sperm/oocyte fusion, using the hamster egg penetration test, and on sperm/zona pellucida (ZP) binding, using the hemizona assay, was investigated under various experimental conditions. A brief exposure of human spermatozoa to progesterone exerted a stimulatory effect on sperm/oocyte fusion which was dose-dependent, capacitation-dependent, influenced by the source of serum albumin in capacitating medium, and was higher than that produced by the exposure to progesterone from the onset of capacitation. The exposure of capacitated spermatozoa to progesterone during 20 min-spermatozoa/ZP-coincubation produced an enhancement of ZP-binding, which was not significantly influenced by the source of serum albumin in capacitating medium. A significantly lower ZP-binding was exhibited by spermatozoa exposed to progesterone from the beginning of capacitation. These results indicate that progesterone exerts a stimulatory effect on human sperm's fertilizing ability, which occurs mainly in post-capacitation events directly involved in sperm/oocyte fusion and in ZP-binding. Conditions optimizing these effects are provided. They should be taken into account in the standardization of experimental and clinical studies designed to evaluate the response of human spermatozoa to progesterone.

Animals↗

PubMed2002

Interactive effect of semen and cervical mucus quality on postcoital test outcome: analysis from an andrological point of view.

This study analysed the relationship between semen quality and the postcoital test (PCT) outcome in 616 couples, especially focusing on the interactive effect of semen and cervical mucus quality. When PCTs performed in the presence of unfavourable mucus were excluded, a significant correlation was found between semen parameters and PCT outcome. In oligo/asthenozoospermia, 46.7% of PCT outcomes were negative, while the remaining were positive. Notably, in the presence of an optimal mucus score, 39% of PCT outcomes were good (> or = 7 forward motile spermatozoa/high power field). In normozoospermia, 16% of PCT were negative. A suboptimal cervical mucus quality significantly affected the PCT outcome in the presence of oligo/asthenozoospermia, but not in normozoospermia. In couples with repeated PCT, a better mucus score was associated with a significant improvement of the PCT outcome. When the outcome of two PCTs performed in the same couples with an unmodified mucus score was compared, a good consistency of the results was observed. In conclusion, the PCT can provide information in additional to that obtained from conventional semen analysis, as the interactive effect of semen/cervical mucus cannot be accurately inferred from the separate evaluation of the two members of a couple.

Cervix Mucus↗

PubMed2001

Extramammary Paget's disease of the penis and scrotum: excision, reconstruction and evaluation of occult malignancy.

PURPOSE: We describe treatment and reconstruction in patients after surgery for extramammary Paget's disease of the penis and scrotum. We also investigated whether this disease causes an increased risk of undiagnosed visceral malignancy. MATERIALS AND METHODS: We reviewed the databases at our institution from 1996 to 2000 and identified 6 men 67 to 87 years old (mean age 76). In addition, we reviewed the literature on the clinical and pathological features of this disease. RESULTS: In our 6 patients scrotal involvement was present in 83% and penile extramammary Paget's disease was present in 33%. Each man underwent wide local excision and large skin defects were immediately reconstructed with split-thickness skin grafts. In 1 case extramammary Paget's disease had spread to the superficial inguinal nodes. At a mean followup of 29 months there has been no local recurrence and internal malignancy has not been diagnosed. Our literature review revealed 13 patients with penoscrotal extramammary Paget's disease and visceral malignancy, including 12 (92%) with malignancy of the genitourinary system. CONCLUSIONS: Extramammary Paget's disease of the penis and scrotum is a rare disease that can be managed by excision and immediate reconstruction with skin grafting or a local skin flap. Disease may spread to the regional lymph nodes. Although genitourinary cancer may accompany penoscrotal extramammary Paget's disease, an extensive search for cancer of the thorax or abdomen may be unnecessary because only 1 reported case of colon cancer has been associated with penile or scrotal extramammary Paget's disease.

Aged↗

PubMed2001

An electrochemical multienzymatic biosensor for determination of cholesterol.

