Nonmotile Sperm Research Articles

The effect of L-Arginine of treatment for infertile men on semen parameters

The aim of the study is to determine the effect of oral supplement of L-Arginine on semen parameters as a treatment for infertile men. Patients and methods: The study conducted on 15 infertile men at infertility clinic in SalahadDin general hospital and private clinics and laboratories in Tikrit city from beginning of March to the end of July 2018. Infertility is a common clinical problem affecting 13-15% of couples worldwide. The prevalence varies throughout developed and undeveloped countries, being higher in the latter in which limited resources for diagnosis and treatment exist. L-arginine was given daily and orally at a dose 1000 mg one capsule per day morning after breakfast.
 Results: There was a significant increase in total sperm count after treatment with L- Arginine as compare with that before treatment. Also there was significant elevation active motility and Ejaculate volume after treatment with L- Arginine, as compare with that before treatment. However, there are significant reductions in Sluggish motility, abnormal sperm shape and non-motile sperms after treatment with L-Arginine as compare with that before treatment. 
 
 http://dx.doi.org/10.25130/tjps.24.2019.08

The effect of L-Arginine of treatment for infertile men on semen parameters

The aim of the study is to determine the effect of oral supplement of L-Arginine on semen parameters as a treatment for infertile men. Patients and methods: The study conducted on 15 infertile men at infertility clinic in SalahadDin general hospital and private clinics and laboratories in Tikrit city from beginning of March to the end of July 2018. Infertility is a common clinical problem affecting 13-15% of couples worldwide. The prevalence varies throughout developed and undeveloped countries, being higher in the latter in which limited resources for diagnosis and treatment exist. L-arginine was given daily and orally at a dose 1000 mg one capsule per day morning after breakfast.
 Results: There was a significant increase in total sperm count after treatment with L- Arginine as compare with that before treatment. Also there was significant elevation active motility and Ejaculate volume after treatment with L- Arginine, as compare with that before treatment. However, there are significant reductions in Sluggish motility, abnormal sperm shape and non-motile sperms after treatment with L-Arginine as compare with that before treatment.

Premeiotic and meiotic failures lead to hybrid male sterility in the Anopheles gambiae complex.

Hybrid male sterility (HMS) contributes to speciation by restricting gene flow between related taxa. Detailed cytological characterization of reproductive organs in hybrid males is important for identifying phenotypes that can help guide searches of speciation genes. To investigate possible cellular causes of HMS, we performed crosses between closely related species of the Anopheles gambiae complex: An. merus with An. gambiae or An. coluzzii. We demonstrate that HMS in African malaria mosquitoes involves two defects in the reciprocal crosses: a premeiotic arrest of germline stem cells in degenerate testes and a failure of the reductional meiotic division of primary spermatocytes in normal-like testes. The premeiotic arrest in degenerate testes of hybrids is accompanied by a strong suppression of meiotic and postmeiotic genes. Unlike pure species, sex chromosomes in normal-like testes of F1 hybrids are largely unpaired during meiotic prophase I and all chromosomes show various degrees of insufficient condensation. Instead of entering reductional division in meiosis I, primary spermatocytes prematurely undergo an equational mitotic division producing non-motile diploid sperm. Thus, our study identified cytogenetic errors in interspecies hybrids that arise during the early stages of postzygotic isolation.

Numerical analysis of the buckling and recuperation dynamics of flexible filament using an immersed boundary framework

