Search PubMed⌕ Search

Biomedical subjects

Ashok Agarwal

Publications and source records attributed to Ashok Agarwal.

105 records · Page 6Linked to original sources
PubMed2002

Effect of cigarette smoking on levels of seminal oxidative stress in infertile men: a prospective study.

OBJECTIVE: To investigate levels of seminal oxidative stress (OS) and sperm quality in a group of infertile men with a history of cigarette smoking. DESIGN: A prospective clinical study. SETTING: Male infertility clinic, Urological Institute, the Cleveland Clinic Foundation, Cleveland, Ohio. PATIENT(S): Infertile men who smoked cigarettes (n = 20), infertile men who were nonsmokers (n = 32), and healthy nonsmoking donors (n = 13). INTERVENTION(S): Genital examination, standard semen analysis, sperm DNA damage. MAIN OUTCOME MEASURE(S): Levels of seminal reactive oxygen species (ROS) and total antioxidant capacity (TAC) measured by a chemiluminescence assay and seminal OS assessed by calculating a ROS-TAC score. Sperm DNA damage was measured by sperm chromatin structure assay. RESULT(S): Smoking was associated with a 48% increase in seminal leukocyte concentrations (P<.0001), a 107% increase in ROS levels (P=.001), and a 10-point decrease in ROS-TAC scores (P=.003). Differences in standard sperm variables and DNA damage indices between the infertile smokers and infertile nonsmokers were not statistically significant. CONCLUSION(S): Infertile men who smoke cigarettes have higher levels of seminal OS than infertile nonsmokers. Given the potential adverse effects of seminal OS on fertility, physicians should advise infertile men who smoke cigarettes to quit.

Analysis of Variance↗
PubMed2002

Vitamin C and vitamin E supplementation reduce oxidative stress-induced embryo toxicity and improve the blastocyst development rate.

To evaluate the adverse effects of exogenously induced reactive oxygen species (ROS) on mouse embryo development by using the 12-phorbol 13-myristate acetate (PMA)-activated leukocyte model as a source of ROS, and to examine the protective effect of antioxidant supplementation (vitamin C and vitamin E). Prospective study. Research laboratory. Effects of ROS on the blastocyst development rate in the presence and absence of antioxidant supplementation. After incubation with the PMA-activated leukocyte supernatant, the median (25th, 75th percentile) rate of blastocyst development significantly decreased from 73% (60%, 80%) after 3 hours to 30% (20%, 40%) after 6 hours compared with control reactions (86% [80%, 100%]). Co-incubating the embryos with vitamin C (50 microM) and the PMA-activated supernatant significantly increased the blastocyst development rate from 73% (60%, 80%) to 90% (80%, 91%) at 3 hours and from 30% (20%, 40%) to 91% (89%, 91%) at 6 hours-a level similar to that of control reactions. The blastocyst development rate increased after vitamin E supplementation (400 microM) at 6 hours, but not significantly and not by as much as after vitamin C supplementation. Exposure of mouse embryos to ROS for extended periods results in embryotoxicity. Vitamin C is more effective than vitamin E in reversing ROS-induced mouse embryo toxicity.

Animals↗
PubMed2002

Leukocytospermia is associated with increased reactive oxygen species production by human spermatozoa.

To investigate the role of increased seminal leukocytes in enhancing reactive oxygen species (ROS) production by human spermatozoa.A prospective study. Male infertility clinic.Forty-eight infertile men. Standard semen analysis. Assessment of sperm nuclear DNA damage by sperm chromatin structure assay. Incubation of spermatozoa from nonleukocytospermic samples with blood neutrophils. Spontaneous and phorbol 12-myristate 13-acetate (PMA)-induced ROS production in pure-sperm suspensions (after removal of leukocytes) as measured by a chemiluminescence assay. Levels of spontaneous and PMA-induced ROS production in pure-sperm suspensions from the infertile men with a diagnosis of leukocytospermia (n = 16) were significantly higher compared with the case of infertile men without leukocytospermia (n = 32) and with the case of a control group of healthy volunteers (n = 13). A similar pattern of increased ROS was observed when spermatozoa were incubated with blood neutrophils. Leukocytospermia was associated with a significant decrease in sperm motility and increase in DNA damage. Increased seminal leukocytes may play a role in stimulating ROS production by human spermatozoa. Such stimulation may be mediated via direct cell-cell contact or by soluble products released by leukocytes. Poor sperm quality in leukocytospermic samples may be due to leukocyte-mediated oxidative stress.

