Damayanthi Durairajanayagam | Universiti Teknologi Mara (original) (raw)

Papers by Damayanthi Durairajanayagam

Assisted reproductive technologies (ART) are considered as one of the primary management options ... more Assisted reproductive technologies (ART) are considered as one of the primary management options to address severe male factor infertility. The purpose of this study was to identify the research trends in the field of male infertility and ART over the past 20 years (2000‐2019) by analysing scientometric data (the number of publications per year, authors, author affiliations, journals, countries, type of documents, subject area and number of citations) retrieved using the Scopus database. We used VOS viewer software to generate a network map on international collaborations as well as a heat map of the top scientists in this field. Our results revealed a total of 2,148 publications during this period with Cleveland Clinic Foundation contributing the most (n = 69). The current scientometric analysis showed that the research trend on ART has been stable over the past two decades. Further in‐depth analysis revealed that density gradient centrifugation (46%) and intracytoplasmic sperm inj...

Male Infertility

Male infertility is a major concern among men in the reproductive age group. Conventional semen a... more Male infertility is a major concern among men in the reproductive age group. Conventional semen analysis provides fundamental information about sperm parameters but not sperm function. Analysis of the semen using advanced omic tools such as proteomics and metabolomic elucidates molecular pathways that are defective in infertile men. In this chapter, we have discussed about the use of proteomic and metabolomic platforms for profiling of the proteome and metabolome of the spermatozoa and seminal plasma. Furthermore, we have highlighted the findings of major proteomics and metabolomics studies in the infertile male. We have also placed emphasis on the proteins and metabolites present in the human semen and their potential use as biomarkers in the diagnosis and therapeutics of male infertility.

The World Journal of Men's Health

Arab Journal of Urology

To examine the potential effects of lifestyle factors on male reproductive health. Evidence of a ... more To examine the potential effects of lifestyle factors on male reproductive health. Evidence of a global decline in human sperm quality over recent decades has been accumulating. Environmental, occupational, and modifiable lifestyle factors may contribute to this decline. This review focuses on key lifestyle factors that are associated with male infertility such as smoking cigarettes, alcohol intake, use of illicit drugs, obesity, psychological stress, advanced paternal age, dietary practices, and coffee consumption. Other factors such as testicular heat stress, intense cycling training, lack of sleep and exposure to electromagnetic radiation from mobile phone use are briefly discussed. Materials and method: A comprehensive literature search was performed to identify and synthesise all relevant information, mainly from within the last decade, on the major lifestyle factors associated with male infertility and semen quality. Database searches were limited to reports published in English only. A manual search of bibliographies of the reports retrieved was conducted to identify additional relevant articles. Results: In all, 1012 articles were identified from the database search and after reviewing the titles and abstract of the reports, 104 articles met the inclusion criteria. Of these, 30 reports were excluded as the full-text could not be retrieved and the abstract did not have relevant data. The remaining 74 reports were reviewed for data on association between a particular lifestyle factor and male infertility and were included in the present review. Conclusion: The major lifestyle factors discussed in the present review are amongst the multiple potential risk factors that could impair male fertility. However,

Reproductive biology and endocrinology : RB&E, Jan 11, 2018

Reports of the increasing incidence of male infertility paired with decreasing semen quality have... more Reports of the increasing incidence of male infertility paired with decreasing semen quality have triggered studies on the effects of lifestyle and environmental factors on the male reproductive potential. There are numerous exogenous and endogenous factors that are able to induce excessive production of reactive oxygen species (ROS) beyond that of cellular antioxidant capacity, thus causing oxidative stress. In turn, oxidative stress negatively affects male reproductive functions and may induce infertility either directly or indirectly by affecting the hypothalamus-pituitary-gonadal (HPG) axis and/or disrupting its crosstalk with other hormonal axes. This review discusses the important exogenous and endogenous factors leading to the generation of ROS in different parts of the male reproductive tract. It also highlights the negative impact of oxidative stress on the regulation and cross-talk between the reproductive hormones. It further describes the mechanism of ROS-induced derange...