The dynamics of flexible filaments in viscous shear flow is of interest to biologists and engineers in a wide variety of applications involving folding and unfolding sequence of long-chain biomolecules like DNA, non-motile sperm and microalgae. It is also helpful in understanding the deformation of natural and synthetic fibers which can be applied in areas such as biotechnology. In the present work, deformation and migration behavior of non-motile unicellular phytoplankton diatoms subjected to viscous shear flow are considered. These unicellular diatoms develop into colonies which are made up of linked chains. The complex fluid-structure interaction is solved by developing a two-dimensional numerical model with an immersed boundary framework. The simulation consists of suspending an elastic filament mimicking a diatom chain in a shear flow at low Reynolds number. The governing continuity and Navier–Stokes equations are solved on a Cartesian grid arranged in a staggered manner. A forcing term is added to the momentum equation that incorporates the presence of flexible filament in the fluid domain. The discretization of the governing equation is based on a finite volume method, and a SIMPLE algorithm is used to compute pressure and velocity. A computer code is developed to perform numerical simulations, and the model is first verified with the deformation study of a tethered flexible filament in uniform fluid flow. Next, the shape deformations for flexible filament placed freely in shear flow are compared with the studies of previous researchers. Further, the present results are validated with Jeffery's equation for particles immersed in shear flow along with classification plot for filament orbit regimes. All of these comparisons provide a reasonable validity for the developed model. The effect of bending rigidity and shear rate on the deformation and migration characteristics is ascertained with the help of parametric studies. A non-dimensional parameter called Viscous Flow Forcing value (VFF) is calculated to quantify the parametric results. An optimum Viscous Flow Forcing value is determined which indicates the transition of filaments exhibiting either a recuperative (regaining original shape past deformation) or non-recuperative (permanently deformed) behavior. The developed model is successful in capturing fluid motion, diatom buckling, shape recurrences and recuperation dynamics of diatom chains subjected to shear flow. Further, the developed computational model can successfully illustrate filament-fluid interaction for a wide variety of similar problems.

060 Discrepancy Between Vasectomy Guidelines and Practice Patterns in the Post 2012 AUA Guideline Era: What have we Learned?

In 2012, the American Urological Association published vasectomy guidelines to guide clinicians in best practices. To assess practice patterns of post-vasectomy semen analyses (PVSA) in a large, community cohort. We analyzed a database of men who underwent PVSA between 2011 and 2017 at a centralized laboratory. Samples were collected both on- and off- site. Samples collected off-site were transported to the laboratory in 40 ml of nutrient solution to maintain motility, if present. Samples were centrifuged if initial evaluation revealed azoospermia. Vasectomies were performed by both urologic and non-urologic providers in both academic and community settings. A total of 5,596 men underwent PVSA with 1,095 (19.5%) undergoing one or more repeat analyses. On initial analysis, 3,211 (57.4%) were azoospermic, 1,622 (28.9%) had rare non-motile sperm (<100k), 495 (8.8%) had >100k non-motile sperm, and 258 (4.6%) had motile sperm. Several observations were inconsistent with AUA guidelines. 11.7% (376) of patients with initial azoospermia had a repeat analysis, of whom 6.1% had rare non-motile sperm and 0.5% (2/376) had motile sperm (subsequent failure after initial clearance). 26.6% (431) of patients with rare non-motile sperm on initial semen analysis underwent repeat semen analysis, with 76.8% (331) of these men demonstrating azoospermia, 21.6% (93) with persistent non-motile sperm, and, importantly, 0% developing motile sperm. Of men with >100k non-motile sperm on initial analysis, 60.0% (297) did not obtain a repeat semen analysis, contrary to current AUA recommendations. Among the 198 men who did obtain a repeat analysis after an initial analysis with >100k non-motile sperm, 86.4% (167) were downgraded to either rare non-motile sperm or azoospermia at last semen analysis, 13.6% (27) had persistent >100k non-motile sperm, and 0% (0) subsequently developed motile sperm.

A Fruitful Journey: Pollen Tube Navigation from Germination to Fertilization

In flowering plants, pollen tubes undergo tip growth to deliver two nonmotile sperm to the ovule where they fuse with an egg and central cell to achieve double fertilization. This extended journey involves rapid growth and changes in gene activity that manage compatible interactions with at least seven different cell types. Nearly half of the genome is expressed in haploid pollen, which facilitates genetic analysis, even of essential genes. These unique attributes make pollen an ideal system with which to study plant cell-cell interactions, tip growth, cell migration, the modulation of cell wall integrity, and gene expression networks. We highlight the signaling systems required for pollen tube navigation and the potential roles of Ca2+ signals. The dynamics of pollen development make sexual reproduction highly sensitive to heat stress. Understanding this vulnerability may generate strategies to improve seed crop yields that are under threat from climate change.

