Aspiration flow cytometry of the testes in the evaluation of spermatogenesis in the infertile male

Evaluation of Stallion Testicular Cell Types by Flow Cytometry

Flow cytometry procedures can be used for evaluation of both spermatogenic efficiency and diagnose disorders of stallion spermatogenesis. Aims of this study were to compare two testicular sample acquisition techniques (needle aspirate-N and tissue wedge-T) and results when using flow cytometry and histology procedures. Testicular cell types were stained with acridine orange, and nine regions (R2 to R10) were identified and enumerated following acquisition by either N or T. Testes were also grouped and analyzed by size and sexual maturity (Small [immature] compared with Large [mature]) and used to determine if flow cytometry procedures could be used to detect differences. For both N and T, percentages of 2n cell types were greater in the Small than Large testes, whereas percentages of 1n cell types in N were greater in the Large than Small testes (P < .05). Testicular cell types in N regions were correlated to similar T regions (r between 0.51 and 0.99; P < .05) in both groups. Flow cytometry and histology scores were correlated in both groups (r between -0.95 and 0.93, P < .05). There were small differences in number of testicular cell types from N and T. With both sample acquisition methods, there was discrimination between the Small and Large testes, therefore, evaluation of testicular cell types using flow cytometry procedures might have clinical applications. Results with comparison of flow cytometry to histology procedures indicate that flow cytometry can be applied clinically to identify changes in testicular cell types of stallions using a needle aspirate.

Assessing reproductive and endocrine parameters in male largescale suckers (Catostomus macrocheilus) along a contaminant gradient in the lower Columbia River, USA

Persistent organochlorine pollutants such as polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p'-DDE), and polybrominated diphenyl ethers (PBDEs) are stable, bioaccumulative, and widely found in the environment, wildlife, and the human population. To explore the hypothesis that reproduction in male fish is associated with environmental exposures in the lower Columbia River (LCR), reproductive and endocrine parameters were studied in male resident, non-anadromous largescale sucker (Catostomus macrocheilus) (LSS) in the same habitats as anadromous salmonids having conservation status. Testes, thyroid tissue and plasma collected in 2010 from Longview (LV), Columbia City (CC), and Skamania (SK; reference) were studied. Sperm morphologies and thyrocyte heights were measured by light microscopy, sperm motilities by computer-assisted sperm motion analysis, sperm adenosine triphosphate (ATP) with luciferase, and plasma vitellogenin (VTG), thyroxine (T4), and triiodothyronine (T3) by immunoassay. Sperm apoptosis, viability, mitochondrial membrane potential, nuclear DNA fragmentation, and reproductive stage were measured by flow cytometry. Sperm quality parameters (except counts) and VTG were significantly different among sites, with correlations between VTG and 7 sperm parameters. Thyrocyte heights, T4, T3, gonadosomatic index and Fulton's condition factor differed among sites, but not significantly. Sperm quality was significantly lower and VTG higher where liver contaminants and water estrogen equivalents were highest (LV site). Total PCBs (specifically PCB-138, -146, -151, -170, -174, -177, -180, -183, -187, -194, and -206) and total PBDEs (specifically BDE-47, -100, -153, and -154) were negatively correlated with sperm motility. PCB-206 and BDE-154 were positively correlated with DNA fragmentation, and pentachloroanisole and VTG were positively correlated with sperm apoptosis and negatively correlated with ATP. BDE-99 was positively correlated with sperm counts and motility; T4 was negatively correlated with counts and positively correlated with motility, thus indicating possible androgenic mechanisms and thyroid endocrine disruption. Male LSS proved to be an informative model for studying reproductive and endocrine biomarkers in the LCR.

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007-2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed.