DNA Damage↗
PubMed2002

Role of oxidants in male infertility: rationale, significance, and treatment.

Interest in the physiologic and pathologic effects of ROS on male fertility is growing. The controlled generation of very low amounts of ROS seems to regulate the acquisition of sperm-fertilizing ability. High levels of ROS endanger sperm function and viability. Oxidative stress can arise as a consequence of excessive production of ROS or impaired antioxidant defense mechanisms in semen. Oxidative stress precipitates a range of pathologies that are thought to affect the male reproductive system. ROS-mediated peroxidative damage to the sperm plasma membrane may account for the defective sperm functions observed in a high proportion of infertility patients. High levels of ROS in semen have been correlated with reduced sperm motility and damage to sperm nuclear DNA. Determining the levels and the sources of excessive ROS production in human semen and precise evaluation of the scavenger system may be useful tools to develop therapeutic strategies for male infertility. Therapeutic interventions directed toward the isolation of mature spermatozoa by in vitro separation techniques may benefit infertile men in whom oxidative stress has a significant role. Nevertheless, this approach may be limited by the fact that the prolonged centrifugation involved in these procedures may enhance ROS production by spermatozoa. Clinical trials using antioxidants in vivo and in vitro have resulted in a major debate, and further research is required before one can be optimistic about a role for antioxidants in the treatment of infertile men. A double-blind, placebo-controlled study underway at the authors' center is evaluating the effects of treating infertile men with a combination of vitamins E and C after adjusting for all causes of controversy.

Humans↗
PubMed2002

[Utility of oxidative stress test in the male infertility clinic].

The controlled generation of very low amounts of reactive oxygen species (ROS) appears to regulate normal sperm functions, while high levels of ROS endanger sperm viability and function. Oxidative stress (OS) develops as a consequence of excessive production of ROS and/or impaired antioxidant defense system. It is proposed that such OS precipitates a range of pathologies currently thought to afflict male reproductive function. ROS-mediated peroxidative damage to the sperm plasma membrane may account for defective sperm function observed in a high proportion of infertility patients. Excessive generation of ROS may also attack integrity of DNA in the sperm nucleus. DNA bases are susceptible to oxidative stress, and peroxidation of these structures can cause base modification, DNA strand breaks and chromatin cross-linking. DNA damage induced by excessive ROS may accelerate the process of germ cell apoptosis, leading to decline in sperm counts associated with male infertility, and may explain the apparent deterioration of semen quality observed during the past four to five decades. For almost a decade, our research team in the Cleveland Clinic Foundation has identified the critical role of OS in male infertility. The main objective of our research was to transfer this important knowledge from the research bench to clinical practice. We designed studies with the aims of: 1. understanding the exact mechanisms by which OS develops in semen, which we thought will help setup strategies to overcome the problem, 2. establishing assays for accurate assessment of OS status and running the quality control studies for this purpose, 3. testing the correlation between OS and sperm nuclear DNA damage, and 4. identifying the clinical significance of seminal OS assessment in male infertility practice.

DNA↗
PubMedDate not supplied

New semen quality scores developed by principal component analysis of semen characteristics.