This paper describes an electrochemical biosensor for free cholesterol monitoring. The sensor is a multienzymatic electrodic system in which horseradish peroxidase and cholesterol oxidase are simultaneously immobilized within a polymeric film, on the surface of a pyrolitic graphite electrode. From voltammetric and amperometric (flow-injection) data obtained, the efficiency, reproducibility and stability of the system are discussed. Results obtained, of interest for basic and applied biochemistry, represent a first step for construction of a mediator-free biosensor with potentialities for a successful application in the biosensor area.

Biosensing Techniques↗

PubMed2001

Cytochrome c reconstituted from two peptide fragments displays native-like redox properties.

Recombination of two fragments of horse cytochrome c (the heme-containing N-fragment, residues 1-56, and the C-fragment, residues 57-104), which are substantially unstructured at neutral pH, gives rise to a 1:1 fragment complex with a compact conformation, in which the alpha helical structure and the native Met80-Fe(III) axial bond are recovered. With respect to the native protein, the ferric complex shows a less rigid atomic packing and a decreased stability [Delta(DeltaG(o))D = 14.7 kJ.mol(-1)], ascribed to perturbations involving the Trp59 microenvironment and, to a lower extent, the heme pocket region. The redox potential, E1/2 = 234 +/- 5 mV vs. normal hydrogen electrode at 25 degrees C, is close to that of the intact protein, consistent with recovery of the native Met80-heme Fe(III) axial bond. Furthermore, the fragment complex shows reactivity similar to intact cytochrome c, in the reaction with cytochrome c oxidase. We conclude that the absence in the complex of some native cross-links and interlocked packing important for protein rigidity and stability is not as relevant for maintaining the native redox properties of the protein, provided that some structural requirements (i.e. recovering of the native-like alpha helical structure) are fulfilled and coordination of Met80 to the heme-iron is restored.

Animals↗

PubMed2001

Activity and mechanism of the antioxidant properties of cyanidin-3-O-beta-glucopyranoside.

In the present study, the antioxidant activity, the interaction with reactive oxygen species and the redox potential of cyanidin-3-O-beta-glucopyranoside (C-3-G), the main anthocyanin present in juice of pigmented oranges, were evaluated in detail. C-3-G effects on low density lipoproteins (LDL) oxidation induced by 40 microM Cu at a pH of 7.4 were compared with those of resveratrol and ascorbic acid, two other natural antioxidants. All cyanidin-3-O-beta-glucopyranoside concentrations used (1, 2, 5, 10, 20, 50, 100 and 200 microM) inhibited malondialdehyde (MDA) generation (an index of lipid peroxidation), the inhibition being significantly higher than that obtained with equal concentrations of resveratrol and ascorbic acid (IC50 = 6.5 microM for C-3-G, 34 microM for resveratrol and 212 microM for ascorbic acid). Experiments of LDL oxidation performed at a pH of 5.0 or 6.0 showed that C-3-G antioxidant activity is not influenced by pH variations between 5.0 and 7.4. This suggests that metal chelation, exerted by C-3-G through the eventual dissociation of its phenolic groups, plays a minor role in its protective mechanism. The presence of C-3-G produced significantly higher protective effects of pigmented orange juice (obtained from Moro cultivar) with respect to blond orange juice, when tested on copper-induced LDL oxidation. The evaluation of the direct interaction with reactive oxygen species (H2O2, -O2, OH*), demonstrated that C-3-G is quickly oxidized by these compounds and it is, therefore, a highly efficient oxygen free radical scavenger. The powerful C-3-G antioxidant activity is in excellent agreement with the very negative redox potential (-405 mV), determined through direct current cyclic voltammetry measurements. On the basis of these results, C-3-G should be considered as one of the most effective antioxidants that can be assumed with dietary plants; therefore, pigmented oranges represent a very relevant C-3-G source because of the high content of this anthocyanin in their juice.

Anthocyanins↗

PubMed2001

Cold single-strand conformation polymorphism analysis: optimization for detection of APC gene mutations in patients with familial adenomatous polyposis.

