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Biomedical Chromatography : BMC Jan 2019In the present study, we aimed to develop a reliable screening method based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for the detection...
Residual detection of naproxen, methyltestosterone and 17α-hydroxyprogesterone caproate in aquatic products by simple liquid-liquid extraction method coupled with liquid chromatography-tandem mass spectrometry.
In the present study, we aimed to develop a reliable screening method based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for the detection and quantification of naproxen, methyltestosterone and 17α-hydroxyprogesterone caproate residues. The target analytes were extracted from samples of eel, flatfish and shrimp using acetonitrile with 1% acetic acid, followed by liquid-liquid purification with n-hexane. Chromatographic separation was achieved on a reversed-phase analytical column using 0.1% formic acid containing 10 mm ammonium formate in distilled water (A) and methanol (B) as mobile phases. All the matrix-matched calibration curves were linear (R ≥ 0.99) over the concentration range of the tested analytes. Recovery at three spiking levels (0.005, 0.01 and 0.02 mg/kg) ranged from 68 to 117% with intra- and inter-day precisions <10%. Five market samples for each matrix (eel, flatfish and shrimp) were collected and tested for method application. In summary, the proposed method is feasible to screen and quantify the analytes with high selectivity in aquatic food products meant for human consumption.
Topics: 17 alpha-Hydroxyprogesterone Caproate; Animals; Chromatography, Liquid; Drug Residues; Eels; Flatfishes; Limit of Detection; Linear Models; Liquid-Liquid Extraction; Methyltestosterone; Naproxen; Penaeidae; Reproducibility of Results; Seafood; Tandem Mass Spectrometry
PubMed: 30246262
DOI: 10.1002/bmc.4396 -
Farmatsiia 1967
Topics: Colorimetry; Methods; Methyltestosterone; Pharmacopoeias as Topic; Spectrophotometry; Ultraviolet Rays
PubMed: 5613192
DOI: No ID Found -
Animal Reproduction Science Jun 2018Chitosan nanoparticles conjugated with 17α-methyltestosterone (CS + MT) were used for studying their effect on the testicular development of Clarias batrachus...
Chitosan nanoparticles conjugated with 17α-methyltestosterone (CS + MT) were used for studying their effect on the testicular development of Clarias batrachus during different reproductive phases. The size of chitosan nanoparticles was 127.2 nm and the nano-conjugated 17α methyltestosterone (17α-MT) was 196.1 nm (20 mg/100 ml of chitosan). Single injections of CS + MT at different doses such as 0.01, 0.1 and 0.5 μg/g body weight were administered to adults during the pre-spawning, spawning and post-spawning phase. Nano-conjugated steroid was effective at the lower dose; showing an increase in the Gonadosomatic Index (GSI) and 11-ketotestosterone level compared to the control group. Histological observations confirmed the dose-dependent advancement in spermatogenesis. These findings indicate the possibility of using CS + MT for enhancing gonadal maturity of C. batrachus.
Topics: Animals; Aquaculture; Catfishes; Chitosan; Male; Methyltestosterone; Sex Differentiation; Sexual Maturation; Spermatogenesis; Testis
PubMed: 29728276
DOI: 10.1016/j.anireprosci.2018.04.078 -
The Journal of Laryngology and Otology Apr 1966
Topics: Adult; Androgens; Female; Hoarseness; Humans; Methyltestosterone; Middle Aged
PubMed: 5909098
DOI: 10.1017/s0022215100065415 -
The Journal of Endocrinology Apr 1949
Topics: Androgens; Kidney; Methyltestosterone
PubMed: 18153265
DOI: 10.1677/joe.0.0060086 -
Drug Metabolism and Disposition: the... Nov 2009The misuse of the anabolic steroid methyltestosterone is currently routinely monitored in doping control laboratories by gas chromatography-mass spectrometry (GC-MS) of... (Comparative Study)
Comparative Study
The misuse of the anabolic steroid methyltestosterone is currently routinely monitored in doping control laboratories by gas chromatography-mass spectrometry (GC-MS) of two of its metabolites: 17alpha-methyl-5beta-androstane-3alpha,17beta-diol and 17alpha-methyl-5alpha-androstane-3alpha,17beta-diol. Because of the absence of any easy ionizable moiety, these metabolites are poorly detectable using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI). In this study, the metabolism of methyltestosterone has been reinvestigated by the use of a precursor ion scan method in LC-ESI-MS/MS. Two metabolites have been detected using this method. Both compounds have been confirmed in postadministration urine samples of an urokinase plasminogen activator-severe combined immunodeficiency (uPA-SCID) mouse with humanized liver and were characterized by LC-MS/MS and GC-MS using both quadrupole and time of flight analyzers. From the detailed study of the fragmentation, these metabolites were proposed to be epimethyltestosterone and a dehydrogenated compound. Epimethyltestosterone has previously been described as a minor metabolite, whereas the occurrence of the oxidized metabolite has not been reported. Comparison with the synthesized reference revealed that the structure of the dehydrogenated metabolite is 6-ene-epimethyltestosterone. A selected reaction monitoring method including three transitions for each metabolite has been developed and applied to samples from an excretion study and to samples declared positive after GC-MS analysis. 6-Ene-epimethyltestosterone was found in all samples, showing its applicability in the detection of methyltestosterone misuse.