The purpose of this study was to determine whether semen characteristics can be reduced to 2 semen quality (SQ) scores and whether these new scores can help the clinician in assessing the reproductive outcome. A cross-sectional sample of 250 patients seeking infertility treatment were analyzed for semen characteristics. In addition, 177 male-factor patients (prostatitis with infection, n = 40; varicocele, n = 77; varicocele with infections, n = 11; and vasectomy reversal, n = 43) were also assessed. Sperm motion kinetics were measured by computer-assisted semen analysis (CASA) (concentration, percent motility, curvilinear velocity [VCL], straight-line velocity [VSL], average path velocity [VAP], linearity [LIN], and amplitude of lateral head displacement [ALH]). Sperm morphology was assessed by both World Health Organization (WHO) guidelines and Tygerberg strict criteria. The principal component analysis model was used to construct an SQ score and a relative semen quality (RQ) score. A separate set of 25 normal donors was included as controls to determine normal ranges of the semen scores. Among the patient samples, SQ and RQ scores (median and 25% and 75% interquartile values) were 89.9, 25.1, and 130.4 and 106.1, 45.2, and 165.9, respectively. The SQ score for the varicocele and varicocele with infection groups was comparable (78.6 +/- 17.4 and 84.8 +/- 20.6) but significantly different from the control (100 +/- 10, P <.001 and.03). Vasectomy reversal patients had an SQ score of 78.2 plus or minus 16.8 that was significantly lower than controls (P <.001). The correlation among semen characteristics allows for the efficient combining of semen measures. The composite scores can summarize overall SQ and quantity. Both SQ and RQ scores provide meaningful information on the quality of semen specimens for the clinician.

Humans↗
PubMedDate not supplied

The use of novel semen quality scores to predict pregnancy in couples with male-factor infertility undergoing intrauterine insemination.

The purpose of this study was to determine whether 2 new semen quality (SQ) scores could predict pregnancy in patients undergoing intrauterine insemination (IUI) for male-factor infertility and whether an overall score could help in counseling these couples with assisted reproductive technique (ART) options. Ninety-three couples with male-factor infertility were examined for semen analysis. Samples were prepared by density gradient separation (47% and 90%), and IUI was performed. On the basis of the 2 semen scores (SQ and relative quality [RQ]), the IUI-semen pregnancy score (IUI-SPS) was calculated. Of the 192 IUI cycles, 14% (27 of 192) resulted in pregnancy. Both prewash SQ and RQ scores were significantly related to pregnancy (P =.02 and P <.001), as was the postwash RQ score (P <.001). Of the IUI cycles in which the postwash RQ score was greater than 125, 40% (13 of 32) resulted in pregnancy compared to 9% of cycles (14 of 160) in which the postwash SQ score was less than 125. The prewash IUI-SPS score was significantly related to IUI-induced pregnancy (P <.001). Both the pre- and postwash SQ and RQ scores can predict pregnancy in male infertility patients undergoing IUI. Patients with an IUI-SPS less than 150 may be advised to seek in vitro fertilization (IVF), whereas those with an IUI-SPS greater than 150 may be advised to seek IUI.

Female↗
PubMedDate not supplied

Enhanced chemiluminescence assay vs colorimetric assay for measurement of the total antioxidant capacity of human seminal plasma.

Although the enhanced chemiluminescence assay is commonly used to measure the nonenzymatic total antioxidant capacity (TAC) of the human seminal plasma, it is cumbersome, expensive, and time-consuming. We describe herein an alternate method to measure TAC that is based on the ability of antioxidants in seminal plasma to interfere with a reaction between 2,2'-azino-di-[3-ethylbenzthiazoline sulphonate] and metmyoglobin with H(2)O(2). This reaction produces a relatively stable blue-green color with absorbance maxima at 600 nm. We compared this colorimetric assay with our established chemiluminescence method and assessed quality control parameters (ie, intra-assay and interassay variabilities) in addition to intraobserver and interobserver differences. Our results show that the colorimetric assay was fairly predictive of antioxidant capacity similar to the chemiluminescence assay (P <.001). Furthermore, there was a high level of agreement between the duplicate measures by the same observer (intraobserver) and intra-assay variability, with a concordance correlation coefficient of 0.99. The interassay coefficient of variation was 4.7% (overall). The mean +/- SD of the difference between the 2 observers was 2.98% +/- 4.1%. In conclusion, we found that the colorimetric assay is a reliable and accurate method to evaluate seminal TAC, and it could be used as a simpler, rapid, and cheaper alternative to the chemiluminescence assay.

