Men born in the region of Leipzig (Saxony, Germany) between 1960 and 1970 showed a significantly decreased sperm count (examination of 3432 individuals)

The routine spermiogram parameters of 3432 patients born between 1952 and 1971 in the region of Leipzig were determined between January 1975 and March 2000. The patient group aged 24-35 years was characterized by low mobility and relocation living in the main centre of chemical industry with enormous environmental pollution in Eastern Germany up to 1990. Sperm concentrations and total sperm counts were found to be significantly reduced in men born between 1960 and 1970 compared with men born before this period (52.38 +/- 1.21 versus 70.79 +/- 2.15 millions ml(-1) 139.51 +/- 3.66 versus 176.31 +/- 6.04 millions; mean +/- SEM; P < 0.01; 2410 versus 1022 patients) independently of the year of semen examination.

Absence of Yq microdeletions in infertile men

Microdeletions of the long arm of the Y chromosome (Yq) were described in men with idiopathic azoo- or oligozoospermia and seem to cause impairment of spermatogenesis. Deletion frequencies differ considerably among selected infertile men. The aim of this study was to investigate the prevalence of Yq microdeletions in patients with idiopathic infertility. Men with azoospermia or oligozoospermia resulting from endocrine or obstructive causes or with a constitutional cytogenetic anomaly were excluded. Ninety-seven patients presenting at infertility centers in Leipzig and Zurich were included in the study. Sixty-four (66%) of them were severely oligozoospermic (sperm concentrations < 5 x 10(6)/mL) and 33 (36%) were azoospermic. A sequence-tagged site (STS) PCR strategy was applied for the microdeletion screening. Thirteen STS markers spanning the whole euchromatic region of Yq were used. No Y-chromosomal microdeletion could be detected in these 97 infertile men. This result suggests a much lower Yq deletion frequency than previously thought, even among strictly selected patients with idiopathic azoo- or oligozoospermia.

Flow cytometric analysis of enzymes in live spermatozoa before and after cryostorage

Synthetic fluorogenic substrates, like the CellProbe reagents, can determine enzymes in vital human spermatozoa. These substrates will enter the cells without previous cell permeabilization and exhibit fluorescence after cleavage depending on enzyme activity. They consist of different peptide sequences, specific for the enzymes, and a fluorescein- or rhodamine 110-dye moiety. The number of positive cells and the intensity of the fluorescence can be determined by flow cytometric analysis. We investigated several enzymes (peptidases, proteinases, esterases, elastases and collagenases) in intact spermatozoa before and after cryoprotection. Semen samples with normal spermiogram parameters were cryoprotected using the freezing medium TEST yolk buffer (TYB). Fresh spermatozoa showed a marked fluorescence after incubation with the synthetic substrates for the aminopeptidase M, butyryl esterase, fluorescein diacetate (FDA)-and FDA/sodium fluoride (NAF)-esterase, ala-ala-pro-val (AAPV)-elastase, gly pro-leu-gly pro-(GPLGP)-collagenase, gly gly leu-(GGL)-subtilisin as well as lys-ala-(LA)-dipeptidyl peptidase (DPP) II. After cryopreservation the spermatozoal fluorescence increased applying substrates for butyryl esterase (P<0.05), prolyl-aminopeptidase (P<0.001) and val-lys-(VK)-cathepsin (P<0.001) most probably due to elevated enzyme activities. The activities of FDA-esterase (P<0.05) and FDA/NAF-esterase (P<0.05), AAPV-elastase (P<0.01), GPLGP-collagenase (P<0.05) and GGL-subtilisin (P<0.001) decreased after cryopreservation. The substrates for arg-gly glut-ser-(RGES)-elastase, gly phenyl-gly ala-(GFGA)-collagenase and threo-pro-(TP)-cathepsin were not cleaved before as well as after cryostorage. The substrates for subtilisin an

Probability to retrieve testicular spermatozoa in azoospermic patients

AIM

The degree of probability to retrieve spermatozoa from testicular tissue for intracytoplasmic sperm injection into oocytes is of interest for counselling of infertility patients. We investigated the relation of sperm retrieval to clinical data and histological pattern in testicular biopsies from azoospermic patients.

METHODS

In 264 testicular biopsies from 142 azoospermic patients, the testicular tissue was shredded to separate the spermatozoa, histological semi-thin sections of which were then evaluated using Johnsen score.

RESULTS

The retrieval of spermatozoa correlated significantly ( P < 0.001) with the testicular volume ( r = 0.49), the FSH concentration ( r = -0.66), the maximum score (r = 0.85) and the mean Johnsen score (r = 0.81). In the multivariate regression analysis the successful testicular sperm extraction showed the closest relationship to the maximum score. The testicular volume correlated significantly with the mean Johnsen score ( r = 0. 64, P < 0. 001), and the basal serum FSH concentration mainly with the maximum score ( r = - 0.77; P < 0.001). Patients with a history cryptorchidism showed a significantly lower Johnsen score compared to the patients who did not have any testicular disease in the past (3.7 +/- 2.4 vs. 5.9 +/- 2.5; P < 0. 01).

CONCLUSION

In a limited range, the testicular volume and the FSH concentration in serum were related to the Johnsen score which correlated significantly with the sperm retrieval. The successful sperm retrieval can be expected in all azoospermic patients irrespective of the results of clinical examination. However, the probability of retrieval of spermatozoa decreased significantly in patients with a FSH level > 18 U/L, testicular volume < 5 mL, mean Johnsen score <5, and maximum Johnsen score <7.

