Displaying publications 1 - 20 of 45 in total

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  1. Tan GJ, Kwan TK
    Contraception, 1987 Sep;36(3):359-67.
    PMID: 3677679
    The effect of oxytocin on testicular function was examined in the adult male long-tailed macaques (Macaca fascicularis). The monkeys were either infused with increasing concentrations of synthetic oxytocin (16-128 m.i.u./min for 3 h) or injected daily for a week with the same hormone (20 i.u., i.v.) and the plasma testosterone levels measured. The results of the present study show that acute infusion or chronic injection of oxytocin does not significantly affect the plasma testosterone levels, suggesting that systemic control of testicular endocrine function by oxytocin may be unimportant.
    Matched MeSH terms: Testosterone/blood*
  2. Ng BH, Yuen KH
    PMID: 12906917
    A simple and sensitive high-performance liquid chromatographic (HPLC) method using ultraviolet detection was developed for the determination of testosterone in human plasma. Testosterone and the internal standard, griseofulvin, were extracted from 0.50 ml plasma sample using a mixture of dichloromethane-2,2,4-trimethylpentane (3:2, v/v). The mobile phase, consisted of 0.02 M sodium dihydrogenphosphate-acetonitrile-methanol (51:47:2, v/v) adjusted to pH 3.1 and delivered to a C(18) analytical column (150 x 4.6 mm I.D., 4 microm particles) at a flow-rate of 1 ml/min while the detection wavelength was set at 240 nm with a sensitivity range of 0.005 a.u.f.s. The method has a quantification limit of 1.6 ng/ml. Recoveries of testosterone were all greater than 92% over the linear concentration range of 1.6-400 ng/ml while that of griseofulvin was approximately 95%. The within- and between-day RSD values were all less than 8% while the accuracy values ranged from 96.0 to 106.0% over the concentration range studied. The method was applied to the analysis of early morning plasma testosterone levels of 12 healthy human male volunteers. The levels were found to range from 3.1 to 8.4 ng/ml, within the normal range reported in the literature.
    Matched MeSH terms: Testosterone/blood*
  3. Kamishima M, Hattori T, Suzuki G, Matsukami H, Komine C, Horii Y, et al.
    J Appl Toxicol, 2018 05;38(5):649-655.
    PMID: 29271492 DOI: 10.1002/jat.3569
    Exposure to endocrine-disrupting chemicals may adversely affect animals, particularly during development. Tris(1,3-dichloroisopropyl) phosphate (TDCIPP) is an organophosphate with anti-androgen function in vitro that is present in indoor dust at relatively high concentrations. In male rats, androgens are necessary for the development of reproductive organs, as well as the endocrine and central nervous systems. However, we currently do not know the exact effects of TDCIPP exposure through suckling on subsequent reproductive behavior in males. Here, we show that TDCIPP exposure (25-250 mg kg-1 via oral administration over 28 consecutive days post-birth) suppressed male sexual behavior and reduced testes size. These changes were dose-dependent and appeared first in adults rather than in juveniles. These results demonstrate that TDCIPP exposure led to normal body growth and appearance in juveniles, but disrupted the endocrine system and physiology in adults. Therefore, assays should be performed using adult animals to ensure accuracy, and to confirm the influence of chemical substances given during early mammalian life.
    Matched MeSH terms: Testosterone/blood
  4. Chin KY, Ima-Nirwana S, Mohamed IN, Aminuddin A, Ngah WZ
    Exp. Clin. Endocrinol. Diabetes, 2013 Jul;121(7):407-12.
    PMID: 23765753 DOI: 10.1055/s-0033-1345164