Is azoospermia the appropriate standard for post-vasectomy semen analysis? Or an unachievable goal of best practice laboratory guidelines

The increasingly stringent laboratory-approach to diagnosing azoospermia for post-vasectomy semen analysis (PVSA) continues to be at odds with the simpler approach desired by clinicians. This study describes the analysis of 10 years of PVSA and discusses the outcome in relation to risk, cost and assesses whether more stringent procedures are required. PVSA was performed on 4788 patients initially using a 2-test strategy (16 and 20 weeks post-surgery), moving to 1 test during 2013–2014. Azoospermia was confirmed by the analysis of 10 µl of semen followed by 10 µl of centrifuged pellet. In total, there were 9260 tests with a median of 1.93 tests/patient and 18.7 weeks to clearance. Surgical failure occurred in 1.75%, falling to 1.1% between 2011 and 2016. There were no cases of unwanted pregnancy, recanalization or complaints although misdiagnosis was detected in 1 case as a result of failure to confirm patient identification. Azoospermia performed according to World Health Organization (WHO) guidelines is sufficiently robust to confirm success/failure of vasectomy. With uncertainty surrounding the diagnosis, efforts to improve detection of occasional non-motile sperm are futile, cost more and fail to reduce risk of inappropriate clearance. Misdiagnosis is more likely from patient identification error and mitigation may include reverting to the safety net of a 2-test strategy.

The evolution and patterning of male gametophyte development.

The reproductive adaptations of land plants have played a key role in their terrestrial colonization and radiation. This encompasses mechanisms used for the production, dispersal and union of gametes to support sexual reproduction. The production of small motile male gametes and larger immotile female gametes (oogamy) in specialized multicellular gametangia evolved in the charophyte algae, the closest extant relatives of land plants. Reliance on water and motile male gametes for sexual reproduction was retained by bryophytes and basal vascular plants, but was overcome in seed plants by the dispersal of pollen and the guided delivery of non-motile sperm to the female gametes. Here we discuss the evolutionary history of male gametogenesis in streptophytes (green plants) and the underlying developmental biology, including recent advances in bryophyte and angiosperm models. We conclude with a perspective on research trends that promise to deliver a deeper understanding of the evolutionary and developmental mechanisms of male gametogenesis in plants.

The case for early post-vasectomy semen analysis combining small non-motile sperm and azoospermia

Background: Post-vasectomy semen analysis timing and criteria guidelines have evolved over time. Through analysis of our unit’s practice of post-vasectomy semen analysis from earlier sampling protocols at 8 weeks to single sampling at 12 weeks then 16 weeks, the impact on success rates and patient compliance were assessed. In addition, the use of small numbers of non-motile sperm and azoospermia combined rates as a marker of sterility were examined. Methods: All patients who underwent vasectomy in 2011 (8 and 12-week samples), 2013 (12-week samples) and 2016 (16-week samples) were included. Patients were given written and verbal instructions explaining the sample delivery protocol and samples. χ2 Testing was used to compare patient compliance and the results of post-vasectomy semen analysis with significance set at P&lt;0.05. Results: In total 1124 vasectomies were performed, with 21% ( N=232) of patients non-compliant with submitting samples at the requested time period. Azoospermia rates increased with a longer time to post-vasectomy semen analysis from 82% to 95%, P&lt;0.001; however, declining compliance meant the proportion of patients given clearance remained the same (70% vs. 68%, P=0.32). Rates of small non-motile sperm declined over an increasing time to post-vasectomy semen analysis. Therefore combined azoospermia and small non-motile sperm rates remained stable over an increasing sampling time (95% vs. 99%, P=0.39). Conclusion: The use of earlier post-vasectomy semen analysis is recommended as patient compliance decreases with the time from vasectomy. When azoospermia and small non-motile sperm rates are combined the rates of success of the procedure remain the same over time therefore earlier testing at 8 weeks is feasible without compromising clearance rates. Level of evidence: Not applicable for this single centre audit.