Lipid analysis of human spermatozoa and seminal plasma by MALDI-TOF mass spectrometry and NMR spectroscopy - effects of freezing and thawing

In the present study, the applicability of proton NMR spectroscopy and matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) to the analysis of the lipid composition of human spermatozoa and seminal fluids as well as changes after cryopreservation of human spermatozoa was investigated. Whereas NMR spectra primarily indicated a high content of double bonds within the spermatozoa but no marked differences upon cryopreservation, MS detected intense peaks which could be assigned to phosphatidylcholines containing one docosahexaenoic and one palmitic or stearic acid residue (m/z=806 and 834). In contrast, the seminal plasma contained more saturated fatty acids and especially more sphingomyelin (SM). A freezing/thawing cycle markedly influences the lipid composition of spermatozoa. There was a diminution of phosphatidylcholines (16:0, 22:6 and 18:0, 22:6) and SM (16:0) and the appearance of lysophosphatidylcholines (16:0 and 18:0) and ceramide (16:0). These data demonstrate the release or activation of both phospholipase A(2) and sphingomyelinase in human spermatozoa due to the freezing/thawing cycle. These results were finally confirmed by experiments on the action of phospholipases on lipids containing docosahexaenoic acid.

Hidden effects of cryopreservation on quality of human spermatozoa

The effects of cryopreservation on two characteristics of human spermatozoa were investigated: the early phases of disturbed plasma membrane function and the activity of enzymes in intact spermatozoa. The membrane function was detected by means of the calcium-dependent binding of fluorescein isothiocyanate (FITC)-conjugated Annexin V to sperm plasma membranes. Annexin V monitors the translocation of phosphatidylserine from the inner to the outer leaflet of the plasma membrane, which is one of the earliest features of membrane disintegration. For the second aim synthetic fluorogenic substrates for peptidases, proteinases, esterases, elastases and collagenases were applied. These substrates, CellProbe trade mark reagents consist of different peptide sequences, specific for the enzymes, and a fluorescein- or rhodamine 110-dye moiety. They enter the cells without previous membrane permeabilisation and exhibit fluorescence after cleavage depending on enzyme activity. The number of positive cells and the intensity of the fluorescence were determined by flow cytometric analysis comparing fresh spermatozoa with cryopreserved ones. Thirty-five semen samples collected from 35 donors were cryopreserved using the freezing medium TEST yolk buffer. All specimens showed normal spermiogram parameters. Twenty-five of the samples were used for detection of Annexin V-FITC binding and 10 semen samples for investigations of the intracellular enzymes. The Annexin V-assay applied two fluorescent dyes (Annexin V, AN and propidium iodide, PI) which led to three groups of spermatozoa (a) viable spermatozoa (AN V-negative and PI-negative), (b) dead spermatozoa (AN V-positive and PI-positive) and (c) cells with impaired but integer plasma membrane (AN V-positive and PI-negative). The percentage of vital Annexin V-negative spermatozoa (x +/- SEM) decreased significantly (p < 0.001) from fresh spermatozoa (51.6 +/- 3.1) to cryopreserved spermatozoa (26.6 +/- 2.2%) and was associated with their motility (57.9 +/- 1.9% motile fresh spermatozoa vs. 22.6 +/- 3.9% motile sperm after cryopreservation). Of the spermatozoa 28.2% were Annexin V-positive before and 44.4% after cryostorage even though they did not bind to PI. Thus, vital spermatozoa showed a disturbed membrane function indicating viability before as well as after cryostorage. Moreover, after cryopreservation the spermatozoal fluorescence increased applying substrates for butyryl esterase (p < 0.05), prolyl-aminopeptidase (p < 0.001) and val-lys-(VK)-cathepsin (p < 0.001). In contrast, the activities of fluorescein diacetate (FDA)- and FDA/sodium fluoride (NAF)-esterase (p < 0.05), ala-ala-pro-val-(AAPV)-elastase (p < 0.001), gly-pro-leu-gly-pro-(GPLGP)-collagenase (p < 0.05) and gly-gly-leu-(GGL)-subtilisin (p < 0.001) decreased after cryopreservation. The substrates for arg-gly-glut-ser-(RGES)-elastase, gly-phenyl-gly-ala-(GFGA)-collagenase and threo-pro-(TP)-cathepsin were not cleaved before as well as after cryostorage. In addition to the known effects of sperm cryopreservation our results showed two further alterations of human ejaculated spermatozoa: (a) disturbed plasma membrane function, which is not detectable by supravital staining and (b) a changed pattern of intracellular enzyme activities.

Binding of annexin V to plasma membranes of human spermatozoa: a rapid assay for detection of membrane changes after cryostorage

When the cell membrane is disturbed, phospholipid phosphatidylserine (PS) is translocated from the inner to the outer leaflet of the plasma membrane. This is one of the earliest signs of apoptosis and can be monitored by the calcium-dependent binding of annexin V. Therefore, annexin V-binding, in conjunction with flow cytometry, was used to evaluate the integrity of the sperm plasma membrane after different cryostorage protocols: i.e. 10% (v/v) glycerol; sperm maintenance medium (MM); freezing medium TEST yolk buffer (TYB); or cryostorage without protection (cryoshock). Using a combination of two fluorescent dyes, annexin V and propidium iodide (PI), led to three groups of spermatozoa being identified: (i) viable spermatozoa (annexin V-negative and PI-negative); (ii) dead spermatozoa (annexin V-positive and PI-positive); and (iii) cells with impaired but integer plasma membrane (annexin V-positive and PI-negative). The percentage of vital annexin V-negative spermatozoa increased significantly (P < 0.05) from spermatozoa treated by cryoshock (15.0+/-1.2%) to spermatozoa cryopreserved by TYB (26.6+/-2.2%) via cryopreservation by 10% (v/v) glycerol (19.9+/-1.6%) and by MM (22.2 1.8%) and was associated with the percentage of motile spermatozoa (17.6+/-3.4% by glycerol; 19.6+/-3.7% by MM and 22.6+/-3.9% by TYB; P = 0.0001). Of the spermatozoa, 12-22% were annexin V-positive even though they did not bind to PI, indicating viability before as well as after cryostorage. The percentage of vital annexin V-positive spermatozoa was significantly correlated with different sperm motility parameters (velocity straight linear, r = 0.601, P = 0.018; percentage of linearly motile spermatozoa: r = 0.549, P = 0.034). We, therefore, concluded that annexin V-binding is more sensitive in detecting a deterioration of membrane functions than PI staining, and that a considerable percentage of spermatozoa might have dysfunctional plasma membranes besides dead or moribund cells. Of the cryopreservation protocols tested, TYB yielded the most viable spermatozoa. Therefore, we advocate the use of the annexin V-binding assay for the evaluation of the quality and integrity of spermatozoa.

