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Biomedical subjects

Tamer M Said

Publications and source records attributed to Tamer M Said.

At least 19 recordsLinked to original sources
PubMed2006

Oxidative stress in an assisted reproductive techniques setting.

OBJECTIVE: The manipulation of gametes and embryos in an in vitro environment when performing assisted reproductive techniques (ART) carries the risk of exposure of these cells to supraphysiological levels of reactive oxygen species (ROS). The main objective of this review is to provide ART personnel with all the necessary information regarding the development of oxidative stress in an ART setting, as well as the sources of ROS and the mechanisms of oxidative stress-induced damage during ART procedures. The impact of oxidative stress on ART outcome and the different strategies designed to prevent it are also discussed. DESIGN: Review of international scientific literature. A question-and-answer format was adopted in an attempt to convey comprehensive information in a simple yet focused manner. RESULT(S): The pO(2) to which gametes and the embryo are normally exposed in vivo is significantly lower than in vitro. This results in increased production of ROS. Increase in levels of ROS without a concomitant rise in antioxidant defenses leads to oxidative stress. Lipid, protein, and DNA damage have all been associated with oxidative stress. This may ultimately result in suboptimal ART success rates. CONCLUSION(S): Many modifiable conditions exist in an ART setting that may aid in reducing the toxic effects of ROS.

Embryo, Mammalian↗
PubMed2006

Role of total antioxidant capacity in the differential growth of human embryos in vitro.

OBJECTIVE: The objective of this study was to examine the relationship of early human embryonic development parameters with day 1 culture media total antioxidant levels (day 1 TAC). DESIGN: Prospective study. SETTING: Patients undergoing assisted reproduction (ART) in a teaching hospital. PATIENT(S): Patients undergoing conventional IVF (n = 153; 167 cycles) and intracytoplasmic sperm injection (ICSI; n = 105; 116 cycles) were included. Both fertilization and early cultures were performed in human tubal fluid (HTF) with 5% serum substitute supplement. INTERVENTION(S): Levels of total antioxidants in the central well (sample) and the outer well (control) of each embryo culture dish were measured. MAIN OUTCOME MEASURE(S): Fertilization rate and embryo quality at days 3 and 5 were recorded for each cycle. Age, parity, and demographic features were also compared. RESULT(S): After controlling for all demographic and clinical variables, day 1 TAC was related to fertilization rates in both groups of patients. Day 1 TAC was significantly related to high (>7) day 3 cell number, low (<10%) fragmentation rate, and blastocyst development rate in both conventional IVF and ICSI cycles. Day 1 TAC was related to pregnancy in ICSI but not conventional IVF cycles. CONCLUSION(S): Day1 TAC appears to be an important biochemical marker for early embryonic growth. Decreased embryonic fragmentation, enhanced cleavage rate, and increased blastocyst development rate may be partially related to day 1 TAC in the culture media. Whether this relationship is a cause or effect needs further assessment.

Adult↗
PubMed2006

Magnetic-activated cell sorting before cryopreservation preserves mitochondrial integrity in human spermatozoa.

Superparamagnetic annexin-V conjugated microbeads are able to eliminate spermatozoa with externalized phosphatidylserine, a membrane feature of apoptotic cells as well as spermatozoa with deteriorated plasma membrane. Our objective was to evaluate the effects of annexin-V Magnetic-Activated Cell Sorting (MACS) in cryopreservation-thawing protocols and on integrity of sperm mitochondrial transmembrane potential and mitochondrial integrity survival rate (MSR). Mature spermatozoa of 10 healthy donors were prepared by density gradient centrifugation and divided into 2 aliquots afterwards. The first one was subjected to annexin-V MACS followed by cryopreservation and thawing, while the second was cryopreserved-thawed without MACS to serve as control. Annexin-negative sperm separated by MACS showed significantly higher levels of intact mitochondria following cryopreservation-thawing (45.4+/-8.6%) compared to sperm that were not separated (15.8+/-4.6%, p<0.01). Separating a distinctive population of non-apoptotic spermatozoa with intact membranes may optimize cryopreservation-thawing outcome. MACS using annexin-V microbeads enhances the percentage of spermatozoa with intact transmembrane mitochondrial potential and mitochondrial integrity survival rates following cryopreservation.