Vitamin E attenuates nicotine- and noise-induced reproductive impairment in male albino Wistar rats.

Previous studies showed that exposure to stress or nicotine induced reproductive impairment in male rats. Here, we assessed the effect of an antioxidant (vitamin E) on nicotine-, stress- and nicotine + stress-induced reproductive impairment in male rats. Forty-eight male albino Wistar rats were divided into eight groups as follows; control, stress (generator noise 90-120dB, 8hr/day), nicotine (1.5mg kg-1 day-1 ), nicotine + stress, vitamin E (100mg kg-1 day-1 ), stress + vitamin E, nicotine + vitamin E and stress + nicotine + vitamin E. Sperm count, viability, motility and rapid progressive forward movement decreased significantly (p<0.05), while percentage of nonmotile spermatozoa increased significantly (p<0.05) in stress, nicotine and nicotine + stress groups, compared with control. Serum testosterone and follicle-stimulating hormone decreased significantly (p<0.05) in stress, nicotine and nicotine + stress groups, compared with control. Serum luteinising hormone decreased (p<0.05) significantly in stress and nicotine + stress groups, compared with the control. Histology of the testes showed loss of germ cells in numerous seminiferous tubules, and epididymal histology showed decreased sperm density in stress, nicotine and nicotine + stress groups compared with the control. These negative changes were more severe in the nicotine + stress group. Vitamin E ameliorated the negative changes in the above parameters. This may be attributable to its antioxidant property.

Modulatory effect of 900 MHz radiation on biochemical and reproductive parameters in rats.

In the present study, the effect of 900 MHz radiation exposure on blood biochemical and reproductive parameters was evaluated in adolescent rats. Male albino Wistar rats (8-10 weeks of age) were exposed to 900 MHz radiation (1hr/day, power density - 146.60 µW/cm2) from a mobile phone for 28 days. On 29th day the animals were euthanized and malondialdehyde (MDA), total antioxidants (TA) levels and Glutathione-S transferase (GST) activity were studied in the blood. Reproductive parameters such as total sperm count, percentage of non-motile sperms, and sperm morphology were determined. Testes sections were stained with H(et)E staining and their cellular integrity was evaluated. Caspase-3 activity in the testes was also determined. MDA concentration was increased but TA levels and GST activity were not found to be different in 900 MHz group compared to controls. Sperm motility was found to be slightly reduced in 900 MHz group. Percentage of abnormal sperm was significantly elevated in 900 MHz group. Additionally, loss of germ cells particularly spermatocytes and spermatids was found in the testes of 900 MHz group. Testes caspase-3 activity was slightly elevated in 900 MHz exposed rats. Chronic 900 MHz exposure induced oxidative damage in the blood and lead to alterations in reproductive parameters in rats (Fig. 4, Ref. 33).

Outer dense fibers stabilize the axoneme to maintain sperm motility.

Outer dense fibers (ODFs), as unique accessory structures in mammalian sperm, are considered to play a role in the protection of the sperm tail against shear forces. However, the role and relevant mechanisms of ODFs in modulating sperm motility and its pathological involvement in asthenozoospermia were unknown. Here, we found that the percentage of ODF defects was higher in asthenozoospermic samples than that in control samples and was significantly correlated with the percentage of axoneme defects and non‐motile sperm. Furthermore, the expression levels of ODF major components (Odf1, 2, 3, 4) were frequently down‐regulated in asthenozoospermic samples. Intriguingly, the positive relationship between ODF size and sperm motility existed across species. The conditional disruption of Odf2 expression in mice led to reduced sperm motility and the characteristics of asthenozoospermia. Meanwhile, the expression of acetylated α‐tubulin was decreased in sperm from both Odf2 conditional knockout (cKO) mice and asthenozoospermic men. Immunofluorescence and biochemistry analyses showed that Odf2 could bind to acetylated α‐tubulin and protect the acetylation level of α‐tubulin in HEK293T cells in a cold environment. Finally, we found that lithium elevated the expression levels of Odf family proteins and acetylated α‐tubulin, elongated the midpiece length and increased the percentage of rapidly moving sperm in mice. Our results demonstrate that ODFs are beneficial for sperm motility via stabilization of the axoneme and that hypo‐expression of Odf family proteins is involved in the pathogenesis of asthenozoospermia. The lithium administration assay will provide valuable insights into the development of new treatments for asthenozoospermia.

