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Biomedical subjects

A Lenzi

Publications and source records attributed to A Lenzi.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Lipids of the sperm plasma membrane: from polyunsaturated fatty acids considered as markers of sperm function to possible scavenger therapy.

This article is, in part, a review of present knowledge regarding the lipid metabolism of the sperm cell and the lipid composition of the sperm plasma membrane. It is also a summary of our research on this topic, reporting published and unpublished data. The article tries to cover both basic and clinical research. Sperm cells use lipid metabolic pathways for the production of part of their energy. The double leaflets of the membrane are not simply a passive, bilayer, lipidic film in which the receptors receive their molecular specific signals, but are a very specialized structure. Complete maturation of the lipids of the sperm cell membrane is reached after passage of the spermatozoon through the epididymis. A specific composition of phospholipids and a significant concentration of polyunsaturated fatty acids (PUFA) have been shown to be present in sperm membranes. Plasmalogen is a special kind of phospholipid found exclusively in spermatozoa and other cells with the capacity to react promptly to stimuli. In addition, we have found a high concentration of the n-3 PUFA family in the sperm membrane. Seminal plasma has a highly specialized scavenger system that defends the sperm membrane against lipoperoxidation. Various pathologies and systemic predisposition can lead to an antioxidant/pro-oxidant disequilibrium. Clinical trials with natural scavengers could be a useful research area in which to seek a treatment for these pathologies. Of the natural scavengers, glutathione has been shown to restore the physiological constitution of PUFA in the cell membrane under certain conditions.

Biomarkers↗
PubMedDate not supplied

Control and impairment of immune privilege in the testis and in semen.

It has long been known that the testis is an immunologically privileged site in the body, and that human seminal plasma possesses a generalized immunosuppressive activity. Multiple factors participate in the establishment of immunotolerance in the testis: the blood-tubular barrier; the local production of immunosuppressive molecules by Sertoli cells; and the Fas system as regulator of immunological homeostasis in both physiological and pathological conditions. Cytokine-induced up-regulation of Fas as well as of integrin ligands, which are known to be specific binding molecules for lymphocytes on the Sertoli cell surface, indicates that the 'nursing' cells of seminiferous epithelium might be important in the impairment of immune privilege, causing autoimmune orchitis. In addition, the soluble form of Fas-ligand protein present in the seminal plasma of infertile patients might suggest a role for this immunomodulatory protein in male infertility. Finally, an understanding of the mechanisms underlying immune privilege in the testis and in semen might help to clarify how cells expressing 'non-self' antigens (such as male gametes) can escape the immune system in both the male and female genital tracts.

Female↗
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Antisperm immunity in natural and assisted reproduction.

Research conducted in the last 40 years has provided evidence that antisperm antibodies (ASA) can impair the fertilizing capacity of human spermatozoa. It is established that ASA can be present at different sites, can act against different antigens and can impair fertility in various ways. In fact, in the past it was amply demonstrated that ASA can act negatively on sperm motility and on cervical mucus penetration. In recent years, owing to the improvement and spreading of IVF techniques, it has been possible to demonstrate the effect of antibody-bound spermatozoa at the level of in-vitro gamete interaction. The literature demonstrates that the various previously used treatments for immunological infertility, i.e. medical therapy, intrauterine insemination with husband's spermatozoa (AIH) and IVF, usually had poor success. The primary choice of treatment in immunological infertility, especially in the most severe cases and when the sperm head is involved, is ICSI. ASA evaluation in all couples who undergo the various techniques of insemination or IVF is imperative.

Animals↗
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Cell-mediated antisperm immunity in selected forms of male infertility.

Leukocyte migration inhibition test (LMT) with semipurified spermatozoal antigen was carried out in two groups: normal males (fertile subjects before vasectomy; normal volunteers) and selected forms of male infertility. The percent positivity to the LMT in all the pathological groups considered, compared with controls positivity in only one out of 40 cases and only at the highest concentrations of Ag, stresses the important role played by cell-mediated antisperm immunity in male infertility. No characteristic seminal pattern was observed in the patients with positive LMT, probably on account of the particular selection of the patients studied. Finally, no significant correlation between humoral and cell-mediated antisperm immunity was observed, at least not in these selected series of patients.

Adult↗
PubMedDate not supplied

Immunoglobulins in human seminal plasma.

Single radial immunodiffusion has been used to evaluate immunoglobulins and secretory piece (SP) in human seminal plasma. Samples were collected from 90 healthy volunteers, 202 subjects submitted to vasectomy for contraceptive purposes, tested at various intervals after surgery, and 725 patients grouped according to selected andrological disorders. Results may be summarized as follows. In normal subjects IgG and IgA were constantly present (mean values +/- SD: 8.14 +/- 2.82 mg/dl; 1.91 +/- 1.03 mg/dl, respectively) while IgM were detected in trace amounts (from 0.7 to 3.3 mg/dl) in 10% of subjects, and negligible or absent in the remaining subjects. In vasectomized subjects IgG and IgA showed a significant increase only in the first 3 months after vasectomy, probably due to surgery. In andrological patients Ig showed an increase in cases with antisperm antibodies (A b) and in those with infections of genital tract and positive semen culture. On the basis of these findings and the secretory piece assay data the importance appears to be stressed of the local immunocompetent system at least in some andrological diseases.

Adult↗
PubMedDate not supplied

Vasectomy: study of circulating immune-complexes and its correlation with antisperm immunity in man, with a twelve-month follow-up study.

Circulating immune-complexes (CIC) have been detected in sera of vasectomized subjects using the Clq Binding Assay. Results seem to indicate that CIC are a feature of the early post-operative period and a consequence of acute immunization against sperm antigens. The progressive disappearance of CIC from the third month after vasectomy with the simultaneous increase in antisperm antibody percentage and titre suggests that CIC could be a temporary feature in vasectomized men and do not lead to a chronic disease, related to a Type III immune reaction.