Lipids in health and disease, Jan 28, 2017

The scarcity of data about coping styles with a biochemical marker namely lipid profile, potentia... more The scarcity of data about coping styles with a biochemical marker namely lipid profile, potentially associated with cardiovascular risk factors is most striking among professionals working in public university. Hence, this research aimed to investigate the relationship between coping styles and lipid profile comprising total cholesterol (TC), triglyceride (TG), HDL-cholesterol (high density lipoprotein-cholesterol) and LDL-cholesterol (Low density lipoprotein-cholesterol) among this group of professionals. A cross sectional survey was conducted among staff from a tertiary education centre. Subjects were contacted to ascertain their medical history. A total of 320 subjects were interviewed and 195 subjects were eligible and subsequently recruited on a suitable date for taking blood and administration of the questionnaires. The subjects completed questionnaires pertaining to demographic details and coping styles. Pearson's correlation coefficient was used to measure the strength ...

Asian journal of andrology, Jan 29, 2015

To study the major differences in the distribution of spermatozoa proteins in infertile men with ... more To study the major differences in the distribution of spermatozoa proteins in infertile men with varicocele by comparative proteomics and validation of their level of expression. The study-specific estimates for each varicocele outcome were combined to identify the proteins involved in varicocele-associated infertility in men irrespective of stage and laterality of their clinical varicocele. Expression levels of 5 key proteins (PKAR1A, AK7, CCT6B, HSPA2, and ODF2) involved in stress response and sperm function including molecular chaperones were validated by Western blotting. Ninety-nine proteins were differentially expressed in the varicocele group. Over 87% of the DEP involved in major energy metabolism and key sperm functions were underexpressed in the varicocele group. Key protein functions affected in the varicocele group were spermatogenesis, sperm motility, and mitochondrial dysfunction, which were further validated by Western blotting, corroborating the proteomics analysis. ...

Medical Education Online, 2015

Background: The American Center for Reproductive Medicine's summer internship course in reproduct... more Background: The American Center for Reproductive Medicine's summer internship course in reproductive medicine and research at Cleveland Clinic is a rigorous, results-oriented annual program that began in 2008 to train both local and international students in the fundamentals of scientific research and writing. The foremost goal of the program is to encourage premedical and medical students to aspire toward a career as a physicianÁ scientist. The internship provides participants with an opportunity to engage in original bench research and scientific writing while developing theoretical knowledge and soft skills. This study describes selected survey responses from interns who participated in the 2014 internship program. The objective of these surveys was to elicit the interns' perspective on the internship program, its strengths and weaknesses, and to obtain insight into potential areas for improvement. Methods: Questionnaires were structured around the five fundamental aspects of the program: 1) theoretical knowledge, 2) bench research, 3) scientific writing, 4) mentorship, and 5) soft skills. In addition, an exit survey gathered information on factors that attracted the interns to the program, communication with mentors, and overall impression of the research program. Results: The opportunity to experience hands-on bench research and scientific writing, personalized mentorship, and the reputation of the institution were appreciated and ranked highly among the interns. Nearly 90% of the interns responded that the program was beneficial and well worth the time and effort invested by both interns and faculty. Conclusion: The outcomes portrayed in this study will be useful in the implementation of new programs or refinement of existing medical research training programs.