Limited repair of 8-hydroxy-7,8-dihydroguanine residues in human testicular cells

Oxidative damage in testicular DNA is associated with poor semen quality, reduced fertility and increased risk of stillbirths and birth defects. These DNA lesions are predominantly removed by base excision repair. Cellular extracts from human and rat testicular cells and three enriched populations of rat male germ cells (primary spermatocytes, round spermatids and elongating/elongated spermatids) all showed proficient excision/incision of 5-hydroxycytosine, thymine glycol and 2,6-diamino-4-hydroxy-5-formamidopyrimidine. DNA containing 8-oxo-7,8-dihydroguanine was excised poorly by human testicular cell extracts, although 8-oxoguanine-DNA glycosylase-1 (hOGG1) was present in human testicular cells, at levels that varied markedly between 13 individuals. This excision was as low as with human mononuclear blood cell extracts. The level of endonuclease III homologue-1 (NTH1), which excises oxidised pyrimidines, was higher in testicular than in somatic cells of both species. Cellular repair studies of lesions recognised by formamidopyrimidine-DNA glycosylase (Fpg) or endonuclease III (Nth) were assayed with alkaline elution and the Comet assay. Consistent with the enzymatic activities, human testicular cells showed poor removal of Fpg-sensitive lesions but efficient repair of Nth-sensitive lesions. Rat testicular cells efficiently repaired both Fpg- and Nth-sensitive lesions. In conclusion, human testicular cells have limited capacity to repair important oxidative DNA lesions, which could lead to impaired reproduction and de novo mutations.

Highly efficient base excision repair (BER) in human and rat male germ cells

The quality of germ cell DNA is critical for the fate of the offspring, yet there is limited knowledge of the DNA repair capabilities of such cells. One of the main DNA repair pathways is base excision repair (BER) which is initiated by DNA glycosylases that excise damaged bases, followed by incision of the generated abasic (AP) sites. We have studied human and rat methylpurine-DNA glycosylase (MPG), uracil-DNA glycosylase (UNG), and the major AP endonuclease (HAP1/APEX) in male germ cells. Enzymatic activities and western analyses indicate that these enzymes are present in human and rat male germ cells in amounts that are at least as high as in somatic cells. Minor differences were observed between different cellular stages of rat spermatogenesis and spermiogenesis. Repair of methylated DNA was also studied at the cellular level using the Comet assay. The repair was highly efficient in both human and rat male germ cells, in primary spermatocytes as well as round spermatids, compared to rat mononuclear blood cells or hepatocytes. This efficient BER removes frequently occurring DNA lesions that arise spontaneously or via environmental agents, thereby minimising the number of potential mutations transferred to the next generation.

Quantitation of spermatogenesis by DNA flow cytometry from fine-needle aspiration cytology material

DNA flow cytometry (FCM) was performed from fine-needle aspiration cytology (FNAC) of testis in 15 cases of male infertility to quantitate spermatogenesis. The results were correlated with FNAC findings. DNA FCM showed a ploidy relationship of haploid (1N) > diploid (2N) > tetraploid (4N) in cases of normal spermatogenesis. A ploidy relation of 2N > 1N > 4N was observed in cases of hypospermatogenesis or maturation arrest. In Sertoli cell-only cases, there were only 2N populations of cells. With the help of DNA FCM, a rapid and objective assessment of spermatogenesis is possible from FNAC of the testis.

The impact of ofloxacin on rat testicular DNA: application of image analysis

Ofloxacin induces its antibacterial action mainly by inhibition of DNA gyrase which is equivalent to topoisomerase II in mammalian cells. The present study was focused on the impact of ofloxacin on rat testicular DNA ploidy in a dose-response relationship using an image analysis technique on testicular sections following Fuelgen DNA staining. Sperm count and motility as well as sperm head abnormality tests were also investigated. Ofloxacin was given p.o. in doses of 36, 72 and 360 mg kg(-1) day(-1) for 15 consecutive days. The animals were then left to live safely to day 60 from starting the experiment to give them a chance to complete the cycle of spermatogenesis. Results revealed that ofloxacin significantly decreased the percentage of haploid cells in a dose-dependent manner with concomitant increase in the percentage of diploid cells. Sperm count and motility was also markedly decreased in a dose-dependent fashion. Sperm head abnormality showed no marked change following ofloxacin treatment. In conclusion, ofloxacin induced a marked disturbance in rat testicular DNA ploidy, which may be explained on the basis of cross-reactivity to topoisomerase II.