Localisation of enzymes in live spermatozoa by CellProbe reagents (preliminary results)

As a new approach, various synthetic fluorogenic substrates, the CellProbe reagents, were applied to examine the topography of their cleavage in vital human spermatozoa. These substrates are able to enter the cells without requiring previous cell permeabilization and can produce a fluorescent dye after cleavage, depending on enzyme activity. Vital spermatozoa from samples with normal spermiogram parameters showed fluorescence in different areas and intensity after incubation with a variety of substrates for aminopeptidase A, peroxides, subtilisin, dipeptidylpeptidase IV (DPP IV), cathepsin D, glucosidase and glucuronidase, but not with the substrate for galactosidase. Fluorescence was mainly located in the acrosomal cap (substrates for DPP IV, subtilisin, cathepsin D, glucosidase and glucuronidase) in the middle piece and head (substrates for peroxides, glucosidase), in the sperm head (substrates for aminopeptidase A) and occasionally in the tail (substrate for glucosidase). The substrate for subtilisin may play a role in andrology, because subtilisin is a serine protease like acrosin. This substrate may possibly be used to determine the acrosin activity in vital spermatozoa. The CellProbe reagents for fluorescence cytoenzymology may serve advanced methods in both clinical andrology and spermiological research, presuming that the characteristics and qualities of the synthetic substrates are correct. Therefore, more extended studies will be necessary to determine their clinical utility and significance under physiological and pathological conditions.

[Disorders of ejaculation]

Ejaculatory disorders include premature ejaculation (p. e.), deficient ejaculation (d. e.) and retrograde ejaculation (r. e.). On the basis of the history and simple investigations, the various disorders are relatively easy to differentiate. History taking should include information about the ability to ejaculate, including nocturnal emission and the ability to experience orgasm. Investigations mainly include the demonstration of sperm in the postmasturbation urine, analysis of the ejaculate, determination of the secretion markers of the adnexa and ultrasonographic examination of the genital organs. The treatment of choice in premature ejaculation is sexual therapeutic behavioral training, where necessary in combination with medication to delay ejaculation, e. g. diazepam or chlorodizepoxid. In the absence of underlying organic disease deficient ejaculation is treated with behavioral therapy or vibrator stimulation of the glans. Postoperative or post-traumatic disorders, however, often require transrectal electrojaculatory stimulation or sperm aspiration from vas deferens. There are three principles of management of retrograde ejaculation: 1. conversion of retrograde into antegrade ejaculation by drug therapy, 2. harvesting of sperm from postorgasm urine and 3. surgical treatment. Our own observations have shown that drug treatment of ejaculatory dysfunction is ineffective in patients with anorgasm or when postmasturbation urine contained no spermatozoa. Currently male infertility due to ejaculatory problems can be effectively treated, where necessary in combination with the new methods of assisted fertilisation, for which purpose, however, accurate identification of the ejaculation disorder presenting is required.

Prostate-specific antigen triggers transformation of seminal alpha2-macroglobulin (alpha2-M) and its binding to alpha2-macroglobulin receptor/low-density lipoprotein receptor-related protein (alpha2-M-R/LRP) on human spermatozoa

BACKGROUND

The aim of this study was to identify the proteolytic activity which triggers the transformation of human alpha2-macroglobulin (alpha2-M) in seminal fluid and its binding to its receptor.

METHODS

Measurement of the concentrations of total and transformed alpha2-M in seminal fluid was accomplished by ELISA. Zymography of seminal plasma was performed in SDS-polyacrylamide gels containing casein as proteolytic substrate. Rate electrophoresis, SDS-PAGE, and Western blotting were applied to study the complex formation of prostate-specific antigen (PSA) with alpha-M. Ligand-binding analysis of sperm cells was performed using [125I] labeled proteins. Detection of receptor on sperm cells was achieved by immunofluorescence.

RESULTS

The mean concentration of total alpha2-M in a random collection of seminal plasma was 4.6 microg/ml. On average, between 33-98% of the inhibitor was found to be transformed. Zymography of seminal plasma revealed a proteolytic activity which is associated with a 33-kDa protein identified as PSA. Its proteolytic activity could be inhibited by 0.2-M. Both purified PSA and seminal plasma were capable of transforming native alpha2-M. Binding of PSA to alpha2-M triggers the exposition of receptor binding sites in the inhibitor molecule, which causes binding of the complex to alpha2-M-R/LRP identified on spermatozoa.

CONCLUSIONS

PSA, the main proteinase in seminal fluid, is responsible for the transformation of alpha2-M and for its binding to alpha2-M-R/LRP present on spermatozoa. The binding of alpha2-M-PSA complexes to the spermatozoa receptor may exert an impact on normal sperm-cell functions.

Adhesion molecules and matrix proteins on human spermatozoa

Ejaculated spermatozoa and spermatogenic cells express alpha- and beta-chains of beta 1, 3 and 4 integrins as well as their ligands fibronectin and laminin in an extended intra- and interindividual variation and in different patterns of location. The mRNA transcripts of these molecules were detectable by nested polymerase chain reaction in the spermatozoa. The conclusion of a functional competence of these adhesion molecules (AM) was supported by their relation to the results of the zona-free hamster oocyte penetration (HOP) test, the in vitro fertilization of human oocytes and cell attachment assays. AM labelling was influenced by the disintegration of the sperm plasma membrane, especially in seminal plasma, by progesterone, human follicular fluid and microorganisms, but was barely modified by sperm cryopreservation. Despite substantial advances in the knowledge about sperm adhesion molecules, many questions remain to be answered.

