Oxidative stress (OS) occurs with an overabundance of reactive oxygen species (ROS) generation an... more Oxidative stress (OS) occurs with an overabundance of reactive oxygen species (ROS) generation and the inability of scavengers, i.e. antioxidants, to neutralize excessive loads of ROS. OS has a role in the etiopathologenesis of many factors causing natural infertility. Infertility is a problem of great magnitude affecting 6 million American women. The etiologies of unexplained infertility and recurrent pregnancy loss remain unclear and present a scientific challenge. Oxidative stress may be a piece in this puzzle. Although investigation of the exact mechanisms by which OS causes pathological processes affecting female fertility is ongoing, research has clearly shown that the redox state affects gametes, their interactions, and the resultant embryo. OS has adverse effects on assisted fertility including IVF/ICSI and in-vitro maturation. This article addresses the role of OS in female infertility, the effect it has on assisted reproductive techniques, and OS prevention strategies including the use of in-vivo and in-vitro antioxidant supplementation.
Preeclampsia is a complex multisystem disorder exclusively seen in human species that is characte... more Preeclampsia is a complex multisystem disorder exclusively seen in human species that is characterized by hypertension and proteinuria. This disorder has the highest maternal and fetal morbidity and mortality of all pregnancy-related complications. Growing evidence suggests that placental oxidative stress is involved in the etiopathogenesis of preeclampsia. Reduced perfusion as a result of abnormal placentation leads to ischemia reperfusion injury to the placenta. Placental oxidative stress, which results from the ischemia reperfusion injury, is being increasingly reported to be involved in the etiopathogenesis of preeclampsia. It has been proposed as a promoter of lipid peroxidation and the endothelial cell dysfunction that is commonly seen in this condition. Although preeclampsia is characterized by increased lipid peroxidation and diminished antioxidant capacity, there is no consensus regarding causality of lipid peroxidation in preeclampsia. In this article, we address the question of the biologic association of lipid peroxidation and preeclampsia. Lipid peroxidation and leukocyte activation may play a pivotal role in endothelial cell dysfunction. We also review the different factors that have been proposed to cause endothelial cell dysfunction in preeclampsia, trials investigating the role of antioxidant supplementation in preeclampsia, and the lack of consensus among the trials. Additional longitudinal studies are necessary to determine if the various oxidative stress biomarkers estimated early in pregnancy can be narrowed to a single marker for predicting preeclampsia.
The effects of ovarian endometrioma on fertility outcomes with IVF and embryo transfer have been ... more The effects of ovarian endometrioma on fertility outcomes with IVF and embryo transfer have been causally related to poor outcomes. The objective of this meta-analysis was to evaluate the ovarian reserve and ovarian responsiveness to ovarian stimulation and assisted reproduction outcomes in patients with ovarian endometrioma. The odds for clinical pregnancy were not affected signifi cantly in patients with ovarian endometrioma compared with controls, with an overall odds ratio of 1.07 from three studies [95% CI: (0.63, 1.81), P = 0.79]. The overall pregnancy rate was similar with an estimated odds ratio of 1.17 [95% CI: (0.85, 1.60), P = 0.34]. Decreased ovarian responsiveness to ovarian stimulation in patients with ovarian endometrioma may be due to a reduced number of follicles in these patients compared with controls (P = 0.002). Prospective randomized controlled trials are needed to assess whether surgical treatment versus no surgical treatment improves pregnancy outcomes in patients with ovarian endometrioma undergoing assisted reproduction cycles.