Annexin A5↗
PubMed2006

Evaluation of sperm recovery following annexin V magnetic-activated cell sorting separation.

Magnetic-activated cell sorting (MACS) using paramagnetic annexin V-conjugated microbeads eliminates spermatozoa with externalized phosphatidylserine, which is considered one of the features of apoptosis. The objective of this study was to evaluate sperm recovery following the use of MACS as a sperm preparation technique. Mature spermatozoa were separated and divided into two fractions: the first was prepared by density gradient centrifugation (DGC) and MACS, while the second was prepared by DGC only. Following MACS, the percentage of cells collected in the annexin-negative fraction was significantly higher than the annexin-positive fraction and the sperm recovery rate was 73.8 +/- 12.1%. In conclusion, the integration of MACS with DGC can be considered as an effective sperm preparation technique that does not lead to significant cell loss. Separating a distinctive population of non-apoptotic spermatozoa with intact membranes may optimize the outcome of assisted reproduction.

Annexin A5↗
PubMed2005

Impact of sperm morphology on DNA damage caused by oxidative stress induced by beta-nicotinamide adenine dinucleotide phosphate.

OBJECTIVE: To investigate the role of DNA damage induced by beta-nicotinamide adenine dinucleotide phosphate (NADPH) in human spermatozoa. DESIGN: Prospective controlled study. SETTING: Male infertility clinic at the Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, Ohio. PATIENT(S): Twenty-eight men undergoing infertility screening. INTERVENTION(S): Chemiluminescence assay and terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling (TUNEL) assay coupled flow cytometry after incubating mature and immature sperm separated by density gradient with 5 mM NADPH for 0, 3, and 24 hours. MAIN OUTCOME MEASURE(S): Reactive oxygen species (ROS) generation (10(6) counted photons per minute/10(6) sperm) and percentage of spermatozoa with fragmented DNA. RESULT(S): Immature sperm from teratozoospermic semen samples were characterized by a statistically significant presence of cytoplasmic residues in the mid-piece when compared with mature normozoospermic samples. Increased ROS production was observed in spermatozoa rich in cytoplasmic residues that showed a statistically significant positive correlation with sperm DNA damage in a time-dependent manner. CONCLUSION(S): Immature sperm contain high nicotinamide adenine dinucleotide phosphate (NADPH) in cytoplasmic droplets, but it has not yet been clear whether abnormal sperm morphology plays any role in sperm DNA damage induced by oxidative stress. Our data support the role of NAPDH in ROS-mediated sperm DNA damage and suggest that abnormal sperm morphology combined with elevated ROS production may serve as a useful indicator of potential damage to sperm DNA.

DNA Damage↗
PubMed2005

Effects of magnetic-activated cell sorting on sperm motility and cryosurvival rates.

OBJECTIVE: To evaluate the effect of magnetic-activated cell sorting in cryopreservation-thawing protocols on sperm motility and cryosurvival rate. DESIGN: Prospective-controlled study. SETTING: Andrology department at a university-based medical institution. PATIENT(S): Ten healthy volunteer sperm donors. INTERVENTION(S): Sperm populations were separated using annexin-V magnetic-activated cell sorting before and after the cryopreservation-thawing process. MAIN OUTCOME MEASURE(S): Sperm motility and cryosurvival rate. RESULT(S): Annexin-negative sperm separated by magnetic-activated cell sorting had statistically significantly higher motility following cryopreservation-thawing than sperm that were not separated. Similarly, annexin-negative spermatozoa also had higher cryosurvival rate than sperm cryopreserved without magnetic-activated cell sorting and sperm that were annexin-positive. CONCLUSION(S): Superparamagnetic annexin V-conjugated microbeads can separate spermatozoa with externalized phosphatidylserine, which is considered one of the early features of late apoptosis. The separation of a distinctive population of nonapoptotic spermatozoa with intact membranes may optimize the cryopreservation-thawing outcome. Magnetic-activated cell sorting using annexin-V microbeads enhances sperm motility and cryosurvival rates following cryopreservation.