Separation of sperm cells from samples containing high concentrations of white blood cells using a spiral channel.

Microfluidic technology has potential to separate sperm cells from unwanted debris while improving the effectiveness of assisted reproductive technologies (ART). Current clinical protocol limitations regarding the separation of sperm cells from other cells/cellular debris can lead to low sperm recovery when the sample contains a low concentration of mostly low motility sperm cells and a high concentration of unwanted cells/cellular debris, such as in semen samples from patients with pyospermia [high white blood cell (WBC) semen]. This study demonstrates label-free separation of sperm cells from such semen samples using inertial microfluidics. The approach does not require any externally applied forces except the movement of the fluid sample through the instrument. Using this approach, it was possible to recover not only any motile sperm, but also viable less-motile and non-motile sperm cells with high recovery rates. Our results demonstrate the ability of inertial microfluidics to significantly reduce WBC concentration by flow focusing of target WBCs within a spiral channel flow. The estimated sample process time was more rapid (∼5 min) and autonomous than the conventional method (gradient centrifuge sperm wash; ∼1 h). A mixture of sperm/WBC was injected as the device input and 83% of sperm cells and 93% of WBCs were collected separately from two distinct outlets. The results show promise for enhancing sperm samples through inertial flow processing of WBCs and sperm cells that can provide an advantage to ART procedures such as sample preparation for intrauterine insemination.

Glyphosate, Chronic Toxicity on Male Reproductive Indices and The Role of Zinc Supplementation in Wistar Rats

1. Abstract Sixty-four adult male Wistar rats were used. They were randomized into eight (8) groups viz: Group I administered distilled water (2 ml/kg), group II, administered zinc (50 mg/kg), group IIIadministeredglyphosate (14.4 mg/kg), group IV,administered glyphosate (375 mg/kg), group V administered glyphosate (750 mg/kg), group VIpretreated with zinc (50 mg/kg) for an hour then glyphosate administered (14.4 mg/kg), group VII, pretreated with zinc (50 mg/kg) for an hour then glyphosate administered(375 mg/kg) and group VIII, pretreated with zinc (100 mg/kg) for an hour then glyphosate administered(750 mg/kg). The experiment lasted for 36 weeks. At the end, blood samples from four rats in each group were collected after chloroform anesthesia and used for serum hormonal assays and samples of testes were taken for seminal and sialic acid analyses. Semen characteristics showed relative decreases in sperm concentration, live sperm concentration, sperm motility, progressive sperm motility and significant decrease in normal sperm morphology. Sperm tail abnormality, dead sperm and non-motile sperm motility relatively increased and significant increases were recorded in abnormal sperm morphology and non-progressive sperm motility and variable changes were obtained in mid-piece abnormality; decreased sialic acid concentration was recorded. Relative decrease in serum testosterone and marginal increases in serum luteinizing and follicle stimulating hormone were recorded. Fat vacuoles in the seminiferous tubules, degeneration of the spermatogenic cells, abnormal spermatids were recorded. It was concluded that the changes sequel to chronic glyphosate exposure in male Westar rats in this study were ameliorated with zinc. 2. Keywords: Chronic; Glyphosate; Reproductive Indices;Zinc

MP89-17 MICROSCOPIC EVALUATION OF THE VASAL FLUID FOR SPERM AT THE TIME OF VASECTOMY REVERSAL – DO WE REALLY NEED TO CHECK?