Human reproduction is not considered a highly efficient biological process. Before the end of the... more Human reproduction is not considered a highly efficient biological process. Before the end of the first trimester, 30%-50% of conceptions end in spontaneous abortion. Most losses occur at the time of implantation. 15%-20% of clinical pregnancies end in spontaneous abortions. Recurrent pregnancy loss is a frustrating clinical problem both for clinicians and patients. Recurrent pregnancy loss affects 0.5%-3% of women in the reproductive age group, and between 50%-60% of recurrent pregnancy losses are idiopathic. Oxidative stress-induced damage has been hypothesized to play a role in spontaneous abortion, idiopathic recurrent pregnancy loss, hydatidiform mole, defective embryogenesis, and drug-induced teratogenicity. Some studies implicate systemic and placental oxidative stress in the pathophysiology of abortion and recurrent pregnancy loss. Oxidant-induced endothelial damage, impaired placental vascularization and immune malfunction have all been proposed to play a role in the pathophysiology of idiopathic recurrent pregnancy loss. Oxidative stress-induced placental dysfunction may be a common cause of the multifactorial and polygenic etiologies of abortion, recurrent pregnancy loss, defective embryogenesis, hydatidiform mole, and drug-induced teratogenic effects. Oxidative stress-induced modification of phospholipids has been linked to the formation of antiphospholipid antibodies in the antiphospholipid syndrome. The objective of this review was to examine the association between oxidative stress, spontaneous abortion and recurrent pregnancy loss, based on the published literature. We conducted an extensive literature search utilizing the databases of Medline, CINAHL, and Cochrane from 1986 to 2005. The following keywords were used: oxidative stress, abortion, recurrent pregnancy loss, reactive oxygen species, antioxidants, fetal development, and embryopathies. We conducted an electronic search, as well as a manual search of cross-references. We have included all studies in the English language found in the literature focusing on oxidative stress and its association with abortions, recurrent pregnancy loss and drug-induced teratogenicity. The role of antioxidant vitamins for primary prevention of oxidative stress-induced pathologies needs to be investigated further.
To standardize the TUNEL assay by establishing inter- and intraobserver variability, interassay v... more To standardize the TUNEL assay by establishing inter- and intraobserver variability, interassay variability, cutoff values, sensitivity and specificity of the assay, and studying the distribution of the DNA damage in a population of infertile men referred to a clinical andrology laboratory.Seminal ejaculates from 25 healthy male volunteers (controls) and 194 infertile men (with male factor infertility) referred to an andrology laboratory were examined for DNA damage by TUNEL assay using flow cytometric analysis.Both the inter- and intraobserver variability and interassay variability was small (<10%). DNA damage in the controls was 11.9 ± 6.8% vs. 29.5 ± 18.7% in patients (P <.001). The cut-off value of 19.25% maximized the observed sensitivity (64.9%) and specificity (100%) of the assay. The distribution of DNA damage in the patients was as follows: 14.9% (29 of 194) with DNA damage between 0% and 10%; 22.7% (44 of 194) between 10% and 20%; 8.8% (17 of 194) between 20% and 30%; and 17.5% (34 of 194) between 30% and 40%. Finally, 27.3% (53 of 194) had TUNEL values >40%.We report a detailed standardization of the TUNEL assay for clinical use, as well as reference ranges for DNA damage in normal healthy donors and infertile men. A cut-off of 19.25% with observed 100% specificity established in our program can differentiate infertile men with DNA damage from healthy men. This test can be offered to infertile patients who are idiopathic, have severe oxidative stress-related abnormal semen quality, and contribute to the infertility problem of the couple who are considering assisted reproductive techniques.
Polycystic ovary syndrome (PCOS) is a multifactorial disorder affecting many women of reproductiv... more Polycystic ovary syndrome (PCOS) is a multifactorial disorder affecting many women of reproductive age, typically due to hyperandrogenemia, hyperinsulinemia, and enigmatic genetic factors. The complex nature of PCOS is reflected in the broad spectrum of the disorder's clinical presentation, including metabolic and reproductive disorders. As a result, while the European Society for Human Reproduction and Embryology and the American Society for Reproductive Medicine (ESHRE/ASRM) have agreed on a consensus definition of PCOS to help clinical investigators, the condition is recognized to have multiple clinical phenotypes.
Female sexual dysfunction is a prevalent problem in the general community; however, it has not be... more Female sexual dysfunction is a prevalent problem in the general community; however, it has not been studied as extensively as male sexual dysfunction. Female sexual dysfunction is a common complication after most pelvic surgeries. With the introduction of screening programs, most pelvic malignancies are detected at earlier stages and in younger patients. Sexual dysfunction is a major quality-of-life issue in these young women. Hysterectomy (simple or radical) is the most common type of pelvic surgery in women and is one of the most important causes of female sexual dysfunction. Additionally, female sexual dysfunction is an important issue after urologic (radical cystectomy) and colorectal surgeries (simple and radical proctocolectomy). Sexual dysfunction is a common problem among postmenopausal women. Modifications in the surgical technique (nerve sparing) are rapidly evolving in the field of urology and colorectal surgery, which will be soon followed by modifications in the field of gynecologic surgery. In this article we summarize the pathophysiology and classification of female sexual dysfunction, with special emphasis on the relationship between female sexual dysfunction and pelvic surgeries.