Antioxidants↗
PubMedDate not supplied

Utility of the nitroblue tetrazolium reduction test for assessment of reactive oxygen species production by seminal leukocytes and spermatozoa.

The purpose of this study was to evaluate the ability of spermatozoa and leukocytes in semen to produce reactive oxygen species (ROS) by using nitroblue tetrazolium (NBT) staining and to examine the association between NBT staining and levels of ROS as measured by chemiluminescence. Twenty-one infertility patients (leukocytospermia; n = 8; nonleukocytospermia, n = 13) and 9 healthy donors were included. Standard semen analysis and density gradient centrifugation were performed to test NBT staining, ROS, and total antioxidant capacity. A ROS-total antioxidant capacity (ROS-TAC) score was calculated by using principal component analysis. In the leukocytospermic group, after separation on a density gradient, the percentage of NBT-positive staining was significantly higher in sperm suspensions contaminated with leukocytes (median [25th, 75th percentiles]; 70% [61%, 79%]) compared to the nonleukocytospermic group (14.5% [9%, 25.5%]; P =.03) and donors (7% [3%, 11%]; P =.02), respectively. A strong positive correlation was seen between levels of ROS in whole ejaculates and NBT-positive staining in leukocytes (r = 0.59; P <.0006) and in leukocyte fractions (r = 0.72; P <.0001) after density gradient separation. Similarly, ROS was positively correlated with excessive cytoplasmic retention in spermatozoa from whole ejaculates and abnormal spermatozoa after separation on density gradients (r = 0.72; P <.0001). The ROS-TAC score was inversely correlated with NBT staining in leukocytes in whole ejaculates (r = -0.960, P <.0007) and in both leukocyte fractions (r = -0.39; P <.04) and spermatozoa with cytoplasmic retention (r = -0.38; P <.04). Our results indicate that the NBT reduction test can be used to assess the contribution of seminal leukocytes and defective spermatozoa towards ROS generation in semen. Levels of ROS assessed by chemiluminescence assay are strongly correlated with the results of NBT staining.

Antioxidants↗
PubMedDate not supplied

Sperm cryopreservation for men with nonmalignant, systemic diseases: a descriptive study.

Cytotoxic drugs and immunosuppressive therapies are used to treat patients with nonmalignant, nontesticular systemic diseases. These therapies can permanently suppress spermatogenesis. Sperm cryopreservation before treatment theoretically could give these men the opportunity to achieve a pregnancy with a woman later in life when the couple decides to do so. However, it is not known whether pretreatment sperm quality in these men is good enough to be used for assisted reproductive techniques. The main objective of this study was to determine the usefulness of cryopreservation in this patient population by: 1) assessing their pretreatment semen quality (eg, count, motility, and motion kinetics) and comparing it with that of healthy donors before and after cryopreservation; 2) comparing patients' pretreatment semen characteristics with World Health Organization reference values for normal sperm; and 3) examining the differences in semen parameters among patient groups. Semen specimens were obtained from 25 healthy donors and from 23 patients with a variety of disorders (12 had autoimmune disorders, 4 had kidney disorders, 3 had diabetes, 2 had ulcerative colitis, and 2 had heart transplants). All patients, except those with diabetes, required immunosuppressive or cytotoxic therapy. Although the pretreatment quality of the semen of these patients was not as good as that of donors, semen samples were within the normal reference range of the World Health Organization. No statistically significant differences in sperm parameters were found within the 4 patient groups except for those with diabetes (n = 3), who showed poorer sperm counts (P < .04). However, no conclusive evidence can be reached due to the small sample size. Our results indicate that pretreatment semen quality in these patients is adequate for reproductive techniques. We believe that cryopreservation should be offered to patients of reproductive age with disease or treatment regimens that may cause infertility.

Adult↗
PubMedDate not supplied

Role of caspases in male infertility.