You have accessJournal of UrologyInfertility: Therapy I1 Apr 2017MP89-17 MICROSCOPIC EVALUATION OF THE VASAL FLUID FOR SPERM AT THE TIME OF VASECTOMY REVERSAL – DO WE REALLY NEED TO CHECK? Ethan Grober and Sammi Tobe Ethan GroberEthan Grober More articles by this author and Sammi TobeSammi Tobe More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.2815AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES During vasectomy reversal (VR), intra-operative microscopic evaluation of the vasal fluid for sperm presence and quality can inform of the possibility of epididymal obstruction and need for a vasoepididymostomy (VE). Despite its potential utility, the practice of intra-operative microscopic vas fluid evaluation is not universal. Some centers may not have bench microscopy available. Some surgeons may only perform vasovasostomy (VV) and therefore are not influenced by vasal fluid characteristics or alternatively feel that the vasal fluid quality alone can predict the need for a VE. Objective: In an effort to validate the utility of microscopic vasal fluid evaluation, the current initiative correlates vasal fluid characteristics with sperm presence and quality in a large series of VRs. METHODS 1108 bilateral vasectomy reversals performed by a single surgeon (EG) yielded a total of 2216 vasal units (right & left sides) for analysis. During VR, vasal fluid was expressed and sampled from the transected testicular end vas and the fluid was characterized (thick-paste/opaque/translucent/clear). The volume of vasal fluid was documented (copious/minimal). Each aspirated sample underwent microscopic evaluation for sperm quality and categorized as: motile sperm/intact non-motile sperm/sperm parts/no sperm. The predictive utility of the gross vasal fluid characteristics with respect to sperm presence and quality was analyzed. RESULTS Table 1 summarizes the relationship between the gross vasal fluid characteristics and the microscopic presence and quality of sperm within the fluid among 2216 vasal units. When thick-pasty fluid was observed, no sperm were seen in the samples in 50% of cases and if present, only non-motile sperm were observed. Importantly, even in the setting of more favorable vasal fluid characteristics (clear, translucent & opaque fluid), no sperm were seen in 7-11% of cases, suggesting the possibility of epididymal obstruction and the need for a VE. CONCLUSIONS Intra-operative microscopic evaluation of the vasal fluid for sperm is a necessary practice during vasectomy reversal to optimize surgical outcomes. The gross characteristics of the vasal fluid alone does not universally predict sperm presence and quality. Reliance on vasal fluid characteristics in isolation, without microscopic sperm analysis, may lead to unrecognized epididymal obstruction and the possible need for a VE in approximately 10% of cases of VR. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e1208 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Ethan Grober More articles by this author Sammi Tobe More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