Localization of adhesion molecules on human spermatozoa by fluorescence microscopy

The expression of adhesion molecules on human spermatozoa of healthy probands was analysed. The localization patterns of adhesion molecules (AM) on the spermatozoal surface were documented by fluorescence microscopy. Spermatozoa were incubated with antibodies against alpha 1 (CD49a), alpha 2 (CD49b), alpha 3 (CD49c), alpha 4 (CD49d), alpha 5 (CD49e), alpha 6 (CD49f) chains of beta 1 integrins, beta 1 (CD29), beta 2 (CD18), alpha V (CD51), beta 3 (CD61) and beta 4 integrin chains, the LFA-3 (Lymphocyte function antigen, CD58) from the immunoglobulin superfamily and the extra-cellular matrix proteins laminin, fibronectin and collagen IV. For collagen IV, alpha 1 and alpha 2 chains no expression could be noticed. Laminin was detected at the acrosomal membrane, fibronectin and beta 4 chain mainly at the equatorial membrane. The fibronectin receptors alpha 3, alpha 4 and alpha 5 chains of the beta 1 integrins were mainly located on acrosomal and equatorial membrane areas. Laminin receptor alpha 6 chain was located postacrosomal and less frequently acrosomal. beta 2 chain and vitronectin receptors alpha V and beta 3 chains had a mainly postacrosomal localization pattern. LFA-3 was found constantly on postacrosomal membrane areas. Double staining technique was used to prove the simultaneous occurrence of fibronectin and its integrin receptors alpha 3, alpha 4 and alpha 5 chains and of alpha V and beta 2 chains on spermatozoa. The localization patterns of integrins on double stained spermatozoa were similar to the patterns described for single stained spermatozoa. The localization of fibronectin appeared to be influenced by the presence of integrins: the typical equatorial fibronectin band disappeared in case of an equatorial localization of integrins.

Effects of pure human follicle-stimulating hormone (pFSH) on sperm quality correlate with the hypophyseal response to gonadotrophin-releasing hormone (GnRH)

In 41 men with idiopathic infertility, the effect of pure follicle-stimulating hormone (pFSH) therapy on semen parameters was evaluated in relation to the results of the gonadotrophin-releasing hormone (GnRH) stimulation test in an open study. The patients showed a mean (+/-standard error) sperm concentration of 15.84 (+/-2.87) Mill. ml-1, 41.02 (+/-4.19)% of the spermatozoa were motile and 46.16 (+/-2.36)% normomorph before treatment. All patients were administered 150 IU pFSH subcutaneously three times weekly for 10 weeks. After therapy with pFSH, no significant differences compared with the pre-treatment sperm characteristics were observed (P > 0.05) except for the velocity average path, VAP (P = 0.029). However, the stimulation factors of FSH in the GnRH test showed a significantly negative correlation with the pFSH mediated improvement of sperm concentration (r = -0.662, P = 0.000002), of percentage of normomorph spermatozoa (r = -0.480, P = 0.0015) and total count of motile spermatozoa per ejaculate (r = -0.567, P = 0.00014). In consequence, the patients were divided into two groups depending on the stimulation factor of hypophyseal FSH secretion, FSH-SF. The cut-off point of the FSH-SF was set at 1.7 because the correlation analyses detected a 1.5-fold improvement of sperm parameters at this hypophyseal response on average. Pure FSH treatment increased the concentration of spermatozoa (P = 0.0007), the total count of motile spermatozoa in the ejaculate (P = 0.015) as well as the computer-aided sperm motion parameters VAP (P = 0.029) and velocity curve linear, VCL (P = 0.049) in patients with FSH-SF < 1.7, whereas in the patient group with FSH-SF > 1.7 no improvement of semen parameters was found. Insufficient stimulation of hypophyseal FSH secretion may be a prerequisite but not a guarantee for responsiveness to pFSH treatment. The results of the present investigation suggest that FSH stimulation in the GnRH test should be taken into account in idiopathic infertile men before pFSH therapy.

Insulin-like growth factor-I and alpha 2-macroglobulin in seminal plasma correlate with semen quality

Insulin-like growth factor-I (IGF-I) and alpha 2-macroglobulin (alpha 2-M) are believed to be involved in the development of germ cells. IGF-I is mainly controlled by concentrations of human growth hormone (HGH), influences cell proliferation and differentiation and its action is mediated by insulin-like growth factor-binding proteins (IGFBP), placental protein 14 (PP14) and prostate-specific antigen (PSA). alpha 2-M acts as a broad spectrum proteinase inhibitor and a binding protein for many cytokines and hormones, e.g. inhibin and activin. This study was designed to identify concentrations of these molecules in seminal plasma in normal semen samples of healthy men, correlations with semen quality, the relationship of IGF-I and alpha 2-M with factors affecting male fertility, and whether vasectomy influences the concentrations of these molecules. Concentrations of IGF-I and alpha 2-M in human seminal plasma were related to semen quality, basal concentrations of HGH, testosterone, IGFBP-3, soluble fibronectin receptor (sFNR), PSA and PP14 in seminal plasma and to serum concentrations of luteinizing hormone (LH) and follicle stimulating hormone (FSH). Commercially available assays were used to analyse 69 semen samples of various quality and 11 post-vasectomy samples. IGF-I concentrations in seminal plasma were significantly correlated with the percentage of morphologically normal spermatozoa (r = 0.748, P = 0.00001) and sperm concentration (r = 0.301, P = 0.011), but negatively correlated with serum FSH (r = -0.506, P = 0.00006) and PSA in seminal plasma (r = -0.388, P = 0.00009). Total alpha 2-M was significantly correlated with sperm count (r = 0.423, P = 0.0005), percentage of progressively motile spermatozoa (r = 0.444, P = 0.00019), quality of motility (sperm motile efficiency, r = 802, P = 0.00001) and straight line velocity (r = 0.411, P = 0.0013). Correlation between the sperm concentration and HGH in seminal plasma was weak (r = 0.287, P = 0.015). Vasectomy reduced the concentration of total alpha 2-M (P = 0.00008) and HGH (P = 0.0068) in the seminal plasma; IGF-I was also reduced after vasectomy when the total ejaculate amount was considered. Thus IGF-I and alpha 2-M are significant for the germ cell development: IGF-I in the maturation of spermatozoa and alpha 2-M in progressive motility.