Testicular fine needle aspiration: the alternative method for sperm retrieval in non-obstructive azoospermia

The objective of this prospective open study was to determine the feasibility of obtaining mature spermatozoa for intracytoplasmic sperm injection (ICSI) by testicular fine needle aspiration (TEFNA) in men diagnosed with non-obstructive azoospermia. TEFNA consisted of a mean of 15 punctures and aspirations in each testis, using 23 gauge butterfly needles, connected to a 20 ml syringe with an aspiration handle. Patients (n = 85) underwent 111 TEFNA cycles. Mature testicular spermatozoa were recovered in 65 (58.5%) cycles from 50 (58.8%) patients. The sperm recovery rate by testicular histology was 14 out of 29 (48.3%) in patients with Sertoli cell-only, 13 out of 28 (46.4%) in patients with maturation arrest, 19 out of 20 (95%) in patients with hypospermatogenesis, four out of six (66.6%) in patients with tubular hyalinization due to non-mosaic Klinefelter's syndrome. No spermatozoa were found in two cases with post-irradiation fibrosis. ICSI was performed in all 65 cycles. In 58 cycles in which only the husbands' spermatozoa were used, 406 mature oocytes were injected, and 154 (37.9%) were normally fertilized. Of the 143 embryos that developed (92.8%), 119 were transferred in 42 cycles resulting in 18 clinical pregnancies (42. 8%), with 31 gestational sacs, providing an implantation rate of 26%. One abortion of a singleton pregnancy occurred (5.6%). No major side-effects, such as haematoma or infection were recorded. In conclusion, we have found TEFNA to be efficient, easy to learn, safe and well tolerated by all patients. In our opinion, TEFNA should be considered the first choice whenever sperm recovery is attempted in patients with non-obstructive azoospermia.

Advances in the evaluation and treatment of the infertile man

Numerous advances in technology have been made in the last several years in the diagnosis and treatment of the infertile man. Using case presentations, this article highlights these important new developments and reviews the basics of a comprehensive male infertility evaluation. The use of ultrasound as a critical, indispensable, yet noninvasive tool in the evaluation of possible male reproductive tract obstruction is discussed. Since assisted reproductive techniques (ARTs) have become increasingly important in the management of the otherwise untreatable infertile man, specialized testing of sperm function, e.g., the sperm penetration assay (SPA), and strict morphology assessment are often useful prior to the initiation of some of these assisted reproductive procedures such as intrauterine insemination (IUI) or in vitro fertilization (IVF). Testicular touch preparation cytology and image analysis are also important additions to routine testicular biopsy for quantifying the extent of spermatogenesis. Finally, the revolutionary micromanipulation procedure of intracytoplasmic sperm injection (ICSI) has forever changed the practice of andrology by enabling men previously thought to be irreversibly infertile the chance to initiate their own biologic pregnancy.

Image analysis assessment of the abnormal testis biopsy in male infertility

PURPOSE

We previously demonstrated that testis biopsy image analysis is an effective method for quantifying intratubular spermatogenic cells in the obstructed testis with normal spermatogenesis. As an extension of the initial report, we describe using the quantitative ploidy and morphological characteristics of cells counted with image analysis in abnormal testis biopsies obtained for a male infertility evaluation.

MATERIALS AND METHODS

Image analysis using a specifically designed filter was performed on Feulgen stained 5 microns, sections of paraffin embedded testicular tissue. Archival testicular tissue had been obtained using standard biopsy techniques from patients with azoospermia or severe oligospermia. Qualitative classification was based on standard evaluation of hematoxylin and eosin processed tissue.

RESULTS

There were 62 biopsies performed in 58 men. Significant differences in the intratubular content of haploid (spermatozoa and spermatids), diploid and tetraploid cells were found among the 5 categories of abnormalities: the Sertoli-cell-only syndrome, spermatocyte arrest, spermatid arrest, hypospermatogenesis and normal spermatogenesis. Moderate variability was found in the proportion of cell types in spermatid arrest and hypospermatogenesis.

CONCLUSIONS

Testis biopsy image analysis provides a quantitative method for categorizing abnormalities of intratubular cell content present in male infertility states by using deoxyribonucleic acid content and morphology characteristics. The limitations of the present qualitative analysis system are emphasized by the moderate variability evident within the current categories of spermatid arrest and hypo-spermatogenesis states.

Assessment of spermatogenic process by deoxyribonucleic acid image analysis

OBJECTIVE

To evaluate the spermatogenic process through cellular ploidy by image analysis.

DESIGN

Twenty-six testicular aspirates from 24 infertile men were examined by fine needle aspiration (FNA) cytologic smears. These results were compared with the ploidy content of the cells using Feulgen stain, determined by image analysis.