Cell Separation↗
PubMed2005

Phenotypic characterization of the immune and mast cell infiltrates in the human testis shows normal and abnormal spermatogenesis.

OBJECTIVE: To assess the types, distributions, and numbers of immune cell infiltrates in the testes of men with azoospermia. DESIGN: Prospective study. SETTING: University research and clinical institutes. PATIENT(S): Thirty-one men with azoospermia showing normal spermatogenesis (n = 10), germ cell maturation arrest (GA, n = 12), and Sertoli cell-only syndrome (SCO, n = 9). INTERVENTION(S): Testicular tissue biopsies. Sections were stained with routine (hematoxyline and eosin), special (Masson Trichrome, Gordon, Periodic Acid Schiff, Aldehyde Fuchsin, and Orcein stains), and immunoperoxidase stains (using monoclonal antibodies for B and T cells and CD68 macrophages). MAIN OUTCOME MEASURE(S): Serum levels of T, FSH, and LH in addition to histopathological analysis. RESULT(S): Hormonal profiles were unremarkable in all patients. Marked deposition of the reticular and collagen fibers was seen more in abnormal than normal spermatogenesis. The immune (B and T lymphocytes and CD68 macrophages) and mast cells were found in the interstitium, tubular walls, and lumens of all the testes analyzed. The differential counts of these cells (B and T lymphocytes, CD68 macrophages, and mast cells, respectively) were higher in SCO (1.66 +/- 0.46, 9.14 +/- 1.30, 2.26 +/- 1.68, 3.35 +/- 0.23) and GA (2.03 +/- 0.48, 4.70 +/- 1.00, 2.61 +/- 0.70, and 4.18 +/- 0.13) when compared with those in normal spermatogenesis (1.22 +/- 0.19, 5.41 +/- 0.58, 1.55 +/- 0.33, and 2.26 +/- 0.13). Increased cellular counts were not statistically significant for T and B cells and macrophages. However, these differences were statistically significant for mast cells. CONCLUSION(S): Abnormal spermatogenesis is associated with increased numbers of the immune and mast cells. Our findings may reflect an exaggerated immune response in these cases.

Adult↗
PubMed2005

Infliximab may reverse the toxic effects induced by tumor necrosis factor alpha in human spermatozoa: an in vitro model.

OBJECTIVE: To examine the toxic effects of tumor necrosis factor alpha (TNF-alpha) on ejaculated spermatozoa and evaluate the ability of infliximab to reverse these effects. DESIGN: Prospective controlled study. SETTING: Cleveland Clinic Foundation, Cleveland, Ohio. PATIENT(S): Thirty-one healthy sperm donors. INTERVENTION(S): Exposure of human spermatozoa to varying concentrations of TNF-alpha (100, 300, 400, 500 pg/mL, and 2.5 microg/mL) and infliximab (400 microg/mL). MAIN OUTCOME MEASURE(S): Sperm motility, functional integrity of plasma membrane, and DNA fragmentation. RESULT(S): Spermatozoa quality declined following incubation with TNF-alpha in a dose-dependent and time-dependent manner. Sperm motility and membrane integrity were higher in the samples incubated with TNF-alpha plus infliximab than in the samples treated with TNF-alpha only. These parameters improved significantly and were comparable with both controls and sperm incubated with infliximab alone. Similarly, the percentage of spermatozoa with DNA fragmentation improved significantly following incubation with TNF-alpha plus infliximab and again was comparable with both controls and sperm incubated with infliximab alone. CONCLUSION(S): Spermatozoa may be exposed to abnormal levels of TNF-alpha in the male reproductive tract or during their passage into the female reproductive tract (in cases of endometriosis). Exposing spermatozoa to pathological concentrations of TNF-alpha can result in significant loss of their functional and genomic integrity. Infliximab could potentially be used to help treat female infertility caused by endometriosis in those with elevated levels of TNF-alpha in their peritoneal fluid.