[Modern fertilization techniques]

In Germany, some 17.2% of married couples are unintentionally childless. Of these, about one-third have a male factor infertility (with disordered spermatogenesis), which in part is unresponsive to drug treatment. In such cases, assisted reproductive techniques are giving childless couples new hope. The techniques are based on two principles: 1) in vitro improvement in semen quality in the laboratory, and 2) the overcoming of natural barriers to fertilization. The latter includes intra-uterine insemination (IUT), in vitro fertilization and embryo transfer (IVF/ET), gamete intrafallopian transfer (GIFT), subzonal sperm insemination (SUZI), zona pellucida drilling, and intracytoplasmatic injection of sperm (ICSI). ICSI has also used epididymal spermatozoa obtained by microsurgical aspiration (MESA) and sperm extracted from testicular biopsies (TESA). These methods have their own specific indications, contraindications and pregnancy rates. However, assisted conception techniques should not be considered outside the overall situation of the couple, including ethical, sociological, physiological and general medical problems.

Detection of mRNA transcripts of beta 1 integrins in ejaculated human spermatozoa by nested reverse transcription-polymerase chain reaction

Matrix proteins (e.g. fibronectin, laminin and vitronectin) and their receptors, especially beta 1 integrins, may play a role in sperm-oocyte interactions. These proteins are well described on spermatogenic cells but especially in ejaculated spermatozoa, the presence of mRNA as a necessity for their synthesis is not clear. Therefore the mRNA synthesis of the beta 1, alpha 3, alpha 4, alpha 5 and alpha 6 chains (fibronectin and laminin receptors) of the beta 1 integrins was investigated by nested reverse transcription-polymerase chain reaction (RT-PCR) in spermatozoa of human semen samples (n = 18) which showed normal classical semen parameters after swim-up preparation. After the second amplification, we obtained specific signals for mRNA transcripts of the beta 1, alpha 3, alpha 4 and alpha 6 chains in 17 of 18 semen samples investigated. All control PCRs were negative for somatic cell transcripts and contamination by somatic cells was excluded. These results demonstrate for the first time that human ejaculated spermatozoa contain the mRNA transcripts of beta 1 integrins and support the role of these proteins in adhesive mechanisms in the fertilization process.

[Dermatologic symptoms of parvovirus B19 infections]

Infections with parvovirus B19 are often characterized by the well-known erythema infectiosum, usually accompanied by fever and arthralgia. Furthermore the virus may cause a lethal hydrops fetalis during the pregnancy or a severe aplastic crisis in patients suffer from chronic hemolytic anemia. We present three patients infected by parvovirus B19. Whose skin lesions included a non-specific exanthem, erythema multiforme, and purpura. The virus infection was confirmed both by serology and PCR identification. In conclusion the diagnosis of acute exanthems should include the search for virus infections.

In vitro fertilization: increased VLA (very late antigen) integrins and fibronectin after acrosome reaction

The pattern of detectable adhesion molecules (AM) on human ejaculated spermatozoa used for in vitro fertilization (IVF) of human oocytes was evaluated. The percentage of spermatozoa with the alpha chains 3, 4, 5, and 6 of the integrins (also called very late antigens, VLA alpha 3, 4, 5, 6), the alpha V and the beta 3 chains, as well as the matrix proteins laminin and fibronectin, were determined by flow cytometry using monoclonal antibodies against integrins and matrix proteins before and after the acrosome reaction. This reaction was induced by the low-temperature method according to P. Sanchez, E. Töpfer-Petersen, R. J. Aitken, and W. B. Schill (1991, Andrologia 23:197-203) and monitored by the binding of FITC-conjugated Pisum sativum agglutinin. Twenty-three of 34 investigated semen samples fertilized at least one oocyte (fertile group) and 11 samples did not induce a pronucleus formation or cleavage of an oocyte (infertile group). Significant differences in the classical semen parameters between both semen sample groups could be shown only for the percentage of progressively motile spermatozoa (p = .046, U test). The spermatozoa of the fertile group showed a significantly higher expression of VLA alpha 3 (p = .045) and fibronectin (p = .048). Additionally, after the loss of the acrosome a significantly higher expression of alpha 4, alpha 5, and alpha 6 chains of integrins (p < .05) was detected in the fertile semen group. In contrast, the inducibility of the acrosome reaction differed only to a nonsignificant extent (p = .094). These data suggest that spermatozoa showing a higher expression of the alpha chains of the integrins after the acrosome reaction have a better fertilization rate in vitro.

Low expression of adhesion molecules and matrix proteins in patients showing poor penetration in zona-free hamster oocytes

The expression of adhesion molecules and matrix proteins by human spermatozoa as well as their binding to and penetration of zona-free hamster eggs were investigated in 17 patients by means of flow cytometry. Both binding and penetration of hamster oocytes and expression of alpha- and beta-chains of beta 1, beta 3 and beta 4 integrins were determined before and after induction of the acrosome reaction. The expression of the integrin ligands, fibronectin and laminin were also analysed. Significant differences in the expression of very late antigen (VLA) integrins, VLA alpha 4-chain (CD49d), the classical fibronectin receptor VLA alpha 5-chain (CD49e), leukocyte function-associated molecule-3 (LFA-3; CD58) and fibronectin were observed between patients showing good (> 10%) or poor (< 10%) penetration in the sperm penetration assay (P = 0.0068). It is concluded that these adhesion molecules are intimately involved in the sperm-oolemma interaction. Since no differences were observed in either spermiogram parameters or the percentages of acrosome-reacted spermatozoa in the two groups, sperm-oolemma binding and penetration should be regarded as discrete parameters of sperm function.