    Testosterone and sex hormone-binding globulin (SHBG) have been shown to be associated with metabolic syndrome (MS) in men. This study aimed at validating these relationships in a group of middle-aged and elderly men and assessing their strength of association to MS. A cross-sectional study of 332 Malaysian men aged 40 years and above was conducted. The blood of subject was collected under fasting condition for determination of testosterone, SHBG, glucose and lipid levels. Their medical history, smoking and alcohol consumption status, waist circumference (WC), body mass index (BMI) and blood pressure (BP) were recorded. All testosterone and SHBG levels were significantly reduced in MS subjects compared to non-MS subjects (p<0.05). Testosterone and SHBG were correlated significantly with most of the MS indicators without adjustments. In multiple regression analysis, the triglyceride level was the only MS indicator that was significantly, inversely and independently associated with all testosterone measurements and SHBG (p<0.05). Waist circumference was significantly and negatively associated with SHBG level (p<0.05) though not independent of BMI. Total testosterone and SHBG were significantly and inversely associated with the presence of MS. Testosterone and SHBG are potential intervention targets for the prevention of MS in men.
    Matched MeSH terms: Testosterone/blood*
  5. Chin KY, Soelaiman IN, Naina Mohamed I, Shahar S, Teng NI, Suhana Mohd Ramli E, et al.
    Aging Male, 2012 Dec;15(4):240-5.
    PMID: 23098182 DOI: 10.3109/13685538.2012.724740
    OBJECTIVE: Variations in testosterone levels are associated with several outcomes of aging. The present study aimed to examine the relationship between age-related decline of testosterone levels and changes in bone health status, handgrip strength, body fat percentage and fat-free mass.
    MATERIALS AND METHODS: A total of 335 Malaysian Chinese and Malay men aged 40 years and above were recruited for this study. Their body compositions, calcaneal speed of sound and handgrip strength were measured and their blood was collected. Linear regression analysis was done to examine the relationship among age, testosterone levels and outcomes of aging.
    RESULTS: The results indicated significant changes in all testosterone measurements, sex hormone binding globulin level, calcaneal speed of sound, handgrip strength, body fat percentage and fat-free mass with age (p < 0.05). Age-dependent decline in bioavailable and free testosterone levels were significantly associated with reduction in calcaneal speed of sound, fat-free mass and handgrip strength (p < 0.05). Age-dependent decline in the total testosterone level was significantly associated with an increase in body fat percentage among the elderly men (p < 0.05).
    CONCLUSION: Testosterone levels are associated with changes in outcome of aging such as bone health status, muscle strength and body composition, and the relationships are age-dependent.
    Matched MeSH terms: Testosterone/blood*
  6. Tong SF, Ng CJ, Lee BC, Lee VK, Khoo EM, Lee EG, et al.
    Asian J. Androl., 2012 Jul;14(4):604-11.
    PMID: 22635164 DOI: 10.1038/aja.2011.178
    This study aimed to investigate the effect of intramuscular injection of testosterone undecanoate on overall quality of life (QoL) in men with testosterone deficiency syndrome (TDS). A randomized controlled trial over a 12-month period was carried out in 2009. One hundred and twenty men aged 40 years and above with a diagnosis of TDS (serum total testosterone <12 nmol l(-1) and total Aging Male Symptom (AMS) scores ≥27) were invited to participate. Interventions comprised intramuscular injection of either placebo or 1000 mg testosterone undecanoate, given at weeks 0, 6, 18, 30 and 42. This paper presents the secondary analysis of QoL changes measured in the scores of Short-Form-12 (SF-12) scale at baseline, weeks 30 and 48 after the first injection. A total of 56/60 and 58/60 men from the active treatment and placebo group, respectively, completed the study. At week 48, before adjusting for baseline differences, the QoL of men in the treatment group improved significantly in five out of the eight domains on SF-12. The physical health composite scores improved 4.0 points from a baseline of 41.9±7.0 in the treatment group compared to 0.8 point from a baseline of 43.7±7.1 in the placebo group (F=3.652, P=0.027). The mental health composite scores improved 4.4 points from a baseline of 37.1±9.0 in the treatment group compared to 1.0 points from a baseline of 37.6±7.9 in the placebo group (F=4.514, P=0.018). After adjusting for baseline differences, significant improvement was observed in mental health composite scores, but not in physical health composite scores. Long-acting testosterone undecanoate significantly improved the mental health component of QoL in men with TDS.