RESULTS

The results of both methods were divided into three categories: full spermatogenesis, spermatogenic arrest, and only Sertoli cell. There was a good correlation in 25 of 26 smears (96%). Ten patients who had a histogram of diploid showed only Sertoli cell cytologically. From nine patients who had a histogram of diploid and tetraploid, eight cytologically showed spermatogenic arrest and one showed full spermatogenesis. The seven patients who had full spermatogenesis (haploid, diploid, tetraploid) all had normal cytologic smears.

CONCLUSIONS

Deoxyribonucleic acid image analysis is an objective qualitative and quantitative method for the evaluation of the spermatogenic process of the infertile male. It has several advantages over the flow cytometry method.

Utilization of a short-term male reproductive toxicity study design to examine effects of alpha-chlorohydrin (3-chloro-1,2-propanediol)

alpha-Chlorohydrin (ACH) was administered to rats in a short-term male reproductive toxicity study to examine the usefulness of the method and to provide reference data with a substance that is known to elicit adverse effects on both sperm production and sperm quality within or following a 2-week treatment period. Adult male CD rats (10 per group) were administered ACH orally by gavage at doses of 0, 1, 5, or 25 mg/kg/day for 14 days. Males were killed on Test Day (TD) 15 or 29. A 2-week period without treatment was included to distinguish between testicular and posttesticular effects. At each time point, the reproductive system was evaluated by comparing testes weight, DNA ploidy distributions of testicular cell suspensions, testicular and epididymal histopathology, and epididymal sperm concentration, motility, morphology, and breakage. Beginning on TD 14, males to be killed on TD 29 were cohabited with untreated females (1:2). Females were killed on Gestation Day 13 and examined for pregnancy status. During the treatment period, minor depressions in body weight and relative food consumption occurred in rats administered 25 mg/kg ACH. Testicular and epididymal lesions also occurred at this dose level. DNA ploidy distributions determined by flow cytometry were predictive of testicular damage, with effects more pronounced on TD 29 than on TD 15. The preparation methods used selected for the most motile and vigorous population of epididymal sperm. Sperm motion was altered at the 5- and 25-mg/kg dose levels on TD 15. The percentage of motile sperm and the percentage of progressively motile sperm were markedly depressed at both the 5- and 25-mg/kg dose levels where antifertility effects occurred. Sperm velocities and amplitude of lateral head displacement were depressed at the 25-mg/kg dose level on both TD 15 and 29. Additionally, decreased epididymal sperm concentrations and increased breakage were recorded at this dose level. The findings in this study are consistent with the scientific literature for ACH and demonstrate posttesticular effects on epididymal sperm and delayed expression of testicular lesions. They also support the use of this methodology for an initial assessment of male reproductive effects.

Quantification of spermatogenesis by dual-parameter flow cytometry

OBJECTIVE

To investigate the usefulness of dual-parameter flow cytometry of testicular fine-needle aspirates for the quantification of spermatogenesis. Immunofluorescence staining for vimentin was introduced to discriminate vimentin-negative germ cells from vimentin-positive stromal cells. The results of flow cytometry were compared with testicular morphology and immunohistochemistry in cases of regular and disturbed germ cell maturation.

DESIGN

Testicular fine-needle aspiration and surgical biopsy were performed in 50 autopsy cases. The fine-needle aspirates were double stained for the intermediate filament vimentin by indirect immunofluorescence and DNA propidium iodide and analyzed by flow cytometry. Surgical biopsies were examined by light microscopy. The distribution of vimentin-positive cells was evaluated by immunohistochemistry.

RESULTS

A comparison of morphology and flow cytometric analysis yielded characteristic quantitative distribution patterns of the different germ cell and somatic cell populations in regular and disturbed spermatogenesis. All three ploidy compartments of the germ epithelium correlated with high statistical significance with the respective histologic diagnoses. Moreover, a marked quantitative increase of stromal cells could be demonstrated in spermatogenetic disorders.

CONCLUSIONS

The simultaneous analysis of the cellular DNA content and the intermediate filament vimentin by flow cytometry enables a detailed investigation of spermatogenetic disorders. Quantitative changes of the relationships between germ cells and somatic cells can be selectively investigated.

