scholarly journals Site-specific glycan analysis of human chorionic gonadotropin  -subunit from malignancies and pregnancy by liquid chromatography--electrospray mass spectrometry

Glycobiology ◽  
2006 ◽  
Vol 16 (12) ◽  
pp. 1207-1218 ◽  
Author(s):  
L. Valmu ◽  
H. Alfthan ◽  
K. Hotakainen ◽  
S. Birken ◽  
U.-H. Stenman
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Electrospray Mass Spectrometry ◽  
Site Specific ◽  
Glycan Analysis

scholarly journals Human chorionic gonadotropin stimulation gives evidence of differences in testicular steroidogenesis in Klinefelter syndrome, as assessed by liquid chromatography–tandem mass spectrometry

2016 ◽  
Vol 174 (6) ◽  
pp. 801-811 ◽  
Author(s):  
S Belli ◽  
D Santi ◽  
E Leoni ◽  
E Dall’Olio ◽  
F Fanelli ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Klinefelter Syndrome ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Testicular Steroidogenesis

Background Men with Klinefelter syndrome (KS) show hypergonadotropic hypogonadism, but the pathogenesis of hypotestosteronemia remains unclear. Testicular steroidogenesis in KS men was evaluated over three decades ago after human chorionic gonadotropin (hCG) stimulation, but inconclusive results were obtained. Intriguingly, some recent studies show increased intratesticular testosterone concentrations in men with KS. Objective To analyze serum steroid profile, as a proxy of testicular steroidogenesis, after hCG stimulation in KS compared with control men. Design A prospective, longitudinal, case–control, clinical trial. Methods Thirteen KS patients (36±9 years) not receiving testosterone (TS) replacement therapy and 12 eugonadic controls (32±8 years) were enrolled. Serum steroids were measured by liquid chromatography–tandem mass spectrometry (LC–MS/MS) at baseline and for five consecutive days after intramuscular injection of 5000IU hCG. Results Progesterone (P), 17-hydroxyprogesterone (17OHP), TS, and estradiol (E2) showed a significant increase (P<0.001) after hCG stimulation in both groups. On the contrary, androstenedione (AS) and dehydroepiandrosterone did not increase after hCG stimulation. The 17OHP/P ratio increased in both groups (P<0.001), the TS/AS ratio (17β-hydroxysteroid dehydrogenase type 3 (17βHSD3) activity) did not increase after hCG in any group, and the E2/TS ratio (aromatase activity) increased significantly in both groups (P=0.009 in KS and P<0.001 in controls). Luteinizing hormone decreased after hCG in both groups (P=0.014 in KS and P<0.001 in controls), whereas follicle-stimulating hormone decreased only in control men (P<0.001). Conclusion This study demonstrates for the first time using LC–MS/MS that Leydig cells of KS men are able to respond to hCG stimulation and that the first steps of steroidogenesis are fully functional. However, the TS production in KS men is impaired, possibly related to reduced hydroxysteroid deydrogenase activity due to an unfavorable intratesticular metabolic state.

Glycosylation patterns of human chorionic gonadotropin revealed by liquid chromatography-mass spectrometry and bioinformatics

2006 ◽  
Vol 27 (13) ◽  
pp. 2734-2746 ◽  
Author(s):  
Hansjörg Toll ◽  
Peter Berger ◽  
Andreas Hofmann ◽  
Andreas Hildebrandt ◽  
Herbert Oberacher ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Liquid Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry

Site-specific analysis of theN-glycans on murine polymeric immunoglobulin A using liquid chromatography/electrospray mass spectrometry

1995 ◽  
Vol 30 (12) ◽  
pp. 1679-1686 ◽  
Author(s):  
Eddy A. Kragten ◽  
Aldert A. Bergwerff ◽  
Jan van Oostrum ◽  
Dieter R. Müller ◽  
Wilhelm J. Richter
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Electrospray Mass Spectrometry ◽  
Immunoglobulin A ◽  
Site Specific ◽  
Specific Analysis

Suggested Cutoff Point for Testosterone by Liquid Chromatography with Tandem Mass Spectrometry (LC-MS/MS) after Stimulation with Recombinant Human Chorionic Gonadotropin

2021 ◽  
pp. 1-4
Author(s):  
Leticia R. de Oliveira ◽  
Carlos A. Longui ◽  
Guilherme Guaragna-Filho ◽  
José L. da Costa ◽  
Rafael Lanaro ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Disorders Of Sex Development ◽  
Cutoff Point ◽  
Tandem Mass ◽  
Prepubertal Children ◽  
Sex Development

The human chorionic gonadotropin (hCG) stimulation test that evaluates gonadal steroidogenesis is crucial in the assessment of patients with 46,XY disorders of sex development (DSD). This study aimed to determine a testosterone (T) cutoff level that indicates an adequate testicular function using LC-MS/MS after stimulation with recombinant human chorionic gonadotropin (rhCG) in a single dose. Nineteen prepubertal children with 46,XY DSD and normal T secretion were evaluated. T and dihydrotestosterone (DHT) levels were measured by liquid chromatography technique with tandem mass spectrometry (LC-MS/MS) before and 7 days after rhCG application at 250 µg. We suggest 0.89 ng/mL as the cutoff point for T after rhCG stimulation analyzed by LC-MS/MS.

Site-specific degree of phosphorylation in proteins measured by liquid chromatography-electrospray mass spectrometry

PROTEOMICS ◽  
2012 ◽  
Vol 12 (13) ◽  
pp. 2167-2178 ◽  
Author(s):  
Martin E. Boehm ◽  
Joerg Seidler ◽  
Bettina Hahn ◽  
Wolf D. Lehmann
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Electrospray Mass Spectrometry ◽  
Site Specific ◽  
Specific Degree
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