    Study: Subang Jaya Aging Men's Health Study
    Funding: Bayer Schering Pharma
    Matched MeSH terms: Testosterone/blood
  7. Tambi MI, Imran MK, Henkel RR
    Andrologia, 2012 May;44 Suppl 1:226-30.
    PMID: 21671978 DOI: 10.1111/j.1439-0272.2011.01168.x
    In most countries, millions of people are relying on herbal medicines as remedy for numerous ailments. In South-East Asia, Eurycoma longifolia Jack, also known as 'Malaysian ginseng' or Tongkat ali, is used to combat stress and disease and to improve physical strength. Moreover, the compounds of the roots of this plant are reported to have aphrodisiac and testosterone enhancing effects in the rat. Considering that human studies are not available, 76 of 320 patients suffering from late-onset hypogonadism (LOH) were given 200 mg of a standardised water-soluble extract of Tongkat ali for 1 month. The Ageing Males' Symptoms (AMS) according to the standardised rating scale and the serum testosterone concentration were taken. Results show that treatment of LOH patients with this Tongkat ali extract significantly (P < 0.0001) improved the AMS score as well as the serum testosterone concentration. While before treatment only 10.5% of the patients did not show any complaint according to the AMS scale and 35.5% had normal testosterone levels, after the completed treatment 71.7% and 90.8% of the patients showed normal values, respectively. Thus, Tongkat ali extract appears to be useful as a supplement in overcoming the symptoms of LOH and for the management of hypogonadism.
    Matched MeSH terms: Testosterone/blood
  8. Yunianto I, Das S, Mat Noor M
    Clin Ter, 2010;161(3):235-9.
    PMID: 20589353
    Antifertility agents with safety and effectiveness in terms of minimum side effects have always been a subject of debate. Many studies have been conducted on plants to observe the antifertility effect, but majority of them were toxic. Pegaga or Centella asiatica L. is one of the popular herb traditionally consumed raw amongst people in Malaysia. The main objective of the present study was to investigate the effects of Centella asiatica L. extract on rat testis.
    Matched MeSH terms: Testosterone/blood*
  9. Hod R, Kouidhi W, Ali Mohd M, Husain R
    Asia Pac J Clin Nutr, 2016;25(1):89-96.
    PMID: 26965767 DOI: 10.6133/apjcn.2016.25.1.02
    Epidemiological studies indicate lower prevalences of breast and prostate cancers and cardiovascular disease in Southeast Asia where vegetarianism is popular and diets are traditionally high in phytoestrogens. This study assessed plasma isoflavones in vegetarian and non-vegetarian Malaysian men according to age. Daidzein, genistein, equol (a daidzein metabolite), formononetin, biochanin A, estrone, estradiol and testosterone were measured by validated liquid chromatography tandem mass spectrometry (LCMSMS). Plasma isoflavone and sex hormone concentrations were measured in 225 subjects according to age (18-34, 35-44 and 45-67 years old). In all age groups, vegetarians had a higher concentration of circulating isoflavones compared with non-vegetarians especially in the 45-67 year age group where all isoflavones except equol, were significantly higher in vegetarians compared with omnivores. By contrast, the 18-34 year group had a significantly higher concentration of daidzein in vegetarians and significantly higher testosterone and estrone concentrations compared with non-vegetarians. In this age group there were weak correlations between estrone, estradiol and testosterone with some of the isoflavones. This human study provides the first Malaysian data for the phytoestrogen status of vegetarian and nonvegetarian men.
    Matched MeSH terms: Testosterone/blood
  10. Chin KY, Ima-Nirwana S, Wan Ngah WZ
    Aging Male, 2015;18(3):175-9.
    PMID: 26004987 DOI: 10.3109/13685538.2015.1034686
    OBJECTIVE: Cross-sectional studies in the Caucasian population have shown a significant relationship between vitamin D and testosterone levels, but data in the Asian population are limited. This study aimed to determine the association between vitamin D and testosterone levels in Malaysian men.