Objective assessment of spermatogenesis in men with functional and anatomic obstruction of the genital tract

Experimental rodent models simulating the condition of neurogenic infertility have drawn attention to the role of potential epididymal dysfunction as an underlying cause. This functional obstruction of the genital tract is comparable to the outcome of genital tract obstruction after vasectomy, and may explain the common finding of asthenospermia in both groups following either stimulated semen recovery or vasovasostomy, respectively. Since spermatogenic dysfunction has been reported in spinal cord injury, the relative roles of defective sperm production and sperm transport remain to be determined in men with neurogenic infertility. The objective of this study was to compare the levels of spermatogenesis in groups of vasectomized men and those with spinal cord injury, using objective measurement criteria for spermatogenesis. Groups of 10 spinal cord-injured and six vasectomized men matched for age and duration of disease, underwent incisional testicular biopsy. The specimens were divided equally for parallel quantitation of spermatogenesis by both quantitative cytometry and DNA flow cytometric analysis. Quantitative parameters showed similar values for both groups with reference to mean tubular wall thickness, mean tubular concentration of spermatids and Sertoli cells, as well as the mean spermatid: Sertoli cell ratio per tubule. Additionally, similar percentages of 1N, 2N and 4N cells, were found in both groups. Based on these preliminary findings this study provides a clinical correlation supporting the experimental observation that both anatomical and functional obstruction of the male genital tract exert a similar although minor spermatogenic insult, and that in both the putative cause for neurogenic infertility is more likely to be at the post-testicular level.

The value of quantitative DNA flow cytometry of testicular fine-needle aspirates in assessment of spermatogenesis: a study of 137 previously maldescended human testes

In order to assess the suitability of DNA flow cytometry of fine-needle aspirates for quantifying spermatogenesis, the results from DNA flow cytometry were compared to histological evaluation of testicular biopsies taken concomitantly from 171 previously maldescended testes. In 137 of 171 cases, sufficient material for flow cytometric as well as histological evaluation was obtained. Histological analysis of surgical biopsy specimens revealed spermatogenesis including the spermatid stage in 117 of the 137 gonads. In six of the 117 gonads no haploid cells were found using flow cytometry. On the other hand, surgical biopsies failed to reveal spermatogenesis in five cases in which the corresponding aspirates contained haploid cells. Both methods therefore seem equally sensitive in detection of spermatogenesis. Other types of histological patterns also corresponded to distinct DNA histograms. Thus, in 11 of 12 cases with Sertoli-cell-only pattern in all tubules, at least 95% of the cells had a diploid DNA content. Furthermore, predominance of tubules with maturation arrest at the primary spermatocyte level corresponded to an increased proportion of tetraploid cells. When compared to surgical biopsy, DNA flow cytometry of testicular fine-needle aspirates is a more objective, easy and rapid method, which is more convenient for the patient. This study has indicated that DNA flow cytometry is a suitable method of quantitative assessment of spermatogenesis. One of the first target groups might be men with azoospermia. In such men, DNA flow cytometric analysis of fine-needle aspirates and surgical biopsy are apparently of equal sensitivity in detecting gonads with spermatogenesis. We conclude that DNA flow cytometry may become an alternative method for the quantification of spermatogenesis.

Simplified and objective assessment of spermatogenesis in spinal cord injured men by flow cytometry analysis

Deterioration of the germinal epithelium of the testis is a known sequela of spinal cord injury (SCI) that may influence the outcome of male reproductive rehabilitation efforts. Quantitative testicular biopsy, currently regarded as the standard of assessing the integrity of spermatogenesis, has not gained wide-spread clinical use because of its invasive nature and relative technical complexity. Alternatively, aspiration DNA flow cytometry analysis of the testis has offered a potential method of spermatogenic assessment that meets both the requirements of simplicity and objectivity. The objective of this study is to determine the capability of flow cytometry to assess spermatogenesis following SCI. Eleven SCI men underwent incisional testicular biopsy with the specimen simultaneously submitted for quantitative evaluation of the germinal epithelium by both quantitative histometry and DNA flow cytometry. The haploid percentage of cells showed highly significant levels of correlation with key micrometric parameters of the quantitative testicular biopsy: spermatid/tubule (p < 0.002) and the spermatid/Sertoli cell ratio (p < 0.0005). Since tissue procurement is accomplished less invasively for flow cytometry analysis, we recommend this method as the modality of assuring integrity of the germinal epithelium in candidates for reproductive rehabilitation.