Disintegration of human spermatozoal membranes in seminal plasma decreases the binding capacity of integrins

The in vitro binding capacity of spermatozoal integrins to matrix components after disintegration of sperm membranes was evaluated. The percentage of spermatozoa with functionally-relevant integrins was determined before and after devitalization of spermatozoa, which were resuspended in seminal plasma or in culture medium. The devitalization was performed by cryoshock or by incubation of spermatozoa with triton X-100 in a concentration ranging from 0.01 to 1.0%. The spermatozoal integrins were detected by the binding of anti-integrin antibodies and flow cytometry and the functional activity was monitored by the binding of the spermatozoa to the matrix components in a cell attachment assay. The seminal plasma decreased the binding of anti-integrin antibodies to the spermatozoal surface and the binding of spermatozoa to ligands and matrix components. respectively. In contrast, the expression of fibronectin and laminin on spermatozoa was increased. Not all spermatozoa, which expressed integrins on their surface bound to the ligands in the cell attachment assay. These results suggest that the detectable integrins only partially exert functional relevance. It can be concluded that the spermatozoa with fragile plasma membranes are more prone to functional inactivation of their integrins by the seminal plasma.

Evidence of beta 1 integrins and fibronectin on spermatogenic cells in human testis

Interactions between human spermatozoa and oocytes are an essential event in the process of fertilization. Cell-cell and cell-matrix interactions in somatic cells are mediated by adhesion molecules such as beta 1 integrins (very late antigens; VLA). Therefore, we investigated the expression of beta 1 integrins and the matrix proteins collagen IV, fibronectin and laminin in human testis by immunohistology. Monoclonal antibodies against the beta chain of beta 1 integrins reacted with the basement membrane of the tubuli seminiferi, spermatocytes, spermatids and testicular spermatozoa. The alpha 3, -5 and -6 chains of beta 1 integrins showed the same pattern, whereas, the alpha 1, -2 and -4 chains could not be detected on spermatogenic cells. These VLA subunits were localized on endothelial cells, leukocytes and basement membranes. Matrix proteins such as laminin, collagen IV and fibronectin were detectable as components of basement membranes in human testis. Germinal cells except spermatogonia expressed fibronectin only. These results demonstrate that beta 1 integrins and matrix proteins in human testis are normally expressed on somatic tissue and that germinal cells, especially spermatocytes, spermatids and spermatozoa show positive reactions with antibodies against the VLA-3, -5 and -6 complexes and fibronectin. These findings suggest a production of beta 1 integrins and fibronectin during the spermatogenesis and a role of these proteins in adhesive mechanisms of spermatozoa similar to somatic cell-cell or cell-matrix interactions.

Beta 1-integrins of spermatozoa: a flow cytophotometric analysis

The expression of adhesion molecules on human ejaculated spermatozoa was investigated by means of flow cytophotometry using monoclonal antibodies against eight different adhesion molecules. Spermatozoa from infertility patients who exhibited normal semen parameters showed specific fluorescence after incubation with antibodies against very late antigens VLA alpha 4, VLA alpha 5, VLA alpha 6, and corresponding matrix proteins laminin and fibronectin. Semen samples from men with teratozoospermia or oligoasthenoteratozoospermia were characterized by reduced expression of adhesion molecules. Normal and pathological semen samples differed mostly in the expression of VLA alpha 5. After artificial induction of the acrosome reaction by a cold shock method and incubation with 2 mM Ca2+, a changed pattern of adhesion molecules on the sperm surface was found for VLA alpha 6 as the most prominent molecule. After treatment of spermatozoa with 0.1% Triton X-100, the number of cells with adhesion molecules increased significantly. This result suggests that adhesion molecules are an integral part of sperm structure.

Lack of HLA-molecules on human spermatozoa and in seminal plasma

The expression of human leukocyte antigens (HLA) on ejaculated spermatozoa and on lymphocytes was compared by flow cytometry using monoclonal antibodies towards HLA class I (pan-HLA-A, -B, -C) and class II (DR) antigens. Soluble antigens of HLA class I (s HLA-A, -B, -C) in seminal plasma and in blood plasma were monitored with an ELISA technique. Lymphocytes showed specific fluorescence after incubation with the antibodies against HLA class I and class II (DR), whereas, on spermatozoa no positive immunofluorescence could be detected. No antibodies were bound to any significant extent either after modifications of sperm preparation (density gradient centrifugation, swim up-technique, addition of azide, foetal calf serum or benzamidine chloride) or after treatment of spermatozoa with detergents. Furthermore, different concentrations of soluble HLA-A, -B, -C in seminal plasma and in blood plasma were detected. The latter one showed soluble HLA about four-fold more concentrated than the seminal plasma (means +/- SD: 262.5 +/- 144.4 nmol l-1 vs. 62.5 +/- 27.1 nmol l-1). These results suggest, that the HLA-expression differs between human spermatozoa and somatic cells.

Acrosome reaction changes the pattern of cyclic nucleotide phosphodiesterases in human sperm

Three categories of cyclic nucleotide phosphodiesterases (cNPDE) are distinguished at present: type 1 with high affinity to cyclic GMP; type 2 with low affinity to cyclic AMP and to cyclic GMP; and type 3 with high affinity to cyclic AMP. For the evaluation of normal values in human spermatozoa 50 semen samples with normal classical semen parameters were investigated. The activities (means +/- SD) of the cNPDE types (10(-11) mol/10 min x 10(8) spermatozoa) of washed human spermatozoa amounted to 47 +/- 22 (type 1), 3350 +/- 1537 (type 2), and 70 +/- 38 (type 3). A significant inhibition of type 3 by cyclic GMP could not be detected. One milligram protein of the spermatozoa hydrolyzed about 20-fold the amount of cyclic nucleotides compared with 1 mg protein of the seminal plasma. Furthermore, the cNPDE of the spermatozoa and of the seminal plasma differed in the influence of type 3 by cyclic GMP and in the pattern of activities. The acrosome reaction (AR) induced by the cold shock method led to an activation of type 2 and 3 unlike the initiation of the AR by the digitonin method. The latter did not cause significant differences of the cNPDE activities before and after the AR.