    METHODS: Chinese and Malay men (n = 382) aged 20 years or above residing in the Klang Valley, Malaysia were recruited. Their fasting blood was collected for serum testosterone, sex hormone-binding globulin (SHBG) and 25-hydroxyvitamin D (25(OH)D) assays. Relationship between 25(OH)D and testosterone levels was analyzed using multiple regression analysis. Testosterone and SHBG levels among subjects with different vitamin D status were compared using univariate analysis. Confounders such as age, ethnicity and body mass index (BMI) were adjusted.

    RESULTS: 25(OH)D was significantly and positively associated with total testosterone and SHBG levels before and after adjustment for age and ethnicity (p  0.05).

    CONCLUSION: 25(OH)D is significantly associated with total testosterone and SHBG in Malaysian men but this association is BMI-dependent.

    Matched MeSH terms: Testosterone/blood*
  11. Chow WP, Loganath A, Peh KL, Chew PC, Gunasegaram R, Ratnam SS
    Med. J. Malaysia, 1993 Mar;48(1):56-63.
    PMID: 8341173
    This study investigated whether changes in circulating levels of immunoreactive oestradiol-17 beta (E2), progesterone (P) and testosterone (T) occur in women at follicular (n = 18, age 25 to 39 years) and luteal (n = 17, 25 to 39 years) phases of the normal menstrual cycles, experiencing laparoscopy after intravenous sedation with general anaesthesia. The pre- and intra-operative follicular phase plasma steroid hormone concentrations were 153.5 +/- 84.3 vs 297.4 +/- 220.8 pg/ml for E2, 2.0 +/- 3.2 vs 3.3 +/- 3.8 ng/ml for P and 746.6 +/- 415.9 vs 1325.8 +/- 535.1 pg/ml for T, respectively. The corresponding luteal phase steroid levels were 259.7 +/- 120.2 vs 382.7 +/- 188.7 pg/ml, 7.0 +/- 4.8 vs 9.9 +/- 6.1 ng/ml and 819.4 +/- 355.7 vs 1703.5 +/- 1058.1 pg/ml. Using the Wilcoxon rank sum test, intra-operative hormone levels with the exception of P in the luteal phase were found to be significantly elevated (p < 0.05). The results suggest that laparoscopy under general anaesthesia evokes increased secretion of ovarian hormones, possibly via the activation of hypothalamo-pituitary-ovarian axis.
    Matched MeSH terms: Testosterone/blood*
  12. Tan TT, Lui SK, Satgunasingam N, Khalid BA
    Med. J. Malaysia, 1989 Dec;44(4):302-6.
    PMID: 2520038
    62 cases of polycystic ovary syndrome (PCO) were reviewed with regards to their clinical and endocrine features. The subgroup of patients with acanthosis nigricans (AN) was further studied in detail. The prevalence of the syndrome was significantly higher in the Indian (35.5% of cases). Obesity, AN, hirsutism, non-insulin dependent diabetes mellitus (NIDDM) and raised level of serum testosterone were present in 77.1%, 74%, 79%, 21% and 48% of the cases respectively. Patients with AN was associated with higher body mass index, serum testosterone level, and prevalence of hirsutism and NIDDM than patients without AN. These observations are in keeping with the hypothesis that hyperinsulinemia may be of importance in the pathogenesis of a sub-group of PCO associated with insulin resistant states.
    Matched MeSH terms: Testosterone/blood
  13. Wickramatilake CM, Mohideen MR, Pathirana C
    Indian Heart J, 2017 02 12;69(2):291.
    PMID: 28460787 DOI: 10.1016/j.ihj.2017.02.002
    Matched MeSH terms: Testosterone/blood*
  14. Maekawa F, Nagino K, Yang J, Htike NTT, Tsukahara S, Ubuka T, et al.
    Gen. Comp. Endocrinol., 2018 01 15;256:63-70.
    PMID: 28765073 DOI: 10.1016/j.ygcen.2017.07.025
    The National Institute for Environmental Studies (NIES) of Japan established a strain of Japanese quail (Coturnix japonica) known as NIES-L by rotation breeding in a closed colony for over 35years; accordingly, the strain has highly inbred-like characteristics. Another strain called NIES-Brn has been maintained by randomized breeding in a closed colony to produce outbred-like characteristics. The current study aimed to characterize intermale aggressive behaviors in both strains and to identify possible factors regulating higher aggression in the hypothalamus, such as sex hormone and neuropeptide expression. Both strains displayed a common set of intermale aggressive behaviors that included pecking, grabbing, mounting, and cloacal contact behavior, although NIES-Brn quail showed significantly more grabbing, mounting, and cloacal contact behavior than did NIES-L quail. We examined sex hormone levels in the blood and diencephalon in both strains. Testosterone concentrations were significantly higher in the blood and diencephalon of NIES-Brn quail compared to NIES-L quail. We next examined gene expression in the hypothalamus of both strains using an Agilent gene expression microarray and real-time RT-PCR and found that gene expression of mesotocin (an oxytocin homologue) was significantly higher in the hypothalamus of NIES-Brn quail compared to NIES-L quail. Immunohistochemistry of the hypothalamus revealed that numbers of large cells (cell area>500μm2) expressing mesotocin were significantly higher in the NIES-Brn strain compared to the NIES-L strain. Taken together, our findings suggest that higher testosterone and mesotocin levels in the hypothalamus may be responsible for higher aggression in the NIES-Brn quail strain.
    Matched MeSH terms: Testosterone/blood
  15. Singh D, Murugaiyah V, Hamid SBS, Kasinather V, Chan MSA, Ho ETW, et al.
    J Ethnopharmacol, 2018 Jul 15;221:30-36.
    PMID: 29626673 DOI: 10.1016/j.jep.2018.04.005
    ETHNOPHARMACOLOGICAL RELEVANCE: Mitragyna speciosa (Korth.) also known as kratom, is a native medicinal plant of Southeast Asia with opioid-like effects. Kratom tea/juice have been traditionally used as a folk remedy and for controlling opiate withdrawal in Malaysia. Long-term opioid use is associated with depletion in testosterone levels.