Validation of flow cytometry analysis in the objective assessment of spermatogenesis: comparison to the quantitative testicular biopsy

Objective determination of spermatogenesis has been accomplished by quantitative testicular biopsy, which, although laborious, has served as the standard for spermatogenic assessment. Aspiration deoxyribonucleic acid (DNA) flow cytometry of the testis, however, has simplified this determination, and has correlated with indirect hormonal parameters of spermatogenesis and qualitative observations of the seminiferous epithelium. Nevertheless, this important modality has yet to be validated against quantitative micrometry of the testis. To determine this correlation we submitted 29 incisional testicular biopsies for simultaneous quantitative analysis and DNA flow cytometry. Micrometric parameters included the mean tubular wall thickness, and the mean tubular concentration of late spermatids and Sertoli cells. The percentage of haploid, diploid and tetraploid cells was determined for each patient. For the entire patient population a statistically significant correlation was observed between the percentage of haploid cells and the tubular concentration of late spermatids (r = 0.784, p < 0.0005) as well as the mean tubular spermatid-to-Sertoli cell ratio (r = 0.824, p < 0.0005). A similar correlation was noted for various etiological subsets of patients: spinal cord injury (r = 0.809, p < 0.002), genital tract obstruction (r = 0.705, p < 0.02) and miscellaneous diagnoses (r = 0.828, p < 0.02). For the group with testicular failure quantitative micrometry and flow cytometry demonstrated severe impairment in all patients although a statistically significant correlation could not be shown because of the small range of values. DNA flow cytometry analysis correlates strongly with the current standard of quantitative spermatogenic assessment and, therefore, it may be validated as a simplified and highly objective method of determining spermatogenesis.

The value of quantitative testicular biopsy and deoxyribonucleic acid flow cytometry in predicting sperm recovery from electrostimulated ejaculates

Spermatogenic abnormalities have been reported in the majority of men following spinal cord injury, and they contribute to the multifactorial etiology of reproductive dysfunction. Thus far, few have studied the seminiferous epithelium in this group of patients by objective criteria. While quantitative micrometry and flow cytometric analysis are accurate and reproducible methods of quantitating spermatogenesis, the latter is simpler and permits needle aspiration for tissue recovery. The objective of this study is to determine the value of quantitative micrometry and flow cytometric analysis as methods of predicting total sperm yield in electrostimulated ejaculates. Incisional testicular biopsy was performed in 12 anejaculatory men, and the tissue specimens were divided for analysis by quantitative micrometry and flow cytometric analysis. Quantitative micrometry consisted of determining the mean tubular wall thickness, mean tubular concentration of the Sertoli cells and mature spermatids in a minimum of 10 round seminiferous tubules per patient. Specimens were prepared for flow cytometric analysis and the deoxyribonucleic acid histogram was analyzed to determine the percentage of cells in each ploidy compartment. Of the quantitative micrometry parameters analyzed a significant correlation resulted between the total sperm yield per electroejaculate and the mean tubular concentration of late spermatids (p = 0.001) as well as with the mean tubular ratio of late spermatids to Sertoli cells (p = 0.003). The tubular concentration of spermatids resulted in a sensitivity and specificity of 100% and 75%, respectively, to predict adequate sperm yield in semen. Likewise, the mean tubular ratio of spermatids to Sertoli cells resulted in a sensitivity and specificity of 75% and 87.5%, respectively, in its ability to predict normal sperm yield in the recovered ejaculate. Deoxyribonucleic acid flow cytometry analysis showed a normal haploid compartment in all 6 specimens studied, and each was associated with high numbers of sperm in recovered semen. Quantitative histometric parameters correlate significantly with the total sperm yield obtained in electrostimulated ejaculates and may have a role in the selection of candidates for treatment in reproductive rehabilitation programs.

Deoxyribonucleic acid flow cytometry and semiquantitative histology of spermatogenesis: a comparative study

OBJECTIVE

To compare deoxyribonucleic acid (DNA) flow cytometry with a semiquantitative histologic method for the assessment of spermatogenesis and to investigate the influence of various preparative techniques on the results of DNA measurements.

DESIGN

Testicular tissue from 52 autopsies was examined for spermatogenesis by DNA flow cytometry and by conventional semiquantitative histology. Flow cytometry was performed on single nuclei suspensions from fine needle aspiration biopsies, resuspended imprints, as well as on specimens obtained by mechanical disaggregation of surgical biopsies of the same testis.