Selected sperm differ from nonselected cells in their electrophoretic mobility (EPM) after demembranation

Human semen samples were first treated by swim-up migration or by Percoll density gradient centrifugation for selection of spermatozoa. The net surface charges of spermatozoa in the resulting compartments were indirectly evaluated by the electrophoretic mobility (EPM) during spermatozoal microelectrophoresis. Significantly different electrophoretic mobilities were measured between the compartments after demembranation with 0.1% (v/v) Triton X-100. However, without intermediate treatment by the detergent no significant differences were detected between the spermatozoal EPM. In addition, spermatozoa were divided into migrated and nonmigrated spermatozoal populations by the swim-up technique, and then treated with urea to remove spermatozoal coats. No significant differences in EPM were detected between these two groups. This investigation demonstrates that selected spermatozoa from semen exhibit an additional dimension of superiority, in EPM, to nonselected spermatozoa, which may better equip them for the process of fertilization. Measurements of EPM, therefore, may provide yet another, perhaps valid, means of developing a clinical tool for evaluating the potential fertilizing capacity of a semen sample in infertility studies.

Influence of cryopreservation on the microelectrophoretic motility (EPM) of human spermatozoa

The net surface charge of spermatozoa represents a characteristic of the plasmamembrane. It can be evaluated indirectly, by the measurement of the sperm electrophoretic motility (EPM). The EPM of washed human spermatozoa was determined in the microelectrophoresis to investigate three problems: (a) intra- and interindividual variation coefficients of EPM of cryopreserved spermatozoa, (b) effects of cryopreservation medium, temperature shock and cryoprotection on the EPM, (c) relationship between the EPM and the cryotolerance of the spermatozoa. The inter- and intrain-dividual variation coefficients of the sperm EPM of 24 cryopreserved semen samples of 6 fertile semen donors amounted to 7% and to 6%, respectively. The cryopreservation did not cause a significant change of sperm EPM in contrast to the temperature shock in liquid nitrogen. Temporary incubation of spermatozoa with egg yolk decreased their EPM. A significant correlation between EPM and the cryotolerance ascertained by the alteration of sperm motile efficiency could be found. After contact with egg yolk spermatozoa achieved a behaviour that corresponded to a better cryotolerance.

Electrophoretic patterns of spermatozoal nucleoproteins (NP) in fertile men and infertility patients and comparison with NP of somatic cells

During spermatogenesis in mammals the evolutionary early histones are replaced step by step by more species specific nucleoproteins (protamines). The protamines protect the genetic information of the male against mutagenic or other damaging influences and possibly play a role in male fertility. A method was presented to study the nucleoproteins (NP) of single human ejaculates. This procedure was checked concerning its usability and validity by bull spermatozoa. The NP of cryopreserved human spermatozoa of fertile men and of infertility patients were investigated and compared with the electrophoretic patterns of NP of somatic hepatocytes of rat and mouse. A total of 48 semen samples were studied. Ten of these samples were obtained from semen donors of proven fertility and 38 samples were collected from male partners of infertile couples. Photodensitometrically it could be distinguished between percentages of non-protamines (PNP) and percentages of protamines (PP). The PP varied intra-individually with a mean standard deviation of 34%, analogously to the alterations of classical semen parameters. The PP of fertile men did not significantly differ from the infertility patients with normal spermiogram parameters but showed a significantly higher value compared with the semen samples with pathological spermiograms. On average the PP of all infertile patients were significantly lower than the PP of fertile semen donors.

[Fertility assessment based on sperm examination]

Male fertility is indirectly evaluated by analysis of semen. Two questions must be answered in connection with an investigation program. 1. Which prerequisites must the spermatozoa fulfill to the fertilization of oocytes in vivo and to the induction of a normal embryogenesis? 2. Which laboratory tests can be taken as an in vitro model for the fertilization process? Fertilization consists of various steps which require different spermatozoal functions. Several methods were developed to test in vitro whether the semen sample is capable to realize the sequence of fertilization, whereas, it is supposed that there is a close connection between the laboratory test in vitro and the fertilization in vivo. The methods of sperm analysis are presented and their medical practice and predictive value is discussed.

[Expression of leukocyte antigens in human sperm]

The expression of leukocyte antigens on human ejaculated spermatozoa and lymphocytes was compared by means of the immunofluorescence technique and monoclonal antibodies against anti-HLA class I (pan-HLA-A,B,C) and class II (DR, DR/DP). Lymphocytes showed specific fluorescence phenomena after incubation with the antibodies. However, in the case of spermatozoa no immunofluorescent labeling was detected. Modifications of the method of sperm preparation (Ficoll centrifugation, swim-up technique, addition of azide, fetal calf serum or benzamidinchloride) did not lead to different results. We were not able to find HLA-antigen expression on fresh human spermatozoa using immunofluorescence.

Sperm motile efficiency (SME) of fresh spermatozoa in a hypotonic medium correlates with their cryosurvival in fertile men and infertility patients (predicting test)

The sperm motile efficiency (SME) of fresh spermatozoa in a hypotonic medium was investigated concerning the prediction of post thaw motility and the differentiation between fertile men and infertility patients. A total of 95 semen samples were collected for this study. Twenty of these samples were obtained from semen donors of proven fertility and 75 samples were collected from male partners of infertile couples. There were no significant differences between the SME after mixture of the fresh semen with a 140 mOsm saline in equivalent volumes and after cryopreservation (Wilcoxon-matched pairs signed ranks-test) but a significant positive correlation between the SME after both treatments of semen samples was notable. Significant differences between the fertile control group and group of infertility patients could be determined concerning the SME after mixing of fresh semen with 140 mOsm saline as well as after cryopreservation (Mann-Whitney-U-test). The discriminant analysis revealed a most discriminating effectiveness for SME immediately after the addition of hypoosmotic saline.