Asian Journal of Andrology, 2015

Men with varicocele may retain normal fertility or may present with infertility. Additionally, se... more Men with varicocele may retain normal fertility or may present with infertility. Additionally, semen analysis of infertile men with varicocele could result in normal or abnormal sperm parameters, the reasons of which remain unclear. 10 Varicocele repair is associated with improved semen parameters and has resulted in successful pregnancies. 11 Cases of unilateral varicocelectomy yielded significantly higher spontaneous pregnancy rates compared to bilateral varicocelectomy (49% vs 39% respectively). 12 However, varicocele repair showed greater significant improvement of semen parameters in patients with bilateral varicocelectomy compared to unilateral varicocelectomy. 12 Patients undergoing unilateral varicocelectomy may obtain sub-optimal results when a contralateral disease is present. 11 While surgical repair eliminates varicocele in the majority of the cases, its impact on infertility remains unclear. Proteomics involves the large-scale analysis of proteins, and it contributes greatly to our understanding of gene function in the postgenomic era. Proteomic studies have examined the sperm proteome in both normozoospermic and abnormal spermatozoa. 13-15 Prior studies on the human sperm or seminal plasma proteome have either compared the proteomic profiles of adult or adolescent varicocele patients respectively with those of healthy fertile males, 16-18 or investigated the sperm or seminal plasma proteome before and after varicocelectomy. 19,20 Selected proteins highlighted in these

Urology, 2015

OBJECTIVE To compare the sperm protein profile between infertile men with unilateral varicocele a... more OBJECTIVE To compare the sperm protein profile between infertile men with unilateral varicocele and infertile men with bilateral varicocele. METHODS This prospective study investigated 50 infertile patients with clinical varicocele (33 unilateral and 17 bilateral) seeking fertility workup between March 2012 and April 2014. Routine sperm parameters, reactive oxygen species, total antioxidant capacity, and sperm deoxyribonucleic acid fragmentation were assessed in their semen. Sperm protein profile was characterized only in pooled samples of 5 unilateral and 3 bilateral varicocele samples, respectively, using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and an Linear Trap Quadrupole-Orbitrap Elite hybrid mass spectrophotometer system. Differences in protein expression were analyzed using gel analysis software, followed by protein identification using mass spectroscopy analysis. Differentially expressed proteins and their abundance were quantified by comparing spectral counts, followed by bioinformatics analysis. RESULTS Unique expression of 64 proteins in the bilateral group and 31 proteins in the unilateral group was obtained. Core functions of the top protein interaction networks were post-translational modification (w122 proteins associated with acetylation), protein folding, free-radical scavenging, cell death, and survival. The top molecular and cellular functions were protein degradation, free radical scavenging, and post-translational modifications, whereas the top pathways were protein ubiquitination and mitochondrial dysfunction. Major biological pathways for the 253 differentially expressed proteins were metabolism, apoptosis, and signal transduction. CONCLUSION Functional proteomic profiling helps identify the differential processes or pathways that are affected based on the nature of varicocele (bilateral or unilateral) and provide insights into the mechanistic implications of varicocele-associated male infertility. UROLOGY 85: 580e588, 2015.

Asian Journal of Andrology, 2014

AJP: Advances in Physiology Education, 2012

Stress activates the hypothalamic-pituitary-adrenal axis which results in increased circulating g... more Stress activates the hypothalamic-pituitary-adrenal axis which results in increased circulating glucocorticoids. Corticosterone is a major glucocorticoid in rats and its excess causes a significant increase in the level of reactive oxygen species (ROS). The objective of this study was to assess the effects of different doses of corticosterone on epididymal sperm fertilizing capacity in surgically manipulated rats. Epididymides of the fertile male rats were surgically separated at the testis-caput junction. Twenty-four hours post-surgery, animals were injected (s.c.) with corticosterone at a dose of 5, 10 or 25 mg/kg/day for 7 consecutive days. On day 8, experimental male rats were cohabitated with cyclic proestrus females. Sperm-positive vaginal smear was considered as day 1 of pregnancy (p.c.). Pregnant females were laparotomized on day 8 p.c. to determine the number of implantation sites and were left until term. At parturition, the number of pups delivered was counted and compared with the number of implantation sites to determine pregnancy outcome. Results showed that only corticosterone of 25mg/kg/day for 7 consecutive days significantly decreased (p<0.05) the number of implantation sites as compared to controls. Moreover, the intrauterine embryonic loss was found to be significantly increased (p<0.01). It is concluded that corticosterone-induced attenuated fertilizing ability of the sperm and the embryonic viability that is fertilized by the damaged sperm could possibly result from an excess ROS which has yet to be verified.