Topics: Animals; Double-Blind Method; Gas Chromatography-Mass Spectrometry; Humans; Methyltestosterone; Mice; Mice, SCID; Spectrometry, Mass, Electrospray Ionization; Transplantation Chimera
PubMed: 19704028
DOI: 10.1124/dmd.109.028373 -
Lancet (London, England) Aug 1977Of 60 patients (42 female transsexuals and 18 impotent males) receiving long-term therapy with methyltestosterone 50 mg three times a day, 19 had abnormal liver-function...
Of 60 patients (42 female transsexuals and 18 impotent males) receiving long-term therapy with methyltestosterone 50 mg three times a day, 19 had abnormal liver-function tests and 33 out of 52 had abnormal liver scans, particularly those who had been treated for more than a year. Liver biopsy specimens showed accumulation of hepatocytes in the liver cords and within the walls of centrilobular veins, and early peliosis hepatis. One patient had a hepatic adenoma. Of the androgens, only 17alpha-alkylated steroids seem to be implicated in the development of cholestatic jaundice, peliosis hepatis, and liver tumours.
Topics: Adenoma; Adult; Cholestasis; Female; Humans; Infertility, Male; Liver; Liver Function Tests; Liver Neoplasms; Male; Methyltestosterone; Purpura; Transsexualism
PubMed: 69876
DOI: No ID Found -
Water Science and Technology : a... May 202417α-methyltestosterone (MT) hormone is a synthetic androgenic steroid hormone utilized to induce Nile tilapia transitioning for enhanced production yield. This study...
17α-methyltestosterone (MT) hormone is a synthetic androgenic steroid hormone utilized to induce Nile tilapia transitioning for enhanced production yield. This study specifically focuses on the removal of MT through the utilization of photocatalytic membrane reactor (PMR), which employs an in-house polyvinylidene fluoride (PVDF) ultrafiltration membrane modified with 1% nanomaterials (either TiO or α-FeO). The molecular weight cut-off (MWCO) of the in-house membrane falls within the ultrafiltration range. Under UV95W radiation, the PMR with PVDF/TiO and PVDF/α-FeO membranes achieved 100% MT removal at 140 and 160 min, respectively. The MT removal by the commercial NF03 membrane was only at 50%. In contrast, without light irradiation, the MT removal by all the membranes remained unchanged after 180 min, exhibiting lower performance. The incorporation of TiO and α-FeO enhanced water flux and MT removal of the membrane. Notably, the catalytic activity was limited by the distribution and concentration of the catalyst at the membrane surface. The water contact angle did not correlate with the water flux for the composited membrane. The degradation of MT aligned well with Pseudo-first-order kinetic models. Thus, the in-house ultrafiltration PMR demonstrated superior removal efficiency and lower operational costs than the commercial nanofiltration membrane, attributable to its photocatalytic activities.
Topics: Ultrafiltration; Membranes, Artificial; Water Pollutants, Chemical; Methyltestosterone; Catalysis; Water Purification; Titanium
PubMed: 38747961
DOI: 10.2166/wst.2024.144 -
Steroids Dec 1978The preparation of the title compounds from hyodeoxycholic acid is described. A modified Oppenauer oxidation using alumina in place of conventional alkoxide catalyst is...
The preparation of the title compounds from hyodeoxycholic acid is described. A modified Oppenauer oxidation using alumina in place of conventional alkoxide catalyst is outlined.
Topics: Androstanes; Deoxycholic Acid; Isomerism; Methods; Methyltestosterone; Oxidation-Reduction; Pregnanes; Testosterone
PubMed: 734694
DOI: 10.1016/0039-128x(78)90070-3 -
American Journal of Ophthalmology Jun 2005To determine whether systemic replacement with combined esterified estrogen (EE) and methyltestosterone (MT) (EE + MT) would reduce symptoms and promote clinical...
PURPOSE
To determine whether systemic replacement with combined esterified estrogen (EE) and methyltestosterone (MT) (EE + MT) would reduce symptoms and promote clinical improvement in postmenopausal women with dry eye syndrome (DES).
DESIGN
Retrospective, noncomparative, interventional case series.
METHODS
Investigators reviewed the charts of 11 postmenopausal women treated within the last 3 years with EE + MT.
RESULTS
The mean patient age was 65.2 years (standard deviation [SD] 11.4, range 48-84 years). The mean treatment duration was 12.2 months (SD 6.2 months, range 4-24 months). Ten (91%) of 11 patients reported improvement in dry eye symptoms while receiving treatment. For these 10, relief occurred after an average of 4.1 months of treatment (SD 3.2, range, 1-9 months).
CONCLUSIONS
Treatment with EE + MT may be efficacious for DES of various etiologies. A randomized placebo-controlled trial is planned to further evaluate these encouraging findings.
Topics: Aged; Aged, 80 and over; Drug Combinations; Dry Eye Syndromes; Estrogens; Estrogens, Esterified (USP); Female; Humans; Methyltestosterone; Middle Aged; Postmenopause; Retrospective Studies; Treatment Outcome
PubMed: 15953447
DOI: 10.1016/j.ajo.2004.11.042