[Multiple pregnancy following in vitro fertilization and embryo transfer]

In a 32 year old patient 14 eggs were harvested and inseminated with donor semen. Six embryos were transferred resulting in a triplet-pregnancy. In spite of a septic disease three preterm but healthy children were born by caesarean section 199 days after ET (male 1620.0; female 1180.0; male 1560.0). Up to nowadays there is not any handicap. We don't know a general but safe method for avoiding multiple pregnancies.

The equatorial fibronectin band (EFB) on human spermatozoa--a diagnostic help for male fertility?

Spermatozoa were prepared by swim up technique in the same way as for in vitro fertilization of human eggs and incubated with antihuman fibronectin antibodies in the immunofluorescence technique. Fibronectin mediates adhesive interactions between cells. 69 p.c. of spermatozoa with a normal shape and only 17 p.c. of them exhibiting a pathological shape showed a positive fibronectin-fluorescent band on the equatorial segment, called equatorial fibronectin band (EFB). The cryopreservation of semen did not influence the EFB. The significance of EFB for the sperm-oocyte-binding is discussed in connection with the sperm morphology and epididymal function.

[Comments on reversible nonhormonal contraception in the male]

The development of substances that could be employed as male contraceptives would be of worldwide importance. As yet, however, it has not proved possible to find a substance which provides reliable contraception during use, whose effects are reversible following discontinuation, and which has minimal side-effects. Furthermore, the possibility of mutagenic effects and adverse effects on libido or sexual potency must be excluded and systemic application must be possible. The drugs gossypol, alpha-chlorohydrin and hexose derivates, which are presented in detail in this article, partly fulfil these requirements but are still a long way from representing an ideal compound for use as a male contraceptive. However, studies of these drugs may indicate ways of achieving the ultimate goal. The drugs showed interesting properties, which suggest that they may be used for purposes other than male contraception.

Measurements of membrane potential of human sperm using electrode sensitive to tetraphenyl phosphonium cations

For the first time, an attempt was made to measure the transmembrane potential of human spermatozoa by an electrode sensitive to the lipophilic cation tetraphenyl phosphonium (TPP+). However, the assumption of a single correlation between the decrease of the TPP+ concentration in the medium and metabolism-dependent membrane potential cannot be confirmed. The participation of different processes is very likely. Artificially damaged spermatozoa showed an enhanced affinity to TPP+ (the stronger the damage, the stronger the affinity of the spermatozoa to TPP+), but there were no significant differences of the cellular affinity to TPP+ between fresh and cryopreserved spermatozoa.

Risk of transmission of sexually transmitted diseases by cryopreserved semen

The increasing incidence of sexually transmitted diseases (STD) involves the risk of the transmission of these diseases by the artificial insemination. Therefore the cryotolerance of several microorganisms causing STD and the efficiency of penicillin of the cryoprotective medium (CMP) against Neisseria gonorrhoeae (N.g.) were investigated. The results have shown that penicillinase-producing N.g. (PPNG), genital mycoplasmas and Candida species survive the cryopreservation. Trichomonas vaginalis could not be recultivated after our temperature-time-regimen of the cryopreserving process. CPM with penicillin was unable to prevent a transmission of penicillin-sensitive N.g.

[Serum testosterone determination in the antiandrogen therapy of sexual deviations with cyproterone acetate (preliminary report of experiences)]

Total testosterone concentrations in the serum of patients treated with antiandrogens were measured by means of an industrially produced radioimmunological testosterone assay kit (VEB Sächsisches Serumwerk Dresden). Antiandrogen therapy using cyproterone acetate (Androcur) leads to a reduction in serum testosterone concentration which is significant at the p less than 0.01 level. The data suggest that testosterone concentrations vary inversely with increasing Androcur dosage; they are around 7 nmol/l at the doses conventionally administered. The testosterone concentrations obtained under depot-Androcur treatment suggest that intervals between injections should be less than 10 days.

[Effect of the epididymis on male fertility]

Out of the publications of the last three years concerning the influence of the epididymis on the male fertility those with practical relevance were reviewed. Several qualities of the spermatozoa were influenced by the epididymis: the metabolism, the functions of cell membrane, the fertilizing capacity, the ability to bind to zonae pellucidae of the oocytes and the motility. The motility depends on the electrolytes, androgenes, cAMP-system and the forward motility protein in the epididymis. Furthermore investigations exist dealing with the inhibition of the maturation of spermatozoa during the epididymal transit as a mean of contraception. The conclusion is supported that male fertility demands only a weak or a reversible disturbance of the epididymis. An other possibility would be the in vitro maturation of testicular spermatozoa.

Microbiological investigations on cryopreserved human semen

Primary mycological contamination was studied in 565 random human ejaculates. After sperm preservation at low temperature, secondary mycological contamination of 55 of the ejaculates was investigated. 25 ejaculates were cryopreserved with and without antibiotics and examined bacteriologically before and after different phases of cryopreservation. Furthermore, semen samples of several donors were inoculated with suspensions of different concentrations of yeasts and with the test bacteria Escherichia coli K 12 and Staphylococcus aureus SG 511. Microbiological results were then compared before and after cryopreservation. The following results were obtained: 1.9.8% of samples showed primary mycological contamination (1.9% with Candida albicans). 2. Cryopreservation reduced the concentration of fungi by more than 90% on average. 3. Only one semen sample was contaminated with bacteria (Staphylococcus aureus haemolyticus and Streptococcus nonhaemolyticus). Non-pathogenic bacteria were found in 11 ejaculates (Micrococcus luteus in 5 samples and Staphylococcus epidermidis in 6 samples), and contamination was largely unaffected by cryopreservation, even in the presence of antibiotics. 4. Test bacteria inoculated into semen were not influenced by the addition of antibiotics to the cryoprotective medium.

[Relations between sperm findings and fertility prognosis in childless couples]

In eight andrological centres more than 2,000 childless married men were examined catamnestically. Fertility was compared with the findings of the routine spermatograms. Conception rate is reduced significantly if sperm density is below 10 million, in motility of spermatozoa under 50% and in ejaculates with less than 60% normal-shaped spermatozoa. However, lower values of spermatozoa must not be compared with absolute infertility.