RESULTS

In all cases, flow cytometry revealed a characteristic distribution pattern of haploid (n), diploid (2n), and tetraploid (4n) cells independent of the preparation technique used. The percentage of haploid cells of the testes showed statistically highly significant correlations (P = 0.0002) with the results of semiquantitative histology. Fine needle aspiration biopsy always contained more haploid cells compared with resuspended imprints and mechanically disaggregated samples.

CONCLUSION

Our results confirm the suitability of DNA flow cytometry as a fast and reliable quantitative method for the assessment of spermatogenesis and demonstrate its optimal feasibility in combination with fine needle aspiration biopsy.

Flow cytometry of fine needle aspirations of the Sprague-Dawley rat testis: defining normal maturation and the effects of multiple biopsies

Quantitative assessment of spermatogenesis by flow cytometry reproducibly correlates with histological examination. Flow cytometry of fine needle aspirates from the testis was used to analyze normal spermatogenesis of Sprague-Dawley rats. Aged matched male weanlings were divided into 3 groups: group 1-5 rats underwent bilateral percutaneous aspiration of the testes with a 22 gauge Chiba needle on postpartum days 19, 24, 30 and 40; group 2-5 rats aspirated on days 24, 30 and 40, and group 3-4 rats aspirated on days 30 and 40. This sequential approach allowed for evaluation of normal spermatogenesis and the effects of repeated fine needle aspiration on spermatogenesis. Deoxyribonucleic acid distribution analysis by flow cytometry correlates with haploid (1N), diploid (2N), tetraploid (4N) and S phase cell populations. These cell populations were evaluated and comparisons among each group were made at all biopsy times. No significant differences in mean 2N, 4N or S phase cell populations in single versus repeat biopsied testes were detected. However, there was a significant increase in the 1N population at 30 days post partum in the repeat biopsy group (p = 0.037), which normalized by day 40. This increase in 1N corresponds to the beginning of meiosis, which is maximal between postpartum days 30 and 40, and occurs earlier in the repeat biopsied testis. Repeat fine needle aspiration of the testis can be performed without significantly affecting spermatogenesis in the "weanling" rat. This provides a useful technique in the future investigations of the time related effects of varicocele, chemotherapy and toxicologic drugs on spermatogenesis.

The flow cytometric analysis of undescended testes in children

Flow cytometric analysis was performed on the testicular aspirates of 45 consecutive children with unilateral cryptorchidism undergoing elective orchiopexy or orchiectomy. Concomitant histological analysis was performed on the testicular tissue obtained from either biopsy or orchiectomy specimens. In all cases deoxyribonucleic acid histograms appeared to correspond with microscopic appearance. Histograms from prepubescent patients demonstrated 85 to 95% of cells in the diploid (2c) peak and less than 10% of cells in the tetraploid peak (4c), representing prepubertal testes without active spermatogenesis. Three distinct patterns of ploidy were identified in postpubertal children corresponding to the histological appearances of normal spermatogenesis, maturation arrest and the Sertoli-cell-only syndrome, respectively. In addition, we identified an aneuploid cell population in the specimen from 1 patient, suggesting that this testis may be at risk for future malignant degeneration. We conclude that flow cytometry of testicular aspirates is an easy and effective means of testicular evaluation, which may permit predictions regarding the fertility and malignant potential of undescended testes in postpubertal children.

Comparison of flow cytometry to routine testicular biopsy in male infertility

We compared DNA flow cytometry to morphologic evaluation of routine testicular biopsies as methods of monitoring spermatogenesis. The study group consisted of 14 azoospermic men and 5 others who underwent testicular surgery unassociated with fertility problems. The findings for both studies were divided into three groups: normal, moderately abnormal, and markedly abnormal. Correlations between the findings from routine biopsy and flow cytometry were good. Of 9 patients having normal testicular morphology, 7 had normal ploidy classes by DNA flow cytometry while 2 had moderately abnormal histograms. Of 5 cases with moderately abnormal morphology, 1 had normal, 1 had moderately abnormal, and 3 had markedly abnormal ploidy distributions. In 5 cases described as Sertoli cell only, all DNA histograms were markedly abnormal, consisting almost exclusively of diploid cells. DNA flow cytometry of testicular biopsies and aspirates has been demonstrated to be a rapid, reproducible, and objective approach in evaluating the infertile male and is a promising method to investigate spermatogenesis in an outpatient clinic in lieu of formal testis biopsy.