56 THE VIABILITY AND LONGEVITY OF OGYE CHICKEN FROZEN SEMEN WITH MITOTEMPOL, MITOCHONDRIA-SPECIFIC ANTIOXIDANT

Semen from Korean Native Black roosters (Ogye) was cryopreserved with 8% N-Methylacetamide (MA) in HS-1 diluent, of the following composition (per 100 mL): glucose 0.2 g, trehalose dihydrate 3.8 g, l-glutamic acid monosodium salt 1.2 g, potassium acetate 0.3 g, magnesium acetate tetrahydrate 0.08 g, potassium citrate monohydrate 0.05 g, BES 0.4 g, Bis-Tris 0.4 g, and gentamicin sulfate 0.001 g. Ogye semen was collected 2 times a week by dorsal-abdominal massage and cooled into ice slurry. During dilution, semen was diluted by 2 steps. First, HS-1 diluent that was supplemented with respective concentration of MitoTEMPOL, mitochondria-specific antioxidant was added into fresh semen with same volume. Second, after waiting for 10 min, 16% MA containing diluent was added into first diluted semen so the final concentrations of MA were adjusted to 8%. The concentration of the MitoTEMPOL of first diluent was adjusted to 0.1, 1, 5, and 10 μM. After freezing for 30 min by exposure to liquid nitrogen vapor 4 cm above the surface of liquid nitrogen, the semen was thawed 5°C for 2 min 1 to 3 weeks later. The viability and longevity of thawed Ogye semen were analysed by sperm movement methods. Briefly, 5 μL of thawed semen was placed onto a Makler chamber and the movement of spermatozoa was recorded for 10 s by digital camera and saved as movie files on the computer. With digital rewinding for 1 s of saved movies, the non-motile and motile sperm was counted using a manual counter. The resulting numbers of respective spermatozoa were analysed by Student t-test. The 0.1 and 1 μM treated semen showed significant increases in viability compared with control, 5 μM and 10 μM MitoTempol (77.3 and 84.2% v. 65.4, 53.2, and 21.5%; P &lt; 0.05). The longevity of frozen/thawed Ogye semen for 3 h was also higher in 0.1 and 1 μM treated groups than control, 5 μM, and 10 μM (67.5 and 54.2% v. 36, 5.2, and 1.2%; P &lt; 0.05). With these results, utilisation of mitochondria-specific antioxidant for freezing of Ogye spermatozoa could increase the viability and longevity of frozen-thawed semen. However, treatment with concentrations &gt;1 μM showed negative effects on freezing of Ogye chicken semen. These findings could be helpful for cryobanking of rooster semen for preservation of selected breeders from malignant viral avian disease.

Structure-Activity Relation of AMOR Sugar Molecule That Activates Pollen-Tubes for Ovular Guidance.

Successful fertilization in flowering plants depends on the precise directional growth control of pollen tube through the female pistil tissue toward the female gametophyte contained in the ovule for delivery of nonmotile sperm cells. Cys-rich peptides LUREs secreted from the synergid cells on either side of the egg cell act as ovular attractants of pollen tubes. Competency control by the pistil is crucial for the response of pollen tubes to these ovular attractants. We recently reported that ovular 4-O-methyl-glucuronosyl arabinogalactan (AMOR) induces competency of the pollen tube to respond to ovular attractant LURE peptides in Torenia fournieri. The beta isomer of the terminal disaccharide 4-O-methyl-glucuronosyl galactose was essential and sufficient for the competency induction. However, critical and noncritical structures in the disaccharide have not been dissected deeply. Herein, we report the synthesis of new AMOR analogs and the structure-activity relationships for AMOR activity in the presence of these synthesized analogs. Removal of 4-O-methyl group or -COOH from the glucuronosyl residue of the disaccharide dramatically reduces AMOR activity. The pyranose backbone of the second sugar of disaccharide is essential for the activity but not hydroxy groups. The role of beta isomer of the disaccharide 4-Me-GlcA-β(1,6)-Gal is very specific for competency control, as there was no difference in effect among the sugar analogs tested for pollen germination. This study represents the first structure-activity relationship study, to our knowledge, of a sugar molecule involved in plant reproduction, which opens a way for modification of the molecule without loss of activity.

Effect of Lifestyle Factors on Semen Quality

Effect of Lifestyle Factors on Semen Quality

2016 Laboratory guidelines for postvasectomy semen analysis: Association of Biomedical Andrologists, the British Andrology Society and the British Association of Urological Surgeons

Post-vasectomy semen analysis (PVSA) is the procedure used to establish whether sperm are present in the semen following a vasectomy. PVSA is presently carried out by a wide variety of...

Optimizing outcomes in vasectomy: how to ensure sterility and prevent complications

Vasectomy provides a long-term effective sterilization for men and is performed on nearly 500,000 men annually in the United States. Improvements in technique have led to a decreased failure rate and fewer complications, although significant variations in technique exist. Use of cautery occlusion with or without fascial interposition appears to have the least failures. A no-scalpel approach lowers risk of hematoma formation, infection and bleeding post-operatively. A patient can be considered sterile when azoospermia is achieved or the semen analysis shows less than 100,000 non-motile sperm per milliliter. Incorporating these principles may allow the physician to optimize outcomes in vasectomy.