    AIM OF THE STUDY: Since kratom is reported to deform sperm morphology and reduce sperm motility, we aimed to clinically investigate the testosterone levels following long-term kratom tea/juice use in regular kratom users.

    METHODS: A total of 19 regular kratom users were recruited for this cross-sectional study. A full-blood test was conducted including determination of testosterone level, follicle stimulating hormone (FSH) and luteinizing hormone (LH) profile, as well as hematological and biochemical parameters of participants.

    RESULTS: We found long-term kratom tea/juice consumption with a daily mitragynine dose of 76.23-94.15 mg did not impair testosterone levels, or gonadotrophins, hematological and biochemical parameters in regular kratom users.

    CONCLUSION: Regular kratom tea/juice consumption over prolonged periods (>2 years) was not associated with testosterone impairing effects in humans.

    Matched MeSH terms: Testosterone/blood*
  16. Chin KY, Soelaiman IN, Mohamed IN, Ahmad F, Ramli ES, Aminuddin A, et al.
    Clinics (Sao Paulo), 2013;68(2):159-66.
    PMID: 23525310
    OBJECTIVES: Variations in the prevalence of sex-hormone-related diseases have been observed between Asian ethnic groups living in the same country; however, available data concerning their sex hormone levels are limited. The present study aimed to determine the influence of ethnicity and age on the sex hormone levels of Malay and Chinese men in Malaysia.

    METHODS: A total of 547 males of Malay and Chinese ethnicity residing in the Klang Valley Malaysia underwent a detailed screening, and their blood was collected for sex hormones analyses.

    RESULTS: Testosterone levels were normally distributed in the men (total, free and non-sex hormone-binding globulin (SHBG) bound fractions), and significant ethnic differences were observed (p<0.05); however, the effect size was small. In general, testosterone levels in males began to decline significantly after age 50. Significant ethnic differences in total, free and non-SHBG bound fraction estradiol levels were observed in the 20-29 and 50-59 age groups (p<0.05). The estradiol levels of Malay men decreased as they aged, but they increased for Chinese men starting at age 40.

    CONCLUSIONS: Small but significant differences in testosterone levels existed between Malay and Chinese males. Significant age and race differences existed in estradiol levels. These differences might contribute to the ethnic group differences in diseases related to sex hormones, which other studies have found in Malaysia.