Apoptosis is characterized by a variety of changes resulting in the recognition and phagocytosis of apoptotic cells. Caspases (cysteinyl aspartate-specific proteinases) play a central role in the regulation of apoptosis in the human seminiferous epithelium. They are expressed as inactive proenzymes and participate in a cascade triggered in response to pro-apoptotic signals. To date, 14 caspases have been implicated in the human apoptotic pathway cascade. Among these, caspase-3 is considered to be a major executioner protease. Since apoptosis is a universal suicide system in almost all cells, a close control via molecular, endocrine and physical factors establishes homeostasis of cell growth and death. The proper regulation of the caspase cascade plays an important role in sperm differentiation and testicular maturity. However, caspases have been implicated in the pathogenesis of multiple andrological pathologies such as impaired spermatogenesis, decreased sperm motility and increased levels of sperm DNA fragmentation, testicular torsion, varicocele and immunological infertility. Future research may provide a better understanding of the regulation of caspases, which may help us to manipulate the apoptotic machinery for therapeutic benefits. In this review, we summarize the consequences of caspase activation, aiming to clarify their role in the pathogenesis of male infertility.

Animals↗
PubMedDate not supplied

Combination therapy: medicated urethral system for erection enhances sexual satisfaction in sildenafil citrate failure following nerve-sparing radical prostatectomy.

The objective of our study was to assess the effectiveness of combining medicated urethral system for erection (MUSE) with sildenafil citrate in men unsatisfied with the sildenafil alone. Baseline and follow-up data from 23 patients (mean age, 62.5 +/- 5.23 years) unsatisfied with the use of the sildenafil citrate alone for the treatment of erectile dysfunction following nerve-sparing radical prostatectomy (mean use, 4 attempts/100-mg dose) was obtained. All patients started oral sildenafil citrate more than 6 months after radical prostatectomy. Combination therapy was initiated using 100 mg sildenafil citrate orally 1 hour prior to intercourse. Patients used combination therapy for a minimum of 4 attempts prior to assessment with the Sexual Health Inventory of Men (International Index for Erectile Function-5) and visual analog scale to gauge rigidity (0-100). The effect of therapy on the total International Index for Erectile Function (IIEF) score and penile rigidity score was assessed. Of the 23 patients, 4 (17%) had no improvement with the addition of medicated urethral system for erection and discontinued the drug, while 19 (83%) reported improvement with the penile rigidity and sexual satisfaction. The IIEF scores of these 19 patients showed significant improvements in each sexual domain, and the patients reported that erection was sufficient for vaginal penetration 80% of the time. Rigidity scores on a scale of 0-100 with sildenafil alone averaged 38% (23-53) for men and 46% (26-67) for their partners. With the addition of MUSE, scores increased to 76% for men and 62% for their partners. We conclude that the addition of MUSE to sildenafil improved sexual satisfaction and penile rigidity in patients unsatisfied with sildenafil alone.

Alprostadil↗
PubMedDate not supplied

Effects of temperature on sperm motion characteristics and reactive oxygen species.

OBJECTIVE: To evaluate the effect of temperature on sperm motility, sperm motion characteristics, and production of reactive oxygen species (ROS) in semen. METHODS: We collected semen samples from 12 infertile patients and 12 healthy donors and divided each sample into four aliquots just after liquefaction. One aliquot was analyzed immediately after liquefaction and the remaining three were analyzed after one hour of incubation at 4 degrees C, 25 degrees C, and 37 degrees C. Sperm motility and motion characteristics were measured by computer-assisted sperm analysis (CASA). Levels of ROS were determined in washed sperm suspensions using a chemiluminescence assay and results were expressed as x10(6) counted photons per minute (cpm)/20 million sperm/mL. RESULTS: Motility, curvilinear velocity, straight-line velocity, average path velocity, and amplitude of lateral head displacement decreased significantly from baseline values in both the patients and donors after incubation at 4 degrees C. Percentage motility was highest and ROS levels were lowest in the samples that were incubated at 37 degrees C. CONCLUSION: Based on our results, we suggest that semen samples be stored at 37 degrees C after collection and during transportation and processing.

Adult↗