Carcinoma in situ of the testes: diagnosis by aspiration flow cytometry

Carcinoma in situ of the testes has been described as a premalignant state with the potential to progress to invasive carcinoma. A history of testicular carcinoma, cryptorchidism, somatosexual ambiguity and infertility has been identified as a risk factor for carcinoma in situ. A series of 25 infertility patients underwent aspiration biopsy of the testis as part of a study protocol to assess spermatogenesis. Of these patients 1 had a unilateral seminoma. In accordance with the study protocol the contralateral testis was aspirated at radical orchiectomy and the deoxyribonucleic acid histogram generated demonstrated an aneuploid peak. Carcinoma in situ subsequently was noted on tissue biopsy. The discovery of carcinoma in situ cells in this manner highlights the potential of this technique as a diagnostic tool for the screening and followup of men at increased risk for carcinoma in situ.

Use of biopty gun for transcutaneous testicular biopsies

Needle biopsies are being performed commonly as a substitute for open biopsy in certain patients in whom a tissue diagnosis is necessary to determine therapy. During the last few years the Biopty gun and its through-cut needle have evolved as a satisfactory method to perform prostate biopsy in a rapid and painless manner. To determine whether the Biopty gun could be used to perform testicular biopsies 7 patients underwent this procedure in an outpatient setting. The patients received cutaneous lidocaine and the special through-cut needle (already inserted in the gun) was inserted painlessly through this cutaneous wheal towards the tunica albuginea of the testis. The gun was fired and in less than a fraction of a second a biopsy was obtained. The needle was removed and the tissue was placed in Bouin's solution. In some patients more than 1 biopsy was performed. None of the biopsies took more than 5 minutes, none of the patients required postoperative analgesia and none felt untoward discomfort during the biopsy. All biopsies obtained adequate tissue to diagnose the presence of sperm. These results demonstrate that needle biopsy of the testis with the Biopty gun system is a cost-effective, rapid, safe, relatively harmless and effective way to obtain a testicular biopsy to identify the presence of sperm. With time this percutaneous method may supercede other open and percutaneous methods of testicular biopsy.

The clinical application of aspiration deoxyribonucleic acid flow cytometry to neurologically impaired men entering an electroejaculation program

For the neurologically impaired patient electroejaculation with a rectal probe can furnish sperm for artificial insemination. However, documentation of pregnancies in this patient group has been limited. Deoxyribonucleic acid flow cytometry has been shown to be a reproducible quantitative method with which to evaluate spermatogenesis. We assessed the ability of deoxyribonucleic acid flow cytometry on testicular aspirates to predict the quality of sperm production in 13 men undergoing electroejaculation. Semen analysis was performed on antegrade and retrograde specimens. Deoxyribonucleic acid histograms from testicular aspirates were evaluated for the relative proportions of haploid, diploid and tetraploid cells. These ratios were compared to the means reported for our own series of 25 patients who at vasovasostomy had sperm intraoperatively and to the similar figures from a group of 10 accident victims. Five patients had normal testicular ploidy compartments defined as within 2 standard deviations from control means. Of the 5 patients 4 had normal sperm counts and motilities (30 per cent or greater). Two patients have contributed sperm for artificial insemination; 1 has resulted in pregnancy. Three patients had moderately abnormal (2 to 4 standard deviations) testicular ploidy classes. These patients had adequate sperm counts but low motilities (5 per cent or less). Of the 5 patients with markedly abnormal (greater than 4 standard deviations) histograms 4 remained azoospermic despite repeated attempts at electroejaculation. Our data support the use of deoxyribonucleic acid flow cytometry on testicular aspirates as a predictor of which patients might succeed and those who are unlikely to succeed in an electroejaculation program.

Evaluation of vasovasostomy candidates by deoxyribonucleic acid flow cytometry of testicular aspirates

Flow cytometry can be performed on testicular aspirates of vasovasostomy candidates preoperatively. On the basis of ploidy ratios and debris components, DNA histograms can be classified as normal or abnormal. Using this method, the likelihood of the presence of sperm may be predicted.