Free radicals are molecules with one or more unpaired electron(s) commonly found in seminal plasm... more Free radicals are molecules with one or more unpaired electron(s) commonly found in seminal plasma. Physiologically, free radicals control sperm maturation, capacitation and hyperactivation, the acrosome reaction, and sperm-oocyte fusion. Pathologically, free radicals induce lipid peroxidation, DNA damage and apoptosis of spermatozoa. The present review deals with both the beneficial and detrimental effects of free radicals on sperm function.
To review the mechanisms by which endometriosis may affect reproductive function.Review of the En... more To review the mechanisms by which endometriosis may affect reproductive function.Review of the English literature from 1986 to 2007 after searching Medline, EMBASE, Cochrane, and BIOSIS, as well as relevant meeting abstracts.Fertility research center and obstetrics and gynecology department in a tertiary care hospital.There is compelling evidence in the literature that endometriosis has detrimental effects on ovarian and tubal function and uterine receptivity, resulting in female infertility. The mechanisms of infertility associated with endometriosis remain controversial and include abnormal folliculogenesis, elevated oxidative stress, altered immune function, and hormonal milieu in the follicular and peritoneal environments, and reduced endometrial receptivity. These factors lead to poor oocyte quality, impaired fertilization, and implantation.Through unraveling the mechanisms by which endometriosis leads to infertility, researchers are sure to find a nonsurgical means to diagnose endometriosis, most likely through serum and peritoneal markers. Cytokines, interleukins, oxidative stress markers, and soluble cellular adhesion molecules all show potential to be used as a reliable marker for diagnosing endometriosis. After analyzing the pathogenic mechanisms of endometriosis, it seems that the future treatment of this entity may include cyclo-oxygenase-2 inhibitors, immunomodulators, or hormonal suppressive therapy to eliminate the need for surgical treatment of endometriosis.
Introduction: The present study was undertaken to evaluate the status of lipid peroxidation and a... more Introduction: The present study was undertaken to evaluate the status of lipid peroxidation and antioxidants as biomarkers in human plasma. Methods: The extent of lipid peroxidation as evidenced by the formation of thiobarbituric acid reac t ive subst a nces ( TBA R S ) a nd conjugated dienes (CD) as well as the status of the antioxidants superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx) and glutathione Stransferase (GST) in serum samples of 40 breast cancer patients in and around Coimbatore, India, were studied. Controls consisted of members of the public with no previous history of breast cancer or other cancer-related diseases. Results : The plasma samples of the breast cancer patients showed enhanced level of lipid peroxidation when compared to the corresponding controls. This was accompanied by a significant elevation in both enzymic and non-enzymic antioxidants. Conclusion: These findings indicate the significant increase in lipid peroxidation as evidenced by the level of TBARS and antioxidant status such as elevated SOD, CAT, GPx, GSH and GST in samples from breast cancer patients compared to controls. Key words : a nt ioxida nt s , brea st c a ncer, glutathione peroxidase, lipid peroxidation Singapore Med J 2008; 49(8): 640-643
Reactive oxygen species (ROS) have a role in the modulation of gamete quality and gamete interact... more Reactive oxygen species (ROS) have a role in the modulation of gamete quality and gamete interaction. Generation of ROS is inherent in spermatozoa and contaminating leukocytes. ROS influence spermatozoa, oocytes, embryos and their environment. Oxidative stress (OS) mediates peroxidative damage to the sperm membrane and induces nuclear DNA damage. ROS can modulate the fertilizing capabilities of the spermatozoa. There is extensive literature on OS and its role in male infertility and sperm DNA damage and its effects on assisted reproductive techniques. Evidence is accumulating on the role of ROS in female reproduction. Many animal and human studies have elucidated a role for ROS in oocyte development, maturation, follicular atresia, corpus luteum function and luteolysis. OS-mediated precipitation of pathologies in the female reproductive tract is similar to those involved in male infertility. OS influences the oocyte and embryo quality and thus the fertilization rates. ROS appears to play a significant role in the modulation of gamete interaction and also for successful fertilization to take place. ROS in culture media may impact post-fertilization development, i.e. cleavage rate, blastocyst yield and quality (indicators of assisted reproduction outcomes). OS is reported to affect both natural and assisted fertility. Antioxidant strategies should be able to intercept both extracellular and intracellular ROS. This review discusses the sources of ROS in media used in IVF–embryo transfer and strategies to overcome OS in oocyte in-vitro maturation, in-vitro culture and sperm preparation techniques.
