BACKGROUND Patients with trophoblastic diseases produce ordinary and irregular forms of human chorionic gonadotropin (hCG; e.g., nicked hCG, hCG missing the beta-subunit C-terminal segment, hyperglycosylated hCG, and free beta subunit) that are recognized to differing extents by automated immunometric hCG (or hCG beta) assays. This has led to low or false-negative results and misdiagnosis of pe...

The unsatisfactory standardization of many immunoassays is fairly well recognized, but the problem is hard to tackle (1 ). Recently, studies on the performance of immunoassays for testosterone in female serum (2 ) and for urinary cortisol (1 ) have revealed that the quality of some widely used assays is totally unsatisfactory. The quality of assays for human chorionic gonadotropin (hCG) has als...

Human chorionic gonadotropin (HCG) was desialized by treatment with neuraminidase to yield asialo-HCG, and comparative physicochemical studies were carried out on HCG and asialo-HCG. The E:trn value at 276 nm was 5.47 for HCG and 5.72 for asialo-HCG. Intrinsic viscosities of HCG and asialo-HCG at near isoionic point were estimated to be 3.4 and 3.2 ml per g, respectively. HCG had an isoionic po...

We present the interferometric measurements of 2.6 mm CO (J = 1 ! 0) emission (F W HM 5 00) and the analysis of IRAS HIRES images of two Hickson Compact Groups HCG 31 and HCG 92 (\Stephan's Quintet"). The far infrared (FIR) emission is concentrated to a single region in HCG 31 while it is clearly extended and peaks near the group center in HCG 92. CO emission is weak in HCG 31, and the brightes...

We evaluated the performance of four visually read pregnancy tests (TestPack Plus hCG Combo, ICON II hCG, SureCell hCG-Serum/Urine and PregnaGen 1-Step) designed to detect increased concentrations of choriogonadotropin (hCG) in either serum or urine samples. The biochemical sensitivities and specificity in both serum and urine samples were similar for each kit. All kits correctly identified pre...

Human chorionic gonadotropin (hCG) exhibits molecular heterogeneity in both its protein and carbohydrate moieties. This communication describes changes in hCG isoforms detected directly in clinical samples. These isoforms, quantified in blood or urine specimens, show a progression of change throughout normal pregnancy. Early pregnancy produces a type of hCG that resembles, in terms of immunorea...

patients were referred to an oncologist or gynecologic oncologist with a suspected diagnosis of trophoblast disease or postgestational choriocarcinoma. Four of the six cases received multiple courses of methotrexate chemotherapy, and one of the six received in addition EMACO chemotherapy, with no major quantitative reduction in false-positive hCG results. After chemotherapy, two patients underw...

BACKGROUND The 1st WHO International Reference Reagents (IRRs) for 6 human chorionic gonadotropin (hCG)-related molecular variants, highly purified and calibrated in substance concentrations by the IFCC Working Group for hCG, permit experimental elucidation of what commercially available hCG methods measure in molar terms and enable assessment of their fitness for clinical purposes. METHODS P...

BACKGROUND During pregnancy, when human chorionic gonadotropin (hCG) concentrations are highest, there is a transient suppression of serum thyrotropin (TSH). In normal pregnancy, TSH concentrations generally remain within nonpregnant reference intervals; however, in some patients TSH is suppressed. Here we sought to extend previous studies to examine the relationship between very high serum con...