Adult↗
PubMedDate not supplied

Radio-immuno binding test for anti-sperm antibody detection: analysis and critical revision of various methodological steps.

The authors report the results of a methodological study to optimize a radioimmunoassay to detect anti-sperm antibodies. They describe here the definitive methodology with all the data relating to the laboratory trials conducted at each step of the technique. Results seem to demonstrate that this radioimmunological method is sufficiently simple, specific, sensitive and reliable for use in a highly specialized laboratory of reproductive immunology. Furthermore, this type of analytical approach, whilst indicating once more the difficulty of the technical study of anti-sperm autoimmunity, confirms (with concrete data) the necessity of being extremely "prudent" in evaluating the results of this kind of anti-sperm antibody test.

Agglutination Tests↗
PubMedDate not supplied

Antisperm antibodies in young boys.

The authors report the results of antisperm antibody tests carried out on a group of 159 pre-pubertal boys suffering from various testicular pathologies. The data show that 21% of the patients' sera showed antibody activity against antigens on the sperm of healthy fertile donors. None of the control sera was ASA positive. Some differences were observed in pathology and age distribution of positivity.

Adolescent↗
PubMedDate not supplied

Lack of immunization after intraperitoneal insemination of spermatozoa.

Twenty infertile patients with normal tubal patency were inseminated intraperitoneally (11 once, seven twice, and two three times) with spermatozoa (mean 14 x 10(6), range 0.6-48 x 10(6)) prepared by the standard swim-up technique. The occurrence of immunization to spermatozoa was looked for by the Gelatin Agglutination Test (GAT) and Tray Agglutination Test (TAT). Both tests gave negative results for all the controls (10 pregnant and 10 puerperal women). Antisperm antibodies were measured in the serum before, 30 d and 4-7 months after Intraperitoneal Insemination (IPI). The last check was done for only 14 patients, since six became pregnant as a consequence of the first treatment. Of the 14 patients studied after 4-7 months, seven had two, and two had three IPI. In the group of inseminated patients, 18 women with no basal sperm antibody did not show evidence of antibody formation after the treatment and it was not increased after insemination in the two patients who already had low antibody titre (1/32). In conclusion, despite the large number of spermatozoa inseminated and even after several IPI attempts, there was no evidence of de novo production of or increase in already present anti-sperm antibodies according to the methods used for the detection of ASA in this study.

Adult↗
PubMedDate not supplied

Statistical analysis in andrology.

The authors began a statistical study on a file group of 9384 records of semen analyses and anamnestic data (P-1). From this file, they selected a group of 5191 patients having undergone analysis at least one time (P-2) and a file of 850 patients having undergone analysis at least three times (P-3). Finally a new group, derived from P-3, of 203 patients followed by their medical team was created (P-4). Two control groups-composed of 20 sperm-bank donors (DON) and 740 prevasectomy subjects (VAS)-were also created. Frequency distributions and cluster analyses were carried out. The multivariate statistical analysis allows a distinction to be made between fertile and infertile subjects regarding a patient's clinical condition. The most discriminating parameters appear to be sperm concentration and, above all, forward motility and sperm morphology.

Adolescent↗
PubMedDate not supplied

Glutathione therapy for male infertility.

Eleven infertile men were treated with glutathione (600 mg/day IM) for 2 months. The patients were suffering from dyspermia associated with various andrological pathologies. Standard semen and computer analyses of sperm motility were carried out before treatment and after 30 and 60 days of therapy. Glutathione exerted significant effect on sperm motility patterns. Glutathione appears to have a therapeutic effect on some andrological pathologies causing male infertility.

Autoantibodies↗
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Statistical andrology: standard semen analysis and computer-assisted sperm motility analysis.

Results are reported of a statistical evaluation of the variables obtained by standard microscopic semen analysis and by computer-assisted sperm motility analysis. Descriptive statistical analysis and cluster analysis were carried out on both sets of data. A contingency table was created to compare the classifications obtained by the two clustering procedures. A canonical correlation analysis was performed to evaluate the classification power of the variables obtained by the two semen analyses. The results show that the two techniques of semen analysis are complementary and not substitutive and that the correlated variables "percentage forward motility" and "sperm velocity" are the most discriminating.

Humans↗
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Computer assisted sperm motility analysis.

The CellSoft system was employed to study its reliability in the evaluation of seminal data in fertile and infertile subjects. In addition new motility data were introduced and added to the classic parameters. Various clinical and experimental applications are reported. The system is valid and extremely useful in seminal research. In order to obtain the above mentioned benefits it is necessary for the users to have extensive experience of seminology and computer technology.

Cryopreservation↗
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Therapy of immunologic infertility.

Infertility afflicts 10-15% of the couples and the incidence is progressively increasing. There are many possible causes for infertility, but immunological factors are among the most recently proposed causes. Once have ascertained that couple's infertility problem is due to sperm antibodies, the next obvious step is to attempt some form of therapy. In this paper we review the various classic and up-to-date methods of management of immunologic infertility.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Amniotic fluid test for the diagnosis of neural tube defects.

Alpha-fetoprotein and acetylcholinesterase were assayed in 374 amniotic fluids from normal pregnancies, at 9-15 weeks of gestation. We have investigated the correlations with the gestational age and have established our cutoff levels for these biochemical markers. We also report the values, that we have obtained in two cases of neural tube defects (NTD) and in several chromosomal aberrations. For early prenatal diagnosis of NTD, we wide to point out the importance of the contemporary determination of the two analytes and of the ultrasonographic investigation and biometry.

Acetylcholinesterase↗