Background: Preeclampsia is characterized by increased lipid peroxidation and diminished antioxid... more Background: Preeclampsia is characterized by increased lipid peroxidation and diminished antioxidant capacity; however, there is no consensus as to the extent of these conditions. Objective: To assess the association of lipid peroxidation and antioxidant status with preeclampsia quantitatively using meta-analysis.
Significantly higher levels of oxidants (malonaldehyde and nitric oxide) and reduced levels of an... more Significantly higher levels of oxidants (malonaldehyde and nitric oxide) and reduced levels of antioxidants (superoxide dismutase, glutathione peroxidase, catalase, and ascorbic acid) are seen in semen of infertile men with varicocele. Seminal oxidative stress (OS) seen in men with varicocele is associated with sperm motility and grade of varicocele. (Fertil
Recent studies demonstrated an overwhelming success in single blastocyst transfer (SBT): implanta... more Recent studies demonstrated an overwhelming success in single blastocyst transfer (SBT): implantation rates (IR) were 60.9%-70.5% and pregnancy rates (PR) were 60.9%-76% while the multiple pregnancy rates (MPR) were 0%-3.2%. Most of these studies involved good prognosis patients not more than 37 years of age. The results indicated that SBT decreased the number of multiple pregnancies while maintaining desirable pregnancy outcomes. However, SBT and cryopreserved single blastocyst transfer (cSBT) in the field of in vitro fertilization (IVF) are still in their infancy. Guidelines for the number of blastocysts being transferred and the techniques have not yet been standardized. The method to estimate the most viable blastocyst has not yet been proposed. The success of SBT also was found to be highly associated with the technique and patients' and clinicians' perceptions toward it.
Oxidative stress (OS) occurs with an overabundance of reactive oxygen species (ROS) generation an... more Oxidative stress (OS) occurs with an overabundance of reactive oxygen species (ROS) generation and the inability of scavengers, i.e. antioxidants, to neutralize excessive loads of ROS. OS has a role in the etiopathologenesis of many factors causing natural infertility. Infertility is a problem of great magnitude affecting 6 million American women. The etiologies of unexplained infertility and recurrent pregnancy loss remain unclear and present a scientific challenge. Oxidative stress may be a piece in this puzzle. Although investigation of the exact mechanisms by which OS causes pathological processes affecting female fertility is ongoing, research has clearly shown that the redox state affects gametes, their interactions, and the resultant embryo. OS has adverse effects on assisted fertility including IVF/ICSI and in-vitro maturation. This article addresses the role of OS in female infertility, the effect it has on assisted reproductive techniques, and OS prevention strategies including the use of in-vivo and in-vitro antioxidant supplementation.
Preeclampsia is a complex multisystem disorder exclusively seen in human species that is characte... more Preeclampsia is a complex multisystem disorder exclusively seen in human species that is characterized by hypertension and proteinuria. This disorder has the highest maternal and fetal morbidity and mortality of all pregnancy-related complications. Growing evidence suggests that placental oxidative stress is involved in the etiopathogenesis of preeclampsia. Reduced perfusion as a result of abnormal placentation leads to ischemia reperfusion injury to the placenta. Placental oxidative stress, which results from the ischemia reperfusion injury, is being increasingly reported to be involved in the etiopathogenesis of preeclampsia. It has been proposed as a promoter of lipid peroxidation and the endothelial cell dysfunction that is commonly seen in this condition. Although preeclampsia is characterized by increased lipid peroxidation and diminished antioxidant capacity, there is no consensus regarding causality of lipid peroxidation in preeclampsia. In this article, we address the question of the biologic association of lipid peroxidation and preeclampsia. Lipid peroxidation and leukocyte activation may play a pivotal role in endothelial cell dysfunction. We also review the different factors that have been proposed to cause endothelial cell dysfunction in preeclampsia, trials investigating the role of antioxidant supplementation in preeclampsia, and the lack of consensus among the trials. Additional longitudinal studies are necessary to determine if the various oxidative stress biomarkers estimated early in pregnancy can be narrowed to a single marker for predicting preeclampsia.