    Matched MeSH terms: Testosterone/blood*
  17. Leong CT, D'Souza UJ, Iqbal M, Mustapha ZA
    Redox Rep., 2013;18(4):155-64.
    PMID: 23849340 DOI: 10.1179/1351000213Y.0000000054
    The rapid emergence of various pesticides in the market is inevitable due to the demands from agriculture industries and domestic needs to control nuisance pests and to sustain green resources worldwide. However, long-term exposure to pesticide has led to adverse effects on male fertility. Organophosphate diazinon (O,O-diethyl-O-[2-isopropyl-6-methyl-4-pyrimidinyl] phosphorothiote) is an often abusively used pesticide, as it is effective and economical. This study is to determine the adverse effects of low-dose diazinon exposure on the male reproductive system. In this study, 72 Sprague-Dawley rats were segregated into 1, 2, and 8 weeks of exposure groups and further sub-grouped (n = 6) to receive 0, 10, 15, and 30 mg/kg body weight diazinon treatment. Rats were gavaged orally with diazinon and sacrificed under anaesthesia the day after the last exposure. Our results showed that consistent diazinon exposure decreased glutathione and catalase, and increased lipid peroxidation which together lead to diazinon-mediated oxidative stress. Additionally, diazinon increased serum lactate dehydrogenase and decreased serum testosterone, which may have caused sperm and histopathological anomalies. In conclusion, exposure to diazinon caused changes in lipid peroxidation and sperm, and these two effects might be causally linked.
    Matched MeSH terms: Testosterone/blood
  18. Adebiyi FA, Siraj SS, Harmin SA, Christianus A
    Fish Physiol. Biochem., 2013 Jun;39(3):547-57.
    PMID: 23010937 DOI: 10.1007/s10695-012-9718-x
    Plasma sex steroid hormonal profile and gonad histology were correlated to study the annual reproductive cycle of Hemibagrus nemurus. Hormones were measured by Enzyme Linked Immunosorbent Assay. Gonad tissues were observed by using light microscopy. The highest testosterone (T) value for male was observed in November and that of female was in October. 11-ketotestosterone (11-KT) and 17β-estradiol (E2) levels were highest in June and November, respectively. Hormonal profiles of T, 11-KT and E2 showed several peaks which indicated a non-seasonal pattern. There were significant differences (p 
    Matched MeSH terms: Testosterone/blood
  19. Ellis L, Das S
    Int J Offender Ther Comp Criminol, 2013 Aug;57(8):966-84.
    PMID: 22514238 DOI: 10.1177/0306624X12440564
    There is little doubt that family factors can influence involvement in delinquency, although the full nature and extent of their influences remain unclear. In recent decades, testosterone has been increasingly implicated as a contributor to adolescent offending. The present study sought to determine whether two important types of familial factors--parental socioeconomic status and amicable parent-child relationships--are interacting with testosterone (and possibly other androgens) to affect delinquency. A large sample of North American college students self-reported their involvement in eight categories of delinquency along with self-ratings of various androgen-promoted traits (e.g., muscularity and low-deep voice), parental social status, and the quality of the relationships they had with parents. In both sexes, parent-child relationships and androgens were significantly associated with delinquency but parental social status was not. Factor analysis revealed that the authors' measures of all four categories of variables exhibited strong loadings onto their respective factors. Androgens and amicable parent-child relationships were associated with delinquency but parental social status was not. About one third of the influence of parent-child relationships on delinquency appeared to be attributable to androgens. Findings are discussed from the perspective of the evolutionary neuroandrogenic theory of delinquent and criminal behavior.
    Matched MeSH terms: Testosterone/blood*
  20. Ikonomopoulou MP, Olszowy H, Hodge M, Bradley AJ
    PMID: 19247670 DOI: 10.1007/s00360-009-0347-3
    In this study on green turtles, Chelonia mydas, from Peninsular Malaysia, the effect of selected environmental toxicants was examined in vitro. Emphasis was placed on purported hormone-mimicking chemicals such as dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene, dieldrin, lead, zinc and copper. Five concentrations were used: high (1 mg/L), medium (10(-1) mg/L), low (10(-2) mg/L), very low (10(-6) mg/L) and control (diluted carrier solvent but no toxicants). The results suggest that environmental pesticides and heavy metals may significantly alter the binding of steroids [i.e. testosterone (T) and oestradiol] to the plasma proteins in vitro. Competition studies showed that only Cu competed for binding sites with testosterone in the plasma collected from nesting C. mydas. Dieldrin and all heavy metals competed with oestradiol for binding sites. Furthermore, testosterone binding affinity was affected at various DDT concentrations and was hypothesised that DDT in vivo may act to inhibit steroid-protein interactions in nesting C. mydas. Although the precise molecular mechanism is yet to be described, DDT could have an effect upon the protein conformation thus affecting T binding (e.g. the T binding site on the steroid hormone binding protein molecule).
    Matched MeSH terms: Testosterone/blood
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