Analysis of Variance↗
PubMed2005

Caspase activation in human spermatozoa in response to physiological and pathological stimuli.

OBJECTIVE: To investigate caspase activation in response to a variety of pathological and physiological stimuli in light of the fact that current research offers no clear consensus about caspase activation pathways in spermatozoa. DESIGN: A prospective, controlled study. SETTING: Male infertility clinic, Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, Ohio. PATIENT(S): Fifteen healthy volunteers. INTERVENTION(S): Spermatozoa were exposed to [1] Fibroblast-associated (Fas) death receptor activation, [2] mitochondrial apoptosis induction using betulinic acid, [3] oxidative stress, and [4] prolonged incubation up to 3 hours without any external stimuli. MAIN OUTCOME MEASURE(S): Active caspases-1, -3, -8, and -9 were examined in human spermatozoa by flow cytometry using carboxyfluorescein derivatives. RESULT(S): Inducing Fas antibody did not result in any caspase activation. Conversely, betulinic acid significantly triggered caspase-9 and -3 activation. The application of oxidative stress and prolonged incubation (3 hours) failed to result in caspase activation. CONCLUSION(S): These results suggest that Fas has no functional relevance in mediating caspase activation in human ejaculated spermatozoa. Although spermatozoal mitochondria are highly susceptible to specific agonists of apoptosis such as betulinic acid via caspase activation, oxidative stress-induced apoptosis appears to be caspase independent.

Antineoplastic Agents, Phytogenic↗
PubMed2005

Relationship between semen quality and tobacco chewing in men undergoing infertility evaluation.

OBJECTIVE: Male fertility is affected by a variety of lifestyle habits that include tobacco use. A large population of Indian men is addicted to tobacco chewing. The objective of our study was to assess the relationship between tobacco chewing in these Indian men--who were part of an infertile couple--and their sperm characteristics. DESIGN: Retrospective study. SETTING: Private infertility clinic. PATIENT(S): Six hundred thirty-eight male patients undergoing infertility evaluations were grouped according to the frequency of their tobacco chewing habit: mild (< 3 times/day, n = 177), moderate (3-6 times/day, n = 264), and severe (> 6 times/day, n = 197). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Sperm characteristics (concentration, motility, morphology, and viability). RESULT(S): Sperm concentration, percentage motility, morphology, and percentage viability were significantly higher in the mild group vs. the moderate group and in the moderate group vs. the severe group. The percentage of men with azoospermia rose with the level of addiction (1%, 3%, and 14%) as did the percentage of men with oligoasthenoteratozoospermia (2%, 8%, and 29%), although the differences were not statistically significant. CONCLUSION(S): In our study, use of chewing tobacco by a group of Indian men who were undergoing infertility evaluation was strongly associated with a decrease in sperm quality and to a lesser extent with oligoasthenozoospermia or azoospermia. Infertile men should be counseled about the adverse effects of tobacco chewing on sperm quality.

Adolescent↗
PubMed2005

Advantage of combining magnetic cell separation with sperm preparation techniques.