The effects of ovarian endometrioma on fertility outcomes with IVF and embryo transfer have been ... more The effects of ovarian endometrioma on fertility outcomes with IVF and embryo transfer have been causally related to poor outcomes. The objective of this meta-analysis was to evaluate the ovarian reserve and ovarian responsiveness to ovarian stimulation and assisted reproduction outcomes in patients with ovarian endometrioma. The odds for clinical pregnancy were not affected signifi cantly in patients with ovarian endometrioma compared with controls, with an overall odds ratio of 1.07 from three studies [95% CI: (0.63, 1.81), P = 0.79]. The overall pregnancy rate was similar with an estimated odds ratio of 1.17 [95% CI: (0.85, 1.60), P = 0.34]. Decreased ovarian responsiveness to ovarian stimulation in patients with ovarian endometrioma may be due to a reduced number of follicles in these patients compared with controls (P = 0.002). Prospective randomized controlled trials are needed to assess whether surgical treatment versus no surgical treatment improves pregnancy outcomes in patients with ovarian endometrioma undergoing assisted reproduction cycles.
Human reproduction is not considered a highly efficient biological process. Before the end of the... more Human reproduction is not considered a highly efficient biological process. Before the end of the first trimester, 30%-50% of conceptions end in spontaneous abortion. Most losses occur at the time of implantation. 15%-20% of clinical pregnancies end in spontaneous abortions. Recurrent pregnancy loss is a frustrating clinical problem both for clinicians and patients. Recurrent pregnancy loss affects 0.5%-3% of women in the reproductive age group, and between 50%-60% of recurrent pregnancy losses are idiopathic. Oxidative stress-induced damage has been hypothesized to play a role in spontaneous abortion, idiopathic recurrent pregnancy loss, hydatidiform mole, defective embryogenesis, and drug-induced teratogenicity. Some studies implicate systemic and placental oxidative stress in the pathophysiology of abortion and recurrent pregnancy loss. Oxidant-induced endothelial damage, impaired placental vascularization and immune malfunction have all been proposed to play a role in the pathophysiology of idiopathic recurrent pregnancy loss. Oxidative stress-induced placental dysfunction may be a common cause of the multifactorial and polygenic etiologies of abortion, recurrent pregnancy loss, defective embryogenesis, hydatidiform mole, and drug-induced teratogenic effects. Oxidative stress-induced modification of phospholipids has been linked to the formation of antiphospholipid antibodies in the antiphospholipid syndrome. The objective of this review was to examine the association between oxidative stress, spontaneous abortion and recurrent pregnancy loss, based on the published literature. We conducted an extensive literature search utilizing the databases of Medline, CINAHL, and Cochrane from 1986 to 2005. The following keywords were used: oxidative stress, abortion, recurrent pregnancy loss, reactive oxygen species, antioxidants, fetal development, and embryopathies. We conducted an electronic search, as well as a manual search of cross-references. We have included all studies in the English language found in the literature focusing on oxidative stress and its association with abortions, recurrent pregnancy loss and drug-induced teratogenicity. The role of antioxidant vitamins for primary prevention of oxidative stress-induced pathologies needs to be investigated further.
To standardize the TUNEL assay by establishing inter- and intraobserver variability, interassay v... more To standardize the TUNEL assay by establishing inter- and intraobserver variability, interassay variability, cutoff values, sensitivity and specificity of the assay, and studying the distribution of the DNA damage in a population of infertile men referred to a clinical andrology laboratory.Seminal ejaculates from 25 healthy male volunteers (controls) and 194 infertile men (with male factor infertility) referred to an andrology laboratory were examined for DNA damage by TUNEL assay using flow cytometric analysis.Both the inter- and intraobserver variability and interassay variability was small (<10%). DNA damage in the controls was 11.9 ± 6.8% vs. 29.5 ± 18.7% in patients (P <.001). The cut-off value of 19.25% maximized the observed sensitivity (64.9%) and specificity (100%) of the assay. The distribution of DNA damage in the patients was as follows: 14.9% (29 of 194) with DNA damage between 0% and 10%; 22.7% (44 of 194) between 10% and 20%; 8.8% (17 of 194) between 20% and 30%; and 17.5% (34 of 194) between 30% and 40%. Finally, 27.3% (53 of 194) had TUNEL values >40%.We report a detailed standardization of the TUNEL assay for clinical use, as well as reference ranges for DNA damage in normal healthy donors and infertile men. A cut-off of 19.25% with observed 100% specificity established in our program can differentiate infertile men with DNA damage from healthy men. This test can be offered to infertile patients who are idiopathic, have severe oxidative stress-related abnormal semen quality, and contribute to the infertility problem of the couple who are considering assisted reproductive techniques.