Over 200 adenomatous polyposis coli (APC) gene mutations have been described in familial adenomatous polyposis (FAP) patients. Recent single-strand conformation polymorphism (SSCP) screening methods have introduced minigel runs, simple ethidium bromide staining and external temperature control without any loss of sensitivity (cold-SSCP). In order to test the effectiveness in APC mutation detection, cold-SSCP was employed following polymerase chain reaction (PCR) amplification in three patients with FAP. Different running parameter combinations were compared. The three mutations already known were all diagnosed by cold-SSCP. The gel concentration was found to be essential in detecting the single-base substitution in fragments of different lengths. The observation of deletions was not affected by gel concentrations and heteroduplex bands were always produced. The temperature or glycerol addition did not significantly affect sensitivity. This modified cold-SSCP method provides a simple and effective way for detecting several known Apc gene mutations without any loss of sensitivity and could be useful for large-scale molecular diagnosis of FAP.

Adenomatous Polyposis Coli↗

PubMed2000

Anion size modulates the structure of the A state of cytochrome c.

Several studies have shown that anions induce collapse of acid-denatured cytochrome c into the compact A state having the properties of the molten globule and that the anion charge is the main determinant for the A state stabilization. The results here reported show that the anion size plays a role in determining the overall structure of the A state. In particular, small anions induce formation of an A state in which the native Met80-Fe(III) axial bond is recovered and the nativelike redox properties restored. On the other hand, the A state stabilized by large anions shows a histidine (His26 or His33) as the sixth ligand of the heme-iron, a very weak interaction between Trp59 and the heme propionate, and lacks nativelike redox properties. The two anion-stabilized states show similar stability, indicating that (i) the hydrophobic core (which is equally stabilized by all the anions investigated, independently of their size) is the region that mainly contributes to the macromolecule stabilization, and (ii) the flexible loops are responsible for the spectroscopic (and, thus, structural) and redox differences observed.

Animals↗

PubMed2000

The heme-containing N-fragment (residues 1-56) of cytochrome c is a bis-histidine functional system.

The structural and redox properties of a heme-containing fragment (1-56 residues) of cytochrome c have been investigated by spectroscopic (circular dichroism, electronic absorption, and EPR) and voltammetric techniques. The results indicate that the N-fragment lacks ordered secondary structure and has two histidines axially bound to the heme-iron (the native His18 and a misligated His26 or His33). Despite the absence of ordered secondary structure, the peptide chain shields the heme group from solvent, as shown by (i) the pK(a) of protonation of the nonnative histidine ligand (5.18 +/- 0.05), lower than that of the bis-histidine guanidine-unfolded cytochrome c (5.58 +/- 0.05), and (ii) the redox potential, E(o) = 0 +/- 5 mV versus NHE, close to that of bis-histidine cytochrome c mutants but less negative than that of bis-histidine complexes of microperoxidase with short peptides. The electroactive N-fragment may be taken as a "minichrome c" model, with interesting potential for application to biosensor technology; further, the system provides useful information for a deeper understanding of cytochrome c folding and structural/functional organization.

Animals↗

PubMed2000

Redox equilibria of manganese peroxidase from Phanerochaetes chrysosporium: functional role of residues on the proximal side of the haem pocket.

Redox potentials of recombinant manganese peroxidase from Phanerochaetes chrysosporium have been measured by cyclic voltammetry as a function of pH, between pH 4.5 and pH 10.5. They display a bimodal behaviour (characterized by an 'alkaline' and an 'acid' transition), which indicates that (at least) two protonating groups change their pK(b) values upon reduction (and/or oxidation) of the iron atom in haem. Analogous measurements have been carried out on four site-directed mutants involving residues in close proximity to the proximal ligand, His(173), in order to investigate the role played by residues of the proximal haem pocket on the redox properties of this enzyme. Results obtained suggest that the protonation state of N(delta) of the proximal imidazole group is redox-linked and that it is crucial in regulating the 'alkaline' transition. On the other hand, none of the proximal mutants alters the 'acid' transition, suggesting that it is modulated by groups located in a different portion of the protein.

Electrochemistry↗