The selection of vital, non-apoptotic spermatozoa is a prerequisite for achieving optimal conception rates in assisted reproductive techniques. Magnetic cell sorting using annexin-V microbeads can effectively separate apoptotic and non-apoptotic spermatozoa. The objective of the present study was to optimize the integration of magnetic cell sorting in standard sperm preparations and to correlate the effect of different sperm preparation procedures on apoptotic markers. Semen specimens collected from 15 healthy donors were prepared by either density gradient centrifugation or by one-step sperm wash technique separately and in combination with magnetic cell sorting. The preparation methods were evaluated by assessment of semen parameters (motility, viability and morphology) as well as markers of apoptosis (levels of active caspase-3, integrity of membrane mitochondrial potential and externalization of phosphatidylserine). The apoptotic markers were measured using fluorochrome dyes coupled with flow cytometry. The results showed that the combination of density gradient centrifugation and annexin-V magnetic cell sorting was superior to all other sperm preparation methods in terms of providing motile, viable and non-apoptotic spermatozoa. This study clearly shows the advantage of integrating magnetic cell sorting as a part of sperm preparation, which in turn may positively affect the success rates of assisted reproductive techniques.

Adult↗
PubMed2005

Novel association between sperm deformity index and oxidative stress-induced DNA damage in infertile male patients.

AIM: To investigate the impact of abnormal sperm morphology using the sperm deformity index (SDI) on reactive oxygen species (ROS) production and its correlation with sperm DNA damage. METHODS: Semen samples were collected from men undergoing infertility screening (n = 7) and healthy donors (n = 6). Mature spermatozoa were isolated and incubated with 5 mmol/L beta-nicotinamide adenine dinucleotide phosphate (NADPH) for up to 24 h to induce ROS. Sperm morphology was evaluated using strict Tygerberg's criteria and the SDI. ROS levels and DNA damage were assessed using chemiluminescence and terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick end labeling (TUNEL) assays, respectively. RESULTS: SDI values (median [interquartiles]) were higher in patients than donors (2 [1.8, 2.1] vs. 1.53 [1.52, 1.58], P = 0.008). Aliquots treated with NADPH showed higher ROS levels (1.22 [0.30, 1.87] vs. 0.39 [0.10, 0.57], P = 0.03) and higher incidence of DNA damage than those not treated (10 [4.69, 24.85] vs. 3.85 [2.58, 5.10], P = 0.008). Higher DNA damage was also seen following 24 h of incubation in patients compared to donors. SDI correlated with the percentage increase in sperm DNA damage following incubation for 24 h in samples treated with NADPH (r = 0.7, P = 0.008) and controls (r = 0.58, P = 0.04). CONCLUSION: SDI may be a useful tool in identifying potential infertile males with abnormal prevalence of oxidative stress (OS)-induced DNA damage. NADPH plays a role in ROS-mediated sperm DNA damage, which appears to be more evident in infertile patients with semen samples containing a high incidence of morphologically abnormal spermatozoa.

DNA Damage↗
PubMed2004

Inter-sample variability in post-thaw human spermatozoa.

Semen cryopreservation is a useful tool for preserving fertility in men who have been diagnosed with cancer and will undergo chemotherapy, radiotherapy or testicular surgery. Semen is also commonly cryopreserved prior to its use in assisted reproductive techniques such as in vitro fertilization and intracytoplasmic sperm injection. The post-thaw quality of banked sperm can vary, which may negatively affect fertilization rates. The objective of our study was to assess the pre-freeze and post-thaw variability of sperm parameters in patients who used our sperm banking services. Multiple samples obtained after a short period of sexual abstinence were examined for variation in sperm characteristics. Semen samples showed a high degree of post-thaw inter-sample variability in sperm motility, motion characteristics, and percentage cryosurvival rate compared with the pre-freeze inter-sample variability. Further research is necessary to understand the mechanism(s) responsible for this variability. This may also assist clinicians utilize semen samples with optimum semen quality in ART procedures.

Cell Survival↗
PubMed2004

Human sperm superoxide anion generation and correlation with semen quality in patients with male infertility.