Polycystic ovary syndrome (PCOS) is a multifactorial disorder affecting many women of reproductiv... more Polycystic ovary syndrome (PCOS) is a multifactorial disorder affecting many women of reproductive age, typically due to hyperandrogenemia, hyperinsulinemia, and enigmatic genetic factors. The complex nature of PCOS is reflected in the broad spectrum of the disorder's clinical presentation, including metabolic and reproductive disorders. As a result, while the European Society for Human Reproduction and Embryology and the American Society for Reproductive Medicine (ESHRE/ASRM) have agreed on a consensus definition of PCOS to help clinical investigators, the condition is recognized to have multiple clinical phenotypes.
Female sexual dysfunction is a prevalent problem in the general community; however, it has not be... more Female sexual dysfunction is a prevalent problem in the general community; however, it has not been studied as extensively as male sexual dysfunction. Female sexual dysfunction is a common complication after most pelvic surgeries. With the introduction of screening programs, most pelvic malignancies are detected at earlier stages and in younger patients. Sexual dysfunction is a major quality-of-life issue in these young women. Hysterectomy (simple or radical) is the most common type of pelvic surgery in women and is one of the most important causes of female sexual dysfunction. Additionally, female sexual dysfunction is an important issue after urologic (radical cystectomy) and colorectal surgeries (simple and radical proctocolectomy). Sexual dysfunction is a common problem among postmenopausal women. Modifications in the surgical technique (nerve sparing) are rapidly evolving in the field of urology and colorectal surgery, which will be soon followed by modifications in the field of gynecologic surgery. In this article we summarize the pathophysiology and classification of female sexual dysfunction, with special emphasis on the relationship between female sexual dysfunction and pelvic surgeries.
Free radicals are molecules with one or more unpaired electron(s) commonly found in seminal plasm... more Free radicals are molecules with one or more unpaired electron(s) commonly found in seminal plasma. Physiologically, free radicals control sperm maturation, capacitation and hyperactivation, the acrosome reaction, and sperm-oocyte fusion. Pathologically, free radicals induce lipid peroxidation, DNA damage and apoptosis of spermatozoa. The present review deals with both the beneficial and detrimental effects of free radicals on sperm function.
To review the mechanisms by which endometriosis may affect reproductive function.Review of the En... more To review the mechanisms by which endometriosis may affect reproductive function.Review of the English literature from 1986 to 2007 after searching Medline, EMBASE, Cochrane, and BIOSIS, as well as relevant meeting abstracts.Fertility research center and obstetrics and gynecology department in a tertiary care hospital.There is compelling evidence in the literature that endometriosis has detrimental effects on ovarian and tubal function and uterine receptivity, resulting in female infertility. The mechanisms of infertility associated with endometriosis remain controversial and include abnormal folliculogenesis, elevated oxidative stress, altered immune function, and hormonal milieu in the follicular and peritoneal environments, and reduced endometrial receptivity. These factors lead to poor oocyte quality, impaired fertilization, and implantation.Through unraveling the mechanisms by which endometriosis leads to infertility, researchers are sure to find a nonsurgical means to diagnose endometriosis, most likely through serum and peritoneal markers. Cytokines, interleukins, oxidative stress markers, and soluble cellular adhesion molecules all show potential to be used as a reliable marker for diagnosing endometriosis. After analyzing the pathogenic mechanisms of endometriosis, it seems that the future treatment of this entity may include cyclo-oxygenase-2 inhibitors, immunomodulators, or hormonal suppressive therapy to eliminate the need for surgical treatment of endometriosis.