Reproductive biology and endocrinology : RB&E, Jan 20, 2014

The effect of paternal age on semen quality is controversial. In this retrospective study, the ai... more The effect of paternal age on semen quality is controversial. In this retrospective study, the aim was to investigate the effects of advancing age on sperm parameters including reactive oxygen species (ROS), total antioxidant capacity (TAC) and sperm DNA damage in infertile men. We also examined whether paternal age >40 y is associated with higher risk of sperm DNA damage. A total of 472 infertile men presenting for infertility were divided into 4 age groups: group A: patients ≤ 30 y; group B: patients 31- 40 y, group C: ≤ 40 y and group D: patients >40 y. The following tests were performed - semen analysis according to WHO 2010 criteria, seminal ROS by chemiluminescence, TAC by colorimetric assay and sperm DNA damage by TUNEL assay - and the results were compared amongst the 4 age groups. There was no statistical difference in conventional semen parameters, TAC and ROS with advancing paternal age as well as between different age groups. However, a significant negative associa...

Reproductive Biomedicine Online, 2017

He has a PhD in male reproductive physiology from the University of Calcutta, India and over 24 p... more He has a PhD in male reproductive physiology from the University of Calcutta, India and over 24 peer reviewed publications in PubMed. He is a collaborating scientist with the American Center for Reproductive Medicine at Cleveland Clinic. KEY MESSAGE Withania sominifera roots improve semen quality by increasing sperm count and motility, regulating reproductive hormone levels and inhibiting lipid peroxidation. Proposed mechanisms underlying these effects are direct alleviation of oxidative stress and enhancement of hormonal balance via the gamma-aminobutyric acid-like mimetic pathway. Withania sominifera could potentially supplement routine treatment of male infertility. A B S T R A C T To manage male infertility caused by hormonal imbalance, infections and other predicaments, multifarious treatment strategies are emerging worldwide. Contemporary treatments, such as assisted reproductive techniques, are costly with low success rates of only 10–30%; however, herbal remedies are gaining more attention as an alternative or supplementary therapeutic modality for male infertility. The beneficial effects induced by oral intake of the roots of a small evergreen shrub, Withania sominifera (Ashwagandha) on semen quality of infertile men have previously been studied. Oral intake of Ashwagandha roots has been found to inhibit lipid peroxidation, improve sperm count and motility, and regulate reproductive hormone levels. The molecular mechanisms of these effects, however, are yet to be unveiled.

SpringerBriefs in Reproductive Biology, 2014

In recent years, survival rates of cancer patients have increased, resulting in a shift of focus ... more In recent years, survival rates of cancer patients have increased, resulting in a shift of focus
from quantity to quality of life. A key aspect of quality of life is fertility potential; patients suffering from
iatrogenic infertility often become depressed. Since many cancer therapies—chemotherapy, radiotherapy
and/or surgery—and even cancer itself have detrimental effects on the male reproductive system, it is
important to preserve fertility before any treatment commences. Currently, the only reliable method of
male fertility preservation is sperm banking. For patients who are unable to provide semen samples by the
conventional method of masturbation, there are other techniques such as electroejaculation, microsurgical
epididymal sperm aspiration and testicular sperm extraction that can be employed. Unfortunately, it is
presently impossible to preserve the fertility potential of pre-pubertal patients. Due to the increasing
numbers of adolescent cancer patients surviving treatment, extensive research is being conducted into several
possible methods such as testicular tissue cryopreservation, xenografting, in vitro gamete maturation and even
the creation of artificial gametes. However, in spite of its ease, safety, convenience and many accompanying
benefits, sperm banking remains underutilized in cancer patients. There are several barriers involved such
as the lack of information and the urgency to begin treatment, but various measures can be put in place to
overcome these barriers so that sperm banking can be more widely utilized.