OBJECTIVE: To measure levels of reactive oxygen species (ROS) including H(2)O(2) and O(2)(.-) generation in infertile men and determine whether sperm quality is correlated with levels of ROS triggered by the exogenous reduced form of beta nicotinamide adenine dinucleotide phosphate (NADPH). DESIGN: Prospective study. SETTING: Male infertility clinic at a tertiary healthcare center. PATIENT(S): Eleven infertile men and six healthy donors. INTERVENTION(S): Chemiluminescence assay using luminol and lucigenin as probes before and after incubating sperm samples with 5 mM and 10 mM of NADPH. MAIN OUTCOME MEASURE(S): The ROS generation (10(6) counted photons per minute/10(6) sperm). RESULT(S): Baseline levels of O(2)(.-) generation were significantly higher in the infertile patients than in the healthy donors (r = 0.73, 95% confidence interval [median (25th, 75th percentiles): 0.73 (0.5, 5.5) vs. 0.2 (0.0, 0.5)] when lucigenin was used as the probe. Compared with basal levels, O(2)(.-) generation was significantly higher after coincubation with NADPH (5 mM and 10 mM) in the entire combined study population, and patients only but not donors. The O(2)(.-) generation was negatively correlated with sperm concentration (r = -0.75, 95% CI 0.38-1), motility (r = -0.69, 95% CI 0.28-1), and percentage of normal morphology (r = -0.78, 95% CI 0.36-1). CONCLUSION(S): Spermatozoa from infertile men produce higher levels of O(2)(.-) in the presence of exogenous NADPH compared to healthy donors. The ability of spermatozoa to generate O(2)(.-) increases as the semen quality declines.

Acridines↗
PubMed2004

Carnitines and male infertility.

L-Carnitine (LC) and acetyl-L-carnitine (ALC) are highly concentrated in the epididymis and play a crucial role in sperm metabolism and maturation. They are related to sperm motility and have antioxidant properties. The objective of this review is to summarize the multiple roles played by LC and ALC in male reproduction, and to highlight their limitations as well as their benefits in the treatment of male infertility. A variety of studies support the conclusion that LC and/or ALC at total daily amounts of at least 3 g per day can significantly improve both sperm concentration and total sperm counts among men with astheno- or oligoasthenozoospermia. Although many clinical trials have demonstrated the beneficial effects of LC and ALC in selected cases of male infertility, the majority of these studies suffer from a lack of placebo-controlled, double blind design, making it difficult to reach a definite conclusion. Additional, well-designed studies are necessary to further validate the use of carnitines in the treatment of patients with male infertility, specifically in men with poor semen quality.

Acetylcarnitine↗
PubMed2004

Chemiluminescence technique for measuring reactive oxygen species.

Accurate assessment of reactive oxygen species (ROS) concentrations may help in the diagnosis of infertility. The chemiluminescence technique, which uses a luminometer to measure ROS, is a common method of assessment. A better understanding of the chemiluminescence technique will allow its proper application in reproductive medicine. A wide range of luminometers are available in the market, and laboratories should select the instruments that suit their individual needs.

Female↗
PubMed2004

Role of antioxidants in treatment of male infertility: an overview of the literature.

Seminal oxidative stress in the male reproductive tract is known to result in peroxidative damage of the sperm plasma membrane and loss of its DNA integrity. Normally, a balance exists between concentrations of reactive oxygen species and antioxidant scavenging systems. One of the rational strategies to counteract the oxidative stress is to increase the scavenging capacity of seminal plasma. Numerous studies have evaluated the efficacy of antioxidants in male infertility. In this review, the results of different studies conducted have been analysed, and the evidence available to date is provided. It was found that although many clinical trials have demonstrated the beneficial effects of antioxidants in selected cases of male infertility, some studies failed to demonstrate the same benefit. The majority of the studies suffer from a lack of placebo-controlled, double-blind design, making it difficult to reach a definite conclusion. In addition, investigators have used different antioxidants in different combinations and dosages for varying durations. Pregnancy, the most relevant outcome parameter of fertility, was reported in only a few studies. Most studies failed to examine the effect of antioxidants on a specific group of infertile patients with high oxidative stress. Multicentre, double-blind studies with statistically accepted sample size are still needed to provide conclusive evidence on the benefit of antioxidants as a treatment modality for patients with male infertility.

Antioxidants↗