Introduction: The present study was undertaken to evaluate the status of lipid peroxidation and a... more Introduction: The present study was undertaken to evaluate the status of lipid peroxidation and antioxidants as biomarkers in human plasma. Methods: The extent of lipid peroxidation as evidenced by the formation of thiobarbituric acid reac t ive subst a nces ( TBA R S ) a nd conjugated dienes (CD) as well as the status of the antioxidants superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx) and glutathione Stransferase (GST) in serum samples of 40 breast cancer patients in and around Coimbatore, India, were studied. Controls consisted of members of the public with no previous history of breast cancer or other cancer-related diseases. Results : The plasma samples of the breast cancer patients showed enhanced level of lipid peroxidation when compared to the corresponding controls. This was accompanied by a significant elevation in both enzymic and non-enzymic antioxidants. Conclusion: These findings indicate the significant increase in lipid peroxidation as evidenced by the level of TBARS and antioxidant status such as elevated SOD, CAT, GPx, GSH and GST in samples from breast cancer patients compared to controls. Key words : a nt ioxida nt s , brea st c a ncer, glutathione peroxidase, lipid peroxidation Singapore Med J 2008; 49(8): 640-643
Reactive oxygen species (ROS) have a role in the modulation of gamete quality and gamete interact... more Reactive oxygen species (ROS) have a role in the modulation of gamete quality and gamete interaction. Generation of ROS is inherent in spermatozoa and contaminating leukocytes. ROS influence spermatozoa, oocytes, embryos and their environment. Oxidative stress (OS) mediates peroxidative damage to the sperm membrane and induces nuclear DNA damage. ROS can modulate the fertilizing capabilities of the spermatozoa. There is extensive literature on OS and its role in male infertility and sperm DNA damage and its effects on assisted reproductive techniques. Evidence is accumulating on the role of ROS in female reproduction. Many animal and human studies have elucidated a role for ROS in oocyte development, maturation, follicular atresia, corpus luteum function and luteolysis. OS-mediated precipitation of pathologies in the female reproductive tract is similar to those involved in male infertility. OS influences the oocyte and embryo quality and thus the fertilization rates. ROS appears to play a significant role in the modulation of gamete interaction and also for successful fertilization to take place. ROS in culture media may impact post-fertilization development, i.e. cleavage rate, blastocyst yield and quality (indicators of assisted reproduction outcomes). OS is reported to affect both natural and assisted fertility. Antioxidant strategies should be able to intercept both extracellular and intracellular ROS. This review discusses the sources of ROS in media used in IVF–embryo transfer and strategies to overcome OS in oocyte in-vitro maturation, in-vitro culture and sperm preparation techniques.
Background: Preeclampsia is characterized by increased lipid peroxidation and diminished antioxid... more Background: Preeclampsia is characterized by increased lipid peroxidation and diminished antioxidant capacity; however, there is no consensus as to the extent of these conditions. Objective: To assess the association of lipid peroxidation and antioxidant status with preeclampsia quantitatively using meta-analysis.
Significantly higher levels of oxidants (malonaldehyde and nitric oxide) and reduced levels of an... more Significantly higher levels of oxidants (malonaldehyde and nitric oxide) and reduced levels of antioxidants (superoxide dismutase, glutathione peroxidase, catalase, and ascorbic acid) are seen in semen of infertile men with varicocele. Seminal oxidative stress (OS) seen in men with varicocele is associated with sperm motility and grade of varicocele. (Fertil
Recent studies demonstrated an overwhelming success in single blastocyst transfer (SBT): implanta... more Recent studies demonstrated an overwhelming success in single blastocyst transfer (SBT): implantation rates (IR) were 60.9%-70.5% and pregnancy rates (PR) were 60.9%-76% while the multiple pregnancy rates (MPR) were 0%-3.2%. Most of these studies involved good prognosis patients not more than 37 years of age. The results indicated that SBT decreased the number of multiple pregnancies while maintaining desirable pregnancy outcomes. However, SBT and cryopreserved single blastocyst transfer (cSBT) in the field of in vitro fertilization (IVF) are still in their infancy. Guidelines for the number of blastocysts being transferred and the techniques have not yet been standardized. The method to estimate the most viable blastocyst has not yet been proposed. The success of SBT also was found to be highly associated with the technique and patients' and clinicians' perceptions toward it.
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